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).

  • Patent number: 7630153
    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: Grant
    Filed: August 27, 2004
    Date of Patent: December 8, 2009
    Assignee: FUJIFILM Corporation
    Inventors: Akito Kamatani, Kazuhiro Niitsuma, Seiji Kasahara
  • Publication number: 20090244762
    Abstract: To provide a resist pattern forming method including: cleaning off fine powder at least on an edge of a base material to be processed; forming an imprint resist layer on a surface of the base material whose edge has been cleared of the fine powder; and forming a resist pattern on the surface of the base material by pressing, against the imprint resist layer, a concavo-convex pattern which is provided in a surface of a concavo-convex mold and which is composed of a plurality of convex portions and concave portions formed between the convex portions, so that the resist pattern is an inversion of the concavo-convex pattern.
    Type: Application
    Filed: March 30, 2009
    Publication date: October 1, 2009
    Applicant: FUJIFILM CORPORATION
    Inventors: Yoichi Nishida, Hideyuki Kubota, Kazuhiro Niitsuma, Kazuyuki Usuki
  • Patent number: 7502184
    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: Grant
    Filed: February 8, 2006
    Date of Patent: March 10, 2009
    Assignee: FUJIFILM Corporation
    Inventors: Kazuhiro Niitsuma, Masakazu Nishikawa
  • Patent number: 7465383
    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: Grant
    Filed: April 12, 2005
    Date of Patent: December 16, 2008
    Assignee: FUJIFILM Corporation
    Inventors: Kazuhiro Niitsuma, Masakazu Nishikawa, Tadashi Yasunaga
  • Patent number: 7382558
    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: May 5, 2005
    Date of Patent: June 3, 2008
    Assignee: FUJIFILM Corporation
    Inventors: Masakazu Nishikawa, Kazuhiro Niitsuma, Akito Kamatani
  • Patent number: 7368186
    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: Grant
    Filed: July 23, 2004
    Date of Patent: May 6, 2008
    Assignee: FUJIFILM Corporation
    Inventors: Naoto Fujiwara, Seiji Kasahara, Kazuhiro Niitsuma
  • Publication number: 20080062548
    Abstract: The present invention provides a master recording medium, a magnetic transfer method, a magnetic transfer apparatus, and a magnetic recording medium and a magnetic recording and reproducing apparatus thereby made, which are capable of obtaining a good regenerative signal with few even harmonic components such as the second-order harmonic components on reproducing the information transferred to the magnetic recording medium in the case of recording the information on the magnetic recording medium having a magnetic layer composed of the perpendicular magnetization film by the magnetic transfer.
    Type: Application
    Filed: September 7, 2007
    Publication date: March 13, 2008
    Applicants: FUJIFILM CORPORATION, FUJITSU LIMITED
    Inventors: Naoto Fujiwara, Kenji Sugiyama, Kazuhiro Niitsuma, Tadashi Yasunaga, Tsugito Maruyama, Sumio Kuroda, Yutaka Nakamura, Hiroyuki Suzuki
  • Publication number: 20070217047
    Abstract: An aspect of the present invention provides a master medium for perpendicular magnetic transfer, comprising: a disk-like substrate on a surface of which a plurality of protruding magnetic-layer patterns corresponding to information to be transferred to a magnetic recording medium targeted for transfer are formed. In the master medium for perpendicular magnetic transfer, a ratio of a circumferential width L of the protruding magnetic-layer patterns to a circumferential gap S between the protruding magnetic-layer patterns is L/S<1. According to the aspect of the present invention, good magnetic transfer can be performed and, therefore, a perpendicular magnetic recording medium (a slave disk) that is free from defects and has a good C/N ratio can be obtained. In addition, it is possible to perform good magnetic transfer.
