With the rapid evolution of televisions over the past few years, we've seen new technologies from 3D to Smart content to 4K Ultra HD resolution all become established features. And while it's been a slow-burner for a few years, we're now finally seeing another one – and that's OLED.
The first OLED TVs started to hit the shelves in 2013 but they were few and far between, and expensive. These sets gave us a glimpse at what all the fuss was about, with a revolution in picture quality and slimline design promised - a 4K OLED TV became the holy grail in many AV enthusiasts' minds.
But that promise appeared to wane somewhat during 2014. First there was news that Sony and Panasonic had ended an OLED TV production partnership in order to focus on 4K Ultra HD TV production, and at CES that year LG was the sole manufacturer to show off a new range of OLED models.
2015 has seen some progress. We've seen new LG OLED TVs this year (but none from Samsung), while Sony is "looking into OLED". We also reviewed the first curved 4K OLED TV and have seen plenty of OLED smartphone screens, such as the Samsung Galaxy S6 Edge. LG Display, one of the key panel manufacturers, is also improving the efficiency of the OLED production process.
OLED, therefore, looks like being a viable concern for some of the consumer electronics industry going forward. So how does OLED technology work, what's so good about it and which are the best OLED TVs to buy? We explain all that and more.
OLED – what is it?
OLED – or Organic Light-Emitting Diode – is a type of display technology that makes it possible to create even slimmer TV sets than LCD or plasma, while at the same time making them more efficient and eco-friendly too. To give you an example of just how slim, there's this LG wallpaper OLED that is just 0.97mm thin.
Here’s how the technology works: an organic, carbon-based film is placed between two conductors and an electrical current is passed through, which causes it to emit light. This differs from LCD TVs, which require a backlight to create their brightness. OLED pixels are self-emissive and generate their own light.
There are two types of OLED technology, Passive-Matrix (PMOLED) and Active-Matrix (AMOLED). Active-Matrix requires electronics to switch each pixel on or off individually, which is better for displaying motion and therefore the type used for OLED TVs.
So far, only two manufacturers have launched OLED TVs in the UK – LG and Samsung (the latter back in 2013). But there is a crucial difference between the OLED technologies used by LG and Samsung, relating to the sub-pixel structure. In its OLED TVs, Samsung uses a traditional red, green and blue (RGB) pixel structure with no colour filters, just like you’d find on a plasma.
By comparison, LG OLED TVs use WRGB 4-colour pixel technology, which adds a fourth white sub-pixel. White light is shone through a colour filter to create the red, green and blue sub-pixels. LG says this results in a brighter picture.
OLED TV benefits
OLED technology has several advantages over LCD and plasma technology. First there are the physical benefits – OLED sets are lighter and thinner than LCD due to the lack of a backlight.
But of greater interest to most of us is the picture quality. Because OLED pixels emit light directly, viewing angles are much wider, plus colour and contrast stay the same from as far as 90 degrees off centre.
And because each pixel can be turned off individually, OLED TVs can do their best to deliver an absolute black and infinite contrast ratio – the Holy Grail for picture purists everywhere. OLED pictures should also be brighter and can achieve response times of less than 0.01ms, which practically eliminates motion blur.
OLED TV problems
It’s not all rosy in the OLED garden however. OLED is extremely expensive to produce and therefore to buy – LG’s first 55in set, the 55EM970V cost £10,000 at launch and its 55EA980W sold for £8,000. Samsung’s first set, the KE55S9C, sold for £7,000. Prices have thankfully come down, though, witness the LG 55EC930V for under £2000.
In its infancy, OLED production had a relatively low yield, which meant that for every set fit for sale, a high number were consigned to the scrapheap. This made the technology expensive - it's improving this aspect of the production, which is helping bring costs down. Though it remains a premium TV option for now.
Another of OLED’s problems concerns the pesky blue pixel. Because the OLED material used to make blue light deteriorates more quickly than red and green, its lifespan is shorter and over time the colour balance could be affected.
