U.S. patent application number 12/245377 was filed with the patent office on 2009-01-29 for high areal density tape head.
This patent application is currently assigned to INTERNATIONAL BUSINESS MACHINES CORPORATION. Invention is credited to Robert G. Biskeborn, Wayne I. Imaino.
Application Number | 20090027803 12/245377 |
Document ID | / |
Family ID | 39497700 |
Filed Date | 2009-01-29 |
United States Patent
Application |
20090027803 |
Kind Code |
A1 |
Biskeborn; Robert G. ; et
al. |
January 29, 2009 |
High Areal Density Tape Head
Abstract
A tape head designed for transducing data on a magnetic
recording tape that is subject to tape dimensional changes. The
tape head includes two or more arrays of transducer elements having
different transducer spacing distances corresponding to different
track spacing distances to be transduced. One of the transducer
arrays may be used for transducing the tape under nominal tape
track spacing conditions. Another transducer array may be used for
transducing the tape when the tape track spacing is reduced due to
the tape shrinkage. Still another transducer array may be used for
transducing the tape when the tape track spacing is enlarged due to
tape expansion.
Inventors: |
Biskeborn; Robert G.;
(Hollister, CA) ; Imaino; Wayne I.; (San Jose,
CA) |
Correspondence
Address: |
WALTER W. DUFT
8616 MAIN STREET, SUITE 2
WILLIAMSVILLE
NY
14221
US
|
Assignee: |
INTERNATIONAL BUSINESS MACHINES
CORPORATION
Armonk
NY
|
Family ID: |
39497700 |
Appl. No.: |
12/245377 |
Filed: |
October 3, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
11609725 |
Dec 12, 2006 |
|
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12245377 |
|
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Current U.S.
Class: |
360/77.12 ;
G9B/5.158; G9B/5.203 |
Current CPC
Class: |
G11B 5/584 20130101 |
Class at
Publication: |
360/77.12 ;
G9B/5.203; G9B/5.158 |
International
Class: |
G11B 5/584 20060101
G11B005/584 |
Claims
1: A tape head for transducing data on a magnetic recording tape
that is subject to tape dimensional changes comprising two or more
arrays of transducer elements having different transducer spacing
distances corresponding to different track spacing distances to be
transduced.
2: A tape head in accordance with claim 1 wherein there are two
transducer arrays that respectively utilize a first transducer
spacing distance corresponding to a nominal tape track spacing
distance and a second transducer spacing distance corresponding to
a reduced tape track spacing distance caused by tape shrinkage.
3: A tape head in accordance with claim 1 wherein there are three
transducer arrays that respectively comprise a first transducer
spacing distance corresponding to a nominal tape track spacing
distance, a second transducer spacing distance corresponding to a
reduced tape track spacing distance caused by tape shrinkage, and a
third transducer spacing distance corresponding to an enlarged tape
track spacing distance caused by tape expansion.
4: A tape head in accordance with claim 1 wherein said arrays are
spaced from each other in a cross-track direction.
5: A tape head in accordance with claim 1 wherein said arrays are
spaced from each other in a direction of tape motion.
6: A tape head in accordance with claim 1 wherein said arrays each
include one or both of write transducer elements and read
transducer elements, and wherein said arrays each further include a
pair of servo read transducer elements.
7: A tape head in accordance with claim 1 wherein said arrays are
supported by a common substrate as part of a tape head module.
8: A tape head in accordance with claim 1 wherein said tape head
comprises a first array group on a first tape head module and a
second array group on a second tape head module.
9: A tape head in accordance with claim 1 wherein said first and
second array groups each comprise read and write transducer
elements.
10: A tape head in accordance with claim 9 wherein said read and
write transducer elements are arranged in one of an interleaved or
piggy back configuration.
11: A tape head in accordance with claim 1 wherein said tape head
comprise a first array group on a first tape head module, a second
array group on a second tape head module, and a third array group
on a third tape head module.
12: A tape head in accordance with claim 11 wherein said first and
third array groups comprise write transducer elements and said
second array group comprises read transducer elements.
