JP5601152B2 - Wireless power transmission system and power transmission device - Google Patents

Description

  The present invention relates to a system for transmitting power wirelessly and a power transmission device.

  As a typical wireless power transmission system, a magnetic field coupling type power transmission system is known in which power is transmitted from a primary coil of a power transmission device to a secondary coil of a power reception device using a magnetic field. However, when power is transmitted by magnetic field coupling, since the magnitude of magnetic flux passing through each coil greatly affects the electromotive force, high accuracy is required for the relative positional relationship between the primary coil and the secondary coil. Moreover, since the coil is used, it is difficult to reduce the size of the apparatus.

  On the other hand, an electric field coupling type wireless power transmission system as disclosed in Patent Documents 1 and 2 is also known. In this system, power is transmitted from the coupling electrode of the power transmission apparatus to the coupling electrode of the power reception apparatus via an electric field. In this method, the relative positional accuracy of the coupling electrode is relatively loose, and the coupling electrode can be reduced in size and thickness.

  FIG. 1 is a diagram illustrating a basic configuration of a power transmission system disclosed in Patent Document 1. In FIG. This power transmission system includes a power transmission device and a power reception device. The power transmission device includes a high frequency high voltage generation circuit 1, a passive electrode 2, and an active electrode 3. The power receiving device includes a high frequency high voltage load circuit 5, a passive electrode 7, and an active electrode 6. Then, when the active electrode 3 of the power transmission device and the active electrode 6 of the power reception device come close to each other through the gap 4, the two electrodes are electrically coupled.

  The passive electrode of the power transmission device, the active electrode of the power transmission device, the active electrode of the power reception device, and the passive electrode of the power reception device are arranged in parallel to each other.

  In the power transmission system of Patent Literature 2, the power transmission device includes a first resonance circuit that resonates with an AC signal generated by the AC signal generation unit and a power feeding electrode. The power receiving apparatus includes a power receiving electrode that generates an electric signal, a second resonance circuit that resonates with the electric signal, a rectifying unit that generates DC power from the resonated electric signal, and a circuit load. The active electrode and the passive electrode of the power transmission device are provided on one plane, and the active electrode and the passive electrode of the power reception device are provided so as to face each other electrode at a predetermined interval. Further, in FIGS. 18 to 21 of Patent Document 2, the active electrode on the power receiving device side is constituted by a plurality of divided electrodes, and when the power receiving device is placed, the first and second active electrodes of the power transmitting device are opposed to each other. It is shown that the split electrode of the overlapping power receiving device is selectively operated as an active electrode.

Special table 2009-531009 JP 2009-296857 A

  In the power transmission system of Patent Document 1, the active electrodes of the power transmission device and the power reception device are brought close to each other to form a strong electric field between the electrodes, and the capacitance generated between the passive electrodes of the power transmission device and the power reception device is increased as much as possible. . Therefore, it is necessary to enlarge the passive electrode. If the passive electrode of the power transmission unit, the active electrode of the power transmission unit, the active electrode of the power reception unit, and the passive electrode of the power reception unit are arranged in the vertical direction, the stray capacitance tends to be excessive. Even in the power transmission system of Patent Document 2, since the active electrode and the passive electrode are arranged adjacent to each other, the stray capacitance between the active electrode and the circuit board arranged close to the passive electrode tends to be excessive. is there. For this reason, there is a problem that the degree of coupling is not large and the transmission efficiency is low.

  Moreover, in the power transmission system of Patent Document 2, it is necessary to provide many active electrodes on the power receiving device side, and the selection circuit has to be complicated.

  The present invention increases the power transmission efficiency by reducing the stray capacitance that does not contribute to power transmission without increasing the size of the device, and increases the degree of freedom of the orientation of the power receiving device relative to the power transmission device with a simple configuration. An object is to provide a wireless power transmission system and a power transmission device.

