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:
Oct. 25, 1994
Filed:
Nov. 25, 1992
Elwood E Barnes, Cochranville, PA (US);
Mark H Kryder, Bradford Woods, PA (US);
Keith R Mountfield, Pittsburgh, PA (US);
Mars Incorporated, McLean, VA (US);
Abstract
An apparatus and method for detecting magnetic data on media is disclosed which utilizes an array or arrays of horizontal magnetoresistive sensors. The present invention detects the pitch or separation of magnetic transition data on the magnetic medium under test, and generates a signal that is independent of the velocity of the medium. In one embodiment, the magnetoresistive sensors employed in an array are spaced apart a distance which corresponds to the separation of magnetic transition data of interest, and the output of each sensor is connected to a voltage adder. The signal from the voltage adder is at a maximum when the separation of the magnetic transition data corresponds to the sensor separation. A comparator is connected to the output of the voltage adder, and compares the voltage adder output to a predetermined threshold voltage before indicating that a medium having a particular magnetic transition data pattern is detected. Alternate embodiments contemplate connecting linear circuitry, digital circuitry, fuzzy logic or other electronic circuitry to the array of magnetoresistive sensors. An apparatus according to the present invention is accurate, requires a minimum of parts, is simple and inexpensive to manufacture, and may be employed in a currency validator, magnetic card reader or the like.