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Screen savers were initially intended to keep CRT monitors from burning images into the screen. Now there are other reasons to continue to use them.

I have LCD monitor. Do I need to use screensaver? Do you recommend that I do or don't?

Let's put it this way: I do.

In fact, I use a couple of specific settings related to that, and very much on purpose.

Let me tell you why.

Old "CRT" monitors (the ones based on big glass picture tubes that look like old TVs) were subject to something called "burn in". If a picture was displayed on the screen for too long a ghost of that image would become permanently burned into the screen itself. You could turn the monitor completely off, and still see a vague, faint image that matched what was displayed on the screen. You used to see this on cash registers, ATM machines or other single-purpose devices where the screen typically had exactly one unchanging image on it 99% of the time.

Thus "screen savers" were born. These programs would fire up after some period of inactivity when presumably no one was using the display. They would remove that image that was displayed 99% of the time and replace it, typically with other images, or in the case of desktop computers, animations like flying toasters, pipes or lately even fish-tank simulations.

"If a picture was displayed on the screen for too long a ghost of that image would become permanently burned into the screen itself."

With an always-changing image on the screen, burn-in was significantly reduced or eliminated.

LCDs naturally use a different technology for display - they don't have the glass surface on which the image can be unintentionally burned into. But that doesn't mean that they aren't susceptible to something similar. Now, I'll be totally honest here and say that, quite frankly, I don't know just how serious a burn-in problem exists with LCD screens (I suspect a more knowledgeable reader or two will chime in, in the comments). What I can tell you is that I have seen ghosting on my LCD screens when I move a window that's been in one place too long. Is that a permanent problem? I'm not sure. It could also easily be attributed to the quality of my monitors, perhaps. But I see it.

So it leads me to this position: screen savers don't hurt, and if there is risk - no matter how small - then they can help.

So, yes, I do recommend running a screen saver, regardless of your monitor type.

But wait, as they say, there's more!

  • Particularly if you're in an environment where people can walk by while you're away from your computer, you need to make sure to enable the option that requires a password to get out of the screen saver. That way people can't easily access your computer while you're not around.

  • I prefer the "blank" screen saver. Unless there's some reason you specifically want to see something, just have the monitor go black. It saves a tiny bit of power, it doesn't visually distract if you happen to be around but not using the computer, and it doesn't advertise the fact that your computer is running if you're not around.

  • Speaking of power, make sure to select the power options now available on many systems that will actually turn the monitor off if you're away long enough. This option actually removes power from most of the display circuitry in the device completely, which reduces power consumption dramatically. The net effect is a blank screen, of course. And it behaves much like a screen saver when you return, except that it might take a few additional seconds to warm up and return to a fully "on" condition.

Yes, I know, I like fish tanks and flying toasters as much as the next guy, but in all honesty, I think that a little energy saving is perhaps a slightly more important priority.

But ultimately, yes, use a screen saver. There's almost no reason not to.

Article C3498 - September 11, 2008 « »

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Leo Leo A. Notenboom has been playing with computers since he was required to take a programming class in 1976. An 18 year career as a programmer at Microsoft soon followed. After "retiring" in 2001, Leo started Ask Leo! in 2003 as a place for answers to common computer and technical questions. More about Leo.

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10 Comments
Ken B
September 12, 2008 7:08 AM

I understand that part of the way the LCD monitors work is that they have a light source behind the screen. (Which is why you can see it in a dark room -- it's an active source, not passively reflecting room light.) This light source has a limited lifetime, and using the "power save" mode of a screensaver turns off the backlight, thereby increasing the lifetime of the monitor.

http://computer.howstuffworks.com/monitor5.htm

David Ball
September 12, 2008 9:46 AM

A couple of quote notes for consideration:
1) As you surmised, LCDs do not suffer from permanent burn-in. However, there is a technology that does: Plasma screens. I recall in the late 80ís, when monochrome plasma screens were an incredibly expensive upgrade on IBMís commercial systems, the challenge with burnt monitors was overcome with self-power down routines.

