Sensor unit

Abstract

To provide a sensor unit having a configuration which allows reduction in size and weight.SOLUTION: A sensor unit 100 has: a substrate 1; a sensor 2; a communication antenna 3 which transmits detection data; a communication control part 4 which controls the transmission of the detection data; a receiving antenna 5 which receives power transmission waves; an all-solid secondary battery 6 which is charged with electric power based on the power transmission waves and supplies the electric power to the substrate, the sensor, and the communication control part; and a wireless power supply control part 7 which controls the charging of the secondary battery with the electric power based on the power transmission waves. At least one of the sensor, the communication control part, the secondary battery and the wireless power supply control part is located on one side in the thickness direction of the substrate with respect to the substrate. The rest of the sensor, the communication control part, the secondary battery and the wireless power supply control part are located on the other side in the thickness direction with respect to the substrate.SELECTED DRAWING: Figure 4

Description

Technical Field

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[0001] The present invention relates to a sensor unit.

Background Art

[0002] There is known a wireless sensor that wirelessly transmits the result of detection using a sensor. For example, in Patent Document 1, there is disclosed a wireless sensor including a power supply unit that supplies power, a sensor, a wireless communication circuit that operates by the power supplied from the power supply unit, and a sensor control circuit that operates by the power supplied from the power supply unit and transmits data indicating the detection result of the sensor to the outside via the wireless communication circuit.

[0003] The power supply unit of the wireless sensor includes a secondary battery, a power receiving circuit that receives power in a non-contact manner, and a power supply control circuit that charges the secondary battery with the power received by the power receiving circuit and supplies the power from the secondary battery and the power received by the power receiving circuit to the wireless communication circuit and the sensor control circuit. The wireless sensor has, as an operation mode, a standard mode in which data acquired from the sensor by the sensor control circuit is transmitted to the outside via the wireless communication circuit, and a diagnosis mode in which at least one of the secondary battery and the sensor is diagnosed when the power receiving circuit receives power in a non-contact manner.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The wireless sensor described in Patent Document 1 incorporates a secondary battery. Generally, the capacity of a secondary battery decreases over time. Therefore, it is conceivable to mount a large-capacity secondary battery in the wireless sensor, taking into account the decrease in capacity over time. However, if such a large secondary battery is mounted in the wireless sensor, the size of the wireless sensor will increase.

[0006] When the wireless sensor is large, the installation and subsequent maintenance of the wireless sensor are burdensome. From the viewpoint of ease of installation and subsequent maintenance, there is a need for a sensor unit with a configuration that can be miniaturized.

[0007] The objective of the present invention is to realize a sensor unit having a configuration that allows for miniaturization. [Means for solving the problem]

[0008] A sensor unit according to one embodiment of the present invention includes a substrate, a sensor for detecting the state of an object to be detected, a communication antenna for transmitting detection data relating to the detection result by the sensor, a communication control unit mounted on the substrate and controlling the transmission of the detection data by the communication antenna, a receiving antenna for receiving power transmission radio waves emitted from a power transmission antenna, a secondary battery for charging the power converted from the power transmission radio waves received by the power receiving antenna and supplying power to the substrate, the sensor and the communication control unit, and a wireless power supply control unit mounted on the substrate and controlling the charging of the secondary battery with power based on the power transmission radio waves. At least one of the sensor, the communication control unit, the secondary battery and the wireless power supply control unit is located on one side of the substrate in the thickness direction. The remaining parts of the sensor, the communication control unit, the secondary battery and the wireless power supply control unit are located on the other side of the substrate in the thickness direction (first configuration).

[0009] With the above configuration, the sensor, communication control unit, secondary battery, and wireless power supply control unit that constitute the sensor unit are arranged on both sides of the substrate. As a result, the sensor, communication control unit, secondary battery, and wireless power supply control unit can be arranged more compactly on the substrate compared to when they are arranged side by side on one side of the substrate. Therefore, the sensor unit can be miniaturized.

[0010] In the first configuration described above, one of the communication antenna or the power receiving antenna is located on the substrate in one direction in the thickness direction. The other of the communication antenna or the power receiving antenna is located on the substrate in the other direction in the thickness direction (second configuration).

[0011] This allows for a more compact arrangement of the power receiving antenna and the communication antenna compared to the case where the power receiving antenna and the communication antenna are arranged side by side on one side in the thickness direction of the substrate.

[0012] Furthermore, the receiving antenna and the communication antenna, which receive radio waves at different frequencies, are distributed on both sides of the substrate. This also makes it possible to prevent interference between the power transmission radio waves and the detection data transmission waves.

[0013] In the second configuration described above, the sensor unit has a first cover portion on which the power receiving antenna is formed, and a second cover portion on which the communication antenna is formed. One of the first cover portion or the second cover portion is located in one direction in the thickness direction relative to the substrate. The other of the first cover portion or the second cover portion is located in the other direction in the thickness direction relative to the substrate. The first cover portion and the second cover portion, when combined, constitute the outer shell of the sensor unit. The substrate, the sensor, the communication control unit, the secondary battery, and the wireless power supply control unit are located within the housing space formed by the first cover portion and the second cover portion (third configuration).

