Konica Minolta bizhub C250 Service Manual page 90

Theory of operation ver. 3.0 Aug. 2006
14.3.3 2nd image transfer roller pressure mechanism
• The 2nd image transfer roller has the pressure/retraction mechanism which presses to
and retracts from the transfer belt so the patterns made on the transfer belt except by
printing (such as detection pattern during image stabilization) will not affect the 2nd
image transfer roller.
A. Pressure/retraction operation
1. Drive from the 2nd image transfer pressure/retraction motor is transmitted through
a gear train to the drive gear.
2. The drive gear rotates to rotate the cam half way. releasing the pressure lever will
press the 2nd image transfer roller to the transfer belt.
3. At this time, the 2nd image transfer pressure position sensor detects whether the
2nd image transfer roller is located at the pressure position.
4. The cam will rotate half way when the motor turns ON again. Moving the pressure
lever down will move the 2nd image transfer roller to the retraction position and will
stop.
2nd image transfer pressure/
retraction motor (M5)
2nd image transfer
pressure position sensor (PC7)
Drive roller
Pressure lever
• Operation timing
Main motor (M1)
2nd image transfer pressure/
retraction motor (M5)
2nd image transfer pressure
position sensor (PC7)
When pressed
2nd image
transfer roller
Cam
4038T2C167AA
Start key ON
14. Transfer corona section
Pressure lever
4038T2C022DA
When retracted
Paper moves past 2nd image transfer roller
Cam
4038T2C168AA
4038T2C136AA
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