JPWO2017061350A1 - Vibration device and tactile presentation device - Google Patents

Abstract

The vibration device (20) is connected to the vibration plate (21) at a plurality of locations aligned in the first surface direction and a piezoelectric film (22) that vibrates the vibration plate (21) by expanding and contracting. ) And a spacer (70) that supports the diaphragm (21) so as to face the mounting surface A. The spacer (70) includes a base surface B that can contact the mounting surface A, a first protrusion (74) that can contact the diaphragm (21), and a first protrusion (74) in the second surface direction. 2nd protrusion (75) which can contact the center side of a diaphragm (21) rather than. When the spacer (70) is not deformed, the height of the first protrusion (74) from the base surface (B) is larger than the height of the second protrusion (75) from the base surface B.

Description

  The present invention relates to a vibration device that vibrates a diaphragm using a stretchable film, and a tactile sense presentation device that provides tactile feedback to a user who performs a touch operation.

  Conventionally, vibration devices that vibrate a diaphragm by driving a film such as a piezoelectric film have been widely used. The vibration device is used for, for example, a planar speaker or a haptic device (tactile sense presentation device). For example, Patent Document 1 discloses a vibration device configured as a flat speaker.

  FIG. 11 is a side view of the vibration device 101 according to Patent Document 1. FIG. The vibration device 101 includes an exciter film 102, a vibration plate 103, frame members 104 and 105, and a piezoelectric film 106. The piezoelectric film 106 is affixed to the surface of the exciter film 102 that faces the diaphragm 103. The frame members 104 and 105 are provided between both ends of the exciter film 102 and both ends of the diaphragm 103. The diaphragm 103 is bent so that the central portion thereof is separated from the piezoelectric film 106 and the exciter film 102, and tension is applied to the piezoelectric film 106 and the exciter film 102 via the frame members 104 and 105.

  In the vibration device 101, when a driving voltage is applied to the piezoelectric film 106, the piezoelectric film 106 expands and contracts in the surface direction. Then, as the piezoelectric film 106 expands and contracts, the tension of the exciter film 102 varies and the diaphragm 103 vibrates.

International Publication No. 2012/157691 Pamphlet

  The vibration device 101 illustrated in FIG. 11 can also be configured as a haptic device (tactile sense presentation device). For example, when the vibration device 101 is a tactile presentation device, a touch sensor (not shown) for detecting a touch operation by a user is provided on the vibration plate 103, and when the touch operation is detected by the touch sensor, the piezoelectric film 106 is Apply drive voltage. By configuring the vibration device 101 in this manner, the vibration of the diaphragm 103 can be given to the user as tactile feedback.

  However, when the user strongly presses the diaphragm 103, the diaphragm 103 may be pushed in and the gap between the diaphragm 103 and the film may be crushed. Then, the diaphragm 103 becomes difficult to bend, and it becomes difficult to give tactile feedback to the user who presses the diaphragm 103.

  In addition, when a thin member is used for the diaphragm 103, the diaphragm 103 may have a warp that bends in the thickness direction due to distortion or the like generated during manufacturing. For this reason, vibration devices may cause variations in vibration characteristics and deterioration of vibration characteristics due to the warpage of the diaphragm, and it is necessary to select diaphragms with less warpage when manufacturing the vibration device. It was.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a vibration device and a tactile presentation device capable of stably obtaining good vibration characteristics even when the vibration plate is warped and reliably providing tactile feedback to a user pressing the vibration plate. Is to provide.

  The present invention relates to a diaphragm, a film that is connected to the diaphragm at a plurality of positions separated in the first surface direction of the diaphragm, and vibrates the diaphragm by expanding and contracting, the diaphragm and the film And a spacer that supports the diaphragm and the film so as to face a mounting surface through a gap portion between and a mounting surface. The spacer includes a base surface that can contact the mounting surface, a first location that can contact the diaphragm, and a second surface direction that intersects the first surface direction of the diaphragm. And a second location that can contact the center side of the diaphragm rather than the first location. In addition, the height of the first location from the base surface in a state where the spacer is not deformed is greater than the height of the second location from the base surface.

  In the configuration of the vibration device according to the present invention, the gap portion between the diaphragm and the film can be prevented from being crushed by the spacer. Thereby, even in a state where the diaphragm is strongly pressed, the diaphragm can be reliably vibrated by expansion and contraction of the film.

