JP2006284276A - Pressure-sensitive sensor sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To fulfill a sensor function for measuring a change with elapse of time of a pressure distribution on a two-dimensional plane, and both characteristics of executability and workability like adaptability to a curved surface when using a pressure-sensitive sensor structure, smoothness of the surface, or integration of the sensor structure, by a pressure-sensitive sensor or a pressure-sensitive sheet. <P>SOLUTION: Conductive threads having conductivity are arranged on both surfaces of an upper surface part and an under surface part of a multilayered structure fiber structure having a compression characteristic and a compression recovery characteristic. When the multilayered structure sheet is pressed, a bonding part for keeping the upper surface part and the lower surface part of the multilayered structure at a fixed interval is compressed, to thereby bring each conductive thread arranged on the upper surface part and the lower surface part into contact with each other. At that time, since an electric resistance between each conductive thread on both surfaces is changed, a pressure onto the multilayered structure sheet surface can be detected by detecting the change of the electric resistance. When the multilayered structure fiber structure constituting this pressure-sensitive sensor sheet is manufactured, the conductive thread is woven, knitted or sewn simultaneously. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention provides a pressure-sensitive sensor sheet used for detecting pressure in a two-dimensional plane, measuring pressure distribution, and measuring temporal changes in those pressures.

As a pressure distribution measurement method that can be applied to a free-form surface and integrated with a sheet, there is a film-like material “Prescale” commercially available from Fuji Photo Film Co., Ltd. However, since the principle is that the microcapsule is crushed by pressure to release the ink in the capsule and the compression pressure is measured from the crushed area, it is not possible to continuously measure the temporal change in pressure distribution using this method. Is possible. (See Patent Document 1)

Examples of the knitted fabric with a sensor function include a load cell or a small piezoelectric sensor arranged in a woven or knitted shape, or a pressure-sensitive conductive elastomer formed into a fiber shape to form a woven or knitted structure. . However, they have a structure in which hard protrusions are arranged on the surface of the woven or knitted fabric or a fiber shape with a large bending rigidity, so that the thickness of the structure itself is thick, and further, the flexibility of the structure is lacking. Is difficult to adapt, and it is not practical due to problems in handling, workability and workability. (See Non-Patent Document 1 and Patent Document 2)

  As a knitted or knitted fabric having a sensor function, there is one in which an electrode material is disposed and an object or a person is detected by a change in electrostatic capacity thereof. Although it is possible to detect the presence or absence of pressure, this requires a certain area or more for sensing, so measurement of a pressure distribution on a flat surface is not practical because of low resolution. (See Patent Document 3)

JP 2000-321152 A JP-A-6-323929 JP 2001-159683 A Japanese Journal of Textile Consumption, P57-62, Vol.40, No.9 (1999)

  The conventional pressure-sensitive film and pressure-sensitive sheet described above have both a sensor function for measuring the change in pressure distribution over time on a two-dimensional plane and the convenience of handling, construction and processing when using the sensor. It was impossible to meet.

In the present invention, by detecting the pressure using the principle of elastic characteristics of compression and recovery of the fiber structure, the fiber structure itself can have any shape-shaping property such as flexibility and thinning. It is possible to have a sensor function capable of continuous pressure detection and measurement of temporal changes in pressure distribution, as well as excellent workability and workability, and the conventional products described above had It solves the problem.

The pressure-sensitive sensor sheet according to the present invention includes an upper surface portion in which a plurality of conductive yarns are arranged in a plane direction at a predetermined interval, and a direction in which the plurality of conductive yarns intersect the conductive yarns in the upper surface portion at a predetermined interval in the surface direction. And a connecting portion that keeps a predetermined distance between the upper surface portion and the lower surface portion. When the connecting portion is compressed by pressing, the conductive yarn on the upper surface portion and the conductive yarn on the lower surface portion contact each other. It is characterized by becoming a state. Furthermore, the upper surface portion, the lower surface portion, and the connecting portion are formed of a fiber structure. Furthermore, the fiber structure is formed of a woven fabric. Furthermore, the fiber structure is formed of a knitted fabric. Furthermore, the upper surface portion and the lower surface portion have a multilayer structure.
A pressure distribution measuring device according to the present invention is a pressure-sensitive sensor sheet according to any one of the above, and electrically connected to each conductive yarn on the upper surface and electrically connected to each conductive yarn on the lower surface. Measuring means for measuring a conductive state between each conductive yarn of the portion and each conductive yarn of the lower surface portion.

