MX-6240N, MX-7040N (serv.man24). Section 5 Adjustments and Settings - Updated November 2012 - Sharp Copying Equipment Service Manual (repair manual). Page 18

MX-7040N  ADJUSTMENTS AND SETTINGS  5 – 18

 

This adjustment is used to set the offset value for the automatic
color registration adjustment (ADJ4A).

If there is any difference in color phase at the center and the four
corners of an actual print image, this adjustment may improve it.
Especially when there is any color shift at the center area, this
adjustment may improve it effectively.

This adjustment cannot eliminate color shifts in all the areas, but
average the overall color shifts.

After the automatic adjustment, use this color registration offset
adjustment to correct color shift partially, performing the adjustment
efficiently.

NOTE:

Before execution of this adjustment, check to confirm that the fol-
lowing adjustment has been properly made.

* ADJ4A or ADJ4B image skew adjustment (LSU unit)

There are following two kinds of registration adjustment values.

• Base registration adjustment value: XXX(FRONT)/XXX(REAR)

They are manual adjustment values and automatic adjustment
values, and reflected when the automatic registration adjustment
is executed. It varies for every operation of the automatic regis-
tration adjustment.

• Offset adjustment values: OFFSETXXF/OFFSETXXR

They are the offset adjustment values added to the above base
registration adjustment values, and are not changed unless
SIM50-20 is executed to change.

1)

Enter SIM50-20 mode.

2)

Select the paper feed tray with A3 (11" x 17") paper in it.

3)

Press [EXECUTE] key.

The color image registration check pattern is printed.

4)

Check the color image registration.

There are 6 color image registration patterns in total; two on
each of the F side, the R side, and the center. Check all the
patterns to confirm that they are within the specified range.
Also check to confirm that there is not much shift in each color
image registration check pattern.

NOTE: There are two kinds of adjustment: one in the main scan-

ning direction and the other in the sub scanning direction.
The vertical direction in the above figure is that in the main
scanning direction, and the horizontal direction is that in the
sub scanning direction.

There are also two kinds of adjustments: the rough adjust-
ment and the fine adjustment. Perform the rough adjust-
ment then perform the fine adjustment deliberately.

For the main scan direction image registration, the offset on the F
side, the R side, and at the center is independently adjusted.

If there is a difference in the sub scanning direction image registra-
tion between the F and R sides, perform the skew adjustment (ADJ
5A).

Check the print patterns of the rough adjustment and the fine
adjustment of 18 check patterns.

Visually check the color image registration check section, use the
center position of the black scale as the reference, and check the
shift balance in the positive and negative directions at the color
image line position.

Use the center position of the black scale as the reference, and
check that the color image line is symmetrical in the positive side
and the negative side.

If shift is in the arrow mark X1 and Y1, increase the adjustment
value. If shift is in the arrow mark X2 and Y2, decrease the adjust-
ment value.

The reference arrow on the check pattern faces the positive direc-
tion.

1 scale/10 (When the set value is changed by 10, shift is made by 1
scale.)

Check to confirm that the darkest spot (one of 5 spots seen nor-
mally) is within the center area of the image registration adjustment
reference frame in the square frame.

At that time, use the color image registration check scale (fine
adjustment) as the reference.

Visually check and consider the darkest section of color density as
the center, and measure the shift from it.

Check to confirm that the center of the dark density section is within
 1 step.
(If the fine adjustment print pattern is in the range of 0 

 1 for the

fine adjustment reference pattern scale, there is no need to adjust.)

If shift is in the arrow mark X1 and Y1, increase the adjustment
value. If shift is in the arrow mark X2 and Y2, decrease the adjust-
ment value.

Rear pattern

Center pattern

Front pattern

Reference arrow mark

A-sub

B-sub

B-main

A-main

X1

X2

Y2

Y1

Color image shift
check section
(Rough 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

Color image shift check
scale (Fine adjustment)

C (Image shift fine adjustment
reference frame)