The present invention relates to a conductive sheet and a touch panel.
{Background Art}
10 In recent years, touch panels are frequently used as input devices for portable
terminals and computers. Such a touch panel is placed on a surface of a display, and
performs an input operation by detecting a position touched with a finger or the like.
For example, a resistance film type and a capacitive type are known as a position
detecting method for a touch panel.
15 For example, in a capacitive touch panel, indium tin oxide (ITO) is used as a
material of a transparent electrode pattern, from the perspective of visibility. ITO,
however, has a high wiring resistance and does not have a sufficient transparency, and
hence it is discussed that a transparent electrode pattern formed using metal thin wires is
used for a touch panel.
20 Studies on transparent conductive films formed using metal thin wires are
continued as disclosed in, for example, PTL 1 and PTL 2. If an electrode is formed by
arranging a large number of grids made of metallic thin wires (metal thin wires), the
surface resistance is considered to be reduced. For example, PTL 3 to PTL 8 are known
as touch panels in which metal thin wires are used to form electrodes.
25 PTL 9 discloses a touch panel including: a plurality of first detection electrodes
that are made of net-like conductive wires and are placed in parallel in one direction; and
a plurality of second detection electrodes that are made of net-like conductive wires and
are placed in parallel in a direction orthogonal to that of the first detection electrodes.
30 {Citation List}
{Patent Literature}
{PTL 1} U.S. Patent Application Publication No. 2004/0229028
2
{PTL 2} Pamphlet of International Publication No. WO 2006/001461
{PTL 3} Japanese Patent Application Laid-Open No. 5-224818
{PTL 4} Pamphlet of International Publication No. WO 1995/27334
{PTL 5} U.S. Patent Application Publication No. 2004/0239650
5 {PTL 6} U.S. Patent No. 7202859
{PTL 7} Pamphlet of International Publication No. WO 1997/18508
{PTL 8} Japanese Patent Application Laid-Open No. 2003-099185
{PTL 9} Japanese Patent Application Laid-Open No. 2010-277392
10 {Summary of Invention}
{Technical Problem}
In the touch panel of PTL 9, if the touch panel is touched with a finger, a change
in electrostatic capacitance that occurs in the electrodes is determined, whereby a
position touched with the finger is detected. However, in a touch panel of PTL 1, in the
15 case where an upper electrode is made of a uniform conductive region and does not have
a nonconductive region, even if a finger or the like comes into contact with the touch
panel, lines of discharged electric force are closed between the electrodes, and the
detection performance of the contact of finger may become lower in some cases.
The present inventors have examined various configurations of net-like
20 electrodes. The present inventors find out that, in the case where break parts are formed
in a net-like electrode, the break parts stand out depending on the positions of the break
parts. For example, in the case where the break parts are respectively formed in
intersection parts of a plurality of conductive wires that form the net-like electrode, an
opening portion of each break part is observable as it is opened. If such opening
25 portions (break parts) are arranged on a straight line, the break parts are recognized as a
pattern, and hence the visibility may be unfavorably impaired.
The present invention, which has been made in view of such a problem, has an
object to provide a conductive sheet and a touch panel that include electrode patterns
made of metal thin wires and have a high detection accuracy of a contact position (touch
30 position) on the touch panel.
The present invention has another object to provide a conductive sheet and a
capacitive touch panel that do not impair the visibility.
3
{Solution to Problem}
A conductive sheet according to one aspect of the present invention includes: a
substrate having a first main surface and a second main surface; and a first electrode
pattern placed on the first mai 5 n surface of the substrate. The first electrode pattern is
made of metal thin wires, and alternately includes: a plurality of first conductive patterns
that extend in a first direction; and a plurality of first nonconductive patterns that are
electrically separated from the plurality of first conductive patterns. Each of the first
conductive patterns includes, at least, inside thereof, a sub-nonconduction pattern that is
10 electrically separated from the first conductive pattern. An area A of each first
conductive patterns and an area B of each sub-nonconduction pattern satisfy a relation of
5% < B / (A + B) < 97%.
Preferably, the area A of each first conductive pattern and the area B of each
sub-nonconduction pattern satisfy a relation of 10% ≤ B / (A + B) ≤ 80%.
15 Preferably, the area A of each first conductive pattern and the area B of each
sub-nonconduction pattern satisfy a relation of 10% ≤ B / (A + B) ≤ 60%.
Preferably, in the conductive sheet, each sub-nonconduction pattern has a slitlike
shape extending in the first direction, each first conductive pattern includes a
plurality of first conductive pattern lines divided by each sub-nonconduction pattern, and
20 an area A1 of each first conductive pattern and an area B1 of each sub-nonconduction
pattern satisfy a relation of 40% ≤ B1 / (A1 + B1) ≤ 60%.
Preferably, a total width Wa of widths of the first conductive pattern lines and a
total width Wb of: a total width of widths of the sub-nonconduction patterns; and a width
of the first nonconductive pattern satisfy relations of the following expressions (1) and
25 (2).
(1) 1.0 mm ≤ Wa ≤ 5.0 mm
(2) 1.5 mm ≤ Wb ≤ 5.0 mm
Preferably, in the conductive sheet, the first conductive pattern has X-shaped
structures with cyclical intersections, and an area A2 of the first conductive pattern and
30 an area B2 of the sub-nonconduction pattern satisfy a relation of 20% ≤ B2 / (A2 + B2) ≤
50%, and more preferably satisfy a relation of 30% ≤ B2 / (A2 + B2) ≤ 50%.
4
Preferably, the conductive sheet further includes a second electrode pattern
placed on the second main surface of the substrate. The second electrode pattern is
made of metal thin wires, and includes a plurality of second conductive patterns that
extend in a second direction orthogonal to the first direction.
5 Preferably, in the conductive sheet, the plurality of first conductive patterns are
formed by grids having uniform shapes, and each of the grids has one side having a
length that is equal to or more than 250 μm and equal to or less than 900 μm.
Preferably, each of the metal thin wires that form the first electrode pattern
and/or the metal thin wires that form the second electrode pattern has a wire width equal
10 to or less than 30 μm.
Preferably, in the conductive sheet, a width of the first conductive pattern line
and a width of the sub-nonconduction pattern are substantially equal to each other.
Preferably, in the conductive sheet, a width of the first conductive pattern line is
smaller than a width of the sub-nonconduction pattern.
15 Preferably, in the conductive sheet, a width of the first conductive pattern line is
larger than a width of the sub-nonconduction pattern.
Preferably, in the conductive sheet, the first electrode pattern includes a joining
part that electrically connects the plurality of first conductive pattern lines to each other.
Preferably, in the conductive sheet, a number of the first conductive pattern lines
20 is equal to or less than ten.
Preferably, in the conductive sheet, the sub-nonconduction pattern is surrounded
by a plurality of sides, and the sides are formed by linearly arranging a plurality of grids
that form the first conductive pattern, with sides of the grids being connected to each
other.
25 Preferably, in the conductive sheet, each of the sub-nonconduction pattern is
surrounded by a plurality of sides, and the sides are formed by linearly arranging, in
multiple stages, a plurality of grids that form the first conductive pattern, with sides of
the grids being connected to each other.
Preferably, in the conductive sheet, the sub-nonconduction pattern is surrounded
30 by a plurality of sides, some of the sides are formed by linearly arranging a plurality of
grids that form the first conductive pattern, with sides of the grids being connected to
5
each other, and the other sides are formed by linearly arranging the plurality of grids with
apex angles of the grids being connected to each other.
Preferably, in the conductive sheet, the plurality of sub-nonconduction patterns
defined by the sides formed by the plurality of grids are arranged along the first direction
5 with apex angles of the grids being connected to each other.
Preferably, in the conductive sheet, adjacent ones of the sub-nonconduction
patterns along the first direction have shapes different from each other.
Preferably, in the conductive sheet, each of the plurality of grids that form the
sides for defining the sub-nonconduction patterns further includes a protruding wire
10 made of a metal thin wire.
Preferably, in the conductive sheet, the first conductive pattern includes the subnonconduction
patterns at predetermined intervals, to thereby have X-shaped structures
in which the grids are not present at cyclical intersection parts.
Preferably, in the conductive sheet, adjacent ones of the sub-nonconduction
15 patterns along the first direction have the same shape each other in the first conductive
pattern, and the sub-nonconduction patterns have shapes different between adjacent ones
of the first conductive patterns.
A touch panel, preferably a capacitive touch panel, and more preferably a
projected capacitive touch panel according to another aspect of the present invention
20 includes the conductive sheet of the present invention.
A conductive sheet according to another aspect of the present invention
includes: a substrate having a first main surface and a second main surface; and a first
electrode pattern placed on the first main surface. The first electrode pattern is formed
by a plurality of grids made of a plurality of metal thin wires that intersect with each
25 other, and alternately includes: a plurality of first conductive patterns that extend in a
first direction; and a plurality of first nonconductive patterns that electrically separate the
plurality of first conductive patterns from each other. Each of the first nonconductive
patterns includes first break parts in portions other than intersection parts of the metal
thin wires. The conductive sheet includes a second electrode pattern placed on the
30 second main surface. The second electrode pattern is formed by a plurality of grids
made of a plurality of metal thin wires that intersect with each other, and alternately
includes: a plurality of second conductive patterns that extend in a second direction
6
orthogonal to the first direction; and a plurality of second nonconductive patterns that
electrically separate the plurality of second conductive patterns from each other. Each
of the second nonconductive patterns includes second break parts in portions other than
intersection parts of the metal thin wires. The first electrode pattern and the second
5 electrode pattern are placed on the substrate such that the plurality of first conductive
patterns and the plurality of second conductive patterns are orthogonal to each other in
top view and that the grids of the first electrode pattern and the grids of the second
electrode pattern form small grids in top view.
Another conductive sheet according to the present invention includes: a first
10 substrate having a first main surface and a second main surface; and a first electrode
pattern placed on the first main surface of the first substrate. The first electrode pattern
is formed by a plurality of grids made of a plurality of metal thin wires that intersect with
each other, and alternately includes: a plurality of first conductive patterns that extend in
a first direction; and a plurality of first nonconductive patterns that electrically separate
15 the plurality of first conductive patterns from each other. Each of the first
nonconductive patterns includes first break parts in portions other than intersection parts
of the metal thin wires. The conductive sheet includes: a second substrate having a first
main surface and a second main surface; and a second electrode pattern placed on the
first main surface of the second substrate. The second electrode pattern is formed by a
20 plurality of grids made of a plurality of metal thin wires that intersect with each other,
and alternately includes: a plurality of second conductive patterns that extend in a second
direction orthogonal to the first direction; and a plurality of second nonconductive
patterns that electrically separate the plurality of second conductive patterns from each
other. Each of the second nonconductive patterns includes second break parts in
25 portions other than intersection parts of the metal thin wires. The first substrate and the
second substrate are placed such that the plurality of first conductive patterns and the
plurality of second conductive patterns are orthogonal to each other in top view and that
the grids of the first electrode pattern and the grids of the second electrode pattern form
small grids in top view.
30 Preferably, in the conductive sheet according to the another aspect of the present
invention, the first break parts are respectively located near centers between the
intersection parts and the intersection parts of the metal thin wires of the first
7
nonconductive patterns, and the second break parts are respectively located near centers
between the intersection parts and the intersection parts of the metal thin wires of the
second nonconductive patterns.
Preferably, in the conductive sheet according to the another aspect of the present
invention, each of the 5 first break parts and the second break parts has a width that
exceeds a wire width of each of the metal thin wires and is equal to or less than 50 μm.
Preferably, in the conductive sheet according to the another aspect of the present
invention, the metal thin wires of the second conductive patterns are located in the first
break parts of the first nonconductive patterns in top view, and the metal thin wires of the
10 first conductive patterns are located in the second break parts of the second
nonconductive patterns in top view.
Preferably, in the conductive sheet according to the another aspect of the present
invention, assuming that a width of each of the metal thin wires of the first conductive
patterns and the metal thin wires of the second conductive patterns is a and that a width
15 of each of the first break parts of the first nonconductive patterns and the second break
parts of the second nonconductive patterns is b, a relational expression of b - a ≤ 30 μm
is satisfied.
Preferably, in the conductive sheet according to the another aspect of the present
invention, assuming that a width of each of the metal thin wires of the first conductive
20 patterns and the metal thin wires of the second conductive patterns is a and that a width
of each of the first break parts of the first nonconductive patterns and the second break
parts of the second nonconductive patterns is b, a relational expression of (b - a) / a ≤ is
satisfied.
Preferably, in the conductive sheet according to the another aspect of the present
25 invention, a positional misalignment between: a central position of each of the metal thin
wires of the first conductive patterns; and a central position of each of the second break
parts of the second nonconductive patterns has a standard deviation equal to or less than
10 μm, and a positional misalignment between: a central position of each of the metal
thin wires of the second conductive patterns; and a central position of each of the first
30 break parts of the first nonconductive patterns has a standard deviation equal to or less
than 10 μm.
8
In the conductive sheet according to the another aspect of the present invention,
the grids of the first electrode pattern and the grids of the second electrode pattern have a
grid pitch of 250 μm to 900 μm, and preferably have a grid pitch of 300 μm to 700 μm,
and the small grids have a grid pitch of 125 μm to 450 μm, and preferably have a grid
5 pitch of 150 μm to 350 μm.
Preferably, in the conductive sheet according to the another aspect of the present
invention, each of the metal thin wires that form the first electrode pattern and the metal
thin wires that form the second electrode pattern has a wire width equal to or less than 30
μm.
10 Preferably, in the conductive sheet according to the another aspect of the present
invention, each of the grids of the first electrode pattern and the grids of the second
electrode pattern has a rhomboid shape.
A capacitive touch panel according to the present invention includes any one of
the above-mentioned conductive sheets.
15 The conductive sheets according to the above-mentioned aspects and the
capacitive touch panel can suppress a decrease in visibility.
{Advantageous Effects of Invention}
According to the present invention, it is possible to provide a conductive sheet
20 and a touch panel that include electrode patterns made of metal thin wires and have a
high detection accuracy.
{Brief Description of Drawings}
{Figure 1} Figure 1 is a schematic plan view of a conductive sheet for a touch panel.
25 {Figure 2} Figure 2 is a schematic cross-sectional view of the conductive sheet.
{Figure 3} Figure 3 is an explanatory diagram for describing a behavior of the touch
panel including the conductive sheet of the present embodiment.
{Figure 4} Figure 4 is an explanatory diagram for describing a behavior of a touch panel
including a conventional conductive sheet.
30 {Figure 5} Figure 5 is a plan view illustrating an example of a first electrode pattern of a
first embodiment.
9
{Figure 6} Figure 6 is a plan view illustrating an example of another first electrode
pattern of the first embodiment.
{Figure 7} Figure 7 is a plan view illustrating an example of another first electrode
pattern of the first embodiment.
5 {Figure 8} Figure 8 is a plan view illustrating an example of another first electrode
pattern of the first embodiment.
{Figure 9} Figure 9 is a plan view illustrating an example of another first electrode
pattern of the first embodiment.
{Figure 10} Figure 10 is a plan view illustrating an example of another first electrode
10 pattern of the first embodiment.
{Figure 11} Figure 11is a plan view illustrating an example of another first electrode
pattern of the first embodiment.
{Figure 12} Figure 12 is a plan view illustrating an example of a first electrode pattern of
a second embodiment.
15 {Figure 13} Figure 13 is a plan view illustrating an example of another first electrode
pattern of the second embodiment.
{Figure 14} Figure 14 is a plan view illustrating an example of another first electrode
pattern of the second embodiment.
{Figure 15} Figure 15 is a plan view illustrating an example of another first electrode
20 pattern of the second embodiment.
{Figure 16} Figure 16 is a plan view illustrating an example of another first electrode
pattern of the second embodiment.
{Figure 17} Figure 17 is a plan view illustrating an example of another first electrode
pattern of the second embodiment.
25 {Figure 18} Figure 18 is a plan view illustrating an example of another first electrode
pattern of the second embodiment.
{Figure 19} Figure 19 is a plan view illustrating an example of another first electrode
pattern of the second embodiment.
{Figure 20} Figure 20 is a plan view illustrating an example of another first electrode
30 pattern of the second embodiment.
{Figure 21} Figure 21 is a plan view illustrating an example of another first electrode
pattern of the second embodiment.
10
{Figure 22} Figure 22 is a plan view illustrating an example of another first electrode
pattern of the second embodiment.
{Figure 23} Figure 23 is a plan view illustrating an example of a second electrode
pattern of the present embodiment.
5 {Figure 24} Figure 24 is a plan view illustrating an example of a conductive sheet for a
touch panel in which the first electrode pattern and the second electrode pattern are
combined with each other.
{Figure 25} Figure 25 is a plan view illustrating an example of another conductive sheet
for a touch panel in which the first electrode pattern and the second electrode pattern are
10 combined with each other.
{Figure 26} Figure 26 is a plan view illustrating an example of the first electrode pattern
of the first embodiment, including dummy patterns.
{Figure 27} Figure 27 is a partial enlarged view of the dummy pattern.
{Figure 28} Figure 28 is a plan view illustrating an example of the first electrode pattern
15 of the second embodiment, including dummy patterns.
{Figure 29} Figure 29 is a plan view illustrating an example of the second electrode
pattern including a dummy pattern.
{Figure 30} Figure 30 is a partial enlarged view of the dummy pattern.
{Figure 31} Figure 31 is a plan view illustrating an example of another conductive sheet
20 for a touch panel in which the first electrode pattern and the second electrode pattern are
combined with each other.
{Figure 32} Figure 32 is a plan view illustrating an example of still another conductive
sheet for a touch panel in which the first electrode pattern and the second electrode
pattern are combined with each other.
25 {Figure 33} Figure 33 is a schematic cross-sectional view of another conductive sheet.
{Figure 34} Figure 34 is an exploded perspective view illustrating, with partial omission,
a conductive sheet for a touch panel.
{Figure 35A} Figure 35A is a cross-sectional view illustrating, with partial omission, an
example of the conductive sheet for the touch panel.
30 {Figure 35B} Figure 35B is a cross-sectional view illustrating, with partial omission,
another example of the conductive sheet for the touch panel.
11
{Figure 36} Figure 36 is a plan view illustrating an example of a first electrode pattern
formed on a first conductive sheet.
{Figure 37} Figure 37 is a plan view illustrating an example of a second electrode
pattern formed on a second conductive sheet.
5 {Figure 38} Figure 38 is a plan view illustrating, with partial omission, an example in
which the first conductive sheet and the second conductive sheet are combined with each
other to form a conductive sheet for a touch panel.
{Figure 39} Figure 39 is a schematic view illustrating a positional relation between a
metal thin wire and a break part.
10 {Figure 40} Figure 40 is a schematic view illustrating a relation between a central
position of the metal thin wire and a central position of the break part.
{Description of Embodiments}
Hereinafter, preferred embodiments of the present invention are described with
15 reference to the attached drawings. The present invention is described by way of the
following preferred embodiments, but can be changed according to many methods,
without departing from the scope of the present invention. Other embodiments than the
present embodiments can be adopted for the present invention. Accordingly, all
changes within the scope of the present invention are included in the scope of the patent
20 claims. Note that, herein, "to" indicating a numerical value range is used to mean that
the numerical value range includes numerical values given before and after "to" as its
lower limit value and its upper limit value.
Figure 1 is a schematic plan view of a conductive sheet 1 for a touch panel.
The conductive sheet 1 includes a first electrode pattern 10 made of metal thin wires and
25 a second electrode pattern 40 made of metal thin wires. The first electrode pattern 10
includes a plurality of first conductive patterns 12 that extend in a first direction (X
direction) and are arranged in parallel to each other. The second electrode pattern 40
includes a plurality of second conductive patterns 42 that extend in a second direction (Y
direction) orthogonal to the first direction (X direction) and are arranged in parallel to
30 each other.
