Patent ID: 6310590
Filing Date: 2001-10-30
Classification: G01R,G09G

Abstract:
A method for continuously controlling color of a variable color display device, which includes a plurality of display areas arranged in a pattern for exhibiting, upon selective activation, a plurality of display units, each said display area including a first light emitting diode for emitting, when forwardly biased, light signals of a first primary color, a second light emitting diode for emitting, when forwardly biased, light signals of a second primary color, and means for combining said light signals in said display area to obtain a light signal of a composite color, the method comprising:repeatedly defining a cycle by developing a start signal at the beginning of each said cycle;receiving n-bit data representing in value the portions of a first primary color, where n is an integer having value at least 2;developing an end signal timed, in relation to said start signal, in accordance with the value of said data;activating a selective plurality of said display areas for exhibiting a selected display unit;developing a stable signal of a first logic level in response to said start signal and a stable signal of an opposite logic level in response to said end signal;applying a first control signal, in accordance with said stable signal of said first logic level, for forwardly biasing said first light emitting diodes in the activated display areas, andapplying a second control signal, in accordance with said stable signal of said opposite logic level, for forwardly biasing said second light emitting diodes in the activated display areas.