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D E S C R I P T I O N
Title of Invention:
SUBSTRATE FOR LIQUID CRYSTAL DISPLAY
5 AND LIQUID CRYSTAL DISPLAY DEVICE
Technical Field
| An Embodiment of the present invention relate to a
\ substrate for liquid crystal display, and a liquid
10 crystal display device including the substrate for
| liquid crystal display.
Background Art
With progressing reduction in a weight of an
electronic device using a liquid crystal display device
15 in recent years, opportunities in which an information
device such as a portable phone or mobile PC is used in
a public place are increasing. When the information
device is used in the public place, there is a
possibility that secret information or private
20 information displayed in the liquid crystal display
device is visually recognized by the other therearound.
When the liquid crystal display device is caused
to display secret information or private information in
the public place, it is preferable that a field of view
25 of the liquid crystal display device is narrow. When
information displayed in the liquid crystal display
device is viewed by a plurality of persons, it
preferable that the field of view of the liquid crystal
display device is wide. There are generally two
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methods of field-of-view control.
A first field-of-view control method is disclosed
by Patent Literature 1 (Japanese Patent No. 3322197)
and Patent Literature 2 (Japanese Patent No. 4367206).
5 In the first field-of-view control method, two panels
including a display panel including a liquid crystal
display element to make a main display and a viewing
angle control panel including a liquid crystal element
for viewing angle control that switches a wide field of
10 view and a narrow field of view are used. In Patent
Literature 1, the liquid crystal element for viewing
angle control is an element for phase difference
control and the wide field of view and the narrow field
of view are switched based on whether a voltage is
15 applied to the element for phase difference control.
Patent Literature 2 discloses a technology that makes
the display of the liquid crystal display device harder
to view by forming a checker flag pattern including a
bright region and a dark region in a formation region
20 of a liquid crystal element for viewing angle control.
In both cases of Patent Literature 1 and Patent
Literature 2, it is necessary to include a viewing
angle control panel in which the liquid crystal element
for viewing angle control is disposed, which may makes
25 the whole display device thicker and heavier and in
some cases impractical. If the display device becomes
thicker and heavier, user convenience of a portable
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personal terminal such as a portable phone, mobile PC
or the like decreases.
As a second field-of-view control method, a method
of adding new pixels for viewing angle control to a
5 display panel including a liquid crystal display
element for display or providing a region for viewing
angle control in a portion of display pixels formed in
a display panel is known. The second field-of-view
control method is suitable for a portable display
10 device because there is no need to add a viewing angle
control panel. Patent Literature 3 (Jpn. Pat. Appln.
KOKAI Publication No. 2010-128126) is an example of a
method of adding pixels for viewing angle control to a
display panel. According to Patent Literature 3, sub-
15 pixels for viewing angle control are used for viewing
angle control. Patent Literature 4 (Jpn. Pat. Appln.
KOKAI Publication No. 2007-65046) is an example of a
method of providing a region for viewing angle control
in a display panel. According to Patent Literature 4,
20 a first counter electrode and a second counter
electrode are provided in a pixel, different counter
voltages are applied for the first counter electrode
connected to a thin-film transistor and the second
counter electrode, and the second counter electrode is
25 used for viewing angle control. When pixels for
viewing angle control are included in a display panel
or a viewing angle control region in which a plurality
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of counter electrodes is separately formed is formed in
a display panel, an effective display area decreases so
that the display may be dark. By adopting the pixels
for viewing angle control or the viewing angle control
5 region, display content can be made more difficult for
third parties therearound to visually recognize the
content. However, light from the pixels for viewing
angle control or the viewing angle control region is
more likely to enter eyes even for an observer (a user
10 of the liquid crystal display device), leading to lower
display quality. In addition, the technology described
in Patent Literature 4 needs two counter voltages,
which makes a power supply system more complex.
Further, Patent Literature 4 does not discuss a VA
15 (Vertically Alignment) liquid crystal or ECB
(Electrically Changed Birefringence) liquid crystal
applied to a high-contrast liquid crystal display
device.
A liquid crystal display device of the normal VA
20 system or ECB system has a basic configuration in which
liquid crystals are sandwiched between a color filter
substrate including a common electrode and an array
substrate including a plurality of pixel electrodes
(for example, transparent electrodes electrically
25 connected to thin-film transistor (TFT) elements and
formed in a comb-like pattern) driving the liquid
crystals. In this configuration, a drive voltage is
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applied between the common electrode on the color
filter and pixel electrodes formed on the array
substrate side to drive the liquid crystals. Normally,
a thin film of conductive metal oxide such as ITO
5 (Indium Tin Oxide), IZO (Indium Zinc Oxide), and IGZO
(Indium Gallium Zinc Oxide) is used as a transparent
conductive film used for the pixel electrode and the
common electrode on the surface of the color filter.
In the conventional viewing angle control, as
10 described above, the liquid crystal display device may
become heavy and thick by including the viewing angle
control panel including the liquid crystal element for
viewing angle control.
Also in the conventional viewing angle control, an
15 effective aperture ratio may be decreased by including
the pixels for viewing angle control in the display
panel.
Summary of Invention
Technical Problem
20 An object of an embodiment of the present
invention is to provide a substrate for liquid crystal
display to execute effective viewing angle control by
preventing a liquid crystal display device from
becoming heavy and thick and preventing an aperture
25 ratio from decreasing and a liquid crystal display
device including the substrate for liquid crystal
display.
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Solution to the Problems
In a first aspect, a substrate for liquid crystal
display includes a polygonal pixel or a polygonal subpixel
and linear patterns. The polygonal pixel or the
5 polygonal sub-pixel includes parallel sides opposite to
each other in a plane shape. The linear patterns are
included on the parallel sides opposite to each other
of the polygonal pixel or the polygonal sub-pixel and
allows skew (or inclined) light to pass through.
10 In a second aspect, a liquid crystal display
device includes a substrate for liquid crystal display
and an array substrate. The substrate for liquid
crystal display includes a polygonal pixel or a
polygonal sub-pixel having parallel sides opposite to
15 each other in a plane shape and linear patterns
included on parallel sides opposite to each other of
the polygonal pixel or the polygonal sub-pixel to allow
skew light to pass through. The array substrate is
opposite to the substrate for liquid crystal display
20 via a liquid crystal layer and includes an active
element to drive liquid crystals of the liquid crystal
layer.
Advantageous Effects of Invention
According to the present invention, a liquid
25 crystal display device can be prevented from becoming
heavy and thick in viewing angle control and an
aperture ratio can be prevented from decreasing so that
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effective viewing angle control can be exercised.
Brief Description of Drawings
FIG. 1 is a partial sectional view showing an
example of a liquid crystal display device according to
5 a first embodiment.
FIG. 2 is a partial sectional view showing an
example of a substrate for liquid crystal display
according to the first embodiment.
FIG. 3 is a partial plan view showing an example
10 of the substrate for liquid crystal display according
to the first embodiment.
FIG. 4 is a partial sectional view showing an
example of a relationship between a configuration of
the liquid crystal display device according to the
15 first embodiment and skew light.
FIG. 5 is a partial sectional view showing a
modification of a shape of a transparent pattern in the
liquid crystal display device according to the first
embodiment.
20 FIG. 6 is a partial sectional view showing an
example of the liquid crystal display device when no
drive voltage is applied in the first embodiment.
FIG. 7 is a partial sectional view showing an
example of the liquid crystal display device
25 immediately after the drive voltage is applied.
FIG. 8 is a partial sectional view showing an
example of the liquid crystal display device when some
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time passes after the drive voltage is applied.
FIG. 9 is a partial sectional view showing an
example of an action of first electrodes PI to P3 and
second electrodes CI to C3 when no drive voltage is
5 applied (initial alignment state) in the liquid crystal
display device.
FIG. 10 is a partial sectional view showing an
example of the action of the first electrodes PI to P3
and the second electrodes CI to C3 when the drive
10 voltage is applied in the liquid crystal display
device.
FIG. 11 is a partial plan view showing a first
example of the first electrode included in the subpixel
.
15 FIG. 12 is a partial plan view showing a second
example of the first electrode included in the subpixel
.
FIG. 13 is a partial plan view showing a third
example of the first electrode included in the sub-
20 pixel.
FIG. 14 is a partial plan view showing a
modification of an arrangement of sub-pixels.
FIG. 15 is a plan view showing an example of a
relationship between a polygonal sub-pixel and first
25 electrodes PI to P6.
FIG. 16 is a partial sectional view showing an
example of a substrate for liquid crystal display
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according to a third embodiment.
FIG. 17 is a sectional view showing an example of
a configuration of an edge light type liquid crystal
display device.
5 FIG. 18 is a partial sectional view showing an
example of a liquid crystal display device in halftone
display after a drive voltage is applied.
FIG. 19 is a partial sectional view showing an
example of a liquid crystal display device according to
10 a sixth embodiment.
FIG. 20 is a partial sectional view showing a
first example of a configuration to drive liquid
crystals at low voltage in a liquid crystal display
device according to a seventh embodiment.
15 FIG. 21 is a partial sectional view showing a
second example of the configuration to drive the liquid
crystals at low voltage in the liquid crystal display
device according to the seventh embodiment.
Embodiments for Carrying Out the Invention
20 Embodiments of the present invention will be
described below with reference to the drawings. In the
description that follows, the same reference numerals
are attached to the same or substantially the same
functions and elements and the description thereof will
25 be provided when necessary.
(First embodiment)
In the present embodiment, a normally black liquid
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crystal display device including initial vertical
alignment liquid crystals or initial horizontal
alignment liquid crystals will be described. In the
present embodiment, a configuration in a unit of sub-
5 pixel will be described. However, a configuration
similar to that in the present embodiment may be
applied in a unit of pixel.
