US4607271A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic field sensor
Assignee: Siemens Building Technologies AG
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Filing: 1983-11-14
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Granted: 1986-08-19
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Expires: 2003-11-14
Abstract
Abstract The magnetic field sensor is composed of a semiconductor magnetic field sensor, for example a magnetotransistor, and at least one NiFe or NiCo film disposed upon its surface. This film functions as a zero-crossing switch utilizing its magnetic induction/magnetic field-reversal hysteresis properties. The film is deposited immediately above the field sensitive zone of the magnetic field sensor with its easy axis oriented perpendicularly to the direction of current flow of the sensor. The semiconductor magnetic field sensor detects the magnetic induction generated by the film.
Inventors
- 👤 Radivoje Popovic
- 👤 Jean-Luc Berchier
- 👤 Gernot Schneider
- 👤 Heinz Lienhard
- 👤 Heinrich P. Baltes
- 👤 Katalin Solt
- 👤 Tomislav Zajc
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 18:03
CPC Classifications
G; G01; G01R; G01R33/00; G01R33/02; G01R33/06; H; H10; H10D; H10D48/00; H10D48/40
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
106 words
A sensor for detecting field reversals in a magnetic field comprising: a magnetic field sensitive semiconductor device, a thin film comprising nife or nico which functions as a magnet formed on a surface of said magnetic field sensitive semiconductive device, said film having a direction of magnetization which is capable of reversal in response to said field reversals of said magnetic field, said film being free of any electrical contacts thereto so that substantially no electrical current flows in said film, said magnetic field sensitive semiconductor device being adapted to produce an electrical signal in response to reversals in the direction of magnetization of said film.
Claim 2
Dependent Claim
106 words
A sensor for detecting field reversals in a magnetic field comprising: a magnetic field sensitive semiconductor device, a thin film comprising nife or nico which functions as a magnet formed on a surface of said magnetic field sensitive semiconductive device, said film having a direction of magnetization which is capable of reversal in response to said field reversals of said magnetic field, said film being free of any electrical contacts thereto so that substantially no electrical current flows in said film, said magnetic field sensitive semiconductor device being adapted to produce an electrical signal in response to reversals in the direction of magnetization of said film.
Claim 3
Dependent Claim
30 words
A sensor as claimed in claim 1, wherein said film comprises two film portions separated by an air gap, said film portions having easy axes which are aligned substantially parallel.
Claim 4
Dependent Claim
17 words
A sensor as claimed in claim 2 wherein both of said film portions have rectangular plan forms.
Claim 5
Dependent Claim
32 words
A sensor as claimed in claim 2, wherein mutually opposing ends of said film portions adjacent to the air gap are shaped to focus the magnetic field produced by said film portions.
Claim 6
Dependent Claim
38 words
A magnetic field sensor as claimed in claim 4 wherein one film portion has an end adjacent the air gap which is pointed and the other film portion has an end adjacent the air gap which is concave.
Claim 7
Dependent Claim
108 words
The sensor of claim 1 wherein said semiconductor device is a magnetotransistor comprising a relatively weakly doped semiconductor substrate of a first conductivity type, a relatively weakly doped base region of a second conductivity type formed in said substrate, a relatively highly doped emitter region of said first conductivity type formed at a surface of said base region, a relatively highly doped collector region of said first conductivity type formed at said surface of said base region, and a passivating layer formed on said surface of said base region between said emmitter and said collector, said film which functions as a magnet being formed on said passivating layer.
Claim 8
Dependent Claim
29 words
A magnetic field sensor as claimed in claim 6, wherein said emitter region is shallower than any of said other regions but has a depth greater than 0.5 μm.
Claim 9
Dependent Claim
21 words
A magnetic field sensor as claimed in claim 6, wherein said emitter region has a sheet resistivity greater than 100 ohms/□.
Claim 10
Dependent Claim
49 words
A sensor as claimed in claim 6 wherein said sensor further includes a second magnetotransistor, said second magnetotransistor being devoid of any film which functions as a magnet, said magnetotransistor having said film formed thereon being interconnected with said magnetotransistor devoid of said film to form a differential amplifier.
Claim 11
Dependent Claim
32 words
The sensor of claim 6 wherein a current flows between said emmitter and collector and wherein said film has an easy axis for magnetization oriented perpendicular to the direction of current flow.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-08-18 | 1990-02-17 | 1990-08-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-08-18 | 1994-02-17 | 1994-08-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-08-18 | 1998-02-17 | 1998-08-19 | $7700.00 | Window Closed / Lapsed |