Patents by Inventor Calvin S. Lo

Calvin S. Lo 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: 20190362750
    Abstract: A method for measuring a distance between features of a sample, according to one embodiment, includes moving a precision stage having the sample thereon for positioning a first feature of the sample in a field of view of an imaging device. The imaging device is instructed to generate a first image of the first feature of the sample. The sample is moved a defined distance using the precision stage. The imaging device is instructed to generate a second image of a second feature of the sample at the defined distance. The first image and the second image are used to determine an actual distance between the first feature and the second feature. A product, according to one embodiment, includes a thin film structure having a plurality of elements, and at least two features dedicated for enabling measurement therebetween. Each feature is positioned at a known position relative to a respective one of the elements.
    Type: Application
    Filed: May 22, 2018
    Publication date: November 28, 2019
    Inventors: Robert G. Biskeborn, Jason Liang, Calvin S. Lo
  • Patent number: 10490211
    Abstract: Provided are a tape head module, tape drive, and method for moving a tape medium over a tape head having a recessed portion to provide air bearing between a tape medium and a tape bearing surface of the module. The tape head includes a tape bearing surface, an array of transducers, including read and/or write transducers, on the tape bearing surface, and a recessed portion formed on the tape bearing surface, wherein the array of transducers is located on the tape bearing surface between the recessed portion and an end of the module to perform read and/or write operations with respect to the tape medium.
    Type: Grant
    Filed: March 16, 2018
    Date of Patent: November 26, 2019
    Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Robert G. Biskeborn, Calvin S. Lo
  • Publication number: 20190341071
    Abstract: Provided is a method for forming a tape head module having recessed portion to provide air bearing between a tape medium and a tape bearing surface of the tape head module. A module of the tape head has a first end, a second end opposite the first end, a first side and a second side, opposite the first side, between the first and the second ends, a tape bearing surface and a second surface, opposite the tape bearing surface, between the first end, the second end, the first side, and the second side. Material is removed from the tape bearing surface of the module to form a first recessed portion between the first end and before a region of the tape bearing surface having an array of transducers, and between the first side and the second side.
    Type: Application
    Filed: May 1, 2018
    Publication date: November 7, 2019
    Inventors: Robert Biskeborn, Calvin S. Lo
  • Publication number: 20190318761
    Abstract: An apparatus, according to one embodiment, includes a first circuit electrically coupled to a first read transducer and a first parallel circuit, the first read transducer having a tunnel valve structure having a resistance. A second circuit is electrically coupled to a second read transducer having a tunnel valve structure. An area of a tunnel barrier portion of the second read transducer along a plane of deposition thereof is larger than an area of a tunnel barrier portion of the first read transducer along a plane of deposition thereof.
    Type: Application
    Filed: June 26, 2019
    Publication date: October 17, 2019
    Inventors: Robert G. Biskeborn, Robert E. Fontana, JR., Calvin S. Lo
  • Publication number: 20190311736
    Abstract: A magnetic recording medium according to one embodiment includes an underlayer and a magnetic layer above the underlayer. The magnetic layer includes a first magnetic material and particulates. A solid protective layer is positioned above the magnetic layer, the protective layer including a second material. At least some of the particulates of the magnetic layer protrude completely through the protective layer. A method for forming a magnetic recording medium according to one embodiment includes forming a magnetic layer above a substrate, the magnetic layer including a first magnetic material and particulates, and forming a solid protective layer above the magnetic layer to a thickness whereby some of the particulates protrude through the protective layer and are exposed along an upper surface of the protective layer.
    Type: Application
    Filed: June 20, 2019
    Publication date: October 10, 2019
    Inventors: Robert G. Biskeborn, Calvin S. Lo
  • Publication number: 20190311740
    Abstract: A method according to one embodiment includes running a magnetic recording tape over a tape bearing surface of a module having at least one edge, detecting signals from the tape at differing wrap angles for estimating a height of tenting of the tape above a transducer at each of the wrap angles, and selecting a wrap angle to provide about a predefined height of tenting of the tape above the transducer. A resulting tent of the moving magnetic recording tape extends from the edge of the module closest thereto to a minima with a tent apex therebetween, where the minima is at a first point of closest approach of the moving magnetic recording tape to the tape bearing surface of the module nearest the tent apex.
