Power receiving device, control method, and program

Abstract

To provide a power receiving device for receiving power by switching a connection destination of an antenna at appropriate timing without increasing cost, and a control program for the power receiving device.SOLUTION: A power receiving device includes a first wireless communication unit that performs first wireless communication with a power transmitting device by using a first antenna, a second wireless communication unit that performs second wireless communication with the power transmitting device by using a second antenna, a power receiving unit that receives power from the power transmitting device by using the second antenna, a switching unit that switches a connection destination of the second antenna to second wireless communication means or power receiving means, a control unit that controls the first wireless communication unit, the second wireless communication unit, and the switching unit. The control unit controls the switching unit to switch the connection destination of the second antenna from the second wireless communication unit to the power receiving unit when the first wireless communication unit is connected to the power transmitting device, and uses the first wireless communication unit to communicate with the power transmitting device such that the power transmitting device starts power transmission after the connection of the second antenna to the power receiving unit is completed.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a wireless power transmission and reception technology using microwaves. [Background technology]

[0002] The space transmission type wireless power transmission system proposed by the Ministry of Internal Affairs and Communications, described in Non-Patent Document 1, is expected to be deployed in a wide range of markets by transmitting power using the 2.4 GHz frequency band used for wireless LANs, etc.

[0003] Patent document 1 describes a power transmission device that, in an apparatus having a power transmission antenna and a communication antenna, disconnects the power transmission antenna from the power transmission unit when switching from power transmission to communication, and disconnects the communication antenna from the communication unit when switching from communication to power transmission. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2017-085700 [Non-patent literature]

[0005] [Non-Patent Document 1] Draft Report of the Working Group on Space-Based Wireless Power Transmission Systems (as of 4:00 PM, May 20, 2020) Information and Communications Council, Information and Communications Technology Subcommittee, Land Wireless Communications Committee Summary of the Invention [Problem to be solved by the invention]

[0006] In contrast to Patent Document 1, there is a device that uses a common antenna for wireless power reception and wireless communication, and switches the connection of the antenna between the wireless power reception circuit and the wireless communication circuit to perform wireless power reception and wireless communication. In such a device, it is necessary to switch the connection of the antenna at an appropriate time to prevent overvoltage caused by receiving transmitted power waves during wireless communication. Furthermore, in case overvoltage caused by power transmission is applied to the wireless communication circuit, measures such as making the wireless communication circuit highly voltage-resistant are required, which leads to increased costs.

[0007] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to realize a technology that can receive power by switching the connection destination of an antenna at an appropriate timing without increasing costs. [Means for solving the problem]

[0008] In order to solve the above problems and achieve the object, the present invention provides a power receiving device that receives power wirelessly transmitted from a power transmitting device, the power receiving device comprising: a first wireless communication means that performs first wireless communication with the power transmitting device using a first antenna; a second wireless communication means that performs second wireless communication with the power transmitting device using a second antenna; a power receiving means that receives power from the power transmitting device using the second antenna; a switching means that switches the connection of the second antenna to the second wireless communication means or the power receiving means; and a control means that controls the first wireless communication means, the second wireless communication means, and the switching means, wherein when the first wireless communication means is connected to the power transmitting device, the control means controls the switching means to switch the connection of the second antenna from the second wireless communication means to the power receiving means, and communicates with the power transmitting device using the first wireless communication means so that the power transmitting device starts transmitting power after the connection of the second antenna to the power receiving means is completed. [Effects of the Invention]

[0009] According to the present invention, it is possible to receive power by switching the connection destination of the antenna at an appropriate timing without increasing costs. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 2 is a block diagram showing the configuration of a power transmitting device and a power receiving device according to the embodiment. [Figure 2] 6 is a flowchart showing a first communication and power transmission / reception control by the power receiving device of the present embodiment. [Figure 3] 10 is a flowchart showing second communication and power transmission / reception control by the power receiving device of the present embodiment. [Figure 4] 10 is a flowchart showing a third communication and power transmission / reception control by the power receiving device of the present embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the scope of the invention claimed. Although multiple features are described in the embodiments, not all of these multiple features are necessarily essential to the invention, and multiple features may be combined arbitrarily. Furthermore, in the accompanying drawings, the same reference numerals are used to designate the same or similar components, and redundant explanations will be omitted. <Device Configuration> First, the configuration of a power receiving device 101 and a power transmitting device 201 according to this embodiment will be described with reference to FIG.

