Sensor unit and detecting device employing same

Abstract

Provided are a sensor unit and a detecting device capable of detecting a detection target wave from a detection target using a simple configuration. A sensor unit 10a is disposed relative to a detection target 200a in a state in which an open space ER1 is provided between a sensor 11 and the detection target 200a, and a detection target wave W from the detection target 200a is detected by means of the sensor 11, via the open space ER1. Since a sealed space is not formed in the sensor unit 10a, the configuration can be made correspondingly simpler, and the detection target wave W from the detection target 200a can be detected by the sensor 11.

Description

Sensor unit and detection device using the same

[0001] The present invention relates to a sensor unit and a detection device using the same.

[0002] A conventional sensor for measuring pressure fluctuations includes a sensor that has a tiltable cantilever that closes an opening of an air chamber formed in a box-shaped housing and detects pressure fluctuations inside and outside the air chamber using the cantilever (see, for example, Patent Document 1).Another known sensor is one that detects a change in electrical resistance in a sensor lever that is caused by a pressure difference between a sealed first space and a sealed second space, causing the sensor lever to bend (see, for example, Patent Document 2).

[0003] Patent No. 5674167 Patent No. 7113487

[0004] All conventional sensors form a sealed space such as an air chamber and detect target waves based on pressure fluctuations inside and outside the space caused by target waves such as vibration waves emitted from the target. For this reason, conventional sensors require the provision of a sealed space, which makes the structure more complicated.

[0005] The present invention has been made in consideration of the above points, and an object of the present invention is to provide a sensor unit and a detection device that can detect a detection target wave from a detection target with a simple configuration.

[0006] The sensor unit of the present invention is a sensor unit that detects vibration waves or sound waves emitted from a detection target as detection target waves, and has a sensor that is mounted on a substrate and whose electrical resistance changes in response to the displacement caused by receiving the detection target waves, and open spaces that communicate with the external environment are provided between the sensor and the detection target and on the back side of the sensor, which is located on the opposite side of the sensor from the detection target.

[0007] Furthermore, the detection device according to the present invention is a detection device that detects vibration waves or sound waves emitted from a detection target as detection target waves, and comprises a sensor unit that receives the detection target waves and a circuit section that measures the detection target waves based on the detection results obtained by the sensor unit, the sensor unit having a sensor that is provided on a substrate and whose electrical resistance changes in accordance with the displacement caused by receiving the detection target waves, and open spaces that communicate with the external environment are provided between the sensor and the detection target and on the back side of the sensor that is located on the opposite side of the sensor from the detection target.

[0008] According to the present invention, since no enclosed space is formed, the configuration can be simplified, and the detection target wave from the detection target can be detected by the sensor.

[0009] 1 is a schematic diagram showing the configuration of a detection device according to a first embodiment; an exploded perspective view showing the configuration of a sensor; a photograph showing the configuration of a sensor according to another embodiment; a cross-sectional view showing the cross-sectional configuration of a sensor; a schematic diagram showing the configuration of a detection device according to a second embodiment; an exploded perspective view showing the configuration of a sensor unit provided with a spacer; an exploded perspective view showing the configuration of a sensor unit provided with a plurality of spacers having different shapes; an exploded perspective view showing the configuration of a sensor unit provided with a plurality of columnar spacers; a schematic diagram showing the configuration of a detection device according to a third embodiment; a schematic diagram showing the configuration of a detection device according to a fourth embodiment; a schematic diagram showing the configuration of a detection device according to a fifth embodiment; a schematic diagram showing the configuration of a detection device according to another embodiment; a schematic diagram showing the configuration of a detection device according to a sixth embodiment; a schematic diagram showing the configuration of a detection device according to a seventh embodiment; a schematic diagram showing the configuration of a detection device according to an eighth embodiment; a schematic diagram showing the configuration of a detection device according to a ninth embodiment; a schematic diagram showing the configuration of a detection device according to a tenth embodiment; a schematic diagram showing the configuration of a detection device according to an eleventh embodiment; a schematic diagram showing the configuration of a detection device according to a twelfth embodiment; a schematic diagram showing the configuration of a detection device according to a thirteenth embodiment; a schematic diagram showing the configuration of a sensor unit according to a fourteenth embodiment; a schematic diagram showing the configuration of a detection device according to a fifteenth embodiment; and a schematic diagram showing the configuration of a sensor unit according to a sixteenth embodiment. FIG. 1 is a schematic diagram showing the configuration of a sensor unit according to another embodiment. FIG. 2 is a schematic diagram for explaining the arrangement of a sensor unit, a speaker, and a vibrator used in a verification test. FIG. 3 is a graph showing the relationship between output voltage and frequency obtained from the detection results of the sensor. FIG. 4 is a graph showing the relationship between frequency and sensitivity. FIG. 5 is a graph showing the relationship between output voltage and frequency when the distance between the sensor and the speaker is changed. FIG. 6 is a graph showing the relationship between output voltage and frequency when a partition plate is appropriately inserted between the sensor and the speaker. FIG. 7 is a graph showing the relationship between sensor output and frequency when a vibrator is used.

[0010] An embodiment of the present invention will be described in detail below with reference to the drawings. In the following description, the same components are designated by the same reference numerals, and duplicated descriptions will be omitted.

[0011] 1 is a schematic diagram showing the configuration of a detection device 100a according to the first embodiment. The detection device 100a detects, for example, sound waves or vibration waves emanating from inside a detection target 200a as detection target waves W, and presents the obtained detection results as predetermined data such as a waveform.

[0012] The detection object 200a is not particularly limited as long as it emits sound waves or vibration waves that propagate through space, and may be, for example, a living organism such as a human, a non-human animal, or a plant, or a structure such as a pillar of a building, an indoor or outdoor wall of a building, a road, a bridge, a dam, an embankment, or a tunnel.

[0013] When the detection target 200a is a living organism, the detection device 100a detects, for example, various sound waves and vibration waves generated within the body, such as blood flow in blood vessels and the heart, and air flow in the trachea and lungs, as detection target waves W. In addition, the detection device 100a can detect, as detection target waves W, photoacoustic waves (elastic waves) emitted from within the living organism when the living organism is irradiated with infrared rays or far-infrared rays from a wave source (not shown). Note that an embodiment for detecting photoacoustic waves will be described later with reference to FIG. 15 .

[0014] Furthermore, when the detection target 200a is a structure, the detection device 100a can detect as detection target waves W various sound waves and vibration waves generated within the structure, such as breaking sounds, vibrations, and operating sounds.

[0015] The detection device 100a includes a sensor unit 10a that detects a detection target wave W emitted by a detection target 200a, and a circuit section 30 that performs signal processing, arithmetic processing, etc. on the detection target wave W obtained from the sensor unit 10a. The sensor unit 10a includes a substrate 12 having an opening 121, and a sensor 11 provided in the area of ​​the opening 121. The sensor 11 is displaced when it receives the detection target wave W, and its electrical resistance changes in response to the displacement.

[0016] In the sensor unit 10a, no sealed space is formed between the sensor 11 and the detection target 200a, and an open space ER1 that communicates with the external environment is provided. In addition, in the sensor unit 10a, no sealed space is formed on the back side of the sensor 11, which is located on the opposite side of the detection target 200a of the sensor 11, and an open space ER2 that communicates with the external environment is provided.

[0017] In the sensor unit 10a, the sensor 11 receives the detection target wave W generated from the detection target 200a through the open space ER1 and the opening 121, and outputs a change in electrical resistance generated in the sensor 11 to the circuit section 30. The circuit section 30 generates data indicating a change in the intensity of the detection target wave W based on the change in electrical resistance generated by the sensor 11.

[0018] In the first embodiment, the method of positioning the sensor unit 10a on the detection target 200a by providing an open space ER1 that communicates with the external environment without providing an enclosed space between the sensor 11 and the detection target 200a is not particularly limited. For example, the sensor unit 10a may be provided on a support portion (not shown), and the support portion may be used to position the sensor unit 10a by providing the open space ER1 between the sensor unit 10a and the detection target 200a. Alternatively, the user may hold the sensor unit 10a and position the sensor unit 10a by providing the open space ER1 between the sensor unit 10a and the detection target 200a.

[0019] The circuit section 30 includes a control section 31, a detection circuit 32, and a calculation section 33, and the control section 31 comprehensively controls the circuit section 30. The detection circuit 32 measures the change in electrical resistance obtained by the sensor 11 and outputs the obtained measurement result to the calculation section 33 as the detection result of the sensor unit 10a. The calculation section 33 calculates, from the measurement result obtained by the detection circuit 32, data indicating the change in intensity of the detection target wave W, data indicating the state of the detection target 200a by converting the change in intensity of the detection target wave W into other indices, and the like.

[0020] For example, the calculation unit 33 can convert the change in intensity of the wave W to be detected by the sensor unit 10a into another index by using a data table that pre-associates the relationship between the change in intensity of the wave W to be detected and a predetermined index, or a learning model that has learned the relationship between the change in intensity of the wave W to be detected and a predetermined index.

[0021] (1-2) Configuration of Sensor Unit Next, the configuration of the sensor unit 10a will be described. The substrate 12 on which the sensor 11 is provided is a plate-like member having a predetermined outer shape, such as a quadrilateral or circular shape, and is formed, for example, from a silicon or plastic member. An opening 121 is formed through the thickness of the substrate 12, and the sensor 11 is fixed to the back surface of the substrate 12 so as to be exposed from the area of ​​the opening 121.

