JP2020177015A - Pressure-sensitive sensor - Google Patents

Abstract

To provide a pressure-sensitive sensor with which it is possible to significantly suppress material costs by a simple construction with pieces of electrode cloth vertically stacked one on another and measure a wide range of pressure distributions in a surface contact state stably while taking advantage of the flexibility of cloth, and with which the accuracy of measuring a pressurizing force in each intersection area is heightened.SOLUTION: A pressure-sensitive sensor 1 comprises: a first conductive face 2a1 formed on a first principal face 2a of a first electrode cloth 2, with a first conductive fiber yarn 4a exposed; a second conductive face 2b1 formed on a second principal face 2b of the first electrode cloth 2, with a second conductive fiber yarn 4b exposed; a third conductive face 3a1 formed on a third principal face 3a of a second electrode cloth 3, with a third conductive fiber yarn 4c exposed; and a fourth conductive face 3b1 formed on a fourth principal face 3b of the second electrode cloth 3, with a fourth conductive fiber yarn 4d exposed. The first principal face 2a of the first electrode cloth 2 and the fourth principal face 3b of the second electrode cloth 3 are in contact, and an intersecting area V1 of the second conducive face 2b1 and the third conductive face 3a1 is formed in shape of a matrix arrangement.SELECTED DRAWING: Figure 1

Description

The present invention relates to a pressure sensitive sensor that measures biological information.

In recent years, pressure sensors have been used for the purpose of medical care and health promotion. As an example, a pressure sensor is used to measure the pressure distribution of a sleeping posture on a bed and the pressure distribution of a sitting posture on a chair or the like as biological information. In such applications where biological information is measured by contacting the body, a pressure-sensitive sensor that can measure a wide range of pressure distribution with a large size corresponding to the body is required while having flexibility that does not cause discomfort to the body. Has been done.

Conventionally, a pressure-sensitive sheet has been proposed in which an intermediate cloth whose electrical characteristic value changes depending on a pressing force is sandwiched between a first electrode cloth and a third electrode cloth, which are coated with conductive noble metal particles. Patent Document 1: See US Pat. No. 8,966,997). Further, a pressure-sensitive sheet having a structure in which an intermediate mixture whose resistance value changes depending on a load is sandwiched between an upper cloth and a lower cloth having a conductive thread has been proposed (Patent Document 2: Japanese Patent Application Laid-Open No. 2004-132765). ).

U.S. Pat. No. 8,966,997 Japanese Unexamined Patent Publication No. 2004-132765

Since the pressure-sensitive sheet described in Patent Document 1 requires an intermediate cloth for detecting the pressing force, the material cost is increased by that amount, and the intermediate cloth is arranged between the electrode cloths. As a result, the original flexibility of the cloth is impaired and the weight increases. When plating conductive noble metal particles on a cloth, it is necessary to remove oil from the cloth, apply a catalyst, activate the surface of the cloth, etc. in advance, which complicates the treatment process and causes damage to the cloth. I am concerned. In addition, the size of the cloth is constrained by the size of the plating equipment, making it difficult to produce large size pressure sensitive sheets. Further, since the pressure-sensitive sheet described in Patent Document 2 requires an intermediate mixture for detecting the pressing force, the material cost is increased by that amount, and the intermediate mixture is arranged in a matrix between the electrode cloth and the electrode cloth. As a result, the original flexibility of the cloth is impaired and the weight increases. Then, the resistance value in the length direction of the thin conductive yarn becomes a noise component with respect to the resistance value of the intermediate mixture, and the resistance value fluctuation becomes large. As a result, there is a problem that the reproducibility of the pressure sensitive resistance is poor and a desired measurement cannot be performed. Further, when the size of the cloth is increased, a huge number of intermediate mixtures must be arranged in a matrix, which makes it difficult to manufacture a pressure-sensitive sheet having a large size.

The present invention has been made in view of the above circumstances, and the material cost is significantly reduced by eliminating the intermediate cloth and the intermediate mixture for detecting the pressing force, and the electrode cloth is superposed on the upper and lower sides, and the cloth is flexible. It is an object of the present invention to provide a pressure-sensitive sensor having a configuration in which a wide range of pressure distribution can be stably measured in a state of surface contact while taking advantage of the property, and the measurement accuracy of the pressure applied in each intersection region is improved. ..

The present invention solves the above problems by a solution disclosed below as an embodiment.

The pressure-sensitive sensor according to the present invention has a first electrode cloth and a second electrode cloth, and the first conductive surface is formed by the first conductive fiber thread exposed on the first main surface of the first electrode cloth. The second conductive surface is formed by the second conductive fiber yarn exposed on the second main surface of the first electrode cloth, and the third conductive surface exposed on the third main surface of the second electrode cloth. The third conductive surface is formed by the fiber thread, the fourth conductive surface is formed by the fourth conductive fiber thread exposed on the fourth main surface of the second electrode cloth, and the second conductive surface is formed. The intersection region between the first conductive surface and the third conductive surface is formed in a matrix arrangement, and the first conductive surface and the fourth conductive surface are in contact with each other, and the first conductive surface and the third conductive surface are in contact with each other. , The second conductive surface and the fourth conductive surface are in contact with each other, and the electric resistance per unit length of the first conductive fiber yarn is per unit length of the second conductive fiber yarn. It is higher than the electric resistance of the third conductive fiber yarn and higher than the electric resistance per unit length of the third conductive fiber yarn, and the electric resistance per unit length of the fourth conductive fiber yarn is higher. It is characterized in that it is higher than the electric resistance per unit length of the third conductive fiber yarn.

