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公开(公告)号:US20200005828A1
公开(公告)日:2020-01-02
申请号:US16456459
申请日:2019-06-28
Applicant: FUJIFILM Corporation
Inventor: Eiki OZAWA , Norihito KASADA , Atsushi MUSHA
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.
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公开(公告)号:US20190304488A1
公开(公告)日:2019-10-03
申请号:US16368044
申请日:2019-03-28
Applicant: FUJIFILM Corporation
Inventor: Eiki OZAWA , Takuto KUROKAWA
Abstract: The magnetic tape includes a non-magnetic support; a magnetic layer including a ferromagnetic powder and a binding agent on one surface of the non-magnetic support; and a back coating layer including a non-magnetic powder and a binding agent on the other surface of the non-magnetic support, in which a center line average surface roughness Ra measured regarding a surface of the back coating layer is equal to or smaller than 7.0 nm, and a difference between a spacing Safter measured by optical interferometry regarding the surface of the back coating layer after methyl ethyl ketone cleaning and a spacing Sbefore measured by optical interferometry regarding the surface of the back coating layer before methyl ethyl ketone cleaning is greater than 0 nm and equal to or smaller than 30.0 nm.
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公开(公告)号:US20190103135A1
公开(公告)日:2019-04-04
申请号:US16143747
申请日:2018-09-27
Applicant: FUJIFILM Corporation
Inventor: Eiki OZAWA , Norihito KASADA
Abstract: Provided are a magnetic recording medium, in which a magnetic layer includes a ferromagnetic hexagonal ferrite powder, a binding agent, and an oxide abrasive, an intensity ratio Int(110)/Int(114) obtained by an X-ray diffraction analysis of the magnetic layer by using an In-Plane method is 0.5 to 4.0, a vertical squareness ratio of the magnetic recording medium is 0.65 to 1.00, a contact angle with respect to 1-bromonaphthalene measured regarding a surface of the magnetic layer is 50.0° to 55.0°, and an average particle diameter of the oxide abrasive obtained from a secondary ion image obtained by irradiating the surface of the magnetic layer with a focused ion beam is 0.04 μm to 0.08 μm, and a magnetic recording and reproducing device including this magnetic recording medium.
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公开(公告)号:US20190051325A1
公开(公告)日:2019-02-14
申请号:US16160377
申请日:2018-10-15
Applicant: FUJIFILM Corporation
Inventor: Norihito KASADA , Eiki OZAWA
Abstract: Provided is a magnetic tape device in which a magnetic tape transportation speed is equal to or lower than 18 m/sec, Ra measured regarding a surface of a magnetic layer of a magnetic tape is equal to or smaller than 2.0 nm, a C—H derived C concentration calculated from a C—H peak area ratio of C1s spectra obtained by X-ray photoelectron spectroscopic analysis performed on the surface of the magnetic layer at a photoelectron take-off angle of 10 degrees is 45 to 65 atom %, and ΔSFD (=SFD25°C.−SFD−190° C.) in a longitudinal direction of the magnetic tape is equal to or smaller than 0.50, with the SFD25° C. being SFD measured in a longitudinal direction of the magnetic tape at a temperature of 25° C., and the SFD−190° C. being SFD measured at a temperature of −190° C.
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公开(公告)号:US20190027175A1
公开(公告)日:2019-01-24
申请号:US16038771
申请日:2018-07-18
Applicant: FUJIFILM Corporation
Inventor: Takuto KUROKAWA , Norihito KASADA , Toshio TADA , Eiki OZAWA
Abstract: The magnetic tape includes a magnetic layer including ferromagnetic powder, non-magnetic powder, and a binding agent and a back coating layer including non-magnetic powder and a binding agent, in which the ferromagnetic powder is ferromagnetic hexagonal ferrite powder, a center line average surface roughness measured regarding a surface of the magnetic layer is equal to or smaller than 1.8 nm, an intensity ratio of a peak intensity of a diffraction peak of a (110) plane with respect to a peak intensity of a diffraction peak of a (114) plane of a hexagonal ferrite crystal structure obtained by an X-ray diffraction analysis of the magnetic layer by using an In-Plane method is 0.5 to 4.0, a vertical squareness ratio of the magnetic tape is 0.65 to 1.00, and a contact angle with respect to 1-bromonaphthalene measured regarding a surface of the back coating layer is 15.0° to 30.0°.
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公开(公告)号:US20180358042A1
公开(公告)日:2018-12-13
申请号:US16044574
申请日:2018-07-25
Applicant: FUJIFILM Corporation
Inventor: Norihito KASADA , Eiki OZAWA
Abstract: The magnetic tape device includes a magnetic tape; and a servo head, in which the servo head is a TMR head, the magnetic tape includes a servo pattern in the magnetic layer, a center line average surface roughness Ra measured regarding a surface of the magnetic layer is equal to or smaller than 2.0 nm, a logarithmic decrement acquired by a pendulum viscoelasticity test performed regarding the surface of the magnetic layer is equal to or smaller than 0.050, and a ratio (Sdc/Sac) of an average area Sdc of a magnetic cluster of the magnetic tape in a DC demagnetization state and an average area Sac of a magnetic cluster thereof in an AC demagnetization state measured with a magnetic force microscope is 0.80 to 1.30.
