JP5994949B2 - Operation input device - Google Patents

Description

  The present invention relates to an operation input device that detects that an operation surface is pushed.

  An operation input device having an operation surface such as a touch panel may detect pressing of the operation surface and may be provided with a piezoelectric film that can detect pressing of the operation surface. (For example, refer to Patent Document 1).

  The operation input device described in Patent Literature 1 includes a rectangular flat plate-shaped touch panel and a strip-shaped piezoelectric film, and a piezoelectric film is attached to the back surface of the touch panel along the short side of the touch panel. When the touch panel is pressed and distorted by this operation input device, the piezoelectric film attached to the back surface of the touch panel is also distorted. Thereby, the electric potential difference according to the magnitude | size of distortion is generated in both the main surfaces of a piezoelectric film, and the press with respect to a touch panel can be detected by detecting this electric potential difference.

JP 2012-203552 A

  In the operation input device described in Patent Document 1, as described above, the piezoelectric film is attached to the back surface of the touch panel. However, in the operation input device, the piezoelectric film is attached to the back surface of the touch panel due to a design problem. May not be possible. In this case, if the piezoelectric film is provided without being attached to the touch panel, the touch of the touch panel cannot be transmitted well to the piezoelectric film, and the touch of the touch panel may not be accurately detected by the piezoelectric film.

  Accordingly, an object of the present invention is to provide an operation input device that can reliably detect the pressing operation of the operation surface with the piezoelectric film even when the piezoelectric film is not attached to the back surface side of the operation surface.

  The operation input device of the present invention includes an operation plate, a frame, a detection plate, and a piezoelectric film. The operation plate receives a pressing operation. The frame holds the operation plate. When the detection plate is not assembled to the frame, the detection plate has a convex shape that warps toward the operation plate. The detection plate is assembled to the frame so that the convex warp is pressed against the operation plate. The piezoelectric film is attached to the detection plate.

  In a structure in which a detection plate and a piezoelectric film are bonded together (hereinafter referred to as a bonded body), deformation may occur due to a difference in linear expansion coefficient between the detection plate and the piezoelectric film. If the linear expansion coefficient difference is large, the patch may be deformed so as to be separated from the operation plate depending on the temperature, and the pressing of the operation plate may not be transmitted well to the patch. However, in the above configuration, since the detection plate is provided so as to press the convex warp against the operation plate, even if the patch is deformed due to a difference in linear expansion coefficient, the patch is deformed so as to be separated from the operation plate. This makes it difficult to transmit the pressure on the operation plate to the detection plate.

  It is preferable that the above-described operation input device further includes a pusher that is provided between the detection plate and the operation plate and that pushes the detection plate when the operation plate receives a pressing operation. In this configuration, even if the operation plate and the detection plate are arranged far apart, the pressure on the operation plate can be transmitted to the detection plate via the pusher.

  In the operation input device described above, the piezoelectric film may be provided on the operation plate side of the detection plate. Since the piezoelectric film generally has a larger linear expansion coefficient than the metal material used as the detection plate, the adhesive body between the piezoelectric film and the detection plate is affected by the difference in linear expansion coefficient. There is a tendency to bend in the opposite direction. Therefore, if the piezoelectric film is provided on the operation plate side of the detection plate, the patch is easily separated from the operation plate. However, in the configuration in which the convex warp of the detection plate is pressed against the operation plate as described above, the adhesive body is difficult to be separated from the operation plate. Therefore, even if the piezoelectric film is provided on the operation plate side of the detection plate. The distortion due to the pressing of the operation plate can be reliably transmitted to the detection plate.

  In the operation input device described above, the piezoelectric film is preferably made of a chiral polymer. In the operation input device described above, the chiral polymer is preferably L-type polylactic acid.

  For example, when PVDF (polyvinylidene fluoride) is used for the piezoelectric film, a change in operating temperature may affect the piezoelectric characteristics of the piezoelectric film. However, in this configuration, since the L-type polylactic acid, which is a chiral polymer, does not have pyroelectricity, it is possible to accurately detect pressing with a piezoelectric film.

  According to the present invention, the pressure on the operation plate can be reliably transmitted to the detection plate, and the pressure on the operation plate can be reliably detected by the piezoelectric film attached to the detection plate.

