Patents by Inventor Tatsuaki Ishida

Tatsuaki Ishida 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: 20020101669
    Abstract: A master information carrier comprises a substrate whose surface has an embossed pattern corresponding to an information signal. At least a surface of the protruding portion of the embossed pattern is made of a ferromagnetic material. A method for writing an information signal into a sheet or disk magnetic record medium with a ferromagnetic thin film or coating is performed by putting the surface of-the magnetic record medium into contact with the master information carrier so as to write a magnetized pattern corresponding to the embossed pattern of the master information carrier into the magnetic record medium.
    Type: Application
    Filed: March 26, 2002
    Publication date: August 1, 2002
    Applicant: Matsushita Electric Industrial Co., Ltd.
    Inventors: Tatsuaki Ishida, Ryuji Sugita, Kiyokazu Tohma, Keizou Miyata, Hiroshi Ryonai
  • Publication number: 20020101670
    Abstract: A master information carrier comprises a substrate whose surface has an embossed pattern corresponding to an information signal. At least a surface of the protruding portion of the embossed pattern is made of a ferromagnetic material. A method for writing an information signal into a sheet or disk magnetic record medium with a ferromagnetic thin film or coating is performed by putting the surface of the magnetic record medium into contact with the master information carrier so as to write a magnetized pattern corresponding to the embossed pattern of the master information carrier into the magnetic record medium.
    Type: Application
    Filed: March 26, 2002
    Publication date: August 1, 2002
    Applicant: Matsushita Electric Industrial Co., Ltd.
    Inventors: Tatsuaki Ishida, Ryuji Sugita, Kiyokazu Tohma, Keizou Miyata, Hiroshi Ryonai
  • Publication number: 20020089768
    Abstract: A master information carrier comprises a substrate whose surface has an embossed pattern corresponding to an information signal. At least a surface of the protruding portion of the embossed pattern is made of a ferromagnetic material. A method for writing an information signal into a sheet or disk magnetic record medium with a ferromagnetic thin film or coating is performed by putting the surface of the magnetic record medium into contact with the master information carrier so as to write a magnetized pattern corresponding to the embossed pattern of the master information carrier into the magnetic record medium.
    Type: Application
    Filed: February 26, 2002
    Publication date: July 11, 2002
    Applicant: Matsushita Electric Industrial Co., Ltd.
    Inventors: Tatsuaki Ishida, Ryuji Sugita, Kiyokazu Tohma, Kazunari Yoshimoto, Keizou Miyata, Hiroshi Ryonai
  • Publication number: 20020089769
    Abstract: A master information carrier comprises a substrate whose surface has an embossed pattern corresponding to an information signal. At least a surface of the protruding portion of the embossed pattern is made of a ferromagnetic material. A method for writing an information signal into a sheet or disk magnetic record medium with a ferromagnetic thin film or coating is performed by putting the surface of the magnetic record medium into contact with the master information carrier so as to write a magnetized pattern corresponding to the embossed pattern of the master information carrier into the magnetic record medium.
    Type: Application
    Filed: February 26, 2002
    Publication date: July 11, 2002
    Applicant: Matsushita Electric Industrial Co., Ltd.
    Inventors: Tatsuaki Ishida, Ryuji Sugita, Kiyokazu Tohma, Kazunari Yoshimoto, Keizou Miyata, Hiroshi Ryonai
  • Publication number: 20020080507
    Abstract: A magnetic transcription device for transcribing information signals of a master information carrier in a magnetic recording medium by applying a magnetic field generated by magnetic field generating means to a contact body obtained by contacting the master information carrier having a base on which ferromagnetic bodies corresponding to the information signals are formed with a magnetic recording medium having a ferromagnetic layer, wherein the magnetic recording medium includes driving means for adjusting a distance between the magnetic field generating means and the contact body while rotating the magnetic field generating means relative to the contact body.
