5 ms·

"burn-in" on OLED is actually the degradation of brightness of LEDs based on their operation hours. The impact is just more noticable on OLED because the pixels

"burn-in" on OLED is actually the degradation of brightness of LEDs based on their operation hours. The impact is just more noticable on OLED because the pixels degrade individually (instead of LED-LCDs, where both brightness and color degrades uniformly across the whole zone of the backlight) There's lots of methods now to make this degradation more uniform on OLED, like slightly shifting the image to distribute the load onto multiple subpixels, "cleaning" the panel when its switched off, down to measuring the operating hours of individual pictures and adjusting the brightness of surrounding pixels to blend the degradation. Overall you can choose what you want to degrade over those 10 years: The LED brightness and color-accuracy of a whole zone / backlight unit (LED-LCD), or have the OLED panel actively compensate its aging (which has gotten ALOT better in the past years) Either way, I wouldn't put my money on QLED (which is not a technology but a brand). QLED is actually far worse on lifetime than OLED [1], but as it was driven by the marketing powerhouse of Samsung this information is barely known. Considering how expensive it is to produce and that it was basically only made by Samsung to buy time until they can produce OLED as well, I wouldn't expect it to become actually a mature technology. It's more likely that they will replace the Quantum Dot backlight with something cheaper and still keep the brand "QLED" (if they haven't done that already). AH-IPS LCD panels with zoned LED backlight probably still provide the most stable picture quality over longer time of use, compromising on image-quality compared to OLED. But the last really good TV with such a panel was produced quite a few years ago already... [1] https://www.nature.com/articles/s41467-019-08749-2 https://www.nature.com/articles/s41467-019-08749-2

