公开(公告)号：US20200027481A1

公开(公告)日：2020-01-23

申请号：US16499210

申请日：2018-07-02

申请人： HOYA CORPORATION

发明人： Kinobu OSAKABE

IPC分类号： G11B5/73

摘要： A substrate for a magnetic disk includes a substrate main body having two main surfaces, and a film that is provided on the main surfaces and is made of a material having a loss factor of 0.1 or more. The substrate for a magnetic disk including the film has a thickness T of 0.700 mm or less, and a thickness D [mm] of the film provided on the main surfaces and the thickness T [mm] of the substrate for a magnetic disk including the film satisfy a relationship D≥0.0082/T−0.0015.

公开(公告)号：US20210375313A1

公开(公告)日：2021-12-02

申请号：US17385787

申请日：2021-07-26

申请人： HOYA CORPORATION

发明人： Masanobu ITAYA ,  Kinobu OSAKABE

IPC分类号： G11B5/82 ,  G11B5/84 ,  G11B5/73

摘要： 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.

公开(公告)号：US20210264946A1

公开(公告)日：2021-08-26

申请号：US17315109

申请日：2021-05-07

申请人： HOYA CORPORATION

发明人： Shinji EDA ,  Kinobu OSAKABE ,  Yoshitake TANNO ,  Mikio IKENISHI

IPC分类号： G11B17/32 ,  G11B5/73 ,  G11B17/038 ,  G11B33/12

摘要： A ring shaped glass spacer is configured to be arranged in contact with a magnetic disk in a hard disk drive apparatus. A surface resistivity of a surface of a glass material of the glass spacer at 22 (° C.) is lower than a surface resistivity of an inner portion of the glass material at 22 (° C.).

公开(公告)号：US20200227087A1

公开(公告)日：2020-07-16

申请号：US16641399

申请日：2019-01-31

申请人： HOYA CORPORATION

发明人： Shinji EDA ,  Kinobu OSAKABE ,  Yoshitake TANNO ,  Mikio IKENISHI

IPC分类号： G11B17/32 ,  G11B5/73 ,  G11B33/12 ,  G11B17/038

摘要： A glass material of a glass spacer has a surface resistivity of 103 to 109 [Ω/sq] at 22 [° C.]. The surface resistivity of a surface of the glass material of the glass spacer at 22 [° C.] is lower than the surface resistivity of an inner portion of the glass material at 22 [° C.]. The glass spacer contains at least one oxide selected from the group consisting of TiO2, Nb2O5, WO3, and Bi2O3, as a glass component.

公开(公告)号：US20190251993A1

公开(公告)日：2019-08-15

申请号：US16395850

申请日：2019-04-26

申请人： HOYA CORPORATION

发明人： Masanobu ITAYA ,  Kinobu OSAKABE

IPC分类号： G11B5/82 ,  G11B5/84

CPC分类号： G11B5/82 ,  B82Y10/00 ,  B82Y40/00 ,  G11B5/73 ,  G11B5/7315 ,  G11B5/84 ,  G11B5/8404

摘要： 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.

公开(公告)号：US20170194025A1

公开(公告)日：2017-07-06

申请号：US15467492

申请日：2017-03-23

申请人： HOYA CORPORATION

发明人： Masanobu ITAYA ,  Kinobu OSAKABE

IPC分类号： G11B5/73

CPC分类号： G11B5/7315 ,  C23C14/35 ,  G11B5/73 ,  G11B5/739 ,  G11B5/73921

摘要： 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.

公开(公告)号：US20240282337A1

公开(公告)日：2024-08-22

申请号：US18590811

申请日：2024-02-28

申请人： HOYA CORPORATION

发明人： Kinobu OSAKABE

IPC分类号： G11B5/73 ,  G11B5/82

CPC分类号： G11B5/73917 ,  G11B5/73915 ,  G11B5/73919 ,  G11B5/73921 ,  G11B5/82

摘要： A substrate for a magnetic disk includes a substrate main body and a film. The substrate main body has two opposing main surfaces and an outer circumferential edge surface, and the outer circumferential edge surface includes a side wall surface, which is orthogonal to the main surfaces, and chamfered surfaces, which are disposed between the main surfaces and the side wall surface. The substrate main body is a glass substrate main body or an aluminum alloy substrate main body, and has a disk shape. The film is an alloy film containing Ni and P, and is provided on a surface of the substrate main body such that the film is formed continuously over the main surfaces, the chamfered surfaces, and the side wall surface of the substrate main body.