According to this configuration, the material cost is significantly reduced by the simple configuration in which the first electrode cloth and the second electrode cloth are vertically overlapped, and the flexibility of the cloth is utilized while the wide range of pressure distribution is surface-contacted. The configuration is such that stable measurement can be performed in the state and the measurement accuracy of the pressing force in each intersecting region is improved.

According to the present invention, the material cost can be significantly reduced, and the alignment error can be eliminated by integrating the electrode cloth and the pressure-sensitive cloth. Then, while taking advantage of the flexibility of the cloth, a wide range of pressure distribution can be stably measured in a state of surface contact, and the pressure measurement accuracy in each intersecting region is improved.

FIG. 1 is a structural development view schematically showing an example of arrangement of the first electrode cloth and the second electrode cloth in the intersection region of the pressure sensor of the first example in the first embodiment from a perspective view. FIG. 2 is a structural development view schematically showing an example of arrangement of the first electrode cloth and the second electrode cloth in the intersecting region of the pressure sensor of the second example in the first embodiment from a perspective view. FIG. 3 is a structural development view schematically showing an example of arrangement of the first electrode cloth and the second electrode cloth in the intersecting region of the pressure sensor of the third example in the first embodiment from a perspective view. FIG. 4 is a diagram schematically showing an example of a front surface and a back surface when the first electrode cloth and the second electrode cloth are woven fabrics. FIG. 5 is a diagram schematically showing other examples of the front surface and the back surface when the first electrode cloth and the second electrode cloth are woven fabrics. FIG. 6 is a diagram schematically showing an example of a front surface and a back surface when the first electrode cloth and the second electrode cloth are knitted. FIG. 7 is a schematic plan view showing an example of the pressure sensor of the first embodiment, and is a diagram showing a state in which a controller is connected. FIG. 8 is a schematic plan view showing another example of the pressure sensor of the first embodiment, and is a diagram showing a state in which a controller is connected. FIG. 9 is a schematic plan view showing an example of the pressure sensor of the second embodiment, and is a diagram showing a state in which a controller is connected. FIG. 10A is a schematic perspective view showing an example in which the pressure sensitive sensor is sewn on the cover cloth, and FIG. 10B is a schematic cross-sectional view showing a part of FIG. 10A in an enlarged manner. FIG. 11A is a schematic cross-sectional view showing a part of a state in which a bobbin thread is passed through a loop-shaped upper thread penetrating the first electrode cloth and the second electrode cloth by a sewing machine and a knot is formed. FIG. 11B is shown in FIG. 11A. Subsequently, it is a schematic cross-sectional view showing a part of the state in which the knot is arranged between the first electrode cloth and the second electrode cloth by pulling up the knot, and FIG. 11C is a first sectional view following FIG. 11B. It is a schematic cross-sectional view which shows a part of the sewn state by repeating the work of tying a knot while moving the electrode cloth and the second electrode cloth in a predetermined direction. FIG. 12 is a schematic perspective view showing a state in which the pressure sensor of the first embodiment is sewn. FIG. 13 is a schematic plan view of FIG. 12 and is a diagram showing a state in which a controller is connected. FIG. 14 is a schematic perspective view showing a state in which the pressure sensor of the second embodiment is sewn. FIG. 15 is a schematic plan view of FIG. 14 and is a diagram showing a state in which a controller is connected. FIG. 16 is a diagram showing an example of FIG. 4 as an image.

(First Embodiment)
Hereinafter, the first embodiment of the present invention will be described in detail with reference to the drawings. FIG. 12 is a schematic perspective view showing the pressure sensor 1 of the first embodiment. 7, 8 and 13 are schematic plan views showing a state in which the controller 7 is connected to the pressure sensor 1. The present embodiment is configured by superimposing the first electrode cloth 2 and the second electrode cloth 3. For convenience of explanation, the cover cloth, signal wiring, etc. may be omitted. Here, in all the drawings for explaining the embodiment, members having the same function may be designated by the same reference numerals, and the repeated description thereof may be omitted. The first main surface 2a and the second main surface 2b of the first electrode cloth 2 are in a front-to-back relationship with each other. Similarly, the third main surface 3a and the fourth main surface 3b of the second electrode cloth 3 are in a front-to-back relationship with each other.

1 to 3 are structural development views schematically showing an arrangement example of the first electrode cloth 2 and the second electrode cloth 3 in the intersection region V1 of the pressure sensor 1 of the present embodiment. FIG. 1 is an example of a configuration in which the first conductive surface 2a1 and the fourth conductive surface 3b1 are in contact with each other. FIG. 2 is an example of a configuration in which the first conductive surface 2a1 and the third conductive surface 3a1 are in contact with each other. FIG. 3 is an example of a configuration in which the second conductive surface 2b1 and the fourth conductive surface 3b1 are in contact with each other. The formation of the first conductive surface 2a1, the second conductive surface 2b1, the third conductive surface 3a1 and the fourth conductive surface 3b1 is, for example, a structure in which the conductive fiber threads are entwined with each other, a structure in which the conductive fiber threads are sewn diagonally. A configuration in which the conductive fiber threads are diagonally tied and other known methods are applied.