Each first conductive pattern 12 has one end electrically connected to a first
electrode terminal 14. Further, each first electrode terminal 14 is electrically connected
12
to a first wire 16 having conductive properties. Each second conductive pattern 42 has
one end electrically connected to a second electrode terminal 44. Each second electrode
terminal 44 is electrically connected to a second wire 46 having conductive properties.
Figure 2 is a schematic cross-sectional view of the conductive sheet 1 according
5 to the present embodiment. The conductive sheet 1 includes: a substrate 30 having a
first main surface and a second main surface; the first electrode pattern 10 placed on the
first main surface of the substrate 30; and the second electrode pattern 40 placed on the
second main surface of the substrate 30. The first electrode pattern 10 includes the first
conductive patterns 12, and each first conductive pattern 12 includes sub-nonconduction
10 patterns 18 electrically separated from the first conductive pattern 12. In the
embodiment of Figure 2, adjacent two of the first conductive patterns 12 are illustrated,
and each first conductive pattern 12 includes two sub-nonconduction patterns 18. The
present invention, however, is not limited thereto.
Figure 3 is a view of a state where a finger 500 is brought into contact with a
15 touch panel including the conductive sheet 1 of Figure 2. If the finger 500 is brought
into contact with the first conductive patterns 12 including the sub-nonconduction
patterns 18, lines of electric force discharged from the second conductive patterns 42
pass through the sub-nonconduction patterns 18. That is, the lines of electric force are
not closed between the first conductive patterns 12 and the second conductive patterns 42.
20 As a result, a change in electrostatic capacitance caused by the touch with finger 500 can
be reliably recognized.
Figure 4 is a view of a state where the finger 500 is brought into contact with a
touch panel including a conventional conductive sheet 101. The conductive sheet 101
includes: a substrate 300 having a first main surface and a second main surface; a first
25 electrode pattern 110 placed on the first main surface of the substrate 300; and a second
electrode pattern 400 placed on the second main surface of the substrate 300. Each first
conductive pattern 120 of the first electrode pattern 110 does not include a subnonconduction
pattern electrically separated from the first conductive pattern 120. That
is, each first conductive pattern 120 is made of a uniform conductive region. As a result,
30 lines of electric force discharged from second conductive patterns 420 are closed
between the first conductive patterns 120 and the second conductive patterns 420, and
the touch with finger 500 cannot be detected in some cases.
13
In the conductive sheet 1 according to one aspect, each first conductive pattern
12 includes, inside thereof, the sub-nonconduction patterns 18 electrically separated from
the first conductive pattern 12. Further, assuming that the area of each first conductive
pattern 12 is A and that the area of the sub-nonconduction patterns 18 is B, a relation of
5 5% < B / (A + B) < 97% is satisfied. The area A is the entire area from one end to
another end of one first conductive pattern 12, and the area B is the area of the subnonconduction
patterns 18 included from one end to another end of one first conductive
pattern 12. In another embodiment, a relation of 10% ≤ B / (A + B) ≤ 80% is satisfied.
In still another embodiment, a relation of 10% ≤ B / (A + B) ≤ 60% is satisfied.
10 <>

Figure 5 illustrates a conductive sheet 1 including a first electrode pattern 10
according to a first embodiment. In Figure 5, the first electrode pattern 10 includes two
types of first conductive patterns 12 formed by a plurality of grids 26 made of metal thin
15 wires. The plurality of grids 26 have substantially uniform shapes. Here, the
substantially uniform means not only that the shapes are completely coincident with each
other but also that the shapes and sizes of the grids 26 are seemingly the same as each
other.
Each first conductive pattern 12 has one end electrically connected to a first
20 electrode terminal 14. Each first electrode terminal 14 is electrically connected to one
end of each first wire 16. Each first wire 16 has another end electrically connected to a
terminal 20. Each first conductive pattern 12 is electrically separated by a first
nonconductive pattern 28.
Note that, in the case of the use of the conductive sheet 1 as a transparent
25 conductive film placed on the front side of a display that is required to have visibility, a
dummy pattern that includes break parts to be described later and is made of metal wires
is formed as the first nonconductive pattern 28. On the other hand, in the case of the
use of the conductive sheet 1 as a transparent conductive film placed on the front side of
a notebook computer, a touch pad, or the like that is not particularly required to have
30 visibility, a dummy pattern made of metal thin wires is not formed as the first
nonconductive pattern 28, and the first nonconductive pattern 28 exists as a space (blank).
14
The first conductive patterns 12 extend in a first direction (X direction), and are
arranged in parallel. Each first conductive pattern 12 includes slit-like subnonconduction
patterns 18 electrically separated from the first conductive pattern 12.
Each first conductive pattern 12 includes a plurality of first conductive pattern lines 22
5 divided by the sub-nonconduction patterns 18.
Note that, in the case of the use of the conductive sheet 1 as a transparent
conductive film placed on the front side of a display that is required to have visibility, a
dummy pattern that includes break parts to be described later and is made of metal wires
is formed as each sub-nonconduction pattern 18. On the other hand, in the case of the
10 use of the conductive sheet 1 as a transparent conductive film placed on the front side of
a notebook computer, a touch pad, or the like that is not particularly required to have
visibility, a dummy pattern made of metal thin wires is not formed as each subnonconduction
pattern 18, and each sub-nonconduction pattern 18 exists as a space
(blank).
15 As illustrated in the upper side of Figure 5, a first first conductive pattern 12
includes slit-like sub-nonconduction patterns 18 each having another end that is opened.
Because the another ends are opened, the first first conductive pattern 12 has a combshaped
structure. In the present embodiment, the first first conductive pattern 12
includes two sub-nonconduction patterns 18, whereby three first conductive pattern lines
20 22 are formed. The first conductive pattern lines 22 are connected to the first electrode
terminal 14, and thus have the same electric potential.
As illustrated in the lower side of Figure 5, still another first conductive pattern
12, that is, a second first conductive pattern 12 has another end at which an additional
first electrode terminal 24 is provided. Slit-like sub-nonconduction patterns 18 are
25 closed inside of the first conductive pattern 12. If the additional first electrode terminal
24 is provided, each first conductive pattern 12 can be easily checked. In the present
embodiment, the second first conductive pattern 12 includes two closed subnonconduction
patterns 18, whereby three first conductive pattern lines 22 are formed in
the first conductive pattern 12. Each first conductive pattern lines 22 is connected to
30 the first electrode terminal 14 and the additional first electrode terminal 24, and thus they
have the same electric potential. Such first conductive pattern lines are one of modified
examples of the comb-shaped structure.
15
The number of the first conductive pattern lines 22 may be two or more, and is
determined within a range of ten or less and preferably a range of seven or less, in
consideration of a relation with a pattern design of metal thin wires.
Moreover, the pattern shapes of the metal thin wires of the three first conductive
5 pattern lines 22 may be the same as each other, and may be different from each other.
In Figure 5, the shapes of the first conductive pattern lines 22 are different from each
other. In the first first conductive pattern 12, the uppermost first conductive pattern line
22 of the three first conductive pattern lines 22 is designed to extend along the first
direction (X direction) such that adjacent mountain-shaped metal wires intersect with
10 each other. The grids 26 of the uppermost first conductive pattern line 22 are not
complete, that is, each grid 26 does not have a lower apex angle. The central first
conductive pattern line 22 is designed to extend in two lines along the first direction (X
direction) such that sides of adjacent ones of the grids 26 are in contact with each other.
The lowermost first conductive pattern line 22 is designed to extend along the first
15 direction (X direction) such that apex angles of adjacent ones of the grids 26 are in
contact with each other and that sides of the grids 26 are extended.
In the second first conductive pattern 12, the uppermost first conductive pattern
line 22 and the lowermost first conductive pattern line 22 have substantially the same
grid shape, and are thus designed to extend in two lines along the first direction (X
20 direction) such that sides of adjacent ones of the grids 26 are in contact with each other.
In the second first conductive pattern 12, the central first conductive pattern line 22 is
designed to extend along the first direction (X direction) such that apex angles of
adjacent ones of the grids 26 are in contact with each other and that sides of the grids 26
are extended.
25 In one embodiment, assuming that the area of each first conductive pattern 12 is
A1 and that the area of the sub-nonconduction patterns 18 is B1, it is preferable that 10%
≤ B1 / (A1 + B1) ≤ 80% be satisfied, and it is further preferable that 40% ≤ B1 / (A1 +
B1) ≤ 60% be satisfied. If this range is satisfied, a difference in electrostatic
capacitance between when a finger is in contact with the conductive sheet 1 and when a
30 finger is not in contact with the conductive sheet 1 can be made larger. That is, the
detection accuracy of the touch with finger can be improved.
16
Note that each area can be obtained in the following manner. A virtual line in
contact with a plurality of the first conductive pattern lines 22 is drawn, and the first
conductive pattern 12 and the sub-nonconduction patterns 18 surrounded by this virtual
line are calculated, whereby each area can be obtained.
5 Assuming that the total width of the widths of the first conductive pattern lines
22 is Wa and that the sum of: the sum of the widths of the sub-nonconduction patterns
18; and the width of the first nonconductive pattern 28 is Wb, it is preferable that a
condition of the following expression (W1-1) be satisfied, it is more preferable that a
condition of the following expression (W1-2) be satisfied, and it is more preferable that a
10 condition of the following expression (W1-3) be satisfied. Moreover, it is preferable
that a condition of the following expression (W2-1) be satisfied, it is more preferable that
a condition of the following expression (W2-2) be satisfied, and it is more preferable that
a condition of the following expression (W2-3) be satisfied.
10% ≤ (Wa / (Wa + Wb)) × 100 ≤ 80% •••••• (W1-1)
15 10% ≤ (Wa / (Wa + Wb)) × 100 ≤ 60% •••••• (W1-2)
30% ≤ (Wa / (Wa + Wb)) × 100 ≤ 55% •••••• (W1-3)
Wa ≤ (Wa + Wb) / 2 ••••••••••••••••••••••••••••••••• (W2-1)
(Wa + Wb) / 5 ≤ Wa ≤ (Wa + Wb) / 2 •••••• (W2-2)
(Wa + Wb) / 3 ≤ Wa ≤ (Wa + Wb) / 2 •••••• (W2-3)
20 If the sum of the widths of the first conductive pattern lines 22 is small, the
touch panel response tends to be slower due to an increase in electrode resistance,
whereas the recognition performance for a contacting finger tends to be higher due to a
decrease in electrostatic capacitance. On the other hand, if the sum of the widths of the
first conductive pattern lines 22 is large, the touch panel response tends to be faster due
25 to a decrease in electrode resistance, whereas the recognition performance for a
contacting finger tends to be lower due to an increase in electrostatic capacitance.
These are in a trade-off relation, but, if the range of any of the above expressions is
satisfied, the touch panel response and the recognition performance for a finger can be
optimized.
30 Here, as illustrated in Figure 5, the sum of widths a1, a2, and a3 of the first
conductive pattern lines 22 corresponds to Wa, and the sum of widths b1 and b2 of the
17
sub-nonconduction patterns 18 and a width b3 of the first nonconductive pattern 28
corresponds to Wb.
Figure 5 illustrates one conductive sheet 1 in which the first first conductive
pattern 12 not including the additional first electrode terminal 24 and the second first
conductive pattern 12 including the add 5 itional first electrode terminal 24 are formed on
the same plane. However, the first first conductive pattern 12 and the second first
conductive pattern 12 do not necessarily need to be mixedly formed, and only any one of
the first first conductive pattern 12 and the second first conductive pattern 12 may be
formed.
10 In another embodiment, further preferably, assuming that the total width of the
widths of the first conductive pattern lines 22 is Wa and that the total width of: the sum
of the widths of the sub-nonconduction patterns 18; and the width of the first
nonconductive pattern 28 is Wb, relations of 1.0 mm ≤ Wa ≤ 5.0 mm and 1.5 mm ≤ Wb
≤ 5.0 mm are satisfied. In consideration of the average size of a human finger, if Wa
15 and Wb are respectively set within these ranges, the contact position can be more
accurately detected. Further, for the value of Wa, 1.5 mm ≤ Wa ≤ 4.0 mm is preferable,
and 2.0 mm ≤ Wa ≤ 2.5 mm is further preferable. Furthermore, for the value of Wb, 1.5
mm ≤ Wb ≤ 4.0 mm is preferable, and 2.0 mm ≤ Wb ≤ 3.0 mm is further preferable.
The metal thin wires that form the first electrode pattern 10 each have a wire
20 width of, for example, 30 μm or less. The metal thin wires that form the first electrode
pattern 10 are made of, for example, metal materials such as gold, silver, and copper and
conductive materials such as metal oxides.
It is desirable that the wire width of each metal thin wire be 30 μm or less,
preferably 15 μm or less, more preferably 10 μm or less, more preferably 9 μm or less,
25 and more preferably 7 μm or less, and be 0.5 μm or more and preferably 1 μm or more.
The first electrode pattern 10 includes the plurality of grids 26 made of metal
thin wires that intersect with each other. Each grid 26 includes an opening region
surrounded by the metal thin wires. Each grid 26 has one side having a length of 900
μm or less and 250 μm or more. It is desirable that the length of one side thereof be 700
30 μm or less and 300 μm or more.
In the first conductive patterns 12 of the present embodiment, the opening ratio
is preferably 85% or more, further preferably 90% or more, and most preferably 95% or
18
more, in terms of the visible light transmittance. The opening ratio corresponds to the
percentage of a translucent portion of the first electrode pattern 10 excluding the metal
thin wires, in a predetermined region.
In the above-mentioned conductive sheet 1, each grid 26 has a substantially
5 rhomboid shape. Alternatively, each grid 26 may have other polygonal shapes.
Moreover, the shape of one side of each grid 26 may be a curved shape or a circular arc
shape instead of a straight shape. In the case of the circular arc shape, for example,
opposing two of the sides of each grid 26 may each have a circular arc shape convex
outward, and another opposing two of the sides thereof may each have a circular arc
10 shape convex inward. Moreover, the shape of each side of each grid 26 may be a wavy
shape in which a circular arc convex outward and a circular arc convex inward are
alternately continuous. As a matter of course, the shape of each side thereof may be a
sine curve.
Next, examples of other first electrode patterns of the first embodiment are
15 described with reference to Figures 6 to 11.
Figure 6 illustrates the first electrode pattern 10 according to embodiment. The
first electrode pattern 10 includes the first conductive patterns 12 formed by the large
number of grids 26 made of metal thin wires. The first conductive patterns 12 extend in
the first direction (X direction). Each first conductive pattern 12 includes the slit-like
20 sub-nonconduction patterns 18 for electrically separating the first conductive pattern 12.
Each first conductive pattern 12 includes the plurality of first conductive pattern lines 22
divided by the sub-nonconduction patterns 18. As illustrated in Figure 6, each first
conductive pattern line 22 is formed by the plurality of grids 26 that are arranged in one
line in the first direction (X direction). The first conductive pattern lines 22 are
25 electrically connected to each other by the large number of grids 26 that are made of
metal thin wires and are placed at an end.
As illustrated in Figure 6, the first conductive pattern lines 22 respectively
extend in the first direction (X direction) from the first grid, the third grid, and the fifth
grid of the five grids 26 that are arranged in the second direction (Y direction) at the end.
30 As a result, each of the widths a1, a2, and a3 of the first conductive pattern 12 and each
of the widths b1 and b2 of the sub-nonconduction patterns 18 are substantially the same
length (as long as the diagonal of each grid 26).
19
Figure 7 illustrates the first electrode pattern 10 according to embodiment. The
same configurations as those described above are designated by the same reference
numerals or reference characters, and description thereof may be omitted. The first
electrode pattern 10 includes the first conductive patterns 12 formed by the large number
of grids 26 made of metal thin wires. 5 The first conductive patterns 12 extend in the first
direction (X direction). Each first conductive pattern 12 includes the slit-like subnonconduction
patterns 18 for electrically separating the first conductive pattern 12. As
illustrated in Figure 7, each first conductive pattern line 22 is formed by the plurality of
grids 26 that are arranged in one line in the first direction (X direction).
10 Unlike Figure 6, in Figure 7, the first conductive pattern lines 22 respectively
extend in the first direction (X direction) from the first grid, between the third grid and
the fourth grid, and the sixth grid of the six grids 26 that are arranged in the second
direction (Y direction). That is, compared with Figure 6, the plurality of first
conductive pattern lines 22 in Figure 7 are arranged at a pitch longer by half the size of
15 each grid 26. As a result, the widths b1 and b2 of the sub-nonconduction patterns 18
are larger than the widths a1, a2, and a3 of the first conductive pattern 12. The widths
b1 and b2 of the sub-nonconduction patterns 18 are 1.5 times longer than the diagonal of
each grid 26, and the widths a1, a2, and a3 of the first conductive pattern 12 are as long
as the diagonal of each grid 26. In the first electrode pattern 10 of Figure 7, the width
20 of each sub-nonconduction pattern 18 is larger.
Figure 8 illustrates the first electrode pattern 10 according to embodiment. The
same configurations as those of the first electrode pattern 10 described above are
designated by the same reference numerals or reference characters, and description
thereof may be omitted. The first electrode pattern 10 includes the first conductive
25 patterns 12 formed by the large number of grids 26 made of metal thin wires. The first
conductive patterns 12 extend in the first direction (X direction). Each first conductive
pattern 12 includes the slit-like sub-nonconduction patterns 18 for electrically separating
the first conductive pattern 12. As illustrated in Figure 8, each first conductive pattern
line 22 is formed by the plurality of grids 26 that are arranged in two lines in the first
30 direction (X direction).
In Figure 8, the first conductive pattern lines 22 respectively extend in two lines
in the first direction (X direction) from the first grid, the third grid and the fourth grid,
20
and the fifth grid and the sixth grid of the six grids 26 that are arranged in the second
direction (Y direction). As a result, the widths b1 and b2 of the sub-nonconduction
patterns 18 are smaller than the widths a1, a2, and a3 of the first conductive pattern 12.
The widths b1 and b2 of the sub-nonconduction patterns 18 are as long as the diagonal of
5 each grid 26, and the widths a1, a2, and a3 of the first conductive pattern 12 are 1.5 times
longer than the diagonal of each grid 26. In the first electrode pattern 10 of Figure 8,
the width of the first conductive pattern 12 is larger.
Figure 9 illustrates the first electrode pattern 10 according to embodiment. The
same configurations as those of the first electrode pattern 10 described above are
10 designated by the same reference numerals or reference characters, and description
thereof may be omitted. The first electrode pattern 10 illustrated in Figure 9 has
basically the same structure as that of the first electrode pattern 10 illustrated in Figure 8.
Figure 9 is different from Figure 6 in the following point. In Figure 9, joining parts 27
that electrically connect the first conductive pattern lines 22 to each other are provided at
15 locations other than ends of the first conductive pattern lines 22. Because the joining
parts 27 are provided, even if the first conductive pattern lines 22 become longer and the
wiring resistance thus becomes larger, the first conductive pattern lines 22 can be kept at
the same electric potential.
Figure 10 illustrates the first electrode pattern 10 according to embodiment.
20 The same configurations as those of the first electrode pattern 10 described above are
designated by the same reference numerals or reference characters, and description
thereof may be omitted. The first electrode pattern 10 illustrated in Figure 10 has
basically the same structure as that of the first electrode pattern 10 illustrated in Figure 6.
Unlike Figure 6, in Figure 10, the number of the first conductive pattern lines 22 is not
25 three but two. The finger detection accuracy can be made higher as long as the number
of the first conductive pattern lines 22 of the first electrode pattern 10 is two or more.
Figure 11 illustrates the first electrode pattern 10 according to embodiment.
