Edition 64 (October-December, 2021)

ISRA VISION• 2
Deflectometric surface inspection of the end product
©ISRA VISION AG
second while also enabling the highest
image resolution. At the same time,
customized lighting supports the
reliable detection and intelligent
classification of defects that would be
invisible to the naked eye. In turn,
this allows conclusions to be drawn
regarding causes or defective process
parameters, which can be continuously
monitored and optimized.
Fully automatic inspection of display
glass
Thin display glasses are also subjected
to a fully automatic inspection just
like optical films. ISRA VISION FPM-
Inspect (FLAT PANEL MASTER)
combines tried-and-tested technologies
for optical quality control with precise
materials handling technology for use
in clean rooms. This allows the system
to identify even the tiniest surface,
glass, or edge defects.
In addition, FPM-Inspect monitors
particle contamination on the
substrate, thus enabling conclusions
to be drawn regarding the air quality
in the cleanroom. Here, too, the
inspection system works with mature
software algorithms to improve the
production process and to detect and
eliminate the causes of defects.
When it comes to the 100 per cent
monitoring of evenness, rippling,
and reflection optics even in large
glass surfaces, ISRA VISION P2
(PowerPlate) delivers precise data in
a matter of seconds. Alongside defects
in and on the material, this also allows
the immediate detection of 3D shape
defects, preventing the materials in
question from being processed further.
Perfect union: Quality control before
and after joining
Perfect optical films, thin films, and
display glasses form the basis of
high-quality displays. However, they
only become a fixed unit with optical
characteristics and functionality once
they have been joined together during
production.
In this production step, quality
control is just as important as
inspecting the raw materials: Dimples
on the cover glass and other defects
can occur when adhering the layers,
which cannot be recognized with the
naked eye but compromise the optical
properties and function of the product.
SpecGAGE3D was specially
developed to reliably detect local
unevenness, supporting structures, or
read-throughs before and after joining
the display layers using deflectometry.
To do so, a stripe pattern is projected
onto the display and the reflection
is captured by multiple cameras and
subsequently evaluated. Any detected
defects are then classified immediately.
Curved glasses and displays: A special
challenge
Deflectometry is perfectly suited
for the inspection of curved glasses
and displays, for example for cover
glasses of smartphones. Curved edges
and concave shapes are becoming
increasingly popular here and in the
automotive industry since displays
of the same size require a smaller
installation width. And the shape
allows information to be seen more
easily on the edges. At the same
time, they set even more stringent
requirements in terms of quality
inspection, as the fit and shape must
be exactly right in addition to the
perfect surface and optical quality.
The SpecGAGE3D inspection
system from ISRA VISION enables the
efficient and reliable shape inspection
ISRA VISION Flatpanel Master performing thin glass surface
inspection for displays
©ISRA VISION AG
Glass Bulletin | October - December, 2021 83