While this subject could be considered controversial, it isn't trying to suggest that OLED doesn’t remain an impressive display technology. However as the dust settles on CES, there are some interesting questions to be asked about the future of OLED.
The story so far...Since its launch back in 2012, OLED has proved a hugely successful gamble for LG. The self-emissive display technology has received countless awards and plaudits, while evolving to reflect changing video delivery standards, and being adopted by almost every TV manufacturer.
It has also become the display of choice for many TV enthusiasts, thanks to its wider viewing angles, deeper blacks and incredible contrast ratios. In fact the LG C9 picked up Best Overall TV in this year's Editor's Choice Awards.
Related: LG C9 OLED 4K TV Review
However looking at the new 2020 OLED line-up, it seems the technology has reached its peak. This specifically relates to the capabilities of the panels themselves, rather than any of the other features found on a modern TV. The smart platform, format support, input lag and even the processing are all essentially agnostic and could be applied to any display technology.
OLED itself is a particularly good example of this phenomenon because all the panels are made by LG Display but various manufacturers, including LG Electronics, Panasonic, Sony, Philips and Hisense add their own features, cosmetics, sound systems and processing to the units they buy in.
Related: Best TVs of 2019 – Editor's Choice Awards
Panasonic GZ2000So, if we're not concerned about features, what's the issue? Let’s take the Panasonic GZ2000 as an example. It won no less than three categories in this year’s Editor’s Choice Awards, and it's fair to say this TV represents the apex of OLED consumer performance, not just this year but in any year
Panasonic developed the bespoke OLED panel used in the GZ2000 in conjunction with LG Display, and the goal was to make a consumer TV with a performance matching as closely as possible the Sony BVM-X300 professional OLED monitor.
To put this ambition into perspective, the Sony BVM-X300 uses a 30-inch RGB OLED panel (ironically made by Panasonic) that can reach 100% of the DCI-P3 colour space, hit a peak brightness of 1,000 nits, and costs £35,000.
Incredibly, Panasonic’s Custom Pro OLED panel came remarkably close to achieving these goals. Based on Phil’s review, the GZ2000 delivered exceptional screen uniformity, a peak brightness of nearly 900nits and just under 100% of DCI-P3.
Related: Panasonic GZ2000 OLED 4K TV Review
How bright can OLED go?In developing the custom panel used in the GZ2000, a lot of Panasonic's efforts went into increasing the peak brightness in a manner that didn't require additional external cooling. It would seem that under these conditions, the maximum peak brightness is 1,000 nits. In a recent interview with AVForums, Philips’s picture guru Danny Tack suggested that OLED is very close to its peak in terms of brightness, with possibly a 10% increase available. The fact that Panasonic's new HZ2000 uses the same basic panel as last year would seem to confirm this assumption.
Related: Listen to the Danny Tack interview
Of course, that isn’t necessarily a major limitation because much of today’s HDR content is graded at 1,000nits (or less), and content that is graded higher can be tone mapped to match the capabilities of the display. In addition, the pixel precise nature of OLED allows it to deliver tiny specular highlights in a way that local dimming can never fully achieve.
Related: What is tone mapping?
However, as Phil discovered in his review of the GZ2000, pushing the brightness to the panel’s limit can result in artefacts such as posterising around very bright objects. And, of course, due to its self-emissive nature, OLED can only produce a maximum of 200nits on a bright full field image before the ABL kicks in. However, the introduction of Quantum Dot OLED might allow manufacturers to increase full field brightness to 300nits.
What that basically means is that not only will OLED never hit the peak brightness levels of 4,000 and 10,000 nits that some content is mastered at, but it can never hope to deliver the entire HDR colour volume, which is a combination of the colour space and overall brightness expressed as a three dimensional space.
Related: What is Colour Volume?
OLED struggles to deliver a large colour volume in part because it's not that bright, but also because as a multi‐chromatic display it achieves a wider colour gamut by using combinations of white and secondary colour channels. However, these displays can lose both lightness and colour saturation at brighter levels. This reduced colour volume is a side-effect of multi‐chromatic displays, but doesn't effect trichromatic (RGB) displays to the same effect, making them better at reproducing larger colour volumes.
Related: What is High Dynamic Range (HDR)?
What about wider colour gamuts?Colours are an area where it would seem that OLED has reached its limit as well, although to be fair, achieving 100% of DCI-P3 is sufficient at the moment because no content is created using Rec.2020. However, that will change over time and manufacturers will want to expand the colour space of their displays to get closer to the Rec.2020 standard. The introduction of Quantum Dot OLED might also help widen the colour gamut, but as it stands OLED doesn’t appear able to cover more than DCI-P3.
