| 摘要 |
An apparatus, such as a mouse, for controlling a screen cursor for an electronic device (10) having a display screen includes a light source (2) for illuminating an imaging surface (6), thereby generating reflected images. An optical motion sensor generates digital images from the reflected images at a first rate. The motion sensor (16) is configured to generate movement data based on digital images. The movement data is indicative of relative motion between the imaging surface and the apparatus. The motion sensor is configured to modify the first frame rate to one of a plurality of alternative frame rates based on a current relative velocity between the imaging surface and the apparatus. In an alternative embodiment the apparatus is configured to enter a low power mode after a period of inactivity, wherein the generated digital images have few pixels than in the full power mode. In yet another embodiment, the motion sensor generates a plurality of pairs of digital images with an intra-pair time delay and an inter-pair time delay, the inter-pair time delay being greater than the intra-pair time delay. The apparatus may alternatively be an optical trackball or an optical fingerprint sensing device. |
