Canon LBP253 SM, Руководство пользователя

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Laser Exposure System
Outline
The laser exposure system forms a latent image on the photosensitive drum according to the VIDEO signalssent from the Main
Controller.
The main components of the laser scanner are the laser unit and the scanner motor unit, which arecontrolled by the signals sent
from the DC controller.
Diagram of the Laser Scanner Unit is shown below.
Main controller
DC controller
Engine controller
Scanner mirror
Scanner motor unit
Photosensitive drum
BD sensor
Laser unit
L
ASER
C
O
N
T
R
O
L
si
g
n
a
l
VI
D
EO
si
g
n
a
l
SC
AN
N
ER
MO
T
O
R
SPEED
C
O
N
T
R
O
L
si
g
n
a
l
BD
I
N
PU
T
si
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l
Optical Unit Failure Detection
The optical unit failure detection manages the laser scanner failure detection functions.
The DC controller determines an optical unit failure and notifies E100 to the Main controller if the laser scanner encounters the
following conditions:
• If the scanner motor does not reach a specified rotation within a specified period of start-up.
• If the rotation of the scanner motor is out of specified range for a specified period during drive.
• If an out of specified BD interval is detected during a print operation.
2. Technology
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