Development Process; Paper Feed; Exposure Unit - Xerox Phaser 3450 Service Manual

CIRCUIT DESCRIPTION

11.2.2 Development Process

11.2.2.1 Paper Feed

Paper feed unit is operated by the engine and solenoid rotates the feed roller to feed one sheet of paper. The paper then
moves on to the set and hits the actuator of
the feed sensor. The engine at this time detects that signal and prepare to spread the the image data. If problems occurs
in the feed sensor, Paper Jam Error will appear in the OP panel. The feed sensor section is also closely related to the top
margin of the paper.
11.2.2.2 Electric Charge
This section charges uniform (-)voltage to OPC. When (-1380V) is charged to the Charge Roller, OPC drum is evenly
charged with approximately -800V. This is the first stage of the electric photo creation.
C/R
-800V
-1380V
OPC

11.2.2.3 Exposure Unit

LSU exposes OPC drum by turning Laser Diode On/Off according to the digital data of the bitmap image data received
from the controller board. The voltage difference created at this point is shown above. The exposed area to the laser is -
150V, which relatively increases the electric potential and forms charge ripple. The areas that are not exposed to the laser
due to no video data will maintain -800V. As a result, image(black dot) is created in the -150V area and the -800V area
will show up white, which creates the basic condition of image formation.
Unexposured
Unexposured
Exposured
-800V
-800V
-150V
OPC Surface
Service Manual
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