JP2008090094A - Backlight device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To cause neither generation of a vibration sound from a lock hole of a diffusion plate of a backlight device nor rubbing even in a vibration environment, to eliminate damage to an optical sheet, and to adapt the backlight device to thermal expansion of the diffusion plate. <P>SOLUTION: The backlight device wherein while a fluorescent tube 3 as a light source is disposed in a shallow-bottom box-shaped housing 1 supported in a vertical direction, projections 6 to 8 are formed above the front of the housing 1 on the same horizontal straight line and the diffusion plate 4 is locked to the projections 6 to 8 is characterized in that a center lock hole 17 among lock holes 16 to 18 formed in the diffusion plate 4 is made nearly equal in lateral width to the projection 7 inserted into the lock hole 17, and the left and right lock holes 16 and 18 are made larger in lateral width than the projections 6 and 8 inserted into the lock holes 16 and 18. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a backlight device used as a light source for a liquid crystal television or the like, and more particularly, to a support structure in which a diffusion plate constituting the backlight device is locked to a protrusion protruding from a rear chassis, and the engagement formed on the diffusion plate. The present invention relates to a backlight device that eliminates vibration noise and fine powder due to rusting that are generated due to backlash of a locking hole in a vibration environment by reducing backlash of a stophole.

  Conventionally, a backlight device used for a liquid crystal display device such as a liquid crystal television has a diffusion plate made of an acrylic plate or the like disposed in front of a fluorescent lamp as a light source, and an ITO sheet, a diffusion film, a prism sheet, a reflective polarizing film in front of the diffusion plate. An optical sheet such as is arranged. In particular, when the irradiation surface of the backlight device is supported vertically, protrusions are projected at two or three positions on the abutting surface of the rear chassis where the upper end of the diffuser plate abuts, and the upper end is similarly formed. The diffuser plate and the optical sheet in which the holes were formed were locked to the projections, and the diffuser plate and the optical sheet were held suspended by their own weight.

As an example, there is a backlight device described in Patent Document 1. In this backlight device, the locking hole formed in the diffusion plate is formed to have a size that is more playful than the projection to be locked. By providing this play, the backlight device is turned on, the ambient temperature around the diffusion plate rises, and even if the diffusion plate expands relative to the rear chassis, it contacts the projections that are locked. It is possible to avoid excessive load from coming into contact, and the diffusion plate can freely expand and contract.
JP 2003-215585 A

  However, as described above, if sufficient play is provided in the locking hole of the diffusion plate to which the protrusion is locked, the protrusion repeatedly contacts the inner wall of the locking hole of the diffusion plate in a vibration environment such as during transportation. This causes problems such as vibration noise, white powder generated from the diffuser plate due to cosmetics, and scattering around it, or scratching the optical sheet placed in front of the diffuser plate. was there. Therefore, the present invention does not generate vibration noise or blur from the locking holes of the diffusion plate even in a vibration environment, does not damage the optical sheet, and further does not cause thermal expansion of the diffusion plate. An object of the present invention is to propose a backlight device having a diffusion plate locking hole which can be used.

  In order to solve the above-mentioned problems, the present invention has a light source disposed inside a shallow box-shaped housing supported in a vertical direction, and two or more protrusions projecting from the front upper portion of the housing. In the backlight device in which the diffusing plate is locked to the protrusion, one of the two or more locking holes formed in the diffusing plate has a lateral width substantially the same as the lateral width of the protrusion, and The lateral width of the stop hole is made larger than the lateral width of the protrusion.

  Specifically, a light source is arranged inside a shallow box-shaped housing supported in a vertical direction, and two or more protrusions are provided on the front upper portion of the housing on the same horizontal line so as to project the protrusions. In the backlight device in which the diffusion plate is locked, the horizontal width of one of the two or more locking holes formed in the diffusion plate is made substantially the same as the horizontal width of the protrusion inserted through the locking hole. The lateral widths of the other locking holes are made larger than the lateral widths of the protrusions inserted into the locking holes. Here, it is preferable that the height of each of the locking holes is substantially the same as the height of each of the protrusions inserted into the locking holes.

  As described above, according to the present invention, the lateral width of one of the two or more locking holes formed in the diffusion plate is made substantially the same as the lateral width of the projection, and the lateral width of the other locking holes is projected. Because it is larger than the width of the, the diffuser plate is locked to the protrusion, so there is no play, so it is possible to eliminate scratches and scrapes and damage the optical sheet even if vibration is applied, Even if the diffusion plate is heated and heated while the backlight device is turned on, the expansion is absorbed by the portion of the locking hole wider than the lateral width of the protrusion, and there is no problem.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows an embodiment of a backlight device according to the present invention, FIG. 1 (a) is a longitudinal side view, and FIG. 1 (b) is a front view showing an engaged state of a diffusion plate in FIG. 1 (a). FIG. 2 is an exploded perspective view showing engagement of the diffusion plate in the backlight device shown in FIG. In FIG. 1, reference numeral 1 denotes a shallow box-shaped housing, a reflecting plate 2 is attached to the inside thereof, and a plurality of fluorescent tubes 3 as light sources are arranged at equal intervals in front of the reflecting plate 2. . On the front surface of the outer periphery of the housing 1, an abutting recess 5 with which the diffusion plate 4 abuts is formed.

