Head positioning of timing-based servo system for magnetic tape recording device

Patent metadata

Field	Value
Publication number	US-10366721-B2
Application number	US-201816009603-A
Country	US
Kind code	B2
Filing date	Jun 15, 2018
Priority date	Jun 23, 2017
Publication date	Jul 30, 2019
Grant date	Jul 30, 2019

Abstract

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 includes a timing-based servo pattern, the ferromagnetic powder is ferromagnetic hexagonal ferrite powder having an activation volume equal to or smaller than 1,600 nm 3 , an XRD intensity ratio Int(110)/Int(114) 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 of the magnetic tape is 0.65 to 1.00, and an edge shape of the timing-based servo pattern specified by magnetic force microscope observation is a shape in which a difference (L 99.9 −L 0.1 ) is equal to or smaller than 180 nm, and a magnetic tape device including the magnetic tape.

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 on the non-magnetic support,
wherein the magnetic layer includes a timing-based servo pattern,
the ferromagnetic powder is ferromagnetic hexagonal ferrite powder having an activation volume equal to or smaller than 1,600 nm 3 ,
an intensity ratio Int(110)/Int(114) of a peak intensity Int(110) of a diffraction peak of a (110) plane with respect to a peak intensity Int(114) of a diffraction peak of a (114) plane of a hexagonal ferrite crystal structure 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 of the magnetic tape is 0.65 to 1.00, and
an edge shape of the timing-based servo pattern specified by magnetic force microscope observation is a shape in which a difference (L 99.9 −L 0.1 ) of a value L 99.9 of a cumulative distribution function of 99.9% of a position shift width from an ideal shape in a longitudinal direction of the magnetic tape and a value L 0.1 of the cumulative distribution function of 0.1% is equal to or smaller than 180 nm.

2. The magnetic tape according to claim 1 ,
wherein the timing-based servo pattern is a linear servo pattern which continuously or discontinuously extends from one side to the other side in a width direction of the magnetic tape.

3. The magnetic tape according to claim 2 ,
wherein the timing-based servo pattern is a linear servo pattern which continuously extends from one side to the other side in the width direction of the magnetic tape and which is tilted with respect to the width direction by an angle of α, and
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 vertical direction squareness ratio of the magnetic tape is 0.65 to 0.90.

5. The magnetic tape according to claim 1 ,
wherein the difference (L 99.9 −L 0.1 ) is equal to or smaller than 150 nm.

6. The magnetic tape according to claim 1 ,
wherein the activation volume of the ferromagnetic hexagonal ferrite powder is 800 nm 3 to 1,600 nm 3 .

7. 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.

8. A magnetic tape device comprising:
a magnetic tape;
a magnetic head; and
a servo head,
wherein the magnetic tape is a magnetic tape comprising:
a non-magnetic support; and
a magnetic layer including ferromagnetic powder and a binding agent on the non-magnetic support,
wherein the magnetic layer includes a timing-based servo pattern,
the ferromagnetic powder is ferromagnetic hexagonal ferrite powder having an activation volume equal to or smaller than 1,600 nm 3 ,
an intensity ratio Int(110)/Int(114) of a peak intensity Int(110) of a diffraction peak of a (110) plane with respect to a peak intensity Int(114) of a diffraction peak of a (114) plane of a hexagonal ferrite crystal structure 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 of the magnetic tape is 0.65 to 1.00, and
an edge shape of the timing-based servo pattern specified by magnetic force microscope observation is a shape in which a difference (L 99.9 −L 0.1 ) of a value L 99.9 of a cumulative distribution function of 99.9% of a position shift width from an ideal shape in a longitudinal direction of the magnetic tape and a value.

9. The magnetic tape device according to claim 8 ,
wherein the timing-based servo pattern is a linear servo pattern which continuously or discontinuously extends from one side to the other side in a width direction of the magnetic tape.

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

11. The magnetic tape device according to claim 8 ,
wherein the vertical direction squareness ratio of the magnetic tape is 0.65 to 0.90.

12. The magnetic tape device according to claim 8 ,
wherein the difference (L 99.9 −L 0.1 ) is equal to or smaller than 150 nm.

13. The magnetic tape device according to claim 8 ,
wherein the activation volume of the ferromagnetic hexagonal ferrite powder is 800 nm 3 to 1,600 nm 3 .

14. The magnetic tape device according to claim 8 ,
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.

Assignees

• Fujifilm Corp

Inventors

• Kasada Norihito

Classifications

• G11B5/584

  for track following on tapes · CPC title

• G11B5/00813

  magnetic tapes · CPC title

• G11B5/70678

  Ferrites · CPC title

• G11B5/3909

  Arrangements using a magnetic tunnel junction · CPC title

• G11B5/00817

  on longitudinal tracks only, e.g. for serpentine format recording · CPC title