Wireless power transmission system

Abstract

To provide a wireless power transmission system capable of suppressing a radio wave exposed to objects such as people and animals.SOLUTION: A wireless power transmission system includes: a power transmission part for transmitting a radio wave for power supply; a water section apparatus including a power reception part for receiving the radio wave from the power transmission part; and a detection part for detecting whether an object exists around the water section apparatus. When a second range in which the detection part can detect the object is wider than a first range in which the power transmission part can transmit the radio wave, and the detection part detects the object, the power transmission part reduces output for transmitting the radio wave.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] Aspects of the present invention relate generally to wireless power transmission systems. [Background technology]

[0002] 2. Description of the Related Art Wireless power transmission systems capable of wirelessly supplying power to a plurality of devices are known. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2023-76909 A Summary of the Invention [Problem to be solved by the invention]

[0004] It is preferable that such a wireless power transmission system exposes humans, animals, and other living things to minimal radio waves.

[0005] An aspect of the present invention has been made based on the recognition of the above problem, and aims to provide a wireless power transmission system that can reduce radio waves to which objects such as people and animals are exposed. [Means for solving the problem]

[0006] A first invention is a wireless power transmission system comprising a power transmission unit that transmits radio waves for supplying power, a plumbing device including a power receiving unit that receives the radio waves from the power transmission unit, and a detection unit that detects whether or not an object is present around the plumbing device, wherein a second range in which the detection unit can detect the object is wider than a first range in which the power transmission unit can transmit the radio waves, and when the detection unit detects the object, the power transmission unit reduces the output power of transmitting the radio waves.

[0007] In this wireless power transmission system, the second range in which the detection unit can detect the target object is wider than the first range in which the power transmission unit can transmit radio waves. Therefore, when the detection unit detects the target object, the output of the radio waves from the power transmission unit can be reduced before the target object is exposed to the radio waves.

[0008] A second invention is a wireless power transmission system according to the first invention, characterized in that the detection units are multiple, and the second range is defined by a range in which the target object can be detected by the multiple detection units.

[0009] According to this wireless power transmission system, the second range is formed by a plurality of detection units, so that a wide detection range for the target object can be ensured.

[0010] A third invention is a wireless power transmission system according to the first invention, characterized in that a directional angle at which the detection unit detects the object is wider than a directional angle of radio waves at which the power transmission unit transmits the radio waves.

[0011] This wireless power transmission system can reduce the number of detectors installed. For example, if the detection unit has an omnidirectional (360°) beam angle, the detection unit can detect the target object no matter from which direction it approaches the plumbing equipment.

[0012] A fourth invention is the wireless power transmission system according to the first invention, characterized in that the detection unit detects the target object by a radio wave method.

[0013] According to this wireless power transmission system, the second range for detecting an object can be ensured as wide as possible even if an obstacle is present.

[0014] A fifth invention is a wireless power transmission system according to the fourth invention, characterized in that the frequency of the radio waves transmitted by the detection unit is in the same frequency band as the frequency of the radio waves transmitted by the power transmission unit.

[0015] According to this wireless power transmission system, the radio waves transmitted by the power transmission unit and the radio waves used by the detection unit to detect an object are in the same frequency band, so that the function of transmitting radio waves from the power transmission unit and the function of detecting an object by the detection unit can be realized by the same device (antenna).

[0016] A sixth invention is the wireless power transmission system according to the fourth invention, characterized in that the frequency of the radio waves transmitted by the detection unit is lower than the frequency of the radio waves transmitted by the power transmission unit.

[0017] Radio waves have the property that lower frequencies tend to diffract or penetrate obstacles more easily. Therefore, lower frequency radio waves can reach farther distances than higher frequency radio waves. This allows the wireless power transmission system to have a wider second range than the first range.

[0018] A seventh invention is a wireless power transmission system according to the fourth invention, characterized in that the power transmission unit reduces the output of the radio waves while determining whether or not the target object is present.

[0019] According to this wireless power transmission system, it is possible to avoid interference between the radio waves output by the power transmission unit and the radio waves used by the detection unit to detect an object. As a result, it is possible to improve the detection accuracy of the object by the detection unit. In addition, since the output (intensity) of the power transmission unit is reduced until the detection unit determines whether or not an object is present, it is possible to prevent the object from being exposed to the radio waves.

[0020] An eighth invention is a wireless power transmission system according to the first invention, characterized in that after the detection unit detects the target object and the power transmission unit reduces the output of the radio waves, the power transmission unit restores the reduced output of the radio waves after a predetermined period of time has passed since the detection unit detected the target object.

