| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a light guide emitting light from an emitting face of the light guide so that dependency of an emitting angle becomes small, and also to provide an illumination switching device using the light guide. <P>SOLUTION: The light guide 6 is provided with a light receiving face 61 which is formed of a transmission material and receives light from a light source, and an emitting face 62 which is arranged by making it face the light receiving face 61 and emits light received in the light receiving face. The emitting face 62 has an almost smooth face and is set to be smaller than the area of the light receiving face 61. Protrusions and recesses 63 having inclined faces whose inclined angles θ with respect to a vertical line erected on the light receiving face 61 are 25° and which incline within 35° are vertically, laterally and periodically formed. Tops 63a and troughs 63b in the protrusions and recesses 63 form a curved surface (R=about 0.2mm). <P>COPYRIGHT: (C)2005,JPO&NCIPI |
