The MacBook Air has become the best advertisement for why companies should use LED (light-emitting diode) backlights in notebook screens, and is driving adoption, according to market researcher DisplaySearch.

LED backlights in display screens are an improvement over old CCFL (cold-cathode florescent lamps) technology for several reasons, including a stunning picture due to more vibrant contrasts, better power savings, and they're easier on the environment because they contain no mercury and last longer.

They also helped make the MacBook Air a marvel of thinness because they take up less space inside a screen. LED backlights are about half as thick as CCFL backlights, according to Luke Yao, an analyst at DisplaySearch.

"The problem with LED backlights is still cost, but prices are coming down," he said during a conference in Taipei.

The price of an LED backlight is still twice as much as that of CCFL or more. And the screen of a laptop is often its most expensive component, or second only to the microprocessor.

LED costs are falling as makers increase production. The technology is gaining ground in more and more devices, including mobile phones and auto lights, after getting their start in toys, MP3 players and other small displays. As production increases, the cost per unit comes down.

Notebook PCs, desktop monitors and LCD-TVs (liquid crystal display televisions) are the next ground for LEDs to conquer, and DisplaySearch believes the technology will perform well this year. The number of laptops, monitors and LCD-TVs with LED backlights will quadruple to 16.7 million units in 2008 from 4.0 million units last year, the market researcher said.

In laptops alone, LED backlights will increase to 7.2 percent of the entire market in 2008 on screens smaller than 14-inches, from 3.4 percent last year, DisplaySearch said. The MacBook Air carries a 13.3-inch screen.

On laptops with screens 14-inches or larger, LED backlight use will rise to 4.6 percent of the market this year, from just 0.1 percent last year. Next year will be a breakout year for LEDs in this category, as LED backlights go into 19.9 percent of all notebook PCs shipped, a figure that will nearly double to 38.8 percent in 2010.

The MacBook Air didn't start the trend to using LED backlights, but its stunningly thin design will prompt other companies to put out similar notebooks, Yao said, further spurring the LED industry.