Patent ID: 7497581

Claim:
An illumination system, comprising: a light source, wherein said light source further comprises an emitting layer and a reflecting layer, wherein said emitting layer emits light of a first wavelength range and wherein the total light-emitting area of said light source is area A S ; a wavelength conversion layer, wherein said wavelength conversion layer converts a portion of said light of a first wavelength range into light of a second wavelength range, different from said light of a first wavelength range, and wherein said wavelength conversion layer is a solid phosphor layer; a light-recycling envelope, wherein said light-recycling envelope is separate from said wavelength conversion layer, wherein said light-recycling envelope at least partially encloses said light source and said wavelength conversion layer, wherein the maximum cross-sectional area of said light-recycling envelope is area A E , wherein said light-recycling envelope has reflectivity R E and wherein said light-recycling envelope reflects and recycles part of said light of a first wavelength range and part of said light of a second wavelength range back to said reflecting layer or to said wavelength conversion layer as recycled light; and at least one light output aperture, wherein said at least one light output aperture is located in a surface of said light-recycling envelope, wherein the total light output aperture area is area A O , wherein said light source and said wavelength conversion layer and said light-recycling envelope direct at least a fraction of said light of a first wavelength range and at least a fraction of said light of a second wavelength range out of said light-recycling envelope through said at least one light output aperture as incoherent light and wherein said recycled light reflected from said light-recycling envelope produces increased light output brightness through said at least one light output aperture.