Patents by Inventor Norihito KASADA

Norihito KASADA 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: 10497389
    Abstract: The magnetic tape includes a magnetic layer having ferromagnetic powder and a binder on a non-magnetic support, in which the magnetic layer includes a timing-based servo pattern, the ferromagnetic powder is ferromagnetic hexagonal ferrite powder having an activation volume equal to or smaller than 1,600 nm3, and an edge shape of the timing-based servo pattern specified by a magnetic force microscope observation is a shape in which a difference (l99.9?l0.1) between a value l99.9 of a cumulative frequency function of 99.9% of a position deviation width from an ideal shape in a longitudinal direction of the magnetic tape and a value l0.1 of the cumulative frequency function of 0.1% thereof is equal to or smaller than 180 nm.
    Type: Grant
    Filed: August 10, 2018
    Date of Patent: December 3, 2019
    Assignee: FUJIFILM Corporation
    Inventors: Tetsuya Kaneko, Norihito Kasada, Eiki Ozawa
  • Patent number: 10490220
    Abstract: Provided is a magnetic tape device in which a magnetic tape transportation speed is equal to or lower than 18 m/sec, Ra measured regarding a surface of a magnetic layer of a magnetic tape is equal to or smaller than 2.0 nm, a C—H derived C concentration calculated from a C—H peak area ratio of C1s spectra obtained by X-ray photoelectron spectroscopic analysis performed on the surface of the magnetic layer at a photoelectron take-off angle of 10 degrees is 45 to 65 atom %, and ?SFD (=SFD25°C.?SFD?190° C.) in a longitudinal direction of the magnetic tape is equal to or smaller than 0.50, with the SFD25° C. being SFD measured in a longitudinal direction of the magnetic tape at a temperature of 25° C., and the SFD?190° C. being SFD measured at a temperature of ?190° C.
    Type: Grant
    Filed: October 15, 2018
    Date of Patent: November 26, 2019
    Assignee: FUJIFILM Corporation
    Inventors: Norihito Kasada, Eiki Ozawa
  • Patent number: 10482915
    Abstract: The magnetic tape device includes: a magnetic tape; and a reproducing head, in which the reproducing head is a TMR head, the magnetic tape includes a non-magnetic support, and a magnetic layer including ferromagnetic powder, a binding agent, and fatty acid ester on the non-magnetic support, a full width at half maximum of spacing distribution measured by optical interferometry regarding a surface of the magnetic layer before performing a vacuum heating with respect to the magnetic tape is greater than 0 nm and equal to or smaller than 7.0 nm, a full width at half maximum of spacing distribution measured after performing the vacuum heating is greater than 0 nm and equal to or smaller than 7.0 nm, and a difference between a spacing measured by optical interferometry regarding the surface of the magnetic layer after performing the vacuum heating with respect to the magnetic tape and a spacing measured before performing the vacuum heating is greater than 0 nm and equal to or smaller than 9.0 nm.
    Type: Grant
    Filed: December 26, 2017
    Date of Patent: November 19, 2019
    Assignee: FUJIFILM Corporation
    Inventors: Eiki Ozawa, Tetsuya Kaneko, Norihito Kasada
  • Patent number: 10482913
    Abstract: A magnetic tape includes a non-magnetic support; a non-magnetic layer including non-magnetic powder and a binding agent on the non-magnetic support; and a magnetic layer including ferromagnetic powder and a binding agent on the non-magnetic layer. The total thickness of the non-magnetic layer and the magnetic layer is less than or equal to 0.60 ?m. The magnetic layer includes an abrasive, and the percentage of a plan view maximum area of the abrasive confirmed in a region having a size of 4.3 ?m×6.3 ?m of the surface of the magnetic layer with respect to the total area of the region, obtained by plane observation performed by using a scanning electron microscope, is greater than or equal to 0.02% and less than 0.06%. Also, the logarithmic decrement acquired by a pendulum viscoelasticity test performed regarding the surface of the magnetic layer is less than or equal to 0.050.
    Type: Grant
    Filed: February 20, 2018
    Date of Patent: November 19, 2019
    Assignee: FUJIFILM Corporation
    Inventor: Norihito Kasada
  • Patent number: 10475481
    Abstract: The magnetic tape has a magnetic layer and a backcoat layer. The Ra on the magnetic layer side surface is less than or equal to 1.8 nm, the coefficient of friction measured on the base portion of the magnetic layer side surface is less than or equal to 0.35, and the Ra measured on the backcoat layer side surface is less than or equal to 5.0 nm. The backcoat layer contains a fatty acid ester. In addition, the FWHMbefore measured on the backcoat layer side surface before vacuum heating is greater than 0 nm but less than or equal to 10.0 nm, the FWHMafter after vacuum heating is greater than 0 nm but less than or equal to 10.0 nm, and the difference between the spacing measured on the backcoat layer side surface after and before vacuum heating is greater than 0 nm but less than or equal to 8.0 nm.