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公开(公告)号:US20180286453A1
公开(公告)日:2018-10-04
申请号:US15920768
申请日:2018-03-14
Applicant: FUJIFILM Corporation
Inventor: Norihito KASADA , Eiki OZAWA
CPC classification number: G11B5/714 , G11B5/00813 , G11B5/3909 , G11B5/584 , G11B5/70 , G11B5/70615 , G11B5/71
Abstract: The magnetic tape device includes a magnetic tape including a magnetic layer, in which an intensity ratio of a peak intensity of a diffraction peak of a (110) plane with respect to a peak intensity of a diffraction peak of a (114) plane of a hexagonal ferrite crystal structure obtained by an X-ray diffraction analysis of the magnetic layer by using an In-Plane method is 0.5 to 4.0, a vertical direction squareness ratio of the magnetic tape is 0.65 to 1.00, Ra measured regarding a surface of the magnetic layer is equal to or smaller than 2.0 nm, and a C—H derived C concentration calculated from a C—H peak area ratio of C1s spectra obtained by X-ray photoelectron spectroscopic analysis performed on the surface of the magnetic layer at a photoelectron take-off angle of 10 degrees is 45 to 65 atom %.
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公开(公告)号:US20180286439A1
公开(公告)日:2018-10-04
申请号:US15920592
申请日:2018-03-14
Applicant: FUJIFILM Corporation
Inventor: Eiki OZAWA , Norihito KASADA
CPC classification number: G11B5/3909 , G11B5/00813 , G11B5/70 , G11B5/78 , G11B15/62
Abstract: The magnetic tape device includes a TMR head and a magnetic tape, in which the magnetic tape includes fatty acid ester in a magnetic layer, Ra measured regarding a surface of the magnetic layer is 2.0 nm or smaller, full widths at half maximum of spacing distribution measured by optical interferometry regarding a surface of the magnetic layer before and after performing a vacuum heating with respect to the magnetic tape are greater than 0 nm and 7.0 nm or smaller, a difference between spacings before and after the vacuum heating is greater than 0 nm and 8.0 nm or smaller, and a ratio of an average area Sdc of a magnetic cluster of the magnetic tape in a DC demagnetization state and an average area Sac of a magnetic cluster thereof in an AC demagnetization state measured with a magnetic force microscope is 0.80 to 1.30.
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公开(公告)号:US20180240477A1
公开(公告)日:2018-08-23
申请号:US15900412
申请日:2018-02-20
Applicant: FUJIFILM Corporation
Inventor: Norihito KASADA , Eiki OZAWA
CPC classification number: G11B5/702 , G11B5/3909 , G11B5/68 , G11B5/70 , G11B5/84
Abstract: The magnetic tape device includes a magnetic tape; and a servo head, in which the servo head is a TMR head, the magnetic tape includes a servo pattern in the magnetic layer, a center line average surface roughness Ra measured regarding a surface of the magnetic layer is equal to or smaller than 2.0 nm, a logarithmic decrement acquired by a pendulum viscoelasticity test performed regarding the surface of the magnetic layer is equal to or smaller than 0.050, and a ratio (Sdc/Sac) of an average area Sdc of a magnetic cluster of the magnetic tape in a DC demagnetization state and an average area Sac of a magnetic cluster thereof in an AC demagnetization state measured with a magnetic force microscope is 0.80 to 1.30.
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公开(公告)号:US20180182429A1
公开(公告)日:2018-06-28
申请号:US15854383
申请日:2017-12-26
Applicant: FUJIFILM Corporation
Inventor: Norihito KASADA , Eiki OZAWA , Tetsuya KANEKO
CPC classification number: G11B15/46 , G11B5/3909 , G11B5/70 , G11B5/706 , G11B5/73 , G11B5/78 , G11B5/842
Abstract: The magnetic tape device includes: a magnetic tape; and a reproducing head, in which a magnetic tape transportation speed of the magnetic tape device is equal to or lower than 18 m/sec, the reproducing head is a magnetic head including a tunnel magnetoresistance effect type element as a reproducing element, the magnetic tape includes a non-magnetic support, and a magnetic layer including ferromagnetic powder and a binding agent on the non-magnetic support, the magnetic layer includes one or more components selected from the group consisting of fatty acid and fatty acid amide, and a C—H derived C concentration calculated from a C—H peak area ratio of C1s spectra obtained by X-ray photoelectron spectroscopic analysis performed on the surface of the magnetic layer at a photoelectron take-off angle of 10 degrees is 45 to 65 atom %.
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