Screens with emitting phosphors can be damaged by the continuous electron bombardment during longer, constant displays. This effect, known as burn-in, reduces the luminosity of the phosphors and shows up in other displays in that the pixels in question glow somewhat darker.
The burn-in effect occurs with cathode ray tubes and plasma displays, and is more pronounced the longer the screen is used with the same mask. This can be seen in the darker screen parts of constantly used masks, which burn into the phosphor of the screen and decrease in luminosity.
To prevent screen masks from burning into the phosphor as much as possible, if there is no keyboard input for a certain period of time, the screen switches to a save mode to prevent further burning of the used work mask. As soon as any keyboard input or mouse movement is performed, the operating system switches to the desktop.
Instead of the work mask, there is a graphical representation that is statistically moved across the screen so that all phosphor particles are equally exposed. These graphic representations moving across the screen are called screensavers. They can be selected and set in the control panel.
Screen savers can also be used for advertising. The advertising banners can be updated online and the display time can be transmitted to the advertising server for the calculation of the advertising performance. The screensaver advertising has a high attention value.