The pressure-sensitive sensor sheet according to the present invention is a problem of detecting pressure with time change and measuring time change of pressure distribution, which is an upper surface portion of a multilayer structure fiber structure having compression characteristics and compression recovery characteristics. The problem is solved by arranging conductive yarns on both sides of the lower surface portion, and contacting the conductive yarn on the upper surface portion with the conductive yarn on the lower surface portion when the multilayer structure sheet is pressed. And when a multilayer structure sheet is pressed, the connection part which maintains the upper surface part and lower surface part of a multilayer structure at a fixed space | interval is compressed, and the electrically conductive thread arrange | positioned at an upper surface part and a lower surface part contacts. At this time, the electrical resistance between the conductive yarns on both sides changes, and the pressure on the surface of the multilayer structure sheet can be detected by detecting this electrical resistance change. In addition, the pressure change can be detected accurately and quickly because the upper surface conductive yarn and the lower surface conductive yarn are quickly separated by the compression recovery characteristics of the multilayer structure fiber structure after the pressure is released. .

The pressure-sensitive sensor sheet of the present invention has a structure in which the pressure sensor and the sheet are integrated because the conductive yarn is simultaneously woven, knitted or sewn during the production of the multilayer structure fiber structure constituting the sheet, and is easy to handle.

Since the pressure-sensitive sensor sheet of the present invention is composed of a fiber structure such as a woven fabric and a knitted fabric, it has flexibility and stretchability, which are characteristics of the fiber structure, and is bonded along the curved surface of the flexible three-dimensional object. Excellent workability and workability.

The pressure distribution measuring apparatus according to the present invention can measure not only the pressure detection function but also the pressure distribution on the pressure-sensitive sensor sheet plane and its change with time.

The basic structure of the fiber structure constituting the pressure-sensitive sensor sheet in the present invention is composed of an upper surface portion, a lower surface portion, and a connecting portion that maintains a predetermined distance between the upper surface portion and the lower surface portion. A plurality of conductive yarns are arranged on the lower surface portion so as to cross each other. And the pressure sensitive sensor sheet is in a contact state between the conductive yarn on the upper surface portion and the conductive yarn on the lower surface portion when the connecting portion is compressed by pressing, and the elasticity of the fiber material constituting the connecting portion itself after pressure removal, It is characterized in that the conductive thread on the upper surface part and the conductive thread on the lower surface part are separated from each other when the gap is restored to the state before pressing due to the physical properties such as rigidity and the compression recovery characteristic of the entire structure including the connecting part. To do.

The fiber structure constituting the pressure-sensitive sensor sheet includes a woven fabric, a knitted fabric, and the like. Specific examples include a double-tissue woven fabric typified by airy weaving and the like. Multi-layered structure fabrics such as tissue fabrics, velvet fabrics, three-dimensional knitted fabrics such as double circular knitting and double raschel, etc. When the gap is added, the gap between the upper surface portion and the lower surface portion, which is held at a predetermined interval by the connecting portion, is compressed and contacted with the conductive yarn, and after the gradual pressure, the gap is recovered and the conductive yarn is separated. The structure is not limited to this.

Specific fiber materials constituting the upper surface and the lower surface are polyester fibers such as polyethylene terephthalate and PTT (polytrimethylene terephthalate), nylon (polyamide fiber), aramid (aromatic polyamide fiber), polypropylene and polyethylene, etc. Examples thereof include polyolefin fibers, synthetic fibers such as acrylic, chemical fibers such as rayon and acetate, and natural fibers such as cotton, wool, and silk, but the fiber material is not limited to this as long as it is not conductive. Even if two or more kinds of materials are combined instead of a single material, the material is not limited to this as long as it is a fiber material that does not have conductivity.

