Burn-in on LCD monitor?

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4keatimj

[H]ard|Gawd
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My dad has a BenQ FP575 (I think). As he uses CAD everyday, he basically has the same window design open all day. He now has a white outline on the monitor where the edges of menus and buttons are in the CAD program. My question is: can LCD monitors suffer burn-in like CRT's? I was always told they didn't, but now I'm not sure anymore.
 
If they did it would be completely different from a CRT's. I don't think they can. What would burn in?
 
If they can, it would certainly not be like a CRT....CRTs have physical phosphors making up each pixel, and they glow themselves when hit by the electrons. If they are stimulated too long, they physically (and permanently) "burn in", and can't ever go back to their former state, just like a burnt piece of toast can never be turned back to a golden brown piece of bread. The pixels that didn't burn in appear normal, while the burnt pixels are darker, discolored, or however you want to describe it, and so you'll see the burned in image against the backdrop of normal pixels, sometimes even when the monitor is turned off. In CRTs, its a physical process.

But LCDs are different...The pixels have no physical makeup. In fact, technically they don't even exist. They are just shutters in front of a constant light source, the backlight. There is no individual phosphor glowing for each pixel, and they all share the same light from the backlight, which is entirely apart from the pixels themselves. The same light going through a pixel on the bottom row of the screen comes from the same light going through a pixel on the top row. Because the pixels aren't individually lighting up (or lighting up at all, for that matter...turn off the backlight and all you're left with is millions of tiny shutters), there is really nothing to burn in. Take those shutters away, and all you'll have left is basically one (or a few) big light bulb, and nothing is going to change on a light bulb that doesn't affect the light bulb as a whole, just like a bulb in a desk lamp. Unlike the burnt toast example, this case is more like a window in a house. The sun can come through that window all day long, yet once you close the curtains, there is no more light coming through. The sun can then shine on those curtains all day long, but once you open those curtains again, the light comes through exactly as before, and the sun shines exactly as before (too bad the backlight doesn't always in the long term, as it dims over the years).

I've heard cases of people somehow experiencing temporary burn in, but as would be expected, never anything permanent. Since the shutter is twisting liquid crystal, if it stays twisted for a long time, it can get used to it like marks in the carpet from a piece of furniture that hasn't been moved for a few days. Move the furniture, and the carpet eventually returns to normal. Likewise, if this happens with an LCD, turning it off for a day or cycling its state for a while will return it to normal. The only permanence I can think of is when a shutter stops working, freezing wherever it was, and then you have a dead pixel. Stacking pieces of furniture on your LCD will not fix dead pixels like the carpet. But even then, nothing burned in.
 
I've got an old Sony SDM-S51 LCD and once I left it on for a couple hours just showing the desktop, and the outlines of my icons were burned in a little. Also whenever i have IE open for an hour straight or the better part of a day (and SOB just right now) the line from the sroll bar gets burned in. Its just a faint line that you can really only see against a dark background, and its always goes away after having the monitor off for a few hours so I guess its nothing to worry about.
 
They can burn-in, but as mentioned above it is extremely rare and can usually be fixed by removing the power source for 24-48 hours.
 
Burn-in is a permament physical damage, and something that at least in theory shouldn't happen at all on LCDs. What can occur sometimes on LCDs is something called temporary image retention (TIR), visually the appearance is the same as with burn-in but with the difference that it dissapears when either shutting the screen off or displaying alternating colours on the screeen. I have read of rare cases though where the TIR seems to be very persistent to the degree that it can be considered permanent but this is really rare and an anomaly, not a flaw of LCD technology. LCD is the most burn-in resistant flat screen technology there is...
 
Thanks everyone. Its definately a sort of burn-in, he has the same screen on all day, and when you minimise the window back to the desktop there is a definate light patch where the edge of the toolbars are, and the top of the window. When saying burn-in, I don't mean in the same sense of 'burning' as a CRT, but showing something like an artifact from showing the same screen all day.

