JP2008209384A - Sensor sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sensor sheet having a simple configuration and capable of detecting the components in a plurality of different directions of an externally applied force. <P>SOLUTION: In a sensor sheet, a plurality of first electrodes 11 each covered with pressure sensitive resistive members 11 and a plurality of second electrodes 21 each covered with pressure sensitive resistive members are arranged orthogonally to each other in plan view. A core member 40 formed of a hard material is disposed to extend onto the four detection regions in which the plurality of the first electrodes 11 and the plurality of the second electrodes 21 overlap each other in plan view. The X-axial component Fx, the Y-axial component Fy, and the Z-axial component Fz are detected, based on changes in resistance value of contact resistances R1, R2, R3, and R4 corresponding to the detection regions having one core member 40 disposed to extend onto them. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a sensor sheet that can measure the distribution of externally applied force.

  As the sensor sheet, a PET film in which the pressure-sensitive resistance ink is printed in a strip shape along the vertical direction, and a PET film in which the pressure-sensitive resistance ink is printed in a strip shape along the horizontal direction (a direction perpendicular to the vertical direction), There is known one in which pressure-sensitive resistance inks printed on each of them are bonded so as to intersect (see Patent Documents 1 and 2). In such a sensor sheet, when a force is applied from the outside, the contact resistance between the two PET films corresponding to the applied portion changes. Accordingly, the distribution of the force (pressure) applied from the outside can be measured by detecting the change in the magnitude of the contact resistance along the lines of a large number of pressure-sensitive resistance inks.

  However, the sensor sheet described above can only detect a component corresponding to a direction perpendicular to the sheet, out of a force applied from the outside, and cannot detect a component corresponding to the other direction. That is, even when a force in an oblique direction (a direction other than the vertical direction) is applied to the sensor sheet, it is the same as when a force having a magnitude of a direction component perpendicular to the sheet of the force in the oblique direction is applied. Only the distribution of force can be obtained. Therefore, detailed analysis of the distribution of force applied from the outside cannot be performed.

Therefore, the applicant of the present application has proposed a sensor sheet that can detect components corresponding to a plurality of directions different from each other in force applied from the outside (see Patent Document 3). Such a sensor sheet has a large number of sensor cells arranged in a matrix, and each sensor cell has a plurality of electrodes corresponding to the X-axis direction, the Y-axis direction, and the Z-axis direction. When a force is applied from the outside, the contact resistance value of the pressure-sensitive resistance ink arranged between the electrodes corresponding to each direction changes, so by detecting this change in resistance value, Components of the applied force corresponding to the X-axis direction, the Y-axis direction, and the Z-axis direction can be detected.
U.S. Pat. No. 4,734,034 US Pat. No. 4,856,993 JP 2004-117042 A

  However, although the sensor sheet can detect components corresponding to the X-axis direction, the Y-axis direction, and the Z-axis direction of the force applied from the outside, the following various problems occur. . First, since each sensor cell has a large number of electrodes corresponding to a plurality of different directions, it is difficult to reduce the size of the sensor sheet, and in particular, when a large number of sensor cells are arranged close to each other, a large number of electrodes It is very difficult to pull out the lead wire from all of the above. Further, the configuration of each sensor cell is complicated, and the efficiency in increasing the density of sensor cells is very poor. Furthermore, when converting the pressure detected by each sensor cell into a voltage proportional to the magnitude, an R / V conversion circuit that converts the resistance to voltage at a ratio of 1: 1 with respect to all the contact resistances is required. The conversion circuit becomes large.

  Such a problem is based not only on the sensor sheet in which the force is detected based on the change in the contact resistance value of the pressure-sensitive resistance ink between the electrodes, but also on the change in the capacitance value of the capacitive element between the electrodes. It also occurs in sensor sheets where force is detected.

  Accordingly, an object of the present invention is to provide a sensor sheet that can detect components corresponding to a plurality of different directions of forces applied from the outside with a simple configuration.

Means for Solving the Problems and Effects of the Invention

  The sensor sheet of the present invention has a plurality of first electrodes that are band-shaped and spaced apart from each other, and are band-shaped and spaced from each other and are disposed so as to intersect with the plurality of first electrodes in plan view. A plurality of second electrodes that are displaceable in a direction approaching the first electrode in accordance with a force applied from outside, and at least a plane between the plurality of first electrodes and the plurality of second electrodes. And a plurality of pressure-sensitive resistors disposed in a detection region where the first electrode and the second electrode overlap each other, and disposed on a side opposite to the plurality of first electrodes with respect to the plurality of second electrodes. And a core member formed of a hard material disposed across a plurality of the detection regions in plan view, and corresponding to each of the plurality of detection regions of the first electrode and the second electrode Contact resistance value between Is characterized by recognizing the component corresponding to a plurality of directions different from each other externally applied force based on the change.

