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.

公开(公告)号：US11302355B2

公开(公告)日：2022-04-12

申请号：US17156136

申请日：2021-01-22

申请人： Sony Corporation

发明人： Minoru Yamaga ,  Noboru Sekiguchi

IPC分类号： G11B5/66 ,  G11B23/03 ,  G11B5/706 ,  G11B5/133 ,  G11B5/596 ,  G11B5/714 ,  G11B5/73 ,  G11B5/735 ,  G11B15/06 ,  G11B5/702 ,  G11B5/733 ,  G11B5/78

摘要： A magnetic recording medium is provided and includes a substrate; and a magnetic layer provided over the substrate, wherein (wmax−wmin)/wmin≤400 [ppm] . . . (1) where wmax and wmin are respectively maximum and minimum of average values of width corresponding to samples of magnetic recording medium measured after the samples are stored for two hours under storage conditions (a loading tension in the longitudinal direction of the magnetic recording medium, a temperature and a relative humidity) for each of the samples, and a width of a sample of the magnetic recording medium at 25° C. and 50% relative humidity and without loading is ½ inch, magnetic recording medium has Young's modulus of less than 8.0 GPa in a longitudinal direction, and 4.0≤TB/(TA−TB) . . . (2) where TA is average thickness of magnetic recording medium and TB is average thickness of substrate.

公开(公告)号：US11250880B2

公开(公告)日：2022-02-15

申请号：US16627600

申请日：2018-04-13

申请人： Sony Corporation

发明人： Toshiaki Miura ,  Satoru Abe ,  Yuuko Kamoshita ,  Riku Yoshida

IPC分类号： G11B5/702 ,  G11B5/706 ,  G11B5/68 ,  G11B5/733 ,  G11B5/73

摘要： A magnetic recording medium includes: a substrate that is long in shape; and a magnetic layer containing magnetic powder and a binder. The glass transition point of the binder is not lower than 75° C. In a case where atomic force microscope observation images in a 10 μm×10 μm rectangular shape are acquired at five locations randomly selected from the surface on the side of the magnetic layer, any linear protrusion that is 3 nm to 20 nm in height, is 0.3 μm to 1.0 μm in width, and extends across two sides of the observation image does not exist in the observation images of four locations among the acquired observation images of the five locations.

公开(公告)号：US20220036918A1

公开(公告)日：2022-02-03

申请号：US17500337

申请日：2021-10-13

申请人： FUJIFILM Corporation

发明人： Norihito KASADA

IPC分类号： G11B5/702 ,  G11B5/706

摘要： The magnetic recording medium includes a non-magnetic support; and a magnetic layer including ferromagnetic powder and a binding agent on the non-magnetic support, in which an isoelectric point of a surface zeta potential of the magnetic layer is equal to or greater than 5.5.