WO2025258295A1 - Power transmitter, power reception terminal, wireless power supply system, and control method - Google Patents

Abstract

The present disclosure addresses the problem of providing a power transmitter, a power reception terminal, a wireless power supply system, and a control method capable of catering to various needs. A power transmitter (1) is provided with a plurality of power transmission coils (10), a plurality of power transmission circuits (11), a switch (13), and a controller (14). Each of the plurality of power transmission coils (10) transmits power in a contactless manner. The plurality of power transmission circuits (11) supply power to the plurality of power transmission coils (10), respectively. The switch (13) switches connections between the plurality of power transmission coils (10) and the plurality of power transmission circuits (11). The controller (14) controls the switch (13).

Description

Power transmitter, power receiving terminal, wireless power supply system, and control method

This disclosure generally relates to a power transmitter, a power receiving terminal, a wireless power supply system, and a control method, and more specifically to a power transmitter equipped with a power transmitting coil, a power receiving terminal equipped with a power receiving coil, a wireless power supply system equipped with a power transmitter and a power receiving terminal, and a method for controlling a switch.

An example of a wireless power transmission system (wireless power supply system) is described in Patent Document 1. The wireless power transmission system described in Patent Document 1 includes a power transmission device having a power transmission coil and a power receiving device having a power receiving coil. The power transmission device supplies power to the power receiving device contactlessly through electromagnetic induction between the power transmission coil and the power receiving coil.

The power transmission device includes a power transmission coil and a power transmission circuit that supplies AC power to the power transmission coil. The power transmission coil is composed of multiple power transmission coil elements and a switch circuit. The switch circuit selects one of the multiple power transmission coil elements and electrically connects the selected power transmission coil element to the power transmission circuit.

The power transmitter device of the wireless power transmission system described in Patent Document 1 supplies power to the power receiving device contactlessly from one of multiple power transmitter coil elements, so it is not possible to use the remaining power transmitter coil elements, for example. Therefore, it is difficult for the power transmitter device of the wireless power transmission system described in Patent Document 1 to meet the diverse needs of users.

JP 2015-111996 A

The purpose of this disclosure is to provide a power transmitter, a power receiving terminal, a wireless power supply system, and a control method that can meet a variety of needs.

A power transmitter according to one aspect of the present disclosure includes multiple power transmission coils, multiple power transmission circuits, a switch, and a controller. Each of the multiple power transmission coils transmits power contactlessly. The multiple power transmission circuits supply the power to the multiple power transmission coils, respectively. The switch switches the connections between the multiple power transmission coils and the multiple power transmission circuits. The controller controls the switch.

A power receiving terminal according to one aspect of the present disclosure includes at least one receiving coil and at least one receiving circuit. The at least one receiving coil receives the power transmitted from at least one transmitting coil among the plurality of transmitting coils of the power transmitter. The at least one receiving circuit converts the power received by the at least one receiving coil into output power.

A wireless power supply system according to one aspect of the present disclosure includes the power transmitter and the power receiving terminal. The controller controls the switch based on the number of power receiving coils and the number of power receiving circuits in the power receiving terminal.

A control method according to one aspect of the present disclosure is a control method for a switch that switches connections between multiple power transmission coils and multiple power transmission circuits. The control method includes a first control process, a second control process, and a third control process. In the first control process, when the power receiving terminal has multiple power receiving coils and the power receiving terminal has one power receiving circuit, the switch is controlled so that the same number of power transmission coils as the number of power receiving coils among the multiple power transmission coils are connected to one power transmission circuit among the multiple power transmission circuits. In the second control process, when the number of power receiving coils and the number of power receiving circuits are the same and there are multiple power receiving circuits, the switch is controlled so that the multiple power transmission coils and the multiple power transmission circuits are connected one-to-one. In the third control process, when there is one power receiving coil and one power receiving circuit, the switch is controlled so that one power transmitting coil of the multiple power transmitting coils is connected to one power transmitting circuit of the multiple power transmitting circuits.

FIG. 1 is a configuration diagram showing an example of use of a wireless power supply system according to the first embodiment. FIG. 2 is a configuration diagram of a power transmission circuit of a power transmitter in the wireless power feeding system. FIG. 3 is a configuration diagram of a power receiving circuit of a power receiving terminal of the wireless power feeding system. FIG. 4 is an exploded perspective view of the power transmitter of the wireless power feeding system. FIG. 5 is an exploded perspective view showing a part of a main body of the power transmitter of the wireless power feeding system. FIG. 6 is a plan view of a mobile system and a housing of the power transmitter of the wireless power feeding system. FIG. 7 is a configuration diagram showing another example of use of the wireless power supply system. FIG. 8 is a flowchart illustrating the operation of the power transmitter in the wireless power feeding system. FIG. 9 is a perspective view of a mobile system and a housing of a power transmitter in a wireless power feeding system according to a first modification of the first embodiment. FIG. 10 is a schematic configuration diagram of a power transmitter in the wireless power feeding system. FIG. 11 is a configuration diagram of a power receiving circuit of a power receiving terminal of a wireless power feeding system according to a second modification of the first embodiment. FIG. 12 is a configuration diagram of a power receiving circuit of a power receiving terminal of a wireless power feeding system according to a third modification of the first embodiment. FIG. 13 is a configuration diagram of a power receiving terminal of a wireless power feeding system according to a fourth modification of the first embodiment. FIG. 14 is a configuration diagram of a phase circuit of the power receiving terminal of the wireless power feeding system. FIG. 15 is a configuration diagram showing a usage example of a wireless power feeding system according to a fifth modification of the first embodiment. FIG. 16 is a configuration diagram illustrating an example of use of the wireless power supply system according to the second embodiment. FIG. 17 is a configuration diagram showing another example of use of the wireless power feeding system. FIG. 18 is a flowchart illustrating the operation of the power transmitter in the wireless power feeding system.

Below, wireless power supply systems according to embodiments 1 and 2 will be described with reference to the drawings. The configurations described in the following embodiments are merely examples of the present disclosure. The present disclosure is not limited to the following embodiments, and various modifications are possible depending on the design, etc., as long as the effects of the present disclosure can be achieved.

(Embodiment 1)
Hereinafter, a wireless power supply system 3 according to the first embodiment will be described with reference to FIGS.

(1) Wireless Power Supply System As shown in Fig. 1 , the wireless power supply system 3 includes a power transmitter 1 and a power receiving terminal 2. The wireless power supply system 3 supplies power from the power transmitter 1 to the power receiving terminal 2 in a contactless manner.

(2) Components of the Wireless Power Supply System (2.1) Power Transmitter The power transmitter 1 includes, for example, a plurality of (two in the example of FIG. 1 ) power transmission coils 10, a plurality of (two in the example of FIG. 1 ) power transmission circuits 11, a plurality of (two in the example of FIG. 1 ) power supply circuits 12, a switch 13, and a controller 14. The plurality of power transmission coils 10 include a first power transmission coil 10a and a second power transmission coil 10b. The plurality of power transmission circuits 11 include a first power transmission circuit 11a and a second power transmission circuit 11b. The plurality of power supply circuits 12 include a first power supply circuit 12a and a second power supply circuit 12b. Furthermore, as shown in FIG. 4 , for example, the power transmitter 1 includes a main body 40 and a sensor sheet 50.

(2.1.1) Power Transmission Coil The first power transmission coil 10a shown in FIG. 1 transmits electric power (AC power) in a wireless manner. That is, the first power transmission coil 10a supplies electric power to a power supply target (in the example of FIG. 1, the power receiving terminal 2) in a wireless manner. The first power transmission coil 10a has, for example, a circular shape in a planar view. The first power transmission coil 10a is, for example, a spiral coil. AC power is supplied to the first power transmission coil 10a from the first power transmission circuit 11a. Note that the term "spiral coil" refers to a coil (planar coil) in which a conductor wire is wound in a spiral shape in a planar view.

The second power transmission coil 10b has the same shape and function as the first power transmission coil 10a. A detailed description of the second power transmission coil 10b will be omitted.

(2.1.2) Power Transmission Circuit The first power transmission circuit 11a supplies AC power to the first power transmission coil 10a. The first power transmission circuit 11a can also supply AC power to the second power transmission coil 10b. The first power transmission circuit 11a is electrically connected to the first power transmission coil 10a. The first power transmission circuit 11a is also electrically connected to the second power transmission coil 10b via a switch 13.

The first power transmission circuit 11a converts DC power from the first power supply circuit 12a into AC power. The first power transmission circuit 11a is, for example, an inverter. As shown in FIG. 2, the first power transmission circuit 11a includes a capacitor C11 and four switching elements Q11 to Q14. Capacitor C11 is connected in parallel to the first power supply circuit 12a. Switching element Q11 and switching element Q12 are connected in series with each other. Switching element Q11 and switching element Q12, which are connected in series with each other, are connected in parallel to capacitor C11. Switching element Q13 and switching element Q14 are connected in series with each other. Switching element Q13 and switching element Q14, which are connected in series with each other, are connected in parallel to switching element Q11 and switching element Q12, which are connected in series with each other.

Each of the four switching elements Q11 to Q14 is, for example, a MOSFET (Metal-Oxide-Semiconductor Field Effect Transistor). Each of the four switching elements Q11 to Q14 has a first main terminal, a second main terminal, and a control terminal. In the following, to facilitate understanding of the description of the embodiment, the first main terminal will be referred to as the drain terminal, the second main terminal as the source terminal, and the control terminal as the gate terminal.

The drain terminal of switching element Q11 is electrically connected to the source terminal of switching element Q12 via capacitor C11. The gate terminal of switching element Q11 is electrically connected to controller 14 (see Figure 1). The source terminal of switching element Q11 is electrically connected to the drain terminal of switching element Q12. The gate terminal of switching element Q12 is electrically connected to controller 14.

The drain terminal of switching element Q13 is electrically connected to the drain terminal of switching element Q11. The gate terminal of switching element Q13 is electrically connected to controller 14. The source terminal of switching element Q13 is electrically connected to the drain terminal of switching element Q14. The gate terminal of switching element Q14 is electrically connected to controller 14. The source terminal of switching element Q14 is electrically connected to the source terminal of switching element Q12.

