Sensor and electronic apparatus

Abstract

This sensor is flexible and is provided with: a first plate-like member; a first adhesive member; a piezoelectric film that has an upper main surface and a lower main surface; a first electrode that is provided on the upper main surface; a second electrode that is provided on the lower main surface; a second adhesive member; and a second plate-like member. The first plate-like member has an operation surface for receiving a pressing operation. The first adhesive member fixes the first electrode to the first plate-like member. The second adhesive member fixes the second plate-like member to the second electrode. The first plate-like member, the first adhesive member, the first electrode, the piezoelectric film, the second electrode, the second adhesive member, and the second plate-like member are arranged in the stated order in the downward direction. The elastic modulus of the second adhesive member is higher than the elastic modulus of the first adhesive member.

Description

Sensors and Electronic Devices

[0001] The present invention relates to a sensor and electronic device that detects deformation of a measurement object.

[0002] A known example of a conventional sensor-related invention is the pressure detection sensor described in Patent Document 1. The pressure detection sensor described in Patent Document 1 includes a protective sheet, a detection unit, and a sensor. The sensor includes a piezoelectric film. The protective sheet is made of a flexible material and functions as an operation surface on which a user performs a pressing operation using a pen, the user's own finger, or the like. The detection unit is connected to the sensor. When a user performs a pressing operation on the protective sheet, the strain applied to the protective sheet is transmitted to the sensor. This causes the piezoelectric film to generate an electric charge, and the sensor outputs a voltage. The detection unit detects the voltage output by the sensor.

[0003] International Publication No. 2018 / 221288

[0004] When attaching a sensor to an operation surface, the piezoelectric film may not be easily deformed depending on the adhesive conditions, which may reduce the detection sensitivity of the sensor.

[0005] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a sensor and an electronic device that can suppress a decrease in detection sensitivity.

[0006] A sensor according to one embodiment of the present invention is a flexible sensor comprising: a first plate-shaped member; a first adhesive member; a piezoelectric film having an upper main surface and a lower main surface; a first electrode provided on the upper main surface; a second electrode provided on the lower main surface; a second adhesive member; and a second plate-shaped member, wherein the first plate-shaped member has an operation surface that accepts a pressing operation; the first adhesive member fixes the first electrode to the first plate-shaped member; and the second adhesive member fixes the second plate-shaped member to the second electrode; the first plate-shaped member, the first adhesive member, the first electrode, the piezoelectric film, the second electrode, the second adhesive member, and the second plate-shaped member are arranged in this order downward; and the elastic modulus of the second adhesive member is higher than the elastic modulus of the first adhesive member.

[0007] The second adhesive member has a higher elastic modulus than the first adhesive member. Therefore, when a user presses the operation surface, the piezoelectric film is more likely to deform in response to the downward bending of the second plate-like member than the downward bending of the first plate-like member. That is, the piezoelectric film primarily detects the deformation of the second plate-like member. In this case, the piezoelectric film undergoes appropriate deformation in response to the pressing operation on the operation surface, preventing a decrease in detection sensitivity.

[0008] According to the sensor and electronic device of the present invention, it is possible to suppress a decrease in detection sensitivity.

[0009] FIG. 1 is an exploded perspective view of electronic device 10. FIG. 2 is a cross-sectional view of sensor 1. FIG. 3 is a cross-sectional view of electronic device 10 taken along line A-A. FIG. 4 is a plan view of piezoelectric film 14 viewed from below. FIG. 5 is a diagram showing an example of the amount of deformation of sensor 50 according to a comparative example. FIG. 6 is a diagram showing an example of the amount of deformation of sensor 1. FIG. 7 is a cross-sectional view of electronic device 10 taken along line A-A, which includes support members 3a and 3b.

[0010] [First Embodiment] A sensor 1 and an electronic device 10 according to a first embodiment of the present invention will be described below with reference to the drawings. Fig. 1 is an exploded perspective view of the electronic device 10. Fig. 2 is a cross-sectional view of the sensor 1. Fig. 3 is a cross-sectional view of the electronic device 10 taken along line A-A. Fig. 4 is a plan view of the piezoelectric film 14 viewed downward.

