JPH0736034A - Fitting structure for light transmission plate - Google Patents

Abstract

PURPOSE:To obtain a fitting structure of a light transmission plate by which a wide range on the light transmission plate can be effectively used as a light emitting area by providing a small hole for positioning, engaging it with a boss projectingly provided on a fitting substrate side and executing potisioning. CONSTITUTION:The small hole 6 for positioning is provided near the light introducing edge 4 of the light transmission plate 5 and the edge 4 side is positioned by engaging the hole 6 with the boss 7 provided on the fitting substrate 2. Therefore, the light transmission plate 5 is held at a prescribed position by positioning the edge 4 side thereof by the boss 7 and positioning the corner parts thereof faced to the edge 4 by positioning ribs 8. The unevenness area of brightness formed at the back part of the boss 7 and the small hole 6 becomes small because the projecting area of the boss 7 viewed from a light source 3 can be comparatively made small and the unevenness area of the brightness is canceled by light advancing from oblique left and right directions with respect to the boss 7. Besides, the wide range of the light transmission plate 5 can be effectively used as the light emitting area 10.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mounting structure for a light guide plate used in a backlight such as a liquid crystal display.

[0002]

2. Description of the Related Art Generally, in a display device using a liquid crystal display, a backlight is used to enhance the contrast of the liquid crystal surface.

The backlight is constructed so that the light from a light source such as a lamp is guided to the back surface of the liquid crystal display through the light guide plate. In order to guide the light from the light source to the light guide plate efficiently, The light plate needs to be accurately held at the position where the light introducing edge is in contact with the light source.

A conventional example of such a light guide plate mounting structure is shown in FIG.
It shows in (a). In this conventional example, the light guide plate 5 has its corners positioned by the positioning ribs 8 that are L-shaped in plan view and are provided on the mounting base 2 so that the light-introducing edge 4 is brought into close contact with the light source 3 without stress. I am letting you.

[0005]

However, in the above-mentioned conventional example, the positioning rib 8 on the light source 3 side blocks the effective light emitting area of the light source 3 from the left and right, and the rear side of FIG.
As shown in (b), since the brightness unevenness 9 occurs, the light emitting area 10 cannot be used in the area, and as a result, the area that can be used as the light emitting area 10 becomes small. It was something that had.

The present invention has been made to solve the above-mentioned drawbacks, and provides a mounting structure of a light guide plate which can effectively use a wide area on the light guide plate as a light emitting area. To aim.

[0007]

According to the present invention, the above-mentioned object is, as shown in FIG. 1 corresponding to the embodiment, a mounting base 2 of a liquid crystal display 1, a light source 3, and a light abutting on the light source 3. A light guide plate 5 having an introduction edge 4 is provided, and a positioning small hole 6 is provided in the vicinity of the light introduction edge 4, and the positioning small hole 6 is provided on a boss 7 projecting on the mounting base 2 side. This is accomplished by providing a light guide plate mounting structure that fits and positions the light introducing edge 4 of the light guide plate 5.

[0008]

In the present invention, the positioning small hole 6 is provided in the vicinity of the light introducing edge 4 of the light guide plate 5, and the positioning small hole 6 is fitted to the boss 7 provided on the mounting base 2. The light introducing edge 4 side is positioned.

The area of uneven brightness 9 formed behind the boss 7 and the positioning small hole 6 allows the projection area of the boss 7 viewed from the light source 3 to be relatively small, and Since the uneven brightness 9 region is canceled by the light traveling obliquely from the left and right, the area becomes small, and the wide range of the light guide plate 5 can be effectively used as the light emitting area 10.

According to the second aspect of the present invention, the positioning small hole 6 is irradiated with an equal amount of light from the left and right oblique directions, and the brightness unevenness 9 region has a smaller area.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will now be described in detail with reference to the accompanying drawings. 1 to 3 show a display device to which the present invention is applied. The display device includes a mounting base 2 that supports the liquid crystal display 1, a reflector 11 arranged on the back surface of the liquid crystal display 1, a light guide plate 5, and a diffusion sheet 12 and a fluorescent lamp arranged beside the light guide plate 5. A rod-shaped light source 3 and a liquid crystal display 1
And the like, and an upper cover 13 for sandwiching them in cooperation with the mounting base 2, and is configured to guide the light from the light source 3 from the light introducing edge 4 to the light guide plate 5 and illuminate the back surface of the liquid crystal display 1.

