Sharp SF-1120 - Manual (Page 88)

(4) Measure the distance between the copy paper lead edge and
the copy image lead edge in each copy. Obtain RRC-A and
RRC-B values from the following formulas.
If the RRC-A preset value is not proper, the lead edge
position varies in each magnification ratio. The RRC-B is to
adjust the RRC ON timing for fitting the drum image lead
edge and the transfer paper lead edge.
• La: Led edge shift at 200% (mm)
• L2: Lead edge shift at 1005 (mm)
• RRC-A = 6.151 × (L1 – L2)
• RRC-B = 15.385
×
L2 – 7.692
×
L1
(5) Enter the RRC-A and RRC-B values obtained from the above
formulas with the 10 digit key pad in the same manner as
procedure (3).
(6) Make copies at 200%, 100%, and 50%, and check variations in
the magnification ratios. (About 1.0mm)
If there is a considerable variation, repeat from procedure (3).
(7) Make a normal copy and check that the lead edge image loss
is within the range of 0
∼ 4mm. If the image loss is outside the
above range, change the RRC-B value and adjust again until
the image loss is within the above range.
Note: The above image loss range is effective only for
simulation 50-01, and is not the final one.
(8) Put a scale and an A3 (11" × 17") white paper on the original
table as shown below.
(9) Press the zoom key to display "C" in the lowest digit of the
magnification ratio display. (Void amount adjustment mode)
(10) Make a copy and enter the normal copy lead edge void area
adjustment set value so that the black background edge
comes to the scale 1 – 3mm of the copy image scale.
→ →
PSW
With the above key operation, a copy is made and the adjust-
ment value is inputted. When the adjustment value is changed
by 1, the void area is changed by about 0.13mm. The greater
the adjustment value is, the greater the void amount is.
L2
50 20 10 30 40 60 70
10 20 30
L1
End of scale image End of scale image
Full-size(100%) copy Enlarged(200%) copy
10 20 30 40 50 60 70
Image loss
0~4mm Full-size(100%) copy
10 20 30 40 50 60 70 80 90 50 100 110 12 0130 140
Scale
50mm
A3(11" x 17") Blank paper
10 20 30 40 50
End void area
1~3mm
Scale image
Solid edge
Paper end
Full-size(100%) copy
7 – 14