Position detection device

Abstract

A position detection device wherein: a first end, viewed in a first direction, is the end, in either a third direction or a direction opposite to the third direction, of a first row sensor to an m-th row sensor; a second end, viewed in the first direction, is the end, in either a second direction or a direction opposite to the second direction, of a first column sensor to an n-th column sensor; each of the first row sensor to m-th row sensor contains a first piezoelectric film that exhibits piezoelectricity wherein, upon uniaxial stretching, the molecules undergo orientation in a first orientation direction; the first orientation direction is disposed in parallel to the third direction; each of the first column sensor to the n-th column sensor contains a second piezoelectric film that exhibits piezoelectricity wherein, upon uniaxial stretching, the molecules undergo orientation in a second orientation direction; and the second orientation direction is disposed in parallel to the second direction.

Description

[Technical Field]

[0001] The present invention relates to a position detection device equipped with a sensor that detects deformation of a member. [Background technology]

[0002] Patent Document 1 describes a position detection device. The position detection device includes a protective layer, a stripe electrode, a piezoelectric body, a single electrode, and an arithmetic circuit. The piezoelectric body is located between the stripe electrode and the single electrode. When viewed in the direction in which the protective layer, stripe electrode, piezoelectric body, and single electrode are arranged, the piezoelectric body overlaps the entire surface of the protective layer. A user presses the protective layer, which causes the protective layer to deform. The deformation of the protective layer also causes the piezoelectric body to deform. At this time, a voltage is generated between the stripe electrode and the single electrode. The arithmetic circuit identifies the position on the protective layer touched by the user based on the generated voltage. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-210081 Summary of the Invention [Problem to be solved by the invention]

[0004] In the field of the position detection device described in Patent Document 1, there is a demand for reducing the cost of the position detection device.

[0005] An object of the present invention is to provide a position detection device that can be easily reduced in cost. [Means for solving the problem]

[0006] A position detection device according to an embodiment of the present invention comprises: an elastic member having a first main surface and a second main surface aligned in a first direction; A plurality of sensors; It is equipped with Each of the plurality of sensors is provided on the first main surface or the second main surface, The plurality of sensors include: a first row sensor to an m-th row sensor having a first end overlapping an outer edge of the first main surface or the second main surface; first to n-th row sensors each having a second end overlapping an outer edge of the first main surface or the second main surface; It contains Each of the m and the n is a natural number, The third direction intersects with the second direction, the first ends are either ends of the first row sensors to the mth row sensors in the third direction or in a direction opposite to the third direction, when viewed in the first direction; the second ends are either ends of the first row sensors to the nth row sensors in the second direction or ends in a direction opposite to the second direction, when viewed in the first direction; the positions of the first row sensors to the m-th row sensors in the second direction are aligned in this order in the second direction; the positions of the first row sensors to the n-th row sensors in the third direction are aligned in this order in the third direction; Each of the first row sensors to the mth row sensors includes a first piezoelectric film that is uniaxially stretched and has piezoelectricity in which molecules are oriented in a first orientation direction, and is arranged so that the first orientation direction is parallel to the third direction; Each of the first row sensors to the nth row sensors includes a second piezoelectric film that is uniaxially stretched and has piezoelectricity in which the molecules are oriented in a second orientation direction, and is arranged so that the second orientation direction is parallel to the second direction. [Effects of the Invention]

[0007] 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 explanation of the drawings]

[0008] [Figure 1]FIG. 1 is a perspective view of a position detection device 1 according to the first embodiment. [Figure 2] FIG. 2 is a view of the position detection device 1 as viewed in the negative direction of the Z axis. [Figure 3] FIG. 3 is a cross-sectional view taken along line AA in FIG. [Figure 4] FIG. 4 is a diagram showing an example of a first signal Sig1 output by the first row sensor 11a when a first region Ar1 located on the first principal surface UF10 on the negative side of the X axis from the first row sensor 11a is deformed. [Figure 5] FIG. 5 is a diagram showing an example of a first signal Sig1 output by the first row sensor 11a when a second region Ar2 located on the first principal surface UF10 on the positive side of the X axis from the first row sensor 11a is deformed. [Figure 6] FIG. 6 is a flowchart showing an example of the process U of the arithmetic circuit 13. [Figure 7] FIG. 7 is a diagram showing a position detection device 1a according to a first modification of the position detection device 1. In FIG. [Figure 8] FIG. 8 is a diagram showing a position detection device 1b according to a second modification of the position detection device 1. In FIG. [Figure 9] FIG. 9 is a diagram showing a position detection device 1c according to a third modification of the position detection device 1. In FIG. [Figure 10] FIG. 10 is a diagram showing a position detection device 1d according to a fourth modification of the position detection device 1. In FIG. [Figure 11] FIG. 11 is a diagram showing a position detection device 1e according to a fifth modification of the position detection device 1. In FIG. [Figure 12] FIG. 12 is a diagram showing an experimental result Re1 obtained by the inventor of the present invention. [Figure 13] FIG. 13 is a diagram showing an experimental result Re2 obtained by the inventor of the present invention. [Figure 14] FIG. 14 is a diagram showing an experimental result Re3 obtained by the inventor of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0009] [First embodiment] A position detection device 1 according to a first embodiment of the present invention will be described below with reference to the drawings. Fig. 1 is a perspective view of the position detection device 1 according to the first embodiment. Fig. 2 is a view of the position detection device 1 as seen in the negative direction of the Z axis. Fig. 3 is a cross-sectional view taken along line AA in Fig. 1.

[0010] In this embodiment, directions are defined as follows. As shown in FIG. 1 , the direction in which the multiple sensors 11 and the elastic member 10 are lined up is defined as the Z-axis direction. The direction in which the multiple sensors 11 and the elastic member 10 are lined up in this order is defined as the negative direction of the Z-axis. The direction in which the elastic member 10 and the multiple sensors 11 are lined up in this order 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 and X-axis directions is defined as the Y-axis direction. Furthermore, 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 opposite to 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 to the third direction DIR3.

[0011] In this embodiment, the position detection device 1 is a device provided in an electronic device such as a smartphone, etc. The position detection device 1 includes an elastic member 10, a plurality of sensors 11, and an arithmetic circuit 13, as shown in FIGS.

[0012] As shown in FIGS. 1 and 2, 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 aligned in a first direction DIR1. The first principal surface UF10 and the second principal surface DF10 are aligned in this order 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 has elasticity. Therefore, the elastic member 10 is deformed by an external force applied to the elastic member 10. For example, the user presses the second principal surface DF10 of the elastic member 10 in the positive direction of the Z axis. The force applied to the elastic member 10 in the positive direction of the Z axis causes the elastic member 10 to deform.

[0013] In this embodiment, the plurality of sensors 11 includes a plurality of sensors that are in contact with the outer edge of the elastic member 10 when viewed in the Z-axis direction. Specifically, as shown in Figures 1 and 2, the plurality of sensors 11 includes first row sensors to m-th row sensors and first column sensors to n-th column sensors.

[0014] The first row sensor to the m-th row sensor are one or more sensors lined up in the second direction DIR2. Specifically, the positions of the first row sensor to the m-th row sensor in the second direction DIR2 are lined up in this order in the second direction DIR2. m is a natural number. In this embodiment, m is 1. Therefore, in this embodiment, as shown in FIGS. 1 and 2, the multiple sensors 11 include a first row sensor 11a.

