Power transmission device, power reception device, method performed by these devices, and program

Abstract

To provide a technique that allows appropriate execution of NFC tag detection processing during wireless power transmission.SOLUTION: A power transmission device negotiates with a power reception device, wirelessly transmits power to the power reception device on the basis of a result of the negotiation, and executes processing including detection of a near field communication (NFC) tag (F709-F724). At least in the negotiation, the power transmission device transmits, to the power reception device, information on the NFC tag detection executed during the power transmission (for example, threshold of transmitted power upon which power transmission adjustment is executed, inquiry standby time for inquiry timer settings and the like).SELECTED DRAWING: Figure 12

Description

Technical Field

[0001] The present disclosure relates to the technology of wireless power transmission.

Background Art

[0002] In recent years, the technological development of wireless power transmission systems has been widely carried out. The technology of wireless power transmission systems generally complies with the standards (WPC standards) formulated by the standardization organization Wireless Power Consortium (WPC) as wireless charging standards.

[0003] On the other hand, as a standard for short-range wireless communication, the NFC standard is known. NFC is an abbreviation for Near Field Communication. In the NFC standard, polling is defined as transmitting a message for detecting a device that becomes a communication partner by transmitting a carrier wave and modulating the carrier wave. Polling is transmitted by a device having a function called a reader / writer of the NFC standard. Also, a device that receives the polling transmitted by the reader / writer and has a function of performing load modulation on the carrier wave transmitted by the reader / writer to respond to this polling is called an NFC tag.

[0004] In addition, a power transmission device that complies with the WPC standard and is equipped with a reader / writer of the NFC standard can perform NFC tag detection in various processes of the WPC standard. The power transmission device can perform NFC tag detection processing while periodically performing NFC polling in the negotiation process and the power transmission process to the power receiving device.

[0005] Patent Document 1 discloses a technique in which a power transmission device having a function of detecting an NFC tag transmits information indicating the result (detection state) of the NFC tag detection process to a power receiving device during the negotiation process of the WPC standard. Specifically, the power transmission device transmits information indicating whether or not the NFC tag detection process has been executed, and information indicating whether or not an NFC tag has been detected when the NFC tag detection process has been executed, to the receiving device as the detection state.

[0006] In recent years, in wireless power transmission systems, there has been a demand for increasing the output power of the transmitted power. Efforts have been made to enhance the convenience for users by enabling high-speed charging through the increase in output power.

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0008] In wireless power transmission, frequency noise may occur. Such noise may interfere with the communication frequency used in NFC tag detection that can be performed during power transmission. As a result, the power transmission device may not be able to appropriately execute NFC tag detection.

[0009] The present disclosure provides a technology capable of appropriately executing NFC tag detection processing during wireless power transmission.

Means for Solving the Problems

[0010] A power transmission device according to an aspect of the present disclosure includes negotiation means for negotiating with a power reception device, power transmission means for wirelessly transmitting power to the power reception device based on the result of the negotiation, processing means for executing processing including detection of an NFC (Near Field Communication) tag, and communication means for transmitting information regarding NFC tag detection performed during the power transmission to the power reception device at least in the negotiation.

Effects of the Invention

[0011] According to the present disclosure, it is possible to appropriately execute NFC tag detection processing during wireless power transmission.

Brief Description of the Drawings

[0012]

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Embodiments for Carrying Out the Invention

[0013] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. Not all of the plurality of features in the embodiments of the present disclosure are essential, and the plurality of features may be arbitrarily combined. Also, the configurations shown in the following embodiments are merely examples, and the present disclosure is not limited to the illustrated configurations. By assigning the same reference numerals to the same or similar configurations in the drawings, duplicate explanations are omitted.

[0014] [First Embodiment] <Configuration of the System> FIG. 1 is a diagram showing a configuration example of a wireless power transmission system according to an embodiment. A configuration example of the wireless power transmission system according to this embodiment is shown. This wireless power transmission system includes, in one example, a power reception device 101 and a power transmission device 102. Hereinafter, for the sake of brevity of notation, the power transmission device 102 may be referred to as TX, and the power reception device 101 may be referred to as RX.

[0015] RX is, for example, an electronic device that receives power from TX and charges a built-in battery. Also, RX includes a WPC function compliant with the WPC (Wireless Power Consortium) standard and additionally corresponds to the device authentication protocol of this standard.

[0016] TX is, for example, an electronic device that wirelessly transmits power to an RX placed on its own device. TX wirelessly transmits power to RX via a power transmission antenna.

[0017] This system shall perform wireless power transmission using the electromagnetic induction method for non-contact charging based on the WPC standard. That is, the RX and TX perform wireless power transmission for non-contact charging based on the WPC standard between the power receiving antenna of the RX and the power transmitting antenna of the TX. Note that the wireless power transmission method (non-contact power transmission method) is not limited to the method defined by the WPC standard, and other electromagnetic induction methods, magnetic field resonance methods, electric field resonance methods, microwave methods, methods using lasers, etc. may also be used. Also, in this embodiment, it is assumed that wireless power transmission is used for non-contact charging, but wireless power transmission may be performed for applications other than non-contact charging.

[0018] In the WPC standard, the magnitude of the power guaranteed when the RX receives power from the TX is defined by a value called the guaranteed power, that is, Guaranteed Load Power (hereinafter referred to as "GP"). GP is the power value that is guaranteed to be output to the load of the RX, such as a circuit for charging, even if, for example, the positional relationship between the RX and the TX changes and the power transmission efficiency between the power receiving antenna and the power transmitting antenna decreases, that is, the load power value (Load Power) of the RX. Also, GP can be the load power level agreed upon through Negotiation between the TX and the RX. For example, when GP is 15 watts, even if the positional relationship between the power receiving antenna and the power transmitting antenna changes and the power transmission efficiency decreases, the TX controls the power transmission so that it can output 15 watts to the load within the RX.

[0019] <Configuration of the Power Receiving Device> FIG. 2 is a diagram showing an example of the configuration of the RX according to this embodiment. The RX includes a control unit 201, a WPC communication unit 203, a power receiving antenna (power receiving coil) 204, a power receiving unit 20, a detection unit 206, a charging unit 207, a battery 208, a notification unit 209, an operation unit 210, a memory 211, and a timer 212.

[0020] The control unit 201 controls the entire RX. The control unit 201 includes one or more processors such as a CPU (Central Processing Unit) or an MPU (Microprocessor Unit). Also, the control unit 201 can measure time using the timer 212. The control unit 201 performs control by executing, for example, a control program stored in the memory 211.

[0021] Note that the control unit 201 may be composed of hardware dedicated to specific processing such as an ASIC (Application Specific Integrated Circuit). Alternatively, the control unit 201 may be configured to include an array circuit such as an FPGA (Field Programmable Gate Array) compiled to execute predetermined processing. The control unit 201 stores information to be stored during the execution of various processes in the memory 211.

[0022] Note that in this embodiment, the control unit 201 is shown as one component, but it is not limited to this. For example, a WPC control unit that controls the power reception-related processing with the power transmission device in the power reception device may have a configuration separated from the control unit 201. Alternatively, a WPC control unit that controls the processing related to WPC communication may have a configuration separated from the control unit 201. In the case where the control unit 201 is separated into a plurality, each control unit is connected to each other by a communication interface and can perform data communication. Specifically, the communication interface may be any interface that realizes data communication such as I2C or GPIO.

[0023] The WPC communication unit 203 performs wireless power transmission communication based on the WPC standard with the communication unit 306 of the TX. The WPC communication unit 203 demodulates the electromagnetic wave input from the power reception antenna 204 to obtain the information transmitted from the TX, and modulates the electromagnetic wave by load modulation to superimpose the information to be transmitted to the TX on the electromagnetic wave, thereby performing communication with the TX. That is, the communication performed by the communication unit 306 is performed by being superimposed on the electromagnetic wave transmitted from the power transmission antenna 305 of the TX.

[0024] The power receiving unit 205 receives alternating current power (alternating voltage and alternating current) generated by electromagnetic induction based on the electromagnetic wave radiated from the transmission antenna of the TX via the power receiving antenna 204. The power receiving unit 205 converts the alternating current power into direct current or alternating current power of a predetermined frequency and outputs it to the detection unit 206. Primarily, the power receiving unit 205 is an example of power receiving means that wirelessly receives power from the power transmission device based on negotiation.

[0025] The detection unit 206 detects that the RX is placed on the TX based on the WPC standard. The detection unit 206 detects, for example, at least one of the voltage value and the current value of the power receiving antenna 204 when the power receiving unit 205 receives a Digital Ping of the WPC standard via the power receiving antenna 204. The detection unit 206 can determine that the RX is placed on the TX (in a power receivable state), for example, when the voltage value is below a predetermined voltage threshold or when the current value exceeds a predetermined current threshold.

[0026] The charging unit 207 charges the battery 208 with the power supplied from the power receiving unit 205. Also, the charging unit 207 starts or stops charging the battery 208 based on the control of the control unit 201, and further adjusts the power used for charging the battery 208 based on the charging state of the battery 208. When the power used by the charging unit 207 changes, the power supplied from the power receiving unit 205 accordingly, that is, the power receiving power in the RX also changes. The charging unit 207 shown here is a load in the RX.

[0027] The battery 208 supplies power for controlling each part of the RX by the control unit 201 and for power receiving and communication to the entire RX. Also, the battery 208 stores the power received via the power receiving antenna 204.

[0028] The notification unit 209 notifies the user of information by any method such as visual, auditory, or tactile means. The notification unit 209 notifies the user, for example, of the charging state of the RX and the state related to power transmission of the wireless power transmission system including the RX and TX as shown in FIG. 1. The notification unit 209 includes, for example, a liquid crystal display, an LED, a speaker, a vibration generation circuit, and / or other notification devices.

[0029] The operation unit 210 has a reception function for receiving operations on the RX from the user. The operation unit 210 includes, for example, buttons, a keyboard, a voice input device such as a microphone, a motion detection device such as an acceleration sensor and a gyro sensor, and / or other input devices. Note that a device in which the notification unit 209 and the operation unit 210 are integrated, such as a touch panel, may be used.

[0030] As described above, the memory 211 stores various information such as identification information and device configuration information, and control programs. Note that the memory 211 may store information obtained by a functional unit different from the control unit 201.

[0031] The timer 212 measures time, for example, by an up-counter timer that measures the elapsed time from the start time, a down-counter timer that counts down from the set time, or the like.

[0032] <Configuration of the power transmission device> FIG. 3 is a diagram showing an example of the configuration of the TX according to the present embodiment. The TX includes a control unit 301, a power supply unit 302, a power transmission unit 303, a detection unit 304, and a power transmission antenna (power transmission coil) 305. The TX also includes a communication unit 306, a notification unit 307, an operation unit 308, a memory 309, a timer 310, and an NFC (Near Field Communication) communication unit 311.

