Power transmission device and method

Abstract

To make it possible for a power reception device that performs communication on the basis of NFC standards to receive power properly.SOLUTION: When a power receiving device 200 detected through communication with a first communication unit 104 and a device that performs communication based on NFC standards detected through communication with a second communication unit 106 are determined to be the same device, a control unit 101 controls a power transmission unit 103 to transmit power at a higher level compared to when they are different devices.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a power transmission device, a method performed by the power transmission device, and a program. [Background technology]

[0002] BACKGROUND ART In recent years, technological development of wireless power transmission systems such as contactless charging systems has been widely carried out. Patent Document 1 discloses a power transmitting device and a power receiving device that comply with the standard (hereinafter referred to as the "WPC standard") established by the Wireless Power Consortium (WPC), a standardization organization for contactless charging.

[0003] Another type of wireless communication method is the Near Field Communication (NFC) method. The standards (specifications) established by the NFC Forum stipulate a card emulation mode in which a battery-powered NFC module behaves as if it were an NFC tag or NFC card (hereinafter collectively referred to as "NFC tag"). Other specifications include a reader / writer mode for reading NFC tags and a peer-to-peer mode for directly exchanging messages between NFC devices. Some WPC-compliant power receiving devices, such as smartphones, are equipped with NFC modules that operate in these modes and communicate based on the NFC standard. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-007116 Summary of the Invention [Problem to be solved by the invention]

[0005] An NFC tag does not have a battery and is powered by electromagnetic energy transmitted from a communication partner during communication. If high-power wireless power transmission from the above-described power transmitting device to this NFC tag occurs, the antenna element of the NFC tag may be damaged. To avoid this situation, the power transmitting device may limit power transmission when it detects an object communicating based on the NFC standard. However, such a configuration may cause the following problem. That is, when the power transmitting device detects an object communicating based on the NFC standard, the power transmitting device may limit power transmission regardless of whether the object is an NFC tag or a power receiving device communicating based on the NFC standard. Therefore, if power transmission to a power receiving device communicating based on the NFC standard is limited, the amount of received power may be insufficient.

[0006] An object of the present invention is to enable a power receiving device that performs communication based on the NFC standard to properly receive power. [Means for solving the problem]

[0007] A power transmitting device according to one aspect of the present invention includes a power transmitting unit that wirelessly transmits power to a power receiving device, a polling unit that performs polling using NFC communication, a detection unit that performs an NFC tag detection process, and a power receiving device that receives power from the power receiving device. composition The power receiving device includes a communication means for receiving information and a negotiation means for negotiating with the power receiving device, and the negotiation means determines negotiable power based on the result of the detection process. [Effects of the Invention]

[0008] According to the present invention, a power receiving device that performs communication based on the NFC standard can receive power appropriately. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a block diagram showing an example of the configuration of a power transmitting device according to an embodiment. [Figure 2]FIG. 2 is a block diagram showing an example of the configuration of a power receiving device according to the embodiment. [Figure 3] FIG. 2 is a diagram illustrating functional blocks of a power transmitting device according to an embodiment. [Figure 4] 10 is a flowchart of an NFC processing unit of the power transmitting device. [Figure 5] 10 is a flowchart of a WPC processing unit of the power transmitting device. [Figure 6] FIG. 3 is an operation sequence diagram of the wireless power transmission system according to the embodiment. [Figure 7] FIG. 3 is an operation sequence diagram of the wireless power transmission system according to the embodiment. [Figure 8] 10 is a flowchart of a WPC process in a power receiving device according to an embodiment. [Figure 9] FIG. 1 is a diagram showing an example of the configuration of a contactless charging system. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the following embodiments are merely examples for explaining the technical concept of the present invention, and are not intended to limit the present invention to the configurations and methods described in the embodiments.

[0011] (System configuration) FIG. 9 shows an example of the configuration of a contactless charging system (wireless power transmission system) according to this embodiment. This system includes a power transmitting device 100 and a power receiving device 200. Hereinafter, the power transmitting device may be referred to as TX, and the power receiving device may be referred to as RX. The TX100 and the RX200 comply with the WPC standard. The RX200 receives power from the TX100 and charges its battery. The TX100 is an electronic device that wirelessly transmits power to the RX200 placed on its own charging stand. The following description will be given using an example in which the RX200 is placed on the charging stand. However, for the TX100 to transmit power to the RX200, the RX200 does not need to be placed on the charging stand as long as it is within the power transmission range of the TX100 (the range indicated by the dashed line in FIG. 9).

[0012] Furthermore, the RX200 and the TX100 may have a function for executing applications other than contactless charging. An example of the RX200 is a smartphone, and an example of the TX100 is an accessory device for charging the smartphone. The RX200 and the TX100 may be a tablet, a storage device such as a hard disk drive or a memory device, or an information processing device such as a personal computer (PC). The RX200 and the TX100 may also be, for example, an imaging device (a camera, a video camera, etc.).

[0013] The RX200 is also equipped with a Near Field Communication (hereinafter referred to as "NFC") function, which can be used to read NFC tags and perform electronic money payments, for example. The TX100 is also equipped with an NFC function for reading NFC tags. This allows the TX100 to detect NFC tags by performing communication based on the NFC standard. Furthermore, the TX100 can stop or limit power transmission processing to protect the NFC tag based on the detection results.

[0014] This system performs wireless power transmission using an electromagnetic induction method for contactless charging based on the WPC standard. That is, the RX200 and the TX100 perform wireless power transmission for contactless charging based on the WPC standard between the power receiving antenna of the RX200 and the power transmitting antenna of the TX100. Note that the wireless power transmission method (contactless power transmission method) applied to this system is not limited to the method specified by the WPC standard, and may be other methods such as electromagnetic induction, magnetic field resonance, electric field resonance, microwave, or laser. Furthermore, in this embodiment, wireless power transmission is used for contactless charging, but wireless power transmission may also be performed for purposes other than contactless charging.

[0015] In the WPC standard, the amount of power guaranteed when the RX200 receives power from the TX100 is defined by a value called Guaranteed Power (hereinafter referred to as "GP"). GP indicates the power value that is guaranteed to be output to the RX200's load (e.g., a charging circuit) even if the relative positions of the RX200 and TX100 change and the power transmission efficiency between the receiving antenna and the transmitting antenna decreases. For example, if the GP is 5 watts, the TX100 will transmit power by controlling it so that it can output 5 watts to the load within the RX200, even if the relative positions of the receiving antenna and the transmitting antenna change and the power transmission efficiency decreases.

[0016] The RX200 and TX100 according to this embodiment communicate for power transmission and reception control based on the WPC standard. The WPC standard defines multiple phases, including a power transfer phase in which power transmission is performed and a phase before the actual power transmission, and communication for the necessary power transmission and reception control is performed in each phase. Phases before power transmission include a selection phase, a ping phase, an identification and configuration phase, a negotiation phase, and a calibration phase. Note that the identification and configuration phase will be referred to as the I&C phase below.

[0017] In the Selection phase, the TX100 transmits Analog Pings intermittently to detect that an object has been placed on the charging base of the TX100 (for example, that the RX200 or a piece of conductor has been placed on the charging base). The TX100 detects at least one of the voltage and current values ​​of the power transmitting antenna when it transmits Analog Pings, and if the voltage value is below a certain threshold or the current value exceeds a certain threshold, it determines that an object is present and transitions to the Ping phase.

[0018] In the Ping phase, the TX100 transmits a Digital Ping, which has a higher power than the Analog Ping. The power of the Digital Ping is sufficient to start up the control unit of the RX200 placed on the charging base of the TX100. The RX200 notifies the TX100 of the magnitude of the received power voltage. In this way, the TX100 recognizes that the object detected in the Selection phase is the RX200 by receiving a response from the RX200 that received the Digital Ping.