[0011] In this specification, directions are defined as follows. As shown in FIG. 1 , the direction in which the long sides of the touch panel 11 extend is defined as the left-right direction. The direction in which the short sides of the touch panel 11 extend is defined as the front-rear direction. The direction in which the touch panel 11 and the housing 2 are aligned is defined as the up-down direction. The left-right direction, front-rear direction, and up-down direction are perpendicular to each other. However, the left-right direction, front-rear direction, and up-down direction in this specification are defined for the convenience of explanation and may not coincide with the left-right direction, front-rear direction, and up-down direction when the sensor 1 or the electronic device 10 is in use. Furthermore, in each drawing, the left direction and the right direction may be interchanged, the front direction and the rear direction may be interchanged, and the up direction and the down direction may be interchanged.

[0012] The electronic device 10 is a portable electronic terminal such as a tablet computer, a smartphone, etc. As shown in FIG.

[0013] The housing 2 has a rectangular parallelepiped shape. However, the top surface of the housing 2 is open. The opening OP of the housing 2 has a rectangular shape when viewed from below. However, the opening OP of the housing 2 does not have to have a rectangular shape when viewed from below.

[0014] The sensor 1 is flexible. As shown in Fig. 2 , the sensor 1 includes a touch panel 11, a first adhesive member 12, a first electrode 13, a piezoelectric film 14, a second electrode 15, a second adhesive member 16, and a display 17. The touch panel 11, the first adhesive member 12, the first electrode 13, the piezoelectric film 14, the second electrode 15, the second adhesive member 16, and the display 17 are arranged in this order downward. As shown in Fig. 3 , the first adhesive member 12, the first electrode 13, the piezoelectric film 14, the second electrode 15, the second adhesive member 16, and the display 17 are each located within the housing 2 and are not in contact with the housing 2.

[0015] As shown in FIG. 1 , the touch panel 11 has a plate shape. The touch panel 11 has an upper main surface and a lower main surface arranged in this order along a downward direction. When viewed from below, the touch panel 11 has a rectangular shape with two long sides extending in the left-right direction and two short sides extending in the front-to-back direction. The vicinity of the outer edge of the lower main surface of the touch panel 11 is supported on the upper surface of the housing 2 by an adhesive such as double-sided tape, a thermosetting adhesive, a thermoplastic adhesive, or a UV (Ultra Violet) curing adhesive. A user performs a pressing operation on the upper main surface of the touch panel 11 using a pen, the user's own finger, or the like. In other words, the upper main surface of the touch panel 11 is an operation surface S1 that accepts the user's pressing operation. The outer edge of the touch panel 11 viewed from below coincides with the outer edge of the housing 2 viewed from below. In this embodiment, the touch panel 11 is a touch panel that detects the position where the user touches the touch panel 11. The structure of the touch panel is a common structure, so a description thereof will be omitted. The touch panel 11 does not have to have a rectangular shape when viewed from below. Furthermore, the outer edge of the touch panel 11 when viewed from below does not have to coincide with the outer edge of the housing 2 when viewed from below. The touch panel 11 is a specific example of the "first plate-like member" of the present invention. Therefore, the "first plate-like member" of the present invention is not limited to a touch panel, and may be a transparent plate, a protective sheet, or the like.

[0016] The first adhesive member 12 fixes the first electrode 13 to the touch panel 11. In this embodiment, the first adhesive member 12 has a sheet shape. When viewed from below, the first adhesive member 12 has a rectangular shape with two long sides extending in the left-right direction and two short sides extending in the front-rear direction. However, the outer edge of the first adhesive member 12 when viewed from below is surrounded by the outer edge of the opening OP of the housing 2 when viewed from below. The first adhesive member 12 is, for example, an adhesive such as OCA (Optical Clear Adhesive), double-sided tape, a thermosetting adhesive, a thermoplastic adhesive, or a UV (Ultra Violet) curing adhesive. Note that the first adhesive member 12 does not have to have a sheet shape. Furthermore, the first adhesive member 12 does not have to have a rectangular shape when viewed from below.

