Dual Lens Could Acquire, Display Images

Hank Hogan

Meaningful communication, whether between people or machines, can sometimes be challenging. Before something like Dick Tracy's two-way wrist videophone can appear, the problems of both capturing and displaying images must be solved. Researchers at Cambridge University in the UK and Edith Cowan University in Joondalup, Australia, have proposed a dual-purpose lens system to accomplish this give-and-take for mobile video communication.

A design for a dual-purpose lens system promises to improve mobile video communications. The inner region of the lens would create a virtual display (left), and the ringlike outer region would capture and focus images on an intelligent pixel (IP) processor for transmission (right). Courtesy of Neil Collings.

According to Neil Collings, one of the researchers at Cambridge, the approach solves this problem through a divide-and-conquer concept. He explained that the lens system would work in conjunction with an intelligent pixel processor, comprising an array of photodiodes and liquid crystal spatial light modulators. The photodiodes would capture the images at the source, and the liquid crystal elements and photodiodes would combine to display the ones transmitted from afar.

In the proposed system, the lens would be divided into an inner region and an outer, ringlike one. The former would create virtual images that would appear to float behind the processor. In reality, the image would be formed by the intelligent pixel processor and magnified for easy viewing. The outer region would act as standard imaging optics, capturing the scene and focusing it on the intelligent pixel processor for transmission.

The idea is that handheld multimedia communication devices would use such a composite lens system to enable people equipped with them to talk to one another using wireless technology and to look as if they were making eye contact. The system would offer both a camera and a display in one, compact unit.

Although calculations indicate that the communicators should work, they have not yet been built. There are many hurdles to overcome before such devices become available, and Collings said that the Cambridge group is working on some of the required solutions, including data compression, to allow the video signals to be incorporated at the transmission bandwidth.