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MX-C301  ADJUSTMENTS  5 – 15

RV: REAR VOID AREA

FV: FRONT VOID AREA

RV + FV 

RV = 2.0 +/- 2.0mm

FV = 2.0 +/- 2.0mm

If the above requirement is not met, do the following steps.

6)

Change the adjustment value.

Enter the adjustment value and press the [OK] key or the
[EXECUTE] key.

When [EXECUTE] key is pressed, the adjustment pattern is
printed.

When the adjustment value is increased, the adjustment pat-
tern is shifted to the front frame side. When it is decreased, the
adjustment pattern is shifted to the rear frame side.

When the set value is changed by 1, the shift distance is
changed by about 0.1mm.

Repeat procedures 3) - 6) until the conditions of procedure 5)
are satisfied.

In case a satisfactory result cannot be obtained by repeating
the above procedures, perform the following procedure.

7)

Loosen the paper feed tray off-center adjustment screws (2
pcs.) at the center section of the lift plate of the paper feed tray,
and change the gear unit position in the front/rear frame direc-
tion. Repeat the adjustment procedures from 4).

Normally if the adjustment is executed by ADJ 4 (automatic adjust-
ment), there is no need to execute this adjustment.

Only when the manual adjustment is required, execute this adjust-
ment.

In other words, this manual adjustment is executed when a satis-
factory result is not obtained from the automatic adjustment (ADJ
4).

 

This adjustment must be performed in the following cases:

* When the color shift occurs.

* When the LSU is replaced.

* When the LSU is removed from the main unit.

* When the unit is installed or when the installing place is changed.

* When maintenance work is performed. (Replacement of the

OPC drum, the OPC cartridge, the transfer unit, the transfer belt,
etc.)

* When [ADJ 4A] Print engine image magnification ratio adjust-

ment (BK) (main scanning direction) is performed.

* U2 trouble has occurred.

* When the MFP PWB is replaced.

* When the color phase is not proper even after execution of the

color balance adjustment.

* When the OPC drum drive section is disassembled.

* When the primary transfer unit is replaced. (when it is removed

from the machine)

* When the developing unit or the OPC drum unit is removed from

the machine.

26
MM MM

&6
MM MM

MX-C301  ADJUSTMENTS  5 – 16

 

This adjustment performs the print engine image distortion adjust-
ment, the OPC drum phase adjustment, and the color registration
adjustment simultaneously.

1)

Enter SIM50-22 mode.

2)

Press [EXECUTE] key.

The image registration automatic adjustment is started. (It
takes about 15 sec to complete the adjustment.)

3)

When the adjustment is completed, the value of the adjust-
ment result is displayed.

The current skew level for each color is displayed on the
SKEW display section.

4)

Write down the displayed skew level. 
When  "SKEW_*" values are in the following ranges, the
adjustment needs not to be done.  
 * To make "SKEW_*" values in the following ranges, turn the
LSU skew adjustment screws clockwise direction (a) or coun-
terclockwise direction (b). 
SKEW_C : +/-30, SKEW_M : +/-40, SKEW_Y : +/-20

MAIN F

-

REG_M_F 
(VALUE)

Registration 
adjustment 
correction 
amount main 
scanning 
direction F

1.0 - 199.0 (+/
-0.1)

( )

REG_M_F (DIF)

Registration 
value correction 
amount from the 
previous one, 
main scanning F

-199.0 - 199.0 
(+/-0.1)

MAIN R

-

REG_M_R 
(VALUE)

Registration 
adjustment 
correction value, 
main scanning 
direction R

1.0 - 199.0 (+/
-0.1)

( )

REG_M_R 
(DIF)

Registration 
value correction 
amount from the 
previous one, 
main scanning R

-199.0 - 199.0 
(+/-0.1)

SUB

-

REG_SUB 
(VALUE)

Registration 
adjustment 
correction value, 
sub scanning 
direction

1.0 - 199.0 (+/
-0.1)

( )

REG_SUB (DIF)

