The
fact that a large
format colour scanner and indeed a document scanner of any size needs a
little maintenance from time to time is very often ignored. The
good news is that maintenance takes just a few minutes and will be
rewarded by much better scans and copies. Regular daily
maintenance should involve the Normalisation process but some of the
other issues listed below can also occur through rough handling
but can nomrally be fixed by following the maintenance
procedures.
Cx 40
scanners do not have have a tendency to suffer LEFT/RIGHT stitch
disturbance because their optical resolution does not rely on
magnification which is affected by document creases and folds.
camera to camera consistency
The Gx 42 contains 5 cameras and the Gx 25 three. The Cx 40 scanner also contains 5 optical sensor devices. If the copy or
scan file shows some colour differences at intervals of a 1/5 or
a 1/3 across the scanner then it will most probably be due to the
following:
Reason#1: The temperature inside the scanner has not stabilised properly because the device has not been allowed to warm up. Remedy:
Leave the scanner switched on for 1 hour and then re-normalise with
clean white paper using the Gx Utilities or Cx Utilities programs.
Reason#2: The scanner is already warm but was last normalised for a
different room temperature (different by > +/- 5
degrees C) Remedy: Use Gx or Cx Utilities to normalise the scanner at the working room temperature.
NOTE:
These actions are considered part of routine scanner maintenance.
For black and white scanning they are not so important. The
picture below is an example of the effect produced by not
normalising the scanner at the appropriate time i.e. when it and
the room temperature is stable.
camera to camera stitch
The
Gx 42 and Gx 25 contain multiple cameras. If the copy or scan file
show problems with thin lines or edges of objects at intervals of a 1/5 or a 1/3 across
the scanner then it will most probably be due to a camera stitch issue:
FRONT/ BACK
If horizontal lines, for example the rim of the glass (see picture to
right) is displaced in the direction of paper movement this will
indicate a Front/ Back stitch error.
There may, or may not be a Left/Right error at this camera intersection
as these are not so easy to spot unless there is a diagonal line
discontinuity or distortion of an object of recognisable shape e.g. a
circle on the original document at this point.
Reason: The scanner may have been handled roughly or subjected to
intense temperature changes recently. However, this effect is hardly
ever serious and can be repaired with some simple maintenance
(electronic) using the Stitch Target included with the scanner. Remedy:
Use Gx Utilities to re-stitch the scanner at this room temperature
after the unit has been switched on for 1 hour This process will
take about 3 minutes.
NOTE:
The maintenance procedure described above will repair stitch problems
caused by camera misalignment. Stitch irregularities can also be caused
by irregularities in the document or the passage of the document
through the scanner.
Cx 40 scanners require re-stitching in a similar way using the Cx
Utilities program. For stitch maintenance to be most effective
Cx 40 scanners should also be allowed to adjust to room temperature
before carrying out routine maintenance.
Cx 40
scanners do not have have a tendency to suffer LEFT/RIGHT stitch
disturbance because their optical resolution does not rely on
magnification which is affected by document creases and folds.
If diagonal lines have been broken, shapes have been distorted
(overlapping left right) or picture data is repeated (cameras moved
apart) but horizontal data is not affected, this indicates that
the scanner needs left/ right stitch maintenance.
Reason: As above, although maintenance for this type of stitch effect
is more rare. See the example above (cameras too far apart). Remedy:
Use Gx Utilities to re-stitch the scanner at this room temperature
after the unit has been switched on for 1 hour This process will take
about 3 minutes.
Cx 40
scanners do not have have a tendency to suffer LEFT/RIGHT stitch
disturbance because their optical resolution does not rely on
magnification which is affected by document creases and folds.
FALSE DIAGNOSES
For Gx series CCD scanners 'paper lifting optical effects' caused by heavy creasing or folds can be often be confused with a permanent LEFT/ RIGHT
camera problem. Check the maintenance level of the scanner by
scanning the flat stitch target BEFORE re-stitching the scanner. Remedy: flatten the document and re-copy or scan For Cx 40 scanners the
majority of false alarm stitch diagnoses arise from evidence of FRONT/
BACK stitch effects in the copy or scan. In this model of scanner
there are two main causes:
Reason#1: Paper lifting, heavy creasing or folds can cause irregular paper velocity between sensor lines Remedy: flatten the document and re-copy or scan
Reason#2: Thick, heavy documents suddenly meeting rear roller can cause unexpected document speed reduction and irregular paper velocity between sensor lines Remedy: rescan the document, rotate the document and/ or slow the copy speed down
NOTE: For more detailed information on camera stitching please refer to the service manual for the relevant scanner model.
grey or off-white backgrounds in colour or greyscale copies
The
background of a technical drawing when copied as a greyscale or colour
document may appear slightly grey (plan copier output) or off-white (newspapers). In extreme cases there
may be varying levels of grey corresponding to the separate cameras (Gx
Series) or CIS arrays (Cx 40) making up the scanner.