It is a top view of the operation input device concerning a 1st embodiment. It is side surface sectional drawing of the operation input apparatus which concerns on 1st Embodiment. It is side surface sectional drawing which expands and shows the periphery of the piezoelectric film in the operation input apparatus which concerns on 1st Embodiment. It is side surface sectional drawing explaining the non-assembly | attachment state of the sticking body in the operation input apparatus which concerns on 1st Embodiment. It is side surface sectional drawing explaining the press detection in the operation input apparatus which concerns on 1st Embodiment. It is side surface sectional drawing of the operation input apparatus which concerns on 2nd Embodiment. It is side surface sectional drawing of the operation input apparatus which concerns on 3rd Embodiment. It is side surface sectional drawing of the operation input apparatus which concerns on 4th Embodiment.

<< First Embodiment >>
The operation input device 10 according to the first embodiment of the present invention will be described. The operation input device 10 is used as, for example, a multifunction mobile terminal. FIG. 1 is a plan view of the operation input device 10. FIG. 2 is a side sectional view of the operation input device 10. FIG. 2 shows a side cross-section at the position indicated by the alternate long and short dash line AA in FIG.

  The operation input device 10 includes a frame 11, an operation plate 12, spacers 14A and 14B, a detection plate 15, a sensor unit 16, a pusher 18, and a circuit unit (not shown).

  The frame 11 has a thin box shape, and includes a frame-shaped side surface and a rectangular bottom surface, and has a rectangular opening on the top surface side. The operation plate 12 has a rectangular flat plate shape and is joined to the frame body 11 so as to close the opening of the frame body 11. For example, the operation panel 12 is configured as transparent glass with a display panel and a touch panel attached to the back surface. Hereinafter, the longitudinal direction of the main surface of the operation plate 12 is referred to as the X direction, the short direction of the main surface of the operation plate 12 is referred to as the Y direction, and the direction perpendicular to the main surface of the operation plate 12 is referred to as the Z direction. There is.

  The spacer 14 </ b> A is disposed in the vicinity of the first side surface parallel to the X direction among the side surfaces of the frame body 11. The spacer 14 </ b> B is disposed in the vicinity of the second side surface (side surface facing the first side surface) of the frame body 11. The spacers 14 </ b> A and 14 </ b> B each have a columnar shape extending in the Z direction, and are disposed at a substantially central portion in the X direction of the frame body 11.

  The detection plate 15 has a strip shape made of SUS (stainless steel) and is arranged in an internal space surrounded by the frame body 11 and the operation plate 12 so that the main surface thereof is parallel to the main surface of the operation plate 12. Yes. The detection plate 15 is disposed at a substantially central portion in the X direction of the frame body 11. The longitudinal direction of the detection plate 15 is parallel to the Y direction. Both ends in the longitudinal direction of the detection plate 15 are supported by spacers 14A and 14B, respectively. Spaces are formed between the detection plate 15 and the operation plate 12 and between the detection plate 15 and the bottom surface of the frame body 11.

  The sensor unit 16 has a strip shape, and is affixed to the main surface of the detection plate 15 on the operation plate 12 side so that the longitudinal direction thereof is the Y direction. Hereinafter, a structure in which the sensor unit 16 and the detection plate 15 are bonded together is referred to as a patch 17. The circuit unit is disposed in the internal space between the frame body 11 and the operation plate 12 and is electrically connected to the sensor unit 16.

  The pusher 18 is disposed between the operation plate 12 and the sticking body 17 and is in contact with the operation plate 12 and the sticking body 17. The pusher 18 has a columnar shape extending in the Z direction. The pusher 18 is shorter than the patch 17 in the Y direction, and is disposed at a substantially central portion of the patch 17 in the Y direction. The pusher 18 transmits the pressing force of the operation plate 12 to the sticking body 17. By providing the pusher 18, the operation plate 12 and the sticking body 17 can be arranged largely apart from each other. For this reason, other parts etc. can be arranged between operation board 12 and pasting object 17, and the design freedom of operation input device 10 increases.

