Deformation detection sensor and electronic apparatus

Abstract

This deformation detection sensor is provided with: a flexible substrate having a substrate upper main surface and a bending section; a first sensor that outputs a first detection signal corresponding to deformation of the bending section, is provided on the upper main surface of the substrate, and has a first upper main surface and a first lower main surface; a first deformation blocking member; and a second deformation blocking member. The first sensor includes a first piezoelectric film. The first deformation blocking member has a first region that overlaps the first piezoelectric thin film when viewed in the vertical direction. The second deformation blocking member has a second region that overlaps the first piezoelectric thin film when viewed in the vertical direction. The first region and the second region have portions that do not contact each other when viewed in the vertical direction in a state in which the flexible substrate is not bent.

Description

Technical Field

[0001] The present invention relates to a deformation detection sensor and an electronic device including the deformation detection sensor. Background Art

[0002] As an invention related to a conventional deformation detection sensor, for example, there is known a bending sensor described in Patent Document 1. The bending sensor includes: a piezoelectric element disposed on a bendable substrate; a voltage detection circuit that detects a voltage generated in the piezoelectric element; and a calculation unit that integrates the voltage detected by the voltage detection circuit to calculate an integral value and associates the integral value with a bending angle of the substrate.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: International Publication No. 2021 / 256252 Summary of the invention

[0006] Problem that the invention aims to solve

[0007] However, in the bending sensor described in Patent Document 1, it is desired to detect the bending angle of the substrate with high accuracy.

[0008] Therefore, an object of the present invention is to provide a deformation detection sensor and an electronic device capable of detecting a bending angle of a substrate with high accuracy.

[0009] Solutions for solving problems

[0010] A deformation detection sensor according to one aspect of the present invention includes:

[0011] A flexible substrate having a substrate upper main surface and a substrate lower main surface arranged in a vertical direction and a bending section that bends when bent at a bending line;

[0012] a first sensor that outputs a first detection signal corresponding to the deformation of the bending section, is provided on the upper main surface of the substrate, and has a first upper main surface and a first lower main surface arranged in the up-down direction;

[0013] a first deformation preventing member; and

[0014] The second deformation hindering member,

[0015] The first sensor comprises:

[0016] a first piezoelectric film having a first piezoelectric film upper principal surface and a first piezoelectric film lower principal surface arranged in the up-down direction;

[0017] a first upper electrode disposed on the upper main surface of the first piezoelectric film; and

[0018] a first lower electrode disposed on the lower main surface of the first piezoelectric film,

[0019] The first deformation preventing member is provided on the first upper main surface or the first lower main surface,

[0020] The first deformation preventing member has a first region overlapping with the first piezoelectric film when viewed in the up-down direction.

[0021] The second deformation preventing member is provided on the first upper main surface or the first lower main surface where the first deformation preventing member is provided,

[0022] The second deformation preventing member has a second region overlapping with the first piezoelectric film when viewed in the up-down direction.

[0023] The first region and the second region have portions that are not in contact with each other when viewed in the up-down direction in a state where the flexible base is not bent.

[0024] In this specification, directions are defined as follows. In the deformation detection sensor 1, the direction in which the substrate upper main surface US2 and the substrate lower main surface LS2 of the flexible substrate 2 are arranged is defined as the up-down direction. In addition, the direction in which the long side of the substrate upper main surface US2 extends when viewed in the up-down direction is defined as the left-right direction. The direction in which the short side of the substrate upper main surface US2 extends when viewed in the up-down direction is defined as the front-back direction. The up-down direction, the left-right direction, and the front-back direction are orthogonal to each other. In addition, in the deformation detection sensor 1, the direction in which the first piezoelectric film upper main surface US31 and the first piezoelectric film lower main surface LS31 of the first piezoelectric film 31 are arranged when the first piezoelectric film 31 is unfolded into a plane is defined as the piezoelectric film up-down direction. In addition, the direction in which the long side of the first piezoelectric film 31 extends when viewed in the piezoelectric film up-down direction is defined as the piezoelectric film left-right direction. The direction in which the short side of the first piezoelectric film 31 extends when viewed along the piezoelectric film up-down direction is defined as the piezoelectric film front-back direction. The piezoelectric film up-down direction, the piezoelectric film left-right direction, and the piezoelectric film front-back direction are orthogonal to each other. In addition, the definition of direction in this specification is an example. Therefore, the direction when the deformation detection sensor 1 is actually used does not need to be consistent with the direction in this specification. Figures 1 to 13 , Fig.18 , Figure 21 to Figure 25 , Figure 27 to Figure 34 The up and down directions can also be reversed. Figures 1 to 13 , Fig.18 , Figure 21 to Figure 25 , Figure 27 to Figure 34 The left and right directions can also be reversed. Figures 1 to 13, Fig.18 , Figure 21 to Figure 25 , Figure 27 to Figure 34 The front-to-back direction can also be reversed. Figure 1 to Figure 3 , Figures 5 to 10 , Fig.12 , Figure 21 to Figure 25 , Figure 27 to Figure 34 In the case of piezoelectric film, the up and down direction can also be reversed. Figure 1 to Figure 3 , Figures 5 to 10 , Fig.12 , Figure 21 to Figure 25 , Figure 27 to Figure 34 In the case of piezoelectric film, the left and right directions can also be reversed. Figure 1 to Figure 3 , Figures 5 to 10 , Fig.12 , Figure 21 to Figure 25 , Figure 27 to Figure 34 In the process, the front-to-back direction of the piezoelectric film can also be reversed.

[0025] Hereinafter, X and Y are components or members of the deformation detection sensor 1. In this specification, unless otherwise specified, the parts of X are defined as follows. The upper part of X refers to the upper half of X. The upper end of X refers to the end in the upper direction of X. The upper end portion of X refers to the upper end of X and its vicinity. This definition can also be applied to directions other than the upper direction.

[0026] In addition, "X is located above Y." means that X is located directly above Y. Therefore, when viewed in the vertical direction, X overlaps with Y. "X is located above Y." means that X is located directly above Y and X is located obliquely above Y. Therefore, when viewed in the vertical direction, X may overlap with Y or may not overlap with Y. This definition can also be applied to directions other than the upward direction.

[0027] In this specification, "X is electrically connected to Y" means that there is electrical conduction between X and Y. Therefore, X and Y may be in contact or not. When X and Y are not in contact, Z having conductivity is arranged between X and Y.

[0028] In this specification, the bending angle θ of the flexible base 2 is defined as follows: The bending angle θ of the flexible base 2 is defined as an angle formed by the first portion P1 of the flexible base 2 and the second portion P2 of the flexible base 2 when viewed in the direction in which the first bending line L1 extends.

[0029] Effects of the Invention

[0030] According to the deformation detection sensor of the present invention, the bending angle of the substrate can be detected with high accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is an exploded perspective view of the deformation detection sensor 1 according to the first embodiment.

[0032] Figure 2 It is a perspective view of the deformation detection sensor 1 according to the first embodiment.

[0033] Figure 3 This is a cross-sectional view of the deformation detection sensor 1 when the bending angle θ of the flexible base material 2 according to the first embodiment is 0 degrees as viewed in the front direction.

[0034] Figure 4 This is a cross-sectional view of the deformation detection sensor 1 when the bending angle θ of the flexible base material 2 according to the first embodiment is 180 degrees as viewed in the front direction.

[0035] Figure 5 It is a cross-sectional view of the first sensor 3 according to the first embodiment as viewed in the front direction.

[0036] Figure 6 It is a plan view of the first sensor 3 according to the first embodiment as viewed in a downward direction.

[0037] Figure 7 It is a plan view of the deformation detection sensor 1 according to the first embodiment as viewed in a downward direction.

[0038] Figure 8 It is a plan view of the deformation detection sensor 1 according to the first embodiment as viewed in a downward direction.

[0039] Fig. 9 It is an exploded perspective view of the electronic device 100 according to the first embodiment.

[0040] Fig.10 This is a cross-sectional view of the electronic device 100 when the bending angle θ of the flexible base material 2 according to the first embodiment is 0 degrees as viewed in the front direction.

[0041] Fig.11 This is a cross-sectional view of the electronic device 100 when the bending angle θ of the flexible base material 2 according to the first embodiment is 180 degrees as viewed from the front direction.

[0042] Fig.12 This is a cross-sectional view of the deformation detection sensor 10 of the comparative example when the bending angle θ of the flexible base material 2 of the comparative example is 0 degrees as viewed in the forward direction.

[0043] Fig.13 This is a cross-sectional view of the deformation detection sensor 10 of the comparative example when the bending angle θ of the flexible base material 2 of the comparative example is 180 degrees as viewed in the forward direction.

[0044] Fig.14 This is an example of the first detection signal SigD1 when the bending angle θ of the flexible base material 2 of the comparative example is changed from 0 degrees to 180 degrees.

[0045] Fig.15 This is an example of the first integrated value IV1 when the bending angle θ of the flexible base material 2 of the comparative example is changed from 0 degrees to 180 degrees.

[0046] Fig.16 This is an example of the first integrated value IV1 when the noise N is superimposed on the first detection signal SigD1 when the bending angle θ of the flexible base material 2 of the comparative example is changed from 0 degrees to 180 degrees.

[0047] Fig.17 This is an example of the first detection signal SigD1 when the bending angle θ of the flexible base material 2 according to the first embodiment is changed from 0 degrees to 180 degrees.

[0048] Fig.18 This is a cross-sectional view of the deformation detection sensor 1 and the flexible base material 2 when the bending angle θ of the flexible base material 2 according to the first embodiment is θa as viewed from the front direction.

[0049] Fig.19 This is an example of the first integrated value IV1 when the bending angle θ of the flexible base material 2 according to the first embodiment is changed from 0 degrees to 180 degrees.

[0050] Fig. 20 This is an example of the first integrated value IV1 when the noise N is superimposed on the first detection signal SigD1 when the bending angle θ of the flexible base material 2 according to the first embodiment is changed from 0 degrees to 180 degrees.

[0051] Fig.21 It is an exploded perspective view of a deformation detection sensor 1 a according to a first modification.

[0052] Fig. 22 It is a plan view of the deformation detection sensor 1b according to the second modification example as viewed in a downward direction.

[0053] Fig.23 It is a top view of the deformation detection sensor 1c according to the third modification example as viewed in the downward direction.

[0054] Fig.24 It is an exploded perspective view of a deformation detection sensor 1d according to the second embodiment.

[0055] Fig.25 It is an exploded perspective view of an electronic device 100d according to the second embodiment.

[0056] Fig.26 This is an example of the second integrated value IV2 when the noise N is superimposed on the second detection signal SigD2 when the bending angle θ of the flexible base material 2 according to the second embodiment is changed from 0 degrees to 180 degrees.

[0057] Fig. 27It is an exploded perspective view of a deformation detection sensor 1e according to a fourth modified example.

[0058] Fig.28 It is an exploded perspective view of the deformation detection sensor 1f according to the third embodiment.

[0059] Fig.29 It is a plan view of the deformation detection sensor 1f according to the third embodiment as viewed in a downward direction.

[0060] Fig.30 It is an exploded perspective view of a deformation detection sensor 1g according to a fifth modification.

[0061] Fig.31 It is a top view of the deformation detection sensor 1h according to the sixth modification example as viewed in a downward direction.

[0062] Fig.32 This is a plan view of the deformation detection sensor 1i according to the seventh modification example as viewed in a downward direction.

[0063] Fig.33 It is an exploded perspective view of a deformation detection sensor 1j according to a fourth embodiment.

[0064] Fig.34 It is an exploded perspective view of a deformation detection sensor 1k according to an eighth modification. DETAILED DESCRIPTION

[0065] [First embodiment]

[0066] (Structure of the deformation detection sensor 1)

[0067] Hereinafter, the structure of the deformation detection sensor 1 according to the first embodiment of the present invention will be described with reference to the drawings. Figure 1 It is an exploded perspective view of the deformation detection sensor 1 according to the first embodiment. Figure 2 It is a perspective view of the deformation detection sensor 1 according to the first embodiment. Figure 3 This is a cross-sectional view of the deformation detection sensor 1 when the bending angle θ of the flexible base material 2 according to the first embodiment is 0 degrees as viewed in the front direction. Figure 4 This is a cross-sectional view of the deformation detection sensor 1 when the bending angle θ of the flexible base material 2 according to the first embodiment is 180 degrees as viewed in the front direction. Figure 5 It is a cross-sectional view of the first sensor 3 according to the first embodiment as viewed in the front direction. Figure 6 It is a plan view of the first sensor 3 according to the first embodiment as viewed in a downward direction. Figure 7 It is a plan view of the deformation detection sensor 1 according to the first embodiment as viewed in a downward direction. Figure 8 It is a plan view of the deformation detection sensor 1 according to the first embodiment as viewed in a downward direction.

