JP2013020467A - Touch panel and electronic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a sufficient haptic function in a low frequency region and realize a sound emission function without sound quality degradation in a high frequency region.SOLUTION: A front surface 14A of a partition plate 14 partitioning the inside of a housing 12 in a thickness direction supports a back surface of a display panel 20. A case 32 of a speaker 30 formed by affixing a piezoelectric element 36 to a diaphragm 34 is mounted on a back surface 14B of the partition plate 14 through cushioning materials 50. The case 32 of the speaker 30 is connected to a housing surface 12A with a sound guiding path 42. The hardness of the cushioning materials 50 and the total length of the plural cushioning materials 50 with respect to the boundary length of the speaker 30 each are set within a proper range. Controlling the rigidity of a coupling part between the speaker 30 and the display panel 20 realizes a haptic function in a low frequency region because of vibration transmission to the display panel 20 and realizes a speaker function having excellent sound quality in a high frequency region because of no vibration transmission to the display panel 20.

Description

  The present invention relates to a touch panel device and an electronic device, and more specifically to a touch panel device and an electronic device having a haptic function that senses an input by touch and a speaker function (including a receiver function).

  A pressure-sensitive or capacitive touch panel is used as an input device for a display device such as a liquid crystal panel used in a mobile phone or the like, but unlike a normal mechanical switch, the depth of depression when pressed is small. It is difficult to detect with the fingertip or not. For this reason, a touch panel device having a haptic function that generates a mechanical movement such as vibration in response to the pressing and senses the pressing tactilely has been developed.

  As a drive source for realizing the haptic function, a method of vibrating a display device portion with an actuator is usually employed (for example, Patent Document 1 below). As an input signal for exhibiting the haptic function, for example, a (sine wave) signal having a frequency of about 200 Hz is used. Further, depending on the configuration, it is possible to provide a function as a speaker or a receiver that vibrates the panel of the display device portion and reproduces music or voice by inputting a voice signal to the actuator (for example, the following patents) Reference 2).

JP 2010-157037 A JP 2006-040005 A

  However, when a touch panel display device having a haptic function is used to simultaneously realize a speaker function, the actuator is originally designed for driving at a relatively low frequency. When driving at 20000 Hz, sufficient vibration could not be obtained on the high frequency side, leading to the problem of deterioration in sound quality.

  The present invention focuses on the above points, and has a speaker function that can realize a sufficient haptic function in a low frequency region and a sound emitting function without deterioration in sound quality in a high frequency region. It is an object of the present invention to provide a touch panel device and an electronic device.

  The touch panel device of the present invention partitions a display panel provided with a display unit on the back side of the touch panel, a housing attached so that the touch panel side of the display panel can be seen from the outside, and the inside of the housing in the thickness direction. A partition plate that supports the back surface of the display unit of the display panel, and supports the periphery of the vibration portion that is configured by attaching a piezoelectric element to the main surface of the diaphragm, and is entirely covered with a case, A speaker attached to the partition plate via a cushion material so as to be on the opposite side of the display panel across the partition plate, and penetrating the partition plate to connect the speaker case and the surface of the housing And a sound guide path opened on the surface of the housing.

  One of the main forms is that a plurality of the cushion materials are arranged uniformly along the periphery of the speaker case, and the total length of the plurality of cushion materials on the periphery side of the case is the case. It is characterized by being 1/3 to 1/2 of the perimeter of. In another embodiment, the cushion material is made of a rubber material having a rubber hardness of 40 to 60. Yet another embodiment is characterized in that the speaker case is made of a metal material having a Young's modulus of 100 GPa or more.

  An electronic apparatus according to the present invention includes any one of the touch panel devices described above. The above and other objects, features and advantages of the present invention will become apparent from the following detailed description and the accompanying drawings.

  According to the present invention, a speaker case in which a back surface of a display panel is supported by one surface of a partition plate that partitions the inside of a housing in a thickness direction, and a piezoelectric element is attached to a vibration plate on the other surface is cushioned. The speaker case and the housing surface are connected by a sound guide path. With such a configuration, by controlling the rigidity of the coupling part between the piezoelectric speaker capable of generating a large force and the display panel, vibration is transmitted to the display panel in a low frequency region, thereby obtaining a sufficient haptic function. In the high frequency range, the cushioning material blocks the transmission of vibration to the display panel, so that it is possible to realize a speaker function that emits sound with good sound quality.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the smart phone of Example 1 of this invention, (A) is the whole external appearance perspective view, (B) is the cross section which cut | disconnected said (A) along the # A- # A line and looked at the arrow direction. FIG. 4C is a partially enlarged view of FIG. FIG. 3 is a cross-sectional view showing a multilayer structure of the piezoelectric element of Example 1. It is a figure which shows the mounting surface of the speaker to a partition plate, (A) is a figure which shows the said Example 1, (B) is a figure which shows a modification. It is a graph which shows the sound pressure characteristic and surface vibration characteristic of the smart phone of the said Example 1. FIG.

