Sensor systems, FA systems, and actuator systems

Abstract

To provide a housing for wirelessly receiving energy so as to inhibit the size from expanding as a whole while securing preferable power reception efficiency to supply power to a device and the device including the housing.SOLUTION: A body of a device 30, which is a sensor or an actuator, includes a housing 31. A power reception device for mainly generating an electric field or a magnetic field for wireless power feeding is attached to the housing 31. The power reception device is at least one of a dipole antenna 21, a slot antenna 22, a monopole antenna, a chip antenna, and an inverse F antenna. The housing 31 has the size in a three-dimensional space, where expansion of the size of the housing 31 in the three-dimensional space caused by provision of the power reception device is substantially limited in a one axial direction (X axial direction).SELECTED DRAWING: Figure 8

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), the Internet of Things (IoT), and home appliances, various sensors and actuators are used. Generally, in many cases, the power wiring of sensors and actuators has not been made wireless.

[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 power wirelessly, there are problems such as a decrease in power reception efficiency compared to the case of cable wiring. Also, 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 in this technical field, there is Japanese Patent Application Laid-Open No. 2014-7629 (Patent Document). This document 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. Also, 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 describes a proximity sensor equipped 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 helical antenna 2 do not receive the energy necessary for the operation of the proximity sensor. Furthermore, the loop antenna 1 and helical antenna 2 may significantly increase the overall size of the proximity sensor (see Figures 1 and 6). This may reduce the usability of the proximity sensor. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Japanese Patent Publication No. 2014-7629 [Overview of the project] [Problems that the invention aims to solve]

[0008] The problem we are trying to solve is to ensure good power reception efficiency while 、 It wirelessly receives energy and uses it to power devices. Sensor system The objective is to provide. [Means for solving the problem]

[0009] To solve the above problems, for example, adopt the configuration described in the claims. 。 [Effects of the Invention]

[0010] According to the present invention, while ensuring good power reception efficiency, 、 It wirelessly receives energy and uses it to power devices. Sensor system We can provide this. Other issues, configurations, and effects not mentioned above will be clarified by the following description of the embodiments. [Brief explanation of the drawing]

[0011] [Figure 1]FIG. 1 is an example of a diagram showing an embodiment of a power receiving device that wirelessly receives energy from a power transmission device, divided into (A) and (B). [Figure 2] FIG. 2 is an example of a diagram illustrating a conventional proximity sensor. [Figure 3] FIG. 3 is an example of a diagram illustrating the change in output when the voltage of the proximity sensor is lowered. [Figure 4] FIG. 4 is an example of a diagram illustrating the change in output when the voltage of the proximity sensor is lowered. [Figure 5] FIG. 5 is an example of a diagram illustrating a power receiving device. [Figure 6] FIG. 15 is an example of a diagram showing a modified example of the power receiving system. [Figure 7] FIG. 7 is an example of a diagram graphically showing the efficiencies of two different types of antennas. [Figure 8] FIG. 8 is an example of a perspective view of a proximity sensor provided with two different types of antennas. [Figure 9] FIG. 9 is an example of a diagram illustrating the radiation of two different types of antennas in a three-dimensional space.​​​​​​​​​​​​​​​​​​​​​​​​ [Figure 18] Figure 18 is an example of a diagram illustrating a change in the power receiving equipment. [Figure 19] This is an example of a diagram comparing the conventional sensor shown in Figure 2 with the modified example shown in Figure 18. [Figure 20] Figure 20 is an example of a graph showing the efficiency of three different types of antennas. [Figure 21] Figure 21 is an example diagram illustrating an actuator equipped with two different antennas. [Figure 22] Figure 22 is an example of a diagram illustrating the radiation from two different antennas in three-dimensional space. [Figure 23] Figure 23 is an example of a graph showing the efficiency of two different antennas. [Figure 24] Figure 24 is an example of a diagram illustrating the impedance change caused by the power receiving device in Figure 20. [Figure 25] Figure 25 is an example of a perspective view of an actuator with two different antennas and bolts. [Figure 26] Figure 26 is an example of a diagram illustrating the front view and perspective view of Figure 25. [Figure 27] Figure 27 is an example of a diagram illustrating the radiation from two different antennas in three-dimensional space. [Figure 28] Figure 28 is an example of a graph showing the efficiency of two different antennas. [Figure 29] Figure 29 is an example of a diagram illustrating the impedance change caused by the power receiving device shown in Figure 21. [Figure 30] Figure 30 is an example of a simulation diagram of the power receiving status of the power receiving device shown in Figure 25. [Figure 31] Figure 31 shows an example of a device housing with an inverted F antenna. [Figure 32] Figure 32 shows an example of an actuator housing with an LED installed. [Figure 33] Figure 33 shows an example of a device housing with an inverted F antenna. [Modes for carrying out the invention]

[0012] Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. Note that the embodiments described below are just one example of the present invention, and the content of the present invention should not be interpreted as being limited based on the following description. [Examples]

[0013] "Overall configuration of the power receiving device" Referring to Figure 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 energy E from the power transmitting device 10 wirelessly and supplies power to the device 30. Therefore, the power receiving device 20 completely eliminates the need to wire physical cables for power supply between itself and the power transmitting device 10. Furthermore, the power receiving device 20 is integrated with the device 30 to be powered. Therefore, the power receiving device 20 completely eliminates the need to wire physical cables for power supply between it and the device 30. As illustrated in Figure 1(B), the power receiving system 1 may include other components 30, 40.

[0014] The power receiving device 20 is defined as a device that can receive wirelessly transmitted energy E and supply power to the device 30. The power transmission device 10, which acts in conjunction with the power receiving device 20, is defined as a device capable of wirelessly transmitting energy E. Device 30 is a device that receives the energy necessary for its operation from the power receiving device 20. In particular, device 30 is a sensor or an actuator. A sensor is defined as an electronic device that measures a physical quantity and generates the result of that measurement. An 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, MR sensor, Hall element, displacement sensor, inspection sensor, discrimination sensor, measurement sensor, length measuring sensor, vibration sensor, microphotosensor, pressure sensor, flow sensor, temperature and humidity sensor, human presence sensor, wear sensor, acceleration sensor, strain sensor, force sensor, CMOS sensor, photoelectric sensor, laser sensor, ultrasonic sensor, touch sensor, linear cage, potentiometer, image sensor, color sensor, LiDAR sensor, TOF sensor, seismic sensor, gyro sensor, tilt sensor, rotation sensor, angle sensor, tachometer, load cell, false sensor, torque sensor, liquid level sensor, leak / water detection sensor, non-contact temperature sensor, current sensor, power sensor, electrostatic sensor, or isolator, etc. Furthermore, the actuator may be an electric actuator, a hydraulic actuator, a pneumatic actuator, a chemical actuator, a magnetic fluid actuator, an electroviscous fluid actuator, or the like.

[0016] The power receiving system 1, which includes at least the power receiving device 20 and the device 30, is applicable to a variety of applications, such as factories (FA: Factory Automation), the Internet of Things (IoT), and home appliances. In the example shown in Figure 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] Machine 100 can be configured for various applications, such as gripping, lifting (picking), placing, assembling, painting, and welding workpieces or parts W. For example, machine 100 is a highly articulated robot capable of performing highly flexible movements. However, the power receiving system 1 can be applied to various applications other than the illustrated machine 100. For example, the power receiving system 1 may be installed in general FA equipment to supply power to sensors that detect objects on a factory line, such as proximity sensors and magnetic sensors. Furthermore, the power receiving system 1 may be installed in general building management to monitor the conditions of the office environment, such as temperature, humidity, and illuminance sensors. The following is an example of a power receiving system 1 built into the articulated robot 100.

[0018] The articulated robot 100 generally has multiple (at least two) axes or joints J1a, J1b, J2a, J2b, J2c to allow the robot arm 110 and / or robot hand 120 to operate with a high degree of freedom. Generally, the more joints J1a, J1b, J2a, J2b, J2c an articulated robot 100 has, the greater the degree of freedom of movement it can perform, but the more precise the control required. On the other hand, the fewer joints J1a, J1b, J2a, J2b, J2c an articulated robot 100 has, the simpler the mechanism becomes and the less prone to malfunctions it is.

[0019] Referring to Figure 2(C), an example of the wiring state of a conventional sensor 30 is shown. As shown in the figure, there were physical constraints when wiring the sensor 30 within the machine 100 to supply power to the sensor 30. For example, the movement of the joints J1a, J1b, J2a, J2b, and J2c of the articulated robot 100 caused problems such as stress on the wiring of the sensor 30 (see Figure 2), wire breakage, or maintenance of the wiring. In addition, in machines that perform highly flexible movements, such as articulated robots 100, various components such as actuators are generally incorporated inside, which limits the space available for wiring. Furthermore, there was a risk of wire breakage if the wiring was corroded by oil or other substances. In this embodiment, the above-mentioned wiring problem is avoided.

[0020] The power receiving system 1 can be applied to various machines 100 in any manner. For example, the power receiving system 1 does not need to house all its components within the fingers of the robot hand 120 as illustrated in Figure 1(A). In this case, relatively large and bulky parts may be made flexible and rolled up and stored within the finger space. Also, some parts may be placed in locations away from the fingers (for example, at the base of the fingers of the robot hand 120 or in a wider area nearby). Furthermore, some parts can protrude outside the machine 100 as needed.

[0021] Referring to Figure 1(A), the power transmission device 10 is positioned at a suitable location outside the articulated 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 transfer, but in this embodiment, a microwave method is preferably used to wirelessly transfer power between the power transmission device 10 and the power receiving device 20. The microwave method allows for the transmission of energy E or power over relatively long distances. The following example illustrates a proximity sensor as a specific example of device 30.

