Sharp SF-2014 Service Manual page 77

VI. Adjustment procedure
1) Set a half-tone paper of A4 or 8 1/2" x 11" on the document
table.
2) Set the exposure level to the min. level in the photo mode,
and make a copy on A4 or 8 1/2" x 11" paper.
3) Check the uniformity. If there is any unevenness, perform the
following procedures.
4) Move the exposure adjustment plate of the lighter copy sec-
tion towards Y or move the exposure adjustment plate of the
darker copy section towards X.
(Example)
If a copy shown below is made, move the front frame side of
the sub exposure adjustment plate in the direction of X to
adjust the exposure balance.
Paper exit
direction
Half-tone copy
Standard fixing position
Y Y
X X
Exposare adjusting plate
5) Make a copy in the same manner as procedure 2), and
check the uniformity.
Repeat procedures 1) to 5) until proper uniformity is ob-
tained.
VII. Troubles caused by improper adjustment
Less exposure
(Dark copy)
[Fig. 1]
Hole
(Center)
Exposare
adjusting plate
Y Y
X X
(8) Image loss/void area adjustment
The image loss/void area adjustment is performed by the combination
of the copied image position adjustment on the copy paper and the
void area adjustment.
Since the image loss and the void area are closely related each other,
they must be adjusted simultaneously.
(Definitions of image loss and void area)
Void area: Empty (white) area on a copy paper (without toner on it)
Image loss: The quantity (length) of an image lost on a copy paper.
(Document)
(Copy)
Paper lead
edge
a. Copy image position adjustment (SF-2014/2114)
I. Summary
In order to adjust the copy image position on a copy paper, the
lead edge position of an image on the photoconductor for the
lead edge position of a document on the document table is
changed with simulations 50-1, and the relative position of the
paper to the image position on the photoconductor is changed.
In the models which have no zoom copy functions, however, the
lead edge position of an image on the photoconductor for the
lead edge position of a document on the document table is not
changed.
The relative position of the paper is changed at OFF timing of
the scanner home position sensor after starting scanning to ad-
just the copy image position on the paper.
On the SF-2214, to adjust the copy image position on a copy
paper, the lead edge position of an image on the photoconduc-
tor for the lead edge position of a document on the SPF is
changed with simulations 50-1.
After adjusting the copy image position with the above proce-
dure, the M.C grid OFF timing for the lead edge position of an
image on the photoconductor is changed with simulations 45-1
to adjust the void area.
II. Purpose
The purpose od this adjustment is to improve separation in the
photoconductor section and in the fuser section and reduce dirt
on the fuser section pawl by obtaining the max. effective copy
area and the proper void area.
III. Note
If the proper void area is not obtained, the separation ability in
the photoconductor section may be degraded and dirt on the
fuser section pawl may be increased.
Before performing this adjustment, the following adjustments
must have been completed. If not, this adjustment cannot be
performed properly.
* Adjustment of paper pressure against the SPF resist roller
(Sim 51-2 set value must be properly set.)
* Adjustment of the copy image position on the copy paper
(Sim 50-1 set value must be properly set.)
7 – 19
Li
Li: Lead edge image loss
Lv
Lv: Lead edge void area
(In some cases, Lv > = Lv)