science: a quick tangent

Oct 22, 2008 10:44

In the comments, someone mentioned the LCD. As it turns out, they got the explanation for how it works somewhat right. Somewhat ( Read more... )

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redchunks October 22 2008, 20:15:28 UTC
BRAIN EXPANDING... *pop*

No seriously, that just refined my understanding of what's going on in my watchface or on my monitor now... I was just operating under the assumption that the molecues wouldn't align until a field was applied, but now I see it's that they're already self-organizing into a particular alignment. It's how you set up that alignment's interaction that controls the transmission/blocking of light.

As for certain LCD's being hard to view at certain angles, that's more of just the display itself and not the atoms, eh? (i.e. polarized glass)

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mrotakki October 22 2008, 21:40:24 UTC
Glad to hear that you're getting something out of these posts!

Viewing angles are in part due to a little of column A and a little of column B. The polarizer has a great deal to do with it to some degree, but it's also clear that because you're waveguiding light, the incident angle you're viewing is going to be critical to how much light your eyes actually get.

That's something I'm not horribly familiar with, unfortunately, so it might be best to find an optics engineer to explain that one!

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mackys October 22 2008, 21:37:34 UTC
Can't they somehow integrate one of the necessary polarizations into the nematic material itself, thus avoiding one of the polarization filters? (Yeah, I know, "polarizers are cheap, why bother...")

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mrotakki October 22 2008, 21:49:13 UTC
Unfortunately, not really. The big assumption in this entire set-up is that (here comes the huge physics word of the day) the nematic material is uniaxial. In other words, the index of the material along the long axis is different from the orthogonal axis. There is an index for the parallel and perpendicular axis (to the long axis of the molecule). The perpendicular index is what allows polarized light to move "unmolested" and the index parallel to the long axis interacts with the polarized to allow for wave guiding ( ... )

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