Patent ID: 6920303
Filing Date: 2005-07-19
Classification: G03G

Abstract:
1. A method for detecting color offset, comprising: forming different color visual images on a photosensitive member; providing a transfer medium driven by a driving roller and configured to receive at a transfer section from the photosensitive member and superpose the different color visual images, said transfer medium transferring the different color visual images to a transfer sheet; forming a plurality of mark sets on the transfer medium, each of said mark sets being formed from a set of different color marks aligned in a movement direction; detecting respective marks with at least one sensor; calculating an average of displacements of respective different color marks from a reference position; and positioning the at least one sensor away from the transfer section by a prescribed length along the transfer medium, said prescribed length being calculated by multiplying (i) a conveyance length the transfer medium travels when the driving roller rotates once and (ii) an integer number.