Power transmission device, method and program performed by the power transmission device

Abstract

To enable a power receiver which performs communication based on a NFC standard to appropriately receive power.SOLUTION: A control unit 101 controls, when a power receiver 200 detected through communication with a first communication unit 104 and a device that performs communication based on a NFC standard and that is detected through communication with a second communication unit 106 are the same, a feeding unit 103 to perform feeding with power higher than that when the devices are not the same.SELECTED DRAWING: Figure 5

Description

[Technical field]

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

[0002] 2. Description of the Related Art In recent years, technological developments regarding wireless power transmission systems such as contactless charging systems have been widely carried out. Patent Document 1 discloses a power transmitting device and a power receiving device that comply with a standard (hereinafter, referred to as the "WPC standard") established by the Wireless Power Consortium (WPC), a standardization organization for contactless charging.

[0003] In addition, there is the NFC (Near Field Communication) method as a type of wireless communication method. The standard (specification) established by the NFC Forum prescribes a card emulation mode in which a battery-powered NFC module behaves as if it were an NFC tag or an NFC card (hereinafter collectively referred to as "NFC tag"). In addition, a reader / writer mode for reading NFC tags and a peer-to-peer mode for directly exchanging messages between NFC devices are also prescribed. Some receiving devices such as smartphones that comply with the WPC standard 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] JP 2016-007116 A Summary of the Invention [Problem to be solved by the invention]

[0005] The NFC tag does not have a battery, and is driven by the energy of electromagnetic waves transmitted from the communication partner during communication. When high power is wirelessly transmitted to this NFC tag from the power transmitting device as described above, the antenna element of the NFC tag may be damaged. In order to avoid such a situation, it is considered that the power transmitting device limits the power transmission when it detects an object that communicates based on the NFC standard. However, such a configuration causes the following problem. That is, when the power transmitting device detects an object that communicates based on the NFC standard, it is considered that the power transmitting device limits the power transmission regardless of whether the object is an NFC tag or a power receiving device that communicates based on the NFC standard. Therefore, if the power transmission to the power receiving device that communicates 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 transmission device according to one embodiment of the present invention includes a power transmission 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 identification information from the power receiving device, and a negotiation means for negotiating with the power receiving device, and is characterized in that the negotiation means determines the negotiable power based on the result of the detection process. Effect of the Invention

[0008] According to the present invention, a power receiving device that performs communication based on the NFC standard can properly receive power. [Brief description 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. [Diagram 2] FIG. 2 is a block diagram showing a configuration example of a power receiving device according to the embodiment. [Diagram 3] FIG. 2 is a diagram illustrating functional blocks of a power transmitting device according to an embodiment. [Figure 4] 13 is a flowchart of an NFC processing unit of the power transmitting device. [Diagram 5] 13 is a flowchart of a WPC processing unit of the power transmitting device. [Figure 6] FIG. 4 is an operation sequence diagram of the wireless power transmission system according to the embodiment. [Figure 7] FIG. 4 is an operation sequence diagram of the wireless power transmission system according to the embodiment. [Figure 8] 11 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 PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Note that the following embodiment is merely an example for explaining the technical idea of ​​the present invention, and is not intended to limit the present invention to the configurations and methods described in the embodiment.

[0011] (System Configuration) FIG. 9 shows a configuration example 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 called TX, and the power receiving device may be called RX. The TX100 and the RX200 comply with the WPC standard. The RX200 receives power from the TX100 and enables charging of a 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 taking as an example a case where the RX200 is placed on the charging stand. However, when the TX100 transmits power to the RX200, the RX200 does not need to be placed on the charging stand as long as it is within the power transmitting 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 of 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 device or a memory device, or an information processing device such as a personal computer (PC). The RX200 and the TX100 may be, for example, an imaging device (a camera, a video camera, etc.).

[0013] The RX200 also has a Near Field Communication (hereinafter referred to as "NFC") function, which can be used to read NFC tags and make electronic money payments, for example. The TX100 also has an NFC function for reading NFC tags. Therefore, the TX100 can 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 result.

