JP2013210509A - Image display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image display device capable of reducing display unevenness caused by a stress applied on a liquid crystal panel.SOLUTION: In a liquid crystal display device having a liquid crystal panel, a panel holder for holding the liquid crystal panel; the panel holder has a back face support member for supporting the liquid crystal panel from the back face thereof; and the back face support member is provided, at a part thereof, with a protruded portion whose thickness in a direction perpendicular to a display surface of the liquid crystal panel is larger than that of other portions thereof, in accordance with a form of distortion from a flat face of the liquid crystal display device.

Description

  The present invention relates to an image display device.

  With the recent thinning and lightening of display devices, the glass thickness used for liquid crystal panels for display devices has also been reduced. When supporting thin LCD panels in a vertical position, the external stress that the LCD panel receives from the holding member affects the orientation of the liquid crystals, causing display unevenness and affecting the display quality of images. May give. In the liquid crystal display device, a backlight is disposed on the opposite side (hereinafter, back surface) of the liquid crystal panel display surface (hereinafter, surface). The display unevenness is caused by the light from the backlight in a state where an image signal for full screen black display is input to the liquid crystal panel (in the case of a normally black liquid crystal panel, a voltage is not applied between a pair of opposing glass substrates). Appears as a leak. Due to this leakage light, black floating occurs in which the luminance of a partial area of the full-screen black display is increased, and as a result, it is observed as display unevenness.

  FIG. 5A is an exploded perspective view of a conventional liquid crystal display device, and FIG. 5B is a partial cross-sectional view of the conventional liquid crystal display device with a cross section perpendicular to the liquid crystal panel and perpendicular to the horizontal direction. As shown in FIG. 5A or FIG. 5B, a conventional liquid crystal display device 500 is supported by a panel holder 502 on the back surface of the liquid crystal panel 503 and a front frame 504 on the surface of the liquid crystal panel 503 facing the device. Keep the vertical posture in the installed state. Both the panel holder 502 and the front frame 504 are attached with elastic members 505 and cushion members 506 on the surfaces that contact the peripheral edge outside the image display area so as not to damage the liquid crystal panel 503, and the liquid crystal panel 503 can be moved with a slight gap. It is pinched as possible. For this reason, the panel holder 502 and the front frame 504 sandwich the liquid crystal panel 503 with a slight gap in the thickness direction and reduce external stress on the liquid crystal panel 503, thereby suppressing display unevenness.

  Further, the panel holder 502 is in contact with the end face of the liquid crystal panel 503 and supports its own weight. Since the end surface of the liquid crystal panel 503, which is the contact surface, is obtained by cutting a large mother glass substrate into several parts, it is not flat and burrs are generated, or the bonding boundary between a pair of glass substrates In some cases, the edge is exposed due to a shift in the surface. Therefore, although the liquid crystal panel 503 is movably sandwiched in the thickness direction, the contact surface between the end surface of the liquid crystal panel 503 and the panel holder 502 is caught, and the stress applied to the liquid crystal panel 503 is not released and is displayed. Unevenness may occur. For this reason, the prior art document 1 discloses a configuration in which the liquid crystal panel is pushed back to the surface side by releasing the stress caused by the engagement between the end face of the liquid crystal panel and the panel holder using the weight of the liquid crystal panel and the inclined surface of the panel holder.

JP 2010-204357 A

  However, since the prior art solution has a structure in which the inclined surface of the panel holder is provided below the elastic member on the opposite side of the liquid crystal panel display surface, it is difficult to narrow the frame of the liquid crystal display device. In addition, in a medium-sized or large-sized liquid crystal panel, the liquid crystal panel itself has a warp rather than a flat surface, so it is difficult to reliably push the liquid crystal panel back to the installation position, and the stress applied to the liquid crystal panel is released sufficiently. There was no case.

  Accordingly, an object of the present invention is to provide a liquid crystal display device capable of reducing display unevenness due to stress applied to the liquid crystal panel.

