JP2012073051A - Detector, electronic apparatus, and robot - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a detector, an electronic apparatus and a robot which can detect the magnitude and direction of external pressure with high accuracy.SOLUTION: A detector comprises a first substrate 10 having plural pressure sensors 12 arranged around a reference point P and a second substrate 20 having a unit projection 24 whose center of gravity is located at a position overlapping the reference point P and which elastically deforms with its tip being in contact with the first substrate 10 by external pressure. The unit projection 24 is composed of an elastic body projection 22 having high hardness and an elastic body layer 23 having low hardness.

Description

  The present invention relates to a detection device, an electronic device, and a robot.

  As detection devices for detecting an external force, detection devices described in Patent Literature 1 and Patent Literature 2 are known. Application of such a detection apparatus to a touch panel, a tactile sensor of a robot, or the like is being studied.

Japanese Patent Laid-Open No. 60-135834 JP-A-7-128163

The detection device of Patent Document 1 is configured to detect a pressure distribution from a deformation amount of a protrusion using a pressure-receiving sheet having conical protrusions arranged substantially uniformly on the back surface. However, the detection device of Patent Document 1 cannot measure the in-plane force (sliding force) of the pressure applied to the measurement surface.
The detection device of Patent Document 2 has a configuration in which a plurality of columnar protrusions are arranged in a grid pattern on the surface of a pressure-receiving sheet, and a conical protrusion is provided on the back surface of a portion obtained by equally dividing the periphery of these surface protrusions. . In the detection device of Patent Document 2, it is possible to detect the external pressure as a three-dimensional force vector, but the detection limit of the external pressure is determined by the degree of deformation of the protrusion.
As described above, none of the detection devices of Patent Literature 1 and Patent Literature 2 can detect the direction and magnitude of the external pressure with high accuracy.

  The present invention has been made in view of such circumstances, and an object thereof is to provide a detection device, an electronic apparatus, and a robot capable of detecting the direction and magnitude of external pressure with high accuracy.

  In order to solve the above problems, a detection device of the present invention is a detection device that detects the direction and magnitude of an external pressure applied to a reference point, and includes a plurality of pressure sensors arranged around the reference point. A first substrate, and a second substrate on which a unit protrusion is formed that is elastically deformed in a state where a center of gravity is located at a position overlapping the reference point and a tip portion is in contact with the first substrate by external pressure, The protrusion is formed of two or more kinds of elastic materials having different hardnesses.

  According to this detection device, the tip of the unit protrusion can be deformed in a sliding direction (a direction parallel to the pressure sensor surface) in a state where the tip of the unit protrusion is in contact with the first substrate (a plurality of pressure sensors). The detection accuracy of the direction and the size of can be improved. When an external pressure is applied to the surface of the second substrate, the unit protrusion is compressed and deformed with the tip portion in contact with the first substrate. At this time, when there is a sliding force component in a predetermined direction in the plane, the unit protrusion is biased in deformation. That is, the center of gravity of the unit protrusion is shifted from the reference point and moves in a predetermined direction (slip direction). As a result, the ratio of the plurality of pressure sensors that overlap with the portion where the center of gravity of the unit protrusion has moved becomes relatively large. That is, different pressure values are detected by each pressure sensor. Specifically, a relatively large pressure value is detected by the pressure sensor at a position overlapping with the center of gravity of the unit protrusion, and a relatively small pressure value is detected by a pressure sensor at a position not overlapping with the center of gravity of the unit protrusion. Become. Therefore, the difference between the pressure values detected by the pressure sensors can be calculated, and the direction and magnitude in which the external pressure is applied can be obtained based on the difference. Therefore, it is possible to provide a detection device that can detect the direction and magnitude of the external pressure with high accuracy. In the present invention, since the unit protrusion is formed using two or more kinds of elastic materials having different hardnesses, the deformation of the region formed of the elastic material having low hardness in the unit protrusion with respect to the external pressure in the sliding direction. Becomes larger. Specifically, a relatively very large pressure value is detected by the pressure sensor at a position overlapping with the center of gravity of the unit protrusion, and a relatively small pressure value is detected by a pressure sensor at a position not overlapping with the center of gravity of the unit protrusion, The difference is very large. Therefore, the direction of the external pressure can be detected with high accuracy.

In the detection device described above, the unit protrusion includes an elastic protrusion made of a first elastic material, and an elastic body layer formed so as to cover the elastic protrusion, and the elastic body layer includes the first protrusion. It consists of the 2nd elastic material whose hardness is lower than 1 elastic material.
Furthermore, the elastic body layer may be formed on the side surface portion of the elastic protrusion and not on the tip portion of the elastic protrusion.

  According to this detection apparatus, the central portion (elastic protrusion) of the unit protrusion is formed of an elastic material having high hardness, and the outer peripheral portion (elastic body layer) formed so as to cover the unit protrusion is formed of an elastic material having low hardness. Therefore, for external pressure in the sliding direction, deformation of the region formed of the elastic material having low hardness constituting the outer peripheral portion of the unit protrusion is caused by the elastic material having high hardness constituting the central portion. It becomes larger than the deformation of the formed region. Therefore, the pressure sensor at a position that overlaps the center of gravity of the unit protrusion detects a relatively large pressure value, and the pressure sensor at a position that does not overlap with the center of gravity of the unit protrusion detects a relatively small pressure value. It will be very big. Therefore, the direction of the external pressure can be detected with high accuracy. Further, in the case where the elastic body layer is formed on the side surface portion of the elastic protrusion and is not formed on the tip end portion of the elastic protrusion, the center of gravity of the unit protrusion is determined in a state where a sliding force is applied. In the pressure sensor at a position where they do not overlap, the deformation of the unit protrusion is very small, and a relatively small pressure value is detected.

  In the detection device described above, a difference between the pressure values detected by the pressure sensors arbitrarily combined among the pressure values detected by the plurality of pressure sensors by elastically deforming the unit protrusion by an external pressure. And a computing device that computes the direction in which the external pressure is applied and the magnitude of the external pressure based on the difference.

  In the detection apparatus described above, the plurality of pressure sensors may be arranged point-symmetrically with respect to the reference point.

  According to this detection apparatus, since the distance between the reference point and each pressure sensor becomes equal to each other, the relationship between the deformation amount of the unit protrusion and the pressure value detected by each pressure sensor becomes equal to each other. For example, when a plurality of pressure sensors are arranged at different distances from the reference point, even if the deformation amount of the unit protrusion is the same, the pressure values detected by the pressure sensors are different from each other. For this reason, when calculating the difference between the detection values, a correction coefficient corresponding to the arrangement position of each pressure sensor is required. However, according to this configuration, the relationship between the deformation amount of the unit protrusion and the pressure value detected by each pressure sensor becomes equal to each other, and thus the correction coefficient is not necessary. Therefore, it becomes easy to calculate the direction and magnitude of the external pressure from the pressure value detected by each pressure sensor, and the external pressure can be detected efficiently.

  In the detection apparatus described above, the plurality of pressure sensors may be arranged in a matrix in two directions orthogonal to each other.

  According to this detection device, it becomes easy to calculate the direction and magnitude of the external pressure from the difference between the pressure values of the pressure sensors arbitrarily combined among the pressure values of the pressure sensors.

  In the above-described detection device, the plurality of pressure sensors may be arranged in at least 4 rows and 4 columns in two directions orthogonal to each other.

  According to this detection device, the number of arranged pressure sensors increases. For this reason, the direction in which the external pressure acts can be obtained by integrating the detection results of the pressure sensors based on the pressure values detected by a large number of pressure sensors. Therefore, the direction of the external pressure can be detected with high accuracy.

  In the detection device described above, a plurality of the unit protrusions may be formed on the second substrate, and the plurality of unit protrusions may be arranged apart from each other.

  According to this detection apparatus, it is possible to allow a deformation amount in a direction parallel to the plane of the second substrate body when the unit protrusion is elastically deformed. For example, when one unit projection is deformed, it is possible to suppress the deformation of the other unit projection. For this reason, compared with the case where the plurality of unit protrusions are arranged in contact with each other, the external pressure can be accurately transmitted to each pressure sensor. Therefore, the direction and magnitude of the external pressure can be detected with high accuracy.

