US5130697A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for shaping a magnetic field
Assignee: Sensormatic Electronics LLC
•
Filing: 1990-10-30
•
Granted: 1992-07-14
•
Expires: 2010-10-30
Abstract
Abstract An apparatus for use with a magnetic field in which eddy currents are generated and the generated currents are configured to provide a preselected effect to the field.
Inventors
- 👤 Colleen McGinn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 21:00
CPC Classifications
G; G01; G01V; G01V3/00; G01V3/08
Claims Analysis
Total Claims: 92
Claim 1
Independent Claim
86 words
Apparatus for use in shaping a magnetic field in a zone, said apparatus comprising: means for generating eddy currents; means for causing said eddy currents to be of a character to have at least a preselected effect on said field when said apparatus is situated bordering said zone, said preselected effect including reinforcing components and/or weakening selected components of said field, said means for causing including selecting the configuration of said generating means such that eddy currents of said character are generated by said generating means.
Claim 2
Dependent Claim
86 words
Apparatus for use in shaping a magnetic field in a zone, said apparatus comprising: means for generating eddy currents; means for causing said eddy currents to be of a character to have at least a preselected effect on said field when said apparatus is situated bordering said zone, said preselected effect including reinforcing components and/or weakening selected components of said field, said means for causing including selecting the configuration of said generating means such that eddy currents of said character are generated by said generating means.
Claim 3
Dependent Claim
38 words
Apparatus in accordance with claim 1 wherein: said generating means includes a plurality of members and said configuration of said generating means includes the shape of said members and the relationship of said members one to the other.
Claim 4
Dependent Claim
11 words
Apparatus in accordance with claim 2 wherein: said members are conductive.
Claim 5
Dependent Claim
50 words
Apparatus in accordance with claim 3 further comprising: magnetic means situated adjacent said generating means such that when said apparatus is situated bordering said zone said magnetic means is further outward of said zone than said generating means and acts to prevent said field from extending outward of said zone.
Claim 6
Dependent Claim
32 words
Apparatus in accordance with claim 4 wherein: said members comprise one of aluminum, copper, a superconductive material and a material whose conductivity is equal to or greater than about 0.29×10 8 ν/m.
Claim 7
Dependent Claim
14 words
Apparatus in accordance with claim 5 wherein: said magnetic means comprises low carbon steel.
Claim 8
Dependent Claim
26 words
Apparatus in accordance with claim 6 further comprising: front and back members which form a housing in which said generating means and magnetic means are disposed.
Claim 9
Dependent Claim
36 words
Apparatus in accordance with claim 7 wherein: said apparatus is for further use with an antenna which receives said field and which borders said zone adjacent said apparatus when said apparatus is situated bordering said zone.
Claim 10
Dependent Claim
49 words
Apparatus in accordance with claim 3 wherein: said members are further magnetic such that said members, in addition to generating said eddy currents, also provide a low reluctance path which acts to prevent said field from extending outward of said zone when said apparatus is situated bordering said zone.
Claim 11
Dependent Claim
51 words
Apparatus in accordance with claim 9, further comprising: magnetic means situated adjacent said generating means such that when said apparatus is situated bordering said zone said magnetic means is further outward of said zone than said generating means and acts to further prevent said field from extending outward of said zone.
Claim 12
Dependent Claim
19 words
Apparatus in accordance with claim 10 wherein: the conductivity of said members is less than about 0.29×10 8 ν/m.
Claim 13
Dependent Claim
13 words
Apparatus in accordance with claim 11 wherein: said members comprise low carbon steel.
Claim 14
Dependent Claim
20 words
Apparatus in accordance with claim 12 wherein: the carbon content of said steel is between about 8 to 10 percent.
Claim 15
Dependent Claim
20 words
Apparatus in accordance with claim 12 wherein: the carbon content of said steel is between about 2 to 6 percent.
Claim 16
Dependent Claim
11 words
Apparatus in accordance with claim 14 wherein: said steel is Vitrenamel.
Claim 17
Dependent Claim
26 words
Apparatus in accordance with claim 12 further comprising: front and back members which form a housing in which said generating means and magnetic means are disposed.
Claim 18
Dependent Claim
36 words
Apparatus in accordance with claim 16 wherein: the apparatus is for further use with an antenna which transmits said field and which borders said zone adjacent said apparatus when said apparatus is situated bordering said zone.
Claim 19
Dependent Claim
17 words
Apparatus in accordance with claim 2 wherein: said members are one of: conductive; and conductive and magnetic.