  Further, if the spacer is not provided, if the diaphragm is warped in the convex direction toward the film along the second surface direction (hereinafter, such a state of the diaphragm is referred to as reverse warping). .), The end portion of the vibration device in the second surface direction is lifted from the mounting surface of the vibration device. Then, the vibration characteristics of the vibration device are greatly deteriorated, and for example, the peak displacement of the diaphragm near the outer periphery in the second surface direction of the vibration device is reduced.

  However, if the spacer is provided, even if the diaphragm is warped in the second surface direction, the end portion of the vibration device in the second surface direction is away from the mounting surface of the vibration device. It becomes difficult to lift up. As a result, in the vibration device, even if the vibration plate has a reverse warp in the second surface direction, the vibration characteristics are hardly deteriorated.

  In the vibration device according to the aspect of the invention, it is preferable that the first portion and the second portion protrude toward the diaphragm. With this configuration, the area where the spacer contacts the diaphragm can be reduced, and the vibration of the diaphragm is not easily inhibited by the spacer.

  In the vibration device according to the aspect of the invention, it is preferable that the protruding length of the first portion is larger than the protruding length of the second portion. With this configuration, the height at which the diaphragm is supported by the spacer can be increased on the outer peripheral side in the second surface direction.

  In the vibration device according to the aspect of the invention, it is preferable that the spacer includes a plurality of legs that are arranged along the second surface direction and protrude from the base surface at a position that does not overlap the film. Thereby, it can prevent that a film contacts the attachment surface of a vibration apparatus, and a more favorable vibration characteristic is acquired.

  In the vibration device according to the aspect of the invention, the plurality of leg portions include a first leg portion facing the first location, and a second leg portion facing the second location, It is preferable that the protruding length of the leg portion is larger than the protruding length of the second leg portion. Also with this configuration, the height at which the diaphragm is supported by the spacer can be increased on the outer peripheral side in the second surface direction.

  In addition, the tactile sense presentation device of the present invention includes the vibration device, a detection unit that is attached to the vibration plate and detects a touch operation, and a control unit that drives the film when the detection unit detects the touch operation. And.

  In the tactile sense presentation device having such a configuration, even if the diaphragm has a reverse warp along the second surface direction, the peak displacement of the diaphragm is not reduced near both ends in the second surface direction. Even if the vicinity of both ends in the second surface direction is touched, tactile feedback can be reliably presented to the operator.

  According to the present invention, in the vibration device or the tactile sense presentation device, the gap portion between the diaphragm and the film can be prevented from being crushed by the spacer. And even if there is a reverse warp along the second surface direction on the diaphragm, both ends of the vibration device are unlikely to lift from the mounting surface, so that deterioration and variations in vibration characteristics can be suppressed.

It is a perspective view of the tactile sense presentation device concerning a 1st embodiment. 2A and 2B are side views showing the operating state of the tactile sense presentation device according to the first embodiment. It is a disassembled perspective view of the tactile sense presentation device concerning a 1st embodiment. It is a top view except the diaphragm of the tactile sense presentation device concerning a 1st embodiment. It is sectional drawing of the tactile sense presentation apparatus which concerns on 1st Embodiment. FIG. 6A and FIG. 6B are cross-sectional views illustrating a state in which the diaphragm in the tactile presentation device according to the first embodiment has a reverse warp. FIG. 7A, FIG. 7B, and FIG. 7C are diagrams showing the displacement distribution in the haptic presentation device according to the first embodiment. It is a disassembled perspective view of the tactile sense presentation device concerning a 2nd embodiment. It is sectional drawing of the tactile sense presentation apparatus which concerns on 2nd Embodiment. FIG. 10A and FIG. 10B are cross-sectional views illustrating a state in which the diaphragm in the tactile presentation device according to the second embodiment has a reverse warp. It is a figure explaining the conventional structure of a vibration apparatus.

  Hereinafter, a tactile sense presentation device and a vibration device according to the present invention will be described based on a first embodiment. FIG. 1 is a perspective view of the tactile sense presentation device 10 and the vibration device 20 according to the first embodiment.

  In the present embodiment, the tactile sense presentation device 10 constitutes a touch sensor type keyboard. In addition, the tactile sense presentation device of the present invention can constitute various devices that come into contact with the user, such as a touch panel and operation buttons, in addition to a keyboard.

  The tactile presentation device 10 includes a control unit 11, a drive unit 12, a vibration device 20, and a plurality of touch sensors 31. The vibration device 20 includes a vibration plate 21, a piezoelectric film 22, and two spacers 70. The piezoelectric film 22 corresponds to an example of the film of the present invention.