  The sensor sheet of the present invention has a plurality of first electrodes that are band-shaped and spaced apart from each other, and are band-shaped and spaced from each other and are disposed so as to intersect with the plurality of first electrodes in plan view. A plurality of second electrodes that are displaceable in a direction approaching the first electrode in accordance with a force applied from the outside, and on the opposite side of the plurality of first electrodes with respect to the plurality of second electrodes. And a core member formed of a hard material disposed across a plurality of detection regions in which the first electrode and the second electrode overlap in plan view, and the plurality of first electrodes, The plurality of second electrodes are insulated from each other and applied from the outside based on a change in capacitance value between portions corresponding to each of the plurality of detection regions of the first electrode and the second electrode. Different force It is characterized by recognizing the corresponding components.

  According to this configuration, it is possible to detect components corresponding to a plurality of different directions of force applied from the outside only by arranging a relatively small number of first electrodes and second electrodes. Therefore, the configuration of the sensor sheet can be simplified, and the lead wire from each electrode can be easily pulled out. Therefore, it is possible to obtain a sensor sheet that can detect components corresponding to a plurality of different directions of the force applied from the outside without going through a complicated manufacturing process.

  In the sensor sheet of the present invention, the plurality of detection regions may be four detection regions arranged symmetrically with respect to each of two straight lines orthogonal in a plan view.

  According to this configuration, components corresponding to a plurality of different directions of the force applied from the outside are detected based on changes in resistance values corresponding to the four detection regions, so that an operation for detecting each component is performed. Simplified.

  In the sensor sheet of the present invention, the center position of the core member may coincide with the center positions of the four detection regions in plan view.

  According to this configuration, since the center position of the core member and the center positions of the four detection areas coincide in plan view, it is possible to accurately detect the force applied to the sensor sheet from the outside.

  In the sensor sheet of the present invention, at least a part of the end portion of the core member may be located inside all of the four detection regions in a plan view.

  According to this configuration, the second electrode moves in a direction approaching the first electrode by being pressed by the edge portion where the force applied from the outside concentrates on the lower surface of the core member, so that the force applied from the outside is detected. Sensitivity to improve.

  In the sensor sheet of the present invention, the core member may be a cylindrical member.

  According to this configuration, the core member can be similarly moved or inclined in any direction by an external force, so that it is possible to suppress the occurrence of directionality in force detection.

  In the sensor sheet of the present invention, the plurality of detection areas may be five detection areas arranged in line symmetry with respect to each of two straight lines orthogonal in a plan view.

  According to this configuration, components corresponding to a plurality of different directions of the force applied from the outside are detected based on changes in the contact resistance values corresponding to the five detection regions, so that an operation for detecting each component is performed. Is simplified.

  The sensor sheet according to claim 6, wherein a center position of the core member coincides with a center position of the five detection regions in plan view.

  According to this configuration, since the center position of the core member coincides with the center positions of the five detection regions in plan view, it is possible to accurately detect the force applied to the sensor sheet from the outside.

  In the sensor sheet of the present invention, at least a part of the end portion of the core member is located inside all of the four detection areas outside the five detection areas in plan view. Also good.

  According to this configuration, the second electrode moves in a direction approaching the first electrode by being pressed by the edge portion where the force applied from the outside concentrates on the lower surface of the core member, so that the force applied from the outside is detected. Sensitivity to improve.

  In the sensor sheet of the present invention, the core member may be a cylindrical member.

  According to this configuration, the core member can be similarly moved or inclined in any direction by an external force, so that it is possible to suppress the occurrence of directionality in force detection.

  In the sensor sheet of the present invention, the units including the plurality of detection regions and the core member may be arranged in a matrix.

  According to this configuration, since the units including the plurality of detection regions and the core member are uniformly arranged on the sensor sheet, it is possible to detect the distribution of the force applied from the outside to the sensor sheet.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a partial external perspective view of a sensor sheet according to the first embodiment of the present invention. FIG. 2 is a schematic diagram showing a schematic configuration of the sensor sheet of FIG. FIG. 3 is a diagram illustrating an arrangement of a plurality of detection regions in the sensor sheet. FIG. 4 is a schematic diagram illustrating a schematic configuration of the sensor sheet when a force is applied from the outside.

