| 摘要 |
PURPOSE:To detect the rotational speed of a drum without damaging detection precision through the use of an inexpensive encoder by using a roller coming into contact with the outer periphery of a rotary drum and rotated accompanying with the rotation of the rotary drum. CONSTITUTION:The roller 15 whose diameter is smaller than that of the rotary drum 2 is brought into contact with the outer periphery of the rotary drum 2 carrying a sensitized paper and rotated at revolving speed higher than that of the rotary drum 2 accompanying with its rotation. A peripheral speed detecting encoder 13 having comparatively low resolution is connected with the roller 15 and outputs a pulse column corresponding to the rotational speed of the roller 15. The f/V conversion of the signal of the output is executed so that a speed detection signal corresponding to the rotational speed of the rotary drum 3 can be obtained. |
