Patent ID: 7952554

Claim:
A display driver capable of partial display comprising a memory to store display data, the display driver driving a display panel which includes a plurality of data lines and a plurality of scanning lines matrix-arranged and having a pixel at each crossing point thereof, wherein the display driver controls switching between a normal display mode for displaying an arbitrary image on a whole screen of the display panel and a partial mode for displaying the display data stored in the memory only on an arbitrary display area, wherein the partial mode allows changing the display data of an image to be stored in the memory and the arbitrary display area of the display data stored in the memory according to a command from an external device, and wherein the display driver further comprises a switching circuit which automatically switches displaying from a display pattern which is independent of the image size of the arbitrary display area and displayed while changing the display data of the image to be stored in the memory and the arbitrary display area of the display data stored in the memory to a display including the display data stored in the memory which is displayed after the change has ended.