JPH01167883A - Light emitting device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a light-emitting device using a non-planar light-emitting body such as a spherical or tubular light-emitting body as a light-emitting source.

C. Prior Art] Conventional light-emitting devices install a tubular tungsten filament or fluorescent tube as a light-emitting body on a light-emitting surface, such as the back of a liquid crystal display that displays information, and directly emit light from the light-emitting body. After being reflected by a light scattering reflector or by a light scattering reflector, the light is irradiated onto the illumination surface through the light scatterer. When the light emitting body is spherical or tubular, it is difficult to uniformly irradiate the light emitted from it onto a flat illumination surface.
No. 3478 and Japanese Utility Model Application No. 59-22493, a light scattering body or a reflecting surface was provided between the light emitting body and the illumination surface of the display body to make the irradiated light uniform.

[Problem that the invention seeks to solve]

However, in the prior art, for example, the above-mentioned Japanese Unexamined Patent Publication No. 57-13478 discloses a milky white light scattering body between the light source and the liquid crystal panel, and the above-mentioned Utility Model Application No. 59-22493 discloses a light unevenness removing member formed with a light reflecting surface. Since the LCD panel is provided between the light source and the illumination surface, the brightness of the liquid crystal panel or the illumination surface is insufficient, making it difficult to read the displayed contents.

Furthermore, the presence of these members not only complicates the assembly process and increases manufacturing costs due to an increase in the number of parts, but also has the drawback that the overall thickness of the display panel incorporating the light source cannot be reduced.

An object of the present invention is to provide a light emitting device that eliminates the various drawbacks of the prior art described above.

[Means for solving problems]

The present invention is a light-emitting device comprising a light-emitting surface, a light-emitting body, and a reflecting plate, in which the light-emitting body is provided with means for blocking part of the light directed from the light-emitting body toward the light-emitting surface. .

〔Example〕

FIG. 1(a) shows an example in which the light emitting device of the present invention is incorporated into a liquid crystal display device. 1 is a polarizing plate, 2 is a liquid crystal display cell, 3 is a diffusion plate, 4 is a fluorescent tube as a light source, 5 is a reflection plate,
6 is direct light from the light source, 7 is reflected light from the light source, and 8 is a light shielding portion. 1 and 2 constitute a liquid crystal display device. The diffuser plate 3 diffuses the direct light 6 and reflected light 7 from the light source 4, and supplies more uniform light to the liquid crystal display device. 1(b), (c), and (d) are a plan view, a front view, and a side view of the fluorescent tube 4, respectively. Apply 10 to 20 g of black epoxy ink by tacho printing or screen printing.
It is coated to a thickness of μm, and the width a is 1ffI11
, the pitch b is 211Iffl, and the fluorescent tube 4 (diameter 6.
1/4 to 1/ of the surface area of 5mm to 8.0m+n)
Good results were obtained when the coating was applied at a ratio of 3:3.

The light-shielding part may be a mesh-like part as shown in FIG. 2(a), which can be printed continuously on the top of the fluorescent tube 4. Good results are obtained when the size of the mesh is 0.5 mm square. However, when the angle exceeds 1.0ffi, the light shielding effect becomes poor.

The mesh-like light-shielding portion may be printed in such a way that it is dark in the center of the fluorescent tube and gradually becomes thinner as it goes farther from the center, as shown in FIG. 2(b). Furthermore, as shown in FIG. 2(c), the area of the light-shielding portion may be gradually changed from the center of the fluorescent tube and printed, and the shape of the light-shielding portion in this case may not only be rectangular but also circular or triangular. .

FIG. 3(b) shows a cylindrical member 9 on which a light shielding portion 8 is printed in advance, and is an example in which this is placed over the outer periphery of the fluorescent tube 4 shown in FIG. 3(a).

The cylindrical member 9 receives heat from the fluorescent tube 4 (150" 0 position)
We use heat-resistant materials such as transparent polyimide film, polyether sulfone, and polyarylate that can withstand
The printing method is similar to the embodiment shown in FIGS. 1 and 2. FIG. 4 shows an example in which, instead of the cylindrical member 9, a transparent member 1O on which a light shielding portion 8 is printed in advance is adhered to the upper part of the fluorescent tube 4 using an epoxy adhesive or the like.

FIG. 5 shows an example in which a spherical light emitter 11 is provided with an annular light shielding portion 8. As shown in FIG. This figure is a diagram of the light emitting body seen from the illumination surface, but the light shielding part 8 also includes a dot-shaped part centered on the center part.
A radial band may be printed from the center toward the periphery. In each of the above embodiments, the light emitting device of the present invention is incorporated into a liquid crystal display device, but the light emitting device of the present invention can also be used in other display boards such as illuminated signboards, electric bulletin boards, or tracing using transparent light. It can be widely used as a light-emitting device for devices such as a light-transmitting table for observing a film or a Scherkersten for interpreting an X-ray film with a built-in fluorescent tube.

Further, in the case of the above-mentioned illuminated signboards, transparent stands, etc., manufacturing becomes easier if a light-transmitting member such as ground glass or an acrylic plate on which letters are formed is arranged as the illumination surface of the light-emitting device of the present invention. Although the diffusion plate 3 is disposed in this embodiment in order to obtain more uniform display characteristics (uniform and uniform brightness over the entire display surface) of the liquid crystal display device, it is not essential to the light emitting device of the present invention.

〔effect〕

Since the present invention has the above-mentioned configuration, all of the direct light from the light source does not irradiate the display body that displays information, and the light does not become intense in a localized area.

The present invention eliminates the drawbacks of the prior art described above, makes it possible to brighten the entire surface of the illumination surface to make it easier to read the display contents, and to provide a thin display device.

[Brief explanation of the drawing]

, FIGS. 1 to 5 show embodiments of the present invention. 1-・--・--polarizing plate, 2--・--1 liquid crystal display cell, 3--・--diffusing plate, 4---・・--
・−・Fluorescent tube, 5・−・−・・Reflector, 6−・
−・−・−Direct light, 7−−−−−−・Reflected light,
8--・---- light shielding part, 9--- cylindrical member,
1o--Transparent member, 11--...Spherical luminous body

Claims (1)

[Claims] 1. A light-emitting device comprising a light-emitting surface, a light-emitting body, and a reflecting plate, wherein the light-emitting body is provided with means for shielding a part of the light from the light-emitting surface from the light-emitting body.