Wireless power supply system

Abstract

To provide a wireless power supply system which enables a receiver to stably receive power supply from multiple transmitters.SOLUTION: A wireless power supply system comprises a first transmitter, a second transmitter, and at least one receiver. The first transmitter and the second transmitter can wirelessly supply electric power to the receiver via power supply radio waves. The center frequency of the power supply radio waves of the first transmitter differs from the center frequency of the power supply radio waves of the second transmitter. The power supply radio waves of the first transmitter and the second transmitter are wireless radio waves which can be regarded as substantially uninterrupted continuous waves.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a wireless power supply system. [Background technology]

[0002] 2. Description of the Related Art Techniques for wirelessly transmitting power are known. Patent Document 1 discloses a technique for providing an electronic device and a power supply method that realizes efficient power supply to a terminal. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-154195 A Summary of the Invention [Problem to be solved by the invention]

[0004] In a wireless power supply system, there is a problem that a receiver may not be able to stably receive power supply from a plurality of transmitters. Therefore, the present disclosure has been made to solve the above problem, and has an object to provide a technique that enables a receiver to stably receive power supplies from a plurality of transmitters. [Means for solving the problem]

[0005] A wireless power supply system comprising a first transmitter, a second transmitter, and at least one receiver, wherein the first transmitter and the second transmitter are capable of wirelessly supplying power to the receiver via power supply radio waves, the center frequency of the power supply radio waves of the first transmitter being different from the center frequency of the power supply radio waves of the second transmitter, and the power supply radio waves of the first transmitter and the second transmitter being radio waves that can be regarded as approximately continuous waves. Effect of the Invention

[0006] According to the present disclosure, it is possible to provide a technique that enables a receiver to stably receive power supply from a plurality of transmitters in a wireless power supply system. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a diagram showing the overall configuration of a WPT system 1 according to an embodiment of the present invention. [Diagram 2] 1 is a block diagram showing an example configuration of a first transmitter 100, a second transmitter 110, and a receiver 200. FIG. [Diagram 3] FIG. 2 is a block diagram showing the functional configuration of a control device C10. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings. In all the drawings explaining the embodiment, the same reference numerals are given to common components, and repeated explanations are omitted. Note that the following embodiment does not unduly limit the contents of the present disclosure described in the claims. In addition, not all of the components shown in the embodiment are essential components of the present disclosure. In addition, each figure is a schematic diagram and is not necessarily illustrated strictly.

[0009] <1 Overall system configuration> FIG. 1 is a diagram showing the overall configuration of a WPT system 1 according to this embodiment.

[0010] The WPT system 1 shown in Fig. 1 includes, for example, a first transmitter 100, a second transmitter 110, a receiver 200, a first information processing device 300, and a second information processing device 400. The WPT system 1 shown in Fig. 1 is used, for example, in a building or a factory. Note that the connection between the first transmitter 100, the second transmitter 110, and the first information processing device 300, and the connection between the first information processing device 300 and the second information processing device 400 may be wired or wireless.

[0011] 1 shows an example in which the WPT system 1 includes three transmitters (first transmitter 100, second transmitter 110, and third transmitter 120), but the number of transmitters included in the WPT system 1 is not limited to three. The number of transmitters included in the WPT system 1 may be two or less, or may be four or more.

[0012] 1 shows an example in which the WPT system 1 includes seven receivers 200, but the number of receivers 200 included in the WPT system 1 is not limited to seven. The number of receivers 200 included in the WPT system 1 may be six or less, or eight or more.

[0013] The first transmitter 100 and the second transmitter 110 are capable of wirelessly supplying power to the multiple receivers 200 via power supply waves. The first transmitter 100 and the second transmitter 110 are capable of wirelessly communicating information with a plurality of receivers 200 via communication radio waves.

[0014] The power supply waves of the first transmitter 100 and the second transmitter 110 may be radio waves that can be regarded as substantially continuous waves. The power supply signals transmitted from the first transmitter 100 and the second transmitter 110 are radio frequency signals having a predetermined power, and it is preferable to provide this radio frequency signal with a pause period of any period that is short compared to periods other than the pause period, thereby making it a radio frequency signal that can be regarded as a substantially continuous wave. Specifically, the power feed signal (power feed radio wave) transmitted from the first transmitter 100 and the second transmitter 110 may be, for example, a continuous wave (CW) having a predetermined power. Also, the frequency band of the power feed signal is, for example, a 920 MHz band, taking into consideration the distance between the first transmitter 100 and the second transmitter 110 and the receiver 200. If the frequency band is higher than the exemplified frequency band, it may not be possible to feed a predetermined power that allows the receiver 200 to operate unless the distance between the first transmitter 100 and the second transmitter 110 and the receiver 200 is shortened, so an appropriate frequency band can be determined by taking into consideration a practical range (for example, the distance between the first transmitter 100 and the second transmitter 110 and the receiver 200 is several meters). In this disclosure, the frequencies of the radio waves transmitted by the first transmitter 100 and the second transmitter 110 differ from each other, centering on the 920 MHz band.

[0015] In this case, the laws of the country in which the WPT system 1 is installed may impose restrictions on the intermittent transmission of a power supply signal having a predetermined power. As an example, when the power supply signal from the first transmitter 100 and the second transmitter 110 corresponds to the provisions of a radio station stipulated in the Radio Law of Japan (regardless of whether a license is available), it may be necessary to provide a certain pause period for the power supply signal based on the Radio Law. In this case, the power supply signal cannot be considered as a continuous wave when considered on a certain time axis. However, since it is essential to provide a pause period and this pause period is sufficient if it is short, the power supply signal transmitted from the first transmitter 100 and the second transmitter 110 can be considered as a substantially continuous continuous wave. As described above, the ratio between the duration of the power supply signal and the pause period may be such that the power supply signal transmitted from the first transmitter 100 and the second transmitter 110 can be considered as a substantially continuous continuous wave, and as an example, the pause period is about 1 / 50 to 1 / 100 of the duration of the power supply signal.

