JP2006337523A - Liquid crystal display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal display device capable of preventing generation of warping so as to be attached, while using a flat plate for a protective panel. <P>SOLUTION: A spacer 4 is interposed annularly between the surface near the periphery of a liquid crystal panel 2 and the protective panel 3, and a warping regulating member 5 is provided annularly between the protective panel 3 and a chassis 1, at a position outside the spacer 4. The warping regulating member 5 prevents displacement of a part of the protective panel 3 outside the spacer 4, in a direction of separating from the liquid crystal panel 2. Thus, the protective panel 3 is prevented from warping in the direction of approaching the liquid crystal panel 2. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a liquid crystal display device in which a protective panel is provided on the front surface of a liquid crystal panel.

  In recent years, liquid crystal display devices have become widespread, and they are often used not only in an upright state but also with a display surface facing upward or downward, taking advantage of the thin and lightweight features. Therefore, in order to protect the surface of the liquid crystal panel, a liquid crystal display device in which a protection panel is provided with a small gap along the surface of the liquid crystal panel has been put into practical use.

  Although a transparent resin plate is used for the protective panel, it is unavoidable that warping occurs due to the influence of temperature, humidity, weight, and the like. For example, when the liquid crystal display device is activated and the temperature of the liquid crystal panel rises, the inner surface temperature of the protective panel facing the liquid crystal panel becomes higher than the outer surface temperature that touches the outside air, and is protected by the difference in expansion caused by the temperature difference between the inner and outer surfaces. The panel is warped to bend toward the liquid crystal panel. In addition, when the outer surface of the protective panel is hard-coated to prevent scratches, the hygroscopic expansion of the uncoated inner surface is greater than the hygroscopic expansion of the outer surface, and the protective panel protrudes toward the liquid crystal panel. Warping to bend occurs. Further, when the display surface is used facing upward, the protective panel is bent and deformed toward the liquid crystal panel by its own weight. In either case, the protective panel warps in the direction of bending toward the liquid crystal panel, and the protective panel comes into contact with the display surface of the liquid crystal panel.

  In this way, in order to eliminate the trouble caused by the protection panel warping to the liquid crystal panel side, the protection panel is formed to be warped to the outer surface side, and this protection panel is straightened and deformed and attached to the flat state. A means has been proposed in which the protective panel is prevented from warping to the liquid crystal panel side due to internal stress generated by the correction deformation (see, for example, Patent Document 1).

JP 2004-151304 A

  In the above-mentioned means, the protective panel is previously formed into a warped shape that curves outwardly, or another curved process is applied to the protective panel formed on the flat plate, which increases the production cost of the protective panel Met.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a liquid crystal display device that can be mounted while suppressing the occurrence of warpage while using a flat plate for a protective panel.

In order to achieve such an object, the present invention has the following configuration.
That is, according to the first aspect of the present invention, in the liquid crystal display device in which the liquid crystal panel is accommodated in the housing and the protective panel is provided along the surface of the liquid crystal panel, the surface near the outer periphery of the liquid crystal panel and the surface An annular spacer is provided between the protective panel and the protective panel, and a warp restricting member is provided between the protective panel and the casing to support the protective panel over the entire circumference from the surface side at a position outside the spacer. It is characterized by being deployed.

  [Operation / Effect] When the protective panel tries to warp so as to approach the surface of the liquid crystal panel due to its own weight, temperature conditions, etc., the protective panel has the contact part with the spacer as a fulcrum and the outside is the protective panel surface side, that is, the liquid crystal panel Try to move away from the direction. However, according to the first aspect of the invention, the warp restricting member disposed at this position is received, and displacement in the direction away from the liquid crystal panel is prevented. At this time, the warpage restricting member applies a load to the protective panel at a position outside the spacer. This load is converted into a warping prevention force that counteracts the force of the protective panel to warp so as to approach the surface of the liquid crystal panel with the spacer as a fulcrum. As a result, the protection panel is prevented from warping in the direction approaching the liquid crystal panel.

  According to a second aspect of the present invention, in the liquid crystal display device according to the first aspect, an elastic material that elastically presses the surface of the protective panel is disposed outside the warpage regulating member. Is.

  [Operation / Effect] According to the invention described in claim 2, the elastic restoring force of the elastic material allows the outer peripheral edge of the protective panel to be appropriately pressed in a direction approaching the liquid crystal panel to approach the liquid crystal panel. Preloading can be performed with reverse characteristics against warping, and the warpage of the protective panel toward the liquid crystal panel is suppressed. Further, when a cause of occurrence of a large warp is applied to the protective panel, the warp regulating member functions as described above, and the warpage of the protective panel toward the liquid crystal panel is suppressed.

  According to a third aspect of the present invention, in the liquid crystal display device according to the second aspect, the protective panel pressing force by the elastic material is twice the protective panel's own weight ≧ the protective panel pressing force ≧ the protective panel's own weight. The range is set.

