Canon 1730, Service Manual

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Technical Explanation > Laser Exposure System > Various Controls > Controlling the Laser Shutter
Technical Explanation > Laser Exposure System > Various Controls > Controlling the Laser Shutter
■
Controlling the Intensity of Laser Light
● APC Control
The machine monitors the laser light that is emitted to the built-in photo diode of laser diode
and adjusts the laser to appropriate intensity.
■
Controlling the Laser Scanner Motor
● Controlling the Laser Scanner Motor
From when the laser scanner motor starts and the laser scanner motor reaches the number
of target rotation to before image formation starts, the machine controlsthe rotation speed by
referring to the laser scanner motor rotation speed signal (FG signal).
During image formation, it controls the laser scanner motor rotationspeed based on BD
signal.
Laser scanner motor rotation speed is controlled by speed-up signal (ACC signal) and speed-
down signal (DEC signal).
ACC DEC FG
J208
DC Controller PCB
F-2-61
■
Controlling the Laser Shutter
● Laser Shutter Control
When the right door opens, laser shutter will be closed by laser shutter link that works in
conjunction with the right door and the laser light is blocked. Also, whenthe front door or right
door open is detected, laser scanner motor and the laser emission will be turned OFF.
[1]
[2] [2]
[2]
[1] [3] [3] [1]
DOOR CLOSED
DOOR OPEN
[
1] Laser shutter
[2] Laser shutter link (works in conjunction with the right door)
[3] Laser unit
F-2-62