Registration 
value correction 
amount from the 
previous one, sub 
scanning

-199.0 - 199.0 
(+/-0.1)

SKEW

CMY

SKEW_CLC

SKEW 
adjustment 
rotating direction 
and the number 
of clicks (CMY)

L99.9 - R99.9 
(+/-0.1)

ALL_
ROTA
TE

SKEW 
adjustment 
rotating direction 
and the number 
of clicks (K)

PHASE

PHASE_ADJ

Phase 
adjustment value 
(1: Value of this 
time, 2: Value of 
the previous time)
Angle step 0 
degrees (1) -> 45 
degrees (2) -> 90 
degrees (3) -> 
135 degrees (4) -
> 180 degrees (5) 
-> 225 degrees 
(6) -> 270 
degrees (7) -> 
315 degrees (8)

1 - 8 (+/-1)

MX-C301  ADJUSTMENTS  5 – 17

5)

If there are several skewed areas on the test printing result,
turn all the LSU skew adjustment screws shown in the figure
to adjust, and perform the procedures 2) to 4).

Repeat the procedures 2) to 5) until the printing result has no
skew area.

 If the printing result has no skew area, the adjustment is fin-
ished.  

For the adjustment, remove the paper tray, and turn the skew
adjustment screw from the bottom of the main unit.

When the adjustment is made by turning the LSU skew adjustment
screw of K, the states of C, M and Y (SKEW) are changed. Execute
SIM50-22 to check to confirm that C, M, and Y (SKEW) are OK.

The adjustment result can be checked by the following manual
adjustment mode.

* ADJ  5B

Image skew adjustment (Manual adjustment) (SIM50-20)

* ADJ  5C

Color registration offset adjustment (SIM50-20)

When the color registration is greatly shifted due to replacement of
the LSU, etc, if SIM50-22 is used to perform the color registration
automatic adjustment, an error may occur.

In this case, the adjustment may be properly executed by setting
the adjustment items A - I of SIM50-20 to "100" and executing the
automatic adjustment again.

If color shift in an actual print image differs in the center, the front
side, and the rear side, the color shift offset adjustment can
improve it. (Refer to ADJ 5C.)

Normally there is a difference in color shift in several dots. Perform
the adjustment only when the adjustment is required.

 

If a more accurate adjustment than the automatic adjustment ADJ
5A is required, use this method of adjustment.

This adjustment is made by changing the parallelism of the LSU
unit scan laser beams for the OPC drum.

1)

Enter the SIM 50-20 or 64-01 mode.

2)

Select the paper feed tray with A4(11"x8.5") paper in it, and
press [START] key.

3)

The image skew (image registration) adjustment pattern is
printed.

4)

Check the printed black image for any skew.

Use the four cross points printed in black to measure the
squareness.

There are following two methods of checking the black image
for any skew (right angle).

Measure the distances between opposing corners of the rect-
angle print pattern, and compare the two distances to check
the squareness.

Check the squareness of the vertical and horizontal sides of
the rectangle print pattern by using A4(11"x8.5") paper sides.

In the case of Method 2, the right angle of paper to be used
may not be exact. Be sure to check the right angle of paper to
be used in advance.

Measure the length of the diagonal lines of the rectangle print
pattern.

Calculate the difference between the measured lengths C and
D of the diagonal lines.

Check to insure that the difference between C and D is in the
following range.

C - D = 0.8mm

If the difference between C and D is in the above range, there
is no need to adjust.

Fit the side of A4(11"x8.5") paper to the long side of the rectan-
gle print pattern.

Measure the slant (skew) of the vertical side for the horizontal
side of paper as shown in the figure.

If the above distance is 0.5mm or less, there is no need to
adjust.

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

C

M

Y

B

A

MX-C301  ADJUSTMENTS  5 – 18

5)

Open the front cover, remove the waste toner box, and turn the
four LSU image skew adjustment screws in the same direction
by the same amount. 

For the adjustment, remove the front cover and the waste
toner box, and turn the skew adjustment screw.

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 look identical.

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.

C

M

Y

B

A

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