[0015] As shown in FIG. 2, the first row sensor 11a has a rectangular shape with long sides extending along the Y-axis and short sides extending along the X-axis. The first row sensor 11a is provided on the first main surface UF10. In this embodiment, a part of the outer edge of the first row sensor 11a overlaps the outer edge of the first main surface UF10 when viewed in the Z-axis direction. Specifically, in this embodiment, the first row sensor 11a has an end E11a (first end). When viewed in the first direction DIR1, the end E11a is the end of the first row sensor 11a in the third direction DIR3. When viewed in the first direction DIR1, the end E11a overlaps the outer edge of the first main surface UF10. When viewed in the Z-axis direction, the end E11a overlaps the first side H1 of the first main surface UF10. As shown in FIG. 3, the first row sensor 11a includes a first electrode 110a, a piezoelectric film 111a (first piezoelectric film), a second electrode 112a, and a detection circuit (not shown).

[0016] 2 and 3, the piezoelectric film 111a has a sheet shape with short sides extending along the X-axis and long sides extending along the Y-axis. As shown in Fig. 3, the piezoelectric film 111a has a piezoelectric film first main surface SF1 and a piezoelectric film second main surface SF2 aligned in the Z-axis direction.

[0017] The piezoelectric film 111a generates a charge according to the amount of deformation of the piezoelectric film 111a. In the example shown in FIG. 2, 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 from a chiral polymer. An example of a chiral polymer is polylactic acid (PLA), particularly poly-L-lactic acid (PLLA). PLLA, which is made of a chiral polymer, has a helical main chain structure. PLLA has a piezoelectric property in which the molecules are oriented when uniaxially stretched. The piezoelectric film 111a has a piezoelectric constant of d14. As shown in FIG. 2, the piezoelectric film 111a (first piezoelectric film) has a piezoelectric property in which the molecules are oriented in an orientation direction OD1a (first orientation direction) when uniaxially stretched. In this embodiment, the first row sensor 11a is arranged such 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 angle includes, for example, angles of 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 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 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 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 the negative direction of the Y-axis. The magnitude of the generated charge depends on the differential value of the deformation of the piezoelectric film 111a due to stretching or compression.

[0018] The first electrode 110a is, for example, a reference electrode connected to a reference potential. As shown in Fig. 3, the first electrode 110a is fixed to the first main surface SF1 of the piezoelectric film with an adhesive (not shown) such as OCA. The first electrode 110a covers the first main surface SF1 of the piezoelectric film.

[0019] The second electrode 112a is, for example, a signal electrode. As shown in Fig. 3, the second electrode 112a is fixed to the second main surface SF2 of the piezoelectric film with an adhesive (not shown) such as OCA. The second electrode 112a covers the second main surface SF2 of the piezoelectric film.

[0020] The detection circuit converts the electric charge generated by the piezoelectric film 111a into a voltage signal, and then performs AD conversion on the voltage signal to generate a digital signal.

[0021] With the above configuration, the polarity of the signal output by the first row sensor 11a (hereinafter referred to as the first signal Sig1) changes depending on the position where the elastic member 10 is pressed. Hereinafter, a description will be given with reference to the drawings. FIG. 4 is a diagram showing an example of the first signal Sig1 output by the first row sensor 11a when a first region Ar1 located on the first principal surface UF10 on the negative side of the X-axis from the first row sensor 11a is deformed. FIG. 5 is a diagram showing an example of the first signal Sig1 output by the first row sensor 11a when a second region Ar2 located on the first principal surface UF10 on the positive side of the X-axis from the first row sensor 11a is deformed. Specifically, the first region Ar1 and the second region Ar2 are the following regions. A straight line SL1 (first straight line) parallel to the third direction DIR3 is defined. The straight line SL1 overlaps with the first row sensor 11a when viewed in the first direction DIR1. The first region Ar1 is located on the negative side of the X-axis from the straight line SL1. The second area Ar2 is located on the positive side of the X-axis from the straight line SL1.

[0022] 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. For example, at time t1 shown in FIG. 4, a user presses the first area Ar1. In this case, the piezoelectric film 111a is stretched in the negative direction of the X axis and the negative direction of the Y axis. At this time, the piezoelectric film 111a outputs a positive charge. Therefore, as shown in FIG. 4, the first row sensor 11a outputs the first signal Sig1 having a positive polarity with respect to the reference potential VE between time t1 and time t2, which is later than time t1. Next, at time t2, the user stops pressing the first area Ar1. A restoring force generated in the first row sensor 11a causes the first row sensor 11a to return to its original shape before deformation. This restoring force compresses the piezoelectric film 111a in the negative direction of the X axis and the negative direction of the Y axis. In this case, the piezoelectric film 111a outputs a negative charge. Therefore, as shown in FIG. 4, the first row sensor 11a outputs a first signal Sig1 having a positive polarity with respect to the reference potential VE at time t3, which is after time t2. As a result, during one cycle from when the user starts to press the first area Ar1 to when he or she stops, 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.

[0023] On the other hand, at time s1 shown in FIG. 5, the user presses the second region Ar2. In this case, the piezoelectric film 111a is stretched in the positive direction of the X-axis and the negative direction of the Y-axis. At this time, the piezoelectric film 111a outputs a negative charge. Therefore, as shown in FIG. 5, the first row sensor 11a outputs a first signal Sig1 having a negative polarity with respect to the reference potential VE between time s1 and time s2, which is later than time s1. Next, at time s2, the user stops pressing the second region Ar2. The first row sensor 11a is compressed in the positive direction of the X-axis and the negative direction of the Y-axis by a restoring force generated in 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 with respect to the reference potential VE. As a result, during one cycle from the start to the end of the user pressing the second area Ar2, the first row sensor 11a outputs a first signal Sig1 having a negative polarity with respect to the reference potential VE, and then outputs a first signal Sig1 having a positive polarity with respect to the reference potential VE.

[0024] The first to n-th column sensors are one or more sensors lined up in the third direction DIR3. Specifically, the positions of the first to n-th column sensors in the third direction DIR3 are lined up in this order in the third direction DIR3. n is a natural number. In this embodiment, n is a natural number equal to or greater than 2. In the example shown in FIGS. 1 and 2, n is 2. Therefore, in this embodiment, the multiple sensors 11 include a first column sensor 12a and a second column sensor 12b. The first column sensor 12a and the second column sensor 12b are lined up in this order at an interval in the negative direction of the Y axis.

[0025] As shown in FIG. 2, the first row sensor 12a has a rectangular shape with long sides extending along the X-axis and short sides extending along the Y-axis. The first row sensor 12a is provided on the first main surface UF10. In this embodiment, the first row sensor 12a has an end E12a (second end). When viewed in the first direction DIR1, the end E12a is the end of the first row sensor 12a in the second direction DIR2. When viewed in the first direction DIR1, the end E12a overlaps the outer edge of the first main surface UF10. As shown in FIG. 2, the end E12a overlaps the fourth side H4 of the first main surface UF10 when viewed in the Z-axis direction. The first row sensor 12a includes a piezoelectric film 121a (second piezoelectric film). The piezoelectric film 121a is uniaxially stretched to have piezoelectricity in which molecules are aligned in an alignment direction OD2a (second alignment direction). The first column sensor 12a is arranged such that the alignment direction OD2a is parallel to the second direction DIR2. The other configuration of the first column sensor 12a is the same as the configuration of the first row sensor 11a, so a description thereof will be omitted.

[0026] With the above configuration, similar 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 depending on the position where the elastic member 10 is pressed. Specifically, as shown in FIG. 2, a straight line SL2 (second straight line) parallel to the second direction DIR2 is defined. The straight line SL2 overlaps with the first column sensor 12a when viewed in the first direction DIR1. A third region Ar3 is defined as an area on the first principal surface UF10 that is located on the positive side of the Y-axis from the straight line SL2. A fourth region Ar4 is defined as an area on the first principal surface UF10 that is located on the negative side of the Y-axis from the straight line SL2. For example, during one cycle from when a user starts to press the third region Ar3 to when the user stops pressing the third region Ar3, the first column sensor 12a outputs a second signal having a positive polarity with respect to the reference potential VE, and then outputs a second signal having a negative polarity with respect to the reference potential VE. For example, in one cycle from when the user starts pressing the fourth area Ar4 to when he finishes, the first column sensor 12a outputs a second signal having a negative polarity with respect to the reference potential VE, and then outputs a second signal having a positive polarity with respect to the reference potential VE.