The second power transmission circuit 11b shown in FIG. 1 is capable of supplying AC power to the second power transmission coil 10b. The second power transmission circuit 11b is electrically connected to the second power transmission coil 10b via a switch 13. The second power transmission circuit 11b is, for example, an inverter. The second power transmission circuit 11b has the same configuration and function as the first power transmission circuit 11a. A detailed description of the second power transmission circuit 11b will be omitted.

(2.1.3) Power Supply Circuit The first power supply circuit 12a supplies DC power to the first power transmission circuit 11a. The first power supply circuit 12a is electrically connected to the first power transmission circuit 11a. The first power supply circuit 12a is also electrically connected to, for example, an external power supply (not shown). The first power supply circuit 12a is, for example, an AC/DC converter. The external power supply is, for example, a commercial power supply.

The second power supply circuit 12b supplies DC power to the second power transmission circuit 11b. The second power supply circuit 12b is electrically connected to the second power transmission circuit 11b. The second power supply circuit 12b is also electrically connected to, for example, the external power supply. The second power supply circuit 12b is, for example, an AC/DC converter.

(2.1.4) Switch The switch 13 switches the connection between the multiple power transmitting coils 10 (the first power transmitting coil 10a and the second power transmitting coil 10b) and the multiple power transmitting circuits 11 (the first power transmitting circuit 11a and the second power transmitting circuit 11b). The switch 13 is, for example, a double-pole double-throw switch. As shown in FIG. 1 , for example, the switch 13 includes a pair of first connection terminals 4a, 4b, a pair of second connection terminals 5a, 5b, and a pair of third connection terminals 6a, 6b.

The pair of first connection terminals 4a, 4b are electrically connected to the first power transmission circuit 11a. More specifically, the first connection terminal 4a is electrically connected to the connection point 7b (see FIG. 2) between the switching elements Q13 and Q14 of the first power transmission circuit 11a. The first connection terminal 4b shown in FIG. 1 is electrically connected to the connection point 7a (see FIG. 2) between the switching elements Q11 and Q12 of the first power transmission circuit 11a. Furthermore, the pair of first connection terminals 4a, 4b are electrically connected to the first power transmission coil 10a, as shown in FIG. 1. More specifically, the first connection terminal 4a is electrically connected to the first connection terminal 4b via the first power transmission coil 10a.

The pair of second connection terminals 5a, 5b are electrically connected to the second power transmission circuit 11b. More specifically, the second connection terminal 5a is electrically connected to the connection point 7b (see Figure 2) between the switching elements Q13 and Q14 of the second power transmission circuit 11b. The second connection terminal 5b shown in Figure 1 is electrically connected to the connection point 7a (see Figure 2) between the switching elements Q11 and Q12 of the second power transmission circuit 11b.

As shown in FIG. 1, the pair of third connection terminals 6a, 6b are electrically connected to the second power transmission coil 10b. More specifically, the third connection terminal 6a is electrically connected to the third connection terminal 6b via the second power transmission coil 10b.

The switch 13 is controlled by the controller 14 to switch between a first connection state and a second connection state. The first connection state is a state in which the pair of first connection terminals 4a, 4b and the pair of third connection terminals 6a, 6b are electrically connected. The second connection state is a state in which the pair of second connection terminals 5a, 5b and the pair of third connection terminals 6a, 6b are electrically connected.

(2.1.5) Controller The controller 14 controls the multiple power transmission circuits 11. The controller 14 also controls the switch 13. The controller 14 is realized, for example, by a computer system having one or more processors and one or more memories. That is, the functions of the controller 14 are realized by the one or more processors executing a program recorded in the memory. The program may be pre-recorded in the memory, or may be provided via a telecommunications line such as the Internet, or may be recorded on a non-transitory recording medium such as a memory card and provided.

The controller 14 controls the on/off of the four switching elements Q11 to Q14 in the first power transmission circuit 11a. This allows the first power transmission circuit 11a to convert DC power from the first power supply circuit 12a into AC power and supply the AC power to the first power transmission coil 10a. The controller 14 also controls the on/off of the four switching elements Q11 to Q14 in the second power transmission circuit 11b. This allows the second power transmission circuit 11b to convert DC power from the second power supply circuit 12b into AC power and supply the AC power to the second power transmission coil 10b. The control of the switch 13 by the controller 14 will be described later.

(2.1.6) Main Body Unit The main body unit 40 shown in Fig. 4 has, for example, a function of moving the multiple power transmitting coils 10 and a function of detecting the position of a power receiving coil 20 (described later) in the power receiving terminal 2. Specifically, as shown in Fig. 5, for example, the main body unit 40 has a housing 48, a movement system 41, and a position detection device 42.

The housing 48 is box-shaped (e.g., rectangular box-shaped) with one side open. The housing 48 houses, for example, multiple power transmission coils 10, multiple power transmission circuits 11, multiple power supply circuits 12, a switch 13, a controller 14, and a movement system 41. Note that the multiple power transmission circuits 11, multiple power supply circuits 12, switches 13, and controller 14 are not shown in Figures 5 and 6.

In the following, as shown in Figures 5 and 6, an orthogonal coordinate system having three mutually orthogonal axes, the X-axis, the Y-axis, and the Z-axis, will be defined, and in particular, the axis along the winding axis direction of the multiple power transmission coils 10 will be referred to as the Z-axis. The X-axis, the Y-axis, and the Z-axis are all imaginary axes, and the arrows indicating "X," "Y," and "Z" in the drawings are merely used for the purpose of explanation and do not have any physical substance. Furthermore, the X-axis, the Y-axis, and the Z-axis directions are not intended to limit the orientation of the main body 40 when in use.

The movement system 41 shown in FIG. 5 is configured to move the first power transmission coil 10a and the second power transmission coil 10b independently. More specifically, the movement system 41 is configured to move the first power transmission coil 10a and the second power transmission coil 10b independently in the X-axis direction and the Y-axis direction. In short, the movement system 41 is a mechanism for moving multiple power transmission coils 10, a so-called moving coil type mechanism.

As shown in FIG. 6, the movement system 41 includes, for example, a plurality of (two in the example of FIG. 6) pedestals 16, a plurality of (two in the example of FIG. 6) X-axis rails 46, and a plurality of (two in the example of FIG. 6) Y-axis rails 45. The movement system 41 also includes a plurality of (two in the example of FIG. 6) X-axis drive units 47, a plurality of (two in the example of FIG. 6) Y-axis drive units 49, and a plurality of (four in the example of FIG. 6) support bases 55. The plurality of pedestals 16 include a first pedestal 16a and a second pedestal 16b. The plurality of X-axis rails 46 include a first X-axis rail 46a and a second X-axis rail 46b. The plurality of Y-axis rails 45 include a first Y-axis rail 45a and a second Y-axis rail 45b. The multiple X-axis drive units 47 include a first X-axis drive unit 47a and a second X-axis drive unit 47b. The multiple Y-axis drive units 49 include a first Y-axis drive unit 49a and a second Y-axis drive unit 49b. Note that the multiple X-axis drive units 47 and the multiple Y-axis drive units 49 are not shown in Figure 5.

As shown in FIG. 6, the first power transmission coil 10a is disposed on the first pedestal 16a. The first pedestal 16a is, for example, a rectangular plate. The first pedestal 16a is attached to the first Y-axis rail 45a so as to be movable in the Y-axis direction of the housing 48. The second power transmission coil 10b is disposed on the second pedestal 16b. The second pedestal 16b is, for example, a rectangular plate. The second pedestal 16b is attached to the second Y-axis rail 45b so as to be movable in the Y-axis direction of the housing 48.

The multiple X-axis rails 46 (first X-axis rail 46a and second X-axis rail 46b) are arranged, for example, side by side in the Y-axis direction of the housing 48, and are arranged inside the housing 48 along the X-axis direction of the housing 48. Each X-axis rail 46 has an elongated shape with a length in the X-axis direction longer than the length in the Y-axis direction.

The multiple Y-axis rails 45 (first Y-axis rail 45a and second Y-axis rail 45b) are, for example, arranged side by side in the X-axis direction of the housing 48, and are arranged within the housing 48 along the Y-axis direction of the housing 48. Each Y-axis rail 45 has an elongated shape such that the length in the Y-axis direction is longer than the length in the X-axis direction. The multiple Y-axis rails 45 are connected on multiple X-axis rails 46 so as to be movable in the X-axis direction of the housing 48. More specifically, the first Y-axis rail 45a is connected on multiple X-axis rails 46 so as to be movable in the X-axis direction of the housing 48. The second Y-axis rail 45b, like the first Y-axis rail 45a, is connected on multiple X-axis rails 46 so as to be movable in the X-axis direction of the housing 48.

The first X-axis drive unit 47a is held by the first Y-axis rail 45a and moves the first Y-axis rail 45a along the X-axis direction of the housing 48. The second X-axis drive unit 47b is held by the second Y-axis rail 45b and moves the second Y-axis rail 45b along the X-axis direction of the housing 48.

The first Y-axis drive unit 49a moves the first pedestal 16a, which is movably mounted on the first Y-axis rail 45a, along the Y-axis direction of the housing 48. The second Y-axis drive unit 49b moves the second pedestal 16b, which is movably mounted on the second Y-axis rail 45b, along the Y-axis direction of the housing 48.

The movement system 41 has multiple rack-and-pinion mechanisms. Each X-axis rail 46 is a rack with multiple teeth aligned in the X-axis direction of the housing 48. The first X-axis rail 46a is supported by two of the multiple (four in the example of Figure 6) support bases 55 fixed inside the housing 48. The second X-axis rail 46b is supported by the remaining two of the multiple support bases 55 fixed inside the housing 48.

The first X-axis drive unit 47a includes a pinion (gear) 471 that meshes with the rack that constitutes the second X-axis rail 46b, and a motor 472 that is held by the first Y-axis rail 45a and rotates the pinion 471. The pinion 471 is connected to the rotation shaft of the motor 472.

The second X-axis drive unit 47b includes a pinion 473 that meshes with the rack that constitutes the second X-axis rail 46b, and a motor 474 that is held by the second Y-axis rail 45b and rotates the pinion 473. The pinion 473 is connected to the rotation shaft of the motor 474.

