Patent ID: 7034790
Filing Date: 2006-04-25
Classification: G02F,G09G

Abstract:
1. A liquid crystal display including a liquid crystal layer to which a voltage needs to be applied for preventing backward transition from an alignment state for display, to which an alignment state for non-display has transitioned, to the alignment state for non-display, and a plurality of pixels, in which video signals are written onto the plurality of pixels frame by frame, voltages corresponding to the video signals are held in the respective pixels, and a modulation degree of the liquid crystal layer in the alignment state for display is controlled in accordance with the held voltages, thereby displaying an image, the liquid crystal display being characterized by comprising: a backward-transition-prevention voltage superposing means for temporarily superposing a backward-transition-prevention voltage for preventing backward transition of the liquid crystal layer on the voltages corresponding to the video signals in a hold period during which the voltages corresponding to the video signals are held, and including a display portion with a pair of opposed substrates between which the liquid crystal layer is interposed, one of the substrates being provided with pixel electrodes corresponding to the plurality of pixels on an inner surface thereof and the other of the substrates being provided with counter electrodes on an inner surface thereof, wherein the voltages corresponding to the video signals are held by at least one of liquid crystal capacitors each formed between the pixel electrode and the counter electrode between which the liquid crystal layer is interposed, and the backward-transition-prevention voltage and a punch-through voltage are respectively superimposed on the voltages corresponding to the video signals, and the backward-transition-prevention voltage superposing means is adapted to superpose the backward-transition-prevention voltage on the voltages corresponding to the video signals through control capacitors formed by utilizing the pixel electrodes or conductors connected to the pixel electrodes, independently of the liquid crystal capacitors so as to increase absolute values of voltages between the pixel electrodes and the counter electrodes in respective frames.