Patent ID: 8912717

Claim:
An illumination device comprising a phosphor element for a conversion of pump light to converted light, a pump light source comprising an exit surface for pump light, which has a main propagation direction formed as the focal point of propagation directions weighted according to the power in relation to the exit surface, and an optical system comprising a reflection surface, which is designed for the purpose of redirecting at least a part of the pump light propagating in the main propagation direction such that it is incident on the phosphor element with a directional component opposing the main propagation direction, which phosphor element then emits converted light with a directional component oriented parallel to the main propagation direction and is thus operated in reflection, wherein at least one region of the reflection surface extends transversely to the main propagation direction and is designed for the purpose of at least partially transmitting the converted light, wherein the optical system has a transparent body comprising a curved interface facing away from the phosphor element, wherein the transparent body has a first index of refraction and borders with said interface on a medium having a lesser second index of refraction, so that the interface is at least partially implemented as a reflection surface and the redirection is performed by a total reflection, and wherein the transparent body has an index of refraction n tk and the interface is curved such that, in a sectional plane which is parallel to the main propagation direction and extends through the exit surface, a curved line corresponding to the interface is implemented with respect to a point lying in the exit surface such that there are at least two connecting lines from the point to the curved line, wherein each line encloses an angle between each connecting line and the curved line, wherein each angle satisfies angle≦arccos (1/n tk ) therewith, wherein the at least two connecting lines together subtend at least an angle range of 30° .