oblio 3y ago
I don't care much about average panel degradation. I do care about seeing ghost letters or shapes on top of the latest TV series I'm watching. Edit: The QLED article is from 2019, that's quite a few yers ago for cutting edge tech. I imagine tech is constantly improving.
- rickdeckard 3y ago
  You'll be fine with any of the existing technologies of today. In either case you will see luminance degradation over time, in case of LED-LCD or QLED also color-shifts of backlight zones. But none of this is new. In reality, I barely heard people complain about their LCDs becoming more and more weak in brightness and color-tinted (usually yellow) each year. And yet, all of this happened to 100% of all LED-LCD panels. > Edit: The QLED article is from 2019, that's quite a few yers ago for cutting edge tech. I imagine tech is constantly improving. Yeah, there's alot of research ongoing to improve QD lifetime as a foundation for new LED technology. Here's one from Dec.2022 [1], and one from as late as 2023 [2], all with the subject of solving performance stability of the technology to become on-par (!) with common LED. [1] https://pubs.acs.org/doi/full/10.1021/acsaelm.2c01351 https://pubs.acs.org/doi/full/10.1021/acsaelm.2c01351 [2] https://pubmed.ncbi.nlm.nih.gov/36990060/ https://pubmed.ncbi.nlm.nih.gov/36990060/
  - dahfizz 3y ago
    You're missing the point: > I don't care much about average panel degradation. > I do care about seeing ghost letters or shapes on top of the latest TV series I'm watching. Nobody cares about "luminance degradation", they just dont want ghosting
    - rickdeckard 3y ago
      No I did not. Check the first sentence of my reply: "You'll be fine with any of the existing technologies of today." And "ghosting" are artifacts on fast movement due to a lag in panel refresh, it's something entirely different.
      - 411111111111111 3y ago
        > You'll be fine with any of the existing technologies of today I think you're going too far with your statement. OLED/qd-oled and to a lesser degree WOLED all suffer from significant burn-in, which makes them pretty bad for desktop use. Previous LCD technologies will degrade over the years by losing luminance and color accuracy, but that's a pretty minor issue compared to OLED as far as I'm concerned.
      - BearOso 3y ago
        From context, you know the post is talking about ghosting from image retention, not ghosting from motion blur. Please don't be pedantic. We're not all versed in the terminology.
        Sohcahtoa82 3y ago
        I'm pretty sure that on HN, being pedantic is basically required by law.
    - deleted 3y ago
      [deleted]
    - BearOso 3y ago
      I think the point you're trying to make is you can calibrate away LCD backlight luminance degradation because it's uniform across the panel. And you don't notice because your eyes adapt to the whole screen. With OLED, not so much. OLED does have tech to compensate based on total pixel usage. You might see that if you tried to change a panel without the electronics. I'm not aware of how widespread it is, but I know iphones can do it.
- jabroni_salad 3y ago
  You might be interested in the RTings longevity test which is exactly about that. The current round is playing CNN for 20 hours a day for 2 years, and they already have some results at the 6 month mark. https://www.rtings.com/tv/tests/longevity-burn-in-test-updates-and-results https://www.rtings.com/tv/tests/longevity-burn-in-test-updat...
  - kurthr 3y ago
    Thanks! This is a great overview demo of current panels! You can already see some very slight degradation in some of LGs OLEDs, but many of the Sony/Visio (and Samsung) OLED panels. The others mostly look like standard LCD and DDI/Flex defects rather than burn-in so far.
makomk 3y ago
As far as I can tell, the QLED screens on the market are not based on the QLED technlogy that article is about, and the lifetimes given in that article are obviously far too low to build a usable television set with. They claim non-uniform degradation between different colours with blue in particular dropping to half the initial output after just 20 hours - that's nothing compared to the life of a TV set. Samsung QLED TVs seem to use standard LEDs in the backlight with a seperate quantum dot layer that improves colour accuracy and gamut.
- rickdeckard 3y ago
  It is the same technology. Samsung is just compensating the deficiency of Blue QD by using conventional Blue LEDs in their QLED TVs (creating white light with Green and Red QD as you wrote as well). The point is that the degradation of QD material still exists, and along with the usual degradation of the Blue LED, also the QD-material will degrade and shift over time. The research paper describes the lifetime and degradation in a uniform setup, as it's research for foundational QD-tech, not for TV panels. There's alot of research ongoing to improve QD lifetime as a foundation for new LED technology. Here's one from Dec.2022 [1], and one from as late as 2023 [2], all with the subject of solving performance stability of the technology to become on-par (!) with common LED. [1] https://pubs.acs.org/doi/full/10.1021/acsaelm.2c01351 https://pubs.acs.org/doi/full/10.1021/acsaelm.2c01351 [2] https://pubmed.ncbi.nlm.nih.gov/36990060/ https://pubmed.ncbi.nlm.nih.gov/36990060/
causi 3y ago
There is certainly a difference in either technology or implementation. I've seen LG OLED TVs get noticeable lettering burn-in after a couple hundred hours and on the other end of the spectrum that guy left an unmoving bright-dark pattern on his OLED Switch for over a year straight before seeing any.
meragrin_ 3y ago
