JP2010133791A - Sheet-form sensor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sheet-form sensor device which can be manufactured with ease and at low cost and excels in design properties. <P>SOLUTION: The sensor device includes a sensor body 4 which is constituted by sewing coaxial cables 3 of a thin diameters in a sheet body 2 of woven fabric, knit or the like formed like a sheet and a detecting means 5 which detects the approach of a detecting object to the sensor body 4 or the contact of the object therewith by measuring a change in capacitance between an inner conductor 7 and an outer conductor 9 of the coaxial cable 3 sewn in the sensor body 4. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a sheet-like sensor device that detects the proximity or contact of an object to be detected on a non-uniform surface.

  2. Description of the Related Art A sheet sensor device having a sheet sensor unit is used for monitoring the state of a patient sleeping on a bed or detecting a driver's seating in an automobile.

  A sheet-like sensor device is a sheet-like sheet body such as a woven fabric or a knitted fabric that has a sensor function. Even on non-uniform surfaces such as a bed or an automobile seat, Contact can be detected.

  As such a sheet-like sensor device, conventionally, as shown in FIG. 13, a pressure-sensitive sensor 133 is incorporated between two upper and lower sheet substrates 132, and the resistance value of the pressure-sensitive sensor 133 due to a load applied to the sheet substrate 132 is measured. There has been proposed a sheet-like sensor device 131 that detects a contact of a detection object by measuring a change (see, for example, Patent Document 1).

  Further, as shown in FIG. 14, a fiber body 144 made of conductive fibers 142 such as stainless steel and carbon and a non-conductive material 143 such as cotton or polyester covering the periphery is used. A sensor body 145 that is knitted as a weft yarn and made into a woven fabric, and applies a voltage between the warp yarn and the weft yarn to detect a change in capacitance at the intersection, thereby detecting the contact of the detection object A sensor device 141 has been proposed (see, for example, Patent Document 2).

  In this sheet-like sensor device 141, in order to detect a change in capacitance at the intersection, it is possible to measure the floating capacitance formed between the sensor body 145 and the detection target, Proximity can be detected.

JP 2004-132765 A JP 2006-234716 A

  However, in the sheet-like sensor device 131 of FIG. 13, since the resolution when detecting the contact of the detection object depends on the number of pressure-sensitive sensors 133, it is necessary to use a large number of pressure-sensitive sensors 133 in order to increase the resolution. There is a problem that it is expensive. Further, since the pressure-sensitive sensor 133 is used in a large amount, it takes time to arrange the pressure-sensitive sensor 133 at the time of manufacture, which is unsuitable for mass production and difficult to manufacture at a low cost.

  On the other hand, the sheet-like sensor device 141 in FIG. 14 employs a method of measuring the change in capacitance at the intersection of the warp and weft, so that the thickness of the intersection so that the change in capacitance can be detected. This is necessary, and it is difficult and troublesome to design and adjust the fiber body 144 used for the warp and the weft. Therefore, there is a problem that it is not suitable for mass production and is difficult to manufacture at low cost.

  In addition, the non-conductive material 143 is spirally spun or spun around the conductive fiber 142 to form the fiber body 144, so that it is non-conductive in consideration of ease of spinning and flexibility in the woven state. Material selection of the material 143 must be performed, and the materials that can be used are limited.

  Furthermore, since the textile body 144 is used for the warp and the weft to form the woven sensor body 145, there is a problem that the thickness, material and shape of the sensor body 145 are limited.

  Therefore, an object of the present invention is to provide a sheet-like sensor device that is excellent in design and can be manufactured easily and at low cost.

  The present invention has been devised to achieve the above object, and the invention of claim 1 is configured by sewing a coaxial cable having a small diameter into a sheet body formed into a sheet shape such as a woven fabric or a knitted fabric. And detecting the proximity or contact of an object to be detected with the sensor body by measuring a change in capacitance between the inner conductor and the outer conductor of the coaxial cable sewn into the sensor body. And a sheet-like sensor device.

