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

Patent metadata

Field	Value
Publication number	US-10490220-B2
Application number	US-201816160377-A
Country	US
Kind code	B2
Filing date	Oct 15, 2018
Priority date	Mar 29, 2017
Publication date	Nov 26, 2019
Grant date	Nov 26, 2019

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 (=SFD 25°C. −SFD −190° C. ) in a longitudinal direction of the magnetic tape is equal to or smaller than 0.50, with the SFD 25° 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 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,
Δ SFD=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 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,
Δ SFD=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 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 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 magnetic tape includes a non-magnetic layer including non-magnetic powder and a binding agent between the non-magnetic support and the magnetic layer.

7. 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 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,
Δ SFD=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.

8. The magnetic reproducing method according to claim 7 ,
wherein the ΔSFD is 0.03 to 0.50.

9. 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 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.

10. The magnetic reproducing method according to claim 7 ,
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.

11. 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 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 magneto

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

• G11B5/584 Primary

  for track following on tapes · CPC title