Sharp AL-1552, Service Manual

Page: 5 / 46

AL-1552/AL-1553 DUPLEX-RELATED ITEMS
1 – 4
4. Duplex adjustment
A. Adjusting the paper reverse position in memory
for duplex copying
This step adjusts the front surface printing (odd-number pages of a doc-
ument set) in the S-D mode copying and the leading edge position of an
image on even-number pages in the D-S mode.
That is, it covers the adjustment of the second surface printing mode
(image loss at the front edge of an image) in which image data is once
stored in memory.
The image data is read, starting from its front end in the document deliv-
ery direction (Reference direction of document setting in the OC
mode)and stored in memory.
This stored image data is printed starting at the printing start position, in
the order of last-stored data to the first-stored data.
In other words, the front edge image loss of the image can be adjusted
by changing the document read end position.
(Adjustment procedure)
1) Preparing test chart (Draw a scale at the rear end of one side of a
sheet of A4 white paper or letter paper).
2) Set the test chart so that the scale is positioned as shown below,
in the S-D 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 Duplex mode.
An increase of 1 in setting represents an increase of 0.1 mm
in image loss.
B. Adjusting trailing edge void in duplex copy 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.
Adjustment modes:
1) 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.
(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 cassette.
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.
5 10
Scale (S-D mode)
5 10
The front edge of the
scale on test chart
Front edge of paper
Void area
less than 4 mm
• Letter paper : 4
• A4 paper : 3
2nd printing surface where scale is printed (lower side)
Document guide
The trailing edge has a scale
Table glass
The trailing edge void on the first printing surface is shown above.
Paper
Void position to be check