Patents by Inventor Kiyokazu Tohma

Kiyokazu Tohma 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: 6961196
    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: March 25, 2003
    Date of Patent: November 1, 2005
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Tatsuaki Ishida, Ryuji Sugita, Kiyokazu Tohma, Kazunari Yoshimoto, Keizou Miyata, Hiroshi Ryonai
  • Patent number: 6909565
    Abstract: A magnetic transfer method includes a first step (ST103) of preparing a magnetic disk, a second step (ST105) of forming a layer of lubricant on the magnetic disk, a third step (ST108) of bringing a surface of the magnetic layer on the magnetic disk into close contact with a magnetic transfer master having a magnetic film formed on at least one side and magnetically transferring a pattern of the magnetic film on the magnetic transfer master onto the surface of the magnetic disk through application of an external magnetic field, and a fourth step (ST104, ST106) of burnishing at least a surface of the magnetic disk that comes into contact with the magnetic transfer master. The first step, the fourth step, the second step, the fourth step, and the third step are performed in the stated order.
    Type: Grant
    Filed: November 20, 2003
    Date of Patent: June 21, 2005
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Hideyuki Hashi, Taizou Hamada, Tatsuaki Ishida, Kiyokazu Tohma
  • Patent number: 6898032
    Abstract: A magnetic transfer method includes a first step (ST103) of preparing a magnetic disk, a second step (ST105) of forming a layer of lubricant on the magnetic disk, a third step (ST108) of bringing a surface of the magnetic layer on the magnetic disk into close contact with a magnetic transfer master having a magnetic film formed on at least one side and magnetically transferring a pattern of the magnetic film on the magnetic transfer master onto the surface of the magnetic disk through application of an external magnetic field, and a fourth step (ST104, ST106) of burnishing at least a surface of the magnetic disk that comes into contact with the magnetic transfer master. The first step, the fourth step, the second step, the fourth step, and the third step are performed in the stated order.
    Type: Grant
    Filed: March 28, 2001
    Date of Patent: May 24, 2005
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Hideyuki Hashi, Taizou Hamada, Tatsuaki Ishida, Kiyokazu Tohma
  • Patent number: 6858328
    Abstract: A master information carrier with excellent durability is provided, for the use of static and a real lump-sum recording of digital information signals on magnetic recording medium. The master information carrier comprises a non-magnetic substrate on which a ferromagnetic film is disposed with an embossed pattern. Protrusions of the embossed pattern correspond to a disposition of the digital information signals. Recessed portions of the embossed pattern of the ferromagnetic film are filled with non-magnetic solid material. Alternately, A non-magnetic substrate has an embossed pattern and recessed portions of the embossed pattern correspond to a disposition of the digital information signals. A ferromagnetic film is filled in the recessed portions of the embossed pattern.
    Type: Grant
    Filed: March 18, 1999
    Date of Patent: February 22, 2005
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Tatsuaki Ishida, Kiyokazu Tohma, Keizo Miyata, Yoriko Takai, Taizou Hamada, Hiroshi Ryonai
  • Patent number: 6858329
    Abstract: A master disc capable of conducting a preformat recording by a magnetic transcription without causing any unevenness over an entire magnetic disc is provided. The master disc is provided with a radial land portion where an array of ferromagnetic thin films is formed and a concave portion against the land portion. The land portion and the concave portion are formed such that the land portion is joined with the surface of the magnetic disc when the present magnetic disc is overlapped on the magnetic disc, and that the concave portion is not contacted with the surface of the magnetic disc, and also that a space surrounded by the surface of the magnetic disc and the concave portion is open to air at a peripheral end portion of the magnetic disc.
    Type: Grant
    Filed: March 29, 2001
    Date of Patent: February 22, 2005
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Taizou Hamada, Hideyuki Hashi, Tatsuaki Ishida, Nobuyuki Komura, Yasuaki Ban, Keizo Miyata, Kiyokazu Tohma
  • Publication number: 20040109252
    Abstract: A magnetic transfer method includes a first step (ST103) of preparing a magnetic disk, a second step (ST105) of forming a layer of lubricant on the magnetic disk, a third step (ST108) of bringing a surface of the magnetic layer on the magnetic disk into close contact with a magnetic transfer master having a magnetic film formed on at least one side and magnetically transferring a pattern of the magnetic film on the magnetic transfer master onto the surface of the magnetic disk through application of an external magnetic field, and a fourth step (ST104, ST106) of burnishing at least a surface of the magnetic disk that comes into contact with the magnetic transfer master. The first step, the fourth step, the second step, the fourth step, and the third step are performed in the stated order.
