Magnetic tape device

Patent metadata

Field	Value
Publication number	US-11735213-B2
Application number	US-202217872566-A
Country	US
Kind code	B2
Filing date	Jul 25, 2022
Priority date	Jul 26, 2021
Publication date	Aug 22, 2023
Grant date	Aug 22, 2023

Abstract

A magnetic tape device. The angle θ formed by the axis of the element array of the magnetic head with respect to a width direction of the magnetic tape is changed during running of the magnetic tape in the magnetic tape device. The magnetic tape satisfies Equation 1: TDSage+TDSenv−TC≤0.10 μm. In Equation 1, the TDSage is a maximum value of an absolute value of a difference between a servo band spacing obtained before storage for 24 hours in a predetermined environment and a servo band spacing obtained after the storage. TDSenv is a value calculated by multiplying a difference between a maximum value and a minimum value of servo band spacings obtained in each of five predetermined environments by ½, and TC is a value calculated by TC=L{cos (θinitial−Δθ)−cos (θinitial+Δθ)}.

First claim

What is claimed is:

1. A magnetic tape device comprising:
a magnetic tape; and a magnetic head,
wherein the magnetic head includes a module including an element array including a plurality of magnetic head elements between a pair of servo signal reading elements,
the magnetic tape device changes an angle θ formed by an axis of the element array with respect to a width direction of the magnetic tape during running of the magnetic tape in the magnetic tape device,
the magnetic tape includes a non-magnetic support, and a magnetic layer including a ferromagnetic powder,
the magnetic layer includes a plurality of servo bands,
Equation 1 below is satisfied,
TD Sage+ TD Senv− TC≤ 0.10 μm,  (Equation 1)

in Equation 1,
the TDSage is a maximum value of an absolute value of a difference between a servo band spacing obtained before storage for 24 hours in an environment of a temperature 60° C. and relative humidity of 20% and a servo band spacing obtained after the storage, and a unit is μm,
the TDSenv is a value calculated by multiplying a difference between a maximum value and a minimum value of servo band spacings obtained in each of the following five environments of
a temperature of 16° C. and relative humidity of 20%,
a temperature of 16° C. and relative humidity of 80%,
a temperature of 26° C. and relative humidity of 80%,
a temperature of 32° C. and relative humidity of 20%, and
a temperature of 32° C. and relative humidity of 55%,
by ½, and a unit is μm, and
the TC is a value calculated by
TC=L {cos(θ initial −Δθ)−cos(θ initial +Δθ)},

a unit is μm,
the L is a distance between the pair of servo signal reading elements and a unit is μm, and
in a case where the angle θ at start of the running of the magnetic tape is defined as θ initial ,
a maximum value of the angle θ during the running of the magnetic tape is defined as θ max , and a minimum value thereof is defined as θ min , and
the Δθ is a greater value between values calculated by
Δθ max =θ max −θ initial and

Δθ min =θ initial −θ min .

2. The magnetic tape device according to claim 1 ,
wherein the θ initial is 1.000° to 45.000°.

3. The magnetic tape device according to claim 1 ,
wherein the Δθ is more than 0.000° and 1.000° or less.

4. The magnetic tape device according to claim 2
wherein the Δθ is more than 0.000° and 1.000° or less.

5. The magnetic tape device according to claim 1 ,
wherein the angle θ formed by the axis of the element array with respect to the width direction of the magnetic tape during the running of the magnetic tape in the magnetic tape device is changed according to dimensional information of the magnetic tape in the width direction obtained during the running.

6. The magnetic tape device according to claim 1 ,
wherein the magnetic tape has a tape thickness of 5.6 μm or less.

7. The magnetic tape device according to claim 1 ,
wherein the magnetic tape has a tape thickness of 5.3 μm or less.

8. The magnetic tape device according to claim 1 ,
wherein the magnetic tape further includes a non-magnetic layer including a non-magnetic powder between the non-magnetic support and the magnetic layer.

9. The magnetic tape device according to claim 1 ,
wherein the magnetic tape further includes a back coating layer including a non-magnetic powder on a surface side of the non-magnetic support opposite to a surface side on which the magnetic layer is provided.

10. The magnetic tape device according to claim 1 ,
wherein the non-magnetic support is an aromatic polyester support.

11. The magnetic tape device according to claim 10 ,
wherein the aromatic polyester support is a polyethylene terephthalate support.

12. The magnetic tape device according to claim 10 ,
wherein the aromatic polyester support is a polyethylene naphthalate support.

13. The magnetic tape device according to claim 1 ,
wherein a vertical squareness ratio of the magnetic tape is 0.60 or more.

14. The magnetic tape device according to claim 4 ,
wherein a vertical squareness ratio of the magnetic tape is 0.60 or more.

Assignees

• Fujifilm Corp

Inventors

• Kasada Norihito
• Musha Atsushi

Classifications

• G11B5/5926 Primary

  recorded in separate tracks, e.g. servo tracks · CPC title

• G11B5/00813

  magnetic tapes · CPC title

• G11B5/739

  Magnetic recording media substrates · CPC title

• G11B5/73927 Primary

  Polyester substrates, e.g. polyethylene terephthalate · CPC title

• G11B5/584

  for track following on tapes · CPC title