Horizontal Polarization Using LCD Screen Sheets

[frogmaster]

Recently I smashed a laptop screen and decided to pull it apart to see how it works.

Inside are a pair of sheets of plastic called horizontal polarization filters. I found that shining any laser through them creates a wonderful line effect.

I was just wondering how this works, and if there are any applications for this (probably not new) discovery.

Many thanks for any tips or tricks. The effect is really cool, the line is brightest at the edges and dimmest in the center, but a perfect line nevertheless.

 

[Cyparagon]

Those aren't polarizing filters. Those are a type of fresnel lens used to diffuse the backlight. The polarizing filters are most often embedded in, or glued to, the glass LCD panel itself.

 

[Alaskan]

Cyp. is posting more than I've ever seen him, must be bored

 

[Cyparagon]

Thank you for your contribution, even though that has precisely nothing to do with this thread. Not that I owe you any explanation, but I haven't been on the forums in a few weeks, and I'm just catching up.