| 摘要 |
<P>PROBLEM TO BE SOLVED: To remove density unevenness periodically caused by a rotation period of an image carrier and vibration of high-order components in the rotation period. <P>SOLUTION: When density unevenness correction is required, a patch for detection is prepared to detect density unevenness. Detected density unevenness data is extracted in a rotation period of a photoreceptor. Density unevenness components which are not caused by the rotation period of the photoreceptor are removed from the extracted density unevenness of the rotation period of the photoreceptor to extract density unevenness components caused by the rotation period of the photoreceptor. Density unevenness data corresponding to one round of the photoreceptor stored in a memory is converted into a parameter for controlling output voltage of a developing high voltage power supply to control a developing bias applied to a developing roller according to the density unevenness, and the parameter is stored as a control table. The developing bias is controlled (corrected) in the rotation period of the photoreceptor according to the density unevenness on the basis of the prepared control table to form an output image with the density unevenness caused by the rotation period of the photoreceptor removed therefrom. <P>COPYRIGHT: (C)2013,JPO&INPIT |