Each Y-axis rail 45 has a rack 451 with multiple teeth aligned in the Y-axis direction of the housing 48, and a slider 452 adjacent to the rack 451. Each slider 452 slidably holds the corresponding base 16.

The first Y-axis drive unit 49a includes a pinion 491 that meshes with the rack 451 of the first Y-axis rail 45a, and a motor 492 that is held by the first base 16a and rotates the pinion 491. The pinion 491 is connected to the rotation shaft of the motor 492.

The second Y-axis drive unit 49b includes a pinion 493 that meshes with the rack 451 of the second Y-axis rail 45b, and a motor 494 that is held by the second base 16b and rotates the pinion 493. The pinion 493 is connected to the rotation shaft of the motor 494.

Motor 472, motor 474, motor 492, and motor 494 are electrically connected to, for example, controller 14. Controller 14 controls motor 472, motor 474, motor 492, and motor 494 independently. Therefore, movement system 41 can move multiple power transmission coils 10 independently by controller 14 independently controlling motor 472, motor 474, motor 492, and motor 494. Note that the movement system 41 is not limited to the above example as long as it is capable of moving multiple power transmission coils 10 independently.

The position detection device 42 shown in FIG. 5 is, for example, a device for detecting the position of the power receiving coil 20 of the power receiving terminal 2. The position detection device 42 includes, for example, a plurality of first search coils 43 (six in the example of FIG. 5), a plurality of second search coils 44 (four in the example of FIG. 5), and a base 30. The base 30 is, for example, a printed wiring board. The base 30 is plate-shaped (for example, rectangular plate-shaped), and the plurality of first search coils 43 and the plurality of second search coils 44 are arranged on the base 30. The position detection device 42 is attached to the housing 48 so as to close the opening of the housing 48.

Each first search coil 43 is, for example, a rectangular coil. The multiple first search coils 43 are arranged on a first surface (e.g., the front surface) of the base 30. The multiple first search coils 43 are also arranged, for example, at equal intervals in the X-axis direction of the housing 48 and along the Y-axis direction of the housing 48.

Each second search coil 44 is, for example, a rectangular coil. The multiple second search coils 44 are arranged on the second surface (e.g., the back surface) of the base 30. The multiple second search coils 44 are also arranged, for example, at equal intervals in the Y-axis direction of the housing 48 and along the X-axis direction of the housing 48. In other words, the multiple second search coils 44 are arranged perpendicular to the multiple first search coils 43. The multiple first search coils 43 and the multiple second search coils 44 are electrically connected to the controller 14. Note that position information for the multiple first search coils 43 and the multiple second search coils 44 is pre-stored in the memory of the controller 14.

The controller 14 periodically transmits, for example, a pulse signal to the multiple first search coils 43 and the multiple second search coils 44. Furthermore, for example, when the power receiving terminal 2 is placed on the power transmitter 1, the controller 14 receives an echo signal excited by the pulse signal and output from the power receiving coil 20 of the power receiving terminal 2 from the search coils (first search coil 43 and second search coil 44) positioned opposite the power receiving coil 20 of the power receiving terminal 2. This allows the controller 14 to detect the power receiving coil 20 of the power receiving terminal 2 via the position detection device 42. Furthermore, because the controller 14 can detect the power receiving coil 20 of the power receiving terminal 2, it can also detect the number of power receiving coils 20.

Furthermore, when the controller 14 receives an echo signal, it calculates the position of the receiving coil 20 based on the position information (X and Y coordinates of the position detection device 42) of the search coil that received the echo signal and the signal level of the echo signal. This allows the controller 14 to detect the position of the receiving coil 20 via the position detection device 42. Therefore, the controller 14 can move the transmitting coil 10 to the position of the receiving coil 20 by independently controlling the motors 472, 474, 492, and 494 of the movement system 41 based on the position information of the receiving coil 20.

(2.1.7) Sensor Sheet The sensor sheet 50 shown in FIG. 4 is, for example, a sensor sheet for detecting the position of the power receiving terminal 2. The sensor sheet 50 also outputs the detection result of the position of the power receiving terminal 2 to the controller 14. The sensor sheet 50 is, for example, a capacitive pressure-sensitive sensor sheet. The sensor sheet 50 includes, for example, a plurality of first electrodes 51 (ten in the example of FIG. 4 ), a plurality of second electrodes 52 (seven in the example of FIG. 4 ), and a base 53. The base 53 is, for example, a plate-shaped (e.g., rectangular) dielectric sheet, on which the plurality of first electrodes 51 and the plurality of second electrodes 52 are arranged. The plurality of first electrodes 51 and the plurality of second electrodes 52 are electrically connected to the controller 14.

The multiple first electrodes 51 are electrodes for detecting the position in the X-axis direction (X coordinate) of the power receiving terminal 2 arranged on the sensor sheet 50. Each first electrode 51 is, for example, rectangular. The multiple first electrodes 51 are arranged on a first surface (for example, the front surface) of the base 53. Furthermore, the multiple first electrodes 51 are, for example, arranged at equal intervals in the X-axis direction of the base 53 and are also arranged along the Y-axis direction of the base 53. Note that position information for the multiple first electrodes 51 is pre-stored in the memory of the controller 14.

The multiple second electrodes 52 are electrodes for detecting the position in the Y-axis direction (Y coordinate) of the power receiving terminal 2 arranged on the sensor sheet 50. Each second electrode 52 is, for example, rectangular. The multiple second electrodes 52 are arranged on the second surface (e.g., the back surface) of the base 53. The multiple second electrodes 52 are also arranged, for example, at equal intervals in the Y-axis direction of the base 53 and along the X-axis direction of the base 53. In other words, the multiple second electrodes 52 are arranged perpendicular to the multiple first electrodes 51. Position information for the multiple second electrodes 52 is pre-stored in the above-mentioned memory of the controller 14.

For example, when a power receiving terminal 2 is placed on the sensor sheet 50, the thickness of the base 53 at the position where the power receiving terminal 2 is placed decreases due to the weight of the power receiving terminal 2, and the capacitance between the first electrode 51 and second electrode 52 at the position where the power receiving terminal 2 is placed increases. This allows the controller 14 to detect the position of the power receiving terminal 2 via the sensor sheet 50. Furthermore, because the controller 14 can detect the position of the power receiving terminal 2, it can also detect the number of power receiving terminals 2.

(2.2) Power Receiving Terminal As shown in Fig. 1 , for example, the power receiving terminal 2 includes a plurality of (two in the example of Fig. 1 ) power receiving coils 20, a combiner 23a, and one power receiving circuit 21. The plurality of power receiving coils 20 include a first power receiving coil 20a and a second power receiving coil 20b. The power receiving terminal 2 is, for example, a mobile device (e.g., a smartphone, a tablet terminal, etc.). In short, the power receiving terminal 2 is a mobile device having a plurality of power receiving coils 20.

(2.2.1) Receiving Coil The first receiving coil 20a receives power (AC power) transmitted from the first transmitting coil 10a of the power transmitter 1. The first receiving coil 20a has, for example, a circular shape in a plan view. The first receiving coil 20a is, for example, a spiral coil. The first receiving coil 20a is electrically connected to the combining unit 23a. The second receiving coil 20b has the same shape and function as the first receiving coil 20a. A detailed description of the second receiving coil 20b will be omitted.

(2.2.2) Combining Unit The combining unit 23a generates combined power by combining the power received by each of the multiple power receiving coils 20 (first power receiving coil 20a and second power receiving coil 20b). More specifically, the combining unit 23a performs RF (radio frequency) combining on the power received by each of the multiple power receiving coils 20 (first AC power) to generate combined power (second AC power).

The combining unit 23a includes a pair of connection points 22a, 22b. Connection point 22a is electrically connected to connection point 22b via the first power receiving coil 20a. Furthermore, connection point 22a is electrically connected to connection point 22b via the second power receiving coil 20b. In other words, the first power receiving coil 20a and the second power receiving coil 20b are electrically connected (wired) at the pair of connection points 22a, 22b. Furthermore, the pair of connection points 22a, 22b are electrically connected to the power receiving circuit 21.

(2.2.3) Power Receiving Circuit The power receiving circuit 21 converts, for example, the power received by each of the multiple power receiving coils 20 into output power. More specifically, the power receiving circuit 21 converts the combined power (second AC power) combined by the combiner 23a into output power (DC power). The power receiving circuit 21 also supplies the output power to, for example, a battery (not shown) of the power receiving terminal 2. Note that the number of power receiving circuits 21 is one, but may be multiple.

The power receiving circuit 21 is, for example, a full-wave rectifier. As shown in FIG. 3, the power receiving circuit 21 includes four diodes D21 to D24 and a capacitor C22. The four diodes D21 to D24 form a diode bridge. The diode bridge is electrically connected to a pair of connection points 22a and 22b in the combiner 23a. Specifically, the anode of diode D21 and the cathode of diode D22 are electrically connected to connection point 22a, for example. The anode of diode D23 and the cathode of diode D24 are electrically connected to connection point 22b, for example.

Capacitor C22 is electrically connected to the diode bridge. Specifically, the high-potential terminal of capacitor C22 is electrically connected to the cathode of diode D21 and the cathode of diode D23. The low-potential terminal of capacitor C22 is electrically connected to the anode of diode D22 and the anode of diode D24. Capacitor C22 is also electrically connected to, for example, the battery of the power receiving terminal 2.

(3) Operation of Power Transmitter The controller 14 of the power transmitter 1 shown in Fig. 1 determines whether or not the power receiving terminal 2 is present based on the detection result from the sensor sheet 50 (see Fig. 4). For example, when the detection result from the sensor sheet 50 (e.g., the capacitance between the first electrode 51 and the second electrode 52 at the position where the power receiving terminal 2 is placed on the power transmitter 1) is equal to or greater than a threshold, the controller 14 determines that the power receiving terminal 2 is present on the power transmitter 1. On the other hand, when the detection result from the sensor sheet 50 is less than the threshold, the controller 14 determines that the power receiving terminal 2 is not present on the power transmitter 1. The threshold is pre-stored in the memory of the controller 14.