[0017] The piezoelectric film 14 has a sheet shape. The piezoelectric film 14 has an upper main surface S2 and a lower main surface S3 arranged in this order along a downward direction. When viewed from below, the piezoelectric film 14 has a rectangular shape with two long sides extending in the left-right direction and two short sides extending in the front-to-back direction. The outer edge of the piezoelectric film 14 when viewed from below coincides with the outer edge of the first adhesive member 12 when viewed from below. The piezoelectric film 14 generates an electric charge according to the amount of deformation of the piezoelectric film 14. Note that the piezoelectric film 14 does not have to have a rectangular shape when viewed from below. Furthermore, the outer edge of the piezoelectric film 14 when viewed from below does not have to coincide with the outer edge of the first adhesive member 12 when viewed from below. The piezoelectric film 14 will be described in more detail below.

[0018] The piezoelectric film 14 has a characteristic that the polarity of the electric charge generated when the piezoelectric film 14 is stretched in the left-right direction is opposite to the polarity of the electric charge generated when the piezoelectric film 14 is stretched in the front-back direction. The piezoelectric film 14 is a film formed from a chiral polymer. An example of the chiral polymer is polylactic acid (PLA), particularly poly-L-lactic acid (PLLA). PLLA, which is made of a chiral polymer, has a helical main chain structure. PLLA has piezoelectricity in which the molecules are oriented when uniaxially stretched. The piezoelectric film 14 has a piezoelectric constant of d14.

[0019] As shown in FIG. 4 , the uniaxial stretching direction (orientation direction) OD of the piezoelectric film 14 forms a 45-degree angle with respect to both the left-right direction and the front-back direction. This 45-degree angle includes angles within a range of approximately 45 degrees ±10 degrees. As a result, the piezoelectric film 14 generates electric charges when the piezoelectric film 14 is stretched in the left-right direction or compressed in the left-right direction. The polarity of the electric charges generated by the piezoelectric film 14 when stretched in the left-right direction is different from the polarity of the electric charges generated by the piezoelectric film 14 when stretched in the front-back direction. For example, when the piezoelectric film 14 is stretched in the left-right direction, the piezoelectric film 14 generates positive electric charges. For example, when the piezoelectric film 14 is stretched in the front-back direction, the piezoelectric film 14 generates negative electric charges. The magnitude of the electric charges generated by the piezoelectric film 14 depends on the amount of deformation of the piezoelectric film 14 due to the stretching or compression. More precisely, the magnitude of the electric charges generated by the piezoelectric film 14 is proportional to the differential value of the amount of deformation of the piezoelectric film 14 due to the stretching or compression. The uniaxial stretching direction (orientation direction) OD of the piezoelectric film 14 may form an angle of 0 degrees or 90 degrees with respect to the left-right direction. This 0 degrees or 90 degrees includes angles within the range of approximately 0 degrees ±10 degrees or 90 degrees ±10 degrees, respectively.

[0020] In this embodiment, the first electrode 13 is a ground electrode. The first electrode 13 is connected to a ground potential. As shown in FIG. 1 , the first electrode 13 has a sheet shape. The first electrode 13 has an upper main surface and a lower main surface arranged in this order along a downward direction. When viewed from below, the first electrode 13 has a rectangular shape with two long sides extending in the left-right direction and two short sides extending in the front-rear direction. The outer edge of the first electrode 13 when viewed from below coincides with the outer edge of the piezoelectric film 14 when viewed from below. The first electrode 13 is provided on the upper main surface S2 of the piezoelectric film 14. The upper main surface of the first electrode 13 is fixed to the lower main surface of the touch panel 11 by a first adhesive member 12. In this embodiment, the first adhesive member 12 covers the upper main surface of the first electrode 13. Note that the first electrode 13 does not have to have a sheet shape. The first electrode 13 does not have to have a rectangular shape when viewed from below. Furthermore, the outer edge of the first electrode 13 when viewed from below does not have to coincide with the outer edge of the piezoelectric film 14 when viewed from below. Furthermore, the first adhesive member 12 does not have to cover the upper main surface of the first electrode 13.

[0021] In this embodiment, the second electrode 15 is a signal electrode. The second electrode 15 outputs a signal corresponding to the charge generated by the piezoelectric film 14 as a detection signal of the sensor 1. The second electrode 15 has a sheet shape. The second electrode 15 has an upper main surface and a lower main surface arranged in this order along a downward direction. When viewed from below, the second electrode 15 has a rectangular shape with two long sides extending in the left-right direction and two short sides extending in the front-to-back direction. The outer edge of the second electrode 15 when viewed from below coincides with the outer edge of the piezoelectric film 14 when viewed from below. The second electrode 15 is provided on the lower main surface S3 of the piezoelectric film 14. The second electrode 15 does not have to have a sheet shape. The second electrode 15 does not have to have a rectangular shape when viewed from below. The outer edge of the second electrode 15 when viewed from below does not have to coincide with the outer edge of the piezoelectric film 14 when viewed from below. The first electrode 13 may be a signal electrode, and the second electrode 15 may be a ground electrode. A flexible substrate or a printed circuit board may be provided on the lower main surface of the second electrode 15. In this case, the second electrode 15 may be formed within the flexible substrate or the printed circuit board.

