Reader Assembly - Canon imageRUNNER ADVANCE 4551i Service Manual

Symbol
SL2 Stamp solenoid
CL1 Pickup clutch
CL2 Registration clutch

Reader Assembly

■ Magnification Ratio
● Changing the Magnification Ratio in the Horizontal Scanning Direction
When using the reading mode of the reader / When using the ADF
Reading in the horizontal scanning direction is performed at 100% size. Changes to the magnification ratio are processed by the
Main Controller PCB.
● Changing the Magnification Ratio in the Vertical Scanning Direction
As the magnification change in vertical scanning direction, the following operation is performed according to original reading
method and difference in magnification.
1. Magnification change operation when using the reading mode of the reader
Data is processed by the Main Controller PCB according to the magnification ratio.
Example) In the case of reducing the magnification to 25%: Original reading speed of 260 mm/sec, original reduced to 25%
(1/4 size) by the Main Controller PCB
Example) In the case of 100%: Original reading speed of 260 mm/sec
Operation description
Original reading speed (mm/
sec)
Digital magnification process-
ing in the Main Controller PCB
(%)
■ Original Size Detection
● Overview
This machine determines the size of an original by the combination of the measurement results of the reflected light at particular
points of the Reflection Sensor and Reading Sensor. Furthermore, two points are measured for each size to perform accurate
detection even if the original is moved when the ADF is closed.
• Horizontal scanning direction: Reading Sensor (AB configuration: 12 point measurement, inch configuration: 6 point
measurement)
• Vertical scanning direction: Reflection Photosensor (AB configuration, inch configuration: 1 location, AB/inch configuration:
1 location (shipped with position of Original Sensor 1, but can be changed the position of Original Sensor 2 as necessary))
The original size is determined using the following procedure:
1. Search of external light (horizontal scanning direction only)
The sensor level at each detection position in the horizontal scanning direction is measured while the LED is OFF.
2. Detection of output level of each sensor
The LED of the Reading Sensor Unit is turned ON to measure the sensor level at each detection position in the horizontal
scanning direction.
Furthermore, the Reflection Photo Sensor LED for the vertical scanning direction is turned ON to measure the sensor output.
The original size is determined by the combination of these outputs.
● Control description
In horizontal scanning direction, sensor level of each original detection position is measured by moving the Scanner Unit to the
detection position shown in the figure in relation to the original setting position. In the vertical scanning direction, the original size
is determined using the Original Sensor 1 and 2.
Name
Stamps on a document.
Transmit the Pickup motor drive to the Pickup roller and the Feed
roller.
Transmit the power of the Pickup motor to the Lower registration
roller.
25 % to 50 %
260
25 to 50
46
Role
Magnification
50.1 % to 199.9 %
260
50.1 to 199.9
2. Technology
200 % to 400 %
260
100 to 200