In the examples shown in FIGS. 4, 5 and 16, the first electrode cloth 2 and the second electrode cloth 3 are woven fabrics. Woven fabrics are manufactured, for example, by horizontal looms, vertical looms or jacquard looms. The woven fabric is, for example, a plain weave, a twill weave, a twill weave, a satin weave, a double weave, a jacquard, a lame, a goblin, a pile, a velvet, a towel, a moquette, or a layered structure to which a known weave is applied. , So-called three-dimensional three-dimensional structure. The example is not limited to the illustrated example.

In the examples shown in FIGS. 4 and 16, the first conductive surface 2a1 and the fourth conductive surface 3b1 are in contact with each other to form an electric circuit. In this example, on the first main surface 2a, the first insulating line having the first non-conductive fiber thread 5a has a lattice pattern, and the fourth main surface 3b is the fourth non-conductive fiber thread 5d. The fourth insulating line having the above is the same as or corresponding to the first main surface 2a. Further, in this example, on the second main surface 2b, the second insulating line having the second non-conductive fiber thread 5b has a vertical stripe pattern or a horizontal stripe pattern, and the third main surface 3a has a third non-third non-conductive line. The third insulating line having the conductive fiber thread 5c has a pattern that is the same as or corresponds to the second main surface 2b. According to this configuration, the intersecting region V1 between the second conductive surface 2b1 and the third conductive surface 3a1 can be easily formed in a regular grid-like matrix arrangement, and the first conductive surface 2a1 and the fourth conductive surface 3b1 can be easily formed. It is possible to easily suppress the variation in the electric resistance in the electric circuit by making the contact area with which the light comes into contact constant. Here, the first non-conductive fiber thread 5a and the second non-conductive fiber thread 5b may be the same thread or may be different threads. Further, here, the third non-conductive fiber thread 5c and the fourth non-conductive fiber thread 5d may be the same thread or may be different threads.

As shown in FIG. 16, in the first main surface 2a, when the weft is the first conductive fiber yarn 4a and the warp yarn is the first non-conductive fiber yarn 5a, the weft yarn is regularly skipped with respect to the warp yarn. The woven structure has an increased exposure of the first conductive fiber yarn 4a, and the fourth main surface 3b has the weft yarn as the fourth conductive fiber yarn 4d and the warp yarn as the fourth non-conductive fiber yarn 5d. In this case, the weft yarns are regularly skipped with respect to the warp yarns to increase the exposure of the fourth conductive fiber yarn 4d. Then, a plurality of conductive lines in which the warp yarn is the second conductive fiber yarn 4b (third conductive fiber yarn 4c) and the weft yarn is the first conductive fiber yarn 4a (fourth conductive fiber yarn 4d) are arranged in close proximity to each other. The second conductive surface 2b1 is formed. Examples of the weaving structure include double weave, diagonal weave, twill weave, and satin weave. According to this configuration, the contact area between the first conductive fiber thread 4a and the fourth conductive fiber thread 4d when the first electrode cloth 2 and the second electrode cloth 3 are cross-arranged at 90 degrees is increased. Therefore, it becomes a high-performance pressure-sensitive sensor 1 with little variation in sensitivity characteristics and high reproducibility by contact. Note that FIG. 16 is an example and is not limited to this example. Here, the first conductive fiber thread 4a and the fourth conductive fiber thread 4d may be the same thread or may be different threads. Further, the second conductive fiber thread 4b and the third conductive fiber thread 4c may be the same thread or may be different threads. The weft and warp are in a relative relationship, and the relationship may be interchanged depending on the type of loom.

In the example shown in FIG. 6, the first electrode cloth 2 and the second electrode cloth 3 are knitted fabrics. The knitting is, for example, a weft knitted by a flat knitting machine, a full fashion knitting machine or a circular knitting machine. As an example, the weft knitting is a layered structure to which flat knitting, rubber knitting, pearl knitting, tack knitting, pile knitting, jacquard knitting, and other known weft knitting are applied, and has a so-called three-dimensional structure. .. Further, the knitting is, for example, a warp knitting machine knitted by a tricot knitting machine, a Russell knitting machine, a crochet knitting machine or a Milanese knitting machine. As an example, the warp knitting is a layered organization to which tricot, satin, inlay, Russell, double Russell, crochet, chain, atlas, mirannies, and other known warp are applied. , So-called three-dimensional structure. The example is not limited to the illustrated example.

In the present embodiment, the first conductive fiber thread 4a is exposed on the first main surface 2a of the first electrode cloth 2 to form the first conductive surface 2a1, and the second main surface 2b of the first electrode cloth 2 is formed. The second conductive fiber thread 4b is exposed and the second conductive surface 2b1 is formed. Further, the third conductive fiber thread 4c is exposed on the third main surface 3a of the second electrode cloth 3 to form the third conductive surface 3a1, and the fourth main surface 3b of the second electrode cloth 3 is formed. The conductive fiber thread 4d is exposed to form the fourth conductive surface 3b1. Moreover, the intersecting region V1 between the second conductive surface 2b1 and the third conductive surface 3a1 is formed in a matrix arrangement.