[0014] This system performs wireless power transmission using an electromagnetic induction method for contactless charging based on the WPC standard. That is, RX200 and TX100 perform wireless power transmission for contactless charging based on the WPC standard between the power receiving antenna of RX200 and the power transmitting antenna of TX100. Note that the wireless power transmission method (contactless power transmission method) applied to this system is not limited to the method defined by the WPC standard, and may be a method using other electromagnetic induction method, magnetic field resonance method, electric field resonance method, microwave method, laser method, etc. Also, in this embodiment, wireless power transmission is used for contactless charging, but wireless power transmission may 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 stipulated by a value called Guaranteed Power (hereafter referred to as "GP"). GP indicates the power value that is guaranteed to be output to the load of the RX200 (e.g., a charging circuit, etc.) even if the positional relationship between the RX200 and the TX100 fluctuates and the power transmission efficiency between the receiving antenna and the transmitting antenna decreases. For example, if the GP is 5 watts, the TX100 controls and transmits power so that it can output 5 watts to the load in the RX200, even if the positional relationship between the receiving antenna and the transmitting antenna fluctuates 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 specifies a number of phases, including a power transfer phase in which power transmission is performed and a phase before actual power transmission, and communication for 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. In the following, the identification and configuration phase is referred to as an I&C phase.

[0017] In the Selection phase, the TX100 transmits Analog Pings intermittently to detect that an object has been placed on the charging stand of the TX100 (for example, that the RX200 or a conductor piece has been placed on the charging stand). The TX100 detects at least one of the voltage value and current value of the power transmitting antenna when the Analog Ping is transmitted, 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 with 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 stand of the TX100. The RX200 notifies the TX100 of the magnitude of the received 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 is notified 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 this end, the RX200 transmits an ID packet and a configuration packet to the TX100. The ID packet contains the identifier information of the RX200, and the configuration packet contains the device configuration information (capability information) of the RX200. Having received the ID packet and configuration packet, the TX100 responds with an acknowledgement (ACK, positive response). And the I&C phase 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, based on the WPC standard, the RX200 notifies the TX100 of the received power value, and the TX100 makes adjustments to transmit power efficiently.

[0022] In the power transfer phase, control is performed for starting and continuing power transmission, as well as stopping power transmission due to an error or full charge.

[0023] To control power transmission and reception, the TX100 and the 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 the RX200 is almost the same as the power transmission range of the TX100 (the range indicated by the dashed line in FIG. 9).

[0024] The TX100 and the RX200 may perform communication for controlling power transmission and reception using an antenna and a frequency different from those for wireless power transmission (hereinafter referred to as "second communication"). For example, the electromagnetic waves used for the second communication are in a higher frequency band than the electromagnetic waves used for the first communication. In this case, the second communication can be used to perform communication at a higher speed than 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 be performed by other communication methods such as wireless LAN (e.g., Wi-Fi (registered trademark)) of the IEEE802.11 standard series, ZigBee, etc. 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 the TX100 can exchange information through the second communication.

[0026] (Device configuration) Next, the configuration of the power transmitting device 100 (TX100) and the power receiving device 200 (RX200) according to this embodiment will be described. Note that the configuration described below is merely an example, and a part (or in some cases, the whole) of the configuration described may be replaced with another configuration having a similar function or may be omitted, and further configuration may be added to the configuration described. Furthermore, one block shown in the following description may be divided into multiple blocks, and 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 includes a control unit 101, a power supply unit 102, a power transmission unit 103, a first communication unit 104, a power transmission 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 transmission unit 103, the first communication unit 104, the second communication unit 106, and the memory 107 are shown as separate entities, but any of these blocks may be implemented in 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 performs control related to power transmission control including communication for device authentication in the TX 100. The control unit 101 may also perform control for executing applications other than wireless power transmission. The control unit 101 includes one or more processors, such as a Central Processing Unit or a MicroProcessor Unit (MPU). The control unit 101 may be configured with hardware dedicated to a specific process, 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 a specific process. 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 the 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 in a half-bridge or full-bridge configuration using a FET (Field Effect Transistor). In this case, the power transmitting unit 103 includes a gate driver that controls ON / OFF of the FET.

[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 performs output control of AC frequency power so that power transmission from the power transmitting antenna 105 is started or stopped based on an instruction from the control unit 101. Furthermore, the power transmitting unit 103 is assumed to have the capacity to supply enough power to output 15 watts of power to the charging unit of the RX200 in compliance 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 the electromagnetic wave 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 wave output from the power transmitting antenna 105 and modulated in the RX200 to obtain 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 wave 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 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 the present embodiment, the NFC device also includes an NFC tag unless otherwise specified. The second communication unit 106 allows 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 transmission unit 103 to stop power transmission or to limit power transmission, such as by lowering the power of the power transmission. The second communication unit 106 has an antenna (not shown) different from the power transmission antenna 105.

