Ricoh FW780 Service Manual - Page 424

MECHANICAL OPERATION [B] [A] B436D502.WMF After the leading edge of the paper reaches the exit rollers [A], the paper is directed to the copier registration roller [B]. The registration roller stops rotating once the registration sensor detects the leading edge of the copy paper. The copy paper stops and waits for the original. Shortly after the original registration sensor is activated by the original, the registration roller and roll paper feed motor start to rotate. The copy paper starts to feed again. Just before the cut length of copy paper is fed, the speed of the roll paper feed motor is doubled. A paper buckle forms at the trailing edge of the copy paper. When the paper reaches the proper length, paper feed motor stops and the cutter unit cuts the paper. During the time that paper feed motor has stopped, the registration roller continues to feed the copy paper forward. The paper is cut during the time it takes for the paper buckle to be pulled taut. This allows for a neat cut. When the selected cut length is between 245 mm and 340 mm, the paper reaches the selected length before the registration roller starts to rotate again. In this case, after the registration roller stops, the roll paper feed motor continues to rotate and a paper buckle forms at the trailing edge of the paper. The registration roller brake ensures that the very stiff types of paper will not rotate the registration rollers as the excess paper is fed forwards. The paper is then cut. When the selected cut length is between 340 mm and 410 mm, the roll cutter unit cuts the paper after the second rotation of the roll paper feed roller. [RW1] The paper buckle forms after the first rotation of the roll paper feed motor, because the paper feed roller is still rotating after the registration roller has stopped. The registration roller brake ensures that the very stiff types of paper will not rotate the registration rollers when the paper buckles while it is stopped at these rollers. B435/B436 7-4 SM