Wireless power supply system

Abstract

To provide a system capable of placing a wireless power incoming device at an appropriate position while having a simple configuration.SOLUTION: A transmission side coil 8 is provided on a wireless power transmission device 6. LEDs 10a and 10B, which are position indicator lamps, are provided on a center line of the transmission side coil 8 and are always lit. The LEDs 10a and 10b are provided on both sides of the transmission side coil 8 at symmetrical positions with respect to the transmission side coil 8. LEDs 12a and 12b are provided as power-feeding indicator lamps outside the LEDs 10a and 10b. The LEDs 12a and 12b are extinguished in a normal state. When a user places a smartphone 20, which is a wireless power incoming device, on the transmission side coil 8, the wireless power transmission device 6 determines that power can be supplied and lights the LEDs 12a and 12b. Thereby, the user can confirm that the power is fed.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] This invention relates to a wireless power supply system.

Background Art

[0002] In smartphones, control devices, etc., wireless power supply is used. For example, power is supplied from a wireless power transmission device to a wireless power reception device by electromagnetic induction between a transmission-side coil provided in the wireless power transmission device and a reception-side coil provided in the wireless power reception device.

[0003] At this time, if the reception-side coil of the wireless power reception device and the transmission-side coil of the wireless power transmission device are not properly magnetically coupled by electromagnetic induction, the power supply power may become small or power supply may not be possible.

[0004] Therefore, for example, as in Patent Document 1, there is a configuration in which the transmission-side coil of the wireless power transmission device is configured to be movable and drive-controlled to be in an appropriate position with respect to the reception-side coil. According to this technology, even if the relative positional relationship between the reception-side coil and the transmission-side coil is displaced, the positional relationship between the two coils can be set to an appropriate position for power supply.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, in the conventional technology as described above, it is necessary to drive the transmission-side coil, which has a problem of complicating the structure of the device. In addition, there may be a driving sound, which is also a nuisance in use.

[0007] The object of the present invention is to solve the above problems and provide a system that, while having a simple configuration, can place a wireless power receiving device at an appropriate position.

Means for Solving the Problems

[0008] Some features that can be independently applied in the present invention are listed below.

[0009] (1) In a wireless power transmission device according to the present invention, a transmission-side coil for performing wireless power transmission with a reception-side coil of a wireless power receiving device, and a mounting surface provided on the transmission-side coil for mounting the wireless power receiving device, the mounting surface being a line passing near the center of the transmission-side coil and having position marks on both sides of the transmission-side coil for indicating positions where the wireless power receiving device can be mounted. In the wireless power transmission device further including a control unit that acquires information data from the wireless power receiving device via the transmission-side coil and controls power supply to the transmission-side coil, a power supply indicator light is provided on the mounting surface, and the control unit determines whether power can be supplied from the transmission-side coil to the reception-side coil based directly or indirectly on the information data from the wireless power receiving device. If it is determined that power cannot be supplied, the power supply indicator light is set to a first state, and if it is determined that power can be supplied, the power supply indicator light is set to a second state.

[0010] Therefore, the position marks serve as a guide for the position where the wireless power receiving device is to be mounted, and a reliable position can be known by the power supply indicator light.

[0011] (2) In a wireless power transmission device according to the present invention, the power supply indicator light is provided outside the position mark on a line passing near the center of the power transmission-side coil.

[0012] Therefore, it is possible to easily confirm that the device is in a power supply state.

[0013] (3) The wireless power transmission device according to the present invention is characterized in that the position mark is a light emitter that always lights up while power is being supplied to the wireless power supply device.

[0014] Therefore, visibility is good and alignment is easy when placing the wireless power receiving device.

[0015] (4) The wireless power transmission device according to the present invention is characterized in that a power supply indicator light is used as the position mark.

[0016] Therefore, the configuration can be simplified.

[0017] (5) The wireless power transmission device according to the present invention is characterized in that the power supply indicator light includes a linear light source arranged along a line passing near the center of the power transmission side coil.

[0018] Therefore, visibility is good and alignment is easy.

[0019] (6) The wireless power transmission device according to the present invention is characterized in that the first state of the power supply indicator light is off, and the second state of the power supply indicator light is on.

[0020] Therefore, the states can be distinguished by being off and on.

