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Description
Title of Invention
RECEIVING COIL, RECEPTION APPARATUS AND NON-CONTACT POWER
5 TRANSMISSION SYSTEM
Technical Field
[0001]
The present disclosure relates to a receiving coil to which power is
10 transmitted from an electromagnetically coupled transmitting coil, a reception
apparatus including the receiving coil, and a non-contact power transmission system
using the receiving apparatus.
Background Art
15 [0002]
In recent years, non-contact power transmission systems that transmit power
in a non-contact manner by using a transmitting coil and a receiving coil have been
proposed (see, for example, Patent Literature 1).
[0003]
20 If a non-contact power transmission transmits power using a transmitting
coil in a spiral shape and also a receiving coil in a spiral shape, the receiving coil in a
reception apparatus is greatly affected by metal (used, for example, in the cabinet or
circuit) in the apparatus and the Q value is significantly degraded. The Q value is
an index indicating the relationship between retention and loss of energy or the
25 strength of resonance of a resonant circuit.
[0004]
For the purpose of preventing the influence of the metal, a magnetic sheet is
affixed to the transmitting coil and receiving coil in a spiral shape. The magnetic
sheet needs a certain thickness to prevent the influence of metal inside the apparatus.
30 In addition, a magnetic sheet far larger than the coil is needed to completely prevent
the influence of metal inside the apparatus. The magnetic sheet is generally made
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%
of ferrite (sintered body). Thus, to create a magnetic sheet thinly, a ferrite sheet is
thinly created and stacked with a thin resin sheet thereon and thereunder before being
finely cut to form the magnetic sheet, resulting in a very high price. Because the
magnetic sheet of ferrite is, as described above, fitted to the coil, the magnetic sheet
5 has a large area and varies in thickness or the like greatly so that variations of the
constant of the coil resulting from variations in thickness or the like chiefly cause
degradation of the Q value.
[0005]
When power is transmitted in a non-contact manner, the power transmission
10 efficiency (also called the "inter-coil efficiency") (rirf) is theoretically uniquely
determined from the coupling coefficient k as a degree of coupling between a
transmitting coil and a receiving coil and the Q value (Qi) of the transmitting coil
and the Q value (Ch) of the receiving coil at no load. Formulas to determine the
inter-coil efficiency (rjrf) are shown in Formulas (1) to (3).
15 [Mathl]
S2
* (l+Vi+s2)2
Formula (1)
[Math 2]
S = kQ
20 ^
Formula (2)
[Math 3]
25 Formula (3)
As shown above, the inter-coil efficiency (rirf) of Formula (1) is determined
by the value of S=k*V(Qi*Q2) in Formula (2).
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[0006]
If a large value is obtained as the coupling coefficient k between the
transmitting coil and the receiving coil, that is, in the case of electromagnetic
induction, power can still be transmitted even if the transmitting coil and the
5 receiving coil have almost the same size as the diameters of winding of the
transmitting coil and the receiving coil and the Q values (Qi, Q2) are small.
However, the inter-coil efficiency (rjrf) in the case of electromagnetic induction
depends on the coupling coefficient k and thus, the accuracy of position between the
transmitting coil and the receiving coil is very important and misregistration is not
10 permitted. Thus, when charged in the case of electromagnetic induction, the
transmitting coil and the receiving coil is in a one-to-one correspondence. If an
electronic device having a high rate of using metal such as a mobile phone terminal
or a digital camera is placed above a transmitting coil in a spiral shape, the Q value
of the receiving coil contained in the electronic device is significantly degraded so
15 that it is necessary to compensate for the degraded portion with the coupling
coefficient k.
[0007]
On the other hand, a method, as an electromagnetic resonance method, of
transmitting power to a plurality of electronic devices and also freely arranging the
20 receiving coil with respect to the transmitting coil by decreasing the coupling
coefficient k between the transmitting coil and the receiving coil to increase the Q
value as a resonator is proposed.