[0021] When the target object is located near the boundary of the second range, there is a risk that the output of the radio waves transmitted from the power transmission unit will be frequently switched. With this wireless power transmission system, the output of the radio waves from the power transmission unit can be restored after it is confirmed that the target object is no longer located within the second range. Effect of the Invention

[0022] According to an aspect of the present invention, a wireless power transmission system is provided that can reduce radio wave exposure to living beings such as humans and animals. [Brief description of the drawings]

[0023] [Figure 1] 1 is a diagram showing a toilet space in which a plumbing system according to a first embodiment is installed. [Diagram 2] A cross-sectional view showing a hand washing basin, which is one of the plumbing devices installed in the toilet space in Figure 1. [Diagram 3] FIG. 2 is a perspective view showing a toilet bowl, which is one of the plumbing devices installed in the toilet space in FIG. 1. [Figure 4] FIG. 2 is a perspective view showing a urinal, which is one of the plumbing devices installed in the toilet space in FIG. 1. [Diagram 5] 1 is a block diagram showing an overview of wireless power supply and object detection in a plumbing device included in a plumbing system according to a first embodiment. [Figure 6] FIG. 2 is an explanatory diagram illustrating a power transmission area and a detection area of ​​the plumbing system according to the first embodiment. [Figure 7] 4 is a diagram showing an example of a first range in which a power transmitting unit of the plumbing system according to the first embodiment transmits a first radio wave. FIG. [Figure 8] 4 is a diagram showing an example of the ranges of first radio waves and second radio waves of the plumbing system according to the first embodiment. FIG. [Figure 9] 4 is a flowchart showing an example of control processing executed by a power transmission unit 201 and a detection unit 202 of the plumbing system 1. [Figure 10] 13 is a block diagram showing an overview of wireless power supply and object detection in a plumbing device included in a plumbing system according to a second embodiment. FIG. [Figure 11] FIG. 11 is an explanatory diagram illustrating a second range of the detection unit of the plumbing system according to the second embodiment. [Figure 12] FIG. 13 is an explanatory diagram illustrating a second range of the detection unit of the plumbing system according to the third embodiment. [Figure 13] FIG. 13 is an explanatory diagram showing a modified example in which the power transmitting unit reduces the output of radio waves. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The drawings are schematic or conceptual, and the relationship between the thickness and width of each part, the size ratio between parts, etc. are not necessarily the same as those in reality. Even when the same part is shown, the dimensions and ratios of each part may be different depending on the drawing. In this specification and each drawing, elements similar to those described above with reference to the previous drawings are given the same reference numerals and detailed descriptions thereof will be omitted as appropriate.

[0025] (First embodiment) First, with reference to FIG. 1, a toilet space TR in which a plumbing system 1 to which a wireless power transmission system according to a first embodiment is applied is described. FIG. 1 is a diagram showing a toilet space in which a plumbing system according to a first embodiment is installed.

[0026] As shown in Fig. 1, for example, a public toilet space TR is provided with a hand washing basin 11, a toilet bowl 12, and a urinal 13, which are plumbing equipment 10 provided in a plumbing system 1. A plurality of hand washing basins 11, toilet bowls 12, and urinals 13 are each installed at predetermined locations in the toilet space TR.

[0027] Further, a power control unit 20 is installed in the toilet space TR. The power control unit 20 includes a power transmission unit 201, which will be described later, and a detection unit 202. The power transmission unit 201 wirelessly supplies power to a power receiving unit 31, which will be described later, provided in each of the plumbing devices 10 (11, 12, 13), and supplies power to a load 35 (see FIG. 5). The detection unit 202 detects an object (such as a human body or an animal).

[0028] The power control unit 20 is installed, for example, on the ceiling C of the toilet space TR. In the present embodiment, the power control unit 20 includes the power transmission unit 201 and the detection unit 202, but the power transmission unit 201 and the detection unit 202 may be provided separately in the toilet space TR. That is, the power transmission unit 201 and the detection unit 202 may be provided in one casing or in separate casings.

[0029] Next, an example of the plumbing device 10 included in the plumbing system 1 according to the first embodiment will be described with reference to FIGS. FIG. 2 is a cross-sectional view showing a hand washing basin, which is one of the plumbing devices installed in the toilet space in FIG. FIG. 3 is a perspective view showing a toilet bowl, which is one of the plumbing devices installed in the toilet space in FIG. FIG. 4 is a perspective view showing a urinal, which is one of the plumbing devices installed in the toilet space in FIG.

[0030] 2, a hand washing basin 11, which is one of the plumbing devices 10, detects a human body (hand) and automatically discharges and stops water. The hand washing basin 11 discharges water into a wash basin B1 attached to a washstand.

[0031] The washbasin B1 is provided on the washbasin counter 50. The washbasin counter 50 is provided with a water outlet 11a constituting a spout for discharging water onto the bowl surface BS1 of the washbasin B1. The water outlet 11a has a water outlet 11aa for discharging water, and is provided so that the water discharged from the water outlet 11aa is discharged onto the bowl surface BS1 of the washbasin B1.

[0032] Water discharged from the water outlet 11aa is supplied from a water supply passage 11c. The water supply passage 11c guides water supplied from a water supply source such as a water pipe to the water outlet 11aa. A drain passage 11d is connected to the washbasin B1. The drain passage 11d drains the water discharged from the water outlet 11aa to the bowl surface BS1 of the washbasin B1.

[0033] The hand washing basin 11 also includes a power receiving unit 31, a control unit 34, a sensor unit 351, and a solenoid valve 352. The control unit 34 detects the position and movement of an object, for example, based on a detection signal. The control unit 34 controls the opening and closing operation of the solenoid valve 352 based on the detection result. The control unit 34 also outputs a control signal to the sensor unit 351 to control the sensing operation of the sensor unit 351. Details of the power receiving unit 31 will be described later.

[0034] The control unit 34 is capable of controlling each part through electronic control, and includes a processing unit (not shown) having a CPU (Central Processing Unit) etc., as well as a memory unit consisting of a hard disk, ROM (Read Only Memory), RAM (Random Access Memory) etc., in which various programs and necessary data are stored.

