Patent EP0251561A1 successfully refreshed from Google Patents.
EP0251561A1
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Magnetic field generator
Assignee: Canon Inc
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Filing: 1987-06-16
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Granted: —
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Expires: 2007-06-16
Abstract
Abstract A magnetic field generator includes: a first coil group, including at least one coil, for generating a magnetic field upon energization; a second coil group, including at least one coil, and arranged such that a magnetic field is generated in substantially the same space as that of the magnetic field generated by the first coil group, a self-inductance of the second coil group being smaller than that of the first coil group; and a driving means for selectively energizing the first and second coil groups. The driving means energizes the second coil group first, and after the magnetic field is caused to rise by the second coil group, energizes the first coil group, thereby holding a constant magnetic field. A method of driving a magnetic field generator including a first coil group for generating a magnetic field and a second coil group for generating a magnetic field in substantially the same space as that of the magnetic field generated by the first coil group and having a self-inductance smaller than that of the first coil group, includes the steps of: energizing only the second coil group to generate a magnetic field; and energizing the first coil group after the magnetic field generated by the second coil group rises, thereby holding a constant magnetic field.
Inventors
- 👤 Hisatoshi Baba
- 👤 Naoki Imokawa
- 👤 Makoto Shiho
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 14:56
CPC Classifications
H; H01; H01F; H01F7/00; H01F7/06; H01F7/08; H01F7/18; H01F7/1805; H01F7/1827; G; G11; G11B; G11B11/00; G11B11/10; G11B11/105; G11B11/10502; G11B11/10504; G11B11/10508; G11B11/10532; G11B11/10534; G06; G06F; G06F2212/00; G06F2212/20; G06F2212/202; G06F2212/2022
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
118 words
A magnetic field generator comprising: a first coil group, including at least one coil, for generating a magnetic field upon energization; a second coil group, including at least one coil, and arranged such that a magnetic field is generated in substantially the same space as that of the magnetic field generated by said first coil group, a self-inductance of said second coil group being smaller than that of said first coil group; and driving means for selectively energizing said first and second coil groups, said driving means energizing said second coil group first, and after the magnetic field is caused to rise by said second coil group, energizing said first coil group, thereby holding a constant magnetic field.
Claim 2
Dependent Claim
118 words
A magnetic field generator comprising: a first coil group, including at least one coil, for generating a magnetic field upon energization; a second coil group, including at least one coil, and arranged such that a magnetic field is generated in substantially the same space as that of the magnetic field generated by said first coil group, a self-inductance of said second coil group being smaller than that of said first coil group; and driving means for selectively energizing said first and second coil groups, said driving means energizing said second coil group first, and after the magnetic field is caused to rise by said second coil group, energizing said first coil group, thereby holding a constant magnetic field.
Claim 3
Dependent Claim
26 words
A generator according to claim l, wherein said driving means includes a voltage source connected to said first and second coil groups respectively through switching circuits.
Claim 4
Dependent Claim
20 words
A generator according to claim 2, wherein said first and second coil groups are connected to different voltage sources, respectively.
Claim 5
Dependent Claim
25 words
A generator according to claim l, wherein the number of turns of said first coil group is larger than that of said second coil group.
Claim 6
Dependent Claim
43 words
A generator according to claim 4, wherein said coils of said first and second coil groups are wound around a same single yoke such that said coil of said second coil group is located inside of said coil of said first coil group.
Claim 7
Dependent Claim
29 words
A generator according to claim l, wherein the number of turns N of the coil of said second coil group satisfies the following relation: l00 ≦ N ≦ 400
Claim 8
Dependent Claim
28 words
A generator according to claim l, wherein a cross-sectional area of a conductive wire used for the coil of said second coil group is 0.04 (mm²) or more.
Claim 9
Independent Claim
94 words
A method of driving a magnetic field generator including a first coil group for generating a magnetic field and a second coil group for generating a magnetic field in substantially the same space as that of the magnetic field generated by said first coil group and having a self-inductance smaller than that of said first coil group, comprising the steps of: energizing only said second coil group to generate magnetic field; and energizing said first coil group after the magnetic field generated by said second coil group rises, thereby holding a constant magnetic field.
Claim 10
Independent Claim
94 words
A method of driving a magnetic field generator including a first coil group for generating a magnetic field and a second coil group for generating a magnetic field in substantially the same space as that of the magnetic field generated by said first coil group and having a self-inductance smaller than that of said first coil group, comprising the steps of: energizing only said second coil group to generate magnetic field; and energizing said first coil group after the magnetic field generated by said second coil group rises, thereby holding a constant magnetic field.
Claim 11
Dependent Claim
26 words
A method according to claim 8, further comprising the step of: terminating energization of said second coil group after starting energization of said first coil group.
Claim 12
Dependent Claim
26 words
l0. A method according to claim 8, wherein said first coil group is energized in a predetermined time interval after said second coil group is energized.
Claim 13
Dependent Claim
27 words
A method according to claim 8, wherein a voltage applied to energize said second coil group is higher than that applied to energize said first coil group.
Claim 14
Dependent Claim
91 words
A magnetic field generator comprising: a first coil arrangement for producing a magnetic field when energised, a second coil arrangement for producing a magnetic field, when energised, in substantially the same space as the first coil arrangement, the second coil arrangement having a substantially smaller impedance than the first coil arrangement, and means for firstly energising the second coil arrangement to produce the magnetic field and, when the field is established by the second coil arrangement, energising the first coil arrangement and de-energising the second coil arrangement to maintain the field.
Claim 15
Dependent Claim
91 words
A magnetic field generator comprising: a first coil arrangement for producing a magnetic field when energised, a second coil arrangement for producing a magnetic field, when energised, in substantially the same space as the first coil arrangement, the second coil arrangement having a substantially smaller impedance than the first coil arrangement, and means for firstly energising the second coil arrangement to produce the magnetic field and, when the field is established by the second coil arrangement, energising the first coil arrangement and de-energising the second coil arrangement to maintain the field.
References Cited (Backward Citations)
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