| 摘要 |
PROBLEM TO BE SOLVED: To prevent defective images, such as black stripes from being produced in an obtained image by rewriting each coefficient of an MTF correction filter into a prescribed value, when a count of an operating time count means reaches a prescribed value. SOLUTION: A system control section 3 feeds one original to be fed and reads a count of a non-processing operating time from a clock circuit 9. When a timer count exceeds a setting value (e.g. 1000 hours), the control section 3 conducts a processing corresponding to dirt of a read optical system, resets and restarts the timer and conducts the original read processing. The control section 3 changes an MTF correction (correction for emphasizing density difference of adjacent dots) coefficient of each register of an MTF correction coefficient memory as a processing to cope with dirt to change the correction coefficient which have been set initially to be higher into a weaker setting. Or the control section 3 allows a display section 7 to display a message, to the effect that 'maintenance is required'. |
