US Patent 9480108 Solid-state light source

In one aspect, a light source module includes one or more light emitters of a first color forming a first color group, one or more light emitters of a second color forming a second color group, the one or more light emitters of the second color group connected in series to the one or more light emitters of the first color group, a second color group adjustment circuit connected in parallel to the one or more light emitters of the second color group, the second color group adjustment circuit configured to adjust one or both of color and intensity of output light of the second color group, and a current source connected in series to solid-state color emitters of the first and the second color groups.