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. 04, 1991
Applicant:
Inventors:
Peter Y Zhou, Smithtown, NY (US);
John Dunn, Merrick, NY (US);
Charles D Graham, Ardmore, PA (US);
Kyung-Ho Shin, Philadelphia, PA (US);
Assignee:
Knogo Corporation, Hauppauge, NY (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G08B / ;
U.S. Cl.
CPC ...
340572 ; 340505 ; 340526 ; 148108 ;
Abstract
A responder for electronic article surveillance apparatus is made by subjecting a plurality of magnetizable elements to heating in the presence of a magnetic field and maintaining the field at a different intensity for each element as it is cooled to provide different magnetic characteristics so that when the responder is subjected to a cyclically varying magnetic interrogation field its several elements produce spaced apart pulses in each cycle.