  As shown in FIGS. 1 and 2, the sensor sheet 1 includes a substrate 10 on which a plurality of strip-shaped first electrodes 11 are disposed, and a substrate on which a plurality of strip-shaped second electrodes 21 are disposed and bonded to the substrate 10. 20, a support member 30 and a plurality of columnar core members 40 disposed above the substrate 20, and a flat (uneven) cover layer 31 that receives a force applied from the outside. The plurality of first electrodes 11 formed on the upper surface of the substrate 10 are respectively covered with the pressure-sensitive resistor 12, and the plurality of second electrodes 21 formed on the lower surface of the substrate 20 are the pressure-sensitive resistors 22. Each is covered.

  Here, the plurality of first electrodes 11 are arranged on the upper surface of the substrate 10 so as to be separated from each other and insulated. Similarly, the plurality of second electrodes 21 are disposed on the lower surface of the substrate 20 so as to be separated from each other and insulated. And the board | substrate 10 and the board | substrate 20 are bonded together so that the 1st electrode 11 and the 2nd electrode 21 may oppose, and both may cross | intersect in planar view.

  In addition, as the board | substrate 10 and the board | substrate 20, it is formed with flexible materials, such as PET and a polyimide, for example. As the first electrode and the second electrode, for example, a conductive member such as silver, aluminum, copper, or carbon is used. As the pressure-sensitive resistor, for example, pressure-sensitive conductive ink or pressure-sensitive conductive rubber is used. In addition, as the support member 30 and the cover layer 31, for example, a flexible member such as silicon rubber, urethane rubber, or sponge is used. The core member 40 is formed of a material harder than the support member 30 and the cover layer 31. And the sensitivity of the sensor sheet | seat 1 can be adjusted by changing the component of the pressure sensitive resistors 12 and 22, the material of the support member 30 and the cover layer 31, hardness, thickness, etc. FIG. Further, the support member 30 and the cover layer 31 may be an integral member.

  In the sensor sheet 1, a portion where the first electrode 11 and the second electrode 21 overlap in a plan view is a detection region. The first electrode 11 is connected to one lead wire, and a common drive voltage is applied from the lead wire. On the other hand, one lead wire is connected to each of the second electrodes 21 and is connected to the input terminal of the OP amplifier. Therefore, a plurality of detection regions arranged on one first electrode 11 are common electrodes on the drive electrode side, and the second electrodes 21 corresponding to the detection regions are connected to independent OP amplifiers. A contact resistance value between portions corresponding to each of the plurality of detection regions of the first electrode 11 and the second electrode 21 is detected.

  Here, in the sensor sheet 1, as shown in FIG. 3, the configuration including the four detection regions D 1, D 2, D 3, D 4 and the corresponding core member 40 functions as one basic unit 2. In the sensor sheet 1, a plurality of basic units 2 are arranged in a matrix. Here, when the X axis in the direction along the first electrode 11, the Y axis in the direction along the second electrode 21, and the Z axis in the direction perpendicular to the substrate 10 are defined in plan view, four detection regions D 1, D 2, D 3 are defined. , D4 are arranged symmetrically with respect to the X and Y axes orthogonal to each other in plan view.

  Further, the core member 40 corresponding to the four detection areas D1, D2, D3, and D4 is disposed across the four detection areas D1, D2, D3, and D4 as shown in FIG. And the center position of the core member 40 corresponds with the center position of four detection area | regions D1, D2, D3, D4 in planar view. Further, at least a part of the end portion of the core member 40 is located inside all of the four detection regions D1, D2, D3, and D4 in a plan view.

  Therefore, when a force is applied to the sensor sheet 1 from the outside, the distance between the first electrode 11 and the second electrode 21 corresponding to each of the four detection areas D1, D2, D3, and D4 included in each basic unit 2 Based on changes in the resistance values of the contact resistances R1, R2, R3, and R4, components corresponding to the X-axis direction, the Y-axis direction, and the Z-axis direction of the force applied from the outside are detected.

