Light guide for modular power lighting device - has converging converging concave-convex lens and mirror reflector surrounding point light source

摘要

The light guide transmits radiation from a paint luminous source across a modular power lighting device. The optical system has two parts: a convergent element (1) situated at the centre of a plate with parallel faces (2), and a concave mirror (3) associated with a plane mirror (4) to create a reflector which surrounds the luminous source. The convergent element is a thick concavo-convex lens with spherical faces, the radius of curvature of the concave face (6) being greater than the radius of curvature of the convex face (7). The parallel faced plate is supported on the rim of the reflector such that the comcavo-convex lens penetrates into the volume enclosed by the reflector. The concave mirror has a parabolic portion (3a) for its support part and an ellipsoidal portion (36) near the luminous source. It consists of a moulded plastic (9) covered on its interior face by a reflecting film (10). The plane mirror, which lies behind the luminous source consists of a reflecting layer covering a disc (11) created in a printed circuit (12). The device is used to route indication e.g. at a crossroads or for rear lights or direction indicators on cars.