Patent ID: 6466194
Filing Date: 2002-10-15
Classification: G02F,G09G

Abstract:
A column driver circuit for a display device comprising:a source of data signal; a source of switching signal having first, second and third states, the second state having a potential greater than the first state and the third state having a potential greater than the second state; a first transistor having a principal conduction path between first and second electrodes and a control electrode, the first electrode being coupled to the source of data signal, for applying, responsive to a control signal applied to the control electrode, the data signal to a data line which is coupled to the second electrode and associated with the column of the display device; a second transistor having a principal conduction path between first and second electrodes and a control electrode, the first and second electrodes of the second transistor being coupled between a source of reference potential and the control electrode of the first transistor; a capacitor, coupled between the control electrode of the second transistor and the source of switching signal; and means for selectively applying a control potential to the control electrode of the second transistor while the switching signal is in the second state, the control potential causing the transistor to apply the first reference potential to the control electrode of the first transistor, wherein a bias potential substantially equal to the control potential minus a potential corresponding to the switching signal in the second state is stored on the capacitor; whereby the second transistor is controlled to selectively apply the first reference potential to the control electrode of the first transistor responsive to the switching signal switching from the first state to the third state.