[0034] Further, 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 (not shown) (a camera, a smartphone, a tablet PC, a laptop) that has the TX 100 built in.

[0035] The memory 107 stores the control program, as well as the status of the TX 100 and RX 200.

[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 realized as one 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 includes one or more processors such as a CPU or an MPU. Note that the control unit 201 may control the entire smartphone in cooperation with an OS (Operating System) being executed.

[0038] The control unit 201 may be configured with hardware dedicated to a specific process, such as an ASIC. The control unit 201 may 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 during execution of various processes in the memory 208. The control unit 201 may measure time using a timer (not shown).

[0039] The second communication unit 202 performs communication processing with other communication devices using the NFC function. The second communication unit 202 operates in a mode that complies with the standard established by the NFC Forum, for example. The above modes are, for example, a card emulation mode that substitutes for the role of a contactless IC card, a reader / writer mode for reading an NFC tag, and a P2P mode in which messages are directly exchanged between NFC devices. For example, the card emulation mode makes it possible to execute electronic money payments, etc. Note that the P2P mode is an abbreviation for Peer to Peer mode.

[0040] The second communication unit 202 has an antenna (not shown) different from the power receiving antenna 205 in order to perform communication based on the NFC standard. 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. Then, the power receiving unit 203 converts the AC power into DC or AC power of a predetermined frequency, and outputs the power to the charging unit 206 that performs processing for charging the battery 207. That is, 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 is assumed to have the capacity to supply power for the charging unit 206 to charge the battery 207 and 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 of the TX100. The first communication unit 204 demodulates the electromagnetic wave input from the power receiving antenna 205 to obtain information transmitted from the TX100. The first communication unit 204 performs the first communication with the TX100 by load modulating the input electromagnetic wave to superimpose a signal related to information to be transmitted to the TX100 on the electromagnetic wave. The first communication unit 204 may perform communication with the TX100 using the second communication instead of the first communication, or may perform communication 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 programs, as well as the states of the TX 100 and RX 200.

[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 the programs.

[0045] Next, the procedures of the processes 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 processor 302. This processing is continuously and repeatedly executed while the TX 100 is running.

[0047] When the TX100 is started, the second communication unit 106 starts the NFC Polling process (S401). Specifically, the second communication unit 106 transmits a Polling request and monitors the response to the Polling request to monitor the proximity of other NFC devices. When 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 means 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, in which response data cannot be received normally when multiple other NFC devices present within the communication range of the NFC standard respond at the same time.

[0048] When such an error occurs, NFC cannot be performed normally with other NFC devices within the communication range, and it is therefore impossible to confirm whether the detected NFC device includes a battery-free NFC tag. Therefore, the NFC processing unit 302 notifies the WPC processing unit 301 that an NFC tag may be in the vicinity, and the WPC processing unit 301, upon receiving this, 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 processing (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 processing.

[0050] Next, the NFC processing unit 302 judges 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 the 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). Also, 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] The specific NFC device is an NFC tag, a device that does not support P2P mode, or a device that supports P2P mode but operates in reader / writer mode. A device operating in reader / writer mode does not respond to a Polling request, regardless of whether it supports P2P mode or not. 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 result of S405 is No.

[0052] In addition, the absence of a specific response refers to the following cases. That is, when there is no device that performs communication according to the NFC standard, when an NFC device exists but does not respond to a Polling request, and when the device responds to a Polling request but supports the P2P mode. When a device supports the P2P mode, it means that the NFC device can operate in the P2P mode. For example, even if an NFC device operates in a card emulation mode, if the device supports the P2P mode, it is said that the device supports the P2P mode. Note that when a device supports the P2P mode, information indicating that the device supports the P2P mode is included in the response data to the Polling request. Therefore, the NFC processing unit 302 can determine whether or not the detected NFC device supports the 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, regardless of whether the response to the Polling request is a specific response or not, the NFC identifier information of the NFC device that has responded is acquired. 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 in the NFC standard, an area called IDm is defined as a format for communication data, and the content of data specified in the IDm area is defined in 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 acquisition of the NFC identifier information is successful (Yes in S409), the NFC processing unit 302 notifies the WPC processing unit 301 of the acquired NFC identifier information (S410). If acquisition of the NFC identifier information fails (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 identifier of the NFC device included in all the response data (S408 to 411), the NFC processing unit 302 compares the NFC identifier information acquired in the previous NFC processing with the NFC identifier information acquired in the current NFC processing. If the comparison shows that there is NFC identifier information that could not be acquired this time among the previously acquired NFC identifier information (Yes in S412), the NFC processing unit 302 notifies the WPC processing unit 301 that there is no more NFC identifier information and that NFC identifier information (S413). In addition, if the previous Polling processing failed to acquire an identifier but the current Polling processing does not fail to acquire an identifier, the NFC processing unit 302 notifies the WPC processing unit 301 that the error in the NFC processing has been resolved.