[0068] The deformation detection sensor 1 is used in, for example, a foldable smartphone. Figure 1 As shown, the deformation detection sensor 1 includes a flexible base 2, a first sensor 3, a first deformation preventing member 4, a second deformation preventing member 5, and a calculation circuit (not shown).

[0069] like Figure 2 As shown, when viewed in the up-down direction, the flexible substrate 2 has a sheet shape, and the sheet shape has a rectangular shape. Therefore, the flexible substrate 2 has a substrate upper main surface US2 and a substrate lower main surface LS2 arranged in the up-down direction. The substrate upper main surface US2 is located above the substrate lower main surface LS2. In addition, when viewed in the up-down direction, the flexible substrate 2 has a long side extending in the left-right direction and a short side extending in the front-back direction.

[0070] The flexible substrate 2 has flexibility. Figure 3 and Figure 4 As shown in FIG. 1 , the flexible base material 2 is bent at a first bending line L1 extending in the front-rear direction. Figure 3 As shown, the flexible substrate 2 has non-bending sections NCS1, NCS3 and a bending section CS2. The non-bending sections NCS1 and NCS3 are sections that are not bent when the flexible substrate 2 is bent at the first bending line L1. The bending section CS2 is a section that is bent when the flexible substrate 2 is bent at the first bending line L1. When the flexible substrate 2 is not bent, the non-bending section NCS1, the bending section CS2 and the non-bending section NCS3 are arranged in order from left to right.

[0071] like Figure 3 As shown, the flexible substrate 2 includes a first portion P1 and a second portion P2. The first portion P1 is located in the non-bending section NCS1. The second portion P2 is located in the non-bending section NCS3. By bending the flexible substrate 2, the second portion P2 can be bent as shown in FIG. Figure 4 The flexible substrate 2 is shown rotated relative to the first portion P1. The flexible substrate 2 is, for example, a display. The flexible substrate 2 is realized by, for example, an organic EL display.

[0072] The first sensor 3 outputs a first detection signal SigD1 corresponding to the deformation of the bending section CS2 of the flexible base 2. Figure 1 As shown in FIG. 1 , the first sensor 3 is provided on the main surface US2 of the flexible substrate 2. In more detail, in addition, as Figure 5 As shown in FIG. 1 , the first sensor 3 has a first upper main surface US3 and a first lower main surface LS3 arranged in the vertical direction. The first upper main surface US3 is located above the first lower main surface LS3. Figure 1 As shown, the first sensor 3 is provided on the substrate upper main surface US2 of the flexible substrate 2 such that the first lower main surface LS3 is in contact with the substrate upper main surface US2 of the flexible substrate 2 .

[0073] like Figure 6 As shown in FIG. 1 , when viewed in the up-down direction, the first sensor 3 has a rectangular shape having long sides extending in the left-right direction and short sides extending in the front-back direction. Figure 1 As shown, the first sensor 3 includes a first piezoelectric film 31 , a first upper electrode 32 , and a first lower electrode 33 .

[0074] The first piezoelectric film 31 has a sheet shape. Figure 5 As shown, the first piezoelectric film 31 includes a first piezoelectric film upper principal surface US31 and a first piezoelectric film lower principal surface LS31 arranged in the up-down direction. The first piezoelectric film upper principal surface US31 is located above the first piezoelectric film lower principal surface LS31.

[0075] like Figure 6 As shown, when viewed in the up-down direction, the first piezoelectric film 31 has a rectangular shape having long sides extending in the left-right direction and short sides extending in the front-back direction.

[0076] The first piezoelectric film 31 generates electric charge according to the amount of deformation of the first piezoelectric film 31. In the present embodiment, the first piezoelectric film 31 is a PLA film. The first piezoelectric film 31 will be described in more detail below.

[0077] The first piezoelectric film 31 has a characteristic that the polarity of the charge generated when the first piezoelectric film 31 is stretched in the left-right direction of the piezoelectric film is opposite to the polarity of the charge generated when the first piezoelectric film 31 is stretched in the front-back direction of the piezoelectric film. Specifically, the first piezoelectric film 31 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 when the molecules are oriented by uniaxial stretching. The first piezoelectric film 31 has a piezoelectric constant of d14.

[0078] Here, for the angle formed by the uniaxial stretching direction OD of the first piezoelectric film 31, the clockwise direction relative to the predetermined direction when the piezoelectric film is observed in the vertical direction (vertical direction) is defined as a negative angle, and the counterclockwise direction relative to the predetermined direction when the piezoelectric film is observed in the vertical direction (vertical direction) is defined as a positive angle. Figure 6 As shown in FIG. 1 , when the piezoelectric film is observed in the up-down direction (up-down direction), the uniaxial stretching direction OD of the first piezoelectric film 31 forms an angle of 45 degrees with respect to the left-right direction (left-right direction) of the piezoelectric film, and when the piezoelectric film is observed in the up-down direction (up-down direction), the uniaxial stretching direction OD of the first piezoelectric film 31 forms an angle of -45 degrees with respect to the front-back direction (front-back direction of the piezoelectric film). Therefore, as Figure 6 As shown, when the flexible substrate 2 is not bent, the uniaxial stretching direction OD of the first piezoelectric film 31 forms an angle of -45 degrees with respect to the first bending line L1 when viewed in the up-down direction. In addition, the -45 degrees includes, for example, an angle of about -45 degrees ±10 degrees. In addition, the -45 degrees includes an angle of about 135 degrees ±10 degrees (about -225 degrees ±10 degrees). Thus, the first piezoelectric film 31 generates electric charge by stretching the first piezoelectric film 31 in the left-right direction of the piezoelectric film or in the front-back direction of the piezoelectric film.

[0079] The polarity of the charge generated by the first piezoelectric film 31 when the first piezoelectric film 31 is stretched in the left-right direction of the piezoelectric film is different from the polarity of the charge generated by the first piezoelectric film 31 when the first piezoelectric film 31 is stretched in the front-back direction of the piezoelectric film. The first piezoelectric film 31 generates negative charge when the piezoelectric film is stretched, for example, in the left-right direction. The first piezoelectric film 31 generates positive charge when the piezoelectric film is stretched, for example, in the front-back direction. The magnitude of the charge depends on the amount of deformation of the first piezoelectric film 31 caused by stretching or compression. More precisely, the magnitude of the charge is proportional to the differential value of the deformation of the first piezoelectric film 31 caused by stretching or compression.

[0080] The first upper electrode 32 is a ground electrode. The first upper electrode 32 has an upper main surface and a lower main surface arranged in the vertical direction. The first upper electrode 32 is electrically connected to the ground potential. Figure 5 As shown, the first upper electrode 32 is provided on the first piezoelectric film upper main surface US31 of the first piezoelectric film 31. Figure 6 As shown, the first upper electrode 32 covers the entire first piezoelectric film upper main surface US31 of the first piezoelectric film 31. The first upper electrode 32 includes an adhesive layer not shown. Moreover, the first upper electrode 32 is fixed to the first piezoelectric film upper main surface US31 of the first piezoelectric film 31 through the adhesive layer. The upper main surface of the first upper electrode 32 is the first upper main surface US3 of the first sensor 3.

[0081] The first lower electrode 33 is a first signal electrode. The first lower electrode 33 has an upper main surface and a lower main surface arranged in the vertical direction. The first detection signal SigD1 corresponding to the deformation of the bending section CS2 of the flexible substrate 2 is output from the first lower electrode 33. Figure 5 As shown in FIG. 1 , the first lower electrode 33 is provided on the first piezoelectric film lower main surface LS31 of the first piezoelectric film 31. Figure 6 As shown, the first lower electrode 33 covers the entire first piezoelectric film lower main surface LS31 of the first piezoelectric film 31. The first lower electrode 33 includes an adhesive layer not shown. Moreover, the first lower electrode 33 is fixed to the first piezoelectric film lower main surface LS31 of the first piezoelectric film 31 through the adhesive layer. The lower main surface of the first lower electrode 33 is the first lower main surface LS3 of the first sensor 3.

[0082] like Figure 3 As shown, such a first sensor 3 is provided on the substrate upper main surface US2 of the flexible substrate 2 so as to straddle the first bending line L1 when viewed in the vertical direction. That is, the first sensor 3 has a portion located to the left of the first bending line L1 and a portion located to the right of the first bending line L1.

[0083] like Figure 1 As shown in FIG. 1 , the first deformation preventing member 4 and the second deformation preventing member 5 are arranged in sequence from left to right with a gap therebetween. Figure 3 As shown in FIG. 1 , the first deformation preventing member 4 is located on the left side of the first bending line L1. The second deformation preventing member 5 is located on the right side of the first bending line L1. Figure 1 As shown, the first deformation preventing member 4 and the second deformation preventing member 5 do not overlap each other when viewed in the up-down direction.

[0084] like Figure 1 As shown, when viewed in the up-down direction, the first deformation preventing member 4 has a rectangular shape having a short side extending in the left-right direction and a long side extending in the front-back direction. The material of the first deformation preventing member 4 is, for example, metal, resin, ceramic, or glass. The first deformation preventing member 4 is harder than the first piezoelectric film 31 of the first sensor 3. For example, the Young's modulus of the first deformation preventing member 4 is greater than the Young's modulus of the first piezoelectric film 31 of the first sensor 3.

[0085] like Figure 1 As shown in FIG. 1 , the first deformation inhibiting member 4 is provided on the first upper main surface US3 of the first sensor 3. Figure 7 As shown in FIG. 1 , the first deformation preventing member 4 has a first region A1 overlapping the first piezoelectric film 31 when viewed in the up-down direction. The first region A1 is located on the left side of the first bending line L1.

[0086] In addition, in this embodiment, if Figure 2 As shown in FIG. 1 , the first deformation preventing member 4 covers the entire left side surface, the left end of the front side surface, and the left end of the rear side surface of the first sensor 3. Thus, when viewed in the up-down direction, the first deformation preventing member 4 contacts the substrate upper main surface US2 of the flexible substrate 2 in front of the first sensor 3, in front of the left of the first sensor 3, to the left of the first sensor 3, to the left of the first sensor 3, to the left of the first sensor 3, and to the rear of the first sensor 3. That is, as shown in FIG. Figure 7 As shown, the first deformation preventing member 4 has a third region A3 which contacts the substrate upper main surface US2 of the flexible substrate 2 and does not overlap with the first piezoelectric film 31 of the first sensor 3 when viewed in the up-down direction. The first deformation preventing member 4 is fixed to the substrate upper main surface US2 in the third region A3.

[0087] like Figure 1 As shown, when viewed in the up-down direction, the second deformation preventing member 5 has a rectangular shape having a short side extending in the left-right direction and a long side extending in the front-back direction. The material of the second deformation preventing member 5 is, for example, metal, resin, ceramic, or glass. The second deformation preventing member 5 is harder than the first piezoelectric film 31 of the first sensor 3. For example, the Young's modulus of the second deformation preventing member 5 is larger than the Young's modulus of the first piezoelectric film 31 of the first sensor 3.

[0088] like Figure 1 As shown in FIG. 1 , the second deformation inhibiting member 5 is provided on the first upper main surface US3 of the first sensor 3. Figure 7 As shown in FIG. 1 , when viewed in the up-down direction, the second deformation preventing member 5 has a second region A2 overlapping the first piezoelectric film 31. In the present embodiment, the second region A2 is located on the right side of the first bending line L1.

[0089] In addition, in this embodiment, if Figure 2 As shown in FIG. 1 , the second deformation preventing member 5 covers the entire right side surface, the right end of the front side surface, and the right end of the rear side surface of the first sensor 3. Thus, when viewed in the up-down direction, the second deformation preventing member 5 contacts the substrate upper main surface US2 of the flexible substrate 2 in front of the first sensor 3, in front of the right side of the first sensor 3, to the right of the first sensor 3, to the right of the first sensor 3, to the right of the first sensor 3, and to the rear of the first sensor 3. That is, as shown in FIG. Figure 7 As shown, the second deformation preventing member 5 has a fourth region A4 which contacts the substrate upper main surface US2 of the flexible substrate 2 and does not overlap the first piezoelectric film 31 of the first sensor 3 when viewed in the up-down direction. The second deformation preventing member 5 is fixed to the substrate upper main surface US2 in the fourth region A4.

[0090] like Figure 7 As shown, the first region A1 and the second region A2 are arranged at intervals in the left-right direction. More specifically, the first region A1 is located to the left of the second region A2. In addition, when the flexible substrate 2 is not bent, the first region A1 and the second region A2 do not contact each other when viewed in the up-down direction. Therefore, when viewed in the up-down direction, the first region A1 and the second region A2 do not overlap each other. In addition, the first piezoelectric film 31 has a tenth region A10, and when viewed in the up-down direction, the tenth region A10 does not overlap with the first deformation blocking member 4 and the second deformation blocking member 5.

