US Patent 7581862 Light guide element and light unit with light guide element

The invention concerns a light guide element whose cross-sectional surface widens continuously at least in areas from a light inlet surface to a light outlet surface, as well as a light unit with at least one LED as light source and with a light guide element. For this purpose the light guide element includes at least one area with a curved directrix, in which the curvature of the directrix in this area is constant or which the curvature of the directrix in this area diminishes with increasing cross section of the light guide element.