LCD Image Persistence

One of the problems with old CRT monitors, over time, was a condition called burn-in. This phenomenon resulted in an imprint of an image onto the display that was permanent, caused by the continuous display of a particular picture on the screen for extended periods. A breakdown in phosphors on the CRT results in the image being burned into the screen, hence the term. Is there such a thing as LCD screen burn-in?

What Is Image Persistence?

LCD monitors use a different method for producing the image on the screen and are immune to this burn-in effect. Rather than phosphors generating light and color, an LCD uses a white light behind the screen with polarizers and crystals to filter the light to specific colors. While LCDs are not susceptible to burn-in the same way CRT monitors are, LCDs suffer from what manufacturers call image persistence.

Like the burn-in on CRTs, image persistence on LCD monitors is caused by the continuous display of static graphics on the screen for extended periods. Long-term-static images prompt the LCD crystals to develop a memory for their location to generate the colors of that graphic. When a different color appears in that location, the color will be off and will display a faint image of what was previously displayed.

The persistence is the result of how the crystals in the display work. The crystals move from a position allowing all light through to one that doesn't allow any. It's almost like a shutter on a window. When the screen displays an image for an extremely long time, the crystals can switch to a particular position. It may shift a bit to alter the color, but not completely, resulting in a display other than the one intended.

This problem is most common for elements of the display that do not change. Items that are likely to generate a persistent image are the taskbar, desktop icons, and background images. These tend to be static in their location and displayed on the screen for an extended period. Once other graphics load over these locations, it might be possible to see a faint outline or image of the previous graphic.

Is It Permanent?

In most cases, no. The crystals have a natural state and could shift depending on the amount of current used to generate the desired color. As long as these colors change periodically, the crystals at that pixel should fluctuate enough, so the image doesn't imprint into the crystals permanently. However, if the screen is always on the image that doesn't change, the crystals could obtain a permanent memory.

Can It Be Prevented or Corrected?

Image persistence on LCD screens can be corrected in most cases and easily prevented.

1. Set the screen to turn off after a few minutes of idle time. Turning off the monitor display prevents images from appearing for extended periods. Setting the monitor to do this when the computer is idle for 15 to 30 minutes can make a difference. These values appear in the Mac Energy Saver settings or Windows Power Management.

2. Use a Windows screen saver or Mac screen saver that rotates, has moving graphics, or is blank.

3. Rotate any background images on the desktop. Background images are a common cause of image persistence. By switching backgrounds every day or every few days, you'll reduce the risk of persistence.

4. Turn off the monitor when the system is not in use.

Correcting Image Persistence

Using these items can prevent the image persistence problem from cropping up on a monitor. If the monitor displays image persistence problems, here are a few steps that can be used to correct it:

1. Turn off the monitor for extended periods.

2. Use a screen saver with a rotating image and run it for an extended period. The rotating color palette should remove the persistent image. Still, it could take a while to remove it.

3. Run the screen with a single solid color or bright white for an extended time to force the crystals to reset at a single color setting.