Patent US 4,521,772

A cursor control device or "optical mouse" for use with an interactive display oriented computer system to provide movement for a visible cursor from position to position on a display screen of such a system. The device includes an IC chip that contains an optical sensor array and circuitry to bring about detectable bitmaps based upon a plurality of sensor cells making up the array. The distinguishable bitmaps are employed as a means for comparison to provide an output indicative of the direction and amount of movement of the cursor control device relative to an optical contrasting input to the array, the output is employed as a means to move the visible cursor from position to position on a display screen.