| 摘要 |
PROBLEM TO BE SOLVED: To form a color image free from color shear between images of different colors by aligning the image draw start position of each color image accurately. SOLUTION: A beam of light based upon the fed image information is deflected, and therewith a polygon mirror 103 scans a photoreceptor drum 105 which is rotated by a photoreceptor drum motor 115, and the scanning beam from the polygon mirror 103 is sensed by a BD sensor 107 to generate a scan start reference signal (BD signal) for each line having the same period, the BD signal, which is divided by a frequency dividing circuit 119 by the specified frequency dividing proportion so that the drum 105 makes one turn accurately while a certain integer number of BD signals is generated, generates a reference CLK which are driving pulses for the drum motor 115, and a PLL circuit 118 makes drive control of the motor 115 on the basis of the reference CLK for the motor 115. |
