Patents Assigned to Hitachi Global Storage Technologies
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Publication number: 20130148234Abstract: In one embodiment, a hard disk drive includes a magnetic disk medium, a magnetic head adapted for writing data to the magnetic disk medium, a mechanism (such as a detection circuit) adapted for detecting at least one recording condition of drive current provided to the magnetic head during writing operations, and an energy conversion element for controlling at least one recording characteristic of the magnetic head in response to the at least one detected recording condition. According to another embodiment, a method includes writing data to a magnetic medium using a magnetic head, detecting at least one recording condition of drive current provided to the magnetic head during the writing, and controlling at least one recording characteristic of the magnetic head during the writing using an energy conversion element in response to the at least one detected recording condition.Type: ApplicationFiled: December 12, 2011Publication date: June 13, 2013Applicant: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Akira Morinaga, Nobumasa Nishiyama, Keiichi Nagasaka
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Publication number: 20130148224Abstract: 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: ApplicationFiled: December 9, 2011Publication date: June 13, 2013Applicant: Hitachi Global Storage Technologies Netherlands. B.V.Inventors: Patrick Mesquita Braganca, Richard Leo Galbraith, Bruce Alvin Gurney, Neil Smith, Bruce Wilson, Rehan Ahmed Zakai
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Publication number: 20130148223Abstract: 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: ApplicationFiled: December 9, 2011Publication date: June 13, 2013Applicant: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Patrick Mesquita Braganca, Richard Leo Galbraith, Bruce Alvin Gurney, Neil Smith, Bruce Wilson, Rehan Ahmed Zakai
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Publication number: 20130148228Abstract: A magnetic recording system configured for recording to a bit patterned media using both hypertrack recording and shingled recording. The magnetic recording system includes a write pole with a notched trailing edge that results in a write bubble with a trailing edge that has two outer convex lobes separated by a centrally disposed concave region. By locating one of the lobes over first and second data tracks of a hypertrack, a proper alignment of the relative phase of the two tracks can be maintained. Further adjustment to the alignment can be achieved by adjusting the radial location of the write head.Type: ApplicationFiled: December 7, 2011Publication date: June 13, 2013Applicant: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Thomas R. Albrecht, Prakash Kasiraj
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Publication number: 20130148229Abstract: A method, apparatus, and system for implementing spin-torque oscillator (STO) sensing with an enhanced delay control feedback circuit for hard disk drives. A detector receives an input signal from a STO read sensor having an oscillation frequency related to the strength of the detected magnetic signal field. The received input signal is mixed with a time delayed input signal for providing a detector output signal. A low frequency component signal of the detector output signal is monitored and a delay control feedback is applied to an adjustable time delay to bias the DC signal of the detector output signal.Type: ApplicationFiled: December 9, 2011Publication date: June 13, 2013Applicant: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Patrick Mesquita Braganca, Richard Leo Galbraith, Bruce Alvin Gurney, Neil Smith, Bruce Wilson, Rehan Ahmed Zakai
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Publication number: 20130148231Abstract: A magnetic disk drive system that has a suspension assembly that includes a slider having a heating element and a suspension configured with a protective structure that protects the heating element. The heating element of the slider can extend through the suspension to extend from the suspension assembly from a side that is opposite the slider. The protective structure is configured to protect the heating element and to prevent the heating element from contacting the heating element of an adjacent suspension during an event such as a physical shock to the disk drive system.Type: ApplicationFiled: December 9, 2011Publication date: June 13, 2013Applicant: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Fu-Ying Huang, Lidu Huang, Yiduo Zhang
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Publication number: 20130142020Abstract: An apparatus according to one embodiment includes a near field transducer positioned towards a media-facing surface side, a primary waveguide for delivering light to the near field transducer, a secondary waveguide positioned near the primary waveguide and configured for receiving light from a light source and transferring at least some of the light received thereby to the primary waveguide, and a gap layer positioned between the primary waveguide and the secondary waveguide, wherein the secondary waveguide includes an oxide of at least one of Ta, Ti, Zr, and Nb alloyed with an oxide of at least one of Si and Al. Additional embodiments are also disclosed.Type: ApplicationFiled: December 5, 2011Publication date: June 6, 2013Applicant: Hitachi Global Storage Technologies Netherlands B.V.Inventor: Vijay P. S. Rawat
