Electric power transmission device, electric power reception device, method performed by electric power transmission device, method performed by electric power reception device, and program

Abstract

An electric power transmission device according to one embodiment of the present disclosure transmits electric power to an electric power reception device in a wireless manner, and is characterized by comprising: an electric power transmission coil; an enclosure that encloses the electric power transmission coil; a transmission means that transmits, to the electric power reception device, first information that pertains to the distance between the electric power transmission coil and the enclosure; a reception means that receives, from the electric power reception device, second information that corresponds to the first information; and a determination means that determines a coupling state on the basis of the second information.

Description

Power transmission equipment, power receiving equipment, methods performed by power transmission equipment, methods performed by power receiving equipment, and programs

[0001] This disclosure relates to power transmission equipment, power receiving equipment, methods performed by power transmission equipment, methods performed by power receiving equipment, and programs.

[0002] Japanese Patent Publication No. 2012-244732 discloses a power transmission device that improves the accuracy of detecting metallic foreign objects by detecting the state of electromagnetic coupling with the secondary coil based on a correction value, thereby suppressing the influence of the metal casing of a portable device or the like, which is the receiving side (secondary side). Hereinafter, the state of electromagnetic coupling will also be referred to as the electromagnetic coupling state or simply the coupling state.

[0003] Japanese Patent Publication No. 2012-244732

[0004] The coupling state between the power transmission device and the power reception device is affected by the distance between the power transmission coil and the power reception coil. Therefore, in the conventional technology described above, if the coefficient (correction value) used to detect or determine the coupling state between the power transmission device and the power reception device is not determined based on the distance between the power transmission coil and the power reception coil, it may not be possible to properly determine the coupling state. As a result, it may become impossible to properly detect metallic foreign objects, and wireless power transmission from the power transmission device to the power reception device may not be performed properly.

[0005] One aspect of this disclosure, in view of the above, aims to provide a technology for appropriately determining the state between a power transmission device and a power receiving device.

[0006] A power transmission device according to one aspect of the present disclosure is a power transmission device that wirelessly transmits power to a power receiving device, and is characterized by comprising: a power transmission coil; an enclosure enclosing the power transmission coil; a transmitting means for transmitting first information relating to the distance between the power transmission coil and the enclosure to the power receiving device; a receiving means for receiving second information corresponding to the first information from the power receiving device; and a determining means for determining the coupling state based on the second information.

[0007] According to one aspect of this disclosure, the state between the power transmission device and the power receiving device can be appropriately determined.

[0008] This figure shows an example configuration of a wireless power transmission system according to the first embodiment. This is a functional block diagram showing an example configuration of a power transmission device according to the first embodiment. This is a functional block diagram showing an example configuration of a power receiving device according to the first embodiment. This figure illustrates a threshold setting method in state detection using the Power Loss method. This figure illustrates a Q-value measurement method. This figure illustrates a Q-value measurement method. This is a block diagram illustrating an example of the functional configuration of the control unit of the power transmission device according to the first embodiment. This is a flowchart showing an example of processing of the power transmission device. This is a flowchart showing an example of processing of the power receiving device. This figure illustrates the distance between the antenna (coil) and the enclosure. This figure illustrates the distance between the antenna (coil) and the enclosure. This is a flowchart showing an example of processing of the power transmission device according to the first embodiment. This is a flowchart showing an example of processing of the power receiving device according to the first embodiment. This is a flowchart showing an example of processing of the power transmission device according to the second embodiment. This is a flowchart showing an example of processing of the power receiving device according to the second embodiment. This is a flowchart showing an example of processing

[0009] The embodiments of this disclosure will be described in detail below with reference to the accompanying drawings. Although the embodiments describe multiple features, not all of these features are essential to the invention, and the features may be combined in any way. Furthermore, in the accompanying drawings, the same or similar configurations will be given the same reference numeral. Each embodiment shows a wireless charging system to which a wireless power transmission system is applied. As an example, wireless power transmission based on the standards formulated by the Wireless Power Consortium (WPC), a standardization organization for wireless charging (hereinafter referred to as the WPC standard), will be described. An example of a WPC standard is the Qi standard.

[0010] [First Embodiment] This embodiment will be described with reference to the drawings. Figure 1 is a diagram showing an example of the configuration of a wireless charging system according to the first embodiment. This wireless charging system comprises a power transmission device 100, a power receiving device 200, and a charging cradle (Interface Surface) 300.

[0011] In the following, for the sake of brevity, the power receiving device 200 may be referred to as RX200 and the power transmitting device 100 as TX100. The detailed configurations of TX100 and RX200 will be described later using Figures 2 and 3.

[0012] The RX200 is an electronic device that receives power wirelessly from the TX100 and charges its internal battery while placed on the charging cradle 300. The TX100 is an electronic device that wirelessly transmits power to the RX200 while it is placed on the charging cradle 300. Since the charging cradle 300 constitutes part of the TX100, in the following, when the RX200 is "placed on the charging cradle 300", it may be referred to as "placed on the TX100". The spatial range in which the RX200 can receive power from the TX100 is schematically shown in Figure 1 by the dotted line frame 400. The RX200 and TX100 may have functions to perform applications other than wireless charging. For example, the RX200 is a smartphone, and the TX100 is an accessory device for charging the RX200's battery. However, this disclosure is not limited to this example.

[0013] Next, an example of the configuration of the power transmission device 100 will be described with reference to Figure 2. Figure 2 is a functional block diagram showing an example of the configuration of the power transmission device 100. TX100 includes a control unit 101, a power supply unit 102, a power transmission unit 103, a first communication unit 104, a power transmission antenna (power transmission coil) 105, a memory 106, a resonant capacitor 107, a switch unit 108, a second communication unit 109, and a user interface unit 110. Hereinafter, the user interface will be referred to as UI. In Figure 2, each functional block element is shown as a separate entity, but any multiple functional block elements may be implemented as the same hardware module (for example, on the same chip).

[0014] The control unit 101 controls the entire TX100 by executing a control program stored in the memory 106. The control unit 101 also performs power transmission control, including communication for device authentication in the TX100. Furthermore, the control unit 101 can perform control for applications other than wireless power transmission. The control unit 101 is configured to include one or more processors, such as a CPU (Central Processing Unit) or an MPU (Micro Processing Unit). Alternatively, the control unit 101 may be configured to include hardware such as an Application Specific Integrated Circuit (ASIC). The control unit 101 may also be configured to include an array circuit, such as an FPGA (Field Programmable Gate Array), compiled to perform predetermined processing. The control unit 101 can perform processes to store information that should be stored during the execution of various processes in the memory 106, and can also perform timing processes using a timer (not shown).

[0015] The power supply unit 102 supplies power to each functional block element. The power supply unit 102 includes, for example, a power connection circuit to the commercial power supply and a battery. The battery is charged by power supplied from the commercial power supply.

[0016] The power transmission unit 103 converts the DC power or AC power input from the power supply unit 102 into AC power in the frequency band used for wireless power transmission, and inputs the converted AC power to the power transmission antenna 105 to generate electromagnetic waves for the RX200 to receive power. For example, the power transmission unit 103 is equipped with an inverter and converts the DC voltage supplied by the power supply unit 102 into an AC voltage using a switching circuit in a half-bridge or full-bridge configuration. The power transmission unit 103 includes a plurality of FETs (Field Effect Transistors) that constitute a bridge, and a gate driver that controls the ON / OFF state of the plurality of FETs.

[0017] The power transmission unit 103 controls the intensity of the electromagnetic waves (transmitted power) output by adjusting the voltage (transmission voltage) or current (transmission current), or both, input to the power transmission antenna 105. The strength of the electromagnetic waves (strength of the transmitted power) is controlled by the magnitude of the transmission voltage or transmission current.

[0018] Alternatively, the power transmission unit 103 controls the intensity of the electromagnetic waves it outputs (power transmission) by adjusting the voltage, current, or both input to the inverter it has. The voltage input to this inverter will be referred to as the inverter input voltage below. The current input to this inverter will be referred to as the inverter input current below. The strength of the electromagnetic waves (strength of the power transmission) is controlled by the magnitude of the inverter input voltage or inverter input current.

[0019] Alternatively, the power transmission unit 103 controls the intensity of the electromagnetic waves (transmitted power) to be output by adjusting the voltage, current, or both output from the inverter of the power transmission unit 103. The voltage output from this inverter will be referred to as the inverter output voltage below.

[0020] Furthermore, the current output from this inverter will be referred to as the inverter output current below. The strength of the electromagnetic waves (the strength of the transmitted power) is controlled by the magnitude of the inverter output voltage or inverter output current.

[0021] The power transmission unit 103 controls the output power of AC frequency electromagnetic waves so that it can start or stop power transmission by the power transmission antenna 105 or control the intensity of the electromagnetic waves to be output, based on instruction signals from the control unit 101. The power transmission unit 103 is also assumed to have the power supply capacity to output / supply 15 watts (W) of power to the charging section of the power receiving device 200 which complies with the WPC standard.

[0022] The first communication unit 104 is connected to the control unit 101 and the power transmission unit 103, and communicates with the RX200 for power transmission control based on the WPC standard. The first communication unit 104 performs frequency shift modulation of the electromagnetic waves output from the power transmission antenna 105 and transmits information to the RX200 for communication. The first communication unit 104 also demodulates the electromagnetic waves transmitted from the power transmission antenna 105, which have been modulated by the RX200, and obtains the information transmitted by the RX200. Communication by the first communication unit 104 is performed by superimposing a communication signal on the electromagnetic waves transmitted from the power transmission antenna 105. The first communication unit 104 performs so-called in-band communication.

[0023] Memory 106 can store information regarding the status of TX100 and RX200, in addition to the control program. This information regarding the status of TX100 and RX200 includes the power transmission value, power reception value, etc. Information regarding the status of TX100 is acquired by the control unit 101. Information regarding the status of RX200 is acquired by the control unit of RX200 and can be received by the first communication unit 104 or the second communication unit 109, which will be described later.

[0024] The switch unit 108 is connected in parallel to the series circuit of the resonant capacitor 107 and the power transmitting antenna 105. The control unit 101 transmits a control signal to the switch unit 108 to control its ON / OFF state. The power transmitting antenna 105 is connected to the resonant capacitor 107. When the switch unit 108 is turned ON and short-circuited by the control signal from the control unit 101, the power transmitting antenna 105 and the resonant capacitor 107 form a series resonant circuit and resonate at a specific frequency fA. At this time, current flows through the closed circuit formed by the power transmitting antenna 105, the resonant capacitor 107 and the switch unit 108. On the other hand, when the switch unit 108 is turned OFF by the control signal from the control unit 101 and the circuit is opened, power is supplied to the power transmitting antenna 105 and the resonant capacitor 107 from the power transmitting unit 103.

[0025] The second communication unit 109 is connected to the control unit 101 and communicates with the RX200 using a standard different from the WPC standard. For example, the second communication unit 109 communicates with the RX200 using an antenna (not shown) different from the transmitting antenna 105. Examples of communication methods used by the second communication unit 109 include wireless LAN (Local Area Network), Bluetooth® Low Energy (BLE), and NFC (Near Field Communication). BLE can be any communication method compatible with Bluetooth standard version 4.0 or later. The frequency band used for power transmission from the transmitting antenna 105 is different from the frequency band used by the second communication unit 109 for communication. The second communication unit 109 performs so-called out-of-band communication.

[0026] Regarding communication between TX100 and RX200, TX100 may selectively use one of several communication standards to communicate with RX200. For example, the following communication configurations using multiple communication standards selectively are possible: • Communication based on a first standard (WPC standard) between the first communication unit 104 of TX100 and the first communication unit 204 of RX200 (see Figure 3). • Communication based on a second standard (a standard other than the WPC standard) between the second communication unit 109 of TX100 and the second communication unit 212 of RX200 (see Figure 3).

[0027] The UI unit 110 is connected to the control unit 101 and provides various outputs to the user. These outputs include screen displays, blinking and color changes of LEDs (Light Emitting Diodes), audio output from the speaker, and vibration of the TX100 main unit. The UI unit 110 is implemented using an LCD panel, speaker, vibration motor, etc.

[0028] Next, an example of the configuration of the power receiving device 200 will be described with reference to Figure 3. Figure 3 is a functional block diagram showing an example of the configuration of the power receiving device 200. RX200 includes a control unit 201, a UI unit 202, a power receiving unit 203, a first communication unit 204, a power receiving antenna 205, a charging unit 206, a battery 207, and a memory 208. RX200 further includes a first switch unit 209, a second switch unit 210, a resonant capacitor 211, a second communication unit 212, and a third switch unit 213. In this embodiment, an example is shown where the functional block elements in Figure 3 are individual elements, but multiple functional block elements may be implemented as a single hardware module (for example, within the same chip).

[0029] The control unit 201 controls each functional block element of the RX200 by executing a control program stored in the memory 208. Furthermore, the control unit 201 can perform control for executing applications other than wireless power transmission. The control unit 201 is configured to include one or more processors such as a CPU or MPU. In addition, the control unit 201 can control the entire RX200 (for example, the entire smartphone) in cooperation with the OS (Operating System) it is running. Alternatively, the control unit 201 is configured to include hardware such as an ASIC, or array circuits such as an FPGA compiled to execute predetermined processes. The control unit 201 stores information that should be stored during the execution of various processes in the memory 208, and can also execute timing processes using a timer (not shown).

[0030] The UI unit 202 is connected to the control unit 201 and provides various outputs to the user. These outputs include screen displays, LED blinking and color changes, audio output from the speaker, and vibrations of the RX200 unit. The UI unit 202 is implemented using an LCD panel, speaker, vibration motor, etc.

[0031] The power receiving unit 203 receives AC power (AC voltage and AC current) generated by electromagnetic induction based on electromagnetic waves radiated from the TX100's transmitting antenna 105 via the power receiving antenna (power receiving coil) 205. The power receiving unit 203 then converts the AC power into DC power or AC power of a predetermined frequency and supplies power to the charging unit 206. The charging unit 206 charges the battery 207. The power receiving unit 203 includes a rectifier unit (rectifier, rectifier circuit) and a voltage control unit necessary for supplying power to the load in the RX200. The rectifier unit converts the AC voltage and AC current from the transmitting antenna, received via the power receiving antenna 205, into DC voltage and DC current. This DC voltage will be referred to as the rectifier unit output voltage below. This DC current will be referred to as the rectifier unit output current below. The voltage control unit converts the level of the DC voltage (rectifier unit output voltage) output by the rectifier unit to a predetermined level. The predetermined level is the DC voltage level at which the control unit 201 and the charging unit 206 can operate. The power receiving unit 203 supplies power for charging the battery 207 from the charging unit 206. The power receiving unit 203 is assumed to have the power supply capacity to output 15 watts (W) of power to the charging unit 206.

[0032] The first communication unit 204 communicates with the first communication unit 104 of the TX 100 for power receiving control based on the WPC standard. The first communication unit 204 is connected to the power receiving antenna 205 and the control unit 201. The first communication unit 204 demodulates the electromagnetic waves input from the power receiving antenna 205 and acquires information transmitted from the TX 100. The first communication unit 204 performs load modulation, amplitude modulation, or backscatter modulation on the input electromagnetic waves and superimposes a signal related to the information to be transmitted to the TX 100 onto the electromagnetic waves, thereby communicating with the TX 100.

[0033] Memory 208 stores information regarding the status of TX100 and RX200, in addition to the control program. Information regarding the status of RX200 is acquired by the control unit 201. Information regarding the status of TX100 is acquired by the control unit 101 of TX100 and can be received by the first communication unit 204 or the second communication unit 212, which will be described later.

[0034] The second communication unit 212 is connected to the control unit 201 and communicates with the TX100 using a standard different from the WPC standard. For example, the second communication unit 212 communicates with the TX100 using an antenna different from the receiving antenna 205. Examples of communication methods used by the second communication unit 212 include wireless LAN, BLE, NFC, etc. BLE can be any communication method compatible with Bluetooth standard version 4.0 or later. The frequency band used when receiving power with the receiving antenna 205 is different from the frequency band used by the second communication unit 212 for communication.

[0035] Regarding communication between TX100 and RX200, RX200 may selectively use one of several communication standards to communicate with TX100. For example, the following communication configurations using multiple communication standards selectively are possible: • Communication based on a first standard (WPC standard) between the first communication unit 104 of TX100 and the first communication unit 204 of RX200. • Communication based on a second standard (a standard other than the WPC standard) between the second communication unit 109 of TX100 and the second communication unit 212 of RX200.

[0036] The first switch unit 209 is located between the charging unit 206 and the battery 207 and is controlled by the control unit 201. The first switch unit 209 has the function of controlling whether or not to supply the power received by the power receiving unit 203 to the battery 207, and the function of controlling the magnitude of the load. When the first switch unit 209 is turned OFF and opened by the control unit 201, the power received by the power receiving unit 203 is not supplied to the battery 207. When the first switch unit 209 is turned ON and short-circuited by the control unit 201, the power received by the power receiving unit 203 is supplied to the battery 207.

[0037] In Figure 3, the first switch unit 209 is located between the charging unit 206 and the battery 207, but the first switch unit 209 may also be located between the power receiving unit 203 and the charging unit 206.

[0038] Alternatively, the first switch unit 209 may be positioned between the closed circuit formed by the receiving antenna 205, the resonant capacitor 211, and the second switch unit 210, and the receiving unit 203. In this case, the first switch unit 209 has the function of controlling whether or not to supply the power received by the receiving antenna 205 to the receiving unit 203.

[0039] Furthermore, although the first switch unit 209 is described as a single functional block element in the example of Figure 3, it is possible to realize the first switch unit 209 as part of the charging unit 206 or the power receiving unit 203. Moreover, this disclosure is not limited to a configuration in which the first switch unit 209 is inserted in series between the charging unit 206 and the battery 207; the first switch unit 209 may also be inserted in parallel between the charging unit 206 and the battery 207. In this case, when the first switch unit 209 is turned OFF and opened by the control unit 201, the power received by the power receiving unit 203 is supplied to the battery 207. When the first switch unit 209 is turned ON and short-circuited by the control unit 201, the power received by the power receiving unit 203 is not supplied to the battery 207.