[0022] The substrate 12 according to this embodiment is disposed on the surface of the detection target 200a in a non-contact manner, and forms an open space ER1 communicating with the external environment between the detection target 200a and the substrate 12. The substrate 12 is configured so that there is nothing between the detection target 200a and the sensor 11 that blocks the detection target wave W from the detection target 200a, and the detection target wave W from the detection target 200a passes through the open space ER1 and the opening 121 and reaches the sensor 11 directly.

[0023] Next, the configuration of sensor 11 will be described. Fig. 2A is an exploded perspective view showing the configuration of sensor 11, and Fig. 3 is a cross-sectional view showing the cross-sectional configuration of sensor 11. Sensor 11 has a fixing member 111 having stepped openings 111A and 111B inside, and a sensor substrate 112 that is fitted into and fixed in opening 111B of fixing member 111. The front surface of fixing member 111 is fixed to the back surface of substrate 12 such that opening 111A on the front surface side communicates with opening 121 (Fig. 1) in substrate 12.

[0024] The fixing member 111 has an opening 111A formed on the front surface side and having an opening area smaller than that of an opening 111B on the rear surface side, and an opening 111B formed on the rear surface side and having an opening area larger than that of the opening 111A on the front surface side. In this embodiment, the outer shapes of the openings 111A and 111B are formed in the same quadrilateral shape, the centers of the openings 111A and 111B are formed to coincide with each other, and a step is formed between the openings 111A and 111B.

[0025] As shown in Fig. 3, the sensor substrate 112 is fitted into the opening 111B of the fixing member 111 and is positioned by being engaged with a step formed between the openings 111A and 111B. As shown in Fig. 2A, the sensor substrate 112 has a configuration in which a silicon substrate 113, an insulating layer 114, a silicon layer 115, a piezoresistive layer 116, and a metal layer 117 are laminated together. The sensor substrate 112 has a rectangular wave-receiving section 118 at its center, which is composed of the silicon layer 115 and the piezoresistive layer 116. A frame 119, which is composed of a laminate of the silicon substrate 113, the insulating layer 114, the silicon layer 115, the piezoresistive layer 116, and the metal layer 117, is provided around the wave-receiving section 118.

[0026] Only one side of the wave receiving unit 118 is formed integrally with the frame 119 and serves as a fixed end, and notches 51a are formed along the other three sides, which serve as free ends spaced apart from the frame 119. In this way, the wave receiving unit 118 is surrounded by the frame 119 and has a cantilevered configuration with only one side fixed to the frame 119. A sensing portion having the configuration of a cantilevered plate-like wave receiving unit 118 is generally called a cantilever.

[0027] The fixed end of the wave receiving unit 118 has a plurality of band-shaped beams 41 to 44, and is connected to the frame 119 via these beams 41 to 44. The beams 41 and 44 are located on the outer periphery of the wave receiving unit 118, and the beams 42 and 43 are provided so as to be sandwiched between the beams 41 and 44 located on the outer periphery. The beams 42 and 43 are adjacent to each other with a notch 52 interposed therebetween.

[0028] A beam portion 41 located on one outer periphery side and a beam portion 42 adjacent to said beam portion 41 form a pair, and a beam portion 43 located on the other outer periphery side and a beam portion 44 adjacent to said beam portion 43 form a pair. A rectangular protrusion 45 is provided between the pair of beam portions 41 and 42, protruding from the frame 119 in the surface direction of the sensor substrate 112. Furthermore, a rectangular protrusion 46 is provided between the beam portions 43 and 44, protruding from the frame 119 in the surface direction of the sensor substrate 112.

[0029] The protrusions 45, 46 are composed of a silicon layer 115 and a piezoresistive layer 116, one side of which is integrally formed with the frame 119, and the other three sides of which are connected to the frame 119 are spaced apart from the wave receiving section 118 via a U-shaped notch 51b.

[0030] In this way, one side (the lower left side) of the wave receiving unit 118 on which the beams 41 to 44 are provided is connected to the frame 119 via the beams 41 to 44, forming a fixed end. At the same time, the three sides of the wave receiving unit 118 on which the beams 41 to 44 are not provided are separated from the frame 119 via the notches 51a, and are also separated from the protrusions 45 and 46 via the notches 51b.

[0031] The notch 51a that separates the receiving portion 118 and the frame 119, the notch 51b that separates the protrusions 45, 46 and the receiving portion 118, and the notch 52 that separates the adjacent central beam portions 42, 43 are each formed to a width of, for example, approximately 0.02 μm to 10 μm.

[0032] Furthermore, an insulating groove 53 is provided between the metal layer 117 and the piezoresistive layer 116 and the beams 41, 44 on the fixed end side where the wave-receiving unit 118 is fixed in a cantilever structure, and an insulating groove 54 is provided in the center of the free end side of the wave-receiving unit 118. The insulating grooves 53, 54 are provided to electrically insulate the metal layer 117 and the piezoresistive layer 116 on the frame 119 from the beam 41 side to the beam 44 side on the left and right, and two electrodes 47, 48 are formed on the metal layer 117 and the piezoresistive layer 116 of the frame 119. In this case, the electrodes 47, 48 are each formed in a U-shape and are arranged so that the paired ends of their tips face each other with the insulating grooves 53, 54 interposed therebetween.

[0033] The piezoresistive layer 116 on one beam 41 is connected to the piezoresistive layer 116 on one electrode 47 of the frame 119, and the piezoresistive layer 116 on the other beam 44 is connected to the piezoresistive layer 116 on the other electrode 48 of the frame 119. The adjacent central beams 42 and 43 are electrically insulated from the electrodes 47 and 48 of the frame 119 by an insulating groove 53. The piezoresistive layer 116 forms a substantially U-shaped conductive path that runs from one beam 41 electrically connected to one electrode 47 through the wave-receiving unit 118 to the other beam 44 electrically connected to the other electrode 48. Therefore, the electrical resistance of the wave-receiving unit 118 can be determined by measuring the current between the electrodes 47 and 48.

[0034] As shown in FIG. 3, openings 113A, 114A, and 117A having approximately the same opening area as opening 111A formed on the surface side of fixing member 111 are formed in silicon substrate 113, insulating layer 114, and metal layer 117, respectively, and receiving sections 118 are arranged within the areas of openings 113A, 114A, and 117A.

[0035] The wave receiving section 118 has a silicon layer 115 and a piezoresistive layer 116 on the fixed end side that are connected to the silicon layer 115 and the piezoresistive layer 116 of the frame 119, respectively, and the silicon layer 115 and the piezoresistive layer 116 of the frame 119 are fixed by being sandwiched between the stacked silicon substrate 113 and insulating layer 114 and the metal layer 117.

[0036] As a result, the wave receiving unit 118 is deformable with its free end elastically bending in the plane normal direction of the wave receiving unit 118 (the up and down direction in the figure) with the fixed ends of the beams 41 to 44 as base points. The wave receiving unit 118 bends with the fixed ends of the beams 41 to 44 as base points, thereby increasing or decreasing the electrical resistance of the piezoresistive layer 116. The wave receiving unit 118 receives detection target waves W from the detection target 200a that have passed through the opening 111A of the fixing member, the opening 113A of the silicon substrate 113, and the opening 114A of the insulating layer 114, and bends in accordance with the strength of the detection target waves W.

[0037] The sensor 11 can detect the strength of the wave W to be detected by measuring the resistance between the electrodes 47 and 48, based on changes in the receiving section 118 caused by the strength of the wave W to be detected.

[0038] In this embodiment, the sensor 11 is positioned so that the silicon substrate 113 located on the front side of the sensor 11 faces the detection target 200a, but the sensor 11 may also be positioned so that the metal layer 117 located on the back side of the sensor 11 faces the detection target 200a, and even in this case, the detection target wave W can be detected by the wave receiving unit 118.

[0039] In the above-described embodiment, the sensor 11 is described as having the wave receiving unit 118 fixed to the frame 119 in a cantilever structure by the four beams 41 to 44, but the present invention is not limited to this. For example, as shown in FIG. 2B , a sensor 11a may be used in which the wave receiving unit 118 is fixed to the frame 119 in a cantilever structure by the two beams 42 and 43.

[0040] In this case, only one side of the wave receiving unit 118 is connected to the frame 119 via the adjacent beams 42 and 43 via a notch 52, forming a fixed end, and notches 51a are formed along the other three sides, which form free ends spaced apart from the frame 119 by the notches 51a. The wave receiving unit 118 is surrounded by the frame 119 and has a cantilevered configuration with only one side fixed to the frame 119. Although not shown, two electrodes 47 and 48 are also formed on the sensor substrate 112a of the sensor 11a. In the sensor 11a shown in FIG. 2B, the width of the notch 51a is 1 μm (denoted as "1 μm cap" in the figure).

[0041] (1-3) Method for Fabricating Sensor The method for fabricating the sensor 11 is as follows. First, an SOI (Silicon On Insulator) substrate is prepared, in which a silicon substrate 113, an insulating layer 114, and a silicon layer 115 are stacked. The thicknesses of the silicon substrate 113, the insulating layer 114, and the silicon layer 115 are, for example, 300 μm, 0.4 μm, and 0.08 μm, in this order. The silicon layer 115 of this SOI substrate is doped, and a piezoresistive layer 116 is formed on the surface of the silicon layer 115. After forming a metal layer 117 that serves as an electrode on the piezoresistive layer 116, the metal layer 117, the piezoresistive layer 116, and the silicon layer 115 are sequentially etched to form an opening 117A and notches 51a, 51b, and 52.

