Do Lcd's have burn in issues? thanks.

It's difficult, if not impossible, for an LCD to get permanent image retention. Some people say (but I've never seen, even after pausing video on my set for 6 hours or more, nor on any of my LCD computer screens) that you can get temporary image retention.

Any image retention will supposedly go away pretty quickly if you just turn off the set for a while or watch something else that doesn't have the same static image or network ID bug.

It's probably possible, but highly unlikely. I'm completely careless with my LCD (as far as preventing burn-in), and have sometimes left a static image on all night with no screen saver and haven't had any problem. I don't think you have anything to worry about.

From what I've researched, it seems like mild image retention is possible though.

only time i've seen it is on company computers that have the same login screen on. that's when they leave for the day and the login stays there for the next 16 hours. repeat for years = burn in.

it is possible depending on the technology used in the panels.

my Dell FP2007 (that I'm looking at right now) has horrible IR with high contrast images (which I see all the time with my web browser using tabs). so it's not immune but fundamentally more resistant. :)

it is NOT possible for lcd to get burn in. you can, however, see image persistence (an entirely different thing)

http://en.wikipedia.org/wiki/Image_persistence

a different mechanism, but effectively the same thing.

uneven phosphor wear (ie 'burn-in') can also be corrected and prevented in the same way that IR can be for an LCD.

point being that static images can be problematic for both lcd and phosphor based technologies.

the only technology that comes to mind that has absolutely ZERO risk is DLP.

it is possible depending on the technology used in the panels.

my Dell FP2007 (that I'm looking at right now) has horrible IR with high contrast images (which I see all the time with my web browser using tabs). so it's not immune but fundamentally more resistant. :)
Perhaps you should turn it off for a few days...

Perhaps you should turn it off for a few days...

work computer, it's not like I use it for critical viewing. besides, it automatically shuts itself off when idle. ;)

LCD get a retained image. There are two causes. First, the LCD is scanned with an AC wave form. Every other frame, the polarity is reversed on the flow through the LCD molecules. If the AC wave form is off, one side can "plate up" and this can cause a stuck image. The other cause is when the TFT (transistor) gets a charge in it and so the transistor is always a little "on". This too will cause an image.

In both cases, the charges can and will go away so there is no permanent image.

On a plasma, if the phosphors truely age unevenly, there is no way to correct it (sorry). All light emitting materials will give off less light over time. If some phosphors are used more than others, then there is no practical way to stop using the aged pixels and only used the new and fresh pixels.

So I don't have to worry about burn in if I watched with black bars, either horizontal or vertical, right?

I have seen one LCD with permanent burn in. It was an Apple computer monitor and you could clearly see the mac OS menu bar across the top of the screen (you could even read some of the menus). It was still there despite having been turned off for months before I got it. I ran it for several weeks on a Windows computer and it didn't fade at all. In this case, the monitor was probably on 24/7 for several years. Even then, it wasn't very noticeable under normal use. It mostly stood out on black, or dark gray.

My conclusion is that it's possible under extreme circumstances, but not under normal use. Just don't leave your TV on 24/7 with the same static high contrast graphics on the screen!

Black on an LCD is OFF. If they are there all the time, there should not be any permanent image. But as mentioned, leaving anything on a set, in a static mode 24/7 is not wise.

On a plasma, if the phosphors truely age unevenly, there is no way to correct it (sorry). All light emitting materials will give off less light over time. If some phosphors are used more than others, then there is no practical way to stop using the aged pixels and only used the new and fresh pixels.

If you ran an negative image it would theoretically be possible to correct. You might not want to do it, and it's better to avoid it in the first place (ie where we are at right now with mainstream plasma technology), but it is possible to stress the less aged phosphors while not stressing the previously overstimulated ones.

But again, we are splitting hairs to begin with. Less of an issue for LCD than plasma, but really not a concern for either outside of digital signage (and even there not so much as 3-4 years ago).

I'm sure we will revisit this topic with any xED or OLED products that come to market in the future.

So I don't have to worry about burn in if I watched with black bars, either horizontal or vertical, right?

generally speaking, yes, don't worry about it.

if you want the full disclaimer- provided you aren't running in 'torch' mode and that's not all that you ever watch (ie you watch a mix of programming with different aspect ratios), and use the features in your tv to reduce the risk of burn in (eg pixel shifting) it shouldn't be an issue. phosphor technology in plasma has come a long way (crt levels and you didn't worry about it then, right?)

Sounds good, thanks.