
Mini-LED, Micro-LED and OLED displays: present status and future perspectives - zeristor
https://www.nature.com/articles/s41377-020-0341-9
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baybal2
One elephant in the room that wasn't mentioned:

Samsung is years ahead of anybody with self emissive quantum dots, and new
types of TFT matrices.

Samsung can commercialise cheap self emissive qdots within 2-3 years if they
want, and then microleds will be automatically obsolete, probably with
exception of displays for VR goggles.

Samsung has another ace in the sleeve they don't get public about: they know a
trick how to grow GaN leds on amorphous substrates. Their papers from 2012
showed them being in a quite advanced stage already.

If they can get advanced with the later, they can not only bust the display
market, but pretty much everything LED.

If LEDs can be grown on a much cheaper, and less finicky substrate than
sapphire, we can talk about them getting n-times cheaper.

~~~
gruez
So if samsung is so ahead, why aren't we seeing it in present displays? Is it
because it's too expensive? Or are they hoarding it for a rainy day?

~~~
jandrese
If the technology is so much better it doesn't make sense to horde it. Put it
out there and dominate the market. The longer you sit on it the longer you
give your competitors to develop similar or better alternatives and waste your
advantage.

The most likely answer is that they can't be manufactured at scale for
reasonable price points currently.

~~~
baybal2
You should probably tell that to Mr. Lee :)

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gtm1260
Very excited for the new display technologies on the horizon. Sure, current
Tv's and Monitors are pretty good, but I can't wait to see the picture quality
that we're going to get. Linus Tech Tips has a pretty easy to understand video
(much higher level though) on this stuff. He goes into the manufacturer
roadmap which I think is pretty good to know in terms of the time horizon for
these technologies.
[https://www.youtube.com/watch?v=RTTiQeXXrhI](https://www.youtube.com/watch?v=RTTiQeXXrhI)

~~~
spuz
Thanks, that was an excellent video.

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Sloppy
This report doesn't seem to mention burn-in directly. This is IMHO the
achilles heel of the current crop of OLED TVs. This is a very hidden fact.
Everyone talks about how great they are and say they're the hands-down winner
among popular TVs but after having owned one for 2 years it displayed horrible
burn-in. They are fantastic while they last then they are awful. It would be
nice to know how mLeds, uLeds, and the new tech sizes up for burn-in.

~~~
Shivetya
Seriously it is not. I have a LG C9 and bought it after recommendation from
friends who game on theirs. If you are going to leave it on the same screen
all day long there are better choices, like having it on a new station that
has a permanent ticker or channels which insist on a permanent logo.

You have to go out of your way to force burn in, there has been some good 3rd
party testing [0]

Oh, as for the TV, the colors are astounding and its thinness is just a bit on
the silly side, seriously from one third on up from the base it is as thick as
iPad

I expect micro LED to over take it one day but for now if you are a movie
aficionado there is no subsistute, this is especially true when dealing with
letter boxed movies as there is no bleed into the black borders

[0] [https://www.rtings.com/tv/learn/real-life-oled-burn-in-
test](https://www.rtings.com/tv/learn/real-life-oled-burn-in-test)

~~~
flyinglizard
C9 is still pretty new, isn’t it? My C6 burn in is awful.

~~~
devonkim
I have a C7 and after running it maybe 4-5 hours / day average I haven't seen
burn-in. If anything, not watching cable news is an improvement to our lives
and when I eventually upgrade I can use it for gaming and not mind that the
burn-in is happening for anything remotely serious. LG's input and panel
latency with OLED is quite an exception and is one reason I paid for such a
panel.

~~~
brokenmachine
Another C7 user here checking in, had it for almost 3 years now - about
5hrs/day of mixed use TV/movies and it's still awesome.

No sign of burn-in and I check it with color slides every few months. I think
the C6 panels were much more prone to burn in than C7.

Some people with C7 panels had problems with a bug where the automatic
compensation program does not run which greatly accelerates burn in, but I
believe LG is replacing TVs for people who get that.

My C7 looks absolutely stunning with good sources 4k/HDR.

I'm happy with my purchase every day and would never think about going back to
crappy LCD.

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fabian2k
I'm somewhat disappointed in the lack of progress on OLEDs the last few years.
For TVs, LG is the only company that actually produces panels, every single
OLED TV uses their panels. And even though there are new models every year,
all OLED TVs of the last few years use the same old panel.

~~~
ksec
That is not true at all. While LG is the only OLED TV panel manufacture on the
market, they have been making progress every year in their WOLED panel. And
many more technical innovations in the pipeline. And older panel drop in price
as they improve yield, that is why you start seeing affordable OLED. They
differ in colour accuracy, refresh rate, QA, max brightness etc. To say they
are the same panel every year give very little credit to LG's WOLED
engineering.