[0016] The power supply radio waves of the first transmitter 100 and the second transmitter 110 are preferably unmodulated radio waves that do not contain any modulated signal and carry no information. Specifically, there is a type of radio wave that indicates the characteristics of radio waves generally used in communication systems. The type of radio wave is expressed as a three-letter string that combines letters or numbers that indicate the type of modulation of the main carrier wave, the nature of the signal that modulates the main carrier wave, and the type of transmitted information. The type of modulation of the main carrier wave is one of the following: no modulation: N, amplitude modulation (double sideband): A, amplitude modulation (single sideband, full carrier): H, amplitude modulation (single sideband, reduced carrier): R, amplitude modulation (single sideband, suppressed carrier): J, amplitude modulation (independent sideband): B, amplitude modulation (independent sideband): C, angle modulation (frequency modulation): F, angle modulation (phase modulation): G, and amplitude modulation and angle modulation modulated simultaneously or in a certain sequence: D. The nature of the signal modulating the main carrier wave is one of the following: no modulating signal: 0; a single channel of a digital signal without a subcarrier: 1; a single channel of a digital signal with a subcarrier: 2; a single channel of an analog signal: 3; two or more channels of a digital signal: 7; two or more channels of an analog signal: 8; a combination of one or more channels of an analog signal and one or more channels of a digital signal: 9. The type of transmitted information is one of the following: no information: N, telegraph (auditory reception): A, telegraph (automatic reception): B, facsimile: C, data transmission, remote measurement, and remote command: D, telephone (acoustic): E, television (visual): F, or a combination of N through F: W. In this disclosure, the radio wave type of the power supply radio waves of the first transmitter 100 and the second transmitter 110 is N0N, where N is unmodulated, 0 is a single channel of a digital signal without a subcarrier, and N is no information. In this case, the power supply radio waves indicate that the main carrier is not modulated (unmodulated), there is no digital signal (single channel of a digital signal without a subcarrier), and there is no information to be transmitted (no information). This allows for stable energy transmission by reducing interference with other surrounding communication systems due to the lack of modulation. Also, because it is unmodulated, the transmission energy is concentrated on the carrier wave. This allows for efficient energy transmission between the transmitter and receiver. Since it does not transmit information, the system is simple, and the design and implementation of the transmitter and receiver can be simplified.

[0017] In this specification, the first transmitter 100 and the second transmitter 110 are the (power) first transmitter 100 and the (power) second transmitter 110 in the sense of wirelessly transmitting power, and similarly, the receiver 200 is the (power) receiver 200 in the sense of wirelessly receiving power. As described later, the receiver 200 transmits, for example, information on the state of the receiver 200 or information on the measurement result by a sensor to the first transmitter 100 and the second transmitter 110 as a data signal (communication radio wave), and the first transmitter 100 and the second transmitter 110 may receive such a data signal. In this case, the first transmitter 100 and the second transmitter 110 are receivers that receive the data signal, and the receiver 200 functions as a transmitter that transmits the data signal.

[0018] 1 shows an example in which the WPT system 1 includes two first information processing devices 300, but the number of first information processing devices 300 included in the WPT system 1 is not limited to two. The number of first information processing devices 300 included in the WPT system 1 may be one, or three or more.

[0019] The following describes the relationship between the first transmitter 100, the receiver 200, the first information processing device 300, the second information processing device 400, etc. Since the second transmitter 110 is similar to the first transmitter 100, a detailed description thereof will be omitted.

[0020] The first transmitter 100 transmits, for example, a power supply signal or a data signal to the receiver 200. The first transmitter 100 transmits a power supply signal to the receiver 200 by radio waves in the 920 MHz band, for example. The first transmitter 100 transmits a data signal to the receiver 200 by radio waves in the 2.4 GHz band, for example. The first transmitter 100 may transmit a data signal by radio waves in the 920 MHz band.

[0021] The first transmitter 100 may, for example, feed power to one receiver 200, or may feed power to multiple receivers 200. The first transmitter 100 may, for example, transmit a data signal to one receiver 200, or may transmit a data signal to multiple receivers 200. The first transmitter 100 may, for example, transmit the same data signal as another first transmitter 100, or may transmit a data signal different from that of the other first transmitters 100. The first transmitter 100 may, for example, transmit a predetermined command signal as a data signal to the receiver 200, or may transmit a preset signal as a data signal to the receiver 200.

[0022] The first transmitter 100 receives, for example, a data signal transmitted from the receiver 200. The first transmitter 100 may receive, for example, a data signal transmitted from one receiver 200, or may receive data signals transmitted from a plurality of receivers 200. The first transmitter 100 transmits the data signal transmitted from the receiver 200 to the first information processing device 300. The first transmitter 100 transmits information related to the state of the first transmitter 100 to the first information processing device 300.

[0023] The receiver 200 receives, for example, a power supply signal or a data signal transmitted from the first transmitter 100. For example, if the receiver 200 has a power storage unit, the receiver 200 converts the power supply signal transmitted from the first transmitter 100 into electric power and stores the converted electric power in the power storage unit. For example, if the receiver 200 has a predetermined sensor, the receiver 200 converts the power supply signal transmitted from the first transmitter 100 into electric power and drives the sensor with the converted electric power.

[0024] The receiver 200 transmits, for example, information relating to the state of the receiver 200 or information relating to the measurement results of a sensor to the first transmitter 100 as a data signal.

[0025] The first information processing device 300 is an information processing device that monitors the operation of the first transmitter 100 and the receiver 200 housed in the WPT system 1. For example, the first information processing device 300 determines whether the first transmitter 100 or the receiver 200 is in a preset state based on information on the state of the first transmitter 100 and the receiver 200 transmitted from the first transmitter 100. If it is determined that the first information processing device 300 is in a preset state, the first information processing device 300 transmits predetermined information to the second information processing device 400.