[0042] Furthermore, the metal layer 117 and the piezoresistive layer 116 are etched to form insulating grooves 53 and 54 in the frame 119, thereby forming electrodes 47 and 48 on the frame 119. Finally, the silicon substrate 113 and the insulating layer 114 are etched from the opposite surface to form openings 113A and 114A. In this way, the sensor substrate 112 having the wave receiving portion 118 is formed.

[0043] (1-4) Actions and Effects In the above configuration, the sensor unit 10a has the sensor 11, whose electrical resistance changes in response to displacement of the wave receiving section 118 caused by receiving detection target waves W from the detection target 200a, in the region of the opening 121 of the substrate 12. The sensor unit 10a has open spaces ER1 and ER2 that communicate with the external environment between the sensor 11 and the detection target 200a and on the back side of the sensor 11 located on the opposite side of the detection target 200a from the sensor 11, without providing any sealed space.

[0044] The sensor unit 10a is placed relative to the detection target 200a with an open space ER1 provided between the sensor 11 and the detection target 200a, and the detection target wave W transmitted from the detection target 200a via the open space ER1 is detected by the sensor 11. As described above, the sensor unit 10a does not have an enclosed space formed therein, and therefore can have a simple configuration and can detect the detection target wave W from the detection target 200a with the sensor 11.

[0045] Furthermore, the sensor unit 10a detects the target waves W by measuring the electrical resistance that changes in response to the displacement of the receiving section 118 caused by receiving the target waves W, and is therefore capable of detecting the target waves W from low frequencies to the ultrasonic range, which are difficult to detect with commonly available microphones.

[0046] 2. Second Embodiment In the above-described first embodiment, the method for disposing the sensor unit 10a in a state where an open space ER1 communicating with the external environment is provided between the sensor 11 and the detection target 200a, without providing an enclosed space, is not particularly limited, and may be realized by various methods. Here, the case where a spacer is used will be described below.

[0047] 4 is a schematic diagram showing the configuration of a detection device 100b according to the second embodiment. The detection device 100b according to the second embodiment differs from the detection device 100a according to the first embodiment in that a spacer 9a is provided in the sensor unit 10b, but the other configurations are the same as those of the first embodiment. Therefore, to avoid duplication of explanation, the following description will focus on the sensor unit 10b.

[0048] In the sensor unit 10b, a spacer 9a is provided on the substrate 12, and the spacer 9a is brought into contact with the surface of the detection target 200a. The spacer 9a is formed, for example, from a plastic member or the like, and is fixed to a partial region of the surface of the substrate 12 that faces the detection target 200a. By bringing the spacer 9a into contact with the surface of the detection target 200a, the sensor unit 10b forms a gap between the substrate 12 and the detection target 200a that is equal to the thickness of the spacer 9a.

[0049] As a result, in the sensor unit 10b, the substrate 12 does not come into contact with the detection target 200a, and the space between the sensor 11 and the detection target 200a is not an enclosed space, but an open space ER1 that communicates with the external environment is formed.

[0050] The spacer 9a has a configuration in which a number of rectangular parallelepipeds are connected together to form a U-shape, as shown in FIG. 5A, and is fixed to the surface of the substrate 12 so that the central opening 9a1 communicates with the opening 121 of the substrate 12.

[0051] In this embodiment, the case where U-shaped spacers 9a are provided on the surface of the substrate 12 has been described, but the present invention is not limited to this, and for example, as shown in Fig. 5B, rectangular parallelepiped spacers 9b and columnar spacers 9c may be provided on the surface of the substrate 12. In another embodiment, as shown in Fig. 5C, a configuration may be adopted in which a plurality of columnar spacers 9d are disposed at each corner of the substrate 12.

[0052] Even in the above configuration, the sensor unit 10b can be easily placed relative to the detection target 200a with an open space ER1 provided between the sensor 11 and the detection target 200a by, for example, the spacer 9a, and the detection target wave W can be detected by the sensor 11 from the detection target 200a via the open space ER1. Therefore, the sensor unit 10b can have a simple configuration because no sealed space is formed, and the detection target wave W from the detection target 200a can be detected by the sensor 11.

[0053] In this embodiment, instead of the above-described spacers 9a, 9b, 9c, and 9d, for example, a wave source 23, which will be described later with reference to FIG. 16, may be provided as a spacer.

[0054] 6 is a schematic diagram showing the configuration of a detection device 100c according to a third embodiment. The detection device 100c according to the third embodiment differs from the detection device 100b according to the second embodiment in that the sensor unit 10c is provided with an anti-vibration unit 15, but the other configurations are the same as those of the first and second embodiments. Therefore, to avoid duplication of explanation, the following description will focus on the sensor unit 10c.

[0055] In the sensor unit 10c, a vibration-isolating part 15, such as a porous sponge member or an air cushion formed by filling a bag with air and sealing it, is provided on the surface of the substrate 12. The vibration-isolating part 15 is disposed opposite the detection target 200a and abuts against the surface of the detection target 200a, thereby also functioning as a spacer and forming a gap between the substrate 12 and the detection target 200a.

[0056] As a result, the sensor unit 10c is positioned so that the substrate 12 does not come into contact with the object to be detected 200a, and the space between the sensor 11 and the object to be detected 200a is not an enclosed space, but rather has an open space ER1 that is connected to the external environment.

[0057] Even in the above configuration, the sensor unit 10c can be easily placed relative to the detection target 200a with an open space ER1 provided between the sensor 11 and the detection target 200a by, for example, the vibration isolation unit 15, and the detection target wave W can be detected by the sensor 11 from the detection target 200a via the open space ER1. Therefore, the sensor unit 10c can have a simple configuration because no sealed space is formed, and the detection target wave W from the detection target 200a can be detected by the sensor 11.

[0058] In addition, the sensor unit 10c can absorb vibrations generated in the detection target 200a by the vibration-isolating section 15. Therefore, the sensor unit 10c can suppress displacement of the sensor 11 due to vibrations of the detection target 200a, and can detect the detection target wave W, which is emitted from the detection target 200a and propagates through the open space ER1, by the sensor 11.

[0059] In this embodiment, the case where an anti-vibration section 15 is provided on the substrate 12 has been described, but the present invention is not limited to this. For example, a configuration in which a spacer 9a is provided between the anti-vibration section 15 and the substrate 12 may also be used, or the anti-vibration section 15 may be provided between the spacer 9a that abuts the detection object 200a and the substrate 12.

[0060] 7 is a schematic diagram showing the configuration of a detection device 100d according to a fourth embodiment. The detection device 100d according to the fourth embodiment differs from the detection device 100a according to the first embodiment in that a dust cover 16 is provided on the sensor unit 10d, but the other configuration is the same as that of the first embodiment. Therefore, to avoid duplication, the following description will focus on the sensor unit 10d.

[0061] The sensor unit 10d has a dust cover 16 provided on the substrate 12 so as to surround the sensor 11 exposed from the opening 121 of the substrate 12, and the dust cover 16 can prevent dust (e.g., dust floating in the external environment, dust caused by the detection target 200a, etc.) from accumulating on the surface of the sensor 11.

[0062] The dust cover 16 includes a frame portion 16a fixed to the substrate 12 and a mesh portion 16c having a mesh structure provided to cover an opening surrounded by the frame portion 16a. The frame portion 16a is, for example, a quadrilateral wall portion arranged along the outer periphery of the substrate 12. The mesh portion 16c forms an open space ER1 that can communicate with the external environment, and has a plurality of through holes formed therein that prevent dust from entering the open space ER1.

[0063] In the above configuration, similarly to the first embodiment described above, the sensor unit 10d is placed relative to the detection target 200a with an open space ER1 provided between the sensor 11 and the detection target 200a, and the detection target wave W can be detected from the detection target 200a via the open space ER1 by the sensor 11. Therefore, the sensor unit 10d can have a simple configuration since no enclosed space is formed, and the detection target wave W from the detection target 200a can be detected by the sensor 11.

[0064] In addition, sensor unit 10d is equipped with dustproof cover 16 having a mesh structure that captures dust from outside, and therefore dustproof cover 16 can prevent dust from entering open space ER1 from the external environment, thereby preventing poor sensitivity of sensor 11 due to dust. Furthermore, sensor unit 10d is equipped with dustproof cover 16 that covers sensor 11, and therefore dustproof cover 16 also serves as a protective cover, and can prevent physical impact from being applied to the surface of sensor 11 from the outside.

[0065] In this embodiment, the dustproof cover 16 has been described as having a mesh structure with a plurality of through holes formed in a regular pattern, but the present invention is not limited to this, and a dustproof cover with a single through hole may be used as long as it is configured to capture dust from outside while forming the open space ER1. Furthermore, the dustproof cover 16 may be provided on the back side of the sensor 11, in which case it also serves as a protective cover to protect the back side of the sensor 11.

[0066] 8A is a schematic diagram showing the configuration of a detection device 100e1 according to a fifth embodiment. The detection device 100e1 according to the fifth embodiment differs from the detection device 100a according to the first embodiment described above in the shape of the substrate 17a of the sensor unit 10e1, but the other configuration is the same as that of the first embodiment. Therefore, to avoid duplication of explanation, the following description will focus on the sensor unit 10e1.

