Rear indicating device for an automobile

摘要

A rear indicator device for an automobile arranged inwardly of and adjacent to a rear window. The device includes a light guide plate 2, a hologram 2 arranged in the light guide plate 2 and an irregular shaped prism having a first section having an apex angle phi 1 at which the light beam from a light source 5 is subjected to a refraction so that the light beam is flattened. The flattened beam is again introduced into the prism at a second section which is in face to face contact with the light guide plate 2, so that the light beam is transmitted inside the light guide plate 2 toward the hologram 3, whereat the light beam is introduced into the hologram at a predetermined angle of incidence, so that a horizontal light beam of a predetermined wave length is obtained in a rear direction of the automobile to indicate the braking of the automobile.