Position detection device

Abstract

In the position detection device, a first end is an end of any one of a third direction and an opposite direction of the third direction of first to m-th row sensors when viewed along a first direction, and a second end is an end of any one of a second direction and an opposite direction of the second direction of first to n-th row sensors when viewed along the first direction. Each of the first to m-th row sensors includes a piezoelectric first piezoelectric film that is uniaxially stretched and has molecules oriented in a first orientation direction, and is disposed such that the first orientation direction is parallel to the third direction. Each of the first to n-th row sensors includes a piezoelectric second piezoelectric film that is uniaxially stretched and has molecules oriented in a second orientation direction, and is disposed such that the second orientation direction is parallel to the second direction.

Description

Technical Field

[0001] The present invention relates to a position detection device including a sensor for detecting deformation of a member. Background Art

[0002] Patent document 1 describes a position detection device. The position detection device includes a protective layer, strip electrodes, a piezoelectric body, a single electrode, and an operational circuit. The piezoelectric body is located between the strip electrodes and the single electrode. When viewed along the direction in which the protective layer, the strip electrodes, the piezoelectric body, and the single electrode are arranged, the piezoelectric body overlaps the entire surface of the protective layer. The user presses the protective layer. As a result, the protective layer deforms. As the protective layer deforms, the piezoelectric body deforms. At this time, a voltage is generated between the strip electrodes and the single electrode. The operational circuit determines the position of the protective layer touched by the user based on the generated voltage.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2011-210081 Summary of the Invention

[0006] Problems to be solved by the invention

[0007] In the field of the position detection device described in Patent Document 1, there is a desire to reduce the cost of the position detection device.

[0008] An object of the present invention is to provide a position detection device that can be easily reduced in cost.

[0009] Solutions for solving problems

[0010] A position detection device according to one embodiment of the present invention includes:

[0011] an elastic member having a first main surface and a second main surface arranged along a first direction; and

[0012] Multiple sensors,

[0013] The plurality of sensors are each provided on the first main surface or the second main surface,

[0014] The plurality of sensors include:

[0015] The first to m-th row sensors have first ends overlapping with an outer edge of the first main surface or the second main surface; and

[0016] The first to nth row sensors have second ends overlapping with the outer edge of the first main surface or the second main surface,

[0017] The m and n are each a natural number,

[0018] The third direction intersects the second direction,

[0019] The first end is an end of the first to m-th row of sensors in either the third direction or a direction opposite to the third direction when viewed along the first direction.

[0020] The second end is an end of the first to n-th rows of sensors in either the second direction or a direction opposite to the second direction when viewed along the first direction.

[0021] The positions of the sensors in the first row to the mth row in the second direction are arranged in sequence along the second direction.

[0022] The positions of the first to nth row of sensors in the third direction are arranged in sequence along the third direction.

[0023] The first to m-th row sensors each include a first piezoelectric film having piezoelectricity in which molecules are oriented along a first orientation direction under uniaxial stretching, and are arranged so that the first orientation direction is parallel to the third direction.

[0024] Each of the first to n-th row sensors includes a second piezoelectric film having piezoelectricity in which molecules are oriented along a second orientation direction under uniaxial stretching, and is arranged so that the second orientation direction is parallel to the second direction.

[0025] Effects of the Invention

[0026] According to the position detection device of the present invention, it is possible to provide a position detection device that can be easily reduced in cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a perspective view of the position detection device 1 according to the first embodiment.

[0028] Figure 2 This is a diagram showing the position detection device 1 as viewed in the negative direction of the Z axis.

[0029] Figure 3 yes Figure 1 AA cross-sectional view.

[0030] Figure 4 1 is a diagram showing an example of the first signal Sig1 output by the first line sensor 11 a when the first region Ar1 located on the negative side of the X axis with respect to the first line sensor 11 a on the first main surface UF10 is deformed.

[0031] Figure 51 is a diagram showing an example of the first signal Sig1 output by the first line sensor 11 a when the second region Ar2 located on the positive side of the X axis relative to the first line sensor 11 a on the first main surface UF10 is deformed.

[0032] Figure 6 1 is a flowchart showing an example of the processing U performed by the arithmetic circuit 13 .

[0033] Figure 7 This is a diagram showing a position detection device 1 a according to a first modification of the position detection device 1 .

[0034] Figure 8 This is a diagram showing a position detection device 1 b according to a second modification of the position detection device 1 .

[0035] Figure 9 This is a diagram showing a position detection device 1 c according to a third modification of the position detection device 1 .

[0036] Figure 10 This is a diagram showing a position detection device 1 d according to a fourth modification of the position detection device 1 .

[0037] Figure 11 This is a diagram showing a position detection device 1 e according to a fifth modification of the position detection device 1 .

[0038] Figure 12 This is a graph showing experimental results Re1 obtained through experiments conducted by the inventors of the present application.

[0039] Figure 13 This is a graph showing experimental results Re2 obtained through experiments by the inventors of the present application.

[0040] Figure 14 This is a graph showing experimental results Re3 obtained through experiments by the inventors of the present application. DETAILED DESCRIPTION

[0041] [First embodiment]

[0042] Hereinafter, a position detection device 1 according to a first embodiment of the present invention will be described with reference to the drawings. Figure 1 It is a perspective view of the position detection device 1 according to the first embodiment. Figure 2 This is a diagram showing the position detection device 1 as viewed in the negative direction of the Z axis. Figure 3 yes Figure 1 AA cross-sectional view.

[0043] In this embodiment, directions are defined as follows. Figure 1As shown, the direction in which the multiple sensors 11 and the elastic member 10 are arranged is defined as the Z-axis direction. The direction in which the multiple sensors 11 and the elastic member 10 are arranged in sequence is defined as the negative direction of the Z-axis. The direction in which the elastic member 10 and the multiple sensors 11 are arranged in sequence is defined as the positive direction of the Z-axis. The direction perpendicular to the Z-axis direction is defined as the X-axis direction. The direction perpendicular to the Z-axis direction and the X-axis direction is defined as the Y-axis direction. In addition, the first direction DIR1 coincides with the negative direction of the Z-axis. The second direction DIR2 coincides with the positive direction of the X-axis. The third direction DIR3 coincides with the positive direction of the Y-axis. The third direction DIR3 intersects with the second direction DIR2. The fourth direction DIR4 coincides with the negative direction of the X-axis. The fourth direction DIR4 is the opposite direction of the second direction DIR2. The fifth direction DIR5 coincides with the negative direction of the Y-axis. The fifth direction DIR5 is the opposite direction of the third direction DIR3.

[0044] In this embodiment, the position detection device 1 is a device provided in an electronic device such as a smartphone. Figure 1 and Figure 2 As shown, the position detection device 1 includes an elastic member 10 , a plurality of sensors 11 , and an operation circuit 13 .

[0045] like Figure 1 and Figure 2 As shown, the elastic member 10 has a rectangular shape, including a first side H1 and a second side H2, which are long sides extending along the X-axis, and a third side H3 and a fourth side H4, which are short sides extending along the Y-axis. The first side H1 is located on the positive side of the Y-axis relative to the second side H2. The third side H3 is located on the negative side of the X-axis relative to the fourth side H4. The elastic member 10 has a first principal surface UF10 and a second principal surface DF10, which are aligned along a first direction DIR1. The first principal surface UF10 and the second principal surface DF10 are aligned in the negative direction of the Z-axis. The outer edge of the first principal surface UF10 includes the first side H1, the second side H2, the third side H3, and the fourth side H4. The elastic member 10 is elastic. Therefore, the elastic member 10 deforms under the influence of an external force applied to the elastic member 10. For example, a user presses the second principal surface DF10 of the elastic member 10 in the positive direction of the Z-axis. The elastic member 10 is deformed by a force applied to the elastic member 10 in the positive direction of the Z axis.

[0046] In this embodiment, the plurality of sensors 11 include a plurality of sensors that are in contact with the outer edge of the elastic member 10 when viewed along the Z-axis direction. Figure 1 and Figure 2 As shown, the plurality of sensors 11 include sensors in the first row to sensors in the mth row and sensors in the first column to sensors in the nth column.

[0047] The first row of sensors to the mth row of sensors are one or more sensors arranged along the second direction DIR2. Specifically, the positions of the first row of sensors to the mth row of sensors in the second direction DIR2 are arranged in sequence along the second direction DIR2. m is a natural number. In this embodiment, m is 1. Therefore, in this embodiment, Figure 1 and Figure 2 As shown, the plurality of sensors 11 include a first row of sensors 11 a .

