HP Designjet T2300 HP Designjet T2300 eMFP Printer series - Image Quality Trou - Page 23

Random vertical lines, Wrinkles or folds, Scan-quality issues - price

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In this chapter the most common defects and failure modes are shown, sorted by relevance and frequency of appearance. A defect is a common image artifact that usually appears when using any CIS scanner. These are due to incorrect settings, product limitations or easily solvable mistakes. A failure mode is due to malfunctions of some of the scanner components. Some of the corrective actions proposed here require the use of the Scanner Diagnostic Plot, which you can print and scan as indicated in The scanner diagnostic plot on page 41. Please do not use any printed version of this guide to test the scanner, as the resolution of the images included here is insufficient. Use the diagnostic plot when recommended in response to any of the errors described in this chapter. Random vertical lines This is one of the most common issues in sheet-fed scanners. Usually, the vertical streaks are caused by dust particles inside the scanner, or miscalibration of the scanner (in these cases, the problem can be solved). Here are some examples of images suffering from vertical lines or streaks. Please note the black arrow indicating the scanning direction in these examples. Scan-quality issues Actions 1. Clean the scanner's glass plate and the original to be scanned as described in Clean the scanner's glass plate on page 38. Re-scan your original afterwards. 2. If the streaks remain, recalibrate the scanner as indicated in Calibrate the scanner on page 39. Make sure you clean the maintenance sheet before calibrating the scanner, and check that the maintenance sheet is not damaged (if so, call HP support and ask for a new maintenance sheet). Re-scan your original after the calibration is completed. 3. If the streaks still remain, check the scanner's glass plate visually. If it is damaged (scratched or broken), call HP support. 4. If the streaks remain, there may be dust particles inside the glass plate. Carefully take out the glass plate and clean it as described in Clean the scanner's glass plate on page 38. NOTE: The problem of vertical streaks cannot always be solved, due to the technological limitations of CIS scanners. If the streaks remain after the corrective actions explained above, then no further action can be taken to improve the image quality, except to buy a more expensive CCD scanner. Wrinkles or folds Scanners based on CIS technology have a high optical resolution within their focus plane, at the price of a very limited depth of field. Hence, the images are sharp and detailed when the scanned original is perfectly flat against the glass plate. However, whenever the original contains wrinkles or folds, these defects are clearly visible in the scanned image (as shown in the following example). ENWW Random vertical lines 19

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In this chapter the most common defects and failure modes are shown, sorted by relevance and
frequency of appearance. A defect is a common image artifact that usually appears when using any
CIS scanner. These are due to incorrect settings, product limitations or easily solvable mistakes. A
failure mode is due to malfunctions of some of the scanner components.
Some of the corrective actions proposed here require the use of the Scanner Diagnostic Plot, which you
can print and scan as indicated in
The scanner diagnostic plot
on page
41
. Please do not use any
printed version of this guide to test the scanner, as the resolution of the images included here is
insufficient. Use the diagnostic plot when recommended in response to any of the errors described in
this chapter.
Random vertical lines
This is one of the most common issues in sheet-fed scanners. Usually, the vertical streaks are caused by
dust particles inside the scanner, or miscalibration of the scanner (in these cases, the problem can be
solved). Here are some examples of images suffering from vertical lines or streaks. Please note the
black arrow indicating the scanning direction in these examples.
Actions
1.
Clean the scanner’s glass plate and the original to be scanned as described in
Clean the
scanner’s glass plate
on page
38
. Re-scan your original afterwards.
2.
If the streaks remain, recalibrate the scanner as indicated in
Calibrate the scanner
on page
39
.
Make sure you clean the maintenance sheet before calibrating the scanner, and check that the
maintenance sheet is not damaged (if so, call HP support and ask for a new maintenance sheet).
Re-scan your original after the calibration is completed.
3.
If the streaks still remain, check the scanner’s glass plate visually. If it is damaged (scratched or
broken), call HP support.
4.
If the streaks remain, there may be dust particles inside the glass plate. Carefully take out the glass
plate and clean it as described in
Clean the scanner’s glass plate
on page
38
.
NOTE:
The problem of vertical streaks cannot always be solved, due to the technological limitations
of CIS scanners. If the streaks remain after the corrective actions explained above, then no further
action can be taken to improve the image quality, except to buy a more expensive CCD scanner.
Wrinkles or folds
Scanners based on CIS technology have a high optical resolution within their focus plane, at the price
of a very limited depth of field. Hence, the images are sharp and detailed when the scanned original is
perfectly flat against the glass plate. However, whenever the original contains wrinkles or folds, these
defects are clearly visible in the scanned image (as shown in the following example).
ENWW
Random vertical lines
19
Scan-quality issues