| Patent Number |
Title Of Patent |
Date Issued |
| RE29610 |
Field strength uniformity control system |
April 11, 1978 |
| An electromagnetic interrogation field in a theft detection system is made effectively more uniform by energizing different antenna windings lying in different planes at the same frequency but at different phases so that the resulting field pattern rotates in the vicinity of the antenna |
| 5401584 |
Surveillance marker and method of making same |
March 28, 1995 |
| A deactivatable electronic theft detection marker is made from a strip or ribbon of high magnetic permeability strip or ribbon and then high magnetic coercivity material is deposited on the strip or ribbon by electroplating. |
| 5304983 |
Multiple pulse responder and detection system and method of making and using same |
April 19, 1994 |
| A responder for electronic article surveillance apparatus is made by subjecting a plurality of magnetizable elements to heating in the presence of a magnetic field and maintaining the field at a different intensity for each element as it is cooled to provide different magnetic characteri |
| 5264829 |
Method and apparatus for theft detection using digital signal processing |
November 23, 1993 |
| Signals received by an electronic article surveillance system are processed digitally to ascertain the variation in magnitude of successive signals and to prevent the actuation of an alarm when the variation exceeds a predetermined amount; and signals whose frequency components have been |
| 5225807 |
Method and apparatus for sensitizing and desensitizing targets for electronic article surveillan |
July 6, 1993 |
| Magnetically desensitized targets or sensor elements on protected articles are resensitized by means of rotating permanent magnets which are moved relative to the magnetized target desensitizer elements such that the elements become subjected to reversing magnetic fields of gradually |
| 5206626 |
Stabilized article surveillance responder |
April 27, 1993 |
| An electronic article surveillance system responder which comprises an electrical responder circuit and a housing which mounts the circuit on an article to be protected. The housing is arranged to support the circuit in such a manner that a dielectric region is formed between the circuit |
| 5146204 |
Theft detection apparatus and flattened wire target and method of making same |
September 8, 1992 |
| Items of merchandise (30) are protected from shoplifting or theft by affixing to them special responder targets (32), which are formed by drawing a material of high magnetic permeability into a thin wire and thereafter rolling the wire into a flattened strip and annealing the strip a |
| 5126720 |
Method and apparatus for deactivating magnetic targets |
June 30, 1992 |
| Articles of merchandise (42) which contain deactivatable theft detection targets (44) have their targets deactivated by passing them through a box-like apparatus (30) made of low coercive force, high saturation induction material with a multiplicity of permament magnets (48) on its i |
| 5121103 |
Load isolated article surveillance system and antenna assembly |
June 9, 1992 |
| An electronic theft detection system with a transmitter antenna assembly which includes a flat electrically conductive panel positioned close to a transmitter loop antenna to preload it and isolate it from the loading effects of nearby metal objects and a receiver arranged with a signal |
| 5088165 |
Theft deterrent fastener and fastener assembly |
February 18, 1992 |
| A fastener and fastener assembly characterized by a pin with an expansive molded plastic head of concave configuration and a frangible membrane sealed to the head to enclose a hollow space for containing an undesirable fluid such as a dye, so that when prying forces are applied to bend t |
| 5029291 |
Electromagnetic sensor element and methods and apparatus for making and using same |
July 2, 1991 |
| A novel sensor element having low magnetic coercivity and an asymmetric hysteresis characteristic is formed by heating a strip of cobalt alloy in an exidizing atmosphere to form an oxide coating thereon and then the strip is cooled in the presence of a magnetic field of about 0.3 oersted |
| 4987754 |
Magnetically releasable target lock |
January 29, 1991 |
| A magnetically releasable pin lock which comprises catch elements mounted to pivot about axes perpendicular to and displaced from the pin axis and elongated magnetizable actuation elements which extend from the catch elements along the pin axis to be acted upon by applied magnetic de |
| 4870391 |
Multiple frequency theft detection system |
September 26, 1989 |
| A swept frequency theft detection system for detecting different resonant circuit targets which are resonant at different frequencies. The system comprises arrangements to generate swept frequency transmitter signals centered at different frequencies but which are swept in synchronism. A |
| 4751500 |
Detection of unauthorized removal of theft detection target devices |
June 14, 1988 |
| An article surveillance system includes a first monitor 26 at a store exit way 12 and second monitors 34 in the dressing rooms 20 and rest rooms 22 in the store to detect security tags 24 attached to articles of merchandise 14. When the tags 24 are attached to the merchandise they hold |
| 4684930 |
Method and apparatus for deactivating targets used in electromagnetic type article surveillance |
August 4, 1987 |
| A deactivator for deactivating targets used in electromagnetic article surveillance systems comprises a solid element with a convexly curved outer surface, e.g., a cylinder and a plurality of permanent magnets which form a patter of variously directed magnetic fields is a plane adjacent |
| 4665387 |
Method and apparatus for target deactivation and reactivation in article surveillance systems |
May 12, 1987 |
| Targets (14) mounted on objects (12) for detection by a magnetic type theft detection system are deactivated in a target deactivator (26,64) which has magnet assembly (40,72) made up of spaced apart magnets with alternately opposed poles extending in a plane and guide walls (36, 38, 68, |
| 4642613 |
Electronic theft detection apparatus with responder elements on protected articles |
February 10, 1987 |