  According to a second aspect of the present invention, the sensor body is formed by sewing a plurality of the coaxial cables into the sheet body so as to intersect each other in the vertical direction and the horizontal direction, and the detecting means includes an inner conductor and an outer part of each coaxial cable. The sheet-like sensor device according to claim 1, wherein a region where the detection target object approaches or contacts the sensor main body is detected by sequentially measuring a change in capacitance between conductors.

  According to a third aspect of the present invention, the detection means is an LC resonance circuit that is electrically connected to the coaxial cable and outputs an AC signal having an oscillation frequency corresponding to the capacitance between the inner conductor and the outer conductor of the coaxial cable. And a wave shaping circuit that waves the alternating current signal from the LC resonance circuit and outputs a pulse signal, and a time measurement counter that counts the pulse signal from the wave shaping circuit and measures the time to be a predetermined count number And an oscillator that outputs a clock signal having a constant frequency higher than that of the pulse signal, and the clock signal output from the oscillator is counted using the time measured by the time measurement counter as a gate time, and this is counted. A pulse counter that outputs as a number, and a change in the number of counts from the pulse counter, so that the object to be detected with respect to the sensor body A sheet sensor device according to claim 1 or 2, wherein and a contact determination unit for detecting a proximity or contact.

  According to a fourth aspect of the present invention, when the object to be detected approaches or comes into contact with the sensor body, it acts in a direction in which the count number of the pulse counter increases and the coaxial cable is bent. 4. The sheet-like sensor device according to claim 3, which operates in a direction in which the count number of the pulse counter decreases.

  According to a fifth aspect of the present invention, the detection means uses a capacitance between the inner conductor and the outer conductor of the coaxial cable at the time of starting the system such as when the power is turned on or when the power is restored, as a reference value, and the reference value and the measured value. It is a sheet-like sensor apparatus in any one of Claims 1-4 which detects the proximity | contact or contact of the said detection target object when the difference with this exceeds a predetermined threshold value.

  According to a sixth aspect of the present invention, when the reference value has already exceeded the threshold at the time of system start-up such as power-on or power failure recovery, the reference means set at the time of the previous system start-up 6. The sheet-like sensor device according to claim 5, which employs a value.

  ADVANTAGE OF THE INVENTION According to this invention, the sheet-like sensor apparatus which is excellent in design property, and can be manufactured easily and at low cost can be provided.

  Preferred embodiments of the present invention will be described below with reference to the accompanying drawings.

  FIG. 1 is a schematic view of a sheet-like sensor device according to the first embodiment.

  As shown in FIG. 1, a sheet-like sensor device 1 includes a sensor main body 4 configured by sewing a small-diameter coaxial cable (sensor cable) 3 into a sheet body 2 formed in a sheet shape such as a woven fabric or a knitted fabric. As a detecting means for detecting the proximity or contact of the detection object to the sensor body 4 by measuring the change in capacitance between the inner conductor and the outer conductor of the coaxial cable 3 sewn into the sensor body 4 And a capacitance measuring unit 5.

  The sheet body 2 may be any material that can be sewn, and the thickness and material are not limited. Further, FIG. 1 shows an example in which six coaxial cables 3 are sewn into the sheet body 2 substantially in parallel, but the number and arrangement of the coaxial cables 3 are not limited thereto.

  Each coaxial cable 3 is connected to the capacitance measuring unit 5 via a timing switching unit 6 that is switching-controlled by a control unit such as a microcomputer (not shown). The timing switching unit 6 is controlled to perform switching at predetermined time intervals (select a predetermined coaxial cable 3 at a predetermined timing) and sequentially connect the coaxial cable 3 to the capacitance measuring unit 5.

  As shown in FIG. 2, the coaxial cable 3 used in the present invention is a small-diameter coaxial cable in which an insulator 8, an outer conductor 9, and a protector 10 are sequentially formed on the outer periphery of an inner conductor 7 in a coaxial shape. The diameter of the coaxial cable 3 is, for example, about 200 to 350 μm.