FIG. 1 is a partial sectional view showing an
example of a liquid crystal display device according to
10 the present embodiment. FIG. 1 is a cross section
perpendicular to a comb axis of a comb-like (may also
be stripe-like) electrode. In FIG. 1, an operation of
liquid crystals LI to L14 by a substrate for liquid
crystal display 2 and an array substrate 3 and skew
15 lights 8 realized by the operation are illustrated. In
FIG. 1, the illustration of a vertical alignment film,
polarizing plate, phase difference plate, and TFT is
omitted.
FIG. 2 is a partial sectional view showing an
20 example of the substrate for liquid crystal display 2
in FIG. 1.
FIG. 3 is a partial plan view showing an example
of the substrate for liquid crystal display 2 according
to the present embodiment. A-A' section in FIG. 3
25 corresponds to FIG. 1.
A liquid crystal display device 1 is assumed to be
a VA system or ECB system. Liquid crystals whose
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dielectric constant anisotropy are positive is used as
ECB liquid crystals.
In the liquid crystal display device 1, the
substrate for liquid crystal display 2 and the array
5 substrate 3 in which liquid crystal driving elements
(active element) such as TFT are formed are opposite to
each other. A liquid crystal layer 4 is sandwiched
between the substrate for liquid crystal display 2 and
the array substrate 3.
10 The plan view shape of an opening of a polygonal
sub-pixel arranged in a matrix shape is a polygon in
which opposite sides are parallel to each other like,
for example, a square, rectangle, parallelogram, and
polygon bent in a "<" formed dogleg-shape ("V" shape or
15 boomerang shape). In the example in FIG. 3, the
substrate for liquid crystal display 2 includes a
linear pattern 7 in which a linear transparent pattern
5 of a transparent resin layer is sandwiched between
linear light-shielding patterns 6 of a light-shielding
20 layer in at least two sides opposite to each other of
sides of a matrix pattern partitioning a plurality of
polygonal sub-pixels on a plane. In the liquid crystal
display device 1, the skew light 8 passing through the
transparent pattern 5 is used for viewing angle
25 control. In the linear pattern 7, the thickness in the
vertical direction of the transparent pattern 5 is
thicker than the thickness in the vertical direction of
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the light-shielding pattern 6. Therefore, the
transparent pattern 5 protrudes toward the side of the
liquid crystal layer 4 more than the light-shielding
pattern 6. Further, in the substrate for liquid
5 crystal display 2, the formation portion of the linear
pattern 7 is thicker than the formation portion of, for
example, color filters 10 to 12.
In the present embodiment, the liquid crystal
layer 4 is assumed to include VA liquid crystals.
10 Therefore, the liquid crystals LI to L14 of the liquid
crystal layer 4 are liquid crystals whose dielectric
constant anisotropy is negative. The initial alignment
of the liquid crystals LI to L14 of the liquid crystal
| layer 4 is vertical. In FIG. 1, excluding the liquid
I 15 crystals L3, L4, Lll, L12 near the boundaries between
the transparent patterns 5 and the light-shielding
patterns 6, the liquid crystals LI, L2, L5 to L10, L13,
L14 are aligned perpendicularly to the surface of the
substrate for liquid crystal display 2 and the array
20 substrate 3. In the present embodiment, a vertical
alignment film is used and alignment processing such as
photo alignment and rubbing can be omitted. In the
present embodiment, as will be described later, exact
pre-tilt control such as 89 degrees needed for the
25 conventional VA system is not needed and liquid
crystals of simple initial vertical alignment of, for
example, 90 degrees can be used.
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In the present embodiment, a liquid crystal
material containing fluorine atoms in the molecular
structure (hereinafter, referred to as a fluorine based
liquid crystal) is used as the liquid crystal material.
5 In the present embodiment, second electrodes CI to C6
protrude toward the transparent pattern 5 (from the
center toward the edge) more than the corresponding
first electrodes Pi to P6 in the horizontal direction.
When a drive voltage of the liquid crystals is applied,
10 a substantially strong electric field is generated
between the first electrodes PI to P6 and the second
electrodes CI to C6. Thus, in the present embodiment,
the liquid crystals can be driven by using a liquid
crystal material whose dielectric constant anisotropy
15 is smaller than that of a liquid crystal material used
for conventional vertical alignment. In general, a
liquid crystal material whose dielectric constant
anisotropy is smaller has a low viscosity. Therefore,
when an electric field strength of the same level is
20 applied between the first electrodes PI to P6 and the
second electrodes CI to C6, a liquid crystal material
whose dielectric constant anisotropy is small can
respond more quickly than a conventional liquid crystal
material. Moreover, because the fluorine based liquid
25 crystal has a low dielectric constant, the uptake of
ionic impurities can be reduced so that performance
degradation like a lower voltage retention caused by
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impurities can be prevented and an occurrence of uneven
display can be inhibited.
In the liquid crystal display device 1 in the
initial vertical alignment, in contrast to a liquid
5 crystal display device in the initial horizontal
alignment, alignment of optical axes of the polarizing
plate and the phase difference plate provided on both
sides or one side of the liquid crystal display device
1 may not be exact. In the liquid crystal display
10 device 1 in the initial vertical alignment, retardation
when no voltage is applied is, for example, 0 nm. Even
if the liquid crystals and, for example, a lagging axis
of the polarizing plate is slightly shifted in the
liquid crystal display device 1 in the initial vertical
15 alignment, light leakage is less likely to occur and an
almost complete black display can be obtained. If an
optical axe is shifted by several degrees between the
liquid crystals in the initial horizontal alignment and
a polarizing plate, light leakage occurs and the
20 contrast of the liquid crystal display device may be
somewhat degraded when compared with the liquid
crystals in the initial vertical alignment.
In the present embodiment, the array substrate 3
includes the first electrodes Pi to P6 as pixel
25 electrodes and the second electrodes CI to C6 as common
electrodes for each polygonal sub-pixel. Different
potentials are applied to the first electrodes PI to P6
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and the second electrodes CI to C6 to drive the liquid
crystals. Incidentally, the array substrate 3 may not
include the second electrodes CI to C6. In such a
case, the liquid crystal display device does not
5 include the second electrodes CI to C6 and is comprised
of the array substrate including the first electrodes
PI to P6 and active elements such as TFT and the
substrate for liquid crystal display 2. When the
second electrodes CI to C6 are omitted, the plan view
10 shape of the first electrodes PI to P6 may be a comblike
pattern or a pattern in which a plurality of slitlike
openings is formed in a solid transparent
conductive film.
In the example of FIGS. 1 and 2, the linear
15 pattern 7 is formed above one side of a transparent
substrate 9 such as glass. A third electrode 13 as a
transparent conductive film is formed above the
transparent substrate 9 and the linear pattern 7
including the transparent pattern 5 and the light-
20 shielding patterns 6 sandwiching the transparent
pattern 5 therebetween. Next, the red color filter 10,
the green color filter 11, and the blue color filter 12
are provided above the third electrode 13 in the
vertical direction and between the linear patterns 7
25 (in a position where the linear pattern 7 is not
formed) in the horizontal direction. Accordingly, a
configuration in which the linear patterns 7 are
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included at edges of the red color filter 10, the green
color filter 11, and the blue color filter 12 is
obtained. A protective layer 14 is stacked above the
third electrode 13 and also the red color filter 10,
5 the green color filter 11, and the blue color filter 12
when necessary.
In the example of FIG. 3, the arrangement
relationship between the red color filter 10, the green
color filter 11, and the blue color filter 12, and the
10 linear pattern 7 is shown. In the present embodiment,
active elements that drive the liquid crystals such as
TFT are arranged below the linear pattern 7 or below
the light-shielding pattern 6 in a direction
perpendicular to the plane of the liquid crystal
15 display device 1 (thickness direction). In the
sectional views of FIGS. 1 and 2, the substrate for
liquid crystal display 2 is in a state of 180° rotation
after a manufacturing process is completed. In the
manufacturing process of the substrate for liquid
20 crystal display 2, the linear pattern 7 is formed above
the transparent substrate 9. Next, the third electrode
13 is formed above the transparent substrate 9 and the
linear pattern 7. Next, the red color filter 10, the
green color filter 11, and the blue color filter 12 are
25 formed above the third electrode 13 and between the
linear patterns 7. Next, the protective layer 14 is
stacked above the red color filter 10, the green color
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filter 11, and the blue color filter 12 and the third
electrode 13 above the linear pattern 7 when necessary.
The side of the protective layer 14 of the
substrate for liquid crystal display 2 becomes the side
5 of the liquid crystal layer 4 of the liquid crystal
display device 1. The side of the transparent
substrate 9 of the substrate for liquid crystal display
2 becomes the side of an observer.
In the present embodiment, the skew light 8 passes
10 through the transparent pattern 5. The viewing angle
control is realized by the skew light 8.
The array substrate 3 includes a substrate 15,
insulating layers 16a to 16c, a metal wire 17, the
first electrodes PI to P6, and the second electrodes CI
15 to C6.
The insulating layer 16a is formed above the
substrate 15. The metal wire 17 is formed above the
insulating layer 16a. The metal wire 17 is formed in a
position overlapping with the linear pattern 7 in the
20 vertical direction of the liquid crystal display device
1. With this configuration, light in the vertical
direction is blocked by the metal wire 17 and is not
emitted from the transparent pattern 5 of the linear
pattern 7. The insulating layer 16b is formed above
25 the insulating layer 16a and the metal wire 17. The
second electrodes CI to C6 are formed above the
insulating layer 16b. The insulating layer 16c is
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formed above the insulating layer 16b and the second
electrodes CI to C6. The first electrodes PI to P6 are
formed above the insulating layer 16c.
