Magnetic tape device and head tracking servo method

• US 9,972,351 B1
• Filed: 12/26/2017
• Issued: 05/15/2018
• Est. Priority Date: 12/27/2016
• Status: Active Grant

• Current Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Original Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Inventors: Kaneko, Tetsuya, Kasada, Norihito, Ozawa, Eiki
• Primary Examiner(s): Young, Wayne
• Assistant Examiner(s): Habermehl, James L
• Application Number:
  US15/854,410
• Time in Patent Office: 140 Days
• Field of Search: 360 55, 360 69, 360 75, 360 7712, 360134
• CPC Class Codes: G11B 5/00826 comprising a plurality of single poles or gaps or groups thereof operative at the same time
• 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 5/68 comprising one or more layers of magnetisable material homogeneously mixed with a bonding agent
• CPC Class Codes: G11B 5/70 on a base layer
• CPC Class Codes: G11B 5/702 characterised by the bonding agent
• CPC Class Codes: G11B 5/84 Processes or apparatus specially adapted for manufacturing record carriers

Abstract

The magnetic tape device including: a magnetic tape; and a servo head, in which 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, and logarithmic decrement acquired by a pendulum viscoelasticity test performed regarding a surface of the magnetic layer is equal to or smaller than 0.050.

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, and

logarithmic decrement acquired by a pendulum viscoelasticity test performed regarding a surface of the magnetic layer is equal to or smaller than 0.050.

2. The magnetic tape device according to claim 1,

wherein the logarithmic decrement is 0.010 to 0.050.

3. 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.

4. The magnetic tape device according to claim 3,

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

5. 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.

6. The magnetic tape device according to claim 5,

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

m.

7. 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, and

logarithmic decrement acquired by a pendulum viscoelasticity test performed regarding a surface of the magnetic layer is equal to or smaller than 0.050.

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

wherein the logarithmic decrement is 0.010 to 0.050.

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

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.

10. The head tracking servo method according to claim 9,

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

11. The head tracking servo 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, and

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

m.

12. The head tracking servo method according to claim 11,

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

m.