Thanks JackieO, I'll try what you suggested :)
 
i jsut got a dell 2000fp .. and if i leave something white .. like a window and a dark background for more than 10 minutes, there is a temporary burn in that lasts a couple minutes... its kind of annoying.. im wondering if that is becuase i left teh monitor on for 24 hours straight to test it.. but was wondering if anybody else had this problem
 
As a rule if that happens all you have to do is run a movie or anything with lots of motion that shows over the entire screen, it will go away then. A TV card is nice, go full screen and put on "raster" for an hour..fixes it right up.

Luck
 
I thought LCD did not suffer burn-it, but shadowing (where it leaves a temp image that can be erased by some means). I do not think LCD use phosphorus in any way. I know my new plasma I have to watch out about burn-in..
 
I tried what JackieO said, and fixed it. It does come back after a day or two, so every weekend he will disconnect the power to it. It solves the problem.

barking frog said:
Does he have contrast cranked up?
Click to expand...

I don't know, I'll have to check. Thanks for noting that.


I'll conclude by saying what I said previously - I used burn-in as an expression, as in some sort of image outline showing on the screen even though it isn't there. It was the only analogy I could think of, as I was in a bit of a hurry at the time. I didn't mean literal burn-in, obviously this happens in CRTs only. Rather, just an expression for what I was seeing. Just thought I should clear that up :)
 
Is burn in still a real problem on modern CRTs? I was under the impression that technology had advanced to the point where you'd really have to try to get an image to burn into a new CRT, if it were possible at all.
 
No, burn in is a problem inherent to CRTs. There is no technology that can overcome it. It is simply a permanent electrochemical change to the screen's phosphor coating caused by a static image being displayed for an extended period of time (hey, let's see you get charged to +25000V and get bombarded by electrons from three guns for an extended period of time, and see how you feel). The exact same thing can occur on a plasma screen, but cannot on a LCD.

LCD screens do have a very similar condition, but is much more difficult to cause. After a static image is displayed for an extremely long period of time, a charge can build up on certain pixels. Also, the response time of the controlling transistors can be very slightly altered as can the voltage level that causes them to switch on and off. Both effects are minor, but noticable. It's not "burn in" as such, but is a somewhat similar effect. The effect can be lessened by allowing the charge to completely drain.

The only prevention for either of these problems is to use screen savers as much as possible and to actually power down your monitor when not in use for an extended period of time.
 
4keatimj said:
I tried what JackieO said, and fixed it. It does come back after a day or two, so every weekend he will disconnect the power to it. It solves the problem.
Click to expand...

Glad it worked - I do the same thing to my laptop every now and again. The technical explainations in this thread are correct, but to put it in laymans terms - CRTs (direct and rear), PDPs, and LCDs (both direct and rear) can all suffer what we would refer to as "burn-in" in the sense that it is an image that is permenantly stuck on the screen. LCDs are way less likely to have this issue than CRTS and PDPs (which says something since despite the misinformation floating around CRTs and plasmas will almost never burn in either).
 
4keatimj said:
I tried what JackieO said, and fixed it. It does come back after a day or two, so every weekend he will disconnect the power to it. It solves the problem.
Click to expand...

At work we had the same type of issue with some user terminals burning in with features of the web browser and elements of the wall paper (machines are on 24x7 and either the browser or background were on for extended periods of time.) We found that implementing a screensaver solved the problem nicely. Also the the burn in symptoms already present corrected themselves after the screensaver as well.

