Abstract: A microwave radiation absorbing adhesive comprises dissipative particles bound in a thermoplastic or thermosetting adhesive The absorbing adhesive may be applied directly to the surface of any object, or to an irregularly shaped object, or into cracks or crevices in or between objects, including conventional absorbers. Several types of dissipative particles and adhesives may be used.

Abstract: Retroreflective cube corner elements are arranged within layered articles at positions proximate a neutral axis to optimize their performance upon bending or twisting of the article. The elements and surfacs may be embodied in flexible sheeting materials suitable for curving about an object.

Abstract: A microwave radiation absorbing adhesive comprises dissipative particles bound in a thermoplastic or thermosetting adhesive. The absorbing adhesive may be applied directly to the surface of any object, or to an irregularly shaped object, or into cracks or crevices in or between objects, including conventional absorbers. Several types of dissipative particles and adhesives may be used.

Abstract: A magneto optic recording medium comprising a substrate, an amorphous magnetizable rare earth-transition metal alloy layer, a transparent dielectric layer on at least one side of the magnetizable layer, and a reflective surface located to reflect light through the magnetizable alloy layer. The dielectric layer is comprised of silicon carbide of the formula SiC.sub.x, wherein x, the molar ratio of carbon to silicon, is greater than 1. The dielectric layer is preferably deposited by direct current magnetron sputtering at low argon partial pressure from an electrically conductive mixture of silicon carbide and carbon. The medium exhibits similar or improved characteristics over media constructed with present dielectrics, for example, silicon suboxide (SiO.sub.y, y<2).

Abstract: An apparatus for use with magnetically based electronic article surveillance systems employing certain types of markers includes a hollow core having a gap in its perimeter, a coil of wire wrapped around a portion of the core, and appropriate circuitry to drive the combination as an electromagnet. The gap configuration produces an external field of large intensity but limited range, such that the magnetizable portion of a marker is magnetized without affecting magnetic states of the article to which the marker is affixed. Depending on the nature of the circuit, the apparatus may be used as a desensitizer of such markers, or preferably as a resensitizer. The resensitizer incorporates a proportional-integral controller that keeps the level of the alternating current constant.

Abstract: Retroreflective elements, such as cube-corner elements or right triangular prisms containing cube-corners, are arranged on articles to define separation surfaces between the elements; in another embodiment, the elements are truncated cube-corners incorporating similar surfaces on the elements themselves. If the surfaces are transparent they will transmit light through the article, rendering it partially transparent and partially retroreflective. The surfaces may be flat or curved. Standard grooving techniques may be employed to construct the elements, using mold cutting tools having flattened or curved tips instead of V-shaped tips; alternatively, electroformed molds may be lapped to include the shape required to produce surfaces. The elements and surfaces may be embodied in sheeting materials or internally illuminated signs.

Abstract: A conformable electromagnetic radiation suppression cover comprising one or more absorbing material(s) and a sealant. The cover conforms to the shape of a reflecting structure due to forces internal to the absorbing material(s) when the cover is subjected to an agent external to the cover. The absorber comprises dissipative particles bound in a conformable polymeric binder. The sealant is positioned to seal the conformable cover to the reflecting structure, and provides environmental protection to the structure and preferably better adhesion between the cover and the structure. In a preferred embodiment, the volume of the cover is varied before shrinkage to produce a cover thickness in the direction of incident radiation, as measured after shrinkage, which produces a preselected resonant frequency for the cover. The cover may include a conductive surface, such as a metallic foil. Impedance matching materials are preferred but not required.

Abstract: A magneto optic recording medium comprising a substrate, an amorphous magnetizable rare earth-transition metal alloy layer, a transparent dielectric layer on at least one side of the magnetizable layer, and a reflective surface located to reflect light through the magnetizable alloy layer. The dielectric layer is comprised of silicon carbide of the formula SiC.sub.x, wherein x, the molar ratio of carbon to silicon, is greater than 1. The dielectric layer is preferably deposited by direct current magnetron sputtering at low argon partial pressure from an electrically conductive mixture of silicon carbide and carbon. The medium exhibits similar or improved characteristics over media constructed with present dielectrics, for example, silicon suboxide (SiO.sub.y, y<2).

Abstract: A magneto-optic recording medium records data in a single, direct-overwrite step. The medium includes a magneto-optical storage layer and a magnetic biasing layer disposed in selected heat conductive relationship with the storage layer. The first magnetic field is generated externally of the storage layer at a first energy level of a laser to set the magnetic orientation of domains at the storage layer. At a second energy level of the laser, which is higher than the first energy level, the magnetic biasing layer provides a second magnetic field greater than the first magnetic field for setting the magnetic orientation of domains in the storage layer.