[0067] Sensor unit 10e1 is provided with substrate 17a, which has a spherical crown-shaped outer shape and curved walls with a predetermined thickness. Substrate 17a has opening 121 formed in the bottom, and opening 121a, which has a larger diameter than opening 121, formed in the ceiling opposite the bottom, forming a spherical crown-shaped hollow space that is connected from large-diameter opening 121a to small-diameter opening 121. Substrate 17a is made of, for example, a plastic material.

[0068] The substrate 17a is provided with the sensor 11 exposed in the area of ​​an opening 121 formed in the bottom, and the sensor 11 is surrounded by walls. The walls of the substrate 17a are curved so that the diameter gradually decreases from the opening 121a in the ceiling toward the opening 121 in the bottom. A reflector 17d, which is disposed corresponding to the substrate 11, is held by a support (not shown) within an open region ER1 surrounded by the walls of the substrate 17a. The curved walls of the substrate 17a reflect detection target waves W from the detection target 200a toward the reflector 17d. The reflector 17d reflects the detection target waves W received from the wall of the substrate 17a toward the sensor 11 disposed opposite the reflector 17d, focusing the detection target waves W on the sensor 11.

[0069] In the above configuration, similarly to the first embodiment described above, the sensor unit 10e1 is placed relative to the detection target 200a with an open space ER1 provided between the sensor 11 and the detection target 200a, and the detection target wave W can be detected from the detection target 200a via the open space ER1 by the sensor 11. Therefore, the sensor unit 10e1 can have a simple configuration since no enclosed space is formed, and the detection target wave W from the detection target 200a can be detected by the sensor 11.

[0070] In addition, the sensor unit 10e1 has a substrate 17a with walls formed so as to surround the sensor 11, and a reflector 17d, and the detection target wave W is reflected sequentially via the walls and the reflector 17d, so that the detection target wave W can be focused on the sensor 11. This allows the sensor unit 10e1 to further detect the detection target wave W using the sensor 11. Furthermore, in the sensor unit 10e1, because the detection target wave W is reflected many times, the passing area of ​​the detection target wave W can be narrowed, and as a result, the substrate 17a and the like can be made smaller.

[0071] In the fifth embodiment described above, the sensor unit 10e1 is described, in which a reflector 17d is provided in the open space ER1 surrounded by the walls of the substrate 17a. However, the present invention is not limited to this. Fig. 8B is a schematic diagram showing the configuration of a detection device 100e2 having a sensor unit 10e2 with another structure for focusing the test target wave W. As shown in Fig. 8B, in the sensor unit 10e2, the sensor 11 is held by a support (not shown) near the center of the open space ER1 surrounded by the walls of the substrate 17b, and the test target wave W reflected by the walls is focused onto the sensor 11. In this case, the sensor 11 is disposed in the area of ​​the opening 121a in the substrate 17b, and the test target wave W from the test target 200a is received on both the front and back surfaces of the sensor 11.

[0072] 9 is a schematic diagram showing the configuration of a detection device 100f according to a sixth embodiment. The detection device 100f according to the sixth embodiment differs from the detection device 100a according to the first embodiment in that a protective cover 18 is provided on the sensor unit 10f, but the other configuration is the same as that of the first embodiment. Therefore, to avoid duplication of explanation, the following description will focus on the sensor unit 10f.

[0073] Sensor unit 10f is provided with a box-shaped protective cover 18 on the back side of substrate 12 to protect the back side of sensor 11. Protective cover 18 has through holes (not shown) provided at predetermined positions, which connect the internal space surrounded by protective cover 18, substrate 12, and sensor 11 with the external environment, and surrounds and protects the back side of sensor 11 while forming an open space ER2 on the back side of sensor 11 that is connected to the external environment.

[0074] The protective cover 18 according to this embodiment includes a side portion 18a provided on the substrate 12 so as to surround the rear surface of the sensor 11, and a bottom portion 18b that covers the area surrounded by the side portion 18a. The protective cover 18 has through-holes (not shown) formed in the side portion 18a and / or the bottom portion 18b that communicate with the external environment. This forms an open space ER2 surrounded by the protective cover 18 on the rear surface of the sensor 11.

[0075] The side portion 18a may have a structure in which through-holes are formed in a wall-like member, a structure formed by a plurality of columnar members, etc. The bottom portion 18b may have a structure in which through-holes are formed in a plate-like member, a mesh structure in which a mesh is formed, a structure formed by a lattice-like member, etc.

[0076] In the above configuration, similarly to the first embodiment described above, the sensor unit 10f is placed relative to the detection target 200a with an open space ER1 provided between the sensor 11 and the detection target 200a, and the detection target wave W can be detected from the detection target 200a via the open space ER1 by the sensor 11. Therefore, the sensor unit 10f can have a simple configuration since no enclosed space is formed, and the detection target wave W from the detection target 200a can be detected by the sensor 11.

[0077] In addition, the sensor unit 10f is provided with a protective cover 18 that surrounds the back side of the sensor 11, and the protective cover 18 can prevent physical impacts from being directly applied to the back side of the sensor 11, thereby preventing damage to the sensor 11. The protective cover 18 may also serve as a dust cover that prevents dust from entering the back side of the sensor 11.

[0078] 10 is a schematic diagram showing the configuration of a detection device 100g according to a seventh embodiment. The detection device 100g according to the seventh embodiment differs from the detection device 100f according to the sixth embodiment in that a side sensor 11b is provided in a sensor unit 10g, but the other configuration is the same as that of the sixth embodiment. Therefore, to avoid duplication, the following description will focus on the sensor unit 10g.

[0079] In the sensor unit 10g, the side sensor 11b is provided on the substrate 12 so that the side sensor 11b protrudes between the detection target 200a and the sensor 11. This allows the sensor unit 10g to detect noise and / or detection target waves W from the side direction between the detection target 200a and the sensor 11 by the side sensor 11b.

[0080] 2 and 3, the side sensor 11b receives the detection target waves W, causing a displacement in the wave receiving section 118, and the electrical resistance changes in response to the displacement. The side sensor 11b is provided on the substrate 12 so that the wave receiving section 118 is disposed in the open space ER1 between the detection target 200a and the sensor 11. Note that the configuration of the side sensor 11b is the same as that of the sensor 11, and therefore a description thereof will be omitted here to avoid duplication.

[0081] The side sensor 11b is connected to a detection circuit 32 of the circuit unit 30. The detection circuit 32 detects the electrical resistance that changes in response to the displacement of the wave receiving portion 118 of the side sensor 11b, which occurs when the side sensor 11b receives noise and / or detection target waves W.

[0082] The detection circuit 32 outputs the measurement results of the electrical resistance at the sensor 11 and the measurement results of the electrical resistance at the side sensor 11b to the calculation unit 33. The calculation unit 33 compares the measurement results at the sensor 11 with the measurement results at the side sensor 11b to calculate the detection target wave W in which noise generated in the external environment is suppressed.

[0083] In the above configuration, the sensor unit 10g is placed relative to the detection target 200a with an open space ER1 provided between the sensor 11 and the detection target 200a, and the detection target wave W can be detected from the detection target 200a via the open space ER1 by the sensor 11. Therefore, the sensor unit 10g can have a simple configuration since no enclosed space is formed, and the detection target wave W from the detection target 200a can be detected by the sensor 11.

[0084] In addition, the sensor unit 10g has a side sensor 11b disposed in the open space ER1 between the sensor 11 and the detection target 200a, and the side sensor 11b detects noise or the detection target wave W from the side direction. The circuit section 30 can measure the detection target wave W with noise suppressed based on the comparison result between the detection result of the sensor 11 and the detection result of the side sensor 11b.

[0085] 7 or the protective cover 18 shown in FIG. 9, similar to the sensor 11. In the present embodiment, the side sensor 11b is provided on the open space ER1 side between the inspection target 200a and the substrate 12. However, the present invention is not limited to this. For example, the side sensor 11b may be provided on the open space ER2 side, which is the rear side of the sensor 11. In this case, the side sensor 11b may be fixed to the substrate 12 and disposed on the open space ER2 side, or the side sensor 11b may be fixed to the protective cover 18 and disposed on the open space ER2 side.

[0086] 8. Eighth Embodiment In the seventh embodiment described above, the case where the side sensor 11b is provided has been described. However, the present invention is not limited to this. For example, as shown in FIG. 11, another sensor 11c may be provided on the same plane as the sensor 11.

[0087] 11 is a schematic diagram showing the configuration of a detection device 100h according to an eighth embodiment. The detection device 100h according to the eighth embodiment differs from the detection device 100a according to the first embodiment in that a second sensor 11c is provided in the sensor unit 10h, but the other configurations are the same as those of the first embodiment. Therefore, to avoid duplication of explanation, the following description will focus on the sensor unit 10h.

[0088] In the sensor unit 10h, a second substrate 12c is provided at an end of the substrate 12. In Fig. 11, as an example, the end of the substrate 12c is connected to the end of the substrate 12 via a connecting member 20a, but the present invention is not limited to this, and the end of the substrate 12c may be connected directly to the end of the substrate 12.

[0089] The substrate 12c has the same configuration as the substrate 12 of the first embodiment described above, and the second sensor 11c is disposed in the opening 121 of the substrate 12c. The sensor 11c has the same configuration as the sensor 11 of the first embodiment described above, and its electrical resistance changes in response to displacement caused by receiving noise and / or the detection target wave W.