The average of the electrical resistances of the first conductive surface 2a1 and the second conductive surface 2b1 in the thickness direction when an external force of 10 [kPa] is applied in the compression direction in which the first electrode cloth 2 and the second electrode cloth 3 approach each other. With respect to the value Rc, the average value R1 of the electrical resistance in the longitudinal direction of the first conductive surface 2a1 and the average value R2 of the electrical resistance in the longitudinal direction of the second conductive surface 2b1 can satisfy the following equation (1). preferable.
(Number 1)
R2 << Rc << R1 ... (1)

According to this configuration, when detecting the pressing force, it is possible to prevent a short circuit between the electrodes and prevent crosstalk with an adjacent intersecting region, so that the S / N ratio can be improved. As an example, the ratio to the resistance value R1 which is the average value of the resistance in the longitudinal direction of the first conductive surface 2a1 when the resistance value R2 which is the average value of the resistance in the longitudinal direction of the second conductive surface 2b1 is used as a reference is 1. : By setting it to more than 300, you can take advantage of the flexibility of the cloth that does not make you feel uncomfortable. As an example, even if the resistance values of 30 lines are accumulated as electric signal lines, the influence of the accumulation of electric resistance on the measured resistance can be less than 1/10.

In the present embodiment, the electric resistance per unit length of the first conductive fiber thread 4a is higher than the electric resistance per unit length of the second conductive fiber thread 4b, and the third conductive fiber It is higher than the electrical resistance per unit length of the thread 4c. The second conductive fiber thread 4b is exposed only on the second main surface 2b of the first electrode cloth 2. Further, the electric resistance per unit length of the fourth conductive fiber thread 4d is higher than the electric resistance per unit length of the third conductive fiber thread 4c. The third conductive fiber thread 4c is exposed only on the third main surface 3a of the second electrode cloth 3. According to this configuration, the material cost is significantly reduced by a simple configuration in which the first electrode cloth 2 and the second electrode cloth 3 are vertically overlapped, and the flexibility of the cloth is utilized to provide a wide range of pressure distribution. The configuration is such that stable measurement can be performed in the state of contact, and the measurement accuracy of the pressing force in each intersection region V1 is improved.

The first electrode cloth 2 and the second electrode cloth 3 may each have non-conductive fiber threads. As an example, the non-conductive fiber yarn is a synthetic yarn containing any one or more of polyester, polyamide, nylon, rayon, acrylic and polyurethane. Since it has a non-conductive fiber yarn, it has a structure that is soft to the touch and has excellent chemical resistance. In order to reduce the contact resistance and secure the strength required as a pressure sensor while utilizing the flexibility of the cloth, the non-conductive fiber yarn is preferably multifilament. As an example, non-conductive fiber yarns are 20-200 denier.

The first conductive fiber thread 4a, the second conductive fiber thread 4b, the third conductive fiber thread 4c, and the fourth conductive fiber thread 4d are made of polyester, polyamide, nylon, rayon, acrylic, or polyurethane, respectively. It has a synthetic yarn containing, and the synthetic yarn has conductivity of any one or more of conductive carbon black, conductive polymer compound, silver, nickel, nickel alloy, copper, copper alloy, copper sulfide, aluminum or aluminum alloy. A structure coated with a sex material is preferable. As an example, the second conductive fiber yarn 4b and the third conductive fiber yarn 4c each contain a synthetic yarn containing at least one of polyester, polyamide, nylon, rayon, acrylic or polyurethane as a core yarn, and the polyester yarn and polyamide. A covering yarn in which the yarn or nylon yarn is covered with a silver-coated yarn. According to this configuration, excellent elasticity can be provided. Plating, vapor deposition, and other known coating methods are applied to the coating. As an example, the second conductive fiber yarn 4b and the third conductive fiber yarn 4c are woolly processed yarns in which polyester yarn, polyamide yarn or nylon yarn is coated with silver and woolly processed, respectively. According to this configuration, excellent elasticity can be provided, and the surface area can be increased to improve contactability.

When a conductive metal is applied to the second conductive fiber yarn 4b and the third conductive fiber yarn 4c, the thickness of the conductive metal is preferably 1% or more and 10% or less with respect to the diameter of the coated yarn. According to this configuration, flexibility can be ensured while suppressing the resistance value in the length direction of the thread to be coated. Similarly, when a conductive metal is applied to the first conductive fiber yarn 4a and the fourth conductive fiber yarn 4d, the thickness of the conductive metal is 0.01% or more with respect to the diameter of the coated yarn. % Or less is preferable. In particular, since silver has excellent ductility, a conductive thin film can be formed, and silver ions have an excellent antibacterial action because they show strong bactericidal activity against various germs such as bacteria. As an example, the second conductive fiber thread 4b and the third conductive fiber thread 4c are made of the same material or the same kind of material. As an example, the second conductive fiber yarn 4b and the third conductive fiber yarn 4c are warp yarns.

