| 摘要 |
PURPOSE:To always normally form an image according as the density of picture elements is changed. CONSTITUTION:In a CPU 20, the plural pieces of data as for the rotational speed of a polygon motor 6 corresponding to the density of the respective picture elements stored in a ROM 27 is compared with the data of the actual rotational speed as for the motor 6 by a comparator 23. When both data coincide with each other, optical writing is started by judging that the rotational speed of the motor 6 attains the set rotational speed corresponding to the density of the picture elements. |