  FIG. 3 is an enlarged side cross-sectional view of the patch 17 including the sensor unit 16 and the detection plate 15. The sensor unit 16 includes a piezoelectric film 31, adhesive layers 32 and 33, flat plate electrodes 34 and 35, and base material layers 36 and 37. A plate electrode 34 is attached to one main surface of the piezoelectric film 31 with an adhesive layer 32. A flat plate electrode 35 is attached to the other main surface of the piezoelectric film 31 with an adhesive layer 33. The plate electrodes 34 and 35 are electrically connected to a circuit unit (not shown). A base material layer 36 is disposed on the main surface of the plate electrode 34 opposite to the piezoelectric film 31 side. A base material layer 37 is disposed on the main surface of the plate electrode 35 opposite to the piezoelectric film 31 side. The sensor unit 16 is affixed to the main surface of the detection plate 15 with an adhesive layer 38 so that the base material layer 36 side faces the detection plate 15.

  The piezoelectric film 31 is made of PLLA (L-type polylactic acid). PLLA is a chiral polymer, and the main chain has a helical structure. PLLA is uniaxially stretched and has piezoelectricity when the molecules are oriented. The piezoelectric constant of uniaxially stretched PLLA belongs to a very high class among polymers. In addition, since the chiral polymer is a polymer and has flexibility, it is not damaged by a large displacement unlike piezoelectric ceramics. Therefore, the piezoelectric film 31 mainly composed of a chiral polymer is not damaged even if the displacement amount is large, and the displacement amount can be reliably detected.

  In addition, PLLA generates piezoelectricity by molecular orientation treatment such as stretching, and does not need to be polled like other polymers such as PVDF or piezoelectric ceramics. That is, the piezoelectricity of PLLA that does not belong to ferroelectrics is not expressed by the polarization of ions like ferroelectrics such as PVDF and PZT, but is derived from a helical structure that is a characteristic structure of molecules. is there. For this reason, the pyroelectricity generated in other ferroelectric piezoelectric materials does not occur in PLLA. Further, PVDF or the like shows a change in piezoelectric constant over time, and in some cases, the piezoelectric constant may be significantly reduced, but the piezoelectric constant of PLLA is extremely stable over time.

Stretching direction of PLLA to take three axes, taking uniaxially and biaxially in a direction perpendicular to the three axial directions, the PLLA there is the piezoelectric constant of d ₁₄ (piezoelectric constant shear). The striped piezoelectric film 31 is cut so that the uniaxial direction is the thickness direction and the direction that forms an angle of 45 ° with respect to the triaxial direction (stretching direction) is the longitudinal direction. Thereby, when the piezoelectric film 31 expands and contracts in the longitudinal direction, the piezoelectric film 31 is polarized in the thickness direction.

  The material of the adhesive layers 32, 33, 38 is composed of an adhesive or an adhesive. The difference between a pressure-sensitive adhesive and an adhesive is that the pressure-sensitive adhesive always keeps a wet state stably, whereas the pressure-sensitive adhesive changes from a liquid to a solid when bonded. If an adhesive is used for the material of the adhesive layers 32, 33, and 38, the thickness of the adhesive can be easily controlled compared to the adhesive. On the other hand, if an adhesive is used for the material of the adhesive layers 32, 33, 38, it is harder than an adhesive, so that deformation due to pressing is difficult to alleviate, and better detection sensitivity is easily obtained. The plate electrodes 34 and 35 are made of a metal film such as a copper foil. The material of the base material layers 36 and 37 is a resin such as polyimide.

  FIG. 4 is a side sectional view of the patch 17 in a state where the patch 17 is not assembled to the operation input device 10 (non-assembled state).

  The patch 17 is molded or plastically processed so that the shape when not attached to the operation input device 10 is curved and warped convexly toward the sensor unit 16 side, that is, the pusher 18 and the operation plate 12 side. It is a thing.

  As shown in FIG. 2, the sticker 17 has both ends in the Y direction fixed by spacers 14A and 14B, and a portion warped in the vicinity of the center is pressed against the above-described pusher 18, so that the frame 11 And the operation space of the operation plate 12. The assembled patch 17 is elastically deformed so that the portion warped in a convex shape becomes flat, and an elastic force is applied to the pusher 18 against the operation plate 12. Specifically, the fixed positions of both ends of the sticking body 17 in the Z direction and the contact positions of the sticking body 17 and the pusher in the Z direction are set so as to substantially match.

  For this reason, in the state where the patch 17 is assembled, even if the operation plate 12 is pressed or the operation plate 12 is not pressed, the patch 17 always hits the pusher 18 and sticks. The body 17 and the pusher 18 come into reliable contact. Therefore, the pressure applied to the operation plate 12 is reliably transmitted to the detection plate 15 via the pusher 18, and the pressure operation of the operation plate 12 is detected by detecting the distortion of the detection plate 15 by the sensor unit 16. be able to.

