How to test
1 • Fit a terminator to one SCSI connector on the scanner and SCSI
cable and RS 232 service cable to the scanner and PC.
2 • Set the Dip switch to 8, (on).
3 • Turn on the PC or Mac and access the service program main menu
(section 3•5).
4 • Mount the UGRA test target firmly onto the drum.
5 • Switch on the scanner and start up Photoshop plug-in.
6 • Make a preview of the UGRA test target.
7 • Perform a focus calibration on the target.
8 • Crop an area of the test target with the 12 circles as shown in fig. 1.
9 • Choose the following settings in Photoshop:
Transmission gray scale.
Aperture 1
Neutral gradation curve
Gamma 0.78
600 dpi resolution.
White/black point: max. 255
min. 0
10 • Make a scan of the area.
11 • Select Adjust levels in Photoshop image menu.
12 • Define the background of the circles in the Levels window by
clicking on the white marker A and moving it to the right peak of
the histogram as shown in fig. 1.
Note: adjustment must be at least 250 for white point.
13 • Select Map threshold in Photoshop image menu.
14 • Click on the marker in the Threshold window and set a value of
128 (fig. 2).
15 • For correct sharpness of focus, a few pixels should be visible down
to at least 6 microns.
Note: Interpretation of pixel saturation is difficult, however fig. 2
gives a guideline of how the spread should appear. Be aware that
dust on the test target can give false indications.
Service Manual • ScanMate 4000/5000 Edition 1 • January 1996
Focus Sharpness
5•11b
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