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Displays

Do Later LCDs Need Screen Savers? 223

Posted by Cliff from the two-steps-backward? dept.
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?"
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Do Later LCDs Need Screen Savers? More

Do Later LCDs Need Screen Savers?

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  • what can save us from burn-in? (Score:5, Funny)

    by kurosawdust ( 654754 ) on Sunday June 22, 2003 @04:59PM (#6268885)
    The toasters are going to fly again, gentlemen...

  • sounds crazy (Score:4, Interesting)

    by XO ( 250276 ) <blade,eric&gmail,com> on Sunday June 22, 2003 @05:13PM (#6268947) Homepage Journal
    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...

    • Ummm... (Score:5, Funny)

      by Anonymous Coward on Sunday June 22, 2003 @07:58PM (#6269935)
      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?
      • Pretty sure they are ok, since they look totally normal when I am using them during the day.. like right now...

    • Re:sounds crazy (Score:4, Interesting)

      by eht ( 8912 ) on Sunday June 22, 2003 @08:55PM (#6270205)
      I haven't seen it in a monitor yet, but I've noticed many ATM LCD screens are burned.

      I've also seen some newer ATMs have screen saver thingies that flash around the banks promos and options which I assume is to reduce burn, but could just be intended to be cheap advertising.
    • we have Dell LCD's here, and they do burn in... it's *very* irritating. a reboot has fixed it, up to now...
  • 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 is in the fourms... (Score:5, Informative)

    by Sancho ( 17056 ) on Sunday June 22, 2003 @05:14PM (#6268952) Homepage
    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.

  • Ick! Screensavers!? (Score:5, Insightful)

    by WWWAvenger ( 625119 ) on Sunday June 22, 2003 @05:16PM (#6268967)
    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?

    • Re:Ick! Screensavers!? (Score:5, Funny)

      by SN74S181 ( 581549 ) on Sunday June 22, 2003 @05:21PM (#6268991)
      It's rumored that some people actually turn off the whole computer when they're not using it.

      The Uptime Fashion Police are working on a rigorous ostricization program, however. It's just not cool to turn one's PC off, and it defeats the main purpose of running Linux.
    • That might not always be the best route. Many household devices today use more power when their state is changed than they would if they were just left on constantly.

      My mother, for instance, wastes more power than she saves by going around turning off all her fluorescent lights. Aren't LCD monitors designed in the same way? They only use power when they are updated?

      • Re:Turning monitor off (Score:5, Informative)

        by sigwinch ( 115375 ) on Sunday June 22, 2003 @08:26PM (#6270071) Homepage
        Many household devices today use more power when their state is changed than they would if they were just left on constantly.
        Wrong. The turn-on surge for all common household devices is a few times normal power, and only lasts for a fraction of a second. The energy cost of the surge is negligible.

      • Re:Turning monitor off (Score:5, Interesting)

        by dubl-u ( 51156 ) * <2523987012@pota . t o> on Sunday June 22, 2003 @11:31PM (#6270777)
        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 [doubleed.com] 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 [lightingdesignlab.com] 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."
        • 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.

          This is because rathering then executing self: jmp $self in the idle loop, the operating system typically uses the HLT instruction which puts the CPU into a low power (unclocked) state until an interrupt is received (typically the timer interrupt, meaning the scheduler needs to
        • 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.

          My workstation starts up with both fans running full power, then when the OS comes on line and realizes it has only one CPU (out of potential 2) and one graphics board (out of a potential 3) it switches the fans down to half speed (it may even switch one of them off altogether).

          On higher end machines, the OS support getting actual fan rpm with a syscall
        • 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.

          While I have no data on LCDs, the key elements are the panel itself (which requires power to be set in an opaque mode, transparent shouldn't draw any) and one or more fluorescent lights. The lights are a big energy draw from my experience, which is why laptops have a brightness setting, and turn the screen off fairly quickly in power-saving modes. I typically get 1.5
        • > I was also interested to note that high CPU usage produces measurable extra power usage

          He! I had a good example of that a couple weeks ago. I built a cluster [gdargaud.net] of 12 PCs with 2 AMD Athlon 2400+ each, running OpenMosix. I had tested it in small chunks so I knew it could run. I moved everything over to the final destination, a 3000VA UPS, and invited my boss to come throw the switch.

          It started perfectly and I started demonstrating the power of 30Gflops of AMD CPU working together: I started a script to r

    • I was never a fan of wasting power. All my PCs turn off the monitor when idle!

      If the monitor is an LCD screen, it very well may be powered by a wall-wart or brick type transformer. Even when turned off, there is some power draw. Just how many watts does an LCD display transformer draw anyway? (I don't actually know.) 20 watts? 40 watts? And how much is this vs. a CRT?

      When an LCD turns off it's backlight, or goes into "sleep" mode, how much power does it draw? If it were a tiny amount, like a
  • Here. [heise.de] Picture after 15 hours of burn-in and 51 hours of uninterupted reconditioning.
    • Strange, it looks like the shadows on the windows and text are where the burn-in occured.

      If that's the case, then dark screensavers would not actually help as I previously thought.

      • Re:Black pixels causing the burn-in? (Score:4, Interesting)

        by misterpies ( 632880 ) on Monday June 23, 2003 @07:03AM (#6271977)
        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.
  • 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¦

    • Re:Dell C810 – Sometimes you are only a warning. (Score:4, Interesting)

      by moosesocks ( 264553 ) on Sunday June 22, 2003 @09:28PM (#6270349) Homepage
      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.

      • Re:Dell C810 – Sometimes you are only a warning. (Score:5, Interesting)

        by bellings ( 137948 ) on Monday June 23, 2003 @12:11AM (#6270936)
        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.