Reason#1: The scanner is not fully warmed up or the scanner was last normalised at a very different room temperature. Remedy:
Allow 1 hour then re-normalise using the normalisation target supplied and the scanner Utilities program.
Reason#2:
The standard normalisation target supplied with the scanner or paper
used to normalise the scanner is whiter than the background of the
document being copied or scanned. Remedy:
Allow 1 hour (if recently switched on) and then re-normalise using paper closer in whiteness to the
document being copied using the Utilities program
OR use the brightness control to lighten the image Reason#3: The document uses a non-white paper. Remedy: Copy the document in black and white mode if colours are non-essential.
See the Tutorial - Copying
colour performance
SmartLF
All-in-One relies on the Microsoft Windows printer and its colour
management profiles for the colours generated in the copies it
produces. If the colour performance is not satisfactory it may be
necessary to change to a higher specification media. Matt
coated
papers generally give very good results for CAD and general technical
work
but photos require photo-gloss or satin-gloss papers.
For better colour accuracy it could be worth considering the
CopySmart product available as an additional cost option from
Colortrac. This software has an internal colour profiling
system based around IT8 targets and is also due to have support for the
Eye-One Gretag MacBeth colour spectrophotometer (last quarter of
2007).
speed issues
SmartLF
All-in-One can only begin printing the copy from the original once the
complete file has been processed and sent to the Windows printer.
The time to start printing is heavily related to the processor speed and
amount of RAM (random access memory) inside the computer and the Image
detail requested in SmartLF's Image Controls section. A black
and white D or A1 size landscape copy at 200 dpi will normally start
about 5 seconds after scanning completes on a 2.4 GHz XP computer with 512MB
RAM.
For best copy performance enable the 'Spool print documents so program finishes faster' and 'Start printing immediately' radio buttons.
copy slightly larger or smaller than the original
SmartLF All-in-One
unlike many standard Windows printer compatible applications is specifically designed to
preserve the size of the original. If the size of the copy is
smaller or larger than the original in the paper direction or across
the scan width this could indicate the scanner may need attention by a
qualified service technician.
2
Troubleshooting SmartLF All-in-One
SmartLF
All-in-One software relies on Windows printer drivers for
copying to large format printers. Install the driver following
the manufacturer's instructions. The printer may be connected
either by USB2 or by Ethernet. Common
problems encountered when copying with SmartLF All-in-One are as
follows:
The
largest factor affecting the time taken to copy is over-specifying the
Image detail or resolution used by the smartLF scanner. For all
general copying we recommend you use 200 dpi. Raising the dpi to
400 dpi will increase the amount of time the computer spends preparing
the data to send to the Windows printer driver. Generally it is a
good idea to maintain the printer quality at normal to high unless you
have a lot of draft black and white copies to make.
changing the copy quality
Copy
quality is affected by the scanner Image detail and the printer
quality. We recommend that the printer quality is not changed and
maintained at normal to high. For very small detail in an
original it will be necessary to raise the Image detail in the SmartLF
All-in-one Image control settings. image controls
discoloured areas to side of copy
These
are produced when the scanner copies the roller around the sides of the
original. This can be avoided by switching on Auto Size.
Alternatively make a file of the orignal using the Crop function preview & crop
blueprint copies are not being copied cleanly
For
efficient semi-automatic cleanup of variable backgrounds
select Adaptive Black & White Thresholding and enable the
Aggressive radio button
colour match to original is not close enough
SmartLF All-in-One does not employ colour profiling and colour management as part of its workflow.
lines in the copy not in the original
This
is most probably due to dirt on the glass OR DIRT ON THE GLASS WHEN THE
SCANNER WAS NORMALISED. Clean the glass with a lint-free cloth
and a suitable good quality glass cleaner and then re-normalise using the
Utilities program for your scanner.
