US3820104A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and system for detecting an object within a magnetic field interrogation zone
Assignee: STOP LOSS Inc
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Filing: 1972-12-15
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Granted: 1974-06-25
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Expires: 1992-12-15
Abstract
Abstract This specification discloses a marker for being secured to an object to enable the detection of the object within an interrogation zone having a magnetic field periodically varying at a predetermined fundamental frequency. The marker includes a first elongated ferromagnetic element for being secured to the object. The first ferromagnetic element has a relatively low coercivity and is operable to generate a detectable signal containing harmonics of the fundamental frequency when placed in the interrogation zone. The marker further includes a second ferromagnetic element disposed adjacent to the first element and having a coercivity greater than the first element. Deactivation structure is provided to selectively magnetize the second ferromagnetic element to impose a plurality of pairs of alternate magnetic poles on the first element in order to deactivate the marker. The deactivated marker does not generate a detectable signal containing the desired harmonics when the object passes through the interrogation zone. In the preferred embodiment of the invention, the second ferromagnetic element is constructed so as to be magnetized by a predetermined magnetic field oriented in any direction to deactivate the marker. Also in the preferred embodiment, deactivation structure is provided which checks to insure that the marker has been deactivated prior to allowing the energization of an auxiliary device such as a cash register or the like.
Inventors
- 👤 E Fearon
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 08:13
CPC Classifications
G; G08; G08B; G08B13/00; G08B13/22; G08B13/24; G08B13/2402; G08B13/2405; G08B13/2408; G08B13/2428; G08B13/2431; G08B13/2437; G08B13/2465; G08B13/2468; G08B13/2474; G08B13/2477
Claims Analysis
Total Claims: 35
Claim 1
Independent Claim
124 words
A marker for being secured to an object to enable detection of the presence, identity of status of the object within an interrogation zone having a magnetic field periodically varying at a predetermined fundamental frequency, said marker comprising: a first elongated ferromagnetic element for being secured to said object and having low coercivity capable of generating a detectable signal containing harmonics of said fundamental frequency when placed in said zone, a secons ferromagnetic means disposed adjacent said first element and having a coercivity greater than said first element, said second ferromagnetic means including structure for imposing a plurality of pairs of alternate magnetic poles on said first element when placed in a predetermined magnetic field to thereby prevent the generation of said detectable signal.
Claim 2
Dependent Claim
124 words
A marker for being secured to an object to enable detection of the presence, identity of status of the object within an interrogation zone having a magnetic field periodically varying at a predetermined fundamental frequency, said marker comprising: a first elongated ferromagnetic element for being secured to said object and having low coercivity capable of generating a detectable signal containing harmonics of said fundamental frequency when placed in said zone, a secons ferromagnetic means disposed adjacent said first element and having a coercivity greater than said first element, said second ferromagnetic means including structure for imposing a plurality of pairs of alternate magnetic poles on said first element when placed in a predetermined magnetic field to thereby prevent the generation of said detectable signal.
Claim 3
Dependent Claim
24 words
The marker of claim 1 wherein said second ferromagnetic means comprises an elongated strip of ferromagnetic material having a plurality of apertures formed therethrough.
Claim 4
Dependent Claim
19 words
The marker of claim 2 wherein said apertures comprise circular cutout portions spaced along the length of said strip.
Claim 5
Dependent Claim
38 words
The marker of claim 1 and further comprising means for enabling said second ferromagnetic means to be oriented at any angle to said predetermined magnetic field to impose said plurality of alternate magnetic poles on said first element.
Claim 6
Dependent Claim
27 words
The marker of claim 4 wherein said second ferromagnetic means comprises discrete ferromagnetic elements laterally offset from one another and spaced apart along said elongated first element.
Claim 7
Dependent Claim
37 words
The marker of claim 5 wherein said discrete elements comprise rectangles having widths twice as wide as the width of said first element, said discrete elements positioned to extend on alternate opposite sides of said first element.