Citation List
25 Patent Literature
[0008]
Patent Literature 1: Japanese Patent No. 4413236 (Japanese
Patent Application Laid-Open No. 2008-206231)
30 Summary of Invention
Technical Problem
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[0009]
However, if a receiving coil contained in an electronic device having a high
rate of using metal such as a mobile phone terminal or a digital camera is placed
above a transmitting coil in a flat spiral shape, the Q value (Qi) of the transmitting
5 coil and the Q value (Q2) of the receiving coil are degraded so that power can no
longer be transmitted. Therefore, uses thereof have been limited to those that are
not affected by metal in an electronic device.
[0010]
To increase the degree of freedom of arrangement with respect to a
10 transmitting coil, a receiving coil mounted in an electronic device is made smaller
than the transmitting coil, has the Q value of about 50, which is not large, and is
degraded, which makes it difficult to realize a non-contact power transmission
system that enables excellent power transmission.
[0011]
15 The present disclosure is developed in view of the above circumstances and
increases the Q value of a receiving coil used in a reception apparatus and also
decreases the degradation of the Q value of the receiving coil when put inside a
cabinet.
20 Solution to Problem
[0012]
A receiving coil according to the present disclosure includes a core having a
magnetic body, a coil portion in which a wire is wound around the core and which is
electromagnetically coupled to an external coil to transmit power, and a non-
25 magnetic body arranged at a predetermined distance from a side face of the coil
portion.
As an example, the non-magnetic body has a thickness of 0.3 mm or more.
In addition, a resin portion containing the core having the magnetic portion and the
coil portion is included and the non-magnetic body is arranged on a side face of the
30 resin portion. The core has an H-type shape.
[0013]
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A reception apparatus according to the present disclosure includes the
receiving coil and a reception unit that receives an AC signal via the coil portion
thereof.
[0014]
5 A non-contact power transmission system according to the present
disclosure includes a transmission apparatus that generates an AC signal and the
reception apparatus that receives the AC signal generated by the transmission
apparatus.
The transmission apparatus includes a transmitting coil portion in which a
10 wire is wound flatly and a transmission unit that supplies the AC signal to the
transmitting coil portion.
[0015]
According to the configuration in the present disclosure, the Q value can be
increased by forming a coil portion by winding a wire around a core having a
15 magnetic body. By arranging a non-magnetic body in a position at a predetermined
distance from a side face of the coil portion, degradation of the Q value when the coil
portion is inserted into a cabinet having a large amount of metal can be controlled.
Advantageous Effects of Invention
20 [0016]
According to the present disclosure, the Q value of a receiving coil used in a
reception apparatus can be increased and also the degradation of the Q value of the
receiving coil when put inside a cabinet can be decreased.
25 Brief Description of Drawings
[0017]
[FIG. 1] FIG. 1 is an external perspective view of a receiving coil according to an
embodiment of the present disclosure.
[FIG. 2] FIG. 2 is a front view of the receiving coil shown in FIG. 1.
30 [FIGS. 3(a) to 3(d)] FIGS. 3(a) to 3(d) are explanatory views showing a
manufacturing process of the receiving coil shown in FIG. 1.
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[FIG. 4] FIG. 4 is an explanatory view showing a combination example of a
conventional transmitting coil and receiving coil.
[FIG. 5] FIG. 5 is an explanatory view of a state in which a mobile terminal phone
mounted with the conventional receiving coil is arranged above the transmitting coil.
5 [FIG. 6] FIG. 6 is a graph showing the Q value of a primary coil when the mobile
terminal phone mounted with the conventional receiving coil is moved above the
transmitting coil.
[FIG. 7] FIG. 7 is an explanatory view showing the combination of the receiving coil
according to an embodiment of the present disclosure and a transmitting coil,
10 [FIG. 8] FIG. 8 is a graph showing an example of characteristics of the S value -
inter-coil efficiency in the combination of the receiving coil and the transmitting coil
in FIG. 7.
[FIG. 9] FIG. 9 is a graph showing an example of characteristics of the distance to the
primary coil - inter-coil efficiency in the combination of the receiving coil and the
15 transmitting coil in FIG. 7.
