JP2011043925A - Flexurally vibrating actuator and touch panel with tactile sensation feedback function using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a flexurally vibrating actuator which is suitable for the purpose of use of a touch panel, and small and light in weight, has high resistance to falling, is made thin and improved in productivity, and a touch panel with a tactile sensation feedback function using this flexurally vibrating actuator. <P>SOLUTION: The flexurally vibrating actuator 1 is provided with: a vibrator configured of a shim 5 composed of a thin plate-shaped body and piezo-elements 7 respectively mounted on both the surface and back sides of the shim 5; a vibrator holding part 3 for holding the one end or central section of the longitudinal direction of the shim 5 as a root side end section; and a cushion layer 10 mounted on the piezoelectric element 7 on at least one surface. Also, this touch panel with a tactile sensation feedback function is configured such that the flexural vibration type actuator 1 is fixed by the vibrator holding part 3 at the prescribed place of the peripheral edge of the back surface of the touch panel body 20 by arranging the cushion layer 10 at least on the side opposite to the surface facing the touch panel body 20. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a flexural vibration type actuator that is used in a touch panel, is small, lightweight, has high drop resistance, is thin and has improved productivity, and a touch panel with a tactile feedback function using the same.

  Conventionally, there has been a configuration described in Patent Document 1 below as an invention of a small and light flexural vibration type actuator used for a speaker such as a cellular phone. The invention described in Patent Document 1 includes an elongated plate-like vibrator composed of a shim made of an elongated plate-like body and piezoelectric flexural vibration elements (piezo elements) attached to both the front and back surfaces of the shim, and the length of the vibrator. A vibrator holding portion that holds one end or the central portion of the direction as a base side end portion, and a protective plate on the front surface of the display panel of the electronic device is applied to the bending vibration excited by the vibrator via the vibrator holding portion. In a flexural vibration type actuator that excites a flexural vibration to the diaphragm by transmitting to the diaphragm that also serves as the diaphragm, the vibrator holding unit is held and spaced apart below the vibrator, and the longitudinal direction of the vibrator It is the structure provided with the baseplate of the elongate plate-like body extended by (1).

  In Patent Document 1, when an electronic device such as a cellular phone in which this actuator is formed falls on a hard floor such as concrete, a piezoelectric flexural vibration element is formed by excessive flexural vibration of a vibrator generated by the impact. Since there is a possibility of breakage, measures for suppressing this excessive bending vibration are also disclosed. That is, an opening for vibration suppression is formed in a bent portion that stands upright from the tip of a base plate made of a long and thin rectangular metal plate, and the tip of the shim of the vibrator is inserted into the opening. This suppresses excessive bending vibration (hereinafter, this vibration suppression mechanism is referred to as a “stopper”).

JP 2008-252878 A

  However, the method of providing the stopper that suppresses excessive bending vibration of the vibrator is not a problem when used for speakers, but a tactile sensation is obtained by attaching a bending vibration type actuator to the back of the touch panel and vibrating the panel during input. When it was used for the purpose of obtaining, a new problem occurred. That is, a large load is applied to the touch panel body each time input is made to the touch panel. When the touch panel body bends due to the input load, there is a problem in that an unpleasant sound is generated due to interference between the tip of the vibrator of the actuator attached to the touch panel body and the opening of the base plate.

  Further, when a stopper is provided, the base plate made of a metal plate is fixed to the touch panel with a length up to the tip of the vibrator, so that the allowable range of bending of the touch panel is limited, and the thickness of the base plate is further increased. In addition, since the height of the bent portion that stands upright from the tip is required to be a dimension that can serve as a stopper, there has been a problem that the total thickness of the actuator becomes thick and bulky.

  In addition, providing such stoppers one by one is very laborious and causes a problem of reducing productivity.

  Accordingly, an object of the present invention is to solve the above-described problems, and is a flexible and flexural vibration type actuator that is suitable for touch panel applications, is small, lightweight, has high drop resistance, is thin and has improved productivity, and the same. The object is to provide a touch panel with a tactile feedback function.

  In order to solve the above technical problem, the present invention provides a flexural vibration type actuator having the following configuration and a touch panel with a tactile feedback function using the same.

