公开(公告)号：US20180286446A1

公开(公告)日：2018-10-04

申请号：US15920517

申请日：2018-03-14

Applicant: FUJIFILM Corporation

Inventor： Eiki OZAWA ,  Norihito KASADA

IPC: G11B5/712 ,  G11B5/39 ,  G11B5/008 ,  G11B5/706

CPC classification number: G11B5/712 ,  G11B5/00813 ,  G11B5/3909 ,  G11B5/584 ,  G11B5/70 ,  G11B5/70615 ,  G11B5/78

Abstract: The magnetic tape device includes a TMR head (servo head); and a magnetic tape including a magnetic layer including ferromagnetic hexagonal ferrite powder, a binding agent, and fatty acid ester, in which an XRD intensity ratio 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 is 0.65 to 1.00, Ra measured regarding a surface of the magnetic layer is equal to or smaller than 2.0 nm, 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 equal to or smaller than 7.0 nm, and a difference between spacings before and after the vacuum heating is greater than 0 nm and equal to or smaller than 8.0 nm.

公开(公告)号：US20180286442A1

公开(公告)日：2018-10-04

申请号：US15920515

申请日：2018-03-14

Applicant: FUJIFILM Corporation

Inventor： Eiki OZAWA ,  Norihito KASADA

IPC: G11B5/706 ,  G11B5/39 ,  G11B5/008

CPC classification number: G11B5/70615 ,  G11B5/00813 ,  G11B5/3909 ,  G11B5/70 ,  G11B5/78

Abstract: The magnetic tape device includes a TMR head (reproducing head); and a magnetic tape including a magnetic layer including ferromagnetic hexagonal ferrite powder, a binding agent, and fatty acid ester, in which an XRD intensity ratio 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 is 0.65 to 1.00, Ra measured regarding a surface of the magnetic layer is equal to or smaller than 2.0 nm, full widths at half maximum of spacing distribution measured by optical interferometry regarding the surface of the 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 7.0 nm, and a difference between spacings before and after the vacuum heating is greater than 0 nm and equal to or smaller than 8.0 nm.

公开(公告)号：US20180240491A1

公开(公告)日：2018-08-23

申请号：US15900160

申请日：2018-02-20

Applicant: FUJIFILM Corporation

Inventor： Eiki OZAWA ,  Norihito KASADA

IPC: G11B5/712 ,  G11B5/008

CPC classification number: G11B5/712 ,  G11B5/00813 ,  G11B5/70 ,  G11B5/71 ,  G11B5/78

Abstract: The magnetic tape has an Ra measured regarding a surface of the magnetic layer of equal to or smaller than 1.8 nm, a logarithmic decrement acquired by a pendulum viscoelasticity test performed regarding the surface of the magnetic layer of equal to or smaller than 0.050, the magnetic layer includes fatty acid ester, a full width at half maximum of spacing distribution measured by optical interferometry regarding the surface of the magnetic layer before and after performing vacuum heating with respect to the magnetic tape is respectively greater than 0 nm and equal to or smaller than 7.0 nm, and a difference between a spacing measured by optical interferometry regarding the surface of the magnetic layer after performing the vacuum heating with respect to the magnetic tape and a spacing measured before performing the vacuum heating is greater than 0 nm and equal to or smaller than 8.0 nm.

公开(公告)号：US20180240476A1

公开(公告)日：2018-08-23

申请号：US15900141

申请日：2018-02-20

Applicant: FUJIFILM Corporation

Inventor： Norihito KASADA ,  Eiki OZAWA

IPC: G11B5/008 ,  G11B5/706 ,  G11B5/02 ,  G11B5/708 ,  G11B5/596 ,  G11B5/39 ,  G11B5/70 ,  G11B5/73 ,  G11B5/845

CPC classification number: G11B5/00813 ,  G11B5/02 ,  G11B5/3903 ,  G11B5/3909 ,  G11B5/59683 ,  G11B5/70 ,  G11B5/7013 ,  G11B5/70678 ,  G11B5/708 ,  G11B5/7305 ,  G11B5/78 ,  G11B5/845

Abstract: The magnetic tape device includes a magnetic tape; and a reproducing head, in which the reproducing head is a TMR head, a center line average surface roughness Ra measured regarding a surface of the magnetic layer of the magnetic tape 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 of the magnetic tape in an AC demagnetization state measured with a magnetic force microscope is 0.80 to 1.30.

公开(公告)号：US20180182431A1

公开(公告)日：2018-06-28

申请号：US15854506

申请日：2017-12-26

Applicant: FUJIFILM Corporation

Inventor： Eiki OZAWA ,  Tetsuya KANEKO ,  Norihito KASADA

IPC: G11B15/675 ,  G11B5/39 ,  G11B5/708

CPC classification number: G11B15/67505 ,  G11B5/3909 ,  G11B5/584 ,  G11B5/70 ,  G11B5/708 ,  G11B5/71 ,  G11B5/725 ,  G11B5/74 ,  G11B5/84 ,  G11B5/8408

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 non-magnetic support, and a magnetic layer including ferromagnetic powder, a binding agent, and fatty acid ester on the non-magnetic support, the magnetic layer includes a servo pattern, 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 equal to or smaller than 7.0 nm, and a difference between a spacing measured by optical interferometry regarding the surface of the magnetic layer after performing the vacuum heating with respect to the magnetic tape and a spacing measured before performing the vacuum heating is greater than 0 nm and equal to or smaller than 9.0 nm.