FIG. 4 is a partial sectional view showing an
5 example of a relationship between the configuration of
the liquid crystal display device 1 according to the
present embodiment and the skew light 8. In FIG. 4,
only the left side from a center axis Z of the subpixel
is shown to simplify the description. Further,
10 in FIG. 4, a case when a first electrode P has a
rectangular shape is shown as an example. In FIG. 4,
the illustration of the vertical alignment film,
polarizing plate, phase difference plate, and TFT is
omitted.
15 The array substrate 3 includes the first electrode
P in a rectangular shape and TFT connected to the first
electrode P in a rectangular shape. The side of the
first electrode P of the array substrate 3 and the side
of a protective layer 14 of the substrate for liquid
20 crystal display 2 are opposite to each other via the
liquid crystal layer 4.
In FIG. 4, the liquid crystals LI to L6 have
negative dielectric constant anisotropy. Excluding the
liquid crystals L3, L4 near the boundary between the
25 transparent pattern 5 and the light-shielding pattern
6, the liquid crystals LI, L2, L5, L6 are aligned
perpendicularly to the surface of the substrate for
liquid crystal display 2 and the array substrate 3. In
an ECB system, the alignment film is rubbed and liquid
crystals of positive dielectric constant anisotropy are
aligned horizontally. It is assumed that the
5 polarizing plate is a cross Nicol and the liquid
crystal display device 1 is normally black. In the
array substrate 3, the metal wire 17 that can be used
as a signal line is arranged in a position overlapping
with the linear pattern 7 in the vertical direction.
10 Incidentally, the metal wire 17 is manufactured by
forming a light-shielding metal thin film used for TFT
manufacture as a pattern. The metal wire 17 may be any
of a video signal line, scan signal line, common
electrode wire, and common conductor wire used to
15 prevent an electrostatic breakdown of a TFT element
when an alignment film is rubbed. The distance between
the metal wire 17 and the first electrode P in the
vertical direction may be increased to avoid electric
crosstalk and unfavorable formation of a parasitic
20 capacitance.
In FIG. 4, no drive voltage is applied and a state
in which the liquid crystals LI, L2, L5, L6 are in the
initial vertical alignment is shown. The liquid
crystal L3 near the surface of the transparent pattern
25 5 is aligned slightly obliquely. The skew light 8
passes through the liquid crystal L3 by traversing the
liquid crystal obliquely. The skew light 8 has an I
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angle 6 with the liquid crystal L3 and thus, the liquid
crystal L3 gives a phase difference to the skew light
8. The skew light 8 passes through a polarizing plate
(not shown), and the skew light 8 is emitted to the
5 outside as a leaking light. In this case, the
transparent pattern 5 is visually recognized as a black
display from the direction of the observer, but a
leaking light is observed by a third party in an
oblique direction and the transparent pattern is not
10 visually recognized as a black display.
The amount of the leaking light and the angle 9 of
the skew light 8 can be controlled by a width Wl of the
transparent pattern 5, a width W2 of the linear pattern
7, a thickness HI of the transparent pattern 5, a
15 thickness Ht of the transparent pattern 5 and the
protective layer 14, a thickness Lt of the liquid
crystal layer 4, a width W3 of the metal wire 17, or a
pre-tilt angle of the liquid crystal L3 near the
surface of the transparent pattern 5.
20 FIG. 5 is a partial sectional view showing a
modification of a shape of the transparent pattern 5 in
the liquid crystal display device 1 according to the
present embodiment.
A side of a portion (tip portion of the section of
25 the transparent pattern 5) 5a of the section of the
transparent pattern 5 protruding to the side of the
liquid crystal layer 4 more than the light-shielding
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pattern 6 and the color filters 10 to 12 may be
inclined so that the closer to the tip, the thinner the
protruding portion 5a becomes. The protruding portion
5a of the transparent pattern 5 may be rounded off. By
5 adjusting the height of the protruding portion 5a of
the transparent pattern 5, leaking light can be reduced
by aligning the pre-tilt angle of the liquid crystal L3
and the angle of the skew light 8. When the thickness
Ht of the transparent pattern 5 and the protective
10 layer 14 and the thickness Lt of the liquid crystal
layer 4 are made smaller or the width W3 of the metal
wire 17 is made smaller than the width Wl of the
transparent pattern 5, the angle G of the skew light 8
increases. However, if the angle 9 is increased, the
15 intensity of the skew light 8 decreases and thus,
conditions of the thickness Lt and the width Wl are
appropriately adjusted by fitting to the effect of
intended viewing angle control.
The skew light 8 is emitted, as described above,
20 via the protruding portion (apex of the section of the
transparent pattern) 5a of the linear pattern 7.
Driving of liquid crystals arranged near the protruding
portion 5a of the linear pattern 7 may be used as a
drive trigger of the liquid crystals of a VA system or
25 ECB system. Driving of the liquid crystals will be
described by using VA liquid crystals.
FIG. 6 is a partial sectional view showing an
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example of the liquid crystal display device 1 when no
drive voltage is applied in the present embodiment. In
FIG. 6, only the left side from the center axis Z of
the sub-pixel is shown to simplify the description.
5 The substrate for liquid crystal display 2
includes the transparent pattern 5, the light-shielding
pattern 6, the third electrode 13 as a transparent
conductive film and the like. The array substrate 3
includes TFT elements (not illustrated), the first
10 electrodes PI to P3 in a comb-like pattern, the second
electrodes CI to C3 in a comb-like pattern and the
like. The liquid crystal display device 1 is formed by
the substrate for liquid crystal display 2 and the
array substrate 3 being bonded together via the liquid
15 crystal layer 4. The first electrodes PI to P3 are
connected to the TFT element to apply a drive voltage
of the liquid crystals LI to L7. The second electrodes
CI to C3 and the third electrode 13 are used as common
electrodes. The second electrodes CI to C3 are a
20 second comb-like pattern disposed below the first
electrodes PI to P3 via the insulating layer 16c. The
second electrodes CI to C3 protrude in a direction
toward an edge of a polygonal sub-pixel from the center
axis Z dividing the polygonal sub-pixel into two
25 portions in the vertical direction more than the
corresponding first electrodes PI to P3.
In FIG. 6, the initial alignment state of the
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liquid crystals LI to L7 when no drive voltage is
applied is illustrated. The liquid crystals Ll to L7
when no drive voltage is applied are aligned almost
perpendicularly to the surface of the substrate for
5 liquid crystal display 2 and the array substrate 3.
However, in contrast to the liquid crystals L2 to L7
above the surface of the color filter 11, the liquid
crystal Ll near the apex of the transparent pattern 5
is aligned with a pre-tilt angle because the liquid
10 crystal Ll is aligned so as to be perpendicular to the
inclination of the protruding portion 5a of the
transparent pattern 5. The first electrodes PI to P3
and the second electrodes CI to C3 are formed as a
comb-like pattern of a transparent conductive film.
15 FIG. 7 is a partial sectional view showing an
example of the liquid crystal display device 1
immediately after the drive voltage is applied. In
FIG. 7, only the left side from the center axis Z of
the sub-pixel is shown to simplify the description.
20 FIG. 7 shows an operation of the liquid crystals
Ll to L7 immediately after the drive voltage is applied
to the first electrodes PI to P3. The liquid crystal
Ll near the protruding portion 5a of the transparent
pattern 5 has an inclination angle and inclines
25 significantly in an arrow al direction fastest among
the liquid crystals Ll to L7 near the surface of the
substrate for liquid crystal display 2 because the
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inter-electrode distance between the first electrode PI
and the third electrode 13 is small. The other liquid
crystals L2 to L7 near the surface of the substrate for
liquid crystal display 2 start to incline in the same
5 direction like propagation triggered by the inclination
of the liquid crystal LI.
FIG. 8 is a partial sectional view showing an
example of the liquid crystal display device 1 when
some time passes after the drive voltage is applied.
10 In FIG. 8, only the left side from the center axis Z of
the sub-pixel is shown to simplify the description.
When some time passes after the drive voltage is
applied to the first electrodes PI to P3, the liquid
crystals LI to L7 incline in a state in accordance with
15 a magnitude of the applied voltage.
FIG. 9 is a partial sectional view showing an
example of an action of the first electrodes PI to P3
and the second electrodes CI to C3 when no drive
voltage is applied (initial alignment state) in the
20 liquid crystal display device 1 according to the
present embodiment.
The first electrodes PI to P3 in a comb-like
pattern and the second electrodes CI to C3 in a comblike
pattern are arranged via the insulating layer 16c.
25 The second electrode CI to C3 and the first electrodes
PI to P3 are shifted in the horizontal direction. In
FIGS. 9 and 10, the second electrodes CI to C3 and the
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first electrodes Pi to P3 are partially overlapped and
the other portions protrude. In the horizontal
direction, the second electrodes CI to C3 are shifted
to the side of the transparent pattern 5 more than the
5 first electrodes PI to P3.
The first electrodes PI to P3 and the second
electrodes CI to C3 in a comb-like pattern are formed
by electrically linking two linear conductors or more
having the width of, for example, 2 urn to 20 urn. A
10 linking portion of linear conductors may be formed for
one side or both sides. The linking portion is
preferably formed in a peripheral portion of a
polygonal sub-pixel and outside an opening. The
interval of a comb-like pattern is in the range of, for
15 example, about 3 um to 100 um and is selected based on
liquid a crystal cell condition and liquid crystal
material. A formation density and pitch of a comb-like
pattern and the electrode width can be changed inside a
sub-pixel or a pixel. Protruding amounts Nl, N2 of the
20 first electrodes PI to P3 and the second electrodes CI
to C3 in the horizontal direction can be adjusted in
various ways by the material of the liquid crystals 4,
the drive condition, the thickness of the liquid
crystal cell, dimensions and the like. The protruding
25 amounts Nl, N2 are sufficient even in a small amount
like any value of, for example, 1 um to 6 um. The
overlapping portion can be used as an auxiliary
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capacity related to liquid crystal driving. The liquid
crystals LI to L3 are aligned almost perpendicularly to
the surface of the array substrate 3. Thus, the number
of teeth of a comb, density, and interval in an opening
5 width direction of a sub-pixel or pixel in the first
electrodes and second electrodes in a comb-like pattern
can appropriately be adjusted in accordance with the
size or purpose of use of the liquid crystal display
device 1.