    Type: Application
    Filed: March 9, 2007
    Publication date: September 20, 2007
    Applicants: FUJIFILM Corporation, FUJITSU LIMITED
    Inventors: Kenji Ichikawa, Toshihiro Usa, Kazuhiro Niitsuma, Tadashi Yasunaga, Sumio Kuroda, Tsugito Maruyama
  • Patent number: 7187510
    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: Grant
    Filed: December 19, 2002
    Date of Patent: March 6, 2007
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Tadashi Yasunaga, Kazuhiro Niitsuma
  • Patent number: 7149042
    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: December 20, 2004
    Date of Patent: December 12, 2006
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Masakazu Nishikawa, Tadashi Yasunaga, Kazuhiro Niitsuma
  • Patent number: 7094481
    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: October 6, 2004
    Date of Patent: August 22, 2006
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Masakazu Nishikawa, Kazuhiro Niitsuma, Tadashi Yasunaga, Toshihiro Usa, Kazunori Komatsu
  • Publication number: 20060126202
    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 8, 2006
    Publication date: June 15, 2006
    Inventors: Kazuhiro Niitsuma, Masakazu Nishikawa
  • Patent number: 7054080
    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: May 5, 2005
    Date of Patent: May 30, 2006
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Masakazu Nishikawa, Kazuhiro Niitsuma, Akito Kamatani
  • Patent number: 7054081
    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: May 5, 2005
    Date of Patent: May 30, 2006
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Masakazu Nishikawa, Kazuhiro Niitsuma, Akito Kamatani
  • Patent number: 7038868
    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: Grant
    Filed: February 12, 2003
    Date of Patent: May 2, 2006
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Kazuhiro Niitsuma, Masakazu Nishikawa
  • Publication number: 20060082913
    Abstract: Magnetic field absorbing regions, composed of protrusions or magnetic layers, are provided in an amplitude servo transfer pattern of a patterned master carrier for magnetic transfer. The magnetic field absorbing regions are provided in intermediate tracks between burst bit elements that constitute burst bit strings, which are provided adjacent to each other in a track width direction. The amplitude servo transfer pattern in magnetically transferred onto a magnetic recording medium. Portions of the magnetic recording medium corresponding to the magnetic field absorbing regions become magnetically non-inverted regions. Therefore, noise is not recorded, and servo tracking can be favorably performed.
    Type: Application
    Filed: October 18, 2005
    Publication date: April 20, 2006
    Inventors: Kazuhiro Niitsuma, Makoto Nagao, Tadashi Yasunaga
  • Patent number: 7009790
    Abstract: The present invention enables to execute accurate magnetic transfer without signal omission and the like, by bringing a master carrier which bore transfer information and a slave medium to undergo transfer into close contact with each other uniformly and without a gap when they are received in a holder and brought into confronted close contact with each other. In a magnetic transfer apparatus for executing magnetic transfer by applying magnetic field for transfer generated by a magnetic field applying apparatus after master carriers 3, 4 which bore transfer information and a slave medium 2 to undergo transfer are brought into confronted close contact with each other and received in a holder 10, materials 6, 7 having elastic characteristic are interposed between the holder 10 and master carriers 3, 4, thereby allowing microdeformation of master carriers 3, 4 to enhance the close contact capability with the slave medium.
    Type: Grant
    Filed: June 21, 2002
    Date of Patent: March 7, 2006
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Masakazu Nishikawa, Kazuhiro Niitsuma
  • Patent number: 6985329
    Abstract: A magnetic disk cartridge for use in a disk drive having both a slot and a guide portion. The magnetic disk cartridge comprises a generally disk-shaped housing in which a magnetic disk is rotatably housed, and protrusions. The protrusions are formed on the main surface of the housing and are used for positioning the magnetic disk cartridge in a direction capable of recording and reproduction in cooperation with the guide portion of the disk drive when the magnetic disk cartridge is loaded in the disk drive.
    Type: Grant
    Filed: October 9, 2002
    Date of Patent: January 10, 2006
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Kazuhiro Niitsuma, Ryosuke Ogura, Kazuo Hiraguchi
  • Publication number: 20050200992
    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: 20050200993
    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