Power transmission system, base station device, power receiver and power transmitter

Abstract

To provide a power transmission system and the like suppressing interference between a radio wave for feeding and a radio wave for communication.SOLUTION: A power transmission system comprises a power receiver, a base station device, and a power transmitter. The power receiver includes: a power receiving part capable of receiving a radio wave for feeding transmitted from the power transmitter; and a power receiver control part transmitting a power transmission start request to the base station device and controlling the transmission of a power transmission stop request to the power transmitter. The base station device includes a base station control part controlling the transmission of a power transmission start instruction to the power transmitter when receiving the power transmission start request from the power receiver. The power transmitter in cooperation with the base station device includes: a power transmitting part transmitting the radio wave for feeding to a fixed range; and a power transmitter control part starting the power transmitter to transmit power to the power receiver when receiving the power transmission start instruction from the base station device, and stopping the power transmitter to stop the power transmission to the power receiver when receiving the power transmission stop request from the power receiver.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a power transmission system, a base station device, a power receiver, and a power transmitter. [Background technology]

[0002] Patent Document 1 discloses a wireless power feeding method for wirelessly transmitting power to a power receiver using microwaves. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2018-98770 Summary of the Invention [Problem to be solved by the invention]

[0004] When a communication terminal with a power receiving function receives radio waves (for example, microwaves) for power supply transmitted by a power transmitter, a problem occurs in which the microwaves for power supply interfere with radio waves for communication used by the communication terminal for network communication. The technology of Patent Document 1 does not take into consideration radio waves for communication and does not solve this problem.

[0005] In one aspect, an object of the present disclosure is to provide a power transmission system or the like that suppresses interference between radio waves for power supply and radio waves for communication. [Means for solving the problem]

[0006] A power transmission system according to one embodiment of the present invention is a power transmission system comprising a power receiver, a base station device, and a power transmitter, wherein the power receiver includes a power receiving unit capable of receiving power supply radio waves transmitted from the power transmitter, and a power receiver control unit that controls the transmission of a power transmission start request to the base station device and the transmission of a power transmission stop request to the power transmitter, the base station device includes a base station control unit that controls the transmission of a power transmission start instruction to the power transmitter when the power transmission start request is received from the power receiver, and the power transmitter that cooperates with the base station device includes a power transmitting unit that transmits the power supply radio waves within a certain range, and a power transmitter control unit that causes the power transmitting unit to start transmitting power to the power receiver when the power transmission start instruction is received from the base station device, and causes the power transmitting unit to stop transmitting power to the power receiver when the power transmission stop request is received from the power receiver. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 illustrates an example of a system. [Figure 2] FIG. 10 is a diagram illustrating another example of a system. [Figure 3] FIG. 2 is a block diagram illustrating an example of a terminal, a base station device, and a power transmitter. [Figure 4] 10 is a flowchart illustrating an example of a flow of processing executed by a power transmitter. [Figure 5] 10 is a flowchart illustrating an example of a flow of processing executed by a base station device. [Figure 6A] FIG. 10 is a diagram illustrating an example of control of power transmission timing. [Figure 6B] FIG. 10 is a diagram illustrating another example of control of power transmission timing. [Figure 7] 10 is a flowchart illustrating an example of a flow of processing executed by a terminal. [Figure 8] FIG. 10 is a diagram illustrating an example of a system according to a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0008] Each embodiment will be described below. The following embodiments can be modified as appropriate. The configurations of the embodiments can be replaced with substantially similar configurations, configurations that achieve similar effects, or configurations that can achieve similar purposes. Furthermore, the order of the processes in the flowcharts described in the embodiments can be changed as much as possible.

[0009] FIG. 1 is a diagram illustrating an example of a system 10 according to the present embodiment. The system 10 includes a terminal 20, a base station device 30, and a power transmitter 40. The terminal 20 is a device such as a smartphone, a mobile phone, a tablet terminal, a personal computer, a wearable device, or an IoT (Internet of Things) device. The terminal 20 has a communication function. The terminal 20 corresponds to a power receiver. In the following description, the terminal 20 is exemplarily described as a smartphone serving as a UE. The terminal 20 also corresponds to a UE (User Equipment).

[0010] The terminal 20 has a function of receiving power-supply radio waves (microwaves) transmitted by the power transmitter 40 and charging a battery built into the terminal 20. The terminal 20 can also communicate (network communication) with the base station device 30. In this embodiment, the base station device 30 constructs a local 5G (Local 5th Generation Mobile Communication System) network, and the terminal 20 can perform local 5G network communication with the base station device 30.

[0011] The base station device 30 may be a base station device operated by a telecommunications carrier. The base station device 30 may also build a network that complies with a standard other than the 5G standard (for example, a standard such as 4th Generation Mobile Communication System (4G) or Long Term Evolution (LTE)). The base station device 30 may be an access point that complies with the Wi-Fi standard. The base station device 30 may also be a base station device for an LPWA (Low Power Wide Area) or an LPWAN (Low Power Wide Area Network), etc.

[0012] The power transmitter 40 is a device that transmits power wirelessly within a certain range. In this embodiment, the power transmitter 40 transmits microwaves within a certain range as radio waves for power supply. Radio waves other than microwaves may also be used as the radio waves for power supply.

[0013] In the example of Fig. 1, the power transmitter 40 transmits microwaves to the terminal 20 located within a space R, such as a room, as the above-mentioned certain range. The power transmitter 40 may transmit power to the terminal 20 located within a certain range in an open space.

