| 摘要 |
PROBLEM TO BE SOLVED: To set a light scattering part to an optional form such as polyhedral cone or roof form and to an arbitrary distribution in a planar state, and improve the luminance of a back light liquid crystal panel by forming a molding base die from a base die forged by a punch through electric casting, and injection molding a light guide plate from a light-transmitting resin material. SOLUTION: A work surface is forged by one punch or a plurality thereof so as to manufacture a base die having conical, polyhedral conical or roof- shaped recessed parts, so that the distribution is successively changed to have a density substantially proportional to the distance from a light source 4. The apex of the recessed part is set to a range of 80-130 deg.C, and the work surface is set to either gloss or rough surface. A molding metal die having protruding parts is manufactured by the transfer from the base die, by a transfer method including electric casting. A light-transmitting resin material is injection molded by the use of this molding die to manufacture a light guide plate 1, having a numerous number of recessed parts 6. The light which is incident from the light source 4 is reflected at the inclined surfaces of the recessed parts 6 and emitted to a light-emitting surface 1a for lighting a liquid crystal panel 15 via a diffusion plate 2. |
