公开(公告)号：US10811048B2

公开(公告)日：2020-10-20

申请号：US16777279

申请日：2020-01-30

Applicant: FUJIFILM Corporation

Inventor： Eiki Ozawa ,  Norihito Kasada ,  Atsushi Musha

IPC: G11B15/18 ,  G11B5/706 ,  G11B20/12 ,  G11B5/584 ,  G11B5/708 ,  G11B5/702 ,  G11B23/50 ,  G01B11/06 ,  G11B20/10 ,  G11B5/39 ,  G11B5/78 ,  G11B27/022 ,  G11B5/71 ,  G11B5/00 ,  B82Y25/00 ,  B82Y10/00

Abstract: The magnetic tape includes a non-magnetic support and a magnetic layer, in which the magnetic layer has a timing-based servo pattern, an edge shape of the timing-based servo pattern, specified by magnetic force microscopy is a shape in which a difference between a value L99.9 of a cumulative distribution function of 99.9% and a value L0.1 of a cumulative distribution function of 0.1% in a position deviation width from an ideal shape of the magnetic tape in a longitudinal direction is 180 nm or less, and a difference between a spacing S0.5 measured, after n-hexane cleaning, on a surface of the magnetic layer under a pressure of 0.5 atm by optical interferometry and a spacing S13.5 measured, after n-hexane cleaning, under a pressure of 13.5 atm is 3.0 nm or less, and S0.5 is 5.0 nm or more.

公开(公告)号：US10692528B2

公开(公告)日：2020-06-23

申请号：US16456459

申请日：2019-06-28

Applicant: FUJIFILM Corporation

Inventor： Eiki Ozawa ,  Norihito Kasada ,  Atsushi Musha

IPC: G11B5/09 ,  G11B20/10 ,  G11B5/78 ,  G11B5/584 ,  G11B5/008

Abstract: A magnetic tape apparatus, in which full widths at half maximum of spacing distribution measured by optical interferometry regarding a surface of a magnetic layer before and after performing a vacuum heating with respect to the magnetic tape are greater than 0 nm and equal to or smaller than 15.0 nm, a difference between spacings measured by optical interferometry regarding the surface of the magnetic layer before and after performing the vacuum heating is greater than 0 nm and equal to or smaller than 12.0 nm, and the 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.

公开(公告)号：US12136438B2

公开(公告)日：2024-11-05

申请号：US18320418

申请日：2023-05-19

Applicant: FUJIFILM CORPORATION

Inventor： Yusuke Kaneko ,  Toru Nakao ,  Atsushi Musha ,  Norihito Kasada

IPC: G11B23/04 ,  G11B15/06 ,  G11B15/43

Abstract: A magnetic tape cartridge includes a case in which a magnetic tape is housed, and an NVM of a cartridge memory provided in the case. The NVM stores cartridge information including an identification ID regarding an allowable range of temperature/humidity in using the magnetic tape, an upper limit of a preservation period of the magnetic tape, and an upper limit of a use frequency of the magnetic tape.

公开(公告)号：US12073853B2

公开(公告)日：2024-08-27

申请号：US18163606

申请日：2023-02-02

Applicant: FUJIFILM Corporation

Inventor： Toru Nakao ,  Norihito Kasada ,  Tetsuya Kaneko ,  Atsushi Musha

IPC: G11B5/008 ,  G11B5/78

CPC classification number: G11B5/00813 ,  G11B5/78

Abstract: Provided is a magnetic tape cartridge including: a case in which a magnetic tape on which a plurality of servo bands are formed is accommodated; and a storage medium provided in the case, in which the plurality of servo bands are formed at positions spaced apart from each other in a width direction of the magnetic tape along an entire length direction of the magnetic tape, and the storage medium stores pitch information capable of specifying a pitch in the width direction between the plurality of servo bands and distance information capable of specifying a distance between a plurality of servo reading elements that have read the plurality of servo bands.

