Power supply system and power supply method

Abstract

To provide a power-feeding system capable of staring power-feeding to a power-receiving device having no power required for an operation, and to provide a power-feeding method therefor.SOLUTION: A power transmission part transmits first power, second power larger than the first power, and third power larger than the first power to a power-receiving device. A first authentication part authenticates the power-receiving device after the power transmission part transmits the first power to the power-receiving device. A second authentication part authenticates the power-receiving device after the power transmission part transmits the second power to the power-receiving device. The power transmission part transmits the second power to the power-receiving device after the first authentication part authenticates the power-receiving device. The power transmission part transmits the third power to the power-receiving device after the second authentication part authenticates the power-receiving device.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a power supply system and a power supply method.

Background Art

[0002] There is a technology for power supply by means of wired power supply using a socket or the like, or wireless power supply as defined by an international standard such as Qi. For example, Patent Document 1 discloses a technology for determining power supply conditions using a neural network.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] A power supply system for performing wireless power supply over a medium to long distance has a power transmission device and a power reception device. The power reception device periodically transmits a beacon signal. The power transmission device recognizes the presence of the power reception device by receiving the beacon signal. Authentication of the power reception device is executed as necessary, and power supply to the power reception device is started.

[0005] However, when the power reception device does not have the power necessary for operation, the power reception device cannot transmit a beacon signal. Therefore, power supply to the power reception device is not started.

[0006] The present invention has been made in view of the above problems, and an object thereof is to provide a power supply system and a power supply method capable of starting power supply to a power reception device that does not have the power necessary for operation.

Means for Solving the Problems

[0007] The present invention relates to a power supply system comprising: a power transmission unit that transmits a first power, a second power greater than the first power, and a third power greater than the first power to a power receiving device; a first authentication unit that authenticates the power receiving device after the power transmission unit has transmitted the first power to the power receiving device; and a second authentication unit that authenticates the power receiving device after the power transmission unit has transmitted the second power to the power receiving device, wherein after the first authentication unit authenticates the power receiving device, the power transmission unit transmits the second power to the power receiving device, and after the second authentication unit authenticates the power receiving device, the power transmission unit transmits the third power to the power receiving device.

[0008] The present invention is a power supply method comprising the steps of: a power transmission unit transmitting a first power to a power receiving device; a first authentication unit authenticating the power receiving device after the power transmission unit has transmitted the first power to the power receiving device; a power transmission unit transmitting a second power greater than the first power to the power receiving device after the first authentication unit has authenticated the power receiving device; a second authentication unit authenticating the power receiving device after the power transmission unit has transmitted the second power to the power receiving device; and a third power greater than the first power to the power transmission unit transmitting the power receiving device after the second authentication unit has authenticated the power receiving device. [Effects of the Invention]

[0009] According to the present invention, the power supply system and power supply method can initiate power supply to a power receiving device that does not have the power necessary for operation. [Brief explanation of the drawing]

[0010] [Figure 1] This is a block diagram showing the configuration of a power supply system according to a first embodiment of the present invention. [Figure 2] This is a block diagram showing the configuration of a power supply control server according to a first embodiment of the present invention. [Figure 3] This figure shows an example of registration information in the first embodiment of the present invention. [Figure 4]This is a block diagram showing the configuration of a TX (power transmission device) according to a first embodiment of the present invention. [Figure 5] This is a block diagram showing the configuration of an RX (power receiving device) according to the first embodiment of the present invention. [Figure 6] This figure shows the processing flow performed by the power supply system according to the first embodiment of the present invention. [Figure 7] This figure shows the processing flow performed by the power supply system according to the first embodiment of the present invention. [Figure 8] This is a block diagram showing the configuration of a TX (power transmission device) according to a modification of the first embodiment of the present invention. [Figure 9] This figure shows the processing flow performed by a power supply system according to a modified version of the first embodiment of the present invention. [Figure 10] This figure shows the processing flow performed by the power supply system according to the second embodiment of the present invention. [Figure 11] This figure shows the processing flow performed by a power supply system according to a modified version of the second embodiment of the present invention. [Modes for carrying out the invention]

[0011] Embodiments of the present invention will be described below with reference to the drawings.

[0012] (First Embodiment) A first embodiment of the present invention will be described. Figure 1 shows an example of the configuration of a power supply system 1 according to the first embodiment. The power supply system 1 is applied to a service that supplies power to an RX30 (hereinafter referred to as the power supply service). The power supply system 1 includes, for example, a power supply control server 10 and a plurality of TX20s (TX20-1 to 20-4). The power supply control server 10 is a server device managed by the operator providing the power supply service. The TX20s are power transmission devices that transmit power according to the control of the power supply control server 10. The RX30 is a power receiving device that receives power transmitted from the TX20s.

