Polarisation Filter On Touch Screen; Basics - Volkswagen RNS 510 Manual

Large glare effect without polarisation film
Glare effect
Monitor picture
Polarised light
Light waves
S397_040
Non-polarised light
S397_041
Lower glare effect thanks to polarisation film
Polarisation film
Monitor picture
External light
Viewer
S397_042
One oscillation level
Different
oscillation levels
Viewer
S397_043

Polarisation filter on touch screen

Smooth surfaces like glass reflect light so that the
picture on a monitor is difficult to see when light
conditions are too bright.
Polarisation filters are used to change the reflection
behaviour and thus reduce glare effects. They consist
of a plastic film of long, parallel molecule chains.

Basics

Electromagnetic beams like visible light, can be
imagined as waves.
With polarised light, as emitted by lasers, for
example, all waves oscillate only on one oscillation
level.
With other light sources, for example, like the sun, the
oscillations are on many different oscillation levels
that are turned against each other. This kind of light is
non-polarised light.
The effect of polarisation films is that only light can
pass through the polarisation film that oscillates in
one level, which is set by the parallel arrangement of
the molecule chains. Waves that oscillate in other
levels are absorbed by the film. This means that only a
fraction of the external light is reflected and the glare
effect is reduced considerably.
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