Claim 20
Dependent Claim
43 words
Apparatus in accordance with claim 18 wherein: said members are arranged and configured and/or said apparatus includes further means such that when said apparatus in situated adjacent said zone, the eddy current effects on said field from adjacent members do not entirely cancel.
Claim 21
Dependent Claim
24 words
Apparatus in accordance with claim 19 wherein: the areas of adjacent members exposed to said field are of different size to realize said non-cancellation.
Claim 22
Dependent Claim
21 words
Apparatus in accordance with claim 20 wherein: said members are arranged in overlapping relationship to realize such different size exposed areas.
Claim 23
Dependent Claim
29 words
Apparatus in accordance with claim 19 wherein: said further means includes a low conductivity, high permeability material disposed between adjacent edges of said adjacent members to realize said non-cancellation.
Claim 24
Dependent Claim
55 words
Apparatus in accordance with claim 19 wherein: said members are arranged such that edges of said members extend in a given direction, whereby the effect of the eddy currents of said members at said edges on said field includes reinforcement of at least parts of said field in a direction transverse to said given direction.
Claim 25
Dependent Claim
48 words
Apparatus in accordance with claim 23 wherein: said members are arranged such that edges of said members extend horizontally, whereby the effect of the eddy currents of said members at said edges on said field includes reinforcement of at least parts of said field in the vertical direction.
Claim 26
Dependent Claim
57 words
Apparatus in accordance with claim 23 wherein: said members are arranged such that edges of said members extend vertically, whereby the effect of the eddy currents of said members at said edges of said members on said field includes reinforcement of at least parts of said field in at least one of the horizontal and lateral directions.
Claim 27
Dependent Claim
12 words
Apparatus in accordance with claim 1 wherein: said generating means is conductive.
Claim 28
Dependent Claim
104 words
Apparatus in accordance with claim 26 wherein: said apparatus is to be used with an antenna which borders said zone and is adjacent said apparatus when said apparatus is situated bordering said zone; and said antenna is one of: an antenna transmitting said field in response to an electrical signal; an antenna subject to said field which field is generated by another antenna bordering said zone or by a magnetic material in said zone; and an antenna transmitting said field in response to a field generated by another antenna bordering said zone; and said effect includes reinforcement of at least portions of said field.
Claim 29
Dependent Claim
32 words
Apparatus in accordance with claim 27 wherein: said generating means comprises one of copper, aluminum, a superconductive material and a material whose conductivity is equal to or greater than 0.29×10 8 ν/m.
Claim 30
Dependent Claim
38 words
Apparatus in accordance with claim 27 wherein: said generating means includes a plurality of members and said configuration of said generating means includes the shape of said members and the relationship of said members one to the other.
Claim 31
Dependent Claim
43 words
Apparatus in accordance with claim 29 wherein: said members are arranged and configured and/or said apparatus includes further means such that when said apparatus is situated adjacent said zone, the eddy current effects on said field from adjacent members do not entirely cancel.
Claim 32
Dependent Claim
55 words
Apparatus in accordance with claim 30 wherein: said members are arranged such that edges of said members extend in a given direction, whereby the effect of the eddy currents of said members at said edges on said field includes reinforcement of at least parts of said field in a direction transverse to said given direction.
Claim 33
Dependent Claim
32 words
Apparatus in accordance with claim 31 wherein: said generating means comprises one of copper, aluminum, a superconductive material and a material whose conductivity is equal to or greater than 0.29×10 8 ν/m.
Claim 34
Dependent Claim
50 words
Apparatus in accordance with claim 32 further comprising: magnetic means situated adjacent said generating means such that when said apparatus is situated bordering said zone said magnetic means is further outward of said zone than said generating means and acts to prevent said field from extending outward of said zone.
Claim 35
Dependent Claim
79 words
Apparatus in accordance with claim 27 wherein: said antenna is an antenna transmitting said field; said effect includes subtracting from strongest portions of said field while tending to preserve the weakest portions of said field; and said generating means is further magnetic such that, in addition to generating said eddy currents, said generating means provides a low reluctance path which acts to prevent said field from extending outward of said zone when said apparatus is situated adjacent said zone.
Claim 36
Dependent Claim
38 words
Apparatus in accordance with claim 34 wherein: said generating means includes a plurality of members and said configuration of said generating means includes the shape of said members and the relationship of said members one to the other.
Claim 37
Dependent Claim
43 words
Apparatus in accordance with claim 35 wherein: said members are arranged and configured and/or said apparatus includes further means such that when said apparatus in situated adjacent said zone, the eddy current effects on said field from adjacent members do not entirely cancel.
