| 摘要 |
<p>A 3D track ball system comprises a housing defining a bottom wall, and a top wall. The top wall is kept in spaced apart relationship above the bottom wall and an inner space of the housing is defined therebetween. An aperture is provided in the top wall. The system further comprises a track ball of a solid structure or a shell structure and made from a material such as aluminium, steel, plastic, preferably plastic having an optically patterned surface allowing an optical detection of the motion of the surface and optionally having a high friction surface coating. A set of supporting elements is provided for supporting the track ball. The supporting elements are positioned within the housing in positions in a plane parallel with the bottom wall and providing a stable and self-centring support of the track ball in relation to the housing. A motion detection system is further provided including a plurality of optical motion detectors for detecting the motion of the track ball and for generating signals representing the motion of the track ball, each of the plurality of optical motion detectors being positioned juxtaposed the track ball in positions defining an orthogonal motion detection system having its centre positioned at the centre of the track ball, the plurality of optical motion detectors detecting the motion of the track ball in relation to axes of the orthogonal motion detection system.</p> |
