Publishing Venue
Motorola
Related People
Authors:
Jeff Beals
•
Jeff Hawthorne
Abstract
Machine vision systems are a necessary part of many modern manufacturing processes such as electronic assembly involving fine pitch devices. One of the most difficult tasks in the development of a machine vision system is the design of an illumination system which can reliably generate images suitable for machine processing. Design of a lighting system requires information on the reflective properties of the materials to be imaged. Of particular importance is information concerning the directional and spectral reflectances of the materials.
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Technical Developments Volume 11 October 1990
MATERIAL REFLECTANCE CHARACTERISTICS APPLIED TO IMAGE ACQUISITION FOR MACHINE VISION
by Jeff Beals and Jeff Hawthorne
Machine vision systems are a necessary part of many modern manufacturing processes such as electronic assembly involving fine pitch devices. One of the most difficult tasks in the development of a machine vision system is the design of an illumination system which can reliably generate images suitable for machine processing. Design of a lighting system requires information on the reflective properties of the materials to be imaged. Of particular importance is information concerning the directional and spectral reflectances of the materials.
Present design techniques involve inefficient trial-and-error methods which eventually result in "acceptable" lighting systems, A superior method is to use a spectrophotometer to quantitatively analyze the directional and spectral reflective properties of the materials. This information can then be used to design an illumination system which is optimized for those materials. Spectmphotometer data is usually used in chemical analysis, where minima in the measured reflec- tance or transmittance spectrum indicate absorption energies which provide clues to the chemical composition of the material. This same technique can be used to identify reflective properties which can be exploited in the design of il- lumination systems for machine vision applications.
This technique has been...