[0040] On the input side of the power receiving unit 203, the second switch unit 210 is connected in parallel with the resonant capacitor 211. The resonant capacitor 211 is connected to the power receiving antenna 205 via the third switch unit 213. The second switch unit 210 and the third switch unit 213 are controlled by the control unit 201. The third switch unit 213 has the function of controlling whether or not to open the terminals of the power receiving antenna 205. When the control unit 201 turns the third switch unit 213 OFF, the terminals of the power receiving antenna 205 are open. When the control unit 201 turns the third switch unit 213 ON, the power receiving antenna 205 is connected to the power receiving unit 203 via the resonant capacitor 211.

[0041] When the control unit 201 turns on the third switch unit 213 and the second switch unit 210, causing a short circuit, the receiving antenna 205 and the resonant capacitor 211 form a series resonant circuit and resonate at a specific frequency fB. At this time, current flows through the closed circuit formed by the receiving antenna 205, the resonant capacitor 211, and the second switch unit 210, but no current flows to the receiving unit 203. On the other hand, when the second switch unit 210 is turned off and the circuit is opened, the power received by the receiving antenna 205 and the resonant capacitor 211 is supplied to the receiving unit 203. Note that this disclosure is not limited to the example in Figure 3, and the second switch unit 210 may be placed between the receiving antenna 205 and the resonant capacitor 211. When the third switch unit 213 is ON and the second switch unit 210 is ON, the terminals of the receiving antenna 205 are short-circuited. Furthermore, the third switch unit 213 may be positioned between the resonant capacitor 211 and the power receiving unit 203.

[0042] In this wireless charging system, TX100 and RX200 transmit wireless power between the transmitting antenna 105 and the receiving antenna 205 in accordance with the WPC standard. In the WPC standard, the level of load power agreed upon between RX200 and TX100 is defined by a value called Guaranteed Load Power (hereinafter referred to as "GP"). Load power is the power consumed by the load. For example, GP is the power value at which the output of RX200 to the load is guaranteed even if the coupling between the receiving antenna 205 and the transmitting antenna 105 weakens and the power transmission efficiency decreases due to a change in the relative positions of RX200 and TX100. In this specification, the coupling state between the transmitting antenna (transmitting coil) 105 and the receiving antenna (receiving coil) 205 may also be referred to as the coupling state between TX100 and RX200. The load of the RX200 is the charging unit 206, the battery 207, etc., and the value of GP corresponds to the power that is guaranteed to be output from the power receiving unit 203. Alternatively, the value of GP corresponds to the power that is guaranteed to be output from the rectifier unit of the power receiving unit 203. For example, let's assume that the value of GP is 5 (watts) and the positional relationship between the power receiving antenna 205 and the power transmitting antenna 105 changes. In this case, even if the power transmission efficiency decreases, the TX100 will perform power transmission control so that it can output 5 watts to the load of the RX200. Furthermore, GP is determined by negotiations between the TX100 and the RX200. Note that this disclosure is not limited to GP, and this embodiment can be applied to a configuration in which power transmission and reception are performed with power determined by negotiations between the TX100 and the RX200.

[0043] Furthermore, when transmitting power from TX100 to RX200, we consider the case where an object is present near TX100. In this case, the object is one that may affect the power transmission from TX100 to RX200 and is a different object (foreign object) from RX200. Electromagnetic waves for power transmission may affect the foreign object, potentially causing a temperature rise or destruction of the foreign object. In this disclosure, a foreign object is an object that is neither a part of the power receiving device and the product into which the power receiving device is incorporated, nor a part of the power transmitting device and the product into which the power transmitting device is incorporated, but which may generate heat when exposed to a power signal. Examples of foreign objects include paper clips and IC cards. Objects that are essential parts of the power receiving device and the product into which the power receiving device is incorporated, or the power transmitting device and the product into which the power transmitting device is incorporated, but which may unintentionally generate heat when exposed to the radio power transmitted by the power transmitting antenna, are not considered foreign objects.

[0044] The WPC standard specifies a method to suppress the temperature rise and damage of foreign objects by stopping power transmission when foreign objects are present. Specifically, the power transmission device 100 can detect the presence of foreign objects on the charging base 300. The Power Loss method is a method of detecting foreign objects by the difference between the power transmitted by TX100 and the power received by RX200. Alternatively, the Q-value measurement method is a method of detecting foreign objects by the change in the Quality Factor (also called Q-factor, quality coefficient, Q value, etc.) of the power transmission antenna 105 (power transmission coil) in TX100. Or, the Q-value measurement method is a method of detecting foreign objects by the change in the Quality Factor of the resonant circuit including the power transmission antenna 105 and the resonant capacitor 107 in TX100. In this disclosure, the Quality Factor of the power transmission antenna 105 and the Quality Factor of the resonant circuit including the power transmission antenna 105 and the resonant capacitor 107 are referred to as the Quality Factor relating to the power transmission antenna 105. However, the foreign objects detected by TX100 are not limited to objects present on the charging base 300. TX100 can detect foreign objects located in the vicinity of TX100. For example, TX100 can detect foreign objects located within the range of power transmission.

[0045] Referring to Figure 4, we will explain foreign object detection based on the Power Loss method specified in the WPC standard. In Figure 4, the horizontal axis represents the power transmitted by TX100, and the vertical axis represents the power received by RX200. On the graph line shown by the straight line segment 1002, point 1000 corresponds to the first power transmitted value Pt1 and the first power received value Pr1, and point 1001 corresponds to the second power transmitted value Pt2 and the second power received value Pr2. On the same graph line, point 1003 corresponds to the third power transmitted value Pt3 and the third power received value Pr3. The foreign object to be detected is a conductive metal piece, etc.

[0046] First, TX100 transmits power to RX200 at a first transmission power value Pt1, and RX200 receives power at a first reception power value Pr1. Hereafter, this state will be referred to as the Light Load state. Then, TX100 stores the first transmission power value Pt1 (for example, in memory 106). At this time, RX200 performs load control so that the power received is the minimum power. Alternatively, RX200 performs load control so that the power received is within a predetermined range or below a predetermined threshold. Here, in "power within a predetermined range" or "power below a predetermined threshold," "power" refers to power that is approximately 10% of the Reference Power value described later. Furthermore, RX200 may disconnect the load from the receiving antenna 205 so that the received power is not supplied to the load (charging unit 206, battery 207, etc. in Figure 3). Alternatively, RX200 may control the load so that a predetermined amount of power is supplied to the load. These can be achieved by controlling the first switch unit 209. Subsequently, RX200 notifies TX100 of the first received power value Pr1 by transmitting a signal related to the first received power value Pr1 to TX100. Upon receiving the signal related to the first received power value Pr1 from RX200, TX100 calculates the power loss between TX100 and RX200. The power loss at this time is Pt1 - Pr1 (= Plus1). TX100 can generate a calibration point (hereinafter abbreviated as CP) 1000 that shows the correspondence between Pt1 and Pr1.

[0047] Next, TX100 changes the transmitted power value to the second transmitted power value Pt2 and transmits power to RX200, and RX200 receives power at the second received power value Pr2. Hereafter, this state will be referred to as the Connected Load state (load connection state, maximum load state). Then, TX100 stores the second transmitted power value Pt2 (for example, in memory 106). At this time, RX200 performs load control so that the power received is the maximum power. Here, "maximum power" is a power value close to the Reference Power, which will be described later. Alternatively, RX200 performs load control so that the power received is within a predetermined range of power, or above a predetermined threshold. For example, RX200 connects the receiving antenna 205 to the load so that the received power is supplied to the load. These can be achieved by controlling the first switch unit 209. Next, RX200 notifies TX100 of the second power received value Pr2 by transmitting a signal related to the second power received value Pr2 to TX100. Upon receiving the signal related to the second power received value Pr2 from RX200, TX100 calculates the power loss between TX100 and RX200. The power loss at this time is Pt2 - Pr2 (= Plus2). TX100 can then generate CP1001, which shows the correspondence between Pt2 and Pr2.

[0048] TX100 performs linear interpolation between CP1000 and CP1001 to generate line segment 1002. Line segment 1002 shows the relationship between transmitted power and received power in a state in which no foreign objects are detected to be present in the vicinity of TX100 and RX200 (hereinafter referred to as the first detection state). Based on line segment 1002, TX100 can estimate the power value that RX200 will receive when power is transmitted at a predetermined transmitted power in the first detection state. For example, consider the case where TX100 transmits power at a third transmitted power value Pt3. In this case, TX100 can estimate the third received power value Pr3 that RX200 will receive from point 1003 on line segment 1002, which corresponds to Pt3.

[0049] As described above, based on multiple combinations of the transmitted power value of TX100 and the received power value of RX200 measured while varying the load, the power loss between TX100 and RX200 according to the load can be determined. Furthermore, by interpolation processing from multiple combinations of transmitted power value and received power value, the power loss between TX100 and RX200 for all loads can be estimated. Thus, the calibration process performed by TX100 and RX200 to obtain the combination of transmitted power value and received power value is called the "Power Loss Calibration Process". The Calibration Process is also abbreviated as CAL. In addition, performing the Calibration Process again after it has been executed once to update or add calibration points is called the Recalibration Process, and is abbreviated as ReCAL.

[0050] Let's assume that after CAL processing using the Power Loss method, TX100 actually transmits power to RX200 with the third transmission power value Pt3, and TX100 receives a signal from RX200 regarding the received power value Pr3* (is notified of the received power value Pr3*). This signal regarding the received power value Pr3* is the Received Power data package (mode0) as defined in the WPC standard, but other messages may be used. Hereafter, Received Power data package (mode0) will be referred to as RP0. RP0 contains the value of the received power value Pr3*. TX100 calculates Pr3 - Pr3* (= Plus_FO) by subtracting the actual received power value Pr3* notified by RX200 from the received power value Pr3 in the first detection state. Plus_FO can be estimated to be the power consumed by foreign objects, i.e., power loss, if foreign objects are present in the vicinity of TX100 and RX200. Hereinafter, the state in which foreign objects are detected to be present in the vicinity of TX100 and RX200 will be referred to as the second detection state.

[0051] In the second detection state, TX100 compares the power loss Plus_FO, which is likely to have been consumed by the foreign object, with a predetermined threshold. If the value of the power loss Plus_FO exceeds the threshold, TX100 can determine that a foreign object is present. Alternatively, TX100 obtains the third power received value Pr3 in the first detection state from RX200 and pre-calculates the power loss Pt3-Pr3 (=Plus3) between TX100 and RX200.

[0052] Next, TX100 obtains the power received value Pr3* from RX200 in the second detection state and calculates the power loss Pt3 - Pr3* (= Plus3*) between TX100 and RX200 in the second detection state. Then, TX100 can estimate the power loss Plus_FO using Plus3* - Plus3.

[0053] As described above, there are two methods for calculating Plus_FO in the second detection state: • The first method calculates Plus_FO from Pr3 - Pr3*. • The second method calculates Plus_FO from Plus3* - Plus3.

[0054] This embodiment primarily describes the second method, but the contents of this embodiment can also be applied to the first method.

[0055] Next, with reference to Figures 5A and 5B, we will explain foreign object detection based on the Q-value measurement method specified in the WPC standard. Figure 5A is a schematic circuit diagram for explaining the measurement method of Quality Factor by the Q-value measurement method. The AC power supply 901 corresponds to the power supply that outputs AC power generated by the power transmission unit 103 of TX100. The power transmission antenna 902 corresponds to the power transmission antenna 105, and the capacitor 903 corresponds to the resonant capacitor 107. The power transmission antenna 902 and the capacitor 903 are connected in series. The voltage value V8 is a voltage value of a predetermined frequency generated by the power transmission unit 103 to operate the wireless power transmission system (wireless charging system). The voltage value V9 is the voltage value applied to the power transmission antenna 902. Here, it is assumed that TX100 can change the frequency related to the voltage value. Furthermore, voltage values ​​V8 and V9 are the voltage values ​​measured by TX100 when TX100 transmits Analog Ping (hereinafter referred to as "AP") or Digital Ping (hereinafter referred to as "DP") to RX200. Note that since voltage values ​​V8 and V9 are AC voltage values, their RMS values ​​may also be used.

[0056] Figure 5B shows an example of the measurement results of V9 / V8 against frequency, with a peak at 100 kHz. The horizontal axis is the frequency axis, and the vertical axis represents the voltage ratio "V9 / V8". Since V9 / V8 represents the Quality Factor related to the power transmission antenna 902, its value changes when an object is placed near the power transmission antenna 902. The change in Quality Factor differs depending on whether an object is placed on TX100, whether RX200 is placed on TX100, whether foreign matter (metal fragments, etc.) is placed on TX100, and whether RX200 and foreign matter are placed on TX100.

[0057] In the Negotiation phase, as defined in the WPC standard and described later, TX100 receives a signal of the FOD Status data packet from RX200. The FOD Status data packet includes the Reference Quality Factor Value and the Reference Resonance Frequency Value. The Reference Quality Factor Value is the Quality Factor that can be measured at the terminal of the power transmission antenna of the test TX100 when RX200 is mounted on the test TX100 and no foreign objects are nearby. Furthermore, the Reference Resonance Frequency Value is as follows: It is the resonant frequency calculated from the inductance value that can be measured at the terminal of the power transmission antenna of the test TX100 when the RX200 is mounted on the test TX100 and no foreign objects are nearby. In the Q-value measurement method, a threshold is set based on the Reference Quality Factor Value. Foreign object detection is performed by comparing this threshold with the Quality Factor obtained from the actually measured V9 / V8. Alternatively, a threshold is set based on the Reference Resonance Frequency Value. Foreign object detection is performed by comparing this threshold with the resonant frequency (Resonance Frequency) obtained by actually measuring V9 / V8.

[0058] In this embodiment, RX200 and TX100 communicate for power transmission and reception control based on the WPC standard. The WPC standard defines multiple phases, including the Power Transfer phase in which power transmission is performed and one or more phases prior to actual power transmission. Communication for necessary power transmission and reception control is performed in each phase. For example, foreign object detection using the Power Loss method is performed in the Power Transfer phase based on data obtained in the Calibration phase. Foreign object detection using the Q-value measurement method is performed before power transmission (before Digital Ping transmission and in the Negotiation phase or Renegotiation phase).

[0059] The WPC standard includes the Selection phase, Ping phase, and Configuration phase before power transmission. In addition, there are the Negotiation phase and Calibration phase. The processing of each phase is described below.

[0060] During the Selection phase, the TX100 intermittently transmits Analog Pings to detect when an object is placed on the charging base of the TX100. Analog Ping is a short-duration power signal applied to detect the presence of an object. However, this power signal does not activate the control unit of the power receiving device. For example, it detects when an RX200 or a conductive piece is placed on the charging base. The TX100 detects either or both the voltage and / or current values ​​of the transmitting antenna 105 when the Analog Ping is transmitted. If the voltage value falls below a threshold or the current value exceeds a threshold, the TX100 determines that an object is present and transitions to the Ping phase. Alternatively, TX100 determines that an object exists and transitions to the Ping phase if the Quality Factor obtained from the voltage value satisfies predetermined conditions, or if the Quality Factor obtained from the current value satisfies predetermined conditions.

[0061] In the Ping phase, TX100 transmits a Digital Ping with higher power than Analog Ping. The Digital Ping is a power signal to activate the control unit of RX200, which is mounted on top of TX100. RX200 notifies TX100 of the received voltage value. In this way, TX100 recognizes that the object detected in the Selection phase is RX200 by receiving a response from RX200 that has received the Digital Ping. Upon receiving notification of the received voltage value from RX200, TX100 transitions to the Configuration phase. Also, before transmitting the Digital Ping, TX100 measures the Quality Factor related to the power transmitting antenna 105, for example, using Analog Ping. These measurement results are used when performing foreign object detection processing using the Q-value measurement method. Note that, depending on the version of the WPC standard, the Selection phase described above may be included as part of the Ping phase and referred to simply as the Ping phase.

[0062] During the Configuration phase, TX100 identifies RX200 and obtains equipment configuration information (capability information) from RX200. RX200 transmits signals for ID data pack and Configuration data pack. The ID data pack contains identifier information for RX200, and the Configuration data pack contains equipment configuration information (capability information) for RX200. Upon receiving the ID data pack and Configuration data pack signals, TX100 responds with an acknowledgment (ACK). The Configuration phase then ends.

[0063] In the negotiation phase, the GP value is determined based on the GP value requested by RX200 and the power transmission capacity of TX100. TX100 also receives an FOD Status data package from RX200 containing the Reference Quality Factor Value and Reference Resonance Frequency Value. In the Q-value measurement method, the presence or absence of foreign matter is determined based on thresholds using the Reference Quality Factor Value and Reference Resonance Frequency Value as references. TX100 executes foreign matter detection processing using the Q-value measurement method in accordance with the request from RX200. Furthermore, the WPC standard specifies a method in which, after transitioning to the Power Transfer phase, the same processing as the Negotiation phase is performed again at the request of the RX200. The phase in which these processes are performed after transitioning from the Power Transfer phase is called the Renegotiation phase.

[0064] In the Calibration phase, a Power Loss Calibration process (hereinafter referred to as "Power Loss CAL process") is performed based on the WPC standard. The RX200 also notifies the TX100 of a predetermined power received value, and the TX100 makes adjustments to efficiently transmit power. The predetermined power received value is, for example, the power received in a light load state or a connected load state. The power received value notified to the TX100 is used for foreign object detection processing using the Power Loss method.

