Tosoh Corporation

Nippon Silica Glass Co., Ltd.

Osamu Shoji

Naoki Yoshida

Keiji Kashima

Takumi Fukunishi

Eiichi Yanagi

In a backlighting device for use with display panels that comprises a light conducting plate made of a light-transmissive material, one of the major faces of said light conducting plate being provided with a light diffusing capability and covered with a specular or light diffusing/reflecting plate, and a linear light source provided in proximity to the end portion of at least one side of said light conducting plate, the improvement wherein at least one sheet that is made of a light-transmissive material and that has a multiple of raised structures having straight ridgelines at minute intervals on the same side in such a manner that the ridgelines are substantially parallel to one another or at least one sheet that is made of a light-transmissive material and that has a multiple of pyramidal or conical projecting structures at minute intervals on the same side, said projecting structures having portions of such a shape that the vertical angles are substantially the same, is provided on the exit face of the light conducting plate in such a way that either type of structures face outward.

Backlighting device

A backlighting device for display panels operating on the edge lighting method that comprises a light conducting plate made of a light-transmissive material, a layer of light-diffusing material that partly covers one major surface of the light conducting plate, and a light diffusing/reflecting plate that covers the thus covered area of the light conducting plate. The light conducting plate is provided on its exit face with a film that is coarser grained on the exit face than on the entrance face (the side closer to the light conducting plate) and which, when provided on the exit face of the light conducting plate, will increase the luminance of light issuing from the exit face of the light conducting plate. This backlighting device produces satisfactory luminance and can be used as a high-performance model that achieves a high efficiency of power to luminance conversion at least in the direction of the line normal to the exit face.

A back lighting device which comprises a light conducting plate made of a light-transmissive material, a linear light source provided in proximity to the end portion of at least one side of the light conducting plate, a reflecting plate or film that covers the linear light source and which consists, in order from the light source side, of a specular reflecting plate or film, an air layer and a light diffusing/reflecting plate or film in superposition. One surface of the light conducting plate is provided with a light diffusing capability and covered with a specular or light diffusing/reflecting plate. Thereby, it is possible to provide a back lighting device that has a high efficiency of power to luminance conversion and which hence is capable of achieving high luminance.

Back lighting device

An improved backlighting device for liquid-crystal display panels comprising a linear light source the length of which is equal to or less than the length of an end portion of a light conducting plate at which light is admitted from the linear light source placed adjacent to it, the linear light source being enclosed with a light diffusing reflector that has a slit formed in the surface through which incident light is admitted into the light conducting plate and which is provided in such a way as to form a clearance from the surface of the linear light source, one major surface of the light conducting plate being partially covered with a light diffusing material under specified conditions that has a higher refractive index than the material of which the light conducting plate is made, the major surface being further covered with a specular or light diffusing/reflecting plate, with a plurality of light diffusing plates being provided on the other major (light emerging) surface of the light conducting plate.

Back lighting device for a panel

A back lighting device for a liquid crystal display has a light scattering coating in the form of dots covering the light emitting surface of a photo-conductive plate. The coating covers 3-50% of the surface nearest an end thereof adjacent a linear light source and covers 80-100% of the surface farthest from the light source. The variation of the coating rate across the surface produces uniform distribution of emitted light from the back lighting device.

Growing community of inventors

Tokyo, Japan

Osamu Shoji