Abstract: A camera comprises an information-bearing medium movable to record predetermined information on a filmstrip. The information-bearing medium is a magnetic roller recorder on which is magnetically stored the information, and which is rotationally supported in place for stationary rolling contact with a magnetic track on a filmstrip as the filmstrip is advanced, whereby the information can be repetitively recorded along the magnetic track on the filmstrip. The magnetic roller recorder can be provided apart from the camera as an owner-personalization accessory for the camera.

Abstract: A magnetic field sensing system comprising:a magnetic field shielding structure including a series of N annular rings of inner diameter, a, outer diameter, b, and thickness, t, the series of magnetic rings being geometrically aligned so to be concentric to a common axis of concentricity, the number of rings N being equal to or greater than two, the rings being formed from a high permeability, magnetically soft ferromagnetic material of permeability .mu., and where the rings are physically separated from each other by a series of N-1 spacer layers made from any nonmagnetic material (including in part air), and which function to space the magnetic rings apart by a distance t', and wherein the series of N high permeability magnetic rings and N-1 nonmagnetic spacer layers form stack of length L=Nt+(N-1) t' along the direction parallel to the axis of concentricity; anda magnetic field sensor located within the structure aligned with common axis of concentricity.

Abstract: A filmstrip which has a substantially transparent magnetic layer is loaded into a camera. Successive sections of the filmstrip are moved inside the camera to locate corresponding sections of the magnetic layer adjacent an inside face of a magnetic-film-write-on portion of the camera. A hand held stylus is manually moved on an outside face of the magnetic-film-write-on portion, opposite the inside face, to record hand-generated information magnetically on the magnetic layer.

Abstract: A copyright protection system is provided in which copyrighted articles, such as documents and photos, have associated with the article magnetic material which is detected when the article is copied on a scanner/reproducing machine. The magnetic material may be secured to the article so that it cannot be removed without destroying the article, or the magnetic material may form part of the article. The scanner/reproducing machine is provided with a magnetic detection system for automatically detecting the copyrighted article.

Abstract: A credit and access control card and reader system comprising: a magnetically encodable card comprising a body having upper and lower surfaces and side and end edges, the body being formed of plastic material having magnetic particles uniformly dispersed throughout the plastic material; and a reader having a magneto resistive (MR) head for reading the magnetically encodable card as it is moved past the MR head.

Abstract: In order to measure the permeability of a magnetic material, a permanent magnet is positioned at a distance from the surface of a magnetic material. A first magnetic field sensor is placed proximate the magnetic material on the magnetic axis of the permanent magnet. The axis of sensitivity of the magnetic field sensor is perpendicular to the field of the permanent magnet and in a plane perpendicular to the surface of the magnetic material. A second magnetic field sensor for compensating for temperature and stray field effects can be positioned perpendicular to the magnetic axis of the permanent magnet with its axis of sensitivity parallel to the axis of sensitivity of the magnetic field sensor.

Abstract: Acicular barium ferrite (BaFe) particles with magnetic easy axes perpendicular to particle length are utilized as the magnetic particles in the recording medium of the invention. The BaFe particles are coated to lie "side by side", onto the medium's substrate with the particles' lengths lying in the plane he medium and transverse to the direction of medium motion during recording. The optimum particle orientation for support of both perpendicular and longitudinal components is where the easy axes of the particles are randomly oriented in an X-Y plane wherein the X axis Ks along the direction of media motion, and the Y axis is perpendicular to the recording layer. To effect this random orientation, the just coated particles are subjected to a rotating magnetic field whose rotating vector lies in the X-Y plane.

Abstract: A magnetically encodable card made of a solid plastic material having uniformly dispersed magnetic particles throughout the plastic material. The card is preferably formed of two major faces with connecting edges. Data can be recorded on one or both of the major faces, and can also be recorded on one or more of the card edges.

Abstract: A very high field micro roller magnetic recorder of 20 poles having an outside diameter of 0,130" is disclosed, as is the method for making such a micro roller magnetic recorder. The phrase, "very high field", as applied to the micro roller recorder of the present invention is defined as a surface field intensity of at least 1000 Oe. Rather than mounting discrete magnets around the periphery of a non magnetic drum in fabricating a magnetic roller recorder, the present invention teaches use of a magnetizable cylinder of high energy magnetic material, such as NdFeB, magnetized to saturation in a pattern of circumferentially located poles by use of a fixture fabricated as follows. A solid conducive cylinder is slotted in the axial direction to generate a serpentine conductive pattern to which lead wires are connected. The cylinder is potted in epoxy, and the center bored out to accept the small diameter high magnetic energy roller to be magnetized.

Abstract: Apparatus for detecting a magnetizable or conductive object which passes through a magnetic detecting field. The apparatus includes first and second spaced coils for producing a magnetic field between the spaced coils; first and second magnetic field detectors respectively located within the coils with their sensitive axes parallel to the direction of passage of a magnetizable object between the spaced coils and perpendicular to the primary field of the coils; and electrical circuitry coupled to the first and second magnetic field detectors for producing a detection signal in which common mode field noise and thermally induced noise is substantially eliminated.

Abstract: A magnetic assembly for detection and authentication of magnetic documents. The magnetic assembly includes a permanent magnet (PM), first and second magnetically soft high permeability pole pieces shaped to form a tapered, variable gap size magnetic circuit with the permanent magnet. The PM is located at a first gap between the first and second pole pieces. A magnetoresistive (MR) sensing element is located at or near the center of a second gap between said first and second pole pieces. The second gap and MR sensing element are proximate a magnetic document to be sensed. An electrical conductor is adjacent to the MR sensing element, but is electrically insulated therefrom. A direct current is passed through the electrical conductor to create a compensating bias field in the MR element which is combined with the bias field generated by the PM.