JP2005204102A - Sound generator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sound generator for preventing decrease in the sound pressure level, by effectively blocking the entering and exiting of air between a protective panel and a liquid crystal display unit. <P>SOLUTION: The upper part of a gap g1, formed between the inner edge of the frame body 32 of a display unit 30 stored in a display laminate and the outer edge of a deflection filter 31 installed in the uppermost layer of the display laminate is sealed with a sealing member S. Since airtightness of a cavity Q1, as the counter region of the display unit 30 and the protective panel 20, can be enhanced, the entering and exiting of air of the cavity Q1 with the outside can be blocked, even if the protective panel 20 oscillates and the expansion and shrinkage of pressure are repeated in the cavity Q1. As a result, a decrease in sound pressure level can be prevented. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a sound generator that generates sound from, for example, a translucent protective panel that protects the surface of a liquid crystal display, and more particularly, to a sound generator that improves sound pressure level.

  For example, a panel speaker that generates sound through the protective panel by vibrating a translucent protective panel that protects the surface of a liquid crystal display mounted on a flat-screen TV, a computer, a mobile phone, or the like has been developed. ing.

  As a prior art of such a panel speaker, for example, the following Patent Document 1 exists.

  In Patent Document 1, for example, as shown in FIG. 9, the protection panel is fixed via an elastic member so as to cover the opening formed on the surface side of the frame. A liquid crystal display is disposed at the bottom of the frame so as to face the protective panel, and a cavity is formed between the protective panel and the liquid crystal display device by surrounding the periphery with an elastic member. A vibration exciter is attached to the protective panel.

In the panel speaker, the vibration exciter is driven to apply vibration to the protective panel, so that the protective panel serves as a diaphragm to generate sound.
JP 2002-533957 A

  In the above-described panel speaker, the expansion and compression of the atmospheric pressure in the cavity is repeated by the vibration of the protective panel (diaphragm). At this time, the airtightness of the cavity is maintained to block the air in and out. Therefore, it is necessary to prevent a decrease in sound pressure level.

  However, in general, the liquid crystal display is provided with a first deflection filter in the lowermost layer provided facing the backlight, and in order, a first glass substrate, an X-direction transparent electrode layer, a first alignment layer, a liquid crystal, A second alignment layer, a Y-direction transparent electrode layer, a color filter, a second glass substrate are provided, and a laminated structure is provided in which the second deflection filter is provided as the uppermost layer.

  For this reason, even if the cavity is formed by enclosing the protective panel and the liquid crystal display device with an elastic member, when vibration occurs in the protective panel, the air between the cavity and the liquid crystal display device As a result, the sound pressure level as a panel speaker tends to be lowered.

  The present invention is for solving the above-described conventional problems, and it is possible to prevent the sound pressure level from being lowered by effectively blocking the entry and exit of air between the protective panel and the liquid crystal display device. The object is to provide a generator.

The present invention provides a display device in which a laminate composed of a plurality of layers is housed in a frame, and only the uppermost layer member of the laminate is exposed to the outside of the frame, and a protection disposed opposite to the display device. A panel, a sealing member that elastically supports the protective panel with respect to the display device, and that blocks a facing region formed between the display device and the protective panel from an external space, and vibrates the protective panel. A sound generating device having a vibration generating means for generating sound by giving
A sealing member that blocks an air flow between the gap and the facing region by sealing a gap formed between the inner wall of the frame and the laminated body. Is provided.

  In the sound generator of the present invention, since the airtightness of the cavity, which is the facing region between the display device and the protective panel, can be increased, the protective panel (vibrating plate) vibrates and the pressure is expanded and compressed in the cavity. Even if the above is repeated, the entry and exit of air between the inside and outside of the cavity can be blocked. Therefore, it is possible to prevent a decrease in sound pressure level.

  For example, the sealing member can be configured to cover the gap formed between the inner edge of the frame and the edge of the uppermost member of the laminate from the outside of the frame.

  In the above, the sealing member is either a film sheet having a stretch property in the film thickness direction, a rubber sheet, or a double-sided adhesive tape in which an adhesive layer is formed on both sides thereof in a tape shape. preferable.

  Or it is also possible to set it as the structure by which the clearance gap where the inner wall of the said frame and the said laminated body oppose is sealed with the filler.

  In the sound generator of the present invention, the airtightness of the facing region between the display device and the protective panel can be improved. Therefore, even if the protective panel vibrates and the expansion and compression of the atmospheric pressure are repeated in the facing area, the air in and out of the facing area can be blocked. Therefore, it is possible to prevent a decrease in sound pressure level.