13: A tape head in accordance with claim 12 wherein said second
tape head module is disposed between said first and third tape head
modules.
14-20. (canceled)
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates to tape drive data storage systems.
More particularly, the invention is directed to thin film tape
heads for reading and writing data on magnetic recording tape.
[0003] 2. Description of the Prior Art
[0004] Thin film tape heads for magnetic information storage
systems (e.g., tape drives) have been constructed using thin film
fabrication techniques that are similar to those used in the
manufacture of disk drive transducers. In a typical tape head
constructed for linear recording (i.e., with data tracks oriented
in the direction of tape movement) there are two or more adjacently
mounted transducer modules. Each module comprises a linear array of
reader and/or writer transducer elements arranged in a cross-track
direction that is perpendicular to the direction of tape movement.
Each transducer element in a given transducer array is positioned
to write or read a separate longitudinal track on the tape. This
arrangement is shown in FIG. 1, which depicts a transducer module
"M" having an array of thin film transducer elements "E" whose gaps
"G" engage a tape "T" in alignment with tracks "TR" that extend in
the direction of tape movement "D. In a "piggy back" design (see
FIG. 2A), the transducer array "E" would comprise a write
transducer "W" and a closely spaced read transducer "R" at each
track position. In an interleaved design (see FIG. 2B), the
transducer array "E" would comprise alternating read and write
elements "R" and "W." In each design, the transducer array "E" may
also include a pair of servo read transducers "SR" that align with
servo tracks "ST" used for head positioning.
[0005] As shown in FIG. 3, the module "M" of FIG. 1 can be secured
to a mounting block "MB" in association with a complimentary tape
head "M'" comprising either piggy back or interleaved read and
write elements. The resultant assembly, which may be referred to as
a "tape head," will have read/write element pairs that are aligned
in the trackwise direction of the tape "T." In the piggy back
design, there will be two read/write element pairs per track (see
FIG. 4A). In the interleaved design, the read and write elements of
each module "M" and "M'" will be arranged so that there is one read
element and one write element for each track (see FIG. 4B). The
dual module arrangement allows data recording (and playback) to be
performed in both tape directions and provides conventional
read-while write capability in which data written to the tape "T"
is immediately read back and checked for errors. Other conventional
tape head designs include heads in which all of the data transducer
elements are read elements or write elements. Read-while write
capability may then be achieved by combining a read-only module and
a write-only module in a single tape head to provide
trackwise-aligned read and write element pairs. As shown in FIG. 5,
bi-directional recording with read-while write capability can be
provided by placing a read-only module "M'" between a pair of
write-only modules "M."
[0006] A characteristic of tape head constructions as described
above is that the gap pitch within the transducer array "E" is
usually much larger than the gap width, such that for every track
being read or written by the array, there will be space between the
tracks where no transducing occurs. Thus, for every pair of tracks
aligned with adjacent read and write elements "R" and "W," there is
inter-track white space on the tape "T" that is not transduced
concurrently with the selected pair. The white space regions can be
recorded with data by stepping the tape head in a cross-track
direction during multiple transducing passes. Tape tracks can also
be written at less than the gap width of the write transducers
using a process known as "shingling." According to this technique,
the tape head is stepped by less than the write element gap width
for each successive transducing pass, such that the edge of a
previously written track is overwritten during the next pass, much
like shingles on a roof.
[0007] Although the foregoing track writing techniques allow data
to be densely packed on a tape, a continuing unresolved problem is
track misregistration caused by tape dimensional changes between
transducing (either reading or writing) operations. For example,
the tape "T" may be written with data under one set of temperature
and humidity conditions, and then later read following exposure to
different environmental conditions. For conventional tape material,
the dimensions can change by as much as 0.12%. These tape
dimensional changes will widen or narrow the tape track spacing
geometry, resulting in track misregistration with the tape head
(whose gap spacing geometry is substantially unchanged). Providing
a head that is statically rotated to a nominal predetermined angle
addresses the misregistration problem because small changes in
rotation change the effective track pitch of the transducer array
"E." However, this solution requires sophisticated mechanics and
skew compensation circuitry.
