WO2013109128A2

WO2013109128A2 - Display panel comprising ultra-thin piezoelectric speaker

Info

Publication number: WO2013109128A2
Application number: PCT/KR2013/000603
Authority: WO
Inventors: 이충희; 이동수; 박인석
Original assignee: Lee Choong Hee
Priority date: 2012-01-17
Filing date: 2013-01-25
Publication date: 2013-07-25
Also published as: KR20130084358A; KR101325678B1; WO2013109128A3

Abstract

A display panel comprising an image module, a reflective sheet, and a frame, comprises an audio module which is interposed between the reflective sheet and the frame, wherein the audio module comprises a main piezoelectric driving body, a vibration plate which is physically coupled to the main piezoelectric driving body, and a support portion for supporting either the main piezoelectric driving body and/or the vibration plate from one fixed point positioned on the inside of an outer circumference of the main piezoelectric driving body, wherein the support portion is supported by the frame so that a free end of the outer circumference of the main piezoelectric driving body and the vibration plate can vibrate with the fixed point at the center.

Description

【Specification】

[Name of invention]

Display panel with ultra-thin piezoelectric speakers

Technical Field

The present invention relates to a display panel, and more particularly, to a display panel that can include a speaker function while maintaining a conventional thin thickness. Background Art

The display panel mainly uses an imaging module such as liquid crystal display modules or organic LED modules. These models are available in several sub-thickness thicknesses and are being developed with excellent performance.

1 is an exploded perspective view of a tablet device including a display panel.

Referring to FIG. 1, a general tablet device 10 may include a glass plate 20 on the front surface, a display panel 30 disposed on the rear surface of the glass plate 20, and a case covering the rear surface while accommodating internal parts thereof. 40). Substantially, the inside of the tablet device 10 is composed of a display panel 20, a battery (not shown), a speaker (not shown), and the like, and a PCB is provided in the space therebetween to construct the inside. have.

As the use of the tablet device 10 extends from simple internet surfing to various uses such as watching movies, watching TV, and listening to music, interest in sound has increased. However, due to problems such as volume and mounting space, the current speaker module is provided in monaural, and the speaker provided in mono occupies a relatively large space, which can be a big obstacle in the layout design of internal components.

This problem is not limited to tablet devices, but may be applied to flat-panel televisions that are being developed recently. For example, conventional flat-panel televisions are getting thinner and thinner and the thickness of the flat-panel televisions is becoming a concern.

<7> Some piezoelectric speakers have been developed as ultra-thin speakers. A piezoelectric speaker is a device that converts electrical energy into sound energy using a piezoelectric element, and generates sound when an electrical signal is supplied to a PZT-based piezoelectric material.

In the conventional piezoelectric speaker, the edge of the diaphragm is fixed to the frame, and the piezoelectric drive body is bonded to the center of the diaphragm to generate vibration. However, the conventional piezoelectric speaker is suitable for mainly generating high frequency sounds, and there is a limit in generating low frequency sounds. Therefore, the sound range which the conventional magnetic circuit speaker can produce Due to this limitation, piezoelectric speakers are mainly used for limited sound such as buzzers.

In other words, in the conventional piezoelectric speaker, since the outer periphery of the diaphragm is fixed, the distance (λ / 2) of the fixed portion is the lowest frequency that can be reproduced in the piezoelectric speaker. Therefore, the conventional piezoelectric speaker is capable of only a high frequency above the lowest frequency, and is actually used only for reproducing a specific frequency or reproducing high sound.

[Detailed Description of the Invention]

[Technical problem]

The present invention provides a display panel using a piezoelectric element, but including a sound function capable of generating both high and low frequency sounds evenly.

<π> The present invention can provide a sound effect while maintaining the conventional thickness of the display panel almost intact, and saves the space occupied by the conventional speaker mode, the display panel that can be expected to slim the overall device and the mounting space efficiency to provide.

The present invention provides a display panel including a sound function having an improved physical structure to overcome the material limitations of the piezoelectric element.

The present invention provides a display panel that can easily complete the electrical connection or assembly by using a piezoelectric element.

Technical Solution

According to an exemplary embodiment of the present invention, a display panel including an image module, a reflective sheet, and a frame includes acoustic modules interposed between the reflective sheet and the frame, wherein the acoustic films are main piezoelectric elements. Drive body includes a vibration plate physically coupled to the main piezoelectric drive body, and a support for supporting at least one of the main piezoelectric drive body and the diaphragm at a fixed point located inside the outer periphery of the main piezoelectric drive body, the support portion frame The outer circumference of the main piezoelectric drive body and the diaphragm may be vibrated freely around the fixed point.