[0048] like Figure 2 As shown, the first row sensor 11a has the following rectangular shape: a long side extending along the Y axis and a short side extending along the X axis. The first row sensor 11a is provided on the first main surface UF10. In the present embodiment, when viewed along the Z axis direction, a portion of the outer edge of the first row sensor 11a overlaps with the outer edge of the first main surface UF10. Specifically, in the present embodiment, the first row sensor 11a has an end E11a (first end). The end E11a is the end of the first row sensor 11a in the third direction DIR3 when viewed along the first direction DIR1. When viewed along the first direction DIR1, the end E11a overlaps with the outer edge of the first main surface UF10. When viewed along the Z axis direction, the end E11a overlaps with the first side H1 of the first main surface UF10. As shown Figure 3 As shown, the first row sensor 11 a includes a first electrode 110 a , a piezoelectric film 111 a (first piezoelectric film), a second electrode 112 a , and a detection circuit (not shown).

[0049] like Figure 2 and Figure 3 As shown in FIG. 1 , the piezoelectric film 111 a has a sheet shape having short sides extending along the X axis and long sides extending along the Y axis. Figure 3 As shown, the piezoelectric film 111 a includes a piezoelectric film first principal surface SF1 and a piezoelectric film second principal surface SF2 arranged along the Z-axis direction.

[0050] The piezoelectric film 111a generates electric charge corresponding to the amount of deformation of the piezoelectric film 111a. Figure 2 In the example shown, the polarity of the charge generated when the piezoelectric film 111a is stretched in the negative direction of the X-axis and the negative direction of the Y-axis is opposite to the polarity of the charge generated when the piezoelectric film 111a is stretched in the negative direction of the X-axis and the positive direction of the Y-axis. Specifically, the piezoelectric film 111a is a film formed by a chiral polymer. The chiral polymer is, for example, polylactic acid (PLA), in particular, L-type polylactic acid (PLLA). The main chain of PLLA formed by the chiral polymer has a helical structure. PLLA has piezoelectricity due to uniaxial stretching and molecular orientation. The piezoelectric film 111a has a piezoelectric constant of d14. As Figure 2As shown, the piezoelectric film 111a (first piezoelectric film) has piezoelectricity in which the molecules are oriented along the orientation direction OD1a (first orientation direction) under uniaxial stretching. In this embodiment, the first row sensor 11a is configured so that the orientation direction OD1a is parallel to the third direction DIR3. The orientation direction OD1a forms an angle of 0 degrees with respect to the Y-axis direction. This 0 degree includes, for example, the following angles: approximately 0 degrees ± 10 degrees. For example, the piezoelectric film 111a generates a positive charge when stretched in the negative direction of the X-axis and in the negative direction of the Y-axis. For example, the piezoelectric film 111a generates a negative charge when stretched in the positive direction of the X-axis and in the negative direction of the Y-axis. For example, the piezoelectric film 111a generates a negative charge when compressed in the negative direction of the X-axis and in the negative direction of the Y-axis. For example, the piezoelectric film 111a generates a positive charge when compressed in the positive direction of the X-axis and in the negative direction of the Y-axis. The magnitude of the generated charge depends on the differential value of the deformation amount of the piezoelectric film 111 a caused by extension or compression.

[0051] The first electrode 110a is, for example, a reference electrode connected to a reference potential. Figure 3 As shown, the first electrode 110a is fixed to the first main surface SF1 of the piezoelectric film using an adhesive (not shown) such as OCA. The first electrode 110a covers the first main surface SF1 of the piezoelectric film.

[0052] The second electrode 112a is, for example, a signal electrode. Figure 3 As shown, the second electrode 112a is fixed to the second main surface SF2 of the piezoelectric film using an adhesive material (not shown) such as OCA. The second electrode 112a covers the second main surface SF2 of the piezoelectric film.

[0053] The detection circuit converts the charge generated by the piezoelectric film 111 a into a voltage signal and performs A / D conversion on the voltage signal to generate a digital signal.

[0054] According to the above configuration, the polarity of the signal outputted by the first line sensor 11a (hereinafter referred to as the first signal Sig1) changes according to the position at which the elastic member 10 is pressed. This will be described below with reference to the drawings. Figure 4 1 is a diagram showing an example of the first signal Sig1 output by the first line sensor 11 a when the first region Ar1 located on the negative side of the X axis with respect to the first line sensor 11 a on the first main surface UF10 is deformed. Figure 5This diagram illustrates an example of the first signal Sig1 output by the first row sensor 11a when the second area Ar2, located on the first main surface UF10 and located on the positive side of the X-axis relative to the first row sensor 11a, is deformed. Specifically, the first area Ar1 and the second area Ar2 are the areas shown below. A straight line SL1 (first straight line) parallel to the third direction DIR3 is defined. When viewed along the first direction DIR1, the straight line SL1 overlaps with the first row sensor 11a. The first area Ar1 is located on the negative side of the X-axis relative to the straight line SL1. The second area Ar2 is located on the positive side of the X-axis relative to the straight line SL1.

[0055] The polarity of the first signal Sig1 output by the first row sensor 11a when the first area Ar1 is pressed is different from the polarity of the first signal Sig1 output by the first row sensor 11a when the second area Ar2 is pressed. Figure 4 At time t1 shown in FIG. 1 , the user presses the first area Ar1. In this case, the piezoelectric film 111a stretches in the negative direction of the X axis and in the negative direction of the Y axis. At this time, the piezoelectric film 111a outputs positive charge. Therefore, Figure 4 As shown, the first row sensor 11a outputs the first signal Sig1 having a positive polarity relative to the reference potential VE between time t1 and time t2 which is later than time t1. Then, at time t2, the user stops pressing the first area Ar1. The first row sensor 11a is about to return to its shape before deformation due to the restoring force generated by the first row sensor 11a. Under the action of this restoring force, the piezoelectric film 111a is compressed in the negative direction of the X axis and in the negative direction of the Y axis. In this case, the piezoelectric film 111a outputs a negative charge. Therefore, as Figure 4 As shown, the first row sensor 11a outputs the first signal Sig1 having a positive polarity with respect to the reference potential VE at time t3 which is later than time t2. As a result, in one cycle from the start to the end of the user pressing the first area Ar1, the first row sensor 11a outputs the first signal Sig1 having a positive polarity with respect to the reference potential VE and then outputs the first signal Sig1 having a negative polarity with respect to the reference potential VE.

[0056] On the other hand, Figure 5 At the time s1 shown, the user presses the second area Ar2. In this case, the piezoelectric film 111a stretches in the positive direction of the X axis and in the negative direction of the Y axis. At this time, the piezoelectric film 111a outputs negative charge. Therefore, Figure 5As shown, the first-row sensor 11a outputs a first signal Sig1 having a negative polarity relative to the reference potential VE between time s1 and time s2, which is later than time s1. Then, at time s2, the user stops pressing the second area Ar2. The first-row sensor 11a is compressed in the positive direction of the X-axis and in the negative direction of the Y-axis by the restoring force generated by the first-row sensor 11a. In this case, at time s3, which is later than time s2, the first-row sensor 11a outputs a first signal Sig1 having a positive polarity relative to the reference potential VE. As a result, in one cycle from the start to the end of the user's pressing of the second area Ar, the first-row sensor 11a outputs a first signal Sig1 having a negative polarity relative to the reference potential VE, followed by a first signal Sig1 having a positive polarity relative to the reference potential VE.

[0057] The first to nth row sensors are one or more sensors arranged along the third direction DIR3. Specifically, the positions of the first to nth row sensors in the third direction DIR3 are arranged in sequence along the third direction DIR3. n is a natural number. In this embodiment, n is a natural number greater than 2. Figure 1 and Figure 2 In the example shown, n is 2. Therefore, in this embodiment, the plurality of sensors 11 include a first row of sensors 12a and a second row of sensors 12b. The first row of sensors 12a and the second row of sensors 12b are sequentially arranged at intervals in the negative direction of the Y axis.

[0058] like Figure 2 As shown, the first row of sensors 12a has the following rectangular shape: a long side extending along the X axis and a short side extending along the Y axis. The first row of sensors 12a is provided on the first main surface UF10. In this embodiment, the first row of sensors 12a has an end E12a (second end). When viewed along the first direction DIR1, the end E12a is the end of the first row of sensors 12a in the second direction DIR2. When viewed along the first direction DIR1, the end E12a overlaps with the outer edge of the first main surface UF10. Figure 2 As shown, end E12a overlaps with fourth side H4 of first principal surface UF10 when viewed along the Z-axis. The first row of sensors 12a includes a piezoelectric film 121a (second piezoelectric film). The piezoelectric film 121a exhibits piezoelectric properties, whereby molecules are oriented along orientation direction OD2a (second orientation direction) under uniaxial stretching. The first row of sensors 12a is arranged so that orientation direction OD2a is parallel to second direction DIR2. The remaining structure of the first row of sensors 12a is identical to that of the first row of sensors 11a, and therefore, description thereof will be omitted.

