MX-6240N, MX-7040N (serv.man24). Section 5 Adjustments and Settings - Updated November 2012 - Sharp Copying Equipment Service Manual (repair manual). Page 17

MX-7040N  ADJUSTMENTS AND SETTINGS  5 – 17

5)

Open the front cover, and turn the four LSU image skew
adjustment screws in the same direction by the same degree.

When C is greater than D in the method 1 or there is some
skew in the direction A in the method 2, turn the screw clock-
wise.

When C is smaller than D in the method 1 or there is some
skew in the direction B in the method 2, turn the screw coun-
terclockwise.

In case of the method 1, 0.8mm/about 1.5 rotations

In case of the method 2, 0.5mm/about 1.5 rotations

Repeat the procedures 2) to 6).

After completion of the black image skew adjustment, go to the
procedure 7).

6)

Perform the same procedures as 1) and 2).

7)

Check the printed color image for any skew.

If the difference between the shift amounts on the F and R
sides is within 

 1 scale of the fine adjustment check scale,

there is no need to perform the adjustment.

Measure the skew amount from the print patterns on the front
and rear sides of each color.

In each Y/M/C color print pattern printed separately in the F
side and in the R side, note the same print color pattern and
check to confirm that the F side and the R side are in the same
condition.

Check the sub scan rough adjustment color image shift check
section on the R side and the F side of each color, use the cen-
ter position of the black scale as the reference, and check the
balance in shifts of the color image line positions in the positive
and the negative directions. The balance in the R side must be
the same as that in the F side.

Check the square frames on the R side and the F side of each
color. (Normally five sections of high density can be seen.)
Check the sub scanning direction position of the center area of
high density (one of the above five sections). These must be
on the same position on the R side and the F side.

In this case, use the sub scan direction color image shift check
scale (fine adjustment) as the reference.

Visually check the color density and make the darkest section
as the center, and use it as the read value of the shift amount.

Check that the difference in the center position of the dark den-
sity section is within 

1 step.

The positional relations of the front and the rear frame of the
print color patterns of a same color are compared. There is no
need that all the colors are in the same state. Compare only
the positional relations of color patterns of a same color.

If the above condition is not satisfied, perform the following
procedure.

8)

Turn the LSU skew adjustment screw of the adjustment target
color to adjust.

When the F side is skewed to the right side for R side: Turn the
screw clockwise.

When the F side is skewed to the left side for the R side: Turn
the screw counterclockwise.

Skew of difference by one step between F and R sides (Differ-
ence by one scale of the fine adjustment check scale) / Turn
for about 2 clicks.

Repeat the procedures 7) to 8) until a satisfactory result is
obtained.

R side

F side

A-sub

B-sub

A-main

B-main

Color image shift
check section
(Rough adjustment)

C (Image shift fine adjustment
reference frame)

Color image shift check
scale (Fine adjustment)

A-main: Main scan rough adjustment pattern
A-sub: Sub scan rough adjustment pattern
B-main: Main scan fine adjustment scale
B-sub: Sub scan fine adjustment scale
C: Main scan sub scan fine adjustment pattern