Drum Charge; Laser Exposure; Figure 2-5. Laser Exposure - Epson C11C605001 - DFX 9000 B/W Dot-matrix Printer Service Manual

Service Manual
EPL-9000

2.1.1.1 Drum Charge

Drum charge is the process of charging static electricity to the OPC (Organic Photo Conductor)
drum before laser exposure. The charge wire discharge to the OPC drum surface potential of the
connected to the ground through the zener diode, limits the discharge to the OPC drum to
maintain the OPC drum surface potential at the specified level (-310 VDC).

2.1.1.2 Laser Exposure

Laser exposure is the process of creating an invisible static electricity image on the OPC drum by
laser beams emitted from the ROS (Raster Output Scanner) Assembly. The polygon mirror is
rotated by the polygon motor (scanner motor). This is
clockwise direction to produce a laser light scan (one side of the mirror produces one scan). The
SOS (Start Of Scan) sensor detects the laser rays from the SOS mirror and outputs SOS signals in
order to make the starting position of each line of the image uniform.
Laser emission
PC Drum
Invisible static-
electricity image
Rev. A
Charge Screen
Figure 2-4. Drum Charge

Figure 2-5. Laser Exposure

Operating Principles
1
six-sided mirror which rotates in the
a
/ ' - l
I
Scanner Assembly
2-3