Last month, I was invited to visit LG Display’s manufacturing and R&D; facilities in Paju, Korea; something I had been hoping to do for several years. The trip was motivated by the many display exhibits I’ve seen at LGD’s CES suite every year – a suite we often refer to as “the candy store” because so many cool display concepts are in the spotlight.

At Paju, our small group was able to take a quick look at the mostly-automated LCD assembly process in one of the large fabs (P7) and tour an extensive Innovation exhibit, showing off the company’s latest developments in both LCD and OLED tech. Nearby, an enormous P10 fab was under construction; one which will be used to manufacture hundreds of thousands of OLED display panels each month.

While there are several different companies engaged in OLED research and development and others that manufacture smaller quantities of smaller OLED screen sizes, LG Display has decided to put all of its chips on this technology for televisions. The underlying science originally came from Eastman Kodak’s work on white OLED emitters in the 1970s and 1980s, and LG Display acquired the rights to that intellectual property several years ago.

Given the plethora of LCD manufacturing fabs in Asia and the plummeting costs of LCD TVs (largely due to China’s increasing dominance in the market), the LCD manufacturing and TV business is fast becoming a zero-sum game. It’s why legacy brands including Toshiba, Hitachi, Mitsubishi, and Panasonic have exited the consumer television market – the profit just isn’t there.

So a big investment in OLEDs is quite a gamble, especially since televisions using this technology sell for higher prices than comparably-sized LCD sets. Right now, a 55-inch Ultra HDTV using OLED technology retails between $2,000 and $3,000, depending on whether there is a sale or special promotion.

65-inch sets are even more expensive: A quick check on the Best Buy / Magnolia Web site shows a variety of OLED TV models (including one from Sony that uses LG Display panels) ranging in price from $3,000 to $5,500. There’s also an LG 77-inch model for $15,000, if you want to go that big.

Some perspective is useful here. Way, WAY back in the mid-1990s, a 50-inch 720p/768p plasma TV would set you back between $25,000 and $30,000. Before plasma manufacturing stopped just 15 years later, you could pick up a 50-inch 1080p model with “smart” functions for as little as $500. So it’s reasonable to assume the downward price curve will come into play once again as demand ramps up.

OLED display technology is a very different beast than LCD and has more in common with CRTs and plasma, since it uses an array of emissive color pixels (plus white pixels for higher brightness). Emissive architectures don’t have the issues that hamstring LCDs, such as contrast flattening and color de-saturation when images are viewed off-axis. As we saw in an eye-opening demo using a star field on a deep black background, edge-illuminated HDR LCD TVs can create an unwanted “shaft of light” artifact while trying to modulate black levels across a small a local area and still maintain high brightness and contrast. OLEDs have no such difficulty with this type of content – the high-contrast star field images reproduced as you’d see them in real life, displayed as intense point sources of light on a near-black field.

The OLED “stack” is also much thinner than an LCD – in the case of the new LG “wallpaper” OLED displays, it’s just 4 mm. Since it’s also possible to form OLED pixels on plastic surfaces, we can create a different class of flexible displays. I’ve mentioned this more than once on previous occasions: The largest market in the world for displays is transportation. Think of anything that moves and transports people and goods – ships, trains, planes, cars, trucks, subways. G-forces and sustained vibrations are the two biggest threats to displays in these applications. By making the substrates thin and flexible, we can minimize the long-term effects of both threats.

The behavior of OLEDs as they slowly come out of black (quiescent state) to full white is very predictable – these are low-voltage devices, after all – and it’s possible to show images with very low luminance values that are not limited by the inherent characteristics of LCDs. Even the best plasma displays that used fractional, low-luminance pulse-width modulation techniques can’t equal the performance of an OLED.

There’s always a ‘catch,’ though. OLEDs (like any other emissive display) have a practical brightness limit. For a full white screen, that’s in the range of 100 to 200 cd/m2, while a 10% window can hit about 600 cd/m2. Contrast that with an LCD TV equipped with quantum dots, which can achieve a peak small-area brightness measurement in excess of 1000 cd/m2.

But everything is relative. While you may need more horsepower if you are viewing images in a brightly-lit room; in a darkened room or in the evening, 500 cd/m2 peak brightness is more than adequate. And the ability of OLED displays to render shadow detail down to near-black (close to .0005 cd/m2) means they can show images with high-dynamic range – over 20 stops of light can be displayed from just above black to 100% white.

