Patents by Inventor Theodore A. Schwarz

Theodore A. Schwarz 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).

  • Patent number: 5312644
    Abstract: A thin-film magnetoresistive playback head having films providing magnetic shielding and magnetic bias. At least one of the magnetic shield layers is also conductive so that the functions of shielding and biasing are combined. Preferably, both shield layers are conductive. A multiple element channel head is disclosed in which the magnetic/conductive layers extend in series from one transducer section to the next, allowing a single bias current to bias all of the sections.
    Type: Grant
    Filed: September 17, 1993
    Date of Patent: May 17, 1994
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: Theodore A. Schwarz, Peter G. Bischoff, Chak M. Leung, Johnny C. Chen, Pradeep Thayamballi
  • Patent number: 5311385
    Abstract: A thin-film magnetoresistive playback head having films providing magnetic shielding and magnetic bias. At least one of the magnetic shield layers is also conductive so that the functions of shielding and biasing are combined. Preferably, both shield layers are conductive. A multiple element channel head is disclosed in which the magnetic/conductive layers extend in series from one transducer section to the next, allowing a single bias current to bias all of the sections.
    Type: Grant
    Filed: December 18, 1991
    Date of Patent: May 10, 1994
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: Theodore A. Schwarz, Peter G. Bischoff, Chak M. Leung, Johnny C. Chen, Pradeep Thayamballi
  • Patent number: 5280402
    Abstract: A mechanism for accurately following the center of a track includes a voice coil, or a voice coil and stepper motor in combination. The voice coil and stepper motor combination operate to variably position a recording head transversely with respect to the width of the recording tape. The mechanism enables head positioning with very close tolerances due to the ability of the voice coil to finely position the head very accurately on the center of a track.
    Type: Grant
    Filed: July 17, 1992
    Date of Patent: January 18, 1994
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: James S. Anderson, Noel L. Allen, Durkee B. Richards, Theodore A. Schwarz, Robert W. Tapani, Hung T. Tran, Robert J. Youngquist
  • Patent number: 5229895
    Abstract: This invention relates to a magnetic recording head assembly and method enabling an end user to record a unique servo control track on a magnetic recording tape while the tape is in the recorder to be used for recording and playback of computer data. Previously, most such control tracks were applied only at the time of manufacture of preformatted media. The invented head assembly includes, in addition to a plurality of sets of read/write transducers, a servo write head having an extended transverse width for uniformly recording a servo signal across the width of a servo track section, and a servo erase head having a plurality of alternating erasing and non-erasing sections adapted to controllably erase portions of the previously recorded servo signal, resulting in unique servo control tracks.
    Type: Grant
    Filed: June 7, 1991
    Date of Patent: July 20, 1993
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: Theodore A. Schwarz, Robert J. Youngquist
  • Patent number: 4863114
    Abstract: A data cartridge includes a length of magnetic tape which is formed at each end with a first pattern of holes to enable identification of the end of the tape and a second pattern of holes located within the first pattern of holes and configured to provide a binary code to enable automatic identification of the cartridge type or tape type. The first pattern of holes is different at each end of the tape to further enable the automatic differentiation of one end of the tape from the other end.
    Type: Grant
    Filed: June 17, 1988
    Date of Patent: September 5, 1989
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: Gary D. Moeller, Steven R. Seeman, Theodore A. Schwarz
  • Patent number: 4647993
    Abstract: An improved rotary read/write head assembly is particularly suitable for use with a vertical format magnetic recording medium such as tape in a magnetic recording system. A rotary element of the assembly carries a plurality of main poles whose tips are at an edge of the rotary element and kept in substantially contacting relationship with the medium. Rotation of the element causes the pole tips to successively sweep across the medium and sequentially function as the main pole of a probe head.
    Type: Grant
    Filed: August 2, 1984
    Date of Patent: March 3, 1987
    Assignee: Magnetic Peripherals Inc.
    Inventors: Edward L. Schwarz, Theodore A. Schwarz
  • Patent number: 4636886
    Abstract: An improved rotary read/write head assembly is particularly suitable for use with a vertical format magnetic recording medium such as tape in a magnetic recording system. A rotary element of the assembly carries a plurality of main poles whose tips are at an edge of the rotary element and kept in substantially contacting relationship with the medium. Rotation of the element causes the pole tips to successively sweep across the medium and sequentially function as the main pole of a probe head.
    Type: Grant
    Filed: August 2, 1984
    Date of Patent: January 13, 1987
    Assignee: Magnetic Peripherals Inc.
    Inventor: Theodore A. Schwarz
  • Patent number: 4255772
    Abstract: A thin film magnetic head assembly incorporates a nonconductive magnetic substrate which serves as a first pole piece and a thin film magnetic layer for the second pole piece. A magnetoresistive (MR) element is disposed between the pole pieces. During the write mode, the MR element serves as a partial write turn to enhance the write signal current applied to a conductor means. During the read mode, the conductor means serves as a magnetic shield, and the transducing gap is effectively narrowed.
    Type: Grant
    Filed: June 29, 1979
    Date of Patent: March 10, 1981
    Assignee: International Business Machines Corporation
    Inventors: Henry S. Perez, Theodore A. Schwarz