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:
Apr. 19, 1994
Filed:
Dec. 11, 1991
Henry C Kowalski, Grand Blanc, MI (US);
GMI Engineering and Management Institute, Flint, MI (US);
Abstract
A birefringent inspection polariscope for inspecting relatively transparent objects for defects is disclosed as having a source of white light to emit light along a path and, positioned in the path, a retarder to diffuse light from the source thereof, a fixed polarizer to circularly polarize the light and a fixed, circularly polarizing analyzer to convert circularly polarized light emanating from the polarizer to plane polarized light. An inspection area, in which to position an object to be inspected, is provided between the polarizer and the analyzer; and a lens is positioned to magnify light emanating from the analyzer. Also provided is a half-wave plate that can be positioned in the path of light to provide a dark background field to facilitate photographic recording.