[0012] The power receiving device 101 is an electronic device that receives power wirelessly transmitted from the power transmitting device 201. The power receiving device 101 can be carried by a user and can operate as a portable terminal such as an imaging device like a digital camera, a mobile phone like a smartphone, a tablet device, or a mobile game console, powered by a rechargeable battery.

[0013] The power receiving device 101 has a wireless communication function and a wireless charging function. The wireless communication function is a function of a second wireless communication method (for example, Wi-Fi (registered trademark)) and a first wireless communication method (for example, a first wireless communication method) that consumes less power and has a lower communication speed than the second wireless communication method. wirelessThe device is compatible with two standards of communication methods (for example, Bluetooth (registered trademark)) and includes a first antenna conforming to the first wireless communication method and a second antenna conforming to the second wireless communication method.

[0014] When the power receiving device 101 and the power transmitting device 201 approach each other by a predetermined distance, they are automatically connected using a first wireless communication method, and remain connected at all times until they move apart by more than the predetermined distance.

[0015] The power transmitting device 201 is a charging device that can operate using power constantly supplied from a household outlet, etc. The power transmitting device 201 transmits power to the power receiving device 101 wirelessly.

[0016] <Configuration of Power Receiving Device 101> First, the configuration of the power receiving device 101 of this embodiment will be described with reference to FIG. 1(a).

[0017] 1(a) is a block diagram showing the configuration of a power receiving device 101 according to this embodiment. In the following description, the external device is, for example, a power transmitting device 201, but is not limited to this.

[0018] The control unit 118 has a memory that stores programs for controlling each component of the power receiving device 101, and a processor such as a CPU or MPU that controls each component of the power receiving device 101 by executing the programs stored in the memory.

[0019] The control unit 118 controls the switching unit 112, the second wireless communication unit 114, the first wireless communication unit 116, and the charging circuit 117, which will be described later.

[0020] The battery 119 is a power source that supplies power for operating the power receiving device 101. The battery 119 is, for example, a rechargeable battery such as a lithium ion battery. The battery 119 supplies power to each component of the power receiving device 101.

[0021] The first antenna 115 is a dedicated antenna having a configuration that complies with the first wireless communication system of the first wireless communication unit 116 .

[0022] The first wireless communication unit 116 executes communication processing with the external device via the first antenna 115 in accordance with a first wireless communication method. The first wireless communication method is a wireless communication standard that performs communication at lower power consumption and lower communication speed than the second wireless communication method described below. The first wireless communication method, like Bluetooth (registered trademark), performs low-power (approximately 10 mW) and small-capacity (10 kbps) data communication, and continuously communicates with the external device without disconnection.

[0023] The second antenna 111 has an antenna element and is capable of transmitting and receiving radio waves to and from an external device. The second antenna 111 also has a configuration capable of receiving power that is converted into radio waves and transmitted from the power transmitting device 201. The second antenna 111 is used both as an antenna for wireless communication and as an antenna for wireless power reception.

[0024] The switching unit 112 is a switch that switches the connection destination of the second antenna 111 between a power receiving resonant circuit 120 (power receiving unit 113) described later and a communication resonant circuit 121 (second wireless communication unit 114). In a normal state or initial state, the second antenna 111 is connected to the communication resonant circuit 121 (second wireless communication unit 114). Then, in response to a control command from the control unit 118, the switching unit 112 switches the connection destination of the second antenna 111 from the communication resonant circuit 121 (second wireless communication unit 114) to Power receiving The power resonant circuit 120 (power receiving unit 113) is switched to the power resonant circuit 120.

[0025] The power receiving resonant circuit 120 is a circuit including elements such as a coil and a capacitor, and is designed to resonate at frequencies in the 2.4 GHz band or 5.0 GHz band used in Wi-Fi (registered trademark), for example.

[0026] The power receiving unit 113 is a rectifier circuit that converts the voltage of the power output from the power receiving resonant circuit 120, rectifies it to a DC voltage that allows each component of the power receiving device 101 to operate, and outputs it to the charging circuit 117 in the subsequent stage.

