The quality of the picture on desktop monitors, laptop screens, LCD (liquid crystal display) TVs and dozens of consumer-electronic devices is set to improve drastically with backlighting technology that creates far more vibrant colours, brighter screens and sharper images.

Backlighting helps create contrast on LCD screens by illuminating the background so that the foreground appears sharper.

The technology, LED (light emitting diode), is new to the marketplace for a few reasons, mainly cost. A user would have to pay two or three times as much for an LCD TV that uses an LED backlight instead of a traditional CCFL (cold cathode fluorescent lamp) backlight, for example.

But prices have come down to the point where most technologies start to break into the market, when specialists or enthusiasts are willing to pay. And once LED production rises, reaching heavier volumes, prices will come down - and continue to drop as rivals in the industry expand factories and grab for market share.

It's the 'trickle down' theory of the technology industry, that new technologies start at the high end, where users are willing to pay a premium for better performance, then as production volumes expand, prices fall and the technology moves into the mainstream.

"It all depends on supply and demand and when people want the quality," said Nithi Nithipalan, chief executive officer of Tekcore, an LED maker in Taiwan.

In some devices, particularly smaller ones, LED backlights are already becoming common. Sony's PSP (PlayStation Portable) handheld-gaming device, is one prime example, since gamers demand the best image quality possible. And more gadgets using LED backlights are on the way.

"The next major product will be the notebooks, notebook screens... maybe in the first half of next year," said CT Liu, vice president of AU Optronics' technology center, forecasting when LED backlights will become standard in laptops.

LED backlights are making headway in laptops because costs are coming down and LEDs use less power, saving battery life. In laptops, power saving is far more important than plug-in devices, and screens tend to be a major battery drainer. LED backlights reduce power usage by at least 10 percent compared to older technologies, Liu said.

The trickle of LED backlights into PC monitors and laptop screens has already started in premium models. Sony, for example, uses LED backlights in some high-end Vaio PC monitors and premium laptops, such as its Type T and Type F series.

But for LCD TVs, heavy costs are holding the technology back. The more LEDs required for the backlight, the higher the cost, since LEDs are aligned, one-by-one, on an array. LEDs are, in essence, tiny light bulbs illuminated by the movement of electrons in semiconductor material, and they fit easily onto electrical circuits. They're being used more and more in traffic lights and other products for lighting (not as backlights) because they don't have a filament, like ordinary incandescent bulbs. As a consequence they last a lot longer.

There have been some attempts to market LCD TVs that use LED backlights. Sony used to offer the Qualia 005 LCD TV, complete with an LED backlight, but users weren't willing to pay the premium price.

"We still plan to use the technology in the future," said Mina Naito, a Sony representative in Tokyo. The company even used one in an 82in LCD TV prototype it showed off at the CES (Consumer Electronics Show) in Las Vegas early this year, she said.

AU Optronics has been providing 23in LCD screens with LED backlights to customers, mainly for sale to users in design work and modelling. Larger sizes, up to 42in, can be found but they're expensive.

Still, the cost of LEDs continues to fall, and that should encourage companies to use them in more products, to the benefit of users.

In 10in screens and smaller, LED backlights now have a cost advantage over CCFL backlights, says Nithipalan, and he predicts the technology will continue to make inroads into larger screen markets. His company is already placing its bets, with a new $200m (about £112m) factory aimed at catching rising demand.