[0021] (7) The wireless power transmission device according to the present invention is characterized in that the first state of the power supply indicator light is lighting with a first color, and the second state of the power supply indicator light is lighting with a second color.

[0022] Therefore, the states can be distinguished by color.

[0023] (8) The wireless power transmission device according to the present invention includes a transmission-side coil for performing wireless power transmission with a reception-side coil of a smartphone, and a placement surface provided on the transmission-side coil for placing the smartphone. The placement surface is a line passing near the center of the transmission-side coil and on both sides of the transmission-side coil. To indicate the positions where the smartphone is placed, it has position indicator lights that are always on. In a wireless power transmission device further including a control unit that acquires information data from the smartphone via the transmission-side coil and controls the power supply to the transmission-side coil, a power supply indicator light is provided on the placement surface. At least a part of the power supply indicator light is arranged to be visible on both sides of the short width of the smartphone when the smartphone is placed at a position where power can be supplied from the transmission-side coil to the reception-side coil of the smartphone. The control unit determines whether power can be supplied from the transmission-side coil to the reception-side coil of the smartphone based directly or indirectly on the information data from the smartphone. If it determines that power cannot be supplied, it sets the power supply indicator light to a first state, and if it determines that power can be supplied, it sets the power supply indicator light to a second state.

[0024] Therefore, the position indicator lights serve as a guide for the positions where the smartphone is placed, and the reliable positions can be known by the power supply indicator lights.

[0025] (9) The wireless power supply system according to the present invention is a wireless power supply system including a wireless power transmission device and a wireless power reception device having a flat display. The wireless power transmission device includes a transmission-side coil for performing wireless power transmission with a reception-side coil of the wireless power reception device, and a placement surface provided on the transmission-side coil for placing the wireless power reception device. The placement surface has position marks for indicating positions where the wireless power reception device is to be placed on both sides of the transmission-side coil on a line passing through the vicinity of the center of the transmission-side coil. The wireless power transmission device also includes a control unit that acquires information data from the wireless power reception device via the transmission-side coil and controls power supply to the transmission-side coil. The wireless power reception device includes a recording unit that records the position of the reception-side coil of the wireless power reception device, and reception-side coil position display means that, when in a state capable of receiving power from the wireless power transmission device, performs a reception-side coil position display indicating the position of the reception-side coil at a position of the flat display corresponding to the recorded position of the reception-side coil.

[0026] Therefore, more appropriate alignment is enabled by the reception-side coil position display.

[0027] (10) The wireless power supply system according to the present invention is characterized in that the position marks include at least horizontally arranged position marks, and the reception-side coil position display includes a display corresponding to the longitudinal center line of the power reception coil and a display corresponding to the lateral center line of the power reception coil.

[0028] Therefore, alignment in the vertical and horizontal directions is easy.

[0029] (11) The wireless power receiving device according to the present invention is a wireless power receiving device capable of receiving power supply from a wireless power transmitting device, and includes a receiving coil for receiving power supply from a transmitting coil on the transmitting side of the wireless power transmitting device, a recording unit for recording the position of the receiving coil of the wireless power receiving device, and a power supply display control means for performing a receiving coil position display indicating the position of the receiving coil at a position of a flat panel display corresponding to the recorded position of the receiving coil when the wireless power receiving device is in a state capable of receiving power from the wireless power transmitting device.

[0030] Therefore, it is easy to align the wireless power receiving device.

[0031] (12) The wireless power transmitting device according to the present invention is characterized in that the wireless power receiving device is a smartphone or a tablet computer.

[0032] Therefore, it is easy to align a smartphone or a tablet computer.

[0033] (13) The wireless power transmitting device according to the present invention is characterized in that the wireless power transmitting device is a desk having a placement surface as a desk surface.

[0034] Therefore, charging can be performed simply by placing the wireless power receiving device on the desk.

[0035] "Receiving coil position display means" corresponds to step S35 in the embodiment.

[0036] The "program" is a concept including not only a program directly executable by a CPU but also a program in source form, a compressed program, an encrypted program, etc.

