Driving circuit and method for liquid crystal display panel
AssigneeHannstar Display Corp.
InventorsPo-Sheng Shih, Seok-Lyul Lee
Life of this patent
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Abstract
A driving circuit and a driving method can drive an LCD panel to display imagines. Storages capacitors of pixels connected with each scanning line are connected with an AC signal source. The AC signal source can vary the potential of its signal in harmony with the polarity inversion of a pixel during a vertical scanning period. Due to a capacitively coupled effect, a coupled voltage induced by the variation in the potential of the signal changes the potential of a pixel electrode so as to speed up the alternation in the electrical field of an LC capacitor.
Claims21
A driving circuit for a liquid crystal display panel, comprising:
- a plurality of data lines;
- a plurality of scanning lines;
- a common electrode;
- a plurality of pixels positioned on intersections of the scanning lines and the data lines, each of the plurality of pixels including:
- a thin film transistor whose gate electrode, source electrode and drain electrode are separately connected to the scanning line, the data line and a pixel electrode;
- a liquid crystal capacitor whose two terminals are separately connected to the pixel electrode and the common electrode;
- and
- a first storage capacitor having one terminal electrically connected to the pixel electrode and having another terminal electrically connected to a modulation signal source providing modulation signals to the first storage capacitors of the pixels so as to generate corresponding coupled voltages.
A driving method for a liquid crystal display panel that includes a plurality of matrix-arranged pixels positioned on intersections of a plurality of scanning line and a plurality of data lines, each pixels having a thin film transistor whose gate electrode, source electrode and drain electrode are separately connected to the scanning line, the data line and a pixel electrode and a first storage capacitor whose one terminal electrically connected to the pixel electrode and another terminal electrically connected to a modulation signal source, comprising the steps of:
- starting a scanning period for the scanning line;
- writing sequentially a modulation signal provided by the modulation signal source connected to the pixels positioned on the scanning line into each of the first storage capacitors;
- inducing a coupled voltage to change the potential of the pixel electrode from an initial level to a first level through the modulation signal applied to the first storage capacitor, wherein the variation of the potential of the pixel electrode is equal to the coupled voltage;
- turning on sequentially the thin film transistors of the pixels on the scanning line by a scanning signal;
- writing a data signal from the data line into the pixel electrode to change the potential of the pixel electrode from the first level to a second level, wherein the variation of the potential of the pixel electrode is equal to the potential of the data signal;
- and
- ending the scanning period for the scanning line.
A driving method for a liquid crystal display panel that includes a plurality of matrix-arranged pixels positioned on intersections of a plurality of scanning line and a plurality of data lines, each pixels having a thin film transistor whose gate electrode, source electrode and drain electrode are separately connected to the scanning line, the data line and a pixel electrode and a first storage capacitor whose one terminal electrically connected to the pixel electrode and another terminal electrically connected to a modulation signal source, comprising the steps of:
- starting a scanning period for the scanning line;
- turning on sequentially the thin film transistors of the pixels on the scanning line by a scanning signal;
- writing a data signal from the data line into the pixel electrode to change the potential of the pixel electrode from an initial level to a first level, wherein the variation of the potential of the pixel electrode is equal to the potential of the data signal;
- writing sequentially a modulation signal provided by the modulation signal source connected to the pixels positioned on the scanning line into each of the first storage capacitors;
- inducing a coupled voltage to change the potential of the pixel electrode from the first level to a second level through the modulation signal applied to the first storage capacitor, wherein the variation of the potential of the pixel electrode is equal to the coupled voltage;
- and
- ending the scanning period for the scanning line.
Dependencies are inferred from the claim text.