Patents by Inventor Venkatesh Chembrolu
Venkatesh Chembrolu 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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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: 20200381012Abstract: A magnetic head includes a main pole configured to serve as a first electrode, an upper pole containing a trailing magnetic shield configured to a serve as a second electrode, and a record element located in a trailing gap between the main pole and the trailing magnetic shield. The record element includes an electrically conductive, non-magnetic material portion which is not part of a spin torque oscillator stack. The main pole and the trailing magnetic shield are electrically shorted by the record element across the trailing gap between the main pole and the trailing magnetic shield such that an electrically conductive path is present between the main pole and the trailing magnetic shield through the record element.Type: ApplicationFiled: August 20, 2020Publication date: December 3, 2020Inventors: Venkatesh CHEMBROLU, Zhigang BAI, Yaguang WEI, Anna ZHENG, Supradeep NARAYANA, Suping SONG, Terence LAM, Michael Kouk San HO, Changqing SHI, Lijie GUAN, Jian-Gang ZHU
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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: 20200327900Abstract: A magnetic recording write head has an electrically-conductive structure in the write gap between the write pole and the trailing shield and electrical circuitry for directing current through the write gap. The current through the electrically-conductive structure generates a circular Ampere field which, at the disk-facing end of the write pole, is substantially parallel to the disk-facing end of the write pole. The electrically-conductive structure in the write gap may be a STO or an electrically-conductive layer that is not part of a STO. The current direction through the electrically-conductive structure in the write gap is selected so that the generated Ampere field at the write pole end is in substantially the same direction as the magnetization direction of the write head side shields, which has been discovered to result in minimization of cross-track interference.Type: ApplicationFiled: June 24, 2020Publication date: October 15, 2020Inventors: Zhigang BAI, Alexander TARATORIN, Anna ZHENG, Venkatesh CHEMBROLU, Supradeep NARAYANA, Suping SONG, Yaguang WEI, Terence LAM, Michael Kuok San HO, Changqing SHI, Lijie GUAN
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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: 10699734Abstract: A magnetic recording write head has an electrically-conductive structure in the write gap between the write pole and the trailing shield and electrical circuitry for directing current through the write gap. The current through the electrically-conductive structure generates a circular Ampere field which, at the disk-facing end of the write pole, is substantially parallel to the disk-facing end of the write pole. The electrically-conductive structure in the write gap may be a STO or an electrically-conductive layer that is not part of a STO. The current direction through the electrically-conductive structure in the write gap is selected so that the generated Ampere field at the write pole end is in substantially the same direction as the magnetization direction of the write head side shields, which has been discovered to result in minimization of cross-track interference.Type: GrantFiled: February 15, 2019Date of Patent: June 30, 2020Assignee: WESTERN DIGITAL TECHNOLOGIES, INC.Inventors: Zhigang Bai, Alexander Taratorin, Anna Zheng, Venkatesh Chembrolu, Supradeep Narayana, Suping Song, Yaguang Wei, Terence Lam, Michael Kuok San Ho, Changqing Shi, Lijie Guan
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Patent number: 10679650Abstract: 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 from the write pole, through the conductive layer, to the trailing shield. 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 write head's magnetic throat height (THm) is substantially the thickness of the trailing shield at the write gap, while the write head's electrical throat height (THe) is substantially the height of the conductive layer in the write gap. In embodiments of this invention, the signal-to-noise ratio (SNR) of the readback signal and the soft error rate (SER) of the recorded data can be improved with a write gap structure wherein THe is greater than THm.Type: GrantFiled: February 15, 2019Date of Patent: June 9, 2020Assignee: WESTERN DIGITAL TECHNOLOGIES, INC.Inventors: Zhigang Bai, Venkatesh Chembrolu, Yaguang Wei, Terence Lam, Michael Kuok San Ho, Lijie Guan, Suping Song, Supradeep Narayana