As an example, conductive carbon black is applied to the first conductive fiber thread 4a and the fourth conductive fiber thread 4d. The size of the conductive carbon black is preferably any one or more of Ketjen black, acetylene black, channel black and furnace black having an average primary particle size of 100 [nm] or less. According to this configuration, the cloth has excellent scratch resistance and flexibility. As an example, the first conductive fiber thread 4a and the fourth conductive fiber thread 4d are synthetic threads coated with copper sulfide. According to this configuration, the cloth has excellent scratch resistance and flexibility. As an example, the first conductive fiber yarn 4a and the fourth conductive fiber yarn 4d are weft yarns.

As an example, the first conductive fiber thread 4a and the second conductive fiber thread 4b and / or the third conductive fiber thread 4c and the fourth conductive fiber thread 4d are made of the same material or the same kind of material, and the conductive material is used. The coat thickness of the sex material is different. As a more specific example, the base yarn is a 50 denier nylon yarn, and the second conductive fiber yarn 4b and the third conductive fiber yarn 4c have a thickness of 2 to 3 [μm] on the surface of the base yarn. The first conductive fiber yarn 4a and the fourth conductive fiber yarn 4d are formed by subjecting the surface of the base material yarn to silver plating of 50 to 200 [nm]. According to this configuration, conductive fiber yarns of the same material having different electric resistances can be formed, and since they can be manufactured by the same manufacturing method, the number of parts can be significantly reduced and the fiber yarns can be manufactured. The combination of electrical resistances between them is simplified and the pressure sensitive sensor 1 can be easily configured. As an example, the first electrode cloth 2 and the second electrode cloth 3 are made of the same material or the same material. According to this configuration, the number of parts can be significantly reduced, and the combination of electrical resistance between the cloths is simplified, so that the pressure-sensitive sensor 1 can be easily configured.

In the present embodiment, the first electrode cloth 2 has a plurality of second conductive surfaces 2b1 formed at the first interval 2c, and the second electrode cloth 3 has a plurality of third conductive surfaces 3a1 formed at the second interval 3c. The third conductive surface 3a1 and the second conductive surface 2b1 are arranged so as to intersect with each other to form an intersecting region V1. As an example, the number of parts can be halved by making the first electrode cloth 2 and the second electrode cloth 3 the same.

10A and 10B are examples of a configuration in which the pressure sensitive sensor 1 is sewn on the cover cloth 8a and the cover cloth 8b. The first electrode cloth 2 is sewn to the cover cloth 8a by the suture thread 9a, and the second electrode cloth 3 is sewn to the cover cloth 8b by the suture thread 9b. Then, as an example, the four corners of the cover cloth 8a and the cover cloth 8b are sewn, hooked, eyelets, hook-and-loop fasteners, and other known methods are assembled and integrated. That is, the first electrode cloth 2 and the second electrode cloth 3 are sewn to the inside of the cover cloths 8a and 8b by the suture threads 9a and 9b, respectively, and face each other. With this configuration, it is possible to prevent the displacement of the measurement area and to measure the pressing force stably while utilizing the flexibility of the cloth. The structure is not limited to the above. For example, the bag-shaped cover cloth is turned inside out, the first electrode cloth 2 and the second electrode cloth 3 are sewn inside the cover cloth with a suture, and the cover cloth is turned over. As a result, the pressure sensitive sensor 1 can be integrated with the cover cloth.

Further, the first electrode cloth 2 and the second electrode cloth 3 may be sewn to each other by the suture thread 9c. According to this configuration, since the first electrode cloth 2 and the second electrode cloth 3 are sewn and integrated, the position shift of the measurement area is prevented, and stable pressing force is utilized while utilizing the flexibility of the cloth. Can be measured. Moreover, the pressure distribution over a wide range can be made into a measurable size. Then, stable pressing force can be measured in the state of surface contact, and the structure becomes highly productive while suppressing the material cost. Further, since the position of the boundary of the crossing region V1 is stabilized by sewing, the measurement accuracy of the pressing force in each crossing region V1 can be improved.

11A, 11B, and 11C are schematic cross-sectional views illustrating a procedure for sewing the first electrode cloth 2 and the second electrode cloth 3 to each other by a sewing machine. As an example, in the case of lockstitching, a knot is formed by passing a bobbin thread (sewn thread 9c) through a loop-shaped upper thread (sewn thread 9c) penetrating the first electrode cloth 2 and the second electrode cloth 3 by a sewing machine. (FIG. 11A), the knot is pulled up so that the knot is arranged between the first electrode cloth 2 and the second electrode cloth 3 (FIG. 11B), and the first electrode cloth 2 and the second electrode cloth 3 are placed together. The work of tying a knot is repeated while moving the cloth in a predetermined direction (FIG. 11C). When the first electrode cloth 2 and the second electrode cloth 3 are sewn with a sewing machine, the sewing procedure is the same as described above. Sewing is, for example, a sewing machine or hand-sewn. As an example, lockstitch, chain stitch, overlock stitch, flat stitch, and other known sewing methods are applied to the sewing. The part where the suture thread 9c is sewn becomes a non-stretchable seam, and a dead zone is formed to suppress the fluctuation of the resistance value in the part other than the intersection area V1. Therefore, the intersection area V1 is formed in a matrix arrangement and individually. It facilitates functioning as an independent pressure cell for extracting electrical signals.