  In the detection device, as an application example, a reinforcing member having rigidity higher than that of the second substrate may be disposed on a side opposite to the side on which the unit protrusion is formed of the second substrate.

  According to the detection device as in the application example, for example, when the external pressure acts on a region between two adjacent unit protrusions, the two adjacent unit protrusions are in directions opposite to each other compared to the case where there is no reinforcing member. It is possible to suppress the compression deformation. That is, it is possible to suppress erroneous detection such as detecting a direction opposite to the direction in which the external pressure is applied. Therefore, the direction of the external pressure can be detected with high accuracy.

  An electronic apparatus according to the present invention includes the detection device described above.

  According to this electronic apparatus, since the above-described detection device is provided, it is possible to provide an electronic apparatus that can detect the direction and magnitude of the external pressure with high accuracy.

  A robot according to the present invention includes the detection device described above.

  According to this robot, since the above-described detection device is provided, it is possible to provide a robot capable of detecting the direction and magnitude of the external pressure with high accuracy.

Sectional drawing which shows schematic structure of the unit protrusion which concerns on 1st Embodiment of this invention. The disassembled perspective view which shows schematic structure of the detection apparatus which concerns on 1st Embodiment of this invention. Sectional drawing which shows the change of the pressure value by the pressure sensor which concerns on 1st Embodiment. The top view which shows the change of the pressure value by the pressure sensor which concerns on 1st Embodiment. The figure which shows the coordinate system of the sensing area | region which concerns on 1st Embodiment. The figure which shows the pressure distribution of the perpendicular direction by the pressure sensor which concerns on 1st Embodiment. The figure which shows the example of calculation of the slip direction by the pressure sensor which concerns on 1st Embodiment. The disassembled perspective view which shows schematic structure of the detection apparatus which concerns on 2nd Embodiment of this invention. Sectional drawing which shows the change of the pressure value by the pressure sensor which concerns on 2nd Embodiment. The top view which shows the change of the pressure value by the pressure sensor which concerns on 2nd Embodiment. The figure which shows the coordinate system of the sensing area | region which concerns on 2nd Embodiment. The disassembled perspective view which shows schematic structure of the detection apparatus which concerns on the application example of this invention. Sectional drawing which shows the change of the pressure value by the pressure sensor which concerns on an application example. Sectional drawing which shows three types of typical structures of this invention. Sectional drawing which shows another three types of typical structures of this invention. FIG. 2 is a schematic diagram illustrating a schematic configuration of a mobile phone that is an example of an electronic apparatus. The schematic diagram which shows schematic structure of the portable information terminal which is an example of an electronic device. The schematic diagram which shows schematic structure of the robot hand which is an example of a robot.

Embodiments of the present invention will be described below with reference to the drawings. This embodiment shows one aspect of the present invention, and does not limit the present invention, and can be arbitrarily changed within the scope of the technical idea of the present invention. Moreover, in the following drawings, in order to make each structure easy to understand, an actual structure and a scale, a number, and the like in each structure are different.
In the present embodiment, the “surface” of the first substrate refers to a plurality of pressure sensor formation surfaces of the first substrate body. The “surface” of the second substrate refers to a surface opposite to the unit protrusion forming surface of the second substrate body, that is, a surface that receives external pressure.

(First embodiment)
A unit area of the detection device of the present embodiment will be described. FIG. 1 shows a state in which a second substrate having unit protrusions that are elastically deformed is arranged on a first substrate having a plurality of pressure sensors arranged in the detection apparatus according to the first embodiment of the present invention. It is sectional drawing which shows a representative example. FIG. 1 illustrates a unit region of the detection device.

As shown in FIG. 1, the detection apparatus 1 includes a first substrate 10 and a second substrate 20. The first substrate 10 is formed by forming a plurality of pressure sensors 12 on a first substrate body 11. The second substrate 20 is formed by arranging a plurality of unit protrusions 24 on a rectangular plate-like second substrate body 21 corresponding to the pressure sensor.
The unit region of the detection device 1 is formed so that the pressure sensor 12 disposed on the first substrate body 11 and the tip of the unit protrusion 24 are in contact with each other.
The unit protrusion 24 includes an elastic protrusion 22 that forms a central portion, and an elastic layer 23 that forms an outer peripheral portion so as to cover the elastic protrusion 22. Further, the first elastic material forming the elastic protrusions 22 and the second elastic material forming the elastic body layer 23 have different hardnesses. In the present embodiment, the second elastic material has a lower hardness than the first elastic material.

  The shapes of the elastic protrusions 22 and the unit protrusions 24 may be hemispherical, conical or columnar.

  In the following description, the XYZ orthogonal coordinate system shown in FIG. 2 is set, and each member will be described with reference to this XYZ orthogonal coordinate system. In the XYZ orthogonal coordinate system, the X axis and the Y axis are set in a direction parallel to the first substrate 10, and the Z axis is set in a direction orthogonal to the first substrate 10.

  FIG. 2 is an exploded perspective view showing a schematic configuration of the detection apparatus 1 according to the first embodiment of the present invention. In FIG. 2, reference symbol P denotes a reference point, and reference symbol S denotes a unit detection region detected by a plurality of pressure sensors 12 arranged corresponding to one unit protrusion 24.

  The detection device 1 is a pressure sensor type touch pad that detects the direction and magnitude of an external pressure applied to the reference point P, and is used as a pointing device in place of a mouse in an electronic device such as a notebook computer. . The “reference point” is a point at which the center (center of gravity) of the unit protrusion 24 is located in plan view when no sliding force is applied.

  As shown in FIG. 2, the detection device 1 includes a first substrate 10 having a plurality of pressure sensors 12 arranged around a reference point P, a center of gravity located at a position overlapping the reference point P, and a distal end portion due to external pressure. And a second substrate 20 formed with unit protrusions 24 that are elastically deformed while being in contact with the first substrate 10.

  The detection device 1 calculates the difference between the pressure values detected by the pressure sensors arbitrarily combined among the pressure values detected by the plurality of pressure sensors 12 due to the elastic deformation of the unit protrusion 24 due to the external pressure, An arithmetic device (not shown) that calculates the direction and magnitude of the external pressure applied based on the difference is provided.

  The first substrate 10 includes a rectangular plate-shaped first substrate body 11 made of a material such as glass, quartz, and plastic, for example, and a plurality of pressure sensors 12 arranged on the first substrate body 11. It is configured. For example, the size (size in plan view) of the first substrate body 11 is about 56 mm long × 56 mm wide.

  The plurality of pressure sensors 12 are arranged point-symmetrically with respect to the reference point P. For example, the plurality of pressure sensors 12 are arranged in a matrix in two directions (X direction and Y direction) orthogonal to each other. Thereby, since the distance between the reference point P and each pressure sensor 12 becomes equal to each other, the relationship between the deformation of the unit protrusion 24 and the pressure value detected by each pressure sensor 12 becomes equal to each other. Therefore, it becomes easy to calculate the difference between the pressure values detected by the pressure sensors 12 arbitrarily combined among the pressure values of the pressure sensors 12. A method for calculating the difference between the pressure values will be described later.

  The interval between the adjacent pressure sensors 12 is about 0.1 mm. For this reason, noise is not applied to the pressure value detected by the pressure sensor 12 at the adjacent position due to the influence of disturbance, static electricity, or the like.

  The plurality of pressure sensors 12 are arranged in a total of four in two vertical rows and two horizontal columns per unit detection region S. The center of the four pressure sensors 12 (the center of the unit detection region S) is the reference point P. For example, the size of the unit detection area S (size in plan view) is about 2.8 mm long × 2.8 mm wide. Further, the areas of the four pressure sensors 12 are substantially equal.

  As the pressure sensor 12, for example, a pressure sensitive element such as a diaphragm gauge can be used. In this case, the pressure applied to the diaphragm when an external pressure acts on the contact surface is converted into an electrical signal.

  In addition, as the pressure sensor 12, a resistance value change type pressure sensitive element can be used. For example, a pressure sensitive element composed of a pressure sensitive conductive rubber or the like is known. When the upper and lower electrodes are provided on the upper and lower surfaces of the pressure-sensitive conductive rubber sheet, the external pressure can be detected by sensing the change in the resistance value in the film thickness direction of the pressure-sensitive conductive rubber sheet. I can do it. In addition, when a parallel electrode or a comb-like electrode is provided on either surface of the pressure-sensitive conductive rubber sheet, if an external pressure is applied, a change in the resistance value in the horizontal direction of the pressure-sensitive conductive rubber sheet is detected to detect the external pressure. Can be detected.