[0014] A power receiving antenna is formed on the first cover portion, and a communication antenna is formed on the second cover portion. This reduces the number of parts in the sensor unit compared to a case where the power receiving antenna and the communication antenna are separate from the sensor unit's cover. Therefore, the sensor unit can be made smaller and lighter.

[0015] Furthermore, the substrate, sensor, communication control unit, secondary battery, and wireless power supply control unit are housed within the housing space formed by the first and second cover sections. This protects the substrate, sensor, communication control unit, secondary battery, and wireless power supply control unit from moisture and dust. Therefore, the sensor unit can continue to operate without failure even in wet or high-humidity environments. For example, the sensor unit can be used outdoors and underwater.

[0016] In any one of the first to third configurations, the secondary battery is located on the opposite side of the substrate from the sensor in the thickness direction (fourth configuration).

[0017] This allows for a more compact arrangement of the secondary battery and sensor when viewed in the thickness direction of the substrate, compared to when the secondary battery and sensor are placed on the same side of the substrate in the thickness direction. Consequently, the sensor unit can be miniaturized.

[0018] In any one of the first to fourth configurations, the secondary battery is located on the same side as the wireless power supply control unit with respect to the substrate in the thickness direction (fifth configuration).

[0019] In the above configuration, the distance between the secondary battery and the wireless power supply control unit is shorter compared to the case where the wireless power supply control unit and the secondary battery are separately arranged on opposite sides of the circuit board. This allows for shorter wiring to electrically connect the wireless power supply control unit and the secondary battery. As a result, the sensor unit can be made smaller and lighter. Furthermore, as mentioned above, because the wiring is short, noise generated by the wiring can be reduced.

[0020] In the fifth configuration, the power receiving antenna is located on the same side of the substrate as the secondary battery and the wireless power supply control unit in the thickness direction (sixth configuration).

[0021] In the above configuration, compared with the case where the wireless power supply control unit, the power receiving antenna, and the secondary battery are separately arranged on both sides of the substrate, the distances between the wireless power supply control unit, the power receiving antenna, and the secondary battery are close. Thereby, the wiring connecting the wireless power supply control unit, the power receiving antenna, and the secondary battery can be shortened. As a result, the sensor unit can be miniaturized and lightened. Further, since the wiring is short as described above, the noise generated by the wiring can be reduced.

[0022] In any one of the first to sixth configurations, the communication antenna is located on the same side of the substrate as the communication control unit in the thickness direction (seventh configuration).

[0023] In the above configuration, compared with the case where the communication antenna and the communication control unit are separately arranged on both sides of the substrate, the distance between the communication antenna and the communication control unit is close. Thereby, the wiring electrically connecting the communication antenna and the communication control unit can be shortened. Thus, the sensor unit can be miniaturized and lightened. Further, since the wiring is short as described above, the noise generated by the wiring can be reduced.

[0024] In any one of the first to seventh configurations, the secondary battery is an all-solid-state secondary battery (eighth configuration).

[0025] The operating temperature range of the all-solid-state secondary battery is wider than that of the secondary battery with a liquid electrolyte. Therefore, the sensor unit can be used even in a high-temperature environment or a low-temperature environment where it could not be used conventionally. Furthermore, the shape restrictions in the all-solid-state secondary battery are fewer than those in a battery with a liquid electrolyte. That is, the all-solid-state secondary battery has more freedom in shape than a battery with a liquid electrolyte. Thus, miniaturization of the sensor unit is also possible.

[0026] In any one of the first to eighth configurations, the sensor unit has an electromagnetic wave absorption member located between the substrate and the sensor (ninth configuration).

[0027] The electromagnetic wave absorption member absorbs noise caused by electromagnetic waves. Thus, the substrate and the sensor are protected from noise by the electromagnetic wave absorption member. Therefore, malfunction of the substrate and the sensor can be prevented.

Advantages of the Invention

[0028] According to the sensor unit according to an exemplary embodiment of the present invention, a sensor unit having a configuration that enables miniaturization is realized.

Brief Description of the Drawings

[0029] <( [Figure 1] FIG. 1 is a block diagram showing an example of the configuration of a sensor unit according to an embodiment. [Figure 2] FIG. 2 is a diagram showing an example of an all-solid-state secondary battery according to an embodiment. [Figure 3] FIG. 3 is a diagram showing an example of the shape of the outer shell of a sensor unit according to an embodiment. [Figure 4] ]>FIG. 4 is a diagram showing an example of a sensor unit according to an embodiment. [Figure 5] FIG. 5 is a diagram showing an example of the arrangement of a substrate, a sensor, a communication control unit, an all-solid-state secondary battery, and a wireless power supply control unit according to an embodiment. [Figure 6]Figure 6 shows an example of a method for forming a power receiving antenna and a communication antenna according to the embodiment. [Modes for carrying out the invention]

[0030] The embodiments of the present invention will be described in detail below with reference to the drawings. Note that identical or corresponding parts in the drawings are denoted by the same reference numerals, and their descriptions will not be repeated. Furthermore, the dimensions of the components in each drawing do not necessarily accurately represent the actual dimensions of the components or their dimensional ratios.

[0031] In the following explanation, the thickness direction of the substrate 1 will be simply referred to as the "thickness direction." However, this definition of direction is not intended to limit the orientation of the sensor unit 100 when it is in use.

[0032] <Embodiment> (Overview of sensor unit 100) The overview of the sensor unit 100 will be explained using Figures 1 and 2.