The same configurations as those of the first electrode pattern 10 described above are
designated by the same reference numerals or reference characters, and description
30 thereof may be omitted. The first electrode pattern 10 illustrated in Figure 11 has
basically the same structure as that of the first electrode pattern 10 illustrated in Figure 6.
Unlike Figure 6, in Figure 11, the number of the first conductive pattern lines 22 is not
21
three but four. The finger detection accuracy can be made higher as long as the number
of the first conductive pattern lines 22 of the first electrode pattern 10 is two or more, for
example, even five or more.
Note that, in Figure 6 to Figure 11, each area can be obtained in the following
manner. A virtual line in contact 5 with a plurality of the first conductive pattern lines 22
is drawn, and the first conductive pattern 12 and the sub-nonconduction patterns 18
surrounded by this virtual line are calculated, whereby each area can be obtained.

Figure 12 illustrates a conductive sheet 1 including a first electrode pattern 10
10 according to another embodiment. Configurations similar to those in Figure 5 are
designated by the same reference numerals or reference characters, and description
thereof may be omitted. In Figure 12, the first electrode pattern 10 includes two types
of first conductive patterns 12 formed by a plurality of grids 26 made of metal thin wires.
The plurality of grids 26 have substantially uniform shapes. Here, the substantially
15 uniform means not only that the shapes are completely coincident with each other but
also that the shapes and sizes of the grids 26 are seemingly the same as each other.
Each first conductive pattern 12 has one end electrically connected to a first
electrode terminal 14. Each first electrode terminal 14 is electrically connected to one
end of each first wire 16. Each first wire 16 has another end electrically connected to a
20 terminal 20. Each first conductive pattern 12 is electrically separated by a first
nonconductive pattern 28.
Note that, in the case where the conductive sheet 1 is used as a transparent
conductive film placed on the front side of a display that is required to have visibility, a
dummy pattern that includes break parts to be described later and is made of metal wires
25 is formed as the first nonconductive pattern 28. On the other hand, in the case where
the conductive sheet 1 is used as a transparent conductive film placed on the front side of
a notebook computer, a touch pad, or the like that is not particularly required to have
visibility, a dummy pattern made of metal thin wires is not formed as the first
nonconductive pattern 28, and the first nonconductive pattern 28 exists as a space (blank).
30 As illustrated in the upper side of Figure 12, one first conductive pattern, that is,
a first first conductive pattern 12 does not include an additional first electrode terminal
24. On the other hand, as illustrated in the lower side of Figure 12, a first first
22
conductive pattern 12 includes still another first conductive pattern, that is, the additional
first electrode terminal 24. Figure 12 illustrates one conductive sheet 1 in which the
first first conductive pattern 12 not including the additional first electrode terminal 24
and the second first conductive pattern 12 including the additional first electrode terminal
24 are formed on the same 5 plane. However, the first first conductive pattern 12 and the
second first conductive pattern 12 do not necessarily need to be mixedly formed, and
only any one of the first first conductive pattern 12 and the second first conductive
pattern 12 may be formed.
In the present embodiment, each first conductive pattern 12 has X-shaped
10 structures with cyclical intersections. This cycle can be selected as appropriate.
Assuming that the area of each first conductive pattern 12 is A2 and that the area of the
sub-nonconduction patterns 18 is B2, a relation of 10% ≤ B2 / (A2 + B2) ≤ 80% is
satisfied. In another embodiment, a relation of 20% ≤ B2 / (A2 + B2) ≤ 50% is satisfied.
In still another embodiment, a relation of 30% ≤ B2 / (A2 + B2) ≤ 50% is satisfied.
15 Note that each area can be obtained in the following manner. The area of each
first conductive pattern 12 is obtained by calculating the unit area of each grid 26 × the
number of the grids 26. The area of the sub-nonconduction patterns 18 is obtained by
placing virtual grids 26 and calculating the unit area of each virtual grid 26 × the number
of the grids 26.
20 Note that, in the case where the conductive sheet 1 is used as a transparent
conductive film placed on the front side of a display that is required to have visibility, a
dummy pattern that includes break parts to be described later and is made of metal wires
is formed as each sub-nonconduction pattern 18. On the other hand, in the case where
the conductive sheet 1 is used as a transparent conductive film placed on the front side of
25 a notebook computer, a touch pad, or the like that is not particularly required to have
visibility, a dummy pattern made of metal thin wires is not formed as each subnonconduction
pattern 18, and each sub-nonconduction pattern 18 exists as a space
(blank).
If this range is satisfied, a difference in electrostatic capacitance between when a
30 finger contacts the conductive sheet 1 and when a finger does not contact the conductive
sheet 1 can be made larger. That is, the detection accuracy of the touch with finger can
be improved.
23
The wire width of the metal thin wires that form the first electrode pattern 10
and the material thereof are substantially the same as those in the embodiment of Figure
5. Moreover, the grids 26 of the metal thin wires that form the first electrode pattern 10
are substantially the same as those in the embodiment of Figure 5.
5 Next, examples of other first electrode patterns of the second embodiment are
described with reference to Figures 13 to 22.
Figure 13 illustrates the first electrode pattern 10 according to another
embodiment. The same configurations as those of the first electrode pattern 10
described above are designated by the same reference numerals or reference characters,
10 and description thereof may be omitted. The first electrode pattern 10 includes the first
conductive patterns 12 formed by the large number of grids 26 made of metal thin wires.
Each first conductive pattern 12 includes the plurality of sub-nonconduction patterns 18
along the first direction, to thereby have X-shaped structures with cyclical intersections.
In the first conductive pattern 12 illustrated in Figure 13, each sub15
nonconduction pattern 18 is surrounded and defined by four sides. Each of the four
sides is formed by linearly arranging the plurality of grids 26 with sides of adjacent ones
of the grids 26 being connected to each other. Each sub-nonconduction pattern 18 is
surrounded by the plurality of linearly arranged grids 26, whereby a diamond pattern
(rhomboid pattern) is formed. Adjacent diamond patterns are electrically connected to
20 each other. In Figure 13, adjacent diamond patterns are electrically connected to each
other with the intermediation of sides of the grids 26.
Figure 14 illustrates the first electrode pattern 10 according to another
embodiment. The same configurations as those of the first electrode pattern 10
described above are designated by the same reference numerals or reference characters,
25 and description thereof may be omitted. The first electrode pattern 10 includes the first
conductive patterns 12 formed by the large number of grids 26 made of metal thin wires.
Each first conductive pattern 12 includes the plurality of sub-nonconduction patterns 18
along the first direction, to thereby have X-shaped structures with cyclical intersections.
In the first conductive pattern 12 illustrated in Figure 14, each sub30
nonconduction pattern 18 is surrounded and defined by four sides. Each of the four
sides is formed by linearly arranging, in multiple stages, the plurality of grids 26 with
24
sides of adjacent ones of the grids 26 being connected to each other. In Figure 14, each
of the four sides is formed in two stages, but is not limited to the two stages.
Figure 15 illustrates the first electrode pattern 10 according to another
embodiment. The same configurations as those of the first electrode pattern 10
5 described above are designated by the same reference numerals or reference characters,
and description thereof may be omitted. The first electrode pattern 10 includes the first
conductive patterns 12 formed by the large number of grids 26 made of metal thin wires.
Each first conductive pattern 12 includes the plurality of sub-nonconduction patterns 18
along the first direction, to thereby have X-shaped structures with cyclical intersections.
10 In the first conductive pattern 12 illustrated in Figure 15, each subnonconduction
pattern 18 is surrounded and defined by six sides. Four of the six sides
are formed by linearly arranging the plurality of grids 26 with sides of adjacent ones of
the grids 26 being connected to each other. Two of the six sides are formed by linearly
arranging the plurality of grids 26 with apex angles of adjacent ones of the grids 26 being
15 connected to each other.
Figure 16 illustrates the first electrode pattern 10 according to another
embodiment. The same configurations as those of the first electrode pattern 10
described above are designated by the same reference numerals or reference characters,
and description thereof may be omitted. The first electrode pattern 10 includes the first
20 conductive patterns 12 formed by the large number of grids 26 made of metal thin wires.
Each first conductive pattern 12 includes the plurality of sub-nonconduction patterns 18
along the first direction, to thereby have X-shaped structures with cyclical intersections.
The first conductive pattern 12 illustrated in Figure 16 is the same in the shape
of each sub-nonconduction pattern 18 as the first conductive pattern 12 illustrated in
25 Figure 13. However, unlike Figure 13, in Figure 16, adjacent diamond patterns are
electrically connected to each other at apex angles of the grids 26, that is, at one point.
The shape of each sub-nonconduction pattern 18 is not limited to the diamond pattern.
Figure 17 illustrates the first electrode pattern 10 according to another
embodiment. The same configurations as those of the first electrode pattern 10
30 described above are designated by the same reference numerals or reference characters,
and description thereof may be omitted. The first electrode pattern 10 includes the first
conductive patterns 12 formed by the large number of grids 26 made of metal thin wires.
25
Each first conductive pattern 12 includes the plurality of sub-nonconduction patterns 18
along the first direction, to thereby have X-shaped structures with cyclical intersections.
In Figure 17, the shapes of diamond patterns are alternately different, and the
sizes of adjacent ones of the sub-nonconduction patterns 18 are different. That is, the
same shape appears every two cycles. However, 5 not limited to every two cycles, the
same shape may appear every three cycles or every four cycles.
Figure 18 illustrates the first electrode pattern 10 according to another
embodiment. The same configurations as those of the first electrode pattern 10
described above are designated by the same reference numerals or reference characters,
10 and description thereof may be omitted. The first electrode pattern 10 includes the first
conductive patterns 12 formed by the large number of grids 26 made of metal thin wires.
Each first conductive pattern 12 includes the plurality of sub-nonconduction patterns 18
along the first direction, to thereby have X-shaped structures with cyclical intersections.
The first conductive pattern 12 illustrated in Figure 18 has basically the same
15 shape as that of the first conductive pattern 12 illustrated in Figure 13. However, the
grid 26 located at each apex angle of a diamond pattern is provided with protruding wires
31 made of metal thin wires.
Figure 19 illustrates the first electrode pattern 10 according to another
embodiment. The same configurations as those of the first electrode pattern 10
20 described above are designated by the same reference numerals or reference characters,
and description thereof may be omitted. The first electrode pattern 10 includes the first
conductive patterns 12 formed by the large number of grids 26 made of metal thin wires.
Each first conductive pattern 12 includes the plurality of sub-nonconduction patterns 18
along the first direction, to thereby have X-shaped structures with cyclical intersections.
25 The first conductive pattern 12 illustrated in Figure 19 has basically the same
shape as that of the first conductive pattern 12 illustrated in Figure 13. However, the
grids 26 that form each side of a diamond pattern are provided with the protruding wires
31 made of metal thin wires.
The first electrode pattern 10 illustrated in each of Figures 18 and 19 is provided
30 with the protruding wires 31, and hence a sensor region for detecting the contact of a
finger can be widened.
26
Figure 20 illustrates the first electrode pattern 10 according to another
embodiment. The same configurations as those of the first electrode pattern 10
described above are designated by the same reference numerals or reference characters,
and description thereof may be omitted. The first electrode pattern 10 includes the first
5 conductive patterns 12 formed by the large number of grids 26 made of metal thin wires.
Each first conductive pattern 12 includes the plurality of sub-nonconduction patterns 18
along the first direction, to thereby have X-shaped structures in which grids 26 are not
present at the intersection points. In the first conductive pattern 12 illustrated in Figure
20, the plurality of grids 26 are arranged in a zigzag manner. Two groups of the grids
10 arranged in the zigzag manner are opposedly placed so as not to contact each other, and
hence the X-shaped structures without intersection points are formed. Because the Xshaped
structures are formed by the two groups of the grids arranged in the zigzag
manner, the electrode pattern can be made thinner, and a contact position of a finger can
be finely detected.
15 Figure 21 illustrates the first electrode pattern 10 according to another
embodiment. The same configurations as those of the first electrode pattern 10
described above are designated by the same reference numerals or reference characters,
and description thereof may be omitted. The first electrode pattern 10 includes the first
conductive patterns 12 formed by the large number of grids 26 made of metal thin wires.
20 Each first conductive pattern 12 includes the plurality of sub-nonconduction patterns 18
along the first direction, to thereby have X-shaped structures in which the grids 26 are
not present at the intersection points. In the first conductive pattern 12 illustrated in
Figure 21, the plurality of grids 26 are placed in each corner part in which two groups of
the grids arranged in a zigzag manner approach each other, unlike the first conductive
25 pattern 12 illustrated in Figure 20.
Figure 22 illustrates the first electrode pattern 10 according to another
embodiment. The same configurations as those of the first electrode pattern 10
described above are designated by the same reference numerals or reference characters,
and description thereof may be omitted. The first electrode pattern 10 of Figure 22
30 includes two first conductive patterns 12 formed by the large number of grids 26 made of
metal thin wires. Each first conductive pattern 12 includes the sub-nonconduction
27
patterns 18 along the first direction, to thereby have X-shaped structures with cyclical
intersections.
As illustrated in Figure 22, the upper first conductive pattern 12 includes the
sub-nonconduction patterns 18 having the same shape along the first direction (X
5 direction). Moreover, as illustrated in Figure 22, the lower first conductive pattern 12
includes the sub-nonconduction patterns 18 having the same shape along the first
direction. Meanwhile, the shapes of the sub-nonconduction patterns 18 are different
between the upper first conductive pattern 12 and the lower first conductive pattern 12.
The first conductive patterns 12 having different shapes are alternately arranged. Such
10 arrangement as described above secures the degree of freedom in arrangement of the first
electrode pattern 10.
Note that, in the pattern illustrated in each of Figure 13 to Figure 22, the area of
each first conductive pattern 12 is obtained by calculating the unit area of each grid 26 ×
the number of the grids 26. The area of the sub-nonconduction patterns 18 is obtained
15 by placing virtual grids 26 and calculating the unit area of each virtual grid 26 × the
number of the grids 26.
<>
Next, a second electrode pattern is described with reference to the drawings.
As illustrated in Figure 23, a second electrode pattern 40 is formed by a large number of
20 grids made of metal thin wires. The second electrode pattern 40 includes a plurality of
second conductive patterns 42 that extend in a second direction (Y direction) orthogonal
to the first direction (X direction) and are arranged in parallel. Each second
conductive pattern 42 is electrically separated by a second nonconductive pattern 58.
Note that, in the case where the conductive sheet 1 is used as a transparent
25 conductive film placed on the front side of a display that is required to have visibility, a
dummy pattern that includes break parts to be described later and is made of metal wires
is formed as the second nonconductive pattern 58. On the other hand, in the case where
the conductive sheet 1 is used as a transparent conductive film placed on the front side of
a notebook computer, a touch pad, or the like that is not particularly required to have
30 visibility, a dummy pattern made of metal thin wires is not formed as the second
nonconductive pattern 58, and the second nonconductive pattern 58 exists as a space
(blank).
28
Each second conductive pattern 42 is electrically connected to a second
electrode terminal 44. Each second electrode terminal 44 is electrically connected to a
second wire 46 having conductive properties. Each second conductive pattern 42 has
one end electrically connected to the second electrode terminal 44. Each second
electrode te 5 rminal 44 is electrically connected to one end of each second wire 46. Each
second wire 46 has another end electrically connected to a terminal 50. Each second
conductive pattern 42 has a strip-shaped structure having a substantially constant width
along the second direction. However, each second conductive pattern 42 is not limited
to the strip shape.
10 The second electrode pattern 40 may be provided with an additional second
electrode terminal 54 at another end thereof. If the additional second electrode terminal
54 is provided, each second conductive pattern 42 can be easily checked.
Figure 23 illustrates one conductive sheet 1 in which the second conductive
pattern 42 not including the additional second electrode terminal 54 and the second
15 conductive pattern 42 including the additional second electrode terminal 54 are formed
on the same plane. However, such two types of the second conductive patterns 42 do
not necessarily need to be mixedly formed, and only one of the two types of the second
conductive patterns 42 may be formed.
The metal thin wires that form the second electrode pattern 40 have substantially
20 the same wire width and are made of substantially the same material as the metal thin
wires that form the first electrode pattern 10. The second electrode pattern 40 includes
a plurality of grids 56 made of metal thin wires that intersect with each other, and each
grid 56 has substantially the same shape as that of each grid 26. The length of one side
of each grid 56 and the opening ratio of each grid 56 are equivalent to those of each grid
25 26.
<>
Figure 24 is a plan view of the conductive sheet 1 in which the first electrode
pattern 10 including the first conductive patterns 12 each having the comb-shaped
structure and the second electrode pattern 40 including the second conductive patterns 42
30 each having the strip-shaped structure are opposedly placed. The first conductive
patterns 12 and the second conductive patterns 42 are orthogonal to each other, and the
29
first electrode pattern 10 and the second electrode pattern 40 form a combination pattern
70.
In this combination pattern, the first electrode pattern 10 not including a dummy
pattern and the second conductive patterns 42 not including a dummy pattern are
5 combined with each other.
In the combination pattern 70, the grids 26 and the grids 56 form small grids 76
in top view. That is, the intersection parts of the grids 26 are respectively placed in
substantially the centers of the opening regions of the grids 56. Note that each small
grid 76 has one side having a length of 125 μm or more and 450 μm or less, and
10 preferably has one side having a length of 150 μm or more and 350 μm or less. This
corresponds to half the length of one side of each of the grids 26 and the grids 56.
Figure 25 is a plan view of the conductive sheet 1 in which the first electrode
pattern 10 including the first conductive patterns 12 each having the X-shaped structures
and the second electrode pattern 40 including the second conductive patterns 42 each
15 having the strip-shaped structure are opposedly placed. The first conductive patterns 12
and the second conductive patterns 42 are orthogonal to each other, and the first
electrode pattern 10 and the second electrode pattern 40 form the combination pattern 70.
In the combination pattern 70, the grids 26 and the grids 56 form the small grids 76,
similarly to the first embodiment.
20 <>
Figure 26 is a plan view illustrating an example of the first electrode pattern 10
of the first embodiment, in which dummy patterns are explicitly illustrated. The first
nonconductive pattern 28 is made of metal thin wires similarly to the first conductive
patterns 12, and includes the break parts. Moreover, the sub-nonconduction patterns 18
25 formed in each first conductive pattern 12 are made of metal thin wires similarly to the
first conductive patterns 12, and include the break parts. The sub-nonconduction
patterns 18 and the first nonconductive pattern 28 are made of metal thin wires including
the break parts, and thus are each formed as a so-called dummy pattern electrically
separated from the first conductive patterns 12. If the dummy patterns are formed, the
30 first electrode pattern 10 is formed by the grids of the metal thin wires placed at regular
intervals. This can prevent a decrease in visibility. Note that, in Figure 26, the
dummy patterns are portions surrounded by broken lines, and are at positions
30
respectively corresponding to the sub-nonconduction patterns 18 and the first
nonconductive pattern 28.
Figure 27 is an enlarged view of a portion surrounded by a circle in Figure 26.
As illustrated in Figure 27, the metal thin wires that form the first nonconductive pattern
5 28 and the sub-nonconduction pattern 18 include break parts 29, and are electrically
separated from the first conductive pattern 12. It is preferable that each break part 29
be formed in a portion other than each intersection part of the metal thin wires.
In Figure 27, in order to clarify the first conductive pattern 12, the first
nonconductive pattern 28, and the sub-nonconduction pattern 18, the wire width of the
10 first conductive pattern 12 is exaggeratingly thickened, and the wire widths of the first
nonconductive pattern 28 and the sub-nonconduction pattern 18 are exaggeratingly
thinned.
All the grids 26 that form the first nonconductive pattern 28 and the subnonconduction
pattern 18 do not necessarily need to include the break parts 29. The
15 length of each break part 29 is preferably 60 μm or less, and is more preferably 10 to 50
μm, 15 to 40 μm, and 20 to 40 μm. Such dummy patterns can be formed in the first
electrode pattern 10 of the first embodiment illustrated in Figure 5 to Figure 11.