  In addition, as the pressure sensor 12, a capacitance value change type pressure sensitive element can be used. In this case, when the external pressure is applied, the external pressure can be detected by sensing a change in the capacitance value.

  The second substrate 20 includes a rectangular plate-shaped second substrate body 21 and a plurality of unit protrusions 24 disposed on the second substrate body 21. The unit protrusion 24 includes an elastic protrusion 22 that forms a central portion, and an elastic layer 23 that forms an outer peripheral portion of the elastic protrusion 22. Further, the first elastic material forming the elastic protrusion 22 and the second elastic material forming the elastic layer 23 have different hardness. In this embodiment, the hardness of the second elastic material is lower than the hardness of the first elastic material.

  The second substrate body 21 is a part that directly receives external pressure. The second substrate body 21 can be made of a material such as glass, quartz, and plastic, or can be made of a resin material such as a urethane foam resin or a silicone resin. In the present embodiment, a resin material is used as a material for forming the second substrate body 21 and the elastic protrusions 22, and the second substrate body 21 and the elastic protrusions 22 are integrally formed with a mold. Next, the elastic body layer 23 is formed on the outer peripheral portion of the elastic protrusion 22. For example, a solution of a second elastic material having a lower hardness than the first elastic material forming the elastic protrusions 22 may be formed on the surface of the elastic protrusions 22 by spraying or dipping. I can do it.

  The plurality of unit protrusions 24 are arranged in a matrix in the X direction and the Y direction on the second substrate body 21. The tip of the unit protrusion 24 is a hemisphere having a spherical surface, and is in contact with the first substrate 10 (the plurality of pressure sensors 12 on the first substrate body 11). The center of gravity of the unit protrusion 24 is initially arranged at a position overlapping the reference point P. Further, the plurality of unit protrusions 24 are arranged to be separated from each other. For this reason, it is possible to allow a deformation amount in a direction parallel to the plane of the second substrate body 21 when the unit protrusion 24 is elastically deformed.

  The size of the unit protrusion 24 can be set arbitrarily. Here, the diameter of the base of the unit protrusion 24 (the diameter of the portion where the unit protrusion 24 contacts the first substrate 10) is about 1.8 mm. The diameter of the base portion of the elastic protrusion 22 (the diameter of the portion where the elastic protrusion 22 is in contact with the first substrate 10 via the elastic layer 23) is 1.8 mm or less. For example, the size may be about 0.5 mm to 1.6 mm. On the other hand, the height of the unit protrusion 24 (distance in the Z direction of the unit protrusion 24) is about 2 mm. The height of the elastic protrusion 22 (the distance in the Z direction of the elastic protrusion 22) is 2 mm or less. For example, the size may be about 0.5 mm to 1.9 mm. Further, the spacing between adjacent unit protrusions 24 is about 1 mm. The durometer hardness (type A, measured by a durometer in accordance with ISO 7619) of the elastic protrusion 22 is about 30 to 60. The elastic layer 23 is made of a material whose durometer hardness is smaller than the durometer hardness of the elastic protrusion 22. For example, about 10-30 may be sufficient.

3 and 4 are explanatory diagrams of a method for detecting the direction of the external pressure acting on the reference point P. FIG.
FIGS. 3A to 3C are cross-sectional views illustrating changes in pressure values by the pressure sensor according to the first embodiment. FIGS. 4A to 4C are plan views showing changes in the pressure value by the pressure sensor according to the first embodiment, corresponding to FIGS. 3A to 3C. 3A and 4A show a state before external pressure is applied to the surface of the second substrate 20 (when there is no external pressure action). FIG. 3B and FIG. 4B show a state in which an external pressure in the vertical direction (in the absence of sliding force) is applied to the surface of the second substrate 20. FIG. 3C and FIG. 4C show a state in which an external pressure in an oblique direction (with a sliding force) is applied to the surface of the second substrate 20. 4A to 4C, the symbol G indicates the center of gravity (pressure center) of the unit protrusion 24, the symbol G1 indicates the center of gravity of the elastic protrusion 22, and the symbol G2 indicates the center of gravity of the elastic layer 23. . In the following description, the embodiment will be described by taking as an example the case where the unit protrusions 24 are formed so that the respective centers of gravity overlap. In the present invention, the center of gravity G1 and the center of gravity G2 do not necessarily overlap.

As shown in FIGS. 3A and 4A, before the external pressure is applied to the surface of the second substrate 20, the unit protrusion 24 is not deformed. That is, the elastic protrusion 22 and the elastic layer 23 are not deformed. Thereby, the distance between the first substrate 10 and the second substrate 20 is kept constant.
At this time, the center of gravity G of the unit protrusion 24, the center of gravity G1 of the elastic body protrusion 22, and the center of gravity G2 of the elastic body layer 23 are arranged at positions overlapping the reference point P. The pressure value of each pressure sensor 12 at this time is stored in a memory (not shown). The direction and magnitude of the external pressure acting are determined based on the pressure value of each pressure sensor 12 stored in the memory.

  FIG. 4A shows a relative position 30 of the base portion of the unit protrusion 24 with respect to the plurality of pressure sensors 12 and the reference point P and a region 40 where the first substrate 10 and the unit protrusion 24 are in contact with each other when no external pressure is applied. Show. In this state, only the elastic layer 23 is often deformed to come into contact with the first substrate 10. Therefore, in FIG. 4A, the region 40 where the first substrate 10 and the unit protrusion 24 are in contact with each other is equivalent to the region where the first substrate 10 and the elastic layer 23 are in contact with each other. Further, the positions G, G1, G2 of the center of gravity and the position of the reference point P overlap each other.

  As shown in FIG. 3B and FIG. 4B, when the external pressure in the vertical direction is applied to the surface of the second substrate 20, the tip of the unit protrusion 24 is disposed on the surface of the first substrate 10. It compresses and deforms in the Z direction in contact with the plurality of pressure sensors 12. Due to the external force in the vertical direction, the positions of the centers of gravity G, G1, and G2 remain overlapped and do not shift. As a result, the second substrate 20 bends in the −Z direction, and the distance between the first substrate 10 and the second substrate 20 becomes smaller than when there is no external pressure. The pressure value of the pressure sensor 12 at this time becomes larger than when there is no external pressure. The amount of change is substantially the same for each pressure sensor 12. According to the present embodiment, the unit protrusion 24 is formed of the elastic protrusion 22 having a high hardness at the center and the elastic layer 23 having a hardness lower than that of the elastic protrusion 22 at the outer periphery. The amount of deformation of the layer 23 increases. Therefore, the effect that the detection sensitivity of the magnitude of the external pressure is improved can be obtained as compared with the case where the unit protrusion 24 is formed of a single material.

  When an external pressure in the vertical direction is applied to the surface of the second substrate 20, the unit protrusion 24 is greatly deformed, and not only the elastic body layer 23 but also the elastic body protrusion 22 passes through the elastic body layer 23. To touch. In this state, the relative position 30 of the base of the unit protrusion 24 with respect to the plurality of pressure sensors 12 and the reference point P, the region 40 where the first substrate 10 and the elastic layer 23 are in contact, the first substrate and the elastic protrusion 22 FIG. 4B shows a region 50 that is in contact with each other through the elastic layer 23. Since the elastic layer 23 has a lower hardness than the elastic protrusions 22, it is easily deformed, and a region 40 where the first substrate 10 and the elastic layer 23 are in contact with each other is large. In this case as well, the positions of the centroids G, G1, and G2 and the position of the reference point P are overlapped.

  As shown in FIG. 3C and FIG. 4C, when an external pressure is applied to the surface of the second substrate 20 in an oblique direction, the unit protrusion 24 has the tip portion disposed on the surface of the first substrate 10. In a state where it is in contact with the plurality of pressure sensors 12, it is inclined and compressed and deformed. As a result, the second substrate 20 bends in the −Z direction, and the distance between the first substrate 10 and the second substrate 20 becomes smaller than when there is no external pressure. At this time, the center of gravity G of the unit protrusion 24 is shifted from the reference point P in the + X direction and the + Y direction. In this case, the overlapping areas of the tip of the unit protrusion 24 and the four pressure sensors 12 are different. Specifically, the area where the tip of the unit protrusion 24 overlaps with the four pressure sensors 12 is larger than the area where the pressure sensors 12 arranged in the −X direction and the −Y direction among the four pressure sensors 12 overlap. The area overlapping with the pressure sensors 12 arranged in the + X direction and the + Y direction becomes larger.