Abstract: An electromagnetic radiation absorber is formed by dispersing into a dielectric binder acicular magnetic metallic filaments with an average length of about 10 micron or less, diameters of 0.1 micron or more, and aspect (length/diameter) ratios between 10:1 and 50:1. Preferably the average length is about 5 micron, the aspect ratios are between 10:1 and 25:1, and the dielectric binder is polymeric. The volume fraction of the filaments may be lower than 35% of the total and still provide satisfactory absorption. An absorbing paint is formed by dissolving the absorber in a base liquid. The absorber or absorbing paint may be applied to a conductive surface, such as a metallic wire, plate or foil. Impedance matching materials are preferred but not required.

Abstract: A light source substantially longer than its diameter exhibits two different optical characteristics, such as two different colors, depending upon the direction along the long axis from which it is viewed. The light source comprises a light conduit employing total internal reflection and two illumination sources directing light into the light conduit from opposite ends.

Abstract: A method for producing a magneto-optic layer includes depositing amorphous magnetizable film layer on a substrate using a triode sputtering process. The magneto-optic layer includes an alloy of terbium, cobalt, iron, chromium and an oxygen content approximately between 2-6 atom percent midway through the thickness of the layer.

Abstract: An internally illuminated sign employs retroreflective sheeting with optically transmissive bonds between cover layer and base layer, thereby making the sign suitable for applications where visibility of the sign is required if the internal illumination source fails. A light conduit may be employed to allow the source of internal illumination to be remote from the interior of the sign enclosure. Total internal reflection type sheeting also may be employed to diffuse the internal illumination.

Abstract: A method for producing a magneto-optic layer includes depositing amorphous magnetizable film layer on a substrate using a triode sputtering process. The magneto-optic layer includes an alloy of terbium, cobalt, iron, chromium and an oxygen content approximately between 2-6 atom percent midway through the thickness of the layer.

Abstract: A retroreflective tubing adapted to be interwined among spokes of a wheel, comprising a core material, retroreflective microspheres attached to an outer surface of the core material, and a protective encapsulating material surrounding the microspheres. In a preferred embodiment, the cross section of the core material is U-shaped to maximize the retroreflective performance of the tubing, and the encapsulating material provides a multiplicity of sealed airspaces between the outer surface of the retroreflective microspheres and the inner surface of the encapsulating material.

Abstract: Markers in different portions of the interrogation zone of an electromagnetic article surveillance system produce signals with waveforms of different character. In one embodiment, a false alarm minimization method determines the character of the waveform of the signal induced in the detection antenna. A requirement that signals with waveforms of different character be sensed provides greater confidence that the marker is passing through, as opposed to being near one portion of, the interrogation zone. Also, false alarms produced by stationary objects such as metallic door and window frames are eliminated. In another embodiment, the direction in which the marker passes through the interrogation zone is determined.

Abstract: Stretched surface recording disk (SD) 10 comprises an annular support 12 having raised annular ridges 44 and 32 at or near its inside and outside diameters 22 and 30 with a base portion 24 in between the two ridges, and two annular recording medium films 14 and 16 held in radial tension and stretched across the base portion by adhering the film near the inside and outside diameters. The major principal orientation axis of each annular recording medium film 14 and 16 is determined and the SD assembled so that the axes are aligned in the same direction. This aligning results in SD with reduced track anisotropy due to warping of the annular support 12. As a result, data tracks are more stable than in previous SD, track density can be greaterd, and the SD is generally more reliable.

Abstract: A system for controlling removal of articles from a facility by authorized users transmits data to, and receives data from, an article inventory control system and an electronic article surveillance system, either or both of which may be pre-existing. The inventive system comprises a terminal which identifies the user and article, transmits the user and article identification data to the article inventory control system, receives article removal authorization data from the article inventory control system, verifies the identity and number of articles to be removed, and enables the user to remove the article through the electronic article surveillance system. The preferred embodiment is adapted for a library, and is designed to provide library patrons with the ability to check books out of the library without staff assistance.

Abstract: A monitor for detection of temperature and/or steam conditions indicative of sterilization. The monitor comprises means for creating a remotely detectable response upon interrogation by an electromagnetic field and means for changing the response upon exposure to a predetermined set of temperature and steam conditions. The remotely detectable response is preferably produced through the interaction of an electromagnetic interrogation field with magnetic components of the monitor, wherein the characteristic harmonic response generated by the magnetic components is either inhibited or enabled by the change in configuration of one or more elements of the detector. Sterilization conditions are detected through one or more compounds known to have melting points which are above the temperature used in the sterilization process. Melting of the chemical compound produces the change in configuration of the element or elements of the monitor.