公开(公告)号：US20240119963A1

公开(公告)日：2024-04-11

申请号：US18466600

申请日：2023-09-13

申请人： FUJIFILM Corporation

发明人： Norihito KASADA

IPC分类号： G11B5/584 ,  G11B5/702 ,  G11B5/706 ,  G11B5/714 ,  G11B5/78 ,  G11B15/43

CPC分类号： G11B5/584 ,  G11B5/7021 ,  G11B5/70678 ,  G11B5/714 ,  G11B5/78 ,  G11B15/43

摘要： The magnetic tape includes: a non-magnetic support; and a magnetic layer containing a ferromagnetic powder, in which the number of recesses existing on a surface of the magnetic layer and having an equivalent circle diameter of 0.25 μm or more and 0.55 μm or less is 10 or more and 500 or less per an area of 40 μm×40 μm, and standard deviation a of the number of the recesses in a width direction of the surface of the magnetic layer is 50 or less.

公开(公告)号：US20240096367A1

公开(公告)日：2024-03-21

申请号：US18498739

申请日：2023-10-31

申请人： FUJIFILM Corporation

发明人： Norihito KASADA

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

CPC分类号： G11B5/71 ,  G11B5/7028 ,  G11B5/7085 ,  G11B5/7356

摘要： 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：US11869559B2

公开(公告)日：2024-01-09

申请号：US17873728

申请日：2022-07-26

申请人： FUJIFILM Corporation

发明人： Noriko Oyanagi ,  Wataru Kikuchi ,  Akio Tamura

IPC分类号： G11B5/78 ,  G11B5/714 ,  G11B5/706 ,  G11B5/725 ,  G11B5/702 ,  G11B5/71 ,  G11B5/733

CPC分类号： G11B5/78 ,  G11B5/7028 ,  G11B5/70678 ,  G11B5/71 ,  G11B5/714 ,  G11B5/7253 ,  G11B5/7334

摘要： The magnetic tape includes a non-magnetic support, and a magnetic layer including a ferromagnetic powder. A fluorine-containing compound is included in a portion on the non-magnetic support on a magnetic layer side, and a ratio θr of a water contact angle measured on a surface of the magnetic layer after sliding on a magnetic head to a water contact angle measured on the surface of the magnetic layer before sliding on the magnetic head is 0.70 or more.

公开(公告)号：US11514943B2

公开(公告)日：2022-11-29

申请号：US16361797

申请日：2019-03-22

申请人： FUJIFILM Corporation

发明人： Norihito Kasada

IPC分类号： G11B5/78 ,  G11B5/735 ,  G11B5/702 ,  G11B5/008 ,  G11B5/706

摘要： The magnetic tape includes a non-magnetic support; a non-magnetic layer including a non-magnetic powder and a binding agent on the non-magnetic support; and a magnetic layer including a ferromagnetic powder and a binding agent on the non-magnetic layer, in which a total thickness of the non-magnetic layer and the magnetic layer is equal to or smaller than 0.60 μm, the magnetic layer has a servo pattern, and 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：US11482249B2

公开(公告)日：2022-10-25

申请号：US17130857

申请日：2020-12-22

申请人： FUJIFILM Corporation

发明人： Norihito Kasada ,  Yuto Murata ,  Yusuke Kaneko

IPC分类号： G11B5/706 ,  G11B5/008 ,  G11B15/43 ,  G11B20/12 ,  G11B5/702 ,  G11B5/592 ,  G11B5/735

摘要： A magnetic tape in which a minimum value of TDStens among five TDStens measured respectively at a temperature of 16° C. and a relative humidity of 20%, a temperature of 16° C. and a relative humidity of 80%, a temperature of 26° C. and a relative humidity of 80%, a temperature of 32° C. and a relative humidity of 20% and a temperature of 32° C. and a relative humidity of 55% is 1.43 μm/N or more, a ratio of a change of TDStens to a change of a relative humidity obtained from the five TDStens is 0.005 μm/N/% or less, and a ratio of a change of TDStens to a change of a temperature obtained from the five TDStens is 0.020 μm/N/° C. or less.

