Magnetic tape apparatus

Patent metadata

Field	Value
Publication number	US-10692528-B2
Application number	US-201916456459-A
Country	US
Kind code	B2
Filing date	Jun 28, 2019
Priority date	Jun 29, 2018
Publication date	Jun 23, 2020
Grant date	Jun 23, 2020

Abstract

A magnetic tape apparatus, in which full widths at half maximum of spacing distribution measured by optical interferometry regarding a surface of a magnetic layer before and after performing a vacuum heating with respect to the magnetic tape are greater than 0 nm and equal to or smaller than 15.0 nm, a difference between spacings measured by optical interferometry regarding the surface of the magnetic layer before and after performing the vacuum heating is greater than 0 nm and equal to or smaller than 12.0 nm, and 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.

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, 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 15.0 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 15.0 nm,
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 12.0 nm,
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, and
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.

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 1 ,
wherein the deviation amount is determined in accordance with a result obtained by reading a servo pattern applied to the magnetic tape in advance, by a servo element.

15. The magnetic tape apparatus according to claim 14 ,
wherein a reading operation by the reading element unit is performed synchronously with a reading operation by the servo element.

16. 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.

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

18. The magnetic tape apparatus 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 2.0 nm to 15.0 nm.

19. The magnetic tape apparatus 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 2.0 nm to 15.0 nm.

20. The magnetic tape apparatus according to claim 1 ,
wherein the difference S after −S before is 1.0 nm to 12.0 nm.

Assignees

• Fujifilm Corp

Inventors

• Ozawa Eiki
• Kasada Norihito
• Musha Atsushi

Classifications

• G11B5/78 Primary

  Tape carriers · CPC title

• G11B20/10046

  filtering or equalising, e.g. setting the tap weights of an FIR filter · CPC title

• G11B5/00813

  magnetic tapes · CPC title

• G11B5/584

  for track following on tapes · CPC title

• G11B20/10055 Primary

  using partial response filtering when writing the signal to the medium or reading it therefrom · CPC title