Summary Of The Printing Process - Xerox Phaser 6360 Service Manual

Summary of the Printing Process

Phaser 6300/6350/6360 Color Laser Printer Service Manual
The printing process is summarized in the following steps. While reading the
summary, refer to the figures on pages 2-2, 2-5, and 2-6. These diagrams
show process flow and indicate the relative position of the components
involved. The diagrams also include reference numbers that correspond to
each numbered step.
1. Charging: The charge roller (RTC) is negatively charged by the High
Voltage Power Supply (HVPS) and is kept in contact with the drum
surface to provide a uniform negative charge on the drum as it rotates at a
constant speed. This occurs simultaneously for YMCK. The refresher is a
conductive brush that is also negatively charged by the HVPS to pick off
any toner particles left on the drum after image transfer to the IDT.
2. Exposure: The Laser Unit uses a system of mirrors and lenses to scan
the drum surface in response to image data from the Image Processor.
Where the laser exposes (writes) the drum surface it reduces the negative
charge to form an invisible latent image. This process is preformed
simultaneously for YMCK.
3. Development: Toner is electrostatically attached to the invisible latent
image on the drum surface to form the visible image on the drum. Toner is
fed into the developer using the agitator in the Toner Cartridge and auger
system in the Toner Cartridge Holder. The toner and the carrier in the
developer form a homogeneous layer on the magnet roller in the
Developer Assembly. The magnet roller turns against the surface of the
drum and is kept at a constant negative potential. At areas on the drum
surface where the negative charge has not been reduced by the impact of
laser light, potential between the drum and the toner particles is lower
than that between the magnet roller and the toner particles. At areas
where the drum charge has been reduced, the potential between the
particles and drum is higher than between the magnet roller and toner
particles are attracted to the drum. A thin semiconducting sleeve on the
magnet roller is vibrated by an AC voltage to encourage migration of the
toner particles to the drum. When the toner particles attach to the drum,
the negative charge of the particles reduces drum potential at that point,
thus reducing the attraction of additional toner particles. This process
occurs simultaneously for YMCK.
The electrostatic characteristics of the carrier deteriorate due to surface
contamination by toner or scratches during agitation. In order to maintain
electrostatic characteristics, a slight amount of carrier is mixed with the
toner in the toner cartridge.The deteriorated carrier is collected in the
Imaging Unit.
Theory of Operation
2-3