Patents by Inventor Ullal Vasant Nayak
Ullal Vasant Nayak 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: 7312941Abstract: A Hard Disk Drive (HDD) includes a write-inhibit signal that is generated by a head-disk interaction sensor during a write process that is integrated with a suspension of the HDD when fly-height modulation of the slider is detected during a write process. The suspension load beam includes a dimple and a laminated flexure. The laminated flexure includes a surface that is adapted to receive a slider and a surface that is adapted to contact the dimple. The head-disk interaction sensor is fabricated as part of the laminations of the flexure. The head-disk interaction sensor can be an accelerometer that senses an acceleration of the flexure when the slider contacts the disk of the disk drive and/or a pressure sensor that senses a pressure between the flexure and the dimple when the slider contacts the disk. A write-inhibit circuit is responsive to the sensor signal by inhibiting the write process.Type: GrantFiled: September 17, 2003Date of Patent: December 25, 2007Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Toshiki Hirano, Ullal Vasant Nayak, Qinghua Zeng
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Patent number: 7230800Abstract: A micro-fabricated chip having a stationary structure and a movable structure with a gimbal structure allows pitch and roll motion of the movable structure with respect to the stationary structure. One embodiment of the gimbal structure includes a dimple surface making a rolling-type contact with the stationary structure, and a center bar and a plurality of bar members. An alternative embodiment of the gimbal structure includes a plurality of torsion bar members. Another alternative embodiment of the gimbal structure includes a plurality of flexible members. The micro-fabricated chip can be a passive chip structure or, alternatively, a microactuator having a movable structure that moves in a rotational direction or a translational direction with respect to the stationary structure.Type: GrantFiled: July 24, 2003Date of Patent: June 12, 2007Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Toshiki Hirano, Ullal Vasant Nayak, Henry Hung Yang
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Apparatus for burnishing small asperities and cleaning loose particles from magnetic recording media
Patent number: 7164557Abstract: An air bearing burnish slider burnishes very small asperities and cleans the loose particles that adhere to the magnetic recording media. The slider applies a controllable contact force to effectively burnish disk asperities or partially attached particles. In addition, the slider cleans the loose particles effectively while flying in a stable fashion. In a low pitch design, diagonal rails push particles away from the disk surface and trailing edge pads contact the disk at lower linear velocities. Rail pads retain loose contamination and debris in their pockets and burnish asperities. Another design provides a milder burnish force and flies in a high pitch configuration. The trailing edge pads provide stable contacts and the rails help in sweeping away debris. In both designs, the contact forces can be controlled by adjusting linear velocities. A step taper at the leading edge provides a pitch-producing lift force.Type: GrantFiled: February 23, 2004Date of Patent: January 16, 2007Assignee: Hitachi Global Storage Technologies Netherlands BVInventors: Parul Agrawal, Hang Fai Ngo, Charles Lee, Li-Chung Lee, Ullal Vasant Nayak, Stephen Olson, Robert N. Payne, Christopher Ramm -
Patent number: 7002768Abstract: A disk drive having a layer of lubricant on a disk surface, where an undesirable lubricant layer thickness modulation is reduced by varying ?/f during operation of the disk drive. Here ? is the angular velocity of the disk and f is a resonant frequency of a head assembly containing the head. In this manner, the amplitude of the lubricant thickness modulation is decreased, improving disk drive performance. The ratio ?/f is preferably varied by varying the disk angular velocity ?.Type: GrantFiled: October 9, 2003Date of Patent: February 21, 2006Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Bruno Marchon, Qing Dai, Ferdinand Hendriks, Ullal Vasant Nayak
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Patent number: 6958871Abstract: A write-inhibit signal is generated by a head-disk interaction sensor during a write process that is integrated with a suspension of a hard disk drive (HDD) when fly-height modulation of the slider is detected during a write process The suspension load beam includes a dimple and a laminated flexure. The laminated flexure includes a surface that is adapted to receive a slider and a surface that is adapted to contact the dimple. The head-disk interaction sensor is fabricated as part of the laminations of the flexure. The head-disk interaction sensor can be an accelerometer that senses an acceleration of the flexure when the slider contacts the disk of the disk drive and/or a pressure sensor that senses a pressure between the flexure and the dimple when the slider contacts the disk. A write-inhibit circuit is responsive to the sensor signal by inhibiting the write process.Type: GrantFiled: September 17, 2003Date of Patent: October 25, 2005Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Toshiki Hirano, Ullal Vasant Nayak, Qinghua Zeng
