Xerox WorkCentre 3210 Service Manual page 91

WorkCentre 3210/3220 Multifunction Printer Service Manual
Laser Unit
The Laser Unit (LSU) receives image data from the PVC or HPVC and make
latent image on the OPC surface. The LSU uses dual beam system, LD1 and
LD2. The control method of the two beams are the same. In comparison with
a single beam system, dual beam contains half of the LSU's frequency.
The LSU consists of laser diode (LD) and the polygon motor control. When
the printing signal occurs, the laser diode is turned On and the polygon motor
is enabled. When the light sensor detects the beam, H-SYNC occurs. When
the polygon motor speed becomes steady, Ready mode occurs. If these two
conditions are satisfied, the Laser Unit is ready. If the two conditions are not
satisfied, one of the two errors are reported as shown in the table below:
Error
Polygon Motor Error
H-SYNC Error
Description
When the polygon motor speed is not steady.
The Polygon Motor speed is steady, but the H-SYNC is
not generated.
Theory of Operation
2-35