[0033] The control unit 301 controls the entire TX by executing, for example, a control program stored in the memory 309. That is, the control unit 301 controls each functional unit shown in FIG. 3. Further, the control unit 301 performs control related to power transmission control in the TX. Also, the control unit 301 performs control related to the NFC function in the TX. Furthermore, the control unit 301 may perform control for executing applications other than wireless power transmission. The control unit 301 includes one or more processors such as a CPU or an MPU, for example. Note that the control unit 301 may be composed of one processor, or a main control unit that controls the whole and sub-control units for controlling power transmission processing and NFC communication may be realized by different processors, respectively.

[0034] Note that the control unit 301 may be configured to include dedicated hardware for specific processing such as an application-specific integrated circuit (ASIC), or an array circuit such as an FPGA compiled to execute predetermined processing. The control unit 301 stores information to be stored during the execution of various processes in the memory 309. Also, the control unit 301 can measure time using the timer 310.

[0035] The power supply unit 302 supplies power necessary for controlling the TX by the control unit 301, power transmission, and communication to the entire TX. The power supply unit 302 is, for example, a commercial power supply or a battery. In the battery, the power supplied from the commercial power supply is stored.

[0036] The power transmission unit 303 converts the DC or AC power input from the power supply unit 302 into AC frequency power in a frequency band used for wireless power transmission, and generates an electromagnetic wave for causing the RX to receive power by inputting the AC frequency power to the power transmission antenna 305. The frequency of the AC power generated by the power transmission unit 303 is, for example, about several hundred kHz (for example, 110 kHz to 205 kHz). The power transmission unit 303 inputs the AC frequency power to the power transmission antenna 305 so as to output an electromagnetic wave for performing power transmission to the RX from the power transmission antenna 305 based on an instruction from the control unit 301.

[0037] In addition, the power transmission unit 303 controls the intensity of the electromagnetic wave to be output by adjusting the voltage (transmission voltage) or current (transmission current), or both, input to the power transmission antenna 305. When the transmission voltage or transmission current is increased, the intensity of the electromagnetic wave becomes stronger, and when the transmission voltage or transmission current is decreased, the intensity of the electromagnetic wave becomes weaker. Also, the power transmission unit 303 performs output control of AC frequency power so that power transmission from the power transmission antenna 305 is started or stopped based on an instruction from the control unit 301. Furthermore, the power transmission unit 303 notifies the control unit 301 of the current transmission power, enabling the control unit 301 to know the transmission power at an arbitrary timing at that timing. Note that the measurement of the transmission power and the notification to the control unit 301 may be configured to be performed outside the power transmission unit 303. Mainly, the power transmission unit 303 is an example of power transmission means that wirelessly transmits power to the power receiving device based on negotiation.

[0038] The detection unit 304 detects whether an object is placed on the TX based on the WPC standard. Specifically, the detection unit 304 detects whether an object is placed on the Interface Surface of the TX. For example, the detection unit 304 detects at least one of the voltage value and current value of the power transmission antenna 305 when the power transmission unit 303 transmits an Analog Ping of the WPC standard via the power transmission antenna 305.

[0039] Note that the detection unit 304 may detect a change in impedance. Then, when the voltage falls below a predetermined voltage value or the current value exceeds a predetermined current value, the detection unit 304 may determine that an object is placed on the TX. Whether this object is a power receiving device or other foreign object is determined by the presence or absence of a predetermined response to the Digital Ping subsequently transmitted by the communication unit 306. That is, when the TX receives a predetermined response, it is determined that the object is a power receiving device, and otherwise, it is determined that the object is an object different from the power receiving device.

[0040] The communication unit 306 performs control communication with the RX based on the WPC standard as described above. The communication unit 306 modulates the electromagnetic wave output from the power transmission antenna 305, transmits information to the RX, and conducts communication. Also, the communication unit 306 demodulates the electromagnetic wave output from the power transmission antenna 305 and modulated at the RX to obtain the information transmitted by the RX. That is, the communication performed by the communication unit 306 is carried out by being superimposed on the electromagnetic wave transmitted from the power transmission antenna 305.

[0041] The notification unit 307 notifies the user of information by any method such as visual, auditory, tactile, etc. The notification unit 307 notifies the user of, for example, the charging state of the TX and information indicating the state regarding power transmission of the wireless power transmission system including the TX and the RX as shown in FIG. 1. The notification unit 307 includes, for example, a liquid crystal display, an LED, a speaker, a vibration generating circuit, and / or other notification devices.

[0042] The operation unit 308 has a reception function for receiving an operation on the TX from the user. The operation unit 308 includes, for example, buttons, a keyboard, a voice input device such as a microphone, a motion detection device such as an acceleration sensor and a gyro sensor, and / or other input devices. Note that a device in which the notification unit 307 and the operation unit 308 are integrated, such as a touch panel, may be used.

[0043] The memory 309 stores various information such as identification information and capability information, and control programs. Also, the capability information includes information indicating whether it has a high-precision foreign object detection processing capability. Note that the memory 309 may store information obtained by a functional unit different from the control unit 301.

[0044] The timer 310 measures time, for example, by an up-counter timer that measures the elapsed time from the start time, a down-counter timer that counts down from the set time, or the like.

[0045] The NFC communication unit 311 is a hardware module that realizes the NFC function. Specifically, the NFC communication unit 311 realizes a card emulation mode that substitutes for the role of a contactless IC card, a reader / writer mode for reading the NFC tag 801, and a P2P mode for directly exchanging messages between NFCs. For example, using the card emulation mode enables electronic money settlement and the like.

[0046] Note that the communication unit 306 and the NFC communication unit 311 may be realized by one piece of hardware, or may be realized by separate pieces of hardware respectively.

[0047] <Basic Sequences of TX and RX> FIG. 4 is a sequence diagram showing an example of the control flow by TX and RX compliant with the WPC standard.

[0048] TX transmits Analog Ping (hereinafter expressed as A-Ping) for detecting an object existing in the vicinity of the power transmission antenna 305 (F400). A-Ping is pulsed power and is the power for detecting an object. A-Ping is so minute in power that even if RX receives A-Ping, it cannot activate the control unit 301 of RX. TX detects an object based on a shift in the resonance frequency of the voltage value inside the power transmission antenna 305 caused by an object existing in the vicinity of the power transmission antenna 305, or a change in the voltage value and / or current value flowing through the power transmission antenna 305.

[0049] When TX detects an object by A-Ping, it measures the Q value of the power transmission antenna 305 (F401), although the details are not described. After TX finishes measuring the Q value, it starts transmitting D-Ping (hereinafter referred to as D-Ping) (F402). D-Ping is the power for activating the control unit 301 of RX and is greater than the power of A-Ping. Also, D-Ping is continuously transmitted thereafter. That is, TX continues to transmit power equal to or greater than D-Ping from the start of transmitting D-Ping (F402) until it receives EPT (End Power Transfer) data requesting power transmission stop from RX (F416).

[0050] When RX starts up upon receiving D-Ping, it transmits Signal Strength, which is data storing the voltage value of the received D-Ping, to TX (F403). Subsequently, RX transmits data storing an ID including the version information of the WPC standard and device identification information that RX conforms to (F404). Further, RX transmits Configuration data including information such as the maximum value of the power supplied by the power receiving unit 205 to the load (or the charging unit 207) to TX (F405). When TX receives the ID and Configuration data and determines that RX supports the extended protocol (including Negotiation described later) of the WPC standard v1.2 or later, it responds with an ACK (F406).

[0051] When RX receives an ACK, it transitions to the NegotiationPhase (negotiation phase) where it conducts negotiations such as for the power to be transmitted and received. In the negotiation phase, the main control unit 201 of RX and the program for realizing the negotiation are examples of negotiation means. Similarly, the main control unit 301 of TX and the program for realizing the negotiation are examples of negotiation means. First, RX transmits FOD (Foreign Object Detection) Status data to TX (F407). In this embodiment, the FOD Status data is expressed as FOD(Q). TX performs foreign object detection based on the Q value stored in the received FOD(Q) and the Q value measured by Q value measurement, and transmits an ACK indicating that it is highly likely that there is no foreign object to RX (F408).

[0052] When RX receives an ACK, it transmits General Request (Capabilities), which is data for inquiring about the capabilities of TX and is one of the General Requests defined in the WPC standard (F409). Hereinafter, General Request (Capabilities) is expressed as GRQ(CAP). When TX receives GRQ(CAP), it transmits Capability data (referred to as CAP) storing the capability information it supports (F410).

[0053] Next, RX transmits General Request (ID) (expressed as GRQ(ID)), which is data for requesting TX to transmit identification information and is one of the General Requests defined in the WPC standard (F411). The identification information includes the corresponding standard version, etc. TX transmits the identification information in response to the request from RX (F412).

[0054] Subsequently, negotiation of GP is performed between TX and RX. That is, GP is a value that can be determined by agreement in the negotiation with TX. The GP requested by RX in the negotiation is the power corresponding to the power reception ability of RX, and can be set, for example, as the maximum value of the load power of RX (the power consumed by the charging unit 207). This negotiation is realized by transmitting data storing the value of GP requested by RX among the Specific Request data defined in the WPC standard to TX (F413). In the present embodiment, this data is expressed as SRQ(GP) (Specific Request (GP)).

[0055] TX responds to SRQ(GP) in consideration of its own power transmission ability and the like. When TX determines that GP can be accepted, it transmits an ACK indicating that the request has been accepted (F414), and when it determines that it cannot be accepted, it transmits a NAK indicating that the request is not accepted. When a NAK is transmitted, RX transmits SRQ(GP) with the value of the requested GP changed again and checks the response from TX. The processes of F413 and F414 are repeated until TX accepts GP and returns an ACK. In the present embodiment, it is assumed that RX requests 100 watts as GP in SRQ(GP).

[0056] Subsequently, it is data for RX to inquire about the extended ability of TX, and in the General Request defined in the WPC standard, GRQ(ACAP) is transmitted (F415). ACAP is an abbreviation for Additional Capabilities. ACAP includes additional information regarding the ability of TX. Details of ACAP will be described later. When TX receives GRQ(ACAP), it transmits ACAP storing the additional information corresponding to itself (F416).

[0057] When the negotiation of a plurality of parameters including GP is completed, RX transmits an SRQ(EN) that requests End Negotiation among Specific Requests to TX (F417). TX transmits an ACK to SRQ(EN) (F418) and ends the Negotiation. Then, it transitions to a power transmission phase in which power transmission and reception are performed with the power of GP determined in the Power Transfer Phase (F419).