  According to the first aspect of the present invention, a vibrator comprising a shim comprising an elongated plate-like body and piezoelectric elements respectively attached to both the front and back surfaces of the shim, and one end or a central portion in the longitudinal direction of the shim at the base side end Provided is a flexural vibration type actuator that includes a vibrator holding portion that is held as a portion and a cushion layer that is mounted on at least one surface of the piezoelectric element.

  Moreover, according to the 2nd aspect of this invention, the bending vibration type actuator of a 1st aspect with which the said cushion layer is provided only in the front-end | tip part on the said piezoelectric element is provided.

  Further, according to the third aspect of the present invention, a vibrator comprising a shim comprising an elongated plate-like body and piezoelectric elements respectively attached to both the front and back surfaces of the shim, and one end or a central portion in the longitudinal direction of the shim Provided is a flexural vibration type actuator comprising a vibrator holding portion that is held as a side end portion, and a cushion layer that is attached to at least one side of the shim on the tip side of the piezo element and is thicker than the piezo element. .

  According to the fourth aspect of the present invention, the flexural vibration type actuator according to any one of the first to third aspects has at least a surface of the cushion layer facing the touch panel body at a predetermined position on the periphery of the back surface of the touch panel body. Provides a touch panel with a tactile feedback function which is arranged on the opposite side and fixed by a vibrator holding part.

  The flexural vibration type actuator according to the present invention is characterized in that a high drop resistance is obtained without a stopper by providing the cushion layer. Since no stopper is provided, no unpleasant sound is generated even if the touch panel body is bent when inputting to the touch panel.

  Further, since the stopper is not provided, the actuator can be fixed to the touch panel body only by the vibrator holding portion, and there is an effect that the allowable range of bending of the touch panel is increased.

  Furthermore, since only the cushion layer is provided, there is an effect that the total thickness of the actuator can be reduced as compared with the conventional technique in which the stopper is provided.

  Further, in the flexural vibration type actuator of the present invention, when the cushion layer is provided only at the tip portion of the vibrator, the frequency of the vibrator can be set to a desired low value by the weight of the cushion layer. This has the effect of improving movement.

It is sectional drawing which showed schematic structure of one Example of the bending vibration type actuator of this invention. FIG. 2 is a schematic perspective view of the flexural vibration type actuator of FIG. 1. It is sectional drawing which showed schematic structure of the other Example of the bending vibration type actuator of this invention. FIG. 4 is a schematic perspective view of the flexural vibration type actuator of FIG. 3. It is sectional drawing which showed schematic structure of the other Example of the bending vibration type actuator of this invention. FIG. 6 is a schematic perspective view of the flexural vibration type actuator of FIG. 5. It is the schematic of the touchscreen with a tactile feedback function using the vibration type actuator of this invention. It is sectional drawing which shows the example of a change of the cushion layer of this invention. It is a top view which shows the example of a change of the cushion layer of this invention.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  The flexural vibration type actuator 1 is placed on the back surface of the touch panel main body 20 as shown in FIG. 7 in a touch panel with a tactile feedback function, and a casing, a liquid crystal display, etc. (not shown) are provided below the flexural vibration type actuator 1. Other parts are installed. 7A is an exploded perspective view as viewed from the front surface side of the touch panel with tactile feedback function, and FIG. 7B is a perspective view as viewed from the rear surface side of the touch panel with tactile feedback function. In general, the flexural vibration type actuator has a structure in which a shim 5 made of an elongated plate-like body, a vibrator comprising a piezo element 7 attached to both the front and back surfaces of the shim 5, and one end in the longitudinal direction of the shim 5 at the base side. The vibrator holding unit 3 is held as an end. The flexural vibration type actuator 1 of the present invention includes a cushion layer 10 attached on one of the piezoelectric elements 7 as shown in FIGS. 1 and 2, and the cushion layer 10 faces the touch panel body 20. It is arranged on the side opposite to the surface and fixed by the vibrator holding part 3. Therefore, when an electronic device such as a mobile phone on which this actuator is formed falls on a hard floor such as concrete, even if the vibrator vibrates excessively due to the impact and hits other parts such as a housing or a liquid crystal display Since the cushion layer 10 absorbs and softens the impact when the vibrator hits the casing or parts, the piezoelectric element 7 of the vibrator is not damaged.

