LED backlighting looks to the big screen

26 Jan 2006

iSuppli's Kimberly Allen puts the spotlight on LED backlighting at Photonics West's display market seminar.

LED backlighting in LCD televisions was the focus of Tuesday's display seminar at Photonics West. Kimberly Allen, the director of display technology and strategy at market research and consultancy firm iSuppli led the discussion.

"LEDs are certainly in the limelight right now with solid-state lighting challenging lamps [for backlighting]," Allen told the audience. "LEDs have penetrated the small LCD backlighting market and we are just beginning to see adoption in larger displays."

Cold cathode fluorescent lamps (CCFLs) remain industry standard in terms of LCD backlighting, but their days could be numbered as Allen revealed. "The color gamut is only about 72% of the NTSC standard," she explained. "They suffer from poor performance at low temperature and as the display gets larger and more lamps are required, the light gets less uniform." CCFLs also contain mercury.

In comparison, mercury-free LEDs have a wide color gamut, are temperature insensitive and offer fast switching. Problems exist in terms of efficiency and thermal management, but Allen feels that a few more years of development will address these issues. "Solid-state lighting is not a simple substitution in backlights and a systems integration approach is needed," added Allen. "The role of the LED maker has also not been determined [and] some may want to move up the value chain."

It has been said that OLEDs could also challenge the CCFL, but Allen has her doubts. "At the brightness required for a backlight, the lifetime of the OLED cannot be guaranteed beyond 5000 hours," she commented. "OLEDs may serve as a backlight for small LCDs, but at this time penetration into larger LCDs cannot be foreseen."

•  The market seminar series is a new addition to Photonics West and includes an optoelectronics industry forecast, a look at the nanotech roadmap for optics, and an assessment of market opportunities in nanophotonics.

Author
Jacqueline Hewett is technology editor on Optics.org and Opto & Laser Europe magazine.