[0058] After receiving the ACK, RX connects the power receiving unit 205 and the load (charging unit 207) and supplies the received power to the load. In a state where power is supplied to the load, RX transmits a Control Error (hereinafter referred to as CE) packet to TX according to the load. The CE packet is hereinafter referred to as CEP. A sign and a numerical value are stored in the CEP. If the sign of the numerical value stored in the CEP is positive, it means increasing the received voltage by that numerical value. If the sign of the numerical value stored in the CEP is negative, it means decreasing the received voltage by the numerical value. If the numerical value is zero (CE(0)), it means requesting to maintain the received voltage. Controlling the received voltage is equivalent to controlling the received power. Here, for example, RX transmits CE(+) indicating increasing the received voltage to TX (F420).

[0059] When TX receives CE(+), it changes the set value of the power transmission circuit in the power transmission unit 303 and increases the power transmission voltage (power transmission power). When RX confirms that the received power has increased in response to CE(+) (F421), it supplies the received power to the load (for example, charging unit 207) and transmits a Received Power Packet (RPP) to TX (F422). Here, the received power value in a state where RX supplies the output of the power receiving unit 205 to the load is stored in the RPP. After receiving and confirming the RPP, TX transmits an ACK to RX (F423). The processes from F420 to F423 are repeatedly executed during the power transmission phase.

[0060] Also, for example, in parallel with the processing of F420 to F423, TX performs processing including NFC tag detection of F424 and F425 (for example, F709 to F725 in FIG. 12 described later). The processing including NFC tag detection specifically means processing related to adjustment (for example, suppression) of the transmission power by TX including NFC tag detection. As shown in FIG. 13, for example, it is assumed that the NFC tag 801 enters between TX and RX, and F424 and F425 are processes for detecting it.

[0061] Specifically, since TX periodically executes NFC tag detection, it measures a predetermined time (F424). The predetermined time is the time set by an NFC timer described later and is an example of the execution standby time. The predetermined time is, for example, 50 ms, but is not limited to this. After the predetermined time has elapsed, TX executes the NFC tag detection process (F425). By repeating the NFC tag detection every predetermined time, TX can detect the appearance of the NFC tag during the power transmission phase.

[0062] In the present disclosure, "after ~ time has elapsed" literally means not only immediately after the time has elapsed, but also "at any time after the time has elapsed". For example, the "processing after ~ time has elapsed" is not limited to the processing immediately after the time has elapsed, and other processes may be included between the time when the time has elapsed and the target process. This is the same not only for "after elapsed" but also for, for example, "after exceeding a threshold value", etc.

[0063] When an NFC tag is detected, TX controls the transmission power to a predetermined value, taking into account that the NFC tag may be damaged by the electromagnetic wave during power transmission. The predetermined value is a value calculated according to the situation and can take multiple values according to the situation. The predetermined value can be 0 W, that is, power transmission may also stop. "According to the situation" means that, for example, when the NFC tag information contains information on the power tolerated by the NFC tag, TX controls the transmission power to be equal to or lower than the tolerated power. Or, "according to the situation" means that, for example, when the NFC tag information does not contain information allowing power transmission, TX sets the transmission power to, for example, the minimum value or stops power transmission.

[0064] Here, it should be noted that the process of adjusting the transmission power including NFC tag detection described above is different from the process of controlling the transmission power to a predetermined value as described above when an NFC tag is detected. Details will be described later.

[0065] The control unit 301, the NFC communication unit 311, the program for realizing NFC tag detection, the program for communicating with RX during power transmission, etc. are examples of processing means for executing processes including NFC tag detection. Also, the control unit 301, the communication unit 306, the program for communicating with RX during negotiation and power transmission, etc. are examples of communication means in the power transmission device. Similarly, the control unit 201, the WPC communication unit 203, the program for communicating with TX, etc. are examples of communication means in the power receiving device.

[0066] When the charging of the battery 208 is completed, RX transmits EPT (End Power Transfer) data requesting TX to stop power transmission (F426).

[0067] The above is the control flow of TX and RX compliant with the WPC standard and is the basic sequence of TX and RX processing in wireless power transmission.

[0068] From here, mainly in the power transmission phase with high output, as shown in FIG. 13, the processing when an NFC tag 801 enters between TX and RX will be described. Even in such a case, according to the present embodiment, power transmission with appropriate power can be performed, and NFC tag detection can be surely performed. This will be described with reference to FIGS. 5 to 12. FIGS. 5 to 8 are flowcharts showing the processing of RX. FIGS. 9 to 11 are flowcharts showing the processing of TX. FIG. 12 is a sequence diagram showing the processing of TX and RX.

[0069] In the present embodiment, TX and RX exchange various information in the negotiation phase before the power transmission phase in order to suppress (reduce) the power transmission power when detecting an NFC tag in the high-output power transmission phase. In the power transmission phase, TX uses this information to adjust (for example, suppress) the power transmission power in periodic NFC tag detection, and RX corresponding thereto responds to the adjustment of the power transmission power of TX. By the cooperation of TX and RX, both high-output power transmission and NFC tag detection are achieved.

[0070] <Processing by the power receiving device> FIGS. 5 to 8 are flowcharts showing an example of the processing executed by RX. FIG. 5 is a flowchart showing the processing in the negotiation phase, and FIGS. 6, 7, and 8 are flowcharts showing the processing in the power transmission phase. This processing can be realized, for example, by the control unit 201 of RX executing a program read from the memory 211. Note that at least a part of the following procedures may be realized by hardware. In this case, the hardware can be realized, for example, by automatically generating a dedicated circuit using a gate array circuit such as an FPGA from a program for realizing each processing step using a predetermined compiler. Also, this processing can be executed in response to the power of RX being turned on, or in response to RX being activated by power supply from the battery 208 or TX, or in response to the user of RX inputting an instruction to start a non-contact charging application. Also, this processing may be started by other triggers.

[0071] In S5001, RX executes basic command processing in the negotiation phase. Assume the processing from F407 to F414 in the sequence diagram described above. In S5002, RX transmits a GRQ(ACAP) message. The transmission of various messages from RX to TX is realized by the control unit 201 transmitting a message to the WPC communication unit 203.

[0072] In S5003, RX waits for an ACAP message from TX. The reception of a message from TX by RX is realized by the control unit 201 polling the WPC communication unit 203. After RX confirms the message, it holds the information received in S5004.

[0073] In this embodiment, as the message transmitted from TX, the content and format as shown in FIG. 20(A) can be assumed. RX can receive information about B0 "Threshold for power transmission suppression (e.g., 80W)", B1 "Inquiry time", B2 "Power during power transmission suppression", and B3 "Time of power transmission suppression" from TX.

[0074] The "threshold for power transmission suppression" is the threshold of the power transmission power that triggers the start of power transmission suppression.

[0075] The "inquiry time" is the time until an inquiry is executed for TX in the process including NFC tag detection in the power transmission phase (F709 to F724 in FIG. 12 described later). Here, an inquiry means a request by RX for TX to transmit predetermined information. The predetermined information includes, for example, the time until TX actually executes NFC tag detection. The predetermined information also includes the above B2 "Power during power transmission suppression" and B3 "Time of power transmission suppression".

[0076] As will be described later, the timing at which the inquiry time starts (the above transmission request is executed) is after RX has received and confirmed the "power transmission suppression ON / OFF switching information" (from OFF to ON in this case) from TX. In order to prepare for power transmission suppression when TX detects an NFC tag, RX needs to know the timing at which NFC tag detection is to be performed. Preparation for power transmission suppression mainly involves adjusting the processing load on the RX side, as will be described later. In this embodiment, it is assumed that RX performs transmission processing of CE (CEP) or RPP. Therefore, as will be described later, RX performs a query when a timer based on the query time is started and the CEP or RPP is transmitted after the timer is fired. The query time is, for example, 30 ms, but is not limited to this. The "query time" is an example of a query standby time.

[0077] "Power during power transmission suppression" is the transmission power during the period when the transmission power is suppressed ("time of power transmission suppression"). The power during power transmission suppression can take a value equal to or less than the "transmission power threshold value", for example, 40 W. As will be described later in [Other embodiments], stopping power transmission (i.e., 0 W) is also included in "power transmission suppression." Information on "power during power transmission suppression" is an example of adjustment power information.

[0078] The "power transmission suppression time" is the time for which the power transmission suppression state continues. The information on the "power transmission suppression time" is an example of duration information.

[0079] In S5005, RX sends SRC / EN to end the negotiation phase. In S5006, RX waits for ACK, and after confirming the ACK, ends the negotiation phase and moves to the power transmission phase from S5101 onwards.

[0080] Referring to FIG. 6, at S5101, RX checks whether it is command processing. If it is performing command processing, it proceeds to S5102. If it is not command processing, at S5117, it executes other processing and returns to S5101. A command mainly means a request sent from the RX side to the TX side. Examples of commands include CEP and RPP when YES at S5101.

[0081] At S5102, RX checks whether the power transmission suppression during NFC tag detection is currently in the ON state or the OFF state. The process of returning to S5101 via YES from S5103 to S5108 is the processing in the OFF state of power transmission suppression and the processing when the power transmission power does not exceed the above "threshold value of power transmission suppression" (for example, 80W).

[0082] At S5103, RX determines whether to transmit CE (CEP). If it is to transmit CE, at S5104, RX transmits CE to TX. If it does not transmit CE, at S5116, RX executes other command processing. Note that the request for controlling the power transmission power to TX, that is, CE, is executed regardless of the ON and OFF states of power transmission suppression (S5104, S5121 described later).

[0083] At S5105, RX checks the power transmission power by TX for the transmitted CE (F421). After checking the change in the power transmission power, at S5106, RX transmits RPP (Received Power Packet) to TX (F421). At S5107, RX waits for a response from TX for RPP. When it receives the response, at S5108, it checks the type of the response. If the response is ACK at S5108 (F423), RX returns to S5101. If the response is ATN (ATTENTION) (YES at S5109), at S5110, RX transmits DSR (Data Stream Response) / poll to TX. ATN is a response meaning that TX wants to send additional information to RX.

[0084] In S5111, RX waits for a response to DSR / poll, and in S5112, it checks the response content. If the response content is the "transmission suppression ON / OFF switching information" at the time of NFC tag detection, in S5113, RX checks the content of the switching information and returns to the process of S5101.

[0085] The transmission suppression ON / OFF switching information is information indicating whether to start or cancel transmission suppression in NFC tag detection under power transmission in the power transmission phase. Specifically, the transmission suppression ON / OFF switching information is information indicating the "switching from OFF to ON" for starting transmission suppression and information indicating the "switching from ON to OFF" for canceling it. In the case of YES in S5112, information indicating "switching from OFF to ON" is received. Here, since the current process passes through NO in S5102, YES in S5112 means "switching from OFF to ON", which means that the transmission power has exceeded the threshold value (for example, 80W).