Brief Description of the Drawings

[0037]

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Embodiments for Carrying Out the Invention

[0038] 1. First Embodiment 1.1 Overview FIGS. 1A and 1B show the appearance of the wireless power transmission device 6 according to an embodiment of the present invention. In this embodiment, it is constructed as a desk with the wireless power transmission device embedded. FIGS. 1A and 1B are top views of the desk 2. The wireless power transmission device 6 is embedded in a part of the back side of the upper plate 4 of the desk 2.

[0039] As shown in FIG. 1A, a wireless power transmission device 6 is provided with a transmission-side coil 8. On the center line of the transmission-side coil 8, position indicator lights LED10a and LED10b are provided. LED10a and LED10b are constantly lit by the power supplied to the wireless power transmission device 6. LED10a and LED10b are provided on both sides of the transmission-side coil 8 at positions symmetrical to the transmission-side coil 8. Therefore, it is easy for the user to estimate the position of the transmission coil 8.

[0040] Outside of LED10a and LED10b, LED12a and LED12b are provided as power supply indicator lights. LED12a and LED12b are off in the normal state.

[0041] When the user places the smartphone 20, which is a wireless power receiving device, on top of the transmission-side coil 8, the wireless power transmission device 6 determines that it is in a state where power supply is possible and lights up LED12a and LED12b. Thereby, the user can confirm that power supply is being performed.

[0042] Also, since LED10a and LED10b are lit, it is easy to know at which position of the large desk 2 the transmission-side coil 8 is located. Also, since LED10a and LED10b are provided at positions symmetrical to the transmission-side coil 8, by placing the smartphone 20 between them, it becomes easy to place it at an appropriate position. In addition, the receiving-side coil is often provided near the center in the longitudinal direction of the smartphone 20, and since LED10a and LED10b are provided on the center line of the transmission-side coil 8, it is easy to place the smartphone at an appropriate position.

[0043] 1.2 Structure of the Wireless Power Transmission Device FIG. 2A shows a cross-sectional view near the wireless power transmission device 6 provided on the top plate 4 of the desk 2. The top plate 4 is provided with a recess, and the wireless power transmission device 6 is housed in the recess. On the upper surface of the wireless power transmission device 6, a transmission-side coil 8 is provided, and LED10a, LED10b, LED12a, and LED12b are provided on both sides thereof.

[0044] On the top plate 4, a melanin plate 4a having translucency (or other translucent members may be used) is provided, covering the wireless power transmission device 6. The upper surface of the melanin plate 4a serves as the placement surface 18. When the LEDs 10a, 10b, LED 12a, and 12b are lit, the light passes through the melanin plate 4a and can be confirmed by the user. On the other hand, in this embodiment, since the melanin plate 4a is not a transparent member, when the LEDs 10a, 10b, LED 12a, and 12b are turned off, their presence cannot be recognized.

[0045] Fig. 2B shows a cross-sectional view of the wireless power transmission device 6. Below the transmission-side coil 8, a magnetic flux control plate 3 for controlling the magnetic flux is provided. Below that, a heat dissipation plate 5 is provided.

[0046] At the lowermost part, a base plate (not shown) is provided, and a heat dissipation fan 13 is provided thereon. A spacer 11 is arranged between the heat dissipation fan 13 and the heat dissipation plate 5 to form a space. The control unit 60 is housed in that space.

[0047] Fig. 3 shows a perspective view of the wireless power transmission device 6. A transmission coil 8 is provided at the upper part.

[0048] 1.3 Hardware Configuration Fig. 4 shows the control unit of the wireless power transmission device 6 and the control unit of the smartphone 20. An I / O port 32, a demodulation circuit 34, a non-volatile memory 36, and a driver 38 are connected to the CPU 30 of the wireless power transmission device 6. The LEDs 10a, 10b, 12a, and 12b and the motor 15 of the cooling fan 13 are connected to the I / O port 32. The LEDs 10a and 10b are controlled to be constantly lit. Note that the LEDs 10a and 10b may be directly connected to the power supply circuit to be constantly lit.

[0049] The driver 38 controls the frequency and duty ratio of the AC signal applied to the transmission-side coil 8. By such control, the power to be transmitted can be controlled.

[0050] The non-volatile memory 36 stores an operating system 40 (e.g., TRON, etc.) and a control program 42. The control program 42 functions in cooperation with the operating system 40.