Claim 38
Dependent Claim
55 words
Apparatus in accordance with claim 36 wherein: said members are arranged such that edges of said members extend in a given direction, whereby the effect of the eddy currents of said members at said edges on said field includes reinforcement of at least parts of said field in a direction transverse to said given direction.
Claim 39
Dependent Claim
20 words
Apparatus in accordance with claim 37 wherein: the conductivity of said generating means is less than about 0.29×10 8 ν/m.
Claim 40
Dependent Claim
14 words
Apparatus i accordance with claim 38 wherein: said generating means comprises low carbon steel.
Claim 41
Dependent Claim
20 words
Apparatus i accordance with claim 39 wherein: the carbon content of said steel is between about 8 to 10 percent.
Claim 42
Dependent Claim
20 words
Apparatus in accordance with claim 39 wherein: the carbon content of said steel is between about 2 to 6 percent.
Claim 43
Dependent Claim
11 words
Apparatus in accordance with claim 41 wherein: said steel is Vitrenamel.
Claim 44
Dependent Claim
51 words
Apparatus in accordance with claim 26 wherein: said generating means is further magnetic such that, in addition to generating said eddy currents, said generating means also provides a low reluctance path which acts to prevent said field from extending outward of said zone when said apparatus is situated adjacent said zone.
Claim 45
Dependent Claim
75 words
Apparatus in accordance with claim 43 wherein: said generating means includes a plurality of members and said configuration of said generating means includes the shape of said members and the relationship of said members one to the other, said members being arranged and configured and/or said apparatus further including further means such that when said apparatus is situated adjacent said zone, the eddy current effects on said field from adjacent members do not entirely cancel.
Claim 46
Dependent Claim
55 words
Apparatus in accordance with claim 44 wherein: said members are arranged such that edges of said members extend in a given direction, whereby the effect of the eddy currents of said members at said edges on said field includes reinforcement of at least parts of said field in a direction transverse to said given direction.
Claim 47
Dependent Claim
20 words
Apparatus in accordance with claim 45 wherein: the conductivity of said generating means is less than about 0.29×10 8 ν/m.
Claim 48
Dependent Claim
14 words
Apparatus in accordance with claim 46 wherein: said generating means comprises low carbon steel.
Claim 49
Independent Claim
92 words
A method for use in shaping a magnetic field in a zone, said method comprising: generating eddy currents with a generating means; causing said eddy currents to be of a character to have at least a preselected effect on said field when said generating means is situated bordering said zone, said preselected effect including reinforcing components and/or weakening selected components of said field, said step of causing including selecting the configuration of the generating means generating the eddy currents such that eddy currents of said character are generated by said generating means.
Claim 50
Independent Claim
92 words
A method for use in shaping a magnetic field in a zone, said method comprising: generating eddy currents with a generating means; causing said eddy currents to be of a character to have at least a preselected effect on said field when said generating means is situated bordering said zone, said preselected effect including reinforcing components and/or weakening selected components of said field, said step of causing including selecting the configuration of the generating means generating the eddy currents such that eddy currents of said character are generated by said generating means.
Claim 51
Dependent Claim
40 words
A method in accordance with claim 48 wherein: said step of selecting includes forming said generating means from a plurality of members and further selecting the shape of said members and the relationship of said members one to the other.
Claim 52
Dependent Claim
12 words
A method in accordance with claim 49 wherein: said members are conductive.
Claim 53
Dependent Claim
18 words
A method in accordance with claim 49 wherein: said members are one of: conductive; and conductive and magnetic.
Claim 54
Dependent Claim
57 words
A method in accordance with claim 51 wherein: said step of further selecting includes arranging and shaping said members and/or incorporating a further means with said members in forming said generating means such that when said generating means is situated adjacent said zone, the eddy current effects on said field from adjacent members do not entirely cancel.
Claim 55
Dependent Claim
28 words
A method in accordance with claim 52 wherein: the areas of adjacent members exposed to said field are selected to be of different size to realize said non-cancellation.
Claim 56
Dependent Claim
19 words
A method in accordance with claim 53 wherein: said members are arranged in overlapping relationship to realize said non-cancellation.
Claim 57
Dependent Claim
24 words
A method in accordance with claim 52 wherein: low-conductivity, high-permeability material is disposed between adjacent edges of said adjacent members to realize said non-cancellation.
Claim 58
Dependent Claim
56 words
A method in accordance with claim 52 wherein: said members are arranged such that edges of said members extend in a given direction, whereby the effect of the eddy currents of said members at said edges on said field includes reinforcement of at least parts of said field in a direction transverse to said given direction.
