Fusing Pressure/Retraction Control - Konica Minolta BizHub C360 Service Manual

20. FUSING SECTION
(1) Operation timing
• It starts controlling when the front-edge of the paper reaches to the predetermined posi-
tion before the fusing roller.
• The fusing speed is decelerated so that a loop is formed in the paper between the 2nd
image transfer roller and the fusing roller.
• When the paper loop amount is large, the fusing loop detect sensor is blocked. The fus-
ing speed is increased when the sensor is blocked.
• When the paper loop amount is small, the fusing loop detect sensor is unblocked. The
fusing speed is decreased when the sensor is unblocked.
• Operations explained above will keep the amount of the paper loop within specified
range so the speed difference between the fusing and the paper conveyance for image
transfer will be adjusted.
• The fusing loop control will finish when the back-edge of the paper passes the predeter-
mined position on the back of the transfer roller.
20.3.3

Fusing pressure/retraction control

• To ensure prolonged durability of the fusing belt, the pressure roller is retracted *
the fusing belt during any time other than a print cycle. (The roller is, however, retracted
during a print cycle using envelopes.)
*1: The pressure roller does not completely retract but is slightly pressed to the fusing
belt.
• The pressure or retraction operation between the fusing belt and the fusing pressure
roller is accomplished by driving the fusing pressure roller retraction motor to rotate for-
ward or backward. When the motor rotates, the fan-shaped gear will rotate to move the
pressure roller.
• The fusing pressure roller home sensor detects the fusing pressure roller at its home
position.
• The amount of pressure of the fusing pressure roller is detected with the number of
pulses of the fusing pressure roller retraction sensor.
• When there is no change in the output of the fusing pressure roller home sensor even
after the lapse of a predetermined period of time after the fusing pressure roller retraction
motor has started rotating or when there is no change in the output of the fusing pres-
sure roller home sensor even when a predetermined number of output pulses is counted
of the fusing pressure roller retraction sensor, the machine determines that there is a
pressure/retraction fault and displays the "Trouble code: Fusing roller separation failure"
message.
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Theory of Operation Ver. 1.0 Jul. 2009
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