| 摘要 |
PURPOSE:To obtain high illuminance by forming a reflection layer on light diffusion patterns, disposing a long-sized light source at the end face of a light transmission plate and emitting light from the other main surface side of this light transmission plate. CONSTITUTION:The one main surface of the light transmission plate 10 is provided with many grooves and the light diffusion patterns 11 having a light diffusion function are formed by these grooves. The other main surface is provided with a light diffusion plate 12 made of a PET or polycarbonate (PC) and a long-sized cylindrical light source 13 is disposed along the end face of the light transmission plate 10. This light source 13 is provided with a light reflection material 14a formed by depositing silver by evaporation on a PET sheet or made of Al subjected to a mirror finishing treatment on the inside surface on its outer periphery. Further, the surface formed with the light diffusion patterns 11 is also provided with a similar light reflection material 14b. In such a case, the light is no longer reflected at the boundary face with an air layer and the exit light of this illumination device 9 is no longer attenuated at the time of reflecting the light by this light reflection material 14b and emitting the light. |