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Patent number: 6947242Abstract: Disclosed is an apparatus and method for dynamic fly height and roll adjustment of a physical asperity sensor (PAS) head. The PAS head is used to test disk asperity heights and mechanical interference (commonly known as glide height and take off height). The PAS may be adjusted through a pivoting device such as a joystick coupled through one or more actuators to the pivoting device by actuator arms. In one embodiment, the actuator is a piezoelectric motor. The PAS head may utilize a detector to indicate the distance of the disk asperity from the PAS head. The method comprises receiving the signal and in response, operating the actuators to adjust the position of the pivoting device to obtain a selected positioning of either the fly height or the roll of the PAS.Type: GrantFiled: April 16, 2002Date of Patent: September 20, 2005Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Hong S. Seing, Bob C. Robinson, Ullal Vasant Nayak, Carl Robert Mendel, Wesley LeRoy Hillman, Tony Mello, Steven Harry Voss
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Patent number: 6767584Abstract: A method for texturing substrate surfaces and a substrate product, such as for computer disk drives. Microbump textured substrates are produced having a Rp value of about 20-200 Å and a ratio of Rmax:Rp of about 1.4 or less. In an exemplary embodiment, a microbump textured substrate is produced having colloidal particles on a surface thereof at a density of at least about 25 particles per 25 &mgr;m2, wherein the surface topography includes a Rp value of about 20-200 Å, a micro-roughness Rq of about 10 Å or less, and a ratio of Rmax:Rp of about 1.4 or less. An exemplary method includes first providing a substrate surface having a surface micro-roughness Rq of about 10 Å or less and depositing colloidal particles on the surface to provide a Rp value of about 20-200 Å and a ratio of Rmax:Rp of about 1.4 or less. In a further exemplary embodiment, the method increases the micro-roughness Rq, but to a value that is still less than about 10 Å with Rmax:Rp still of about 1.Type: GrantFiled: May 13, 2002Date of Patent: July 27, 2004Assignee: International Business Machines CorporationInventors: James A. Hagan, Ullal Vasant Nayak, Janice Blue Ostrom, Douglas Howard Piltingsrud, Douglas A. Kuchta
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Publication number: 20030211365Abstract: A method for texturing substrate surfaces and a substrate product, such as for computer disk drives. Microbump textured substrates are produced having a Rp value of about 20-200 Å and a ratio of Rmax:Rp of about 1.4 or less. In an exemplary embodiment, a microbump textured substrate is produced having colloidal particles on a surface thereof at a density of at least about 25 particles per 25 &mgr;m2, wherein the surface topography includes a Rp value of about 20-200 Å, a micro-roughness Rq of about 10 Å or less, and a ratio of Rmax:Rp of about 1.4 or less. An exemplary method includes first providing a substrate surface having a surface micro-roughness Rq of about 10 Å or less and depositing colloidal particles on the surface to provide a Rp value of about 20-200 Å and a ratio of Rmax:Rp of about 1.4 or less. In a further exemplary embodiment, the method increases the micro-roughness Rq, but to a value that is still less than about 10 Å with Rmax:Rp still of about 1.Type: ApplicationFiled: May 13, 2002Publication date: November 13, 2003Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: James A. Hagan, Ullal Vasant Nayak, Janice Blue Ostrom, Douglas Howard Piltingsrud, Douglas A. Kuchta
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Publication number: 20030193734Abstract: Disclosed is an apparatus and method for dynamic fly height and roll adjustment of a physical asperity sensor (PAS) head. The PAS head is used to test disk asperity heights and mechanical interference (commonly known as glide height and take off height). The PAS may be adjusted through a pivoting device such as a joystick coupled through one or more actuators to the pivoting device by actuator arms. In one embodiment, the actuator is a piezoelectric motor. The PAS head may utilize a detector to indicate the distance of the disk asperity from the PAS head. The method comprises receiving the signal and in response, operating the actuators to adjust the position of the pivoting device to obtain a selected positioning of either the fly height or the roll of the PAS.Type: ApplicationFiled: April 16, 2002Publication date: October 16, 2003Inventors: Hong S. Seing, Bob C. Robinson, Ullal Vasant Nayak, Carl Robert Mendel, Wesley LeRoy Hillman, Tony Mello, Steven Harry Voss
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Patent number: 6497021Abstract: A method and apparatus for providing a low cost contact burnish slider is disclosed that can remain in contact or at the initial low flying heights even as the pad surfaces and leading edges wear. The burnish slider includes a body having a leading edge and a trailing edge and an air bearing surface being configured at the leading edge of the body to cut disk asperities as the slider flies and configured away from the leading edge to maintain a flying attitude wherein the leading edge is near the data recording surface and to provide restoring forces to maintain the flying attitude. The air bearing surface may include a front pad proximal to the leading edge and a rear pad distal to the leading edge. Alternatively, the air bearing surface may include two front pads proximal to the leading edge on opposite sides of the body and two rear pads distal to the leading edge and disposed on opposite sides of the body. The front and rear pad(s) extends substantially across the body of the slider.Type: GrantFiled: January 14, 1999Date of Patent: December 24, 2002Assignee: International Business Machines CorporationInventors: Francis Chee-Shuen Lee, Michael Lee McGhee, Salvador Navarro, Ullal Vasant Nayak, Hang Fai Ngo
