Patent ID: 6647199
Filing Date: 2003-11-11
Classification: G02B,G04B,Y10S

Abstract:
A lighting apparatus, comprising:a device that emits light; an optical cavity formed by diffusive reflective surfaces, said cavity having an output region through which light from said cavity passes; said light emitting device being mounted to supply light to said cavity while being hidden from direct view through said output region, said cavity having a diffusely reflective surface area and said output region having an area, the ratio of said area of said output region to the sum of (i) said area of said output region and (ii) said surface area of said cavity being at least 0.05, said cavity having a depth and said output region having an edge-to-edge bisector dimension, the ratio of said depth to said bisector dimension being significantly less than 0.1; and an angular spectrum restrictor positioned to restrict output illumination through said output region to a predetermined range of angles.