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US 4,538,912 AGranted
Method of and apparatus for inspection of coatings on surfaces
AssigneePPG Industries, Inc.
InventorHugh E. Shaw, Jr.
Life of this patent
Estimating the term…
Abstract
A method of and apparatus for inspecting reflective coatings on a substrate using a polaroid filter to view light reflected from the coating to make variations in coating thickness over a large coated area visible.
Claims9
A method for inspecting coatings on a substrate, comprising the steps of:
- generating energy beams;
- directing said beams toward both a sample coated substrate and at least one reference coated substrate to reflect beams therefrom as sample reflected beams and reference reflected beams respectively;
- positioning an analyzer in the paths of both said sample reflected beams and said reference reflected beams to polarize said sample reflected beams and said reference reflected beams;
- and
- comparing said polarized sample reflected beams and said polarized reference reflected beams to compare color variations on the sample coating and on the reference coating.
2 more elements
A method for inspecting coatings on a substrate, comprising the steps of:
- generating energy beams;
- directing said beams toward at least one coated substrate to reflect said beams therefrom as reflected energy beams;
- positioning an analyzer in the path of said reflected energy beams to polarize said reflected energy beams;
- and
- visually observing said analyzer to detect color variations in the coating on the substrate.
2 more elements
Apparatus for inspecting coatings on a substrate, comprising:
- a light source for generating light beams;
- means for directing said beams toward the coating to be inspected to provide reflected energy beams including at least a portion reflected from the upper surface of the coating;
- means for vertically polarizing said reflected light beams to provide polarized reflected beams;
- and
- means for recording image or shading pattern produced on said polarizing means by said reflected light beams passing therethrough.
2 more elements
Dependencies are inferred from the claim text.