    Type: Grant
    Filed: February 2, 2017
    Date of Patent: November 12, 2019
    Assignee: FUJIFILM Corporation
    Inventors: Masahito Oyanagi, Norihito Kasada, Eiki Ozawa
  • Patent number: 10477072
    Abstract: A magnetic tape is provided in which ferromagnetic powder included in a magnetic layer is ferromagnetic hexagonal ferrite powder having an activation volume less than or equal to 1,600 nm3. The magnetic layer includes one or more components selected from a fatty acid and a fatty acid amide, and an abrasive. The C—H derived C concentration calculated from the C—H peak area ratio of C1s spectra obtained by X-ray photoelectron spectroscopic analysis performed on the surface of the magnetic layer at a photoelectron take-off angle of 10 degrees is greater than or equal to 45 atom %. Also, the tilt cos ? of the ferromagnetic hexagonal ferrite powder with respect to the surface of the magnetic layer acquired by cross section observation performed by using a scanning transmission electron microscope is 0.85 to 1.00.
    Type: Grant
    Filed: June 13, 2017
    Date of Patent: November 12, 2019
    Assignee: FUJIFILM Corporation
    Inventor: Norihito Kasada
  • Patent number: 10475480
    Abstract: A magnetic tape includes a non-magnetic support; a magnetic layer including ferromagnetic powder and a binding agent on one surface side of the non-magnetic support; and a back coating layer including non-magnetic powder and a binding agent on the other surface side of the non-magnetic support. The center line average surface roughness Ra measured regarding a surface of the magnetic layer is less than or equal to 1.8 nm. The contact angle with respect to 1-bromonaphthalene measured regarding the surface of the magnetic layer is 45.0° to 55.0°. Also, the logarithmic decrement acquired by a pendulum viscoelasticity test performed regarding the surface of the back coating layer is less than or equal to 0.060.
    Type: Grant
    Filed: February 20, 2018
    Date of Patent: November 12, 2019
    Assignee: FUJIFILM Corporation
    Inventors: Takuto Kurokawa, Norihito Kasada
  • Patent number: 10460756
    Abstract: A magnetic tape device includes: a magnetic tape including a servo pattern on a magnetic layer; and a Tunneling Magnetoresistive (TMR) head as a servo head, in which the center line average surface roughness Ra measured regarding a surface of the magnetic layer of the magnetic tape is equal to or smaller than 2.0 nm, the logarithmic decrement acquired by a pendulum viscoelasticity test performed regarding the surface of the magnetic layer is equal to or smaller than 0.050, and ?SFD in a longitudinal direction of the magnetic tape calculated by Expression 1: ?SFD=SFD25° C.?SFD?190° C. is equal to or smaller than 0.50, wherein the SFD25° C. is SFD measured in a longitudinal direction of the magnetic tape at a temperature of 25° C., and the SFD?190° C. is SFD measured in a longitudinal direction of the magnetic tape at a temperature of ?190° C.
    Type: Grant
    Filed: February 20, 2018
    Date of Patent: October 29, 2019
    Assignee: FUJIFILM Corporation
    Inventors: Norihito Kasada, Eiki Ozawa
  • Patent number: 10453488
    Abstract: A magnetic tape includes a non-magnetic support; and a magnetic layer including ferromagnetic powder and a binding agent on the non-magnetic support. The center line average surface roughness Ra measured regarding the surface of the magnetic layer is less than or equal to 1.8 nm. The logarithmic decrement acquired by a pendulum viscoelasticity test performed regarding the surface of the magnetic layer is less than or equal to 0.050, and the contact angle with respect to 1-bromonaphthalene measured regarding the surface of the magnetic layer is 45.0° to 55.0°.
    Type: Grant
    Filed: February 20, 2018
    Date of Patent: October 22, 2019
    Assignee: FUJIFILM Corporation
    Inventors: Takuto Kurokawa, Norihito Kasada
  • Patent number: 10438623
    Abstract: A magnetic tape has a total thickness of a non-magnetic layer and a magnetic layer of 0.60 ?m or smaller. The magnetic layer includes an abrasive and fatty acid ester. The percentage of a plan view maximum area of the abrasive confirmed in a region having a size of 4.3 ?m×6.3 ?m of the surface of the magnetic layer with respect to the total area of the region, obtained by plane observation performed by using an SEM is 0.02% or greater and less than 0.06%. The full widths at half maximum of spacing distribution measured by optical interferometry regarding the surface of the magnetic layer before and after performing a vacuum heating with respect to the magnetic tape are greater than 0 nm and 7.0 nm or smaller, and the difference between spacings before and after the vacuum heating is greater than 0 nm and is 8.0 nm or smaller.
