Your Future Television Set

Three years from now, television transmission in the United States and many other developed countries will switch from analog to digital. This will create a massive overhaul at the retail level as consumers scramble to upgrade to sets able to take advantage of the new service. In this month's feature "Goodbye, CRT", author Paul O'Donovan looks at the technologies competing to win your dollars in the race to replace the aging warhorse that is the cathode ray tube TV.

O'Donovan is a principal research analyst for Gartner Dataquest, in Egham, U.K., who covers semiconductors and consumer electronics. He begins by looking at the two early frontrunners in the race: plasma and liquid-crystal-display (LCD) televisions. Plasma TVs are what consumers want these days, but they are expensive, making LCD sets the more popular of the two now. O'Donovan notes that a 42-inch-diagonal plasma set with a tuner sells for about US $2000 today, while a 37-inch LCD set goes for about $1200. This year, nearly 8 million plasma TVs will be manufactured worldwide, contrasted to 42 million LCD units.

Each technology, though, has its shortcomings in the long run to TV technology dominance, O'Donovan explains. Because of their gas-based imaging technology, plasma sets have limited longevity, they're power hungry, and they're heavy, for starters. Plus, they suffer from issues such as burn-in and, of all things, problems at high altitude. LCD displays, unfortunately, use a technology that intrinsically produces images with a relatively poor contrast ratio, the difference between the brightest white and the darkest black on screen. Moreover, their fluorescent tubes age over time. After about five years of normal home use, the tubes start to dim and their colors begin to drift.

This is the point where a third horse enters the race. O'Donovan points to the emergence of the surface-conduction electron-emitter display (SED) over the next few years. He writes:

In an SED, every single pixel of the display is, effectively, a cathode-ray tube. The cathode is a thin film of palladium oxide, chosen because it is electrically conductive and also extremely durable, resisting oxidation and corrosion even at high temperatures. As in a CRT, electrons emitted from the cathode hit phosphors—tiny dots of metals or rare-earth compounds that glow red, green, or blue when energized.... The result is a flat-panel display that uses less energy than a plasma screen does and yet has image quality close to that of the CRT, still the benchmark of all displays. Power consumption is low, relative to that of plasma, for the same reason as it is for the CRT: it takes a lot less energy to create an electron beam than it does to excite photons in a gas.

Manufacturers such as Toshiba and Canon have begun trial production of SED TVs in the 40- to 50-inch range. When the first units ship in about a year, they are expected to cost about 50 percent more at retail than comparable plasma sets. O'Donovan says that it is too early to tell if SEDs will suffer from problems similar to the long-term reliability or performance issues of plasmas and LCDs.

So which TV technology will take the prize in the aftermath of the 2009 switchover? O'Donovan foresees two types of winners in two different categories. At the smaller end, for sets with displays less than 50 inches, LCDs and SEDs should dominate, with plasma technology gradually dying off, killed by economics rather than technical faults. At the bigger end, for sets larger than 50 inches, the ultimate champ, in his analysis, will be a dark horse, a new generation of projection TVs. Yes, that's right, a technology from the past that it is even now being digitally re-engineered to provide the big screen experience of your dream home entertainment system of the future. To find out how this dramatic turnaround is shifting the television landscape, you'll have to read his article.


Tech Talk

IEEE Spectrum’s general technology blog, featuring news, analysis, and opinions about engineering, consumer electronics, and technology and society, from the editorial staff and freelance contributors.

Newsletter Sign Up

Sign up for the Tech Alert newsletter and receive ground-breaking technology and science news from IEEE Spectrum every Thursday.