[0091] Here, a distance D1 in the left-right direction between the first area A1 and the second area A2 when the flexible base 2 is not bent is defined. Figure 7As shown, the distance D1 between the first area A1 and the second area A2 in the left-right direction is the shortest distance in the left-right direction between the portions where the first area A1 and the second area A2 do not contact each other. In the present embodiment, the right end of the first area A1 coincides with a portion of the right side of the first deformation preventing member 4. The right edge of the first deformation preventing member 4 extends in the front-to-back direction. In addition, the left end of the second area A2 coincides with a portion of the left side of the second deformation preventing member 5. The left edge of the second deformation preventing member 5 extends in the front-to-back direction. Therefore, the distance D1 between the first area A1 and the second area A2 in the left-to-right direction is the distance between the right side of the first deformation preventing member 4 and the left side of the second deformation preventing member 5 as viewed in the up-down direction.

[0092] like Figure 7 As shown, in a state where the flexible base 2 is not bent, a distance D1 between the first area A1 and the second area A2 in the left-right direction is shorter than a length DLR31 of the first piezoelectric film 31 in the left-right direction.

[0093] Here, if Figure 8 As shown, the left-right position where the first area A1 exists when the flexible base 2 is not bent is defined as a first position PO1. Also, the left-right position where the second area A2 exists when the flexible base 2 is not bent is defined as a second position PO2.

[0094] like Figure 8 As shown, when the flexible substrate 2 is not bent, the length DFB4 of the first deformation hindering member 4 in the front-to-back direction at the first position PO1 is longer than the length DFB311 of the first piezoelectric film 31 in the front-to-back direction at the first position PO1. In addition, it is sufficient that there is a first position PO1 such that when the flexible substrate 2 is not bent, the length DFB4 of the first deformation hindering member 4 in the front-to-back direction at the first position PO1 is longer than the length DFB311 of the first piezoelectric film 31 in the front-to-back direction at the first position PO1.

[0095] like Figure 8 As shown, when the flexible substrate 2 is not bent, the length DFB5 of the second deformation hindering member 5 in the front-to-back direction at the second position PO2 is longer than the length DFB312 of the first piezoelectric film 31 in the front-to-back direction at the second position PO2. In addition, it is sufficient that there is a first position PO1 such that when the flexible substrate 2 is not bent, the maximum value of the length DFB5 of the second deformation hindering member 5 in the front-to-back direction at the second position PO2 is longer than the length DFB312 of the first piezoelectric film 31 in the front-to-back direction at the second position PO2.

[0096] The calculation circuit receives the first detection signal SigD1 output by the first sensor 3. The calculation circuit integrates the first detection signal SigD1 over time to calculate a first integral value IV1. The calculation circuit calculates the bending angle θ of the flexible substrate 2 by associating the first integral value IV1 with the bending angle θ of the flexible substrate 2.

[0097] The method of associating the first integrated value IV1 and the bending angle θ of the flexible base material 2 is, for example, to set the bending angle θ of the flexible base material 2 to 0 when the first integrated value IV1 is 0, and to set the bending angle θ of the flexible base material 2 to 180 degrees when the first integrated value IV1 is -180 degrees. In addition, for example, the absolute value of the first integrated value IV1 in the case of -180<first integrated value IV1<0 is set as the bending angle θ (degrees) of the flexible base material 2. In addition, the method of associating the first integrated value IV1 and the bending angle θ of the flexible base material 2 is only an example, and other methods may be used.

[0098] When the value of the first detection signal SigD1 is discontinuous, the operation circuit sets the bending angle θ of the flexible base material 2 to θa. θa is the bending angle θ of the flexible base material 2 at which the first deformation preventing member 4 and the second deformation preventing member 5 begin to contact each other when the bending angle θ of the flexible base material 2 is changed from 0 degrees to 180 degrees. At this time, the operation circuit corrects the first integrated value IV1 to a value associated with θa.

[0099] (Structure of Electronic Device 100)

[0100] Hereinafter, the structure of the electronic device 100 according to the first embodiment of the present invention will be described with reference to the drawings. Fig. 9 It is an exploded perspective view of the electronic device 100 according to the first embodiment. Fig.10 This is a cross-sectional view of the electronic device 100 when the bending angle θ of the flexible base material 2 according to the first embodiment is 0 degrees as viewed in the front direction. Fig.11 This is a cross-sectional view of the electronic device 100 when the bending angle θ of the flexible base material 2 according to the first embodiment is 180 degrees as viewed from the front direction.

[0101] like Fig. 9 As shown, the electronic device 100 includes a deformation detection sensor 1, a flexible substrate 2, a first housing 6, and a second housing 7. The electronic device 100 is, for example, a foldable smartphone.

[0102] like Figure 1 As shown in FIG. 1 , the first housing 6 is provided on the lower main surface LS2 of the flexible substrate 2. Fig. 9 As shown, the first housing 6 is a box. The first housing 6 has a rectangular parallelepiped shape.

[0103] like Figure 1As shown in FIG. 1 , the second housing 7 is provided on the lower main surface LS2 of the flexible substrate 2. Fig. 9 As shown, the second housing 7 is a box. The second housing 7 has a rectangular parallelepiped shape.

[0104] like Fig.10 As shown in FIG. 1 , when viewed in the vertical direction, the first housing 6 is located in the non-bending section NCS1 of the flexible substrate 2. When viewed in the vertical direction, the second housing 7 is located in the non-bending section NCS3 of the flexible substrate 2. The flexible substrate 2 is bent, so that the second housing 7 can be bent as shown in FIG. Fig.11 As shown, it rotates relative to the first housing 6.

[0105] like Fig.10 As shown in FIG. 1 , the first housing 6 is located to the left of the first bending line L1. The second housing 7 is located to the right of the first bending line L1. Fig. 9 As shown, when the flexible base 2 is not bent, the first bending line L1 is located between the first shell 6 and the second shell 7 when viewed in the vertical direction. In addition, when the flexible base 2 is not bent, the first shell 6 and the second shell 7 do not overlap each other when viewed in the vertical direction.

[0106] Furthermore, the deformation detection sensor 1 has a structure capable of accurately detecting the bending angle θ of the flexible base material 2. This structure will be described below. Fig.12 This is a cross-sectional view of the deformation detection sensor 10 of the comparative example when the bending angle θ of the flexible base material 2 of the comparative example is 0 degrees as viewed in the forward direction. Fig.13 This is a cross-sectional view of the deformation detection sensor 10 of the comparative example when the bending angle θ of the flexible base material 2 of the comparative example is 180 degrees as viewed in the forward direction. Fig.14 This is an example of the first detection signal SigD1 when the bending angle θ of the flexible substrate 2 of the comparative example is changed from 0 degrees to 180 degrees. Fig.14 In FIG. 1 , the horizontal axis represents the bending angle θ of the flexible base material 2 , and the vertical axis represents the value of the first detection signal SigD1 . Fig.15 This is an example of the first integrated value IV1 when the bending angle θ of the flexible base material 2 of the comparative example is changed from 0 degrees to 180 degrees. Fig.15 In FIG. 1 , the horizontal axis represents time t, and the vertical axis represents the first integrated value IV1. Fig.16 This is an example of the first integrated value IV1 when the noise N is superimposed on the first detection signal SigD1 when the bending angle θ of the flexible base material 2 of the comparative example is changed from 0 degrees to 180 degrees. Fig.16 In FIG. 1 , the horizontal axis represents the bending angle θ or the time t of the flexible base material 2 , and the vertical axis represents the value of the first detection signal SigD1 , the value of the noise N, and the first integrated value IV1 . Fig.17This is an example of the first detection signal SigD1 when the bending angle θ of the flexible base material 2 of the first embodiment is changed from 0 degrees to 180 degrees. Fig.17 In FIG. 1 , the horizontal axis represents the bending angle θ of the flexible base material 2 , and the vertical axis represents the value of the first detection signal SigD1 . Fig.18 This is a cross-sectional view of the deformation detection sensor 1 and the flexible base material 2 when the bending angle θ of the flexible base material 2 according to the first embodiment is θa as viewed from the front direction. Fig.19 This is an example of the first integrated value IV1 when the bending angle θ of the flexible base material 2 of the first embodiment is changed from 0 degrees to 180 degrees. Fig.19 In FIG. 1 , the horizontal axis represents time t, and the vertical axis represents the first integrated value IV1. Fig. 20 This is an example of the first integrated value IV1 when the noise N is superimposed on the first detection signal SigD1 when the bending angle θ of the flexible base material 2 of the first embodiment is changed from 0 degrees to 180 degrees. Fig. 20 In FIG. 1 , the horizontal axis represents the bending angle θ or the time t of the flexible base material 2 , and the vertical axis represents the value of the first detection signal SigD1 , the value of the noise N, and the first integrated value IV1 .

[0107] like Fig.12 As shown, the deformation detection sensor 10 of the comparative example is different from the deformation detection sensor 1 in that it does not include the first deformation preventing member 4 and the second deformation preventing member 5. Since the deformation detection sensor 10 of the comparative example is the same as the deformation detection sensor 1 in other points, the description thereof is omitted.

[0108] In the deformation detection sensor 10 of the comparative example, as Fig.14 As shown, the bending angle θ of the flexible substrate 2 is changed from 0 degrees ( Fig.12 ) changes to 180 degrees ( Fig.13 ), the value of the first detection signal SigD1 output by the first sensor 3 becomes a negative constant value. The reason why the first detection signal SigD1 is negative is that when the bending angle θ of the flexible substrate 2 is increased, the first piezoelectric film 31 generates negative charges due to the stretching in the left-right direction of the piezoelectric film. The reason why the value of the first detection signal SigD1 is a constant value is that the magnitude of the charge generated by the first piezoelectric film 31 is proportional to the differential value of the deformation amount of the first piezoelectric film 31 caused by the stretching, and the bending angle θ of the flexible substrate 2 is changed at a constant angular velocity.

[0109] In the deformation detection sensor 10 of the comparative example, as Fig.15 As shown, the calculation circuit integrates the first detection signal SigD1 over time to calculate a first integrated value IV1 . The calculation circuit also calculates the bending angle θ of the flexible base material 2 by associating the first integrated value IV1 with the bending angle θ of the flexible base material 2 .

[0110] Next, the problem of the deformation detection sensor 10 of the comparative example is described. In the deformation detection sensor 10 of the comparative example, it is difficult to detect the bending angle θ of the flexible base material 2 with good accuracy. The deformation detection sensor 10 of the comparative example detects the bending angle θ of the flexible base material 2 by associating the first integral value IV1 calculated by the operation circuit with the bending angle θ of the flexible base material 2. Therefore, due to the intrusion of noise N into the deformation detection sensor 10 of the comparative example during the deformation of the flexible base material 2 and the repetition of the deformation of the flexible base material 2, an error occurs between the actual bending angle θ of the flexible base material 2 and the value of the detected bending angle θ of the flexible base material 2.

[0111] For example, Fig.16 As shown in FIG. 1 , when the noise N is superimposed on the first detection signal SigD1 , an error occurs between the actual bending angle θ of the flexible base material 2 and the value of the detected bending angle θ of the flexible base material 2 . Fig.16 In the example shown, when the angle is less than 180 degrees (set to θ1), the first integrated value IV1 becomes -180, so that the calculation circuit calculates the bending angle θ of the flexible base material 2 as 180 degrees regardless of whether the actual bending angle θ of the flexible base material 2 is θ1. Therefore, in the deformation detection sensor 10 of the comparative example, it is difficult to detect the bending angle θ of the flexible base material 2 with good accuracy.

[0112] On the other hand, in the deformation detection sensor 1, as Fig.17 As shown, the bending angle θ of the flexible substrate 2 is changed from 0 degrees ( Figure 3 ) changes to 180 degrees ( Figure 4 ), the value of the first detection signal SigD1 output by the first sensor 3 has a discontinuous portion. The reason for this will be described below.

[0113] In the deformation detection sensor 1, when the bending angle θ of the flexible base 2 is changed from 0 degrees to 180 degrees at a constant angular velocity, the first deformation preventing member 4 and the second deformation preventing member 5 do not contact each other within the range of 0 degrees ≤ θ < θa. Fig.17 As shown, the value of the first detection signal SigD1 outputted from the first sensor 3 becomes a negative constant value within the range of 0 degrees ≤ θ < θa.