[0027] As shown in FIG. 2, the second row sensor 12b is provided on the first main surface UF10. In this embodiment, the second row sensor 12b has an end E12b (second end). When viewed in the first direction DIR1, the end E12b is the end of the second row sensor 12b in the second direction DIR2. When viewed in the first direction DIR1, the end E12b overlaps the outer edge of the first main surface UF10. In this embodiment, the end E12b overlaps the fourth side H4. The second row sensor 12b includes a piezoelectric film 121b (second piezoelectric film). The piezoelectric film 121b is uniaxially stretched and has piezoelectricity in which molecules are oriented in an orientation direction OD2b (second orientation direction). The second row sensor 12b is arranged so that the orientation direction OD2b is parallel to the second direction DIR2. The other configurations of the second row sensor 12b are the same as those of the first row sensor 12a, and therefore description thereof will be omitted.

[0028] With the above configuration, similar to the first row sensor 12a, the polarity of the signal (hereinafter referred to as the third signal) output by the second row sensor 12b changes depending on the position where the elastic member 10 is pressed. Specifically, as shown in FIG. 2, a straight line SL3 (second straight line) parallel to the second direction DIR2 is defined. The straight line SL3 overlaps with the second row sensor 12b when viewed in the first direction DIR1. A fifth region Ar5 is defined as an area on the first principal surface UF10 that is located on the positive side of the Y-axis from the straight line SL3. A sixth region Ar6 is defined as an area on the first principal surface UF10 that is located on the negative side of the Y-axis from the straight line SL3. For example, during one cycle from when a user starts to press the fifth region Ar5 to when the user stops pressing the fifth region Ar5, the second row sensor 12b outputs a third signal having a positive polarity with respect to the reference potential VE, and then outputs a third signal having a negative polarity with respect to the reference potential VE. For example, in one cycle from when the user starts pressing the sixth area Ar6 to when he finishes, the second column sensor 12b outputs a third signal having a negative polarity with respect to the reference potential VE, and then outputs a third signal having a positive polarity with respect to the reference potential VE.

[0029] The arithmetic circuit 13 is, for example, a microcontroller including a CPU, a ROM, and a 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 executes a process (hereinafter referred to as process U) to identify the position where the elastic member 10 has deformed based on the first signal Sig1, the second signal, and the third signal. Process U will be described below with reference to the drawings. FIG. 6 is a flowchart showing an example of process U executed by the arithmetic circuit 13.

[0030] For example, the arithmetic circuit 13 starts the process U when it receives the first signal Sig1, the second signal, and the third signal (START in FIG. 6). After the start, the arithmetic circuit 13 determines the polarity of the first signal Sig1 with respect to the reference potential VE (hereinafter referred to as the first polarity), the polarity of the second signal with respect to the reference potential VE (hereinafter referred to as the second polarity), and the polarity of the third signal with respect to the reference potential VE (hereinafter referred to as the third polarity) (step S11 in FIG. 6).

[0031] Next, the arithmetic circuit 13 identifies the position where the elastic member 10 has deformed based on the first polarity, the second polarity, and the third polarity (FIG. 6: step S12). The following describes an example in which the user presses the area ArID shown in FIG. 2. The area ArID is located on the first main surface UF10 on the negative side of the X-axis from the line SL1, and is located between the lines SL2 and SL3.

[0032] In this case, the first row sensor 11a outputs a first signal Sig1 having a positive polarity with respect to the reference potential VE, and then outputs a first signal Sig1 having a negative polarity with respect to the reference potential VE. Therefore, when the arithmetic circuit 13 receives a first signal Sig1 having a positive polarity with respect to the reference potential VE, and then receives a first signal Sig1 having a negative polarity with respect to the reference potential VE, the arithmetic circuit 13 determines that the area pressed by the user on the first principal surface UF10 is located within the first area Ar1.

[0033] Similarly, the first column sensor 12a outputs a second signal having a negative polarity with respect to the reference potential VE, and then outputs a second signal having a positive polarity with respect to the reference potential VE. Therefore, when the arithmetic circuit 13 receives a second signal having a negative polarity with respect to the reference potential VE, and then receives a second signal having a positive polarity with respect to the reference potential VE, the arithmetic circuit 13 determines that the area of ​​the first main surface UF10 pressed by the user is located within the fourth area Ar4.

[0034] Similarly, the second column sensor 12b outputs a third signal having a positive polarity with respect to the reference potential VE, and then outputs a third signal having a negative polarity with respect to the reference potential VE. Therefore, when the arithmetic circuit 13 receives a third signal having a positive polarity with respect to the reference potential VE, and then receives a third signal having a negative polarity with respect to the reference potential VE, the arithmetic circuit 13 determines that the area of ​​the first main surface UF10 pressed by the user is located within the fifth area Ar5.

[0035] In the above case, the arithmetic circuit 13 determines that the area pressed by the user on the first principal surface UF10 is an area that satisfies the conditions that the area is located within the first area Ar1, the fourth area Ar4, and the fifth area Ar5. Because the area ArID satisfies these conditions, the arithmetic circuit 13 identifies the area ArID that satisfies these conditions as the area pressed by the user.

[0036] By executing the processes of steps S11 and S12, the arithmetic circuit 13 completes the process U (FIG. 6: END).

[0037] (effect) According to the position detection device 1, it is easy to reduce the cost of the position detection device 1. Below, the position detection device 1 will be described by comparing it with the position detection device described in Patent Document 1. In the position detection device described in Patent Document 1, the arithmetic circuit identifies the position on the protective layer touched by the user based on the voltage generated by the piezoelectric element. In this case, the piezoelectric element needs to overlap the entire surface of the protective layer when viewed in the direction in which the protective layer, stripe electrode, piezoelectric element, and single electrode are aligned. Therefore, the position detection device described in Patent Document 1 needs to include a piezoelectric element that is approximately the same size as the entire surface of the protective layer in order to identify the position on the protective layer touched by the user. Therefore, it is difficult to reduce the size of the piezoelectric element in the position detection device described in Patent Document 1. Therefore, it is difficult to reduce the cost of the position detection device described in Patent Document 1.

[0038] Meanwhile, the position detection device 1 includes a first row sensor 11a having an end E11a overlapping the outer edge of the first main surface UF10, a first column sensor 12a having an end E12a overlapping the outer edge of the first main surface UF10, and a second column sensor 12b having an end E12b overlapping 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 shown in FIG. 2, the position detection device 1 can identify which of the first to sixth regions Ar1 to Ar6 has deformed. Therefore, the position detection device 1 can identify the position of deformation in the elastic member 10 without including sensors provided on the entire surface of the elastic member 10. Therefore, compared to the position detection device according to Comparative Example 1, the area of ​​the sensor can be easily reduced, and therefore the cost of the position detection device 1 can be easily reduced.

[0039] [Variation 1] Hereinafter, a position detection device 1a according to Modification 1 will be described with reference to the drawings. Fig. 7 is a diagram showing a position detection device 1a according to Modification 1 of the position detection device 1. Note that, in the configuration of the position detection device 1a, only parts that are different from the configuration of the position detection device 1 will be described, and descriptions of parts that are the same as the configuration of the position detection device 1 will be omitted.

