Patent ID: 9719655
Date: 2017-08-01
CPC Classifications: F21S,F21W,G02B,Y10T

Claim:
1. Alighting device comprising at least one light source and at least one optical device, the optical device comprising a first surface with a plurality of micro sized facets having a size in between 25 μm to 250 μm, 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, wherein during operation, the lighting device issues a beam of light onto the optical device, each group of facets is arranged to constitute a respective, mutually identical, whole pattern, that each facet in a respective group of facets is configured to redirect a sub-beam of the beam of light to form a sub-pattern of said respective whole pattern, and that the respective whole patterns are mutually superpositioned; wherein the superpositioned whole patterns are mutually shifted by a small shift δ, resulting in a superposition of the respective whole images of in between 50% to 95%.