In a device composed of a light guide plate, the light emitted from a light source is guided by components in a direction parallel to the main surface of the plate and issues from projections (3) formed on the surface of the plate. The smooth surface of the plate is coated with a continuous, transparent,...http://www.google.es/patents/US5022728?utm_source=gb-gplus-sharePatente US5022728 - Device composed of a light guide plate
