| 摘要 |
PURPOSE:To reduce the shaking speed of a belt in the width direction by gradually reducing the siding speed of said belt, and controlling said belt through a defined quantity of deviation after the siding speed to right and left is equalized, when determining quantity of deviation from the corrected value of said siding speed of belt to correct zigzag movement. CONSTITUTION:When a photosensor S1 is turned on due to the first zigzag movement of a belt, a control part makes an unshown zigzag-movement correcting roller deviate in a direction to be corrected, by a defined quantity. Then, when deviation to the opposite side causes a photosensor S2 to be turned on, the control part makes the roller deviate in the opposite direction by twice the defined quantity. The trend of deviation is obtained from the difference in siding speed to right and left between both deviations, to determine the quantity and position of deviation in the initial stage. After that, the quantity of deviation is gradually reduced each time each of the photosensors S1, S2 is turned on, while being corrected so that the siding speed to right and left is made equal. After the point of time when the siding speed to right and left is equalized, the quantity of deviation is set to a defined minute quantity and the siding speed is rapidly reduced, correcting the zigzag movement in a short time. Thereby, the shaking speed of the belt in the width direction can be reduced. |