10 FIG. 10 is a partial sectional view showing an
example of the action of the first electrodes PI to P3
and the second electrodes CI to C3 when the drive
voltage is applied in the liquid crystal display device
1 according to the present embodiment.
15 When the drive voltage is applied to the first
electrodes PI to P3, electric flux lines El to E3 from
the first electrodes PI to P3 to the second electrodes
CI to C3 are generated. The liquid crystals LI to L3
of the liquid crystal layer 4 instantaneously incline
20 in the same direction so as to be perpendicular to the
electric flux lines El to E3. The direction in which
these liquid crystals LI to L3 incline is the same as
the direction in which the liquid crystals incline
described in FIG. 7 and thus, liquid crystals of a sub-
25 pixel or liquid crystals of a whole pixel quickly
incline in the same direction at the same time.
FIG. 11 is a partial plan view showing a first
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example of the first electrode included in the subpixel
.
FIG. 12 is a partial plan view showing a second
example of the first electrode included in the sub-
5 pixel.
In FIGS. 11 and 12, the sub-pixel is formed in a
rectangular shape and the first electrodes PI to P3 in
a comb-like shape are sides of the sub-pixel and
parallel to two parallel sides opposite to each other.
10 FIG. 13 is a partial plan view showing a third
example of the first electrode included in the subpixel
.
A red sub-pixel, a green sub-pixel, and a blue
sub-pixel have a parallelogrammic shape. The red sub-
15 pixel, the green sub-pixel, and the blue sub-pixel are
arranged laterally. Sub-pixels of the same color are
arranged lengthwise.
The first electrodes PI to P6 in a comb-like shape
are parallel to two parallel oblique lines opposite to
20 each other in a sub-pixel in a parallelogrammic shape.
Arrows Fl to F4 indicate the directions in which
the liquid crystals incline after the drive voltage is
applied. After the drive voltage is applied, the
liquid crystals incline in a direction perpendicular to
25 the longitudinal direction of the first electrodes PI
to P6.
FIG. 14 is a partial plan view showing a
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modification of an arrangement of sub-pixels. Thus,
sub-pixels of the same color are arranged laterally.
The red sub-pixel, green sub-pixel, and blue sub-pixel
are arranged lengthwise.
5 The electrode configuration or electrode
arrangement shown in FIG. 6 or 9 may be made to have
line symmetry with respect to the sub-pixel center, as
shown in FIG. 1. By causing the electrode
configuration or electrode arrangement to have line
10 symmetry or point symmetry with respect to the subpixel
center, liquid crystals can be made to incline in
various directions so that a wide viewing angle can be
secured.
In the present embodiment, pixel display TFT and
15 viewing angle control TFT may be included in a pixel or
a sub-pixel. In such a case, as shown in FIGS. 12 and
13, the first electrodes PI to P6 as pixel electrodes
can separately be connected to the pixel display TFT
and viewing angle control TFT. For example, the first
20 electrodes PI, P6 on edge sides of the sub-pixel are
connected to the visual angle control TFT. The
remaining first electrodes P2 to P5 are connected to
the pixel display TFT. The first electrodes PI, P6 and
the first electrodes P2 to P5 are electrically
25 independent. Thus, by using a configuration in which
the first electrodes PI, P6 are connected to the
viewing angle control TFT and the first electrodes P2
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to P5 are connected to the pixel display TFT, the
viewing angle control by the skew light 8 can be
executed independently of the pixel display so that the
effect of the viewing angle control can materially be
5 improved. In the normal pixel display with a wide
viewing angle, a high-quality display with a wide
viewing angle may be achieved by an oblique field
effect from the first electrodes P2 to P5 connected to
the pixel display TFT toward the third electrode 13
10 without, for example, the first electrodes Pi, P6
connected to the viewing angle control TFT being driven
(no drive voltage being applied). In addition, a
streak width of the light-shielding pattern 6 made of a
light-shielding layer such as a black matrix can be
15 made thinner by forming a TFT element from an oxide
semiconductor so that the aperture ratio of the liquid
crystal display device 1 can be improved. In the
present embodiment, it is preferable to apply the TFT
element generated from the oxide semiconductor.
20 If TFT as an active element is formed from the
oxide semiconductor, the aperture ratio of a sub-pixel
or pixel can be improved. As a typical channel
material of TFT from the oxide semiconductor, for
example, a complex metal oxide of indium, gallium, and
25 zinc called IGZO can be used.
A conductive metal oxide that is transparent in
the visible range like ITO can be used as the material
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of the first electrodes PI to P6 and the second
electrodes CI to C6 on the side of the array substrate
3 of the liquid crystal display device 1 according to
the present embodiment. A metal whose electrical
5 conductivity is higher than that of the metal oxide may
also be used as the material of the first electrodes Pi
to P6 and the second electrodes CI to C6. In a
reflection type or transflective type liquid crystal
display device, a thin film of aluminum or aluminum
10 alloy may be used for one or both of the first
electrodes PI to P6 and the second electrodes CI to C6.
The metal wire 17, the first electrodes PI to P6, the
second electrodes CI to C6 and the like connected to
active elements are formed for the substrate 15 via the
15 insulating layers 16a to 16c made of silicon nitride
(SiNx) or silicon oxide (SiOx). The thickness of the
insulating layers 16a to 16c is set depending on the
drive condition of the liquid crystals and selected in
the range of, for example, 100 nm to 600 nm.
20 Incidentally, the technology to form signal lines such
as a gate wire and a source wire by using a single
layer of an aluminum alloy having low contact
properties for ITO as a conductive metal oxide is
disclosed by, for example, Jpn. Pat. Appln. KOKAI
25 Publication No. 2009-105424. Further stacking an
insulating layer above the first electrodes PI to P6 is
preferable because of an effect of mitigating sticking
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(affected by biased or accumulated charges) of liquid
crystals when the liquid crystals is driven.
In the present embodiment, the transparent pattern
5 protruding to the side of the liquid crystal layer 4
5 more than the light-shielding pattern 6 and the color
filters 10 to 12 is formed. Accordingly, the thickness
of the liquid crystal layer 4 below the transparent
pattern 5 and the thickness of the liquid crystal layer
4 below the color filters 10 to 12 are different. The
10 liquid crystal layer 4 below the transparent pattern 5
becomes thinner than the liquid crystal layer 4 below
the color filters 10 to 12. Due to different
thicknesses of the liquid crystal layer 4, the skew
light 8 emitted from a portion of the linear pattern 7
15 may slightly be colored, but this does not cause any
problem in terms of viewing angle control. The skew
light 8 is emitted light close to bright white light
rather than colored light of a green sub-pixel or the
like (light having passed through a color filter) and
20 so is suitable for viewing angle control.
Various technical terms in the present embodiment
will be described below.
A matrix pattern is a light-shielding pattern
disposed around a pixel (picture element) or sub-pixel
25 as the minimum unit of display, on a side of a
polygonal pixel or a polygonal sub-pixel to increase
the contrast of the liquid crystal display. The matrix
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pattern may also be called a black matrix. In the
present embodiment, a matrix pattern on at least two
sides opposite to each other of a polygonal pixel or a
polygonal sub-pixel are configured so that the linear
5 transparent pattern 5 is sandwiched between the centers
of the light-shielding patterns 6 in a plan view. The
light-shielding layer is a light-shielding coated film
obtained by dispersing a light-shielding pigment in a
transparent resin and generally has photosensitivity.
10 The light-shielding pattern 6 is generated by forming a
light-shielding layer by photolithography including
exposure and development as a pattern. The transparent
pattern 5 is generated by forming a transparent resin
or acryl resin as a pattern. The transparent pattern 5
15 may contain a small amount of pigment, ultraviolet
absorber, or infrared absorber. The transparent
pattern 5 is formed from a transparent resin having
high transmittance in the visible range. Either the
light-shielding pattern 6 or the transparent pattern 5
20 may be formed first as the formation order.
A polygonal pixel or a polygonal sub-pixel means a
plan view shape of a picture element or sub-pixel and
means a pixel or sub-pixel of a polygon in which sides
opposite to each other are parallel like a rectangle, a
25 parallelogram and a "<" formed dogleg-shaped polygon.
FIG. 15 is a plan view showing an example of the
relationship between a polygonal sub-pixel and the
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first electrodes PI to P6.
In a "<" formed dogleg-shaped polygonal sub-pixel,
sides are bent. The first electrodes PI to P6 are bent
near a center lengthwise along the sides. Thus,
5 directions Fl to F4 in which liquid crystals incline
are different in four quadrants obtained by dividing
the "<" formed dogleg-shaped polygonal sub-pixel by the
lengthwise center axis and the lateral center axis.
If the emission direction of the skew light 8 in
10 viewing angle control is taken into consideration, the
plane shape of a sub-pixel is preferably the "<" formed
dogleg-shaped polygon shown in FIG. 15 or a combination
of parallelograms shown in FIGS. 13 and 14.
Particularly when characters are displayed in a liquid
15 crystal display screen, visibility of third parties can
be decreased by applying parallelogrammic sub-pixels in
FIGS. 13 and 14 in which the emission direction changes
for each constituent sub-pixel in the character
display. When two active elements are formed for each
20 sub-pixel and first electrodes for display and first
electrodes for viewing angle control are driven by
respective active elements, the contribution of pixel
formation factors decreases slightly. This is because
the skew light 8 can be controlled in this case
25 separately from the display by first electrodes for
viewing angle control. Further in this case,
visibility of the skew light 8 by third parties is
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34
decreased by using first electrodes for viewing angle
control and so a drive voltage signal may be randomized
or the shape/arrangement of the transparent pattern 5
may be randomized.