[0035] The sensor unit 351 is provided near the water outlet 11aa of the water discharge unit 11a, and is arranged to transmit an optical signal toward the user's side of the washbasin (the left side in FIG. 2). The sensor unit 351 detects an object such as the user's hand approaching the water outlet 11aa using a built-in sensor. In this case, the destination of the water from the water outlet 11aa is included in the detection area of ​​the sensor unit 351. The sensor unit 351 detects the position and movement of the hand, for example, by receiving a reflected signal reflected from the hand that has received the transmitted optical signal.

[0036] The sensor of the sensor unit 351 is, for example, an optical sensor that uses an infrared light signal. The optical signal transmitted from the sensor may be, for example, visible light. Note that "infrared light" is, for example, light with a wavelength of 0.7 μm or more and 1000 μm or less. The sensor may be, for example, an ultrasonic sensor or a microwave sensor.

[0037] Sensor unit 351 inputs a detection signal indicating the result of the hand detection to control unit 34. Control unit 34 detects the presence or absence of a hand based on the detection signal input from sensor unit 351.

[0038] The solenoid valve 352 is provided in the water supply passage 11c and opens and closes the water supply passage 11c. When the solenoid valve 352 is opened, water supplied from the water supply passage 11c is discharged from the water outlet 11aa, and when the solenoid valve 352 is closed, the discharge of the water supplied from the water supply passage 11c from the water outlet 11aa is stopped.

[0039] The solenoid valve 352 is connected to the control unit 34, and the control unit 34 drives the solenoid valve 352 to control the opening and closing operation of the solenoid valve 352. The solenoid valve 352 is electrically controlled by a control signal from the control unit 34 to open and close the water supply passage 11c. In this way, the solenoid valve 352 functions as a water supply valve that opens and closes the water supply passage 11c for water discharged from the water outlet 11aa.

[0040] It should be noted that solenoid valve 352 is a self-holding solenoid valve (latch type solenoid valve) also known as a latching solenoid valve; it switches from a closed state to an open state when current is passed through the solenoid coil in one direction, and then maintains the open state even if current is cut off to the solenoid coil. It switches from the open state to a closed state when current is passed through the solenoid coil in the other direction, and then maintains the closed state even if current is cut off to the solenoid coil.

[0041] Power is supplied to the hand washing device 11 by a first radio wave transmitted from the power transmitting unit 201. Wireless power supply by the first radio wave will be described later.

[0042] As shown in Fig. 3, toilet 12, which is one of plumbing devices 10, has a concave bowl portion B2 and a water outlet (not shown) that discharges flushing water onto the bowl surface BS2 of bowl portion B2. The toilet 12 flushes away waste excreted into bowl portion B2 by discharging flushing water supplied via water supply passage 12c from the water outlet into bowl portion B2. In the example shown, toilet 12 is a Western-style toilet.

[0043] The toilet 12 comprises a power receiving unit 31, a control unit 34, a sensor unit 351, and a solenoid valve 352. The control unit 34 opens the solenoid valve 352, for example, by detecting a hand held over the sensor unit 351. Details of the power receiving unit 31 will be described later. Note that in the toilet 12, parts that are substantially the same in function and configuration as the above-mentioned hand washing basin 11 are given the same reference numerals and their explanation will be omitted.

[0044] 4, the urinal 13, which is one of the plumbing devices 10, includes a concave bowl portion B3 and a water outlet (not shown) that discharges flushing water onto a bowl surface BS3 of the bowl portion B3. The urinal 13 flushes the bowl surface BS3 of the bowl portion B3 by discharging flushing water supplied via a water supply passage 13c from the water outlet into the bowl portion B3.

[0045] As shown in Fig. 4, the urinal 13 includes a power receiving unit 31, a control unit 34, a sensor unit 351, and a solenoid valve 352. For example, when a user standing in front of the sensor unit 351 moves out of the detection range of the sensor unit 351, the control unit 34 opens the solenoid valve 352. Details of the power receiving unit 31 will be described later. Note that in the urinal 13, components that are substantially the same in function and configuration as the hand washing basin 11 and toilet 12 described above are given the same reference numerals, and their description will be omitted.

[0046] The plumbing equipment 10 may be, for example, a remote controller for operating the equipment in the toilet space TR, in addition to the hand washing basin 11, the toilet bowl 12, and the urinal 13 installed in the toilet space TR.

[0047] Next, an overview of wireless power supply and object detection in the plumbing device 10 included in the plumbing system 1 according to the first embodiment will be described with reference to FIG. FIG. 5 is a block diagram showing an overview of wireless power supply and object detection in a plumbing device included in the plumbing system according to the first embodiment.

[0048] As shown in FIG. 5, power is supplied to a power transmitting unit 201 that transmits a first radio wave toward the plumbing device 10 and a detection unit 202 that detects an object via an AC power source 23 and an AC / DC converter 24.

[0049] The power transmitting unit 201 transmits a first radio wave. The power transmitting unit 201 includes, for example, a transmitting IC 21 and a power transmitting antenna 22. The transmitting IC 21 determines the transmission direction of the first radio wave. The power transmitting antenna 22 transmits the first radio wave in the transmission direction determined by the transmitting IC 21. For example, the power transmitting antenna 22 has a plurality of antennas, and an antenna corresponding to the direction in which the first radio wave is transmitted is used. A first range A11 in which the first radio wave can be transmitted will be described later. The power transmitting unit 201 may include one power transmitting antenna capable of changing the transmission direction of a microwave signal.

