Tape heads with sub-ambient pressure cavities

Patent metadata

Field	Value
Publication number	US-9761259-B2
Application number	US-201514984671-A
Country	US
Kind code	B2
Filing date	Dec 30, 2015
Priority date	Aug 20, 2014
Publication date	Sep 12, 2017
Grant date	Sep 12, 2017

Abstract

A unidirectional and bi-directional tape head with sub-ambient pressure cavities. The tape head is adapted for reading and/or writing to a magnetic tape. The tape head includes: a tape-bearing surface; a transducer area, having at least one transducer designed for reading and/or writing to the magnetic tape; a cavity open on the tape-bearing surface adjacent to the transducer area that extends parallel to the transducer area and transversally to the longitudinal direction of circulation of the tape such that an opening of the cavity faces the tape in operation; and one or more air bleed slots connected to the cavity. The cavity is further dimensioned and arranged with respect to the transducer area to create, upon circulation of the tape in operation, sub-ambient pressure therein.

First claim

What is claimed is:

1. A bi-directional tape head for reading and/or writing to a magnetic tape, the bi-directional tape head comprising:
a tape-bearing surface that extends a first length perpendicular to a longitudinal direction of circulation of the tape;
a transducer area with at least one transducer that is a read and/or write element designed for reading and/or writing to the magnetic tape, wherein the at least one transducer is arranged along an entire length of the transducer area;
a first cavity open on the tape-bearing surface adjacent to the transducer area that extends parallel to the transducer area and transversally to the longitudinal direction of circulation of the tape such that an opening of the first cavity faces the tape in operation, wherein the first cavity extends a second length perpendicular to the longitudinal direction of circulation of the tape, wherein the second length is less than the first length; and
a second cavity open on the tape-bearing surface, dimensioned and arranged with respect to the transducer area and located opposite to the first cavity with respect to the transducer area, wherein the second cavity extends a third length perpendicular to the longitudinal direction of circulation of the tape, wherein the third length is less than the first length;
wherein the first cavity and second cavity are further dimensioned and arranged with respect to the transducer area to create sub-ambient pressure therein upon circulation of the tape in operation, and
wherein the second length of the first cavity and the third length of the second cavity transversal to the longitudinal direction of circulation of the tape are at least the same as the length of the transducer area and do not exceed the length of the transducer area by more than 0.25mm, wherein the transducer area forms a crenellated structure such that several transducers protrude in a merlon fashion and the crenellated structure is adjacent to the first cavity and the second cavity.

2. The bi-directional tape head of claim 1 , wherein a first depth of the first cavity is between 0.5 and 5.0 μm, and wherein a second depth of the second cavity is between 0.5 and 5.0 μm.

3. The bi-directional tape head of claim 1 , wherein a first width of the first cavity, as measured along the longitudinal direction of circulation of the tape, is between 50 and 200 μm, and wherein a second width of the second cavity, as measured along the longitudinal direction of circulation of the tape, is between 50 and 200 μm.

4. The bi-directional tape head of claim 1 , further comprising an unrecessed area on the tape-bearing surface that extends parallel to the longitudinal direction of the transducer area and transversally to the longitudinal direction of circulation of the tape between the first cavity and the second cavity.

5. The bi-directional tape head of claim 4 , wherein a width of the unrecessed area measured along the longitudinal direction of circulation of the tape is between 25 and 100 μm.

6. The bi-directional tape head of claim 1 , further comprising at least one beveled lateral edge proximal to one of the first cavity and the second cavity that extends parallel to the longitudinal direction of the transducer area and transversally to the longitudinal direction of circulation of the tape.

7. The bi-directional tape head of claim 1 , further comprising at least one rounded lateral edge proximal to one of the first cavity and the second cavity and contiguous with a lateral edge surface of the bi-directional tape head, wherein the rounded lateral edge extends parallel to the longitudinal direction of the transducer area and transversally to the longitudinal direction of circulation of the tape.

8. The bi-directional tape head of claim 1 , further comprising one or more air bleed slots connected to the first cavity and the second cavity.

9. The bi-directional tape head of claim 8 , wherein the one or more air bleed slots are arranged to ensure fluid communication between the first cavity and at least one of a lateral edge surface and the second cavity of the bi-directional tape head.

10. The bi-directional tape head of claim 8 , wherein each of the one or more air bleed slots has a width that is between 3 and 100 μm measured transversally to the longitudinal direction of circulation of the tape, and parallel to the longitudinal direction of the transducer area.

11. The bi-directional tape head of claim 8 , wherein each of the one or more air bleed slots has a depth between 0.3 and 5.0 μm.

12. The bi-directional tape head of claim 1 ,
wherein the first cavity further comprises:
a first cavity wall extending perpendicular to a lateral axis of the bi-directional tape head and disposed at a first end of the first cavity; and
a second cavity wall extending perpendicular to the lateral axis and disposed at a second end of the first cavity, and
wherein the second cavity further comprises:
a third cavity wall extending perpendicular to the lateral axis and disposed at a first end of the second cavity; and
a fourth cavity wall extending perpendicular to the lateral axis and disposed at a second end of the second cavity.

Assignees

• IBM

Inventors

• Engelen Johan B C
• Lantz Mark A
• Rothuizen Hugo E

Classifications

• G11B5/255

  comprising means for protection against wear {(in thin film structures G11B5/3106)} · CPC title

• G11B5/60

  Fluid-dynamic spacing of heads from record-carriers · CPC title

• G11B5/1871 Primary

  Shaping or contouring of the transducing or guiding surface · CPC title

• G11B5/00813 Primary

  magnetic tapes · CPC title

• G11B5/6082 Primary

  Design of the air bearing surface · CPC title