The sutures 9a, 9b, and 9c are made of synthetic fibers such as nylon, polyester, rayon, acrylic, and polyamide, and natural fibers such as cotton and linen, for example. As an example, the sutures 9a, 9b, 9c have a thickness of 20 to 200 denier.

7, 8 and 13 are schematic plan views showing an example of the pressure sensor 1 of the first embodiment, and are views in a state where the controller 7 is connected. The controller 7 includes a signal wiring switching circuit, a signal detector, an A / D converter, a semiconductor memory, an arithmetic circuit, and a CPU that controls these. The pressure-sensitive sensor 1 is scanned at a frequency of 10 to 100 [Hz] as an example by a switching circuit built in the controller 7, and the resistance value of the intersection region V1 formed in the matrix arrangement is individually signal-detected on the order of millisecond. Detected by a device, A-D converted by an A / D converter, stored in data by a semiconductor memory, calculated by an arithmetic circuit, and finally a pressure value or pressure distribution, or an external display device as a pressure value and pressure distribution. Is displayed in. As an example, a personal computer having a built-in interface board for signal connection with the pressure sensitive sensor 1 can be applied to the controller 7 and the display device.

In this embodiment, as an example, a [m] number of second conductive surfaces 2b1 arranged on the first main surface 2a of the first electrode cloth 2 at a first interval of 2c, and a fourth main surface of the second electrode cloth 3 The 3b is provided with [n] number of third conductive surfaces 3a1 arranged at a second interval 3c in a direction intersecting the second conductive surface 2b1, and the intersection region V1 between the third conductive surface 3a1 and the third conductive surface 3a1. Is formed in a matrix arrangement. Here, [m] and [n] are natural numbers of 2 or more, respectively, and in the example of FIG. 13, m = 5 and n = 6.

In this embodiment, as an example, the second conductive surface 2b1 is signal-connected by the conductive first terminals 6a arranged at predetermined intervals at the ends of the first electrode cloth 2, and the second electrode cloth 3 is used. The third conductive surface 3a1 is signal-connected by the conductive second terminal 6b arranged one-to-one with the first terminal 6a at the end of the above. With this configuration, signal connection to an external device such as the controller 7 can be easily performed. Further, the example shown in FIG. 8 has a configuration in which the resolution can be set according to the sizes of the first terminal 6a and the second terminal 6b. As a result, as an example, the resolution of the central portion with respect to the peripheral portion can be increased, and high-precision sensing corresponding to the body can be easily performed.

As an example, the first terminal 6a and the second terminal 6b are made of a conductive metal such as brass, aluminum, an aluminum alloy, stainless steel, nickel, a nickel alloy, copper, or a copper alloy. Further, as an example, eyelets, clips, caulking terminals, and other known terminals can be applied. As an example, the first terminal 6a and the second terminal 6b have a "U-shape" when viewed from the side. According to this configuration, not only can the connection with the controller 7 be easily made, but also a plurality of second conductive fiber threads 4b on the second conductive surface 2b1 can be collectively electrically connected by contact, and the third conductive surface 3a1 can be connected. Since a plurality of third conductive fiber threads 4c can be electrically connected together by contact, the pressure-sensitive sensor 1 has excellent electrical connection reliability. By reducing the size of the first terminal 6a and the second terminal 6b, the number of connections with the second conductive fiber thread 4b and the third conductive fiber thread 4c can be reduced and the resolution can be improved. The spatial resolution of the pressure sensor 1 can be easily changed.

As an example, the pressure sensor 1 having a size suitable for a bed size having a width of 900 [mm] and a length of 1800 [mm] can be used. In this case, the first electrode cloth 2 having an electrode stripe of 25 [mm] and an insulating stripe having a stripe pitch of 35 [mm] and an electrode stripe having a stripe pitch of 25 [mm] and an insulating stripe having a stripe pitch of 35 [mm]. By superimposing the second electrode cloth 3 on the top and bottom, a pressure sensitive sensor 1 capable of measuring the pressure distribution can be obtained by providing 450 pressure sensitive cells having a side of 25 [mm] in the intersecting region. By making the insulating stripe wider than the electrode stripe in this way, the amount of the conductive fiber thread used can be reduced and the cost can be further reduced. Then, by sewing the first electrode cloth 2, the conductive cloth, and the second electrode cloth 3 with the non-conductive suture thread 9c in the area of the insulating stripe, the first electrode cloth 2 and the second electrode cloth 3 are sewn together. A large-sized pressure-sensitive sensor 1 that prevents misalignment and has excellent reproducibility of pressure-sensitive characteristics can be obtained.

(Second embodiment)
Subsequently, the second embodiment will be described below. 9 and 15 are schematic plan views showing an example of the pressure sensor 1 of the second embodiment, and are views in a state where the controller 7 is connected. In the second embodiment, the differences from the first embodiment will be mainly described.

