The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 03, 1988
Filed:
Aug. 18, 1986
Jeffrey D Taft, Murrysville, PA (US);
James F Ellison, Pittsburgh, PA (US);
Westinghouse Electric Corp., Pittsburgh, PA (US);
Abstract
The present invention includes a surface inspection system with a single light source producing two light stripe sheets projected from different angles onto an inspected surface so that a combined light sheet produces a light stripe image with no shadows results. The two light stripe sheets are created by tangentially reflecting a laser beam off of separate cylindrical reflectors. The light stripe is detected by an imaging system, including a camera having a CCD image array, held at a fixed angle with respect to the light sheet which allows the two-dimensional curvature of the stripe to be detected. The two-dimensional light stripe image is converted into a digital image and processed by linear and logical digital filters that narrow the stripe down to two pixels wide. A coordinate extraction apparatus extracts the coordinates of the bottom row of the pixel image producing a digital representation of the light stripe curve. The sample curve is compared by a computer with a reference curve by obtaining the absolute value of the difference in height of points along the sample and reference curves after alignment and comparing the absolute value to an error or tolerance threshold. Any deviation beyond the fixed tolerance is reported as a surface irregularity defect.