  Note that a resin such as a chiral polymer (polymer) that constitutes the piezoelectric film 31 of the sensor unit 16 or a polyimide that constitutes the base material layers 36 and 37 generally has a larger linear expansion coefficient than SUS that constitutes the detection plate 15. In a low temperature environment, the sensor unit 16 contracts more than the detection plate 15, and thermal deformation occurs such that the patch 17 is bent in a concave direction on the operation plate 12 side. This thermal deformation causes the patch 17 to warp in a direction opposite to the warp in the non-assembled state. Therefore, the warp amount of the detection plate 15 in the non-assembled state is in the entire operating temperature range of the operation input device 10. Even if there is thermal deformation, it is preferable to set the patch 17 so as to ensure a warp that protrudes toward the sensor unit 16 side.

  FIG. 5 is a side cross-sectional view for explaining detection of pressing (pushing) of the operation plate 12 in the operation input device 10. When the operation plate 12 is pushed by a pressing operation, the patch 17 is pushed through the pusher 18. Since the patch 17 has its ends fixed by the spacers 14A and 14B and held in a substantially flat shape, the patch 17 is bent so as to be convex in the direction of being pushed into the pusher 18. Thereby, the patch 17 is distorted so that the main surface on the operation plate 12 side of both the principal surfaces of the patch 17 contracts in the longitudinal direction (Y direction). For this reason, the sensor part 16 affixed to the main surface by the side of the operation board 12 of the sticking body 17 also shrinks in a longitudinal direction. Then, since the piezoelectric film 31 (see FIG. 3) constituting the sensor unit 16 is also contracted in the longitudinal direction, the piezoelectric film 31 is polarized in the thickness direction due to the piezoelectric effect, and a potential difference is generated between both main surfaces of the piezoelectric film 31. Due to this potential difference, electric charges are induced in the plate electrodes 34 and 35 facing both main surfaces of the piezoelectric film 31. The circuit unit converts the flow (current) of this charge into a voltage, and detects the pressing of the operation plate 12 as a voltage. Since the pressure applied to the operation plate 12 is reliably transmitted to the sticking body 17 via the pusher 18, even if the sensor unit 16 is not attached to the operation plate 12, the pressure applied to the operation plate 12 is ensured by the sensor unit 16. Can be detected.

<< Second Embodiment >>
Next, the operation input device 40 according to the second embodiment of the present invention will be described. The configuration of the operation input device 40 according to the second embodiment is almost the same as that of the first embodiment, but is different from the first embodiment in that it further includes a cushion (elastic body). .

  FIG. 6 is a side sectional view of the operation input device 40 according to the second embodiment. The operation input device 40 further includes a cushion (elastic body) 42 in addition to the frame body 11, the operation plate 12, the spacers 14 </ b> A and 14 </ b> B, the pasting body 17, the pusher 18, and a circuit unit (not shown). ing. The cushion 42 is disposed between the frame body 11 and the patch body 17 so as to face the pusher 18, and is in contact with the frame body 11 and the detection plate 15. The cushion 42 is disposed substantially at the center of the detection plate 15 in the Y direction, and has substantially the same shape and size as the pusher 18 in plan view (as viewed from the Z direction).

  The cushion 42 is provided to urge the central portion of the sticking body 17 in the Y direction toward the sensor unit 16, that is, the pusher 18 and the operation plate 12. In the configuration in which the cushion 42 is provided in this manner, it is possible to make it difficult for the patch 17 to be separated from the operation plate 12 and the pusher 18 in the same manner as the configuration in which the patch 17 is convexly bent toward the operation plate 12 in a non-assembled state. it can. Therefore, the combination of the configuration in which the patch 17 is convexly warped toward the operation plate 12 in a non-assembled state and the configuration in which the cushion 42 is provided can further reliably transmit the pressure on the operation plate 12 to the detection plate 15. Can do.

<< Third Embodiment >>
Next, an operation input device 50 according to a third embodiment of the present invention will be described. The configuration of the operation input device 50 according to the third embodiment is almost the same as that of the first embodiment, but is different from the first embodiment in that the pusher is omitted.