[FIG. 10] FIG. 10 is an explanatory view showing a state in which a metal is brought
closer to a side face of the receiving coil according to an embodiment of the present
disclosure.
[FIG. 11] FIG. 11 is a graph showing an example of characteristics of the distance
20 between metal and coil side face - Q value.
[FIG. 12] FIG. 12 is a schematic diagram of a non-contact power transmission system
including the receiving coil according to an embodiment of the present disclosure
and the transmitting coil.
25 Description of Embodiment
[0018]
An embodiment to carry out the present disclosure will be described with
reference to the appended drawings. The description will be provided in the
following order. Incidentally, elements common to each figure are denoted with the
30 same reference signs and a repeated description is omitted.
1. Structure of Receiving Coil According to an Embodiment (Example in
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Which Conductor is Wound around H-Type Core)
2. Combination of Conventional Transmitting Coil and Receiving Coil
3. Combination of Transmitting Coil and Receiving Coil According to an
Embodiment
5 4. Others
[0019]
<1. Structure of Receiving Coil According to an Embodiment
First, the structure of a receiving coil according to an embodiment
(hereinafter, referred-to also as the "present example") of the present disclosure will
10 be described with reference to FIGS. 1 and 2.
FIG. 1 is an external perspective view of a receiving coil according to an
embodiment of the present disclosure. FIG. 2 is a front view of the receiving coil
shown in FIG. 1. The receiving coil is a coil used on the receiving side of a noncontact
power transmission system that transmits power by electromagnetically
15 coupling two coils. Electromagnetic coupling is also called "electromagnetic
resonant coupling" or "electromagnetic resonance" and includes electric coupling and
magnetic coupling. Resonance is used in both cases and power transmission is
performed by electric or magnetic coupling to a resonant device only. In the
following example, electromagnetic coupling will be described.
20 [0020]
A receiving coil 1 in the present example is configured by winding a wire 5
(in the present example, the wire diameter (|> is 1.0 mm) obtained by bundling, for
example, 15 Litz wires (in the present example, the wire diameter § is 0.2 mm) in
which a plurality of thin annealed copper wires is stranded around a core (magnetic
25 core) 2 of H type as a side shape made of a magnetic material (for example, ferrite)
by a predetermined turn number. Then, a non-magnetic body 6 made of aluminum
(Al) of, for example, 0.5 mm in thickness is affixed to a resin portion 3 enclosing the
whole core 2 at a predetermined distance from an axis portion 2a of the core 2 in
parallel with the axis (Z axis) of the axis portion 2a of the core 2. While the non-
30 magnetic body 6 is affixed, the inductance (L value) of the receiving coil 1 is 7.61
uH and the Q value is 180.
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SP319120WO00
[0021]
Next, the manufacturing process of the receiving coil 1 will be described
with reference to FIGS. 3(a) to 3(d).
First, the H-type core 2 in which flange portions 2b, 2c are attached to both
5 ends of the axis portion 2a made of ferrite is created (FIG. 3(a)).
Subsequently, the resin portion 3 is formed by a technique such as molding
like covering the whole H-type core 2 with a resin (FIG. 3(b)). The resin portion
formed so that a side face 3a of the resin portion 3 is at a predetermined distance
from the center axis (Z axis) of the axis portion 2a of the core 2. In this example, a
10 void portion 4 is provided between the side face 3a of the resin portion 3 and a
portion corresponding to the axis portion 2a of the core 2 to reduce the amount of
resin used for the resin portion 3 and also to make the receiving coil 1 lighter.
Then, the wire 5 is wound around a portion of the axis portion 2a of the core
2 of the formed resin portion 3 (example of a coil portion) (FIG. 3(c)). The L value
15 is adjusted by the winding number.
Lastly, the tabular non-magnetic body 6 made of aluminum of, for example,
0.5 mm in thickness is affixed to the side face 3a of the resin portion 3 to complete
the receiving coil 1.
