公开(公告)号：US20240096367A1

公开(公告)日：2024-03-21

申请号：US18498739

申请日：2023-10-31

Applicant: FUJIFILM Corporation

Inventor： Norihito KASADA

IPC: G11B5/71 ,  G11B5/702 ,  G11B5/708 ,  G11B5/735

CPC classification number: G11B5/71 ,  G11B5/7028 ,  G11B5/7085 ,  G11B5/7356

Abstract: A magnetic tape in which a C—H derived C concentration calculated from a C—H peak surface area ratio in C1s spectra obtained by XPS performed on a surface of the magnetic layer at a photoelectron take-off angle of 10 degrees is 45 atom % to 65 atom %, and in an environment with a temperature of 23° C. and a relative humidity of 50%, an AlFeSil abrasion value45° of the surface of the magnetic layer measured at a tilt angle of 45° of an AlFeSil prism is 20 μm to 50 μm, a standard deviation of an AlFeSil abrasion value of the surface of the magnetic layer measured at each of given tilt angles of the AlFeSil prism is 30 μm or less, and the tilt angle of the AlFeSil prism is an angle formed by a longitudinal direction of the AlFeSil prism and a width direction of the magnetic tape.

公开(公告)号：US20240096366A1

公开(公告)日：2024-03-21

申请号：US18517638

申请日：2023-11-22

Applicant: FUJIFILM Corporation

Inventor： Norihito KASADA

IPC: G11B5/708 ,  G11B5/735

CPC classification number: G11B5/7085 ,  G11B5/7356

Abstract: A magnetic tape in which an edge weave amount of a tape edge on at least one side of the magnetic tape is 1.5 um or less, and in an environment with a temperature of 23° C. and a relative humidity of 50%, an AlFeSil abrasion value45° of a surface of the magnetic layer measured at a tilt angle of 45° of an AlFeSil prism is 20 μm to 50 μm, a standard deviation of an AlFeSil abrasion value of the surface of the magnetic layer measured at each of tilt angles of 0°, 15°, 30°, and 45° of the AlFeSil prism is 30 μm or less, and the tilt angle of the AlFeSil prism is an angle formed by a longitudinal direction of the AlFeSil prism and a width direction of the magnetic tape.

公开(公告)号：US20240013807A1

公开(公告)日：2024-01-11

申请号：US18330717

申请日：2023-06-07

Applicant: FUJIFILM Corporation

Inventor： Norihito KASADA

IPC: G11B23/107 ,  G11B5/78 ,  G11B15/43 ,  G11B23/027

CPC classification number: G11B23/107 ,  G11B5/78 ,  G11B15/43 ,  G11B23/027

Abstract: Provided is a magnetic tape apparatus in which the magnetic tape is run between a winding reel and a cartridge reel in a state where a tension is applied in a longitudinal direction, a maximum value of the tension is 0.50 N or more, the magnetic tape after being run in a state where the tension is applied is wound around the cartridge reel with a tension of 0.30 N or less applied in the longitudinal direction, and the number of recesses existing on a surface of the magnetic layer of the magnetic tape and having an equivalent circle diameter of 0.10 μm or more and less than 0.20 μm is 100 or more and 2000 or less per an area of 40 μm×40 μm.

公开(公告)号：US20230115333A1

公开(公告)日：2023-04-13

申请号：US17955113

申请日：2022-09-28

Applicant: FUJIFILM Corporation

Inventor： Norihito KASADA

IPC: G11B5/706 ,  G11B5/78 ,  G11B5/733

Abstract: A magnetic tape in which an arithmetic average roughness Ra measured at a surface of a magnetic layer with an atomic force microscope is 2.0 nm or less, and in an environment with a temperature of 32° C. and a relative humidity of 80%, a frictional force F45° on the surface of the magnetic layer with respect to an LTO8 head measured at a head tilt angle of 45° is 4 gf to 15 gf, and a standard deviation of a frictional force F on the surface of the magnetic layer with respect to the LTO8 head measured at each of head tilt angles of 0°, 15°, 30°, and 45° is 10 gf or less.