[0022] "Proximity sensor" Referring to Figures 2(A) and (B), an aspect view and a side view of the conventional proximity sensor 30 are shown as examples. A proximity sensor 30 is a device used to detect an object without making contact with it. Various types of proximity sensors 30 are known; for example, some react when metal approaches. Because proximity sensors 30 are non-contact, they do not deteriorate due to wear and tear, and they have advantages such as being waterproof, dustproof, and durable. In particular, the type that reacts to metal has the advantage of being less affected by dust and water droplets, resulting in fewer false detections. Proximity sensors 30 come in various detection distances; for example, some can detect objects in millimeters. Specifically, proximity sensors 30 include inductive proximity sensors, capacitive proximity sensors, and magnetic proximity sensors.

[0023] Inductive proximity sensors primarily detect conductors made of metals such as iron, aluminum, brass, and copper. Their principle involves detecting magnetic loss caused by eddy currents generated on the surface of a conductor due to the influence of an external magnetic field. For example, an alternating magnetic field is generated in the detection coil, and the change in impedance caused by eddy currents in the metal object being detected is detected.

[0024] Capacitive proximity sensors primarily detect metals, resins, liquids, powders, etc. (depending on their dielectric constant). Their principle involves detecting changes in capacitance between the object being detected and the sensor. For example, when a metal or dielectric approaches, the capacitance between the sensor's internal electrodes and the ground potential increases due to electrostatic induction. This change in electrode capacitance increases the oscillation amplitude, detecting the approach of the object.

[0025] Magnetic proximity sensors primarily detect magnets. Their principle involves using a magnet to activate a switch's lead. For example, they are configured so that turning on a reed switch activates the sensor.

[0026] Referring to Figure 2(A), an inductive proximity sensor 30 is illustrated, which houses a detection coil (not shown), an oscillation circuit, an oscillation state detection circuit, and an output circuit within a housing 31 that constitutes the main body. A detection surface 32 is provided on one end of the housing 31, which allows the high-frequency magnetic field emitted from the detection coil based on the oscillation circuit to be emitted. When a metal object (see W in Figure 1) approaches this high-frequency magnetic field, an induced current flows in the nearby metal due to electromagnetic induction, causing heat loss within the metal object W. When this condition occurs, the oscillation state detection circuit detects the attenuation or cessation of the oscillation and outputs the result to the outside via the output circuit.

[0027] The proximity sensor 30 needs to be powered in order to perform the detection operation described above and generate an electrical signal. Typically, the proximity sensor 30 has a wiring connector (mounting part) 33 on the end of the housing 31 opposite to the detection surface 32. This connector 33 is usually made of metal and has a power receiving cable connected to it (see Figure 2(B)). 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 are not limited to this configuration. The housing 31 can be configured in various ways. For example, to fix the detection surface 32 in a predetermined position during use and prevent fluctuations in the detection distance, the housing 31 may have an enlarged diameter section that can be tightened and fixed (see reference numerals 34, 35, 36). For example, the enlarged diameter section may be equipped with nuts 34, 35 and washers 36 to allow the housing 31 to be tightened and fixed. Therefore, the housing 31 can be separated into two parts at this enlarged diameter section.

[0028] "Wireless" The proximity sensor 30 needs to be installed in close proximity to the object in order to detect it. Generally, when the proximity sensor 30 is installed near the object to be detected (workpiece W), there is a possibility that the proximity sensor 30 may collide with the workpiece W. In such cases, damage to the proximity sensor 30 may occur. For this reason, the proximity sensor 30 is said to be replaced relatively frequently. 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: cable installation and cable routing (see Figure 2(C)). Generally, the proximity sensor 30 is available in various cable lengths such as 2m, 5m, and 10m, and each cable needs to be installed on the controller or other equipment according to the specific setup. The above steps incur labor costs for factory workers. Some companies estimate the hourly wage of workers at 4,000 yen and the loss of 3 million yen per minute of line downtime.

[0030] In this embodiment, the above problems are addressed by using a microwave system to receive energy E from the power transmission device 10, which is then used by the power receiving device 20 to power the proximity sensor 30. However, the microwave system has an upper limit on the amount of energy E that can be transmitted. Furthermore, there is a problem that the energy reception efficiency is lower compared to the wired system. In addition, the amount of power that can be supplied from the power transmission device 10 to the power receiving device 20 decreases inversely proportional to the square of the distance, according to Friis's law.

[0031] Generally, proximity sensors 30 operate at 12 to 24V and 3 to 1000mA. In other words, they require a minimum power consumption of about 36mW. However, in microwave wireless power transfer, it may only be possible to supply about 1 to 10mW of power to a power source 1m away. Therefore, reducing the power consumption of proximity sensors 30 is one of the challenges in wirelessly powering them.

[0032] The above-mentioned issue of "reducing the power consumption of proximity sensors" could potentially be resolved by developing a new proximity sensor 30 specifically designed for low power consumption and specific applications. However, generally, developing a new product requires a period of approximately one to five years. Therefore, in the manufacturing industry, it is common practice to repurpose products designed for consumer electronics for automotive applications. In this case, the required development period can sometimes be shortened to about one year. In this embodiment, it is assumed that the development of a new low-power proximity sensor will be unnecessary by using an existing proximity sensor 30 that supports 12 to 24V as is. Therefore, the applicant conducted the following tests.

[0033] First, the applicant conducted tests to verify how an existing proximity sensor 30 compatible with 12 to 24V operates when powered at a level lower than the recommended value. Referring to Figure 3(A), the power consumption of two different commercially available proximity sensors (a, b) compatible with 12 to 24V is shown in response to changes in power supply voltage when a voltage lower than the recommended value is supplied. In this figure, the horizontal axis of the graph shows the supply voltage (V), and the vertical axis shows the power (mW). When the supply voltage was gradually reduced to approximately 6V for existing proximity sensors compatible with 12 to 24V, it was verified that the proximity sensors operated as specified. Normally, when an object is detected, the output of the proximity sensor goes low. In this case, the power consumption decreases as the power supply voltage is lowered. However, it was confirmed that a power consumption of approximately 30mW still occurred.

[0034] Referring to Figure 3(B), following Figure 3(A), it shows the power consumption of the proximity sensor when the power supply voltage is further reduced. As shown in the figure, when the voltage is reduced to about 5.2V, the power consumption is about 6mW. In other words, it was confirmed that the proximity sensor 30 can be operated with a power supply of about 10mW. Thus, it was verified that existing proximity sensors compatible with 12 to 24V can still meet power requirements even when the supply voltage is significantly reduced from the recommended value. In this case, the need to research and develop new proximity sensors compatible with 5 to 6V can be avoided. However, it was confirmed that the proximity sensor behaves differently under these low power conditions compared to normal operation (when operating at the recommended 12 to 24V).

[0035] Referring to Figure 4(A), as shown in Figure 3(B), the output waveform of the proximity sensor 30 is shown when the power supply voltage is significantly reduced from the recommended value (to 6V or less). As can be seen from the figure, the output voltage appears positive when there is no object nearby (see V0), but when an object is detected, the output voltage appears significantly negative (see V1). Under normal operating conditions, the proximity sensor maintains a reduced output voltage state when an object is detected ("object detection = low output"). However, as shown in Figure 3(B), when a voltage significantly lower than the recommended value is supplied, the above "object detection = low output" is not satisfied throughout the entire time domain, and intermittent operation was observed. In other words, it was confirmed that the proximity sensor periodically outputs a positive (see V0) and a negative (see V1) output voltage alternately, even though object detection is ongoing. The period of this intermittent operation is T period Therefore, when an object is detected, the downward output voltage waveform has a period T. period It was confirmed that it appears every time.

[0036] Furthermore, the applicant conducted tests to confirm the regularity of the intermittent operation of this proximity sensor. Referring to Figure 4(B), a graph is shown in the case of Figure 4(A) above, with the supply voltage (V) on the horizontal axis and time (msec) on the vertical axis. As a result, the period of the intermittent operation exemplified in Figure 4(A) is T period It was found that there is a relationship as shown in the graph in Figure 4(B). That is, for one type of proximity sensor (a), as the supply voltage is further reduced from 6V, the period T of the intermittent operation described above period It was found that the magnitude increased almost proportionally. This was confirmed to be true for other types of proximity sensors (b) as well. Thus, a relationship was found between the intermittent operation of the proximity sensor and its periodic fluctuations.

[0037] In the following, a state in which the proximity sensor exhibits intermittent operation due to the proximity sensor's power supply voltage being considerably lower than the recommended value will be referred to as the low-power mode (a mode that enables operation with approximately one-fifth the power consumption compared to the existing operating method). Conversely, a state in which the proximity sensor's power supply voltage meets the recommended value and the proximity sensor does not exhibit intermittent operation will be referred to as the normal power mode. Note that the low-power mode may include modes that enable operation with power consumption ranging from less than one-tenth to approximately one-fifth of the existing operating method.

[0038] In low-power mode, the proximity sensor 30 exhibits intermittent operation (see Figure 4(A)), so directly using its output presents problems. In this embodiment, in such cases, it is possible to differentiate 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 (object is replaced) and a state where an object is present by using circuit design. That is, the period T of intermittent operation period As illustrated in Figure 4(A), these occurrences occur at relatively short time intervals. The magnitude of these time intervals is approximately proportional to the power supply voltage, as illustrated in Figure 4(B), and can therefore be estimated based on the power supply voltage. Thus, by utilizing the ability to predict the intermittent operation of the proximity sensor based on the power supply voltage, it is possible to determine whether or not the proximity sensor is detecting an object.