(1) A wireless power transmission system of the present invention includes a mounting surface on which a power receiving device is mounted, a power transmission circuit that generates a high frequency high voltage, a power transmission side active electrode to which the high frequency high voltage is applied, and a power transmission side passive. A power transmission device having an electrode;
A power receiving circuit, and a power receiving device having a power receiving side active electrode and a power receiving side passive electrode connected to the power receiving circuit,
A wireless power transmission system that transmits electric power from the power transmission device to the power reception device by electric field coupling between the power transmission side active electrode and the power reception side active electrode, and the power transmission side passive electrode and the power reception side passive electrode. In
The power transmission side active electrode includes a power transmission side first active electrode extending in a strip shape in the first direction through the center of the placement surface, and a second direction passing through the center of the placement surface and intersecting the first direction. A second active electrode on the power transmission side extending in a belt shape,
A switching circuit that switches supply of the high-frequency high voltage to the power transmission side first active electrode or the power transmission side second active electrode is provided.

  According to this structure, the stray capacitance that does not contribute to the power transmission is reduced, the power transmission efficiency is high, and the degree of freedom of the mounting direction of the power receiving device with respect to the power transmission device is high.

(2) For example, the power transmission side passive electrode is disposed on the opposite side of the power reception side active electrode and the power reception side passive electrode with the power transmission side first active electrode and the power transmission side second active electrode interposed therebetween, for example. . With this structure, the active electrode of the power transmission device and the active electrode of the power reception device can be coupled with a high voltage.

(3) The power transmission side first active electrode and the power transmission side second active electrode are orthogonal or substantially orthogonal. With this structure, the position freedom is improved with a simple structure, and the stray capacitance can be reduced.

(4) It is preferable that the shape of the power receiving side active electrode is a strip shape. As a result, the effect of reducing stray capacitance is great.

(5) For example, a protruding extension electrode is provided at a position near the power transmission side first active electrode to the power transmission side second active electrode and a position near the power transmission side second active electrode to the power transmission side first active electrode. A pattern is provided. With this structure, it is possible to secure a positional freedom in the oblique direction.

(6) The extended electrode pattern is, for example, a first protrusion protruding in the direction of 45 ° and −45 ° with respect to the direction extending along the power transmission side first active electrode from the center of the power transmission side first active electrode. And a second convex portion whose height from the center line of the power transmission side second active electrode is approximately ½ of the length of the short side of the power reception side active electrode.

  With this configuration, even when the power receiving device is opposed to the power transmitting device in an oblique direction, the degree of coupling can be improved without increasing the stray capacitance, and power can be transmitted with high efficiency.

(7) For example, when the long side of the power receiving side active electrode is arranged in a direction of 45 ° with respect to the direction in which the power transmitting side first active electrode extends, The area facing the power receiving side active electrode is larger than the area not facing, and the power receiving side active electrode does not face the second convex portion.

  With this configuration, the first active electrode on the power transmission side is turned on at a position in the oblique 45 ° direction, and the degree of coupling can be improved without increasing the stray capacitance, so that power can be transmitted with high efficiency.

(8) Further, for example, the area of the first protrusion is larger than the area of the second protrusion.

  According to the present invention, without increasing the size of the device, the stray capacitance that does not contribute to power transmission is reduced to increase power transmission efficiency, and the degree of freedom of the orientation of the power receiving device with respect to the power transmission device can be increased with a simple configuration. An enhanced wireless power transmission system and power transmission device can be configured.

FIG. 1 is a diagram illustrating a basic configuration of a power transmission system disclosed in Patent Document 1. In FIG. FIG. 2A is a plan view of the wireless power transmission system 401 according to the first embodiment, and FIG. 2B is a plan view thereof. 3A and 3B are plan views showing two typical mounting states of the power receiving device 201 with respect to the electric device 101 and switching states by the switching circuit 31. FIG. FIG. 4 is a circuit configuration diagram of the power transmission device 101 and the power reception device 201. FIG. 5 is a flowchart showing the processing contents of the control unit 33. FIG. 6A, FIG. 6B, and FIG. 6C are configuration examples for selectively using two active electrodes of the power transmission device. FIG. 7 is a plan view showing the shape of the active electrode of the power transmission device 103 according to the third embodiment. FIG. 8 is a plan view showing a typical positional relationship of the active electrodes of the power receiving device with respect to the first active electrode 12A and the second active electrodes 12B-1 and 12B-2 of the power transmitting device. 9A to 9G illustrate examples of the positional relationship of the active electrode of the power receiving device with respect to the first active electrode 12A, the second active electrodes 12B-1 and 12B-2 of the power transmitting device, and the first of the power transmitting device. It is a top view showing an example of which one of the 1 active electrode 12A or the 2nd active electrodes 12B-1 and 12B-2 is selected. FIG. 10A and FIG. 10B are plan views showing modifications of the first convex portion 12AP and the second convex portion 12BP.

