Keyence has developed a 2D measuring system that combines the roles of a laser scan micrometer, a machine vision system and an optical comparator, in one device. The TM-3000 instrument – described as the world’s first in-line 2D micrometer – can be used either for 100% inspection on high-speed automation lines, or for off-line measurement and inspection.

The device (above) can be used to measure hole diameters, centre pitches, intersection points, radii, widths, angles, perpendicular distances and areas. Because it works in two dimensions, the system can measure up to 16 points in an area.

Using four processors for parallel processing and two dedicated image-processing DSPs, the instrument can process 1,800 images per minute. Repeatability is said to be ±0.15µm.

Expensive target positioning mechanisms are not needed to ensure precision. A position correction function automatically orients the test part before it is measured, thus increasing accuracy.

In use, a dual telecentric lens creates a uniform collimated light using a green LED. A 2D CMOS array then detects the light-to-dark transitions to measure the dimensions. To maintain high speed and precision, sub-pixel processing is performed only in those areas or points designated for measurement.