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AR-M550/M620  SETTING AND ADJUSTMENTS  7 - 9

Repeat steps 6 to 12 until an acceptable result is obtained.

This adjustment is needed in the following situations: 

• The scanner (reading) section has been disassembled. 

• Scanned images are distorted. 

1) Loosen the fixing screws for Scanner Unit A and scanner drive wire

to release the scanner unit from the drive wire.

2) Manually turn the scanner drive pulley, and move Scanner Unit B

until contact with the two stoppers on the CCD mounting plate. 

If Scanner Unit B makes contact with the two stoppers on the CCD
mounting plate simultaneously, the parallelism of Scanner Unit B is
proper.

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

3) Loosen the pulley angle fixing screw on either the front or rear

frame side of Scanner Unit B.

4) Adjust the pulley angle position on Scanner Unit B so that the

scanner unit makes contact with both of the two stoppers on the
CCD mounting plate at the same time.

5) Fix the pulley angle on Scanner Unit B.

If the above steps fail to provide an acceptable result, then do the fol-
lowing steps. 

6) Loosen the fixing screw of the scanner unit drive pulley that is not

in contact.

7) Manually turning the scanner unit drive pulley, move Scanner Unit

B until it comes into contact with the two stoppers on the CCD
mounting plate.

a

b

Scanner Unit B

Winding pulley

AR-M550/M620  SETTING AND ADJUSTMENTS  7 - 10

8) Without moving the scanner unit drive shaft, manually turn the

scanner unit drive pulley so that Scanner Unit B makes contact
with both of the two stoppers on the CCD mounting plate at the
same time.  (Change the positional relationship between the scan-
ner unit drive pulley and the drive shaft.)

9) With Scanner Unit B in contact with both of the two stoppers on the

CCD mounting plate at the same time, align the end face of Scan-
ner Unit A with the right-hand side end face of the frame, and fix
Scanner Unit A with the screws.

This adjustment is needed in the following situations: 

• The scanner (reading) section has been disassembled. 

• Scanned images are distorted.

1) Make a test chart on A3 (11" x 17") paper as shown below. (Draw a

rectangular with four right angles.)

2) Set the test chart made in step 1 on the document table (about 30

mm in front of the document standard setting position), and make a
copy on A3 (11" x 7") paper with the SPF unit open.

3) Check for distortions in the sub scanning direction.

If La = Lb, there is no distortion.

L

L

L

L

L = 10mm

30mm

AR-M550/M620  SETTING AND ADJUSTMENTS  7 - 11

If there is some distortion in the sub scanning direction, do the follow-
ing steps.

4) Loosen either of two fixing screws of the scanner unit drive pulley.

(Either one on the front or the rear side will do.)

5) With the scanner unit drive shaft kept stationary, manually turn the

scanner unit drive pulley to change the parallelism of Scanner
Units A and B. (Change the positional relationship between the
scanner unit drive pulley and the drive shaft.)

6) Tighten the scanner unit drive pulley fixing screw.

Repeat steps 2 to 6 until an acceptable result is obtained. 

If the above steps fail to eliminate distortions in the sub scanning direc-
tion, do the steps described in "ADJ 6E: Adjust scanned image distor-
tions in the main scanning direction - 2."

This adjustment is needed in the following situations:

• The scanner (reading) section has been disassembled.

• Scanned images are distorted.

1) Make a test chart on A3 (11" x 17") paper as shown below. (Draw a

rectangular with four right angles.)

2) Set the test chart made in step 1 on the document table, and make

a copy on A3 (11" x 17") paper.

3) Check for distortions in the main scanning direction.

If the four angles of the rectangle on the copy are right angles,
there is no distortion and therefore  no further steps are needed.

If there is some distortion in the main scanning direction, do the follow-
ing steps.

4) Check the difference (distortion balance) between left-hand and

right-hand side images distortions.

If Lc = Ld, the distortion on the left is equal to that on the right. (The
distortions are balanced.) 

If the above requirement is satisfied, then do the steps described in
"ADJ 3E: Adjust scanned image distortions in the main scanning direc-
tion - 2."

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

5) Change the height balance of the front frame side scanner rail.

• If the paper leading edge is more distorted than the paper trailing

edge, then raise the scanner rail right side. 

• If the leading edge is less distorted than the paper trailing edge, then

lower the scanner rail right side.

6) Set the test chart made in step 1 on the document table, and make

a copy on A3 (11" x 17") paper.

7) Check the image distortion balance in the main scanning direction.

Repeat steps 5 to 7 until the difference in size of image distortion (dis-
tortion balance) in the image scanning direction is equal.

L

L

L

L

L = 10mm

Lc

Ld

Lc

Ld

Copy A

Copy B

There is no difference 

between the distortion on 

the right and that on the left.

Lc = Ld

There is some difference 

between the distortion on 

the right and that on the left.

Lc 

≠

 Ld

AR-M550/M620  SETTING AND ADJUSTMENTS  7 - 12

This adjustment is needed in the following situations: 

• The scanner (reading) section has been disassembled. 

• Scanned images are distorted. 

1) Make a test chart on A3 (11" x 17") paper as shown below. (Draw a

rectangular with four right angles.)

2) Set the test chart made in step 1 on the document table, and make

a copy on A3 (11" x 17") paper.

3) Check for distortions in the main scanning direction.

If the four angles of the rectangle on the copy are right angles,
there is no distortion and therefore  no further steps are needed.

If there is some distortion in the main scanning direction, do the follow-
ing steps. These steps assume that there is no or little difference in dis-
tortion between the paper's leading and trailing edges.

If there is some difference in distortion between the paper's leading
and trailing edges, these steps should be preceded by the adjustment
steps described in "ADJ 3D: Adjust scanned image distortions in the
main scanning direction - 1", intended to provide almost the same level
of distortion on the leading and trailing edges.

4) Remove the document table glass, and make adjustments by turn-

ing the main scanning direction image distortion adjusting screw.

• If the rear frame side image is shifted toward the paper's leading

edge, then turn the adjusting screw clockwise. 

• If the front frame side image is shifted toward the paper's leading

edge, then turn the adjusting screw counterclockwise. 

Repeat steps 2 to 4 until an acceptable result is obtained.

It changes approx. 0.5mm by 90 degrees rotation.

This adjustment is needed in the following situations: 

• The SPF section has been disassembled. 

• The SPF unit has been replaced. 

1) Create two check sheets for SPF levelness adjustment by cutting

copy paper as illustrated below: 

2) Insert each of the two check sheets in between the CIS guide boss

and the glass for SPF mode on each of the front and rear frame
sides, and then close the SPF unit.

L

L

L

L

L = 10mm

A4 size