公开(公告)号：US20220172742A1

公开(公告)日：2022-06-02

申请号：US16651542

申请日：2019-10-02

申请人： Sony Corporation

发明人： Noboru SEKIGUCHI ,  Minoru YAMAGA

IPC分类号： G11B5/714 ,  G11B5/706 ,  G11B5/592 ,  G11B5/78

摘要： A magnetic recording medium is a tape-shaped magnetic recording medium, including: a substrate; an underlayer provided on the substrate; and a magnetic layer provided on the underlayer. The substrate contains polyester, each of the underlayer and the magnetic layer contains a lubricant, the magnetic layer has a surface on which a large number of holes is provided, the arithmetic average roughness Ra of the surface is 2.5 nm or less, a BET specific surface area of the entire magnetic recording medium measured in a state where the magnetic recording medium has been washed and dried is 3.5 m2/g or more and 7.0 m2/g or less, a squareness ratio of the magnetic layer in a vertical direction is 65% or more, an average thickness of the magnetic layer is 80 nm or less, an average thickness of the magnetic recording medium is 5.6 μm or less, and a servo pattern is recorded on the magnetic layer and a statistical value δSW indicating a non-linearity of the servo pattern is 24 nm or less.

公开(公告)号：US20210125634A1

公开(公告)日：2021-04-29

申请号：US16605469

申请日：2018-11-19

申请人： Sony Corporation

发明人： Minoru YAMAGA ,  Takanobu IWAMA ,  Jun TAKAHASHI

IPC分类号： G11B5/73 ,  G11B5/78

摘要： This technology aims to provide a magnetic recording tape and the like, which allow the tape to stably run at high speed while maintaining a state in which the distance between a magnetic head and the tape is held narrow.
This technology provides a magnetic recording tape having a plural-layer structure including at least a magnetic layer. The tape has a total thickness of 5.6 μm or smaller, and includes a plurality of indentations disposed in a surface of the magnetic layer. A value obtained by dividing a depth D1 of each indentation with a thickness D2 of the magnetic layer is 15% or greater. The magnetic layer is perpendicularly oriented, and has a perpendicular orientation of 65% or greater under condition of no demagnetization correction. The magnetic layer includes a plurality of indentations formed therein, a plurality of the indentations each has a depth of 20% or greater of the thickness of the magnetic layer, and the number of the indentations is 55 or more per 6,400 μm2 of a surface area of the magnetic layer. This technology also provides a manufacturing method of the magnetic recording tape.

公开(公告)号：US20210020196A1

公开(公告)日：2021-01-21

申请号：US17032718

申请日：2020-09-25

申请人： Sony Corporation

发明人： Noboru SEKIGUCHI ,  Minoru YAMAGA

IPC分类号： G11B5/62 ,  C23C14/00 ,  G11B5/735 ,  G11B5/733 ,  G11B5/706

摘要： The average thickness tT of a magnetic recording medium meets the requirement that tT≤5.5 [μm], and the dimensional change amount Δw in the width direction of the magnetic recording medium with respect to the tension change in the longitudinal direction of the magnetic recording medium meets the requirement that 700 ppm/N≤Δw.

公开(公告)号：US20210012805A1

公开(公告)日：2021-01-14

申请号：US16969876

申请日：2019-02-18

申请人： Sony Corporation

发明人： Masaru TERAKAWA ,  Minoru YAMAGA ,  Takanobu IWAMA ,  Jun TAKAHASHI

IPC分类号： G11B20/12 ,  G11B5/733 ,  G11B5/706 ,  G11B5/008

摘要： [Object] Provided is a technology that is capable of further improving a recording density of data.
[Solving Means] A magnetic recording medium according to the present technology is a magnetic recording medium in a shape of a tape that is long in a longitudinal direction and is short in a width direction, the medium including: a base material; a magnetic layer; and a non-magnetic layer that is provided between the base material and the magnetic layer, and contains one or more types of non-magnetic inorganic particles, in which the magnetic layer includes a data band long in the longitudinal direction in which a data signal is to be written, and a servo band long in the longitudinal direction in which a servo signal is written, and in the magnetic layer, a degree of vertical orientation is greater than or equal to 65%, a half width of a solitary waveform in a reproduction waveform of the servo signal is less than or equal to 195 nm, and a thickness of the magnetic layer is less than or equal to 90 nm, and the non-magnetic layer contains at least Fe-based non-magnetic particles as the non-magnetic inorganic particles, and in the non-magnetic layer, an average particle volume of the Fe-based non-magnetic particles is less than or equal to 2.0×10−5 μm3, and a thickness of the non-magnetic layer is less than or equal to 1.1 μm.