[0013] Each of the TX20s is provided in the power supply areas E1 to E3, and there are a plurality of RXs (power receiving devices) 30 in the power supply areas E1 to E3. In the example of this figure, TX20-1 is provided in the power supply area E1, and RX30A-1 to 30A-L exist. TX20-2 and 20-3 are provided in the power supply area E2, and RX30B-1 to 30B-M, RX30C-1 to 30C-N, and RX30D-1 to 30D-O exist. TX20-4 is provided in the power supply area E3, and RX30E-1 to 30E-P exist. Each of L, M, N, O, and P is an arbitrary natural number. Each of the TX20s supplies power to the RX30s existing in the power supply areas E1 to E3 where each of the TX20s is provided according to the control of the power supply control server 10.

[0014] Figure 2 shows the configuration of the power supply control server 10. The power supply control server 10 includes, for example, a communication unit 11, a storage unit 12, and a control unit 13. The communication unit 11 communicates with the TX20. The storage unit 12 stores, for example, registration information 120.

[0015] Figure 3 shows an example of the registration information 120. The registration information 120 is information about the registrants who receive the power supply service. The registration information 120 is created for each registrant. The registration information 120 is composed of information corresponding to items such as a registrant ID, a subscribed plan, and registered devices, for example. The registrant ID is information that uniquely identifies the registrant registered as a user who receives the power supply service. The subscribed plan is information about the plan subscribed by the registrant in the power supply service.

[0016] The registered device is information regarding a device (RX30) registered by a registrant as an object to be powered by a power supply service. As shown in the example of this figure, multiple devices (Device 1, Device 2, …) may be shown as registered devices. As information regarding the device, information corresponding to each item such as a device ID, a password, and a power supply specification is shown. The device ID is identification information that uniquely identifies the device. The password is a password used for authentication to determine whether to execute power supply to RX30. For example, when TX20 requests a password from RX30 and the password obtained from the RX30 matches the password pre-registered in the registration information 120, power supply to the RX30 is started. The power supply specification is a power supply specification when powering the device and includes, for example, the maximum power and maximum voltage that the device can receive power.

[0017] The storage unit 12 is a storage medium such as an HDD (Hard Disk Drive), a flash memory, an EEPROM (Electrically Erasable Programmable Read Only Memory), a RAM (Random Access read / write Memory), or a ROM (Read Only Memory), or a combination thereof. The storage unit 12 stores a program for executing various processes of the power supply control server 10 and temporary data used when executing various processes.

[0018] The control unit 13 includes, for example, an acquisition unit 130, an authentication unit 131, and a power supply control unit 132. Each of these functional units included in the control unit 13, that is, the acquisition unit 130, the authentication unit 131, and the power supply control unit 132, is realized by causing a CPU (Central Processing Unit) included in the power supply control server 10 as hardware to execute a program.

[0019] The acquisition unit 130 acquires various types of information. For example, the acquisition unit 130 acquires information used to perform authentication, such as the device ID and password notified from RX30 via TX20, via the communication unit 11. The authentication unit 131 performs authentication using the device ID and password acquired by the acquisition unit 130. The power supply control unit 132 controls the power supply performed by TX20.

[0020] Figure 4 shows the configuration of TX20. TX20 comprises, for example, a communication unit 21, a storage unit 22, and a control unit 23. The communication unit 21 communicates with the power supply control server 10 and RX30. The communication unit 21 may have a first communication unit that communicates with the power supply control server 10 and a second communication unit that communicates with RX30. For example, the first communication unit communicates with the power supply control server 10 via wireless or wired communication. The second communication unit communicates with RX30 via wireless communication.

[0021] The storage unit 22 is a storage medium such as an HDD, flash memory, EEPROM, RAM, or ROM, or a combination thereof. The storage unit 22 stores programs for executing various processes of the TX20, and temporary data used when executing these processes.

[0022] The control unit 23 includes, for example, an acquisition unit 230, a detection unit 231, a communication control unit 232, and a power supply unit 233. Each of these functional units of the control unit 23, namely the acquisition unit 230, the detection unit 231, the communication control unit 232, and the power supply unit 233, is realized by having the CPU, which is provided as hardware in the TX20, execute a program.

[0023] The acquisition unit 230 acquires various types of information. For example, the acquisition unit 230 acquires beacon signals that RX30 periodically transmits via the communication unit 21. The acquisition unit 230 outputs the acquired beacon signals to the detection unit 231. The detection unit 231 detects RX30 based on the beacon signals.

[0024] The communication control unit 232 controls communication with the power supply control server 10 and with RX30. TX20 has an antenna (not shown), and the power supply unit 233 supplies power to RX30 by transmitting radio waves. Any method can be used for power supply by the power supply unit 233. For example, a method using electromagnetic induction, radio wave reception, or resonance can be employed.

[0025] Figure 5 shows the configuration of RX30. RX30 includes, for example, a communication unit 31, a storage unit 32, a control unit 33, and a battery 34. The communication unit 31 communicates with TX20.

