Sharp AR-151 Service Manual page 78

AR-F152
[8] ADJUSTMENT
1. Optical section
A. Image distortion adjustment
There are following two types of image distortion.
Horizontal image distortion
Vertical image distortion
In this machine, the image distortion is adjusted by changing the paral-
lelism of mirrors (copy lamp unit, No. 2/3 mirror unit).
(1) Horizontal image distortion adjustment
a. Summary
Parallelism of mirrors can be made by installing the copy lamp unit
and No. 2/3 mirror unit to the reference position. However, it must
be checked by making a copy, and must be adjusted if necessary.
b. Cases when the adjustment is required
1) When the copy lamp unit and No.2/3 mirror unit are disas-
sembled or their part is replaced.
2) When the copy lamp unit and No.2/3 mirror unit drive section is
disassembled or its part is replaced.
3) When the copy image is distorted as shown below:
Document Copy A
c. Necessary tools
Screwdriver (+)
Hex wrench
Scale
Test chart for distortion adjustment (Make a chart shown below
by yourself.)
Draw a rectangle on a paper (B4 or 8 1/2" × 14") as shown
below.
Be sure to make four right angles.
L
L
L
Copy B
L
L = 10mm
8 – 1
d. Adjustment procedure
1) Remove the right cabinet (manual paper feed unit), the docu-
ment reference plate.
2) Remove the document glass.
3)
3) Loosen the fixing screw of the copy lamp unit wire.
Fixing Screws
4) Manually turn the copy lamp unit/No.2/3 mirror unit drive gear to
bring No.2/3 mirror unit into contact with No.2/3 mirror unit
positioning plate. When No.2/3 mirror unit makes contact with
No.2/3 mirror unit positioning plate in the Freat and rear frame
side simultaneously, the mechanical parallelism of No.2/3 mirror
unit is proper.
If one side of No.2/3 mirror unit makes contact with No.2/3 mir-
ror unit positioning plate and the other side does not, the paral-
lelism is improper.
If the parallelism is improper, perform the procedure of step 5).
1)
2)