JPH0573630U - Rear illuminator - Google Patents

Abstract

(57) [Abstract] [Purpose] Claims for a back lighting device, characterized in that a lamp holder for housing a cylindrical light source is built in and integrated with one end or both ends of the light guide layer. . [Structure] The means adopted by the present invention is shown in FIGS.
The light guide layer 4 as shown in FIGS. 2 and 3 is integrally formed between the conventional light reflector 6 shown in FIG. As shown in FIGS. 4 and 5, the inner wall surface of the rear portion of the lamp holder 1 or
The problem is solved by making the outer end of the lamp holder 1 into a saw-tooth upper protrusion. That is, the cylindrical light source 2
Light rays emitted from the rear part are refracted and irregularly reflected by the saw-toothed projections to efficiently irradiate the entire surface and improve the brightness. By integrally molding the lamp holder and the light guide layer, the impact resistance can be improved and the cost effect can be sufficiently enhanced.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to various display devices, in particular, back illuminators for liquid crystal display panels such as word processors, personal computers and televisions, and back illuminators for inspection such as liquid crystal display panels.

[0002]

[Prior Art]

 Heretofore, there has been a method of rear illumination using a cylindrical light source such as a fluorescent tube as shown in a perspective view or a sectional view in FIGS. That is, in FIG. 1 (A) and (B), the structure is such that the light beam emitted from the outer half of the cylindrical light source 2 is efficiently guided to the center side of the light guide layer 4 by the light reflector 6. There is.

However, in this back lighting device, since the cylindrical light source 2 and the light guide layer are not integrated, impact resistance is weak and cost is high.

Further, there is also a drawback that the utilization efficiency of the light rays emitted from the outside of the cylindrical light source 2 is poor.

[0005]

[Problems to be solved by the device]

 The present invention belongs to an indirect illumination type back lighting device having a light reflector 6 and a light guide layer 4 as shown in FIG. Generally, the conventional back illuminator has a drawback that the light emitted from the rear portion of the cylindrical light source 2 cannot be effectively used.

Further, since it is necessary to prepare the light reflector 6 separately from the light guide layer, there are problems in impact resistance and cost.

[0007]

[Means for Solving the Problems]

 In order to effectively solve the above problems, the present invention is provided between the conventional light reflector 6 shown in FIGS. 1 (A) and 1 (B) and the cylindrical light source 2 as shown in FIGS. The light guide layer 4 is integrally molded.

In addition, as shown in FIGS. 4 and 5, the inner wall surface of the rear portion of the lamp holder 1 or the outer end portion of the lamp holder 1 is formed into a saw-toothed projection. That is, the light rays emitted from the rear part of the cylindrical light source 2 are refracted and irregularly reflected by the saw-toothed projections to efficiently irradiate the front surface and improve the brightness, and the lamp holder and the light guide layer are integrally formed. Thus, the impact resistance can be improved and the cost effect can be sufficiently enhanced.

[0009]

Embodiment 1 A sectional view and a perspective view of an embodiment of the present invention are shown in FIGS. Reference numeral 4 in the drawing is a light guide layer, and in this case, transparent acrylic is molded by an injection molding method. 2 is a cylindrical light source, for example, a cold cathode tube. The cylindrical light source 2 is housed in the lamp holder 1.

In this embodiment, a light guide layer 4 is arranged between a light reflector 6 of a conventional example and a cylindrical light source 2, and a light beam at the rear of the cylindrical light source 2 is efficiently guided by the light reflector 6. By guiding the light to the center of the light layer and integrating the lamp holder with the light guide layer, the mechanical strength is increased.

Second Embodiment FIG. 4 shows this embodiment. 3 is a display front display panel. Reference numeral 4 is a light guide layer, and an aluminum vapor deposition film is deposited as a light reflector 6 by a vacuum vapor deposition method.

In this embodiment, saw-toothed protrusions are provided on the inner wall surface of the rear portion of the lamp holder 1. Light rays emitted from the rear half of the cylindrical light source 2 are efficiently guided to the center side of the light guide layer 4 by the saw-toothed projections and strongly illuminate the front display panel 3, so that a high-brightness rear illumination device can be obtained. it can.

In the present embodiment, when each cold cathode tube was turned on with an electric power of 3.2 watts, a brightness of 1430 cd / m ² was obtained.

On the other hand, when the brightness was measured under the same conditions for the conventional rear illumination device shown in FIGS. 1A and 1B, the measurement result was 1200 cd / m ² . Therefore, it can be said that this embodiment has higher brightness than the conventional back lighting device. In addition, each of the above-mentioned luminance distribution measurements was carried out by using Topcon Color Luminance Meter BM-7, and the same applies to the luminance measurements in each of the examples described below.

[Third Embodiment] In FIG. 5, the outer end of the lamp holder 1 is replaced by a serrated projection instead of the inner wall surface of the rear portion of the lamp holder 1 of the first embodiment.

A light diffusing layer 5 was added between the front display panel 3 and the light guide layer 4 so as to eliminate uneven brightness. The luminance of this example was measured under the same conditions as in Example 1, and as a result, a luminance of 1560 cd / m ² was obtained.

[Brief description of drawings]

FIG. 1A and FIG. 1B are perspective views or cross-sectional views of a conventional back lighting device, respectively.

FIG. 2 and FIG. 3 are perspective views or cross-sectional views of a rear illumination device in which a light guide layer 4 is arranged between a cylindrical light source 2 and a light reflector 6 of a conventional rear illumination device, respectively.

4 (A) and 5 (A) are front views showing various embodiments of the present invention, and FIG. 4 (B) and FIG.
(B) is a sectional view taken along line XX, and the details thereof are as described in the description of each embodiment. 1 to 5, the reference numerals in the drawings indicate the following, respectively.

[Explanation of symbols]

 1 Lamp Holder 2 Cylindrical Light Source 3 Front Display Panel 4 Light Guide Layer 5 Light Diffuser 6 Light Reflector

Claims (4)

[Scope of utility model registration request] 1. A rear illumination device, characterized in that a lamp holder for accommodating a cylindrical light source is built in and integrated with one end or both ends of the light guide layer. 2. The rear illumination device according to claim 1, wherein the inner wall surface of the rear portion of the lamp holder is serrated. 3. A rear illumination device according to claim 1, wherein the outer end portion of the lamp holder is serrated. 4. The light guide layer according to claim 1, wherein:
A back illuminating device characterized in that it is provided with serrated projections.