  Hereinafter, a method for detecting components corresponding to the X-axis direction, the Y-axis direction, and the Z-axis direction of the force applied from the outside will be specifically described. Here, the resistance values of the contact resistances R1, R2, R3, and R4 corresponding to the four detection regions D1, D2, D3, and D4 are voltages V1, V2, V3, which are inversely proportional to the magnitude of external force, Suppose that it is converted to V4.

  For example, as shown in FIG. 4, when a force Fx in the X-axis positive direction, that is, a force Fx biased in the X-axis positive direction acts on the cover layer 31, a large force is applied to the portions corresponding to the detection regions D2 and D4. Depending on the magnitude of the force Fx, the resistance values of the contact resistances R2 and R4 are reduced, and the values of the voltages V2 and V4 are increased. At this time, since almost no force is applied to the portions corresponding to the detection regions D1 and D3, the resistance values of the contact resistances R1 and R3 hardly change, and the values of the voltages V1 and V3 hardly change.

  Similarly, when a force Fy in the Y-axis positive direction, that is, a force Fy biased in the Y-axis positive direction acts on the cover layer 31, a large force is applied to the portions corresponding to the detection regions D3 and D4. Accordingly, the resistance values of the contact resistances R3 and R4 are decreased, and the values of the voltages V3 and V4 are increased.

  Further, when the force Fz in the positive direction of the Z axis acts on the cover layer 31, a uniform force is applied to the portions corresponding to the detection regions D1, D2, D3, and D4, so that the contact resistance R1 depends on the magnitude of the force Fz. , R2, R3, and R4 all have small resistance values, and the voltages V1, V2, V3, and V4 all have large values.

ここで、上記の表において記号「＋」は、センサシート１に外部から力が作用していないときを基準として各電圧値が増加したことを示し、無記号は各電圧値がほとんど変化しないことを示している。 The above results are summarized as follows in relation to the X-, Y-, and Z-axis direction forces Fx, Fy, Fz and the voltages V1, V2, V3, V4.

Here, in the above table, the symbol “+” indicates that each voltage value has increased with reference to when no force is applied to the sensor sheet 1 from the outside, and no symbol indicates that each voltage value hardly changes. Is shown.

Using these characteristics, the components Fx, Fy, and Fz corresponding to the X-axis direction, the Y-axis direction, and the Z-axis direction of the force F acting on the cover layer 31 use the voltages V1, V2, V3, and V4. It is expressed by the following formula.
Fx = (V2 + V4) − (Vl + V3)
Fy = (V3 + V4) − (Vl + V2)
Fz = Vl + V2 + V3 + V4

  As described above, in the sensor sheet 1 according to the present embodiment, the resistance values of the contact resistances R1, R2, R3, and R4 corresponding to the four detection regions arranged so that one core member 40 is straddled. Using the voltages V1, V2, V3, and V4 derived based on this, the X-axis direction component Fx, the Y-axis direction component Fy, and the Z-axis direction component Fz of the force F applied from the outside to the sensor sheet 1 are detected. be able to.

  The components Fx, Fy, and Fz corresponding to the force F in the X-axis direction, the Y-axis direction, and the Z-axis direction directly detect the values of the contact resistances R1, R2, R3, and R4, and calculate the same as the above formula. It is also possible to derive by performing. In addition, the values of the voltages V1, V2, V3, and V4 are once converted into digital values using an AD converter such as a microcomputer, and then derived by performing the same calculation as the above formula. Is also possible.

  Next, a sensor sheet 101 according to a second embodiment of the present invention will be described with reference to the drawings. FIG. 5 is a diagram showing the arrangement of a plurality of detection regions in the sensor sheet according to the second embodiment of the present invention.

  The configuration of the sensor sheet 101 of the present embodiment is greatly different from the configuration of the sensor sheet 1 of the first embodiment. The sensor sheet 1 has the X axis in the direction along the first electrode 11 in the plan view, the second While the Y axis in the direction along the electrode 21 and the Z axis in the direction perpendicular to the substrate 10 are defined, in the sensor sheet 101, the X axis and the Y axis intersect the first electrode 11 and the second electrode 22. It is a defined point. Since the other configuration of the sensor sheet 101 is the same as that of the sensor sheet 1, the same reference numerals are given and detailed description thereof is omitted.

  In the sensor sheet 101, the X axis in the direction of 45 degrees clockwise from the direction along the first electrode 11 in the plan view, the Y axis in the direction of 45 degrees clockwise from the direction along the second electrode 21, and perpendicular to the substrate 10. If the Z axis in a certain direction is defined, the four detection regions D101, D102, D103, and D104 are arranged in line symmetry with respect to the X and Y axes that are orthogonal in a plan view.

