Patents by Inventor Muhammad Asif
Muhammad Asif has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 10997989Abstract: The present disclosure generally relates to data storage devices, and more specifically, to a magnetic media drive employing a magnetic recording head. A magnetic recording head comprises a main pole disposed between a leading shield and a trailing shield. A spin torque oscillator is disposed between the main pole and the trailing shield at a media facing surface. A hot seed bilayer is disposed between the spin torque oscillator and the trailing shield, where the hot seed bilayer is conformal with the spin torque oscillator. The hot seed bilayer comprises a first layer comprised of a high magnetic moment material disposed at the media facing surface and a second layer comprised of a low magnetic material recessed from the media facing surface.Type: GrantFiled: June 11, 2019Date of Patent: May 4, 2021Assignee: Western Digital Technologies, Inc.Inventors: Muhammad Asif Bashir, Alexander Goncharov, Petrus Antonius Van Der Heijden
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Patent number: 10997990Abstract: A magnetic recording head is disclosed having a main pole, a shield hot seed layer positioned at a first side of the main pole, a first material positioned at both a second side and a third side of the main pole, the first material connected to the main pole, a second material positioned adjacent to the first material on the second side and the third side of the main pole, the second material comprised of a spin torque layer, a third material positioned adjacent to the second material on the second side and the third side of the main pole, a fourth material positioned adjacent to the third material on the second side and the third side of the main pole and a side shield connected on an exterior side of the fourth material.Type: GrantFiled: June 24, 2020Date of Patent: May 4, 2021Assignee: WESTERN DIGITAL TECHNOLOGIES, INC.Inventors: Alexander Goncharov, Muhammad Asif Bashir, James Terrence Olson, Petrus Antonius Vanderheijden
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Publication number: 20210082457Abstract: The present disclosure generally relates to data storage devices, and more specifically, to a magnetic media drive employing a magnetic recording head. The head includes a main pole, a trailing shield, and a MAMR stack including at least one magnetic layer. The magnetic layer has a surface facing the main pole, and the surface has a first side at a media facing surface (MFS) and a second side opposite the first side. The length of the second side is substantially less than the length of the first side. By reducing the length of the second side, the area to be switched at a location recessed from the MFS is reduced as a current flowing from the main pole to the trailing shield or from the trailing shield to the main pole. With the reduced area of the magnetic layer, the overall switch time of the magnetic layer is decreased.Type: ApplicationFiled: November 30, 2020Publication date: March 18, 2021Inventors: Venkatesh CHEMBROLU, Muhammad ASIF BASHIR, Petrus Antonius VAN DER HEIJDEN, Terence LAM, Yaguang WEI
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Patent number: 10943616Abstract: A current-assisted magnetic recording write head has an electrically conductive layer in the write gap between the write pole and the trailing shield. Electrical circuitry directs current between the write pole and the trailing shield, through the conductive layer in the write gap. The current through the conductive layer generates an Ampere field substantially orthogonal to the magnetization in the write pole to assist magnetization switching of the write pole. The conductive layer is wider in the cross-track direction than the trailing edge of the write pole and may extend beyond the write pole side gaps so as to be in contact with both the side shields and the trailing shield. The conductive layer may have substantially the same along-the-track thickness across its width or it may have a thicker central region at the write pole trailing edge and thinner side regions.Type: GrantFiled: September 2, 2020Date of Patent: March 9, 2021Assignee: WESTERN DIGITAL TECHNOLOGIES, INC.Inventors: Muhammad Asif Bashir, Venkatesh Chembrolu, Alexander Goncharov, Petrus Antonius Van Der Heijden, Yingjian Chen
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Patent number: 10923145Abstract: A microwave-assisted magnetic recording (MAMR) write head has a spin-torque oscillator (STO) and a ferromagnetic compensation layer between the write pole and trailing shield. The compensation layer is separated from a free layer by a nonmagnetic barrier layer that prevents spin-polarized electrons from the free layer from reaching the compensation layer. The compensation layer may be located between the write pole and the free layer. Electrons become spin-polarized by the compensation layer and are reflected back from the write pole across a nonmagnetic spacer layer. This causes the magnetization of the compensation layer to flip and become antiparallel to the magnetization of the free layer. The compensation layer thus generates a DC offset field that compensates for the negative effect of the DC shunting field from the free layer.Type: GrantFiled: March 30, 2020Date of Patent: February 16, 2021Assignee: WESTERN DIGITAL TECHNOLOGIES, INC.Inventors: Alexander Goncharov, Muhammad Asif Bashir
