Patents by Inventor Masakazu Nishikawa

Masakazu Nishikawa 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: 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: 20050200995
    Abstract: A magnetic transfer wherein the exchange of master mediums is made easy to perform is provided, whereby the operational efficiency and transfer efficiency are improved, leading to an overall improvement in productivity in the manufacture of preformatted slave mediums. A master fixing base for determining and supporting the position of a master medium, which bears transfer data, and a conjoining apparatus for conjoining the master medium and the slave medium that is to receive the transfer therefrom are provided. The master medium is exchanged along with the master fixing base. It is preferable that a cleaning means be provided.
    Type: Application
    Filed: May 12, 2005
    Publication date: September 15, 2005
    Inventors: Akito Kamatani, Tsuneo Inui, Masashi Aoki, Masakazu Nishikawa
  • Publication number: 20050200991
    Abstract: A favorable magnetic transfer is, performed on a perpendicular magnetic recording medium. A permanent magnet apparatus provided with two permanent magnets, each having a width extending the length of the radial direction of a discoid magnetic recording medium, is used as a transfer magnetic field generating means. A conjoined body formed of the perpendicular magnetic recording medium, which has been initially magnetized unidirectionally in the direction perpendicular to the track surface thereof, and two master mediums, disposed on respective surfaces of the slave medium, is inserted between the permanent magnets. A rotating means rotates the conjoined body, in the direction along the tracks of the slave medium, while a transfer magnetic field is applied to the conjoined body in the direction substantially opposite that in which the initial magnetization of the magnetic layer of magnetic recording medium has been performed, so as to perform the magnetic transfer.
    Type: Application
    Filed: April 20, 2005
    Publication date: September 15, 2005
    Inventors: Kazunori Komatsu, Masakazu Nishikawa
  • 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: 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
  • Publication number: 20050195509
    Abstract: A favorable magnetic transfer is, performed on a perpendicular magnetic recording medium. A permanent magnet apparatus provided with two permanent magnets, each having a width extending the length of the radial direction of a discoid magnetic recording medium, is used as a transfer magnetic field generating means. A conjoined body formed of the perpendicular magnetic recording medium, which has been initially magnetized unidirectionally in the direction perpendicular to the track surface thereof, and two master mediums, disposed on respective surfaces of the slave medium, is inserted between the permanent magnets. A rotating means rotates the conjoined body, in the direction along the tracks of the slave medium, while a transfer magnetic field is applied to the conjoined body in the direction substantially opposite that in which the initial magnetization of the magnetic layer of magnetic recording medium has been performed, so as to perform the magnetic transfer.
    Type: Application
    Filed: April 20, 2005
    Publication date: September 8, 2005
    Inventors: Kazunori Komatsu, Masakazu Nishikawa
  • 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: 6909634
    Abstract: In a magnetic transfer master carrier, as a substrate, one having a Young's modulus E (GPa) in the range of 85 to 250 is used. Magnetic transfer is performed under conditions in which 2??Ed3/{P(S2/S1)}?400 (where the constant ?=7.37×109) is satisfied, where d (m) is the thickness of the substrate from the bottom face of a recessed portion to the back face, S1 (m2) is the total area of the cross sections of the projected portions which are parallel to the plane of the substrate at a height of 50% of Dmax from the bottom face of the recessed portion when the height from the bottom face of the recessed portion to the top face of a projected portion is denoted by Dmax, S2 (m2) is the total area of the bottom faces of the recessed portions and the cross sections of the projected portions at the positions of the relevant bottom faces, and P (MPa) is the tight contact pressure between the master carrier and the slave medium at the time of magnetic transfer.
    Type: Grant
    Filed: May 19, 2004
    Date of Patent: June 21, 2005
    Assignee: Fuji Photo Film Co., Ltd.
