Edge roughness, text quality – HP Latex 3000 Printer User Manual
Page 284
Possible causes
●
Uniform variations from tile to tile. When color changes uniformly it must be within the color
consistency specification; see
for more details. Usually grays are much
more sensitive: differences of much less than 2 dE 2000 may be visible, although other colors would not
show a difference.
●
Small color variation left to right. The tile itself looks uniform, but when putting it beside the adjacent
tile the differences become visible.
●
Local color variations. See
Local color variations on page 277
. Sometimes these defects become visible
only when printing tiles, showing in one of the tiles but not in the adjacent. They are also more visible
when printing grays.
Possible solutions
●
Try to ensure uniform printing of all tiles, and all tiles printed in the same run.
●
Rotate every other tile, to compensate for left to right differences.
●
Adding spit bars at both sides of the image helps overall, especially when there are local color
variations.
Edge roughness, text quality
The edges of objects may appear rough or blurred; this is especially noticeable in text.
There are five possible causes:
●
Bleed: see
Bleed, halo, wicking on page 276
●
Printhead alignment. As each ink is deposited by two printheads of the same color, it is important that
the two printheads are correctly aligned. When a color is formed by a combination of inks, which is often
the case, it is also important that printheads of different colors are correctly aligned.
To check printhead alignment, print the printhead alignment diagnostics plot (see
), and fine-tune the alignment by identifiying the offenders in the plot.
●
Substrate advance. Before trying to adjust any parameter, make the following checks:
◦
Check that no substrate-advance factor was set earlier that could prevent the substrate-advance
sensor from working correctly.
◦
Run the diagnostics to check that that the substrate-advance filter is not dirty.
If the substrate advance is incorrectly adjusted, particularly if it is under-advancing, a dark line can
appear between passes. When the problem of line roughness or text quality applies to all colors and
appears in the substrate axis direction, it is likely to be related to incorrect substrate advance. Another
clue that could point to substrate advance as a cause is to observe that the defect is not constant,
appearing and disappearing along the print in the substrate axis.
278 Chapter 10 Troubleshoot print-quality issues
ENWW