[0026] Furthermore, the first information processing device 300 accumulates information on the first transmitter 100 and the receiver 200 accommodated in the WPT system 1. For example, the first information processing device 300 stores information on the states of the first transmitter 100 and the receiver 200 transmitted from the first transmitter 100 in a storage unit provided in the first information processing device 300.

[0027] Moreover, the first information processing device 300 controls the operation of the first transmitter 100 accommodated in the WPT system 1. For example, the first information processing device 300 transmits a predetermined instruction or information to the first transmitter 100.

[0028] In addition, the first information processing device 300 controls the operation of the second information processing device 400 .

[0029] The second information processing device 400 is, for example, an information processing device operated by an administrator of the WPT system 1. When the second information processing device 400 receives a notification from the first information processing device 300 that the first transmitter 100, the receiver 200, or both of them housed in the WPT system 1 are in a predetermined state, the second information processing device 400 presents to the user that the first transmitter 100, the receiver 200, or both of them are in the predetermined state.

[0030] In addition, the second information processing device 400 analyzes information on the status of the first transmitter 100 and the receiver 200 stored in the first information processing device 300, and presents predetermined information to the user. The predetermined information is, for example, the following: Information regarding the location of the first transmitter 100 Information regarding the placement of the receiver 200 Power consumption information Information on power consumption

[0031] <Transmitter and receiver configuration> FIG. 2 is a block diagram showing an example of the configuration of the first transmitter 100 and the receiver 200 shown in FIG. 1. As shown in FIG. 2, the first transmitter 100 and the receiver 200 are, for example, spaced apart from each other at a predetermined interval. For example, the first transmitter 100 and the receiver 200 are installed at a distance of about several meters. Specifically, for example, the first transmitter 100 is fixedly installed at a predetermined high position provided in a high place indoors, for example, on a ceiling or a wall. The receiver 200 is installed in a predetermined device indoors, or placed near a device that requires power supply. The receiver 200 may also be carried by a user. The first transmitter 100 transmits a power supply signal to the receiver 200 by radio waves of a predetermined frequency, for example, 920 MHz band. The receiver 200 converts the power supply signal transmitted from the first transmitter 100 into power, and charges the converted power or supplies the converted power to a predetermined device.

[0032] The first transmitter 100 includes, for example, an oscillator 101, a transmitting antenna 102, a microcomputer (controller) 103, a data transceiver 104, a data transmitting / receiving antenna 105, a capacitor, a PLL 107, a power amplifier 108, and a power supply 109. The oscillator 101, the microcomputer 103, the data transceiver 104, the data transmitting / receiving antenna 105, the capacitor, the PLL 107, the power amplifier 108, and the power supply 109, or a combination of at least any of these, may be mounted on, for example, a PCB (printed circuit board).

[0033] The oscillator 101 oscillates a signal in a predetermined frequency band, for example, the 920 MHz band. The oscillated signal may be amplified and unnecessary frequency components may be removed, if necessary.

[0034] The transmitting antenna 102 is formed so as to be capable of efficiently transmitting radio waves in the 920 MHz band, for example. The transmitting antenna 102 radiates a signal oscillated by an oscillator 101 as a power supply signal.

[0035] The microcomputer 103 controls the operation of the first transmitter 100. The microcomputer 103 is realized, for example, by a semiconductor element equipped with an ARM processor. The microcomputer 103 controls, for example, the transmission of radio waves by the transmitting antenna 102. The microcomputer 103 can control the transmission intensity of radio waves by the transmitting antenna 102 by controlling the current and voltage of power supplied to the power amplifier 108.

[0036] The data transceiver 104 performs processes such as converting digital data to analog data, modulating analog data, etc. The data transceiver 104 also performs processes such as demodulating a data signal received by the data transceiver antenna 105, and digitizing the demodulated data. For example, the data transceiver 104 extracts a predetermined signal from the data signal received by the data transceiver antenna 105, converts it into digital data, and transmits it to the microcomputer 103.

[0037] The data transmission / reception antenna 105 is formed to be capable of efficiently transmitting and receiving radio waves in the 2.4 GHz band, for example. The data transmission / reception antenna 105 radiates a data signal supplied from the data transceiver 104. In addition, the data transmission / reception antenna 105 receives a data signal transmitted from the receiver 200.

[0038] The capacitor is provided between the PLL 107, the power supply 109, and GND (ground, 0V), and serves as a bypass capacitor for generating a high-quality signal. The capacitor may be connected to the PLL 107 and serve as a low-pass filter for generating a high-quality signal and removing unnecessary high-frequency components. The low-pass filter includes a resistor and a capacitor, and has a function of passing high-frequency components to the capacitor and passing low-frequency components. By installing a low-pass filter between the oscillator 101 and the PLL 107, it is possible to remove unnecessary high-frequency components and improve the quality of the output signal.

[0039] The PLL 107 is an electronic circuit for controlling frequency and phase, called a Phase-Locked Loop. A capacitor is connected to the PLL, and the frequency of the radio wave transmitted by the transmitting antenna 102 changes according to the capacitance of the capacitor. In this disclosure, the capacitor is provided between the oscillator 101 and the PLL 107.

[0040] The power amplifier 108 is an electronic circuit that amplifies the signal output from the PLL 107 based on the power from the microcomputer 103 and outputs the amplified signal to the transmitting antenna 102 .

[0041] The power supply 109 supplies power to the oscillator 101 and the microcomputer 103 .

[0042] The receiver 200 includes, for example, a receiving antenna 201, a rectifier 202, a power management unit 203, a power storage unit 204, a microcomputer 205, a data transceiver 206, and a data transmitting / receiving antenna 207. The receiving antenna 201, the rectifier 202, the power management unit 203, the power storage unit 204, the microcomputer 205, the data transceiver 206, and the data transmitting / receiving antenna 207, or at least any combination of these, may be mounted on, for example, a PCB or an FPC (flexible printed circuit board).

