<P> In the case of LCDs, the mechanics of burn - in are different than plasma and OLED, which develop burn - in from luminance degradation of the light - emitting pixels . For LCDs, burn - in develops in some cases because pixels permanently lose their ability to return to their relaxed state after a continued static use profile . In most typical usage profiles, this image persistence in LCD is only transient . </P> <P> Both plasma - type and LCD - type displays exhibit a similar phenomenon called transient image persistence, which is similar to screen burn but is not permanent . In the case of plasma - type displays, transient image persistence is caused by charge build - up in the pixel cells (not cumulative luminance degradation as with burn - in), which can be seen sometimes when a bright image that was set against a dark background is replaced by a dark background only; this image retention is usually released once a typical - brightness image is displayed and does not inhibit the display's typical viewing image quality . </P> <P> Screensavers derive their name from their original purpose, which was an active method of attempting to stave off screen burn . By ensuring that no pixel or group of pixels was left displaying a static image for extended periods of time, phosphor luminosity was preserved . Modern screensavers can turn off the screen when not in use . </P> <P> In many cases, the use of a screensaver is impractical . Most plasma - type display manufacturers include methods for reducing the rate of burn - in by moving the image slightly, which does not eliminate screen burn, but can soften the edges of any ghost image that does develop . Similar techniques exist for modern OLED displays . For example, manufacturers of Android Wear watches with OLED displays can request that Android Wear enable "burn protection techniques" that periodically shift the contents of the screen by a few pixels . </P>

What does burn image mean on a phone