[0019] When the TX100 receives notification of the received voltage value, it transitions to the I&C phase. In the I&C phase, the TX100 identifies the RX200 and acquires device configuration information (capability information) from the RX200. To do this, the RX200 transmits an ID packet and a configuration packet to the TX100. The ID packet contains the RX200's identifier information, and the configuration packet contains the RX200's device configuration information (capability information). Upon receiving the ID packet and configuration packet, the TX100 responds with an acknowledgement (ACK, positive response). The I&C phase then ends.

[0020] In the negotiation phase, the GP value is determined based on the GP value requested by the RX200 and the power transmission capability of the TX100.

[0021] In the calibration phase, the RX200 notifies the TX100 of the received power value based on the WPC standard, and the TX100 makes adjustments to transmit power efficiently.

[0022] In the power transfer phase, control is performed to start and continue power transmission, as well as to stop power transmission due to an error or full charge.

[0023] To control power transmission and reception, the TX100 and RX200 use the same antenna (coil) as for wireless power transmission based on the WPC standard to perform communication (hereinafter referred to as "first communication") by superimposing a signal on the electromagnetic waves transmitted from the antenna. Note that the range in which the first communication based on the WPC standard is possible between the TX100 and RX200 is approximately the same as the power transmission range of the TX100 (the range indicated by the dashed line in Figure 9).

[0024] The TX100 and RX200 may perform communication for power transmission and reception control using a different antenna and frequency (hereinafter referred to as "second communication") from that used for wireless power transmission. For example, the electromagnetic waves used for the second communication may be in a higher frequency band than the electromagnetic waves used for the first communication. In this case, using the second communication makes it possible to perform communication at a higher speed than using the first communication.

[0025] An example of the second communication is a communication method conforming to the Bluetooth (registered trademark) Low Energy (hereinafter referred to as "BLE") standard. In this case, the TX100 operates in the role of a BLE Peripheral, and the RX200 operates in the role of a BLE Central, but these BLE roles may be reversed. The second communication may also be performed by other communication methods such as wireless LAN (e.g., Wi-Fi (registered trademark)) of the IEEE802.11 standard series or ZigBee. Note that when the TX100 is capable of performing the second communication and the RX200 is present within a power transmission range, the RX200 and TX100 can exchange information via the second communication.

[0026] (Device configuration) Next, the configurations of the power transmitting device 100 (TX100) and the power receiving device 200 (RX200) according to this embodiment will be described. Note that the configurations described below are merely examples, and a part (or in some cases the whole) of the described configurations may be replaced with other configurations that perform similar functions or may be omitted, or additional configurations may be added to the described configurations. Furthermore, one block shown in the following description may be divided into multiple blocks, or multiple blocks may be integrated into one block.

[0027] Fig. 1 is a block diagram showing an example of the configuration of a TX 100 according to this embodiment. The TX 100 has a control unit 101, a power supply unit 102, a power transmitting unit 103, a first communication unit 104, a power transmitting antenna 105, a second communication unit 106, and a memory 107. In Fig. 1, the control unit 101, the power supply unit 102, the power transmitting unit 103, the first communication unit 104, the second communication unit 106, and the memory 107 are depicted as separate entities, but any two or more of these blocks may be implemented on the same chip.

[0028] The control unit 101 controls the entire TX 100 by executing a control program stored in the memory 107, for example. The control unit 101 also controls power transmission control, including communication for device authentication in the TX 100. The control unit 101 may also control the execution of applications other than wireless power transmission. The control unit 101 includes one or more processors, such as a Central Processing Unit (CSU) or a Microprocessor Unit (MPU). The control unit 101 may also be configured with dedicated hardware for specific processing, such as an Application Specific Integrated Circuit (ASIC). The control unit 101 may also be configured with an array circuit, such as a Field Programmable Gate Array (FPGA), compiled to execute specific processing. The control unit 101 stores information to be stored during the execution of various processes in the memory 107. The control unit 101 may also measure time using a timer (not shown).

[0029] The power supply unit 102 supplies power to each block. The power supply unit 102 is, for example, a commercial power supply or a battery. The battery stores power supplied from the commercial power supply.

[0030] The power transmitting unit 103 converts DC or AC power input from the power supply unit 102 into AC frequency power in a frequency band used for wireless power transmission, and inputs the AC frequency power to the power transmitting antenna 105 to generate electromagnetic waves for receiving power at the RX200. For example, the power transmitting unit 103 converts the DC voltage supplied by the power supply unit 102 into an AC voltage using a switching circuit with a half-bridge or full-bridge configuration using FETs (Field Effect Transistors). In this case, the power transmitting unit 103 includes a gate driver that controls the ON / OFF of the FETs.

[0031] The power transmitting unit 103 controls the intensity of the electromagnetic waves to be output by adjusting the voltage (power transmission voltage) or current (power transmission current), or both, input to the power transmitting antenna 105. Increasing the power transmission voltage or power transmission current increases the intensity of the electromagnetic waves, and decreasing the power transmission voltage or power transmission current decreases the intensity of the electromagnetic waves. Furthermore, the power transmitting unit 103 controls the output of AC frequency power so as to start or stop power transmission from the power transmitting antenna 105 based on instructions from the control unit 101. Furthermore, the power transmitting unit 103 is assumed to be capable of supplying 15 watts of power to the charging unit of the RX200 in accordance with the WPC standard.

[0032] The first communication unit 104 performs communication with the RX200 for power transmission control based on the WPC standard as described above. The first communication unit 104 modulates electromagnetic waves output from the power transmitting antenna 105 and transmits information to the RX200 to perform the first communication. The first communication unit 104 also demodulates the electromagnetic waves output from the power transmitting antenna 105 and modulated by the RX200 to acquire information transmitted by the RX200. That is, the first communication performed by the first communication unit 104 is performed by superimposing a signal on the electromagnetic waves transmitted from the power transmitting antenna 105. The first communication unit 104 may also perform communication with the RX200 using the second communication instead of the first communication, or may also perform communication with the RX200 by selectively using the first communication and the second communication. When the first communication unit 104 performs the second communication, the TX100 has an antenna different from the power transmitting antenna 105.

[0033] The second communication unit 106 communicates with other NFC devices using the NFC function. In this embodiment, NFC devices also include NFC tags unless otherwise specified. The second communication unit 106 enables the TX 100 to detect the presence of an NFC tag. When the second communication unit 106 detects an NFC tag, the control unit 101 controls the power transmitting unit 103 to stop power transmission or to limit power transmission by, for example, lowering the power of the power transmission. The second communication unit 106 has an antenna (not shown) different from the power transmitting antenna 105.

[0034] Furthermore, the second communication unit 106 is controlled by the control unit 101, but may be configured to be controlled by a control unit of another device (camera, smartphone, tablet PC, laptop) (not shown) that incorporates the TX100.

[0035] The memory 107 stores the control program as well as the status of the TX100 and RX200.

[0036] Fig. 2 is a block diagram showing an example of the configuration of the RX 200 according to this embodiment. The RX 200 includes a control unit 201, a second communication unit 202, a power receiving unit 203, a first communication unit 204, a power receiving antenna 205, a charging unit 206, a battery 207, and a memory 208. Note that the multiple blocks shown in Fig. 2 may be implemented as a single hardware module.

[0037] The control unit 201 controls the entire RX200 by executing a control program stored in the memory 208, for example. That is, the control unit 201 controls each functional unit shown in FIG. 2. Furthermore, the control unit 201 may perform control for executing applications other than wireless power transmission. An example of the control unit 201 is configured to include one or more processors such as a CPU or MPU. Note that the entire smartphone may be controlled in cooperation with an OS (Operating System) executed by the control unit 201.

[0038] The control unit 201 may also be configured with hardware dedicated to a specific process, such as an ASIC. The control unit 201 may also be configured to include an array circuit, such as an FPGA, compiled to execute a predetermined process. The control unit 201 stores information to be stored while executing various processes in the memory 208. The control unit 201 may also measure time using a timer (not shown).

