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:
Aug. 16, 1983
Filed:
Aug. 21, 1981
Applicant:
Inventor:
Elwood E Barnes, Parkesburg, PA (US);
Assignee:
Mars, Inc., McLean, VA (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G07F / ;
U.S. Cl.
CPC ...
1941 / ; 1941 / ; 73163 ;
Abstract
A method and apparatus for coin examination which subjects one side of a coin to a low frequency electromagnetic field from a transmitter inductor driven by an astable oscillator and frequency divider, receives a portion of the field on the other side of the coin with a receiving inductor, amplifies the output of the receiving inductor with a non-linear amplifier, and measures the phase shift between the signal driving the transmitter inductor and the amplifier output.