In the conventional piezoelectric speaker, the outer circumference of the diaphragm or its expansion plate is fixed to the housing to generate only a limited range of sounds. Can generate sound. That is, the main piezoelectric drive body and the diaphragm are integrally coupled so that vibration of the piezoelectric drive body can be transmitted through the diaphragm, and the support portion supports the piezoelectric drive body or the diaphragm at a fixed point located inside the outer circumference of the piezoelectric drive body. . As described above, although the use of the piezoelectric ceramic is fixed by fixing the outer circumference of the conventional piezoelectric speaker, in the present invention, The piezoelectric drive body and the diaphragm can be supported at the central portion or the periphery of the support rather than at the outer periphery, and may be such that the outer periphery is a free end rather than a fixed end. Therefore, the piezoelectric drive body and the diaphragm of the present invention can improve the low band performance more than the conventional piezoelectric speaker, and can secure characteristics similar to those of a conventional magnetic circuit speaker.

Also, acoustic caps may be directly or indirectly attached to the rear surface of the reflective sheet, and when two or more acoustic caps are attached to each other, the stereo sound may be improved compared to the conventional mono sound. It is also possible to use the reflection sheet for acoustic vibrations, and to use an amplification sheet having better acoustic characteristics than the reflection sheet.

The thickness increased by the acoustic heads and the support part is only about 0.5 to 1 瞧 or less, thereby realizing improved sound quality as well as saving of innovative mounting space.

An amplifier may be used to improve the sound generated. The amplifying unit may increase the amount of movement of the supporting part by opposing the operation of the main piezoelectric driving body, and may further increase the amplitude of the diaphragm by moving the supporting part in the direction in which the free ends of the piezoelectric driving body and the diaphragm move. Therefore, the sound output can be further increased, and the limitation of the deformation of the conventional piezoelectric element can be structurally overcome.

Although the fixed point position of the main piezoelectric drive body supported by the support portion may be formed at the center of the diaphragm, it may be formed at an eccentric position. The distance from the fixed point to the outer periphery of the diaphragm can be provided in various ways, which can be expected to be the same as using speakers of various dimensions. In other words, the distance from the fixed point to the outermost point of the diaphragm and the outermost point of the diaphragm can be varied to provide various ranges of characteristics.

Advantageous Effects

The display panel of the present invention includes a sound function capable of evenly generating both high and low frequency sounds while maintaining a conventional flat plate shape and slim thickness.

The display panel of the present invention can be expected to reduce the space occupied by the conventional speaker modules, thereby making the overall device slim and the mounting space efficiency.

The display panel of the present invention provides an improved physical structure to overcome the material limitations of the piezoelectric element.

The display panel of the present invention provides a display panel that can easily complete the electrical connection or assembly using a piezoelectric element. Conventional piezoelectric speakers tend to depend on the materials of piezoelectric ceramics, but the development of piezoelectric ceramics has been slow to develop, and thus the improvement of the piezoelectric speakers has not been satisfactory. On the other hand, in the display panel of the present invention, it is possible to structurally improve the function of the acoustic caps by using a single layer or a multi-layer amplification plate, to overcome the limitations of the existing piezoelectric speaker, and to generate an improved sound. have.

[Brief Description of Drawings]

1 is an exploded perspective view of a tablet device including a display panel.

2 is a rear perspective view of a display panel according to an exemplary embodiment of the present invention.

FIG. 3 is an exploded perspective view of the display panel of FIG. 2.

FIG. 4 is a cross-sectional view for describing a support relationship between the acoustic caps and the frame of FIG. 2.

FIG. 5 is a cross-sectional view illustrating a sound generating principle of the acoustic hair of FIG. 4.

FIG. 6 is a partially enlarged perspective view for explaining an improved structure of the acoustic caps of FIG. 4.

FIG. 7 is a diagram illustrating a configuration of an acoustic system for controlling the acoustic modules of FIG. 2.

FIG. 8 is a cross-sectional view illustrating an improved embodiment of the acoustic caps of FIG. 4.

FIG. 9 is a cross-sectional view illustrating acoustic hairs of a display panel according to another exemplary embodiment.

10 and 11 are cross-sectional views for explaining the operation principle of acoustic caps including an amplifier.

12 is a cross-sectional view for describing an operating mechanism in which the acoustic hairs of FIG. 9 operate according to the principles of FIGS. 10 and 11.

