Panel technology used on large displays?

Hello everyone.

I'm currently working on a school project (A buyer's guide on LCD's) and I've encountered a pretty dumb problem.
Neither manufacturers nor educational sites like TFTcentral actually state which panel technology is being used on large TV screens (from 32" up to 75" and beyond).
Does anyone know? Is it TN, IPS or VA? Or maybe something entirely different? In this article, I found that TN panels can be up to 28" large. But what about the super large displays? IPS can't be it, since they're usually up to 32" in size. So what is it now?

Any help will be appreciated.
Tam (Also, excuse my shitty English. I know I make stupid mistakes from time to time.)