  The diaphragm 21 constitutes the top surface of the vibration device 20. The diaphragm 21 is rectangular when viewed from the thickness direction of the vibration device 20, and has a short side along a first surface direction (hereinafter, also referred to as a film stretching direction) orthogonal to the thickness direction of the vibration device 20. It has a long side along a second surface direction (hereinafter also referred to as a film width direction) orthogonal to the thickness direction of the vibration device 20 and the first surface direction. That is, the diaphragm 21 has a shape extending in the first surface direction and the second surface direction orthogonal to each other. Further, the diaphragm 21 is curved convexly on the top surface side and concavely on the bottom surface side when viewed from the second surface direction (film width direction). The diaphragm 21 is made of a material that can be elastically deformed in the thickness direction, such as PP (polypropylene) or PS (polystyrene). The diaphragm 21 may be made of other materials such as a metal plate, PET, PMMA, polycarbonate (PC), a glass epoxy substrate, and glass.

  The plurality of touch sensors 31 are arranged on the top surface of the vibration device 20 (the vibration plate 21) so as to correspond to the keyboard layout. Each touch sensor 31 outputs a detection signal to the control unit 11 when detecting a touch operation by the user. When a detection signal is input from any of the touch sensors 31, the control unit 11 outputs a control signal to the drive unit 12. When the control signal is input from the control unit 11, the drive unit 12 applies a drive voltage to the piezoelectric film 22 of the vibration device 20.

  The piezoelectric film 22 is disposed on the bottom side of the diaphragm 21. Both ends of the piezoelectric film 22 in the first surface direction (film stretching direction) are connected to the diaphragm 21 as fixed ends 24. That is, the piezoelectric film 22 is connected to the vibration plate 21 at a plurality of locations aligned in the first surface direction (film stretching direction) on the bottom surface side of the vibration plate 21. The piezoelectric film 22 has a property of expanding and contracting at least in the first surface direction (film stretching direction) when a driving voltage is applied.

  More specifically, the piezoelectric film 22 is configured by providing electrodes (not shown) on the entire surfaces of both main surfaces of a film made of a piezoelectric material. The piezoelectric material of the piezoelectric film 22 is, for example, a chiral polymer such as L-type polylactic acid (PLLA) or polyvinylidene fluoride (PVDF). When the piezoelectric film 22 is made of PLLA, a direction approximately 45 ° with respect to the main stretching direction from the film that has been stretched in the direction indicated by the white arrow in FIG. By cutting out the piezoelectric film 22 as the film stretching direction), the piezoelectric film 22 can be provided with piezoelectricity that expands and contracts in the first surface direction (film stretching direction).

  The piezoelectric film 22 is stretched on the bottom surface side of the diaphragm 21 in a state where tension is applied in the first surface direction (film stretching direction), whereby the diaphragm 21 is elastically deformed so as to bend in the thickness direction. ing. In this way, the vibration plate 21 and the piezoelectric film 22 constitute a vibration device 20 configured in an arc shape when viewed from the second surface direction (film width direction). In the vibration device 20, the diaphragm 21 vibrates so that the amount of bending changes as the piezoelectric film 22 expands and contracts in the first surface direction (film stretching direction).

  The two spacers 70 are made of, for example, metal, PET, polycarbonate (PC), ABS resin, FRP, or the like. The two spacers 70 are arranged in the first surface direction (film stretching direction) and in the second surface direction (film width direction), respectively, in the gap portions where the diaphragm 21 and the piezoelectric film 22 face each other. Each extends. Both ends of each of the two spacers 70 in the second surface direction (film width direction) are configured to be able to contact an attachment surface (not shown) of the vibration device 20 at a position that does not overlap the piezoelectric film 22. For this reason, the two spacers 70 define the minimum gap between the diaphragm 21 and the piezoelectric film 22 and support the diaphragm 21 and the piezoelectric film 22 so as to face the mounting surface of the vibration device 20.

  FIG. 2A is a side view of the vibration device 20 as viewed from the second surface direction (film width direction). A dotted line in FIG. 2A shows the vibration device 20 when the piezoelectric film 22 is contracted.