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Publication number: 20200005815Abstract: 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 from the write pole, through the conductive layer, to the trailing shield. 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 write head's magnetic throat height (THm) is substantially the thickness of the trailing shield at the write gap, while the write head's electrical throat height (THe) is substantially the height of the conductive layer in the write gap. In embodiments of this invention, the signal-to-noise ratio (SNR) of the readback signal and the soft error rate (SER) of the recorded data can be improved with a write gap structure wherein THe is greater than THm.Type: ApplicationFiled: February 15, 2019Publication date: January 2, 2020Inventors: Zhigang BAI, Venkatesh CHEMBROLU, Yaguang WEI, Terence LAM, Michael Kuok San HO, Lijie GUAN, Suping SONG, Supradeep NARAYANA
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Publication number: 20190318760Abstract: 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: March 5, 2019Publication date: October 17, 2019Inventors: Venkatesh CHEMBROLU, Muhammad ASIF BASHIR, Petrus Antonius VAN DER HEIJDEN, Terence LAM, Yaguang WEI
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Publication number: 20190267029Abstract: A magnetic recording write head has an electrically-conductive structure in the write gap between the write pole and the trailing shield and electrical circuitry for directing current through the write gap. The current through the electrically-conductive structure generates a circular Ampere field which, at the disk-facing end of the write pole, is substantially parallel to the disk-facing end of the write pole. The electrically-conductive structure in the write gap may be a STO or an electrically-conductive layer that is not part of a STO. The current direction through the electrically-conductive structure in the write gap is selected so that the generated Ampere field at the write pole end is in substantially the same direction as the magnetization direction of the write head side shields, which has been discovered to result in minimization of cross-track interference.Type: ApplicationFiled: February 15, 2019Publication date: August 29, 2019Inventors: Zhigang BAI, Alexander TARATORIN, Anna ZHENG, Venkatesh CHEMBROLU, Supradeep NARAYANA, Suping SONG, Yaguang WEI, Terence LAM, Michael Kuok San HO, Changqing SHI, Lijie GUAN
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Publication number: 20180012627Abstract: A method may include causing a write head of a magnetic data storage drive to write a first portion of data to a magnetic data storage device of the magnetic data storage drive based at least in part on a first value of at least one parameter of a write current. The method may include updating a value of a write counter and determining whether the value of the write counter is greater than or equal to a threshold write count. The method may also include adjusting the at least one parameter of the write current to a second, different value. The method may further include causing the write head to write a second portion of data to the magnetic data storage device based at least in part on the second value of the at least one parameter of the write current.Type: ApplicationFiled: July 7, 2016Publication date: January 11, 2018Inventors: Mark Hutcheson Burkhardt, Venkatesh Chembrolu, Zhaohui Chen, Quan-Chiu Lam, Supradeep Narayana
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Publication number: 20150380017Abstract: The embodiments of the present invention relate to a magnetic write head and a method for forming the magnetic write head. The magnetic write head includes a partially laminated main pole that has a magnetic layer that is recessed from a media facing surface, a nonmagnetic spacer layer disposed on and adjacent to the magnetic layer and a laminated stack disposed on at least a portion of the nonmagnetic layer. The nonmagnetic spacer layer has a first end at the media facing surface and a second end at a distance from the media facing surface and the laminated stack has a first end at the media facing surface and as second end at a distance from the media facing surface.Type: ApplicationFiled: September 4, 2015Publication date: December 31, 2015Inventors: Venkatesh CHEMBROLU, Wen-Chien David HSIAO, Alexander M. ZELTSER
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Patent number: 9129619Abstract: The embodiments of the present invention relate to a magnetic write head and a method for forming the magnetic write head. The magnetic write head includes a partially laminated main pole that has a magnetic layer that is recessed from a media facing surface, a nonmagnetic spacer layer disposed on and adjacent to the magnetic layer and a laminated stack disposed on at least a portion of the nonmagnetic layer. The nonmagnetic spacer layer has a first end at the media facing surface and a second end at a distance from the media facing surface and the laminated stack has a first end at the media facing surface and as second end at a distance from the media facing surface.Type: GrantFiled: January 27, 2014Date of Patent: September 8, 2015Assignee: HGST NETHERLANDS B.V.Inventors: Venkatesh Chembrolu, Wen-Chien David Hsiao, Alexander M. Zeltser