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

[0040] Therefore, in the power receiving system 1, even when the conventional proximity sensor 30, which typically operates at 12 to 24V, is operated in low-power mode (approximately 5 to 6V), misrecognition of the sensor output can be avoided. However, the power receiving system 1 is not limited to the configuration shown in Figure 1(B). The power receiving system 1 is applicable to various types of devices (sensors or actuators) 30, and depending on the type of device 30, the device 30 may be operated in normal power mode as well as low power mode. Therefore, the power receiving system 1 does not necessarily have to include a periodic filter 40.

[0041] "Receiving antenna" Next, the power receiving device 20 used in the power receiving system 1 illustrated in Figures 1 to 4 will be described. In this embodiment, the power receiving device 20 is configured as a power receiving antenna. In particular, since the power receiving antenna is configured using the housing 31 (see Figure 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] Figures 5 to 7 provide a schematic example of the overall configuration of the power receiving device 20. Figure 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. Normally, the proximity sensor 30 has a metal body or housing 31, but the area around the dipole antenna 21 must not be metal and must be made of resin or something similar (non-metallic).

[0043] Figure 5(B) illustrates a case 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 drilled through its wall to function as an antenna that generates magnetic field radiation.

[0044] Figure 5(C) illustrates a case where the dipole antenna 21 and slot antenna 22 are used as a power receiving device 20. In this case, the dipole antenna 21 and slot antenna 22 are arranged in a straight line continuously in the longitudinal direction. These two antennas 21 and 22 together have a total length of approximately 300 mm.

[0045] The dipole antenna 21 and slot antenna 22 shown in Figure 5(C) are positioned aligned in the same direction. However, the directions of action of both antennas appear to be perpendicular to each other. This is because the dipole antenna 21 operates mainly based on an electric field, while the slot antenna 22 operates mainly based on a magnetic field, so their directions of action intersect.

[0046] Referring to Figure 6, the results of a simulation of the power receiving status of each antenna in three-dimensional space for the power receiving device 20 exemplified in Figure 5(C) are shown. Figure 6(A) schematically shows the directivity of the dipole antenna 21. Figure 6(B) schematically shows the directivity of the slot antenna 22. In these figures, the darker the color, the stronger the directivity of each antenna. As can be seen from these figures, by combining two different types of antennas 21 and 22 to configure the power receiving device 20, it is possible to configure an omnidirectional antenna as a whole.

[0047] For example, in the X-axis direction of Figure 6(A), the dipole antenna 21 has a region where its directivity is weakened, as shown by reference numeral 21A. In contrast, in the X-axis direction of Figure 6(B), the slot antenna 22 has a region where its directivity is strengthened, as shown by reference numeral 21B. Since these regions 21A and 21B overlap, in the X-axis direction, the reduced functionality of the dipole antenna 21 can be compensated for by the functionality of the slot antenna 22.

[0048] Furthermore, in the Y-axis direction of Figure 6(A), the dipole antenna 21 has a region where its directivity is strengthened, as indicated by the reference numeral 22A. In contrast, in the Y-axis direction of Figure 6(B), the slot antenna 22 has a region where its directivity is weakened, as indicated by the reference numeral 22B. Since these regions 22A and 22B overlap, in the Y-axis direction, the reduced functionality of the slot antenna 22 can be compensated for by the functionality of the dipole antenna 21.

[0049] Furthermore, in the Z-axis direction of Figure 6(A), the dipole antenna 21 has a region where its directivity is strengthened, as indicated by the reference numeral 23A. In contrast, in the Z-axis direction of Figure 6(B), the slot antenna 22 has a region where its directivity is weakened, as indicated by the reference numeral 23B. Since these regions 23A and 23B overlap, in the Z-axis direction, the reduced functionality of the slot antenna 22 can be compensated for by the functionality of the dipole antenna 21.

[0050] Thus, the directivity of the dipole antenna 21 and the slot antenna 22 does not appear uniformly in three-dimensional space, but rather with varying strengths, although their distributions differ. By combining these two, the slot antenna 22 can compensate for the region where the directivity of the dipole antenna 21 is weaker, and vice versa. Therefore, the two antennas 21 and 22 are configured to complement each other's directivity. As a result, the combination of antennas 21 and 22 as a whole is configured to receive power in almost all directions without any particular gaps in directivity. This configuration can be achieved simply by arranging the two antennas 21 and 22 in a straight line relative to each other, as illustrated in Figure 5(C), and does not require complex adjustment of the orientations of both antennas.

[0051] Referring to Figure 7, the simulation results for the dipole antenna 21 and slot antenna 22 described above are shown, with frequency (GHz) on the horizontal axis and antenna efficiency (ideally 100%) on the vertical axis. As can be seen from the figure, it was verified that when the frequency is varied from 0.8 to 1.0 GHz, each antenna can exhibit a high efficiency of over approximately 99%. Therefore, it was confirmed that the power receiving device 20 shown in Figures 5(A) to (C) can receive power effectively.

[0052] Next, with reference to Figures 8 to 10, we will explain specific implementation examples of the power receiving device 20, which is schematically illustrated in Figures 5 to 7. Referring to Figure 8, a perspective view of a proximity sensor 30 integrated with the power receiving device 20 according to this embodiment is shown. This figure corresponds to an implementation example when the dipole antenna 21 and slot antenna 22 exemplified in Figure 5(C) are combined.

[0053] As illustrated in Figure 5(A), a dipole antenna 21 is provided at the end of the metal housing 31 of the proximity sensor 30 as the power receiving device 20. Normally, the proximity sensor 30 has a metal connector 33 for wired power supply (see Figure 2), but the dipole antenna 21 may also be attached to this part. The dipole antenna 21 has a rod-shaped body and extends linearly along the longitudinal direction of the housing 31. In the previous proximity sensor 30, a wiring cable was extended from the end of the housing 31 opposite the detection surface 32 (see Figure 2(C)). In this embodiment, such a cable is unnecessary, and the freed-up space is used to attach a dipole antenna 21 to the end of the housing 31. In this case, the metal of the conventional connector 33 of the proximity sensor is used as the antenna's GND. Therefore, the dipole antenna 21 may be provided on the housing 31 by replacing the conventional connector 33.

[0054] As illustrated in Figure 5(B), the power receiving device 20 has a slot antenna 22 provided by drilling a vertically elongated slot along the longitudinal direction in the metal housing 31 of the proximity sensor 30. This slot penetrates the wall of the housing 31 in the thickness direction. 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). Furthermore, when drilling slots in the housing 31, it is possible to cover the internal coils and circuits with metal or resin to protect them from oil ingress. Furthermore, if the housing 31 is made of a non-metallic material, it is possible to make it function as a slot antenna 22 by attaching a metal film to a slot that penetrates the wall of the housing 31 or by adding a metal component.

[0055] As illustrated in Figure 5(C), the dipole antenna 21 and the slot antenna 22 are arranged linearly and continuously 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 height does not cause any particular disadvantage to the directivity of each antenna. Thus, the housing 31 has size in three-dimensional space (X-axis, Y-axis, and Z-axis direction), and the expansion of the housing 31's size in three-dimensional space due to the installation of the power receiving devices 21 and 22 is limited to a maximum of substantially one axis direction (X-axis direction). In particular, in the case of the slot antenna 22, the expansion of the housing 31's size can be completely eliminated.

[0056] Therefore, in this 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 any direction. Each antenna 21, 22 may be functionally connected to a rectifier within the housing 31. A rectifier is an element that has a rectifying effect that causes current to flow in only one direction, and converts RF (electromagnetic waves) received by each antenna 21, 22 into DC (direct current voltage). The antennas 21, 22 and the rectifier may be configured as an integral part. As will be described later, the rectifier may also be integrated with a chip antenna. In this way, the antennas 21, 22 may rectify and convert microwaves into direct current.

[0057] When the proximity sensor 30 is used in factory automation (FA) machinery 100, oil resistance is required. If oil is used near or inside / outside the machinery 100, the housing 31 of the proximity sensor 30 may come into contact with the oil, causing corrosion. For this reason, the material of the housing 31 of the proximity sensor 30 is selected with oil resistance in mind. In this embodiment, considering the problems specific to FA, an antenna (dipole antenna 21 and slot antenna 22) may be incorporated inside the housing 31 of the proximity sensor 30. In this case, by utilizing the metal of the housing 31 to position the antenna, it may be possible to obtain advantages specific to microwave wireless power transfer in energy harvesting.

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

[0059] As can be seen from Figure 9, similar to the case shown in Figure 6, the region where the directivity of the slot antenna 22 weakens can be compensated for by the region where the directivity of the dipole antenna 21 strengthens. Conversely, the region where the directivity of the dipole antenna 21 weakens can be compensated for by the region where the directivity of the slot antenna 22 strengthens. Therefore, the two antennas 21 and 22, which are of different types, are configured to complement each other's regions where the directivity of each is weakened. As a result, these antennas 21 and 22 can receive power in almost all directions without showing any particular gaps in directivity.

[0060] The above describes a simulation-based verification of an omnidirectional antenna usable for factory applications, utilizing the radiation characteristics of a dipole antenna 21 and a slot antenna 22. The results confirmed that even though antennas 21 and 22 are aligned in the same direction (the longitudinal direction of the proximity sensor), radiation patterns are formed that are perpendicular to each other at 90-degree angles. Therefore, this embodiment constructs an omnidirectional antenna that utilizes the shape of the existing sensor 30.

[0061] Referring to Figure 10, the simulation results for the power receiving device 20 exemplified in Figure 8 are shown, with frequency (GHz) on the horizontal axis and the efficiency of each antenna 21 and 22 (ideally 100%) on the vertical axis. As can be seen from the figure, it was verified that when the frequency is varied from 0.8 to 1.0 GHz, the dipole antenna 21 can exhibit a high efficiency of approximately 99%, and the slot antenna 22 can exhibit a high efficiency of approximately 86%. Therefore, it was verified that the configuration using the slot antenna 21 and dipole antenna 22 exemplified in Figure 8 in combination is particularly suitable.