[0040] 7, in the position detection device 1a, each of the plurality of sensors 11 is provided on the second principal surface DF10. Such a position detection device 1a has the same effects as the position detection device 1.

[0041] [Variation 2] Hereinafter, a position detection device 1b according to Modification 2 will be described with reference to the drawings. Fig. 8 is a diagram showing a position detection device 1b according to Modification 2 of the position detection device 1.

[0042] 8, the position detection device 1b differs from the position detection device 1 in that it further includes a sensor 14a that does not overlap with the outer edge of the first main surface UF10. Therefore, in this modification, the multiple sensors 11 further include a sensor 14a (first sensor).

[0043] The sensor 14a includes a piezoelectric film 141a (third piezoelectric film). The piezoelectric film 141a is uniaxially stretched and has piezoelectricity in which molecules are oriented in an orientation direction OD4a (third orientation direction). The sensor 14a is disposed so that the orientation direction OD4a is parallel to the third direction DIR3. When viewed in the first direction DIR1, the sensor 14a overlaps with a straight line SL1 (first straight line).

[0044] In this modification, the sensor 14a is located between two adjacent sensors among the first to n-th row sensors when viewed in the second direction DIR2. In this modification, n is 2. Therefore, the multiple sensors 11 include the adjacent first row sensor 12a and second row sensor 12b. Therefore, the sensor 14a is located between the first row sensor 12a and the second row sensor 12b when viewed in the second direction DIR2. In this modification, as shown in FIG. 8, the sensor 14a is located between the lines SL2 and SL3 when viewed in the Z-axis direction.

[0045] The arithmetic circuit 13 identifies the position where the elastic member 10 is deformed based on the first signal Sig1, the second signal, the third signal, and the fourth signal output by the sensor 14a.

[0046] (effect) For example, when the end of the first region Ar1 in the negative direction of the Y-axis is deformed, the sensor 14a is more likely to deform than the first row sensor 11a. Therefore, the value of the fourth signal output by the sensor 14a is more likely to be larger than the value of the first signal Sig1. As a result, the arithmetic circuit 13 can easily identify the deformation of the end of the first region Ar1 in the negative direction of the Y-axis by identifying the position of the deformation of the elastic member 10 based on the first signal Sig1 and the fourth signal. As a result, the position detection device 1a makes it easier for the arithmetic circuit 13 to identify the position of the deformation of the elastic member 10.

[0047] [Variation 3] Hereinafter, a position detection device 1c according to Modification 3 will be described with reference to the drawings. Figure 9 is a diagram showing a position detection device 1c according to Modification 3 of the position detection device 1.

[0048] The position detection device 1c differs from the position detection device 1 in that it includes a sensor where m is a natural number greater than or equal to 2. In the example shown in FIG. 9, m is 2. Therefore, in this modification, the multiple sensors 11 further include a second-row sensor 11b. The second-row sensor 11b is located on the negative side of the X-axis relative to the first-row sensor 11a.

[0049] The second row sensor 11b includes a piezoelectric film 111b (first piezoelectric film). The piezoelectric film 111b is uniaxially stretched and has piezoelectricity in which molecules are oriented in an orientation direction OD1b (first orientation direction). The second row sensor 11b is arranged such that the orientation direction OD1b is parallel to the third direction DIR3.

[0050] Here, a straight line SL4 (first straight line) parallel to the third direction DIR3 and overlapping with the second row sensor 11b when viewed in the Z-axis direction (first direction DIR1) is defined. In this case, the polarity of the signal output by the second row sensor 11b when an area on the first principal surface UF10 located on the negative side of the X-axis from the straight line SL4 is deformed is different from the polarity of the signal output by the second row sensor 11b when an area on the first principal surface UF10 located on the positive side of the X-axis from the straight line SL4 is deformed. The other configuration of the second row sensor 11b is the same as that of the first row sensor 11a, and therefore description thereof will be omitted.

[0051] The position detection device 1c also differs from the position detection device 1 in that it further includes a sensor 15a (second sensor) that does not overlap the outer edge of the first main surface UF10 (see FIG. 9). Therefore, in this modification, the multiple sensors 11 further include a sensor 15a (second sensor).

[0052] The sensor 15a includes a piezoelectric film 151a (fourth piezoelectric film). The piezoelectric film 151a is uniaxially stretched and has piezoelectricity in which molecules are aligned in an alignment direction OD5a (fourth alignment direction). The sensor 15a is disposed so that the alignment direction OD5a is parallel to the second direction DIR2. In this modification, the sensor 15a overlaps with a straight line SL2 (second straight line) when viewed in the first direction DIR1.

[0053] In this modification, the sensor 15a is located between two adjacent sensors among the first row sensors to the m-th row sensors, as viewed in the third direction DIR3. In this modification, the multiple sensors 11 include the first row sensor 11a and the second row sensor 11b, which are adjacent to each other. Therefore, the sensor 15a is located between the first row sensor 11a and the second row sensor 11b, as viewed in the third direction DIR3. The other configuration of the sensor 15a is the same as the configuration of the first column sensor 12a, so a description thereof will be omitted.

[0054] In this modified example, the calculation circuit 13 determines the position at which the elastic member 10 is deformed based on the first signal Sig1, the second signal, and the third signal, as well as the signal output by the second row sensor 11b and the signal output by the sensor 15a.

[0055] (effect) 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. Meanwhile, the position detection device 1c further includes a second row sensor 11b in addition to the first row sensor 11a, the first column sensor 12a, and the second column sensor 12b. In this case, the first main surface UF10 is divided into nine regions by the multiple straight lines on the first main surface UF10. In other words, compared to the position detection device 1, in the position detection device 1c, the region on the first main surface UF10 where deformation is identified by the arithmetic circuit 13 is subdivided. This improves the accuracy with which the arithmetic circuit 13 identifies the position of deformation of the elastic member 10.

[0056] For example, when the end of the third region Ar3 in the negative direction of the X-axis is deformed, the sensor 15a is more likely to deform than the second-row sensor 12b. Therefore, the magnitude of the value of the signal output by the sensor 15a is more likely to be larger than the magnitude of the value of the second signal. As a result, the arithmetic circuit 13 can easily identify the deformation of the end of the third region Ar3 in the negative direction of the X-axis by identifying the position of the deformation of the elastic member 10 based on the second signal and the signal output by the sensor 15a. As a result, the position detection device 1c makes it easier for the arithmetic circuit 13 to identify the position of the deformation of the elastic member 10.

[0057] The position detection device 1c further includes a sensor 15a. The sensor 15a is located between two adjacent sensors among the first through m-th row sensors as viewed in the third direction DIR3. In this case, as shown in FIG. 9, the sensor 15a is located closer to the center of the first main surface UF10 than the first through m-th row sensors and the first through n-th column sensors. Therefore, the sensor 15a can more easily detect deformation near the center of the first main surface UF10 than the first through m-th row sensors and the first through n-th column sensors. Therefore, the position detection device 1c makes it easier for the arithmetic circuit 13 to identify the position where the elastic member 10 is deformed.

[0058] [Variation 4] A position detection device 1d according to Modification 4 will be described below with reference to the drawings. Fig. 10 is a diagram showing a position detection device 1d according to Modification 4 of the position detection device 1.

[0059] 10, the position detection device 1d differs from the position detection device 1 in that it includes a second row sensor 11b and a third row sensor 11c in addition to the first row sensor 11a. The positions of the first row sensor 11a, the second row sensor 11b, and the third row sensor 11c in the second direction DIR2 are aligned in this order in the second direction DIR2.

