IMAGE SAMPLER APPARATUS
By Laurence G. Hassebrook and Geethavani Goli
Department of Electrical and Computer Engineering
In collaboration with the Center for Manufacturing Systems.
The “Image Sampler” is a test apparatus that allows us to image samples mounted on 35mm slide mounts. The samples presented here are translucent polycarbonates which have non-stationary flaws positioned randomly in a stationary background. The illumination used is a polarized bright field. The main turret has 6 sub-turrets. The main turret can remain stationary and individual turrets manually turned to generate rotated data sets for a single type of defect. Another scenario is to have the main turret turn to collect data for up to 6 types of defects. The main turret is turned by a small geared dc motor and an optical encoder is used to sense rotation angle and thus allow image capture of each sub-turret sample. One particular application of the Image Sampler was to develop a reliable detection algorithm for non-stationary defects which also led to the concept design of a polycarbonate web scanner.
Figure 1: Image Sampling Apparatus.
Figure 2: Overview of Defect Detection Algorithm.
Figure 3: Architecture of Image Sampler.
Figure 4: Main Software Screen of Image Sampler showing input image upper left and detected defect lower right.
Figure 5: Proposed scanner based on results of Image Sampler.
Figure 6: Proposed scanner control architecture.
Figure 7: Proposed scanner linear array camera design specifications.
Figure 8: Summary of proposed scanner.