CN203871929U - Power transmission apparatus, power supplying apparatus, power receiving apparatus and coil apparatus - Google Patents

Abstract

The utility model discloses a power transmission device, a power transmission device, a power reception device and a coil device, which can suppress the variation of the coupling coefficient k even if the position of the power reception coil changes relative to the power transmission coil. The power transmission device has a power transmitting device and a power receiving device, and can transmit power from the power transmitting device to the power receiving device in a non-contact manner through electromagnetic coupling. The power transmitting device includes: a power transmitting coil; The resonance element of the coil supplies AC power, and the power receiving device includes: a power receiving coil for receiving power; and a rectification circuit for rectifying the AC power induced by the resonance element including the power receiving coil, wherein the power transmitting coil and the power receiving coil One of the coils includes a first coil pattern, has a balance area in the center, and is formed in a planar shape at a peripheral portion of the balance area, and the other coil of the power transmitting coil and the power receiving coil includes a second coil pattern, and the balance area is formed in a planar shape. The regions correspond to and are formed in a planar shape.

Description

Power transmission device, power transmission device, power receiving device and coil device

technical field

The utility model relates to a power transmission device, a power transmission device, a power receiving device and a coil device. the

Background technique

In recent years, devices that transmit electric power in a non-contact manner have become widespread. The power transmission device includes a power transmission device that supplies power, and a power receiving device that receives the transmitted power, and uses electromagnetic induction, magnetic resonance, or electric field coupling to transmit power from the power transmitting device to the power receiving device in a non-contact manner . The power receiving device includes a drive circuit for driving the device itself, a load circuit such as a charging circuit for a secondary battery mounted in the power receiving device, and the like. the

When transmitting power to electronic devices such as portable terminals and notebook computers in a non-contact manner, when using electromagnetic induction or electric field coupling, generally speaking, it is necessary to make the power transmitting device and power receiving device roughly within the transmittable area. cling. On the other hand, when using the magnetic field resonance method, it is not necessary to bring the power transmitting device and the power receiving device into close contact, and power transmission can be performed even if the power receiving device is several centimeters away from the power transmitting device. Therefore, there is a degree of freedom in the position where the power receiving device is placed, and the magnetic resonance method is attracting attention because it is excellent in usability. the

The magnetic resonance method can transmit electric power by coupling between a resonant element (also referred to as a resonant element) consisting of a coil and a capacitor installed in a power transmitting device and a resonant element consisting of a coil and a capacitor installed in a power receiving device. In the electromagnetic induction method, not only the coil on the power transmitting side and the coil on the power receiving side are coupled, but also capacitors for resonance are provided on both the power transmitting side and the power receiving side, and the elements on the power transmitting side and the power receiving side are Resonant coupling, after an attempt has been made to extend the distance over which power is transmitted, there is no difference between magnetic resonance and electromagnetic induction. the

In addition, as a parameter that affects the power transmission efficiency, there is a coupling coefficient k between the resonance elements of the power transmitting device and the power receiving device. When the distance between the resonance elements of the power transmitting device and the power receiving device changes, the coupling coefficient k usually also changes. For example, when the distance between the resonant elements is widened, the coupling coefficient k becomes smaller. As long as the impedance of the circuit is constant, the power transmission efficiency and the power that can be transmitted will change with the change of the coupling coefficient k. the

As a method of maintaining high power transmission efficiency even when the coupling coefficient k changes with the variation of the distance between the resonant elements of the power transmitting device and the power receiving device, there is known a technology that provides impedance adjustment capable of variable impedance part, and change the impedance of the power transmitting device and the power receiving device according to the change of the coupling coefficient k (refer to Japanese Patent Document 1). the

However, in the technology disclosed in Japanese Patent Document 1, a circuit for automatically performing impedance control when the coupling coefficient k fluctuates is newly required, and there is a problem that the control also becomes complicated. the

On the other hand, as a device that can transmit power even if the positions of the power transmitting coil and the power receiving coil are slightly shifted, there is known a non-contact charging device that uses a large-diameter coil for the power transmitting coil and A small-diameter coil is used as the coil (see Japanese Patent Document 2). the

However, in the example disclosed in Japanese Patent Document 2, when the distance between the power transmitting coil and the power receiving coil increases because the power receiving coil and the power transmitting coil are shifted in the vertical direction, the coupling coefficient k suddenly decreases, Thus, there is a problem in that power transmission efficiency deteriorates and desired power cannot be transmitted. the

Japanese Patent Document 1: Japanese Patent Application Publication No. 2011-50140

Japanese Patent Document 2: Japanese Patent Application Publication No. 2008-301553

