Your sentence was not added because the following already exists.
LCD = liquid-crystal display. The word “display” is already part of the abbreviation, so I suppose it should be just “LCDs”.
This is an example of "RAS syndrome" ("redundant abbreviation syndrome syndrome") and in fact is mentioned explicitly on this page:
https://en.wikipedia.org/wiki/RAS_syndrome
I would argue that "LCD" has become a term in itself, and people no longer analyze the constituent words. Furthermore, one might think of an "LCD" as a display element, even though that's not the original meaning of the phrase. For those reasons, and because "LCD displays" is so common in writing as well as speech, I'm going to mark the existing sentence OK.