[0051] A modulation circuit 52 and a charging circuit 56 are connected to the CPU 50 of the smartphone 20. The CPU 50 is a CPU for controlling wireless charging, and a separate CPU for controlling the entire smartphone 20 is provided. Note that the CPU 50 can exchange data with the CPU for controlling the entire smartphone. The CPU 50 controls each part according to an operating system and a control program recorded in a non-volatile memory (not shown).

[0052] The rectifier circuit 54 rectifies the high-frequency signal received by the receiving coil 58 and converts it into direct current. The charging circuit 56 performs boosting, bucking, etc. to make the output of the rectifier circuit 54 into a desired voltage and charges the secondary battery of the smartphone 20.

[0053] Also, in this embodiment, based on the Qi standard, data can be transmitted from the smartphone 20 side to the wireless power transmission device 6 by backward scatter modulation. The CPU 50 of the smartphone 20 performs data communication as follows. The CPU 50 supplies the data to be transmitted to the modulation circuit 52. The modulation circuit 52 amplitude-modulates the voltage of the receiving coil 58 with the data. This change in amplitude is transmitted to the transmitting coil 8 by electromagnetic induction. The demodulation circuit 34 detects this change in amplitude and demodulates the data. The CPU 30 acquires this.

[0054] As described above, data can be transmitted from the smartphone 20 to the wireless power transmission device 6.

[0055] 1.4 Power Supply Processing Fig. 5 shows a flowchart of the power supply process. The left side is the control program 42 of the wireless power transmission device 6, and the right side is the control program of the smartphone 20.

[0056] The CPU 30 of the wireless power transmission device 6 (hereinafter sometimes abbreviated as the wireless power transmission device 6) controls the driver 38 to apply a voltage of a predetermined frequency to the transmission coil 8 at a predetermined time interval (for example, every 600 msec) (step S1). At this time, if the smartphone 20 is not placed on the placement surface 18, there is no communication from the smartphone 20. Therefore, the wireless power transmission device 6 repeats the voltage application at a predetermined time interval.

[0057] Fig. 6A shows the state near the wireless power transmission device 6 when the smartphone 20 is not placed on the placement surface 18. The LEDs 10a and 10b arranged on the straight line 7 passing through the center point 9 (or its vicinity) of the transmission coil 8 wound in a circular shape are in the lit state. Since the LEDs 10a and 10b are provided at the target positions with the transmission coil 8 interposed therebetween, the user can easily estimate the position of the transmission coil 8. Therefore, it is preferable that the interval between the LEDs 10a and 10b is wider than the width of the smartphone 20.

[0058] Outside the LEDs 10a and 10b, the LEDs 12a and 12b are also provided on the straight line 7. In the state of Fig. 6A, the LEDs 12a and 12b are turned off.

[0059] When the smartphone 20 is placed on the placement surface 18, the AC voltage applied to the transmission coil 8 is transmitted to the reception coil 18 by electromagnetic induction. The CPU 50 of the smartphone 20 (hereinafter sometimes abbreviated as the smartphone 20) determines whether an AC voltage has occurred in the reception coil 18 (step S21). When receiving the AC voltage from the wireless power transmission device 6, step S22 is executed.

[0060] In step S22, the smartphone 20 uses the modulation circuit 52 to amplitude-modulate an AC voltage with data indicating the individual identification information of the smartphone and power transmission conditions (conditions such as the power at which reception is possible). This change in amplitude modulation also occurs in the transmission-side coil 8. The demodulation circuit 34 of the wireless power transmission device 6 demodulates the amplitude-modulated AC voltage to obtain the individual identification information, power transmission conditions, etc. The CPU 30 of the wireless power transmission device 6 acquires this (step S2).

[0061] The wireless power supply device 6 acquires the individual identification information and power transmission conditions, etc. from the smartphone 20, and if the other party's smartphone 20 conforms to the wireless power supply standard used by itself, it controls the LEDs 12a and 12b to light up (step S3). At this time, the wireless power supply device 6 drives the motor 15 to operate the cooling fan 13.

[0062] FIG. 6 shows the state when the smartphone 20 is placed on the placement surface 18. The LEDs 12a and 12b are also lit, indicating that the smartphone 20 is properly placed and power supply is started.

