Patents by Inventor Eiji Nakashio

Eiji Nakashio 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: 6563682
    Abstract: A second magnetic metal layer which is a magnetization free layer is successively covered with a non-magnetic metal layer and an anti-ferromagnetic layer. This enables to make the magnetization free layer a single magnetic domain and prevent generation of a domain wall. This prevents hysteresis and suppresses the Barkhausen noise.
    Type: Grant
    Filed: August 31, 2000
    Date of Patent: May 13, 2003
    Assignee: Sony Corporation
    Inventors: Junichi Sugawara, Eiji Nakashio, Hitoshi Kubota
  • Patent number: 6519123
    Abstract: A magnetic tunneling element in which the tunnel current flows reliably to exhibit a stable magnetic tunneling effect. The magnetic tunneling element includes a first magnetic layer, a tunnel barrier layer formed on the first magnetic layer, and a second magnetic layer formed on the tunnel barrier layer. The tunnel barrier layer is a metal film oxidized by inductively coupled oxygen plasma and a second magnetic layer is formed on the tunnel barrier layer.
    Type: Grant
    Filed: September 9, 1999
    Date of Patent: February 11, 2003
    Assignee: Sony Corporation
    Inventors: Junichi Sugawara, Eiji Nakashio, Seiji Kumagai, Yoshito Ikeda
  • Publication number: 20020131217
    Abstract: A multichannel magnetic head using magnetoresistive effect comprises a first magnetic shield and electrode (11), a second magnetic shield and electrode (12), the first and second magnetic shield and electrodes (11), (12) being opposed to each other, and a plurality of magnetoresistive effect type reproducing magnetic head elements arrayed between the first and second magnetic shield and electrodes (11) and (12), wherein the reproducing magnetic head elements formed of ferromagnetic tunnel type magnetoresistive effect elements are arrayed in parallel on at least the first magnetic shield and electrode (11). Electrodes on one side for applying a sense current to these ferromagnetic tunnel type magnetoresistive effect element in the direction crossing a tunnel barrier layer are constructed commonly by the first magnetic shield and led out as a common one terminal and thereby the number of terminals can be decreased.
    Type: Application
    Filed: March 7, 2002
    Publication date: September 19, 2002
    Applicant: Sony Corporation
    Inventors: Eiji Nakashio, Seiji Onoe, Junichi Sugawara
  • Patent number: 6452760
    Abstract: The width W1 of the lower shield thin film 3 and the width W2 of the upper shield thin film 7 are specified so that each of these widths is larger than the width W3 of the MR element 5 and is smaller than the contact width W4.
    Type: Grant
    Filed: October 12, 2000
    Date of Patent: September 17, 2002
    Assignee: Sony Corporation
    Inventors: Teruo Inaguma, Eiji Nakashio, Kazunori Onuma
  • Publication number: 20020114110
    Abstract: The part of an MR element 25 which lies close to a medium-facing surface 10a overlaps that part of a flux-guiding element 24 which lies remote from the medium-facing surface 10a, with a second gap film 23b interposed between the elements 24 and 25. Further, the MR element 25 overlaps the flux-guiding element 24 for a distance that falls within a range of 15 to 25% of the length of the MR height of the element 25 as measured in a direction perpendicular to the medium-facing surface 10a.
    Type: Application
    Filed: October 19, 2001
    Publication date: August 22, 2002
    Inventors: Toru Katakura, Takuji Matsuo, Eiji Nakashio, Junichi Sugawara, Seiji Onoe
  • Publication number: 20020114112
    Abstract: A magnetic tunnel element (1) including a plurality of ferromagnetic films (5, 9) laminated across an insulating film (11) formed of metal oxide films (6, 7, 8) and in which asymmetric tunnel barriers are formed along the direction in which the ferromagnetic films (5, 9) are laminated by this insulating film (11) (6, 7, 8). There are also constructed a thin-film magnetic head, a magnetic memory and a magnetic sensor, each of which includes the magnetic tunnel element (1). Since a magnetoresistive ratio can be suppressed from being lowered by decreasing a bias voltage dependency, there are provided a highly-reliable magnetic tunnel element which can obtain a high output when the magnetic tunnel element is applied to a thin-film magnetic head and the like and a method of manufacturing such a magnetic tunnel element. When a magnetic head, a magnetic memory and a magnetic sensor include this magnetic tunnel element, they become highly reliable and also become able to obtain a high output.
    Type: Application
    Filed: January 29, 2002
    Publication date: August 22, 2002
    Inventors: Eiji Nakashio, Seiji Onoe, Junichi Sugawara
  • Publication number: 20020021536
    Abstract: In a magnetic tunnel effect type magnetic head 20 having a magnetic tunnel junction element 26 sandwiched with conductive gap layers 25 and 27 between a pair of magnetic shielding layers 24 and 28, the conductive gap layers 25 and 27 are formed from at least one nonmagnetic metal layer containing a metal element selected from Ta, Ti, Cr, W, Mo, V, Nb and Zr. Therefore, the magnetic head 20 can have an improved face opposite to a magnetic recording medium.
    Type: Application
    Filed: July 2, 2001
    Publication date: February 21, 2002
    Applicant: SONY CORPORATION
    Inventors: Eiji Nakashio, Seiji Onoe, Junichi Sugawara
  • Publication number: 20020003684
    Abstract: A magnetic tunnel effect type magnetic head comprising a first soft magnetic conductive layer which is to provide a lower shielding layer 24, a metal oxide layer 25 and a first nonmagnetic conductive layer, formed on the first soft magnetic conductive layer, to provide a lower gap layer 26, a magnetic tunnel junction layer 34 formed on the first nonmagnetic conductive layer to provide a magnetic tunnel junction element 27, a second nonmagnetic conductive layer formed on the magnetic tunnel junction layer 34 to provide an upper gap layer 28; and a second soft magnetic conductive layer formed on the second nonmagnetic conductive layer to provide an upper shielding layer 29, the metal oxide layer 25 in the lower gap layer 26 being formed beneath at least the magnetic tunnel junction layer 27.
    Type: Application
    Filed: July 3, 2001
    Publication date: January 10, 2002
    Inventors: Eiji Nakashio, Seiji Onoe, Junichi Sugawara, Toru Katakura
  • Patent number: 6312840
    Abstract: A magnetic tunnelling element in which the tunnel current flows reliably in an insulating layer to exhibit a stable magnetic tunnelling effect. To this end, the magnetic tunnelling element at least includes a first magnetic layer, a tunnel barrier layer formed on the first magnetic layer and a second magnetic layer formed on the tunnel barrier layer. The tunnel current flows via the tunnel barrier layer between the first magnetic metal layer and the second magnetic metal layer. The surface of the first magnetic layer carrying the tunnel barrier layer has a surface roughness (Ra) of 0.3 nm or less.
    Type: Grant
    Filed: September 16, 1999
    Date of Patent: November 6, 2001
    Assignee: Sony Corporation
    Inventors: Seiji Kumagai, Eiji Nakashio, Junichi Sugawara, Yoshito Ikeda