Sharp DM-1500, Service Manual

Page: 68 / 188

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 right-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 adjust-
ment 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 scan-
ning (front/rear) direction magnification ratio adjustment automat-
ically.
Manual adjustment: The adjustment is made by manual key opera-
tions. (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 dis-
assembled 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.)
2) Set the copy magnification ratio to 100%.
3) Make a copy on A4 or 8
1
⁄
2
″ ×
11
″
paper.
Change the height of the right side of the rail.
Change the height of the left side of the rail.
DM-1505
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