Figure 28 is a plan view illustrating an example of the first electrode pattern 10
of the second embodiment including dummy patterns. The first nonconductive pattern
20 28 is made of metal thin wires similarly to the first conductive patterns 12. Moreover,
the sub-nonconduction patterns 18 formed in each first conductive pattern 12 are made of
metal thin wires similarly to the first conductive patterns 12. The sub-nonconduction
patterns 18 and the first nonconductive pattern 28 are made of metal thin wires, and thus
are each formed as a so-called dummy pattern electrically separated from the first
25 conductive patterns 12. In Figure 28, the dummy patterns are portions surrounded by
thick solid lines, and are at positions respectively corresponding to the subnonconduction
patterns 18 and the first nonconductive pattern 28. If the dummy
patterns are formed, the first electrode pattern 10 is formed by the grids of the metal thin
wires placed at regular intervals. This can prevent a decrease in visibility.
30 Also in Figure 28, the metal thin wires that form the dummy patterns as the first
nonconductive pattern 28 and the sub-nonconduction patterns 18 include the break parts,
and are electrically separated from the first conductive pattern 12. It is preferable that
31
each break part be formed in a portion other than each intersection part of the metal thin
wires. Such dummy patterns can be formed in the first electrode pattern 10 of the first
embodiment illustrated in Figure 12 to Figure 22.
Figure 29 is a plan view illustrating an example of the second electrode pattern
5 40 including a dummy pattern. The second nonconductive pattern 58 is made of metal
thin wires similarly to the second conductive patterns 42, and includes the break parts.
The second nonconductive pattern 58 is made of metal thin wires, and thus is formed as a
so-called dummy pattern electrically separated from the second conductive patterns 42.
In Figure 29, the dummy pattern is a portion surrounded by a broken line, and is at a
10 position corresponding to the second nonconductive pattern 58. If the dummy pattern is
formed, the second electrode pattern 40 is formed by the grids of the metal thin wires
placed at regular intervals. This can prevent a decrease in visibility.
Figure 30 is an enlarged view of a portion surrounded by a circle in Figure 29.
As illustrated in Figure 30, the metal thin wires that form the second nonconductive
15 pattern 58 include break parts 59, and are electrically separated from the second
conductive patterns 42. It is preferable that each break part 59 be formed at a portion
other than each intersection part of the metal thin wires.
In Figure 30, in order to clarify the second conductive patterns 42 and the
second nonconductive pattern 58, the wire widths of the second conductive patterns 42
20 are exaggeratingly thickened, and the wire width of the second nonconductive pattern 58
is exaggeratingly thinned. Note that the length of each break part 59 is substantially the
same as that of each break part 29 in Figure 27.
Figure 31 explicitly illustrates the first nonconductive pattern 28 and the first
conductive patterns 12 that are made of metal thin wires. Moreover, the break parts are
25 provided between the first conductive patterns 12, and the sub-nonconduction patterns 18
formed as dummy patterns made of metal thin wires are explicitly illustrated. In Figure
31, the dummy patterns are portions surrounded by broken lines, and are at positions
respectively corresponding to the sub-nonconduction patterns 18 and the second
nonconductive pattern 58. If the dummy patterns are formed, the first electrode pattern
30 10 is formed by the grids of the metal thin wires placed at regular intervals. This can
prevent a decrease in visibility. This is particularly effective in the case where the
32
conductive sheet 1 is placed on the front side of a display or the like that is required to
have visibility.
Similarly, the second nonconductive pattern 58 is made of metal thin wires
similarly to the second conductive patterns 42. The second nonconductive pattern 58 is
5 made of metal thin wires, and thus is formed as a so-called dummy pattern electrically
separated from the second conductive patterns 42. If the dummy pattern is formed, the
second electrode pattern 40 is formed by the grids of the metal thin wires placed at
regular intervals. This can prevent a decrease in visibility. The dummy pattern made
of the metal thin wires includes the break parts, and is electrically separated from the
10 first conductive patterns 12 and the second conductive patterns 42.
Figure 32 is a plan view of the conductive sheet 1 in which the first electrode
pattern 10 including dummy patterns and the second electrode pattern 40 including a
dummy pattern are placed such that the first conductive patterns 12 and the second
conductive patterns 42 are orthogonal to each other. Each first conductive pattern 12
15 includes the sub-nonconduction patterns 18 along the first direction at predetermined
intervals, to thereby have X-shaped structures with cyclical intersections. The first
electrode pattern 10 and the second electrode pattern 40 form the combination pattern 70.
The first nonconductive pattern 28, the sub-nonconduction patterns 18, and the second
nonconductive pattern 58 are made of metal thin wires. In Figure 32, the dummy
20 patterns are portions surrounded by thick solid lines, and are at positions respectively
corresponding to the first nonconductive pattern 28, the sub-nonconduction patterns 18,
and the second nonconductive pattern 58. If the dummy patterns are formed, the first
electrode pattern 10 is formed by the grids of the metal thin wires placed at regular
intervals. This can prevent a decrease in visibility.
25 Next, a method of manufacturing the conductive sheet 1 is described.
In the case of manufacturing the conductive sheet 1, for example, a
photosensitive material having an emulsion layer containing photosensitive silver halide
is exposed to light and developed on the first main surface of the transparent substrate 30,
and a metal silver part (metal thin wires) and a light transmissive part (opening regions)
30 are respectively formed in the exposed part and the unexposed part, whereby the first
electrode pattern 10 may be formed. Note that the metal silver part is further physically
33
developed and/or plated, whereby the metal silver part may be caused to support
conductive metal.
Alternatively, a resist pattern is formed by exposing to light and developing a
photoresist film on copper foil formed on the first main surface of the transparent
5 substrate 30, and the copper foil exposed on the resist pattern is etched, whereby the first
electrode pattern 10 may be formed.
Alternatively, a paste containing metal fine grains is printed on the first main
surface of the transparent substrate 30, and the paste is plated with metal, whereby the
first electrode pattern 10 may be formed.
10 The first electrode pattern 10 may be formed by printing on the first main
surface of the transparent substrate 30, using a screen printing plate or a gravure printing
plate. Alternatively, the first electrode pattern 10 may be formed on the first main
surface of the transparent substrate 30, according to an inkjet process.
The second electrode pattern 40 can be formed on the second main surface of
15 the substrate 30, according to a manufacturing method similar to that for the first
electrode pattern 10.
The first electrode pattern 10 and the second electrode pattern 40 may be formed
by: forming a photosensitive layer to be plated on the transparent substrate 30 using a
plating preprocessing material; exposing the formed layer to light to develop it; and
20 plating the layer so as to form a metal part and a light transmissive part respectively in
the exposed part and the unexposed part. Note that the metal part may be further
physically developed and/or plated so that the metal part can be caused to support
conductive metal. Note that more specific contents thereof are described in, for
example, Japanese Patent Application Laid-Open No. 2003-213437, No. 2006-64923, No.
25 2006-58797, and No. 2006-135271.
In a case as illustrated in Figure 2 where the first electrode pattern 10 is formed
on the first main surface of the substrate 30 and where the second electrode pattern 40 is
formed on the second main surface of the substrate 30, if a standard manufacturing
method (in which the first main surface is first exposed to light, and the second main
30 surface is then exposed to light) is adopted, the first electrode pattern 10 and the second
electrode pattern 40 having desired patterns cannot be obtained in some cases.
34
In view of the above, the following manufacturing method can be preferably
adopted.
That is, photosensitive silver halide emulsion layers respectively formed on both
the surfaces of the substrate 30 are collectively exposed to light, whereby the first
5 electrode pattern 10 is formed on one main surface of the substrate 30 while the second
electrode pattern 40 is formed on another main surface of the substrate 30.
A specific example of the method of manufacturing the conductive sheet
according to aspects illustrated in Figures 1 to 33 is described.
First, an elongated photosensitive material is manufactured. The
10 photosensitive material includes: the substrate 30; a photosensitive silver halide emulsion
layer (hereinafter, referred to as first photosensitive layer) formed on the first main
surface of the substrate 30; and a photosensitive silver halide emulsion layer (hereinafter,
referred to as second photosensitive layer) formed on another main surface of the
substrate 30.
15 Subsequently, the photosensitive material is exposed to light. This exposure
process includes: a first exposure process performed on the first photosensitive layer, in
which the substrate 30 is irradiated with light so that and the first photosensitive layer is
exposed to the light along a first exposure pattern; and a second exposure process
performed on the second photosensitive layer, in which the substrate 30 is irradiated with
20 light so that the second photosensitive layer is exposed to the light along a second
exposure pattern (both-surfaces simultaneous exposure).
For example, in the state where the elongated photosensitive material is
transported in one direction, the first photosensitive layer is irradiated with first light
(parallel light) with the intermediation of a first photomask, while the second
25 photosensitive layer is irradiated with second light (parallel light) with the intermediation
of a second photomask. The first light is obtained by converting, into parallel light,
light emitted from a first light source by means of a halfway first collimator lens. The
second light is obtained by converting, into parallel light, light emitted from a second
light source by means of a halfway second collimator lens.
30 Although description is given above of the case where the two light sources (the
first light source and the second light source) are used, light emitted from one light
source may be split by an optical system into the first light and the second light, and the
35
first photosensitive layer and the second photosensitive layer may be irradiated with the
first light and the second light.
Subsequently, the photosensitive material after the exposure to light is
developed, whereby the conductive sheet 1 for the touch panel is manufactured. The
conductive sheet 1 for the touch panel includes: th 5 e substrate 30; the first electrode
pattern 10 that is formed along the first exposure pattern on the first main surface of the
substrate 30; and the second electrode pattern 40 that is formed along the second
exposure pattern on another main surface of the substrate 30. Note that the exposure
time and the development time of the first photosensitive layer and the second
10 photosensitive layer may variously change depending on the types of the first light
source and the second light source, the type of a developing solution, and the like.
Hence preferable numerical value ranges therefor cannot be unconditionally determined,
but the exposure time and the development time are adjusted such that the development
rate is 100%.
15 Then, according to the manufacturing method of the present embodiment, in the
first exposure process, the first photomask is, for example, closely placed on the first
photosensitive layer, and is irradiated with the first light emitted from the first light
source that is placed so as to be opposed to the first photomask, whereby the first
photosensitive layer is exposed to light. The first photomask includes a glass substrate
20 made of transparent soda glass and a mask pattern (first exposure pattern) formed on the
glass substrate. Accordingly, in the first exposure process, a portion of the first
photosensitive layer is exposed to light, the portion being along the first exposure pattern
formed on the first photomask. A gap of approximately 2 to 10 μm may be provided
between the first photosensitive layer and the first photomask.
25 Similarly, in the second exposure process, the second photomask is, for example,
closely placed on the second photosensitive layer, and is irradiated with the second light
emitted from the second light source that is placed so as to be opposed to the second
photomask, whereby the second photosensitive layer is exposed to light. Similarly to
the first photomask, the second photomask includes a glass substrate made of transparent
30 soda glass and a mask pattern (second exposure pattern) formed on the glass substrate.
Accordingly, in the second exposure process, a portion of the second photosensitive layer
is exposed to light, the portion being along the second exposure pattern formed on the
36
second photomask. In this case, a gap of approximately 2 to 10 μm may be provided
between the second photosensitive layer and the second photomask.
In the first exposure process and the second exposure process, the emission
timing of the first light from the first light source and the emission timing of the second
5 light from the second light source may be the same as each other, and may be different
from each other. If the emission timings thereof are the same as each other, the first
photosensitive layer and the second photosensitive layer can be simultaneously exposed
to light in one exposure process, and the processing time can be shortened. Meanwhile,
in the case where both the first photosensitive layer and the second photosensitive layer
10 are not spectrally sensitized, if the photosensitive material is exposed to light on both the
sides thereof, the exposure to light on one side influences image formation on the other
side (rear side).
That is, the first light from the first light source that has reached the first
photosensitive layer is scattered by silver halide grains contained in the first
15 photosensitive layer, and is transmitted as scattered light through the substrate 30, and
part of the scattered light reaches even the second photosensitive layer. Consequently,
a boundary portion between the second photosensitive layer and the substrate 30 is
exposed to light over a wide range, so that a latent image is formed. Hence, the second
photosensitive layer is exposed to both the second light from the second light source and
20 the first light from the first light source. In the case of manufacturing the conductive
sheet 1 for the touch panel in the subsequent development process, a thin conductive
layer substrated on the first light from the first light source is formed between the
conductive patterns in addition to the conductive pattern (second electrode pattern 40)
along the second exposure pattern, and a desired pattern (a pattern along the second
25 exposure pattern) cannot be obtained. The same applies to the first photosensitive layer.
As a result of intensive studies for avoiding this, the following is found out.
That is, if the thickness of each of the first photosensitive layer and the second
photosensitive layer is set within a particular range or if the amount of silver applied to
each of the first photosensitive layer and the second photosensitive layer is specified,
30 silver halide itself absorbs light, and this can restrict light transmission to the rear surface.
The thickness of each of the first photosensitive layer and the second photosensitive
layer can be set to 1 μm or more and 4 μm or less. The upper limit value thereof is
37
preferably 2.5 μm. Moreover, the amount of silver applied to each of the first
photosensitive layer and the second photosensitive layer is specified to 5 to 20 g/m2.
In the above-mentioned exposure method of both-surfaces close contact type, an
image defect due to a hindrance to exposure by dust and the like attached to the sheet
surface is problematic. 5 In order to prevent such dust attachment, it is known to apply a
conductive substance to the sheet, but metal oxides and the like remain even after the
process to impair the transparency of a final product, and conductive polymers have a
problem in preserving properties. As a result of intensive studies in view of the above,
it is found out that conductive properties necessary for prevention of static charge can be
10 obtained by silver halide with a reduced binder, and hence the volume ratio of
silver/binder of the first photosensitive layer and the second photosensitive layer is
specified. That is, the volume ratio of silver/binder of each of the first photosensitive
layer and the second photosensitive layer is 1/1 or more, and is preferably 2/1 or more.
If the thickness, the amount of applied silver, and the volume ratio of
15 silver/binder of each of the first photosensitive layer and the second photosensitive layer
are set and specified as described above, the first light from the first light source that has
reached the first photosensitive layer does not reach the second photosensitive layer.
Similarly, the second light from the second light source that has reached the second
photosensitive layer does not reach the first photosensitive layer. As a result, in the
20 case of manufacturing the conductive sheet 1 in the subsequent development process,
only the first electrode pattern 10 along the first exposure pattern is formed on the first
main surface of the substrate 30, and only the second electrode pattern 40 along the
second exposure pattern is formed on the second main surface of the substrate 30, so that
desired patterns can be obtained.
25 In this way, according to the above-mentioned manufacturing method using
both-surfaces collective exposure, the first photosensitive layer and the second
photosensitive layer having both conductive properties and suitability for the bothsurfaces
exposure can be obtained. Moreover, the same pattern or different patterns can
be arbitrarily formed on both the surfaces of the substrate 30 in one exposure process on
30 the substrate 30. This can facilitate formation of the electrodes of the touch panel, and
can achieve a reduction in thickness (a reduction in height) of the touch panel.
38
Next, focused description is given of a method of using a silver halide
photographic photosensitive material corresponding to a particularly preferable aspect,
for the conductive sheet 1 according to the present embodiment.
The method of manufacturing the conductive sheet 1 according to the present
5 embodiment includes the following three aspects depending on modes of the
photosensitive material and the development process.
(1) An aspect in which: a silver halide black-and-white photosensitive material
not including the center of physical development is chemically developed or thermally
developed; and a metal silver part is formed on the photosensitive material.
10 (2) An aspect in which: a silver halide black-and-white photosensitive material
including the center of physical development in a silver halide emulsion layer is
dissolved and physically developed; and a metal silver part is formed on the
photosensitive material.
(3) An aspect in which: a silver halide black-and-white photosensitive material
15 not including the center of physical development and an image receiving sheet having a
non-photosensitive layer including the center of physical development are put on top of
each other (overlaid) and then subjected to diffusion transfer development; and a metal
silver part is formed on the non-photosensitive image receiving sheet.
According to the aspect in (1), which is of integrated black-and-white
20 development type, a translucent conductive film such as a light-transmissive conductive
film is formed on the photosensitive material. The obtained developed silver is
chemically developed silver or thermally developed silver, and is highly active in the
subsequent plating or physical development process, because the obtained developed
silver is a filament having a high-specific surface.
25 According to the aspect in (2), in the exposed part, silver halide grains near the
center of physical development are dissolved and deposited on the center of development,
whereby a translucent conductive film such as a light-transmissive conductive film is
formed on the photosensitive material. This aspect is also of integrated black-and-white
development type. Because the development action is deposition on the center of
30 physical development, high activity is obtained, and the developed silver has a spherical
shape with a small-specific surface.
39
According to the aspect in (3), in the unexposed part, silver halide grains are
dissolved and diffused to be deposited on the center of development on the image
receiving sheet, whereby a translucent conductive film such as a light-transmissive
conductive film is formed on the image receiving sheet. This aspect is of so-called
separate 5 type, in which the image receiving sheet is separated for use from the
photosensitive material.
In any one of these aspects, both a negative development process and a reversal
development process can be selected (in the case of a diffusion transfer method, the use
of an auto-positive photosensitive material as the photosensitive material enables the
10 negative development process).
Here, a configuration of the conductive sheet 1 according to the present
embodiment is described below in detail.
[Substrate 30]
The substrate 30 can be formed using a plastic film, a plastic plate, a glass plate,
15 and the like. Examples of the raw materials of the plastic film and the plastic plate
include: polyesters such as polyethylene terephthalate (PET) and polyethylene
naphthalate (PEN); polyolefins such as polyethylene (PE), polypropylene (PP),
polystyrene, and ethylene vinyl acetate (EVA) / cycloolefin polymer (COP) / cycloolefin
copolymer (COC); vinyl resins; polycarbonate (PC); polyamide; polyimide; acrylic
20 resins; and triacetylcellulose (TAC). In particular, polyethylene terephthalate (PET) is
preferable from the perspective of the light transmissivity, the workability, and the like.
[Silver Salt Emulsion Layer]
A silver salt emulsion layer that becomes each of the first electrode pattern 10
and the second electrode pattern 40 of the first conductive sheet contains additives such
25 as a solvent and a colorant in addition to a silver salt and a binder.
Examples of the silver salt used in the present embodiment include inorganic
silver salts such as silver halide and organic silver salts such as silver acetate. In the
present embodiment, it is preferable to use silver halide excellent in characteristics as an
optical sensor.
30 The amount of silver (the amount of silver salt) applied to the silver salt
emulsion layer is preferably 1 to 30 g/m2, more preferably 1 to 25 g/m2, and further
preferably 5 to 20 g/m2, in terms of silver. If the amount of applied silver is set within
40
this range, a desired surface resistance can be obtained in the case of manufacturing the
conductive sheet 1 for the touch panel.
Examples of the binder used in the present embodiment include gelatin,
polyvinyl alcohol (PVA), polyvinylpyrrolidone (PVP), polysaccharides such as starch,
cellulose and derivatives thereof, polyethylene 5 oxide, polyvinylamine, chitosan,
polylysine, polyacrylic acid, polyalginic acid, polyhyaluronic acid, and carboxycellulose.
These substances each exhibit a neutral, anionic, or cationic property depending on the
ionicity of a functional group thereof.
