Patents by Inventor Li-Ping Wang
Li-Ping Wang 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: 6749904Abstract: High areal storage density, patterned magnetic media comprising a patterned plurality of at least partially crystalline, ferromagnetic particles or grains are provided by means of a simple, economical process wherein a non-magnetic substrate is provided with a layer of an amorphous, paramagnetic or anti-paramagnetic material comprising at least one component, e.g., a metal element, which is ferromagnetic when in at least partially crystalline form, and at least partially crystallizing the at least one component at selected areas of the amorphous layer to form a spaced-apart pattern of at least partially crystallized, ferromagnetic particles or grains of the at least one component, the particles or grains being spaced apart and surrounded by a matrix of the amorphous material. Embodiments include utilizing a focussed or scanned laser source and an amorphous Ni—P layer for forming ferromagnetic Ni particles or grains.Type: GrantFiled: May 6, 2002Date of Patent: June 15, 2004Assignee: Seagate Technology LLCInventors: Connie Chunling Liu, Li-Ping Wang, Linda Lijun Zhong, Jeffery Lee Petrehn
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Publication number: 20040101715Abstract: A magnetic recording medium is formed with a distribution of servo-marks in the form of pits or indentations with an attendant reduction in potential corrosion and increased tribology. Embodiments providing a protective overcoat, e.g. containing carbon, over a magnetic recording medium having a servo-patterned substrate; applying a fluoropolyether comprising one or more acrylate groups on the protective overcoat by dip coating the magnetic recording medium in a solution of the fluoropolyether and polymerizing the fluoropolyether by ultraviolet radiation.Type: ApplicationFiled: November 18, 2003Publication date: May 27, 2004Applicant: SEAGATE TECHNOLOGY LLCInventors: Michael Stirniman, Li-Ping Wang, Gary Rauch
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Patent number: 6680079Abstract: A magnetic recording medium is formed with a distribution of servo-marks in the form of pits or indentations with an attendant reduction in potential corrosion and increased tribology. Embodiments providing a protective overcoat, e.g. containing carbon, over a magnetic recording medium having a servo-patterned substrate; applying a fluoropolyether comprising one or more acrylate groups on the protective overcoat by dip coating the magnetic recording medium in a solution of the fluoropolyether and polymerizing the fluoropolyether by ultraviolet radiation.Type: GrantFiled: June 4, 2001Date of Patent: January 20, 2004Assignee: Seagate Technology LLCInventors: Michael Stirniman, Li-Ping Wang, Gary Rauch
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Patent number: 6663938Abstract: A magnetic data recording medium substrate has a contact zone and a data zone. The contact zone is textured by forming multiple texturing features, each having a bell-shaped profile resembling a Gaussian curve. The features preferably are formed by pulsed laser energy applied to a glass substrate, or to an aluminum nickel-phosphorous substrate coated with a glass layer. As compared to previous laser texturing approaches, the laser beam is less narrowly focused to provide a beam impingement area with a diameter of at least three microns, forming texturing features with diameters of at least three microns. The texturing features preferably are uniform in height and diameter, and may be symmetrical or have asymmetrical aspects, so long as bell-shaped profiles are present in the direction of travel of the recording medium, relative to transducing heads.Type: GrantFiled: December 11, 1998Date of Patent: December 16, 2003Assignee: Seagate Technology LLCInventors: Wei H. Yao, Yuh-Jen Cheng, Li-Ping Wang, David S. Kuo, Chiao-Ping Ku, Bruno Marchon
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Patent number: 6658922Abstract: A method and apparatus for scanning a media is described. More particularly, polarization detector and an atomic force microscope are coupled to a common platform indexed to a spindle. Optionally, an optical microscope may be coupled to the common platform. The polarization detector is used to detect a magnetic image, such as at least a portion of a servo pattern, of the media, and the atomic force microscope, which may be aligned using the magnetic image, is used with a magnetic microscopy module to scan the media. Accordingly, magnetic imagery may be achieved with indexing to a single spindle for positional consistency as between equipment. Moreover, the polarization detector may further be configured to detect scattered light for providing topographic imagery of the media.Type: GrantFiled: November 27, 2001Date of Patent: December 9, 2003Assignee: Seagate Technology LLCInventors: Joseph Leigh, David S. Kuo, Li-Ping Wang, Nobuo Kurataka
