| 摘要 |
<P>PROBLEM TO BE SOLVED: To achieve energy saving and high productivity through a high utilization factor of light, for a downright system plane light source element with high front luminance and enhanced luminance uniformity. <P>SOLUTION: The plane light source element substitutes a generally used particulate diffusing plate with a support substrate having rib-like convex parts on its irradiation face, and further, a light control sheet having rib-like convex parts on its irradiation face is used. The support substrate can avoid or greatly reduce use of particulates and light absorption by the particulates or light emission toward unnecessary directions is reduced, so that light utilization efficiency is enhanced and energy saving is realized. Further, the light control sheet efficiently deflect irradiation light from the support plate toward a front direction, so that high front luminance can be obtained, and that, the irradiation light from the light control sheet shows a smooth angle distribution of luminance with luminance monotonously lowering from a front direction toward a wide angle side, so that a high screen definition can be obtained, Moreover, the rib-like convex parts of the light control sheet have their tiptop parts in a curved surface, so that they hardly get hurt, hence, a high productivity. <P>COPYRIGHT: (C)2008,JPO&INPIT |