[0062] The above describes a power receiving device 20 having antennas 21 and 22, which is constructed using the same shape as the housing 31 of an existing proximity sensor 30. Please understand that the application of this power receiving device 20 is not limited to proximity sensors, but can be applied to other types of devices (sensors or actuators) 30. Furthermore, as illustrated in Figures 5(A) and (B), it is also possible to provide only one of these antennas 21 or 22 in the implementation example in Figure 8.

[0063] As is known to those skilled in the art, when energy E is transmitted wirelessly between a power transmission device 10 and a power receiving device 20, the power receiving efficiency of the power receiving device 20 decreases compared to the wired case. For example, in the wireless case, power reception may be as low as 0.4% at a distance of 1 meter in open space. Next, with reference to Figures 11 to 14, means for improving the power receiving efficiency of the power receiving device 20 during use will be described.

[0064] Referring to Figure 11(B), an example is shown in which a power transmission device 10 and a power receiving device 20 are housed at a distance from each other within a chamber (box) 90 that defines a rectangular enclosed space inside. The chamber 90 improves the efficiency of wirelessly transmitting energy E between the two by enclosing the power transmission device 10 and the power receiving device 20 within a defined closed space inside. Although not shown in the figure, it is possible to house all or part of the machine 100 illustrated in Figure 1 within this chamber 90.

[0065] In Figure 11 (B), the chamber 90 has a rectangular or polygonal shape, but this shape can be changed in various ways depending on the embodiment. For example, the corners do not need to be right angles and can be chamfered or otherwise processed. Therefore, the number of sides of the chamber 90 is not limited to six. Also, the shape of each side of the chamber 90 is not limited to a rectangle.

[0066] Referring to Figure 11(C), we see the results of a simulation of the movement of electromagnetic waves inside chamber 90, as illustrated in Figure 11(B). Figure 11(A) illustrates the situation at that time. As shown in Figure 11(C), the electromagnetic waves transmitted within the chamber 90 are reflected by each side that defines the boundary of the chamber 90. Ultimately, these electromagnetic waves are reflected countless times within the enclosed space, and the energy is confined within the chamber 90. As a result, the power receiving device 20 can receive energy from the power transmitting device 10 from various directions. Therefore, compared to the case where energy is received from only one direction without using the chamber 90 (see symbol E in Figure 1(A)), the power receiving device 20 can receive energy from multiple directions.

[0067] Referring to Figure 12, the simulation results for Chamber 90, exemplified in Figure 11, are shown with frequency (GHz) on the horizontal axis and the efficiency of each antenna (dB) on the vertical axis. In this simulation, five parameters (see S1,1, S3,1, S2,2, S3,2, and S3,3 in Figure 14) are used, and the magnitude is shown in dB. From these simulation results, it was confirmed that at least a 5-fold performance improvement can be obtained within Chamber 90, and generally, an improvement of approximately 6-fold performance can be obtained.

[0068] By using the chamber 90, energy can be contained within it, but in this embodiment, a means for concentrating the energy in the power receiving device 20 can also be provided. Referring to Figures 13(A) and (B), an example is shown in which a stirring fan 91 is installed on the ceiling of the chamber 90 as an electromagnetic wave reflecting means. The stirring fan 91 is configured such that a pair of reflective surfaces 93 and 94 rotate in a fan-like or propeller-like manner around a rotation axis 92. The pair of reflective surfaces 93 and 94 each extend in opposite directions along their longitudinal direction, and as a whole extend in a linear manner. However, the number, size, shape, angle, etc. of the reflective surfaces 93 and 94 can be varied in various ways depending on the embodiment.

[0069] As illustrated in Figure 13(A), the stirring fan 91 can send energy downward again by reflecting the electromagnetic waves that have escaped upward from the bottom of the chamber 90 to the ceiling off the surfaces of the reflective surfaces 93 and 94. Therefore, the power receiving device 20 can receive energy reflected from the stirring fan 91 in addition to the energy sent directly from the power transmitting device 10 and the energy sent by reflecting off the walls of the chamber 90.

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

[0071] For example, as shown in Figure 13(A), when the pair of reflective surfaces 93 and 94 extend almost straight along the longitudinal direction of the chamber 90, the energy escaping upward from the power transmission device 10 can be reflected and transmitted further in the longitudinal direction (vertical direction). Therefore, this is suitable when the straight-line propagation of energy is required during power transmission. Furthermore, as shown in Figure 13(B), if the pair of reflective surfaces 93 and 94 extend in a substantially intersecting direction along the longitudinal direction of the chamber 90, the energy escaping upward from the power transmission device 10 can be reflected and transmitted in a direction intersecting the longitudinal direction (lateral direction). Furthermore, the pair of reflective surfaces 93 and 94 can rotate around the central axis of rotation 92, allowing for various adjustments to the position and direction of energy reflection.

[0072] Referring to Figures 13(A) and (B), a fixed reflective surface 95 can also be installed on the side surface of the chamber 90. As described above, each side of the chamber 90 reflects electromagnetic waves. The reflective surface 95 can reflect electromagnetic waves with a different reflectivity than the sides of the chamber 90. By changing the reflection efficiency on each side of the chamber 90, the electromagnetic waves reflected within the chamber 90 may be directed more intensively towards the power receiving device 20. For example, the reflective surface 95 may be configured as a metasurface. In this way, reflected waves can be used to maximize the received power of the receiver in medium- and long-range wireless power transfer.

[0073] Referring to Figure 14, an example is shown in which a metasurface 96 is provided on the side surface of the machine 100 as a fixed reflective surface. In the FA robot 100 (see Figure 1), the robot arm 110, robot hand 120, and the main body of the robot 100 are made of metal, resulting in a large number of reflected waves. Therefore, as illustrated in Figure 14(A), these reflected waves can be used to reflect electromagnetic waves towards the power receiving device 20.

[0074] As illustrated in Figure 14(B), a metasurface 96 may also be provided on the side of the machine 100 to further concentrate and reflect electromagnetic waves toward the power receiving device 20. As illustrated in Figure 14(C), the metasurface 96 is constructed by arranging a plurality of small elements 98 on a substrate 97. The shape and arrangement of each element 98 are determined to obtain a suitable reflection efficiency. As a result, the metasurface 96 can reflect electromagnetic waves and concentrate them toward the power receiving device 20. This makes it possible to send energy from the power transmitting device 10 toward the power receiving device 20 more efficiently.

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

[0076] Referring to Figure 15, an example of a modification of the power receiving system 1 exemplified in Figure 1(B) is shown. The system 1 shown in the figure includes a power receiving device 20 that wirelessly receives energy from a power transmitting device 10, a device (proximity sensor) 30 powered by the power receiving device 20, a device (periodic filter) 40 that adjusts the output of the device 30, and a controller 50. The proximity sensor 30 recognizes the position of object W by a change in the magnetic field and generates a signal; however, in 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 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 microcontroller and wireless communication capabilities, and 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 machine 100, or it may be any other machine.

[0077] Here, enabling device 30 to be powered by wireless power supply means that if its data transmission is also made wireless, then the device 30 can be made completely wireless. For example, as illustrated in Figure 3(B) and Figure 4(B), the proximity sensor 30 is expected to be driven with approximately 6mW, and its data transmission is expected to be driven with approximately 1mW. Therefore, if the power receiving device 20 can supply approximately 7mW of energy to the proximity sensor 30, complete wireless operation of the proximity sensor 30 can be achieved. In microwave wireless power supply, it is possible to supply up to approximately 10mW of power to a power source 1m away, making complete wireless operation of the proximity sensor 30 possible. This also applies to sensors and actuators other than the proximity sensor 30.

[0078] As illustrated in Figure 1(B), the power receiving device 20 may supply power only to the device 30. Alternatively, as illustrated in Figure 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, other power sources can be added to the power receiving system 1. For example, as illustrated in Figure 15, it is possible to combine the proximity sensor 30 with a vibration power generation element 80 in order to ensure a minimum power supply voltage for the proximity sensor 30.

[0079] Various modifications can be made to the power receiving system 1 illustrated in Figure 1(B) and Figure 15. In the latter figure, a periodic filter 40 is included to achieve completely wireless proximity sensor 30 without requiring the development of a new proximity sensor, but this element can be omitted depending on the device being powered. Furthermore, as illustrated in Figure 4(B), for example, the filter constants depend on the power supply voltage of the proximity sensor 30 (approximately equal to the received power). Therefore, the power receiving system 1 illustrated in Figure 1(B) and Figure 15 may be extended to feed forward this information to the periodic filter 40 and the controller 50. [Examples]

[0080] As described above, Figures 5 to 10 show that 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, with reference to Figures 16 to 20, other embodiments of the power receiving device 20 illustrated in Figures 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 tip antenna, and an inverted F antenna.

[0081] Referring to Figure 16(A), an example perspective view is shown in which a short dipole antenna 210 is provided as a 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 desirable to extend the dipole antenna 210 so that it protrudes significantly from the housing 31. Therefore, in the embodiment shown in Figure 16(A), the dipole antenna 210 is provided with a relatively short length so as to limit the portion that protrudes 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 shown in Figure 16(A), a difference from the embodiment illustrated in Figure 8 is that a slot antenna is not provided on the housing 31. Therefore, the housing 31 is configured to be completely sealed, and when applied to the machine 100 in FA, etc., it completely prevents surrounding oil, etc., from entering the housing 31.