[0043] The receiving antenna 201 is formed so as to be able to efficiently receive radio waves in the 920 MHz band, for example. The receiving antenna 201 receives the power supply signal radiated from the transmitting antenna 102.

[0044] The rectifier 202 rectifies the radio waves received as a power supply signal and converts them into a DC voltage.

[0045] The power management unit 203 manages the DC voltage. For example, the power management unit 203 controls a charging voltage based on the DC voltage. The power management unit 203 charges the power storage unit 204 by controlling the charging voltage. In addition, for example, when the power storage unit 204 stores power equal to or greater than a predetermined capacity, the power management unit 203 supplies the DC voltage to a connected member.

[0046] Further, the power management unit 203 releases the power stored in the power storage unit 204 in response to control from the microcomputer 205 .

[0047] The power storage unit 204 stores power in response to an instruction from the power management unit 203. The power storage unit 204 is realized by, for example, a battery or a capacitor. Furthermore, the power storage unit 204 releases the stored power in response to an instruction from the power management unit 203.

[0048] The microcomputer 205 controls the operation of the receiver 200. The microcomputer 205 is driven by a DC voltage supplied from the power management unit 203 or by power stored in the power storage unit 204. The microcomputer 205 controls the power management unit 203 to cause the power storage unit 204 to release the power stored therein.

[0049] For example, various sensors can be connected to the receiver 200. For example, a heat sensor, a temperature sensor, a light sensor, a humidity sensor, a vibration sensor, and the like are connected to the receiver 200. The sensors connected to the receiver 200 are driven by, for example, a direct current voltage supplied from the power management unit 203 or power discharged from the power storage unit 204. The microcomputer 205 continuously or intermittently monitors the voltage value at a predetermined portion of the receiver 200, the status of the sensor connected to the receiver 200, information detected by the sensor, and the like. The microcomputer 205 transmits the voltage value at a predetermined portion of the receiver 200, the status of the sensor connected to the receiver 200, information detected by the sensor, and the like as digital data to the data transceiver 206. The sensor may be built into the receiver 200.

[0050] The data transceiver 206 performs processes such as converting digital data supplied from the microcomputer 205 into analog data and modulating the analog data. The data transceiver 206 also performs processes such as demodulating a data signal received by a data transceiver antenna 207 and digitizing the demodulated data. The data transceiver 206 is driven by, for example, a DC voltage supplied from the power management unit 203 or power discharged from the power storage unit 204.

[0051] The data transmission / reception antenna 207 is formed to be capable of efficiently transmitting and receiving radio waves in the 2.4 GHz band, for example. The data transmission / reception antenna 207 radiates a data signal supplied from the data transceiver 206. In addition, the data transmission / reception antenna 207 receives a data signal transmitted from the first transmitter 100. For example, the data transmission / reception antenna 207 is driven by a DC voltage supplied from the power management unit 203 or power discharged from the power storage unit 204.

[0052] <Configuration of control device C10> The control device C10 is an information processing device including a storage unit C101 and a control unit C104. In this disclosure, the control device C10 is disclosed as an information processing device different from the first information processing device 300 and the second information processing device 400, but the first information processing device 300 or the second information processing device 400 may have the functions of the control device C10. In other words, the control device C10 may be the first information processing device 300 or the second information processing device 400. Furthermore, the functions of the control device C10 may be included in at least one of the multiple first transmitters 100 and may be realized as part of the functions of the first transmitter 100. In other words, the processes executable by the control device C10 may be executed by the first transmitter 100. In other words, the first transmitter 100 may include as a part thereof the hardware and software configuration of the control device C10. For example, any one of the multiple first transmitters 100 may act as a parent device (host) of the other first transmitters 100, fulfill the functions of the control device C10, and execute various processes. In other words, the first transmitter 100 acting as the parent device includes, as a part thereof, hardware and software configuration for functioning as the control device C10. All the first transmitters 100 may be configured to include a hardware and software configuration for functioning as the control device C10. In this case, a selected first transmitter 100 may function as a master device and perform the functions of the control device C10. The master device may be selected by an input operation by the user. FIG. 3 is a block diagram showing the functional configuration of the control device C10.

[0053] <Configuration of the memory unit C101 of the control device C10> The memory unit C101 of the control device C10 includes an application program C1011.

[0054] The application program C1011 is a program for causing the control unit C104 of the control device C10 to function as each functional unit. The application program C1011 includes applications such as a web browser application.

[0055] <Configuration of control unit C104 of control device C10> The control unit C104 of the control device C10 executes an application program C1011 stored in the storage unit C101, thereby implementing each functional unit.

[0056] A control device C10 is controllable via wired connections to the multiple transmitters. Specifically, the control device C10 may be wired-connected to a plurality of first transmitters 100 based on any wired connection standard such as Ethernet, USB (Universal Serial Bus), serial connection, etc. The control unit C104 of the control device C10 can control the transmission of the power supply signal and the transmission and reception of data signals of the first transmitter 100 by transmitting a control signal to the first transmitter 100 via the wired connection.

[0057] The control device C10 can control the plurality of transmitters via a wireless connection. Specifically, the control device C10 may be wirelessly connected to a plurality of first transmitters 100 based on any wireless connection standard such as WiFi, Bluetooth (registered trademark), NFC (Near Field Communication), Zigbee (registered trademark), Z-Wave, LTE, etc. The control unit C104 of the control device C10 can control the transmission of the power supply signal and the transmission and reception of data signals of the first transmitter 100 by transmitting a control signal to the first transmitter 100 via the wireless connection.

[0058] <Operation of the WPT System 1> The features of the WPT system 1 in the present disclosure will be described below.