[0065] In the Power Transfer phase, TX100 and RX200 perform control for starting and continuing power transmission, error handling, and stopping power transmission upon full charge. TX100 and RX200 perform communication processing for these power transmission and reception control operations. For example, using the transmitting antenna 105 and receiving antenna 205 used for wireless power transmission based on the WPC standard, communication is performed by superimposing a signal onto the electromagnetic waves transmitted from the transmitting antenna 105 or the receiving antenna 205. The range in which communication based on the WPC standard is possible between TX100 and RX200 is the same as the power transmission range of TX100. Depending on the version of the WPC standard, the Calibration phase described above may also be referred to as the Power Transfer phase as part of the Power Transfer phase.

[0066] Next, the functions of the control unit of TX100 will be described with reference to Figure 6. Figure 6 is a block diagram showing an example of the functional configuration of the control unit 101 of the power transmission device 100 (TX100). The control unit 101 includes a communication control unit 301, a power transmission control unit 302, a measurement unit 303, a setting unit 304, and a state detection unit 305.

[0067] The communication control unit 301 performs communication control with the RX200 based on the WPC standard via the first communication unit 104, or performs communication control with the RX200 via the second communication unit 109.

[0068] The power transmission control unit 302 controls the power transmission unit 103 to control the power transmission to the RX200.

[0069] The measurement unit 303 measures the power transmitted to the RX200 via the power transmission unit 103 and measures the average transmitted power per unit time. The measurement unit 303 also measures the Quality Factor related to the power transmission antenna 105. The measurement unit 303 also measures the temperature using temperature sensors placed at multiple locations on the TX100. The measurement unit 303 also measures a quantity (e.g., coupling coefficient) that represents the electromagnetic coupling state between the power transmission antenna 105 and the power receiving antenna 205. The quantity representing the electromagnetic coupling state, such as the coupling coefficient, may also be called a coupling state index. In this specification, measuring the coupling state index and correcting the coupling state index (by correcting the coupling coefficient as described later) to obtain the corrected coupling state index may be considered as calculating or determining the coupling state between the power transmission antenna 105 and the power receiving antenna 205.

[0070] The setting unit 304 calculates and sets the threshold for foreign object detection in the Q-value measurement method and the threshold for foreign object detection in the Power Loss method using the method described above. The setting unit 304 also calculates and sets the threshold for foreign object detection or the threshold for detecting misalignment between TX100 and RX200 based on, for example, the coupling state index between the transmitting antenna 105 and the receiving antenna 205 measured by the measurement unit 303. The setting unit 304 also calculates and sets the threshold for foreign object detection or the threshold for detecting misalignment between TX100 and RX200 based on, for example, the temperature of the power transmission device measured by the measurement unit 303.

[0071] The state detection unit 305 performs state detection between the TX100 and the RX200. For example, the state detection unit 305 detects foreign objects present between the TX100 and the RX200, and also detects misalignment between the transmitting antenna 105 and the receiving antenna 205. More specifically, state detection processing can be performed using the Power Loss method, Q-value measurement method, temperature measured in the TX100, and the electromagnetic coupling state (e.g., coupling coefficient) between the transmitting antenna 105 and the receiving antenna 205. The state detection unit 305 can also perform foreign object detection and misalignment detection between the transmitting antenna 105 and the receiving antenna 205 using other methods. For example, in a TX100 equipped with NFC communication functionality, the state detection unit 305 performs state detection processing using the opposing device detection function according to the NFC standard. In addition to detecting the presence or absence of foreign objects and the electromagnetic coupling state between the transmitting and receiving antennas, the state detection unit 305 can also detect changes in the state of the TX100. For example, the state detection unit 305 can detect an increase or decrease in the number of RX200s on the TX100.

[0072] The setting unit 304 sets a threshold value that serves as a criterion for determining the presence or absence of foreign matter when the TX 100 performs state detection. State detection can be, for example, based on the Power Loss method, Q-value measurement method, state detection based on the temperature measured in the TX 100, or state detection based on the coupling state index of the transmitting antenna 105 and the receiving antenna 205. The setting unit 304 can also set a threshold value for determination necessary for state detection processing using other methods. Based on the threshold value set by the setting unit 304 and the measurement results from the measurement unit 303, the state detection unit 305 can perform foreign matter detection processing and positional misalignment detection processing between the transmitting antenna 105 and the receiving antenna 205. For example, the state detection unit 305 can acquire data such as transmitted power, Quality Factor, temperature measured in the TX 100, and coupling coefficient between the transmitting antenna 105 and the receiving antenna 205 as measurement results from the measurement unit 303.

[0073] The processes performed by the communication control unit 301, power transmission control unit 302, measurement unit 303, setting unit 304, and state detection unit 305 shown in Figure 6 can be implemented using programs executed by the CPU or other components of the control unit 101. Each process is executed in parallel according to its own independent program, while maintaining synchronization between programs through event processing or the like. However, two or more of these processes may be incorporated into a single program.

[0074] Next, an example of the processing flow related to power transmission and reception control performed by TX100 and RX200 will be described. Figure 7 is a flowchart showing an example of power transmission control processing performed by TX100. This processing is realized, for example, by the control unit 101 of TX100 executing a program read from memory 106. This processing may also be performed in response to the power being turned on to TX100, in response to the user of TX100 inputting a command to start a wireless power transmission application, or in response to TX100 being connected to a commercial power source and receiving power. This processing may also be started by other triggers.

[0075] In S1201, TX100 performs the processes defined as the Selection phase and Ping phase of the WPC standard and waits for RX200 to be placed. Specifically, TX100 repeatedly and intermittently transmits Analog Ping according to the WPC standard to detect objects within the power transmission range. For example, TX100 can detect when RX200 or conductive pieces are placed on the charging base 300. If TX100 detects the presence of an object within the power transmission range, it transmits Digital Ping.

[0076] When TX100 receives a predetermined response to Digital Ping, it determines that the detected object is RX200 and that RX200 has been placed on the charging base 300. Here, the "predetermined response" is the Signal Strength (SIG) data packet transmitted by RX200. This packet includes a Signal Strength Value representing the signal strength of the signal received by RX200. The Signal Strength Value is calculated from the following parameters. Specifically, the parameters are the voltage output by the rectifier of the power receiving unit 203 measured by RX200 (rectifier output voltage), or the voltage of the open circuit including the power receiving antenna 205 measured by RX200 (open circuit voltage), or the power received value measured by RX200, etc.

[0077] Furthermore, before transmitting the Digital Ping, the TX100 measures the Quality Factor related to the transmitting antenna 105. This measurement result is used when performing foreign object detection processing using the Q-value measurement method.

[0078] After the placement of the RX200 is detected, in S1202, the TX100 obtains (receives) identification information from the RX200 through communication in the Configuration phase as defined by the WPC standard. In the Configuration phase, the RX200 transmits an Identification data packet (ID Packet) to the TX100. The ID Packet contains the Manufacturer Code and Basic Device ID, which are the identification information for each individual RX200, as well as information elements that can identify the version of the corresponding WPC standard.

[0079] Furthermore, the RX200 transmits a Configuration data package to the TX100. The Configuration data package contains the following capability information for the RX200: • Maximum Power Value or Reference Power, which is a value that identifies the maximum power that the RX200 can supply to the load. • Information indicating whether the RX200 has WPC standard Negotiation functionality. • Parameters used in frequency shift modulation, the communication modulation method used by the TX100 when transmitting information to the RX200. • Information indicating whether the RX200 supports out-of-band communication functionality.

[0080] When TX100 receives the packet from RX200, it sends an acknowledgment (ACK) to RX200, and the Configuration phase ends. Note that TX100 may obtain the identification information of RX200 by a method other than the WPC standard Configuration phase communication. The identification information for each RX200 may be a Wireless Power ID. Alternatively, it may be any other identification information that can identify an individual RX200, such as a Bluetooth Address (hereinafter referred to as "BD_ADDR") unique to the second communication unit 212 of RX200. Note that BD_ADDR is an 8-byte address used in BLE. BD_ADDR is a Public Address defined in the BLE standard, which indicates, for example, the manufacturer of the RX200 or individual identification information of the BLE's communication function (second communication unit 212). BD_ADDR may also be a Random Address.

[0081] Subsequently, in S1203, TX100 determines GP through negotiation with RX200 based on the request from RX200 and its own power transmission capability. In S1203, communication in the Negotiation phase of the WPC standard is performed. For example, RX200 notifies the requested power value by transmitting a Specific Request to TX100. TX100 determines whether to accept the request based on its own power transmission capability and other conditions. When TX100 accepts the request, it transmits an affirmative response ACK to RX200, and when it does not accept the request, it transmits a negative response NACK or NAK to RX200. The value of GP determined through negotiation with RX200 becomes the value requested by RX200 when TX100 accepts the request from RX200. When TX100 does not accept the request from RX200, the GP value may be, for example, a predetermined value (e.g., 5 watts) defined in the WPC standard. Also, when TX100 acquires information indicating that RX200 does not correspond to the Negotiation phase (e.g., S1302 described later), it does not perform communication in the Negotiation phase and determines the GP value to be a predetermined value. The predetermined value is, for example, a value (e.g., 5 watts) predefined in the WPC standard.

[0082] In addition, TX100 executes foreign object detection processing using the Q-value measurement method according to the request from RX200. TX100 receives a FOD Status data packet from RX200. This packet includes the above-described Reference Quality Factor Value and Reference Resonance Frequency Value. Then, TX100 performs foreign object detection using the Q-value measurement method. This foreign object detection is performed based on the following information: - The Quality Factor and resonance frequency of the power transmission antenna 105 measured by TX100 before transmitting Digital Ping. - Thresholds based on the Reference Quality Factor Value and Reference Resonance Frequency Value received by TX100 from RX200.

[0083] Next, in S1204, TX100 and RX200 perform the Calibration phase processing (CAL processing) of the WPC standard. In the Calibration phase, TX100 performs CAL processing of the Power Loss method based on the determined Reference Power value or GP value. First, RX200 transmits a signal to TX100 containing information about the received power under light load conditions (hereinafter referred to as the first reference received power information). Light load conditions are, for example, a load disconnection state, a load condition in which the received power value of RX200 is below a first threshold, or a load condition in which the received power value of RX200 is within a predetermined range (hereinafter referred to as the "first range"). In this embodiment, the first reference received power information is assumed to be 500 milliwatts (however, the first reference received power information is not limited to 500 milliwatts). The first reference power information is the information contained in the Received Power data package (mode 1) as defined in the WPC standard, but other messages may be used. Hereinafter, the Received Power data package (mode 1) will be referred to as RP1. TX100 determines whether to accept the first reference power information based on the Control Error Value contained in the Control Error (CE) data package received from RX200. If TX100 accepts the first reference power information, it sends an affirmative response ACK to RX200. If TX100 does not accept the first reference power information, it sends a negative response NAK to RX200.

[0084] Next, RX200 performs processing to transmit a signal to TX100 containing information about the power received in a load-connected state (hereinafter referred to as the second reference power received information). The load-connected state is, for example, the maximum load state, the load state in which the transmitted power value is equal to or greater than the second threshold, or the load state in which the power received by RX200 is the maximum power. Here, "maximum power" is the power value close to the Reference Power. Alternatively, the load-connected state is the load state in which the power received by RX200 falls within a predetermined range (hereinafter referred to as the "second range"). Here, the second range is a range of power values ​​higher than the first range. In this embodiment, the second reference power received information is set to 15 watts (however, the second reference power received information is not limited to 15 watts). The second reference power information is the information contained in the Received Power data package (mode 2) as defined in the WPC standard, but other messages may be used. Hereinafter, the Received Power data package (mode 2) will be referred to as RP2. TX100 determines whether to accept the second reference power information based on the Control Error Value contained in the Control Error (CE) data package received from RX200. If TX100 accepts the second reference power information, it sends an affirmative response ACK to RX200. If TX100 does not accept the second reference power information, it sends a negative response NAK to RX200. TX100 sends an acknowledgment (ACK) to the second reference power information from RX200 and completes the CAL process.

[0085] Through the above CAL process, TX100 can calculate the power loss amount between TX100 and RX200 in the light load state and the load connection state based on the power transmission power value of TX100 and the received power values included in the first and second reference received power information. Further, TX100 can calculate the power loss amount between TX100 and RX200 at all power transmission powers that TX100 can obtain by performing interpolation processing between a plurality of power loss amounts. All the power transmission powers that TX100 can obtain are, for example, arbitrary powers within the range where the received power received by RX200 in the present embodiment ranges from 500 milliwatts to 15 watts. Note that the above-described CAL process may not be performed.

[0086] Then, in S1205, TX100 performs power transmission until the battery 207 of RX200 is fully charged. In S1205, communication in the Power Transfer phase of the WPC standard is performed. RX200 repeatedly transmits a Control Error data packet (hereinafter referred to as a "CE packet") to TX100 at a time interval of t_interval. t_interval is a value defined by the WPC standard and is, for example, 250 milliseconds. The CE packet includes a request for how much to increase or decrease the power transmission power. TX100 adjusts the power transmission power by controlling the current or voltage of the power transmission antenna 105 based on the received CE packet. That is, the CE packet includes data of parameters for adjusting the power transmission power. By repeating this process, power transmission at an appropriate power according to the request of RX200 is performed almost in real time.

[0087] When the battery 207 is fully charged, RX200 transmits an End Power Transfer data packet (hereinafter referred to as an "EPT packet") to end the Power Transfer phase. RX200 can transmit an EPT packet for reasons other than full charge. Also, when the Power Transfer phase ends, TX100 stops power transmission for charging RX200.

[0088] Furthermore, if TX100 fails to receive the next CE packet after a time t_timeout has elapsed since the last CE packet was received, it determines that RX200 has been removed from the charging cradle 300. In this case, TX100 terminates the Power Transfer phase. t_timeout is a value defined by the WPC standard, for example, 1500 milliseconds.

[0089] RX200 may send packets other than CE packets to TX100 during the Power Transfer phase. For example, there is a Charge Status data packet that notifies TX100 of the status of RX200's battery 207. This packet contains a Charge Status Value indicating the percentage of charge of the battery 207. When TX100 receives the Charge Status data packet, it notifies the user of the charging status by displaying text or diagrams based on the Charge Status Value, for example, using the UI unit 110. TX100 may receive the Charge Status data packet at any time and may notify the user at any time it chooses.

[0090] During the Power Transfer phase, TX100 transmits power to RX200 and performs foreign object detection processing using the Power Loss method. For example, CAL processing calculates the amount of power loss between TX100 and RX200 in the first detection state during power transmission from the difference between the transmitted power value and the received power value. The calculated amount of power loss corresponds to the standard amount of power loss in the absence of foreign objects. Then, if TX100 determines that the difference between the amount of power loss between TX100 and RX200 measured during power transmission after CAL processing and the standard amount of power loss is greater than or equal to a threshold, it determines that a second detection state has been reached.

[0091] Referring to Figure 8, an example of the processing flow related to power reception control performed by RX200 will be explained. This processing is realized, for example, by the control unit 201 of RX200 executing a program read from memory 208.

[0092] In S1301, RX200 performs the processes defined as the Selection phase and Ping phase of the WPC standard and waits for its device to be placed on TX100. RX200 detects that it has been placed on TX100, for example, by detecting a Digital Ping from TX100.

[0093] When RX200 detects that it has been placed on TX100, in S1302 it transmits a signal containing its identification information to TX100 using the ID Packet and Configuration data pack. Note that the identification information of RX200 may be transmitted by a method other than the communication in the Configuration phase of the WPC standard. In addition, other identification information such as BD_ADDR may be used as long as it is information that can identify each individual RX200. Furthermore, in S1302, RX200 can transmit information other than identification information to TX100.

[0094] Next, in S1303, RX200 transmits a signal to TX100 containing information about the power values ​​it requests, and negotiates with TX100 to determine the GP. In S1303, the Negotiation phase of the WPC standard communication takes place. RX200 transmits an FOD Status data packet to TX100. This packet includes Reference Quality Factor Value and Reference Resonance Frequency Value.

[0095] Next, in S1304, RX200 and TX100 perform the Calibration phase processing (CAL processing) of the WPC standard. The processing performed by RX200 in this phase is as described above. Note that the CAL processing described above is optional.

[0096] Subsequently, in S1305, RX200 receives power until the battery 207 is fully charged. The processing performed by RX200 in this phase is as described above. In the Power Transfer phase, RX200 and TX100 perform foreign object detection processing using the Power Loss method. In S1305, RX200 repeatedly transmits CE packets at intervals of t_interval, and finally transmits an EPT packet to TX100 to terminate processing.

[0097] Next, we will explain the measurement method for the coupling state index between the transmitting and receiving antennas in the MPP (Magnetic Power Profile) of the Qi standard. MPP is adopted in the "Qi2 (Qi standard v2.0)" standard of the wireless power receiving standard "Qi". In the WPC standard, there are BPP (Baseline Power Profile) which transmits 5 watts or less of power to the RX200, EPP (Extended Power Profile) which transmits 15 watts or less of power, and the aforementioned MPP. Here, a power profile is a set of features that defines the compliance level of the transmitting or receiving device. MPP has the function of fixing TX100 and RX200 in predetermined positions with high precision. Multiple means can be considered for fixing TX100 and RX200 in predetermined positions with high precision. For example, the transmitting antenna (transmitting coil) of TX100 and the receiving antenna (receiving coil) of RX200 can be precisely opposed (facing directly) by using the magnets built into TX100 and RX200, respectively. In other words, in this case, MPP can be said to be an extended function of BPP, a profile (power profile) that uses magnets to align the power transmitting and receiving devices. The magnets may be permanent magnets or electromagnets.

[0098] TX100 represents the coupling state (inductive coupling factor) between TX100 and RX200. ｅｓｔ k is calculated (estimated or estimated) using the following formula. ｅｓｔrepresents the coupling state (inductive coupling coefficient) between the power transmission coil of TX100 and the power reception coil of RX200. k ｅｓｔ = E ０ｘｇ α ０ｒｘ ​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​In other words, E ０ｇｇ and E １ｇｇ These are characteristic coefficients that represent the characteristics when the reference power transmission device and the reference power reception device are placed opposite each other. These characteristic coefficients are calculated in advance by measurement, and their values ​​are stored in memory 208 by RX200.

