| 摘要 |
<P>PROBLEM TO BE SOLVED: To solve a problem that it is difficult to predict that image quality is deteriorated if printing is performed further before the image quality is deteriorated though it is necessary to perform calibration for correcting the irregularity of toner density in a color image forming apparatus. <P>SOLUTION: A method where the number of printed sheets is set as reference is considered as reference to take appropriate timing to perform the calibration. In this method, however, the amount of heat stress on toner material and a photoreceptor caused by the difference of printing density in every printing can not be exactly acquired. Then, the number of cumulative printed dots is adopted as the index of the time to perform the calibration, and a means for counting the number of cumulative printed dots is provided in the image forming apparatus. When the number of the cumulative printed dots counted by the dot counting means exceeds a designated threshold, the calibration is performed. <P>COPYRIGHT: (C)2007,JPO&INPIT |