[Form for implementation of invention]

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings, but the present invention is not limited or limited by the embodiments. For reference, in the present description, the same numbers refer to substantially the same elements, and may be described by quoting contents described in other drawings under such a rule, and the contents repeated or deemed apparent to those skilled in the art may be omitted.

2 is a rear perspective view of a display panel according to an embodiment of the present invention, FIG. 3 is an exploded perspective view of the display panel of FIG. 2, and FIG. 4 illustrates a support relationship between the acoustic caps and the frame of FIG. 2. It is sectional drawing for doing. 2 to 4, the display panel 100 includes image caps 110, a reflective sheet 120, acoustic caps 140, and a frame 130. The display panel 100 may be mounted on a personal mobile terminal, a mobile phone, a tablet device, or the like, and may be applied to a television or a monitor.

The acoustic modules 140 may include the main piezoelectric drive body 142 and the diaphragm 144, and may be provided by an electric signal supplied to both sides of the main piezoelectric drive body 142. Sieve 142 and diaphragm 144 can vibrate. In this embodiment, the inner surface of the main piezoelectric drive body 142 may be electrically connected through the diaphragm 144.

The image modules 110 may be provided with conventional flat panel display modules. For example, conventional liquid crystal display modules as well as organic light emitting diode models can be used. In the case of liquid crystal display modules, the image caps 110 may be provided as an assembly including a liquid crystal as well as an optical sheet that may be provided on the front and rear surfaces, and backlighting caps that may be provided on the back or side surfaces. . In addition, in the case of organic light emitting diode models, the image modules 110 may be provided as an assembly including a 0LED substrate and an optical sheet. In addition, the image module 110 may be replaced with a flat panel display module of the present or future. The back of the image caps 110 may be provided with a frame 130 made of stainless steel, etc., and a reflective sheet 120 may be provided between the frame 130 and the image caps 110. . The frame 130 accommodates the image caps 110 and the reflective sheet 120 and may be used for protecting and fixing the image caps 110 and the like with respect to the display terminal.

Acoustic heads 140 are mounted between the reflective sheet 120 and the frame 130. For this purpose, the space between the reflective sheet 120 and the frame 130 may be about 0.5 to 1.0 mm apart. Tok can be designed. In response to this, the acoustic heads 140 include a main piezoelectric drive body 142 and a diaphragm 144, and are supported by the support part 148 about a specific fixed point 147.

Referring to FIG. 4, the acoustic hairs 140 are supported by the fixing point 147 at the support part 148 including the main piezoelectric drive body 142 and the diaphragm 144. In the present embodiment, the frame 130 has an open rear surface, but includes a bridge portion 132 formed to be inclined, and the acoustic hairs 140 are disposed between the bridge portion 132 and the reflective sheet 120. All. In addition, the support portion 148 is formed by protruding a portion of the bridge portion 132 of the frame 130 inward. Thus, the support 148 supports the main piezoelectric drive body 142 at the fixed point 147. The main piezoelectric drive body 142 and the diaphragm 144 vibrate around the fixed point 147, and the outer circumferences of the main piezoelectric drive body 142 and the diaphragm 144 can vibrate as free ends. As the piezoelectric drive body 142, PZT series or P 顧-containing PbO, Zr0 ₂₎ Ti0 ₂ .

: Piezoelectric single crystal), and various materials using the piezoelectric effect may be added. The main piezoelectric drive body 142 may be provided in a flat plate shape or other flexible solid shape ^. The diaphragm 144 may be formed by using a metal plate, synthetic resin, paper, or the like, and in the case of a metal, brass, aluminum, stainless steel, or the like may be used.

FIG. 5 is a cross-sectional view illustrating a sound generating principle of the acoustic hair of FIG. 4. Referring to FIG. 5, the main piezoelectric driver 142 and the vibration 144 around the fixed point 147 may form various waveforms. In this case, since the fixed point 147 is fixed, waveforms of various wavelengths λ may be specified, and may be variously formed from short wavelengths such as ③ to long wavelengths such as ②. Thus, the overall band of the acoustic edge can be extended. For reference, ① shows the length of the wavelength when compared with the conventional piezoelectric spigot of the same dimensions.

