Patents by Inventor Masanobu Itaya

Masanobu Itaya 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: 20210375313
    Abstract: A magnetic-disk substrate has a pair of main surfaces, and an arithmetic average roughness Ra of each of the main surfaces is 0.11 nm or less. The arithmetic average roughness Ra is a value obtained through measurement using an atomic force microscope provided with a probe having a probe tip provided with a carbon nanofiber rod-shaped member. The magnetic-disk substrate is made of glass or aluminum alloy.
    Type: Application
    Filed: July 26, 2021
    Publication date: December 2, 2021
    Inventors: Masanobu ITAYA, Kinobu OSAKABE
  • Publication number: 20210327464
    Abstract: A magnetic-disk substrate has an average value of squares of inclinations that is 0.0025 or less, and a frequency at which squares of inclinations are 0.004 or more is 15% or less, in a case where samples of inclinations on a main surface are obtained at intervals of 10 nm. The main surface is configured to receive at least a magnetic recording layer thereon. The magnetic-disk substrate includes an outer circumferential end portion and an inner circumferential end portion, and the outer circumferential end portion and the inner circumferential end portion have chamfered portions.
    Type: Application
    Filed: June 30, 2021
    Publication date: October 21, 2021
    Applicants: HOYA CORPORATION, HOYA GLASS DISK VIETNAM II LTD.
    Inventors: Masanobu ITAYA, Kinobu OSAKABE, Toshio TAKIZAWA
  • Patent number: 11094345
    Abstract: A magnetic-disk substrate has a pair of main surfaces, and an arithmetic average roughness Ra of each of the main surfaces is 0.11 nm or less. The arithmetic average roughness Ra is a value obtained through measurement using an atomic force microscope provided with a probe having a probe tip provided with a carbon nanofiber rod-shaped member. The magnetic-disk substrate is made of glass or aluminum alloy.
    Type: Grant
    Filed: April 26, 2019
    Date of Patent: August 17, 2021
    Assignee: HOYA CORPORATION
    Inventors: Masanobu Itaya, Kinobu Osakabe
  • Patent number: 11081134
    Abstract: A hard disk drive includes a magnetic-disk substrate in which an average value of squares of inclinations is 0.0025 or less and a frequency at which squares of inclinations are 0.004 or more is 15% or less, in a case where samples of inclinations on a main surface are obtained at intervals of 10 nm.
    Type: Grant
    Filed: March 28, 2019
    Date of Patent: August 3, 2021
    Assignees: HOYA CORPORATION, HOYA GLASS DISK VIETNAM II LTD.
    Inventors: Masanobu Itaya, Kinobu Osakabe, Toshio Takizawa
  • Patent number: 10497387
    Abstract: A magnetic-disk glass substrate according to the present invention is a doughnut-shaped magnetic-disk glass substrate having a circular hole provided in the center, a pair of main surfaces, and an outer circumferential end surface and an inner circumferential end surface each including a side wall surface and a chamfered surface that is formed between each main surface and the side wall surface. A measurement point is provided on the outer circumferential end surface every 30 degrees in the circumferential direction with reference to a center of the glass substrate, and when a curvature radius of a shape of a portion between the side wall surface and the chamfered surface is determined at each measurement point, the difference in the curvature radius between neighboring measurement points is 0.01 mm or less.
    Type: Grant
    Filed: March 23, 2017
    Date of Patent: December 3, 2019
    Assignee: HOYA CORPORATION
    Inventors: Masanobu Itaya, Kinobu Osakabe
  • Publication number: 20190251993
    Abstract: A magnetic-disk substrate has a pair of main surfaces, and an arithmetic average roughness Ra of each of the main surfaces is 0.11 nm or less. The arithmetic average roughness Ra is a value obtained through measurement using an atomic force microscope provided with a probe having a probe tip provided with a carbon nanofiber rod-shaped member. The magnetic-disk substrate is made of glass or aluminum alloy.
    Type: Application
    Filed: April 26, 2019
    Publication date: August 15, 2019
    Inventors: Masanobu ITAYA, Kinobu OSAKABE
  • Publication number: 20190228801
    Abstract: A hard disk drive includes a magnetic-disk substrate in which an average value of squares of inclinations is 0.0025 or less and a frequency at which squares of inclinations are 0.004 or more is 15% or less, in a case where samples of inclinations on a main surface are obtained at intervals of 10 nm.
    Type: Application
    Filed: March 28, 2019
    Publication date: July 25, 2019
    Inventors: Masanobu ITAYA, Kinobu OSAKABE, Toshio TAKIZAWA
  • Patent number: 10319403
    Abstract: A magnetic-disk substrate has a pair of main surfaces and arithmetic average roughnesses Ra of the main surfaces are each 0.11 nm or less. Also, in surface unevenness of the main surfaces, an average area of regions occupied by a plurality of protrusions having a height of 0.1 nm or more from an average plane of the surface unevenness is 25 nm2/protrusion or less. The arithmetic average roughness Ra and the surface unevenness are measured using an atomic force microscope with a probe having a probe tip provided with a carbon nanofiber rod-shaped member.
