| 摘要 |
PURPOSE:To reduce the shaking speed of a belt in the width direction by obtaining a speed correcting value from the siding speed of said belt in the width direction, determining the quantity of deviation, and gradually reducing the moving speed of said belt in its width direction. CONSTITUTION:When a belt 1 is driven and as a photosensor S1 is turned on due to the first zigzag movement of the belt, a signal is inputted in a control part, causing a zigzag-movement correcting roller to be deviated in a correcting direction by a defined quantity. Thereby, if the belt 1 is deviated in the opposite direction, causing a sensor S2 to be turned on, this time, the zagzag-movement correcting roller is deviated in the opposite direction by twice the defined amount. The trend of deviation of the belt 1 is obtained from the difference in the siding speed between the first and second deviations, and the quantity and position of deviation in the initial stage are set so as to offset the trend. After that, the belt is controlled in such a way that the quantity of deviation is gradually reduced and that the siding speed to right and left is equalized. Due to this construction, the shaking speed of the belt in the width direction can be reduced. |
