Xerox Phaser 3117 Service Manual page 18

System Overview
3.1.5 LSU (Laser Scanner Unit)
The LSU unit is controlled by video controller. It scans the video data received from video controller with laser beam
by using the rotation principle of the polygon mirror to create the latent image on the OPC drum. It is the core part of
LBP.
The OPC drum rotates as the same speed as the paper feeding speed. It creates the /HSYNC signal and sends it
to the engine when the laser beam of the LSU reaches the end of the polygon mirror, and the engine detects the
/HSYNC signal to arrange the vertical line of the image on the paper. After detecting the /HSYNC signal, the image
data is sent to the LSU to arrange the its margin on the paper. The one side of the polygon mirror is one line for
scanning..
OPC Drum
Photo Diode
Polygon Mirror
Polygon Motor
Motor Driver
LD Driver circit
LD(Laser Diode)
Protector panel
Service Manual
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