| 摘要 |
PROBLEM TO BE SOLVED: To correct color deviation caused by temperature change inside an apparatus without detecting color deviation or by reducing the number of times of detection and also without requiring the measurement of temperature inside the apparatus. SOLUTION: The motor rotation control value of a driving roller given so as to control the speed of a transfer material carrying belt to be constant based on the speed thereof detected by a speed detection means shows the monitoring condition of the temperature inside the apparatus, and the color deviation in width in a main scanning direction and the color deviation in writing start in a subscanning direction caused by the temperature change correlate with the amount of the color deviation caused by the change of the rotation control value and the change of a scanner part (figure 4). Information on the correlated motor rotation control value and the amount of the color deviation is expressed as a table in advance. When the motor control value changes because of the temperature change caused by environmental change or consecutive printing, the amount of the color deviation caused in the scanner part is estimated from the table, and the color deviation correction such as controlling the emission of a laser beam in the scanner is performed according to the amount of the color deviation by a color deviation correction device. |
