| 摘要 |
<p>A handheld communication device including a trackball-based cursor navigation tool includes a display screen, a plurality of trackball roll-direction detectors, each engaging the trackball and primarily actuated by one of a vertical horizontal, and diagonal rotation of the trackball relative to the display screen. The roll-direction detectors can each have a roller in contact with the trackball and rotatable about a corresponding rotational axis and can each also have a sensor for sensing the rotation of the trackball and outputting a signal representative of the amount of rotation of the trackball. A microprocessor receives the signals output the roll-direction detectors, processes the signals to determine whether primarily vertical, horizontal, or diagonal movement has been detected, and outputs corresponding control signals to a screen cursors control to affect the movement of a cursor on the display screen.</p> |