[0050] The power transmitting unit 201 is, for example, a radio wave type wireless transmitter such as a transmitter, and transmits a signal as a radio wave (first radio wave). The frequency of the first radio wave is a radio wave in the 920 MHz band. In this embodiment, the frequency of the first radio wave is, for example, 930 MHz. Note that the frequency of the first radio wave is not limited to this. For example, the first radio wave may be a microwave. The microwave is a radio wave with a wavelength of 300 MHz or more and 300 GHz or less. Furthermore, the first radio wave may be a radio wave in the 2.4 GHz band or 5.0 GHz band.

[0051] The detection unit 202 detects objects such as people and animals present around the bathroom equipment 10. Here, the surroundings of the bathroom equipment 10 are not limited to the toilet space TR but also include corridors, passageways, upper floors, lower floors, and the like that are located around the toilet space TR. In other words, even if there is an obstacle such as a wall or floor F between the object and the bathroom equipment 10, the object is included in the surroundings of the bathroom equipment 10. The surroundings of the bathroom equipment 10 will be described in the second range A2 described later.

[0052] The detection unit 202 includes, for example, a detection IC 25 and a transmission / reception antenna 26. The detection IC 25 detects an object based on the second radio wave transmitted and received from the transmission / reception antenna 26. The transmission / reception antenna 26 transmits the second radio wave in all directions, for example, up / down, left / right, front / rear, and receives reflected waves of the transmitted second radio wave.

[0053] In this embodiment, the radio wave method of the detection unit 202 is, for example, sensing by WiFi. An object is detected by sensing by WiFi. For example, the sensing by WiFi senses a first path of the transmitted second radio wave and a second path along which the second radio wave is reflected and returned, and detects whether the first path and the second path have been changed from the previous first path and the second path. The detection IC 25 detects whether an object exists within a second range A2 described later by sensing by WiFi.

[0054] The frequency of the second radio wave is in the 920 MHz band. In this embodiment, the frequency of the second radio wave is, for example, 902 MHz. In this way, the frequency of the second radio wave is in the same band as the frequency of the first radio wave, but is lower than the frequency of the first radio wave. If the frequency of the second radio wave is lower than the frequency of the first radio wave, the frequencies of the first radio wave and the second radio wave may be set arbitrarily within the 920 MHz band. Note that the detection unit 202 may be, for example, an infrared sensor, a light sensor, an ultrasonic sensor, a pyroelectric sensor, or an electrostatic sensor as long as it can detect the target object.

[0055] Moreover, the frequency of the second radio wave may be in the 2.4 GHz band or the 5.0 GHz band. Combinations of the first radio wave and the second radio wave will be specifically described. For example, in the 2.4 GHz band, the first radio wave may be 2.484 GHz and the second radio wave may be 2.412 GHz. For example, in the 5.0 GHz band, the first radio wave may be 5.764 GHz and the second radio wave may be 5.180 GHz. The frequency bands of the first radio wave and the second radio wave may be different. For example, the first radio wave may be 2.484 GHz in the 2.4 GHz band and the second radio wave may be 902 MHz in the 920 MHz band. For example, the first radio wave may be 5.764 GHz in the 5.0 GHz band and the second radio wave may be 2.412 GHz in the 2.4 GHz band. For example, the first radio wave may be 5.764 GHz in the 5.0 GHz band and the second radio wave may be 902 MHz in the 920 MHz band.

[0056] The plumbing device 10 includes, for example, a power receiving unit 31, a power storage unit 340, a diode 341, a voltage conversion unit 342, and a load 35. The power receiving unit 31 receives a first radio wave transmitted from the power transmitting unit 201. The power receiving unit 31 converts the received first radio wave into electric power.

[0057] The power receiving unit 31 is configured, for example, by a rectifying antenna. A rectenna is an antenna in which a receiving antenna and a rectifying circuit are integrated. The power receiving unit 31 includes, for example, a power receiving antenna, an input low-pass filter, a rectifying circuit, and an output low-pass filter. The power receiving antenna, the input low-pass filter, the rectifying circuit, and the output low-pass filter are electrically connected in this order.

[0058] The receiving antenna receives the first radio wave. For example, an array antenna is used as the receiving antenna. The input low-pass filter is composed of a low-pass filter circuit, and suppresses harmonics generated when the first radio wave is rectified from being re-radiated from the receiving antenna into space. The rectifier circuit is composed of a bridge rectifier circuit or the like. The output low-pass filter is composed of a low-pass filter circuit, and passes only DC power toward the load.

[0059] The power storage unit 340 stores the power converted by the power receiving unit 31. The diode 341 prevents a current from flowing back from the power storage unit 340 to the power receiving unit 31. The voltage conversion unit 342 converts the power supplied from the power receiving unit 31 or the power storage unit 340 into power (voltage) capable of driving the load 35.

[0060] The load 35 is a sensor unit 351 and a solenoid valve 352 provided in the plumbing device 10, and is driven by power generated by the power converted by the power receiving unit 31. The plumbing device 10 drives the load 35 (the sensor unit 351 and the solenoid valve 352) by power obtained by converting the first radio wave transmitted from the power transmitting unit 201.