[0027] Charging circuit 117 supplies power to battery 119 to charge battery 119. Charging circuit 117 converts the DC voltage output from power receiving unit 113 into a predetermined voltage for charging battery 119, and supplies power to battery 119.

[0028] The communication resonant circuit 121 is a circuit including elements such as a coil and a capacitor, and similar to the power receiving resonant circuit 120, is designed to resonate at frequencies in the 2.4 GHz band or 5.0 GHz band used in Wi-Fi (registered trademark), for example.

[0029] The second wireless communication unit 114 executes communication processing in accordance with a second wireless communication method with an external device via the second antenna 111 and the communication resonant circuit 121. The second wireless communication method is a wireless communication standard that performs communication with higher power consumption and higher communication speed than the first wireless communication method. The second wireless communication method performs data communication with high power (about 100 mW) and large capacity (tens of Mbps), like Wi-Fi (registered trademark).

[0030] <Configuration of power transmitting device 201> Next, referring to FIG. b ), the configuration and functions of the power transmitting device 201 of this embodiment will be described.

[0031] 1(b) is a block diagram showing the configuration of a power transmitting device 201 according to this embodiment. In the following description, the external device is, for example, the power receiving device 101, but is not limited to this.

[0032] The control unit 218 has a memory that stores programs for controlling each component of the power transmission device 201, and a processor such as a CPU or MPU that controls each component of the power transmission device 201 by executing the programs stored in the memory.

[0033] The control unit 218 controls the switching unit 212, the second wireless communication unit 214, and the first wireless communication unit 216, which will be described later.

[0034] The first antenna 215 is a dedicated antenna having a configuration that complies with the first wireless communication method of the first wireless communication unit 216 .

[0035] The first wireless communication unit 216 executes communication processing in accordance with a first wireless communication method with an external device via the first antenna 215. The first wireless communication method is a wireless communication standard such as Bluetooth (registered trademark) that consumes less power and has a lower communication speed than a second wireless communication method described below.

[0036] The second antenna 211 includes an antenna element and is capable of transmitting and receiving radio waves to and from an external device. The second antenna 211 also includes a configuration capable of converting power into radio waves and transmitting the power to the power receiving device 101.

[0037] The switching unit 212 is a switch that switches the connection destination of the second antenna 211 between the power transmission resonant circuit 220 or the communication resonant circuit 221 (second wireless communication unit 214), which will be described later.

[0038] The power transmission resonant circuit 220 and the communication resonant circuit 221 are circuits including elements such as coils and capacitors, and are designed to resonate at frequencies in the 2.4 GHz band or 5.0 GHz band used in Wi-Fi (registered trademark), for example.

[0039] The second wireless communication unit 214 executes communication processing in accordance with a second wireless communication method with an external device via the second antenna 211 and the communication resonant circuit 221. The second wireless communication method is a wireless communication standard such as Wi-Fi (registered trademark) that has higher power consumption and higher communication speed than the first wireless communication method.

[0040] <First Communication and Power Transmission and Reception Control> Next, the first communication and power transmission and reception control by the power receiving device 101 of this embodiment will be described with reference to the flowchart of FIG.

[0041] 2 is realized by the control unit 118 of the power receiving apparatus 101 executing a program stored in memory to control each component of the power receiving apparatus 101. The same applies to the processes in FIGS. 3 and 4.

[0042] In step S201, when the power receiving device 101 approaches the power transmitting device 201 within a predetermined distance, the control unit 118 controls the first antenna 115 of the power receiving device 101 to receive the signal that is constantly output by the first wireless communication unit 216 of the power transmitting device 201 via the first antenna 215.

[0043] In step S202, the control unit 118 establishes a connection between the first wireless communication unit 116 and the first wireless communication unit 216 of the power transmitting device 201 using the first wireless communication method, connecting the power receiving device 101 and the power transmitting device 201 so that they can communicate with each other.

[0044] In step S203, the control unit 118 receives a request for information transmitted from the first wireless communication unit 216 of the power transmitting device 201 via the first antenna 215. The information requested from the power transmitting device 201 is, for example, information on the charge state of the battery 119 of the power receiving device 101, the operating state (operating, powered off, etc.), the power to be transmitted, and the frequency of the radio waves to be transmitted.

[0045] In step S204, the control unit 118 causes the switching unit 112 to switch the connection destination of the second antenna 111 to the power receiving resonant circuit 120.