[0063] Next, the wireless power transmission device 6 applies an AC voltage to the transmission coil 8 based on the received power transmission conditions to start power transmission (step S4). The smartphone 20 receives the AC voltage by the reception-side coil 58, and charges the secondary battery (battery) of the smartphone 20 through the rectification circuit 54 and the charging circuit 56.

[0064] The smartphone 20 detects the voltage of the charging circuit 58, etc., and transmits this as power reception state data to the wireless power transmission device 60 using the modulation circuit 52 (step S23).

[0065] The wireless power transmission device 6 acquires power reception state data via the demodulation circuit 34 (step S5). Subsequently, the wireless power transmission device 6 performs feedback control on the power transmission amount based on this power reception state data (step S6). For example, when the received power amount is small, the power transmission amount is increased, and when the received power amount is large, the power transmission amount is decreased for control. Note that the wireless power transmission device 6 controls the power transmission amount by changing the frequency and duty ratio of the AC voltage applied to the transmission coil 8.

[0066] Charging is performed by wireless power supply as described above. The smartphone 20 monitors the control state of the charging circuit 56 and determines whether charging is completed (step S24). If charging is not completed, step S23 is repeatedly executed.

[0067] When charging is completed, the smartphone 20 transmits the charging completion via the modulation circuit 52 (step S25). When the wireless power transmission device 6 receives the charging completion via the demodulation circuit 34 (step S7), it ends the process.

[0068] Note that the wireless power transmission device 6 also ends the process when the smartphone 20 is moved from the placement surface 18 and data communication from the smartphone 20 ceases continuously for a predetermined time. In this case, the wireless power transmission device 6 can turn off the LEDs 12a and 12b to notify the user that charging is not being performed.

[0069] As described above, when placing the smartphone 20 at a predetermined position for charging, the approximate position can be confirmed by the LEDs 10a and 10b. Furthermore, when the smartphone 20 is placed at an appropriate position, it can be confirmed that the LEDs 12a and 12b light up and charging is appropriately performed.

[0070] Note that, for the configuration of the wireless power supply device 6 shown in Fig. 4, a custom IC for wireless power supply such as Kington's KT-CG10W3 or Texas's bp500211 may be used. In this case, when the signal terminal indicating the start of charging becomes ON, the LEDs 12a and 12b may be lit.

[0071] 1.5 Others (1) In the above embodiment, the position marks, the LEDs 10a and 10b, and the power supply indicator lights, the LEDs 12a and 12b, are arranged on the center line of the transmission-side coil 8 (or on a line separated from the center line by 10 mm or less). However, it is not necessary to arrange them on the center line of the transmission-side coil 8.

[0072] However, it is preferable to provide at least the position marks on the center line in order to facilitate position confirmation. For example, as shown in Fig. 7A, only one LED 12 as the power supply indicator light may be provided in the upper left.

[0073] (2) In the above embodiment, the position marks, the LEDs 10a and 10b, and the power supply indicator lights, the LEDs 12a and 12b, are used as dot-like light sources. However, as shown in Fig. 7B, linear LEDs 10 and 12 may be used. The LED 10 as the position mark is constantly lit, and the LED 12 as the power supply indicator light is controlled to be lit during power supply. In this case, the lengths of the LEDs 10 and 12 are preferably larger than the width of the smartphone 20.

[0074] Also, a combination of linear LEDs and dot-like LEDs may be used. Furthermore, characters (such as the character "charging position") or symbols may be displayed as the position marks by a display light source. Similarly, a display light source that displays characters (such as the character "charging") or symbols may be used as the power supply indicator light.

[0075] (3) In the above embodiment, LEDs are used. However, other displays such as organic ELs and liquid crystals may be used.

[0076] Furthermore, a display may be provided on the wireless power transmission device 6, and position marks and power supply indications may be provided on this display.

[0077] (4) In the above embodiment, the position marks are constituted by the LEDs 10a and 10b which are light sources. However, printing applied to the mounting surface 18, or recesses and protrusions or the like may be provided as the position marks. Also, members having different colors or the like may be embedded as the position marks. FIG. 7C shows an example in the case where the position marks are printing marks 70a and 70b. In the case of position marks such as printing, they may be lines instead of dots. Furthermore, they may be characters, symbols, or the like.

