Permanent magnet assembly with MR and DC compensating bias

Details Permanent magnet assembly with MR and DC compensating bias Permanent magnet assembly with MR and DC compensating bias

1994-10-28

1997-07-01

O'Shea, Sandra L.

Electricity: measuring and testing

Magnetic

With means to create magnetic field to test material

235449, G01N 2790, G06K 708

Patent

active

056442289

ABSTRACT:
A magnetic assembly for detection and authentication of magnetic documents. The magnetic assembly includes a permanent magnet (PM), first and second magnetically soft high permeability pole pieces shaped to form a tapered, variable gap size magnetic circuit with the permanent magnet. The PM is located at a first gap between the first and second pole pieces. A magnetoresistive (MR) sensing element is located at or near the center of a second gap between said first and second pole pieces. The second gap and MR sensing element are proximate a magnetic document to be sensed. An electrical conductor is adjacent to the MR sensing element, but is electrically insulated therefrom. A direct current is passed through the electrical conductor to create a compensating bias field in the MR element which is combined with the bias field generated by the PM.

REFERENCES:
patent: 3796859 (1974-03-01), Thompson
patent: 3979775 (1976-09-01), Schwartz
patent: 4401944 (1983-08-01), Narimatsu et al.
patent: 4492922 (1985-01-01), Ohkubo
patent: 4523243 (1985-06-01), Billington
patent: 4603365 (1986-07-01), Nakamura
patent: 4703378 (1987-10-01), Imakoshi et al.
patent: 4734644 (1988-03-01), Imakoshi et al.
patent: 5081554 (1992-01-01), Das
patent: 5159511 (1992-10-01), Das
patent: 5351158 (1994-09-01), Shibata
patent: 5418458 (1995-05-01), Jeffers
patent: 5436778 (1995-07-01), Lin et al.
patent: 5450009 (1995-09-01), Murakami

Affiliated with

Also associated with

Rating

Permanent magnet assembly with MR and DC compensating bias does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Permanent magnet assembly with MR and DC compensating bias, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Permanent magnet assembly with MR and DC compensating bias will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-600145