JPH1138412A - Light scattering resin panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a back surface light emission plate having high brightness and a uniform light emission characteristic by dispersing transparent single particulates having a refractive index different from the refractive index of a transparent resin into the transparent resin, thereby constituting a panel body. SOLUTION: The light scattering resin panel 1 comprises the panel body 2 and a reflection layer 3 disposed in the back part of the panel body 2. The panel body 2 consists of the transparent resin 2a and the transparent single particulates 2b dispersed in the transparent resin 2a. The transparent single particulate 2b are required to have the refractive index different from the refractive index of the transparent resin 2a, by which the good light scatterability is exhibited. The compounding ratio of the transparent single particulates 2b is 0.01 to 0.8 pt.wt. per 100 pts.wt. transparent resin 2a in the panel. The good light scattering effect is not obtainable if the ratio is smaller than 0.01 pt.wt. The light guide performance is lost and the uniform emission is not obtainable if the ratio is larger than 0.8 pt.wt.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light-scattering resin panel suitably used as a back light for word processors, personal computers, televisions, liquid crystal displays and the like.

[0002]

2. Description of the Related Art
As a means for back lighting of a word processor, a personal computer, a television, a liquid crystal display device, etc., a back light emitting plate which emits light uniformly is used. In this case, a direct type in which the light source is disposed behind the rear light emitting plate and an edge light type in which the light source is disposed on the side (side end face) of the rear light emitting plate are known.

[0003] As a direct-type rear light emitting plate, a light diffusing plate in which fine particles for light scattering are mixed with a transparent resin base material in order to uniformly diffuse light from a light source is used. Usually, 1 to 20% of light scattering fine particles are blended, and when the blending amount is small, there is a problem that the outline of the light source behind can be seen through.

On the other hand, a transparent light guide plate is used as an edge light type rear light emitting plate, and a reflective layer printed with a mesh is disposed on the back surface of the light guide plate in order to scatter light.
Further, a uniform surface light source is obtained by laminating a diffusion sheet on the upper surface of the light guide plate.

In recent years, the edge light type has been widely used in response to needs for thinness and energy saving. However, since it is difficult to obtain uniform light emission characteristics, the special reflection layer on the back surface of the light guide plate is mechanically processed. At present, such measures are taken by taking additional measures such as attaching a diffusion sheet called a prism sheet to the upper surface of the light guide plate, and a simple, high-brightness, uniform back light-emitting plate has not been obtained.

[0006] Further, as the colorization of the liquid crystal display device is progressing, it is desired that the rear light emitting plate has higher luminance.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an edge-light type rear light-emitting plate (light-scattering resin panel for rear illumination) having high luminance and uniform light-emitting characteristics.

[0008]

Means for Solving the Problems and Embodiments of the Invention The present inventor has conducted intensive studies in order to achieve the above object, and as a result, has developed a light source for backlighting which emits light from a light source arranged on the side or inside. In the light diffusion panel, this panel body is
In the transparent resin, the transparent single fine particles having a refractive index different from that of the transparent resin are used in an amount of 0.01 to 100 parts by weight of the transparent resin.
The brightness is very high by constituting the panel body dispersed by 0.8 parts by weight, and in this case, in particular, by forming the panel body so as to become gradually thinner as it goes away from the light source, further higher brightness and uniformity The present inventors have found that a light-scattering resin panel for back lighting capable of emitting light can be obtained, and have accomplished the present invention.

Hereinafter, the present invention will be described in more detail. A light-scattering resin panel of the present invention is a light-scattering resin panel for back lighting which emits light from a light source disposed on a side or an inner side thereof. Is composed of a panel body in which transparent single fine particles having a refractive index different from that of the transparent resin are dispersed in a transparent resin at a ratio of 0.01 to 0.8 parts by weight based on 100 parts by weight of the transparent resin. It is.

FIGS. 1 to 4 show an example of the light scattering resin panel 1, which is composed of a panel main body 2 and a reflection layer 3 provided at the back of the panel main body 2. The main body 2 includes a transparent resin 2a and the transparent resin 2a.
And transparent single fine particles 2b dispersed therein.

Here, as the transparent resin 2a, acrylic resin (PMMA), polycarbonate, polystyrene,
Polynorbornene, 4-methylpentene-1 resin, acrylonitrile styrene resin, cyclic polyolefin and the like are used.

On the other hand, the transparent single fine particles 2b need to have a refractive index different from that of the transparent resin 2a, thereby exhibiting a good light scattering property. in this case,
The refractive index of the transparent single fine particles 2b is 0.01 to 0.5, more preferably 0.1 to 0.5, with the refractive index of the transparent resin 2a used.
It is preferable that the difference is about 02 to 0.2 (the refractive index is large or small). Examples of the fine particles include inorganic fine particles such as glass fiber, glass beads, talc, silica, alumina, magnesia, zinc white, calcium carbonate, barium sulfate, titanium white, aluminum hydroxide, mica, feldspar powder, quartz powder, and silicone resin. , Fluororesin, epoxy resin, organic fine particles such as styrene-based crosslinked resin can be used, and one of these can be used alone or in combination of two or more. Among these, from the viewpoint of transparency, Silicone resins are preferred. The average particle diameter of the fine particles is preferably from 0.2 to 10 μm, particularly preferably from 0.2 to 5 μm.