[0022]
20 Aluminum is affixed as a non-magnetic body in the present example, but a
non-magnetic material such as copper may also be used. One tabular non-magnetic
body is affixed, but the non-magnetic body may be affixed to two sides or three sides
like surrounding the core 2. A rectangular tabular non-magnetic material is used,
but a non-magnetic body may be provided around the axis portion 2a of the core 2
25 along the cylinder.
[0023]
The shape of the core is an H type in the present example, but
approximately the same result is obtained from a T type or an I type with a slightly
lower coupling coefficient. The T type is a shape in which only one of the flange
30 portions 2b, 2c is affixed to the core 2 in FIG. 3(a). The I type is a shape in which
none of the flange portions 2b, 2c is affixed or the area thereof is smaller than that of
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the H type.
[0024]
The distance between the axis portion 2a of the core 2 and the non-magnetic
body 6 (non-magnetic material such as a metal) is secured by the formed resin
5 portion 3 in the present example, but in addition to this method, a formed mold may
be affixed. To describe by taking FIG. 3(b) as an example, instead of integrally
configuring the whole resin portion 3, the formed mold is applied to the left portion
from the void portion 4.
[0025]
10 The sectional shape of the axis portion 2a of the core 2 in the present
example is rectangular, but may also be circular. Further, the same magnetic
material is used for the axis portion 2a and the flange portions 2b, 2c of the core 2,
but an amorphous alloy having a higher permeability may be applied to the flange
portions 2b, 2c. As the amorphous alloy, a cobalt (Co) group amorphous alloy like,
15 for example, Mg-Zn alloy is known. When the amorphous alloy is used, strength is
increased and so the flange portion can be made slimmer, resulting in miniaturization
of the core 2 as a whole. Further, the whole core 2 may be formed from an
amorphous alloy.
[0026]
20 <2. Combination of Conventional Transmitting Coil and Receiving Coil>
The combination of a conventional transmitting coil and receiving coil will
be described with reference to FIGS. 4 to 6.
FIG. 4 is an explanatory view showing a combination example of a
conventional transmitting coil and receiving coil. FIG. 5 is an explanatory view of a
25 state in which a mobile terminal phone mounted with the conventional receiving coil
is arranged above the transmitting coil. FIG. 6 is a graph showing the Q value of a
primary coil when the mobile terminal phone mounted with the conventional
receiving coil is moved above the transmitting coil.
[0027]
30 In the example of FIG 4, a transmitting coil 11 in a flat spiral shape is used
on the receiving side and the size of the transmitting coil 11 is set to, for example,
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SP319120WO00
190 X 150 mm. The transmitting coil 11 adopts alpha winding in which the wire of
the winding start and end is wound around the outer circumference of a coil. The
space factor can be improved by alpha winding. On the other hand, a receiving coil
15 in a flat spiral shape is used on the receiving side and the size of the receiving coil
5 15 is set to, for example, 40 X 30 mm. A magnetic sheet 12 (190 X 150 mm) and a
magnetic sheet 16 (40 X 30 mm) of ferrite of the same size as the respective coils are
affixed to the back surface (opposite surface with respect to the coil) of the
transmitting coil 11 and the receiving coil 15. In this .case, the Q value of the
transmitting coil 11 is 230.5, the Q value of the receiving coil 15 is 59.5, and the
10 coupling coefficient k is 0.096.
[0028]
As shown in FIG. 5, the receiving coil 15 is actually incorporated into a
mobile phone terminal 21 and the mobile phone terminal 21 is moved above the
transmitting coil 11 in the X direction and in the Y direction for measurement.
15 Incidentally, one corner of a rectangular coil shape is set as the origin. When the
mobile phone terminal 21 is placed in the approximate center (95 mm in the X
direction and 75 mm in the Y direction) of the transmitting coil 11, the Q value of the
transmitting coil 11 is degraded from 230.5 to 58 (see FIG. 6) and the Q value of the
receiving coil 15 is also degraded from 59.5 to 46.4. The inter-coil efficiency is
20 also degraded from 84% to 54% and further, the value of the coupling coefficient k is
degraded to 0.068, which is a value of level that is almost impracticable.