  The inner conductor 7 is made of, for example, silver-plated copper alloy wire or tin-plated annealed copper wire, and the insulator 8 is made of, for example, fluorine resin. The outer conductor 9 may have either a braided structure or a laterally wound structure, for example, a braided structure of a silver-plated copper alloy wire. The protector 10 is made of, for example, a fluorine resin or a polyester tape. The coaxial cable 3 is, for example, AWG (American Wire Gauge) # 46, # 44, # 40, # 36, or the like.

  As shown in FIG. 3A, the sensor main body 4 may be configured by corrugating the coaxial cable 3 on the sheet body 2 and alternately arranging the coaxial cable 3 on the front surface and the back surface of the sheet body 2. As shown in FIG. 3 (b), a sewing machine for home use, industrial use or business use is used, and two coaxial cables 3 are sewn into the sheet body 2 using upper and lower threads. Also good. By forming the sensor body 4 using a sewing machine, the time for sewing the coaxial cable 3 into the sheet body 2 can be shortened, so that productivity can be improved.

  Although FIG. 3B shows the case where the coaxial cable 3 is used for both the upper thread and the lower thread, the coaxial cable 3 may be used only for either the upper thread or the lower thread. When the coaxial cable 3 is used only for the lower thread, the coaxial cable 3 can be prevented from appearing on the surface of the sheet body 2, so that the design can be improved.

  As shown in FIG. 4A, the capacitance measuring unit 5 is electrically connected to the coaxial cable 3 and has an oscillation frequency corresponding to the capacitance between the inner conductor 7 and the outer conductor 9 of the coaxial cable 3. The LC resonance circuit 41 that outputs the AC signal a, the wave-matching circuit 42 that waves the AC signal a from the LC resonance circuit 41 and outputs the pulse signal p, and the pulse signal p from the wave-matching circuit 42 are counted. A frequency counter 43 that outputs the count number c of the pulse signal p input at a predetermined time, and the proximity or contact of the detection object to the sensor body 4 is detected from the change in the count number c from the frequency counter 43 (not shown) A contact determination unit.

FIG. 4B shows a circuit diagram of the LC resonance circuit 41 used in the present invention. As shown in FIG. 4B, the LC resonance circuit 41 is, for example, a Colvitts oscillation circuit. In FIG. 4B, C _v indicates the capacitance between the inner conductor 7 and the outer conductor 9 in the coaxial cable 3. The LC resonance circuit 41 is not limited to this.

In the sheet-like sensor device 1, when a detection object such as a human body approaches or contacts the sensor body 4, a floating capacitance is formed between the coaxial cable 3 and the detection object, and _Cv increases. As a result, the frequency (oscillation frequency) of the AC signal a output from the LC resonance circuit 41 is decreased, and the count number c output from the frequency counter 43 is decreased. The contact determination unit detects the proximity or contact of the detection target object from the decrease in the value of the count number c.

  The oscillation frequency (resonance frequency) of the LC resonance circuit 41 may be set to a frequency range in which the floating capacitance formed between the human body that is the detection target and the coaxial cable 3 can be detected with high sensitivity. Specifically, the oscillation frequency of the LC resonance circuit 41 is preferably set to about several hundred kHz to several MHz.

In the sheet-like sensor device 1, a plurality of (six in FIG. 1) coaxial cables 3 are provided substantially in parallel. Therefore, by measuring the change in C _v (change in the count number c) in each coaxial cable 3, Since the proximity or contact of the detection object can be determined for each coaxial cable 3, the area where the detection object is close or in contact can be detected one-dimensionally.

  Further, the sheet-like sensor device 1 can detect not only the proximity or contact of a detection object such as a human body but also the adhesion of water to the sensor body 4 and the bending of the sensor body 4.

  Here, the determination method in the contact determination unit will be described in detail.

First, the contact determination unit measures the capacitance C _v (count number c) between the inner conductor 7 and the outer conductor 9 of the coaxial cable 3 at the time of system startup at the time of system startup such as when the power is turned on or power failure is restored. The measured count value c is stored as a reference value. In other words, the contact determination unit stores the value of the count number c measured first after the system startup as the reference value.