[0090] In the sensor unit 10h, the sensors 11 and 11c are arranged at a predetermined distance by the substrates 12 and 12c, so that, for example, when the detection target wave W emitted from the detection target 200a has directionality, the sensors 11 and 11c have different detection sensitivities for the detection target wave W. Furthermore, in the sensor unit 10h, when the sensor 11 detects the detection target wave W, the other sensor 11c can detect noise in the external environment.

[0091] The sensor 11c is connected to a detection circuit 32 of the circuit section 30, and the detection circuit 32 detects the electrical resistance that changes in response to the displacement of the wave receiving section 118 of the sensor 11c caused by receiving noise and / or the wave W to be detected.

[0092] The detection circuit 32 outputs the detection results of the electrical resistances of the sensors 11 and 11c to the calculation unit 33. The calculation unit 33 compares the detection results of the sensors 11 and 11c to calculate the detection target wave W in which noise generated in the external environment is suppressed.

[0093] In the above configuration, the sensor unit 10h not only achieves the same effects as the first embodiment described above, but also can detect the detection target wave W and noise propagating from the detection target 200a through the open space ER1 using multiple sensors 11, 11c, and therefore can measure the detection target wave W with suppressed noise based on the comparison result of the detection results of the sensors 11, 11c.

[0094] 12 is a schematic diagram showing the configuration of a detection device 100i according to a ninth embodiment. The detection device 100i according to the ninth embodiment differs from the detection device 100a according to the first embodiment described above in that a physical quantity sensor 19 is provided in the sensor unit 10a, but the other configuration is the same as that of the first embodiment. Therefore, to avoid duplication of explanation, the following description will focus on the sensor unit 10i.

[0095] The sensor unit 10i has a sensor holder 20b attached to an end of the substrate 12 via a connecting member 20a, and a physical quantity sensor 19 is attached to the sensor holder 20b. The physical quantity sensor 19 is a sensor that measures at least one physical quantity selected from the group consisting of temperature, pressure, luminous intensity, and magnetism. The physical quantity sensor 19 outputs the measurement result to the calculation unit 33 of the circuit unit 30.

[0096] The calculation unit 33 generates a measurement result that associates the detection target wave W with the physical quantity based on the detection result of the sensor 11 received via the detection circuit 32 and the measurement result of the physical quantity received from the physical quantity sensor 19.

[0097] In the present embodiment, a case has been described in which measurement results correlating the detection target wave W with a physical quantity are generated, but the present invention is not limited to this. For example, the calculation unit 33 may store in advance a data table in which the relationships between the intensity change of the detection target wave W detected by the sensor 11, the measurement results of the physical quantity measured by the physical quantity sensor 19, and the state of the detection target 200a are previously associated with each other, or a learning model that has learned the relationships between the intensity change of the detection target wave W detected by the sensor 11, the measurement results of the physical quantity measured by the physical quantity sensor 19, and the state of the detection target 200a. This allows the calculation unit 33 to estimate the state of the detection target 200a from the data table or the learning model based on the detection results of the sensor 11 and the measurement results of the physical quantity sensor 19.

[0098] In the above configuration, the sensor unit 10i not only achieves the same effects as the first embodiment described above, but also can detect the detection target wave W that propagates from the detection target 200a through the open space ER1, and can measure the physical quantity using the physical quantity sensor 19, so can measure the detection target wave W that reflects the physical quantity.

[0099] 10. Tenth Embodiment Figure 13 is a schematic diagram showing the configuration of a detection device 100j according to a tenth embodiment. The detection device 100j according to the tenth embodiment differs from the detection device 100a according to the first embodiment described above in that a spacer 9e and a sensor array 11j are provided in the sensor unit 10a, but the other configuration is the same as that of the first embodiment. Therefore, to avoid duplication of explanation, the following description will focus on the sensor unit 10j.

[0100] The sensor unit 10j has a sensor array 11j provided in an opening 121 of a substrate 12e. The sensor array 11j has a plurality of sensors 11e, 11f, 11g, ... arranged in a matrix, and each of the sensors 11e, 11f, 11g, ... detects a detection target wave W from a detection target 200a.

[0101] 2 and 3, and displacement occurs in the wave receiving section 118 when the wave W to be detected is received, and the electrical resistance changes in accordance with the displacement. In the sensor unit 10j, for example, when the wave W to be detected emitted from the detection target 200a has directionality, the sensors 11e, 11f, 11g, ... have different detection sensitivities for the wave W to be detected.

[0102] The sensors 11e, 11f, 11g, ... are connected to a detection circuit 32 of the circuit section 30, and output the detection results of each of the detected target waves W to the detection circuit 32. The detection circuit 32 measures the changes in electrical resistance obtained by the sensors 11e, 11f, 11g, ..., and outputs the measurement results obtained for each of the sensors 11e, 11f, 11g, ... to a calculation section 33 as the detection results of the sensor unit 10j.

[0103] The calculation unit 33 can estimate the location in the detection object 200a that emits the detection target wave W from the difference in detection sensitivity of the detection target wave W obtained for each of the sensors 11e, 11f, 11g, . . .

[0104] In the above configuration, the sensor unit 10j not only achieves the same effects as the first embodiment described above, but also outputs the detection results of the detection target wave W obtained from each of the sensors 11e, 11f, 11g, ... arranged in a matrix to the circuit section 30. As a result, the sensor unit 10j can cause the circuit section 30 to analyze the differences in detection sensitivity of the detection target wave W obtained from each of the sensors 11e, 11f, 11g, ..., thereby estimating the location in the detection target 200a from which the detection target wave W is emitted.

[0105] 11. Eleventh Embodiment In the above-described first to tenth embodiments, the case where the detection target wave W emitted from inside the detection target 200a is detected has been described, but the present invention is not limited to this. For example, as shown in Fig. 14, the detection target wave W generated on the surface of the detection target 200b may be detected. For example, if the detection target 200b is a structure or the like, sound waves or vibration waves generated due to changes in the state of the surface of the structure or the like, as well as sound waves or vibration waves reflected from the surface of the structure or the like, can be detected as the detection target wave W by the sensor unit 10a.

[0106] 12. Twelfth Embodiment Fig. 15 is a schematic diagram showing the configuration of a detection device 100k according to a twelfth embodiment. The detection device 100k according to the twelfth embodiment differs from the detection device 100a according to the first embodiment described above in that it is provided with a wave source 22 and a drive unit 35, and in that it is provided with a concentration calculation unit 33b instead of the calculation unit 33. The other configuration is the same as that of the first embodiment. Here, to avoid duplication of explanation, the following description will focus on the differences from the above-described embodiments.

[0107] In this case, the detection device 100k is a device capable of measuring photoacoustic waves and is capable of measuring the concentration of a predetermined component present in the detection target 200c. The outline of measuring the concentration of a predetermined component in the detection target 200c is as follows: When the detection target 200c is irradiated with light emitted by the wave source 22, molecules in the detection target 200c emit photoacoustic waves (elastic waves) due to the photoacoustic effect. The sensor unit 10a detects the photoacoustic waves generated from the detection target 200c. The circuit section 30b determines the concentration of the liquid in the detection target 200c according to changes in the intensity of the photoacoustic waves detected by the sensor unit 10a.

[0108] In this embodiment, the detection target 200c is a living body, and when the detection target 200c is irradiated with far-infrared light from the wave source 22, a photoacoustic wave is emitted from glucose in the blood flowing through the blood vessels 201 within the detection target 200c. In the detection device 100k, the sensor unit 10a detects the photoacoustic wave as a detection wave, and the circuit section 30b determines the blood glucose concentration in the blood vessels 201 based on the detection result.

[0109] The wave source 22 is, for example, a modulated light source, and is controlled by the drive unit 35. The wave source 22 outputs modulated light of far-infrared light (having a wavelength of about 10 μm) toward the detection target 200 c based on a control signal from the drive unit 35. In this embodiment, the wave source 22 is disposed so as to irradiate the detection target 200 c with far-infrared light from an oblique direction without contacting the detection target 200 c.

[0110] For example, the wave source 22 includes a far-infrared laser light source and a chopper unit, and the chopper unit operates under the control of the drive unit 35 to output intensity-modulated far-infrared light as modulated light. Pulsed light is output multiple times, for example, about five times, in one measurement. The intensity-modulated light is not limited to light whose output is completely blocked, such as pulsed light, and may be light modulated to reduce its intensity to a predetermined level (>0). Note that the wave source 22 may not include a chopper unit and may perform intensity modulation by turning the laser light source on and off at a predetermined cycle.

[0111] When modulated light from the wave source 22 is irradiated onto the detection target 200c and the far-infrared modulated light reaches the blood vessel 201, glucose in the blood absorbs the far-infrared light and expands instantaneously, generating a photoacoustic wave (elastic wave). This photoacoustic wave generates a displacement in the wave-receiving section 118 of the sensor unit 10a, changing the electrical resistance of this wave-receiving section 118.

[0112] When the sensor unit 10a detects a photoacoustic wave as a detection target wave W in the sensor 11, the sensor unit 10a outputs the detection result to the detection circuit 32. The detection circuit 32 measures the change in electrical resistance generated in the sensor 11 based on the detection result received from the sensor 11, and outputs the result to the concentration calculation unit 33b.