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Publication number: 20210027808Abstract: A heat-assisted magnetic recording (HAMR) head for recording data in data tracks of a HAMR disk has a gas-bearing slider that supports a near-field transducer (NFT) and a main magnetic pole formed of two layers. The first main pole layer has a cross-track width at the slider's gas-bearing surface (GBS) that tapers down in the direction towards the NFT where the optical spot is formed. The second main pole layer is located away from the NFT and has a substantially wider cross-track width than the first main pole layer so as to provide sufficient magnetic field for writing. Layers of heat sink material are located on the sloped cross-track sides of the tapered first main pole layer to reduce the temperature and thus the likelihood of oxidation of the main pole layers.Type: ApplicationFiled: July 23, 2019Publication date: January 28, 2021Inventors: Takuya Matsumoto, Muhammad Asif Bashir, Hamid Balamane, Petrus VanDerHeijden, Barry Cushing Stipe
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Publication number: 20210021212Abstract: The invention relates to a method and an actuator system for determining and applying a voltage to a piezoelectric actuator (PEA) to achieve a given setpoint displacement. The method involves determining a relation dcal(V) between a PEA displacement measure (d) and voltage (V) and a relation ttcal(V) between transition time (tt) and voltage and combining the determined relations to calculate a relation d(tt) between the displacement measure and transition time during an initial calibration procedure. This relation is characteristic for the PEA, and by determining a new relation ttnew(V) after repeated biasing of the PEA, a compensated relation dc(V) can be calculated by substituting ttnew(V) in the calculated d(tt). The compensated relation dc(V) compensates for piezo creep effects due to the wear and can be used to determine the voltage to be applied directly, or be used in other compensation algorithms.Type: ApplicationFiled: March 17, 2019Publication date: January 21, 2021Inventors: Lars Henriksen, Tore Svortdal, Euan Barron, Muhammad Asif Raza Azhar, Thi Kim Trinh Tran, Nicolas Tallaron, Pierre Craen
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Patent number: 10891977Abstract: A microwave assisted magnetic recording (MAMR) write head includes a main pole and a trailing shield. A spin torque oscillator device is disposed between the main pole and the trailing shield. The spin torque oscillator device includes a free layer. A trailing shield hot seed layer is disposed between the spin torque oscillator device and the trailing shield. The trailing shield hot seed layer includes a magnetic material doped with a rare earth element. In certain embodiments, the trailing shield hot seed layer includes the rare earth element in an atomic percent content from about 2% to about 10% atomic percent. In certain embodiments, the trailing shield hot seed layer has an intrinsic damping from about 0.02 to about 0.2.Type: GrantFiled: July 8, 2020Date of Patent: January 12, 2021Assignee: WESTERN DIGITAL TECHNOLOGIES, INC.Inventors: Alexander Goncharov, Muhammad Asif Bashir, Petrus Antonius Van Der Heijden
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Publication number: 20200402532Abstract: A current-assisted magnetic recording write head has an electrically conductive layer in the write gap between the write pole and the trailing shield. Electrical circuitry directs current between the write pole and the trailing shield, through the conductive layer in the write gap. The current through the conductive layer generates an Ampere field substantially orthogonal to the magnetization in the write pole to assist magnetization switching of the write pole. The conductive layer is wider in the cross-track direction than the trailing edge of the write pole and may extend beyond the write pole side gaps so as to be in contact with both the side shields and the trailing shield. The conductive layer may have substantially the same along-the-track thickness across its width or it may have a thicker central region at the write pole trailing edge and thinner side regions.Type: ApplicationFiled: September 2, 2020Publication date: December 24, 2020Inventors: Muhammad ASIF BASHIR, Venkatesh CHEMBROLU, Alexander GONCHAROV, Petrus Antonius VAN DER HEIJDEN, Yingjian CHEN
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Patent number: 10872627Abstract: The present disclosure generally relates to data storage devices, and more specifically, to a magnetic media drive employing a magnetic recording head. The head includes a trailing shield, a main pole, an STO disposed between the trailing shield and the main pole, and a non-magnetic conductive structure adjacent to the main pole and in contact with the STO. The STO includes an FGL and an SPL, and the FGL is disposed between the main pole and the SPL. The FGL includes a side extending over the main pole and at least a portion of the non-magnetic conductive structure. With the FGL disposed proximate to the main pole and over at least a portion of the non-magnetic conductive structure, current crowding and disturbance from the trailing shield are minimized.Type: GrantFiled: August 12, 2020Date of Patent: December 22, 2020Assignee: WESTERN DIGITAL TECHNOLOGIES, INC.Inventors: Quang Le, Yongchul Ahn, Susumu Okamura, Zheng Gao, Alexander Goncharov, Muhammad Asif Bashir, Petrus Antonius Van Der Heijden, James Mac Freitag
