Canon imageRunner 2022, Service Manual

Page: 157 / 418

Chapter 4
4-11
4.3.2.3 Analog Control Performed by the CIS (iR2030i/iR2030/iR2025i/iR2025/iR2022i/iR2022)
0017-2630
iR2022i / iR2025 / iR2030 / iR2022
The flow of analog image processing performed by the contact image sensor (CIS) is as follows:
The light reflected by the original is collected by the rod lens array.
- The light is received by the CMOS sensor array.
- The CMOS sensor array converts the received light to an electric signal and outputs it.
The CMOS sensor array consists of four channels (units).
Each channel is provided with an output correction table to output an image signal after performing gain correction for the input brightness signal.
F-4-18
- After replacing the contact image sensor (CIS), go through the following steps to perform inter-channel output correction:
1) Enter the service mode.
Sequentially press the Additional functions key, 2 key, 8 key, and Additional functions key on the operation panel.
2) Press the arrow key on the touch panel to display "TEST MODE".
3) Press [OK].
4) Press the [2] key to display "SCAN TEST".
5) Press the [1] key to display "SHADING".
6) Press [OK].
After completion of the above procedure, the contact sensor output is compensated and parameters are set automatically.
After completion of automatic adjustment, "OK" is displayed.
4.3.3 Enlargement/Reduction
4.3.3.1 Magnification Change in Vertical Scan Direction
0017-2631
iR2022i / iR2025 / iR2030 / iR2018 / iR2022 / iR2018i
In the Book mode or when the ADF is used
In the vertical scan direction, the image is read at 100%. Magnification is changed by processing data on the image processor PCB.
4.3.3.2 Magnification Change in Horizontal Scan Direction
0017-2632
iR2022i / iR2025 / iR2030 / iR2018 / iR2022 / iR2018i
In the horizontal scan direction, magnification is changed as follows depending on the selected magnification rate:
1) When magnification is reduced to 50-99%
a. In the Book mode
Data is processed on the image processor PCB with the original scan speed held at 118 mm/sec.
b. When the ADF is used
The original feed speed is changed within the range of 118 mm/sec to 236 mm/sec depending on the selected magnification rate. Data is not processed on the image
processor PCB.
2) When magnification is increased to 100-200%
The original scan speed (in the Book mode)/original feed speed (when the ADF is used) is changed within the range of 118 mm/sec to 59 mm/sec depending on the
selected magnification rate. Data is not processed on the image processor PCB.
4.3.4 Detecting the Size of Originals
4.3.4.1 Outline
0017-2633
iR2022i / iR2025 / iR2030 / iR2022
Dr
iver circuit
4
CCD channel x 4
3
2
1
1872 pix
els
7488 pix
els