  FIG. 7 is a side sectional view of the operation input device 50 according to the third embodiment. The operation input device 50 includes the frame body 11, the operation plate 12, the spacers 14 </ b> A and 14 </ b> B, the pasting body 17, and a circuit unit (not shown), and a pusher is omitted.

  The patch 17 has not only the original shape when not attached to the operation input device 10 but also the shape when attached to the operation input device 10, that is, the pusher 18 and the operation plate. Curved convexly on the 12 side and warped.

  Here, the sticking body 17 in the state where it is assembled to the operation input device 10 is fixed with the spacers 14A and 14B at both ends in the Y direction, and directly pressed against the convex portion near the center against the operation plate 12. The inner space of the frame 11 and the operation plate 12 is assembled. The patch 17 is elastically deformed so that a portion warped in a convex state in the assembled state becomes flatter than the non-assembled state (so as to be pushed back), and an elastic force that pushes the operation plate 12 is applied.

  For this reason, in the state where the patch 17 is assembled, the patch 17 always touches the operation plate 12 even if the operation plate 12 is pressed or the operation plate 12 is not pressed. Thus, the patch 17 and the operation plate 12 come into reliable contact. Therefore, the pressure applied to the operation plate 12 is reliably transmitted to the detection plate 15, and the pressure on the operation plate 12 can be detected by detecting the distortion of the detection plate 15 with the sensor unit 16.

<< Fourth Embodiment >>
Next, an operation input device 60 according to a fourth embodiment of the present invention will be described. The configuration of the operation input device 60 according to the fourth embodiment is almost the same as that of the third embodiment, but the shape of the patch is different from that of the third embodiment.

  FIG. 8 is a side sectional view of the operation input device 60 according to the fourth embodiment. The operation input device 60 includes the frame body 11, the operation plate 12, the spacers 14 </ b> A and 14 </ b> B, and a circuit unit (not shown), and includes an adhesive body 67 instead of the adhesive body 17.

  The patch 67 is molded or plastically processed so that the original shape in a state where it is not assembled to the operation input device 60 is warped with the central portion bent toward the sensor portion 66 side, that is, the operation plate 12 side. It has been done. Thus, the patch 67 is not limited to a curved and warped shape, and may be a shape that bends and warps.

  Although the present invention can be implemented as described in the above embodiments, the presence or absence of a cushion and the presence or absence of a pusher shown in each embodiment may be combined appropriately.

  Moreover, a sticking body can be made into an appropriate arrangement | positioning and shape by the balance of the mounting position with the other internal components incorporated in the inside of a frame. For example, in the above-described embodiment, the example in which the patch is arranged in parallel to the short side of the frame body in plan view is shown, but the patch body is arranged in parallel to the long side of the frame body in plan view. It may be arranged so as to be slanted with respect to the long side and the short side of the frame. In the above-described embodiment, an example in which one patch is arranged in the center in the X-axis direction inside the frame has been shown. However, for example, a plurality of patches may be arranged in the X-axis direction. In addition, the patch may be configured to be wider in the X-axis direction. If it does in this way, it can control that the detection sensitivity of press varies according to a press position.

DESCRIPTION OF SYMBOLS 10, 40, 50, 60 ... Operation input device 11 ... Frame body 12 ... Operation board 14A, 14B ... Spacer 15, 65 ... Detection board 16, 66 ... Sensor part 17, 67 ... Paste 18 ... Pusher 31 ... Piezoelectric film 32, 33, 38 ... adhesive layers 34, 35 ... flat plate electrodes 36, 37 ... base material layer 42 ... cushion

Claims (5)

An operation panel for receiving a pressing operation;
A frame for holding the operation plate;
A detection plate that is assembled to the frame so that the convex is warped toward the operation plate when not assembled to the frame, and the convex warpage is pressed against the operation plate; ,
A piezoelectric film that is affixed to the operation plate side of the detection plate and has a larger linear expansion coefficient than the detection plate ,
An operation input device comprising:   The operation input device according to claim 1, further comprising a pusher that is provided between the detection plate and the operation plate and pushes the detection plate when the operation plate receives a pressing operation.   The operation input device according to claim 1, wherein the piezoelectric film is provided on the operation plate side of the detection plate.   The operation input device according to claim 1, wherein the piezoelectric film is made of a chiral polymer.   The operation input device according to claim 4, wherein the chiral polymer is L-type polylactic acid.

Images