LCD system having improved contrast ratio

A color display comprising:

• first and second optics;
• first, second and third display subassemblies disposed between said optics;
• each of said display subassemblies including a liquid crystal panel defining a plurality of independently operable pixels;
• at least two of said display subassemblies having different values of .DELTA.nd;
• first, second, third and fourth polarizers;
• the first display subassembly being disposed between the first and second polarizers;
• the second display subassembly being disposed between the second and third polarizers;
• the third display subassembly being disposed between the third and fourth polarizers;
• wherein at least two of the three liquid crystal panels comprise liquid crystal material having an inherent molecular twist angles in excess of 150 degrees, and wherein the first and fourth polarizers are colored a color other than black.

A high resolution display system having an improved contrast ratio comprising:

• at least a first and a second liquid crystal display panel;
• each of said panels comprising a first and a second glass substrate having a gap therebetween;
• said gap having liquid crystal material disposed therein;
• said liquid crystal material having a first twist angle in said first panel and a second twist angle in said second panel;
• said first substrate having a plurality of spaced row electrodes and said second substrate having a plurality of spaced column electrodes so as to form a matrix;
• said matrix substantially defining a plurality of active regions and a plurality of non-active regions whereby the transmitted luminance of said liquid crystal may be selectively controlled in said active regions;
• a clear non-birefringent material applied to one of said substrates only between said electrodes for decreasing the gap spacing between said first and second substrates in said non-active regions.

A display system having an liquid crystal display with a high contrast ratio;

• said display system comprising:
• at least a first and a second liquid crystal display panel;
• each of said panels comprising a first and a second substrate having a gap therebetween;
• said gap having liquid crystal material disposed therein;
• said first substrate having a plurality of spaced row electrodes and said second substrate having a plurality of spaced column electrodes so as to form a matrix;
• said matrix substantially defining a plurality of active regions and a plurality of non-active regions of liquid crystal material whereby the transmitted luminance of said liquid crystal may be selectively controlled in said active regions;
• said first substrate further having a plurality of compensator row electrodes placed between said row electrodes;
• said compensator row electrodes electrically connected in parallel and biased at a non-select voltage so as to provide a color display system with a high contrast ratio.

A high resolution display system having an improved contrast ratio comprising:

• a first and a second liquid crystal display panel, each having liquid crystal material confined between a pair of spaced substrates;
• each of said panels having a plurality of active regions and a plurality of non-active regions defined by active row and column electrodes for selectively controlling the birefringent properties of said liquid crystal material in said active regions;
• said liquid crystal material confined in said first panel having an equal twist angle and an opposite twist sense relative to the liquid crystal material confined in said second panel;
• means for decreasing the .DELTA.nd product of the liquid crystal material only in said non-active regions.

A color display apparatus comprising:

• first and second optically aligned assemblies, each including a liquid crystal panel exhibiting a birefringent effect that varies in response to an excitation signal applied to it;
• wherein said first and second assemblies are tuned so that a birefringent effect exhibited by said first assembly when a first signal is applied thereto differs from a birefringent effect exhibited by said second assembly when the same first signal is applied thereto;
• a third assembly including a liquid crystal panel optically aligned with said first and second assemblies and operable to increase the contrast ratio of said apparatus responsive to an excitation signal applied to it;
• first and second polarizers sandwiched about said assemblies;
• and
• third and fourth polarizers interposed between said assemblies.