[0008] The track misregistration problem is exacerbated in
conventional tape heads due to the relatively large gap spacing of
the transducer array "E." which is mandated to a large extent by
the size of the transducers themselves. This is due to the fact
that for any percentage change in tape dimension, the actual
misregistration between written tracks and outermost transducers
depends on the span between the transducers. To illustrate, if the
transducer array "E" has a transducer element gap pitch of x .mu.m,
and the percentage change in tape dimension is 0.12%, the resultant
change in the spacing of the tape tracks under the outermost
transducer elements of a sixteen transducer array will be
15.times.0.0012x=0.018x .mu.m. If x is a typical value of 167 .mu.m
(for current generation tape heads), then 0.018x=3 .mu.m. This is a
large part of the TMR (Track MisRegistration) budget. On the other
hand, if the transducer array "E" has a transducer element gap
pitch of 0.5.times..mu.m, then a 0.12% change in tape dimension
will only change the tape track spacing under the outermost
transducer elements by 15x0.0006x .mu.m=0.009x. Again assuming x is
a typical value of 167 .mu.m, then 0.009x=1.5 .mu.m. The 0.5x gap
pitch transducer array will thus experience only half of the tape
dimensional change that is experienced by the x gap pitch array,
such that track misregistration is less likely. Unfortunately,
reducing track pitch using current thin film transducer fabrication
techniques is not a trivial challenge due particularly to the size
requirements of the write element structures. Absent the use of
alternative transducer designs that permit reductions in track
pitch (as previously proposed by one of the applicants herein in
commonly-owned patent application filings), or the use of
complicated head rotation techniques as referred above, there is no
conventional technique for dealing with the thermally induced track
misregistration.
SUMMARY OF THE INVENTION
[0009] The foregoing problems are solved and an advance in the art
is obtained by a tape head designed for transducing data on a
magnetic recording tape that is subject to tape dimensional
changes. The tape head includes two or more arrays of transducer
elements having different transducer spacing distances
corresponding to different track spacing distances to be
transduced. One of the transducer arrays may be used for
transducing the tape under nominal tape track spacing conditions.
Another transducer array may be used for transducing the tape when
the tape track spacing is reduced due to the tape shrinkage. Still
another transducer array may be used for transducing the tape when
the tape track spacing is enlarged due to tape expansion.
Alternatively, the first transducer array can be used and the tape
can be stretched longitudinally to reduce the tape track spacing to
the nominal tape track spacing.
[0010] According to exemplary embodiments disclosed herein, the
arrays may be spaced from each other in a cross-track direction or
they may be spaced from each other in a direction of tape motion.
The arrays may each include one or both of write transducer
elements and read transducer elements. The arrays may each further
include a pair of servo read transducer elements. The arrays may be
supported by a common substrate as part of a tape head module, and
plural modules may be provided. For example, the tape head may
include a first array group on a first tape head module and a
second array group on a second tape head module. In this two-module
configuration, the first and second array groups may each comprise
read and write transducer elements arranged in one of an
interleaved configuration or a piggy back configuration. The tape
head may alternatively include a first array group on a first tape
head module, a second array group on a second tape head module, and
a third array group on a third tape head module. In this
three-module configuration, the first and third array groups may
comprise write transducer elements and the second array group may
comprise read transducer elements. The second tape head module may
be disposed between the first and third tape head modules.
[0011] The invention in another aspect provides a method for
writing data on a magnetic recording tape while accommodating tape
dimensional changes The method includes determining a dimensional
condition of the tape, as by reading prerecorded servo markings on
the tape, and selecting one of the first and second transducer
arrays for transducing according to which of the first transducer
spacing distance and the second transducer spacing distance most
closely corresponds to the tape dimensional condition. A first one
of the transducer arrays having a nominal transducer spacing
distance may be used for transducing the tape under nominal tape
track spacing conditions and a second one of the transducer arrays
having a reduced transducer spacing distance may be used for
transducing the tape when the tape track spacing is reduced due to
tape shrinkage. The tape may also be transduced by the first
transducer array when tape track spacing distance is enlarged due
to tape expansion while stretching the tape in a longitudinal
direction to reduce the enlarged tape track spacing distance to a
near nominal tape track spacing distance. Alternatively, a third
transducer array having an enlarged transducer spacing distance may
be used for transducing the tape when its track spacing distance is
enlarged.