[0114] like Fig.18 As shown in FIG. 1 , when the bending angle θ of the flexible substrate 2 becomes θa (0 degrees < θa < 180 degrees), the first deformation hindering member 4 and the second deformation hindering member 5 are in contact with each other. In the range of θa ≤ θ ≤ 180 degrees, the first deformation hindering member 4 and the second deformation hindering member 5 are in contact with each other. At this time, the first deformation hindering member 4 and the second deformation hindering member 5 suppress the first piezoelectric film 31 from stretching in the left-right direction of the piezoelectric film. As a result, as shown in FIG. Fig.17 As shown in FIG. 1 , the absolute value of the value of the first detection signal SigD1 in the range of θa≤θ≤180 degrees is smaller than the absolute value of the value of the first detection signal SigD1 in the range of 0 degrees≤θ<θa. In addition, the first piezoelectric film 31 is not stretched in the left-right direction of the piezoelectric film even in the range of θa≤θ≤180 degrees. Therefore, when the bending angle θ of the flexible substrate 2 is changed from θa( Fig.18 ) changes to 180 degrees ( Figure 4 ), the first piezoelectric film 31 generates negative charges. Fig.17 As shown, the value of the first detection signal SigD1 outputted from the first sensor 3 becomes a negative constant value within the range of θa≤θ≤180 degrees.

[0115] like Fig.19 As shown, the operation circuit integrates the first detection signal SigD1 over time to calculate the first integral value IV1. In addition, when the value of the first detection signal SigD1 is discontinuous ( Fig.19 At time t1 in FIG. 1 , the bending angle θ of the flexible base material 2 is set to θa. At this time, the calculation circuit corrects the first integrated value IV1 to -θa.

[0116] For example, Fig. 20 As shown in FIG. 1 , when the noise N is superimposed on the first detection signal SigD1, an error occurs between the actual bending angle θ of the flexible substrate 2 and the value of the detected bending angle θ of the flexible substrate 2. However, when the value of the first detection signal SigD1 is discontinuous ( Fig. 20 At time t1 in the figure, the bending angle θ of the flexible substrate 2 is set to θa. At this time, the operation circuit corrects the first integral value IV1 to -θa. Therefore, the value of the first detection signal SigD1 in the range of θa≤θ≤180 degrees is not affected by the noise N superimposed in the range of 0 degrees≤θ<θa. As a result, according to the deformation detection sensor 1, the bending angle θ of the flexible substrate 2 can be detected with good accuracy.

[0117] [Effect]

[0118] According to the deformation detection sensor 1, the bending angle of the substrate can be detected with good accuracy. In more detail, the first deformation hindering member 4 is provided on the first upper main surface US3 of the first sensor 3. In addition, the second deformation hindering member 5 is provided on the first upper main surface US3 of the first sensor 3. That is, the first deformation hindering member 4 and the second deformation hindering member 5 are provided on the same surface of the first sensor 3. In addition, the first deformation hindering member 4 has a first area A1 overlapping with the first piezoelectric film 31 by being provided on the first upper main surface US3 of the first sensor 3. Similarly, the second deformation hindering member 5 has a second area A2 overlapping with the first piezoelectric film 31 by being provided on the first upper main surface US3 of the first sensor 3. In a state where the flexible substrate 2 is not bent, when viewed in the up-down direction, the first area A1 and the second area A2 do not contact each other. Thus, when viewed in the up-down direction, the first bending line L1 can be located between the first area A1 and the second area A2. The flexible substrate 2 is bent at the first bending line L1. At this time, the first deformation hindering member 4 and the second deformation hindering member 5 are in contact with each other. When the bending angle θ of the flexible base material 2 is θa, the value of the first detection signal SigD1 output by the first sensor 3 is discontinuous. θa is the bending angle θ of the flexible base material 2 at which the first deformation hindering member 4 and the second deformation hindering member 5 begin to contact each other when the bending angle θ of the flexible base material 2 is changed from 0 degrees to 180 degrees. Therefore, when the value of the first detection signal SigD1 is discontinuous, the operation circuit can set the bending angle θ of the flexible base material 2 to θa. At this time, the operation circuit can correct the first integrated value IV1 to a value associated with θa. Thus, according to the deformation detection sensor 1, the value of the first detection signal SigD1 in the range of θa≤θ≤180 degrees can be made not to be affected by the noise N superimposed in the range of 0 degrees≤θ<θa. Therefore, according to the deformation detection sensor 1, the bending angle θ of the flexible base material 2 can be detected with high accuracy. As a result, according to the deformation detection sensor 1, the bending angle of the base material can be detected with high accuracy.

[0119] According to the deformation detection sensor 1, it is possible to suppress the reliability of the deformation detection sensor 1 from being reduced due to the positional deviation of the first deformation obstruction member 4 or the second deformation obstruction member 5. More specifically, the first deformation obstruction member 4 has a third region A3 that contacts the substrate upper main surface US2 of the flexible substrate 2 and does not overlap with the first piezoelectric film 31 when viewed in the up-down direction. Thus, the first deformation obstruction member 4 can be fixed to the substrate upper main surface US2 of the flexible substrate 2 in the third region A3. Therefore, according to the deformation detection sensor 1, it is possible to suppress the positional deviation of the first deformation obstruction member 4. In addition, the second deformation obstruction member 5 has a fourth region A4 that contacts the substrate upper main surface US2 of the flexible substrate 2 and does not overlap with the first piezoelectric film 31 when viewed in the up-down direction. Thus, it is possible to fix the second deformation obstruction member 5 to the substrate upper main surface US2 of the flexible substrate 2 in the fourth region A4. Therefore, according to the deformation detection sensor 1, it is possible to suppress the positional deviation of the second deformation obstruction member 5. As a result, according to the deformation detection sensor 1 , it is possible to suppress a decrease in the reliability of the deformation detection sensor 1 caused by a positional deviation of the first deformation inhibiting member 4 or the second deformation inhibiting member 5 .

[0120] According to the deformation detection sensor 1, it is possible to suppress the first piezoelectric film 31 from peeling off from the flexible substrate 2 as the flexible substrate 2 is deformed. In more detail, the first sensor 3 is provided on the substrate upper main surface US2 of the flexible substrate 2. In addition, the first deformation obstruction member 4 is provided on the first upper main surface US3 of the first sensor 3. In addition, the second deformation obstruction member 5 is provided on the first upper main surface US3 of the first sensor 3. The deformation of the first sensor 3 is obstructed by the first deformation obstruction member 4 and the second deformation obstruction member 5. As a result, according to the deformation detection sensor 1, it is possible to suppress the first piezoelectric film 31 from peeling off from the flexible substrate 2 as the flexible substrate 2 is deformed.

[0121] According to the deformation detection sensor 1, it is possible to further suppress the first piezoelectric film 31 from peeling off from the flexible base material 2 as the flexible base material 2 is deformed. More specifically, in a state where the flexible base material 2 is not bent, the distance D1 between the first area A1 and the second area A2 in the left-right direction is shorter than the length of the first piezoelectric film 31 in the left-right direction. Thus, when viewed in the up-down direction, the area of ​​the portion of the first piezoelectric film 31 exposed from the first deformation preventing member 4 or the second deformation preventing member 5 can be reduced. As a result, according to the deformation detection sensor 1, it is possible to further suppress the first piezoelectric film 31 from peeling off from the flexible base material 2 as the flexible base material 2 is deformed.

[0122] According to the deformation detection sensor 1, it is possible to further suppress the first piezoelectric film 31 from peeling off from the flexible substrate 2 as the flexible substrate 2 is deformed. More specifically, there is a first position PO1 in which, when the flexible substrate 2 is not bent, the length of the first deformation hindering member 4 at the first position PO1 (the position in the left-right direction where the first area A1 exists) in the front-to-back direction is longer than the length of the first piezoelectric film 31 in the front-to-back direction at the first position PO1. Thus, when viewed in the up-down direction, the portion of the first deformation hindering member 4 located at the first position PO1 can be fixed to the substrate upper main surface US2 of the flexible substrate 2 in front of or behind the first piezoelectric film 31. Therefore, the first piezoelectric film 31 can be fixed to the substrate upper main surface US2 of the flexible substrate 2 more firmly. In addition, there is a second position PO2 in which the length of the second deformation hindering member 5 in the front-to-back direction at the second position PO2 (the position in the left-to-right direction where the second area A2 exists) is longer than the length of the first piezoelectric film 31 in the front-to-back direction at the second position PO2 when the flexible substrate 2 is not bent. Thus, when viewed in the up-down direction, the portion of the second deformation hindering member 5 located at the second position PO2 can be fixed to the substrate upper main surface US2 of the flexible substrate 2 in front of or behind the first piezoelectric film 31. Therefore, the first piezoelectric film 31 can be fixed to the substrate upper main surface US2 of the flexible substrate 2 more firmly. As a result, according to the deformation detection sensor 1, it is possible to suppress the first piezoelectric film 31 from peeling off from the flexible substrate 2 as the flexible substrate 2 is deformed.

[0123] According to the deformation detection sensor 1, the bending angle of the substrate can be detected with further better accuracy. In more detail, the first upper electrode 32 of the first sensor 3 is provided on the first piezoelectric film upper main surface US31 of the first piezoelectric film 31. The first upper electrode 32 is a ground electrode electrically connected to the ground potential. Therefore, the first upper electrode 32 becomes a noise countermeasure shielding member that invades from the outside of the deformation detection sensor 1. Therefore, according to the deformation detection sensor 1, noise is not easy to invade from the outside of the deformation detection sensor 1. As a result, according to the deformation detection sensor 1, the bending angle of the substrate can be detected with further better accuracy.

[0124] [First Modification]

[0125] Hereinafter, a deformation detection sensor 1 a according to a first modified example of the present invention will be described with reference to the drawings. Fig.21 1 is an exploded perspective view of the deformation detection sensor 1 a according to the first modification. In addition, only the parts of the deformation detection sensor 1 a according to the first modification that are different from the deformation detection sensor 1 according to the first embodiment will be described, and the description will be omitted below.

[0126] The deformation detection sensor 1 a is different from the deformation detection sensor 1 in that the first deformation preventing member 4 is provided on the first lower main surface LS3 of the first sensor 3 and the second deformation preventing member 5 is provided on the first lower main surface LS3 of the first sensor 3 .

[0127] like Fig.21 As shown, the first sensor 3 is provided on the substrate upper main surface US2 of the flexible substrate 2 such that the first lower main surface LS3 contacts the upper main surfaces of the first deformation preventing member 4 and the second deformation preventing member 5 .

[0128] In the deformation detection sensor 1a as described above, the same effect as that of the deformation detection sensor 1 is achieved. Thus, the second deformation preventing member 5 may be provided on the first upper main surface US3 or the first lower main surface LS3 of the first sensor 3, where the first deformation preventing member 4 is provided, of the first upper main surface US3 and the first lower main surface LS3.

[0129] [Second Modification]

[0130] Hereinafter, a deformation detection sensor 1b according to a second modified example of the present invention will be described with reference to the drawings. Fig. 22 It is a top view of the deformation detection sensor 1b of the second modification as viewed in the downward direction. In addition, the deformation detection sensor 1b of the second modification will only be described for the parts that are different from the deformation detection sensor 1 of the first embodiment, and the description will be omitted hereinafter.

[0131] The deformation detection sensor 1 a is different from the deformation detection sensor 1 in that it has a fifth area A5 where the first area A1 of the first deformation preventing member 4 and the second area A2 of the second deformation preventing member 5 overlap with each other.

[0132] like Fig. 22 As shown, the first area A1 and the second area A2 overlap each other in the fifth area A5. In addition, the first area A1 and the second area A2 are in contact with each other in the fifth area A5. The first area A1 and the second area A2 have a third portion P3 that does not contact each other when viewed in the up and down direction when the flexible base material 2 is not bent. In this modification, the third portion P3 is located in front of the fifth area A5. In addition, the first deformation preventing member 4 and the second deformation preventing member 5 have flexibility in the fifth area A5.

[0133] The deformation detection sensor 1b described above also has the same effect as the deformation detection sensor 1. In this way, the first area A1 and the second area A2 only need to have the third portion P3 that does not contact each other when viewed in the vertical direction when the flexible base 2 is not bent.

[0134] [Third Modification]

[0135] Hereinafter, a deformation detection sensor 1c according to a third modified example of the present invention will be described with reference to the drawings. Fig.23 It is a top view of the deformation detection sensor 1c of the third modification example as viewed in the downward direction. In addition, the deformation detection sensor 1c of the third modification example will only be described with respect to the parts that are different from the deformation detection sensor 1b of the second modification example, and the description will be omitted hereinafter.

[0136] The deformation detection sensor 1 c is different from the deformation detection sensor 1 b in that the first deformation preventing member 4 and the second deformation preventing member 5 are included in a single member 8 .

[0137] like Fig.23 As shown, the left portion of the member 8 and the right portion of the member 8 are connected in the fifth region A5. In addition, the member 8 has flexibility in the fifth region A5.

[0138] The deformation detection sensor 1c as described above also exhibits the same effects as those of the deformation detection sensor 1b.