[0108] Also, E ０ｘｇ and E １ｘｇ These are characteristic coefficients that represent the characteristics when the reference power receiving device and the power transmitting device to be actually used are placed opposite each other. These characteristic coefficients are calculated in advance by measurement, and their values ​​are stored in memory 106 by TX100.

[0109] Also, E ０ｇｙ and E １ｇｙ These are characteristic coefficients that represent the characteristics when the reference power transmission device and the power receiving device to be actually used are placed opposite each other. These characteristic coefficients are calculated in advance by measurement, and their values ​​are stored in memory 208 by RX200.

[0110] Figure 9A is a diagram illustrating the power transmission antenna and power transmission device enclosure. The power transmission device enclosure (housing) encloses the power transmission antenna (power transmission coil). In this specification, as shown in Figure 9A, the distance from the bottom surface of the power transmission antenna (power transmission coil) to the surface (top surface, bottom surface) of the power transmission device enclosure, which is the Interface surface, is defined as dZ. ＰＴＸ This is defined as follows. Therefore, dZ ＰＴＸ This can be described as the distance between the power transmission antenna (power transmission coil) and the power transmission equipment enclosure.

[0111] Figure 9B is a diagram illustrating the receiving antenna and the receiving device enclosure. The receiving device enclosure (casing) contains the receiving antenna (receiving coil). In this specification, as shown in Figure 9B, the distance from the bottom surface of the receiving antenna (receiving coil) to the surface (top and bottom surface) of the receiving device enclosure, which is the Interface surface, is defined as dZ. ＰＲＸ This is defined as follows. Therefore, dZ ＰＲＸIt can be said to be the distance between the power receiving antenna (power receiving coil) and the power receiving device enclosure.

[0112] In the Qi standard, dZ of the reference power transmission device of MPP ＰＴＸ is 1.2 mm which is the nominal value (Nominal Value). Also, in the Qi standard, dZ of the reference power receiving device of MPP ＰＲＸ is 0.66 mm which is the nominal value.

[0113] Also, V ｒｅｃｔ is the output voltage after being rectified in the rectifier circuit of RX200 when RX200 receives Digital Ping. RX200 ｒｅｃｔ transmits information regarding the measured value (information indicating the measured value) to TX100 after measuring V.

[0114]

[0115] is the peak-to-peak voltage of the resonant capacitor 107 measured by TX100.

[0116] Also, V ｉｎ is the DC voltage input to the inverter of TX100 measured by TX100, or the voltage output by the inverter of TX100 measured by TX100.

[0117] α ０ｒｘ is calculated by RX200 from E ０ｇｙ and E ０ｇｇ held in the memory 208 of RX200. α １ｒｘ is calculated by RX200 from E １ｇｙ and E １ｇｇ held in the memory 208 of RX200. RX200 ０ｒｘ and α １ｒｘ holds α in the memory 208 and transmits information regarding these values (information indicating these values) to TX100. α ０ｒｘ and α １ｒｘ are the ecosystem scaling coefficient (Ecosystem scaling coefficient) or the scaling factor.

[0118] E ０ｘｇ and E １ｘｇ This is pre-stored in memory 106 by TX100.

[0119] TX100 receives V from RX200 ｒｅｃｔ Information regarding α ０ｒｘ Information regarding and α １ｒｘ Information regarding the measurements of the TX100

[0120]

[0121] and V ｉｎ And, the E that TX100 has in advance ０ｘｇ and E １ｘｇ And then, k ｅｓｔ Calculate (estimate or estimate) the following.

[0122] As described above, the TX100 is the V measured by the RX200. ｒｅｃｔ The TX100 measured the following:

[0123]

[0124] and V ｉｎ By correcting the p calculated from the above using the eigenfactors and scaling factors, the k representing the coupling state (coupling coefficient) between TX100 and RX200 can be obtained. ｅｓｔ Calculate.

[0125] In the current Qi standard MPP, the TX100's dZ ＰＴＸ This assumes an equivalent of 1.2 mm, and the aforementioned eigenfactors, scaling factor, and k ｅｓｔ The calculation method is also designed under that premise. Therefore, the dZ of the TX100 ＰＴＸ If the distance differs from 1.2 mm by a certain amount or more, the premise is broken, so k ｅｓｔ This could potentially make it impossible to calculate accurately.

[0126] Therefore, below, the dZ of the TX100 ＰＴＸ When the distance differs from 1.2 mm by a certain amount or more, k ｅｓｔ A method for accurately calculating this will be explained using Figures 10 and 11.

[0127] Figure 10 is a flowchart showing an example of processing by TX100 according to the first embodiment. Figure 11 is a flowchart showing an example of processing by RX200 according to the first embodiment.

[0128] First, the RX200 is mounted on the TX100 (F1001, F1101). Then, the TX100 and RX200 perform the Ping phase processing described above (F1002, F1102).

[0129] Next, the RX200 is the TX100's dZ ＰＴＸ A request to send a packet containing information about the above is sent to TX100 (F1103).

[0130] The TX100 is a successor to the RX200, and the TX100 is a successor to the dZ ＰＴＸ When a request to send a packet containing information is received (Yes in F1003), proceed to F1004. TX100 receives a packet from RX200, and the TX100's dZ ＰＴＸ If a packet transmission request containing information is not received (No in F1003), the process returns to F1003. In F1004, TX100's dZ ＰＴＸ Send a packet containing information about the above to RX200.

[0131] Here, the dZ ＰＴＸ Information regarding dZ ＰＴＸ This is information indicating the distance.

[0132] For example, dZ ＰＴＸ The information indicating the distance is dZ ＰＴＸ The distance is such that it is a specific dZ, such as "2.5 mm" or "3.0 mm". ＰＴＸ This is information indicating the distance.

[0133] Alternatively, dZ ＰＴＸ The information indicating the distance is one of several predetermined distances, dZ ＰＴＸThis is information indicating the corresponding distance. For example, let's assume that distances of "2.5 mm", "3.0 mm", and "3.5 mm" are predetermined. Also, let's assume that TX100 transmits information "1" to RX200 when the distance is "2.5 mm", information "2" when the distance is "3.0 mm", and information "3" when the distance is "3.5 mm". And, for example, dZ ＰＴＸ If the value is "3.0 mm", the TX100 transmits the information "2" to the RX200.

[0134] Alternatively, dZ ＰＴＸ The information indicating the distance is the dZ ＰＴＸ This information indicates whether the value is below a predetermined threshold or within a predetermined range. For example, TX100 is dZ for RX200. ＰＴＸ If it is 3.0 mm or more, send the information "1", dZ ＰＴＸ If it is less than 3.0 mm, it sends the information "0". Alternatively, for example, TX100 sends dZ to RX200. ＰＴＸ If the value is "1.5 mm or more but less than 2.0 mm", it sends the information "1". Also, for example, TX100 sends dZ to RX200. ＰＴＸ If the value is "2.0 mm or more but less than 2.5 mm", it sends the information "2". Also, for example, TX100 sends dZ to RX200. ＰＴＸ If the value is "2.5 mm or more but less than 3.0 mm", then send the information "3".

[0135] The RX200 is a successor to the TX100, and the dZ ＰＴＸ It determines whether or not a packet containing information about dZ has been received (F1104). RX200 receives from TX100, ＰＴＸ If a packet containing information related to is received (Yes in F1104), proceed to F1105. RX200 receives information from TX100, dZ ＰＴＸ If no packet containing information is received (F1104 shows No), the system returns to F1104.

[0136] In F1105, the RX200 is dZ ＰＴＸ Information regarding (i.e., dZ) ＰＴＸSelect a characteristic coefficient (information for calculating or determining the coupling state) related to the coupling state calculation according to ( ). Hereinafter, a method for selecting the characteristic coefficient of RX200 will be described.

[0137] The "dZ ＰＴＸ related characteristic coefficient for coupling state calculation selected by RX200 is E ０ｇｙ , E ０ｇｇ , E １ｇｙ and E １ｇｇ (therefore, scaling factors α ０ｒｘ and α １ｒｘ ). That is, the characteristic coefficient in which {b} in the above-described E{a}{b}{c} is g (reference power transmission device) is the "dZ ＰＴＸ related characteristic coefficient for coupling state calculation" selected by RX200. In the present embodiment, the dZ ＰＴＸ of TX100 is different from the dZ ＰＴＸ = 1.2 mm of the reference power transmission device. Therefore, E ０ｇｙ , E ０ｇｇ , E １ｇｙ and E １ｇｇ must be coefficients representing the characteristics with respect to a reference power transmission device corresponding to the dZ ＰＴＸ of TX100.

[0138] RX200 holds, for each of E ０ｇｙ , E ０ｇｇ , E １ｇｙ and E １ｇｇ , values corresponding to the information (value of dZ ＰＴＸ ) regarding the dZ ＰＴＸ received from TX100 in F1104 in the memory 208. That is, RX200 holds, for example, the following information (1) to (3) ((1) to (3) are examples of association information associating the distance between the power transmission coil and the enclosure and the information for calculating or determining the coupling state between the power transmission device and the power reception device). (1) E ＰＴＸ for the case where dZ ０ｇｙ = 2.5 mm, E ０ｇｇ , E １ｇｙ and E １ｇｇ . (2) E for the case where dZ ＰＴＸ = 3.0 mm​０ｇｙ , E ０ｇｇ , E １ｇｙ and E １ｇｇ (3) dZ ＰＴＸ = E when 3.5 mm ０ｇｙ , E ０ｇｇ , E １ｇｙ and E １ｇｇ .

[0139] Therefore, RX200 receives dZ from TX100. ＰＴＸ Based on the information, the dZ ＰＴＸ E corresponding to ０ｇｙ , E ０ｇｇ , E １ｇｙ and E １ｇｇ Select this. Then, RX200 will use the selected eigencoefficient E ０ｇｙ , E ０ｇｇ , E １ｇｙ and E １ｇｇ Therefore, scaling factor α ０ｒｘ and α １ｒｘ Calculate and select.

[0140] Alternatively, another method is that the RX200 could, for example, dZ ＰＴＸ = E when 2.5 mm ０ｇｙ , E ０ｇｇ , E １ｇｙ and E １ｇｇ And, dZ ＰＴＸ = E when 3.5 mm ０ｇｙ , E ０ｇｇ , E １ｇｙ and E １ｇｇ The RX200 stores the information in memory 208. In other words, the RX200 stores correspondence information that associates the distance between the power transmission coil and the enclosure with the information for calculating or determining the coupling state between the power transmission device and the power receiving device. The RX200 then stores the dZ ＰＴＸ When E is between 2.5 mm and 3.5 mm ０ｇｙ , E ０ｇｇ , E １ｇｙ and E １ｇｇ This is calculated using linear interpolation. In other words, for RX200, the horizontal axis is dZ. ＰＴＸ Let the vertical axis be E ０ｇｙ , E ０ｇｇ , E １ｇｙ and E １ｇｇEach of these has a graph (data) or formula calculated or determined by linear interpolation. RX200 receives dZ from TX100. ＰＴＸ Information regarding (i.e., dZ) ＰＴＸ E corresponding to ) ０ｇｙ , E ０ｇｇ , E １ｇｙ and E １ｇｇ The eigenfactor E is calculated and selected from the graph (data) or formula. Then, RX200 selects the calculated eigenfactor E. ０ｇｙ , E ０ｇｇ , E １ｇｙ and E １ｇｇ From, α ０ｒｘ and α １ｒｘ Calculate and select. Note that linear approximation may be used instead of linear interpolation, in which case dZ ＰＴＸ Three or more values ​​may be used. Also, N dZ (where N is an integer greater than or equal to 3) ＰＴＸ When the value of is used for interpolation, RX200 uses an N-1 order interpolation polynomial to interpolate the dZ received from TX100. ＰＴＸ Information regarding (i.e., dZ) ＰＴＸ Alternatively, you may calculate and select the corresponding eigencoefficients.

[0141] Alternatively, the RX200 is dZ ＰＴＸ You may also select the scaling factor itself (information for calculating or determining the coupling state) for calculating the coupling state accordingly. The method for selecting the scaling factor for RX200 is described below.

[0142] The RX200's "dZ" ＰＴＸ The scaling factor for calculating the coupling state according to α ０ｒｘ and α １ｒｘ That is. The RX200 is α ０ｒｘ and α １ｒｘ For each of them, dZ ＰＴＸ The corresponding value is stored in memory 208. In other words, the RX200 stores, for example, the following information (1) to (3) (each of which is an example of correspondence information that associates the distance between the power transmission coil and the enclosure with information for calculating or determining the coupling state between the power transmission device and the power receiving device). (1) dZＰＴＸ = α when 2.5 mm ０ｒｘ and α １ｒｘ (2) dZ ＰＴＸ α when = 3.0 mm ０ｒｘ and α １ｒｘ (3) dZ ＰＴＸ = α when 3.5 mm ０ｒｘ and α １ｒｘ .

[0143] Therefore, RX200 receives dZ from TX100. ＰＴＸ Based on the information, the dZ ＰＴＸ α corresponding to ０ｒｘ and α １ｒｘ Select this option.

[0144] Alternatively, another method is that the RX200 could, for example, dZ ＰＴＸ = α when 2.5 mm ０ｒｘ and α １ｒｘ And, dZ ＰＴＸ = α when 3.5 mm ０ｒｘ and α １ｒｘ The RX200 stores the information in memory 208. In other words, the RX200 stores correspondence information that associates the distance between the power transmission coil and the enclosure with the information for calculating or determining the coupling state between the power transmission device and the power receiving device. The RX200 then stores the dZ ＰＴＸ α when it is between 2.5 mm and 3.5 mm ０ｒｘ and α １ｒｘ This is calculated using linear interpolation. In other words, for RX200, the horizontal axis is dZ. ＰＴＸ Let the vertical axis be α ０ｒｘ and α １ｒｘ Each of these has a graph (data) or formula calculated or determined by linear interpolation. RX200 receives dZ from TX100. ＰＴＸ Information regarding (i.e., dZ) ＰＴＸ ) corresponding to α ０ｒｘ and α １ｒｘ The value is calculated and selected from the graph (data) or formula. Note that linear interpolation may be used instead of linear approximation; in this case, dZ ＰＴＸ Three or more values ​​may be used. Also, N dZ (where N is an integer greater than or equal to 3) ＰＴＸWhen the value of is used for interpolation, RX200 uses an N-1 order interpolation polynomial to interpolate the dZ received from TX100. ＰＴＸ Information regarding (i.e., dZ) ＰＴＸ Alternatively, you may calculate and select the corresponding eigencoefficients.

[0145] Next, the RX200 has a scaling factor (α ０ｒｘ (Alpha0 Rx) and α １ｒｘ A predetermined packet containing information about (Alpha1 Rx) is sent to TX100 (F1106). This packet is an MPP-Extended Identification Packet (Qi MPP Extended Identification, MPP-XID data packet) as defined in the Qi standard. RX200 sends the MPP-Extended Identification Packet to TX100 during the Ping phase or Configuration phase described above. This packet also contains the V measured by RX200. ｒｅｃｔ This also includes information about [the subject].

[0146] TX100 determines whether or not it has received a scaling factor related to coupling state calculation from RX200 (F1005). If TX100 determines that it has received a scaling factor related to coupling state calculation from RX200 (Yes in F1005), it proceeds to F1006. If TX100 determines that it has not received a scaling factor related to coupling state calculation from RX200 (No in F1005), it returns to F1005.

[0147] In F1006, TX100 calculates the coupling state using the scaling factor for coupling state calculation received from RX200. Then, in F1007, TX100 transmits the calculated coupling state information to RX200. Then, in F1008, TX100 performs control according to the calculated coupling state. "Control according to the calculated coupling state" means, for example, that TX100 has multiple resonant capacitors 107 (not shown), and TX100 may select the optimal resonant capacitor 107 from among the multiple resonant capacitors according to the calculated coupling state. Additionally or alternatively, "control according to the calculated coupling state" means, for example, that TX100 selects a noise suppression circuit according to the calculated coupling state. Additionally or alternatively, "control according to the calculated coupling state" means, for example, that TX100 predicts the power that can be transmitted according to the calculated coupling state. Additionally or alternatively, "control according to the calculated coupling state" may mean, for example, that TX100 selects the optimal parameters for in-band communication according to the calculated coupling state.

[0148] In F1107, RX200 determines whether or not it has received information regarding the coupling state calculated by TX100. If RX200 determines that it has received information regarding the coupling state calculated by TX100 (Yes in F1107), it proceeds to F1108. If RX200 determines that it has not received information regarding the coupling state calculated by TX100 (No in F1107), it returns to F1104. In F1108, RX200 performs control according to the calculated coupling state based on the received information. "Control according to the calculated coupling state" means, for example, that RX200 has multiple resonant capacitors 211 (not shown), and RX200 may select the optimal resonant capacitor 211 from among the multiple resonant capacitors according to the coupling state. Additionally or alternatively, "control according to the calculated coupling state" means, for example, that RX200 selects a noise suppression circuit according to the coupling state. Additionally or alternatively, "control based on the calculated coupling state" may mean, for example, that RX200 predicts the power that can be received based on the coupling state. Additionally or alternatively, "control based on the calculated coupling state" may mean, for example, that RX200 selects the optimal parameters for in-band communication based on the coupling state.

[0149] Figure 16 is a sequence diagram showing an example of processing by TX100 and RX200 according to the first embodiment.

[0150] The RX200 is mounted on the TX100 (S1601, S1602). The TX100 and RX200 perform the ping phase processing (S1603).

[0151] The RX200 is dZ ＰＴＸ A request to send a packet containing information about dZ is sent to TX100 (S1604). TX100 then sends a request to send a packet containing information about dZ. ＰＴＸ A packet containing information about dZ is sent to RX200 (S1605). RX200 then ＰＴＸA scaling factor for calculating the coupling state is selected or calculated according to the information (S1606). The RX200 transmits the selected or calculated coefficient (scaling factor) for calculating the coupling state to the TX100 (S1607).

