Patent ID: 8174036

Claim:
A lighting device comprising a light source that emits incoherent light rays from at least one light emitting surface, and an optical element disposed after the light source and comprising a light exit surface and at least one reflector configured to reflect light rays emitted from the at least one light emitting surface in the direction of the light exit surface, wherein the light exit surface is arc-shaped in cross-section, the arc-shaped cross-sectional surface comprising two end points and an apex between the end points, and wherein a curvature of the light exit surface at the apex is spherical, and a curvature of the light exit surface at points corresponding to the curvature portion that is below each of the end points is less than spherical to reduce total internal reflection of light rays that are reflected by the at least one reflector, wherein the cross-sectional shape of the light exit surface is free of kinks over its entire length, and wherein the light source is a semiconductor body embedded in the optical element such that the semiconductor body is in direct contact with the optical element.