[0057] It should be noted that the NFC processing unit 302 notifies the WPC processing unit 301 of the error status of the NFC processing and the acquired NFC identifier information one by one, but this NFC processing is not limited to this. The notification to the WPC processing unit 301 may be sent collectively after all the processing is performed. The 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 the NFC identifier information (S411). The acquired NFC identifier information may also be made into a list, and the list may be notified to the WPC processing unit 301.

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

[0059] When the TX100 is started, the WPC processing unit 301 performs a selection phase process (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 the current value of the power transmitting antenna 105 when the Analog Ping is transmitted. When the voltage falls below a certain threshold or the current value exceeds a certain threshold, the TX100 determines that an object exists 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 a power sufficient to start the control unit 201 of the RX200 that is present in the vicinity of the power transmitting antenna 105. Next, when the TX100 receives a power receiving voltage notification notifying the magnitude of the power receiving voltage from the RX200, the TX100 transitions to the I&C phase. By receiving this power 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 refers to an information bit (Ext bit) included in the ID packet and determines whether or not 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 is to be transmitted, waits for an Extended Identification Packet transmitted from the RX200, and receives the packet (S505). The packet includes 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 included in the ID packet, and is stored in the memory 107 as NFC identifier information acquired in the NFC process.

[0063] Next, the TX 100 receives a configuration packet transmitted from the RX 200 (S507). The TX 100 refers to an information bit (Neg bit) included in this packet and determines whether or not to transition to the negotiation phase (S508).

[0064] In the Negotiation phase, the TX100 negotiates with the RX200 to determine the above-mentioned 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 power transmission 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 process in the negotiation phase (S512 to S524), the TX100 waits for a specific request packet or a general request packet transmitted from the RX200.

[0066] When the TX100 receives a Specific Request Packet (Yes in S512), it judges whether the GP value specified in this packet is acceptable (S513 to S518). The Specific Request Packet includes a candidate value for the power (GP) requested by the RX200. The TX100 first judges whether the specified GP value is equal to or less than a preset threshold (S513). The threshold here is a threshold for the power transmission output that is determined not to cause damage to the NFC tag even if the power transmission process 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 (Yes in S513), the TX100 judges whether an error has occurred in the NFC processing (S514). Specifically, the WPC processing unit 301 judges whether the NFC processing unit 302 has notified 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, 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 occurs in the NFC process (No in S514), the TX 100 judges whether or not there is an NFC device that has made a specific response to the Polling request (S515). Specifically, the WPC processing unit 301 makes this judgment based on whether or not the NFC processing unit 302 has notified the WPC processing unit 301 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 transmits 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 judges 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 judges whether these identifier information match (S516). If the identifier information matches, the WPC processing unit 301 judges 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 they are the same device (Yes in S516), the TX100 accepts the specified GP value and transmits an ACK Packet to the RX200 (S517). In this case, the TX100 judges that the RX200 has a power source for executing WPC communication processing, and that some power is being supplied to the module that executes the NFC function of the RX200. Therefore, the TX100 judges that even if the 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 process is not the same as the RX200 detected in the WPC process (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). Since the NFC tag is not the RX200, the WPC process as shown in FIG. 5 is not executed, and the NFC identifier information is not transmitted to the TX100. Therefore, it is determined that the NFC device detected in the NFC process is not the same as the RX200 detected in the WPC process. After that, the TX100 continues to wait for a Specific Request Packet or a General Request Packet.

[0073] In addition, when there are multiple pieces of NFC identifier information notified by the NFC processing unit 302, if the processing of S506 has not stored corresponding additional identifier information for all of the NFC identifier information, a NAK packet is transmitted to the RX200 (S518). In other words, when there is any identifier among the multiple identifiers notified by the NFC processing unit 302 for which corresponding additional identifier information has not been stored in S506, a NAK packet is transmitted to the power receiving device 200. On the other hand, when the processing of S506 has stored corresponding additional identifier information for 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, from the General Request Packet, a packet requesting notification of the capabilities (power transmitter capacity) of the TX 100 (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] First, the TX100 judges whether an error has occurred in the NFC process (S520). The method of judgment is the same as the process of S514. If an error has occurred in the NFC process (Yes in S520), the TX100 responds with a power transmission output value that can be determined not to damage the NFC tag even if the power transmission process is performed as a GP value (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, and a notification may be made that power transmission will not be performed.

