screen technology
Interactive kiosks benefit from optical bonding
to overcome application limitations in
commercial environments
By Richard Murton, Managing Director, Display Technology Ltd – www.displaytechnology.co.uk
Even though mobile devices are becoming
more and more capable, they still have
a number of key limitations restricting
their usefulness to businesses aiming to
provide maximum customer service at
minimal cost. Instead, the implementation
of interactive kiosk displays is increasing
to allow customers to serve themselves
as much as reasonably possible, thereby
freeing up human staff without any
reduction in customer satisfaction.
Interactive kiosk displays have
numerous applications and benefits,
but also some challenges. It’s very easy
to assume that the display and touch
element is a simple desktop monitor with
a touchscreen. However, there are many
more factors that should be considered
to ensure a quality product that both
looks good, and is reliable.
Practical considerations
Some of the considerations are: who
will be using it? Where will it be used?
Will it be used in direct sunlight? What’s
the support structure? What’s the
expected life of the kiosk? All these
factors will have an influence on the
design and components used. It’s these
considerations that make a good or bad
kiosk and deployment.
Once an interactive kiosk display
has been successfully installed, the next
challenge is keeping it in one piece. Many
interactive kiosk displays are designed for
use by members of the public, with some
being heavy-handed and, of course, you
can’t risk the glass breaking and injuring
them. Even if the kiosk is intended for
use only by internal employees who,
in principle, can be trained, employers
have a duty of care towards them, which
means the kiosk display needs to be
appropriately robust.
It’s critical to ensure the screen is
readable, looks good and operates
well. Ambient light, be it sunlight or
artificial light, can reflect on the screen
making it harder to read. Displays are
notorious for washout in high ambient
light conditions. This effect is where the
contrast reduces dramatically through
front surface reflection and internal
light refraction. In some environments,
you may be able to limit the extent
but it’s much better using the correct
components and construction in the
initial design. There’s no point in having
a kiosk in direct sunlight where the user
has to shroud their arm around the
display to read the information or if the
touchscreen response is slow.
Another consideration is protecting
the interactive kiosk display from everyday
wear and tear. Dirt and dust in the
atmosphere can eat into the surface of
displays, as can liquids which includes
soft drinks. In some locations you can, in
theory at least, try to prevent people from
going near the kiosk display when they
have food. In practice, however, this is
never guaranteed, and in some locations
it’s unavoidable that some users will have
food or drink in their hands while they’re
operating the kiosk display.
A major issue, particularly in countries
such as the UK, is that it’s easy for damp
air to get behind the glass where it
becomes visible as fog or condensation.
This, of course, makes it harder to read
the content on the display. The final major
challenge is to deal with parallax, which
is basically an optical illusion that makes
it look as though pixels shift position
depending on where you stand in relation
to the screen. This effect is only possible
where there’s a gap between the cover
glass and the actual display.
Optical bonding to the rescue
The basic idea behind optical bonding
is that an optical-grade is used to seal
the gap between the cover glass and the
actual display. There are various options
available, but by far the most common
is silicone, which is non-reactive and
can withstand moisture. This is usually
enhanced by an anti-reflective coating or
anti-glare surface finish. Optical bonding
can eliminate all the issues currently
associated with interactive display kiosks
making them both more robust and
more effective, giving users a much more
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