Sharp SF-2220 Service Manual page 102

(Example) When La=12mm and Lb=9mm, shift the paper exit side
mirror base B rail upward by 1.5mm.
•
When Lc > Ld, shift the mirror base B rail downward by half of
the difference of Lc – Ld.
•
When Lc < Ld, shift the mirror base B rail upward by half of
the difference of Lc – Ld.
(When moving the mirror base rail, hold the mirror base rail handle.)
2 Adjust according to procedure (1) so that La=Lb and Lc=Ld are
satisfied.
3 After completion of the adjustment, turn the mirror base drive
pulley manually to full scan mirror base A and mirror base B,
and check that the mirror bases are not brought into contact
with each other.
(Note) When the mirror bases are moved extremely, they
may be brought into contact. Carefully avoid it.
I. Center shift adjustment
a. This adjustment must be performed in the following cases:
•
The copy (100%) center is shifted from the original center
more than 2mm.
•
When any part of the lens rail or the lens unit is replaced.
<Adjustment procedure>
(1) make a test chart for center position adjustment. (Refer to the
figure below.)
Paper transport direction
(2) Set the test chart for the center position adjustment to the
document reference line, and make a normal (100%) copy with
an A4 or 11" × 8 ⁄
1
" paper.
2
(3) Check that the copied image line is at the center of the copy
paper.
2.0mm or less
(Copy A)
2.0mm or less
(Copy B)
(Paper feed direction)
(4) If the error of the copy image line is within the specified range
(0±2.0mm), the adjustment is not required. If not, perform the
following procedures.
Draw a line at the center
Copy paper
(A4 or 11" x 8½")
Copy image
Copy paper
Shift
fold
Copy paper
fold
Copy image
Shift
MC-Service
(5) Remove the document reference plate and the right upper side
cabinet, and remove the document table glass.
Document
reference plate
(6) Loosen the three fixing screws of the optical system unit and
slide the optical system unit to adjust the center position.
B
Optical system
unit
Loosen the
A
screws
(3pcs.)
Lens bearing side
(7) After adjustment, set the removed parts in the reversed se-
quence. make a copy of the test chart to check that the center
shift is within the specified range (0 ±2.0mm). If the center shift
is within the specified range, the adjustment is completed. If
not, repeat procedures (2) – (7) until it is within the specified
range.
J. Exposure balance adjustment
a. This adjustment is to provide uniform exposure, and must be
performed in the following cases:
•
When the reflector is replaced.
•
When the copy lamp is replaced.
•
When the exposure adjustment plate is replaced.
<Adjustment procedure>
(1) Set a half tone paper on the original table and make a half
tone copy at 100%.
(2) If the exposure of the half tone copy is uniform, the adjustment
is not required. If it is varied as shown below, perform the
following procedures.
Paper
discharge
direction
7 – 12
Document table glass
Right upper side cabinet
Original
center
(Original)
Copy
paper
center
2mm
or less
(Copy 1)
Move lens is the A direction
Copy
Lens
paper
body
center
side
2mm
(Copy 2)
or less
Move lens is the B direction
Exposure
insufficient
Half-tone copy