~~~
zmarty
Max brightness progress is marginal at best for the past 4-5 years.

~~~
darkteflon
I’ve never looked at my C9 and thought “I wish it was brighter”. Does seem to
bother some people though so YMMV.

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muska3
One major question I have: how come we haven't seen any innovations to desktop
monitors? Most of the innovations come first to TV's and smartphone displays.
It seems like the pace of desktop monitor innovation is slower.

~~~
stubish
I'm more interested in why TVs and monitors are considered separate markets.
The difference between a TV and a monitor is software, and maybe a display
port input for the highest resolutions or refresh rates. This large TV I use
as a monitor is great, apart from lack of suspend and an annoying banner that
pops up every time the resolution or audio inputs change. And much cheaper,
assuming I could find a 43" 4k computer display at all in my region.

~~~
darkteflon
Spot on. I switched to a 40” 4k Phillips VA panel (BDM4065) a few years back
and can’t imagine switching back to anything smaller. Quite cheap, too. Might
not be suitable for colour-sensitive work but perfectly serviceable for VS
Code and a browser.

------
muska3
Very interesting. One thing I don't fully understand is the difference between
mLED and uLED. As I understand, mLED have a an array of separately
controllable backlights, but what exactly is uLED?

~~~
xt00
miniLED means that they place small LED's that are basically equivalent to the
present level of LED technology behind an LCD array. So instead of the normal
LCD backlight design where you shoot LED light sideways from the LCD module
edge into a series of films that direct the light from the sideways direction
to the normal viewing axis direction, the LED's are placed in a regular grid
behind the LCD array itself, but you need a large number of these mini LED's
to cover the entire surface of the display panel, as well as some diffusers to
reduce hotspots. The main advantage is that the peak brightness you could get
using this technique could be quite high. And in a sense you can get high
contrast ratios by selectively dimming certain zones. So comparing two zones
the contrast can be quite high, but comparing within a zone the contrast ratio
is still the same as a normal LCD. uLED means that you are attempting to place
one LED chip for every pixel. Equivalent to how they build those large LED
signs at sports arenas. In the smart phone situation, the LED chips would need
to be crazy small -- on the order of say 10-50 microns -- so the name uLED
(microLED) makes sense.

~~~
zokier
FALD has been a thing long since before mled was spun up. As far as I can
tell, mled is just a marketing term for slightly higher number of dimming
zones.

~~~
nitrogen
If the number of dimming zones approaches the number of pixels, that could
make a pretty big difference.

~~~
zokier
Approaches, but very slowly. Jumping from 1000 zones to 10000 zones might seem
impressive, but it is still pretty far cry from 8+ million pixels of a typical
4k screen.

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xt00
One problem I see with microLED's taking off is that the primary parameter the
microLED design helps with is power for a given brightness. If the uLED tech
costs more than a normal smartphone display (seems to be likely to be true for
some time) then getting improved power efficiency I'm not sure would cause a
big wave of adoption similar to what has happened with OLED over the past 3-4
years. OLED compared to LCD tends to have both better color gamut and contrast
ratio, and when using dark mode UI's the power savings can be pretty high.
Hard to see how uLED would be able to differentiate itself from OLED except
for showing HDR images in a power efficient way. I'm probably missing
something else about why uLED is good though?

~~~
baybal2
> I'm probably missing something else about why uLED is good though?

The fancy VR/AR goggles category. It's pretty much the one, and only way to
make battery powered goggles usable outdoors.

The one who gets there first with patents wins the game.

~~~
corey_moncure
Also the "doesn't degrade/burn-in/shift whitepoint after a year of ordinary
use" category.

~~~
s9w
This is the main concern I think. It's what's always being brought up with
OLEDs.

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sroussey
Why not sandwich two LCDs together — one B&W lower resolution, and then the 4K
color one? Align them so one B&W pixel switches for the three sub pixels of
RGB.

~~~
randyrand
People want HDR. hard to make a brighter display by removing _more_ light.

~~~
TheAdamist
They also want better black levels that oled provides. Its relatively easy to
get lcds bright, but then the black level suffers.

But yeah, ive read these dual layer lcds are horribly inefficient power wise.

~~~
dungdang
how do you get blacker than 'no light emitted' when the oled pixel is off? in
other words, how does a light bulb in your desk lamp produce less light than
zero?

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rado
Please already replace the LED LCD of the last 20 years, whose backlight bleed
is ridiculously bad.

