Motorized and Calibrated Lenses for Machine Vision Applications

Many applications have benefited from motorized varifocal lenses that allow automatic or remote adjustment of focus distance and field of view. Applications may need to change the focal length or object focus distance on the fly to maintain a sharp image. Or access to the lens may be restricted by environmental housing or other external factors. A lens that offers remote or automatic adjustment of focus and focal length can be a benefit. However, with this added flexibility there are some challenges.

Variations in manufacturing and tolerances lead to slight and sometimes significant differences from lens to lens. The lenses can be calibrated for these variables, and the calibration data can be used to improve the performance and speed of using the lens.

Peterson highlights calibrated lenses that are individually characterized and calibrated to provide a rich array of data sets depending on the lens features, including focal length, f-number, focus/zoom motor positional relationship, as well as custom calibrations.

The calibrated data is provided so the user can optimize image quality in real-time and possibly without the requirement to use difficult or costly field calibration fixtures. Calibrated data is a combination of data unique to the individual lens and design data common across all lenses of the same model. This data is available for download from a cloud database along with application notes providing some options for using the data. The system integrator can access the data via a non-proprietary format using the integrator’s embedded computer which is responsible for image processing and interpretation. Integrators can optimize the image with individual lens data in their own applications. There are many points in an optical imaging system that can limit performance.

Applying the exact image characterization parameters from each individual lens can improve image quality. The improvement amount may be small for each characterization parameter but many incremental changes in multiple imaging parameters can lead to a noticeable overall improvement in image quality. This presentation examines several examples of improvement.

About the presenter
Mark Peterson is a co-founder and vice president of advanced technology of Theia Technologies. He enjoys investigating new technologies that can improve and advance Theia's line of products and solutions, allowing Theia to be a leader in optics and imaging. Peterson believes that understanding a broad range of technologies and bringing together ideas from different areas is fundamental to building exciting new products that allow customers to accomplish their goals.

Prior to founding Theia Technologies, Peterson worked in advanced development at InFocus Systems. There, he and Jeff Gohman, the president of Theia Technologies, developed the core technologies for creating ultra-wide angle low distortion lenses that allowed Theia to spin off.

Peterson has over 40 patents and has contributed to conferences on machine vision and white papers on optics and lenses. He has a bachelor’s and master’s degree from the University of Wisconsin and has been working in the optics industry for 25 years. In his time outside the office Peterson is leader of a pack of three malamutes and puts in lots of miles on his road bike. Peterson and his wife, Lynn, are trying to minimize their environmental footprint and recently built a small home on their property in Lake Oswego, Oregon.