Polarising sunglasses and trip computer

Polarising sunglasses improve visibility in traffic, and therefore safety. My 307SW trip computer however turns completely black! When I tilt my head

90 degrees, it is perfectly clear again.

Does anyone know a solution to this problem? Do any other screens (navigation) have the same problem?

Regards, Erik.

Reply to
Erik
Loading thread data ...

It's to do with the way the display is manufactured - it will be some kind of LCD screen that uses polarizing filters in its construction (google: 'how lcd works' and 'how polarizing filters work'). Since the light leving the display is already polarized (travelling in one direction), when it hits your sunglasses it is blocked because they must be polarized in the other direction. That's the reason why turning your glasses 90 degrees alows the light back through, as the polarization is now in the same direction as the display! I would have thought most lcd screens would suffer to some degree, but it depends how good the display and your sunglasses are.

Reply to
blaildyors

Try putting various bits of plastic sheeting in front of the trip computer (I suggest you try clear plastic bags, cellophane, the wrappers from cigarette packets etc.. Also thicker plastic like CD casing might work).

The problem is that the LCD on the trip computer has a polariser in front of it (just part of how LCDs operate), which is apparently oriented to produce horizontally polarised light - exactly what your polarising sunglasses remove! Various polymer films (i.e. plastic sheeting) are birefringent, which means that they can change the polarisation of the light. If you find just the right type and thickness, it should let you see the trip computer again!

Reply to
Albert T Cone

What an excellent reply :) The wonders of physics :)

Reply to
Nom

Hehe. *curtseys*. :) Not heard from you for a bit - you been away, or just hiding out from urcm?

Reply to
Albert T Cone

Neither - I just no longer have any interest in the mods group. It's full of retards these days :)

Reply to
Nom

Hehe. Cheers. I'll pass on your regards :)

Reply to
Albert T Cone

LMAO !

Reply to
Nom

MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.