<< First Embodiment >>
FIG. 2A is a plan view of the wireless power transmission system 401 according to the first embodiment, and FIG. 2B is a plan view thereof. The wireless power transmission system 401 includes a power transmission device 101 and a power reception device 201. However, in FIGS. 2A and 2B, each electrode inside the power transmitting device 101 and the power receiving device 201 is seen through (the housing is made transparent).

  The power transmitting apparatus 101 includes a passive electrode 11, a first active electrode 12 </ b> A, and a second active electrode 12 </ b> B, and the power receiving apparatus 201 includes a passive electrode 21 and an active electrode 22. In the wireless power transmission system 401, the first active electrode 12A or the second active electrode 12B of the power transmission apparatus 101 and the active electrode 22 of the power reception apparatus, and the passive electrode 11 of the power transmission apparatus 101 and the passive electrode 21 of the power reception apparatus 201 are connected. Electric power is transmitted from the power transmitting apparatus 101 to the power receiving apparatus 201 by electric field coupling.

  The upper surface of the casing of the power transmission device 101 is a placement surface 13 on which the power reception device 201 is placed. The first active electrode 12A passes through the center of the mounting surface 13 and extends in a strip shape in the first direction. The second active electrode 12B passes through the center of the mounting surface 13 and extends in a strip shape in a second direction orthogonal to the first direction in plan view.

  A power transmission circuit and a switching circuit 31 are provided in the casing of the power transmission device 101. The power transmission circuit applies a high-frequency high voltage between the first active electrode 12 </ b> A or the second active electrode 12 </ b> B and the passive electrode 11. The switching circuit selects either the first active electrode 12A or the second active electrode 12B.

  As shown in FIG. 2B, the passive electrode 11 of the power transmission device 101 includes the active electrode 22 and the power reception device of the power reception device 201 with the first active electrode 12A and the second active electrode 12B of the power transmission device 101 interposed therebetween. 201 is disposed on the opposite side of the passive electrode 21.

  The active electrode 22 of the power receiving device has a shape having a longitudinal direction, that is, a strip shape. The active electrode 22 of the power receiving apparatus 201 faces the first active electrode 12A or the second active electrode 12B of the power transmitting apparatus 101. The passive electrode 21 of the power receiving device 201 faces the passive electrode 11 of the power transmitting device 101. In this state, the active electrodes and the passive electrodes are electrically coupled. With this structure, the active electrode of the power transmission device and the active electrode of the power reception device can be coupled with a high voltage.

  FIGS. 3A and 3B are plan views showing two typical mounting states of the power receiving apparatus 201 with respect to the power transmitting apparatus 101 and switching states by the switching circuit 31. FIG. The power transmission circuit 111 generates a predetermined high-frequency high voltage, and the switching circuit 31 applies the output voltage of the power transmission circuit 111 to either the first active electrode 12A or the second active electrode 12B.

  As shown in FIG. 3A, in a state where the active electrode 22 of the power receiving device 201 is opposed to the first active electrode 12A of the power transmitting device 101, the switching circuit 31 selects the first active electrode 12A. As shown in FIG. 3B, in a state where the active electrode 22 of the power receiving device 201 is opposed to the second active electrode 12B of the power transmitting device 101, the switching circuit 31 selects the second active electrode 12B. In this manner, power transmission is possible regardless of whether the power receiving apparatus 201 is placed horizontally or vertically with respect to the power transmitting apparatus 101. Since the active electrode that is not selected by the switching circuit 31 is in an open state, no stray capacitance is generated between the passive electrode 11 of the power transmission device 101 and the passive electrode 21 of the power reception device 201. Therefore, a high degree of coupling can be maintained.