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

[0077] If there is a specific NFC device that responded to the Polling request (Yes in S521), the TX100 judges 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 judgment is the same as the process in S516.

[0078] If it is determined that they are the same device (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 they are not the same device (No in S516), the TX100 responds as GP with a power transmission output value that is determined not to damage the NFC tag even if the power transmission process is performed (S524). In other words, if it is determined that they are the same device, the TX100 sets the GP larger than when it is determined that they are not the same device, 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 parameters required for a 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 responded to in S523 or S524.

[0080] After that, 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 operation 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 detects that the TX100 is nearby by receiving the Digital Ping transmitted from the TX100 (Yes in S801) (S802). In response to this, the control unit 201 acquires setting and operation information of the NFC in the second communication unit 202 (S803). The setting and operation information here includes a state indicating whether the NFC function in the RX200 is enabled or disabled, an NFC operation mode, and NFC identifier information that can uniquely identify the NFC device. The NFC operation mode here indicates the NFC operation mode in the second communication unit 202, and indicates any one of the three modes of the card emulation mode, the reader / rider mode, and the P2P mode. Next, the control unit 201 notifies the TX100 of the receiving voltage of the Digital Ping by using a Signal Strength Packet via the first communication unit 204 (S804).

[0083] Next, the control unit 201 selects the next packet to be transmitted according to the setting and operation information of the NFC communication acquired in S803. Specifically, if the NFC function is enabled and the NFC operation mode is the card emulation mode (Yes in S805), the control unit 201 transmits an ID packet to the TX100 (S807). Here, the control unit 201 sets the Ext bit in the ID packet to be transmitted to 1, and notifies the TX100 that an Extended Identification Packet will be transmitted next.

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

[0085] Furthermore, if the NFC function is disabled, or if the NFC function is enabled but the operation mode is not the card emulation mode (No in S805), the control unit 201 does not transmit an Extended Identification Packet. In other words, an Identification Packet with the Ext bit set to 0 is transmitted to the TX100 (S806). In this way, by determining whether or not to transmit a packet depending on the operation 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 a negotiation phase in which negotiations are performed to determine the GP. When the RX200 receives an ACK packet from the TX100 (Yes in S810), it transitions to the negotiation phase. 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 control unit 201 transits to the negotiation phase, it transmits a Specific Request Packet specifying 15 watts as a GP candidate to the TX100 (S811). When the RX200 receives an ACK Packet from the TX100 (Yes in S812), it determines that the GP of 15 watts has been granted by the TX100, and the GP in the power receiving 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 GP of 15 watts has been rejected by the TX100. In this case, the RX200 transmits a General Request Packet to the TX100 (S815) to request a GP candidate at the TX100. When the RX200 receives a Power Transmitter Capability Packet from the TX100 (S816), the value of the GP candidate for the TX100 contained in this packet is determined as the GP for the current 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 waiting for a Digital Ping.

[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 required for a foreign object detection function that detects the presence of an object other than the RX200 near the power receiving antenna 205. In the calibration phase, the RX200 also performs processing to supply power from the power receiving unit 203 to the charging unit 206, which serves as a load.

[0091] After that, the TX100 and the 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 charging processing.

[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 the 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 communication range of the NFC, a response is made to the polling request, 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 processor 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, 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. Here, it is assumed that "NFC function = enabled", "operation mode = card emulation mode", and "NFC identifier information = FeliCa IDm information" are acquired. The RX200 then notifies the TX100 of the receiving 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 contained in this packet (S612).

[0098] Then, the RX200 transmits a configuration packet to the TX100 (S613). This packet contains information that 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 the RX200 transition to the calibration phase and the power transfer phase (S618). Then, the TX100 starts a charging process for the RX200. The TX100 performs a charging process with an output that allows the charging unit 206 of the RX200 to receive power at 15 watts.

[0101] When the charging unit 206 finishes 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 response to the Polling process performed by the NFC processing unit 302 is no longer made (S622). As a result, the NFC processing unit 302 detects that the NFC device has left the communication range (S623). Then, the WPC processing unit 302 is notified 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 the NFC function.

