Color Mixing and Desaturation with Reduced Number of Converters

A method for biasing two or more light sources comprising:

• generating a bias signal with a bias signal generator;
• providing the bias signal having a first magnitude from a bias signal generator to a first light source and a second light source which establishes a first light source cathode voltage and a second light source cathode voltage;
• comparing the first light source cathode voltage to the second light source cathode voltage or to a reference voltage;
• responsive to the comparing, generating one or more switch control signals;
• providing the one or more switch control signals to a switch to present the bias signal generator with a feedback signal or a proportional representation of the feedback signal;
• and
• responsive to the feedback signal or a proportional representation of the feedback signal generating a bias signal having a second magnitude different the first magnitude with the bias signal generator.

A system having two or more light sources configured to generate a color mixed optical signal output comprising:

• one or more bias signal sources configured to generate a bias signal, the bias signal set by a feedback signal there being a fewer number of bias signal sources than light sources;
• two or more channels, wherein each channel comprises:
• a light source having a bias set by the bias signal and a light source headroom value associated with each light source;
• a driver connected to the light source which is responsive to a control signal to establish a current through the light source to generate an optical output signal;
• a comparator configured to compare the headroom value to a reference value to generate a comparator output;
• and
• a controller configured to receive the comparator output from one or more channels to generate feedback signal to the one or more bias sources.