Ricoh FT 4015 Service Manual page 32

DEVELOPMENT 20 December 1996
5. DEVELOPMENT
5.1 OVERVIEW
[D]
[C]
[A]
[E]
[B]
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When the main motor turns on, the development roller [A] and two agitators
[B] and [C] start turning.
There are permanent magnets in the development roller which attract the
developer particles (which are about 50 µm in diameter) to the roller. The
turning sleeve of the development roller carries the developer past the doctor
blade [D] which trims the developer to the desired thickness.
The development roller sleeve continues to turn, carrying the developer to the
drum [E]. When the developer brush contacts the drum surface, the
negatively charged areas of the drum surface attract and hold the positively
charged toner. In this way, the latent image is developed.
The development roller is given a suitable negative bias for preventing toner
from being attracted to the non-image areas on the drum which may have a
residual negative charge. The bias also controls image density.
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