Patent ID: 7482760

Claim:
A light-emitting element driving apparatus for driving two or more strings of one or more light-emitting elements, said apparatus comprising: a) one or more control signal generators for generating two or more original control signals; b) one or more scaling signal generators for generating one or more scaling signals; c) one or more coupling means, a particular coupling means receiving one of the original control signals and a particular scaling signal, each coupling means generating an effective control signal for control of a particular string by coupling the received scaling signal to the received original control signal; and d) switching means associated with each string, the switching means adapted for connection to a power source, and each switching means responsive to a particular control signal for controlling power supplied to a particular string, wherein the particular control signal is either one of the two or more original control signals or the effective control signal generated by one of the one or more coupling means; thereby driving said two or more strings of one or more light-emitting elements.