[0059] According to the above structure, similarly to the first row sensor 11a, the polarity of the signal (hereinafter referred to as the second signal) output by the first column sensor 12a changes according to the position where the elastic member 10 is pressed. Specifically, Figure 2 As shown, a straight line SL2 (second straight line) parallel to the second direction DIR2 is defined. When viewed along the first direction DIR1, the straight line SL2 overlaps with the first row of sensors 12a. In the first main surface UF10, an area located on the positive side of the Y axis relative to the straight line SL2 is defined as the third area Ar3. In the first main surface UF10, an area located on the negative side of the Y axis relative to the straight line SL2 is defined as the fourth area Ar4. For example, in a cycle from the start of pressing the third area Ar3 to the end of pressing the third area Ar3, the first row of sensors 12a outputs a second signal having a positive polarity relative to the reference potential VE, followed by a second signal having a negative polarity relative to the reference potential VE. For example, in a cycle from the start of pressing the fourth area Ar4 to the end of pressing the fourth area Ar4, the first row of sensors 12a outputs a second signal having a negative polarity relative to the reference potential VE, followed by a second signal having a positive polarity relative to the reference potential VE.

[0060] like Figure 2 As shown, the second row of sensors 12b is provided on the first main surface UF10. In the present embodiment, the second row of sensors 12b has an end E12b (second end). End E12b is the end of the second row of sensors 12b in the second direction DIR2 when viewed along the first direction DIR1. When viewed along the first direction DIR1, end E12b overlaps with the outer edge of the first main surface UF10. In the present embodiment, end E12b overlaps with the fourth side H4. The second row of sensors 12b includes a piezoelectric film 121b (second piezoelectric film). The piezoelectric film 121b has piezoelectric properties in which molecules are oriented along an orientation direction OD2b (second orientation direction) under uniaxial stretching. The second row of sensors 12b is configured so that the orientation direction OD2b is parallel to the second direction DIR2. The other structures of the second row of sensors 12b are the same as those of the first row of sensors 12a, and therefore description thereof is omitted.

[0061] According to the above structure, similarly to the first row sensor 12a, the polarity of the signal output by the second row sensor 12b (hereinafter referred to as the third signal) changes according to the position where the elastic member 10 is pressed. Figure 2As shown, a straight line SL3 (second straight line) parallel to the second direction DIR2 is defined. When viewed along the first direction DIR1, the straight line SL3 overlaps with the second row of sensors 12b. In the first main surface UF10, the area located on the positive side of the Y axis relative to the straight line SL3 is defined as the fifth area Ar5. In the first main surface UF10, the area located on the negative side of the Y axis relative to the straight line SL3 is defined as the sixth area Ar6. For example, in a cycle from the start of pressing the fifth area Ar5 to the end of pressing the fifth area Ar5, the second row of sensors 12b outputs a third signal having a positive polarity relative to the reference potential VE, followed by a third signal having a negative polarity relative to the reference potential VE. For example, in a cycle from the start of pressing the sixth area Ar6 to the end of pressing the sixth area Ar6, the second row of sensors 12b outputs a third signal having a negative polarity relative to the reference potential VE, followed by a third signal having a positive polarity relative to the reference potential VE.

[0062] The arithmetic circuit 13 is, for example, a microcontroller including a CPU, ROM, and RAM. The arithmetic circuit 13 receives the first signal Sig1 output by the first row sensor 11a, the second signal output by the first column sensor 12a, and the third signal output by the second column sensor 12b. The arithmetic circuit 13 performs a process (hereinafter referred to as process U) to determine the position at which the elastic member 10 is deformed based on the first signal Sig1, the second signal, and the third signal. Process U will be described below with reference to the accompanying drawings. Figure 6 1 is a flowchart showing an example of the processing U performed by the arithmetic circuit 13 .

[0063] For example, when the arithmetic circuit 13 receives the first signal Sig1, the second signal, and the third signal, it starts processing U( Figure 6 : Start). After the start, the operation circuit 13 determines the polarity of the first signal Sig1 relative to the reference potential VE (hereinafter referred to as the first polarity), the polarity of the second signal relative to the reference potential VE (hereinafter referred to as the second polarity), and the polarity of the third signal relative to the reference potential VE (hereinafter referred to as the third polarity) ( Figure 6 :Step S11).

[0064] Next, the calculation circuit 13 determines the position where the elastic member 10 is deformed based on the first polarity, the second polarity, and the third polarity ( Figure 6 :Step S12). Next, the user presses Figure 2 The case of the region ArID shown in FIG. 1 is described as an example. The region ArID is a region located on the negative side of the X axis with respect to the straight line SL1 on the first main surface UF10 and located between the straight lines SL2 and SL3 .

[0065] In this case, the first row sensor 11a outputs the first signal Sig1 having a positive polarity with respect to the reference potential VE, followed by the first signal Sig1 having a negative polarity with respect to the reference potential VE. Therefore, when the arithmetic circuit 13 receives the first signal Sig1 having a negative polarity with respect to the reference potential VE, followed by the first signal Sig1 having a positive polarity with respect to the reference potential VE, it determines that the area pressed by the user on the first main surface UF10 is within the first area Ar1.

[0066] Similarly, the first column sensor 12a outputs a second signal having a positive polarity relative to the reference potential VE after outputting a second signal having a negative polarity relative to the reference potential VE. Therefore, when the arithmetic circuit 13 receives a second signal having a positive polarity relative to the reference potential VE after receiving a second signal having a negative polarity relative to the reference potential VE, it determines that the area pressed by the user on the first main surface UF10 is within the fourth area Ar4.

[0067] Similarly, the second row sensor 12 b outputs a third signal having a negative polarity relative to the reference potential VE after outputting the third signal having a positive polarity relative to the reference potential VE. Therefore, when the arithmetic circuit 13 receives a third signal having a negative polarity relative to the reference potential VE after receiving the third signal having a positive polarity relative to the reference potential VE, it determines that the area pressed by the user on the first main surface UF10 is within the fifth area Ar5.

[0068] In the above case, the arithmetic circuit 13 determines that the area pressed by the user on the first main surface UF10 satisfies the conditions of being located within the first area Ar1, within the fourth area Ar4, and within the fifth area Ar5. Since the area ArID satisfies this condition, the arithmetic circuit 13 identifies the area ArID satisfying this condition as the area pressed by the user.

[0069] By executing the processing of step S11 and step S12, the operation circuit 13 completes the processing U( Figure 6 :Finish).

[0070] (Effect)

[0071] According to the position detection device 1, it is easy to reduce the cost of the position detection device 1. The position detection device described in patent document 1 and the position detection device 1 are compared and explained below. In the position detection device described in patent document 1, the operation circuit determines the position touched by the user in the protective layer based on the voltage generated by the piezoelectric body. In this case, it is necessary for the piezoelectric body to overlap with the entire surface of the protective layer when viewed along the direction of the arrangement of the protective layer, the strip electrodes, the piezoelectric body, and the single electrode. Therefore, in order to determine the position touched by the user in the protective layer, the position detection device described in patent document 1 needs to include a piezoelectric body of the same size as the entire surface of the protective layer. Therefore, in the position detection device described in patent document 1, it is difficult to reduce the size of the piezoelectric body. Therefore, it is difficult to reduce the cost of the position detection device described in patent document 1.

[0072] On the other hand, the position detection device 1 includes: a first row sensor 11a having an end E11a overlapping with the outer edge of the first main surface UF10; a first column sensor 12a having an end E12a overlapping with the outer edge of the first main surface UF10; and a second column sensor 12b having an end E12b overlapping with the outer edge of the first main surface UF10. The orientation direction OD1a of the first row sensor 11a is parallel to the third direction DIR3. The orientation direction OD2a of the first column sensor 12a is parallel to the second direction DIR2. The orientation direction OD2b of the second column sensor 12b is parallel to the second direction DIR2. In this case, as Figure 2 As shown, the position detection device 1 can determine which of the first to sixth regions Ar1 to Ar6 is deformed. Therefore, the position detection device 1 can determine the location of deformation in the elastic member 10 even without including sensors disposed on the entire surface of the elastic member 10. Consequently, compared to the position detection device of Comparative Example 1, the sensor area can be easily reduced, facilitating cost reduction in the position detection device 1.

