I had an area of dead pixels on my Lenovo laptop, which appeared out of nowhere and grew over time. The area was completely black - couldn't see through it, and after recent travel with laptop - I noticed that area turned green, and I can see black and other darker colours through it. Could it have magically partially healed by airport scan? or any other causes?
LCD = Liquid crystal Display. http://en.wikipedia.org/wiki/LCD
Some issues with LCD display can be the Liquid itself. The sun beating down on it, pressure differences , just things that would effect the liquid in them.
If you have ever heard of the "Rubbing" a bad pixel out , it was all about moving the liquid around to try and get it working again. It does not work for pixels that are "dead" electronically but it may change things for pixels that are "dry".
All the ways that liquids could have moved in your travels, could be what changed the . . . liquid.