公开(公告)号：US20230099064A1

公开(公告)日：2023-03-30

申请号：US17953149

申请日：2022-09-26

Applicant: FUJIFILM Corporation

Inventor： Yujin SHIBATA ,  Norihito KASADA ,  Takuto KUROKAWA ,  So MATSUYAMA

IPC: G11B5/65 ,  G11B23/107 ,  G11B5/008 ,  G11B5/584 ,  G11B5/733 ,  G11B5/78

Abstract: The magnetic tape includes a non-magnetic support, and a magnetic layer containing a ferromagnetic powder, in which an edge portion Ra which is an arithmetic average roughness Ra measured at an edge portion of a surface of the magnetic layer is 1.50 nm or less, a central portion Ra which is an arithmetic average roughness Ra measured at a central portion of the surface of the magnetic layer is 0.30 nm to 1.30 nm, and a Ra ratio (central portion Ra/edge portion Ra) is 0.75 to 0.95.

公开(公告)号：US20220277772A1

公开(公告)日：2022-09-01

申请号：US17680904

申请日：2022-02-25

Applicant: FUJIFILM Corporation

Inventor： Shota KAMIMURA ,  Yuto MURATA ,  Tomohide UEYAMA ,  Norihito KASADA

IPC: G11B23/04 ,  G11B23/037 ,  G11B23/107 ,  B65H75/14 ,  G11B5/716

Abstract: The magnetic tape container includes a core around which a magnetic tape is wound. The magnetic tape includes a non-magnetic support, and a magnetic layer including a ferromagnetic powder. A maximum value of a deviation of a center position of an average minimum region reference circle of a trajectory of one rotation drawn by the magnetic tape, in a case where the wound magnetic tape is drawn out from the core core is 100 μm or less for three points of the magnetic tape in a width direction.

公开(公告)号：US20220036918A1

公开(公告)日：2022-02-03

申请号：US17500337

申请日：2021-10-13

Applicant: FUJIFILM Corporation

Inventor： Norihito KASADA

IPC: G11B5/702 ,  G11B5/706

Abstract: The magnetic recording medium includes a non-magnetic support; and a magnetic layer including ferromagnetic powder and a binding agent on the non-magnetic support, in which an isoelectric point of a surface zeta potential of the magnetic layer is equal to or greater than 5.5.

公开(公告)号：US20220028421A1

公开(公告)日：2022-01-27

申请号：US17378782

申请日：2021-07-19

Applicant: FUJIFILM Corporation

Inventor： Yusuke KANEKO ,  Norihito KASADA

IPC: G11B5/73

Abstract: The magnetic tape cartridge includes a magnetic tape that is accommodated in the magnetic tape cartridge while being wound around a reel hub. A water absorption amount of the magnetic tape measured after the magnetic tape cartridge is stored in a storage environment of a temperature of 32° C. and a relative humidity of 80% for 10 days is 0.30 g or less as a value in terms of a length of the magnetic tape of 1000 m, and the water absorption amount is a value measured in a measurement environment with a temperature of 21° C. and a relative humidity of 50% within 1 hour after the storage.

公开(公告)号：US20210375316A1

公开(公告)日：2021-12-02

申请号：US17331654

申请日：2021-05-27

Applicant: FUJIFILM Corporation

Inventor： Norihito KASADA

IPC: G11B15/093 ,  G11B5/008 ,  G11B15/32

Abstract: A magnetic tape device, in which a magnetic tape is caused to run between a winding reel and a cartridge reel in a state where a tension is applied in a longitudinal direction of the magnetic tape and a maximum value of the tension is 0.50 N or more, and the magnetic tape after running in a state where the tension is applied is caused to be wound around the cartridge reel by applying a tension of 0.40 N or less in the longitudinal direction of the magnetic tape, and a residual elongation of the magnetic tape is 0.05% or less.

公开(公告)号：US20210287709A1

公开(公告)日：2021-09-16

申请号：US17196376

申请日：2021-03-09

Applicant: FUJIFILM Corporation

Inventor： Takashi FUJIMOTO ,  Norihito KASADA ,  Eiki OZAWA

IPC: G11B5/706 ,  G11B5/735 ,  G11B5/008 ,  G11B5/714

Abstract: The magnetic tape includes a non-magnetic support and a magnetic layer including ferromagnetic powder, in which the ferromagnetic powder is ε-iron oxide powder, and a coefficient of variation of particle size of the ε-iron oxide powder in a longitudinal direction of the magnetic layer is more than 5.00% and 15.00% or less.