Banding Problems; Image Quality Problems - Contex XD2490 Service Manual

Banding problems

Image quality problems

3-4
Troubleshooting
Bad/no gray balance calibration (CIS module to
module match).
Scanning originals that have folds or is curled
on a CIS scanner is often taken as a defect on
the scanner, where it is actually a limitation of
the used technology. Due to the very short dis-
tance from sensor to surface of the original, also
called "Focal Length" we also have a very short
"Focus Depth" meaning, if the original is NOT
in contact with the glass plate it is very likely to
be out of focus!