  Hereinafter, the form for implementing this invention is demonstrated in detail based on an Example.

  First, Embodiment 1 of the present invention will be described with reference to FIGS. The present invention can realize a sound emission function without deterioration for an electronic device having a touch panel display panel unit having a haptic function, such as a mobile phone, a smart phone, a car navigation device, or a game machine. The present invention relates to a technology with a speaker function. In the present embodiment, a smartphone will be exemplified and described as the electronic device. FIG. 1 is a diagram illustrating a smartphone according to the present embodiment, where (A) is an overall perspective view of the smartphone, and (B) is a view of (A) cut along line # A- # A and viewed in the direction of an arrow. Sectional drawing which shows the outline of a cross section, (C) is an enlarged view of the principal part of said (B). FIG. 2 is a cross-sectional view showing an example of the laminated structure of the piezoelectric elements of this example. 3A and 3B are diagrams illustrating a mounting surface of the speaker on the partition plate, where FIG. 3A is a perspective view illustrating the speaker according to the first embodiment, and FIG. 3B is a plan view illustrating a speaker according to a modified example. FIG. 4 is a graph showing sound pressure characteristics and surface vibration characteristics of the smartphone of this example.

  As shown in FIGS. 1 (A) and 1 (B), the smartphone 10 of this embodiment is provided with a touch panel type display panel 20 having a haptic function on a part of the surface 12A side of the housing 12. The surface 12A is provided with a sound emitting hole 44 of the built-in speaker 30 and an operation switch 45. In the present invention, the direction in which the display panel is viewed visually is defined as the front side (or upper side), and the opposite direction is defined as the back side (or lower side). The display panel 20 has a configuration in which a display device 24 is provided below a touch panel 22. As the touch panel 22, a known existing method such as a resistance film method may be used in addition to a capacitance type. it can. As the display device 24, a display device using organic EL can be used in addition to a display device using liquid crystal.

  The inside of the housing 12 is partitioned in the thickness direction by the partition plate 14, and the back surface of the display device 24 of the display panel 20 is supported by the surface 14 </ b> A of the partition plate 14. The partition plate 14 maintains the rigidity of the casing 12 and supports the display device 24. The display device 24 is fixed to the display device 24 with, for example, a double-sided tape. On the other hand, the speaker 30 is mounted on the back surface 14 </ b> B side of the partition plate 14, that is, on the surface opposite to the display panel 20 via a plurality of cushion materials 50. In the illustrated example, the speaker 30 is disposed on one side surface 12 </ b> C side of the housing 12. As shown in FIG. 1C, the speaker 30 is entirely covered with a case 32 so as to support the periphery of a vibration part in which a piezoelectric element 36 is attached to the main surface of a diaphragm 34. Yes. The upper surface 32A of the case 32 and the housing surface 12A are connected by a sound guide path 42 that penetrates the partition plate 14, and the sound guide path 42 opens as a sound emitting hole 44 in the housing surface 12A. ing.

  In this embodiment, as the piezoelectric element 36, as shown in FIG. 2, a laminated element that forms a bimorph structure in the element is used. The piezoelectric element 36 shown in FIG. 2 has a structure in which a plurality of piezoelectric layers 38 and electrode layers 40 are alternately laminated. In this embodiment, the upper side 36A and the lower side 36B in the center in the thickness direction A bimorph structure polarized so that the polarization direction is reversed was used. The piezoelectric element 36 may have a single-plate structure that is not laminated at all, depending on the structure of the electronic device to be mounted, or even when laminated, all the piezoelectric layers are polarized in the same direction with respect to the electric field. Although it is possible to adopt the unimorph structure, it is desirable to use a laminated structure from the viewpoint of keeping the input voltage low, and from the viewpoint of increasing the generated displacement and generated force, it should be a bimorph structure. Is desirable. As the material of the piezoelectric layer 38, for example, a piezoelectric material obtained by adding an additive to lead zirconate titanate is used, but other materials can be used as long as they are generally known piezoelectric ceramics. Good. As a material of the electrode layer 40, various known electrode materials such as silver and platinum can be used. In this embodiment, a piezoelectric element 36 in which six piezoelectric layers 38 having a thickness of 18 μm are stacked is used. Further, since the diaphragm 34 needs to support the piezoelectric element 36 without hindering the bending vibration of the piezoelectric element 36, for example, a film of a soft material such as urethane elastomer or rubber is used. In this embodiment, a urethane elastomer having a thickness of 100 μm is used, and the piezoelectric element 36 is pasted with an adhesive.