[0103] As in the explanation of Fig. 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 communication related to the NFC standard, a response to the polling is made, and the NFC processing unit 302 detects that a device 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 processes of S704 to S709 are the same as those of S605 to S610 in Fig. 6, and therefore their explanation will be omitted. However, in the process of Fig. 7, RX200 does not transmit an Extended Identification Packet. In other words, the processes corresponding to S611 and S612 in Fig. 6 are not performed. Furthermore, the processes of S710 to S712 are the same as those of S613 to S615 in Fig. 6, and therefore their explanation 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 in the WPC communication (S713). In the process of FIG. 7, since the Extended Identification Packet has not been received, there is no additional identifier information acquired in the WPC communication. Therefore, the NFC identifier information notified from the NFC processing unit 302 does not match the additional identifier information acquired in the 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 of the TX100. 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 the RX200 transition to the calibration phase and the power transfer phase (S717), and the TX100 starts a charging process for the RX200. The TX100 performs a charging process 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 finishes 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] Unlike the processing in Fig. 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 stops responding to the Polling processing (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 stored NFC identifier information.

[0110] (Examples of power transmission control in specific cases) Here, the power transmission control in the following cases (1) to (3) will be described.

[0111] (1) When the NFC device includes an NFC tag The NFC tag responds to the Polling process. Furthermore, since the NFC tag does not support the 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 responded to the Polling process other than the NFC tag, the NFC identifier information is also acquired from the 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 process 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 process shown in Fig. 5. Therefore, the result is No in S516 or S522 in Fig. 5, and the TX100 can limit the power transmission. For example, the TX100 transmits power at only 0.5 watts as shown in S524. Alternatively, power transmission from the TX100 may be prevented.

[0113] (2) If the NFC device only includes RX that supports P2P mode In this case, the NFC device responds to the Polling process using response data including information indicating that it supports P2P mode, or does 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 the 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 does not support P2P mode and only includes RX operating in card emission 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). Then, the NFC processing unit 302 acquires NFC identifier information from this 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 the card emission mode, it notifies the TX 100 of the NFC identifier information (Yes in S805, S807, S808).

[0119] Therefore, the TX 100 determines Yes in S515 in Fig. 5, and further determines Yes in the determination in S516. Alternatively, the TX 100 determines Yes in S521 in Fig. 5, and further determines Yes in the determination in S522. Therefore, the TX 100 allows the transmission of the requested power or 15 watts.

[0120] (3-2) The NFC device includes both an RX operating in card emission mode that does not support P2P mode and an RX operating in reader / writer mode. In this case, the RX operating in the reader / writer mode does not respond to the Polling process, but the RX operating in the card emission mode responds. Since the response does not include information indicating that the P2P mode is supported, the NFC processing unit 302 determines that there is a specific response (Yes in S405). Furthermore, since there is no response from the RX operating in the reader / writer mode, the NFC processing unit 302 acquires NFC identifier information only from the RX operating in the 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 the card emission mode notifies the TX 100 of the additional identifier information (Yes in S805, S807, S808). However, the RX operating in the 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 by the WPC processing unit 301 and the NFC processing unit 302 only from the RX operating in the card emission mode. Therefore, the TX100 judges Yes in S515 in Fig. 5, and further judges Yes in the judgment in S516. Alternatively, the TX100 judges Yes in S521 in Fig. 5, and further judges Yes in the judgment in S522. Therefore, the TX100 allows the transmission of the requested power or 15 watts.

[0123] (3-3) When the NFC device only includes RX that operates in reader / writer mode and does not support P2P mode Since the RX operating in the 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). In addition, since there is no responding NFC device, 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 the 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-less NFC tags and perform high-output power transmission processing to an RX having an NFC module operating in card emulation mode.

[0126] 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 is lost (YES in S412), that is, when the NFC device is removed, the NFC identifier information is notified to the WPC processing unit 301 (S413). Similarly, when an error in the NFC processing is resolved, the WPC processing unit 301 is notified to that effect. With such a configuration, further effects can be expected when the 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 the 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. When the WPC processing unit 301 receives the notification, it recognizes that the cause of the GP restriction has been resolved. Then, the TX100 requests the RX200 to renegotiate the GP, transitions to a re-negotiation phase defined in the WPC standard, and renegotiates the GP. At this point, the reason for restricting the GP has been resolved, so in S523, the TX100 can respond as a GP value the maximum transmission output value defined in the WPC standard among the capabilities of the power transmitting unit 103.