The controller 14 also determines the number of power receiving terminals 2 based on the number of detection results from the sensor sheet 50. For example, if there is one detection result from the sensor sheet 50, the controller 14 determines that there is one power receiving terminal 2. The controller 14 also determines the number of power receiving circuits 21 based on the number of power receiving terminals 2. For example, if there is one power receiving terminal 2, the controller 14 determines that there is one power receiving circuit 21.

The controller 14 also determines whether the receiving coil 20 is present or not, based on an echo signal from the position detection device 42 (see Figure 5). For example, if the controller 14 receives an echo signal from the position detection device 42, it determines that the receiving coil 20 is located on the power transmitter 1. On the other hand, if the controller 14 does not receive an echo signal from the position detection device 42, it determines that the receiving coil 20 is not located on the power transmitter 1.

The controller 14 also determines the number of receiving coils 20 based on the number of echo signals from the position detection device 42. For example, if the number of echo signals from the position detection device 42 is two, the controller 14 determines that the number of receiving coils 20 is two.

As described above, when the controller 14 receives an echo signal, it calculates the position of the receiving coil 20 based on the position information of the search coils (first search coil 43 and second search coil 44) that received the echo signal and the signal level of the echo signal. Therefore, by independently controlling the motors 472, 474, 492, and 494 of the movement system 41 based on the position information of the receiving coil 20, the controller 14 can move the first transmitting coil 10a and the second transmitting coil 10b to the positions of the first receiving coil 20a and the second receiving coil 20b, for example, as shown in FIG. 1.

The controller 14 operates in either a high-power transmission mode or a multiple simultaneous transmission mode. Specifically, in the high-power transmission mode, the controller 14 controls the switch 13 so that the switch 13 is in the first connection state (the connection state of the switch 13 in FIG. 1). In addition, in the multiple simultaneous transmission mode, the controller 14 controls the switch 13 so that the switch 13 is in the second connection state (the connection state of the switch 13 in FIG. 7).

Furthermore, the controller 14 operates in either a high-power transmission mode or a multiple simultaneous transmission mode based on the number of receiving coils 20 and the number of receiving circuits 21. In other words, the controller 14 controls the switch 13 based on the number of receiving coils 20 and the number of receiving circuits 21 in the receiving terminal 2.

For example, as shown in FIG. 1, when there are multiple receiving coils 20 (two in the example of FIG. 1) and one receiving circuit 21, the controller 14 controls the switch 13 so that the same number of transmitting coils 10 as the number of receiving coils 20 (two in the example of FIG. 1) are connected to one transmitting circuit 11 (first transmitting circuit 11a in the example of FIG. 1). In other words, when there are multiple receiving coils 20 and one receiving circuit 21, the controller 14 operates in high power transmission mode.

In the power transmitter 1, in the high-power transmission mode, for example, power from the first power transmission circuit 11a is supplied to each of the first power transmission coil 10a and the second power transmission coil 10b, so it is possible to make the frequency, phase, and power value of the power (AC power) transmitted from the first power transmission coil 10a the same as the frequency, phase, and power value of the power (AC power) transmitted from the second power transmission coil 10b. This makes it possible for the power transmitter 1 to improve the efficiency (power efficiency) of the power supplied contactlessly from the power transmitter 1 to the power receiving terminal 2.

Note that "making the frequency, phase, and power value of the power transmitted from the first power transmission coil 10a the same as the frequency, phase, and power value of the power transmitted from the second power transmission coil 10b" does not necessarily mean that the frequency, phase, and power value of the power transmitted from the first power transmission coil 10a and the frequency, phase, and power value of the power transmitted from the second power transmission coil 10b are completely the same. For example, it also includes cases where the difference (absolute value of the difference) between the frequency, phase, and power value of the power transmitted from the first power transmission coil 10a and the frequency, phase, and power value of the power transmitted from the second power transmission coil 10b is equal to or less than a predetermined value.

Here, when the controller 14 operates in the high-power transmission mode, for example, the first power transmission circuit 11a preferably supplies greater power to the same number (plurality) of power transmission coils 10 (first power transmission coil 10a and second power transmission coil 10b) as the number of power receiving coils 20 than the power supplied only to the first power transmission coil 10a. In other words, when one power transmission circuit 11 is connected to multiple power transmission coils 10, it preferably supplies greater power to the multiple power transmission coils 10 than the power (reference power) supplied to one power transmission coil 10 when one power transmission coil 10 is connected to one power transmission circuit 11. This reduces the reduction in power supplied contactlessly to the power receiving terminal 2 in the power transmitter 1 when operating in the high-power transmission mode, for example.

Furthermore, it is more preferable that the first power transmission circuit 11a supplies twice the power supplied to the first power transmission coil 10a alone to the first power transmission coil 10a and the second power transmission coil 10b. In other words, when one power transmission circuit 11 is connected to multiple power transmission coils 10, it is more preferable that it supplies a reference power proportional to the number of power transmission coils 10 (a reference power multiplied by the number of power transmission coils 10) to the multiple power transmission coils 10. This further reduces the reduction in the power supplied contactlessly to the power receiving terminal 2 when the power transmitter 1 operates, for example, in a high-power transmission mode.

Furthermore, as shown in FIG. 7, for example, when the number of receiving coils 20 and the number of receiving circuits 21 are the same (one each in the example of FIG. 7) and there are multiple receiving circuits 21 (two in the example of FIG. 7), the controller 14 controls the switch 13 so that multiple (two in the example of FIG. 7) transmitting coils 10 are connected one-to-one to multiple (two in the example of FIG. 7) transmitting circuits 11. In other words, when the number of receiving coils 20 and the number of receiving circuits 21 are the same and there are multiple receiving circuits 21, the controller 14 operates in multiple simultaneous power transmission mode.

Note that "when the number of receiving coils 20 and the number of receiving circuits 21 are the same and there are multiple receiving circuits 21" refers to a case where multiple (two in the example of FIG. 7) receiving terminals 2A and 2B are arranged on the power transmitter 1, as shown in FIG. 7. The receiving terminal 2A has one receiving coil 20 (third receiving coil 20c) and one receiving circuit 21. Unlike the receiving terminal 2, the third receiving coil 20c of the receiving terminal 2A is electrically connected to the receiving circuit 21 without going through the combining unit 23a of the receiving terminal 2 (see FIG. 1). The receiving terminal 2B has one receiving coil 20 (fourth receiving coil 20d) and one receiving circuit 21. Like the power receiving terminal 2A, the fourth power receiving coil 20d of the power receiving terminal 2B is electrically connected to the power receiving circuit 21 without going through the combiner 23a of the power receiving terminal 2. In short, the power receiving terminal 2A is a mobile device (e.g., a smartphone) that has one power receiving coil 20. The power receiving terminal 2B is a mobile device (e.g., a tablet terminal) that also has one power receiving coil 20.

The controller 14 also operates in the multiple simultaneous power transmission mode when, for example, only one power receiving terminal 2A of two power receiving terminals 2A, 2B is placed on the power transmitter 1. In other words, when there is one power receiving coil 20 and one power receiving circuit 21, the controller 14 controls the switch 13 so that one of the multiple power transmitting coils 10 is connected to one of the multiple power transmitting circuits 11. In this case, the controller 14 controls, for example, only the first power transmitting circuit 11a that supplies power to the first power transmitting coil 10a located opposite the third power receiving coil 20c of the power receiving terminal 2A.

The operation of the power transmitter 1 will be explained below with reference to Figure 8.

The controller 14 determines whether or not a receiving coil 20 is present (S1 in FIG. 8). If there is no receiving coil 20 (No in S1 in FIG. 8), the controller 14 again determines whether or not there is a receiving coil 20 (S1 in FIG. 8). On the other hand, if there is a receiving coil 20 (Yes in S1 in FIG. 8), the controller 14 determines whether or not there is one receiving coil 20 (S2 in FIG. 8).

If there is one receiving coil 20 (Yes in S2 in FIG. 8), the controller 14 switches the power transmission mode to multiple simultaneous power transmission mode (S3 in FIG. 8). The controller 14 also calculates the position of the receiving coil 20 (e.g., the third receiving coil 20c) (S4 in FIG. 8). Then, the controller 14 moves the first transmitting coil 10a to a position opposite the third receiving coil 20c, and starts transmitting power from the first transmitting coil 10a to the third receiving coil 20c (S5 in FIG. 8).

The controller 14 also determines whether or not there are other power receiving coils 20 (for example, the fourth power receiving coil 20d) (S6 in FIG. 8). If the fourth power receiving coil 20d is present (Yes in S6 in FIG. 8), the controller 14 calculates the position of the fourth power receiving coil 20d (S7 in FIG. 8). The controller 14 then moves the second power transmitting coil 10b to a position opposite the fourth power receiving coil 20d, and begins transmitting power from the second power transmitting coil 10b to the fourth power receiving coil 20d (S8 in FIG. 8). When power transmission to all power receiving coils 20 (the third power receiving coil 20c and the fourth power receiving coil 20d) is completed (S9 in FIG. 8), the controller 14 ends control of the switch 13, first power transmitting circuit 11a, and second power transmitting circuit 11b.

On the other hand, if the fourth power receiving coil 20d is not present (No in S6 in FIG. 8), the controller 14 terminates control of the switch 13 and the first power transmitting circuit 11a when power transmission from all power receiving coils 20 (third power receiving coil 20c) is completed (S9 in FIG. 8).

If there are multiple power receiving coils 20 (e.g., two) (No in S2 in FIG. 8), the controller 14 determines whether there is one power receiving circuit 21 (S10 in FIG. 8). If there are multiple power receiving circuits 21 (No in S10 in FIG. 8), the controller 14 switches the power transmission mode to multiple simultaneous power transmission mode (S3 in FIG. 8) and performs the operation in multiple simultaneous power transmission mode as described above.

On the other hand, if there is only one power receiving circuit 21 (Yes in S10 in FIG. 8), the controller 14 calculates the positions of the multiple power receiving coils 20 (first power receiving coil 20a and second power receiving coil 20b) (S11 in FIG. 8). The controller 14 also switches the power transmission mode to the high-power transmission mode (S12 in FIG. 8). The controller 14 then moves, for example, the first power transmitting coil 10a to a position opposite the first power receiving coil 20a (S13 in FIG. 8). The controller 14 also moves, for example, the second power transmitting coil 10b to a position opposite the second power receiving coil 20b (S14 in FIG. 8).

