Canon Color imageRUNNER C4580, Service Manual

Page: 182 / 851

Chapter 6
6-15
Note:
Change in the Signal (ADF open to closed)
change: no
other: yes
6.3.4.3 Overview of Operation
1) Standby
No.1 mirror base: shading position
xenon lamp: off
original sensor: off
F-6-20
2) ADF Opened
No.1 mirror base: moves to original detection position
xenon tube: off
original sensor: off
F-6-21
3) ADF Closed
3-1) When the ADF is brought to 25 deg, the area covered by an original will be blocked from external light;
therefore, the machine will assume the absence of an original at points that detect external light (external
search).
The ADF open/closed sensor 2 identifies the condition as being "closed," and the machine starts original
size identification.
At this position, B5, B4, A4, and A3 are excluded from the list of possible sizes.
3-2) The machine executes an external light search: for main scanning direction, it turns on the xenon lamp to
check its light (reflected) at 4 points using the CCD; for the sub scanning direction, the machine checks
the state of the original sensor.
F-6-22
Original detection position
Xenon lamp
Original sensor
Reader unit
ADF
Point of detection 1
Point of detection 2
Point of detection 3
Point of detection 4
Copyboard
glass
(external
light)
(external
light)