[0073] [Variation 1]

[0074] Hereinafter, a position detection device 1 a according to a first modification will be described with reference to the drawings. Figure 7 This figure shows a position detection device 1a according to a first modification of the position detection device 1. In the configuration of the position detection device 1a, only portions that differ from those of the position detection device 1 will be described, and description of portions that are identical to those of the position detection device 1 will be omitted.

[0075] like Figure 7 As shown in FIG, in the position detection device 1a, the plurality of sensors 11 are each provided on the second main surface DF10. Such a position detection device 1a achieves the same effects as the position detection device 1.

[0076] [Variation 2]

[0077] Hereinafter, a position detection device 1 b according to a second modification will be described with reference to the drawings. Figure 8 This is a diagram showing a position detection device 1 b according to a second modification of the position detection device 1 .

[0078] like Figure 8 As shown, position detection device 1b differs from position detection device 1 in that it further includes sensor 14a that does not overlap with the outer edge of first main surface UF10. Therefore, in this modification, multiple sensors 11 further include sensor 14a (first sensor).

[0079] Sensor 14a includes a piezoelectric film 141a (third piezoelectric film). Piezoelectric film 141a exhibits piezoelectric properties, resulting in molecular alignment along orientation direction OD4a (third orientation direction) under uniaxial stretching. Sensor 14a is positioned so that orientation direction OD4a is parallel to third direction DIR3. When viewed along first direction DIR1, sensor 14a overlaps with line SL1 (first line).

[0080] In this modification, the sensor 14a is located between two adjacent sensors in the first to nth rows of sensors when viewed along the second direction DIR2. In this modification, n is 2. Therefore, the plurality of sensors 11 includes the adjacent first row of sensors 12a and second row of sensors 12b. Therefore, the sensor 14a is located between the first row of sensors 12a and second row of sensors 12b when viewed along the second direction DIR2. In this modification, as shown in FIG. Figure 8 As shown, the sensor 14a is located between the straight line SL2 and the straight line SL3 when viewed along the Z-axis direction.

[0081] The calculation circuit 13 specifies the position where the elastic member 10 is deformed based on the first signal Sig1 , the second signal, and the third signal, and also specifies the position where the elastic member 10 is deformed based on the fourth signal output by the sensor 14 a .

[0082] (Effect)

[0083] For example, when the end of the first region Ar1 in the negative direction of the Y axis is deformed, sensor 14a is more likely to deform than first-row sensor 11a. Consequently, the fourth signal output by sensor 14a is more likely to be larger than the first signal Sig1. Consequently, the calculation circuit 13 determines the position of deformation of the elastic member 10 based on the first signal Sig1 and the fourth signal, making it easier to determine the deformation of the end of the first region Ar1 in the negative direction of the Y axis. Consequently, the position detection device 1a makes it easier for the calculation circuit 13 to determine the position of deformation in the elastic member 10.

[0084] [Variation 3]

[0085] Hereinafter, a position detection device 1 c according to a third modification will be described with reference to the drawings. Figure 9 This is a diagram showing a position detection device 1 c according to a third modification of the position detection device 1 .

[0086] The position detection device 1c is different from the position detection device 1 in that it includes a sensor where m is a natural number greater than or equal to 2. Figure 9 In the example shown, m is 2. Therefore, in this modification, the plurality of sensors 11 further include a second-row sensor 11b. The second-row sensor 11b is located on the negative side of the X axis with respect to the first-row sensor 11a.

[0087] The second line sensor 11b includes a piezoelectric film 111b (first piezoelectric film). The piezoelectric film 111b has piezoelectric properties such that molecules are oriented along the orientation direction OD1b (first orientation direction) under uniaxial stretching. The second line sensor 11b is arranged so that the orientation direction OD1b is parallel to the third direction DIR3.

[0088] Here, a straight line SL4 is defined that is parallel to the third direction DIR3 and overlaps with the second-line sensor 11b when viewed along the Z-axis direction (first direction DIR1). In this case, the polarity of the signal output by the second-line sensor 11b when the area on the first principal surface UF10 located on the negative side of the X-axis relative to the straight line SL4 is deformed differs from the polarity of the signal output by the second-line sensor 11b when the area on the first principal surface UF10 located on the positive side of the X-axis relative to the straight line SL4 is deformed. The remaining structure of the second-line sensor 11b is identical to that of the first-line sensor 11a, and therefore, description thereof will be omitted.

[0089] The position detection device 1c is different from the position detection device 1 in that it further includes a sensor 15a (second sensor) that does not overlap with the outer edge of the first main surface UF10 (see FIG. 1 ). Figure 9 ). Therefore, in this modification, the plurality of sensors 11 further include a sensor 15a (second sensor).

[0090] Sensor 15a includes a piezoelectric film 151a (fourth piezoelectric film). Piezoelectric film 151a exhibits piezoelectric properties, resulting in molecular alignment along orientation direction OD5a (fourth orientation direction) under uniaxial stretching. Sensor 15a is positioned so that orientation direction OD5a is parallel to second direction DIR2. In this variation, sensor 15a overlaps with line SL2 (second line) when viewed along first direction DIR1.

[0091] In this variation, sensor 15a is located between two adjacent sensors in the first to m-th rows of sensors when viewed along the third direction DIR3. In this variation, the plurality of sensors 11 includes adjacent sensors 11a in the first row and sensors 11b in the second row. Therefore, sensor 15a is located between sensors 11a in the first row and sensors 11b in the second row when viewed along the third direction DIR3. The remaining structure of sensor 15a is identical to that of sensor 12a in the first column, and therefore its description is omitted.

[0092] In this modification, the calculation circuit 13 determines the deformed position of the elastic member 10 based on the signal output from the second row sensor 11b and the signal output from the sensor 15a in addition to the first signal Sig1, the second signal, and the third signal.

[0093] (Effect)

[0094] In the position detection device 1, the first main surface UF10 is divided into six regions by the first straight line SL1, the second straight line SL2, and the third straight line SL3. Here, the position detection device 1c includes, in addition to the first row sensor 11a, the first column sensor 12a, and the second column sensor 12b, a second row sensor 11b. In this case, the first main surface UF10 is divided into nine regions by a plurality of straight lines. That is, compared to the position detection device 1, in the position detection device 1c, the region of the first main surface UF10 where deformation is determined by the calculation circuit 13 is further subdivided. As a result, the accuracy of determining the position of the elastic member 10 deformed by the calculation circuit 13 is improved.

[0095] For example, when the end of the third region Ar3 in the negative direction of the X-axis is deformed, sensor 15a is more likely to deform than sensor 12b in the second row. Consequently, the magnitude of the signal output by sensor 15a is likely to be larger than the magnitude of the second signal. Consequently, the calculation circuit 13 determines the position of deformation of the elastic member 10 based on the second signal and the signal output by sensor 15a, making it easier to determine the deformation of the end of the third region Ar3 in the negative direction of the X-axis. Consequently, the position detection device 1c makes it easier for the calculation circuit 13 to determine the position of deformation in the elastic member 10.

[0096] The position detection device 1c further includes a sensor 15a. The sensor 15a is located between two adjacent sensors in the first row to the mth row of sensors when viewed along the third direction DIR3. In this case, Figure 9As shown, sensor 15a is positioned near the center of first principal surface UF10 relative to the sensors in the 1st to mth rows and the sensors in the 1st to nth columns. Therefore, sensor 15a is more likely to detect deformation near the center of first principal surface UF10 than the sensors in the 1st to mth rows and the sensors in the 1st to nth columns. Consequently, position detection device 1c allows calculation circuit 13 to more easily determine the position of deformation of elastic member 10.

[0097] [Variation 4]

[0098] Hereinafter, a position detection device 1d according to a fourth modification will be described with reference to the drawings. Figure 10 This is a diagram showing a position detection device 1 d according to a fourth modification of the position detection device 1 .

[0099] like Figure 10 As shown, the position detection device 1d differs from the position detection device 1 in that it includes a second row of sensors 11b and a third row of sensors 11c in addition to the first row of sensors 11a. The positions of the first row of sensors 11a, the second row of sensors 11b, and the third row of sensors 11c in the second direction DIR2 are arranged in this order.

