Specifications

5. DEVELOPMENT
5.1 OVERVIEW
When the main motor turns on, the paddle roller [A] development roller [B]
the auger [C], and the agitator [D] start turning. The paddle roller picks up
developer in its paddles and transports it to the development roller. Internal
permanent magnets in the development roller attract the developer to the
development roller sleeve.
The turning sleeve of the development roller then carries the developer past
the doctor blade [E]. The doctor blade trims the developer to the desired
thickness and creates backspill to the cross-mixing mechanism.
The development roller continues to turn, carrying the developer to the OPC
drum. 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 negative bias to prevent toner from being
attracted to non-image areas on the drum that may have residual negative
charge. The bias also controls image density.
After turning about 100 degrees more, the development roller releases the
developer to the developer tank. The developer is agitated by the paddle
roller, agitator [D], and the cross-mixing mechanism.
Rotation of the paddle roller and development roller tend to cause air
pressure inside the unit to become higher than the air pressure around the
development unit. A hole, fitted with a filter [F], has been added to the top of
the unit to relieve air pressure and to minimize toner scattering.
[F]
[C][B]
[A] [D]
[E]
1 December 1990
2-26