[0029]
<3. Combination of Transmitting Coil and Receiving Coil According to an
Embodiment
25 Next, the combination of a transmitting coil and a receiving coil according
to the present disclosure will be described with reference to FIGS. 7 to 9.
FIG. 7 is an explanatory view showing the combination of the receiving coil
according to an embodiment of the present disclosure and a transmitting coil. FIG.
8 is a graph showing an example of characteristics of the S value - inter-coil
30 efficiency in the combination of the receiving coil and the transmitting coil in FIG. 7.
FIG. 9 is a graph showing an example of characteristics of the distance to the primary
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coil - inter-coil efficiency in the combination of the receiving coil and the
transmitting coil in FIG. 7.
[0030]
A receiving coil 1A used for measurement shown in FIG. 7 has the same
5 structure as the receiving coil 1 in FIG. 1 except that the non-magnetic body 6 is not
included. The receiving coil 1A is actually incorporated into the mobile phone
terminal 21 and the mobile phone terminal 21 is moved above the transmitting coil
11 for measurement. The receiving coil 1A is arranged so that the center axis of the
axis portion 2a of the core 2 and the center axis (Z axis) of the flat transmitting coil
10 11 are parallel to each other.
[0031]
In this case, the Q value (Qi) of the transmitting coil 11 is degraded like the
conventional example in FIG. 4, but it is clear that, as shown in FIG. 8, the theoretical
value of the Q value (Q2) of the receiving coil 1A is 180 even if the receiving coil 1A
15 is incorporated into the mobile phone terminal 21 and is hardly degraded. When the
receiving coil 1A is actually contained in the mobile phone terminal 21, the coupling
coefficient k is 0.066, which is smaller than that of the conventional receiving coil 15
(FIG. 4). However, the Q value of the receiving coil 1A is far higher than the
conventional one and is not degraded, achieving 78% as the inter-coil efficiency.
20 As shown in FIG. 9, measurements of the distance between the receiving coil 1A and
the transmitting coil 11 are made in a plurality of arrangements by changing the
physical relationship between both on the XY plane and no significant degradation of
the inter-coil efficiency is observed. Therefore, regarding the inter-coil efficiency, it
can be said that the degree of freedom of arrangement with respect to a transmitting
25 coil is high and a very high level can be realized even if incorporated into a set
device.
[0032]
(Distance between a receiving coil and a metal plate)
Next, the distance between a receiving coil according to an embodiment of
30 the present disclosure and a metal plate will be described.
FIG. 10 is an explanatory view showing a state in which a metal plate 26 is
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brought closer to a side face of the receiving coil 1A made of a resin portion 3(a)
containing the core 2. FIG. 11 is a graph showing characteristics of the Q value
with respect to the distance between the receiving coil 1A (coil side face) and the
metal plate 26. In the present example, aluminum (Al) and stainless steel (SUS) of,
5 for example, 0.5 mm in thickness are used as the metal plates for measurement.
[0033]
In FIG. 11, the Q value of the receiving coil 1A tends to be degraded when
the metal plate 26 is present nearby and the Q value is more degraded with an
increasing area of the metal plate. Regarding the material of the metal, the Q value
10 of the aluminum is less degraded that that of stainless steel. This can be considered
to result from the fact that a magnetic line of force does not remain in a nonmagnetic
material like aluminum so that an eddy current is less likely to flow and
resistance to a high-frequency signal increases. It is clear that for a non-magnetic
material like aluminum, the influence is reduced when the distance from a coil
15 wound around the core is about 10 mm.
[0034]
In the example of FIG. 11, measurements are made using a non-magnetic
body of the thickness of 0.5 mm, but similar results are obtained when a nonmagnetic
body of aluminum or copper of the thickness of 0.3 mm is used. A non-
20 magnetic body of the thickness of 0.3 mm is advantageous to the use in a cabinet
whose design space is limited like a mobile phone terminal.
[0035]
Though it is known that a coil at a distance of about 10 mm from a nonmagnetic
body is less affected by the non-magnetic material, the distance may be set
25 up to about 5 mm due to restrictions of arrangement of an electronic device. In
such a case, problems of actual use may be avoided by adjusting the winding number
of wire by allowing for degradation of the Q value in advance and increasing the Q
value.