Claim 8
Dependent Claim
138 words
A deactivatable marker for being secured to an object to enable detection of the object when the object is placed in an interrogation zone having a magnetic field periodically varying at a predetermined fundamental frequency, said marker comprising: a first elongated ferromagnetic element of low coercivity capable of responding to said magnetic field to generate signals containing harmonics of said fundamental frequency, and second ferromagnetic means disposed adjacent said first element and having a coercivity greater than said first element, said second ferromagnetic means operable to be magnetized by a predetermined magnetic field oriented at any direction relative to said first element for imposing a plurality of pairs of alternate magnetic poles on said first element in order to substantially alter the harmonic content of the signal produced by said first ferromagnetic element when in the interrogation zone.
Claim 9
Dependent Claim
138 words
A deactivatable marker for being secured to an object to enable detection of the object when the object is placed in an interrogation zone having a magnetic field periodically varying at a predetermined fundamental frequency, said marker comprising: a first elongated ferromagnetic element of low coercivity capable of responding to said magnetic field to generate signals containing harmonics of said fundamental frequency, and second ferromagnetic means disposed adjacent said first element and having a coercivity greater than said first element, said second ferromagnetic means operable to be magnetized by a predetermined magnetic field oriented at any direction relative to said first element for imposing a plurality of pairs of alternate magnetic poles on said first element in order to substantially alter the harmonic content of the signal produced by said first ferromagnetic element when in the interrogation zone.
Claim 10
Dependent Claim
27 words
The deactivatable marker of claim 7 wherein said second ferromagnetic means comprises a plurality of discrete ferromagnetic elements spaced along the length of said first elongated element.
Claim 11
Dependent Claim
44 words
The deactivatable marker of claim 8 wherein said discrete elements are laterally offset from said first elements such that a plurality of alternate magnetic poles are imposed upon said first element regardless of the orientation of said predetermined magnetic field to said discrete elements.
Claim 12
Dependent Claim
37 words
The deactivatable marker of claim 9 wherein said discrete elements are rectangular with widths equal to twice the width of said first eLement, alternate ones of said discrete elements extending from opposite sides of said first element.
Claim 13
Dependent Claim
142 words
A deactivatable marker for being secured to an object to enable detection of the object when the object is placed in an interrogation zone having a magnetic field therein, said marker comprising: first and second elongated paper strips, a first elongated ferromagnetic strip having a reduced width but the same length as said paper strips and mounted between said paper strips, said first strip operable to respond to said magnetic field to generate signals containing harmonics of the frequency of said magnetic field, a second elongated ferromagnetic strip having substantially the same width and length as said paper strips and mounted between one of said paper strips and said first ferromagnetic strip, and said second ferromagnetic strip having a greater coercivity than said first ferromagnetic strip and including discrete apertures formed therethrough and spaced along the length of said second ferromagnetic strip.
Claim 14
Dependent Claim
142 words
A deactivatable marker for being secured to an object to enable detection of the object when the object is placed in an interrogation zone having a magnetic field therein, said marker comprising: first and second elongated paper strips, a first elongated ferromagnetic strip having a reduced width but the same length as said paper strips and mounted between said paper strips, said first strip operable to respond to said magnetic field to generate signals containing harmonics of the frequency of said magnetic field, a second elongated ferromagnetic strip having substantially the same width and length as said paper strips and mounted between one of said paper strips and said first ferromagnetic strip, and said second ferromagnetic strip having a greater coercivity than said first ferromagnetic strip and including discrete apertures formed therethrough and spaced along the length of said second ferromagnetic strip.
Claim 15
Dependent Claim
152 words
A deactivatable marker for being secured to an object to enable detection of the object when the object is placed in an interrogation zone having a magnetic field therein, said marker comprising: first and second elongated paper strips, a first elongated ferromagnetic strip having a reduced width but the same length as said paper strips and mounted between said paper strips, said first strip operable to respond to said magnetic field to generate signals containing harmonics of the frequency of said magnetic field, a plurality of rectangular discrete ferromagnetic elements having greater coercivity than said first ferromagnetic strip and mounted between one of said paper strips and said first ferromagnetic strip, said discrete elements having widths equal to twice the width of said first ferromagnetic strip and said discrete elements mounted along said first ferromagnetic strip such that approximately half of such discrete element extends laterally out from said first ferromagnetic element.
