Patents by Inventor Ching Tsang

Ching Tsang 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).

  • Publication number: 20070035891
    Abstract: A magnetoresistive sensor having a pinned layer that extends beyond the stripe height defined by the free layer of the sensor. The extended pinned layer has a strong shape induced anisotropy that maintains pinning of the pinned layer moment. The extended portion of the pinned layer has sides beyond the stripe height that are perfectly aligned with the sides of the sensor within the stripe height. This perfect alignment is made possible by a manufacturing method that uses a mask structure for more than one manufacturing phase, eliminating the need for multiple mask alignments.
    Type: Application
    Filed: August 15, 2005
    Publication date: February 15, 2007
    Inventors: James Freitag, Kuok Ho, Mustafa Pinarbasi, Ching Tsang
  • Publication number: 20060285257
    Abstract: A continuous-media or patterned-media disk drive with a low ratio of linear bit density in bits per inch (BPI) in the along-the-track direction to track density in tracks per inch (TPI) in the cross-track direction has a magnetoresistive read head with high cross-track spatial resolution. The read head is located between two magnetic shields, with the shields and read head formed on a side surface of the head carrier perpendicular to the carrier's disk-facing surface. The carrier is supported by the disk drive actuator with the side surface of the carrier oriented generally parallel to the data tracks. In this arrangement the high-spatial-resolution direction of the read head (the transverse direction perpendicular to the side surface on which the head is formed) is in the radial or cross-track direction.
    Type: Application
    Filed: June 21, 2005
    Publication date: December 21, 2006
    Inventors: Thomas Albrecht, Robert Fontana, Ching Tsang, Mason Williams, Bruce Wilson
  • Publication number: 20060092566
    Abstract: A double notched magnetic structure for use in a magnetic head for avoiding stray field writing. The structure could be a magnetic shield, magnetic pole of a write head or some other magnetic structure used in a magnetic head of a magnetic recording system, and has notches formed at both the front end (adjacent to the ABS) and at the back end (away from the ABS). The notches at the front end form a forward protruding portions that performs the necessary function of the structure, such as magnetic shielding, and has laterally extending recessed portions (recessed by the front notches) that move the flux focal points of the structure away from the ABS to avoid stray field writing. The back notches form a backward extending portion that affects the geometry of the structure to prevent the focusing of magnetic flux caused by stray magnetic fields having a component perpendicular to the ABS.
    Type: Application
    Filed: October 29, 2004
    Publication date: May 4, 2006
    Inventors: Kuok Ho, Yimin Hsu, Ching Tsang
  • Publication number: 20060092562
    Abstract: Embodiments of the present invention are directed to structures of a recording head having a winged design for reducing corner stray magnetic fields. In one embodiment, the present invention comprises a magnetic recording head comprising a plurality of components. In embodiments of the present invention at least one of the plurality of components comprises a surface exposed to an air bearing surface when in operation with a recording medium. The surface exposed to the air bearing surface comprises notched edges for constraining corner stray magnetic fields associated therewith.
    Type: Application
    Filed: October 29, 2004
    Publication date: May 4, 2006
    Inventors: Kuok Ho, Yimin Hsu, Masafumi Mochizuki, Ching Tsang, Roger Wood
  • Publication number: 20060092565
    Abstract: A magnetic structure for use in a magnetic head for avoiding stray field writing. The magnetic structure can be for example a magnetic shield or could be a magnetic pole of a write head and is particularly advantageous for use in a perpendicular recording system, because such perpendicular recording systems are especially susceptible to stray field writing. The magnetic structure includes a forward protruding portion that extends toward the air bearing surface (ABS) of the head also includes first and second wing portions that extend laterally from the forward protruding portion. The wing portions each have a front edge that is recessed from the ABS. The wings are tapered so that the amount of recess of the front edge of the wings increases with lateral distance from the center of the magnetic structure.
    Type: Application
    Filed: October 29, 2004
    Publication date: May 4, 2006
    Inventors: Kuok Ho, Yimin Hsu, Ching Tsang
  • Publication number: 20060082932
    Abstract: A read head has a bottom lead made of material that is relatively polish resistant and a top lead layer that polishes down more easily than the bottom layer. With this structure, when the layers are deposited and then polished down, the top layer recesses away from the sensor (and bottom lead layer) in a controlled fashion, providing an acceptable lead structure that reduces the mismatch between the read head physical read width and magnetic read width.
    Type: Application
    Filed: December 1, 2005
    Publication date: April 20, 2006
    Inventors: Marie-Claire Cyrille, Frederick Dill, Kuok Ho, Jui-Lung Li, Scott MacDonald, James Nix, Ching Tsang
  • Publication number: 20060067004
    Abstract: Magnetic sensors are fabricated with an initial length that is slightly longer than their finished length. The sensors are then critically lapped and exposed for target signal output. The final target length of the sensors is obtained by first exposing the sensors to a photolithographic process and then directly lapping the excess length from the sensors. The length of sensor material that is removed is in the range of several nanometers. The target end point during lapping may be ascertained by detecting the change in resistance between the sensor and leads in the lapping tool as the excess material is lapped from the sensor.