  The spacer 70 is sandwiched between the lower surface of the diaphragm 21 and the upper surface of the piezoelectric film 22. Here, the thickness of the spacer 70 is larger than the distance between the diaphragm 21 and the piezoelectric film 22 when the spacer 70 is not provided. As a result, when the piezoelectric film 22 is not driven, the spacer 70 pushes the piezoelectric film 22 downward in the thickness direction, and the piezoelectric film 22 is bent downward at the contact position with the spacer 70.

  When an AC voltage is applied to the piezoelectric film 22 to drive it, the piezoelectric film 22 repeatedly expands and contracts in the first surface direction (film stretching direction). Then, the tension T1 transmitted from the piezoelectric film 22 to the diaphragm 21 is periodically changed. Thereby, the component force T2 in the direction perpendicular to the surface of the fixed end 24 at the tension T1 also periodically changes. Then, as shown by a dotted line in FIG. 2A, the amount of bending of the diaphragm 21 changes periodically.

  Thereby, when the piezoelectric film 22 is contracted, the central portion in the first surface direction (film stretching direction) of the diaphragm 21 is displaced upward, and when the piezoelectric film 22 is extended, the first surface direction (film) of the diaphragm 21 is displaced. The central part in the tension direction is displaced downward. Accordingly, the spacer 70 is periodically displaced up and down, and the angle at which the piezoelectric film 22 is bent at the contact position with the spacer 70 also periodically changes.

  FIG. 2B is a side view illustrating a vibration mode of the vibration device 20 in a state where a pressing force by a touch operation or the like is applied.

  In a state where a pressing force T3 from a finger or the like that is touched is applied to the diaphragm 21 and the diaphragm 21 is pushed to a substantially flat shape, the reaction force T4 against the pressing force T3 is caused by the elastic force of the vibration device 20. Acts on etc. In this state, the spacer 70 is pushed downward together with the diaphragm 21, and the piezoelectric film 22 is bent more greatly than when the pressing force T3 is not applied.

  That is, even if the pressing force T3 is applied to the diaphragm 21 and the diaphragm 21 is pushed to a substantially flat shape, the spacer 70 prevents the gap between the diaphragm 21 and the piezoelectric film 22 from being crushed, and the piezoelectric film The state where 22 is stretched by both fixed ends 24 is maintained. Therefore, even when the diaphragm 21 is flat, the component force T2 of the tension T1 acts in a direction perpendicular to the surface of the fixed end 24.

  For this reason, even if an AC voltage is applied to the piezoelectric film 22 in this state and driven, the tension T1 transmitted from the piezoelectric film 22 to the diaphragm 21 and its component force T2 increase periodically, and the diaphragm 21 is periodically Try to bend greatly. This causes periodic fluctuations in the reaction force T4 transmitted from the diaphragm 21 to a finger or the like pushing the diaphragm 21.

  Thus, in the tactile sense presentation device 10 and the vibration device 20 according to the present embodiment, since the two spacers 70 are arranged in the arcuate gap portion formed by the vibration plate 21 and the piezoelectric film 22, this gap portion is There is no such thing as being completely crushed. Thereby, even if the diaphragm 21 is flattened by being pressed by the user, the diaphragm 21 can be reliably vibrated by the expansion and contraction of the piezoelectric film 22. Therefore, tactile feedback can be reliably given to the user who performs the touch operation. In addition, in the tactile sense presentation device 10 and the vibration device 20, since the gap between the vibration plate 21 and the piezoelectric film 22 is not crushed by the spacer 70, the vibration plate 21 is thinly configured to suppress the rigidity of the vibration plate 21. Therefore, it is possible to increase the amount of bending generated in the diaphragm 21 as compared with the conventional case.

  Next, a more specific structure of the spacer 70 will be described. FIG. 3 is an exploded perspective view of the vibration device 20.

  Each of the two spacers 70 described above includes a plurality of leg portions 71, a base portion 73, a plurality of first protrusions 74, and a plurality of second protrusions 75. The base 73 is a prismatic part and extends between both ends of the spacer 70 in the second surface direction. That is, the base portion 73 extends in the second surface direction (film width direction) through a gap portion sandwiched between the piezoelectric film 22 and the diaphragm 21.

  FIG. 4 is a plan view of the vibration device 20 as seen from the top surface side through the diaphragm 21. 5 is a cross-sectional view of the vibration device 20 taken along the line V-V shown in FIG. In addition, the diaphragm 21 shown in FIG. 5 has no warp along the second surface direction (film width direction).

