| 摘要 |
PROBLEM TO BE SOLVED: To obtain, even in the case a plurality of color images are arranged and formed in the direction of the periphery of a transfer body, a color image of good quality having no color slippage and image disturbance by controlling, based on a scanning-start-signal count, the timing of the start of writing an image in each color corresponding to each color image. SOLUTION: A phase difference between a reference signal BH outputted from a home sensor 22 and an SOS signal outputted from an SOS sensor 11 is detected by a control part 100 through timer measurement. Based on a finite difference between a first-color phase difference and a second-color or later-color phase difference, the speed of the rotation of an intermediate transfer belt 16 is increased/decreased with timing used before an image in each color corresponding to a first color-image in the second color or later color is written. Then, an image-writing-timing control part 101 counts the SOS signals continuously from the timing of the output of the SOS signal. At a point in time that the value of the count reaches a given value, writing-start signals PS corresponding to the first and second color-images are caused to rise. |
