Ricoh C249, Service Manual

Page: 183 / 486

DRUM
SM 6-37 C249
Detailed
Des
cription
s
The number of drum idling rotations depends on the internal temperature of the
machine and the time period of machine’s inactivity, as shown in the following
table.
NOTE: 5) User Tools 4-11 can change the number of rotations for each of these
conditions.
6) The drum rotations speed during idling is fixed at 30 rpm.
Period/
Temperature
Less than 2
hours
2 to 4 hours 4 to 24 hours
Over 24
hours
High
(28degree or above)
0 0 2 3
Normal
(15 to 28 degree)
0 0 2 3
Low
(below 15degree)
0 2 3 3
6.5.7 DETECTION OF MASTERS ON THE DRUM
[A]: Drum master sensor
[B]: Black patch on the screen
[C]: Black patch on the clamper
•
The drum master sensor [A] detects whether there is a master on the drum.
•
When there is a master on the drum, the black patch [B] is covered and the
sensor detects the light reflected from the master. When there is no master on
the drum, the black patch [B] is exposed. The black patch does not reflect light
back to the sensor. Because of this, the master eject process can be skipped
when a new master is being made, if no master is detected on the drum.
•
The drum master sensor uses the black patch [C] on the clamper for jam
detection. (
!
6.7.3)
C238D028.WMF
[A]
[B]
[C]