  FIG. 1 is a plan view showing an electronic apparatus equipped with a panel speaker as a first embodiment of a sound generator of the present invention, FIG. 2 is a cross-sectional view taken along line 2-2 of FIG. 1, and FIG. FIG. 4 is a perspective view showing a vibration generating means.

  An electronic device 10A shown in FIG. 1 is a display of a computer, for example, and an opening 12 having a square shape is formed on the front surface of a housing 11. A protective panel 20 having a larger area than the opening 12 is provided on the lower surface of the edge of the opening 12 and closes the opening 12 from the inside of the housing 11. The protective panel 20 is made of a synthetic resin plate such as transparent polycarbonate, acrylic, or polyethylene terephthalate (PET).

  As shown in FIG. 2, the periphery of the protective panel 20 is surrounded by a packing member 21, and the protective panel 20 is fixed to the bottom surface of the edge of the opening 12 via the packing member 21. The packing member 21 fills a gap between the bottom surface of the edge of the opening 12 and the top surface of the edge of the protective panel 20, and is preferably a member that is soft enough not to impede vibration in the protective panel 20. In some cases, it may be omitted.

  As shown in FIG. 1, vibration generating means 3 (individually referred to as 3A and 3B) are provided on the lower surface side of the protective panel 20 and in the vicinity of both side edges in the X1 and X2 directions shown in the figure.

  As shown in FIG. 4, the vibration generating means 3 is formed of a support member 5, a magnet M, a yoke 6, and a coil C. The support member 5 is formed of a magnetic material such as a steel plate, and is formed with connecting portions 5a and 5a bent in an L shape at both ends in the vertical direction, and on both side portions extending in the vertical direction. Bent portions 5b and 5b are formed. The connecting portions 5a and 5a of the support member 5 are fixed to the lower surface of the protective panel 20 with an adhesive or the like. As shown in FIG. 3, the end surfaces of the bent portions 5 b and 5 b of the support member 5 face each other in a state where they do not hit the diaphragm 2.

  As shown in FIG. 3, the magnet M is formed of a permanent magnet such as ferrite or rare earth, and is fixed to the bottom 5 c of the support member 5 facing the protective panel 20. The yoke 6 is made of a magnetic material having the same area as the upper surface of the magnet M, and is fixed in a state of being overlaid on the magnet M. Note that the yoke 6 and the magnet M are formed in thickness dimensions so that the yoke 6 does not contact the protective panel 20 when they are overlapped with each other.

  On the other hand, the coil C is provided on the lower surface of the protective panel 20 at a position facing the support member 5. The coil C is wound in a rectangular frame shape with a coated copper wire or the like and is elongated in the vertical direction, and is fixed to the lower surface of the protective panel 20 with an adhesive or the like.

  When the support member 5 is fixed to the lower surface of the protection panel 20, the magnet M and the yoke 6 are inserted so as to be positioned in the coil C. At this time, gaps G and G with very small gaps are formed between the bent portions 5b and 5b of the support member 5 and the magnet M and the yoke 6, and the coil C is located in the gaps G and G. Yes. That is, the bent portions 5b and 5b function as opposing yokes.

  As shown in FIG. 3, when the Z1 side of the magnet M is magnetized to the N pole and the Z2 side is magnetized to the S pole, the magnetic flux generated by the magnet M is bent by the yoke 6, the gap G, and the support member 5. It passes through a magnetic path formed in the order of the part 5b and the bottom part 5c. Therefore, as shown in FIG. 3, by applying a current orthogonal to the magnetic flux passing through the gap G in the forward and reverse directions, electromagnetic forces in the Z1 and Z2 directions act on the coil C. Due to this electromagnetic force, the protection panel 20 is vibrated in the Z direction together with the coil C, so that a sound based on the current is generated from the protection panel 20.

  The vibration generating means 3 is not limited to a driving means using magnetism, and a piezoelectric element is bonded to the protective panel 20, and the protective panel 20 is vibrated according to the distortion of the piezoelectric element. Good. In the above description, the movable coil type vibration generating means 3 is shown. However, a movable magnet type in which a magnet and a yoke are provided on the protective panel 20 side and a coil is provided on the support member 5 side may be used.

  As shown in FIG. 1, a display device 30 is provided on the bottom surface of the housing 11. The display device 30 is formed of a display laminate in which a plurality of members are laminated. For example, a deflection filter is provided in the lowermost layer, and a first glass substrate, an X-direction transparent electrode layer, An alignment layer, a liquid crystal, a second alignment layer, a Y-direction transparent electrode layer, a color filter, a second glass substrate, and the like are laminated in this order, and a second deflection filter (deflection plate) 31 is provided on the uppermost layer. Are stacked.

