How long do plasma displays really last?

“Plasma lifespan” misinformation confuses and frustrates many people who want to invest in an excellent, big flat-panel home theater display for TV, movies and games. Will that big, bright, life-like plasma image, go dark in a couple of years? Many times the misinformation given about plasma is motivated by the self interest of some big-box store salespeople and their management.

For fun, stroll into a big-box TV reseller and ask a salesperson, “How long does a plasma display last?” They’ll say: “Plasma lasts only about 3 or 4 years, but if you buy our 5-year warranty, we’ll replace it with a new one if it fails.” These salespeople want to sell warranties. You’ll hear them say virtually anything to put an extended warranty on your sales slip.

Meanwhile, lots of newspaper “tech-talk” columnists perpetuate the “3-year plasma lifespan” myth. Why? To stay on good terms with the LCD-TV maker, which "temporarily" loaned them a 30-inch flat TV and so far, hasn't asked them to return it.
 

Plasmavision display phosphors remain bright, slowly losing some brightness over a long, long time. After 60,000 hours of TV (27 years of typical family TV use!) 2005 Plasmavision displays will be about half as bright.

The technical term for this phosphor-brightness trend is “Life to Half Brightness” or LTHB. It is different than the term “lifespan” or “half-life.” Say – right now, out loud – “Life to Half Brightness” a few times. It’ll roll off your tongue more easily when you speak with big box store salespeople. Better yet, mention LTHB to a seasoned A/V pro, so they will recall what the excellent LTHB track record of past phosphor based displays - TV's, computer monitors, and 3-gun front- and rear-screen projectors. A Fujitsu Plasmavision display blows other phosphor based technology out of the water when it comes to brightness longevity. LTHB of a typical TV is 10,000 to 20,000 hours; a calibrated TV studio’s control room monitor may have an LTHB of 60,000 to 70,000 hours or more. And for a Fujitsu Plasmavision display? That same 60,000 hours.

Graphing LTHB shows that the phosphors never actually dim completely.  Instead, they gently slow their dimming so it’s not noticeable.

Lifespan of LCD Displays
LCD flat monitors are backlit with fluorescent lamps which contain phosphor – also with a predictable LTHB. Yet LCD backlights are always at full brightness, no matter what’s on screen.  If you reduce LCD’s brightness, the lamps still remain bright.  (The LCD pixels darken or lighten in response to screen images.) There’s no guarantee that all the backlights will age identically – so some will darken more rapidly than others and leave the image looking like light and dark stripes.  These lights are replaceable – in theory.  In practice, it’s anyone’s guess whether or not replacement lamps will be around in 7 to 10 years!