Patent ID: 7343110

Claim:
A color image forming device comprising: a plurality of image forming units that form a color image on a recording material; an image position detector that detects a position of each patch pattern of a toner image formed on the recording material and outputs a position detection signal corresponding to the detected position; a temperature detector that detects a temperature inside said color image forming device and outputs a temperature detection signal corresponding to the detected temperature; and a registration error correction control part that performs a first correcting operation and a second correcting operation, the first correcting operation for correcting a registration error of image in accordance with the position detection signal of said image position detector, the second correcting operation for correcting a registration error predicted by referring to a correction table previously prepared in accordance with the temperature detection signal of said temperature detector, wherein said correction table includes a correction value previously determined in response to the temperature inside said color image fonning device and an offset value, which is changed each time said first correcting operation is performed; and said second correcting operation corrects the registration error by a value corresponding to said correction value plus or minus said offset value, and wherein said temperature detector includes a plurality of detectors that detects temperatures inside said color image forming device so as to detect a temperature difference between a temperature of an image forming unit of a reference color and a temperature of an image forming unit of a color other than the reference color.