Power receiving device, power supply device, power supply system, and method

Abstract

To provide a power receiving device, a power supply device, a power supply system, and a method that are able to determine a signal for wireless power supply and a signal for wireless communication.SOLUTION: In order to solve the problem described above, a power receiving device according to an embodiment includes: a power receiving unit that receives a wireless signal including at least one of a wireless power supply signal and a wireless communication signal and receives power; and a processing unit that determines whether the wireless signal includes the wireless power supply signal or not based on an amount of feature of the wireless signal.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] Embodiments of the present invention relate to a power receiving device, a power feeding device, a power feeding system, and a method.

Background Art

[0002] Wireless power feeding technology using electromagnetic waves has been developed. When wireless power feeding coexists with other wireless communication systems, it is necessary to determine a signal for wireless power feeding and a signal for wireless communication.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The problem to be solved by the embodiments of the present invention is to provide a power receiving device, a power feeding device, a power feeding system, and a method capable of determining a signal for wireless power feeding and a signal for wireless communication.

Means for Solving the Problems

[0005] To solve the above problems, a power receiving device according to an embodiment includes a power receiving unit that receives and receives a wireless signal including at least one of a wireless power feeding signal and a wireless communication signal, and a processing unit that determines whether the wireless signal includes the wireless power feeding signal from a feature amount of the wireless signal.

Brief Description of the Drawings

[0006] [Figure 1] Schematic diagram of a power feeding system 100 in a first embodiment. [Figure 2] Configuration example of a power feeding device 1 in a first embodiment. [Figure 3] Configuration example of a power receiving device 2 in a first embodiment. [Figure 4] A sequence diagram showing a first example of operation of the power supply device 1 and the power receiving device 2 in the first embodiment. [Figure 5] A sequence diagram showing a second example of operation of the power supply device 1 and power receiving device 2 in the first embodiment. [Figure 6] A sequence diagram showing a third example of operation of the power supply device 1 and power receiving device 2 in the first embodiment. [Figure 7] A flowchart illustrating an example of the operation of the power supply device 1 in the first embodiment. [Figure 8] A figure showing a first example of the amplitude of the wireless power transmission signal of the power supply device 1 in the first embodiment. [Figure 9] This figure shows a second example of the amplitude of the wireless power transmission signal of the power supply device 1 in the first embodiment. [Figure 10] This figure shows a third example of the amplitude of the wireless power transmission signal of the power supply device 1 in the first embodiment. [Figure 11] A diagram illustrating an example of the amplitude of wireless communication signals. [Figure 12] This diagram shows an example of a power supply channel when supplying power in the 5.7GHz band. [Figure 13] A flowchart illustrating an example of the operation of the power receiving device 2 in the first embodiment. [Figure 14] An example configuration of the power receiving device 2' applicable to the first embodiment. [Figure 15] This figure shows a first example of whether or not a signal indicating the power received by the power receiving device 2 needs to be transmitted in a modified example. [Figure 16] This figure shows a second example of whether or not it is necessary to transmit a signal indicating the power received by the power receiving device 2 in a modified example. [Figure 17] This figure shows a third example of whether or not it is necessary to transmit a signal indicating the power received by the power receiving device 2 in a modified example. [Figure 18] An example configuration of the power supply device 1' applicable to the first embodiment. [Figure 19] An example configuration of the power receiving device 2" applicable to the first embodiment. [Figure 20] A sequence diagram illustrating an example of the operation of power supply device 1' and power receiving device 2'' in a modified example. [Figure 21]Configuration example of the power receiving device 2'” applicable to the first embodiment. [Figure 22] Diagram showing an example of the frequency of the wireless power supply signal of the power supply device 1 in the modification. [Figure 23] Configuration example of the power receiving device 2”” applicable to the first embodiment.

Mode for Carrying Out the Invention

[0007] Hereinafter, embodiments for carrying out the invention will be described with reference to the drawings. The disclosure is merely an example, and the invention is not limited by the content described in the following embodiments. Modifications that can be easily conceived by those skilled in the art are naturally included in the scope of the disclosure. For the sake of clarity, in the drawings, the size, shape, etc. of each part may be changed with respect to the actual embodiment and represented schematically. In a plurality of drawings, the same reference numerals may be assigned to corresponding elements, and detailed descriptions may be omitted.

[0008] (First Embodiment) FIG. 1 is a schematic diagram of the power supply system 100 in the first embodiment. The power supply system 100 includes a power supply device 1, power receiving devices 2A and 2B. Hereinafter, when comprehensively referring to the power receiving devices 2A and 2B or explaining common parts, they are also simply referred to as the power receiving device 2. In the power supply system 100 of FIG. 1, there is one power supply device 1 and two power receiving devices 2, but there is no limit to the number of the power supply device 1 and the power receiving device 2. In the power supply system 100, wireless power supply (wireless power transmission) is performed from the power supply device 1 to the power receiving device 2. Hereinafter, the signal for wireless power supply is also referred to as a wireless power supply signal. The power receiving device 2 receives the wireless power supply signal from the power supply device 1 and generates DC power. (Hereinafter, it is also referred to as receiving power.)

[0009] When performing wireless power supply from the power supply device 1 to the power receiving device 2, wireless power supply may be performed from the power supply device 1 to the power receiving device 2 for testing. The power receiving device 2 measures the amount of power received by the test wireless power supply and transmits a signal indicating the amount of power received to the power supply device 1. The power supply device 1 determines items related to wireless power supply based on the information on the amount of power received by the power receiving device 2.

[0010] Here, in the environment where the power supply system 100 is arranged, there may be a wireless communication terminal 3. The wireless communication terminal 3 is at least part of the devices constituting an existing wireless system. Since this wireless communication terminal 3 also conducts communication, the wireless signals received by the power receiving device 2 may include not only the wireless power supply signal but also both the wireless power supply signal and the wireless communication signal over time, that is, they may be mixed. In the case of wireless communication between the power supply device 1 and the power receiving device 2, if a frequency band different from that of the wireless power supply signal is used, the power receiving device 2 can identify the wireless power supply signal and the wireless communication signal. For example, when the wireless power supply signal transmitted by the power supply device 1 is in the 5.7 GHz band and the wireless communication between the power supply device 1 and the power receiving device 2 uses the 2.4 GHz band, the power receiving device 2 can identify the wireless power supply signal and the wireless communication signal.

[0011] However, when the frequency band in which the wireless communication terminal 3 communicates is near the frequency band of the wireless power supply signal transmitted by the power supply device 1, the wireless signals received by the power receiving device 2 may include a mixture of the wireless power supply signal from the power supply device 1 and the wireless communication signal from the wireless communication terminal 3. For example, when the wireless communication terminal 3 communicates via a wireless LAN and the communication frequency band is the 5 GHz band, and the frequency band of the wireless power supply signal of the power supply device 1 is the 5.7 GHz band, it may be mixed in the wireless signals received by the power receiving device 2.

[0012] Furthermore, when performing wireless power supply, the power supply device 1 conducts carrier sense to check whether the wireless communication terminal 3 is communicating in the vicinity of the power supply device 1. As a result of the carrier sense, if the wireless communication terminal 3 is in communication, the power supply device 1 waits for the transmission of the wireless power supply signal and transmits after the communication is completed.

[0013] Therefore, the power receiving device 2 needs to determine whether the wireless signal received by the power receiving device 2 is a wireless power supply signal or a signal (hereinafter also referred to as a wireless communication signal) for the wireless communication terminal 3 to communicate. This is because the measurement result of the amount of power received by wireless power supply is required for the setting regarding the transmission of the wireless power supply signal of the power supply device.

[0014] In this embodiment, the power supply device 1 transmits a wireless power supply signal that includes a different set of features from the wireless communication signal, and the power receiving device 2 determines from the features of the received wireless signal whether the wireless power supply signal is included in the wireless signal. This allows the power receiving device 2 to distinguish between the wireless power supply signal and other wireless communication signals. Note that the wireless communication signal also includes signals used for communication between the power supply device 1 and the power receiving device 2.

[0015] Figure 2 shows an example of the configuration of the power supply device 1 in the first embodiment. The power supply device 1 comprises a processing unit 10, a power supply unit 11, an antenna 12, a communication unit 13, an antenna 14, and a storage unit 15. The processing unit 10 comprises a control unit 101 and a calculation unit 102.