  Note that, at the intersection position of the first active electrode 12A and the second active electrode 12B, the electrode width may be narrowed only at the intersection position so that the opposing areas are as small as possible. Thus, stray capacitance generated between the first and second active electrodes 12A and 12B can be further suppressed.

  FIG. 4 is a circuit configuration diagram of the power transmission device 101 and the power reception device 201. In the power transmission circuit 111, the constant voltage power source 35 is a power source circuit that receives a commercial power source and generates, for example, a constant DC voltage (for example, DC 5V). The constant current power supply 36 is a power supply circuit that generates a constant direct current. The switching circuit 34 selects one of the constant voltage power supply 35 and the constant current power supply 36 and supplies it to the drive control circuit / detection circuit 32. The drive control circuit / detection circuit 32 uses a constant voltage power supply 35 or a constant current power supply 36 as a power supply to generate a high frequency voltage of, for example, 100 kHz to several tens of MHz, and also detects a voltage DCV supplied from the constant current power supply 36 and a constant voltage power supply. The current DCI supplied from 35 is detected. The controller 33 controls the drive control circuit / detection circuit 32 and the switching circuits 31 and 34 as described later.

  In the power receiving circuit 211 of the power receiving apparatus 201, a step-down circuit using, for example, a step-down transformer and an inductor is connected between the passive electrode 21 (see FIG. 2B) and the active electrode 22. A load circuit is connected to the secondary side of the step-down transformer. This load circuit is composed of a rectifying / smoothing circuit and a circuit of a device as a load. The circuit of the device serving as a load may include a secondary battery.

  For example, the power receiving apparatus 201 is an apparatus in which an internal secondary battery is charged by being placed on the power transmitting apparatus 101. Examples of portable electronic devices include a mobile phone, a notebook PC, and a digital camera. The power receiving apparatus 201 may be a charger or a power source that does not incorporate a secondary battery. In this case, the received power may be output to the outside to supply or charge another device.

FIG. 5 is a flowchart showing the processing contents of the control unit 33.
First, the switching circuit 34 is set to the constant current power source 36 side (S1). Further, the switching circuit 31 is set on the first active electrode 12A side (S2). Next, the drive circuit / detection circuit 32 is driven while sweeping the drive frequency (S3). Then, it is determined whether or not there is a maximum value of the DC voltage DCV (S4). If there is no local maximum, the same process is performed by switching to the second active electrode 12B side (S5 → S3).

  If the DCV has a maximum value, the frequency is set as the drive frequency (S6). Then, the switching circuit 34 is switched to the constant voltage power supply 35 side. Thus, power supply (power transmission) is started (S7).

  Thereafter, the drive current DCI is detected (S8). And it waits until drive current DCI falls below threshold value DCIth1 (S9-> S8 ...).

  If the drive current DCI falls below the threshold value DCIth1, the drive of the drive circuit / detection circuit 32 is stopped (S10).

  Thereafter, the process returns to step S1. As a result, the processes in and after step S1 are repeated. However, since the secondary battery of the power receiving apparatus is already fully charged, the determination condition in step S9 is satisfied. Therefore, it is not repeatedly charged.

  If the power receiving apparatus is removed and a power receiving apparatus that requires another charge is placed, the first active electrode or the second active electrode is selected by the procedure described above, and charging is performed by power transmission. .

  Note that the frequency of the AC voltage generated by the power transmission circuit 111 has a longer wavelength in the dielectric medium (that is, air) around the power transmission device 101 and the power reception device 201 than the size of the power transmission device 101 and the power reception device 201. There is a relationship. That is, power is transmitted by a quasi-electrostatic field. This increases power transmission efficiency because less energy is radiated (dispersed) in the form of electromagnetic radiation. In addition, the frequency of the AC voltage generated by the power transmission circuit 111 is set as high as possible in a range where the radiated electromagnetic wave energy is smaller than the electric field energy propagated from the power transmission apparatus 101 to the power reception apparatus 201. As a result, the transmission power is increased even though the respective areas of the power transmission device side active electrodes 12A and 12B, the power transmission device side passive electrode 11, the power reception device side active electrode 22, and the power reception device side passive electrode 21 are small. be able to. When the transmission power is the same, the voltage of the coupling electrode can be lowered. Therefore, it is possible to configure a power transmission system that is small and has high power transmission efficiency. The same applies to each of the second and subsequent embodiments.