  The unit protrusion 24 is biased in deformation due to an external pressure in an oblique direction. That is, the center of gravity of the elastic protrusion 22 is displaced from the reference point P and moves in the sliding direction (X direction and Y direction). Then, different pressure values are detected by each pressure sensor. Specifically, a relatively large pressure value is detected by the pressure sensor 12 at a position overlapping with the center of gravity G1 of the elastic protrusion 22 and relatively small at the pressure sensor 12 at a position not overlapping with the center of gravity G1 of the elastic protrusion 22. A pressure value will be detected. And the direction of the external pressure applied based on the calculation method of the difference mentioned later is calculated | required.

  In the present embodiment, the unit protrusion 24 is formed of the elastic protrusion 22 having a high hardness at the center and the elastic layer 23 having a lower hardness than the elastic protrusion 22 at the outer peripheral portion. Is larger than the deformation amount of the elastic protrusion 22. Therefore, the amounts of displacement of the positions of the center of gravity G1, G2 are different. The position of the center of gravity G of the unit protrusion 24 is obtained by adding the shift of the position of the center of gravity G1 of the elastic body protrusion 22 and the shift of the position of the center of gravity G2 of the elastic body layer 23. Therefore, the effect that the detection sensitivity in the direction of the external pressure is improved can be obtained as compared with the case where the unit protrusion 24 is formed of a single material.

When an external pressure in an oblique direction is applied to the surface of the second substrate 20, the unit protrusion 24 is greatly deformed, and the unit protrusion 24 is in contact with the first substrate 10. The position 30 is shifted. FIG. 4C shows that the relative position 30 of the base of the unit protrusion 24 with respect to the sensor 12 and the reference point P is shifted in the direction of the external force.
Further, the region 40 where the first substrate 10 and the elastic body layer 23 are in contact with each other and the region 50 where the first substrate 10 and the elastic body protrusion 22 are in contact with each other through the elastic body layer 23 are biased by the external pressure in the oblique direction. It shows that it has occurred. Furthermore, the center of gravity G1 of the elastic protrusion 22, the center of gravity G2 of the elastic body layer 23, and the center of gravity G of the unit protrusion 24 are shifted from the reference point P. Since the elastic body layer 23 has a lower hardness than the elastic body protrusions 22 and is easily deformed, the first substrate 10 and the elastic protrusions 22 are more deformed than the deformation bias of the region 50 in contact with the elastic body layer 23. The bias in deformation of the region 40 where the substrate 10 and the elastic layer 23 are in contact with each other increases.

  FIG. 5 is a diagram illustrating a coordinate system of the sensing area according to the first embodiment. FIG. 6 is a view showing a pressure distribution in the vertical direction by the pressure sensor according to the first embodiment. FIG. 7 is a diagram illustrating a calculation example of the slip direction by the pressure sensor according to the first embodiment.

As shown in FIG. 5, the plurality of pressure sensors S1 to S4 are arranged in a total of four rows per unit detection region S in two rows and two columns.
Here, when the pressure values (detected values) detected by the pressure sensors S1 to S4 are P _S1 , P _S2 , P _S3 , and P _S4 , the X direction component Fx of the external force (X of the in-plane direction components of the external force) The ratio of the component force acting in the direction) is expressed by the following equation (1).
Further, the Y direction component Fy of the external force (the ratio of the component force acting in the Y direction among the in-plane direction components of the external force) is expressed by the following equation (2).
Further, the Z direction component Fz of the external force (vertical direction component of the external force, the Z axis is omitted in FIG. 5) is expressed by the following equation (3).

  In the present embodiment, the unit protrusion 24 is elastically deformed by an external pressure to calculate the difference between the pressure values detected by the pressure sensors arbitrarily combined among the pressure values detected by the four pressure sensors S1 to S4. The direction in which the external pressure is applied is calculated based on the difference.

  As shown in Expression (1), the X direction component Fx of the external pressure is detected by the pressure sensor S2 disposed in the + X direction and the pressure sensor S4 among the pressure values detected by the four pressure sensors S1 to S4. The values detected by the pressure sensor S1 and the pressure sensor S3 arranged in the −X direction are combined. Thus, based on the difference between the pressure value obtained by the combination of the pressure sensor S2 and the pressure sensor S4 arranged in the + X direction and the pressure value obtained by the combination of the pressure sensor S1 and the pressure sensor S3 arranged in the -X direction. The X direction component of the external pressure is obtained.

  As shown in Expression (2), the Y-direction component Fy of the external pressure is detected by the pressure sensor S1 and the pressure sensor S2 arranged in the + Y direction among the pressure values detected by the four pressure sensors S1 to S4. The values detected by the pressure sensor S3 and the pressure sensor S4 arranged in the -Y direction are combined. Thus, the external pressure is based on the difference between the pressure value obtained by the combination of the pressure sensor S1 and the pressure sensor S2 arranged in the + Y direction and the pressure value obtained by the combination of the pressure sensor S3 and the pressure sensor S4 arranged in the -Y direction. A Y direction component is obtained.

  As shown in Expression (3), the Z direction component Fz of the external pressure is obtained by a resultant force obtained by adding the pressure values of the four pressure sensors S1 to S4. However, the detected value of the Z direction component Fz of the external pressure tends to be detected larger than the X direction component Fx of the external pressure and the Y direction component Fy (component force) of the external pressure. For example, when a hard material is used as the material of the unit protrusion 24 or the shape of the tip is sharpened, the detection sensitivity of the Z-direction component Fz of the external pressure increases. However, if a hard material is used for the unit protrusion 24, the unit protrusion 24 is not easily deformed, and the detected value in the in-plane direction of the external pressure is reduced. Further, when the shape of the tip of the unit protrusion 24 is sharpened, a strong sensitivity (discomfort) may be given to the touch feeling when the contact surface is touched with a finger. For this reason, in order to align the detected value of the Z direction component Fz of the external pressure with the detected values of the X direction component Fx of the external pressure and the Y direction component Fy of the external pressure, detection is performed with a correction coefficient determined by the material and shape of the unit protrusion 24. It is necessary to correct the value appropriately.

  As shown in FIG. 6, consider a case where a position on the upper left side of the center of the detection surface of the touchpad is pushed diagonally with a finger. At this time, the pressure in the vertical direction of the external pressure is the largest at the center of the portion where the external pressure is applied (the output voltage of the pressure sensors S1 to S4 is about 90 to 120 mV). In addition, the vertical pressure of the external pressure is next to the peripheral part (the output voltage of the pressure sensors S1 to S4 is about 60 to 90 mV) and the outermost part (the output voltage of the pressure sensors S1 to S4 is about 30 to 60 mV) next to the central part. It becomes smaller in order. Moreover, the output voltage of the pressure sensors S1 to S4 is about 0 to 30 mV in the region not pressed by the finger. The touchpad has a unit detection area (area in which four pressure sensors S1 to S4 are arranged in two rows and two columns) in a matrix (for example, 225 in a total of 15 rows x 15 columns). Suppose it is placed.

  As shown in FIG. 7, a method for calculating the in-plane direction component (slip direction) of the external pressure when the position on the upper left side of the center of the detection surface of the touchpad is obliquely pressed with a finger will be considered. At this time, it is assumed that the finger pressing force (external force) acts on the portion arranged in the vertical 3 rows × horizontal 3 columns among the vertical rows 15 × horizontal 15 columns. Here, the pressure in the vertical direction of the external pressure is the largest at the central portion of the portion where the external pressure is applied as in FIG. 6 (110 mV).