(1) When the detection object are close to or in contact as described above, when the detection object is close to or in contact with the sensor body 4 (the coaxial cable 3), the electrostatic capacitance C _v of measuring increases, as a result, the count The value of the number c becomes small. When the value of the count number c decreases below the reference value and the difference between the measured count number c and the reference value exceeds a predetermined threshold, the contact determination unit approaches or touches the detection target object. Is detected.

  In the first embodiment, only one threshold is provided, but the proximity state and the contact state can be distinguished by setting the threshold to two steps.

(2) When the sensor body 4 is bent The present inventors have found that when the sensor body 4 (coaxial cable 3) is bent, the measured capacitance _Cv behaves as if it has decreased. . The cause of this is not clear, but it is thought that leakage of electromagnetic waves has an effect.

That is, when the sensor body 4 is bent, the measured capacitance _Cv apparently decreases, and as a result, the count number c increases. In the contact determination unit, the sensor body 4 is bent when the value of the count number c increases from the reference value and the difference between the measured count value c and the reference value exceeds a predetermined threshold value. Detect that.

(3) When water adheres to the sensor body 4 When liquid such as water (water droplets, sweat, etc.) adheres to the sensor body 4 (coaxial cable 3), as in the case of (1), the adhered water and the coaxial cable Since the floating electrostatic capacity is formed between the number 3 and the measured electrostatic capacity Cv, the measured electrostatic capacity _Cv increases, and as a result, the count number c decreases. Since the adhesion of water is continuous, the contact determination unit determines that the water has adhered when the value of the count number c is continuously small for a certain period.

  That is, the contact determination unit determines that the count number c is smaller than the reference value, the difference between the measured count number c and the reference value exceeds a predetermined threshold, and the count number c is When it is small for a certain period of time, it is detected that water has adhered to the sensor body 4.

  When water adheres to the sensor main body 4, the proximity or contact of the detection target cannot be detected at the portion where the water adheres. Therefore, when it is detected that water has adhered, the contact determination unit may newly adopt the count number c after the water adhesion as a reference value. Thereby, it becomes possible to detect the proximity | contact or contact of a detection target object except the influence of adhesion of water.

  In addition, when the detection target is already close to or in contact with the sensor body 4 at the time of system startup, the value of the count c (reference value) measured first after the system startup has already exceeded a predetermined threshold The standard value set at the previous system startup is adopted.

  The operation of the first embodiment will be described.

In the sheet-like sensor device 1 according to the first embodiment, a thin coaxial cable 3 is sewn into a sheet body 2 to form a sensor main body 4, and the inner conductor of the coaxial cable 3 sewn into the sensor main body 4. by measuring the change in capacitance C _v between 7 and an outer conductor 9, and detects the proximity or contact of a detection object with respect to the sensor body 4.

  By sewing the coaxial cable 3 into the sheet body 2, the coaxial cable 3 can be easily fixed to the sheet body 2, and as a result, the sheet-like sensor device 1 can be easily manufactured.

  In addition, it is possible to use cloths of various materials as the sheet body 2 or to use the sheet body 2 in various shapes by covering the sheet or bed of an automobile, and when the coaxial cable 3 is sewn. Since it becomes possible to give a predetermined design by the variation of the seam, the sheet-like sensor device 1 excellent in design can be realized. In the sheet-like sensor device 1, the sensor main body 4 can be configured only by sewing the coaxial cable 3 regardless of the material of the sheet body 2, so that it can be manufactured at a low cost and can be retrofitted.

  Further, in the sheet-like sensor device 1, when the count number c of the frequency counter 43 decreases, it is detected that the detection target object approaches or contacts the sensor body 4, and the count number c increases. Detects that the sensor body 4 is bent.

  Thereby, it becomes possible to distinguish and detect the proximity | contact or contact of a detection target object, and the bending added to the sensor main body 4, and the sheet-like sensor apparatus 1 with a sufficient detection accuracy is realizable. In particular, when the sheet-like sensor device 1 is used as a wearable sensor, it is very useful to be able to distinguish between a bent state and a contacted state.