Samsung’s solution is to make the blue pixel twice the size of the other colours while LG’s WRGB system should side-step the problem, but it remains to be seen how this issue will play out in the long term.
More after the break
The OLED TVs launched in the UK by Samsung and LG feature curved screens. There has been much scepticism over this – indeed we saw it as both a plus and a minus in our review of the first Samsung curved OLED TV.
“It’s an outlandish idea,” we said, “not unlike a concept car: it’s very cool, even if it might not be entirely practical”. The curve also means Samsung’s set can’t be wall-mounted.
Manufacturers believe the curve enhances the viewing experience. Samsung says it provides “depth to the content displayed for a more life-like viewing experience”, and delivers an “immersive panorama effect". LG has said the curve is there to “remove the problem of screen-edge visual distortion and detail loss”.
Marketing ploy or a genuine viewing enhancement? Whatever your take, it's not just OLED screens that have caught the bug - we've now seen curved 4K LCD/LED TVs too, such as the Samsung UE55JS8500.
The same logic applies: it can make for a more immersive experience, and the TVs look great, but they're not ideal for multiple people watching at the same time as there is a smaller sweetspot for the best picture.
Curved phones have become a reality too, with the launch of the LG G Flex, G Flex 2 and Galaxy S6 Edge, and they could actually make more sense than curved TVs. Read our opinion piece explaining why we think so here.
4K OLED? Bendable OLED?
Not content with the introduction of OLED as a standalone option, LG has introduced the first 4K OLED TV.
And if that wasn't enough from LG, a bendable OLED screen is very much in the pipeline for 2015 - offering what the Korean giant describes as the "ultimate solution" for those who either haven't decided, or would like to be able to switch between a flat and a curved screen, depending on preference and content type.
We've already seen a 77in flexible OLED screen from LG in action at CES 2014. However, when it does become available, it will probably be beyond the reach of most budgets, at least to begin with.MORE: LG predicts bright future for OLED TVs as plasma faces final curtain
New OLED TVs for 2015
Apart from LG and Samsung, is there anyone else eyeing up OLED for 2015? It would appear so, yes.
Chinese manufacturer Haier announced a new TV range at IFA 2014 in Berlin - and that range included a 55in Full HD OLED set. We'll be keeping our eye out to see if it'll be coming to the UK, with pricing and release date to follow in due course.
There could also be a new challenger, too. TCL has unveiled a new technology called Quantum Dot (above) and is planning to release a Ultra HD 4K set with that tech on board. According to TCL, a Quantum Dot screen is claimed to be just one-third the cost of a comparable OLED set. Will it make much of an impression? No doubt time will tell.
Chinese manufacurer Hisense has introduced its own ULED (Ultra LED) technology, which it claims can produce a picture quality as good as OLED but for a fraction of the cost. The 65XT910 is subsequently the world's first ULED available to buy for £2200. We've yet to review any of Hisense's TVs, but we should be soon.
Best OLED TVs
Tested at £4000
The 65EF950V is the first flat 4K OLED TV we've tested and it has quickly shot to the top of our list of favourite 4K OLED screens. It may cost quite a bit, but you're well rewarded for the money. Due to its flat design it offers better viewing angles than its curved counterparts as well as a seriously impressive picture when viewing HDR content.
Tested at £3800 / Best price £3799
Want the ultimate TV available in 2015? This Award-winning LG might just be it. The first 4K OLED to grace our test rooms and it didn't disappoint.
It's expensive but in terms of performance it does everything we hoped for: deep black levels, punchy colours and impressive detail.
Tested at £2000
And LG has delivered the goods at the budget end, too. It's not 4K, a crucial difference, but if that's not an issue for you then you can enjoy OLED performance for under £2000.
If you want to see stunning pictures with your HD and even SD content, then this is a really compelling choice.
MORE: LG 55EC930V review
MORE: Best TV to buy 2015