  The display device 30 is unitized by housing the display laminate in a frame 32. An opening 34 having the same size as the opening 12 of the housing 11 is formed inside the upper end 33 of the frame 32. Only the second deflection filter 31 provided in the uppermost layer is exposed in the opening 34. The upper end portion 33 of the frame 32 and the surface of the second deflection filter 31 are formed in substantially the same plane, and the opening 34 is filled with the deflection filter 31.

  However, a slight gap g is also formed between the display laminated body and the frame 32, and in the following, formed between the inner edge of the opening 34 and the edge of the second deflection filter 31. G1 is the gap between the end of each layer forming the display laminate and the inner wall of the frame 32, and the surface of the second deflection filter 31 and the upper end 33 of the frame 32. A gap formed between the lower surface of the second deflection filter 31 and the surface of the second deflection filter 31 will be described as g2.

  As shown in FIG. 2, a holding frame 41 is provided on the upper surface of the upper end portion 33 of the frame body 32 and the end portion of the second deflection filter 31 for one turn along the edge of the opening 34. ing. A square frame-shaped sealing member 42 is provided between the holding frame 41 and the lower surface side of the protective panel 20. The sealing member 42 is formed of an elastic member such as silicon rubber, and is provided between the protective panel 20 and the display member 30 in a state where the height direction is compressed. Due to the elastic force of the sealing member 42, the peripheral edge portion of the protective panel 20 is elastically supported in a state where it is pressed against the bottom surface of the edge portion of the opening 12 via the packing member 21. Similarly, the holding frame 41 is pressed against both the upper end portion 33 of the frame body 32 and the surface of the second deflection filter 31 by the elastic force of the sealing member 42. The four side surfaces in the X and Y directions are surrounded by the sealing member 42, so that a cavity Q1 is formed in a region where the protective panel 20 and the display device 30 face each other. In other words, the sealing member 42 also has a function of blocking the entry and exit of air between the external space and the cavity Q1.

  In the first embodiment, as shown in FIG. 3, a sealing member S is interposed on the lower surface of the holding frame 41, and the inner edge of the opening 34 and the edge of the second deflection filter 31 are The gap g1 formed between the two is closed over the entire circumference. That is, by covering the gap g1 from the outside of the frame 32 with the sealing member S, the cavity Q1 and the gap g2 formed inside the frame 32 are blocked. Therefore, the entrance and exit of air through the gap g1 is prevented, and a highly airtight cavity Q1 is formed.

  The sealing member S is preferably, for example, a film sheet having a stretch property in the film thickness direction, a rubber sheet, or a double-sided adhesive tape in which an adhesive layer is formed on both sides of the film.

  A video signal is sent to the electronic device 10A, and this is controlled by a driver control means (not shown) and applied to the display device 30, whereby a video is displayed on the display device 30. As shown in FIG. 1, a backlight BL composed of a fluorescent lamp or the like is provided at the end in the Y direction in the housing 11, and this image is viewed from the outside through the protective panel 20. be able to.

  Further, when an audio signal is given to the vibration generating means 3A, 3B of the electronic device 10A, the protection panel 20 vibrates in response to the audio signal, so that a sound is emitted from the protection panel 20. At this time, when the audio signals given to the vibration generating means 3A and 3B are the same signal, they function as a monaural speaker, and when they are different audio signals, they function as a stereo speaker.

  In other words, the electronic device 10A can simultaneously view the video and audio through the protective panel 20.

  In addition, since the cavity Q1 is highly airtight as described above, even if the protective panel (vibrating plate) vibrates and the expansion and compression of the atmospheric pressure are repeated in the cavity Q1, the inside of the cavity Q1 and the outside are at this time. It is possible to block the entry and exit of air. Therefore, it is possible to prevent a decrease in sound pressure level (SPL).

FIG. 5 is a partial cross-sectional view similar to FIG. 3, showing a second embodiment of the present invention.
In the electronic device 10B shown in FIG. 5, a recess 13 is formed in the housing 11, an opening 14 is formed at the center of the recess 13, and a support formed inside the recess 13 and around the opening 14. Although different from the first embodiment in that the protective panel 20 is fixed to the upper surface of the portion 15, the other configurations are the same as in the above case.