[0033] The sensor unit 100 detects the state of the object to be detected at the installation site and wirelessly transmits detection data related to the detection result. The sensor unit 100 can be installed both indoors and outdoors. The sensor unit 100 allows for continuous, unattended monitoring of the object to be detected. When the sensor unit 100 is installed outdoors, the object to be detected includes, for example, port facilities, bridges, tunnels, steel structures, elevated bridges, or roads. However, the object to be detected is not limited to these structures.

[0034] As shown in Figure 1, the sensor unit 100 includes a substrate 1, a sensor 2, a communication antenna 3, a communication control unit 4, a power receiving antenna 5, an all-solid-state secondary battery 6, and a wireless power supply control unit 7.

[0035] The circuit board 1 has predetermined wiring formed on at least one of its two sides. The wiring on the circuit board 1 is electrically connected to the sensor 2, the communication antenna 3, the communication control unit 4, the power receiving antenna 5, the all-solid-state secondary battery 6, and the wireless power supply control unit 7. For example, the communication control unit 4 and the wireless power supply control unit 7 are mounted on the circuit board 1. Although not specifically described, other elements besides the communication control unit 4 and the wireless power supply control unit 7 are also mounted on the circuit board 1.

[0036] Sensor 2 detects the state of the object to be detected. Sensor 2 includes, for example, a sonar sensor, ultrasonic sensor, X-ray sensor, magnetic sensor, microwave sensor, or camera. A sensor that transmits and receives radio waves with a frequency of 300 MHz to 3 GHz can be used as a microwave sensor. Sensor 2 is not particularly limited to the above-mentioned sensors, as long as it is a sensor capable of detecting the state of the object to be detected. Furthermore, sensor unit 100 may have one sensor 2 or multiple sensors 2.

[0037] The communication antenna 3 transmits detection data, which is data related to the detection results of the sensor 2. For example, the communication antenna 3 can transmit radio waves compliant with the 5G communication standard. However, the communication antenna 3 may also transmit radio waves compliant with communication standards other than 5G.

[0038] For example, the communication control unit 4 is a communication control circuit that controls the transmission of the detection data from the communication antenna 3. The communication control unit 4 generates the detection data based on the detection result which is the output of the sensor 2, and performs modulation processing to modulate the detection data. The communication control unit 4 inputs the signal obtained by the modulation processing to the communication antenna 3. As a result, the detection data is transmitted from the communication antenna 3 as the signal.

[0039] The receiving antenna 5 receives the transmission radio waves emitted from the transmitting antenna 200. For example, the transmission radio waves are microwaves. Power is supplied to the sensor unit 100 by wireless power transmission using microwaves. The white arrows shown in Figure 1 indicate the flow of power.

[0040] The all-solid-state secondary battery 6 is charged with power obtained by converting the radio waves for power transmission received by the power receiving antenna 5. The all-solid-state secondary battery 6 also supplies power to the substrate 1, sensor 2, and communication control unit 4.

[0041] Specifically, the all-solid-state secondary battery 6 according to this embodiment is an all-solid-state lithium-ion battery. In the all-solid-state secondary battery 6, the electrolyte is solid. All-solid-state lithium-ion batteries and lithium-ion batteries with a liquid electrolyte have in common that Li ions are transported between the positive electrode and the negative electrode.

[0042] The temperature range in which the all-solid-state secondary battery 6 operates stably and safely is wider than that of liquid electrolyte secondary batteries, both at low and high temperatures. Therefore, the sensor unit 100 can be used stably and safely without significant capacity degradation even in high-temperature environments exceeding 80°C or low-temperature environments below -20°C, where conventional liquid electrolyte lithium-ion batteries cannot be used. Furthermore, the shape limitations of the all-solid-state secondary battery 6 are less than those of batteries with liquid electrolytes. In other words, the all-solid-state secondary battery 6 has more shape freedom than batteries with liquid electrolytes. Therefore, miniaturization of the sensor unit 100 is also possible.

[0043] Figure 2 shows an example of an all-solid-state secondary battery 6 according to the embodiment. The all-solid-state secondary battery 6 shown in Figure 2 has a laminate film outer casing 61 and an electrode body 62.

[0044] The laminate film outer casing 61 is made of a metal laminate film. The outer periphery of the metal laminate film is heat-sealed with the electrode body 62 sandwiched between them to form the laminate film outer casing 61.

[0045] The electrode body 62 has the same configuration as conventional all-solid-state secondary batteries. Therefore, the configuration of the electrode body 62 will be briefly described below. Although not shown in the figures, the electrode body 62 has a negative electrode, a positive electrode, and a solid electrolyte layer located between the positive electrode and the negative electrode.

[0046] The negative electrode comprises a molded body containing a negative electrode active material, a solid electrolyte, and a negative electrode mixture. For example, the negative electrode active material contains lithium titanium oxide. The solid electrolyte is a sulfide-based solid electrolyte with excellent ionic conductivity. However, a solid electrolyte other than a sulfide-based solid electrolyte may be used as the solid electrolyte of the negative electrode. The negative electrode mixture contains a conductive additive.