The amount of the fine particles is 0.01 to 0.8 parts by weight, preferably 0.0 to 0.8 parts by weight, per 100 parts by weight of the transparent resin.
2 to 0.4 parts by weight. When the amount is less than 0.01 part by weight, a good light scattering effect cannot be obtained, and when the amount is more than 0.8 part by weight, light guide performance is lost, and uniform light emission cannot be obtained.

The panel body 2 can be formed in a plate having a uniform thickness as shown in FIG.
In order to obtain more uniform light emission, it is preferable to form the thinner as the distance from the light source 4 increases as shown in FIGS. In this case, the light sources 4 can be arranged on one side of the panel main body 2 (FIG. 2), or can be arranged on both sides of the panel main body 2 (FIG. 1).
3 and 4), when the light source 4 is arranged on one side of the panel main body 2, as shown in FIG. 2, the light source 4 is arranged from one end of the panel main body 2 to the other end. It is preferable to form the panel main body 2 so as to be gradually thinner. When the light sources 4 are arranged on both sides of the panel main body 2, respectively, as shown in FIGS. It gradually becomes thinner toward the center,
Although it is preferable to form the panel main body 2 so that the center portion is the thinnest, as shown in FIGS. 2 to 4, in any case, no inclined surface or concave surface is formed on the front surface, It is preferable that the rear surface is formed to be inclined or concave so as to be thin.

In FIGS. 1 to 4, the light source 4 is disposed on the side of the panel main body 2. However, if necessary, the light source is disposed in the panel main body 2 and disposed near one end or both ends thereof. can do.

The reflective layer 3 preferably has a reflectivity of 90% or more, for example, a white plastic film,
The reflection layer 3 can be formed smoothly, for example, by paper.

In the light scattering resin panel of the present invention, light from the light source 4 is incident on the transparent resin 2a, and the incident light is scattered by the single transparent fine particles 2b dispersed in the transparent resin 2a. Light is emitted from the front surface of the panel main body 2 and illuminates a word processor, a personal computer, a television, a liquid crystal display device, and the like disposed in front of the panel main body 2, and is thus scattered by the single transparent fine particles 2b. Since light is emitted from the front surface of the panel main body 2, the brightness is high. In this case, the panel main body 2 does not necessarily need a reflective layer. However, when the reflective layer is provided, light that is scattered by the single transparent fine particles 2b and does not travel to the panel main body 2 but also travels to the reflective layer 3 is also reflected. Since most of the light reflected by the layer 3 and incident on the panel main body 2 exits from the front surface of the panel main body 2, the brightness is high. Further, by forming the panel main body 2 so as to become thinner as the distance from the light source 4 increases, the amount of light scattered by the single transparent fine particles 2b and directed toward the front surface of the panel main body 2 is made as uniform as possible. Is more assured.

Therefore, the light-scattering resin panel of the present invention is suitably used for back lighting of word processors, personal computers, televisions, liquid crystal display devices and the like.

[0019]

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to the following examples.

[Example] Acrylic resin (refractive index: 1.4)
0.3 parts by weight of silicone resin fine particles (refractive index: 1.43, average particle diameter: 2 μm) were added to 9), and light-scattering resin panels shown in FIGS. 1 to 4 were produced by injection molding. 1.75 W cold cathode tubes were set on each of the light scattering resin panels as shown in FIGS. When a reflective sheet made of a white plastic film was adhered to the back surface of the light-scattering resin panel and the prism sheet was used on the upper surface, uniform light emission was obtained.

[0021]

The light scattering resin panel of the present invention has a high luminance and can emit light relatively uniformly.

[Brief description of the drawings]

FIG. 1 is a sectional view of a light-scattering resin panel according to one embodiment of the present invention.

FIG. 2 is a cross-sectional view of a light-scattering resin panel according to another embodiment of the present invention.

FIG. 3 is a sectional view of a light-scattering resin panel according to another embodiment of the present invention.

FIG. 4 is a sectional view of a light-scattering resin panel according to still another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Light-scattering resin panel 2 Panel main body 2a Transparent resin 2b Transparent single fine particle 3 Reflective layer 4 Light source

Claims (4)

[Claims] 1. A light-scattering resin panel for back lighting which emits light from a light source disposed on a side or an inner side, wherein the panel main body has a transparent resin having a refractive index different from that of the transparent resin. A light-scattering resin panel comprising a panel body in which fine particles are dispersed at a ratio of 0.01 to 0.8 parts by weight with respect to 100 parts by weight of the transparent resin. 2. The light-scattering resin panel according to claim 1, wherein a reflective layer having a reflectivity of 90% or more is provided on the back. 3. The light-scattering resin panel according to claim 1, wherein the panel main body is formed so as to become gradually thinner as the distance from the light source increases. 4. The transparent single fine particles have an average particle size of 0.2 to 1
4. The light-scattering resin panel according to claim 1, wherein the light-scattering resin panel is a silicone resin fine particle of 0 μm.