[HN Gopher] Tandem OLED is OLED's latest weapon in holding off M...
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Tandem OLED is OLED's latest weapon in holding off MicroLED, QDEL
Author : rbanffy
Score : 82 points
Date : 2024-09-24 10:23 UTC (4 days ago)
(HTM) web link (arstechnica.com)
(TXT) w3m dump (arstechnica.com)
| bluSCALE4 wrote:
| What's annoying is that this tech already existed for LCD
| screens. It supposedly had deep black that OLED brings but at LCD
| prices. If the quality is similar / no better, it's frustrating
| to see tandem tech never made it out of China.
| jsheard wrote:
| Those Hisense tandem LCDs had some significant issues that they
| weren't able to iron out, they had trouble with poor response
| times, ghosting, and color banding. Flanders Scientific also
| used to make tandem LCDs for ultra-high-end professional
| monitoring, which was a market that could tolerate high prices
| and poor power efficiency in the name of performance, but even
| they have migrated their HDR monitors over to QD-OLED now so I
| think the consensus is that tandem LCD is a dead end.
| kingsleyopara wrote:
| Dual-layer LCD is best thought of as a separate technology from
| tandem OLED, due to being transmissive rather than emissive. In
| many respects, it surpasses OLED, which is why mastering
| monitors used in Hollywood still employ this technology.
| Unfortunately, the poor efficiency and excessive energy
| consumption/heat output have hindered its adoption in the
| consumer market.
| jsheard wrote:
| > In many respects, it surpasses OLED, which is why mastering
| monitors used in Hollywood still employ this technology.
|
| Flanders Scientific were the main champions of dual LCDs in
| that market, and even they have phased out all of their dual
| LCD models in favor of QD-OLED ones now. I think they just
| brute force through OLEDs usual brightness limits by actively
| cooling the panel.
| rbanffy wrote:
| And speaking of high-brightness LED panels, I can swear I
| got a tan from one during a conference where the panel was
| sitting with the back towards the panel.
|
| Those things are hot and very bright.
| porphyra wrote:
| Dual LCDs also have poor brightness since a lot less light
| gets through the two layers. That can be overcome by a much
| stronger backlight, which produces tons of heat that
| require active cooling.
| kuschku wrote:
| Sony also makes dual-layer LCDs, they even introduced a new
| model in 2023:
| https://pro.sony/en_GB/products/broadcastpromonitors/bvm-
| hx3...
| jsheard wrote:
| Good to know, but that spec sheet neatly demonstrates the
| efficiency challenges of dual-layer LCD. That's a 31"
| panel which burns up to 610 watts!
| formerly_proven wrote:
| That's probably illegal to sell in the EU?
| wmf wrote:
| It's a professional reference monitor not a TV so maybe
| there's an exception.
| kuschku wrote:
| Those rules and regulations only apply to consumer
| products, business/professional products are exempt. This
| product is obviously not a consumer product.
| anamexis wrote:
| Also, it costs $25,000. But that might not be related to
| it being a dual-layer LCD, but rather other exacting
| tolerances for professional mastering use.
| fngjdflmdflg wrote:
| >It supposedly had deep black that OLED brings
|
| How does stacking displays let you get pixel level light
| emission of OLED or better blacks in general? The issue with
| LCD is that there is a display wide backlight so you have to
| actively block out the the backlight to make black. Even if
| there was some tech to stack something that added more blocking
| (I guess, adding another liquid crystal layer? Another
| polarizer? I admit to not really understanding the tech beyond
| a surface level, just trying to understand.), it doesn't seem
| to be the same tech as stacking OLEDs which is to get more
| brightness/less burnout. And if you mean stacking more light
| emission as in the case of OLED, that also wouldn't seem to
| contribute to better blacks.
| mapt wrote:
| Two LCDs, front to back, provide much better contrast by
| blocking more of the light in the liquid crystal layers.
|
| The rear one is greyscale.
|
| https://www.reddit.com/r/hardware/comments/w0u2rf/did_dual_l.
| ..
|
| https://www.rtings.com/tv/reviews/hisense/u9dg
| rbanffy wrote:
| OTOH, an LCD, at best, let's 50% of the light pass through
| it, so, for two stacked LCD panels, you'll need a much
| brighter backlight.
| toast0 wrote:
| LCDs work on polarization... you typically have an
| unpolarized source, run it through a polarized filter
| which is where your 50% loss comes from, then the LCD
| changes or doesn't the polarization, and you run it
| through a filter again. If you stacked a second LCD, you
| shouldn't see a second 50% loss, the light is already
| polarized by the first LCD.
| rbanffy wrote:
| You are right - the 50% loss comes from the filters, but
| I forgot to count the loss from the filters. You could
| add a second monochrome LCD on top of the first one for
| the same result.
|
| I must be wrong, because this sounds very trivial.
| fngjdflmdflg wrote:
| >The rear one is grayscale.