[0059] The center frequency of the power supply radio wave of the first transmitter 100 is different from the center frequency of the power supply radio wave of the second transmitter 110. Specifically, the center frequency refers to a frequency located in the center of the frequency band of the frequency range of the power supply radio waves transmitted by the first transmitter 100 and the second transmitter 110. In this disclosure, the power supply radio waves transmitted by the first transmitter 100 and the second transmitter 110 are assumed to transmit radio waves of the same channel (approximately the same frequency) as defined by the Radio Law. A predetermined reference frequency is assigned to each predetermined channel, and radio waves having a frequency within a range of ±20 ppm (Parts Per Million) from the reference frequency (center frequency) are considered to be radio waves of the same channel. For example, assuming that the reference frequency of a predetermined channel is f, multiple radio waves having frequencies within a range of f × (1±20 / 1,000,000) [Hz] are considered to be radio waves of the same channel. In this disclosure, the definition of the same channel based on the Japanese Radio Act has been described as an example, but is not limited to this. The range of the same channel may be specifically defined based on the laws and regulations of the country of implementation, industry practices, etc. For example, the center frequency may be set to any value within the range of 902 MHz to 928 MHz in the Americas and 865.0 to 865.6 MHz in the European countries. For example, the center frequency of the first transmitter may be 902 MHz and the center frequency of the second transmitter may be 928 MHz. It may also be applied to 24GHz (millimeter wave) and the like.

[0060] In this disclosure, the power supply radio waves transmitted by the first transmitter 100 and the second transmitter 110 are unmodulated radio waves (radio wave type N0N) that have no modulation signal and no information. In such a case, the center frequency is the frequency of the power supply radio waves. The power supply radio waves transmitted by the first transmitter 100 and the second transmitter 110 in this disclosure are of radio wave type N0N. Radio waves of radio wave type N0N are known as unmodulated continuous waves (CW) and should theoretically have a single frequency, but it is difficult to maintain a completely constant frequency in an actual transmitter. For example, changes in the outside temperature in the environment in which the transmitter is installed affect the characteristics of the components of the transmitter (especially the oscillator), and also affect the frequency of the power supply radio waves transmitted by the transmitter. In addition, electronic components such as oscillators, capacitors, and resistors equipped in the transmitter have subtle individual differences during the manufacturing process, which may affect the transmission frequency. Noise from the power supply supplied to the transmitter and instability of the power supply also affect the frequency of the transmitter. In this disclosure, the center frequency will be described as an example where it is the average value of the minimum and maximum values ​​of the power supply radio waves transmitted over a specified period in a specified installation environment in which the first transmitter 100 and the second transmitter 110 are installed.

[0061] The center frequency f1 [Hz] of the power feeding wave of the first transmitter 100 is equal to or less than f2 × (1 + 100 / 1,000,000) [Hz] and equal to or more than f2 × (1 - 100 / 1,000,000) [Hz], where f2 [Hz] is the center frequency of the power feeding wave of the second transmitter 110. The center frequency f1 [Hz] of the power feeding wave of the first transmitter 100 is equal to or more than f2 × (1 + 1 / 1,000,000) [Hz] and equal to or less than f2 × (1 - 1 / 1,000,000) [Hz], where f2 [Hz] is the center frequency of the power feeding wave of the second transmitter 110. When the center frequency of the power supply wave of the first transmitter 100 is f2 [Hz], it is preferable that the center frequency f1 [Hz] of the power supply wave of the second transmitter 110 is greater than or equal to f2 × (1 + 1 / 1,000,000) [Hz] and the center frequency f1 of the first transmitter 100 and the center frequency f2 of the second transmitter 110 differ in a range of greater than or equal to f2 × (1 + 100 / 1,000,000) [Hz]. When the center frequency of the power supply wave of the first transmitter 100 is f2 [Hz], it is preferable that the center frequency f1 [Hz] of the power supply wave of the second transmitter 110 is f2 × (1-1 / 1,000,000) [Hz] or less, and the center frequency f1 of the first transmitter 100 and the center frequency f2 of the second transmitter 110 differ in a range of f2 × (1-100 / 1,000,000) [Hz] or more.

[0062] Specifically, it is preferable that the power supply radio waves transmitted by the first transmitter 100 and the second transmitter 110 differ within the range specified by the Radio Law (±20 ppm, Parts Per Million) based on the reference frequency fc specified by the Radio Law for each specified channel.

[0063] When the center frequency of the power supply wave of the first transmitter 100 is f2 [Hz], it is preferable that the center frequency f1 [Hz] of the power supply wave of the second transmitter 110 be in the range of f2 × (1 + 20 / 1,000,000) [Hz] or less and f2 × (1 - 20 / 1,000,000) [Hz] or more. When the center frequency of the power supply wave of the first transmitter 100 is f2 [Hz], it is preferable that the center frequency f1 [Hz] of the power supply wave of the second transmitter 110 is f2 × (1 + 1,000 / 1,000,000) [Hz] or less and f2 × (1 - 1,000 / 1,000,000) [Hz] or more.

[0064] When the center frequency of the power supply wave of the first transmitter 100 is 920 MHz, the center frequency of the power supply wave of the second transmitter 110 is preferably about 920 MHz ± 9.2 kHz. Specifically, the center frequency of the power supply wave of the second transmitter 110 is preferably different from the center frequency of the power supply wave of the first transmitter 100 by about 920 MHz × (10 / 1,000,000) [Hz] = 9.2 kHz. When the two waves with different frequencies overlap, the amplitude (received power) fluctuates at 9.2 kHz. The fluctuation means that the power both becomes stronger and weaker over time. The shorter the fluctuation between the time when the power becomes stronger and the time when the power becomes weaker, the more robust the behavior is. When the center frequency f1 of the power supply wave of the first transmitter 100 and the center frequency f2 of the power supply wave of the second transmitter 110 differ by about 9.2 kHz, the temporal fluctuation of the supply power is approximately 1 / 9.2 kHz = 100 μsec. In particular, when applied to wireless power supply in sensors used in FA (Factory Automation) devices, beacons, etc., this level of temporal fluctuation of the supply power is suitable because it does not affect the operation of the power supply device.

