Angle-modulation Recording (angle Modulation H03c; Demodulation Of Angle Modulated Oscillations H03d) {g11b 20/06} Patents (Class G9B/20.007)
  • Publication number: 20130148223
    Abstract: A method, apparatus, and system are provided for implementing spin-torque oscillator (STO) sensing with a demodulator for hard disk drives. The demodulator measures an instantaneous phase of the readback signal from a STO sensor and converts the readback signal into a signal that is proportional to the magnetic field affecting the STO frequency during a bit time. The converted signal is used for processing by conventional data detection electronics.
    Type: Application
    Filed: December 9, 2011
    Publication date: June 13, 2013
    Applicant: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Patrick Mesquita Braganca, Richard Leo Galbraith, Bruce Alvin Gurney, Neil Smith, Bruce Wilson, Rehan Ahmed Zakai
  • Publication number: 20130148224
    Abstract: A method, apparatus, and system are provided for implementing spin-torque oscillator sensing with an enhanced integrated demodulator for hard disk drives. The demodulator receives an input signal from a STO read sensor having an oscillation frequency ? related to the strength of the detected magnetic signal field. The demodulator includes a pair of mixers coupled to a quadrature reference oscillator with respective quadrature components cos(?0t), and sin(?0t) of the quadrature reference oscillator being mixed with a received input signal to form signals at the sum and difference frequencies, ?±?0. Each of these mixer products is lowpass filtered by a respective a lowpass filter to remove the sum frequency components for providing a demodulator output signal that is directly proportional the STO oscillation frequency ?. The demodulator output signal is used for processing by data detection electronics.
    Type: Application
    Filed: December 9, 2011
    Publication date: June 13, 2013
    Applicant: Hitachi Global Storage Technologies Netherlands. B.V.
    Inventors: Patrick Mesquita Braganca, Richard Leo Galbraith, Bruce Alvin Gurney, Neil Smith, Bruce Wilson, Rehan Ahmed Zakai
  • Publication number: 20110157736
    Abstract: A hard disk drive (HDD) including a slider. The slider includes a resistive temperature detector (RTD) configured to detect a temperature generated by one or more of slider spacing and contact with a media of said HDD. HDD also includes a slider signal controller configured to control bias signal of a slider with respect to a media potential, a real-time media-disk fly-height and contact detector configured to detect one or more of temperature generated by real-time media-disk slider spacing and real-time media-disk contact, and a real-time relative fly-height determiner configured to detect real-time relative fly-height of the slider based on analysis of a modulated portion of a high-frequency signal coupled to an element of the slider.
    Type: Application
    Filed: December 31, 2009
    Publication date: June 30, 2011
    Inventors: John CONTRERAS, Bernhard E. Knigge
  • Publication number: 20110013304
    Abstract: A magnetic head, includes a magnetic oscillation element, the oscillation frequency of which is modulated by a medium magnetic field, and a reproducing device configured to detect a phase difference between the adjacent oscillation signals derived from the magnetic oscillation element and output a phase difference signal as a reproduced signal.
    Type: Application
    Filed: September 24, 2010
    Publication date: January 20, 2011
    Inventors: Rie Sato, Koichi Mizushima
  • Publication number: 20090086354
    Abstract: A magnetic head, includes a magnetic oscillation element, the oscillation frequency of which is modulated by a medium magnetic field, and a reproducing device configured to detect a phase difference between the adjacent oscillation signals derived from the magnetic oscillation element and output a phase difference signal as a reproduced signal.
    Type: Application
    Filed: September 19, 2008
    Publication date: April 2, 2009
    Inventors: RIE SATO, Koichi Mizushima