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Publication number: 20130141814Abstract: In one embodiment, a magnetic disk device includes a magnetic disk medium, at least one magnetic head having at least one of: a magnetic read element adapted for reading data from the magnetic disk medium and a magnetic write element adapted for writing data to the magnetic disk medium, and a heating element adapted for generating heat upon application of a voltage/current thereto, wherein the heating element is positioned on, near, or within the magnetic head, a drive mechanism for passing the magnetic disk medium over the at least one magnetic head, and a controller electrically coupled to the at least one magnetic head for controlling operation of the at least one magnetic head, wherein the controller is configured to retract the at least one magnetic head from a flying state above the magnetic disk medium and apply the voltage/current to the heating element while the magnetic head is retracted.Type: ApplicationFiled: December 2, 2011Publication date: June 6, 2013Applicant: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Yukimasa Okada, Katsumi Hoshino, Koji Kataoka, Takashi Wagatsuma
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Publication number: 20130141813Abstract: In one embodiment, a method includes forming a conducting material above an insulating film, applying a mask to portions of the conducting material in a shape of a TFC structure, removing exposed portions of the conducting material to form the TFC structure, depositing an insulating film above the TFC structure, and planarizing the insulating film to form a planar upper surface of the insulating film. In another embodiment, a magnetic head includes a TFC structure positioned between insulating films and a magnetic element positioned above the TFC structure, the TFC structure configured for providing localized thermal protrusion of the magnetic head on a media facing surface thereof, wherein an upper surface of an upper of the insulating films is planar, the magnetic element includes at least one of a main magnetic pole and a read sensor, and the TFC structure is configured for providing thermal protrusion of the magnetic element.Type: ApplicationFiled: December 2, 2011Publication date: June 6, 2013Applicant: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Takashi Wagatsuma, Yukimasa Okada, Ichiro Oodake, Atsushi Kato
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Publication number: 20130135764Abstract: A method, apparatus and a data storage device are provided for implementing data track pitch adjustment for data written on a recordable surface of a storage device under operational vibration conditions. An operational vibration disturbance spectrum is detected during a write operation and the data track pitch is selectively adjusted based on the detected operational vibration disturbance spectrum. The adjusted track pitch information is saved and used during a read operation.Type: ApplicationFiled: November 29, 2011Publication date: May 30, 2013Applicant: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Abhishek Dhanda, Toshiki Hirano, Tetsuo Semba, Zvonimir Z. Bandic
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Publication number: 20130135772Abstract: A method for manufacturing a magnetic sensor that includes depositing a plurality of mask layers, then forming a stripe height defining mask over the sensor layers. A first ion milling is performed just sufficiently to remove portions of the free layer that are not protected by the stripe height defining mask, the first ion milling being terminated at the non-magnetic barrier or spacer layer. A dielectric layer is then deposited, preferably by ion beam deposition. A second ion milling is then performed to remove portions of the pinned layer structure that are not protected by the mask, the free layer being protected during the second ion milling by the dielectric layer.Type: ApplicationFiled: November 29, 2011Publication date: May 30, 2013Applicant: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Yongchul Ahn, Xiaozhong Dang, Quang Le, Simon H. Liao
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Publication number: 20130128381Abstract: In one embodiment, a magnetic head includes a lower shield layer, a sensor stack positioned above the lower shield layer, the sensor stack including a free layer, a layered hard bias magnet positioned above the lower shield layer and on both sides of the sensor stack in a track width direction, and an upper shield layer positioned above the hard bias magnet and the sensor stack. The hard bias magnet includes a perpendicular anisotropy film positioned above the lower shield layer and aligned with both sides of the sensor stack in the track width direction, wherein the perpendicular anisotropy film directs magnetic fields in a direction perpendicular to planes of formation thereof, and an in-plane anisotropy film positioned above the perpendicular anisotropy film, wherein the in-plane anisotropy film directs magnetic fields in a direction of planes of formation thereof.Type: ApplicationFiled: November 21, 2011Publication date: May 23, 2013Applicant: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Susumu Okamura, Takahiro Ibusuki
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Publication number: 20130120876Abstract: A magnetic write head having a gap structure that improves write head performance. The write head includes a magnetic write pole and a magnetic shield that is separated from the trailing edge of the write pole by a non-magnetic trailing gap layer and is separated from the sides of the write pole by non-magnetic side gap layers. The trailing gap extends laterally beyond the side gap layers, and a convex bump is formed an edge of the magnetic shield at a location near the trailing end of the side gap layers.Type: ApplicationFiled: November 11, 2011Publication date: May 16, 2013Applicant: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Maki Maeda, Kimitoshi Eto, Hiromi Shiina, Kazue Kudo, Masafumi Mochizuki