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Publication number: 20030133211Abstract: A system and method for servo formatting magnetic media using contact magnetic printing is disclosed. The apparatus includes a dipole magnet that supplies a magnetic field to a magnetic media, a holder for holding the magnetic media, a set of stampers with servo patterns and a press for pressing the magnetic media firmly against the stampers while the magnetic media and stampers are being exposed to a magnetic field and a set of elastomer pads to distribute and equalize the force of the press on the magnetic media. Servo formatting, using the contact magnetic printing apparatus, is done by first positioning the magnetic media against the stampers having servo patterns on them. The magnetic media/stampers stack are then loaded and aligned in a system for contact magnetic printing, applying a force on the magnetic media and stamper so that the two are in firm contact with each other.Type: ApplicationFiled: September 30, 2002Publication date: July 17, 2003Inventors: Li-Ping Wang, Andrew George Prax, David Shaio-Min Kuo
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Publication number: 20030129372Abstract: A material, preferably a magnetic data storage disc, includes a carbon layer covering at least a portion of a magnetic substrate and a crosslinked fluoropolymer layers covering at least a portion of the carbon layer. The crosslinked polymer layer has a thickness less than about 40 angstroms, and the carbon layer has a thickness less than about 100 angstroms. Preferred fluoropolymers include, for example, perfluoropolyethers. In some embodiments, the crosslinked fluoropolymer layer has a thickness at one point on the carbon layer greater than the thickness crosslinked fluoropolymer layer at another point on the carbon layer. The crosslinking generally is performed by irradiating the lubricant material on the carbon layer.Type: ApplicationFiled: June 1, 1999Publication date: July 10, 2003Inventors: MICHAEL J. STIRNIMAN, SAMUEL J. FALCONE, LI-PING WANG, KEVIN J. GRANNEN
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Patent number: 6558771Abstract: High areal recording density, magnetic hard disk recording media including CSS landing zones with laser-textured surfaces having shallow bump heights of from about 40 to about 80 Å, bump spacing in the circumferential and radial directions of from about 10 to about 30 &mgr;m, and bump diameter of from about 4 to about 8 &mgr;m, are provided for use in disk drive systems utilizing padded head sliders operating at very low head slider flying heights of about 0.7&mgr; inch or below.Type: GrantFiled: June 20, 2000Date of Patent: May 6, 2003Assignee: Seagate Technology LLCInventors: Haun Tang, Jing Gui, Samuel John Falcone, Michael Joseph Stirniman, Li-Ping Wang
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Publication number: 20030076612Abstract: A method for thermally writing a magnetic servo pattern on a magnetic disc medium prior to assembling the medium in a disc drive is provided in which the medium is first magnetized in a uniform magnetization direction. A plurality of magnetic domains are then thermally written on the medium, one magnetic domain at a time, by individually heating each magnetic domain with a light beam while exposing the magnetic domain to a magnetic field. The magnetic field has an orientation that is opposite to the uniform magnetization direction. The light beam forms an illumination pattern on the medium having a shape that at least partially defines a boundary of each magnetic domain.Type: ApplicationFiled: November 26, 2002Publication date: April 24, 2003Inventors: Alexei H. Sacks, Li-Ping Wang, Donald E. Curtiss
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Patent number: 6519114Abstract: A storage medium is provided that includes a texture zone having a plurality of protrusions. Each of the protrusions is separated by a short circumferential pitch. Alternatively, the texture zone includes a plurality of protrusions with a circumferential pitch less than the diameter of any protrusion. The resonance excitation between the magnetic head and the storage medium in the data storage system is reduced by forming the texture zone with the protrusions that cause the excitation frequencies of the data storage system to shift away from its resonance frequencies.Type: GrantFiled: March 19, 1999Date of Patent: February 11, 2003Assignee: Seagate Technology, Inc.Inventors: Li-Ping Wang, David Shiao-Min Kuo, Wei Hsin Yao
