Photonics Spectra - March 2009

Reeves would like to have the widest possible range of wavelengths available for inspection of material. The ability to image in the infrared and ultraviolet ranges would be useful, as would being able to look with polarized light. For the most part, though, he’s happy with the current technology.

Holding steady

Keyence is another supplier of handheld microscopes. According to project manager Brian Gaehring, the company has been making these products for two decades, with the latest incarnation appearing last year. These systems, according to Gaehring, offer better imaging than those adapted from something intended to be viewed by eye. “The optics and CCD detector work together to provide sharp and clear observation,” he said.

That detector is a single-chip, 2.1-mega- pixel device, but Keyence wrings out of the setup the equivalent performance of up to a 54-megapixel, three-CCD chip. This feat is accomplished with an actuator that moves the chip in the dead time while images are being captured. This approach does have its drawbacks, among them the requirement for a very accurate actuator. But the benefit is substantial in that the technique eliminates the need for an actual three-chip camera or color filter. The former would make the device more cumbersome and expensive. The latter would reduce resolution.

Another feature of the Keyence handheld microscope is a very large depth of field, with the company claiming a depth 20 times that of a conventional optical microscope. This can be useful when inspecting parts because such things as recessed markings, protruding features and complex structures can all be in focus at the same time.

In addition to a stand, the system also has a software solution to combat the shaking that blurs images. Proprietary pattern recognition algorithms distinguish between image movement due to motion of the object being studied and that caused by movement of the microscope itself. Software then corrects for the motion caused by the microscope, thereby stabilizing the image. Gaehring said that the algorithms do this correction well enough to eliminate any apparent motion during handheld inspection. He noted that this adjustment is possible only because of a powerful graphics processor in the system.

Keyence product sales director Sean Gasparovic pointed out that the lighting is controlled by the system and travels over fiber optics to the lens itself. That

19th INTERNATIONAL TRADE FAIR AND CONGRESS FOR OPTICAL TECHNOLOGIES—COMPONENTS, SYSTEMS AND APPLICATIONS

LIGHT

AT WORK

NEW MUNICH

TRADE FAIR CENTRE

JUNE 15–18, 2009

A LEADING INTERNATIONAL TRADE FAIR DOES NOT ORIENT ITSELF TO STANDARDS. IT IS THE STANDARD. No other exhibition presents innovative optical technologies in direct combination with industrial application sectors for various branches of industry—as “light at work.” That makes LASER World of PHOTONICS the most important business and networking platform for all market leaders, decision-makers and users—just like you.