Data line drivers with common reference ramp display

A comparator for a data line driver of a display device, comprising:

• a first transistor;
• a first capacitance coupled to a control terminal of said first transistor to form a comparator;
• a first switching arrangement coupled to said first capacitance for storing a charge in said first capacitance that automatically compensates for variations in a triggering level of said first transistor;
• a reference ramp generator for generating a reference ramp signal;
• a second capacitance coupled to said reference ramp generator and to said first capacitance for capacitively coupling said reference ramp signal to said control terminal via each of said first and second capacitances;
• a source of a video signal;
• and
• a second switching arrangement coupled to said second capacitance for storing said video signal in said second capacitance.

A video apparatus for developing a signal containing picture information in pixels of a display device that are arranged in columns, comprising:

• a reference ramp generator for generating a reference ramp signal;
• a plurality of data line drivers responsive to said video signal for applying said video signal to said pixels, a given data line driver of said plurality of line drivers being coupled to pixels arranged in a corresponding column that is associated with said given data line driver, said given data line driver including:
• a first transistor;
• a capacitance for capacitively coupling said reference ramp generator to an input of said first transistor;
• a source of a video signal;
• a first switching arrangement responsive to said video signal and coupled to said capacitance via a terminal of said capacitance that is remote from said reference ramp generator relative to a second terminal of said capacitance for storing said video signal in said capacitance;
• a source of a data ramp signal;
• a switching transistor responsive to an output signal developed at an output of said first transistor for applying said data ramp signal to said pixels of said column that is associated with said given data line driver, during a controllable portion of a period of said data ramp signal that varies in accordance with said video signal.

Apparatus for applying video signal to a column electrode of a display device, comprising:

• a source of a video signal;
• a reference ramp generator for generating a reference ramp signal;
• a data line driver responsive to said video signal for applying said video signal to said column electrode, said data line driver including:
• a first transistor;
• a capacitance having a first terminal coupled to said reference ramp generator and a second terminal coupled to a control terminal of said transistor;
• a first switching arrangement coupled to said video signal source and to said capacitance via said second terminal of said capacitance for selectively applying said video signal to said capacitance;
• a source of a data ramp signal;
• and
• a switching transistor responsive to an output signal
• developed at an output terminal of said first transistor for applying said data ramp signal to said column electrode during a controllable portion of a period of said data ramp signal that varies in accordance with a signal that is developed at said control terminal of said first transistor.