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:
May. 30, 1995
Filed:
Apr. 28, 1994
Steven K Harbaugh, Castro Valley, CA (US);
Authentication Technologies, Inc., Dublin, CA (US);
Abstract
A currency paper has a security thread embedded therein. The thread comprises a plastic substrate having a plurality of alphanumeric, metallic, electrically-conductive characters formed thereon. The characters have predetermined heights and widths and spacings therebetween. The verification device comprises an oscillator electrode and associated horizontal and vertical electrodes. A time-varying oscillator signal is coupled to the oscillator electrode. The spacing of the horizontal and vertical electrodes in relation to the oscillator electrode is determined by the spacing between the metallized characters on the thread. A valid security thread capacitively couples the oscillator signal into the horizontal electrode but not the vertical electrode. On the other hand, a counterfeit security thread will couple the oscillator signal into both the horizontal and vertical electrodes. Signal processing electronics is provided to sense these valid and counterfeit conditions.