[0139] [Second embodiment]

[0140] Hereinafter, a deformation detection sensor 1d according to a second embodiment of the present invention will be described with reference to the drawings. Fig.24 It is an exploded perspective view of a deformation detection sensor 1d according to the second embodiment. Fig.25 It is an exploded perspective view of an electronic device 100d according to the second embodiment. Fig.26 This is an example of the second integrated value IV2 when the noise N is superimposed on the second detection signal SigD2 when the bending angle θ of the flexible base material 2 of the second embodiment is changed from 0 degrees to 180 degrees. Fig.26 , the horizontal axis represents the bending angle θ or time t of the flexible substrate 2. The vertical axis represents the value of the second detection signal SigD2, the value of the noise N, and the second integrated value IV2. In addition, only the parts different from the deformation detection sensor 1 of the first embodiment will be described for the deformation detection sensor 1d of the second embodiment, which will be omitted.

[0141] The deformation detection sensor 1 d is different from the deformation detection sensor 1 b in that it further includes a second sensor 11 .

[0142] The second sensor 11 outputs a second detection signal SigD2 corresponding to the deformation of the bending section CS2 of the flexible base 2. Fig.24As shown, the second sensor 11 includes a second piezoelectric film 111, a second upper electrode 112, and a second lower electrode 113. The second sensor 11 is provided on the substrate upper main surface US2 of the flexible substrate 2. In more detail, in addition, the second sensor 11 has a second upper main surface US11 and a second lower main surface LS11 arranged in the up-down direction. The second upper main surface US11 is located above the second lower main surface LS11. The second sensor 11 is provided on the substrate upper main surface US2 of the flexible substrate 2 in such a manner that the second lower main surface LS11 contacts the substrate upper main surface US2 of the flexible substrate 2.

[0143] like Fig.24 As shown, when viewed in the up-down direction, the second sensor 11 has a rectangular shape having long sides extending in the left-right direction and short sides extending in the front-back direction.

[0144] like Fig.24 As shown, the second piezoelectric film 111 has a sheet shape. Therefore, the second piezoelectric film 111 has a second piezoelectric film upper principal surface US111 and a second piezoelectric film lower principal surface LS111 arranged in the vertical direction. The second piezoelectric film upper principal surface US111 is located above the second piezoelectric film lower principal surface LS111.

[0145] like Fig.24 As shown, when viewed in the vertical direction, the second piezoelectric film 111 has a rectangular shape having long sides extending in the left-right direction and short sides extending in the front-back direction. The second piezoelectric film 111 has the same structure as the first piezoelectric film 31, so the description thereof is omitted.

[0146] The second upper electrode 112 is a ground electrode. The second upper electrode 112 has an upper main surface and a lower main surface arranged in the vertical direction. The second upper electrode 112 is electrically connected to the ground potential. Fig.24 As shown, the second upper electrode 112 is provided on the second piezoelectric film upper principal surface US111 of the second piezoelectric film 111. In addition, since the second upper electrode 112 has the same structure as the first upper electrode 32, the description thereof is omitted.

[0147] The second lower electrode 113 is a second signal electrode. The second lower electrode 113 has an upper main surface and a lower main surface arranged in the vertical direction. The second lower electrode 113 outputs a second detection signal SigD2 corresponding to the deformation of the bending section CS2 of the flexible substrate 2. Fig.24 As shown, the second lower electrode 113 is provided on the second piezoelectric film lower principal surface LS111 of the second piezoelectric film 111. In addition, since the second lower electrode 113 has the same structure as the first lower electrode 33, the description thereof is omitted.

[0148] like Fig.24As shown, when the flexible base 2 is not bent, the second sensor 11 does not overlap with the first sensor 3, the first deformation preventing member 4, and the second deformation preventing member 5 when viewed in the up-down direction.

[0149] In addition, you can also Fig.25 As shown, the electronic device 100 a includes a deformation detection sensor 1 d , a first housing 6 , and a second housing 7 .

[0150] The first detection signal SigD1 output by the first sensor 3 and the second detection signal SigD2 output by the second sensor 11 are input to the operation circuit. The operation circuit integrates the second detection signal SigD2 over time to calculate the second integral value IV2. In addition, the operation circuit calculates the bending angle θ of the flexible substrate 2 by associating the second integral value IV2 with the bending angle θ of the flexible substrate 2. In addition, when the value of the first detection signal SigD1 is discontinuous, the operation circuit sets the bending angle θ of the flexible substrate 2 to θa. At this time, the operation circuit corrects the second integral value IV2 to a value associated with θa.

[0151] like Fig.26 As shown, when the bending angle θ of the flexible substrate 2 changes from 0 degrees to 180 degrees at a constant angular velocity, the value of the second detection signal SigD2 becomes a negative constant value. Since the reason why the second detection signal SigD2 is negative is the same as the reason why the first detection signal SigD1 of the comparative example is negative, the description is omitted.

[0152] For example, Fig.26 As shown in FIG. 1 , when the noise N is superimposed on the second detection signal SigD2, an error occurs between the actual bending angle θ of the flexible substrate 2 and the value of the detected bending angle θ of the flexible substrate 2. However, when the value of the first detection signal SigD1 is discontinuous ( Fig.26 At time t1 in the figure, the bending angle θ of the flexible substrate 2 is set to θa. At this time, the operation circuit corrects the second integral value IV2 to -θa. Therefore, the value of the second detection signal SigD2 in the range of θa≤θ≤180 degrees is not affected by the noise N superimposed in the range of 0 degrees≤θ<θa. In this way, according to the deformation detection sensor 1d, by using the first detection signal SigD1 output by the first sensor 3, the detection accuracy of the bending angle θ of the flexible substrate 2 of the second sensor 11 can also be improved.

[0153] [Fourth Modification]

[0154] Hereinafter, a deformation detection sensor 1e according to a fourth modified example of the present invention will be described with reference to the drawings. Fig. 271 is an exploded perspective view of a deformation detection sensor 1e according to a fourth modification. In addition, only the parts of the deformation detection sensor 1e according to the fourth modification that are different from the deformation detection sensor 1d according to the second embodiment will be described, and the description will be omitted below.

[0155] The deformation detection sensor 1 e is different from the deformation detection sensor 1 d in that the second sensor 11 is provided on the base material lower main surface LS2 of the flexible base material 2 .

[0156] like Fig. 27 As shown, the second sensor 11 is provided on the substrate lower main surface LS2 of the flexible substrate 2 such that the second upper main surface US11 contacts the substrate lower main surface LS2 of the flexible substrate 2 .

[0157] The second upper electrode 112 is a second signal electrode. A second detection signal SigD2 corresponding to the deformation of the bending section CS2 of the flexible base 2 is output from the second upper electrode 112. In addition, the second lower electrode 113 is a ground electrode. The second lower electrode 113 is electrically connected to the ground potential.

[0158] The deformation detection sensor 1e described above also exhibits the same effects as those of the deformation detection sensor 1d.

[0159] [Third embodiment]

[0160] Hereinafter, a deformation detection sensor 1f according to a third modified embodiment of the present invention will be described with reference to the drawings. Fig.28 It is an exploded perspective view of the deformation detection sensor 1f according to the third embodiment. Fig.29 It is a top view of the deformation detection sensor 1f of the third embodiment as viewed in the downward direction. In addition, only the parts of the deformation detection sensor 1f of the third embodiment that are different from the deformation detection sensor 1 of the first embodiment will be described, and the description will be omitted below.

[0161] The deformation detection sensor 1 f is different from the deformation detection sensor 1 in that it further includes a third deformation inhibiting member 12 .

[0162] like Fig.28 As shown in FIG. 1 , the third deformation inhibiting member 12 is provided on the first upper main surface US3 of the first sensor 3. Fig.29 As shown in FIG. 1 , the third deformation preventing member 12 has a sixth region A6 overlapping the first piezoelectric film 31 when viewed in the up-down direction.

[0163] like Fig.28 As shown in FIG. 1 , the first deformation preventing member 4, the third deformation preventing member 12 and the second deformation preventing member 5 are sequentially arranged from left to right with intervals therebetween. Fig.29As shown, the first deformation preventing member 4, the second deformation preventing member 5, and the third deformation preventing member 12 do not overlap each other when viewed in the up-down direction.

[0164] like Fig.29 As shown, when viewed in the up-down direction, the third deformation preventing member 12 has a rectangular shape having a short side extending in the left-right direction and a long side extending in the front-back direction. The material of the third deformation preventing member 12 is, for example, metal, resin, ceramic, or glass. The third deformation preventing member 12 is harder than the first piezoelectric film 31 of the first sensor 3. For example, the Young's modulus of the third deformation preventing member 12 is larger than the Young's modulus of the first piezoelectric film 31 of the first sensor 3.

[0165] like Fig.29 As shown, the first region A1, the sixth region A6 and the second region A2 are arranged in sequence from left to right with intervals. That is, the first region A1, the sixth region A6 and the second region A2 are arranged with intervals in the left-right direction. Therefore, when the flexible substrate 2 is not bent, the sixth region A6 is located between the first region A1 and the second region A2 when viewed in the up-down direction. In addition, when the flexible substrate 2 is not bent, the sixth region A6 is not in contact with the first region A1 and the second region A2 when viewed in the up-down direction. Therefore, when viewed in the up-down direction, the first region A1, the second region A2 and the sixth region A6 do not overlap with each other. In addition, when viewed in the up-down direction, the first piezoelectric film 31 has an 11th region A11 that does not overlap with the first deformation obstruction member 4, the second deformation obstruction member 5 and the third deformation obstruction member 12.

[0166] Here, a distance D16 in the left-right direction between the first area A1 and the sixth area A6 when the flexible base 2 is not bent is defined. Fig.29 As shown, the distance D16 in the left-right direction between the first area A1 and the sixth area A6 is the shortest distance between the portions where the first area A1 and the sixth area A6 do not contact each other. In the present embodiment, the right end of the first area A1 coincides with a portion of the right side of the first deformation preventing member 4. The right edge of the first deformation preventing member 4 extends in the front-to-back direction. In addition, the left end of the sixth area A6 coincides with a portion of the left side of the third deformation preventing member 12. The left edge of the third deformation preventing member 12 extends in the front-to-back direction. Therefore, the distance D16 in the left-right direction between the first area A1 and the sixth area A6 is the distance in the left-to-right direction between the right side of the first deformation preventing member 4 and the left side of the third deformation preventing member 12 as viewed in the up-down direction.

[0167] The distance D26 between the second area A2 and the sixth area A6 in the left-right direction when the flexible substrate 2 is not bent is defined. Fig.29As shown, the distance D26 in the left-right direction between the second area A2 and the sixth area A6 is the shortest distance between the parts where the second area A2 and the sixth area A6 do not contact each other. In the present embodiment, the left end of the second area A2 coincides with a portion of the left side of the second deformation preventing member 5. The left edge of the second deformation preventing member 5 extends in the front-to-back direction. In addition, the right end of the sixth area A6 coincides with a portion of the right side of the third deformation preventing member 12. The right edge of the third deformation preventing member 12 extends in the front-to-back direction. Therefore, the distance D26 in the left-right direction between the second area A2 and the sixth area A6 is the distance in the left-to-right direction between the left side of the second deformation preventing member 5 and the right side of the third deformation preventing member 12 as viewed in the up-down direction.

[0168] like Fig.29 As shown, when the flexible base material 2 is not bent, the distance D16 between the first area A1 and the sixth area A6 in the left-right direction is different from the distance D26 between the second area A2 and the sixth area A6 in the left-right direction. In the present embodiment, the distance D16 between the first area A1 and the sixth area A6 in the left-right direction is shorter than the distance D26 between the second area A2 and the sixth area A6 in the left-right direction.

[0169] Here, the bending angle θ of the flexible base material 2 at which the first deformation preventing member 4 and the third deformation preventing member 12 start to contact each other when the angle changes from 0 degrees to 180 degrees is set to θa1. In addition, the bending angle θ of the flexible base material 2 at which the second deformation preventing member 5 and the third deformation preventing member 12 start to contact each other when the angle changes from 0 degrees to 180 degrees is set to θa2. Since the distance D16 in the left-right direction between the first area A1 and the sixth area A6 is shorter than the distance D26 in the left-right direction between the second area A2 and the sixth area A6, θa1 is smaller than θa2. That is, in the present embodiment, when the bending angle θ of the flexible base material 2 is θa1 or θa2, the value of the first detection signal SigD1 is discontinuous.

[0170] When the value of the first detection signal SigD1 is discontinuous, the calculation circuit sets the bending angle θ of the flexible base material 2 to θa1 or θa2.

[0171] When the value of the first detection signal SigD1 is discontinuous, the operation circuit compares, for example, the absolute value of the difference between the first integrated value IV1 and the value associated with θa1 and the absolute value of the difference between the first integrated value IV1 and the value associated with θa2. When the absolute value of the difference between the first integrated value IV1 and the value associated with θa1 is smaller than the absolute value of the difference between the first integrated value IV1 and the value associated with θa2, the operation circuit sets the bending angle θ of the flexible base material 2 to θa1. In this case, the operation circuit corrects the first integrated value IV1 to the value associated with θa1. Alternatively, when the absolute value of the difference between the first integrated value IV1 and the value associated with θa2 is smaller than the absolute value of the difference between the first integrated value IV1 and the value associated with θa1, the operation circuit sets the bending angle θ of the flexible base material 2 to θa2. In this case, the operation circuit corrects the first integrated value IV1 to the value associated with θa2.

