Abstract: In an electronic article surveillance (EAS) system, a frequency-dividing transponder that responds to detection of electromagnetic radiation of a first predetermined frequency by transmitting electromagnetic radiation of a second predetermined frequency that is a frequency-divided quotient of the first predetermined frequency, includes an active strip of amorphous magnetic material having a transverse uniaxial anisotropy defining a magnetomechanical resonant frequency in accordance with the dimensions of the strip at the second predetermined frequency when magnetically biased to be within a predetermined magnetic field intensity range so as to respond to excitation by electromagnetic radiation of the first predetermined frequency by transmitting electromagnetic radiation of the second predetermined frequency; and a tripole strip of magnetic material of such coercivity and so disposed in relation to the active strip of magnetic material as to create a magnetomechanical resonance in the active strip at the firs

Abstract: An EAS presence detection system includes a transmitter for transmitting an electromagnetic radiation signal of a first predetermined frequency into a surveillance zone; a tag for attachment to an article to be detected within the surveillance zone, the tag containing a transponder including a material that, when in the presence of a magnetic bias field within a predetermined magnetic field intensity range, responds to detection of electromagnetic radiation of the said first predetermined frequency by transmitting electromagnetic radiation of a second predetermined frequency that is either a multiple harmonic or a frequency-divided quotient of the first predetermined frequency or at the first frequency; a detection system disposed for detecting radiation of the second predetermined frequency within the surveillance zone; and a magnetic field source for providing a magnetic bias field within the predetermined magnetic field intensity range within the surveillance zone.

Abstract: The tag includes an active strip of magnetic material that, when in the presence of a magnetic bias field within a predetermined magnetic field intensity range, responds to excitation by electromagnetic radiation of a first predetermined frequency by radiating electromagnetic radiation of a second predetermined frequency that is a frequency-divided quotient of the first predetermined frequency; and a pair of bias strips of magnetic material disposed in relation to the active strip in a common housing with the active strip for magnetically biasing the active strip with a magnetic bias field within the predetermined magnetic field intensity range. The bias strips are cut from an extruded magnetic material ribbon having a width less than the length of the active strip and a magnetic moment parallel to the lateral dimension of the ribbon.

Abstract: A pin-and-clutch theft-deterrent device that enables instantaneous detection of separation-force tampering with the theft-deterrent device. The device includes a pin in one component and a clutch assembly in a second component for attaching the device to an article to be protected by grasping the pin with the clutch to provide a predetermined retaining force for resisting separation of the components by prying or pulling the components apart; a force-sensitive switch assembly for detecting application to the two components of at least a predetermined threshold separation force applied in opposition to the predetermined retaining force; and a transponder coupled to the switch assembly for responding to an irradiated interrogation signal by radiating an alarm signal when the switch assembly detects application to the two components of at least the predetermined threshold separation force.

Abstract: A clamp includes a U-shaped member having a pair of legs, with each leg having a cavity in the side of the leg facing the other leg; and a clutch for receiving and restraining the legs of the U-shaped member. Pads are attached to the insides of the legs for clamping an article between the legs to deter the theft of such article. The clutch includes a housing defining a pair of longitudinal channels for respectively receiving the legs of the U-shaped member and a chamber between the channels, with the chamber being open to the channels; two bails disposed for movement within the chamber; a highly magnetically attractive plunger disposed within and at one end of the chamber; and a spring for biasing the plunger to move into such contact with the balls as to force the balls against respective inclined surfaces disposed at the other end of the chamber for respectively guiding the balls toward different channels.

Abstract: A batteryless, portable, frequency divider includes a first resonant circuit that is resonant at a first frequency for receiving electromagnetic radiation at the first frequency; and a second resonant circuit that is resonant at a second frequency that is one-half the first frequency for transmitting electromagnetic radiation at the second frequency; and a circuit element electrically connecting the first resonant circuit to the second resonant circuit.

Abstract: A clamp for use as a theft deterrent device includes a U-shaped member having first and second legs, with each leg including a shelf disposed on the inside edge of the member and extending laterally toward the opposite leg; a housing defining a pair of longitudinal channels for receiving the legs of the U-shaped member and a slot extending between the longitudinal channels; a pair of overlapping plates disposed for separate movement within the slot into and away from different ones of the longitudinal channels, with each plate including a row of teeth disposed on a longitudinal edge of the one plate that moves into one channel for engaging the shelf on one leg of the U-shaped member received by said one channel to prevent removal of the one leg from the channel.

Abstract: An apparatus for releasing locked components of a theft-deterrent device includes a seat for receiving a component of the theft deterrent device that contains a clutch and a ferromagnetic anvil that is positioned by a spring to force the clutch to apply pressure against an inserted pin that is anchored in another component of the device so as to restrain the pin from release from the clutch; and a magnet with a pole piece coupled thereto, with the magnet and the pole piece being disposed for movement between a protracted position and a retracted position. When magnet and the pole piece are in their protracted position the pole piece is disposed about the sides of the clutch-containing component and applies magnetic flux from the magnet that is directed to overcome the force of the spring and reposition the ferromagnetic anvil to thereby relax the pressure applied against the pin by the clutch so that the pin-anchoring component can be released from the clutch-containing component.

Abstract: A batteryless, portable, frequency divider according to the present invention includes a first resonant LC circuit that is resonant at a first frequency for receiving electromagnetic radiation at the first frequency; and a second resonant LC circuit that is resonant at a second frequency that is one-half the first frequency for transmitting electromagnetic radiation at the second frequency. The first circuit is coupled only magnetically to the second circuit to transfer energy to the second circuit at the first frequency in response to receipt by the first circuit of electromagnetic radiation at the first frequency. The second circuit includes a variable reactance element, such as a variable capacitance diode or varactor, in which the reactance varies with variations in energy transferred from the first circuit for causing the second circuit to transmit electromagnetic radiation at the second frequency in response to the energy transferred from the first circuit at the first frequency.