[0061] FIG. 6 is an explanatory diagram illustrating the power transmission area and the detection area of ​​the plumbing system according to the first embodiment.

[0062] 6, range A1 (power transmission area) is a range of wireless power supply in which one antenna of the power transmitting antenna 22 can transmit the first radio wave. An effective power transmission distance D1 of range A1 is a distance that at least reaches the power receiving unit 31 of the plumbing device 10. Range A1 is set so as to cover, for example, the toilet space TR. Range A1 faces downward (toilet space TR) from the power transmitting unit 201 provided on the ceiling C, for example.

[0063] The first directivity angle R1 is, for example, 30°. Note that the directivity angle is an angle that is realized when the transmission power of the first radio wave is about half of a specified value, for example, 3 dB lower than the specified value, when the first radio wave is transmitted in a predetermined direction from the power transmitting antenna 22.

[0064] The power transmitting unit 201 improves the strength of the first radio wave by making the first radio wave directivity in the transmission direction. Since the first directivity angle R1 is set to 30°, the power transmitting unit 201 can transmit the first radio wave in all directions (360° directions in a plan view) in the toilet space TR by the transmitting IC 21 individually activating the multiple antennas of the power transmitting antenna 22 12 times.

[0065] FIG. 7 is a diagram illustrating an example of a first range in which the power transmitting unit of the plumbing system according to the first embodiment transmits a first radio wave. FIG. 8 is a diagram illustrating an example of the ranges of the first radio waves and the second radio waves of the plumbing system according to the first embodiment. By operating the power transmitting antenna 22 12 times, the power transmitting unit 201 can sequentially transmit the first radio wave in all directions (360° directions) in a planar view, that is, in a first range A11, as shown in Fig. 7. Note that the first radio wave may not have directionality, that is, the power transmitting antenna 22 may not have directionality, and the first radio wave may be transmitted simultaneously in all directions (360°) in a planar view.

[0066] As shown in Figs. 6 to 8, the second range A2 is a range in which the detection unit 202 can detect an object by the second radio wave. The second range A2 is set so as to cover a space larger than the range A1 (power transmission area). More specifically, for example, it covers a space larger than the toilet space TR. The communication distance D2 of the second range A2 is longer than the effective power transmission distance D1 of the first range A11. Radio waves have a property that they can easily diffract or penetrate obstacles and the like when their frequency is lower. Therefore, the frequency of the second radio wave is set lower than the frequency of the first radio wave. The second directivity angle R2 of the detection unit 202 is 360° in all directions, i.e., in a planar view and a side view, in other words. The detection unit 202 can detect an object present within a range of the distance D2 from the detection unit 202 (the power control unit 20).

[0067] 8 is an explanatory diagram of the first range and the second range when the toilet space TR is viewed from the side. The first directivity angle R1 is, for example, 120° so that the first radio wave reaches the power receiving unit 31 of the plumbing device 10. The second range A2 is set so as to cover a space larger than the first range A11 (power transmission area). More specifically, the second range A2 covers a space larger than the toilet space TR, for example, and includes the space above the ceiling C and the space below the floor F of the toilet space TR.

[0068] The second range A2 does not need to be 360° in plan view and side view, but may be set within a range in which the first radio waves transmitted from the power transmission unit 201 are not exposed to an object. For example, the second range A2 may be set to a range only below the detection unit 202 installed on the ceiling C (for example, a range within 360° in plan view) if there is no possibility that the first radio waves will be exposed to an object on a floor above the floor on which the toilet space TR is located.

[0069] Next, output control for reducing the output (intensity) of the first radio wave outputted by the power transmitting unit 201 of the plumbing system 1 will be described. FIG. 9 is a flowchart showing an example of a control process executed by the power transmitting unit 201 and the detecting unit 202 of the plumbing system 1. As shown in FIG.

[0070] 9, the detection unit 202 transmits and receives a second radio wave (ST101). In this way, the detection unit 202 can acquire the first path and the second path of the second radio wave transmitted from the transmission / reception antenna 26.

[0071] Next, the detection unit 202 determines whether or not an object exists within the second range A2 (ST102). The detection unit 202 determines whether or not an object exists within the second range A2 based on, for example, whether or not there is a path difference between the previous first path and second path and the current first path and second path. When the detection unit 202 determines that an object has not been detected (ST102: NO), the process returns and the detection of the object continues. Note that the power transmission unit 201 continues to output the first radio wave at the preset first strength.

[0072] If the detection unit 202 determines that the target object is present (ST102: YES), the power transmitting unit 201 reduces the intensity of the first radio wave to the second intensity (ST103). More specifically, the detection IC 25 of the detection unit 202 transmits information indicating the presence of the target object to the transmission IC 21 of the power transmitting unit 201. Upon receiving this information, the transmission IC 21 reduces the intensity of the first radio wave transmitted from the power transmitting antenna 22 from the first intensity to the second intensity. This reduces the intensity of the first radio wave transmitted within the first range A11. Note that the change in intensity of the first radio wave from the first intensity to the second intensity by the power transmitting unit 201 may be achieved by stopping the output of the first radio wave.

[0073] Next, the detection unit 202 determines whether or not an object is being detected (ST104). When the detection unit 202 determines that an object is being detected (ST104: YES), the process returns to step ST104. That is, the determination of whether or not an object is being detected is repeated. While this determination is repeated, in other words, when an object exists within the second range A2, the state in which the intensity of the first radio wave is reduced (second intensity) is continued.