    Type: Application
    Filed: December 3, 2001
    Publication date: June 27, 2002
    Applicant: Matsushita Electric Industrial Co., Ltd
    Inventors: Kouji Taniguchi, Kaoru Matsuoka, Taizou Hamada, Hideyuki Hashi, Yasuaki Ban, Tatsuaki Ishida
  • Publication number: 20020075583
    Abstract: A master information carrier comprises a substrate whose surface has an embossed pattern corresponding to an information signal. At least a surface of the protruding portion of the embossed pattern is made of a ferromagnetic material. A method for writing an information signal into a sheet or disk magnetic record medium with a ferromagnetic thin film or coating is performed by putting the surface of the magnetic record medium into contact with the master information carrier so as to write a magnetized pattern corresponding to the embossed pattern of the master information carrier into the magnetic record medium.
    Type: Application
    Filed: December 21, 2001
    Publication date: June 20, 2002
    Applicant: Matsushita Electric Industrial Co., Ltd.
    Inventors: Tatsuaki Ishida, Ryuji Sugita, Kiyokazu Tohma, Kazunari Yoshimoto, Keizou Miyata, Hiroshi Ryonai
  • Publication number: 20020048106
    Abstract: A high-level region and a low-level region are formed on a surface of a nonmagnetic base member, in which high-level region is formed a ferromagnetic thin film pattern which corresponds to a preformat information signal, in such a structure that a flow promoting shape of such a shape (e.g., smooth curved shape, polygonal shape) that inhibits the stagnation of a flow of a detergent to promote the flow in order to prevents sticking and residing of foreign matter contained in the detergent is formed at an area where the detergent is liable to stagnate in the high-level region, i.e. at an inner radial portion of a disk-shaped mater information carrier.
    Type: Application
    Filed: October 23, 2001
    Publication date: April 25, 2002
    Applicant: Matsushita Electric Industrial Co., Ltd
    Inventors: Keizo Miyata, Hideyuki Hashi, Tatsuaki Ishida
  • Patent number: 6347016
    Abstract: A master information carrier comprises a substrate whose surface has an embossed pattern corresponding to an information signal. At least a surface of the protruding portion of the embossed pattern is made of a ferromagnetic material. A method for writing an information signal into a sheet or disk magnetic record medium with a ferromagnetic thin film or coating is performed by putting the surface of the magnetic record medium into contact with the master information carrier so as to write a magnetized pattern corresponding to the embossed pattern of the master information carrier into the magnetic record medium.
    Type: Grant
    Filed: July 13, 1998
    Date of Patent: February 12, 2002
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Tatsuaki Ishida, Ryuji Sugita, Kiyokazu Tohma, Keizou Miyata, Hiroshi Ryonai
  • Patent number: 6242085
    Abstract: An underlying layer is formed of Cr or the like on a glass substrate, and a magnetic layer is formed on the underlying layer by simultaneously sputtering a magnetic substance and a non-magnetic substance that does not form a solid solution with the magnetic substance in an atmosphere having a pressure of 30 mTorr to 75 mTorr. The magnetic recording medium comprises clusters, each of which is formed of aggregated magnetic grains, and a non-magnetic substance between the clusters. Each magnetic grain has a grain diameter of 5 nm to 20 nm. An average gap between the clusters is 1.5 nm to 5 nm. Thus, the present invention can provide a magnetic recording medium having a high S/N ratio that is suitable for high density recording.
    Type: Grant
    Filed: September 15, 1998
    Date of Patent: June 5, 2001
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Hiroshi Ryonai, Tatsuaki Ishida, Kiyokazu Tohma, Keizou Miyata, Taizou Hamada
  • Patent number: 6088178
    Abstract: An apparatus for recording and reproducing a signal using a thin film magnetic tape as a medium and using ring type magnetic heads for recording and reproducing the signal, wherein the gap length of the magnetic head for reproducing is larger than the gap length of the magnetic head for recording. Maximum recording and reproducing performance is achieved by implementing separate recording and reproducing heads.
