US4945446A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic field compensating apparatus
Assignee: Mitsubishi Electric Corp
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Filing: 1988-06-22
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Granted: 1990-07-31
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Expires: 2008-06-22
Abstract
Abstract A magnetic field compensating apparatus having a plurality of compensating units comprising a plurality of serial coils each of which is disposed concentrically along the main magnetic field and symmetrically with regard to a plane perpendicular to the main magnetic field and a plurality of power sources which separately supply currents to these compensating units, and made in such a manner that a plurality of error magnetic field components are generated by each of the compensating units, a compensating magnetic field is obtained by the whole of a plurality of the compensating units, and each of the currents supplied to the compensating units is decided in accordance with a constitution of a corresponding compensating unit.
Inventors
- 👤 Shigenori Kuroda
- 👤 Moriaki Takechi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 14:16
CPC Classifications
G; G01; G01R; G01R33/00; G01R33/20; G01R33/28; G01R33/38; G01R33/387; G01R33/3875; G01R33/381; G01R33/3815
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
210 words
A magnetic field compensating apparatus for compensating error magnetic fields in the radial direction of a magnet apparatus used for a magnetic resonance apparatus comprising: a plurality of compensating units comprising a plurality of serial coils each of which is disposed concentrically along a main magnetic field and symmetrically with regard to a plane perpendicular to said main magnetic field, a plurality of power sources which separately supply currents to these compensating units, and made in such a manner that a plurality of components among said error magnetic fields in the radial direction are contained in each of said compensating units, a plurality of said components are compensated by the whole of a plurality of said compensating units, and, at the same time, each of said currents supplied to said compensating units is decided in accordance with a constitution of each of said compensating units, said plurality of said compensating units comprising a first compensating unit composed of four saddle-shaped coils disposed cylindrically, a second compensating unit composed of four saddle-shaped coils disposed cylindrically pair by pair on both sides of the first compensating unit, and a third compensating unit composed of four saddle-shaped coils piled and disposed concentrically on each of said saddle-shaped coils of said first compensating unit.
Claim 2
Dependent Claim
210 words
A magnetic field compensating apparatus for compensating error magnetic fields in the radial direction of a magnet apparatus used for a magnetic resonance apparatus comprising: a plurality of compensating units comprising a plurality of serial coils each of which is disposed concentrically along a main magnetic field and symmetrically with regard to a plane perpendicular to said main magnetic field, a plurality of power sources which separately supply currents to these compensating units, and made in such a manner that a plurality of components among said error magnetic fields in the radial direction are contained in each of said compensating units, a plurality of said components are compensated by the whole of a plurality of said compensating units, and, at the same time, each of said currents supplied to said compensating units is decided in accordance with a constitution of each of said compensating units, said plurality of said compensating units comprising a first compensating unit composed of four saddle-shaped coils disposed cylindrically, a second compensating unit composed of four saddle-shaped coils disposed cylindrically pair by pair on both sides of the first compensating unit, and a third compensating unit composed of four saddle-shaped coils piled and disposed concentrically on each of said saddle-shaped coils of said first compensating unit.
Claim 3
Dependent Claim
22 words
A magnetic field compensating apparatus according to claim 1, wherein the coil in each of said compensating units is a superconductive coil.
Claim 4
Dependent Claim
23 words
A magnetic field compensating apparatus according to claim 1, wherein the coil in each of said compensating units is an ordinary conductive coil.
Claim 5
Dependent Claim
190 words
A magnetic field compensating apparatus for compensating error magnetic fields in the radial direction of a magnet apparatus used for a magnetic resonance apparatus comprising: a plurality of compensating units comprising a plurality of serial coils each of which is disposed concentrically along a main magnetic field and symmetrically with regard to a plane perpendicular to said main magnetic field, a plurality of power sources which separately supply currents to these compensating units, and made in such a manner that a plurality of components among said error magnetic fields in the radial direction are contained in each of said compensating units, a plurality of said components are compensated by the whole of a plurality of said compensating units, and, at the same time, each of said currents supplied to said compensating units is decided in accordance with a constitution of each of said compensating units, said plurality of said compensating units comprising a first compensating unit composed of four saddle-shaped coils disposed cylindrically and second and third compensating units each of which is composed of four saddle-shaped coils disposed cylindrically pair by pair on both sides of the compensating unit.
Claim 6
Dependent Claim
190 words
A magnetic field compensating apparatus for compensating error magnetic fields in the radial direction of a magnet apparatus used for a magnetic resonance apparatus comprising: a plurality of compensating units comprising a plurality of serial coils each of which is disposed concentrically along a main magnetic field and symmetrically with regard to a plane perpendicular to said main magnetic field, a plurality of power sources which separately supply currents to these compensating units, and made in such a manner that a plurality of components among said error magnetic fields in the radial direction are contained in each of said compensating units, a plurality of said components are compensated by the whole of a plurality of said compensating units, and, at the same time, each of said currents supplied to said compensating units is decided in accordance with a constitution of each of said compensating units, said plurality of said compensating units comprising a first compensating unit composed of four saddle-shaped coils disposed cylindrically and second and third compensating units each of which is composed of four saddle-shaped coils disposed cylindrically pair by pair on both sides of the compensating unit.
Claim 7
Dependent Claim
22 words
A magnetic field compensating apparatus according to claim 4, wherein the coil in each of said compensating units is a superconductive coil.
Claim 8
Dependent Claim
23 words
A magnetic field compensating apparatus according to claim 4, wherein the coil in each of said compensating units is an ordinary conductive coil.
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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) | 1993-07-30 | 1994-01-29 | 1994-07-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-07-30 | 1998-01-29 | 1998-07-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-07-30 | 2002-01-29 | 2002-07-31 | $7700.00 | Window Closed / Lapsed |