Exposure System; Laser And Scanner Unit; Laser Beam-Blocking Shutter - Canon LBP-CX Series Service Manual

tV. EXPOSURE SYSTEM
A. laser and Scanner Unit
1. Outline
The laser and scanner unit comprises the laser unit
and the scanner unit.
The scanner unit comprises the scanner motor,
scanner driver PCB, scanner mirror and focusing
lenses.
2. Removing the laser unit and scanner unit
(1)
Open the printer (raise the upper half). Open the
right door and take out the EP cartridge.
(2) Close the right door, then the upper half of the
printer.
(3) Remove the rear panel and top cover.
(4) Unplug connectors J203, J204 and J206.
Connect the laser shorting connector to J204
(cables attached).
(5) Remove the screws (4), and carefully lift the
laser/scanner unit from the positioning pins.
Figure 4-60
(6) Take off the rubber cap of the laser and scanner
unit. Remove the two Allen screws and take out
the laser unit.
Reference:
If the scanner motor or the scanner driver PCB is
broken, but the laser unit works, remove the old
laser unit and install it along with a new scanner unit.
Laser /and sea.oner unitl
.
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Figure 4-61
3. Installation
(1)
Align the laser unit to the locating pinhole. Put
the two Allen screws in loosely, then tighten
them alternately so that the laser and scanner
unit fits firmly.
(2) Align the laser and scanner unit with the locat-
ing pinhole.
(3) Installation is the reverse of removal.
Note:
When installing and removing the laser and scanner
unit, be careful not to scratch the scanner driver
PCB.
Be careful not to leave fingerprints or dust on the
window, mirrors, lenses, or laser unit mounting
plate.
Oean the mounting face of the laser and scanner
unit before installing the unit.
Do not bend the optic fiber cable a radius of
15 mm or less to prevent damaging to the cable.
To prevent damage to the laser from static elec-
tricity, connect the laser shorting connector
(RY9-0003) to the laser unit. Do not unplug
the laser shorting connector until the laser con-
nector is plugged into the DC connector.
4. Laser beam-blocking shutter
Removal
( l) Take out the laser and scanner unit. (See Fig.
4-60.)
(2) Remove the ozone seal plate, the two tension
springs, the fastening screw and the two guide
bushings. Take out the shutter.
4-16
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©
BY CANON INC. CANON LBP·CX SERIES REV.2 JULY 1985 PRINTED IN JAPAN (IMPRIME AU JAPON)