[0047] The positive electrode comprises a molded body containing a positive electrode active material, a solid electrolyte, and a positive electrode mixture. The positive electrode active material may be any active material capable of intercalating and releasing Li ions. For example, the positive electrode active material may be one used in conventional lithium-ion secondary batteries. The solid electrolyte may be the same as that used in the negative electrode. For example, the solid electrolyte may contain a sulfide-based solid electrolyte. However, a solid electrolyte other than a sulfide-based solid electrolyte may be used for the solid electrolyte. The positive electrode mixture contains a conductive additive and a binder.

[0048] The solid electrolyte layer located between the positive electrode and the negative electrode is composed of a solid electrolyte. The same solid electrolyte as that used in the negative electrode can be used for the solid electrolyte. For example, the solid electrolyte contains a sulfide-based solid electrolyte. However, the solid electrolyte may be a solid electrolyte other than a sulfide-based solid electrolyte.

[0049] The positive electrode connection terminal 63 is connected to the positive electrode of the electrode body 62 and extends outward from the electrode body 62. The negative electrode connection terminal (not shown) is connected to the negative electrode of the electrode body 62 and extends outward from the electrode body 62.

[0050] The wireless power supply control unit 7 converts the radio waves for power transmission received by the power receiving antenna 5 into electrical power and controls the charging of the converted electrical power to the solid-state secondary battery 6. When charging the solid-state secondary battery 6, the wireless power supply control unit 7 supplies the electrical power converted from the radio waves for power transmission to the solid-state secondary battery 6 by the power conversion circuit and controls the charging of the solid-state secondary battery 6. As a result, the solid-state secondary battery 6 is charged.

[0051] For example, the wireless power supply control unit 7 charges the solid-state secondary battery 6 when its voltage is below a predetermined threshold voltage. Also, for example, the wireless power supply control unit 7 stops charging the solid-state secondary battery 6 when its voltage rises above the threshold voltage.

[0052] A power supply control circuit (not shown) provided on the circuit board 1 supplies power from the all-solid-state secondary battery 6 to the circuit board 1, sensor 2, and communication control unit 4 when transmitting detection data. As a result, the powered sensor 2 operates, and the powered communication control unit 4 generates detection data and wirelessly transmits the generated detection data.

[0053] (Details of sensor unit 100) Next, the details of the sensor unit 100 according to this embodiment will be explained using Figures 3 to 5.

[0054] As shown in Figure 3, the sensor unit 100 has an ellipsoidal shape. As shown in Figure 4, the sensor unit 100 includes a substrate 1, a sensor 2, a communication antenna 3, a communication control unit 4, a power receiving antenna 5, a solid-state secondary battery 6, a wireless power supply control unit 7, a heat dissipation unit 8, and a cover unit 9. Figure 4 is a cross-sectional view of the sensor unit 100 when it is cut in the direction of the long axis shown in Figure 3, with the substrate 1 having a horizontal plane.

[0055] The cover portion 9 constitutes the outer shell of the sensor unit 100. As shown in Figure 4, the circuit board 1, sensor 2, communication antenna 3, communication control unit 4, power receiving antenna 5, all-solid-state secondary battery 6, wireless power supply control unit 7, and heat dissipation unit 8 are housed inside the cover portion 9.

[0056] At least one of the sensor 2, communication control unit 4, all-solid-state secondary battery 6, and wireless power supply control unit 7 is located on one side of the substrate 1 in the thickness direction. The remaining components of the sensor 2, communication control unit 4, all-solid-state secondary battery 6, and wireless power supply control unit 7 are located on the other side of the substrate 1 in the thickness direction.

[0057] In this embodiment, as shown in Figure 4, the power receiving antenna 5, the all-solid-state secondary battery 6, and the wireless power supply control unit 7 are located on one side of the substrate 1 in the thickness direction. The sensor 2, the communication antenna 3, and the communication control unit 4 are located on the other side of the substrate 1 in the thickness direction.

[0058] Figure 5 is a view of the substrate 1 in the thickness direction. In Figure 5, the communication antenna 3, power receiving antenna 5, heat dissipation section 8, and cover section 9 are not shown. As shown in Figure 5, the all-solid-state secondary battery 6 overlaps with part of the sensor 2 and the communication control section 4 when the substrate 1 is viewed in the thickness direction. Also, the wireless power supply control section 7 overlaps with the sensor 2 when the substrate 1 is viewed in the thickness direction. Thus, a component located on one side of the substrate 1 in the thickness direction overlaps with at least part of a component located on the other side of the substrate 1 in the thickness direction when the substrate 1 is viewed in the thickness direction.

[0059] For example, the all-solid-state secondary battery 6 is located on the opposite side of the substrate 1 from the sensor 2 and communication control unit 4 in the thickness direction of the substrate 1, and overlaps with a portion of the sensor 2 and communication control unit 4 when viewed in the thickness direction of the substrate 1. Therefore, the all-solid-state secondary battery 6 and the sensor 2 can be arranged more compactly compared to when they are placed side by side on one plane of the substrate 1. Consequently, the sensor unit 100 can be miniaturized.

[0060] On the other hand, the all-solid-state secondary battery 6 is located on the same side as the wireless power supply control unit 7 with respect to the substrate 1 in the thickness direction. Moreover, the distance between the all-solid-state secondary battery 6 and the wireless power supply control unit 7 is closer than when the wireless power supply control unit 7 and the all-solid-state secondary battery 6 are separately arranged on opposite sides of the substrate 1. As a result, the wiring that electrically connects the wireless power supply control unit 7 and the all-solid-state secondary battery 6 can be shortened. Therefore, the sensor unit 100 can be made smaller and lighter.