<< Second Embodiment >>
FIG. 6A, FIG. 6B, and FIG. 6C are configuration examples for selectively using two active electrodes of the power transmission device.
In FIG. 6A, the power supply unit 37, the driving unit 32-1, and the boosting unit 32-2 are also used, and the output voltage of the boosting unit 32-2 is changed by the switching circuit 31 to the first active electrode 12A or the second active electrode 12B. It is comprised so that it may supply to. Here, the step-up unit 32-2 is, for example, a step-up transformer, and the drive unit 32-1 is a switching element that drives the primary side of the step-up transformer and a drive circuit for the switching element. The example in FIG. 6A corresponds to the configuration of the power transmission device 101 illustrated in FIG. That is, the power supply unit 37 corresponds to the constant voltage power supply 35, and the drive unit 32-1 and the booster unit 32-2 correspond to the drive circuit / detection circuit 32, respectively.

  According to the configuration shown in FIG. 6A, many circuit portions other than the first active electrode and the second active electrode can be shared, which is advantageous for downsizing and cost reduction.

  In FIG. 6B, the power supply unit 37 and the drive unit 32-1 are also used, and the booster units 32-2A and 32-2B are selectively driven by the switching circuit 38, and the output voltage is changed to the first active electrode 12A or the first active electrode 12A. 2 is configured to be supplied to the active electrode 12B.

  In FIG. 6C, the power supply unit 37 is also used, and the driving units 32-1A and 32-1B and the boosting units 32-2A and 32-2B are selectively driven by the switching circuit 39, and the output voltage is first active. It is configured to be supplied to the electrode 12A or the second active electrode 12B.

  The switching control of the switching circuits 31, 38, 39 is performed according to which of the first active electrode 12A or the second active electrode 12B faces the active electrode 22 of the power receiving device.

  As shown in FIG. 6 (B) or FIG. 6 (C), since there are two resonance systems in the configuration including two boosting units, it is important to prevent the resonance systems from interacting with each other. It is. Therefore, (1) the coupling between the active electrodes 12A and 12B is physically weakened. (2) The resonance frequency is intentionally shifted. This configuration is effective. In the configuration of (2), for example, when the primary side of the step-up transformer in the off-resonance system of the two resonance systems is opened, the LC resonance frequency (unnecessary resonance frequency) is determined by the impedance L of the boost transformer and the capacitance C of the coupling portion. ) Is determined. When short-circuited, the LC resonance frequency (unnecessary resonance frequency) is determined by the leakage inductance component L of the step-up transformer and the capacitance C of the coupling portion. In either case, the operating frequency of the on-side resonance system of the two resonance systems may be set so as not to be close to the unnecessary resonance frequency.

<< Third Embodiment >>
FIG. 7 is a plan view showing the shape of the active electrode of the power transmission device 103 according to the third embodiment. The power transmission device 103 includes a first active electrode 12A and second active electrodes 12B-1 and 12B-2. The second active electrodes 12B-1 and 12B-2 are separated, but the same potential is applied during selection. A thin line portion 12AS is formed in a portion of the first active electrode 12A where the tip portions of the two second active electrodes 12B-1 and 12B-2 face each other. Four first convex portions 12AP are formed at positions close to the second active electrodes 12B-1 and 12B-2 of the first active electrode 12A. Further, a second convex portion 12BP is formed at a position where the second active electrodes 12B-1 and 12B-2 are close to the first active electrode 12A.

