| 摘要 |
<p>An ergonomic positioning device has a horizontal base (112; 130), a rollerbar (54; 210) having a curved or rounded surface and being depressibly mounted to allow motion with respect to said horizontal base, and a single optical sensor (106; 218; 128) mounted facing the curved or rounded surface to detect translation and rotation of the rollerbar by comparing images of the curved or rounded surface at known time intervals. The optical sensor (106; 218; 128) is mounted to focus on the rollerbar and has a focal range which includes the rollerbar also when depressed, wherein the response of the optical sensor is substantially invariant to the rollerbar motion.</p> |
