Which one gives you a home theater - an LCD or a Plasma HDTV Flat Screen TV
2008-08-05

Television technology is rapidly expanding and there is a new winner every few years. Until recently the plasma TV, then was switched to LCD. So which one is better? Which one is the mainstream in the future? This is a much debated topic.

What are the LCD and Plasma? 

Plasma technology consists hundreds of thousands of individual pixel cells. The pixel allows electric pulses (stemming from electrodes) to excite rare natural gases-usually xenon and neon-causing them to glow and produce light. This light illuminates the proper balance of red, green, or blue phosphors contained in each cell to display the proper color sequence from the light. If you come very closely at a plasma TV, you can see the individual pixel cell coloration of red, green, and blue bars. You can also see the black ribs which separate each. The Liquid Crystal Display (LCD) displays come from the same technological background. A matrix of thin-film transistors (TFTs) supplies voltage to liquid-crystal-filled cells sandwiched between two sheets of glass. When hit with an electrical charge, the crystals untwist to an exact degree to filter white light generated by a lamp behind the screen. LCD TVs reproduce colors through a process of subtraction: They block out particular color wavelengths from the spectrum of white light until they're left with just the right color.

What are the differences?

PICTURE CONSIDERATIONS CONTRAST / BLACK LEVELS Plasma technology has certainly achieved quite high contrast ratios, a measure of the blackest black compared to the whitest white. Panasonic has long been the leader in plasma black levels and we measure contrast of a 42" HD Panasonic plasma at about ANSI 1450:1 - impressive. Plasma displays achieve such impressive black levels by using internal algorithms to block the power to particular pixels. When it is producing full white, a plasma TV uses the most power. LCD (liquid crystal diode) displays, by contrast, utilize electric charges to twist and untwist liquid crystals, which causes them to block light and, hence, emit blacks. As opposed to plasma, LCD TVs use the most power when displaying a very dark or black image. This is a difficult process, only the best LCD televisions (like those produced by Sharp and Sony) have managed to topple the 1000:1 contrast ratio. The one continual drawback here for LCD is off axis viewing, when black levels consistently drops. ADVANTAGE: Plasma. 

COLOR ACCURACY In plasma displays, each pixel contains red, green, and blue elements, which work in conjunction to create 16.77 million colors. It exhibits more richness in color information and more natural coloration. Today, SMPTE color coordinates in top plasma displays still normally outperform those in LCDs. LCD TVs reproduce colors by manipulating light waves and subtracting colors from white light. This is an inherently difficult template for maintaining color accuracy and vibrancy. While color information benefits from the higher-than-average number of pixels per square inch found in LCD televisions (especially when compared to plasmas), LCDs are simply not as impressive as plasmas with similar pixel counts. ADVANTAGE: Preference to plasma but depends upon room light, manufacturer and model. VIEWING ANGLES Plasma manufacturers have made much of their viewing angles, which is about as good as horizontal and vertical viewing angles get. The superiority of plasma viewing angles is demonstrated when viewing dark material content, especially DVDs. A Plasma display holds the black levels from off axis, while LCD TVs lose black level intensity more as the angle off axis increases. LCD TV manufacturers have done much to improve their displays' viewing angles. The substrate material on newer-generation LCD models by Sharp and Sony has helped to expand those units' viewing angles, though they still have some ground to cover before catching plasma.

ADVANTAGE: Plasma LONGEVITY In actual fact, an LCD TV will last as long as its backlight does - and those bulbs can sometimes be replaced! Since this is nothing more than light passing through a prismatic substrate, there is essentially nothing to wear out in an LCD monitor. However, one nasty little known fact about LCD technology is that as the backlight ages it can change colors slightly (think of florescent office lighting). Plasma, on the other hand, utilizes slight electric currents to excite a combination of noble gases (i.e., argon, neon, xenon), which glow red, blue, and/or green. This is an essentially active phenomenon, so the phosphoric elements in plasma displays fade over time. At half life, the phosphors in a plasma screen will glow half as brightly as they did when the set was new. There is no way to replace these gases; the display simply continues to grow dimmer with use. ADVANTAGE: Even, depending upon manufacturer quality. SCREEN BURN IN LCD technology is not prone to screen "burn-in" or "ghosting" (premature aging of pixel cells) due to the nature of the technologies "twisting crystals." With plasma, static images will begin to "burn-in," or permanently etch the color being displayed into the glass display element. The time it takes for this to occur depends greatly on the anti burn-in technology of the manufacturer. ADVANTAGE: LCD, though not as much a concern as it was 2 years ago. PRODUCTION SIZE AND COST All television measurements are stated in inches and are for diagonal measurement of the screen from corner to corner. Both plasma and LCD TVs are becoming more readily available in larger sizes though plasma still leads the size battle by a great margin. Though such mammoth monitors are expensive, they exhibit none of the "kinks" one might expect with such large displays. The substrate material for LCD TVs has proved difficult to produce in large sizes without pixel defects owing to faulty transistors. ADVANTAGE: Plasma POWER CONSUMPTION Because LCDs use florescent backlighting to produce images, they require substantially less power to operate than plasmas do. LCD TVs consume about half the power that plasma displays consume. The reason: Plasmas use a lot of electricity to light each and every pixel you see on a screen - even the dark ones. ADVANTAGE: LCD PRICE AND RESOLUTION LCD HDTV displays will have a higher resolution per same size comparison than plasma. 42 inch HD plasma has a resolution of 1024 X 768. Those extra pixels and the production process of LCD HDTVs cost more money to produce. Expect to pay a third as much more for a similar size LCD TV than a plasma display. ADVANTAGE: It's currently hard to judge. What is the future direction?

Consulting considers said that the development of HDTV flat screen TV will take on "one big and one small" directions. "Big" means that flat panel TV will enter into big screen era, and plasma TV has unique advantage in big screen market, there will be a surging demand of 40-inch above big screen flat panel TV, which will then impel the sales of plasma TV. "Small" means that if the resultant market effect is that LCD will capture the vast majority of the 40 in. to 60 in TV business. It will be the price leader with a quality image that will satisfy nearly all consumers who prefer an ordinary size. The substantial contrast ratio advantage of LCD over plasma when viewed in a bright [sunlight or lamps] room will continue to provide another key decision factor.