Sensor system

Abstract

Provided are: a housing that wirelessly receives energy and supplies power to a device in a manner that prevents an increase of overall size while still ensuring favorable power reception efficiency; and a device having said housing. Provided is a housing 31 that constitutes the main body of a device 30 which is a sensor or actuator. Installed to the housing 31 is a power receiving device that mainly generates an electric field or magnetic field for wireless power supply. The power receiving device is at least one device selected from among a dipole antenna 21, a slot antenna 22, a monopole antenna, a chip antenna, and an inverted F antenna. The housing 31 has a size in three-dimensional space. An increase in the size of the housing 31 in three-dimensional space due to provision of the power receiving device is limited to, at maximum, substantially one axis direction (x-axis direction).

Description

Technical Field

[0001] [Related Application] This application claims the priority of Japanese Patent Application No. 2020-194699, titled "Wireless Power Supply Device", filed on November 24, 2020, the disclosure of which is incorporated herein by reference in its entirety.

[0002] The present invention relates to a housing for wireless power reception of a device and a device having the housing.

Background Art

[0003] In fields such as factory automation (FA), Internet of Things (IoT), and home appliances, various sensors, actuators, etc. are used. Generally, there are many cases where the power supply wiring of sensors and actuators has not been wirelessly implemented.

[0004] For example, when wirelessly powering a proximity sensor, it is conceivable to provide a power receiving device such as an antenna in combination with the proximity sensor. However, when receiving energy wirelessly, there are problems such as a decrease in power receiving efficiency compared to the case of cable wiring. In addition, when adding an antenna or the like to a proximity sensor, there are problems such as an increase in the overall size of the proximity sensor.

[0005] As the background art of this technical field, there is Japanese Unexamined Patent Application Publication No. 2014-7629 (Patent Document 1). This publication describes that "the proximity sensor 10 includes a first antenna 1, a second antenna 2, and a standing wave ratio detection unit 3. In the second antenna 2, the direction of change in the resonance frequency with respect to the change in the distance to the detection target is opposite to the direction of change in the resonance frequency of the first antenna 1. The standing wave ratio detection unit 3 detects a first standing wave ratio S1 on the signal line connected to the first antenna 1 and a second standing wave ratio S2 on the signal line connected to the second antenna 2." (See the abstract).

[0006] Patent Document 1 provides a proximity sensor with two different types of antennas, specifically, a loop antenna 1 and a helical antenna 2. However, in this disclosure, the loop antenna 1 and the helical antenna 2 do not receive power necessary for the operation of the proximity sensor. Further, the loop antenna 1 and the helical antenna 2 may considerably increase the overall size of the proximity sensor (see FIGS. 1 and 6). Therefore, there is a risk of degrading the usability of the proximity sensor.

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0008] The problem to be solved is to provide a housing that wirelessly receives energy to power a device and a device having the housing while suppressing an increase in size as a whole while ensuring good power reception efficiency.

Means for Solving the Problems

[0009] To solve the above problems, for example, the configuration described in the claims is adopted. 。

Effects of the Invention

[0010] According to the present invention, it is possible to wirelessly receive energy to power a device while suppressing an increase in size as a whole while ensuring good power reception efficiency. Sensor system can be provided. Problems, configurations, and effects other than those described above will be clarified by the description of the following embodiments.

Brief Description of the Drawings

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DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. It should be noted that the embodiments shown below are one of the embodiments for providing the present invention, and the content of the present invention of the present application should not be construed as being limited based on the following description.

Example

[0013] 「Overall Configuration of Power Receiving Device」 Referring to FIG. 1(A), the power receiving system 1 of this embodiment is illustrated. The power receiving system 1 includes at least a power receiving device 20 and a device 30. The power receiving device 20 receives the energy E transmitted from the power transmitting device 10 by a wireless (radio) method and supplies power to the device 30. For this reason, the power receiving device 20 completely eliminates the need to wire a physical cable for power supply between the power receiving device 20 and the power transmitting device 10. In addition, the power receiving device 20 is configured integrally with the device 30 to be powered. For this reason, the power receiving device 20 completely eliminates the need to wire a physical cable for power supply between the power receiving device 20 and the device 30. As illustrated in FIG. 1(B), the power receiving system 1 may include other components 30 and 40.

[0014] The power receiving device 20 is defined as a device that can receive the wirelessly transmitted energy E and supply power to the device 30. The power transmitting device 10 that acts in pair with the power receiving device 20 is defined as a device that can wirelessly transmit the energy E. The device 30 is a device that is supplied with power from the power receiving device 20 for its operation. In particular, the device 30 is a sensor or an actuator. The sensor is defined as an electronic device that measures a physical quantity and generates the measurement result. The actuator is defined as an electronic device that changes a physical quantity based on an input signal.

[0015] For example, the sensor may be a proximity sensor, an MR sensor, a Hall element, a displacement sensor, an inspection sensor, a discrimination sensor, a measurement sensor, a length measurement sensor, a vibration sensor, a microphoto sensor, a pressure sensor, a flow sensor, a temperature and humidity sensor, a human presence sensor, a wear sensor, an acceleration sensor, a strain sensor, a force sensor, a CMOS sensor, a photoelectric sensor, a laser sensor, an ultrasonic sensor, a touch sensor, a linear cage, a potentiometer, an image sensor, a color sensor, a LiDAR sensor, a TOF sensor, a seismic sensor, a gyro sensor, an inclination sensor, a rotation sensor, an angle sensor, a tachometer, a load cell, a fall sensor, a torque sensor, a liquid level sensor, a leak / water detection sensor, a non-contact temperature sensor, a current sensor, a power sensor, an electrostatic sensor, or an isolator, etc. Also, the actuator may be an electric actuator, a hydraulic actuator, a pneumatic actuator, a chemical actuator, a magnetorheological fluid actuator, an electrorheological fluid actuator, etc.

[0016] The power receiving system 1 including at least the power receiving device 20 and the device 30 is applicable to various application examples, for example, applicable in various fields such as factories (FA: Factory Automation), the Internet of Things (IoT), and home appliances. In the example shown in FIG. 1(A), the power receiving system 1 is built into a machine 100 such as an industrial robot (including machine tools) or a household robot (including home appliances).

[0017] The machine 100 can be configured to be used for various purposes such as clamping, lifting (pick), placing (place), assembling, painting, welding, etc. of a workpiece or a part W. For example, the machine 100 is an articulated robot that performs highly flexible operations. However, the power receiving system 1 is applicable to various application examples in addition to the illustrated machine 100. For example, the power receiving system 1 may be installed to supply power to sensors that detect objects on the factory line, such as proximity sensors and magnetic sensors, in general industrial automation equipment. Further, the power receiving system 1 may be installed to monitor the state of the office environment, such as temperature, humidity, and illuminance sensors, in overall building management. Hereinafter, the power receiving system 1 incorporated in the articulated robot 100 will be exemplified.

[0018] The articulated robot 100 generally has a plurality of (at least two) axes or joints J1a, J1b, J2a, J2b, J2c in order to operate the robot arm portion 110 and / or the robot hand portion 120 with a high degree of freedom. Generally, the larger the number of joints J1a, J1b, J2a, J2b, J2c of the articulated robot 100, the more flexible the operation becomes, but correspondingly, more precise control is required. On the other hand, the fewer the number of joints J1a, J1b, J2a, J2b, J2c of the articulated robot 100, the simpler the mechanism becomes, and the less likely it is to malfunction.

[0019] Referring to FIG. 2(C), the wiring state of the conventional sensor 30 is illustrated. As shown in the figure, when wiring the sensor 30 inside the machine 100 to supply power to the sensor 30, there were physical constraints. For example, due to the movement of the joints J1a, J1b, J2a, J2b, J2c of the articulated robot 100, problems such as the burden on the wiring of the sensor 30 (see FIG. 2), disconnection of the wiring, or maintenance of the wiring occurred. In addition, in a machine that performs highly flexible operations, such as the articulated robot 100, there was a problem that the space for wiring was limited because various components such as actuators were generally incorporated inside. Further, there was a risk of disconnection if the wiring was corroded by oil or the like. In this embodiment, the above wiring problems are avoided.

[0020] The power receiving system 1 can be applied to various machines 100 in any manner. For example, in the power receiving system 1, it is not necessary to accommodate all components inside the fingers of the robot hand unit 120 illustrated in FIG. 1(A). At this time, relatively large and bulky components may be configured to be flexible and stored in a compact manner within the space of the fingers. Also, some components may be arranged at locations away from the fingers (for example, the base of the fingers of the robot hand unit 120 or a relatively wide area in the vicinity). Further, some components can protrude outside the machine 100 as required.

[0021] Referring to FIG. 1(A), the power transmission device 10 is arranged at an appropriate location outside the multi-joint robot 100 and wirelessly transmits energy E to the power receiving device 20 via the power transmission antenna 12. There are several types of wireless power supply, but in this embodiment, preferably, wireless power supply is performed between the power transmission device 10 and the power receiving device 20 by the microwave method. In the microwave method, energy E or electric power can be transmitted relatively far. Hereinafter, as a specific example of the device 30, a proximity sensor will be exemplified.

[0022] "Proximity Sensor" Referring to FIGS. 2(A) and (B), a perspective view and a side view of a conventional proximity sensor 30 are illustrated. The proximity sensor 30 is a device used for the purpose of detecting a detection target without contacting the detection target. There are various types of proximity sensors 30 known, for example, those that react when a metal approaches. The proximity sensor 30 has the advantages of no deterioration such as wear due to non-contact, water resistance and dust resistance, and being difficult to break. In particular, the type that reacts to metal has the advantages of being less affected by dust and water droplets and having few false detections. There are various types of detection distances for the proximity sensor 30, for example, those that detect in millimeters. In particular, the proximity sensor 30 includes an inductive proximity sensor, a capacitance proximity sensor, a magnetic proximity sensor, etc.

[0023] The inductive proximity sensor mainly detects conductors such as iron, aluminum, brass, and copper as the objects to be detected. In its principle, due to the influence of an external magnetic field, it detects the magnetic loss caused by eddy currents generated on the surface of the conductor. For example, an alternating magnetic field is generated in the detection coil to detect the change in impedance caused by the eddy currents generated in the metal object serving as the detected object.

[0024] The capacitance proximity sensor mainly detects objects such as metals, resins, liquids, and powders (depending on the dielectric constant). In its principle, it detects the change in capacitance generated between the detected object and the sensor. For example, when a metal or dielectric approaches, the capacitance between the electrode inside the sensor and the ground potential increases due to the electrostatic induction effect. The oscillation amplitude increases in response to this change in the capacitance of the electrode, detecting the approach of the detected object.

[0025] The magnetic proximity sensor mainly detects magnets as the objects to be detected. In its principle, it operates the lead piece of the switch with a magnet. For example, by turning on the reed switch, it is configured so that the switch turns on.

