Canon DADF-AA1, Service Manual

Page: 93 / 110

Chapter 5
5-7
5.3.1.8 Adjusting the White Level
0024-7057
1) Touch the following notations in sequence to bring up the Adjustment
screen:
1 COPIER
2 FUNCTION
3 CCD
2) Place paper (of the type most often used by the user) on the copyboard
glass, and close the DADF.
3) Press [DF-WLVL1] to highlight.
4) Press [OK].
Automatic adjustment starts; if it ends successfully, the screen shows
[OK!].
5) Remove the paper from the copyboard glass, and place it on the original
tray of the DADF.
6) Press [DF-WLVL2] on the touch panel to highlight.
7) Press [OK].
- The machine executes auto adjustment (duplex stream reading).
- When the adjustment ends normally, the machine indicates 'OK!' on the
screen.
8) If the monochromic adjustment fails, perform steps 2) to 7) again.
9) Place paper (of the type most often used by the user) on the copyboard
glass, and close the DADF.
10) Press [DF-WLVL3] to highlight.
11) Press [OK].
Automatic adjustment starts; if it ends successfully, the screen shows
[OK!].
12) Remove the paper from the copyboard glass, and place it on the original
tray of the DADF.
13) Press [DF-WLVL4] on the touch panel to highlight.
14) Press [OK].
- The machine executes auto adjustment (duplex stream reading).
- When the adjustment ends normally, the machine indicates 'OK!' on the
screen.
15) If the color adjustment fails, perform steps 9) to 14) again.
16) Press the Reset key twice to end service mode.
MEMO
This is a item of adjustment in which the white level of images made in
stream reading mode are matched with the white level of images made in
copyboard cover mode. If you omit this adjustment, the following will likely
occur:
- inappropriate reproduction of background density in images made in
stream reading mode
- wrong speck detection in stream reading mode
MEMO
This system incorporates a 4-line CCD sensor which is used for two types
of white level adjustments: a monochromic adjustment and a color
adjustment. "DF-WLVL1" and "DF-WLVL2" are for the monochromic
adjustment, and "DF-WLVL3" and "DF-WLVL4" are for the color
adjustment.