  Each unit detection area arranged in 3 rows x 3 columns has four pressure sensors S1 to S4, which are arbitrarily combined among the pressure values detected by the pressure sensors S1 to S4. The difference between the pressure values detected by each pressure sensor is calculated, and the direction in which the external pressure is applied is calculated based on the difference. That is, in each unit detection region, the X-direction component Fx of the external pressure and the Y-direction component Fy of the external pressure are calculated based on the above formulas (1) and (2). Here, it can be seen that the external pressure acts in the direction of about 123 ° counterclockwise with respect to the + X direction. In calculating the direction in which the external pressure acts, the calculation is performed by the average value of the nine calculation results or the maximum value (for example, a detection value larger than a predetermined threshold value) of the nine calculation results. The method can be used.

According to the detection device 1 of the present embodiment, the tip of the unit protrusion 24 is deformed in the sliding direction (direction parallel to the surface of the pressure sensor 12) in a state where the tip of the unit protrusion 24 is in contact with the first substrate 10 (the plurality of pressure sensors 12). Therefore, the detection accuracy of the direction of the external pressure can be increased. When an external pressure in a predetermined direction is applied to the surface of the second substrate 20, the unit protrusion 24 is compressed and deformed in a state where the tip portion is in contact with the plurality of pressure sensors 12 arranged on the first substrate 10. At this time, the deformation of the unit protrusion 24 is biased. That is, the center of gravity of the unit protrusion 24 deviates from the reference point P and moves in a predetermined direction (slip direction). As a result, the ratio of the plurality of pressure sensors 12 that overlap with the portion where the center of gravity of the unit protrusion 24 has moved relatively increases. That is, different pressure values are detected by the pressure sensors S1 to S4.
Specifically, a relatively large pressure value is detected by the pressure sensor 12 at a position overlapping the gravity center G of the unit protrusion 24, and a relatively small pressure value is detected by the pressure sensor 12 at a position not overlapping with the gravity center G of the unit protrusion 24. Will be detected. Therefore, the calculation device can calculate the difference between the pressure values detected by the pressure sensors S1 to S4, and can determine the direction in which the external pressure is applied based on the difference. In the present embodiment, the unit protrusion 24 is formed by the elastic protrusion 22 having a high hardness at the center and the elastic layer 23 having a lower hardness than the elastic protrusion 22 at the outer peripheral portion. Is larger than the deformation amount of the elastic protrusion 22. Therefore, the position of each center of gravity is shifted. The position of the center of gravity G of the unit protrusion 24 is obtained by adding the shift of the position of the center of gravity G1 of the elastic body protrusion 22 and the shift of the position of the center of gravity G2 of the elastic body layer 23. Therefore, compared with the case where the unit protrusion 24 is formed of a single material, an effect that the detection sensitivity in the direction of the external pressure is improved can be obtained. Therefore, it is possible to provide the detection device 1 that can detect the direction of the external pressure with high accuracy.

  According to this configuration, since the plurality of pressure sensors 12 are arranged point-symmetrically with respect to the reference point P, the distances between the reference point P and each pressure sensor 12 are equal to each other. For this reason, the pressure values detected by the pressure sensors S1 to S4 are equal to each other. For example, when a plurality of pressure sensors are arranged at different distances from the reference point, the pressure values detected by the pressure sensors are different from each other. For this reason, when calculating the difference between the detected values, a correction coefficient corresponding to the arrangement position of each pressure sensor S1 to S4 is required. However, according to this configuration, since the pressure values detected by the pressure sensors S1 to S4 are equal to each other, the correction coefficient is not necessary. Therefore, it becomes easy to calculate the difference between the pressure values of the pressure sensors S1 to S4, and the external pressure can be detected efficiently.

  According to this configuration, since the plurality of pressure sensors 12 are arranged in a matrix in two directions orthogonal to each other, the pressure sensors 12 arbitrarily combined among the pressure values detected by the pressure sensors S1 to S4. It becomes easy to calculate the difference between the pressure values detected in step. For example, when calculating the X-direction component among the in-plane direction components, the pressure sensor S2 relatively disposed in the + X direction and the case where the plurality of pressure sensors 12 are randomly disposed in the plurality of directions, and It becomes easy to select the combination of the pressure sensor S4 and the combination of the pressure sensor S1 and the pressure sensor S3 arranged in the -X direction relatively. Therefore, the external pressure can be detected efficiently.

  According to this configuration, since the plurality of unit protrusions 24 are spaced apart from each other, the amount of deformation in a direction parallel to the plane of the second substrate body 21 when the unit protrusions 24 are elastically deformed is allowed. Can do. For example, when one unit protrusion 24 is deformed, the other unit protrusion 24 can be prevented from being affected by the deformation. For this reason, compared with the case where the plurality of unit protrusions 24 are arranged in contact with each other, the external pressure can be efficiently transmitted to the pressure sensors S1 to S4. Therefore, the direction and magnitude of the external pressure can be detected with high accuracy.

  In the present embodiment, an example in which a total of four pressure sensors 12 are arranged in two vertical rows and two horizontal columns per unit detection region S has been described. However, the present invention is not limited to this. Three or more pressure sensors 12 may be disposed per unit detection region S.

(Second Embodiment)
FIG. 8 is an exploded perspective view showing a schematic configuration of the detection apparatus 2 according to the second embodiment of the present invention, corresponding to FIG. In FIG. 8, reference symbol P denotes a reference point, and reference symbol S denotes a unit detection region detected by a plurality of pressure sensors 112 arranged corresponding to one unit protrusion 24.
The detection device 2 of the present embodiment is different from the detection device 1 described in the first embodiment in that a plurality of pressure sensors 112 are arranged in at least four rows and four columns in two directions orthogonal to each other. Different. 8, elements similar to those in FIG. 2 are denoted by the same reference numerals, and detailed description thereof is omitted. In FIG. 8, for the sake of convenience, a plurality of pressure sensors 112 are arranged in four rows and four columns per unit detection region S. Actually, as shown in FIGS. 112 may be arranged in four vertical rows and four horizontal columns or more per unit detection area S.

  As shown in FIG. 8, the detection device 2 includes a first substrate 110 having a plurality of pressure sensors 112 arranged around the reference point P, a center of gravity located at a position overlapping the reference point P, and a distal end portion due to external pressure. And a second substrate 20 formed with unit protrusions 24 that are elastically deformed while being in contact with the first substrate 110.

  The plurality of pressure sensors 112 are arranged in a total of 16 in at least 4 rows and 4 columns in two directions (X direction and Y direction) orthogonal to each other. Specifically, a plurality of pressure sensors 112 are arranged in a total of 16 per unit detection area S in at least 4 rows and 4 columns. The center of these 16 pressure sensors 112 (the center of the unit detection region S) is the reference point P.

FIGS. 9A to 9C are cross-sectional views showing changes in pressure values by the pressure sensor according to the second embodiment, corresponding to FIGS. 3A to 3C. FIGS. 10A to 10C are plan views showing changes in the pressure value by the pressure sensor according to the second embodiment, corresponding to FIGS. 4A to 4C.
9A and 10A show a state before external pressure is applied to the surface of the second substrate 20 (when no external pressure is applied). FIG. 9B and FIG. 10B show a state in which a vertical external pressure is applied to the surface of the second substrate 20. FIG. 9C and FIG. 10C show a state where an external pressure in an oblique direction is applied to the surface of the second substrate 20. 10A to 10C, the symbol G indicates the center of gravity (pressure center) of the unit protrusion 24, the symbol G1 indicates the center of gravity of the elastic protrusion 22, and the symbol G2 indicates the center of gravity of the elastic layer 23. . In the following description, the embodiment will be described by taking as an example the case where the unit protrusions 24 are formed so that the respective centers of gravity overlap. In the present invention, the centers of gravity G1 and G2 do not necessarily overlap. 9 and 10, the same elements as those in FIGS. 3 and 4 are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIGS. 9A and 10A, the unit protrusion 24 is not deformed before an external pressure is applied to the surface of the second substrate 20. That is, the elastic protrusion 22 and the elastic layer 23 are not deformed. Thereby, the distance between the first substrate 110 and the second substrate 20 is kept constant. At this time, the center of gravity G of the unit protrusion 24, the center of gravity G1 of the elastic body protrusion 22, and the center of gravity G2 of the elastic body layer 23 are arranged at positions overlapping the reference point P. The pressure value of each pressure sensor 112 at this time is stored in a memory (not shown). The direction and magnitude in which the external pressure acts is obtained based on the pressure value of each pressure sensor 112 stored in the memory.