[0065] When the center frequency of the power supply wave of the first transmitter 100 is f2 [Hz], it is preferable that the center frequency f1 [Hz] of the power supply wave of the second transmitter 110 is f2 × (1 + 0.001 / 1,000,000) [Hz] or more, or f2 × (1 - 0.001 / 1,000,000) [Hz] or less. Specifically, when the center frequency of the power supply wave of the first transmitter 100 is 920 MHz, the center frequency of the power supply wave of the second transmitter 110 is preferably about 920 MHz ± 9.2 Hz. Specifically, the center frequency of the power supply wave of the second transmitter 110 is preferably different from the center frequency of the power supply wave of the first transmitter 100 by about 920 MHz × (0.001 / 1,000,000) [Hz] = 9.2 Hz. When the above two waves with different frequencies overlap, the amplitude (received power) fluctuates at 9.2 Hz. The fluctuation means that the power both becomes stronger and weaker over time. The shorter the fluctuation between the time when the power becomes stronger and the time when the power becomes weaker, the more robust the behavior is. When the center frequency f1 of the power supply wave of the first transmitter 100 and the center frequency f2 of the power supply wave of the second transmitter 110 differ by about 9.2 Hz, the temporal fluctuation of the supply power is approximately 1 / 9.2 Hz = 10 milliseconds. In particular, in an environmental sensor, which is a device for detecting, measuring, and monitoring the environmental conditions of the installation environment (temperature, humidity, air pressure, lighting conditions, acoustic conditions, radiation levels, vibrations, wind speed and direction, or other types of environmental factors, etc.), the storage capacity is large, so such a temporal fluctuation of the supply power is preferable because it does not affect the operation of the power supply device.

[0066] The center frequency of the power wave of the first transmitter 100 and the center frequency of the power wave of the second transmitter 110 can be made different based on the following conditions. The capacitances of the capacitors connected to the output terminals of the first transmitter 100 and the second transmitter 110 are different. Note that the capacitor referred to here is a capacitor included in a low-pass filter that is connected to the PLL 107 and is used to suppress the effects of power supply noise on the radio signal to be transmitted. The capacitor is included in at least the first transmitter 100 or the second transmitter 110. The component characteristics of the first transmitter 100 and the second transmitter 110 differ due to differences in the outside temperatures of the installation environments of the first transmitter 100 and the second transmitter 110. This also includes cases where the temperature characteristics of the first transmitter 100 and the second transmitter 110 change due to differences in the components of the first transmitter 100 and the second transmitter 110. The power supply voltage or power supply current supplied to the first transmitter 100 and the second transmitter 110 is different. Specifically, the microcomputer 103 controls the voltage and current of the power supplied to the PLL 107. Specifically, in the first transmitter 100 and the second transmitter 110, the microcomputer 103 controls the voltage and current of the power supplied to the PLL 107, thereby making the center frequency of the power supply wave of the first transmitter 100 and the center frequency of the power supply wave of the second transmitter 110 different.

[0067] The first transmitter 100 or the second transmitter 110 may make the center frequency of the power supply wave of the first transmitter 100 different from the center frequency of the power supply wave of the second transmitter 110 without receiving communication information from each other. Specifically, it is possible to set the center frequencies of the power supply radio waves transmitted by the first transmitter 100 and the second transmitter 110 to be different from each other in advance. Also, by controlling the center frequencies of the power supply radio waves transmitted by the first transmitter 100 and the second transmitter 110 randomly for each predetermined period according to a predetermined time-varying pattern, the center frequencies of the power supply radio waves transmitted by the first transmitter 100 and the second transmitter 110 can be made different from each other without receiving communication information from each other. This reduces the complexity of the wireless power system, reduces interference between transmitters, improves the efficiency of power transfer, and reduces security risks because no communication is required.

[0068] <Operation of the control device C10> The control of the first transmitter 100 by the control unit C104 of the control device C10 will be described.

[0069] The wireless power supply system (WPT system 1) includes a control device C10 capable of controlling the first transmitter 100 and the second transmitter 110, and the control device C10 controls the center frequency of the power supply radio wave of the first transmitter 100 so as to be different from the center frequency of the power supply radio wave of the second transmitter 110. The center frequencies of the first transmitter 100 and the second transmitter 110 are controlled so as to be different from each other based on at least one or more of the following control means: a temperature control means for controlling the temperature of the first transmitter 100 and the second transmitter 110; a power supply voltage control means for controlling the power supply voltage of the first transmitter 100 and the second transmitter 110; and a power supply current control means for controlling the power supply current to the first transmitter 100 and the second transmitter 110.

[0070] The control device C10 controls the temperature of the components or the outside air temperature by transmitting a control signal to the microcomputer of the first transmitter 100 or the second transmitter 110. As a result, the center frequencies of the first transmitter 100 and the second transmitter 110 are controlled to be different from each other. For example, the temperature may be controlled by controlling the microcomputer 103 included in the first transmitter 100 or the second transmitter 110 to heat up components included in the transmitter. Alternatively, the temperature of the transmitter may be controlled by separately controlling a heater (not shown) or the like included in the transmitter. Also, the temperature of the first transmitter 100 or the second transmitter 110 may be controlled by controlling an air conditioner or the like in the installation environment in which the first transmitter 100 or the second transmitter 110 is installed.