Claim 59
Dependent Claim
49 words
A method in accordance with claim 56 wherein: said members are arranged such that edges of said members extend horizontally, whereby the effect of the eddy currents of said members at said edges on said field includes reinforcement of at least parts of said field in the vertical direction.
Claim 60
Dependent Claim
55 words
A method in accordance with claim 56 wherein: said members are arranged such that edges of said members extend vertically, whereby the effect of the eddy currents of said members at said edges on said field includes reinforcement of at least parts of said field in at least one of the horizontal and lateral directions.
Claim 61
Dependent Claim
13 words
A method in accordance with claim 48 wherein: said generating means is conductive.
Claim 62
Dependent Claim
111 words
A method in accordance with claim 59 wherein: said eddy currents are to be used with an antenna which borders said zone and is adjacent said eddy currents when said generating means generating said eddy currents is situated bordering said zone; and said antenna is one of: an antenna transmitting said field in response to an electrical signal; an antenna subject to said field which is generated by another antenna bordering said zone or by a magnetic material in said zone; and an antenna transmitting said field in response to a field generated by another antenna bordering said zone; and said effect includes reinforcement of at least portions of said field.
Claim 63
Dependent Claim
82 words
A method in accordance with claim 60 wherein: said antenna is an antenna transmitting said field; said effect includes subtracting from the strongest portions of said field while tending to preserve the weakest portions of said field; and said generating means is further magnetic such that, in addition to generating said eddy currents, said generating provides a low reluctance path means which acts to inhibit said field from extending outward of said zone when said generating means is situated adjacent said zone.
Claim 64
Dependent Claim
40 words
A method in accordance with claim 61 wherein: said step of selecting includes forming said generating means from a plurality of members and further selecting the shape of said members and the relationship of said members one to the other.
Claim 65
Dependent Claim
57 words
A method in accordance with claim 62 wherein: said step of further selecting includes arranging and shaping said members and/or incorporating a further means with said members in forming said generating means such that when said generating means is situated adjacent said zone, the eddy current effects on said field from adjacent members do not entirely cancel.
Claim 66
Dependent Claim
56 words
A method in accordance with claim 63 wherein: said members are arranged such that edges of said members extend in a given direction, whereby the effect of the eddy currents of said members at said edges on said field includes reinforcement of at least parts of said field in a direction transverse to said given direction.
Claim 67
Dependent Claim
21 words
A method in accordance with claim 64 wherein: the conductivity of said generating means is less than about 0.29×10 8 ν/m.
Claim 68
Dependent Claim
15 words
A method in accordance with claim 65 wherein: said generating means comprises low carbon steel.
Claim 69
Dependent Claim
21 words
A method in accordance with claim 66 wherein: the carbon content of said steel is between about 8 to 10 percent.
Claim 70
Dependent Claim
21 words
A method in accordance with claim 66 wherein: the carbon content of said steel is between about 2 to 6 percent.
Claim 71
Dependent Claim
12 words
A method in accordance with claim 68 wherein: said steel is Vitrenamel.
Claim 72
Dependent Claim
33 words
A method in accordance with claim 60 wherein: said generating means comprises one of copper, aluminum, a superconductive material and a material whose conductivity is equal to or greater than 0.29×10 8 ν/m.
Claim 73
Dependent Claim
43 words
A method in accordance with claim 70 further comprising: situating magnetic means adjacent said generating means such that said magnetic means is further outward of said zone than said generating means and acts to prevent said field from extending outward of said zone.
Claim 74
Dependent Claim
40 words
A method in accordance with claim 60 wherein: said step of selecting includes forming said generating means from a plurality of members and further selecting the shape of said members and the relationship of said members one to the other.
Claim 75
Dependent Claim
57 words
A method in accordance with claim 72 wherein: said step of further selecting includes arranging and shaping said members and/or incorporating a further means with said members in forming said generating means such that when said generating means is situated adjacent said zone, the eddy current effects on said field from adjacent members do not entirely cancel.
Claim 76
Dependent Claim
56 words
A method in accordance with claim 73 wherein: said members are arranged such that edges of said members extend in a given direction, whereby the effect of the eddy currents of said members at said edges on said field includes reinforcement of at least parts of said field in a direction transverse to said given direction.
Claim 77
Dependent Claim
33 words
A method in accordance with claim 74 wherein: said generating means comprises one of copper, aluminum, a superconductive material and a material whose conductivity is equal to or greater than 0.29×10 8 ν/m.
Claim 78
Dependent Claim
51 words
A method in accordance with claim 59 wherein: said generating means is further magnetic such that, in addition to generating said eddy currents, said generating means provides a low reluctance path which acts to prevent said field from extending outward of said zone when said apparatus is situated adjacent said zone.