Utility model content

In view of the above problems, an object of the present invention is to provide a non-contact power transmission device, a power transmission device, a power receiving device, and a coil device that can suppress the position of the power receiving coil relative to the power transmitting coil. Variation of the coupling coefficient k. the

The power transmission device of the present utility model has a power transmission device and a power receiving device, and can perform power transmission from the power transmission device to the power receiving device in a non-contact manner through electromagnetic coupling, and the power transmission device includes: an electric coil; and an AC power supply for supplying AC power to a resonant element including the power transmitting coil, and the power receiving device includes: a power receiving coil for receiving electric power; and a rectifier circuit for connecting with the power receiving coil The AC power induced by the resonance element is rectified, wherein one coil of the power transmitting coil and the power receiving coil includes a first coil pattern, has a balance area in a central portion, and is formed in a peripheral portion of the balance area. In a planar shape, the other coil of the power transmitting coil and the power receiving coil includes a second coil pattern corresponding to the balance area and formed in a planar shape. the

In the power transmission device described above, the balance region is composed of a forward wiring pattern and a reverse wiring pattern. the

In the power transmission device described above, the second coil pattern has an outer dimension equal to or smaller than that of the balance area. the

In the power transmission device described above, the first coil pattern and the second coil pattern are formed on a substrate. the

In the above-mentioned power transmission device, an area of the balance region is 30% to 50% of an outer shape area of the first coil pattern. the

In the power transmission device described above, the power transmission coil and the power reception coil are formed in a polygonal shape. the

In the power transmission device described above, the first coil pattern is provided on a peripheral portion of the balance region, and is composed of a plurality of patterns folded back from an outer edge portion. the

The power transmission device of the present invention performs power transmission in a non-contact manner through electromagnetic coupling with respect to the power receiving device. The power transmission device includes a first coil pattern, has a balance area in the center, and has a The peripheral portion is formed in a planar shape. the

The power receiving device of the present utility model receives the power transmitted from the power transmitting device in a non-contact manner through electromagnetic coupling, the power receiving device includes a first coil pattern, has a balance area in the center, and the balance area The peripheral portion is formed in a planar shape. the

The coil device of the present utility model is used for a power transmission device that transmits power from a power transmitting coil to a power receiving coil through electromagnetic coupling in a non-contact manner, and any one of the power transmitting coil and the power receiving coil includes a coil The pattern has a balance area at the center, and is formed in a polygonal planar shape at the periphery of the balance area. the

According to the present invention, even if the position of the power receiving coil changes with respect to the power transmitting coil, it is possible to suppress fluctuations in the coupling coefficient k. the

Description of drawings

Next, a power transmission device, a power transmission device, a power reception device, and a coil device according to the present invention will be described with reference to the drawings. A more complete and better understanding of the invention, and many of its attendant advantages, are readily apparent by reference to the following detailed description when considered in conjunction with the accompanying drawings, but the accompanying drawings illustrated here are intended to provide a further understanding of the invention , constituting a part of this application, the exemplary embodiments of the utility model and its description are used to explain the utility model, and do not constitute an improper limitation of the utility model, wherein:

FIG. 1 is a circuit block diagram showing the configuration of a power transmission device according to an embodiment;

Fig. 2 is a perspective view showing the configuration of a power transmission device according to an embodiment;

FIG. 3( a ) is a perspective view schematically showing the coil device including the power transmitting coil 13 and the power receiving coil 22 , and FIG. 3( b ) is a top view schematically showing the coil device including the power transmitting coil 13 and the power receiving coil 22 ;

Figure 4(a) and Figure 4(b) are cross-sectional views showing the positional relationship between the power transmitting device and the power receiving device in one embodiment;

Figure 5(a) and Figure 5(b) are cross-sectional views showing other positional relationships between the power transmitting device and the power receiving device in an embodiment;

Fig. 6 (a) and Fig. 6 (b) are the top view of an example of the shape and the size that represent the coil device in an embodiment;

Fig. 7 is a top view showing a power transmission coil of a common power transmission device;

8 is an explanatory diagram showing a measurement system of a coupling coefficient k in a power transmission device according to an embodiment;

Fig. 9 is a characteristic diagram showing the relationship between the distance between the power transmitting and receiving coils and the coupling coefficient k in an embodiment and a common example;

Figure 10(a) and Figure 10(b) are cross-sectional views showing the positional relationship of the coil patterns of the usual power transmitting coil and power receiving coil;

Figure 11(a) and Figure 11(b) are cross-sectional views showing the positional relationship of the coil patterns of the power transmitting coil and the power receiving coil in one embodiment;

Fig. 12 is a top view showing that the power receiving coil is moved horizontally in one embodiment;

Fig. 13 is a characteristic diagram showing the relationship between the amount of deviation in the horizontal direction and the coupling coefficient k in an embodiment and a common example;

