Panasonic UF-890 Service Manual page 216

ADF Mechanism
The ADF (Automatic Document Feeder) automatically feeds paper into the unit, and consists of the
Pre-Feed Roller, ADF Roller and Separation Rubber. Each document is placed face-down on the Paper
Guide Cover before being fed into the unit.
•The Pre-Feed Roller (325) moves the bottom document to the ADF Roller.
•The ADF Roller (323) feeds individual pages into the scanning area.
•The Separation Rubber (229) separates documents placed on the Paper Guide Cover, preventing
multiple feeding.
LED Array Assembly
The UF-890 has one LED Array & one mirror plate, UF-990/895 has two LED Arrays, UF-885 has one
LED Array used as a light source to illuminate the document. The LED Array(s) turn ON when the Read
Point Sensor is activated by the document leading edge.
Transmit Guide Unit
The Transmit Guide Unit is an auxiliary part used for feeding and ejecting documents. It consists of the
Control Panel Chassis (216), Transmitter Chassis (301), Feed Roller (328), Eject Roller (330), and Pinch
Roller (218). This unit also provides the white scanning area and serves as a base for electronic white
reference.
Transmit Mechanism Drive System
This system feeds documents through the transmitting mechanism, and consists of rollers, gears and a
stepper motor.
•The Transmit Motor (346), a stepper motor, controlled by the CPU, drives the Pre-Feed Roller, ADF
Roller, Feed Roller and Eject Roller, with the speed based on the density of the picture information.
•The Feed Roller (328) feeds the document to the scanning point.
•The Eject Roller (330) feeds and ejects the document out of the machine.
Transmit Mechanism Sensors [SNS PCB (121)]
The SNS Assembly (121) performs two functions. The ADF Sensor (PC3), activated by Actuator A
(120), detects the presence of documents on the ADF Tray and multiple pages. The WID (A4/B4 size
document width) Sensor (PC1), activated by Actuator D (134), detects documents that are wider than 9.1
inches (232 mm). The size of the reproduced copy is reduced when the receiver is capable of printing
only letter and A4 size. The size remains the same when the receiver is capable of printing B4 size cop-
ies. Width reduction is also in effect in the copy mode.
The RP (Read Point) Sensor (PC2), activated by Actuator B (119), detects the lead and trail edges of
the document, controlling the reading position. The CPU determines that a document is jammed if
Actuator B is not tripped within a specified time after the ADF Roller starts feeding, and disengages the
Pre-Feed and ADF Rollers by reversing the Transmit Motor direction.
The ADF Door Sensor (PC1), activated by Actuator C (118), halts all scanning operations when the
Control Panel Unit is open.
Verification Stamp Unit
The Verification Stamp Unit stamps an "X" mark on the front of the document after the document is
successfully transmitted or stored. It consists of the Stamp Holder (334) and Stamp Solenoid (335).
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