The content of the binder in the silver salt emulsion layer is not particularly
10 limited, and can be determined as appropriate within a range in which the dispersibility
and the adhesiveness can be obtained. The content of the binder in the silver salt
emulsion layer is preferably 1/4 or more, and more preferably 1/2 or more, in terms of
the volume ratio of silver/binder. The volume ratio of silver/binder is preferably 100/1
or less, more preferably 50/1 or less, further preferably 10/1 or less, and particularly
15 preferably 6/1 or less. Moreover, the volume ratio of silver/binder is further preferably
1/1 to 4/1. The volume ratio of silver/binder is most preferably 1/1 to 3/1. If the
volume ratio of silver/binder in the silver salt emulsion layer is set within this range,
even in the case where the amount of applied silver is adjusted, fluctuations in resistance
value can be suppressed, and the conductive sheet for the touch panel having a uniform
20 surface resistance can be obtained. Note that the volume ratio of silver/binder can be
obtained by converting the amount of silver halide/the amount of binder (weight ratio) in
the raw material into the amount of silver/the amount of binder (weight ratio) and further
converting the amount of silver/the amount of binder (weight ratio) into the amount of
silver/the amount of binder (volume ratio).
25
The solvent used to form the silver salt emulsion layer is not particularly limited,
and examples thereof include water, organic solvents (for example, alcohols such as
methanol, ketones such as acetone, amides such as formamide, sulfoxides such as
dimethylsulfoxide, esters such as ethyl acetate, and ethers), ionic liquids, and a mixture
30 solvent of these solvents.
The content of the solvent used to form the silver salt emulsion layer of the
present embodiment falls within a range of 30 to 90 mass% of the total mass of the silver
41
salt, the binder, and the like contained in the silver salt emulsion layer, and preferably
falls within a range of 50 to 80 mass% thereof.

Various additives used in the present embodiment are not particularly limited,
5 and known additives can be preferably used therein.
[Other Layer Configurations]
A protective layer (not illustrated) may be provided on the silver salt emulsion
layer. The "protective layer" in the present embodiment means a layer made of a binder
such as gelatin and polymers, and is formed on the silver salt emulsion layer having
10 photosensitivity in order to produce effects of preventing scratches and improving
mechanical characteristics. The thickness of the protective layer is preferably 0.5 μm or
less. A method of applying and a method of forming the protective layer are not
particularly limited, and a known applying method and a known forming method can be
selected as appropriate. Moreover, for example, a basecoat layer may also be provided
15 under the silver salt emulsion layer.
Next, steps of the method of manufacturing the conductive sheet 1 are described.
[Exposure to Light]
The present embodiment includes the case where the first electrode pattern 10
and the second electrode pattern 40 are formed by printing. Besides the printing, the
20 first electrode pattern 10 and the second electrode pattern 40 are formed by exposure to
light, development, and the like. That is, a photosensitive material having a silver-saltcontaining
layer or a photosensitive material to which photopolymer for
photolithography has been applied, which is provided on the substrate 30, is exposed to
light. The exposure to light can be performed using electromagnetic waves. Examples
25 of the electromagnetic waves include light such as visible light rays and ultraviolet rays
and radiant rays such as X-rays. Further, a light source having wavelength distribution
may be used for the exposure to light, and a light source having a particular wavelength
may be used therefor.
A method using a glass mask and a pattern exposure method using laser drawing
30 are preferable for the exposure method.
[Development Process]
42
In the present embodiment, after the emulsion layer is exposed to light, the
development process is further performed. A technique of a standard development
process used for silver halide photographic films, printing paper, printing plate-making
films, photomask emulsion masks, and the like can be used for the development process.
5 The development process in the present embodiment can include a fixing
process performed for the purpose of stabilization by removing the silver salt in the
unexposed part. A technique of a fixing process used for silver halide photographic
films, printing paper, printing plate-making films, photomask emulsion masks, and the
like can be used for the fixing process in the present invention.
10 It is preferable that the photosensitive material that has been subjected to the
development and fixing process be subjected to a hardening process, a water washing
process, and a stabilization process.
The mass of metal silver contained in the exposed part after the development
process is preferably 50 mass% or more of the mass of silver contained in the exposed
15 part before the exposure to light, and is further preferable 80 mass% or more thereof. If
the mass of silver contained in the exposed part is 50 mass% or more of the mass of
silver contained in the exposed part before the exposure to light, high conductive
properties can be obtained, which is preferable.
The gradation after the development process in the present embodiment is not
20 particularly limited, and preferably exceeds 4.0. If the gradation after the development
process exceeds 4.0, the conductive properties of the conductive metal part can be
improved while the translucency of the light transmissive part is kept high. Examples
of means for making the gradation 4.0 or more include the doping with rhodium ions and
iridium ions described above.
25 The conductive sheet is obtained through the above-mentioned steps, and the
surface resistance of the obtained conductive sheet is preferably 100 Ω/sq. or less, more
preferably 80 Ω/sq. or less, further preferably 60 Ω/sq. or less, and further more
preferably 40 Ω/sq. or less. It is ideal to make the lower limit value of the surface
resistance as low as possible. In general, it is sufficient that the lower limit value
30 thereof be 0.01 Ω/sq. Even 0.1 Ω/sq. or 1 Ω/sq. can be adopted depending on the
purpose of use.
43
If the surface resistance is adjusted to such a range, position detection is possible
for even a large-size touch panel having an area of 10 cm × 10 cm or more. Moreover,
the conductive sheet after the development process may be further subjected to a
calendering process, and the surface resistance can be adjusted to a desired value by the
5 calendering process.
(Hardening Process after Development Process)
It is preferable to perform a hardening process on the silver salt emulsion layer
by immersing the same in a hardener after performing the development process thereon.
Examples of the hardener include: dialdehydes such as glutaraldehyde, adipaldehyde,
10 and 2,3-dihydroxy-1,4-dioxane; and inorganic compounds such as boric acid and chrome
alum/potassium alum, which are described in Japanese Patent Application Laid-Open No.
2-141279.
[Physical Development and Plating Process]
In the present embodiment, physical development and/or a plating process for
15 causing the metal silver part to support conductive metal grains may be performed for the
purpose of enhancing the conductive properties of the metal silver part formed by the
exposure to light and the development process. In the present invention, the metal
silver part may be caused to support conductive metal grains through only any one of the
physical development and the plating process, and the metal silver part may be caused to
20 support conductive metal grains through a combination of the physical development and
the plating process. Note that the metal silver part that has been physically developed
and/or plated is also referred to as "conductive metal part".
[Oxidation Process]
In the present embodiment, it is preferable that the metal silver part after the
25 development process and the conductive metal part formed by the physical development
and/or the plating process be subjected to an oxidation process. For example, in the
case where a slight amount of metal is deposited in the light transmissive part, the
oxidation process can remove the metal, and can make the transmissivity of the light
transmissive part substantially 100%.
30 [Light Transmissive Part]
The "light transmissive part" in the present embodiment means a translucent
portion other than the first electrode pattern 10 and the second electrode pattern 40, of
44
the conductive sheet 1. As described above, the transmittance of the light transmissive
part is 90% or more, preferably 95% or more, further preferably 97% or more, further
more preferably 98% or more, and most preferably 99% or more, in terms of the
transmittance indicated by the minimum value of the transmittance in a wavelength
5 region of 380 to 780 nm excluding contributions to light absorption and reflection of the
substrate 30.
[Conductive Sheet 1]
The film thickness of the substrate 30 in the conductive sheet 1 according to the
present embodiment is preferably 5 to 350 μm and further preferably 30 to 150 μm. If
10 the film thickness thereof is set within such a range of 5 to 350 μm, a desired
transmittance of visible light can be obtained, and handling is easy.
The thickness of the metal silver part provided on the substrate 30 can be
determined as appropriate in accordance with the application thickness of coating for the
silver-salt-containing layer applied onto the substrate 30. The thickness of the metal
15 silver part can be selected from 0.001 mm to 0.2 mm, and is preferably 30 μm or less,
more preferably 20 μm or less, further preferably 0.01 to 9 μm, and most preferably 0.05
to 5 μm. Moreover, it is preferable that the metal silver part be patterned. The metal
silver part may have a single-layered structure, and may have a multi-layered structure of
two or more layers. In the case where the metal silver part is patterned and has a multi20
layered structure of two or more layers, the metal silver part can be provided with
different color sensitivities so as to be reactive to different wavelengths. As a result, if
the metal silver part is exposed to light with different wavelengths, different patterns can
be formed in the respective layers.
For use in a touch panel, a smaller thickness of the conductive metal part is
25 more preferable, because the viewing angle of a display panel is wider. Also in terms
of enhancement in visibility, a reduction in thickness of the conductive metal part is
required. From such perspectives, it is desirable that the thickness of the layer made of
the conductive metal supported by the conductive metal part be less than 9 μm, less than
5 μm, or less than 3 μm, and be 0.1 μm or more.
30 In the present embodiment, the metal silver part having a desired thickness can
be formed by controlling the application thickness of the silver-salt-containing layer, and
the thickness of the layer made of the conductive metal grains can be freely controlled by
45
the physical development and/or the plating process. Hence, even the conductive sheet
1 having a thickness that is less than 5 μm and preferably less than 3 μm can be easily
formed.
Note that the method of manufacturing the conductive sheet according to the
present embodiment does not ne 5 cessarily need to include the plating step and the like.
This is because the method of manufacturing the conductive sheet 1 according to the
present embodiment can obtain a desired surface resistance by adjusting the amount of
applied silver and the volume ratio of silver/binder of the silver salt emulsion layer.
With regard to the above-mentioned manufacturing method, description is given
10 of the conductive sheet 1 including: the substrate 30; the first electrode pattern 10 formed
on the first main surface of the substrate 30; and the second electrode pattern 40 formed
on the second main surface of the substrate 30, which are illustrated in Figure 2.
Alternatively, as illustrated in Figure 33, the conductive sheet 1 which includes the
substrate 30 and the first electrode pattern 10 formed on the first main surface of the
15 substrate 30, and a conductive sheet 2 which includes a substrate 80 and the second
electrode pattern 40 formed on a first main surface of the substrate 80 may be placed on
top of each other (overlaid) such that the first electrode pattern 10 and the second
electrode pattern 40 are orthogonal to each other. The manufacturing method applied to
the substrate 30 and the first electrode pattern can be adopted for the substrate 80 and the
20 second electrode pattern 40.
The conductive sheet and the touch panel according to the present invention are
not limited to the above-mentioned embodiments, and can have various configurations
without departing from the gist of the present invention, as a matter of course.
Moreover, the conductive sheet and the touch panel according to the present invention
25 can be used in appropriate combination with techniques disclosed in, for example,
Japanese Patent Application Laid-Open No. 2011-113149, No. 2011-129501, No. 2011-
129112, No. 2011-134311, and No. 2011-175628.
Hereinafter, a conductive sheet and a capacitive touch panel according to
another embodiment are described with reference to Figure 34 to Figure 40. Note that,
30 herein, "to" indicating a numerical value range is used to mean that the numerical value
range includes numerical values given before and after "to" as its lower limit value and
its upper limit value.
46
As illustrated in Figure 34 and Figure 35A, a conductive sheet for a touch panel
(hereinafter, referred to as the conductive sheet 210 for the touch panel) according to the
present embodiment is formed by laminating a first conductive sheet 212A and a second
conductive sheet 212B.
5 As illustrated in Figure 34 and Figure 36, the first conductive sheet 212A
includes a first electrode pattern 216A formed on one main surface of a first transparent
substrate 214A (see Figure 35A). The first electrode pattern 216A is formed by a large
number of grids made of metal thin wires. The first electrode pattern 216A includes:
two or more first conductive patterns 218A that extend in a first direction (x direction)
10 and are arranged in a second direction (y direction) orthogonal to the first direction; and
first nonconductive patterns 220A that electrically separate the first conductive patterns
218A from each other. Each first nonconductive pattern 220A includes a plurality of
break parts 222A (referred to as first break parts 222A as needed) formed in portions
other than intersection points of the metal thin wires. The first conductive patterns
15 218A are electrically separated from each other by the plurality of break parts 222A.
The metal thin wires that form the first electrode pattern 216A each have a wire
width of 0.5 μm to 30 μm. It is desirable that the wire width of each metal thin wire be
30 μm or less, preferably 15 μm or less, more preferably 10 μm or less, more preferably
9 μm or less, and more preferably 7 μm or less, and be preferably 0.5 μm or more. Note
20 that, although the first conductive patterns 218A and the first nonconductive patterns
220A have substantially the same wire width, in Figure 36, in order to clarify the first
conductive patterns 218A and the first nonconductive patterns 220A, the wire width of
each first conductive pattern 218A is exaggeratingly thickened, and the wire width of
each first nonconductive pattern 220A is exaggeratingly thinned. The wire width of
25 each first conductive pattern 218A and the wire width of each first nonconductive pattern
220A may be the same as each other, and may be different from each other. Preferably,
the wire widths of the two are the same as each other. The reason for this is that the
visibility may become lower if the wire widths of the two are different from each other.
The metal thin wires of the first electrode pattern 216A are made of metal materials such
30 as gold, silver, and copper and conductive materials such as metal oxides.
The first electrode pattern 216A includes a plurality of grids 224A made of
metal thin wires that intersect with each other. The grids 224A each include an opening
47
region surrounded by the metal thin wires. The grids 224A have a grid pitch Pa of 250
μm to 900 μm, and preferably have a grid pitch Pa of 300 μm to 700 μm. The grids
224A of the first conductive patterns 218A and the grids 224A of the first nonconductive
patterns 220A have substantially the same size.
5 The grids 224A of the first nonconductive patterns 220A include the break parts
222A in portions other than the intersection parts of the metal thin wires. All the grids
224A that form the first nonconductive patterns 220A do not necessarily need to include
the break parts 222A. It is sufficient that the first nonconductive patterns 220A can
achieve electrical separation between adjacent ones of the first conductive patterns 218A.
10 The length of each break part 222A is preferably 60 μm or less, and is more preferably
10 to 50 μm, 15 to 40 μm, and 20 to 40 μm. Moreover, the formation range of the break
parts 222A can be expressed by, for example, a fluctuation in wire density. Here, the
fluctuation in wire density refers to a fluctuation in total thin wire length of unit small
grids, and can be defined as ±(the maximum value of total wire length - the minimum
15 value of total wire length) / the average value of total wire length / 2 (%). The
formation range of the break parts 222A is preferably ±15%, more preferably ±10%, and
further preferably ±0.5% to ±5%, in terms of the fluctuation in wire density.
In the conductive sheet 210 for the touch panel, each grid 224A has a
substantially rhomboid shape. Here, the substantially rhomboid shape means a
20 parallelogram whose diagonals are substantially orthogonal to each other. Alternatively,
each grid 224A may have other polygonal shapes. Moreover, the shape of one side of
each grid 224A may be a curved shape or a circular arc shape instead of a straight shape.
In the case of the circular arc shape, for example, opposing two of the sides of each grid
224A may each have a circular arc shape convex outward, and other opposing two of the
25 sides thereof may each have a circular arc shape convex inward. Moreover, the shape
of each side of each grid 224A may be a wavy shape in which a circular arc convex
outward and a circular arc convex inward are alternately continuous. As a matter of
course, the shape of each side thereof may be a sine curve.
Each first conductive pattern 218A includes wider portions and narrower
30 portions that are alternately placed along the first direction (x direction). Similarly,
each first nonconductive pattern 220A includes wider portions and narrower portions that
are alternately placed along the first direction (x direction). The order of the wider
48
portions and the narrower portions of each first conductive pattern 218A is opposite to
the order of the wider portions and the narrower portions of each first nonconductive
pattern 220A.
Each first conductive pattern 218A has one end electrically connected to a first
external wire 262A via a first term 5 inal 260A. Meanwhile, each first conductive pattern
218A has another end that is an opened end.
As illustrated in Figure 34 and Figure 37, the second conductive sheet 212B
includes a second electrode pattern 216B formed on one main surface of a second
transparent substrate 214B (see Figure 35A). The second electrode pattern 216B is
10 formed by a large number of grids made of metal thin wires. The second electrode
pattern 216B includes: two or more second conductive patterns 218B that extend in the
second direction (y direction) and are arranged in the first direction (x direction)
orthogonal to the second direction; and second nonconductive patterns 220B that
electrically separate the second conductive patterns 218B from each other. Each second
15 nonconductive pattern 220B includes a plurality of break parts 222B (referred to as
second break parts 222B as needed) formed in portions other than intersection points of
the metal thin wires. The second conductive patterns 218B are electrically separated
from each other by the plurality of break parts 222B.
The metal thin wires that form the second electrode pattern 216B each have a
20 wire width of 0.5 μm to 30 μm. It is desirable that the wire width of each metal thin
wire be 30 μm or less, preferably 15 μm or less, more preferably 10 μm or less, more
preferably 9 μm or less, and more preferably 7 μm or less, and be preferably 0.5 μm or
more. Note that, although the second conductive patterns 218B and the second
nonconductive patterns 220B have substantially the same wire width, in Figure 37, in
25 order to clarify the second conductive patterns 218B and the second nonconductive
patterns 220B, the wire width of each second conductive pattern 218B is exaggeratingly
thickened, and the wire width of each second nonconductive pattern 220B is
exaggeratingly thinned. The wire width of each second conductive pattern 218B and
the wire width of each second nonconductive pattern 220B may be the same as each
30 other, and may be different from each other. Preferably, the wire widths of the two are
the same as each other. The reason for this is that the visibility may become lower if
the wire widths of the two are different from each other. The metal thin wires of the
49
first electrode pattern 216A are made of metal materials such as gold, silver, and copper
and conductive materials such as metal oxides.
The second electrode pattern 216B includes a plurality of grids 224B made of
metal thin wires that intersect with each other. The grids 224B each include an opening
region surrounded by the metal 5 thin wires. The grids 224B have a grid pitch Pb of 250
μm to 900 μm, and preferably have a grid pitch Pb of 300 μm to 700 μm. The grids
224B of the second conductive patterns 218B and the grids 224B of the second
nonconductive patterns 220B have substantially the same size.
The grids 224B of the second nonconductive patterns 220B include the break
10 parts 222B in portions other than the intersection parts of the metal thin wires. All the
grids 224B that form the second nonconductive patterns 220B do not necessarily need to
include the break parts 222B. It is sufficient that the second nonconductive patterns
220B can achieve electrical separation between adjacent ones of the second conductive
patterns 218B. The length of each break part 222B is preferably 60 μm or less, and is
15 more preferably 10 to 50 μm, 15 to 40 μm, and 20 to 40 μm. Moreover, the formation
range of the break parts 22B can be expressed by, for example, a fluctuation in wire
density. Here, the fluctuation in wire density refers to a fluctuation in total thin wire
length of unit small grids, and can be defined as ±(the maximum value of total wire
length - the minimum value of total wire length) / the average value of total wire length /
20 2 (%). The formation range of the break parts 222B is preferably ±15%, more
preferably ±10%, and further preferably ±0.5% to ±5%, in terms of the fluctuation in
wire density.
In the conductive sheet 210 for the touch panel, each grid 224B has a
substantially rhomboid shape. Here, the substantially rhomboid shape means a
25 parallelogram whose diagonals are substantially orthogonal to each other. Alternatively,
each grid 224B may have other polygonal shapes. Moreover, the shape of one side of
each grid 224B may be a curved shape or a circular arc shape instead of a straight shape.
In the case of the circular arc shape, for example, opposing two of the sides of each grid
224B may each have a circular arc shape convex outward, and other opposing two of the
30 sides thereof may each have a circular arc shape convex inward. Moreover, the shape
of each side of each grid 224B may be a wavy shape in which a circular arc convex
50
outward and a circular arc convex inward are alternately continuous. As a matter of
course, the shape of each side thereof may be a sine curve.
Each second conductive pattern 218B includes wider portions and narrower
portions that are alternately placed along the second direction (y direction). Similarly,
5 each second nonconductive pattern 220B includes wider portions and narrower portions
that are alternately placed along the second direction (y direction). The order of the
wider portions and the narrower portions of each second conductive pattern 218B is
opposite to the order of the wider portions and the narrower portions of each second
nonconductive pattern 220B.