[0061] The heat dissipation section 8 has an external shape resembling a spheroid. The heat dissipation section 8 covers the substrate 1, the sensor 2, the communication control unit 4, the all-solid-state secondary battery 6, and the wireless power supply control unit 7.

[0062] The heat dissipation section 8 is a layer of resin with high thermal conductivity. For example, the heat dissipation section 8 is made of a resin containing a thermally conductive filler. The heat dissipation section 8 is also in contact with the substrate 1, the sensor 2, and the all-solid-state secondary battery 6. As a result, heat from the substrate 1, the sensor 2, and the all-solid-state secondary battery 6 is conducted to the heat dissipation section 8.

[0063] The cover portion 9 covers the heat dissipation portion 8. Specifically, the cover portion 9 is located on the outermost part of the sensor unit 100 and covers the entire outer surface of the heat dissipation portion 8. The cover portion 9 has an internal housing space. The circuit board 1, sensor 2, communication control unit 4, all-solid-state secondary battery 6, wireless power supply control unit 7, and heat dissipation portion 8 are housed within the housing space enclosed by the cover portion 9.

[0064] The cover portion 9 includes a first cover portion 91 and a second cover portion 92. The first cover portion 91 is located on one side in the thickness direction relative to the substrate 1. The second cover portion 92 is located on the other side in the thickness direction relative to the substrate 1. The cover portion 9 is formed by combining the first cover portion 91 and the second cover portion 92. The first cover portion 91 and the second cover portion 92 may be made of any material that can form a cover for the sensor unit 100, such as thermoplastic resin, thermosetting resin, photocurable resin, ceramics, or glass.

[0065] Specifically, the first cover portion 91 and the second cover portion 92 are each bowl-shaped. When the first cover portion 91 and the second cover portion 92 are assembled, the central portion of the first cover portion 91 protrudes to one side in the thickness direction of the substrate 1. The central portion of the second cover portion 92 protrudes to the other side in the thickness direction of the substrate 1.

[0066] When viewed in the thickness direction, the first cover portion 91 and the second cover portion 92 each have elliptical edges. The edges of the first cover portion 91 and the second cover portion 92 are overlapped so that there is no gap between them. The edges are then fixed together without gaps by a fixing member (not shown). For example, the fixing member is an adhesive or adhesive tape. The first cover portion 91 and the second cover portion 92 may also be fixed by methods other than adhesive, such as welding or screw fixing.

[0067] As described above, the edges of the first cover portion 91 and the second cover portion 92 are fixed together without any gaps, so the circuit board 1, sensor 2, communication antenna 3, communication control unit 4, power receiving antenna 5, all-solid-state secondary battery 6, and wireless power supply control unit 7 are protected from moisture and dust. Therefore, the sensor unit 100 can operate without malfunction even in wet or high-humidity environments. For this reason, the sensor unit 100 can be used not only indoors but also outdoors or underwater.

[0068] When the first cover portion 91 and the second cover portion 92 are assembled, the inner surfaces of the first cover portion 91 and the second cover portion 92 are in contact with the outer surface of the heat dissipation portion 8. As a result, heat generated by the elements mounted on the substrate 1, such as the communication control portion 4 and the wireless power supply control portion 7, the sensor 2 and the all-solid-state secondary battery 6, is transferred to the cover portion 9 via the heat dissipation portion 8. The heat transferred to the cover portion 9 is then released into the outside air from the outer surfaces of the first cover and the second cover.

[0069] Here, a power receiving antenna 5 is formed on the inner surface of the first cover portion 91. Therefore, the power receiving antenna 5 is located on one side in the thickness direction relative to the substrate 1. Also, a communication antenna 3 is formed on the inner surface of the second cover portion 92. Therefore, the communication antenna 3 is located on the other side in the thickness direction relative to the substrate 1. Note that the power receiving antenna 5 and the communication antenna 3 may be positioned to overlap when viewed on the substrate 1 in the thickness direction.

[0070] This allows for a more compact arrangement of the communication antenna 3 and the power receiving antenna 5 compared to the case where the communication antenna 3 and the power receiving antenna 5 are arranged side by side on one side in the thickness direction of the substrate 1. Furthermore, with the above configuration, the communication antenna 3 and the power receiving antenna 5, which transmit and receive radio waves at different frequencies, are distributed on both sides of the substrate 1. This also makes it possible to effectively prevent interference between the power transmission radio waves and the transmission waves of the detection data.

[0071] Furthermore, with the above configuration, the number of components in the sensor unit 100 is reduced compared to when the communication antenna 3 and the power receiving antenna 5 are separate from the cover of the sensor unit 100. Therefore, the sensor unit 100 can be made smaller and lighter.

[0072] Furthermore, as shown in Figure 4, the communication antenna 3 and the power receiving antenna 5 are positioned to sandwich the substrate 1, sensor 2, communication control unit 4, all-solid-state secondary battery 6, and wireless power supply control unit 7 in the thickness direction. Specifically, when viewing the substrate 1 in the thickness direction, the communication antenna 3 and the power receiving antenna 5 overlap with at least one of the sensor 2, communication control unit 4, all-solid-state secondary battery 6, and wireless power supply control unit 7.

