Bar-shaped light guide, beam lighting device using the bar-shaped light guide, and surface lighting device using the beam lighting device

摘要

This invention was made to reduce cost and the number of assembly processes and improve productivity by making viewing angle characteristics of light emitted from a light emitting surface even irrespective of a point in a bar-shaped light guide. A bar-shaped light guide of this invention comprises a light incident surface for receiving light emitted from a point light source, a light emitting surface, which is orthogonal to the light incident surface, for emitting light received on the light incident surface in a form of beam light, and a pattern surface made up of a side of the light incident surface and a side of the light emitting surface and having a plurality of grooves formed thereon. The plurality of grooves are regularly arranged on the pattern surface. An angle formed by the groove 106 and the side of the light emitting surface on a side of the point light source is 35-55°.