Why do LCD TV's become damaged when held under the same image for a long time?

Answer 1

http://en.wikipedia.org/wiki/Image_persistence

LCD's are actually better about still pictures than most conventional picture tube sets or plasmas, but the effect is called image persistence in LCD sets. While it is similar to the burn in that happens with picture tubes and plasma sets, it is usually not permanent. See the link above for more details.

Answer 2

they dont plasma burn in the image