Sharp AR-5127, Service Manual

Page: 25 / 94

AR-5127 ADJUSTMENTS 7 - 6
2) Open the original cover and make a normal (100%) copy.
3) Measure the width of the black background at the lead edge and at
the rear edge.
If the width (La) of the black background at the lead edge is equal
that (Lb) at the rear edge, there is no need to execute the following
procedures of 4) – 7).
4) Loosen the mirror base drive pulley fixing screw on the front frame
side or on the rear frame side.
5) Tighten the fixing screw of the mirror base drive pulley.
<Adjustment specification>
La = Lb
6) Execute the main scanning direction (FR) distortion balance
adjustment previously described in 2) again.
(9) Main scanning direction (FR direction) distortion
balance adjustment (Rail height 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 and no. 2/3 mirror unit are replaced.
• When the mirror unit rail is replaced and moved.
• When a following copy is made.
1) Make an original for the adjustment.
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.)
2) Make a normal (100%) copy of the test sheet on A3 (11" x 17")
paper. (Fit the paper edge and the glass holding plate edge.)
3) Measure the distances (La, Lb, Lc, Ld) at the four corners as
shown below.
When La = Lb and Lc = Ld, no need to perform the procedures 4)
and 5).
4) Move the mirror base B rail position up and down (in the arrow
direction) to adjust.
• When La < Lb
Turn the mirror base drive pulley on the front frame side in the
arrow direction A. (Do not move the mirror base drive pulley shaft.)
• When La > Lb
Turn the mirror base drive pulley on the rear frame side in the
arrow direction A. (Do not move the mirror base drive pulley shaft.)
Paper exit direction
La: Lead edge black background width
Lb: Rear edge black background width
A
B
Rear side
Front side
Original Copy A Copy B
10mm
10mm
10mm
10mm
Parallel line Parallel line
White paper
La
Lb Ld
Lc
Paper exit
direction