In this embodiment, as an example, [m] number of first electrode cloths 2 are arranged at a first interval of 2c, and [n] number of second electrode cloths 3 are arranged in a direction intersecting with the first electrode cloth 2. The crossing region V1 is formed by being arranged at the second interval 3c. Here, [m] and [n] are natural numbers of 2 or more, respectively, and in the example of FIG. 15, m = 5 and n = 6. According to this configuration, by making the first electrode cloth 2 and the second electrode cloth 3 into a narrow woven fabric or a narrow knit, respectively, the weight is reduced and the material cost is suppressed, and the productivity is high. As an example, the number of parts can be halved by making the first electrode cloth 2 and the second electrode cloth 3 the same.

As shown in FIG. 9, as an example, a vibration sensor 11 made of a piezoelectric element or the like is configured to be connected to an electric circuit in the pressure sensor 1 so that a signal can be taken out, so that the pressure distribution and heartbeat / breathing can be performed with high accuracy. It can be easily sensed. Further, as an example, the pressure distribution and the temperature / humidity distribution can be made high by configuring the temperature sensor 11 composed of a thermocouple or the like, the humidity sensor 11 or the like so as to be connected to the electric circuit in the pressure sensor 1 so that the signal can be taken out. Sensing with accuracy can be easily performed. That is, as an example, the electric circuit in the pressure sensor 1 preferably has a configuration in which any one or more of a vibration sensor, a temperature sensor, and a humidity sensor are connected so that signals can be taken out. Various sensors such as a vibration sensor, a temperature sensor, and a humidity sensor are arranged in a space formed in a space other than the intersection region of the band-shaped first electrode cloth 2 and the band-shaped second electrode cloth 3, which saves space and is rational. It becomes a hybrid sensor with a typical arrangement configuration.

The pressure-sensitive sensor 1 described above can be applied to a bed, a bed mat, sheets, a mat, a cushion, a chair mat, a health mat, and a carpet as an example. As an example, by incorporating the pressure sensor 1 into a bed, a bed mat, sheets or a mat, it is possible to measure a person's sleeping appearance at bedtime and to promote turning over by adjusting the air pressure of the air mat to prevent pressure ulcers. It is also possible to measure heartbeat, respiration, etc. as a heartbeat sensor or respiration sensor by analyzing and calculating the pressure waveform of a predetermined portion. As an example, by incorporating the pressure sensor 1 into the cushion or chair mat, the posture is corrected by measuring the sitting posture of a person, detecting the leaving of the seat to grasp the movement of the person, adjusting the air pressure of the air cushion, and the like. It can prevent stiff shoulders and back pain. As an example, by incorporating the pressure sensor 1 into a health mat or carpet, it is possible to customize shoes corresponding to the subject by measuring the walking posture of a person or measuring the foot pressure in a standing position. It is also possible to measure the weight of a person from the contact resistance, and it can also be applied to the measurement of lifestyle habits such as movement of a person in a room. In general, in pressure distribution measurement in a chair or bed, the measurement range by the pressure sensor 1 can be sufficiently measured when the pressing force is 2 to 40 [kPa]. The frequency of measurement by the pressure sensor 1 is high when the pressing force is around 10 [kPa].

In the above embodiment, it has been described that the fourth conductive fiber thread 4d is exposed on the fourth main surface 3b of the second electrode cloth 3 to form the fourth conductive surface 3b1, but the present invention is not limited to this configuration. In the case where the first main surface 2a of the first electrode cloth 2 and the third main surface 3a of the second electrode cloth 3 are in contact with each other, there is no particular problem even if the fourth conductive fiber thread 4d is omitted.

The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the present invention. The shape and size of the pressure sensitive sensor 1 may be appropriately changed according to the specifications of known beds, bed mats, sheets, mats, cushions, chair mats, health mats, carpets, and the like.

1 Pressure-sensitive sensor 2 1st electrode cloth 2a 1st main surface 2a1 1st conductive surface 2b 2nd main surface 2b1 2nd conductive surface 2c 1st interval 3 2nd electrode cloth 3a 3rd main surface 3a1 3rd conductive surface 3b 4 Main surface 3b1 4th conductive surface 3c 2nd interval 4a 1st conductive fiber thread 4b 2nd conductive fiber thread 4c 3rd conductive fiber thread 4d 4th conductive fiber thread 5a 1st non-conductive fiber thread 5b 2 Non-conductive fiber thread 5c 3rd non-conductive fiber thread 5d 4th non-conductive fiber thread 6a 1st terminal 6b 2nd terminal 7 Controller 8a, 8b Cover cloth 9a, 9b, 9c Suture thread V1 Crossing region

Claims (17)