[0022] The second adhesive member 16 fixes the display 17 to the second electrode 15. In this embodiment, the second adhesive member 16 has a sheet shape. When viewed from below, the second adhesive member 16 has a rectangular shape with two long sides extending in the left-right direction and two short sides extending in the front-rear direction. In this embodiment, the second adhesive member 16 covers the lower main surface of the second electrode 15. The second adhesive member 16 is, for example, an adhesive such as OCA (Optical Clear Adhesive), double-sided tape, a thermosetting adhesive, a thermoplastic adhesive, or a UV (Ultra Violet) curing adhesive. Note that the second adhesive member 16 does not have to have a sheet shape. Furthermore, the second adhesive member 16 does not have to have a rectangular shape when viewed from below. Furthermore, the second adhesive member 16 does not have to cover the lower main surface of the second electrode 15.

[0023] The display 17 has a plate shape. The display 17 has an upper main surface and a lower main surface arranged in this order along a downward direction. When viewed downward, the display 17 has a rectangular shape with two long sides extending in the left-right direction and two short sides extending in the front-to-back direction. The outer edge of the display 17 when viewed downward coincides with the outer edge of the piezoelectric film 14 when viewed downward. Therefore, the outer edge of the display 17 when viewed downward is surrounded by the outer edge of the touch panel 11 when viewed downward. In other words, the entire display 17 overlaps the touch panel 11 when viewed downward. Furthermore, the upper main surface of the display 17 is fixed to the lower main surface of the second electrode 15 by the second adhesive member 16. In this embodiment, the display 17 is, for example, an organic EL display or a liquid crystal display. The structure of the display is a common structure, so description thereof will be omitted. Note that the display 17 does not have to have a rectangular shape when viewed downward. Furthermore, the outer edge of the display 17 when viewed downward does not have to coincide with the outer edge of the piezoelectric film 14 when viewed downward. Furthermore, the outer edge of the display 17 when viewed downward does not have to be surrounded by the outer edge of the touch panel 11 when viewed downward. The display 17 is a specific example of the "second plate-like member" of the present invention. Therefore, the "second plate-like member" of the present invention is not limited to a display.

[0024] The display 17 is not in contact with the housing 2. There is an air gap AG between the display 17 and the housing 2, as shown in FIG.

[0025] The elastic modulus E16 of the second adhesive member 16 is higher than the elastic modulus E12 of the first adhesive member 12. In other words, the second adhesive member 16 is harder than the first adhesive member 12.

[0026] In this embodiment, the elastic modulus E11 of the touch panel 11 is higher than the elastic modulus E17 of the display 17. That is, the touch panel 11 is harder than the display 17. Furthermore, the elastic modulus E17 of the display 17 is higher than the elastic modulus E16 of the second adhesive member 16. That is, the display 17 is harder than the second adhesive member 16. Therefore, in this embodiment, the following relationship holds: elastic modulus E11 of the touch panel 11 > elastic modulus E17 of the display 17 > elastic modulus E16 of the second adhesive member 16 > elastic modulus E12 of the first adhesive member 12. Note that the elastic modulus E11 of the touch panel 11 may be equal to or lower than the elastic modulus E17 of the display 17. Furthermore, the elastic modulus E17 of the display 17 may be equal to or lower than the elastic modulus E16 of the second adhesive member 16.

[0027] [Effect] The sensor 1 can suppress a decrease in detection sensitivity. As a comparative example, a sensor 50 according to the comparative example will be described with reference to the drawings. FIG. 5 is a diagram showing an example of the deformation amount of the sensor 50 according to the comparative example. FIG. 6 is a diagram showing an example of the deformation amount of the sensor 1. Note that the shading in FIGS. 5 and 6 indicates the amount of expansion or compression in the left-right direction of the upper main surface of the touch panel 11, the lower main surface of the touch panel 11, the upper main surface S2 of the piezoelectric film 14, the lower main surface S3 of the piezoelectric film 14, the upper main surface of the display 17, and the lower main surface of the display 17. The darker the shading, the more the target portion is expanded in the left-right direction. Furthermore, the lighter the shading, the more the target portion is compressed in the left-right direction.