| A self contained electronic theft detection apparatus comprising a housing (30) from which a rigid tubular transmitter antenna loop (32) extends; and a wire loop receiver antenna (56) extends inside the transmitter antenna loop. The transmitter antenna (32) is provided with a capacitor ( |
| 4623877 |
Method and apparatus for detection of targets in an interrogation zone |
November 18, 1986 |
| Targets (30) of readily saturable mangetic material and mounted on protected articles (14) are detected when taken through an interrogation zone (24) in which an alternating magnetic interrogation field is generated by transmitter antenna coils (42, 44). The target (30) is driven alt |
| 4590461 |
Tamper resistant target wafer and fastener assembly |
May 20, 1986 |
| A tamper-resistant target wafer (10) for use in an electronic theft detection system has a housing formed with bulges (16 and 22) aligned with each other on opposite sides and which slope continuously downward toward the plane of the target wafer to minimize fulcrum leverage to a prying |
| 4568921 |
Theft detection apparatus and target and method of making same |
February 4, 1986 |
| Items of merchandise (30) are protected from shoplifting or theft by affixing to them, special responder targets (32), which are formed by drawing a material of high magnetic permeability into a thin wire, then heat treating the wire to substantially increase its magnetic permeability |
| 4531264 |
Theft detection system target fastener |
July 30, 1985 |
| A fastening assembly for fastening a wafer (10) to an article of merchandise (12) and comprising a locking mechanism in a housing (14) and a fastener element (16) having an expansive head (18) and a shank (20), formed with axially spaced circumferential grooves 22 for releasable lock |
| 4476459 |
Theft detection method and apparatus in which the decay of a resonant circuit is detected |
October 9, 1984 |
| In an electronic theft detection apparatus the passage of a resonant circuit wafer 16 through an interrogation zone formed by transmitter and receiving antennas (30, 90) (32, 92) is detected by generating sharp pulses of electromagnetic energy to cause the resonant circuit wafer to r |
| 4384281 |
Theft detection apparatus using saturable magnetic targets |
May 17, 1983 |
| An electronic theft detection apparatus for detection of saturable magnetic targets has transmitter and receiver antennas formed of single turn loops of rigid metal pipe. The antennas are rectangular and have a width, in the direction of passage, through the interrogation zone, less than |
| 4326198 |
Method and apparatus for the promotion of selected harmonic response signals in an article detec |
April 20, 1982 |
| An electromagnetic article detection system of the type wherein a saturable magnetic target generates harmonics of an alternating magnetic interrogation field. A magnetic bias means is provided along with the magnetic interrogation field to promote the production of target response p |
| 4321586 |
Article theft detection |
March 23, 1982 |
| An electronic article theft detection system accurately senses the presence of a target on a protected article by sensing electromagnetic disturbances at a plurality of frequences, comparing their relative amplitudes and producing a detection signal when the compared relative amplitudes |
| 4299040 |
Fastening means |
November 10, 1981 |
| A fastening means for fastening a wafer to an article of merchandise and comprising a tack-like element whose shank passes through the merchandise and the wafer and a button-like fastening element which securely holds the shank of the tack-like element. The head of the tack-like element |
| 4274090 |
Detection of articles in adjacent passageways |
June 16, 1981 |
| An article theft detection system for identifying which of two adjacent passageways a protected article passes. Each passageway is provided with spaced apart interrogation and receiver antennas, but a single receiver antenna services both passageways. Multiplexing is used to energize the |
| 4187509 |
Wafer and fastener for use in electronic theft detection system |
February 5, 1980 |
| A wafer construction which includes an expansive, generally flat plastic member formed with a spiral groove in which an elongated electrical conductor is held in the shape of a coil. The plastic member is also formed with a recess in which a capacitor is contained. The capacitor is c |
| 4135184 |
Electronic theft detection system for monitoring wide passageways |
January 16, 1979 |
| An electronic theft detection system has a transmitting antenna and a receiving antenna located on the floor and overhead of a passageway being monitored. The antennas have conductors extending along and crossways of the passageway in staggered arrangement to provide system sensitivity f |
| 4118693 |
Method and apparatus for producing uniform electromagnetic fields in an article detection system |
October 3, 1978 |
| An electromagnetic article detection system of the type wherein a target having frequency selective electrical characteristics produces predetermined electromagnetic effects in response to an alternating electromagnetic field. A large resonant electric circuit is placed across an int |
| 4095214 |
Electronic monitoring system and responder device |
June 13, 1978 |
| An electronic monitoring system for monitoring the passage of objects, such as persons, past a monitoring station. An antenna is provided flat on the floor of the station to generate electromagnetic fields in the vicinity of the station and to generate electrical alarm signals whenever t |
| 4074249 |
Magnetic detection means |
February 14, 1978 |
| Magnetic detection means for protection of articles such as books, records and the like, wherein a target, of magnetically soft or easily saturable magnetic material, such as permalloy foil, is mounted on the protected article and emits magnetic signals which are harmonics of an interrog |
| 4016553 |
Article detection system with near field electromagnetic wave control |
April 5, 1977 |
| An electronic theft detection system includes antenna clusters connected to electromagnetic wave transmitter and receiver means. Each antenna cluster comprises a group of spaced apart parallel loops connected in phase opposition or bucking relationship. Electromagnetic waves emitted from |
