Canon iR1200 Series Service Manual page 157

7.1 Construction
7.1.1 Outline
The machine is not equipped with a paper width detection mechanism. It uses center reference, in which paper moves
centered through the pickup/feeding/delivery path.
The source of paper may be from any of two: cassette and manual feed tray. Once picked from the cassette or the
manual feed tray, the paper is corrected so that any skew is removed by the registration shutter and is sent as far as
the registration roller. Thereafter, the paper is controlled so that its leading edge matches the leading edge of the
image on the photosensitive drum by means of the paper leading edge sensor (PS102); it then is moved through the
transfer, separation, feeding, and fixing assemblies to reach the delivery tray.
The machine is equipped with 5 sensors to monitor the movement of paper; the names and the functions of these
sensors are as follows:
Notatio
n
PS3
PS4
PS101
PS102
PS103
Name
Delivery sensor
Manual feed tray paper
sensor
LGL paper sensor
Paper leading edge sensor
Cassette paper sensor
T-7-1
Function
Detects the state of paper in the delivery
assembly.
Detects the presence/absence of paper in the
manual feed tray.
Detects paper inside the cassette to see if it is
of LGL size.
Detects the leading edge and trailing edge of
paper to measure its length. Also, it controls
the timing of activation of the laser.
Detects the presence/absence of paper in the
cassette.
Chapter 7
0006-2880
7-1