[0039] The second communication unit 202 performs communication processing with other communication devices using an NFC function. The second communication unit 202 operates, for example, in a mode that complies with the standards established by the NFC Forum. The above modes include, for example, a card emulation mode that acts as a contactless IC card, a reader / writer mode for reading NFC tags, and a P2P mode that directly exchanges messages between NFC devices. For example, the card emulation mode enables electronic money payments and the like. Note that P2P mode is an abbreviation for Peer to Peer mode.

[0040] To perform communication based on the NFC standard, the second communication unit 202 has an antenna (not shown) different from the power receiving antenna 205. The second communication unit 202 is controlled by the control unit 201, but may be configured to be controlled by a control unit of another device (camera, smartphone, tablet PC, laptop PC) (not shown) that has a built-in RX200.

[0041] The power receiving unit 203 acquires, at the power receiving antenna 205, AC power (AC voltage and AC current) generated by electromagnetic induction caused by electromagnetic waves radiated from the power transmitting antenna 105 of the TX100. The power receiving unit 203 then converts the AC power into DC power or AC power of a predetermined frequency, and outputs the power to the charging unit 206, which performs processing to charge the battery 207. In other words, the power receiving unit 203 supplies power to the load in the RX200. The above-mentioned GP is the amount of power guaranteed to be output from the power receiving unit 203. The power receiving unit 203 supplies power for the charging unit 206 to charge the battery 207, and is assumed to have the capacity to supply enough power to output 15 watts of power to the charging unit 206.

[0042] The first communication unit 204 performs communication for power reception control based on the WPC standard as described above with the first communication unit 104 included in the TX100. The first communication unit 204 demodulates the electromagnetic waves input from the power receiving antenna 205 to acquire information transmitted from the TX100. The first communication unit 204 then performs first communication with the TX100 by load modulating the input electromagnetic waves to superimpose a signal related to information to be transmitted to the TX100 on the electromagnetic waves. The first communication unit 204 may communicate with the TX100 using second communication instead of the first communication, or may communicate with the TX100 by selectively using the first communication and the second communication. Note that when the first communication unit 204 performs the second communication, the RX200 has an antenna different from the power receiving antenna 205.

[0043] The memory 208 stores the control program as well as the status of the TX100 and RX200.

[0044] Next, a functional block diagram of the control unit 101 of the TX100 will be described with reference to Fig. 3. The control unit 101 has a WPC processing unit 301 and an NFC processing unit 302. The WPC processing unit 301 is a processing unit that performs control communication of wireless power transmission based on the WPC standard via the first communication unit 104. The WPC processing unit 301 also controls the power transmitting unit 103 and controls power transmission to the RX200. The NFC processing unit 302 is a processing unit that performs communication related to the NFC standard via the second communication unit 106. The WPC processing unit 301 and the NFC processing unit 302 operate in parallel as independent programs, and their functions are implemented by the control unit 101 executing these programs.

[0045] Next, the processing procedures performed by the NFC processing unit 302 and the WPC processing unit 301 in the TX 100 will be described with reference to FIGS.

[0046] [Processing by NFC processing unit] 4 is a flowchart showing the processing operation of the NFC processing unit 302. This processing is continuously and repeatedly executed while the TX 100 is running.

[0047] When the TX100 starts up, the second communication unit 106 starts the NFC polling process (S401). Specifically, the second communication unit 106 monitors the proximity of other NFC devices by sending a polling request and monitoring the response. If an error is detected as a result of the polling process (Yes in S402), the NFC processing unit 302 notifies the WPC processing unit 301 that an error has occurred in the NFC process (S403). The error here refers to a failure of communication related to the NFC standard, and does not include the absence of a response to a polling request, i.e., the absence of a communication partner NFC device. One example of an error is a so-called collision error, which occurs when multiple other NFC devices present within the communication range of communication related to the NFC standard respond at the same time and the response data cannot be received correctly.

[0048] When such an error occurs, normal NFC communication with other NFC devices within the communication range cannot be performed, and it is therefore impossible to confirm whether the detected NFC devices include a battery-less NFC tag. Therefore, the NFC processing unit 302 notifies the WPC processing unit 301 that an NFC tag may be nearby, and the WPC processing unit 301, upon receiving this notification, suppresses power transmission processing at high power, thereby reducing the possibility of damaging the NFC tag.

[0049] If no error is detected as a result of the polling process (No in S402), the NFC processing unit 302 notifies the WPC processing unit 301 that there is no error in the NFC process (S404). Note that even if the error is resolved, the NFC processing unit 302 notifies the WPC processing unit 301 that there is no error in the NFC process.

[0050] Next, the NFC processing unit 302 determines whether or not there is a specific response to the Polling request sent in S401 (S405). The specific response is a response indicating that the device does not support P2P mode. If there is no specific response (No in S405), the NFC processing unit 302 notifies the WPC processing unit 301 that there is no specific NFC device in the vicinity (S406). Alternatively, the NFC processing unit 302 may be configured to notify that there is no specific NFC device in the vicinity only if there is no specific response to multiple consecutive Polling requests.

[0051] Note that the specific NFC device refers to an NFC tag, a device that does not support P2P mode, or a device that supports P2P mode but operates in reader / writer mode. Note that a device operating in reader / writer mode does not respond to a polling request, regardless of whether it supports P2P mode. Therefore, if the NFC processing unit 302 cannot detect a device operating in reader / writer mode and only a device operating in reader / writer mode is placed on the charging stand, the NFC processing unit 302 determines No in S405.

[0052] Furthermore, the absence of a specific response refers to the following cases: when there is no device that communicates according to the NFC standard; when an NFC device exists but does not respond to a polling request; or when the device responds to a polling request but supports P2P mode. A device that supports P2P mode refers to a case where the NFC device can operate in P2P mode. For example, an NFC device that operates in card emulation mode but supports P2P mode is also said to support P2P mode. Note that if a device supports P2P mode, the response data to the polling request contains information indicating that it supports P2P mode. Therefore, the NFC processing unit 302 can determine whether the detected NFC device supports P2P mode based on the response data.

[0053] On the other hand, if there is a specific response (Yes in S405), the NFC processing unit 302 repeats the processes of S407 to S411 for the number of received responses. For each piece of received response data, the NFC processing unit 302 acquires identifier information of each NFC device included in the data (hereinafter may be referred to as "NFC identifier information") (S408). Note that here, the NFC identifier information of the NFC device that responded is acquired regardless of whether the response to the Polling request is a specific response or not. Note that the NFC processing unit 302 can detect the presence of an NFC device in the vicinity based on the presence or absence of a response.

[0054] The NFC identifier information is identifier information that can uniquely identify other NFC devices present within the NFC communication range, and in this embodiment, it is IDm data used in FeliCa (registered trademark) technology. Note that the NFC standard defines an area called IDm as the format of communication data, and the content of the data specified in this IDm area is defined by the FeliCa standard. Therefore, in this embodiment, IDm data used in FeliCa technology is used. However, the NFC identifier information is not limited to this, as will be described later.

[0055] If the NFC identifier information is successfully acquired (Yes in S409), the NFC processing unit 302 notifies the WPC processing unit 301 of the acquired NFC identifier information (S410). If the NFC identifier information is not successfully acquired (No in S409), the NFC processing unit 302 notifies the WPC processing unit 301 that an error has occurred in the NFC processing (S411).

[0056] After performing the process of acquiring the NFC device identifiers included in all response data (S408 to S411), the NFC processing unit 302 compares the NFC identifier information acquired in the previous NFC process with the NFC identifier information acquired in the current NFC process. If the comparison shows that some of the NFC identifier information acquired previously could not be acquired this time (Yes in S412), the NFC processing unit 302 notifies the WPC processing unit 301 that there is no more NFC identifier information and sends that NFC identifier information to the WPC processing unit 301 (S413). Furthermore, if identifier acquisition failed in the previous polling process but not in the current polling process, the NFC processing unit 302 notifies the WPC processing unit 301 that the error in the NFC processing has been resolved.

