Sharp AL-1043, Service Manual

Page: 68 / 126

AL-1551 ADJUSTMENTS 9-4
e. Adjustment procedure
1) Set the test chart for image distortion adjustment on the document
glass, and make a normal copy on a paper of A4 or 8 1/2" x 11".
2) Check image distortion in the right and the left sides.
If both vertical lines are in parallel with each other, the right and left
distortion balance is proper. (However, there may be some
distortion.)
If all the four angles are right angles, there in no distortion and the
following procedures are not required.
3) If the right-left distortion balance is improper, loosen the fixing screw
of No.2/3 mirror unit rail to change and adjust the righ and left
balance of No.2/3 mirror unit rail.
Note: If the distortion in the lead edge side (when viewed in the paper
transport direction) is greater, change the height of the left rail of
No.2/3 mirror unit.
If the distortion in the rear edge side (when viewed in the paper
transport direction) is greater, change the height of the right rail of
No.2/3 mirror unit.
4) Make a copy to check the vertical image distortion.
If the four angles are right angles, the adjustment is completed.
B. Copy magnification ratio adjustment
The copy magnification ratio must be adjusted in the main scanning
direction and in the sub scanning direction. To adjust, use SIM 48-1.
(1) Outline
The main scanning (front/rear) direction magnification ratio adjustment is
made automatically or manually.
Automatic adjustment: The width of the reference line marked on the
shading correction plate is scanned to perform the main scanning (front/
rear) direction magnification ratio adjustment automatically.
Manual adjustment: The adjustment is made by manual key operations.
(In either of the automatic and manual adjustments, the zoom data
register set value is changed for adjustment.)
The magnification ratio in the sub scanning direction is adjusted by
changing the mirror base (scanner) scanning speed.
(2) Main scanning direction magnification ratio adjustment
a. Note
Before performing this adjustment, the following adjustments must have
been completed. If not, this adjustment cannot be performed properly.
• Image distortion adjustment
• The lens unit must be installed in the reference position.
b. Cases when the adjustment is required
1) When the lens and the mirror unit are disassembled or the part is
replaced.
2) When the copy lamp unit/No.2/3 mirror unit drive section is
disassembled or the part is replaced.
3) When the main PWB is replaced.
4) When the EEPROM in the main PWB is replaced.
5) When "U2" trouble occurs.
6) When the copy image distortion adjustment is performed.
c. Necessary tools
• Screwdriver (+)
• Scale
d. Adjustment procedure
1) Set the scale vertically on the document table. (Use a long scale for
precise adjustment.)
Greater distortion
Smaller distortion
Change the height
of the right side of the rail
.
Change the height
of the left side of the rail
.
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