[0014] The base station device 30 and the power transmitter 40 are connected and operate in cooperation with each other. Although the example in Fig. 1 shows an example in which there is one power transmitter 40, the system 10 may include multiple power transmitters 40. For example, multiple power transmitters 40 may be installed within a predetermined area in which a local 5G network is constructed, and the base station device 30 may control each power transmitter 40.

[0015] 1, a terminal 20 and a base station device 30 perform network communication using radio waves RW for communication. A power transmitter 40 transmits microwaves MW to the terminal 20. The microwaves MW may interfere with the radio waves RW for communication. For example, when the frequency band used by the microwaves MW partially overlaps with the frequency band of the radio waves RW for communication, the microwaves MW may interfere with the radio waves RW for communication.

[0016] Next, interference between microwaves MW and radio waves RW for communication will be described. Fig. 2 is a diagram showing another example of the system 10. In the example of Fig. 2, terminal 20A is a terminal that has the function of receiving microwaves MW from power transmitter 40. Terminal 20A is also referred to as a WPT (Wireless Power Transfer) compatible terminal. Terminal 20B is a terminal that does not have the function of receiving power transmitted from power transmitter 40. Terminal 20B is sometimes referred to as a WPT incompatible terminal.

[0017] Assume that terminal 20B is present in space R, but terminal 20A is not. Since terminal 20B is present in space R, it is located within the range of microwaves MW from power transmitter 40. When terminal 20B performs network communication with base station device 30, terminal 20B may not be able to communicate normally with base station device 30 due to interference between microwaves MW and radio waves RW used for communication.

[0018] Furthermore, the terminal 20B is a terminal that does not have the function of receiving microwaves MW from the power transmitter 40. Therefore, the power transmitter 40 transmits microwaves MW to the terminal 20B, which is a WPT-incompatible terminal, and therefore unnecessary power consumption occurs in the power transmitter 40.

[0019] The same problem as above may occur in the terminal 20A. For example, if the terminal 20A has a remaining battery capacity (such as being fully charged), power transmission from the power transmitter 40 to the terminal 20A is unnecessary. In such a case, if the power transmitter 40 transmits microwaves MW, problems such as the above-mentioned interference problem and unnecessary power consumption by the power transmitter 40 may occur. In this embodiment, the above-mentioned problems are solved.

[0020] 3 is a block diagram showing an example of a terminal 20, a base station device 30, and a power transmitter 40. The terminal 20 has a terminal control unit 21, a power receiving unit 22, a terminal first communication unit 23, and a terminal second communication unit 24. The terminal 20 may have other configurations.

[0021] The terminal control unit 21 performs overall control of the terminal 20. The terminal control unit 21 has a processor and a memory. The processor executes a plurality of instruction sets stored in the memory to realize various controls of this embodiment. The processor may be a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), or the like. The processor and memory may be realized by a circuit such as an FPGA (Field Programmable Gate Array), for example.

[0022] The power receiving unit 22 receives the microwaves MW transmitted by the power transmitter 40. The power receiving unit 22 converts the received microwaves MW into electric power and charges a battery of the terminal 20. The terminal 20A, which is the WPT-compatible terminal described above, has the power receiving unit 22. On the other hand, the terminal 20B, which is a WPT-incompatible terminal, does not have the power receiving unit 22.

[0023] The terminal first communication unit 23 performs communication to exchange various information with the power transmitter first communication unit 43 of the power transmitter 40. For example, short-range wireless communication by Bluetooth (registered trademark) may be performed between the power transmitter first communication unit 43 of the power transmitter 40 and the terminal first communication unit 23 of the terminal 20.

[0024] BLE (Bluetooth Low Energy: registered trademark) may be used as the short-range wireless communication. In the present embodiment, for example, the power transmitter first communication unit 43 of the power transmitter 40 transmits a beacon signal using the advertising function of BLE. The terminal first communication unit 23 of the terminal 20 responds to the beacon signal, so that the power transmitter 40 can detect the presence of the terminal 20 that supports WPT. Any method other than the beacon signal that can detect the presence of the terminal 20 may be used.

[0025] The terminal second communication unit 24 performs network communication with the base station first communication unit 32 of the base station device 30. In the present embodiment, for example, network communication using local 5G is performed between the terminal second communication unit 24 and the base station first communication unit 32.

[0026] The base station device 30 includes a base station control unit 31, a base station first communication unit 32, and a base station second communication unit 33. The base station device 30 may have other configurations.

[0027] The base station device 30 is a device used when the terminal 20 performs local 5G network communication. The base station device 30 operates in cooperation with the power transmitter 40. A plurality of terminals 20 are used in the system 10. Each terminal 20 can use any network (for example, the Internet) by using the local 5G network communication by the base station device 30. Note that the present embodiment can also be applied to a case where only one terminal 20 is used in the system 10.

[0028] The base station device 30 may have, for example, a core network function. Alternatively, a separate device having a core network function may be connected to the base station device 30. The terminal 20 can perform network communication by performing various procedures including an attach process between the terminal 20 and the base station device 30.

[0029] The base station control unit 31 performs overall control of the base station device 30. Some of the functions of the base station control unit 31 may be realized by cooperation between the base station device 30 and devices other than the base station device 30. The base station device 30 has a processor and a memory. The various controls of this embodiment can be realized by the processor executing multiple instruction sets stored in the memory.

[0030] The base station first communication unit 32 performs network communication with the terminal second communication unit 24. The base station first communication unit 32 performs network communication with a plurality of terminals 20. The base station device 30 manages and controls each terminal 20.