[0016] The power supply unit 11 transmits a wireless power supply signal containing characteristic quantities different from the wireless communication signal via the antenna 12, and wirelessly supplies power to the power receiving device 2. These characteristic quantities include power (amplitude) and frequency, but details will be described later. The wireless power supply signal is radiated as electromagnetic waves from the antenna 12. The radiation of electromagnetic waves indicating the wireless power supply signal is also referred to as the transmission of the wireless power supply signal. The power supply unit 11 receives the wireless power supply signal and instructions from the control unit 101 (described later) and performs wireless power supply. These instructions include, for example, at least one item such as the time period, duration, power (amplitude), phase, frequency band, and transmission direction for transmitting the wireless power supply signal. These items are related to wireless power supply. Note that multiple patterns (hereinafter also referred to as transmission patterns) may be set using one or more of these items.

[0017] For example, the Industrial, Scientific, and Medical (ISM) band of 5,727-5,875 MHz, or the narrower 5,738-5,766 MHz, is used as the frequency band to which the wireless power transmission signal is transmitted. These frequency bands are called the 5.7 GHz band. The bandwidth of the wireless power transmission signal is set to a predetermined width, for example, less than 100 kHz. The transmission power of the wireless power transmission signal is, for example, a maximum of 10 W, and the eirp (equivalent isotropically radiated power) is 1 kW. The electromagnetic wave of the wireless power transmission signal is a continuous wave (CW) and may be unmodulated (NON).

[0018] When transmitting a wireless power supply signal, the power supply unit 11 performs carrier sensing to check whether the wireless communication terminal 3 is communicating (i.e., whether a wireless communication signal is present) in the vicinity of the power supply device 1. Carrier sensing is performed to prevent the power supply from interfering with the communication of the wireless communication terminal 3, that is, to ensure the coexistence of the power supply device 1 and the wireless communication terminal 3. The power supply unit 11 receives electromagnetic waves via the antenna 12 and transmits or waits for a wireless communication signal depending on the result.

[0019] The communication unit 13 performs wireless communication by modulating the wireless communication signal and transmitting it via the antenna 14, and by receiving and demodulating the wireless communication signal via the antenna 14. The wireless communication partner is, for example, the power receiving device 2. The communication unit 13 sends and receives signals containing information related to wireless power supply to the power receiving device 2 via wireless communication. Information related to wireless power supply includes, for example, the prior communication exchange necessary for wireless power supply, request information from the power supply device 1 to the power receiving device 2 to measure the amount of power received by the wireless power supply signal (hereinafter also referred to as the received power amount), and information from the power receiving device 2 to the power supply device 1 regarding the received power amount and the requested power amount. The received information on the received power amount and the requested power amount is sent to the control unit 101.

[0020] The frequency band used by the communication unit 13 for wireless communication is different from the frequency band used by the power supply unit 11 for wireless power supply. For example, if the communication unit 13 uses Bluetooth for wireless communication... TMWhen using Bluetooth Low Energy (BLE), the frequency band used is the ISM band (2.4GHz band) of 2,400–2,500MHz.

[0021] The storage unit 15 holds information according to the instructions of the control unit 101. The information held is related to wireless power supply, and includes, for example, identification information of the devices (power supply device 1 and power receiving device 2) that constitute the power supply system 100, information indicating the arrangements necessary for wireless power supply, information on items related to wireless power supply, information on the amount of power received from the power receiving device 2, and information on the amount of power requested. Any storage medium can be set as the storage unit 15. For example, memory or storage.

[0022] The control unit 101 controls each part of the power supply device 1. For example, it generates a wireless power supply signal to instruct the power supply unit 11 to perform wireless power supply, generates a signal (which may also be called a measurement request signal or first signal) to the power receiving device 2 to measure the amount of power received and instructs the communication unit 13 to transmit it, sends information related to wireless power supply to the calculation unit 102 (described later) and instructs it to calculate items related to wireless power supply, and has the storage unit 15 hold the information sent from various locations and read it as needed.

[0023] The calculation unit 102 calculates and determines items related to wireless power supply based on information sent from the control unit 101. For example, it calculates items related to wireless power supply based on at least one of the following: information on the amount of power received, the power of the wireless power supply signal when the power receiving device 2 measured the amount of power received, and information on the amount of power requested. The calculation results are sent to the control unit 101 and used for generating wireless power supply signals and giving instructions to the power supply unit 11. The calculation results may also be stored in the storage unit 15. When a power transmission pattern is set for wireless power supply, the calculation unit 102 may determine the power transmission pattern based on one or more items related to wireless power supply, or it may select a combination from a plurality of existing power transmission patterns.

[0024] The power supply device 1 has been described above. The processing unit 10 of the power supply device 1 is one or more electronic circuits, including a control unit and an arithmetic unit. The electronic circuits are implemented as analog or digital circuits, etc. For example, a general-purpose processor, a central processing unit (CPU), a microprocessor, a digital signal processor (DSP), an ASIC, an FPGA, and combinations thereof are applicable. The processing unit 10 may also be executed on these electronic circuits by software or a program. Antennas 12 and 14 may be shared, and if there are multiple power supply devices 1, at least some of the components of the power supply device 1 described may be shared.

[0025] Figure 3 shows an example of the configuration of the power receiving device 2 in the first embodiment. The power receiving device 2 comprises a processing unit 20, a power receiving unit 21, an antenna 22, a measurement unit 23, a communication unit 24, an antenna 25, and a storage unit 26. The processing unit 20 comprises a control unit 201 and a calculation unit 202, and the power receiving unit 21 comprises a rectifier 211 and a load 212.

[0026] The power receiving unit 21 receives a wireless signal via the antenna 22 and generates DC power. In particular, the power receiving unit 21 receives power by receiving a wireless power supply signal from the power supply device 1 and generating DC power. More specifically, the power receiving device 2 receives electromagnetic waves radiated from the power supply device 1 as a wireless power supply signal and generates DC power. The reception of electromagnetic waves indicating a wireless signal is also referred to as receiving a wireless signal, the reception of electromagnetic waves indicating a wireless power supply signal is also referred to as receiving a wireless power supply signal, and the reception of electromagnetic waves indicating a wireless communication signal is also referred to as receiving or receiving a wireless communication signal.

[0027] The rectifier 211 converts the AC power of the received wireless signal into DC power. This DC power is measured by the measuring unit 23 via the load 212. The measuring unit 23 measures the amount of energy (received energy) of the DC power sent from the load 212. The measured received energy is sent to the control unit 201. The measuring unit 23 may also be referred to as the first measuring unit.

[0028] The frequency band in which the power receiving unit 21 receives wireless signals may be the same as the frequency band of the wireless power transmission signal, or it may be a wider frequency band that includes the frequency band of the wireless power transmission signal. For example, if the power supply device 1 selects a frequency band (channel) from 5,727-5,875MHz (5,738-5,766MHz may also be used) to transmit wireless power transmission signals, the power receiving unit 21 may use the 5GHz band, which includes 5,470-5,725MHz (hereinafter referred to as the 5.6GHz band) used by wireless LANs (Local Area Networks), as the frequency band for receiving wireless signals. This makes the configuration of the power receiving unit 21 simpler and less expensive.

[0029] The communication unit 24 performs wireless communication by modulating the wireless communication signal and transmitting it via the antenna 25, and by receiving and demodulating the wireless communication signal via the antenna 25. The wireless communication partner is, for example, the power supply device 1. The communication unit 24 sends and receives signals containing information related to wireless power supply with the power supply device 1 via wireless communication. This information related to wireless power supply includes, for example, the prior communication exchange necessary for wireless power supply, request information from the power supply device 1 to the power receiving device 2 to measure the amount of power received, and information from the power receiving device 2 to the power supply device 1 regarding the amount of power received and the requested amount of power. The received request information to measure the amount of power received is sent to the control unit 201.

[0030] The frequency band in which the communication unit 24 conducts wireless communication is the same as the frequency band in which the communication unit 13 of the power supply device 1 conducts wireless communication, and is different from the frequency band in which the power supply unit 11 conducts wireless power supply.

