US3835377A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Three terminal magnetoresistive magnetic field detector in which voltages of opposite polarity relative to ground are applied to opposite ends
Assignee: National Institute of Advanced Industrial Science and Technology
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Filing: 1973-03-28
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Granted: 1974-09-10
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Expires: 1993-03-28
Abstract
Abstract Disclosed herein is a detector of local magnetic field, in which metallic electrodes are connected to the both ends and central part of at least one semiconductor having a magneto resistive characteristic thereby to form at least one magneto resistive element having three terminals, said element being arranged on a plane, whereby presence of a local magnetic field in said element can be detected from a voltage appearing across each of the central electrodes of said elements and a predetermined reference point. In addition, a semiconductor displacement transducer is also disclosed, which serves to produce an output voltage having any of the polarity, positive or negative, corresponding to a magnetic field displacement, by displacing the magnetic field applied to a part of the magnetoc resistive element with three terminals.
Inventors
- 👤 S Kataoka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 05:44
CPC Classifications
G; G01; G01R; G01R33/00; G01R33/02; G01R33/06; G01R33/09
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
182 words
A contactless device for detecting the position of a local magnetic field comprising: a. a magnetoresistive element; b. a pair of end electrodes disposed at opposite ends of said magnetoresistive element and a central electrode disposed on said magnetoresistive element midway between said end electrodes; c. means for developing a local magnetic field having an extent less than a distance between said central electrode and one of said end electrodes, said means for developing a local magnetic field comprising means for applying said local magnetic field to either areas of said magnetoresistive element defined between said central electrode and said end electrodes respectively; d. a ground electrode; e. means for applying each of a pair of voltages between said ground electrode and a respective one of said end electrodes, said pair of voltages being applied in use and having equal magnitudes and opposite polarities; and f. output means for providing an output voltage developed in use between said central electrode and said ground electrode, said output voltage being representative of a position of said local magnetic field relative to said magnetoresistive element.
Claim 2
Dependent Claim
182 words
A contactless device for detecting the position of a local magnetic field comprising: a. a magnetoresistive element; b. a pair of end electrodes disposed at opposite ends of said magnetoresistive element and a central electrode disposed on said magnetoresistive element midway between said end electrodes; c. means for developing a local magnetic field having an extent less than a distance between said central electrode and one of said end electrodes, said means for developing a local magnetic field comprising means for applying said local magnetic field to either areas of said magnetoresistive element defined between said central electrode and said end electrodes respectively; d. a ground electrode; e. means for applying each of a pair of voltages between said ground electrode and a respective one of said end electrodes, said pair of voltages being applied in use and having equal magnitudes and opposite polarities; and f. output means for providing an output voltage developed in use between said central electrode and said ground electrode, said output voltage being representative of a position of said local magnetic field relative to said magnetoresistive element.
Claim 3
Dependent Claim
45 words
A contactless device for detecting the position of a local magnetic field according to claim 1 wherein said means for developing a local magnetic field comprises an orthofeRrite substrate disposed adjacent said magnetoresistive element, said orthoferrite substrate having at least one magnetic bubble domain therein.
Claim 4
Dependent Claim
43 words
A contactless device for detecting the position of a local magnetic field according to claim 1 wherein said means for developing a local magnetic field comprises means defining a magnetic circuit having a portion thereof adjacent said magneto-resistive element and moveable relative thereto.
Claim 5
Dependent Claim
43 words
A contactless device for detecting the position of a local magnetic field according to claim 1 including a plurality of magnetoresistive elements arranged in at least one straight line wherein respective end electrodes disposed on said magneto-resistive elements are electrically connected in parallel.
Claim 6
Dependent Claim
56 words
A contactless device for detecting the position of a local magnetic field according to claim 1 including a plurality of magnetoresistive elements disposed along a first straight line and disposed along a second straight line perpendicular to said first straight line whereby the position of said local magnetic field may be detected along two perpendicular dimensions.
Claim 7
Dependent Claim
42 words
A contactless device for detecting the position of a local magnetic field according to claim 1 including a plurality of magnetoresistive elements disposed in a concentric circular pattern wherein respective end electrodes disposed on said magnetoresistive elements are electrically connected in parallel.