[0026] The storage unit 32 is a storage medium such as an HDD, flash memory, EEPROM, RAM, or ROM, or a combination thereof. The storage unit 32 stores programs for executing various processes of the RX30, and temporary data used when executing these processes. For example, the storage unit 32 stores the device ID and password.

[0027] The control unit 33 includes, for example, an acquisition unit 330, a communication control unit 331, and a power receiving unit 332. Each of these functional units of the control unit 33, namely the acquisition unit 330, the communication control unit 331, and the power receiving unit 332, is realized by having the CPU, which is provided as hardware in the RX30, execute a program.

[0028] The acquisition unit 330 acquires various types of information. For example, the acquisition unit 330 acquires signals transmitted from the TX20 via the communication unit 21. The acquisition unit 330 outputs the acquired signals to the communication control unit 331. The communication control unit 331 controls communication with the TX20. The RX30 has an antenna (not shown), and the power receiving unit 332 receives power. The power receiving unit 332 receives radio waves for power supply transmitted from the power supply unit 233 of the TX20 and uses the received radio waves to store power in the battery 34. The RX30 may also be a device that performs processing within the limits of what is possible with the power received from the TX20, without having a battery 34.

[0029] Figures 6 and 7 illustrate the processing flow performed by the power supply system 1. Figures 6 and 7 show the processing flow performed by the power supply system 1. After the processing shown in Figure 6 is executed, the processing shown in Figure 7 is executed.

[0030] Before the process shown in Figure 6 is executed, it is assumed that the battery level of the RX30's battery 34 is 0 and the RX30 is not running. Alternatively, it is assumed that the RX30 does not have a battery 34 and the RX30 is not running. Below, we will explain an example where the RX30 has a battery 34. The following process can also be applied to the case where the RX30 does not have a battery 34.

[0031] Even if the RX30 is not running, the power receiving unit 332 can receive radio waves transmitted from the TX20 and charge the battery 34. The remaining charge of the battery 34 may be less than the power required to transmit the beacon signal, even if the RX30 is running.

[0032] (Step S1) TX20 transmits a first power to RX30. Specifically, the power supply unit 233 transmits radio waves to RX30 necessary to store the first power in the battery 34. The power receiving unit 332 receives these radio waves and stores the first power in the battery 34. The first power is the minimum power required for RX30 to start up. For example, the first power is more than the power required for RX30 to start up and transmit a beacon signal.

[0033] (Step S2) After the first power is stored in battery 34, the RX30 starts up. If the battery 34's remaining charge is greater than 0 and the RX30 is already running, this step is not performed.

[0034] (Step S3) The communication control unit 331 of the RX30 generates a beacon signal containing the device ID stored in the memory unit 32 and outputs the beacon signal to the communication unit 31. The communication unit 31 transmits the beacon signal. The communication unit 31 transmits the beacon signal periodically.

[0035] (Step S4) The communication unit 21 of TX20 receives the beacon signal transmitted from RX30. The acquisition unit 230 acquires the beacon signal via the communication unit 21. The acquisition unit 230 outputs the acquired beacon signal to the detection unit 231. The detection unit 231 receives the beacon signal from the acquisition unit 230 and determines that an RX30 corresponding to that device ID exists if the acquired beacon signal contains a device ID. The detection unit 231 outputs the determination result along with the beacon signal to the communication control unit 232.

[0036] (Step S5) If the detection unit 231 determines that RX30 is present, the communication control unit 232 generates an authentication request to request first authentication from the power supply control server 10 and outputs the authentication request to the communication unit 21. The authentication request includes the device ID contained in the beacon signal acquired by the acquisition unit 230. The first authentication is a simplified authentication. The communication unit 21 transmits the authentication request to the power supply control server 10.

[0037] (Step S6) The communication unit 11 of the power supply control server 10 receives an authentication request sent from TX20. The acquisition unit 130 acquires the device ID included in the authentication request via the communication unit 11. The authentication unit 131 performs the first authentication. Specifically, the authentication unit 131 determines whether the same device ID as the acquired device ID is included in the registration information 120 of the storage unit 12. If the same device ID as the acquired device ID is included in the registration information 120, authentication is successful. If the same device ID as the acquired device ID is not included in the registration information 120, authentication fails.

[0038] (Step S7) The authentication unit 131 outputs an authentication result indicating the result of the first authentication to the communication unit 11. The communication unit 11 transmits the authentication result to the TX20.

[0039] (Step S8) The communication unit 21 of TX20 receives the authentication result transmitted from the power supply control server 10. The acquisition unit 230 acquires the authentication result via the communication unit 21. If the authentication result indicates authentication failure, the process shown in Figures 6 and 7 ends. If the authentication result indicates authentication success, TX20 transmits a second power to RX30. Specifically, the power supply unit 233 transmits radio waves to RX30 necessary to store the second power in the battery 34. The power receiving unit 332 receives these radio waves and stores the second power in the battery 34. The second power is greater than the first power and is the power required for RX30 to perform the second authentication. For example, the second power is greater than or equal to the power required for RX30 to transmit the information necessary for the second authentication to TX20. The second authentication is performed when the first authentication is successful and is necessary for RX30 to receive the power required for various operations from TX20.