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Publication number: 20020182444Abstract: A magnetic data storage medium includes a dedicated transducing head contact zone for engaging an air bearing slider, primarily when the disk is stationary and also during disk accelerations and decelerations. The contact zone has a dual baseline texture, formed by first creating a recessed region within the transducing head contact zone, and then by forming multiple nodules or other texturing features within the recessed region. The texturing features project upwardly from a recessed surface of the recessed region, and also project above an upper surface of the disk by an amount less than the texturing feature height. Consequently, the texturing features are large enough to counteract stiction due to liquid lubricant meniscus formation, yet also have heights sufficiently low relative to the upper surface to allow reduced transducer flying heights.Type: ApplicationFiled: May 28, 2002Publication date: December 5, 2002Inventors: David S. Kuo, Li-Ping Wang, Wei H. Yao
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Patent number: 6490117Abstract: A method and apparatus for thermally writing a magnetic servo pattern on a magnetic disc medium prior to assembling the medium in a disc drive are provided in which the medium is first magnetized in a uniform magnetization direction. A plurality of magnetic domains are then thermally written on the medium, one magnetic domain at a time, by individually heating each magnetic domain with a light beam while exposing the magnetic domain to a magnetic field. The magnetic field has an orientation that is opposite to the uniform magnetization direction. The light beam forms an illumination pattern on the medium having a shape that at least partially defines a boundary of each magnetic domain.Type: GrantFiled: October 22, 1999Date of Patent: December 3, 2002Assignee: Seagate Technology LLCInventors: Alexei H. Sacks, Li-Ping Wang, Donald E. Curtiss
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Patent number: 6483299Abstract: An apparatus and a method for measuring the magnetic properties of recording media. Particularly, the invention is directed to the measurement of the coercivity of recording media having high coercivity values. The apparatus for measuring the magnetic properties of recording media contains a thermal source to increase the temperature of a selected portion of the recording media, thus temporally decreasing the coercivity of the recording media in the selected portion. Magnetic transitions are induced by applying a magnetic field to the regions of the medium affected by the thermal source. The electromagnet applies an incrementally increasing DC field to the selected portion to generate variable magnetization data.Type: GrantFiled: November 9, 2000Date of Patent: November 19, 2002Assignee: Seagate Technology LLCInventors: Jason L. Pressesky, Hans Jürgen Richter, Li-Ping Wang
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Publication number: 20020112534Abstract: A method and apparatus for scanning a media is described. More particularly, polarization detector and an atomic force microscope are coupled to a common platform indexed to a spindle. Optionally, an optical microscope may be coupled to the common platform. The polarization detector is used to detect a magnetic image, such as at least a portion of a servo pattern, of the media, and the atomic force microscope, which may be aligned using the magnetic image, is used with a magnetic microscopy module to scan the media. Accordingly, magnetic imagery may be achieved with indexing to a single spindle for positional consistency as between equipment. Moreover, the polarization detector may further be configured to detect scattered light for providing topographic imagery of the media.Type: ApplicationFiled: November 27, 2001Publication date: August 22, 2002Inventors: Joseph Leigh, David S. Kuo, Li-Ping Wang, Nobuo Kurataka
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Patent number: 6405449Abstract: A method and apparatus for data disks adapted to compensate for effects of shock loads imparted to a disk drive which are of sufficient magnitude to cause disk shifts. A series of topographical features are formed on the disk surface or edge to cause signal fluctuation in a sensor during read-back mode operation. An initial signal profile is stored as a map indicative of track or disk alignment with respect to the actuator assembly. Selectively, such as after a known shock event, the topographical features are re-profiled. A comparison of the profiles provides a measure of any track distortion which must be compensated for in future read-write operations by adjustments to data track servo follower algorithms.Type: GrantFiled: February 7, 2001Date of Patent: June 18, 2002Assignee: Seagate Technology, LLCInventors: Ramesh Sundaram, Wei Yao, Li-Ping Wang, David Shiao-Min Kuo