  Examples of the material of the cushion layer 10 include various thermoplastic elastomers, rubber resins such as butadiene, silicon, and urethane. The thickness of the cushion layer 10 can be appropriately set within a range of 5 to 3000 μm. If the thickness is less than 5 μm, the function of absorbing impact cannot be exhibited, and if the thickness exceeds 3000 μm, the processing becomes bulky and difficult. For thin films, printing, painting, coating, etc. are suitable for thin films, and for thick films, potting or casting is used.

  The cushion layer 10 may be formed so as to cover the entire surface of the piezo element 7 as shown in FIGS. 1 and 2, or may cover a part of the piezo element 7 as shown in FIGS. Also good. In the case of covering a part, it is preferable to use a tip part away from the vibrator holding part 3. This is because the frequency at which the vibrator vibrates is lowered by the weight of the cushion layer 10 installed at the distal end, and can be easily converted to a desired low frequency.

  Further, the cushion layer 10 may be attached to the front side of the piezo element 7 without covering the piezo element 7 on one side of the shim 5 as shown in FIGS. 5 and 6. However, the thickness of the cushion layer 10 needs to be thicker than that of the piezo element 7 so that other components such as a casing and a liquid crystal display may hit the cushion layer 10 before the piezo element 7.

  The cushion layer 10 may not be provided with a uniform thickness. For example, a part of the surface may protrude as shown in FIG. 8A, or an uneven surface may be formed as shown in FIG. Since the moment of contact comes in contact with a point or a part instead of a full contact, the impact can be absorbed gently.

  Further, the cushion layer 10 may be divided into a plurality of pieces. For example, they may be arranged as shown in FIG. 9A or arranged concentrically as shown in FIG. 9B. Also in these cases, since the moment of contact is partial contact instead of full contact, the impact can be absorbed gently.

  Moreover, although the cushion layer 10 is arrange | positioned only in the opposite side to the surface facing the touch-panel main body 20 in FIGS. 1-6, you may arrange | position also in the surface facing the touch-panel main body 20 in addition. In this case, an effect that interference with the touch panel body 20 can be prevented is obtained.

  Note that providing a shock absorbing piece for absorbing shock and avoiding damage to the shim at the tip of the shim of the vibrator is slightly described in Patent Document 1, but is different from the present invention. The shock absorbing piece of Patent Document 1 absorbs the shock generated when the tip of the shim collides with the inner periphery of the opening of the base plate, and collides with other parts such as a casing and a liquid crystal display as in the present invention. It is different from the one that absorbs the impact generated by this and prevents the piezo element 7 from being damaged. Therefore, the thickness of the shock absorbing piece of Patent Document 1 is not limited.

  The vibrator holding part 3 is made of a columnar body made of a molding resin such as acrylic, styrene, or polypropylene, and the base side end of the shim 5 is a narrow slit with a rectangular cross section formed inside the vibrator holding part 3. It is press-fitted inside.

  The shim 5 is made of a metal plate made of stainless steel, aluminum alloy, nickel alloy or the like having a width of about 2 to 6 mm, a length of about 1 to 5 cm, and a thickness of about 0.1 to 1.0 mm.

  Examples of the piezo element 7 include a laminate in which a plurality of piezoelectric ceramic thin plates such as barium titanate are sandwiched between electrode layers. As a method of attaching the piezo elements 7 and 7 to both the front and back surfaces of the shim 5, there is a method of adhering with an epoxy adhesive or the like. By supplying AC operating power to both piezo elements 7, 7, warpage occurs, and the vibrator vibrates.

  The flexural vibration excited by the vibrator is transmitted from the vibrator holding unit 3 to the touch panel body 20. Since the tactile sensation is fed back by vibrating the touch panel body 20 during input, an input sensation can be obtained. In addition, by precisely calculating and designing the mounting position of the flexural vibration type actuator 1, a distributed vibration mode (DM) speaker can be formed on the touch panel body 20.