公开(公告)号：US11430476B2

公开(公告)日：2022-08-30

申请号：US17242798

申请日：2021-04-28

Applicant: FUJIFILM Corporation

Inventor： Norihito Kasada ,  Eiki Ozawa ,  Atsushi Musha

IPC: G11B5/584 ,  G11B5/706 ,  G11B5/702 ,  G11B5/708 ,  G11B5/70 ,  G11B5/39 ,  G11B5/78 ,  G11B27/022 ,  G11B20/10 ,  G11B5/00 ,  B82Y25/00 ,  B82Y10/00

Abstract: The magnetic tape includes a non-magnetic support and a magnetic layer including ferromagnetic powder and a binding agent, in which the magnetic layer has a timing-based servo pattern, an edge shape of the timing-based servo pattern, specified by magnetic force microscopy is a shape in which a difference (L99.9−L0.1) between a value L99.9 of a cumulative distribution function of 99.9% and a value L0.1 of a cumulative distribution function of 0.1% in a position deviation width from an ideal shape of the magnetic tape in a longitudinal direction is 180 nm or less, and an isoelectric point of a surface zeta potential of the magnetic layer is 3.8 or less.

公开(公告)号：US11380357B2

公开(公告)日：2022-07-05

申请号：US17329275

申请日：2021-05-25

Applicant: FUJIFILM Corporation

Inventor： Eiki Ozawa ,  Norihito Kasada ,  Atsushi Musha

IPC: G11B5/70 ,  G11B5/008

Abstract: The magnetic tape includes a non-magnetic support and a magnetic layer, in which an edge shape of the timing-based servo pattern, specified by magnetic force microscopy is a shape in which a difference between a value L99.9 of a cumulative distribution function of 99.9% and a value L0.1 of a cumulative distribution function of 0.1% in a position deviation width from an ideal shape of the magnetic tape in a longitudinal direction is 180 nm or less, and in which a difference between a spacing Safter measured on a surface of the magnetic layer by an optical interferometry after ethanol cleaning and a spacing Sbefore measured on the surface of the magnetic layer by an optical interferometry before ethanol cleaning is greater than 0 nm and 6.0 nm or less.

公开(公告)号：US11264054B2

公开(公告)日：2022-03-01

申请号：US17155695

申请日：2021-01-22

Applicant: FUJIFILM Corporation

Inventor： Norihito Kasada ,  So Matsuyama ,  Atsushi Musha ,  Shota Kamimura

IPC: G11B5/733 ,  G11B5/187 ,  G11B5/008 ,  G11B5/706

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：US11017805B2

公开(公告)日：2021-05-25

申请号：US16795800

申请日：2020-02-20

Applicant: FUJIFILM Corporation

Inventor： Tetsuya Kaneko ,  Atsushi Musha

IPC: G11B5/588 ,  G11B5/55 ,  G11B5/596 ,  G11B5/008 ,  G11B5/584

Abstract: A magnetic tape reading apparatus comprises an acquisition unit that acquires information on linearity of a servo pattern to be recorded on a servo band of a magnetic tape, a reading element unit in which at least two reading elements each of which reads data from a specific track region included in the magnetic tape are disposed, a servo reading element that reads the servo pattern, a control unit that performs control of positioning the reading element unit, a derivation unit that derives a deviation amount, and an extraction unit that extracts data recorded on the reading target track by performing a waveform equalization process on each reading result for the reading elements in accordance with the deviation amount.

公开(公告)号：US10789981B2

公开(公告)日：2020-09-29

申请号：US16401776

申请日：2019-05-02

Applicant: FUJIFILM Corporation

Inventor： Atsushi Musha

IPC: G11B5/09 ,  G11B20/10 ,  G11B5/78 ,  G11B5/584 ,  G11B5/008

Abstract: A magnetic tape reading apparatus includes a reading element unit which includes: a plurality of reading elements which are disposed in a state of being adjacent to each other and 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 a magnetic tape; and an extraction unit which 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.

公开(公告)号：US10755741B2

公开(公告)日：2020-08-25

申请号：US16456780

申请日：2019-06-28

Applicant: FUJIFILM Corporation

Inventor： Eiki Ozawa ,  Norihito Kasada ,  Atsushi Musha

IPC: G11B5/09 ,  G11B20/10 ,  G11B5/008

Abstract: A magnetic tape apparatus includes a magnetic tape, a reading element unit and an extraction unit, in which a coefficient of friction measured regarding a base portion of a surface of the magnetic layer is equal to or smaller than 0.35, the 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, and the 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.