Fig. 14 (a) and Fig. 14 (b) are the plan views that represent the angular coil and circular coil in one embodiment;

15 is a perspective view showing the configuration of the power transmission device according to the second embodiment;

Fig. 16 is a plan view showing an example of the shape and size of the coil device in an embodiment;

Fig. 17 is a plan view showing an example of the shape and size of the coil device in an embodiment;

Fig. 18 is a plan view showing an example of the shape and size of the coil device in an embodiment;

Fig. 19 is a plan view showing an example of the shape and size of the coil device in an embodiment;

Fig. 20 is a plan view showing an example of the shape and size of the coil device in an embodiment; and

Fig. 21 is a plan view showing an example of the shape and size of a coil device in an embodiment. the

Explanation of reference signs

10 Power transmission device 11 AC power supply

13 Power transmission coil 131, 221 Coil pattern

14, 23 Resonant components 15, 26 Chassis

17, 27 Substrate 18, 28 Balance area

20 Power receiving device 22 Power receiving coil

24 rectifier circuit

Detailed ways

It should be noted that, in the case of no conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other. The utility model will be described in detail below with reference to the accompanying drawings and in conjunction with the embodiments. the

Below, with reference to accompanying drawing, the embodiment that is used for implementing the present utility model is described. In addition, in each drawing, the same code|symbol is used for the vicinity of the same place. the

first embodiment

FIG. 1 is a circuit block diagram showing the overall configuration of a power transmission device according to a first embodiment. 2 is a perspective view schematically showing a power transmission (power supply) device and a power reception (power consumption) device constituting the power transmission device. As shown in FIG. 1 , the power transmission device includes a power transmission device 10 that supplies power, and a power reception device 20 that receives the supplied power. The power transmitting device 10 and the power receiving device 20 transmit electric power by means of electromagnetic coupling using a magnetic resonance method, an electromagnetic induction method, or the like. Next, a case where electric power is transmitted by a magnetic resonance method or an electromagnetic induction method will be described. the

The power transmission device 10 has an AC power source 11 that generates electric power, and a resonant element 14 composed of a resonant capacitor 12 and a power transmission coil 13 . The AC power source 11 generates AC power at the same or substantially the same frequency as the self-resonant frequency of the power transmission resonant element 14 , and supplies it to the resonant element 14 . The AC power supply 11 includes an oscillation circuit that generates AC power at a target frequency, and a power amplifier circuit that amplifies the output of the oscillation circuit. Alternatively, the AC power supply 11 may be a switching power supply, and a switching element may be turned on/off by an output of an oscillation circuit. the

In addition, the AC power supply 11 can be supplied with DC power from an AC adapter or the like installed outside the power transmission device 10 . Alternatively, AC 100V may be supplied to the power transmission device 10 from the outside, and an AC adapter or an AC/DC conversion unit may be provided in the power transmission device 10 to supply DC power to the AC power source 11 . the

The power receiving device 20 includes a resonant element 23 including a resonant capacitor 21 and a power receiving coil 22 , a rectifier circuit 24 for converting an alternating current to a direct current, and a load circuit 25 . The self-resonant frequency of the power receiving resonant element 23 is the same or substantially the same as the self-resonant frequency of the power transmitting resonant element 14 , and by mutual electromagnetic coupling, electric power is efficiently transmitted from the power transmitting side to the power receiving side. the

The load circuit 25 is a circuit of an electronic device such as a portable terminal or a tablet terminal, and the electric power received by the power receiving device 20 is used for operating the electronic device, charging a storage battery built in the electronic device, and the like. In general, since the load circuit 25 operates with DC power, in order to supply DC power to the load circuit 25, a rectifier circuit 24 is provided that rectifies the AC power induced by the power receiving resonant element 23 and converts it into DC power. the

In addition, the capacitors 12 and 21 for resonance do not necessarily need to be constituted by electronic components, and may be replaced by the capacitance between lines of the coil, etc. according to the shape of the coil and the inductance value of the coil. In addition, although the resonance capacitor 12 is arranged in series with the power transmission coil 13 and the resonance capacitor 21 is arranged in series with the power receiving coil 22 to form a series resonance circuit, each resonance capacitor may be arranged in parallel with the coils to form a parallel resonance circuit. the

As shown in FIG. 2 , in the power transmission device of FIG. 1 , power is transmitted to the power receiving device 20 by superimposing the power receiving coil 22 on the power transmitting coil 13 of the power transmitting device 10 . That is, by flowing (conducting) an alternating current in the power transmission coil 13 , a magnetic field is generated in the power transmission coil 13 . On the other hand, in the power receiving coil 22 , an alternating current flows through the power receiving coil 22 due to electromagnetic coupling, and electric power can be obtained by rectifying the current. the