|
| If I understand correctly, you're saying that there is a
| rear LCD that only either lets light in or blocks it
| without caring about the color? That's interesting. As for
| why they aren't investing in this then, it's might be at
| least in part due to the power usage which would make it
| unsuitable for battery powered devices such as the iPad
| mentioned in the article.
| Kirby64 wrote:
| Due to the way LCDs work it's never useful for a consumer
| monitor. The backlights needed to punch enough lumens through 2
| layers of LCD is prohibitively large/expensive, and the cooling
| needed to make sure you don't burn it out leads to a pretty
| thick and bulky design. Take a look at the professional
| monitors like this... there's a reason why they're so thick,
| and it's not because they're "industrial" or something. Also,
| power consumption is atrocious.
| rbanffy wrote:
| This sounds like a problem that PixelQi tech could solve - it
| used prisms instead of filters for colours, which reduced
| light absorption on inactive LCD pixels, so if the lower LCD
| is a PixelQi panel, you can add a set of filters with the
| second LCD panel and drive the backlight harder to gain
| better contrast (a problem with PixelQi) within the same
| power envelope of a "regular" LCD.
| tedunangst wrote:
| There's a diy perks video about making your own which goes into
| the pros and cons for the curious.
| cayleyh wrote:
| I thought MicroLED was not really ready to compete outside a TV-
| sized form factor due to the difficulty & costs to manufacture it
| at competitive resolution density for phones/tablets? Has that
| changed substantially since Apple cancelled it's MicroLED project
| for the Apple watch?
| porphyra wrote:
| yea it seems that microled is good at either being really big
| (110" TVs) or really small (VR headsets), but nothing in
| between yet.
| ivewonyoung wrote:
| > or really small (VR headsets)
|
| That's MicroOLED in the Apple Vision Pro, not MicroLED.
| Confusing, I know.
| porphyra wrote:
| I'm not talking about micro OLED. I'm talking about
| microled which is indeed made in small chips with VR and AR
| as the target market.
|
| For example the recently announced Meta Orion is said to
| use microled [1].
|
| At the recent microled connect conference there were lots
| of VR/AR focused talks [2].
|
| [1] https://www.microled-info.com/meta-announces-10000-ar-
| glasse...
|
| [2] https://www.microledconnect.com/current-agenda
| refulgentis wrote:
| Er, no.
|
| It's not shipping today for anything smaller than 8 foot
| TVs, and doesn't have a path.
|
| It's been 5 years away for at least a decade.
|
| OP is referencing Apple Watch cancellation because that
| was Apple throwing in the towel in microLED after a
| decade of investment, making it likely no one expects it
| to be solved soon.
|
| [1] Facebook is using a MicroLED _projector_ and
| expressly says the display is an unknown unknown, because
| they can 't ship this one if they wanted to. The failure
| rates are too high (see manufacturing process in [2]).
|
| [2] has been happening for at least 8 years. It'd be
| awesome for VR, but that's the least likely near term
| option because right now it boils down to "manually place
| 8,294,400 pixels and if any have errors, do it again."
| Its shipping at eye-watering prices in Samsung TVs > 100"
| (read: have "huge" pixel sizes so they can be manually
| placed)
| throwaway48476 wrote:
| They're still doing pick and place with millions of individual
| LEDs.
| lightedman wrote:
| Oh, no, we don't use pick and place for micro LED. We use
| LASER-Induced Forward Transfer - ie we blast the LED straight
| off the wafer and onto the screen substrate and precision-
| align it with another aimed laser pulse.
| jjcm wrote:
| Manufacturing is still the biggest bottleneck, but resolution
| density is very achievable. Jade Bird Display is a manufacturer
| I follow as they make extremely dense, high refresh rate, high
| brightness microled displays for projector purposes:
| https://www.jb-display.com/.
|
| The main product they sell are monochrome 3.3mm 640x480
| displays (1 million nits!), but they do have 2k resolution
| 5.6mm RGB displays: https://www.jb-display.com/company/127.html
| thfuran wrote:
| Aren't the tiny displays manufactured all on a wafer,
| bypassing the need for assembling all the individual LED
| elements that causes problems for the TV-sized displays?
| enos_feedler wrote:
| No. The pixels still need a transfer step
| siffin wrote:
| All I have to say is that the tandem oled on my ipad pro still,
| everytime I use it, makes me wow. It is an absolute pleasure to
| look at and watch things on. It feels like I'm watching real life
| and I love it.
| crancher wrote:
| Using it in a dark room is weird at times. The pure blacks
| create the strange illusion of holding something lit that you
| cannot see.
| kccqzy wrote:
| I spent a few minutes at an Apple Store holding an iPad Pro
| with tandem OLED, and I couldn't perceive any difference with
| the iPad Air right beside it.
|
| (The even more expensive nano texture option was worse. It
| simply felt blurry.)
| theshackleford wrote:
| That would be a worse case scenario. The Apple stores are
| incredibly brightly lit, and you'll be hard pressed to notice
| wining isn't differences between any display type in such an
| environment.
