公开(公告)号：US20210375315A1

公开(公告)日：2021-12-02

申请号：US17331649

申请日：2021-05-27

Applicant: FUJIFILM Corporation

Inventor： Norihito KASADA

IPC: G11B15/093 ,  G11B5/008

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 an adhesive strength of the magnetic layer of the magnetic tape is 1.0 N or more, and an adhesive strength of the back coating layer is 1.0 N or more.

公开(公告)号：US20210375307A1

公开(公告)日：2021-12-02

申请号：US17333019

申请日：2021-05-28

Applicant: FUJIFILM Corporation

Inventor： Norihito KASADA

IPC: G11B5/008

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, 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, and a number distribution A of equivalent circle diameters of a plurality of bright areas and a number distribution B of equivalent circle diameters of a plurality of dark areas in a binarized image of a secondary electron image obtained by imaging a surface of the magnetic layer of the magnetic tape with a scanning electron microscope satisfy predetermined number distributions, respectively.w

公开(公告)号：US20210287711A1

公开(公告)日：2021-09-16

申请号：US17199669

申请日：2021-03-12

Applicant: FUJIFILM Corporation

Inventor： Takashi FUJIMOTO ,  Norihito KASADA ,  Eiki OZAWA

IPC: G11B5/706

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 0.50% or more and 5.00% or less.

公开(公告)号：US20210280212A1

公开(公告)日：2021-09-09

申请号：US17328620

申请日：2021-05-24

Applicant: FUJIFILM Corporation

Inventor： Norihito KASADA

IPC: G11B5/735 ,  G11B23/107 ,  G11B5/706 ,  G11B5/596 ,  G11B5/70

Abstract: Provided are a magnetic tape including: a non-magnetic support; and a magnetic layer including ferromagnetic powder and a binding agent on the non-magnetic support, in which a total thickness of the magnetic tape is equal to or smaller than 5.30 μm, the magnetic layer has a servo pattern, a center line average surface roughness Ra measured on a surface of the magnetic layer is equal to or smaller than 1.8 nm, and an absolute value ΔN of a difference between a refractive index Nxy of the magnetic layer, measured in an in-plane direction and a refractive index Nz of the magnetic layer, measured in a thickness direction is 0.25 to 0.40, a magnetic tape cartridge and a magnetic tape apparatus including this magnetic tape, a magnetic tape cartridge and a magnetic tape apparatus including this magnetic tape.

公开(公告)号：US20210233563A1

公开(公告)日：2021-07-29

申请号：US17155536

申请日：2021-01-22

Applicant: FUJIFILM Corporation

Inventor： Atsushi MUSHA ,  So MATSUYAMA ,  Norihito KASADA

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

Abstract: In the magnetic recording and reproducing device, a distal end width of the first magnetic pole in the recording element is substantially the same as a distal end width of the second magnetic pole; the reproducing element width of the reproducing element is equal to or less than 0.8 μm; and in the magnetic recording medium, a number distribution A of equivalent circle diameters of a plurality of bright areas in a binarized image of a secondary electron image obtained by imaging a surface of the magnetic layer with a scanning electron microscope at an acceleration voltage of 5 kV, and a number distribution B of equivalent circle diameters of a plurality of dark areas in a binarized image of a secondary electron image obtained by imaging the surface of the magnetic layer with a scanning electron microscope at an acceleration voltage of 2 kV satisfy predetermined number distribution, respectively. w

公开(公告)号：US20210233561A1

公开(公告)日：2021-07-29

申请号：US17155738

申请日：2021-01-22

Applicant: FUJIFILM Corporation

Inventor： Norihito KASADA

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

Abstract: In the magnetic recording medium, a number distribution A of a plurality of bright regions, based on equivalent circle diameters thereof, in a binarized image of a secondary electron image obtained by imaging a surface of the magnetic layer by a scanning electron microscope at an acceleration voltage of 5 kV and a number distribution B of a plurality of dark regions, based on equivalent circle diameters thereof, in a binarized image of a secondary electron image obtained by imaging a surface of the magnetic layer by a scanning electron microscope at an acceleration voltage of 2 kV respectively satisfy a predetermined number distribution.