    Type: Application
    Filed: June 18, 2019
    Publication date: October 10, 2019
    Inventors: Robert G. Biskeborn, W. Stanley Czarnecki, Calvin S. Lo
  • Publication number: 20190304502
    Abstract: In one embodiment, a computer program product for determining a wrap angle includes a computer readable storage medium having program instructions embodied therewith, wherein the computer readable storage medium is not a transitory signal per se. The program instructions are executable by a processor to cause the processor to perform a method that includes receiving, by the processor, a measurement of a distance from an edge to a transducer, receiving, by the processor, a predefined height of tenting of a magnetic recording tape above the transducer, and determining, by the processor, a wrap angle for inducing tenting of the magnetic recording tape above the transducer at the predefined height when the magnetic recording tape passes over the edge in a direction of tape travel thereacross.
    Type: Application
    Filed: June 19, 2019
    Publication date: October 3, 2019
    Inventors: Robert G. Biskeborn, W. Stanley Czarnecki, Calvin S. Lo
  • Publication number: 20190304501
    Abstract: In one embodiment, a method includes determining a distance from a to an edge closest thereto and selecting a wrap angle based on the determined distance for inducing tenting of a moving magnetic recording tape in a region above the transducer whereby a resulting tent of the moving tape extends from the edge closest thereto to a minima with a tent apex therebetween. In response to a determination to move the tape over the tape bearing surface, the method includes moving the tape over the tape bearing surface, and checking for changes in the tenting characteristics. In response to determining changes are present, the method includes sequentially selecting a different wrap angle based on the determined distance for inducing a desired tenting characteristic, and checking for changes in the tenting characteristics. Moreover, the method includes selecting a final wrap angle in response to determining no significant changes are present.
    Type: Application
    Filed: June 18, 2019
    Publication date: October 3, 2019
    Inventors: Robert G. Biskeborn, W. Stanley Czarnecki, Calvin S. Lo
  • Publication number: 20190304494
    Abstract: A method for forming a magnetic recording medium according to one embodiment includes forming a magnetic layer above an underlayer. The magnetic layer includes a first magnetic material and particulates. A protective layer is formed above the magnetic layer, the protective layer including a second material. A method for forming a magnetic recording medium according to another embodiment includes forming a first nonmagnetic layer above a base film. The first nonmagnetic layer has first nonmagnetic particles. A second nonmagnetic layer is formed above the first nonmagnetic layer, the second nonmagnetic layer having second nonmagnetic particles. A magnetic layer is formed above the second nonmagnetic layer, the magnetic layer including a magnetic material.
    Type: Application
    Filed: June 20, 2019
    Publication date: October 3, 2019
    Inventors: Robert G. Biskeborn, Calvin S. Lo
  • Publication number: 20190304495
    Abstract: A magnetic recording medium according to one embodiment includes a base film and a first nonmagnetic layer above the base film. The first nonmagnetic layer has first nonmagnetic particles. A second nonmagnetic layer is positioned above the first nonmagnetic layer, the second nonmagnetic layer having second nonmagnetic particles. A magnetic layer is positioned above the second nonmagnetic layer, the magnetic layer including a magnetic material.
    Type: Application
    Filed: June 20, 2019
    Publication date: October 3, 2019
    Inventors: Robert G. Biskeborn, Calvin S. Lo
  • Publication number: 20190287555
    Abstract: Provided are a tape head module, tape drive, and method for moving a tape medium over a tape head having a recessed portion to provide air bearing between a tape medium and a tape bearing surface of the module. The tape head includes a tape bearing surface, an array of transducers, including read and/or write transducers, on the tape bearing surface, and a recessed portion formed on the tape bearing surface, wherein the array of transducers is located on the tape bearing surface between the recessed portion and an end of the module to perform read and/or write operations with respect to the tape medium.