[0086] In the following description, the "switching from OFF to ON" for the process of suppressing power transmission is expressed as "OFF→ON", and the "switching from ON to OFF" is expressed as "ON→OFF". Also, in the following description, the "transmission suppression ON / OFF switching information" may be abbreviated as "switching information".

[0087] Conversely, if it is not the "switching information" (NO in S5112), in S5114, RX executes the process corresponding to the content of the response received in S5112 and returns to S5101. Also, if the response in S5107 is neither ACK nor ATN (NO in S5108 and S5109), in S5115, RX executes the process corresponding to the content of the response received in S5112 and returns to S5101.

[0088] Next, the processing when power transmission suppression is ON during NFC tag detection in S5102 will be described with reference to FIG. 7. In S5118, RX determines whether to transmit CE (CEP). If transmitting CE, in S5119, RX starts a timer. If not transmitting CE, in S5135, RX executes other command processing and returns to S5101.

[0089] In S5119, RX sets the timer to the "inquiry time" obtained from TX in S5002 to S5004. Hereinafter, for convenience of explanation, this timer is referred to as the "inquiry timer". Starting the timer is realized by the control unit 201 operating the timer 212. In S5120, RX checks whether the inquiry timer has fired, that is, whether the set time has elapsed (or whether the current time has reached the set time). Confirming the firing of the inquiry timer is realized by the control unit 201 polling the timer 212. When RX confirms the firing of the inquiry timer, in S5121, it transmits CE, and in S5122, it checks the power transmission power. These processes are the same as the processes in S5104 and S5105.

[0090] In S5121, since the power transmission power exceeds the threshold (for example, 80W), it is preferable to transmit CE(-) to lower the power transmission power in S5121. However, it is not necessarily limited to the case where CE(-) is transmitted, and CE(+) or CE(0) may be transmitted. Even if CE(+) or CE(0) is transmitted, TX may ignore the request and execute power transmission suppression (S6120 described later).

[0091] In S5123, RX transmits RPP and waits for ATN in S5124. In the processing after S5118 when power transmission suppression is ON during NFC tag detection (the processing after S5118), it is assumed that TX transmits ATN in response to RPP (S6111 described later). After receiving ATN, in S5125, RX transmits DSR / poll to TX.

[0092] In S5126, RX waits for a response to DSR / poll and checks the response content in S5127 as shown in FIG. 8. As described above, when the transmitted power exceeds the threshold (NO in S6110 to be described later), and when the response content is not switching information (NO in S5127), the received response content means that RX has obtained the time until NFC tag detection. That is, in S6114 to be described later, TX transmits the time information until NFC tag detection, and RX receives this. In that case, in S5128, RX checks the response information and starts a timer in S5129. In S5129, a time corresponding to the time until NFC tag detection obtained in S5128 is set.

[0093] In S5130, RX checks whether the timer has fired. After the timer fires, in S5131, RX adjusts the processing load inside RX. The adjustment of the processing load here means controlling the processing load of RX so that RX can operate within the range of "power during power transmission suppression" obtained from TX in S5002 - S5004. Specific examples of the adjustment of the processing load include, for example, the following. Among the software being processed by the control unit 201 with a high processing load, stop it during the "power transmission suppression time" obtained from TX in S5004. Or, during the "power transmission suppression time" of the processing load, set the clock of the control unit 201 low, etc. Mainly, the program for adjusting the processing load of the control unit 201 is an example of an adjustment means for adjusting the processing load of the power receiving device.

[0094] After that, in S5132, RX waits for the recovery of the transmission power. This is realized by the control unit 201 polling the power receiving unit 205. When the transmission power is restored, in S5133, RX releases the control of the processing load performed in S5131 and returns to S5101. Also, when the content of the response in S5126 is "transmission suppression ON / OFF switching information" (YES in S5127), in S5134, RX checks the content of the switching information and returns to S5101. The switching information here is information indicating "ON→OFF" of the transmission suppression control in the detection of the NFC tag during power transmission. That is, this means that the transmission power has fallen below a threshold value (for example, 80W).

[0095] As described above, RX can communicate with TX and respond to the transmission suppression during NFC tag detection that switches according to the change in the transmission power.

[0096] <Processing by the power transmission device> FIGS. 9 to 11 are flowcharts showing examples of the processing executed by TX. FIG. 9 is a flowchart showing the processing in the negotiation phase, and FIGS. 10 and 11 are flowcharts showing the processing in the transfer phase. This processing can be realized, for example, by the control unit 301 of TX executing a program read from the memory 309. Note that at least a part of the following procedures may be realized by hardware. In this case, the hardware can be realized, for example, by automatically generating a dedicated circuit using a gate array circuit such as an FPGA from a program for realizing each processing step using a predetermined compiler. Also, this processing can be executed in response to the power of TX being turned on. Also, this processing may be started by other triggers.

[0097] In S6001, TX waits for the reception of a request. The reception of a request in TX can be realized by the control unit 301 polling the communication unit 306. TX waits in S6001 until a request comes. When TX receives a request, it performs processing in response to the request after S6002.

[0098] TX checks whether the request received at S6001 is GRQ(ACAP). This corresponds to the transmission of GRQ(ACAP) by RX at S5002. In the case of GRQ(ACAP), at S6003, TX transmits ACAP. This is the information received by RX at S5004 and, as described above, is B0 "Transmission suppression threshold (e.g., 80W)" / B1 "Inquiry time" / B2 "Power during transmission suppression" / B3 "Time of transmission suppression" shown in Fig. 20(A). The transmission from TX at S6003 is realized by the control unit 301 writing a message to the communication unit 306. After transmitting ACAP, the process returns to S6001.

[0099] If it is not GRQ(ACAP) at S6002, at S6004, TX checks whether the request received at S6001 is SRQ / EN. If it is SRQ / EN, at S6005, TX transmits ACK, ends the negotiation phase, and shifts to the power transmission phase process from S6101. If it is not SRC / EN, at S6006, TX performs the process corresponding to the received command and returns to S6001. S6006 corresponds to the process of RX's 5001 and corresponds to the processes from F407 to F414 in the above-described sequence diagram.

[0100] Referring to Fig. 10, at S6101, TX checks whether it has received a request from RX. If the request is CE, TX shifts to S6103 and controls the power transmission according to the request by CE from RX. The control of the power transmission is realized by the control unit 301 controlling the power transmission unit 303.

[0101] At S6104, TX waits for RPP. After confirming the reception of RPP, at S6105, TX checks the content of RPP to grasp the received power on the RX side. At S6106, TX determines whether it is necessary to switch the ON / OFF of transmission suppression ( "OFF→ON" or "ON→OFF") at the time of NFC tag detection. TX makes the determination at S6106 by checking its own power transmission. The control unit 301 can check the power transmission from TX at that time by checking the power transmission unit 303.

[0102] When the value of the power transmission power exceeds the threshold value (for example, 80 W), the control unit 301 sets it to "OFF → ON", and conversely, when it falls below the threshold value, it sets it to "ON → OFF". In S6107, after TX transmits ATN, it waits for DSR / poll from RX in S6108. When TX confirms the reception of DSR / poll, it transmits power transmission suppression ON / OFF switching information to RX in S6109 and returns to S6101. The switching information transmitted in S6109 can be confirmed by RX in S5113 or S5134.

[0103] When switching of power transmission suppression is not necessary in S6106, TX checks in S6110 whether the power transmission power is above or below the threshold value (for example, 80 W). Since the power transmission power being below the threshold value means that power transmission suppression is OFF and it is the normal power transmission phase, TX transmits ACK in S6111 and then returns to S6101.

[0104] Conversely, when the power transmission power exceeds the threshold value in S6110, TX transmits ATN in S6112 in order to transmit switching information to RX and waits for DSR / poll from RX in S6113. When TX confirms the reception of DSR / poll, it transmits the time until NFC tag detection in S6114 and returns to S6101. The time information until NFC tag detection transmitted in S6114 is the information that RX confirms in S5128 and is the information regarding the execution standby time described above. This means the remaining time of the set time (execution standby time, for example, 50 ms) of the NFC timer started in S6126 or S6128 described later. The remaining time of this NFC timer's set time is an example of the remaining execution time. Confirmation of the remaining time of the NFC timer is realized by the control unit 301 checking the remaining time of the corresponding timer of timer 310.

[0105] When it is not CE in S6102, TX executes other command processing in S6115 and returns to S6101.

[0106] When TX has not received a request from RX at S6101, with reference to FIG. 11, it determines at S6116 whether to perform NFC processing (NFC tag detection processing). If it is NFC processing, TX checks at S6117 whether the NFC timer is running. If it is not NFC processing, TX executes other processing at S6127 and returns to S6101. The timer at S6117 is the NFC timer (e.g., 50 ms) for the above-described periodic NFC tag detection, and as described above, it is realized by the control unit 301 checking the timer 310.

[0107] When the NFC timer is running at S6117, TX checks at S6118 whether the NFC timer has fired. If the NFC timer was not running, after starting the NFC timer at S6128, it returns to S6101. Starting the NFC timer is realized by the control unit 301 setting the time for the timer 310. Confirming the firing of the NFC timer is realized by the control unit 301 checking the corresponding timer of the timer 310. If the NFC timer has not fired at S6118, TX returns to S6101. If the NFC timer has fired, TX will perform power transmission suppression and NFC tag detection hereafter.

[0108] First, at S6119, TX checks whether the power transmission power exceeds the threshold. If the power transmission power exceeds the threshold, TX performs power transmission suppression at S6120 and then performs NFC tag detection at S6121. If the power transmission power is below the threshold, it directly moves to S6121. The power in the process of S6120 is the "power during power transmission suppression" in FIG. 20(A). The NFC tag detection process at S6121 is realized by the control unit 301 controlling the NFC communication unit 311.

[0109] At S6122, TX checks whether it is currently performing power transmission suppression. If it is performing power transmission suppression, after restoring the power transmission power at S6123, it moves to S6124. If TX is not performing power transmission suppression, it directly moves to S6124 and determines whether an NFC tag has been detected.

[0110] When an NFC tag is detected, various countermeasures can be considered for TX to execute. In this embodiment, after TX reduces the power transmission to a level that does not affect the NFC tag at S6125, it returns to S6101. If the NFC tag is not detected at S6124, at S6126, TX starts an NFC timer for the next NFC tag detection and then returns to S6101.