[0060] In this modification, as viewed in the first direction DIR1, ends (first ends) of some of the first to m-th row sensors in the third direction DIR3 overlap the outer edge of the first main surface UF10. As viewed in the first direction DIR1, ends (first ends) of the remaining first to m-th row sensors in the fifth direction DIR5 overlap the outer edge of the first main surface UF10. For example, as shown in FIG. 10 , as viewed in the first direction DIR1, an end E11a of the first row sensor 11a (some of the first to m-th row sensors) in the third direction DIR3 overlaps the first side H1. As viewed in the first direction DIR1, an end E11b of the second row sensor 11b (the remaining first to m-th row sensors) in the fifth direction DIR5 overlaps the second side H2. As viewed in the first direction DIR1, an end E11c of the third row sensor 11c (the remaining first to m-th row sensors) in the fifth direction DIR5 overlaps with the second side H2. Other configurations of the second row sensor 11b are the same as those of the first row sensor 11a, and therefore descriptions thereof will be omitted. Other configurations of the third row sensor 11c are the same as those of the first row sensor 11a, and therefore descriptions thereof will be omitted.

[0061] The position detection device 1d also differs from the position detection device 1 in that it includes a third row sensor 12c in addition to the first row sensor 12a and the second row sensor 12b. The positions of the first row sensor 12a, the second row sensor 12b, and the third row sensor 12c in the third direction DIR3 are aligned in this order in the third direction DIR3.

[0062] In this modification, as viewed in the first direction DIR1, ends (second ends) of some of the first through n-th row sensors in the second direction DIR2 overlap the outer edge of the first main surface UF10. As viewed in the first direction DIR1, ends (second ends) of the remaining first through n-th row sensors in the fourth direction DIR4 overlap the outer edge of the first main surface UF10. For example, as shown in FIG. 10 , as viewed in the first direction DIR1, an end E12a of the first row sensor 12a (the first through n-th row sensors) in the second direction DIR2 and an end E12b of the second row sensor 12b (the first through n-th row sensors) in the second direction DIR2 overlap the fourth side H4. As viewed in the first direction DIR1, an end E12c of the third row sensor 12c (the remaining portion of the first row sensor to the nth row sensor) in the fourth direction DIR4 overlaps with the third side H3. The other configuration of the third row sensor 12c is the same as the configuration of the first row sensor 12a, so a description thereof will be omitted.

[0063] (effect) Such a position detection device 1d has the same effects as the position detection device 1.

[0064] [Variation 5] A position detection device 1e according to Modification 5 will be described below with reference to the drawings. Fig. 11 is a diagram showing a position detection device 1e according to Modification 5 of the position detection device 1.

[0065] The position detection device 1e differs from the position detection device 1c in that it has two first row sensors 11a, 11a2, two second row sensors 11b, 11b2, two first column sensors 12a, 12a2, and two second column sensors 12b, 12b2.

[0066] The first row sensor 11a2 overlaps the line SL1 when viewed in the Z-axis direction. An end of the first row sensor 11a2 in the fifth direction DIR5 overlaps the second side H2. The other configurations of the first row sensor 11a2 are the same as those of the first row sensor 11a, and therefore, description thereof will be omitted.

[0067] The second row sensor 11b2 overlaps the line SL4 when viewed in the Z-axis direction. The end of the second row sensor 11b2 in the fifth direction DIR5 overlaps the second side H2. The other configuration of the second row sensor 11b2 is the same as the configuration of the first row sensor 11a, so a description thereof will be omitted.

[0068] The first row sensor 12a2 overlaps with the straight line SL2 when viewed in the Z-axis direction. The end of the first row sensor 12a2 in the fourth direction DIR4 overlaps with the third side H3. The other configuration of the first row sensor 12a2 is the same as that of the first row sensor 12a, so a description thereof will be omitted.

[0069] The second row sensor 12b2 overlaps with the straight line SL3 when viewed in the Z-axis direction. The end of the second row sensor 12b2 in the fourth direction DIR4 overlaps with the third side H3. The other configuration of the second row sensor 12b2 is the same as the configuration of the first row sensor 12a, so a description thereof will be omitted.

[0070] Furthermore, the position detection device 1e differs from the position detection device 1c in that it includes a sensor 14a (first sensor), a sensor 14b (first sensor), and a sensor 15b (second sensor) that do not overlap the outer edge of the elastic member 10 when viewed in the Z-axis direction. The sensor 14a in the position detection device 1e is the same as the sensor 14a in the position detection device 1b, and therefore a description thereof will be omitted.

[0071] 11, sensor 14b is located between first row sensor 12a and second row sensor 12b when viewed in the second direction DIR2. Sensor 14b overlaps with line SL4 when viewed in the Z-axis direction. The other configuration of sensor 14b is the same as that of sensor 14a, so a description thereof will be omitted.

[0072] Sensor 15b is located between first row sensor 11a and second row sensor 11b when viewed in the third direction DIR3. Sensor 15b overlaps with line SL3 when viewed in the Z-axis direction. The other configuration of sensor 15b is the same as that of sensor 15a, so a description thereof will be omitted.

[0073] In the example shown in FIG. 11, the first main surface UF10 of the elastic member 10 is divided into nine regions from region Ar1a to region Ar9a by the twelve sensors 11, in the same manner as in the first embodiment.

[0074] Such a position detection device 1e has the same effects as the position detection device 1 and the same effects as the position detection devices 1a to 1d.

[0075] [Variation 6] A position detection device 1f according to Modification 6 will be described below with reference to Figs. 11 to 14. Fig. 12 is a diagram showing experimental results Re1 obtained through experiments by the inventors of the present application. Fig. 13 is a diagram showing experimental results Re2 obtained through experiments by the inventors of the present application. Fig. 14 is a diagram showing experimental results Re3 obtained through experiments by the inventors of the present application.

[0076] The position detection device 1f differs from the position detection device 1 in that it identifies the position where the elastic member 10 is deformed based on a machine learning algorithm.

[0077] The inventor of the present application has found through experiments that there is a relationship between the cross-correlation coefficient of the signal values ​​output by each of two sensors out of the plurality of sensors 11 and the position where the elastic member 10 has been deformed. Therefore, the inventor of the present application has found that it is possible to identify the position where the elastic member 10 has been deformed based on this relationship. This will be explained in detail below.

[0078] The inventors of the present application conducted the following experiment using the position detection device 1f shown in FIG. 11. When the elastic member 10 is deformed, the cross-correlation coefficient of the signal values ​​output by each of two sensors among the multiple sensors 11 is calculated. In the example shown in FIG. 11, for example, a region located on the negative side of the Y-axis from line SL3 and on the negative side of the X-axis from line SL4 is pressed. At this time, for example, the cross-correlation coefficient (first cross-correlation coefficient) between the signal value output by the first row sensor 11a among the multiple sensors 11 and the signal value output by sensor 15a is calculated. For example, the first cross-correlation coefficient is obtained by multiplying the signal value output by the first row sensor 11a by the signal value output by sensor 15a. In this case, the first cross-correlation coefficient indicates the strength of the correlation between the signal value output by the first row sensor 11a and the signal value output by sensor 15a. Similar calculations are performed for all combinations of two sensors among the multiple sensors 11. This allows multiple cross-correlation coefficients to be obtained.

[0079] Next, the inventors performed principal component analysis on the multiple cross-correlation coefficients. Principal component analysis is an example of unsupervised learning. Principal component analysis is a method for identifying a number of principal components according to the type of data based on the variance (variance) of the multiple data being analyzed. For example, the principal component scores of the first and second principal components, which are the major principal components, are plotted on a two-dimensional graph consisting of an axis of the first principal component and an axis of the second principal component. This makes it possible to reduce three- or more-dimensional feature quantities contained in the multiple data to two-dimensional feature quantities. The inventors performed principal component analysis on the multiple cross-correlation coefficients to obtain the results shown in FIG. 12.