[0031] The base station second communication unit 33 communicates with the power transmitter second communication unit 44 of the power transmitter 40. This allows the base station device 30 and the power transmitter 40 to operate in cooperation with each other. The system 10 of this embodiment illustratively includes a plurality of power transmitters 40. The base station device 30 manages and controls each power transmitter 40. The base station device 30 and the power transmitter 40 are connected by wire. However, they may also be connected wirelessly.

[0032] The power transmitter 40 has a power transmitter control unit 41, a power transmitter unit 42, a power transmitter first communication unit 43, and a power transmitter second communication unit 44. The power transmitter 40 may have other configurations. The power transmitter control unit 41 performs overall control of the power transmitter 40. The power transmitter control unit 41 has a processor and a memory. The various controls of this embodiment can be realized by the processor executing a plurality of instruction sets stored in the memory.

[0033] The power transmitter 42 transmits microwaves MW within a certain range in the space R. The power transmitter first communication unit 43 performs short-range wireless communication with the terminal first communication unit 23. The power transmitter second communication unit 44 performs communication with the base station second communication unit 33 so that the base station device 30 and the power transmitter 40 can operate in cooperation with each other.

[0034] The terminal 20, the base station device 30, and the power transmitter 40 operate in cooperation with each other. The flow of processing by each device will be described below. FIG. 4 is a flowchart showing an example of the flow of processing executed by the power transmitter 40.

[0035] The power transmitter control unit 41 controls the power transmitter 40 to maintain the sleep state (step S101). The sleep state is a state in which the power transmitter 42 does not transmit microwaves MW and does not transmit a beacon signal. For example, the sleep state may be a power saving state in which the power transmitter control unit 41 and the power transmitter second communication unit 44 are functioning, but the power transmitter 42 and the power transmitter first communication unit 43 are not functioning.

[0036] The power transmitter control unit 41 determines whether a WakeUp signal has been received from the base station device 30 (step S102). The WakeUp signal is a signal that the base station device 30 uses to put the power transmitter 40 into a state where it can transmit power, and is transmitted from the base station second communication unit 33 to the power transmitter second communication unit 44.

[0037] If the power transmitter 40 has not received the WakeUp signal from the base station device 30, the power transmitter control unit 41 determines No in step S102 and returns the process to step S101. In this case, the power transmitter 40 maintains the sleep state.

[0038] The power transmitter 40 maintains the sleep state until it receives a WakeUp signal. As will be described later, the WakeUp signal is a signal transmitted from the base station device 30 to the power transmitter 40 in response to the base station device 30 receiving a power transmission start request from the terminal 20A (WPT compatible terminal) that can receive and charge the microwaves MW transmitted by the power transmitter 40. The power transmission start request is a signal from the terminal 20A, which is a WPT compatible terminal, requesting the transmission of microwaves MW from the power transmitter 40.

[0039] The terminal 20B (non-WPT compatible terminal) that cannot be charged by receiving microwaves MW from the power transmitter 40 does not transmit a power transmission start request. Therefore, even if the terminal 20B enters the space R, which is a certain range within which the power transmitter 40 can transmit microwaves MW, the power transmission start request is not transmitted to the base station device 30.

[0040] That is, even if the terminal 20B, which is a WPT-incompatible terminal, enters the space R, the power transmitter 40 will not transmit the microwaves MW. Therefore, when the terminal 20B in the space R performs network communication with the base station device 30, interference by the microwaves MW will not occur. Furthermore, since the power transmitter 40 does not transmit unnecessary microwaves MW, power saving of the power transmitter 40 is achieved.

[0041] Even if the terminal 20A, which is a WPT-compatible terminal, enters the space R, if the remaining battery charge of the terminal 20A is equal to or greater than a certain amount, the terminal 20A does not transmit a power transmission start request. In this case, similar to the above, the WakeUp signal is not transmitted from the base station device 30 to the power transmitter 40.

[0042] Therefore, the power transmitter 40 sleep The state is maintained. Even if the terminal 20A, which is a WPT-compatible terminal, enters the space R, if the terminal 20A does not need to receive power, the power transmitter 40 does not transmit the microwaves MW. Therefore, when the terminal 20A performs network communication with the base station device 30, interference by the microwaves MW does not occur. Furthermore, since unnecessary microwaves MW are not transmitted from the power transmitter 40, power saving of the power transmitter 40 is achieved.

[0043] On the other hand, the terminal 20A transmits a power transmission start request to the base station device 30, for example, when the remaining battery power falls below a certain level. In response to receiving the power transmission start request, the base station device 30 transmits a WakeUp signal to the power transmitter 40. In this case, the power transmitter 40 receives the WakeUp signal. Hereinafter, unless otherwise specified, the terminal 20 is assumed to be the terminal 20A (WPT compatible terminal).

[0044] When the power transmitter control unit 41 receives the WakeUp signal, it determines Yes in step S102 and starts up the power transmitter 40. Then, the power transmitter control unit 41 advances the process to step S103. The power transmitter control unit 41 causes the power transmitter first communication unit 43 to transmit a beacon signal (step S102).

[0045] If there is a terminal 20 within the space R, the terminal 20 that receives the beacon signal transmits a signal (response signal) in response to the beacon signal to the power transmitter 40. When the power transmitter first communication unit 43 receives the response signal, the terminal control unit 21 can detect that the terminal 20 is present within the space R. If there are multiple terminals 20 within the space R, the terminal control unit 21 can detect the presence of each terminal 20 based on the response signal from each terminal 20.

[0046] The power transmitter control unit 41 can recognize the position of the terminal 20 in the space R based on the signal strength of the response signal received by the power transmitter first communication unit 43. When the signal strength of the response signal from the terminal 20 is strong, the power transmitter control unit 41 recognizes that the terminal 20 is located near the power transmitter 40. When the signal strength of the response signal from the terminal 20 is weak, the power transmitter control unit 41 recognizes that the terminal 20 is located far from the power transmitter 40.