  [Operation / Effect] According to the invention described in claim 3, when the liquid crystal panel is used in a horizontal or close-up posture, the protective panel has a tendency that the central portion is concavely curved downward due to its own weight. However, the pressing force applied to the outer peripheral edge side of the protective panel by the elastic material cancels out the concave bending stress due to its own weight, and the protective panel is maintained in a flat state.

  When it tries to warp so as to approach the surface of the liquid crystal panel due to its own weight, temperature conditions, etc., the outer side of the protective panel is displaced in the direction away from the liquid crystal panel, with the contact point with the spacer as a fulcrum. try to. However, according to the liquid crystal display device of the present invention, it is received by the warp regulating member provided at this position, and displacement in the direction away from the liquid crystal panel is prevented. At this time, the warpage restricting member applies a load to the protective panel at a position outside the spacer. This load is converted into a warping prevention force that counteracts the force of the protective panel to warp so as to approach the surface of the liquid crystal panel with the spacer as a fulcrum. As a result, the protection panel is prevented from warping in the direction approaching the liquid crystal panel. Therefore, it is possible to provide a liquid crystal display device that can be mounted while suppressing the occurrence of warping while using a flat plate for the protective panel.

Embodiment 1 of the present invention will be described below with reference to the drawings.
1 is a cross-sectional view illustrating a liquid crystal display device according to a first embodiment, FIG. 2 is a cross-sectional view taken along the line aa in FIG. 1, and FIG. 3 is an exploded perspective view illustrating the liquid crystal display device.

  As shown in FIGS. 1 to 3, this liquid crystal display device is illustrated in which a liquid crystal panel 2 is accommodated in a resin casing 1 having a large front opening in a rectangular shape so as to face the opening. A protective panel 3 made of a transparent resin flat plate is provided on the surface of the liquid crystal panel 2 and fixed by no connecting means.

  Between the liquid crystal panel 2 and the protective panel 3, a spacer 4 is arranged in a rectangular ring around a display area (not shown) of the liquid crystal panel 2, and a predetermined small gap is formed between the panels 2 and 3. Has been. In this embodiment, a hard rubber material is used as the spacer 4.

  Further, a warp regulating member 5 is arranged in a rectangular ring shape outside the spacer 4 between the front wall portion 1 a and the protective panel 3 in the housing 1. In the present embodiment, a hard rubber material is also used for the warp regulating member 5. In this example, the spacer 4 and the warp restricting member 5 are configured by arranging linearly cut dimensions in a rectangular ring shape, but may be formed integrally in a series of rectangular ring shapes.

  With the above configuration, when the liquid crystal display device is operated, heat generated from the liquid crystal panel 2 or the like is directly transmitted to the surface of the protective panel 3 on the liquid crystal panel 2 side (hereinafter referred to as “inner surface” as appropriate). . On the other hand, the surface opposite to the inner surface of the protective panel 3 (hereinafter referred to as “outer surface” as appropriate) is affected by the environment (temperature and humidity) around the liquid crystal display device.

  When the protection panel 3 tries to warp so as to approach the surface of the liquid crystal panel 2 due to an expansion difference or the like caused by a temperature difference between the inner and outer surfaces, a portion outside the spacer 4 of the protection panel 3 is a contact portion with the spacer 4. Is intended to be displaced in the direction away from the outer surface of the protective panel, that is, from the liquid crystal panel 2. At this time, the warpage restricting member 5 receives the protective panel 3 at a position outside the spacer 4, and displacement in a direction away from the liquid crystal panel 2 due to warpage of the protective panel 3 is prevented.

  The operation in which the warpage restricting member 5 prevents the protection panel 3 from being displaced can be considered that the warpage restricting member 5 applies a load to the protective panel 3 at a position outside the spacer 4. This load is converted into a warpage prevention force that counteracts the force of the protection panel 3 to warp so as to approach the surface of the liquid crystal panel 2 with the spacer 4 as a fulcrum. As a result, the protection panel 3 is prevented from warping in the direction approaching the liquid crystal panel 2.

Next, Embodiment 2 of the present invention will be described with reference to the drawings.
4 is a cross-sectional view illustrating a liquid crystal display device according to a second embodiment, FIG. 5 is a cross-sectional view taken along the line bb in FIG. 4, and FIG. 6 is an exploded view illustrating the liquid crystal display device according to the second embodiment. It is a perspective view. In addition, about the same structure as Example 1, detailed description is abbreviate | omitted by giving the same code | symbol.

  As shown in FIGS. 4 to 6, this liquid crystal display device is basically the same as that of the first embodiment. A protective panel 3 is provided on the surface of the liquid crystal panel 2 via a rectangular annular spacer 4, and is positioned on the outer peripheral side of the spacer 4 between the protective panel 3 and the front wall 1 a of the housing 1. A warp regulating member 5 is interposed. In the second embodiment, the elastic member 6 is provided outside the four corners of the warp regulating member 5.