[0026] Referring to Fig. 2(A), the inductive proximity sensor 30 is illustrated. Inside the housing 31 that constitutes the main body, a detection coil (not shown), an oscillation circuit, an oscillation state detection circuit, and an output circuit are accommodated. A detection surface 32 is provided on one end side of the housing 31, enabling the emission of a high-frequency magnetic field from the detection coil based on the oscillation circuit. When a metal object (refer to W in Fig. 1) approaches in this high-frequency magnetic field, an induced current due to the electromagnetic induction phenomenon flows in the proximity metal, causing heat loss in the metal object W. When this state occurs, the oscillation state detection circuit detects the attenuation or stop of the oscillation and outputs the result externally through the output circuit.

[0027] The proximity sensor 30 needs to be powered to perform the above detection operation and generate an electrical signal. Usually, the proximity sensor 30 is provided with a wiring connector (attachment part) 33 at the end side of the housing 31 on the side opposite to the detection surface 32. This connector 33 is usually made of metal, and a power receiving cable is connected therein (see (B) of FIG. 2). For example, the diameter of the detection surface 32 is about 18 mm, and the length of the housing 31 in the longitudinal direction is about 35 mm. However, the shape and size of the housing 31 and the detection surface 32 and the like are not limited to this embodiment. The housing 31 can be configured in various ways. For example, during use, in order to fix the detection surface 32 at a predetermined position and prevent fluctuations in the detection distance, the housing 31 has a diameter-expanded portion that can be tightened and fixed by partially expanding the diameter (see reference numerals 34, 35, 36). For example, as the diameter-expanded portion, it may be configured to include nuts 34, 35 and washers 36 so that the housing 31 can be tightened and fixed. Therefore, the housing 31 can be separated into two at the boundary of this diameter-expanded portion.

[0028] "Wireless conversion" For the purpose of detecting an object, the proximity sensor 30 needs to be provided in proximity to the object. Generally, when the proximity sensor 30 is installed near the object (workpiece W) to be detected, a situation may occur where the proximity sensor 30 collides with the workpiece W. In such a case, the proximity sensor 30 may be damaged. For this reason, it is said that the replacement frequency of the proximity sensor 30 is relatively high. For example, the proximity sensor 30 may be replaced about once every three months.

[0029] Replacing the wiring of the proximity sensor 30 requires two steps: attaching the cable and routing the cable (see (C) of FIG. 2). Generally, various cable lengths such as 2 m, 5 m, and 10 m are prepared for the cable of the proximity sensor 30, and it is necessary to attach each cable to a controller or the like according to the equipment. The occurrence of the above steps means that labor costs for factory workers are incurred. There are companies that estimate the hourly wage of workers at 4000 yen and the loss of the production line stop at 3 million yen per minute.

[0030] In this embodiment, the receiving device 20 receives the energy E transmitted from the power transmission device 10 by a microwave method, and powers the proximity sensor 30 to address the above problems. However, in the microwave method, there is an upper limit to the capacity of the energy E that can be transmitted. Also, compared to the wired case, there is a problem that the power reception efficiency of the energy decreases. Further, there is a problem that the amount of power that can be supplied from the power transmission device 10 to the receiving device 20 decreases in inverse proportion to the square of the distance according to Friis' law.

[0031] Generally, the proximity sensor 30 operates at about 12 to 24 V and 3 to 1000 mA. That is, in terms of power, at least about 36 mW of power consumption is required. However, in wireless power supply by the microwave method, it may be possible to supply only about 1 to 10 mW of power to a power supply target 1 m away. That is, in order to wirelessly power the proximity sensor 30, reducing the power consumption of the proximity sensor 30 becomes one issue.

[0032] Regarding the above "reduction of power consumption of the proximity sensor", it may be possible to solve it by newly developing a proximity sensor 30 for specific applications for low power consumption. However, generally, in order to newly develop a product, a period of about 1 to 5 years is required as a whole. Therefore, in the manufacturing industry, it is often done to divert products for civilian equipment to in-vehicle products. In this case, the required period may be shortened to about 1 year. In this embodiment, it is assumed that by using the existing proximity sensor 30 compatible with 12 to 24 V as it is, it is not necessary to newly develop a low power consumption type proximity sensor. Therefore, the applicant conducted the following tests.

[0033] First, the applicant conducted a test to verify how the proximity sensor 30 operates when power is supplied to the existing proximity sensor 30 compatible with 12 to 24 V at a power lower than the recommended value. Referring to Fig. 3(A), it shows the transition of the power of the proximity sensors with respect to the change in the power supply voltage when a voltage lower than the recommended value is supplied to two different commercially available proximity sensors (a, b) compatible with 12 to 24V. In this figure, the horizontal axis of the graph shows the supply voltage (V), and the vertical axis shows the power (mW). The supply voltage was lowered for the existing proximity sensors compatible with 12 to 24V. When the voltage was lowered to about 6V, it was verified that the proximity sensors operated as specified. Usually, when an object is detected, the output of the proximity sensor becomes Low. At this time, the power consumption becomes smaller as the power supply voltage is lowered. However, it was confirmed that a power consumption of about 30mW still occurred.

[0034] Referring to Fig. 3(B), following Fig. 3(A), it shows the transition of the power of the proximity sensors when the power supply voltage is further lowered. As shown in this figure, when the voltage is lowered to about 5.2V, the power consumption is about 6mW. That is, it was confirmed that the proximity sensor 30 can operate with a supply amount of about 10mW. Thus, it was verified that even when the supply voltage is significantly lowered from the recommended value for the existing proximity sensors compatible with 12 to 24V, the power requirements can be met. In this case, the need to research and develop a new proximity sensor compatible with 5 to 6V can be avoided. However, when the power consumption is reduced, it was confirmed that the proximity sensor operates differently compared to the normal time (when operating at the recommended 12 to 24V).

[0035] Referring to Fig. 4(A), as shown in Fig. 3(B), when the power supply voltage is significantly reduced (to 6V or less) from the recommended value, the output waveform shown by the proximity sensor 30 is presented. As can be understood from the figure, the output voltage appears as positive when the object is not close (refer to V0), but when the object is detected, the output voltage appears as a large negative value (refer to V1). In the normal usage state, the proximity sensor maintains a state where the output voltage is lowered when the object is detected, i.e., "object detection = Low output". However, as shown in Fig. 3(B), when a voltage significantly lower than the recommended value is supplied, the above "object detection = Low output" is not satisfied in the entire time domain, and it was found that the proximity sensor operates intermittently. That is, it was confirmed that the proximity sensor periodically outputs the output voltage alternately as positive (refer to V0) and negative (refer to V1), even though the object detection continues. Let the period of this intermittent operation be T period Then, it was confirmed that when the object is detected, a downward output voltage waveform appears every period T period

[0036] Furthermore, the applicant of the present application conducted a test to confirm the regularity of the intermittent operation of this proximity sensor. Referring to Fig. 4(B), in the case of Fig. 4(A) above, a graph with the supply voltage (V) on the horizontal axis and time (msec) on the vertical axis is shown. As a result, it was found that there is a relationship as shown in the graph of Fig. 4(B) with respect to the period T period of the intermittent operation illustrated in Fig. 4(A). That is, for one type (a) of the proximity sensor, it was found that as the supply voltage is further reduced from 6V, the magnitude of the above-mentioned period T period increases almost proportionally. It was confirmed that the same result can be obtained for another type (b) of the proximity sensor. Thus, it was found that there is a relationship between the intermittent operation and the periodic variation of the proximity sensor.

[0037] ​Hereinafter, a state in which the proximity sensor exhibits intermittent operation due to the power supply voltage of the proximity sensor being considerably lower than the recommended value is referred to as a low power mode (a mode that enables operation with power consumption approximately one-fifth that of the existing operation method). Also, a state in which the power supply voltage of the proximity sensor satisfies the recommended value and the proximity sensor does not exhibit intermittent operation is referred to as a normal power mode. Note that the low power mode may include a mode that enables operation with power consumption ranging from less than one-fourth to approximately one-fifth that of the existing operation method.

[0038] In the low power mode, since the proximity sensor 30 exhibits intermittent operation (see (A) of FIG. 4), there is a problem in directly using its output. In this embodiment, in such a case, it is possible to circuitously distinguish between a state where there is no need to detect an object (no object) or a state where an object is detected after a long time interval (the object is replaced) and a state where an object is present. That is, the period T of the intermittent operation period appears at relatively short time intervals as illustrated in (A) of FIG. 4. The magnitude of this time interval is approximately proportional to the power supply voltage as illustrated in (B) of FIG. 4, and thus can be estimated based on the power supply voltage. Therefore, by utilizing the fact that the intermittent operation of the proximity sensor can be predicted based on the power supply voltage, it is possible to distinguish whether the proximity sensor is detecting an object.

[0039] Referring again to (B) of FIG. 1, the power receiving system 1 includes a power receiving device 20, a proximity sensor 30, a period filter 40, and a controller 50. In this circuit, the output of the proximity sensor 30 is passed through the period filter 40 and then transmitted to the controller 50. The period filter 40 is an element that can distinguish between relatively rapid High / Low changes (in the low power mode, when detecting an object) and no change (when there is no object). For example, referring to (B) of FIG. 4, assume that a voltage of 5.5V is supplied to the proximity sensor (a). At this time, the proximity sensor (a) has a period T of 20.4 msec periodIt can be inferred that it operates intermittently. Therefore, corresponding to the magnitude of this cycle, the output of the proximity sensor 30 is passed through the periodic filter 40. As a result, when the proximity sensor 30 detects the object W in the low power mode and shows intermittent operation, it is possible to derive the same output result as in the normal power mode.

[0040] Therefore, in the power receiving system 1, even when the conventional proximity sensor 30 of about 12 to 24 V operates in the low power mode (about 5 to 6 V), it is possible to avoid misrecognition of the output of the sensor. However, the power receiving system 1 is not limited to the configuration shown in Fig. 1(B). The power receiving system 1 is applicable to various types of devices (sensors or actuators) 30, and depending on the type of the device 30, in addition to the low power mode, the device 30 may be operated in the normal power mode. Therefore, the power receiving system 1 does not necessarily have to include the periodic filter 40.

[0041] "Power receiving antenna" Next, the power receiving device 20 used in the power receiving system 1 illustrated in Figs. 1 to 4 will be described. In the present embodiment, the power receiving device 20 is configured as a power receiving antenna. In particular, since the power receiving antenna is configured by using the housing 31 (see Fig. 2(A)) that constitutes the main body of the device 30 to be powered, the power receiving device 20 is provided integrally with the device 30.

[0042] The overall configuration of the power receiving device 20 is schematically illustrated in Figs. 5 to 7. Fig. 5(A) illustrates a case where a dipole antenna 21 is used as the power receiving device 20. For example, the dipole antenna 21 is attached to the housing 31 of the proximity sensor 30 to function as an antenna that generates electric field radiation. Usually, the proximity sensor 30 has a metal main body or housing 31, but the periphery of the dipole antenna 21 must not be metal and should be resin or the like (non-metal).

[0043] In Fig. 5(B), an example is shown where a slot antenna 22 is used as the power receiving device 20. For example, a suitable cavity is provided inside the metal housing 31 of the proximity sensor 30, and a slot is formed through its wall to function as an antenna that generates magnetic field radiation.

