Abstract: To lessen thermal noise in a magneto-resistive head employing a slotted magneto-resistive sensing element, the present invention provides for such element to be plated with a highly thermally conductive film (e.g. gold, silver, copper, aluminum, etc.) exclusively in the slotted portion of the element. By restricting such plating to the slotted portion of the sensing element, the film thereon will be precluded from electrically short circuiting the magneto-resistive sensing element . . . while, at the same time, serving as an energy-spreading heat sink.

Abstract: Drawing on the observation that a signal which is magnetically recorded near the edge of a magnetic tape not only projects a magnetic field that is above (and below) the plane of the tape, but also projects a field that extends away from the edge thereof, the invention calls for (tracking-) control of relative head-to-tape positioning in response to the edge-projected field of a pre-recorded edge-positioned tracking control signal, whereby the tightness of such control is governed directly by the spacing loss equation.

Abstract: A flying head slider is flown above a rigid rotating magnetic disk at such a height that it is both aerodynamically stable and immune to collisions with disk asperities. A position adjustable magnetic transducer is mounted on the slider and is controllably lowered to an operating position very close to the disk where its position is maintained by a servo system. An anticipator probe detects the presence of asperities on the disk in the path traversed by the transducer, and generates a control signal which causes the transducer to be retracted to a safe height.

Abstract: An apparatus is disclosed for producing "hard" color copies of a video image utilizing line pattern rotation to reduce the visual perception of "raster" lines and improved image quality. Line pattern rotation is accomplished by rotating the raster line pattern of a CRT relative to the displayed image between each exposure of the color components of the composite video image.

Abstract: Given a medium comprised of a vertically recordable underlying region of a magnetic material and a cooperating overlying region of horizontally recordable material, the invention calls for the pre-recording of such tracking information, in the underlying region, that between adjacent tracks there occurs a vertically disposed flux reversal in the underlying region, each such track being approximately the width of a playback core disposed to read data recorded in the overlying region. Deposited on the side face of the playback core, in accordance with the invention, is a magneto-resistive element. So long as the playback core is on-track, the magneto-resistive element "sees" equal vertical fields on either side of the track edge; but should the playback core start to mistrack, the magneto-resistive element will see vertical flux of one or another polarity.

Abstract: A magnetic disk recording apparatus is disclosed having a synchronization modification circuit utilized to control the rotational speed of a magnetic disc, whereby an integer number of horizontal lines of a standard video signal are recorded on one annular track of the magnetic disc. When the recorded video signal is repeatedly reproduced, a non-interlaced single field "still" video image is displayed on a standard monitor adapted to display an interlaced image.

Abstract: A multitrack magneto-resistive head is comprised of an array of thin-film yoke-type core structures. In the back gap of each such core structure, there is a sense-current-carrying magneto-resistive flux responsive element. To prevent excessive sense current flow, and insensitivity as caused thereby, the invention teaches that slotting of the magneto-resistive element in the region thereof where such element connects into such back gap will alleviate both such problems.

Abstract: Given that there is a limit to the extent to which a record head may be excited before its pole tips saturate (gap fuzziness) while overwriting a second set of information signals atop a first set of information signals recorded in a high coercivity recording medium, the present invention concerns the discovery that if the record gap is dimensioned to equal approximately the flux change length that corresponds with a 2 f signal (FCL.sub.2) recorded atop a 1 f signal, i.e. if the record gap is somewhere between about 0.7 and 1.5 times the flux change length associated with the 2 f signal, erasure of the 1 f signal (as well as other signals) will be most effective.

Abstract: A closed loop circuit corrects digital data baseline shift resulting from perturbing interferences. Samples of the signal amplitude are stored at each clock time; and a correction signal is derived from the stored information. The correction signal is subtracted from the data signal to produce a resultant signal that is devoid of baseline shift, such resultant signal being also used to control clock regeneration in a phase locked loop.

Abstract: It has been found that, if a (negative) bias is applied to a substrate during the sputtering thereto of Alfesil, selective re-sputtering from the substrate film of aluminum and silicon will leave that film rich in iron and, attendantly, of higher saturation magnetization (17,000 gauss) than the starting material Alfesil (10,000 gauss). Such being the case, the invention provides that the sputtering of Alfesil-type material during the manufacture of a magnetic head be performed in two phases, first, while applying a bias of a first sense to a substrate to be sputtered upon, and, second, while applying a bias of different sense (e.g. a zero bias) to the substrate, thereby to cause a composite thin film to be formed on the substrate. The composition of the thin film in question is: 1. a (generally thin) region of material of high saturation magnetization layered with 2. a (generally thicker) region of lesser saturation magnetization.

Abstract: In accordance with the invention, an extremely narrow control track is provided. By recording such control track cross-wise with respect to data recorded in an adjacent information track, a flux sensitive head may be employed to read the recorded control track flux so as to detect, with great sensitivity, polarized flux directions on either side of the centerline of the control track. Such detected polarized flux directions are transformed into corresponding drive signals for corrective head (and/or medium) positioning, thereby to cause the flux sensitive head to follow the centerline of the control track.