Specific examples of conductive yarns having conductivity that are disposed or included in the upper surface portion and the lower surface portion include metal fibers such as copper, carbon fibers, and the like, but the conductive fiber material is not limited thereto. Absent. Conductive yarns that are not a single material but are composed of two or more materials, such as polyester fibers such as polyethylene terephthalate and PTT (polytrimethylene terephthalate), nylon (polyamide fibers), polypropylene and polyethylene, etc. Thread, polyester or nylon, which has a conductive function by coating the fiber surface with a metal such as silver, copper, or nickel on a non-conductive fiber such as polyolefin fiber or aramid (aromatic polyamide fiber). (Polyamide fibers), polyolefin fibers such as polypropylene and polyethylene, and non-conductive fibers such as aramid (aromatic polyamide fibers) are combined with conductive materials such as metal fibers by means of twisting, spinning, etc. Conductivity after composite (processing), such as yarn with conductivity function The present invention is not limited to this if the yarn.

  As the connecting portion for connecting the upper surface portion and the lower surface portion, it may be woven or knitted simultaneously with the upper surface portion and the lower surface portion like the multilayer structure woven fabric and the three-dimensional structure knitted fabric, or the upper surface portion configured in a sheet shape and You may make it connect by sewing a connection thread | yarn to a lower surface part. The fiber material used for the connection part is polyester fiber such as polyethylene terephthalate or PTT (polytrimethylene terephthalate), nylon (polyamide fiber), aramid (aromatic polyamide fiber), polyolefin fiber such as polypropylene or polyethylene, acrylic, etc. Synthetic fibers, chemical fibers such as rayon and acetate, and natural fibers such as cotton, wool, and silk, but are not limited thereto as long as they are non-conductive fiber materials. Even if two or more kinds of materials are combined instead of a single material, the material is not limited to this as long as it is a fiber material that does not have conductivity. In addition, the thread used for the connecting part depends on the structure of the structure and the pressure range to be detected, so it is difficult to refer to it in general, but it has good strength and rigidity that the air gap can keep and high resilience, It is preferable that the elongation recovery rate at 20% elongation is 40% or more or the expansion / contraction restoration rate is 15% or more.

As a specific example of the conductive yarns arranged on the upper surface portion and the lower surface portion in the present invention, the conductive yarns are arranged on the upper surface portion in parallel at regular intervals, and the lower surface portion is constant in the direction orthogonal to the upper surface conductive yarn. The matrix structure is composed of conductive yarns arranged at intervals. The purpose of pressure distribution measurement and pressure aging measurement is that the conductive yarns arranged on the upper surface and the conductive yarns arranged on the lower surface are in contact by pressing. However, the arrangement is not limited to this as long as the arrangement can be achieved.

Specific examples of controlling the pressure range to be detected include a method of changing the fiber material of the fiber structure constituting the multilayer structure knitted fabric, a method of changing the woven structure and knitting structure of the multilayer structure knitted fabric, and the warp and weft of the multilayer structure fabric. Examples thereof include a method for changing the density and the knitting density of the multilayer structure knitted fabric, but the method is not limited to this as long as the method can control the compression and compression recovery characteristics of the space in which the conductive yarn is arranged.

  As a specific example of measuring the pressure distribution, voltage is applied sequentially to the conductive yarn installed or contained in the upper surface of the pressure-sensitive sensor sheet, and the voltage or current of the conductive yarn installed or contained in the lower surface is sequentially detected. System to detect pressure electrically, etc., but it is possible to detect the pressure distribution by electrically connecting the conductive yarns arranged on both sides of the pressure sensitive sensor sheet and measuring the conductive state If so, it is not limited to this.

Hereinafter, an embodiment of the present invention will be described with reference to FIGS.

FIG. 1 shows an example in which a plain fabric weaving heavy tissue woven fabric of the organization chart of FIG. 2 is used as the fiber structure of the multilayer structure sheet. Polyester false twisted yarn (110dtex) for warp yarn, nylon monofilament (156dtex) for weft yarn, copper metal fiber (Φ = 0.1mm) wrapped in spiral around polyurethane fiber (470dtex) for conductive yarn Using the processed yarn, we use a rapier loom to weave the pressure-sensitive sensor sheet.

Ten conductive yarns 3 are arranged in stripes on the upper surface 1 at intervals of 8 mm, and ten conductive yarns 4 are arranged on the lower surface 2 at intervals of 8 mm in the direction perpendicular to the conductive yarns 3 on the upper surface 1. Weaving pressure sensitive sensor sheet.

