Development Bias - Ricoh B121 Service Manual

DEVELOPMENT

6.9.4 DEVELOPMENT BIAS

[B]
[A]
B121D945.WMF
This machine uses a negative-positive 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 [A] through the drive shaft [B].
The development bias voltage (–650 V) can be adjusted with SP2-201-1.
B121 Series/B259 Series 6-40 SM