US Patent 7441929 Lighting unit having a plurality of curved surface elements

The invention relates to a lighting unit having at least one light source and at least one light guide following the source and at least partially surrounding it, said light guide including at least one light exit surface facing away from the source and at least approximately located centrally, surrounded by at least one externally located light exit surface. In addition, at least one externally located light exit surface comprises a plurality of surface elements adjacent to each other with or without offset. These surface elements are surface regions of curved solids.