Patent ID: 8044611

Claim:
An apparatus comprising: a shift register that sequentially stores light emission data input from a data input terminal and overflows the light emission data exceeding the storage capacity; a switch terminal that is adapted to receive a switch voltage; a detector that is coupled to the switch terminal and that compares the switch voltage to a predetermined voltage; a plurality of current output terminals, wherein each current output terminal is adapted to be coupled to an LED; and a plurality of LED drivers, wherein each LED driver is coupled to at least one of the current output terminals and to the detector, and wherein each LED driver that includes: a storage circuit that is coupled to the shift register and that stores light emission data from the shift register; a pulse width modulation (PWM) circuit that is coupled to the storage circuit; a selection circuit that is coupled to the storage circuit; a control circuit that is coupled to PWM circuit and the selection circuit; and a variable current circuit that is coupled to the control circuit and to its associated current output terminal.