[0044] What is shown in Fig. 5(C) is an example where the dipole antenna 21 and the slot antenna 22 are combined and used as the power receiving device 20. In this case, the dipole antenna 21 and the slot antenna 22 are arranged continuously and linearly in the longitudinal direction. These two antennas 21 and 22 have a total length of about 300 mm.

[0045] The dipole antenna 21 and the slot antenna 22 shown in Fig. 5(C) are provided aligned in the same direction with respect to each other. However, the acting directions of both antennas appear to be orthogonal to each other. This is because the dipole antenna 21 acts mainly based on the electric field, while the slot antenna 22 acts mainly based on the magnetic field, so their acting directions intersect.

[0046] Referring to Fig. 6, the results of simulating the power receiving situation of each antenna in a three-dimensional space for the power receiving device 20 illustrated in Fig. 5(C) are shown. Fig. 6(A) schematically shows the directivity of the dipole antenna 21. Fig. 6(B) schematically shows the directivity of the slot antenna 22. In these figures, the intensity of the directivity of each antenna increases as the color becomes darker. As can be understood from the figure, by combining two different types of antennas 21 and 22 to form the power receiving device 20, it is possible to form an omnidirectional non-directional antenna as a whole.

[0047] For example, in the X-axis direction of FIG. 6(A), the dipole antenna 21 has a region where the directivity of the antenna weakens as shown by reference numeral 21A. In contrast, in the X-axis direction of FIG. 6(B), the slot antenna 22 has a region where the directivity of the antenna strengthens as shown by reference numeral 21B. Since these regions 21A and 21B overlap each other, in the X-axis direction, the degradation of the function of the dipole antenna 21 can be compensated by the function of the slot antenna 22.

[0048] Also, in the Y-axis direction of FIG. 6(A), the dipole antenna 21 has a region where the directivity of the antenna strengthens as shown by reference numeral 22A. In contrast, in the Y-axis direction of FIG. 6(B), the slot antenna 22 has a region where the directivity of the antenna weakens as shown by reference numeral 22B. Since these regions 22A and 22B overlap each other, in the Y-axis direction, the degradation of the function of the slot antenna 22 can be compensated by the function of the dipole antenna 21.

[0049] Also, in the Z-axis direction of FIG. 6(A), the dipole antenna 21 has a region where the directivity of the antenna strengthens as shown by reference numeral 23A. In contrast, in the Z-axis direction of FIG. 6(B), the slot antenna 22 has a region where the directivity of the antenna weakens as shown by reference numeral 23B. Since these regions 23A and 23B overlap each other, in the Z-axis direction, the degradation of the function of the slot antenna 22 can be compensated by the function of the dipole antenna 21.

[0050] Thus, the directivities of the dipole antenna 21 and the slot antenna 22 do not appear uniformly in the three-dimensional space but appear with strengths and weaknesses, and their distributions are different for both. By combining these two, the region where the directivity of the dipole antenna 21 weakens can be compensated by the slot antenna 22, and vice versa. Therefore, the two antennas 21 and 22 are configured to complement each other's antenna directivities. For this reason, as a whole, the combination of the antennas 21 and 22 is configured to be able to receive power in almost all directions without showing particular loss of directivity. This configuration can be achieved simply by arranging the two antennas 21 and 22 linearly with respect to each other, as illustrated in Fig. 5(C), without the need to complexly adjust the orientations of both.

[0051] Referring to Fig. 7, simulation results are shown for the above-described dipole antenna 21 and slot antenna 22, with the frequency (GHz) on the horizontal axis and the efficiency of the antenna (assuming 100% as ideal) on the vertical axis. As can be understood from the figure, it was verified that when the frequency was changed from 0.8 to 1.0 GHz, each antenna could exhibit a high efficiency exceeding approximately 99%. Therefore, it was confirmed that the power receiving device 20 shown in Figs. 5(A) to 5(C) can suitably receive power.

[0052] Next, with reference to Figs. 8 to 10, a specific implementation example of the power receiving device 20 schematically illustrated in Figs. 5 to 7 will be described. Referring to Fig. 8, a perspective view of a proximity sensor 30 integrally provided with the power receiving device 20 according to this embodiment is shown. This figure corresponds to an implementation example in the case of combining the dipole antenna 21 and the slot antenna 22 illustrated in Fig. 5(C).

[0053] As illustrated in Fig. 5(A), as the power receiving device 20, a dipole antenna 21 is provided at the end of the metal housing 31 of the proximity sensor 30. Usually, the proximity sensor 30 has a metal connector 33 for wired power supply (see Fig. 2), and the dipole antenna 21 may be attached using this part. The dipole antenna 21 has a rod-shaped main body and extends linearly along the longitudinal direction of the housing 31. In the conventional proximity sensor 30, a wiring cable was extended from the end on the side opposite to the detection surface 32 of the housing 31 (see Fig. 2(C)). However, in this embodiment, such a cable is made unnecessary, and the dipole antenna 21 is attached to the end of the housing 31 using the vacant space. At this time, the metal of the conventional connector 33 of the proximity sensor is used as the GND of the antenna. Therefore, the dipole antenna 21 may be provided on the housing 31 by replacing the conventional connector 33.

[0054] As illustrated in Fig. 5(B), as the power receiving device 20, a slot antenna 22 is provided by drilling a vertically long slot along the longitudinal direction on the metal housing 31 of the proximity sensor 30. This slot penetrates the wall of the housing 31 in the thickness direction of the housing 31. This slot extends linearly along the longitudinal direction of the housing 31, but is provided so as not to penetrate the end of the housing 31 (see reference numeral 37). When drilling a slot in the housing 31, it is possible to cover the coil, circuit, etc. with metal or resin in order to protect the internal coil, circuit, etc. from the intrusion of oil. Also, when the housing 31 is made of a non-metal material, it is possible to make it act as the slot antenna 22 by attaching a metal film to the slot penetrating the wall of the housing 31 or adding a metal part.

[0055] As illustrated in (C) of FIG. 5, the dipole antenna 21 and the slot antenna 22 are arranged linearly and continuously with respect to each other along the longitudinal direction of the housing 31 of the proximity sensor 30. In the height direction, the dipole antenna 21 and the slot antenna 22 are offset from each other (see reference numeral 38). This difference in the height direction does not cause any particular disadvantage to the directivity of each antenna. Thus, the housing 31 has a size in the three-dimensional space (X-axis, Y-axis, and Z-axis directions), and the expansion of the size of the housing 31 in the three-dimensional space due to the provision of the power receiving devices 21 and 22 is limited to a maximum of substantially one axial direction (X-axis direction). In particular, in the case of the slot antenna 22, the expansion of the size of the housing 31 can be completely eliminated.

[0056] Therefore, in the present embodiment, the power receiving device 20 is mounted on the housing 31 of the proximity sensor 30 without significantly changing the configuration of the existing proximity sensor 30. The power receiving device 20 preferably includes a dipole antenna 21 and a slot antenna 22, and can receive energy E from all directions. Each antenna 21, 22 may be functionally connected to a rectifier (rectifier) within the housing 31. The rectifier is an element having a rectifying action of allowing current to flow only in one direction, and converts the RF (electromagnetic wave) received by each antenna 21, 22 into DC (direct current voltage). The antennas 21, 22 and the rectifier may be integrally configured. As will be described later, the rectifier may be integrated with a chip antenna. Thus, the antennas 21, 22 may rectify and convert microwaves into direct current.

[0057] When the proximity sensor 30 is used in a FA machine 100 or the like, oil resistance is required. When oil is used near or inside and outside the machine 100, the housing 31 of the proximity sensor 30 gets oil on it, and its corrosion becomes a problem. For this reason, the material of the housing 31 of the proximity sensor 30 is selected considering oil resistance. In this embodiment, an antenna (dipole antenna 21 and slot antenna 22) may be incorporated into the housing 31 of the proximity sensor 30 in consideration of problems specific to FA. At this time, by arranging the antenna using the metal of the housing 31, in energy harvesting, it may have the advantages specific to wireless power supply by microwaves.

[0058] Referring to FIG. 9, based on the configuration shown in FIG. 8, the results of simulating the power reception status of each antenna 21, 22 in a three-dimensional space are shown. (A) of FIG. 9 shows the directivity of the dipole antenna 21. (B) of FIG. 9 shows the directivity of the slot antenna 22. In these figures, the darker the color, the stronger the directivity intensity of the antennas 21, 22.

[0059] As can be understood from FIG. 9, similar to the case shown in FIG. 6, in the region where the directivity of the slot antenna 22 weakens, it can be compensated by the region where the directivity of the dipole antenna 21 strengthens. Also, in the region where the directivity of the dipole antenna 21 weakens, it can be compensated by the region where the directivity of the slot antenna 22 strengthens. Therefore, the two antennas 21, 22 of different types are configured to complement each other in the regions where the directivities of both weaken. For this reason, overall, these antennas 21, 22 can receive power in almost all directions without showing particular loss of directivity.

[0060] As described above, a verification by simulation was performed on an omnidirectional antenna that can be used for an antenna for a factory by taking advantage of the radiation characteristics of the dipole antenna 21 and the slot antenna 22. As a result, it was confirmed that, although the respective antennas 21 and 22 are provided aligned in the same direction (the longitudinal direction of the proximity sensor), radiation patterns are formed in a shape orthogonal to each other at 90 degrees. Therefore, the present embodiment constitutes an omnidirectional antenna that uses the shape of the existing sensor 30 as it is.

[0061] Referring to FIG. 10, for the power receiving device 20 illustrated in FIG. 8, the simulation results are shown when the frequency (GHz) is on the horizontal axis and the efficiency (assuming 100% as ideal) of each of the antennas 21 and 22 is on the vertical axis. As can be understood from the figure, when the frequency is changed from 0.8 to 1.0 GHz, it was verified that the dipole antenna 21 shows a high efficiency of about 99%, and the slot antenna 22 can show a high efficiency of about 86%. Therefore, it was verified that the configuration using the combination of the slot antenna 21 and the dipole antenna 22 illustrated in FIG. 8 is particularly suitable.

[0062] As described above, the power receiving device 20 having the antennas 21 and 22 configured by using the shape of the housing 31 of the existing proximity sensor 30 as it is has been described. It should be understood that the application target of this power receiving device 20 is not limited to proximity sensors and can be applied to other types of devices (sensors or actuators) 30. Also, as illustrated in FIGS. 5(A) and 5(B), in the mounting example of FIG. 8 as well, it is possible to provide only one of these antennas 21 and 22.

[0063] Although known to those skilled in the art, when wirelessly transmitting energy E between the power transmitting device 10 and the power receiving device 20, the power receiving efficiency of the power receiving device 20 decreases as compared with the case of using a wire. For example, in the case of wireless, in space, the power reception may be only about 0.4% at a distance of 1 m. Next, with reference to FIGS. 11 to 14, means for improving the power receiving efficiency of the power receiving device 20 during use will be described.