[0047] The power transmitter control unit 41 determines whether a response signal has been received from the terminal 20 (step S104). If there is no terminal 20 in the space R, the power transmitter first communication unit 43 does not receive the response signal. In this case, the power transmitter control unit 41 determines No in step S104 and returns the process to step S103. Then, the power transmitter 40 continues to transmit the beacon signal.

[0048] When the power transmitter first communication unit 43 receives a response signal from the terminal 20, the power transmitter control unit 41 determines Yes in step S104 and proceeds to step S105. The power transmitter control unit 41 adjusts the power transmission conditions (step S105).

[0049] For example, as a power transmission condition, the power transmitter control unit 41 adjusts the phase of the microwaves MW transmitted by the power transmitter 40 so that the power receiving unit 22 of the terminal 20 can receive the microwaves MW at the highest intensity. Furthermore, as a power transmission condition, the power transmitter control unit 41 may change the intensity of the microwaves MW transmitted by the power transmitting unit 42 depending on the position of the terminal 20 from the power transmitter 40.

[0050] For example, if the terminal 20 is located far from the power transmitter 40 based on the response signal, the power transmitter control unit 41 increases the intensity of the microwaves MW transmitted by the power transmitter 42. On the other hand, if the terminal 20 is located close to the power transmitter 40, the power transmitter control unit 41 may reduce the intensity of the microwaves MW transmitted by the power transmitter 42. This makes it possible to transmit microwaves MW of an appropriate intensity depending on the distance from the power transmitter 42 to the terminal 20.

[0051] The power transmitter control unit 41 controls the power transmitting unit 42 to transmit the microwaves MW (step S106). As a result, the power receiving unit 22 of the terminal 20 receives the microwaves MW, and wireless power transmission from the power transmitter 40 to the terminal 20 is performed.

[0052] The power transmitter control unit 41 determines whether communication with the terminal 20 has been disconnected (step S107). For example, the power transmitter control unit 41 determines that communication with the terminal 20 has been disconnected when a response signal from the terminal 20 is no longer received, or when the strength of the response signal has weakened to the extent that the power receiving unit 22 cannot normally receive the microwaves MW. In this case, the power transmitter control unit 41 determines Yes in step S107 and proceeds to step S109.

[0053] If the communication with the terminal 20 is not disconnected, the power transmitter control unit 41 determines No in step S107 and proceeds to step S108. The power transmitter control unit 41 determines whether the power transmitter first communication unit 43 has received a power transmission stop request from the terminal 20 (step S108).

[0054] The power transmission stop request is a request from the terminal 20 to the power transmitter 40 to stop transmitting microwaves MW, and is transmitted from the terminal first communication unit 23 of the terminal 20 to the power transmitter first communication unit 43 of the power transmitter 40. The battery of the terminal 20 is charged when the terminal 20 receives the microwaves MW transmitted by the power transmitter 40. When the remaining battery charge of the terminal 20 reaches or exceeds a certain level, the terminal 20 transmits the power transmission stop request to the power transmitter 40.

[0055] If the power transmitter first communication unit 43 has not received a power transmission stop request from the terminal 20, the power transmitter control unit 41 determines No in step S108 and returns the process to step S105. As a result, the adjustment of the power transmission conditions in step S105 is performed again.

[0056] Since the position of the terminal 20 in the space R may change, the power transmission conditions are repeatedly adjusted, so that power can be transmitted to the terminal 20 under optimal power transmission conditions. However, the power transmission conditions do not have to be repeatedly adjusted. In this case, the power transmitter control unit 41 may return the process to step S106 after determining No in step S108.

[0057] When the power transmitter first communication unit 43 receives a power transmission stop request from the terminal 20, the power transmitter control unit 41 determines "Yes" in step S108 and proceeds to step S109. The power transmitter control unit 41 stops the transmission of microwaves MW from the power transmitting unit 42 (step S109). This stops power transmission from the power transmitter 40. Step S109 is also executed when the determination in step S107 is "Yes."

[0058] When there are a plurality of terminals 20A (WPT compatible terminals) in the space R, the power transmitter control unit 41 performs the processes of steps S105 to S109 for each terminal 20A individually.

[0059] The power transmitter control unit 41 determines whether the transmission of microwave MW to all terminals 20 in the space R has been completed (step S110). When there are multiple terminals 20 in the space R, even if the transmission of microwave MW to one terminal 20 has stopped, the transmission of microwave MW to other terminals 20 may not have been completed. In this case, the power transmitter control unit 41 determines No in step S110 and returns the process to step S105.

[0060] When the transmission of microwaves MW to all terminals 20 in the space R is completed, the power transmitter control unit 41 determines Yes in step S110 and proceeds to step S111. The power transmitter control unit 41 stops the transmission of the beacon signal from the power transmitter first communication unit 43 (step S111).

[0061] This is because, when the transmission of microwaves MW to all terminals 20 in space R has ended, not only the transmission of microwaves MW but also the transmission of beacon signals becomes unnecessary. By executing step S111, the transmission of unnecessary beacon signals is also stopped, and the power saving effect of the power transmitter 40 becomes even greater.

[0062] The power transmitter control unit 41 causes the power transmitter 40 to transition to a sleep state (step S112). The power transmitter control unit 41 controls the power transmitter second communication unit 44 to transmit a sleep state transition notification to the base station device 30 (step S113).

