Although LEDs are branching out into everything these days from laptop PCs to traffic signals, we'll bet you never knew why they're just not up to scratch for replacing domestic lighting.

The problem is, the white light needed to illuminate homes, businesses and shops can't be generated cleanly enough by current LEDs. The whitest existing LEDs are actually blue modules with a coating of phosphors that gives the illusion of whiteness.

Blacker reds

That's all very well where the quality of light isn't a big deal, but the weak red component this generates means red objects don't show up properly. In a supermarket using such lighting, for example, tomatoes would look black to the human eye, which is hardly ideal.

Into the darkness, however, comes Toshiba, which has come up with a new LED that can shed proper white light thanks to the addition of aluminium nitride to the mix.

Commercial plans

With the same phosphor coating as before, the new LEDs are more than a match for existing fluorescent lighting and exhibit none of the dark red problems.

If testing goes well, the LED takeover should begin in earnest soon, with commercialisation slated for 2010.