[0078] (5) In the above embodiment, the LEDs 10a and 10b which are position marks and the LEDs 12a and 12b which are power supply indication lights are arranged on the horizontal center line 7. However, as shown in FIG. 7D, the LEDs 10c and 10d which are position marks and the LEDs 12c and 12d which are power supply indication lights may also be arranged on the vertical center line 17. Also, the LEDs 10c and 10d which are position marks and the LEDs 12c and 12d which are power supply indication lights may be arranged only on the vertical center line 17.

[0079] (6) In addition to the above embodiment, when the start of power reception is detected on the side of the smartphone 20 (steps S22, S23), the CPU that controls the entire smartphone 20 may obtain this and perform the following processing. The CPU reads out the position of the receiving coil of its own device recorded in advance. The position of the receiving coil for positioning is displayed at the position on the display corresponding to that position.

[0080] FIG. 8 shows an example of the display of the position of the receiving coil on the display. It is preferable for power transmission that the positions of the transmitting coil 8 and the receiving coil 18 do not deviate. Even if there is a slight deviation, power transmission is possible, but the efficiency will decrease.

[0081] In the case of the example in FIG. 8, the mark 80 indicating the position of the receiving coil 18 is slightly shifted downward from the LEDs 10a and 10b of the position mark indicating the position of the transmitting coil 8. The user can move the smartphone 20 to align the two. At this time, the horizontal center line 82 displayed on the display serves as a guide for alignment.

[0082] In addition, when the positions are shifted horizontally (particularly effective in the case of a tablet, etc.), the vertical center line 84 can be used as a guide for alignment.

[0083] Also, in FIG. 8, the LEDs 12a and 12b are provided as power supply indicator lights, but the receiving coil position display 80 may be used as the power supply indication, and the LEDs 12a and 12b may not be provided.

[0084] (7) In the above embodiment, the LEDs 10a and 10b as position marks and the LEDs 12a and 12b as power supply indicator lights are provided. However, as shown in FIG. 9, they may be configured by common LEDs 11a and 11b.

[0085] As shown in FIG. 9A, while the smartphone 20 is not placed, the LEDs 11a and 11b are controlled by the CPU 30 to emit light in the first color (for example, orange). As shown in FIG. 9B, when the smartphone 20 is placed, the LEDs 11a and 11b are controlled by the CPU 30 to emit light in the second color (for example, blue).

[0086] Note that they may emit light in the same color, and the light emission mode (such as the lighting interval) may be changed for distinction.

[0087] (8) In the above embodiment, LEDs 10a, 10b, 12a, and 12b are provided under the non-transparent and translucent melanin plate 4a. However, LEDs 10a, 10b, 12a, and 12b may be provided under a transparent thin plate so that their presence can be confirmed even when they are turned off. Alternatively, without covering LEDs 10a, 10b, 12a, and 12b with the melanin plate 4a, their presence may be confirmed even when they are turned off.

[0088] In this case, before the smartphone 20 is placed, they may be turned off and made to light up when placed. The unlit LEDs 11a and 11b will serve as position marks. The light source may not be dot-shaped but may be linear or used as a basis for displaying characters or symbols.

[0089] (8) In the above embodiment, the smartphone 20 is taken as an example for explaining the wireless power receiving device. However, it can be generally applied to devices that require power supply, such as tablet computers, personal computers, notebook computers, small lighting appliances such as desktop fans and task lights, transmitters such as Wi-Fi, and shoes equipped with GPS receivers. Also, in the above embodiment, the case of charging has been described, but it can be similarly applied to devices that operate by wireless power supply without charging.

[0090] (9) In the above embodiment, the case where the wireless power transmission device 6 is embedded in the desk has been described. However, as long as it can place a wireless power receiving device such as the smartphone 20, it may be embedded in other furniture such as a table and a shoe box, or on the floor surface and the wall surface (a mechanism for holding the smartphone 20 is required).

[0091] Also, without embedding the wireless power receiving device 6, it may be used alone as a charging device or a power supply device.

[0092] (10) In the above embodiment, wireless power supply based on the Qi standard has been described, but it can also be applied to wireless power supply based on other methods such as the PMA standard and the Rezence standard.

[0093] (11) The above-described embodiments and their modifications can be implemented in combination with other embodiments and their modifications as long as they do not conflict with their essence.

