So what is the difference between LCD & plasma and which technology is best for you. In this article we give you the full monty on both technologies.
There are two main competing technologies for TV screens: LCD and plasma. While there are still a number of factors to consider when selecting a TV, what used to be the three primary ones–size, price and resolution–are no longer an issue.
When they first hit the market, LCD screens were limited to about 45 inches, measured diagonally, while plasma screens could reach 60 inches or more. Both have increased substantially in size since then, and today LCD TVs can be as big as plasmas.
Sharp demonstrated a 108-inch LCD at the Consumer Electronics Show in 2007. Both Samsung and Panasonic have displayed 103-inch plasma versions. Of course, these are a bit large for typical consumers, but affordable 40- to 60-inch LCD and plasma screens are readily available. In terms of price, comparable TVs using either technology cost around the same. Finally, the screens display 720p resolution, and many offer 1080p, in high definition.
According to a presentation by the Consumer Electronics Association at CES, LCD TV sales grew 160 percent in 2006 over the year before, representing the fastest consumer product growth. In comparison, plasma TV sales grew by 58 percent, the eighth-highest growth rate. The association also said prices of TVs with 50-inch-plus screens have dropped 32 percent over the past year, making them the fifth-fastest decreasing-price category.
Picking one technology over the other requires some understanding of how each works. LCD TVs work by charging a pixel on the screen to change the amount of light that passes through a red, green or blue color filter. There are two planes of transparent material with one side containing a liquid crystal display polymer coating. Nematic liquid crystals, naturally twisted in form, are added between the two planes. When an electrical current is applied, the crystal untwists, preventing light from passing through. When a certain color is desired, a different electrical current allows light to pass through the color filter in varying degrees. Each of three pixels–for red, green and blue–permit degrees of light to pass to create the desired color. The screen image is created by all the pixels operating at the same time.
Plasma TVs have myriad tiny phosphor-covered bubbles. An electrical current passes through each and, depending on the current, they radiate the desired color. There are two planes sandwiching plasma, a gas made of ions and electrons. When an electrical current is applied, the ions and electrons hit one another, generating ultraviolet light. This light, normally invisible to the human eye, interacts with a layer of phosphor, creating visible light. Phosphors are colored red, green or blue.
Getting down to brass tacks
Here, I compare the technical specifications of two plasma and two LCD TVs with 42-inch screens. The sets are different brands and regularly priced within $300 of one another.
All are within a narrow range in terms of size, although the Toshiba model is about 25 pounds heavier than the lightest TV,
The only real differences are in the display format, contrast ratio and brightness. While high-definition DVD players such as BluRay and HD DVD send 1080p signals, most HD signals from cable providers and satellite are either 720p or 1080i. Typical viewers will not notice a big difference in resolution, except when it comes to screens 60 inches or larger. The 1080p displays are commonly found in LCD TVs, while 720p is typical for plasma TVs (though some plasmas do offer 1080p).
Contrast ratio and brightness are more dependent on the manufacturer than the technology. Samsung’s set has a very high contrast ratio and phenomenal brightness. But the plasma TV from Panasonic does not have superior brightness or contrast levels compared with the LCD TVs. Interestingly, neither factor seems to tie into power consumption. The LG TV has lower active power consumption than the Panasonic plasma TV, but consumes more in standby.
As for product lifetime, LCD and plasma both are rated at 60,000 hours. In other words, six hours of use a day equates to 27 years of viewing.
When plasma was introduced, there was some concern about burn-in, but this has largely been eliminated. Where burn-in does occur, manufacturers say watching something that does not have the stationary image will make the burn-in disappear.
With LCDs, there have been complaints about ghosting, which occurs when action is so fast that the image cannot change colors quickly enough. New solutions can counter this, primarily software to increase the refresh rate from the commonly used 60 Hz to 120 Hz in some newer sets. But since cable and satellite programming transmit at 60 Hz, increasing the refresh rate is not the whole answer. Some manufacturers add black frames between the color frames so each time a color frame occurs it is freshly generated. Others do a contrast where each frame is divided into two color aspects–the first uses only red and blue, while the second uses only red and green.
Today, there are not many differences between LCD and plasma TVs. Both work well and will do what you want them to do. And chances are that both will be out of style shortly after you get it, making you drool over the next release. I purchased a Sony 60-inch LCD set, and three months later I was ready to hear about the 1080p model. It never ends.