Binary drive circuitry for matrix-addressed liquid crystal display

Claim 2

A matrix-addressed liquid crystal display system including: an electrically controlled liquid crystal display divided into modules, each module having a common electrode and a plurality of opposed segment electrodes between which potential gradients may be selectively established through the liquid crystal; means for time-division-mulitplex addressing the common electrodes of said modules during sequential addressing intervals, including means for applying a first phase of square-wave signal of a predetermined amplitude and a first square-wave repetition rate to the common electrode of the selected one of said modules during each addressing interval; means for parallelly addressing the segment electrodes of said modules with a second phase of square-wave signal of said predetermined amplitude and said first square-wave repetition rate during each of said addressing intervals, or with first phase of square-wave signal of said predetermined amplitude and first square-wave repetition rate, depending on whether or not the common electrode of a selected one of said modules is to have a field between it and the respective ones of those segment electrodes opposed to it, said first and second phases of said first square-wave repetition rate being opposite each other; and the improvement wherein said means for time-division-multiplex addressing the common electrodes of said modules during sequential addressing intervals also comprises: means for applying to the common electrode of each non-selected one of said modules a square-wave signal of said predetermined amplitude, but of a second square-wave repetition rate which is an even harmonic of that applied to the common electrode of said selected module.

Claim 3

A matrix-addressed liquid crystal display system as set forth in claim 1 wherein said even harmonic is the second harmonic.

Claim 6

A matrix-addressed liquid crystal display system including an electrically controlled liquid crystal display divided into modules, each module having a common electrode and a plurality of opposed segment electrodes between which potential gradients may be selectively established through the liquid crystal; means for time-division-multiplex addressing the common electrodes of said modules during sequential addressing intervals; means, included in said means for time-division-multiplex addressing, for applying a first binary-valued signal of a predetermined amplitude between high and low voltages to the common electrode of the selected one of said modules during each addressing interval, which first binary-valued signal is high during half the time of each addressing interval and otherwise low; means, included in said means for time-division-multiplex addressing, for applying to the common electrode of each non-selected one of said modules a second binary-valued signal of said predetermined amplitude, between said high and said low voltages, which second binary-valued signal is at said high voltage half the time said first binary-valued signal is at said high voltage, is at said low voltage the other portion of the time said first binary-valued signal is at said high voltage, is at said low voltage half the time said first binary-valued signal is at said low voltage, and is at said high voltage the other portion of the time said first binary-valued signal is at said low voltage; and means for parallelly addressing the segment electrodes of said modules with the complement of said first binary-valued signal of said predetermined amplitude during each of said addressing intervals, or with said first binary-valued signal of said predetermined amplitude itself, depending on whether or not the common electrode of a selected one of said modules is to have a potential gradient between it and the respective ones of those segments electrodes opposed to it.

Claim 7

A matrix-addressed liquid crystal display system including an electrically controlled liquid crystal display divided into modules, each module having a common electrode and a plurality of opposed segment electrodes between which potential gradients may be selectively established through the liquid crystal; means for time-division-multiplex addressing the common electrodes of said modules during sequential addressing intervals; means, included in said means for time-division-multiplex addressing, for applying a first binary-valued signal of a predetermined amplitude between high and low voltages to the common electrode of the selected one of said modules during each addressing interval, which first binary-valued signal is high during half the time of each addressing interval and otherwise low; means, included in said means for time-division-multiplex addressing, for applying to the common electrode of each non-selected one of said modules a second binary-valued signal of said predetermined amplitude, between said high and said low voltages, which second binary-valued signal is at said high voltage half the time said first binary-valued signal is at said high voltage, is at said low voltage the other portion of the time said first binary-valued signal is at said high voltage, is at said low voltage half the time said first binary-valued signal is at said low voltage, and is at said high voltage the other portion of the time said first binary-valued signal is at said low voltage; and means for parallelly addressing the segment electrodes of said modules with the complement of said first binary-valued signal of said predetermined amplitude during each of said addressing intervals, or with said first binary-valued signal of said predetermined amplitude itself, depending on whether or not the common electrode of a selected one of said modules is to have a potential gradient between it and the respective ones of those segments electrodes opposed to it.