  The plurality of leg portions 71 are provided so as to protrude from both ends of the base portion 73 in the second surface direction (film width direction) to the bottom surface side in the thickness direction. The interval between the plurality of leg portions 71 in the second surface direction (film width direction) is set to be larger than the dimension of the piezoelectric film 22 in the second surface direction (film width direction). And the piezoelectric film 22 is provided so that it may pass between the some leg parts 71 in a 2nd surface direction (film width direction). More specifically, the piezoelectric film 22 here is in contact with the bottom surface of the base portion 73 between the plurality of leg portions 71 in the second surface direction (film width direction). That is, the plurality of leg portions 71 are arranged along the second surface direction (film width direction) and protrude from the base portion 73 at a position that does not overlap the piezoelectric film 22. The bottom surfaces of the plurality of leg portions 71 constitute a base surface B that can come into contact with the mounting surface of the vibration device 20.

  The first protrusion 74 corresponds to a first portion described in the claims. Moreover, the 2nd protrusion 75 is corresponded to the 2nd location as described in a claim. The first protrusions 74 are provided in the vicinity of both ends of the base 73 in the second surface direction (film width direction). The second protrusion 75 is provided so as to face the center side of the diaphragm 21 with respect to the first protrusion 74 in the second surface direction (film width direction) of the base 73. The first and second protrusions 74 and 75 protrude from the base 73 toward the top surface in the thickness direction, and are provided so as to be able to contact the diaphragm 21 at the respective top surfaces. More specifically, the first protrusion 74 here is configured such that the top surface always contacts the diaphragm 21. On the other hand, when the vibration plate 21 is not deformed, the second protrusion 75 here is separated from the vibration plate 21 and the vibration plate 21 is strongly pressed, or when the vibration plate 21 is reversely warped. In some cases, the top surface is configured to contact the diaphragm 21.

  Here, the top surface of the first protrusion 74 is provided with a small-diameter portion 77 that further protrudes toward the top surface. The diaphragm 21 is provided with an opening 78 penetrating the diaphragm 21 at a position facing the small diameter portion 77 of the first protrusion 74. The small-diameter portion 77 of the spacer 70 is fitted into the opening 78 of the diaphragm 21, whereby the spacer 70 is fixed to the diaphragm 21. In addition to fixing the spacer 70 with such a configuration, the spacer 70 may be fixed to the diaphragm 21 or the piezoelectric film 22 with an adhesive or the like.

  As shown in FIG. 5, the protruding length of the first protrusion 74 from the base 73 is set to be larger than the protruding length of the second protrusion 75 from the base 73. In other words, the height of the first protrusion 74 from the base surface B is set to be larger than the height of the second protrusion 75 from the base surface B.

  The spacer 70 configured as described above prevents the entire top surface of the spacer 70 from coming into contact with the diaphragm 21 even when the diaphragm 21 is strongly pressed and flattened by the second protrusion 75. be able to. That is, the area of the contact portion between the spacer 70 and the diaphragm 21 can be reduced. As a result, it is possible to suppress the vibration of the diaphragm 21 from being restrained by the contact portion with the spacer 70 and deteriorating.

  The spacer 70 is fixed by fitting a small diameter portion 77 provided on the top surface of the first protrusion 74 and an opening 78 provided on the diaphragm 21 when viewed from the top surface side. 21 is fixed with a strong binding force. Thus, even if the spacer 70 is fixed to the diaphragm 21 by the small-diameter portion 77 having a very small size, the positional deviation is hardly caused. Therefore, the tactile sense presentation device 10 and the vibration device 20 are less likely to deteriorate the vibration characteristics due to the displacement of the spacer 70. However, the position where the small diameter portion 77 is provided is not limited to the top surface of the first protrusion 74, and may be provided on the top surface of the second protrusion 75. The method for fixing the spacer 70 is not limited to the fitting between the small-diameter portion 77 and the opening 78, and is realized by bonding with an adhesive or the like, or clamping between the diaphragm 21 and the piezoelectric film 22. May be.

  In such a tactile sense presentation device 10 and the vibration device 20, in reality, the thinly configured vibration plate 21 does not become completely flat, and is slightly in the first surface direction or the second surface direction. Warping occurs.

  6 is a diagram illustrating a case where the diaphragm 21 has a reverse warp along the second surface direction, and FIG. 6A is a cross-sectional view of a vibration device 20A according to a comparative example, and FIG. ) Is a cross-sectional view of the vibration device 20 according to the present embodiment.

