When utilizing LCD monitors in applications where a fixed or semi-fixed image remains displayed on the screen for extended periods of time, users may experience a phenomenon referred to by the LCD industry as Image Persistence.
Image persistence in LCD panels is often known as «image retention», «burn-in» or «image sticking».
As an example, the following images show the persistence on Samsung S27A850D monitor after 15 minutes, 30 minutes and 1 hour of displaying the static image of checkerboard:
As can be seen from this example, the contrast of image persistence increases over time.
In either case, when the liquid crystals in the pixels and sub-pixels utilized to display the static image are polarized such that they can not return fully to their «relaxed» state upon deactivation, the result is a faint, visible, retained image on the LCD panel upon presentation of a new, different image.
Even when the LCD monitor is turned off, small electrical charges in the pixels force them to be in an «on» state for a long period of time.
Image persistence may be temporary or permanent. In most instances, this does not permanently damage the screen and can be easily reversed or prevented. Unfortunately, in some rare cases it may not be reversible.
Image persistence is not a product defect, and all LCD products are subject to image persistence. Even such high-quality products like Apple displays.
Image persistence, image retention, burn-in and image sticking are explicitly not covered under the manufacturer's warranty as these issues are risks inherent to the LCD display technology itself. Therefore, some monitor manufacturers recommend reducing the display time of any static image to 30 minutes.
You cannot avoid image persistence because you will always have unused areas of the screen. This is the general problem for all monitors, especially widescreen ones. Here is an example of screen usage during web surfing (including watching videos on YouTube) for several hours. The example show continuous duration of use of screen pixels is only 54 minutes (red pixels).
According to statistics, the longer you work with the computer, the more there is image persistence on the screen of your monitor. The following example show image persistence from the Windows desktop:
The image persistence itself does not harm the screen of a working monitor (if of course it does not work 24/7/365). That is why after you have watched a movie on your computer the image persistence may disappear but may actually become bigger. The damage happens if you switch off the computer or turn off the monitor to save energy.
Image persistence in a shut down monitor makes the liquid crystals stay turned on for a long time (for example, during one day). Switching off your monitor in such condition, you may irretrievably damage it because such environment characteristics as temperature and humidity make parts of the screen monitor loose their homogeneity.
Also it is not recommended to use screensavers because on different monitors (IPS, TN, etc.) they may increase image persistence due to their content.
In order to avoid damages of and to correct already damaged (on the initial stage) monitors GRG Software Company created a program PerfectScreen. The program is suited for both home users and companies.
The program works in a few steps. While the user is working on the computer, the program collects real time image persistence statistics. As soon as the user stops working, the program removes the accumulated image persistence based on the collected statistical data. After all image persistence is completely removed, algorithms of normalization of monitor screen are being turned on. Straight after the user re-commences his work, the program goes back to stage one.
In order to check whether your LCD monitor has image persistence and loss of screen homogeneity you need to open Paint program for ¼ of the screen without any additional light (preferably in the evening), paint it in 25% gray color and with the help of the mouse move it around on the screen in different directions.
Also you can try to explore the monitor with the help of PerfectScreen.
If you already have some form of image persistence on your LCD monitor, try to leave the computer with PerfectScreen running for 12-24 hours to reduce or remove the image persistence.