MX-6580N, MX-7580N (serv.man3). Service Manual (Revised June 2017). - Sharp Copying Equipment Service Manual (repair manual). Page 117

MX-7580N  ADJUSTMENTS AND SETTINGS  5 – 67

5)

Image loss adjustment

When the adjustment item of the image loss below is set to the
default value, it is adjusted to the standard state. If it is not in
the below standard state, or when it is set to a desired value,
change these adjustment items.

Void area: 4.0mm, Image loss: 4.0mm

When the adjustment value is increased, the image loss is
increased. When the adjustment value is decreased, the
image loss is decreased.

When the adjustment value is changed by 1, the void area is
changed by 0.1mm.

 

This adjustment must be performed in the following cases:

* When the scan control PWB is replaced.

* When the EEPROM on the scan control PWB is replaced.

* When the scanner (reading) section is disassembled.

* When the scanner (reading) section is replaced.

* When U2 trouble occurs.

* When the DSPF section is disassembled.

* When the DSPF unit is replaced.

This simulation is to adjust the scanning position when scanning in
the DSPF mode.

If this adjustment is made improperly, the scanner stop position is
shifted from the specified position and a shade of the document
table may be reflected on the lead edge section of the scan image
in the DSPF mode.

1)

Make a copy in the DSPF mode, and check for any shade on
the lead edge section of the copy image.

If there is any shade of the document table on the lead edge
section of the copy image, perform the following procedures.

2)

Enter the SIM 53-8 mode, and press [MANUAL] key.

3)

Enter an adjustment value with 10-key, and press [OK] key.

When the set value is increased, the distance from the home
position to the DSPF scanning position is increased. When the
set value is changed by 1, the scanning position is changed by
0.1mm.

Perform the procedures of 1) - 3) until a satisfactory result is
obtained.

CAUTION: After execution of this adjustment, be sure to execute

ADJ16C Copy image position, image loss, void area
adjustment (Manual adjustment) (DSPF mode).

 

This adjustment must be performed in the following cases:

* When the scan control PWB is replaced.

* When the EEPROM on the scan control PWB is replaced.

* When the scanner (reading) section is disassembled.

* When the scanner (reading) unit is replaced.

* When U2 trouble occurs.

* When the DSPF section is disassembled.

* When the DSPF unit is replaced.

1)

Prepare the adjustment chart.

The adjustment chart can be made by the following proce-
dures.

Use A4 (11" x 8.5") paper and draw arrow marks vertically and
horizontally on the front and the back surfaces.

LEAD

Image loss 
adjustment

Lead edge 
image loss 
adjustment

0 - 99

40

4.0

+/- 1.0mm

SIDE

Side image 
loss 
adjustment

0 - 99

20

2.0

+/- 1.0mm

5mm

 

5mm 

10mm 

100% 

200%

Paper lead
edge

Scale image 4.0mm position

5mm

10mm

 

4

3

2

1

Paper lead edge

Maginification ratio : 400%

Copy area

Image area

Papar lead edge

Shadow image of DSPF