[0111] At S6120, by executing power transmission suppression, TX can suppress the generation of noise that affects communication during NFC tag detection and execute appropriate NFC tag detection processing. On the other hand, at S6125, by controlling the power transmission of TX to a predetermined value, for example, damage caused by electromagnetic waves to the NFC tag detected at S6124 is suppressed. The predetermined value is a value calculated according to the situation and can take multiple values according to the situation. "Controlled to a predetermined value" is as described above. In this way, the power transmission suppression at S6120 is performed to appropriately detect the NFC tag, and the control of the power transmission at S6125 is performed after the NFC tag is detected to suppress damage to the NFC tag. Thus, the purposes and their execution timings of both are different.

[0112] As described above, TX can communicate with RX and execute the processing of the power transmission phase while switching the ON / OFF of power transmission suppression during NFC tag detection along with the change in power transmission.

[0113] <Sequence of TX and RX during high-power transmission> Figure 12 is a sequence diagram showing an example of performing NFC tag detection while suppressing power transmission when the power transmission exceeds a threshold value (for example, 80W) from the sequence of the normal Power Transfer Phase in Figure 4.

[0114] RX transmits, for example, CE(+) (F701). TX that has received CE(+) controls the transmission power according to the request of RX (F702). TX confirms that the transmission power has exceeded the threshold value by controlling the transmission power (F703, YES in S6106, YES in S5102). Also, when RX confirms that the received power has increased in response to CE(+) (F704), it transmits RPP to TX (F705). The received power value in the state where RX supplies the output of the power receiving unit 205 to the load (charging unit 207) is stored in RPP.

[0115] TX that has confirmed RPP transmits ATN to RX (F706). RX that has received ATN transmits DSR / poll to TX (F707). TX that has received DSR / poll transmits information on transmission suppression ON to RX (F708, ON in S6109). As a result, both TX and RX recognize that transmission suppression is performed when an NFC tag is detected.

[0116] At the timing when the information on transmission suppression "OFF → ON" is transmitted to RX in F708 (S6109) and RX receives it (YES in S5112), the processing including NFC tag detection in the transmission suppression ON state (F709 to F724) is started. In the processing including NFC tag detection, as described below, TX activates an NFC timer until the detection is executed as a pre-stage of actually detecting the NFC tag (F709, S6128). When RX receives the "OFF → ON" information, it activates an inquiry timer for the "inquiry time" (ACAP information in F416) (F710, S5119).

[0117] RX transmits CE in response to the firing of the inquiry timer (F711, S5120) (F712, S5121). TX controls the transmission power according to CE (F713, S6103). When RX confirms that the received power has changed in response to CE (F714, S5121), it transmits RPP to TX (F715, S5123). The received power value in the state where RX supplies the output of the power receiving unit 205 to the load (charging unit 207) is stored in RPP.

[0118] Here, it is assumed that the power transmission suppression ON state continues, that is, the power transmission power exceeds the threshold (NO in S6106, NO in S6110). The TX that has confirmed the RPP transmits the ATN to the RX (F716, S6112). The RX that has received the ATN (YES in S5124) transmits the DSR / poll to the TX (F717, S5125). The TX that has received the DSR / poll (YES in S6113) sets the time information (remaining execution time) until the NFC tag detection and transmits this to the RX (F718, S6114). The RX that has received the time until the NFC tag detection (YES in S5126) starts the timer and sets the time (F719, NO in S5127, S5128).

[0119] When the timer until the NFC tag detection fires on the RX side (YES in F720, S5130), the RX executes the adjustment of the processing load (F721, S5131). On the other hand, when the NFC timer fires on the TX side (YES in F722, S6118), the TX executes the suppression of the power transmission power (F723, S6120). Then the TX executes the NFC tag detection process (F724, S6121) and restores the power transmission power (F725, S6123). The RX that has confirmed the restoration of the power transmission power (YES in S5132) releases the adjustment of the processing load (F716, S5133). The processes from F709 to F724 are repeated as long as the power transmission power exceeds the threshold.

[0120] In wireless power transmission, frequency noise is generated. For example, as the output power increases, the frequency band of the generated noise becomes wider and the generated noise also increases. As the output power increases, for example, noise may be generated that interferes with the communication frequency (e.g., 13.56 MHz) at the time of detecting the NFC tag that can be executed during power transmission. Therefore, if no countermeasures are taken, there is a possibility that the NFC tag detection cannot be appropriately executed. However, according to this embodiment, in the negotiation phase, the TX transmits the "power transmission suppression threshold", "inquiry time", "power during power transmission suppression", and "power transmission suppression time" to the RX via ACAP. Then, while the TX checks the power transmission power in the power transmission phase, if it exceeds the threshold, in the NFC tag detection process during the power transmission phase, the RX responds to the suppression of the power transmission power performed by the TX. Thereby, the TX can surely execute NFC tag detection during the power transmission phase. Therefore, even in a situation where noise that affects NFC tag detection communication is generated due to an increase in the power transmission power, it is possible to appropriately and surely perform the NFC tag detection process. That is, in this embodiment, it is possible to make both high-output wireless power transmission and NFC tag detection executed during wireless power transmission compatible.

[0121] In this embodiment, command processing by CEP / RPP is utilized. However, in the communication (communication after F710) in the NFC tag detection process in the power transmission phase, RPP may be used instead of CEP. Thereby, the processing efficiency can be improved. It is also possible to define a dedicated message regarding NFC tag detection in the power transmission phase.

[0122] [Second Embodiment] Next, as the second embodiment, similar to the first embodiment, mainly, in the high-output power transmission phase, the processing when the NFC tag 801 enters between the TX and the RX as shown in FIG. 13 will be described. In this embodiment, the TX and the RX use the information communicated in the negotiation phase to communicate in the power transmission phase and communicate about the information on the power during power transmission suppression and the suppression time for each NFC tag detection process. Thereby, flexible power transmission suppression is realized. In this embodiment, the description of the same elements and functions as in the first embodiment will be omitted.

[0123] [Processing by the Power Receiving Device] In the negotiation phase, RX executes the same processes as S5001 to S5006 shown in FIG. 5. However, in this embodiment, as the messages acquired from TX by ACAP in S5002 to S5004, the content and format as shown in FIG. 20(B) can be assumed. That is, RX acquires B0 "Threshold for power transmission suppression (e.g., 80 W)" / B1 "Inquiry time".

[0124] FIG. 14 is a flowchart showing the processes executed by RX in the power transmission phase. This process can be realized, for example, by the control unit 201 of RX executing a program read from the memory 211. In the power transmission phase, RX executes the same processes as S5101 to S5130, S5134, and S5135 shown in FIG. 6.

[0125] The processes after YES in S5130 become the processes after S9131. The timing of S5130 is the timing when the timer measures the time up to that time after acquiring the time from when the power transmission power exceeds the threshold value until the NFC tag is detected from TX (via YES of S5128 from S6114 to S5126). This is the same as in the first embodiment.

[0126] In this embodiment, at S9131, RX performs the CEP / RPP process again. The processes from S9131 to S9136 are the same as the processes from S5121 to S5126. The information received by RX from TX at S9136 is the information of "Power during power transmission suppression" / "Time of power transmission suppression" when executing this NFC tag detection process. RX performs processes related to the processing load in the same manner as after S5131 to S5133 based on the received information.

[0127] As described above, while communicating with TX, RX can respond to power transmission suppression during NFC tag detection, which switches with changes in the power transmission power.

[0128] <Processes by the power transmission device> In the negotiation phase, TX performs the same processing as S6001 to S6006 in FIG. 9. However, in this embodiment, the data transmitted to RX by ACAP in S6002 and S6003 is the information shown in FIG. 20(B), which is the value of "power transmission suppression threshold" / "inquiry time".

[0129] FIGS. 15(A) and (B) are flowcharts showing the processing executed by TX in the power transmission phase. This processing can be realized, for example, by the control unit 301 of TX executing a program read from the memory 309.

[0130] As shown in FIG. 15(A), in the power transmission phase, TX performs the same processing as YES to S6113 and S6115 in S6101 of FIG. 10. The timing of S6113 is the timing when, after TX transmits ATN in response to the RPP command received by RX in a state where the power transmission power exceeds the threshold, TX receives DSR / poll from RX.

[0131] After YES of S6113, at S1514, TX checks whether it has already transmitted the "time until NFC tag detection" to RX. In this embodiment, it is assumed that two communications (two CEP / RPP processes) are performed for NFC tag detection. Therefore, at S1514, TX checks whether the transmission of the "time until NFC tag detection" as the first communication has been completed.

[0132] If the transmission of the "time until NFC tag detection" has not been done yet, at S1515, TX transmits the "time until NFC tag detection" as the first communication. This is the same as the processing of S6114. On the other hand, if the "time until NFC tag detection" has already been transmitted, at S1516, TX transmits the power transmission power and suppression time during power transmission suppression as the second communication and returns to S6101. The information transmitted at S1516 is received by RX at S9137.

[0133] As shown in FIG. 15(B), TX performs the same processes as NO of S6101, S6116 to S6118, and S6119. At S1522, TX checks whether the transmission power during suppression and the suppression time have been transmitted. This means checking whether the transmission power during suppression and the suppression time have been transmitted to RX at S1516 in order to execute power transmission suppression in subsequent processes. If those pieces of information have been transmitted, TX executes the same processes as S6120 to S6126. If those pieces of information have not been transmitted, TX returns to S6101, and after going through the process of S1516, it returns to S1522 again. Note that TX also performs the same processes as S6127 and S6128 in FIG. 11.

[0134] As described above, TX can communicate with RX and execute the processes in the power transmission phase while switching ON / OFF the power transmission suppression at the time of NFC tag detection in accordance with the change in the power transmission.

[0135] <Sequence of TX and RX during high-output power transmission> FIG. 16 is a sequence diagram showing the processes of TX and RX. In FIG. 16, similar to FIG. 12, the process of exceeding the threshold value (for example, 80 W) of the power transmission from the sequence of the normal Power Transfer Phaswe in FIG. 4 and executing NFC tag detection while suppressing the power transmission will be described.

[0136] The processes from F1101 to F1120 are the same as the processes from F701 to F720. Also, the processes from F1121 to F1126 (from CE transmission to DSR / poll transmission) are the same as the processes from F1112 to F1117.

[0137] Upon receiving DSR / poll, TX transmits the information on the power transmission power during suppression and the suppression time to RX at F1127. This corresponds to the process of S1516. The processes from F1128 to F1133 are the same as the processes from F721 to F726. The processes from F1109 to F1133 are repeated as long as the power transmission power exceeds the threshold value.

