An optical probe with auto-focusing capability has been designed and tested for non-contact coordinate measurement. The probe is composed of an auto-focus optoelectronic module and a high resolution microscope with a CCD camera. The auto-focus module has been designed to always keep a constant distance from the object surface so that the CCD camera installed in the microscope can capture the best quality of magnified image. Detailed optical principles and design aspects of the probe has been discussed with relevant experimental results.
In addition, a utility PC program has been developed for 2-dimensional measurements. The program can measure a distance, angle, area and circle diameter from the image obtained by the probe.
