U.S. patent application number 16/567905 was filed with the patent office on 2021-03-11 for non-interfering micro-positioning system utilizing piezoelectric elements.
The applicant listed for this patent is International Business Machines Corporation. Invention is credited to David Harper.
Application Number | 20210074330 16/567905 |
Document ID | / |
Family ID | 1000004338001 |
Filed Date | 2021-03-11 |
United States Patent
Application |
20210074330 |
Kind Code |
A1 |
Harper; David |
March 11, 2021 |
NON-INTERFERING MICRO-POSITIONING SYSTEM UTILIZING PIEZOELECTRIC
ELEMENTS
Abstract
Implementation of a non-interfering micro-positioning device,
for a tape drive write/read head module assembly utilizing
piezoelectric elements, by generating at least two flexure
brackets. The at least two flexure brackets may include the
piezoelectric elements. Affixing at least one flexure bracket to a
first side of the write/read head module assembly. Affixing at
least one other flexure bracket to a second side of the write/read
head module assembly.
Inventors: |
Harper; David; (Vail,
AZ) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
International Business Machines Corporation |
Armonk |
NY |
US |
|
|
Family ID: |
1000004338001 |
Appl. No.: |
16/567905 |
Filed: |
September 11, 2019 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G11B 21/02 20130101;
G11B 5/5504 20130101; G11B 5/584 20130101; G11B 5/4893 20130101;
G11B 5/58 20130101; G11B 33/124 20130101; G11B 5/55 20130101; G11B
5/592 20130101; H01L 41/09 20130101 |
International
Class: |
G11B 33/12 20060101
G11B033/12; H01L 41/09 20060101 H01L041/09; G11B 21/02 20060101
G11B021/02 |
Claims
1. A method for implementing a non-interfering micro-positioning
device for a tape drive write/read head module assembly utilizing
piezoelectric elements, the method comprising: generating at least
two flexure brackets, wherein the at least two flexure brackets
include the piezoelectric elements, the piezoelectric elements
attached to each of the at least two flexure brackets in a
longitudinal orientation when affixed to a side of the write/read
head module assembly; affixing at least one flexure bracket to a
first side of the write/read head module assembly; and affixing at
least one other flexure bracket to a second side of the write/read
head module assembly.
2. The method of claim 1, wherein the at least two flexures include
a flexure for each of a top portion and a bottom portion of the
first side of the write/read head module assembly and the second
side of the write/read head module assembly.
3. The method of claim 1, wherein the write/read head module
assembly includes one or more head cables and a mechanical ground
module for the at least two flexures to shift on.
4. The method of claim 1, further comprising: energizing the at
least two flexure brackets in order to shift the write/read head
module assembly in a particular direction.
5. The method of claim 4, wherein shifting the write/read head
module assembly in the particular direction is done in a
corresponding direction as a placement of the mechanical
ground.
6. The method of claim 4, wherein energizing the at least two
flexure brackets in order to shift the write/read head module
assembly in the particular direction includes energizing the
piezoelectric elements of the at least two flexure brackets in
concert.
7. The method of claim 6, wherein energizing the at least two
flexure brackets in concert causes the expansion of the at least
two flexure brackets.
8. The method of claim 6, wherein energizing the at least two
flexure brackets concert causes the contraction of the at least two
flexure brackets.
9. A non-interfering micro-positioning system for a tape drive
write/read head module assembly utilizing piezoelectric elements,
the system comprising: at least two flexure brackets, wherein the
at least two flexure brackets include the piezoelectric elements,
the piezoelectric elements attached to each of the at least two
flexure brackets in a longitudinal orientation when affixed to a
side of the write/read head module assembly; at least one flexure
bracket affixed to a first side of the write/read head module
assembly; and at least one other flexure bracket affixed to a
second side of the write/read head module assembly.
10. The system of claim 9, wherein the at least two flexures
include a flexure for each of a top portion and a bottom portion of
the first side of the write/read head module assembly and the
second side of the write/read head module assembly.
11. The system of claim 9, wherein the write/read head module
assembly includes one or more head cables and a mechanical ground
module for the at least two flexures to shift on.
12. The system of claim 9, wherein the at least two flexure
brackets are energized in order to shift the write/read head module
assembly in a particular direction.
13. The system of claim 12, wherein shifting the write/read head
module assembly in the particular direction is done in a
corresponding direction as a placement of the mechanical
ground.
14. The system of claim 12, wherein energizing the at least two
flexure brackets in order to shift the write/read head module
assembly in the particular direction includes energizing the
piezoelectric elements of the at least two flexure brackets in
concert.
15. The system of claim 14, wherein energizing the at least two
flexure brackets in concert causes the expansion of the at least
two flexure brackets.