[0063] The sleep state transition notification is a notification indicating that the power transmitter 40 has transitioned to a sleep state. By receiving the sleep state transition notification, the base station device 30 sleep After executing step S113, the power transmitter control unit 41 ends the flowchart in FIG.

[0064] Next, a description will be given of the processing flow of the base station device 30. Fig. 5 is a flowchart showing an example of the processing flow executed by the base station device 30. The base station control unit 31 of the base station device 30 determines whether a connection request has been received from the terminal 20 (step S201). The system 10 includes a plurality of terminals 20, and each terminal 20 is connectable to the base station device 30.

[0065] If the base station control unit 31 has not received a connection request from any of the terminals 20, the base station control unit 31 determines No in step S201 and returns the process to step S201. In this case, the base station control unit 31 waits until the base station device 30 receives a connection request from the terminal 20.

[0066] On the other hand, if the base station device 30 receives a connection request from any of the terminals 20, the base station control unit 31 determines Yes in step S201 and proceeds to step S202. The base station control unit 31 performs a process of connecting the terminal 20 that sent the connection request to the network (step S202).

[0067] The process of connecting to a network includes, for example, an attach process, which is one of the procedures performed when the terminal 20 connects to a network via the base station device 30, and is a process of registering the terminal 20 in the network.

[0068] During the attach process, UE capability is transmitted and received between the base station device 30 and the terminal 20. The UE capability includes, for example, information indicating functions supported by the terminal 20 (UE), and is information included in a notification transmitted from the terminal 20 to the base station device 30 in response to an inquiry from the base station device 30 to the terminal 20. For example, the UE capability may be included in a UE Registration Request that is first transmitted from the terminal 20 (UE) to the base station device 30.

[0069] The information on UE capability may include information (power reception compatibility information) indicating whether or not the UE is capable of receiving power transmitted from the power transmitter 40. The power reception compatibility information is, for example, information indicating whether or not the terminal is WPT compatible.

[0070] The base station control unit 31 determines whether the terminal 20 that has transmitted the connection request is a terminal that can receive power transmitted from the power transmitter 40 (step S203). The base station control unit 31 may make the determination in step S203 based on the power reception capability information included in the above-mentioned UE capability information.

[0071] The base station control unit 31 may make the determination in step S203 based on information other than the UE capability. For example, the base station control unit 31 may make the determination in step S203 based on information transmitted and received after a connection between the terminal 20 and the network is established.

[0072] If the terminal 20 that sent the connection request is the terminal 20B (WPT non-compatible terminal) that cannot receive microwaves MW from the power transmitter 40, the base station control unit 31 determines No in step S203. In this case, the base station control unit 31 controls network communication by the terminal 20 (terminal 20B) via the base station device 30 (step S204).

[0073] When the base station control unit 31 executes step S204, the base station control unit 31 does not perform control related to power reception of the terminal 20. After executing step S204, the base station control unit 31 ends the flowchart in FIG.

[0074] If the terminal 20 that has transmitted the connection request is the terminal 20A (WPT compatible terminal) that can receive power transmitted from the power transmitter 40, the base station control unit 31 determines Yes in step S203. In this case, the base station control unit 31 determines whether a power transmission start request has been received from the terminal 20 connected to the base station device 30 (step S205).

[0075] If the base station device 30 has not received the power transmission start request, the terminal 20 has not requested power transmission. Therefore, the base station control unit 31 controls network communication by the terminal 20 via the base station device 30 without performing control related to power transmission (step S206). Then, the base station control unit 31 returns the process to step S205 and waits until it receives a power transmission start request from the terminal 20 connected to the base station device 30.

[0076] When the base station device 30 receives the power transmission start request, the base station control unit 31 proceeds to step S207. The base station control unit 31 determines whether the power transmitter 40 is in a sleep state (step S207). Whether the power transmitter 40 is in a sleep state can be determined based on whether the base station device 30 has received the sleep state transition notification described above. For example, the base station control unit 31 manages the sleep state transition notification for each power transmitter 40.

[0077] If the power transmitter 40 is in a sleep state, the base station control unit 31 determines Yes in step S207 and proceeds to step S208. The base station control unit 31 controls the base station second communication unit 33 to transmit a WakeUp request to the power transmitter 40 (step S208). As a result, the WakeUp request is transmitted to the power transmitter 40, and the power transmitter 40 starts up in response to the WakeUp request. Then, the base station control unit 31 proceeds to step S209.

[0078] If the power transmitter 40 is not in a sleep state, there is no need to start up the power transmitter 40. In this case, the base station control unit 31 determines No in step S207 and advances the process to step S209.

[0079] The base station control unit 31 controls the power transmission timing of the power transmitter 40 (step S209). Fig. 6A is a diagram showing an example of the control of the power transmission timing. The base station control unit 31 controls the time period of network communication between the base station device 30 and the terminal 20 and the time period of power transmission from the power transmitter 40 to the terminal 20 in a time-division manner.

[0080] In the example of Fig. 6A, communication indicates a time period during which network communication is performed between the base station device 30 and the terminal 20, and power transmission indicates a time period during which the power transmitter 40 transmits microwaves MW to the terminal 20. As in the example of Fig. 6A, the time period for network communication and the time period for power transmission are switched in a time-division manner. This prevents interference between the radio waves RW for communication and the microwaves MW, even in a case where a terminal 20 (terminal 20A) capable of receiving power transmitted from the power transmitter 40 performs network communication and receives microwaves MW at the same time.

[0081] Fig. 6B is a diagram showing another example of control of power transmission timing. There are cases where the base station device 30 is connected to multiple power transmitters 40. In the example of Fig. 6B, power transmitters 40A, 40B, and 40C are connected to the base station device 30. In this case, the base station control unit 31 assigns power transmission time periods to each of the power transmitters 40 in turn.

