JPH06109926A - Light transmission plate device - Google Patents

Abstract

PURPOSE:To improve the brightness of a light emitting surface and to eliminate dazzling by providing a diffusion plate on the light emitting surface side of a light transmission plate. CONSTITUTION:This light transmission plate device is provided with the light transmission plate 11 having the light emitting surface 12, and the light emitting surface 12 side is allowed to emit light by radiating the light made incident on the light transmission plate 11 from the light emitting surface 12. The diffusion plate 17 obtained by applying synthetic resin paint 20 containing many beads 19 to a transmissive film 18 is provided on the light emitting surface 12 side of the light transmission plate 11.

Description

Detailed Description of the Invention

[0001]

The present invention relates to a liquid crystal backlight,
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a backlight for advertising signs and a light guide plate device used for lighting equipment.

[0002]

2. Description of the Related Art FIG. 4 shows a conventional light guide plate device disclosed in, for example, Japanese Patent Laid-Open No. 3-264982, and 1 is a light guide plate which is made of acrylic resin. One surface of the light guide plate 1 is a light emitting surface 2, and the other surface is a reflecting surface 3. Light guide plate 1
A light-shielding member 4 for preventing light leakage is attached to the reflection surface 3 of the
The incident light is reflected by the reflecting surface 3 so that the light emitting surface 2 side emits light. Then, a milky white or embossed film 6 is attached on the light emitting surface 2 of the light guide plate 1, and the light emitted from the light emitting surface 2 is diffused by the film 6 so that the light emission is made uniform.

[0003]

However, since the light diffusion effect of the film 6 is large in the related art, the brightness of the light emitting surface 2 is decreased, and the transmittance is decreased due to milky white or embossing, and the surface of the film 6 is further decreased. There was a problem that the light emitting surface 2 was glaring due to the embossed shape of the. In view of the above problems, the present invention improves the brightness of the light emitting surface and eliminates glare.

[0004]

The technical means of the present invention for solving this technical problem comprises a light guide plate 11 having a light emitting surface 12, and the light incident on the light guide plate 11 is diffused from the light emitting surface 12. In the light guide plate device in which the light emitting surface 12 side is made to emit light, the light guide surface 11 side of the light guide plate 11 is provided with a diffusion plate 17 formed by applying a synthetic resin coating material 20 containing a large number of beads 19 to a transparent film 18. It is in the point provided.

[0005]

[Operation] Light incident on the light guide plate 11 is diffused from the light emitting surface 12. The light emitted from the light emitting surface 12 is emitted to the outside through the diffusion plate 17, and during this time, the light can be appropriately diffused by the beads 19, and the glaring of the light emitting surface 12 unlike the conventional case is eliminated.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the illustrated embodiments. In FIG. 1, 11 is a rectangular plate-shaped light guide plate made of acrylic resin, one surface of which is a light emitting surface 12 and the other surface is a reflecting surface 13. It is said that. 14 is a light source such as a lamp, and the light guide plate 11
The light from the light source 14 is arranged outside both end faces 15 of the light guide plate 11 and enters the light guide plate 11 from both end faces 15 of the light guide plate 11. Reference numeral 16 denotes a light-shielding cover, which covers the outer periphery of the light source 14 outside both end surfaces 15 of the light guide plate 11 so that the light of the light source 14 does not leak to the outside.

Reference numeral 16 denotes a reflecting member, which is formed by sticking a silver vapor deposition film on the inner surface of a polyethylene film, for example, and is stuck on the reflecting surface 13 of the light guide plate 11 so as to prevent light from leaking.
It is attached to both end surfaces of the light guide plate 11 on the side where the light source 14 is not provided. Reference numeral 17 denotes a diffusion plate provided on the light emitting surface 12 side of the light guide plate 11 and has a thickness of
To 50μm or more transmissive film (including a sheet) 18, formed by a synthetic resin coating 20 containing the beads 19 having a diameter of 5 [mu] m 30 .mu.m 50 to 90 ^{wt% 10g / m 2 ~40g / m} 2 coating. Transparent film 18
Is made of polyethylene terephthalate (PET), polycarbonate, acrylic or the like, and the beads 19 are made of acrylic or polyethylene.

The thickness of the transparent film 18 is set to 50 μm or more because it is not preferable if the thickness is less than 50 μm because handling, workability and coating performance are deteriorated. Further, the reason why the beads 19 have a diameter of 5 μm to 30 μm is that it is optimal for improving the arrangement of coating and condensing light on the front surface, and if it is too small, the light transmittance is lowered, which is not preferable. Also, the reason why the beads 19 are contained in the synthetic resin paint 20 in an amount of 50 to 90% by weight is that if the amount of the beads is less than 50% by weight, the coated surface tends to become uneven, and if it is more than 90% by weight, the beads 19 drop off. Is caused.

Next, the result of comparison between the embodiment of the present invention shown in FIG. 1 and the conventional example shown in FIG. 4 will be described. It should be noted that the light guide plate devices of the present invention and the conventional example are compared with each other in the same overall thickness, size, number of light sources 14, and light intensity. Figure 2
Indicates the brightness measured at 9 points on the effective light emitting surface of the light guide plate device in the embodiment of the present invention, and in this embodiment, the transmissive film 18 is made of acrylic beads having a diameter of 5 to 30 μm. A diffusion plate 17 coated with 20 g / m ² of a synthetic resin paint 20 containing 19 is used. Further, FIG. 3 shows the luminance measured at the same 9 points in the conventional example, and in this case, two films 6 made of polycarbonate with surface embossing are used in the conventional example. 2 and 3
As shown in, the embodiment of the present invention is
Has a higher brightness over the entire light-emitting surface, whereas in the present invention the average luminance is 1862cd / m ^2, when the average luminance of the prior art is 2236cd / m ^2, the present invention is conventional example The average brightness is improved by 20% compared to the one.

In the above embodiment, the present invention is applied to the edge type light guide plate device in which the light from the light source 14 is made to enter the light guide plate 11 from the end face of the light guide plate 11. Is not limited to this, and may be a direct type in which light is made to enter the light guide plate 11 from the surface facing the light emitting surface 12.

[0011]

According to the present invention, since the light guide plate 11 is provided on the light emitting surface 12 side with the diffusion plate 17 formed by applying the synthetic resin coating material 20 containing a large number of beads 19 to the transparent film 18, With improved transmittance, the light from the light emitting surface 12 can be appropriately diffused and can be diffused without waste, and therefore, the emission luminance on the light emitting surface 12 side can be significantly improved as compared with the conventional one. Glitter on the light emitting surface 12 can be effectively suppressed.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is a front view showing a measurement result of luminance of the light guide plate device of the present invention.

FIG. 3 is a front view showing a measurement result of luminance of a conventional device.

FIG. 4 is a cross-sectional view showing a conventional example.

[Explanation of symbols]

 11 Light guide plate 12 Light emitting surface 17 Diffuser 18 Transparent film 19 Beads 20 Synthetic resin paint

Claims (1)

[Claims] 1. A light guide plate (11) having a light emitting surface (12),
In a light guide plate device in which the light incident on the light guide plate (11) is diffused from the light emitting surface (12) and the light emitting surface (12) side is made to emit light, on the light emitting surface (12) side of the light guide plate (11), 1. A light guide plate device, comprising: a diffusion plate (17) formed by applying a synthetic resin coating material (20) containing a large number of beads (19) to a transparent film (18).