FIG. 3 is an enlarged cross-sectional view of the double tissue fabric of FIG. 1. The upper surface portion 5 and the lower surface portion 6 of the double tissue fabric are connected by the connecting portion 10, and the conductive yarn constituting the upper surface portion 5 and the lower surface portion 6. The warp yarns other than are arranged at the connecting portion 10 so that the parts arranged from the upper surface 5 to the lower surface 6 (or from the lower surface 6 to the upper surface 5) are interchanged. That is, since the warp yarns constituting the pressure-sensitive sensor sheet of the present embodiment are restrained by the connecting portion 10, a space 7 having a constant interval is formed between the upper surface portion 5 and the lower surface portion 6 due to the rigidity of the yarn material. Playing a role.

By applying pressure to the upper surface portion 5, the space between the surface 5 and the surface 6 is compressed, and the conductive yarns 8 and 9 come into contact with each other. As a result, the electrical resistance between the conductive yarns 8 and 9 changes, and the pressure is detected.

The pressure applied to the upper surface 5 is measured with a 14 mm diameter crimping terminal using RETEP CAPACITY (Type B, 50N, 200N) manufactured by AIKOU ENGINEERING, and the resistance value at each pressure is a digital multimeter manufactured by ADVANTEST (R6552) Conductance was obtained by measurement at This result is shown in FIG. 4 as the pressure-sensitive sensor sheet characteristics. It can be seen that this is a pressure-sensitive sensor sheet in which the conductance starts to change at a pressure of 1.3 kPa, and the conductance changes abruptly around the pressure of 2.0 kPa.

An ADVANTEST digital multimeter (R6552) is installed between the fibers of the conductive yarns 3 and 4, and a mode in which an electronic sound is generated when energized is selected. In this case, an electronic sound was generated when a pressure of 1.3 kPa or higher was applied to the pressure sensitive sensor sheet. By constructing a similar system and arbitrarily setting the current or voltage threshold, it becomes an ON / OFF pressure-sensitive sensor sheet. As a specific example, if a conductance of 0.2 (1 / Ω) is selected as a threshold value, a pressure-sensitive sensor sheet that generates sound when pressurized to 0.2 kPa or higher is obtained.

Each of the ten conductive yarns in FIG. 1 is assigned an identification number A to J, and each of the ten conductive yarns 4 is assigned an identification number 1 to 10 to create a system that can measure the conductive state between the conductive yarns. . Specifically, the selector of FIG. 1 sequentially selects the conductive yarns A to J, and outputs a voltage signal from the personal computer to each conductive yarn. On the other hand, the voltage detected from each of the conductive yarns 1 to 10 is sequentially scanned and input to the personal computer. When a voltage of 0.7 V or higher is confirmed between A to J of the selected conductive yarn 3 and the conductive yarns 1 to 10, it is detected that pressure is applied to the matrix, and the pressure state is displayed on the screen of the personal computer. This is a program to be displayed.

Fig. 5 shows an example in which a pressure sample (weight 100gf, bottom area 3.1cm ² ) with a pressure of 2KPa or more is placed on this pressure-sensitive sensor sheet, pressure is applied, and the pressure distribution state is displayed on the personal computer screen. is there.

The black portion in FIG. 5 shows a portion pressed by the pressurized sample, and the pressure is detected at the position where the conductive yarns C, D and 3 and 4 intersect, and the pressurized sample is a pressure-sensitive sensor. It shows that the conductive yarns C, D and 3, 4 of the sheet are in an intersecting position.

FIG. 6 shows an example in which a change in pressure distribution is detected when this pressurized sample is moved in the direction from the conductive yarn 1 to 10. The location pressed by the pressurized sample starts from the intersection of C, D and 3, 4 (Fig. 6-A), and then sequentially intersects D, E and 4, 5 (Fig. 6-B), E, F and 6, 7 intersection (Fig. 6-C), D, E and 7, 8 intersection (Fig. 6-D), and finally E, F and 9, 10 intersection (Fig. 6- It can be seen that E) has been reached.

From this figure, it can be seen that the movement of the pressure body can be detected on the pressure-sensitive sensor sheet with time.

As Example 2, FIG. 7 shows a specific example in which the pressure range detected by the pressure-sensitive sensor sheet can be controlled by changing the fiber material constituting the multilayer structure fiber structure.

