Brother International HL-1070 Service Manual - Page 34

2.2 Paper Transfer 2.2.1 Paper Supply The pick-up roller picks up one sheet of paper from the paper feeder every time it is rotated and feeds it to the paper feed roller. Papers Pick-up roller Registration sensor lever Hopper plate Separation pad Fig. 2.21 The paper is gripped between the pick-up roller and the separation pad and separated into individual sheets. The pick-up roller is directly connected to the sector gear, whose rotation is forcibly stopped by the gear stopper; when the pick-up solenoid is activated, the clutch mechanism is engaged by the solenoid action and the sector gear is driven; when it has completed one full turn its rotation is stopped again by the gear stopper. The paper drawn out by the pick-up roller pushes against the top of form sensor lever and the paper top position/absence of paper is detected by sensing the motion of the lever. 2.2.2 Paper Registration When paper picked up from the multi-purpose sheet feeder (MPF) pushes against the top of form sensor actuator, the registration sensor lever is caused to turn, and the photo sensor detects this motion. When this signal from the sensor is detected the paper feed roller is stopped temporarily by the clutch. The paper is fed to the nip point between the paper feed roller and the pinch roller in the multi-purpose sheet feeder, and the skew of the paper is corrected by pushing the leading edge of the paper against the nip point. When the paper feed roller starts to be rotated again when it is released by the clutch, paper with the leading edge correctly aligned, is fed by the paper feed roller and is transported to the transfer roller. Paper Pinch roller Transfer roller Paper feed roller Drum Clutch mechanism (engaged/released by the solenoid assembly) Released when the solenoid is ON and engaged when the solenoid is OFF. Fig. 2.22 II-18