Furthermore, in the sheet-like sensor device 1, the electrostatic capacitance C _v (count number c) between the inner conductor 7 and the outer conductor 9 of the coaxial cable 3 at the time of starting the system is used as a reference value, and the difference between the reference value and the measured value is When a predetermined threshold value is exceeded, the proximity or contact of the detection target is detected.

  By setting the reference value when the system is activated, it is possible to avoid the influence of the humidity of the sheet body 2 itself that changes daily. Moreover, by providing a threshold value, detection noise can be removed, and a detection target can be reliably detected.

  Moreover, in the sheet-like sensor device 1, when the reference value has already exceeded the threshold value at the time of system startup, the reference value set at the time of the previous system startup is adopted.

  Thereby, it is possible to cope with, for example, even when a detection target has already been detected when the system is started.

  Next, a second embodiment will be described.

  As shown in FIG. 5, the sheet-like sensor device 50 has a plurality of coaxial cables 3 crossed in the longitudinal direction (X-axis direction) and the lateral direction (Y-axis direction) and sewn into the sheet body 2 to sew the sensor main body 51. It is composed.

  FIG. 5 shows an example in which six coaxial cables 3 are arranged in a lattice shape in the vertical direction (X-axis direction) and six in the horizontal direction (Y-axis direction), but the number and arrangement of the coaxial cables 3 are limited. Not.

According to the sheet-like sensor device 50, by sequentially measuring the change in capacitance C _v between the inner conductor 7 and the external conductor 9 of the coaxial cable 3, the detection target is close to or contact with the sensor body 4 The region (distribution) to be performed can be specified two-dimensionally.

  Further, similarly to the sheet-like sensor device 1 of FIG. 1, it is possible to two-dimensionally specify a region where water is attached to the sensor body 4 or a region where the sensor body 4 is bent.

  Next, a third embodiment will be described.

  A sheet-like sensor device 60 shown in FIG. 6 has basically the same configuration as the sheet-like sensor device 1 shown in FIG.

  The capacitance measuring unit 61 is similar to the LC resonance circuit 41 described with reference to FIG. 4B, and the wave-matching circuit 42 that waves the AC signal a from the LC resonance circuit 41 and outputs a pulse signal p. And a time measurement counter 62 that counts the pulse signal p from the wave rectifier circuit 42 and measures the time to reach a predetermined count number, and an oscillator that outputs an AC clock signal cla having a constant frequency higher than that of the pulse signal p. A clock signal using (OSC) 63, a harmonic wave circuit 64 that waves the AC clock signal cla from the oscillator 63 and outputs a pulsed clock signal clp, and the time measured by the time measurement counter 62 as a gate time. A pulse counter 65 that counts clp and outputs this as a count number c, and measures a change in the count number c of the pulse counter 65 Ri, and a contact determination unit (not shown) for detecting the proximity or contact of a detection object with respect to the sensor body 4.

  In the third embodiment, an oscillator 63 that outputs an AC clock signal cla and a wave-matching circuit 64 that waves the AC clock signal cla and outputs a pulsed clock signal clp are used. An oscillator that outputs the clock signal “clp” may be used, and the harmonizing circuit 64 may be omitted.

  A time chart of each signal in the capacitance measuring unit 61 is shown in FIG. In FIG. 7, (A) is a pulse signal p output from the harmonic circuit 42, (B) is a clock signal clp output from the harmonic circuit 64, (C) is a count number in the time measurement counter 62, ( D) indicates the count number in the pulse counter 65.

  FIG. 7 shows a time chart when the frequency (oscillation frequency) of the AC signal a output from the LC resonance circuit 41 is 480 kHz and the oscillation frequency of the oscillator 63 is 25 MHz as an example.

  As shown in FIG. 7, the time measurement counter 62 starts counting the pulse signal p and simultaneously transmits a count start signal to the pulse counter 65, and the pulse counter 65 starts counting the clock signal clp.

  Thereafter, when the count number of the pulse signal p reaches a predetermined count number (for example, 20000), the time measurement counter 62 transmits a count end signal to the pulse counter 65, and the pulse counter 65 receives the clock signal clp. End the count. The pulse counter 65 outputs the count number at the end of the count (1041666 in FIG. 7) as the count number c to the contact determination unit.