  Moreover, the core member 40 corresponding to the four detection areas D101, D102, D103, and D104 is disposed across the four detection areas D101, D102, D103, and D104 as shown in FIG. And the center position of the core member 40 corresponds with the center position of four detection area | regions D101, D102, D103, D104 in planar view. Moreover, a part of edge part of the core member 40 is located inside all four detection area | regions D101, D102, D103, D104 in planar view.

  Therefore, when a force is applied to the sensor sheet 101 from the outside, the contact resistances R101, R102, between the first electrode 11 and the second electrode 21 corresponding to the four detection regions D101, D102, D103, D104, respectively. Based on changes in R103 and R104, components corresponding to the X-axis direction, the Y-axis direction, and the Z-axis direction of the force applied from the outside are detected.

Here, the contact resistances R101, R102, R103, and R104 corresponding to the four detection regions D101, D102, D103, and D104 are converted into voltages V101, V102, V103, and V104 that are inversely proportional to the magnitude of the external force. Assuming that the components Fx, Fy, Fz corresponding to the X-axis direction, the Y-axis direction, and the Z-axis direction of the force F acting on the cover layer 31 are as follows using the voltages V101, V102, V103, V104. It is expressed by a formula.
Fx = V101-V103
Fy = V102−V104
Fz = V101 + V102 + V103 + V104

  As described above, in the sensor sheet 101 of the present embodiment, as in the first embodiment, the contact resistances R101 and R102 corresponding to the four detection regions arranged so that one core member 40 is straddled. , R103, R104, and the voltage V101, V102, V103, V104 derived from the resistance value, the X-axis direction component Fx, the Y-axis direction component Fy, and Z of the force F applied to the sensor sheet 101 from the outside. Each of the axial components Fz can be detected.

  Next, a sensor sheet 201 according to a third embodiment of the present invention will be described with reference to the drawings. FIG. 6 is a diagram showing the arrangement of a plurality of detection areas in the sensor sheet according to the third embodiment of the present invention.

  The configuration of the sensor sheet 201 of the present embodiment differs greatly from the configuration of the sensor sheet 1 of the first embodiment in that the sensor sheet 1 is externally based on changes in resistance values corresponding to the four detection areas. While the component corresponding to the X-axis direction, Y-axis direction, and Z-axis direction of the applied force is detected, the sensor sheet 201 adds from the outside based on the resistance value changes corresponding to the five detection areas. The component corresponding to the X-axis direction, Y-axis direction, and Z-axis direction of the applied force is detected. Since the other configuration of the sensor sheet 201 is the same as that of the sensor sheet 1, the same reference numerals are given and detailed description is omitted.

  Here, in the sensor sheet 201, a configuration including the five detection areas D201, D202, D203, D204, D205 and the corresponding core member 240 functions as one basic unit. Here, when the X axis in the direction along the first electrode 11, the Y axis in the direction along the second electrode 21, and the Z axis in the direction perpendicular to the substrate 10 are defined in plan view, the five detection regions D201, D202, and D203 are defined. , D204, D205 are arranged symmetrically with respect to the X and Y axes orthogonal to each other in plan view. In the present embodiment, the core member 240 is arranged so as to straddle the four detection areas D200 in addition to the five detection areas D201, D202, D203, D204, and D205. The change in the resistance value of the contact resistance corresponding to is not used for force detection.

  Further, the core member 140 corresponding to the five detection areas D201, D202, D203, D204, and D205 is disposed across the five detection areas D201, D202, D203, D204, and D205 as shown in FIG. . The center position of the core member 140 coincides with the center positions of the five detection areas D201, D202, D203, D204, and D205 in plan view. In addition, a part of the end of the core member 140 is located inside all four detection areas D201, D202, D203, and D204 outside the five detection areas D201, D202, D203, D204, and D205 in plan view. positioned.

  Therefore, when a force is applied to the sensor sheet 201 from the outside, the first electrode 11 and the second electrode 21 corresponding to each of the five detection areas D201, D202, D203, D204, and D205 included in each basic unit. Based on changes in the contact resistances R201, R202, R203, R204, and R205, components corresponding to the X-axis direction, the Y-axis direction, and the Z-axis direction of the force applied from the outside are detected.

