Patent ID: 6297790
Filing Date: 2001-10-02
Classification: G09G

Abstract:
A method for determining values of digital-to-analog converters for steering of the viewing angle of a liquid crystal display, said method comprising:providing a first set of digital-to-analog converters that are in electrical communication with at least one light source;providing a second set of digital-to-analog converters that are in electrical communication with said at least one light source;arranging said digital-to-analog converters in pairs, each of said pairs comprising a respective one of said digital-to-analog converters of said first set and a respective one of said digital-to-analog converters of said second set;driving said at least one light source with said first set of digital-to-analog converters to produce a first light output;driving said at least one light source with said second set of digital-to-analog converters to produce a second light output;determining a relationship of said pairs of said digital-to-analog converters such that said first light output and said second light output are balanced;driving said at least one light source with said first set and said second set of digital-to-analog converters to produce a third light output;determining an equation approximating said third light output;providing a desired viewing angle and a desired input gamma correction;determining a gamma correction of said relationship of said pairs of said digital-to-analog converters, said gamma correction being a function of said desired input gamma correction;determining an offset caused by said desired viewing angle, said offset being a level of light output as a function of said desired viewing angle;determining a center number, said center number being a percentage of said third light output at a predetermined point of said equation taking into account said offset;determining a first value of a first one of said digital-to-analog converters in each of said pairs, said first value being a function of said gamma correction, said offset, and said center number; anddetermining a second value of a second one of said digital-to-analog converters in each of said pairs, said second value being a function of said first value in each of said pairs.