    Type: Application
    Filed: March 16, 2018
    Publication date: September 19, 2019
    Inventors: Robert G. Biskeborn, Calvin S. Lo
  • Patent number: 10418059
    Abstract: In one general embodiment, a method includes determining a distance from a transducer of a module to an edge of the module closest thereto, and selecting a wrap angle based on the determined distance for inducing tenting of a moving magnetic recording tape in a region above the transducer. In another general embodiment, a method includes running a magnetic recording tape over a tape bearing surface having at least one edge, and detecting signals from the tape at differing wrap angles for estimating a height of tenting of the tape above a transducer at each of the wrap angles. A wrap angle is selected to provide about a predefined height of tenting of the tape above the transducer.
    Type: Grant
    Filed: December 6, 2016
    Date of Patent: September 17, 2019
    Assignee: International Business Machines Corporation
    Inventors: Robert G. Biskeborn, W. Stanley Czarnecki, Calvin S. Lo
  • Patent number: 10395676
    Abstract: An apparatus, according to one embodiment, includes a first circuit comprising a pair of terminals coupled to a first read transducer having a tunnel valve structure and a first parallel circuit. A second circuit has a pair of terminals that are coupled to a second read transducer having a tunnel valve structure. An area of a tunnel barrier portion of the second read transducer is larger than an area of a tunnel barrier portion of the first read transducer. The terminal resistance of the first circuit is less than about five times a terminal resistance of the second circuit.
    Type: Grant
    Filed: January 11, 2018
    Date of Patent: August 27, 2019
    Assignee: International Business Machines Corporation
    Inventors: Robert G. Biskeborn, Robert E. Fontana, Jr., Calvin S. Lo
  • Patent number: 10395684
    Abstract: A magnetic recording medium according to one embodiment includes an underlayer and a magnetic layer above the underlayer. The magnetic layer includes a first magnetic material and particulates. A protective layer is positioned above the magnetic layer, the protective layer including a second material. A magnetic recording medium according to another embodiment includes a base film and a first nonmagnetic layer above the base film. The first nonmagnetic layer has first nonmagnetic particles. A second nonmagnetic layer is positioned above the first nonmagnetic layer, the second nonmagnetic layer having second nonmagnetic particles. A magnetic layer is positioned above the second nonmagnetic layer, the magnetic layer including a magnetic material.
    Type: Grant
    Filed: May 18, 2016
    Date of Patent: August 27, 2019
    Assignee: International Business Machines Corporation
    Inventors: Robert G. Biskeborn, Calvin S. Lo
  • Patent number: 10388308
    Abstract: An apparatus, according to one embodiment, includes: a transducer structure having: a lower shield, an upper shield above the lower shield, a current-perpendicular-to-plane sensor between the upper and lower shields, an electrical lead layer between the sensor and one of the shields, and a spacer layer between the electrical lead layer and the one of the shields. The upper and lower shields provide magnetic shielding. The electrical lead layer is in electrical communication with the sensor. A conductivity of the electrical lead layer is higher than a conductivity of the spacer layer. A width of the electrical lead layer in a cross-track direction is greater than the width of a free layer of the sensor.
    Type: Grant
    Filed: February 1, 2018
    Date of Patent: August 20, 2019
    Assignee: International Business Machines Corporation
    Inventors: Robert G. Biskeborn, Robert E. Fontana, Jr., Calvin S. Lo
  • Patent number: 10360933
    Abstract: In one embodiment, an apparatus includes a transducer structure having a lower shield and an upper shield, the upper and lower shields providing magnetic shielding. A current-perpendicular-to-plane sensor is positioned between the upper and lower shields. An electrical lead layer is positioned between the sensor and one of the shields. The electrical lead layer is in electrical communication with the sensor. A resistance of the electrical lead layer along a direction orthogonal to a media facing surface is less than a resistance across the sensor along a direction parallel to the media facing surface. A spacer layer is positioned between the electrical lead layer and the one of the shields. One or both of the shields has at least one laminate pair comprising a magnetically permeable layer and a harder layer, the harder layer having a mechanical hardness that is higher than a mechanical hardness of the magnetically permeable layer.
