Sharp SF-1120 - Manual (Page 75)

[7] ADJUSTMENTS
1. Developing section
1-1. Developing doctor clearance adjustment
a. If the clearance between the developing doctor and the MAG
roller is improper, the following trouble may occur.
• Insufficient coy density
• Background copy
• Toner splash
(1) Remove the developing unit from the copier.
(2) Loosen four screws (A) which hold plate D fixed.
(3) Insert two clearance gauges of 0.6mm into the clearance be-
tween plate D and the MAG roller.
For insertion of the clearance gauges, refer to the
figure below.
(4) With two clearance gauges inserted, gently press plate D and
tighten four screws (A).
(5) Check that the clearances at two points 50 ∼ 80 mm from the
both ends of the developing doctor are within the specified
range (0.6
± 0.03mm).
When inserting the clearance gauges, be careful
not to scratch the plate D and the MAG roller.
When adjusting or checking, be careful not to allow
foreign materials (oil, etc.) to attach to the MAG
roller sleeve.
(6) After adjustment, apply screw lock to the four screws (A).
* For color developing unit, use the specified value of 0.7
±
0.03mm
for adjustment.
1-2.
Developing magnet roller main pole position
adjustment
a. If the MAG roller main pole position is improper, the following
troubles may occur.
• Insufficient copy density
• Toner splash
(1) Remove the developing unit from the copier.
(2) Tie a thread to a needle as shown below.
(3) Hold the thread and bring the needle close to the MAG roller.
(4) Mark the contact point of the thread on the MAG roller sleeve
surface.
0.6 ± 0.03mm
A A
50mm
30mm
50mm
30mm
Plate D
MAG roller
Clearance gauges
0.6mm
Marking
7 – 1