The present invention is an image display device having a display panel and a panel holder for holding the display panel,
The panel holder has a back support member that supports the display panel from the back.
According to the shape of the distortion from the plane of the display panel, a protruding portion having a thickness in a direction perpendicular to the display surface of the display panel larger than other portions is provided in a part of the back support member. An image display device.

  ADVANTAGE OF THE INVENTION According to this invention, the liquid crystal display device which can reduce the display nonuniformity resulting from the stress added to a liquid crystal panel is provided.

An exploded perspective view and a section perspective view of the first example of the present invention are shown. The warpage measurement result of the liquid crystal panel and the outline of the panel warp shape are shown. Sectional drawing in broken line KK of FIG. 2 and the modification of a 1st Example are shown. The exploded perspective view of a 1st example of the present invention, a section perspective view, and a sectional view are shown. The cross-sectional perspective view and sectional drawing of the liquid crystal display device of a prior art example are shown.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. The technical scope of the present invention is determined by the scope of the claims, and is not limited by the following individual embodiments. In addition, all combinations of features described in the embodiments are not necessarily essential to the present invention.

Example 1
An example of the first embodiment will be described with reference to FIGS. 1 and 3. FIG. 1A is an exploded perspective view of the first embodiment of the image display device of the present invention, and FIG. 1B is an enlarged perspective view of a cross section at a portion B in FIG.

  In FIG. 1A, a frame-shaped front frame 104 having an opening wider than the image display area is disposed on the surface side of the liquid crystal panel 103 which is a display panel. In the present embodiment, the front frame 104 is composed of four parts, that is, the long side front frames 104b and 104d and the short side front frames 104a and 104c. It may be. The front frame 104 is obtained by press-molding a thin plate of iron or aluminum having a thickness of about 0.8 to 1.0 (mm). Soft cushion members 105a and 105b having a thickness of about 0.1 to 1.0 (mm) and a thin Asker C hardness of about 10 to 30 are affixed to the inner surface facing the surface of the liquid crystal panel 103. The cushion member 105a is affixed to the short side front frames 104a and 104c, and the cushion member 105b is affixed to the long side front frames 104b and 104d. Between the cushion member 105 and the surface of the liquid crystal panel 103, 0.1 to 1 in the thickness direction (perpendicular to the display surface) is applied so that stress that causes display unevenness is not applied to the display surface of the liquid crystal panel 103. A clearance of about 0.0 (mm) is provided.

The liquid crystal panel 103 is held by panel holders 102a, 102b, 102c, and 102d. The panel holder is provided with a back support member 102g for supporting the liquid crystal panel 103 from the back, and a raised portion 102f is provided at a part of the back support member 102g. The back support member 102g is provided with an elastic member 101 over the raised portion 102f and other portions. As will be described later, the elastic member 101 supports the liquid crystal panel 103 from the back surface by at least partly contacting the back surface of the liquid crystal panel 103 when the liquid crystal display device is used. The panel holder is provided with a support portion 102e that is a lower end support member at a position that supports a side that is a lower end when the liquid crystal display device is used. In the present embodiment, a back support member 102g is provided along each side of the liquid crystal panel 103 so as to face the back of the frame-shaped region around the display region of the liquid crystal panel 103. Further, the raised portion 102f is located along the side of the liquid crystal panel 103 that comes into contact with the support portion 102e that is the lower end support member in the state where the liquid crystal display device is used, among the back surface support members 102g provided along the respective sides. The back support member 102g is provided. When the front frame 104d is arranged below the gravity direction, that is, when the liquid crystal panel 103 is installed in the vertical direction, the lower end of the liquid crystal panel 103 is supported by the support portion 102e of the panel holder 102d. At least two support portions 102e are provided on the panel holder 102d at a sufficient interval so as to contact and stably support the lower end of the liquid crystal panel 103. The interval at which the support portion 102e is provided is determined in consideration of the warped shape of the liquid crystal panel 103 and the installation location of a liquid crystal sealing port (not shown).

