Developer Flow - Konica Minolta BizHub C360 Service Manual

11. DEVELOPING SECTION
11.3.2

Developer flow

1. Toner replenished via the toner replenishing port located at the front side of the
machine is fed to the toner supply screw/lower. It is then mixed with carrier by the
toner supply screw/lower. The state of toner mixed with the carrier is called the
developer.
2. The developer is conveyed toward the rear of the unit, while being agitated and
electrically charged, by the toner supply screw/lower.
3. The TCR sensor installed on the underside of the developing unit detects toner-to-
carrier (T/C) ratio during this time. If the T/C ratio is lower than a predetermined
value, toner is replenished.
4. The developer, fed to the rear of the developing unit, is conveyed further onto the
toner supply screw/upper.
5. The developer fed to the toner supply screw/upper is conveyed onto the developing
roller because of the magnetic pole positioning of the developing roller.
6. The doctor blade then controls the height of the developer brush to ensure that the
developer on the developing roller levels out.
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/upper by the magnetic pole positioning
of the developing roller. With these operations repeatedly performed, the developer
is circulated through the developing unit.
8. With only the developing unit/K, 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/upper. The toner collecting port is provided with a shutter mech-
anism. 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 the paragraphs that describe the auto refin-
ing developing system and toner collecting section.)
NOTES
• The toner replenishing port of the developing unit is not provided with a shutter
mechanism (but the toner hopper section is provided with a shutter).
• When removing the developing unit, the developing unit must be held in a horizon-
tal position with care not to allow toner to spill from the toner replenishing port.
TCR sensor board
76
Theory of Operation Ver. 1.0 Jul. 2009
Developing roller
Doctor blade
Toner replenishing port
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