    Type: Grant
    Filed: March 31, 2016
    Date of Patent: June 11, 2019
    Assignee: HOYA CORPORATION
    Inventors: Masanobu Itaya, Kinobu Osakabe
  • Patent number: 10283156
    Abstract: A magnetic-disk glass substrate of the present invention has an average value of squares of inclinations of 0.0025 or less and a frequency at which squares of inclinations are 0.004 or more of 15% or less, in a case where samples of inclinations on a main surface are obtained at intervals of 10 nm.
    Type: Grant
    Filed: January 9, 2017
    Date of Patent: May 7, 2019
    Assignees: HOYA CORPORATION, HOYA GLASS DISK VIETNAM II LTD.
    Inventors: Masanobu Itaya, Kinobu Osakabe, Toshio Takizawa
  • Publication number: 20180005659
    Abstract: A magnetic-disk substrate has a pair of main surfaces and arithmetic average roughnesses Ra of the main surfaces are each 0.11 nm or less. Also, in surface unevenness of the main surfaces, an average area of regions occupied by a plurality of protrusions having a height of 0.1 [nm] or more from an average plane of the surface unevenness is 25 [nm2/protrusion] or less. The arithmetic average roughness Ra and the surface unevenness are measured using an atomic force microscope with a probe having a probe tip provided with a carbon nanofiber rod-shaped member.
    Type: Application
    Filed: March 31, 2016
    Publication date: January 4, 2018
    Applicant: Hoya Corporation
    Inventors: Masanobu ITAYA, Kinobu OSAKABE
  • Publication number: 20170194025
    Abstract: A magnetic-disk glass substrate according to the present invention is a doughnut-shaped magnetic-disk glass substrate having a circular hole provided in the center, a pair of main surfaces, and an outer circumferential end surface and an inner circumferential end surface each including a side wall surface and a chamfered surface that is formed between each main surface and the side wall surface. A measurement point is provided on the outer circumferential end surface every 30 degrees in the circumferential direction with reference to a center of the glass substrate, and when a curvature radius of a shape of a portion between the side wall surface and the chamfered surface is determined at each measurement point, the difference in the curvature radius between neighboring measurement points is 0.01 mm or less.
    Type: Application
    Filed: March 23, 2017
    Publication date: July 6, 2017
    Inventors: Masanobu ITAYA, Kinobu OSAKABE
  • Publication number: 20170186459
    Abstract: A magnetic-disk glass substrate of the present invention has an average value of squares of inclinations of 0.0025 or less and a frequency at which squares of inclinations are 0.004 or more of 15% or less, in a case where samples of inclinations on a main surface are obtained at intervals of 10 nm.
    Type: Application
    Filed: January 9, 2017
    Publication date: June 29, 2017
    Applicants: HOYA CORPORATION, HOYA GLASS DISK VIETNAM II LTD.
    Inventors: Masanobu ITAYA, Kinobu OSAKABE, Toshio TAKIZAWA
  • Patent number: 9607647
    Abstract: A magnetic-disk glass substrate of the present invention has a pair of main surfaces, and an arithmetic mean roughness (Ra) for wavelength components of 10 to 50 nm of the surface of the main surfaces is 0.15 nm or less.
    Type: Grant
    Filed: September 30, 2013
    Date of Patent: March 28, 2017
    Assignee: HOYA CORPORATION
    Inventors: Masanobu Itaya, Kinobu Osakabe
  • Patent number: 9564166
    Abstract: A magnetic-disk glass substrate of the present invention has an average value of squares of inclinations of 0.0025 or less and a frequency at which squares of inclinations are 0.004 or more of 15% or less, in a case where samples of inclinations on a main surface are obtained at intervals of 10 nm.
    Type: Grant
    Filed: June 28, 2013
    Date of Patent: February 7, 2017
    Assignees: HOYA CORPORATION, HOYA GLASS DISK VIETNAM II LTD.
    Inventors: Masanobu Itaya, Kinobu Osakabe, Toshio Takizawa
  • Publication number: 20150248910
    Abstract: A magnetic-disk glass substrate of the present invention has a pair of main surfaces, and an arithmetic mean roughness (Ra) for wavelength components of 10 to 50 nm of the surface of the main surfaces is 0.15 nm or less.
    Type: Application
    Filed: September 30, 2013
    Publication date: September 3, 2015
    Applicant: HOYA CORPORATION
    Inventors: Masanobu Itaya, Kinobu Osakabe
  • Publication number: 20150213826
    Abstract: A magnetic-disk glass substrate of the present invention has an average value of squares of inclinations of 0.0025 or less and a frequency at which squares of inclinations are 0.004 or more of 15% or less, in a case where samples of inclinations on a main surface are obtained at intervals of 10 nm.
    Type: Application
    Filed: June 28, 2013
    Publication date: July 30, 2015
    Applicants: HOYA GLASS DISK VIETNAM II LTD., HOYA CORPORATION
    Inventors: Masanobu Itaya, Kinobu Osakabe, Toshio Takizawa