Canon Color iR C3480, Service Manual

Page: 184 / 774

Chapter 5
5-10
5.3.2.2 Analog Control Inside the Contact Image Sensor (CIS)
0013-8581
Color iR C3380G / Color iR C2880G / Color iR C3380i / Color iR C3380 / Color iR C2880i / Color iR C2880 / iR C3480 / iR C3480i / iR C3080 / iR C3080i / iR
C2550
The contact image sensor (CIS) read images in keeping with the following flow of analog image processing:
uses a rod lens array to collect light reflected by the original.
-> receives light using a CCD array.
-> uses the CCD array to turn the light into an electrical signal (photo conversion), thus preparing output.
The machine's CCD array consists of 16 channels (units) in total. Each of these channels is equipped with an output correction table, and generates image signals
after gain correction on input intensity signals.
F-5-14
If any of the following occurs, be sure to execute the following service mode item to correct the output among the channels:
- there is a difference in the output of the image density among channels after replacement of the contact image sensor (CIS).
- the CCD-LUT setting is not 0 after replacement of the reader controller PCB.
Service Mode:
- setting CIS unit gain correction data
COPIER>OPTION>BODY>CCD-LUT
- CCD Gain Fine Correction
COPIER>FUNCTION>CCD>LUT-ADJ2
(making adjustments using a D-10 chart)
5.3.3 Enlargement/Reduction
5.3.3.1 Changing the Magnification in Main Scanning Direction
0013-8582
Color iR C3380G / Color iR C2880G / Color iR C3380i / Color iR C3380 / Color iR C2880i / Color iR C2880 / iR C3480 / iR C3480i / iR C3080 / iR C3080i / iR
C2550
Book mode, ADF in use
The machine reads the original in main scanning direction at 100%; any change needed in magnification is made by processing data on the main controller PCB
(main).
5.3.3.2 Changing the Magnification in Sub Scanning Direction
0013-8583
Color iR C3380G / Color iR C2880G / Color iR C3380i / Color iR C3380 / Color iR C2880i / Color iR C2880 / iR C3480 / iR C3480i / iR C3080 / iR C3080i / iR
C2550
Book mode, ADF in use
The machine reads the original in sub scanning direction at 100%; any change needed in magnification is made by processing data on the main controller PCB
(main).
Dr
iver circuit
1
9
10
8
12
13
11
15
16
14
1
9
10
8
12
13
11
15
16
14
1
9
10
8
12
13
11
15
16
14
CCD channel (x 16)
468 pix
els
Output
Input
Ideal output characteristics
Actual output
characteristics