Magnetic tape device, magnetic reproducing method, and head tracking servo method

Patent metadata

Field	Value
Publication number	US-10134433-B2
Application number	US-201815920782-A
Country	US
Kind code	B2
Filing date	Mar 14, 2018
Priority date	Mar 29, 2017
Publication date	Nov 20, 2018
Grant date	Nov 20, 2018

Abstract

Provided is a magnetic tape device in which a magnetic tape transportation speed is equal to or lower than 18 m/sec, Ra measured regarding a surface of a magnetic layer of a magnetic tape is equal to or smaller than 2.0 nm, 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 %, and ΔSFD (=SFD25° C.−SFD−190° C.) in a longitudinal direction of the magnetic tape is equal to or smaller than 0.50, with the SFD25° C. being SFD measured in a longitudinal direction of the magnetic tape at a temperature of 25° C., and the SFD−190° C. being SFD measured at a temperature of −190° C.

First claim

What is claimed is:

1. A magnetic tape device comprising:
a magnetic tape; and
a reproducing head,
wherein a magnetic tape transportation speed of the magnetic tape device is equal to or lower than 18 m/sec,
the reproducing head is a magnetic head including a tunnel magnetoresistance effect type element as a reproducing 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,
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,
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 %, and
ΔSFD in a longitudinal direction of the magnetic tape calculated by Expression 1 is equal to or smaller than 0.50,
ΔSFD=SFD 25° C. −SFD −190° C.   Expression 1

in Expression 1, the SFD 25° C. is a switching field distribution SFD measured in a longitudinal direction of the magnetic tape at a temperature of 25° C., and the SFD −190° C. is a switching field distribution SFD measured in a longitudinal direction of the magnetic tape at a temperature of −190° C.

2. A magnetic tape device comprising:
a magnetic tape; and
a servo head,
wherein a magnetic tape transportation speed of the magnetic tape device is equal to or lower than 18 m/sec,
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,
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,
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 %, and
ΔSFD in a longitudinal direction of the magnetic tape calculated by Expression 1 is equal to or smaller than 0.50,
ΔSFD=SFD 25° C. −SFD −190° C.   Expression 1

in Expression 1, the SFD 25° C. is a switching field distribution SFD measured in a longitudinal direction of the magnetic tape at a temperature of 25° C., and the SFD −190° C. is a switching field distribution SFD measured in a longitudinal direction of the magnetic tape at a temperature of −190° C.

3. The magnetic tape device according to claim 1 ,
wherein the ΔSFD is 0.03 to 0.50.

4. A magnetic tape device comprising:
a magnetic tape; and
a reproducing head,
wherein a magnetic tape transportation speed of the magnetic tape device is equal to or lower than 18 m/sec,
the reproducing head is a magnetic head including a tunnel magnetoresistance effect type element as a reproducing 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,
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,
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 %, and
a ratio Sdc/Sac of an average area Sdc of a magnetic cluster of the magnetic tape in a DC demagnetization state and an average area Sac of a magnetic cluster of the magnetic tape in an AC demagnetization state measured with a magnetic force microscope is 0.80 to 1.30.

5. A magnetic tape device comprising:
a magnetic tape; and
a servo head,
wherein a magnetic tape transportation speed of the magnetic tape device is equal to or lower than 18 m/sec,
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,
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,
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 %, and
a ratio Sdc/Sac of an average area Sdc of a magnetic cluster of the magnetic tape in a DC demagnetization state and an average area Sac of a magnetic cluster of the magnetic tape in an AC demagnetization state measured with a magnetic force microscope is 0.80 to 1.30.

6. 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.

7. 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.

8. A magnetic reproducing method comprising:
reproducing information recorded on a magnetic tape by a reproducing head,
wherein a magnetic tape transportation speed during the reproducing is equal to or lower than 18 m/sec,
the reproducing head is a magnetic head including a tunnel magnetoresistance effect type element as a reproducing 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,
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,
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 %, and
ΔSFD in a longitudinal direction of the magnetic tape calculated by Expression 1 is equal to or smaller than 0.50,
ΔSFD=SFD 25° C. −SFD −190° C.   Expression 1

in Expression 1, the SFD 25° C. is a switching field distribution SFD measured in a longitudinal direction of the magnetic tape at a temperature of 25° C., and the SFD −190° C. is a switching field distribution SFD measured in a longitudinal direction of the magnetic tape at a temperature of −190° C.

9. The magnetic reproducing method according to claim 8 ,
wherein the ΔSFD is 0.03 to 0.50.

10. A magnetic reproducing method comprising:
reproducing information recorded on a magnetic tape by a reproducing head,
wherein a magnetic tape transportation speed

Assignees

• Fujifilm Corp

Inventors

• Kasada Norihito
• Ozawa Eiki

Classifications

• G11B5/78

  Tape carriers · CPC title

• G11B5/71

  characterised by the lubricant · CPC title

• G11B5/70

  on a base layer · CPC title

• G11B5/00817

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

• G11B5/70626 Primary

  containing non-metallic substances · CPC title