Canon LBP5000 Series, Руководство по обслуживанию

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Chapter 2
2-3
F-2-3
The machine's laser/scanner unit is designed in such a way that a single scanner mirror is used to guide 2 laser beams (colors) at the same time (4-laser/2-mirror
method). Instead of the 4 scanner mirrors and scanner motors, the machine uses 2 mirrors and motors to perform the same mechanism, permitting the use of a smaller
laser unit and, ultimately, a smaller machine size.
The machine uses 4 laser diodes, 2 each on the 2 laser driver PCBs. It uses 2 scanner motors with a single scanner mirror reflecting 2 laser beams (colors).
F-2-4
The machine operates in the following sequence to execute a print job:
1) In response to the print command for the video controller PCB, the DC controller PCB rotates the scanner motor to turn the scanner mirror.
2) When the scanner motor starts to rotate, the DC controller PCB turns on the laser, and obtains /BD input signal from the BD sensor. The DC controller PCB finds
out the speed of rotation of the scanner motor with reference to the timing of the /BD input signal to make sure that the motor rotates at a specific speed of rotation.
3) When the speed of the scanner motor has stabilized, the laser driver PCB turns on the laser diodes according to the video signal.
Bk
Y
C
M
VDO4, /VDO4
VDO3, /VDO3
VDO2, /VDO2
VDO1, /VDO1
Laser driver PCB
BD sensor
Laser diode
(cyan)
Scanner mirror
Laser beam
Photosensitive drum
Laser diode
(magenta)