OPTICAL DEVICE, LENS, LIGHTING DEVICE, SYSTEM AND METHOD

摘要

An optical device comprising a first surface with a plurality of micro sized facets, each facet having a respective orientation. Said plurality of facets having an optical axis which extends parallel to the normal vector to an average orientation of all said respective orientations. The plurality of facets comprising at least a first and a second group of facets, each group is formed by a respective number of at least twenty-five compactly arranged neighboring facets. Essentially each facet within a group has a tilt angleαt with the respective group optical axis, the tilt angle is within a range determined byαt <= 0.8 *αc, withαc being the critical angle for total internal reflection.