JP3068705U - Surface light source plate for liquid crystal display - Google Patents

Abstract

(57) [Problem] To provide a surface light source plate for a liquid crystal display device which is excellent in light reflectivity and excellent in workability and productivity. SOLUTION: A light-reflective coating layer is provided on an end face other than a light incident portion without polishing the end face.

Description

[Detailed description of the invention]

[0001]

[Technical field to which the invention belongs]

 The present invention relates to a surface light source plate for a liquid crystal display device, and more particularly to a surface light source plate made of a plastic light guide plate of an edge light type used for a backlight of the liquid crystal display device.

[0002]

[Prior art]

 Conventionally, such a surface light source plate for a liquid crystal display device generally stores light incident from a light-emitting lamp in the surface light source plate, and improves the brightness of the surface (light surface) of the surface light source plate by improving the brightness of the surface (light surface). The light reflecting tape was stuck on the end face, and was constituted.

[0003] However, in the case of using such a light-reflective tape sticking method, the reflection is hindered by the presence of the adhesive used for the sticking, so that the light is efficiently reflected. As a result, there was naturally a limit on the surface (light surface) luminance improvement.

In addition, the plastic light guide plate for the surface light source plate is appropriately cut or molded according to the size and shape of the target liquid crystal display unit. Since the end surface is roughened and peeling easily occurs as it is, when applying the light reflective tape, the end surface to be applied must be polished beforehand, which is overlooked in terms of production efficiency and cost. In fact, it was an impossible problem. In the case of the latter molding, although the surface is not as rough as the difference, in the case of a light guide plate having a notch or a protrusion on the outer peripheral end surface, a light reflective tape should be adhered to the uneven end surface. Was extremely difficult and became a major problem in terms of work efficiency.

[0005]

[Problems to be solved by the invention]

 The present invention has been made in view of the above-mentioned conventional problems and actual situations, and has as its object to provide a surface light source plate for a liquid crystal display device which is excellent in light reflectivity and excellent in workability and productivity. .

[0006]

[Means for Solving the Problems]

 The present invention has achieved the above object by a surface light source plate for a liquid crystal display device having a light-reflective coating layer formed on an end face other than the light incident portion without polishing the end face.

[0007]

[Embodiment of the invention]

 Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIGS. 1 and 2 show a first embodiment. Referring to FIGS. 1 and 2, reference numeral 10 denotes a surface light source plate, which is an edge-light type plastic light guide plate cut into a rectangular shape. , Except for the light-incident end face 11, except for polishing the end faces 12, 13, and 14 on the other three non-light-incident end faces 12, 13, and 14 without directly polishing the end faces 12, 13, and 14. Are formed. The specific method of forming the light-reflective coating layer 20 is not limited to a coating method, a spray method, a printing method, or the like. Further, the paint forming the light-reflective coating layer 20 is not particularly limited as long as it can reflect light, but it is particularly preferable to use an aluminum powder-containing paint. Reference numeral 15 denotes a front surface (light surface) of the surface light source plate 10, and 16 denotes a back surface thereof, and a light reflective sheet 30 is adhered to an outer surface thereof. Reference numeral 40 denotes a light-emitting lamp, which is installed facing the light-entering portion end face 11 of the surface light source plate 10.

FIG. 3 shows a second embodiment, in which two light-entering end faces 11 a and 11 b are provided on a surface light source plate 10, and a light-emitting lamp 40 is installed on each of the two light-entering lamps. The light-reflective coating layer 20 is formed directly on the non-light-entering end surfaces 12a and 12b of the above without polishing.

[0010]

[Effect of the invention]

 Since the surface light source plate for the liquid crystal display device of the present invention has a light-reflective coating layer formed directly on the end face other than the light-entering portion, there is no light reflection hindrance due to the presence of the adhesive layer. Light that has entered through the end surface of the light incident portion is efficiently reflected by the light-reflective coating layer on the end surface of the non-light incident portion, returns to the surface light source plate, and is emitted from the surface (light surface) of the surface light source plate. As a result, the surface (light surface) of the surface light source plate shines efficiently. In particular, when the light guide plate is cut and formed, the coating layer is formed directly on the unpolished rough end face to enhance its binding force. Since there is no possibility of peeling as described above, the luminance of the surface (light surface) is stably maintained for a long time without decreasing.

Moreover, since the light-reflective coating layer of the surface light source plate for the liquid crystal display device of the present invention is formed without polishing on the end face other than the light-entering portion, a polishing step is required. Compared with the conventional surface light source plate, it is extremely excellent in productivity, and because of the coating layer, even a light guide plate having notches or protrusions on the outer peripheral end surface can be formed very easily. It has excellent workability compared to the conventional tape sticking method.

[Brief description of the drawings]

FIG. 1 is a schematic plan view showing a first embodiment of a surface light source plate of the present invention.

FIG. 2 is a schematic cross-sectional explanatory view taken along a line II in FIG. 1;

FIG. 3 is a schematic plan view showing a second embodiment of the surface light source plate of the present invention.

[Explanation of symbols]

 10: Surface light source plate 11: Light incident part end face 11a, 11b: Light incident part end face 12, 13, 14: Non light incident part end face 12a, 12b: Non light incident part end face 15: Front surface (light surface) 16: Back surface 20 : Light-reflective coating layer 30: light-reflective sheet 40: light-emitting lamp

Claims (4)

[Utility model registration claims] 1. A surface light source plate for a liquid crystal display device, comprising a light-reflective coating layer formed on an end face other than the light incident portion without polishing the end face. 2. The surface light source plate for a liquid crystal display device according to claim 1, wherein the light-reflective coating layer is made of a paint containing aluminum powder. 3. The surface light source plate for a liquid crystal display device according to claim 1, wherein a light reflective sheet layer is formed on a back surface of the surface light source plate. 4. The liquid crystal according to claim 1, wherein the surface light source plate is an edge light type plastic light guide plate surface light source plate used for a backlight of a liquid crystal display device. Surface light source plate for display device.