Patents by Inventor Junzo Toda

Junzo Toda 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: 6046890
    Abstract: A magnetoresistive head of the present invention is not easily damaged by electrostatic discharge, and is easy to manufacture. A magnetoresistance effect element is interposed between upper and lower shields composed of soft magnetic material through first and second gaps composed of an insulating material. The lower shield is connected to a slider via a slider protective film, which is an insulating substance. The magnetoresistive head is constructed so that a capacity Cg between the magnetoresistance effect element and the lower shield is 6.3 or more times a capacity between the lower shield and the slider by using a material (e.g., silicon carbide) exhibiting a large relative dielectric constant as, e.g., a second gap material.
    Type: Grant
    Filed: January 15, 1998
    Date of Patent: April 4, 2000
    Assignee: Fujitsu Limited
    Inventors: Kenichiro Yamada, Yuji Uehara, Junzo Toda
  • Patent number: 5995339
    Abstract: A magnetoresistive head includes a magnetoresistive element set back from the front end face of the head confronting a record medium for converting changes in a signal magnetic field leaking out from the record track of the record medium into changes in resistance. The magnetoresistive element is connected to a pair of terminals and a sense region is defined between both the terminals. The magnetoresistive element is magnetically coupled to a front flux guide, one end of which is exposed in the front end face of the head, at the other end of the same. The front flux guide is virtually in the form of a rectangle elongated in the direction of the width of the record track of the record medium so as to exceed the sense region of the magnetoresistive element.
    Type: Grant
    Filed: January 27, 1997
    Date of Patent: November 30, 1999
    Assignee: Fujitsu Limited
    Inventors: Takao Koshikawa, Yoshinori Ohtsuka, Yuji Uehara, Junzo Toda, Yoshifumi Mizoshita
  • Patent number: 5792546
    Abstract: A magneto-resistive head is provided with a substrate, a lower shield layer made of a Fe-system magnetic material and provided above the substrate, and a non-magnetic insulator layer provided above the lower shield layer. The non-magnetic insulator layer has a function of suppressing deterioration of surface roughness of the lower shield layer when subjected to an annealing process under a magnetic field in order to improve magnetic characteristics of the lower shield layer to desired magnetic characteristics.
    Type: Grant
    Filed: August 12, 1994
    Date of Patent: August 11, 1998
    Assignee: Fujitsu Limited
    Inventors: Michiaki Kanamine, Hitoshi Kanai, Junichi Kane, Junzo Toda, Yuji Uehara
  • Patent number: 5774308
    Abstract: A thin film inductive head for use in writing/reading magnetic signals in a magnetic disk drive or a magnetic tape unit, comprises two magnetic cores formed of respective magnetic layers, said two magnetic layers putting conductor coils therebetween in a vertical direction, front end portions thereof opposing to each other via a gap layer, a part of said front end portion of one magnetic layer having high saturation magnetic flux density rather than a remaining part thereof.
    Type: Grant
    Filed: October 15, 1996
    Date of Patent: June 30, 1998
    Assignee: Fujitsu Limited
    Inventors: Yoshinori Ohtsuka, Junzo Toda
  • Patent number: 5463517
    Abstract: The ends of lead conductor layers, which ends mark the boundaries of a signal detection area are made substantially perpendicular in the vicinity of a magnetoresistance element, and are sloped in the vicinity of an upper shield so that the lead conductor layers are thicker away from the signal detection area; a recording gap is a regularly shaped gap at least over a spatial range corresponding to a signal detection area.
    Type: Grant
    Filed: January 28, 1994
    Date of Patent: October 31, 1995
    Assignee: Fujitsu Limited
    Inventors: Junzo Toda, Susumu Aoyama
  • Patent number: 4546398
    Abstract: A perpendicular magnetic recording and reproducing head, including: a spiral coil of at least one electrically conductive thin film; and a main pole of a first thin magnetic film having an end for recording and reproducing information, the main pole and the spiral coil being electromagnetically coupled to each other. A perpendicular magnetic head such as this can be easily manufactured, can be adapted not only to floppy disks but also to rigid disks, is suitable for high-frequency operation, and has an improved recording/reproducing efficiency.
    Type: Grant
    Filed: July 30, 1982
    Date of Patent: October 8, 1985
    Assignee: Fujitsu Limited
    Inventors: Junzo Toda, Masao Hiyane