Both Sharp and AU Optronics said today that they had developed prototype displays that are less than a millimetre thick.

The Sharp LCD measures 2.2in diagonally and is just 0.68mm thick, making it the thinnest mobile phone screen in the world. Coming in just behind is the AUO screen, which is a 1.9in model that's just 0.69mm thick.

The screens used in most of today's phones are on-average between 1.5mm and 2.5mm thick so the new Sharp screen is significantly thinner, said Miyuki Nakayama, a spokeswoman for Sharp in Tokyo.

Sharp is coy about just how it managed to reduce the thickness but said innovations lay in two major areas: improvements in production technology that enable the use of thinner glass sheet and a reduction in the thickness of the backlight that sits behind the screen.

Thinner mobile phone screens are good news for consumers because they allow phone makers to either produce slimmer phones or to pack more technology into the same size space. Some recent models of mobile phone have been getting larger in-part because of the addition of new features such as digital TV tuners and smartcards.

However, there's no word from Sharp on when the screen might start appearing in mobile phones. The company is currently in talks with mobile phone makers and hasn't decided when it will start production, said Nakayama.

The svelte screens will get their unveiling at FPD Expo, which runs from Wednesday to Friday in Yokohama, Japan.

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