  The vibration device 20A according to the comparative example includes a spacer 70A as a configuration different from that of the vibration device 20 according to the present embodiment. The spacer 70A has the same protrusion length from the base portion 75A of the first protrusion 74A and the second protrusion 75A. Therefore, in the vibration device 20 </ b> A, not only the first protrusion 74 </ b> A but also the second protrusion 75 </ b> A always has the top surface in contact with the diaphragm 21.

  In both the vibration device 20 according to the present embodiment and the vibration device 20A according to the comparative example, the warpage of the vibration plate 21 occurs along the second surface direction (film width direction). For this reason, like the vibration device 20A according to the comparative example, the spacer 70A having a uniform protrusion length between the first protrusion 74A and the second protrusion 75A has the same curvature as the curvature of the reverse warp of the diaphragm 21. A reverse warp occurs along the second surface direction. Then, if the curvature of the reverse warp of the diaphragm 21 is larger than a certain level, the piezoelectric film 22 on the bottom surface side of the spacer 70 </ b> A contacts the mounting surface A of the vibration device 20 </ b> A, and the piezoelectric film 22 expands and contracts. 22 may slide with the mounting surface A, and the end of the spacer 70A may float from the mounting surface A.

  On the other hand, in the vibration device 20 according to this embodiment, since the protrusion length of the first protrusion 74 and the protrusion length of the second protrusion 75 are larger, the margin until the second protrusion 75 contacts the diaphragm 21. If the curvature of the reverse warp of the diaphragm 21 does not increase beyond a certain level, the second protrusion 75 does not contact the diaphragm 21 and the spacer 70 does not warp. Further, the curvature of the reverse warp of the diaphragm 21 is so large that the second protrusion 75 comes into contact with the diaphragm 21, and even if the spacer 70 also has a reverse warp, the curvature thereof is the reverse warp of the diaphragm 21. It becomes smaller than the curvature. Therefore, in the vibration device 20 according to the present embodiment, even if the vibration plate 21 has a reverse warp along the second surface direction (film width direction), the piezoelectric film 22 contacts the mounting surface A of the vibration device 20. The end portion of the spacer 70 is unlikely to be lifted from the mounting surface A of the vibration device 20.

  For this reason, the vibration device 20 according to the present embodiment can easily obtain better vibration characteristics of the diaphragm 21 than the vibration device 20A according to the comparative example.

  FIG. 7A shows the vibration device 20A according to the comparative example in a state where the vibration plate 21 has no (small) reverse warp along the second surface direction, and the end portion of the vibration plate 21 does not float from the mounting surface. 5 is a diagram illustrating vibration characteristics of a diaphragm 21. FIG. FIG. 7B shows the vibration characteristics of the diaphragm 21 in a state where the diaphragm 21 has a reverse warp along the second surface direction and the end portion of the diaphragm 21 is lifted in the vibration device 20A according to the comparative example. It is a figure illustrated. FIG. 7C is a diagram illustrating the vibration characteristics of the diaphragm 21 in the vibration device 20 according to this embodiment when the diaphragm 21 has a reverse warp along the second surface direction.

  In any of the figures, a sinusoidal voltage having an amplitude of 100 V and a voltage frequency that matches the resonance frequency of the diaphragm 21 is applied to the piezoelectric film 22, and the displacement in the thickness direction (peak) of the diaphragm 21 in that state is applied. Value) was measured with a laser displacement meter (LK-G157 manufactured by Keyence) while sequentially moving the measurement points.

  In the vibration device 20A according to the comparative example, as shown in FIG. 7A, when the diaphragm 21 has no reverse warp along the second surface direction, the second surface direction of the diaphragm 21 (film) The amount of displacement in the thickness direction of the diaphragm 21 was uniformly distributed from the center portion in the width direction) to both ends, and the amount of displacement in the thickness direction did not decrease at both ends in the second surface direction (film width direction).

  However, in the vibration device 20 </ b> A according to the comparative example, as illustrated in FIG. 7B, when the vibration plate 21 has a reverse warp along the second surface direction, the second surface direction of the vibration plate 21. Although the displacement in the thickness direction at the center of (film width direction) did not decrease much, the displacement in the thickness direction greatly decreased at both ends in the second surface direction (film width direction).

  On the other hand, in the vibration device 20 according to the present embodiment, as shown in FIG. 7C, even if the vibration plate 21 has a reverse warp along the second surface direction, The amount of displacement in the thickness direction of the diaphragm 21 is uniformly distributed from the center in the surface direction (film width direction) to both ends, and the amount of displacement in the thickness direction decreases at both ends in the second surface direction (film width direction). There was no.