[0100] In this modified example, when viewed along the first direction DIR1, the ends (first ends) of some of the sensors in the first to m-th row of sensors in the third direction DIR3 overlap with the outer edge of the first main surface UF10. Furthermore, when viewed along the first direction DIR1, the ends (first ends) of the remaining sensors in the first to m-th row of sensors in the fifth direction DIR5 overlap with the outer edge of the first main surface UF10. For example, Figure 10 As shown, when viewed along the first direction DIR1, end E11a of the first row of sensors 11a (part of the sensors in the first to m-th rows) in the third direction DIR3 overlaps with the first side H1. When viewed along the first direction DIR1, end E11b of the second row of sensors 11b (the remaining sensors in the first to m-th rows) in the fifth direction DIR5 overlaps with the second side H2. When viewed along the first direction DIR1, end E11c of the third row of sensors 11c (the remaining sensors in the first to m-th rows) in the fifth direction DIR5 overlaps with the second side H2. The remaining structure of the second row of sensors 11b is the same as that of the first row of sensors 11a, and therefore its description is omitted. The remaining structure of the third row of sensors 11c is the same as that of the first row of sensors 11a, and therefore its description is omitted.

[0101] Furthermore, the position detection device 1d differs from the position detection device 1 in that it includes a third row of sensors 12c in addition to the first row of sensors 12a and the second row of sensors 12b. The positions of the first row of sensors 12a, the second row of sensors 12b, and the third row of sensors 12c in the third direction DIR3 are arranged in this order along the third direction DIR3.

[0102] In this modified example, when viewed along the first direction DIR1, the ends (second ends) of the sensors in the first to n-th columns of sensors in the second direction DIR2 overlap with the outer edge of the first main surface UF10. Furthermore, when viewed along the first direction DIR1, the ends (second ends) of the sensors in the fourth direction DIR4 overlap with the outer edge of the first main surface UF10 of the remaining sensors in the first to n-th columns of sensors. For example, Figure 10 As shown, when viewed along the first direction DIR1, end E12a of the first row of sensors 12a (the sensors from the first row through the nth row) in the second direction DIR2 and end E12b of the second row of sensors 12b (the sensors from the first row through the nth row) in the second direction DIR2 overlap with the fourth side H4. When viewed along the first direction DIR1, end E12c of the third row of sensors 12c (the remaining sensors from the first row through the nth row) in the fourth direction DIR4 overlaps with the third side H3. The remaining structure of the third row of sensors 12c is identical to that of the first row of sensors 12a, and therefore, description thereof will be omitted.

[0103] (Effect)

[0104] Such a position detection device 1 d achieves the same effects as the position detection device 1 .

[0105] [Variation 5]

[0106] Hereinafter, a position detection device 1e according to a fifth modification will be described with reference to the drawings. Figure 11 This is a diagram showing a position detection device 1 e according to a fifth modification of the position detection device 1 .

[0107] The position detection device 1e differs from the position detection device 1c in that it includes two first row sensors 11a and 11a2, two second row sensors 11b and 11b2, two first column sensors 12a and 12a2, and two second column sensors 12b and 12b2.

[0108] The first line sensor 11a2 overlaps the straight line SL1 when viewed along the Z-axis direction. The end of the first line sensor 11a2 in the fifth direction DIR5 overlaps the second side H2. The rest of the structure of the first line sensor 11a2 is the same as that of the first line sensor 11a, so its description is omitted.

[0109] The second line sensor 11b2 overlaps the straight line SL4 when viewed along the Z axis. The end of the second line sensor 11b2 in the fifth direction DIR5 overlaps the second side H2. The rest of the structure of the second line sensor 11b2 is the same as that of the first line sensor 11a, so its description is omitted.

[0110] The first row of sensors 12a2 overlaps with the straight line SL2 when viewed along the Z-axis direction. The end of the first row of sensors 12a2 in the fourth direction DIR4 overlaps with the third side H3. The remaining structure of the first row of sensors 12a2 is the same as that of the first row of sensors 12a, and therefore, description thereof is omitted.

[0111] The second row of sensors 12b2 overlaps with the straight line SL3 when viewed along the Z-axis direction. The end of the second row of sensors 12b2 in the fourth direction DIR4 overlaps with the third side H3. The remaining structure of the second row of sensors 12b2 is the same as that of the first row of sensors 12a, and therefore, description thereof will be omitted.

[0112] Furthermore, position detection device 1e differs from position detection device 1c in that it includes sensor 14a (first sensor), sensor 14b (first sensor), and sensor 15b (second sensor), which do not overlap with the outer edge of elastic member 10 when viewed along the Z-axis direction. Sensor 14a of position detection device 1e is identical to sensor 14a of position detection device 1b, and therefore, description thereof will be omitted.

[0113] like Figure 11 As shown, sensor 14b is located between the first row of sensors 12a and the second row of sensors 12b when viewed along the second direction DIR2. Sensor 14b overlaps with line SL4 when viewed along the Z-axis direction. The rest of the structure of sensor 14b is the same as that of sensor 14a, so its description is omitted.

[0114] The sensor 15b is located between the first row of sensors 11a and the second row of sensors 11b when viewed along the third direction DIR3. The sensor 15b overlaps the straight line SL3 when viewed along the Z-axis direction. The rest of the structure of the sensor 15b is the same as that of the sensor 15a, so its description is omitted.

[0115] exist Figure 11In the illustrated example, the first main surface UF10 of the elastic member 10 is divided into nine regions, namely, region Ar1 a to region Ar9 a , by the twelve sensors 11 , similarly to the first embodiment.

[0116] Such a position detection device 1 e achieves the same effects as those of the position detection device 1 and the same effects as those of the position detection devices 1 a to 1 d.

[0117] [Variation 6]

[0118] Below, refer to Figures 11 to 14 , the position detection device 1f of modification example 6 is described. Figure 12 This is a graph showing experimental results Re1 obtained through experiments conducted by the inventors of the present application. Figure 13 This is a graph showing experimental results Re2 obtained through experiments by the inventors of the present application. Figure 14 This is a graph showing experimental results Re3 obtained through experiments by the inventors of the present application.

[0119] The position detection device 1 f differs from the position detection device 1 in that the position where the elastic member 10 is deformed is determined based on a machine learning algorithm.

[0120] Through experiments, the inventors of the present application discovered a relationship between the correlation coefficient between the values ​​of the signals output by two sensors among the plurality of sensors 11 and the position at which the elastic member 10 deformed. Consequently, the inventors discovered that the position at which the elastic member 10 deformed could be determined based on this relationship. This is described in detail below.

[0121] The inventor of this application Figure 11 The following experiment was conducted in the position detection device 1f shown in FIG. When the elastic member 10 is deformed, the mutual correlation coefficient of the values ​​of the signals output by two sensors among the plurality of sensors 11 is calculated. Figure 11 In the example shown, for example, a region located on the negative side of the Y axis relative to line SL3 and on the negative side of the X axis relative to line SL4 is pressed. In this case, for example, the cross-correlation coefficient (first cross-correlation coefficient) between the values ​​of the signals output by sensor 11a in the first row and the values ​​of the signals output by sensor 15a in the plurality of sensors 11 is calculated. For example, the first cross-correlation coefficient is obtained by multiplying the values ​​of the signals output by sensor 11a in the first row by the values ​​of the signals output by sensor 15a. In this case, the first cross-correlation coefficient indicates the strength of the correlation between the values ​​of the signals output by sensor 11a in the first row and the values ​​of the signals output by sensor 15a. The same calculation is performed for all combinations of two sensors in the plurality of sensors 11. In this manner, multiple cross-correlation coefficients can be obtained.

[0122] Next, the inventors of the present application performed principal component analysis on a plurality of mutual correlation coefficients. Principal component analysis is an example of unsupervised learning. Principal component analysis is a method of determining the number of principal components corresponding to the type of data based on the deviation (variance) of a plurality of data to be analyzed. For example, in a two-dimensional graph consisting of the axis of the first principal component and the axis of the second principal component as the main principal component, the principal component scores of the first principal component and the second principal component are marked. In this way, the feature quantities of three or more dimensions possessed by a plurality of data can be reduced to two-dimensional feature quantities. The inventors of the present application obtained the feature quantity by performing principal component analysis on a plurality of mutual correlation coefficients. Figure 12 results.

[0123] Similarly, the inventors of this application analyzed multiple correlation coefficients using the t-SNE method to obtain Figure 13 The t-SNE method is a common method, so the description is omitted. Similarly, the inventors of this application analyzed multiple mutual correlation coefficients using the umap method to obtain Figure 14 The umap method is a common method, so its description is omitted.