After moving the first power transmitting coil 10a and the second power transmitting coil 10b, the controller 14 starts transmitting power from the first power transmitting coil 10a and the second power transmitting coil 10b to the first power receiving coil 20a and the second power receiving coil 20b, respectively (S15 in FIG. 8). When power transmission to all power receiving coils 20 (first power receiving coil 20a and second power receiving coil 20b) is completed (S9 in FIG. 8), the controller 14 ends control of the switch 13, the first power transmitting circuit 11a, and the second power transmitting circuit 11b.

(4) Effects The power transmitter 1 includes a plurality of power transmitting coils 10, a plurality of power transmitting circuits 11, a switch 13, and a controller 14. The controller 14 controls the switch 13 so that the switch 13 is in the first connection state (the connection state of the switch 13 in FIG. 1 ) or the second connection state (the connection state of the switch 13 in FIG. 7 ). This allows the power transmitter 1 to supply power to the power receiving terminal 2 in a contactless manner in either one of the high-power transmission mode and the multiple simultaneous transmission mode, for example, thereby making it possible to meet a variety of user needs.

As shown in FIG. 1, the power receiving terminal 2 includes multiple receiving coils 20 and one receiving circuit 21. As shown in FIG. 7, the power receiving terminal 2A and the power receiving terminal 2B include one receiving coil 20 and one receiving circuit 21. In short, the power receiving terminal 2, the power receiving terminal 2A, and the power receiving terminal 2B include at least one receiving coil 20 and at least one receiving circuit 21. Furthermore, the power receiving terminal 2, the power receiving terminal 2A, and the power receiving terminal 2B receive power transmitted from at least one or more of the multiple transmitting coils 10 of the power transmitter 1. This allows the power receiving terminal 2, the power receiving terminal 2A, and the power receiving terminal 2B to appropriately change the number of receiving coils 20 and receiving circuits 21 they include, and to receive power transmitted from at least one or more of the multiple transmitting coils 10 of the power transmitter 1. Therefore, power receiving terminal 2, power receiving terminal 2A, and power receiving terminal 2B can meet a variety of user needs.

The power receiving terminal 2 includes multiple power receiving coils 20 and one power receiving circuit 21. The power receiving terminal 2 also includes a combiner 23a. The power receiving circuit 21 converts the combined power generated by the combiner 23a into output power. This allows the power receiving terminal 2 to have fewer power receiving circuits 21 than, for example, a power receiving terminal that does not include a combiner 23a and includes multiple power receiving circuits 21 corresponding to each of the multiple power receiving coils 20, i.e., multiple power receiving circuits 21, thereby enabling miniaturization.

As shown in FIG. 1, the wireless power supply system 3 includes a power transmitter 1 and a power receiving terminal 2. As shown in FIG. 7, the wireless power supply system 3 also includes a power transmitter 1 and multiple power receiving terminals 2A and 2B. The controller 14 of the power transmitter 1 controls the switch 13 based on the number of power receiving coils 20 and the number of power receiving circuits 21. This allows the wireless power supply system 3 to meet a variety of user needs. Furthermore, in the wireless power supply system 3, a single power transmitter 1 can be used with a variety of power receiving terminals 2, 2A, and 2B, making it possible to meet even further needs.

When there are multiple receiving coils 20 and only one receiving circuit 21, the controller 14 controls the switch 13 so that the same number of transmitting coils 10 as the number of receiving coils 20 are connected to one of the multiple transmitting circuits 11. That is, when there are multiple receiving coils 20 and only one receiving circuit 21, the controller 14 operates in high-power transmission mode. This makes it possible for the wireless power transfer system 3 to supply greater power wirelessly than when power is supplied from one transmitting coil 10 to one receiving coil 20 wirelessly. In other words, the wireless power transfer system 3 can achieve high-power wireless power transfer. Furthermore, because the wireless power transfer system 3 is capable of supplying large amounts of power wirelessly as described above, it can also support rapid charging, for example.

Furthermore, in the power transmitter 1 of the wireless power supply system 3, in the high power transmission mode, for example, power is supplied from the first power transmission circuit 11a to each of the first power transmission coil 10a and the second power transmission coil 10b, so it is possible to make the frequency, phase, and power value of the power transmitted from the first power transmission coil 10a the same as the frequency, phase, and power value of the power transmitted from the second power transmission coil 10b. This makes it possible for the power transmitter 1 to improve the efficiency (power efficiency) of the power supplied contactlessly from the power transmitter 1 to the power receiving terminal 2.

When the number of receiving coils 20 and the number of receiving circuits 21 are the same and there is a plurality of receiving circuits 21, the controller 14 controls the switch 13 so that a plurality of transmitting coils 10 and a plurality of transmitting circuits 11 are connected one-to-one. In other words, when the number of receiving coils 20 and the number of receiving circuits 21 are the same and there is a plurality of receiving circuits 21, the controller 14 operates in multiple simultaneous power transmission mode. This makes it possible for the wireless power supply system 3 to simultaneously supply power to a plurality of power receiving terminals 2A, 2B in a contactless manner, as shown in FIG. 7, for example.

When there is one receiving coil 20 and one receiving circuit 21, the controller 14 controls the switch 13 so that one of the multiple transmitting coils 10 is connected to one of the multiple transmitting circuits 11. As a result, in the wireless power supply system 3, even if, for example, only one receiving terminal 2A is placed on the power transmitter 1, it is possible to supply power to the receiving terminal 2A contactlessly.

The control method for the switch 13 includes a first control process, a second control process, and a third control process. In the first control process, when the power receiving terminal 2 has a plurality of power receiving coils 20 and a single power receiving circuit 21, the switch 13 is controlled so that the same number of power transmitting coils 10 as the number of power receiving coils 20 among the plurality of power transmitting coils 10 are connected to one power transmitting circuit 11 among the plurality of power transmitting circuits 11. In the second control process, when the number of power receiving coils 20 and the number of power receiving circuits 21 are the same and there are a plurality of power receiving circuits 21, the switch 13 is controlled so that the plurality of power transmitting coils 10 and the plurality of power transmitting circuits 11 are connected one-to-one. In the third control process, when there is one power receiving coil 20 and one power receiving circuit 21, the switch 13 is controlled so that one of the multiple power transmitting coils 10 is connected to one of the multiple power transmitting circuits 11. In other words, the above control method is a control method for the switch 13 that realizes the above wireless power feeding system 3. Therefore, similar to the above wireless power feeding system 3, the above control method can meet a variety of user needs.

The above control method is realized by one or more processors executing a program (computer program). This program is, for example, a program that causes one or more processors of the controller 14 to execute the above control method. Therefore, like the above control method, the above program can meet a variety of user needs.

(5) Modifications The first power transmission coil 10a and the second power transmission coil 10b of the power transmitter 1 are circular in plan view. However, for example, they may be elliptical in plan view or rectangular in plan view.

The first power supply circuit 12a is provided outside the first power transmission circuit 11a, but may be provided inside the first power transmission circuit 11a. The second power supply circuit 12b is provided outside the second power transmission circuit 11b, but may be provided inside the second power transmission circuit 11b. The first power supply circuit 12a and the second power supply circuit 12b are configured separately, but may also be configured integrally.

The external power source is not limited to a commercial power source, and may be, for example, a battery. In this case, the first power supply circuit 12a and the second power supply circuit 12b are, for example, DC/DC converters.

The sensor sheet 50 is not limited to a capacitance-type pressure-sensitive sensor sheet, and may be, for example, a resistive film-type pressure-sensitive sensor sheet. In this case, the base 53 of the sensor sheet 50 is an air layer.

The movement system 41 of the main body 40 is not limited to a mechanism for moving multiple power transmission coils 10 (a moving coil mechanism), but may also be a so-called multi-coil mechanism in which multiple (nine in the example of FIG. 9) power transmission coils 10 are arranged within a housing 48, as shown in FIG. 9, for example. In this case, the power transmitter 1 includes multiple power transmission coils 10, multiple (two in the example of FIG. 10), multiple power transmission circuits 11, multiple (two in the example of FIG. 10) power supply circuits 12, multiple (two in the example of FIG. 10), and a controller 14, as shown in FIG. 10. Each switch 17 is a single-pole, multiple-throw switch. The controller 14 controls the multiple switches 17 to switch the connections between the multiple power transmission coils 10 and the multiple power transmission circuits 11, in the same way as when controlling switch 13 (see FIG. 1).

The power transmitter 1 can also be configured without the switch 13. In this case, for example, the first power transmission circuit 11a is connected to the first power transmission coil 10a, and the second power transmission circuit 11b is connected to the second power transmission coil 10b. In this case, the controller 14 controls the first power transmission circuit 11a and the second power transmission circuit 11b in the high-power transmission mode so that the frequency, phase, and power value of the power (AC power) transmitted from the first power transmission coil 10a are the same as the frequency, phase, and power value of the power (AC power) transmitted from the second power transmission coil 10b. This enables the power transmitter 1 to improve the efficiency (power efficiency) of the power supplied contactlessly from the power transmitter 1 to the power receiving terminal 2.

Note that "the frequency, phase, and power value of the power transmitted from the first power transmission coil 10a are the same as the frequency, phase, and power value of the power transmitted from the second power transmission coil 10b" does not necessarily mean that the frequency, phase, and power value of the power transmitted from the first power transmission coil 10a are exactly the same as the frequency, phase, and power value of the power transmitted from the second power transmission coil 10b. For example, it also includes the case where the difference (absolute value of the difference) between the frequency, phase, and power value of the power transmitted from the first power transmission coil 10a and the frequency, phase, and power value of the power transmitted from the second power transmission coil 10b is equal to or less than a predetermined value.