[0113] Here, since the higher the glucose concentration, the stronger the photoacoustic waves generated, the concentration calculation unit 33b can calculate the blood glucose concentration based on the electrical resistance that changes depending on the intensity of the photoacoustic waves. Note that the concentration calculation unit 33b can remove (reduce) noise and calculate the concentration with higher accuracy by synchronizing and associating the modulation pattern of the wave source 22 with the change in electrical resistance caused by the sensor unit 10a.

[0114] Even in the above configuration, the sensor unit 10a places the sensor 11 relative to the detection target 200c with an open space ER1 provided between the sensor 11 and the detection target 200c. When far-infrared light is irradiated onto the detection target 200c from the wave source 22, the sensor unit 10a detects photoacoustic waves emitted from a predetermined component 202 (e.g., glucose) in the detection target 200c as detection target waves W via the sensor 11 through the open space ER1. Therefore, the sensor unit 10a can be configured simply because no enclosed space is formed, and the detection target waves W from the detection target 200c can be detected by the sensor 11.

[0115] In addition, in the detection device 100k, the electrical resistance of the sensor 11 changes depending on the strength of the wave W to be detected, and this change in electrical resistance is detected by the detection circuit 32, so that the concentration calculation unit 33b can determine the concentration of a specified component 202 based on the change in electrical resistance.

[0116] 13. Thirteenth Embodiment In the above-described twelfth embodiment, the case where the wave source 22 is disposed out of contact with the detection target 200c has been described. However, the present invention is not limited to this. As shown in FIG. 16 , the wave source 23 may be disposed in contact with the detection target 200c.

[0117] For example, the wave source 23 may be a modulated light source that irradiates far-infrared light as in the twelfth embodiment described above, but the following description will be given assuming that the wave source 23 is an ultrasonic source that emits ultrasonic waves. In this case, the sensor unit 10a can detect, with the sensor 11, the reflected waves reflected by a predetermined portion 203 in the detection object 200c as detection target waves W when ultrasonic waves are irradiated from the wave source 23 to the detection object 200c. In the detection device 100l, the electrical resistance of the sensor 11 changes depending on the strength of the detection target waves W, and the detection circuit 32 detects this change in electrical resistance, allowing the calculation unit 33c to determine the state of the predetermined portion 203 based on the change in electrical resistance.

[0118] In this specification, modulated light sources that irradiate modulated far-infrared light may be used as the wave sources 22 and 23. Alternatively, for example, thermal light sources that irradiate intensity-modulated infrared light in response to heat generation according to a modulation pattern may be used as the wave sources 22 and 23.

[0119] 14. Fourteenth Embodiment Fig. 17 is a schematic diagram showing the configuration of a sensor unit 10l according to a fourteenth embodiment. Fig. 17 is a schematic diagram in which the side configuration of the sensor unit 10l is shown in the upper diagram, the shape of the outer surface of the fixing tape 25 provided on the sensor unit 10l is shown in the lower diagram, and the configurations of the fixing tape 25 correspond to each other in the upper and lower diagrams.

[0120] 16 in that the wave source 23 is provided on the substrate 12, that a spacer 9e is provided on the substrate 12, and that a fixing tape 25 is provided to fix the substrate 12 to the detection target 200c, but the other configurations are the same. In order to avoid duplication of explanation, the following description will focus on the differences from the above-mentioned embodiments.

[0121] In this case, a wave source 23 is fixed to the surface of the substrate 12 that faces the detection target 200c. Furthermore, the substrate 12 is provided with spacers 9e, for example, at each of the four corners of each of the four sides, and each spacer 9e abuts against the detection target 200c, thereby forming a gap between the substrate 12 and the detection target 200c, the gap being equal to the thickness of the spacer 9e. While the present embodiment has been described with reference to a case where the spacer 9e is in the shape of a square pillar, the present invention is not limited to this, and spacers of various other shapes, such as the spacers 9a, 9b, 9c, and 9d shown in FIGS. 5A, 5B, and 5C, may also be used.

[0122] The sensor unit 10l is arranged so that the wave source 23 is in contact with the surface of the detection target 200c by providing a spacer 9e of a predetermined height on the substrate 12, while the substrate 12 does not come into contact with the detection target 200c, and the space between the sensor 11 and the detection target 200c is not an enclosed space but an open space ER1 communicating with the external environment is formed. Note that, although the wave source 23 in contact with the detection target 200c is used here, a wave source 22 arranged in a non-contact manner may also be used.

[0123] In addition, the sensor unit 10l has a fixing tape 25 that surrounds the periphery of the substrate 12, and the spacer 9e is fixed in contact with the surface of the detection target 200c by the fixing tape 25. The fixing tape 25 is a detachable adhesive tape that is adhered to the back surface of the substrate 12 and the surface of the detection target 200c, and positions the substrate 12 on the detection target 200c so as to have an open space ER1.

[0124] The fixing tape is circular and has a U-shaped cutout 25a formed therein. The sensor 11 and the wave source 23 are disposed in the cutout 25a, forming open spaces ER1 and ER2 on the front and back sides of the sensor 11, respectively.

[0125] In the above configuration, the sensor unit 10l is placed relative to the detection target 200c with an open space ER1 provided between the sensor 11 and the detection target 200c, and the photoacoustic waves generated from the detection target 200c are detected by the sensor 11 via the open space ER1 as detection target waves W. Therefore, the sensor unit 10l can be configured simply because no enclosed space is formed, and the detection target waves W from the detection target 200c can be detected by the sensor 11.

[0126] Furthermore, in the sensor unit 10l, the wave source 23 is fixed to the substrate 12, so that the positioning of the wave source 23 with respect to the detection object 200c can be performed simultaneously with the positioning of the substrate 12, thereby improving work efficiency. Furthermore, in the sensor unit 10l, the substrate 12 can be temporarily fixed to the surface of the detection object 200c with the fixing tape 25, so that displacement of the substrate 12 and the wave source 23 can be prevented.

[0127] In this embodiment, the fixing tape 25 is used as a fixing member for fixing the substrate 12 to the surface of the detection object 200c. However, the present invention is not limited to this. For example, double-sided tape may be provided on the substrate 12 as a fixing member, and the substrate 12 may be fixed to the detection object 200c using the double-sided tape. Alternatively, a band, cloth, or the like other than tape may be used as a fixing member to fix the substrate 12 to the detection object 200c.

[0128] Furthermore, in the above-described twelfth to fourteenth embodiments, the wave sources 22 and 23 irradiate the detection target 200 a with infrared light such as far-infrared light or ultrasonic waves, and detect the detection target waves W emitted from inside the detection target 200 c in response to the irradiation. However, the present invention is not limited to this. For example, a wave source that irradiates gamma rays, X-rays, ultraviolet light, visible light, microwaves, radio waves, vibration waves, or the like may be provided, and the detection target 200 a may be irradiated with gamma rays, X-rays, ultraviolet light, visible light, microwaves, radio waves, or vibration waves from the wave source, and the detection target waves W emitted from inside the detection target 200 c in response to the irradiation may be detected.

[0129] 15. Fifteenth Embodiment In the above-described twelfth to fourteenth embodiments, the wave sources 22 and 23 irradiate the inside of the detection target 200a with gamma rays, X-rays, ultraviolet light, visible light, infrared light such as far-infrared light, microwaves, radio waves, sound waves, or vibration waves, and detect the detection target waves W emitted from the inside of the detection target 200c in response to the irradiation. However, the present invention is not limited to this. For example, as shown in FIG. 18 , a detection device 100m may be configured such that a wave source 24 emitting gamma rays, X-rays, infrared light such as ultraviolet light, visible light, or far-infrared light, microwaves, radio waves, sound waves, or vibration waves is provided on the surface of the detection target 200d, and the detection target waves W generated in the detection target 200d are detected by the sensor unit 10a. In this case, the detection device 100m can obtain the surface state of the detection target 200d by the calculation unit 33d based on the detection result of the detection target wave W by the sensor unit 10a.

[0130] 16. Sixteenth Embodiment Next, another embodiment of a sensor unit equipped with a wave source will be described below. Fig. 19 is a schematic diagram showing the configuration of a sensor unit 10n equipped with a wave source 22 according to the sixteenth embodiment. The sensor unit 10n includes a substrate 12n having a cylindrical shape with a bottom, and the sensor 11 and the wave source 22 are provided in the internal space of an opening 121a of the substrate 12n.

[0131] Although the interior of the substrate 12n is divided by the sensor 11, the front side of the sensor 11 forms an open space ER1 that is connected to the external environment, and the back side of the sensor 11 also forms an open space ER3 that is connected to the external environment via a through hole not shown.

[0132] The substrate 12n is provided with a lattice section 27a with a wave source 22 at its center. The lattice section 27a has a plurality of (eight in this example) rod-shaped members 27a1 fixed to the inner wall of the substrate 12n, extending radially from the center of the substrate 12n, and the wave source 22 is provided at the center where these rod-shaped members 27a1 intersect. Through holes are formed between the adjacent rod-shaped members 27a1, and an open space ER1 is formed by connecting the surface side of the sensor 11 to the external environment.

[0133] The substrate 12n has a wave source 22 disposed in its internal space lower than the end position, and the sensor 11 disposed in the internal space below the wave source 22. In this case, the wave receiving unit 118 of the sensor 11 is disposed below the wave source 22. Through holes (not shown) are formed in the outer periphery and / or bottom of the substrate 12n disposed on the back side of the sensor 11, and an open space ER3 communicating with the external environment is also formed on the back side of the sensor 11. The bottom of the substrate 12n may be formed of a mesh member separate from the outer periphery.

