Stephen Alvin Schrader

US Patent:

48598631, Aug 22, 1989

Filed:

Jan 11, 1988

Appl. No.:

7/142800

Inventors:

Stephen A. Schrader - Bridgeton MO
Douglas J. Goff - Kirkwood MO

Assignee:

Sonoco Products Company - Hartsville SC

International Classification:

G06K 500
H04N 718

US Classification:

250556

Abstract:

A label inspection apparatus for inspecting labels on containers moving by a conveyor past the inspection apparatus senses the reflectivity values of pixels located over substantially the entire label for each container in a sample having a predetermined number of containers. The pixel locations are the same for each label in the sample and each label to be inspected, and the containers and labels in the sample are typical of those to be inspected. From the reflectivity values MEANS and standard deviation values are established for the containers in the sample. Limits by which containers to be inspected are to be judged as pass or fail are established as a function of the MEANS and standard deviations values. The reflectivity value in each pixel in each label to be inspected is sensed as with the containers in the sample, and a function of these values is compared with the estabilished limits, and from the comparison a label is passed or failed.