MAGNETIC TAPE DEVICE AND HEAD TRACKING SERVO METHOD

• US 20180286453A1
• Filed: 03/14/2018
• Published: 10/04/2018
• Est. Priority Date: 03/29/2017
• Status: Active Grant

• Current Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Original Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Inventors: KASADA, Norihito, OZAWA, Eiki
• Granted Patent: US 10,373,639 B2
• Time in Patent Office: Days
• CPC Class Codes: G11B 5/00813 magnetic tapes
• CPC Class Codes: G11B 5/3909 Arrangements using a magnetic tunnel junction
• CPC Class Codes: G11B 5/584 for track following on tapes
• CPC Class Codes: G11B 5/70 on a base layer
• CPC Class Codes: G11B 5/70615 containing Fe metal or alloys G11B5/70621 takes precedence
• CPC Class Codes: G11B 5/71 characterised by the lubricant
• CPC Class Codes: G11B 5/714 characterised by the dimension of the magnetic particles

Abstract

The magnetic tape device includes a magnetic tape including a magnetic layer, in which an intensity ratio of a peak intensity of a diffraction peak of a (110) plane with respect to a peak intensity 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, Ra measured regarding a surface of the magnetic layer is equal to or smaller than 2.0 nm, and a C—H derived C concentration calculated from a C—H peak area ratio of C1s spectra obtained by X-ray photoelectron spectroscopic analysis performed on the surface of the magnetic layer at a photoelectron take-off angle of 10 degrees is 45 to 65 atom %.

Claims

1. A magnetic tape device comprising:

a magnetic tape; and

a servo head,

wherein the servo head is a magnetic head including a tunnel magnetoresistance effect type element as a servo pattern reading element,

the magnetic tape includes a non-magnetic support, and a magnetic layer including ferromagnetic powder and a binding agent on the non-magnetic support,

the magnetic layer includes a servo pattern,

the ferromagnetic powder is ferromagnetic hexagonal ferrite powder,

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,

a center line average surface roughness Ra measured regarding a surface of the magnetic layer is equal to or smaller than 2.0 nm,

the magnetic layer includes one or more components selected from the group consisting of fatty acid and fatty acid amide, and

a C—

H derived C concentration calculated from a C—

H peak area ratio of C1s spectra obtained by X-ray photoelectron spectroscopic analysis performed on the surface of the magnetic layer at a photoelectron take-off angle of 10 degrees is 45 to 65 atom %.

2. The magnetic tape device according to claim 1,

wherein the center line average surface roughness Ra measured regarding the surface of the magnetic layer is 1.2 nm to 2.0 nm.

3. The magnetic tape device according to claim 1,

Wherein the vertical direction squareness ratio of the magnetic tape is 0.65 to 0.90.

4. The magnetic tape device according to claim 1,

wherein the magnetic tape includes a non-magnetic layer including non-magnetic powder and a binding agent between the non-magnetic support and the magnetic layer.

5. A head tracking servo method comprising:

reading a servo pattern of a magnetic layer of a magnetic tape by a servo head in a magnetic tape device,

wherein the servo head is a magnetic head including a tunnel magnetoresistance effect type element as a servo pattern reading element,

the magnetic tape includes a non-magnetic support, and a magnetic layer including ferromagnetic powder and a binding agent on the non-magnetic support,

the magnetic layer includes the servo pattern,

the ferromagnetic powder is ferromagnetic hexagonal ferrite powder,

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,

a center line average surface roughness Ra measured regarding a surface of the magnetic layer is equal to or smaller than 2.0 nm,

the magnetic layer includes one or more components selected from the group consisting of fatty acid and fatty acid amide, and

a C—

H derived C concentration calculated from a C—

H peak area ratio of C1s spectra obtained by X-ray photoelectron spectroscopic analysis performed on the surface of the magnetic layer at a photoelectron take-off angle of 10 degrees is 45 to 65 atom %.

6. The head tracking servo method according to claim 5,

wherein the center line average surface roughness Ra measured regarding the surface of the magnetic layer is 1.2 nm to 2.0 nm.

7. The head tracking servo method according to claim 5,

wherein the vertical direction squareness ratio of the magnetic tape is 0.65 to 0.90.

8. The head tracking servo method according to claim 5,

wherein the magnetic tape includes a non-magnetic layer including non-magnetic powder and a binding agent between the non-magnetic support and the magnetic layer.