Ricoh JP5000 Service Manual page 100

PRINTING AND PRESSURE CYLINDER
2.7.4 PRINTING PRESSURE CAM SHIFTING FOR A3/A4 SIZE
MASTERS
[E]
[B]
Front
In this model, printing on a large master (A3 sized cut) or a small master (A4
sideways sized cut) is selected automatically (only if the optional ADF is used).
When the CPU detects that A4 sized paper (or 8 1/2" x 11") or smaller has been
set in the sideways feed direction on the paper table, and two or more originals
have been placed in the ADF, the machine automatically makes the smaller
master.
NOTE: The master sizes are as follows:
Large Master: 320 x 530 mm (320 x 540 mm for U.S.A. models)
Small Master: 320 x 355 mm
Since the small master does not cover all the printing area of the drum screen, the
last original's image is always made on a large master. This is to prevent the drum
screen from drying if the next printing job is not done for a long time.
Therefore, a small master is not made when there is only one original in the ADF,
even when printing on small paper. (In the Platen mode, the small master is never
made because the machine cannot detect the number of originals.)
Based on the master size, the correct printing area is applied automatically. The
printing pressure cam [B] includes two shapes (for A3 printing and for A4 sideways
printing) in one part.
When switching the printing area, the pressure cam shift motor [A] turns. The
switching plate [E] moves the cam shaft from side to side through some gears,
which moves the printing pressure cam at each end of the shaft from side to side.
The rack moves until either the A4 cam sensor [D] or A3 cam sensor [C] is
activated.
[A]
[C]
[D]
C229D070.WMF
2-72
1 July, 1998
Rear
[B]