Ricoh Gestetner 5450, Service Manual, Page: 89 / 315

1 July, 1998 PAPER FEED
2-61
Detailed
Descriptions
2.6.5 PAPER FEED CONTROL MECHANISM
The paper feed timing around the registration roller [A] is monitored by two different
photo-sensors. The first is the paper registration sensor [C], which is located before
the registration roller. The second sensor is the paper feed timing sensor [B], which
is located after the registration roller.
The paper registration sensor [C] detects the paper arriving at the registration
roller. The paper feed motor start timing is determined by this sensor. When the
paper comes into contact with the rollers, the motor remains stopped to create a
buckle in the paper to obtain precise paper registration and to prevent paper skew.
The motor starts turning a pre-determined period after the sensor is activated by
the paper. The sensor is also used to detect jams.
The paper feed timing sensor [B] is also used to detect paper jams. It is also used
to compensate for delays in paper feed caused by slippage at the registration
roller, as described below.
The CPU monitors the paper feed timing sensor after the registration motor starts
turning. If the sensor turns on late, the CPU determines that there has been
slippage at the registration roller. Depending on the size of the delay, the
registration motor speeds up to recover the delay.
C229D060.WMF
[A]
[B]
[C]
Rear
Front