5 A color layer refers to a coated film of coloring
composition obtained by dispersing organic pigments in
a transparent resin. A color layer formed so as to
overlap with a portion of a light-shielding pattern by
a known photolithography technique is called a color
10 pixel. In the present embodiment, color pixels include
a red sub-pixel, green sub-pixel, and blue sub-pixel.
The effective size of each sub-pixel is approximately
the same as the size of an opening of a matrix pattern.
In the present embodiment, the relative dielectric
15 constant of a color layer is a relatively important
property and is almost uniquely determined by the ratio
(color reproduction as a color filter) of an organic
pigment added as a coloring agent to the transparent
resin and thus, it is difficult to materially change
20 the relative dielectric constant of the color layer.
In other words, the type and content of organic pigment
in the color layer are set based on necessary color
purity as a liquid crystal display device and also the
relative dielectric constant of the color layer is
25 almost determined by the settings. The relative
dielectric constant can be increased to 4 or more by
increasing the ratio of organic pigments and making the
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color layer thinner. The relative dielectric constant
can slightly be increased by using a material of high
refractive index as the transparent resin. The
relative dielectric constant of the color layer using
5 an organic pigment is generally set to the range of 2.9
to 4.5. Values of the relative dielectric constants of
color sub-pixels of different colors may be set so that
their difference is within ±0.3 to avoid color
unevenness and light leakage in the liquid crystal
10 display. If the difference of relative dielectric
constants between color sub-pixels exceeds 0.8 or 1.0
in the liquid crystal display device 1 in a drive
method according to the present embodiment or an FFS
(Fringe-Field Switching) method, color unevenness or
15 light leakage may occur in the liquid crystal display.
The relative dielectric constant of a color sub-pixel
can be reduced to 4.4 or less by the selection of
organic pigment as a coloring agent and the ratio of
pigment and also the selection of the resin as a base
20 material and the material such as a dispersion
material. A zinc halide phthalocyanine green pigment
is preferable to a copper halide phthalocyanine green
pigment as an organic pigment of a green sub-pixel.
The relative dielectric constant of a green sub-pixel
25 can be decreased by adopting the zinc halide
phthalocyanine green pigment as the coloring agent of
the green sub-pixel, which makes it easier to bring the
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relative dielectric constant of a green sub-pixel
closer to the relative dielectric constant of a red
sub-pixel or the relative dielectric constant of a blue
sub-pixel. When the startup of the liquid crystals in
5 liquid crystal driving is fast on the shorter
wavelength side (blue sub-pixel) and slow on the longer
wavelength side (red sub-pixel), the size of the
relative dielectric constant of a color sub-pixel can
be adjusted in the order of the wavelength of light.
10 Conditions that do not interfere with liquid crystal
driving can be obtained by making the value of the
relative dielectric constant of a color filter
constituent member smaller than the value of dielectric
constant anisotropy Ae of the liquid crystals used for
15 the liquid crystal display device 1. For the formation
of the color filter, a photosensitive acryl resin is
generally used. In general, the relative dielectric
constant of a transparent resin such as an acryl resin
is about 2.8. In the present embodiment, the lower
20 limit of the relative dielectric constant of a color
sub-pixel as a dispersed system of organic pigments is
set to about 2.9.
In the present embodiment described above, viewing
angle control of the liquid crystal display device can
25 be realized. In the present embodiment, the liquid
crystal display device can be prevented from becoming
heavy and thick and the aperture ratio can be prevented
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from decreasing so that the viewing angle control can
be executed.
(Second embodiment)
In the present embodiment, examples of various
5 materials of the transparent resin, organic pigments
and the like of the substrate for liquid crystal
display 2 according to the first embodiment described
above will be described.

10 A photosensitive coloring composition used to form
a light-shielding layer or color layer further
contains, in addition to a pigment dispersing element,
a polyfunctional monomer, photosensitive resin or nonphotosensitive
resin, polymerization initiator, solvent
15 and the like. An organic resin with high transparency
used in the present embodiment like a photosensitive
resin or non-photosensitive resin is called a
transparent resin.
The transparent resin includes a thermoplastic
20 resin, thermosetting resin, or photosensitive resin.
As the thermoplastic resin, for example, a butyral
resin, styrene-maleic acid copolymer, chlorinated
polyethylene, chlorinated polypropylene, polyvinyl
chloride, vinyl chloride-vinyl acetate copolymer,
25 polyvinyl acetate, polyurethane resin, polyester resin,
acrylic resin, alkyd resin, polystyrene resin,
polyamide resin, rubber-based resin, cyclized
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rubber-based resin, celluloses, polybutadiene,
polyethylene, polypropylene, polyimide resin or the
like is used. As the thermosetting resin, for example,
an epoxy resin, benzoguanamine resin, rosin modified
5 maleic acid resin, rosin modified fumaric acid resin,
melamine resin, urea resin, phenol resin or the like is
used. A material obtained by allowing a melamine resin
to react with a compound containing an isocyanate group
may be used as the thermosetting resin.
10
For the formation of a light-shielding pattern 6,
a transparent pattern 5, and a color sub-pixel used in
the present embodiment, it is preferable to use a
photosensitive resin composition from which a pattern
15 can be formed by photolithography. Such a transparent
resin is preferably a resin having alkali solubility.
A resin containing a carboxyl group or hydroxyl group
may be used as the alkali soluble resin. As the alkali
soluble resin, for example, an epoxy acrylate resin,
20 novolac resin, polyvinyl phenol resin, acrylic resin,
epoxy resin containing a carboxyl group, urethane resin
containing a carboxyl group or the like is used. Among
others, the epoxy acrylate resin, novolac resin, and
acrylic resin are preferable and the epoxy acrylate
25 resin and novolac resin are particularly preferable.

As a typical transparent resin according to the
39
present embodiment, the following acrylic resins can be
illustrated.
As the acrylic resin, a polymer obtained by using,
for example, as a monomer, (meta)acrylic acid; alkyl
5 (meta)acrylate such as methyl (meta)acrylate, ethyl
(meta)acrylate, propyl (meta)acrylate, butyl
(meta)acrylate, t-butyl (meta)acrylate, benzyl
(meta)acrylate, and lauryl (meta)acrylate;
(meta)acrylate containing a hydroxyl group such as
10 hydroxylethyl (meta)acrylate and hydroxylpropyl
(meta)acrylate; (meta)acrylate containing an ether
group such as ethoxyethyl (meta)acrylate and glycidyl
(meta)acrylate; and alicyclic (meta)acrylate such as
cyclohexyl (meta)acrylate, isobornyl (meta)acrylate,
15 and dicyclopentenyl (meta)acrylate is used.
The above monomers can be used alone or by
combining two or more monomers. As the acrylic resin
according to the present embodiment, a copolymer of
these monomers and a compound that can be copolymerized
20 with these monomers such as styrene, cyclohexyl
maleimide, and phenyl maleimide may be used.
To obtain a resin having photosensitivity,
carboxylic acid having an ethylene unsaturated group
like, for example, (meta)acrylic acid may be
25 copolymerized to allow the obtained copolymer to react
with a compound containing an epoxy group and
unsaturated double bond such as glycidyl methacrylate.
40
Also to obtain a resin having photosensitivity, a
compound containing carboxylic acid such as
(meta)acrylic acid may be added to a polymer of
(meta)acrylate containing an epoxy group such as
5 glycidyl methacrylate or a copolymer of the polymer and
other (meta)acrylate.
<0rganic pigment>
As the red pigment, for example, C. I. Pigment Red
7, 9, 14, 41, 48:1, 48:2, 48:3, 48:4, 81:1, 81:2, 81:3,
10 97, 122, 123, 146, 149, 168, 177, 178, 179, 180, 184,
185, 187, 192, 200, 202, 208, 210, 215, 216, 217, 220,
223, 224, 226, 227, 228, 240, 242, 246, 254, 255, 264,
272, 279 or the like may be used.
As the yellow pigment, for example, C. I. Pigment
15 Yellow 1, 2, 3, 4, 5, 6, 10, 12, 13, 14, 15, 16, 17,
18, 20, 24, 31, 32, 34, 35, 35:1, 36, 36:1, 37, 37:1,
40, 42, 43, 53, 55, 60, 61, 62, 63, 65, 73, 74, 77, 81,
83, 86, 93, 94, 95, 97, 98, 100, 101, 104, 106, 108,
109, 110, 113, 114, 115, 116, 117, 118, 119, 120, 123,
20 125, 126, 127, 128, 129, 137, 138, 139, 144, 146, 147,
148, 150, 151, 152, 153, 154, 155, 156, 161, 162, 164,
166, 167, 168, 169, 170, 171, 172, 173, 174, 175, 176,
177, 179, 180, 181, 182, 185, 187, 188, 193, 194, 199,
213, 214 or the like may be used.
25 As the blue pigment, for example, C. I. Pigment
Blue 15, 15:1, 15:2, 15:3, 15:4, 15:6, 16, 22, 60, 64,
80 or the like may be used and among others, C. I.
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Pigment Blue 15:6 is preferable.
As the purple pigment, for example, C. I. Pigment
Violet 1, 19, 23, 27, 29, 30, 32, 37, 40, 42, 50 or the
like may be used and among others, C. I. Pigment Violet
5 23 is preferable.
As the green pigment, for example, C. I. Pigment
Green 1, 2, 4, 7, 8, 10, 13, 14, 15, 17, 18, 19, 26,
36, 45, 48, 50, 51, 54, 55, 58 or the like may be used
and among others, C. I. Pigment Green 58 as a zinc
10 halide phthalocyanine green pigment is preferable.