10 Each second conductive pattern 218B has one end electrically connected to a
second external wire 262B via a second terminal 260B. Meanwhile, each second
conductive pattern 218B has another end that is an opened end.
Then, when the conductive sheet 210 for the touch panel is formed by
laminating, for example, the first conductive sheet 212A on the second conductive sheet
15 212B, the first electrode pattern 216A and the second electrode pattern 216B are placed
so as not to overlap with each other as illustrated in Figure 38. At this time, the first
electrode pattern 216A and the second electrode pattern 216B are placed such that the
narrower portions of the first conductive patterns 218A are opposed to the narrower
portions of the second conductive patterns 218B and that the narrower portions of the
20 first conductive patterns 218A intersect with the second conductive patterns 218B. As a
result, the first electrode pattern 216A and the second electrode pattern 216B form a
combination pattern 270. Note that the wire widths of the first electrode pattern 216A
and the second electrode pattern 216B are substantially the same as each other.
Moreover, the sizes of the grids 224A and the grids 224B are substantially the same as
25 each other. However, in Figure 38, in order to clarify a positional relation of the first
electrode pattern 216A and the second electrode pattern 216B, the wire width of the first
electrode pattern 216A is made thicker than the wire width of the second electrode
pattern 216B.
In the combination pattern 270, the grids 224A and the grids 224B form small
30 grids 276 in top view. That is, the intersection parts of the grids 224A are respectively
placed in the opening regions of the grids 224B. Note that the small grids 276 have a
51
grid pitch Ps of 125 μm to 450 μm that is half the respective grid pitches Pa and Pb of the
grids 224A and the grids 224B, and preferably have a grid pitch Ps of 150 μm to 350 μm.
The break parts 222A of the first nonconductive patterns 220A are formed in
portions other than the intersection parts of the grids 224A, and the break parts 222B of
5 the second nonconductive patterns 220B are formed in portions other than the
intersection parts of the grids 224B. As a result, a decrease in visibility caused by the
break parts 222A and the break parts 222B can be prevented in the combination pattern
270.
In particular, the metal thin wires of the second conductive patterns 218B are
10 placed at positions opposed to the break parts 222A. Moreover, the metal thin wires of
the first conductive patterns 218A are placed at positions opposed to the break parts
222B. The metal thin wires of the second conductive patterns 218B mask the break
parts 222A, and the metal thin wires of the first conductive patterns 218A mask the break
parts 222B. Accordingly, in the combination pattern 270, the break parts 222A and the
15 break parts 222B are less easily visually observed in top view, and hence the visibility
can be enhanced. In consideration of enhancement in visibility, it is preferable that the
length of each break part 222A and the wire width of each of the metal thin wires of the
second conductive patterns 218B satisfy a relational expression of the wire width × 1 <
the break part < the wire width × 10. Similarly, it is preferable that the length of each
20 break part 222B and the wire width of each of the metal thin wires of the first conductive
patterns 218A satisfy a relational expression of the wire width × 1 < the break part < the
wire width × 10.
Next, a relation between the second break parts 222B and the metal thin wires of
the first conductive patterns 218A and a relation between the first break parts 222A and
25 the metal thin wires of the second conductive patterns 218B are described. Figure 39 is
a schematic view illustrating a positional relation between the metal thin wire and the
break part. Assuming that the width of each of the metal thin wires of the first
conductive patterns 218A and the metal thin wires of the second conductive patterns
218B is a and that the width of each of the first break parts 222A of the first
30 nonconductive patterns 220A and the second break parts 222B of the second
nonconductive patterns 220B is b, it is preferable that a relational expression of b - a ≤ 30
μm be satisfied. This means that, as a difference between the width of each metal thin
52
wire and the width of each break part is smaller, a portion of the break part occupied by
the metal thin wire is larger, and a decrease in visibility can be more prevented.
Moreover, assuming that the width of each of the metal thin wires of the first
conductive patterns 218A and the metal thin wires of the second conductive patterns
5 218B is a and that the width of each of the first break parts 222A of the first
nonconductive patterns 220A and the second break parts 222B of the second
nonconductive patterns 220B is b, it is preferable that a relational expression of (b - a) / a
≤ 6 be satisfied. This means that the width of each of the second break parts 222B of
the second nonconductive patterns 220B is equal to or less than a predetermined width,
10 with respect to the width of each of the metal thin wires of the first conductive patterns
218A and the metal thin wires of the second conductive patterns 218B. Similarly to the
above, this means that a portion of each break part occupied by each metal thin wire is as
large as possible, and a decrease in visibility can be more prevented.
Next, a positional misalignment between the central position of each metal thin
15 wire and the central position of each break part is described. Figure 40 is a schematic
view illustrating a relation between the central position of the metal thin wire and the
central position of the break part. A central line CL1 designates the central position of
each of the metal thin wires of the first conductive patterns 218A and the metal thin
wires of the second conductive patterns 218B. A central line CL2 designates the central
20 position of each of the second break parts 222B and the first break parts 222A. An
amount of misalignment d means a distance between the central line CL1 and the central
line CL2. Assuming that each amount of misalignment is d and that the average value
of the amounts of misalignment d is dAve., it is preferable that a standard deviation σ be
10 μm or less. A small standard deviation σ means that fluctuations in the amount of
25 misalignment d between the central line CL1 and the central line CL2 are small. In the
case where each metal thin wire is located as closer to the center of each break part as
possible, distances L1 and L2 that are gaps between the metal thin wires of the first
conductive patterns 218A and the metal thin wires of the second nonconductive patterns
220B are more equal to each other, or distances L1 and L2 that are gaps between the
30 metal thin wires of the second conductive patterns 218B and the metal thin wires of the
first nonconductive patterns 220A are more equal to each other. Such symmetry makes
53
the patterns less perceivable in terms of human visibility, with the result that a decrease
in visibility can be prevented.
In the case where the conductive sheet 210 for the touch panel is used for a
touch panel, a protective layer (not illustrated) is formed on the first conductive sheet
5 212A. The first external wires 62A respectively drawn from the large number of first
conductive patterns 218A of the first conductive sheet 212A and the second external
wires 262B respectively drawn from the large number of second conductive patterns
218B of the second conductive sheet 212B are connected to, for example, an IC circuit
that controls scanning.
10 In order to minimize the area of a peripheral region outside of a display screen
of a liquid crystal display device, of the conductive sheet 210 for the touch panel,
preferably, the respective connection parts between the first conductive patterns 218A
and the first external wires 262A are linearly arranged, and the respective connection
parts between the second conductive patterns 218B and the second external wires 262B
15 are linearly arranged.
If the tip of a finger is brought into contact with the protective layer, an
electrostatic capacitance between the first conductive patterns 218A and the second
conductive patterns 218B opposed to the tip of the finger changes. The IC circuit
detects the amount of this change, and calculates the position of the tip of the finger on
20 the basis of the amount of this change. Such calculation is performed on between each
first conductive pattern 218A and each second conductive pattern 218B. Accordingly,
even if the tips of two or more fingers are brought into contact at the same time, the
position of the tip of each finger can be detected.
In this way, in the case where the conductive sheet 210 for the touch panel is
25 applied to, for example, a projected capacitive touch panel, the conductive sheet 210 for
the touch panel can increase a response speed because of its small surface resistance, and
can promote an increase in size of the touch panel.
Next, a method of manufacturing the first conductive sheet 212A and the second
conductive sheet 212B is described.
30 In the case of manufacturing the first conductive sheet 212A and the second
conductive sheet 212B, for example, a photosensitive material having an emulsion layer
containing photosensitive silver halide is exposed to light and developed on each of the
54
first transparent substrate 214A and the second transparent substrate 214B, and a metal
silver part (metal thin wires) and a light transmissive part (opening regions) are
respectively formed in the exposed part and the unexposed part, whereby the first
electrode pattern 216A and the second electrode pattern 216B may be formed. Note
that the metal silver part is further physically de 5 veloped and/or plated, whereby the metal
silver part may be caused to support conductive metal.
Alternatively, a resist pattern is formed by exposing to light and developing a
photoresist film on copper foil formed on each of the first transparent substrate 214A and
the second transparent substrate 214B, and the copper foil exposed on the resist pattern is
10 etched, whereby the first electrode pattern 216A and the second electrode pattern 216B
may be formed.
Alternatively, a paste containing metal fine grains is printed on each of the first
transparent substrate 214A and the second transparent substrate 214B, and the paste is
plated with metal, whereby the first electrode pattern 216A and the second electrode
15 pattern 216B may be formed.
The first electrode pattern 216A and the second electrode pattern 216B may be
respectively formed by printing on the first transparent substrate 214A and the second
transparent substrate 214B, using a screen printing plate or a gravure printing plate.
Alternatively, the first electrode pattern 216A and the second electrode pattern 216B may
20 be respectively formed on the first transparent substrate 214A and the second transparent
substrate 214B, according to an inkjet process.
In a case as illustrated in Figure 35B where the first electrode pattern 216A is
formed on one main surface of the first transparent substrate 214A and where the second
electrode pattern 216B is formed on another main surface of the first transparent
25 substrate 214A, if a standard manufacturing method (in which the one main surface is
first exposed to light, and the another main surface is then exposed to light) is adopted,
the first electrode pattern 216A and the second electrode pattern 216B having desired
patterns cannot be obtained in some cases.
In view of the above, the following manufacturing method can be preferably
30 adopted.
That is, photosensitive silver halide emulsion layers respectively formed on both
the surfaces of the first transparent substrate 214A are collectively exposed to light,
55
whereby the first electrode pattern 216A is formed on the one main surface of the first
transparent substrate 214A while the second electrode pattern 216B is formed on the
another main surface of the first transparent substrate 214A.
A specific example of the method of manufacturing the conductive sheet
5 according to aspects illustrated in Figures 34 to 40 is described.
First, an elongated photosensitive material is manufactured. The
photosensitive material includes: the first transparent substrate 214A; a photosensitive
silver halide emulsion layer (hereinafter, referred to as first photosensitive layer) formed
on the one main surface of the first transparent substrate 214A; and a photosensitive
10 silver halide emulsion layer (hereinafter, referred to as second photosensitive layer)
formed on the another main surface of the first transparent substrate 214A.
Subsequently, the photosensitive material is exposed to light. This exposure
process includes: a first exposure process performed on the first photosensitive layer, in
which the first transparent substrate 214A is irradiated with light so that the first
15 photosensitive layer is exposed to the light along a first exposure pattern; and a second
exposure process performed on the second photosensitive layer, in which the first
transparent substrate 214A is irradiated with light so that the second photosensitive layer
is exposed to the light along a second exposure pattern (both-surfaces simultaneous
exposure).
20 For example, in the state where the elongated photosensitive material is
transported in one direction, the first photosensitive layer is irradiated with first light
(parallel light) with the intermediation of a first photomask, while the second
photosensitive layer is irradiated with second light (parallel light) with the intermediation
of a second photomask. The first light is obtained by converting, into parallel light,
25 light emitted from a first light source by means of a halfway first collimator lens. The
second light is obtained by converting, into parallel light, light emitted from a second
light source by means of a halfway second collimator lens.
Although description is given above of the case where the two light sources (the
first light source and the second light source) are used, light emitted from one light
30 source may be split by an optical system into the first light and the second light, and the
first photosensitive layer and the second photosensitive layer may be irradiated with the
first light and the second light.
56
Subsequently, the photosensitive material after the exposure to light is
developed, whereby, for example, the conductive sheet 210 for the touch panel as
illustrated in Figure 35B is made. The conductive sheet 210 for the touch panel
includes: the first transparent substrate 214A; the first electrode pattern 216A that is
formed along the f 5 irst exposure pattern on the one main surface of the first transparent
substrate 214A; and the second electrode pattern 216B that is formed along the second
exposure pattern on the another main surface of the first transparent substrate 214A.
Note that the exposure time and the development time of the first photosensitive layer
and the second photosensitive layer may variously change depending on the types of the
10 first light source and the second light source, the type of a developing solution, and the
like. Hence preferable numerical value ranges therefor cannot be unconditionally
determined, but the exposure time and the development time are adjusted such that the
development rate is 100%.
Then, according to the manufacturing method of the present embodiment, in the
15 first exposure process, the first photomask is, for example, closely placed on the first
photosensitive layer, and is irradiated with the first light emitted from the first light
source that is placed so as to be opposed to the first photomask, whereby the first
photosensitive layer is exposed to light. The first photomask includes a glass substrate
made of transparent soda glass and a mask pattern (first exposure pattern) formed on the
20 glass substrate. Accordingly, in the first exposure process, a portion of the first
photosensitive layer is exposed to light, the portion being along the first exposure pattern
formed on the first photomask. A gap of approximately 2 to 10 μm may be provided
between the first photosensitive layer and the first photomask.
Similarly, in the second exposure process, the second photomask is, for example,
25 closely placed on the second photosensitive layer, and is irradiated with the second light
emitted from the second light source that is placed so as to be opposed to the second
photomask, whereby the second photosensitive layer is exposed to light. Similarly to
the first photomask, the second photomask includes a glass substrate made of transparent
soda glass and a mask pattern (second exposure pattern) formed on the glass substrate.
30 Accordingly, in the second exposure process, a portion of the second photosensitive layer
is exposed to light, the portion being along the second exposure pattern formed on the
57
second photomask. In this case, a gap of approximately 2 to 10 μm may be provided
between the second photosensitive layer and the second photomask.
In the first exposure process and the second exposure process, the emission
timing of the first light from the first light source and the emission timing of the second
5 light from the second light source may be the same as each other, and may be different
from each other. If the emission timings thereof are the same as each other, the first
photosensitive layer and the second photosensitive layer can be simultaneously exposed
to light in one exposure process, and the processing time can be shortened. Meanwhile,
in the case where both the first photosensitive layer and the second photosensitive layer
10 are not spectrally sensitized, if the photosensitive material is exposed to light on both the
sides thereof, the exposure to light on one side influences image formation on the other
side (rear side).
That is, the first light from the first light source that has reached the first
photosensitive layer is scattered by silver halide grains contained in the first
15 photosensitive layer, and is transmitted as scattered light through the first transparent
substrate 214A, and part of the scattered light reaches even the second photosensitive
layer. Consequently, a boundary portion between the second photosensitive layer and
the first transparent substrate 214A is exposed to the light over a wide range, so that a
latent image is formed. Hence, the second photosensitive layer is exposed to both the
20 second light from the second light source and the first light from the first light source.
In the case of manufacturing the conductive sheet 210 for the touch panel in the
subsequent development process, a thin conductive layer based on the first light from the
first light source is formed between the conductive patterns in addition to the conductive
pattern (second electrode pattern 216B) along the second exposure pattern, and a desired
25 pattern (a pattern along the second exposure pattern) cannot be obtained. The same
applies to the first photosensitive layer.
As a result of intensive studies for avoiding this, the present inventors find out
the following point. That is, if the thickness of each of the first photosensitive layer and
the second photosensitive layer is set within a particular range or if the amount of silver
30 applied to each of the first photosensitive layer and the second photosensitive layer is
specified, silver halide itself absorbs light, and this can restrict light transmission to the
rear surface. In the present embodiment, the thickness of each of the first
58
photosensitive layer and the second photosensitive layer can be set to 1 μm or more and
4 μm or less. The upper limit value thereof is preferably 2.5 μm. Moreover, the
amount of silver applied to each of the first photosensitive layer and the second
photosensitive layer is specified to 5 to 20 g/m2.
5 In the above-mentioned exposure method of both-surfaces close contact type, an
image defect due to a hindrance to exposure by dust and the like attached to the sheet
surface is problematic. In order to prevent such dust attachment, it is known to apply a
conductive substance to the sheet, but metal oxides and the like remain even after the
process to impair the transparency of a final product, and conductive polymers have a
10 problem in preserving properties. As a result of intensive studies in view of the above,
the present inventors find out that conductive properties necessary for prevention of
static charge can be obtained by silver halide with a reduced binder, and thus specify the
volume ratio of silver/binder of each of the first photosensitive layer and the second
photosensitive layer. That is, the volume ratio of silver/binder of each of the first
15 photosensitive layer and the second photosensitive layer is 1/1 or more, and is preferably
2/1 or more.
If the thickness, the amount of applied silver, and the volume ratio of
silver/binder of each of the first photosensitive layer and the second photosensitive layer
are set and specified as described above, the first light from the first light source that has
20 reached the first photosensitive layer does not reach the second photosensitive layer.
Similarly, the second light from the second light source that has reached the second
photosensitive layer does not reach the first photosensitive layer. As a result, in the
case of manufacturing the conductive sheet 210 for the touch panel in the subsequent
development process, as illustrated in Figure 35B, only the first electrode pattern 216A
25 along the first exposure pattern is formed on the one main surface of the first transparent
substrate 214A, and only the second electrode pattern 216B along the second exposure
pattern is formed on the another surface of the first transparent substrate 214A, so that
desired patterns can be obtained.
In this way, according to the above-mentioned manufacturing method using
30 both-surfaces collective exposure, the first photosensitive layer and the second
photosensitive layer having both conductive properties and suitability for the bothsurfaces
exposure can be obtained. Moreover, the same pattern or different patterns can
59
be arbitrarily formed on both the surfaces of the first transparent substrate 214A in one
exposure process on the first transparent substrate 214A. This can facilitate formation
of the electrodes of the touch panel, and can achieve a reduction in thickness (a reduction
in height) of the touch panel.
5 Next, focused description is given of a method of using a silver halide
photographic photosensitive material corresponding to a particularly preferable aspect,
for the first conductive sheet 212A and the second conductive sheet 212B according to
the present embodiment.
The method of manufacturing the first conductive sheet 212A and the second
10 conductive sheet 212B according to the present embodiment includes the following three
aspects depending on modes of the photosensitive material and the development process.
(1) An aspect in which: a silver halide black-and-white photosensitive material
not including the center of physical development is chemically developed or thermally
developed; and a metal silver part is formed on the photosensitive material.
15 (2) An aspect in which: a silver halide black-and-white photosensitive material
including the center of physical development in a silver halide emulsion layer is
dissolved and physically developed; and a metal silver part is formed on the
photosensitive material.
(3) An aspect in which: a silver halide black-and-white photosensitive material
20 not including the center of physical development and an image receiving sheet having a
non-photosensitive layer including the center of physical development are put on top of
each other (overlaid) and then subjected to diffusion transfer development; and a metal
silver part is formed on the non-photosensitive image receiving sheet.
According to the aspect in (1), which is of integrated black-and-white
25 development type, a translucent conductive film such as a light-transmissive conductive
film is formed on the photosensitive material. The obtained developed silver is
chemically developed silver or thermally developed silver, and is highly active in the
subsequent plating or physical development process, because the obtained developed
silver is a filament having a high-specific surface.
30 According to the aspect in (2), in the exposed part, silver halide grains near the
center of physical development are dissolved and deposited on the center of development,
whereby a translucent conductive film such as a light-transmissive conductive film is
60
formed on the photosensitive material. This aspect is also of integrated black-and-white
development type. Because the development action is deposition on the center of
physical development, high activity is obtained, and the developed silver has a spherical
shape with a small-specific surface.
5 According to the aspect in (3), in the unexposed part, silver halide grains are
dissolved and diffused to be deposited on the center of development on the image
receiving sheet, whereby a translucent conductive film such as a light-transmissive
conductive film is formed on the image receiving sheet. This aspect is of so-called
separate type, in which the image receiving sheet is separated for use from the
10 photosensitive material.
In any one of these aspects, both a negative development process and a reversal
development process can be selected (in the case of a diffusion transfer method, the use
of an auto-positive photosensitive material as the photosensitive material enables the
negative development process).