[0040] (Step S9) The communication control unit 232 of TX20 generates a password request to request a password and outputs the password request to the communication unit 21. The communication unit 21 transmits the password request to RX30.

[0041] (Step S10) The communication unit 31 of RX30 receives a password request sent from TX20. The acquisition unit 330 acquires the password request via the communication unit 31. The communication control unit 331 generates a password response containing the password and device ID stored in the storage unit 32 and outputs the password response to the communication unit 31. The communication unit 31 sends the password response to TX20.

[0042] (Step S11) The communication unit 21 of TX20 receives the password response sent from RX30. The acquisition unit 230 acquires the password response via the communication unit 21. The communication control unit 232 generates an authentication request to request a second authentication from the power supply control server 10 and outputs the authentication request to the communication unit 21. The authentication request includes the password and device ID contained in the password response acquired by the acquisition unit 230. The communication unit 21 sends the authentication request to the power supply control server 10.

[0043] (Step S12) The communication unit 11 of the power supply control server 10 receives an authentication request sent from TX20. The acquisition unit 130 acquires the password and device ID included in the authentication request via the communication unit 11. The authentication unit 131 performs a second authentication. Specifically, the authentication unit 131 determines whether the same password as the acquired password is included in the registration information 120 of the storage unit 12, and whether the same device ID as the acquired device ID is included in the registration information 120 of the storage unit 12. If the same password as the acquired password is included in the registration information 120 of the storage unit 12, and the same device ID as the acquired device ID is included in the registration information 120, authentication is successful. If the same password as the acquired password is not included in the registration information 120 of the storage unit 12, or if the same device ID as the acquired device ID is not included in the registration information 120, authentication fails.

[0044] (Step S13) The authentication unit 131 outputs an authentication result indicating the result of the second authentication to the communication unit 11. The communication unit 11 transmits the authentication result to the TX20.

[0045] (Step S14) The communication unit 21 of TX20 receives the authentication result transmitted from the power supply control server 10. The acquisition unit 230 acquires the authentication result via the communication unit 21. If the authentication result indicates authentication failure, the process shown in Figures 6 and 7 ends. If the authentication result indicates authentication success, TX20 transmits a third power to RX30. Specifically, the power supply unit 233 transmits radio waves to RX30 necessary to store the third power in the battery 34. The power receiving unit 332 receives these radio waves and stores the third power in the battery 34. The third power is greater than the first power and is the power required for the normal operation of RX30. The third power is the same as the second power or different from the second power. The third power may be greater than the second power or less than the second power.

[0046] RX30 may transmit a beacon signal containing a simple password instead of a device ID, and TX20 may send an authentication request containing the simple password to the power supply control server 10. The power supply control server 10 may perform the first authentication using the simple password. For example, a simple password may be stored in the storage unit 32 of RX30 when the RX30 is shipped as a product. When the information of RX30 is registered with the power supply control server 10, a simple password may be registered in the registration information 120 of the storage unit 12 of the power supply control server 10.

[0047] RX30 may send information including its digital signature and public key to TX20 instead of a device ID and password, and TX20 may send an authentication request including that information to the power supply control server 10. The power supply control server 10 may perform a second authentication by verifying RX30's digital signature using RX30's public key.

[0048] The power required to start up an RX30 may vary from one RX30 to another. For example, one RX30 may start up with the first power level, while another cannot. Therefore, the TX20 may repeatedly transmit power, gradually increasing it between the first and second power levels. Even if the power required to start up an RX30 varies from one RX30 to another, the TX20 can reliably transmit the power required to start up an RX30.

[0049] RX30 may transmit a beacon signal containing information indicating that there is no power (the battery level of 34 is 0). If a beacon signal containing information indicating no power is received and the first authentication by the power supply control server 10 is successful, TX20 may preferentially transmit a second power to the RX30 that transmitted the beacon signal. TX20 can transmit power to only specific RX30s by using a directional antenna.

[0050] As described above, the power supply unit 233 (power transmission unit) transmits a first power, a second power greater than the first power, and a third power greater than the second power to the RX30 (power receiving device). After the power supply unit 233 transmits the first power to the RX30, the authentication unit 131 (first authentication unit) authenticates the RX30. After the authentication unit 131 authenticates the RX30, the power supply unit 233 transmits the second power to the RX30. After the power supply unit 233 transmits the second power to the RX30, the authentication unit 131 (second authentication unit) authenticates the RX30. After the authentication unit 131 authenticates the RX30, the power supply unit 233 transmits the third power to the RX30.