> It's more likely that they will replace the Quantum Dot backlight with something cheaper and still keep the brand "QLED" (if they haven't done that already). Or something more expensive? Not sure if OLED is more expensive or not, but they are already using that as a backlight on the high-end. Specifically, blue which seems to be the issue for QLEDs if the paper is anything to go by.
- rickdeckard 3y ago
  My point was that "QLED" is actually a registered brand and doesn't represent a specific technology, so Samsung Display could change the underlying tech, adjust the meaning of "QLED" and keep going. If they replace it with something more expensive they usually give it a new name to sell the higher price, like "Neo QLED"
ilyt 3y ago
> The impact is just more noticable on OLED because the pixels degrade individually (instead of LED-LCDs, where both brightness and color degrades uniformly across the whole zone of the backlight) Don't organic LEDs also degrade more than their "normal" counterparts? > Overall you can choose what you want to degrade over those 10 years: The LED brightness and color-accuracy of a whole zone / backlight unit (LED-LCD), or have the OLED panel actively compensate its aging (which has gotten ALOT better in the past years) I'd imagine it would be FAR easier to compensate the backlight as you just need to re-calibrate one string of LEDs that all see same load over lifetime of the monitor vs somehow tracking per-subpixel usage of each OLED
- rickdeckard 3y ago
  > Don't organic LEDs also degrade more than their "normal" counterparts? Yeah, amplified due to their much smaller size, having less surface area for heat dissipation, and also depending on pixel-color in RGB-OLED setups. On TV's WOLED panels are used instead of RGB-OLED, which allows for better heat-distribution and a uniform lifetime regardless of pixel-color. > I'd imagine it would be FAR easier to compensate the backlight as you just need to re-calibrate one string of LEDs that all see same load over lifetime of the monitor vs somehow tracking per-subpixel usage of each OLED For luminance there is nothing to compensate, as it simply degrades uniformly. The peak-brightness is simply reducing over time. Color-shifts cannot be re-calibrated that well because the shift happens due to the chemical decomposition process of the phosphor in each LED, which causes the color of the light going INTO the color-filter to shift (the base light that is filtered for RGB is no longer white). Once it starts it's not a binary process, the color keeps shifting. Manual recalibration often has no real benefit then, as the color-shift continues and is not uniform across the whole display.
  - ilyt 3y ago
    > Color-shifts cannot be re-calibrated that well because the shift happens due to the chemical decomposition process of the phosphor in each LED, which causes the color of the light going INTO the color-filter to shift (the base light that is filtered for RGB is no longer white). But you can change white balance of most monitors right ? So they at the very least need cold white and warm white LEDs, just change balance of those. using RGB LEDs in backlight could also allow for that correction.
kurthr 3y ago
Sorry, but I've been in that industry (LCD and OLED) for over 10 years and this doesn't match with my understanding. QLED is basically an LCD technology with QuantumDot on top. It is just Samsung's marketing. Most all mid tier LCD TVs currently use QD (whether in the backlight or the color filter layers). They don't use Blue QD (only longer lifetime Red/Green), but crystal InGaN in the Blue backlight. Other lower end LCDs use RG phosphor instead of QD to produce white, which also has long term burn-in issues, but as you mention they are not individual to pixels. Color shift of the (global backlight) screens over years can be compensated, but since environmental lighting has a bigger effect on perceived color, I'm not sure why you'd bother (mini-LED can be worse). Even the very best currently shipping OLEDs (not yet phosphorescent Blue) have visible burn-in at ~2000hr even with image shifting de-contrast techniques. Early 2014 QD (Red/Green) have visible burn-in at ~7khr and modern ones about 20khr. They're about 10x better than OLEDs, but you could still see it several years in (rather than months in for OLED). I've got no great love for QLED, but R/G QD just doesn't have the same level of burn-in problems that fluorescent Blue OLED does, and neither do Blue InGaN LEDs. https://en.tab-tv.com/samsung-has-released-recommendations-for-viewing-tv-screens-with-quantum-dot/ https://en.tab-tv.com/samsung-has-released-recommendations-f... I'm including this link, because the SID.org papers are all paywalled.
- rickdeckard 3y ago
  Same here, working with and in that industry for ~17 years on technology strategy. I'm no evangelist either, neither for LCD nor OLED. I frankly don't know how you technically define "visible burn-in" in context of QD (do you mean actual pure QD tech or Samsungs mixed use of the tech for QLED TVs?). If we can agree, that: 1.) The jargon "burn-in" on OLED describes the luminance degradation of individual sub-pixels (i.e. a weaker red because the operation hours of a red sub-pixel were much higher than its neighbours). 2.) Samsung's "QLED" is a brand for a LCD panel with the backlight created using R/G QD and blue LED (instead of blue/yellow LED). The backlight on standard QLED is separated in ~700 zones of the display, so you have huge clusters of pixels using the same backlight zone. Then: What is the equal meaning of "burn-in" then in the context of QLED? The luminance degradation of the whole zone? Or is it the "legacy" meaning of burn-in on LCD: The occurence of weaker/dead pixels due to issues in the TFT layer (broken/weak transistors no longer properly rotating the crystals)? Either way, I can't confirm and don't agree that OLED TVs will see a visible "burn-in" after ~2000hrs of normal use. First-gen models yes, but definitely not currently shipping models.