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Patent number: 6493185Abstract: The present invention provides an optimized pad design for a slider that minimizes the effect of mask alignment tolerances to allow for a more consistent N58 pad area and hence a more controllable burnish rate of the protruding pad. The protruding pad includes a first portion and a second portion formed by processing material to form the first and second portion wherein at least a quantity of the first portion comprises a first material type and the second portion comprises a second material type, the protruding pad further comprising a boundary interface separating the first material type from the second material type, the boundary interface having a position on the first portion that is dependent upon an alignment tolerance for the processing and that defines a surface area for the material of the second type, wherein the surface area of the material of the second type is negligibly affected by the position of the boundary interface.Type: GrantFiled: October 13, 2000Date of Patent: December 10, 2002Assignee: International Business Machines CorporationInventors: Lee K. Dorius, Ullal Vasant Nayak, Robert Nolan Payne
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Publication number: 20020162204Abstract: A method and apparatus for providing a low cost contact burnish slider is disclosed that can remain in contact or at the initial low flying heights even as the pad surfaces and leading edges wear. The burnish slider includes a body having a leading edge and a trailing edge and an air bearing surface being configured at the leading edge of the body to cut disk asperities as the slider flies and configured away from the leading edge to maintain a flying attitude wherein the leading edge is near the data recording surface and to provide restoring forces to maintain the flying attitude. The air bearing surface may include a front pad proximal to the leading edge and a rear pad distal to the leading edge. Alternatively, the air bearing surface may include two front pads proximal to the leading edge on opposite sides of the body and two rear pads distal to the leading edge and disposed on opposite sides of the body. The front and rear pad(s) extends substantially across the body of the slider.Type: ApplicationFiled: January 14, 1999Publication date: November 7, 2002Inventors: FRANCIS CHEE-SHUEN LEE, MICHAEL LEE MCGHEE, SALVADOR NAVARRO, ULLAL VASANT NAYAK, HANG FAI NGO
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Patent number: 6407880Abstract: A computer system hard disk drive contains magnetic heads for reading data to and writing data from storage media disks. The heads are coupled to an electrical source that thermally excites the heads during non-operation of the disk drive in order to raise the temperature of the heads. The temperature increase induces a mechanism such as a local, low humidity barrier at each of the heads. When the disk drive is stored in harsh environmental atmospheres, such as high temperatures and high humidity, the mechanism or low humidity barrier is sufficient to overcome the ambient conditions and reduce environmental corrosion of the heads.Type: GrantFiled: March 28, 2000Date of Patent: June 18, 2002Assignee: International Business Machines CorporationInventors: Donald R. Gillis, Kris Schouterden, Ullal Vasant Nayak, Reinhard F. Wolter
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Patent number: 6125005Abstract: An air bearing slider for supporting a magnetic read/write head on a moving disk includes at least one front force carrying pad located in front of a suspension pivot point of an air bearing slider, at least one rear force-carrying pad located behind the suspension pivot point of the air bearing slider, and a trailing-edge pad having a magnetic read/write head embedded in a rear portion of the trailing-edge pad. Each front force-carrying pad carries a front air bearing force that is generated by a relative motion between a surface of the disk and the slider when the surface of the disk has a predetermined disk velocity with respect to the slider. Each rear force-carrying pad carries a rear air bearing force that is generated by the relative motion between the surface of the disk and the slider. The trailing edge pad carries substantially no air bearing force.Type: GrantFiled: December 30, 1997Date of Patent: September 26, 2000Assignee: International Business Machines CorporationInventors: Francis Chee-Shuen Lee, Robert Nolan Payne, Ullal Vasant Nayak
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Patent number: 5689057Abstract: Crater shaped bumps are made on a calibration disk which can be used for calibrating a PZT slider, the PZT slider in turn being used for detecting predetermined asperities on a production run magnetic disk. The crater shaped bumps emulate predetermined asperities of production run magnetic disks and especially asperities which are undesirable and would cause the production run disk to be discarded after testing by the PZT slider. Crater shaped bumps which emulate undesirable asperities on current production runs of magnetic disks have a diameter in the range of 10 to 25 .mu.m and a peripheral ridge with a height h.sub.r above a nominal surface of the calibration disk in the range of 75 to 120 nm. Close tolerance crater shaped bumps with this configuration can be made by impinging two or more pulses of laser energy on the same location of a calibration disk. By increasing the number of pulses the height of the peripheral ridge progressively increases.Type: GrantFiled: February 27, 1996Date of Patent: November 18, 1997Assignee: International Business Machines CorporationInventors: Peter Michael Baumgart, Karl A. Flechsig, Michael Franklin Lee, Wing P. Leung, Ullal Vasant Nayak, Thao Anh Nguyen, Timothy Christopher O'Sullivan, Andrew Ching Tam