Patent ID: 7388565

Claim:
An LCD display driver providing adjustable contrast independently of multiplexing requirements, comprising: a COM line driver generating as many COM signals as are required by a multiplexing level, each COM signal being produced in a particular time slot of a repeating signal frame containing multiple time slots, each time slot corresponding to a particular COM signal, and each COM signal containing one or more active periods and one or more inactive periods, the relative time proportions of the active periods and the inactive periods being adjustable, and a SEGMENT line driver generating active signals relative to a corresponding time-slot such that required display segments are turned-on while remaining display segments are turned off and every LCD segment experiences an AC voltage signal with an essentially zero DC component, wherein the logic level of the SEGMENT signals and the relative active time to inactive time for the SEGMENT and COM signals is adjustable to increase or decrease a root mean square (RMS) voltage level across the LCD elements as desired.