It has a first electrode cloth and a second electrode cloth,
The first conductive surface is formed by the first conductive fiber thread exposed on the first main surface of the first electrode cloth, and the second conductive fiber thread exposed on the second main surface of the first electrode cloth. The second conductive surface is formed, and the third conductive surface is formed by the third conductive fiber thread exposed on the third main surface of the second electrode cloth, and the fourth main surface of the second electrode cloth is formed. The fourth conductive surface is formed by the fourth conductive fiber thread exposed to the surface, and the intersecting region between the second conductive surface and the third conductive surface is formed in a matrix arrangement.
Any of a configuration in which the first conductive surface and the fourth conductive surface are in contact, a configuration in which the first conductive surface and the third conductive surface are in contact, and a configuration in which the second conductive surface and the fourth conductive surface are in contact with each other. And
The electric resistance per unit length of the first conductive fiber yarn is higher than the electric resistance per unit length of the second conductive fiber yarn, and per unit length of the third conductive fiber yarn. The electrical resistance per unit length of the fourth conductive fiber yarn is higher than the electrical resistance per unit length of the third conductive fiber yarn. A pressure-sensitive sensor featuring. The second conductive fiber thread is exposed only on the second main surface of the first electrode cloth, and the third conductive fiber thread is exposed only on the third main surface of the second electrode cloth. The pressure-sensitive sensor according to claim 1, wherein the pressure sensor is provided. The average value (Rc) of the electrical resistance in the thickness direction of the first conductive surface and the second conductive surface in a state where an external force of 10 kPa is applied in the compression direction in which the first electrode cloth and the second electrode cloth approach each other. ), The average value (R1) of the electrical resistance in the longitudinal direction of the first conductive surface and the average value (R2) of the electrical resistance in the longitudinal direction of the second conductive surface are expressed by the following equation (1). The pressure sensitive sensor according to claim 1 or 2, wherein the pressure sensitive sensor is satisfied.
(Number 1)
R2 << Rc << R1 ... (1) Claim 1 is characterized in that the average value (R1) of the electrical resistance in the longitudinal direction of the first conductive surface is more than 300 times the average value (R2) of the electrical resistance in the longitudinal direction of the second conductive surface. The pressure-sensitive sensor according to any one of 3 to 3. The pressure-sensitive sensor according to any one of claims 1 to 4, wherein an electric circuit is formed by abutting the first conductive surface and the fourth conductive surface. On the first main surface, the first insulating line having the first non-conductive fiber yarn has a lattice pattern.
On the second main surface, the second insulating line having the second non-conductive fiber yarn has a vertical stripe pattern or a horizontal stripe pattern.
The third main surface has a pattern in which the third insulating line having the third non-conductive fiber yarn is the same as or corresponds to the second main surface.
The pressure-sensitive sensor according to claim 5, wherein the fourth main surface has a pattern in which a fourth insulating line having a fourth non-conductive fiber thread has the same or a pattern corresponding to the first main surface. When the weft is the first conductive fiber yarn and the warp is the first non-conductive fiber yarn, the first main surface is such that the weft is regularly skipped with respect to the warp and the first conductive fiber. It is a woven structure in which the exposure of the yarn is increased, and the fourth main surface uses the weft as the warp when the weft is used as the fourth conductive fiber and the warp is used as the fourth non-conductive fiber. The pressure-sensitive sensor according to claim 6, wherein the woven structure has a woven structure in which the exposure of the fourth conductive fiber yarn is increased by regularly skipping the yarn. The pressure-sensitive sensor according to any one of claims 5 to 7, wherein the electric circuit is connected to any one or more of a vibration sensor, a temperature sensor, and a humidity sensor so as to be able to take out a signal. The second conductive surface is signal-connected by conductive first terminals arranged at predetermined intervals at the ends of the first electrode cloth, and the first terminals are connected to the ends of the second electrode cloth. The pressure-sensitive sensor according to any one of claims 5 to 8, wherein the third conductive surface is signal-connected by a correspondingly arranged conductive second terminal. The pressure-sensitive sensor according to claim 9, wherein the resolution can be set according to the sizes of the first terminal and the second terminal. The first conductive fiber yarn, the second conductive fiber yarn, and the third conductive fiber yarn each have a synthetic yarn containing any one or more of polyester, polyamide, nylon, rayon, acrylic, and polyurethane. , The synthetic yarn is coated with one or more conductive materials such as conductive carbon black, conductive polymer compound, silver, nickel, nickel alloy, copper, copper alloy, copper sulfide, aluminum or aluminum alloy. The pressure-sensitive sensor according to any one of claims 1 to 10. The first conductive fiber thread and the second conductive fiber thread are made of the same material or the same kind of material, and the first conductive fiber thread and the second conductive fiber thread have a coating thickness of the conductive material. 11. The pressure-sensitive sensor according to claim 11, wherein the pressure-sensitive sensors are different from each other. The pressure-sensitive sensor according to any one of claims 1 to 12, wherein the second conductive fiber thread and the third conductive fiber thread are made of the same material or the same kind of material. The pressure-sensitive sensor according to any one of claims 1 to 13, wherein the first electrode cloth and the second electrode cloth are made of the same material or the same material. A plurality of the first electrode cloths are arranged at the first interval, and a plurality of the second electrode cloths are arranged at the second interval in a direction intersecting with the first electrode cloth to form the intersection region. The pressure-sensitive sensor according to any one of claims 1 to 14, wherein the pressure sensor is provided. The invention according to any one of claims 1 to 15, wherein the first electrode cloth and the second electrode cloth are sewn to the inside of the cover cloth by sutures and face each other. Pressure sensitive sensor. Claims 1 to 1, wherein the first electrode cloth is a knit having a non-conductive fiber thread, and the second electrode cloth is a knit having a non-conductive fiber thread. The pressure-sensitive sensor according to any one of 5.