LCD burn-in

[Shrek]

I have a Securifi Almond that I keep running 24/7 showing the weather, but recently noticed screen burn-in; it seems to recover by itself if left with another (unchanging) image.

Are things on the way out?

 

[TheUn4seen]

Contrary to popular belief, LCDs do suffer from permanent burn-in. If memory serves me well, what causes it is low-level UV generated by the backlight slowly degrading polarizers in bright areas. It is a very slow process, I've only seen burn-in on screens displaying a static image 24/7/365 for several years in an industrial setting or in PoS devices. It's purely an aesthetic drawback and a fairly rare one, usually the backlight fails before burn-in becomes visible. If a device works, the screen burn-in won't cause it to fail. If it bothers you and you're feeling adventurous, you can try to find the screen's OEM part number and replace it, but it's perfectly safe to leave as is.

 

[joemama]

low-level UV generated by the backlight slowly degrading polarizers in bright areas

Why is it the bright areas? I would expect it to be the dark areas instead since the backlight illuminance is uniform and the dark areas are where the polarizers absorb the backlight

 

[Count von Schwalbe]

Why is it the bright areas? I would expect it to be the dark areas instead since the backlight illuminance is uniform and the dark areas are where the polarizers absorb the backlight

I would think so if it is the polarizing filters, but if it is the liquid crystal itself it would be the light areas.

 

[TheUn4seen]

Why is it the bright areas? I would expect it to be the dark areas instead since the backlight illuminance is uniform and the dark areas are where the polarizers absorb the backlight

There are two linear polarizers at a right angle to each other with crystals between them. First one provides polarized light from the backlight, the crystals change light polarization depending on voltage applied. What's left goes through the second polarizer, with this sandwich acting like a light valve. Add a red, green or blue color filter and you have a basic subpixel. You are right, the first polarizer gets damaged all the time the backlight is on, but that's uniform so not visible to the user. Second polarizer, however, gets less light - some is lost during the first stage (first polarizer) and the crystals, so it gets whatever is left. It receives the maximum amount of light polarized the way it needs - which is what wears it down, for the wrong polarization of light it is just an opaque filter. If you have a static, high contrast elements displayed for thousands of hours it will add up and the front polarizer also gets slowly damaged, but in a non-uniform fashion.
There are probably more factors at play. Those valves are usually of the "normally closed" type so to get the white color you need to open them fully - in other words, apply maximum voltage to the crystals - which likely wears them out faster. Heat from the backlight might play a role in their sensitivity to voltage or their natural breakdown rate. Monochrome FSTN displays are "normally open" and I very rarely saw them partially burned-in, even on decades old machines. Those displays are, however, not very dense so it's very hard to tell.

 

[Shrek]

Contrary to popular belief, LCDs do suffer from permanent burn-in. If memory serves me well, what causes it is low-level UV generated by the backlight slowly degrading polarizers in bright areas.

Just for cold cathode tubes or LED also?

 

[P4-630]

I had it once when using a TV as monitor, it looked like GPU-Z was burned in.
Later used as TV again and there was nothing to be seen anymore, even sold it.

 

[Frick]

Just for cold cathode tubes or LED also?

All LCD monitors have burn in, to some extent. The degree varies, and as said it generally is only noticable on stuff that's on literally all the time.

 

[Shrek]

I was glad that mine recovered by itself given time, but since I had not noticed this before I wondered if things are degrading.

 

[The red spirit]

All LCD monitors have burn in, to some extent. The degree varies, and as said it generally is only noticable on stuff that's on literally all the time.

Not really. My IPS BenQ has some nasty image retention issues, that mostly go way, but I don't keep it on 24/7.

 

[Frick]

Not really. My IPS BenQ has some nasty image retention issues, that mostly go way, but I don't keep it on 24/7.

And there you have it.

 

[P4-630]

I'll usually keep them on 25/8


j/k

 

[TheUn4seen]

Just for cold cathode tubes or LED also?

Both emit a little bit of UV, but CCFL backlight fades and drifts towards yellow (or pink if you're unlucky) well before you'd notice other problems.

 

[qubit]

Yeah, they suffer burn in too, but you have to really push it, as you've seen.