[0124] The inventor of this application studied Figure 12 、 Figure 13 as well as Figure 14 As a result, the inventors of this application noticed that Figure 12 、 Figure 13 as well as Figure 14 There are characteristics in the positions where multiple correlation coefficients are plotted. Specifically, the inventors of this application noticed that multiple correlation coefficients are divided into 9 groups CL1 to CL9 based on the positions where the multiple correlation coefficients are plotted. Here, in the position detection device 1f used in this experiment, the first main surface UF10 of the elastic member 10 is divided into 9 areas Ar1a to Ar9a by 12 sensors 11. In other words, Figure 12 、 Figure 13 as well as Figure 14 The number of groups of is equal to the number of regions on the first main surface UF10. Therefore, the inventors of the present application have noticed that there is a relationship between a plurality of cross-correlation coefficients and the position where the elastic member 10 is deformed.

[0125] Based on the above, the inventors of the present application have devised a method of storing a learning model obtained by pre-learning the relationship between multiple cross-correlation coefficients and the position of deformation of the elastic member 10 in the calculation circuit 13. This learning model is pre-learned based on supervisory data indicating the relationship between the multiple cross-correlation coefficients and the position of deformation of the elastic member 10. The learning model inputs the values ​​of the multiple cross-correlation coefficients. The learning model infers the position of deformation of the elastic member 10 based on the values ​​of the multiple cross-correlation coefficients. The calculation circuit 13 corrects the learning model based on the inference results. As a result, the calculation circuit 13 improves the accuracy of determining the position of deformation in the elastic member 10.

[0126] [Variation 7]

[0127] Below, use Figure 11 Next, a position detection device 1g according to a seventh modification will be described. In the position detection device 1g, the calculation circuit 13 determines the position where the elastic member 10 is deformed by using a multivariate regression analysis.

[0128] The magnitude of the output value of each of the multiple sensors 11 depends on the displacement of the position where the multiple sensors 11 are provided in the elastic member 10 (hereinafter referred to as the sensor position). For example, the magnitude of the value of the signal output by the first row sensor 11a depends on the displacement of the position where the first row sensor 11a is provided in the elastic member 10. In addition, the magnitude of the output of each of the multiple sensors 11 depends on the position where the elastic member 10 is deformed. For example, the magnitude of the value of the signal output by the first row sensor 11a when the end portion of the elastic member 10 in the negative direction of the Y axis is deformed is smaller than the magnitude of the value of the signal output by the first row sensor 11a when the end portion of the elastic member 10 in the positive direction of the Y axis is deformed. The same is true for the sensors other than the first row sensor 11a among the multiple sensors 11. In this case, the relationship of the determinant 1 shown below holds between the output values ​​of the multiple sensors 11, the displacement of the sensor position, and the position where the elastic member 10 is deformed.

[0129] [Mathematical formula 1]

[0130] [Determinant 1]

[0131]

[0132] The output value of the sensor in the determinant 1 is the maximum value of each signal output by the plurality of sensors 11 when the elastic member 10 is deformed. Figure 11 In the example shown, the number of the plurality of sensors 11 is 12. Therefore, the number of columns of the matrix Y, the number of rows of the output transformation matrix P, the number of columns of the output transformation matrix P, and the number of columns of the matrix Q are each 12. Figure 11In the example shown, the first main surface UF10 of the elastic member 10 is divided into 9 areas by 12 multiple sensors 11 in the same manner as in the first embodiment. Therefore, the number of rows of the matrix Q and the number of columns of the matrix X are each 9. The output transformation matrix P is a coefficient obtained by pre-performing a multiple regression analysis on the position where the elastic member 10 is deformed and the signals output by each of the multiple sensors 11. The output transformation matrix P changes due to the respective attachment methods of the multiple sensors 11, the torsion and bending of the multiple sensors 11, and the like. The output transformation matrix P×matrix Q (output transformation matrix×change in the position of the sensor) can be obtained using machine learning. The output transformation matrix P×matrix Q is obtained by calculating the relationship between each of the multiple sensors 11 and the position where the elastic member 10 is deformed as a multiple regression model.

[0133] From Determinant 1, if we replace it with Matrix A = Output Transformation Matrix P × Matrix Q, then Determinant 2 shown below holds. From Determinant 2, Determinant 3 holds.

[0134] [Mathematical formula 2]

[0135] [Determinant 2]

[0136] Y=AX

[0137] Y: output value of the sensor

[0138] A: (output transformation matrix) (displacement of sensor position)

[0139] X: The position where the elastic member is deformed

[0140] [Mathematical formula 3]

[0141] [Determinant 3]

[0142] A -1 YX

[0143] A -1 :Pseudo-inverse matrix of A

[0144] According to the determinant 3, the position of the elastic member 10 deformation is obtained by multiplying the values ​​of the signals outputted by the plurality of sensors 11 by the matrix A. -1 Therefore, the calculation circuit 13 can multiply the matrix A based on the values ​​of the signals outputted by each of the plurality of sensors 11. -1 (First Matrix) The value obtained determines the position where the elastic member 10 is deformed. -1 It is obtained based on the output transformation matrix P×matrix Q obtained by multivariate regression analysis. Therefore, the matrix A -1The (first matrix) is a generalized inverse matrix of the matrix A (second matrix) based on coefficients obtained by performing a multivariate regression analysis on the position of the elastic member 10 deformed and the signals outputted by each of the plurality of sensors 11 .

[0145] (Effect)

[0146] In this variation, the calculation circuit 13 determines the position of the elastic member 10 at which it has deformed based on an output transformation matrix P × a matrix Q previously calculated through machine learning. In this case, the values ​​included in the output transformation matrix P × a matrix Q take into account the noise generated by the signals output by the multiple sensors 11. Therefore, when determining the position of the elastic member 10 at which it has deformed, the calculation circuit 13 is less likely to be affected by the noise generated by the signals output by the multiple sensors 11. As a result, the calculation circuit 13 is less likely to erroneously determine the position of the elastic member 10 at which it has deformed.

[0147] [Variation 8]

[0148] Below, use Figure 11 Next, a description will be given of a position detection device 1h according to Modification 8. The position detection device 1h specifies the position where the elastic member 10 is deformed by using a matrix based on the cross-correlation coefficient.

[0149] As described in Modification 6, there is a relationship between the plurality of cross-correlation coefficients and the position at which the elastic member 10 is deformed. Therefore, Determinant 4 shown below holds. Furthermore, Determinant 5 holds based on Determinant 4.

[0150] [Formula 4]

[0151] [Determinant 4]

[0152]

[0153] [Formula 5]

[0154] [Determinant 5]

[0155] S -1 B=X

[0156] According to the determinant 5, the operation circuit 13 can multiply the matrix B by the matrix S -1 The obtained value determines the position where the elastic member 10 is deformed. Such a position detection device 1h has the same effect as the position detection device 1g.

[0157] [Variation 9]

[0158] Below, use Figure 11 , the position detection device 1i of the modification 9 is described. The position detection device 1i is based on the matrix A -1 and matrix A-1 The position where the elastic member 10 is deformed is determined by a matrix other than the matrix.

[0159] Specifically, similar to Modification 6, calculation circuit 13 calculates the cross-correlation coefficient between two sensors in the plurality of sensors 11 based on the signals output by each of the plurality of sensors 11. This calculation circuit 13 performs for all combinations of two sensors in the plurality of sensors 11. This yields Determinant 6 shown below. Furthermore, from Determinant 6 and Determinant 2, Determinant 7 shown below holds. Furthermore, from Determinant 7, Determinant 8 holds.

[0160] [Formula 6]

[0161] [Determinant 6]

[0162]

[0163] Y t :Y transposed matrix

[0164] [Formula 7]

[0165] [Determinant 7]

[0166] B=AX(AX) t

[0167] [Formula 8]

[0168] [Determinant 8]

[0169] XX t =A -1 B(A t ) -1

[0170] The operation circuit 13 determines the position where the elastic member 10 is deformed based on the determinant 8. Specifically, the operation circuit 13 determines the position where the elastic member 10 is deformed based on the matrix A -1 (1st matrix), transposed matrix A based on matrix A t And matrix B (the third matrix) to calculate the matrix XX t Therefore, in this modification, the operation circuit 13 is based on the matrix A -1 (1st matrix), matrix A (2nd matrix) and matrix B (3rd matrix) to calculate matrix XX t (4th matrix). The calculation circuit 13 is based on the matrix XX t (4th matrix) determines the position where the elastic member 10 is deformed. Specifically, the operation circuit 13 calculates the position of the elastic member 10 according to the matrix XX. t Calculate the matrix X to determine the position where the elastic member 10 is deformed. tEach of the one or more diagonal components of the (fourth matrix) has a value correlated with a position where the elastic member 10 is deformed.

