Magnetic tape, magnetic tape cartridge, and magnetic tape apparatus

Patent metadata

Field	Value
Publication number	US-2020251135-A1
Application number	US-202016777411-A
Country	US
Kind code	A1
Filing date	Jan 30, 2020
Priority date	Jan 31, 2019
Publication date	Aug 6, 2020
Grant date	—

Abstract

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.

First claim

What is claimed is:

1 . A magnetic tape comprising:
a non-magnetic support; and a magnetic layer including ferromagnetic powder and a binding agent, wherein the magnetic layer has a timing-based servo pattern, wherein an edge shape of the timing-based servo pattern, specified by magnetic force microscopy is a shape in which a difference L 99.9 −L 0.1 between a value L 99.9 of a cumulative distribution function of 99.9% and a value L 0.1 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 wherein 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.

2 . The magnetic tape according to claim 1 ,
wherein a difference Nxy−Nz between the refractive index Nxy and the refractive index Nz is 0.25 or more and 0.40 or less.

3 . The magnetic tape according to claim 1 ,
wherein the timing-based servo pattern is a linear servo pattern which continuously extends from one side of the magnetic tape in a width direction to the other side thereof and is inclined at an angle α with respect to the width direction, and wherein the ideal shape is a linear shape extending in a direction of the angle α.

4 . The magnetic tape according to claim 1 ,
wherein the difference L 99.9 −L 0.1 is 100 nm or more and 180 nm or less.

5 . The magnetic tape according to claim 1 , further comprising:
a non-magnetic layer including non-magnetic powder and a binding agent between the non-magnetic support and the magnetic layer.

6 . The magnetic tape according to claim 1 , further comprising:
a back coating layer including non-magnetic powder and a binding agent on a surface side of the non-magnetic support opposite to a surface side provided with the magnetic layer.

7 . A magnetic tape cartridge comprising the magnetic tape according to claim 1 .

8 . The magnetic tape cartridge according to claim 7 ,
wherein a difference Nxy−Nz between the refractive index Nxy and the refractive index Nz is 0.25 or more and 0.40 or less.

9 . The magnetic tape cartridge according to claim 7 ,
wherein the timing-based servo pattern is a linear servo pattern which continuously extends from one side of the magnetic tape in a width direction to the other side thereof and is inclined at an angle α with respect to the width direction, and wherein the ideal shape is a linear shape extending in a direction of the angle α.

10 . The magnetic tape cartridge according to claim 7 ,
wherein the difference L 99.9 −L 0.1 is 100 nm or more and 180 nm or less.

11 . The magnetic tape cartridge according to claim 7 ,
wherein the magnetic tape further comprises a non-magnetic layer including non-magnetic powder and a binding agent between the non-magnetic support and the magnetic layer.

12 . The magnetic tape cartridge according to claim 7 ,
wherein the magnetic tape further comprises a a back coating layer including non-magnetic powder and a binding agent on a surface side of the non-magnetic support opposite to a surface side provided with the magnetic layer.

13 . A magnetic tape apparatus comprising:
a magnetic tape; a reading element unit; and an extraction unit, wherein the magnetic tape is the magnetic tape according to claim 1 , wherein the reading element unit includes a plurality of reading elements each of which reads data from a specific track region including a reading target track in a track region included in the magnetic tape, and wherein the extraction unit performs a waveform equalization process with respect to each reading result for each reading element, to extract, from the reading result, data derived from the reading target track.

14 . The magnetic tape apparatus according to claim 13 ,
wherein a difference Nxy−Nz between the refractive index Nxy and the refractive index Nz is 0.25 or more and 0.40 or less.

15 . The magnetic tape apparatus according to claim 13 ,
wherein the timing-based servo pattern is a linear servo pattern which continuously extends from one side of the magnetic tape in a width direction to the other side thereof and is inclined at an angle α with respect to the width direction, and wherein the ideal shape is a linear shape extending in a direction of the angle α.

16 . The magnetic tape apparatus according to claim 13 ,
wherein the difference L 99.9 −L 0.1 is 100 nm or more and 180 nm or less.

17 . The magnetic tape apparatus according to claim 13 ,
wherein the magnetic tape further comprises a non-magnetic layer including non-magnetic powder and a binding agent between the non-magnetic support and the magnetic layer.

18 . The magnetic tape apparatus according to claim 13 ,
wherein the magnetic tape further comprises a a back coating layer including non-magnetic powder and a binding agent on a surface side of the non-magnetic support opposite to a surface side provided with the magnetic layer.

Assignees

• Fujifilm Corp

Inventors

• Kasada Norihito
• Ozawa Eiki
• Musha Atsushi

Classifications

• H01F1/113

  in a bonding agent · CPC title

• B82Y25/00

  Nanomagnetism, e.g. magnetoimpedance, anisotropic magnetoresistance, giant magnetoresistance or tunneling magnetoresistance · CPC title

• G11B5/733

  characterised by the addition of non-magnetic particles {(base layers having a non-magnetic layer under a soft magnetic layer G11B5/736; magnetic recording media substrates G11B5/739)} · CPC title

• G11B5/70678

  Ferrites · CPC title

• G11B5/7356

  comprising non-magnetic particles in the back layer, e.g. particles of TiO2, ZnO or SiO2 · CPC title