[0080] Similarly, the inventors of the present application analyzed multiple cross-correlation coefficients using the t-SNE method to obtain the results shown in FIG. 13. The t-SNE method is a commonly used method, so a detailed explanation will be omitted. Similarly, the inventors of the present application analyzed multiple cross-correlation coefficients using the umap method to obtain the results shown in FIG. 14. The umap method is a commonly used method, so a detailed explanation will be omitted.

[0081] The present inventors considered the experimental results shown in FIGS. 12, 13, and 14. As a result, the present inventors noticed that the positions where the multiple cross-correlation coefficients are plotted in each of FIGS. 12, 13, and 14 have characteristics. Specifically, the present inventors noticed that the multiple cross-correlation coefficients can be divided into nine groups CL1 to CL9 based on the positions where the multiple cross-correlation coefficients are plotted. Here, in the position detection device 1f used in the experiment, the first main surface UF10 of the elastic member 10 is divided into nine regions Ar1a to Ar9a by the 12 sensors 11. In other words, the number of groups in FIGS. 12, 13, and 14 matches the number of regions on the first main surface UF10. From this, the present inventors noticed that there is a relationship between the multiple cross-correlation coefficients and the position where the elastic member 10 is deformed.

[0082] From the above, the inventors of the present application came up with a method of storing a learning model in the arithmetic circuit 13, which has previously learned the relationship between multiple cross-correlation coefficients and the position where the elastic member 10 has been deformed. The learning model is previously trained based on training data that indicates the relationship between multiple cross-correlation coefficients and the position where the elastic member 10 has been deformed. The learning model receives input values ​​of multiple cross-correlation coefficients. The learning model estimates the position where the elastic member 10 has been deformed based on the values ​​of the multiple cross-correlation coefficients. The arithmetic circuit 13 corrects the learning model based on the estimation results. This improves the accuracy with which the arithmetic circuit 13 identifies the position where the elastic member 10 has been deformed.

[0083] [Variation 7] A position detection device 1g according to Modification 7 will be described below with reference to Fig. 11. In the position detection device 1g, the arithmetic circuit 13 identifies the position where the elastic member 10 is deformed by using multiple regression analysis.

[0084] The magnitude of the output value of each of the multiple sensors 11 depends on the amount of displacement of the position (hereinafter referred to as the sensor position) at which the multiple sensors 11 are provided on the elastic member 10. For example, the magnitude of the value of the signal output by the first row sensor 11a depends on the amount of displacement of the position at which the first row sensor 11a is provided on the elastic member 10. Furthermore, the magnitude of the output of each of the multiple sensors 11 depends on the position at which 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 of the elastic member 10 in the negative direction of the Y axis is deformed is smaller than the magnitude of the signal value output by the first row sensor 11a when the end of the elastic member 10 in the positive direction of the Y axis is deformed. The same applies to sensors other than the first row sensor 11a in the multiple sensors 11. In this case, the relationship shown in Determinant 1 below holds between the output values ​​of the multiple sensors 11, the amount of displacement of the sensor position, and the position at which the elastic member 10 is deformed.

[0085]

number

[0086] In the determinant 1, the sensor output value is the maximum value of each signal output by the multiple sensors 11 when the elastic member 10 is deformed. In the example shown in FIG. 11, the number of sensors 11 is 12. Therefore, the number of columns of matrix Y, the number of rows of output transformation matrix P, the number of columns of output transformation matrix P, and the number of columns of matrix Q are each 12. In the example shown in FIG. 11, the first principal surface UF10 of the elastic member 10 is divided into 9 regions by the 12 multiple sensors 11, as in the first embodiment. Therefore, the number of rows of matrix Q and the number of columns of matrix X are each 9. The output transformation matrix P is a coefficient obtained by performing a multiple regression analysis in advance on the positions where the elastic member 10 is deformed and the signals output by each of the multiple sensors 11. The output transformation matrix P changes depending on how each of the multiple sensors 11 is attached, and the twisting and bending of each of the multiple sensors 11. The output transformation matrix P × matrix Q (output transformation matrix × change in sensor position) can be calculated using machine learning. The output transformation matrix P×matrix Q is obtained by calculating the relationship between each of the plurality of sensors 11 and the position where the elastic member 10 is deformed as a multiple regression model.

[0087] By substituting matrix A = output transformation matrix P × matrix Q into determinant 1, determinant 2 shown below is established. From determinant 2, determinant 3 is established.

[0088]

number

[0089]

number

[0090] From determinant 3, the position where the elastic member 10 is deformed is determined by adding the matrix A to the value of the signals output by each of the multiple sensors 11. -1 Therefore, the calculation circuit 13 multiplies the values ​​of the signals output from the plurality of sensors 11 by the matrix A. -1 The position where the elastic member 10 is deformed can be identified based on the value obtained by multiplying the matrix A by the matrix A (first matrix).-1 is calculated based on the output transformation matrix P × matrix Q obtained by multiple regression analysis. -1 (First matrix) is a generalized inverse matrix of matrix A (second matrix) based on coefficients obtained by multiple regression analysis of the positions where the elastic member 10 is deformed and the signals output by each of the multiple sensors 11.

[0091] (effect) In this modification, the arithmetic circuit 13 identifies the position where the elastic member 10 has deformed based on an output transformation matrix P × matrix Q that is obtained in advance by machine learning. In this case, the values ​​included in the output transformation matrix P × matrix Q are values ​​that take into account noise that occurs in the signals output by the multiple sensors 11. Therefore, when identifying the position where the elastic member 10 has deformed, the arithmetic circuit 13 is less susceptible to the influence of noise that occurs in the signals output by the multiple sensors 11. As a result, the possibility that the arithmetic circuit 13 will erroneously identify the position where the elastic member 10 has deformed is reduced.

[0092] [Variation 8] A position detection device 1h according to Modification 8 will be described below with reference to Fig. 11. The position detection device 1h identifies the position where the elastic member 10 is deformed by using a matrix based on the cross-correlation coefficient.

[0093] As explained in Modification 6, there is a relationship between the multiple cross-correlation coefficients and the position where the elastic member 10 is deformed. Therefore, the following determinant 4 holds. Furthermore, from determinant 4, determinant 5 holds.

[0094]

number

[0095]

number

[0096] From determinant 5, the calculation circuit 13 calculates matrix S by adding matrix B to matrix S. -1Based on the value obtained by multiplying the value by the value of the elastic member 10, it is possible to identify the position where the elastic member 10 has been deformed. Such a position detection device 1h has the same effect as the position detection device 1g.

[0097] [Variation 9] The position detection device 1i according to the ninth modification will be described below with reference to FIG. -1 and matrix A -1 The position where the elastic member 10 is deformed is identified based on a matrix other than the matrix.

[0098] Specifically, similarly to Modification 6, the arithmetic circuit 13 calculates a cross-correlation coefficient between two of the multiple sensors 11 based on the signals output from each of the multiple sensors 11. The arithmetic circuit 13 performs this calculation for all combinations of two sensors among the multiple sensors 11. As a result, the following determinant 6 can be obtained. Furthermore, from determinant 6 and determinant 2, the following determinant 7 is established. Furthermore, from determinant 7, the following determinant 8 is established.

[0099]

number

[0100]

number

[0101]

number

[0102] The calculation circuit 13 identifies the position where the elastic member 10 is deformed based on the determinant 8. Specifically, the calculation circuit 13 calculates the matrix A -1 (1st matrix), transpose matrix A based on matrix A t , and matrix XX based on matrix B (third matrix) t Therefore, in this modification, the calculation circuit 13 calculates the matrix A -1(first matrix), matrix A (second matrix) and matrix B (third matrix) based on matrix XX t (fourth matrix). The calculation circuit 13 calculates the matrix XX t (fourth matrix). Specifically, the calculation circuit 13 calculates the position where the elastic member 10 is deformed based on the matrix XX t The position where the elastic member 10 is deformed is identified by calculating the matrix X from the matrix XX. t Each of one or more diagonal elements in (the fourth matrix) has a value related to the position where the elastic member 10 is deformed.