[0071] The control device C10 controls the power supply voltage or power supply current supplied to the PLL 107 by transmitting a control signal to the microcomputer of the first transmitter 100 or the second transmitter. As a result, the center frequencies of the first transmitter 100 and the second transmitter 110 are controlled to be different. Specifically, the microcomputer 103 controls the voltage and current of the power supplied to the PLL 107. Specifically, in the first transmitter 100 and the second transmitter 110, the microcomputer 103 controls the voltage and current of the power supplied to the PLL 107, thereby making the center frequency of the power supply wave of the first transmitter 100 and the center frequency of the power supply wave of the second transmitter 110 different from each other.

[0072] In addition, the first transmitter 100 or the second transmitter 110 may control the center frequency of the power supply wave of the first transmitter 100 to be different from the center frequency of the power supply wave of the second transmitter 110 without receiving communication information from each other. Specifically, it is possible to set the center frequencies of the power supply radio waves transmitted by the first transmitter 100 and the second transmitter 110 to be different from each other in advance. Also, by controlling the center frequencies of the power supply radio waves transmitted by the first transmitter 100 and the second transmitter 110 randomly for each predetermined period according to a predetermined time-varying pattern, the center frequencies of the power supply radio waves transmitted by the first transmitter 100 and the second transmitter 110 can be made different from each other without receiving communication information from each other. This reduces interference between transmitters, enabling each transmitter to transmit power efficiently, and improves the power transmission performance of the wireless power supply system.

[0073] The first transmitter 100 and the second transmitter 110 are equipped with a communication means for communicating with each other, and the first transmitter 100 or the second transmitter 110 may control the center frequency of the power supply wave of the first transmitter 100 to be different from the center frequency of the power supply wave of the second transmitter 110 based on communication information received via the communication means. Specifically, the first transmitter 100 may obtain information regarding the frequency of the power supply radio wave transmitted by the second transmitter 110 by wireless or wired communication, and control the frequency of the power supply radio wave transmitted by the first transmitter 100 to be different from the frequency of the power supply radio wave transmitted by the second transmitter 110. In addition, the first transmitter 100 may control the frequency of the power supply radio wave transmitted by the first transmitter 100 to be different from the frequency of the power supply radio wave transmitted by the second transmitter 110, based on the information regarding the frequency of the power supply radio wave transmitted by the second transmitter 110, obtained via the control device C10.

[0074] In the case where the receiver 200 is installed in a moving object, the control device C10 may be configured to execute the power supply control according to the present disclosure when the receiver 200 enters the power supply space. Specifically, when the receiver 200 newly enters the space, the power supply control according to the present disclosure may be executed for a predetermined period, and the power supply control according to the present disclosure may not be executed after the predetermined period has elapsed. This allows stable power supply even when the position of the receiver 200 is not determined within the power supply space. In addition, if the power supply radio wave can be transmitted so that power can be stably supplied to the position of the receiver 200 after the predetermined period has elapsed, the control according to the present disclosure may not be executed.

[0075] The difference in frequency of the radio waves transmitted by the first transmitter 100 and the second transmitter 110 may be changed according to the distance between the first transmitter 100 and the second transmitter 110. For example, the frequencies of the radio waves of the first transmitter 100 and the second transmitter 110 may be controlled to be different depending on the positions in the power supply space where the first transmitter 100 and the second transmitter 110 are installed so that power can be stably supplied to the entire power supply space. For example, the greater the distance between the first transmitter 100 and the second transmitter 110, the greater the difference in the frequencies of the power supply waves between the first transmitter 100 and the second transmitter 110. For example, the greater the distance between the first transmitter 100 and the second transmitter 110, the smaller the difference in the frequencies of the power supply waves between the first transmitter 100 and the second transmitter 110.

[0076] Alternatively, the difference in frequency of the radio waves transmitted by the first transmitter 100 and the second transmitter 110 may be changed according to the output between the first transmitter 100 and the second transmitter 110. For example, the frequencies of the radio waves of the first transmitter 100 and the second transmitter 110 may be controlled to be different depending on the output value, the difference in the output values, the ratio of the output values, etc. of the power supplying waves of the first transmitter 100 and the second transmitter 110 so that power can be supplied stably to the entire power supplying space. For example, the greater the difference in output value of the power supply radio waves between the first transmitter 100 and the second transmitter 110, the greater the difference may be made between the frequencies of the power supply radio waves between the first transmitter 100 and the second transmitter 110. For example, the smaller the difference in output value of the power supply radio waves between the first transmitter 100 and the second transmitter 110, the smaller the difference may be made between the frequencies of the power supply radio waves between the first transmitter 100 and the second transmitter 110.

[0077] In the present disclosure, the first transmitter 100 and the second transmitter 110 have been described as examples of transmitting devices housed in separate housings. The first transmitter 100 and the second transmitter 110 may be configured as antenna elements of an array antenna consisting of multiple antenna elements. Specifically, the first antenna element and the second antenna element included in the multiple antenna elements housed in one housing may be regarded as the first transmitter 100 and the second transmitter 110. In such a case, when one receiver receives power from one array antenna via radio waves, the receiver can receive a stable power supply from one array antenna regardless of the location in the space where the receiver is installed. Specifically, it is possible to prevent the occurrence of spatial locations (dead spots) where the receiver cannot receive sufficient power supply. This allows one array antenna to supply power more uniformly throughout the entire power supply space.

[0078] <Additional Notes> The matters described in the above embodiments will be supplemented below.

[0079] (Appendix 1) A wireless power supply system comprising a first transmitter, a second transmitter, and at least one receiver, wherein the first transmitter (100) and the second transmitter (110) are capable of wirelessly supplying power to the receiver (200) via power supply waves, the center frequency of the power supply waves of the first transmitter is different from the center frequency of the power supply waves of the second transmitter, and the power supply waves of the first transmitter and the second transmitter are radio waves that can be regarded as approximately continuous waves. When a single receiver receives power from multiple transmitters via radio waves, the receiver can receive a stable power supply from multiple transmitters regardless of the location in the space in which the receiver is installed. Specifically, it is possible to prevent the occurrence of spatial locations (dead spots) where the receiver cannot receive sufficient power. This allows the transmitter to supply power more uniformly throughout the entire power supply space.