[0172] In addition, when the value of the first detection signal SigD1 is discontinuous, the operation circuit may also set the bending angle θ of the flexible base material 2 to θa1 or θa2 by other methods. For example, the operation circuit may determine whether the bending angle θ of the flexible base material 2 is set to θa1 or θa2 based on the value of the first detection signal SigD1 just before and / or just after the value of the first detection signal SigD1 becomes discontinuous.

[0173] According to the deformation detection sensor 1f, the bending angle of the substrate can be detected with further high accuracy. More specifically, in the state where the flexible substrate 2 is not bent, the distance D16 in the left-right direction between the first area A1 and the sixth area A6 is different from the distance D26 in the left-right direction between the second area A2 and the sixth area A6. Therefore, the value of the first detection signal SigD1 output by the first sensor 3 is discontinuous when the bending angle θ of the flexible substrate 2 is θa1 or θa2. θa1 is the bending angle θ of the flexible substrate 2 at which the first deformation hindering member 4 and the third deformation hindering member 12 begin to contact each other when the bending angle θ of the flexible substrate 2 is changed from 0 degrees to 180 degrees. θa2 is the bending angle θ of the flexible substrate 2 at which the second deformation hindering member 5 and the third deformation hindering member 12 begin to contact each other when the bending angle θ of the flexible substrate 2 is changed from 0 degrees to 180 degrees. Therefore, the operation circuit can set the bending angle θ of the flexible base material 2 to θa1 or θa2 when the value of the first detection signal SigD1 is discontinuous. At this time, the operation circuit can correct the first integrated value IV1 to a value associated with θa1 or θa2. Therefore, according to the deformation detection sensor 1f, the value of the first detection signal SigD1 in the range of θa1≤θ≤180 degrees can be made not to be affected by the noise N superimposed in the range of 0 degrees≤θ<θa1. In addition, according to the deformation detection sensor 1f, the value of the first detection signal SigD1 in the range of θa2≤θ≤180 degrees can be made not to be affected by the noise N superimposed in the range of 0 degrees≤θ<θa2. Therefore, according to the deformation detection sensor 1f, the bending angle θ of the flexible base material 2 can be detected with further better accuracy. As a result, according to the deformation detection sensor 1f, the bending angle of the base material can be detected with further better accuracy.

[0174] [Fifth Modification]

[0175] Hereinafter, a deformation detection sensor 1g according to a fifth modified example of the present invention will be described with reference to the drawings. Fig.30 1 is an exploded perspective view of a deformation detection sensor 1g according to a fifth modification. In addition, only the parts of the deformation detection sensor 1g according to the fifth modification that are different from the deformation detection sensor 1f according to the third embodiment will be described, and the description will be omitted below.

[0176] The deformation detection sensor 1g is different from the deformation detection sensor 1f in that the first deformation hindering member 4 is arranged on the first lower main surface LS3 of the first sensor 3, the second deformation hindering member 5 is arranged on the first lower main surface LS3 of the first sensor 3, and the third deformation hindering member 12 is arranged on the first lower main surface LS3 of the first sensor 3.

[0177] like Fig.30As shown, the first sensor 3 is provided on the substrate upper main surface US2 of the flexible substrate 2 such that the first lower main surface LS3 contacts the upper main surfaces of the first deformation preventing member 4 , the second deformation preventing member 5 , and the third deformation preventing member 12 .

[0178] In the deformation detection sensor 1g as described above, the same effect as that of the deformation detection sensor 1f is achieved. Thus, the third deformation blocking member 12 is provided on the first upper main surface US3 or the first lower main surface LS3 of the first sensor 3, where the first deformation blocking member 4 and the second deformation blocking member 5 are provided.

[0179] [Sixth Modification]

[0180] Hereinafter, a deformation detection sensor 1h according to a sixth modified example of the present invention will be described with reference to the drawings. Fig.31 It is a top view of the deformation detection sensor 1h according to the sixth modification as viewed in the downward direction. In addition, the deformation detection sensor 1h according to the sixth modification will only be described with respect to the parts that are different from the deformation detection sensor 1f according to the third embodiment, and the description will be omitted hereinafter.

[0181] The deformation detection sensor 1h is different from the deformation detection sensor 1f in that the 7th area A7 having the 1st area A1 of the first deformation hindering member 4 and the 6th area A6 of the third deformation hindering member 12 overlap each other, and the 8th area A8 having the 2nd area A2 of the second deformation hindering member 5 and the 6th area A6 of the third deformation hindering member 12 overlap each other.

[0182] like Fig.31 As shown in FIG. 1 , the first area A1 and the sixth area A6 overlap each other in the seventh area A7. In addition, the first area A1 and the sixth area A6 contact each other in the seventh area A7. However, when the flexible base 2 is not bent, the sixth area A6 has a fourth portion P4 that does not contact the first area A1 when viewed in the up-down direction. In this modification, the fourth portion P4 is located in front of the seventh area A7.

[0183] like Fig.31 As shown in FIG. 1 , the second area A2 and the sixth area A6 overlap each other in the eighth area A8. In addition, the second area A2 and the sixth area A6 contact each other in the eighth area A8. However, when the flexible base 2 is not bent, the sixth area A6 has a fifth portion P5 that does not contact the second area A2 when viewed in the vertical direction. In this modification, the fifth portion P5 is located in front of the eighth area A8.

[0184] The deformation detection sensor 1h described above also has the same effect as the deformation detection sensor 1f. Thus, when the flexible base 2 is not bent, the sixth area A6 only needs to have the fourth portion P4 and the fifth portion P5 that are not in contact with the first area A1 and the second area A2, respectively, when viewed in the up-down direction.

[0185] [Seventh Modification]

[0186] Hereinafter, a deformation detection sensor 1i according to a seventh modified example of the present invention will be described with reference to the drawings. Fig.32 It is a top view of the deformation detection sensor 1i according to the seventh modification as viewed in the downward direction. In addition, the deformation detection sensor 1i according to the seventh modification will only be described for the parts that are different from the deformation detection sensor 1h according to the sixth modification, and the description will be omitted hereinafter.

[0187] The deformation detection sensor 1 i is different from the deformation detection sensor 1 h in that the first deformation preventing member 4 , the second deformation preventing member 5 , and the third deformation preventing member 12 are included in a single member 9 .

[0188] like Fig.32 As shown, the left portion of the member 9 and the central portion of the member 9 are connected in the seventh region A7. The central portion of the member 9 and the right portion of the member 9 are connected in the eighth region A8. In addition, the member 9 has flexibility in the eighth region A8.

[0189] In the deformation detection sensor 1i as described above, the same effect as that of the deformation detection sensor 1h is achieved. In addition, in this modification, an example is shown in which the first deformation preventing member 4, the second deformation preventing member 5, and the third deformation preventing member 12 are all included in a single member 9, but at least two of the first deformation preventing member 4, the second deformation preventing member 5, and the third deformation preventing member 12 may be included in a single member 9.

[0190] [Fourth embodiment]

[0191] Hereinafter, a deformation detection sensor 1j according to a fourth embodiment of the present invention will be described with reference to the drawings. Fig.33 1 is an exploded perspective view of a deformation detection sensor 1j according to a fourth embodiment. In addition, only the parts of the deformation detection sensor 1j according to the fourth embodiment that are different from the deformation detection sensor 1f according to the third embodiment will be described, and the description will be omitted below.

[0192] The deformation detection sensor 1j is different from the deformation detection sensor 1f in that the first sensor 3 also includes the first electrode 34, the first upper electrode 32 is the first signal electrode, the first lower electrode 33 is the ground electrode, and the first upper electrode 32 does not cover the entire main surface US31 of the first piezoelectric film 31.

[0193] like Fig.33 As shown, the flexible base 2 is bent at a first bending line L1 and a second bending line L2 extending in the front-rear direction.

[0194] like Fig.33 As shown, the first electrode 34 is provided on the first piezoelectric film upper main surface US31 of the first piezoelectric film 31. The first electrode 34 is the third signal electrode. The first electrode 34 has an upper main surface and a lower main surface arranged in the up-down direction. The third detection signal SigD3 corresponding to the deformation of the bending section CS2 of the flexible substrate 2 is output from the first electrode 34. The first electrode 34 includes an adhesive layer not shown. And, through the adhesive layer, the first electrode 34 is fixed to the first piezoelectric film upper main surface US31 of the first piezoelectric film 31. The upper main surface of the first electrode 34 is the first upper main surface US3 of the first sensor 3.

[0195] like Fig.33 As shown in FIG. 1 , the first upper electrode 32 and the first electrode 34 are arranged in sequence from left to right with a gap therebetween. Therefore, when the flexible substrate 2 is not bent, the first upper electrode 32 and the first electrode 34 do not contact each other. In addition, the first upper electrode 32 and the first electrode 34 are arranged so as not to contact each other even when the flexible substrate 2 is bent. That is, the first upper electrode 32 and the first electrode 34 do not contact each other.

[0196] like Fig.33 As shown, in a state where the flexible base 2 is not bent, the first upper electrode 32 overlaps with the first deformation preventing member 4 and the third deformation preventing member 12 when viewed in the up-down direction.

[0197] like Fig.33 As shown, in a state where the flexible base 2 is not bent, the first electrode 34 overlaps with the first deformation preventing member 4 and the third deformation preventing member 12 when viewed in the up-down direction.

[0198] According to the deformation detection sensor 1j, the bending angle of the substrate bent at a plurality of bending lines can be detected with good accuracy. More specifically, the flexible substrate 2 is bent at the first bending line L1 and the second bending line L2, respectively. When the flexible substrate 2 is not bent, the first upper electrode 32 overlaps with the first deformation blocking member 4 and the third deformation blocking member 12, respectively, when viewed in the up-down direction. According to the deformation detection sensor 1j, when the flexible substrate 2 is bent at the first bending line L1, the bending angle θ of the flexible substrate 2 can be detected with good accuracy by the first detection signal SigD1 output from the first upper electrode 32. In addition, according to the deformation detection sensor 1j, when the flexible substrate 2 is bent at the second bending line L2, the bending angle θ of the flexible substrate 2 can be detected with good accuracy by the third detection signal SigD3 output from the first electrode 34. As a result, according to the deformation detection sensor 1j, the bending angle of the substrate bent at a plurality of bending lines can be detected with good accuracy.

[0199] [Eighth Modification]

[0200] Hereinafter, a deformation detection sensor 1k according to an eighth modified example of the present invention will be described with reference to the drawings. Fig.34 1 is an exploded perspective view of a deformation detection sensor 1k according to an eighth modification. In addition, only the parts of the deformation detection sensor 1k according to the eighth modification that are different from the deformation detection sensor 1j according to the fourth embodiment will be described, and the description will be omitted below.

[0201] The deformation detection sensor 1k is different from the deformation detection sensor 1j in that the first deformation hindering member 4 is arranged on the first lower main surface LS3 of the first sensor 3, the second deformation hindering member 5 is arranged on the first lower main surface LS3 of the first sensor 3, the third deformation hindering member 12 is arranged on the first lower main surface LS3 of the first sensor 3, the first upper electrode 32 is a ground electrode and the first lower electrode 33 is a first signal electrode, the first lower electrode 33 does not cover the entire first piezoelectric film lower main surface LS31 of the first piezoelectric film 31, and the first electrode 34 is arranged on the first piezoelectric film lower main surface LS31 of the first piezoelectric film 31.

[0202] The first electrode 34 includes an adhesive layer (not shown). Fig.34 As shown, the first electrode 34 is fixed to the first piezoelectric film lower principal surface LS31 of the first piezoelectric film 31 via the adhesive layer. The lower principal surface of the first electrode 34 is the first lower principal surface LS3 of the first sensor 3.

[0203] like Fig.34As shown in FIG. 1 , the first lower electrode 33 and the first electrode 34 are arranged in sequence from left to right with a gap therebetween. Therefore, when the flexible substrate 2 is not bent, the first lower electrode 33 and the first electrode 34 do not contact each other. In addition, the first lower electrode 33 and the first electrode 34 are arranged so as not to contact each other even when the flexible substrate 2 is bent. That is, the first lower electrode 33 and the first electrode 34 do not contact each other.

[0204] like Fig.34 As shown, in a state where the flexible base 2 is not bent, the first lower electrode 33 overlaps with the first deformation preventing member 4 and the third deformation preventing member 12 when viewed in the up-down direction.