The pressure-sensitive sensor sheet of Example 2 is a multi-layer structure fiber structure having the same woven structure as the double-tissue fabric shown in FIG. 2, but the warp and weft yarns constituting the upper surface portion 5 and the lower surface portion 6 are polyester temporary. Twisted yarn (110 dtex) was used. Conductive yarns 8 and 9 arranged on the upper surface portion 5 and the lower surface portion 6 are a cover in which copper metal fibers (Φ = 0.1 mm) are spirally wound around the conductive yarns in the same manner as in the first embodiment. Ring processed yarn is used for conductive yarn.

Similarly to Example 1, FIG. 7 shows the results of applying pressure to the upper surface portion 5 and measuring the applied pressure and conductance. The pressure at which the conductance is 0.2 (1 / Ω) or higher is 15 kPa, and a pressure-sensitive sensor sheet with a different pressure detection range is formed from FIG. 4 (the pressure at which the conductance is 0.2 (1 / Ω) or higher is 2 kPa). Yes.

An ADVANTEST digital multimeter (R6552) is installed between the fibers of the conductive yarns 3 and 4, and a mode in which an electronic sound is generated when energized is selected. In this case, generation of electronic sound was observed at 10 kPa or more. In the case of Example 1, an electronic sound is generated when a pressure of 1.3 kPa or more is applied. From this, in Example 2, Example 1 is obtained by changing the fiber material constituting the multilayer structure fiber structure. It can be seen that a pressure-sensitive sensor sheet having a different pressure range is formed.

In addition, the pressure amount and the conductance are in a proportional relationship in the range of 10 to 30 kPa, and a pressure-sensitive sensor sheet that can not only detect the pressure but also estimate the pressure value by detecting a change in the electric resistance between them is possible.

Since the present invention is a pressure-sensitive sensor sheet in which a pressure sensor and a sheet are integrated, not only is easy to handle, but also has flexibility and stretchability, so that it is bonded along the curved surface of a flexible solid object. Excellent workability and workability. It can measure not only pressure sensors but also temporal changes in pressure distribution on a flat surface, and is expected to be applied in various industrial fields such as the textile industry, construction industry, and automobile industry.

Some specific uses are described below. Large-scale systems are expected to be used in various applications and products, such as sensors that detect human movement by being incorporated in flooring, switches as wall coverings, and seating status monitoring systems such as halls. As a small system, it is expected to be used and commercialized to detect and measure temporal changes in pressure distribution that occurs in switches and outerwear and shoes when a person is exercising in a car.

It is a block diagram of a pressure-sensitive sensor sheet. It is a textile organization figure (flat air circulation double organization) of a pressure-sensitive sensor sheet. It is a cross-sectional enlarged view of a pressure-sensitive sensor sheet. It is a graph which shows the characteristic of a pressure-sensitive sensor sheet. It is explanatory drawing which shows the example of a display regarding the pressure measurement using a pressure-sensitive sensor sheet. It is explanatory drawing which shows the example of a display regarding the time change of the pressure measurement using a pressure-sensitive sensor sheet. It is a graph which shows the characteristic of the pressure-sensitive sensor sheet regarding another Example.

Claims (6)

An upper surface portion in which a plurality of conductive yarns are arranged at a predetermined interval in the surface direction; a lower surface portion in which the plurality of conductive yarns are arranged in a direction intersecting the conductive yarns of the upper surface portion at a predetermined interval in the surface direction; A pressure-sensitive device comprising a connecting portion that keeps a predetermined distance between the lower surface portions, and when the connecting portion is compressed by pressing, the conductive yarn on the upper surface portion and the conductive yarn on the lower surface portion are in contact with each other. Sensor sheet. The pressure-sensitive sensor sheet according to claim 1, wherein the upper surface portion, the lower surface portion, and the connecting portion are made of a fiber structure. The pressure-sensitive sensor sheet according to claim 2, wherein the fiber structure is composed of a woven fabric. The pressure-sensitive sensor sheet according to claim 2, wherein the fiber structure is composed of a knitted fabric. The pressure-sensitive sensor sheet according to any one of claims 2 to 4, wherein the upper surface portion and the lower surface portion have a multi-layer structure. A pressure-sensitive sensor sheet according to any one of claims 1 to 5, electrically connected to each conductive yarn on the upper surface portion and electrically connected to each conductive yarn on the lower surface portion, and each conductive yarn on the upper surface portion; A pressure distribution measuring apparatus comprising: a measuring unit that measures a conductive state between each conductive yarn on the lower surface portion.