Ricoh JP5000 Service Manual page 87

1 July, 1998
Paper feed timing must be synchronized with the pressure cylinder rotation, so the
registration motor on timing is maintained by the feed start sensor [C].
A short time after the pressure cylinder [D] starts rotating, the actuator [A] on the
rear of the pressure cylinder activates the sensor. A pre-determined duration later
(see Note 1 below), the registration motor starts turning to feed paper to the drum
and pressure cylinder. After the printing paper is caught between the drum and the
pressure cylinder, the registration motor stops.
NOTE: 1) The registration motor rotation speed is constant. However, when the
operator selects a higher or lower printing speed (to change the copy
image density), the drum and pressure cylinder rotation speed changes.
The registration motor must feed the paper at the correct time for the
leading edge to be caught by the paper clamper on the pressure
cylinder. Therefore, the registration motor start timing after the paper
feed start sensor is activated depends on the printing speed selected.
2) There are two actuators: [A] and [B]. The actuator [B] is used to
maintain the paper feed motor start timing. (This was mentioned earlier,
in 'Paper Feed Mechanism'.)
Image Up/Down Shift Mode
In addition, the registration motor start timing is changed by pressing the image
position keys on the operation panel (this is the image up/down shifting mode). If
the paper feed timing is delayed, the image is shifted forward.
NOTE: The leading edge of the paper must be precisely caught by the paper
clamper on the pressure cylinder after leaving the registration rollers. When
the image up/down shifting mode is used, the position of the pressure
cylinder changes through the image up/down mechanism, so the
registration motor start timing must change. (The drum stays at home
position.) For details of the mechanism, refer to "2.10 Image Up/Down
Shifting" section.
[D]
[A]
2-59
[B]
Rear
View
[C]
C229D119.WMF
PAPER FEED