Canon LBP 2460 - B/W Laser Printer, Руководство по обслуживанию

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III. LASER/SCANNER SYSTEM
A. Outline
Figure 2-3-1
When the DC controller receives a print signal (/PRNT) from the video controller, the DC
controller automatically stabilizes the intensity of the laser beam (automatic laser power control:
See page 2-27). The DC controller then receives the VIDEO signal (VDO) from the video
controller and sends it to the laser driver in the laser/scanner unit.
The laser driver turns the laser diode on and off according to the VDO signal and generates
the modulated laser beam only when the VIDEO DATA ENABLE signal (/LENBL) from the DC
controller is “L”.
The modulated laser beam is aligned by a collimator lens and a cylindrical lens into a parallel
beam that strikes the scanning mirror that is rotating at a constant speed.
The beam reflected from the mirror is brought to a point of focus on the photosensitive drum
by the focusing lens located after the scanning mirror.
As the scanning mirror rotates at a constant speed, the beam is scanned across the drum at a
constant speed.
The drum also rotates at a constant speed allowing the laser beam to form an image on the
drum's surface.
CHAPTER 2
2 - 26
/BD VDO /VSYNC
/BDI VDO /LON LLCONT /SCND
Cylindrical lens
Focusing lens
Scanning mirror
Scanner motor
Mirror
/LENBL PD /SCNRDY
External device
Video controller PCB
DC controller
BD PCB
BD mirror
Laser driver
Photosensitive drum