Patent ID: 7071906

Claim:
A display device comprising: a plurality of red pixels each provided with a current-driven type red-light-emitting element; a plurality of green pixels each provided with a current-driven type green-light-emitting element; a plurality of blue pixels each provided with a current-driven type blue-light-emitting element, each of said red, green and blue pixels being provided with a drive transistor for supplying a drive current to a corresponding one of said current-driven type red-light-emitting, green-light-emitting, and blue-light-emitting elements, a switching transistor, a storage capacitance element coupled to said switching transistor, a comparator with an output terminal thereof coupled to a gate electrode of said drive transistor, a first input terminal of said comparator supplied with a voltage stored in said storage capacitance element and a second input terminal of said comparator supplied with a gray scale control voltage; a first circuit for writing a video signal voltage into said storage capacitance element of a respective one of said red, green, and blue pixels during a first portion of one frame period at a beginning thereof by applying a scanning drive signal on a gate electrode of said switching transistor of said respective one of said red, green, and blue pixels; and a second circuit for supplying, as said gray scale control voltage, a first voltage of a first level for turning off all of said drive transistors during said first portion of said one frame period, then at least one ramp voltage varying from said first voltage of said first level to a second voltage of a second level different from said first level during a second portion of said one frame period succeeding said first portion; wherein a waveform of each of said at least one ramp voltage is determined by light emission characteristics associated with a corresponding one of said current-driven type red-light-emitting, green-light-emitting, and blue-light-emitting elements.