Posted on Sun, Nov. 13, 2005
JONATHAN TAKIFF TECHNOLOGY A clearer picture of plasma TVs
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The gizmo
Old rumors die hard, and there are lots of 'em floating around about plasma televisions. Let's clear up some of the misconceptions about these sleek, flat-panel, hang-on-the-wall screens.
All flat-panel TVs are 'plasmas'
Just like all facial tissue is Kleenex, right? Wrong.
Plasma is a type of thin, flat-panel display illuminated by hundreds of thousands of individual pockets of charged gas. A rival form of flat-panel TV makes pictures from tiny LCD (liquid crystal display) shutters that open and close to let through light from a fluorescent source.
Plasmas burn out fast
That was true a decade ago. But the gas in today's plasma screens is more durable. First-quality screens from the likes of Panasonic, Pioneer, LG and Hitachi are rated for 60,000 hours of use - that's about six hours a day, every day, for 28 years - before fading starts to become obvious.
Burn-ins are a problem
Ghostlike after-images can remain when an image (such as a frozen video game scene) is paused for a long period on a plasma or a conventional picture tube set. Here, too, plasma makers have significantly tamed what used to be a serious problem with better materials and preventive/corrective circuitry.
Recently, I left a video still image paused on a Pioneer plasma screen for three hours (oops), yet there was no ghosting when I returned.
If burn-in does occur after a much longer "pause," running the set for another 24 hours clears up the problem.
Pictures look better on LCD
That depends on where you're watching. In a sunny room, brighter LCD screens do "pop" better, conceded demonstrators from Panasonic, which sells both varieties of flat panels.
But in a dimly lit room, a plasma makes a better impression. Most noticeably, the blacks are blacker because the plasma picture elements (pixels) blink fully off, while there's always a light source glowing behind the LCDs.
Also, plasma pixels refresh faster (to eliminate blurring) and don't fade when viewed off-axis - long-standing (but now lessening) concerns with LCDs.
Plasmas burn more electricity
While true in the past, the latest models are lower in power consumption than comparably sized LCD screens.
All plasmas are alike, right?
Wrong. While only five manufacturers make plasma panels, they save the latest/greatest versions for their own brands.
Also, the customized back end of a set is a major factor in determining image quality.
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