    Type: Application
    Filed: September 30, 2004
    Publication date: March 30, 2006
    Applicant: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Marie-Claire Cyrille, Ching Tsang, Huey-Ming Tzeng
  • Publication number: 20060067016
    Abstract: Current-perpendicular-to-the-plane (CPP), current-in-to-the-plane (CIP), and tunnel valve type sensors are provided having an antiparallel (AP) coupled free layer structure, an in-stack biasing structure which stabilizes the AP coupled free layer structure and a nonmagnetic spacer layer formed between the in-stack biasing layer and the AP coupled free layer structure. The AP coupled free layer structure has a first AP coupled free layer adjacent to the nonmagnetic spacer layer, a second AP coupled free layer, and an antiparallel coupling (APC) layer formed between the first and the second AP coupled free layers. The net moment of the AP coupled free layer structure has an antiparallel edge magnetostatic coupling with the in-stack biasing structure. At the same time, the first AP coupled free layer has an antiparallel exchange coupling with the second AP coupled free layer.
    Type: Application
    Filed: September 30, 2004
    Publication date: March 30, 2006
    Inventors: Jeffrey Childress, Robert Fontana, Kuok Ho, Ching Tsang
  • Publication number: 20050264944
    Abstract: A magnetic head (slider) which requires no lapping is described. The head is fabricated with an air bearing surface that is parallel to the wafer surface. The saw cuts used to separate the individual sliders from the rest of the wafer are perpendicular to the air-bearing surface and do not pass through any critical features. The read and write components are formed from thin films disposed parallel to the air bearing surface and can be side-by-side or tandem in relation to the recording track. The stripe height of the read sensor is controlled by the deposition process rather than by lapping. Various embodiments of the read head include contiguous junction biasing, external hard magnet biasing, and in-stack biasing. In one embodiment a permeable field collector is included below the sensor layer structure. An aperture shield surrounding the sensor at the ABS is included in one embodiment.
    Type: Application
    Filed: May 28, 2004
    Publication date: December 1, 2005
    Inventors: Robert Fontana, Kuok Ho, Ching Tsang
  • Publication number: 20050243463
    Abstract: A magnetic head (slider) for perpendicular recording which requires no lapping is described. The head is fabricated with an air bearing surface that is parallel to the wafer surface. The coil and pole pieces are formed from thin films disposed parallel to the air bearing surface. Standard lithographic techniques can be used to define the shapes, gaps and pole piece dimensions. Non-rectilinear shapes can be formed; for example, side shields that conform around the write pole piece region. The thickness of the main and return pole pieces are controlled by the deposition process rather than by lapping. The saw cuts used to separate the individual sliders from the rest of the wafer are perpendicular to the air-bearing surface and do not pass through any critical features.
    Type: Application
    Filed: April 30, 2004
    Publication date: November 3, 2005
    Inventors: Robert Fontana, Kuok Ho, Ching Tsang
  • Publication number: 20050180061
    Abstract: A self pinned magnetoresistive sensor that has a relatively thick compressive material at either side to assist with self pinning. A shield having recessed portions at either side of the sensor area allows room for a thicker compressive layer than would otherwise be possible.
    Type: Application
    Filed: February 18, 2004
    Publication date: August 18, 2005
    Inventors: Meng Ding, Robert Fontana, Kuok Ho, Neil Robertson, Ching Tsang
  • Publication number: 20050146812
    Abstract: Several embodiments of a sense current perpendicular to the planes of the sensor (CPP) and flux guide type of read head has a gap between first and second shield layers at an air bearing surface (ABS) where the flux guide is located which is less than a gap between the first and second shield layers at a recessed location where the sensor is located. This reduced gap increases the linear bit density capability of the read head. A longitudinal bias stack (LBS) is located in the sensor stack. Several unique methods of construction are described for forming the magnetic head assemblies.
    Type: Application
    Filed: March 7, 2005
    Publication date: July 7, 2005
    Applicant: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Robert Fontana, Kuok Ho, Tao Pan, Ching Tsang
  • Publication number: 20050024782
    Abstract: A read head has a bottom lead made of material that is relatively polish resistant and a top lead layer that polishes down more easily than the bottom layer. With this structure, when the layers are deposited and then polished down, the top layer recesses away from the sensor (and bottom lead layer) in a controlled fashion, providing an acceptable lead structure that reduces the mismatch between the read head physical read width and magnetic read width.
    Type: Application
    Filed: July 29, 2003
    Publication date: February 3, 2005
    Applicant: Hitachi Global Storage Technologies
    Inventors: Marie-Claire Cyrille, Frederick Dill, Kuok Ho, Jui-Lung Li, Scott MacDonald, James Nix, Ching Tsang
  • Patent number: 5310155
    Abstract: A golf cart umbrella holder comprising a mounting device fastened to the frame of a golf cart by a screw, a clamping device fastened to the mounting device by a screw to hold a socket for holding an umbrella. The clamping device has teeth on a contact wall to the mounting device around a circle respectively meshed with teeth on the mounting device. By changing the meshing order between the teeth on the mounting device and the teeth on the clamping device, the angular position of the umbrella relative to the golf cart is adjusted.
