Display device employing current-driven type light-emitting elements and method of driving same

A method of driving a display device,

• said display device including
• a plurality of red pixels each provided with a current-driven type red-light-emitting element, a switching transistor, and a storage capacitance element coupled to said switching transistor,
• a plurality of green pixels each provided with a current-driven type green-light-emitting element, a switching transistor, and a storage capacitance element coupled to said switching transistor, and
• a plurality of blue pixels each provided with a current-driven type blue-light-emitting element, a switching transistor, and a storage capacitance element coupled to said switching transistor,
• said method comprising:
• writing a video signal voltage into said storage capacitance element of a respective one of said red, green, and blue pixels 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 in a state in which all of said current-driven type red-light-emitting, green-light-emitting, and blue-light-emitting elements cease to emit light, during a first portion of one frame period at a beginning thereof;
• and
• then ceasing to apply said scanning drive signal on said gate electrode of said switching transistor of each of said red, green, and blue pixels and operating said respective one of said red-light-emitting, green-light-emitting, and blue-light-emitting elements to emit light during at least one portion of said one frame period succeeding said first portion;
• wherein each of said at least one portion of said one frame period is determined by light emission characteristics associated with said respective one of said red-light-emitting, green-light-emitting, and blue-light-emitting elements, and also is determined by one of said video signal voltage stored in said storage capacitance element associated with said respective one of said red pixels, green, and blue pixels.

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.

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 an inverter circuit having an output terminal thereof coupled 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 between said switching transistor and an input terminal of said inverter circuit;
• a first circuit for short-circuiting between said input and output terminals of said inverter circuit of each of said red, green and blue pixels during a first portion of one frame period at a beginning thereof;
• a second circuit for writing a video signal voltage into said storage capacitance element of a respective one of said red, green, and blue pixels 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, during a second portion of said one frame period succeeding said first portion;
• and
• a third circuit for supplying at least one ramp-shaped gray scale control voltage varying from a first voltage of a first level to a second voltage of a second level different from said first level to said first terminal of said storage capacitance element of a respective one of said red, green, and blue pixels during a third portion of said one frame period succeeding said second portion;
• wherein a waveform of each of said at least one ramp-shaped gray scale control 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.

A method of driving a display device having a plurality of pixels each provided with a current-driven type light-emitting element,

• said method comprising:
• writing a video signal voltage into a respective one of said plurality of pixels in a state in which all of said current-driven type light-emitting elements cease to emit light, during a first portion of one frame period at a beginning thereof;
• and
• then operating said current-driven type light-emitting element of a respective one of said plurality of pixels to emit light during at least one portion of said one frame period succeeding said first portion;
• wherein each of said at least one portion of said one frame period is determined by said video signal voltage associated with said respective one of said plurality of pixels.

A method of driving a display device,

• said display device including a plurality of pixels each provided with a current-driven type light-emitting element, a switching transistor, and a storage capacitance element coupled to said switching transistor,
• said method comprising:
• writing a video signal voltage into said storage capacitance element of a respective one of said plurality of pixels by applying a scanning drive signal on a gate electrode of said switching transistor of said respective one of said plurality of pixels in a state in which all of said plurality of current-driven type light-emitting elements cease to emit light, during a first portion of one frame period at a beginning thereof;
• and
• then ceasing to apply said scanning drive signal on said gate electrode of said switching transistor of said respective one of said plurality of pixels and operating said respective one of said plurality of light-emitting elements to emit light during at least one portion of said one frame period succeeding said first portion;
• wherein each of said at least one portion of said one frame period is determined by said video signal voltage stored in said storage capacitance element associated with said respective one of said plurality of pixels.

A display device comprising:

• a plurality of pixels,
• each of said pixels being provided with a current-driven type light-emitting element, a drive transistor for supplying a drive current to said current-driven type light-emitting element, 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 plurality of 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 plurality of pixels;
• and
• a second circuit for supplying, as said gray scale control voltage, a first voltage of a first level for turning off said drive transistor in said respective one of said plurality of pixels 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.

A display device comprising:

• a plurality of pixels,
• each of said plurality of pixels being provided with a current-driven type light-emitting element, an inverter circuit having an output terminal thereof coupled to said current-driven type light-emitting elements, a switching transistor, a storage capacitance element coupled between said switching transistor and an input terminal of said inverter circuit;
• a first circuit for short-circuiting between said input and output terminals of said inverter circuit of each of said plurality of pixels during a first portion of one frame period at a beginning thereof;
• a second circuit for writing a video signal voltage into said storage capacitance element of a respective one of said plurality of pixels by applying a scanning drive signal on a gate electrode of said switching transistor of said respective one of said plurality of pixels, during a second portion of said one frame period succeeding said first portion;
• a third circuit for supplying at least one ramp-shaped gray scale control voltage varying from a first voltage of a first level to a second voltage of a second level different from said first level to said first terminal of said storage capacitance element of a respective one of said plurality of pixels during a third portion of said one frame period succeeding said second portion.