Sharp SF-2050 Service Manual page 81

(10) Exposure balance adjustment
Make a half tone copy at normal ratio (100%), and adjust exposure
adjustment plates a, b, and c in the directions of arrows A and B.
Moving the adjustment plate in the direction of arrow A make the copy
darker, and moving in the direction of arrow B makes the copy lighter.
(Example) When a copy as shown at right was made, move the
exposure adjustment plate in the direction of arrow B to
take balance of exposure.
Since the center section slit is fixed, the adjustment must be per-
formed based on the exposure level at the center as the reference.
(11) Copy lead edge adjustment
The copy led edge adjustment is performed with simulation 50-01 and
50-02.
(Normal copy) Image loss: 0 ∼ 4mm
1 ∼ 3mm
Void area:
<Setting with simulation 50-01>
LCD DISPLAY COPY QUANTITY DISPLAY
* * *
INPUT_A (0~99) : Distance from MHP to image lead edge (1 count = 0.47mm)
SCROLL KEY
* * *
: Time data from image lead edge to PSC ON (1 count = 0.5ms)
INPUT_B (0~99)
SCROLL KEY
* * *
:
INPUT_C (1~20)
SCROLL KEY
* * *
: Lead edge void amount data(1 count = 0.47mm)
INPUT_D (0~20)
Adjustment procedure
1
Put a scale on the original table.
C → ë → 0 → ë → 5 → 0 → PSW → 1 → PSW
2
When the above key operation of simulation 50-01 is executed,
the machine starts warming up.
The ready lamp is lighted and the previously set value (RRC-A
value: distance from MHP to the image lead edge (1 ∼ 99) is
displayed.)
3
Set values A and B to zero, and make copies at 100% and 200%.
0 → 0 → P → → → 0 → PSW (A copy at 100% is
•
made.)
Enlargement key → (Lens shift, ready) → PSW (A copy at
•
200% is made.)
ON
ON
ON
8 – 15
A A A
B B B
Exposure adjustment plate c
Exposure adjustment plate b
Exposure adjustment plate a
Paper discharge
direction
Half-tone copy
SIMULATION NO. 50
INPUT (1~4)
1. LEAD EDGE, LEAD EDGE VOID AREA ADJUSTMENT.
2. LEAD EDGE ADJUSTMENT. (INPUT)
3. LEAD EDGE/VOID ADJUSTMENT. (INPUT)
4. VOID ADJUSTMENT. (INPUT)
Scale
Fix.
A A A
B B B
Exposure adjustment plate d
Exposure
insufficient