Tiny projector could feature in cellphones

Posted by Emma Woollacott

A projector small enough to be incorporated in a cellphone should be on the market next year.

The device, from Ecole Polytechnique Federale de Lausanne (EPFL) spin-off Lemoptix, has a projection head just one centimeter cubed and a total size smaller than a credit card.

It can be integrated in a laptop, cellphone, or even an MP3 reader, say its creators. It needs 30 percent less current than matrix- or LED-based projectors.

The size of the image can be adjusted by modifying the distance between the beamer and the projection surface, with the resulting image remaining clear, says Lemoptix. It works at a minimum distance of 50 centimeters, and enables the projection of images onto a surface equivalent to a 15-inch screen.

"This micro-projector functions using tiny mirrors of less than a millimeter’s thickness. Positioned on a silicon (wafer) disc, they reflect red, blue and green laser beams,” says EPFL research director Maher Kayal.

It oscillates so quickly that the beam can scan a surface up to 20,000 times a second, and has been able to generate a color image in VGA resolution (640 x 480px).

“The micro-components used can be manufactured in thousands, even tens of thousands, at low cost,” says Nicolas Abelé, Lemoptix technical director.

The initial applications are likely to be industrial. For example, it could be used by automobile manufacturers to project information such as speed and location directly onto the windshield.

Medical technology companies have already shown an interest, as the technology could be used to beam information related to an operation directly onto the patient, without the surgeon needing to look at a screen.