[0012] The invention in another aspect provides a tape drive. The
tape drive includes a tape head for transducing data on a magnetic
recording tape that is subject to tape dimensional changes. The
tape head includes plural tape head modules, each of which may have
a first array of transducer elements having transducer elements
spaced from each other by a first transducer spacing distance that
corresponds to a nominal tape track spacing distance, a second
array of transducer elements spaced from each other by a second
transducer spacing distance that corresponds to a reduced tape
track spacing distance caused by tape shrinkage, and a third array
of transducer elements spaced from each other by a third transducer
spacing distance that corresponds to an enlarged tape track spacing
distance caused by tape expansion. The arrays may be spaced from
each other in a cross-track direction.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The foregoing and other features and advantages of the
invention will be apparent from the following more particular
description of exemplary disclosed embodiments, as illustrated in
the accompanying Drawings, in which:
[0014] FIG. 1 is a perspective view showing a prior art thin film
tape head module;
[0015] FIG. 2A partial plan view showing a tape bearing surface of
a prior art tape head module having a piggy back construction;
[0016] FIG. 2B partial plan view showing a tape bearing surface of
a prior art tape head module having an interleaved
construction;
[0017] FIG. 3 is a side elevation view showing a pair of the prior
art tape head modules of FIG. 1;
[0018] FIG. 4A is a partial plan view showing the tape bearing
surfaces of a pair of the prior art piggy back modules of FIG. 2A
arranged for transducing a tape;
[0019] FIG. 4B is a partial plan view showing the tape bearing
surfaces of a pair of the prior art interleaved modules of FIG. 2B
arranged for transducing a tape;
[0020] FIG. 5 is a partial plan view showing the tape bearing
surfaces of three prior art tape head modules arranged for
transducing a tape in a configuration wherein two arrays of write
transducers sandwich an array of read transducers;
[0021] FIG. 6 is a partial plan view showing the tape bearing
surface of a tape head module constructed in accordance with an
exemplary disclosed embodiment;
[0022] FIG. 7 is an enlarged view of the tape head module of FIG. 6
showing an implementation wherein the module includes arrays of
write transducer elements;
[0023] FIG. 8 is an enlarged view of the tape head module of FIG. 6
showing an implementation wherein the module includes arrays of
read transducer elements;
[0024] FIG. 9 is an enlarged view of the tape head module of FIG. 6
showing an implementation wherein the module includes arrays of
interleaved read and write transducer elements;
[0025] FIG. 10 is an enlarged view of the tape head module of FIG.
6 showing an implementation wherein the module includes arrays of
piggy backed read and write transducer elements;
[0026] FIG. 11 is a partial plan view showing the tape bearing
surfaces of two tape head modules according to FIG. 6, wherein each
module has arrays of interleaved read and write elements;
[0027] FIG. 12 is a partial plan view showing the tape bearing
surfaces of two tape head modules according to FIG. 6, wherein each
module has arrays of piggy backed read and write elements;
[0028] FIG. 13 is a partial plan view showing the tape bearing
surfaces of three tape head modules according to FIG. 6, wherein
two modules have arrays of write elements and a third module
disposed between the write element arrays has arrays of read
elements;
[0029] FIG. 14 is a partial plan view showing the tape bearing
surface of a tape head module constructed in accordance with
another exemplary disclosed embodiment;
[0030] FIG. 15 is a cross-sectional view taken along line 15-15 in
FIG. 14;
[0031] FIG. 16 is a functional block diagram showing a tape drive
data storage device adapted for use with the present invention;
and
[0032] FIG. 17 is a perspective view showing an exemplary
construction of the tape drive storage device of FIG. 16 for use
with cartridge-based tape media.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0033] The invention will now be described by way of exemplary
embodiments shown by the drawing figures (which are not necessarily
to scale), in which like reference numerals indicate like elements
in all of the several views.
