Document Detection - Canon Color Image Reader-F1 Service Manual

2
Technology > Controls (ADF) > Document Detection > Initial Document Size Detection

Document Detection

■ Outline
This machine detects a document using either of the two methods depending on the print
mode.
• Normal print mode (other than mixed size print mode and banner paper mode)
• Mixed size print mode and banner paper mode
Normal print mode (other than mixed size print mode and banner paper mode)
In the normal print mode, the following Three document detection functions are used:
Function
Document presence/absence Detects whether there is a document on
detection the Detects whether there is a document
on the
Initial document Longitudinal Detects the length of the document placed
sizeabsence direction on the document pickup tray
detection
Lateral Detects the width of the document placed
direction on the document pickup tray.
Mixed size print mode and banner paper mode
In the mixed size print mode and banner paper mode, the following three document
detection functions are used:
Function
Document presence/ Detects whether there is a document on the
absence detection document pickup tray.
Document length Detects the document length according to
detection the distance from the position where the
read sensor (SR2) turns on to the position
where the read sensor (SR2) turns off.
2 Technology > Controls (ADF) > Document Detection > Initial Document Size Detection
Description Description
Document set sensor
(SR5)
Document length
sensor
1/2(SR7/SR10)
Document width
volume 1(VR1)
Description Description
Document set sensor
(SR5)
Read sensor(SR2)
■ Initial Document Size Detection
The document length sensor 1 (SR7) and document length sensor 2 (SR10) detect the
longitudinal size of the document placed on the document tray, and the document width
volume (VR1) and A4R/LTRR identification sensor (SR8) detect the lateral size of the
document.
When a document is placed on the document tray, detection levers of the two document
length sensors move the light shielding plate to prevent light from passing through the photo
interrupter.
If the slide guide is adjusted to the document size, the resistance of the document width
volume mounted inside the document tray changes to detect the document size.
Document sizes are determined by the combination of the ON/OFF states of document length
sensors, the combination of ON/OFF states of document width volume, and the combination
of ON/OFF states of A4R/LTRR identification sensor.
SR8
T-2-6
T-2-7
SR7
SR10
VR1
2-16
F-2-29
2-16