15 The chemical development, the thermal development, the dissolution and
physical development, and the diffusion transfer development described above have the
same meanings as those of the respective terms normally used in this technical field, and
are explained in general textbooks about photographic chemistry, for example, "Shashin
Kagaku (Photographic Chemistry)" written by Shinichi Kikuchi (published by Kyoritsu
20 Shuppan Co., Ltd. in 1955) and "The Theory of Photographic Processes, 4th ed." edited
by C. E. K. Mees (published by Mcmillan Publishers Ltd in 1977). Although
description is given above of an invention relating to liquid processes, but techniques
adopting thermal development methods can also be referred to as other development
methods. For example, it is possible to apply techniques described in Japanese Patent
25 Application Laid-Open No. 2004-184693, No. 2004-334077, and No. 2005-010752 and
Japanese Patent Application No. 2004-244080 and No. 2004-085655.
Here, layer configurations of the first conductive sheet 212A and the second
conductive sheet 212B according to the present embodiment are described below in
detail.
30 [First Transparent Substrate 214A and Second Transparent Substrate 214B]
The first transparent substrate 214A and the second transparent substrate 214B
can be each formed using a plastic film, a plastic plate, a glass plate, and the like.
61
Examples of the raw materials of the plastic film and the plastic plate include:
polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN);
polyolefins such as polyethylene (PE), polypropylene (PP), polystyrene, and ethylene
vinyl acetate (EVA) / cycloolefin polymer (COP) / cycloolefin copolymer (COC); vinyl
resins; polycarbonate (PC); polyamide; 5 polyimide; acrylic resins; and triacetylcellulose
(TAC).
It is preferable that the first transparent substrate 214A and the second
transparent substrate 214B be each formed using a plastic film or a plastic plate made of
PET (melting point: 258°C), PEN (melting point: 269°C), PE (melting point: 135°C), PP
10 (melting point: 163°C), polystyrene (melting point: 230°C), polyvinyl chloride (melting
point: 180°C), polyvinylidene chloride (melting point: 212°C), or TAC (melting point:
290°C) having a melting point of about 290°C or less. In particular, PET is preferable
from the perspective of the light transmissivity, the workability, and the like. Because
transparent conductive films such as the first conductive sheet 212A and the second
15 conductive sheet 212B used in the conductive sheet 210 for the touch panel are required
to have transparency, it is preferable that the degree of transparency of each of the first
transparent substrate 214A and the second transparent substrate 214B be high.
[Silver Salt Emulsion Layer]
A silver salt emulsion layer that becomes each of the first electrode pattern
20 216A of the first conductive sheet 212A and the second electrode pattern 216B of the
second conductive sheet 212B contains additives such as a solvent and a colorant in
addition to a silver salt and a binder.
Examples of the silver salt used in the present embodiment include inorganic
silver salts such as silver halide and organic silver salts such as silver acetate. In the
25 present embodiment, it is preferable to use silver halide excellent in characteristics as an
optical sensor.
The amount of silver (the amount of silver salt) applied to the silver salt
emulsion layer is preferably 1 to 30 g/m2, more preferably 1 to 25 g/m2, and further
preferably 5 to 20 g/m2, in terms of silver. If the amount of applied silver is set within
30 this range, a desired surface resistance can be obtained in the case of manufacturing the
conductive sheet 210 for the touch panel.
62
Examples of the binder used in the present embodiment include gelatin,
polyvinyl alcohol (PVA), polyvinylpyrrolidone (PVP), polysaccharides such as starch,
cellulose and derivatives thereof, polyethylene oxide, polyvinylamine, chitosan,
polylysine, polyacrylic acid, polyalginic acid, polyhyaluronic acid, and carboxycellulose.
5 These substances each exhibit a neutral, anionic, or cationic property depending on the
ionicity of a functional group thereof.
The content of the binder in the silver salt emulsion layer in the present
embodiment is not particularly limited, and can be determined as appropriate within a
range in which the dispersibility and the adhesiveness can be obtained. The content of
10 the binder in the silver salt emulsion layer is preferably 1/4 or more, and more preferably
1/2 or more, in terms of the volume ratio of silver/binder. The volume ratio of
silver/binder is preferably 100/1 or less, more preferably 50/1 or less. Moreover, the
volume ratio of silver/binder is further preferably 1/1 to 4/1. The volume ratio of
silver/binder is most preferably 1/1 to 3/1. If the volume ratio of silver/binder in the
15 silver salt emulsion layer is set within this range, even in the case where the amount of
applied silver is adjusted, fluctuations in resistance value can be suppressed, and the
conductive sheet for the touch panel having a uniform surface resistance can be obtained.
Note that the volume ratio of silver/binder can be obtained by converting the amount of
silver halide/the amount of binder (weight ratio) in the raw material into the amount of
20 silver/the amount of binder (weight ratio) and further converting the amount of silver/the
amount of binder (weight ratio) into the amount of silver/the amount of binder (volume
ratio).

The solvent used to form the silver salt emulsion layer is not particularly limited,
25 and examples thereof include water, organic solvents (for example, alcohols such as
methanol, ketones such as acetone, amides such as formamide, sulfoxides such as
dimethylsulfoxide, esters such as ethyl acetate, and ethers), ionic liquids, and a mixture
solvent of these solvents.
The content of the solvent used to form the silver salt emulsion layer of the
30 present embodiment falls within a range of 30 to 90 mass% of the total mass of the silver
salt, the binder, and the like contained in the silver salt emulsion layer, and preferably
falls within a range of 50 to 80 mass% thereof.
63

Various additives used in the present embodiment are not particularly limited,
and known additives can be preferably used therein.
[Other Layer Configurations]
A protective layer 5 (not illustrated) may be provided on the silver salt emulsion
layer. The "protective layer" in the present embodiment means a layer made of a binder
such as gelatin and polymers, and is formed on the silver salt emulsion layer having
photosensitivity in order to produce effects of preventing scratches and improving
mechanical characteristics. The thickness of the protective layer is preferably 0.5 μm or
10 less. A method of applying and a method of forming the protective layer are not
particularly limited, and a known applying method and a known forming method can be
selected as appropriate. Moreover, for example, a basecoat layer may also be provided
under the silver salt emulsion layer.
Next, steps of the method of manufacturing the first conductive sheet 212A and
15 the second conductive sheet 212B are described.
[Exposure to Light]
The present embodiment includes the case where the first electrode pattern
216A and the second electrode pattern 216B are formed by printing. Besides the
printing, the first electrode pattern 216A and the second electrode pattern 216B are
20 formed by exposure to light, development, and the like. That is, a photosensitive
material having a silver-salt-containing layer or a photosensitive material to which
photopolymer for photolithography has been applied, which is provided on each of the
first transparent substrate 214A and the second transparent substrate 214B, is exposed to
light. The exposure to light can be performed using electromagnetic waves. Examples
25 of the electromagnetic waves include light such as visible light rays and ultraviolet rays
and radiant rays such as X-rays. Further, a light source having wavelength distribution
may be used for the exposure to light, and a light source having a particular wavelength
may be used therefor.
A method using a glass mask and a pattern exposure method using laser drawing
30 are preferable for the exposure method.
[Development Process]
64
In the present embodiment, after the emulsion layer is exposed to light, the
development process is further performed. A technique of a standard development
process used for silver halide photographic films, printing paper, printing plate-making
films, photomask emulsion masks, and the like can be used for the development process.
5 The developing solution is not particularly limited, and a PQ developing solution, an MQ
developing solution, an MAA developing solution, and the like can be used therefor.
Examples of the usable developing solutions include: CN-16, CR-56, CP45X, FD-3, and
Papitol (produced by Fujifilm Corporation); C-41, E-6, RA-4, D-19, and D-72 (produced
by Kodak Company); and developing solutions included in kits thereof, which are
10 commercially available. Moreover, a lith-developing solution can also be used.
The development process in the present embodiment can include a fixing
process performed for the purpose of stabilization by removing the silver salt in the
unexposed part. A technique of a fixing process used for silver halide photographic
films, printing paper, printing plate-making films, photomask emulsion masks, and the
15 like can be used for the fixing process in the present invention.
The fixing temperature in the fixing process is preferably about 20°C to about
50°C and further preferably 25°C to 45°C. Moreover, the fixing time is preferably 5
seconds to 1 minute and further preferably 7 seconds to 50 seconds. The replenisher
rate of the fixing solution is preferably 600 ml/m2 or less, further preferably 500 ml/m2 or
20 less, and particularly preferably 300 ml/m2 or less, with respect to the processing amount
of the photosensitive material.
It is preferable that the photosensitive material that has been subjected to the
development and fixing process be subjected to a water washing process and a
stabilization process. The water washing process or the stabilization process is
25 normally performed at a washing water amount of 20 liters or less, and can be performed
even at a replenisher rate of 3 liters or less (including 0, that is, stored water washing),
per square meter of the photosensitive material.
The mass of metal silver contained in the exposed part after the development
process is preferably 50 mass% or more of the mass of silver contained in the exposed
30 part before the exposure to light, and is further preferable 80 mass% or more thereof. If
the mass of silver contained in the exposed part is 50 mass% or more of the mass of
65
silver contained in the exposed part before the exposure to light, high conductive
properties can be obtained, which is preferable.
The gradation after the development process in the present embodiment is not
particularly limited, and preferably exceeds 4.0. If the gradation after the development
process exceeds 5 4.0, the conductive properties of the conductive metal part can be
improved while the translucency of the light transmissive part is kept high. Examples
of means for making the gradation 4.0 or more include the doping with rhodium ions and
iridium ions described above.
The conductive sheet is obtained through the above-mentioned steps, and the
10 surface resistance of the obtained conductive sheet is preferably 100 Ω/sq. or less,
preferably falls within a range of 0.1 to 100 Ω/sq., and more preferably falls within a
range of 1 to 10 Ω/sq. If the surface resistance is adjusted to such a range, position
detection is possible for even a large-size touch panel having an area of 10 cm × 10 cm
or more. Moreover, the conductive sheet after the development process may be further
15 subjected to a calendering process, and the surface resistance can be adjusted to a desired
value by the calendering process.
[Physical Development and Plating Process]
In the present embodiment, physical development and/or a plating process for
causing the metal silver part to support conductive metal grains may be performed for the
20 purpose of enhancing the conductive properties of the metal silver part formed by the
exposure to light and the development process. In the present invention, the metal
silver part may be caused to support conductive metal grains through only any one of the
physical development and the plating process, and the metal silver part may be caused to
support conductive metal grains through a combination of the physical development and
25 the plating process. Note that the metal silver part that has been physically developed
and/or plated is also referred to as "conductive metal part".
[Oxidation Process]
In the present embodiment, it is preferable that the metal silver part after the
development process and the conductive metal part formed by the physical development
30 and/or the plating process be subjected to an oxidation process. For example, in the
case where a slight amount of metal is deposited in the light transmissive part, the
66
oxidation process can remove the metal, and can make the transmissivity of the light
transmissive part substantially 100%.
[Electrode Patterns]
The wire width of each of the metal thin wires of the first electrode pattern 216A
5 and the second electrode pattern 216B of the present embodiment can be selected from
30 μm or less. For use in the material of the touch panel, the metal thin wires each have
a wire width of 0.5 μm to 30 μm. It is desirable that the wire width of each metal thin
wire be 30 μm or less, preferably 15 μm or less, more preferably 10 μm or less, more
preferably 9 μm or less, and more preferably 7 μm or less, and be preferably 0.5 μm or
10 more.
The wire interval (grid pitch) is preferably 250 μm to 900 μm, and is further
preferably 300 μm or more and 700 μm or less. Moreover, each metal thin wire may
have a portion wider than 200 μm, for the purpose of ground connection and other
purposes.
15 In the electrode patterns of the present embodiment, the opening ratio is
preferably 85% or more, further preferably 90% or more, and most preferably 95% or
more, in terms of the visible light transmittance. The opening ratio is the percentage of
a translucent portion of each of the first electrode pattern 216A and the second electrode
pattern 216B excluding the metal thin wires. For example, the opening ratio is 90% in
20 the case of the square grids 224A and 224B having a wire width of 15 μm and a pitch of
300 μm.
[Light transmissive part]
The "light transmissive part" in the present embodiment means a translucent
portion other than the first electrode pattern 216A and the second electrode pattern 216B,
25 of each of the first conductive sheet 212A and the second conductive sheet 212B. As
described above, the transmittance of the light transmissive part is 90% or more,
preferably 95% or more, further preferably 97% or more, further more preferably 98% or
more, and most preferably 99% or more, in terms of the transmittance indicated by the
minimum value of the transmittance in a wavelength region of 380 to 780 nm excluding
30 contributions to light absorption and reflection of the first transparent substrate 214A and
the second transparent substrate 214B.
[First Conductive Sheet 212A and Second Conductive Sheet 212B]
67
The thickness of each of the first transparent substrate 214A and the second
transparent substrate 214B in the first conductive sheet 212A and the second conductive
sheet 212B according to the present embodiment is preferably 5 to 350 μm and further
preferably 30 to 150 μm. If the thickness thereof is set within such a range of 5 to 350
5 μm, a desired transmittance of visible light can be obtained, and handling is easy.
The thickness of the metal silver part provided on each of the first transparent
substrate 214A and the second transparent substrate 214B can be determined as
appropriate in accordance with the application thickness of coating for the silver-saltcontaining
layer applied onto each of the first transparent substrate 214A and the second
10 transparent substrate 214B. The thickness of the metal silver part can be selected from
0.001 mm to 0.2 mm, and is preferably 30 μm or less, more preferably 20 μm or less,
further preferably 0.01 to 9 μm, and most preferably 0.05 to 5 μm. Moreover, it is
preferable that the metal silver part be patterned. The metal silver part may have a
single-layered structure, and may have a multi-layered structure of two or more layers.
15 In the case where the metal silver part is patterned and has a multi-layered structure of
two or more layers, the metal silver part can be provided with different color sensitivities
so as to be reactive to different wavelengths. As a result, if the metal silver part is
exposed to light with different wavelengths, different patterns can be formed in the
respective layers.
20 For use in a touch panel, a smaller thickness of the conductive metal part is
more preferable, because the viewing angle of a display panel is wider. Also in terms
of enhancement in visibility, a reduction in thickness of the conductive metal part is
required. From such perspectives, the thickness of the layer made of the conductive
metal supported by the conductive metal part is preferably less than 9 μm, more
25 preferably 0.1 μm or more and less than 5 μm, and further preferably 0.1 μm or more and
less than 3 μm.
In the present embodiment, the metal silver part having a desired thickness can
be formed by controlling the application thickness of the silver-salt-containing layer, and
the thickness of the layer made of the conductive metal grains can be freely controlled by
30 the physical development and/or the plating process. Hence, even the first conductive
sheet 212A and the second conductive sheet 212B each having a thickness that is less
than 5 μm and preferably less than 3 μm can be easily formed.
68
Note that the method of manufacturing the first conductive sheet 212A and the
second conductive sheet 212B according to the present embodiment does not necessarily
need to include the plating step and the like. This is because the method of
manufacturing the first conductive sheet 212A and the second conductive sheet 212B
according to the present embodiment can o 5 btain a desired surface resistance by adjusting
the amount of applied silver and the volume ratio of silver/binder of the silver salt
emulsion layer. Note that a calendering process and the like may be performed as
needed.
(Hardening Process after Development Process)
10 It is preferable to perform a hardening process on the silver salt emulsion layer
by immersing the same in a hardener after performing the development process thereon.
Examples of the hardener include: dialdehydes such as glutaraldehyde, adipaldehyde,
and 2,3-dihydroxy-1,4-dioxane; and inorganic compounds such as boric acid and chrome
alum/potassium alum, which are described in Japanese Patent Application Laid-Open No.
15 2-141279.
Note that the present invention can be used in appropriate combination with
techniques disclosed in the following Japanese Patent Application Laid-Opens and
pamphlets of International Publications in Table 1 and Table 2. Expressions such as
"Japanese Patent Application Laid-Open No." and "Pamphlet of International Publication
20 No. WO" are omitted.
69
[Table 1]
2004-221564 2004-221565 2007-200922 2006-352073 2007-129205
2007-235115 2007-207987 2006-012935 2006-010795 2006-228469
2006-332459 2009-21153 2007-226215 2006-261315 2007-072171
2007-102200 2006-228473 2006-269795 206-269795 2006-324203
2006-228478 2006-228836 2007-009326 2006-336090 2006-336099
2006-348351 2007-270321 2007-270322 2007-201378 2007-335729
2007-134439 2007-149760 2007-208133 2007-178915 2007-334325
2007-310091 2007-116137 2007-088219 2007-207883 2007-013130
2005-302508 2008-218784 2008-227350 2008-227351 2008-244067
2008-267814 2008-270405 2008-277675 2008-277676 2008-282840
2008-283029 2008-288305 2008-288419 2008-300720 2008-300721
2009-4213 2009-10001 2009-16526 2009-21334 2009-26933
2008-147507 2008-159770 2008-159771 2008-171568 2008-198388
2008-218096 2008-218264 2008-224916 2008-235224 2008-235467
2008-241987 2008-251274 2008-251275 2008-252046 2008-277428
[Table 2]
2006/001461 2006/088059 2006/098333 2006/098336 2006/098338
2006/098335 2006/098334 2007/001008
5 Examples
Hereinafter, the present invention is further specifically described by way of
examples of the present invention. Note that materials, usage amounts, percentages,
processing contents, processing procedures, and the like described in the following
examples can be changed as appropriate within a range not departing from the gist of the
10 present invention. Accordingly, the scope of the present invention should not be
limitatively interpreted by way of the following specific examples.

(Silver Halide Photosensitive Material)
Prepared was an emulsion containing 10.0 g of gelatin for 150 g of Ag in an
15 aqueous medium and containing silver iodobromochloride grains (I = 0.2 mol%, Br = 40
mol%) having a sphere-equivalent diameter of 0.1 μm on average.
70
Moreover, K3Rh2Br9 and K2IrCl6 were added to the emulsion at a concentration
of 10-7 (mole/mole silver), and the silver bromide grains were doped with Rh ions and Ir
ions. Na2PdCl4 was added to the emulsion, and was further subjected to gold-sulfur
sensitization using chlorauric acid and sodium thiosulfate. Then, together with a gelatin
hardener, the e 5 mulsion was applied onto the substrate 30 (here, polyethylene
terephthalate (PET)) at a silver application amount of 10 g/m2. At that time, the volume
ratio of Ag/gelatin was set to 2/1.
Such application was performed on a PET support having a width of 30 cm, at a
width of 25 cm and a length of 20 m. Both the ends of the PET support were cut off by
10 3 cm for each end such that a central part (24 cm) of the application was left, whereby a
silver halide photosensitive material in a rolled state was obtained.
(Exposure to Light)
An exposure pattern for the first electrode pattern 10 was formed such that the
first electrode pattern 10 had the comb-shaped structure illustrated in Figure 5, by
15 forming the first conductive patterns 12 and the sub-nonconduction patterns 18. An
exposure pattern for the second electrode pattern 40 was formed such that the second
electrode pattern 40 had the strip-shaped structure illustrated in Figure 7. The exposure
to light was performed through photomasks having such patterns as described above,
using parallel light emitted from a light source that was a high-pressure mercury lamp.
20 (Development Process)
● Developing solution 1L prescription
hydroquinone 20 g
sodium sulfite 50 g
potassium carbonate 40 g
25 ethylenediaminetetraacetate 2 g
potassium bromide 3 g
polyethylene glycol 2000 1 g
potassium hydroxide 4 g
pH adjusted to 10.3
30 ● Fixing solution 1L prescription
ammonium thiosulfate solution (75%) 300 ml
ammonium sulfite monohydrate 25 g
71
1,3-diaminopropanetetraacetate 8 g
acetate 5 g
ammonia water (27%) 1 g
pH adjusted to 6.2
5 With the use of the above-mentioned processing solutions, the exposed
photosensitive material was processed by an automatic developing machine FG-710PTS
produced by Fujifilm Corporation, under processing conditions: 35°C and 30 seconds for
development; 34°C and 23 seconds for fixing; and flowing water (5L/min) and 20
seconds for water washing.