[0138] According to the present embodiment as described above, in the negotiation phase, the TX transmits the "power transmission suppression threshold value" / "inquiry time" to the RX via ACAP. Then, while the TX checks the power transmission power in the power transmission phase, if it exceeds the threshold value, the "power transmission suppression threshold value" / "inquiry time" is transmitted for each NFC tag detection process during the power transmission phase. That is, in the first embodiment, the "power at the time of power transmission suppression" / "time of power transmission suppression" was transmitted in the negotiation phase, but in this embodiment, even during the power transmission phase, these pieces of information are transmitted dynamically (every time an NFC tag detection process is about to be performed). And the RX can surely execute NFC tag detection during the power transmission phase by corresponding to the suppression of the power transmission power performed by the TX. Therefore, even in a situation where noise that affects NFC tag detection communication is generated due to an increase in the power transmission power, it is possible to appropriately and surely perform the NFC tag detection process. That is, in this embodiment, it is possible to achieve both high-output wireless power transmission and NFC tag detection executed during wireless power transmission.

[0139] [Third Embodiment] Next, as in the first and second embodiments, as the third embodiment, mainly in the high-output power transmission phase, the processing when an NFC tag 801 enters between the TX and the RX as shown in FIG. 13 will be described. In this embodiment, when the NFC detection process is executed with the power transmission suppression in the ON state, regardless of an inquiry from the RX, the TX itself transmits information regarding power transmission suppression (information of the TX state notification described later) to the RX and performs power transmission suppression. Thereby, more flexible power transmission suppression is realized. In this embodiment, the description of the same elements and functions as those in the first and second embodiments will be omitted.

[0140] [Processing by the Power Receiving Device] In the negotiation phase, the RX executes the same processing as S5001 to S5006 shown in FIG. 5. However, in this embodiment, as the message acquired from the TX via ACAP in S5002 to S5004, the content and format as shown in FIG. 20(C) can be assumed. That is, the RX acquires B0 "power transmission suppression threshold value (for example, 80 W)".

[0141] Figure 17 is a flowchart showing the processing executed by RX in the power transmission phase. This processing can be realized, for example, by the control unit 201 of RX executing a program read from the memory 211.

[0142] Similar to the processing in FIG. 6, at S5101, RX determines whether it is command processing. If it is command processing, at S1702, it determines whether the command processing is transmission processing. If it is transmission processing, it proceeds to S5103 (FIG. 6). As shown in FIG. 6, RX executes the processing from S5103 to S5116 and also executes the processing of S5117 when the answer at S5101 is NO.

[0143] When it is not command transmission processing at S1702, at S1718, RX performs command reception processing. In this embodiment, since it is assumed that a command is also issued from TX, RX also performs reception processing of the command issued by that TX. The command reception processing at RX is realized by the control unit 201 polling the WPC communication unit 203. At S1718, RX checks whether the command received from TX is a TX status notification command. If it is not a TX status notification command, at S1725, RX executes the processing of the corresponding command and returns to S1701.

[0144] When the command received at S1718 is a TX status notification, at S1719, RX checks the content of the command. By the TX status notification, RX can grasp the current status of TX. FIG. 21 is a diagram showing an example of the content and format of the TX status notification command. The TX status notification command includes, in addition to the status information of TX, information on B1 "power during power transmission suppression" / B2 "time of power transmission suppression".

[0145] At S1720, the RX transmits an ACK to the TX. At S1721, the RX determines whether power transmission suppression during NFC tag detection processing is ON or not. If it is ON, at S5131, similar to the first and second embodiments, the RX uses the information of "power during power transmission suppression" / "time of power transmission suppression" in the TX status notification command received at S1718 to adjust the processing load of the RX. After that, the RX executes the processes of S5132 and S5133 in FIG. 6.

[0146] <Processing by the power transmission device> During the negotiation phase, the TX performs the same processing as S6001 - S6006 in FIG. 9. However, in this embodiment, the data transmitted by the TX using ACAP at S6002 and S6003 is the information shown in FIG. 20(C), which is B0 "threshold value of power transmission suppression".

[0147] FIG. 18 is a flowchart showing an example of the processing executed by the TX during the power transmission phase. This processing can be realized, for example, by the control unit 301 of the TX executing a program read from the memory 309.

[0148] During the power transmission phase, the TX performs the same processing as YES in S6101 - S6119 in FIG. 10, and also performs the same processing as YES in S6101 - S6114 and S6115.

[0149] After S6118, if the transmitted power exceeds the threshold value (for example, 80W) at S6119, since the TX needs to perform NFC tag detection under the condition that the transmitted power exceeds the threshold value, it is necessary to implement power transmission suppression. Therefore, in this embodiment, it is assumed that a command is transmitted from the TX side to the RX. At S1820, the TX prepares the information of "power during power transmission suppression" / "time of power transmission suppression", and at S1821, it transmits it to the RX as a TX status notification command (FIG. 21).

[0150] At S1822, the TX waits for an ACK from the RX, and then executes the processes of S6120 - S6126 in FIG. 11.

[0151] <Sequence of TX and RX during high - power transmission> Figure 19 is a sequence diagram showing the processing of TX and RX. In Figure 19, similar to Figures 12 and 16, the processing of executing NFC tag detection while suppressing power transmission from the normal Power Transfer Phase sequence of Figure 4 when the transmitted power exceeds a threshold value (for example, 80W) is explained.

[0152] The processing from F1401 to F1409 is the same as the processing from F701 to F709. Thereafter, TX checks the firing of the NFC timer started at F1409 (F1410). When the NFC timer fires, TX sends a TX status notification command to RX (F1411), and RX returns an ACK (F1412).

[0153] RX adjusts the processing load according to the information of "power during power transmission suppression" / "time of power transmission suppression" received at F1411 (F1413). The processing from F1414 to F1417 is the same as the processing from F723 to F726. The processing from F1409 to F1417 is repeated as long as the transmitted power exceeds the threshold value.

[0154] As described above, according to the present embodiment, in the negotiation phase, TX transmits the "power transmission suppression threshold" to RX by ACAP. Then, while TX checks the transmitted power in the power transmission phase, when it exceeds the threshold value, it transmits the "power transmission suppression threshold" / "inquiry time" for each NFC tag detection process during the power transmission phase. Different from the first and second embodiments, in this embodiment, since RX does not request control (CE) of the transmitted power according to its own load, TX does not wait for an inquiry from RX, but transmits the "power transmission suppression threshold" / "inquiry time" by itself. And RX can surely execute NFC tag detection during the power transmission phase by corresponding to the suppression of the transmitted power performed by TX. Therefore, even in a situation where noise that affects the communication of NFC tag detection is generated due to an increase in the transmitted power, it is possible to perform the NFC tag detection process appropriately and surely. That is, in this embodiment, it is possible to make both high-output wireless power transmission and NFC tag detection executed during wireless power transmission compatible.

[0155] [Other Embodiments] Hereinafter, other embodiments not limited to the described content will be described regarding the parts commonly described in the first to third embodiments above.

[0156] In the above, as a criterion for turning on power transmission suppression at the time of NFC tag detection, a method of checking the transmission power on the TX side has been described, but other methods are also possible. For example, it is also possible to determine based on the received power transmitted by the RX with RPP. That is, based on the determination criterion that the received power transmitted by the RX with RPP exceeds the threshold value, the TX can turn on the power transmission suppression. Alternatively, the TX may determine the threshold value based on the GP determined in the negotiation phase. In this case, the GP may be used as the threshold value, or both the GP and the threshold value may be used. In the latter case, for example, when the GP is determined to be a value exceeding the threshold value, it means that the power transmission suppression is always turned on in the NFC tag detection process in the Power Transfer Phase. Mainly the control unit 301, and the program for determining the threshold value is an example of a determination means. Alternatively, the power transmission profile determined in the negotiation phase may be used as a criterion. For example, when it is determined that the power profile is expected to be high output, it means that the power transmission suppression is always turned on in the NFC tag detection process in the Power Transfer Phase. Alternatively, conversely, in a power profile where the possibility of an NFC tag entering during the power transmission phase is extremely low, it is also possible to always turn off the power transmission suppression. This is assumed to be the case when the TX and RX are firmly connected and there is little room for foreign objects to enter, such as in a profile.

[0157] In each of the above embodiments, an example in which the RX adjusts the processing load for power transmission suppression during the NFC tag detection process has been described, but the present invention is not limited to this. For example, when sufficient power is supplied to the battery 208 of the RX and there is no problem even if the power transmission power is suppressed, the RX may perform a process of not adjusting the processing load. Further, the RX can also perform a process of determining whether to adjust the processing load based on the relationship between the power supply of wireless power transmission and the power consumption on the RX side. For example, in a situation where the RX is executing a high-load process and the power consumption on the RX side exceeds the power supplied from the TX, it is also possible to determine to adjust the processing load.

[0158] In each of the above embodiments, an example in which the TX reduces the power transmission power for power transmission suppression during the NFC tag detection process has been described, but the present invention is not limited to this. For example, power transmission may be stopped during NFC tag detection. However, when power transmission is stopped, attention is required for the corresponding measures on the RX side. If power transmission is stopped when the RX does not have a battery or even if it has a battery but the charge level is low, the previous state may be lost due to power loss, and there is a risk that the RX cannot communicate with the TX due to a state mismatch. Therefore, when the RX does not have a battery or even if it has a battery but the charge level is low, when the RX adjusts the processing load, it saves the state at that time in a non-volatile memory to prepare for power transmission stop. After the power transmission is resumed, the RX may restore the saved information so that the Power Transfer Phase can be continued. Also, the TX should hold the information regarding the state of the RX during the power transmission stop and make it possible to continue the power transmission phase with the RX after the power transmission is resumed. The information regarding the state of the RX is the information that the TX has received from the RX during the negotiation phase or the power transmission phase so far. The main control unit 201 is an example of a resumption means for resuming power reception based on the held information regarding the state of the power receiving device. Furthermore, the TX can also confirm the presence of the RX by issuing an Analog Ping during the power transmission stop in order to determine whether the RX has been moved from an appropriate charging position during the power transmission stop.

[0159] TX can also variably control the cycle (execution waiting time), inquiry time, and / or time until NFC tag detection (remaining execution time) of the NFC tag detection process based on the transmitted power. For example, when the transmitted power is high, it is preferable to perform NFC tag detection frequently. To achieve this, TX can appropriately change the cycle of the NFC tag detection process and the inquiry interval (inquiry time) from RX to TX according to the transmitted power. For example, taking the TX process in FIG. 10 as an example. The process of "transmitting the time until the next NFC tag detection" in S6114 is a process in a situation where the transmitted power exceeds the threshold (NO in S6110). Here, in addition to "transmitting the time until the next NFC tag detection", TX can also notify RX of the "inquiry time" from the next time, thereby changing the inquiry time. The corresponding RX obtains the information of "transmitting the time until the next NFC tag detection" and the "inquiry time" from the next time in the process of S5128. Then, RX can change the inquiry cycle by setting the timer start in the next S5119 to the obtained inquiry time. Also, TX can start the timer with the changed NFC detection cycle in the NFC timer start of S6128 or S6126. In the case of the third embodiment, TX can handle it only by changing the cycle of the NFC timer on the TX side.