The power receiving circuit 21 of the power receiving terminal 2 is not limited to a full-wave rectifier, and may be, for example, a half-wave rectifier having a diode D25 and a capacitor C23, as shown in FIG. 11. In this case, the anode of diode D25 is electrically connected to connection point 22a of the combiner 23a (see FIG. 1). The cathode of diode D25 is electrically connected to connection point 22b of the combiner 23a via capacitor C23. Capacitor C23 is electrically connected, for example, to the battery of the power receiving terminal 2. This allows the power receiving circuit 21 of the power receiving terminal 2 to be more compact than if it were a full-wave rectifier. Therefore, the power receiving terminal 2 can also be made smaller.

Furthermore, the power receiving circuit 21 is not limited to a full-wave rectifier, and may be, for example, a synchronous rectifier having four switching elements Q21 to Q24 and a capacitor C21, as shown in FIG. 12. In this case, each of the four switching elements Q21 to Q24 is, for example, a MOSFET, and the power receiving terminal 2 further includes a controller (not shown) that controls the four switching elements Q21 to Q24.

Switching element Q21 and switching element Q22 are connected in series, and connection point 24a of switching element Q21 and switching element Q22, which are connected in series, is electrically connected to connection point 22a of combining section 23a (see Figure 1). Switching element Q23 and switching element Q24 are connected in series, and the series-connected switching elements Q23 and Q24 are connected in parallel to the series-connected switching elements Q21 and Q22. Furthermore, connection point 24b of switching element Q23 and switching element Q24, which are connected in series, is electrically connected to connection point 22b of combining section 23a. Capacitor C21 is connected in parallel to the series-connected switching elements Q23 and Q24. Capacitor C21 is electrically connected, for example, to the battery of power receiving terminal 2. This allows power receiving circuit 21 of power receiving terminal 2 to achieve improved power efficiency compared to a full-wave rectifier.

The power receiving terminal 2 may further include multiple phase circuits 25 (two in the example of FIG. 13), as shown in FIG. 13, for example. The multiple phase circuits 25 include a first phase circuit 25a and a second phase circuit 25b. The first phase circuit 25a is electrically connected to the first power receiving coil 20a. The first phase circuit 25a is also electrically connected to a pair of connection points 22a, 22b of the combiner 23a. The second phase circuit 25b is electrically connected to the second power receiving coil 20b. The second phase circuit 25b is also electrically connected to a pair of connection points 22a, 22b of the combiner 23a.

The first phase circuit 25a adjusts the phase of the power (the first AC power) received by the first receiving coil 20a. As shown in FIG. 14, the first phase circuit 25a includes a detection circuit 26, a phase shifter 27, and a controller 28. The controller 28 includes a memory (not shown), similar to the controller 14 of the power transmitter 1, for example.

The detection circuit 26 shown in FIG. 14 detects, for example, the phase of the power received by the first power receiving coil 20a (see FIG. 13) and transmits a detection signal K1 containing information about this phase to the controller 28. The detection circuit 26 is electrically connected to the first power receiving coil 20a. The detection circuit 26 is also electrically connected to the controller 28.

The controller 28, for example, receives the detection signal K1 from the detection circuit 26 and compares the phase of the information contained in the detection signal K1 with a reference phase pre-stored in the memory. The controller 28 also, for example, calculates the phase difference between the phase contained in the detection signal K1 and the reference phase, and transmits a control signal K2 containing information about this phase difference to the phase shifter 27.

The phase shifter 27 receives, for example, a control signal K2 from the controller 28, and adjusts the phase of the power received by the first power receiving coil 20a according to the phase difference of the information contained in the control signal K2. The phase shifter 27 is electrically connected to the controller 28. The phase shifter 27 is also electrically connected to the first power receiving coil 20a via the detection circuit 26.

The second phase circuit 25b shown in Figure 13 adjusts the phase of the power received by the second receiving coil 20b. The second phase circuit 25b has the same configuration and mechanism as the first phase circuit 25a. However, the second phase circuit 25b differs from the first phase circuit 25a in that the detection circuit 26 (see Figure 14) is electrically connected to the second receiving coil 20b.

By further including multiple phase circuits 25, the power receiving terminal 2 can, for example, make the phase of the power received by the first power receiving coil 20a and the phase of the power received by the second power receiving coil 20b the same. This allows the power receiving terminal 2 to prevent a decrease in the power combined by the combining unit 23a compared to when, for example, the phases of the power received by the first power receiving coil 20a and the power received by the second power receiving coil 20b are different.

The power receiving terminal 2 includes multiple phase circuits 25 (first phase circuit 25a and second phase circuit 25b), but may include only one phase circuit 25 (e.g., first phase circuit 25a). That is, the power receiving terminal 2 is required to include at least one phase circuit 25. In this case, the first phase circuit 25a is configured, for example, to detect the phase of the power received by the second power receiving coil 20b. The first phase circuit 25a also adjusts the phase of the power received by the first power receiving coil 20a so that the phase of the power received by the first power receiving coil 20a matches the phase of the power received by the second power receiving coil 20b. Here, the controller 28 shown in FIG. 14 is provided inside the phase circuit 25, but may also be provided outside the phase circuit 25. The controller 28 may be, for example, a controller (not shown) that is pre-installed in the power receiving terminal 2.

As shown in FIG. 1, the power receiving terminal 2 is configured to include multiple (two in the example of FIG. 1) power receiving coils 20, a combining unit 23a, and one power receiving circuit 21, but is not limited to this configuration. For example, as shown in FIG. 15, the power receiving terminal 2C may be configured to include multiple (two in the example of FIG. 15) power receiving coils 20, multiple (two in the example of FIG. 15) power receiving circuits 21, and a combining unit 23b. The combining unit 23b includes a pair of connection points 22c, 22d.

In this case, the first power receiving coil 20a is electrically connected to the first power receiving circuit 21a, for example, in the same manner as the third power receiving coil 20c (see FIG. 7) of the power receiving terminal 2A. The second power receiving coil 20b is electrically connected to the second power receiving circuit 21b, for example, in the same manner as the fourth power receiving coil 20d (see FIG. 7) of the power receiving terminal 2B. The first power receiving circuit 21a is electrically connected to a pair of connection points 22c, 22d of the combining unit 23b. The second power receiving circuit 21b is electrically connected to a pair of connection points 22c, 22d of the combining unit 23b. In other words, the first power receiving circuit 21a and the second power receiving circuit 21b are electrically connected (wired) at the pair of connection points 22c, 22d. The pair of connection points 22c, 22d are also electrically connected to the battery (not shown) of the power receiving terminal 2C.

The first power receiving circuit 21a converts the power received by the first power receiving coil 20a into output power (first output power). The second power receiving circuit 21b converts the power received by the second power receiving coil 20b into output power (second output power). The combiner 23b combines the first output power converted by the first power receiving circuit 21a and the second output power converted by the second power receiving circuit 21b to generate combined power. The combiner 23b also supplies the combined power to the battery, for example.

Unlike the power receiving terminal 2 (see Figure 1) which has one power receiving circuit 21, the power receiving terminal 2C has multiple power receiving circuits 21 (two in the example of Figure 15), and the multiple power receiving circuits 21 convert the power received by the multiple power receiving coils 20 into output power, and then generate a composite power. Therefore, the power receiving terminal 2C can achieve better power efficiency than the power receiving terminal 2.

The power receiving terminal 2, the power receiving terminal 2A, the power receiving terminal 2B, and the power receiving terminal 2C are not limited to mobile devices, and may be, for example, wireless earphones. In other words, the power receiving terminal 2, the power receiving terminal 2A, the power receiving terminal 2B, and the power receiving terminal 2C may be electronic devices that include at least a battery. Furthermore, the power receiving terminal 2, the power receiving terminal 2A, the power receiving terminal 2B, and the power receiving terminal 2C are not limited to electronic devices that include a battery, and may be electronic devices such as displays (e.g., PC monitors).

The above-described embodiment 1 and modifications are only a part of the various embodiments and modifications of this disclosure.

(Embodiment 2)
16, the wireless power feeding system 3A according to the second embodiment differs from the wireless power feeding system 3 according to the first embodiment in that the power transmitter 1A further includes a communication circuit 19, and the power receiving terminal 2D further includes a communication circuit 29. Note that, in the wireless power feeding system 3A according to the second embodiment, the same components as those in the wireless power feeding system 3 according to the first embodiment (see FIGS. 1 to 7) are denoted by the same reference numerals, and descriptions thereof will be omitted.

The wireless power supply system 3A according to the second embodiment will be described below with reference to Figures 16 to 18.

(1) Wireless Power Supply System A wireless power supply system 3A includes a power transmitter 1A and a power receiving terminal 2D, as shown in Fig. 16. The wireless power supply system 3A supplies power from the power transmitter 1A to the power receiving terminal 2D in a contactless manner.

(2) Components of the Wireless Power Supply System (2.1) Power Transmitter As shown in Fig. 16 , the power transmitter 1A includes a plurality of (two in the example of Fig. 16 ) power transmission coils 10, a plurality of (two in the example of Fig. 16 ) power transmission circuits 11, a plurality of (two in the example of Fig. 16 ) power supply circuits 12, a switch 13, a controller 14, a communication circuit 19, and a main body 40 (see Fig. 5 ). Note that the power transmitter 1A does not include the sensor sheet 50 (see Fig. 4 ) of the power transmitter 1 of the first embodiment.

The communication circuit 19 communicates wirelessly with the communication circuit 29 (described below) of the power receiving terminal 2D. The communication circuit 19 also receives a communication signal K3 (described below) from the communication circuit 29. The communication circuit 19 is electrically connected to the controller 14.

(2.2) Power Receiving Terminal As shown in Fig. 16 , for example, the power receiving terminal 2D includes a plurality of (two in the example of Fig. 16 ) power receiving coils 20, a combiner 23a, one power receiving circuit 21, and a communication circuit 29. The power receiving terminal 2D is, for example, a mobile device having a plurality of power receiving coils 20, similar to the power receiving terminal 2 of the first embodiment.

The communication circuit 29 communicates wirelessly with the communication circuit 19 of the power transmitter 1A. The communication circuit 29 is electrically connected to a controller (not shown) of the power receiving terminal 2D. The controller of the power receiving terminal 2D has a memory (not shown), similar to the controller 14 of the power transmitter 1A, and information about the power receiving terminal 2D is pre-stored in the memory.

