MAGNETIC TAPE DEVICE AND MAGNETIC REPRODUCING METHOD

• US 20180182430A1
• Filed: 12/26/2017
• Published: 06/28/2018
• Est. Priority Date: 12/27/2016
• Status: Active Grant

• Current Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Original Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Inventors: OZAWA, Eiki, KANEKO, Tetsuya, KASADA, Norihito
• Granted Patent: US 10,482,915 B2
• Time in Patent Office: Days
• CPC Class Codes: G11B 15/67505 Servo control
• CPC Class Codes: G11B 5/3909 Arrangements using a magnetic tunnel junction
• CPC Class Codes: G11B 5/70 on a base layer
• CPC Class Codes: G11B 5/708 characterised by addition of non-magnetic particles to the layer
• CPC Class Codes: G11B 5/78 Tape carriers

Abstract

The magnetic tape device includes: a magnetic tape; and a reproducing head, in which the reproducing head is a TMR head, the magnetic tape includes a non-magnetic support, and a magnetic layer including ferromagnetic powder, a binding agent, and fatty acid ester on the non-magnetic support, a full width at half maximum of spacing distribution measured by optical interferometry regarding a surface of the magnetic layer before performing a vacuum heating with respect to the magnetic tape is greater than 0 nm and equal to or smaller than 7.0 nm, a full width at half maximum of spacing distribution measured after performing the vacuum heating is greater than 0 nm and equal to or smaller than 7.0 nm, and a difference between a spacing measured by optical interferometry regarding the surface of the magnetic layer after performing the vacuum heating with respect to the magnetic tape and a spacing measured before performing the vacuum heating is greater than 0 nm and equal to or smaller than 9.0 nm.

Claims

1. A magnetic tape device comprising:

a magnetic tape; and

a reproducing head,

wherein 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, a binding agent, and fatty acid ester on the non-magnetic support,

a full width at half maximum of spacing distribution measured by optical interferometry regarding a surface of the magnetic layer before performing a vacuum heating with respect to the magnetic tape is greater than 0 nm and equal to or smaller than 7.0 nm,

a full width at half maximum of spacing distribution measured by optical interferometry regarding the surface of the magnetic layer after performing the vacuum heating with respect to the magnetic tape is greater than 0 nm and equal to or smaller than 7.0 nm, and

a difference (S_after−

S_before) between a spacing S_after measured by optical interferometry regarding the surface of the magnetic layer after performing the vacuum heating with respect to the magnetic tape and a spacing S_before measured by optical interferometry regarding the surface of the magnetic layer before performing the vacuum heating with respect to the magnetic tape is greater than 0 nm and equal to or smaller than 9.0 nm.

2. The magnetic tape device according to claim 1,

wherein the full width at half maximum of spacing distribution measured by optical interferometry regarding the surface of the magnetic layer before performing the vacuum heating with respect to the magnetic tape is 3.0 nm to 7.0 nm.

3. The magnetic tape device according to claim 1,

wherein the full width at half maximum of spacing distribution measured by optical interferometry regarding the surface of the magnetic layer after performing the vacuum heating with respect to the magnetic tape is 3.0 nm to 7.0 nm.

4. The magnetic tape device according to claim 1,

wherein the difference (S_after−

S_before) is 2.0 nm to 9.0 nm.

5. The magnetic tape device according to claim 1,

wherein a center line average surface roughness Ra measured regarding a surface of the magnetic layer is equal to or smaller than 2.8 nm.

6. The magnetic tape device according to claim 5,

wherein the center line average surface roughness Ra is equal to or smaller than 2.5 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, and

a total thickness of the magnetic layer and the non-magnetic layer is equal to or smaller than 1.8 μ

m.

8. The magnetic tape device according to claim 7,

wherein the total thickness of the magnetic layer and the non-magnetic layer is equal to or smaller than 1.1 μ

m.

9. A magnetic reproducing method comprising:

reproducing information recorded on a magnetic tape by a reproducing head,

wherein 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, a binding agent, and fatty acid ester on the non-magnetic support,

a full width at half maximum of spacing distribution measured by optical interferometry regarding a surface of the magnetic layer before performing a vacuum heating with respect to the magnetic tape is greater than 0 nm and equal to or smaller than 7.0 nm,

a full width at half maximum of spacing distribution measured by optical interferometry regarding the surface of the magnetic layer after performing the vacuum heating with respect to the magnetic tape is greater than 0 nm and equal to or smaller than 7.0 nm, and

a difference (S_after−

S_before) between a spacing S_after measured by optical interferometry regarding the surface of the magnetic layer after performing the vacuum heating with respect to the magnetic tape and a spacing S_before measured by optical interferometry regarding the surface of the magnetic layer before performing the vacuum heating with respect to the magnetic tape is greater than 0 nm and equal to or smaller than 9.0 nm.

10. The magnetic reproducing method according to claim 9,

wherein the full width at half maximum of spacing distribution measured by optical interferometry regarding the surface of the magnetic layer before performing a vacuum heating with respect to the magnetic tape is 3.0 nm to 7.0 nm.

11. The magnetic reproducing method according to claim 9,

wherein the full width at half maximum of spacing distribution measured by optical interferometry regarding the surface of the magnetic layer after performing the vacuum heating with respect to the magnetic tape is 3.0 nm to 7.0 nm.

12. The magnetic reproducing method according to claim 9,

wherein the difference (S_after−

S_before) is 2.0 nm to 9.0 nm.

13. The magnetic reproducing method according to claim 9,

wherein a center line average surface roughness Ra measured regarding a surface of the magnetic layer is equal to or smaller than 2.8 nm.

14. The magnetic reproducing method according to claim 13,

wherein the center line average surface roughness Ra is equal to or smaller than 2.5 nm.

15. The magnetic reproducing method according to claim 9,

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, and

a total thickness of the magnetic layer and the non-magnetic layer is equal to or smaller than 1.8 μ

m.

16. The magnetic reproducing method according to claim 15,

wherein the total thickness of the magnetic layer and the non-magnetic layer is equal to or smaller than 1.1 μ

m.