[0057] Although the NFC processing unit 302 is described as sequentially notifying the WPC processing unit 301 of error conditions in the NFC processing and the acquired NFC identifier information, this NFC processing is not limited to this. Notification to the WPC processing unit 301 may be sent all at once after all processing has been performed. Notifications to the WPC processing unit 301 include a notification of an error occurrence (S402), a notification of non-detection of response data (S405), a notification of the acquired NFC identifier information (S410), and a notification of failure to acquire NFC identifier information (S411). Alternatively, the acquired NFC identifier information may be listed and notified to the WPC processing unit 301.

[0058] [Processing by WPC Processing Unit] 5 is a flowchart showing the processing operation of the WPC processing unit 301. This processing is also repeatedly executed continuously while the TX 100 is running.

[0059] When the TX100 starts up, the WPC processing unit 301 performs selection phase processing (S501). Specifically, an analog ping is transmitted via the power transmitting unit 103 and the power transmitting antenna 105. The TX100 detects at least one of the voltage value and current value of the power transmitting antenna 105 when the analog ping is transmitted. If the voltage is below a certain threshold or the current value exceeds a certain threshold, the TX100 determines that an object is present near the power transmitting antenna 105 and transitions to the ping phase.

[0060] In the Ping phase process of S502, the TX100 transmits a Digital Ping that is larger than the Analog Ping. The magnitude of the Digital Ping is at least sufficient power to activate the control unit 201 of the RX200 that is present near the power transmitting antenna 105. Subsequently, when the TX100 receives a receiving voltage notification that notifies the magnitude of the receiving voltage from the RX200, the TX100 transitions to the I&C phase. By receiving this receiving voltage notification via the first communication unit 104, the TX100 can recognize that the object placed on the charging stand is the RX200.

[0061] In the I&C phase, the TX 100 receives an ID packet transmitted from the RX 200 (S503). The TX 100 also references the information bit (Ext bit) included in the ID packet to determine whether additional identifier information is transmitted from the RX 200 (S504).

[0062] If the Ext bit is 1 (Yes in S504), the TX100 determines that additional identifier information will be transmitted, waits for an Extended Identification Packet transmitted from the RX200, and receives that packet (S505). This packet contains an Extended Device Identifier of the RX200 of up to 8 octets. The TX100 stores this additional identifier information in the memory 107 as NFC identifier information (S506). In other words, this additional identifier information differs from the identifier information contained in the ID packet and is stored in the memory 107 as NFC identifier information acquired in the NFC processing.

[0063] Next, the TX 100 receives a configuration packet transmitted from the RX 200 (S507). The TX 100 references the information bit (Neg bit) contained in this packet and determines whether to transition to the negotiation phase (S508).

[0064] In the Negotiation phase, the TX100 negotiates with the RX200 to determine the GP. If the Neg bit is 0 (No in S508), the TX100 transmits an ACK packet to the RX200 (S509). At this time, the TX100 does not transition to the Negotiation phase, but transitions to the Power Transfer phase (S510), and performs power transmission processing to the RX200 at low power. The low power here refers to a transmission power output value that is determined not to damage the NFC tag even if the TX100 performs power transmission processing. This low power may be, for example, an arbitrarily set value, or may be a value set based on at least one of the power, current, and voltage defined by the WPC standard or other standards.

[0065] If the Neg bit is 1 (Yes in S508), the TX100 transmits an ACK packet to the RX200 (S511) and transitions to the negotiation phase. In the processing in the negotiation phase (S512 to S524), the TX100 waits for a specific request packet or a general request packet to be transmitted from the RX200.

[0066] When the TX100 receives a Specific Request Packet (Yes in S512), it determines whether the GP value specified in this packet is acceptable (S513 to S518). The Specific Request Packet contains a candidate value for the power (GP) requested by the RX200. The TX100 first determines whether the specified GP value is equal to or less than a preset threshold (S513). The threshold here is the threshold for the power output that is determined not to cause damage to the NFC tag even if power transmission processing is performed. If the specified GP value is equal to or less than the threshold (No in S513), the TX100 accepts the specified GP value and transmits an ACK Packet to the RX200 (S517).

[0067] If the specified GP value is equal to or greater than the threshold value (Yes in S513), the TX100 determines whether an error has occurred in the NFC processing (S514). Specifically, the WPC processing unit 301 determines whether the NFC processing unit 302 has notified it of the occurrence of an error (S413, S411 in FIG. 4). If an error has occurred in the NFC processing (Yes in S514), there is a possibility that an NFC tag is present within the communication range of the TX100. Therefore, the TX100 rejects the requested GP value that is equal to or greater than the threshold value and transmits a NAK packet to the RX200 (S518). After that, the TX100 continues to wait for a Specific Request Packet or a General Request Packet.

[0068] For example, if no error has occurred in the NFC processing (No in S514), the TX 100 determines whether or not there is an NFC device that has sent a specific response to the polling request (S515). Specifically, the WPC processing unit 301 makes this determination based on whether or not the NFC processing unit 302 has notified it that there is no specific NFC device (S406 in FIG. 4).

[0069] If there is no specific NFC device that has responded to the Polling request (No in S515), the TX100 accepts the specified GP value and sends an ACKPacket to the RX200 (S517).

[0070] If there is a specific NFC device that has responded to the Polling request (Yes in S515), the TX100 determines whether the NFC device detected in the NFC processing and the RX200 detected in the WPC processing are the same device. Specifically, the WPC processing unit 301 compares the NFC identifier information notified from the NFC processing unit 302 with the additional identifier information stored in the processing of S506, and determines whether these pieces of identifier information match (S516). If the identifier information matches, the WPC processing unit 301 determines that the NFC device detected in the NFC processing and the RX200 detected in the WPC processing are the same device.

[0071] If it is determined that the devices are the same (Yes in S516), the TX100 accepts the specified GP value and transmits an ACK Packet to the RX200 (S517). In this case, the TX100 determines that the RX200 has a power source for executing WPC communication processing and that some power is also being supplied to the module that executes the NFC function of the RX200. Therefore, the TX100 determines that even if power transmission processing is performed with an output above the threshold, it will not cause damage to the NFC device detected by the NFC processing unit 302, and accepts the GP value specified by the RX.

[0072] If the NFC device detected in the NFC processing and the RX200 detected in the WPC processing are not the same (No in S516), the TX100 rejects the requested GP value that is equal to or greater than the threshold, and transmits a NAK packet to the RX200 (S518). Because the NFC tag is not the RX200, the WPC processing shown in FIG. 5 is not executed, and NFC identifier information is not transmitted to the TX100. Therefore, it is determined that the NFC device detected in the NFC processing and the RX200 detected in the WPC processing are not the same. After that, the TX100 continues to wait for a Specific Request Packet or a General Request Packet.

[0073] If there is a plurality of pieces of NFC identifier information notified by the NFC processing unit 302, and if the processing in S506 has not stored the additional identifier information corresponding to all of the NFC identifier information, a NAK packet is transmitted to the RX200 (S518). In other words, if there is any identifier among the plurality of identifiers notified by the NFC processing unit 302 for which the corresponding additional identifier information is not stored in S506, a NAK packet is transmitted to the power receiving device 200. On the other hand, if the processing in S506 has stored the additional identifier information corresponding to all of the NFC identifier information notified by the NFC processing unit 302, an ACK packet is transmitted to the RX200 (S517).

[0074] Next, a case will be described in which the TX 100 receives a General Request Packet. The TX 100 receives a packet from the General Request Packet that requests notification of the TX 100's capabilities (Power Transmitter capacity) (No in S512, Yes in S519). In this case, a determination process is performed to determine the GP value to be notified to the RX200 in the response packet of this packet (S520 to S524).

