Integrated multiplex drive system for a passive liquid crystal display (LCD) using modulated pulse widths

摘要

A method of multiplex driving a passive liquid crystal display (LCD) using a bi-level LCD multiplex driver for providing one or more bi-level waveforms on the ROW/common lines and COLUMN/segment lines of a multiplexed liquid crystal display (LCD). These waveforms drive the LCD display using binary data from display memory locations. At periodic intervals the machine state is advanced with the present state used to 1) look-up in a table the bi-level data to output on the ROW/commons, and 2) look-up memory locations associated with the active COLUMN/segments; and 3) to provide inverted COLUMN/segments data before sending the bi-level data to the COLUMN/segment lines of the LCD. The states advance four times the number of ROW/commons before being reset to the initial state and the waveforms repeated. Thus, the machine produces one ON/select voltage and one OFF/non-select voltage are provided to the LCD according to predetermined formulas.