An electronic equipment with a rolling ball for user input

摘要

A portable radio telephone comprising a housing, a transceiver located in the housing, a controller connected to the transceiver, a display connected to the controller, and a user input device connected to the controller. The user input device comprises a trackball movably connected to the housing and at least one trackball rotational position sensor connected to the controller for sensing rotational movement of the trackball. The sensor includes a roller which rides against an exterior surface of the trackball. The user input device is configured to provide biased stepwise movements of the roller as the trackball is rotated by a user.