In FIG. 2 , the power transmission device 10 has a housing 15 having a flat main body such as a power receiving device 20 placed thereon, and a power transmission coil 13 is arranged in the housing 15 . Furthermore, the power receiving device 20 has a chassis 26 such as a flat-shaped main body, and can be placed on the power transmitting device 10 . The power receiving coil 22 is disposed in a housing 26 of the power receiving device 20 so as to face the power transmitting coil 13 . the

3( a ) is a perspective view schematically showing the coil device including the power transmitting coil 13 and the power receiving coil 22 , and FIG. 3( b ) is a plan view schematically showing the coil device including the power transmitting coil 13 and the power receiving coil 22 . The power transmission coil 13 is constituted by, for example, a quadrangular coil pattern 131 formed on the printed circuit board 17 . The region 18 at the center of the power transmission coil 13 adopts a balance effect of canceling the effect of magnetic flux by utilizing the balance formed by the forward wiring pattern and the reverse wiring pattern. Balance is the result that all the forces acting on the magnetic flux are balanced with each other. When the magnetic flux is always in the same state continuously, the magnetic flux generated from the current flowing in the forward direction and the magnetic flux generated from the current flowing in the opposite direction are in mutual relationship. offset state. The coupling of the magnetic fluxes of the power transmitting coil and the power receiving coil almost disappears (not completely disappears) and becomes small in the balance region where the magnetic flux is canceled. The coil pattern 131 has a balance region, and the coil pattern 131 is composed of a planar pattern that is folded back multiple times (approximately three turns in the example of FIG. 3 ) at the peripheral portion of the balance region 18 . the

On the other hand, the power receiving coil 22 is provided correspondingly to the balance area 18, and has approximately the same size as the balance area 18 or a smaller size than the balance area 18, such as four corners formed on the printed circuit board 27. shape and a planar coil pattern 221 . the

The power transmitting coil 13 is provided along the upper surface inside the housing 15 , and the power receiving coil 22 is provided along the lower surface inside the housing 26 . In order to transmit electric power from the power transmission coil 13 to the power reception coil 22 in a non-contact manner, the power transmission coil 13 and the power reception coil 22 must be arranged as close as possible to each other. In addition, the power transmitting coil 13 and the power receiving coil 22 can be formed into planar coils by winding copper wires or stranded wires, in addition to forming coil patterns on printed circuit boards or flexible substrates. the

4( a ) and FIG. 4( b ) are cross-sectional views of the power transmitting device 10 and the power receiving device 20 . Case 26; Fig. 4(b) shows the state where the case 26 of the power receiving device 20 is directly placed on the case 15 of the power transmitting device 10, the distance between the power transmitting coil 13 and the power receiving coil 22 is the smallest, and is at close state. the

FIG. 5( a ) and FIG. 5( b ) are other cross-sectional views of the power transmitting device 10 and the power receiving device 20 . FIG. 5( a ) shows a case where the housing 26 of the power receiving device 20 is placed in the cover 31 for the purpose of protection or the like. As for FIG. 4( b ), the distance between the power transmitting coil 13 and the power receiving coil 22 only increases the thickness of the cover 31 . The thickness of the cover 31 varies, but when the virtual power receiving device 20 is a mobile terminal or a tablet terminal, for example, the thickness of the cover 31 is considered to be about 5 mm. the

FIG. 5( b ) assumes a case in which a mobile terminal or a tablet terminal is carried in a bag, placed in the bag as it is, and placed on the chassis 15 of the power transmission device 10 to be charged. The distance between the power transmission coil 13 and the power reception coil 22 can only be increased in accordance with the thickness of the cover 31 and the case 32 . Assuming that compared with Fig. 4(b), the distance is increased by about 10mm to 20mm. the

In an ordinary power transmission coil, that is, a power transmission coil without a balance area 18 and the coil is wound near the center, the coupling coefficient k between the coils becomes large as long as the distance between the power transmission coil and the power reception coil changes by several millimeters. The power that can be transmitted also fluctuates greatly. On the other hand, in the first embodiment, even if the distance between the power transmitting coil 13 and the power receiving coil 22 varies, the coupling coefficient k hardly varies. the

6( a ) and FIG. 6( b ) are plan views showing examples of specific shapes and dimensions of the coil device in the first embodiment. As shown in FIG. 6( a ), the power transmission coil 13 has a coil pattern 131 formed on the printed circuit board 17 , and the outer shape of the power transmission coil 13 is a square of L11 = W11 = 153 mm. The width of the coil pattern was 3 mm, the gap between the adjacent coil patterns was 3 mm, and the shape was wound about 6 turns. The inductance value is about 10.23uH. the

The balance region 18 at the center of the power transmission coil 13 is W12=80 mm, L12=80 mm, and the area of the balance region 18 is L12×W12=6400 mm ² .