In the capacitance measuring unit 61, contrary to the capacitance measuring unit 5 described in FIG. 4A, when the capacitance C _v measured by the proximity or contact of the detection target increases, the AC signal a Since the frequency is lowered and the gate time (time when the count number of the pulse signal p is a predetermined count number) measured by the time measurement counter 62 is increased, the count number c output from the pulse counter 65 is increased.

  More specifically, as shown in FIG. 8, when the hand is brought into contact with the coaxial cable 3, the count number c output from the pulse counter 65 increases, for example, by about 15000 counts.

Similarly, when the capacitance C _v of measuring the sensor body 4 is bent is reduced apparently, the frequency of the AC signal a is high, the gate time is shortened, which is measured by the time measuring counter 62, the pulse counter 65 The output count number c becomes smaller.

  More specifically, as shown in FIG. 9, when the coaxial cable 3 is bent, the count number c output from the pulse counter 65 decreases, for example, by about 15000 counts.

  Here, a determination method in the contact determination unit of the sheet-like sensor device 60 will be described.

(1) When a detection target object approaches or contacts, as shown in FIG. 10, when the detection target object approaches or contacts the sensor main body 4, the count number c increases (in FIG. 10, about 10,000 counts). Therefore, the contact determination unit approaches the detection object when the value of the count number c increases from the reference value and the difference between the measured count number c and the reference value exceeds a predetermined threshold value. Alternatively, contact is detected.

(2) When the sensor main body 4 is bent As shown in FIG. 11, when the sensor main body 4 is bent, the count number c decreases (in FIG. 11, about 7000 counts). Therefore, when the value of the count number c decreases from the reference value, and the difference between the measured count number c and the reference value exceeds a predetermined threshold, the contact determination unit causes the sensor body 4 to bend. It is detected that

(3) When water adheres to the sensor body 4 As shown in FIG. 12, when water (water drops, sweat, etc.) adheres to the sensor body 4, the count number c continuously increases for a certain period (in FIG. About 5000 counts). Therefore, the contact determination unit increases the value of the count number c from the reference value, and the difference between the measured count value c and the reference value exceeds a predetermined threshold value. When it is large for a certain period of time, it is detected that water has adhered to the sensor body 4.

According to the sheet-shaped sensor device 60 according to the third embodiment, the oscillator 63 having an oscillation frequency larger than the oscillation frequency of the LC resonance circuit 41 is used, and the capacitance C _v (the LC oscillation circuit 41 Since the gate time corresponding to the (transmission frequency) is measured and the clock signal clp from the oscillator 63 within the gate time is counted, the resolution is improved and the detection accuracy can be improved.

  In the present invention, since the oscillation frequency of the LC resonance circuit 41 is set to about several hundred kHz to several MHz, the resolution is lowered when the capacitance measuring unit 5 shown in FIG. 4A is used. Therefore, the measurement time becomes long to obtain a change in the number of counts necessary for the determination of proximity or contact, but by using the capacitance measuring unit 61 of FIG. 6, the resolution is improved and the measurement time is shortened. Therefore, it is possible to detect a change in the count number c (proximity or contact of the detection target) with accuracy in the order of msec.

  In the third embodiment, the sensor body having the same configuration as that of the sensor body 4 in the sheet-like sensor device 1 in FIG. 1 is used, but the sensor body may have the same configuration as that of the sensor body 51 in the sheet-like sensor device 50 in FIG. Good.

  In the above embodiment, the case where the sensor body 4 is formed by sewing the coaxial cable 3 on the entire sheet body 2 has been described. However, the coaxial cable 3 is sewn only on a part of the sheet body 2 and detected by the sensor body 4. You may make it form the sensor part which detects the proximity | contact or contact of a target object.

  The sheet-like sensor device of the present invention can be used for, for example, a care support system having an ecological information monitoring function, a car seat sensor, a wearable sensor, and the like, such as a device for monitoring the state of a patient sleeping on a bed. it can.