In the description of the pigment type of C. I.
Pigment below, simple abbreviations like PB (Pigment
Blue), PV (Pigment Violet), PR (Pigment Red), PY
(Pigment Yellow), and PG (Pigment Green) will be used.
15
A light-shielding coloring material contained in a
light-shielding layer or matrix pattern realizes a
light-shielding function by having absorption
characteristics in the visible light wavelength range.
20 In the present embodiment, for example, an organic
pigment, inorganic pigment, dye or the like is used as
the light-shielding coloring material. As the
inorganic pigment, for example, carbon black, titanium
oxide or the like is used. As the dye, for example, an
25 azo-based dye, anthraquinone-based dye, phthalocyaninebased
dye, quinoneimine-based dye, quinoline-based dye,
nitro-based dye, carbonyl-based dye, methine-based dye
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or the like is used. Regarding the organic pigment,
the organic pigments described above may be used. One
type of light-shielding component may be used or two
types or more of light-shielding components in any
5 combination and ratio may be used. Moreover, high
volume resistivity may be achieved by resin coating on
the surface of these coloring materials. Conversely,
low volume resistivity may be achieved by increasing
the ratio of coloring material content to the base
10 material of the resin to provide slight conductivity.
The volume resistance of such light-shielding materials
is in the range of about 1x10^ to lxlO^^Q"cm, which is
a level that does not affect the resistance of a
transparent conductive film. Similarly, the relative
15 dielectric constant of a light-shielding layer can be
adjusted to the range of about 3 to 20 by the selection
of coloring material or the ratio of content. The
relative dielectric constants of the light-shielding
pattern 6, the transparent pattern 5, color layers
20 (color filters 10 to 12), and a protective layer 14 can
be adjusted by based on at least one of design
conditions of a liquid crystal display device 1 and
drive conditions of the liquid crystal.

25 Using a macromolecular dispersant as a pigment
dispersant is preferable due to superior dispersion
stability over time. As the macromolecular dispersant,
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for example, a urethane-based dispersant,
polyethyleneimine-based dispersant, polyoxyethylene
alkylether-based dispersant, polyoxyethylene
glycoldiester-based dispersant, sorbitan aliphatic
5 ester-based dispersant, aliphatic modified polyesterbased
dispersant or the like can be used.
Particularly, it is preferable to use a dispersant
containing a graft copolymer containing nitrogen atoms
for a light-shielding photosensitive resin composition
10 containing a large amount of pigment from the viewpoint
of development properties. One type of dispersant may
be used or two types or more of dispersants in any
combination and ratio may be used.
As the dispersing agent, for example, a coloring
15 matter derivative or the like can be used. As the
coloring matter derivative, for example, an aso-based,
phthalocyanine-based, quinacridone-based,
benzimidazolone-based, quinophthalone-based,
isoindolynone-based, dioxazine-based, anthraquinone-
20 based, indanthrene-based, perylene-based, perynonebased,
or diketopyrrolopyrrole-based derivative may be
used and particularly, the quinophthalone-based
derivative is preferable.
As the substituent group of a coloring matter
25 derivative, for example, the sulfonic group,
sulfonamide group and quaternary salt thereof,
phthalimide methyl group, dialkylamino alkyl group,
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hydroxyl group, carboxyl group, amide group or the like
is contained directly in a pigment skeleton or a
substance bonded via the alkyl group, aryl group,
heterocyclic group or the like is contained. Among
5 others, the sulfonic group is preferable. In addition,
among these substituent groups, a plurality of
substituent groups may be substituted for a pigment
skeleton.
Concrete examples of the coloring matter
10 derivative include a sulfonic acid derivative of
phthalocyanine, sulfonic acid derivative of
quinophthalone, sulfonic acid derivative of
anthraquinone, sulfonic acid derivative of
quinacridone, sulfonic acid derivative of
15 diketopyrrolopyrrole, and sulfonic acid derivative of
dioxazine.
One type of the above dispersing agent or coloring
matter derivative may be used or two types or more of
the above dispersing agents or coloring matter
20 derivatives in any combination and ratio may be used.
(Third embodiment)
In the present embodiment, an example of the
method for manufacturing a substrate for liquid crystal
display 2A shown in FIG. 16 will be described. FIG. 16
25 is illustrated by setting a substrate 9 of the
substrate for liquid crystal display 2A as the upper
side and a protective layer 14 as the lower side.
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(Dispersion liquid for the light-shielding pattern
6 formation)
20 mass parts of the carbon pigment #47, 8.3 mass
5 parts of a macromolecular dispersant, 1.0 mass part of
a copper phthalocyanine derivative, and 71 mass parts
of propylene glycol monomethyl ether acetate are
stirred by a bead mill dispersion machine to generate a
carbon black dispersion liquid.
10 (Photoresist for forming the light-shielding
pattern 6)
A resist for forming the light-shielding pattern 6
as the material for a light-shielding layer is
generated by using the following materials:
15 Carbon black dispersion liquid: Pigment #47
Transparent resin (Solid content: 56.1% by mass)
Photopolymeric monomer
Initiator
Solvent: Propylene glycol monomethyl ether
20 acetate, ethyl-3-ethoxypropionate
Leveling agent
The resist for forming the light-shielding pattern
6 (pigment concentration in solid content: about 20%)
is generated by mixing and stirring the above materials
25 in the following composition ratio:
Carbon black dispersion liquid 3.0 mass parts
Transparent resin 1.4 mass parts
:
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Photopolymeric monomer 0.4 mass parts |
First photopolymerization initiator 0.67 mass I
parts I
Second photopolymerization initiator 0.17 mass I
5 parts I
Propylene glycol monomethyl ether acetate 14 mass I
parts
Ethyl-3-ethoxypropionate 5.0 mass parts
Leveling agent 1.5 mass parts
10 (Light-shielding pattern formation conditions)
A resist for forming the light-shielding pattern 6
is spin-coated on the transparent substrate 9 as nonalkali
glass and dried to form a coated film of 1.5 urn
in thickness. After the coated film is dried at 100°C
15 for 3 min, irradiation of 200 mJ/cm^ is performed by
using a photo mask for exposure and a super-high
pressure mercury lamp as a light source.
Next, the coated film is developed for 60 sec in a
2.5% sodium carbonate solution, washed well after the
20 development, and dried before being treated with heat
at 230°C for 60 min for hardening to form the lightshielding
pattern 6. The streak width of the lightshielding
pattern 6 shown in FIG. 16 is about 8 urn on
one side and the light-shielding pattern 6 is formed on
25 two sides of a rectangular pixel.
:
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47

(Resin A synthesis)
686 mass parts of propylene glycol monomethyl
ether acetate, 332 mass parts of glycidyl methacrylate,
5 and 6.6 mass parts of azobisisobutyronitrile are added
to a separable flask and the flask is heated at 80°C
for 6 hours under a nitrogen atmosphere to generate a
resin solution.
Next, 168 mass parts of acrylic acid, 0.05 mass
10 parts of methoquinone, and 0.5 mass parts of
triphenylphosphine are added to the obtained resin
solution and the resin solution is heated at 100°C for
24 hours while the air is blown into the flask to
purify the acrylic acid added resin solution.
15 Further, 186 mass parts of tetrahydrophthalic
anhydride to the obtained acrylic acid added resin
solution and the solution is heated at 70°C for
10 hours to generate a resin A solution.
(Preparation of a photosensitive resin liquid AA)
20 The negative type photosensitive resin liquid AA
is generated with the following composition:
Resin A 200 mass parts
Photopolymeric monomer
Dipentaerythritol hexaacrylate 100 mass parts
25 Photopolymerization initiator 100 mass parts
Solvent (propylene glycol monomethyl ether
acetate) 380 mass parts
;
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The photosensitive resin liquid AA and a photo
mask having a transparent pattern 5 (opening) are used
to form the transparent pattern 5 of the width 18 um
between the light-shielding patterns 6 of the width
5 8 p shown in FIG. 1 on the transparent substrate 9 by
a publicly known photolithography method so that a
linear pattern 7 of the width 34 um and a matrix
pattern are generated. The height (thickness) of the
transparent pattern 5 is set to, for example, 3.2 um.
10
A transparent conductive film that is transparent
in the visible range like ITO (thin film of metallic
oxide indium/tin) is formed as a third electrode 13 to
15 a thickness of 0.14 um so as to cover the entire
surface of the linear pattern 7 and the matrix pattern
by using a sputtering device.

(Resin B synthesis)
20 800 parts of cyclohexane are placed in a reaction
vessel and the vessel is heated while a nitrogen gas is
injected thereinto and a mixture of monomers and a
thermal polymerization initiator described below is
dropped to allow a polymerization reaction.
25 Styrene 60 mass parts
Methacrylic acid 60 mass parts
Methyl methacrylate 65 mass parts
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49
Butyl methacrylate 65 mass parts
Thermal polymerization initiator 10 mass parts
Chain transfer agent 3 mass parts
After sufficient heating after the mixture is
5 dropped, a material produced by dissolving 2.0 mass
parts of the thermal polymerization initiator in 50
mass parts of cyclohexane is added and further the
reaction is continued to generate an acrylic resin
solution.
10 The acrylic resin solution is prepared by adding
cyclohexane to the resin solution so that the solid
content becomes 20% by mass to generate the resin B.
The average molecular weight by weight of acrylic
resin is assumed to be about 10000.
15 (Resin coating liquid BB)
After a mixture of the following composition is
stirred and mixed uniformly, the mixture is dispersed
in a sand mill by using a glass bead whose diameter is
1 mm for 5 hours and then filtered by using a filter of
20 1 urn to generate the resin coating liquid BB.
