Canon ImageRunner iR8500 Series, Service Manual, Page: 314 / 1122

Chapter 6
6-4
F-6-7
6.2.7 CCD Adjustment
0006-9676
iR105i/iR105+ / iR9070
As mentioned, the CCD consists of two segments. If the CCD gain characteristics differ between its first half and its last half, the image density read on
the left side and the right side of its joint will differ, causing a discrepancy in density in the image.
If the reader controller PCB or the CCD/AP PCB is replaced or when the CCD correction data stored in the S-RAM of the reader controller PCB is lost,
CCD correction must be executed in service mode, thereby making the gain around the joint between first half and lat half virtually the same. The
parameters that occur after adjustment will all be stored in the S-RAM on the reader controller PCB.
The following three methods may be used for adjustment:
SERVICE MODE:
A. COPIRE> FUNCTION> CCD> CCD-ADJ (shading auto correction)
Use it to execute shading corretion for the CCD.
B. COPIRE> FUNCTION> CCD> LUT-ADJ (gain simple correction)
Use it to execute CCD gain correction with a blank sheet.
C. COPIRE> FUNCTION> CCD> LUT-ADJ2 (gain full correction)
Use it if CCD simple correction fails. Use it with the 10-Gradation Chart.
Use any of the above methods as needed.
Start with A, and then B; if both fail, execute C. Do not move to B or C without correctly executing A.
Direction of charge transfer Direction of charge transfer
Direction of charge transfer Direction of charge transfer
3750 3749 3748 3747 3751 3752 3753 3754 7500 7499 7498 7497 4 3 2 1
Output
unit A
Output
unit B
Output
unit C
Output
unit D
CCD
shift
pulse
Transfer unit A
Clock pulse B Clock pulse D
Clock pulse A Clock pulse C
Transfer unit B
Transfer unit C
Transfer unit D
Light-
receiving
unit