Oki MC160MFP Maintenance Manual page 43

Oki Data CONFIDENTIAL
14.3 Operation 14.3 Operation
14.3.1 2nd transfer roller pressure/retraction control
14.3.1 2nd transfer roller pressure/retraction control
• In color printing, the toner image of each color of toner is transferred to the transfer belt
(thus a total of four times to cover the four colors of toner). Pressure/retraction control
with respect to the transfer belt is therefore provided for the 2nd transfer roller.
• In the standby state, the 2nd transfer roller is in a position retracted from the transfer belt.
• The pressure/retraction operation is performed by the Transport motor (M1), 2nd image
transfer pressure/retraction solenoid (SD4), and the pressure/retraction clutch.
• When the 2nd image transfer pressure/retraction solenoid (SD4) is energized, drive from
the Transport motor (M1) is transmitted to the pressure/retraction clutch.
A. Pressure sequence
1. Drive from the Transport motor (M1) is transmitted to the drive gear.
2. Rotation of the drive gear is transmitted to the Pressure/retraction clutch.
3. When the 2nd image transfer pressure/retraction solenoid (SD4) is energized, the
Pressure/retraction clutch rotates a half turn. This moves the Pressure slider.
4. When the Pressure slider is moved, ribs on the Pressure slider push up the 2nd
transfer assy.
5. When the 2nd transfer assy is pushed up, the 2nd transfer roller is pressed up
against the transfer belt.
2nd image transfer pressure/retraction solenoid (SD4)
Ribs
Pressure slider
44292401TH Rev.1
2nd transfer assy
Pressure/retraction clutch
A034T2C535AA
(1) Retraction sequence
1. When the 2nd image transfer pressure/retraction solenoid (SD4) is energized in the
condition in which the 2nd transfer roller is pressed against the transfer belt, the
Pressure/retraction clutch rotates a half turn. This moves the Pressure slider.
2. When the Pressure slider is moved, the 2nd transfer assy, which has been pushed
up by the ribs on the Pressure slider, lowers.
3. When the 2nd transfer assy lowers, it allows the 2nd transfer roller to be retracted
from the transfer belt.
2nd image transfer pressure/retraction solenoid (SD4)
Ribs
Pressure slider
14.3.2 14.3.2 2nd transfer roller cleaning 2nd transfer roller cleaning
• DC positive and negative transfer bias voltages are alternately applied to the 2nd transfer
roller. This allows toner residue on the surface of the 2nd transfer roller to be transferred
back to the transfer belt, thus cleaning the 2nd transfer roller.
• The toner transferred back to the transfer belt is collected by the cleaning blade.
Transfer belt
A. Operation timing
• The machine performs a cleaning sequence if it detects a sheet of paper having a length
shorter than the length of the specified paper type.
• The cleaning sequence is also carried out during a resetting sequence following a paper
misfeed and the opening of the door during a print cycle.
COMPOSITION/OPERATION
2nd transfer assy
Pressure/retraction clutch
A034T2C536AA
2nd transfer roller
4139to2082e1
42 /