[0031] The storage unit 26 holds information according to the instructions of the control unit 201. The information held is related to wireless power transfer, and includes, for example, identification information of the devices (power supply device 1 and power receiving device 2) that constitute the power supply system 100, information indicating the arrangements necessary for wireless power transfer, request information for measuring the amount of power received from power supply device 1, and power consumption information of each part of power receiving device 2. Any storage medium as described in the storage unit 15 can be implemented as the storage unit 26.

[0032] The control unit 201 controls each part of the power receiving device 1. For example, it generates a signal (which may be called a second signal) containing information indicating the measured amount of power received and a signal containing information indicating the requested amount of power, and instructs the communication unit 24 to transmit them to the power supply device 1. It also sends information related to wireless power supply to the calculation unit 202 (described later) and instructs it to calculate the requested amount of power. Finally, it causes the storage unit 26 to store information sent from various locations and read it as needed.

[0033] The calculation unit 202 calculates the required power based on the information sent from the control unit 201. For example, it calculates the required power based on at least one of the measured power received and the power consumption information of each part of the power receiving device 2. The calculation result is sent to the control unit 201 and used to generate a signal containing information indicating the required power and to give instructions to the communication unit 24. The calculation result may also be stored in the storage unit 26.

[0034] The power receiving device 2 has been described above. The processing unit 20 of the power receiving device 2 can implement any electronic circuit described in the processing unit 10 of the power supply device 1. Furthermore, the processing unit 20 may be executed on these electronic circuits by software or programs. Also, antennas 22 and 25 may be shared, and if there are multiple power receiving devices 2, at least some of the components of the power receiving device 2 described may be shared.

[0035] Using Figures 4 to 6, we will explain an example of the operation of the power supply device 1 and the power receiving device 2 in this embodiment. Figure 4 is a sequence diagram showing a first example of the operation of the power supply device 1 and the power receiving device 2 in the first embodiment. The first example of operation shows the process from when the power supply device 1 sends a signal requesting measurement of the amount of power received to the power receiving device 2, until the power supply device 2 receives a signal indicating the amount of power received. First, the power supply device 1 sends a signal requesting measurement of the amount of power received to the power receiving device 2. Then, the power supply device 1 sends a wireless power supply signal to the power receiving device 2. The power receiving device 2 receives the wireless power supply signal and measures the amount of power received. The power receiving device 2 sends a signal indicating the measured amount of power received to the power supply device 1, which receives it.

[0036] Furthermore, the power supply device 1 sets a timeout timer (time Tt) to wait for a signal indicating the amount of power received after transmitting a signal requesting measurement of the amount of power received. This time Tt is usually set to allow sufficient time for the power receiving device 2 to receive the wireless power supply signal, measure the amount of power received, and transmit a signal indicating the measured amount of power received. In other words, if the power supply device 1 does not receive a signal indicating the amount of power received even after time Tt has elapsed, it is presumed that either the signal requesting measurement of the amount of power received, the wireless power supply signal, or the signal indicating the amount of power received transmitted by the power supply device 1 did not reach the destination, or there was an error in the operation of the power receiving device 2.

[0037] Furthermore, the power receiving device 2 sets a timeout timer (time Tr) to wait for the wireless power supply signal after receiving a power receiving power measurement request signal. This time Tr is usually set to allow sufficient time for the power receiving device 2 to receive the wireless power supply signal. In other words, if the wireless power supply signal is not received even after the time Tr has elapsed, it can be inferred that either the wireless power supply signal did not reach the power receiving device 2 or there was an error in the operation of the power supply device 1. In the first example of operation, the signal indicating the power receiving amount has reached the power supply device 1, indicating normal operation.

[0038] After the first example of operation, the power supply device 1 determines the items related to wireless power supply based on the received amount of power and performs wireless power supply.

[0039] Figure 5 is a sequence diagram showing a second example of operation of the power supply device 1 and power receiving device 2 in the first embodiment. The second example of operation shows the process from when the power supply device 1 sends a signal requesting measurement of the amount of received power to the power receiving device 2, until the power receiving device 2 sends a notification indicating that it was unable to receive a wireless power supply signal. First, the power supply device 1 sends a signal requesting measurement of the amount of received power to the power receiving device 2 and sets a timeout timer (time Tt) to wait for a signal indicating the amount of received power. The power receiving device 2 receives the measurement request signal and sets a timeout timer (time Tr) to wait for a wireless power supply signal.

[0040] Subsequently, the power supply device 1 transmits a wireless power supply signal to the power receiving device 2. However, the power receiving device 2 fails to receive the wireless power supply signal and is unable to measure the amount of power received. After the timeout timer Tr has elapsed, the power receiving device 2 sends a notification to the power supply device 1 indicating that it was unable to receive the wireless power supply signal, and the power supply device 1 receives this notification.

[0041] After the second operation example, the power supply device 1 sends a signal requesting measurement of the amount of power received to the power receiving device 2 again.

[0042] Figure 6 is a sequence diagram showing a third operational example of the power supply device 1 and power receiving device 2 in the first embodiment. The third operational example shows the process from when the power supply device 1 sends a power receiving device 2 a signal requesting measurement of the received power amount until a timeout occurs due to the power receiving device 2 failing to receive a signal indicating the received power amount. First, the power supply device 1 sends a power receiving device 2 a signal requesting measurement of the received power amount and sets a timeout timer (time Tt) to wait for a signal indicating the received power amount. The power receiving device 2 receives the measurement request signal and sets a timeout timer (time Tr) to wait for a wireless power supply signal.

[0043] Subsequently, the power supply device 1 transmits a wireless power supply signal to the power receiving device 2. The power receiving device 2 receives the wireless power supply signal and measures the amount of power received. The power receiving device 2 transmits a signal indicating the measured amount of power received to the power supply device 1, but the power supply device 1 fails to receive this signal and the timeout timer Tt elapses.

[0044] After the second operation example, the power supply device 1 sends a signal requesting measurement of the amount of power received to the power receiving device 2 again.

[0045] Figure 7 is a flowchart of an example of the operation of the power supply device 1 in the first embodiment. An example of the operation of the power supply device 1 will be explained using Figure 7. First, the control unit 101 generates a signal indicating a request to measure the amount of power to be received by the power receiving device 2, and the communication unit 13 transmits this request signal via the antenna 14. After transmission, the control unit 101 sets a timeout timer (time Tt) to wait for the signal indicating the amount of power received (step S11).

[0046] The control unit 101 generates a wireless power supply signal that includes feature quantities different from the wireless communication signal, and the power supply unit 11 transmits this wireless power supply signal via the antenna 12 (step S12). The feature quantities will be described below.

[0047] In this embodiment, the characteristic features of the wireless power transmission signal are one of the following: the amplitude is set to a predetermined range regardless of time, the time variation of the amplitude is set to a predetermined positive range, or a predetermined negative range. Figures 8 to 10 show the first to third examples of the amplitude of the wireless power transmission signal from time t1 to t2. Figure 8 shows an example where the amplitude of the wireless power transmission signal is kept constant regardless of time. The amplitude is (V11-V12), but in a real environment, there are fluctuations in amplitude due to noise, reflection, diffraction, and amplitude and phase fluctuations called fading, so it may be set to a predetermined range that takes amplitude fluctuations into account (the first range). Figures 9 and 10 show examples where the time variation of the amplitude of the wireless power transmission signal is set to a predetermined positive or negative range. The time variation of the amplitude in Figure 9 is (V21-V23) / (t2-t1) or (V24-V22) / (t2-t1), but it may be set to a predetermined range that takes amplitude fluctuations into account (the second positive range). The time variation of the amplitude in Figure 10 is (V31-V33) / (t2-t1) or (V34-V32) / (t2-t1), but it may be within a predetermined range (within the negative third range) that takes amplitude fluctuations into account. Alternatively, the predetermined range may be determined by pre-learning the DC power of the wireless power transmission signal and the DC power of the wireless communication signal.

[0048] When the wireless power transmission signal includes the aforementioned feature quantities, a different trend is obtained when it is converted to DC power compared to the wireless communication signal. If the amplitude of the wireless power transmission signal is set to a predetermined range regardless of time, the converted DC power value will also fall within the predetermined range. If the time variation of the amplitude of the wireless power transmission signal is set to a predetermined positive or negative range, the time variation of the converted DC power will also fall within the predetermined positive or negative range.

