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:
Sep. 26, 1989
Filed:
May. 06, 1985
Applicant:
Inventors:
Alan J Collins, Risca, GB;
Mazen R Husni, Llanedeyrn, GB;
Assignee:
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G01N / ; G01R / ; G07F / ;
U.S. Cl.
CPC ...
324235 ; 324251 ; 324252 ; 324207 ; 194317 ; 194318 ;
Abstract
When an electrically conducting material is subjected to an alternating magnetic field local changes in the magnetic field adjacent to the conducting material are detected by a detector comprising a magnetoresistor or Hall crystal which generate an electrical signal when subjected to the magnetic field. The process and apparatus can be used to identify, classify and locate electrically conductive material. The detectors can be of the order of a few millimeters in size and so can be used to detect local changes in the magnetic field over correspondingly small areas of the material. The invention is particularly useful in identifying coins used in coin operated machines.