[0036]
30 In the present example using electromagnetic coupling, even if the coupling
coefficient k is small, the degree of freedom of arrangement of the transmitting coil
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and receiving coil is increased by increasing the Q value of primary and secondary
series resonant circuits. As an example, the coupling coefficient k between the
transmitting coil and receiving coil is designed to be 0.2 or less and the Q value of at
least one of the primary coil and secondary coil is designed to be 100 or more. The
5 coupling coefficient k depends on the size of the primary coil and the coupling
coefficient k increases with a decreasing size of the primary coil and the above
design is adopted in consideration of the above facts.
[0037]
(Effects of an embodiment)
10 According to a receiving coil according to an embodiment described above
and the combination of the receiving coil and a transmitting coil, the receiving coil
has a degree of freedom of arrangement with respect to the transmitting coil and can
receive power efficiently. That is, the degradation of the Q value of the receiving
coil when incorporated into an electronic device can be reduced and transmission of
15 power can be realized by ensuring the degree of freedom even if the Q value of the
transmitting coil is degraded when the electronic device is placed above the
transmitting coil.
[0038]
In addition, a receiving coil according to an embodiment using a wire as a
20 core is cheaper than a conventional spiral coil. Further, when compared with a
conventional spiral coil, receiving coils with less variations of the coil constant (for
example, the Q value) can be manufactured.
[0039]
In an embodiment example of the present disclosure, an example of
25 performing power transmission by the receiving coil 1(1 A) and the transmitting coil
11 shown in FIG. 7 has been described, but an embodiment is not limited to the
above example. For example, a repeater coil to make a magnetic flux uniform may
be provided in the transmitting coil 11 to transmit power from the transmitting coil
11 to the receiving coil 1 (1A) via the repeater coil.
30 [0040]
<4. Others>
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(Another embodiment of the receiving coil)
As another embodiment of the receiving coil according to the present
disclosure, a receiving coil having the following manufacturing process can be
considered,.
5 First, the coated wire 5 is wound around the H-type core 2 (corresponding to
FIG. 3(c)) (example of the coil portion). The L value is adjusted by the winding
number. Next, the core 2 around which the wire 5 is wound is inserted into a case
of a mold member formed from resin and fixed by an adhesive or the like
(corresponding to FIG. 3(b)). Then, the non-magnetic body 6 is affixed to the side
10 face of the mold member (corresponding to FIG. 3(d)). The receiving coil is
designed and manufactured so that the top surface of the flange portion 2b of the Htype
core 2 and the undersurface of the flange portion 2c are flush with the top
surface and the undersurface of the case of the mold member. If the receiving coil
is manufactured as described above, the height of the H-type core 2 and the height of
15 the case of the mold member can be made the same, which makes slimming down
easier to achieve when compared with a case of molding with resin.
[0041]
(Non-contact power transmission system using a receiving coil according to
the present disclosure and a transmitting coil)
20 A non-contact power transmission system using a receiving coil according
to the present disclosure described above and a transmitting coil will be described.
FIG. 12 is a schematic diagram of a non-contact power transmission system
including the receiving coil according to an embodiment of the present disclosure
and the transmitting coil. FIG. 1 shows an example of the most basic circuit
25 configuration (in the case of magnetic coupling) of a non-contact power transmission
system.
[0042]
The non-contact power transmission system in the present example includes
a transmission apparatus 31 and a reception apparatus 41.
30 The transmission apparatus 31 includes a signal source 32 containing an AC
power supply 33 that generates an AC signal and a resistive element 34, a capacitor
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35, and the transmitting coil (primary coil) 15. The resistive element 34 shows
internal resistance (output impedance) of the AC power supply 33 as an illustration.
The capacitor 35 and the transmitting coil 11 are connected to the signal source 32 so
as to form a series resonant circuit (example of the resonant circuit). Then, the
5 value (C value) of capacitance of the capacitor 35 and the value (L value) of
inductance of the transmitting coil 11 are adjusted so as to produce resonance at the
frequency to be measured. A transmission unit 37 including the signal source 32
and the capacitor 35 transmits power to the reception apparatus 41 through the
transmitting coil 11 in a non-contact manner (power transmission (power feed)).
