Page 74 - Glass-Technology International no. 5-2018

ARTIFICIAL VISION SYSTEMS

defect, even the smallest.
During the setup phase,
the quality manager de-
fines the desired level of
sensibility for defect types.
Moreover, different sensi-
bility areas can be defined
on all the glass surface to
set higher sensitivity in the
centre instead of close to
edges.
AUTOMATIC PRINT
QUALITY VISION
SYSTEM

The automatic print sys- AUTOMATIC PRINT QUALITY
tem, installed immediately CONTROL VISION SYSTEM
after the printing machine, RECIPE CREATION PROCESS.
recognizes any ‘slavering’ THE OPERATOR COULD
or ‘widening’ of the de- SPECIFY DIFFERENT VALUES OF
sign details due to an ex- DEFECT THRESHOLD
cess of ink coming from
the screen. This type of acter verification) on text. the use of a high resolu-
inspection is able to detect The system is capable to tion monochromatic linear
fade out dots, pin holes, or perform retro actions, camera with 16384 pixels,
if there are missing parts of sending the adequate sig- that guarantees resolution
the design, alerting the op- nals back to the printing up to 60μm for 1,000mm
erator to verify the possible machine to automatically glass and 122 μm for
cause. modify the screen position 2,000mm glasses (on lead-
All the areas of the glass in real time, with the aim of ing long edges). It is able to
are checked and compared operating automatic limit- verify design quality up to
with the allowed tolerances ed screen adjustment start- a circular dot of 0.09mm2
specified in the glass in- ing from an optimal print. (on 1,000mm glass) or
spection recipe, which is In general, the software can 0.36mm2 (on 2,000mm
created as a ‘one-off’, us- send defined signals to the glass). The digital camera
ing preloaded images ob- printing machine’s PLC to acquires one line at time,
tained using ‘good’ glass or activate specific functions ‘scanning’ the glass during
the digital image. Different and automatically optimize its movement on the con-
sensibility areas can be de- the production. veyor. An innovative light-
fined on all the glass sur- The advantages of this in- ing system is adequately
face to allow higher con- novative system are the positioned to allow the
trol, for instance on logos possibility to verify print camera to have optimal
and barcodes. quality, tracking the de- light conditions. The faulty
A specific software option fects on images and, in the areas and the acquired im-
provides controls on par- case of errors, to automati- age are then showed on a
ticular details, for example cally correct frame position wide screen (42”) high
fiducial marks or special without stopping the con- resolution monitor and the
symbols or even ISO verifi- veyor. good glass image used in
cation on barcode/datama- The hardware on these the recipe creation phase
trix or OCV (optical char- two technologies foresees can be displayed in overlay.

72 Glass-Technology International 5/2019