What a nightmare. Back when a decent-sized flat panel could set you back $10k or more, many a proud owner dreaded the day when he would come home and find the words “Now Playing” or some similar menu etched indelibly into his expensive TV, sitting there like a ghost over every image.
It’s technically called “image retention” or if temporary, “image persistence” but most folks call it burn-in. It used to be a big problem on CRT and older plasma screens, and was caused whenever you left the TV tuned to a specific channel or menu for a long period of time. The screen ages differently depending on the image that is displayed, and if the same image is displayed for a long time then burn-in is a real possibility.
Today, cases of burn-in are rare. Most people think that burn-in isn’t a problem with LCD screens, and it isn’t except in very extreme circumstances. In cases where a menu is left up for months at a time, such as on computer screens, image persistence can still happen. In fact, it doesn’t take more than a few hours to start seeing a persistence pattern on something like an iPad.
The good news is that in most cases it’s not permanent. In the case of LCD panels, the issue is not uneven aging so much as a tendency for the voltage pathways to become temporarily “lazy.” In other words they carry a little more voltage because they have carried the same voltage for such a long time.
In a case where you see some image persistence on an LCD screen, it usually doesn’t take more than a few hours spent on a different channel (or using a different app) to fix matters automatically. If persistence is a little more, well, persistent, there are web sites and apps that will fill the screen with rapid flashes and motion for several hours and that should be all it takes to get rid of any persistence artifacts.