Claim 16
Dependent Claim
152 words
A deactivatable marker for being secured to an object to enable detection of the object when the object is placed in an interrogation zone having a magnetic field therein, said marker comprising: first and second elongated paper strips, a first elongated ferromagnetic strip having a reduced width but the same length as said paper strips and mounted between said paper strips, said first strip operable to respond to said magnetic field to generate signals containing harmonics of the frequency of said magnetic field, a plurality of rectangular discrete ferromagnetic elements having greater coercivity than said first ferromagnetic strip and mounted between one of said paper strips and said first ferromagnetic strip, said discrete elements having widths equal to twice the width of said first ferromagnetic strip and said discrete elements mounted along said first ferromagnetic strip such that approximately half of such discrete element extends laterally out from said first ferromagnetic element.
Claim 17
Independent Claim
202 words
A system for detecting a characteristic of an object when said object is in an interrogation zone having a magnetic field periodically varying at a predetermined fundamental frequency, said system comprising: marker means for being secured to the object comprising a first elongated ferromagnetic element of low coercivity capable of generating a detectable signal containing harmonics of said fundamental frequency when placed in said zone, and second ferromagnetic means disposed adjacent said first element and having a coercivity greater than said first element, said second means when magnetized capable of imposing a plurality of pairs of alternate magnetic poles on said first element to alter the harmonic content of the detectable signal produced by said first element when in said interrogation zone, deactivation means for selectively magnetizing said second ferromagnetic means, radiating means for producing within said interrogation zone said magnetic field, receiving means for detecting the harmonic content of the signal produced by said first element, and security readout means coupled to said receiving means responsive to said signal to indicate said characteristic of said object when said second ferromagnetic means is not magnetized, said security readout means providing no indication of said characteristic when said second ferromagnetic means is magnetized.
Claim 18
Independent Claim
202 words
A system for detecting a characteristic of an object when said object is in an interrogation zone having a magnetic field periodically varying at a predetermined fundamental frequency, said system comprising: marker means for being secured to the object comprising a first elongated ferromagnetic element of low coercivity capable of generating a detectable signal containing harmonics of said fundamental frequency when placed in said zone, and second ferromagnetic means disposed adjacent said first element and having a coercivity greater than said first element, said second means when magnetized capable of imposing a plurality of pairs of alternate magnetic poles on said first element to alter the harmonic content of the detectable signal produced by said first element when in said interrogation zone, deactivation means for selectively magnetizing said second ferromagnetic means, radiating means for producing within said interrogation zone said magnetic field, receiving means for detecting the harmonic content of the signal produced by said first element, and security readout means coupled to said receiving means responsive to said signal to indicate said characteristic of said object when said second ferromagnetic means is not magnetized, said security readout means providing no indication of said characteristic when said second ferromagnetic means is magnetized.
Claim 19
Dependent Claim
24 words
The system of claim 13 wherein said second ferromagnetic means comprises an elongated strip of ferromagnetic material having a plurality of apertures formed therethrough.
Claim 20
Dependent Claim
37 words
The system of claim 13 wherein said second ferromagnetic means may be oriented at any angle to said deactivation means for being magnetized to impose a plurality of pairs of alternate magnetic poles of said first element.
Claim 21
Dependent Claim
27 words
The system of claim 13 wherein said second ferromagnetic means comprises discrete ferromagnetic elements laterally offset from one another and spaced apart along said elongated first element.
Claim 22
Independent Claim
88 words
A system for detecting and deactivating a marker secured to an object comprising: marker means comprising first and second ferromagnetic elements having different coercivities, said first element operable to generate harmonic signals when placed in an interrogation zone and said second element operable when magnetized to alter the generation of said harmonic signals, means for detecting the presence of said first element, means operable in response to said detecting means for magnetizing said second element, and means for generating a signal when said second element has been magnetized.
Claim 23
Independent Claim
88 words
A system for detecting and deactivating a marker secured to an object comprising: marker means comprising first and second ferromagnetic elements having different coercivities, said first element operable to generate harmonic signals when placed in an interrogation zone and said second element operable when magnetized to alter the generation of said harmonic signals, means for detecting the presence of said first element, means operable in response to said detecting means for magnetizing said second element, and means for generating a signal when said second element has been magnetized.
Claim 24
Dependent Claim
30 words
The system of claim 17 wherein said means comprises a coil for generating a magnetic field alternating about a fundamental frequency and a pickup coil for receiving said harmonic signals.