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Patent number: 9099110Abstract: Embodiments disclosed herein generally relate to a magnetic write head. The magnetic write head includes a write pole, a shield and a first coil disposed around the write pole. The magnetic write head further includes a magnetic circuit and the magnetic circuit includes a loop of magnetic material and a second coil disposed around the loop of magnetic material. The magnetic circuit magnetically resets the shield to improve far track interference.Type: GrantFiled: July 15, 2014Date of Patent: August 4, 2015Assignee: HGST NETHERLANDS, B.V.Inventors: Venkatesh Chembrolu, Wen-Chien David Hsiao, Quan-Chiu Harry Lam, Supradeep Narayana
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Publication number: 20150213814Abstract: The embodiments of the present invention relate to a magnetic write head and a method for forming the magnetic write head. The magnetic write head includes a partially laminated main pole that has a magnetic layer that is recessed from a media facing surface, a nonmagnetic spacer layer disposed on and adjacent to the magnetic layer and a laminated stack disposed on at least a portion of the nonmagnetic layer. The nonmagnetic spacer layer has a first end at the media facing surface and a second end at a distance from the media facing surface and the laminated stack has a first end at the media facing surface and as second end at a distance from the media facing surface.Type: ApplicationFiled: January 27, 2014Publication date: July 30, 2015Applicant: HGST NETHERLANDS B.V.Inventors: Venkatesh CHEMBROLU, Wen-Chien David HSIAO, Alexander M. ZELTSER
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MAGNETIC RECORDING HEAD HAVING THERMAL FLY HEIGHT CONTROL ELEMENT WITH NEAR ZERO MAGNETOMOTIVE FORCE
Publication number: 20150213820Abstract: A magnetic recording head with thermal fly height control, wherein the heating element is configured to eliminate magnetic field effects on the writing pole, which would cause otherwise cause non-symmetric writing or pole erasure. Non-symmetric writing is a phenomenon wherein magnetic writing favors one direction over another, thereby causing a timing shift in recorded data. The pole erasure is a phenomenon wherein the erasure would occur even without write current. The heating element can be formed as a plurality of electrically conductive layers separated by a non-magnetic, electrically insulating layer such as alumina. The electrically conductive layers are configured so that current flows in opposite directions through each of the electrically conductive layers such that any magnetic field generated by the current flow through one electrically conductive layer is cancelled out by a magnetic field from another electrically conductive layer.Type: ApplicationFiled: January 28, 2014Publication date: July 30, 2015Applicant: HGST NETHERLANDS B.V.Inventors: Venkatesh Chembrolu, Wen-Chien D. Hsiao, Edward H.P. Lee, Xinjiang Shen -
Patent number: 9036299Abstract: Approaches to improving hard disk drive far track interference problems include utilizing a wrap-around shield having recessed high magnetic moment layer(s). Embodiments include tapering the high-moment portion away from the air bearing surface (ABS) in the cross-track direction away from the write pole, thereby reducing exposure of high moment layers at the ABS to reduce the risk of unwanted track erasure away from the main pole. Embodiments include positioning the high magnetic moment layers in their entirety away from the ABS, such as with a laminate structure of high magnetic moment and low magnetic moment materials laid down in a direction away from the pole tip trailing edge.Type: GrantFiled: July 24, 2013Date of Patent: May 19, 2015Assignee: HGST Netherlands B.V.Inventor: Venkatesh Chembrolu
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Publication number: 20150029615Abstract: Approaches to improving hard disk drive far track interference problems include utilizing a wrap-around shield having recessed high magnetic moment layer(s). Embodiments include tapering the high-moment portion away from the air bearing surface (ABS) in the cross-track direction away from the write pole, thereby reducing exposure of high moment layers at the ABS to reduce the risk of unwanted track erasure away from the main pole. Embodiments include positioning the high magnetic moment layers in their entirety away from the ABS, such as with a laminate structure of high magnetic moment and low magnetic moment materials laid down in a direction away from the pole tip trailing edge.Type: ApplicationFiled: July 24, 2013Publication date: January 29, 2015Applicant: HGST Netherlands B.V.Inventor: Venkatesh Chembrolu