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A computer program that was originally designed to prevent the burn-in of phosphor on plasma computer and CRT monitors is known as a screen saver. A screen saver functions by filling or blanking the screen with patterns or moving images when a computer is not in use. The contemporary types are mainly used for security or entertainment.
There are many benefits of screen savers as seen at screensavergold.com but Prior to onset of LCD screens, the majority of computer screens were based on CRT, typically referred to as cathode ray tubes. When a CRT screen has an image displayed on it for long periods of time, the exposed areas properties of phosphor coating from the screens inside experiences both gradual and permanent changes and eventually results in a “ghost” image which is a darkened shadow on the screen.
This can be avoided with screen saver programs, which were designed to automatically change the images on a screen during times of user inactivity. With CRT used in the public realm such as railway ticketing machines and ATMs, burn-in risk is particularly high because the stand-by display appears whenever the machine is not being used.
There is less risk of burn-in with modern CRTs due to advances phosphor coatings in addition the current computer images being typically lower contrast that the white-on-black text or stark green and the graphics that were prevalent in earlier machines. The LCD computer monitors are not at risk to burn-in because the phosphors do not directly produce the image, and this includes display panels that are used in laptop computers.