Lighting apparatus with a light guiding body having projections in the shape of a trapezoid

摘要

A reflection layer is provided on a surface of a light guiding body on which projections are formed with intervals, except the side surfaces of the projections. A light emitting element is provided close to one end surface of a light guiding element. Most of the light from the light emitting element is input to the light guiding body through the light input surface. The light travels through the light guiding body to be output from the side surfaces of the projections. After passing through a directional change element, the light is input to the light receiving element in a direction substantially perpendicular to a light receiving element. Outside light passes through the light receiving element and is then input to a lighting apparatus. In the lighting apparatus, the outside light passes through the directional change element to be reflected by a reflection layer on the light-output- side surface of the light guiding body and then again passes perpendicularly through the directional change element toward the light receiving element. When the light passes through the light receiving element, a displayed image can be viewed. The reflection layer can reflect the light with a small loss. In addition, if the outside light is input at an angle of other than 90. degree. to the light receiving element at first, the light can be reflected by the reflection layer with a small loss.