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

[0129] The above is an example of a typical embodiment, but the present 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 present embodiment.

[0130] (Modifications regarding identifier information) In this embodiment, IDm data defined in the Felica standard is exemplified as the NFC identifier information exchanged between the TX100 and the RX200. However, this is not a limitation in this embodiment, and any information capable of uniquely identifying 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, a value calculated by hash calculation based on the whole or part of the NFC Polling response data, or at least a part including the identifier information of the sender of the Polling response data, may be used as the identifier information. 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 the identifier information. On the other hand, the RX200 performs the same hash calculation as the TX100 on the data read as the NFC Polling response data, and notifies the TX of the calculated value by WPC communication.

[0132] Also, the RX 200 may include RX identifier information defined by the WPC standard in response data to the NFC Polling process, and the TX 100 may acquire this. For example, Extended Device Identifier information included in an Extended Identification Packet may be used as 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] In addition, in the WPC process, when the identifier information notified from RX200 as an NFC device is the identifier information notified from RX200 in an ID packet, the following configuration may be used. That is, an Extended Identification Packet may not be notified. In this case, the WPC processing unit 301 of TX100 may compare the identifier information included in the ID packet notified from RX200 with the NFC identifier information notified from the NFC processing unit 302. In addition, 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 WPC processing unit 301 of the TX100 performs the same hash calculation as the RX200 on the identifier information of the RX200 included in the Extended Identification Packet received. The TX100 may then be configured to compare the result of the hash calculation with the value received in the Polling response.

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

[0137] In addition, in this embodiment, the identifier information of RX200 has been described as being Extended Device Identifier information included in an Extended Identification Packet. However, the identifier information of 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. Also, 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 by each Type. This makes it possible for the TX100 to determine whether the identifier acquired in each category is that of the RX200, even if the RX200 operates the NFC card emulation mode in multiple categories.

[0139] In addition, the TX100 may obtain the identifier information of the RX200 in the WPC communication by using a message packet defined by the WPC standard or an extended message not described in the standard, instead of the packet described in the above embodiment. Furthermore, the identifier information of the RX200 may be obtained by using a communication means such as wireless LAN, Bluetooth (registered trademark), Zigbee (registered trademark), IrDA (Infrared Data Association), Wireless USB, etc.

[0140] (Modifications regarding NFC processing) In the present embodiment, the method of determining whether or not there is a response to the Polling request has been described as a method for the TX100 to detect a nearby NFC device, but other methods may be used. In addition, an additional NFC process may be used to determine whether or not the nearby NFC device is an NFC tag (or an NFC module operating in card emulation mode). For example, a message process with a different NFC function may be performed following the Polling process to determine whether or not the NFC read data changes. If the read data changes, the detected NFC device may be determined to be not an NFC tag. 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 to be not an NFC tag in this way is excluded from the targets for notifying the WPC processing unit 301 of identifier information. This makes it possible to perform high-power power transmission processing even for an RX200 such as a smartphone that is not equipped with a process for sending identifier information by WPC communication.

[0141] 4, the processes of S402 to S403 may be performed after S405. Specifically, it may be determined (S405) whether or not there is a specific response to a Polling request (S401), and if there is a specific response (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 process 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 process of the NFC processing unit 302 shown in FIG. 4 is executed repeatedly and continuously while the TX100 is activated. However, the present embodiment is not limited to this, and the process may be started / stopped at a specific timing. For example, the process of FIG. 4 may be executed while the WPC processing unit 301 detects a nearby object by Analog Ping. This makes it possible to stop the process of FIG. 4 while there is no object near the TX100, and it becomes possible to reduce the power consumption of the TX100. In addition, the process of FIG. 4 may be executed from when 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 process of FIG. 4 while there is no RX with a WPC function near the TX100, and it becomes possible to further reduce the power consumption of the TX100. Furthermore, the timing at which the TX100 starts the process of FIG. 4 may be when the WPC processing unit 301 is requested by a Specific Request Packet for a GP equal to or greater than a threshold value set in advance. As a result, the TX100 performs the process of FIG. 4 only when performing a power transmission process of an output that may damage the NFC tag, thereby making it possible to further reduce power consumption in the TX100.

