| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a technique capable of detecting oblique carriage without using an optical sensor.SOLUTION: An image forming system includes a plurality of contact units 29 arrayed in the direction vertical to a sheet paper carriage direction in a specified area of a sheet paper carriage path. When the contact units 29 are brought into contact with a passing sheet paper Q, the contact units 29 operate a reaction force to the sheet paper Q. In the system, the sheet paper Q comes into contact with the contact units 29 and, thereby, the oblique carriage of the sheet paper Q is detected based on a change of the reaction force acting on a motor. The motor rotates and drives a paper feed roller arranged on the upstream of the contact units 29. The paper feed roller carries the sheet paper Q by rotation to the downstream rather than the contact units 29. Accordingly, when the sheet paper Q comes into contact with the contact units 29 during the carriage procedure to the downstream, the reaction force due to the contact is generated on the motor. In particular, when the oblique carriage occurs, the sheet paper Q comes into contact with each of the plurality of contact units 29 with different timing and, therefore, the peak of the reaction force appears at two times. When the twice appearance of the peak, the oblique carriage is detected.</p> |