[0046] In step S205, when the control unit 118 determines that the second antenna 111 is connected to the power receiving unit 113 via the power receiving resonant circuit 120, the control unit 118 advances the process to step S206.

[0047] In step S206, the control unit 118 generates response data to the information request received from the power transmitting device 201 in step S203. , th The power is transmitted from the first wireless communication unit 116 to the power transmitting device 201 via the first antenna 115 .

[0048] In step S207, the control unit 218 electric The power receiving device 101 starts receiving power transmitted from the power transmitting device 201 at a power level and frequency according to the response data received from the power receiving device 101 .

[0049] According to the first communication and power transmission / reception control, in a state where the second antenna 111 of the power receiving device 101 is connected to the power receiving section 113 via the power receiving resonant circuit 120, 2 Power transmission starts from the antenna 211. This makes it possible to prevent an overvoltage caused by power reception from being applied to the second wireless communication unit 114 of the power receiving device 101.

[0050] <Second Communication and Power Transmission / Reception Control> Next, the second communication and power transmission / reception control by the power receiving device 101 of this embodiment will be described with reference to the flowchart of FIG.

[0051] In step S301, the control unit 118 2 The power transmitted from the second wireless communication unit 214 of the power receiving unit 113 via the second antenna 211 is received by the second antenna 111. Then, the control unit 118 charges the battery 119 with the power output to the charging circuit 117 via the power receiving resonant circuit 120 and the power receiving unit 113. The control unit 118 detects the output voltage of the battery 119, and when it determines that the battery 119 is fully charged, the control unit 118 proceeds to step S302.

[0052] In step S302, the control unit 118 transmits information from the first wireless communication unit 116 via the first antenna 115 to the power transmitting device 201 notifying that the battery 119 is fully charged.

[0053] When the power transmitting device 201 receives information notifying that the battery 119 is fully charged, the control unit 218 of the power transmitting device 201 stops transmitting power and transmits information notifying that power transmission has stopped from the first wireless communication unit 216 to the power receiving device 101 via the first antenna 215.

[0054] In step S303, when the first wireless communication unit 116 receives information notifying that power transmission has been stopped from the power transmitting device 201 via the first antenna 115, the control unit 118 advances the process to step S304.

[0055] In step S304, the control unit 118 instructs the switching unit 112 to switch the connection destination of the second antenna 111 to the resonant circuit 121 for communication.

[0056] In step S305, when the control unit 118 determines that the switching by the switching unit 112 has been completed and the second antenna 111 has been connected to the communication resonant circuit 121, the control unit 118 ends the process.

[0057] According to the second communication and power transmission / reception control, after power transmission from the power transmitting device 201 is stopped, the second antenna 111 of the power receiving device 101 is connected to the communication resonant circuit 121, thereby preventing overvoltage due to power reception from being applied to the second wireless communication unit 114 of the power receiving device 101.

[0058] <Third Communication and Power Transmission / Reception Control> Next, the third communication and power transmission / reception control by the power receiving device 101 of this embodiment will be described with reference to the flowchart of FIG.

[0059] In FIG. 4, steps S201 to S204 and steps S205 to S207 are the same as those in FIG. 2, and therefore the description thereof will be omitted.

[0060] In step S401, the control unit 118 measures the time required from when the switching unit 112 starts the process of switching the connection destination of the second antenna 111 to the power receiving resonant circuit 120 in step S204 until the process is completed. Then, the control unit 118 determines whether the required time is equal to or greater than a predetermined time (for example, 100 msec). If the control unit 118 determines that the required time is equal to or greater than the predetermined time (for example, 100 msec), the process returns to step S402. Proceed to Therefore, if it is determined that the required time is less than a predetermined time (for example, 100 msec), the process proceeds to step S205.

[0061] In step S402, the control unit 118 transmits information notifying that the switching by the switching unit 112 has been completed and that the second antenna 111 has been connected to the power receiving resonant circuit 120 from the first wireless communication unit 116 to the power transmitting device 201 via the first antenna 115. The power transmitting device 201 does not start power transmission until it receives information notifying that the second antenna 111 has been connected to the power receiving resonant circuit 120 from the power receiving device 101, and does not disconnect communication due to a timeout even if it has not received a response for a predetermined time or longer since it transmitted a request to the power receiving device 101 in step S203.

