IMAGE READER AND IMAGE READING METHOD

摘要

PROBLEM TO BE SOLVED: To provide an image reader which shortens time for determining shift amount. SOLUTION: The image reader is constituted of a two-dimensional image sensor 7, a micro displacement mechanism 13 which minutely shifts the image sensor 7 from an initial position on a plane to perpendicularly intersect with an optical axis and a detector 21 which detects relative distance between images before and after pixel shifting. The micro displacement mechanism 13 displaces the image sensor 7 until the relative distance coincides with a specified value within an allowable range. The specified value is digitized and its relative distance can completely coincide with the specified value. The relative distance can be approximated to zero at once from the next time by initially displacing the image sensor 7 relative to an original with a value smaller than a set shift amount and detecting actual relative distance at the time. COPYRIGHT: (C)2005,JPO&NCIPI