While plasma has ruled the roost in widescreen technology, LCD prices have come down, refresh rates are getting higher and viewing angles are getting wider. Jeanne-Vida Douglas discovers why 2006 is being widely predicted as the year LCD unit sales overtake their plasma counterparts.
It all started with the cathode ray tube (CRT). For more than 75 years these big, heavy boxes graced lounges and desktops. Traditionally as long as they are wide, they work by firing negatively-charged particles through a glass tube at a film of phosphor atoms. When the electrons hit the phosphor it lights up, and the image appears on the outside of the glass screen.
About 35 years later Liquid Crystal Display (LCD) and plasma screens were invented within weeks of each other. However, by that stage CRT technology was so affordable and so widely produced that it would be another four decades before either of these technologies presented a serious challenge.
Plasma screens are made up of a tiny mesh of little boxes or tubes of gas, generally xenon or neon. On either side of these tubes is a grid of electrodes which send a slight current into each box based on the signal received by the monitor.
Like fluorescent lights, the gas contained in these tiny tubes lights up when electrically charged, because the ions and electrons rush back and forth and smash into each other releasing photons. As with CRT technology these photons react with a film of phosphor producing the image we see on the outside of the screen. LCD screens on the other hand consist of a thin film of long thin crystals sandwiched between two sheets of glass.
The outer layer of the glass is polarised so that it only lets through certain wavelengths of light, and fine lines of indium-tin oxide are traced either horizontally or vertically across the screen. These lines create a grid which is controlled by the monitor's circuitary which delivers a slight voltage to a specific point on the screen. This voltage causes the liquid crystals to tint, or block, light coming through the screen.
Following their invention the technologies went in entirely different directions.
While plasma screens etched out a niche in high-end display technology and gradually worked their way down into the home theatre market, LCD screens grew up as calculators and watches, before turning into computer monitors in the late 90s. Thanks to a boom in personal technology such as phones and digital cameras, and the complexity associated with manufacturing LCD technology, the turn of the century saw a shortage in supply, which constrained the market for a few years.
This break allowed plasma technicians to get the jump and iron out some of the problems associated with the technology.
While big is beautiful the early generations of plasma screens consumed large amounts of electricity, and produced a slight hum when activated (not unlike florescent lights). Often used for moving commercial display, this technology never lent itself to computer monitors because when heated for a long period of time the phosphorus burns stationary images onto the screen, leaving a permanent ghost of taskbars or start buttons.
Most of these problems have been overcome in the latest version of plasma technology, while massive expansion in LCD manufacturing plants has brought these screens back with a vengeance. According to retail research company GfK, plasma screens have outsold their LCD counterparts over the past twelve months, by more than 30,000 units. The growth rates, however tell a different story. Over the past 12 months, plasma screen sales have grown by 150 per cent to 156,000 units while over the same period LCD screens grew at about 210 per cent to 122,000 units. Research carried out by GfK tracking the attachment rates overall shows that in the last 12 months, the most common application for flat screen technology is high-definition TV. About 60 per cent of screens were sold in conjunction with some kind of set-top box to receive the digital television signal. Just seven per cent of these screens were sold in conjunction with a Media Center PC, and only six per cent in conjunction with a games console.
Despite these figures, which appear to indicate that television and movie viewing are the main drivers of flat screen purchases, IDC commercial market research director, Landry Fevre, expects LCD sales to outsell plasma screens in the mid- and long term.
"Although we expect LCD screens to outsell plasma screens, both markets are expected to experience significant growth over the next couple of years," he said. "It's all about volume. Plasma screens lead sales at the moment because they are still cheaper than LCD screens. But we are already seeing a shift in favour of the LCD technology, and as LCD sales increase in unit terms, production will ramp up and we will see prices coming down, further driving sales."
Such figures would indicate that LCD technology is rapidly gaining acceptance in the TV and film viewing space, traditionally dominated by plasma monitors.
PICKING A HORSE
Taking such predictions into account, a few vendors including Viewsonic have opted to focus their energy entirely on the LCD market. Most vendors, however, are still opting to carry both products, and some even feel the imminent predominance of LCD technology is exaggerated.
