Patents by Inventor Taizou Hamada

Taizou Hamada 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: 6646820
    Abstract: A master information carrier (2) with an arranged pattern formed of a ferromagnetic film in a shape corresponding to information signals is superposed on a magnetic recording medium (1) and the arranged pattern formed of a ferromagnetic film is magnetized with a magnetizing head (6), thus transfer-recording the arranged pattern into the magnetic recording medium as a magnetized pattern. The magnetizing head includes an annular magnetic circuit with a gap, and a strength of a magnetic field applied to the master information carrier by magnetic flux leaking from portions other than the gap is set to be 20% or less of that of a magnetic field applied to the master information carrier by magnetic flux leaking from the gap. Quality deterioration due to various conditions during recording can be prevented and uniform recording with less variation depending on position on the magnetic recording medium is achieved.
    Type: Grant
    Filed: July 3, 2001
    Date of Patent: November 11, 2003
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Tatsuaki Ishida, Taizou Hamada, Hideyuki Hashi, Keizo Miyata, Yasuaki Ban, Hiromi Kita
  • Publication number: 20030172956
    Abstract: A cleaning method preventing foreign matter attached to a brush from being transferred back to a magnetic transfer carrier by removing foreign matter attached to a cleaning tool such as the brush with a dummy carrier having a recess equivalent to that on a surface of the magnetic transfer carrier.
    Type: Application
    Filed: February 20, 2003
    Publication date: September 18, 2003
    Inventors: Hideyuki Hashi, Keizo Miyata, Taizou Hamada
  • 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
  • Publication number: 20030142427
    Abstract: The master information recording apparatus 100 includes a master information carrier, a master information carrier facing member, and a magnetic field applying member. A ferromagnetic thin film pattern formed on the surface of the master information carrier includes not less than two kinds of different patterns each having a different pattern angle showing an angle with respect to the direction of the relative movement between a magnetic head and a rotating magnetic recording medium. The magnetic field applying unit applies a magnetic field along the direction, which is perpendicular to the direction shown by an angle that is smaller than the pattern angle of the maximum pattern and larger than the minimum pattern angle of the pattern among the not less than two kinds of patterns.
    Type: Application
    Filed: January 30, 2003
    Publication date: July 31, 2003
    Applicant: Matsushita Electric Industrial Co., Ltd.
    Inventors: Yasuaki Ban, Keizo Miyata, Taizou Hamada, Kouji Taniguchi, Masaya Sakaguchi
  • Publication number: 20030081345
    Abstract: The data row Pw(i) of phase information obtained by reading preformatted phase patterns on an information recording medium by the head consists of the remainders obtained by dividing the data row of the phase information indicating the original track location by 2&pgr;.
    Type: Application
    Filed: October 23, 2002
    Publication date: May 1, 2003
    Applicant: Matsushita Electric Industrial Co., Ltd
    Inventors: Taizou Hamada, Yasuaki Ban
  • Publication number: 20030068462
    Abstract: In a manufacturing method for a magnetic recording medium, when the length of a ferromagnetic thin film on a master information carrier corresponding to the length between a pair of magnetization transition regions adjacent to each other is A in magnetization information recorded onto a magnetic recording medium, the film thickness of the ferromagnetic thin film is t and A/t is k, k is set from not less than 0.8 to not more than 8.
    Type: Application
    Filed: October 2, 2002
    Publication date: April 10, 2003
    Applicant: Matsushita Electric Industrial Co., Ltd.
    Inventors: Taizou Hamada, Tatsuaki Ishida, Yasuaki Ban
  • 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: 20020159174
    Abstract: Instead of directly performing defect inspection using a master information carrier, an inspection substrate is prepared to then bring the master information carrier in close contact therewith, to thereby transfer a defect on the master information carrier to the inspection substrate, thus indirectly inspecting any defect of the master information carrier on the inspection substrate. Defect inspection is performed on the first-state inspection substrate before close contacting, so that a defect inspection result on the second-state inspection substrate after close contacting and that on the first-state inspection substrate are compared to each other.
    Type: Application
    Filed: April 17, 2002
    Publication date: October 31, 2002
    Applicant: Matsushita Electric Industrial Co. Ltd.
    Inventors: Hideyuki Hashi, Taizou Hamada, Tatsuaki Ishida
  • 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
  • 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: 20020063981
    Abstract: A master information carrier is made to overlap with a magnetic recording medium being a magnetic recording medium in an adhering state, and a pattern corresponding to information signals on the master information carrier is transferred to the magnetic recording medium, thereby magnetically transferring a magnetized pattern of information signals to the magnetic recording medium. Thereafter, an urging force to the magnetic recording medium side is applied to the master information carrier, and in the urging force applied state, a gas under pressure is supplied on the adhering/joining surfaces of the master information carrier and the magnetic recording medium, thereby releasing the adhering state of the master information carrier and the magnetic recording medium. Then, the application of the urging force is released to continue the supply of the gas under pressure, thereby pulling away the master information carrier from the magnetic recording medium and moving them.
    Type: Application
    Filed: November 28, 2001
    Publication date: May 30, 2002
    Applicant: Matsushita Electric Industrial Co., Ltd.
    Inventors: Taizou Hamada, Hideyuki Hashi
  • Publication number: 20020030908
    Abstract: Within a casing accommodating members for performing magnetic transfer of signals from one medium to another, a plurality of suction ports are fixedly disposed at various locations. Resin tubes connect the suction ports to respective particle counters for the measurement of particles at each location, whereby the source of particles is locatable.
    Type: Application
    Filed: June 12, 2001
    Publication date: March 14, 2002
    Inventors: Nobuhide Matsuda, Taizou Hamada, Hideyuki Hashi, Hiroshi Hashida, Eiichi Fujisawa, Shoichi Seki
  • Publication number: 20020015245
    Abstract: Surface of a transfer disk for performing magnetic transfer is repeatedly contacted or separated relative to a cleaning disk having a smaller hardness than the surface, thereby removing a foreign matter on the surface of the transfer disk.
    Type: Application
    Filed: June 13, 2001
    Publication date: February 7, 2002
    Inventors: Hideyuki Hashi, Taizou Hamada, Nobuhide Matsuda, Mitsuo Kobayashi
  • 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: 5602702
    Abstract: A magnetic recording/reproducing apparatus according to the present invention includes: a fixed cylinder; a rotary cylinder rotatably supported by the fixed cylinder, the rotary cylinder including a disk-shaped magnet in which first areas having a first pole and second areas having a second pole opposite to the first pole are alternately arranged; and a head chip attached to the rotary cylinder, wherein the fixed cylinder has a stator coil for generating a magnetic force between the stator coil and the disk-shaped magnet, thereby rotating the rotary cylinder, and the head chip is placed on the rotary cylinder so that a phase angle .theta. between a virtual plane including a center of a head gap of the head chip and a rotation axis of the rotary cylinder and one of two polar boundary planes sandwiching the area where the virtual plane traverses satisfies 0.4.alpha..ltoreq..theta..ltoreq.0.6.alpha., where a central angle of the area is .alpha..
    Type: Grant
    Filed: July 20, 1994
    Date of Patent: February 11, 1997
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Takaaki Maegawa, Akio Kuroe, Taizou Hamada, Hiroshi Kanchiku