Compact cursor pointing device utilizing photodetector array

A compact pointing device generally includes a ball, a light source, and a sensor. The ball includes an outer layer, a reflective inner core and a transparent layer disposed between the outer layer and the inner core. Disposed in the outer layer is a pattern of areas which appear transparent and opaque when illuminated by light generated by the light source. During operation, the light generated by the light source travels through a portion of the outer layer and the transparent layer before illuminating a portion of the inner core. The light is reflected back from the inner core along a path which extends through a portion of the transparent layer and a portion of the outer layer. As the light passes through the outer layer, a "shadow" of the pattern is cast onto the sensor. The sensor responds to movements of the shadow of the pattern (e.g., when a user manipulates the ball) by generating an output which is processed to provide a cursor control output.