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Patent number: 6403170Abstract: A magnetic data storage medium includes a dedicated transducing head contact zone for engaging an air bearing slider, primarily when the disk is stationary and also during disk accelerations and decelerations. The contact zone has a dual baseline texture, formed by first creating a recessed region within the transducing head contact zone, and then by forming multiple nodules or other texturing features within the recessed region. The texturing features project upwardly from a recessed surface of the recessed region, and also project above an upper surface of the disk by an amount less than the texturing feature height. Consequently, the texturing features are large enough to counteract stiction due to liquid lubricant meniscus formation, yet also have heights sufficiently low relative to the upper surface to allow reduced transducer flying heights.Type: GrantFiled: February 9, 2001Date of Patent: June 11, 2002Assignee: Seagate Technology LLCInventors: David S. Kuo, Li-Ping Wang, Wei H. Yao
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Patent number: 6387530Abstract: High areal storage density, patterned magnetic media comprising a patterned plurality of at least partially crystalline, ferromagnetic particles or grains are provided by means of a simple, economical process wherein a non-magnetic substrate is provided with a layer of an amorphous, paramagnetic or anti-paramagnetic material comprising at least one component, e.g., a metal element, which is ferromagnetic when in at least partially crystalline form, and at least partially crystallizing the at least one component at selected areas of the amorphous layer to form a spaced-apart pattern of at least partially crystallized, ferromagnetic particles or grains of the at least one component, the particles or grains being spaced apart and surrounded by a matrix of the amorphous material. Embodiments include utilizing a focussed or scanned laser source and an amorphous Ni—P layer for forming ferromagnetic Ni particles or grains.Type: GrantFiled: June 14, 2000Date of Patent: May 14, 2002Assignee: Seagate Technology LLCInventors: Connie Chunling Liu, Li-Ping Wang, Linda Lijun Zhong, Jeffery Lee Petrehn
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Patent number: 6377413Abstract: A method and apparatus for processing a magnetic disc prior to assembly of the disc in a disc drive storage assembly includes measuring a physical characteristic of the magnetic disc and encoding an information pattern within the magnetic disc. The information pattern is associated with the measured physical characteristic.Type: GrantFiled: October 22, 1999Date of Patent: April 23, 2002Assignee: Seagate Technology LLCInventors: Alexei H. Sacks, Li-Ping Wang, Donald E. Curtiss
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Patent number: 6377414Abstract: Patterned magnetic media are provided at high resolution and pattern definition by a process comprising steps of: applying to a magnetic layer a first uniform magnetic field of a first direction and strength to pre-align the magnetic grains thereof; applying a second uniform magnetic field of a second, opposite direction and of lesser strength than the first magnetic field, sufficient to change the alignment of the magnetic grains only when the temperature thereof is equal to or greater than the Curie temperature Tc; selectively increasing the temperature of a pattern of selected surface areas of the magnetic layer to at least Tc for an interval while applying the second magnetic field to thereby selectively change the alignment of the magnetic grains of the selectively heated surface areas; terminating application of the second magnetic field after completion of the selective realignment; and cooling the selectively heated surface areas to a temperature below Tc, whereby the magnetic pattern is preserved inType: GrantFiled: November 9, 2000Date of Patent: April 23, 2002Assignee: Seagate Technology LLCInventor: Li-Ping Wang
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Publication number: 20010050091Abstract: Cleaning a media surface, such as a disc surface, comprises subjecting the surface to a detector for sensing the nature of the surface for an irregularity in the smoothness of the surface. Directing, on detecting an irregularity beyond a predetermined amount, a burnishing pulse laser output to that irregularity, and energizing the laser to thereby impart an energy source to reduce the irregularity to a degree less than a predetermined amount.Type: ApplicationFiled: July 5, 2001Publication date: December 13, 2001Applicant: Seagate Technology LLCInventors: Wei Hsin Yao, Ramesh Sundaram, Li-Ping Wang, Chiao-Ping Ku