Xerox Phaser 6121MFP Service Manual page 94

Theory of Operation
Tray 1 Media Detection
2-52
The fixed Separation Pad system plus the Retard Rollers are used for paper
separation. This ensures that only one sheet of paper is fed.
Pick-Up Roller
Tray media empty/misfeed conditions are detected by the registration sensor.
Registration Sensor
To reduce the number of detected paper misfeeds, another feed sequence is
carried out if a registration sensor signal transition fails to occur within a
predetermined period of time. If after the second feed attempt media is not
detected, a media empty/misfeed condition is reported.
Separation Pad
Retard Rollers
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Phaser 6121MFP Service Manual