[0064] Referring to FIG. 11(B), an example is shown in which the power transmission device 10 and the power reception device 20 are accommodated separately from each other in a chamber (box) 90 that defines a closed space (space) of a rectangular parallelepiped inside. The chamber 90 improves the efficiency of wirelessly transmitting energy E between the two by confining the power transmission device 10 and the power reception device 20 in the closed space defined inside. Although not shown in the figure, it is possible to accommodate all or part of the machine 100 illustrated in FIG. 1 in this chamber 90.

[0065] In FIG. 11(B), the chamber 90 has a rectangular parallelepiped shape or a polygonal shape, but this shape can be variously changed according to the embodiment. For example, the corners do not have to be configured at right angles, and chamfering or the like can be performed. Therefore, the number of side surfaces of the chamber 90 is not limited to six. Also, the shape of each side surface of the chamber 90 is not limited to a quadrilateral.

[0066] Referring to FIG. 11(C), the result of simulating the movement of electromagnetic waves in the chamber 90 illustrated in FIG. 11(B) is shown. In FIG. 11(A), the state at that time is illustrated. As shown in FIG. 11(C), the electromagnetic waves transmitted in the chamber 90 are reflected by each side surface that defines the boundary of the chamber 90. Finally, these electromagnetic waves are reflected infinitely in the closed space, and the energy is confined in the chamber 90. For this reason, the power reception device 20 can receive the energy sent from the power transmission device 10 from various directions. Therefore, compared with the case of receiving energy only from one direction without using the chamber 90 (refer to the reference symbol E in FIG. 1(A)), the power reception device 20 can receive energy from multiple directions.

[0067] Referring to FIG. 12, the simulation results are shown for the chamber 90 illustrated in FIG. 11, with the frequency (GHz) on the horizontal axis and the efficiency (dB) of each antenna on the vertical axis. In this simulation, five parameters (see S1,1, S3,1, S2,2, S3,2, S3,3 in FIG. 14) are taken, and the magnitude is shown in dB. From this simulation result, it was confirmed that at least a five-fold performance improvement can be obtained within the chamber 90, and generally, an approximately six-fold performance improvement can be obtained.

[0068] By using the chamber 90, energy can be confined therein. In this embodiment, further, means for concentrating energy on the power receiving device 20 can be provided. Referring to FIGS. 13(A) and (B), it is illustrated that a stirring fan 91 is installed as electromagnetic wave reflecting means on the ceiling portion of the chamber 90. The stirring fan 91 is configured such that a pair of reflecting surfaces 93, 94 rotate in a fan shape or a propeller shape around a rotation axis 92. The pair of reflecting surfaces 93, 94 extend in opposite directions in the longitudinal direction and extend linearly as a whole. However, the number, size, shape, angle, etc. of the reflecting surfaces 93, 94 can be variously changed according to the embodiment.

[0069] As illustrated in FIG. 13(A), the stirring fan 91 can reflect the electromagnetic waves that have escaped upward from below the chamber 90 to the ceiling on the surfaces of the reflecting surfaces 93, 94, and thus send the energy back downward again. For this reason, the power receiving device 20 can receive the energy reflected from the stirring fan 91 in addition to the energy directly sent from the power transmitting device 10 and the energy sent after being reflected by the wall of the chamber 90.

[0070] The reflecting surfaces 93, 94 are configured as movable types so as to be able to follow the change in the position of the power receiving device 20. For example, as illustrated in FIGS. 13(A) and (B), the pair of reflecting surfaces 93, 94 may change the relative position of the stirring fan 91 with respect to the chamber 90 by rotating around the central rotation axis 92. Therefore, as illustrated in FIG. 1(A), when the power receiving device 20 changes its relative position with respect to the power transmitting device 10, the stirring fan 91 rotates in accordance with the change in the position, and the positions of the reflecting surfaces 93 and 94 are changed. As a result, in accordance with the change in the position of the power receiving device 20, the power receiving device 20 can always receive energy with high efficiency.

[0071] For example, as shown in FIG. 13(A), when the pair of reflecting surfaces 93 and 94 extend substantially straight along the longitudinal direction of the chamber 90, the energy that escapes upward from the power transmitting device 10 can be reflected and sent farther in the longitudinal direction (vertical direction). Therefore, this is suitable when straightness of energy is required during power transmission. Also, as shown in FIG. 13(B), when the pair of reflecting surfaces 93 and 94 extend substantially in the intersecting direction along the longitudinal direction of the chamber 90, the energy that escapes upward from the power transmitting device 10 can be reflected and sent in the direction intersecting the longitudinal direction (lateral direction). Furthermore, the pair of reflecting surfaces 93 and 94 can be rotated about the central rotation axis 92 to variously adjust the position and direction of reflecting the energy.

[0072] Referring to FIGS. 13(A) and 13(B), further, a fixed reflecting surface 95 can be installed on the side surface of the chamber 90. As described above, each side surface of the chamber 90 reflects electromagnetic waves. The reflecting surface 95 can reflect electromagnetic waves with a reflectivity different from that of the side surface of the chamber 90. By changing the reflection efficiency at each side surface of the chamber 90, the electromagnetic waves reflected in the chamber 90 may be made to more intensively direct toward the power receiving device 20. For example, the reflecting surface 95 may be configured as a metasurface. In this way, in mid- to long-distance wireless power feeding, reflected waves can be utilized to maximize the received power of the receiver.

[0073] Referring to FIG. 14, an example is illustrated in which a metasurface 96 is provided as a fixed reflecting surface on the side surface of the machine 100. In the FA robot 100 (see Fig. 1), since the robot arm part 110, the robot hand part 120, the main body of the robot 100, etc. are made of metal, there are many reflected waves. Therefore, as illustrated in Fig. 14(A), these reflected waves can be used to reflect electromagnetic waves toward the power receiving device 20.

[0074] As illustrated in Fig. 14(B), further, by providing the metasurface 96 on the side surface of this machine 100, the electromagnetic waves may be reflected more concentratedly toward the power receiving device 20. As illustrated in Fig. 14(C), the metasurface 96 is configured by arranging a plurality of small elements 98 on a substrate 97. Each element 98 has its shape and arrangement determined so as to obtain a suitable reflection efficiency. For this reason, the metasurface 96 can reflect electromagnetic waves and collect them toward the power receiving device 20. As a result, the energy transmitted from the power transmission device 10 can be sent more efficiently toward the power receiving device 20.

[0075] As described above, the power receiving device 20 of this embodiment constitutes an omnidirectional non - directional antenna that utilizes the shape of an existing device (sensor or actuator) 30 as it is. When in use, by using the chamber 90, the power receiving efficiency of the power receiving device 20 can be improved. Further, when uniformization of the electromagnetic field is required, a stirring fan 91 may be provided in the chamber 90. Furthermore, by providing the metasurfaces 95 and 96 on the side surface of the chamber 90 or on the main body of the FA robot 100, the power receiving efficiency of the power receiving device 20 may be further improved.

[0076] Referring to Fig. 15, a modified example of the power receiving system 1 illustrated in Fig. 1(B) is illustrated. The system 1 shown in the figure includes a power receiving device 20 that wirelessly receives energy from the power transmission device 10, a device (proximity sensor) 30 that is powered by the power receiving device 20, a device (periodic filter) 40 that adjusts the output of the device 30, and a controller 50. When the proximity sensor 30 recognizes the position of the object W due to a magnetic field change, it generates a signal. In the low power consumption mode, a periodic signal (H / L) is generated. By passing this signal through the periodic filter 40, a signal (L) similar to that in the normal power mode can be obtained. By generating this signal, the controller 50 can utilize the output result of the proximity sensor 30 without misrecognition. The controller 50 has a microcomputer and a wireless communication function, and further transmits the signal sent from the proximity sensor 30 to an external controller 60 for use in controlling the machine tool 70. The machine tool 70 may be all or part of the machine 100, or may be another machine.

[0077] Here, making the device 30 drivable by wireless power supply means that if the data transmission is also made wireless, the complete wirelessization of the device 30 can be achieved. For example, as illustrated in (B) of FIG. 3 and (B) of FIG. 4, the proximity sensor 30 is expected to be drivable with about 6 mW, and its data transmission is expected to be drivable with about 1 mW. Therefore, if the power receiving device 20 can supply about 7 mW of energy to the proximity sensor 30, the complete wirelessization of the proximity sensor 30 can be achieved. In microwave-based wireless power supply, power up to about 10 mW can be supplied to a power receiving object 1 m away, so the complete wirelessization of the proximity sensor 30 is possible. This also applies to sensors and actuators different from the proximity sensor 30.

[0078] As illustrated in (B) of FIG. 1, the power receiving device 20 may supply power only to the device 30. Also, as illustrated in FIG. 15, the power receiving device 20 may supply power to the periodic filter 40 and the controller 50 in addition to the device 30. Furthermore, it is also possible to add other power sources to the power receiving system 1. For example, as illustrated in FIG. 15, in order to ensure the minimum power supply voltage of the proximity sensor 30, it is also possible to combine a vibration power generation element 80 with the proximity sensor 30.

[0079] Regarding the power receiving system 1 illustrated in (B) of FIG. 1 and FIG. 15, various modifications can be made. In this figure, in order to achieve full wireless operation of the proximity sensor 30 without the need for new development of the proximity sensor, a periodic filter 40 is included, but this element can be made unnecessary depending on the device to be powered. Also, for example, as illustrated in (B) of FIG. 4, since the filter constant depends on the power supply voltage of the proximity sensor 30 (substantially equal to the received power), the power receiving system 1 illustrated in (B) of FIG. 1 and FIG. 15 may be extended so that this information is fed forward to the periodic filter 40 and the controller 50.

Embodiment

[0080] As described above, in FIGS. 5 to 10, the power receiving device 20 is configured to utilize the radiation characteristics of the dipole antenna 21 and / or the slot antenna 22. However, the power receiving device 20 is not limited to this embodiment. Next, referring to FIGS. 16 to 20, another embodiment of the power receiving device 20 illustrated in FIGS. 5 to 10 will be described. In this embodiment, the power receiving device 20 is at least one of a dipole antenna, a slot antenna, a monopole antenna, a chip antenna, and an inverted F antenna.

[0081] Referring to FIG. 16(A), a perspective view is illustrated in which a short dipole antenna 210 is provided as the power receiving device 20 on the housing 31 of the device (proximity sensor) 30. Depending on the mounting location of the device, it may not be preferable to extend the dipole antenna 210 so as to protrude significantly outward from the housing 31. Therefore, in the embodiment of FIG. 16(A), the dipole antenna 210 is provided with a relatively short length so as to suppress the protruding portion from the housing 31. As described above, this dipole antenna 210 may be configured using the connector 33 of the conventional proximity sensor 30.

[0082] In the embodiment of FIG. 16(A), as a difference from the embodiment illustrated in FIG. 8, a slot antenna is not provided on the housing 31. For this reason, since the housing 31 is configured to be completely sealed, when applied to the machine 100 by FA or the like, it is possible to completely prevent surrounding oil or the like from entering the housing 31.

[0083] Referring to FIG. 16(B), it shows the simulation result of the power reception state of the short dipole antenna 210 illustrated in FIG. 16(A). As can be understood from the figure, it was found that even when the length of the dipole antenna 210 was kept relatively short, the same antenna directivity as that in the case illustrated in FIG. 9(A) could be ensured.

