Beyond the boob tube

Anyone heeding the siren song of today's televisions would do well to carry a technical dictionary when shopping. In the absence of such a thing, this brief glossary of TV-set terms may be helpful.

CRT: Cathode ray tube. CRT television sets have been the standard for more than 50 years. It's this "tube" that provides a slang term for the TV -- and it's the thing that sticks out in back and causes sets to be so deep.

Digital monitor: A TV that can display digital programming images but does not come with a built-in tuner or set-top box. Sometimes its marketed as an "HDTV-ready" set.

EDTV: Enhanced-definition television. A term used to describe a 480p picture. Traditional TV has 480 lines of picture, but enhanced 480-line sets refresh progressively (that's the "p"), making for a sharper, brighter picture. That's good, but its not HDTV (see below).

Flat-panel TV: A super-thin set that you can hang on the wall like a picture or slip onto a book shelf or the kitchen counter.

Flat-screen TV: This may be one of the super-thin sets or it may simply be a cathode-ray set with a screen made of flat, non-glare glass, not the traditional curved glass. If you can't quite tell from the picture in the ad, you'll know soon enough from the price.

HDTV: High-definition television. HDTV provides a digital picture made up of 720 or 1,080 image lines, as opposed to traditional TV's 480 lines. The resulting image is 10 times as sharp as a traditional TV's. Most current HDTV sets are not integrated; if you read descriptions carefully, you'll see that they are HDTV-ready or HDTV-compatible, meaning you'll still have to buy a tuner someday.

Integrated set: This refers to an HDTV set with a built-in tuner, used for receiving over-the-air signals.

LCD: Liquid crystal display. LCD monitors feature a layer of liquid crystals sandwiched between two polarized glass plates and backlighted by fluorescent bulbs. In general, LCD technology is used for screens up to 20 inches.

LCOS: Liquid crystal on silicon. LCOS technology sandwiches a liquid crystal layer between a cover glass and a mirrorlike surface patterned with pixels that sits atop a silicon chip. Permits shallower projection TVs -- the new Cineos from Philips, with its 55-inch screen, is 17.4 inches deep.

Pixel: A word coined from "picture" and "element." A pixel is the smallest piece of a television image. HDTV images have about 2 million pixels, about six times as many as in ordinary TV images.

Plasma screen: Plasma screens feature thousands (even millions) of little glass chambers filled with a neon-xenon mix between wired glass panels. These screens will be found in TV sets larger than 20 inches.

Progressive scanning: A system of video display where lines of a picture are consecutively displayed, as opposed to "interlaced."