[0051] When the power supply unit 233 transmits a first power to RX30, RX30 starts up and can transmit the information necessary for the first authentication to TX20. When the power supply unit 233 transmits a second power to RX30, RX30 can transmit the information necessary for the second authentication to TX20. When the power supply unit 233 transmits a third power to RX30, RX30 can perform various operations. Therefore, the power supply system 1 can start supplying power to RX30, which does not have the power necessary for operation.

[0052] Before the power supply unit 233 transmits the first power to RX30, the battery 34 has zero charge and RX30 is not running. Alternatively, RX30 does not have a battery 34 and RX30 is not running. After the power supply unit 233 transmits the first power to RX30, RX30 starts up. After RX30 starts up, the authentication unit 131 authenticates RX30. Even if RX30 has no power and is not running, the power supply system 1 can start supplying power to RX30.

[0053] It is possible that not all RX30s in a single power supply area have batteries 34. If the TX20 always transmits a predetermined power (e.g., third power), the RX30s can start up and operate. However, the power transmission efficiency is poor because the TX20 transmits unnecessary power. If the TX20 always transmits less power than the predetermined power (e.g., second power), the operation of the RX30s will be limited. The power supply system 1 described above has good power transmission efficiency and can reliably transmit the power necessary for the operation of the RX30s.

[0054] In a system where power supply is initiated without authentication, power receiving devices can receive power without being authenticated. Because the authentication required to receive the power supply service is not performed, power receiving devices that are not participating in the power supply service can receive power. However, this situation is undesirable. In the power supply system 1 described above, only RX30 authenticated by the power supply control server 10 receives the third power supply, so power receiving devices that are not participating in the power supply service cannot receive the power necessary for operation.

[0055] In a system where power supply is initiated only to authenticated powered devices after authentication is performed, powered devices without power will not be authenticated and will not be able to receive power. Therefore, such powered devices must receive power in advance by using wired communication such as USB before being authenticated. In the power supply system 1 described above, RX30 does not need to receive power in advance other than the power transmitted from TX20. Also, even if RX30 does not have a battery 34, power supply system 1 can start supplying power to RX30.

[0056] As described above, the authentication unit 131 authenticates RX30 by using the device ID (first information) received from RX30 via TX20. The authentication unit 131 also authenticates RX30 by using the device ID and password (second information) received from RX30 via TX20.

[0057] After the power supply unit 233 transmits the first power to RX30, RX30 transmits a beacon signal including the device ID. TX20 receives the beacon signal, obtains the device ID, and transmits the obtained device ID to the power supply control server 10. After the power supply unit 233 transmits the second power to RX30, RX30 transmits the device ID and password. TX20 receives the device ID and password and transmits the received device ID and password to the power supply control server 10.

[0058] The RX30 can transmit the information required for the first authentication to the TX20 by using the first power supply. The RX30 can transmit the information required for the second authentication to the TX20 by using the second power supply.

[0059] (Modified version of the first embodiment) A modified example of the first embodiment of the present invention will now be described. In the modified example of the first embodiment, the TX20a shown in Figure 8 is used instead of the TX20 shown in Figure 4.

[0060] Figure 8 shows the configuration of TX20a. TX20a includes, for example, a communication unit 21, a storage unit 22, and a control unit 23a. The explanation of the configuration is the same as that shown in Figure 4 and will be omitted.

[0061] TX20a is equipped with a control unit 23a instead of the control unit 23 shown in Figure 4. The control unit 23a includes, for example, an acquisition unit 230, a detection unit 231, a communication control unit 232, a power supply unit 233, and an authentication unit 234.

[0062] The descriptions of the acquisition unit 230, detection unit 231, communication control unit 232, and power supply unit 233 are omitted. The authentication unit 234 performs the first authentication. In a modified example of the first embodiment, TX20a performs the first authentication instead of the power supply control server 10.

[0063] Figure 9 will be used to explain the processing flow performed by the power supply system 1. Figure 9 shows the processing flow performed by the power supply system 1. The explanation of the same processing as shown in Figure 6 or Figure 7 will be omitted.

[0064] After the information of RX30 is registered in the registration information 120 of the storage unit 32 of the power supply control server 10, the communication unit 11 of the power supply control server 10 sends the device ID of RX30 to TX20. The communication unit 21 of TX20 receives the device ID from the power supply control server 10. The acquisition unit 230 acquires the device ID via the communication unit 21. The storage unit 22 stores the device ID.

[0065] The process performed by TX20 from receiving the beacon signal transmitted from RX30 to detecting RX30 (steps S1 to S4) is the same as the process shown in Figure 6.

[0066] (Step S20) The authentication unit 234 performs the first authentication. Specifically, the authentication unit 234 determines whether the same device ID as the device ID included in the beacon signal is stored in the storage unit 22. If the same device ID as the device ID included in the beacon signal is stored in the storage unit 22, authentication is successful. If the same device ID as the device ID included in the beacon signal is not stored in the storage unit 22, authentication fails.

