Makers seek perfect flat-panel screens

28 Aug, 2007

A new crop of acronyms is about to hit the flat-panel screen business as manufacturers seek ways to convince shoppers that television A contains snazzier technology than television B.
The screens, a key product at IFA, the huge consumer-electronics fair opening Saturday in the German capital Berlin, are getting better all the time at depicting fast motion without leaving brief ghostly trails.
That means frequent model changes and this confuses even sales-people. The fanciful names of all these picture-improving software refinements often leave customers clueless as to what has been changed.
Both LCD and plasma screens have more pixels - the dots making up the picture - than traditional cathode-ray-tube televisions, which means regular TV transmissions have to be reprocessed into a larger number of pixels.
The software makes the contours of the resulting picture less zig-zaggy. A key new technology in making motion smoother is the 100-hertz refresh rate, which throws up 100 pictures a second, double the rate of 50-hertz PAL television transmissions used in many countries of the world.
Inserting an extra, in-between image faster than the eye can see takes away flicker effects and gives the impression of a steadier, sharper picture. Liquid crystal displays (LCDs) far outsell plasma panels in Europe these days thanks to their lower price. Plasma screens were once the only economic choice for shoppers wanting large-sized displays, with LCD televisions much smaller. Back in 2001, there was amazement when Sharp produced the first 32-inch LCD.
These days, Sharp is producing panels with a diagonal measurement of 108 inches (2.74 metres) at its factory in Kameyama, Japan, and cutting up those panels to make four or more regular-sized televisions.
The biggest plasma display offered by top maker Panasonic measures 103 inches on the diagonal, and even Panasonic accepts that the market favours LCDs. The company is to begin selling a 37-inch LCD in its Viera range from next month in Japan. Samsung of South Korea, which makes both types of flat panel, affirms that it will stick to the two-pronged approach. A European executive at Samsung, Michael Kurpiers, said, "We are not going to abandon the plasmas.
LCDs have largely got rid of their motion trails, their formerly dull colours and their artefacts, those brief rectangular splotches that indicate that the processor has lost a portion of the picture. Most screens sold in Europe carry a "HD ready" label indicating that the panel can handle an incoming high-definition signal, though it will not actually display this in high definition.
Achieving the latter earns the higher-priced products a designation as "Full HD", meaning they have images made up of 1,080 horizontal lines, rather than the 720 lines of "HD ready." An industry magazine, C'T, says a Full HD logo, certifying that a display can show every single line of the original image, is likely to be unveiled by Brussels-based European industry group EICTA at IFA.
The next step towards the perfect picture is coping with a speed inconsistency between the 50-hertz and 100-hertz displays on the one hand and the new Blu-ray and HD DVD movie players now entering the market.
On the disc, the images are stored at the 24 frames per second used in movie shooting, but the high-definition players convert the footage to 60 images per second, usually by the expedient of showing all the even images twice and the odd images thrice. The human eye mostly does not notice the trick, but when the camera shifts very slowly, a certain jerkiness is perceptible.
Some higher-priced TV sets, marked with the description "24p," can display the movies at the true frame rate, but most flat-panels make do with a less sophisticated conversion, though either way, the viewer ends up seeing the action at normal life-like speed.
"The displays are not very good at processing these high- definition signals," confirms Lothar Kerestedjian, research and development chief at a German production studio, Enteractive Entertainment. Top manufacturers said at briefings that they will demonstrate improved software to IFA to help overcome the problem.
One of the long-awaited technologies that will not be seen at IFA is the surface conduction electron emitter display (SED) which was shown by Toshiba and Canon at the 2006 Consumer Electronics Show in Las Vegas as an alternative to LCD and plasma screens.
SED has been described as basically a tiny cathode-ray tube for every single pixel of the display and Canon claims it consumes less power than LCD displays. However Toshiba has left the joint-venture development team and no commercial product has emerged. It may be that SED televisions will never see the light of day.
-dpa

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