Konica Minolta bizhub c450 Service Manual page 76

Theory of Operation Ver. 1.0 Mar. 2005
B. Pressure position changing mechanism
• To extend the service life of the PC Drum/Y, M, C, the pressure position of the 1st Image
Transfer Roller is changed between the monochrome mode and the color mode. In the
monochrome mode, the 1st Image Transfer Roller/Y, M, C is left in the retracted position
and the PC Drum/Y, M, C is stopped.
• The pressure position is changed by varying the pulse count of the 1st Image Transfer
Pressure/Retraction Motor, which results in the pressure cam stop position being varied.
The pressure position of the Image Transfer Roller is also changed by changing the stop
position of the Sliding Plate.
Color mode:
• The pressure position of the Image Transfer Roller is where the PC Drum is in contact
with the Transfer Belt for all four colors of toner.
Monochrome mode:
• The pressure position of the Image Transfer Roller/Y, M, C is where the PC Drum/Y, M, C
leaves the Transfer Belt. While that of the Image Transfer Roller/K is where the PC Drum/
K is in contact with the Transfer Belt. This allows the PC Drum/Y, M, C to remain station-
ary in this mode.
Retracted
Position
Monochrome
Mode
Color Mode
Retraction Roller
Cam Position A
Y M
Cam Position B
M
Y
Cam Position C
Y M
Transfer Belt
1st Image
Transfer
Roller
14. Transfer Corona section
Sliding Plate
Bk
C
Bk
C
C Bk
Lifting Mylar
PC Drum
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