[0084] Referring to FIG. 17(A), a perspective view of the housing 31 of the proximity sensor 30 with a slot antenna 220 formed therein as a power receiving device 20 is illustrated. The blackened portion corresponds to the dipole antenna 210 in FIG. 16(A), enabling comparison of the positions and sizes of both antennas. As is known to those skilled in the art, the housing 31 of the proximity sensor 30 can be configured in various ways by manufacturers. In this embodiment, although the slot antenna 220 has been formed by directly using the existing housing 31 of the proximity sensor 30, a newly designed housing 31 with slots may also be used.

[0085] For example, in the embodiment illustrated in FIG. 8, when there is a step (see reference numeral 38 in FIG. 8) in the housing 31, the length of the slot that can be formed horizontally on the housing 31 may be limited. In the embodiment of FIG. 17(A), as a difference from the embodiment illustrated in FIG. 8, a relatively large housing 31 is provided so that the housing 31 extends straight in the horizontal direction, eliminating the step (see reference numeral 38 in FIG. 8) and enabling the formation of a slot with a sufficient length. For example, a slot with an arbitrary length up to about 70%, about 80%, about 90%, or about 100% of the total length in the major axis direction of the housing 31 (from the end on the 34 side to the end on the 33 side of the main body 31) may be formed. When forming a slot in the housing 31, it is possible to cover the coil, circuit, etc. inside with metal or resin in order to protect them from the intrusion of oil.

[0086] Referring to FIG. 17(B), it shows the simulation result of the power reception state of the slot antenna 220 illustrated in FIG. 17(A). As can be understood from the figure, it was found that even when the length of the slot antenna 220 is increased, the same antenna directivity as that illustrated in FIG. 9(B) can be ensured. Comparing FIG. 16(B) and FIG. 17(B), it was confirmed that the antenna directivity of the dipole antenna 210 and the antenna directivity of the slot antenna 220 intersect with each other. This is the same as the cases illustrated in FIGS. 6(A), (B) and FIGS. 9(A), (B).

[0087] Referring to FIG. 18(A), a perspective view of a monopole antenna 230 provided as a power receiving device 20 on the housing 31 of the proximity sensor 30 is illustrated. The blackened part corresponds to the dipole antenna 210 in FIG. 16(A), and the positions and sizes of both antennas can be compared. The monopole antenna 230 is also called a rod antenna, and compared with the dipole antenna 210, it has a smaller diameter and is more slender. In order to ensure the power reception efficiency of the monopole antenna 230, it is necessary to ensure its length. Therefore, in the embodiment, one end of the monopole antenna 230 is attached to the housing 31 in the vicinity of the nuts 34, 35 and the washer 36 for tightening and fixing the housing 31, and the other end extends straight in the opposite direction. By aligning the extending direction of the housing 31 and the extending direction of the monopole antenna 230, the overall size is suppressed from becoming bulky.

[0088] Referring to FIG. 18(B), it shows the simulation result of the power reception state of the monopole antenna 230 illustrated in FIG. 18(A). Comparing (B) of FIG. 16 and (B) of FIG. 18, it was confirmed that the antenna directivities of the dipole antenna 210 and the monopole antenna 230 appear in the same direction. It was also confirmed that good directivity can be obtained even when the monopole antenna 230 is used instead of the dipole antenna 210. Further, comparing (B) of FIG. 17 and (B) of FIG. 18, it was confirmed that the antenna directivities of the monopole antenna 230 and the slot antenna 220 cross each other.

[0089] Referring to FIG. 19, a comparison of the sizes between the conventional proximity sensor 30 illustrated in (B) of FIG. 2 and the monopole antenna 230 illustrated in (A) of FIG. 18 is shown. As shown in FIG. 19(A), the housing 31 of the conventional proximity sensor 30 extends in the longitudinal direction, and its size is denoted as L0. The housing 31 of the proximity sensor 30 has diameter-expanded portions for fastening and fixing (see reference numerals 34, 35, and 36) on one end side, and a connector 33 on the other end side.

[0090] As shown in FIG. 19(A), the monopole antenna 230 is provided in proximity to the diameter-expanded portion for fastening and fixing, and extends in the same direction (parallel to the longitudinal direction of the housing 31) along the longitudinal direction of the housing 31 toward the other end portion 33. As a result, the length L1 of the monopole antenna 230 configured to be elongated can be immersed within the length L0 in the longitudinal direction of the housing 31 by the length L2 up to the end portion 33 on the side opposite to the diameter-expanded portion for fastening and fixing of the housing 31. As a result, with respect to the housing 31, the expansion L3 in the one-axis direction in the three-dimensional space due to the addition of the monopole antenna 230 can be suppressed to a maximum of twice or less with respect to the length L0 in the longitudinal direction of the housing. Depending on the embodiment, the expansion L3 in the one-axis direction in the three-dimensional space may be suppressed to a maximum of 1.5 times or less with respect to the length L0 in the longitudinal direction of the housing. Also, by making L1 bendable, the length of L3 may be substantially reduced to zero.

[0091] As shown in (B) of FIG. 19, the monopole antenna 230 is completely accommodated within the original size of the housing 31 in the width W0 direction of the housing 31. Thus, on the side of the working surface (detection surface 32) of the sensor 30, there is no change in the size of the housing 31. On the side opposite to the working surface (detection surface 32) of the sensor 30, although the length of the housing 31 extends, since the wiring is made unnecessary (see (C) of FIG. 2), the problem of space due to the length of L3 is substantially suppressed. Therefore, the housing 31 has a size in the three-dimensional space (X-axis, Y-axis, and Z-axis directions), and the expansion of the size of the housing 31 in the three-dimensional space due to the provision of the monopole antenna 230 is limited to a maximum of substantially one-axis direction (X-axis direction).

[0092] Referring to FIG. 20, for the three types of modification examples illustrated in FIGS. 16 to 19, the power reception efficiency of the antenna is shown respectively. As can be understood from the figure, when only the relatively short dipole antenna 210 is used, it was found that its power reception efficiency is the lowest. Also, when the slot antenna 220 is provided, although it does not reach 90%, it exceeds 80% and can achieve a relatively good power reception efficiency. Furthermore, when the monopole antenna 230 is used, its power reception efficiency is significantly increased and it was found to show an ideal value close to 100%.

[0093] When the installation location of the proximity sensor 30 is a movable member such as the robot hand portion 120, the position and direction of the power reception antenna vary. In order to maintain a good power supply status of the proximity sensor 30 in the three-dimensional space, it is desirable that the power reception device 20 maintains a good power reception efficiency in each of the six directions (front-back, left-right, up-down six directions) in the three-dimensional space. When only the short dipole antenna 210 is used, it was found that it can show a good power reception efficiency only at a relatively small angle with respect to the change in the rotation angle. However, as a whole, it can show a relatively good stability in six directions.

[0094] When using the monopole antenna 230, the best power reception efficiency can be shown (see Fig. 20). However, since it is necessary to attach an elongated rod-shaped component to the proximity sensor 30, the overall structure tends to be bulky. In particular, compared with the dipole antenna 210, the monopole antenna 230 has a smaller diameter and a longer overall length. Therefore, during use, it is necessary to ensure a space so that the elongated rod-shaped antenna portion does not get damaged due to contact with other components.

[0095] When using the slot antenna 220, although its power reception efficiency is not as excellent as that of the monopole antenna 230, it has been found that much better power reception efficiency can be obtained compared with the shorter dipole antenna 210 (see Fig. 20). In the case of the slot antenna 220, compared with the dipole antenna 210 and the monopole antenna 230, since there is no need to project additional components from the housing 31 of the proximity sensor 30, it has the advantage of having the most compact overall structure without changing the size of the housing 31 of the conventional device 30.

[0096] Furthermore, referring to Fig. 31, a diagram is illustrated in which an inverted-F antenna 400 is provided as the power receiving device 20 on the housing 31 of the device (proximity sensor) 30. As shown in the figure, the inverted-F antenna 400 includes an elongated main body portion 410, a short circuit portion 420, and a power feeding portion 430. The long axis direction (X-axis direction) of the main body portion 410 is aligned with the long axis direction of the housing 31, suppressing the protrusion from the housing 31 due to the provision of the inverted-F antenna 400. The main body portion 410 can contribute to both matching and radiation (power reception). While a relatively large current flows through the tip of the main body portion 410 and the short circuit portion 420, the input impedance may be adjusted (for example, increased) by suppressing the current in the power feeding portion 430.

[0097] The inverted-F antenna 400 can be attached to the device 30 without requiring a large space. For example, the inverted-F antenna 400 can be configured to be shorter compared to a simple monopole antenna 230 (see FIGS. 18 and 19). Also, the inverted-F antenna 400 can more easily control impedance matching. Due to its configuration, the inverted-F antenna 400 has many adjustment parameters, and by selecting an appropriate shape, it can accommodate various specifications.

[0098] For example, the separation distance between the short-circuit portion 420 and the feeding portion 430 may be adjusted. Also, the widths and lengths of the short-circuit portion 420 and the feeding portion 430 may be adjusted. Also, the positions of the short-circuit portion 420 and the feeding portion 430 may be exchanged. That is, the short-circuit portion 430 and the feeding portion 420 may be used. Also, the main body portion 410 may be configured in a substantially rod shape (narrow width), and its length may be adjusted. A curved portion may be introduced into the main body portion 410. For example, the main body portion 410 may be configured in a substantially L shape. Also, the main body portion 410 may be configured in a substantially plate shape (wide width), and its length may be adjusted.

[0099] The power receiving device 20 can mainly have a slot antenna (see FIG. 17) that generates a magnetic field and an inverted-F antenna (see FIG. 31) that mainly generates an electric field. The slot antenna and the inverted-F antenna may be aligned in substantially the same direction with each other, and the slot antenna and the inverted-F antenna may form an omnidirectional non-directional antenna having radiation or power receiving patterns that are substantially orthogonal to each other.

[0100] Instead of the dipole antenna, slot antenna, monopole antenna, and inverted-F antenna illustrated in FIGS. 16 to 19 and FIG. 31, a planar or linear chip antenna can be similarly attached to the housing 31 of the device (not shown). For example, the linear chip antenna can be considered in the same way as the monopole antenna. Also, when attaching a dipole antenna, a monopole antenna, an inverted-F antenna 400, or a chip antenna to the housing 31 of the device, a cover 500 (see FIG. 31) that covers the elongated antenna portion may be used in combination. The cover 500 can have any size and shape so as to protect the antenna portion from contact with surrounding components and the like. The cover 500 may be configured to be detachable from the housing 31 so that it can be removed during use.

Embodiment

[0101] As described above, cases where a dipole antenna, a slot antenna, a monopole antenna, an inverted-F antenna, and / or a chip antenna are applied to the sensor have been exemplified. Next, a case where a slot antenna is applied to an actuator will be exemplified.