[0049] On the other hand, Figure 11 shows an example of the amplitude of a wireless communication signal. When a wireless communication signal is modulated to include information (data), the amplitude fluctuates over time, and the time variation of the amplitude also fluctuates compared to the case described above, with a mix of positive and negative values. Therefore, the wireless communication signal converted to DC power fluctuates over time (exceeding the range that takes into account noise and distance attenuation), and this time variation of DC power also exceeds a predetermined range of positive or negative values.

[0050] As described above, in this embodiment, if the amplitude of the power supply signal is set to a predetermined range regardless of time, or if the time change of the amplitude is set to a predetermined positive or negative range, then when the power receiving device 2 converts it to DC power, it is possible to determine whether or not the wireless signal received by the power receiving device 2 includes the wireless power supply signal.

[0051] When the power supply unit 11 transmits a wireless power supply signal, it uses a predetermined frequency band. This frequency band is also called a channel (power supply channel). Figure 12 shows an example of a power supply channel when power is supplied in the 5.7GHz band, with nine channels set within the 5,740-5,764MHz range. The power supply unit 11 transmits the wireless power supply signal using a predetermined channel from these channels. Note that the channels in Figure 12 are just an example, and even when power is supplied in the same 5.7GHz band, various channels can be set.

[0052] The following is a description of the operation of the power supply device 1. After step S12, the control unit 101 waits for time Tt to receive a signal indicating the amount of power received by the power receiving device 2 via the communication unit 13 (step S13). If the communication unit 13 receives a signal indicating the amount of power received and the control unit 101 receives the information indicating the amount of power received within time Tt (step S13: Yes), the process proceeds to step S14. The control unit 101 also resets the timeout timer Tt. On the other hand, if the control unit 101 does not receive the information indicating the amount of power received within time Tt (step S13: No), the control unit 101 estimates that either the signal requesting measurement of the amount of power received, the wireless power supply signal, or the signal indicating the amount of power received transmitted by the power supply device 1 did not reach the destination, or there was an error in the operation of the power receiving device 2. In this case, the process returns to step S11.

[0053] In step S14, the control unit 101 checks whether the amount of power received by the power receiving device 2 meets predetermined conditions based on the information indicating the amount of power received. For example, if the control unit 101 has set a lower limit or range for the amount of power received by the power receiving device 2 based on the power of the transmitted wireless power supply signal, then if the amount of power received deviates from this lower limit or range, the control unit 101 estimates that the predetermined conditions are not met and that the power receiving device 2 is not receiving power via the wireless power supply signal. If the amount of power received by the power receiving device 2 does not meet the predetermined conditions (step S14: No), the process returns to step S11. If the amount of power received by the power receiving device 2 meets the predetermined conditions (step S14: Yes), the control unit 101 sends information indicating the amount of power received by the power receiving device 2 to the calculation unit 102 and instructs it to calculate the items related to wireless power supply.

[0054] The calculation unit 102 determines the wireless power transmission items by calculating at least one wireless power transmission item, such as the time period, duration, power (amplitude), phase, frequency band, and transmission direction, based on information indicating the amount of power received by the power receiving device 2 (step S15). The calculated items are sent to the control unit 101.

[0055] The control unit 101 generates a wireless power supply signal that satisfies the calculated items and instructs the power supply unit 11 to perform wireless power supply that satisfies the calculated items. Based on the wireless power supply signal and the instruction, the power supply unit 11 transmits the wireless power supply signal via the antenna 12 (step S16).

[0056] The control unit 101 checks whether or not a termination command has been received to terminate the operation of the power supply device 1 (step S17). This termination command is a command to terminate the operation of the power supply device 1 in this flow. This termination command is transmitted to the control unit 1 by the user's input to the power supply device 1, or by the power supply device 1 acquiring a signal containing the termination command. This termination command may be a command to immediately terminate the operation of the power supply device 1.

[0057] If the control unit 101 has not received this termination command (step S17: No), the process returns to step S11. On the other hand, if the control unit 101 has received this termination command (step S17: Yes), the process ends and the power supply device 1 ceases operation. Step S17 may be performed independently of this process, either after a predetermined time has elapsed or only when the control unit 101 receives the termination command. After step S17: No, the process returns to S16 and repeats the generation and transmission of wireless power supply signals that satisfy the determined items.

[0058] The operation example of the power supply device 1 of this embodiment has been described above. Figure 13 is a flowchart of the operation example of the power receiving device 2 in the first embodiment. The operation example of the power receiving device 2 will be explained using Figure 13.

[0059] The communication unit 24 receives a signal from the power supply device 1 via the antenna 25 indicating a request to measure the amount of power that the power receiving device 2 will receive. The communication unit 24 sends this request information to the control unit 201, and the control unit 201 sets a timeout timer (time Tr) to wait for the wireless power supply signal (step S21).

[0060] If the timeout timer exceeds time Tr (step S22If no power is received, the control unit 201 estimates that the wireless power supply signal did not reach the power receiving device 2 or that there was an error in the operation of the power supply device 1. In this case, the control unit 201 generates a notification signal for the power supply device 1 and has the communication unit 24 transmit it via the antenna 25 (step S22). The information included in the notification signal may be a request to retransmit a signal to the power supply signal 1 indicating a request to measure the amount of power that the power receiving device 2 will receive, or information indicating that the amount of power received is zero. After step S22, the process returns to step S21 to try again.

[0061] On the other hand, if the timeout timer is within time Tr (step S22 Yes), the power receiving unit 21 receives the wireless signal, and the measurement unit 23 measures the characteristic quantities of the wireless signal (step S24). In this embodiment, the power receiving unit 21 converts the wireless signal into DC power, and the measurement unit 23 measures at least one of the value of the DC power and the time variation of the DC power as characteristic quantities. (Step S24) , control unit 201 Send the measurement results.

[0062] The control unit 201 determines from the measurement results sent from the measurement unit 23 whether or not the received wireless signal includes a wireless power supply signal (step S25). More specifically, the control unit 201 checks whether or not the measurement results satisfy the characteristics of the wireless power supply signal. Based on the difference in characteristics between the wireless power supply signal and the wireless communication signal, as explained in the flowchart of the power supply device 1, the control unit 201 can determine whether or not the received wireless signal includes a wireless power supply signal. If the control unit 201 determines that the received wireless signal does not include a wireless power supply signal (step S25: No), the process returns to step S22.

[0063] If the control unit 201 determines that the received wireless signal includes a wireless power supply signal (step S25: Yes ) The control unit 201 generates a signal indicating the amount of power received by the wireless signal that it has determined to contain a wireless power supply signal, and the communication unit 24 transmits it to the power supply device 1 via the antenna 25 (step S26). The control unit 201 also resets the timeout timer Tr.

[0064] Subsequently, the power supply device 1 determines the items related to wireless power supply based on the amount of power received and transmits a wireless power supply signal that satisfies these items. The power receiving unit 21 waits to receive the wireless power supply signal, and when the wireless power supply signal is transmitted, it receives it and receives power (step S27).

[0065] The control unit 201 checks whether a termination command has been received to terminate the operation of the power receiving device 2 (step S28). This termination command is a command to terminate the operation of the power receiving device 2 in this flow. This termination command is transmitted to the control unit 201 by means of input from the user to the power receiving device 2, or by the power receiving device 2 acquiring a signal containing the termination command. This termination command may be a command to immediately terminate the operation of the power receiving device 2.

[0066] If the control unit 201 has not received this termination command (step S28: No), the process returns to step S21. On the other hand, if the control unit 201 has received this termination command (step S28: Yes), the process ends and the power receiving device 2 ceases operation. Step S28 may be performed independently of this process, either after a predetermined time has elapsed or only when the control unit 201 receives the termination command. After step S28: No, the process returns to S27 and repeats the process of receiving wireless power supply signals that satisfy the determined items.

[0067] The operation example of the power receiving device 2 of this embodiment has been described above. The power supply device 1 and power receiving device 2 described in this embodiment are just examples, and various modifications can be implemented and executed. Modifications of the power supply device 1 and power receiving device 2 will be described below. This embodiment and the modifications described below can be used in combination with each other. In the modifications, if the components and steps described in this embodiment are the same, the same reference numerals are used and the description is omitted.