[0075] The TX100 first determines whether an error has occurred in the NFC processing (S520). The method of determination is the same as the processing of S514. If an error has occurred in the NFC processing (Yes in S520), the TX100 responds with a GP value, which is a transmission power output value that can be determined not to damage the NFC tag even if the power transmission processing is performed (S524). Here, the response is GP = 0.5 watts. Note that this GP value is not limited to 0.5 watts, and it may be any power value that does not damage the NFC tag. Also, this GP value may be 0 watts, or a notification may be sent that power transmission will not be performed.

[0076] If no error has occurred in the NFC processing (No in S520), the TX100 determines whether or not there is a specific NFC device that has responded to the Polling request (S521). The determination method is the same as the processing in S515. If there is no specific NFC device that has responded to the Polling request (No in S521), the TX100 responds with the maximum transmission power output value defined in the WPC standard among the capabilities of the power transmitting unit 103 as the GP value (S523). In this case, the GP is responded as 15 watts. This GP value is an example and is not limited to this.

[0077] If there is a specific NFC device that has responded to the Polling request (Yes in S521), the TX100 determines whether the NFC device detected in the NFC process and the RX200 detected in the WPC process are the same device (S522). The method of determination is the same as the process in S516.

[0078] If it is determined that the devices are the same (Yes in S522), the TX100 responds as GP with the maximum power transmission output value defined in the WPC standard among the capabilities of the power transmitting unit 103 (S523). On the other hand, if it is determined that the devices are not the same (No in S516), the TX100 responds as GP with a power transmission output value that it determines will not damage the NFC tag even if power transmission processing is performed (S524). In other words, if it is determined that the devices are the same, the TX100 sets a larger GP than if it is determined that the devices are not the same, and transmits power based on this GP.

[0079] When the TX100 receives a Specific Request Packet from the RX200 requesting the end of the Negotiation phase, it transitions to the Calibration phase (S525). In the Calibration phase, the TX100 determines the parameters required for the foreign object detection function that detects the presence of an object other than the RX200 near the power receiving antenna 205. The TX100 adjusts the power transmission output so that the RX200 can be charged by the GP approved in S517 or the GP that responded in S523 or S524.

[0080] Thereafter, the TX 100 transitions to the Power Transfer phase (S526) and supplies power to the charging unit 206 of the RX 200. The TX 100 continues the power transmission process until it receives an End Power Transfer Packet from the RX 200.

[0081] [WPC processing in RX] Next, the operational procedure of the WPC process in the RX200 will be described with reference to Fig. 8. This process is repeatedly executed while the RX200 is set to execute the charging function by WPC.

[0082] The control unit 201 of the RX200 receives a Digital Ping sent from the TX100 (Yes in S801) and detects that the TX100 is nearby (S802). In response, the control unit 201 acquires NFC setting and operation information for the second communication unit 202 (S803). The setting and operation information here includes a status indicating whether the NFC function of the RX200 is enabled or disabled, the NFC operation mode, and NFC identifier information that can uniquely identify the NFC device. The NFC operation mode here refers to the NFC operation mode of the second communication unit 202, and indicates one of the three modes: card emulation mode, reader / lider mode, and P2P mode. Next, the control unit 201 notifies the TX100 of the received voltage of the Digital Ping via the first communication unit 204 using a Signal Strength Packet (S804).

[0083] Next, the control unit 201 selects the next packet to transmit according to the NFC communication setting and operation information acquired in S803. Specifically, if the NFC function is enabled and the NFC operation mode is card emulation mode (Yes in S805), the control unit 201 transmits an ID packet to the TX 100 (S807). Here, the Ext bit in the ID packet to be transmitted is set to 1, and the TX 100 is notified that an Extended Identification Packet will be transmitted subsequently.

[0084] Next, the control unit 201 sets the NFC identifier information acquired in S803 in an Extended Identification Packet and transmits it to the TX 100 (S808).

[0085] Furthermore, if the NFC function is disabled, or if the NFC function is enabled but the operating mode is not card emulation mode (No in S805), the control unit 201 does not transmit an Extended Identification Packet. That is, it transmits an Identification Packet with the Ext bit set to 0 to the TX100 (S806). In this way, by determining whether or not to transmit a packet depending on the operating state of the NFC function in the RX200, it is possible to suppress unnecessary communication. This makes it possible to reduce power consumption in both the TX100 and the RX200.

[0086] Next, the control unit 201 transmits a configuration packet to the TX100 (S809) and requests the TX100 to transition to the negotiation phase, where negotiations are carried out to determine the GP. When the RX200 receives an ACK packet from the TX100 (Yes in S810), it transitions to the negotiation phase. Note that if the ACK packet is not received for a certain period of time (No in S810), the RX200 transitions to the selection phase and returns the processing state to the digital ping standby processing.

[0087] When the phase transitions to the negotiation phase, the control unit 201 transmits a specific request packet specifying 15 watts as a GP candidate to the TX 100 (S811). When the RX 200 receives an ACK packet from the TX 100 (Yes in S812), it determines that the GP of 15 watts has been granted by the TX 100, and the GP for the power reception process is determined to be 15 watts (S813).

[0088] Furthermore, when the RX200 receives a NAK packet from the TX100 (No in S812, Yes in S814), it determines that the 15-watt GP has been rejected by the TX100. In this case, the RX200 sends a General Request Packet to the TX100 (S815) to request a GP candidate for the TX100. When the RX200 receives a Power Transmitter Capability Packet from the TX100 (S816), the GP candidate value for the TX100 contained in this packet is determined as the GP for this charging process (S817).

[0089] Also, if neither an ACK packet nor a NAK packet is received (No in S814), the RX200 transitions to the Selection phase and returns the processing state to the Digital Ping standby processing.

[0090] When the GP negotiation is completed, the TX100 and the RX200 transition to the calibration phase (S818). In the calibration phase, the TX100 determines parameters necessary for the foreign object detection function that detects the presence of an object other than the RX200 near the power receiving antenna 205. Also, in the calibration phase, the RX200 performs processing to supply power from the power receiving unit 203 to the charging unit 206, which acts as a load.

[0091] Thereafter, the TX100 and RX200 transition to the power transfer phase, and the RX200 charges the battery 207 (S819). When charging is completed (Yes in S820), the RX200 transmits an End Power Transfer Packet to the TX100 (S821) to notify the TX100 of the completion of the charging process.

[0092] [Sequence of wireless power transmission system] Next, a sequence of a wireless power transmission system including the TX100 and the RX200 will be described with reference to Fig. 6. Fig. 6 shows an example of a communication sequence between the TX100 and the RX200 when the RX200 is placed close to the TX100.

[0093] First, it is assumed that the RX200 operates the NFC function of the second communication unit 202 in card emulation mode (S601).

[0094] Meanwhile, the NFC processing unit 302 of the TX100 periodically performs polling processing according to the NFC standard (S602). When the RX200 approaches within the NFC communication range, a response to the polling request is made, and the NFC processing unit 302 detects that an NFC device has approached (S603). The NFC processing unit 302 reads the NFC identifier information from the polling response and notifies the WPC processing unit 301 (S604).

[0095] Furthermore, the WPC processing unit 301 of the TX 100 periodically transmits an Analog Ping (S605), and if it determines that an object exists near the power transmitting antenna 105, it transmits a Digital Ping (S606).

[0096] The RX200 detects the TX100 by receiving a Digital Ping (S607). The RX200 then acquires NFC setting and operation information (S608). The NFC setting information here includes status information on whether the RX200's NFC function is enabled or disabled, the NFC operation mode, and NFC identifier information. In this example, it is assumed that the information acquired is "NFC function = enabled," "operation mode = card emulation mode," and "NFC identifier information = FeliCa IDm information." The RX200 then notifies the TX100 of the received power voltage of the Digital Ping using a Signal Strength Packet (S609), and transitions to the I&C phase.

