Magnetic tape apparatus

• US 10,643,647 B2
• Filed: 06/28/2019
• Issued: 05/05/2020
• Est. Priority Date: 06/29/2018
• Status: Active Grant

• Current Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Original Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Inventors: Kasada, Norihito, Ozawa, Eiki, Musha, Atsushi
• Primary Examiner(s): Agustin, Peter Vincent
• Application Number:
  US16/456,811
• Publication Number:
  US 20200005822A1
• Time in Patent Office: 312 Days
• Field of Search: None
• CPC Class Codes: G11B 15/46 Controlling, regulating, or indicating speed dependent on position of tape in reserve, loop G11B15/56, G11B15/58
• CPC Class Codes: G11B 5/00817 on longitudinal tracks only, e.g. for serpentine format recording
• CPC Class Codes: G11B 5/09 Digital recording
• CPC Class Codes: G11B 5/5508 Control circuits therefor G11B5/5513 takes precedence
• CPC Class Codes: G11B 5/70 on a base layer
• CPC Class Codes: G11B 5/70678 Ferrites

Abstract

A magnetic tape apparatus, in which an intensity ratio of peak intensity of diffraction peak of (110) plane with respect to peak intensity of diffraction peak of (114) plane of a hexagonal ferrite crystal structure obtained by XRD analysis of the magnetic layer by In-Plane method is 0.5 to 4.0, a vertical squareness ratio of the magnetic tape is 0.65 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, and 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.

Claims

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,

an intensity ratio Int(110)/Int(114) of a peak intensity Int(110) of a diffraction peak of a (110) plane with respect to a peak intensity Int(114) of a diffraction peak of a (114) plane of a hexagonal ferrite crystal structure obtained by an X-ray diffraction analysis of the magnetic layer by using an In-Plane method is 0.5 to 4.0,

a vertical squareness ratio of the magnetic tape is 0.65 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 the vertical squareness ratio of the magnetic tape is 0.65 to 0.90.

20. 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 nm³.