| 摘要 |
<P>PROBLEM TO BE SOLVED: To facilitate associating between the position of the sub-scanning direction of a sub-module and density data, when acquiring correction data for suppressing density uneveness in the sub-scanning direction which is caused by the sub-module. <P>SOLUTION: A correction setting part in a density correction part acquires a first phase signal PS1, obtained by reading out a first mark of a photoreceptor drum, a second phase signal PS2, obtained by reading out a second mark of a developing sleeve, and first light quantity correction data corresponding to the periodical uneveness of the photoreceptor drum and a second light quantity correction data, corresponding to the periodical irregularity of the developing sleeve, on the basis of the read result of a correction image prepared on an intermediate transfer belt by using the first and second phase signals PS1, PS2. When the correction image is prepared, a first image G1 of high density is formed in the correction image synchronously with the detection of the first mark and a second image G2 of low density is formed synchronously with the detection of the second mark. <P>COPYRIGHT: (C)2007,JPO&INPIT |