10 [0043]
The reception apparatus 41 includes a charge unit 42 containing a capacitor
43 (secondary battery) and a resistive element 44, a rectifier 48 that converts an AC
signal into a DC signal, a capacitor 45, and the receiving coil (secondary coil) 1.
The resistive element 44 shows internal resistance (output impedance) of the
15 capacitor 43 as an illustration. The capacitor 45 and the receiving coil 1 are
connected to the charge unit 42 so that a series resonant circuit is formed and the
value (C value) of capacitance of the capacitor 45 and the value (L value) of
inductance of the receiving coil 1 are adjusted so as to produce resonance at the
frequency to be measured. A reception unit 47 including the charge unit 42, the
20 rectifier 48, and the capacitor 45 receive power from outside through the receiving
coil 1 in a non-contact manner (power reception).
[0044]
If the voltage between the transmitting coil 11 and the capacitor 35
constituting the series resonant circuit of the transmission apparatus 31 is VI
25 (example of the voltage applied to a resonant circuit) and the voltage between both
ends of the transmitting coil 11 is V2, the Q value of the series resonant circuit is
expressed as Q = V2/V1. This also applies to the reception apparatus 41.
[0045]
FIG. 12 shows a basic circuit including a series resonant circuit and thus, if
30 the function of the above circuit is included, various forms can be considered as a
detailed configuration. In FIG. 12, for example, the capacitor 43 is shown as an
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example of the load provided in the reception apparatus 41, but the present example
is not limited to the above example. In addition, the reception apparatus 41 may
include the signal source 32 (transmission unit 37) to transmit power to an external
apparatus via the receiving coil 1 in a non-contact manner or the transmission
5 apparatus 31 may include a load to receive power from an external apparatus via the
transmitting coil 11 in a non-contact manner. As the reception apparatus 41,
various electronic devices such as a mobile phone terminal and digital camera are
applicable.
[0046]
10 While the series resonant circuit is taken as an example in the present
example, a parallel resonant circuit may also be used as a resonant circuit. For
example, a parallel resonant circuit may be configured by connecting a first capacitor
in series to a parallel circuit of a second capacitor and the transmitting coil 11. Also,
a parallel resonant circuit may be configured by connecting a second capacitor in
15 parallel to a series circuit of a first capacitor and the transmitting coil 11. The Q
value is calculated by using the voltage VI between the transmitting coil 11 and the
first capacitor and the voltage, V2 between both ends of the transmitting coil 11
obtained from a parallel resonant circuit. The series resonant circuit and parallel
resonant circuit described above are only examples of the resonant circuit and the
20 configuration thereof is not limited to these configurations.
[0047]
A substrate with a capacitor to adjust the L value of the coil and the
resonance frequency may be affixed to a non-magnetic body of aluminum on the side
face of the receiving coil. The substrate may be affixed to both of the capacitor for
25 series resonant circuit and the capacitor for parallel resonant circuit so that the user
can select one of both substrates. By adjusting the resonance frequency during
manufacture as a resonant circuit module in this manner, there arises no need for the
user to adjust the frequency. For example, by combining the resonant circuit
module with a reception unit capable of receiving an AC voltage of the applicable
30 resonance frequency, the module can immediately be used as a reception apparatus.
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[0048]
Additionally, the present technology may also be configured as below.
(1) A receiving coil, including:
a core having a magnetic body;
5 a coil portion in which a wire is wound around the core and which is
electromagnetically coupled to an external coil to transmit power; and
a non-magnetic body arranged at a predetermined distance from a side face
of the coil portion.
(2) The receiving coil according to (1), wherein the non-magnetic body has a
10 thickness of 0.3 mm or more*
(3) The receiving coil according to (1) or (2), further comprising: a resin portion
containing the core having the magnetic body and the coil portion,
wherein the non-magnetic body is arranged on a side face of the resin
portion.