公开(公告)号：US20200342905A1

公开(公告)日：2020-10-29

申请号：US16703435

申请日：2019-12-04

申请人： SONY CORPORATION

发明人： Minoru YAMAGA ,  Noboru SEKIGUCHI ,  Tooru SATO ,  Takashi AIZAWA

IPC分类号： G11B5/73 ,  G11B5/78

摘要： A magnetic recording medium is provided and includes a magnetic layer, a non-magnetic layer, a base layer and a back layer, wherein an average thickness tT of the magnetic recording medium is tT≤5.3 μm, a dimensional change amount Δw in a width direction with respect to a change in tension in a longitudinal direction is 700 ppm/N≤Δw, a thickness of the non-magnetic layer is 2.0 μm or less, a squareness ratio measured in a vertical direction of the magnetic recording medium is 65% or more, and the magnetic layer includes a magnetic powder.

公开(公告)号：US20200342904A1

公开(公告)日：2020-10-29

申请号：US16510024

申请日：2019-07-12

申请人： SONY CORPORATION

发明人： Minoru YAMAGA ,  Noboru SEKIGUCHI ,  Tooru SATO ,  Takashi AIZAWA

IPC分类号： G11B5/73 ,  G11B5/78

摘要： There is provided a magnetic recording medium of which an average thickness tT is tT≤5.6 μ, a dimensional change amount Δw in a width direction with respect to a change in tension in a longitudinal direction is 660 ppm/N≤Δw, a squareness ratio in a vertical direction is 65% or more, and a width deformation coefficient b during long-term storage in a case where a long-term storage width change amount Y is defined as Y=blog(t) is −0.06 μm≤b≤0.06 μ.

公开(公告)号：US20200312364A1

公开(公告)日：2020-10-01

申请号：US16455188

申请日：2019-06-27

申请人： SONY CORPORATION

发明人： Masaru TERAKAWA ,  Minoru YAMAGA

IPC分类号： G11B5/73 ,  G11B5/733 ,  G11B5/65 ,  G11B5/667

摘要： A magnetic recording medium includes a layer structure including a magnetic layer, a non-magnetic layer, and a base layer in this order, in which an average thickness tT is tT≤5.5 μm, a dimensional variation Δw in a width direction to tension change in a longitudinal direction is 660 ppm/N≤Δw, and an average thickness tn of the non-magnetic layer is tn≤1.0 μm.

公开(公告)号：US20230274764A1

公开(公告)日：2023-08-31

申请号：US18123510

申请日：2023-03-20

申请人： Sony Corporation

发明人： Minoru YAMAGA ,  Futoshi SASAKI

IPC分类号： G11B5/706 ,  G11B5/73 ,  G11B5/735 ,  G11B5/592 ,  G11B5/71 ,  G11B5/714

CPC分类号： G11B5/70678 ,  G11B5/73927 ,  G11B5/7358 ,  G11B5/5928 ,  G11B5/71 ,  G11B5/714

摘要： A magnetic recording medium is a magnetic recording medium in the form of a tape and includes a substrate, a foundation layer provided on the substrate, and a magnetic layer provided on the foundation layer and containing a magnetic powder. The foundation layer and the magnetic layer each contain a lubricant. A squareness ratio of the magnetic layer in a perpendicular direction is equal to or higher than 65%, an average thickness of the magnetic recording medium is equal to or smaller than 5.6 μm, a plurality of recessed portions each having a depth corresponding to 20% or higher of the average thickness of the magnetic layer is provided on a surface of the magnetic layer, and the number of the recessed portions per unit area of 1,600 μm2 of the surface of the magnetic layer is equal to or greater than 20 and equal to or smaller than 200, and an amount of exudation of the lubricant per unit region of 12.5 μm×9.3 μm on the surface of the magnetic layer in a vacuum is equal to or greater than 3.0 μm2 and equal to or smaller than 6.5 μm2.

公开(公告)号：US20220270643A1

公开(公告)日：2022-08-25

申请号：US17259072

申请日：2020-10-08

申请人： Sony Corporation

发明人： Minoru YAMAGA ,  Tooru SATO ,  Kanako HASHIMOTO

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

摘要： It is an object of the present technology to provide a magnetic recording medium having a small total thickness, which can be reproduced satisfactorily after long-term storage.
The present technology provides a tape-shaped magnetic recording medium including a magnetic layer, an underlayer, a base layer, and a back layer. The magnetic recording medium has an average thickness tT of 5.4 μm or less, when a thermomechanical analysis is performed on the magnetic recording medium in a temperature range of 40° C. to 150° C. at a temperature rise rate of 1° C./minute, a switching temperature for switching from thermal expansion to thermal contraction is 70° C. or more, and a contraction start temperature is 90° C. or more at which a length in a longitudinal direction is shorter than the length at 40° C., and a Poisson's ratio is 0.40 or less.

公开(公告)号：US20210350827A1

公开(公告)日：2021-11-11

申请号：US17272159

申请日：2019-09-05

申请人： Sony Corporation

发明人： Masaru TERAKAWA ,  Minoru YAMAGA

IPC分类号： G11B5/706

摘要： A magnetic recording medium used on a record/playback device with a minimum recording wavelength or 50 nm or shorter, the magnetic recording medium including a magnetic layer that contains a spinel-type ferrite magnetic powder, the magnetic layer having an average thickness of 85 nm or smaller, and the magnetic layer having a saturation flux density of 1600 Gauss or larger and 2000 Gauss or smaller.