公开(公告)号：US20250014604A1

公开(公告)日：2025-01-09

申请号：US18758395

申请日：2024-06-28

Applicant: FUJIFILM Corporation

Inventor： Norihito KASADA ,  Nobuhito ONOZUKA ,  Junya SAWADA ,  Ryosuke YUMIYAMA

IPC: G11B5/78 ,  G11B5/55 ,  G11B5/592 ,  G11B5/706 ,  G11B5/714 ,  G11B5/735

Abstract: The magnetic tape includes a non-magnetic support, and a magnetic layer containing a ferromagnetic powder. A magnetic tape cartridge and a magnetic tape apparatus include the magnetic tape. Sci obtained by measuring a surface of the magnetic layer with an atomic force microscope and by Equation A is 1.40 or more and 1.60 or less, and standard deviation σ of the Sci in a width direction of the surface of the magnetic layer is 0.05 or less. In Equation A, Sq is a root-mean-square height Sq specified in ISO 25178, Vv(h0.05)-Vv(h0.8) is a void volume in a region where a load area ratio in a bearing curve is 5% or more and 80% or less, and A is a measurement region area. Sci = ( Vv ⁢ ( h 0.05 ) - Vv ⁢ ( h 0.8 ) A ) / Sq Equation ⁢ A

公开(公告)号：US20250014603A1

公开(公告)日：2025-01-09

申请号：US18758784

申请日：2024-06-28

Applicant: FUJIFILM Corporation

Inventor： Ryosuke YUMIYAMA ,  Norihito KASADA ,  Nobuhito ONOZUKA ,  Junya SAWADA

IPC: G11B5/73 ,  G11B5/78

Abstract: The magnetic tape includes a non-magnetic support, and a magnetic layer containing a ferromagnetic powder. A magnetic tape cartridge and a magnetic tape apparatus include the magnetic tape. An arithmetic average curvature Spc of a peak point specified in ISO 25178 on a surface of the magnetic layer is 0.30 (1/μm) or more and 0.70 (1/μm) or less, and standard deviation a of the Spc in a width direction of the surface of the magnetic layer is 0.15 (1/μm) or less.

公开(公告)号：US20250006225A1

公开(公告)日：2025-01-02

申请号：US18759153

申请日：2024-06-28

Applicant: FUJIFILM Corporation

Inventor： Junya SAWADA ,  Norihito KASADA ,  Nobuhito ONOZUKA ,  Ryosuke YUMIYAMA

IPC: G11B5/706 ,  G11B5/592 ,  G11B5/714 ,  G11B5/735 ,  G11B5/78

Abstract: The magnetic tape includes a non-magnetic support, and a magnetic layer containing a ferromagnetic powder. A magnetic tape cartridge and a magnetic tape apparatus include the magnetic tape. A dale void volume Vvv specified in ISO 25178 on a surface of the magnetic layer is 0.100 nm3 or more and 0.350 nm3 or less, and standard deviation a of the Vvv in a width direction of the surface of the magnetic layer is 0.020 nm3 or less.

公开(公告)号：US20230154491A1

公开(公告)日：2023-05-18

申请号：US18052406

申请日：2022-11-03

Applicant: FUJIFILM Corporation

Inventor： Junya SAWADA ,  Noriko Oyanagi

IPC: G11B5/66 ,  G11B5/708 ,  G11B5/735

CPC classification number: G11B5/676 ,  G11B5/7085 ,  G11B5/7356 ,  G11B5/00813

Abstract: The magnetic recording medium includes a non-magnetic support; and a magnetic layer containing a ferromagnetic powder, in which the magnetic layer includes an abrasive, the abrasive is a carbide, an average primary particle diameter of the abrasive is 10 nm or more and 100 nm or less, and in an electron microscope image of a surface of the magnetic layer, assuming that a total area occupied by the abrasive is 100%, a ratio of an area occupied by the abrasive present in an aggregated state having a maximum Feret diameter of 0.2 µm or more is 50% or more.