[0034] Turning now to FIG. 6, a tape head 2 is designed for
transducing data on a magnetic recording tape that is subject to
tape dimensional changes. The tape head includes two or more arrays
of transducer elements having different transducer spacing
distances (center-to-center pitch) corresponding to different track
spacing distances (center-to-center pitch) to be transduced. One of
the transducer arrays 4A has nominal transducer spacing and may be
used for transducing the tape under nominal tape track spacing
conditions. Another transducer array 4B has reduced transducer
spacing and may be used for transducing the tape when the tape
track spacing is reduced due to the tape shrinkage. Still another
transducer array 4C has enlarged tape track spacing and may be used
for transducing the tape when the tape track spacing is enlarged
due to tape expansion. Alternatively, the first transducer array 4A
can be used and the tape can be stretched longitudinally to reduce
the tape track spacing closer to the nominal tape track spacing.
This is because changes in tape width are related to changes in
tape extension via Poissons ratio, which is typically 0.3-0.5 for a
flexible medium such as tape. Each of the arrays 4A, 4B and 4C
includes sixteen data transducers 6 for transducing customer data,
and a pair of servo read transducers 8 for transducing tape servo
tracks. The use of sixteen data transducers is of course arbitrary
and it will be appreciated that fewer or more data transducers
could be incorporated in each array. It should also be pointed out
that the differences in transducer spacing between the transducer
arrays 4A, 4B and 4C refers to the data transducers 6. The spacing
between the two servo transducers 8 of the transducer arrays 4A, 4B
and 4C will preferably be the same for each array. The reason for
this will be made clear below.
[0035] It will be appreciated that the nominal transducer spacing
of the transducer array 4A is arbitrary and will depend on design
preferences. As described by way of background above, a data track
spacing of 167 .mu.m is common for current generation tape heads,
and this value may be used for the nominal spacing of the data
transducers 6 of the transducer array 4A. If there are sixteen data
transducers 6 per array, the data transducers span would be
15x167=2505 .mu.m. The reduced transducer spacing distance of the
transducer array 4B and the enlarged transducer spacing distance of
the transducer array 4C may be selected according to the
anticipated shrinkage and expansion of the tape to be transduced,
respectively. This may be determined by experiment. For example, if
it is anticipated that the change in cross-track tape dimension
will be +/-0.12%, the sixteen data transducers 6 of the array 4B
can be spaced so that the data transducer span length is
2505x(1-0.0012)=2502 .mu.m, which is approximately 3 microns less
than the length of the nominal data transducer span of the array
4A. The sixteen data transducers 6 of the array 4B can be spaced so
that the data transducer span length is 2505x(1+0.0012)=2508 .mu.m,
which is approximately 3 microns more than the length of the
nominal data transducer span of the array 4A. Note that if the
0.12% change in dimension above is an anticipated worst case
condition, the spacing of the arrays 4B and 4C could be less than
the 3 micron differential above (e.g., so as to reflect an average
or mean change in dimension). It will be appreciated that the
differences in transducer spacing of arrays 4A, 4B and 4C are
microscopic in scale and are thus greatly exaggerated in FIG. 1. As
track spacing reductions become possible in the future, the
nominal, reduced and enlarged transducer spacing distances of the
arrays 4A, 4B and 4C may well become even smaller.
[0036] In the embodiment of FIG. 1, the arrays 4A, 4B and 4C are
spaced from each other in a cross-track direction. They may be
fabricated on a common substrate 10 using conventional thin film
fabrication techniques and materials. A conventional closure 12 may
be bonded to the transducer side of the substrate 10 to protect the
transducer elements from wear and to optimize the tribological
properties of the tape head 2. Electrical lead connections from the
transducer elements extend away from the reader into the plane of
the drawing sheet, and thus are not visible in FIG. 1. The
resultant structure may be referred to as a tape head module
14.
