Patent ID: 8170455

Claim:
A misregistration correcting device comprising: a plurality of image forming units for different colors that form a plurality of sets of misregistration correcting patterns that includes linear patterns each corresponding to one of the colors arranged in a sub-scanning direction, the sets of misregistration correcting patterns including a first set, a second set, and a third set; a pattern detecting unit that starts detecting the first set when a predetermined time has elapsed after start of image formation for the first set; a reading unit that reads positional information of each set of misregistration correcting patterns in response to completion of detection of each set, respectively; and a first determining unit that determines timing to start detecting the first set and the second set of misregistration correcting patterns based on a timer, and the first determining unit determines timing to start detecting each set of misregistration correcting patterns, from the third set, based on positional information of a reference pattern in a set second previous to a set being detected.