  The first protrusion 12AP protrudes in the direction of 45 ° and −45 ° with respect to the direction extending along the first active electrode 12A from the center of the first active electrode 12A (position of the thin line portion 12AS). The height of the second protrusion 12BP from the center line of the second active electrodes 12B-1 and 12B-2 (in the line width direction) is about ½ of the length of the short side of the active electrode of the power receiving device described later. It is. In this example, since the first active electrode 12A is selected in a wider angle range, the area of the first convex portion 12AP provided on the first active electrode 12A is the second active electrodes 12B-1, 12B-. 2 is larger than the area of the second convex portion 12BP provided in 2.

  Since the second active electrode is thus separated into the two active electrodes 12B-1 and 12B-2, the first active electrode 12A and the second active electrodes 12B-1 and 12B-2 are arranged on the same plane (same layer). Can be formed. Therefore, each coupling capacity is determined by the overlapping area of the first active electrode and the second active electrode on the power transmission side and the active electrode on the power receiving side. Therefore, compared with the case where the first active electrode and the second active electrode on the power transmission side are formed on different planes, electric power can be transmitted with high efficiency without increasing the stray capacitance.

FIG. 8 is a plan view showing a typical positional relationship of the active electrodes of the power receiving device with respect to the first active electrode 12A and the second active electrodes 12B-1 and 12B-2 of the power transmitting device.
When the active electrode 22 of the power receiving device is horizontally arranged as indicated by 22 (T) in the figure, the active electrode 22 of the power receiving device is the second active electrodes 12B-1, 12B-2 and the second active electrode of the power transmitting device. Capacitance is generated between the convex portion 12BP and electric field coupling occurs. At this time, an unnecessary stray capacitance hardly occurs between the active electrode 22 of the power receiving device and the first active electrode 12A and the first convex portion 12AP of the power transmitting device. Further, since the portion of the first active electrode 12A intersecting the second active electrodes 12B-1 and 12B-2 is the thin line portion 12AS, the stray capacitance generated between the thin line portion 12AS and the active electrode 22 of the power receiving device is Small enough.

  When the active electrode 22 of the power receiving device is vertically arranged as indicated by 22 (L) in the figure, the active electrode 22 of the power receiving device is the first active electrode 12A of the power transmitting device, the thin wire portion 12AS, and the first protrusion. Capacitance is generated between the portion 12AP and electric field coupling occurs. At this time, the active electrode 22 of the power receiving device hardly generates unnecessary stray capacitance between the second active electrodes 12B-1 and 12B-2 and the second convex portion 12BP of the power transmitting device.

  When the active electrode 22 of the power receiving device is arranged obliquely as indicated by 22 (S) in the figure, the active electrode 22 of the power receiving device is the thin line portion 12AS and the first convex portion of the first active electrode 12A of the power transmitting device. Capacitance is generated between the 12 AP and electric field coupling. At this time, the active electrode 22 of the power receiving device hardly generates unnecessary stray capacitance between the second active electrodes 12B-1 and 12B-2 and the second convex portion 12BP of the power transmitting device.

9A to 9G illustrate examples of the positional relationship of the active electrode of the power receiving device with respect to the first active electrode 12A, the second active electrodes 12B-1 and 12B-2 of the power transmitting device, and the first of the power transmitting device. It is a top view showing an example of which one of the 1 active electrode 12A or the 2nd active electrodes 12B-1 and 12B-2 is selected.
FIG. 9A corresponds to the vertical placement in FIG. 8 (in this example, the longitudinal direction of the power receiving device 201 is horizontal, so that it is expressed by the orientation of the power receiving device), and FIG. 9D is the same as FIG. 9G corresponds to the horizontal placement in FIG. 8 (the longitudinal direction of the power receiving apparatus 201 is vertical, and thus the vertical placement in terms of the orientation of the power receiving apparatus). The orientation of the active electrode of the power receiving apparatus with respect to the first active electrode 12A and the second active electrodes 12B-1 and 12B-2 of the power transmitting apparatus changes from the horizontal state shown in FIG. 9A to the slant 45 shown in FIG. 9D. In the angle range up to degrees, the first active electrode 12A is selected. In addition, the second active electrodes 12B-1 and 12B-2 are selected in the angle range from the state shown in FIG. 9E to the state shown in FIG. .