  The speaker 30 is entirely covered with a case 32 so as to support the periphery of a vibrating portion composed of the diaphragm 34 and the piezoelectric element 36. Since the case 32 requires high rigidity, it is preferable to use a metal material (for example, stainless steel) having a Young's modulus of 100 GPa or more and a thickness of 0.1 mm or more. If the rigidity is less than this, vibration transmission is hindered and a sufficient haptic function cannot be obtained. A sound guide path 42 that passes through the partition plate 14 and opens at the surface 12A of the housing 12 is connected to the upper surface 32A of the case 32. At that time, the connecting portion is sealed so that sound does not leak outside.

The speaker 30 configured as described above is attached to the back surface 14B of the partition plate 14 via the cushion material 50 described above. The cushion material 50 is for controlling the rigidity of the case 32 and the partition plate 14 of the speaker 30 and has the same shape and the same shape along the periphery of the speaker 30 as shown in FIG. The plurality of cushion materials 50 having the dimensions are arranged uniformly. In this embodiment, a rubber material having a rubber hardness of 40 to 60 is used as the cushion material 50. In addition, when the length of the cushioning material 50 on the peripheral side of the speaker 30 is L and the number of installations is n, the total length (n × L) of the plurality of cushioning materials is the peripheral length of the speaker 30 ( the total _{length) L sp} of the four sides, so that the 1 / 3-1 / 2, is uniformly arranged. When a material harder than the above-mentioned hardness is used, or when the length (n × L) with respect to the peripheral length _Lsp of the speaker 30 is longer than ½, vibration is transmitted even in the high frequency region. The display panel 20 vibrates and causes deterioration in sound quality. Further, when the hardness of the rubber is 40 to 60 or less, or the total length (n × L) of the cushion material 50 with respect to the speaker circumferential length _Lsp is shorter than 1/3, vibration transmission is performed even in a low frequency region. Is not performed and the haptic function cannot be demonstrated. The length L of the cushion member 50 satisfies the relation between the speaker known length _{L sp,} and is about 3 to 5 mm, a width W is set to 0.5mm or more 2mm or less, the thickness T is from 0.1 to 0 About 5 mm.

  Next, the operation of this embodiment will be described. When the touch panel 22 is pressed according to the display content displayed on the display panel 20, it is detected that the touch panel 22 has been pressed, and a low-frequency drive signal is input to the piezoelectric element 36 in accordance with the detected touch panel 22 to vibrate. Let Since the cushion material 50 interposed between the speaker 30 and the partition plate 14 transmits a low frequency component, vibration is transmitted to a finger or the like that presses the display panel 20, and the pressing can be sensed tactilely. is there. For example, when a sine wave of 200 Hz was input to the piezoelectric element 36 of the speaker 30, it was confirmed that the display panel 20 vibrated by 7 μm and a haptic function could be realized. On the other hand, when a high-frequency drive signal is input to the piezoelectric element 36, the cushion material 50 does not transmit a high-frequency component, suppresses vibration of the display panel 20, and generates sound radiated from the sound guide path 42 to the outside. Sound quality does not deteriorate. For example, when a signal of 600 Hz or more is input, the vibration of the display panel 20 is as small as 1 μm or less, and no deterioration in sound quality due to sound emitted from the surface of the display panel 20 was observed.

  FIG. 4 shows the sound pressure characteristics and surface vibration characteristics of the smartphone 10 of this embodiment. In the figure, the horizontal axis represents the frequency [Hz] of the input signal, and the vertical axis represents the response level [dB]. As shown in the figure, the surface vibration shows a high response level up to a frequency of about 250 Hz, and it was confirmed that a sufficient haptic function can be realized on the low frequency side. As for the sound pressure characteristics, the response level gradually increased up to 1000 Hz, and the high response level was shown in the high frequency region of 1000 Hz or higher, so it was confirmed that the sound quality did not deteriorate in the high frequency region. .

