| 摘要 |
PROBLEM TO BE SOLVED: To provide a multicolor image forming apparatus that can form a high quality image free from color shift or discoloration by a method wherein deviation of a sub-scanning registration between stations is precisely corrected by one line or less and a correction position is stably held even when a condition is changed with lapse of time. SOLUTION: There is disclosed the multicolor image forming apparatus wherein electrostatic images formed by a plurality of optical scanning means are respectively developed by each color toner and the color toner images are superposed on a transfer body 105 to form a color image. The multicolor image forming apparatus comprises a registration deviation detection means 156 for detecting an amount "d" of deviation of registration in the sub-scanning direction between superposed color toner images and a rotational phase detection means for detecting a rotational phase "t" between polygon mirrors 106. The amount "d" of deviation of registration is corrected by controlling to allow the rotational phase "t" to satisfy the formula: t=d/v-k/f in a condition that "k" is an integer number capable of minimizing "t", with the proviso that "v" represents a moving speed of the transfer body 105 and "f" represents a scanning frequency of the polygon mirror 106. COPYRIGHT: (C)2006,JPO&NCIPI |