15 (4) The receiving coil according to any one of (1) to (3), wherein the core has
an H-type shape.
(5) A reception apparatus, including:
a core having a magnetic body;
a coil portion in which a wire is wound around the core and which is
20 electromagnetically coupled to an external coil to transmit power;
a non-magnetic body arranged at a predetermined distance with respect to a
side face of the coil portion; and
a reception unit that receives an AC signal via the coil portion.
(6) A non-contact power transmission system including:
25 a transmission apparatus that generates an AC signal; and
a reception apparatus that receives the AC signal generated by the
transmission apparatus,
wherein the transmission apparatus includes:
a transmitting coil portion in which a wire is wound flatly; and
30 a transmission unit that supplies the AC signal to the transmitting coil
portion, and
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wherein the reception apparatus includes:
a core having a magnetic body;
a receiving coil portion in which a wire is wound around the core and which
is electromagnetically coupled to the transmitting coil portion to transmit power;
5 a non-magnetic body arranged at a predetermined distance with respect to a
side face of the receiving coil portion; and
a reception unit that receives the AC signal via the receiving coil portion.
(7) The non-contact power transmission system according to (6), wherein a
magnetic sheet arranged on a surface of the transmitting coil portion opposite to the
10 receiving coil portion is included.
[0049]
The present disclosure is not limited to each of the above embodiments and
other various modifications and application examples can naturally be developed
without deviating from the spirit of the present disclosure described in claims.
15
Reference Signs List
[0050]
1, 1A
2
2a
2b, 2c
3,3A
3a
4
5
6
11
12
15
16
21,31
receiving coil
core (H type)
axis portion
flange portion
resin portion
side face
void portion
wire
non-magnetic body
transmitting coil
magnetic sheet
receiving coil
magnetic sheet
mobile phone terminal (electronic device)
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31
32
33
34
35
15
37
41
42
43
44
45
47
48
transmission apparatus
signal source
AC power supply
resistive element
capacitor
transmitting coil
transmission unit
reception apparatus
charge unit
capacitor
resistive element
capacitor
reception unit
rectifier

20/22
SP319120WO00
CLAIMS
Claim 1
A receiving coil, comprising:
a core having a magnetic body;
5 a coil portion in which a wire is wound around the core and which is
electromagnetically coupled to an external coil to transmit power; and
a non-magnetic body arranged at a predetermined distance from a side face
of the coil portion.
10 Claim 2
The receiving coil according to claim 1, wherein the non-magnetic body has
a thickness of 0.3 mm or more.
Claim 3
15 The receiving coil according to claim 2, further comprising: a resin portion
containing the core having the magnetic body and the coil portion,
wherein the non-magnetic body is arranged on a side face of the resin
portion.
20 Claim 4
The receiving coil according to claim 3, wherein the core has an H-type
shape.
Claim 5
25 A reception apparatus, comprising:
a core having a magnetic body;
a coil portion in which a wire is wound around the core and which is
electromagnetically coupled to an external coil to transmit power;
a non-magnetic body arranged at a predetermined distance with respect to a
30 side face of the coil portion; and
a reception unit that receives an AC signal via the coil portion.
•
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10
15
Claim 6
A non-contact power transmission system comprising:
a transmission apparatus that generates an AC signal; and
a reception apparatus that receives the AC signal generated by the
transmission apparatus,
wherein the transmission apparatus includes:
a transmitting coil portion in which a wire is wound flatly; and
a transmission unit that supplies the AC signal to the transmitting coil
portion, and
wherein the reception apparatus includes:
a core having a magnetic body;
a receiving coil portion in which a wire is wound around the core and which
is electromagnetically coupled to the transmitting coil portion to transmit power;
a non-magnetic body arranged at a predetermined distance with respect to a
side face of the receiving coil portion; and
a reception unit that receives the AC signal via the receiving coil portion.
20
Claim 7
The non-contact power transmission system according to claim 6, wherein a
magnetic sheet arranged on a surface of the transmitting coil portion opposite to the..
receiving coil portion is included.