    Type: Grant
    Filed: April 25, 2018
    Date of Patent: July 23, 2019
    Assignee: International Business Machines Corporation
    Inventors: Robert G. Biskeborn, Calvin S. Lo
  • Patent number: 10354679
    Abstract: An apparatus according to one embodiment includes a first read transducer having a tunnel valve structure, and a second read transducer coupled to the first read transducer. The second read transducer has a tunnel valve structure as well, but the tunnel valve structure of the first read transducer has a different resistivity than the tunnel valve structure of the second read transducer. An apparatus according to another embodiment includes an array of first read transducers, each first read transducer having a tunnel valve structure. At least a second read transducer is coupled to the first read transducers, the second read transducer having a tunnel valve structure. The tunnel valve structure of the first read transducer has a different resistivity than the tunnel valve structure of the second read transducer.
    Type: Grant
    Filed: December 13, 2016
    Date of Patent: July 16, 2019
    Assignee: International Business Machines Corporation
    Inventors: Robert G. Biskeborn, Robert E. Fontana, Jr., Calvin S. Lo
  • Patent number: 10332550
    Abstract: An apparatus according to one embodiment includes an array of magnetic transducers each having: a current-perpendicular-to-plane sensor, and a stabilizing layered structure adjacent the sensor. The stabilizing layered structure includes a first ferromagnetic layer, a second ferromagnetic layer, and an antiparallel coupling layer between the ferromagnetic layers. Each transducer also includes an electrical lead layer positioned between the sensor and the stabilizing layered structure. The electrical lead layer is in electrical communication with the sensor. Each transducer also includes a spacer layer between the respective electrical lead layer and the stabilizing layered structure. A conductivity of the electrical lead layer is higher than a conductivity of the spacer layer.
    Type: Grant
    Filed: October 19, 2017
    Date of Patent: June 25, 2019
    Assignee: International Business Machines Corporation
    Inventors: Robert G. Biskeborn, Robert E. Fontana, Jr., Calvin S. Lo
  • Publication number: 20190180776
    Abstract: In one general embodiment, an apparatus includes a module having a tape bearing surface and an array of write transducers extending along the tape bearing surface. Each write transducer has a first write pole having a pole tip extending from a media facing side of the first write pole, a second write pole having a pole tip extending from a media facing side of the second write pole, a nonmagnetic write gap between the pole tips of the write poles, and a high moment layer between the pole tips of the write poles. The high moment layer has a higher magnetic moment than a magnetic moment of the pole tip of the second write pole. The tape bearing surface of the module has patterning, and/or a first tape tenting region where each write transducer is positioned in the first tape tenting region.
    Type: Application
    Filed: December 12, 2017
    Publication date: June 13, 2019
    Inventors: Robert G. Biskeborn, Calvin S. Lo
  • Publication number: 20190180779
    Abstract: An apparatus according to one embodiment includes a module having a plurality of tunnel valve read transducers arranged in an array extending along the tape bearing surface of the module. Each of the tunnel valve read transducers has upper and lower shields for providing magnetic shielding. A sensor structure is positioned between the shields. An electrical lead layer is positioned between the sensor structure and one of the shields. The electrical lead layer is in electrical communication with the sensor structure. A spacer layer is positioned between the electrical lead layer and the one of the shields. A conductivity of the electrical lead layer is higher than a conductivity of the spacer layer. At least some of the sensor structures are recessed from a plane extending along the tape bearing surface. An at least partially polycrystalline coating is positioned on a media facing side of the recessed sensor structures.
    Type: Application
    Filed: December 12, 2017
    Publication date: June 13, 2019
    Inventors: Robert G. Biskeborn, Calvin S. Lo