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Publication number: 20130114165Abstract: A magnetic media for magnetic data recording having a plurality of magnetic grains protected by thin layers of graphitic carbon. The layers of graphitic carbon are formed in a manner similar to onion skins on an onion and can be constructed as single monatomic layers of carbon. The thin layers of graphitic carbon can be formed as layers of graphene or as fullerenes that either cover or partially encapsulate the magnetic gains. The layers of graphitic carbon provide excellent protection against corrosion and wear and greatly reduce magnetic spacing for improved magnetic performance.Type: ApplicationFiled: November 7, 2011Publication date: May 9, 2013Applicant: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Oleksandr Mosendz, Simone Pisana, Franck D. R. dit Rose, Dieter K. Weller
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Publication number: 20130100550Abstract: A method, apparatus, and system are provided for implementing magnetic defect classification using phase modulation for hard disk drives. A magnetic media readback signal of a hard disk drive is processed to identify predefined phase modulation (PM) characteristics to implement magnetic defect classification of magnetic media bump and pit defects.Type: ApplicationFiled: October 19, 2011Publication date: April 25, 2013Applicant: Hitachi Global Storage Technologies Netherlands B. V.Inventors: Richard Leo Galbraith, Weldon Mark Hanson, Martin Aureliano Hassner, Travis Roger Oenning, Satoshi Yamamoto
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Publication number: 20130094109Abstract: A magnetic media disk has a substrate; a recording magnetic media on the substrate; and an overcoat on the recording magnetic media, the overcoat comprising a Si-based layer on the recording magnetic media, and a Ti-based layer on the Si-based layer.Type: ApplicationFiled: October 12, 2011Publication date: April 18, 2013Applicant: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Bruno Marchon, Daryl J. Pocker, Franck D. Rose, Qi-Fan Xiao
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Publication number: 20130094108Abstract: A magnetic read sensor having improved magnetic performance and robustness. The magnetic sensor includes a magnetic free layer and a magnetic pinned layer structure. The magnetic pinned layer structure includes first and second magnetic layers separated from one another by a non-magnetic coupling layer. The second magnetic layer of the magnetic pinned layer structure includes a layer of CoFeBTa, which prevents the diffusion of atoms and also promotes a desired BCC crystalline grain growth. The magnetic free layer structure can also include such a CoFeBTa layer for further prevention of atomic diffusion and further promotion of a desired BCC grain growth.Type: ApplicationFiled: October 17, 2011Publication date: April 18, 2013Applicant: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Zheng Gao, Yingfan Xu, Hua Ai Zeng
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Publication number: 20130092654Abstract: A method for manufacturing a magnetic read sensor at very narrow track widths. The method uses an amorphous carbon mask layer to pattern the sensor by ion milling, rather than a mask constructed of a material such as photoresist or DURIMIDE® which can bend over during ion milling at very narrow track widths. By using the amorphous carbon layer as the masking layer, the trackwidth can be very small, while avoiding this bending over of the mask that has been experienced with prior art methods. In addition, the track-width can be further reduced by using a reactive ion etching to further reduce the width of the amorphous carbon mask prior to patterning the sensor. The method also allows extraneous portions of the side insulation layer and hard bias layer to be removed above the sensor by a light CMP process.Type: ApplicationFiled: October 18, 2011Publication date: April 18, 2013Applicant: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Hamid Balamane, Patrick M. Braganca, Jordan A. Katine, Jui-Lung Li, Yang Li, Kanaiyalal C. Patel, Neil L. Robertson, Samuel W. Yuan
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Publication number: 20130081937Abstract: A method for manufacturing a bit patterned magnetic media for magnetic data recording. The method includes patterning a topography that includes an array of raised regions separated by a recessed portion. The array can be patterned by micro-printing using a stamp that has raised islands. The raised regions can have a height of 1 to 5 nm as measured from the recessed region. A magnetic alloy and a non-magnetic segregant are then co-sputtered. The magnetic alloy preferentially grows over the raised portions and the non-magnetic segregant grow preferentially over the recessed region between the raised portions.Type: ApplicationFiled: February 9, 2012Publication date: April 4, 2013Applicant: Hitachi Global Storage Technologies Netherlands B.V.Inventor: Thomas R. Albrecht
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Publication number: 20130083420Abstract: A magnetic data storage system having a magnetic disk having burst patterns for providing a position error signal (PES) wherein each magnetic burst pattern is offset from an adjacent burst pattern by ¼ track pitch. All of the magnetic bits of the burst patterns can be unipolar magnetized, and the bits of each burst pattern can be aligned with one another in radial and circumferential direction. The magnetic media can be a bit patterned media wherein the magnetic bits of the burst patterns are magnetically isolated portions separated by non-magnetic spaces or non-magnetic material.Type: ApplicationFiled: September 29, 2011Publication date: April 4, 2013Applicant: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Thomas R. Albrecht, Toshiki Hirano, Tetsuo Semba, Xiaotian Sun