[0134] In the above configuration, the sensor unit 10n also has the wave source 22 and the sensor 11 positioned relative to the detection target 200c with an open space ER1 provided between the sensor 11 and the detection target 200c. When far-infrared light is irradiated onto the detection target 200c from the wave source 22, the sensor unit 10n detects photoacoustic waves emitted from a predetermined component 202 (e.g., glucose) in the detection target 200c as detection target waves W via the open space ER1 using the sensor 11. Therefore, the sensor unit 10n can have a simple configuration because no enclosed space is formed, and can detect the detection target waves W from the detection target 200c using the sensor 11.

[0135] Furthermore, in a detection device provided with a sensor unit 10n, as in the twelfth embodiment described above, the electrical resistance of the sensor 11 changes depending on the strength of the wave W to be detected. By detecting this change in electrical resistance with the detection circuit 32, the concentration calculation unit 33b can determine the concentration of a specified component 202 based on the change in electrical resistance.

[0136] Next, a sensor unit according to another embodiment in which a wave source is provided on a substrate will be described below. Fig. 20 is a schematic diagram showing the configuration of a sensor unit 10p according to another embodiment, which includes a wave source 22a. The sensor unit 10p includes a cylindrical substrate 12p with a bottom, and the sensor 11 and the wave source 22a are provided in the internal space of an opening 121a of the substrate 12p.

[0137] The internal space of the substrate 12p is provided with a support portion 27b surrounding the sensor 11 located near the center of the diameter, an annular portion 27c connected to the outer periphery of the support portion 27b, and a support portion 27d connected to the outer periphery of the annular portion 27c, with the outer periphery of the outermost support portion 27d being connected to the inner wall of the substrate 12p. The substrate 12p has a configuration in which a wave source 22a is arranged in the annular portion 27c, and the sensor 11 and the wave source 22a are arranged on the same plane. The wave source 22a may be provided over the entire area of ​​the annular portion 27c, or may be provided over a partial area.

[0138] One or more through holes (not shown) are formed in the outer periphery and / or bottom of the substrate 12p disposed on the back side of the sensor 11, and an open space ER3 communicating with the external environment is also formed on the back side of the sensor 11. The bottom of the substrate 12p may be made of a mesh member separate from the outer periphery.

[0139] Even in the above configuration, the sensor unit 10p places the wave source 22a and the sensor 11 relative to the detection target 200c with an open space ER1 provided between the sensor 11 and the detection target 200c. When far-infrared light is irradiated onto the detection target 200c from the wave source 22a, the sensor unit 10p detects photoacoustic waves emitted from a predetermined component 202 (e.g., glucose) in the detection target 200c as detection target waves W via the open space ER1 using the sensor 11. Therefore, the sensor unit 10p can have a simple configuration because no enclosed space is formed, and the detection target waves W from the detection target 200c can be detected by the sensor 11.

[0140] Furthermore, in a detection device provided with a sensor unit 10p, as in the twelfth embodiment described above, the electrical resistance of the sensor 11 changes depending on the strength of the wave W to be detected. By detecting this change in electrical resistance with the detection circuit 32, the concentration calculation unit 33b can determine the concentration of a specified component 202 based on the change in electrical resistance.

[0141] 17. Others In the above-described embodiments, the sensor units 10a, 10b, 10c, 10d, 10e1, 10e2, 10f, 10g, 10h, 10i, 10j, 10l, 10n, and 10p are each disposed in the atmosphere to detect detection target waves W from detection targets 200a, 200b, and 200c, respectively. However, the present invention is not limited to this. For example, sensor units 10a, 10b, 10c, 10d, 10e1, 10e2, 10f, 10g, 10h, 10i, 10j, 10l, 10n, and 10p may be placed in a fluid such as other gases or water in addition to the atmosphere, and a structure or living organism similarly placed in the fluid may be used as a detection target. Sound waves or vibration waves generated from the detection target and propagating through the fluid may be detected as detection target waves W by sensor units 10a, 10b, 10c, 10d, 10e1, 10e2, 10f, 10g, 10h, 10i, 10j, 10l, 10n, and 10p placed in the fluid.

[0142] Furthermore, for example, sensor units 10b, 10c, 10d, 10e1, 10e2, 10f, 10g, 10h, 10i, and 10j may be applied to detection devices 100k and 100l shown in FIGS. 15 and 16, and other sensor units may be appropriately combined with the configurations of the sensor units of the above-described embodiments, or detection devices may be used therefor.

[0143] As a combination of the respective embodiments, for example, the spacers 9a, 9b, 9c, and 9d shown in Figures 4, 5A, 5B, and 5C and the vibration-isolating unit 15 shown in Figure 6 may be applied to all of the above-mentioned embodiments. Also, the dust cover 16 shown in Figure 7 and the protective cover 18 shown in Figure 9 may be applied to all of the above-mentioned embodiments. Furthermore, as a combination of the respective embodiments, it goes without saying that a sensor unit may be formed by appropriately combining the side sensor 11b, the sensor 11c provided adjacent to the sensor 11, the physical quantity sensor 19, the sensor array 11j, etc.

[0144] In the sensor units of the present application according to the first to sixteenth embodiments and other embodiments, both the front and back surfaces of the wave receiving unit 118 are exposed (open) to the external environment (visible from the outside) so as to prevent a pressure difference between the front and back surfaces of the wave receiving unit 118 and the external environment. In another embodiment of the fifth embodiment shown in FIG. 8B , the back surface of the wave receiving unit 118 ( FIG. 3 ) of the sensor 11 is surrounded by a spherical crown-shaped reflector 17d, so that the back surface of the wave receiving unit 118 is not directly visible. However, in the sensor unit 10e2, a reflector 17d having a spherical crown-shaped hollow space with a large diameter opening 121 is used, and the back surface of the wave receiving unit 118 is separated from the reflector 17d so as to prevent a pressure difference between the front and back surfaces of the wave receiving unit 118 and the external environment. As a result, in the sensor unit 10e2 as well, both the front and back surfaces of the wave receiving unit 118 are exposed (open) to the external environment, so that a pressure difference between the front and back surfaces of the wave receiving unit 118 and the external environment does not occur.

[0145] 9 and the sensor unit 10g according to the seventh embodiment shown in Fig. 10 each have a protective cover 18, but as described above, the bottom 18b of the protective cover 18 also has a through-hole (not shown in Fig. 9) that communicates with the external environment, and the back surface of the wave receiving unit 118 (Fig. 3) of the sensor 11 is open to the external environment to such an extent that it can be seen from the outside through the through-hole. Therefore, the sensor unit 10f according to the sixth embodiment is also configured so that no pressure difference occurs between the front and back surfaces of the wave receiving unit 118 and the external environment.

[0146] 19 shows a sensor unit 10n according to a sixteenth embodiment, in which a sensor 11 is provided in a cylindrical substrate 12n with a bottom, but as described above, a lattice portion 27a is provided on the substrate 12n so that the surface of the wave receiving portion 118 (FIG. 3) of the sensor 11 is exposed (open) to the external environment. The bottom of the substrate 12n also has a through-hole (not shown in FIG. 19) that communicates with the external environment, and the back surface of the wave receiving portion 118 (FIG. 3) of the sensor 11 is open to the external environment to the extent that it can be seen from the outside through the through-hole. Therefore, the sensor unit 10n according to the sixteenth embodiment is also configured so that no pressure difference occurs between the front and back surfaces of the wave receiving portion 118 and the external environment.

[0147] 20, the sensor 11 is also provided in a cylindrical substrate 12p with a bottom, but as described above, the substrate 12p also has a through-hole (not shown in FIG. 20) at the bottom thereof that communicates with the external environment, and the back surface of the wave-receiving unit 118 (FIG. 3) of the sensor 11 is open to the external environment to such an extent that it can be seen from the outside through the through-hole. Therefore, even in this type of sensor unit 10p, no pressure difference occurs between the front and back surfaces of the wave-receiving unit 118 and the external environment.

[0148] As described above, the sensor unit according to the present application is an open type in which both the front and back surfaces of the wave receiving section 118 are open to the outside. By configuring the wave receiving section 118 in this way so that both the front and back surfaces are open, the following effects can be achieved, for example, when the sensor unit is made wearable.

[0149] For example, if both the front and back surfaces of the wave receiving unit 118 are used as airtight chambers, the detection target is placed inside one of the airtight chamber structures. In this case, there is no influence (reduction in measurement accuracy) from pressure changes in the external environment. However, when the sensor unit is made wearable and, for example, to measure sound waves (detection target waves) emitted when glucose in a person's blood vessels absorbs light, a configuration in which the sensor unit is pressed against the person's skin to maintain airtightness on the front side of the wave receiving unit 118 is conceivable. However, with such a configuration, depending on the location of the skin, a gap may form between the sensor unit and the skin, making it difficult to maintain airtightness. In this case, the front side of the wave receiving unit 118 becomes open. In such a situation, if a change in sound occurs in the external environment (e.g., the sound of a door opening or closing), a pressure difference occurs between the front and back surfaces of the wave receiving unit 118, making it difficult to accurately measure the vibrations and sound waves emitted from the detection target.