Abstract: A batteryless, portable, frequency divider according to the present invention includes a first resonant LC circuit that is resonant at a first frequency for receiving electromagnetic radiation at the first frequency; and a second resonant LC circuit that is resonant at a second frequency that is one-half the first frequency for transmitting electromagnetic radiation at the second frequency. The first circuit is coupled only magnetically to the second circuit to transfer energy to the second circuit in response to receipt by the first circuit of electromagnetic radiation at the first frequency. Each circuit includes a variable reactance element, such as a variable capacitance diode or varactor.

Abstract: In a device for deterring theft of a protected article, including a pin and clutch respectively embodied in two components that are adapted to be locked together on opposite sides of a portion of the protected article to prevent unauthorized removal of the device from the article, the pin-containing component contains two fragile elongated glass vials that fracture when at least a predetermined pressure is applied thereto, with the vials containing a detrimental substance that would damage an article attached to the device if such substance were to be released from the vial; and the head of the pin includes a breaker element having a wedge-shaped surface of a fiber-loaded-reinforced thermoplastic, (which does not scratch glass), for applying more than the predetermined pressure against the vial in response to the pinhead being moved in response to application to the two components of at least a predetermined threshold separation force, to thereby completely fracture the vials by inducing a high bending stress

Abstract: A device for deterring theft of a protected article, including a pin and clutch for attaching the device to the article, with the pin and clutch being embodied in two components that are adapted to be locked together on opposite sides of a portion of the protected article to prevent unauthorized removal of the device from the article. One component includes a plurality of fragile elongated vials that fracture when flexed longitudinally, with each vial containing a detrimental substance that would damage the article if the vial were to be fractured while the device was attached to the article.

Abstract: A clutch mechanism includes a ferromagnetic anvil having an axial bore for axially receiving a pin; a cup axially aligned with the anvil for receiving a pin that is axially received by the bore of the anvil, wherein the anvil is longitudinally movable along its bore axis with respect to the cup; a spring for forcing the anvil toward a confining end of the cup; balls in the cup for engaging the pin when the anvil is forced toward the confining end of the cup, with the balls being disposed to apply radial pressure against the pin to firmly clutch the pin and thereby restrain the pin from longitudinal movement when the balls are forced toward the confining end of the cup; and a ferromagnetic shield disposed axially in relation to the anvil for diffusing magnetic flux applied axially to the anvil by a magnet external to the clutch mechanism so as to prevent less than a predetermined amount of the axially applied magnetic flux from overcoming the spring and forcing the anvil to move away from the confining end of

Abstract: A magnetometer for detecting variations in a DC magnetic field. The magnetometer includes a magnetic field variation sensitive device that resonates at a characteristic resonant frequency by converting energy stored therein as a result of being excited by electromagnetic radiation at twice the resonant frequency when biased by a DC magnetic bias field within a predetermined field intensity range in which the amplitude of the resonance varies with variations of the field intensity.

Abstract: A method of deactivating a frequency-dividing-transponder that includes an active strip of magnetic material that, when magnetically biased to be within a predetermined magnetic field intensity range, responds to excitation by electromagnetic radiation of a first predetermined frequency by radiating electromagnetic radiation of a second predetermined frequency that is a frequency-divided quotient of the first predetermined frequency; and a magnetized bias strip of magnetic material having first and second ends and disposed in relation to the active strip of magnetic material for magnetically biasing the active strip of magnetic material to be within the predetermined magnetic field intensity range only when the bias strip of magnetic material is magnetized includes the step of converting the bias strip of magnetic material into a tripole bar magnet, having a pole of one magnetic polarity in a predetermined region of the strip located between the ends of the strip, and having a pole of a different magnetic pol

Abstract: A process for making a paper product that includes both means for preventing images from being copied from the paper product by use of a xerographic photocopier; and means for enabling detection of the paper product when the paper product is transported through an interrogation zone of an article surveillance system.

Abstract: A device for deterring theft of a protected article, including a pin and clutch for attaching the device to the article, with the pin and clutch being embodied in two components that are adapted to be locked together on opposite sides of a portion of the protected article to prevent unauthorized removal of the device from the article. The pin has a head that is anchored within one component; and the clutch in the other component grasps the pin to provide a predetermined retaining force for resisting separation of the components by prying or pulling the components apart.

Abstract: A presence-detection-system tag in which a frequency-dividing transponder may be decisively deactivated notwithstanding the intensity of the ambient magnetic field.

Abstract: A paper product includes both means for preventing images from being copied from the paper product by use of a xerographic photocopier; and means for enabling detection of the paper product when the paper product is transported through an interrogation zone of an article surveillance system.

Abstract: In a device for deterring theft of a protected article, including a pin and clutch respectively embodied in two components that are adapted to be locked together on opposite sides of a portion of the protected article to prevent unauthorized removal of the device from the article, the pin-containing component contains two fragile elongated glass vials that fracture when at least a predetermined pressure is applied thereto, with the vials containing a detrimental substance that would damage an article attached to the device if such substance were to be released from the vial; and the head of the pin includes a breaker element having a wedge-shaped surface of a fiber-loaded-reinforced thermoplastic, (which does not scratch glass), for applying more than the predetermined pressure against the vial in response to the pinhead being moved in response to application to the two components of at least a predetermined threshold separation force, to thereby completely fracture the vials by inducing a high bending stress