Let‚Äôs clear up a couple of misconceptions about HDTV (High Definition Television) as it applies to the rapidly emerging LCD technologies. The acronym LCD stands for Liquid Crystal Display. Occasionally, you will run across someone who defines it as Liquid Crystal Diode. This is incorrect. They are most certainly confusing LCD with LED. LED stands for Light Emitting Diode, and is perhaps best known as the red lights that we have seen on clock radios for years. (today, LED‚Äôs are able to produce many other cool colors.) A diode, by the way, is an electronic check valve, that stops current from going in an undesirable direction, and has nothing to do with the transmittance or projection of light for televisions. The other interesting thing about LCD technology that results in confusion is that there are three distinct types of LCD televisions! First, there is the Flat Panel LCD, which competes with Plasma televisions, secondly, Rear Projection LCD which competes mainly with DLP (Digital Light Projection) TV‚Äôs, and finally, front projection LCD, which projects onto a screen and can be as big as 200 inches in a home theater. (300 inches, if you have a really big room!) The lightest, thinnest televisions anywhere are the flat panel LCD TV‚Äôs. LCD rear projectors are much thicker than their LCD Flat Panel siblings. The LCD rear projection sets, which compete with the microdisplay DLP (Digital Light Processing) models, are in the 15 to 19 inch thick range and weight around 100 pounds. Front projecting LCD‚Äôs are small, lightweight and very portable. One model weighs four pounds, but you will need a place to project the image. Toshiba makes all three types of LCD televisions!
The terms ‚Äúliquid‚Äù and ‚Äúcrystal‚Äù in LCD refer to the medium that the current is applied. Tiny magnetic molecules twist and bend, depending on how much electrical current is sent through them. The twisting and bending is a matter of degree, and the change in shape allows for more or less light to pass, which allows for up to 1024 shades of gray in television displays. The common wall clock or digital watch is another example of LCD in our daily lives. Interestingly, mathematicians use the term LCD for Least or Lowest Common Denominator and the Atkins Diet people use LCD for Low Carbohydrate diet, but let us stick with LCD and the most important use ‚ÄìLiquid Crystal Display. The rear projection HDTV‚Äôs are usually DLP, LCD, or LCoS (Liquid Crystal on Silicon) and are slowly replacing the Cathode Ray Tube (CRT) models. They also stack up well against their plasma rivals. They do offer excellent picture quality and large sizes of screens, but don‚Äôt expect the deepest blacks, or the extremely wide viewing angle of Plasma. The sets are bulkier than plasmas as well, but are still less than 19 inches deep.
Posted by larry dixon at 14:52:00. Filed under: General