Apparatus capable of determining deviation amount between magnetic head and magnetic tape based on reading servo pattern

Patent metadata

Field	Value
Publication number	US-10755735-B2
Application number	US-201916456965-A
Country	US
Kind code	B2
Filing date	Jun 28, 2019
Priority date	Jun 29, 2018
Publication date	Aug 25, 2020
Grant date	Aug 25, 2020

Abstract

A magnetic tape apparatus, in which a tilt cos θ of the hexagonal ferrite powder with respect to a surface of the magnetic layer acquired by cross section observation by STEM is 0.85 to 1.00, a reading element unit includes a plurality of reading elements each of which reads data by a linear scanning method from a specific track region including a reading target track in a track region included in the magnetic tape, an extraction unit performs a waveform equalization process according to a deviation amount between positions of the magnetic tape and the reading element unit, with respect to each reading result for each reading element, to extract data derived from the reading target track from the reading result, and the deviation amount is determined in accordance with a result obtained by reading of the servo pattern included in the magnetic layer by a servo element.

First claim

What is claimed is:

1. A magnetic tape apparatus comprising:
a magnetic tape;
a reading element unit; and
an extraction unit,
wherein the magnetic tape includes a non-magnetic support, and a magnetic layer including a ferromagnetic powder and a binding agent on the non-magnetic support,
the magnetic layer includes a servo pattern,
the ferromagnetic powder is a hexagonal ferrite powder,
a tilt cos θ of the hexagonal ferrite powder with respect to a surface of the magnetic layer acquired by cross section observation performed by using a scanning transmission electron microscope is 0.85 to 1.00,
the reading element unit includes a plurality of reading elements each of which reads data by a linear scanning method from a specific track region including a reading target track in a track region included in the magnetic tape,
the extraction unit performs a waveform equalization process according to a deviation amount between positions of the magnetic tape and the reading element unit, with respect to each reading result for each reading element, to extract data derived from the reading target track from the reading result, and
the deviation amount is determined in accordance with a result obtained by reading of the servo pattern included in the magnetic layer of the magnetic tape by a servo element.

2. The magnetic tape apparatus according to claim 1 ,
wherein parts of the plurality of reading elements are overlapped each other in a running direction of the magnetic tape.

3. The magnetic tape apparatus according to claim 2 ,
wherein the specific track region is a region including the reading target track and adjacent tracks which are adjacent to the reading target track, and
each of the plurality of reading elements straddles over both of the reading target track and the adjacent track, in a case where a positional relationship with the magnetic tape is changed.

4. The magnetic tape apparatus according to claim 1 ,
wherein the plurality of reading elements are disposed in a line in a state of being adjacent to each other, in a width direction of the magnetic tape.

5. The magnetic tape apparatus according to claim 1 ,
wherein the plurality of reading elements fall in the reading target track in a width direction of the magnetic tape.

6. The magnetic tape apparatus according to claim 1 ,
wherein the waveform equalization process is performed by using a tap coefficient determined in accordance with the deviation amount.

7. The magnetic tape apparatus according to claim 6 ,
wherein, regarding each of the plurality of reading elements, a ratio between an overlapping region with the reading target track and an overlapping region with an adjacent track which is adjacent to the reading target track is specified from the deviation amount, and the tap coefficient is determined in accordance with the specified ratio.

8. The magnetic tape apparatus according to claim 2 ,
wherein the waveform equalization process is performed by using a tap coefficient determined in accordance with the deviation amount.

9. The magnetic tape apparatus according to claim 8 ,
wherein, regarding each of the plurality of reading elements, a ratio between an overlapping region with the reading target track and an overlapping region with an adjacent track which is adjacent to the reading target track is specified from the deviation amount, and the tap coefficient is determined in accordance with the specified ratio.

10. The magnetic tape apparatus according to claim 3 ,
wherein the waveform equalization process is performed by using a tap coefficient determined in accordance with the deviation amount.

11. The magnetic tape apparatus according to claim 10 ,
wherein, regarding each of the plurality of reading elements, a ratio between an overlapping region with the reading target track and an overlapping region with an adjacent track which is adjacent to the reading target track is specified from the deviation amount, and the tap coefficient is determined in accordance with the specified ratio.

12. The magnetic tape apparatus according to claim 4 ,
wherein the waveform equalization process is performed by using a tap coefficient determined in accordance with the deviation amount.

13. The magnetic tape apparatus according to claim 12 ,
wherein, regarding each of the plurality of reading elements, a ratio between an overlapping region with the reading target track and an overlapping region with an adjacent track which is adjacent to the reading target track is specified from the deviation amount, and the tap coefficient is determined in accordance with the specified ratio.

14. The magnetic tape apparatus according to claim 5 ,
wherein the waveform equalization process is performed by using a tap coefficient determined in accordance with the deviation amount.

15. The magnetic tape apparatus according to claim 14 ,
wherein, regarding each of the plurality of reading elements, a ratio between an overlapping region with the reading target track and an overlapping region with an adjacent track which is adjacent to the reading target track is specified from the deviation amount, and the tap coefficient is determined in accordance with the specified ratio.

16. The magnetic tape apparatus according to claim 1 ,
wherein a reading operation by the reading element unit is performed synchronously with a reading operation by the servo element.

17. The magnetic tape apparatus according to claim 1 ,
wherein the extraction unit includes a two-dimensional FIR filter, and the two-dimensional FIR filter composes each result obtained by performing the waveform equalization process with respect to each reading result for each reading element, to extract data derived from the reading target track from the reading result.

18. The magnetic tape apparatus according to claim 1 ,
wherein the plurality of reading elements are a pair of reading elements.

19. The magnetic tape apparatus according to claim 1 ,
wherein an activation volume of the hexagonal ferrite powder is equal to or smaller than 1,600 nm 3 .

Assignees

• Fujifilm Corp

Inventors

• Ozawa Eiki
• Kasada Norihito
• Musha Atsushi

Classifications

• G11B15/46

  Controlling, regulating, or indicating speed {(dependent on position of tape in reserve, loop G11B15/56, G11B15/58)} · CPC title

• G11B5/70

  on a base layer · CPC title

• G11B5/012

  Recording on, or reproducing or erasing from, magnetic disks (G11B17/00, G11B19/00 take precedence) · CPC title

• G11B5/00817

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

• G11B5/09

  Digital recording · CPC title