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. 20, 1985
Filed:
Aug. 29, 1984
Tsuyoshi Ishida, Yokohama, JP;
Tokyo Shibaura Denki Kabushiki Kaisha, Kanagawa, JP;
Abstract
The metal detecting device includes first and second coils provided on both sides of a passageway for paper money. This metal detecting device is designed for use in detecting a metal strip embedded in the paper money in order to determine whether the paper money is genuine or counterfeit. The first coil is connected to a high frequency AC source to generate an AC magnetic field. The second coil is connected to a capacitor to form a resonance circuit which resonates at the same frequency as the AC current. The variation of the Q factor of the resonance circuit due to eddy-current losses produced in the metal strip of the paper money is used by a detecting circuit to determine whether the paper money passing through the space between the first and second coils is genuine.