[0083] Referring to Figure 16(B), we see the simulation results of the power reception situation for the shorter dipole antenna 210 exemplified in Figure 16(A). As can be seen from this figure, it was found that even when the length of the dipole antenna 210 is kept relatively short, the same antenna directivity as in the case exemplified in Figure 9(A) can be secured.

[0084] Referring to Figure 17(A), a perspective view is shown illustrating a slot antenna 220 being drilled into the housing 31 of the proximity sensor 30 as a power receiving device 20. The area colored black corresponds to the dipole antenna 210 in Figure 16(A), allowing for a comparison of the positions and sizes of both antennas. As is well known to those skilled in the art, the housing 31 of the proximity sensor 30 can be configured in various ways depending on the manufacturer. In this embodiment, the housing 31 of an existing proximity sensor 30 may be used as is and the slot antenna 220 may be drilled into it, or a new housing 31 with a slot may be designed.

[0085] For example, in the embodiment illustrated in Figure 8, if there is a step in the housing 31 (see reference numeral 38 in Figure 8), the length of the slot that can be drilled horizontally on the housing 31 may be limited. In the embodiment shown in Figure 17(A), a difference from the embodiment illustrated in Figure 8 is that a relatively large housing 31 is provided so that the housing 31 extends straight horizontally, eliminating the step (see reference numeral 38 in Figure 8) and allowing for the drilling of a sufficiently long slot. For example, a slot of any length up to approximately 70%, 80%, 90%, or 100% of the total length of the housing 31 in the longitudinal direction (from the end on the 34 side to the end on the 33 side of the main body 31) may be drilled. Furthermore, when drilling slots in the housing 31, it is possible to cover the internal coils and circuits with metal or resin to protect them from oil ingress.

[0086] Referring to Figure 17(B), we see the simulation results of the power reception status of the slot antenna 220 exemplified in Figure 17(A). As can be seen from this figure, it was found that even when the length of the slot antenna 220 is increased, the same antenna directivity as in the example in Figure 9(B) can be ensured. Comparing Figure 16(B) and Figure 17(B), it was confirmed that the directivity of the dipole antenna 210 and the directivity of the slot antenna 220 intersect. This is similar to the cases illustrated in Figures 6(A) and (B), and Figures 9(A) and (B).

[0087] Referring to Figure 18(A), a perspective view is shown illustrating a monopole antenna 230 as a power receiving device 20 mounted on the housing 31 of the proximity sensor 30. The area colored black corresponds to the dipole antenna 210 in Figure 16(A), allowing for a comparison of the positions and sizes of both antennas. The monopole antenna 230 is also called a rod antenna, and compared to the dipole antenna 210, it has an even smaller diameter and is more elongated. In order to ensure the power receiving efficiency of the monopole antenna 230, it is necessary to ensure its length. For this reason, in this embodiment, one end of the monopole antenna 230 is attached to the housing 31 in close proximity to the nuts 34, 35 and washers 36 used to fasten and secure the housing 31, while the other end extends straight in the opposite direction. By aligning the extension direction of the housing 31 with the extension direction of the monopole antenna 230, the overall size is kept from becoming bulky.

[0088] Referring to Figure 18(B), the simulation results of the power reception status of the monopole antenna 230 exemplified in Figure 18(A) are shown. Comparing Figure 16(B) and Figure 18(B), it was confirmed that the directivity 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. Furthermore, comparing Figure 17(B) and Figure 18(B), it was confirmed that the directivity of the monopole antenna 230 and the slot antenna 220 intersect with each other.

[0089] Referring to Figure 19, a size comparison is shown between the conventional proximity sensor 30 exemplified in Figure 2(B) and the monopole antenna 230 exemplified in Figure 18(A). As shown in Figure 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 an enlarged diameter portion for tightening and fixing (see reference numerals 34, 35, and 36) on one end and a connector 33 on the other end.

[0090] As shown in Figure 19(A), the monopole antenna 230 is provided close to the enlarged diameter portion for tightening and fixing, and extends along the longitudinal direction of the housing 31 toward the other end 33 in the same direction (parallel to the longitudinal direction of the housing 31). As a result, the length L1 of the elongated monopole antenna 230 can be immersed within the longitudinal length L0 of the housing 31 by the length L2 from the enlarged diameter portion for tightening and fixing to the end 33 opposite to the housing 31. As a result, the expansion L3 in one axial direction in three-dimensional space due to the addition of the monopole antenna 230 to the housing 31 can be limited to a maximum of twice the longitudinal length L0 of the housing. In some embodiments, this expansion L3 in one axial direction in three-dimensional space may be limited to a maximum of 1.5 times the longitudinal length L0 of the housing. Alternatively, by making L1 foldable, the length of L3 may be reduced to substantially zero.

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

[0092] Referring to Figure 20, the antenna reception efficiency is shown for each of the three types of modification examples illustrated in Figures 16 to 19. As can be seen from the figure, it was found that the reception efficiency was the lowest when only the relatively short dipole antenna 210 was used. Furthermore, when the slot antenna 220 was added, although it did not reach 90%, it exceeded 80%, achieving a relatively good reception efficiency. Moreover, it was found that when the monopole antenna 230 was used, the reception efficiency was greatly increased, showing an ideal value close to 100%.

[0093] When the proximity sensor 30 is installed on a movable part such as the robot hand 120, the position and direction of the power receiving antenna change in various ways. In order to maintain good power supply conditions for the proximity sensor 30 in three-dimensional space, it is desirable that the power receiving device 20 maintain good power receiving efficiency in each of the six directions (front, back, left, right, up, and down) in three-dimensional space. When using only the short 210mm dipole antenna, it was found that good reception efficiency could only be achieved at relatively small angles of rotation. However, overall, it could exhibit relatively good stability in all six directions.

[0094] The monopole antenna 230 can achieve the best power reception efficiency (see Figure 20). However, because a long, slender rod-shaped component needs to be attached to the proximity sensor 30, the overall structure tends to be bulky. In particular, the monopole antenna 230 has a smaller diameter and a longer overall length compared to the dipole antenna 210. Therefore, when using it, it is necessary to ensure sufficient space to prevent the long, slender rod-shaped antenna from coming into contact with other components and causing damage.

[0095] When using the slot antenna 220, although its power reception efficiency is not as good as that of the monopole antenna 230, it was found to be far better than that of the shorter dipole antenna 210 (see Figure 20). In the case of the slot antenna 220, compared to the dipole antenna 210 and the monopole antenna 230, there is no need to protrude additional parts from the housing 31 of the proximity sensor 30, resulting in the most compact overall structure and the advantage of not changing the size of the housing 31 of the conventional device 30.

[0096] Furthermore, referring to Figure 31, an example is shown in which an inverted-F antenna 400 is provided as a 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 a long, slender main body 410, a short-circuit section 420, and a feed section 430. The long axis direction (X-axis direction) of the main body 410 is aligned with the long axis direction of the housing 31, thereby suppressing protrusion from the housing 31 due to the provision of the inverted-F antenna 400. The main body 410 can contribute to both matching and radiation (power reception). The input impedance may be adjusted (for example, by increasing it) by flowing a relatively large current through the tip of the main body 410 and the short-circuit section 420, while suppressing the current in the feed section 430.

[0097] The inverted F antenna 400 can be mounted on device 30 without requiring a large space. For example, the inverted F antenna 400 can be configured to be shorter than a simple monopole antenna 230 (see Figures 18 and 19). Furthermore, impedance matching control is easier with the inverted F antenna 400. Due to its configuration, the inverted F antenna 400 has many adjustment parameters, allowing it to accommodate various specifications by selecting the appropriate shape.

[0098] For example, the distance between the short-circuit section 420 and the power supply section 430 may be adjusted. Furthermore, the width and length of the short-circuit section 420 and the power supply section 430 may be adjusted. Alternatively, the positions of the short-circuit section 420 and the power supply section 430 may be swapped. That is, the short-circuit section 430 and the power supply section 420 may be swapped. Furthermore, the main body 410 may be configured in a roughly rod-like shape (narrow in width), and its length may be adjusted. A curved section may also be introduced into the main body 410. For example, the main body 410 may be configured in a roughly L-shape. Furthermore, the main body 410 may be configured in a roughly plate-like (wide) shape, and its length may be adjusted.

[0099] The power receiving device 20 may have a slot antenna (see Figure 17) that mainly generates a magnetic field and an inverted F antenna (see Figure 31) that mainly generates an electric field. The slot antenna and the inverted F antenna may be aligned substantially in the same direction, and the slot antenna and the inverted F antenna may constitute an omnidirectional antenna having substantially orthogonal radiation or power receiving patterns.

[0100] Instead of the dipole antenna, slot antenna, monopole antenna, and inverted F antenna illustrated in Figures 16 to 19 and Figure 31, planar or linear chip antennas can be similarly mounted on the device housing 31 (not shown). For example, a linear chip antenna can be considered similarly to a monopole antenna. Furthermore, when a dipole antenna, monopole antenna, inverted-F antenna 400, or chip antenna is attached to the device housing 31, a cover 500 (see Figure 31) that covers the elongated antenna portion may also be used. The cover 500 can have any size and shape to protect the antenna portion from contact with surrounding components, etc. The cover 500 may be configured to be detachably attached to the housing 31 so that it can be removed when in use. [Examples]

[0101] The above examples illustrate the application of dipole antennas, slot antennas, monopole antennas, inverted-F antennas, and / or chip antennas to sensors. Next, we will illustrate the case where a slot antenna is applied to an actuator.

[0102] Referring to Figure 21(A), an actuator is exemplified as the device 30 to which the power receiving device 20 is supplied. The actuator 300 is a mechanical element that constitutes a mechanical-electrical circuit that converts electrical signals into physical motion. For example, the actuator 300 has a housing 310 that forms a roughly rectangular body. The housing 310 extends in the longitudinal direction and defines space within it to house the movable part 350. The movable part 350 performs movements such as extension, bending, and rotation by physical devices such as machinery, hydraulics / pneumatics, heat, and electromagnetics.