[0205] like Fig.34 As shown, in a state where the flexible base 2 is not bent, the first electrode 34 overlaps with the first deformation preventing member 4 and the third deformation preventing member 12 when viewed in the up-down direction.

[0206] The above-described deformation detection sensor 1k also exhibits the same effects as those of the deformation detection sensor 1j.

[0207] [Other embodiments]

[0208] The deformation detection sensor of the present invention is not limited to the deformation detection sensors 1, 1a to 1k, and can be changed within the scope of the main purpose. In addition, the structures of the deformation detection sensors 1, 1a to 1k can be arbitrarily combined. In addition, the electronic device of the present invention is not limited to the electronic device 100, 100a to 100k having the deformation detection sensors 1, 1a to 1k, and can be changed within the scope of the main purpose. In addition, the structures of the electronic devices 100, 100a to 100k can be arbitrarily combined.

[0209] Furthermore, the flexible base material 2 may not have a rectangular shape when viewed in the vertical direction.

[0210] Furthermore, the flexible base material 2 may not have long sides extending in the left-right direction and short sides extending in the front-rear direction when viewed in the up-down direction.

[0211] The flexible substrate 2 is not limited to an organic EL display, but the flexible substrate 2 has only to be flexible and have a substrate upper principal surface US2 and a substrate lower principal surface LS2 arranged in the vertical direction.

[0212] Furthermore, each of the first sensor 3 and the second sensor 11 may not have a rectangular shape when viewed in the up-down direction.

[0213] Furthermore, when viewed in the up-down direction, each of the first sensor 3 and the second sensor 11 may not have a long side extending in the left-right direction and a short side extending in the front-rear direction.

[0214] In addition, each of the first piezoelectric film 31 and the second piezoelectric film 111 may not have a rectangular shape when viewed in the up-down direction.

[0215] Furthermore, when viewed in the up-down direction, each of the first piezoelectric film 31 and the second piezoelectric film 111 may not have a long side extending in the left-right direction and a short side extending in the front-back direction.

[0216] Alternatively, each of the first piezoelectric film 31 and the second piezoelectric film 111 may be a film containing polylactic acid stretched in at least a uniaxial direction.

[0217] In addition, the first piezoelectric film 31 and the second piezoelectric film 111 may not have a piezoelectric constant of d14. The first piezoelectric film 31 and the second piezoelectric film 111 may have a piezoelectric constant of d31, for example. The first piezoelectric film 31 and the second piezoelectric film 111 having a piezoelectric constant of d31 may be, for example, PVDF (polyvinylidene fluoride) films. In addition, the first piezoelectric film 31 and the second piezoelectric film 111 may be piezoelectric ceramics, for example.

[0218] In addition, the polarity of the charge generated by the first piezoelectric film 31 and the second piezoelectric film 111 when the first piezoelectric film 31 and the second piezoelectric film 111 are stretched respectively in the left-right direction of the piezoelectric film may be the same as the polarity of the charge generated by the first piezoelectric film 31 and the second piezoelectric film 111 when the first piezoelectric film 31 and the second piezoelectric film 111 are stretched respectively in the front-back direction of the piezoelectric film.

[0219] In addition, when the flexible substrate 2 is not bent, the uniaxial stretching direction OD of each of the first piezoelectric film 31 and the second piezoelectric film 111 may form an angle of 45 degrees with respect to the first bending line L1 when viewed in the up-down direction. The 45 degrees includes, for example, an angle of about 45 degrees ± 10 degrees. In addition, the 45 degrees includes an angle of about 225 degrees ± 10 degrees (about -135 degrees ± 10 degrees).

[0220] Furthermore, when the flexible substrate 2 is not bent, the angle formed by the uniaxial stretching direction OD of each of the first piezoelectric film 31 and the second piezoelectric film 111 with respect to the first bending line L1 is not limited to 45 degrees or −45 degrees when viewed in the vertical direction.

[0221] Alternatively, the first upper electrode 32 may be a first signal electrode, and the first lower electrode 33 may be a ground electrode.

[0222] In addition, the first deformation preventing member 4 may not have a rectangular shape when viewed in the up-down direction.

[0223] Furthermore, the first deformation preventing member 4 may not have short sides extending in the left-right direction and long sides extending in the front-rear direction when viewed in the up-down direction.

[0224] In addition, the first deformation preventing member 4 may not be in contact with the base upper main surface US2 of the flexible base 2 .

[0225] In addition, the second deformation preventing member 5 may not have a rectangular shape when viewed in the up-down direction.

[0226] Furthermore, the second deformation preventing member 5 may not have short sides extending in the left-right direction and long sides extending in the front-rear direction when viewed in the up-down direction.

[0227] In addition, the second deformation preventing member 5 may not be in contact with the base upper main surface US2 of the flexible base 2 .

[0228] In addition, the first deformation preventing member 4 and the second deformation preventing member 5 may not be arranged at intervals in the left-right direction.

[0229] Furthermore, the first area A1 may not be located on the left side of the first bending line L1 when viewed in the up-down direction.

[0230] Furthermore, the second area A2 may not be located on the right side of the first bending line L1 when viewed in the up-down direction.

[0231] In addition, the first area A1 and the second area A2 may not be arranged at intervals in the left-right direction.

[0232] Furthermore, when the flexible base 2 is not bent, the distance D1 between the first area A1 and the second area A2 in the left-right direction may not be shorter than the length DLR31 of the first piezoelectric film 31 in the left-right direction.

[0233] In addition, the first position PO1 is an arbitrary position among the positions in the left-right direction where the first area A1 exists.

[0234] In addition, the second position PO2 is an arbitrary position among the positions in the left-right direction where the second area A2 exists.

[0235] Furthermore, when the flexible base 2 is not bent, the length DFB4 of the first deformation preventing member 4 at the first position PO1 in the front-rear direction may not be longer than the length DFB311 of the first piezoelectric film 31 at the first position PO1 in the front-rear direction.

[0236] Furthermore, when the flexible base 2 is not bent, the length DFB5 of the second deformation preventing member 5 at the second position PO2 in the front-rear direction may not be longer than the length DFB312 of the first piezoelectric film 31 at the second position PO2 in the front-rear direction.

[0237] Furthermore, the calculation circuit may not be an essential component.

[0238] In addition, the electronic devices 100 and 100a to 100k are not limited to foldable smartphones.

[0239] In addition, the first housing 6 is not limited to a box. In addition, the first housing 6 may not have a rectangular parallelepiped shape.

[0240] In addition, the second housing 7 is not limited to a box. In addition, the second housing 7 may not have a rectangular parallelepiped shape.

[0241] In addition, in the deformation detection sensor 1b, the third portion P3 is not limited to being located in front of the fifth area A5.

[0242] In the strain detection sensor 1 c , the left portion of the member 8 and the right portion of the member 8 may be connected in a region not overlapping with the first piezoelectric film 31 when viewed in the up-down direction.

[0243] In addition, in the strain detection sensor 1 d , the second upper electrode 112 may be a second signal electrode, and the second lower electrode 113 may be a ground electrode.

[0244] In addition, in the deformation detection sensor 1 e , the second upper electrode 112 may be a ground electrode, and the second lower electrode 113 may be a second signal electrode.

[0245] Furthermore, in the deformation detection sensor 1 f , the third deformation preventing member 12 may not have a rectangular shape when viewed in the up-down direction.

[0246] Furthermore, in the deformation detection sensor 1 f , the third deformation preventing member 12 may not have short sides extending in the left-right direction and long sides extending in the front-rear direction when viewed in the up-down direction.

[0247] In the deformation detection sensor 1 f , the third deformation preventing member 12 may or may not be in contact with the substrate upper main surface US2 of the flexible substrate 2 .

[0248] In addition, in the deformation detection sensor 1f, the first deformation preventing member 4, the third deformation preventing member 12, and the second deformation preventing member 5 may be arranged in sequence from left to right without being spaced apart from each other.

[0249] In addition, in the strain detection sensor 1f, the first area A1, the sixth area A6, and the second area A2 may be arranged in sequence from left to right without being spaced apart from each other.

[0250] In addition, in the deformation detection sensor 1f, the distance D16 between the first area A1 and the sixth area A6 in the left-right direction may be longer than the distance D26 between the second area A2 and the sixth area A6 in the left-right direction. In this case, since the distance D16 between the first area A1 and the sixth area A6 in the left-right direction is longer than the distance D26 between the second area A2 and the sixth area A6 in the left-right direction, θa1 is larger than θa2. In this case, the bending angle of the substrate can be detected with further high accuracy.

[0251] In addition, in the deformation detection sensor 1h, the fourth portion P4 is not limited to being located in front of the seventh area A7.

[0252] In addition, in the deformation detection sensor 1h, the fifth portion P5 is not limited to being located in front of the eighth area A8.

[0253] In the deformation detection sensor 1i, when viewed in the up-down direction, the left portion of the member 9 and the central portion of the member 9 may be connected in a region that does not overlap with the first piezoelectric film 31. In the deformation detection sensor 1i, the central portion of the member 9 and the right portion of the member 9 may be connected in a region that does not overlap with the first piezoelectric film 31.

[0254] In addition, in the strain detection sensor 1 j , the first upper electrode 32 and the first electrode 34 may be arranged in sequence from right to left with a gap therebetween.

[0255] In addition, in the strain detection sensor 1 k , the first lower electrode 33 and the first electrode 34 may be arranged in sequence from right to left with a gap therebetween.

[0256] In addition, in the deformation detection sensors 1j and 1k, the first bending angle θ1 of the flexible base material 2 and the second bending angle θ2 of the flexible base material 2 may be defined as follows. That is, the first bending angle θ1 of the flexible base material 2 may be defined as the angle formed by the first portion P1 of the flexible base material 2 and the second portion P2 of the flexible base material 2 when viewed in the direction in which the first bending line L1 extends. The second bending angle θ2 of the flexible base material 2 may be defined as the angle formed by the first portion P1 of the flexible base material 2 and the second portion P2 of the flexible base material 2 when viewed in the direction in which the second bending line L2 extends. In this case, according to the deformation detection sensor 1k, the first bending angle θ1 of the flexible base material 2 can be detected with high accuracy by the first detection signal SigD1 output from the first upper electrode 32 or the first lower electrode 33. In addition, the second bending angle θ2 of the flexible base material 2 can be detected with high accuracy by the third detection signal SigD3 output from the first electrode 34.

[0257] The present invention has the following configuration. (1)

[0259] A deformation detection sensor, wherein:

[0260] The deformation detection sensor has:

[0261] A flexible substrate having a substrate upper main surface and a substrate lower main surface arranged in a vertical direction and a bending section that bends when bent at a bending line;

[0262] a first sensor that outputs a first detection signal corresponding to the deformation of the bending section and is disposed on the upper main surface of the substrate, and has a first upper main surface and a first lower main surface arranged in the up-down direction;

[0263] a first deformation preventing member; and

[0264] The second deformation hindering member,

[0265] The first sensor comprises:

[0266] a first piezoelectric film having a first piezoelectric film upper principal surface and a first piezoelectric film lower principal surface arranged in the up-down direction;

[0267] a first upper electrode disposed on the upper main surface of the first piezoelectric film; and

[0268] a first lower electrode disposed on the lower main surface of the first piezoelectric film,

[0269] The first deformation preventing member is provided on the first upper main surface or the first lower main surface,

[0270] The first deformation preventing member has a first region overlapping with the first piezoelectric film when viewed in the up-down direction.

[0271] The second deformation preventing member is provided on the first upper main surface or the first lower main surface where the first deformation preventing member is provided,

[0272] The second deformation preventing member has a second region overlapping with the first piezoelectric film when viewed in the up-down direction.

[0273] The first region and the second region have portions that are not in contact with each other when viewed in the up-down direction in a state where the flexible base is not bent. (2)

[0275] The deformation detection sensor according to (1), wherein:

[0276] The first deformation preventing member has a third region which is in contact with the upper main surface of the substrate and does not overlap with the first piezoelectric film when viewed in the up-down direction.

[0277] The second deformation preventing member has a fourth region that is in contact with the upper main surface of the substrate and does not overlap with the first piezoelectric film when viewed in the up-down direction. (3)

[0279] The deformation detection sensor according to (1) or (2), wherein:

[0280] The first deformation preventing member is provided on the first upper main surface,

[0281] The second deformation preventing member is provided on the first upper main surface. (4)

[0283] The deformation detection sensor according to any one of (1) to (3), wherein:

[0284] The first area and the second area are arranged at intervals in the left-right direction,

[0285] When the flexible base is not bent, a distance between the first region and the second region in the left-right direction is shorter than a length of the first piezoelectric film in the left-right direction. (5)

[0287] The deformation detection sensor according to any one of (1) to (4), wherein:

[0288] The position in the left-right direction where the first region exists is defined as a first position,

[0289] The position in the left-right direction where the second area exists is defined as a second position,

[0290] There is a first position where, in a state where the flexible substrate is not bent, the length of the first deformation preventing member in the front-to-back direction at the first position is longer than the length of the first piezoelectric film in the front-to-back direction at the first position,

[0291] There is a second position where the maximum length of the second deformation preventing member in the front-rear direction is longer than the length of the first piezoelectric film in the front-rear direction when the flexible base is not bent. (6)

[0293] The deformation detection sensor according to any one of (1) to (5), wherein:

[0294] The deformation detection sensor further comprises a third deformation hindering member.

