JP2006184098A - Pressure-sensitive sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an accurate pressure-sensitive sensor having a wide dynamic range of a detection pressure and excellent detection sensitivity. <P>SOLUTION: A plurality of circular recessed parts 1a are arrayed and formed in the matrix direction on a substrate 1, and a pair of spiral electrodes 2, 3 are provided respectively on the bottom surface of each circular recessed part 1a. Three circular recessed parts 1a aligned in the row direction are treated as one set, and the upper side of the three circular recessed parts 1a is covered by oblong conductive pressure-sensitive rubber 4 relative to each set, and upper and lower ends 4a, 4b of the conductive pressure-sensitive rubber 4 are bonded onto the substrate 1 by an adhesive 5, to thereby support the conductive pressure-sensitive rubber 4 on the substrate 1. Hereby, this pressure-sensitive sensor 10, having the circular recessed part 1a, the pair of spiral electrodes 2, 3, and the conductive pressure-sensitive rubber 4 relative to each circular recessed part 1a, is formed. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a pressure-sensitive sensor using a conductive pressure-sensitive member whose resistance value changes due to the action of an external force.

  As this type of conventional apparatus, for example, there are those described in Patent Documents 1 and 2. In the pressure sensor of Patent Document 1, strip-shaped conductive pressure-sensitive rubbers are arranged on a flexible electrode plate at regular intervals, and the conductive pressure-sensitive rubber and the electrode plate are sandwiched between a pair of adhesive tapes. The pressure sensor can be attached to the curved flexible body, and the change in conductivity of the conductive pressure-sensitive rubber due to bending is prevented.

Moreover, in the apparatus of Patent Document 2, a pair of flexible substrates is attached to the front and back of the pressure-sensitive elastomer sheet, and the pressure of the XY coordinate in the pressure-sensitive elastomer sheet is detected through the electrodes of each flexible substrate.
JP-A-4-38432 JP-A-6-281516

  However, when each conductive pressure-sensitive rubber and the electrode plate are sandwiched between a pair of adhesive tapes as in Patent Document 1, a compressive force acts on each conductive pressure-sensitive rubber as a result of sandwiching each adhesive tape, and each conductive pressure-sensitive rubber is The entire pressure-sensitive rubber is distorted, and the resistance value of each conductive pressure-sensitive rubber has already changed while in the initial state (no-load state). The dynamic range (detection range) of the detected pressure has decreased.

  Also, as the adhesive of each adhesive tape hardens, the hardness of the pressure sensor itself increases, so even if pressure is applied, the conductive pressure-sensitive rubber becomes difficult to distort and the detection sensitivity of the pressure sensor decreases. did.

  On the other hand, even when a pair of flexible substrates is attached to the front and back of the pressure-sensitive elastomer sheet as in Patent Document 2, the hardness of the pressure-sensitive elastomer sheet increases when the adhesive used to attach each flexible substrate is cured. As a result, even when pressure is applied, the pressure-sensitive elastomer sheet becomes difficult to be distorted, and its detection sensitivity is lowered.

  In addition, when there is an electrode of a flexible substrate in the vicinity of the cured adhesive, the detection sensitivity of the pressure sensitive elastomer sheet in the vicinity of the cured adhesive is reduced, so the detection accuracy at the position of this electrode is reduced, This caused variations in detection sensitivity.

  Therefore, the present invention has been made in view of the above-described conventional problems, and an object thereof is to provide an accurate pressure-sensitive sensor having a wide detection pressure dynamic range, good detection sensitivity, and the like.

  In order to solve the above-described problems, the present invention includes a conductive pressure-sensitive member whose resistance value changes due to the action of an external force, and a support that supports the conductive pressure-sensitive member. In a pressure-sensitive sensor that detects a resistance value of a member, a portion of the conductive pressure-sensitive member that is separated from a portion of the conductive pressure-sensitive member on which an external force acts is connected to the support body to support the conductive pressure-sensitive member. The portion of the conductive pressure-sensitive member connected to the support is a portion where the character does not substantially change even if an external force acts on the conductive pressure-sensitive member.

  In the present invention, the character of the portion of the conductive pressure-sensitive member is the resistance value of the portion of the conductive pressure-sensitive member.

  Furthermore, in the present invention, the character of the portion of the conductive pressure-sensitive member is the thickness of the portion of the conductive pressure-sensitive member.