In the present embodiment, the vibration of the main piezoelectric driver 142 and the diaphragm 144 may be connected to the reflective sheet 20, and may generate more rich guns using the vibration of the reflective sheet 120. Of course, the diaphragm 144 and the reflection ^' sheet 20 can be directly bonded to each other by a ring-shaped adhesive sheet as in the present embodiment, but in some cases, separately providing an amplifying sheet to which the copper 144 is coupled, At the time of the witness with the acoustic hairs 140 attached, the reflective sheet 120 may be interposed between the frame 130. Reflective sheet 20 may already be optimized by the final assembly manufacturer for its excellent reflection properties, which may not be optimized for acoustic amplification. Therefore, the acoustically optimized amplification sheet and the reflective sheet optimized for light reflection may be separately used. FIG. 6 is a partially enlarged perspective view illustrating an improved structure of the acoustic caps of FIG. 4.

Referring to FIG. 6, since the bridge portion 132 is formed of a conductor such as stainless steel, an insulating film 150 may be interposed between the acoustic module 140 and the bridge portion 132. However, for electrical connection, the insulating film 150 may be formed with a hole or a groove-shaped pipe, and the wire 146 may be formed on the main piezoelectric drive 142 and the diaphragm 144 through the through part 152, respectively. Can be electrically connected. FIG. 7 is a diagram illustrating a configuration of an acoustic system for controlling the acoustic modules of FIG. 2.

Referring to FIG. 7, a controlled signal for music or sound from a terminal may be transmitted to the acoustic module 140 through the voltage amplifier 160. Conventional speakers may use the voltage amplification amplifier 160 to operate the main piezoelectric driver 142 as opposed to using a current amplifier.

Of course, in this case, it may also be possible for the acoustic modules 140 to generate vibrations of 80-100 Hz or less. In this case, the voltage amplification amplifier 160 may not only control the sound control signals but also the vibration control signals. Also supplied with it can be used to combine the sound generation and vibration generation to the acoustic head 140 without a separate vibration actuator.

Conventionally, in contrast to the case where the acoustic amplifier and the vibration amplifier are separately installed, in the present embodiment, the vibration region of the acoustic modules 140 is increased to use the sound amplifier and the voltage amplifier 160. It is possible to generate vibrations simultaneously or simultaneously, which has the advantage of being able to solve the problem of component cost and mounting space at the same time.

Referring to FIG. 8, the acoustic heads include a main piezoelectric driving body 142 and a diaphragm 144, and are supported by the fixing point 147 at the support 148 ′. In this embodiment, the support portion 148 'is not integrally formed in the bridge portion 132, but may be provided as an insulator projection interposed between the acoustic hairs and the bridge portion 132 against the fixed point 147. . Of course, it may be provided in the form attached to the main piezoelectric drive body 142 or attached to the bridge portion 132. A support ₁₄ 8 ′ supports the main piezoelectric drive body 142 at the fixed point 147, and the main piezoelectric drive body 142 and the diaphragm 144 vibrate around the fixed point 147, so that the main The outer circumferences of the piezoelectric drive body 142 and the diaphragm 144 can vibrate as free ends.

FIG. 9 is a cross-sectional view for describing acoustic hairs of a display panel according to another exemplary embodiment of the present invention, and FIGS. 10 and 11 are cross-sectional views for explaining the operation principle of acoustic hairs including an amplifier part, and FIG. 12. 10 is a cross-sectional view for explaining an operating mechanism in which the acoustic modules of FIG. 9 operate according to the principles of FIGS. 10 and 11.

Referring to FIG. 9, the acoustic hairs 240 are supported by the bridge portion 232. Basically, the acoustic heads 240 include a main piezoelectric drive body 242 and a diaphragm 244, and are supported by the fixing point 247 at the support portion 248.

In addition, the acoustic modules 240 may further include an amplifier 270. Amplifier 270 is It may be supported by the frame, and a support 248 may be provided. The support part 248 may move together according to the height change of the amplification part 270, and the main piezoelectric drive body 242 and the diaphragm 244 may be sequentially coupled to and adhered to the support part 248.

The support part 248 includes the main piezoelectric drive body 242 and the diaphragm based on the fixed point 247.

244 is connected. Therefore, the main piezoelectric driving body 242 and the diaphragm 244 are fixed by the support part 248, and can vibrate the fixed point 247 in the center in response to the acoustic electric signal. In this case, the fixing point 247 may be defined at a central portion of the main piezoelectric driver 242, that is, at a point on the inner side thereof rather than the outer circumference thereof. As the acoustic electric signal is applied, the fixing point 247 stops with respect to the support part 248, and the outer circumferential portions of the main piezoelectric drive body 242 and the diaphragm 244 may vibrate up and down as free ends. The vibration of the main piezoelectric drive body 242 is transmitted to the vibration plate 244 to transmit sound energy to the air.