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Patent number: 10872626Abstract: The present disclosure generally relates to data storage devices, and more specifically, to a magnetic media drive employing a magnetic recording head. The head includes a main pole, a trailing shield, and a MAMR stack including at least one magnetic layer. The magnetic layer has a surface facing the main pole, and the surface has a first side at a media facing surface (MFS) and a second side opposite the first side. The length of the second side is substantially less than the length of the first side. By reducing the length of the second side, the area to be switched at a location recessed from the MFS is reduced as a current flowing from the main pole to the trailing shield or from the trailing shield to the main pole. With the reduced area of the magnetic layer, the overall switch time of the magnetic layer is decreased.Type: GrantFiled: March 5, 2019Date of Patent: December 22, 2020Assignee: WESTERN DIGITAL TECHNOLOGIES, INC.Inventors: Venkatesh Chembrolu, Muhammad Asif Bashir, Petrus Antonius Van Der Heijden, Terence Lam, Yaguang Wei
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Patent number: 10861485Abstract: Embodiments of the present disclosure generally relate to data storage devices, and more specifically, to storage devices employing an energy-assisted magnetic recording write head. The write head may comprise a main pole, a trailing shield, a conducting gap disposed between the main pole and the trailing shield, and one or more current blockers. The conducting gap may be conformal with the main pole. The one or more current blockers may be configured to direct the current from the main pole to the trailing shield through the conducting gap. The one or more current blockers may be further configured to recess the conducting gap away from the media facing surface. The one or more current blockers may be configured to direct the current away from a media facing surface of the write head.Type: GrantFiled: August 17, 2020Date of Patent: December 8, 2020Assignee: WESTERN DIGITAL TECHNOLOGIES, INC.Inventors: Muhammad Asif Bashir, Yaguang Wei, Petrus Antonius Van Der Heijden, Xinjiang Shen, Terence Lam, Zhigang Bai, Youfeng Zheng, Changqing Shi, Michael Kuok San Ho, Jian-Gang Zhu, Lijie Guan, Venkatesh Chembrolu
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Publication number: 20200381011Abstract: Embodiments of the present disclosure generally relate to data storage devices, and more specifically, to storage devices employing an energy-assisted magnetic recording write head. The write head may comprise a main pole, a trailing shield, a conducting gap disposed between the main pole and the trailing shield, and one or more current blockers. The conducting gap may be conformal with the main pole. The one or more current blockers may be configured to direct the current from the main pole to the trailing shield through the conducting gap. The one or more current blockers may be further configured to recess the conducting gap away from the media facing surface. The one or more current blockers may be configured to direct the current away from a media facing surface of the write head.Type: ApplicationFiled: August 17, 2020Publication date: December 3, 2020Inventors: Muhammad ASIF BASHIR, Yaguang WEI, Petrus Antonius VAN DER HEIJDEN, Xinjiang SHEN, Terence LAM, Zhigang BAI, Youfeng ZHENG, Changqing SHI, Michael Kuok San HO, Jian-Gang ZHU, Lijie GUAN, Venkatesh CHEMBROLU
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Publication number: 20200372929Abstract: The present disclosure generally relates to data storage devices, and more specifically, to a magnetic media drive employing a magnetic recording head. The head includes a trailing shield, a main pole, an STO disposed between the trailing shield and the main pole, and a non-magnetic conductive structure adjacent to the main pole and in contact with the STO. The STO includes an FGL and an SPL, and the FGL is disposed between the main pole and the SPL. The FGL includes a side extending over the main pole and at least a portion of the non-magnetic conductive structure. With the FGL disposed proximate to the main pole and over at least a portion of the non-magnetic conductive structure, current crowding and disturbance from the trailing shield are minimized.Type: ApplicationFiled: August 12, 2020Publication date: November 26, 2020Inventors: Quang LE, Yongchul AHN, Susumu OKAMURA, Zheng GAO, Alexander GONCHAROV, Muhammad ASIF BASHIR, Petrus Antonius VAN DER HEIJDEN, James Mac FREITAG
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Patent number: 10839832Abstract: A microwave assisted magnetic recording (MAMR) write head includes a main pole and a trailing shield. A spin torque oscillator device is disposed between the main pole and the trailing shield. The spin torque oscillator device includes a free layer. A trailing shield hot seed layer is disposed between the spin torque oscillator device and the trailing shield. The trailing shield hot seed layer includes a magnetic material doped with a rare earth element. In certain embodiments, the trailing shield hot seed layer includes the rare earth element in an atomic percent content from about 2% to about 10% atomic percent. In certain embodiments, the trailing shield hot seed layer has an intrinsic damping from about 0.02 to about 0.2.Type: GrantFiled: December 30, 2019Date of Patent: November 17, 2020Assignee: WESTERN DIGITAL TECHNOLOGIES, INC.Inventors: Alexander Goncharov, Muhammad Asif Bashir, Petrus Antonius Van Der Heijden