[0028] In the sensor 50 according to the comparative example, the elastic modulus E12 of the first adhesive member 12 is higher than the elastic modulus E16 of the second adhesive member 16. The other configurations of the sensor 50 according to the comparative example are the same as those of the sensor 1 according to the embodiment. In this case, the sensor 50 according to the comparative example may exhibit reduced detection sensitivity when a user presses the operation surface S1 downward. More specifically, when a user presses the center of the upper main surface of the touch panel 11 downward, the touch panel 11 bends downward. Therefore, the vicinity of the center of the upper main surface of the touch panel 11 is compressed in the left-right direction, as shown in FIG. 5 . Meanwhile, the left and right ends of the upper main surface of the touch panel 11 are stretched in the left-right direction because the vicinity of the outer edge of the lower main surface of the touch panel 11 is supported by the housing 2 and the vicinity of the center of the upper main surface of the touch panel 11 is compressed in the left-right direction.

[0029] Furthermore, when a user presses the center of the upper main surface of touch panel 11 downward, touch panel 11 bends downward, and therefore the vicinity of the center of the lower main surface of touch panel 11 is stretched in the left-right direction. On the other hand, the left and right ends of the lower main surface of touch panel 11 are compressed in the left-right direction because the vicinity of the outer edge of the lower main surface of touch panel 11 is supported by housing 2, and the vicinity of the center of the lower main surface of touch panel 11 is stretched in the left-right direction.

[0030] Similarly, when the user presses the center of the upper main surface of the touch panel 11 downward, the display 17 bends downward. As a result, the vicinity of the center of the upper main surface of the display 17 is compressed in the left-right direction. Meanwhile, the left and right ends of the upper main surface of the display 17 are expanded in the left-right direction due to the repulsion caused by the compression in the left-right direction of the vicinity of the center of the upper main surface of the display 17.

[0031] Furthermore, when the user presses the center of the upper main surface of the touch panel 11 downward, the display 17 bends downward, and the vicinity of the center of the lower main surface of the display 17 expands in the left-right direction. On the other hand, the left and right ends of the lower main surface of the display 17 are compressed in the left-right direction due to the repulsion caused by the expansion in the left-right direction of the vicinity of the center of the lower main surface of the display 17.

[0032] In the sensor 50 according to the comparative example, the elastic modulus E12 of the first adhesive member 12 is higher than the elastic modulus E16 of the second adhesive member 16. That is, the first adhesive member 12 is harder than the second adhesive member 16. In this case, when a user presses downward on the center of the upper main surface of the touch panel 11, the piezoelectric film 14 is more likely to deform in response to the downward bending of the touch panel 11 than to the downward bending of the display 17. That is, in the sensor 50 according to the comparative example, the piezoelectric film 14 mainly detects deformation of the touch panel 11.

[0033] In this case, however, a neutral plane of stress is generated in the piezoelectric film 14, and as shown in Fig. 5, the upper main surface S2 and the lower main surface S3 of the piezoelectric film 14 may not deform in the left-right direction. That is, the piezoelectric film 14 may not be able to detect deformation of the touch panel 11, which may reduce the detection sensitivity of the sensor 1. If the sensor is formed so that the elastic modulus E12 of the first adhesive member 12 is higher than the elastic modulus E16 of the second adhesive member 16, as in the sensor 50 according to the comparative example, the detection sensitivity of the sensor may reduce.