[0102] Referring to FIG. 21(A), an actuator is exemplified as the device 30 to be powered by the power receiving device 20. The actuator 300 is a mechanical element that constitutes a mechanical-electrical circuit that converts an electrical signal into physical movement. For example, the actuator 300 has a housing 310 that forms a substantially rectangular main body. The housing 310 extends in the longitudinal direction, defines a space therein, and houses the operating portion 350. The operating portion 350 performs operations such as expansion / contraction, bending, and turning by physical devices such as machines, oil / pneumatic, heat, and electromagnetism.

[0103] Referring to FIG. 21(B), a cross-sectional view of the actuator 300 is schematically shown. The operating portion 350 housed in the housing 310 is configured to project the moving portion 352 outward from the inside of the housing 310 with respect to the fixed portion 354 by acting electromagnetically based on an input signal. By the protruding / retracting operation of the moving portion 352, the movement of a proximity component (not shown) is controlled.

[0104] As illustrated in Fig. 21(A), the actuator 300 has a rectangular parallelepiped housing 310. This rectangular parallelepiped can additionally include further surfaces for design or functional purposes. For example, on the four side surfaces of the housing 310, mounting grooves 311 to 318 extending in the longitudinal direction are formed. These grooves 311 to 318 act in pairs with other convex parts (not shown) to fit the housing 310 and fix it in place, thereby preventing displacement in the operation of the operating part 350. Additionally, according to the embodiment, grooves or holes 321 to 324 can be appropriately formed on the side surfaces of the housing 310. Furthermore, it is optional to process the housing 310 for reasons such as surface treatment to release the heat inside the housing 310 to the outside or for design reasons.

[0105] Referring to Fig. 21(A), a first slot (cut) 330 is formed along the longitudinal direction on at least one of the four side surfaces around the housing 310. A space is defined inside the housing 310 to accommodate the operating part 350. In the depth direction, the first slot 330 penetrates the wall of the housing in the thickness direction and reaches the space. As a result, the first slot 330 can function as a first slot antenna.

[0106] Referring to the same figure, a second slot (cut) 340 is formed in a direction intersecting the longitudinal direction on at least one of the four side surfaces around the housing 310. In the depth direction, the second slot 340 penetrates the wall of the housing in the thickness direction and reaches the space. As a result, the second slot 340 can function as a second slot antenna. The second slot 340 may be provided as a perpendicular bisector to the first slot 330. Therefore, the first slot 330 and the second slot 340 intersect crosswise with each other. By providing these two slot antennas 330 and 340 in this way, it becomes stronger against rotation.

[0107] The length, position, and number of the first slot 330 and the second slot 340 are determined in consideration of the radiation pattern of electromagnetic waves. For example, referring to FIG. 21(A), the first slot 330 extends only on the upper side surface. The first slot 330 may further extend on four side surfaces, namely, the upper side surface, the right side surface, the left side surface (not shown), and the lower side surface. The number of the first slots 330 may be plural. Also, the second slot 340 extends on three side surfaces, namely, the upper side surface, the right side surface, and the left side surface (not shown). The second slot 340 may further extend on four side surfaces, namely, the upper side surface, the right side surface, the left side surface (not shown), and the lower side surface. The number of the second slots 340 may be plural.

[0108] The first slot 330 and the second slot 340 each extend straight parallel to the side surface of the housing 310. This makes the processing easier. However, in other embodiments, it is possible to extend at an angle with respect to the side surface of the housing 310 in consideration of functions, design purposes, etc. Also, the first slot 330 and the second slot 340 are not completely separated from each other and partially intersect. However, in other embodiments, the two slots 330 and 340 may be provided so as to be completely separated from each other. Preferably, however, the first slot 330 and the second slot 340 are orthogonal to each other at an angle of 90 degrees.

[0109] Referring to FIGS. 23(A) and (B), for the two different slot antennas 330 and 340 illustrated in FIG. 22(A), the electromagnetic field simulation results of the antenna directivity in three-dimensional space are shown. This simulation assumes that power is supplied by the reference signs E1 and E2 in FIG. 21. Each of the antennas 330 and 340 appears as omnidirectional. The directivities of the antennas 330 and 340 appear with different strengths from each other. Therefore, by combining and using these two antennas 330 and 340, their directivities can complement each other.

[0110] Referring to FIG. 23, simulation results of the radiation efficiency of the two different slot antennas 330 and 340 illustrated in FIG. 21 are shown. This simulation assumes that power feeding is performed with the reference signs E1 and E2 in FIG. 21. Generally, it has been verified that each of the antennas 330 and 340 has a high efficiency of 70 to 80%. For example, at a frequency of 0.92 GHz, high efficiencies of approximately 80% for E1 and approximately 75% for E2 are achieved.

[0111] Referring to FIG. 24, simulation results of the impedance characteristics of the actuator 300 illustrated in FIG. 21 are shown. Generally, it has been verified that good changes in impedance characteristics can be obtained by the power received by each of the antennas 330 and 340. For example, at a frequency of 0.92 GHz, the impedance is suppressed to a value close to 0 Ω.

[0112] Therefore, omnidirectional non - directive antennas 330 and 340 can be obtained only by performing cutting processing (such as making a cut) on the housing 310 of the conventional actuator 300. At this time, since no other parts are added and protruded with respect to the housing 310, the mounting space of the conventional actuator 300 is not changed. In particular, on the working surface side (operating portion 350) of the actuator, there is no change in the configuration. For this reason, it can be used almost in the same manner as the conventional actuator 300. However, in the embodiment illustrated in FIG. 21, it is further possible to add, in addition to the slot antennas 330 and 340, or instead of the slot antennas 330 and 340, a monopole antenna, a dipole antenna, a chip antenna, an inverted F antenna, etc. on the housing 310.

Embodiment

[0113] In the actuator 300 illustrated in FIGS. 21 to 24, slot antennas 330 and 340 are provided by forming slots on the housing 310. In the actuator 300 illustrated in FIGS. 25 to 30, it corresponds to a modified example of this slot antenna 330, 340.

[0114] Referring to FIG. 25, a perspective view of the actuator 300 is illustrated. Hereinafter, only the differences from the actuator 300 illustrated in FIG. 21(A) will be described. On the housing 310 of the actuator 300, a first slot antenna 330 and a second slot antenna 340 are formed, and on each of the slot antennas 330, 340, substrates 360, 370 of power receiving ICs for improving power receiving efficiency are respectively provided.

[0115] Referring to FIGS. 26(A) and 26(B), cross-sectional views of the front side and the side surface of the actuator 300 in FIG. 25 are schematically illustrated. As can be understood from these figures, bolts 361, 362 and a rectifier 363 are provided on the substrate 360. Similarly, bolts 371, 372 and a rectifier 373 are provided on the substrate 370. The rectifiers 363, 373 may be configured as a chip antenna integrated type.

[0116] In FIG. 26, the power supply substrates 360, 370 are provided, but actually, the slots 330, 340 of the housing 310 are antennas. By mounting a chip antenna, an inverted F antenna, a monopole antenna, a dipole antenna, etc. on these substrates 360, 370, respective patterns of an electric field and a magnetic field are generated to achieve 360° coverage. Therefore, the space required for adding an antenna is minimized to achieve space saving, and an omnidirectional non-directional antenna (360° power receiving) is achieved. Thereby, an antenna-less wireless power supply actuator 300 without an antenna protruding to the outside is configured.

[0117] On each of the substrates 360 and 370, two bolts 361, 362, 371, and 372 are provided respectively. Among these, on one substrate 360, the two bolts 361 and 362 are juxtaposed horizontally. On the other substrate 370, the two bolts 371 and 372 are juxtaposed vertically. Therefore, each set of bolts 361, 362 and 371, 372 through which current flows are arranged orthogonally to each other. Note that the number of bolts 361, 362, 371, and 372 on each of the substrates 360 and 370 may be two or more. These bolts have no surface coating, and conditions such as preventing the conductor from short-circuiting and ensuring that the screws do not loosen even against the intense movement of the robot may be added.

[0118] As described above, in each of the slot antennas 330 and 340, radiation occurs at the slot portion and is configured to function as an antenna. At this time, the bolts 361, 362, 371, and 372 on the substrates 360 and 370 function to allow current to flow. The rectifiers 363 and 373 are elements having a rectifying action that allows current to flow only in one direction, and convert the RF (electromagnetic wave) received by each antenna 330 and 340 into DC (direct current voltage). On these substrates 360 and 370, a chip antenna can be further provided integrally. Two bolts 361, 362, 371, and 372 are provided respectively on each of the substrates 360 and 370, but this number can be changed according to the embodiment.

[0119] The chip antenna includes a linear antenna such as a dipole antenna or a monopole antenna and a planar antenna. In this embodiment, a planar antenna is used. Since the chip antenna can be used as it is by utilizing the metal part of the housing 310 of the actuator 300, the area efficiency can be improved compared to a dipole antenna or a monopole antenna. In addition, various materials can be applied to the chip antenna, and for example, ceramics or the like may be used.

[0120] Referring to FIGS. 27(A) and (B), for the two different slot antennas 330 and 340 and substrates 360 and 370 illustrated in FIG. 25, the electromagnetic field simulation results of the antenna directivity in three-dimensional space are shown. Similar to FIGS. 22(A) and (B), each of the antennas 330 and 340 appears to be omnidirectional. The directivities of the respective antennas 330 and 340 appear with different strengths. Therefore, by using these two antennas 330 and 340 in combination, their directivities can complement each other.

[0121] Referring to FIG. 28, for the two different slot antennas 330 and 340 and substrates 360 and 370 illustrated in FIG. 25, the simulation results of the respective radiation efficiencies are shown. Similar to FIG. 23, generally, it has been verified that each of the antennas 330 and 340 has a high efficiency of nearly 70%. Note that FIG. 23 corresponds to ideal power supply, while FIG. 28 corresponds to a more realistic power supply. Therefore, in the case of FIG. 28, the efficiency is slightly lower compared to the case of FIG. 23.

[0122] Referring to FIG. 29, for the actuator 300 illustrated in FIG. 25, the simulation results of the impedance characteristics are shown. Generally, it has been verified that good changes in impedance characteristics can be obtained by the power received by each of the antennas 330 and 340 and substrates 360 and 370. For example, at a frequency of 0.92 GHz, the impedance is suppressed to a value close to 0 Ω.

[0123] Referring to FIG. 30, for the actuator 300 illustrated in FIG. 25, the simulation results of the surface current distribution are shown. Generally, it is shown that the current can be suitably distributed along the positions of the respective antennas 330 and 340. Therefore, it was confirmed that each of the antennas 330 and 340 can function well.

[0124] Referring to FIGS. 32(A) and 32(B), an example is shown in which a light-emitting diode (LED) 600 is attached to the main body 310 of the actuator 300. The LED 600 is connected to the output of the power receiving device via a switch (not shown). When the switch is turned on and a voltage exceeding a predetermined threshold flows through the LED 600, the lamp of the LED 600 is configured to light up. It is assumed that the lighting of the LED 600 can be visually confirmed from the outside of the actuator 300.