[0074] If it is determined that the detection unit 202 is not detecting an object (ST104: NO), the power transmission unit 201 determines whether or not a predetermined time has elapsed (ST105). Here, the predetermined time may be, for example, about several minutes (for example, 1 to 3 minutes) after the object is no longer detected. If it is determined that the predetermined time has not elapsed (ST105: NO), the process returns to step ST104. That is, the process of determining whether or not an object is present within the second range A2 is continued.

[0075] When it is determined that the predetermined time has elapsed (ST105: YES), the power transmitting unit 201 increases the intensity of the first radio wave and returns it to the original intensity (first intensity) (ST106). More specifically, the transmission IC 21 of the power transmitting unit 201 returns the intensity of the first radio wave transmitted from the power transmitting antenna 22 from the second intensity to the first intensity. This makes it possible to return the intensity of the first radio wave to the original intensity when the target object is definitely no longer present within the second range A2.

[0076] As described above, the plumbing system 1 includes the power transmitting unit 201, a plurality of plumbing devices 10, and the detection unit 202. The second range A2 in which the detection unit 202 can detect an object is wider than the first range A11 in which the power transmitting unit 201 can transmit the first radio wave. Furthermore, when the detection unit detects an object, the power transmitting unit 201 can reduce the output for transmitting the first radio wave.

[0077] According to this plumbing system 1, the second range in which the detection unit 202 can detect an object is wider than the first range A11 in which the power transmission unit 201 can transmit the first radio waves. Therefore, when the detection unit 202 detects an object, the output of the first radio waves from the power transmission unit 201 can be reliably reduced before the object is exposed to the first radio waves. The power transmission unit 201 can reduce the intensity of the first radio waves before the object approaches the plumbing device 10.

[0078] The detection unit 202 detects the object by a radio wave method, for example, WiFi sensing. According to this bathroom system 1, even if an obstacle such as a wall exists within the distance D2 of the second range A2, the second radio wave for detecting the object can reach outside the obstacle.

[0079] The frequency of the second radio wave transmitted by the detection unit 202 is in the same frequency band as the frequency of the first radio wave transmitted by the power transmission unit 201 (for example, any one of the 920 MHz band, the 2.4 GHz band, and the 5.0 GHz band).

[0080] According to this plumbing system 1, the first radio wave transmitted by the power transmitting unit 201 and the second radio wave for detecting an object by the detection unit 202 are in the same frequency band, so that a common device (antenna) can be used. Therefore, the same device can be used for both the function of transmitting the first radio wave by the power transmitting unit 201 and the function of detecting an object by the detection unit 202.

[0081] The frequency of the second radio wave transmitted by the detection unit 202 is lower than the frequency of the radio wave transmitted by the power transmission unit 201 .

[0082] A radio wave with a lower frequency can reach a longer distance than a radio wave with a lower frequency. Radio waves with a lower frequency have the property of being more easily diffracted or transmitted through obstacles. For this reason, the plumbing system 1 can make the second range A2 wider than the first range A11.

[0083] The first radio wave and the second radio wave do not have to be in the same frequency band, and for example, the first radio wave may be in the 2.4 GHz band and the second radio wave may be in the 920 MHz band. The first radio wave may be in the 5.0 GHz band and the second radio wave may be in the 2.4 GHz band. The first radio wave may be in the 5.0 GHz band and the second radio wave may be in the 920 MHz band. The greater the frequency difference, the easier it is to make the second range A2 wider than the first range A11.

[0084] After the detection unit 202 detects an object and the power transmission unit 201 reduces the output of the first radio wave, the power transmission unit 201 returns the reduced output of the first radio wave to its original level after a predetermined period of time has passed during which the detection unit 202 has not detected an object.

[0085] According to this bathroom system 1, the strength of the first radio waves output by the power transmission unit 201 can be restored once it is confirmed that the object is no longer within the second range A2, thereby improving safety by preventing the object from being exposed to the first radio waves.

[0086] Second embodiment The second embodiment differs from the first embodiment in that the configuration of the second range detected by the detection unit 202 included in the plumbing system 1 is changed. Note that the same components as those in the first embodiment are denoted by the same reference numerals, and detailed descriptions of these components are omitted.

[0087] FIG. 10 is a block diagram showing an overview of wireless power supply and object detection in a plumbing device included in a plumbing system according to the second embodiment. FIG. 11 is an explanatory diagram illustrating the second range of the detection unit of the plumbing system. FIG. 12 is an explanatory diagram illustrating the second range of the detection unit of the plumbing system according to the third embodiment.

[0088] 10, a first detection unit 202A, a second detection unit 202B, a third detection unit 202C, and a fourth detection unit 202D are provided instead of the detection unit 202. The first detection unit 202A, the second detection unit 202B, the third detection unit 202C, and the fourth detection unit 202D may be, for example, any one of an infrared sensor, a radio wave sensor, an optical sensor, an ultrasonic sensor, a pyroelectric sensor, and an electrostatic sensor.

[0089] In the second embodiment, a case where the first detection unit 202A, the second detection unit 202B, the third detection unit 202C, and the fourth detection unit 202D are infrared sensors will be described as an example. Note that, although a case where four detection units, the first detection unit 202A, the second detection unit 202B, the third detection unit 202C, and the fourth detection unit 202D, are provided will be described, the number of detection units may be any number as long as they are configured to detect an object in an area outside the first range A11.

