I'm looking forward to it. I'm happy with the OLED panels in my phones but with how long static elements are visible on my computer monitors and TVs I haven't been able to justify buying OLED for those with how even the best can still exhibit burn-in. Once there's microLED monitors and TVs with performance equivalent or better than current QD-OLED panels I'll be buying them immediately.
My oldest OLED TV will turn 6 in August and has exhibited no burn-in.
I think it ultimately comes down to what you're watching. You're likely to experience burn-in if you watch something with a persistent banner like 24 hour news.
For example, my 2 year old LED VA Panel monitor already has burn-in where the task bar is displayed.
And yeah, I've experienced image retention on non-OLED screens. the LG-made 2560x1440 IPS panels that used to get used in 27" iMacs would after a few years start exhibiting image retention, though it'd at least fade if the static elements that sat long enough to cause retention were hidden. I think this was caused by the heat generated by the computer part of the iMac though, because the Apple Thunderbolt Display that used the same panels never develop the issue even after a decade+ of usage. I also haven't seen it happen on any other IPS panels I've owned.
You'd think modern desktop OSes would allow subtle shifting of persistent UI elements by a few pixels to avoid burn-in. LineageOS already does this
If you want to rotate the task bar or dock or menu bar around all four edges of the display every day then maybe, but that'll be hell on your habits and muscle memory.
I think for normal TV usage it is a non issue. The only times I have heard it being a problem is when someone leaves their TV on for a week for their cat or something.
None of the materials are expensive.
The risk is that they patent that process and we have 20 years to wait till we get cheap screens.
That is a deal breaker for many.
> Digital pulse-width modulation is well-suited to driving microLED displays. MicroLEDs experience a color shift as the current magnitude changes. Analog schemes change current to change brightness. With a digital pulse, only one current value is used for the on state. Thus, there is no color shift that occurs as brightness changes.
This bandgap corresponds to the photon energy of the emitted light as electrons get excited due to the applied voltage as electrons are excited to the conduction band and then relax back to the ground state giving off light.
The bandgap energy changes as a function of temperature. The primary reason for this is that the lattice constants increases as temperature increases. This causes the bandgap to decrease, meaning the energy of the photons is less giving a longer wavelength.
The opposite effect is also true, cooling a LED will lead to a shorter wavelength. Here is a cool video showing the effect![1]
Increasing the current through the LED may change the temperature by a little bit but you need large temperature changes to have any effect.
The temperature has a much greater impact on the intensity of light emitted by the LED. I have seen a typically 1% decrease in intensity per degree C for the LEDs I have tested. This is the effect that matters most when using RGB leds as if the red led gets dimmer cause it is hot, than the green or blue, it will be seen as a color change, even though the center wave length of its emission is unchanged.
I mostly just wanted to share things I have learned about LEDs over the past year or two and your comment gave me a good opportunity!
I could plausibly see some color shift at close to bandgap voltage if there isn't a perfect uniformity in bandgap across a diode, inconsistent or even just gaussian distributed doping would result in some holes being preferentially excited if there isn't a sufficient surplus V?
[1] https://www.researchgate.net/publication/250139383_Dependenc...
Really? How does JPEG get away with severely degrading color information when compressing then? I thought it’s brightness that we are sensitive to.
In this regard, AMOLED displays have a strong disadvantage. If you feed less voltage to the organic diodes, not only do they limit their brightness, but their color also changes, so that there might suddenly be visible differences in the color reproduction.
Based on that article, non-PWM based solutions seem to be very hard to implement for smaller devices anyway.
Apple has already unfortunately abandoned PWM flicker free displays on almost all their devices. So I have no reason to believe this will change.
[0]: https://www.notebookcheck.net/PWM-Ranking-Notebooks-Smartpho...
The bigger challenge here is pixel architecture, but if apple is actually slicing up wafers into a couple million pieces to build these displays, they are already sort of moving away from the typical TFT architecture and may be able to integrate more complex pixel drivers, potentially including things like touch sensors directly onto the pixels.
I don’t understand what you mean with the GPU. It is has no information about the exact color of the LED.
The shift in wavelength is primarily determined by temperature and current, and they work in opposite directions so sort of cancel each other out. And in any case, we're talking about well-characterized shifts on the order of a few nm over the operating range. The eye's cones are broadband, so you're not going to notice wavelength shifts, especially compared to the brightness variations over the same range.
This is a big deal for white LEDs because you have no control of the resulting color temperature (the phosphor emission and blue component wholly determine the output), but for an RGB structure, you have pixel-level control over each component.
As to binning LEDs that works because it is constant. You can calibrate it once and done. But if you change the brightness by changing the current, it means your calibration is out of wack. Perhaps you can make a calibration at multiple current settings, but that seems inconvenient when using PWM will achieve the same thing.
I'm assuming the three microLED frequencies (RGB) are chosen to maximize gamut, and that the frequency drift effect is much larger than whatever distance they might be away from perfectly optimal.
If you have a display 1000 pixels tall, then the brightest LED's are on for 1/1000th of the time.
And manufacturing limitations mean you can't easily have those per-pixel while still keeping the whole thing cheap.
“can’t easily” seems to imply it is possible. If that’s true, Apple, with its deep pockets, should be able to do it.
Also, I don’t think Apple will be bothered much with “keeping the whole thing cheap”. They will want to prevent it from getting expensive, but likely will accept intermediate costs if the result is much better.
You're thinking of MiniLED, which is just better LEDs behind an LCD.
MicroLED is a whole different ball game, with no LCD at all. It's just red, green, blue LEDs, one for each pixel.
MicroLED is more akin to OLED where each pixel is self emitting. MicroLED is almost the holy grail of displays and will more than likely obsolete MiniLED.
Compare that to Intel's Optane, the elusive PCM memory technology which finally arrived to take out NAND Flash. Sure, it was faster than Flash, but it was also massively more expensive. It wasn't worth it for most people. So Intel recently discontinued it.
The same could happen for Micro LEDs. It isn't clear whether their quality advantage over OLED is worth a much higher price. Their main advantage over OLEDs (higher max brightness) doesn't seem too relevant anyway.
Source: Where I work is tooling up to start producing uLED products for SLA 3D printing. UV uLED + LCD filter all in one. I'm having to teach them how to utilize LIFT.
Intel Optane is barely faster than flash — roughly 3x (for 4k random read) compared to the fastest Samsung SSD [1].
Optane was a failure because it failed to deliver the promised result. Intel would have never poured money into a new technology only three times faster than an existing technology. I recall initial promises were RAM-like speeds.
If Apple is able to spit out 200 million of these screens in a year, I have a very hard time imagining what ingredient could go into the production causing a greater per unit price than a Samsung display.
... and the maximum brightness advantage of micro LEDs may be similarly (un)impressive.
> Optane was a failure because it failed to deliver the promised result.
No, it only failed because the performance/price ratio wasn't good enough compared to NAND flash. That's exactly what I was saying: Both performance and price have to be considered.
> If Apple is able to spit out 200 million of these screens in a year, I have a very hard time imagining what ingredient could go into the production causing a greater per unit price than a Samsung display.
Replace "Apple" with "Intel", "screens" with "Optane disks" and "Samsung Display" with "Samsung Semiconductor", and you see that this argument doesn't work.
There's something incredibly realistic about highlights being super bright, I think it's going to look more like a window than a TV.
However, other than some breathless press-releases a few years ago I haven't heard anything happening recently, so it's possible the technology didn't pan out.
https://www.channelnews.com.au/new-samsung-lg-premium-displa...
Now we just need to make them...