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Patent number: 10839844Abstract: A current-assisted magnetic recording write head has an electrically conductive layer in the write gap between the write pole and the trailing shield. Electrical circuitry directs current between the write pole and the trailing shield, through the conductive layer in the write gap. The current through the conductive layer generates an Ampere field substantially orthogonal to the magnetization in the write pole to assist magnetization switching of the write pole. The conductive layer is wider in the cross-track direction than the trailing edge of the write pole and may extend beyond the write pole side gaps so as to be in contact with both the side shields and the trailing shield. The conductive layer may have substantially the same along-the-track thickness across its width or it may have a thicker central region at the write pole trailing edge and thinner side regions.Type: GrantFiled: March 27, 2019Date of Patent: November 17, 2020Assignee: WESTERN DIGITAL TECHNOLOGIES, INC.Inventors: Muhammad Asif Bashir, Venkatesh Chembrolu, Alexander Goncharov, Petrus Antonius Van Der Heijden, Yingjian Chen
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Publication number: 20200327902Abstract: A magnetic recording head is disclosed having a main pole, a shield hot seed layer positioned at a first side of the main pole, a first material positioned at both a second side and a third side of the main pole, the first material connected to the main pole, a second material positioned adjacent to the first material on the second side and the third side of the main pole, the second material comprised of a spin torque layer, a third material positioned adjacent to the second material on the second side and the third side of the main pole, a fourth material positioned adjacent to the third material on the second side and the third side of the main pole and a side shield connected on an exterior side of the fourth material.Type: ApplicationFiled: June 24, 2020Publication date: October 15, 2020Inventors: Alexander GONCHAROV, Muhammad ASIF BASHIR, James Terrence OLSON, Petrus Antonius VANDERHEIJDEN
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Publication number: 20200294536Abstract: Disclosed herein are magnetic write heads and methods of designing them, and data storage devices comprising such write heads. A magnetic write head having leading and trailing sides comprises an air-bearing surface (ABS), a main pole between the leading and trailing sides, a first return pole between the main pole and the leading side, at least one optical near-field generator between the first return pole and the main pole, and a second return pole between the main pole and the trailing side. The main pole comprises a first tapered portion comprising a leading-side edge perpendicular to the ABS, a first trailing-side edge at a first angle to the ABS, and a second trailing-side edge recessed from the ABS and at a second angle to the ABS. The second return pole comprises a second tapered portion adjacent to the ABS and extending toward the main pole.Type: ApplicationFiled: June 3, 2020Publication date: September 17, 2020Applicant: Western Digital Technologies, Inc.Inventors: Muhammad Asif BASHIR, Petrus Antonius VAN DER HEIJDEN, Alexander GONCHAROV, Barry STIPE
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Patent number: 10777219Abstract: Embodiments of the present disclosure generally relate to data storage devices, and more specifically, to storage devices employing an energy-assisted magnetic recording write head. The write head may comprise a main pole, a trailing shield, a conducting gap disposed between the main pole and the trailing shield, and one or more current blockers. The conducting gap may be conformal with the main pole. The one or more current blockers may be configured to direct the current from the main pole to the trailing shield through the conducting gap. The one or more current blockers may be further configured to recess the conducting gap away from the media facing surface. The one or more current blockers may be configured to direct the current away from a media facing surface of the write head.Type: GrantFiled: June 24, 2019Date of Patent: September 15, 2020Assignee: Western Digital Technologies, Inc.Inventors: Muhammad Asif Bashir, Yaguang Wei, Petrus Antonius Van Der Heijden, Xinjiang Shen, Terence Lam, Zhigang Bai, Youfeng Zheng, Changqing Shi, Michael Kuok San Ho, Jian-Gang Zhu, Lijie Guan, Venkatesh Chembrolu
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Patent number: 10778663Abstract: Aspects of the disclosure relates to managed access to content and/or services. In certain aspects, tokens or other artifacts can be utilized for authentication and authorization.Type: GrantFiled: March 18, 2014Date of Patent: September 15, 2020Assignee: Cox Communications, Inc.Inventors: Keith Alan Rothschild, Edgar V. Shrum, Muhammad Asif Raza, Richard M. Thomas