Mitsubishi Electric general manager for digital electronics, Richard Freggi, said plasma would dominate the battle for lounge room walls for sometime to come.
"On paper, LCD technology looks like it has made great leaps and bounds but the market will still respond to the superior image quality you get from a plasma screen," Freggi said. "While LCD technology is always snapping at the heals of plasma sets in terms of price and size, developments in plasma technology means it is improving commensurably and will continue to provide a better picture with a wider viewing angle at the high-end of the market. More critically plasma technology is cheaper in larger screens, and until prices for LCD screens come down, plasma will continue to dominate the market."
In order to sell either, resellers need to know what these issues have been, and how vendors have gone about improving their technology. While the burn-on associated with plasma is well known, there are a number of reasons this technology has been the wide display of choice for home theatre, and commercial applications. Having recently announced a new LCD and plasma range, Sanyo is keen to promote both technologies, albeit into slightly different markets.
"Plasma is a very good technology, and it's still more affordable in the larger screen sizes," Sanyo Oceania home entertainment business manager, Des McDaid, said.
"Traditionally the plasma screens were much better at showing you a moving image because of refresh rates. LCD screens were really no good for watching sport or movies because moving images would leave a ghost across the screen. But the technology is improving for both types of screens."
Virtually unnoticeable on a computer monitor, LCD ghosting would leave spectral streaks behind rapidly moving images. Plasma maintained crisper images and a higher contrast ratio, which provides for sharper images and blacker blacks.
Viewing angles were also a challenge with early LCD monitors, as the display allowed either for the appearance of slightly tinted light, or a very small amount of light. Less light resulted in a duller picture with a reduced viewing angle, due to a slight lag in the twisting and untwisting of the liquid crystals which form the LCD display.
Plasma screens on the other hand, have traditionally produced a brighter, crisper moving image, which can be seen from a much wider viewing angle. And while they are less expensive than their LCD counterparts they consume more electricity, tend to have a shorter lifespan, are much heavier, less portable, and more challenging to install.
While these challenges remain in the public mind, vendor research labs have been working hard to overcome many of the issues associated with each technology. Like Sanyo, LG has a foot in both LCD and plasma camps. AV and telecommunications category manager, Darren Goble, said in the next 12 months LCD screens would take a larger share of the sub 34-inch market - while plasma screens continue to lead in the larger screens. He pointed to a number of measures vendors such as LG are taking to prevent ghosting in both types of screens.
"Plasma is still the leading seller, and while the best defence against burn-in is educating the consumer at point of sale we now have a number of technical approaches to overcome this problem as well," Goble said.
New plasma screens are now equipped with a function that cuts the brightness of the image by half if it hasn't moved for more than 10 minutes. This reduces the likelihood the image will be burnt into the phosphor lining the screen.
Another approach is to move a stationary image by a few pixels at a time so that it prevents burn-in but is barely noticeable to the viewer. Slightly more radicle, the third approach is to include a white wash function, which essentially resets the phosphor by streaming white light through the burnt-in screen.
"All these approaches help to mitigate the problems associated with burn-in, but if you're likely to use the screen for lot of computing work, games, or even digital television an LCD screen might still be your best option," Goble said. "All these applications have parts of the screen which remain stationary over periods long enough to change the phosphor."
On the LCD ghosting front, all vendors are working hard to improve the refresh rate, and expand viewing angles. Having dropped back in the market over the last 12 months, Sony said its new Bravia would help reclaim a leading position in the market.
"Traditionally, plasma technology provided a wider viewing angle because the colour LCD image was created by using just 25 per cent of each pixel. By creating different size holes, the Bravias have improved the contrast ratio, and increased the viewing angle to 178 degrees," Sony Australia group marketing manager for home network products, Ian Lowe, said.
So while vendors continue to argue about price and position, resellers are best advised to learn as much as possible about the challenges associated with both technologies, and the improvements being made in each area. Stock both, and know enough about each technology to discuss the customer concerns and requirements.