Passive electrooptical display device having a reflector

摘要

It is proposed to configure the supplementary illumination of a display in the following way: located upstream of the actual display cell is a light-conducting film (13) which extends parallel to the plane of the cell and is composed of alternately juxtaposed lamellae (14) and intermediate layers (16). In common with the intermediate layers, the lamellae consist of light-transmitting materials of varying refractive index, and the interfaces (17) between these strips are inclined to the plane of the cell. On one of its narrow sides, the film receives artificial light which upon passing through the light-conducting film (13) on each of the abovementioned interfaces (17) is partially refracted and partially reflected - towards the cell. Since the light beams are somewhat attenuated at each interface, the reflected component should increase with each reflection given a particularly uniform illumination of the display field. The proposed solution is preferably applied in liquid crystal displays, and is always useful when there is a requirement for a compact display which can also be read off effectively from oblique directions. <IMAGE>