[0068] (Variation 1) The power receiving unit 21 of the power receiving device 2 includes a rectifier 211 and a load 212, but may also include a matching circuit and a DC-DC converter. Figure 14 shows an example configuration of the power receiving device 2' applicable to the first embodiment. The power receiving device 2' includes a power receiving unit 21' instead of the power receiving unit 21 of the power receiving device 2. The power receiving unit 21' further includes a rectifier 211 and a load 212, a matching unit 221 and a DC-DC converter 222.

[0069] The impedance matching unit 221 is installed between the antenna 22 and the rectifier 211. The impedance matching unit 221 performs impedance matching between the antenna 22 and the rectifier 211. This reduces losses between the antenna 22 and the rectifier 211.

[0070] The DC-DC converter 222 is installed between the rectifier 211 and the load 212. The DC-DC converter 222 converts the DC voltage rectified by the rectifier 211. This allows for the stabilization of the DC voltage and the use of the operating voltage of the power receiving device 2.

[0071] Note that while Figure 14 shows both a matching circuit 221 and a DC-DC converter 222, either one or the other may be used.

[0072] (Modification 2) In determining the wireless power supply item in step S15 of the power supply device 1, the calculation unit 102 may further calculate based on at least one of the information indicating the power amount requested by the power receiving device 2 and the information indicating the transmission power of the wireless power supply signal at the time of measurement of the power receiving device 2. The communication unit 13 receives a signal from the power receiving device 2 that includes information indicating the power amount requested by the power receiving device 2 and sends it to the control unit 101, but this may be received at any time before step S15 or may have been received from the beginning. The calculation unit 102 receives this information indicating the power amount requested from the control unit 101. The calculation unit 102 receives information from the control unit 101 indicating the transmission power of the wireless power supply signal at the time of measurement of the power receiving device 2 before steps S11 to S15.

[0073] In the power receiving device 2, the calculation unit 202 may calculate the power requirement for the power receiving device 2 based on at least one of the measured power received and the power consumption of the components of the power receiving device 2. Information indicating the calculated power requirement is sent to the control unit 201. The control unit 201 may generate a signal indicating this power requirement and have the communication unit 24 transmit it to the power supply device 1 via the antenna 25. If the calculation unit 202 uses the power received measured by the calculation unit 202, this is done between steps S26 and S27. On the other hand, if the calculation unit 202 uses the power consumption of the components of the power receiving device 2, the calculation can be performed regardless of the step if the power consumption information can be obtained in advance. If the power receiving device 2 wants the items related to the wireless power supply signal of the power supply device 1 to be determined considering the power requirement of the power receiving device 2, the power receiving device 2 must transmit a signal indicating the power requirement by step S27.

[0074] As shown in this modified example, the power supply device 1 can determine power supply parameters to achieve more efficient power supply by based on at least one of the power demand of the power receiving device 2 or the transmitted power of the wireless power supply signal during measurement of the power receiving device 2.

[0075] (Variation 3) In this embodiment, the power supply device 1 transmits a measurement request signal to the power receiving device 2, and the power receiving device 2 receives this measurement request signal and measures the amount of power to be received by a wireless signal. In this modified example, the power supply device 1 transmits a signal to the power receiving device 2 indicating the duration for which a wireless power supply signal is transmitted, and the power receiving device 2 receives this signal, compares the duration with the duration for which a wireless power supply signal is determined to be included, and decides whether or not to transmit a signal indicating the amount of power received.

[0076] In this modified example, the operation of the power supply device 1 differs from step S11. Instead of generating a signal requesting measurement of the amount of power received by the power receiving device 2, the control unit 101 generates a signal (also referred to as the third signal) indicating the duration for which the wireless power supply signal is transmitted. The communication unit 13 transmits this signal to the power receiving device 2 via the antenna 14 (step S11'). Steps S12 onward are the same as described in the first embodiment.

[0077] In this modified example, the operation of the power receiving device 2 differs in steps S21 and S25. Except for these steps, it is the same as described in the first embodiment. Step S21', which replaces step S21, will be described. Instead of receiving a measurement request signal for the amount of power received by the power receiving device 2 via the antenna 25, the communication unit 24 receives a signal indicating the time length for which the power supply device 1 transmits the wireless power supply signal. The control unit 201 sets a timeout timer (time Tr) (step S21').

[0078] Step S25', which replaces step S25, is described below. The control unit 201 determines from the measurement results sent from the measurement unit 23 whether it has received a radio signal that is determined to contain a radio power supply signal during the period from the first time length to the second time length, based on the time length during which the power supply device 1 transmits a radio power supply signal (hereinafter also referred to as the power supply time length) (step S25'). If it is determined that the received radio signal does not contain a radio power supply signal, or if the received radio signal contains a radio power supply signal but the time to receive the radio signal containing the radio power supply signal does not meet the conditions (step S25': No), the process returns to step S22. It may also return to step S21'. If the received radio signal contains a radio power supply signal and the time to receive the radio signal containing the radio power supply signal meets the conditions (step S25': Yes), the process proceeds to step S26.

[0079] Figures 15 to 17 show three examples of whether or not the power receiving device 2 should transmit a signal indicating the received power in this modified example. The first example in Figure 15 shows a case where the time for receiving a wireless signal, including a wireless power supply signal, is within the time range based on the power supply time length. In this case, the control unit 201 decides to generate and transmit a signal indicating the amount of received power. The second example in Figure 16 shows a case where the time for receiving a wireless signal, including a wireless power supply signal, is shorter than the time range based on the power supply time length. In this case, the control unit 201 decides not to generate and transmit a signal indicating the amount of received power. The third example in Figure 17 shows a case where the time for receiving a wireless signal, including a wireless power supply signal, is longer than the time range based on the power supply time length. In this case, the control unit 201 decides not to generate and transmit a signal indicating the amount of received power.

[0080] As shown in this modified example, by having the power supply device 1 notify the power receiving device 2 of the power supply duration, the power receiving device 2 can determine whether it has received the wireless power supply signal transmitted by the power supply device 1 based on the time it takes to receive a wireless signal that is determined to contain a wireless power supply signal. Furthermore, even if there is a wireless communication terminal 3' that sends and receives signals that do not contain communication data in the vicinity of the power supply system 100, the power receiving device 2 can still determine whether the wireless power supply signal from the power supply device 1 is included.

[0081] Furthermore, the following methods can be used to share the time duration for transmitting wireless power transmission signals between the power supply device 1 and the power receiving device 2. As method 1, the time duration for transmitting wireless power transmission signals may be predetermined as a specification or standard for wireless power transmission between the power supply device 1 and the power receiving device 2. As method 2, the time duration for transmitting wireless power transmission signals to the power supply device 1 and the power receiving device 2 may be set by input via a user interface or the like.

[0082] (Modification 4) In this embodiment, the power receiving device 2 determined whether the wireless power transmission signal transmitted by the power supply device 1 was included in the wireless power transmission signal based on the characteristic quantities of the wireless signal received by the power receiving device 2. In this modified example, the power supply device 1 also determines whether the power receiving device 2 has received the wireless power transmission signal based on the time the power supply device 1 transmitted the wireless power transmission signal and the time the power receiving device 2 received the wireless signal which it determined to contain the wireless power transmission signal.

[0083] Figure 18 shows an example configuration of a power supply device 1' applicable to the first embodiment, and Figure 19 shows an example configuration of a power receiving device 2” applicable to the first embodiment. In power supply device 1', the processing unit 10 of power supply device 1 is changed to processing unit 10', and in power receiving device 1”, the processing unit 20 of power receiving device 2 is changed to processing unit 20'. Processing unit 10' further includes a clock unit 103 in addition to processing unit 10. Processing unit 20' further includes a clock unit 203 in addition to processing unit 20.

[0084] The clock unit 103 records the time (which may be called the first time) when the power supply unit 11 transmits the wireless power supply signal. As the time of transmission of the wireless power supply signal, the clock unit 103 may record the time at the same time as or immediately after the power supply unit 11 transmits the wireless power supply signal, or it may record the time when the control unit 101 instructs the power supply unit 11 to transmit the wireless power supply signal.

