Xerox Phaser 3425, Service Manual

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2-10 Phaser 34 25 Laser Printer Service Manual
Print Cartridge
The Print Cartridge receives image data in the form of pulsed laser light from the
Laser Scan Unit and creates the image via the xerographic process. The Print
Cartridge contains the following components:
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Charge Roller
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Drum
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Developer Roller (D/R)
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Supply Roller (S/R)
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Metering Blade
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Cleaning Blade
Laser Scan Unit (LSU)
The Laser Scan Unit receives the bit mapped image data from the Main Board and
uses that information to turn the laser beam on and off as required to correctly expose
the drum. Image data transfer from the Main Board is controlled by a synchronization
signal from the LSU so the vertical scanning line is synchronized with the printed
page. The LSU contains the following components:
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Laser Diode: generates the laser beam.
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Rotating Polygon Mirror: scans the laser beam across the drum, axially.
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Beam Detector: synchronizes the left margin.
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Optical Lens System: focuses the laser beam onto the surface of the drum.
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Mirrors: reflect the laser beam onto the surface of the drum.