[0094] 2. Second Embodiment 2.1 Overview FIG. 10 shows an overview of a wireless power transmission system according to the second embodiment. In this embodiment, an NFC transceiver 25 is provided in the wireless power transmission device 6.

[0095] When the NFC transceiver (not shown) of the smartphone 20 approaches the wireless power transmission device 6, it can receive a signal from the NFC transceiver 25 and detect that the wireless power transmission device 6 is nearby.

[0096] The smartphone 20 acquires the remaining battery level of its own device. If the remaining level is below a predetermined value, it displays a message on the display indicating that it is preferable to charge. Further, it reads out the position of the receiving coil for wireless power supply recorded in its own device and displays a receiving coil position display 80 at the corresponding position on the display.

[0097] The user who wants to charge places the smartphone 20 between the LEDs 10a and 10b as position marks. At this time, the receiving coil position display 80 displayed on the display of the smartphone 20 enables accurate positioning.

[0098] When the smartphone 20 is placed, the LEDs 12a and 12b, which are power supply indicator lights, light up in the same manner as in the first embodiment.

[0099] According to this embodiment, when the remaining battery level of the smartphone 20 or the like is low, if there is a wireless power transmission device 6 nearby, a message prompting charging can be displayed on the smartphone 20.

[0100] Furthermore, since the position of the receiving coil is displayed on the display, alignment is easy.

[0101] 2.2 Structure of the Wireless Power Transmission Device The basic structure of the wireless power transmission device 6 is the same as that of the first embodiment. However, it is different in that the NFC transceiver 25 is provided. The NFC transceiver 25 may be provided integrally with the wireless power transmission device 6, or may be provided separately.

[0102] 2.3 Hardware Configuration Fig. 11 shows the hardware configurations of the wireless power transmission device 6 and the smartphone 20. The configuration of the wireless power transmission device 6 is the same as that of the first embodiment, but it is different in that the NFC transceiver 25 is connected to the CPU 30 and can be controlled by the CPU 30.

[0103] In Fig. 11, a CPU 90 that controls the entire smartphone 20 is shown. A touch display 92, an NFC transceiver 95, a communication circuit 97, and a non-volatile memory 94 are connected to the CPU 90. The communication circuit 97 is for connecting to the Internet. In the figure, a call circuit and the like are omitted. Also, the CPU 90 is configured to be able to exchange data with a CPU 50 for controlling wireless power supply.

[0104] An operating system 96 and a control program 98 are recorded in the non-volatile memory 94. The control program 98 exhibits its function in cooperation with the operating system 96.

[0105] 2.4 Power Supply Processing Figs. 12 and 13 show flowcharts of the power supply processing. In Fig. 12, the left side is the processing of the control program 42 of the wireless power transmission device 6, and the right side is the processing of the control program 98 of the smartphone 20.

[0106] The CPU 30 of the wireless power transmission device 6 (hereinafter sometimes abbreviated as the wireless power transmission device 6) applies an alternating voltage to the transmission coil 8 at predetermined time intervals (step S1). This process is the same as that of the first embodiment.

[0107] Also, the wireless transmission device 6 controls (or autonomously) the NFC transceiver 25 to transmit a polling signal (step S11). As shown in FIG. 10, when there is a smartphone 20 in the vicinity of the wireless power transmission device 6, the NFC transceiver 95 of the smartphone 20 receives this polling signal and establishes communication by performing confirmation of the communication method, confirmation of the other party, etc. with the NFC transceiver 25 (steps S12, S32).

[0108] When communication is established between the CPU 90 of the smartphone 20 (hereinafter sometimes abbreviated as the smartphone 90) and the NFC transceiver 25 of the wireless power transmission device 6, it knows that the wireless power transmission device 6 is present in the vicinity. The smartphone 20 determines whether its own battery remaining amount is below a predetermined value (for example, 30% or less) (step S33). If it is not below the predetermined value and there is sufficient remaining amount, step S21 in FIG. 13 is executed.

[0109] If it is below the predetermined value and there is not enough remaining amount, the smartphone 20 displays a recommendation that it is preferable to charge on the touch display 92 (step S34). An example of the displayed recommendation is shown in FIG. 14.