  In the present invention, the conductive pressure-sensitive member is a conductive pressure-sensitive rubber.

  Furthermore, in the present invention, the conductive pressure sensitive member is a conductive gel.

  In the present invention, the conductive pressure-sensitive member is a gel or elastomer mixed with carbon microcoils.

  Furthermore, in the present invention, the conductive pressure-sensitive member is a member enclosing pressure-sensitive conductive ink.

  Further, in the present invention, even if an external force acts on the conductive pressure-sensitive member, the portion of the conductive pressure-sensitive member whose trait does not substantially change is an end of the conductive pressure-sensitive member, It is connected to the support by an adhesive.

  According to the pressure-sensitive sensor of the present invention, the conductive pressure-sensitive member portion that is separated from the portion of the conductive pressure-sensitive member on which an external force acts is connected to the support, and the conductive pressure-sensitive member is supported. The portion of the conductive pressure-sensitive member connected to the body is a portion where the character does not substantially change even when an external force is applied to the conductive pressure-sensitive member. Therefore, the portion of the conductive pressure-sensitive member connected to the support does not affect the portion of the conductive pressure-sensitive member that receives external force. Therefore, in the initial state (no load state), the conductive pressure-sensitive member that receives external force is not affected. The portion of the pressure member does not distort, the resistance value of the portion does not change, the dynamic range of the detection pressure is wide, the detection sensitivity is kept good, and the variation in detection results can be suppressed.

  The character of the portion of the conductive pressure-sensitive member is the resistance value of the portion of the conductive pressure-sensitive member. Alternatively, the thickness of the portion corresponding to the resistance value of the portion.

  Examples of the conductive pressure-sensitive member include a conductive pressure-sensitive rubber, a conductive gel, a material in which a carbon microcoil is mixed in a gel or an elastomer, and a member in which pressure-sensitive conductive ink is sealed.

  Moreover, the part of the electroconductive pressure sensitive member in which a character does not change substantially is an edge part of an electroconductive pressure sensitive member, for example, Comprising: It connects to a support body with an adhesive agent. When the end of the conductive pressure-sensitive member is connected to the support with an adhesive in this way, the end, that is, the portion of the conductive pressure-sensitive member connected to the support, is the location of the conductive pressure-sensitive member on which an external force acts. Separate from.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a plan view showing an embodiment of the present invention as seen through from above. In this embodiment, a plurality of circular recesses 1a are arranged in a matrix direction on the substrate 1, and a pair of spiral electrodes 2 and 3 are provided on the bottom surface of each circular recess 1a. Then, three circular recesses 1a arranged in the row direction are taken as one set, and for each set, the upper side of the three circular recesses 1a is covered with a strip-shaped conductive pressure-sensitive rubber 4, and the upper and lower ends 4a of the conductive pressure-sensitive rubber 4 4b is bonded to the substrate 1 with an adhesive 5, and the conductive pressure-sensitive rubber 4 is supported on the substrate 1. Thereby, the pressure sensor 10 which has a pair of spiral electrode 2, 3 and the electroconductive pressure-sensitive rubber 4 for every circular recessed part 1a is formed.

  Further, for each row, the spiral electrodes 2 of the three pressure sensitive sensors 10 are connected in common by the row signal line 6, and for each column, the spiral electrodes 3 of the three pressure sensitive sensors 10 are connected by the column signal line 7. Common connection.

  The spiral electrodes 2 and 3 are arranged in parallel to each other while being spiral.

  The conductive pressure-sensitive rubber 4 is made of, for example, metal particles, carbon black, graphite particles, or the like in a synthetic rubber such as silicone rubber, ethylene propylene rubber, or chloroprene rubber, or a non-conductive elastomer such as a thermoplastic elastomer exhibiting rubber elasticity. Conductive particles are mixed and dispersed. When the conductive pressure-sensitive rubber 4 is compressed and deformed by an external force and is distorted, each conductive particle approaches or comes into contact with the strained portion, and the resistance value decreases. Therefore, it is possible to know how much external force has acted on the conductive pressure-sensitive rubber 4 by detecting the decrease variation of the resistance value of the conductive pressure-sensitive rubber 4.

  FIG. 2 is a cross-sectional view showing a single pressure sensor 10. As apparent from FIG. 2, in the initial state (no-load state), the conductive pressure-sensitive rubber 4 covering the upper side of the circular recess 1a has a flat plate shape. Therefore, the conductive pressure-sensitive rubber 4 is formed on the bottom surface of the circular recess 1a. It is separated from each spiral electrode 2, 3.

