Our View

One of the first industrial vision solutions

December 1, 2011 by Jørgen Læssøe

It was fun and challenging to develop and build the first vision systems in Europe in 1980.

Thirty years ago was before the solid state cameras and we had to make use of cameras based on vacuum tubes. These had electromagnetic deflection and could not produce images with accurate geometry. All images were pillow or barrel shaped and they drifted with temperature and time.

It was a challenge to solve the first application which was to measure the straightness of nails for the building industry. A 130 mm long nail should be measured for straightness to +/- 0.1 mm. When we placed the nail in front of the camera we could - just with our eyes - on the CRT monitor, see that the nail was bend (which it was not). The camera and the monitor were not designed for accurate geometry.

The solution was to place a straight strip of metal next to the nail and have the optical centre right between the nail and the strip and then do comparison between the reference and the nail.

The system was developed and it measured accurately – better than -/- 0.1 mm.

Having worked with the old technology you get a lot of expertise in making compensations for geometry, illumination and optical distortions. This is very useful even today where the components we use are dependable and accurate.