This incredible resistance to a very annoying problem is why I'm a die hard LCD user - with all of LCD's faults - until something better comes along. What's the point of a great picture with other tech if it gets easily ruined?

I've seen high end OLED smartphones with significant burn in after a relatively short time and it looks awful. Completely ruins the display. Might as well stick with LCD.

 

[Bill_Bright]

Contrary to popular belief, LCDs do suffer from permanent burn-in.

Huh? Contrary? It has always been known and widely accepted that LCD displays also suffer from burn-in. Not as bad as CRTs, but still a very real problem. Plasma screens suffer from it too.

In fact, the latest TVs, for example, particularly OLED TVs incorporate anti-burn-in technologies just to avoid those problems. My Samsung OLED, for example, can sense when a TV station keeps displaying their logo in the corner. News networks are notorious for this. The TV will inconspicuously move the logo around a pixel or two at a time.

I was glad that mine recovered by itself given time, but since I had not noticed this before I wondered if things are degrading.

It is not a matter of degradation. That is, an old screen is not more susceptible than a new screen just because it is old. It is all about the duration the same pixels are lit up with the exact same image. If worried, you will need to rotate images frequently - if possible. That said, not sure the harm in this scenario with your weather station. For example, does it really matter if the F and C are burned in forever? If there is a "dim" setting for the display, that could help delay the inevitable.

 

[phanbuey]

Oleds burn in and wear out because the self lit pixels do actually get worn and get dimmer...

LCDs have a backlight so all they're doing is modulating the light from that backlight... they don't really burn in - they may have image retention issues but the large majority of the time that's temporary and due to the crystals shifting out of position after being in the same place for a while. This is largely reversible as the crystals just need to shift back into their natural state, you can accelerate that by displaying different images and colors.

 

[The red spirit]

And there you have it.

???

 

[Bill_Bright]

they don't really burn in - they may have image retention issues

Good point - technically there is a difference between "burn-in" (with the phosphorous coating inside a CRT) and "image retention" with LCDs. But the visual effect - from the consumer's stand point - is essentially the same.

 

[phanbuey]

Lower quality panels will do stuff like degrade the polarizer, or the traces that send current to the pixels will burn out and cause dead or stuck pixels, but I would almost consider these generally panel/design defects.

I have some 4x3 dell LCD's around that have been on 24/7 for almost two decades and they haven't burned in, so i think it depends on the panel. But the tech does have the capability not to burn in, where as my oled... days are numbered for this thing.

 

[xtreemchaos]

ive never had problems with LCDs i did use a plasma hd tv some years ago as a monitor and ever time i turned it on the LG banner which come on would stay for 10min or so. the only thing i get burn in nowwa days is my ears when me mother in law wont stop talking, shes here now untill monday and im thinking hell would be better place to be thank the gods for VR and headphones eh.

 

[R-T-B]

And there you have it.

Image retention is different than burn in. One is temporary, the other permanent.

 

[Shrek]

Glad to learn that it may just be a transient thing and I can keep using my units as weather stations.

Thanks to one and all.

 

[AlwaysHope]

Could get burn in on plasma TVs when they were a thing. Seen it on Samsung units.

 

[eidairaman1]

Yeah, they suffer burn in too, but you have to really push it, as you've seen.

This incredible resistance to a very annoying problem is why I'm a die hard LCD user - with all of LCD's faults - until something better comes along. What's the point of a great picture with other tech if it gets easily ruined?

I've seen high end OLED smartphones with significant burn in after a relatively short time and it looks awful. Completely ruins the display. Might as well stick with LCD.

My Sig Rig Monitor experienced no burn in

 

[Bill_Bright]

Image retention is usually temporary. In severe cases - especially when preventative measures are ignored or circumvented - it can be permanent. And some types of displays are more susceptible than others.

Medical heath monitors and air port departure and arrival monitors are examples where the same information is displayed in the same screen location 24/7. Those monitors may suffer permanent retention.

LCD IMAGE RETENTION – EXPLAINED - NDS Surgical Imaging (ndssi.com)
LCD technology and image retention – CTOUCH Support