Patent ID: 7612942

Claim:
An illumination system comprising: a light source for emitting light, the light emitted from the light source including at least visible light and ultraviolet (UV) radiation; a diffuser positioned so as to receive light from the light source, the diffuser diffusing visible light received from the light source towards another element of the illumination system; wherein the diffuser comprises a glass substrate, with a light diffusing coating formed on an external surface of said glass substrate, the light diffusing coating comprising inorganic pigment particles mixed with frit; and wherein the diffuser has a diffusing property F(Q) of greater than 0.100 and a visible transmission of at least 57%, where F(Q) is defined by: F ( Q ) =1/[4({θmax−θmin}/ W ) 2 +1] wherein W is a half width at a half maximum value point of a illumination vs. diffusing angle plot, θmax is a maximum value of the illumination vs. diffusing angle plot, and θmin is a minimum of at least one of the tails of the illumination vs. diffusing angle plot, wherein the average particle size of the inorganic pigment particles is no greater than 0.5 microns, and the thickness of the diffusing coating is from about 1.0 to 7.0 microns.