[0082] The lengths of the time periods for communication and power transmission in Fig. 6A may be the same or different. The lengths of each time period may be set arbitrarily. In the example of Fig. 6B, the time periods for power transmission of each of the power transmitters 40A, 40B, and 40C may be unevenly allocated to specific power transmitters 40. For example, a longer time period for power transmission may be allocated to the power transmitter 40A, and a shorter time period for power transmission may be allocated to the power transmitters 40B and 40C.

[0083] As described above, the base station control unit 31 performs the process of step S209 in Fig. 5. If step S209 is not executed, all of the power transmission time periods in Fig. 6A and Fig. 6B are allocated to network communication.

[0084] After executing step S209, the base station control unit 31 proceeds to step S210. The base station control unit 31 controls network communication by the terminal 20 via the base station device 30 (step S210). The processing of step S210 corresponds to the control of network communication during the communication time periods in FIGS. 6A and 6B.

[0085] Then, the base station control unit 31 determines whether a sleep state transition notification has been received from the power transmitter 40 (step S211). If a sleep state transition notification has not been received from the power transmitter 40, the base station control unit 31 determines No in step S211 and returns the process to step S209. In this case, the processes of steps S209 and S210 are repeated until a sleep state transition notification is received.

[0086] When the base station device 30 receives the sleep state transition notification from the power transmitter 40, the base station control unit 31 determines "Yes" in step S211 and proceeds to step S212. sleep The base station device 30 stores sleep state transition information indicating that the base station device 30 has transitioned to the sleep state (step S212). The sleep state transition information is stored in the memory of the base station device 30, an auxiliary storage device, or the like, for example.

[0087] The base station control unit 31 may store the power transmitter 40 that has transmitted the sleep state transition notification in association with the sleep state transition completion information. This allows the sleep state of each of the multiple power transmitters 40 connected to the base station device 30 to be managed individually.

[0088] After executing the process of step S211, the base station control unit 31 ends the flowchart of Fig. 5. The process flow of the base station device 30 has been described above.

[0089] Next, a description will be given of the processing flow of the terminal 20. Fig. 7 is a flowchart showing an example of the processing flow executed by the terminal 20. The terminal control unit 21 of the terminal 20 determines whether the base station device 30 has been detected (step S301). For example, the terminal control unit 21 may make the determination of step S301 depending on whether the terminal second communication unit 24 has detected radio waves from the base station device 30.

[0090] If the terminal 20 has not detected the base station device 30, the terminal control unit 21 determines No in step S301 and returns the process to step S301. In this case, the terminal 20 waits until it detects the base station device 30. If the terminal 20 detects the base station device 30, the terminal control unit 21 advances the process to step S302.

[0091] The terminal control unit 21 transmits a connection request to the base station device 30 (step S302). This starts a process of connecting the terminal 20 to the network. This process includes, for example, the above-mentioned attach process. Furthermore, this attach process includes the above-mentioned UE capability information.

[0092] The terminal control unit 21 determines whether the terminal 20 is within a range where it can receive power from a power transmitter 40 that operates in cooperation with the base station device 30 (step S303). For example, the determination in step S303 is made based on whether the terminal 20 that transmitted the connection request has entered within a certain range of any of the power transmitters 40 that operate in cooperation with the base station device 30.

[0093] At this time, in response to receiving a connection request from the terminal 20, the base station control unit 31 of the base station device 30 may control all of the power transmitters 40 operating in cooperation to transmit beacon signals. In this case, each power transmitter 40 transmits a beacon signal.

[0094] If a terminal 20 is present within a certain range of any of the power transmitters 40, the terminal 20 transmits a response signal. The power transmitter 40 that has received the response signal notifies the base station device 30 of information indicating that the response signal has been received.

[0095] This allows the base station control unit 31 of the base station device 30 to identify which of the multiple power transmitters 40 the terminal 20 has entered within a certain range from. Then, the base station device 30 notifies the terminal 20 of information indicating the identified power transmitter 40, allowing the terminal control unit 21 to make the determination in step S303.

[0096] As described above, beacon signals are transmitted from all the power transmitters 40. In this case, the base station control unit 31 of the base station device 30 may stop transmission of beacon signals from each power transmitter 40 other than the power transmitter 40 corresponding to the terminal 20 that has transmitted the connection request. This makes it possible to reduce the consumption of power required for transmitting a beacon signal by each power transmitter 40 that does not need to transmit a beacon signal.

[0097] If the terminal 20 is not within a certain range from the power transmitter 40 (the power transmitter 40 that operates in cooperation with the base station device 30), the terminal control unit 21 determines No in step S303 and ends the flowchart in Fig. 7. If the terminal 20 is within a certain range from the power transmitter 40, the terminal control unit 21 determines Yes in step S303 and proceeds to step S304.

[0098] The terminal control unit 21 determines whether to request power reception (step S304). The terminal control unit 21 monitors the remaining battery level of the terminal 20, and may request power reception when the remaining battery level falls below a certain level. Furthermore, for example, the terminal control unit 21 may request power reception even when the remaining battery level is above a certain level if the battery consumption based on the CPU usage rate of the terminal 20 or the battery consumption used for screen display is above a certain level.

[0099] If power reception is not requested, the terminal control unit 21 determines No in step S304 and proceeds to step S305. The terminal control unit 21 controls network communication from the terminal second communication unit 24 via the base station device 30 (step S305). After executing step S305, the terminal control unit 21 returns the process to step S304. In this case, the terminal control unit 21 repeats the process of step S304 until it determines Yes in step S304.