  • Turning Off Screen (Score:5, Interesting)

    by Sunlighter ( 177996 ) on Sunday June 22, 2003 @05:35PM (#6269088)

    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."

    • I don't see what causes the LCD's pixels to get "burnt in". If you look at how they work [howstuffworks.com], it's just alligning the liquid crystal. The only possibility I can think of is the crystals getting stuck in position. I think it's just cheap displays. This is not the same as the burn in that actually happens to LCD projectors like seen on a previouse slashdot article (can't find, search engine is worthless). On the projectors, they have extremely bright lights with lots of heat and UV. The heat and UV breaks down th

  • POWER BUTTON vs Laziness (Score:4, Insightful)

    by Anonymous Coward on Sunday June 22, 2003 @06:29PM (#6269436)
    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.
    • For some LCD screens it's enough just to let the screen go to standby/suspend mode, pressing the on/off won't really benefit that much. For example, my LG Flatron 1810B [lge.com] is specified as consuming "less than 3W" of energy when in suspend or standby, and the same "less than 3W" when turned off(!). I haven't measured the consumption, though.

  • Not totally burned in. (Score:3, Informative)

    by norwoodites ( 226775 ) <pinskia@ g m a il.com> on Sunday June 22, 2003 @07:31PM (#6269782) Journal
    If the had read the til from apple, they would not have said it is burned in because it really is a temparory problem that can be fixed according to the atricle.

    • Cut and paste from the docs ... (Score:5, Funny)

      by Glonoinha ( 587375 ) on Sunday June 22, 2003 @07:55PM (#6269912) Journal
      From the Apple LCD FAQ :

      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 ... 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.

  • Yet another reason to run gentoo! (Score:5, Funny)

    by Anonymous Coward on Sunday June 22, 2003 @08:25PM (#6270063)
    You'll be so busy compiling stuff.... not one thing will be displayed on that screen constantly!

    Kills burn-ins too...
    ---The Gentoo Troll
  • I have a SAMSUNG 171v

    It's a 17" analog flat panel LCD screen. I've had the same desktop "image" displayed for an entire weekend one time (with no DPMS to power it off).

    Checked it on Monday and it was like new. not even a slight ghost of a burn in.

    This problem must be dependant on certain factors because it isn't universal.

  • What they really need are screen protectors (Score:4, Insightful)

    by azav ( 469988 ) on Sunday June 22, 2003 @09:12PM (#6270275) Homepage Journal
    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.

  • More important than burn-in (Score:4, Informative)

    by Matt_Bennett ( 79107 ) on Sunday June 22, 2003 @09:15PM (#6270287) Homepage Journal
    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.

  • Burn in an image you at least like ... (Score:3, Funny)

    by 2TecTom ( 311314 ) on Sunday June 22, 2003 @09:56PM (#6270479) Homepage Journal
    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.

  • Apple 15" (Score:2, Informative)

    by Quicksilver31337 ( 541929 )
    I have had my Apple 15inch LCD which I bought with my G4 for the last 2 years, and it has only been turned off TWICE since I bought It, and both times were only while I moved it. In all that time at maximum brightness, without a screensaver running, I have never once had any issue of screen burn.
  • I have had a 22" cinema display for four years (one of Apples oldest LCDs), running many hours a day (main machine) with no burn-in. I have a G4 Powerbook over a year old with no problems, and the two+ year old G4 powerbook it replaced (sold to a friend) has no problem either. I also know a few people with LCD iMacs, with no problems. Sounds like a dubious rumour to me.
  • We do see this problem with Apple flatscreens in the computer lab setting where I work, but there is a fairly simple solution. Turn off the flatscreen for a day or so, and the burn in goes away. The optical mice were too sensitive, and were turning off the screensavers every time someone sat down at a table. Don't know if this will fix the Dell laptops, but our Dell laptops (and Apple laptops) seem to be fine so far.

    -Ryan
  • We have Dell SX-260's here with flat panels, and every one of them does it. Couldn't give you a timescale, but they all do it intermittently. A reboot usually clears it, but this is still using energy save shutdowns after 5 mins inactivity...

  • You shouldn't use a screensaver on LCD! (Score:4, Informative)

    by nomel ( 244635 ) <turd&inorbit,com> on Monday June 23, 2003 @11:59AM (#6273884) Homepage Journal
    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 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! :). I never used them. I just used a screen blanker, even with the old CRT's.
  • What happened to DPMS? Why don't you just enable that and be done with it?

    The only real excuse for screen savers in this age of DPMS enabled monitors (and don't even try to say your LCD screen doesn't have it) is for locking the workstation while you go take a piss. So I say again, what's your screen doing on after 10 minutes idle anyway?
    • Displaying the results of measurements. Only a few small parts of the screen are active, everything else can be unchanged for hours. The last thing I want to have to do while I'm tuning stuff is reach over and tap a key on the computer every 10 minutes to keep the screen up.

  • You would want the backlight to turn off. This will protect the CCF lamps from burnout. It will also reduce heat and conserve energy.

  • I had a monitor at work that had the energy saving feature wherein, if there is no video signal, it turns off automatically. So, at the end of the day, I would start the power off sequence and leave, under the impression that the monitor would automatically shut off. They switched monitors on me and I had to manually turn off the monitor. Unfortunately, I'm sometimes in a rush to leave the office, and I forget to manually shut it off. The price I have to pay? Permanently burned in my screen are the words "C

  • a flat screen (finally) to replace my huge-ass CRT, this kinda crap comes up. Are there any decent flats with decent response time (for gaming) that don't cost an arm and a leg AND don't suffer this burn-in crap?


    The prices for flats have gotten into the reasonable range but now they suck and aren't worth the price at all?

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