초록 ▼

In a surface light source device of side light type applied to a liquid crystal display device, etc., more specifically a surface light source device of side light type having a directivity emitting characteristic, a bright-and-dark-band contrast which is generated in a vicinity of an incidence surf

In a surface light source device of side light type applied to a liquid crystal display device, etc., more specifically a surface light source device of side light type having a directivity emitting characteristic, a bright-and-dark-band contrast which is generated in a vicinity of an incidence surface is prevented. In a surface light source device of side light type, light diffusible areas composed on main-and-supplementary diffusible areas are formed on a slanted surface and an emitting surface of a light guide plate having a directivity emitting characteristic. A silver sheet is fixed to a projected portion of a prism sheet along an upper edge, and an illumination light which arrives at the upper edge from a fluorescent lamp is blocked so that the strong brightening of the upper edge is prevented. An illumination light form a lower edge is blocked by a reflector or a frame and reflected diffusively. The light diffusible area may be formed on one of the slanted surface and the emitting surface. Moreover, the light diffusible area may be formed on an additional element such as a reflection sheet.

대표청구항 ▼

[ What is claimed is:] [1.] A surface light source device of side light type comprising:a light guide plate having an incidence surface and major surfaces including an emitting surface and a surface opposite to the emitting surface, the incidence surface running along the major surfaces in an incide

[ What is claimed is:] [1.] A surface light source device of side light type comprising:a light guide plate having an incidence surface and major surfaces including an emitting surface and a surface opposite to the emitting surface, the incidence surface running along the major surfaces in an incidence direction; anda rod-type light source arranged along the incidence surface supplying light through the incidence surface, wherein a belt-like light diffusible area preventing a bright-and-dark-band contrast from appearing, is arranged in direct contact with at least one of the major surfaces so as to be parallel to the incidence direction.