[0090] The power control unit 20 also includes a receiving IC 27. The receiving IC 27 receives the detection results of the object from the first detection unit 202A, the second detection unit 202B, the third detection unit 202C, and the fourth detection unit 202D, and outputs the received detection results to the transmitting IC 21.

[0091] 11, the second range A2 is made up of four ranges A21 to A24. A first detection unit 202A, a second detection unit 202B, a third detection unit 202C, and a fourth detection unit 202D are provided in each of the four ranges A21 to A24, respectively, so that objects within the ranges A21 to A24 can be detected.

[0092] The first detection unit 202A, the second detection unit 202B, the third detection unit 202C, and the fourth detection unit 202D are each composed of a light emitting unit and a light receiving unit. The four ranges A21 to A24 are configured to surround the first range A11. In other words, the first range A11 is not included in the second range A2. This allows the first to fourth detection units 202A to 202D to detect an object approaching the first range A11. Since the first detection unit 202A, the second detection unit 202B, the third detection unit 202C, and the fourth detection unit 202D are infrared sensors, the second directivity angle R2 is approximately 0°.

[0093] In the plumbing system 1, the four ranges A21 to A24 (second range A2) in which the first detection unit 202A, the second detection unit 202B, the third detection unit 202C, and the fourth detection unit 202D can detect an object are wider than the first range A11 in which the power transmission unit 201 can transmit the first radio waves, so that when the detection unit 202 detects an object, the output of the first radio waves from the power transmission unit 201 can be reliably reduced before the object is exposed to the first radio waves.

[0094] In the plumbing system 1, the second range A2 is configured by a plurality of detection units, that is, the first detection unit 202A, the second detection unit 202B, the third detection unit 202C, and the fourth detection unit 202D. This makes it possible to ensure a wide range in which the second detection unit 202 detects an object.

[0095] Fig. 12 is an explanatory diagram illustrating the second range of the detection unit of the plumbing system according to the third embodiment. As in Fig. 11, the second range A2 is made up of four ranges A21 to A24. What differs from Fig. 11 is the second directivity angle R2. In Fig. 12, the first to fourth detection units 202A to 202D are, for example, sensing by the above-mentioned WiFi, and the directivity is, for example, omnidirectional (360°) in plan view and side view.

[0096] As shown in Figures 11 and 12, by configuring the detection of an object using multiple detection units 202A to 202D, the second range A2 can be configured without depending on the directivity or radio wave intensity of each of the detection units 202A to 202D, and a wider detection range for the object can be ensured.

[0097] FIG. 13 is an explanatory diagram showing a modified example in which the power transmitting unit reduces the output of radio waves. In the above-described first embodiment, an example has been described in which the output of radio waves transmitted by the power transmitting unit 201 is reduced when the detection unit 202 detects the presence of an object in the second range A2. Here, while the detection unit 202 is determining whether or not an object is present, it is unclear whether or not an object exists in the second range A2. Therefore, as shown in Fig. 13, the power transmitting unit 201 may reduce the output (intensity) of radio waves during such a period in which the presence of an object is unclear. The same applies to the second embodiment.

[0098] As shown in FIG. 13, at time t1, the detection unit 202 starts to determine whether or not an object exists within the second range A2. The power transmission unit 201 also reduces the intensity of the radio waves to be transmitted from the first intensity to the second intensity. At the next time t2, the detection unit 202 determines that an object does not exist within the second range A2, and ends the determination of the presence of the object. In this case, the power transmission unit 201 returns the intensity of the radio waves to be transmitted from the second intensity to the first intensity. The time from OFF to ON of the object determination is several seconds (for example, 1 second). The detection unit 202 performs the determination of whether or not an object exists within the second range A2 at intervals of, for example, 1 second.

[0099] Then, from time t3 to time t4, it is determined that an object is present within the second range A2. In such a case, the power transmitting unit 201 continues transmitting the radio waves at the lowered second intensity even after time t4 when the object determination is completed. Thereafter, when the detection unit 202 detects that an object is not present within the second range A2, the power transmitting unit 201 returns the output of the radio waves to be transmitted from the second intensity to the first intensity. This makes it possible to suppress exposure of radio waves to objects such as people and animals.

[0100] In the above embodiment, the first range A11 where the power transmitting unit 201 transmits radio waves is set to a 360° direction when multiple antennas are operated 12 times. However, the first range may be provided only in any direction. For example, the first range may be only the range A1 formed by the first directional angle R1 (for example, 30°) of one antenna of the power transmitting antenna 22. The directional angle at which the detection unit 202 detects the target object is set to be larger than the first directional angle R1. In this case, the directional direction of the detection unit 202 is set to the same direction as the directional direction of the power transmitting unit 201. This allows the second range of the detection unit 202 to be provided around the first range of the power transmitting unit 201. Even in such a case, the number of detection units 202 installed can be reduced to detect the target object.

[0101] Also, in the above-described embodiment, an example was described in which the output of radio waves transmitted from the power transmission unit 201 was reduced when the presence of an object was detected. However, for example, the power transmission unit 201 may recognize the position of the object and control the transmission direction of the radio waves. For example, if an object is present around the hand washing basin 11, the object is unlikely to be exposed to the radio waves outputted toward the toilet bowl 12 or urinal 13. In such a case, the power transmission unit 201 may only reduce the output of the radio waves transmitted toward the hand washing basin 11, and not reduce the output of the radio waves transmitted toward the toilet bowl 12 or urinal 13.

