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Do Later LCDs Need Screen Savers?
bwdunn asks: "Do we need to run screen savers again to prevent the burn-in we saw on the very old CRTs? Dell's latest and greatest laptops, the Latitude D800 and Inspiron 8500 both suffer from horrible screen burn-in problems with burn-in visible after as little as 2 hours. Dell claims this is an industry wide problem. The high end displays from Apple also seem to have this problem. I have never seen this problem before 2002. Is this something new due to inferior LCD screen manufacturing compared to screens from just a few years ago?"
The toasters are going to fly again, gentlemen...
Sounds crazy to me. Got three LCD panels at work that basically sit around displaying the same thing for 12 hrs a day (when we are not there).. I wasn't aware that it was -possible- for an LCD to burn...
"Champagne for my real friends - and real pain for my sham friends!" http://ericblade.postalboard.com/
The local department has recently been replacing the CRT displays in the computing labs with LCDs as part of their rolling upgrade cycle. So that it's easier to distinguish between a working PC and a dead one by whether or not the login screen is showing, we turned off the screensaver -- thinking that ``there's no phosphor to get burned in.''.
Doesn't appear to be true, sadly. A number of displays are now starting to get a burnt-in image of the login window.
Time to update the login manager scripts with a small call to xscreensaver, methinks..
The answer (at least for Dell) is in the forums that were linked to in the summary. Send it back. Get a new one. If the new one also burns in, do it again. Do it until you get an LCD that doesn't burn in. It's a major hassle, but it appears that all of their LCDs don't suffer from this problem, thus it's unlikely that "new" LCDs have this problem. Looks like a bad batch or poor construction somewhere in the laptop/LCD, since replacing the LCD will eventually get rid of the problem.
I don't know about you guys, but I was never a fan of wasting power. All my PCs turn off the monitor when idle!
Do you drive an SUV too?
Here. Picture after 15 hours of burn-in and 51 hours of uninterupted reconditioning.
Lars T.
To the guy who modded me down from perfect to terrible Karma - Apple haters still suck
Iâ(TM)ve had five Dell C810 Latitude laptop screens (over three machines) that all exhibited this ghosting problem. Kits from work, so they were under warranty. No problems with any of the thinkpads or the Dell Precision M50 (?), so Iâ(TM)m willing to bet Dell cut some corners on the Latitude series.
Industry problem my assâ¦
+++ UGUCAUCGUAUUUCU
I bought a Dell Inspiron 5000E about three years ago (they are no longer made) with the expensive 1600x1200 LCD display.
Luckily, it doesnt have this problem. Ive used it every day for three years and not had any burn-in. None. Zero. Zip.
Another reason I'm glad my LCD doesn't have this problem is this: the energy saver just turns off the backlight. I can shine a bright flashlight on the display and see that the liquid crystals are actually still displaying the screen. Once I even moved the mouse pointer around while the backlight was off, and I could see it with the flashlight. (There is a button which turns off the backlight. It is positioned so that shutting the lid pushes it.)
Some screen savers also have a tendency to use the same areas of the screen, so watch out. "Blank Screen" is probably best because it really does set all the pixels to black, whether the backlight is on or not.
I wonder whether it is black or white which causes the pixels to "fade."
Sunlit World Scheme. Weird and different.
Well, I was going to post a reply to the effect of "aren't those fluorescent, so they waste energy turning them off and on," but it turns out I was wrong about that and this site has a very good explanation of why that used to be true but isn't any more.
"I assumed blithely that there were no elves out there in the darkness"
I have two flat-panels on my desk at work, one of which is a Dell that I've had for about a year. I've never had a problem with burn-in on them, but:
(1) I've set up my screensaver to power off the screen after 5 minutes of inactivity.
(2) I press the power button to turn the screen completely *OFF* when stepping away from my desk - even if it's only for an hour at lunch.
These strange manual power-saving methods of pressing a switch.. it's strange, I tells ya.
From the Apple LCD FAQ :
... is that somehow also burning it in a different direction, possibly also causing damage? I would think not, but I thought that LCDs were immune to the effect in the first place.
3.1 - Q. I have noticed that my screen is showing some burn in when left with the same image for a long period of time. I thought LCDs were immune to 'burn in'. What should I do?
A. In the event of a mild or even strong burn in, unplug your LCD, lift it off the table and orient it with the screen down, parallel to the Earth. Now shake it all around. The silver powder in the unit will spread all around, returning your display to the original condition. When putting the display back on your desk remember that the two knobs go on the bottom.
-:-
Oh wait, that was from my Etch-a-Sketch.
That said, I read what Apple has to say on the matter and now I wonder - why are LCDs 'burning in' in the first place, and by blasting it with a bright white image to restore the screen
Glonoinha the MebiByte Slayer
What with a new $80 shipping and handling charge for warranty repairs.
"Eve of Destruction", it's not just for old hippies anymore...
Sounds crazy to me. Got three LCD panels at work that basically sit around displaying the same thing for 12 hrs a day
You sure they're not just burnt in?