[0150] In contrast, in the sensor unit of the present application, both the front and back surfaces of the wave receiving section 118 are open and configured to detect target waves, so even if there is a change in sound in the external environment, the pressure does not change on the front and back surfaces of the wave receiving section 118. This makes it possible to accurately measure target waves, such as vibrations and sound waves, emitted from the target without being affected by changes in the external environment. Furthermore, the sensor unit does not require a mechanism to passively cancel out the effects of pressure changes in the external environment, which allows for a corresponding reduction in size.

[0151] 18. Verification Test (Verification Test Using a Speaker) Next, as shown in Fig. 1, a sensor unit was fabricated in which an open space ER1 communicating with the external environment was provided between the sensor and the detection target, and an open space ER2 communicating with the external environment was also provided on the back side of the sensor located opposite the detection target, and a verification test was conducted to determine whether or not the sensor unit could detect sound waves. As shown in Fig. 21, a sensor unit 10s having a sensor 11a provided in an opening 121 of a substrate 12 was installed in an opening in a support plate 300 15 cm away from a speaker S1, which serves as a sound source (d = 15 cm in Fig. 21).

[0152] The sensor provided in the sensor unit 10s used in the verification test was the sensor 11a shown in FIG. 2B, and was fabricated according to "(1-3) Sensor Fabrication Method" described in the first embodiment above. The wave-receiving section 118 was configured to be connected to the frame 119 by two adjacent beam sections 42, 43 via a notch 52, and the length and width of the wave-receiving section 118 were approximately 100 μm, and the thickness was approximately 0.08 μm. The notch 51a separating the wave-receiving section 118 from the frame 119 was 1 μm.

[0153] Then, the output voltage, which changes in response to the change in electrical resistance in the sensor 11a, was measured when no sound was emitted from the speaker S1 and when the sound was emitted, and the results shown in Figure 22A were obtained.

[0154] 22A shows the output voltage when no sound is emitted from the speaker S1, and waveform D2 shows the output voltage when sound is emitted from the speaker S1. The output voltage of the sensor unit 10s increases when sound is emitted from the speaker S1, and it was confirmed that the sensor 11a can detect the sound waves emitted from the speaker S1 even if there is no air chamber or airtight chamber on the front or back side of the sensor 11a.

[0155] FIG. 22B is a graph showing the relationship between frequency and sensitivity. The sensitivity was calculated as follows. First, the output voltage of the sensor 11a was measured for each frequency, and the resistance change rate of the sensor 11a was calculated from the voltage value. Then, the sensor unit 10s was removed, and a microphone was placed in the same position as the sensor unit 10s, and the sound pressure of the sound emitted from the speaker S1 for each frequency was measured with the microphone. This is the value obtained by dividing the resistance change rate of the sensor 11a by the sound pressure of the sound from the speaker S1. From FIG. 22B, it was confirmed that the sensitivity was high and that the sensor unit 10s could detect sound waves.

[0156] Next, the output voltage of the sensor was measured when the distance d between the support plate 300 on which the sensor unit 10s was installed and the speaker S1 was set to 7 mm, 15 mm, and 25 mm, and the results shown in Figure 23A were obtained.

[0157] 23A, waveform D4 is the output voltage of sensor 11a obtained when distance d was 7 mm, waveform D5 is the output voltage of sensor 11a obtained when distance d was 15 mm, and waveform D6 is the output voltage of sensor 11a obtained when distance d was 25 mm. From the results in FIG. 23A, it was confirmed that the output voltage was high and that sensor 11a could detect sound waves emitted from speaker S1 even if no air chamber or airtight chamber was present on the front or back side of sensor 11a.

[0158] Furthermore, waveform D7 shown in Figure 23B was obtained by examining how the output voltage of sensor 11a changes when a partition plate is inserted between speaker S1 and sensor unit 10s. From the results of Figure 23B, it was confirmed that when a partition plate is inserted between speaker S1 and sensor unit 10s and the sound waves from speaker S1 are blocked by the partition plate, waveform D7 drops sharply. Therefore, it was confirmed that sensor 11a can detect sound waves emitted from speaker S1 even if there is no air chamber or airtight chamber on the front or back side of sensor 11a.

[0159] (Verification Test Using Vibrator) Next, a verification test was conducted to determine whether the sensor unit 10s could detect vibration waves using a vibrator S2 that emits vibration waves instead of the speaker S1. Here, the sensor output of the sensor 11a obtained when the distance d between the support plate 300 on which the sensor unit 10s was installed and the vibrator S2 was set to 7 mm was measured. As a result, the results shown in FIG. 23C were obtained.

[0160] The sensor output is normalized based on the maximum output voltage obtained from the sensor 11a. From the waveform D8 in Fig. 23C, it was confirmed that the sensor output is high and that even if there is no air chamber or airtight chamber on the front or back side of the sensor 11a, it is possible to detect vibration waves from low frequencies to the ultrasonic range that cannot be detected by commercially available microphones, which are emitted from the vibrator S2.

[0161] 10a, 10b, 10c, 10d, 10e, 10f, 10g, 10h, 10i, 10j, 10l, 10n, 10p, 10s Sensor unit 11, 11a, 11s Sensor 12, 12e, 12n, 12p, 17 Substrate 121, 121a Opening 30, 30b Circuit section 100a, 100b, 100c, 100d, 100e1, 100e2, 100f, 100g, 100h, 100i, 100j, 100l, 100m Detection device

Claims

1. A sensor unit that detects vibration waves or sound waves emitted from an object to be detected as detection target waves, comprising: a sensor that is mounted on a substrate and whose electrical resistance changes according to the displacement caused by receiving the detection target waves; and an open space that communicates with the external environment is provided between the sensor and the object to be detected, and on the back side of the sensor that is located on the opposite side of the sensor from the object to be detected.

2. A sensor unit as described in claim 1, which is placed relative to the detection object with an open space provided between the sensor and the detection object, and the detection object wave is detected by the sensor through the open space between the sensor and the detection object.

3. The sensor unit according to claim 1, wherein the sensor comprises a plate-shaped wave receiving portion a portion of which is fixed to the substrate.

4. The sensor unit according to claim 1, wherein the substrate is provided with a spacer that comes into contact with the detection target.

5. The sensor unit according to claim 1, wherein the sensor unit is disposed in contact with the object to be detected, and a vibration isolating section that absorbs vibrations from the object to be detected is provided between the substrate and the object to be detected.

6. The sensor unit according to claim 1, wherein the substrate has one or more through holes formed therein and is provided with a dust cover for capturing dust from the outside.

7. The sensor unit according to claim 1, wherein the substrate has a wall portion formed so as to surround the sensor, and the detection target wave is focused toward the sensor.

8. The sensor unit according to claim 1, wherein a protective cover is provided on the back side of the sensor, which is located opposite the object to be detected, so as to surround the back side of the sensor while forming the open space communicating with the external environment.

9. A sensor unit as described in claim 1, further comprising a side sensor provided between the detection target and the sensor for detecting noise and / or the detection target wave from a lateral direction, the detection results of the sensor and the side sensor being output to a circuit section, and the detection target wave with the noise suppressed being measured by the circuit section based on the detection results of the sensor and the detection results of the side sensor.

10. The sensor unit according to claim 1, comprising a configuration in which a plurality of substrates are connected together, each substrate being provided with the sensor, and the sensors are positioned at a predetermined distance from one another by the substrates.

11. A sensor unit as described in claim 1, comprising a physical quantity sensor that measures at least one of the physical quantities of temperature, pressure, luminosity and magnetism, and outputs the detection result of said sensor and the measurement result of said physical quantity sensor to a circuit section, which generates a measurement result that associates the detection target wave with the physical quantity based on the detection result of said sensor and the measurement result of said physical quantity sensor.

12. The sensor unit according to claim 1, wherein a plurality of sensors are arranged in a matrix on the substrate.

13. The sensor unit according to claim 1, wherein the sensor detects the detection target wave emitted from the detection target when gamma rays, X-rays, ultraviolet light, visible light, infrared light, microwaves, radio waves, the sound waves or the vibration waves are irradiated from a wave source to the detection target.

14. The sensor unit according to claim 13, wherein the wave source is disposed in a non-contact manner with the detection target.

15. The sensor unit according to claim 13, wherein the wave source is arranged in contact with the detection target.

16. The sensor unit according to claim 15, wherein the wave source is provided on the substrate and serves as a spacer for positioning the substrate relative to the detection target.

17. The sensor unit according to claim 13, wherein the wave source emits intensity-modulated infrared light, and the sensor detects, as the detection target wave, a photoacoustic wave emitted from the detection target irradiated with the infrared light.

18. The sensor unit according to claim 13, wherein the wave source emits ultrasonic waves, and the sensor receives the detection target wave emitted from the detection target by irradiating the detection target with the ultrasonic waves.

19. The sensor unit according to claim 1, further comprising a fixing member for fixing the substrate to the surface of the detection target.

20. The sensor unit according to claim 1, which is disposed in a fluid and measures the detection target wave generated from the detection target and propagating through the fluid.

21. A detection device that detects vibration waves or sound waves emitted from a detection target as detection target waves, comprising: a sensor unit that receives the detection target waves; and a circuit section that measures the detection target waves based on the detection results obtained by the sensor unit, wherein the sensor unit has a sensor that is provided on a substrate and whose electrical resistance changes according to the displacement caused by receiving the detection target waves, and an open space that communicates with the external environment is provided between the sensor and the detection target, and on the back side of the sensor that is located on the opposite side of the sensor from the detection target.