Lens Technology Gets All Wet
By Carlo Longino, Thu Dec 02 22:15:00 GMT 2004

Lenses that mimic how the human eye works could prove the next innovation in cameraphones.

Even as the megapixel count of cameraphones increases, image quality is still limited by their tiny fixed-focus lenses, which among other drawbacks, don't gather light well. But one French company is developing liquid-lens technology that uses electrically charged fluids to change the shape of a camera lens, which mimics the human eye, as well as variable-focus camera lenses.

Varioptic's lenses contain water and oil between two clear windows in a conical container, and when voltage is applied, the surface of the liquids becomes curved -- and applying different voltages changes the amount of curvature, in effect giving the lens a variable focal length. Philips Research is also developing liquid lenses, and is working on making a zoom lens, which requires using at least two lenses in tandem.

The technology dates back to the 17th century, when English scientist Stephen Gray built microscopes using water-drop lenses, and builds on research done in the 20th century. Liquid lenses have plenty of potential applications -- possibly including being used to replace human eye lenses in the future -- but given the explosive growth of cameraphones, both companies are focusing on that market. The lenses are a good fit for mobile handsets when combined with a powerful sensor, since they have no moving parts, making them durable, are tiny, and use much less power than a powered autofocus lens.

The Philips team says its technology should be in products within the next year or two; Varioptic has a license deal with Samsung, and says handsets with its lenses will be on sale by the first quarter of 2006 at the latest.