Patent ID: 6404448
Filing Date: 2002-06-11
Classification: G06K,H04N

Abstract:
A color-image forming apparatus comprising:a plurality of photosensitive members; a light source for emitting a plurality of optical beams; a scanning apparatus for forming images of each color component on the photosensitive members by scanning the plurality of optical beams on the corresponding photosensitive members; a setter capable of arbitrarily and variably setting write start positions in sub-scanning directions of respective colors; a plurality of sub-scanning position detection sensors, each for detecting a sub-scanning position of a scan optical beam of each color; and a calculating unit for calculating a write start position in the sub-scanning direction by adding or subtracting a set value of the setter and a detection result of each of the plurality of sub-scanning position detection sensors, wherein the color-image forming apparatus sequentially transfers the plurality of images formed on the plurality of photosensitive members onto a transfer unit such that the images are superimposed on the transfer unit, to thereby obtain a single image on the transfer unit.