The external area of the power transmission coil 13 is L11×W11=153×153=23409 mm ² , and the ratio of the balance area 18 to the whole power transmission coil is 6400/23409×100=27.34% (≈30%).

FIG. 6( b ) is a diagram showing an example of a specific shape and size of the power receiving coil 22 . The power receiving coil 22 has a coil pattern 221 formed on the printed circuit board 27, and the outer shape of the power receiving coil 22 is a square of L21=W21=65 mm. The width of the coil pattern was 3 mm, the gap between the adjacent coil patterns was 2 mm, and the shape was wound about 6 turns. The inductance value is about 1.67uH. the

The area of the power receiving coil 22 is L21×W21=65×65=4225 mm ² , which is smaller than the area of the balance region 18 of the power transmitting coil 13 . In addition, the area of the power receiving coil 22 does not necessarily have to be smaller than the area of the balance area 18 , and may be equal to or slightly larger.

Next, the operation of the power transmission device according to the first embodiment will be described. The positional relationship between the power transmitting coil 13 and the power receiving coil 22 shown in FIG. 6(a) and FIG. 6(b) is directly placed on the power transmitting device 10 as a charging station, and the mobile terminal on the side to be charged, In the case of the power receiving device 20 of a tablet terminal, as shown in FIG. 4( b ), the distance between the power transmitting coil 13 and the power receiving coil 22 is the closest. As shown in FIG. 5( a ), a cover 31 is added to carry or protect the case 26 of the power receiving device 20 , and it is put in a bag 32 and placed on the power transmitting device 10 as shown in FIG. 5( b ). , the distance between the power transmitting coil 13 and the power receiving coil 22 is widened. the

Conventionally, when the distance between the power transmitting coil and the power receiving coil changes, the coupling coefficient k changes, and if the impedance is not controlled, the amount of power that can be received by the power receiving device 20 and the power transmission efficiency also change. Under the condition that the impedance is not controlled, the acceptable electric power is the largest at a certain distance, and the acceptable electric power decreases when the distance is widened or approached. the

FIG. 7 shows an example of a specific shape and size of a general power transmission coil 41 . The outer dimension is L41=W41=153 mm, which is the same as that of the power transmission coil 13 of the embodiment. The difference is that the coil pattern 411 is wound up to the center. the

Here, when the power transmission coil 13 and the power reception coil 22 of the embodiment are combined, and when the conventional power transmission coil 41 and the power reception coil 22 are combined, how the coupling coefficient k changes when the distance between the coils changes is compared. . the

The coupling coefficient k can actually measure the self-inductance Lopen and the leakage inductance Lsc, and obtain it according to the formula (1). the

【Formula 1】

$\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; =</span>\sqrt{\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; -</span>\frac{\mathrm{<span\; class="notranslate">\; Lsc</span>}}{\mathrm{<span\; class="notranslate">\; Lopen</span>}}}<span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>$

FIG. 8 is a diagram showing a measurement system of the coupling coefficient k in the power transmission device. As shown in Figure 8, a coil 51 is connected to a measuring device 53 such as an LCR meter, and the measuring device 53 is used to measure the self-inductance Lopen when the two ends 54 and 55 of the other coil 52 are open, and the two ends 54 and 55 are short-circuited. When the leakage inductance Lsc, and according to the formula (1) to find the coupling coefficient k. the

FIG. 9 is a graph showing the characteristics of the coupling coefficient k when the distance between the power transmitting coil and the power receiving coil is changed. The lower line of FIG. 9 (the line marked with the present application) shows the characteristics when the power transmitting coil 13 and the power receiving coil 22 of the embodiment of the present application are adopted, and the upper line (the line marked with the prior art) shows the characteristics of the prior art. The characteristics when the power transmitting coil 41 and the power receiving coil 22 of FIG. 7 are used. the

In the case of using the power transmission coil 13 of the embodiment, when the distance between the power transmission coil 13 and the power reception coil 22 changes from 5 mm to 50 mm, the coupling coefficient k gradually decreases. On the other hand, when the power transmission coil 41 is used, the closer the distance between the power transmission coil 41 and the power reception coil 22 is, the larger the rate of change in the coupling coefficient k becomes, and the further the distance is, the greater the coupling coefficient k becomes. changes become slower. In addition, it can also be known that when the distance between the power transmitting coil and the power receiving coil is increased to about 50 mm, the coupling coefficient k is close to the embodiment. the

