Ricoh B245-62 Service Training page 64

Development Bias
White areas: High negative charge (-950V)
Black areas: Discharged by the laser (about -150V)
Development bias (-650V): Forces the negatively-charged toner onto the
discharged areas of the drum.
Applied to the development roller shaft through the drive shaft
Slide 64
This machine uses a negative-negative development system, in which black
areas of the latent image are at a low negative charge (about –154 ±50 V) and
white areas are at a high negative charge (about –950 V).
To attract negatively charged toner to the black areas of the latent image on the
drum, the high voltage supply board applies a bias of –650 volts to the
development rollers throughout the image development process. The bias is
applied to the development roller shaft through the drive shaft.
The development bias voltage (–650 V) can be adjusted with SP 2201 1.
Drive shaft bias terminal
Development roller
64
B245-62 / PD-C4