[0103] Referring to Figure 21(B), a schematic cross-sectional view of the actuator 300 is shown. The movable part 350, housed within the housing 310, is configured to act electromagnetically based on an input signal, causing the movable part 352 to protrude from the inside of the housing 310 relative to the fixed part 354. The protrusion and retraction of this movable part 352 controls the movement of nearby components (not shown).

[0104] As illustrated in Figure 21(A), the actuator 300 has a rectangular parallelepiped housing 310. This rectangular parallelepiped may include additional faces for aesthetic or functional purposes. For example, mounting grooves 311 to 318 extending in the longitudinal direction are provided on four sides of the housing 310. These grooves 311 to 318 work in conjunction with other protrusions (not shown) to fit the housing 310 into place and fix it in a predetermined position. This prevents misalignment in the operation of the movable part 350. Depending on the embodiment, grooves or holes 321 to 324 may be provided on the sides of the housing 310 as appropriate. Furthermore, it is optional to process the housing 310 for surface treatment to dissipate heat from inside the housing 310, or for design reasons.

[0105] Referring to Figure 21(A), a first slot (notch) 330 is made on at least one of the four sides of the housing 310, extending along the longitudinal direction. A space is defined inside the housing 310 to accommodate the moving part 350. The first slot 330 penetrates the housing wall in the thickness direction in the depth direction to reach the space. As a result, the first slot 330 can function as a first slot antenna.

[0106] Referring to the figure, a second slot (notch) 340 is made on at least one of the four sides surrounding the housing 310, in a direction intersecting the longitudinal direction. 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. Thus, the first slot 330 and the second slot 340 intersect each other in a cross shape. By providing these two slot antennas 330 and 340, the antenna becomes more resistant to rotation.

[0107] The length, position, and number of the first slot 330 and the second slot 340 are determined by considering the electromagnetic wave radiation pattern. For example, referring to Figure 21(A), the first slot 330 extends only on the upper side. The first slot 330 may further extend on four other sides: the upper side, the right side, the left side (not shown), and the lower side. There may be multiple first slots 330. Furthermore, the second slot 340 extends over three sides: the upper side, the right side, and the left side (not shown). The second slot 340 may further extend over four sides: the upper side, the right side, the left side (not shown), and the lower side. There may be multiple second slots 340.

[0108] The first slot 330 and the second slot 340 each extend straight parallel to the side of the housing 310. This facilitates manufacturing. However, in other embodiments, it is possible to extend them at an angle to the side of the housing 310, taking into consideration functional or design purposes. Furthermore, the first slot 330 and the second slot 340 are not completely separate from each other, but intersect in part. However, in other embodiments, the two slots 330 and 340 may be provided so as to be completely separate from each other. However, preferably, the first slot 330 and the second slot 340 are perpendicular to each other at a 90-degree angle.

[0109] Referring to Figures 23(A) and (B), the electromagnetic field simulation results of the antenna directivity in three-dimensional space are shown for two different slot antennas 330 and 340 exemplified in Figure 22(A). This simulation assumes that power is supplied at the E1 and E2 symbols in Figure 21. Both antennas 330 and 340 appear as omnidirectional. The directivity of each antenna 330 and 340 appears with a difference in strength from one another. Therefore, by using these two antennas 330 and 340 in combination, their directivity can be complemented by each other.

[0110] Referring to Figure 23, the simulation results of the radiation efficiency for two different slot antennas 330 and 340 exemplified in Figure 21 are shown. This simulation assumes that power is supplied at the E1 and E2 markings in Figure 21. In general, each antenna 330 and 340 was verified to have a high efficiency of 70 to 80%. For example, at a frequency of 0.92 GHz, E1 achieves an efficiency of approximately 80%, and E2 achieves an efficiency of approximately 75%.

[0111] Referring to Figure 24, the simulation results of the impedance characteristics for the actuator 300 exemplified in Figure 21 are shown. In general, it was verified that a good change in impedance characteristics can be obtained depending on the power received by each antenna 330 and 340. For example, at a frequency of 0.92 GHz, the impedance is kept close to 0 Ω.

[0112] Therefore, omnidirectional antennas 330 and 340 can be obtained simply by machining (such as making cuts) the housing 310 of the conventional actuator 300. In this case, since no other parts are added to the housing 310 and do not protrude, the mounting space of the conventional actuator 300 does not change. In particular, there are no structural changes on the working surface (movable part 350) side of the actuator. For this reason, it can be used in almost the same way as the conventional actuator 300. However, in the embodiment illustrated in Figure 21, it is possible to add monopole antennas, dipole antennas, tip antennas, inverted-F antennas, etc., to the housing 310 in addition to, or in place of, the slot antennas 330 and 340. [Examples]

[0113] In the actuator 300 illustrated in Figures 21 to 24, slot antennas 330 and 340 are provided by drilling slots in the housing 310. The actuator 300 illustrated in Figures 25 to 30 corresponds to this modified example of the slot antennas 330 and 340.

[0114] Referring to Figure 25, a perspective view of the actuator 300 is shown as an example. Below, only the differences from the actuator 300 shown in Figure 21(A) will be explained. A first slot antenna 330 and a second slot antenna 340 are drilled into the housing 310 of the actuator 300, and furthermore, power receiving IC boards 360 and 370 are provided on each slot antenna 330 and 340, respectively, to improve power receiving efficiency.

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

[0116] In Figure 26, power supply boards 360 and 370 are shown, but in reality, slots 330 and 340 of the housing 310 are the antennas. By mounting chip antennas, inverted-F antennas, monopole antennas, dipole antennas, etc., on these boards 360 and 370, electric and magnetic field patterns are generated, achieving 360° coverage. Therefore, the space required for adding antennas is minimized, achieving space saving, while also achieving an omnidirectional antenna (360° power reception). This results in an antenna-less wireless power supply actuator 300 with no externally protruding antennas.

[0117] Each of the substrates 360 and 370 is provided with two bolts 361, 362, 371, and 372, respectively. On one substrate 360, the two bolts 361 and 362 are arranged side by side horizontally. On the other substrate 370, the two bolts 371 and 372 are arranged side by side vertically. Therefore, each pair of bolts 361, 362 and 371, 372 that carry current are arranged orthogonally to each other. Note that the number of bolts 361, 362, 371, and 372 on each substrate 360 ​​and 370 may be more than two. Additional conditions may be added, such as these bolts having no surface coating, preventing short circuits between conductors, and ensuring that the screws do not loosen even under violent robotic movements.

[0118] As described above, each slot antenna 330, 340 is configured to function as an antenna by radiating radiation in the slot portion. At that time, the voltages 361, 362, 371, and 372 on the substrates 360, 370 function to conduct current. The rectifiers 363 and 373 are elements that have a rectifying effect that allows current to flow in only one direction, and convert the RF (electromagnetic waves) received by each antenna 330, 340 into DC (direct current voltage). Chip antennas can also be integrated into these substrates 360 and 370. Each substrate 360, 370 has two voltages 361, 362, 371, and 372, but this number can be changed depending on the embodiment.

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

[0120] Referring to Figures 27(A) and (B), the electromagnetic field simulation results of the antenna directivity in three-dimensional space are shown for two different slot antennas 330 and 340 and substrates 360 and 370 as exemplified in Figure 25. Similar to Figures 22(A) and (B), each antenna 330 and 340 appears as omnidirectional. The directivity of each antenna 330 and 340 appears with a difference in strength from one another. Therefore, by using these two antennas 330 and 340 in combination, their directivity can be complemented by each other.

[0121] Referring to Figure 28, the simulation results of the radiation efficiency for the two different slot antennas 330 and 340 and substrates 360 and 370 exemplified in Figure 25 are shown. Similar to Figure 23, it was verified that each antenna 330 and 340 generally has a high efficiency of nearly 70%. Note that while Figure 23 corresponds to an ideal feed, Figure 28 corresponds to a more realistic feed, so the efficiency in Figure 28 is slightly lower compared to Figure 23.

[0122] Referring to Figure 29, the simulation results of the impedance characteristics for the actuator 300 exemplified in Figure 25 are shown. In general, it was verified that good changes in impedance characteristics can be obtained depending on the power received by each antenna 330, 340 and substrate 360, 370. For example, at a frequency of 0.92 GHz, the impedance is kept close to 0 Ω.

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

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

[0125] Therefore, based on the illumination of the LED 600, a user (e.g., an inspector) can easily understand the power reception status of the power receiving device without performing an electrical inspection. The intensity of the light emitted by the LED 600 is roughly proportional to the amount of current flowing. To prevent wasting of available power in wireless power transfer, it is preferable to minimize the frequency or duration of illumination of the LED 600. For example, the switch on the LED 600 may be turned on before or after the power receiving device is put into use, in order to minimize any impact on the power supply operation.

[0126] Alternatively, an acoustic device such as a buzzer (not shown) can be mounted on the main body 310 of the actuator 300 in place of the LED 600. Similarly, the buzzer can be configured to emit a sound when a voltage exceeding a predetermined threshold flows through it. Therefore, based on the volume of this buzzer, a user (e.g., an inspector) can easily ascertain the power supply status of the power receiving device without performing an electrical inspection. [Examples]

[0127] Referring to Figure 33, the inverted F antenna 700 is mounted on the housing 310 of the actuator 300. The housing 310 has dimensions in three-dimensional space (X-axis, Y-axis, and Z-axis directions). The expansion of the housing 310's dimensions in three-dimensional space due to the installation of the power receiving device is limited to a maximum of substantially one axis direction (Z-axis direction). Specifically, the enclosure 310 has a roughly hexahedral structure, and has circuit boards 740 and 750 on its upper surface to which the inverted-F antenna 700 is attached. The size of each circuit board 740 and 750 is approximately equal to, or only slightly smaller than, the size of the upper surface (one side) of the enclosure 310 (in the X and Y axes). In particular, the back of circuit board 740 is a ground board, which is short-circuited to the enclosure 310, effectively increasing the ground size.

