Cutting down on glare w/ a circular polarizer

**netchris** · 03-03-2007, 07:03 PM

These circular polarizers are designed basically as 1 way light filters.

Say the polarizer was placed on top of the touch screen (which from what I know about our touchscreens, it should work since they are pressure touchscreens and the polarizer wouldn't be putting any pressure on the screen). The light hits the polarizer, bounces off the LCD, and gets blocked on the way out. The light coming from the LCD shouldn't be any dimmer with the polarizer on top of it because the LCD's light is already polarized.

With too much direct light on the display, it will probably still be washed out, but at least there won't be any glare..

Sound like a good idea guys?

**elserpiente** · 03-03-2007, 07:28 PM

the link your pointing to is not working, i believe you are referring to: http://www.polarization.com/shop/catalog/index.html
and scrolling down to "Circular Polarizing Sheets".

They look promising, it would be interesting to see one of these applied on an lcd touchscreen.

**netchris** · 03-04-2007, 11:25 AM

Originally Posted by elserpiente

the link your pointing to is not working, i believe you are referring to: http://www.polarization.com/shop/catalog/index.html
and scrolling down to "Circular Polarizing Sheets".

They look promising, it would be interesting to see one of these applied on an lcd touchscreen.

Ah you're very right. I've re-done the link to correct the error.

I might try one of these. They also sell some with an adhesive which looks nice, but then if this doesn't work I don't want it to be stuck on my touchscreen. I'll have to ask the guys at polarization.com their opinion on the matter.

I still need to get some of this stuff for my clock face for one, so I suppose it won't be too hard to justify the cost.

**RickS** · 03-04-2007, 05:01 PM

I bought a sheet to check it out, will post pics if it works.

**netchris** · 03-05-2007, 05:47 PM

Originally Posted by RickS

I bought a sheet to check it out, will post pics if it works.

Awesome, glad to hear it! I hope it works well.

Did you get the one with the adhesive backing or without?

**RickS** · 03-05-2007, 06:13 PM

I got it with the adhesive...figured it would be interesting to see how it affects the TS.

**Motorcity** · 03-06-2007, 12:30 AM

I don't think it will work. On a resistive touch panel, the sensor needs to be unobstructed to correctly identify the touch location perameters. Adding an adhesive backed filter to the top of the touch screen will most likely render it useless. And good luck removig it from the panel once it is applied. Having this film applied directly on top will create a larger surface area that receives the touch, since the adhesive will bond the touch sensor more closely and not allow for as much free movement. So if you touch a point now, the touched area is the diameter of your finger tip. With the film added, the touch area becomes the size of a quarter, or even a half dollar. should make for a very inaccurate touch. If it even works at all.
Yes, it might actually work. Who knows? But given what I do know about these panels, I highly doubt it.
Good luck.

**2k1Toaster** · 03-06-2007, 12:40 AM

Well the back of the panel I think should be ok because you could calibrate it out I think.

I don't know how it really works this way because it really is just 2 panes of glass, but when I got my replacement TS I put it in backwards, and no matter where I touched I got nothing. I flipped it around, and voila, it worked. So I don't know if my TS was just haunted, but maybe the back of the glass is ok?

And if it doesn't work, a replacement panel is only like $50.

**Motorcity** · 03-06-2007, 12:56 AM

Your touch panel is not 2 panes of glass. There is 1 pc of glass substrate as a base, a spacer layer, and 2 ITO layers (the touch sensor part) bonded together. Resistive sensors only work one way. That is why you could not get it to work when it was backwards.
http://www.elotouch.com/Technologies...howitworks.asp

Adding that circular polarizer to the glass side (non touch) of the touch panel won't work since the polarizer would be backwards to the viewer, making the effects useless.

**2k1Toaster** · 03-06-2007, 12:59 AM

well it was 2 parts something, I just figured glass.

But why would it not work on the bottom side? If you keep it facing the same way, basically the adhesive side would not be stuck, as long as it is between you and the lcd, it should be fine right?