Method of driving liquid crystal display device
View Patent ↗A liquid crystal display device and a driving method for a liquid crystal display. The liquid crystal display device is formed to have thin film transistor conductive channels having an inverted “U”-shape. A shielding plate is provided to block incident light from reaching the conductive channels of the thin film transistors. This reduces or eliminates photo-induced leakage current and picture quality degradation. To prevent pixel electrode potential fluctuations caused by subsequent scan line drive signals, the liquid crystal display device is driven by scan signals that are sequentially applied from the mth gate line up to the first gate line.
1. A method of driving a liquid crystal display device comprised of gate lines G 1 through G M , comprising:
providing gate lines G 1 through G M arranged at regular intervals on a substrate;
providing data lines arranged at regular intervals so as to cross the gate liens;
providing a thin film transistor in an unit liquid crystal cell defined by the gate lines and the data lines,
wherein the thin film transistor includes a gate electrode that extends in a predetermined direction from the gate line, a semiconductor layer over the gate electrode, a source electrode that extends over the semiconductor layer from the date line and a drain electrode,
wherein a conductive channel has an inverted “U” shape and
wherein light at an incident direction of the inverted “U” shaped conductive channel is blocked by a shielding plate over an upper portion of the thin film transistor;
providing a storage capacitor for the thin film transistor on a pth gate line,
wherein the storage capacitor includes a first electrode that is part of a p+1th gate line, a gate insulation film and a storage electrode that is connected to a pixel electrode over the p+1th gate line; and
sequentially applying a gate signal voltage pulse to the p+1 gate line, the pth gate line and a p−1 gate line,
wherein p+1 is less than or equal to M(M=2, 3 . . . interger), and
wherein p−1 is greater than or equal to 1.
2. The method of driving a liquid crystal display device of claim 1 , wherein each “U” shaped conductive channel formed by applying a gate signal voltage pulse to the pth gate line charges the storage capacitor disposed over the p+1th gate line.
3. The method of driving a liquid crystal display device of claim 2 , wherein the charge of each storage capacitor is not discharged by photo-induced leakage current.
4. The method of driving a liquid crystal display device of claim 2 , further comprising providing a translucent reflection electrode at marginal portions of the unit liquid crystal cell and on a passivation film, wherein the reflection electrode formed over the upper portion of the thin film transistor serves as the shielding plate for blocking incident light from reaching the conductive channel.