Resin B 150 mass parts
Polyfunctional polymeric monomer 20 mass parts
Optical initiator 16 mass parts
Cyclohexane 250 mass parts
25 The protective layer 14 is coated so as to cover
the entire surface of the third electrode 13 by using
the resin coating liquid BB and dried. Next, a photo
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50
mask having a light-shielding pattern in the same shape
as that of the transparent pattern 5 is used for
exposure/development to remove the protective layer 14
in the upper portion of the transparent pattern 5.
5 Then, the protective layer 14 is hardened by total
surface re-exposure and heat treatment to form the
substrate for liquid crystal display 2A. The film
thickness of the protective layer 14 after hardening is
2.0 urn in the center of a polygonal sub-pixel. The
10 difference between the height of the surface of the
third electrode 13 of a polygonal sub-pixel at the apex
of the linear pattern 7 and the height of the surface
of the protective layer 14 in the center of the subpixel
is set to be about 1.2 urn.
15 The substrate for liquid crystal display 2A can be
applied to a monochrome liquid crystal display device,
but can also make a color display by using, for
example, individual light emitting LED elements such as
red, green, and blue as a backlight and applying the
20 field sequential method.
FIG. 17 is a sectional view showing an example of
a configuration of an edge light type liquid crystal
display device.
In FIG. 17, a case when a liquid crystal display
25 device 18 includes the substrate for liquid crystal
display 2A is illustrated, but a case when a substrate
for liquid crystal display 2 is included is similar.
51
The liquid crystal display device 18 is a
transflective type liquid crystal display device using
a reflecting-polarizing plate 19.
As described in the first embodiment, a substrate
5 for liquid crystal display 20 includes an array
substrate 3 on which active elements (TFT) are formed.
The array substrate 3 includes, for example, first and
second electrodes in a comb-like shape. The substrate
for liquid crystal display 2A and the array substrate 3
10 are arranged opposite to each other and provided
| together via the liquid crystal layer 4 therebetween.
| The liquid crystal layer 4 has negative dielectric
constant anisotropy. An optical compensation layer
(phase difference plate) 21 and a polarizing plate 22
15 are arranged on the surface (back side) of the
substrate for liquid crystal display 2A on the side
opposite to the liquid crystal layer 4. Also, a
polarizing plate 23, a light diffusion layer 24, the
reflecting-polarizing plate 19, an optical compensation
20 layer (phase difference plate) 25, a prism sheet 26, a
light diffusion layer 27, a light guiding plate 28, and
a light reflection plate 29 are successively disposed
on the surface (back side) of the array substrate 3
opposite to the liquid crystal layer 4. A light source
25 30 like, for example, an LED is mounted on the light
guiding plate 28. As the polarizing plates 22, 23, for
example, the cross Nicole arrangement is used.
52
RGB individual light emitting elements are
desirable as the light source 30, but a pseudo-white
LED may also be used when individual RGB light emitting
elements are not controlled by the field sequential
5 method. In addition, a cold cathode ray tube or
fluorescent lamp may also be used as the light source
30. When RGB individual light emitting elements are
used as the light source 30, each light emitting
intensity can individually be adjusted for each color,
10 sub-pixel, and pixel so that the optimal color display
can be made and the color display can be made by time
division driving synchronized with the liquid crystals
without using any color filter. In addition, the RGB
individual light emitting elements can be applied to
15 the stereoscopic display. In the liquid crystal
display device 18, the local dimming method as a
technology to improve the contrast by adjusting
brightness of the backlight in each portion of the
display screen may be applied. The technique of local
20 dimming is easier to apply to an LED light source. In
the present embodiment, improved image quality can be
obtained by combining the use of a normal display
region and a dynamic display region.
When the color display is made by individual light
25 emission, a high-quality display can be made with fine
control by a direct backlight system in which LED
elements are arranged all over the back side (back side
i
(
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53
of the array substrate) of the liquid crystal display
device rather than an edge light system as shown in
FIG. 17.
Incidentally, the polygonal sub-pixel of a liquid
5 crystal display device according to the present
embodiment can be divided into regions (two or four
regions dividing the sub-pixel) having line symmetry or
point symmetry with respect to the sub-pixel center on
a plane. In the present embodiment, individual TFT
| 10 elements may be allocated to two or four regions having
| line symmetry or point symmetry in the sub-pixel.
| Then, by using the drive method by which different
voltages are applied to each of the TFT elements in the
sub-pixel, visual angle adjustments and a stereoscopic
15 display can be made efficiently.
(Fourth embodiment)
In the present embodiment, an example of the
method for manufacturing a substrate for liquid crystal
display 2 shown in FIG. 2 will be described. FIG. 2 is
20 illustrated by setting a substrate 9 of the
manufactured substrate for liquid crystal display 2 as
the upper side and a protective layer 14 as the lower
side.
In the present embodiment, the manufacturing
25 process until a linear pattern 7 and a third electrode
13 are formed on the substrate 9 is the same as the
case described in the third embodiment.
54
In the present embodiment, various color filters
such as the red color filter 10, the green color filter
11, and the blue color filter 12 are successivelyformed
by using a coloring dispersion liquid described
5 later and a color resist of the composition shown in
Table 1 above the substrate on which up to the third
electrode 13 is formed.
55
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56

(Dispersion liquid for color layer formation)
For example, the following pigments are used as
organic pigments dispersed to the color layer.
5 Red pigment: C. I. Pigment Red 254, C. I. Pigment
Red 177
Green pigment: C. I. Pigment Green 58, C. I.
Pigment Yellow 150
j Blue pigment: C. I. Pigment Blue 15, C. I. Pigment
10 Violet 23
By using the above pigments, the dispersion liquid
of each color of red, green, and blue is generated.
(Red dispersion liquid)
Red pigment: C. I. Pigment Red 254 18 mass parts
15 Red pigment: C. I. Pigment Red 177 2 mass parts
Acrylic varnish (solid content: 20% by mass) 108
mass parts
After a mixture of the above composition is
stirred uniformly, the mixture is dispersed in a sand
20 mill by using a glass bead for 5 hours and then
filtered by using a filter of 5 urn to generate a red
dispersion liquid.
(Green dispersion liquid)
Green pigment: C. I. Pigment Green 58 16 mass
25 parts
Green pigment: C. I. Pigment Yellow 150 8 mass
parts
ii
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57
Acrylic varnish (solid content: 20% by mass) 102
mass parts
A green dispersion liquid is generated by applying
the generation method for a red dispersion liquid to a
5 mixture of the above composition.
(Blue dispersion liquid)
Blue pigment: C. I. Pigment Blue 15 50 mass parts
Blue pigment: C. I. Pigment Violet 23 2 mass
parts
10 Dispersant 6 mass parts
Acrylic varnish (solid content: 20% by mass) 200
i mass parts
A blue dispersion liquid is generated by applying
the generation method for a red dispersion liquid to a
15 mixture of the above composition.

It is assumed that the thickness of each color
pixel is 2 urn after exposure/development and hardening.
20 A photo mask of, for example, a gray tone with low
transmittance is used for exposure to form a pigment
layer so that the color layer on the light-shielding
pattern 6 in a portion of the linear pattern 7 should
not become too thick.
25 Next, the viscosity of a resin coating liquid BB
used for the formation of the protective layer 14 is
controlled and the resin coating liquid BB is coated
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58
and hardened to a thickness of, for example, 0.5 urn to
generate the substrate for liquid crystal display 2.
The difference in height from the surface of the apex
of the linear pattern 7 to the surface of the
5 protective layer 14 in the pixel center is assumed to
be about 0.6 urn. Accordingly, as shown in the partial
plan view of FIG. 3, the red color filter 10, the green
! color filter 11, the blue color filter 12, a
j transparent pattern 5, and the light-shielding pattern
10 6 are formed.
(Fifth embodiment)
In the present embodiment, actions of viewing
angle control of a liquid crystal display device 1 or a
liquid crystal display device 18 described in each of
15 the above embodiments will be described. In the
present embodiment, the description will be provided
about the liquid crystal display device 1 including a
substrate for liquid crystal display 2 shown in FIG. 1,
but the description is similar about the liquid crystal
20 display device 1 or the liquid crystal display device
18 including a substrate for liquid crystal display 2A.
The liquid crystal display device 1 has a
configuration in which the substrate for liquid crystal
display 2 and an array substrate 3 on which active
25 elements as TFT are formed are provided together via a
liquid crystal layer 4. The liquid crystal layer 4 has
a vertical alignment film formed in advance on the
59
front side of both of the substrate for liquid crystal
display 2 and the array substrate 3. First electrodes
PI to P6 of the array substrate 3 form a comb-like
pattern. An insulating layer 16c is formed between the
5 first electrodes PI to P6 and second electrodes CI to
C6 as common electrodes. The second electrodes CI to
C6 protrude in the direction toward a transparent
pattern 5 from the first electrodes PI to P6 in the
horizontal direction. As shown in FIGS. 11 to 13, and
10 FIG. 15, the electrode pattern of the first electrodes
PI to P6 and the second electrodes CI to C6 has line
symmetry with respect to the plane center of a
polygonal sub-pixel.
As shown in FIG. 1, a metal wire 17 as a signal
15 line of TFT is disposed below the transparent pattern
5. Thus, light from the backlight does not enter the
eye of an observer who looks straight at the liquid
crystal display device 1. Though omitted in FIG. 1, a
backlight unit is disposed, for example, below on the
20 side of the array substrate 3 of the liquid crystal
display device in FIG. 1.
FIG. 1 shows a state in which no drive voltage of
liquid crystals LI to L14 is applied and a color filter
(green color filter 11) unit makes a "black display".
25 However, the liquid crystal L3 in an inclined portion
(protruding portion 5a) of a linear pattern 7 has an
inclination with respect to skew light 8 and thus, the
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60
skew light 8 is emitted from the transparent pattern 5
to prevent visual recognition of "black display" in the
eye of a third party.