  The thickness of the elastic member 6 is slightly larger than the thickness of the warp regulating member 5 and is elastically deformed and pressed to the outer periphery of the protective panel 3.

  According to the above configuration, the surface near the outer peripheral edge of the protective panel 3 is appropriately pressed against the liquid crystal panel 2 side by the elastic restoring force of the elastic member 6, thereby having a reverse characteristic to counter warpage in the direction approaching the liquid crystal panel 2. Preloading can be performed, and the warpage of the protective panel 3 toward the liquid crystal panel 2 is suppressed. Further, when a cause of occurrence of a large warp is applied to the protective panel 3, the warp regulating member 5 functions as described above, and the warpage of the protective panel 3 toward the liquid crystal panel 2 is suppressed.

In this case, the protective panel pressing force given by the elastic material 6 is
It is desirable to set the range of twice the weight of the protective panel 3 ≧ the pressure of the protective panel ≧ the weight of the protective panel 3.

  According to this configuration, when the liquid crystal panel 2 is used in a horizontal or close-up posture, the protective panel 3 tends to be concavely curved downward at its center due to its own weight. The pressing force applied to the outer peripheral portion of 3 and the concave bending stress due to its own weight are offset, and the protective panel is maintained in the flat state of 3.

  The present invention is not limited to the above-described embodiment, and can be modified as follows.

  (1) In each Example mentioned above, although the spacer 4 and the curvature control member 5 were the structures provided with the liquid crystal panel 2 or the protection panel 3, it is not restricted to this. For example, as shown in FIG. 7, the spacer 4 may be formed integrally with the liquid crystal panel 2, and the warpage restricting member 5 may be formed integrally with the front wall portion 1 a of the housing 1.

  (2) In each of the embodiments described above, the spacer 4 and the warp regulating member 5 are separate from each other, but the present invention is not limited to this. For example, as shown in FIG. 8, the spacer 4 and the warp regulating member 5 can be integrally formed.

  (3) In each of the embodiments described above, a hard rubber material is used as the warp regulating member 5, but the material is not particularly limited as long as it has a certain hard property such as plastic or metal.

  (4) In the second embodiment described above, the elastic material 6 is disposed outside the four corners of the warp regulating member 5, but the installation position of the elastic material 6 in the circumferential direction is not limited to the above example. For example, the pressurization may be applied not only to the four corners of the warp regulating member 5 but also to the intermediate portions of the four sides of the protection panel 3. Moreover, you may provide in cyclic | annular form so that the perimeter of the protection panel 3 may be pressurized.

  (5) In Example 2 mentioned above, although the curvature control member 5 and the elastic material 6 were separate bodies, it is not restricted to this. For example, as shown in FIG. 9, an elastically deformable tongue piece 5 a is integrally formed outside the four corners of the warp regulating member 5, and the tongue piece 5 a is applied to the end of the protective panel 3 with an elastic material 6. It is also possible to do.

1 is a cross-sectional view illustrating a liquid crystal display device according to Example 1. FIG. It is the sectional view on the aa line in FIG. 1 is an exploded perspective view showing a liquid crystal display device according to Embodiment 1. FIG. 6 is a cross-sectional view showing a liquid crystal display device according to Embodiment 2. FIG. It is the bb sectional view taken on the line in FIG. 6 is an exploded perspective view showing a liquid crystal display device according to Embodiment 2. FIG. It is sectional drawing which shows the principal part of the liquid crystal display device which concerns on a modification. It is sectional drawing which shows the principal part of the liquid crystal display device which concerns on a modification. Furthermore, it is the perspective view (a) and sectional drawing (b) which show the principal part of another Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Housing 2 ... Liquid crystal panel 3 ... Protection panel 4 ... Spacer 5 ... Warpage control member 6 ... Elastic material

Claims (3)

In a liquid crystal display device equipped with a housing that houses a liquid crystal panel and a protective panel provided along the surface of the liquid crystal panel,
While interposing a spacer annularly between the surface near the outer periphery of the liquid crystal panel and the protective panel,
A liquid crystal display device, wherein a warp regulating member for supporting the protective panel from the surface side over the entire circumference is provided annularly between the protective panel and the housing at a position outside the spacer. The liquid crystal display device according to claim 1.
A liquid crystal display device, wherein an elastic material that elastically presses the surface of the protective panel is disposed outside the warp regulating member. The liquid crystal display device according to claim 2,
The protective panel pressing force by the elastic material,
2. A liquid crystal display device characterized in that the range is set to double the protective panel's own weight ≧ protective panel pressing force ≧ protective panel's own weight.

Images