[0034] On the other hand, in the sensor 1 according to this embodiment, the elastic modulus E16 of the second adhesive member 16 is higher than the elastic modulus E12 of the first adhesive member 12. This makes it easier for the piezoelectric film 14 to deform in response to downward bending of the display 17 than to downward bending of the touch panel 11. That is, the piezoelectric film 14 primarily detects deformation of the display 17. Comparing FIGS. 5 and 6 , the amounts of horizontal deformation of the upper and lower main surfaces of the touch panel 11, the upper and lower main surfaces of the display 17, and the lower main surface of the display 17 are substantially the same in the sensor 50 according to the comparative example and the sensor 1. However, as shown in FIG. 6 , in the sensor 1, the piezoelectric film 14 deforms in response to downward bending of the display 17, thereby preventing a neutral plane of stress from being generated in the piezoelectric film 14, and allowing the upper and lower main surfaces S2, S3 of the piezoelectric film 14 to deform in the horizontal direction. This allows the sensor 1 to accurately detect deformation of the upper main surface of the display 17. That is, the sensor 1 can generate an appropriate deformation in the piezoelectric film 14 in response to a pressing operation on the operation surface S1, and therefore the sensor 1 can suppress a decrease in detection sensitivity.

[0035] Furthermore, the sensor 1 can improve detection accuracy. More specifically, the elastic modulus E11 of the touch panel 11 is higher than the elastic modulus E17 of the display 17. That is, the touch panel 11 is harder than the first adhesive member 12. As a result, because the touch panel 11 is hard, it is possible to suppress minute vibrations of the operation surface S1 when a user presses the operation surface S1, thereby reducing the effect of minute vibrations of the operation surface S1 on deformation of the piezoelectric film 14. Furthermore, because the first adhesive member 12 is soft, the piezoelectric film 14 is more likely to deform in response to downward bending of the display 17, making it easier to accurately detect deformation of the display 17. Therefore, the sensor 1 can improve detection accuracy.

[0036] Furthermore, the sensor 1 can improve detection sensitivity. More specifically, the operation surface S1 accepts a pressing operation by the user. Therefore, the display 17 is easily deformed by a pressing operation by the user in a range where it overlaps with the touch panel 11 when viewed downward. Therefore, the outer edge of the display 17 when viewed downward is surrounded by the outer edge of the touch panel 11 when viewed downward. In other words, the entire display 17 overlaps with the touch panel 11 when viewed downward. Therefore, the entire display 17 is easily deformed by a pressing operation by the user. As a result, the sensor 1 can improve detection sensitivity.

[0037] Furthermore, the sensor 1 can improve detection sensitivity. More specifically, a gap AG exists between the display 17 and the housing 2. Therefore, the display 17 can bend downward when pressed by a user without being hindered from deforming. In other words, the display 17 is easily deformed when pressed by a user. Therefore, the sensor 1 can improve detection sensitivity.

[0038] [First Modification] A sensor 1a according to a first modification of the present invention will be described below. Note that with regard to the sensor 1a according to the first modification, only the differences from the sensor 1a according to the first embodiment will be described, and the rest will be omitted.

[0039] The sensor 1a differs from the sensor 1 in that the display 17 is a conductive plate-like member that is electrically conductive and connected to the ground potential.

[0040] The sensor 1a described above also achieves the same effects as the sensor 1. Furthermore, the sensor 1a can further improve detection accuracy. More specifically, the piezoelectric film 14 is sandwiched between the first electrode 13, which is a ground electrode connected to the ground potential, and a conductive plate-like member also connected to the ground potential. This prevents noise from entering the piezoelectric film 14. Therefore, the sensor 1a can further improve detection accuracy.

[0041] The sensor according to the present invention is not limited to the sensor 1 and the sensor 1a, and can be modified within the scope of the gist thereof. In addition, the structures of the sensor 1 and the sensor 1a may be combined arbitrarily.

[0042] The electronic device according to the present invention is not limited to the electronic device 10, and can be modified within the scope of the gist thereof. Furthermore, the electronic device according to the present invention may include a sensor 1a instead of the sensor 1.

[0043] As shown in FIG. 7, the sensor 1 or 1a may further include support members 3a and 3b. In this case, the support members 3a and 3b support the left and right ends of the display 17, respectively. In this case, the same effects as those of the sensor 1 or 1a are achieved. The sensor 1 or 1a may include a support member 3 that integrates the support members 3a and 3b, instead of the support members 3a and 3b. In this case, the support member 3 has a ring shape and supports the vicinity of the outer edge of the lower main surface of the display 17. In this case, the same effects as those of the sensor 1 or 1a are achieved.

[0044] The present invention has the following configuration.

