What is LED TV?
There are some important differences between LED back lit TVs and LCD TVs.There has been much confusion about the recent unveiling of so-called "LED TVs." To clarify, an LED TV is simply an LCD TV that uses LED back lighting as opposed to the traditional fluorescent back lighting.
In some senses this new naming convention is a marketing decision on the part of LCD TV manufacturers, as these new TVs can be considered "LED TVs" only as much as the previous generation of LCD TVs could be referred to as "Fluorescent TVs." But there are some important differences in how an LED-back lit TV will perform compared to a fluorescent TV that may affect consumers' decisions.
Letís take a look at some of those factors to understand when deciding whether or not to purchase an LED TV.
What is an LCD TV, exactly?
LCD TV stands for liquid crystal display television. LCD is one of the two competing high-resolution flat-screen television technologies (plasma TV is the other). LCD TVs work by supplying voltage to liquid-crystal filled cells sandwiched between two sheets of glass. When hit with the electrical charge the crystals will untwist to a certain degree to allow white light produced by a lamp behind the screen to filter through. The intensity and range of the back light that is filtered will then produce the desired range of colors.
Though many reviewers prefer the image quality of Plasma technology, LCD TV has become the dominant flat screen technology in todayís market. An electronics retailer should present a variety of TVs to provide the consumer with a feel for the current options and price points on the market are today.
So whatís the advantage of using an LED back light?
LED stands for "Light Emitting Diode," and represents a new and developing wave in lighting technology. As it relates to LCD TV technology, the primary differences between LED and fluorescent lighting lie in the fact that fluorescent back lights must always remain on, and lack the range of color that LED can offer.
In practical terms, this means that fluorescent back lights can never produce true and deep blacks, as some small amount of light will always leak through the cells. This can create a perception that fluorescent-lit LCD systems lack a certain amount of sharpness. LED TVs are (in some cases) designed to eliminate this problem, by providing a locally dimmed back panel of individual LED lights.
IĎve heard about edge-lit and back lit LED TVs. Is there a difference?
Yes. There are two different LED technologies on the market. The first is edge-lit LED. These function by placing an array of LED lights around the perimeter of the display. This allows for an ultra-thin set, but functions in much the same way as a traditional fluorescent. Unless the setís thinness is an important consideration, it may be difficult for a buyer to justify paying a higher price for this technology.
The second form of LED technology is back lit LED. These function by creating a grid of true LED back lights, which can be controlled locally to create deep blacks and color contrasts. When scenes require total blackness the LEDs in that area can be completely shut off, so no amount of light penetrates through the cells.
Do back lit LED sets truly work? And are they worth my money?
TV viewers, as well as many afficionados of electronics, will tend to agree that back lit LED sets do offer a sharper image. The degree of difference, however, will vary. One important difference between LED sets is that some use only white LED lights, while others use a spectrum of color lights. Typically, the difference between white-LED sets and fluorescent sets is minimal, but sets using colored LED lights will offer a marked advantage in displaying realistic colors and contrasts. Notably, few industry experts believe that even the improved LED LCD sets create a better image than high-end plasma sets.
Currently, LED LCD sets are significantly more expensive than both their fluorescent cousins and competing plasma models. If the difference in image quality is important to the buyer, and if a plasma TV isnít a suitable option (screen burn, for example, is a common problem with plasma) an LED set may be worth the plunge.
One other consideration: Itís possible increasing demand and brand competition will move LED TV technology from its current position as a Ďpremiumí line to the industry norm. Interested buyers may benefit by delaying their purchase several months and watching prices drop as LED becomes the standard.
CNet: LCD vs Plasma
Video: LCD vs Plasma