公开(公告)号：US20210090600A1

公开(公告)日：2021-03-25

申请号：US17022446

申请日：2020-09-16

Applicant: FUJIFILM Corporation

Inventor： Takuto KUROKAWA ,  Naoki SANO ,  Norihito KASADA ,  Eiki OZAWA ,  Megumi NAKANO

IPC: G11B5/72 ,  G11B5/733 ,  G11B5/73 ,  G11B5/712 ,  G11B5/008

Abstract: The magnetic recording medium includes a non-magnetic support; a magnetic layer that includes ferromagnetic powder on one surface side of the non-magnetic support; and a back coating layer that includes non-magnetic powder on the other surface side of the non-magnetic support, in which a difference between a spacing measured on a surface of the back coating layer by optical interferometry under a pressure of 0.5 atm after n-hexane cleaning and a spacing measured on the surface of the back coating layer by optical interferometry under a pressure of 13.5 atm after n-hexane cleaning is 3 nm or less.

公开(公告)号：US20200312361A1

公开(公告)日：2020-10-01

申请号：US16831158

申请日：2020-03-26

Applicant: FUJIFILM Corporation

Inventor： Norihito KASADA

IPC: G11B5/706 ,  G11B5/008 ,  G11B5/735 ,  G11B5/714 ,  G11B5/712

Abstract: The magnetic tape includes: a non-magnetic support; and a magnetic layer including ferromagnetic powder, in which the ferromagnetic powder is ferromagnetic powder selected from the group consisting of hexagonal strontium ferrite powder and ε-iron oxide powder, and an amount of an edge weave of a tape edge on at least one side of the magnetic tape is 1.5 μm or less.

公开(公告)号：US20200211592A1

公开(公告)日：2020-07-02

申请号：US16727181

申请日：2019-12-26

Applicant: FUJIFILM Corporation

Inventor： Norihito KASADA

IPC: G11B5/735 ,  G11B5/596 ,  G11B5/706 ,  G11B23/107

Abstract: Provided are a magnetic tape including: a non-magnetic support; and a magnetic layer including ferromagnetic powder and a binding agent on the non-magnetic support, in which a total thickness of the magnetic tape is equal to or smaller than 5.30 μm, the magnetic layer has a servo pattern, a center line average surface roughness Ra measured on a surface of the magnetic layer is equal to or smaller than 1.8 nm, and an absolute value ΔN of a difference between a refractive index Nxy of the magnetic layer, measured in an in-plane direction and a refractive index Nz of the magnetic layer, measured in a thickness direction is 0.25 to 0.40, a magnetic tape cartridge and a magnetic tape apparatus including this magnetic tape, a magnetic tape cartridge and a magnetic tape apparatus including this magnetic tape.

公开(公告)号：US20200005820A1

公开(公告)日：2020-01-02

申请号：US16456965

申请日：2019-06-28

Applicant: FUJIFILM Corporation

Inventor： Eiki OZAWA ,  Norihito KASADA ,  Atsushi MUSHA

IPC: G11B5/596 ,  G11B5/71 ,  G11B5/012 ,  G11B15/46

Abstract: A magnetic tape apparatus, in which a tilt cos θ of the hexagonal ferrite powder with respect to a surface of the magnetic layer acquired by cross section observation by STEM is 0.85 to 1.00, a reading element unit includes a plurality of reading elements each of which reads data by a linear scanning method from a specific track region including a reading target track in a track region included in the magnetic tape, an extraction unit performs a waveform equalization process according to a deviation amount between positions of the magnetic tape and the reading element unit, with respect to each reading result for each reading element, to extract data derived from the reading target track from the reading result, and the deviation amount is determined in accordance with a result obtained by reading of the servo pattern included in the magnetic layer by a servo element.