[0073] Furthermore, as shown in Figure 4, the power receiving antenna 5 is located on the same side as the all-solid-state secondary battery 6 and the wireless power transmission control unit 7 in the thickness direction relative to the substrate 1. This allows for shorter wiring for electrically connecting the power receiving antenna 5, the all-solid-state secondary battery 6, and the wireless power transmission control unit 7.

[0074] Furthermore, as shown in Figure 4, the communication antenna 3 is located on the same side as the communication control unit 4 with respect to the substrate 1 in the thickness direction. This allows for shorter wiring to electrically connect the communication antenna 3 and the communication control unit 4.

[0075] As shown in Figure 4, the sensor unit 100 has an electromagnetic wave absorbing member 101 located between the substrate 1 and the sensor 2. The electromagnetic wave absorbing member 101 absorbs noise. This protects the substrate 1 and the sensor 2 from noise. Therefore, malfunctions of the substrate 1 and the sensor 2 can be prevented.

[0076] (Antenna formation) An example of a method for forming the power receiving antenna 5 and the communication antenna 3 according to this embodiment will be explained using Figure 6.

[0077] The power receiving antenna 5 has a plated film of the antenna pattern formed on the inner surface of the first cover portion 91. The communication antenna 3 also has a plated film of the antenna pattern formed on the inner surface of the second cover portion 92.

[0078] As described above, the first cover portion 91 and the second cover portion 92 have a central part on the inner surface that protrudes in the thickness direction. Therefore, the antenna patterns of the power receiving antenna 5 and the communication antenna 3 are not simply flat surfaces, but are formed on curved surfaces with a central part that protrudes in the thickness direction.

[0079] In this embodiment, the MID (Molded Interconnect Device) method, described later, is used to form the power receiving antenna 5 on the first cover portion 91 and the communication antenna 3 on the second cover portion 92. This MID method uses the process shown in Figure 6 and can form a plating film on curved and uneven surfaces. The antenna pattern formed by this MID method has good surface smoothness, resulting in less noise generation. Therefore, especially when using high-frequency bands, the transmission and reception efficiency of the antenna pattern formed by this MID method is good.

[0080] For example, a simulation can determine the shape of the receiving antenna 5 that can efficiently receive microwaves. Based on the determined shape, the receiving antenna 5 is formed on the first cover portion 91. Similarly, a simulation can determine the shape of the communication antenna 3 that can efficiently transmit radio waves compliant with the adopted communication standard. Based on the determined shape, the communication antenna 3 is formed on the second cover portion 92.

[0081] An example of the formation of the power receiving antenna 5 in the first cover portion 91 using the MID method will be described. First, in the plating process using the MID method, a catalyst deactivator is applied to the inner surface of the first cover. It is presumed that the catalyst deactivator applied to the inner surface of the first cover either penetrates into the substrate or is adsorbed onto the surface of the substrate. Thus, the process of applying the catalyst deactivator is the catalyst deactivator application step S1 shown in Figure 6.

[0082] Next, laser light is irradiated onto the inner surface of the first cover, which is coated with the catalyst deactivator, according to the antenna pattern of the power receiving antenna 5 (laser drawing). As a result, the area irradiated with laser light is heated. Consequently, the catalyst deactivator present in the heated area is removed. This process of removing a portion of the catalyst deactivator is the laser irradiation step S2 shown in Figure 6. Note that the catalyst deactivator on the antenna pattern portion of the power receiving antenna 5 may also be removed by heating methods other than laser light.

[0083] Next, the electroless plating catalyst is supplied to the inner surface of the first cover. Specifically, the electroless plating catalyst solution is applied to the inner surface of the first cover by coating the electroless plating catalyst or by immersion in the electroless plating catalyst solution. Note that the electroless plating catalyst solution may also be applied to the inner surface of the first cover by methods other than coating or immersion. This process of applying the electroless plating catalyst solution to the inner surface of the first cover is the electroless plating catalyst application step S3 shown in Figure 6.

[0084] As an electroless plating catalyst, for example, metal nanoparticles such as Pd, Ni, Pt, and Cu, metal complexes, and metal alkoxides can be used. In particular, an electroless plating catalyst containing Pd, which has high catalytic activity, is preferred. However, the electroless plating catalyst can be any catalyst that has electroless plating catalytic activity and is not limited to the metal nanoparticles, metal complexes, and metal alkoxides of the above metals.

[0085] Next, electroless plating solution is supplied to the inner surface of the first cover. This brings the inner surface of the first cover into contact with the electroless plating solution. A film of the electroless plating solution is formed on the areas where the catalyst deactivator has been removed by heating. As a result, the antenna pattern of the power receiving antenna 5 is formed. This process of bringing the electroless plating solution into contact with the inner surface of the first cover is the electroless plating solution contact process of step S4 shown in Figure 6.

[0086] The communication antenna 3 on the second cover portion 92 can be formed using the MID method shown in Figure 5. The process of forming the communication antenna 3 on the second cover portion 92 is the same as the process of forming the power receiving antenna 5 on the first cover. Therefore, a detailed explanation is omitted.