Furthermore, the communication circuit 29 transmits a communication signal K3 to the communication circuit 19 of the power transmitter 1A. The communication signal K3 is a signal that includes, for example, information on the number of power receiving terminals 2D, information on the number of power receiving coils 20, and information on the number of power receiving circuits 21. In other words, the communication circuit 29 of the power receiving terminal 2D transmits information on the number of power receiving terminals 2D, and information on the number of power receiving coils 20 and power receiving circuits 21 of the power receiving terminal 2D to the communication circuit 19 of the power transmitter 1A.

(3) Operation of Power Transmitter The controller 14 of the power transmitter 1A shown in Fig. 16 determines the presence or absence of the power receiving coil 20 in accordance with an echo signal from the position detection device 42 (see Fig. 5), similarly to the controller 14 of the power transmitter 1 of embodiment 1. When the power receiving coil 20 is present on the power transmitter 1A, the controller 14 controls the communication circuit 19 to start communication (e.g., handshake communication) between the communication circuit 19 and the communication circuit 29 of the power receiving terminal 2D.

The controller 14 then operates in either the high-power transmission mode or the multiple simultaneous transmission mode based on the information contained in the communication signal K3 received by the communication circuit 19. In other words, the controller 14 controls the switch 13 based on, for example, information on the number of power receiving terminals 2D and information on the number of power receiving coils 20 and power receiving circuits 21 of the power receiving terminals 2D. In other words, the controller 14 of the power transmitter 1A obtains information on the number of power receiving terminals 2D and information on the number of power receiving coils 20 and power receiving circuits 21 via the communication signal K3 from the communication circuit 29 of the power receiving terminal 2D without using the sensor sheet 50 of the power transmitter 1 of embodiment 1.

Furthermore, as shown in FIG. 17, for example, when multiple (two in the example of FIG. 17) power receiving terminals 2E, 2F are present on the power transmitter 1A, the controller 14 of the power transmitter 1A receives multiple (two in the example of FIG. 17) echo signals from multiple (two in the example of FIG. 17) power receiving coils 20. The power receiving terminal 2E, like the power receiving terminal 2A of embodiment 1 (see FIG. 7), has one power receiving coil 20 (third power receiving coil 20c) and one power receiving circuit 21. In short, the power receiving terminal 2E is, for example, a mobile device (e.g., a smartphone) that has one power receiving coil 20, like the power receiving terminal 2A of embodiment 1. The power receiving terminal 2E also has a communication circuit 29.

The power receiving terminal 2F, like the power receiving terminal 2B of embodiment 1 (see FIG. 7), includes one power receiving coil 20 (fourth power receiving coil 20d) and one power receiving circuit 21. In short, like the power receiving terminal 2B of embodiment 1, the power receiving terminal 2F is, for example, a mobile device (e.g., a tablet terminal) that includes one power receiving coil 20. The power receiving terminal 2F also includes a communication circuit 29.

When the controller 14 of the power transmitter 1A shown in FIG. 17 receives multiple echo signals, it controls the communication circuit 19 to initiate communication (e.g., handshake communication) between the communication circuit 19 and the communication circuit 29 of the power receiving terminal 2E, and also initiates communication between the communication circuit 19 and the communication circuit 29 of the power receiving terminal 2F. Then, based on the information contained in the multiple (two in the example of FIG. 17) communication signals K3 received by the communication circuit 19, the controller 14 operates in either the high-power transmission mode or the multiple simultaneous transmission mode.

In the multiple simultaneous power transmission mode, the controller 14 controls the first power transmission circuit 11a so that the frequency of the power (AC power) transmitted from the first power transmission coil 10a is a frequency (optimal frequency) that increases the efficiency of the power received by the third power receiving coil 20c of the power receiving terminal 2E, and is the power required by the power receiving terminal 2E. In the multiple simultaneous power transmission mode, the controller 14 controls the second power transmission circuit 11b so that the frequency of the power (AC power) transmitted from the second power transmission coil 10b is a frequency (optimal frequency) that increases the efficiency of the power received by the fourth power receiving coil 20d of the power receiving terminal 2F, and is the power required by the power receiving terminal 2F.

This allows the power transmitter 1A to transmit power to the power receiving terminal 2E and the power receiving terminal 2F with high power efficiency. In other words, the power transmitter 1A can keep the transmitted power low. The power transmitter 1A can also supply power to multiple power receiving terminals 2E and 2F so that the transmission time of the power supplied contactlessly to the power receiving terminal 2E is different from the transmission time of the power supplied contactlessly to the power receiving terminal 2F. Note that, in order to optimize the frequency of the power transmitted from the power transmitting coil 10, the controller 14, for example, transmits power from the power transmitting coil 10 that includes frequencies within a predetermined range, and sets the frequency at which the transmitted power is greatest as the optimal frequency. The controller 14 obtains the power required by the power receiving terminal 2E or the power receiving terminal 2F, for example, from the communication circuit 29.

The controller 14 also operates in the multiple simultaneous power transmission mode when, for example, only one power receiving terminal 2E of the two power receiving terminals 2E, 2F is placed on the power transmitter 1A. In this case, the controller 14 controls, for example, only the first power transmission circuit 11a that supplies power to the first power transmission coil 10a located opposite the third power receiving coil 20c of the power receiving terminal 2E.

The operation of power transmitter 1A will be explained below with reference to Figure 18.

The controller 14 determines whether or not a receiving coil 20 is present (S21 in FIG. 18). If there is no receiving coil 20 (No in S21 in FIG. 18), the controller 14 again determines whether or not there is a receiving coil 20 (S21 in FIG. 18). On the other hand, if there is a receiving coil 20 (Yes in S21 in FIG. 18), the controller 14 receives the communication signal K3 via the communication circuit 19 and then determines whether or not there is one receiving coil 20 (S22 in FIG. 18).

If there is one power receiving coil 20 (Yes in S22 in FIG. 18), the controller 14 switches the power transmission mode to multiple simultaneous power transmission mode (S23 in FIG. 18). The controller 14 also calculates the position of the power receiving coil 20 (e.g., the third power receiving coil 20c) (S24 in FIG. 18). The controller 14 then moves, for example, the first power transmitting coil 10a to a position opposite the third power receiving coil 20c, and starts transmitting power from the first power transmitting coil 10a to the third power receiving coil 20c (S25 in FIG. 18).

The controller 14 also determines whether or not there are other power receiving coils 20 (for example, the fourth power receiving coil 20d) (S26 in FIG. 18). If the fourth power receiving coil 20d is present (Yes in S26 in FIG. 18), the controller 14 calculates the position of the fourth power receiving coil 20d (S27 in FIG. 18). The controller 14 then moves the second power transmitting coil 10b to a position opposite the fourth power receiving coil 20d, and begins transmitting power from the second power transmitting coil 10b to the fourth power receiving coil 20d (S28 in FIG. 18). When power transmission to all power receiving coils 20 (the third power receiving coil 20c and the fourth power receiving coil 20d) is completed (S29 in FIG. 18), the controller 14 ends control of the switch 13, first power transmitting circuit 11a, and second power transmitting circuit 11b.

On the other hand, if the fourth power receiving coil 20d is not present (No in S26 in FIG. 18), the controller 14 terminates control of the switch 13 and the first power transmitting circuit 11a when power transmission to all power receiving coils 20 (third power receiving coil 20c) is completed (S29 in FIG. 18).

If there are multiple power receiving coils 20 (e.g., two) (No in S22 in FIG. 18), the controller 14 determines, for example, the number of power receiving terminals (power receiving terminals 2E and 2F in the example of FIG. 17) (S30 in FIG. 18). If there are multiple power receiving terminals 2E and 2F (e.g., two) (No in S30 in FIG. 18), the controller 14 switches the power transmission mode to multiple simultaneous power transmission mode (S23 in FIG. 18) and performs the operation in multiple simultaneous power transmission mode as described above.

On the other hand, for example, if there is one power receiving terminal 2D (Yes in S30 in FIG. 18), the controller 14 calculates the positions of multiple power receiving coils 20 (first power receiving coil 20a and second power receiving coil 20b) (S31 in FIG. 18). The controller 14 also determines whether there is one power receiving circuit 21 (S32 in FIG. 18). If there is one power receiving circuit 21 (Yes in S32 in FIG. 18), the controller 14 switches the power transmission mode to high-power transmission mode (S33 in FIG. 18). If there are multiple power receiving circuits 21 (e.g., two) (No in S32 in FIG. 18), the controller 14 switches the power transmission mode to multiple simultaneous power transmission mode (S34 in FIG. 18). Then, the controller 14 moves, for example, the first power transmitting coil 10a to a position facing the first power receiving coil 20a or the third power receiving coil 20c (S35 in FIG. 18). Also, the controller 14 moves, for example, the second power transmitting coil 10b to a position facing the second power receiving coil 20b or the fourth power receiving coil 20d (S36 in FIG. 18).

After moving the first power transmitting coil 10a and the second power transmitting coil 10b, the controller 14 starts transmitting power from the first power transmitting coil 10a and the second power transmitting coil 10b to the first power receiving coil 20a and the second power receiving coil 20b (or the third power receiving coil 20c and the fourth power receiving coil 20d), respectively (S37 in FIG. 18). When power transmission to all power receiving coils 20 is completed (S29 in FIG. 18), the controller 14 ends control of the switch 13, the first power transmitting circuit 11a, and the second power transmitting circuit 11b.

16 , for example, the wireless power feeding system 3A includes a power transmitter 1A further including a communication circuit 19, and a power receiving terminal 2D further including a communication circuit 29. This allows the controller 14 of the power transmitter 1A to acquire information on the number of power receiving terminals 2D, the number of power receiving coils 20, and the number of power receiving circuits 21 from the communication circuit 29 of the power receiving terminal 2D without using the sensor sheet 50 of the power transmitter 1 of the first embodiment.

As a result, the wireless power feeding system 3A does not require, for example, the sensor sheet 50 of the wireless power feeding system 3 of embodiment 1, making it possible to reduce the size of the power transmitter 1A compared to the wireless power feeding system 3 of embodiment 1. Furthermore, since the wireless power feeding system 3A does not require the sensor sheet 50, it is possible to reduce power consumption compared to the wireless power feeding system 3 of embodiment 1. Furthermore, since the wireless power feeding system 3A does not require the sensor sheet 50, it is possible to shorten, for example, the time from when the power receiving terminal 2D is placed on the power transmitter 1A to when power transmission to the power receiving terminal 2D starts compared to the wireless power feeding system 3 of embodiment 1.