[0128] The inverted F antenna 700 includes a roughly L-shaped main body 710, a long, narrow short-circuit section 720, and a feed section 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 made shorter in the long axis direction (X axis direction) compared to a simple monopole antenna 230 (see Figures 18 and 19). The long axis direction of the main body 710 is aligned with the long axis direction (X axis direction) of the housing 310. However, the tip extends in the width direction (Y axis direction). The width of the roughly L-shaped main body 710 can be kept below the width of the housing 310 (Y axis direction). Therefore, the protrusion from the housing 310 due to the inverted F antenna 700 is suppressed in the X axis direction and Y axis direction. The main body 710 may be configured as a straight line without a curved section, in addition to being roughly L-shaped with one curved section. The number of curved sections may also be increased.

[0129] The short-circuit section 720 and the feed section 730 connect the two substrates 740 and 750 vertically (in the Z-axis direction). The distance between the short-circuit section 720 and the feed section 730, as well as their respective widths and lengths, are adjustable. The positions of the short-circuit section 720 and the feed section 730 can also be swapped; that is, they can be the feed section 720 and the short-circuit section 730. The inverted F antenna 400 makes impedance matching control easier. Due to its configuration, the inverted F antenna 400 has many adjustment parameters, so by selecting an appropriate shape, it can accommodate various specifications. The main body section 710 can contribute to both matching and radiation (reception).

[0130] In this case as well, the power receiving device 20 may have a slot antenna (see Figures 21 and 25) that mainly generates a magnetic field and an inverted F antenna (see Figure 33) that mainly generates an electric field. The slot antenna and the inverted F antenna may be aligned substantially in the same direction, and the slot antenna and the inverted F antenna may constitute an omnidirectional antenna having substantially orthogonal radiation or power receiving patterns.

[0131] In summary, this embodiment provides housings 31 and 310 that wirelessly receive energy and supply power to devices 30 and 300, while keeping the overall size increase to a minimum, and devices 30 and 300 having the housings 31 and 310. The power receiving device 20, which is mounted on the housings 31 and 310, is configured to have at least one of the following: a dipole antenna, a slot antenna, a monopole antenna, an inverted F antenna, and a tip antenna (linear or planar).

[0132] Preferably, the housings 31, 310 have a power receiving device 20 having at least two of the following: a monopole antenna, a dipole antenna, a slot antenna, an inverted F antenna, and a tip antenna. Preferably, the two antennas of the power receiving device 20 have different directivity characteristics. Preferably, the two antennas constitute an omnidirectional antenna having substantially orthogonal radiation or power receiving patterns to each other.

[0133] The power receiving device 20 is configured such that the portion protruding from the housing 31, 310 is limited to a maximum of one axis in three-dimensional space (see the X-axis direction in Figure 8, the X-axis direction in Figure 19, and the Z-axis direction in Figure 33), or there is virtually no portion protruding from the housing 31, 310 (see Figures 21 and 25). Therefore, in practice, it can be used in almost the same way as the existing device 30. Preferably, even if the power receiving device 20 has a portion that protrudes from the outside (see the X-axis direction in Figure 8), the direction of the protrusion is made to align with the conventional wiring direction (see the wiring in Figure 2(C)). Therefore, the usability of the conventional device is not substantially impaired. Preferably, when mounting the power receiving device 20 on the device housings 31 and 310, it is designed so as not to interfere with the device's working surface (32 in Figure 8, 350 in Figure 21). Therefore, the usability of the previous device is not substantially impaired.

[0134] In Figure 33, when the inverted F antenna 700 is mounted upward (in the Z-axis direction) from the top surface of the housing 310, a portion of the substrate 740 protrudes perpendicular to the direction of the antenna's protrusion (in the X-axis direction and / or Y-axis direction). However, overall, the proportion of the substrate 740's protrusion (in the X-axis direction) is relatively small and can be ignored in practice. For example, if the protrusion is less than 10% of the size of the top surface of the housing 310, it does not cause any substantial damage and can therefore be ignored. The important point is to minimize the proportion of the substrate 740's protrusion (in the X-axis direction), even if it is slight. As a result, it does not affect the operation of the device 300 and does not enlarge the mounting space for the device 30.

[0135] The devices 30 and 300, powered by the power receiving device 20, may operate in a low-power mode (a mode that enables operation with approximately one-fifth the power consumption compared to existing operating methods) as illustrated in Figure 4, or they may operate in a normal power mode. Furthermore, the devices 30 and 300 may operate with power consumption less than one-half and up to approximately one-fifth compared to existing operating methods.

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

[0137] The housings 31 and 310 are defined as the housings that define the main body of the device. The housings 31 and 310 completely enclose the internal components (circuits, etc.) of the device, but depending on the embodiment, it is not always necessary to completely enclose the internal components of the device, and it is possible to expose some of them.

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

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

[0140] The power receiving device 20 may further allow adjustment of the antenna's power receiving status, depending on the embodiment. For example, the protruding length of the dipole antenna 21 illustrated in Figure 8 and the protruding length of the monopole antenna 230 illustrated in Figure 18 may be changeable. The dipole antenna 21 illustrated in Figure 8, the monopole antenna 230 illustrated in Figure 18, and linear tip antennas, etc., may be configured to be detachable, separable, extendable, or foldable.

[0141] Furthermore, in the actuator 300 illustrated in Figure 25, for example, the bolts 361, 362, 371, and 372 on the substrates 360 and 370 function to conduct current, but their positions may be adjustable. For example, the bolts 361, 362, 371, and 372 are screwed into holes drilled in the substrates 360 and 370, and their height can be changed by adjusting the screwing state. Depending on the power supply conditions, the protruding height of the bolts 361, 362, 371, and 372 may be adjusted to obtain the optimal current value.

[0142] Furthermore, in the actuator 300 illustrated in Figure 25, the depth, length, width, and / or power supply position of the slots 330 and 340 drilled in the housing 310 may be adjustable. For example, the depth, length, width, etc. of the recessed slots 330 and 340 in the housing 310 can be changed by fitting appropriate members into them. Depending on the power supply conditions, the depth, length, width, etc. of the slots 330 and 340 may be adjusted to obtain the optimal power supply position.

[0143] Furthermore, in the actuator 300 illustrated in Figure 25, a power receiving IC may be mounted on the circuit boards 360 and 370 to allow adjustment of the antenna's power reception status. The adjustment of bolts 361, 362, 371, and 372, and slots 330 and 340 may be performed manually or configured to be performed automatically.

[0144] Furthermore, in the actuator 300 illustrated in Figure 25, if rectifiers 363 and 373 are mounted on 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 search for a positive power supply position. The power receiving IC may also avoid impedance mismatch without using an impedance matching circuit by determining the power supply position according to the power receiving conditions.

[0145] Furthermore, in this embodiment, the power receiving system 1 or power receiving device 20 may include a CPU (processing unit or processor) and memory (storage device) to enable control of the above-mentioned functions for adjusting the power receiving status of the antenna. A CPU is generally defined as a device that executes software (programs). For example, a von Neumann-type CPU is one such example. A CPU can include a control unit that manages the entire system, an arithmetic unit, registers for temporary data storage, an interface to memory, and an interface to input / output devices for peripherals. Memory is defined as a device capable of storing data. For example, memory can be primary storage that the CPU can access directly, or secondary storage accessed using input / output channels, etc. For example, memory can be any media, a fixed disk, volatile or non-volatile random access memory, a CD, a DVD, a flash drive, removable media (e.g., a thumb-sized miniature memory) that can be attached to a corresponding interface (e.g., a USB port), or similar devices.

[0146] Furthermore, in this embodiment, the power receiving system 1 or power receiving device 20 may be provided as a computer program product for controlling the power receiving status of the antenna. Computer program products may be implemented as programs, features, functions, routines, or executable objects. Therefore, this relates to a computer program product for performing the above control.

[0147] Computer program products, such as computer program means, can be implemented as files downloadable from memory cards, USB sticks, CD-ROMs, DVDs, or servers on a network. For example, such files may be provided by transferring files containing computer program products over a wireless communication network.

[0148] Those skilled in the art will be able to 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 power receiving system 1 may include other components necessary for its operation, and may also include additional components to provide functions other than those described herein. Therefore, it should be understood that the claims of this patent may be implemented in ways other than those specifically described herein.