[0100] If power reception is requested, the terminal control unit 21 determines Yes in step S304 and proceeds to step S306. The terminal control unit 21 causes the terminal second communication unit 24 to transmit a power transmission start request to the base station device 30 (step S306).

[0101] The terminal control unit 21 determines whether the power receiving unit 22 has received microwaves MW from the power transmitter 40 (step S307). The microwaves MW are microwaves transmitted by the power transmitting unit 42 of the power transmitter 40 identified in step S303. If the power receiving unit 22 has not received the microwaves MW, the terminal control unit 21 returns the process to step S307 and waits.

[0102] The terminal control unit 21 measures the level of the microwaves MW received by the power receiving unit 22 (step S308). Then, the terminal control unit 21 causes the terminal first communication unit 23 to transmit the measurement result measured in step S308 to the power transmitter 40 (step S309). By the processing of steps S308 and S309, the power transmitter 40 can transmit the microwaves MW at an appropriate level for the power receiving unit 22 to receive power. In parallel with steps S308 to S309, the terminal 20 may perform network communication via the base station device 30.

[0103] The terminal control unit 21 determines whether the remaining battery power of the terminal 20 is equal to or greater than a certain amount (step S311). If the remaining battery power of the terminal 20 is less than the certain amount, the terminal control unit 21 determines No in step S311 and returns the process to step S308.

[0104] As a result, microwaves MW are transmitted from the power transmitter 40 to the terminal 20 until the remaining battery charge of the terminal 20 reaches a certain level or more. Therefore, power is supplied to the terminal 20, and the battery of the terminal 20 is charged. Note that the terminal control unit 21 may make the determination in step S311 based on whether the battery consumption based on the CPU usage rate of the terminal 20, the battery consumption used for screen display, etc., is equal to or greater than a certain level.

[0105] If the terminal control unit 21 determines No in step S311, it may return the process to step S310. In this case, the processes of steps S308 and S309 are not performed, but the power receiving unit 22 can receive the microwaves MW.

[0106] When the remaining battery power of the terminal 20 becomes less than a certain amount, the terminal control unit 21 determines Yes in step S311 and proceeds to step S312. The terminal control unit 21 causes the terminal second communication unit 24 to transmit a charging end notification indicating that charging of the terminal 20 will be ended to the base station device 30 (step S312).

[0107] The base station device 30, which has received the charging completion notification, instructs the power transmitter 40, which has transmitted power to the terminal 20, to end power transmission. As a result, the power transmitter 40 stops transmitting the microwaves MW from the power transmitting unit 42. The power receiving unit 22 of the terminal 20 stops receiving the microwaves MW.

[0108] After executing step S312, the terminal control unit 21 ends the flowchart in Fig. 7. The flowchart in Fig. 7 is a process in which the terminal 20 receives microwaves MW from the power transmitter 40. After the flowchart in Fig. 7 ends, the terminal 20 can perform network communication via the base station device 30.

[0109] In this embodiment, the terminal 20, the base station device 30, and the power transmitter 40 operate in cooperation as described above. Unless the terminal 20 transmits a power transmission start request to the base station device 30, the base station device 30 does not transmit a power transmission start instruction to the power transmitter 40 operating in cooperation with the terminal 20. In this case, the power transmitter 40 maintains a sleep state, and does not transmit unnecessary microwaves MW to the terminal 20 (terminals that do not require power supply) located within the space R. This suppresses interference between the microwaves MW from the power transmitter 40 and the radio waves RW used for communication by the terminal 20. In addition, unnecessary power consumption caused by the power transmitter 40 transmitting unnecessary microwaves MW is suppressed.

[0110] Next, a modified example will be described. Fig. 8 is a diagram showing an example of a system 100 according to the modified example. The system 100 includes a terminal 120 and a base station device 130. The modified example does not include the power transmitter 40 of Fig. 1. The base station device 130 includes the function of the power transmitter 40 of the example of Fig. 3. In other words, the base station device 130 has a power transmission function.

[0111] For example, it is assumed that the base station device 130 is a base station device operated by a telecommunications carrier for general subscribers. However, the base station device 130 may also be applied to a local network such as local 5G.

[0112] The base station device 130 has a base station control unit 131, a power transmitting unit 132, and a base station communication unit 133. The base station device 130 performs the operations of both the base station device 30 and the power transmitter 40 described above. The base station control unit 131 executes the processes of the base station control unit 31 and the power transmitter control unit 41 in FIG.

[0113] The power transmitting unit 132 is similar to the power transmitting unit 42 in Fig. 3. The base station communication unit 133 has the functions of the base station first communication unit 32 and the power transmitter first communication unit 43 in Fig. 3. Since the base station device 30 and the power transmitter 40 in Fig. 3 are configured as an integrated unit, the base station second communication unit 33 and the power transmitter second communication unit 44 in Fig. 3 are not necessary.

[0114] Terminal 120 has terminal control unit 121, power receiving unit 122, and terminal communication unit 123. Terminal control unit 121 is similar to terminal control unit 21 in Fig. 3, and power receiving unit 122 is similar to power receiving unit 22 in Fig. 3. Terminal communication unit 123 has the functions of terminal first communication unit 23 and terminal second communication unit 24 in Fig. 3.

[0115] The configuration of the system 100 of this modified example also makes it possible to suppress interference between the microwaves MW for power supply from the base station device 130 to the terminal 120 and the radio waves RW for communication.

