Canon LBP-2000, Service Manual

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CHAPTER 2
IV. IMAGE FORMATION SYSTEM
A. O u t l i n e
The image formation system is the core of the Printer, and consists mainly of a cartridge and a
fixing assembly.
When the video controller PCB sends the print signal (/PRNT) to the DC controller PCB, the DC
controller PCB drives the main motor (M101) to start rotating the photosensitive drum, developing
cylinder, primary charging roller, and transfer charging roller.
Thereafter, the primary charging roller charges the surface of the photosensitive drum to a
uniform, negative potential; a laser beam modulated according to video signals (/VDO, VDO) is
then directed to the surface of the Photosensitive drum to form a latent image.
The latent image is then turned into a visible image on the developing cylinder using toner; the
resulting visible image is then transferred to paper by the transfer charging roller.
The surface of the photosensitive drum is cleaned by the cleaning blade, which removes re-
sidual toner; it is then charged to a uniform potential by the primary charging roller to be ready for
a new image.
The cartridge of the Printer is equipped with a toner level sensor used to check the level of toner
and the presence/absence of the cartridge.
When the toner inside the cartridge drops below a specific level or the cartridge is not fitted to
the Printer, the fact will be communicated to the video controller PCB.
—Primary charging roller
Photosensitive
drum
Developing cylinder
Cartridge
Transfer
charging roller
Fixing
assembly
Laser beam
Video controller PCB DC controller PCB
/PRNT
/VDO
VDO
Fixing roller
Figure 2-4-1