US Patent 7750958 Pixel structure

A method is disclosed for applying a first voltage to a back plate of a memory capacitor of a pixel to discharge the memory capacitor, pre-charging the memory capacitor in the pixel by applying the first voltage to a source of a pre-charge transistor while applying the first voltage to the back plate of the memory capacitor, and applying a second voltage to the back plate of the memory capacitor and the source of the pre-charge transistor, wherein the second voltage is at a higher potential than the first voltage to generate a negative gate-to-source voltage in the pre-charge transistor.