It is the schematic of the sheet-like sensor apparatus which concerns on the 1st Embodiment of this invention. It is the schematic of the coaxial cable used for the sheet-like sensor apparatus of FIG. 3A and 3B are cross-sectional views of a sensor body used in the sheet-like sensor device of FIG. 4A is a schematic diagram of a capacitance measuring unit used in the sheet-like sensor device of FIG. 1, and FIG. 4B is a circuit diagram of the LC resonance circuit. It is the schematic of the sheet-like sensor apparatus which concerns on the 2nd Embodiment of this invention. It is the schematic of the electrostatic capacitance measurement part used for the sheet-like sensor apparatus which concerns on the 3rd Embodiment of this invention. It is a figure which shows the time chart of each signal in the electrostatic capacitance measurement part of FIG. In the sheet-like sensor device of FIG. 6, it is a figure which shows the change of the count number at the time of making a hand contact the coaxial cable. In the sheet-like sensor device of FIG. 6, it is a figure which shows the change of the count number at the time of bending a coaxial cable. In the sheet-like sensor device of FIG. 6, it is a figure which shows the change of the count number at the time of making a hand contact a sensor main body. In the sheet-like sensor device of FIG. 6, it is a figure which shows the change of count number at the time of bending a sensor main body. In the sheet-like sensor device of FIG. 6, it is a figure which shows the change of the count number at the time of making a water drop adhere to a sensor main body. It is the schematic of the conventional sheet-like sensor apparatus. It is the schematic of the conventional sheet-like sensor apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Sheet-like sensor apparatus 2 Sheet body 3 Coaxial cable 4 Sensor main body 5 Capacitance measurement part (detection means)
7 Inner conductor 9 Outer conductor

Claims (6)

  A sensor body formed by sewing a coaxial cable having a small diameter into a sheet body formed into a sheet shape such as a woven fabric or a knitted fabric, and between the inner conductor and the outer conductor of the coaxial cable sewn into the sensor body. A sheet-like sensor device comprising: a detecting unit that detects a proximity or a contact of an object to be detected with the sensor body by measuring a change in capacitance.   The sensor body is configured by sewing a plurality of the coaxial cables into the sheet body so as to cross in the vertical direction and the horizontal direction, and the detection means has a capacitance between the inner conductor and the outer conductor of each coaxial cable. The sheet-like sensor device according to claim 1, wherein a region where the detection target approaches or contacts the sensor main body is detected by sequentially measuring changes.   The detection means is electrically connected to the coaxial cable, and outputs an AC signal having an oscillation frequency corresponding to the capacitance between the inner conductor and the outer conductor of the coaxial cable, and the LC resonance circuit A harmonizing circuit that harmonizes the alternating current signal and outputs a pulse signal, a time measurement counter that counts the pulse signal from the harmonizing circuit, and measures a time that is a predetermined count, and more than the pulse signal An oscillator that outputs a clock signal having a high frequency and a constant frequency; and a pulse counter that counts the clock signal output from the oscillator with the time measured by the time measurement counter as a gate time and outputs this as a count number; The proximity or contact of the object to be detected with the sensor body due to a change in the number of counts from the pulse counter Sheet sensor apparatus according to claim 1 or 2, wherein and a contact determination unit to be detected.   When the object to be detected comes close to or comes into contact with the sensor body, it acts in the direction in which the count number of the pulse counter increases, and when the coaxial cable is bent, the count of the pulse counter The sheet-like sensor device according to claim 3, which acts in a direction in which the number decreases.   The detection means uses a capacitance between the inner conductor and the outer conductor of the coaxial cable at the time of system start-up such as power-on or power failure recovery as a reference value, and a difference between the reference value and the measured value is a predetermined threshold value. The sheet-like sensor device according to any one of claims 1 to 4, wherein the sensor detects proximity or contact of the detection target when the value exceeds.   6. The detection means adopts a reference value set at the previous system start-up when the reference value has already exceeded the threshold at the time of system start-up such as power-on or power failure recovery. The sheet-like sensor device according to the description.

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