February 01, 2006
| by EH Staff
Here’s our quick look at the terms and technology in today’s televisions.
- Stands for: Liquid crystal display.
- What the &#!!?: It’s what you have in your flat-panel computer display.
- Available in: Flat-panel TVs, rear-projection sets, some front projectors.
- How it works: Crystals in a liquid are activated by an electrical current.
- What’s so good about it: Provides a bright, high-contrast image.
- What’s not so good: Viewing lower-resolution images can sometimes be like looking through a screen door.
- Stands for: Digital light processing.
- What the &#!!?: It’s a technology by Texas Instruments.
- Available in: Most lightweight video projectors and some rear-projection sets.
- How it works: Light reflects off a tiny chip containing millions of tilting mirrors.
- What’s so good about it: Produces bright images with high contrast; projectors are lightweight and portable; rear-projection sets are thin.
- What’s not so good: Some people can see artifacts or harshness around the edges of images.
- Stands for: Um… plasma?
- What the &#!!?: Think flat.
- Available in: Flat-panel displays.
- How it works: Electrical impulses excite cells of plasma gas.
- What’s so good about it: Your TV can hang on the wall.
- What’s not so good: They run hot, and some have loud fans. Images left on the screen for a long time can “burn in” to plasmas displays with older technology.
- Stands for: Liquid crystal on silicon,
- What the &#!!?: Used in Sony’s SXRD, JVC’s HD-ILA and others.
- Available in: Front projectors, rear-projection sets.
- How it works: Light reflects off a chip encrusted with liquid crystals.
- What’s so good about it: Produces a smooth, high-contrast image.
- What’s not so good: Early sets did not meet the technology’s promise.
- Stands for: Cathode ray tube
- What the &#!!?: They’re the big, bulky TVs we all grew up with.
- Available in: Traditional direct-view sets, some rear-projection sets, a few front projectors.
- How it works: A huge tube focuses a beam of electrons on a phosphorescent screen.
- What’s so good about it: Produces smooth, filmlike images; pictures on direct-view sets and images on rear-projection sets can be seen in well-lit areas.
- What’s not so good: They’re big and heavy. Front projectors need low lighting, or the picture will wash out. Front and rear projectors require periodic lens alignments.
- Stands for: Surface-conduction electron-emitter display.
- What the &#!!?: It’s a technology to watch for.
- Available in: Flat-panels to come.
- How it works: There are three tiny CRT-like emitters for every pixel.
- What’s so good about it: The great image of a CRT in a flat-panel display.
- What’s not so good: It’s not here yet, and it’s going to be expensive.
The ABCs of HDTV
- High-definition television is a form of digital TV. Other forms of digital TV are enhanced-definition TV (EDTV), and standard-definition TV (SDTV). All these sets can receive digital TV channels, which will become the standard in the next few years. But only HDTVs can receive high-definition programming.
- HDTV has a resolution of at least 720p. Other resolutions include 1080i and 1080p (the letters stand for “interlaced,” and “progressive,” which are ways the image is shown on the screen). Most sets will convert a higher or lower resolution to their formats.
- Resolutions expressed in numbers like 1280 x 768 refer to the number of pixels across by the number of pixels top to bottom on a screen. The second number must be 720 or higher for the set to be an HD.
- EDTV has a resolution of 480 to 720. SDTV is below 480. Do yourself a favor: Spend more and buy the HDTV.
- All HDTV images are widescreen, or 16:9, meaning the shape of the screen is 16 units across to 9 units high. We don’t know why they have to make this so complicated.
- Many HDTVs are “integrated,” meaning the digital tuner required to receive a digital broadcast is built in. Some even have cable tuners built in, and some “digital-cable ready” sets accept digital CableCARDs that slide into a slot to act as a cable tuner. Sets without integrated tuners may be marketed as HDTV ready, HDTV compatible, or HDTV monitor. If you’re going to get HDTV off a separate cable or satellite box, you won’t need a built-in tuner.