|
| These displays and their content are intended to impress in
| media viewing situations in which you'll light control
| accordingly. They'll still look good outside of that, but
| they offer so much more when you want to dim the lights and
| kick back with one on the couch with a movie or whatever.
|
| Now if I could only get one in a size I cared about, I could
| be rid of LCD permanently. Alas, I doubt I'll see this in a
| size suitable for what I want it for in less than 5 years or
| more.
| MBCook wrote:
| There have been rumors of the MacBook Pros moving to OLED
| for a few years now.
|
| Seems unlikely they'd redesign with something worse than
| the iPad Pro.
|
| I wonder if they're waiting for yield issues on larger
| panels or if it's just pure cost at the moment.
| MBCook wrote:
| The amazing thing about the nano texture is how it absolutely
| kills reflections compared to the normal option.
|
| I agree there is a sharpness sacrifice to get there.
| lispm wrote:
| One needs to use them in their personal lighting situations,
| not in a store.
|
| I have both the current and prior iPad Pro version. IPS+Mini
| LED and the Tandem OLED. The IPS version was already great.
| The Tandem OLED is generally better, but often not by that
| much. It's also a bit brighter. Both are quite a bit better
| than the normal iPad displays.
|
| I've seen the nano texture version of the Tandem OLED.
| Reflections are much less, but in brighter surroundings, the
| image is not that dark. But again, it all depends on the
| personal lighting situations.
| ksec wrote:
| >"Once blue PHOLED finally becomes available in 2025 or 2026,
| most display makers will integrate them in their OLED displays
| (single or tandem) and deliver further improvement in lifetime,
| brightness, and efficiency," Virey said.
|
| This is much more important improvement than Tandem OLED.
| Although I dont think I could see that on an iPhone before 2030
| judging from how slow Apple adopt technology.
| tiffanyh wrote:
| > how slow Apple adopt technology.
|
| Aren't they only slow to adopt new _display_ technology.
|
| Everything else they either lead or are on par with, no?
|
| Biometrics, Spatial Audio, health sensors, SOS phone calls,
| etc.
| repiret wrote:
| Apple was also first to bring multitouch and high DPI
| displays to consumers.
|
| They were slow with OLED, and they have also been slow with
| each new generation of cell phone radio standards.
| MBCook wrote:
| The early ones likely weren't up to their quality
| standards. Then at some point they may have decided to hold
| it for the X redesign.
|
| The main issue with cell phone standards appears to be
| power. Apple doesn't like using radios that use up so much
| power the user has to turn them on and off to manage things
| the way early 4G or 5G android phones were set up. They
| seem to prefer to wait until a lower power version is
| available that they can leave on all the time without
| significant issue.
| petepete wrote:
| > first to bring multitouch and high DPI displays to
| consumers
|
| If you discount the LG Prada, then yeah.
| Toutouxc wrote:
| That one was capacitive, but didn't do multitouch. So no
| pinch to zoom, which was one of the most wow things the
| first iPhone did.
| kurthr wrote:
| Agree, and once you can lithographically pattern QD in for
| Red/Green it'll just be one layer of Blue PHOLED underneath.
| Cheaper and matched wear-out so burn-in is less visible. These
| aren't huge changes, but the steady pace of improvements may
| just make the other technologies irrelevant in mobile devices.
| TVs and wearables still might go to microLEDs, but only if the
| costs can come down.
| 14 wrote:
| I don't have much to add to this conversation except that what a
| lot of people don't realize it that 2k, 4k, or 8k, tv means very
| little in terms of how nice the picture looks. Yes to a point
| that is important but I always tell people the panel technology
| is way more important. Some TV's look absolutely lifelike, maybe
| beyond life like and some sort of hyper-reality. It is like a
| massage on your eyes watching things on a superior TV. But those
| TV's cost a lot. A brand I found that is very good for the cost
| is the HiSense ULED TV's. Costco has them. I love the picture for
| the affordable cost. Not the best but pretty great. I have an led
| monitor beside my HiSense TV, both hooked up to my pc and I ran a
| pure black YouTube video on both side by side and the difference
| is huge. The led monitor looks grey and is clearly lit up from
| the back light. The HiSense is absolutely pitch black dark zero
| light emissions. There is no real point to this post other then
| to say I am happy with my TV, it definitely is great for the
| cost.
| rfwhyte wrote:
| I love OLED panels and their amazing color reproduction, but I'll
| never buy another device that uses them ever again if I can help
| it. My current laptop developed pretty horrific burn-in after
| just a couple years of regular use, and there wasn't really
| anything that could be done about it, as the burn-in is comprised
| entirely of my taskbar and the UI elements of my web browser
| which is far and away my most used program / application and
| likely is for the majority of other laptop users as well. I'm
| sure they're fine for TVs where content is played "Full screen"
| 99% of the time, but for phones or PCs where there are common OS
| or web browser UI elements displayed on the screen the majority
| of the time the user is using their device, they just don't make
| sense.
| Citizen_Lame wrote:
| Oh, no.
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