The other ‘catch’ has intrigued us display analysts for years, and that is differential aging of different OLED colors. While green and red appear to have acceptable half-life spans, dark blue has always been a challenge. Sony’s original 25-inch and 17-inch TriMaster RGB OLED monitors acknowledged as much by raising the power consumption over time to maintain a 100 cd/m2 brightness target as the blue emitters decayed. Samsung’s first 55-inch curved OLED TV – shown about 4 years ago – used dual blue emitters that were twice the size of the red and green emitters, another way to tackle differential aging.

LG Display’s technology uses a white OLED emitter that combines two doped compounds. One by itself emits blue light, while the other emits yellow light. Together, they create white light, and RGB color filters round out the package. The combination works very well, although LG Display adds a white pixel for every red, green, and blue combination to boost brightness. (Presumably this trick sacrifices a bit of color saturation and certainly makes for plenty of animated discussions among home theater enthusiasts!)

While speaking with Dr. Jang Jin Yoo, who heads up LG Display’s Image Quality Development Department, I asked if there was any measureable decay in the blue doped compound over time. If so, this would result in images with a yellowish tint. His reply was that the white OLED emitters should last 20,000 hours before any such decay might be observed, at which point the entire OLED array might have reached 50% of initial brightness. (And it’s likely that you would have replaced the TV long before then anyway.)

My other question had to do with something I observed at the 2016 CE Week TV Shoot-Out conducted by Bob Zohn of Value Electronics. I didn’t make this year’s event as I was in Korea, but at last year’s running I had observed a greenish tint on a 55-inch LG OLED TV when viewed off-axis at just 30 degrees. The folks at LG Display in Paju had not heard of this previously, so I loaded up a few photos on my phone to show them what I saw. (This phenomenon was confirmed by Joe Kane and a few other golden eyes.)

The answer? There wasn’t any forthcoming during our visit, but I’m hopeful I may get one eventually. It may have been a production issue with 2016 models, and I don’t know if the same thing was seen this year at the Shoot-Out. My theory was that something in the TV’s optical path was acting like a bandpass filter, attenuating red and blue light output off-axis while boosting green response.

If you are a display aficionado, you know that the best images consistently come from emissive displays – bright, saturated colors, wide viewing angles in both axes, low black levels, and excellent contrast. Over time, we’ve weaved back and forth from motion picture film (transmissive) to CRT televisions (emissive) to rear-projection television (transmissive) to plasma TVs (emissive) to LCD TVs (transmissive).

With wider adoption of OLED technology, we are swerving back into the emissive lane again. And if you need any convincing that emissive is here to stay, look at the wave of fine-pitch, super-bright inorganic LED displays now available for commercial displays: They’ve already put a dent in sales and rentals of high-brightness front projectors and are becoming the preferred backdrop display for TV news broadcasts.

We’re a long ways off from micro LED TVs in our living rooms. For now, the next best thing is OLED technology. In addition to LG’s lineup, Sony is now selling two models with LGD panels – will others jump on board? Panasonic had a nice 65-inch offering using the LGD panels, but took it off the market. Will it come back as a companion to Panasonic’s UHD Blu-ray players?

From what I could tell, LG Display believes the future of displays is OLED technology – that’s where the bulk of their capital investments are going. They expect to finish their massive P10 OLED fab line sometime late this year or early next year, at which point they will be able to roll larger sheets of motherglass and yield more cuts. That should bring 55-inch and 65-inch UHDTV set prices down to a level that consumers expect.

Those are my observations from Korea for now. Look for more thoughts on OLEDs in future columns…

EDITOR’S NOTE: This article has been updated to correct the thickness of a 65-inch OLED panel (4mm, not 2.5mm) and peak brightness in a 10% window (600 nits, not 500 nits).

*LG Display also contacted me after publication to state that the expected time to half-brightness for white OLEDs is officially 50,000 hours, not the 20,000 hours quoted in this article. As a veteran of many years in the display industry, I have seen half-brightness specifications like 10,000, 20,000, and 50,000 hours used far too liberally in the past to believe most of them. I would have to see more specific aging studies that could substantiate a half-brightness claim of 50,000 hours, and as I wrote in my article, it’s unlikely anyone would keep a television long enough to rack up even 20,000 hours on it in any case.

If you watched television for 6 hours a day, 365 days a year, that would amount to 2,190 hours, and at that rate, you’d hit the 20,000-hour mark in just over 9 years. It’s highly likely you would have replaced your television by then.