Ccd Adjustment - Canon ImageRunner iR8500 Series Service Manual

Chapter 6
Output
unit C
Light-
receiving
Output
unit D

6.2.7 CCD Adjustment

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.
6-4
Direction of charge transfer
Clock pulse C
Transfer unit C
7500 7499 7498 7497 3754
unit
Clock pulse D
Transfer unit D
Direction of charge transfer
Direction of charge transfer
Transfer unit A
3753 3752 3751 3750 3749 3748 3747
Transfer unit B
Direction of charge transfer
F-6-7
Clock pulse A
Output
unit A
CCD
shift
4 3 2 1
pulse
Output
unit B
Clock pulse B
0006-9676