The Magic of Polarization (on an LCD screen)

[ella5024]

Use it to video some people. You can see which ones are human and which ones are alien greys.

[danrichards23]

the first pair of polarized sunglasses i had i was trying to get gas and the screen on the pump was black and i thought it was broken.

[Films4You]

Watch this :-

watch?v=KM2TkM0hzW8

[alex681219]

tks...i need a polarized sheet for my project...see the video response

[Nilguiri]

Once you've got it completely black, put another polarizing filter in between and see what happens when you rotate that one.

[Puneet21iitd]

can u explain ur work......................to me

[joshman800000000]

what work?

[SpeedzterZ6]

I think he means tell him how to do it, I'm interested too

[joshman800000000]

oh, well, this is just a circular polarizer for a camera lens. when rotated just right, the direction of the polarization in the filter (you can only polarize in one plane (i.e. vertical, horizontal, etc)) completely blocks out certain wavelengths of light coming in in that same direction/angle (thus as it rotates, the light fades. why the LCD screen goes COMPLETELY black, i don't fully know. generally this filter is to cut out glares on water and windows. hope that helps.

[LordSuva]

Cause light coming from LCD screen is already polarized. Liquid crystals in screen align when they get electric current, thus creating a polarizer. There is a sheet of polarizing material in front of the liquid crystal panel. If the light is being polarized by crystals it will be cancelled by the sheet. If it isn't, it's only polarized (not cancelled) by the sheet. But you cancel it with your filter. :P

Very complex way to explain teach simple stuff. :P

[joshman800000000]

nice. i can accept that.

[7677890]

LCD displays use liquid crystal, a chemical which, when an electric current is passed through it, aligns molecules to polarise incoming light.

The backlight emits light which is polarised and passed through coloured filters to get the RGB dots on the screen. cells of liquid crystal on top of those filters are polarised and depolarised using small electrical currents at 90 degrees to the backlight polarisation. A polarised cell will block light.

[eyescreamcake]

@joshman800000000 it's not blocking "wavelengths" of light, it's blocking polarizations of light.

[AdventNoob]

@Puneet21iitd your answer is here: meadowlarkDOTcom/applicationNo­tes/Basic%20Polarization%20Tec­hniques%20and%20DevicesDOTpdf