So the quick version :D : You may want to look into decreasing your screensaver delay.

for what it's worth....
 
the effect you are seeing is leakage of some sort

at work we use lcd panels for factory automation and test in the lab, basicly the screen display the same window for months at a time with NO BREAK anywhere, they are then reused for another test again displaying stuff for months at a time, never any problems and these are cheap 15 to 17 inch panels (if you really want to know i'll write them down on monday)

i'm am confident it is not burn in
 
tomciob - I believe you when you say you're using LCDs for months at a time and not seeing burn in, but that doesn't mean it isn't possible. I have many instances of anecdotal evidence that suggests otherwise, but even ignoring that there is technical evidence that shows that LCDs can burn in. LCDs are far less likely to burn in than some other technologies, but it can and does happen. When you say 'leakage' do you mean backlight leakage? I am a little confused what you're refering to.
 
if i was sure what it is i wouldn't call it "some sort of leakage"
however i believe it has to do with (laymans terms) the pixels not closing properly (or perhaps subpixels) or maybe something with the controler board.
 
I just said it above but I'll rephrase it....On a CRT monitor, the pixels are lighting up individually by the electron gun, which hits the physical phosphors, and kamikazichaser explained how the pixels permanently change in burn-in. The LCD has none of this, it's just one big light bulb behind shutters that block out light...they are all being lit up together by the same light from the light bulb...It's just a grid of shutters superimposed on to the light bulb, so there is nothing to burn in! The only thing that can happen is if the shutters get used to being in a certain position for too long, and as many people have pointed out, just turn off your LCD for a while and it's okay. The only permanent problem that can be compared to burn-in is getting dead pixels.
 
You are exactly right. As can happen with any transistor with a constantly applied voltage, the individual pixels' controlling transistors can begin to malfunction over a period of time. The malfunction may appear as a "slow to respond" pixel or a pixel that appears stuck albiet usually only partially stuck. The simple way to alleviate the problem is to drain charge (unplug the monitor). Can there be permanent damage? Yes, but this would be rare. A transistor could eventually fail to respond to the previous voltage level required to switch it on or off. It could respond early, late, or not at all. The not at all one is usually called a "stuck" or "dead" pixel depending on the nature of its failure. Sometimes the lcd panel comes from the manuf. with one or more stuck or dead pixels, and these are caused by panel defects at the time of manufacturing. However, as I noted, it is possible for the panel's pixels to fail in a similar way over time. When you get right down to it, if you wait long enough, all the pixels will fail.

So, to LCD panel owners, make sure you use a screen saver and periodically power down your panel. In fact, periodically unplugging it wouldn't be a bad idea since you never really know how the power supply is wired up. Of course, this is the same advice I've given to CRT, plama, and DLP display owners. :D
 
Synful Serenity said:
I just said it above but I'll rephrase it....On a CRT monitor, the pixels are lighting up individually by the electron gun, which hits the physical phosphors, and kamikazichaser explained how the pixels permanently change in burn-in. The LCD has none of this, it's just one big light bulb behind shutters that block out light...they are all being lit up together by the same light from the light bulb...It's just a grid of shutters superimposed on to the light bulb, so there is nothing to burn in! The only thing that can happen is if the shutters get used to being in a certain position for too long, and as many people have pointed out, just turn off your LCD for a while and it's okay. The only permanent problem that can be compared to burn-in is getting dead pixels.
Click to expand...

As I said, I used burn-in as an expression for what I saw - not necessarily the literal explanation for what was happening. Thanks for the explanation though, and disconnecting the power supply has, as I said, worked. The screen saver solution is a good one, but the program that is causing the "burn-in" (again, expression, not literal explanation) is AutoCad, which he (my Dad) uses for his business. So the screen saver cannot go on, because he is using the program. Its just that the edges of the toolbar and menus, being in the same position all the time, cause the "burn-in". He uses a screen saver, but also minimises AutoCad when he isn't using it.

For now, though, disconnecting the power supply on the weekends (or whenever its off for extended periods of time) works. Thats the solution I was looking for :)
 
Guys, LCDs can irreparably, permanently burn-in. It isn't likely, it's hard to reproduce, and odds are you'll shrug me off as some internet crackpot which is all fine. The fact is it can and does happen.

Edit: I just want to point out that with current generation LCDs this is all but impossible to reproduce since polarizers have come far enough that it's generally a non-issue. But it can still happen. :)
 
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