Here, the contact resistances R201, R202, R203, R204, and R205 corresponding to the five detection regions D201, D202, D203, D204, and D205 are voltages V201, V202, and V203 that are inversely proportional to the magnitude of the external force. , V204, and V205, the components Fx, Fy, and Fz corresponding to the X-axis direction, the Y-axis direction, and the Z-axis direction of the force F acting on the cover layer 31 are voltages V201, V202, V203, and V204. , V205, and is expressed by the following equation.
Fx = V201−V203
Fy = V202−V204
Fz = V205
(Or Fz = V201 + V202 + V203 + V204)
(Or Fz = V201 + V202 + V203 + V204 + V205)

  As described above, in the sensor sheet 201 of the present embodiment, as in the first embodiment, the contact resistances R201 and R202 corresponding to the five detection regions arranged so that one core member 240 is straddled. , R 203, R 204, R 205, the voltage V 201, V 202, V 203, V 204, V 205 derived from the resistance value, the force F applied to the sensor sheet 201 from the outside in the X axis direction component Fx, Y axis direction The component Fy and the Z-axis direction component Fz can be detected.

  Next, a sensor sheet 301 according to a fourth embodiment of the present invention will be described with reference to the drawings. FIG. 7 is a schematic diagram showing a schematic configuration of a sensor sheet according to the third embodiment of the present invention. FIG. 8 is a diagram illustrating an arrangement of a plurality of detection regions in the sensor sheet. FIG. 9 is a schematic diagram showing a schematic configuration of a sensor sheet when a force is applied from the outside.

  The configuration of the sensor sheet 301 of the present embodiment is greatly different from the configuration of the sensor sheet 1 of the first embodiment. In the sensor sheet 1, the resistance value of the pressure-sensitive resistor between the electrodes corresponding to the detection region is different. While the force applied from the outside based on the change is detected, the sensor sheet 301 detects the force applied from the outside based on the change in the capacitance value of the capacitive element between the electrodes corresponding to the detection region. It is a detected point. Since other configurations of the sensor sheet 301 are the same as those of the sensor sheet 1, the same reference numerals are given and detailed description thereof is omitted.

  As shown in FIG. 7, the sensor sheet 301 includes a substrate 10 on which a plurality of strip-shaped first electrodes 11 are disposed, a substrate 20 on which a plurality of strip-shaped second electrodes 21 are disposed and bonded to the substrate 10, It has a support member 30 and a plurality of cylindrical core members 40 disposed above the substrate 20 and a flat (uneven) cover layer 31 that receives a force applied from the outside. Between the plurality of first electrodes 11 formed on the upper surface of the substrate 10 and the plurality of second electrodes 21 formed on the lower surface of the substrate 20, silicon rubber, sponge, cloth are provided for all detection regions. An insulating member 312 that is a soft insulating dielectric such as a nonwoven fabric is disposed.

  In the sensor sheet 301, a portion where the first electrode 11 and the second electrode 21 overlap in plan view is a detection region. The first electrode 11 is connected to one lead wire, and a common drive voltage is applied from the lead wire. On the other hand, one lead wire is connected to each of the second electrodes 21 and is connected to a CV conversion circuit (not shown). Therefore, a plurality of detection regions arranged on one first electrode 11 become common electrodes on the drive electrode side, and the second electrodes 21 corresponding to the detection regions are connected to independent CV conversion circuits. Therefore, the capacitance value between the portions corresponding to each of the plurality of detection regions of the first electrode 11 and the second electrode 21 is detected as a voltage value by the CV conversion circuit.

  Here, in the sensor sheet 301, as shown in FIG. 8, a configuration including four detection regions D301, D302, D303, D304 and the corresponding core member 40 functions as one basic unit 302. In the sensor sheet 301, a plurality of basic units 302 are arranged in a matrix. Here, when the X axis in the direction along the first electrode 11 in the plan view, the Y axis in the direction along the second electrode 21 and the Z axis in the direction perpendicular to the substrate 10 are defined, four detection regions D301, D302, D303 are defined. , D304 are arranged symmetrically with respect to the X and Y axes orthogonal to each other in plan view.

  Therefore, when a force is applied to the sensor sheet 301 from the outside, the distance between the first electrode 11 and the second electrode 21 corresponding to each of the four detection areas D301, D302, D303, and D304 included in each basic unit 302. The components corresponding to the X-axis direction, the Y-axis direction, and the Z-axis direction of the force applied from the outside are detected based on the changes in the capacitance values of the capacitive elements C1, C2, C3, and C4.

