Olympus OEP-3, Service Manual

Page: 166 / 176

5-12
OEP-3 V1 (UC)
With the conventional UP-5500 series, the paper chuck opens and closes by an approximate 60
d
rotation
of the platen.
The reason for using a new direct chuck mechanism is that it is preferable to be able to close the chuck
with the platen stopped in order to reserve chuck reliability on the assumption that multiple kinds of
media have a different coefficient of friction.
The chuck is opened during rotation as usual.
The direct chuck mechanism can be operated only when both platen and chuck timing cam are at the
home position, as described below.
The head cam is rotated at 120
d
. This motion is transmitted from chuck link A to chuck link B, to chuck
link C, then it directs the chuck arm to rotate the chuck timing cam at 60
d
. Therefore, the chuck timing
cam turns the platen shaft and the chuck cam rotates. Consequently, the spring force incorporated in the
chuck base closes the chuck.
As mentioned above, the chuck timing cam is rotated at 60
d
to reproduce the same state as a 60
d
rotation
of the platen.