Tape heads with sub-ambient pressure cavities

Patent metadata

Field	Value
Publication number	US-9734854-B2
Application number	US-201514829921-A
Country	US
Kind code	B2
Filing date	Aug 19, 2015
Priority date	Aug 20, 2014
Publication date	Aug 15, 2017
Grant date	Aug 15, 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; and 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. 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. The present invention allows for a very close tape-head spacing.

First claim

What is claimed is:

1. A unidirectional tape head for reading and/or writing to a magnetic tape, the tape head comprising:
a tape-bearing surface of a tape head body;
a transducer area on the tape-bearing surface of the tape head body with at least one transducer that is a read and/or write element designed for reading and/or writing to the magnetic tape;
a cavity open on the tape-bearing surface adjacent to the transducer area on the tape head body, wherein the cavity 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,
wherein the cavity is directly adjacent to a front lateral edge of the unidirectional tape head, wherein the front lateral edge is between a top side and a front side of the unidirectional tape head in a horizontal direction at a forward end at which the magnetic tape is initially incident and moves along toward a back end of the unidirectional tape head in the horizontal direction,
wherein the cavity is 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 length of the cavity transversal to the longitudinal direction of circulation of the tape is at least the same as the length of the transducer area and does not exceed the length of the transducer area by more than 0.25 mm.

2. The tape head of claim 1 , wherein the depth of the cavity is between 0.5 and 5.0 μm.

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

4. The tape head of claim 1 , wherein the tape head comprises several transducers arranged along the longitudinal direction of the transducer area and transversally to the longitudinal direction of circulation of the tape.

5. The 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 cavity and the transducer area, and
wherein a width of the unrecessed area in the longitudinal direction of circulation of the tape is no more than half a width of the cavity in the longitudinal direction of circulation of the tape.

6. The tape head of claim 1 , wherein the width of an unrecessed area measured along the longitudinal direction of circulation of the tape is between 25 and 100 μm.

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

8. The tape head of claim 1 , further comprising at least one rounded lateral edge proximal to the cavity and contiguous with a lateral edge surface of the 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.

9. The tape head of claim 1 , wherein there is no other cavities between the cavity and the front lateral edge.

10. The tape head of claim 1 , wherein the cavity is closer to the front lateral edge than the back end of the tape-bearing surface.

11. The tape head of claim 1 ,
wherein the tape-bearing surface extends a first length perpendicular to the longitudinal direction of circulation of the tape, and
wherein the 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.

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

13. An apparatus for reading and/or writing to tapes, comprising one or more unidirectional tape heads comprising:
a tape-bearing surface of a tape head body;
a transducer area on the tape-bearing surface of the tape head body with at least one transducer that is a read and/or write element designed for reading and/or writing to a magnetic tape;
a cavity open on the tape-bearing surface adjacent to the transducer area on the tape head body, wherein the cavity 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,
wherein the cavity is directly adjacent to a front lateral edge of the unidirectional tape head, wherein the front lateral edge is between a top side and a front side of the unidirectional tape head in a horizontal direction at a forward end at which the magnetic tape is initially incident and moves along toward a back end of the unidirectional tape head in the horizontal direction,
wherein the cavity is 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 length of the cavity transversal to the longitudinal direction of circulation of the tape is at least the same as the length of the transducer area and does not exceed the length of the transducer area by more than 0.25 mm.

Assignees

• IBM

Inventors

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

Classifications

• G11B5/1871 Primary

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

• G11B5/60

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

• G11B5/255

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

• G11B5/00813 Primary

  magnetic tapes · CPC title

• G11B5/6082 Primary

  Design of the air bearing surface · CPC title