  Hereinafter, a method for detecting components corresponding to the X-axis direction, the Y-axis direction, and the Z-axis direction of the force applied from the outside will be specifically described. Here, the capacitance values of the capacitive elements C1, C2, C3, and C4 corresponding to the four detection regions D301, D302, D303, and D304 are voltages V301, V302 proportional to the magnitude of the external force, It is assumed that the data is converted to V303 and V304.

  For example, as shown in FIG. 9, when a force Fx in the X-axis positive direction, that is, a force Fx biased in the X-axis positive direction acts on the cover layer 31, a large force is applied to the portions corresponding to the detection regions D302 and D304. In accordance with the magnitude of the force Fx, the capacitance values of the capacitive elements C2 and C4 increase, and the values of the voltages V302 and V304 increase. At this time, since almost no force is applied to the portions corresponding to the detection regions D301 and D303, the capacitance values of the capacitive elements C1 and C3 hardly change, and the values of the voltages V301 and V303 hardly change.

  Similarly, when a force Fy in the positive Y-axis direction, that is, a force Fy biased in the positive Y-axis direction, acts on the cover layer 31, a large force is applied to the portions corresponding to the detection regions D303 and D304. Accordingly, the capacitance values of the capacitive elements C3 and C4 increase, and the values of the voltages V303 and V304 increase.

  Further, when the force Fz in the positive direction of the Z axis acts on the cover layer 31, a uniform force is applied to the portions corresponding to the detection regions D301, D302, D303, and D304, and therefore the capacitive element C1 according to the magnitude of the force Fz. , C2, C3, and C4 all increase in capacitance value, and voltages V301, V302, V303, and V304 all increase.

ここで、上記の表において記号「＋」は、センサシート１に外部から力が作用していないときを基準として各電圧値が増加したことを示し、無記号は各電圧値がほとんど変化しないことを示している。 The relationship between the forces Fx, Fy, and Fz in the X, Y, and Z axis directions and the voltages V301, V302, V303, and V304 is summarized in the table as follows.

Here, in the above table, the symbol “+” indicates that each voltage value has increased with reference to when no force is applied to the sensor sheet 1 from the outside, and no symbol indicates that each voltage value hardly changes. Is shown.

Using these characteristics, the components Fx, Fy, and Fz corresponding to the X-axis direction, the Y-axis direction, and the Z-axis direction of the force F acting on the cover layer 31 use the voltages V301, V302, V303, and V304, It is expressed by the following formula.
Fx = (V302 + V304) − (V30l + V303)
Fy = (V303 + V304) − (V30l + V302)
Fz = V30l + V302 + V303 + V304

  As described above, in the sensor sheet 301 according to the present embodiment, the capacitances of the capacitive elements C1, C2, C3, and C4 corresponding to the four detection regions arranged so that one core member 40 is straddled. Using the voltages V301, V302, V303, and V304 derived based on the values, the X-axis direction component Fx, the Y-axis direction component Fy, and the Z-axis direction component Fz of the force F applied to the sensor sheet 301 from the outside are respectively obtained. Can be detected.

  The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and various design changes can be made as long as they are described in the claims. For example, in the above-described first and second embodiments, the multi-directional component of the force applied from the outside is detected based on the change in the resistance value corresponding to the four detection regions, and in the third embodiment, Multiple direction components of the force applied from the outside based on the change in resistance value corresponding to the five detection areas are detected, but are applied from the outside based on the change in resistance value corresponding to the plurality of detection areas. What is necessary is just to be able to detect the multi-directional component of the applied force. Therefore, a multi-directional component of force applied from the outside may be detected based on a change in resistance value corresponding to two, three, or six or more detection regions.

  In the fourth embodiment described above, four detection areas are arranged in the same manner as in the first embodiment, but four detection areas are arranged in the same manner as in the second embodiment. Alternatively, five detection areas may be arranged in the same manner as in the third embodiment. That is, the resistance value of the pressure-sensitive resistor between the electrodes corresponding to the detection region is detected even when an externally applied force is detected based on the change in the capacitance value of the capacitive element between the electrodes corresponding to the detection region. As in the case where the externally applied force is detected based on the change in the number of components, the multidirectional component of the externally applied force is detected based on the change in the capacitance value corresponding to the plurality of detection regions. Anything is acceptable. Further, in the above-described fourth embodiment, the insulating member 312 disposed between the substrate 10 and the substrate 20 is disposed over the entire region of the portion corresponding to all the detection regions and the portion not corresponding to the detection regions. However, the insulating member disposed between the substrate 10 and the substrate 20 is disposed as a spacer only in a portion not corresponding to the detection region, and a portion corresponding to the detection region between the substrate 10 and the substrate 20 is a gap. It may be.