公开(公告)号：US11437063B2

公开(公告)日：2022-09-06

申请号：US16777411

申请日：2020-01-30

申请人： FUJIFILM Corporation

发明人： Norihito Kasada ,  Eiki Ozawa ,  Atsushi Musha

IPC分类号： G11B5/58 ,  G11B5/584 ,  G11B5/706 ,  G11B5/70 ,  G11B5/702 ,  G11B5/708 ,  G11B5/78 ,  G11B20/10 ,  G11B27/022 ,  B82Y10/00 ,  B82Y25/00 ,  G11B5/00

摘要： 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 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 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 or more and 0.40 or less.

公开(公告)号：US11430475B2

公开(公告)日：2022-08-30

申请号：US17032621

申请日：2020-09-25

申请人： FUJIFILM Corporation

发明人： Norihito Kasada

IPC分类号： G11B5/584 ,  G11B5/627 ,  G11B5/008 ,  G11B5/55 ,  G11B5/70 ,  G11B5/706 ,  G11B5/702 ,  G11B5/78 ,  G11B5/73 ,  G11B5/735 ,  G11B5/708

摘要： The magnetic tape includes a non-magnetic support; and a magnetic layer including ferromagnetic powder and a binding agent on the non-magnetic support, in which the magnetic layer has a servo pattern, and an absolute value ΔN of a difference between a refractive index Nxy measured regarding an in-plane direction of the magnetic layer and a refractive index Nz measured regarding a thickness direction of the magnetic layer is 0.25 to 0.40, a magnetic tape cartridge and a magnetic tape apparatus including this magnetic tape.

公开(公告)号：US11386926B2

公开(公告)日：2022-07-12

申请号：US16777411

申请日：2020-01-30

申请人： FUJIFILM Corporation

发明人： Norihito Kasada ,  Eiki Ozawa ,  Atsushi Musha

IPC分类号： G11B5/58 ,  G11B5/584 ,  G11B5/706 ,  G11B5/70 ,  G11B5/702 ,  G11B5/708 ,  G11B5/78 ,  G11B20/10 ,  G11B27/022 ,  B82Y10/00 ,  B82Y25/00 ,  G11B5/00

摘要： 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 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 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 or more and 0.40 or less.

公开(公告)号：US11367461B2

公开(公告)日：2022-06-21

申请号：US16857502

申请日：2020-04-24

申请人： FUJIFILM Corporation

发明人： Norihito Kasada

IPC分类号： G11B5/733 ,  G11B5/735 ,  G11B5/78 ,  G11B5/706 ,  G01B11/30 ,  G01B9/02 ,  G11B5/73 ,  G11B5/702

摘要： The magnetic recording medium includes: a non-magnetic support; and a magnetic layer including ferromagnetic powder, in which a difference Safter−Sbefore between a spacing Safter measured on a surface of the magnetic layer by optical interferometry after methyl-ethyl-ketone cleaning and a spacing Sbefore measured on the surface of the magnetic layer by optical interferometry before methyl-ethyl-ketone cleaning is more than 0 nm and 15.0 nm or less, and the non-magnetic support is an aromatic polyamide support having a moisture absorption of 2.2% or less.

公开(公告)号：US11355142B2

公开(公告)日：2022-06-07

申请号：US16777418

申请日：2020-01-30

申请人： FUJIFILM Corporation

发明人： Eiki Ozawa ,  Norihito Kasada ,  Atsushi Musha

IPC分类号： G11B5/584 ,  G01B11/06 ,  G11B5/708 ,  G11B5/70 ,  G11B5/702 ,  G11B5/706 ,  G11B5/78 ,  G11B20/10 ,  G11B23/50 ,  G11B27/022 ,  G11B5/00 ,  B82Y10/00 ,  B82Y25/00

摘要： 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 Safter measured on a surface of the magnetic layer by an optical interferometry after methyl-ethyl-ketone cleaning and a spacing Sbefore measured on the surface of the magnetic layer by an optical interferometry before methyl-ethyl-ketone cleaning is greater than 0 nm and 15.0 nm or less.