Konica Minolta bizhub C658 Service Manual page 1810

bizhub C658/C558/C458/C368/C308/C258
7. Only the toner contained in the developer sticks to the electrostatic latent image on the surface of the photo conductor. The developer that
is left on the developing roller is returned to the toner supply screw 2 by the magnetic pole positioning of the developing roller.
8. The part of the circulating developer is collected in the waste toner box through the toner collecting port located at the front side of the toner
supply screw 2. The toner collecting port is provided with a shutter mechanism. Mounting the waste toner box pushes the shutter at the
toner collecting port, opening the toner collecting port. Removing the waste toner box, on the other hand, closes the shutter and toner is
thereby prevented from spilling from the toner collecting port. (For more details, see Auto refining developing system and Waste toner
spillage prevention shutter.)
NOTE
▪ The toner replenishing port of the developing unit is not provided with a shutter mechanism. (The toner hopper section is
equipped with a shutter.)
▪ When removing the developing unit, the developing unit must be held in a horizontal position with care not to allow toner to spill
from the toner replenishing port.
[1]
[5]
[1] Toner supply screw 2
[3] Toner replenishing port
[5] TCR sensor
5.3.3 Auto refining developing system
• The developing unit/Y,M,C,K incorporates the auto refining developing system.
• The bottle of toner cartridge is packed with both toner and carrier and the developing unit is replenished with fresh carrier at the same time
that it is replenished with toner.
• Excess carrier in the developing unit is discharged, thereby inhibiting carrier left in the developing unit from being deteriorated and
maintaining stable image quality for an extended period of time.
[7]
[1] Toner bottle
[3] New carrier
[5] Circulation and agitation
[7] Waste toner box
5.3.4 Developing bias
• The developing bias voltage (Vdc) is applied to the developing roller so that an adequate amount of toner is attracted onto the surface of
the photo conductor.
• In addition to the negative DC component, AC voltage is applied during development to help toner to be attracted more easily to the surface
of the photo conductor. This AC component is applied only while development is taking place. At any other timing, only the DC (-) Vdc is
applied.
• The developing bias (Vdc) is supplied from high voltage unit.
[2]
[4]
[1]
[2]
[3]
[4]
[6]
[5]
O THEORY OF OPERATION bizhub C658/C558/C458/C368/C308/C258 > 5.
[3]
[2] Developing roller
[4] Toner supply screw 1
- -
[2] Toner
[4] Low degree of deterioration of entire carrier
[6] Developing unit
- -
O-35
DEVELOPING SECTION