[0085] The clock unit 203 records the time of receipt of a wireless signal that is determined to contain a wireless power supply signal (which may be called the second time). The time of receipt of a wireless signal that is determined to contain a wireless power supply signal may be recorded at the same time as or immediately after the determination that the wireless power supply signal is contained, or at the end of the time period in which the wireless power supply signal is contained, or at any time within that time period.

[0086] Figure 20 shows a sequence diagram illustrating an example of the operation of the power supply device 1' and the power receiving device 2" in a modified example. Figure 20 shows the process from when the power supply device 1' sends a signal requesting measurement of the amount of power received to the power receiving device 2" until the power supply device 1' receives a signal from the power receiving device 2" indicating the amount of power received.

[0087] First, power supply device 1' sends a signal requesting measurement of the received power amount to power receiving device 2'', which power receiving device 2'' receives. Next, power supply device 1' sends a wireless power supply signal to power receiving device 2''. At this point, power supply device 1' records the transmission time t1 of the wireless power supply signal. Power receiving device 2'' receives the wireless power supply signal. At this point, power receiving device 2'' records the reception time t1' of the wireless signal which is determined to contain the wireless power supply signal. Power receiving device 2'' sends a signal indicating the received power amount, linked to the reception time t1', to power supply device 1'', which then receives it.

[0088] Subsequently, the power supply device 1' compares the transmission time t1 with the reception time t1', and since the reception time t1' falls within the predetermined time period of the transmission time t1, it determines the associated received power amount as an item related to the transmission of the wireless power supply signal.

[0089] The differences in the steps of power supply device 1' and power supply device 1, and the differences in the steps of power receiving device 2'' and power receiving device 2 will be explained. Except for the differences in the steps, the steps are the same as those described in this embodiment. In power supply device 1', in step S12, in addition to transmitting the wireless power supply signal, the clock unit 103 records the transmission time of the wireless power supply signal (step S12'). This transmission time is sent to the control unit 101, but it may be kept in the storage unit 15 until it is used.

[0090] The control unit 101 determines whether the power receiving device 2 has received the wireless power supply signal transmitted by the power supply unit 11, based on the transmission time t1 of the wireless power supply signal by the power supply unit 11 and the reception time t1' of the wireless signal which is determined to contain the wireless power supply signal (step S18). More specifically, the control unit 101 sets a predetermined time period from the transmission time t1 of the wireless power supply signal by the power supply unit 11, and the power receiving device 2 determines whether or not the reception time t1' is included in that time period. It is desirable that this step S18 occurs between steps S13 and S15 of the power supply device 1. If the control unit 101 determines that the power receiving device 2 has received the wireless power supply signal transmitted by the power supply unit 11 (step S18: Yes), the control unit 101 proceeds to step S14 (if step S18 is between steps S13 and S14) or step S15 (if step S18 is between steps S14 and S15). If the control unit 101 determines that the power receiving device 2 has not received the wireless power supply signal transmitted by the power supply unit 11 (step S18: No), the process returns to step S11.

[0091] In the power receiving device 2”, the control unit 201 generates and transmits information indicating the time t1' when it is determined that the radio signal is included in the signal indicating the amount of power received in step S26 (step S26').

[0092] By using this modified method, the power supply device 1 can determine whether the power receiving device 2 has received the wireless power supply signal, and can then send a signal requesting measurement of the power received by the power receiving device 2 again.

[0093] (Variation 5) In this embodiment, the power receiving device 2 determined whether the wireless signal it received included a wireless power supply signal from the power supply device 1. In this modified example, the power receiving device 2 does not make this determination, but instead measures the DC power of the received wireless signal and generates and transmits a signal indicating the amount of power received, using the statistical amount of this DC power as the amount of power received.

[0094] In this case, the power receiving device 2 does not have step S25 to verify the conditions of the feature quantity. After performing step S24 of receiving the wireless signal and measuring the feature quantity (DC power), it proceeds to step S26, which generates and transmits a signal indicating the amount of power received using the measured DC power statistics as the amount of power received. Examples of DC power statistics include the minimum, maximum, mean, median, and variance of DC power. These statistics may also be time-series data. The other steps are the same as those of the power receiving device 2 in this embodiment.

[0095] The power supply device 1 uses characteristic quantities of the DC power sent from the power receiving device 2 to perform step S14, which verifies whether the amount of power received by the power receiving device 2 satisfies predetermined conditions. The other steps are the same as those of the power supply device 1 in this embodiment.

[0096] By using this modified configuration, it is possible to determine whether the power receiving device 2 received the wireless power transmission signal from the power supply device 1, rather than from the power receiving device 2.

[0097] (Experimental variation 6) In this embodiment, the frequency band (5.7 GHz band) of the wireless power transmission signal transmitted by the power supply device 1 and received by the power receiving device 2 was different from the frequency band (2.4 GHz band) of the wireless communication signal transmitted and received by the power supply device 1 and the power receiving device 2. In this modified example, these frequency bands may be the same. For example, the frequency band of the wireless communication signal transmitted and received by the power supply device 1 and the power receiving device 2 may be a frequency band close to (5 GHz band) that of the wireless power transmission signal, or it may be a closer (similar) frequency band.

[0098] Even if the frequency bands of the wireless power transmission signal and the wireless communication signal are the same, as described in this embodiment, the characteristic quantities of the wireless power transmission signal and the wireless communication signal are different. The power receiving device 2 can determine whether or not a wireless power transmission signal is included by measuring the characteristic quantities of the received wireless signal.

[0099] (Example 7) In this embodiment, amplitude and the time variation of amplitude were used as characteristic quantities of the wireless power transmission signal. In this modified example, the time variation of frequency is used as a characteristic quantity of the wireless power transmission signal. Figure 21 shows an example configuration of the power receiving device 2'” applicable to the first embodiment. The power receiving device 2'” further includes a measuring unit 231 in addition to the power receiving device 2.

[0100] In this modified example, the characteristic quantity of the wireless power transmission signal transmitted by the power supply device 1 is one of the following: the time variation of the frequency is within a positive predetermined range (may be called the fourth range), the time variation of the frequency is within a negative predetermined range (may be called the fifth range), the time variation of the frequency is within a positive predetermined range in the first time period (may be called the sixth range) and within a negative predetermined range in the second time period (may be called the seventh range), and the time variation of the frequency is within a negative predetermined range in the third time period (may be called the eighth range) and within a positive predetermined range in the fourth time period (may be called the ninth range). Note that the case where the time variation of the frequency is positive is called up-chirp, and the case where the time variation of the frequency is negative is called down-chirp. Note that the ranges from the fourth range to the ninth range may be set considering frequency band fluctuations due to amplitude and phase variations called noise, reflection, diffraction, and fading in a real environment.

[0101] Figure 22 shows examples of the frequencies of the wireless power transmission signals of the power supply device 1 in modified cases. Sig1 represents an example of a wireless power transmission signal where the time variation of the frequency is within the positive fourth range, Sig2 represents an example of a wireless power transmission signal where the time variation of the frequency is within the negative fifth range, Sig3 represents an example of a wireless power transmission signal where the time variation of the frequency is within the positive sixth range in the first time zone and within the negative seventh range in the second time zone, and Sig4 represents an example of a wireless power transmission signal where the time variation of the frequency is within the positive eighth range in the third time zone and within the negative ninth range in the fourth time zone.

[0102] The measurement unit 231 (which may also be called the second measurement unit) measures the time change in the frequency of the radio signal received via the antenna 22. The measurement unit 231 sends the radio signal to the rectifier 211 and sends information indicating the time change in the measured frequency to the control unit 201. The measurement unit 231 and the control unit 201 may determine whether the received radio signal includes a radio power supply signal based on the time change in the frequency of the radio signal.

[0103] The differences between the operation steps of power receiving device 2'" and power receiving device 2 will be explained. Step S24 measures the feature quantity by measuring the time change in the frequency of the received radio signal by the measurement unit 231 (step S24'). The confirmation of whether the feature quantity conditions are met in step S25 is performed by the control unit 201 based on the time change in the frequency of the received radio signal (step S25"). More specifically, if the time change in the frequency of the received radio signal falls within any of the ranges from the 4th range to the 9th range, the control unit 201 determines that the received radio signal contains the radio power supply signal transmitted by power supply device 1.