[0103] (effect) In the position detection device 1i, the arithmetic circuit 13 identifies the position where the elastic member 10 has deformed based on artificial intelligence, similar to the arithmetic circuit 13 in the position detection device 1g. Therefore, similar to the position detection device 1f, the arithmetic circuit 13 of the position detection device 1i is less likely to erroneously identify the position where the elastic member 10 has deformed.

[0104] [Other variations] The position detection devices 1, 1a to 1i according to the present invention are not limited to the above, and may be modified within the scope of the gist thereof. Furthermore, the configurations of the position detection devices 1, 1a to 1i may be combined in any manner.

[0105] The X-axis, Y-axis, and Z-axis directions are defined for the purpose of explanation only, and therefore the X-axis, Y-axis, and Z-axis directions when the position detection device is actually used do not necessarily have to match the X-axis, Y-axis, and Z-axis directions in each embodiment and each modified example.

[0106] 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 during actual use of the position detection device do not necessarily coincide with the first direction DIR1, the second direction DIR2, the third direction DIR3, the fourth direction DIR4, and the fifth direction DIR5 in each embodiment and each modified example. For example, the positive direction of the Z axis may coincide with the first direction DIR1.

[0107] Each of the multiple sensors 11 may be provided on either the first main surface UF10 or the second main surface DF10. Therefore, in the position detection device 1, the first row sensor 11a may be provided on the first main surface UF10, and the first column sensor 12a and the second column sensor 12b may be provided on the second main surface DF10.

[0108] The piezoelectric film of each of the plurality of sensors 11 does not necessarily have to be PLLA, but may be PVDF.

[0109] The piezoelectric film of each of the plurality of sensors 11 does not necessarily have to be an organic piezoelectric material such as PLLA, but may be an inorganic piezoelectric material such as PZT.

[0110] It should be noted that the first electrode 110a does not necessarily have to be a reference electrode, and the second electrode 112a does not necessarily have 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.

[0111] In the position detection device 1c, the sensor 15a may overlap with the straight line SL3 (second straight line). In this case, the second straight line overlaps with any one of the first row sensors to the n-th row sensors when viewed in the first direction DIR1, and the second sensor overlaps with the second straight line when viewed in the first direction DIR1.

[0112] The multiple sensors 11 in the position detection device 1c may include a sensor 14a (first sensor). In this case, the sensor 14a may overlap with the line SL1 (first line) or the line SL4 (first line). In this case, the first line overlaps with any one of the first row sensors to the m-th row sensors when viewed in the first direction DIR1, and the first sensor overlaps with the first line when viewed in the first direction DIR1.

[0113] 1 and 2, the end E11a is disposed on the first side H1 so as to form an angle of 0 degrees with respect to the first side H1. However, the end E11a may be disposed on the first side H1 so as to form an angle of approximately 0 degrees±10 degrees with respect to the first side H1. The same applies to the ends other than the end E11a (ends E12a, E12b, etc.).

[0114] 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.).

[0115] The number of sensors can be changed depending on the number of regions on the first main surface UF10 where the arithmetic circuit 13 detects deformation. Specifically, when the arithmetic circuit 13 detects deformation in each of x×y (x is a natural number greater than or equal to 2) regions on the first main surface UF10, the number of sensors is (x−1)+(y−1). For example, as shown in FIG. 2, when the arithmetic circuit 13 detects deformation in each of 2×3 regions, the number of sensors is 3(1+2). Therefore, as shown in FIG. 2, the position detection device 1 only needs to include three sensors: a first row sensor 11a, a first column sensor 12a, and a second column sensor 12b.

[0116] In the position detection device 1f, the arithmetic circuit 13 does not necessarily need to identify the position where the elastic member 10 has been deformed by principal component analysis. The arithmetic circuit 13 may identify the position where the elastic member 10 has been deformed by executing a method other than principal component analysis based on the relationship between a plurality of cross-correlation coefficients and the position where the elastic member 10 has been deformed. For example, the arithmetic circuit 13 may identify the position where the elastic member 10 has been deformed by a method using a teacher signal, such as a decision tree or a random forest. For example, the arithmetic circuit 13 may identify the position where the elastic member 10 has been deformed based on an algorithm based on supervised learning, such as SVM.

[0117] An electronic device such as a smartphone is equipped with the position detection device 1. In this case, for example, the top surface of the case of the electronic device corresponds to the elastic member 10. At this time, the user presses the top surface of the case, which causes the case to deform. As a result, the position detection device 1 can identify the position of deformation on the top surface of the case.

[0118] The bottom surface of the case of the electronic device may correspond to the elastic member 10. At this time, the user presses the bottom surface of the case, for example, with the user's ring finger, little finger, etc. while holding the case. This deforms the bottom surface of the case. As a result, the position detection device 1 can identify the position of the deformation on the bottom surface of the case. For example, the user presses the bottom surface of the case with a finger while operating the screen of an electronic device such as a smartphone. In this case, the electronic device is configured to execute processing based on the user's operation on the bottom surface of the case in addition to the user's operation on the screen. The side surface of the case of the electronic device may correspond to the elastic member 10.

[0119] The positive and negative polarities in the X-axis direction or the Y-axis direction do not have to match the positive and negative polarities 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 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 positive or negative. The same applies to the positive and negative polarities of the second signal output by the first column sensor 12a or the third signal output by the second column sensor 12b.

[0120] The present invention has the following structure:

[0121] (1) an elastic member having a first main surface and a second main surface aligned in a first direction; A plurality of sensors; It is equipped with Each of the plurality of sensors is provided on the first main surface or the second main surface, The plurality of sensors include: a first row sensor to an m-th row sensor having a first end overlapping an outer edge of the first main surface or the second main surface; first to n-th row sensors each having a second end overlapping an outer edge of the first main surface or the second main surface; It contains Each of the m and the n is a natural number, The third direction intersects with the second direction, the first ends are either ends of the first row sensors to the mth row sensors in the third direction or in a direction opposite to the third direction, when viewed in the first direction; the second ends are either ends of the first row sensors to the nth row sensors in the second direction or ends in a direction opposite to the second direction, when viewed in the first direction; the positions of the first row sensors to the m-th row sensors in the second direction are aligned in this order in the second direction; the positions of the first row sensors to the n-th row sensors in the third direction are aligned in this order in the third direction; Each of the first row sensors to the mth row sensors includes a first piezoelectric film that is uniaxially stretched and has piezoelectricity in which molecules are oriented in a first orientation direction, and is arranged so that the first orientation direction is parallel to the third direction; Each of the first row sensors to the nth row sensors includes a second piezoelectric film that is uniaxially stretched and has piezoelectricity in which molecules are oriented in a second orientation direction, and is arranged so that the second orientation direction is parallel to the second direction. Position detection device.

[0122] (2) each of m and n is a natural number of 2 or more; When viewed in the first direction, the first ends in the third direction of some of the first row sensors to the mth row sensors overlap an outer edge of the first main surface or the second main surface, When viewed in the first direction, the first ends of the remaining portions of the first row sensors to the mth row sensors in a direction opposite to the third direction overlap with an outer edge of the first main surface or the second main surface, When viewed in the first direction, the second ends in the second direction of some of the first row sensors to the nth row sensors overlap an outer edge of the first main surface or the second main surface, When viewed in the first direction, the second ends of the remaining parts of the first row sensors to the nth row sensors in the direction opposite to the second direction overlap with an outer edge of the first main surface or the second main surface. A position detection device according to (1).