  FIG. 10A shows a relative position 30 of the base portion of the unit protrusion 24 with respect to the plurality of pressure sensors 112 and the reference point P and a region 40 where the first substrate 110 and the unit protrusion 24 are in contact with each other in a state where no external pressure is applied. Show. In this state, only the elastic body layer 23 is often deformed to come into contact with the first substrate 110. Therefore, in FIG. 10A, the region 40 where the first substrate 110 and the unit protrusion 24 are in contact is equivalent to the region where the first substrate 110 and the elastic layer 23 are in contact. In addition, the position of each center of gravity G, G1, G2 and the position of the reference point P overlap.

As shown in FIGS. 9B and 10B, when the external pressure in the vertical direction is applied to the surface of the second substrate 20, the unit protrusion 24 has the tip portion disposed on the surface of the first substrate 110. It compresses and deforms in the Z direction in contact with the plurality of pressure sensors 112. Due to the external force in the vertical direction, the positions of the centers of gravity G, G1, and G2 remain overlapped and do not shift. As a result, the second substrate 20 bends in the −Z direction, and the distance between the first substrate 110 and the second substrate 20 becomes smaller than when there is no external pressure. The pressure value of the pressure sensor 112 at this time becomes larger than when there is no external pressure. The amount of change is substantially the same for each pressure sensor 112.
According to the present embodiment, the unit protrusion 24 is formed of the elastic protrusion 22 having a high hardness at the center and the elastic layer 23 having a hardness lower than that of the elastic protrusion 22 at the outer periphery. The amount of deformation of the layer 23 increases. Therefore, an effect that the detection sensitivity of the magnitude of the external pressure is improved can be obtained as compared with the case where the unit protrusion 24 is formed of a single material.

  When a vertical external pressure is applied to the surface of the second substrate 20, the unit protrusions 24 are greatly deformed, and not only the elastic layer 23 but also the elastic protrusions 22 pass through the elastic layer 23 to the first substrate 110. To touch. In this state, the relative position 30 of the base of the unit protrusion 24 with respect to the plurality of pressure sensors 112 and the reference point P, the region 40 where the first substrate 110 and the elastic layer 23 are in contact, the first substrate 110 and the elastic protrusion 22 FIG. 10B shows a region 50 that is in contact with each other via the elastic layer 23. The elastic body layer 23 has a lower hardness than the elastic body protrusion 22 and is thus easily deformed, and the region 40 where the first substrate 110 and the elastic body layer 23 are in contact with each other is larger.

  As shown in FIGS. 9C and 10C, when the external pressure in the oblique direction is applied to the surface of the second substrate 20, the unit protrusion 24 has the tip portion disposed on the surface of the first substrate 110. In a state where it is in contact with the plurality of pressure sensors 112, the pressure sensor 112 is inclined and compressed and deformed. As a result, the second substrate 20 bends in the −Z direction, and the distance between the first substrate 110 and the second substrate 20 becomes smaller than when there is no external pressure. At this time, the center of gravity G of the unit protrusion 24 is shifted from the reference point P in the + X direction and the + Y direction. In this case, the overlapping areas of the tip of the unit protrusion 24 and the plurality of pressure sensors 112 are different from each other. Specifically, the area where the tip of the unit protrusion 24 overlaps with the plurality of pressure sensors 112 is + X more than the area where the pressure sensors 112 arranged in the −X direction and the −Y direction among the plurality of pressure sensors 112 overlap. The area overlapping the pressure sensor 112 arranged in the direction and the + Y direction is larger.

The unit protrusion 24 is biased in deformation due to an external pressure in an oblique direction. That is, the center of gravity of the elastic protrusion 22 is displaced from the reference point P and moves in the sliding direction (X direction and Y direction). Then, each pressure sensor 112 detects a different pressure value. Specifically, a relatively large pressure value is detected by the pressure sensor 112 at a position overlapping the gravity center of the elastic protrusion 22, and a relatively small pressure value is detected by the pressure sensor 112 at a position not overlapping with the gravity center of the elastic protrusion 22. Will be detected. And the direction where the external pressure was applied is calculated | required based on the calculation method of the difference mentioned later.
In the present embodiment, the unit protrusion 24 is formed of the elastic protrusion 22 having a high hardness at the center and the elastic layer 23 having a lower hardness than the elastic protrusion 22 at the outer peripheral portion. Is larger than the deformation amount of the elastic protrusion 22. Therefore, the position of each center of gravity is shifted. The position of the center of gravity G of the unit protrusion 24 is obtained by adding the shift of the position of the center of gravity G1 of the elastic body protrusion 22 and the shift of the position of the center of gravity G2 of the elastic body layer 23. Therefore, the effect that the detection sensitivity in the direction of the external pressure is improved can be obtained as compared with the case where the unit protrusion 24 is formed of a single material.

  When the external pressure in the oblique direction is applied to the surface of the second substrate 20, the unit protrusions 24 are greatly deformed, and the base protrusions 24 are in relative contact with each other while the unit protrusions 24 are in contact with the first substrate 110. The position 30 is shifted. FIG. 10C shows that the relative position 30 of the base of the unit protrusion 24 with respect to the pressure sensor 112 and the reference point P is shifted in the direction of the external force. Further, the region 40 where the first substrate 110 and the elastic layer 23 are in contact and the region 50 where the first substrate 110 and the elastic protrusion 22 are in contact with each other through the elastic layer 23 are biased by the external pressure in the oblique direction. It shows that it has occurred. Furthermore, the center of gravity G1 of the elastic protrusion 22, the center of gravity G2 of the elastic body layer 23, and the center of gravity G of the unit protrusion 24 are shifted from the reference point P. Since the elastic body layer 23 has a lower hardness than the elastic body protrusions 22 and is thus easily deformed, the first substrate 110 and the elastic body protrusions 22 are more deformed than the deformation bias of the region 50 in contact with the elastic body layer 23. The bias of deformation of the region 40 where the one substrate 110 and the elastic layer 23 are in contact with each other increases.

FIG. 11 is a diagram showing a coordinate system of the sensing area according to the second embodiment, corresponding to FIG. In FIG. 11, a plurality of pressure sensors S _i (100) are arranged in a matrix, and 25 of these pressure sensors S _i are divided into −X direction and + Y direction, respectively, + X And a region partitioned in the + Y direction, a region partitioned in the −X direction and the −Y direction, and a region partitioned in the + X direction and the −Y direction. Further, in FIG. 11, for convenience, 100 pressure sensors S _i are illustrated, but the number of pressure sensors S _i is not limited to this and can be arbitrarily changed.

As shown in FIG. 11, a plurality of pressure sensors S _i are arranged in a total of 100 per unit detection region S in 10 rows and 10 columns. Here, the pressure value (detected value) detected by each pressure sensor S _i is P _i (i = 1 to 100), and the in-plane direction component of the distance between the reference point P and each pressure sensor S _i is r. _i (i = 1 to 100).
Further, if the X direction component of the in-plane direction component is r _xi (i = 1 to 100), and the Y direction component of the in-plane direction component is r _yi (i = 1 to 100), the X direction component Fx of the external force. (The ratio of the component force acting in the X direction out of the in-plane direction component of the external force) is expressed by the following equation (4).
Further, the Y direction component Fy of the external force (the ratio of the component force acting in the Y direction among the in-plane direction components of the external force) is expressed by the following equation (5).
Further, the Z direction component Fz of the external force (vertical direction component of the external force) is expressed by the following formula (6).

In the present embodiment, the difference between the pressure values of the pressure sensors S _i arbitrarily combined among the pressure values of the 100 pressure sensors S _i that change due to the elastic deformation of the unit protrusion 24 due to the external pressure is calculated, The direction in which the external pressure is applied is calculated based on the difference.

As shown in Expression (4), in the X direction component Fx of the external pressure, the pressure values detected by the pressure sensors S _i arranged relatively in the + X direction among the pressure values detected by the 100 pressure sensors S _i are detected. The values are combined, and the values detected by the pressure sensor S _i arranged relatively in the −X direction are combined. Thus, external pressure on the basis of the difference between the pressure value by a combination of pressure values relatively -X direction arranged pressure sensors S _i by a combination of disposed relatively + X direction pressure sensors S _i An X direction component is obtained.