[0104] As shown in this modified example, the power receiving device 2 can determine whether or not the received wireless signal contains a wireless power supply signal by measuring the time variation of the frequency of the received wireless signal as a feature.

[0105] (Variation 8) In this embodiment, amplitude and the time variation of amplitude were used as feature quantities of the wireless power transmission signal. In this modified example, the frequency spectrum is used as the feature quantity of the wireless power transmission signal. Figure 22 shows an example configuration of the power receiving device 2''' applicable to the first embodiment. The power receiving device 2''' further includes a measuring unit 241 in addition to the power receiving device 2.

[0106] The measurement unit 241 (which may also be called the third measurement unit) measures the frequency spectrum of the radio signal received via the antenna 22. The measurement unit 241 sends the radio signal to the rectifier 211 and sends information indicating the measured frequency spectrum to the control unit 201. The measurement unit 231 and the control unit 201 may determine whether the received radio signal includes a radio power supply signal based on the frequency spectrum of the radio signal. More specifically, the control unit 201 may determine whether the received radio signal includes a radio power supply signal based on at least one of the width and time variation of the frequency spectrum of the radio signal.

[0107] In this modified example, the power supply device 1 transmits the wireless power supply signal as an unmodulated sine wave. In this wireless power supply signal, the frequency spectrum in a predetermined frequency band (which may be called the first frequency band) is within a predetermined width. Also, in this wireless power supply signal, the time variation of the frequency spectrum is within a predetermined range. The predetermined width of the frequency spectrum and the predetermined range of the time variation of the frequency spectrum may be set considering noise, reflection, diffraction, and amplitude and phase fluctuations called fading in the actual environment. The frequency spectrum of the wireless communication signal differs from the wireless power supply signal in this modified example in that it has a width exceeding the predetermined width and its time variation exceeds the predetermined range.

[0108] The differences between the operation steps of the power receiving device 2'' and the operation steps of the power receiving device 2 will be explained. Step S24, the measurement of the feature quantity, involves the measurement unit 241 measuring the frequency spectrum of the received radio signal (step S24'). The confirmation of whether the feature quantity conditions are met in step S25 is performed by the control unit 201 based on at least one of the width and time variation of the frequency spectrum of the received radio signal (step S25''). More specifically, the control unit 201 determines that the received radio signal contains the radio power supply signal transmitted by the power supply device 1 if the width of the frequency spectrum of the received radio signal falls within a predetermined range in a predetermined frequency band, or if the time variation of the frequency spectrum of the received radio signal falls within a predetermined range.

[0109] As shown in this modified example, the power receiving device 2 can determine whether or not the received wireless signal contains a wireless power transmission signal by measuring the frequency spectrum of the received wireless signal as a feature.

[0110] Modified versions of the power supply device 1 and the power receiving device 2 have been described above. The power supply device in this embodiment and its modified versions transmits a wireless power supply signal that includes different feature quantities from the wireless communication signal. The power receiving device in this embodiment and its modified versions determines whether the received wireless signal contains a wireless power supply signal based on the feature quantities of the received wireless signal. This allows the power receiving device to distinguish between a wireless power supply signal and other wireless communication signals.

[0111] While several embodiments of the present invention have been described, these embodiments are presented as examples only and are not intended to limit the scope of the invention. These novel embodiments can be implemented in a variety of other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included within the scope and spirit of the invention, as well as within the scope of the invention and its equivalents as described in the claims.

[0112] With regard to the embodiments described above, the following additional information is disclosed.

[0113] [1] A power receiving unit that receives and receives power from a wireless signal including at least one of a wireless power supply signal and a wireless communication signal, A processing unit that determines whether the wireless signal includes the wireless power supply signal based on the characteristic quantities of the wireless signal, Equipped with, Power receiving device.

[0114] [2] A communication unit receives a first signal from a power supply device, which is the source of the wireless power supply signal, indicating a request to measure the amount of power to be received by the power receiving device. A first measuring unit that measures the amount of power received by the aforementioned wireless signal, Furthermore, The processing unit generates a second signal based on the first signal, indicating the amount of power received by a wireless signal that is determined to contain the wireless power supply signal within a predetermined time. The communication unit transmits the second signal to the power supply device. [1] The power receiving device described above.

[0115] [3] The system further includes a first measuring unit that measures the amount of power received by the aforementioned wireless signal, The processing unit generates a second signal indicating the amount of power received by the wireless signal when the power receiving unit receives a wireless signal that is determined to contain the wireless power transmission signal during a period from a first time length to a second time length based on the time length for which the power supply device transmits the wireless power transmission signal. The system further comprises a communication unit that transmits the second signal to the power supply device. [1] The power receiving device described above.

[0116] [4] The system further includes a first measuring unit that measures the amount of power received by the aforementioned wireless signal, The processing unit includes a clock unit that records a first time, which is the time when the wireless signal, which is determined to include the wireless power supply signal, is received. The processing unit generates a second signal indicating the amount of power received by a wireless signal that is determined to contain the wireless power supply signal within a predetermined time, and the first time. The system further includes a communication unit that transmits the second signal to a power supply device which is the source of the wireless power supply signal. [1] The power receiving device described above.

[0117] [5] The power receiving unit receives power by converting the wireless signal into DC power. The processing unit determines whether the wireless signal includes the wireless power supply signal based on at least one of the value of the DC power and the time variation of the DC power as characteristic quantities of the wireless signal. A power receiving device as described in any one of [1] to [4].

[0118] [6] The processing unit determines that the wireless signal includes the wireless power supply signal if, within a predetermined time, the value of the DC power is within a first range, the time variation of the DC power is within a positive second range, or the time variation of the DC power is within a negative third range. [5] The power receiving device described above.

[0119] [7] The system further includes a second measuring unit that measures at least one of the frequency and the time variation of the aforementioned wireless signal. The processing unit determines whether the wireless signal includes the wireless power supply signal based on the time variation of the frequency as a characteristic quantity of the wireless signal. A power receiving device as described in any one of [1] to [6].

[0120] [8] The processing unit determines that the wireless signal includes the wireless power supply signal if, within a predetermined time, the time variation of the frequency is within the positive fourth range, the time variation of the frequency is within the negative fifth range, the time variation of the frequency is within the positive sixth range in the first time period and within the negative seventh range in the second time period, or the time variation of the frequency is within the negative eighth range in the third time period and within the positive ninth range in the fourth time period. [7] The power receiving device described above.

[0121] [9] The system further comprises a third measuring unit for measuring the frequency spectrum of the aforementioned wireless signal, The processing unit determines whether the wireless signal includes the wireless power transmission signal based on at least one of the width of the frequency spectrum in a first frequency range and the time variation of the frequency spectrum as characteristic quantities of the wireless signal. A power receiving device as described in any one of [1] to [8].

[0122]

[10] A processing unit that generates a wireless power transmission signal containing different features from wireless communication signals, A power supply unit that transmits the aforementioned wireless power supply signal, Equipped with, Power supply device.

[0123]

[11] The processing unit generates a first signal indicating a request to measure the amount of power received by the power receiving device, which is the destination of the wireless power transmission signal. The first signal is transmitted to the power receiving device, The system further includes a communication unit that, after transmitting the aforementioned wireless power supply signal, receives a second signal from the power receiving device indicating the amount of power received by the power receiving device. The processing unit determines, based on the second signal, at least one of the time period, duration, amplitude, phase, frequency band, and direction for transmitting the wireless power transmission signal. The power supply device described in

[10] .

[0124]

[12] The processing unit generates a first signal indicating a request to measure the amount of power received by the power receiving device, which is the destination of the wireless power transmission signal. The first signal is transmitted to the power receiving device, The system further includes a communication unit that, after transmitting the aforementioned wireless power supply signal, receives a second signal from the power receiving device indicating the amount of power received by the power receiving device. The processing unit generates the first signal if the communication unit does not receive the second signal within a predetermined time, if the amount of power received by the power receiving device included in the second signal is less than or equal to a predetermined value, or if the communication unit receives a signal from the power receiving unit requesting retransmission of the first signal. The communication unit transmits the first signal. The power supply device described in

[10] .