[0171] (Effect)

[0172] In position detection device 1i, calculation circuit 13 determines the position of elastic member 10 at deformation based on artificial intelligence, similarly to calculation circuit 13 of position detection device 1g. Therefore, similarly to position detection device 1f, calculation circuit 13 of position detection device 1i is less likely to erroneously determine the position of elastic member 10 at deformation.

[0173] [Other modifications]

[0174] The present invention is not limited to the position detection devices 1 and 1a to 1i, and can be modified within the scope of the gist thereof.

[0175] Furthermore, the X-axis, Y-axis, and Z-axis directions are defined for the purpose of explanation. Therefore, the X-axis, Y-axis, and Z-axis directions in actual use of the position detection device do not necessarily need to be consistent with those in the embodiments and modifications.

[0176] Furthermore, the first direction DIR1, the second direction DIR2, the third direction DIR3, the fourth direction DIR4, and the fifth direction DIR5 are defined for the purpose of explanation. Therefore, the first direction DIR1, the second direction DIR2, the third direction DIR3, the fourth direction DIR4, and the fifth direction DIR5 in actual use of the position detection device do not necessarily need to coincide with the first direction DIR1, the second direction DIR2, the third direction DIR3, the fourth direction DIR4, and the fifth direction DIR5 of each embodiment and each modified example. For example, the positive direction of the Z axis may coincide with the first direction DIR1.

[0177] Furthermore, each of the plurality of sensors 11 may be provided on either the first principal surface UF10 or the second principal surface DF10. Thus, in the position detection device 1, the first row sensor 11a may be provided on the first principal surface UF10, and the first column sensor 12a and the second column sensor 12b may be provided on the second principal surface DF10.

[0178] Furthermore, the piezoelectric film of each of the plurality of sensors 11 does not necessarily need to be PLLA. The piezoelectric film of each of the plurality of sensors 11 may also be PVDF.

[0179] Furthermore, the piezoelectric films of the plurality of sensors 11 do not necessarily need to be organic piezoelectric materials such as PLLA. The piezoelectric films of the plurality of sensors 11 may also be inorganic piezoelectric materials such as PZT.

[0180] Furthermore, the first electrode 110a does not necessarily need to be a reference electrode, and the second electrode 112a does not necessarily need to be a signal electrode. For example, the first electrode 110a may be a signal electrode, and the second electrode 112a may be a reference electrode.

[0181] Furthermore, in the position detection device 1c, the sensor 15a may overlap with the straight line SL3 (the second straight line). In this case, the second straight line overlaps with any one of the sensors in the first to nth columns when viewed along the first direction DIR1, and the second sensor overlaps with the second straight line when viewed along the first direction DIR1.

[0182] Alternatively, the plurality of sensors 11 of the position detection device 1c may include sensor 14a (first sensor). In this case, sensor 14a may overlap with straight line SL1 (first straight line) or straight line SL4 (first straight line). In this case, the first straight line overlaps with any one of the first to m-th row sensors when viewed along the first direction DIR1, and the first sensor overlaps with the first straight line when viewed along the first direction DIR1.

[0183] In addition, Figure 1 and Figure 2 In the example shown, end E11a is disposed on first side H1 so as to form an angle of 0 degrees with respect to first side H1. However, end E11a may also be disposed on first side H1 so as to form an angle of approximately 0 degrees ± 10 degrees with respect to first side H1. The same applies to ends other than end E11a (ends E12a, E12b, etc.).

[0184] In addition, the end E11a may be slightly offset from the first side H1. The same applies to the ends other than the end E11a (ends E12a, E12b, etc.).

[0185] Furthermore, in the first main surface UF10, the number of the plurality of sensors can be changed in accordance with the number of regions where the calculation circuit 13 detects deformation. Specifically, when the calculation circuit 13 detects deformation in each of the number of x×y regions (x is a natural number greater than or equal to 2) in the first main surface UF10, "the number of the plurality of sensors = (x-1) + (y-1)". For example, Figure 2 As shown in FIG, when the arithmetic circuit 13 detects deformation of each of the 2×3 regions, “the number of sensors = 3 (1 + 2)”. Therefore, as Figure 2 As shown, the position detection device 1 only needs to include three sensors: a first row sensor 11 a , a first column sensor 12 a , and a second column sensor 12 b .

[0186] Furthermore, in the position detection device 1f, the calculation circuit 13 may not necessarily determine the position of the elastic member 10 deformed by principal component analysis. Alternatively, the calculation circuit 13 may determine the position of the elastic member 10 deformed by a method other than principal component analysis based on the relationship between multiple cross-correlation coefficients and the position of the elastic member 10 deformed. For example, the calculation circuit 13 may determine the position of the elastic member 10 deformed by a method using a supervised signal, such as a decision tree or random forest. For example, the calculation circuit 13 may determine the position of the elastic member 10 deformed by an algorithm based on supervised learning, such as a support vector machine (SVM).

[0187] Furthermore, an electronic device such as a smartphone includes a position detection device 1. In this case, for example, the upper surface of the housing of the electronic device corresponds to the elastic member 10. In this case, a user presses the upper surface of the housing, causing the housing to deform. Consequently, the position detection device 1 can determine the location of the deformation on the upper surface of the housing.

[0188] Furthermore, the bottom surface of the housing of the electronic device may correspond to the elastic member 10. In this case, the user presses the bottom surface of the housing with, for example, the ring finger or little finger of the user holding the housing. As a result, the bottom surface of the housing is deformed. As a result, the position detection device 1 can determine the position of the deformation in the bottom surface of the housing. For example, the user presses the bottom surface of the housing with a finger while operating the screen of an electronic device such as a smartphone. In this case, the electronic device includes, in addition to a structure for performing processing based on the user's operation on the screen, a structure for performing processing based on the user's operation on the bottom surface of the housing. Furthermore, the side surface of the housing of the electronic device may correspond to the elastic member 10.

[0189] Furthermore, the positive or negative sign in the X-axis direction or the Y-axis direction may not coincide with the positive or negative sign of the first signal Sig1 output by the first row sensor 11a. For example, when the end of the elastic member 10 in the positive direction of the X-axis is deformed, the polarity of the first signal Sig1 may be either positive or negative. For example, when the end of the elastic member 10 in the negative direction of the X-axis is deformed, the polarity of the first signal Sig1 may be either positive or negative. The same applies to the positive or negative sign of the second signal output by the first column sensor 12a or the positive or negative sign of the third signal output by the second column sensor 12b.

[0190] The present invention has the following configuration. (1)

[0192] A position detection device, wherein:

[0193] The position detection device comprises:

[0194] an elastic member having a first main surface and a second main surface arranged along a first direction; and

[0195] Multiple sensors,

[0196] The plurality of sensors are each provided on the first main surface or the second main surface,

[0197] The plurality of sensors include:

[0198] The first to m-th row sensors have first ends overlapping with an outer edge of the first main surface or the second main surface; and

[0199] The first to nth row sensors have second ends overlapping with the outer edge of the first main surface or the second main surface,

[0200] The m and n are each a natural number,

[0201] The third direction intersects the second direction,

[0202] The first end is an end of the first to m-th row of sensors in either the third direction or a direction opposite to the third direction when viewed along the first direction.

[0203] The second end is an end of the first to n-th rows of sensors in either the second direction or a direction opposite to the second direction when viewed along the first direction.

[0204] The positions of the sensors in the first row to the mth row in the second direction are arranged in sequence along the second direction.

[0205] The positions of the first to nth row of sensors in the third direction are arranged in sequence along the third direction.

[0206] The first to m-th row sensors each include a first piezoelectric film having piezoelectricity in which molecules are oriented along a first orientation direction under uniaxial stretching, and are arranged so that the first orientation direction is parallel to the third direction.

[0207] Each of the first to n-th row sensors includes a second piezoelectric film having piezoelectricity in which molecules are oriented along a second orientation direction under uniaxial stretching, and is arranged so that the second orientation direction is parallel to the second direction. (2)

[0209] The position detection device according to (1), wherein

[0210] Each of m and n is a natural number greater than 2,

[0211] When viewed along the first direction, the first ends of some of the sensors in the first to m-th rows of sensors in the third direction overlap with the outer edge of the first main surface or the second main surface.

