|Guide: How to shop for your first HDTV|
|Articles - Featured Guides|
|Written by Olin Coles|
|Saturday, 21 April 2007|
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Television Technology Defined
Most of the visitors reading through this article are probably not inclined to know (or understand) the different television technologies that exist. For many, the decision to buy a particular HDTV comes down to display size and purchase price. This is unfortunate, since this concept applies to the new high definition televisions as well as it does to tires. While I wouldn't expect you to memorize the terms below, it's a very good idea to remember a few key terms so that you're preparred when the day comes to go shopping.
Like any good prosumer (professional consumer), I have done a lot of research within my industry. Over time I have been spoiled however, and often neglect those technologies which are considered economy or low-performance. As I explain the different television technologies, please keep in mind that they are listed from generally most affordable to very expensive. This should help you keep up with the sales market, since technology changes so fast.
Your old TV has some new competition, especially since analog broadcast is nearing its end. Innovative new Liquid Crystal Display flat panel televisions and similar Plasma technology are found in retail stores nationwide. Like many of the monitors we've reviewed here at Benchmark Reviews, LCD and Plasma TV's have the same slim profile and a flat viewing surface, but have been fine tuned specifically for video display.
CRT - Cathode Ray Tube
Cathode Ray Tube technology has been around forever, or at least since 1922 when it was made commerically available. Nearly every television set made during the 20th century was designed from CRT technology. It is most easily recognized by the solid glass screen, which went from fishbowl to flat-screen in its 80 years of market dominance.
CRT technology utilizes three cathode tubes, one for each color. As a team, these three colors combine or converge and paint the image onto the screen. Since CRTs are not designed to have a fixed number of pixels, they are very versatile products capable of producing clear images from high or low resolution sources. CRTs also require periodic 'calibration' by a trained professional, which can be expensive and adds to the total cost of ownership. CRT technology is not typically as bright as the others, but the refined picture quality of a properly calibrated CRT is among the very best.
LCD - Liquid Crystal Display
LCD technology is the current leader of the pack, having captured the majority of the market share of all new televisions and monitors sold. Most LCD televisions (and monitors) have five layers which make up the viewable panel. Each layer in the layer in the panel has its own specific role, which combined together produce a sharp image with very rich color.
But for those readers who want to know less about specific LCD technology, and more on how LCD TV's work, we offer this brief explaination: Of the many layers which comprise the LCD display panel, there are two sheets of polarized transparent material, one with a special polymer coating that holds liquid crystals, are adhered together. Electric current is passed through individual crystals, which interpret the information from the broadcast signal to allow or disallow light through them to create the specified image. The crystals themselves do not produce light, so the technology is non-emissive and therefore does not give off radiation like CRT technology does. Florouescent tubes called LCD lamps are housed behind the transparent material are used to illuminate the image, so they require less power to operate than CRT televisions and plasma displays. Recent advances in flat panel LCD technology now allow for larger screens, wider viewing angles, and higher-quality video images. Consequently, they are also several times lighter than comparably sized plasma screen televisions, and far more durable as well.
DLP - Digital Light Processing
Digital Light Processing is the product of the great minds at Texas Instruments. DLP uses a single Digital Mirror Device (DMD) chip that has thousands of tiny mirrors, each representing a single pixel. These mirrors tilt back and forth and deflect light as indicated by the source to create the image. One limitation of DLP technology thus far is brightness, which trails behind LCD technology. Although single-chip DLP is quite affordable, multi-chip DLP is much more expensive. Multi-chip DLP is much brigher than single-chip, but the cost difference may make it an unreasonable purchase for many consumers.
Plasma Display Panel
Plasma display technology is much thinner than older direct view display devices such as CRT televisions, making it easy to mount to a wall without interrupting the flow of a room. From a technical perspective, a plasma screen is basically a direct view of thousands of pixels (made of glass bubbles) filled with Xenon gas in a plasma state. Inside each bubble are three cavities, one blue, one red and one green. Each bubble is hooked up to an electrical current. That current is then triggered by information from your input device. Since you are looking directly at the source of the image (the bubbles) you get a vivid and rich color.
LCoS - Liquid Crystal on Silicon
LCoS is considered a combination of LCD and DLP technologies. LCoS is liquid crystal on a silicone wafer, with a very high pixel density. The number of pixels are less restricted than LCD or DLP because the electronics can be placed under the pixel rather than next to it. The high pixel density also means higher resolution, and a high pixel density also means no 'pixelization.'
OLED - Organic Light Emitting Diode
What is OLED (organic light emitting diode) technology? The implications of the new technology are remarkable, although the impact will not be felt for a few years. Unlike a CRT monitor, plasma display, or LCD monitor, the OLED uses emissive technology. This means that the screen itself emits light, and therefore doesn't require additional hardware for creating light, like tubes or lamps. Less hardware means less bulk. In fact, the screen could be as thin as a piece of paper, as shown here. Today you can find some OLED technology in cell phones, PDAs, and car stereos. In a few years, you may find OLED technology on laptop computers, car instrument panels, and perhaps even a portable presentation device that can be easily rolled up and stowed away.