It is a partial appearance perspective view of a sensor sheet concerning a 1st embodiment of the present invention. It is a schematic diagram which shows schematic structure of the sensor sheet | seat of FIG. It is a figure showing arrangement of a plurality of detection fields in a sensor sheet. It is a schematic diagram which shows schematic structure of the sensor sheet | seat when force is applied from the outside. It is a figure which shows arrangement | positioning of the several detection area | region in the sensor sheet which concerns on the 2nd Embodiment of this invention. It is a figure showing arrangement of a plurality of detection fields in a sensor sheet concerning a 3rd embodiment of the present invention. It is a schematic diagram which shows schematic structure of the sensor sheet which concerns on the 3rd Embodiment of this invention. It is a figure showing arrangement of a plurality of detection fields in a sensor sheet. It is a schematic diagram which shows schematic structure of the sensor sheet | seat when force is applied from the outside.

Explanation of symbols

1, 101, 201, 301 Sensor sheet 2, 302 Basic unit 10 Substrate 11 First electrode 12 Pressure sensitive resistor 20 Substrate 21 Second electrode 22 Pressure sensitive resistor 30 Support member 31 Cover layer 40, 240 Core member 312 Insulating member D1-D4, D101-D104, D201-D205, D301-D304 Detection area

Claims (11)

A plurality of first electrodes that are strip-shaped and spaced apart from each other;
A plurality of strips that are spaced apart from each other and arranged so as to intersect with the plurality of first electrodes in plan view, and are displaceable in a direction close to the first electrodes in accordance with a force applied from the outside. A second electrode;
A plurality of pressure sensitive resistors arranged in a detection region where the first electrode and the second electrode overlap each other in at least a plan view between the plurality of first electrodes and the plurality of second electrodes;
A core member formed of a hard material disposed on a side opposite to the plurality of first electrodes with respect to the plurality of second electrodes and disposed across a plurality of the detection regions in a plan view. ,
Recognizing components corresponding to a plurality of different directions of force applied from the outside based on a change in resistance value between portions corresponding to each of the plurality of detection regions of the first electrode and the second electrode. A featured sensor sheet. A plurality of first electrodes that are band-shaped and spaced apart from each other;
A plurality of strips that are spaced apart from each other and arranged so as to intersect with the plurality of first electrodes in plan view, and are displaceable in a direction close to the first electrodes in accordance with a force applied from the outside. A second electrode;
Rigidly disposed on the opposite side of the plurality of first electrodes with respect to the plurality of second electrodes, and disposed across a plurality of detection regions in which the first electrode and the second electrode overlap in a plan view. A core member formed of a material of
The plurality of first electrodes and the plurality of second electrodes are insulated,
Recognizing components corresponding to a plurality of different directions of force applied from the outside based on a change in capacitance value between portions corresponding to each of the plurality of detection regions of the first electrode and the second electrode. A sensor sheet characterized by that.   3. The sensor sheet according to claim 1, wherein the plurality of detection areas are four detection areas arranged in line symmetry with respect to each of two straight lines orthogonal in a plan view.   The sensor sheet according to claim 3, wherein a center position of the core member coincides with a center position of the four detection regions in a plan view.   5. The sensor sheet according to claim 3, wherein at least a part of the end portion of the core member is located inside all of the four detection regions in a plan view.   The sensor sheet according to claim 1, wherein the core member is a cylindrical member.   The sensor sheet according to claim 1 or 2, wherein the plurality of detection regions are five detection regions arranged symmetrically with respect to each of two straight lines orthogonal to each other in plan view.   The sensor sheet according to claim 7, wherein a center position of the core member coincides with a center position of the five detection regions in a plan view.   The at least part of the edge part of the said core member is located inside all four detection area | regions outside the said 5 detection area | region in planar view, The Claim 7 or 8 characterized by the above-mentioned. Sensor sheet.   The sensor sheet according to claim 7, wherein the core member is a cylindrical member.   The sensor sheet according to any one of claims 1 to 10, wherein the units including the plurality of detection regions and the core member are arranged in a matrix.

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