    Inventor: Masakazu Nishikawa
  • 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: 6906877
    Abstract: A method of performing an accurate magnetic transfer to a high-density slave medium having two magnetic layers and utilizing antiferromagnetic coupling. The magnetic layer, which has been initially magnetized in advance, of a magnetic recording medium is conjoined with the data bearing surface of a master medium. A transfer magnetic field is applied to the conjoined body in the circumferential direction of the track of the first magnetic layer in the direction opposite the initial magnetization direction of the second magnetic layer. At this time, the thickness of the magnetic layer of the master medium, the permeability (material) of the magnetic layer, the form of the patterned magnetic layer, the separation distance between the master medium and the magnetic recording medium, etc., may be controlled so that the magnetic field of the transfer magnetic field does not effect the magnetization state of the first magnetic layer.
    Type: Grant
    Filed: June 7, 2002
    Date of Patent: June 14, 2005
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Masakazu Nishikawa, Tadashi Yasunaga
  • Patent number: 6906874
    Abstract: A magnetic transfer wherein the exchange of master mediums is made easy to perform is provided, whereby the operational efficiency and transfer efficiency are improved, leading to an overall improvement in productivity in the manufacture of preformatted slave mediums. A master fixing base for determining and supporting the position of a master medium, which bears transfer data, and a conjoining apparatus for conjoining the master medium and the slave medium that is to receive the transfer therefrom are provided. The master medium is exchanged along with the master fixing base. It is preferable that a cleaning means be provided.
    Type: Grant
    Filed: April 15, 2002
    Date of Patent: June 14, 2005
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Akito Kamatani, Tsuneo Inui, Masashi Aoki, Masakazu Nishikawa
  • 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
  • Patent number: 6906876
    Abstract: A favorable magnetic transfer is performed on a perpendicular magnetic recording medium. A permanent magnet apparatus provided with two permanent magnets, each having a width extending the length of the radial direction of a discoid magnetic recording medium, is used as a transfer magnetic field generating means. A conjoined body formed of the perpendicular magnetic recording medium, which has been initially magnetized unidirectionally in the direction perpendicular to the track surface thereof, and two master mediums, disposed on respective surfaces of the slave medium, is inserted between the permanent magnets. A rotating means rotates the conjoined body, in the direction along the tracks of the slave medium, while a transfer magnetic field is applied to the conjoined body in the direction substantially opposite that in which the initial magnetization of the magnetic layer of magnetic recording medium has been performed, so as to perform the magnetic transfer.
    Type: Grant
    Filed: May 20, 2002
    Date of Patent: June 14, 2005
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Kazunori Komatsu, Masakazu Nishikawa
  • 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
  • Patent number: 6887593
    Abstract: A master information carrier for magnetic transfer includes a substrate having an irregularity pattern representing information to be transferred to a slave medium and a magnetic layer formed on the irregularity pattern on the substrate. The depth d of the recessed portions of the irregularity pattern and the thickness t of the magnetic layer formed on the recessed portions satisfy formula ?0.004?(t?d)/d?0.1. At the same time, the magnetic layer formed on the protruding portion of the irregularity pattern and the magnetic layer formed on the recessed portions of the irregularity pattern are connected with each other.
    Type: Grant
    Filed: September 15, 2003
    Date of Patent: May 3, 2005
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Ryuji Sugita, Masakazu Nishikawa, Tadashi Yasunaga
  • Patent number: 6882484
    Abstract: A magnetic transfer system includes magnetic recording medium stocker which holds a plurality of magnetic recording media, a magnetic transfer apparatus which magnetically transfers information represented by a magnetic layer on a master information carrier to the magnetic recording medium by applying a transfer magnetic field to the magnetic recording medium and the master information carrier with the magnetic recording medium and the master information carrier held in close contact with each other, and a conveyor which conveys the magnetic recording medium between the magnetic recording medium holding means and the magnetic transfer means. The magnetic recording medium holding stocker, the magnetic transfer apparatus and the conveyor are formed of material which contains substantially no chlorine, sulfur compound or nitric oxide at least at a part which is brought into contact with the magnetic recording medium.
    Type: Grant
    Filed: June 25, 2003
    Date of Patent: April 19, 2005
    Assignee: Fuji Photo Film Co., Ltd.
    Inventor: Masakazu Nishikawa
  • 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