[0087] As described above, the sensor unit 100 according to this embodiment includes a substrate 1, a sensor 2 for detecting the state of an object to be detected, a communication antenna 3 for transmitting detection data related to the detection result by the sensor 2, a communication control unit 4 mounted on the substrate 1 and controlling the transmission of detection data from the communication antenna 3, a receiving antenna 5 for receiving power transmission radio waves transmitted from a power transmission antenna 200, a solid-state secondary battery 6 for charging the power converted from the power transmission radio waves received by the receiving antenna 5 and supplying power to the substrate 1, sensor 2 and communication control unit 4, and a wireless power supply control unit 7 mounted on the substrate 1 and controlling the charging of the solid-state secondary battery 6 based on the power transmission radio waves received by the receiving antenna 5. At least one of the sensor 2, communication control unit 4, solid-state secondary battery 6 and wireless power supply control unit 7 is located on one side of the substrate 1 in the thickness direction. The remaining part of the sensor 2, communication control unit 4, solid-state secondary battery 6 and wireless power supply control unit 7 is located on the other side of the substrate 1 in the thickness direction.

[0088] The sensor 2, communication control unit 4, all-solid-state secondary battery 6, and wireless power supply control unit 7 that constitute the sensor unit 100 are arranged on both sides of the substrate 1. This allows for a more compact arrangement of the sensor 2, communication control unit 4, all-solid-state secondary battery 6, and wireless power supply control unit 7 compared to when they are arranged side by side on one side of the substrate 1. Therefore, the sensor unit 100 can be miniaturized.

[0089] <Other Embodiments> Although embodiments of the present invention have been described above, the embodiments described above are merely examples for carrying out the present invention. Therefore, the invention is not limited to the embodiments described above, and it is possible to carry out the invention by appropriately modifying the embodiments described above without departing from the spirit of the invention.

[0090] In the above embodiment, the power receiving antenna 5, the all-solid-state secondary battery 6, and the wireless power supply control unit 7 are located on one side of the thickness direction relative to the substrate 1, while the sensor 2, the communication antenna 3, and the communication control unit 4 are located on the other side of the thickness direction relative to the substrate 1. However, one or two of the power receiving antenna, the all-solid-state secondary battery, and the wireless power supply control unit may be located on the other side of the thickness direction relative to the substrate, and the rest may be located on one side of the thickness direction relative to the substrate. Alternatively, one or two of the sensor, the communication antenna, and the communication control unit may be located on one side of the thickness direction relative to the substrate, and the rest may be located on the other side of the thickness direction relative to the substrate.

[0091] Furthermore, in the above embodiment, the power receiving antenna 5 is located on one side of the thickness direction relative to the substrate 1, and the communication antenna 3 is located on the other side of the thickness direction relative to the substrate 1. However, the power receiving antenna may be located on the other side of the thickness direction relative to the substrate, and the communication antenna may be located on one side of the thickness direction relative to the substrate. Also, both the power receiving antenna and the communication antenna may be located on one or the other side of the thickness direction relative to the substrate.

[0092] In the above embodiment, a power receiving antenna 5 is formed on the first cover portion 91, and a communication antenna 3 is formed on the second cover portion 92. However, the communication antenna may be formed on the first cover portion and the power receiving antenna may be formed on the second cover portion. Furthermore, the power receiving antenna may not be formed on either the first or second cover portion, and may be separate from the first and second cover portions. Also, the communication antenna may not be formed on either the first or second cover portion, and may be separate from the first and second cover portions.

[0093] In the above embodiment, the first cover portion 91 is located on one side of the thickness direction relative to the substrate 1, and the second cover portion 92 is located on the other side of the thickness direction relative to the substrate 1. However, the first cover portion may be located on the other side of the thickness direction relative to the substrate, and the second cover portion may be located on one side of the thickness direction relative to the substrate.

[0094] In the above embodiment, the first cover portion 91 and the second cover portion 92 are combined. However, the first cover portion and the second cover portion may be a single unit.

[0095] In the above embodiment, the first cover portion 91 and the second cover portion 92 constitute the cover portion 9. However, the sensor unit does not necessarily have to have a cover portion.

[0096] Furthermore, in the above embodiment, the cover portion 9 covers the entire sensor unit 100. However, the cover portion does not have to cover the entire unit. For example, the cover portion may cover only a part of the heat dissipation portion.

[0097] In the above embodiment, the all-solid-state secondary battery 6 is located on the opposite side of the substrate 1 from the sensor 2 in the thickness direction. However, the all-solid-state secondary battery may be located on the same side of the substrate as the sensor in the thickness direction.

[0098] In the above embodiment, the wireless power supply control unit 7 is located on the same side as the secondary battery with respect to the substrate 1 in the thickness direction. However, the wireless power supply control unit may be located on the opposite side of the substrate from the secondary battery in the thickness direction.

[0099] In the above embodiment, the wireless power supply control unit 7 is located on the same side as the receiving antenna 5 and the all-solid-state secondary battery 6 with respect to the substrate 1 in the thickness direction. However, only one of the receiving antenna and the all-solid-state secondary battery may be located on the same side as the wireless power supply control unit with respect to the substrate in the thickness direction. Alternatively, both the receiving antenna and the all-solid-state secondary battery may be located on the opposite side of the substrate from the wireless power supply control unit in the thickness direction.

