Abstract: Methods, apparatus, systems and articles of manufacture (e.g., physical storage media) to detect media watermarks in magnetic field data are disclosed herein. Example media monitors disclosed herein include a magnetic field estimator to determine first magnetic field data, the magnetic field estimator in communication with a magnetometer. Disclosed example media monitors also include a correlator to correlate the first magnitude field data with a reference sequence to determine second magnetic field data. Disclosed example media monitors further include a watermark decoder to process the second magnetic field data to detect an audio watermark encoded in an audio signal.
Abstract: A magnetic recording medium includes a substrate, a magnetic layer including an alloy having an L10 type crystal structure as a main component thereof, and a plurality of underlayers arranged between the substrate and the magnetic layer. The plurality of underlayers include at least one crystalline underlayer which has a (100) orientation, and includes W as a main component thereof and one or more kinds of elements selected from a group consisting of Fe, Ni, Co, Hf, Zr, Y, Be, Ce, La, and Sc.
Type:
Application
Filed:
October 1, 2014
Publication date:
April 30, 2015
Inventors:
Lei ZHANG, Tetsuya KANBE, Yuji MURAKAMI, Kazuya NIWA
Abstract: An aspect of the present invention relates to glass for a magnetic recording medium substrate, which comprises essential components in the form of SiO2, Li2O, Na2O, and one or more alkaline earth metal oxides selected from the group consisting of MgO, CaO, SrO, and BaO wherein a molar ratio of a content of CaO to a combined content of MgO, CaO, SrO, and BaO (CaO/(MgO+CaO+SrO+BaO)) is equal to or less than 0.20, and which has a glass transition temperature of equal to or higher than 650° C.
Abstract: A method for manufacturing a magneto-optical recording medium in which reading of recorded information is performed through domain wall displacement in a reproduction layer is provided, in which magnetic separation of groove side-wall portions is performed more reliably; as a result a magneto-optical recording medium with satisfactory recording and reproduction characteristics can be provided.
Abstract: A magneto-optical medium has a recording layer having a plurality of columns extending in a lamination direction, and a reproduction layer which is placed below the recording layer and which functions as a nucleus for the columns.
Abstract: A magnetic recording medium comprises an information-recording film and a ferromagnetic film on a substrate. The information-recording film is composed of, for example, an amorphous ferrimagnetic material having perpendicular magnetization. Further, the ferromagnetic film is composed of a magnetic material which has saturation magnetization larger than that of the information-recording film. Accordingly, the leak magnetic flux from the ferromagnetic film is larger than that from the information-recording film. The magnetic recording medium and a magnetic recording apparatus are obtained, which are excellent in thermal stability and which are preferred to perform super high density recording.
Abstract: A magneto-optical recording medium has a configuration such that information recorded can be read from a region smaller than a beam spot by applying an external magnetic field and directing a light beam in reproducing. The magneto-optical recording medium includes a magnetic recording layer for recording and holding information, a magnetic reproducing layer provided on one side of the magnetic recording layer on which the light beam is incident, a nonmagnetic layer provided on another side of the magnetic recording layer opposite to the magnetic reproducing layer, and a magnetic assist layer provided on the nonmagnetic layer. The magnetic assist layer has a coercive force smaller than an external magnetic field applied in recording or reproducing information.
Abstract: A magneto-optical recording medium includes at least: a reproducing magnetic layer composed at least of Gd and Co showing an in-plane magnetization state at room temperature and a transition to a perpendicular magnetization state at temperatures of not lower than a critical temperature; and a recording magnetic layer formed of a perpendicular magnetization film, the reproducing magnetic layer and the recording magnetic layer being magneto-statically coupled at least in the vicinity of the critical temperature, the reproducing magnetic layer containing at least either Tb or Dy so as to increase the total magnetization at a temperature at which a perpendicular magnetic anisotropy constant and a diamagnetic field energy are equal to each other.