Oce 3121 Technical & Service Manual page 402

Set indication
Original Set indicator
Document
Original
Document tray
Original tray
Measuring the Size of Documents
Outline
The measurements of the document are monitored to obtain correct control
and, for fax applications, for use in the communication protocol.
Document size (length in feeding direction)
The length of a document, in the feeding direction, is checked by the sensor
(S3) and by the clock sensor (S11).
The registration paper sensor checks the leading edge and the trailing edge of
an original, while the registration roller clock sensor checks the rotation of the
registration roller while the original moves past it. (The RDF controller com-
putes the rotation into a length.)
RDF controller PCB
Registration paper sensor
S1
S3
S11
Registration roller clock sensor
Registration roller
ed.1 10 RDF 521