| 摘要 |
PROBLEM TO BE SOLVED: To correct the positional displacement (color smeare) of respective image forming units for a plurality of colors, except black, while maintaining the monochrome printing productivity of a black image forming unit. SOLUTION: A print control section 51 causes a secondary transfer control section 55 to separate a secondary transfer section 15 from an intermediate transfer body, causes a direct transfer control section 54 to control the black image forming unit 12K, thereby forming a black image and transferring it to transfer paper being conveyed, and also causes an alignment control section 52 to perform an alignment control process. This enables the apparatus to parallelly perform a monochrome printing operation of the black image forming unit 12K by the direct transfer control section 54 and alignment control for the image forming units (12Y, 12C, and 12M) other than the black one. Accordingly, while the monochrome printing productivity of the black image forming unit 12K is maintained, displacement (color shift) of each of the image forming units (12Y, 12C, and 12M) can be corrected. COPYRIGHT: (C)2010,JPO&INPIT |
