Development; Overvlew; Overview - Ricoh FT5540 Service Manual

31 August 1989

5. DEVELOPMENT

5.1 OVERVIEW

When the main motor sends a signal to the SSR PCB, the development motor is energized.
When it turns on, the paddle roller [A] and development roller [B] 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 [C]. The doctor blade trims the developer to the desired thickness and creates backspill
to the crossmixing mechanism.
The development roller continues to turn, carrying the developer to the selenium drum [D].
When the developer brush contacts the drum surface, the positively charged areas of the
drum surface attract and hold the negatively charged toner. In this way, the latent image is
developed.
The development roller is given a positive bias to prevent toner from being attracted to the
non-image areas on the drum that may have residual positive charge. The bias controls image
density.
After turning another 100 degrees, the development roller releases the developer to the
developer tank.
The developer is agitated by the paddle roller and the crossmixing mechanism. The knocking
solenoid vibrates the upper cover of the developer unit to prevent toner buildup.
2-26