[0160] Alternatively, TX can also variably control the cycle (execution waiting time), inquiry time, and / or time until NFC tag detection (remaining execution time) of the NFC tag detection process based on the GP determined in the negotiation phase. For example, TX can determine the cycle of the NFC tag detection process according to the value of GP and adjust the inquiry interval transmitted by ACAP according to that value.

[0161] In each of the above embodiments, the information on the "transmission suppression threshold" is transmitted to the RX in the negotiation phase, but it may also be transmitted to the RX in the transmission phase. The same applies to the "inquiry time" in the first and second embodiments. In this case, at least one of the "transmission suppression threshold" and the "inquiry time" may be transmitted to the RX in the transmission phase. Alternatively, either one of the "power during transmission suppression" and the "time of transmission suppression" may be transmitted in the negotiation phase and the other may be transmitted in the transmission phase.

[0162] In each of the above embodiments, the TX transmitted the GRQ (ACAP) after transmitting the SRQ (GP) of F413 in FIG. 4 (F415). However, the transmission timing of the GRQ (ACAP) may be any timing as long as it is after the ACK transmission of F408 in the negotiation phase. An example of such timing is, for example, between F412 and F4,13.

[0163] A part (or in some cases, all) of the configuration in the above embodiments may be replaced with another configuration that performs the same or similar functions, or omitted, or another configuration may be added. Also, it is applicable to various standards without being limited to the WPC standard.

[0164] Also, the power transmission device and the power reception device may be, for example, an image input device such as an imaging device (a still camera, a video camera, etc.) or a scanner, or an image output device such as a printer, a copier, a projector, etc. Further, it may be a storage device such as a hard disk device or a memory device, or an information processing device such as a personal computer (PC), a smartphone, a tablet device, etc.

[0165] Also, the power receiving device of the present disclosure may be an information terminal device. For example, the information terminal device has a display unit (display) that displays information for the user, to which the power received from the power receiving antenna is supplied. Note that the power received from the power receiving antenna is stored in a power storage unit (battery), and the power is supplied from the battery to the display unit. In this case, the power receiving device may have a communication unit that communicates with another device different from the power transmitting device. The communication unit may conform to communication standards such as NFC communication or the fifth generation mobile communication system (5G).

[0166] Also, the power receiving device of the present disclosure may be a vehicle such as an automobile. For example, an automobile as the power receiving device may receive power from a charger (power transmitting device) via a power transmitting antenna installed in a parking lot. Also, an automobile as the power receiving device may receive power from a charger (power transmitting device) via a power transmitting antenna embedded in a road. Such an automobile supplies the received power to a battery. The power of the battery may be supplied to a driving unit (motor, electric unit) that drives the wheels, or may be used to drive a sensor used for driving assistance or a communication unit that communicates with an external device. That is, in this case, the power receiving device may have, in addition to the wheels, a battery, a motor or a sensor driven using the received power, and further a communication unit that communicates with a device other than the power transmitting device. Furthermore, the power receiving device may have a housing unit that houses a person. For example, as the sensor, there is a sensor used for measuring the distance between vehicles or the distance to other obstacles. The communication unit may conform to, for example, the Global Positioning System (GPS). Also, the communication unit may conform to communication standards such as the fifth generation mobile communication system (5G). Also, as the vehicle, a bicycle or a motorcycle may be used.

[0167] In addition, the power receiving device of the present disclosure may be a power tool, a household appliance, or the like. These devices that are power receiving devices may have, in addition to a battery, a motor driven by the received power stored in the battery. Further, these devices may have a notification means for notifying the remaining amount of the battery or the like. Moreover, these devices may have a communication unit that communicates with another device different from the power transmission device. The communication unit may conform to a communication standard such as NFC or the fifth generation mobile communication system (5G).

[0168] In addition, the power transmission device of the present disclosure may be an in-vehicle charger that performs power transmission to a portable information terminal device such as a smartphone or a tablet that supports wireless power transmission inside a vehicle of an automobile. Such an in-vehicle charger may be provided anywhere inside the automobile. For example, the in-vehicle charger may be installed on the console of the automobile, or may be installed on the instrument panel (instrument panel, dashboard), at the position between the seats of the passengers, on the ceiling, or on the door. However, it is better not to install it in a place that hinders driving. Also, although the power transmission device has been described by way of example of an in-vehicle charger, such a charger is not limited to being arranged in a vehicle, and may be installed in a transportation machine such as a train, an airplane, or a ship. In this case, the charger may also be installed at the position between the seats of the passengers, on the ceiling, or on the door.

[0169] Also, a vehicle such as an automobile equipped with an in-vehicle charger may be a power transmission device. In this case, the power transmission device has wheels and a battery, and uses the power of the battery to supply power to the power receiving device by a power transmission circuit unit and a power transmission antenna.

[0170] It is also possible to supply a program that realizes one or more functions of the above-described embodiment to a system or a device via a network or a storage medium, and perform a process in which one or more processors in the computer of the system or the device read and execute the program. It is also possible to be realized by a circuit (for example, ASIC) that realizes one or more functions.

[0171] The disclosure of this embodiment includes the following configurations, methods, and programs. (Configuration 1) Negotiation means for negotiating with the power receiving device, Power transmission means for wirelessly transmitting power to the power receiving device based on the result of the negotiation, Processing means for executing a process including detection of an NFC (Near Field Communication) tag, Communication means for transmitting information related to NFC tag detection performed during power transmission to the power receiving device at least in the negotiation, and having A power transmission device characterized by the above. (Configuration 2) The processing means adjusts the power transmission power by the power transmission means based on the information related to the NFC tag detection, and executes the NFC tag detection in a state where the power transmission power is adjusted. The power transmission device according to Configuration 1, characterized by the above. (Configuration 3) The information related to the NFC tag detection includes information indicating a threshold value of the power transmission power for the processing means to start processing related to the adjustment of the power transmission power. The power transmission device according to Configuration 2, characterized by the above. (Configuration 4) The information related to the NFC tag detection further includes adjustment power information indicating the power transmission power at the time of adjustment and duration information indicating the time for continuing power transmission at the power transmission power at the time of adjustment. The processing means adjusts the power transmission power based on the adjustment power information and the duration information. The power transmission device according to Configuration 3, characterized by the above. (Configuration 5) The communication means transmits the adjustment power information and the duration information to the power receiving device after the power transmission power exceeds the threshold value. The power transmission device according to Configuration 4, characterized by the above. (Configuration 6) The information related to the NFC tag detection further includes information indicating an inquiry waiting time until the power receiving device executes an inquiry to the power transmission device. The target of the inquiry is information related to an execution waiting time from when the power transmission power exceeds the threshold value until the processing means executes the NFC tag detection. The power transmission device according to Configuration 3, characterized in that... (Configuration 7) The information regarding the NFC tag detection further includes adjustment power information indicating the power transmission power during the adjustment and duration information indicating the duration for which power transmission is continued at the power transmission power during the adjustment. The processing means adjusts the power transmission power based on the adjustment power information and the duration information. The power transmission device according to Configuration 6, characterized in that... (Configuration 8) The execution standby time includes the remaining execution time until the NFC tag detection is executed, which is set based on the communication means receiving the inquiry. The power transmission device according to Configuration 7, characterized in that... (Configuration 9) Before the execution standby time elapses, the communication means transmits information indicating the remaining execution time for the inquiry to the power receiving device for the inquiry. After the execution standby time elapses, the processing means adjusts the power transmission power. The power transmission device according to Configuration 8, characterized in that... (Configuration 10) Before the execution standby time elapses, the communication means transmits information indicating the remaining execution time for the inquiry to the power receiving device for the inquiry, and based on the power receiving device receiving the further inquiry executed based on the remaining execution time, the communication means further transmits the adjustment power information and the duration information to the power receiving device. The power transmission device according to Configuration 9, characterized in that... (Configuration 11) After the power transmission power exceeds the threshold value, the processing means sets the execution standby time until the processing means executes the NFC tag detection. After the execution standby time elapses, the communication means transmits the adjustment power information and the duration information to the power receiving device. The power transmission device according to Configuration 5, characterized in that... (Configuration 12) The processing means controls at least one of the execution standby time, the inquiry standby time, and the remaining execution time based on the transmission power. The power transmission device according to any one of Configurations 8 to 10, characterized in that. (Configuration 13) The processing means controls at least one of the execution standby time, the inquiry standby time, and the remaining execution time based on the guaranteed power determined in the negotiation. The power transmission device according to any one of Configurations 8 to 10, characterized in that. (Configuration 14) As an adjustment of the transmission power, the processing means reduces the transmission power or stops the power transmission. The power transmission device according to any one of Configurations 2 to 13, characterized in that. (Configuration 15) When the processing means stops the power transmission, it holds information regarding the state of the power receiving device, and after executing the NFC tag detection, resumes the power transmission based on the held information regarding the state of the power receiving device. The power transmission device according to Configuration 14, characterized in that. (Configuration 16) The information regarding the NFC tag detection includes information indicating a threshold value of the received power by the power receiving device for the processing means to start processing regarding the adjustment of the transmission power. The power transmission device according to Configuration 2, characterized in that. (Configuration 17) The power transmission device further includes a determination means for determining the threshold value based on the guaranteed power or the information of the power transmission profile determined in the negotiation. The power transmission device according to any one of Configurations 3 to 13, characterized in that. (Configuration 18) Negotiation means for negotiating with a power transmission device capable of executing a process including detection of an NFC (Near Field Communication) tag, Power receiving means for wirelessly receiving power from the power transmission device based on the result of the negotiation, At least in the negotiation, a communication means for receiving information regarding NFC tag detection performed during power transmission from the power transmission device A power receiving device characterized by the above. (Configuration 19) The information regarding NFC tag detection includes information indicating a threshold value of the power transmission for the power transmission device to start processing related to adjustment of the power transmission, and information indicating a query waiting time until the communication means executes a query to the power transmission device. The power transmission device adjusts the power transmission based on the information regarding NFC tag detection, and executes NFC tag detection in a state where the power transmission has been adjusted. After the query waiting time has elapsed, the communication means receives the remaining execution time until execution of the NFC tag detection, which is set and transmitted based on the fact that the query has been received by the power transmission device. The power receiving device according to Configuration 18, characterized by the above. (Configuration 20) The power transmission device adjusts the power transmission based on adjustment power information indicating the power transmission at the time of adjustment and continuous time information indicating the time for continuing power transmission at the power transmission at the time of adjustment, which are further included in the information regarding NFC tag detection. After the remaining execution time has elapsed, the power transmission device further has an adjustment means for adjusting the processing load of the power receiving device based on the adjustment power information and the continuous time information. The power receiving device according to Configuration 19, characterized by the above. (Configuration 21) Based on further receiving the query executed after the remaining execution time has elapsed by the power receiving device, the power transmission device further transmits the adjustment power information and the continuous time information to the power receiving device. The adjustment means adjusts the processing load based on the adjustment power information and the continuous time information transmitted from the power transmission device. The power receiving device according to Configuration 20, characterized by the above. (Configuration 22) The information related to the NFC tag detection includes information indicating a threshold value of the power transmission for the power transmission device to start processing related to the adjustment of the power transmission, adjustment power information indicating the power transmission during the adjustment, and duration information indicating the duration for which the power transmission is continued at the adjusted power transmission. The power transmission device sets an execution waiting time from when the power transmission exceeds the threshold value until the power transmission device executes the NFC tag detection. After the execution waiting time has elapsed, the adjustment power information and the duration information are transmitted to the power receiving device, the power transmission is adjusted based on the adjustment power information and the duration information, and the NFC tag detection is executed with the power transmission adjusted. The power receiving device further has an adjustment means for adjusting the processing load of the power receiving device based on the adjustment power information and the duration information transmitted from the power transmission device. The power receiving device according to Configuration 18, characterized by the above. (Configuration 23) As the adjustment of the power transmission, the power transmission device reduces the power transmission or stops the power transmission. When the power transmission is stopped, information regarding the state of the power receiving device is held, and when the power transmission is restarted after the NFC tag detection is executed, the power receiving device further has a restart means for restarting the power reception based on the held information regarding the state of the power receiving device. The power receiving device according to any one of Configurations 18 to 22, characterized by the above. (Method 1) A negotiation step of negotiating with a power receiving device; A power transmission step of wirelessly transmitting power to the power receiving device based on the result of the negotiation; A processing step of executing a process including detection of an NFC (Near Field Communication) tag; And a communication step of transmitting information related to the NFC tag detection performed during the power transmission to the power receiving device, at least in the negotiation step. A method performed by a power transmission device, characterized by the above. (Method 2) A negotiation step of negotiating with a power transmission device capable of executing a process including detection of an NFC (Near Field Communication) tag; Based on the result of the negotiation, a power receiving step of wirelessly receiving power from the power transmission device, and a communication step of receiving, at least in the negotiation step, information regarding NFC tag detection performed during power transmission from the power transmission device. A method performed by a power receiving device, characterized by the above. (Program) A program for operating a computer as the power transmission device according to any one of Configurations 1 to 17 or the power receiving device according to any one of Configurations 18 to 23.