[0097] Next, the RX200 transmits an ID packet to the TX100 (S610). Furthermore, the RX200 transmits an extended identification packet to the TX100 (S611). The extended identification packet contains the NFC identifier information stored in S602. Upon receiving the extended identification packet (S611), the TX100 stores the identifier information included in this packet (S612).

[0098] Then, the RX200 transmits a configuration packet to the TX100 (S613). This packet contains information in which the Neg bit is 1. Therefore, when the TX 100 responds with an ACK packet (S614), the process transitions to the negotiation phase.

[0099] When the RX200 transitions to the negotiation phase, it transmits a specific request packet to the TX100 (S615). Here, it is assumed that the RX200 specifies GP=15 watts in the specific request packet. When the WPC processing unit 301 of the TX100 receives this packet, it compares the NFC identifier information specified in S605 with the identifier information stored in S612 (S616). Here, it is assumed that the identifier information matches. The WPC processing unit 301 transmits an ACK packet to the RX200 (S617) and grants the GP specified in S615.

[0100] When the Negotiation phase ends, the TX100 and RX200 transition to the Calibration phase and the Power Transfer phase (S618). Then, the TX100 starts charging the RX200. The TX100 performs charging with an output that allows the charging unit 206 of the RX200 to receive 15 watts of power.

[0101] When the charging unit 206 has finished receiving power, the RX200 transmits an End Power Transfer Packet to the TX100 (S619). In response to this, the TX100 stops the charging process for the RX200 (S620). When the RX200 is removed from the TX100 (S621), the NFC processing unit 302 no longer responds to the polling process it performs (S622). This causes the NFC processing unit 302 to detect that the NFC device has left the communication range (S623). Then, the RX200 notifies the WPC processing unit 301 to erase the NFC identifier information notified in S605 (S624). In response to this, the WPC processing unit 301 erases the stored NFC identifier information.

[0102] 7 shows an example of a communication sequence between an RX200 with its NFC function disabled and an NFC tag when both are brought close to the TX 100. The RX200 may be a device without an NFC function.

[0103] 6, the NFC processing unit 302 of the TX100 periodically performs NFC polling processing (S701). When an NFC tag approaches within the communication range of the NFC standard, a response to the polling is made, and the NFC processing unit 302 detects that a device that is assumed to be an NFC tag has approached (S702). The NFC processing unit 302 reads NFC identifier information from the response to the polling and notifies the WPC processing unit 301 (S703).

[0104] The subsequent processing of S704 to S709 is the same as S605 to S610 in Fig. 6, and therefore a description thereof will be omitted. However, in the processing of Fig. 7, RX200 does not transmit an Extended Identification Packet. In other words, the processing equivalent to S611 and S612 in Fig. 6 is not performed. Furthermore, the processing of S710 to S712 is also the same as the processing of S613 to S615 in Fig. 6, and therefore a description thereof will be omitted.

[0105] When the WPC processing unit 301 of the TX100 receives the Specific Request Packet (S712), it compares the NFC identifier information specified in S703 with the additional identifier information acquired through WPC communication (S713). In the processing of Fig. 7, since the Extended Identification Packet has not been received, there is no additional identifier information acquired through WPC communication. Therefore, the NFC identifier information notified from the NFC processing unit 302 does not match the additional identifier information acquired through WPC communication. As a result, the WPC processing unit 301 transmits a NAK packet to the RX200 (S714) and rejects the GP specified in S712.

[0106] Upon receiving the NAK packet, the RX200 transmits a General Request Packet to the TX100 (S715) to request GP value information from the TX 100. In response, the TX100 transmits a Power Transmitter Capability Packet to the RX200, stating that GP=0.5 watts (S716).

[0107] When the Negotiation phase ends, the TX100 and RX200 transition to the Calibration phase and the Power Transfer phase (S717), and the TX100 starts charging the RX200. The TX100 performs charging with an output that allows the charging unit 206 of the RX200 to receive power at 0.5 watts.

[0108] When the charging unit 206 has finished receiving power, the RX200 transmits an End Power Transfer Packet to the TX100 (S718). In response to this, the TX100 stops the charging process for the RX200 (S719).

[0109] 6, even if the RX200 is removed from the TX100 (S720), the NFC processing unit 302 detects the NFC tag and does not notify the WPC processing unit 301 to erase the NFC identifier information. After that, when the NFC tag is removed from the TX100 (S721), the NFC processing unit 302 no longer responds to the polling process (S722). As a result, the NFC processing unit 302 detects that the NFC device has left the communication range (S723), and notifies the WPC processing unit 301 to erase the NFC identifier information notified in S703 (S724). In response to this, the WPC processing unit 301 erases the NFC identifier information it had stored.

[0110] (Example of power transmission control in a specific case) Here, the power transmission control in the following cases (1) to (3) will be explained.

[0111] (1) When an NFC device includes an NFC tag The NFC tag responds to the polling process. Furthermore, because the NFC tag does not support P2P mode, the NFC processing unit 302 determines that there is a specific response (Yes in S405). Next, the NFC processing unit 302 acquires NFC identifier information from the NFC tag (S408) and notifies the WPC processing unit 301 of the acquired NFC identifier information (S410). Furthermore, if there is an NFC device that has responded to the polling process in addition to the NFC tag, the NFC processing unit 302 also acquires NFC identifier information from that NFC device (S408) and notifies the WPC processing unit 301 of the acquired NFC identifier information (S410).

[0112] On the other hand, since the NFC tag is not the RX200, the processing shown in Fig. 8 is not performed. Therefore, the WPC processing unit 301 does not acquire the NFC identifier information of the NFC tag in the WPC processing shown in Fig. 5. Therefore, the result is No in S516 or S522 in Fig. 5, and the TX100 can limit power transmission. For example, the TX100 transmits only 0.5 watts of power as shown in S524. Alternatively, power transmission from the TX100 may be prevented.

[0113] (2) When only RX devices that support P2P mode are included as NFC devices In this case, the NFC device will either respond to the polling process using response data that includes information indicating that it supports P2P mode, or will not respond at all. Note that the NFC device that does not respond is the RX200 operating in reader / writer mode.

[0114] Therefore, the NFC processing unit 302 determines that there is no specific response (No in S405). As a result, the NFC processing unit 302 notifies the WPC processing unit 301 that there is no specific NFC device (S406). The NFC processing unit 302 also acquires NFC identifier information from the responding NFC device (S408) and notifies the WPC processing unit 301 of the acquired NFC identifier information (S410).

[0115] On the other hand, since the WPC processing unit 301 is notified that there is no specific NFC device, the determination in S515 or S522 in Fig. 5 is Yes. Then, the TX 100 allows transmission of the requested power or 15 watts.

[0116] (3) When the NFC device does not include an NFC tag and does not support P2P mode. In this case, the cases are further divided as follows:

[0117] (3-1) When the NFC device only includes RX operating in card emission mode and does not support P2P mode In this case, the NFC device responds to the polling process. However, the response does not include information indicating that the P2P mode is supported. Therefore, the NFC processing unit 302 determines that there is a specific response (Yes in S405). The NFC processing unit 302 then acquires NFC identifier information from the NFC device (S408) and notifies the WPC processing unit 301 of the acquired NFC identifier information (S410).

[0118] On the other hand, since this NFC device is operating in card emission mode, it notifies the TX 100 of the NFC identifier information (Yes in S805, S807, S808).

[0119] For this reason, the TX100 determines Yes in S515 in Fig. 5, and then determines Yes in S516. Alternatively, the TX100 determines Yes in S521 in Fig. 5, and then determines Yes in S522. Therefore, the TX100 allows transmission of the requested power or 15 watts.

