Ricoh SP 8400DN Field Service Manual page 1413

Paper feed transport mechanism
In order to maintain a proper interval of each paper, this machine has a paper feed sensor near the paper feed roller
to adjust the timing of paper feeding.
1. The Paper feed motor is switched ON, and the first sheet is supplied.
2.
The paper feed motor switches OFF right before the rear edge of the first sheet completely passes the paper
feed roller.
3. The pick-up arm lowers the pick-up roller, which makes the pick-up roller contacting with the surface of the
paper when the rear edge of the first sheet finishes passing the paper feed roller.
4. The paper feed motor switches ON to supply the second sheet of paper when the first sheet is transported for
a predetermined distance by the downstream transport roller.
Paper size detection (1st / 2nd paper tray)
The end fence interlocking rotation detection plate is an automatic detection system which recognizes patterns by
a 4-position push switch.
Size is detected by the detection patterns of knobs 1, 2, 3, and 4. Tray set is detected by the tray set switch.
If there has been a change in the pattern, "machine tray automatic size detection" control is performed
continuously.
If the paper size is selected manually by user setting, the automatic size detection is overridden.
7.Detailed Descriptions
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