Write head for a magnetic tape medium with magnetically encoded servo band bursts

Patent metadata

Field	Value
Publication number	US-9443539-B2
Application number	US-201514791659-A
Country	US
Kind code	B2
Filing date	Jul 6, 2015
Priority date	Jun 28, 2012
Publication date	Sep 13, 2016
Grant date	Sep 13, 2016

Abstract

A write head for writing a servo pattern to a magnetic tape medium includes a first coil configured to generate a first magnetic flux when applying an electric current to the first coil, a second coil configured to generate a second magnetic flux when applying an electric current to the second coil, and a pole piece structure configured to guide the generated magnetic flux. The pole piece includes a first ring structure for guiding the first magnetic flux, a second ring structure for guiding the second magnetic flux, and a common section of the first and the second ring structure which common section is arranged between the first coil and the second coil. The write head further includes a section containing a gap in each of the first ring structure and the second ring structure. The magnetic flux is oriented in opposite directions across the two gaps.

First claim

The invention claimed is:

1. A magnetic tape medium and write head for writing at least one servo pattern on the magnetic tape medium comprising:
a first coil configured to generate a first magnetic flux when applying an electric current to the first coil;
a second coil configured to generate a second magnetic flux when applying an electric current to the second coil;
a pole piece structure configured to guide the generated magnetic flux, comprising a first ring structure for guiding the first magnetic flux, a second ring structure for guiding the second magnetic flux, and a common section of the first and the second ring structure, which common section is arranged between the first coil and the second coil; and
a section containing a gap in each of the first ring structure and the second ring structure, wherein the magnetic flux is oriented in opposite directions across the two gaps, and wherein the sections containing the gaps are oriented in a common plane;
wherein the magnetic tape medium comprises:
at least one servo band along a longitudinal extension of the tape medium, the at least one servo band comprising servo patterns organized in servo frames for supporting to determine positional information;
at least one of the servo frames comprising a first burst comprising at least two servo stripes inclined at a first angle with respect to a direction orthogonal to the longitudinal extension of the tape medium, followed by a second burst comprising at least two servo stripes inclined at a second angle with respect to the direction orthogonal to the longitudinal extension of the tape medium, which second angle is different from the first angle; and
wherein at least one of the stripes of the first burst has a first magnetic polarity, and wherein at least one of the stripes of the second burst has a second magnetic polarity different from the first magnetic polarity; and

for at least one of the first and second bursts, different stripes within a same burst have opposite magnetic polarities with respect to one another.

2. The magnetic tape medium and write head of claim 1 , wherein the first burst is immediately followed by the second burst in a longitudinal direction of the tape medium such that a last stripe of the first burst is followed by a first stripe of the second burst.

3. The magnetic tape medium and write head of claim 1 , wherein:
a number of servo stripes in the first burst is equal to a number of servo stripes in the second burst;
two stripes residing at a same position in the first burst and the second burst are collectively denoted as a pair of stripes; and
each pair of stripes in the first burst and the second burst contains stripes of one of the first magnetic polarity and the second magnetic polarity.

4. The magnetic tape medium and write head of claim 3 , wherein:
at least one pair of stripes contains one stripe having the first polarity and one stripe having the second polarity; and
each pair of stripes in the first and the second burst contain one stripe having the first polarity and one stripe having the second polarity.

5. The magnetic tape medium and write head of claim 3 , wherein at least one pair of stripes at a defined position in the servo frame contains predefined magnetic polarity in its stripes representing a synchronization pattern.

6. The magnetic tape medium and write head of claim 5 , wherein:
the at least one servo band comprises a set of servo frames;
each servo frame of the set of servo frames comprises a first burst and a second burst; and
each servo frame of the set of servo frames contains the predefined magnetic polarity in the at least one pair of stripes representing the synchronization pattern.

7. The magnetic tape medium and write head of claim 3 , wherein:
at least one pair of stripes at a defined position in the servo frame contains magnetic polarity of its stripes representing encoded information; and
the encoded information contains one or more of a servo band identifier and a longitudinal direction position.

8. The magnetic tape medium and write head of claim 7 , wherein:
the at least one servo band comprises a set of servo frames;
each servo frame of the set of servo frames comprises a first burst and a second burst;
each servo frame of the set of servo frames contains at least one pair of stripes containing magnetic polarities in its stripes representing the encoded information; and
the stripes of the at least one pair of stripes representing encoded information have a different magnetic polarity irrespective of the information encoded.

Assignees

• IBM

Inventors

• Cherubini Giovanni
• Engelen Johan B C
• Furrer Simeon
• Lantz Mark A

Classifications

• G11B20/1201 Primary

  on tapes · CPC title

• G11B5/00817 Primary

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

• G11B2220/956

  Linear tape open [LTO] format · CPC title

• G11B5/00826

  comprising a plurality of single poles or gaps or groups thereof operative at the same time · CPC title

• G11B5/584

  for track following on tapes · CPC title