LCD Image Persistence

Can burn-in happen to LCD monitors?

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. You might see it, particularly in old arcade-game cabinets. It was caused by the continuous display of a particular image on the screen for extended periods of time. This would cause a breakdown in the phosphors on the CRT and would result in the image being burned into the screen, hence the term.

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

What Is Image Persistence?

Persistent or Burned In Image on an LCD TV
Wikimedia Commons

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 of time. Long-term-static images prompt the LCD crystals to develop a "memory" for their location in order to generate the colors of that graphic. When a different color is then displayed in that location, the color will be off from what it should be and instead display a faint image of what was previously displayed.

The persistence is the result of how the crystals in the display work. Essentially, the crystals move from a position that allows all light to go through to another that allows none through. It's almost like a shutter on a window. When the screen displays an image for an extremely long time, the crystals can want to switch in a certain position, similar to a window shutter. It may shift a bit to alter the color, but not completely, resulting in it displaying a result that's other than what was intended.

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

Is It Permanent?

In most cases, no. The crystals do have a natural state and can shift depending on the amount of current used to generate the desired color. As long as these colors do shift periodically, the crystals at that pixel should fluctuate enough such that the image will not be permanently imprinted into the crystals. Having said that, it is possible that the crystals could get a permanent memory if the screen image does not change at all and the screen is left on all the time.

Can It Be Prevented or Corrected?

Image persistence on LCD screens can be corrected in most cases and is easily prevented. Prevention of image persistence can be done through some of the following methods:

  1. Set the screen to turn off after a few minutes of screen idle time under the display and screen preferences in the operating system. Turning the monitor display off will prevent an image from being displayed on the screen for extended periods of time. Of course, this could be annoying to some people as the screen may go off more than they wish. Even setting it to do this when idle for 15 to 30 minutes can make a huge difference. These values appear in the Mac Energy Saver settings or Windows Power Management.

  2. Use a screen saver that either rotates, has moving graphics images, or is blank.

  3. Rotate any background images on the desktop. Background images are one of the most common causes 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 help prevent the image persistence problem from cropping up on a monitor. But what if the monitor is already displaying some image persistence problems? Here are a few steps that can be used to correct it:

  1. Turn off the monitor for extended periods of time.

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

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