[0067] If authentication fails, the process shown in Figure 9 terminates. If authentication is successful, as described above, TX20 transmits a second power to RX30 (step S8). The processes performed from step S8 to step S14 are the same as those shown in Figure 6 or Figure 7.

[0068] As described above, the authentication unit 234 (first authentication unit) authenticates RX30 (power receiving device) by using the device ID (first information) received from RX30. The authentication unit 131 (second authentication unit) authenticates RX30 by using the device ID and password (second information) received from RX30 via TX20. After the power supply unit 233 transmits the first power to RX30, RX30 transmits a beacon signal including the device ID. TX20 obtains the device ID by receiving the beacon signal. After the power supply unit 233 transmits the second power to RX30, RX30 transmits the device ID and password. TX20 receives the device ID and password and transmits the received device ID and password to the power supply control server 10.

[0069] The RX30 can transmit the information required for the first authentication to the TX20 by using the first power supply. The RX30 can transmit the information required for the second authentication to the TX20 by using the second power supply.

[0070] (Second embodiment) A second embodiment of the present invention will now be described. In the second embodiment, TX20 monitors the beacon signal transmitted from RX30. If no beacon signal is received from RX30 which should be in the power supply area, it is possible that RX30 is not activated. Therefore, TX20 transmits a first power to activate RX30.

[0071] The processing flow of the power supply system 1 will be explained using Figure 10. Figure 10 shows the processing flow of the power supply system 1. The processing shown in Figure 6 is changed to the processing shown in Figure 10. After the processing shown in Figure 10 is executed, the processing shown in Figure 7 is executed. The explanation of the same processing as shown in Figure 6 is omitted.

[0072] (Step S30) If RX30 is running, RX30 transmits beacon signals at predetermined time intervals. The detection unit 231 of TX20 monitors the beacon signals for a predetermined time and determines whether or not a beacon signal has been received. Figure 10 shows one RX30 that is not running, but other RX30s not shown may be running and transmit beacon signals. If the communication unit 21 receives a beacon signal within the predetermined time, the acquisition unit 230 acquires the beacon signal via the communication unit 21. The acquisition unit 230 outputs the acquired beacon signal to the detection unit 231. The detection unit 231 extracts the device ID contained in the beacon signal.

[0073] (Step S31) After a predetermined time has elapsed, the communication control unit 232 generates a status check request to request a status check of RX30 and outputs the status check request to the communication unit 21. The status check request includes all device IDs received within the predetermined time.

[0074] Since an active RX30 transmits beacon signals at predetermined time intervals, the communication unit 21 receives beacon signals from the RX30 within the predetermined time period during which the detection unit 231 monitors the beacon signals. On the other hand, since an inactive RX30 does not transmit beacon signals, the communication unit 21 does not receive beacon signals from the RX30 within the predetermined time period during which the detection unit 231 monitors the beacon signals. The device ID included in the beacon signal received within the predetermined time period is the device ID of the active RX30. The status check request includes the device ID of the active RX30.

[0075] (Step S32) The communication unit 11 of the power supply control server 10 receives a status confirmation request transmitted from TX20. The acquisition unit 130 acquires the device ID included in the status confirmation request via the communication unit 11. The power supply control unit 132 compares the device ID received from TX20 with the device ID included in the registration information 120 of the storage unit 12. If there is a device ID in the registration information 120 that does not match the device ID received from TX20, it means that the beacon signal containing that device ID was not received within a predetermined time. In other words, the RX30 with that device ID is not running, and it is possible that the battery 34 of that RX30 has a charge of 0. Therefore, the power supply control unit 132 determines that there is an RX30 with a battery charge of 0. If all the device IDs included in the registration information 120 match the device IDs received from TX20, the power supply control unit 132 determines that there is no RX30 with a battery charge of 0.

[0076] (Step S33) The power supply control unit 132 outputs a status check result to the communication unit 11, indicating the result of checking the status of RX30. The status check result indicates whether or not there is an RX30 with a battery charge of 0. The communication unit 11 transmits the authentication result to TX20.

[0077] (Step S34) The communication unit 21 of TX20 receives the status check result transmitted from the power supply control server 10. The acquisition unit 230 acquires the status check result via the communication unit 21. The acquisition unit 230 outputs the acquired status check result to the detection unit 231. If the status check result indicates that there are no RX30s with a battery charge of 0, the detection unit 231 determines that there are no RX30s with a battery charge of 0, and the process shown in Figure 10 ends. If the status check result indicates that there are RX30s with a battery charge of 0, the detection unit 231 determines that there are RX30s with a battery charge of 0.

[0078] If there is an RX30 with a battery charge of 0, as described above, TX20 sends the first power to RX30 (step S1). The processes performed in steps S1 to S8 are the same as those shown in Figure 6.

[0079] In the operation shown in Figure 9, the processes in steps S30 to S34 shown in Figure 10 may be executed. In other words, even when TX20a performs the first authentication, the processes in steps S30 to S34 shown in Figure 10 may be executed.