However, when used for charging an actual device, the pitch between the power transmitting and receiving coils is often less than or equal to 20 mm. Therefore, when calculating the change rate of the coupling coefficient k when the distance between the power transmitting and receiving coils is changed from 5 mm to 20 mm, it becomes 0.148/0.186=0.796 in the example of the embodiment of the present application. That is, the value of the coupling coefficient k when the pitch between the power transmitting and receiving coils is 20 mm is about 80% of the value when the pitch between the power transmitting and receiving coils is 5 mm. the

In view of this, in the wire of the prior art, when the change rate of the coupling coefficient k is calculated when the power transmission and reception distance changes from 5mm to 20mm, it is 0.224/0.375=0.597, and the power transmission and reception coil The value of the coupling coefficient k when the pitch is 20 mm is reduced to about 60% of the value when the pitch between the power transmitting and receiving coils is 5 mm. the

Thus, by using the power transmission coil 13 of the embodiment, it is possible to slow down the change in the coupling coefficient k with respect to the change in the pitch between the power transmission and reception coils. As a result, the acceptable power amount and power transmission efficiency change only a little, and complicated controls such as impedance control are unnecessary. the

Hereinafter, the above reasons will be briefly described with reference to FIGS. 10 and 11 . FIG. 10 shows the case where the power transmission coil 41 ( FIG. 7 ) in which the coil pattern 411 is formed near the center is used, and FIG. 11 shows the case where the power transmission coil 13 according to the embodiment is used. the

First, consider the case where the power transmission coil 41 shown in FIG. 10( a ) and FIG. 10( b ) is used. When the power transmitting coil 41 and the power receiving coil 22 are close to each other as shown in FIG. . The ellipse surrounded by dotted lines in FIG. 10 schematically shows that the coils are coupled to each other. the

When the power transmitting coil 41 and the power receiving coil 22 are separated as shown in FIG. 10( b ), the coupling coefficient k becomes weaker compared with the case of FIG. 10( a ), and decreases according to the distance (see FIG. 9 ). . In particular, as shown in FIG. 10( a ), when the coils are strongly coupled to each other, the coupling coefficient k tends to vary greatly when the pitch of the power transmitting and receiving coils changes slightly. the

On the other hand, when the power transmitting coil 13 is used, if the power transmitting coil 13 and the power receiving coil 22 are placed close to each other as shown in FIG. 11( a ), no power is transmitted at the position facing the power receiving coil 22 A region 131 of the coil 13 is composed of a forward wiring pattern and a reverse wiring pattern. Coil pattern 131 and coil pattern 221, as shown by the dotted ellipse in FIG. 11 , are mainly coupled at the edges of the coils, so the coupling is not strong. As a result, even if the coils are close to each other, the coupling coefficient k is not large. value. the

In addition, when the power transmitting coil 13 and the power receiving coil 22 are separated as shown in FIG. 11( b ), as shown by the dotted ellipse in FIG. The area of the coil pattern contributing to the coupling is qualitatively larger than the case where the coils are close to each other in FIG. 11( a ). That is, by increasing the area of the coil pattern that contributes to the coupling, it is possible to offset to some extent the reduction in coupling caused by increasing the distance between the coils. As a result, when the distance between the power transmitting and receiving coils is increased, the coupling coefficient k tends to decrease, but the change becomes slow as indicated by the lines of the present application in FIG. 9 . the

The above describes the case where the distance between the power transmitting coil 13 and the power receiving coil 22 is changed, but even when the position of the power receiving coil 22 changes along the power transmitting coil 13 , the change in the coupling coefficient can be reduced. the

FIG. 12 shows a case where the power receiving coil 22 shown in FIG. 3 is moved in the arrow X direction along the power transmitting coil 13 . In addition, the lines of this application in FIG. 13 show the change characteristics of the coupling coefficient k when the power receiving coil 22 is moved in the arrow X direction. In addition, the prior art line in FIG. 13 is used for comparison, and shows the coil 41 having a coil pattern all the way to the center as shown in FIG. Variation characteristics of the coupling coefficient k. The coil 41 used in the comparison was wound about 6 turns and had an inductance value of about 1.5 uH. the

In FIG. 13 , the amount by which the power receiving coil 22 is moved along the power transmitting coil 13 is indicated as a horizontal shift amount. In the comparative example (the conventional wire), as the amount of offset in the horizontal direction increases, the opposing area of the power transmitting side coil and the power receiving side coil decreases, and the coupling coefficient k decreases significantly. On the other hand, in the example (the line of the present application), the coupling coefficient k hardly changes until the deviation is 40 mm, and the coupling coefficient k decreases slightly even when the deviation is about 50 mm. the