[0120] (3-2) When the NFC device includes both RX operating in card emission mode that does not support P2P mode and RX operating in reader / writer mode In this case, the RX operating in reader / writer mode does not respond to the Polling process, but the RX operating in card emission mode does. Then, since the response does not include information indicating that P2P mode is supported, the NFC processing unit 302 determines that there is a specific response (Yes in S405). Also, since there is no response from the RX operating in reader / writer mode, the NFC processing unit 302 acquires NFC identifier information only from the RX operating in card emission mode (S408). Then, the NFC processing unit 302 notifies the WPC processing unit 301 of the acquired NFC identifier information (S410).

[0121] On the other hand, the RX operating in card emission mode notifies the TX 100 of the additional identifier information (Yes in S805, S807, S808). However, the RX operating in reader / writer mode does not notify the TX 100 of the additional identifier information (No in S805, S806).

[0122] Therefore, the TX100 acquires the same identifier information only from the RX operating in card emission mode, using the WPC processing unit 301 and the NFC processing unit 302. Therefore, the TX100 determines Yes in S515 in Fig. 5, and then determines Yes in S516. Alternatively, the TX100 determines Yes in S521 in Fig. 5, and then determines Yes in S522. Therefore, the TX100 allows transmission of the requested power or 15 watts.

[0123] (3-3) When the NFC device only includes RX operating in reader / writer mode that does not support P2P mode Since the RX operating in reader / writer mode does not respond to the polling process, the NFC processing unit 302 determines that there is no specific response (No in S405). As a result, the NFC processing unit 302 notifies the WPC processing unit 301 that there is no specific NFC device (S406). Furthermore, since there is no NFC device that has responded, the NFC processing unit 302 does not acquire NFC identifier information.

[0124] On the other hand, since the WPC processing unit 301 is notified that there is no specific NFC device, the determination in S515 or S522 in Fig. 5 is Yes. Then, the TX 100 allows transmission of the requested power or 15 watts.

[0125] (effect) As described above, by configuring the TX100 and RX200 as described above, it is possible to protect battery-powered NFC tags and perform high-power power transmission processing to RXs that have NFC modules operating in card emulation mode.

[0126] Furthermore, in the above-described embodiment, the NFC processing unit always stores the NFC identifier information of the NFC device that responded to the polling. Then, when the NFC identifier information disappears (YES in S412), that is, when the NFC device is removed, the NFC identifier information disappearance is notified to the WPC processing unit 301 (S413). Similarly, when an NFC processing error is resolved, the WPC processing unit 301 is notified to that effect. With this configuration, further benefits can be expected when an NFC tag is placed on the charging base of the TX100 while the RX200 is charging, or when the NFC tag is removed from the charging base. In other words, even when the RX200 receives power from the TX100 and is charging, it can dynamically change GP depending on whether or not an NFC tag is present, allowing charging to continue.

[0127] Specifically, when the TX100 is charging the RX200 while restricting GP as described in S524, the NFC processing unit 302 notifies the WPC processing unit 301 that the NFC identifier information has disappeared or that the error has been resolved. Upon receiving this notification, the WPC processing unit 301 recognizes that the cause of the GP restriction has been resolved. Therefore, the TX100 requests GP renegotiation from the RX200, transitions to the re-negotiation phase defined by the WPC standard, and performs GP renegotiation. Since the reason for restricting GP has been resolved at this point, the TX100 can respond in S523 with the maximum transmission power output value defined in the WPC standard, among the capabilities of the power transmitting unit 103, as the GP value.

[0128] Furthermore, since the WPC processing unit 301 successively updates whether or not an NFC tag exists, the WPC processing unit 301 will not mistakenly recognize that an NFC tag exists and restrict GP even when an NFC device no longer exists. Furthermore, even when the NFC processing unit 302 newly detects an NFC device, the WPC processing unit 301 will not mistakenly recognize that an NFC tag does not exist and transmit power at a high transmission power without restricting GP.

[0129] The above is an example of a typical embodiment, but this embodiment is not limited to the embodiment shown in the specification and drawings, and may be modified as appropriate within the scope that does not change the gist of the embodiment.

[0130] (Modifications regarding identifier information) In this embodiment, IDm data defined in the FeliCa standard is used as an example of NFC identifier information exchanged between the TX100 and the RX200. However, this is not a limitation in this embodiment, and any information that can uniquely identify multiple NFC devices present within the range of the TX100's NFC standard-based communication and WPC communication may be used. For example, the information may be a UID (Unique Identifier) ​​defined in the MIFARE (registered trademark) standard, or the MAC address or UUID (Universally Unique Identifier) ​​of the RX.

[0131] Furthermore, the identifier information may be a value calculated by hash calculation based on all or part of the NFC polling response data, or at least a part of the data including identifier information of the sender of the polling response data. In this case, the TX100 performs a hash calculation on the NFC polling response data received by the NFC processing unit 302, and notifies the WPC processing unit 301 of the calculated value as identifier information. Meanwhile, the RX200 performs the same hash calculation as the TX100 on data read as the NFC polling response data, and notifies the TX of the calculated value via WPC communication.

[0132] Alternatively, the RX 200 may include RX identifier information defined in the WPC standard in response data to the NFC polling process, and the TX 100 may acquire this information. For example, the Extended Device Identifier information included in the Extended Identification Packet may be used as the response data to the NFC polling.

[0133] Furthermore, the identifier information notified from the RX200 as an NFC device in the WPC process may be the identifier information notified in an ID packet from the RX200. In this case, in the WPC process of the RX200, the identifier information notified in the ID packet may be included in an Extended Identification Packet.

[0134] Note that, in the WPC processing, when the identifier information notified from the RX200 as an NFC device is the identifier information notified from the RX200 in an ID packet, the following configuration may be used. That is, the Extended Identification Packet may not be notified. In this case, the WPC processing unit 301 of the TX100 may compare the identifier information included in the ID packet notified from the RX200 with the NFC identifier information notified from the NFC processing unit 302. Note that the NFC identifier information notified from the NFC processing unit 302 is the identifier information included in the ID packet.

[0135] Furthermore, the RX200 may perform a hash calculation based on all or part of the Extended Device Identifier and transmit the calculated value as an NFC Polling response. In this case, the TX100 performs the same hash calculation as the RX200 on the identifier information of the RX200 included in the Extended Identification Packet received by the WPC processing unit 301 of the TX100. The TX100 may then compare the result of the hash calculation with the value received in the Polling response.

[0136] The hash calculation described above may be performed by any one of the NFC processing unit 302, the WPC processing unit 301 of the TX 100, and other processing units (not shown) of the control unit 101.

[0137] In addition, in this embodiment, the identifier information of the RX200 has been described as being Extended Device Identifier information included in an Extended Identification Packet. However, the identifier information of the RX200 may be other identifier information defined in the WPC standard. Specifically, the other identifier information may be Basic Device Identifier information included in an Identification Packet. Furthermore, the same effect can be obtained even if the other identifier information is WPID (Wireless Power ID) information included in a Wireless Power Identification Packet defined in the WPC standard.

[0138] Furthermore, if the RX200 operates the NFC function in multiple categories (Type A / B / F) defined by the NFC standard, the identifier information may be data that combines the NFC identifier information specified for each Type. This allows the TX100 to determine whether the identifier obtained in each category belongs to the RX200, even if the RX200 operates in NFC card emulation mode in multiple categories.

[0139] Furthermore, the TX100 may acquire the identifier information of the RX200 in WPC communication using a message packet other than the packet described in the present embodiment, or an extended message not described in the WPC standard. Furthermore, the identifier information of the RX200 may be acquired using a communication method such as wireless LAN, Bluetooth (registered trademark), Zigbee (registered trademark), IrDA (Infrared Data Association), or Wireless USB.