oblio 3y ago

I don't care much about average panel degradation. I do care about seeing ghost letters or shapes on top of the latest TV series I'm watching. Edit: The QLED article is from 2019, that's quite a few yers ago for cutting edge tech. I imagine tech is constantly improving.

rickdeckard 3y ago
You'll be fine with any of the existing technologies of today. In either case you will see luminance degradation over time, in case of LED-LCD or QLED also color-shifts of backlight zones. But none of this is new. In reality, I barely heard people complain about their LCDs becoming more and more weak in brightness and color-tinted (usually yellow) each year. And yet, all of this happened to 100% of all LED-LCD panels. > Edit: The QLED article is from 2019, that's quite a few yers ago for cutting edge tech. I imagine tech is constantly improving. Yeah, there's alot of research ongoing to improve QD lifetime as a foundation for new LED technology. Here's one from Dec.2022 [1], and one from as late as 2023 [2], all with the subject of solving performance stability of the technology to become on-par (!) with common LED. [1] https://pubs.acs.org/doi/full/10.1021/acsaelm.2c01351 https://pubs.acs.org/doi/full/10.1021/acsaelm.2c01351 [2] https://pubmed.ncbi.nlm.nih.gov/36990060/ https://pubmed.ncbi.nlm.nih.gov/36990060/
- dahfizz 3y ago
  You're missing the point: > I don't care much about average panel degradation. > I do care about seeing ghost letters or shapes on top of the latest TV series I'm watching. Nobody cares about "luminance degradation", they just dont want ghosting
  - rickdeckard 3y ago
    No I did not. Check the first sentence of my reply: "You'll be fine with any of the existing technologies of today." And "ghosting" are artifacts on fast movement due to a lag in panel refresh, it's something entirely different.
    - 411111111111111 3y ago
      > You'll be fine with any of the existing technologies of today I think you're going too far with your statement. OLED/qd-oled and to a lesser degree WOLED all suffer from significant burn-in, which makes them pretty bad for desktop use. Previous LCD technologies will degrade over the years by losing luminance and color accuracy, but that's a pretty minor issue compared to OLED as far as I'm concerned.
    - BearOso 3y ago
      From context, you know the post is talking about ghosting from image retention, not ghosting from motion blur. Please don't be pedantic. We're not all versed in the terminology.
      - Sohcahtoa82 3y ago
        I'm pretty sure that on HN, being pedantic is basically required by law.
  - deleted 3y ago
    [deleted]
  - BearOso 3y ago
    I think the point you're trying to make is you can calibrate away LCD backlight luminance degradation because it's uniform across the panel. And you don't notice because your eyes adapt to the whole screen. With OLED, not so much. OLED does have tech to compensate based on total pixel usage. You might see that if you tried to change a panel without the electronics. I'm not aware of how widespread it is, but I know iphones can do it.
jabroni_salad 3y ago
You might be interested in the RTings longevity test which is exactly about that. The current round is playing CNN for 20 hours a day for 2 years, and they already have some results at the 6 month mark. https://www.rtings.com/tv/tests/longevity-burn-in-test-updates-and-results https://www.rtings.com/tv/tests/longevity-burn-in-test-updat...
- kurthr 3y ago
  Thanks! This is a great overview demo of current panels! You can already see some very slight degradation in some of LGs OLEDs, but many of the Sony/Visio (and Samsung) OLED panels. The others mostly look like standard LCD and DDI/Flex defects rather than burn-in so far.

makomk 3y ago

As far as I can tell, the QLED screens on the market are not based on the QLED technlogy that article is about, and the lifetimes given in that article are obviously far too low to build a usable television set with. They claim non-uniform degradation between different colours with blue in particular dropping to half the initial output after just 20 hours - that's nothing compared to the life of a TV set. Samsung QLED TVs seem to use standard LEDs in the backlight with a seperate quantum dot layer that improves colour accuracy and gamut.

rickdeckard 3y ago
It is the same technology. Samsung is just compensating the deficiency of Blue QD by using conventional Blue LEDs in their QLED TVs (creating white light with Green and Red QD as you wrote as well). The point is that the degradation of QD material still exists, and along with the usual degradation of the Blue LED, also the QD-material will degrade and shift over time. The research paper describes the lifetime and degradation in a uniform setup, as it's research for foundational QD-tech, not for TV panels. There's alot of research ongoing to improve QD lifetime as a foundation for new LED technology. Here's one from Dec.2022 [1], and one from as late as 2023 [2], all with the subject of solving performance stability of the technology to become on-par (!) with common LED. [1] https://pubs.acs.org/doi/full/10.1021/acsaelm.2c01351 https://pubs.acs.org/doi/full/10.1021/acsaelm.2c01351 [2] https://pubmed.ncbi.nlm.nih.gov/36990060/ https://pubmed.ncbi.nlm.nih.gov/36990060/

causi 3y ago

There is certainly a difference in either technology or implementation. I've seen LG OLED TVs get noticeable lettering burn-in after a couple hundred hours and on the other end of the spectrum that guy left an unmoving bright-dark pattern on his OLED Switch for over a year straight before seeing any.

meragrin_ 3y ago

> It's more likely that they will replace the Quantum Dot backlight with something cheaper and still keep the brand "QLED" (if they haven't done that already). Or something more expensive? Not sure if OLED is more expensive or not, but they are already using that as a backlight on the high-end. Specifically, blue which seems to be the issue for QLEDs if the paper is anything to go by.