16. The system of claim 14, wherein energizing the at least two
flexure brackets in concert causes the contraction of the at least
two flexure brackets.
Description
BACKGROUND
[0001] The present disclosure relates generally to the field of
tape media data storage, and more specifically to increasing the
precise motion of a tape write/read head during tape
operations.
[0002] The general goal in the tape storage industry is to be able
to store higher amounts of data with each subsequent generation of
tape cartridge and drive. In order to do this, the number of data
tracks for a given width of tape keeps increasing. As the number of
tracks increases, the size of the tracks is reduced and the
requirements for increased precision of the dynamic placement of
the write/read head during tape operations correspondingly
increases.
[0003] Further, traditional piezoelectric materials are materials
that produce an electric charge when mechanical stresses are
applied. However, some piezoelectric materials are able to have a
reverse effect where, when an electric charge (e.g., voltage,
current) is applied, they mechanically expand or contract.
SUMMARY
[0004] Embodiments of the present disclosure include a method for
implementing a non-interfering micro-positioning device for a tape
drive write/read head module assembly utilizing piezoelectric
elements. At least two flexure brackets may be generated. The at
least two flexure brackets may include piezoelectric elements. At
least one flexure bracket may be affixed to a first side of the
write/read head module assembly. At least one other flexure bracket
may be affixed to a second side of the write/read head module
assembly.
[0005] The above summary is not intended to describe each
illustrated embodiment or every implementation of the present
disclosure.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] The drawings included in the present disclosure are
incorporated into, and form part of, the specification. They
illustrate embodiments of the present disclosure and, along with
the description, serve to explain the principles of the disclosure.
The drawings are only illustrative of certain embodiments and do
not limit the disclosure.
[0007] FIG. 1A depicts a top-down, front view of a flexure bracket
with a bonding surface directed outward, in accordance with
embodiments of the present disclosure.
[0008] FIG. 1B depicts a top-down, front view of a flexure bracket
with a bonding surface directed inward, in accordance with
embodiments of the present disclosure.
[0009] FIG. 2 depicts a top-down, front view of a write/read head
module assembly being affixed with multiple flexure brackets, in
accordance with embodiments of the present disclosure.
[0010] FIG. 3 depicts a top-down, front view of a write/read head
module assembly affixed with multiple bonded flexure brackets, in
accordance with embodiments of the present disclosure.
[0011] FIG. 4 depicts a top-down, front view of a traditional
write/read tape head being mounted to moveable beams that are
connected to a center beam that is mounted to a traditional fine
motion voice coil motor assembly, in accordance with embodiments of
the present disclosure.
[0012] FIG. 5 depicts a top-down, front view of semi-flexible
structures with piezoelectric stacks bonded to either end of a
write/read tape head, in accordance with embodiments of the present
disclosure.
[0013] FIG. 6 depicts a top-down, front view of moveable beams that
are augmented for bonding to semi-flexible structures and that are
connected to a center beam that is mounted to a fine motion voice
coil motor assembly, in accordance with embodiments of the present
disclosure.
[0014] FIG. 7 depicts a top-down, front view of semi-flexible
structures bonding to moveable beams, in accordance with
embodiments of the present disclosure.
[0015] FIG. 8 depicts a top-down, front view of a tape guide roller
bearing affixed to a rigid support base, in accordance with
embodiments of the present disclosure.
[0016] FIG. 9 depicts a top-down, front view of a tape deck base,
in accordance with embodiments of the present disclosure.
[0017] FIG. 10 depicts a top-down, front view of a piezoelectric
stack, in accordance with embodiments of the present
disclosure.
[0018] FIG. 11 depicts a top-down, front view of a lower end
support bracket, in accordance with embodiments of the present
disclosure.
[0019] FIG. 12 depicts a top-down, front view of an assembly of a
dynamic tape guide bearing tilt mechanism, in accordance with
embodiments of the present disclosure.
[0020] While the embodiments described herein are amenable to
various modifications and alternative forms, specifics thereof have
been shown by way of example in the drawings and will be described
in detail. It should be understood, however, that the particular
embodiments described are not to be taken in a limiting sense. On
the contrary, the intention is to cover all modifications,
equivalents, and alternatives falling within the spirit and scope
of the disclosure.
DETAILED DESCRIPTION
[0021] Aspects of the present disclosure relates generally to the
field of tape media data storage, and more specifically to
increasing the precise motion of a tape during tape operations. It
should be noted that a "tape" is defined as a flexible magnetic
tape medium. While the present disclosure is not necessarily
limited to such applications, various aspects of the disclosure may
be appreciated through a discussion of various examples using this
context.
