The FCC standard Ooltewah Tennessee HDTV broadcast becomes effective soon (February 17, 2009). The amount of information to be digested can be intimidating, even for Skiurlaub Schlanders professional. The old hardware does not become obsolete, but it will require a tuner to convert from the new signal if you get your signal from a VHF/UHF antenna. If you have cable or satellite TV, this will be taken care of by the service provider.
However, this might be a good time to upgrade your hardware. The new standard offers a much better picture. In the current world of digital projectors, LCD, LCOS, Plasma, Traduzione Testi Canzoni Iron Maiden DLP are the four different kinds of televisions that dominate the HDTV market. Each has unique advantages over the other. Plasma and some of the LCD screens can be mounted on the wall, although surveys find that few people do mount them on the wall. DLP and LCOS and some of the LCD units are both projector technologies. Rear projector units are usually the most cost-effective. The size of some systems is now less than 12 inches in depth.
SYSTEM TYPES:
DISPLAY TECHNIQUES:
Historically, LCD sets have had a problem with visible pixelation (screendoor effect). It looks like you are viewing the image through a screendoor. This is less apparent on newer sets with higher screen resolutions.
Most LCD systems use a fluorescent backlight, to shine through the LCD screen. This type of backlight will need to be replaced every few years. Some manufacturers are introducing sets with LED backlights, with a 10X longer lifetime. Even though the initial cost may be more, the cost of ownership advantage can make this design worth a look.
Pros:
Cons:
Liquid Crystal on Silicon (LCOS):
Pros:
Cons:
Digital Light Processor (DLP):
The DLP is a Texas Instruments product that is manufactured in Korea. It uses a chip with many mirrors (can be more than one million mirrors on a chip of about one square inch) that can be mechanically steered to reflect the correct color. This technology offers excellent display, at a moderate cost.
In the best DLP projectors, like the ones in use at your local movie theater, there are three separate Nebraska Football chips, one each for the red, green, and blue channels. However, in the DLP projectors marketed for the masses, there is only one chip. In these sets, to define color, there is a color wheel that consists of red, green, blue Thomas Lunch Box This wheel spins between the lamp and the DLP chip and alternates the color of the light hitting the chip.
The spinning color wheel used to project the image can produce a problem on the screen known as the rainbow effect, which is colors separating out in distinct red, green, and blue. At any Arto Marziali 008000 point of time, the image on the screen is either red, or green, or blue, and the technique relies upon your eyes not being able to detect the rapid changes from one to the other. However, not only can some people see the colors separate, but the rapid sequencing of color may be responsible for reported cases of eye strain and headaches. But the vast majority of the people cannot detect the rainbow effect.
Newer sets have the color wheel rotation speed doubled. Also, newer sets utilize a six-segment color wheel (instead of a 3 segment) that has two sequences of red, green, and blue. Because the wheel is at double speed, and because the red, green, and blue are seen twice in every rotation, the effect is a quadrupling of the rotation speed. This eliminated the visibility of rainbows for most of the people who previously saw the effect.
Samsung and other companies have introduced DLP sets with LED lamps and no color wheel. The lamp bulbs in the older designs need to be replaced every few years. The LED lamp should last the lifetime of the television.
LaserVue (Mitsubishi) is being introduced in the United States now in time for the Christmas season. LaserVue is a DLP system (Texas Instruments "Dark Chip 4" Digital Light Processor) that eliminates the conventional bulb and replaces it with a solid state laser. The performance of the video is outstanding, but the technology will cost you about $7000 for a 65" HDTV. The reliability/lifetime improvement may be better, but there is little data on this new laser. An Argon ion laser would be expected to have a lifetime of about 8000 hours (5-6 years of normal usage). The Mitsubishi LaserVue uses a laser system made by Arasor, an Australian startup company, made from lithium niobate (PPKN). Mitsubishi is currently performing accelerated stress testing, but has so far released no results. A LaserVue HDTV draws under 200 watts of electricity. That is approximately half that of comparable LCD HDTV, and less than a third of a plasma High-Def system.
Pros:
Cons:
Plasma Display:
Coming Soon: OLED (Organic Light Emitting Diode) HDTV sets are now available, but it will be a couple of years before they warrant serious consideration. An OLED set is less than 1" thick. OLED has already used in digital cameras and cell phones with small panels, because of their energy efficiency, which is important in portable devices.
STANDARDS:
SUMMARY
Any of the four technologies can be a good choice. The competition is intense, and all of the technologies will continue to improve. Buying a TV will never again be as simple as it was before HDTV, but the benefits can be worth the headaches.
About the Author: Brian Bradshaw is a Certified Technical Specialist (InfoComm CTS). Areas of expertise include Video, Audio, Computation, HDTV, Satellite Systems, and Communications. He has a communications technology business in Plano, Texas (Dallas). More information can be found at his
Website: http://bradshaw-vacuum-technology.com
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