By Radiant Vision Systems (www.RadiantVisionSystems.com)
There are three main approaches to visual inspection of illuminated displays in highspeed production – whether in line, or at the end of the line in final inspection:
1) Human inspection – Easily handles moderately complex testing requirements. Relatively slow and variable when compared to electronic testing methods
2) Machine vision-based inspection – Very fast for simple tests. Does not reflect human visual experience for many tests
3) Imaging colorimeter-based inspection – Somewhere between the preceding two methods in speed. “Sees” like humans with a very high degree of reliability and repeatability
The use of imaging colorimeter systems and associated analytical software to assess display brightness, color uniformity, and contrast, and to identify defects in displays, is well established. A fundamental difference between imaging colorimetry and machine vision is imaging colorimetry’s accuracy in matching human visual perception for light and color uniformity (and non-uniformity).
In this paper, we describe how imaging colorimetry can be used in a fully-automated testing system to identify and quantify defects in high-speed, high-volume production environments. We cover the test setup, and the range of tests that can be performed – spanning simple point defect detection through complex mura detection and evaluation...
For a full version, you can download the attached file.