[0123] (3) the plurality of sensors further includes a first sensor; the first sensor includes a third piezoelectric film that is uniaxially stretched and has piezoelectricity in which molecules are oriented in a third orientation direction, and is disposed so that the third orientation direction is parallel to the third direction; a first straight line is parallel to the third direction and overlaps with any one of the first row sensors to the m-th row sensors when viewed in the first direction; the first sensor overlaps with the first straight line when viewed in the first direction; A position detection device according to (1) or (2).

[0124] (4) The n is a natural number of 2 or more, the first sensor is located between two adjacent sensors among the first row sensors to the nth row sensors when viewed in the second direction; (3) A position detection device according to the present invention.

[0125] (5) the plurality of sensors further includes a second sensor; the second sensor includes a fourth piezoelectric film that is uniaxially stretched and has piezoelectricity in which molecules are oriented in a fourth orientation direction; the second sensor is disposed such 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 row sensors to the nth row sensors when viewed in the first direction; the second sensor overlaps with the second straight line when viewed in the first direction; A position detection device according to any one of (1) to (4).

[0126] (6) The m is a natural number of 2 or more, the second sensor is located between two adjacent sensors among the first row sensors to the mth row sensors when viewed in the third direction; (5) A position detection device according to (5).

[0127] (7) the position detection device further includes an arithmetic circuit, each of the plurality of sensors outputs a signal corresponding to the deformation of the elastic member; the arithmetic circuit identifies a position where the elastic member is deformed based on the signals output from each of the plurality of sensors. A position detection device according to any one of (1) to (6).

[0128] (8) the arithmetic circuit identifies the position where the elastic member has deformed based on a value obtained by multiplying the value of the signal output from each of the plurality of sensors by a first matrix. (7) A position detection device according to (7).

[0129] (9) the first matrix is ​​a generalized inverse matrix of the second matrix based on coefficients obtained by multiple regression analysis of the positions where the elastic member is deformed and the signals output from each of the plurality of sensors; (8) A position detection device according to (8).

[0130] (10) the calculation circuit calculates a cross-correlation coefficient between two of the plurality of sensors based on the signals output from each of the plurality of sensors; the calculation circuit calculates a third matrix based on the cross-correlation coefficients; the calculation circuit calculates a fourth matrix based on the first matrix, the second matrix, and the third matrix; the arithmetic circuit identifies the position where the elastic member is deformed based on the fourth matrix. (9) A position detection device according to (9).

[0131] (11) Each of one or more diagonal elements in the fourth matrix has a value related to a position where the elastic member is deformed. (10) A position detection device according to (10). [Explanation of symbols]

[0132] 1, 1a to 1g: Position detection device 10: Elastic member 11: Multiple sensors 11a, 11a2: first row sensor 11b, 11b2: second row sensor 12a, 12a2: First row sensor 12b, 12b2: Second row sensors 111a, 111b, 121a, 121b: piezoelectric film UF10: First principal surface DF10: Second main surface E11a, E11b, E11c, E12a, E12b, E12c: Edge OD1a, OD1b, OD2a, OD2b, OD4a, OD5a: Orientation direction

Claims

1. an elastic member having a first main surface and a second main surface aligned in a first direction; A plurality of sensors; It is equipped with each of the plurality of sensors is provided on the first principal surface or the second principal surface; The plurality of sensors include: first to m-th row sensors each having a first end overlapping an outer edge of the first main surface or the second main surface; first to n-th row sensors each having a second end overlapping an outer edge of the first main surface or the second main surface; It contains Each of the m and the n is a natural number, the third direction intersects with the second direction; the first ends are either ends of the first row sensors to the mth row sensors in the third direction or in a direction opposite to the third direction, when viewed in the first direction; the second ends are either ends of the first row sensors to the nth row sensors in the second direction or ends in a direction opposite to the second direction, when viewed in the first direction; the positions of the first row sensors to the m-th row sensors in the second direction are aligned in this order in the second direction; the positions of the first row sensors to the n-th row sensors in the third direction are aligned in this order in the third direction, Each of the first row sensors to the mth row sensors includes a first piezoelectric film that is uniaxially stretched and has piezoelectricity in which molecules are oriented in a first orientation direction, and is arranged so that the first orientation direction is parallel to the third direction; Each of the first row sensors to the nth row sensors includes a second piezoelectric film that is uniaxially stretched and has piezoelectricity in which molecules are oriented in a second orientation direction, and is arranged so that the second orientation direction is parallel to the second direction. Position detection device.

2. each of m and n is a natural number of 2 or more; When viewed in the first direction, the first ends in the third direction of some of the first row sensors to the mth row sensors overlap an outer edge of the first main surface or the second main surface, When viewed in the first direction, the first ends of the remaining portions of the first row sensors to the mth row sensors in a direction opposite to the third direction overlap with an outer edge of the first main surface or the second main surface, When viewed in the first direction, the second ends in the second direction of some of the first row sensors to the nth row sensors overlap an outer edge of the first main surface or the second main surface, When viewed in the first direction, the second ends of the remaining parts of the first row sensors to the nth row sensors in a direction opposite to the second direction overlap with an outer edge of the first main surface or the second main surface. The position detection device according to claim 1 .

3. the plurality of sensors further includes a first sensor; the first sensor includes a third piezoelectric film that is uniaxially stretched and has piezoelectricity in which molecules are oriented in a third orientation direction, and is disposed 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 row sensors to the mth row sensors when viewed in the first direction; the first sensor overlaps with the first straight line when viewed in the first direction; 3. The position detection device according to claim 1 or 2.

4. The n is a natural number of 2 or more, the first sensor is located between two adjacent sensors among the first row sensors to the nth row sensors when viewed in the second direction; The position detection device according to claim 3 .

5. the plurality of sensors further includes a second sensor; the second sensor includes a fourth piezoelectric film that is uniaxially stretched and has piezoelectricity in which molecules are oriented in a fourth orientation direction; the second sensor is disposed such 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 row sensors to the nth row sensors when viewed in the first direction; the second sensor overlaps with the second straight line when viewed in the first direction; 3. The position detection device according to claim 1 or 2.

6. The m is a natural number of 2 or more, the second sensor is located between two adjacent sensors among the first row sensors to the mth row sensors when viewed in the third direction; The position detection device according to claim 5 .

7. the position detection device further includes an arithmetic circuit, each of the plurality of sensors outputs a signal corresponding to the deformation of the elastic member; the arithmetic circuit identifies a position where the elastic member is deformed based on the signals output from each of the plurality of sensors.

3. The position detection device according to claim 1 or 2.

8. the arithmetic circuit identifies the position where the elastic member has deformed based on a value obtained by multiplying the value of the signal output from each of the plurality of sensors by a first matrix. The position detection device according to claim 7.

9. the first matrix is ​​a generalized inverse matrix of the second matrix based on coefficients obtained by multiple regression analysis of the positions at which the elastic member is deformed and the signals output from each of the plurality of sensors; The position detection device according to claim 8.

10. the calculation circuit calculates a cross-correlation coefficient between two of the plurality of sensors based on the signals output from each of the plurality of sensors; the calculation circuit calculates a third matrix based on the cross-correlation coefficients; the calculation circuit calculates a fourth matrix based on the first matrix, the second matrix, and the third matrix; the arithmetic circuit identifies the position where the elastic member is deformed based on the fourth matrix. The position detection device according to claim 9.

11. Each of one or more diagonal elements in the fourth matrix has a value related to a position where the elastic member is deformed. The position detection device according to claim 10.

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