10 B (area of non-conductive pattern) / [A (area of first conductive pattern) + B
(area of non-conductive pattern)] was set to 5%. The width of each metal thin wire was
set to 5 μm, and the length of one side of each of the grids 26 and 46 was set to 250 μm.
(Levels 2 to 9)
According to the same method as that in Level 1, a plurality of conductive
15 sheets 1 having different values of B / (A + B) were made. Table 3 shows the values of
each level.
(Levels 10 to 20)
According to the same method as that in Level 1, a plurality of conductive
sheets 1 having different values of B / (A + B) were made, the conductive sheets 1 each
20 including: the first electrode pattern 10 including the first conductive patterns 12 each
having the X-shaped structures; and the second electrode pattern 40 including the second
conductive patterns 42 each having the strip-shaped structure. Table 1 shows the values
of each level.
72
[Table 3]
Level No.
First
Conductive
Pattern Shape
B/(A+B)
Total Width (Wa)
of First Conductive
Pattern Lines
Total Width (Wb)
of Nonconductive
Patterns
Sensitivity
of Finger
1 Comb-Shaped
Structure 5% 4.75 0.25 D
2 Comb-Shaped
Structure 10% 4.50 0.50 C
3 Comb-Shaped
Structure 20% 4.00 1.00 C
4 Comb-Shaped
Structure 40% 3.00 2.00 B
5 Comb-Shaped
Structure 50% 2.50 2.50 A
6 Comb-Shaped
Structure 60% 2.00 3.00 A
7 Comb-Shaped
Structure 80% 1.00 4.00 C
8 Comb-Shaped
Structure 97% 0.15 4.85 D
9 Comb-Shaped
Structure 0% 5.00 0.00 D
10 X-Shaped
Structures 5% - - D
11 X-Shaped
Structures 10% - - C
12 X-Shaped
Structures 20% - - B
13 X-Shaped
Structures 30% - - A
14 X-Shaped
Structures 45% - - A
15 X-Shaped
Structures 50% - - A
16 X-Shaped
Structures 65% - - C
17 X-Shaped
Structures 70% - - C
18 X-Shaped
Structures 80% - - C
19 X-Shaped
Structures 97% - - D
20 X-Shaped
Structures 0% - - D
(Evaluations)
For Levels 1 to 20, when a finger was brought into contact, it was determined
whether or not the touch with finger 5 could be sensed. A was given to the case where
the touch with finger could be sufficiently sensed. B was given to the case where the
contact thereof could be sensed with almost no problem. C was given to the case where
73
the contact thereof could not be stably sensed. D was given to the case where the
contact thereof could hardly be sensed.
With regard to the first conductive patterns each having the comb-shaped
structure and the first conductive patterns each having the X-shaped structures, favorable
results were obtained in 5 a range of 5% < B / (A + B) < 97%, and further preferable
results were obtained in a range of 10% ≤ B / (A + B) ≤ 80%.
As shown in Table 4, with regard to the first conductive patterns each having the
comb-shaped structure in Levels 21 to 25, most preferable results were obtained in a
range of 40% ≤ B / (A + B) ≤ 60%. With regard to the first conductive patterns each
10 having the X-shaped structures, further favorable results were obtained in a range of 30%
≤ B2 / (A2 + B2) ≤ 50%, and most preferable results were obtained in a range of 20% ≤
B2 / (A2 + B2) ≤ 50%.
[Table 4]
Level No.
First
Conductive
Pattern Shape
B/(A+B)
Total Width (Wa) of
First Conductive
Pattern Lines
Total Width (Wb)
of Nonconductive
Patterns
Sensitivity
of Finger
21 Comb-Shaped
Structure 50% 1.00 1.00 A
22 Comb-Shaped
Structure 50% 5.00 5.00 A
23 Comb-Shaped
Structure 60% 1.00 1.50 A
24 Comb-Shaped
Structure 60% 2.50 3.75 A
25 Comb-Shaped
Structure 60% 3.33 5.00 A
15 (Evaluations)
With regard to the first conductive patterns each having the comb-shaped
structure in Levels 21 to 25, most preferable results were obtained in the case of a
combination of (1) 1.0 mm ≤ Wa ≤ 5.0 mm and (2) 1.5 mm ≤ Wb ≤ 5.0 mm, in a range of
50% ≤ B / (A + B) ≤ 60%.
20 Next, for laminated conductive sheets according to Levels 26 to 33, the surface
resistance and the transmittance were measured, and moire patterns and the visibility
were evaluated. The details of Levels 26 to 33, the measurement results, and the
evaluation results are shown in Table 5.

25 (Silver Halide Photosensitive Material)
74
Prepared was an emulsion containing 10.0 g of gelatin for 150 g of Ag in an
aqueous medium and containing silver iodobromochloride grains (I = 0.2 mol%, Br = 40
mol%) having a sphere-equivalent diameter of 0.1 μm on average.
Moreover, K3Rh2Br9 and K2IrCl6 were added to the emulsion at a concentration
of 10-7 (mole/mole silver), and the silver 5 bromide grains were doped with Rh ions and Ir
ions. Na2PdCl4 was added to the emulsion, and was further subjected to gold-sulfur
sensitization using chlorauric acid and sodium thiosulfate. Then, together with a gelatin
hardener, the emulsion was applied onto each of the first transparent substrate 214A and
the second transparent substrate 214B (here, polyethylene terephthalate (PET)) at a silver
10 application amount of 10 g/m2. At that time, the volume ratio of Ag/gelatin was set to
2/1.
Such application was performed on a PET support having a width of 30 cm, at a
width of 25 cm and a length of 20 m. Both the ends of the PET support were cut off by
3 cm for each end such that a central part (24 cm) of the application was left, whereby a
15 silver halide photosensitive material in a rolled state was obtained.
(Exposure to Light)
An exposure pattern for the first conductive sheet 212A was a pattern illustrated
in Figure 34 and Figure 36, and was formed on the first transparent substrate 214A
having an A4-size (210 mm × 297 mm). An exposure pattern for the second conductive
20 sheet 212B was a pattern illustrated in Figure 34 and Figure 37, and was formed on the
second transparent substrate 214B having an A4-size (210 mm × 297 mm). The
exposure to light was performed through photomasks having such patterns as described
above, using parallel light emitted from a light source that was a high-pressure mercury
lamp.
25 (Development Process)
● Developing solution 1L prescription
hydroquinone 20 g
sodium sulfite 50 g
potassium carbonate 40 g
30 ethylenediaminetetraacetate 2 g
potassium bromide 3 g
polyethylene glycol 2000 1 g
75
potassium hydroxide 4 g
pH adjusted to 10.3
● Fixing solution 1L prescription
ammonium thiosulfate solution (75%) 300 ml
5 ammonium sulfite monohydrate 25 g
1,3-diaminopropanetetraacetate 8 g
acetate 5 g
ammonia water (27%) 1 g
pH adjusted to 6.2
10 With the use of the above-mentioned processing solutions, the exposed
photosensitive material was processed by the automatic developing machine FG-710PTS
produced by Fujifilm Corporation, under processing conditions: 35°C and 30 seconds for
development; 34°C and 23 seconds for fixing; and flowing water (5L/min) and 20
seconds for water washing.
15 (Level 26)
The wire width of each of conductive parts (the first electrode pattern 216A and
the second electrode pattern 216B) of the made first conductive sheet 212A and the made
second conductive sheet 212B was set to 1 μm, and the length of one side of each of the
grids 224A and 224B was set to 50 μm.
20 (Level 27)
The first conductive sheet 212A and the second conductive sheet 212B
according to Level 22 were made in a manner similar to that in Level 21, except that the
wire width of each conductive part was set to 3 μm and that the length of one side of
each of the grids 2224A and 224B was set to 100 μm.
25 (Level 28)
The first conductive sheet 212A and the second conductive sheet 212B
according to Level 23 were made in a manner similar to that in Level 21, except that the
wire width of each conductive part was set to 4 μm and that the length of one side of
each of the grids 224A and 224B was set to 150 μm.
30 (Level 29)
The first conductive sheet 212A and the second conductive sheet 212B
according to Level 24 were made in a manner similar to that in Level 21, except that the
76
wire width of each conductive part was set to 5 μm and that the length of one side of
each of the grids 224A and 224B was set to 210 μm.
(Level 30)
The first conductive sheet 212A and the second conductive sheet 212B
according to Level 25 were made in a manner similar 5 to that in Level 21, except that the
wire width of each conductive part was set to 8 μm and that the length of one side of
each of the grids 224A and 224B was set to 250 μm.
(Level 31)
The first conductive sheet 212A and the second conductive sheet 212B
10 according to Level 26 were made in a manner similar to that in Level 21, except that the
wire width of each conductive part was set to 9 μm and that the length of one side of
each of the grids 224A and 224B was set to 300 μm.
(Level 32)
The first conductive sheet 212A and the second conductive sheet 212B
15 according to Level 27 were made in a manner similar to that in Level 21, except that the
wire width of each conductive part was set to 10 μm and that the length of one side of
each of the grids 224A and 224B was set to 300 μm.
(Level 33)
The first conductive sheet 212A and the second conductive sheet 212B
20 according to Level 28 were made in a manner similar to that in Level 21, except that the
wire width of each conductive part was set to 15 μm and that the length of one side of
each of the grids 224A and 224B was set to 400 μm.
(Surface Resistance Measurement)
In order to check whether or not the detection accuracy was sufficient, the
25 surface resistance of each of the first conductive sheet 212A and the second conductive
sheet 212B was obtained as the average value of values that were measured at arbitrary
ten points using a four-point probe array (ASP), Loresta GP (Model No. MCP-T610)
produced by Dia Instruments Co., Ltd.
(Transmittance Measurement)
30 In order to check whether or not the transparency was sufficient, the
transmittance of each of the first conductive sheet 212A and the second conductive sheet
212B was measured using a spectrophotometer.
77
(Moire Pattern Evaluation)
In each of Levels 26 to 33, a laminated conductive sheet was made by
laminating the first conductive sheet 212A on the second conductive sheet 212B. After
that, a touch panel was manufactured by attaching the laminated conductive sheet to a
display screen of a liquid 5 crystal display device. After that, the touch panel was set on a
spinning disk, and the liquid crystal display device was driven to display a white color.
In that state, the spinning disk was spun at a bias angle between -45° and +45°, and
moire patterns were visually observed and evaluated.
The moire patterns were evaluated at an observation distance of 1.5 m from the
10 display screen of the liquid crystal display device. A was given to the case where the
moire patterns were not obviously found. B was given to the case where the moire
patterns were slightly found in a non-problematic level. C was given to the case where
the moire patterns were obviously found.
(Visibility Evaluation)
15 Prior to the moire pattern evaluation described above, when the touch panel was
set on the spinning disk and when the liquid crystal display device was driven to display
a white color, it was checked with naked eyes whether or not there were thicker lines and
black spots and whether or not the break parts of the first conductive sheet 212A and the
second conductive sheet 212B stood out.
20 [Table 5]
Level No.
Wire Width
(μm) of
Conductive
Pattern
Length
(μm) of
One Side of
Grid
Surface
Resistance
(Ω/sq.)
Transmittance
(%)
Moire
Pattern
Evaluation
Visibility
Evaluation
26 1 50 55 85 A A
27 3 100 55 86 A A
28 4 150 50 87 A A
29 5 210 40 88 A A
30 8 250 50 87 A A
31 9 300 45 86 A A
32 10 300 40 86 A A
33 15 400 38 85 B B
In this regard, for Levels 26 to 32 of Levels 26 to 33, all of the conductive
properties, the transmittance, the moire patterns, and the visibility were favorable.
Although Level 33 was inferior to Levels 26 to 32 in the moire pattern evaluation and the
25 visibility evaluation, the moire patterns slightly found in Level 33 were in a non78
problematic level, and did not hinder observation of an image displayed on the display
device.
Moreover, a projected capacitive touch panel was made using the laminated
conductive sheet according to each of Levels 26 to 33. When the projected capacitive
5 touch panel was operated by touching with a finger, it was found out that the response
speed was high and that the detection sensitivity was excellent. Moreover, when the
projected capacitive touch panel was operated by touching two or more points, it was
confirmed that favorable results could be similarly obtained and that multi-touch input
could be dealt with.
10 The conductive sheet for the touch panel and the touch panel according to the
present invention are not limited to the above-mentioned embodiments, and can have
various configurations without departing from the gist of the present invention, as a
matter of course.
15 {Reference Signs List}
1 ... conductive sheet, 10 ... first electrode pattern, 12 ... first conductive pattern,
14 ... first electrode terminal, 16 ... first wire, 18 ... sub-nonconduction pattern, 20 ...
terminal, 22 ... first conductive pattern line, 24 ... additional first electrode terminal, 26 ...
grid, 40 ... second electrode pattern, 42 ... second conductive pattern, 44 ... second
20 electrode terminal, 46 ... second wire, 50 ... terminal, 54 ... additional second electrode
terminal, 56 ... grid, 70 ... combination pattern, 76 ... small grid, 210 ... conductive sheet
for touch panel, 212A ... first conductive sheet, 212B ... second conductive sheet, 214A ...
first transparent substrate, 214B ... second transparent substrate, 216A ... first electrode
pattern, 216B ... second electrode pattern, 218A ... first conductive pattern, 218B ...
25 second conductive pattern, 220A ... first nonconductive pattern, 220B ... second
nonconductive pattern, 222A ... break part, 222B ... break part, 224A ... grid, 224B ...
grid, 270 ... combination pattern, 276 ... small grid
79
{CLAIMS}
1. A conductive sheet comprising:
a substrate having a first main surface and a second main surface; and
a fir 5 st electrode pattern placed on the first main surface of the substrate, wherein
the first electrode pattern is made of metal thin wires, and alternately includes: a
plurality of first conductive patterns that extend in a first direction; and a plurality of first
nonconductive patterns that are electrically separated from the plurality of first
conductive patterns,
10 each of the first conductive patterns includes, at least, inside thereof, a subnonconduction
pattern that is electrically separated from the first conductive pattern, and
an area A of each first conductive pattern and an area B of each subnonconduction
pattern satisfy a following expression.
5% < B / (A + B) < 97%
15
2. The conductive sheet according to claim 1, wherein the area A of each first
conductive pattern and the area B of each sub-nonconduction pattern satisfy a following
expression.
10% ≤ B / (A + B) ≤ 80%
20
3. The conductive sheet according to claim 2, wherein the area A of each first
conductive pattern and the area B of each sub-nonconduction pattern satisfy a following
expression.
10% ≤ B / (A + B) ≤ 60%
25
4. The conductive sheet according to any one of claims 1 to 3, wherein
each sub-nonconduction pattern has a slit-like shape extending in the first
direction,
each first conductive pattern includes a plurality of first conductive pattern lines
30 divided by each sub-nonconduction pattern, and
an area A1 of each first conductive pattern and an area B1 of each subnonconduction
pattern satisfy a following expression.
80
40% ≤ B1 / (A1 + B1) ≤ 60%
5. The conductive sheet according to claim 4, wherein a total width Wa of widths
of the first conductive pattern lines and a total width Wb of: a total width of widths of the
5 sub-nonconduction patterns; and a width of the first nonconductive pattern satisfy
relations of following expressions (1) and (2).
(1) 1.0 mm ≤ Wa ≤ 5.0 mm
(2) 1.5 mm ≤ Wb ≤ 5.0 mm
10 6. The conductive sheet according to claim 1 or 2, wherein
the first conductive pattern has X-shaped structures with cyclical intersections,
and
an area A2 of the first conductive pattern and an area B2 of the subnonconduction
pattern satisfy a following expression.
15 20% ≤ B2 / (A2 + B2) ≤ 50%
7. The conductive sheet according to claim 1 or 2, wherein
the first conductive pattern has X-shaped structures with cyclical intersections,
and
20 an area A2 of the first conductive pattern and an area B2 of the subnonconduction
pattern satisfy a relation of following expressions (1).
30% ≤ B2 / (A2 + B2) ≤ 50%
30% ≤ B2 / (A2 + B2) ≤ 50%
25 8. The conductive sheet according to any one of claims 1 to 7, further comprising
a second electrode pattern placed on the second main surface of the substrate,
wherein
the second electrode pattern is made of metal thin wires, and includes a plurality
of second conductive patterns that extend in a second direction orthogonal to the first
30 direction.
9. The conductive sheet according to any one of claims 1 to 8, wherein
81
the plurality of first conductive patterns are formed by grids having uniform
shapes, and
each of the grids has one side having a length that is equal to or more than 250
μm and equal to or less than 900 μm.
5
10. The conductive sheet according to any one of claims 1 to 9, wherein each of the
metal thin wires that form the first electrode pattern and/or the metal thin wires that form
the second electrode pattern has a wire width equal to or less than 30 μm.
10 11. The conductive sheet according to claim 4, wherein a width of the first
conductive pattern line and a width of the sub-nonconduction pattern are substantially
equal to each other.
12. The conductive sheet according to claim 4, wherein a width of the first
15 conductive pattern line is smaller than a width of the sub-nonconduction pattern.
13. The conductive sheet according to claim 4, wherein a width of the first
conductive pattern line is larger than a width of the sub-nonconduction pattern.
20 14. The conductive sheet according to any one of claims 11 to 13, wherein the first
electrode pattern includes a joining part that electrically connects the plurality of first
conductive pattern lines to each other.
15. The conductive sheet according to claim 4, wherein a number of the first
25 conductive pattern lines is equal to or less than ten.
16. The conductive sheet according to claim 6, wherein
the sub-nonconduction pattern is surrounded by a plurality of sides, and
the sides are formed by linearly arranging a plurality of grids that form the first
30 conductive pattern, with sides of the grids being connected to each other.
17. The conductive sheet according to claim 6, wherein
82
the sub-nonconduction pattern is surrounded by a plurality of sides, and
the sides are formed by linearly arranging, in multiple stages, a plurality of grids
that form the first conductive pattern, with sides of the grids being connected to each
other.
5
18. The conductive sheet according to claim 6, wherein
the sub-nonconduction pattern is surrounded by a plurality of sides,
some of the sides are formed by linearly arranging a plurality of grids that form
the first conductive pattern, with sides of the grids being connected to each other, and
10 the other sides are formed by linearly arranging the plurality of grids with apex
angles of the grids being connected to each other.
19. The conductive sheet according to any one of claims 16 to 18, wherein a
plurality of the sub-nonconduction patterns defined by the sides formed by the plurality
15 of grids are arranged along the first direction with apex angles of the grids being
connected to each other.
20. The conductive sheet according to any one of claims 16 to 19, wherein adjacent
ones of the sub-nonconduction patterns along the first direction have shapes different
20 from each other.
21. The conductive sheet according to any one of claims 16 to 20, wherein the
plurality of grids that form the sides which define the sub-nonconduction pattern further
includes a protruding wire made of a metal thin wire.
25
22. The conductive sheet according to any one of claims 16 to 21, wherein the first
conductive pattern includes the sub-nonconduction patterns at predetermined intervals, to
thereby has X-shaped structures in which the grids are not present at cyclical intersection
parts.
30
23. The conductive sheet according to any one of claims 16 to 22, wherein
83
adjacent ones of the sub-nonconduction patterns along the first direction have
same shape as each other in the first conductive pattern, and
the sub-nonconduction patterns have shapes different between adjacent ones of
the first conductive patterns.
5
24. A touch panel comprising the conductive sheet according to any one of claims 1
to 23.