公开(公告)号：US20180182430A1

公开(公告)日：2018-06-28

申请号：US15854439

申请日：2017-12-26

Applicant: FUJIFILM Corporation

Inventor： Eiki OZAWA ,  Tetsuya KANEKO ,  Norihito KASADA

IPC: G11B15/675 ,  G11B5/39 ,  G11B5/708

Abstract: The magnetic tape device includes: a magnetic tape; and a reproducing head, in which the reproducing head is a TMR head, the magnetic tape includes a non-magnetic support, and a magnetic layer including ferromagnetic powder, a binding agent, and fatty acid ester on the non-magnetic support, a full width at half maximum of spacing distribution measured by optical interferometry regarding a surface of the magnetic layer before performing a vacuum heating with respect to the magnetic tape is greater than 0 nm and equal to or smaller than 7.0 nm, a full width at half maximum of spacing distribution measured after performing the vacuum heating is greater than 0 nm and equal to or smaller than 7.0 nm, and a difference between a spacing measured by optical interferometry regarding the surface of the magnetic layer after performing the vacuum heating with respect to the magnetic tape and a spacing measured before performing the vacuum heating is greater than 0 nm and equal to or smaller than 9.0 nm.

公开(公告)号：US20180182428A1

公开(公告)日：2018-06-28

申请号：US15854409

申请日：2017-12-26

Applicant: FUJIFILM Corporation

Inventor： Norihito KASADA ,  Eiki OZAWA ,  Tetsuya KANEKO

IPC: G11B15/18 ,  G11B5/39 ,  G11B5/708

CPC classification number: G11B15/18 ,  G11B5/3909 ,  G11B5/70 ,  G11B5/708 ,  G11B5/78

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, and a coefficient of friction measured regarding a base portion of a surface of the magnetic layer is equal to or smaller than 0.30.

公开(公告)号：US20180182417A1

公开(公告)日：2018-06-28

申请号：US15854438

申请日：2017-12-26

Applicant: FUJIFILM Corporation

Inventor： Tetsuya KANEKO ,  Norihito KASADA ,  Eiki OZAWA

IPC: G11B5/39 ,  G11B5/66 ,  G11B5/55 ,  G11B5/592 ,  G11B5/596

CPC classification number: G11B5/3909 ,  G11B5/00826 ,  G11B5/5526 ,  G11B5/584 ,  G11B5/5926 ,  G11B5/59633 ,  G11B5/59688 ,  G11B5/66 ,  G11B5/70

Abstract: The magnetic tape device includes: a magnetic tape; and a servo head, in which a magnetic tape transportation speed of the magnetic tape device is equal to or lower than 18 m/sec, the servo head is a magnetic head including a tunnel magnetoresistance effect type element as a servo pattern reading 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 a servo pattern, and a coefficient of friction measured regarding a base portion of a surface of the magnetic layer is equal to or smaller than 0.30.

公开(公告)号：US20170372739A1

公开(公告)日：2017-12-28

申请号：US15624792

申请日：2017-06-16

Applicant: FUJIFILM Corporation

Inventor： Eiki OZAWA ,  Norihito KASADA ,  Takuto KUROKAWA

IPC: G11B5/78 ,  G11B5/71 ,  G11B5/712 ,  G11B5/73

CPC classification number: G11B5/78 ,  G11B5/00817 ,  G11B5/70 ,  G11B5/708 ,  G11B5/71 ,  G11B5/712 ,  G11B5/7305

Abstract: Provided is a magnetic tape with the total thickness of a non-magnetic and magnetic layers is equal to or smaller than 0.60 μm, a C—H derived C concentration calculated from a C—H peak area ratio of C1s spectra by ESCA on the surface of the magnetic layer at a photoelectron take-off angle of 10 degrees is equal to or greater than 45 atom %, full widths at half maximum of spacing distribution measured by optical interferometry regarding the surface of the magnetic layer before and after vacuum heating with respect to the magnetic tape are respectively greater than 0 nm and equal to or smaller than 7.0 nm, and a difference between a spacing measured after the vacuum heating and a spacing measured before the vacuum heating is greater than 0 nm and equal to or smaller than 8.0 nm.

公开(公告)号：US20170372726A1

公开(公告)日：2017-12-28

申请号：US15621464

申请日：2017-06-13

Applicant: FUJIFILM Corporation

Inventor： Norihito KASADA ,  Tetsuya KANEKO ,  Eiki OZAWA

IPC: G11B5/008 ,  G11B5/596 ,  G11B5/712

CPC classification number: G11B5/71 ,  G11B5/00813 ,  G11B5/584 ,  G11B5/59633 ,  G11B5/59688 ,  G11B5/70 ,  G11B5/712 ,  G11B5/78

Abstract: The magnetic tape includes a magnetic layer having ferromagnetic powder and a binder on a non-magnetic support, in which a total thickness of the magnetic tape is equal to or smaller than 5.30 μm, the magnetic layer includes a timing-based servo pattern, a center line average surface roughness Ra measured regarding a surface of the magnetic layer is equal to or smaller than 1.8 nm, one or more components selected from the group consisting of fatty acid and fatty acid amide are included in the magnetic layer, 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 equal to or greater than 45 atom %.