Patent ID: 7731389

Claim:
A light source for producing a spectral output at an output intensity, the light source comprising: one or more light-emitting clusters of a first type, each one of which comprising a first combination of one or more light-emitting elements in each of at least a first, a second and a third colour; one or more light-emitting clusters of a second type, each one of which comprising a second combination of one or more light emitting elements in one or more of said first, said second and said third colour, and wherein each of said light-emitting clusters of said second type comprises one or more light-emitting elements in each of said first, said second and said third colour; and a driving element for driving said light-emitting clusters; wherein, when driven at the output intensity, the spectral output is provided by a combined spectral output of said one or more light-emitting clusters of said first type and said one or more light-emitting clusters of said second type.