Patents by Inventor Kazuhiro Niitsuma

Kazuhiro Niitsuma 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: 20050200994
    Abstract: By bring a master carrier and a slave medium into close contact with uniform force when executing magnetic transfer by applying transfer magnetic field in the state that the master carrier and slave medium is in confronted close contact and received within a holder, inferiority of transfer such as omission of signals is prevented and quality of transfer signals is enhanced. The magnetic transfer apparatus executes magnetic transfer by applying transfer magnetic field by means of a magnetic field applying apparatus 5 after a master carrier 3, 4 bearing transfer information and a slave medium 2 to be transferred are brought into confronted close contact and received within a holder 10, wherein said holder 10 has a substantially circular shape and in particular, the circularity of holder is not less than 98%, wherein the flexural rigidity=Ed3/12 determined by Young's modulus E and thickness d of the holder is in the range of 0.
    Type: Application
    Filed: May 5, 2005
    Publication date: September 15, 2005
    Inventors: Masakazu Nishikawa, Kazuhiro Niitsuma, Akito Kamatani
  • Publication number: 20050190470
    Abstract: By bring a master carrier and a slave medium into close contact with uniform force when executing magnetic transfer by applying transfer magnetic field in the state that the master carrier and slave medium is in confronted close contact and received within a holder, inferiority of transfer such as omission of signals is prevented and quality of transfer signals is enhanced. The magnetic transfer apparatus executes magnetic transfer by applying transfer magnetic field by means of a magnetic field applying apparatus 5 after a master carrier 3, 4 bearing transfer information and a slave medium 2 to be transferred are brought into confronted close contact and received within a holder 10, wherein said holder 10 has a substantially circular shape and in particular, the circularity of holder is not less than 98%, wherein the flexural rigidity=Ed3/12 determined by Young's modulus E and thickness d of the holder is in the range of 0.
    Type: Application
    Filed: May 5, 2005
    Publication date: September 1, 2005
    Inventors: Masakazu Nishikawa, Kazuhiro Niitsuma, Akito Kamatani
  • Publication number: 20050181133
    Abstract: A master information carrier for magnetic transfer includes a master substrate made of metal, including an embossed pattern corresponding to information to be transferred. The master substrate is produced by laminating a metal disk with a predetermined thickness on an original disk, on which an embossed pattern is formed, by electroforming, peeling off the metal disk and die-cutting a disk in a desired size. An outer diameter of the metal disk is at least 1.7 times longer than an outer diameter of the die-cut master substrate. When the metal disk is peeled off from the original disk, deformation due to the forces acting from the side of the outer circumference is reduced. The flatness of the metal disk is ensured and the transfer qualities are improved. Further, a step of removing distortion of the metal disk, caused at the time of peeling off the metal disk, may also be provided.
    Type: Application
    Filed: April 12, 2005
    Publication date: August 18, 2005
    Inventors: Kazuhiro Niitsuma, Masakazu Nishikawa, Tadashi Yasunaga
  • Patent number: 6911270
    Abstract: A master information carrier for magnetic transfer includes a base sheet which is formed of a magnetic material. The master information carrier is provided with an irregularity pattern representing information to be transferred to a magnetic recording medium and a magnetic layer formed along the irregularity pattern. The saturation magnetization Mm of the magnetic layer and the saturation magnetization Ms of the base sheet satisfy the condition 1.0<Mm/Ms<100.
    Type: Grant
    Filed: December 12, 2002
    Date of Patent: June 28, 2005
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Masakazu Nishikawa, Kazuhiro Niitsuma, Tadashi Yasunaga, Toshihiro Usa, Kazunori Komatsu
  • Patent number: 6909563
    Abstract: A master carrier for magnetic transfer is equipped with a substrate having a land/groove pattern. The land/groove pattern is formed from a magnetic material and corresponds to information that is transferred to a magnetic recording disk. Each land in the land/groove pattern has four round corners whose radius is from 1% through 47% of the width of a data track on the disk.
    Type: Grant
    Filed: May 13, 2002
    Date of Patent: June 21, 2005
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Masakazu Nishikawa, Tadashi Yasunaga, Kazuhiro Niitsuma
  • Patent number: 6909564
    Abstract: By bring a master carrier and a slave medium into close contact with uniform force when executing magnetic transfer by applying transfer magnetic field in the state that the master carrier and slave medium is in confronted close contact and received within a holder, inferiority of transfer such as omission of signals is prevented and quality of transfer signals is enhanced. The magnetic transfer apparatus executes magnetic transfer by applying transfer magnetic field by means of a magnetic field applying apparatus 5 after a master carrier 3, 4 bearing transfer information and a slave medium 2 to be transferred are brought into confronted close contact and received within a holder 10, wherein said holder 10 has a substantially circular shape and in particular, the circularity of holder is not less than 98%, wherein the flexural rigidity=Ed3/12 determined by Young's modulus E and thickness d of the holder is in the range of 0.