[0152] TX100 transmits information about the calculated coupling state to RX200 (S1608). TX100 and RX200 perform control according to the calculated coupling state (S1609).

[0153] Note that the order of operations in the operation flow of TX100 and RX200 is not limited to the examples described above (for example, the examples shown in Figures 10, 11, and 16). Also, the operations of F1003 to F1008 and F1103 to F1108 are performed in the Ping phase or Configuration phase.

[0154] Furthermore, TX100 transmits a predetermined packet to RX200 when RX200 transmits a packet requesting TX100 to transmit a predetermined packet. Alternatively, TX100 may transmit a packet to RX200 even if RX200 does not transmit a packet requesting TX100 to transmit a packet.

[0155] RX200 transmits a packet to TX100 when TX100 transmits a packet requesting RX200 to transmit a packet. Alternatively, RX200 may transmit a packet to TX100 even if TX100 does not transmit a packet requesting RX200 to transmit a packet.

[0156] The same applies to embodiments other than this embodiment. The term "predetermined packet" is applicable to any packet.

[0157] By performing the above control on TX100 and RX200, TX100 will control the dZ of TX100. ＰＴＸ The dZ of the reference power transmission device ＰＴＸEven when the value differs from 1.2 mm, it becomes possible to calculate a more precise coupling state between the TX100 and RX200. Then, according to the highly precise coupling state, the TX100 and RX200 can perform more appropriate control.

[0158] [Second Embodiment] In the first embodiment, the dZ of TX100 ＰＴＸ However, if the value differs from the nominal value of 1.2 mm assumed in the current Qi standard's MPP, k ｅｓｔ A method for calculating with greater accuracy was described. In this embodiment, the dZ of TX100 ＰＴＸ However, this differs from the nominal value of 1.2 mm, and the dZ of the RX200 ＰＲＸ However, if it differs from the nominal value of 0.66 mm, k ｅｓｔ This section explains how to calculate dZ with high accuracy. ＰＲＸ The above nominal value of 1.2 mm is the nominal value assumed in the current Qi standard's MPP, and dZ ＰＲＸ The above nominal value of 0.66 mm is the nominal value assumed in the current Qi standard's MPP. Note that the configuration, operation, and processing in the second embodiment, other than those described below, are the same as or similar to those in the first embodiment, and therefore, their descriptions are omitted.

[0159] In the current Qi standard MPP, the TX100's dZ ＰＴＸ This is equivalent to 1.2 mm, and the dZ of the RX200 ＰＲＸ It is assumed that this is equivalent to 0.66 mm. The scaling factor and k described in the first embodiment ｅｓｔ The calculation method is also designed under that premise. Therefore, the dZ of the TX100 ＰＴＸ The distance is significantly different from 1.2 mm, and the dZ of the RX200 ＰＲＸ If the distance differs from 0.66 mm by a certain amount or more, the premise is broken, so k ｅｓｔ This could potentially make it impossible to calculate accurately.

[0160] Therefore, below, the dZ of the TX100 ＰＴＸThe distance is significantly different from 1.2 mm, and the dZ of the RX200 ＰＲＸ When the distance differs from 0.66 mm by a certain amount or more, k ｅｓｔ A method for accurately calculating this will be explained using Figures 12 and 13.

[0161] Figure 12 is a flowchart showing an example of processing by TX100 according to the second embodiment. Figure 13 is a flowchart showing an example of processing by RX200 according to the second embodiment.

[0162] First, the RX200 is mounted on the TX100 (F1201, F1301). Then, the TX100 and RX200 perform the Ping phase processing described above (F1202, F1302).

[0163] Next, the TX100 is the RX200's dZ ＰＲＸ A request to send a packet containing information about the above is sent to RX200 (F1203).

[0164] The RX200 is a successor to the TX100, and the RX200 is a successor to the dZ ＰＲＸ When a request to send a packet containing information is received (Yes in F1303), proceed to F1304. RX200 receives a packet from TX100, and then the RX200's dZ ＰＲＸ If a request to send a packet containing information is not received (No in F1303), the process returns to F1303. In F1304, RX200's dZ ＰＲＸ A packet containing information related to the above is sent to TX100. This packet may be, for example, a Report [PRX Identification] packet. Alternatively, this packet may be a newly defined packet.

[0165] Here, the dZ ＰＲＸ Information regarding dZ ＰＲＸ This is information indicating the distance.

[0166] For example, dZ ＰＲＸ The information indicating the distance is dZ ＰＲＸ The distance is such that it is a specific dZ, such as "2.5 mm" or "3.0 mm". ＰＲＸ This is information indicating the distance.

[0167] Alternatively, dZ ＰＲＸ The information indicating the distance is one of several predetermined distances, dZ ＰＲＸ This is information indicating the corresponding distance. For example, let's assume that distances of "2.5 mm", "3.0 mm", and "3.5 mm" are predetermined. Also, let's assume that RX200 sends information "1" to TX100 when the distance is "2.5 mm", information "2" when the distance is "3.0 mm", and information "3" when the distance is "3.5 mm". And, for example, dZ ＰＲＸ If the value is "3.0 mm", the RX200 sends the information "2" to the TX100.

[0168] Alternatively, dZ ＰＲＸ The information indicating the distance is the dZ ＰＲＸ This information indicates whether the value is below a predetermined threshold or within a predetermined range. For example, RX200 is dZ for TX100. ＰＲＸ If it is 3.0 mm or more, send the information "1", dZ ＰＲＸ If it is less than 3.0 mm, it sends the information "0". Alternatively, for example, the RX200 sends the dZ to the TX100. ＰＲＸ If the value is "1.5 mm or more but less than 2.0 mm", it sends the information "1". Also, for example, the RX200 sends dZ to the TX100. ＰＲＸ If the value is "2.0 mm or more but less than 2.5 mm", it sends the information "2". Also, for example, the RX200 sends the dZ to the TX100. ＰＲＸ If the value is "2.5 mm or more but less than 3.0 mm", then send the information "3".

[0169] The TX100 is an upgrade from the RX200, specifically the RX200 dZ. ＰＲＸ It determines whether or not a packet containing information about dZ has been received (F1204). TX100 receives information from RX200, dZ ＰＲＸ If a packet containing information about is received (Yes in F1204), proceed to F1205. TX100 receives information from RX200, dZ ＰＲＸ If no packet containing information is received (No in F1204), return to F1204.

[0170] In F1205, TX100 is dZ ＰＲＸ Information regarding (i.e., dZ) ＰＲＸ Select the intrinsic coefficients (information for calculating or determining the coupling state) related to the coupling state calculation according to the specified parameters. The method for selecting the intrinsic coefficients for TX100 is described below.

[0171] The TX100 selects "dZ ＰＲＸ The "inherent coefficients related to the calculation of the coupling state according to E" are ０ｘｇ and E １ｘｇ In other words, the eigenfactors that the TX100 is predetermined to hold in the Qi standard are the "dZ" selected by the TX100. ＰＲＸ This is an intrinsic coefficient related to the calculation of the coupling state according to the RX200. In this embodiment, the dZ ＰＲＸ The reference power receiving device's dZ ＰＲＸ = This is different from 0.66 mm. Therefore, E ０ｘｇ and E １ｘｇ Regarding dZ ＰＲＸ The RX200's dZ ＰＲＸ It needs to be a coefficient that represents the characteristics of a comparable reference power receiving device.

[0172] TX100 is E ０ｘｇ and E １ｘｇ For each of them, the RX200 dZ ＰＲＸ The corresponding value is stored in memory 106. In other words, TX100 stores, for example, the following information (1) to (3) (each of which is an example of correspondence information that associates the distance between the receiving coil and the enclosure with information for calculating or determining the coupling state between the transmitting device and the receiving device). (1) dZ ＰＲＸ = E when 2.5 mm ０ｘｇ and E １ｘｇ (2) dZ ＰＲＸ = E when 3.0 mm ０ｘｇ and E １ｘｇ (3) dZ ＰＲＸ = E when 3.5 mm ０ｘｇ and E １ｘｇ .

[0173] Therefore, TX100 receives dZ from RX200. ＰＲＸBased on the information, the dZ ＰＲＸ E corresponding to ０ｘｇ and E １ｘｇ Select this option.

[0174] Alternatively, another method is for the TX100 to use, for example, dZ ＰＲＸ = E when 2.5 mm ０ｘｇ and E １ｘｇ And, dZ ＰＲＸ = E when 3.5 mm ０ｘｇ and E １ｘｇ The and are stored in memory 106. In other words, TX200 stores correspondence information that associates the distance between the power receiving coil and the enclosure with information for calculating or determining the coupling state between the power transmitting device and the power receiving device. And TX100, dZ ＰＲＸ When E is between 2.5 mm and 3.5 mm ０ｘｇ and E １ｘｇ This is calculated using linear interpolation. In other words, for TX100, the horizontal axis is dZ. ＰＲＸ Let the vertical axis be E ０ｘｇ and E １ｘｇ Each of these has a graph (data) or formula calculated or determined by linear interpolation. TX100 receives dZ from RX200. ＰＲＸ Information regarding (i.e., dZ) ＰＲＸ E corresponding to ) ０ｘｇ and E １ｘｇ The value is calculated and selected from the graph (data) or formula. Note that linear interpolation may be used instead of linear approximation; in this case, dZ ＰＲＸ Three or more values ​​may be used. Also, N dZ (where N is an integer greater than or equal to 3) ＰＲＸ When the value of is used for interpolation, TX100 uses an N-1 order interpolation polynomial to interpolate the dZ received from RX200. ＰＲＸ Information regarding (i.e., dZ) ＰＲＸ Alternatively, you may calculate and select the corresponding eigencoefficients.

[0175] Next, the RX200 is the TX100's dZ ＰＴＸ A request to send a packet containing information about the above is sent to TX100 (F1305).

[0176] The TX100 is a successor to the RX200, and the TX100 is a successor to the dZ ＰＴＸ When a request to send a packet containing information is received (Yes in F1206), proceed to F1207. TX100 receives a packet from RX200, and the TX100's dZ ＰＴＸ If a request to send a packet containing information is not received (No in F1206), the process returns to F1206. In F1207, TX100's dZ ＰＴＸ Send a packet containing information about the above to RX200.

[0177] Here, the dZ ＰＴＸ Information regarding dZ ＰＴＸ This is information indicating the distance.

[0178] For example, dZ ＰＴＸ The information indicating the distance is dZ ＰＴＸ The distance is such that it is a specific dZ, such as "2.5 mm" or "3.0 mm". ＰＴＸ This is information indicating the distance.

[0179] Alternatively, dZ ＰＴＸ The information indicating the distance is one of several predetermined distances, dZ ＰＴＸ This is information indicating the corresponding distance. For example, let's assume that distances of "2.5 mm", "3.0 mm", and "3.5 mm" are predetermined. Also, let's assume that TX100 transmits information "1" to RX200 when the distance is "2.5 mm", information "2" when the distance is "3.0 mm", and information "3" when the distance is "3.5 mm". And, for example, dZ ＰＴＸ If the value is "3.0 mm", the TX100 transmits the information "2" to the RX200.

[0180] Alternatively, dZ ＰＴＸ The information indicating the distance is the dZ ＰＴＸ This information indicates whether the value is below a predetermined threshold or within a predetermined range. For example, TX100 is dZ for RX200. ＰＴＸ If it is 3.0 mm or more, send the information "1", dZ ＰＴＸ If it is less than 3.0 mm, it sends the information "0". Alternatively, for example, TX100 sends dZ to RX200. ＰＴＸIf the value is "1.5 mm or more but less than 2.0 mm", it sends the information "1". Also, for example, TX100 sends dZ to RX200. ＰＴＸ If the value is "2.0 mm or more but less than 2.5 mm", it sends the information "2". Also, for example, TX100 sends dZ to RX200. ＰＴＸ If the value is "2.5 mm or more but less than 3.0 mm", then send the information "3".

[0181] The RX200 is a successor to the TX100, and the dZ ＰＴＸ It determines whether or not a packet containing information about dZ has been received (F1306). RX200 receives from TX100, dZ ＰＴＸ If a packet containing information related to is received (Yes in F1306), proceed to F1307. RX200 receives information from TX100, dZ ＰＴＸ If no packet containing information is received (No in F1306), return to F1306.

[0182] In F1307, the RX200 is dZ ＰＴＸ Information regarding (i.e., dZ) ＰＴＸ Select the intrinsic coefficients (information for calculating or determining the coupling state) related to the calculation of the coupling state according to the specified parameters. Here, we will explain how to select the intrinsic coefficients for the RX200.

[0183] The RX200's "dZ" ＰＴＸ The "inherent coefficients related to the calculation of the coupling state according to E" are ０ｇｙ , E ０ｇｇ , E １ｇｙ and E １ｇｇ (Therefore, scaling factor α ０ｒｘ and α １ｒｘ ) In other words, the eigenfactor in E{a}{b}{c} described above, where {b} is g (reference power transmission device), is the "dZ" selected by RX200. ＰＴＸ This is an intrinsic coefficient related to the calculation of the coupling state according to TX100. In this embodiment as well, dZ ＰＴＸ The dZ of the reference power transmission device ＰＴＸ = This is different from 1.2 mm. Therefore, E ０ｇｙ , E ０ｇｇ , E １ｇｙ and E １ｇｇRegarding dZ ＰＴＸ TX100 dZ ＰＴＸ It needs to be a coefficient that represents the characteristics of a comparable reference power transmission device.

[0184] The RX200 is E ０ｇｙ , E ０ｇｇ , E １ｇｙ and E １ｇｇ For each of them, dZ ＰＴＸ The corresponding value is stored in memory 208. In other words, the RX200 stores, for example, the following information (1) to (3) (each of which is an example of correspondence information that associates the distance between the power transmission coil and the enclosure with information for calculating or determining the coupling state between the power transmission device and the power receiving device). (1) dZ ＰＴＸ = E when 2.5 mm ０ｇｙ , E ０ｇｇ , E １ｇｙ and E １ｇｇ (2) dZ ＰＴＸ = E when 3.0 mm ０ｇｙ , E ０ｇｇ , E １ｇｙ and E １ｇｇ (3) dZ ＰＴＸ = E when 3.5 mm ０ｇｙ , E ０ｇｇ , E １ｇｙ and E １ｇｇ .

[0185] Therefore, RX200 receives dZ from TX100. ＰＴＸ Based on the information, the dZ ＰＴＸ E corresponding to ０ｇｙ , E ０ｇｇ , E １ｇｙ and E １ｇｇ Select this. Then, RX200 will use the selected eigencoefficient E ０ｇｙ , E ０ｇｇ , E １ｇｙ and E １ｇｇ Therefore, scaling factor α ０ｒｘ and α １ｒｘ Calculate and select.

[0186] Alternatively, another method is that the RX200 could, for example, dZ ＰＴＸ = E when 2.5 mm ０ｇｙ , E０ｇｇ , E １ｇｙ and E １ｇｇ And, dZ ＰＴＸ = E when 3.5 mm ０ｇｙ , E ０ｇｇ , E １ｇｙ and E １ｇｇ The RX200 stores the information in memory 208. In other words, the RX200 stores correspondence information that associates the distance between the power transmission coil and the enclosure with the information for calculating or determining the coupling state between the power transmission device and the power receiving device. The RX200 then stores the dZ ＰＴＸ When E is between 2.5 mm and 3.5 mm ０ｇｙ , E ０ｇｇ , E １ｇｙ and E １ｇｇ This is calculated using linear interpolation. In other words, for RX200, the horizontal axis is dZ. ＰＴＸ Let the vertical axis be E ０ｇｙ , E ０ｇｇ , E １ｇｙ and E １ｇｇ Each of these has a graph (data) or formula calculated or determined by linear interpolation. RX200 receives dZ from TX100. ＰＴＸ Information regarding (i.e., dZ) ＰＲＸ E corresponding to ) ０ｇｙ , E ０ｇｇ , E １ｇｙ and E １ｇｇ The eigenfactor E is calculated and selected from the graph (data) or formula. Then, RX200 selects the calculated eigenfactor E. ０ｇｙ , E ０ｇｇ , E １ｇｙ and E １ｇｇ From, α ０ｒｘ and α １ｒｘ Calculate and select. Note that linear approximation may be used instead of linear interpolation, in which case dZ ＰＴＸ Three or more values ​​may be used. Also, N dZ (where N is an integer greater than or equal to 3) ＰＴＸ When the value of is used for interpolation, RX200 uses an N-1 order interpolation polynomial to interpolate the dZ received from TX100. ＰＴＸ Information regarding (i.e., dZ) ＰＴＸ Alternatively, you may calculate and select the corresponding eigencoefficients.

[0187] Alternatively, the RX200 is dZ ＰＴＸ You may also select the scaling factor itself (information for calculating or determining the coupling state) for calculating the coupling state accordingly. The method for selecting the scaling factor for RX200 is described below.

[0188] The RX200's "dZ" ＰＴＸ The scaling factor for calculating the coupling state according to α ０ｒｘ and α １ｒｘ That is. The RX200 is α ０ｒｘ and α １ｒｘ For each of them, dZ ＰＴＸ The corresponding value is stored in memory 208. In other words, the RX200 stores, for example, the following information (1) to (3) (each of which is an example of correspondence information that associates the distance between the power transmission coil and the enclosure with information for calculating or determining the coupling state between the power transmission device and the power receiving device). (1) dZ ＰＴＸ = α when 2.5 mm ０ｒｘ and α １ｒｘ (2) dZ ＰＴＸ α when = 3.0 mm ０ｒｘ and α １ｒｘ (3) dZ ＰＴＸ = α when 3.5 mm ０ｒｘ and α １ｒｘ .

[0189] Therefore, RX200 receives dZ from TX100. ＰＴＸ Based on the information, the dZ ＰＴＸ α corresponding to ０ｒｘ and α １ｒｘ Select this option.

