Laser/Scanner System; O U T L I N - Canon LBP-2000 Service Manual

CHAPTER 2
III. LASER/SCANNER SYSTEM
A. O u t l i n e
No. 1 reflecting mirror
Photosensitive drum
The video signals (/VDO, VDO) from the video controller are sent to the laser driver of the laser/
scanner assembly by way of the DC controller.
If the image formation enable signal (/ENBLO) from the DC controller is 'L', the laser driver turns
on/off the laser diode according to the video signals (/VDO, VDO) to generate a modulated laser
b e a m .
The modulated laser beam is turned into a parallel beam by the work of the collimator lens and the
cylindrical lens, and is directed to the 6-faceted mirror, which is rotating at a specific speed.
The laser beam reflected by the 6-faceted mirror is guided to the imaging lens and the reflecting
mirror mounted in front of the 6-faceted mirror, ultimately reaching the photosensitive drum.
When the 6-faceted mirror rotates at a specific speed, the laser beam on the photosensitive drum
accordingly scans the drum surface.
As the photosensitive drum rotates at a specific speed and, in addition, when the laser beam scans
its surface at a specific speed, an image emerges on the drum surface.
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External device
Video controller PCB
/BDO /VDO VDO /TOP
DC controller PCB
/BDIN /VDO VDO /ENBLO /LONO
BD PCB
Figure 2-3-1
DPICH /ACCO /DECO
Cylindrical lens
Laser unit
6-faceted mirror
Scanner motor
Imaging lens
BD mirror
No. 2 reflecting mirror