System for directly sensing the orientation of a track ball

Abstract

A track ball device includes a ball having a pattern of first conductive features and a socket into which the ball rotatably sits, the socket having a pattern of second conductive features. Also disclosed is a sensing array system for determining relative motion including a first substrate having a plurality of interstitially arranged electrodes provided thereon. A second substrate has a plurality of transfer electrodes provided thereon. The first and second substrates are movable relative to each other, and the plurality of interstitially arranged electrodes selectively operate as driving electrodes for providing a plurality of signals to the sensing array and as collecting electrodes for collecting signals capacitively transferred from the driving electrodes by the transfer electrodes. The sensing array is useful in a battery operated track ball device, a mouse or other device that must be able to determine relative motion over two degrees of freedom.Published versio