[0295] The third deformation preventing member is provided on the first upper main surface or the first lower main surface where the first deformation preventing member and the second deformation preventing member are provided,

[0296] The third deformation preventing member has a fifth region overlapping with the first piezoelectric film when viewed in the up-down direction.

[0297] When the flexible substrate is not bent, the fifth region is located between the first region and the second region when viewed in the up-down direction.

[0298] The fifth region has a portion that is not in contact with either the first region or the second region when viewed in the up-down direction in a state where the flexible base is not bent. (7)

[0300] The deformation detection sensor according to (6), wherein:

[0301] The first area, the fifth area, and the second area are arranged at intervals in the left-right direction.

[0302] When the flexible base is not bent, a distance between the first region and the fifth region in the left-right direction is different from a distance between the second region and the fifth region in the left-right direction. (8)

[0304] The deformation detection sensor according to (6) or (7), wherein:

[0305] The third deformation preventing member is harder than the first piezoelectric film. (9)

[0307] The deformation detection sensor according to any one of (6) to (8), wherein:

[0308] The first sensor further includes a first electrode provided on a main surface of the first piezoelectric film.

[0309] When the flexible substrate is not bent, the first upper electrode overlaps with the first deformation preventing member and the third deformation preventing member when viewed in the up-down direction.

[0310] When the flexible substrate is not bent, the first electrode overlaps with the second deformation preventing member and the third deformation preventing member when viewed in the up-down direction.

[0311] The first electrode and the first upper electrode do not contact each other. (10)

[0313] The deformation detection sensor according to any one of (6) to (8), wherein:

[0314] The first sensor further includes a first electrode provided on the lower main surface of the first piezoelectric film.

[0315] When the flexible substrate is not bent, the first lower electrode overlaps with the first deformation preventing member and the third deformation preventing member when viewed in the up-down direction.

[0316] When the flexible substrate is not bent, the first electrode overlaps with the second deformation preventing member and the third deformation preventing member when viewed in the up-down direction.

[0317] The first electrode and the first lower electrode do not contact each other. (11)

[0319] The deformation detection sensor according to any one of (1) to (10), wherein:

[0320] The first upper electrode is a ground electrode electrically connected to a ground potential. (12)

[0322] The deformation detection sensor according to any one of (1) to (11), wherein:

[0323] The first piezoelectric film has a piezoelectric constant of d14. (13)

[0325] The deformation detection sensor according to any one of (1) to (12), wherein:

[0326] The first piezoelectric film is a film of polylactic acid stretched at least in a uniaxial direction.

[0327] When the flexible substrate is not bent, the uniaxial stretching direction of the first piezoelectric film forms an angle of 45 degrees or -45 degrees with respect to the bending line when viewed in the up-down direction. (14)

[0329] The deformation detection sensor according to any one of (1) to (13), wherein:

[0330] The first deformation hindering member is harder than the first piezoelectric film.

[0331] The second deformation preventing member is harder than the first piezoelectric film. (15)

[0333] The deformation detection sensor according to any one of (1) to (14), wherein:

[0334] The deformation detection sensor further includes a second sensor that outputs a second detection signal corresponding to the deformation of the bending section, the second sensor being provided on the upper main surface of the substrate or the lower main surface of the substrate and having a second upper main surface and a second lower main surface arranged in the up-down direction.

[0335] The second sensor comprises:

[0336] a second piezoelectric film having a second piezoelectric film upper principal surface and a second piezoelectric film lower principal surface arranged in the up-down direction;

[0337] a second upper electrode disposed on the upper main surface of the second piezoelectric film; and

[0338] a second lower electrode, which is provided on the lower main surface of the second piezoelectric film,

[0339] When the flexible base is not bent, the second sensor does not overlap with the first sensor, the first deformation preventing member, and the second deformation preventing member when viewed in the up-down direction. (16)

[0341] The deformation detection sensor according to any one of (1) to (15), wherein:

[0342] The first deformation preventing member and the second deformation preventing member are included in a single member. (17)

[0344] The deformation detection sensor according to any one of (6) to (10), wherein:

[0345] At least two of the first deformation preventing member, the second deformation preventing member, and the third deformation preventing member are included in a single member. (18)

[0347] An electronic device, wherein

[0348] This electronic device includes the deformation detection sensor described in any one of (1) to (17).

[0349] Description of Reference Numerals

[0350] 1, 10, 1a, 1b, 1c, 1d, 1e, 1f, 1g, 1h, 1i, 1j, 1k, deformation detection sensor; 2, flexible substrate; 3, first sensor; 4, first deformation blocking member; 5, second deformation blocking member; 6, first shell; 7, second shell; 8, 9, member; 11, second sensor; 12, third deformation blocking member; 31, first piezoelectric film; 32, first upper electrode; 33, first lower electrode; 34, first electrode ; 100, 100a, 100b, 100c, 100d, 100e, 100f, 100g, 100h, 100i, 100j, 100k, electronic device; 111, second piezoelectric film; 112, second upper electrode; 113, second lower electrode; A1, first region; A2, second region; A3, third region; A4, fourth region; A5, fifth region; A6, sixth region; A7, seventh region; A8, eighth region; CS2, bending interval; D1, D16, D26, distance; IV1, first integral value; IV2, second integral value; L1, first bending line; L2, second bending line; LS11, second lower main surface; LS111, second piezoelectric film lower main surface; LS2, substrate lower main surface; LS3, first lower main surface; LS31, first piezoelectric film lower main surface; N, noise; NCS1, NCS3, non-bending interval; OD, uniaxial stretching direction; P1, first part points; P2, the second part; P3, the third part; P4, the fourth part; P5, the fifth part; PO1, the first position; PO2, the second position; SigD1, the first detection signal; SigD2, the second detection signal; SigD3, the third detection signal; US11, the second upper main surface; US111, the second piezoelectric film upper main surface; US2, the substrate upper main surface; US3, the first upper main surface; US31, the first piezoelectric film upper main surface; θ, the bending angle.

Claims

1. A deformation detection sensor, wherein: The deformation detection sensor has: A flexible substrate having a substrate upper main surface and a substrate lower main surface arranged in a vertical direction and a bending section that bends when bent at a bending line; a first sensor that outputs a first detection signal corresponding to the deformation of the bending section and is disposed on the upper main surface of the substrate, and has a first upper main surface and a first lower main surface arranged in the up-down direction; a first deformation hindering member; as well as The second deformation hindering member, The first sensor comprises: a first piezoelectric film having a first piezoelectric film upper principal surface and a first piezoelectric film lower principal surface arranged in the up-down direction; a first upper electrode disposed on the upper main surface of the first piezoelectric film; and a first lower electrode disposed on the lower main surface of the first piezoelectric film, The first deformation preventing member is provided on the first upper main surface or the first lower main surface, The first deformation preventing member has a first region overlapping with the first piezoelectric film when viewed in the up-down direction. The second deformation preventing member is provided on the first upper main surface or the first lower main surface where the first deformation preventing member is provided, The second deformation preventing member has a second region overlapping with the first piezoelectric film when viewed in the up-down direction. The first region and the second region have portions that are not in contact with each other when viewed in the up-down direction in a state where the flexible base is not bent.

2. The deformation detection sensor according to claim 1, wherein: The first deformation preventing member has a third region which is in contact with the upper main surface of the substrate and does not overlap with the first piezoelectric film when viewed in the up-down direction. The second deformation preventing member has a fourth region that is in contact with the upper main surface of the substrate and does not overlap with the first piezoelectric film when viewed in the up-down direction.

3. The deformation detection sensor according to claim 1 or 2, wherein: The first deformation preventing member is provided on the first upper main surface, The second deformation preventing member is provided on the first upper main surface.

4. The deformation detection sensor according to any one of claims 1 to 3, wherein: The first area and the second area are arranged at intervals in the left-right direction, When the flexible base is not bent, a distance between the first region and the second region in the left-right direction is shorter than a length of the first piezoelectric film in the left-right direction.

5. The deformation detection sensor according to any one of claims 1 to 4, wherein: The position in the left-right direction where the first region exists is defined as a first position, The position in the left-right direction where the second area exists is defined as a second position, There is a first position where, in a state where the flexible substrate is not bent, the length of the first deformation preventing member in the front-to-back direction at the first position is longer than the length of the first piezoelectric film in the front-to-back direction at the first position, There is a second position where, in a state where the flexible base is not bent, the length of the second deformation preventing member in the front-rear direction is longer than the length of the first piezoelectric film in the front-rear direction.

6. The deformation detection sensor according to any one of claims 1 to 5, wherein: The deformation detection sensor further comprises a third deformation hindering member. The third deformation preventing member is provided on the first upper main surface or the first lower main surface where the first deformation preventing member and the second deformation preventing member are provided, The third deformation preventing member has a fifth region overlapping with the first piezoelectric film when viewed in the up-down direction. When the flexible substrate is not bent, the fifth region is located between the first region and the second region when viewed in the up-down direction. The fifth region has a portion that is not in contact with either the first region or the second region when viewed in the up-down direction in a state where the flexible base is not bent.

7. The deformation detection sensor according to claim 6, wherein: The first area, the fifth area, and the second area are arranged at intervals in the left-right direction. When the flexible base is not bent, a distance between the first region and the fifth region in the left-right direction is different from a distance between the second region and the fifth region in the left-right direction.

8. The deformation detection sensor according to claim 6 or 7, wherein: The third deformation preventing member is harder than the first piezoelectric film.

9. The deformation detection sensor according to any one of claims 6 to 8, wherein: The first sensor further includes a first electrode provided on a main surface of the first piezoelectric film. When the flexible substrate is not bent, the first upper electrode overlaps with the first deformation preventing member and the third deformation preventing member when viewed in the up-down direction. When the flexible substrate is not bent, the first electrode overlaps with the second deformation preventing member and the third deformation preventing member when viewed in the up-down direction. The first electrode and the first upper electrode do not contact each other.

10. The deformation detection sensor according to any one of claims 6 to 8, wherein: The first sensor further includes a first electrode provided on the lower main surface of the first piezoelectric film. When the flexible substrate is not bent, the first lower electrode overlaps with the first deformation preventing member and the third deformation preventing member when viewed in the up-down direction. When the flexible substrate is not bent, the first electrode overlaps with the second deformation preventing member and the third deformation preventing member when viewed in the up-down direction. The first electrode and the first lower electrode do not contact each other.

11. The deformation detection sensor according to any one of claims 1 to 10, wherein: The first upper electrode is a ground electrode electrically connected to a ground potential.

12. The deformation detection sensor according to any one of claims 1 to 11, wherein: The first piezoelectric film has a piezoelectric constant of d14.

13. The deformation detection sensor according to any one of claims 1 to 12, wherein: The first piezoelectric film is a film of polylactic acid stretched at least in a uniaxial direction. When the flexible substrate is not bent, the uniaxial stretching direction of the first piezoelectric film forms an angle of 45 degrees or -45 degrees with respect to the bending line when viewed in the up-down direction.

14. The deformation detection sensor according to any one of claims 1 to 13, wherein: The first deformation hindering member is harder than the first piezoelectric film. The second deformation preventing member is harder than the first piezoelectric film.

15. The deformation detection sensor according to any one of claims 1 to 14, wherein: The deformation detection sensor further includes a second sensor that outputs a second detection signal corresponding to the deformation of the bending section, the second sensor being provided on the upper main surface of the substrate or the lower main surface of the substrate and having a second upper main surface and a second lower main surface arranged in the up-down direction. The second sensor comprises: a second piezoelectric film having a second piezoelectric film upper principal surface and a second piezoelectric film lower principal surface arranged in the up-down direction; a second upper electrode disposed on the upper main surface of the second piezoelectric film; and a second lower electrode, which is provided on the lower main surface of the second piezoelectric film, When the flexible base is not bent, the second sensor does not overlap with the first sensor, the first deformation preventing member, and the second deformation preventing member when viewed in the up-down direction.

16. The deformation detection sensor according to any one of claims 1 to 15, wherein: The first deformation preventing member and the second deformation preventing member are included in a single member.

17. The deformation detection sensor according to any one of claims 6 to 10, wherein: At least two of the first deformation preventing member, the second deformation preventing member, and the third deformation preventing member are included in a single member.

18. An electronic device, wherein: This electronic device includes the deformation detection sensor according to any one of claims 1 to 17.

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