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:
Mar. 18, 1980
Filed:
Mar. 17, 1978
Applicant:
Inventor:
Walter Schmidt, Lenzburg, CH;
Assignee:
Swiss Aluminium Ltd., Chippis, CH;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G01N / ;
U.S. Cl.
CPC ...
250572 ; 356371 ; 356445 ;
Abstract
Polished single crystal wafers are checked for defects by means of a method employing a optical microscope. The image is blurred by a translucent material and the transmitted light is then sensed by a light sensitive instrument which records the increased light intensity caused by a defect passing through the field of view. The position of the defects are then plotted automatically.