Related: What is Wide Colour Gamut (WCG)?
How will OLED panels age?OLED was developed during the era of standard dynamic range (SDR), which is based around a peak brightness of 120nits and the Rec.709 colour gamut. Since then, LG Display has done a remarkable job of pushing the technology to embrace recent advances, such as an increase in resolution to 4K and then 8K, along with the introduction of HDR.
However, the increased brightness of the latter does raise a number of questions relating to the long-term use of OLED, starting with what effect pushing the brightness of the panel will have on its lifespan. OLED has always had a shorter effective lifespan than LCD, although it's certainly long enough to cover the average replacement timescale for a TV of five to ten years.
Just how long that effective lifespan turns out to be remains unknown because OLED is still a relatively new display technology, In fact, it has only really been a mass market product for about five years, so it will be interesting to find out what effect, if any, HDR has on OLED panels as they age.
What about screen burn?OLED’s greatest strength lies in is its ability to create absolute blacks and deliver pixel precise details thanks to its self-emissive nature. But this is also its greatest weakness. OLED can suffer from image retention, and even screen burn in extreme cases. Pushing the panel brightness to deliver HDR images only exacerbates this issue. The manufacturers employ various features to mitigate the risk, including screen savers, pixel shifting, and screen washing while in standby, but it remains an issue.
AVForums members have conducted numerous polls on the subject of screen burn over the last few years and the results make for interesting reading. Looking at an average of polls conducted over the last two years reveals that 15% of 2015 OLED owners have reported screen burn, but that figure suddenly jumps to 30% for 2016 models. Since then the various safety features that manufacturers have added appear to be working because only 8% of 2017 owners reported screen burn, and that's down to just 4% among 2018 models.
How much impact lifespan has on the vulnerability of an OLED to screen burn remains to be seen, but it's interesting that 2016 is when OLED really arrived as a mass market product. In that year, a total of 223,000 OLED TVs were sold in Europe, compared to 88,000 in 2015. Since then sales have doubled each year, so if lifespan and screen burn are connected, then any correlation should become obvious over the next couple of years.
As to what is causing screen burn, once again AVForums members have proved useful in cataloguing the main culprits. It appears that news banners are the biggest cause, followed by apps, channel idents and gaming. This is understandable because all of these are largely outside of an owner's control. You can hardly stop a TV channel from using an identifying logo, and if you're a gamer you really need that heads-up display in order to actually play the game properly.
Screen sizes are getting biggerThere is a definite trend towards larger screen sizes, and as these increase it could be an issue for OLED. It's easier and cheaper to mass produce large-sized LCD panels than it is for OLED. While there's a price premium for all screen sizes of 75-inches and larger, regardless of display technology, this appears to be more significant for OLED. As consumers choose bigger and bigger screen sizes, this could prove an issue for OLED.
8K is here to stayThe rise in popularity of really large screen sizes goes hand-in-hand with the introduction of 8K resolution. We can expect to see a lot more 8K TVs in 2020, and this is another area where OLED struggles. In simple terms, it's incredibly difficult to squeeze 33 million self-emissive pixels into a panel. Although LG Display did show a prototype 65-inch 8K OLED at CES 2019, the only 8K OLEDs released to date have used screen sizes of 77 inches and larger, with equally astronomical price tags.
Related: What is 8K?
What next for LG?Up until now, LG has largely had the OLED manufacturing market to itself, and thanks to significant investment in the technology, LG Display has enjoyed a virtual monopoly. However, things are definitely about to change, with increased competition from Chinese manufacturers like BOE, the introduction of Quantum Dot OLED, and a new inkjet printing process that will significantly reduce the cost of making OLED panels.
Related: Chinese manufacturer BOE demonstrates new OLED inkjet printing process
The former is not good news for LG Display, which struggled last year, barely making a profit in the first quarter of 2019 and making losses of $469 million and $377 million in the second and third quarters respectively. These losses primarily relate to difficulties in the LCD market, but increased Chinese competition in the OLED market isn't going to make things easier.
While it's still a few years away, the development of Quantum Dot OLED certainly has potential, increasing the overall brightness and colour gamut of panels, and improving their efficiency. Unfortunately for LG, it will also have competition in this area, with arch-rival Samsung investing heavily in Quantum Dot OLED.