[0062] According to the third communication and power transmission / reception control, even if the power transmitting device 201 does not receive a response for a predetermined time or more after sending a request to the power receiving device 101, communication disconnection due to a timeout can be avoided, and a stable connection can be achieved even if it takes time for the power receiving device 101 to switch the connection destination of the second antenna 111 to the power receiving resonant circuit 120.

[0063] [Other embodiments] The present invention can also be realized by supplying a program that realizes one or more functions of each embodiment to a system or device via a network or storage medium, and having one or more processors in the computer of the system or device read and execute the program. The present invention can also be realized by a circuit (e.g., ASIC) that realizes one or more functions.

[0064] The invention is not limited to the above-described embodiments, and various changes and modifications can be made without departing from the spirit and scope of the invention. Accordingly, the following claims are appended to apprise the public of the scope of the invention. [Explanation of symbols]

[0065] REFERENCE SIGNS LIST 101...power receiving device, 118...controller, 111...second antenna, 114...second wireless communication unit, 115...first antenna, 116...first wireless communication unit, 112...switching unit, 113...power receiving unit, 117...charging circuit, 119...battery, 201...power transmitting device

Claims

1. In a power receiving device that receives power wirelessly transmitted from a power transmitting device, a first wireless communication means for performing first wireless communication with the power transmitting device using a first antenna; second wireless communication means for performing second wireless communication with the power transmitting device using a second antenna; power receiving means for receiving power from the power transmitting device using the second antenna; a switching means for switching the connection destination of the second antenna to the second wireless communication means or the power receiving means; a control unit that controls the first wireless communication unit, the second wireless communication unit, and the switching unit; The control means controls the switching means to switch the connection of the second antenna from the second wireless communication means to the power receiving means when the first wireless communication means is connected to the power transmitting device, and communicates with the power transmitting device using the first wireless communication means so that the power transmitting device starts transmitting power after the connection of the second antenna to the power receiving means is completed.

2. The power receiving device described in claim 1, characterized in that after a connection with the power transmitting device using the first wireless communication means is established, the control means controls the switching means to connect the second antenna connected to the second wireless communication means to the power receiving means when it receives a notification from the power transmitting device requesting information about the power receiving device.

3. 3. The power receiving device according to claim 2, wherein the control means transmits a response to the request and starts receiving power from the power transmitting device after the connection of the second antenna to the power receiving means is completed.

4. The power receiving device according to any one of claims 1 to 3, characterized in that the control means notifies the power transmitting device that the connection of the second antenna to the power receiving means has been completed if the time required to connect the second antenna to the power receiving means is equal to or longer than a predetermined time.

5. the control means further includes charging means for charging a battery using the power received from the power transmission device; transmitting a notification that the battery is fully charged to the power transmitting device using the first wireless communication means; The power receiving device described in claim 1, characterized in that when a notification that power transmission has been stopped is received from the power transmitting device using the first wireless communication means, the switching means is controlled to connect the second antenna connected to the power receiving means to the second wireless communication means.

6. the first wireless communication means performs wireless communication with lower power consumption and lower communication speed than the second wireless communication means; 6. The power receiving device according to claim 1, wherein the second antenna is used in common as an antenna for the second wireless communication or an antenna for receiving power from the power transmitting device.

7. A control method for a power receiving device that receives power wirelessly transmitted from a power transmitting device, comprising: The power receiving device is a first wireless communication means for performing first wireless communication with the power transmitting device using a first antenna; second wireless communication means for performing second wireless communication with the power transmitting device using a second antenna; power receiving means for receiving power from a power transmitting device using the second antenna; a switching means for switching the connection destination of the second antenna to the second wireless communication means or the power receiving means; a control unit that controls the first wireless communication unit, the second wireless communication unit, and the switching unit; The control method includes: controlling the switching means to switch the connection of the second antenna from the second wireless communication means to the power receiving means when the first wireless communication means is connected to the power transmitting device; a step of communicating with the power transmitting device using the first wireless communication means so that the power transmitting device starts transmitting power after connection of the second antenna to the power receiving means is completed.

8. A program for causing a computer to function as the control means for the power receiving device according to any one of claims 1 to 6.

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