Sharp AR-280 Service Manual page 61

4) Loosen the fixing screw of the front or the rear frame mirror base
drive pulley.
·
If La < Lb, turn the rear frame mirror base drive pulley in
direction B. (Do not move the mirror base drive pulley shaft.)
·
If La > Lb, turn the rear frame mirror base drive pulley in
direction A. (Do not move the mirror base drive pulley shaft.)
Front side
5) Tighten the fixing screw of the mirror base drive pulley.
6) Perform procedures 1) through 3).
7) If La is not equal to Lb, perform procedures 4) and 5).
If La = Lb, the adjustment is completed.
Repeat procedures 1) through 6) until La = Lb.
(4) Horizontal (main scanning direction) distorion
adjustment [Lower rail height adjustment]
When there is no distortion in the direction of mirror base scanning
and there is sub scanning direction distortion, it can be adjusted by
changing the No. 2/3 mirror base unit rail height.
·
Before this adjustment, perform the horizontal image distortion ad-
justment in the laser scanner section.
This adjustment must be performed in the following cases:
·
When the mirror base wire is replaced.
·
When the copy lamp unit and no. 2/3 mirror unit are replaced.
·
When the mirror unit rail is replaced and moved.
·
When a copy shown below is made.
Original
1) Make an original for the adjustment.
Draw parallel lines at 10mm from both sides of an A3 white paper.
Parallel line
10mm
10mm
Rear side
A
B
Copy
Parallel line
10mm
10mm
White paper
illust: AR-280
2) Make a copy of the adjustment original on an A3 white paper at
the normal magnification ratio.
(Fit the paper edge and the glass holding plate edge.)
3) Measure the distances between the lines and the corners (4 posi-
tions of La, Lb, Lc, Ld).
La
Paper exit
direction
Lb
When La = Lb and Lc = Ld, no need to adjust.
When La = Lb = Lc = Ld, there is no need for adjustment.
4) Move the mirror base B rail position up and down (in the arrow
direction) to adjust.
·
When La > Lb, move the mirror base B rail on the paper
exit side upward by the half of the difference of La – Lb.
·
When La < Lb, move the mirror base B rail on the paper
exit side downward by the half of the difference of Lb - La.
Example: When La = 12mm and Lb = 9mm, move the
mirror base B rail on the paper exit side 1.5mm
upward.
·
When Lc > Ld, move the mirror base B on the paper feed
side downward.
·
When Lc < Ld, move the mirror base B on the paper feed
side upward.
* When moving the mirror base rail, hold the mirror base rail
handle.
5) Adjust so that La = Lb and Lc = Ld.
6) After completion of the adjustment, manually turn the mirror base
drive pulley to make full scanning of mirror base A and mirror base
B and check that they do not make contact.
* If the mirror base rail is moved extremely, the mirror base may
be brought into contact. Be careful of that.
6 – 11
Lc
Ld
illust: AR-280
7/13/2000