Sharp DM-1500, Service Manual

Page: 74 / 188

2) Set the test chart so that the scale is positioned as shown below,
in the S-D mode and the D-S mode.
3) Execute simulation 50-18 to make a copy and check the front edge
image loss at the area where the scale is printed.
Adjust the setting so that the front edge image loss is less than 4.0
mm in the R-SPF mode.
An increase of 1 in setting represents an increase of 0.1 mm in
image loss.
B. Adjusting trailing edge void in duplex copyin
mode
This is the adjustment of the first surface printing mode (rear end void)
in duplex copying.
In a duplex copying operation, the paper is delivered starting from the
rear end of the first printing surface. It is therefore necessary to make
a void area at the rear end on the first printing surface to prevent paper
jam at the fusing part.
There are two adjustment modes:
1) Image cut rear end void quantity (R-SPF) 50-19(AE)
The size (length) of a document read from the R-SPF is detected,
the image at the trailing edge of the first printing surface is cut to
make a void area. (The adjustment of void quantity at the time
when the cassette paper size is not recognized.)
2) Paper trailing edge void quantity 50-19 (TEXT)
This adjustment is made when the cassette paper size is recog-
nized. The trailing edge void quantity can be adjusted by changing
the trailing edge image laser OFF timing.
The paper void quantity should be first adjusted before the image cut
trailing edge void quantity (R-SPF) is adjusted.
(Adjustment procedure)
(1) Paper trailing edge void quantity
1) Preparing test chart (Draw a scale at the rear end of one side of
a sheet of A/4 white paper or letter paper)
2) Set the test chart on the document glass as shown below.
3) Using the user simulation [18], set the paper size of the first cas-
sette.
Letter paper: 4
A4 paper: 3
4) Execute simulation 50-19 to turn on the TEXT lamp and make the
printing mode in OC-D mode.
Make a copy of the test chart to check the void area of the scale
on the image.
Adjust the setting so that the void area is 4 - 5 mm.
An increase in 1 of setting represents 0.1 mm in void area.
(2) Image cut trailing edge void quantity (R-SPF)
1) Set the test chart so that the scale is positioned as shown below.
2) Execute simulation 50-19 to turn on the AE lamp and make the
printing mode in the D-D mode.
3) Remove and reinsert the cassette.
NOTE: Make sure to carry out this step before making a copy
during this adjustment.
4) Make a copy and check the void area of the scale on the image.
Adjust the setting so that the void area is 2 - 4 mm.
An increase of 1 in setting represents an increase of 0.1 mm in
void area.
l Void position to be checked
Scale (S-D mode) Scale (D-S mode)
5 10
The front edge of the
scale on test chart
Front edge of paper
Void area
less than 4 mm
2nd printing surface where scale is printed (lower side)
Document guide The trailing edge has a scale
Table glass
Scale (D-D mode)
The trailing edge void on the first printing surface
is shown above.
Paper
Void position to be check
DM-1505
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