  Further, for example, as shown in FIG. 3, when the object J comes into pressure contact with the pressure sensor 10 and an external force is applied to the pressure sensor 10, the conductive pressure sensitive rubber 4 is bent downward at the position of the pressure sensor 10 to be circular. It contacts the spiral electrodes 2 and 3 on the bottom surface of the recess 1a.

  Then, the conductive pressure-sensitive rubber 4 is compressed and distorted according to the external force applied to the pressure-sensitive rubber sensor 10, and the resistance value of the conductive pressure-sensitive rubber 4 is decreased according to the strain amount of the conductive pressure-sensitive rubber 4. Accordingly, by detecting the decrease fluctuation of the resistance value of the conductive pressure-sensitive rubber 4 at the location of the pressure-sensitive sensor 10, it is possible to know how much external force has been applied to this location.

  Since the upper and lower ends 4a, 4b of the conductive pressure sensitive rubber 4 are bonded to the substrate 1 with the adhesive 5, the flat shape of the conductive pressure sensitive rubber 4 can be maintained well, and the conductive pressure sensitive rubber is used. 4 and the spiral electrodes 2 and 3 are in close contact with each other.

  The resistance value of the conductive pressure-sensitive rubber 4 at the location of the pressure-sensitive sensor 10 is detected between the spiral electrodes 2 and 3 of the pressure-sensitive sensor 10 through the row signal line 6 and the column signal line 7. For example, a fixed resistor is connected to one of the spiral electrodes 2 and 3 (not shown), each column signal line 7 is sequentially selected, and each time the column signal line 7 is selected, each row signal line 6 are sequentially selected, and the signal voltage (voltage drop) generated at the fixed resistor, the spiral electrode 2 of the selected row signal line 6 and the spiral electrode 3 of the selected column signal line 7 is detected at this time. Based on the voltage, the resistance value of the conductive pressure-sensitive rubber 4 at the location of the pressure-sensitive rubber 4 is detected. The resistance value of the conductive pressure sensitive rubber 4 in the initial state as shown in FIG. 2 is detected, and the resistance value of the conductive pressure sensitive rubber 4 when an external force is applied to the pressure sensitive sensor 10 as shown in FIG. 3 is detected. If the difference between the two resistance values is obtained, the decrease in the resistance value of the conductive pressure-sensitive rubber 4 can be detected, and the pressure-sensitive rubber sensor 10 is acted on based on the decrease in the resistance value. External force can be calculated.

  Such detection of the external force is performed for each pressure-sensitive sensor 10. Therefore, in the present embodiment, it is possible to detect how much external force is applied to which of the pressure sensors 10.

  By the way, in the pressure-sensitive sensor 10, as shown in FIG. 2, the diameter of the circular recess 1a is 3 mm, and the height from the surface of each spiral electrode 2, 3 to the upper edge of the circular recess 1a is 0.03mm. The width of each spiral electrode 2 and 3 is 0.2 mm, the distance between each spiral electrode 2 and 3 is 0.2 mm, and the thickness of the conductive pressure-sensitive rubber 4 is 0.5 mm.

  The distance X from the upper end 4a of the conductive pressure-sensitive rubber 4 fixed to the substrate 1 by the adhesive 5 to the portion Pa of the spiral electrodes 2 and 3 of the circular recess 1a arranged on the uppermost side is 0.5 mm or more. Similarly, the distance from the lower end 4b of the conductive pressure-sensitive rubber 4 to the spiral electrodes 2 and 3 of the circular recess 1a arranged at the lowermost side is also 0.5 mm or more. These distances can be easily set because the upper and lower ends 4 a and 4 b of the distance conductive pressure-sensitive rubber 4 are bonded to the substrate 1 with the adhesive 5. As a result, the upper and lower ends 4 a and 4 b of the conductive pressure-sensitive rubber 4 are sufficiently separated from the circular recess 1 a of the nearest pressure-sensitive sensor 10 and fixed.

