초록 ▼

To provide for uniform output throughout the area of the light source, particularly to provide a background illuminating surface for liquid crystal display, an especially adapted for automotive application, the light-emitting surface is formed as a wedge-shaped body of transparent material, such as

To provide for uniform output throughout the area of the light source, particularly to provide a background illuminating surface for liquid crystal display, an especially adapted for automotive application, the light-emitting surface is formed as a wedge-shaped body of transparent material, such as Plexiglas, with light being coupled thereinto at the wider side surface, the bottom surface of the wedge-shaped body having, preferably, a reflective, light dispersing layer or coating applied thereto, for example in form of a white pigmented lacquer, white paper, a ceramic plate, or the like; an intermediate layer of light-transmissive material having an index of refraction less than the index of refraction of the body may be interposed between the surface of the body and the reflective coating of layer. The top surface of the body can be matte, for example formed by microgrooves extending transversely to the plane of the side surface through which light is coupled into the wedge-shaped body. The light can be coupled thereinto derived, for example, from an incandescent bulb.

대표청구항 ▼

Large-area light source comprising a light-transmissive body (1), a form of a thin wedge having an essentially flat, light-emitting surface and being of essentially rectangular cross section, adapted to be exposed to a visible radiation source at one side surface, the wedge shaped light transmissive

Large-area light source comprising a light-transmissive body (1), a form of a thin wedge having an essentially flat, light-emitting surface and being of essentially rectangular cross section, adapted to be exposed to a visible radiation source at one side surface, the wedge shaped light transmissive body has two major surfaces (2,3), which are inclined with respect to each other, one of said surface (2) forming the light-emitting surface. the side surface (4) which receives the visible radiation (A) is a surface which is angled off from said one, or light-emitting surface (2) and joins said one light-emitting major surface (2) to the other major surface (3) at an essentially right-angle junction with respect to said other major surface (3), and a thin, light-transmissive layer (7) is provided coating said other major surface (3) opposite the light-emitting surface of the wedge-shaped body (1), the optical index of refraction of said layer (7) being less than the optical index of refraction of the material of the wedge-shaped body (1); and a light-dispersing, light-reflecting pigment coating or layer (8) is provided, covering said light-transmissive coating or layer (7).