Patent ID: 7138973

Claim:
A display driver for driving a passive matrix liquid crystal display panel using cholesteric liquid crystal material comprising a shift register for shifting a row data or column data inputted to the driver; a data latch circuit for latching the row data or column data from the shift register; and a drive voltage select/output circuit for selecting at least one of a plurality of unipolar voltage supplies and outputting a row drive voltage or column drive voltage to form an alternated drive voltage which activates picture elements of the liquid crystal panel the drive voltage select/output circuit including: a select circuit for generating the select signal to select at least one of the plurality of voltage supplies by the row data or column data latched by the data latch circuit, and a voltage output circuit for outputting the row drive voltage or column drive voltage by the voltage supplies selected by the select signal; wherein the display driver is operated in a row mode or column mode which is set by inputting a row/column mode signal to the select circuit, and wherein the select circuit selects by a conventional/dynamic mode signal inputted thereto either of a dynamic drive in which the transition of cholesteric liquid crystal texture is controlled by a series of stages or a conventional drive in which the transition of cholesteric liquid crystal texture is controlled by one stage.