Apple's new MacBook showcases LED potential
Apple s high-profile launch of ultra-thin MacBook computers yesterday could herald a key year of transition for LED backlights in liquid-crystal display screens.
The latest "MacBook Air" notebook, revealed by Apple CEO Steve Jobs at the Macworld exhibition in San Francisco, has delighted technophiles - largely because of its incredibly thin display, which measures just 0.16 inches at its thinnest point.
Incorporating high-brightness LEDs into the LCD backlight is crucial for producing such a sleek, lightweight design, and the iconic electronics company could set a trend for much greater LED backlight production in 2008, for both notebook computers and TVs.
Luminus Devices, the US company that specializes in high-end LEDs for the display and TV backlight market, believes that the trend towards thinner LCD designs is a key one in its favor, and something that could prompt faster adoption of LED backlights.
"LED backlighting for LCD TVs has so far been very limited," Luminus told compoundsemiconductor.net. "Manufacturers with a direct LED backlight design [are] using hundreds or thousands of LEDs for large-screen LCDs."
According to Luminus, one 40-inch TV launched in 2007 needed a phenomenal 2100 LED chips to illuminate its screen with sufficient intensity. "The result is a much higher bill-of-materials and large retail price premiums, limiting their market acceptance," the company added.
Luminus believes that its own solution - microstructured chips that are implemented in an edge-lit backlight unit - results in far fewer LEDs being required, and also enables very thin designs.
The Massachusetts-based company is yet to ramp its "PhlatLight" (short for photonic lattice) LED units for LCD TV backlights, although it is planning to move into volume production in the second half of 2008.
So far, Luminus has been successful in the rear-projection TV (RPTV) market, where sales of the PhlatLight are growing, despite an overall decline in the RPTV business.
Last year, it ramped production to support the needs of Korean giant Samsung, among others, and at the recent Consumer Electronics Show (CES) in Las Vegas, Luminus showcased the PhlatLight's suitability for pocket projectors and LCD TVs.
Although Luminus products for all these applications are based on the same photonic lattice microstructured LEDs, there are some crucial differences in the technical requirements.
For example, in RPTVs, where the PhlatLight is used in conjunction with a digital light processor (DLP), separate packages are used for the red, green and blue chips. But in LCD backlight units, all three colors are combined within a single package.
Another key difference is in the electrical requirements of the different applications. In RPTVs, a single RGB chipset is driven at a high current to illuminate the screen via the DLP system. The DLP element also requires a pulsed sequence of light from the LED chips.
While pocket projectors, which use smaller DLPs, are similar to RPTVs, LCD backlights demand that the LEDs illuminate light guides continuously. This means that they typically run at a lower current than for RPTV applications, but that the overall power consumption in LCD systems is much higher.
The key advantage that Luminus can offer LCD TV designers with its PhlatLight product is that far fewer LED chips are needed. The company says that instead of hundreds or thousands of emitters, just eight of its RGB chipsets would be required for a "large screen" LCD, which should translate to a much lower bill of materials for TV makers.
The price tag attached to LED backlights is not so much of a problem for Apple, because the new MacBook Air only has a 13.3-inch screen.
But with the obvious advantages of solid-state lighting technology now being pushed by a marketing operation as sophisticated and influential as Apple s, the MacBook Air should help to tip the balance in favor of LED backlights across all display applications.
• Luminus Devices founder Alexei Erchak is one of the speakers taking part in the forthcoming Key Conference, which is returning to Key West, Florida, on 2-4 March 2008. Click here for registration and further details about the event.