[0100] In the above embodiment, the communication control unit 4 is located on the same side as the communication antenna 3 with respect to the substrate 1 in the thickness direction. However, the communication control unit may be located on the opposite side of the substrate from the communication antenna in the thickness direction.

[0101] In the above embodiment, the sensor unit 100 has an all-solid-state secondary battery 6 as a secondary battery. However, the sensor unit may be equipped with a secondary battery with a liquid electrolyte instead of an all-solid-state secondary battery.

[0102] In the above embodiment, an all-solid-state secondary battery 6 having a laminate film casing 61 and an electrode body 62 as shown in Figure 2 was described. However, an all-solid-state secondary battery is not particularly limited to the above configuration as long as it can be charged and discharged using an all-solid-state electrolyte. For example, the casing of an all-solid-state secondary battery may consist of a casing can and a sealing can.

[0103] In the above embodiment, as shown in Figure 4, the sensor unit 100 has an electromagnetic wave absorbing member 101 located between the sensor 2 and the substrate 1. However, the sensor unit may also have an electromagnetic wave absorbing member located between the power receiving antenna and the substrate. Furthermore, the sensor unit may also have an electromagnetic wave absorbing member located between the communication antenna and the substrate. Moreover, the sensor unit may not have an electromagnetic wave absorbing member at all.

[0104] In the above embodiment, the outer shape of the cover portion 9 is a spheroid. However, the outer shape of the cover portion is not limited to a spheroid. The outer shape of the cover portion may be, for example, a sphere, cylinder, prism, cone, pyramidal, dome, or coin-shaped.

[0105] In the above embodiment, the sensor unit 100 has a cover portion 9 which is composed of a first cover portion 91 and a second cover portion 92. However, the cover portion may be composed of three or more members.

[0106] In the above embodiment, the communication antenna 3 and the power receiving antenna 5 are formed by the MID method. However, the power receiving antenna and the communication antenna may be formed using methods other than the MID method.

[0107] In the above embodiment, the communication antenna 3 transmits detection data, which is data relating to the detection result of the sensor 2. However, the communication antenna may be connected to a wireless power supply control unit, receive power transmission radio waves transmitted from a power transmission antenna, and the power obtained by converting the power transmission radio waves received by the communication antenna by the wireless power supply control unit is supplied to the sensor unit.

[0108] In the above embodiment, the receiving antenna 5 receives power transmission radio waves transmitted from the power transmitting antenna 200. However, the receiving antenna may be connected to a communication control unit, and detection data, which is data relating to the sensor's detection results, may be transmitted from the receiving antenna by the communication control unit.

[0109] In the above embodiment, the sensor unit 100 has a communication antenna 3 and a power receiving antenna 5. However, the communication antenna and the power receiving antenna may be integrated. In other words, the sensor unit 100 may have a single antenna that can be used as both a communication antenna and a power transmitting antenna. [Industrial applicability]

[0110] The present invention can be used in a sensor unit that has a sensor and transmits measurement data wirelessly. [Explanation of Symbols]

[0111] 100 Sensor Units 1 circuit board 2 sensors 3. Communication antenna 4. Communication Control Unit 5. Receiving antenna 6 All-solid-state secondary battery 61 Laminate film outer casing 62 Electrode body 63 Positive terminal 7 Wireless power supply control unit 8 Heat dissipation part 9. Cover section 91 First Cover Section 92. Second Cover Section 101 Electromagnetic wave absorbing material 200 Power transmission antenna

Claims

1. circuit board and A sensor that detects the state of the object to be detected, A communication antenna that transmits detection data related to the detection result from the aforementioned sensor, A communication control unit mounted on the aforementioned substrate controls the transmission of the detection data by the communication antenna, A receiving antenna that receives power transmission radio waves transmitted from a power transmission antenna, A secondary battery that charges the power converted from the power-transmitting radio waves received by the power-receiving antenna and supplies power to the circuit board, the sensor and the communication control unit, A wireless power supply control unit, mounted on the aforementioned substrate, controls the charging of the secondary battery with power based on the aforementioned power transmission radio waves, A sensor unit having, The secondary battery, the wireless power supply control unit, and the power receiving antenna are located on one side of the thickness direction of the substrate relative to the substrate. The sensor, the communication control unit, and the communication antenna are positioned relative to the substrate in the other direction in the thickness direction. Sensor unit.

2. In the sensor unit according to claim 1, The first cover portion on which the power receiving antenna is formed, It has a second cover portion on which the aforementioned communication antenna is formed, Either the first cover portion or the second cover portion is positioned in one direction in the thickness direction relative to the substrate, The other of the first cover portion or the second cover portion is located in the other direction in the thickness direction relative to the substrate, The first cover portion and the second cover portion, when combined, constitute the outer shell of the sensor unit. The substrate, the sensor, the communication control unit, the secondary battery, and the wireless power supply control unit are located within the housing space formed by the first cover and the second cover. Sensor unit.

3. In the sensor unit according to claim 1 or claim 2, The aforementioned secondary battery is an all-solid-state secondary battery. Sensor unit.

4. In the sensor unit according to claim 1 or claim 2, The system has an electromagnetic wave absorbing member located between the substrate and the sensor. Sensor unit.

5. In the sensor unit according to claim 1 or claim 2, The secondary battery is smaller than the substrate. Sensor unit.

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