| 摘要 |
PROBLEM TO BE SOLVED: To obtain an image forming device whose converging property to target rotational speed after the start of rotation or the changeover of rotational speed is made excellent while securing the constant speed of a rotary body which is a constituting member at the time of normal rotation. SOLUTION: This is the image forming device at which a photoreceptive drum 3 that is the rotary body is driven by transmitting the motive power of a photoreceptor motor M4 through a speed reducer 40 whose reduction ratio is Ra. In this case, it is provided with a controlling means by which the feed- back control of the rotational speed of the photoreceptor motor M4 is executed by using an FG(frequency generator) (incorporated in the photoreceptor motor M4) detecting the speed of revolution of the output shaft 42 of the photoreceptor motor M4 until it is converged to the target rotational speed after the driving start of the photoreceptor motor M4 or after the changeover of the rotational speed, and using a rotary encoder 44 detecting the speed of revolution of the rotary shaft 3s of the photoreceptive drum 3 after it is converged. Then, the resolution Ee (pulse/rotation) of the rotary encoder 44 is set to be nearly the same as Ra times of the resolution Eg (pulse/rotation) of the FG. |
