Display-Tech Smackdown

SED seems DOA. And as for Mitsubishi's new laser TV . . . hasn't the world pretty much moved beyond rear projection?

This means three HDTV display technologies seem primed to race for all the marbles: plasma, LCD, and OLED.

At this year's CES, both plasma and LCD have bragging rights to some new-and-improved's, while OLED is just new and improved in general. So what are their strengths, weaknesses, and likelihood to be the reigning HDTV-display technology? S&V executive editor Rob Sabin, technical editor Al Griffin, and contributing technical editor Michael Trei look into their liquid crystal balls.


Sony's new OLED set, the XEL-1

THE SCIENCE With OLED (organic light emitting diode), a stack of organic polymers, including both emissive and conductive layers, is deposited on a substrate containing a thin-film transistor (TFT) array. An electrical charge passing between the bottom electrodes and an additional transparent layer on the surface of the display stimulates the emissive organic layer, which in turn creates light.

STRENGTHS Sabin: If you've not seen a prototype OLED TV or Sony's new compact model, it's hard to fully understand the impact of the picture. I'll sum it up in one word: contrast - or rather Contrast, with a capital 'C.'

Like plasma, OLED is a self-emitting display technology that requires no backlight or projection lamp. But unlike most plasmas we've seen to date, an OLED doesn't need to keep its pixel cells partially fired up at all times to be ready to respond to the signal. That's because OLED cells respond so quickly, they can be fully turned off until needed. Signal response time in an OLED is measured in microseconds (a far cry from the several millisecond response times in today's LCDs). Bottom line: Blacks on an OLED should be pretty much as black as black can be, which makes for a bright and dynamic picture with depth that has to be seen to be believed. Add to this a wafer-thin form factor that will have your interior designer drooling, and you can make a good case that OLED is the future of HDTV.

Trei: At its core, the manufacturing process is simpler than LCD or plasma, which could eventually make OLED the most economical display type. OLEDs also promise dramatically reduced power consumption, and much faster screen response times than either LCD or plasma.

Griffin: With a depth of only a few millimeters, OLED is by far the thinnest display technology available - its ultra-slim form factor makes it akin to an architectural element like glass or mirror. Also, variations on the technology, such as transparent OLED, hold the promise of cool, futuristic stuff like video displays that transform into a window-like surfaces when switched off. Other OLED benefits include punchy contrast and color, wide viewing angle (a characteristic it shares with plasma technology), and low power consumption.

WEAKNESSES Sabin: Sheesh - how about ridiculously expensive and prohibitively small, for starters. I've not seen an OLED prototype from any manufacturer beyond 31 inches diagonal, and the only commercially available product right now - Sony's XEL-1 - measures a mere 11 inches and costs $2,499! I suppose you have to start somewhere, but I wouldn't anticipate big, affordable OLEDs anytime soon.

Trei: While the XEL-1's $2,500 price tag will limit its appeal for now and manufacturing OLEDs involves several patented technologies, which might require costly license fees. Still, large-scale production could eventually lead to OLED displays actually costing less to build than their LCD and plasma counterparts.

Griffin: Whereas plasma and LCD are both mature technologies snagging sizeable chunks of the current TV market, OLED technology has barely busted out of the lab. OLED displays can be found in digital cameras, GPS units, and portable media players, but the only consumer OLED display you can buy today is an 11-inch monitor from Sony that costs $2,500 - about the same as an average 52-inch LCD or plasma TV! Two reasons why OLED manufacturing lags behind the other flat-panel options are low yield (only a small number of panels actually make it past the quality-control stage) and differential aging (the blue pixels in an OLED display tend to lose brightness at a faster rate than red and green ones, which means OLED TVs have a limited lifespan compared to LCD and plasma - technologies spec'd to last two decades or more).

DOMINATION POTENTIAL Sabin: Great promise, and probably the eventual winner in the HDTV technology sweeps, once sizes grow and prices drop. But recent advances in plasma and that technology's cost-size advantages in today's world (see below) could give OLED a serious contender for the long term, at least in picture quality. And LCD has heavy market forces behind it.

Trei: Despite its modest size, Sony's 11-inch XEL-1 could be the start of something really big. OLEDs redefine how thin a display can be, and their low power consumption will be a clear plus point in an increasingly green conscious world. A critical assessment of OLED's performance potential will have to wait until we get one into our testing facility.

Griffin: Until OLED's technical issues get ironed out, it will continue to be aimed at the portable electronics, as opposed to home theater, market. But once its hurdles are overcome (and you can be sure TV makers are working feverishly on it), OLED's wafer-thin form factor and crisp, punchy picture quality will likely let it trounce competing flat-panel technologies. Plasma and LCD are hereby put on notice.