[0080] As described above, RX30 transmits a beacon signal containing a device ID (identification information) that identifies RX30 at predetermined time intervals. TX20 transmits the device IDs contained in the beacon signals received within the predetermined time to the power supply control server 10. If the power supply control server 10 finds that there are device IDs stored in the storage unit 12 that were not received from TX20, it transmits status information (status check result) to TX20 indicating that there are RX30s that are not running. When status information is received from the power supply control server 10, the power supply unit 233 transmits the first power to RX30.

[0081] If there are any RX30s that are not powered on, the TX20 sends a first power supply to power them on. If all RX30s are powered on, the TX20 does not need to send a first power supply, thus reducing wasted power.

[0082] (Modified version of the second embodiment) A modified example of the second embodiment of the present invention will now be described. In the modified example of the second embodiment, TX20 receives the device ID of RX30 present in the power supply area from the power supply control server 10. TX20 uses the device ID included in the beacon signal received from RX30 and the device ID received from the power supply control server 10 to determine whether or not there is an RX30 with a battery charge of 0.

[0083] The processing flow of the power supply system 1 will be explained using Figure 11. Figure 11 shows the processing flow of the power supply system 1. The processing shown in Figure 6 is changed to the processing shown in Figure 11. After the processing shown in Figure 11 is executed, the processing shown in Figure 7 is executed. The explanation of the same processing as shown in Figure 6 is omitted.

[0084] (Step S40) The communication control unit 232 of TX20 generates a device ID request to request a device ID from the power supply control server 10 and outputs the device ID request to the communication unit 21. The communication unit 21 transmits the device ID request to the power supply control server 10.

[0085] (Step S41) The communication unit 11 of the power supply control server 10 receives a device ID request sent from TX20. The acquisition unit 130 acquires the device ID request via the communication unit 11. The acquisition unit 130 acquires all device IDs included in the registration information 120 of the storage unit 12 from the storage unit 12 and outputs the device IDs to the communication unit 11. The communication unit 11 transmits the device IDs to TX20.

[0086] (Step S42) The communication unit 21 of TX20 receives the device ID transmitted from the power supply control server 10. The acquisition unit 230 acquires the device ID via the communication unit 21. The acquisition unit 230 outputs the acquired device ID to the detection unit 231. If RX30 is running, RX30 transmits a beacon signal at predetermined time intervals. The detection unit 231 monitors the beacon signal for a predetermined time and determines whether or not a beacon signal has been received. Figure 11 shows one RX30 that is not running, but RX30 not shown may be running and transmit a beacon signal. If the communication unit 21 receives a beacon signal within the predetermined time, the acquisition unit 230 acquires the beacon signal via the communication unit 21. The acquisition unit 230 outputs the acquired beacon signal to the detection unit 231. The detection unit 231 checks the device ID included in the beacon signal.

[0087] (Step S43) After a predetermined time has elapsed, the detection unit 231 compares the device ID received from the power supply control server 10 with the device ID included in the beacon signal. If there is a device ID among the device IDs received from the power supply control server 10 that does not match the device ID included in the beacon signal, then the beacon signal containing that device ID was not received within the predetermined time. In other words, the RX30 with that device ID is not running, and it is possible that the battery 34 of that RX30 has a charge of 0. Therefore, the detection unit 231 determines that there is an RX30 with a charge of 0. If all the device IDs received from the power supply control server 10 match the device IDs included in the beacon signal, then the detection unit 231 determines that there is no RX30 with a charge of 0.

[0088] If there is an RX30 with a battery charge of 0, as described above, TX20 sends the first power to RX30 (step S1). The processes performed in steps S1 to S8 are the same as those shown in Figure 6.

[0089] In the operation shown in Figure 9, the processes from steps S40 to S43 shown in Figure 11 may be executed. In other words, even when TX20a performs the first authentication, the processes from steps S40 to S43 shown in Figure 11 may be executed.

[0090] As described above, RX30 transmits a beacon signal containing a device ID (identification information) that identifies RX30 at predetermined time intervals. Power supply control server 10 has a storage unit 12 that stores the device ID and transmits the device ID stored in the storage unit 12 to TX20. If a beacon signal containing the device ID received from power supply control server 10 is not received within the predetermined time, power supply unit 233 transmits first power to RX30.

[0091] If there are any RX30s that are not powered on, the TX20 sends a first power supply to power them on. If all RX30s are powered on, the TX20 does not need to send a first power supply, thus reducing wasted power.