  Here, when an external force acts on the conductive pressure-sensitive rubber 4, not only the portion where the external force is applied, but also the portion of the conductive pressure-sensitive rubber 4 that is separated from this portion is distorted. When it becomes smaller and sufficiently separated, the initial state (no load state) is maintained with almost no distortion, and the resistance value and thickness do not change. Since the upper and lower ends 4a, 4b of the conductive pressure sensitive rubber 4 are sufficiently separated and fixed from the circular concave portion 1a of the nearest pressure sensitive sensor 10, an external force acts on the portion of the conductive pressure sensitive rubber 4 of the circular concave portion 1a. Even so, the initial state of the upper and lower ends 4a and 4b is maintained, and the resistance values and thicknesses of the upper and lower ends 4a and 4b are maintained. On the contrary, since the upper and lower ends 4a and 4b always maintain the initial state, even if the upper and lower ends 4a and 4b are fixed by the adhesive 5, the portions of the conductive pressure-sensitive rubber 4 which are compressed and distorted by the action of an external force (circular recesses 1a). ). Therefore, in the initial state, although the upper and lower ends 4 a and 4 b are fixed by the adhesive 5, the resistance value of the conductive pressure-sensitive rubber 4 does not change, and the detected pressure of the pressure-sensitive sensor 10 does not change. A wide dynamic range, good detection sensitivity can be maintained, and variations in detection results can be suppressed.

  If the conductive pressure-sensitive rubber 4 is fixed with an adhesive in the vicinity of the circular recess 1a, the portion of the conductive pressure-sensitive rubber 4 fixed with the adhesive is cured, and the cured portion is compressed by the action of external force. This affects the location (circular recess 1a) of the conductive pressure sensitive rubber 4 which is distorted. This is because the portion of the conductive pressure-sensitive rubber 4 cured by the adhesive is not easily distorted, and the portion of the conductive pressure-sensitive rubber 4 in the vicinity thereof is also hardly distorted, and the detection sensitivity by the conductive pressure-sensitive rubber 4 is reduced. This is because the detection error of the external force at the location becomes large.

  In addition, this invention is not limited to the said embodiment, It can deform | transform variously. For example, instead of the conductive pressure-sensitive rubber, a conductive gel, or a material in which a carbon microcoil is mixed in gel or elastomer, and a member in which pressure-sensitive conductive ink is sealed can be applied.

  The pressure-sensitive sensor of the present invention can be used for a pressure distribution measuring device or a tactile sensor mounted on a robot hand.

It is one Embodiment of this invention, and is a top view which sees through and shows several pressure-sensitive sensors from upper direction. It is sectional drawing which shows a single pressure sensor. It is sectional drawing which shows the operation state of the pressure sensor of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Substrate 1a Circular recessed part 2, 3 Spiral electrode 4 Conductive pressure sensitive rubber 5 Adhesive 6 row signal line 7 column signal line 10 Pressure sensor

Claims (8)

In a pressure-sensitive sensor that includes a conductive pressure-sensitive member whose resistance value changes due to the action of an external force, and a support that supports the conductive pressure-sensitive member, and detects the resistance value of the conductive member for detecting external force.
A portion of the conductive pressure sensitive member that is spaced apart from the location of the conductive pressure sensitive member on which an external force acts is connected to the support, and the conductive pressure sensitive member is supported.
The portion of the conductive pressure-sensitive member connected to the support is a portion where the character does not substantially change even when an external force acts on the conductive pressure-sensitive member.   2. The pressure-sensitive sensor according to claim 1, wherein the character of the conductive pressure-sensitive member portion is a resistance value of the conductive pressure-sensitive member portion.   The pressure sensor according to claim 1, wherein the character of the portion of the conductive pressure sensitive member is a thickness of the portion of the conductive pressure sensitive member.   The pressure-sensitive sensor according to claim 1, wherein the conductive pressure-sensitive member is a conductive pressure-sensitive rubber.   The pressure-sensitive sensor according to claim 1, wherein the conductive pressure-sensitive member is a conductive gel.   The pressure-sensitive sensor according to claim 1, wherein the conductive pressure-sensitive member is a gel or elastomer mixed with a carbon microcoil.   The pressure-sensitive sensor according to claim 1, wherein the conductive pressure-sensitive member is a member enclosing pressure-sensitive conductive ink. The portion of the conductive pressure-sensitive member whose trait does not substantially change even when an external force is applied to the conductive pressure-sensitive member is an end of the conductive pressure-sensitive member, and is attached to the support by an adhesive. The pressure-sensitive sensor according to claim 1, wherein the pressure-sensitive sensor is connected.

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