The reason for the above is that even if the power receiving coil 22 moves along the power transmitting coil 13 , the change in the area of the power transmitting coil and the power receiving coil contributing to the coupling is considered to be small. In the case of the embodiment, as long as the power receiving coil 22 does not exceed the power transmitting coil 13 , the change in the coupling coefficient k can be made small. the

In addition, in the embodiment, although an example in which the power transmitting coil 13 and the power receiving coil 22 are substantially square is shown, they need not be limited to a square, and may be quadrangular (square) such as a rectangle or other shapes (hexagonal). , octagon, etc.) of polygons. A circular shape may also be used, but a polygonal shape is preferable in consideration of the allowance for moving the power receiving coil 22 along the power transmitting coil 13 . the

FIG. 14( a ) shows the case where the power transmission coil 13 and the power reception coil 22 are formed in an angular shape, and FIG. 14( b ) shows the case where the power transmission coil 13 and the power reception coil 22 are formed in a circular shape. As shown in Fig. 14(a), when the shape is angular, even if the position of the power receiving coil 22 is moved to a corner position on the diagonal line of the power transmitting coil 13, the pattern 221 of the power receiving coil 22 does not exceed the power transmitting coil 13 pattern 131, so as to obtain the characteristic that the coupling coefficient k is almost constant. the

On the other hand, when it is circular, the position where the pattern 221 of the power receiving coil 22 does not exceed the pattern 131 of the power transmitting coil 13 becomes the position shown in FIG. 14( b ). When the center position (cross) of the power receiving coil 22 at this time is compared with the angle shape and the circle shape, it is known that the circle shape is close to the center of the power transmission coil 13 . That is, the movable distance is S1 for the angular shape and S2 for the circular shape ( S1 > S2 ). In this way, when comparing the angular coil and the circular coil having the same maximum external dimensions of the power transmitting coil 13 , the use of the angular coil can broaden the allowable range for the misalignment of the power receiving coil 22 . the

In addition, the numerical values, such as the dimension of the coil shown in an Example, are shown as an example, and are not limited to these numerical values. Also, although the ratio of the balance region 18 to the entire power transmission coil is described as about 40%, it is not limited to 30%, and the same effect can be obtained even if it is in a range of about 10% to 50%. the

Second embodiment

Next, a second embodiment will be described with reference to FIG. 15 . The second embodiment is a configuration in which the shapes of the power transmission coil 13 of the power transmission device 10 and the power reception coil 22 of the power reception device 20 are reversed. That is, the power receiving coil 22 is constituted by, for example, a coil pattern 221 formed on a printed circuit board, and a central region 28 thereof is a balanced region composed of a forward wiring pattern and reverse wiring. The coil pattern 221 is provided on the peripheral portion of the balance area 28, and is composed of a plurality of folded patterns from the outer edge portion. the

On the other hand, the power transmission coil 13 is constituted by, for example, a coil pattern 131 formed on a printed circuit board with an outer shape substantially equal to or smaller than the size of the balance region 28 . The power transmitting coil 13 is provided along the upper surface inside the housing 15 , and the power receiving coil 22 is provided along the lower surface inside the housing 26 . Furthermore, in order to transmit electric power from the power transmitting coil 13 to the power receiving coil 22 in a non-contact manner, it is preferable to arrange the power transmitting coil 13 and the power receiving coil 22 as close as possible. the

Even in the second embodiment, even if the distance between the power transmitting coil 13 and the power receiving coil 22 varies, the coupling coefficient k is hardly varied. the

In addition, examples of the power receiving device 20 include a storage battery device, an adapter, and a terminal body. In the case of a storage battery, a coil 22 and a rectifier circuit 24 are provided in the device, and a charging circuit and the storage battery are provided as a load circuit 25 to integrate them. to charge. In the case of an adapter, the coil and the rectifier circuit are integrated to form an adapter, and it is used as if connecting the terminal body and the adapter. In addition, when the power receiving device 20 is a terminal main body, it is a case where a coil and a rectifier circuit are provided inside the terminal to be integrated with the terminal. Examples of the terminal include a mobile phone, a smartphone, a handheld terminal, a mobile printer, a tablet computer, a notebook computer, and the like. the

According to the embodiments described above, it is possible to provide a power transmission device that can suppress fluctuations in the coupling coefficient k even when the distance between the resonance elements of the power transmission device 10 and the power reception device 20 fluctuates, and does not require impedance control. High power transmission efficiency can be maintained. the

Furthermore, although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in other various forms, and various omissions, replacements, and changes can be made as long as they do not depart from the gist of the invention. In addition, these embodiments and modifications thereof are included in the scope or gist of the invention, and are also included in the invention described in the scope of claims and the equivalent range thereof. the

third embodiment

Next, a third embodiment will be described with reference to FIG. 16 . In the third embodiment, the shape of the region 131 of the power transmission coil 13 is wired vertically or horizontally. the