[0190] Alternatively, another method is that the RX200 could, for example, dZ ＰＴＸ = α when 2.5 mm ０ｒｘ and α １ｒｘ And, dZ ＰＴＸ = α when 3.5 mm ０ｒｘ and α １ｒｘThe RX200 stores the information in memory 208. In other words, the RX200 stores correspondence information that associates the distance between the power transmission coil and the enclosure with the information for calculating or determining the coupling state between the power transmission device and the power receiving device. The RX200 then stores the dZ ＰＴＸ α when it is between 2.5 mm and 3.5 mm ０ｒｘ and α １ｒｘ This is calculated using linear interpolation. In other words, for RX200, the horizontal axis is dZ. ＰＴＸ Let the vertical axis be α ０ｒｘ and α １ｒｘ Each of these has a graph (data) or formula calculated or determined by linear interpolation. RX200 receives dZ from TX100. ＰＴＸ Information regarding (i.e., dZ) ＰＲＸ ) corresponding to α ０ｒｘ and α １ｒｘ The value is calculated and selected from the graph (data) or formula. Note that linear interpolation may be used instead of linear approximation; in this case, dZ ＰＴＸ Three or more values ​​may be used. Also, N dZ (where N is an integer greater than or equal to 3) ＰＴＸ When the value of is used for interpolation, RX200 uses an N-1 order interpolation polynomial to interpolate the dZ received from TX100. ＰＴＸ Information regarding (i.e., dZ) ＰＴＸ Alternatively, you may calculate and select a scaling factor corresponding to ).

[0191] The following describes another method for selecting the eigenfactors of the RX200. Here, the "dZ" selected by the RX200 is... ＰＴＸ The "inherent coefficients related to the calculation of the coupling state according to E" are ０ｇｇ and E １ｇｇ Therefore, the characteristic coefficient in the above-mentioned E{a}{b}{c} where {b} is g (reference power transmission device) and {c} is g (reference power receiving device) is the "dZ" selected by RX200. ＰＴＸ These are the "inherent coefficients related to the calculation of the coupling state according to the RX200. ０ｇｇ and E １ｇｇ For each of them, dZ ＰＴＸ +dZ ＰＲＸThe corresponding value is stored in memory 208. In other words, the RX200 stores, for example, the following information (1) to (4). (1) to (4) are examples of correspondence information that associates the sum of the distance between the transmitting coil and the enclosure and the distance between the receiving coil and the enclosure (or the distance between the transmitting coil and the receiving coil) with information for calculating or determining the coupling state between the power transmitting device and the power receiving device. (1) dZ ＰＴＸ +dZ ＰＲＸ = E when 1.86 mm ０ｇｇ and E １ｇｇ (2) dZ ＰＴＸ +dZ ＰＲＸ = E when 3.0 mm ０ｇｇ and E １ｇｇ (3) dZ ＰＴＸ +dZ ＰＲＸ = E when 3.5 mm ０ｇｇ and E １ｇｇ (4) dZ ＰＴＸ +dZ ＰＲＸ = E when 4.0 mm ０ｇｇ and E １ｇｇ .

[0192] Also, the RX200 is the RX200's dZ ＰＲＸ Assume that this is already stored in memory 208.

[0193] Therefore, RX200 receives dZ from TX100. ＰＴＸ Based on the information, dZ ＰＴＸ +dZ ＰＲＸ Calculate the dZ ＰＴＸ +dZ ＰＲＸ E corresponding to ０ｇｇ and E １ｇｇ Select this option.

[0194] Alternatively, another method is that the RX200 could, for example, dZ ＰＴＸ +dZ ＰＲＸ = E when 1.86 mm ０ｇｇ and E １ｇｇ And, dZ ＰＴＸ +dZ ＰＲＸ = E when 4.0 mm ０ｇｇ and E １ｇｇThe RX200 stores this information in memory 208. In other words, the RX200 stores correspondence information that associates the sum of the distance between the transmitting coil and the enclosure and the distance between the receiving coil and the enclosure (or the distance between the transmitting coil and the receiving coil) with information for calculating or determining the coupling state between the transmitting device and the receiving device. The RX200 then stores dZ ＰＴＸ +dZ ＰＲＸ When E is between 1.86 mm and 4.0 mm ０ｇｇ and E １ｇｇ This is calculated using linear interpolation. In other words, for RX200, the horizontal axis is dZ. ＰＴＸ +dZ ＰＲＸ Let the vertical axis be E ０ｇｇ and E １ｇｇ Each of these has a graph (data) or formula calculated or determined by linear interpolation. RX200 receives dZ from TX100. ＰＴＸ dZ calculated based on the information provided ＰＴＸ +dZ ＰＲＸ E corresponding to ０ｇｇ and E １ｇｇ The eigenfactor E is calculated and selected from the graph (data) or formula. Then, RX200 selects the calculated eigenfactor E. ０ｇｇ and E １ｇｇ And E, which was calculated and selected using the method described above. ０ｇｙ and E １ｇｙ And from, α ０ｒｘ and α １ｒｘ Calculate and select. Note that linear approximation may be used instead of linear interpolation, in which case dZ ＰＴＸ +dZ ＰＲＸ Three or more values ​​may be used. Also, N dZ (where N is an integer greater than or equal to 3) ＰＴＸ +dZ ＰＲＸ When the value of is used for interpolation, RX200 calculates dZ using an N-1 order interpolation polynomial. ＰＴＸ +dZ ＰＲＸ You may also calculate and select the corresponding eigencoefficients.

[0195] Next, the RX200 uses the scaling factor (α) obtained by the method described above. ０ｒｘ (Alpha0 Rx) and α １ｒｘA predetermined packet containing information about (Alpha1 Rx) is sent to TX100 (F1308). This packet is an MPP-Extended Identification Packet (Qi MPP Extended Identification, MPP-XID data packet) as defined in the Qi standard. RX200 sends the MPP-Extended Identification Packet to TX100 during the Ping phase or Configuration phase described above. This packet also contains the V measured by RX200. ｒｅｃｔ This also includes information about [the subject].

[0196] TX100 determines whether or not it has received a scaling factor related to coupling state calculation from RX200 (F1208). If TX100 determines that it has received a scaling factor related to coupling state calculation from RX200 (Yes in F1208), it proceeds to F1209. If TX100 determines that it has not received a scaling factor related to coupling state calculation from RX200 (No in F1208), it returns to F1208.

[0197] In F1209, TX100 calculates the coupling state using the scaling factor for coupling state calculation received from RX200. Then, in F1210, TX100 transmits the calculated coupling state information to RX200. Then, in F1211, TX100 performs control according to the calculated coupling state. "Control according to the calculated coupling state" means, for example, that TX100 has multiple resonant capacitors 107 (not shown), and TX100 may select the optimal resonant capacitor 107 from among the multiple resonant capacitors according to the calculated coupling state. Additionally or alternatively, "control according to the calculated coupling state" means, for example, that TX100 selects a noise suppression circuit according to the calculated coupling state. Additionally or alternatively, "control according to the calculated coupling state" means, for example, that TX100 predicts the power that can be transmitted according to the calculated coupling state. Additionally or alternatively, "control according to the calculated coupling state" may mean, for example, that TX100 selects the optimal parameters for in-band communication according to the calculated coupling state.

[0198] At F1309, RX200 determines whether or not it has received information regarding the coupling state calculated by TX100. If RX200 determines at F1309 that it has received information regarding the coupling state calculated by TX100 (Yes at F1309), it proceeds to F1310. If RX200 determines that it has not received information regarding the coupling state calculated by TX100 (No at F1309), it returns to F1309. At F1310, RX200 executes control according to the calculated coupling state based on the received information. "Control according to the calculated coupling state" means, for example, that RX200 has multiple resonant capacitors 211 (not shown), and RX200 may select the optimal resonant capacitor 211 from among the multiple resonant capacitors according to the coupling state. Additionally or alternatively, "control according to the calculated coupling state" means, for example, that RX200 may select a noise suppression circuit according to the coupling state. Additionally or alternatively, "control based on the calculated coupling state" may mean, for example, that RX200 predicts the power that can be received based on the coupling state. Additionally or alternatively, "control based on the calculated coupling state" may mean, for example, that RX200 selects the optimal parameters for in-band communication based on the coupling state.

[0199] Figure 17 is a sequence diagram showing an example of processing by TX100 and RX200 according to the second embodiment.

[0200] The RX200 is mounted on the TX100 (S1701, S1702). The TX100 and RX200 perform the ping phase processing (S1703).

[0201] TX100 is dZ ＰＲＸ A request to send a packet containing information about dZ is sent to RX200 (S1704). RX200 then sends a request to send a packet containing information about dZ. ＰＲＸ A packet containing information about dZ is sent to TX100 (S1705). TX100 then ＰＲＸ A scaling factor for calculating the coupling state is selected or calculated according to the information provided (S1706).

[0202] The RX200 is dZＰＴＸ A request to send a packet containing information about dZ is sent to TX100 (S1707). TX100 then sends a request to send a packet containing information about dZ. ＰＴＸ A packet containing information about dZ is sent to RX200 (S1708). RX200 then ＰＴＸ A scaling factor for calculating the coupling state is selected or calculated according to the information (S1709). The RX200 transmits the selected coefficient (scaling factor) for calculating the coupling state to the TX100 (S1710).

[0203] TX100 transmits information about the calculated coupling state to RX200 (S1711). TX100 and RX200 perform control according to the calculated coupling state (S1712).

[0204] By having TX100 and RX200 perform the above control, TX100 can calculate a more accurate coupling state between TX100 and RX200. That is, the dZ of TX100 ＰＴＸ The dZ of the reference power transmission device ＰＴＸ Unlike (1.2 mm), and also the RX200's dZ ＰＲＸ The reference power receiving device's dZ ＰＲＸ Even when the value differs from (0.66 mm), it becomes possible to calculate the bonding state with higher accuracy.

[0205] In the above-described embodiment, TX100 and RX200 are dZ ＰＴＸ Information and dZ ＰＲＸ They exchange information with each other, E ０ｘｇ , E １ｘｇ , E ０ｇｙ , E ０ｇｇ , E １ｇｙ and E １ｇｇThe method for selecting appropriate values ​​for all of these has been explained. However, it is not necessary to select appropriate values ​​for all of these for TX100 and RX200. TX100 and RX200 may select appropriate values ​​for only some of these inherent coefficients using the method described above, and use default values ​​for the remaining inherent coefficients without performing the process of selecting appropriate values ​​described above. Even setting only some of the inherent coefficients to appropriate values ​​will enable more accurate calculation of the coupling state than not performing the process of selecting appropriate values ​​at all. And, in accordance with the highly accurate coupling state, TX100 and RX200 will be able to perform more appropriate control.

[0206] Furthermore, the operations of F1203-F1211 and F1303-F1310 are performed during the Ping phase or the Configuration phase.

[0207] Furthermore, the order of operations in the operation flow of TX100 and RX200 is not limited to the examples described above (for example, the examples shown in Figures 12, 13, and 17). In the embodiment described above, RX200 first performs dZ ＰＴＸ Information is sent to TX100, and TX100 selects or calculates an appropriate scaling factor. Then TX100 performs dZ ＰＴＸ Information regarding this is sent to RX200, and RX200 selects or calculates an appropriate scaling factor. However, for example, this order may be reversed. That is, the processing order of F1203-F1205 and F1206-F1208 of TX100 may be swapped, and the processing order of F1303-F1304 and F1305-F1308 of RX200 may be swapped. In this case, RX200 will send dZ to the MPP-Extended Identification Packet. ＰＲＸ The packet may also be sent to TX100, including information related to the above. The same effect can be obtained with the above operation. That is, it becomes possible to calculate the coupling state with higher accuracy.

[0208] [Third Embodiment] In the first embodiment, the dZ of TX100 ＰＴＸ The dZ of the reference power transmission deviceＰＴＸ A method for accurately calculating the coupling state between TX100 and RX200 when it differs from 1.2 mm was described. In the second embodiment, the dZ of TX100 ＰＴＸ Unlike 1.2 mm, and also the dZ of the RX200 ＰＲＸ The reference power receiving device's dZ ＰＲＸ A method for accurately calculating the coupling state between TX100 and RX200 when it differs from 0.66 mm was described. In this embodiment, the threshold for determining the calculated coupling state between TX100 and RX200 is set to the dZ of TX100. ＰＴＸ A method for making a decision based on this will be explained. Note that the configurations, operations, and processes other than those in the third embodiment described below are the same as or similar to those in the first embodiment, so the explanation of those configurations, operations, and processes will be omitted.

[0209] Similar to the first embodiment, the dZ of TX100 ＰＴＸ The dZ of the reference power transmission device ＰＴＸ The case where the value differs from 1.2 mm will be explained using the flowcharts shown in Figures 10 and 11.

[0210] As described in the first embodiment, RX200 has a scaling factor (α) in F1106. ０ｒｘ (Alpha0 Rx) and α １ｒｘ A predetermined packet containing information about (Alpha1 Rx) is sent to TX100. This packet is an MPP-Extended Identification Packet (Qi MPP Extended Identification, MPP-XID data packet) as defined in the Qi standard.

[0211] In F1008, TX100 compares the calculated coupling state with a predetermined threshold. If the calculated coupling state is greater than (or equal to) the predetermined threshold, TX100 determines that it is a strongly coupled state and performs the control appropriate for a strongly coupled state. On the other hand, if the calculated coupling state is less than (or equal to) the predetermined threshold, TX100 determines that it is a weakly coupled state and performs the control appropriate for a weakly coupled state. This threshold is determined based on the αk_threhold (Alpha-Kth Rx) information included in the MPP-Extended Identification Packet described above.

[0212] αk_threhold is an ecosystem scaling coefficient used to determine the threshold. The threshold is calculated by multiplying a predetermined value of TX100 by αk_threhold.

[0213] Here, if foreign matter is introduced between TX100 and RX200, the bonding state will weaken, making it possible to detect foreign matter according to the bonding state. On the other hand, the bonding state between TX100 and RX200 is dZ ＰＴＸ It changes depending on dZ ＰＴＸ The longer the bond, the weaker the bond becomes. ＰＴＸ The shorter the bond, the stronger the bond. Therefore, the dZ of the TX100 ＰＴＸ The dZ of the reference power transmission device ＰＴＸ In the case of 1.2 mm, and the dZ of the TX100 ＰＴＸ The dZ of the reference power transmission device ＰＴＸ The coupling state between TX100 and RX200 differs depending on whether the value is 1.2 mm or not. More specifically, the coupling state between TX100 and RX200 differs when there is no foreign object and the transmitting coil and receiving coil are facing each other directly. Therefore, for example, in order to perform foreign object detection according to the calculated coupling state, it is necessary to correct the threshold value mentioned above. Also, in order to perform predetermined controls other than foreign object detection according to the calculated coupling state, it is necessary to correct the threshold value mentioned above.

[0214] In other words, RX200 receives dZ from TX100 at F1104. ＰＴＸ Information (dZ ＰＴＸ The value of αk_threhold is determined accordingly. RX200 is the first dZ ＰＴＸ For the value of , the first αk_threhold is determined, and the first dZ ＰＴＸ The second dZ is longer than ＰＴＸ For the given value, a second αk_threhold is determined that is smaller than the first αk_threhold.

[0215] Then, RX200 transmits the MPP-Extended Identification Packet containing the αk_threhold determined in F1106 to TX100.

[0216] At F1005, TX100 receives an MPP-Extended Identification Packet containing αk_threhold. Then, at F1008, TX100 calculates a threshold by multiplying a predetermined value by the αk_threhold.

[0217] By controlling TX100 and RX200 as described above, TX100 can appropriately set a threshold value for the calculated coupling state to determine whether to execute a predetermined control.

[0218] Next, we will describe the case in which the RX200 calculates the coupling state and performs predetermined control based on a predetermined threshold. The Qi standard states that the RX200 calculates an index called Gain and performs control by comparing this Gain with a predetermined threshold.

[0219] In this embodiment, the predetermined threshold is set to dZ of TX100 ＰＴＸ The method for making the decision will be explained using Figures 14 and 15.

[0220] Figure 14 is a flowchart showing an example of processing by TX100 according to the third embodiment, and Figure 15 is a flowchart showing an example of processing by RX200 according to the third embodiment.

[0221] First, the RX200 is placed on the TX100 (F1401, F1501). Then, the TX100 and RX200 perform the Ping phase processing described above (F1402, F1502). Finally, the TX100 and RX200 perform the Configuration phase processing described above (F1403, F1503).

[0222] Next, the RX200 disconnects its load (battery, etc.) (F1504). Alternatively, the RX200 controls the load so that only a small current of 50mA or less flows through it (F1504).

[0223] Next, RX200 sends a GET_Inverter Voltage packet to TX100 (F1505). The GET_Inverter Voltage packet is a GET data packet that notifies TX100 that RX200 is requesting information about the voltage of TX100's inverter. The GET data packet has a PRx Get Request Type of "PTx Inverter Voltage".

[0224] TX100 determines whether or not it has received a GET_Inverter Voltage packet from RX200 (F1404). If TX100 determines that it has received a GET_Inverter Voltage packet (Yes in F1404), it proceeds to F1405. If TX100 determines that it has not received a GET_Inverter Voltage packet (No in F1404), it returns to F1404.

[0225] In F1405, TX100 measures the voltage of the inverter of TX100, and the measured voltage of the inverter of TX100 (V ＩＮＶ Send an Inverter Voltage packet containing the information of the inverter voltage (V) of the TX100 to the RX200. ＩＮＶ ) refers to the input voltage input to the inverter of the TX100, or the output voltage output from the inverter of the TX100.

[0226] RX200 determines whether or not it has received an Inverter Voltage packet from TX100 (F1506). If RX200 determines that it has received an Inverter Voltage packet (Yes in F1506), it proceeds to F1507. If RX200 determines that it has not received an Inverter Voltage packet (No in F1506), it returns to F1506.