[0212] When viewed along the first direction, the first ends of the remaining sensors in the first to m-th row of sensors in the direction opposite to the third direction overlap with the outer edge of the first main surface or the second main surface.

[0213] When viewed along the first direction, the second ends of some of the sensors in the first to n-th rows overlap with the outer edge of the first main surface or the second main surface.

[0214] When viewed along the first direction, the second ends of the remaining sensors in the first to n-th rows of sensors, in the direction opposite to the second direction, overlap with the outer edge of the first main surface or the second main surface. (3)

[0216] The position detection device according to (1) or (2), wherein:

[0217] The plurality of sensors further include a first sensor,

[0218] The first sensor includes a third piezoelectric film having piezoelectricity in which molecules are oriented along a third orientation direction under uniaxial stretching, and is arranged so that the third orientation direction is parallel to the third direction.

[0219] The first straight line is parallel to the third direction and overlaps with any one of the first to m-th row of sensors when viewed along the first direction.

[0220] The first sensor overlaps with the first straight line when viewed along the first direction. (4)

[0222] The position detection device according to (3), wherein

[0223] The n is a natural number greater than 2,

[0224] The first sensor is located between two adjacent sensors in the first to nth row of sensors when viewed along the second direction. (5)

[0226] The position detection device according to any one of (1) to (4), wherein

[0227] The plurality of sensors further include a second sensor,

[0228] The second sensor includes a fourth piezoelectric film having piezoelectricity in which molecules are oriented along a fourth orientation direction under uniaxial stretching.

[0229] The second sensor is arranged so that the fourth orientation direction is parallel to the second direction.

[0230] The second straight line is parallel to the second direction and overlaps with any one of the first to nth row of sensors when viewed along the first direction.

[0231] The second sensor overlaps with the second straight line when viewed along the first direction. (6)

[0233] The position detection device according to (5), wherein

[0234] The m is a natural number greater than 2,

[0235] The second sensor is located between two adjacent sensors in the first to m-th row of sensors when viewed along the third direction. (7)

[0237] The position detection device according to any one of (1) to (6), wherein

[0238] The position detection device further includes an operation circuit,

[0239] Each of the plurality of sensors outputs a signal corresponding to the deformation of the elastic member.

[0240] The arithmetic circuit determines a position where the elastic member is deformed based on the signals outputted by each of the plurality of sensors. (8)

[0242] The position detection device according to (7), wherein

[0243] The arithmetic circuit specifies a position where the elastic member is deformed based on a value obtained by multiplying a value of the signal outputted from each of the plurality of sensors by a first matrix. (9)

[0245] The position detection device according to (8), wherein

[0246] The first matrix is ​​a generalized inverse matrix of the second matrix based on coefficients obtained by performing a multivariate regression analysis on the position of the elastic member deformed and the signals outputted by each of the plurality of sensors. (10)

[0248] The position detection device according to (9), wherein

[0249] The calculation circuit calculates a correlation coefficient between two sensors among the plurality of sensors based on the signals outputted by each of the plurality of sensors.

[0250] The calculation circuit calculates a third matrix based on the cross-correlation coefficient.

[0251] The calculation circuit calculates a fourth matrix based on the first matrix, the second matrix, and the third matrix.

[0252] The calculation circuit determines the position where the elastic member is deformed based on the fourth matrix. (11)

[0254] The position detection device according to (10), wherein

[0255] Each of the one or more diagonal components of the fourth matrix has a value correlated with a position at which the elastic member is deformed.

[0256] Description of Reference Numerals

[0257] 1. 1a to 1g, position detection device; 10, elastic member; 11, multiple sensors; 11a, 11a2, first row sensors; 11b, 11b2, second row sensors; 12a, 12a2, first column sensors; 12b, 12b2, second column sensors; 111a, 111b, 121a, 121b, piezoelectric film; UF10, first main surface; DF10, second main surface; E11a, E11b, E11c, E12a, E12b, E12c, end; OD1a, OD1b, OD2a, OD2b, OD4a, OD5a, orientation direction.

Claims

1. A position detection device, wherein: The position detection device comprises: an elastic member having a first main surface and a second main surface arranged along a first direction; and Multiple sensors, The plurality of sensors are each provided on the first main surface or the second main surface, The plurality of sensors include: The first to m-th row sensors have first ends overlapping with an outer edge of the first main surface or the second main surface; and The first to nth row sensors have second ends overlapping with the outer edge of the first main surface or the second main surface, The m and n are each a natural number, The third direction intersects the second direction, The first end is an end of the first to m-th row of sensors in either the third direction or a direction opposite to the third direction when viewed along the first direction. The second end is an end of the first to n-th rows of sensors in either the second direction or a direction opposite to the second direction when viewed along the first direction. The positions of the sensors in the first row to the mth row in the second direction are arranged in sequence along the second direction. The positions of the first to nth row of sensors in the third direction are arranged in sequence along the third direction. The first to m-th row sensors each include a first piezoelectric film having piezoelectricity in which molecules are oriented along a first orientation direction under uniaxial stretching, and are arranged so that the first orientation direction is parallel to the third direction. Each of the first to n-th row sensors includes a second piezoelectric film having piezoelectricity in which molecules are oriented along a second orientation direction under uniaxial stretching, and is arranged so that the second orientation direction is parallel to the second direction.

2. The position detection device according to claim 1, wherein: Each of m and n is a natural number greater than 2, When viewed along the first direction, the first ends of some of the sensors in the first to m-th rows of sensors in the third direction overlap with the outer edge of the first main surface or the second main surface. When viewed along the first direction, the first ends of the remaining sensors in the first to m-th row of sensors in the direction opposite to the third direction overlap with the outer edge of the first main surface or the second main surface. When viewed along the first direction, the second ends of some of the sensors in the first to n-th rows overlap with the outer edge of the first main surface or the second main surface. When viewed along the first direction, the second ends of the remaining sensors in the first to n-th rows of sensors, in the direction opposite to the second direction, overlap with the outer edge of the first main surface or the second main surface.

3. The position detection device according to claim 1 or 2, wherein: The plurality of sensors further include a first sensor, The first sensor includes a third piezoelectric film having piezoelectricity in which molecules are oriented along a third orientation direction under uniaxial stretching, and is arranged so that the third orientation direction is parallel to the third direction. The first straight line is parallel to the third direction and overlaps with any one of the first to m-th row of sensors when viewed along the first direction. The first sensor overlaps with the first straight line when viewed along the first direction.

4. The position detection device according to claim 3, wherein: The n is a natural number greater than 2, The first sensor is located between two adjacent sensors in the first to nth row of sensors when viewed along the second direction.

5. The position detection device according to any one of claims 1 to 4, wherein: The plurality of sensors further include a second sensor, The second sensor includes a fourth piezoelectric film having piezoelectricity in which molecules are oriented along a fourth orientation direction under uniaxial stretching. The second sensor is arranged so that the fourth orientation direction is parallel to the second direction. The second straight line is parallel to the second direction and overlaps with any one of the first to nth row of sensors when viewed along the first direction. The second sensor overlaps with the second straight line when viewed along the first direction.

6. The position detection device according to claim 5, wherein: The m is a natural number greater than 2, The second sensor is located between two adjacent sensors in the first to m-th row of sensors when viewed along the third direction.

7. The position detection device according to any one of claims 1 to 6, wherein: The position detection device further includes an operation circuit, Each of the plurality of sensors outputs a signal corresponding to the deformation of the elastic member. The arithmetic circuit determines a position where the elastic member is deformed based on the signals outputted by each of the plurality of sensors.

8. The position detection device according to claim 7, wherein: The arithmetic circuit specifies a position where the elastic member is deformed based on a value obtained by multiplying a value of the signal outputted from each of the plurality of sensors by a first matrix.

9. The position detection device according to claim 8, wherein: The first matrix is ​​a generalized inverse matrix of the second matrix based on coefficients obtained by performing a multivariate regression analysis on the position of the elastic member deformed and the signals outputted by each of the plurality of sensors.

10. The position detection device according to claim 9, wherein: The calculation circuit calculates a correlation coefficient between two sensors among the plurality of sensors based on the signals outputted by each of the plurality of sensors. The calculation circuit calculates a third matrix based on the cross-correlation coefficient. The calculation circuit calculates a fourth matrix based on the first matrix, the second matrix, and the third matrix. The calculation circuit determines the position where the elastic member is deformed based on the fourth matrix.

11. The position detection device according to claim 10, wherein: Each of the one or more diagonal components of the fourth matrix has a value correlated with a position at which the elastic member is deformed.

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