Advanced Imaging


Industry News

Updated: July 8th, 2008 05:26 PM CDT

Designing a Better Chip: Keep an Eye on This New CMOS Sensor

via NewsEdge Corporation

The geeks are hard at work in the lab at the University of Rochester. A pair of new technologies may soon enable power-hungry imaging chips to use just a fraction of the energy needed today and capture better images as well--all while someday enabling cameras to shrink to the size of a shirt button and run for years on a single battery.

The team of Mark Bocko, professor of electrical and computer engineering, and Zeljko Ignjatovic, assistant professor of electrical and computer engineering, has designed a prototype chip that can digitize an image at each pixel on a sensor. Now they are working to incorporate a second technology that will compress the image with far fewer computations than the best current compression techniques.

The first technology integrates an oversampling "sigma-delta" analog-to- digital converter at each pixel location in a CMOS sensor. Previous attempts to do this on"pixel conversion have required far too many transistors, leaving too little area to collect light. The new designs use as few as three transistors per pixel, reserving nearly half of the pixel area for light collection.

The second advance--called "Focal Plane Image Compression"-- arranges photodiodes on a chip so that compressing the resulting image demands as little as one percent of the computing power usually needed. Normally, the light"detecting diodes on a chip are arranged in a regular grid--say 1,000 pixels by 1,000 pixels. When the image hits the diodes, a computer must process each and then compress the entire image. This compression technique takes a tremendous amount of computer processing and, hence, battery power.

Ignjatovic and Bocko came up with a way to make the physical layout of the light"sensitive diodes simplify the computation, reducing the needed computing power five-fold. Stay tuned.

[Copyright 2006 Access Intelligence, LLC. All rights reserved.]

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