| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide improvement in robustness of an image reading apparatus and maintenance-free property by detecting correction data abnormality caused by device deterioration or the like, and changing or correcting a correction value or a correction value calculation parameter. <P>SOLUTION: An image reading apparatus includes a CCD image sensor 301 of four channels; a linearity section 305 for performing digitization for each output from output parts of said CCD image sensor 301, symthesizing a first half portion and a second half portion in each of output directions, and correcting linearity for each of the output directions of the first half portion or the second half portion; and a storage device for storing a correction value or a correction value calculation parameter for correcting linearity. Corrected data of the first half portion and the second half portion are compared and collated with each other by an abnormality detection and correction amount calculator 309 and a CPU 311. When a comparison and collation result gets out of a set standard value, such a case is detected as abnormality. <P>COPYRIGHT: (C)2007,JPO&INPIT |