FIG. 18 is a partial sectional view showing an
5 example of the liquid crystal display device 1 in
halftone display after the drive voltage is applied.
j FIG. 18 illustrates a state in which the drive voltage
is applied to the liquid crystal display device 1 in
FIG. 1.
•
10 An observer can visually recognize halftone green
light from the display unit as the green color filter
11. The skew light 8 as intensive white light is
emitted from the transparent pattern 5. The skew light
8 prevents a third party from visually recognizing
15 light from the green color filter 11. Because the
electrode distance between the third electrode 13 at
the apex of the transparent pattern 5 and the first
electrode PI is small, the liquid crystals LI to L3
located at the position incline significantly when the
20 drive voltage is applied. Thus, the skew light 8 as
intensive white light is emitted from the transparent
pattern 5.
Accordingly, viewing angle control can be executed
without making the liquid crystal display device 1
25 thicker and further without decreasing aperture ratio
so that visual recognition by third parties other than
the observer can be prevented.
J5
61
(Sixth embodiment)
In the present embodiment, a modification of a
liquid crystal display device 1 or a liquid crystal
display device 18 described in each of the above
5 embodiments will be described. In the present
embodiment, the description will be provided about a
j modification of the liquid crystal display device 1
! including a substrate for liquid crystal display 2
shown in FIG. 1, but the liquid crystal display device
10 1 or the liquid crystal display device 18 including a
substrate for liquid crystal display 2A can similarly
be modified.
The description will be provided below based on
FIG. 19 and FIG. 13.
15 In FIG. 13, the illustration of TFT and a metal
wire is omitted. FIG. 13 shows an arrangement
relationship between a comb-like electrode pattern
formed by first electrodes Pi to P6 and color filters
(sub-pixel opening) on a plane. In FIG. 13, the plane
20 of color filters is assumed to be a parallelogram.
FIG. 19 is a partial sectional view showing an
example of a liquid crystal display device according to
the present embodiment.
A liquid crystal display device 31 includes a
25 substrate for liquid crystal display 2B. A lightshielding
portion (light-shielding protrusion) 32 is
formed in the center portion of a transparent pattern 5
( Q
1 62
of the substrate for liquid crystal display 2B. The
light-shielding portion 32 is formed by using the same
material as that of a light-shielding pattern 6, for
example, before the transparent pattern 5 is formed.
| 5 The light-shielding portion 32 is included in the
center and in the linear longitudinal direction of the
transparent pattern 5 on a plane. With the formation
of the light-shielding portion 32, skew light 8 emitted
from the transparent pattern 5 is made harder from the
10 eye of an observer to visually recognize.
As shown in FIG. 13, the first electrodes PI, P6
of an array substrate 3 are electrically connected to
each other and further driven by other TFT than TFT
that drives the other first electrodes P2 to P5. In
15 other words, the first electrodes PI, P6 shown in
FIG. 19 are driven as electrodes for viewing angle
control and the other first electrodes P2 to P5 are
driven as electrodes for display.
In the present embodiment, the drive voltage for
20 viewing angle control can be applied to the first
electrodes PI, P6 independently and thus, excellent
viewing angle control can be exercised.
Also by including the light-shielding portion 32
in the center of the transparent pattern 5, an
25 excellent image display can be provided to the
observer.
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63
(Seventh embodiment)
In the present embodiment, a configuration to
drive a liquid crystals 4 at low voltage in each of the
above embodiments will be described.
5 FIG. 20 is a partial sectional view showing a
first example of the configuration to drive the liquid
crystals 4 at low voltage in a liquid crystal display
device according to the present embodiment.
In FIG. 20, a side face P7A of the section of a
10 first electrode P7 on the side of a protruding portion
Q of a second electrode C7 has an angle Y smaller than
90°. By providing tapering to the side face P7A of the
first electrode P7 in this manner, the direction in
which liquid crystal molecules L15 incline can be
15 decided so that responsiveness can be improved, low
gradations can be enhanced, and the liquid crystals 4
can be driven at low voltage.
Further, in FIG. 20, an insulating layer 16c
formed above the protruding portion Q of the second
20 electrode C7 is etched. By making the insulating layer
16c above the protruding portion Q of the second
electrode C7 thinner in this manner, the direction in
which liquid crystal molecules L16 above the protruding
portion Q incline can be decided so that responsiveness
25 can be improved, low gradations can be enhanced, and
the liquid crystal 4 can be driven at low voltage.
FIG. 21 is a partial sectional view showing a
s
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64
second example of a configuration to drive the liquid
crystals 4 at low voltage in the liquid crystal display
| device according to the present embodiment.
! In FIG. 21, a pre-tilt angle V is provided to
5 liquid crystal molecules L17 in initial vertical
alignment. Accordingly, the direction in which the
liquid crystal molecules L17 above the protruding
portion Q incline can be decided so that responsiveness
can be improved, low gradations can be enhanced, and
10 the liquid crystals 4 can be driven at low voltage.
Only by providing the pre-tilt angle V of about 0.1° to
1° from the vertical direction to the liquid crystal
molecules L17, the liquid crystal molecules L17 are
more likely to incline at low voltage.
15 Also by making the thickness of the first
electrode P7 thicker, the direction in which the liquid
crystal molecules on the protruding portion Q fall can
be decided so that responsiveness can be improved, low
gradations can be enhanced, and the liquid crystal 4
20 can be driven at low voltage.
In each of the above embodiments, an alignment
maintenance layer may be formed on the inner surface of
a liquid crystal panel after a liquid crystal cell
formation by adding photopolymeric acrylate or the like
25 to the liquid crystal and combining the use of exposure
and the applied voltage for the purpose of enhancing
i
the halftone of the liquid crystals. t
65
Also in each of the above embodiments, an
alignment maintenance layer providing a slight
inclination angle to the liquid crystals for each of
two or four liquid crystal domains in each sub-pixel
5 may be formed by forming a coated film of a
photosensitive polymeric liquid crystal or a coated
film of photosensitive polyorganosiloxane or the like
on both sides or one side of the inner surface of a
liquid crystal panel, forming the liquid crystal cell,
10 and combining the use of exposure and the applied
voltage.
In each of the above embodiments, pixels may
include red color filters, green color filters, blue
color filters, and color filters of the other color
15 like, for example, a transparency or complementary
color.

c
66
We Claim:
1. A substrate for liquid crystal display,
comprising:
a polygonal pixel or a polygonal sub-pixel having
5 parallel sides opposite to each other in a plane shape;
and
linear patterns included on the parallel sides
opposite to each other of the polygonal pixel or the
polygonal sub-pixel to allow skew light to pass
10 therethrough.
2. The substrate for liquid crystal display
according to claim 1, wherein each linear pattern has a
configuration in which a linear transparent pattern is
sandwiched between linear light-shielding patterns in
15 the plane shape.
3. The substrate for liquid crystal display
according to claim 2, further comprising:
light-shielding portions in each center and in
each linear longitudinal direction of the transparent
20 patterns in the plane shape.
4. The substrate for liquid crystal display
according to claim 1, further comprising:
a transparent conductive film formed above the
linear patterns.
25 5. The substrate for liquid crystal display
according to claim 1, comprising:
a transparent substrate comprising the linear
patterns formed above one surface thereof;
a transparent conductive film stacked above the [
surface of the transparent substrate above which the
linear patterns are formed; and
5 color filters of polygonal pixels or polygonal
sub-pixels including the polygonal pixel or the
polygonal sub-pixel formed above the transparent
i
conductive film.
6. The substrate for liquid crystal display
10 according to claim 5, wherein at least two of a red
color filter, a green color filter, and a blue color
filter are used as the color filters.
7. The substrate for liquid crystal display
according to claim 1, wherein plane shapes of the
15 polygonal pixels or the polygonal sub-pixels are one of
a rectangle, a parallelogram, and a polygon in a "<"
formed dogleg-shape.
8. The substrate for liquid crystal display
according to claim 1, characterized in that portions
20 where the transparent patterns are formed are thicker
than the other portions.
9. A liquid crystal display device, comprising:
a substrate for liquid crystal display including a
polygonal pixel or a polygonal sub-pixel having
25 parallel sides opposite to each other in a plane shape
and linear patterns included on the parallel sides
opposite to each other of the polygonal pixel or the
68
polygonal sub-pixel to allow skew light to pass
therethrough; and
an array substrate opposite to the substrate for
liquid crystal display via a liquid crystal layer and
5 including an active element to drive liquid crystals of
the liquid crystal layer.
10. The liquid crystal display device according
to claim 9, wherein the array substrate includes a
first electrode and a second electrode to which
i
i
10 different potentials are applied to drive the liquid
crystals for the polygonal pixels or the polygonal subpixels.
11. The liquid crystal display device according
to claim 10, wherein
15 the first electrode has a first comb-like pattern
connected to the active element for driving the liquid
crystals, and
the second electrode has a second comb-like
pattern disposed below the first electrode via an
20 insulating layer and arranged in a position in a
horizontal direction protruding from an edge of the
first electrode in a direction opposite to a center
axis dividing the polygonal pixel or the polygonal subpixel
into two portions in a vertical direction.
25 12. The liquid crystal display device according
to claim 10, wherein
two or more active elements including the active
69
element are included in the polygonal pixel or the
polygonal sub-pixel, and
the two or more active elements included in the
polygonal pixel or the polygonal sub-pixel are
5 respectively connected to two or more portions that are
electrically independent in the first electrode for the
polygonal pixel or the polygonal sub-pixel.
13. The liquid crystal display device according
to claim 10, wherein the first electrode and the second
10 electrode are formed from conductive metal oxide that
is transparent in a visible range.
14. The liquid crystal display device according
to claim 9, wherein the liquid crystals has negative
dielectric constant anisotropy.