    Type: Grant
    Filed: December 6, 1996
    Date of Patent: July 11, 2000
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Tatsuaki Ishida, Ryuji Sugita, Hiroyuki Hasegawa
  • Patent number: 5912783
    Abstract: In a magnetic recording and reproduction apparatus wherein signals are recorded with a ring-type magnetic head to a magnetic recording medium having axis of easy magnetization oblique with respect to a film normal of a magnetic layer of the medium A recording magnetic field generated by the magnetic head is asymmetric with respect to a center line of a gap of the magnetic circuit, and the recording magnetic field in the magnetic layer around a leading edge of the magnetic head is inclined at the same side as the axis of easy magnetization in the magnetic field in a normal plane of the magnetic layer including a direction of relative movement of the magnetic head to the magnetic recording medium when signals are recorded to the medium. Thus, signals can be recorded at a high density. Various types of magnetic head for generating asymmetric magnetic field are provided.
    Type: Grant
    Filed: December 10, 1996
    Date of Patent: June 15, 1999
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Tatsuaki Ishida, Ryuji Sugita, Noriyasu Echigo, Hiroyuki Hasegawa
  • Patent number: 5901012
    Abstract: In a magnetic recording and reproduction apparatus wherein signals are recorded with a ring-type magnetic head to a magnetic recording medium having axis of easy magnetization oblique with respect to a film normal of a magnetic layer of the medium. A recording magnetic field generated by the magnetic head is asymmetric with respect to a center line of a gap of the magnetic circuit, and the recording magnetic field in the magnetic layer around a leading edge of the magnetic head is inclined at the same side as the axis of easy magnetization in the magnetic field in a normal plane of the magnetic layer including a direction of relative movement of the magnetic head to the magnetic recording medium when signals are recorded to the medium. Thus, signals can be recorded at a high density. Various types of magnetic head for generating asymmetric magnetic field are provided.
    Type: Grant
    Filed: July 18, 1997
    Date of Patent: May 4, 1999
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Tatsuaki Ishida, Ryuji Sugita, Noriyasu Echigo
  • Patent number: 5691008
    Abstract: A magnetic recording medium fabrication device includes a cooling drum around which a substrate runs while being cooled thereby, an ion gun arranged upstream to a vapor deposition station for kicking out particles absorbed on the plane of the substrate, a cooling body arranged between the cooling drum and ion gun for absorbing kicked out particles and a vapor deposition means for depositing a magnetic layer on the substrate at the vapor deposition station. The magnetic particles forming the magnetic layer that have residual magnetization vectors within .+-.10.degree. of the easy axis direction including the magnetic anisotropy of the medium are greater than or equal to 70% and less than or equal to 90% of the total amount of magnetic particles.
    Type: Grant
    Filed: October 12, 1995
    Date of Patent: November 25, 1997
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Kiyokazu Thoma, Kazunari Yoshimoto, Ryuji Sugita, Tatsuaki Ishida
  • Patent number: 5679410
    Abstract: A thin film magnetic recording medium is manufactured with vacuum deposition or sputtering technique. One or more reflectors are provided between the substrate and an evaporation source around a path through which evaporated atoms travel onto a substrate. When a thin film is deposited on a substrate, the one or more reflectors are heated above a melting point of an evaporation material to reflect evaporated atoms arriving them. Thus, atoms reflected by the one or more reflectors also contribute to deposition of a thin film as well as evaporated atoms arriving directly from the evaporation source, and deposition efficiency is improved. Such a reflector is also used to limit a boundary or the path through which evaporated atoms travel onto a substrate. Then, a range of incident angles of evaporated atoms onto the substrate is kept the same for a long time on deposition, and characteristics of the thin film are stable.
    Type: Grant
    Filed: June 5, 1995
    Date of Patent: October 21, 1997
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Ryuji Sugita, Kiyokazu Tohma, Tatsuaki Ishida, Kazunari Yoshimoto
  • Patent number: 5679166
    Abstract: A magnetic recording medium fabrication device includes a cooling drum around which a substrate runs while being cooled thereby, an ion gun arranged upstream to a vapor deposition station for kicking out particles absorbed on the plane of the substrate, a cooling body arranged between the cooling drum and ion gun for absorbing kicked out particles and a vapor deposition device for depositing a magnetic layer on the substrate at the vapor deposition station. The magnetic particles forming the magnetic layer that have residual magnetization vectors within .+-.10.degree. of the easy axis direction including the magnetic anisotropy of the medium are greater than or equal to 70% and less than or equal to 90% of the total amount of magnetic particles.