[0149] The embodiments described above disclose at least the following configurations. (1) A housing that constitutes the main body of a device that is a sensor or actuator, The aforementioned housing is fitted with a power receiving device that mainly generates an electric or magnetic field for wireless power supply. The power receiving device is at least one of a dipole antenna, slot antenna, monopole antenna, tip antenna, and inverted F antenna. The enclosure has a size within a three-dimensional space, and the expansion of the enclosure's size within that three-dimensional space due to the installation of the power receiving device is limited to substantially one axis at most. For example, the expansion of the enclosure's size in three-dimensional space due to the addition of a power receiving device can be substantially limited to one axis (in the case of dipole antennas, monopole antennas, linear tip antennas, and inverted F antennas), or the expansion of the enclosure's size in three-dimensional space due to the addition of a power receiving device can be substantially eliminated (in the case of slot antennas and planar tip antennas). In the latter case, power can be received simply by cutting a slot into the enclosure, thus enabling the construction of an antenna-less wireless power supply device. Preferably, even if the size of the housing is increased in one direction by providing a power receiving device, the proportion of the protrusion should be kept to a minimum. For example, it should be no more than twice the size of the housing in that direction, or no more than 1.5 times. The antenna can also be configured to be detachable, separable, extendable, or foldable. Therefore, the wireless devices 30 and 300 of this proposal can be used in substantially the same way as conventional wired powered devices, without requiring an expansion of the mounting space. (2) The power receiving device comprises 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. The slot antenna and the dipole antenna constitute an omnidirectional antenna having substantially orthogonal radiation or reception patterns (see Figures 8 and 9). (3) The power receiving device comprises 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. The slot antenna and the monopole antenna together constitute an omnidirectional antenna having substantially orthogonal radiation or reception patterns (see Figures 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 substantially intersecting directions. The first and second slot antennas constitute an omnidirectional antenna having substantially orthogonal radiation or reception patterns (see Figures 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 substantially in the same direction. The slot antenna and the inverted F antenna constitute an omnidirectional antenna having substantially orthogonal radiation or reception patterns (see Figures 8, 31, 21, and 33). (6) The power receiving device mainly includes a slot antenna that generates a magnetic field and a chip antenna. The slot antenna and the chip antenna are aligned in substantially the same direction. The slot antenna and the chip antenna constitute an omnidirectional antenna having substantially orthogonal radiation or reception patterns (see Figure 25). (7) The power receiving device has at least two antennas selected from a dipole antenna, a slot antenna, a monopole antenna, a tip antenna, and an inverted F antenna, such that each of the antennas has substantially different radiation or power receiving patterns. In particular, the two antennas 21 and 22 are configured to have different directivity characteristics, complementing each other in areas where the directivity of both antennas is weaker. (8) The power receiving device is a slot antenna, The addition of the power receiving device substantially eliminated the expansion of the enclosure's size within the three-dimensional space. In particular, when installing a slot antenna in the enclosure, the hole is drilled along the long axis of the enclosure so as to penetrate the wall of the enclosure in the thickness direction (see Figures 17, 21, and 25). (9) The housing may have a metal connector that allows wiring for wired power supply (see reference numeral 33 in Figures 8 and 2), and the power receiving device is attached to the connector. Therefore, by replacing only a part of the casing (see Figure 8 and Figure 2, reference numeral 33), wireless power supply is made possible, allowing for maximum utilization of the existing casing. (10) The aforementioned enclosure is equipped with a rectifier and an integrated chip antenna (see Figures 25 and 26). (11) The housing comprises the slot antenna and a voltage through which current flows (see Figures 25 and 26). (12) A device that is a sensor or actuator, Having a housing for the above-mentioned device, Wireless power transfer is performed using a microwave system. (13) A system comprising a device which is a sensor or actuator, and a filter which receives the output of the device, The device has a housing for the above-mentioned device, The filter enables operation with approximately one-fifth the power consumption compared to the existing operating methods of the sensor or actuator. The device may be able to operate with power ranging from less than one-half to about one-fifth of that of existing operating methods. The device may be made powerable by wireless power supply, and its data transmission may also be made wireless, thereby achieving complete wireless operation of the device. [Explanation of Symbols]

[0150] 1 System 10 Power transmission equipment 20 Power receiving equipment 21 Dipole Antenna 22-slot antenna 30 devices (sensors) 31 cabinets 33 Connectors 210 Dipole Antenna 220 Slot Antenna 230 Monopole Antenna 300 devices (actuators) 310 cabinets 330 Slot Antenna 340 Slot Antenna 363 Rectifier (integrated with chip antenna) 373 Rectifier (integrated with chip antenna) 400 Inverted F Antenna 700 Inverted F Antenna

Claims

1. It is a sensor system, A power receiving device configured to be attachable to a metal housing that houses the movable parts of an actuator, generates power based on received electromagnetic waves, and supplies power to at least one of the sensor or the actuator, The sensor operates using power supplied from the aforementioned power receiving device, measures a physical quantity of an object, and generates information regarding the measurement results, A control unit that transmits a signal relating to the measurement result generated by the sensor via wireless communication, The device comprises a circuit that suppresses impedance mismatch in the power receiving device caused by the metal housing receiving the electromagnetic waves, The power receiving device is a sensor system that receives electromagnetic waves for generating power to be supplied to at least one of the sensors or actuators, using the metal housing as an antenna.

2. The aforementioned metal housing has a plurality of recesses, The sensor system according to claim 1, wherein the power receiving device receives electromagnetic waves for generating power by using the plurality of recesses of the metal housing as antennas.

3. The sensor system according to claim 1 or 2, wherein the circuit determines the power supply position according to the power reception conditions, taking into account the electromagnetic waves received by the metal housing, thereby suppressing impedance mismatch.

4. The sensor system according to any one of claims 1 to 3, wherein the object is the actuator, and the sensor measures a physical quantity that is changed by the actuator.

5. The sensor system according to any one of claims 1 to 4, further comprising a circuit board to which a receiving antenna for receiving electromagnetic waves for generating power is attached.

6. The sensor system according to claim 5, wherein the receiving antenna is at least one of a dipole antenna, a slot antenna, a monopole antenna, a tip antenna, or an inverted F antenna.

7. It is an FA system, An actuator comprising a movable part and a metal housing that houses the movable part, A power receiving device that generates power based on received electromagnetic waves and supplies power to at least one of the sensors or actuators, The sensor operates using power supplied from the aforementioned power receiving device, measures a physical quantity of an object, and generates information regarding the measurement results, A control unit that transmits a signal relating to the measurement result generated by the sensor via wireless communication, The device comprises a circuit that suppresses impedance mismatch in the power receiving device caused by the metal housing receiving the electromagnetic waves, The power receiving device is an FA system that receives electromagnetic waves for generating power to be supplied to at least one of the sensors or actuators, using the metal housing as an antenna.

8. The aforementioned metal housing has a plurality of recesses, The FA system according to claim 7, wherein the power receiving device receives electromagnetic waves for generating power by using the plurality of recesses of the metal housing as antennas.

9. The FA system according to claim 7 or 8, wherein the circuit suppresses impedance mismatch by determining the power supply position according to the power reception conditions, taking into account the electromagnetic waves received by the metal housing.

10. The FA system according to any one of claims 7 to 9, wherein the object is the actuator, and the sensor measures a physical quantity that is changed by the actuator.

11. The FA system according to any one of claims 7 to 10, wherein the power receiving device further comprises a circuit board on which a receiving antenna for receiving the electromagnetic waves for generating power is attached.

12. The FA system according to claim 11, wherein the receiving antenna is at least one of a dipole antenna, a slot antenna, a monopole antenna, a tip antenna, or an inverted F antenna.

13. A sensor system, A power receiving device configured to be attachable to a metal housing that houses the movable parts of an actuator, generates power based on received electromagnetic waves, and supplies power to at least one of the sensor or the actuator, The sensor operates using power supplied from the aforementioned power receiving device, measures a physical quantity of an object, and generates information regarding the measurement results, A control unit that transmits a signal relating to the measurement result generated by the sensor via wireless communication, The device comprises a circuit that suppresses impedance mismatch in the power receiving device caused by the metal housing receiving the electromagnetic waves, The circuit is a sensor system that suppresses impedance mismatch by determining the power supply position according to the power reception conditions, taking into account the electromagnetic waves received by the metal housing.

14. The sensor system according to claim 13, wherein the power receiving device receives electromagnetic waves for generating power to be supplied to at least one of the sensor or the actuator, using the metal housing as an antenna.

15. The metal housing has a plurality of recesses, The sensor system according to claim 13 or 14, wherein the power receiving device receives electromagnetic waves for generating power by using the plurality of recesses of the metal housing as antennas.

16. The sensor system according to any one of claims 13 to 15, wherein the object is the actuator and the sensor measures a physical quantity that is changed by the actuator.

17. The sensor system according to any one of claims 13 to 16, further comprising a circuit board on which a receiving antenna for receiving electromagnetic waves for generating power is attached.

18. The sensor system according to claim 17, wherein the receiving antenna is at least one of a dipole antenna, a slot antenna, a monopole antenna, a tip antenna, or an inverted F antenna.

19. An FA system, An actuator comprising a movable part and a metal housing that houses the movable part, A power receiving device that generates power based on received electromagnetic waves and supplies power to at least one of the sensors or actuators, The sensor operates using power supplied from the aforementioned power receiving device, measures a physical quantity of an object, and generates information regarding the measurement results, A control unit that transmits a signal relating to the measurement result generated by the sensor via wireless communication, A circuit to suppress impedance mismatch in the power receiving device caused by the metal housing receiving the electromagnetic waves, Equipped with, The circuit is an FA system that suppresses impedance mismatch by determining the power supply position according to the power reception conditions, taking into account the electromagnetic waves received by the metal housing.

20. The FA system according to claim 19, wherein the power receiving device receives electromagnetic waves for generating power to be supplied to at least one of the sensor or the actuator, using the metal housing as an antenna.

21. The metal housing has a plurality of recesses, The FA system according to claim 19 or 20, wherein the power receiving device receives electromagnetic waves for generating power by using the plurality of recesses of the metal housing as antennas.

22. The FA system according to any one of claims 19 to 21, wherein the object is the actuator and the sensor measures a physical quantity that is changed by the actuator.

23. The FA system according to any one of claims 19 to 22, wherein the power receiving device further comprises a substrate on which an antenna for receiving electromagnetic waves for generating power is attached.

24. The FA system according to claim 23, wherein the antenna is at least one of a dipole antenna, a slot antenna, a monopole antenna, a tip antenna, or an inverted F antenna.

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