[0102] The embodiments include the following aspects. (Configuration 1) a power transmission unit that transmits radio waves for power supply; A plumbing device including a power receiving unit that receives the radio waves from the power transmitting unit; A detection unit that detects whether or not an object is present around the plumbing device; Equipped with a second range in which the detection unit can detect the object is wider than a first range in which the power transmission unit can transmit the radio waves; A wireless power transmission system, characterized in that, when the detection unit detects the target object, the power transmission unit reduces the output power for transmitting the radio waves. (Configuration 2) The detection unit includes a plurality of detection units, 2. The wireless power transmission system according to configuration 1, wherein the second range is configured by a range in which the target object can be detected by a plurality of the detection units. (Configuration 3) 3. The wireless power transmission system according to configuration 1 or 2, wherein a directivity angle at which the detection unit detects the object is wider than a directivity angle of radio waves transmitted by the power transmission unit. (Configuration 4) 4. The wireless power transmitting system according to any one of configurations 1 to 3, wherein the detection unit detects the target object by a radio wave method. (Configuration 5) 5. The wireless power transmitting system according to configuration 4, wherein the frequency of the radio waves transmitted by the detection unit is in the same frequency band as the frequency of the radio waves transmitted by the power transmission unit. (Configuration 6) 6. The wireless power transmitting system according to configuration 4 or 5, wherein the frequency of the radio waves transmitted by the detection unit is lower than the frequency of the radio waves transmitted by the power transmission unit. (Configuration 7) 7. The wireless power transmitting system according to any one of configurations 1 to 6, wherein the power transmitting section reduces an output of the radio waves while determining whether or not the object is present. (Configuration 8) The wireless power transmission system according to any one of configurations 1 to 7, characterized in that after the detection unit detects the target object and the power transmission unit reduces the output of the radio waves, the power transmission unit restores the reduced output of the radio waves after a predetermined period of time has passed since the detection unit detected the target object.

[0103] The above describes the embodiments of the present invention. However, the present invention is not limited to these descriptions. Regarding the above-mentioned embodiments, those in which a person skilled in the art makes appropriate design changes are also included in the scope of the present invention as long as they have the features of the present invention. For example, the shape, dimensions, material, arrangement, etc. of each element of the wireless power transmission system are not limited to those exemplified and can be appropriately changed. In addition, each element of each of the above-mentioned embodiments can be combined to the extent technically possible, and the combination of these is also included in the scope of the present invention as long as it includes the features of the present invention. [Explanation of symbols]

[0104] 1. Water supply system 10. Plumbing equipment 11 Hand wash basin 11a Water outlet 11aa Outlet 11c Water supply channel 11d Drainage channel 12 Toilet bowl 12c water supply channel 13 Urinal 13c Water supply channel 20 Power Control Unit 21 Transmission IC 22 Power transmission antenna 23 AC power supply 24 AC / DC converter 25 Detection IC 26 Transmitting and receiving antenna 27 Receiving IC 31 Power receiving section 34 Control section 35 Load 50 Washbasin counter 201 Power Transmission Division 202 Detection unit 202A First detection section 202B Second detection unit 202C 3rd detector 202D 4th detector 340 Power storage unit 341 Diode 342 Voltage conversion unit 351 Sensor section 352 Solenoid valve A1 range A11 1st range A2 2nd range A21, A22, A23, A24 range B1 washbasin B2, B3 Bowl section BS1, BS2, BS3 Bowl surface D1 Effective power transmission distance D2 Communication distance R1 1st directivity angle R2 2nd directivity angle TR Toilet space

Claims

1. a power transmission unit that transmits radio waves for power supply; A plumbing device including a power receiving unit that receives the radio waves from the power transmitting unit; A detection unit that detects whether or not an object is present around the plumbing device; Equipped with a second range in which the detection unit can detect the object is wider than a first range in which the power transmission unit can transmit the radio waves; A wireless power transmission system, characterized in that, when the detection unit detects the target object, the power transmission unit reduces the output power for transmitting the radio waves.

2. The detection unit includes a plurality of detection units, The wireless power transmission system according to claim 1 , wherein the second range is configured by a range in which the target object can be detected by a plurality of the detection units.

3. The wireless power transmission system according to claim 1 , wherein a directivity angle at which the detection unit detects the object is wider than a directivity angle of radio waves transmitted by the power transmission unit.

4. The wireless power transmission system according to claim 1 , wherein the detection unit detects the object by a radio wave method.

5. The wireless power transmission system according to claim 4 , wherein a frequency of the radio wave transmitted by the detection unit is in the same frequency band as a frequency of the radio wave transmitted by the power transmission unit.

6. The wireless power transmission system according to claim 4 , wherein the frequency of the radio waves transmitted by the detection unit is lower than the frequency of the radio waves transmitted by the power transmission unit.

7. The wireless power transmission system according to claim 4 , wherein the power transmission unit reduces an output of the radio waves while determining whether or not the object is present.

8. The wireless power transmission system according to claim 1, characterized in that after the detection unit detects the target object and the power transmission unit reduces the output of the radio waves, the power transmission unit returns the reduced output of the radio waves to its original state after a predetermined period of time has passed since the detection unit detected the target object.

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