As shown in the equation (5), in the Y direction component Fy of the external pressure, the values detected by the pressure sensors S _i arranged in the + Y direction are combined among the pressure values of the 100 pressure sensors S _i. At the same time, the values detected by the pressure sensor S _i relatively arranged in the −Y direction are combined. Thus, external pressure on the basis of the difference between the pressure value due to the combination of a relatively + Y pressure is arranged in a direction sensor S _i pressure sensor S _i arranged relatively -Y direction and pressure values of a combination of A Y direction component is obtained.

As shown in Expression (6), the Z direction component Fz of the external pressure is obtained by a resultant force obtained by adding the pressure values detected by the 100 pressure sensors S _i . However, the detected value of the Z direction component Fz of the external pressure tends to be detected larger than the X direction component Fx of the external pressure and the Y direction component Fy (component force) of the external pressure. For example, when a hard material is used as the material of the unit protrusion 24 or the shape of the tip is sharpened, the detection sensitivity of the Z-direction component Fz of the external pressure increases. However, if a hard material is used for the unit protrusion 24, the unit protrusion 24 is not easily deformed, and the detected value in the in-plane direction of the external pressure is reduced. Further, when the shape of the tip of the unit protrusion 24 is sharpened, a strong sensitivity (discomfort) may be given to the touch feeling when the contact surface is touched with a finger. For this reason, in order to align the detected value of the Z direction component Fz of the external pressure with the detected values of the X direction component Fx of the external pressure and the Y direction component Fy of the external pressure, detection is performed with a correction coefficient determined by the material and shape of the unit protrusion 24. It is necessary to correct the value appropriately.

Incidentally, in the calculation of the direction of action of the external pressure, 100 of the pressure sensor S method for determining the average value of the calculation result of the pressure value detected by the in _i or 100 of the pressure sensor S _i in the detected pressure, A method of obtaining a maximum value (for example, a detection value larger than a predetermined threshold value) among the calculation results of values can be used.

  According to the detection device 2 of the present embodiment, since the plurality of pressure sensors 112 are arranged in at least 4 rows and 4 columns in two directions orthogonal to each other, the number of pressure sensors 112 arranged is increased. For this reason, based on the pressure values detected by a large number of pressure sensors 112, the detection results of the pressure sensors 112 can be integrated to determine the direction and magnitude in which the external pressure acts. Therefore, the direction of the external pressure can be detected with high accuracy.

  In the present embodiment, the unit protrusion 24 is formed of the elastic protrusion 22 having a high hardness at the center and the elastic layer 23 having a lower hardness than the elastic protrusion 22 at the outer peripheral portion. Is larger than the deformation amount of the elastic protrusion 22. Therefore, the position of each center of gravity is shifted. The position of the center of gravity G of the unit protrusion 24 is obtained by adding the shift of the position of the center of gravity G1 of the elastic body protrusion 22 and the shift of the position of the center of gravity G2 of the elastic body layer 23. Therefore, compared with the case where the unit protrusion 24 is formed of a single material, an effect that the detection sensitivity in the direction of the external pressure is improved can be obtained. Therefore, it is possible to provide the detection device 2 capable of detecting the direction and magnitude of the external pressure with high accuracy.

(Application examples)
FIG. 12 is an exploded perspective view showing a schematic configuration of the detection apparatus 3 according to the application example of the present invention, corresponding to FIG. In FIG. 12, reference symbol P denotes a reference point, and reference symbol S denotes a unit detection region detected by a plurality of pressure sensors 112 arranged corresponding to one unit protrusion 24. The detection device 3 of this application example has the detection device 2 described in the above-described second embodiment in that a reinforcing member 51 having higher rigidity than the second substrate body 21 is disposed on the surface of the second substrate 20. And different. 12, elements similar to those in FIG. 8 are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 12, the detection device 3 includes a first substrate 110 having a plurality of pressure sensors 112 arranged around the reference point P, a center of gravity located at a position overlapping the reference point P, and a distal end portion due to external pressure. The second substrate 20 on which the unit protrusions 24 that are elastically deformed in contact with the first substrate 110 are formed, and the reinforcement disposed on the side opposite to the side on which the unit protrusions 24 are disposed. The member 51 is provided. In this application example, the unit protrusion 24 is formed by an elastic protrusion 22 having a high hardness at the center and an elastic layer 23 having a lower hardness than the elastic protrusion 22 at the outer periphery.

The reinforcing member 51 has a rectangular plate shape and is formed in the same size as the second substrate body 21 in a plan view. The reinforcing member 51 has higher rigidity than the second substrate body 21. For example, when the material of the second substrate body 21 is a urethane foam resin (durometer hardness of about 30) as in the material of the elastic protrusions 22, an epoxy resin or urethane resin (durometer) is used as a material for forming the reinforcing member 51. Hardness of about 60) can be used. For this reason, even when an external force is applied to the contact surface by an object (for example, a sharp stylus pen) smaller than the arrangement interval of the elastic protrusions 22, the external pressure can be accurately detected.
Furthermore, in this application example, since the elastic body layer 23 having low hardness is formed on the outer peripheral portion of the elastic protrusion 22, the deformation amount of the elastic body layer 23 is larger than the deformation amount of the elastic protrusion 22. Therefore, as described above, the direction of the external pressure can be accurately detected.

  FIGS. 13A to 13C are cross-sectional views showing changes in pressure values by the pressure sensor according to the application example, corresponding to FIGS. 9A to 9C. FIG. 13A shows a state before external pressure is applied to the surface of the second substrate 20 (surface of the reinforcing member 51) (when no external pressure is applied). FIG. 13B shows a state in which a vertical external pressure is applied to the surface of the second substrate 20. FIG. 13C shows a state in which an external pressure in an oblique direction is applied to the surface of the second substrate 20. 13, elements similar to those in FIG. 9 are given the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 13A, the unit protrusion 24 is not deformed before external pressure is applied to the surface of the second substrate 20. Thereby, the distance between the first substrate 110 and the second substrate 20 is kept constant. The pressure value detected by each pressure sensor 112 at this time is stored in a memory (not shown). The direction and magnitude in which the external pressure acts is obtained based on the pressure value detected by each pressure sensor 112 stored in the memory.

  As shown in FIG. 13B, when vertical external pressure is applied to the surface of the second substrate 20, the unit protrusions 24 are compressed in the Z direction with the tips contacting the surface of the second substrate 20. Deform. As a result, the second substrate 20 bends in the −Z direction, and the distance between the first substrate 110 and the second substrate 20 becomes smaller than when there is no external pressure. The pressure value detected by the pressure sensor 112 at this time becomes larger than when there is no external pressure.

  Further, the external pressure acts on a region between two adjacent unit protrusions 24. In this application example, since the reinforcing member 51 having higher rigidity than the second substrate body 21 is provided on the surface of the second substrate 20, for example, when the detection device 3 is pushed in the vertical direction with a finger, two adjacent members are adjacent to each other. The unit protrusions 24 are compressed and deformed in the vertical direction. As described above, it is possible to suppress the two adjacent unit protrusions 24 from being compressed and deformed in opposite directions due to an external force as compared with the case where the reinforcing member 51 is not provided.

  As shown in FIG. 13C, when the external pressure in the oblique direction is applied to the surface of the second substrate 20, the unit protrusion 24 is applied to the plurality of pressure sensors 112 whose tip portions are disposed on the surface of the first substrate 110. In the abutting state, it is inclined and inclined and compressed. As a result, the second substrate 20 bends in the −Z direction, and the distance between the first substrate 110 and the second substrate 20 becomes smaller than when there is no external pressure. Further, the deflection amount of the second substrate 20 is greater in the + X direction component than in the −X direction component. At this time, the center of gravity G of the unit protrusion 24 is shifted from the reference point P in the + X direction and the + Y direction.

  Further, the external pressure acts on a region between two adjacent unit protrusions 24. In this application example, since the reinforcing member 51 having higher rigidity than the second substrate body 21 is provided on the surface of the second substrate 20, for example, when the detection device 3 is pushed obliquely with a finger, two adjacent members are adjacent to each other. The unit protrusions 24 are compressed and deformed in an oblique direction. As described above, it is possible to suppress the two adjacent unit protrusions 24 from being compressed and deformed in opposite directions due to an external force as compared with the case where the reinforcing member 51 is not provided.