[0125] Therefore, based on the lighting of this LED 600, a user (for example, an inspector) can easily grasp the power receiving status of the power receiving device without performing an electrical inspection. The intensity of the light emitted by the LED 600 is approximately proportional to the amount of current flowing. In order to prevent waste of the available power in wireless power supply, it is preferable to minimize the lighting frequency or period of the LED 600. For example, the switch of the LED 600 may be turned on before or after the start of use of the power receiving device so as to minimize the influence on the power supply operation.

[0126] In addition, it is possible to attach an acoustic device (not shown) such as a buzzer instead of the LED 600 on the main body 310 of the actuator 300. Similarly, when a voltage exceeding a predetermined threshold flows through the buzzer, the buzzer can be configured to emit a sound. Therefore, based on the volume of this buzzer, a user (for example, an inspector) may easily grasp the power receiving status of the power receiving device without performing an electrical inspection.

Example

[0127] Referring to FIG. 33, an inverted F antenna 700 is provided on the housing 310 of the actuator 300. The housing 310 has a size in a three-dimensional space (X-axis, Y-axis, and Z-axis directions). By providing the power receiving device, the expansion of the size of the housing 310 in the three-dimensional space can be limited to a maximum of substantially one axial direction (Z-axis direction). Specifically, the housing 310 has a substantially hexahedral structure, and substrates 740 and 750 for mounting the inverted-F antenna 700 are provided on its upper surface. The sizes of the respective substrates 740 and 750 are made to be substantially equal to or only slightly expanded (in the X-axis and Y-axis directions) compared to the size of the upper surface (one side surface) of the housing 310. In particular, the back of the substrate 740 serves as a ground substrate, which is short-circuited with the housing 310 to effectively increase the ground size.

[0128] The inverted-F antenna 700 includes a substantially L-shaped main body 710, an elongated short-circuit portion 720, and a feeding portion 730. The inverted-F antenna 700 can be mounted on the housing 310 without requiring a large space. For example, the inverted-F antenna 700 can be configured to be shorter in the major axis direction (X-axis direction) compared to a simple monopole antenna 230 (see FIGS. 18 and 19). The major axis direction of the main body 710 is aligned with the major axis direction (X-axis direction) of the housing 310. However, the tip extends in the width direction (Y-axis direction). The size of the substantially L-shaped main body 710 in the width direction can be suppressed to be equal to or less than the size of the housing 310 in the width direction (Y-axis direction). Therefore, protrusion from the housing 310 due to the provision of the inverted-F antenna 700 is suppressed in the X-axis direction and the Y-axis direction. The main body 710 may be configured in a substantially L-shape having one curved portion, or may be configured in a straight line without a curved portion. Also, the number of curved portions may be increased.

[0129] The short-circuit portion 720 and the feeding portion 730 connect between the two substrates 740 and 750 in the vertical direction (Z-axis direction). The separation distance between the short-circuit portion 720 and the feeding portion 730, and their respective widths and lengths are adjustable. It is also possible to exchange the positions of the short-circuit portion 720 and the feeding portion 730. That is, it may be the feeding portion 720 and the short-circuit portion 730. The inverted-F antenna 400 can more easily control impedance matching. Due to its configuration, the inverted-F antenna 400 has many adjustment parameters, and thus can be adapted to various specifications by selecting an appropriate shape. The main body 710 can contribute to both matching and radiation (power reception).

[0130] Also in this case, the power receiving device 20 can have a slot antenna (see FIGS. 21 and 25) that mainly generates a magnetic field and an inverted-F antenna (see FIG. 33) that mainly generates an electric field. The slot antenna and the inverted-F antenna may be aligned in substantially the same direction with respect to each other, and the slot antenna and the inverted-F antenna may constitute an omnidirectional non-directional antenna having radiation or power receiving patterns that are substantially orthogonal to each other.

[0131] As described above, the present embodiment provides a housing 31, 310 that wirelessly receives energy and supplies power to devices 30, 300, and devices 30, 300 having the housing 31, 310, while suppressing an increase in size as a whole. The power receiving device 20 provided on the housings 31, 310 is configured to have at least one of a dipole antenna, a slot antenna, a monopole antenna, an inverted-F antenna, and a chip antenna (linear or planar).

[0132] Preferably, on the housings 31, 310, there is a power receiving device 20 having at least two of a monopole antenna, a dipole antenna, a slot antenna, an inverted-F antenna, and a chip antenna. Preferably, the two antennas of the power receiving device 20 have different antenna directivities, respectively. Preferably, the two antennas constitute an omnidirectional non-directional antenna having radiation or power receiving patterns that are substantially orthogonal to each other.

[0133] The power receiving device 20 is configured such that the portion protruding from the housings 31, 310 to the outside is limited in one axial direction in a three-dimensional space at most (see the X-axis direction in FIG. 8, the X-axis direction in FIG. 19, and the Z-axis direction in FIG. 33), or such that there is substantially no portion protruding from the housings 31, 310 to the outside (see FIGS. 21 and 25). Therefore, in practice, it can be used almost in the same manner as the existing device 30. Preferably, even when the power receiving device 20 has a portion protruding from the outside (refer to the X-axis direction in FIG. 8), the protruding direction is aligned with the previous wiring direction (refer to the wiring in FIG. 2(C)). Therefore, substantially, the usability of the previous device is not impaired. Preferably, when attaching the power receiving device 20 onto the casings 31, 310 of the device, it is made not to interfere with the working surface of the device (32 in FIG. 8, 350 in FIG. 21). Therefore, substantially, the usability of the previous device is not impaired.

[0134] In FIG. 33, when providing the reverse F antenna 700 upward (Z-axis direction) from the upper surface of the casing 310, a part of the substrate 740 protrudes in the direction perpendicular to the protruding direction (X-axis direction and / or Y-axis direction). However, as a whole, the protruding ratio of the substrate 740 (in the X-axis direction) is relatively small and can be ignored in practice. For example, if the protrusion is about less than 10% of the size of the upper surface of the casing 310, the size does not cause substantial damage and can be ignored. The important point is that even if there is a slight protrusion of the substrate 740 (in the X-axis direction), the protrusion ratio is suppressed. As a result, it does not affect the operation of the device 300 and does not expand the mounting space of the device 30.

[0135] The devices 30, 300 powered by the power receiving device 20 may be operated in a low power mode (a mode enabling operation with power consumption about one-fifth that of the existing operation method) as exemplified in FIG. 4, or may be operated in a normal power mode. Also, the devices 30, 300 may be operated with power consumption less than one-fifth and up to about one-fifth compared to the existing operation method.

[0136] The power receiving device 20 may be provided as a device that is a sensor or an actuator. For example, it may be provided as the sensor 30 exemplified in FIGS. 8, 16 to 18, or the actuator 300 exemplified in FIGS. 21 and 25. The power receiving device 20 may be provided as a housing of a device that is a sensor or an actuator. For example, this embodiment may be applied to an existing sensor or actuator by simply replacing its housing. For example, it may be provided as the housing 31 of the sensor 30 illustrated in FIGS. 8, 16 to 18, or the housing 310 of the actuator 300 illustrated in FIGS. 21 and 25.

[0137] Note that the housings 31 and 310 are defined as the housings that define the main body of the device. Although the above housings 31 and 310 completely accommodate the internal components (circuits, etc.) of the device, depending on the embodiment, it is not necessarily required to completely surround the internal components of the device, and it is possible to expose a part of them.

[0138] The power receiving device 20 may be provided as a part of the housing of a device that is a sensor or an actuator. For example, this embodiment may be applied to the housing of an existing sensor or actuator by simply replacing / attaching a part of it. It may be provided as the power supply connector 33 of the housing 31 of the sensor 30 illustrated in FIGS. 8, 16 to 18. That is, it may be provided as a wireless power supply connector 33 that is used by replacing the conventional wired power supply connector 33.

[0139] The power receiving device 20 may be provided as a system 1 that includes the device 30 to be powered and further other additional components (refer to the reference numerals 40, 50 in FIG. 1(A) / reference numeral 80 in FIG. 15). Furthermore, the power receiving device 20 may be provided as a machine 100 that incorporates a system 1 that includes the device 30 to be powered and further other additional components (refer to the reference numerals 40, 50 in FIG. 1(A) / reference numeral 80 in FIG. 15).

[0140] The power receiving device 20 may further be configured to adjust the power receiving status of the antenna according to the embodiment. For example, the protruding length of the dipole antenna 21 illustrated in FIG. 8 or the protruding length of the monopole antenna 230 illustrated in FIG. 18 may be made changeable. The dipole antenna 21 illustrated in FIG. 8, the monopole antenna 230 illustrated in FIG. 18, the linear chip antenna, etc. may be configured to be detachable, separable, telescopic, or foldable.

[0141] Also, for example, in the actuator 300 illustrated in FIG. 25, the bolts 361, 362, 371, 372 on the substrates 360, 370 function to conduct current, but their positions may be made adjustable. For example, the bolts 361, 362, 371, 372 are screwed into the holes formed in the substrates 360, 370, and their heights can be changed by adjusting the screwed state. The protruding heights of the bolts 361, 362, 371, 372 may be adjusted so as to obtain an optimal current value according to the power receiving status.

[0142] Furthermore, in the actuator 300 illustrated in FIG. 25, the depths, lengths, widths, and / or power feeding positions of the slots 330, 340 formed in the housing 310 may be made adjustable. For example, the slots 330, 340 recessed in the housing 310 can have their depths, lengths, widths, etc. changed by fitting appropriate members therein. The depths, lengths, widths, etc. of the slots 330, 340 may be adjusted so as to obtain an optimal power feeding position according to the power receiving status.

[0143] Furthermore, in the actuator 300 illustrated in FIG. 25, a power receiving IC may be placed on the substrates 360, 370 to make it possible to adjust the power receiving status of the antenna. The adjustment of the bolts 361, 362, 371, 372 and the slots 330, 340 may be performed manually or may be configured to be performed automatically.

[0144] Furthermore, in the actuator 300 illustrated in FIG. 25, when the rectifiers 363 and 373 are placed on the substrates 360 and 370, the rectifiers 363 and 373 themselves may have negative impedance. To avoid impedance mismatch, the power receiving IC may be configured to be able to search for a positive power supply position. The power receiving IC may avoid impedance mismatch without using an impedance matching circuit by determining a power supply position according to the power receiving situation.

[0145] Furthermore, in the present embodiment, the power receiving system 1 or the power receiving device 20 may include a CPU (processing device or processor) and a memory (storage device) to enable the above-described control for adjusting the power receiving situation of the antenna. The CPU is generally defined as a device that executes software (program). For example, the CPU is a Neumann type CPU. The CPU may include a control device for overall control, an arithmetic device, a register for temporarily storing data, an interface with the memory, and an interface with an input / output device for peripheral devices. The memory is defined as a device that can store data. For example, the memory is a primary storage device directly accessible by the CPU or a secondary storage device accessed using an input / output channel or the like. For example, the memory can use any medium, a fixed disk, a volatile or non-volatile random access memory, a CD, a DVD, a flash drive, a removable medium (e.g., a thumb-sized small memory) attached to a corresponding interface (e.g., a USB port), or the like.