Fourth embodiment

Next, a fourth embodiment will be described with reference to FIG. 17 . In the fourth embodiment, the shape of the region 131 of the power transmission coil 13 is wired vertically or horizontally and double reciprocated. Therefore, the wiring in the area 131 may also go back and forth multiple times. the

Fifth embodiment

Next, a fifth embodiment will be described with reference to FIG. 18 . In the fifth embodiment, the shape of the region 131 of the power transmission coil 13 may be repeated inwardly and then outwardly. Alternatively, wiring may be repeated toward the inside after being directed outward. Similar to the fourth embodiment, multiple round trips are also possible. the

Sixth embodiment

Next, a sixth embodiment will be described with reference to FIG. 19 . In the sixth embodiment, the shape of the region 131 of the power transmission coil 13 may be circular or angular. Similar to the fourth embodiment, multiple round trips are also possible. the

Seventh embodiment

Next, a seventh embodiment will be described with reference to FIG. 20 . In the seventh embodiment, the shape of the region 131 of the power transmission coil 13 may be reversed from the first round and directed toward the center point. Similar to the fourth embodiment, multiple round trips are also possible as shown in FIG. 21 . the

The power transmission device involved in the present invention can perform power transmission from the power transmission device to the power reception device through electromagnetic coupling in a non-contact manner, and the power transmission device includes the power transmission device and the power reception device, wherein , the power transmitting device includes: a power transmitting coil; and an AC power supply for supplying AC power to a resonant element including the power transmitting coil, and the power receiving device includes: a power receiving coil; for receiving power; and a rectifying circuit, rectifying AC power induced to a resonance element including the power receiving coil, one of the power transmitting coils or the power receiving coil, including a first coil pattern, having a forward wiring pattern and A balanced area constituted by a reversed wiring pattern, and the peripheral portion of the balanced area is formed in a planar shape, and the other coil in the power transmitting coil or the receiving coil includes a second coil pattern, which is connected to the balanced area. Corresponding and formed into a planar shape. the

As mentioned above, the embodiment of the present utility model has been described in detail, but as long as it does not deviate from the inventive points and effects of the present utility model, many modifications can be made, which will be obvious to those skilled in the art. Therefore, such modified examples are all included in the protection scope of the present invention. the

Claims (10)

1. A power transmission device having a power transmitting device and a power receiving device capable of transmitting power from the power transmitting device to the power receiving device in a non-contact manner by electromagnetic coupling, characterized in that, The power transmission device includes: power transmitting coils; and an AC power supply for supplying AC power to the resonant element including the power transmission coil, The receiving device includes: a power receiving coil; for receiving power; and a rectification circuit for rectifying the AC power induced to the resonance element including the power receiving coil, Wherein, one of the power transmitting coil and the power receiving coil includes a first coil pattern, has a balance region at a central portion, and is formed in a planar shape at a peripheral portion of the balance region, The other coil of the power transmitting coil and the power receiving coil includes a second coil pattern corresponding to the balance area and formed in a planar shape. 2. The power transmission device according to claim 1, wherein: The balance area is composed of a forward wiring pattern and a reverse wiring pattern. 3. The power transmission device according to claim 2, wherein: The second coil pattern has an outer dimension equal to or smaller than that of the balance area. 4. The power transmission device according to claim 3, wherein: The first coil pattern and the second coil pattern are formed on a substrate. 5. The power transmission device according to claim 4, wherein: The area of the balance area is 30%-50% of the outline area of the first coil pattern. 6. The power transmission device according to any one of claims 1 to 5, characterized in that, The power transmission coil and the power reception coil are formed in a polygonal shape. 7. The power transmission device according to any one of claims 1 to 5, characterized in that, The first coil pattern is provided on a peripheral portion of the balance area, and is composed of a plurality of patterns folded back from an outer edge portion. 8. A power transmission device that transmits power in a non-contact manner with respect to a power receiving device through electromagnetic coupling, characterized in that, The power transmission device includes a first coil pattern, has a balance region at a center, and is formed in a planar shape at a peripheral portion of the balance region. 9. A power receiving device that receives power transmitted from a power transmitting device in a non-contact manner through electromagnetic coupling, characterized in that, The power receiving device includes a first coil pattern, has a balance region at a center, and is formed in a planar shape at a peripheral portion of the balance region. 10. A coil device for a power transmission device for non-contact power transmission from a power transmitting coil to a power receiving coil through electromagnetic coupling, characterized in that, Either one of the power transmitting coil and the power receiving coil includes a coil pattern, has a balance area in the center, and is formed in a polygonal planar shape around the balance area.