    Type: Grant
    Filed: June 13, 2002
    Date of Patent: June 21, 2005
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Masakazu Nishikawa, Kazuhiro Niitsuma, Akito Kamatani
  • Patent number: 6906875
    Abstract: A magnetic transfer device for bringing a master carrier with information and a slave medium into intimate contact with each other and then applying a transfer field to transfer the information to the slave medium. The master carrier has an inclined face on its radially outer end. After the magnetic transfer of the information, claws are inserted in the gas formed by the inclined face of the master carrier and the slave medium. The slave medium held in intimate contact with the master carrier is separated from the master carrier by lifting the slave medium with the claws.
    Type: Grant
    Filed: May 14, 2002
    Date of Patent: June 14, 2005
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Akito Kamatani, Masakazu Nishikawa, Makoto Nagao, Kazunori Komatsu, Tsuneo Inui, Kazuhiro Niitsuma
  • Publication number: 20050111124
    Abstract: A master carrier for magnetic transfer is equipped with a substrate having a land/groove pattern. The land/groove pattern is formed from a magnetic material and corresponds to information that is transferred to a magnetic recording disk. Each land in the land/groove pattern has four round corners whose radius is from 1% through 47% of the width of a data track on the disk.
    Type: Application
    Filed: December 20, 2004
    Publication date: May 26, 2005
    Inventors: Masakazu Nishikawa, Tadashi Yasunaga, Kazuhiro Niitsuma
  • Publication number: 20050078392
    Abstract: A master carrier for magnetic transfer, has: a support having an information writing region where a projection transfer pattern having a first projection is formed, the first projection corresponding to information to be transferred onto a magnetic recording medium; and a magnetic layer on the transfer pattern of the support, wherein the master carrier has a second projection on a surface of the support and the second projection is formed in a region where the information writing region isn't formed to sustain the region where the information writing region isn't formed while the magnetic recording medium and the support are brought into intimate contact with each other.
    Type: Application
    Filed: August 27, 2004
    Publication date: April 14, 2005
    Inventors: Akito Kamatani, Kazuhiro Niitsuma, Seiji Kasahara
  • Patent number: 6879452
    Abstract: A master information carrier includes a base sheet provided with a pattern representing a signal and a magnetic layer formed on the pattern. A transfer magnetic field is applied to a slave medium in a close contact with the master information carrier to magnetically transfer the signal from the master information carrier to the slave medium. The coefficient of thermal expansion of the base sheet of the master information carrier is in the range of 5×10?6/° C. to 25×10?6/° C., and the thermal expansion difference in different directions of the base sheet of the master information carrier is not larger than 8×10?6/° C.
    Type: Grant
    Filed: December 19, 2002
    Date of Patent: April 12, 2005
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Kazuhiro Niitsuma, Masakazu Nishikawa
  • Patent number: 6876520
    Abstract: A magnetic disk cartridge comprising a housing with space, and a magnetic disk rotatably held in the space of the housing. The magnetic disk includes a flexible magnetic recording medium, and at least one rigid ring mounted on the circumferential edge portion of the magnetic recording medium.
    Type: Grant
    Filed: December 10, 2002
    Date of Patent: April 5, 2005
    Assignee: Fuji Photo Film Co., Ltd.
    Inventor: Kazuhiro Niitsuma
  • Publication number: 20050041314
    Abstract: A master information carrier for magnetic transfer to an in-plane magnetic recording medium includes a base sheet having an irregularity pattern representing information to be transferred to an in-plane magnetic recording medium and a magnetic layer formed along the irregularity pattern. The thickness da1 of the magnetic layer on the upper surface of a protruding portion of the irregularity pattern and the thickness da2 of the magnetic layer on each of the side surfaces of the protruding portion satisfy the following condition, 0.05<da2/da1?1.3.
    Type: Application
    Filed: October 6, 2004
    Publication date: February 24, 2005
    Inventors: Masakazu Nishikawa, Kazuhiro Niitsuma, Tadashi Yasunga, Toshihiro Usa, Kazunori Komatsu
  • Publication number: 20050018335
    Abstract: The master carrier for magnetic transfer of the invention comprises a support and a magnetic layer formed on the surface of the support, wherein an uneven transfer pattern that corresponds to the information to be transferred to a magnetic recording medium is formed in the surface of the magnetic layer, and a relief is formed in the site where the transfer pattern is not formed.
    Type: Application
    Filed: July 23, 2004
    Publication date: January 27, 2005
    Inventors: Naoto Fujiwara, Seiji Kasahara, Kazuhiro Niitsuma
  • Patent number: 6824835
    Abstract: A flexible magnetic recording medium to which data is transferred by being brought into intimate contact with a master carrier which has a land/groove pattern corresponding to the data and also has a surface whose Moh's hardness is 6 to 10. The magnetic recording medium includes a substrate, a non-magnetic layer, and a magnetic layer. The non-magnetic layer and the magnetic layer are coated on the substrate in the recited order. The magnetic layer contains an abrasive comprising diamond particles whose average particle size is 0.03 to 0.5 &mgr;m. The diamond particle content of the abrasive is in a range of 0.1 to 5 wt % of ferromagnetic powder contained in the magnetic layer.