The reflector 11 is guided to the light guide plate 5,
The diffusing sheet 12 is provided to reflect the light traveling to the mounting substrate 2 side to the liquid crystal display 1 side, and the diffusion sheet 12 diffuses the light emission at the light emitting point described later to diffuse the light.
It is provided to evenly illuminate the entire surface of.

The light guide plate 5 is made of a material having a good light transmission property such as acrylic resin, and dots 14 printed in white on the back surface are arranged in a matrix in substantially the entire area thereof to form a light emitting area. 10 is formed.

Further, the light introducing edge 4 of the light guide plate 5 is connected to the light source 3
In order to guide the light from the light source 3 to the light guide plate 5 efficiently, the light guide plate 5 is provided with positioning small holes 6. The positioning small hole 6 is provided in a region between the light introducing edge 4 and the light emitting area 10.

The distance between the positioning small hole 6 and the light emitting area 10 is such that the unevenness of brightness 9 is formed behind the positioning small hole 6 by blocking the light by the positioning small hole 6 and a boss 7 described later. Is set so as not to enter the light emitting area 10.

On the other hand, in the state where the positioning small hole 6 of the light guide plate 5 is fitted to the base body, the light introducing edge 4 of the light guide plate 5 is fitted.
And a boss 7 for positioning the light guide plate 5 so that the light source 3 closely contacts the light source 3, and an L-shaped front view for positioning a corner of a side edge of the light guide plate 5 facing the light introduction edge 4 at that position. A positioning rib 8 is provided so as to project.

Therefore, in this embodiment, the light guide plate 5
Is held at a predetermined position by positioning the light introducing edge 4 side by the boss 7 and the corner portion on the opposite side by the positioning rib 8.

In this state, the areas of uneven brightness 9 formed behind the boss 7 and the positioning small hole 6 are canceled and reduced by the light traveling obliquely to the positioning small hole 6 from the left and right directions. .

As described above, the length of the reduced brightness unevenness 9 region in the light emitting area 10 direction is the distance D between the positioning small hole 6 and the edge of the light emitting area 10, that is, as the light emitting area 10. Since the usable area is determined, it is necessary to reduce the radial dimension of the boss 7 and the positioning small hole 6, specifically, the projection area from the light source 3 to expand the light emitting area 10. Is very effective for.

When the positioning small holes 6 are arranged on the vertical bisector of the light guide edge, the positioning small holes 6 are formed.
Since the uneven brightness 9 region formed by is canceled out by the equal amount of light from the left and right as shown by the arrow in FIG.
This is more effective for expanding the light emitting area 10.

[0021]

As is clear from the above description, according to the present invention, the positioning small hole 6 is provided in the vicinity of the light introducing edge 4 of the light guide plate 5 so as to be in contact with the light introducing edge 4, and the mounting base is provided. Two
By fitting with the boss 7, the uneven brightness 9 region can be reduced, and an effective light emitting area 10 can be formed in a wide range of the light guide plate 5.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a main part of FIG.

FIG. 3 is a plan view showing a positioning state of a light guide plate.

4A and 4B are views showing a conventional example, in which FIG. 4A is a plan view and FIG. 4B is an enlarged view of a main part of FIG.

[Explanation of symbols]

 1 Liquid Crystal Display 2 Mounting Base 3 Light Source 4 Light Introducing Edge 5 Light Guide Plate 6 Small Hole for Positioning 7 Boss

Claims (2)

[Claims] 1. A liquid crystal display (1) mounting base (2), a light source (3), and a light guide plate (5) having a light introducing edge (4) abutting the light source (3), A positioning small hole (6) is provided in the vicinity of the light introducing edge (4), and the positioning small hole (6) is fitted to a boss (7) projecting on the mounting base (2) side. The light guide plate mounting structure for positioning the light introducing edge (4) of the light guide plate (5). 2. The mounting structure for a light guide plate according to claim 1, wherein the positioning small hole (6) is provided on a vertical bisector of the light introducing edge (4).