Patent ID: 7800571

Claim:
A method for driving a dark ring of a microdisplay during a frame period, said microdisplay including a display area having a plurality of pixels for displaying an image, comprising: providing a dark ring surrounding the plurality of pixels of the display area, said dark ring including a dark ring up metal and a dark ring down metal, said dark ring up metal and said dark ring down metal being electrically isolated from each other; controlling said dark ring up metal to show an all-black image during a frame period firstly; controlling the pixels of the display area to show the image during the frame period secondly; and controlling said dark ring down metal to show an all-black image during the frame period lastly; wherein the polarity for each of said dark ring up metal and said dark ring down metal is adjusted in accordance with the polarity of adjoining pixels within the microdisplay and the scan direction of gate drivers to coincide with that for adjoining pixels within the display area; wherein the polarity of the dark ring up metal changes from positive to negative synchronously with a topmost scan line within the microdisplay to coincide with the polarity inversion for the adjoining pixels on the topmost scan line within the display area; wherein the polarity of the dark ring down metal changes from positive to negative synchronously with a bottommost scan line within the microdisplay to coincide with the polarity inversion for the adjoining pixels on the bottommost scan line within the display area; and wherein the polarity of the dark ring down metal does not change from positive to negative synchronously with the change from positive to negative of the polarity of the dark ring up metal.