Ricoh LDD250, Service Manual

Page: 398 / 459

PAPER FEED
C262/C265 6-76 SM
6.8 PAPER FEED
6.8.1 OVERVIEW
Feed and Separation
The top sheet of paper on the paper table is first fed by the pick-up roller [D]. Then,
it is separated by the feed roller [F] and the friction pad [E], and fed to the
registration rollers [A]. The upper and lower registration rollers feed the sheet to the
drum.
An independent stepper motor (the paper feed motor [C]) drives the paper feed
roller and paper pick-up roller. This allows more precise control than the usual main
motor/magnetic clutch system.
Feed/Separation Pressure
The strength of the paper feed roller and the friction pad pressure against the
paper depend on the paper type selected at the operation panel. Each component
has a separate dc motor to adjust the pressure. The operator is free from
complicated adjustments for paper feed and separation pressures.
There are two friction pads [E]. The machine automatically selects the correct one
for the paper type that is set by the user.
Registration
Also, an independent stepper motor (the registration motor [B]) controls the
registration roller. The registration roller synchronizes paper feed timing with the
image on the drum. The registration roller starts rotating after the paper has come
in contact with the rollers and has been aligned.
Paper feed timing around the registration roller is monitored by two different photo-
sensors. One is located before the registration roller, and the other is after the
registration roller. These sensors are also essential for paper feed control.
C262D068.WMF
[A]
[B]
[C]
[D] [E] [F]