Konica Minolta bizhub c650 Service Manual page 253

6. Operations
A. Closing the LU door
• The condition of the upper limit sensor signal is checked when the LU door is closed. If
the upper limit sensor is unblocked, the lift-up motor is energized so that lifting of the tray
is started.
• When the upper limit sensor is blocked after the lifting of the tray has been started, the
lift-up motor is deenergized to complete the lifting of the tray.
LU door switch (MS1)
Upper limit sensor (PS2)
Lift-up motor (M1)
B. During a print cycle
• As the paper is consumed for a number of print cycles carried out, the pickup roller grad-
ually lowers and eventually unblocks the upper limit sensor. The lift-up motor is then
energized again and the lifting of the tray is started.
• When the upper limit sensor is blocked, the lift-up motor is deenergized to complete the
lifting of the tray.
• The sequence of these operations is repeated. This maintains the pressure (paper take-
up pressure) between the pickup roller and the paper stack at a constant level regardless
of the level of the paper stack left.
Pick-up Roller
10
Upper limit sensor (PS2)
LU door closed
Upper limit sensor (PS2)
A03NT2C209AA
Theory of Operation Ver. 2.0 May 2007
Paper tray
A03NT2C216AA
Lifting completed
A03NT2C207AA
A03NT2C208AA