[0037] Turning now to FIGS. 7-10, the transducer arrays 4A, 4B and
4C may each include one or both of write transducer elements and
read transducer elements. FIG. 7 illustrates a configuration
wherein the data transducers 6 of the transducer arrays 4A, 4B and
4C are all write transducers. FIG. 8 illustrates a configuration
wherein the data transducers 6 of the transducer arrays 4A, 4B and
4C are all read transducers. FIG. 9 illustrates a configuration
wherein the data transducers 6 of the transducer arrays 4A, 4B and
4C are interleaved read and write transducers. FIG. 10 illustrates
a configuration the data transducers 6 of the transducer arrays 4A,
4B and 4C are piggy backed read and write transducers.
[0038] Turning now to FIGS. 11-13, the transducer arrays 4A, 4B and
4C may be arranged into various array groups 16 formed on plural
modules 14. Each array group comprises two or more arrays arranged
in a cross-track direction (as described above) or side-by-side (as
described below in connection with FIG. 14). For example, as shown
in FIG. 11, the tape head 2 may include a first array group 16A-1
on a first tape head module 14A-1 and a second array group 16A-2 on
a second tape head module 14A-2. In this two-module configuration,
the first and second array groups 16A-1 and 16A-2 each comprise
read and write transducer elements arranged in an interleaved
configuration. The array groups 16A-1 and 16A-2 are designed so
that there will be one write transducer and one read transducer
over each data track being transduced on a tape. When the tape
moves from left to right in FIG. 11, the write transducers of an
array 4A, 4B or 4C of the array group 16A-1 will write data tracks
while the read transducers of a corresponding array 4A, 4B or 4C of
the array group 16A-2 can be used to read-verify the data that was
written. The roles of the array groups are reversed when the tape
moves from right to left in FIG. 11.
[0039] Another two-module configuration is shown in FIG. 12. Here,
the tape head 2 include a first array group 16B-1 on a first tape
head module 14B-1 and a second array 16B-2 group on a second tape
head module 14B-2. In this two-module configuration, the first and
second array groups 16B-1 and 16B-2 each comprise read and write
transducer elements arranged in a piggy backed configuration. The
array groups 16B-1 and 16B-2 are designed so that there will be one
write transducer and one read transducer over each data track on a
tape. When the tape moves from left to right in FIG. 12, the write
transducers of an array 4A, 4B or 4C of the array group 16B-1 will
write data tracks while the read transducers of a corresponding
array 4A, 4B or 4C of the array group 16B-2 can be used to
read-verify the data that was written. The roles of the array
groups are reversed when the tape moves from right to left in FIG.
12.
[0040] As shown in FIG. 13, the tape head 2 may alternatively
include a first array group 16C-1 on a first tape head module
14C-1, a second array group 16C-2 on a second tape head module
14C-2, and a third array group 16C-3 on a third tape head module
14C-3. In this three-module configuration, the first and third
array groups 16C-1 and 16C-3 may comprise write transducer elements
and the second array group 16C-2 may comprise read transducer
elements. The second tape head module 14C-2 may be disposed between
the first and third tape head modules 14C-1 and 14C-3. The array
groups 16C-1, 16C-2 and 16C-3 are designed so that there will be
two write transducers and one read transducer over each data track
on a tape. When the tape moves from left to right in FIG. 13, the
write transducers of an array 4A, 4B or 4C of the array group 16C-1
will write data tracks while the read transducers of a
corresponding array 4A, 4B or 4C of the array group 16C-2 can be
used to read-verify the data that was written. When the tape moves
from right to left in FIG. 12, the write transducers of an array
4A, 4B or 4C of the array group 16C-3 will write data tracks while
the read transducers of a corresponding array 4A, 4B or 4C of the
array group 16C-2 can be used to read-verify the data that was
written.
[0041] During use of the tape head 2, data may be conveniently
written or read on a magnetic recording tape while accommodating
tape dimensional changes. Before reading or writing data, a
dimensional condition of the tape is determined. This can be
determined by streaming the tape over the nominal array 4A of the
tape head 2 and reading prerecorded servo markings on the tape. If
conventional timing-based serving is used, the servo read
transducers 8 will detect if the servo track markings are nominally
spaced depending on whether a nominal servo mark timing condition
can be achieved on both tracks. If not, a tape expansion or
contraction condition may be determined from the timing change and
the orientation of the timing servo marks. This information is used
to select one of the transducer arrays 4A, 4B or 4B for transducing
according to which of the transducer spacing distances most closely
corresponds to the tape dimensional condition.