    Type: Application
    Filed: November 20, 2003
    Publication date: June 10, 2004
    Applicant: Matsushita Electric Industrial Co., Ltd.
    Inventors: Hideyuki Hashi, Taizou Hamada, Tatsuaki Ishida, Kiyokazu Tohma
  • Publication number: 20040100710
    Abstract: A magnetic transfer method includes a first step (ST103) of preparing a magnetic disk, a second step (ST105) of forming a layer of lubricant on the magnetic disk, a third step (ST108) of bringing a surface of the magnetic layer on the magnetic disk into close contact with a magnetic transfer master having a magnetic film formed on at least one side and magnetically transferring a pattern of the magnetic film on the magnetic transfer master onto the surface of the magnetic disk through application of an external magnetic field, and a fourth step (ST104, ST106) of burnishing at least a surface of the magnetic disk that comes into contact with the magnetic transfer master. The first step, the fourth step, the second step, the fourth step, and the third step are performed in the stated order.
    Type: Application
    Filed: November 20, 2003
    Publication date: May 27, 2004
    Applicant: Matsushita Electric Industrial Co., Ltd.
    Inventors: Hideyuki Hashi, Taizou Hamada, Tatsuaki Ishida, Kiyokazu Tohma
  • Patent number: 6714367
    Abstract: A master information carrier has a shape pattern corresponding to an information signal array to be recorded on a magnetic recording medium, and the shape pattern is provided by arraying a ferromagnetic thin film deposited on a nonmagnetic substrate surface. The ferromagnetic thin film is either a soft magnetic film or semihard magnetic film having not more than 40 kA/m coercive force in track length direction of the information signals, and residual magnetization of the ferromagnetic thin film in the track length direction of the information signals is greater than coercive force of the magnetic recording medium. As a result, a master information carrier with superior magnetic recording performance can be obtained.
    Type: Grant
    Filed: August 7, 2000
    Date of Patent: March 30, 2004
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Tatsuaki Ishida, Hiroshi Ryonai, Nobuyuki Komura, Keizo Miyata, Kiyokazu Tohma
  • Publication number: 20030236974
    Abstract: A content receiving and distributing system enables content to be received from or distributed to a user securely, simply, and promptly. The system includes a server that stores content data, a data receiving and distributing apparatus connected to the server, and a user terminal 15 linked to the data receiving and distributing apparatus via a network for receiving and distributing content data. A storage device provided in each of the data receiving and distributing apparatus and the user terminal stores a reception and distribution program required to receive and distribute content data. The reception and distribution program is stored simultaneously with the content data in the storage device provided in the user terminal. Content data is received and distributed on the basis of a user request input to the user terminal for downloading or uploading of content data from or to the data receiving and distributing apparatus.
    Type: Application
    Filed: June 19, 2003
    Publication date: December 25, 2003
    Inventors: Kiminori Sato, Akihiro Otsuki, Tatsuro Ishida, Kiyokazu Tohma, Kaoru Matsuoka
  • Publication number: 20030184896
    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 25, 2003
    Publication date: October 2, 2003
    Applicant: Matsushita Electric Industrial Co., Ltd.
    Inventors: Tatsuaki Ishida, Ryuji Sugita, Kiyokazu Tohma, Kazunari Yoshimoto, Keizou Miyata, Hiroshi Ryonai
  • Patent number: 6611388
    Abstract: A master-information magnetic recording apparatus for recording preformat information signals into a magnetic recording medium using a ferromagnetic film pattern formed on a master information carrier, in which the pattern corresponds to the preformat information signals. With the master information carrier in contact with the magnetic recording medium, the ferromagnetic film pattern is magnetized by a magnetic field applying device. Thus, the preformat information signals are recorded into the magnetic recording medium. The magnetic field applying device is so constructed that the direction of magnetizing the ferromagnetic film pattern is perpendicular to a track-scanning orbit of a magnetic head in a recording and reproducing apparatus in which the magnetic recording medium is installed. It enables the magnetic head to gain sufficient reproduction amplitude for track-scanning for reproducing the information signals.