  Further, an elastic member 101 is attached to a surface of the four-side panel holder 102 facing the back surface of the liquid crystal panel 103 so as to extend along the extending direction of the panel holder 102. Of the affixing surface of the panel holder 102d, a protuberance 102f is provided in the vicinity of the support 102e, and the pressing force for releasing the catch of the liquid crystal panel 103 by the elastic force of the elastic member 101 affixed along the protuberance 102f. Works. This elastic force suppresses the lower end of the liquid crystal panel 103 from being hooked by the support portion 102e, and the liquid crystal panel 103 is pushed back to the original shape (so that the deformation caused by the hook is eliminated).

The thickness and length of the elastic member 101 will be described below. When the weight of the liquid crystal panel is about 1.3 (kgf) and the coefficient of static friction between the liquid crystal panel 103 and the panel holder 102d is 0.25, the force required to push the panel back in the horizontal direction is obtained as follows. It is done.

1.3 × 0.25 = 0.325 (kgf) (1)

Next, the pressing force per unit area obtained by compressing about 0.3 (mm) which is 15% of the width 3 (mm) and the thickness 2 (mm) of the elastic member 101 is about 1. 4 × 10 −3 (kg / mm 2). When the length of the raised portions 102f provided in at least two places in the extending direction of the panel holder 102d is W (mm), the value obtained by the expression (1) is used.

0.325 = (1.4 × 10 −3 × 3 × W) × 2
W = 38.6 (mm) (2)

Is obtained. That is, the raised portion 102f has a length W of about 40 (mm) and may be provided in at least two panel holders 102d. Although not shown here, the liquid crystal panel 103 is pushed back by using a thick elastic member only in a part corresponding to the raised portion 102f or by separately providing a thick elastic member on the raised portion 102f. It is possible to gain power.

  However, in the case of the former, it is difficult to produce and position an elastic member having a partially different thickness, and in the latter case, the number of parts increases, whereas in this embodiment, the thickness of the elastic member 101 is It is advantageous in that it is uniform and easy to manufacture, and the number of parts does not increase.

  FIG. 2 shows an example of a warpage measurement result of the liquid crystal panel 103 of FIG. As the measuring method, a method of scanning each point a to n on the display surface of the liquid crystal panel 103 with a three-dimensional measuring device can be exemplified. Alternatively, a method of measuring by inserting a gap gauge between the front frame 104 and the surface of the liquid crystal panel 103 on the assumption that the flatness of the front frame 104 is maintained may be used.

  2B and 2D, the positions of the points a to e and h to l on the display surface of FIG. 2A are measured on the horizontal axis and the thickness direction of the liquid crystal panel 103 corresponding to the points is measured. Values are shown as the vertical axis. 2C and 2D, the positions of the points e to h and l to a on the display surface of FIG. 2A are measured on the vertical axis, and the thickness direction of the liquid crystal panel 103 corresponding to the points is measured. Values are shown on the horizontal axis.

  FIG. 2F is a conceptual diagram of a panel warp shape reflecting the measurement results of FIGS. 2B, 2C, 2D, and 2E. FIG. 2F is a diagram conceptually showing the warp of the liquid crystal panel in an easy-to-understand manner, and is not a diagram in which the actual amount of deformation is accurately scaled. As can be seen from FIG. 2F, the long side of the liquid crystal panel 103 has an arc shape that is recessed toward the back side when viewed from the display surface side, and the arc shape that is convex toward the near side when viewed from the display surface on the short side side. It can be seen that Here, the distance between the line segment ae connecting the point a and the point e and the long side arc portion vertex is h1, and the distance between the line segment eh connecting the point e and the point h and the short side arc portion vertex is h2. To do.

  As shown in FIG. 2F, the liquid crystal panel 103 has a three-dimensional curved surface whose plane is deformed. In this embodiment, a numerical value expressing the spatial distance between planes when the liquid crystal panel 103 is sandwiched between parallel planes in mm units is defined as “flatness”. In the case of FIG. 2F, the flatness of the liquid crystal panel 103 = (h1 + h2).