  When the state of FIG. 9A is expressed as 0 degree, the state of FIG. 9A is expressed as 45 degrees, and the state of FIG. 9G is expressed as 90 degrees, the power receiving device has an angular range of 0 degrees to 45 degrees. Capacitance is generated between the active electrode 22, the first active electrode 12A of the power transmission apparatus 101, and the first convex portion (12AP in FIG. 7), and the electric field coupling occurs. At this time, an unnecessary stray capacitance generated between the active electrode 22 of the power receiving device and the second active electrodes 12B-1 and 12B-2 and the second convex portion 12BP of the power transmitting device is small. Further, in the angle range from more than 45 degrees to 90 degrees, the active electrode 22 of the power receiving device, the second active electrodes 12B-1, 12B-2 of the power transmitting device 101, and the second convex portion (12BP in FIG. 7). ) And an electric field coupling occurs between them. At this time, an unnecessary stray capacitance generated between the active electrode 22 of the power receiving device and the first active electrode 12A and the first convex portion 12AP of the power transmitting device is small.

  In the example shown in FIG. 9, the angle range from 0 degrees to 90 degrees is shown. However, since the shapes of the first protrusion 12AP and the second protrusion 12BP are bilaterally symmetrical, The same applies to the angle range up to 180 degrees. That is, in the angle range from 90 degrees to 135 degrees, the active electrode 22 of the power receiving device, the second active electrodes 12B-1, 12B-2 of the power transmitting device 101, and the second convex portion (12BP in FIG. 7). ) And an electric field coupling occurs between them. Further, in an angle range of more than 135 degrees to 180 degrees, there is electrostatic between the active electrode 22 of the power receiving apparatus, the first active electrode 12A of the power transmitting apparatus 101, and the first convex portion (12AP in FIG. 7). Capacitance is generated and electric field coupling occurs.

  The shapes of the first convex portion 12AP and the second convex portion 12BP provided on the active electrode of the power transmission device shown in FIG. 7 are not limited to those shown in FIG. For example, as shown to FIG. 10 (A), the 2nd convex part 12BP may be the same shape as 1st convex part 12AP. That is, the second convex portion 12BP is 45 ° with respect to the direction extending along the second active electrodes 12B-1 and 12B-2 from the vicinity of the position where the second active electrodes 12B-1.12B-2A face each other. The shape may protrude in the direction of −45 °.

  Incidentally, as shown in FIG. 10B, the height (line width direction) of the first protrusion 12AP from the center line of the first active electrode 12A is the length of the short side of the active electrode of the power receiving device. When the shape is about 1/2, the stray capacitance increases. That is, in FIG. 10B, when the active electrode 22 of the power receiving device is arranged obliquely as indicated by 22 (S) in the figure, the hatched region becomes a stray capacitance forming portion that does not contribute to coupling. Therefore, the shape of the first convex portion or the second convex portion so that the stray capacitance that does not contribute to the coupling between the active electrode of the power transmitting device and the active electrode 22 of the power receiving device selected in the 45 ° oblique arrangement state does not increase. It is important to define

  The first active electrode 12A may be separated into two without the thin line portion 12AS shown in FIG.

DESCRIPTION OF SYMBOLS 11 ... Power transmission apparatus side passive electrode 12A ... Power transmission apparatus side 1st active electrode 12AP ... 1st convex part 12AS ... Thin wire | line part 12B ... Power transmission apparatus side 2nd active electrode 12BP ... 2nd convex part 13 ... Mounting surface 21 ... Power-receiving-device-side passive electrode 22 ... Power-receiving-device-side active electrodes 31, 34 ... Switch circuit 34 ... Switch circuit 35 ... Constant voltage power source 36 ... Constant current power sources 38, 39 ... Switch circuits 101, 103 ... Power transmitting device 111 ... Power transmitting circuit 201 ... Power receiving device 211 ... Power receiving circuit 401 ... Wireless power transmission system

Claims (12)