[0172] As described above, the present disclosure has been described in detail based on its preferred embodiments. However, the present disclosure is not limited to the above embodiments, and various modifications are possible based on the gist of the present disclosure, and they are not excluded from the scope of the present disclosure.

Explanation of Reference Numerals

[0173] 101: Power receiving device 102: Power transmission device 201, 301: Control unit 203: WPC communication unit 204: Power receiving antenna 205: Power receiving unit 212, 310: Timer 303: Power transmission unit 305: Power transmission antenna 306: Communication unit 311: NFC communication unit 801: NFC tag

Claims

1. Negotiation means for negotiating with a power receiving device, Power transmission means for wirelessly transmitting power to the power receiving device based on the result of the negotiation, Processing means for executing a process including detection of an NFC (Near Field Communication) tag, Communication means for transmitting information related to NFC tag detection performed during power transmission to the power receiving device at least in the negotiation, and having A power transmission device characterized by this.

2. The processing means adjusts the power transmission power by the power transmission means based on the information related to the NFC tag detection, and executes the NFC tag detection in a state where the power transmission power is adjusted. The power transmission device according to claim 1, characterized by this.

3. The information related to the NFC tag detection includes information indicating a threshold value of the power transmission power for the processing means to start processing related to the adjustment of the power transmission power. The power transmission device according to claim 2, characterized by this.

4. The information related to the NFC tag detection further includes adjustment power information indicating the power transmission power at the time of adjustment and duration information indicating the time for continuing power transmission at the power transmission power at the time of adjustment. The processing means adjusts the power transmission power based on the adjustment power information and the duration information. The power transmission device according to claim 3, characterized by this.

5. The communication means transmits the adjustment power information and the duration information to the power receiving device after the power transmission power exceeds the threshold value. The power transmission device according to claim 4, characterized by this.

6. The information related to the NFC tag detection further includes information indicating an inquiry waiting time until the power receiving device makes an inquiry to the power transmission device. The subject of the inquiry is information related to an execution waiting time from when the power transmission power exceeds the threshold value until the processing means executes the NFC tag detection. The power transmission device according to claim 3, characterized by this.

7. The information related to the NFC tag detection further includes adjustment power information indicating the power transmission power at the time of adjustment and duration information indicating the time for continuing power transmission at the power transmission power at the time of adjustment. The processing means adjusts the power transmission power based on the adjustment power information and the duration information. The power transmission device according to claim 6, characterized by this.

8. The execution waiting time includes the remaining execution time until the NFC tag detection is executed, which is set based on the communication means receiving the inquiry. The power transmission device according to claim 7, characterized by this.

9. Before the execution waiting time elapses, the communication means transmits information indicating the remaining execution time for the inquiry to the power receiving device, and after the execution waiting time elapses, the processing means adjusts the transmission power. The power transmission device according to claim 8, characterized in that.

10. Before the execution waiting time elapses, the communication means transmits information indicating the remaining execution time for the inquiry to the power receiving device, and based on receiving the inquiry further executed by the power receiving device based on the remaining execution time, the adjustment power information and the duration information are further transmitted to the power receiving device. The power transmission device according to claim 9, characterized in that.

11. The processing means sets an execution waiting time from after the transmission power exceeds the threshold value until the processing means executes the NFC tag detection, and after the execution waiting time elapses, the communication means transmits the adjustment power information and the duration information to the power receiving device. The power transmission device according to claim 5, characterized in that.

12. Based on the transmission power, the processing means controls at least one of the execution waiting time, the inquiry waiting time, and the remaining execution time. The power transmission device according to claim 8, characterized in that.

13. Based on the guaranteed power determined in the negotiation, the processing means controls at least one of the execution waiting time, the inquiry waiting time, and the remaining execution time. The power transmission device according to claim 8, characterized in that.

14. As an adjustment of the transmission power, the processing means reduces the transmission power or stops the power transmission. The power transmission device according to claim 2, characterized in that.

15. When the processing means stops the power transmission, it holds information on the state of the power receiving device, and after executing the NFC tag detection, resumes the power transmission based on the held information on the state of the power receiving device. The power transmission device according to claim 14, characterized in that.

16. The information regarding the NFC tag detection includes information indicating a threshold value of the received power by the power receiving device for the processing means to start processing regarding the adjustment of the transmission power. The power transmission device according to claim 2, characterized in that.

17. It further has a determination means for determining the threshold value based on the guaranteed power or information on the power transmission profile determined in the negotiation. The power transmission device according to claim 3, characterized in that.

18. Negotiation means for negotiating with a power transmission device capable of executing a process including detection of an NFC (Near Field Communication) tag, Power receiving means for wirelessly receiving power from the power transmission device based on the result of the negotiation, Communication means for receiving, from the power transmission device, information regarding NFC tag detection performed during the power transmission, at least in the negotiation, and having: A power receiving device characterized by the above.

19. The information regarding the NFC tag detection includes information indicating a threshold value of the power transmission for the power transmission device to start a process related to adjustment of the power transmission, and information indicating a query waiting time until the communication means executes a query to the power transmission device, The power transmission device adjusts the power transmission based on the information regarding the NFC tag detection, and executes the NFC tag detection in a state where the power transmission is adjusted, The communication means receives, after the query waiting time has elapsed, the remaining execution time until the NFC tag detection is executed, which is set and transmitted based on the fact that the query has been received by the power transmission device. The power receiving device according to claim 18, characterized by the above.

20. The power transmission device adjusts the power transmission based on adjustment power information indicating the power transmission at the time of adjustment and continuous time information indicating the time for continuing power transmission at the power transmission at the time of adjustment, which are further included in the information regarding the NFC tag detection, After the remaining execution time has elapsed, the power receiving device further has adjustment means for adjusting the processing load of the power receiving device based on the adjustment power information and the continuous time information. The power receiving device according to claim 19, characterized by the above.

21. The power transmission device further transmits the adjustment power information and the continuous time information to the power receiving device based on the fact that the power transmission device has further received the query executed after the remaining execution time has elapsed by the power receiving device, The adjustment means adjusts the processing load based on the adjustment power information and the continuous time information transmitted from the power transmission device. The power receiving device according to claim 20, characterized by the above.

22. The information regarding the NFC tag detection includes information indicating a threshold value of the power transmission for the power transmission device to start a process related to adjustment of the power transmission, adjustment power information indicating the power transmission at the time of adjustment, and continuous time information indicating the time for continuing power transmission at the power transmission at the time of adjustment. The power transmission device sets an execution waiting time from when the transmitted power exceeds the threshold value until the power transmission device executes the NFC tag detection. After the execution waiting time has elapsed, the adjustment power information and the duration information are transmitted to the power receiving device, the transmitted power is adjusted based on the adjustment power information and the duration information, and the NFC tag detection is executed in a state where the transmitted power has been adjusted. The power receiving device further includes an adjustment means for adjusting the processing load of the power receiving device based on the adjustment power information and the duration information transmitted from the power transmission device. The power receiving device according to claim 18, characterized in that.

23. As the adjustment of the transmitted power, the power transmission device reduces the transmitted power or stops the power transmission. When the power transmission is stopped, information regarding the state of the power receiving device is held. When the power transmission is restarted after the NFC tag detection is executed, the power receiving device further includes a restart means for restarting power reception based on the held information regarding the state of the power receiving device. The power receiving device according to claim 18, characterized in that.

24. A negotiation step of negotiating with the power receiving device; A power transmission step of wirelessly transmitting power to the power receiving device based on the result of the negotiation; A processing step of executing a process including detection of an NFC (Near Field Communication) tag; And a communication step of transmitting information regarding the NFC tag detection performed during the power transmission to the power receiving device, at least in the negotiation step. A method performed by a power transmission device, characterized in that.

25. A negotiation step of negotiating with a power transmission device capable of executing a process including detection of an NFC (Near Field Communication) tag; A power reception step of wirelessly receiving power from the power transmission device based on the result of the negotiation; And a communication step of receiving, from the power transmission device, information regarding the NFC tag detection performed during the power transmission, at least in the negotiation step. A method performed by a power receiving device, characterized in that.

26. A program for operating a computer as the power transmission device according to any one of claims 1 to 17 or the power receiving device according to any one of claims 18 to 23.

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