Fuji Xerox DocuPrint 2050, Service Manual

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Chapter 10 Machine Overview
10.1 Print Process
10-4
[Exposure]
This step scans the drum surface charged with minus power by laser beams, and forms a latent
electrostatic image on the drum surface.
- Laser beams are radiated according to print data sent from the printer controller. When print data
instructs the system to print black pixel dots, laser beams are output; otherwise, they are not
output.
The laser beams output from the laser diode in the ROS ASSY are scanned between both ends
along the shaft of the drum surface, passing through the rotary polygon mirror, fixed mirror, and
lens attached to the Scanner Assy in the ROS ASSY.
The laser beams radiated on the drum surface creates a pair of electron and hole in the optical
electric-conductor layer. [The hole is generated in the valence band by exciting the electric
conductor with electron.] Electron is drawn to the electrical field, which moves to the metallic part
in the inside. The hole moves to the external surface of the optical electric-conductor, and rejoins
with the minus charge (electron) on the external surface to reduce the minus charge. As a result,
parts at lower minus level (potential rising) are generated on the drum surface to form an invisible
latent electrostatic image (print image).