| 摘要 |
PURPOSE: To suppress and remove stripe- or line-shaped bright and dark patterns appearing on the display surface of a liquid crystal display and to impart adequate spread to a visual field angel. CONSTITUTION: The light of a light source L advanced from a light incident surface 2 into a light scattering light transmission body 1 is subjected to one time or multiple scattering effects in the process that light propagate in the body. The corresponding part of the light arriving at both surfaces 5, 6 of the light scattering light transmission body 2 or the front surface of a reflector 3 is returned into the light scattering light transmission body 1. The light subjected to such effects in combination is emitted with directivity toward an arrow 5a from a light take-out surface 5 with a high efficiency and is made incident on a light exit direction correcting element 4'. The light incident surface of the light exit direction correcting element 4' is formed as prism array-like undulating surfaces 4a, 4b and the light exit surface 4e' is formed as an embossed surface. The propagation direction of the exit light from the light exit surface 4e' is spread while the directivity is made to remain. Consequently, the bright and dark patterns are hardly visible through the liquid crystal panel LCP and the visual field angle is expanded. These effects are intensified if scatterability is imparted to the inside of the light exit direction correcting element 4'. |