  As described above, according to the vibration device 20 of the present embodiment, even if the vibration plate 21 has a reverse warp in the second surface direction (film width direction), the vibration characteristics of the vibration plate 21 are unlikely to deteriorate. Therefore, in the vibration device 20 of the present embodiment, the allowable range of warpage of the members of the diaphragm 21 is widened, and the trouble of selecting the diaphragm 21 with less warpage can be saved, with less labor and low cost. Product characteristics of the vibration device 20 and the tactile sense presentation device 10 can be stabilized. In addition, when the diaphragm 21 is attached to the vibration device 20 so as to warp in the opposite direction to the reverse warp along the second surface direction (film width direction), or warps along the first surface direction. In this case, there is no problem that both ends of the vibration device 20 (spacer 71) are lifted. Therefore, in the vibration device 20 according to the present embodiment, it is possible to save the trouble of attaching the vibration device 21 after determining the warping direction of the vibration plate 21, and this also reduces the vibration at a low cost with less work. Product characteristics of the device 20 and the haptic presentation device 10 can be stabilized.

  Next, the vibration device 20B according to the second embodiment will be described. FIG. 8 is an exploded perspective view of the tactile sense presentation device according to the second embodiment. FIG. 9 is a cross-sectional view of the vibration device 20B. Hereinafter, the same reference numerals are given to the same components as those according to the first embodiment, and the description thereof is omitted. Note that the diaphragm 21 shown in this figure also has no warpage in the second surface direction.

  The vibration device 20B includes a plurality of piezoelectric films 22B and a spacer 70B as a configuration different from that of the first embodiment. The plurality of piezoelectric films 22B are arranged side by side in the second surface direction of the vibration device 20B.

  The spacer 70B includes, in addition to the leg portions 71B projecting from both ends in the second surface direction of the base portion 73B to the bottom surface side in the thickness direction, between the plurality of piezoelectric films 22B in the second surface direction, A leg portion 72B protruding toward the bottom surface in the thickness direction is further provided. That is, the plurality of leg portions 71B and 72B are arranged along the second surface direction (film width direction) and protrude from the base portion 73B to the bottom surface side at a position not overlapping the plurality of piezoelectric films 22B. And the bottom face of each of the plurality of leg portions 71B, 72B constitutes a base face B that can contact the mounting face of the vibration device 20B. Therefore, the leg portion 71B corresponds to the first leg portion described in the claims, and the leg portion 72B corresponds to the second leg portion described in the claims.

  In this embodiment, when the spacer 70B is not deformed, the protruding length of the first leg 71B from the base 73B is larger than the protruding length of the second leg 72B from the base 73B. Is set. On the other hand, the first protrusion 74B and the second protrusion 75B are set so that the protruding lengths from the respective base portions 73B are equal to each other. In the spacer 70B having such a configuration, the first protrusion 74B and the second protrusion 75B are always in contact with the diaphragm 21, but the height of the first protrusion 74B from the base surface B is It becomes larger than the height from the base surface B of 2 protrusion 75B.

  FIG. 10 is a diagram illustrating a case where the diaphragm 21 has a reverse warp along the second surface direction. FIG. 10A is a cross-sectional view of the vibration device 20C according to the comparative example, and FIG. ) Is a cross-sectional view of the vibration device 20B according to the present embodiment.

  The vibration device 20C according to the comparative example includes a spacer 70C as a configuration different from the vibration device 20B according to the present embodiment. The spacer 70C has the same protruding length from the base portion 75C of the first leg portion 71C and the second leg portion 72C.

  In both the vibration device 20B shown in FIG. 10B and the vibration device 20C shown in FIG. 10A, a reverse warp occurs in the vibration plate 21 along the second surface direction. In both the vibration device 20B and the vibration device 20C, the top surfaces of the first protrusion and the second protrusion are in contact with the vibration plate 21. For this reason, both the vibration device 20 </ b> B according to the present embodiment and the vibration device 20 </ b> C according to the comparative example cause reverse warpage along the second surface direction with the same curvature as the curvature of the reverse warp of the diaphragm 21.

  For this reason, in the vibration device 20C according to the comparative example, at least one of the leg portions 71C at both ends is lifted from the mounting surface A of the vibration device 20C even if the reverse warping of the vibration plate 21 is minute.