  3A is a cross-sectional view of the panel holder 102 and the elastic member 101 taken along the broken line KK in FIG. 2A, and points a to e of the liquid crystal panel 103 shown in FIG. 2B. The graph which shows the measured value of the position of the thickness direction of this, and what overlapped are shown. As shown in FIG. 3A, the protruding portion 102f that does not hinder the warping of the liquid crystal panel 103 has the length W of the protruding portion 102f and the height H of the protruding portion at the position X = ± X1. As an example of those values, when the amount of warpage on the long side of the liquid crystal panel 103 is h1≈0.5 (mm), the height H = 0.3 (mm) of the raised portion 102f is obtained from the measured value. In summary, a length W = 40 (mm) and a height H = 0.3 (mm) were obtained as an example of the raised portion 102f as described above.

  3B, 3C, and 3D show examples of other shapes of the raised portion 102f shown in FIG. In FIG. 3 (B), the raised portion 300f has a generally arcuate convex shape, in FIG. 3 (C), the raised portion 302f has a trapezoidal shape, but has a convex shape with an R on the shoulder, and in FIG. The portion 304f has a wave shape including a plurality of continuous triangular convex portions.

(Example 2)
An example of the second embodiment will be described with reference to FIG. FIG. 4A shows an elastic member 401 arranged in a “b” shape at the peripheral edge of the back surface of the liquid crystal panel 103 when viewed through the liquid crystal panel 103, and the outer periphery of the liquid crystal panel 103 more than that. A dustproof cushion member 402 disposed so as to surround the elastic member 401 at a position close to the side is shown. FIG. 4B is a cross-sectional perspective view taken along the broken line LL in FIG. FIG. 4C is a cross-sectional view taken along a plane perpendicular to the screen of the liquid crystal display device of this embodiment in which the liquid crystal panel 103 is supported by the elastic member 401 and the cushion member 402 for dust prevention is further provided.

4A, a short-side elastic member 401a and a long-side elastic member 401b that support the liquid crystal panel 103 from the back side are attached with a double-sided tape or the like along the extending direction of the panel holder 400 and the raised portion 400f. In this embodiment, the raised portions 400f are provided at two locations on the panel holder 400 on the lower side in the direction of gravity. Further, the short side cushion member 402a and the long side cushion member 402b are disposed so as to surround the outside of the short side elastic member 401a and the long side elastic member 401b. The respective thickness relationships are as follows: the total thickness of the raised portion 400f and the long side elastic member 401b is h3, and the uncompressed thickness of the short side cushion member 402a and the long side cushion member 402b is h4.

h3 <h4 (3)

Each dimension may be determined in such a relationship as follows. As an example of the thickness dimension, h3 = 2.3 to 2.5 (mm) and h4 = 3.0 to 4.0 (mm) are preferable from the viewpoint of improving dust resistance and reducing display unevenness of the liquid crystal panel 103. is there. Next, the relationship between each compression load is

(Compression load of elastic member 401b) >> (Compression load of cushion member 402b) (4)

It is good to select the material which becomes. As an example of compressive load,

(25% compression load of elastic member 401b) = 10 (kg / cm 2)
(25% compression load of the cushion member 402b) = 0.02 (kg / cm 2)

The degree is preferred.

  By selecting the values of the formulas (3) and (4), the thickness of the short side cushion member 402a and the long side cushion member 402b is compressed to about h3, and the liquid crystal panel is protected from dust without applying external stress. Performance can be increased.

  Due to the parallel arrangement structure of the elastic member 401 and the cushion member 402 as described above, as shown in FIG. 4C, the dust 403 is dammed and the effect of preventing the display defect of the liquid crystal panel 103 is obtained. That is, even if the dust 403 enters from the gap between the liquid crystal panel 103 and the front frame 104b or between the components around the drive circuit board 103b, the cushion member 402b blocks the dust 403.