[0140] (Modifications regarding NFC processing) In the present embodiment, the TX100 detects a nearby NFC device by determining whether or not there is a response to a polling request. However, other methods may also be used. An additional NFC process may be used to determine whether or not a nearby NFC device is an NFC tag (or an NFC module operating in card emulation mode). For example, a different message process for an NFC function may be performed following the polling process to determine whether the NFC read data changes. If the read data changes, the detected NFC device may be determined to be not an NFC tag. Furthermore, if the response data acquired in the polling process includes an information element indicating that the device is not an NFC tag, the detected NFC device may be determined to be not an NFC tag. An NFC device determined not to be an NFC tag in this way is excluded from the targets for notifying the WPC processing unit 301 of its identifier information. This makes it possible to perform high-power power transmission processing even for an RX200, such as a smartphone, that does not have a process for transmitting identifier information via WPC communication.

[0141] 4, the processes of S402 and S403 may be performed after S405. Specifically, it may be determined (S405) whether or not a specific response has been received in response to a polling request (S401), and if a specific response has been received (Yes in S405), it may be determined (S402) whether or not an error has occurred in the specific response.

[0142] 4 may be configured to perform the following two separate determinations. That is, the NFC processing unit 302 may determine whether or not there is a response to the polling request (S401), and if there is a response, determine whether or not the response indicates that the P2P mode is not supported. If there is no response, or if there is a response but the response does not indicate that the P2P mode is not supported, the NFC processing unit 302 may perform the processing of S406. Note that if there is a response and the response indicates that the P2P mode is not supported, the process may proceed to S407.

[0143] In the above-described embodiment, the processing of the NFC processing unit 302 shown in FIG. 4 is continuously and repeatedly executed while the TX100 is activated. However, this embodiment is not limited to this, and this processing may be started and stopped at a specific timing. For example, the processing of FIG. 4 may be executed while the WPC processing unit 301 detects a nearby object using Analog Ping. This makes it possible to stop the processing of FIG. 4 while no object is present near the TX100, thereby reducing power consumption in the TX100. Furthermore, the processing of FIG. 4 may be executed from the time the WPC processing unit 301 receives a Signal Strength Packet until it receives an End Power Transfer Packet. This makes it possible to stop the processing of FIG. 4 while no RX with WPC functionality is present near the TX100, thereby further reducing power consumption in the TX100. Furthermore, the TX100 may start the processing of FIG. 4 when the WPC processing unit 301 receives a GP request equal to or greater than a preset threshold in a Specific Request Packet. As a result, the TX100 performs the process shown in Figure 4 only when performing an output power transmission process that may damage the NFC tag, thereby further reducing power consumption in the TX100.

[0144] Furthermore, although the program for operating the NFC processing unit 302 has been described as being executed by the control unit 101, this may be executed by another control unit (not shown). Specifically, the TX100 may be implemented inside another device (not shown) (printer, personal computer, mobile battery, etc.), and the other control unit that executes a control program for the functions of the other device may execute a program for operating the NFC processing unit 302.

[0145] (Variations regarding WPC treatment) Even when the TX100 does not restrict GP (e.g., S523), charging may continue without damaging the NFC tag. Specifically, while the TX100 is transmitting power without restricting GP as described in S523, the NFC processing unit 302 notifies the WPC processing unit 301 that the amount of NFC identifier information has increased or that an error has occurred. When the WPC processing unit 301 receives this notification, it recognizes that a reason to restrict GP has occurred. Therefore, the TX100 requests GP renegotiation with the RX200, transitions to the re-negotiation phase defined in the WPC standard, and performs GP renegotiation. At this point, a reason to restrict GP has occurred, so the TX100 can respond by setting a power value as GP that will not damage the NFC tag. Here, the configuration in which TX100 requests RX200 to renegotiate GP may be such that TX100 notifies RX200 that the NFC identifier information has disappeared or that the error has been resolved, and RX200 responds to that notification and requests GP renegotiation.

[0146] The TX100 may also request GP renegotiation from the RX200 as follows: That is, the TX100 may notify the RX200 that NFC identifier information has disappeared or increased, or that an error has occurred or been resolved, and the RX200 may request GP renegotiation in response to that notification.

[0147] In the above-described embodiment, the power transmission output value determined not to damage the NFC tag even when the TX100 performs the power transmission process is described as 0.5 watts, but this may be any other value as long as it does not damage the NFC tag. Specifically, it may be 5 watts, which is defined in the WPC standard as the GP value when power transmission is started in the Power Transfer phase (No in S508) without transitioning to the Negotiation phase, or may be any other value.

[0148] (Other variations) In this embodiment, NFC has been described as an example, but this is not limiting. For example, this embodiment can also be applied when the RX200 has a communication function that behaves like a tag that performs communication other than NFC, which is damaged by high-power transmission.

[0149] Furthermore, in the present embodiment, an example has been described in which an NFC device is detected by a response to the polling process by the second communication unit 202, but the present invention is not limited to this. Similarly, the RX200 does not have to be detected by communication via the first communication unit 104. For example, the user of the RX200 may notify the TX100 via the user interface of the TX100 that an NFC device, the RX200, has been placed on the charging stand. Even in this case, an NFC tag may be placed on the charging stand, so the above-described NFC process and WPC process may be executed.

[0150] <Other embodiments> The power transmission method of this wireless power transmission system is not particularly limited. It may be a magnetic resonance method, which transmits power by coupling through magnetic field resonance between a resonator (resonant element) of a power transmitting device and a resonator (resonant element) of a power receiving device. Alternatively, a power transmission method using electromagnetic induction, electric field resonance, microwaves, lasers, etc. may also be used.

[0151] The present invention can also be realized by supplying a program that realizes one or more functions of the above-described embodiments to a system or device via a network or a storage medium, and having one or more processors in the computer of the system or device read and execute the program. It can also be realized by a circuit (e.g., ASIC) that realizes one or more functions.

[0152] The power transmitting device and the power receiving device may be, for example, an image input device such as an imaging device (such as a camera or a video camera) or a scanner, or an image output device such as a printer, a copier, a projector, etc. Furthermore, they may be storage devices such as a hard disk drive or a memory device, or information processing devices such as a personal computer (PC) or a smartphone.

[0153] 4 and 5 are started when the power supply to the control unit of the power transmitting device is turned on. The processes shown in Fig. 4 and 5 are realized by the control unit executing a program stored in the memory of the power transmitting device. The process shown in Fig. 8 is realized by the control unit executing a program stored in the memory of the power receiving device.

[0154] At least a part of the processes shown in the flowcharts of Figures 4, 5, and 8 may be implemented by hardware. When implementing by hardware, for example, a specific compiler may be used to automatically generate a dedicated circuit on an FPGA from a program for implementing each step. Alternatively, a gate array circuit may be formed in the same manner as an FPGA and implemented as hardware. [Explanation of symbols]

[0155] 100 Power transmission device 101 Control section 103 Power Transmission Unit 104 First Communications Department 106 Second Communications Department 200 Powered Device

Claims

1. a power transmitting means for wirelessly transmitting power to a power receiving device; a polling means for performing polling using NFC communication; A detection means for performing an NFC tag detection process; a communication means for receiving configuration information from the power receiving device; Negotiation means for negotiating with the power receiving device, The power transmitting device is characterized in that the negotiation means determines negotiable power based on a result of the detection process.

2. The power transmitting device according to claim 1 , wherein the negotiation means limits the negotiable power when the NFC tag is detected.

3. 3. The power transmitting device according to claim 1, wherein the power transmitting unit transmits power based on information about power requested by the power receiving device when the NFC tag is not detected.

4. 4. The power transmitting device according to claim 1, wherein the negotiation means limits the negotiable power when a plurality of objects respond to the polling.

5. A method performed by a power transmission device, Polling is performed using NFC communication, Perform NFC tag detection processing, receiving configuration information from the powered device; Negotiating with the power receiving device; A method, wherein a negotiable power is determined based on the results of the detection process.

6. The power transmission device described in Claim 1, characterized in that the configuration information is capability information.

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