Canon NP6621, Service Handbook, Page: 15 / 146

2–1
STANDARDS AND ADJUSTMENTS
CHAPTER 2 STANDARDS AND ADJUSTMENTS
A. Mechanical
1 Adjusting the Image Leading
Edge Margin ([3], No. 305;
registration ON timing)
Select service mode ([3] No. 305; leading edge
margin adjustment). Make adjustments so that the
image position is as indicated in Figure 2-200 when
the Test Chart is copied in DIRECT.
2 Adjusting the Leading Edge Non-
Image Width ([3], No. 306; blank
shutter ON timing)
Select service mode ([3] No. 306; leading edge
non-image width), and make adjustments so that
the leading edge non-image width is as indicated in
Figure 2-201 when the Test Sheet is copied in
DIRECT.
The machine adjusts the leading edge non-
image width taking advantage of the timing at which
the blanking shutter closes.
You must make this adjustment whenever you
have replaced the blanking shutter solenoid or the
blank exposure assembly.
Leading Edge Non-Image Width
2
Figure 2-200
Making Adjustments
1) Choose service mode [3], and select No. 305
using the numeric keypad.
• The copy count display flashes ‘No. 305’.
2) Press the Start key.
• The display flashes the present value.
• If the value is negative, ‘%’ is flashed.
To enter a negative value, press the % key,
and then enter the value using the numeric
keypad.
4) Press the AE key.
• The value is stored and the display remains
ON.
• Copying starts when the start key is pressed.
5) To enter a value once again, repeat steps 1)
and 4).
6) Press the Clear key to return to item selection.
The following is the relationship between the
settings and the image positions:
• For each ‘1’, the image position changes by
about 0.27 mm.
• For a ‘+’, the image position advances.
Figure 2-201
Reference:
In enlargement/reduction mode, 6 mm or less.
Making Adjustments
1) Select service mode ([3] No. 306).
• The copy count display flashes ‘No. 306’.
2) Press the Start key.
3) Change the setting using the numeric keypad.
• The display flashes the present value.
• If the value is negative, ‘%’ is flashed.
To enter a negative value, press the % key,
and then enter the value using the numeric
keypad.
4) Press the AE key.
• The value is stored and the display remains
ON.
• Copying starts when the start key is pressed.
5) To enter a value once again, repeat steps 1) and
2).
2.5±1.5mm
2.5±1.5mm