10 and 11, the amplifier 270 may change in response to the operation of the main piezoelectric driver 242. For example, the amplifier 270 may also include other piezoelectric elements, and other piezoelectric elements may also react to the acoustic electrical signal, such that the main piezoelectric driver 242 responds to the acoustic electrical signal. In addition, if the material, structure, and device that can change the height at the same time to the acoustic electric signal can be used as an amplifier.

The acoustic electric signal is also applied to the amplifier 270, and the height h can be changed according to the signal. Referring to (a) of FIG. 11, the outer circumferences of the main piezoelectric drive body 242 and the diaphragm 244 face upwards, so that the height of the amplification part 270 can also be increased by a predetermined amount Δΐι. In this case, the outer periphery of the diaphragm 244 may be changed by the amount of change (Aw + Ah) increased by the amount of the work with respect to the original amount of change (Aw) for the support portion 248. In addition, referring to FIG. 11 (b), the outer circumferences of the main piezoelectric drive body 242 and the diaphragm 244 face downward, so that the height of the amplifying unit 270 may also be reduced by a predetermined amount Δ1. In this case, the outer periphery of the diaphragm 244 may be changed by the amount of change (-Δν-Δ1ι) reduced by the predetermined amount with respect to the original amount of change (−Δ \ ν) with respect to the support part 248.

As a result, the amplification part 270 causes the change amount (-ᅀ w to + ᅀ w) of the outer periphery of the diaphragm 244 to oscillate with the change amount (-Δ \ ν-Δ1ι to + Δν + Δ1 with a further amplitude increase. This can in turn be related to the output of the acoustic changer, and even with the same piezoelectric ceramics as before, it can generate sound with increased output.

Referring to FIG. 12, the amplifier 270 includes an auxiliary piezoelectric driver 272 and an amplifier plate 274, and the piezoelectric driver and the amplifier plate forming two layers interact with each other. The amount of circumferential change of 244 can be further increased.

As described above, it has been described with reference to the preferred embodiment of the present invention, but those skilled in the art various modifications of the present invention without departing from the spirit and scope of the present invention described in the claims below. And can be changed.

Claims

[Range of request]

[Claim 1]

A display panel comprising an image module, a reflective sheet and a frame accommodating a rear surface of the image modules and the reflective sheet,

A main piezoelectric drive body, a vibration plate physically coupled to the main piezoelectric drive body, and a support portion for supporting at least one of the main piezoelectric drive body and the diaphragm at a fixed point located inside the outer circumference of the main piezoelectric drive body. Includes sound modules,

The acoustic modules are interposed between the reflective sheet and the frame, and the support part is supported by the frame so that the outer circumferences of the main piezoelectric drive body and the diaphragm vibrate freely at the fixed point. Display panel using main piezoelectric actuator.

[Claim 2]

The method of claim 1,

And the image modules are liquid crystal display modules or organic light emitting diode modules.

[Claim 3]

The method of claim 1,

And the diaphragm is directly adhesively fixed to the rear surface of the reflective sheet.

[Claim 4]

The method of claim 1,

An amplification sheet is further interposed between the acoustic caps and the reflective sheet, and the vibrating plate is directly adhesively fixed to the rear surface of the amplifying sheet.

[Claim 5]

The method of claim 1,

The support panel is formed by protruding a part of the frame partially inwardly against the fixing point.

[Claim 6]

The method of claim 1,

The support portion may be attached to the acoustic caps and the frame yarn against the fixed point. Display panel, characterized in that the insulating projections interposed therebetween.

[Claim 7]

The method of claim 1

And the frame further includes a bridge portion for supporting the support portion at the fixing point.

[Claim 8]

The method of claim 1,

The acoustic panels may further include an amplifier configured to increase the amount of movement of the support part in response to the operation of the main piezoelectric driver.

[Claim 9]

The method of claim 8,

And the amplifier includes an auxiliary piezoelectric drive body and an amplifier plate to which the auxiliary piezoelectric drive body is attached, and the amplification unit increases the movement of the diaphragm in synchronization with the operation of the main MAP drive.

[Claim 10]

The method according to claim 9,

And the amplifying unit provides the amplifying plate and the auxiliary piezoelectric driver in at least one layer structure.

[Claim 11]

The method of claim 1,

The acoustic panels use a voltage amplifier for amplifying a signal supplied to the diaphragm.