公开(公告)号：US20210264943A1

公开(公告)日：2021-08-26

申请号：US17315145

申请日：2021-05-07

申请人： HOYA CORPORATION

发明人： Kinobu OSAKABE

IPC分类号： G11B5/73 ,  G11B5/82

摘要： A non magnetic substrate for a magnetic disk includes a substrate main body having two opposing main surfaces and being a glass substrate main body or an aluminum alloy substrate main body, and a metal film made of an Ni—P alloy and provided on the main surfaces and an outer circumferential edge surface of the substrate main body. The non magnetic substrate has a thickness (T+D) of 0.57 mm or less, which is the sum of a thickness T of the substrate main body and a thickness D of the metal film. The non magnetic substrate has a diameter of 90 mm or more. A ratio D/T is 0.025 or more. The outer circumferential edge surface of the substrate main body forming an interface with the metal film has a surface roughness maximum height Rz of 0.5 μm or more.

公开(公告)号：US20150262605A1

公开(公告)日：2015-09-17

申请号：US14665857

申请日：2015-03-23

申请人： HOYA CORPORATION

发明人： Yoichi HACHITANI ,  Kinobu OSAKABE

IPC分类号： G11B5/73 ,  C03C3/097 ,  C03C3/095

CPC分类号： G11B5/7315 ,  C03C3/083 ,  C03C3/085 ,  C03C3/087 ,  C03C3/095 ,  C03C3/097 ,  G11B5/8404 ,  Y10T428/315

摘要： The provided are a glass for a magnetic recording medium substrate permitting the realization of a magnetic recording medium substrate affording good chemical durability and having an extremely flat surface, a magnetic recording medium substrate comprised of this glass, a magnetic recording medium equipped with this substrate, and methods of manufacturing the same. Glasses for a magnetic recording medium substrate are, glass I comprised of an oxide glass, comprising, denoted as mass percentages: Si 20 to 40 percent, Al 0.1 to 10 percent, Li 0.1 to 5 percent, Na 0.1 to 10 percent, K 0 to 5 percent (where the total content of Li, Na, and K is 15 percent or less), Sn 0.005 to 0.6 percent, and Ce 0 to 1.2 percent; the Sb content is 0 to 0.1 percent; and not comprising As or F; glass II comprised of oxide glass, comprising, as converted based on the oxide, denoted as molar percentages: SiO2 60 to 75 percent, Al2O3 1 to 15 percent, Li2O 0.1 to 20 percent, Na2O 0.1 to 15 percent, and K2O 0 to 5 percent (where the total content of Li2O, Na2O, and K2O is 25 percent or lower); based on the total amount of the glass components, 0.01 to 0.7 mass percent of Sn oxide and 0 to 1.4 mass percent of Ce oxide are added; the content of Sb oxide is 0 to 0.1 mass percent; and not comprising As or F; and glass III comprised of oxide glass, comprising, converted based on the oxide, denoted as molar percentages: SiO2 60 to 75 percent, Al2O3 1 to 15 percent, Li2O 0.1 to 20 percent, Na2O 0.1 to 15 percent, K2O 0 to 5 percent (where the total content of Li2O, Na2O, and K2O is 25 percent or less); by comprising a 0.1 to 3.5 mass percent of total content of Sn oxide and Ce oxide, based on the total amount of the glass components; the ratio of the Sn oxide content to the total content of Sn oxide and Ce oxide (Sn oxide content/(Sn oxide content+Ce oxide content)) is 0.01 to 0.99; the Sb oxide content is 0 to 0.1 percent; and comprising no As or F.

公开(公告)号：US20230298623A1

公开(公告)日：2023-09-21

申请号：US18321166

申请日：2023-05-22

申请人： HOYA CORPORATION

发明人： Kinobu OSAKABE

IPC分类号： G11B5/73

CPC分类号： G11B5/73921 ,  G11B5/739 ,  G11B5/73911 ,  G11B5/73917 ,  G11B5/73919

摘要： A substrate for a magnetic disk includes a substrate main body having two main surfaces and an outer circumferential edge surface, and a film that is an alloy film containing Ni and P and provided on a surface of the substrate main body. A disk shape of the substrate main body has an outer diameter of 90 mm or more. A thickness T of the substrate that includes film thicknesses of sections of the film provided on the main surfaces is 0.520 mm or less. A total thickness D mm, which is a sum of the film thicknesses of the sections of the film on the main surfaces and the thickness T mm satisfy D≥0.0082/T−0.0015. A surface roughness maximum height Rz of the film provided on the outer circumferential edge surface is smaller than that of the substrate main body at the outer circumferential edge surface.