    Type: Grant
    Filed: September 13, 2000
    Date of Patent: August 26, 2003
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Keizo Miyata, Tatsuaki Ishida, Taizou Hamada, Kiyokazu Tohma, Hiroshi Ryonai
  • Patent number: 6606209
    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: March 26, 2002
    Date of Patent: August 12, 2003
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Tatsuaki Ishida, Ryuji Sugita, Kiyokazu Tohma, Keizou Miyata, Hiroshi Ryonai
  • Patent number: 6606208
    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: February 26, 2002
    Date of Patent: August 12, 2003
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Tatsuaki Ishida, Ryuji Sugita, Kiyokazu Tohma, Kazunari Yoshimoto, Keizou Miyata
  • Patent number: 6590727
    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: December 21, 2001
    Date of Patent: July 8, 2003
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Tatsuaki Ishida, Ryuji Sugita, Kiyokazu Tohma, Kazunari Yoshimoto, Keizou Miyata
  • Patent number: 6587290
    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: February 26, 2002
    Date of Patent: July 1, 2003
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Tatsuaki Ishida, Ryuji Sugita, Kiyokazu Tohma, Kazunari Yoshimoto, Keizou Miyata
  • Patent number: 6567227
    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: March 26, 2002
    Date of Patent: May 20, 2003
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Tatsuaki Ishida, Ryuji Sugita, Kiyokazu Tohma, Kazunari Yoshimoto, Keizou Miyata, Hiroshi Ryonai
  • Patent number: 6529341
    Abstract: A magnetic disk for a magnetic recording/reproduction device includes a magnetic head, wherein a magnetization bit-pattern corresponding to a preformat information signal is recorded beforehand on the magnetic disk, wherein the magnetization bit-pattern is recorded by contacting a surface of the magnetic disk with a surface of a master information carrier having a pattern corresponding to the preformat information signal, and a portion of the magnetization bit-pattern corresponding to at least one signal selected from a clock signal and a synchronous signal has a recording width that is larger than a recording track width of the magnetic head in a radial direction of the magnetic disk.
    Type: Grant
    Filed: July 25, 2000
    Date of Patent: March 4, 2003
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Tatsuaki Ishida, Taizou Hamada, Kiyokazu Tohma, Hiroshi Ryonai, Keizou Miyata
  • Publication number: 20030011913
    Abstract: A magnetic transfer method includes a first step (ST103) of preparing a magnetic disk, a second step (ST105) of forming a layer of lubricant on the magnetic disk, a third step (ST108) of bringing a surface of the magnetic layer on the magnetic disk into close contact with a magnetic transfer master having a magnetic film formed on at least one side and magnetically transferring a pattern of the magnetic film on the magnetic transfer master onto the surface of the magnetic disk through application of an external magnetic field, and a fourth step (ST104, ST106) of burnishing at least a surface of the magnetic disk that comes into contact with the magnetic transfer master. The first step, the fourth step, the second step, the fourth step, and the third step are performed in the stated order.
    Type: Application
    Filed: August 6, 2002
    Publication date: January 16, 2003
    Inventors: Hideyuki Hashi, Taizou Hamada, Tatsuaki Ishida, Kiyokazu Tohma
  • Publication number: 20020150794
    Abstract: A master disc capable of conducting a preformat recording by a magnetic transcription without causing any unevenness over an entire magnetic disc is provided. The master disc is provided with a radial land portion where an array of ferromagnetic thin films is formed and a concave portion against the land portion. The land portion and the concave portion are formed such that the land portion is joined with the surface of the magnetic disc when the present magnetic disc is overlapped on the magnetic disc, and that the concave portion is not contacted with the surface of the magnetic disc, and also that a space surrounded by the surface of the magnetic disc and the concave portion is open to air at a peripheral end portion of the magnetic disc.
    Type: Application
    Filed: April 30, 2002
    Publication date: October 17, 2002
    Inventors: Taizou Hamada, Hideyuki Hashi, Tatsuaki Ishida, Nobuyuki Komura, Yasuaki Ban, Keizo Miyata, Kiyokazu Tohma
  • Patent number: 6466385
    Abstract: A magnetic disk apparatus has: a head (2) that performs data recording and playback while moving relative to a magnetic disk (26) rotating at the prescribed speed; an actuator (3) that positions said head relative to said magnetic disk (26); and a controller (4) that detects the position of said head by means of servo sector that have positioning information recorded magnetically on said magnetic disk (1) and performs control to position said actuator (3) by means of this detection signal, wherein said magnetic disk (1) has at least a part in which the arrangement of tracks is spiral. The magnetic patterns on the disk include a servo sector and a data sector both formed on the same spiral track. The servo sector includes burst patterns for servo control.
    Type: Grant
    Filed: December 7, 2000
    Date of Patent: October 15, 2002
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Yoshio Umeda, Ryosuke Shimizu, Syuichi Yoshida, Tatsuaki Ishida, Kiyokazu Tohma, Keizo Miyata