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:
Jul. 16, 1991
Filed:
Apr. 22, 1988
Bruce R Morrison, Jamberoo, AU;
John S Lake, Balgownie, AU;
John Lysaght (Australia) Limited, Sydney, AU;
Abstract
A high resolution CCD video camera (6) is positioned and aligned with respect to an illuminated article (7) so that a straight edge of the article, or a straight line junction between a bright zone and a dark zone of its surface, crosses the field of view of the camera in a direction substantially parallel to the rows of the camera's orthogonal array of rows and columns of light responsive elements, to divide that field of view into bright and dark zones. A frame store and digitizer (9) converts the individual signals generated by the elements into digital grey values. The grey values derived from the elements of each row are summed by a computer (10) to produce a linear array of summation values positionally related to the respective columns, and the computer then determines the position of the edge or junction to a sub-column spacing accuracy by determining the mean value of two of the summation values selected respectively from a row receiving energy from the bright zone and one receiving energy from the dark zone and establishing a position in the array for the mean value, and thus for the feature, by interpolating the mean value between the two summation values immediately above and below it in magnitude.