Sharp AR-280 Service Manual page 65

3) Place the scale on the document table as shown below.
Note that the scale must be placed in parallel to the scanning
direction and that the scale lead edge is in close contact with the
document guide plate.
Scale
10 20 30 40 50 60 70 80 90 50 100 110 120 130 140
4) Enter the SIM 50-2 mode.
5) Set the image loss and DEN-A set values to "0."
6) Set all the values of L1, L2, and L3 to "0."
7) Make a copy at 400%. (Document table mode)
8) Measure dimensions X and Y of the copied scale image.
X: Distance between the copy image lead edge and the scale
of 10mm
Y: Distance between the paper lead edge and the copy image
lead edge
X
Paper lead
edge
10
Y
9) Set the document as in procedure 1) and 2) on the SPF, and
make a copy at 200% in the SPF mode.
10) Measure the dimension L3 of the copied scale image.
Z: Distance between the copy image lead edge and the scale
of 10mm
Z
Paper lead
edge
10
Paper (White paper)
illust: AR-280
50
20 30 40
400% enlargement copy
50
20 30 40
200% enlargement copy
11) Enter L1, L2, and L3 as follows:
L1 = X ´ 10
L2 = Y ´ 10
L3 = Z ´ 10
12) Cancel the simulation mode, make a copy in the document table
mode and in the SPF mode, and check that the lead edge image
loss and the void area are in the specified range as shown
below:
Lead edge image loss: 1.5 ~ 3.0mm
Lead edge void area:
If the above condition is not satisfied.
13) Enter the SIM 50-1 mode.
14) Set the scale on the document table in the same manner as in
procedure 3). Make a copy at 50% and at 400% in the document
table mode.
15) Measure the distance between the paper lead edge and the
copy image lead edge of 50% copy and 400% copy.
16) Check that there is no difference between the measured dis-
tance of 50% copy and that of 400% copy.
If the difference is more than 1.5mm, change and adjust the
RRC-A value.
Repeat procedures 12) to 16) until the above condition is satisfied.
17) Use the document made in procedures 1) and 2) and make a
copy at 50% and at 400% in the SPF mode.
18) Measure the distance between the paper lead edge and the
copy image lead edge of 50% copy and that of 400% copy.
19) Check that there is no difference between the above measured
distance of 50% copy and that of 400% copy.
If the difference between the distances is more than 1.5mm,
change and adjust the SPF value.
Repeat procedures 17) and 18) until the above condition is satisfied.
20) If the lead edge void area is outside the specified range, change
the DEN-A value.
21) If the lead edge image loss is outside the specified range,
change the IMAGE LOSS value.
22) If the rear edge void area is outside the specified range, change
the DEN-B value.
23) If the rear edge void area is outside the specified range, change
the REAR LOSS (SPF) value.
Image loss
Lead edge void area
IMAGE Lead edge
LOSS image loss
DEN-A Lead edge
void area
DEN-B Rear edge
void area
REAR Rear edge
LOSS image loss
6 – 15
1.5 ~ 3.0mm
Rear edge void area
1.5 to The greater the set value is, the
3.0 mm greater the image loss is.
1.5 to The greater the set value is, the
3.0 mm greater the void area is.
1.5 to The greater the set value is, the
3.0 mm greater the void area is.
1.5 to The greater the set value is, the
3.0 mm greater the image loss is.
7/13/2000