Patents by Inventor James L. Chao

James L. Chao 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).

  • Perpendicular magnetic recording disk with a soft magnetic layer having a discrete track recording pattern
    Patent number: 7656615
    Abstract: A method of forming a discrete track recording pattern on a soft magnetic underlayer of a perpendicular magnetic recording disk. In one embodiment, the soft magnetic underlayer is continuous throughout the discrete track recording pattern.
    Type: Grant
    Filed: October 27, 2006
    Date of Patent: February 2, 2010
    Assignee: WD Media, Inc.
    Inventors: David E. Wachenschwanz, Gerardo A. Bertero, David Treves, Andrew Homola, James L. Chao, Christopher H. Bajorek
  • Perpendicular magnetic discrete track recording disk
    Patent number: 7608193
    Abstract: A method of forming a discrete track recording pattern on a soft magnetic underlayer of a perpendicular magnetic recording disk. In one embodiment, the soft magnetic underlayer is continuous throughout the discrete track recording pattern.
    Type: Grant
    Filed: October 27, 2006
    Date of Patent: October 27, 2009
    Assignee: WD Media, Inc.
    Inventors: David E. Wachenschwanz, Gerardo A. Bertero, David Treves, Andrew Homola, James L. Chao, Christopher H. Bajorek
  • Method of fabricating a magnetic discrete track recording disk
    Patent number: 7549209
    Abstract: A method of forming a discrete track recording pattern in a magnetic recording disk. In one embodiment, the discrete track recording pattern may be formed in a NiP layer continuous throughout the discrete track recording pattern. Alternatively, the discrete track recording pattern may be formed in a substrate.
    Type: Grant
    Filed: January 21, 2005
    Date of Patent: June 23, 2009
    Assignee: WD Media, Inc.
    Inventors: David E. Wachenschwanz, Gerardo A. Bertero, David Treves, Andrew Homola, James L. Chao, Christopher H. Bajorek
  • Perpendicular magnetic discrete track recording disk
    Patent number: 7147790
    Abstract: A method of forming a discrete track recording pattern on a soft magnetic underlayer of a perpendicular magnetic recording disk. In one embodiment, the soft magnetic underlayer is continuous throughout the discrete track recording pattern.
    Type: Grant
    Filed: November 27, 2002
    Date of Patent: December 12, 2006
    Assignee: Komag, Inc.
    Inventors: David E. Wachenschwanz, Gerardo A. Bertero, David Treves, Andrew Homola, James L. Chao, Christopher H. Bajorek
  • Perpendicular magnetic discrete track recording disk
    Publication number: 20040101713
    Abstract: A method of forming a discrete track recording pattern on a soft magnetic underlayer of a perpendicular magnetic recording disk. In one embodiment, the soft magnetic underlayer is continuous throughout the discrete track recording pattern.
    Type: Application
    Filed: November 27, 2002
    Publication date: May 27, 2004
    Inventors: David E. Wachenschwanz, Gerardo A. Bertero, David Treves, Andrew Homola, James L. Chao, Christopher H. Bajorek
  • Thin overlayer for magnetic recording disk
    Patent number: 6358636
    Abstract: Protective overlayers for magnetic recording media are described. The overlayers, composed of a transition metal-silicon or transition metal-germanium interlayer and a carbon overcoat, provide good wear resistance and corrosion resistance at thicknesses of less than 100 Å.
    Type: Grant
    Filed: January 20, 1999
    Date of Patent: March 19, 2002
    Assignee: HMT Technology Corporation
    Inventors: Ming M. Yang, Zhangmin Wang, James L. Chao, Michael A. Russak
  • Magnetic recording medium having a nitrogen-containing barrier layer
    Patent number: 6146737
    Abstract: A magnetic recording medium having a barrier layer deposited directly on the magnetic recording layer is described. The barrier layer is deposited by sputter deposition under a nitrogen-containing sputtering atmosphere to form a nitrogen-containing chromium or chromium alloy barrier layer. The barrier layer is effective to inhibit migration of cobalt from the underlying magnetic recording layer, reducing corrosion of the medium and improving magnetic recording performance.
    Type: Grant
    Filed: September 18, 1998
    Date of Patent: November 14, 2000
    Assignee: HMT Technology Corporation
    Inventors: Sudhir S. Malhotra, Brij Bihari Lal, James L. Chao, Michael A. Russak
  • Device for texturing a disc substrate
    Patent number: 5810648
    Abstract: A texturing device for texturing a disc substrate of the type used in forming a thin-film medium is described. The device includes a rotatable assembly having a first pad attached to one end of a spindle and an annular ring having a second pad attached on one surface. Each pad defines a texturing surface for texturing the inner and outer regions of the disc substrate.
    Type: Grant
    Filed: March 5, 1997
    Date of Patent: September 22, 1998
    Assignee: HMT Technology Corporation
    Inventors: Zhaoguo Jiang, Ming M. Yang, James L. Chao, Bruce M. Harper, Michael A. Russak
  • Lubricant composition and method
    Patent number: 5587217
    Abstract: A thin-film magnetic recording disc for use with a read/write head in a disc drive is disclosed. To reduce the static and dynamic frictional coefficients of the disc surface, the disc is coated with a lubricant layer composed of a mixture of a polyphenoxycyclotriphosphazene lubricant and a perfluoropolyether oil. Also disclosed is a lubricant composition containing these two components, as well as a method for improving the lubricating properties of a perfluoropolyether oil.
    Type: Grant
    Filed: June 30, 1995
    Date of Patent: December 24, 1996
    Assignee: HMT Technology Corporation
    Inventors: James L. Chao, Yu-Cheun Lee, Chao Gao
  • Magnetic recording disk with overcoat thickness gradient between a data zone and a landing zone
    Patent number: 5520981
    Abstract: An improvement in a magnetic recording disc having a protective overcoat is described. The overcoat extends between an inner-diameter landing zone and a data zone and has a thickness in the landing zone of at least 135 .ANG. and a thickness in the data zone of less than 90 .ANG..
    Type: Grant
    Filed: April 24, 1995
    Date of Patent: May 28, 1996
    Assignee: HMT Technology Corporation
    Inventors: Ming M. Yang, James L. Chao, Michael A. Russak