Xerox Phaser 3330, Service Manual

Page: 40 / 434

General Information
Xerox Internal Use Only Phaser 3330 and WorkCentre 3335/3345
Service Manual
1-29
Laser Scanning Unit (LSU)
The LSU is the core part of the IOT that converts video data received from the controller into the
electrostatic latent image on the OPC drum, using a modulated laser beam reflected from the rotating
polygon mirror, exposing the main charge on the OPC drum. The OPC drum is rotated at the same rate
as the media feeding speed.
The HSYNC signal is created when the laser beam from the LSU reaches the end of the polygon mirror
face as it rotates, and the signal is sent to the controller, which uses this to synchronize each scan line
the laser makes in the horizontal axis by adjusting the image data sent to the LSU. Each face of the
polygon mirror is used for one scan line on the OPC drum.
s3320-264
Photo Diode
Laser Diode
Driver Circuit
Protector Panel
Laser Diode Motor Driver
Polygon Mirror
OPC Drum
Polygon Motor