[0080] (Appendix 2) 2. The wireless power feeding system according to claim 1, wherein the frequency of the power feeding radio wave of the first transmitter (100) is a radio wave belonging to the same channel as the frequency of the power feeding radio wave of the second transmitter (110). This makes it possible to suppress the occurrence of spatial positions (dead spots) where stable power supply cannot be performed within the power supply space while supplying sufficient power to the receiver in the first transmitter and the second transmitter that transmit power supply radio waves belonging to a channel of the same radio wave frequency band. This makes it possible for the transmitters to supply power more uniformly throughout the entire power supply space while the multiple transmitters supply power to the receiver by power supply radio waves of the same channel frequency band.

[0081] (Appendix 3) A wireless power supply system as described in Appendix 1, wherein the first transmitter (100) and the second transmitter (110) are capable of wirelessly communicating information with the receiver (200) via communication radio waves, and the power supply radio waves of the first transmitter and the second transmitter are unmodulated radio waves without a modulated signal and without information. This improves the efficiency of power transmission and makes it possible to prevent unnecessary information from being included in the power transmission radio waves.

[0082] (Appendix 4) A wireless power supply system as described in Appendix 1, wherein the center frequency f1 [Hz] of the power supply radio wave of the first transmitter is equal to or less than f2 × (1 + 1000 / 1,000,000) [Hz] and equal to or greater than f2 × (1 - 1000 / 1,000,000) [Hz], where f2 [Hz] is the center frequency of the power supply radio wave of the second transmitter. When one receiver receives power from multiple transmitters via radio waves, the receiver can receive stable power from the multiple transmitters regardless of the location in the space in which the receiver is installed. Specifically, the occurrence of dead spots can be particularly suppressed.

[0083] (Appendix 5) A wireless power supply system as described in Appendix 4, wherein the center frequency f1 [Hz] of the power supply radio wave of the first transmitter is equal to or greater than f2 × (1 + 0.001 / 1,000,000) [Hz], or equal to or less than f2 × (1 - 0.001 / 1,000,000) [Hz], where f2 [Hz] is the center frequency of the power supply radio wave of the second transmitter. When one receiver receives power supply from multiple transmitters via radio waves, the receiver can receive a stable supply of power from the multiple transmitters regardless of the location in the space in which the receiver is installed.

[0084] (Appendix 6) A wireless power supply system as described in Appendix 1, wherein the capacitances of the capacitors connected to the output terminals of the first transmitter and the second transmitter are different from each other, such that the center frequency of the power supply radio wave of the first transmitter is different from the center frequency of the power supply radio wave of the second transmitter. This allows the first transmitter and the second transmitter to have different center frequencies, making it possible to realize a wireless power supply system that can stably supply power from multiple transmitters to one receiver regardless of the location of the receiver in the space where it is installed.

[0085] (Appendix 7) A wireless power supply system as described in Appendix 1, wherein the center frequencies of the first transmitter and the second transmitter are controlled to be different from each other based on at least one or more of a temperature control means for controlling the temperature of the first transmitter and the second transmitter, a power supply voltage control means for controlling the power supply voltage of the first transmitter and the second transmitter, and a power supply current control means for controlling the power supply current to the first transmitter and the second transmitter. It is possible to realize a wireless power supply system that can stably supply power from multiple transmitters to one receiver, regardless of the location in the space where the receiver is installed.

[0086] (Appendix 8) The wireless power supply system according to claim 1, further comprising a control device capable of controlling the first transmitter and the second transmitter, the control device controlling the first transmitter so that a center frequency of the power supply radio wave is different from a center frequency of the power supply radio wave of the second transmitter. It is possible to realize a wireless power supply system that can stably supply power from multiple transmitters to one receiver, regardless of the location in the space where the receiver is installed.

[0087] (Appendix 9) 2. A wireless power supply system as described in claim 1, wherein the first transmitter and the second transmitter have a communication means for communicating with each other, and the first transmitter or the second transmitter controls the center frequency of the power supply radio wave of the first transmitter to be different from the center frequency of the power supply radio wave of the second transmitter based on communication information received via the communication means. It is possible to realize a wireless power transfer system that can stably supply power from multiple transmitters to one receiver regardless of the location in the space where the receiver is installed. Interference between transmitters is reduced, and each transmitter can transmit power efficiently, improving the power transmission performance of the system.

[0088] (Appendix 10) 2. A wireless power supply system as described in claim 1, wherein the first transmitter or the second transmitter controls the center frequency of the power supply wave of the first transmitter to be different from the center frequency of the power supply wave of the second transmitter without receiving communication information from each other. It is possible to realize a wireless power supply system that can stably supply power from multiple transmitters to one receiver regardless of the location in the space where the receiver is installed. This reduces the complexity of the system, reduces interference between transmitters, and improves the efficiency of power transmission. In addition, since communication is not required, security risks can be reduced. [Explanation of symbols]

[0089] 1 WPT system, 300 first information processing device, 3001 memory unit, 3004 control unit, 3006 input device, 3008 output device, 400 second information processing device, 4001 memory unit, 4004 control unit, 4006 input device, 4008 output device, C10 control device, C101 memory unit, C104 control unit, C106 input device, C108 output device, 100 transmitter, 110 transmitter, 200 receiver

Claims

[Claim 1] In a wireless power supply system comprising a first transmitter, a second transmitter, and at least one receiver, The first transmitter and the second transmitter are capable of supplying power to the receiver wirelessly via power supply radio waves. The center frequency of the feed radio waves of the first transmitter is different from the center frequency of the feed radio waves of the second transmitter. The power supply radio waves of the first transmitter and the second transmitter are radio waves that can be considered as substantially continuous waves. Wireless power supply system.

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