Claim 8
Dependent Claim
265 words
A contactless device for detecting the position of a local magnetic field comprising detection means for developing a trinary bipolar digital output signal representative of a position of the detected local magnetic field, said detection means comprising: a. a magnetoresistive element; b. a pair of end electrodes disposed at opposite ends of said magnetoresistive element and a central electrode disposed on said magnetoresistive element midway between said end electrodes; c. means for developing a local magnetic field having an extent less than a distance between said central electrode and one of said end electrodes, said means for developing a local magnetic field comprising means for applying said local magnetic field to either of areas of said magnetoresistive element defined between said central electrode and said end electrodes respectively; d. a ground electrode; e. means for applying each of a pair of voltages between said ground electrode and a respective one of said end electrodes, said pair of voltages being applied in use and having equal magnitudes and opposite polarities; and f. output means for providing an output voltage developed in use between said central electrode and said ground electrode, said output voltage having a first polarity when said local magnetic field is applied to said magnetoresistive element between said central electrode and a first of said end electrodes, said output voltage having a second polarity when said local magnetic field is applied to said magnetoresistive element between said central electrode and the second of said end electrodes, and said output voltage having zero magnitude when no local magnetic field is applied to said magnetoresistive element.
Claim 9
Dependent Claim
265 words
A contactless device for detecting the position of a local magnetic field comprising detection means for developing a trinary bipolar digital output signal representative of a position of the detected local magnetic field, said detection means comprising: a. a magnetoresistive element; b. a pair of end electrodes disposed at opposite ends of said magnetoresistive element and a central electrode disposed on said magnetoresistive element midway between said end electrodes; c. means for developing a local magnetic field having an extent less than a distance between said central electrode and one of said end electrodes, said means for developing a local magnetic field comprising means for applying said local magnetic field to either of areas of said magnetoresistive element defined between said central electrode and said end electrodes respectively; d. a ground electrode; e. means for applying each of a pair of voltages between said ground electrode and a respective one of said end electrodes, said pair of voltages being applied in use and having equal magnitudes and opposite polarities; and f. output means for providing an output voltage developed in use between said central electrode and said ground electrode, said output voltage having a first polarity when said local magnetic field is applied to said magnetoresistive element between said central electrode and a first of said end electrodes, said output voltage having a second polarity when said local magnetic field is applied to said magnetoresistive element between said central electrode and the second of said end electrodes, and said output voltage having zero magnitude when no local magnetic field is applied to said magnetoresistive element.
Claim 10
Independent Claim
185 words
A method for developing a voltage signal representative of a position of a local magnetic field comprising: a. providing a magnetoresistive element having a pair of end electrodes disposed at opposite ends thereof and a central electrode disposed midway between said end electrodes; b. applying a pair of voltages having equal magnitude and opposite sign between ground and respective ones of said end electrodes; c. moving said magnetoresistive element relative to a local magnetic field the position of which is to be detected while said pair of voltages are applied to said end electrodes, said local magnetic field having an extent less than a distance between said central electrodes and said end electrodes, and d. detecting an electrical output voltage signal developed between said central electrode and ground, said Output voltage having a first polarity when said local magnetic field is adjacent said magnetoresistive element between a first of said end electrodes and said central electrode and said output voltage having a second polarity when said local magnetic field is adjacent said magnetoresistive element between the other of said end electrodes and said central electrode.
Claim 11
Independent Claim
185 words
A method for developing a voltage signal representative of a position of a local magnetic field comprising: a. providing a magnetoresistive element having a pair of end electrodes disposed at opposite ends thereof and a central electrode disposed midway between said end electrodes; b. applying a pair of voltages having equal magnitude and opposite sign between ground and respective ones of said end electrodes; c. moving said magnetoresistive element relative to a local magnetic field the position of which is to be detected while said pair of voltages are applied to said end electrodes, said local magnetic field having an extent less than a distance between said central electrodes and said end electrodes, and d. detecting an electrical output voltage signal developed between said central electrode and ground, said Output voltage having a first polarity when said local magnetic field is adjacent said magnetoresistive element between a first of said end electrodes and said central electrode and said output voltage having a second polarity when said local magnetic field is adjacent said magnetoresistive element between the other of said end electrodes and said central electrode.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-09-09 | 1978-03-11 | 1978-09-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-09-09 | 1982-03-11 | 1982-09-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-09-09 | 1986-03-11 | 1986-09-10 | $7700.00 | Window Closed / Lapsed |