Claim 25
Dependent Claim
21 words
The system of claim 18 wherein said magnetizing means comprises a gaussing coil across which a charged capacitor may be discharged.
Claim 26
Dependent Claim
39 words
The system of claim 19 wherein said generating means comprises circuitry for generating an electrical energizing signal after said charged capacitor has been discharged across said gaussing coil and after said pickup coil no longer detects said harmonic signals.
Claim 27
Dependent Claim
16 words
The system of claim 20 and further comprising: auxiliary equipment energized by said electrical energizing signal.
Claim 28
Independent Claim
167 words
A system for detecting an object when said object is in an interrogation zone comprising: means for generating in said interrogation zone a magnetic field periodically varying at a predetermined fundamental frequency, marker means for being secured to said object and including a first elongated ferromagnetic element of low coercivity capable of generating a detectable signal containing harmonics of said fundamental frequency when placed in said interrogation zone, means for detecting said detectable signal to indicate the presence of said object, said marker means further including second ferromagnetic means adjacent said first ferromagnetic element and operable when magnetized to alter the harmonic content of said detectable signal such that said detecting means will not indicate the presence of said object, deactivation means for sensing the presence of said first ferromagnetic element and in response thereto for magnetizing said second ferromagnetic means, and utilization means operable for being energized only when said second ferromagnetic means has been successfully magnetized to alter the harmonic content of said detectable signal.
Claim 29
Independent Claim
167 words
A system for detecting an object when said object is in an interrogation zone comprising: means for generating in said interrogation zone a magnetic field periodically varying at a predetermined fundamental frequency, marker means for being secured to said object and including a first elongated ferromagnetic element of low coercivity capable of generating a detectable signal containing harmonics of said fundamental frequency when placed in said interrogation zone, means for detecting said detectable signal to indicate the presence of said object, said marker means further including second ferromagnetic means adjacent said first ferromagnetic element and operable when magnetized to alter the harmonic content of said detectable signal such that said detecting means will not indicate the presence of said object, deactivation means for sensing the presence of said first ferromagnetic element and in response thereto for magnetizing said second ferromagnetic means, and utilization means operable for being energized only when said second ferromagnetic means has been successfully magnetized to alter the harmonic content of said detectable signal.
Claim 30
Dependent Claim
50 words
The system of claim 22 wherein said deactivation means comprises: means for generating a second magnetic field periodically varying at a predetermined fundamental frequency, second means for detecting said detectable signals, and gaussing means responsive to said second means for generating a magnetic field to magnetize said second ferromagnetic means.
Claim 31
Dependent Claim
30 words
The system of claim 23 wherein said utilization means is energized only after the operation of said gaussing means and when said second means no longer detects said detectable signal.
Claim 32
Dependent Claim
13 words
The system of claim 24 wherein said utilization means comprises a cash register.
Claim 33
Independent Claim
92 words
The method of deactivating a marker having a first ferromagnetic strip operable to generate detectable harmonic signals when placed in an alternating magnetic field and a second ferromagnetic element operable when magnetized to alter the detectable harmonic signal, the method comprising: applying an alternating magnetic field to said marker, sensing said detectable harmonic signals and in response thereto applying a magnetizing field to magnetize said second ferromagnetic element, reapplying said alternating magnetic field to said marker, and in the absence of detection of said detectable harmonic signals, generating an output electrical signal.
Claim 34
Independent Claim
92 words
The method of deactivating a marker having a first ferromagnetic strip operable to generate detectable harmonic signals when placed in an alternating magnetic field and a second ferromagnetic element operable when magnetized to alter the detectable harmonic signal, the method comprising: applying an alternating magnetic field to said marker, sensing said detectable harmonic signals and in response thereto applying a magnetizing field to magnetize said second ferromagnetic element, reapplying said alternating magnetic field to said marker, and in the absence of detection of said detectable harmonic signals, generating an output electrical signal.
Claim 35
Dependent Claim
14 words
The method of claim 26 wherein said output electrical signal unlocks a cash registeR.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-06-24 | 1977-12-24 | 1978-06-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-06-24 | 1981-12-24 | 1982-06-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-06-24 | 1985-12-24 | 1986-06-25 | $7700.00 | Window Closed / Lapsed |