[0110] Subsequently, the smartphone 20 reads out the position information of its own reception coil 58 recorded in the non-volatile memory 94. The position of the reception coil 58 is determined for each model of the smartphone 20. This is recorded in the non-volatile memory 94 in advance.

[0111] In addition, a server device (not shown) that has previously investigated the positions of the receiving coils 58 for each model of each manufacturer and recorded them in association with the model numbers may be prepared, and the model number may be transmitted thereto to obtain the positions of the receiving coils 58.

[0112] In this embodiment, a DB that represents the position of the receiving coil 58 is recorded in the server device by indicating the position of the center point of the receiving coil 58 using XY coordinates in the horizontal direction (Y) and the vertical direction (X) with the lower left of the touch display 92 as the origin.

[0113] Also, although the size of the receiving coil 58 varies depending on the model, in this embodiment, it is assumed to be the same size. This is because it is only necessary to know the center point. Of course, the size of the receiving coil 58 may also be registered in the DB.

[0114] The smartphone 20 performs the receiving-side coil position display 80 at the position on the touch display 92 corresponding to the acquired position of the receiving coil 58 (step S35). FIG. 14 shows an example of the receiving-side coil position display 80.

[0115] Since the user can know that the receiving-side coil 58 is at this position, the user can easily and surely perform alignment by aligning the line connecting the position marks 10a and 10b of the desk 2 with the center line 99 of the receiving-side coil position display 80.

[0116] Note that the receiving-side coil position display 80 may display the one as shown in FIG. 8.

[0117] The processing after the smartphone 20 is placed at the position in FIG. 10B is the same as that in the first embodiment (see FIG. 13).

[0118] As described above, according to this embodiment, when the battery level is low, it is possible to indicate that there is a wireless power transmission device 6 nearby, and moreover, it is possible to perform a display that facilitates alignment.

[0119] 2.5 Others (1) In the above embodiment, both charging recommendation and reception-side coil position display are performed. However, only one of them may be performed.

[0120] Also, the above processing (charging recommendation and reception-side coil position display) is performed only when the remaining battery level is below a predetermined value. However, these processes may be performed regardless of the remaining battery level.

[0121] (2) In the above embodiment, the charging recommendation is made by displaying on the touch display 92. However, it may be output by voice or vibration (controlled to operate the vibrator by the CPU 90).

[0122] (3) The above embodiment and its modified examples can be implemented in combination with other embodiments and their modified examples as long as it does not go against its essence.

Claims

1. A transmitting coil for wireless power transmission with a receiving coil of a wireless power receiving device, a mounting surface provided on the transmitting coil for mounting the wireless power receiving device, the mounting surface having position marks for indicating positions where the wireless power receiving device is to be mounted on both sides of the transmitting coil on a line passing through the vicinity of the center of the transmitting coil, a control unit that acquires information data from the wireless power receiving device via the transmitting coil and controls power supply to the transmitting coil, in a wireless power transmission device including: a light emitter is provided on the mounting surface, the control unit determines whether power can be supplied from the transmitting coil to the receiving coil directly or indirectly based on information data from the wireless power receiving device, and if it determines that power cannot be supplied, sets the light emitter to a first state, and if it determines that power can be supplied, sets the light emitter to a second state, in a wireless power transmission device characterized by: the wireless power transmission device characterized in that the light emitter is used as the position mark.

2. In the wireless power transmission device according to Claim 1, the wireless power transmission device characterized in that the light emitter is provided outside the position mark on a line passing through the vicinity of the center of the transmitting coil.

3. In the wireless power transmission device according to Claim 1 or 2, the wireless power transmission device characterized in that the light emitter includes a linear light source arranged along a line passing through the vicinity of the center of the transmitting coil.

4. In the wireless power transmission device according to any one of Claims 1 to 3, the first state is being turned off, the wireless power transmission device characterized in that the second state is being turned on.

5. In the wireless power transmission device according to any one of Claims 1 to 3, the first state is lighting with a first color, the wireless power transmission device characterized in that the second state is lighting with a second color.

6. In the wireless power transmission device according to any one of Claims 1 to 3, the wireless power transmission device characterized in that the first state and the second state are distinguished and represented by changing a lighting mode of the light emitter or the number of light emitters to be lit.

7. In any system or device according to Claims 1 to 6, the wireless power transmission device is a desk having a mounting surface as a desk surface.

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