    Type: Grant
    Filed: December 12, 2002
    Date of Patent: November 30, 2004
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Hitoshi Noguchi, Kazuhiro Niitsuma
  • Patent number: 6816327
    Abstract: A master information carrier for magnetic transfer to an in-plane magnetic recording medium includes a base sheet having an irregularity pattern representing information to be transferred to an in-plane magnetic recording medium and a magnetic layer formed along the irregularity pattern. The thickness da1 of the magnetic layer on the upper surface of a protruding portion of the irregularity pattern and the thickness da2 of the magnetic layer on each of the side surfaces of the protruding portion satisfy the following condition, 0.05<da2/da1≦1.3.
    Type: Grant
    Filed: November 27, 2002
    Date of Patent: November 9, 2004
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Masakazu Nishikawa, Kazuhiro Niitsuma, Tadashi Yasunaga, Toshihiro Usa, Kazunori Komatsu
  • Publication number: 20040180174
    Abstract: A master information carrier for magnetic transfer includes a master substrate made of metal, including an embossed pattern corresponding to information to be transferred. The master substrate is produced by laminating a metal disk with a predetermined thickness on an original disk, on which an embossed pattern is formed, by electroforming, peeling off the metal disk and die-cutting a disk in a desired size. An outer diameter of the metal disk is at least 1.7 times longer than an outer diameter of the die-cut master substrate. When the metal disk is peeled off from the original disk, deformation due to the forces acting from the side of the outer circumference is reduced. The flatness of the metal disk is ensured and the transfer qualities are improved. Further, a step of removing distortion of the metal disk, caused at the time of peeling off the metal disk, may also be provided.
    Type: Application
    Filed: March 3, 2004
    Publication date: September 16, 2004
    Applicant: FUJI PHOTO FILM CO., LTD.
    Inventors: Kazuhiro Niitsuma, Masakazu Nishikawa, Tadashi Yasunaga
  • Publication number: 20030184895
    Abstract: When magnetically transferring information represented by a pattern of magnetic layer formed on a master information carrier to a disc-like slave medium, an initial DC magnetic field is applied to the slave medium to initially magnetize the slave medium in one direction of concentric recording tracks and a transfer magnetic field is applied to the slave medium in the direction opposite to the direction of the initial-magnetization with the initially-magnetized slave medium held in close contact with the master information carrier. At least one of applying the initial DC magnetic field and applying the transfer magnetic field is effected by applying the magnetic field while the slave medium is being rotated relatively to the magnetic field and stopping the rotation of the slave medium after the intensity of the magnetic field is gradually reduced to not stronger than a predetermined value.
    Type: Application
    Filed: February 12, 2003
    Publication date: October 2, 2003
    Applicant: FUJI PHOTO FILM CO., LTD.
    Inventors: Kazuhiro Niitsuma, Masakazu Nishikawa
  • Publication number: 20030152808
    Abstract: A flexible magnetic recording medium to which data is transferred by being brought into intimate contact with a master carrier which has a land/groove pattern corresponding to the data and also has a surface whose Moh's hardness is 6 to 10. The magnetic recording medium includes a substrate, a non-magnetic layer, and a magnetic layer. The non-magnetic layer and the magnetic layer are coated on the substrate in the recited order. The magnetic layer contains an abrasive comprising diamond particles whose average particle size is 0.03 to 0.5 &mgr;m. The diamond particle content of the abrasive is in a range of 0.1 to 5 wt % of ferromagnetic powder contained in the magnetic layer.
    Type: Application
    Filed: December 12, 2002
    Publication date: August 14, 2003
    Applicant: FUJI PHOTO FILM CO., LTD.
    Inventors: Hitoshi Noguchi, Kazuhiro Niitsuma
  • Publication number: 20030117735
    Abstract: A signal such as a servo tracking signal is recorded on a flexible slave medium by magnetic transfer. When forming the flexible slave medium of a magnetic strip in a continuous length, the signal is recorded on the magnetic strip by patterned master magnetic transfer prior to or simultaneously with shaping the magnetic strip into a desired shape.
    Type: Application
    Filed: December 19, 2002
    Publication date: June 26, 2003
    Applicant: FUJI PHOTO FILM CO., LTD.
    Inventors: Tadashi Yasunaga, Kazuhiro Niitsuma
  • Publication number: 20030117736
    Abstract: A master information carrier includes a base sheet provided with a pattern representing a signal and a magnetic layer formed on the pattern. A transfer magnetic field is applied to a slave medium in a close contact with the master information carrier to magnetically transfer the signal from the master information carrier to the slave medium. The coefficient of thermal expansion of the base sheet of the master information carrier is in the range of 5×10−6/° C. to 25×10−6/° C., and the thermal expansion difference in different directions of the base sheet of the master information carrier is not larger than 8×10−6/° C.
    Type: Application
    Filed: December 19, 2002
    Publication date: June 26, 2003
    Applicant: FUJI PHOTO FILM CO., LTD.
    Inventors: Kazuhiro Niitsuma, Masakazu Nishikawa