Photonics Spectra - March 2009

For microscopes, a new way is at hand

BY HANK HOGAN, CONTRIBUTING EDITOR

Sa thousand words – or a thousand dollars. That’s the case for CGI, a company based in Eden Prairie, Minn., which sells proprietary inspection systems for small, plastic injection-ometimes a picture is worth more than

molded parts. CGI’s systems slice through these parts and take high-resolution pictures, repeating the process to capture a complete three-dimensional image. That data provides vital information about the manufacturing process, which is why businesses all over the world buy the company’s inspection tools.

But the usefulness of the data depends on the quality of the cut, and that involves trade-offs. A diamond-tipped cutter, for instance, might yield a cleaner slice than a more standard cutter, but it does so at greater cost. CGI president Craig Crump noted that conveying the difference between those cuts is now easier, thanks to handheld microscopes.

“You can describe it verbally, but you don’t capture it nearly as well as you do with one of these little handheld devices,” he said.

That’s just one example of what handheld microscopes are being used for. For those who need a close-up look at something away from the lab, the solution may be at hand – literally. Thanks to advances in imagers, algorithms and optics, handheld microscopes are now available that allow the inspection of components, circuit boards, coins, stamps and skin, meeting the needs of industry and consumers.

These devices likely won’t replace conventional microscopes, but already they have proved to be useful. A look at offerings from Bodelin Technologies of Lake Oswego, Ore., Keyence Corp. of Osaka, Japan, and Celestron LLC of Torrance, Calif., reveals where handheld microscopy is now and where it’ll be in the future.

With the click of a button

According to CGI’s Crump, the company uses the Bodelin ProScope only for qualitative images. Actual inspection data is captured by digital cameras at a resolution of 1000 pixels per linear inch. The handheld microscope, in contrast, enables

easy capture and e-mailing of illustrative images to customers worldwide, thereby showing how one cutting option compares to another. The fact that the handheld microscope captures a visible image is important, since the high-resolution cameras used for the actual 3-D reconstruction also image across the same range.

The ProScope has been around for a decade and has experienced changes in its usage patterns and audience, said Bodelin director of sales and marketing Peter White. It originally started off in science education but has since found a home in manufacturing and law enforcement. Those last two categories now account for the bulk of sales.

“Interpol is one of our customers,” said White, who noted that the FBI and military intelligence likewise use the device

A Bodelin ProScope handheld microscope captures a close-up of a part being sliced by a CGI plastic parts inspection system. The image from the microscope illustrates the quality of the cut. Image courtesy of CGI.