[0045] (1) A flexible sensor comprising: a first plate-shaped member; a first adhesive member; a piezoelectric film having an upper main surface and a lower main surface; a first electrode provided on the upper main surface; a second electrode provided on the lower main surface; a second adhesive member; and a second plate-shaped member, wherein the first plate-shaped member has an operation surface that accepts a pressing operation; the first adhesive member fixes the first electrode to the first plate-shaped member; and the second adhesive member fixes the second plate-shaped member to the second electrode; the first plate-shaped member, the first adhesive member, the first electrode, the piezoelectric film, the second electrode, the second adhesive member, and the second plate-shaped member are arranged in this order downward; and the elastic modulus of the second adhesive member is higher than the elastic modulus of the first adhesive member.

[0046] (2) The sensor according to (1), wherein the first plate-shaped member has a higher elastic modulus than the second plate-shaped member.

[0047] (3) The sensor according to (2), wherein the second plate-shaped member has a higher elastic modulus than the second adhesive member.

[0048] (4) The sensor according to any one of (1) to (3), wherein an outer edge of the second plate-shaped member when viewed in the downward direction is surrounded by an outer edge of the first plate-shaped member when viewed in the downward direction.

[0049] (5) The sensor according to any one of (1) to (4), wherein the first plate-shaped member is a touch panel, and the second plate-shaped member is a display.

[0050] (6) The sensor according to any one of (1) to (5), wherein the first electrode is a ground electrode connected to a ground potential, the second electrode is a signal electrode that outputs a signal according to an electric charge generated by the piezoelectric film, and the second plate-like member is conductive and connected to the ground potential.

[0051] (7) An electronic device comprising: the sensor according to any one of (1) to (6); and a housing that supports the first plate-shaped member.

[0052] (8) The electronic device according to (7), wherein the piezoelectric film is located inside the housing.

[0053] (9) The electronic device according to (7) or (8), wherein a gap exists between the second plate-shaped member and the housing.

[0054] (10) The electronic device according to any one of (7) to (9), further comprising a support member that supports the second plate-shaped member.

[0055] 1, 1a: Sensor 2: Housing 3, 3a, 3b: Support member 10: Electronic device 11: Touch panel 12: First adhesive member 13: First electrode 14: Piezoelectric film 15: Second electrode 16: Second adhesive member 17: Display AG: Gap E11, E12, E16, E17: Elastic modulus OP: Opening S1: Operation surface S2: Upper main surface S3: Lower main surface

Claims

1. A flexible sensor comprising: a first plate-shaped member; a first adhesive member; a piezoelectric film having an upper main surface and a lower main surface; a first electrode provided on the upper main surface; a second electrode provided on the lower main surface; a second adhesive member; and a second plate-shaped member, wherein the first plate-shaped member has an operation surface that accepts a pressing operation, the first adhesive member fixes the first electrode to the first plate-shaped member, and the second adhesive member fixes the second plate-shaped member to the second electrode, the first plate-shaped member, the first adhesive member, the first electrode, the piezoelectric film, the second electrode, the second adhesive member, and the second plate-shaped member are arranged in this order downward, and the elastic modulus of the second adhesive member is higher than the elastic modulus of the first adhesive member.

2. The sensor according to claim 1, wherein the elastic modulus of the first plate member is higher than the elastic modulus of the second plate member.

3. The sensor according to claim 2, wherein the elastic modulus of the second plate-like member is higher than the elastic modulus of the second adhesive member.

4. A sensor as described in any one of claims 1 to 3, wherein an outer edge of the second plate-like member when viewed in the downward direction is surrounded by an outer edge of the first plate-like member when viewed in the downward direction.

5. A sensor according to any one of claims 1 to 4, wherein the first plate-like member is a touch panel, and the second plate-like member is a display.

6. A sensor as described in any one of claims 1 to 5, wherein the first electrode is a ground electrode connected to a ground potential, the second electrode is a signal electrode that outputs a signal corresponding to an electric charge generated by the piezoelectric film, and the second plate-like member is conductive and connected to the ground potential.

7. An electronic device comprising: a sensor according to any one of claims 1 to 6; and a housing supporting the first plate-like member.

8. The electronic device according to claim 7, wherein the piezoelectric film is located within the housing.

9. The electronic device according to claim 7 or 8, wherein a gap exists between the second plate-like member and the housing.

10. The electronic device according to any one of claims 7 to 9, further comprising a support member for supporting the second plate-like member.

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