In response to all this, LG Display is looking to diversify its current OLED portfolio, with transparent and rollable models, as well as more 8K panels. There's also the new 48-inch LG CX and Sony A9 4K OLED TVs, which are designed to meet consumer demands for a screen size smaller than 55-inches.
However, it's the inkjet printing method that provides the best opportunity for LG Display, allowing it to manufacturer OLED panels at lower costs and in increased numbers. The result will be a chance to move OLED from the premium end of the market and into the mid-range, allowing it to transition into a genuine mass-market product.
What does the future hold?If OLED does start moving down the price range, which display technology offers the best long-term potential at the premium end of the market?
Well, there are a number of display technologies on the horizon, but before discussing them it’s worth mentioning good old LCD. When OLED first arrived, many enthusiasts wrote LCD off as yesterday’s tech, but instead it has reinvented itself with remarkable success.
In fairly short order, LCD has embraced 4K and 8K, larger screen sizes, wider colour gamuts, and increased peak brightnesses. The production capabilities and economies of scale afforded LCD has also enabled manufacturers to deliver these features without a significant increase in price.
Related: What are Quantum Dots?
The use of quantum dots has also allowed for wider colour gamuts and brighter and more efficient backlights. As a result, these TVs can deliver superior colour volumes that combine the wider gamuts and brighter overall images.
In the past OLED had a clear advantage over LCD in terms of blacks, contrast ratios and viewing angles, but Samsung, in particular, has recently made remarkable strides in these areas. The Samsung Q90R QLED 4K TV was another big winner in this year’s Editor’s Choice Awards, and it's hard not to be impressed with its performance, which often looks like an OLED but brighter.
Related: Samsung Q90R QLED 4K TV Review
At CES 2020, TCL announced advances in its Mini LED technology. This essentially equates to an LCD panel with a direct LED backlight composed of tens of thousands of LEDS and thousands of dimmable zones. The results can be very impressive, but implementing this approach can sometimes be quite expensive.
Dual LCD technology is another possibility. This combines two LCD panels – a 4K full colour outer panel and a 1080p dimmable monochrome inner panel that modulates the backlight, basically creating millions of dimming zones. This technology is being developed by Hisense for consumer TVs, and by Panasonic as a professional monitor solution.
Panasonic's prototype Dual LCD monitor has been christened the "MegaCon", which stands for mega contrast, and it's designed as a replacement for the Sony BVM-X300, which is no longer manufactured. Panasonic promises its new Dual LCD professional monitor will deliver pixel-level dimming, a 1,000,000:1 contrast ratio, 100% of DCI-P3 and an indefinite peak brightness of 1,000nits. The only possible downside to this approach is the technology might struggle to reach a peak brightness of more than 1,000nits, which puts it in the same boat as OLED.
Related: The Best TVs and Projectors of IFA 2019
Dual LCD certainly has potential, with the prospect of a display technology that is relatively easy and cost-effective to manufacture but has the ability to deliver wide colour gamuts, superior contrast ratios, and high peak and full field brightness levels. It also won't suffer from screen burn.
There is however one more display technology that offers the possibility of the best of all worlds – Micro LED. This uses a panel where each pixel is composed of microscopic red, green and blue LEDs, and while at present it's neither easy nor cost-effective to manufacture, it has remarkable potential
The fact that every pixel is self-emitting means you can get perfect blacks, fantastic shadow detail, incredible contrast ratios and very wide viewing angles, just like an OLED. However the use of LEDs also means there's no danger of screen burn, and this technology has the potential of wider colour gamuts, and increased brightness on both peak highlight and full field measurements. Theoretically, this approach could result in displays capable of reaching Rec.2020 and hitting 10,000nits of peak brightness.
Related: What is Micro LED?
At CES 2020 Samsung launched its first fixed screen Micro LED TVs, including a 75-inch model. This new range is possible thanks to Samsung's recent advances in production techniques, resulting in an LED chipset that is smaller, cheaper and more efficient. This new LED chipset is 15 times smaller, with reduced light leakage and improved current and beam control. The smaller chips allow for an optimised backplane that uses a TFT substrata rather than a PCB, which vastly improves the integration, wiring and tolerance of the modules. These first Micro LED TVs won't be cheap, but it does mean the technology is about to become a viable consumer product.
These days tech changes fast in the world of TV. The first 4K TVs were only released seven years ago, and they had an 85-inch screen sizes, no HDR and cost over £20,000. So who knows what will be on offer in another seven years?
So what do you think? Has OLED reached its peak, or do you think there's more to come from the technology? And now CES has finished, what are you looking forward to in 2020? Let us know your thoughts in the discussion thread.
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