Abstract: In a transversal filter equalizer, such as one using a tapped delay line, the present invention combines the symmetrically located pairs of tap signals, by means of adders and subtracters, to provide partial output signals which are separately controlled in amplitude and phase. These partial output signals, which have no d.c. components, are then summed with a partial signal derived from the center tap reference signal to reinsert the d.c. component and to provide the equalized output signal.

Abstract: The invention teaches that if a "shorted" electrically conductive turn--deposited on a magnetic substrate--is employed to sense recorded signal flux, then the underlying substrate will efficiently support flux induced about the shorted turn . . . and such induced flux will correspond proportionately to the recorded signal flux. In accordance with the invention, an MR element is so situated that it senses induced flux about the shorted turn at a location thereof that is remote from the medium whose signal flux is to be reproduced.

Abstract: In an effort to provide exceptionally high resolution playback of video information recorded in the environment of an electronic still camera, the invention calls for:(a) Use of double side band FM recording, which in the prior art would have been productive of playback interference between the side bands of harmonics and the side bands of corresponding fundamentals unless the relative head-to-media speed was high enough to accommodate high carrier frequencies.(b) Bias recording such FM video information, thereby to prevent the inherent production of harmonic information within the media.(c) Up-converting the harmonic-free playback signal, before the harmonic-causing procedure of amplitude-limiting such playback signal, thereby to cause such signal to have a spectrum-wise wide disparity between the modulated fundamental in question and its harmonics, as caused by such amplitude limiting.(d) Removing the generated harmonics (and their side bands) prior to or during demodulation of the modulated fundamental.

Abstract: A linear adjustment mechanism for a double-sided flexible disk head assembly includes a bearing slot formed in the rear surface portion of a lower transducer arm, a slide block carrier by the upper surface of the lower arm member and an upper transducer arm member. The slide block has a vertically arranged bearing aperture for accommodating a crank having an eccentric pin dimensioned to be received in the bearing slot and a shank portion dimensioned to be received in the bearing aperture in the slide block. Rotation of the crank shank provides a translational force via the bearing slot and bearing aperture between the first and second arm members.

Abstract: Because the lineal speed of a pre-recorded disc relative to a playback head depends on the radial position of the head with respect to the disc, the present invention calls for equalization that correspondingly varies as a function of the radial position of the playback head. Since the recorded tracks of the disc reside in a relatively narrow band about the disc--and because of the relatively large number of tracks within such band--an additional concept of the invention is to divide the band into head-position zones--each such zone corresponding to a different grouping of recorded tracks--and to employ equalization that is respective of the specified zones.

Abstract: Batch practices of magnetic film deposition and circuit structuring are merged upon a common semiconductor substrate (chip) for both circuit and head parts. As to any one head being formed, the substrate is suitably doped and metallized to form electronics designed for cooperation with such head; then, thin films (cores) of magnetic material are deposited on the semiconductor substrate for cooperation with the electronics. After the thin film head cores are appropriately gapped, a (common) yoke is brought into contact with them . . . the substrate being thereafter contoured through its underside to expose the thin film core gaps.

Abstract: During a first phase of operation for a disc player incorporating the invention, a derived playback signal which is "above" a signal level of a threshold effects head motion in a given direction. During a second phase of disc player operation, the derived playback signal is again compared with the threshold, only this time a signal that is "below" the threshold effects head motion in the "same" given direction. During a third phase of operation, the derived signal, when at or above the threshold, initiates an incremental drive for the head. Such a drive steps the head in the given direction so long as the lowest playback signal level, during each given disc rotation, continues to increase. Thus, during this third phase of disc player operation, the head settles to a track location which is "invariantly" maximized. This means, therefore, that track eccentricity has absolutely no influence during playback of the track.

Abstract: To reconcile a variety of problems associated with multitrack magnetic heads, modified shields therefor were fabricated. Each such shield is comprised of a plurality of laminations of magnetically, and mechanically, soft material bonded together into a unitary stack of appropriate thickness. The laminations are typically of .mu.-metal; and the stacked laminations are preferably provided with copper cladding as is the practice in the art. At the medium bearing surface of the shield, a cutout is provided; and into such cutout a small insert of magnetically soft, mechanically hard, material, e.g. Sendust, is provided.

Abstract: The disclosed apparatus provides for an image to be "beam-split" between (typically) two similar--but defective--imagers. While the two imagers in question are similar in all respects, the locations of their respective defective pixels are not. Respective programmable read-only-memories (PROMS) cooperate with each of the imagers and serve to memorize the locations of the defective pixels of the imagers. If the two imagers are scanned simultaneously, then, by toggling between the imagers each time a defective pixel is read in either of the imagers, a perfect video signal (regardless of whether the imagers have isolated defective pixels, or whether such defective pixels are aligned along given rows or columns of the imagers) may be provided.