  On the upper part of the contact recess 5, protrusions 6 to 8 having a rectangular cross section and having the same dimensions are provided at the left end, the center, and the right end. Locking holes 16 to 18 are formed in the upper end portion of the diffusion plate 4 corresponding to the protrusions 6 to 8. The locking hole 17 with which the central protrusion 7 is engaged is formed in a rectangular shape having a slight gap between the left and right sides and the lower side when the protrusion 7 is engaged. The locking hole 16 with which the left end protrusion 6 is engaged is formed in a rectangular shape having a slight gap on the left and lower sides and a slightly larger gap on the right side when the protrusion 6 is engaged. Yes. Similarly, the locking hole 18 with which the right end protrusion 8 is engaged has a rectangular shape with a slight gap on the right and lower sides and a slightly larger gap on the left side with the protrusion 8 engaged. Is formed.

  Further, although not shown, the three optical sheets 9 that are locked to the protrusions 6 to 8 next to the diffusion plate 4 are also formed with locking holes at the upper ends, as in the case of the diffusion plate 4. The diffusing plate 4 is assembled by inserting the locking holes 16 to 18 into the protrusions 6 to 8 while first engaging the central locking hole 17 with the protrusion 7 at the time of assembly. Next, the optical sheet 9 is incorporated in the same procedure. In the diffuser plate 4 assembled in this way, the locking hole 17 is substantially free from play in both the vertical and horizontal directions with respect to the central protrusion 7, so that no play is generated. The looseness, scratches, etc. caused by looseness that occurred in

  Further, in the backlight device configured as described above, when the fluorescent tube 3 is turned on to generate heat and the air temperature around the diffusion plate 4 rises, the diffusion plate 4 also starts thermal expansion. At this time, since the diffusion plate 4 is positioned by the central locking hole 17, the left and right locking holes 16, 18 expand so as to move in the left direction and the right direction, respectively. Here, the locking hole 16 that moves to the left has a margin on the right side of the projection 6, and the locking hole 18 that moves to the right has a margin on the left side of the projection 8. It is avoided that the holes 16 and 18 come into contact with the protrusions 6 and 8 and an excessive load is generated.

  In the above-described embodiment, the vertical play of the locking holes 16 to 18 with respect to the protrusions 6 to 8 is illustrated to be large for the sake of explanation, but it is actually a slight amount. In the above-described embodiment, the center projection 7 and the locking hole 17 are used as a reference. However, the left and right projections 6 and 8 and the locking holes 16 and 18 can be used as a reference. Further, in the above-described embodiment, the locking holes are enlarged with reference to the protrusions having the same dimensions as each other. However, since the relationship between the protrusions and the locking holes is relative, the locking holes are made to have the same dimensions. The width of the protrusion may be changed.

  Moreover, in the above-described embodiment, the case where there are three protrusions and three locking holes has been described, but the case where there are two or four or more two-dimensional planes can be similarly applied. One projection and the locking hole are used as a reference, and another projection and the locking hole are provided with a margin. Moreover, in the above-mentioned embodiment, although each shape of the protrusion and the locking hole is a rectangle, it can be similarly applied to a case of a circle or a square.

  The present invention can be used for other optical devices and apparatuses having a structure for supporting a plate-like component such as a diffusion plate in an atmosphere where the temperature varies, in addition to the backlight device.

It is the vertical side view and front view which show embodiment of the backlight apparatus which concerns on this invention. It is a disassembled perspective view which shows engagement of the diffusion plate in the backlight apparatus of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Housing | casing 2 Reflecting plate 3 Fluorescent tube 4 Diffusion plate 5 Contact recessed part 6-8 Protrusion 9 Optical sheet 16-18 Locking hole

Claims (3)

A backlight in which a light source is arranged inside a shallow box-shaped housing supported in a vertical direction, and two or more protrusions are provided on the front upper portion of the casing, and a diffusion plate is locked to the protrusions. In the device
The lateral width of one of the two or more locking holes formed in the diffusion plate is made substantially the same as the lateral width of the projection, and the lateral width of the other locking holes is made larger than the lateral width of the projection. Backlight device characterized. A light source is arranged inside a shallow box-shaped housing supported in the vertical direction, and two or more protrusions are provided on the front surface of the housing on the same straight line in the horizontal direction, and a diffusion plate is provided on the protrusion. In the backlight device that locked
The lateral width of one of the two or more locking holes formed in the diffusion plate is made substantially the same as the lateral width of the protrusion inserted into the locking hole, and the lateral width of the other locking holes is A backlight device characterized in that it is larger than the lateral width of the protrusion inserted into the hole. The backlight device according to claim 1 or 2,
The backlight device characterized in that the height of each of the locking holes is substantially the same as the height of each of the projections inserted into the locking holes.

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