  In this electronic apparatus 10B, the peripheral edge of the protective panel 20 is fixed via a square frame-shaped sealing member 42 as in the first embodiment. A first sealing member S1 similar to that of the first embodiment is provided between the sealing member 42 and the upper surface of the support portion 15.

  On the other hand, the display device 30 has the same configuration as that of the first embodiment, and the upper end portion 33 of the frame body 32 covering the display laminated body and the edge portion of the second deflection filter 31 are formed on the support portion 15. It is fixed to the lower surface. A second sealing member S <b> 2 is interposed between the upper end portion 33 of the frame body 32 and the surface of the second deflection filter 31 and the lower surface of the support portion 15.

  That is, also in the second embodiment, in the region where the protective panel 20 and the display device 30 face each other, the four side surfaces in the X and Y directions are blocked by the sealing member 42 and the support portion 15. A cavity Q2 is formed.

  In the second embodiment, as shown in FIG. 5, the second sealing member S <b> 2 provided on the lower surface of the support portion 15 connects the edge of the opening 14 and the second deflection filter 31. The gap g1 formed between the edges is closed over the entire circumference. Therefore, the entry and exit of air between the cavity Q1 and the gap g2 formed inside the frame body 32 is blocked. In addition, the first sealing member S1 blocks air in and out between the cavity Q2 and the outside of the housing 11.

  Therefore, also in the electronic device 10B of the second embodiment, a highly airtight cavity Q2 is realized, and the protective panel (vibrating plate) 20 vibrates and the expansion and compression of atmospheric pressure are repeated in the cavity Q2. However, at this time, since the entrance and exit of air between the inside and outside of the cavity Q2 can be blocked, it is possible to prevent the sound pressure level from being lowered.

  FIG. 6 is a graph showing comparison of frequency characteristics of sound pressure level (SPL) between the present embodiment and the conventional embodiment. In FIG. 6, a dotted line indicates a conventional form as a comparative example, and a solid line indicates the present embodiment.

  As shown in FIG. 6, it can be seen that the present embodiment can generally prevent the sound pressure level from lowering compared to the conventional example.

The sound pressure level L _P is defined as 10 times the common logarithm of the value obtained by dividing the square of the sound pressure effective value p [Pa] by the square of the reference sound pressure p ₀ [20 μPa], Given by 1. The unit is decibel [dB].

  In each of the above embodiments, the gap g1 is blocked by the sheet-like or tape-like sealing member S, thereby blocking the cavities Q1 and Q2 and the gap g2 in the frame 32. For example, the gap g1 and the gap g2 themselves may be filled with a sealing member made of a filler.

The top view which shows the electronic device carrying the panel speaker as 1st Embodiment of the acoustic generator of this invention, Sectional drawing in the 2-2 line of FIG. Partial sectional view showing the main part of the electronic device, The perspective view which shows a vibration generation means, The fragmentary sectional view similar to FIG. 3 which shows the 2nd Embodiment of this invention, A graph showing a comparison of frequency characteristics of sound pressure level (SPL) in the present embodiment and the conventional embodiment,

Explanation of symbols

3, 3A, 3B Vibration generating means 10A, 10B Electronic device 11 Housing 14, 34 Opening 15 Support portion 20 Protection panel 21 Packing member 30 Display device 31 Deflection filter (uppermost layer member)
32 Frame 41 Holding frame 42 Sealing member Q1, Q2 Cavity (opposite area between display device and protective panel)
C Coil g1 Gap g2 Gap M Magnets S, S1, S2 Sealing member

Claims (4)

A display device in which a laminate composed of a plurality of layers is housed in a frame and only a member of the uppermost layer of the laminate is exposed to the outside of the frame, a protection panel disposed opposite to the display device, A sealing member that elastically supports the protective panel with respect to the display device and blocks a facing region formed between the display device and the protective panel from an external space, and provides vibration to the protective panel to generate sound. A sound generating device having vibration generating means for generating
A sealing member that blocks an air flow between the gap and the facing region by sealing a gap formed between the inner wall of the frame and the laminated body. The sound generator characterized by being provided.   The sound generation device according to claim 1, wherein the sealing member covers a gap formed between an inner edge portion of the frame body and an edge portion of an uppermost layer member of the laminated body from the outside of the frame body. .   2. The sealing member is any one of a film sheet having a stretch property in a film thickness direction, a rubber sheet, or a double-sided adhesive tape in which these are formed in a tape shape and an adhesive layer is formed on both surfaces thereof. Or the acoustic generator of 2.   The sound generator according to claim 1 or 2, wherein a gap between the inner wall of the frame and the laminated body is sealed with a filler.

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