Sharp AL-1611 Service Manual page 34

(4) Sub scanning direction (scanning direction)
distortion adjustment
When there is no skew copy in the mirror base scanning direction and
there is no horizontal error (right angle to the scanning direction), the
adjustment can be made by adjusting the No. 2/3 mirror base unit rail
height.
Before performing this adjustment, be sure to perform the horizontal
image distortion adjustment 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 or No. 2/3 mirror unit is replaced.
• When the mirror unit rail is replaced or moved.
• When a following copy is made.
1) Making of a test sheet
Make test sheet by drawing parallel lines at 10mm from the both
ends of A3 (11" x 17") white paper as shown below. (These lines
must be correctly parallel to each other.)
10mm
10mm
2) Make a normal (100%) copy of the test sheet on A3 (11" x 17")
paper. (Fit the paper edge with the glass holding plate edge.)
3) Measure the distances (La, Lb, Lc, Ld) at the four corners as shown
below.
La
Lb
When La = Lb and Lc = Ld, no need to perform the procedures 4)
and 5).
4) Move the mirror base F rail position up and down (in the arrow
Note: If the rear side rail is used for the adjustment, the scanning posi-
10mm
10mm
<Adjustment specification>
La = Lb, Lc = Ld
5) After completion of adjustment, manually turn the mirror base drive
Lc
Ld
AL-1611/AL-1622 ADJUSTMENTS
7 – 7
direction) to adjust.
tion of the white balance sheet is shifted and "E7-04" may occur
only when scanning with the SPF. Therefore it is advisable to
use the front side rail for the adjustment.
• When La > Lb
Shift the mirror base B rail upward by the half of the difference of La
– Lb.
• When La < Lb
Shift the mirror base B rail downward by the half of the difference of
Lb – La.
Example: When La = 12mm and Lb = 9mm,, shift the mirror base
B rail upward by 1.5mm.
• When Lc > Ld
Shift the mirror base B rail downward by the half of the difference of
Lc – Ld.
• When Lc < Ld
Shift the mirror base B rail downward by the half of the difference of
Ld – Lc.
When moving the mirror base rail, hold the mirror base rail with your
hand.
pulley, scan the mirror base A and mirror base B fully, and check
that the mirror bases are not in contact with each other.
If the mirror base rail is moved extremely, the mirror base may be in
contact with the frame or the original glass. Be careful to avoid this.