[0116] The present disclosure is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention. Furthermore, new technical features can be formed by combining the technical means disclosed in the embodiments. [Explanation of symbols]

[0117] 10 system, 20 terminal, 21 terminal control unit, 22 power receiving unit, 23 terminal first communication unit, 24 terminal second communication unit, 30 base station device, 31 base station control unit, 32 base station first communication unit, 33 base station second communication unit, 40 power transmitter, 41 power transmitter control unit, 42 power transmitter unit, 43 power transmitter first communication unit, 44 power transmitter second communication unit, MW microwave, RW radio wave for communication

Claims

1. A power transmission system including a power receiver, a base station device, and a power transmitter, The power receiver includes: a power receiving unit capable of receiving radio waves for power supply transmitted from the power transmitter; a power receiver control unit that controls transmission of a power transmission start request to the base station device and transmission of a power transmission stop request to the power transmitter, The base station device a base station control unit that controls transmission of a power transmission start instruction to the power transmitter when the power transmission start request is received from the power receiver, The power transmitter associated with the base station device, a power transmission unit that transmits the power supply radio waves within a certain range; a power transmitter control unit that causes the power transmitter unit to start transmitting power to the power receiver when receiving the power transmission start instruction from the base station device, and causes the power transmitter unit to stop transmitting power to the power receiver when receiving the power transmission stop request from the power receiver, Power transmission system.

2. The power transmission system according to claim 1, wherein the base station control unit controls the power transmitter so as not to send the power transmission start instruction when another power receiver that is not capable of receiving the power supply radio waves is connected to the base station device.

3. The power transmission system according to claim 1 or 2, wherein the base station control unit transmits a wake-up request to the power transmitter in a sleep state when the power receiving unit is capable of receiving power from the power transmitter and has received the power transmission start request from the power receiver.

4. The power transmission system of claim 3, wherein after receiving the wake-up request, the power transmitter control unit searches to determine whether the power receiver is present within the certain range, and if it detects that the power receiver is present within the certain range, causes the power transmitter unit to start transmitting power to the power receiver.

5. The power transmission system described in claim 3 or 4, wherein when the power transmitter control unit receives the power transmission stop request from the power receiver, it stops power transmission from the power transmitter unit, then transitions the power transmitter to the sleep state and sends a notification to the base station device indicating that the power transmitter has transitioned to the sleep state.

6. The power transmission system according to any one of claims 3 to 5, wherein, when there are multiple power receivers capable of receiving power from the power transmitter within the certain range, the power transmitter control unit controls to stop power transmission from the power transmitter unit after power transmission to all of the multiple power receivers has been completed.

7. The power transmission system according to any one of claims 3 to 6, wherein the base station control unit adjusts the timing of power transmission from the power transmitter to the power receiver so as not to interfere with communication between the base station device and the power receiver and power transmission from the power transmitter to the power receiver.

8. The power transmission system according to claim 7 , wherein the base station control unit controls communication between the base station device and the power receiver and power transmission from the power transmitter to the power receiver in a time-division manner.

9. The power transmission system according to claim 8 , wherein the base station control unit allocates each of a plurality of time periods of time-divided power transmission from the power transmitter to the power receiver to the plurality of power transmitters in turn.

10. the power receiver is a UE that communicates with the base station device, The power transmission system according to any one of claims 1 to 7, wherein the base station control unit determines whether the UE communicating with the base station device is a UE capable of receiving power supply radio waves, based on a notification included in an attach procedure performed between the UE and the base station device.

11. The power transmission system according to claim 10 , wherein the notification is included in UE Capability information.

12. The power transmission system according to claim 1 , wherein the radio waves for power supply are microwaves.

13. A base station device, a power transmission unit that transmits radio waves for power supply to a power receiver that is capable of receiving the radio waves for power supply; a control unit that, when receiving a power transmission start request from the power receiver, controls to send a power transmission start instruction to the power transmitter unit to start power transmission; The base station device, when the control unit receives a power transmission start instruction from the power receiver, causes the power transmission unit to start transmitting power to the power receiver, and when the control unit receives a power transmission stop request from the power receiver, causes the power transmission unit to stop transmitting power to the power receiver, and when another power receiver that does not have the function of receiving the power supply radio waves is connected to the base station device, controls the power transmission unit so as not to transmit the power supply radio waves to the other power receiver.

14. A power receiver, a power receiving unit capable of receiving radio waves for power supply transmitted from a power transmitter that transmits the radio waves for power supply within a certain range; a power receiver control unit that transmits a power transmission start request to a base station device that operates in cooperation with the power transmitter and controls transmission of a power transmission stop request to the power transmitter, When the base station device receives the power transmission start request from the power receiver, the base station device transmits a power transmission start instruction to the power transmitter to instruct the power transmitter to start transmitting power; The power transmitter that has received the power transmission start instruction from the base station device starts transmitting power to the power receiving unit, and the power transmitter that has received the power transmission stop request stops transmitting power to the power receiving unit. Power receiver.

15. A power transmitter that operates in cooperation with a base station device, a power transmission unit that transmits radio waves for power supply within a certain range; a power transmitter control unit that, when receiving a power transmission start instruction from the base station device, starts power transmission from the power transmitter unit to a power receiver that is capable of receiving power supply radio waves transmitted from the power transmitter unit, and, when receiving a power transmission stop request from the power receiver, stops power transmission from the power transmitter unit to the power receiver; a power transmission start request to the power receiver is transmitted from the power receiver to the base station device, and a power transmission stop request is transmitted from the power receiver to the power transmitter; When the base station device receives the power transmission start request from the power receiver, the power transmission start instruction is transmitted from the base station device to the power transmitter. Power transmitter.

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