  In the second embodiment, the configuration in which the raised portion is not formed in the portion corresponding to the position of the raised portion 400f in the portion where the cushion member 402 is provided in the panel holder 400 is illustrated. However, a raised portion similar to the raised portion 400f may be formed at a portion corresponding to the position of the raised portion 400f. In that case, the cushion member 402 is also raised at a position corresponding to the raised portion 400f.

  In the above embodiment, the case where the distortion of the side of the liquid crystal panel that contacts the lower end support member in the use state of the liquid crystal display device is such that the outer side of the liquid crystal panel is separated from the back support member is described as an example. . Therefore, an example in which two raised portions are provided at positions close to the outer peripheral portion of the liquid crystal panel has been described. However, the liquid crystal display device has a structure in which a raised portion whose thickness in the direction perpendicular to the display surface of the liquid crystal panel is larger than that of the other portion is provided on a part of the back support member in accordance with the shape of the distortion from the plane of the liquid crystal panel. If there is, it is included in the present invention. For example, if the distortion shape of the liquid crystal panel shown in FIG. 2B is convex upward, the distortion amount at points a and e is 0, and the distortion amount at point c is h1, the back support member 102g. The raised portion 102f is provided at the site corresponding to the point c.

Further, in the above-described embodiment, the example in which the raised portion 102f is provided on the back support member 102g provided along the side of the liquid crystal panel in contact with the lower end support member 102e has been described. This is to eliminate it more effectively. The position where the back support member 102g is provided is not limited to the position facing the back of the frame-shaped area around the display area of the liquid crystal panel 103 as in the above-described embodiment. Further, the back support member g provided with the raised portions is not necessarily limited to the back support member 102g provided along the side of the liquid crystal panel in contact with the lower end support member 102e.

101 Elastic member 102a, 102b, 102c, 102d Panel holder 102e Support part 102f Raised part 103 Liquid crystal panel

Claims (12)

An image display device having a display panel and a panel holder for holding the display panel,
The panel holder has a back support member that supports the display panel from the back.
According to the shape of the distortion from the plane of the display panel, a protruding portion having a thickness in a direction perpendicular to the display surface of the display panel larger than other portions is provided in a part of the back support member. An image display device. The position where the raised portion is provided is determined based on a position where the display panel is distorted in a direction away from the back support member,
The image display device according to claim 1, wherein the thickness of the raised portion is determined based on an amount of distortion in a direction perpendicular to the display surface of the display panel. The panel holder has a lower end support member provided at a position that supports a lower side of the display panel in a state where the image display device is used,
3. The image display device according to claim 1, wherein the back support member is provided along a side of the side of the display panel that contacts the lower end support member in a state where the image display device is used. The panel holder has a lower end support member provided at a position that supports a lower side of the display panel in a state where the image display device is used,
The image display device according to claim 1, wherein the back support member is provided along each side of the display panel so as to face a back surface of a frame-like region around a display region of the display panel.   The image according to claim 4, wherein the raised portion is provided on a portion of the back support member that is provided along a side of the display panel that comes into contact with the lower end support member in a state where the image display device is used. Display device.   The back support member is an elastic member that supports the display panel from the back surface by at least partly contacting the back surface of the display panel in a state where the image display device is used across the raised portion and other portions. The image display device according to claim 1, wherein the image display device is provided.   The image display device according to claim 6, wherein the elastic member has a uniform thickness in a direction perpendicular to a display surface of the display panel.   8. The image display device according to claim 6, wherein the back support member is provided with a dustproof cushion member in parallel with the elastic member at a position closer to the outer peripheral side of the display panel than the elastic member. .   The image display device according to claim 8, wherein a compression load of the elastic member is larger than a compression load of the cushion member.   The image display device according to claim 8, wherein a thickness of the elastic member in a direction perpendicular to a display surface of the display panel is smaller than a thickness of the cushion member.   11. The image display device according to claim 8, wherein a protruding portion is formed at a position corresponding to the protruding portion at a portion of the back support member where the cushion member is provided.   The image display device according to any one of claims 8 to 10, wherein a protruding portion is not formed at a portion of the back support member where the cushion member is provided.

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