Patent ID: 6795047
Filing Date: 2004-09-21
Classification: G09G

Abstract:
An active matrix type display device comprising:a display panel including column electrodes and row electrodes arranges in a matrix form, a common electrode disposed opposite to the column electrodes and the row electrodes, and pixel units disposed at intersection points between the column electrodes and the row electrodes, a pixel unit being connected to a column electrode, a row electrode and the common electrode; a common electrode driver circuit for outputting a common voltage to the common electrode, the common voltage being in common to the pixel units; a column electrode driver circuit for selecting a column voltage corresponding to display data applied externally, from among a plurality of column voltages corresponding to a plurality of gray-scales, and outputting the column voltage selected to the column electrodes; a row electrode voltage driver circuit for outputting a row voltage to the row electrodes, the row voltage causing the pixel units to be in an â€œONâ€  state; a power supply circuit for generating the common voltage, the plurality of column voltages and the row voltage, and for outputting the common voltage, the plurality of column voltages and the row voltage to the common electrode driver circuit, the column electrode driver circuit and the row electrode driver circuit, respectively; a first switching circuit disposed on the column electrodes between the pixel units and the column electrode driver circuit; and a second switching circuit disposed on the common electrode between the pixel units and the common electrode driver circuit, wherein: the first switching circuit switches into either connection between the column electrodes on a side of the pixel units and the common electrode, or connection between the column electrodes on the side of the pixel units and the column electrode driver circuit, when the second switching circuit is turned â€œOFFâ€ , the first switching circuit makes connection between the column electrodes on the side of the pixel units and the common electrode without making connection between the column electrodes on the side of the pixel units and the column electrode driver circuit, and when the second switching circuit is turned â€œONâ€ , the first switching circuit makes connection between the column electrodes on the side of the pixel units and the column electrode driver circuit without making connection between the column electrodes on the side of the pixel units and the common electrode.