| 摘要 |
An autofocus device is provided that includes a lens drive system, an imager, a contrast detector, first and second peak detectors, and a backlash detector. The lens drive system translates a lens. The imager captures an image through the lens. The contrast detector detects the contrast of an image captured by the imager. The first peak detector detects a first contrast peak of images captured at different lens positions when the lens is translated in a forward direction. The second peak detector detects a second contrast peak of images captured at different lens positions when the lens is translated in a backward direction. The detection of the second peak is carried out after detection of the first contrast peak. The backlash detector detects the backlash in the lens drive system according to the positions of the first and second contrast peaks. |