    Type: Grant
    Filed: July 21, 1992
    Date of Patent: May 10, 1994
    Inventor: Ching-Tsang Wu
  • Patent number: 5282308
    Abstract: A method for fabricating a thin film magnetic head assembly including the procedure of hardening a portion of the upper pole-tip photoresist mask to create a planarizing stitching pedestal in the region where the upper pole-tip overlaps with the upper pole-yoke. The upper pole assembly is deposited in two steps to create a stitched pole consisting of an upper pole-tip joined to an upper pole-yoke element at the stitching pedestal. The method reduces process complexity by eliminating masking steps and also eliminates the usual close alignment requirements for upper insulation and pole-yoke deposition procedures, thereby improving process yield.
    Type: Grant
    Filed: December 29, 1992
    Date of Patent: February 1, 1994
    Assignee: International Business Machines Corporation
    Inventors: Mao-Min Chen, Kochan Ju, Rodney E. Lee, Ching Tsang
  • Patent number: 4690891
    Abstract: The present invention is a method and the microorganism and enzyme used therein to degrade the Xanthan molecule. The microorganism is a soil bacterium, Bacillus sp. The method includes using the mixed culture, or a supernatant derived therefrom or the purified enzyme itself.
    Type: Grant
    Filed: September 11, 1985
    Date of Patent: September 1, 1987
    Assignee: Exxon Research and Engineering Company
    Inventors: Ching-Tsang Hou, Nancy P. Barnabe
  • Patent number: 4375515
    Abstract: Disclosed are newly discovered and isolated methylotrophic microorganism strains and their natural and/or artificial mutants which grow well under aerobic conditions in a culture medium in the presence of methane as the major carbon and energy source. The methane-grown microbial cells possess a high content of protein and can be utilized as such as feedstuffs. The methane-grown microbial cells or enzyme preparations thereof are also useful in converting C.sub.1 -C.sub.6 alkanes to alcohols, particularly methane to methanol, C.sub.3 -C.sub.6 alkanes to the corresponding C.sub.3 -C.sub.6 sec. alcohols and methyl ketones, C.sub.3 -C.sub.6 sec. alcohols to the corresponding methyl ketones, cyclic hydrocarbons to cyclic hydrocarbyl alcohols (e.g., cyclohexane to cyclohexanol) C.sub.2 -C.sub.4 alkenes selected from the group consisting of ethylene, propylene, butene-1 and butadiene to 1,2-epoxides, styrene to styrene oxide, and converting other oxidizable substrates to oxidized products.
    Type: Grant
    Filed: December 11, 1980
    Date of Patent: March 1, 1983
    Assignee: Exxon Research and Engineering Co.
    Inventors: Ramesh N. Patel, Ching-Tsang Hou, Allen I. Laskin
  • Patent number: 4368267
    Abstract: A process is disclosed for the epoxidation of lower .alpha.-olefins dienes or vinyl aromatic compounds by contacting said compounds, under aerobic conditions in the presence of microorganisms, genetically engineered organisms thereof or enzyme preparations derived from said microorganisms. The microorganisms, genetically engineered organisms, or enzyme preparations derived therefrom are preferably those microorganisms which are known as methylotrophs particularly those which have previously grown under aerobic conditions in a nutrient medium containing methane.
    Type: Grant
    Filed: February 6, 1980
    Date of Patent: January 11, 1983
    Assignee: Exxon Research and Engineering Co.
    Inventors: Ching-Tsang Hou, Ramesh N. Patel, Allen I. Laskin
  • Patent number: 4347319
    Abstract: A process is disclosed for the microbiological epoxidation of C.sub.2 -C.sub.4 n-alkenes, dienes and vinyl aromatic compounds by contacting, under aerobic conditions, in an aqueous medium containing microorganisms or enzyme preparations derived therefrom, wherein the microorganisms have been aerobically cultivated in a nutrient medium containing methane. The microorganisms used are newly isolated methane-utilizing obligate and facultative methylotrophs.
    Type: Grant
    Filed: October 24, 1980
    Date of Patent: August 31, 1982
    Assignee: Exxon Research & Engineering Co.
    Inventors: Ching-Tsang Hou, Ramesh N. Patel, Allen I. Laskin
  • Patent number: 4269940
    Abstract: Disclosed is a process for the microbiological oxidation of C.sub.1 -C.sub.6 alkanes and cycloalkanes by contacting said C.sub.1 -C.sub.6 alkanes or cycloalkanes, under aerobic conditions, in the presence of microorganisms or enzyme preparations derived therefrom, wherein said microorganisms have been aerobically grown in a nutrient containing methane. The microorganisms are newly isolated obligative and facultative methylotrophs.
    Type: Grant
    Filed: March 27, 1979
    Date of Patent: May 26, 1981
    Assignee: Exxon Research & Engineering Co.
    Inventors: Ramesh N. Patel, Ching-Tsang Hou, Allen I. Laskin