[0144] Also, the program for operating the NFC processing unit 302 has been described as being executed by the control unit 101, but this may be executed by another control unit (not shown). Specifically, the TX 100 may be implemented inside another device (not shown, such as a printer, a personal computer, or a mobile battery), 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] (Modifications regarding WPC treatment) Even when the TX100 is in a state where the GP is not restricted (for example, S523), charging may be continued without damaging the NFC tag. Specifically, while the TX100 is transmitting power without restricting the GP as described in S523, the NFC processing unit 302 notifies the WPC processing unit 301 that the NFC identifier information has increased or that an error has occurred. When the WPC processing unit 301 receives the notification, it recognizes that a reason to restrict the GP has occurred. Then, the TX100 requests the RX200 to renegotiate the GP, transitions to the re-negotiation phase defined in the WPC standard, and renegotiates the GP. At this point, a reason to restrict the GP has occurred, so the TX100 can respond by setting a power value that does not damage the NFC tag as the GP. 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 configuration in which the TX100 requests the RX200 to renegotiate GP may be 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 respond to the notification and request GP renegotiation.

[0147] In the above-described embodiment, the power transmission output value that is determined not to damage the NFC tag even if the TX100 performs the power transmission process is described as 0.5 watts, but this may be another value as long as it does not damage the NFC tag. Specifically, it may be 5 watts 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 it may be another value.

[0148] (Other variations) In this embodiment, NFC has been described as an example, but this is not limited to this. For example, this embodiment can be applied even 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] In the present embodiment, an example has been described in which the 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 and a device that is the RX200 have been placed on the charging stand. Even in this case, an NFC tag may be placed on the charging stand, so the above-mentioned NFC process or WPC process may be executed.

[0150] <Other embodiments> The power transmission method of the wireless power transmission system is not particularly limited. It may be a magnetic resonance method that transmits power by coupling due to magnetic resonance between a resonator (resonant element) of a power transmitting device and a resonator (resonant element) of a power receiving device. It may also be a power transmission method using an electromagnetic induction method, an electric field resonance method, a microwave method, a laser method, or the like.

[0151] The present invention can also be realized by a process in which a program for realizing one or more functions of the above-mentioned embodiments is supplied to a system or device via a network or a storage medium, and one or more processors in the computer of the system or device read and execute the program. Also, the present invention can be realized by a circuit (e.g., ASIC) for realizing 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 (camera, video camera, etc.) or a scanner, or an image output device such as a printer, a copy machine, a projector, etc. Furthermore, they may be storage devices such as a hard disk device or a memory device, or may be information processing devices such as a personal computer (PC) or a smartphone.

[0153] The flow charts shown in Fig. 4 and Fig. 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 Fig. 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 realized by hardware. In the case of hardware realization, for example, a specific compiler may be used to automatically generate a dedicated circuit on an FPGA from a program for realizing each step. Also, a gate array circuit may be formed in the same manner as an FPGA, and the process may be realized as hardware. [Explanation of symbols]

[0155] 100 Power transmission equipment 101 Control section 103 Power Transmission Section 104 First Communications Department 106 2nd 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 a detection process of an NFC tag; A communication means for receiving identifier information from the power receiving device; Negotiation means for negotiating with the power receiving device, The power transmitting device, wherein 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. 5. The power transmitting device according to claim 1, wherein the communication unit transmits information indicating the negotiable power when the power receiving device requests capability information of the power transmitting device during negotiation.

6. The power transmitting device according to claim 5 , wherein the information indicating the negotiable power is transmitted using a packet of Power Transmitter capability defined in a Wireless Power Consortium standard.

7. 7. The power transmitting device according to claim 5, wherein the communication unit receives a packet indicating the request, the packet being a General Request packet defined in a Wireless Power Consortium standard.

8. if the NFC tag is not detected, the negotiable power value is a first value; The power transmitting device according to claim 1 , wherein, when the NFC tag is detected, the negotiable power value is a second value that is smaller than the first value.

9. 9. The power transmitting device according to claim 1, further comprising an acquisition unit configured to acquire information used for distinguishing the NFC tag from the power receiving device.

10. The power transmitting device according to claim 9 , wherein the detection unit performs the detection process based on the information acquired by the acquisition unit.

11. A method performed by a power transmitting device, comprising: Polling is performed using NFC communication. Perform NFC tag detection processing, receiving identifier information from the power receiving device; Negotiating with the power receiving device; A method, comprising: determining a negotiable power based on a result of the detection process.

12. A program for causing a computer to execute the control method according to claim 11.

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