  Examples of a method for attaching the flexural vibration type actuator 1 to the back surface of the touch panel body 20 include a method in which an adhesive layer, a double-sided tape layer, and the like are interposed. When the base material of the touch panel body 20 is a resin film such as polyester, acrylic, or polycarbonate, the flexural vibration type actuator as in the conventional patent document 1 becomes too rigid if the base plate is firmly bonded, and the touch panel may be bent. become unable. On the other hand, in the flexural vibration type actuator 1 of the present invention, since it is fixed by the vibrator holding unit 3, it can follow the touch panel body 20 while maintaining the adhesiveness.

 The structure using the cantilever type vibrator that holds one end of the vibrator has been illustrated above. However, a flexural vibration type actuator configured to form a vibrator in the form of a cantilever on both sides in the longitudinal direction of the vibrator holding part, or a form in which the central part in the longitudinal direction of the vibrator is fixed by the vibrator holding part. The present invention can also be applied to a flexural vibration type actuator.

  A piezo element with a total thickness of about 0.3 mm was bonded to both sides of a shim made of stainless steel with a width of 3 mm, a length of 3 cm, and a thickness of 0.2 mm, with a barium titanate sheet sandwiched between electrode layers. After applying and curing a silicone rubber-based resin liquid to the thickness of 0.2 mm as one of the above-mentioned cushion layers on one side of the piezo, the shim is attached to the vibrator holding portion to bend and vibrate An actuator was obtained.

  The obtained flexural vibration type actuator was excellent in drop resistance without providing a stopper. And after pasting on the touch panel, even if the touch panel was bent, no unpleasant sound was generated.

  A piezo with a total thickness of about 0.3 mm in which a plurality of barium titanate thin plates are sandwiched between electrode layers on both sides of a shim made of a nickel alloy having a width of 2.5 mm, a length of 2.5 cm, and a thickness of 0.2 mm. After the element was provided in the same manner as in Example 1, a 0.2 mm thick urethane rubber liquid was potted as the cushion layer on the tip of one side of the piezo, and the shim was attached to the vibrator holding part and bent. A vibration type actuator was obtained.

  The obtained flexural vibration type actuator was excellent in drop resistance without providing a stopper. And after pasting on the touch panel, even if the touch panel was bent, no unpleasant sound was generated.

  A piezo element having a total thickness of about 0.3 mm, in which a plurality of barium titanate thin plates are sandwiched between electrode layers on both sides of a shim made of stainless steel having a width of 2.5 mm, a length of 3 cm, and a thickness of 0.2 mm. After being provided in the same manner as in Example 1, a section of a thermoplastic urethane elastomer sheet having a thickness of 0.4 mm and a 2 mm square was attached as a cushion layer to at least one side of the tip of the shim, and then the shim was attached. A bending vibration type actuator was obtained by attaching to the vibrator holding part.

  The obtained flexural vibration type actuator was excellent in drop resistance without providing a stopper. And after pasting on the touch panel, even if the touch panel was bent, no unpleasant sound was generated. In addition, this flexural vibration type actuator can reduce the frequency of the vibrator to a desired low value by the weight of the cushion layer, and the movement at the low frequency is improved.

DESCRIPTION OF SYMBOLS 1 Flexural vibration type actuator 3 Vibrator holding part 5 Shim 7 Piezo element 10 Cushion layer 20 Touch panel main body

Claims (4)

A vibrator comprising a shim comprising an elongated plate-like body and piezoelectric elements respectively attached to both the front and back surfaces of the shim;
A vibrator holding portion that holds one end or a central portion in the longitudinal direction of the shim as a root side end; and
Comprising a cushion layer mounted on at least one side of the piezo element,
A flexural vibration type actuator characterized by the above.   The flexural vibration type actuator according to claim 1, wherein the cushion layer is provided only at a tip portion on the piezo element. A vibrator comprising a shim comprising an elongated plate-like body and piezoelectric elements respectively attached to both the front and back surfaces of the shim;
A vibrator holding portion that holds one end or a central portion in the longitudinal direction of the shim as a root side end; and
At least one side of the shim is attached to the tip side of the piezo element, and includes a cushion layer that is thicker than the piezo element.
A flexural vibration type actuator characterized by the above.   The flexural vibration type actuator according to any one of claims 1 to 3 is arranged at a predetermined position on a peripheral edge of the back surface of the touch panel body, and the vibration is disposed at least on the side opposite to the surface facing the touch panel body. A touch panel with a tactile feedback function, which is fixed by a child holding portion.

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