Mirror technique improves camera phone quality

Researchers at the University of California in San Diego have developed a new technique to bring sharp telephoto capability to the sleekest of camera phone.

The trend for ultra-thin phones has made it nearly impossible to include a quality zoom lens.

The thin, wide-angle lenses used in camera phones are great for panoramic shots, but in order to zoom in, cell phone cameras simply stretch pixels – producing a pretty fuzzy close up.

The new technique, developed by engineering professor Joseph Ford and graduate student Eric Tremblay, uses a technique employed by reflective-telescope makers.

Mirrors are used to bounce light back and forth, lengthening the path that the light travels. This increases the potential for magnification without needing to increase the length of the optic.

The lens is made by carving an array of concentric reflective rings into a single optical crystal. The reflective rings increase the optic’s focal length

Light enters through the camera’s aperture and then bounces from ring to ring. It eventually lands on a central sensor which interprets the information and produces close-up telephoto images on the camera’s screen.

The new optic is seven times thinner than a traditional, 35-millimeter refractive lens, and produces similar image quality.

Researchers have applied for a patent on the technology.