    Type: Grant
    Filed: March 14, 2018
    Date of Patent: October 8, 2019
    Assignee: FUJIFILM Corporation
    Inventors: Eiki Ozawa, Norihito Kasada
  • Patent number: 10438625
    Abstract: A magnetic tape has an Ra measured regarding the surface of the magnetic layer of less than or equal to 1.8 nm, and a logarithmic decrement acquired by a pendulum viscoelasticity test performed regarding the surface of the magnetic layer of less than or equal to 0.050. The magnetic layer includes fatty acid ester. The full width at half maximum of spacing distribution measured by optical interferometry regarding the surface of the magnetic layer before and after performing vacuum heating with respect to the magnetic tape is respectively greater than 0 nm and less than or equal to 7.0 nm, and the difference between the spacing measured by optical interferometry regarding the surface of the magnetic layer after performing the vacuum heating with respect to the magnetic tape and the spacing measured before performing the vacuum heating is greater than 0 nm and less than or equal to 8.0 nm.
    Type: Grant
    Filed: February 20, 2018
    Date of Patent: October 8, 2019
    Assignee: FUJIFILM Corporation
    Inventors: Eiki Ozawa, Norihito Kasada
  • Patent number: 10438621
    Abstract: A magnetic tape includes a non-magnetic support; a magnetic layer including ferromagnetic powder and a binding agent on one surface side of the non-magnetic support; and a back coating layer including non-magnetic powder and a binding agent on the other surface side of the non-magnetic support. The thickness of the back coating layer is less than or equal to 0.30 ?m. The logarithmic decrement acquired by a pendulum viscoelasticity test performed regarding the surface of the back coating layer is less than or equal to 0.060. Further, the contact angle with respect to 1-bromonaphthalene measured regarding the surface of the back coating layer is 15.0° to 30.0°.
    Type: Grant
    Filed: February 20, 2018
    Date of Patent: October 8, 2019
    Assignee: FUJIFILM Corporation
    Inventor: Norihito Kasada
  • Patent number: 10438624
    Abstract: A magnetic tape includes a non-magnetic support; and a magnetic layer including ferromagnetic powder and a binding agent on the non-magnetic support. The center line average surface roughness Ra measured regarding the surface of the magnetic layer is less than or equal to 1.8 nm. The logarithmic decrement acquired by a pendulum viscoelasticity test performed regarding the surface of the magnetic layer is less than or equal to 0.050. The ferromagnetic powder is ferromagnetic hexagonal ferrite powder, the magnetic layer includes an abrasive, and the tilt cos ? of the ferromagnetic hexagonal ferrite powder with respect to the surface of the magnetic layer acquired by cross section observation performed using a scanning transmission electron microscope is 0.85 to 1.00.
    Type: Grant
    Filed: February 20, 2018
    Date of Patent: October 8, 2019
    Assignee: FUJIFILM Corporation
    Inventor: Norihito Kasada
  • Patent number: 10438622
    Abstract: The magnetic tape device includes a magnetic tape; and a servo head, in which the servo head is a TMR head, the magnetic tape includes a servo pattern in the magnetic layer, a center line average surface roughness Ra measured regarding a surface of the magnetic layer is equal to or smaller than 2.0 nm, a logarithmic decrement acquired by a pendulum viscoelasticity test performed regarding the surface of the magnetic layer is equal to or smaller than 0.050, and a ratio (Sdc/Sac) of an average area Sdc of a magnetic cluster of the magnetic tape in a DC demagnetization state and an average area Sac of a magnetic cluster thereof in an AC demagnetization state measured with a magnetic force microscope is 0.80 to 1.30.
    Type: Grant
    Filed: July 25, 2018
    Date of Patent: October 8, 2019
    Assignee: FUJIFILM Corporation
    Inventors: Norihito Kasada, Eiki Ozawa
  • Patent number: 10438628
    Abstract: The magnetic tape device includes: a magnetic tape; and a reproducing head, in which a magnetic tape transportation speed of the magnetic tape device is equal to or lower than 18 m/sec, the reproducing head is a magnetic head including a tunnel magnetoresistance effect type element as a reproducing element, the magnetic tape includes a non-magnetic support, and a magnetic layer including ferromagnetic powder and a binding agent on the non-magnetic support, the magnetic layer includes one or more components selected from the group consisting of fatty acid and fatty acid amide, and a C—H derived C concentration calculated from a C—H peak area ratio of C1s spectra obtained by X-ray photoelectron spectroscopic analysis performed on the surface of the magnetic layer at a photoelectron take-off angle of 10 degrees is 45 to 65 atom %.
