TV makers expanding low-brightness LED backlit models into entry-level market


When LCD TVs were first competing against plasma TVs, one key differentiating argument was their brightness. Typical TVs have brightness measuring around >400 nits (1 nit is roughly 1 candela per m2), which is deemed suitable for TVs typically viewed in a living room and at a distance. Plasma TVs' full-white brightness is typically sub-200 nits; <300 nits is more typical of computer/laptop screens.

However, the trend in LCD TVs is now swinging toward lower brightness, according to DisplaySearch senior analyst Jimmy Kim. Most existing low-brightness TV models were small and targeted the secondary market, but earlier this year first trials began for low-brightness TV models, with low-cost direct LED backlighting, in the main segment of large TVs, he notes. The tradeoff is sacrificing design and picture quality for cost ??? lower brightness for the LED component, and a thinner light guide plate. These efforts have reduced the cost gap between LED and CCFL backlights to <1.3??, so pricing is similar. (A spike in CCFL materials prices is another reason for the shrinking cost difference.)

Consumers have responded enthusiastically, and low-brightness LED-backlit TVs accounted for more than 10% of total LCD TV shipments in 2Q12. So TV makers are now planning more models with low brightness, even those using edge LED backlights. Most mainstream TV models are now being designed with ~350 nits, and some entry-level models will be as low as 250 nits, to fend off the charge of low-cost backlight TVs (300-350 nits). Soon the only 400-nit LCD TVs will be high-end models, Kim predicts.

Getting edge-lit backlight TV brightness down to 250 nits narrows the cost gap between them and CCFL models from 2?? to 1.5??, which is still a bit higher than aforementioned gap between CCFL and direct LED backlighting. But the goal here, Kim notes, isn't to offer another CCFL alternative ??? it's targeting the same entry segment as low-cost low-brightness direct LED backlight TVs. ??? J.M.

Solid State Technology | Volume 55 | Issue 9 | November 2012