BAR SHAPE LIGHT GUIDE, LIGHTING UNIT, AND IMAGE READING DEVICE

摘要

PPROBLEM TO BE SOLVED: To provide a rod-shape light guide in which the illuminance of light emitted from an emitting face formed along the longitudinal direction is uniform. PSOLUTION: The rod-shape light guide 12 exposes the emitting face 12a from a white case 11 and has a pattern 14 for diffusing and reflecting light at the bottom face opposed to the emitting face. The pattern 14 is formed of white paint or a fine concavo-convex. Further, the end face 15 on the opposite side to the incident side of the rod-shape light guide 12 is made into a cube corner reflector shape. That is, the end face 15 is made into a mountain shape by mirror-finished flat surfaces 15a, 15b, and the flat surfaces 15a, 15b are inclined to an angle in which the incident angle θ of the light which has advanced in parallel with the longitudinal direction of the rod-shape light guide 12 in the light guide 12 becomes smaller than a critical angle. PCOPYRIGHT: (C)2006,JPO&NCIPI