    Type: Grant
    Filed: December 26, 2017
    Date of Patent: October 8, 2019
    Assignee: FUJIFILM Corporation
    Inventors: Norihito Kasada, Eiki Ozawa, Tetsuya Kaneko
  • Patent number: 10431251
    Abstract: The magnetic tape device includes a TMR head (reproducing head); and a magnetic tape including a magnetic layer including ferromagnetic powder, a binding agent, and fatty acid ester, in which Ra measured regarding a surface of the magnetic layer is equal to or smaller than 2.0 nm, full widths at half maximum of spacing distribution measured by optical interferometry regarding the surface of the magnetic layer before and after performing a vacuum heating with respect to the magnetic tape are greater than 0 nm and equal to or smaller than 7.0 nm, a difference between spacings before and after the vacuum heating is greater than 0 nm and equal to or smaller than 8.0 nm, and ?SFD (=SFD25° C.?SFD?190° C.) in a longitudinal direction of the magnetic tape is equal to or smaller than 0.50.
    Type: Grant
    Filed: March 14, 2018
    Date of Patent: October 1, 2019
    Assignee: FUJIFILM Corporation
    Inventors: Eiki Ozawa, Norihito Kasada
  • Patent number: 10431248
    Abstract: A magnetic tape includes a non-magnetic layer including non-magnetic powder and a binder on a non-magnetic support; and a magnetic layer including ferromagnetic powder and a binder on the non-magnetic layer. The magnetic layer includes a timing-based servo pattern. The center line average surface roughness Ra measured regarding the surface of the magnetic layer is less than or equal to 1.8 nm. One or more components selected from a fatty acid and a fatty acid amide are included in at least the magnetic layer, and the C—H derived C concentration calculated from the C—H peak area ratio of C1s spectra obtained by X-ray photoelectron spectroscopic analysis performed on the surface of the magnetic layer at a photoelectron take-off angle of 10 degrees is greater than or equal to 45 atom %.
    Type: Grant
    Filed: June 6, 2017
    Date of Patent: October 1, 2019
    Assignee: FUJIFILM Corporation
    Inventors: Norihito Kasada, Tetsuya Kaneko, Eiki Ozawa
  • Patent number: 10431250
    Abstract: A magnetic tape includes a non-magnetic support; and a magnetic layer including ferromagnetic powder and a binding agent on the non-magnetic support. The center line average surface roughness Ra measured regarding the surface of the magnetic layer is less than or equal to 1.8 nm. The logarithmic decrement acquired by a pendulum viscoelasticity test performed regarding the surface of the magnetic layer is less than or equal to 0.050, and ?SFD in a longitudinal direction of the magnetic tape calculated by Expression 1: ?SFD=SFD25° C.?SFD?190° C. is greater than or equal to 0.35. In Expression 1, the SFD25° C. is the switching field distribution SFD measured in a longitudinal direction of the magnetic tape at a temperature of 25° C., and the SFD?190° C. is the switching field distribution SFD measured in a longitudinal direction of the magnetic tape at a temperature of ?190° C.
    Type: Grant
    Filed: February 20, 2018
    Date of Patent: October 1, 2019
    Assignee: FUJIFILM Corporation
    Inventors: Toshio Tada, Norihito Kasada
  • Patent number: 10431249
    Abstract: A magnetic tape includes a magnetic layer having ferromagnetic powder and a binder on a non-magnetic support. The total thickness of the magnetic tape is less than equal to 5.30 ?m. The magnetic layer includes a timing-based servo pattern. The center line average surface roughness Ra measured regarding the surface of the magnetic layer is less than or equal to 1.8 nm. One or more components selected from a fatty acid and a fatty acid amide are included in the magnetic layer, and the C—H derived C concentration calculated from the C—H peak area ratio of C1s spectra obtained by X-ray photoelectron spectroscopic analysis performed on the surface of the magnetic layer at a photoelectron take-off angle of 10 degrees is greater than or equal to 45 atom %.
    Type: Grant
    Filed: June 13, 2017
    Date of Patent: October 1, 2019
    Assignee: FUJIFILM Corporation
    Inventors: Norihito Kasada, Tetsuya Kaneko, Eiki Ozawa
  • Publication number: 20190295587
    Abstract: The magnetic tape includes a non-magnetic support; and a magnetic layer including ferromagnetic powder and a binding agent on the non-magnetic support, in which an absolute value ?N of a difference between a refractive index Nxy measured regarding an in-plane direction of the magnetic layer and a refractive index Nz measured regarding a thickness direction of the magnetic layer is 0.25 to 0.40, and a logarithmic decrement acquired by a pendulum viscoelasticity test performed regarding a surface of the magnetic layer is equal to or smaller than 0.050.
    Type: Application
    Filed: March 22, 2019
    Publication date: September 26, 2019
    Applicant: FUJIFILM Corporation
    Inventor: Norihito KASADA