Verdicts in the battle of Plasma vs. LCD vs. OLED.

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?

OLED

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
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.  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. 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
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. 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. 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
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. 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. 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.

Plasma

THE SCIENCE
Employs an enormous array of tiny cells of ionized gas (plasma), which activates each cell’s colored phosphor.

STRENGTHS
Plasma sales have been fading as of late against the LCD jauggernaut, but it’s not due to lack of image quality. Of course, this has to be qualified: When I talk about plasma HDTVs these days, I refer primarily to those coming from Pioneer — a company whose current sets are so far above the competition, they clearly define the state of the art.

That said, Pioneer continues to vastly reduce — and promises now to eliminate — the aforementioned “idle brightness” that keeps plasmas from delivering totally black blacks. The most talked about demo at this year’s CES, by far, was of Pioneer’s prototype ultra-black panel offered as proof-of-concept, followed by the company’s 9mm wafer-thin prototype. Pioneer says it will bring out TVs that combine both features, probably within a couple years. If they can, there may be life yet in this old dog, even in the face of OLEDs slow march to presumed dominance. Plasma displays continue to define picture quality standards, especially when it comes to darker images and shadow detail. The best examples can deliver a sense of color accuracy and consistent screen brightness from corner to corner that LCDs have a hard time matching. As Sound & Vision’s recent Plasma vs. LCD TV comparison test made clear, plasma still retains a distinct performance edge over LCD. Picture contrast, screen and grayscale uniformity, viewing angle — plasma TVs consistently rate better than LCD on all these key parameters. So for the foreseeable future, I will continue to nudge quality-conscious consumers seeking a new flat-panel set toward plasma.

WEAKNESSES
Heavy and power-hungry come to mind, though it remains to be seen if a super-thin plasma will still carry a big weight. And truth be told, image burn-in will always remain at least a mild concern with plasma TVs despite advances in this area. Manufacturing a display with cells small enough to deliver the 1920 x 1080 “Full HD” resolution demanded by many specification-driven customers can be costly. Power consumption has been improving with each generation, but still lags behind LCD displays. Plasmas tend to look less punchy than LCDs in a brightly lit environment. For a given size, plasma sets are usually deeper and heavier than an LCD.  While plasma offers a lot to satisfy demanding videophiles, those with more general viewing habits may find fault with the technology. Although the plasma “burn-in” issue has been seriously over-hyped by misguided sales folk, it’s true you can potentially damage a plasma TV if you use it mostly to play videogames or continuously watch channels like Bloomberg TV (that are crammed with static onscreen graphics) with the contrast and brightness settings cranked up.

DOMINATION POTENTIAL
Today’s best flat-panel images come from today’s best plasmas, and it remains an evolving technology from which the best is yet to come. Unfortunately, though, recent plasma advances may simply be too little, too late. I won’t fully discount it yet, but beyond the most demanding consumers willing to pay top prices, plasma is likely to cede the market to LCD.  Plasma continues to rule the roost in the 50-inch-and-up category, and remains the technology of choice for many videophiles. Early generation concerns regarding burn-in and panel life are now largely solved. When used in a controlled home theater environment, plasma delivers superior picture quality over competing flat-panel technologies. For the most part that’s something that won’t change dramatically. But unless plasma-makers manage to successfully reduce panel depth (Pioneer displayed a [3/4]-inch deep prototype model at the recent CES, indicating that progress is being made in that area), it may have a tough time going forward as new technologies like OLED shift into the big-screen TV marketplace.

LCD

THE SCIENCE
A matrix of thin-film transistors applies voltage to liquid crystal-filled cells sandwiched between two sheets of glass. When hit with an electrical charge, the crystals “untwist” to filter light coming from behind the cells. Each pixel comprises a red, green, and blue cell.

STRENGTHS
Image quality is advancing rapidly among LCD flat-panels lately, especially with the advent of LED-array backlights that can dim “locally” behind dark areas of the screen to achieve deeper blacks. Response time, color accuracy, picture uniformity (the ability to deliver consistent brightness and color across the screen), and horizontal viewing windows have (for the most part) also improved notably in the latest generation of sets. But the biggest thing LCD may have going for it is that manufacturers are banking on it as the future of mass market television, and have invested mountains of cash in new automated plants that will drive volume up and prices down. LCD boasts the widest range of screen sizes, from compact tabletop 13-inchers, to 65-inch-plus room fillers. 1080p resolution is common even in mid-sized models, though the benefits of 1080p with screens under 50 inches are debatable. Most LCDs have matte screen surfaces that are less susceptible to reflections in a brightly lit room, and power consumption is typically less than similarly sized plasmas. LCD picture quality has undoubtedly come a long way in the past year. When you combine that development with the reasonable prices LCD sets command, the technology’s broad appeal is understandable.

LCD is also the bright-room TV champ, edging out plasma by a nose when it comes to retaining picture contrast in well-illuminated spaces. And with new developments like LED-backlit LCD panels and ultra-fast refresh rates (180 Hz prototype models were shown at this year’s CES), picture performance just keeps getting better and better. Going forward, we’ll also see a shrinking of LCD cabinet depth: Hitachi just introduced a series of 1 1/2-inch deep models at CES, and it also displayed an even thinner 3/4-inch prototype with a 32-inch screen.

WEAKNESSES
Despite the new backlight technologies, LCD’s blackest blacks remain a notch below the best plasmas or any OLED, so it can’t quite equal those technologies in contrast and image depth. Narrow viewing angles on some models can also still be a problem in rooms with a broad swath of seating, though the best LCDs in this regard have very wide viewing windows. Many LCDs lose contrast when you’re seated off-axis. While prices are competitive in the 47-inch-and-under range, larger LCDs tend to cost more than equivalent plasmas. Some models are susceptible to motion blur and judder. LCD is currently riding the marketplace popularity wave, but its long-range prospects could be limited. That’s because, unlike self-emissive technologies like plasma and LCD that generate their own luminance, LCD display require a backlight. As Hitachi’s engineers demonstrated at CES, that backlight can be squeezed into a strikingly thin, 3/4-inch deep frame. But I can’t imagine LCD sets ever getting much thinner than that.

DOMINATION POTENTIAL
With plasma strong technically but fading in the market, and OLED still really a gleam in our collective eye, we can probably count on LCD to eventually take over as the volume leader for HDTV sales. LCDs sales dominance has been marching steadily up through the size ranges, and they now control most of the market below 50 inches. Their bright and punchy picture is a real asset on a brightly lit sales floor, even if that doesn’t always translate to a better picture in the typical home environment. We’ll be watching to see whether OLED can become a serious challenger. LCD delivers a one-two punch of solid picture performance and affordable price. For those reasons alone, LCD TVs are going to find their way into millions of homes over the next few years. But as other technologies — most notably OLED — manage to grow their screen sizes while retaining a wafer-thin form factor, LCD may ultimately get displaced — much in the same way current flat-panel TVs consigned bulky CRT models to the consumer electronics landfill.