General Information
Phaser 3320 and WorkCentre 3315/3325
Xerox Internal Use Only
Service Manual
1-26
Laser Scanning Unit (LSU)
It is the core part of the LBP which switches from the video data received to the controller to the
electrostatic latent image on the OPC drum by controlling laser beam, exposing the OPC drum, and
turning principle of the polygon mirror. The OPC drum is turned with the paper feeding speed. The
/HSYNC signal is created when the laser beam from LSU reaches the end of the polygon mirror, and the
signal is sent to the controller.
The controller detects the /HSYNC signal to adjust the vertical line of the image on paper. In other
words, after the /HSYNC signal is detected, the image data is sent to the LSU to adjust the left margin
on paper. The one side of the polygon mirror is one line for scanning.
s3320-264
Photo Diode
Laser Diode
Driver Circuit
Protector Panel
Laser Diode
Motor Driver
Polygon Mirror
OPC Drum
Polygon Motor