[0042] Turning now to FIG. 14, a tape head 18 represents an
alternative to the embodiment of FIG. 6 wherein two or more arrays
of transducer elements having different transducer spacing
distances are aligned in a direction of tape motion. By way of
example only, three arrays 20A, 20B and 20C are shown, with the
array 20A utilizing a nominal transducer spacing distance, the
array 20B utilizing a reduced transducer spacing distance, and the
array 20C utilizing an enlarged transducer spacing distance. As
shown in FIG. 15, the transducer arrays 20A, 20B and 20C can be
respectively fabricated on substrate layers 22A, 22B and 22C. A
closure 24 may be bonded to the transducer side of the substrate
layer 22B. As in the case of the tape head 2, the tape head 18 can
be fabricated with write transducers, read transducers, or a
combination of both in either an interleaved or piggy backed
construction. As also described above in connection with the tape
head 2, the transducer arrays 20A, 20B and 20C of the tape head 18
can be disposed on plural modules.
[0043] Turning to FIG. 16, the inventive concepts herein described
may be embodied in a tape drive data storage device (tape drive)
100 for storing and retrieving data by a host data processing
device 102, which could be a general purpose computer of other
processing apparatus adapted for data exchange with the tape drive
100. The tape drive 100 includes plural components providing a
control and data transfer system for reading and writing host data
on a magnetic tape medium. By way of example only, those components
may conventionally include a channel adapter 104, a microprocessor
controller 106, a data buffer 108, a read/write data flow circuit
110, a motion control system 112, and a tape interface system 114
that includes a motor driver circuit 116 and a read/write head unit
118.
[0044] The microprocessor controller 106 provides overhead control
functionality for the operations of the tape drive 100. As is
conventional, the functions performed by the microprocessor
controller 106 are programmable via microcode routines (not shown)
according to desired tape drive operational characteristics. During
data write operations (with all dataflow being reversed for data
read operations), the microprocessor controller 106 activates the
channel adapter 104 to perform the required host interface protocol
for receiving an information data block. The channel adapter 104
communicates the data block to the data buffer 108 that stores the
data for subsequent read/write processing. The data buffer 108 in
turn communicates the data block received from the channel adapter
104 to the read/write dataflow circuitry 110, which formats the
device data into physically formatted data that may be recorded on
a magnetic tape medium. The read/write dataflow circuitry 110 is
responsible for executing read/write data transfer operations under
the control of the microprocessor controller 106. Formatted
physical data from the read/write data flow circuitry 110 is
communicated to the tape interface system 114. The latter includes
one or more read/write heads in the read/write head unit 118, and
drive motor components (not shown) for performing forward and
reverse movement of a tape medium 120 mounted on a supply reel 122
and a take-up reel 124. The drive components of the tape interface
system 114 are controlled by the motion control system 112 and the
motor driver circuit 116 to execute such tape movements as forward
and reverse recording and playback, rewind and other tape motion
functions. In addition, in multi-track tape drive systems, the
motion control system 112 transversely positions the read/write
heads relative to the direction of longitudinal tape movement in
order to record data in a plurality of tracks.
[0045] In most cases, as shown in FIG. 17, the tape medium 120 will
be mounted in a cartridge 126 that is inserted in the tape drive
100 via a slot 128. The tape cartridge 126 comprises a housing 130
containing the magnetic tape 120. The supply reel 122 is shown to
be mounted in the housing 130.
[0046] Accordingly, a tape head, method and tape drive have been
disclosed that are capable of accommodating temperature-induced
tape dimensional changes. While various embodiments of the
invention have been shown and described, it should be apparent that
many variations and alternative embodiments could be implemented in
accordance with the teachings herein. It is understood, therefore,
that the invention is not to be in any way limited except in
accordance with the spirit of the appended claims and their
equivalents.
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