Light-emitting diodes (LEDs) will largely supersede cold-cathode fluorescent (CCFL) backlighting in notebooks over the next four years, according to analysts iSuppli.

LEDs are thinner and use less power than cold-cathode units and they don't use environmentally damaging mercury. Currently they are a lot more expensive but they are likely to get cheaper.

iSupply predicts that by 2012 nine in 10 screens with diagonals of 10in or more will have LED backlights. This compares with just 4.7 percent late last year.

But it says there demand for CCFL products will not slacken because of their use in TV sets and other monitors.