As described above, according to the first embodiment, the back surface of the display panel 20 is supported by the front surface 14A of the partition plate 14 that partitions the inside of the housing 12 in the thickness direction, and the back surface 14B of the partition plate 14 is piezoelectrically coupled to the vibration plate 34. A case 32 of the speaker 30 to which the element 36 is attached is mounted via a cushion material 50, and the case 32 of the speaker 30 and the housing surface 12A are connected by a sound guide path. Then, it was decided to set the hardness of the cushion member 50, the total length of the plurality of cushioning members 50 to the surrounding length L _sp speaker 30 within an appropriate range. With such a configuration, the rigidity of the coupling portion between the piezoelectric speaker capable of generating a large force and the display panel 20 is controlled, and vibration is transmitted to the display panel 20 in a low frequency region, thereby obtaining a sufficient haptic function. It is done. Further, since the cushion member 50 does not transmit vibration to the display panel in a high frequency region, it is possible to realize a speaker function that emits sound with good sound quality.

In addition, this invention is not limited to the Example mentioned above, A various change can be added in the range which does not deviate from the summary of this invention. For example, the following are also included.
(1) The shapes, dimensions, etc. shown in the above embodiments are merely examples, and may be changed as appropriate. For example, in the first embodiment, the speaker 30 has a rectangular shape, but may have a circular shape as shown in FIG. 3B, for example. Also in this case, the optimum range of the total length of the cushion material 50 with respect to the circumference of the speaker 60 (that is, the circumference) is the same as that of the first embodiment described above.
(2) Although the piezoelectric element 36 shown in the above embodiment has a bimorph structure, this is also an example, and may have a unimorph structure.
(3) In the above embodiment, the speaker 30 has been described as an example. However, the speaker according to the present invention indicates a speaker in a broad sense, and the technique of the present invention can naturally be applied to a receiver.
(4) In the above-described embodiment, the piezoelectric element 36 has a laminated structure. However, this is also an example, and a single plate structure may be used. In the case of a laminated structure, the number of laminated layers may be increased or decreased as necessary. .
(5) Various known materials can be used as the material for forming the piezoelectric element 36.
(6) In the case of the stereo system, two left and right speakers are prepared. In this case, the embodiment may be applied to each speaker, or the embodiment may be applied to one of the speakers. May be. In that case, the two piezoelectric elements may be driven by the same signal, or may be driven by signals having different frequencies and waveforms.
(7) In the above-described embodiment, the smartphone 10 has been described as an example of the electronic device to which the touch panel device of the present invention is applied. The present invention can be applied to a display device having a touch panel function and electronic devices using the display device.

  According to the present invention, a speaker case in which a back surface of a display panel is supported by one surface of a partition plate that partitions the inside of a housing in a thickness direction, and a piezoelectric element is attached to a vibration plate on the other surface is cushioned. A sound guide path is provided to connect the speaker and the surface of the housing by mounting through a material. With such a configuration, by controlling the rigidity of the coupling portion between the piezoelectric speaker capable of generating a large force and the display panel, vibration is transmitted to the display panel in the low frequency region, and the cushion in the high frequency region. Since the material does not transmit vibration to the display panel, it can be applied to applications such as touch panel display devices and electronic devices having a haptic function and a speaker function.

10: Smartphone 12: Housing 12A: Front surface 12B: Rear surface 12C: Side surface 14: Partition plate 14A: Front surface 14B: Rear surface 20: Display panel 22: Touch panel 24: Display device 30: Speaker 32: Case 32A: Upper surface 34: Diaphragm 36: Piezoelectric element 36A: Upper side 36B: Lower side 38: Piezoelectric layer 40: Electrode layer 42: Sound conduction path 44: Sound emission hole 45: Operation switch 50: Cushion material 60: Speaker

Claims (5)

A display panel provided with a display on the back side of the touch panel;
A housing attached so that the touch panel side of the display panel can be visually recognized from the outside;
Partitioning the inside of the housing in the thickness direction, and supporting a back surface of the display unit of the display panel;
While supporting the periphery of the vibration part constituted by pasting the piezoelectric element on the main surface of the diaphragm, the whole is covered with a case, and on the opposite side of the display panel across the partition plate, A speaker attached to the partition plate via a cushion material;
The sound guide path that penetrates the partition plate, connects the speaker case and the surface of the housing, and is opened on the surface of the housing;
A touch panel device comprising:   A plurality of the cushion materials are evenly arranged along the periphery of the speaker case, and the total length of the plurality of cushion materials on the periphery side of the case is 1/3 of the periphery length of the case. The touch panel device according to claim 1, wherein the touch panel device is ½.   The touch panel device according to claim 1, wherein the cushion material is made of a rubber material having a hardness of 40 to 60 rubber.   The touch panel device according to claim 1, wherein the speaker case is made of a metal material having a Young's modulus of 100 GPa or more.   An electronic device comprising the touch panel device according to any one of claims 1 to 4.

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