[0227] In F1507, RX200 is the output voltage after rectification in the rectifier circuit of RX200, V ｒｅｃｔ Measure the V ｒｅｃｔ Then, the first Gain (G1) is calculated from the voltage information of the inverter of TX100 received from TX100. The first Gain (G1) is calculated by the following formula: G1 = V ｒｅｃｔ / V ＩＮＶ

[0228] G1 is the V when the load on the RX200 is disconnected. ｒｅｃｔ and V ＩＮＶ This is the Gain calculated from the above. Gain is an index (coupling state index) that represents the coupling state between TX100 and RX200.

[0229] Next, connect the load (battery, etc.) to the RX200 (F1508).

[0230] Next, RX200 sends a GET_Inverter Voltage packet to TX100 (F1509).

[0231] TX100 determines whether or not it has received a GET_Inverter Voltage packet from RX200 (F1406). If TX100 determines that it has received a GET_Inverter Voltage packet (Yes in F1406), it proceeds to F1407. If TX100 determines that it has not received a GET_Inverter Voltage packet (No in F1406), it returns to F1406.

[0232] In F1407, TX100 measures the voltage of the inverter of TX100, and the measured voltage of the inverter of TX100 (V ＩＮＶSend an Inverter Voltage packet containing the information of ) to the RX200.

[0233] RX200 determines whether or not it has received an Inverter Voltage packet from TX200 (F1510). If RX200 determines that it has received an Inverter Voltage packet (Yes in F1510), it proceeds to F1511. If RX200 determines that it has not received an Inverter Voltage packet (No in F1510), it returns to F1510.

[0234] In F1511, RX200 is the output voltage after rectification in the rectifier circuit of RX200, V ｒｅｃｔ Measure the V ｒｅｃｔ Then, using the voltage information of the inverter of TX100 received from TX100, the second Gain (G2) is calculated. The second Gain (G2) is calculated using the following formula: G2 = V ｒｅｃｔ / V ＩＮＶ

[0235] G2 is the V when the RX200 load is connected. ｒｅｃｔ and V ＩＮＶ This is the gain calculated from [the formula / result].

[0236] Next, RX200 multiplies the calculated G1 and G2 to obtain G1 * G2 (G1 × G2) (F1512). Then, RX200 determines whether the calculated G1 * G2 is greater than or equal to the first threshold (or whether it is equal to or greater than the first threshold) (F1513).

[0237] RX200 determines that G1*G2 is greater than (or equal to or greater than) the first threshold (Yes in F1513), V ｒｅｃｔ＿ｔａｒｇｅｔ The first V ｒｅｃｔ＿ｔａｒｇｅｔ It was decided that P ｒ＿ｍａｘ to the first P ｒ＿ｍａｘ It is decided to be (F1514). Here, V ｒｅｃｔ＿ｔａｒｇｅｔ This refers to the target V in loop control. ｒｅｃｔ This is the value of P. ｒ＿ｍａｘThis refers to the maximum power value that the RX200 can draw, after rectification in the RX200's rectifier circuit. In other words, it is the maximum power value that the RX200 can receive.

[0238] If RX200 determines that G1*G2 is less than or equal to the first threshold (or less than the first threshold) (No in F1513), it proceeds to F1515. Then, RX200 determines whether G1*G2 is greater than or equal to the second threshold (or greater than or equal to the second threshold) (F1515).

[0239] RX200 determines that G1*G2 is greater than (or equal to or greater than) the second threshold (Yes in F1515), V ｒｅｃｔ＿ｔａｒｇｅｔ to the second V ｒｅｃｔ＿ｔａｒｇｅｔ It was decided that P ｒ＿ｍａｘ to the second P ｒ＿ｍａｘ This is the decision (F1516).

[0240] If RX200 determines that G1*G2 is less than or equal to the second threshold (or less than the second threshold) (No in F1515), it proceeds to F1517. Then, RX200 determines whether G1*G2 is greater than or equal to the third threshold (or greater than or equal to the third threshold) (F1517).

[0241] RX200 determines that G1*G2 is greater than (or equal to or above) the third threshold (Yes in F1517), V ｒｅｃｔ＿ｔａｒｇｅｔ to the third V ｒｅｃｔ＿ｔａｒｇｅｔ It was decided that P ｒ＿ｍａｘ to the third P ｒ＿ｍａｘ It is decided (F1518).

[0242] RX200 determines that G1*G2 is below the third threshold (or less than the third threshold) (No in F1517), V ｒｅｃｔ＿ｔａｒｇｅｔ to the fourth V ｒｅｃｔ＿ｔａｒｇｅｔ It was decided that P ｒ＿ｍａｘ to the fourth P ｒ＿ｍａｘ This is the decision (F1519).

[0243] Here, the relationship between the thresholds mentioned above is as follows: First threshold > Second threshold > Third threshold

[0244] Also, V ｒｅｃｔ＿ｔａｒｇｅｔThe relationship between the values ​​of the first V is as follows: ｒｅｃｔ＿ｔａｒｇｅｔ = Second V ｒｅｃｔ＿ｔａｒｇｅｔ The third V ｒｅｃｔ＿ｔａｒｇｅｔ = Fourth V ｒｅｃｔ＿ｔａｒｇｅｔ First V ｒｅｃｔ＿ｔａｒｇｅｔ > The third V ｒｅｃｔ＿ｔａｒｇｅｔ

[0245] Also, P ｒ＿ｍａｘ The relationship between the values ​​of the first P is as follows: ｒ＿ｍａｘ > Second P ｒ＿ｍａｘ > Third P ｒ＿ｍａｘ ≥ Fourth P ｒ＿ｍａｘ

[0246] In other words, the larger the value of G1*G2, which is an indicator of the coupling state between TX100 and RX200, the higher P ｒ＿ｍａｘ The value of is controlled to increase, and V accordingly. ｒｅｃｔ＿ｔａｒｇｅｔ The value of this value is also controlled.

[0247] Note that in the above, the threshold and V ｒｅｃｔ＿ｔａｒｇｅｔ and P ｒ＿ｍａｘ The numbers are three, four, and four, respectively, but are not limited to these numbers as long as the relationships between these values ​​are appropriately set.

[0248] Similar to the first embodiment, the dZ of TX100 ＰＴＸ The dZ of the reference power transmission device ＰＴＸ The method for setting the first, second, and third thresholds described above when the value differs from 1.2 mm will be explained.

[0249] The RX200 is the dZ of the TX100. ＰＴＸ The first dZ ＰＴＸ In that case, the first threshold is set to A, the second threshold to B, and the third threshold to C.

[0250] And the RX200 is the TX100's dZ ＰＴＸ The first dZ ＰＴＸ The second dZ is longer than ＰＴＸ In that case, the first threshold is set to D, the second threshold to E, and the third threshold to F.

[0251] Here, the thresholds A, B, C, D, E, and F have the relationships A > D, B > E, and C > F.

[0252] Gain (G1, G2, G1*G2) is an index used to determine, based on the coupling state, whether the RX200, which is placed on the TX100, is likely to be within a predetermined range. If the RX200 moves from outside the predetermined range to within the predetermined range, a sudden load change will occur, and overvoltage protection will be activated. Therefore, if it is determined in advance that there is a high probability that the RX200 is outside the predetermined range based on Gain, V ｒｅｃｔ＿ｔａｒｇｅｔ YaP ｒ＿ｍａｘ By setting it lower, wireless power transmission can be performed more safely. However, dZ ＰＴＸ If the TX100 is longer than a predetermined value, even though the TX100 and RX200 are facing each other directly, the Gain will fall below the threshold, V ｒｅｃｔ＿ｔａｒｇｅｔ YaP ｒ＿ｍａｘ It is anticipated that the threshold value may be set too low. In this embodiment, by controlling the threshold value as described above, it is possible to mitigate or prevent such unintended settings.

[0253] Figure 18 is a sequence diagram showing an example of processing by TX100 and RX200 according to the third embodiment.

[0254] The RX200 is mounted on the TX100 (S1801, S1802). The TX100 and RX200 perform the Ping phase processing (S1803). The TX100 and RX200 perform the Configuration phase processing (S1804).

[0255] RX200 disconnects its load (S1805). RX200 sends a GET_Inverter Voltage packet to TX100 (S1806). TX100 sends an Inverter Voltage packet to RX200 (S1807). RX200 calculates G1 (S1808).

[0256] RX200 connects its load (S1809). RX200 sends a GET_Inverter Voltage packet to TX100 (S1810). TX100 sends an Inverter Voltage packet to RX200 (S1811). RX200 calculates G2 (S1812).

[0257] RX200 calculates G1 * G2 (S1813). RX200 compares G1 * G2 with the first threshold and makes a determination (S1814). RX200 compares G1 * G2 with the second threshold and makes a determination (S1815). RX200 compares G1 * G2 with the third threshold and makes a determination (S1816). RX200 then V ｒｅｃｔ＿ｔａｒｇｅｔ and P ｒ＿ｍａｘ Decide (S1817).

[0258] As described above, the threshold for determining the coupling state between the calculated TX100 and RX200 is the dZ of TX100. ＰＴＸ By making decisions based on this, it becomes possible to perform wireless power transmission more effectively.

[0259] In this embodiment, TX100's dZ ＰＴＸ Accordingly, the threshold for making a predetermined determination based on the coupling state was changed. Similar to the "coupling state", the dZ of TX100 ＰＴＸ There are other physical quantities that change in response to this. For example, the foreign object detection method described above using the Power Loss method is based on the difference between the transmitted power and the received power, but this "difference between the transmitted power and the received power" is also related to the dZ of the TX100. ＰＴＸ It changes accordingly. This is because the power transmission efficiency decreases as the distance between the transmitting coil and the receiving coil increases. Therefore, the threshold for foreign object detection using the Power Loss method described above is also the dZ of TX100, as explained in this embodiment. ＰＴＸ It is changed accordingly. In other words, in foreign object detection using the Power Loss method, the dZ of TX100 ＰＴＸ If the first value is set, a first threshold is set for determining the presence or absence of foreign matter in relation to the "difference between transmitted power and received power". Then, TX100's dZ ＰＴＸIf the second value is longer than the first value, a second threshold greater than the first threshold for determining the presence or absence of foreign matter is set for the "difference between transmitted power and received power". As described above, the threshold for determining the presence or absence of foreign matter between TX100 and RX200 is set for TX100's dZ ＰＴＸ By making decisions based on this, it becomes possible to perform wireless power transmission more effectively.

[0260] Using a similar approach, the TX100's dZ ＰＴＸ For the threshold set for a physical quantity that changes in accordance with this, the dZ of TX100 is set using the method described in this embodiment. ＰＴＸ By making decisions based on this, it becomes possible to properly execute wireless power transmission.

[0261] [Fourth Embodiment] In the third embodiment, the threshold for determining the coupling state between the calculated TX100 and RX200 is the dZ of TX100. ＰＴＸ A method for determining based on the following was described. In this embodiment, the threshold for determining the coupling state between the calculated TX100 and RX200 is the dZ of TX100. ＰＴＸ and RX200 dZ ＰＲＸ A method for making a decision based on this will be explained. Note that the configurations, operations, and processes other than those in the fourth embodiment described below are the same as or similar to those in the first embodiment, so the explanation of those configurations, operations, and processes will be omitted.

[0262] Similar to the second embodiment, the dZ of TX100 ＰＴＸ Unlike 1.2 mm, and also the dZ of the RX200 ＰＲＸ The case where the value differs from 0.66 mm will be explained using the flowcharts shown in Figures 12 and 13.

[0263] As described in the second embodiment, RX200 has a scaling factor (α) in F1307. ０ｒｘ (Alpha0 Rx) and α １ｒｘA predetermined packet containing information about (Alpha1 Rx) is sent to TX100. This packet is an MPP-Extended Identification Packet (Qi MPP Extended Identification, MPP-XID data packet) as defined in the Qi standard.

[0264] In F1211, TX100 compares the calculated coupling state with a predetermined threshold. If the calculated coupling state is greater than (or equal to) the predetermined threshold, TX100 determines that it is a strongly coupled state and performs the control appropriate for a strongly coupled state. On the other hand, if the calculated coupling state is less than (or equal to) the predetermined threshold, TX100 determines that it is a weakly coupled state and performs the control appropriate for a weakly coupled state. This threshold is determined based on the αk_threhold (Alpha-Kth Rx) information included in the MPP-Extended Identification Packet described above.

[0265] αk_threhold is an ecosystem scaling coefficient used to determine the threshold. The threshold is calculated by multiplying a predetermined value of TX100 by αk_threhold.

[0266] Here, if foreign matter is introduced between TX100 and RX200, the bonding state will weaken, making it possible to detect foreign matter according to the bonding state. On the other hand, the bonding state between TX100 and RX200 is dZ ＰＴＸ and dZ ＰＲＸ It changes depending on dZ ＰＴＸ +dZ ＰＲＸ The longer the bond, the weaker the bond becomes. ＰＴＸ +dZ ＰＲＸ The shorter the dZ, the stronger the bond. Therefore, the bond between TX100 and RX200 will differ in case (1) and case (2) below. (1) dZ of TX100 ＰＴＸ The dZ of the reference power transmission device ＰＴＸ It is 1.2 mm, and the dZ of the RX200 ＰＲＸ The reference power receiving device's dZＰＲＸ (2) dZ of TX100 ＰＴＸ The dZ of the reference power transmission device ＰＴＸ Unlike the 1.2 mm and / or the dZ of the RX200 ＰＲＸ The reference power receiving device's dZ ＰＲＸ If it is different from 0.66 mm.

[0267] More specifically, the coupling state between TX100 and RX200 differs when there are no foreign objects and the transmitting and receiving coils are facing each other directly. Therefore, in order to perform foreign object detection according to the calculated coupling state, it is necessary to correct the threshold value mentioned above.

[0268] In other words, RX200 is the dZ calculated in F1307, as described in the second embodiment. ＰＴＸ +dZ ＰＲＸ The value of αk_threhold is determined accordingly. RX200 is the first dZ ＰＴＸ +dZ ＰＲＸ For the value of , the third αk_threhold is determined. Also, RX200 is the first dZ ＰＴＸ +dZ ＰＲＸ The second dZ is longer than ＰＴＸ +dZ ＰＲＸ For the given value, we determine a fourth αk_threhold that is smaller than the third αk_threhold.

[0269] Then, RX200 transmits the MPP-Extended Identification Packet containing the determined αk_threhold in F1308 to TX100.

[0270] TX100 receives an MPP-Extended Identification Packet containing αk_threhold at F1208. Then, at F1211, TX100 calculates a threshold by multiplying a predetermined value by the αk_threhold.

[0271] By controlling TX100 and RX200 as described above, TX100 can appropriately set a threshold value for the calculated coupling state to determine whether to execute a predetermined control.

[0272] Next, we will describe the case in which the RX200 calculates the coupling state and performs predetermined control based on a predetermined threshold. The Qi standard states that the RX200 calculates an index called Gain and performs control by comparing this Gain with a predetermined threshold.

[0273] In this embodiment, the predetermined threshold is set to dZ of TX100 ＰＴＸ and RX200 dZ ＰＲＸ The method for determining the appropriate behavior will be explained. In this embodiment, TX100 performs the same operation as in the flowchart shown in Figure 14 described in the third embodiment. Also, in this embodiment, RX200 performs the same operation as in the flowchart shown in Figure 15 described in the third embodiment. Therefore, the explanation of the flow in which RX200 calculates the coupling state and performs predetermined control based on predetermined thresholds will be omitted.

[0274] In this embodiment as well, the relationship between the first threshold shown at F1513, the second threshold shown at F1515, and the third threshold shown at F1517 in Figure 15 is as follows: First threshold > Second threshold > Third threshold

[0275] Furthermore, V described in F1516, F1518 and F1519 ｒｅｃｔ＿ｔａｒｇｅｔ The relationship between the values ​​of is as follows: First V ｒｅｃｔ＿ｔａｒｇｅｔ = Second V ｒｅｃｔ＿ｔａｒｇｅｔ The third V ｒｅｃｔ＿ｔａｒｇｅｔ = Fourth V ｒｅｃｔ＿ｔａｒｇｅｔ First V ｒｅｃｔ＿ｔａｒｇｅｔ > The third V ｒｅｃｔ＿ｔａｒｇｅｔ

[0276] Furthermore, P described in F1514, F1516, F1518 and F1519 ｒ＿ｍａｘ The relationship between the values ​​of is as follows: First P ｒ＿ｍａｘ > Second P ｒ＿ｍａｘ > Third P ｒ＿ｍａｘ ≥ Fourth P ｒ＿ｍａｘ

[0277] In other words, the larger the value of G1*G2, which is an indicator of the coupling state between TX100 and RX200, the higher P ｒ＿ｍａｘ The value of is controlled to increase, and V accordingly. ｒｅｃｔ＿ｔａｒｇｅｔ The value of this value is also controlled.

[0278] Note that in the above, the threshold and V ｒｅｃｔ＿ｔａｒｇｅｔ and P ｒ＿ｍａｘ The numbers are three, four, and four, respectively, but are not limited to these numbers as long as the relationships between these values ​​are appropriately set.

[0279] Similar to the second embodiment, the dZ of TX100 ＰＴＸ Unlike 1.2 mm, and also the dZ of the RX200 ＰＲＸ The method for setting the first, second, and third thresholds described above when the value differs from 0.66 mm will be explained below.

[0280] The RX200 is dZ ＰＴＸ +dZ ＰＲＸ The first dZ ＰＴＸ +dZ ＰＲＸ In that case, the first threshold is set to G, the second threshold to H, and the third threshold to I.

[0281] And the RX200 is, dZ ＰＴＸ +dZ ＰＲＸ The first dZ ＰＴＸ +dZ ＰＲＸ The second dZ is longer than ＰＴＸ +dZ ＰＲＸ In that case, the first threshold is set to J, the second threshold to K, and the third threshold to L.

[0282] Here, the thresholds G, H, I, J, K, and L have the relationships G > J, H > K, and I > L.