[0092] While embodiments of the present invention have been described in detail above with reference to the drawings, the specific configuration is not limited to the embodiments described above, and may include design changes and the like that do not depart from the spirit of the present invention. [Explanation of Symbols]

[0093] 1 Power supply system, 10 Power supply control server, 11, 21, 31 Communication unit, 12, 22, 32 Storage unit, 13, 23, 23a, 33 Control unit, 20, 20a TX, 30 RX, 34 Battery, 130, 230, 330 Acquisition unit, 131, 234 Authentication unit, 132 Power supply control unit, 231 Detection unit, 232, 331 Communication control unit, 233 Power supply unit, 332 Power receiving unit

Claims

1. A power transmission unit that transmits a first power, a second power greater than the first power, and a third power greater than the first power to a power receiving device, After the power transmission unit transmits the first power to the power receiving device, a first authentication unit authenticates the power receiving device, After the power transmission unit transmits the second power to the power receiving device, a second authentication unit authenticates the power receiving device, Equipped with, After the first authentication unit authenticates the power receiving device, the power transmission unit transmits the second power to the power receiving device. After the second authentication unit authenticates the power receiving device, the power transmission unit transmits the third power to the power receiving device. Power supply system.

2. Before the power transmission unit transmits the first power to the power receiving device, the power receiving device is not activated. After the power transmission unit transmits the first power to the power receiving device, the power receiving device starts up. After the power receiving device is started up, the first authentication unit authenticates the power receiving device. The power supply system according to claim 1.

3. A power transmission device having the aforementioned power transmission unit, A power supply control server having the first authentication unit and the second authentication unit, Equipped with, The first authentication unit authenticates the power receiving device by using the first information received from the power receiving device via the power transmission device. The second authentication unit authenticates the power receiving device by using the second information received from the power receiving device via the power transmission device. The power supply system according to claim 1 or claim 2.

4. After the power transmission unit transmits the first power to the power receiving device, the power receiving device transmits a beacon signal containing the first information. The power transmission device acquires the first information by receiving the beacon signal, and transmits the acquired first information to the power supply control server. After the power transmission unit transmits the second power to the power receiving device, the power receiving device transmits the second information. The power transmission device receives the second information and transmits the received second information to the power supply control server. The power supply system according to claim 3.

5. The power receiving device transmits the beacon signal, which includes identification information for identifying the power receiving device, at predetermined time intervals. The power transmission device transmits the identification information contained in the beacon signal received within the predetermined time to the power supply control server. The power supply control server has a storage unit for storing the identification information, and if there is any identification information stored in the storage unit that was not received from the power transmission device, it transmits status information to the power transmission device indicating that there is a power receiving device that is not started up. When the status information is received from the power supply control server, the power transmission unit transmits the first power to the power receiving device. The power supply system according to claim 4.

6. The power receiving device transmits the beacon signal, which includes identification information for identifying the power receiving device, at predetermined time intervals. The power supply control server has a storage unit for storing the identification information, and transmits the identification information stored in the storage unit to the power transmission device. If the beacon signal containing the identification information received from the power supply control server is not received within the predetermined time, the power transmission unit transmits the first power to the power receiving device. The power supply system according to claim 4.

7. A power transmission device having the power transmission unit and the first authentication unit, A power supply control server having the second authentication unit, Equipped with, The first authentication unit authenticates the power receiving device by using the first information received from the power receiving device. The second authentication unit authenticates the power receiving device by using the second information received from the power receiving device via the power transmission device. The power supply system according to claim 1 or claim 2.

8. After the power transmission unit transmits the first power to the power receiving device, the power receiving device transmits a beacon signal containing the first information. The power transmission device acquires the first information by receiving the beacon signal. After the power transmission unit transmits the second power to the power receiving device, the power receiving device transmits the second information. The power transmission device receives the second information and transmits the received second information to the power supply control server. The power supply system according to claim 7.

9. The power receiving device transmits the beacon signal, which includes identification information for identifying the power receiving device, at predetermined time intervals. The power transmission device transmits the identification information contained in the beacon signal received within the predetermined time to the power supply control server. The power supply control server has a storage unit for storing the identification information, and if there is any identification information stored in the storage unit that was not received from the power transmission device, it transmits status information to the power transmission device indicating that there is a power receiving device that is not started up. When the status information is received from the power supply control server, the power transmission unit transmits the first power to the power receiving device. The power supply system according to claim 8.

10. The power receiving device transmits the beacon signal, which includes identification information for identifying the power receiving device, at predetermined time intervals. The power supply control server has a storage unit for storing the identification information, and transmits the identification information stored in the storage unit to the power transmission device. If the beacon signal containing the identification information received from the power supply control server is not received within the predetermined time, the power transmission unit transmits the first power to the power receiving device. The power supply system according to claim 8.

11. The steps include: the power transmission unit transmitting the first power to the power receiving device, The steps include: after the power transmission unit transmits the first power to the power receiving device, the first authentication unit authenticates the power receiving device; The first authentication unit authenticates the power receiving device, and the power transmission unit transmits a second power greater than the first power to the power receiving device. The steps include: after the power transmission unit transmits the second power to the power receiving device, the second authentication unit authenticates the power receiving device; The steps include: after the second authentication unit authenticates the power receiving device, the power transmission unit transmits a third power greater than the first power to the power receiving device; A power supply method comprising the following features.

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