    Type: Grant
    Filed: October 12, 1995
    Date of Patent: October 21, 1997
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Kiyokazu Thoma, Kazunari Yoshimoto, Ryuji Sugita, Tatsuaki Ishida
  • Patent number: 5665460
    Abstract: A magnetic recording medium having a first magnetic layer positioned on a substrate and a second magnetic layer positioned on the first magnetic layer, wherein the first magnetic layer is a film of a partial oxide based on Co in which a growth direction of crystalline grain is substantially normal to the film plane and the easy magnetization axis is in a direction of the film plane or direction substantially normal to the film plane, and the second magnetic layer is a film of a partial oxide based on Co in which the growth direction of crystalline grain is diagonally inclined to the line normal to the film plane and the easy magnetization axis is diagonally inclined to the line normal to the film plane.
    Type: Grant
    Filed: October 26, 1995
    Date of Patent: September 9, 1997
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Ryuji Sugita, Kiyokazu Tohma, Tatsuaki Ishida, Kazunari Yoshimoto
  • Patent number: 5569523
    Abstract: A magnetic recording medium fabrication device includes a cooling drum around which a substrate runs while being cooled thereby, an ion gun arranged upstream to a vapor deposition station for kicking out particles absorbed on the plane of the substrate, a cooling body arranged between the cooling drum and ion gun for absorbing kicked out particles and a vapor deposition means for depositing a magnetic layer on the substrate at the vapor deposition station. The magnetic particles forming the magnetic layer that have residual magnetization vectors within .+-.10.degree. of the easy axis direction including the magnetic anisotropy of the medium are greater than or equal to 70% and less than or equal to 90% of the total amount of magnetic particles.
    Type: Grant
    Filed: February 28, 1995
    Date of Patent: October 29, 1996
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Kiyokazu Thoma, Kazunari Yoshimoto, Ryuji Sugita, Tatsuaki Ishida
  • Patent number: 5554440
    Abstract: A magnetic tape having a polymer substrate and a magnetic layer which is formed directly on a surface of the substrate or on a primer layer formed on the substrate and contains cobalt, oxygen and optionally nickel, in which a coercive force is at least 120 kA/m and a squareness ratio is at least 0.
    Type: Grant
    Filed: September 9, 1993
    Date of Patent: September 10, 1996
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Tatsuaki Ishida, Ryuji Sugita, Kiyokazu Tohma, Yasuaki Ban
  • Patent number: 5549936
    Abstract: In a manufacturing method of a magnetic recording medium with a vacuum deposition, two shielding members are provided above a substrate for defining an aperture. An evaporation source is located at a position wherein evaporated atoms from an evaporation material can adhere to a moving substrate through the aperture. The substrate is moved while a material in the evaporation source is irradiated at two evaporation portions with two electron beams along a moving direction of the substrate to form a magnetic layer. Thus, curving of columnar gains formed in the magnetic layer is suppressed or crystal orientation is enhanced, and magnetic read/write characteristics are improved. Further, a productivity is improved because the aperture can be enlarged than previously by using the two evaporation portions.
    Type: Grant
    Filed: October 18, 1994
    Date of Patent: August 27, 1996
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Kiyokazu Tohma, Kazunari Yoshimoto, Ryuji Sugita, Tatsuaki Ishida
  • Patent number: 5534324
    Abstract: A magnetic recording medium has a cobalt-based first magnetic layer and a cobalt-based second magnetic layer which are formed on a substrate of high polymer by vacuum evaporation. In order to have a high reproducing output and a high S/N ratio, the first magnetic layer has high oxygen density area which is arranged at a vicinity of the second magnetic layer, and the second magnetic layer has high oxygen density area which is arranged at a vicinity of the first magnetic layer.
    Type: Grant
    Filed: November 10, 1993
    Date of Patent: July 9, 1996
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Ryuji Sugita, Kiyokazu Tohma, Tatsuaki Ishida, Yasuaki Ban