A mounting surface on which the power receiving device is mounted; a power transmission circuit that generates a high-frequency high voltage; a power transmission device having a power-transmission-side active electrode and a power-transmission-side passive electrode to which the high-frequency high voltage is applied;
A power receiving circuit, and a power receiving device having a power receiving side active electrode and a power receiving side passive electrode connected to the power receiving circuit,
A wireless power transmission system that transmits electric power from the power transmission device to the power reception device by electric field coupling between the power transmission side active electrode and the power reception side active electrode, and the power transmission side passive electrode and the power reception side passive electrode. In
The power transmission side active electrode includes a power transmission side first active electrode extending in a strip shape in the first direction through the center of the placement surface, and a second direction passing through the center of the placement surface and intersecting the first direction. A second active electrode on the power transmission side extending in a belt shape,
A wireless power transmission system comprising a switching circuit for switching supply of the high-frequency high voltage to the power transmission side first active electrode or the power transmission side second active electrode.   The said power transmission side passive electrode is arrange | positioned on the opposite side of the said power reception side active electrode and the said power reception side passive electrode on both sides of the said power transmission side 1st active electrode and the said power transmission side 2nd active electrode. Wireless power transmission system. Wherein the power transmission side first active electrode and the power-transmitting-side second active electrode are interlinked directly, the wireless power transmission system according to claim 1 or 2.   The wireless power transmission system according to claim 1, wherein the power receiving side active electrode has a strip shape. The power transmission side first active electrode and the power transmission side are disposed at a position close to the power transmission side second active electrode of the power transmission side first active electrode and a position adjacent to the power transmission side first active electrode of the power transmission side second active electrode. The wireless power transmission system according to any one of claims 2 to 4, further comprising a protruding extended electrode pattern disposed in the same plane direction as a plane formed by the side second active electrode . The extended electrode pattern includes a first convex portion projecting in a direction of 45 ° and −45 ° with respect to a direction extending from the center of the power transmission side first active electrode along the power transmission side first active electrode, and a power transmission side and a second protrusion height from the center line is 1/2 of the length of the short side of the power receiving side active electrode of the second active electrode, the wireless power transmission system according to claim 5.   When the long side of the power reception side active electrode is arranged in a direction of 45 ° with respect to the direction in which the power transmission side first active electrode extends, the power reception side active electrode of the first convex portion The wireless power transmission system according to claim 6, wherein an area facing the first active electrode is larger than an area not facing the first active electrode, and the power receiving side active electrode does not face the second convex portion.   The wireless power transmission system according to claim 6 or 7, wherein an area of the first convex portion is larger than an area of the second convex portion. A mounting surface on which the power receiving device is mounted; a power transmission circuit that generates a high-frequency high voltage; a power transmission device having a power-transmission-side active electrode and a power-transmission-side passive electrode to which the high-frequency high voltage is applied;
And a power receiving device having a power receiving side active electrode and a power receiving side passive electrode connected to the power receiving circuit, the power transmitting side active electrode and the power receiving side active electrode, and the power transmitting side passive electrode. And the power receiving side passive electrode, respectively, and a power transmission device used in a wireless power transmission system for transmitting power from the power transmission device to the power receiving device,
The power transmission side active electrode includes a power transmission side first active electrode extending in a strip shape in the first direction through the center of the placement surface, and a second direction passing through the center of the placement surface and intersecting the first direction. A second active electrode on the power transmission side extending in a belt shape,
The power transmission apparatus provided with the switching circuit which switches supply of the said high frequency high voltage to the said power transmission side 1st active electrode or the said power transmission side 2nd active electrode.   The said power transmission side passive electrode is arrange | positioned on the opposite side of the said power reception side active electrode and the said power reception side passive electrode on both sides of the said power transmission side 1st active electrode and the said power transmission side 2nd active electrode. Power transmission device.   The power transmission device according to claim 9 or 10, wherein the power receiving side active electrode has a strip shape.   The power transmission side second active electrode is separated into first and second electrode portions at the center of the mounting surface, and the power transmission side first active electrode and the first and second electrode portions are coplanar. The power transmission device according to any one of claims 9 to 11, wherein the power transmission device is formed.

Images