Actually it can be done either way. A liquid crystal, when powered, rotates the polarization of light 90 degrees. When unpowered it has no effect. So, a LCD display is made from two polarizers and a layer of liquid crystals. Consider this:
Whether white or black is powered depends on the way the display is made.
Sunlit World Scheme. Weird and different.
You'll be so busy compiling stuff.... not one thing will be displayed on that screen constantly!
Kills burn-ins too...
---The Gentoo Troll
-- ;-)
Kuro5hin.org: where the good times never end.
What most people ignore are the facts that once you touch an LCD screen is that it really can't get cleaned right. People sneeze on the screen and touch the screen and on laptops, keys will etch into the screen. What we NEED is a clear, thin plastic screen to go over the LCD to prevent things like dumbass girlfriends getting their fingerprints all over my nice 15 inch laptop screen.
- Zav - Imagine a Beowulf cluster of insensitive clods...
I don't have a problem with burn-in- but I use the screen saver- more important is to shut off your backlight- they have a limited lifetime, and will lose intensity over time.
CUT CORNERS? Are you joking me? The Dell Latitude series has been a joke to me for years. While I haven't used any of their more recent machines (about 2 years), I can safely say that there is absolutely no justification for the Latitude's inflated price.
They are not durable, they don't perform well compared to the competition, are poorly built, and (with a few exceptions) weigh a ton. While Dell's Inspiron line isn't exactly great, they're priced accordingly.
The high-end notebooks from other companies, however, such as the IBM thikpad do indeed show improved quality which reflects their high(er) price. If you've ever used or felt one, you can see that they are very sturdily built.
When all else fails, you could always get an iBook. Cheap,
and well-built to boot.
-- If you try to fail and succeed, which have you done? - Uli's moose
and make sure to pick a design you can live with for the duration ... on this note, why not use your name? That laptop will always be traceable no matter how far it walks or runs ....
Laptop Rule One: Laptops have legs and will run away as soon as you turn your back on one. especially once you've given it a lot of data.
Words to men, as air to birds.
Many household devices today use more power when their state is changed than they would if they were just left on constantly.
Go get yourself a meter like the WattsUp and gather some stats. In my experience, for computers there is an initial power surge that is maybe 2-3x normal draw, and lasts anywhere from 20 seconds to a couple of minutes. So worst case, if you will be turning your computer on again within 6 minutes, you probably should leave it on. Otherwise, turning it off will save power.
For screens, it's more complicated; CRTs draw more while warming up, but only for 15 seconds or so. But they draw less when showing a fully black screen, and different resolutions draw different amounts. Also, modern CRTs have assorted sleep modes. So whether or not to turn off a CRT depends on your usage patterns. For LCDs, I have no data.
I was also interested to note that high CPU usage produces measurable extra power usage. On a dual-processor P3/733 system, each processor pulls an extra 10 watts under load. So it turns out that things like SetiAtHome aren't free.
My mother, for instance, wastes more power than she saves by going around turning off all her fluorescent lights.
A common misconception, but not true. See this article for the details. They recommend leaving them on if you'll need them again within 15 minutes. But this isn't because of power usage; it's because turning them off and on too often reduces bulb life.
Aren't LCD monitors designed in the same way? They only use power when they are updated?
You'll note that in a dark room, you can see the LCD just fine. This means that it's producing light, which takes power. According to this week's Economist, "an LCD is only 10-15% efficient at converting energy from its power source into a readable image."
The Dell Latitudes are not marketed to people who want high performance machines. They're marketed to people who want to be certain that if they order multiple machines with identical specifications they'll get multiple identical machines. Not only will you get several identical machines if you order them all at once (which is much more unusual than you may realize), but you'll also be able get identical machines if you order them again three months later (which is a much more common requirement than you may realize). And, you'll still have identical machines after the various warranty replacements you'll inevitably have over the next three years.
If you don't get any value from having multiple identical machines, then you don't want to buy Dell Latitudes. They don't offer anything of value to you. But don't act as if that means they don't offer anything of value to anyone.
Slashdot is jumping the shark. I'm just driving the boat.
that makes sense because the way an LCD monitor works is using pixels to block off the backlight.
So whereas on a CRT, an "activated" pixel corresponds to a bright spot (it's where electrons are hitting the screen and making it fluoresce), on an LCD activating the pixel makes the area dark. Each pixel is transparent until an electric field is applied to line up the liquid crystals. This polarises the light coming through and depending on the degree of polarisation, the transmitted light is blocked by a cross-polarised layer on the screen.
Presumably "burn-in" occurs when the LCD fails to completely return to its non-polarising state. I'd guess this is because the screen builds up some electric charge in those areas, like a capacitor.
If that's correct, then all that's needed is a "degauss"-type function on the screen that neutralises any built-up charges.
The author of this post asserts his moral rights.
One of the big drawbacks of LCD's is that the backlight has a fairly limited life. Usually 3-6 thousand hours. You shouldn't be using a screen saver, since the backlight is still on. You should use something that just shuts your screen off after X minutes.
:). I never used them. I just used a screen blanker, even with the old CRT's.
I never did understand screensavers...sure they keep burn in down, but your still displaying something on your screen, which does cause some burn in (just let it show the screen saver for 20 years!