[0125]

[13] The processing unit generates a first signal indicating the time length for transmitting the wireless power transmission signal to the receiving device, which is the destination of the wireless power transmission signal. The first signal is transmitted to the power receiving device, The system further includes a communication unit that, after transmitting the aforementioned wireless power supply signal, receives a second signal from the power receiving device indicating the amount of power received by the power receiving device. The processing unit determines, based on the second signal, at least one of the time period, duration, amplitude, phase, frequency band, and direction for transmitting the wireless power transmission signal. The power supply device described in

[10] .

[0126]

[14] The processing unit includes a clock unit that records the first time for transmitting the wireless power supply signal, The system further includes a communication unit that, after transmitting the aforementioned wireless power supply signal, receives a second signal from the power receiving device, which includes a second timestamp indicating the amount of power received by the power receiving device and the timestamp of the reception of a wireless signal that is determined to contain the aforementioned wireless power supply signal. The processing unit determines, based on the first time and the second time, whether or not the power receiving device has received the wireless communication signal. The power supply device described in

[10] .

[0127]

[15] The system further includes a communication unit that, after transmitting the aforementioned wireless power supply signal, receives a second signal from the power receiving device indicating the amount of power received by the power receiving device. The second signal includes information indicating the statistics of the received power, The processing unit determines, based on the second signal, at least one of the time period, duration, amplitude, phase, frequency band, and direction for transmitting the wireless power transmission signal. The power supply device described in

[10] .

[0128]

[16] The processing unit generates the wireless power transmission signal, in which the different feature quantities are one of the following: the amplitude is within a first range, the time variation of the amplitude is within a positive second range, or the time variation of the amplitude is within a negative third range. A power supply device as described in any one of

[10] to

[15] .

[0129]

[17] The processing unit generates a wireless power transmission signal in which, as the different feature quantity, the time variation of the frequency is within a positive fourth range, the time variation of the frequency is within a negative fifth range, the time variation of the frequency is within a positive sixth range in the first time period and within a negative seventh range in the second time period, and the time variation of the frequency is within a negative eighth range in the third time period and within a positive ninth range in the fourth time period. The power supply device described in

[10] to

[16] .

[0130]

[18] A power receiving device described in any one of [1] to [9], A power supply device described in any one of

[10] to

[17] , Equipped with, Power supply system.

[0131]

[19] Receiving a radio signal including a wireless power transfer signal or a wireless communication signal, A method for determining whether the wireless signal includes the wireless power supply signal based on the characteristic quantities of the wireless signal.

[0132]

[20] A wireless power transmission signal is generated that contains different features from wireless communication signals. Transmits the aforementioned wireless power supply signal, method. [Explanation of Symbols]

[0133] 1,1': Power supply device 2,2A,2B,2',2",2'",2"": Power receiving device 3: Wireless communication terminals 10,10': Processing section 11: Power supply section 12: Antenna 13: Communications Department 14: Antenna 15: Storage part 20,20': Processing section 21,21': Power receiving section 22: Antenna 23: Measuring part 24: Communications Department 25: Antenna 26: Storage section 100: Power supply system 101: Control Unit 102:Calculation section 103: Clock section 201: Control Unit 202:Calculation Department 203: Clock section 211: Rectifier 212: Load 221: Matching box 222: DC-DC converter 231:Measurement part 241:Measurement part

Claims

1. A power receiving unit that receives power and converts the signal based on the power received into DC power, A measuring unit for measuring the amount of energy of the DC power, A processing unit that determines whether the amplitude of the signal based on the power reception is constant based on whether the amount of power falls within a predetermined range, A communication unit that, when it is determined that the amplitude is constant, transmits a signal containing information about the amount of power, and when it is determined that the amplitude is not constant, does not transmit the signal. A power receiving device equipped with the following features.

2. A power receiving unit that receives power and converts a signal based on the power received into DC power, A measuring unit for measuring the amount of energy of the DC power, A processing unit that determines whether the amplitude of the signal based on the power reception decreases by a certain percentage according to the amount of power, and whether the amplitude of the signal based on the power reception increases by a certain percentage, A power receiving device equipped with the following features.

3. When it is determined that the amplitude decreases or increases by a certain rate, a signal containing information about the amount of power is transmitted. If the communication unit determines that the amplitude does not decrease at a constant rate and does not increase at a constant rate, it will not transmit the signal. The power receiving device according to claim 2, further comprising:

4. A power receiving unit that receives power and converts the signal based on the power received into DC power, A measuring unit for measuring the amount of energy of the DC power, A processing unit that determines whether the received second time length matches the first time length, A communication unit that, when it is determined that the second time length matches the first time length, transmits a signal containing information about the amount of power, and when it is determined that the second time length does not match the first time length, does not transmit the signal. To have a power receiving device.

5. The power receiving device according to claim 4, wherein the communication unit receives a wireless signal indicating a first time length for which the power supply device wirelessly supplies power.

6. The communication unit receives a first signal indicating a request to measure the amount of power. The power receiving device according to claim 1 or claim 3.

7. The system further includes a measuring unit for measuring the aforementioned amount of electrical energy, The processing unit includes a clock unit that records the first time the power receiving unit receives power, When the communication unit determines that the second time length matches the first time length, it transmits a signal indicating the first time along with information regarding the amount of power. The power receiving device according to claim 4.

8. A power receiving unit that receives power, A measuring unit for measuring the frequency of the signal based on the aforementioned power reception, The system includes a processing unit that determines whether the time variation of the frequency is within a predetermined positive range or within a predetermined negative range, and Power receiving device.

9. The processing unit determines within a predetermined time whether any one of the following cases applies: the time change of the frequency is within the positive fourth range; the time change of the frequency is within the negative fifth range; the time change of the frequency is within the positive sixth range in the first time period and within the negative seventh range in the second time period; or the time change of the frequency is within the negative eighth range in the third time period and within the positive ninth range in the fourth time period. The power receiving device according to claim 8.

10. A power receiving unit that receives power, A measuring unit that measures the frequency spectrum based on the received signal, A processing unit that determines whether at least one of the width of the frequency spectrum and the time variation of the frequency spectrum in a first frequency range is within a predetermined range, A power receiving device equipped with the following features.

11. A power receiving device according to any one of claims 1 to 5, or any one of claims 7 to 10, A power supply device, A processing unit that controls the power supply, A communication unit receives a signal from a power receiving device indicating the amount of power received, which is generated based on the DC power measured in the power receiving device in accordance with the power supply. Equipped with, The processing unit causes the power supply to be performed based on the signal indicating the amount of power received. A power supply system comprising a power supply device.

12. The power supply device further comprises a power supply unit which is powered by the processing unit of the power supply device, The power supply system according to claim 11.

13. The processing unit of the power supply device determines at least one of the time period, duration, amplitude, phase, frequency band, or direction of power supply based on the signal indicating the amount of power received. The power supply system according to claim 11.

14. The signal indicating the amount of power received includes information indicating the statistics of the DC power, The power supply system according to claim 11.

15. A power receiving device according to any one of claims 1 to 5, or any one of claims 7 to 10, A power supply device that provides power, A power supply system equipped with the following features.

16. Receiving power, converting the signal based on the power reception into DC power, The amount of energy of the aforementioned DC power is measured, Whether the amount of power falls within a predetermined range determines whether the amplitude of the signal based on the power reception is constant. If it is determined that the amplitude is constant, a signal containing information about the amount of power is transmitted; if it is determined that the amplitude is not constant, the signal is not transmitted. method.

17. Receiving power, converting the signal based on the power reception into DC power, The amount of energy of the aforementioned DC power is measured, Whether the amount of power falls within a predetermined range determines whether the amplitude of the signal based on the power reception decreases at a constant rate, or whether the time change of the amount of power falls within a positive predetermined range determines whether the amplitude of the signal based on the power reception increases at a constant rate. method.

18. When it is determined that the amplitude decreases or increases by a certain rate, a signal containing information about the amount of power is transmitted. If it is determined that the amplitude does not decrease at a constant rate and does not increase at a constant rate, the signal is not transmitted. The method according to claim 17, further comprising the above.

19. Receiving power, converting the signal based on the power reception into DC power, The amount of energy of the aforementioned DC power is measured, Determine whether the received second time length matches the first time length. If it is determined that the second time length matches the first time length, a signal containing information about the amount of power is transmitted; if it is determined that the second time length does not match the first time length, the signal is not transmitted. method.

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