[0146] Furthermore, in the present embodiment, the above-described power receiving system 1 or the power receiving device 20 may be provided as a computer program product for controlling the power receiving situation of the antenna. The computer program product may be implemented as a program or a function or a routine or an executable object. Therefore, it relates to a computer program product for performing the above-described control.

[0147] A computer program product such as computer program means can be implemented as a file downloadable from a memory card, a USB stick, a CD-ROM, a DVD, or a server in a network. For example, such a file may be provided by transferring a file including the computer program product from a wireless communication network.

[0148] A person skilled in the art could make various applications and modifications to the above embodiments without departing from the scope of the claims. For example, each part (component) of the power receiving device 20 or the power receiving system 1 can include other components necessary for its operation, and can further include additional components to provide functions other than those described in this specification. Therefore, it should be understood that the scope of the claims can be implemented in a manner different from that specifically described in this specification.

[0149] The above-described embodiments disclose at least the following configurations. (1) A housing constituting the main body of a device that is a sensor or an actuator, the housing mounts a power receiving device that mainly generates an electric field or a magnetic field for wireless power supply, the power receiving device is at least one of a dipole antenna, a slot antenna, a monopole antenna, a chip antenna, and an inverted F antenna, the housing has a size in three-dimensional space, and the expansion of the size of the housing in the three-dimensional space due to providing the power receiving device is limited to a maximum of substantially one axial direction. For example, the expansion of the size of the housing in the three-dimensional space due to the provision of the power receiving device is substantially limited to one axial direction (in the case of a dipole antenna, a monopole antenna, a linear chip antenna, and an inverted F antenna), or the expansion of the size of the housing in the three-dimensional space due to the provision of the power receiving device is substantially eliminated (in the case of a slot antenna and a planar chip antenna). In the latter case, since power can be received simply by providing a cut slot in the housing, an antenna-less wireless power supply device can be configured. Preferably, even if the size of the housing is expanded in one direction by providing the power receiving device, the ratio of the protrusion is suppressed. For example, it is set to be not more than twice, or not more than 1.5 times, etc. of the size of the housing in that direction. It is also possible to configure the antenna to be detachable, divisible, extendable or foldable. Therefore, the wireless devices 30 and 300 of the present proposal can be used in substantially the same manner as the conventional devices powered by wire, avoiding the expansion of the mounting space. (2) The power receiving device includes a slot antenna that mainly generates a magnetic field and a dipole antenna that mainly generates an electric field. The slot antenna and the dipole antenna are aligned substantially in the same direction with respect to each other. The slot antenna and the dipole antenna constitute an omnidirectional non-directional antenna having radiation or power reception patterns that are substantially orthogonal to each other (see FIGS. 8 and 9). (3) The power receiving device includes a slot antenna that mainly generates a magnetic field and a monopole antenna that mainly generates an electric field. The slot antenna and the monopole antenna are aligned substantially in the same direction with respect to each other. The slot antenna and the monopole antenna constitute an omnidirectional non-directional antenna having radiation or power reception patterns that are substantially orthogonal to each other (see FIGS. 17 and 18). (4) The power receiving device includes a first slot antenna that mainly generates a magnetic field and a second slot antenna that mainly generates a magnetic field. The first slot antenna and the second slot antenna are aligned in a direction substantially crossing each other. The first slot antenna and the second slot antenna constitute an omnidirectional non - directive antenna having radiation or power reception patterns substantially orthogonal to each other (see FIGS. 21 and 22). (5) The power receiving device has a slot antenna that mainly generates a magnetic field and an inverted F antenna that mainly generates an electric field. The slot antenna and the inverted F antenna are aligned in substantially the same direction as each other. The slot antenna and the inverted F antenna constitute an omnidirectional non - directive antenna having radiation or power reception patterns substantially orthogonal to each other (see FIGS. 8, 31, 21, and 33). (6) The power receiving device has a slot antenna that mainly generates a magnetic field and a chip antenna. The slot antenna and the chip antenna are aligned in substantially the same direction as each other. The slot antenna and the chip antenna constitute an omnidirectional non - directive antenna having radiation or power reception patterns substantially orthogonal to each other (see FIG. 25). (7) The power receiving device has at least two antennas among a dipole antenna, a slot antenna, a monopole antenna, a chip antenna, and an inverted F antenna, and the antennas are configured to have radiation or power reception patterns substantially different from each other. In particular, the two antennas 21 and 22 are configured to make the directivities of the respective antennas different and to complement each other in the regions where the directivities of both weaken. (8) The power receiving device is a slot antenna. Substantially eliminating the expansion of the size of the housing in the three - dimensional space due to the provision of the power receiving device. In particular, when providing a slot antenna on the housing, it is drilled along the long - axis direction of the housing so as to penetrate the wall of the housing in the thickness direction (see FIGS. 17, 21, and 25). (9) The housing can have a metal connector that enables wiring for wired power supply (see reference numeral 33 in FIGS. 8 and 2), and the power receiving device is attached to the connector. Therefore, by only replacing a part of the housing (see reference numeral 33 in FIGS. 8 and 2), wireless power supply is enabled and the existing housing can be utilized to the maximum extent. (10) The housing is provided with a chip antenna integrated with a rectifier (see FIGS. 25 and 26). (11) The housing is provided with the slot antenna and a bolt through which current flows therein (see FIGS. 25 and 26). (12) A device that is a sensor or an actuator, having the housing for the above device, performs wireless power supply based on the microwave method. (13) A system including a device that is a sensor or an actuator and a filter that receives the output of the device, wherein the device has the housing for the above device, the filter enables operation with power consumption about one-fifth that of the existing operation method of the sensor or the actuator. The device may enable operation with power in the range from less than or equal to one-first to about one-fifth compared with the existing operation method. The device can be driven by wireless power supply and also enables wireless data transmission to achieve complete wirelessization of the device.

Explanation of Reference Numerals

[0150] 1 System 10 Power Transmission Device 20 Power Receiving Device 21 Dipole Antenna 22 Slot Antenna 30 Device (Sensor) 31 Housing 33 Connector 210 Dipole Antenna 220 Slot Antenna 230 Monopole Antenna 300 Device (Actuator) 310 Housing 330 Slot Antenna 340 Slot Antenna 363 Rectifier (Chip Antenna Integrated Type) 373 Rectifier (Chip Antenna Integrated Type) 400 Inverted F Antenna 700 Inverted F Antenna

Claims

1. A sensor system, configured to be attachable to a metal housing that constitutes the body of a device that is an actuator, a power receiving device that mainly generates an electric field or a magnetic field for wireless power supply, and includes at least one of a dipole antenna, a slot antenna, a monopole antenna, a chip antenna, and an inverted F antenna; a sensor that operates with the power supplied from the power receiving device, measures a physical quantity with respect to an object, and generates information regarding the measurement result; a control unit that transmits a signal regarding the measurement result generated by the sensor by wireless communication; the metal housing has a size in a three-dimensional space, and the expansion of the size of the metal housing in the three-dimensional space due to the provision of the power receiving device is substantially limited in one axial direction; a circuit that suppresses impedance mismatch of the power receiving device caused by the metal housing receiving electromagnetic waves; A sensor system comprising.

2. The power receiving device has a slot antenna that mainly generates a magnetic field and a dipole antenna that mainly generates an electric field, the slot antenna and the dipole antenna are aligned in substantially the same direction as each other, the slot antenna and the dipole antenna constitute an antenna having radiation or power reception patterns that are substantially orthogonal to each other, the one axial direction in which the expansion is limited in the metal housing is orthogonal to the same direction; The sensor system according to claim 1.

3. The power receiving device has a slot antenna that mainly generates a magnetic field and a monopole antenna that mainly generates an electric field, the slot antenna and the monopole antenna are aligned in substantially the same direction as each other, the slot antenna and the monopole antenna constitute an antenna having radiation or power reception patterns that are substantially orthogonal to each other, the one axial direction in which the expansion is limited in the metal housing is orthogonal to the same direction; The sensor system according to claim 1.

4. The power receiving device has a first slot antenna that mainly generates a magnetic field and a second slot antenna that mainly generates a magnetic field, the first slot antenna and the second slot antenna are aligned in a substantially intersecting direction with each other, The first slot antenna and the second slot antenna constitute an antenna having radiation or power reception patterns that are substantially orthogonal to each other. The one axial direction in which expansion is limited in the metal housing is orthogonal to the extending direction of the first slot antenna. The sensor system according to claim 1.

5. The power receiving device includes a slot antenna that mainly generates a magnetic field and an inverted-F antenna that mainly generates an electric field. The slot antenna and the inverted-F antenna are aligned in substantially the same direction as each other. The slot antenna and the inverted-F antenna constitute an antenna having radiation or power reception patterns that are substantially orthogonal to each other. The sensor system according to claim 1.

6. The power receiving device includes a slot antenna that mainly generates a magnetic field and a chip antenna. The slot antenna and the chip antenna are aligned in substantially the same direction as each other. The slot antenna and the chip antenna constitute an omnidirectional non-directional antenna having radiation or power reception patterns that are substantially orthogonal to each other. The one axial direction in which expansion is limited in the metal housing is orthogonal to the same direction. The sensor system according to claim 1.

7. The power receiving device has at least two antennas among a dipole antenna, a slot antenna, a monopole antenna, a chip antenna, or an inverted-F antenna, and the antennas each have radiation or power reception patterns that are substantially different from each other. The sensor system according to claim 1.

8. The power receiving device includes a slot antenna. Substantially eliminating the expansion of the size of the housing in the three-dimensional space due to providing a slot antenna in the power receiving device. The sensor system according to claim 1.

9. The metal housing can have a metal connector that enables wiring for wired power supply, and the power receiving device is attached to the connector. The sensor system according to any one of claims 1 to 7.

10. The housing includes a chip antenna integrated with a rectifier. The sensor system according to any one of claims 1 to 9.

11. The housing includes the slot antenna and a bolt through which current flows. The sensor system according to any one of claims 1 to 10.

12. The sensor system according to any one of claims 1 to 11, wherein the power receiving device performs wireless power supply based on a microwave method, and the sensor system. **Claim 13**: The sensor system according to claim 1, wherein the circuit searches for a power supply position according to a power receiving situation in consideration of the electromagnetic wave received by the metal housing. **Claim 14**: The sensor system according to claim 1 or 13, wherein the circuit suppresses impedance mismatch by searching for a power supply position. **Claim 15**: The power receiving device of the sensor system according to any one of claims 1 to 14 receives an electromagnetic wave for generating power to be supplied to at least one of the sensor or the actuator by using the metal housing as an antenna. **Claim 16**: The metal housing has a plurality of recesses, The sensor system according to any one of claims 1 to 15, wherein the power receiving device receives an electromagnetic wave for generating power by using the plurality of recesses of the metal housing as an antenna. **Claim 17**: The object is the actuator, and the sensor measures a physical quantity changed by the actuator. The sensor system according to any one of claims 1 to 16. **Claim 18**: The sensor system according to any one of claims 1 to 17, wherein the power receiving device further includes a substrate to which an antenna for receiving the electromagnetic wave for generating power is attached. **Claim 19**: The sensor system according to claim 18, wherein the substrate is shorted to the metal housing of the actuator.

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