2) The cost for using a screen saver with an LCD is the lifetime of the backlight. LCDs are illuminated (principally) by cold cathode fluorescent lamps. This tubes have a limited lifespan and are often costly to replace. In the case of some notebook computers, the entire screen must be replaced (as it is more costly for the labor to only replace the lamps). I discovered this first-hand with my wifeís old Sony notebook. Some of the newest (and more expensive) LCDs are using LEDs as their light source, which should provide many advantages including longer lifespan.

Jason Zions
September 12, 2008 3:28 PM

Running a screen saver may prevent your computer from detecting that it's idle and going into a lower-power state (suspend). Well-written screen savers tell Windows that, even though they're running and doing something, they're really doing nothing important and the computer can suspend.

The problem is that badly written screen savers don't do that, and they're sometimes insecure, and they're sometimes vectors for attacks on your computer. Running the screen savers that come with Windows is safe in these respects; some commercial and some free screen savers are fine; some are, let's say, a bit dodgy.

The best advice is Leo's; run the "Blank Screen" screensaver and select "Require a password when exiting the screen saver". Oh, and try turning the monitor off with the power switch when you know you're going to be gone a while. :-)

Russ
September 12, 2008 7:19 PM

If you run a distributed computing project in the background like SETI, or Mersenne Primes, or World Community Grid then I recommend the blank screen saver as it doesn't use any cycles leaving that many more for your background project. It might help you find the cure for AIDS!

Michael Horowitz
September 15, 2008 7:17 PM

I turn off the screen saver and set the power options in the control panel to turn off the monitor after a while. Steve Gibson's little Wizmo utility can be used to be a computer into sleep mode immediately, great if you know you are stepping away briefly.

Alfred Poor
September 16, 2008 5:47 AM

LCDs are not susceptible to burn in. (It's the phosphors in a CRT that wear out, not the glass, and LCDs do not use phosphors.) So there's no need to use a screen saver. In fact, as others have pointed out, using a screen saver will actually waste energy and shorten the display's lifetime because the backlight stays on whether the screen is showing a white or black image. The best strategy is to use the energy-saving settings to put the display in sleep mode as quickly as possible when you're not using it.

Alfred Poor
HDTV Almanac
www.hdtvprofessor.com/HDTVAlmanac

Harish
September 18, 2008 7:57 AM

Thanks for the good answer to a "usual" question. What I like most is the way you emphasize on power saving feature of blank screen, though not too much, yet a combined effort by people can make a big difference...

Harish

Tom
June 28, 2011 9:26 AM

24 inch LCD monitors are down to $139.00 (AOC brand @ Tiger Direct). If I get a year out of it that's fine. 30 inch should be rock bottom by then and I can upgrade. So who worries about burn in! As long as I get bye infant mortality I'm happy.

Mike
June 28, 2011 11:05 AM

As a video/TV engineer for nearly 40 years, I concur with most of the comments, but with a few modifications.

CRTs were extremely susceptible to burn-in due to the phosphors becoming exactly that: burned in the image left on them. Nothing could undo the effect, though much was tried.

LCD's (including DLP, a specialized type of LCD) are not SO susceptible since they do not use phosphors. However, liquid crystals work by twisting to allow more or less backlight through, and are measured for response time in providing video definition. Leaving an image on for too long will cause the response time to slow way down. Eventually, any "burn-in" will fade, but LCD pixels can still be damaged.

Concerning the backlight technology of LCD's, monitors (TV's) 42" and smaller use a permanent built-in light source that is not user-replaceable. 46" and larger require a brighter lamp module that does eventually burn out and need to be replaced. In neither case do they have any substantial effect on burn-in.

Plasma, definitely subject to burn in and, like CRTs, not much can be done to reverse it.

Sean
November 2, 2011 4:53 PM

I use lcd led on my mac and i haven't had burn in but i'm runing at 2560 by 1440 resolution that beats crt on dot pitch and burn in and my plasma screen does burn in worse then a crt but i leave it on with a screen saver and it washes it away very quickly

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