Konica Minolta bizhub 500 Service Manual page 185

4. PAPER FEED SECTION
(2) Paper feed roller unit up/down mechanism
On the inside of the paper feed gear /3 [2], the cam [3] is provided. While in the standby, the cam pushes the lift-
up shaft [1]. The lift-up shaft is in contact with the paper feed roller unit [5] and it lifts up the paper feed roller unit
while it is being pushed by the cam. When the paper feed gear /3 rotates, the pressure by the cam on the lift-up
shaft is released and the paper feed roller unit goes down. In this way, the paper feed roller unit goes up and
down while the paper feed gear /3 is rotating a full turn to pick up paper.
[2] [3]
[1] Lift-up shaft
[2] Paper feed gear /3
[3] Cam
B. Paper feed operation
A specified period of time after a start signal from the main body turns ON, the feed motor (M150), the feed
clutch (CL151) and the pick-up solenoid (SD151) turn ON to pick up paper from the tray. SD151 turns OFF a
specified period of time after that. However, it turns ON and OFF according to the paper feed request signal to
pick up the second and succeeding sheets of paper. Paper thus picked up is conveyed to the PC by the con-
veyance roller to be further conveyed to the registration section of the main body through the vertical convey-
ance roller in the PC.
The conveyance roller is provided with CL151 and, when the registration sensor (PS1) of the main body detects
the leading edge of paper and turns ON, it turns OFF a specified period of time after that to stop the conveyance
roller and the paper feed roller unit. At this time, the registration section of the main body stops temporarily to
control the registration and all the rollers that are positioned upstream of the registration roller also stop. In this
way, paper thus supplied is put in the standby condition in each position of the registration section, the convey-
ance path and the LU exit section.
When a print signal is received, a specified period of time after that, each roller in the conveyance path and
CL151 turn ON to resume the conveyance of paper.
6
[4]
[1]
[4] Paper feed gear
[5] Paper feed roller unit
Theory of Operation Ver1.0 Feb.2006
[5]
[1]
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