Patent ID: 8147093

Claim:
A compound light source comprising a plurality of component light sources, said compound light source being characterized by an output spectral measure and an average light intensity per component light source when each component light source is driven with a predetermined design current that is the same for each of said component light sources, said output spectral measure of said compound light source having a value within a spectral measure design range defined by first and second target spectral values, and said average light intensity per component light source being within an output intensity design range defined by first and second intensity values, said compound light source being unsatisfactory for its intended use if said output spectral measure is outside said spectral measure design range or said average light intensity per component light source is outside said output design range, said plurality of component light sources comprising: first and second component light sources, each component light source being characterized by said spectral measure and by an output light intensity when driven with said predetermined design current, said spectral measure of one of said first and second component light sources having a value outside of said spectral measure design range or said output intensity of one of said first and second component light sources being outside of said output intensity design range when said component light sources are driven with said predetermined current, wherein said first and second component light sources generate a combined light output that is characterized by said spectral measure and an average light intensity per component light source when driven with said predetermined current, said spectral measure of said combined light output having a value within said spectral measure design range and said average light intensity per component light source being within said output intensity design range when said component light sources are driven with said predetermined current.