Xerox WorkCentre 385, Service Manual

Page: 180 / 184

WorkCentre 385
Engine Controller
12/98
7 - 46
Paper S5V)
There are three Sensors for the paper in the
Printer:
1. Paper Empty Sensing
It is placed in Paper Cassette, and senses if
there are papers in Cassette.
2. Paper Feed Sensing
It is placed before Transfer process, and
senses if the paper is feeding. When the
paper feeding is sensed by it, Printer image
data is output to LSU.
3. Paper Check
It is placed on the side of paper path. When
narrow paper is feeding, the paper does not
touch the actuator, and it is sensed the narrow
paper. The Printer Engine check resistance of
Transfer Roller and the feeding paper, if the
feeding paper width is narrow, THV according
to the resistance outputs higher voltage than
wide paper.
4. Exit Sensing
It is placed in the exit of Printer, and senses
the paper exit.
LSU Control
LSU is composed of a polygon mirror motor and a
laser gun part. The polygon mirror motor starts
rotation by “PMOTOR” signal and reaches the
constant speed, “LREADY” signal outputs “High”
from LSU. And when video image signal from
Video Controller is applied to Laser Gun, it fire the
laser beam. And the polygon mirror reflects and
scans the beam horizontally. When the scanned
laser beam reaches at the side of LSU, “HSYNC”
outputs one pulse. Video controller synchronizes
this signal, and outputs the left edge of image.
New Developer Check
A fuse is placed in Developer unit, When user
opens Printer front cover, Engine Controller
checks the fuse open. If the fuse is not opened,
Engine Controller judges the Developer unit new,
and clears the “used sheet counter” in NVRAM,
and applies 24V to the fuse in New Developer
Unit.
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