  On the other hand, in the vibration device 20B according to the present embodiment, the base surface B of the second leg portion 72B does not contact the mounting surface A of the vibration device 20B unless the curvature of the reverse warp of the vibration plate 21 is large to a certain extent. The first leg portion 71B does not float from the mounting surface A of the vibration device 20B.

  For this reason, even with the vibration device 20B according to the present embodiment, better vibration characteristics of the diaphragm 21 can be obtained more easily than with the vibration device 20C according to the comparative example. That is, also in the vibration device 20B of the present embodiment, in the spacer 70B, the height from the base surface B of the first protrusion 74B is larger than the height from the base surface B of the second protrusion 75B. Even if the diaphragm 21 has a reverse warp along the second surface direction, the vibration characteristics of the diaphragm 21 are unlikely to deteriorate. Therefore, the allowable range of the warp of the members of the diaphragm 21 as the diaphragm 21 is widened, and the product characteristics of the vibration device 20B can be easily stabilized.

  In each of the embodiments described above, an example in which the vibration device is used as a tactile sense presentation device has been described. However, the vibration device of the present invention is not limited to this, and may be, for example, another device such as a flat speaker. It may be used.

  In each of the above-described embodiments, an example in which a piezoelectric film is used as a film has been shown. However, the film of the present invention is not limited to this, and for example, an electrostrictive film, an electret film, a piezoelectric ceramic, and a piezoelectric particle It can also be composed of a composite film dispersed in a polymer, an electroactive polymer film, or the like. An electroactive polymer film is a film that generates stress by electrical drive, or a film that deforms and generates displacement by electrical drive. Specifically, there are an electrostrictive film, a composite material (a material obtained by resin-molding piezoelectric ceramics), an electrically driven elastomer, or a liquid crystal elastomer.

  Moreover, in each embodiment mentioned above, although the example provided with a 1st protrusion, a 2nd protrusion, and a leg as a spacer was shown, the spacer of this invention is not restricted to this, For example, there is no protrusion. The spacer may have a flat top surface, or the top surface may be a gentle curved surface that is recessed near the center in the second surface direction. Alternatively, only the first protrusion may be provided and the second protrusion may not be provided. The spacer may be a spacer having a flat bottom surface without a leg portion, and the bottom surface may be a gently curved surface that is recessed near the center in the second surface direction.

  Moreover, you may combine the structure used as the characteristic in each embodiment mentioned above mutually. That is, the vibration device and the tactile sense presentation device can be configured to include first and second protrusions having different protrusion lengths and first and second legs having different protrusion lengths, respectively.

  Finally, the description of the above-described embodiments should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above embodiments but by the claims. Furthermore, the scope of the present invention is intended to include all modifications within the meaning and scope equivalent to the scope of the claims.

A ... Mounting surface B ... Base surface 10 ... Tactile sense presentation device 11 ... Control unit 12 ... Drive unit 20 ... Vibrating device 21 ... Vibration plate 22 ... Piezoelectric film 24 ... Fixed end 31 ... Touch sensor 70 ... Spacer 71 ... Leg portion 71B ... First leg 72B ... second leg 73 ... base 74 ... first protrusion 75 ... second protrusion

Claims (6)

A diaphragm,
A film that is connected to the diaphragm at a plurality of locations aligned in the first surface direction of the diaphragm and vibrates the diaphragm by expanding and contracting;
A spacer that supports the diaphragm so as to face the mounting surface through a gap portion between the film and the diaphragm;
The spacer includes a base surface that can contact the mounting surface, a first location that can contact the diaphragm, and a first surface direction that intersects the first surface direction of the diaphragm. A second location that can contact the center side of the diaphragm rather than the location of
The height from the basal surface of the first location when the spacer is not deformed is greater than the height from the basal surface of the second location,
Vibration device. The first part and the second part protrude toward the diaphragm,
The vibration device according to claim 1. The protruding length of the first location is greater than the protruding length of the second location,
The vibration device according to claim 2. The spacer includes a plurality of legs that are aligned along the second surface direction and project to the base surface at a position that does not overlap the film.
The vibration device according to any one of claims 1 to 3. The plurality of legs include a first leg that faces the first location, and a second leg that faces the second location,
The vibration device according to claim 4, wherein a protruding length of the first leg portion is larger than a protruding length of the second leg portion. A vibration device according to any one of claims 1 to 5,
A detection unit mounted on the diaphragm for detecting a touch operation;
A tactile sense presentation device comprising: a drive unit that drives the film when the detection unit detects a touch operation.

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