Abstract: A particulate magnetic recording media wherein the magnetic particles are substantially spherical. The spherical particle shape makes possible a media which is magnetically isotropic, well dispersed and low in noise, and free of magnetically inferior broken particles.

Abstract: An ink jet printing apparatus adapted to producing images using inks having predetermined concentrations of a magnetic label material therein, includes a printhead; an ink delivery system adapted to provide inks to the printhead; and a magnetic sensor associated with the ink delivery system, said sensor being sensitive to the magnetic label material in the ink and adapted to produce a signal which is characteristic of the concentration of the label material in the ink; wherein said magnetic sensor includes a horseshoe permanent magnet having first and second pole faces and a pair of magnetic field sensors located symmetrically between said pole faces having their axes of magnetic field sensitivity aligned perpendicular to the fixed field of said permanent magnet such that no signal is produced from said fixed field.

Abstract: A single use camera is preloaded with a roll of magnetically coated film with defined image frames. The camera has an exposure system for selectively exposing an image frame of the film in one of a plurality of image formats. The camera also includes a manually actuated mechanism coupled to a mounted permanent magnet. The magnet is movable to record a magnetic mark on the magnetically coated film at a predetermined location relative to an exposed image frame. The location of the mark is indicative of the image format of the exposed image frame.

Abstract: A dual purpose camera comprising has an optical exposure system for exposing a scene to unexposed film loaded in the camera, thereby producing a latent image in the film, and has an electronic image capture system for producing an electronic image from a developed image on processed film loaded in the camera.

Abstract: Apparatus for reading magnetically stored data from a wide range of magnetic media. The apparatus includes a magnetoresistive MR head for producing a signal representative of stored magnetic data and a hysteresis comparator circuit for processing the signal from high concentration media. The MR head is preferably a paired MR head having a preamplifier circuit which provides the bias current for the PMR head, amplifies the signal produced by the PMR head, and provides rejection of common mode signals.

Abstract: A pair of Hall sensors are symmetrically positioned between the poles of a horseshoe magnet. The Hall sensors are mounted in a plane flush with the ends of the magnet faces, and are located equidistant from the centerline of the magnet. A small magnetic object in the field of the magnet, preferably located on the magnet axis, has an induced dipole moment which is detected by the Hall sensors. The small magnetic object dipole field is such that the flux at each Hall sensor is in opposite directions, and by differentially sensing the outputs of the Hall sensors, a signal proportional to the magnetic object is derived. Leakage flux from the magnet as well as the flux of the earth's magnetic field, are in the same direction at both Hall sensors, and their effects are zeroed out by the differential sensing of the Hall sensors' outputs. When the poles of the magnet are drawn across the surface of a non magnetic sheet of conductive material, eddy currents are induced in the sheet by the moving magnetic field.

Abstract: A camera includes an enclosure having a front surface for supporting an optical section relative to an optical axis intersecting an image receiver supported relative to a back surface, and a lens positioned in the optical axis on the front surface of the camera and projecting a field of view forwardly of the camera. A plurality of thin elements are arrayed on the front surface of the camera around the lens in general correspondence with the field of view. Framing accuracy is improved for self portraits and the like by canting each element outwardly from the optical axis at such an angle that an inside surface of every element is visible to a subject positioned within the field of view of the lens.