Image scanner using low-pixel-density CCD to achieve high-pixel-density scanning quality by pixel-level shift of CCD

摘要

An image scanner performing multiple scanning operations for a single scan line is disclosed. The additional scanning operations are performed between two adjacent pixels. For a double scanning mode, the CCD performs one scanning operation for a scan line at a first position. Then, the CCD is moved from the first position to a second position along the X-direction to perform the other scanning operation at the second position. The distance between the first and the second positions is a half of the distance between two adjacent pixels. The scanning data of the two scanning operations are alternatively arranged and converted into final image data. By this way, a low-pixel-density CCD can be used to obtain a high-pixel-density scanning quality.