Cameraphones focus on liquid lenses

All it takes is a drop of water

By John Oates, 13th February 2007

Steps to Take Before Choosing a Business Continuity Partner

3GSM The quality of autofocus lenses on cameraphones are set to get a boost with technology from Varioptic, a firm that makes its lenses out of oil and water, rather than using traditional mechanical lenses.

The firm was this week celebrating at 3GSM in Barcelona the first inclusion of its nifty lens in a camera module, one made in China by Taiwanese firm Sunny.

Varioptic makes autofocus lenses for higher spec camera phones. The lens exploits the way water will form a rounded droplet on a surface, which goes flat when voltage is applied to it - a technique known as electrowetting. This has been known for some time, but Varioptic's product is the first optical application.

The lens is cone-shaped and contains oil and water - the junction between the two forms the refractive surface. When voltage is applied to the surface of the cone, the water wets it and the oil expands - effectively changing the focus of the lens.

Varioptic marketing manager Philippe Ruffin told El Reg: "It's much more reliable than mechanical alternatives. It can focus on a shorter distance - to about 5cm - and it's much faster [to focus] than a mechanical lens. On an ordinary module it will work at 800ms but we can tune that to 500ms."

Ruffin said the company's factory in Shanghai has capacity to produce 100,000 lenses a month and its plant in Lyon another 25,000. He said the company expects to take a large share of autofocus camera phones - usually above three megapixels, but also expects it as a way for handset makers to improve two-megapixel or lower-resolution devices.

"The next big story you will hear from us will be a handset deal," he said.