rickdeckard 3y ago
My point was that "QLED" is actually a registered brand and doesn't represent a specific technology, so Samsung Display could change the underlying tech, adjust the meaning of "QLED" and keep going. If they replace it with something more expensive they usually give it a new name to sell the higher price, like "Neo QLED"

ilyt 3y ago

> The impact is just more noticable on OLED because the pixels degrade individually (instead of LED-LCDs, where both brightness and color degrades uniformly across the whole zone of the backlight) Don't organic LEDs also degrade more than their "normal" counterparts? > Overall you can choose what you want to degrade over those 10 years: The LED brightness and color-accuracy of a whole zone / backlight unit (LED-LCD), or have the OLED panel actively compensate its aging (which has gotten ALOT better in the past years) I'd imagine it would be FAR easier to compensate the backlight as you just need to re-calibrate one string of LEDs that all see same load over lifetime of the monitor vs somehow tracking per-subpixel usage of each OLED

rickdeckard 3y ago
> Don't organic LEDs also degrade more than their "normal" counterparts? Yeah, amplified due to their much smaller size, having less surface area for heat dissipation, and also depending on pixel-color in RGB-OLED setups. On TV's WOLED panels are used instead of RGB-OLED, which allows for better heat-distribution and a uniform lifetime regardless of pixel-color. > I'd imagine it would be FAR easier to compensate the backlight as you just need to re-calibrate one string of LEDs that all see same load over lifetime of the monitor vs somehow tracking per-subpixel usage of each OLED For luminance there is nothing to compensate, as it simply degrades uniformly. The peak-brightness is simply reducing over time. Color-shifts cannot be re-calibrated that well because the shift happens due to the chemical decomposition process of the phosphor in each LED, which causes the color of the light going INTO the color-filter to shift (the base light that is filtered for RGB is no longer white). Once it starts it's not a binary process, the color keeps shifting. Manual recalibration often has no real benefit then, as the color-shift continues and is not uniform across the whole display.
- ilyt 3y ago
  > Color-shifts cannot be re-calibrated that well because the shift happens due to the chemical decomposition process of the phosphor in each LED, which causes the color of the light going INTO the color-filter to shift (the base light that is filtered for RGB is no longer white). But you can change white balance of most monitors right ? So they at the very least need cold white and warm white LEDs, just change balance of those. using RGB LEDs in backlight could also allow for that correction.

kurthr 3y ago

Sorry, but I've been in that industry (LCD and OLED) for over 10 years and this doesn't match with my understanding. QLED is basically an LCD technology with QuantumDot on top. It is just Samsung's marketing. Most all mid tier LCD TVs currently use QD (whether in the backlight or the color filter layers). They don't use Blue QD (only longer lifetime Red/Green), but crystal InGaN in the Blue backlight. Other lower end LCDs use RG phosphor instead of QD to produce white, which also has long term burn-in issues, but as you mention they are not individual to pixels. Color shift of the (global backlight) screens over years can be compensated, but since environmental lighting has a bigger effect on perceived color, I'm not sure why you'd bother (mini-LED can be worse). Even the very best currently shipping OLEDs (not yet phosphorescent Blue) have visible burn-in at ~2000hr even with image shifting de-contrast techniques. Early 2014 QD (Red/Green) have visible burn-in at ~7khr and modern ones about 20khr. They're about 10x better than OLEDs, but you could still see it several years in (rather than months in for OLED). I've got no great love for QLED, but R/G QD just doesn't have the same level of burn-in problems that fluorescent Blue OLED does, and neither do Blue InGaN LEDs. https://en.tab-tv.com/samsung-has-released-recommendations-for-viewing-tv-screens-with-quantum-dot/ https://en.tab-tv.com/samsung-has-released-recommendations-f... I'm including this link, because the SID.org papers are all paywalled.

rickdeckard 3y ago
Same here, working with and in that industry for ~17 years on technology strategy. I'm no evangelist either, neither for LCD nor OLED. I frankly don't know how you technically define "visible burn-in" in context of QD (do you mean actual pure QD tech or Samsungs mixed use of the tech for QLED TVs?). If we can agree, that: 1.) The jargon "burn-in" on OLED describes the luminance degradation of individual sub-pixels (i.e. a weaker red because the operation hours of a red sub-pixel were much higher than its neighbours). 2.) Samsung's "QLED" is a brand for a LCD panel with the backlight created using R/G QD and blue LED (instead of blue/yellow LED). The backlight on standard QLED is separated in ~700 zones of the display, so you have huge clusters of pixels using the same backlight zone. Then: What is the equal meaning of "burn-in" then in the context of QLED? The luminance degradation of the whole zone? Or is it the "legacy" meaning of burn-in on LCD: The occurence of weaker/dead pixels due to issues in the TFT layer (broken/weak transistors no longer properly rotating the crystals)? Either way, I can't confirm and don't agree that OLED TVs will see a visible "burn-in" after ~2000hrs of normal use. First-gen models yes, but definitely not currently shipping models.