  According to the detection device 3 of the present application example, the reinforcing member 51 having higher rigidity than the second substrate body 21 is disposed on the side opposite to the side on which the unit protrusions 24 of the second substrate 20 are formed. The direction of the external pressure can be detected with high accuracy. For example, when the external pressure acts on a region between two adjacent unit protrusions 24, it is possible to suppress the two adjacent unit protrusions 24 from being compressed and deformed in directions opposite to each other as compared with the case where the reinforcing member 51 is not provided. can do. That is, it is possible to suppress erroneous detection such as detecting a direction opposite to the direction in which the external pressure is applied. Therefore, the direction of the external pressure can be detected with high accuracy.

  In this application example, the reinforcing member 51 is disposed on the surface of the second substrate 20, but the present invention is not limited to this. For example, the second substrate body 21 itself may be formed of a material having higher rigidity than the elastic protrusion 22 without providing the reinforcing member 51. Thereby, compared with the structure which provides the reinforcement member 51, thickness reduction of an apparatus can be achieved.

  14A to 14C are cross-sectional views showing three typical structures of the second substrate 20 proposed in the present invention.

  FIG. 14A is a cross-sectional view showing the structure of the second substrate 20 used in the description of the first embodiment and the second embodiment. The unit protrusion 24 includes an elastic body protrusion 22 and an elastic body layer 23 formed on the outer periphery of the elastic body protrusion 22. The elastic body layer 23 is formed of an elastic material having a lower hardness than the elastic body protrusion 22. The shape of the elastic protrusion 22 is described as an example of a hemispherical shape, but may be a cone shape or a column shape.

  FIG. 14B is a structural cross-sectional view showing an embodiment in which the elastic layer 23 is also formed in the region between the elastic protrusions 22 in the structure of FIG. Since the elastic layer 23 can be formed by coating or dipping, effects such as simplification, shortening of the process, or improvement of reliability can be obtained.

  FIG. 14C is a structural cross-sectional view showing an embodiment in which the elastic layer 23 is not formed in the region of the tip of the elastic protrusion 22 in the structure of FIG. That is, the tip of the unit protrusion 24 is made of an elastic material having a higher hardness than the side surface of the unit protrusion 24. With this structure, the amount of deformation of the unit protrusion 24 when an external force in the licking direction is applied to the second substrate 20 is large, so that the detection sensitivity in the direction of the external force is improved.

  FIGS. 15A to 15C are cross-sectional views showing other three types of structures of the second substrate 20 in the present invention. 14 (a) to 14 (c) is a modified embodiment in which the shape of the elastic protrusion 22 is a columnar shape such as a cylinder or a columnar shape. Since the elastic protrusion 22 has a columnar structure as in the present embodiment, the amount of deformation when an external force in the licking direction is applied is larger than the amount of deformation in the case of a hemispherical shape, so the direction of the external force is detected. Sensitivity is improved. Further, the present invention is not limited to the illustrated shape.

(Electronics)
FIG. 16 is a schematic diagram showing a schematic configuration of a mobile phone 1000 to which the detection devices 1 to 3 according to the embodiment are applied. A cellular phone 1000 as an example of an electronic device includes a plurality of operation buttons 1003, a control pad 1002, and a liquid crystal panel 1001 as a display unit. By operating the control pad 1002, the screen displayed on the liquid crystal panel 1001 is scrolled. A menu button (not shown) is displayed on the liquid crystal panel 1001. For example, by placing the cursor (not shown) on the menu button and pressing the control pad 1002 strongly, the phone book is displayed or the phone number of the mobile phone 1000 is displayed.

  FIG. 17 is a schematic diagram showing a schematic configuration of a personal digital assistant (PDA) 2000 to which the detection devices 1 to 3 according to the embodiment are applied. A portable information terminal 2000 as an example of an electronic device includes a plurality of operation buttons 2002, a control pad 2003, and a liquid crystal panel 2001 as a display unit. When the control pad 2003 is operated, a menu displayed on the liquid crystal panel 2001 can be operated. For example, by moving a cursor (not shown) to a menu (not shown) and pressing the control pad 2003 strongly, an address book or a schedule book is displayed.

  According to such an electronic device, since any one of the detection devices 1 to 3 described above is provided in the control pads 1002 and 2003, an electronic device capable of detecting the direction and magnitude of the external pressure with high accuracy is provided. Can be provided.

  Other electronic devices include personal computers, video camera monitors, car navigation devices, pagers, electronic notebooks, calculators, word processors, workstations, videophones, POS terminals, digital still cameras, and touch panels. Equipment and the like. The detection apparatus according to the present invention can also be applied to these electronic devices.

(robot)
FIG. 18 is a schematic diagram showing a schematic configuration of a robot hand 3000 to which the detection devices 1 to 3 according to the embodiment are applied. As shown in FIG. 18A, a robot hand 3000 as an example of a robot includes a main body 3003, a pair of arms 3002, and a grip 3001 to which the detection device is applied. For example, when a drive signal is transmitted to the arm unit 3002 by a control device such as a remote controller, the pair of arm units 3002 open and close.

  As shown in FIG. 18B, consider a case where a robot hand 3000 holds an object 3010 such as a cup. At this time, the force acting on the object 3010 is detected as a pressure by the grip portion 3001. Since the robot hand 3000 includes the detection device described above as the gripping unit 3001, the force in the direction of sliding with gravity Mg (slip force component) in addition to the force in the direction perpendicular to the surface (contact surface) of the object 3010. Can be detected. For example, it can be held while adjusting the force according to the texture of the object 3010 so as not to deform a soft object or drop a slippery object.

  According to such a robot, since any one of the detection devices 1 to 3 described above is provided, a robot capable of detecting the direction of the external pressure with high accuracy can be provided.

1,2,3 ... detector, 10, 110 ... first substrate, 12,112, S1, S2, S3 , S4, S i ... pressure sensor, 20 ... second substrate, 22 ... elastic projection, 23 ... elastic Body layer, 24... Unit protrusion, 30... Relative position of the base of the unit protrusion with respect to the plurality of pressure sensors and reference point P, 40... Region where the first substrate and unit protrusion are in contact, 50. Area in which the protrusion contacts with the elastic layer, 51 ... reinforcing member, 1000 ... mobile phone (electronic device), 2000 ... portable information terminal (electronic device), 3000 ... robot hand (robot), P ... reference point, G ... centroid position of unit protrusion, G1 ... centroid position of elastic body protrusion, G2 ... centroid position of elastic body layer.

Claims (10)

A detection device that detects the direction and magnitude of external pressure applied to a reference point,
A first substrate having a plurality of pressure sensors arranged around the reference point;
A second substrate on which a unit protrusion is formed that has a center of gravity located at a position overlapping with the reference point and elastically deforms in a state where the tip portion is in contact with the first substrate by external pressure;
The unit projection is formed of two or more kinds of elastic materials having different hardnesses. The unit protrusion is
An elastic protrusion made of a first elastic material;
An elastic layer formed so as to cover the elastic protrusion,
The detection device according to claim 1, wherein the elastic layer is made of a second elastic material having a hardness lower than that of the first elastic material. The elastic layer is
The detection device according to claim 1, wherein the detection device is formed on a side surface portion of the elastic protrusion and is not formed on a tip portion of the elastic protrusion.   The unit protrusion is elastically deformed by an external pressure to calculate the difference between the pressure values detected by the pressure sensors arbitrarily combined among the pressure values detected by the plurality of pressure sensors, and based on the difference. The detection device according to claim 1, further comprising an arithmetic device that calculates a direction in which the external pressure is applied and a magnitude of the external pressure.   The detection device according to claim 1, wherein the plurality of pressure sensors are arranged point-symmetrically with respect to the reference point.   The detection device according to any one of claims 1 to 4, wherein the plurality of pressure sensors are arranged in a matrix in two directions orthogonal to each other.   The detection device according to claim 6, wherein the plurality of pressure sensors are arranged in at least 4 rows and 4 columns in two directions orthogonal to each other. A plurality of the unit protrusions are formed on the second substrate;
The detection unit according to claim 1, wherein the plurality of unit protrusions are arranged apart from each other.   An electronic apparatus comprising the detection device according to claim 1.   A robot comprising the detection device according to claim 1.

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