(5) Modification The communication signal K3 is a signal including information on the number of power receiving terminals 2D and information on the number of power receiving coils 20 and power receiving circuits 21 of the power receiving terminals 2D, but may be a signal that does not include information on the number of power receiving terminals 2D. In other words, the communication signal K3 may be a signal that includes information on the number of power receiving coils 20 and power receiving circuits 21 of the power receiving terminals 2D. In this case, the power transmitter 1A includes the sensor sheet 50 (see FIG. 4 ) of the power transmitter 1 of embodiment 1.

As a modification of the second embodiment, modifications similar to those of the wireless power supply system 3 according to the modification of the first embodiment are possible. Therefore, the wireless power supply system 3A according to the modification of the second embodiment also achieves the same effects as the wireless power supply system 3A according to the second embodiment.

The second embodiment and the modifications described above are only a part of the various embodiments and modifications of this disclosure.

The present disclosure is not limited to the above embodiments, and it is possible to apply at least some of the configurations of the embodiments and modified examples in appropriate combinations.

(Aspects)
The present specification discloses the following aspects.

The power transmitter (1, 1A) according to the first aspect includes a plurality of power transmission coils (10), a plurality of power transmission circuits (11), a switch (13), and a controller (14). Each of the plurality of power transmission coils (10) transmits power contactlessly. The plurality of power transmission circuits (11) supply power to the plurality of power transmission coils (10), respectively. The switch (13) switches the connection between the plurality of power transmission coils (10) and the plurality of power transmission circuits (11). The controller (14) controls the switch (13).

This approach makes it possible to meet a wide variety of needs.

The power receiving terminal (2, 2A-2F) according to the second aspect includes at least one power receiving coil (20) and at least one power receiving circuit (21). The at least one power receiving coil (20) receives power transmitted from at least one power transmitting coil (10) among the multiple power transmitting coils (10) of the power transmitter (1, 1A) according to the first aspect. The at least one power receiving circuit (21) converts the power received by the at least one power receiving coil (20) into output power.

This approach makes it possible to meet a wide variety of needs.

In the power receiving terminal (2, 2D) according to the third aspect, in the second aspect, at least one power receiving coil (20) is a plurality of power receiving coils (20), and the power receiving terminal (2, 2D) further includes a combiner (23a) that combines the power received by each of the plurality of power receiving coils (20) to generate combined power. At least one power receiving circuit (21) converts the combined power combined by the combiner (23a) into output power.

This aspect allows for miniaturization.

A wireless power supply system (3, 3A) according to the fourth aspect includes a power transmitter (1, 1A) according to the first aspect and a power receiving terminal (2, 2A-2F) according to the second or third aspect. A controller (14) controls a switch (13) based on the number of power receiving coils (20) and the number of power receiving circuits (21) of the power receiving terminal (2, 2A-2F).

This approach makes it possible to meet a wide variety of needs.

The wireless power supply system (3A) according to the fifth aspect is the fourth aspect, wherein the power receiving terminals (2D-2F) further include a first communication circuit (29) that transmits information regarding the number of power receiving coils (20) and the number of power receiving circuits (21) via wireless communication. The power transmitter (1A) further includes a second communication circuit (19) that receives the information via wireless communication.

This aspect makes it possible to reduce the size of the power transmitter (1A).

In the wireless power supply system (3, 3A) according to the sixth aspect, in the fourth or fifth aspect, when there are multiple receiving coils (20) and one receiving circuit (21), the controller (14) controls the switch (13) so that the same number of transmitting coils (10) as the number of receiving coils (20) among the multiple transmitting coils (10) are connected to one of the multiple transmitting circuits (11).

According to this embodiment, it is possible to supply greater power contactlessly than when power is supplied contactlessly from one power transmitting coil (10) to one power receiving coil (20), for example.

The wireless power supply system (3, 3A) according to the seventh aspect is the sixth aspect, in which, when the same number of power transmission coils (10) are connected to one power transmission circuit (11), one power transmission circuit (11) supplies greater power to the same number of power transmission coils (10) than the power supplied to one power transmission coil (10) when one power transmission coil (10) is connected to one power transmission circuit (11).

This embodiment reduces the reduction in the power supplied contactlessly from the power transmitter (1, 1A) to the power receiving terminal (2, 2D).

The wireless power supply system (3, 3A) according to the eighth aspect is the fourth or fifth aspect, in which the controller (14) controls the switch (13) so that multiple power transmission coils (10) and multiple power transmission circuits (11) are connected one-to-one when the number of power receiving coils (20) and the number of power receiving circuits (21) are the same and there are multiple power receiving circuits (21).

According to this aspect, it is possible, for example, to simultaneously supply power to multiple power receiving terminals (2A, 2B) in a contactless manner.

In the wireless power supply system (3, 3A) according to the ninth aspect, in the fourth or fifth aspect, when there is one receiving coil (20) and one receiving circuit (21), the controller (14) controls the switch (13) so that one of the multiple transmitting coils (10) is connected to one of the multiple transmitting circuits (11).

According to this aspect, even if, for example, only one power receiving terminal (2A) is placed on the power transmitter (1), it is possible to supply power to the power receiving terminal (2A) contactlessly.

The control method according to the tenth aspect is a control method for a switch (13) that switches the connection between multiple power transmission coils (10) and multiple power transmission circuits (11), and includes a first control process, a second control process, and a third control process. In the first control process, when the number of power receiving coils (20) in the power receiving terminals (2, 2A to 2F) is multiple and the number of power receiving circuits (21) in the power receiving terminals (2, 2A to 2F) is one, the switch (13) is controlled so that the same number of power transmission coils (10) as the number of power receiving coils (20) among the multiple power transmission coils (10) are connected to one power transmission circuit (11) among the multiple power transmission circuits (11). In the second control process, when the number of receiving coils (20) and the number of receiving circuits (21) are the same and there are multiple receiving circuits (21), the switch (13) is controlled so that multiple transmitting coils (10) and multiple transmitting circuits (11) are connected one-to-one. In the third control process, when there is one receiving coil (20) and one receiving circuit (21), the switch (13) is controlled so that one transmitting coil (10) of the multiple transmitting coils (10) is connected to one transmitting circuit (11) of the multiple transmitting circuits (11).

This approach makes it possible to meet a wide variety of needs.

REFERENCE SIGNS LIST 1 Power transmitter 1A Power transmitter 2 Power receiving terminals 2A to 2F Power receiving terminals 3 Wireless power feeding system 3A Wireless power feeding system 10 Power transmitting coil 11 Power transmitting circuit 13 Switch 14 Controller 19 Communication circuit (second communication circuit)
20: power receiving coil 21: power receiving circuit 23a: combining unit 29: communication circuit (first communication circuit)

Claims (10)

a plurality of power transmission coils for transmitting power in a contactless manner;
a plurality of power transmitting circuits that supply the power to the plurality of power transmitting coils, respectively;
a switch for switching connections between the plurality of power transmitting coils and the plurality of power transmitting circuits;
a controller for controlling the switch;
Power transmitter. at least one or more power receiving coils that receive the power transmitted from at least one or more power transmitting coils among the plurality of power transmitting coils of the power transmitter according to claim 1;
and at least one power receiving circuit that converts the power received by the at least one power receiving coil into output power.
Power receiving terminal. the at least one receiving coil is a plurality of receiving coils,
a combining unit that combines the electric power received by each of the plurality of power receiving coils to generate a combined electric power;
the at least one power receiving circuit converts the combined power combined by the combining unit into the output power.
The power receiving terminal according to claim 2 . The power transmitter according to claim 1;
The power receiving terminal according to claim 2 or 3,
the controller controls the switch based on the number of power receiving coils and the number of power receiving circuits of the power receiving terminal.
Wireless power supply system. the power receiving terminal further includes a first communication circuit that transmits information about the number of the power receiving coils and the number of the power receiving circuits by wireless communication;
the power transmitter further includes a second communication circuit that receives the information via the wireless communication.
The wireless power supply system according to claim 4 . When the number of the power receiving coils is plural and the number of the power receiving circuits is one, the controller controls the switch so that the same number of power transmitting coils as the number of the power receiving coils among the plurality of power transmitting coils are connected to one power transmitting circuit among the plurality of power transmitting circuits.
The wireless power supply system according to claim 4 . When the same number of power transmitting coils and the one power transmitting circuit are connected, the one power transmitting circuit supplies, to the same number of power transmitting coils, power that is greater than power that is supplied to the one power transmitting coil when the one power transmitting coil and the one power transmitting circuit are connected.
The wireless power supply system according to claim 6 . When the number of the power receiving coils and the number of the power receiving circuits are the same and there are a plurality of power receiving circuits, the controller controls the switch so that the plurality of power transmitting coils and the plurality of power transmitting circuits are connected one-to-one.
The wireless power supply system according to claim 4 . when the number of the power receiving coils is one and the number of the power receiving circuits is one, the controller controls the switch so that one power transmitting coil of the plurality of power transmitting coils is connected to one power transmitting circuit of the plurality of power transmitting circuits.
The wireless power supply system according to claim 4 . A method for controlling a switch that switches connections between a plurality of power transmitting coils and a plurality of power transmitting circuits, comprising:
a first control process for controlling the switch so that, when the power receiving terminal has a plurality of power receiving coils and a single power receiving circuit, the same number of power transmitting coils as the number of power receiving coils among the plurality of power transmitting coils are connected to one power transmitting circuit among the plurality of power transmitting circuits;
a second control process for controlling the switch when the number of the power receiving coils and the number of the power receiving circuits are the same and there are a plurality of power receiving circuits, so that the plurality of power transmitting coils and the plurality of power transmitting circuits are connected one-to-one;
and a third control process for controlling the switch so that one power transmitting coil of the plurality of power transmitting coils is connected to one power transmitting circuit of the plurality of power transmitting circuits when the number of the power receiving coils is one and the number of the power receiving circuits is one.
Control method.