Konica Minolta Bizhub 20p Service Manual page 51

(3) Development
Toner is attracted to a printed-image area on the exposure drum where surface potential is
lowered due to exposure.
By controlling developing bias voltage supplied to the develop roller, the amount of toner
taken to the drum is adjusted to keep printing density constant.
Charging
Laser beam
400 V to 315 V
150 V
(Changes depending on use condition)
850 V
Toner
Develop roller
Fig. Ref. 2-17
<Flow up of toner to the development process>
Toner adheres to the charged develop roller. Such adhered toner is adjusted to an even
thickness, and is attracted to an exposed area on the exposure drum.
Blade
Exposure drum
Develop roller
Fig. 2-18
2-19
Confidential