Patent ID: 7116287

Claim:
Apparatus for driving a cholesteric liquid crystal display comprising: a) the display including cholesteric liquid crystals having a first planar reflective state and a second transparent focal conic state, which are respectively responsive to different applied fields; b) an addressing structure having rows and columns of conductors arranged so that when a column and a row overlap, they define a selectable pixel or segment to be viewable or non-viewable; c) a switching mechanism operatively coupled to the addressing structure, the switching mechanism being operative to output either a first fixed voltage and a fixed second voltage; d) at least one column voltage divider for each column and at least one row voltage divider for each row within the addressing structure, the row and column voltage dividers being responsive to the first and second fixed voltages to provide one of two selectable voltages for each column and one of two selectable voltages for each row; and e) a selection circuit operatively coupled to the switching mechanism that selects one of either the first or second voltages in accordance with a predetermined scheme wherein the column voltage divider provides one of two voltages for each column and the row voltage divider provides one of two voltages for each row so that a particular pixel or segment will have an applied voltage that will cause the pixel or segment to selectively be in either a transparent or a reflective state.