[0283] Gain (G1, G2, G1*G2) is an index used to determine, based on the coupling state, whether the RX200, which is placed on the TX100, is likely to be within a predetermined range. If the RX200 moves from outside the predetermined range to within the predetermined range, a sudden load change will occur, and the overvoltage protection will be activated. Therefore, if it is determined in advance that there is a high probability that the RX200 is outside the predetermined range based on Gain, Vｒｅｃｔ＿ｔａｒｇｅｔ YaP ｒ＿ｍａｘ By setting it lower, wireless power transmission can be performed more safely. However, dZ ＰＴＸ +dZ ＰＲＸ If the interval is longer than a predetermined value, even though TX100 and RX200 are facing each other, the Gain will fall below the threshold, and V ｒｅｃｔ＿ｔａｒｇｅｔ YaP ｒ＿ｍａｘ It is anticipated that the threshold value may be set too low. In this embodiment, by controlling the threshold value as described above, it is possible to mitigate or prevent such unintended settings.

[0284] As described above, the threshold for determining the coupling state between the calculated TX100 and RX200 is dZ ＰＴＸ +dZ ＰＲＸ By making decisions based on this, it becomes possible to perform wireless power transmission more effectively.

[0285] In this embodiment, TX100's dZ ＰＴＸ and RX200 dZ ＰＲＸ dZ is the sum of the above. ＰＴＸ +dZ ＰＲＸ Accordingly, the threshold for making a predetermined determination based on the coupling state was changed. Similar to the "coupling state", dZ ＰＴＸ +dZ ＰＲＸ There are other physical quantities that change in response to dZ. For example, the foreign object detection method described above using the Power Loss method is based on the difference between the transmitted power and the received power, but this "difference between the transmitted power and the received power" is also dZ. ＰＴＸ +dZ ＰＲＸ It changes accordingly. This is because the power transmission efficiency decreases as the distance between the transmitting coil and the receiving coil increases. Therefore, the threshold for foreign object detection using the Power Loss method described above is also dZ, as explained in this embodiment. ＰＴＸ +dZ ＰＲＸ It is changed accordingly. In other words, in foreign object detection using the Power Loss method, dZ ＰＴＸ +dZ ＰＲＸ If the first value is set, a first threshold is set for determining the presence or absence of foreign matter in relation to the "difference between transmitted power and received power". Then, dZ ＰＴＸ +dZＰＲＸ If the second value is longer than the first value, a second threshold greater than the first threshold for determining the presence or absence of foreign matter is set for the "difference between transmitted power and received power". As described above, the threshold for determining the presence or absence of foreign matter between TX100 and RX200 is set to dZ ＰＴＸ +dZ ＰＲＸ By making decisions based on this, it becomes possible to perform wireless power transmission more effectively.

[0286] Using a similar approach, dZ ＰＴＸ +dZ ＰＲＸ For the threshold value set for a physical quantity that changes in accordance with this, the method described in this embodiment is used to set the threshold value for dZ. ＰＴＸ +dZ ＰＲＸ By making decisions based on this, it becomes possible to properly execute wireless power transmission.

[0287] [Other Embodiments] Some (or all) of the configurations in the above embodiments may be replaced with other configurations that perform similar functions, or omitted, and other configurations may be added. Furthermore, it is not limited to the WPC standard and can be applied to various standards.

[0288] Furthermore, for example, the receiving device may possess some or all of the functions of the power transmission device (see, for example, Figure 6). Alternatively, the receiving device may perform some or all of the processes that the power transmission device should perform (see, for example, Figures 7, 10, 12, and 14).

[0289] Furthermore, the configurations in the above-described embodiment may be combined as appropriate. Also, in the above embodiment, dZ of TX100 ＰＴＸ The dZ of the reference power transmission device ＰＴＸ It was stated that even when the dZ of the TX100 differs from 1.2 mm, it is possible to calculate the coupling state of the TX100 and RX200 with higher precision. ＰＴＸ The dZ of the reference power transmission device ＰＴＸ Unlike (1.2 mm), and also the RX200's dZ ＰＲＸ The reference power receiving device's dZ ＰＲＸIt was stated that high-precision calculation is possible even when it differs from (0.66 mm). The method described in the above embodiment is dZ ＰＴＸ , or dZ ＰＴＸ and dZ ＰＲＸ This method can be applied to physical quantities other than those used to calculate the coupling state between TX100 and RX200, whose characteristics change depending on the distance between them.

[0290] Furthermore, the power transmission and receiving devices may be, for example, image input devices such as imaging devices (still cameras, video cameras, etc.) or scanners, or image output devices such as printers, copiers, or projectors. In addition, the power transmission and receiving devices may be storage devices such as hard disk drives or memory devices, or information processing devices such as personal computers (PCs), smartphones, or tablet devices.

[0291] Furthermore, the power receiving device in this disclosure may also be an information terminal device. For example, an information terminal device has a display unit that displays information to the user and is supplied with power received from a power receiving antenna. The power received from the power receiving antenna is stored in a power storage unit (battery), and power is supplied to the display unit from the battery. In this case, the power receiving device may also have a communication unit that communicates with other devices different from the power transmitting device. The communication unit may support communication standards such as NFC communication or fifth-generation mobile communication systems (5G).

[0292] Furthermore, the power receiving device in this disclosure may be a vehicle such as an automobile. For example, an automobile that is a power receiving device may receive power from a charger (power transmission device) via a power transmission antenna installed in a parking lot. Alternatively, an automobile that is a power receiving device may receive power from a charger (power transmission device) via a power transmission antenna embedded in the road. Such an automobile supplies the received power to a battery. The power from the battery may be supplied to a drive unit (motor, electric unit) that drives the wheels, or it may be used to drive sensors used for driving assistance or a communication unit that communicates with external devices. In other words, in this case, the power receiving device may have a battery, motors and sensors that are driven using the received power, and a communication unit that communicates with devices other than the power transmission device, in addition to the wheels. Furthermore, the power receiving device may have a compartment for accommodating people. For example, sensors may be used to measure the distance between vehicles or the distance to other obstacles. The communication unit may, for example, be compatible with the Global Positioning System (Global Positioning Satellite, GPS). The communication unit may also be compatible with communication standards such as the fifth-generation mobile communication system (5G). Furthermore, the vehicle may be a bicycle or a motorcycle.

[0293] Furthermore, the power receiving device in this disclosure may be a power tool, a home appliance, etc. These devices, which are power receiving devices, may have a battery, as well as a motor that is driven by the power received from the battery. These devices may also have a notification means for notifying the remaining battery level, etc.

[0294] Furthermore, these devices may have a communication unit that communicates with other devices different from the power transmission equipment.

[0295] The communications section may support communication standards such as NFC and fifth-generation mobile communication systems (5G).

[0296] Furthermore, the power transmission device of this disclosure may also be an in-vehicle charger that transmits power to portable information terminal devices such as smartphones and tablets that support wireless power transmission within a vehicle.

[0297] Such in-car chargers can be installed anywhere inside the vehicle. For example, they may be installed on the car's console, on the instrument panel (dashboard), between the passenger seats, on the ceiling, or on the doors.

[0298] However, it is best not to install them in locations that would interfere with driving. Also, although the power transmission device was explained using the example of an on-board charger, such chargers are not limited to those installed in vehicles; they may also be installed in transport vehicles such as trains, aircraft, and ships. In this case, the chargers may also be installed between passenger seats, on the ceiling, or on doors.

[0299] Alternatively, a vehicle such as an automobile equipped with an on-board charger may also serve as a power transmission device. In this case, the power transmission device has wheels and a battery, and uses the power from the battery to supply power to the power receiving device via a power transmission circuit and a power transmission antenna.

[0300] This disclosure can also be implemented by supplying a program that implements one or more of the functions of the above-described embodiments to a system or device via a network or storage medium, and by having one or more processors in the computer of that system or device read and execute the program. It can also be implemented by a circuit (e.g., ASIC) that implements one or more functions.

[0301] Furthermore, some of the processes described in this disclosure with reference to the flowchart may be implemented in hardware. For example, a dedicated circuit can be automatically generated on the FPGA from a program to implement each step by using a predetermined compiler. Alternatively, a Gate Array circuit may be formed in the same way as the FPGA and implemented in hardware.

[0302] Furthermore, the following additional information is disclosed regarding the above embodiments.

[0303] [Note 1] A power transmission device for wirelessly transmitting power to a power receiving device, comprising: a power transmission coil; an enclosure enclosing the power transmission coil; a transmitting means for transmitting first information relating to the distance between the power transmission coil and the enclosure to the power receiving device; a receiving means for receiving second information corresponding to the first information from the power receiving device; and a determining means for determining the coupling state based on the second information.

[0304] [Note 2] The power transmission device according to Note 1, wherein the receiving means receives from the power receiving device a third piece of information relating to the distance between a power receiving coil having the power receiving device and an enclosure having the power receiving device that encloses the power receiving coil, the power transmission device further has a selection means for selecting a fourth piece of information corresponding to the third piece of information, and the determination means determines the coupling state based on the second piece of information and the fourth piece of information.

[0305] [Note 3] The power transmission device according to Note 2, characterized in that the selection means selects the fourth information corresponding to the third information using correspondence information which associates the distance between the power receiving coil and the enclosure with information for determining the coupling state between the power transmission device and the power receiving device.

[0306] [Note 4] The power transmission device according to Note 3, wherein the third information is included in the correspondence information, and the selection means selects as the fourth information information information for determining the coupling state between the power transmission device and the power receiving device that is associated with the third information in the correspondence information.

[0307] [Note 5] The power transmission device according to Note 3, wherein the third information is not included in the correspondence information, and the selection means selects the fourth information corresponding to the third information using a graph or calculation formula determined from the correspondence information.

[0308] [Note 6] The power transmission device according to any one of Notes 1 to 5, characterized in that the transmitting means transmits a fifth piece of information relating to the determined coupling state to the power receiving device.

[0309] [Note 7] The power transmission device according to any one of Notes 1 to 6, further comprising control means for performing control according to the coupling state.

[0310] [Note 8] A power receiving device that receives power wirelessly from a power transmitting device, comprising: a receiving means for receiving first information from the power transmitting device regarding the distance between a power transmitting coil having the power transmitting device and an enclosure having the power transmitting device that encloses the power transmitting coil; and a transmitting means for transmitting second information corresponding to the first information, which the power transmitting device uses to determine the coupling state between the power transmitting device and the power receiving device.

[0311] [Note 9] The power receiving device according to Note 8, further comprising a power receiving coil and an enclosure enclosing the power receiving coil, wherein the transmitting means transmits third information relating to the distance between the power receiving coil and the enclosure enclosing the power receiving coil to the power transmitting device.

[0312] [Note 10] The power receiving device according to Note 9, further comprising: a receiving means that receives a fourth piece of information relating to a first voltage of the power transmitting device from the power transmitting device; a receiving device that further comprises: a measuring means for measuring a second voltage of the power receiving device; a determining means for determining a coupling state index between the power transmitting device and the power receiving device, which includes a first coupling state index when the load of the power receiving device is disconnected and a second coupling state index when the load is connected, based on the first voltage and the second voltage indicated by the fourth piece of information; and a changing means for changing a threshold value compared with the product of the first coupling state index and the second coupling state index in accordance with the first piece of information.

[0313] [Note 11] The power receiving device according to Note 10, characterized in that the changing means changes the threshold according to the first information and the third information.

[0314] [Note 12] The power receiving device according to any one of Notes 8 to 11, further comprising selection means for selecting the second information corresponding to the first information using correspondence information which associates the distance between the power transmission coil and the enclosure with information for determining the coupling state between the power transmission device and the power receiving device.

[0315] [Note 13] The power receiving device according to Note 12, wherein the first information is included in the correspondence information, and the selection means selects as the second information information information for determining the coupling state between the power transmission device and the power receiving device that is associated with the first information in the correspondence information.

[0316] [Note 14] The power receiving device according to Note 12, wherein the first information is not included in the correspondence information, and the selection means selects the second information corresponding to the first information using a graph or calculation formula determined from the correspondence information.

[0317] [Note 15] The power receiving device according to any one of Notes 8 to 14, characterized in that the receiving means receives a fifth piece of information relating to the coupling state from the power transmitting device.

[0318] [Appendix 16] The power receiving device according to Appendix 15, further comprising control means for performing control according to the coupling state indicated by the fifth piece of information.

[0319] [Note 17] A method performed by a power transmission device that wirelessly transmits power to a power receiving device, comprising: transmitting first information relating to the distance between a power transmission coil having the power transmission device and an enclosure having the power transmission device that encloses the power transmission coil to the power receiving device; receiving second information corresponding to the first information from the power receiving device; and determining the coupling state based on the second information.

[0320] [Note 18] A method performed by a power receiving device that wirelessly receives power from a power transmitting device, comprising: receiving from the power transmitting device first information relating to the distance between a power transmitting coil having the power transmitting device and an enclosure having the power transmitting device that encloses the power transmitting coil; and transmitting to the power transmitting device second information corresponding to the first information, which the power transmitting device uses to determine the coupling state between the power transmitting device and the power receiving device.

[0321] [Appendix 19] A program that causes a computer to perform the actions described in Appendix 17 or 18.

[0322] The present invention is not limited to the embodiments described above, and various modifications and variations are possible without departing from the spirit and scope of the invention. Accordingly, the following claims are attached to make the scope of the invention public.

[0323] This application claims priority based on Japanese Patent Application No. 2024-158208, filed on 12 September 2024, and all of its contents are incorporated herein by reference.

[0324] 100 Power transmission device 101 201: Control unit 103 Power transmission unit 105 Power transmission antenna 200 Power receiving device 203 Power receiving unit 205 Power receiving antenna 303 Measurement unit 304 Setting unit 305 Status detection unit

Claims

1. A power transmission device for wirelessly transmitting power to a power receiving device, comprising: a power transmission coil; an enclosure containing the power transmission coil; a transmitting means for transmitting first information relating to the distance between the power transmission coil and the enclosure to the power receiving device; a receiving means for receiving second information corresponding to the first information from the power receiving device; and a determining means for determining the coupling state based on the second information.

2. The power transmission device according to claim 1, wherein the receiving means receives from the power receiving device a third piece of information relating to the distance between a power receiving coil having the power receiving device and an enclosure having the power receiving device that encloses the power receiving coil, the power transmission device further has a selection means for selecting a fourth piece of information corresponding to the third piece of information, and the determination means determines the coupling state based on the second piece of information and the fourth piece of information.

3. The power transmission device according to claim 2, characterized in that the selection means selects the fourth information corresponding to the third information using correspondence information which associates the distance between the power receiving coil and the enclosure with information for determining the coupling state between the power transmission device and the power receiving device.

4. The power transmission device according to claim 3, wherein the third information is included in the correspondence information, and the selection means selects as the fourth information information information for determining the coupling state between the power transmission device and the power receiving device that is associated with the third information in the correspondence information.

5. The power transmission device according to claim 3, wherein the third information is not included in the correspondence information, and the selection means selects the fourth information corresponding to the third information using a graph or calculation formula determined from the correspondence information.

6. The power transmission device according to claim 1, characterized in that the transmitting means transmits a fifth piece of information relating to the determined coupling state to the power receiving device.

7. The power transmission device according to claim 1, further comprising control means for performing control according to the coupling state.

8. A power receiving device that wirelessly receives power from a power transmitting device, comprising: a receiving means for receiving first information from the power transmitting device regarding the distance between a power transmitting coil having the power transmitting device and an enclosure having the power transmitting device that encloses the power transmitting coil; and a transmitting means for transmitting second information corresponding to the first information, which the power transmitting device uses to determine the coupling state between the power transmitting device and the power receiving device.

9. The power receiving device according to claim 8, further comprising a power receiving coil and an enclosure enclosing the power receiving coil, wherein the transmitting means transmits third information relating to the distance between the power receiving coil and the enclosure enclosing the power receiving coil to the power transmitting device.

10. The power receiving device according to claim 9, further comprising: a receiving means that receives fourth information relating to a first voltage of the power transmitting device from the power transmitting device; a power receiving device that further comprises: a measuring means for measuring a second voltage of the power receiving device; a determining means for determining a coupling state index between the power transmitting device and the power receiving device, which includes a first coupling state index when the load of the power receiving device is disconnected and a second coupling state index when the load is connected, based on the first voltage and the second voltage indicated by the fourth information; and a changing means for changing a threshold value compared with the product of the first coupling state index and the second coupling state index in accordance with the first information.

11. The power receiving device according to claim 10, characterized in that the modifying means modifies the threshold according to the first information and the third information.

12. The power receiving device according to claim 8, further comprising selection means for selecting the second information according to the first information using correspondence information which associates the distance between the power transmission coil and the enclosure with information for determining the coupling state between the power transmission device and the power receiving device.

13. The power receiving device according to claim 12, wherein the first information is included in the correspondence information, and the selection means selects as the second information information information for determining the coupling state between the power transmission device and the power receiving device that is associated with the first information in the correspondence information.

14. The power receiving device according to 12, wherein the first information is not included in the correspondence information, and the selection means selects the second information corresponding to the first information using a graph or calculation formula determined from the correspondence information.

15. The power receiving device according to claim 8, characterized in that the receiving means receives a fifth piece of information relating to the coupling state from the power transmitting device.

16. The power receiving device according to claim 15, further comprising control means for performing control according to the coupling state indicated by the fifth piece of information.

17. A method performed by a power transmission device that wirelessly transmits power to a power receiving device, comprising: transmitting first information relating to the distance between a power transmission coil having the power transmission device and an enclosure having the power transmission device that encloses the power transmission coil to the power receiving device; receiving second information corresponding to the first information from the power receiving device; and determining the coupling state based on the second information.

18. A method performed by a power receiving device that wirelessly receives power from a power transmitting device, comprising: receiving from the power transmitting device first information relating to the distance between a power transmitting coil having the power transmitting device and an enclosure having the power transmitting device that encloses the power transmitting coil; and transmitting to the power transmitting device second information corresponding to the first information, which the power transmitting device uses to determine the coupling state between the power transmitting device and the power receiving device.

19. A program for causing a computer to perform the method described in claim 17 or 18.

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