Claim 79
Dependent Claim
21 words
A method in accordance with claim 76 wherein: the conductivity of said generating means is less than about 0.29×10 8 ν/m.
Claim 80
Dependent Claim
15 words
A method in accordance with claim 77 wherein: said generating means comprises low carbon steel.
Claim 81
Dependent Claim
134 words
An article surveillance system in which articles containing magnetic markers are to be detected passing through a surveillance zone, comprising: means for transmitting a magnetic field into said zone, said transmitting means including a transmitter antenna; receiving means responsive to the magnetic field in said zone, said receiving means including a receiver antenna; and apparatus for controlling and shaping the magnetic field in said zone comprising: means for generating eddy currents; and means for causing said eddy currents to be of a character to have at least a preselected effect on the field in said zone, said preselected effect including reinforcing components and/or weakening selected components of said field, said means for causing including selecting the configuration of said generating means such that eddy currents of said character are generated by said generating means.
Claim 82
Dependent Claim
134 words
An article surveillance system in which articles containing magnetic markers are to be detected passing through a surveillance zone, comprising: means for transmitting a magnetic field into said zone, said transmitting means including a transmitter antenna; receiving means responsive to the magnetic field in said zone, said receiving means including a receiver antenna; and apparatus for controlling and shaping the magnetic field in said zone comprising: means for generating eddy currents; and means for causing said eddy currents to be of a character to have at least a preselected effect on the field in said zone, said preselected effect including reinforcing components and/or weakening selected components of said field, said means for causing including selecting the configuration of said generating means such that eddy currents of said character are generated by said generating means.
Claim 83
Dependent Claim
19 words
A system in accordance with claim 79 wherein: said apparatus is adjacent one of said transmitter and receiver antennas.
Claim 84
Dependent Claim
39 words
A system in accordance with claim 79 wherein: said generating means includes a plurality of members and said configuration of said generating means includes the shape of said members and the relationship of said members one to the other.
Claim 85
Dependent Claim
18 words
A system in accordance with claim 81 wherein: said members are one of: conductive; and conductive and magnetic.
Claim 86
Dependent Claim
54 words
A system in accordance with claim 82 wherein: said apparatus further comprises: magnetic means situated adjacent said generating means such that when said apparatus is situated bordering said zone said magnetic means is further outward of said zone than said generating means and acts to prevent said field from extending outward of said zone.
Claim 87
Independent Claim
119 words
A method of detecting articles containing magnetic markers passing through a surveillance zone, comprising: transmitting with a transmitter antenna a magnetic field into said zone; receiving with a receiving antenna the magnetic field in said zone; and controlling and shaping the magnetic field in said zone comprising: generating eddy currents with a generating means, and causing said eddy currents to be of a character to have at least a preselected effect on the field in said zone, said preselected effect including reinforcing components and/or weakening selected components of said field, said step of causing including selecting the configuration of the generating means generating the eddy currents such that eddy currents of said character are generated by said generating means.
Claim 88
Independent Claim
119 words
A method of detecting articles containing magnetic markers passing through a surveillance zone, comprising: transmitting with a transmitter antenna a magnetic field into said zone; receiving with a receiving antenna the magnetic field in said zone; and controlling and shaping the magnetic field in said zone comprising: generating eddy currents with a generating means, and causing said eddy currents to be of a character to have at least a preselected effect on the field in said zone, said preselected effect including reinforcing components and/or weakening selected components of said field, said step of causing including selecting the configuration of the generating means generating the eddy currents such that eddy currents of said character are generated by said generating means.
Claim 89
Dependent Claim
30 words
A method in accordance with claim 84 wherein: said shaping and controlling of said field is carried out with said generating means adjacent one of said transmitter and receiver antennas.
Claim 90
Dependent Claim
42 words
A method in accordance with claim 85 wherein: said generating means includes a plurality of members and said selecting the configuration of said apparatus includes further selecting the shape of said members and the relationship of said members one to the other.
Claim 91
Dependent Claim
18 words
A method in accordance with claim 86 wherein; said members are one of: conductive; and conductive and magnetic.
Claim 92
Dependent Claim
43 words
A method in accordance with claim 87 further comprising: situating magnetic means adjacent said generating means such that said magnetic means is further outward of said zone than said generating means and acts to prevent said field from extending outward of said zone.
References Cited (Backward Citations)
US4769631A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-07-14 | 1996-01-13 | 1996-07-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-07-14 | 2000-01-13 | 2000-07-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-07-14 | 2004-01-13 | 2004-07-14 | $7700.00 | Window Closed / Lapsed |