[0022] Tape drives generally consist of a flexible magnetic tape
medium that is transported, via reel motors, from one hub to
another, and which has a set width. The magnetic tape medium is
typically stored in a tape cartridge that can be removed and stored
separately from a tape drive. Data is stored on the tape media in a
controlled manner that allows for the retrieval of data at a later
time. Data is generally stored on data tracks at predefined widths
on the width of the flexible magnetic tape medium.
[0023] The general goal in the tape storage industry is to store
greater amounts of data with each subsequent generation of tape
cartridge and tape drive without increasing the width of the
flexible magnetic tape medium. Accordingly, there is an ongoing
need to increase the number of data tracks for the given width of
the flexible magnetic tape medium (e.g., decrease the width/spacing
between the data tracks). Further, there is an ongoing need to have
increased control of the motion of the tape as generations
progress. Accordingly, as the number of data tracks increases, the
size of the data tracks is reduced and the requirements for
increased precision of the dynamic placement of the write/read head
module assembly during tape operations is needed as generations
progress. Typically, the requirement to improve the track following
operation requires a reduction in the position error signal (PES).
PES reduction can be achieved by improving the performance of the
write/read head actuator mechanism.
[0024] One method for improving the dynamic track following
capability is to use a micro-actuator in addition to the
traditional write/read head following actuator that is typically
implemented in tape drive systems. Implementation of a
micro-actuator allows for enhanced micro-positioning of the
write/read head as a secondary stage used during track following.
The method described hereinbelow in more detail demonstrates such a
system that can be used in tandem with the traditional track
following system, and which does so in a compact manner. It is
noted that due to the unique nature of the described design, the
micro-actuator motion is amplified to allow for increased motion of
the write/read head.
[0025] Accordingly, the described method/system is suitable for
ultra-fine movements, such as those found in piezoelectric stacks,
which could then be converted into larger movements. For example,
due to the nature of the proposed semi-flexible bracket, the motion
of a piezoelectric stack with one micrometer of stack expansion,
would be converted into two micrometers of track follow motion at
the write/read head. This increase in gain allows for a wider range
of motion to be covered, but still use ultra-fine actuator
motion.
[0026] Another method for improving the dynamic track following
capability is to use a micro-actuator consisting of a series of
piezoelectric elements in addition to the traditional write/read
head module assembly following actuator typically implemented in
tape drive systems. Implementation of piezoelectric elements can
allow for enhanced micro-positioning of the write/read head module
assembly as a secondary stage used during track following. The
method described hereinbelow with more detail demonstrates such a
system that can be used in tandem with the traditional track
following system, but does so without interfering with the
write/read head cables that need to be placed on the actuator
assembly without interference. This is in contrast to the
traditional approach where the head cables, that connect the head
to a main logic card in order to transfer data, must be attached to
the write/read head module assembly prior to being inserted into
the actuator assembly, which can therefore be subject to mechanical
interference.
[0027] By implementing piezoelectric elements on a series of
flexures (e.g., brackets, elements engineered to be compliant
within a specific degree of physical adjustment, etc.), which could
be made by etching, stamping, and/or bending, a micro-actuator
system can be implemented without cable interference. The
write/read head module assembly would then be bonded to the movable
surfaces of the flexures that can be moved by activation of the
piezoelectric elements. The flexures may be mounted in (e.g., on,
to, etc.) the outer corners/edges/sides/etc. of the write/read head
module assembly so that they may move with the traditional fine
track following actuator, typically driven by a voice coil motor
(VCM).
[0028] Further, it is also typical, that tape motion is controlled
by using roller guide bearings that need to be precisely aligned
with respect to a tape drive and its datums. Misalignment in the
tilt of the rollers can cause increased error in the track
following functions while the write/read tape head is being
positioned to accurately follow the tape tracks. As part of the
track following procedures, it is also desirable to minimize tape
tilt, also known as `tape skew.`
[0029] Tape skew can occur periodically or randomly as a tape moves
from one reel to another reel. A small amount of offset can be
enough to cause the tape to steer into other moving components and
cause higher error during track following (e.g. position error
signal increases). In ordinary embodiments, tape skew may be
minimized by implementing an actuator at a write/read head to
compensate for the tape skew. However, proposed in this disclosure
is another method to control tape skew so that the head actuator
does not need to be rotated to match the tilt of the tape during
operation(s). A piezoelectric stack is implemented that can
precisely, and dynamically, tilt a roller guide bearing to reduce
and/or eliminate the effects of tape skew.
[0030] By strategically locating a piezoelectric stack under a tape
path guide roller bearing structure, and by causing the
piezoelectric stack to expand or contract, the tilt of a roller can
be modified, thus reducing, or eliminating, the amount of tape skew
encountered during operation. The advantage of using such a
technique is that it will reduce complexity of the write/read
actuator that exists in some production tape products in the
applicable market.
[0031] Using a piezoelectric stack to modify the amount of tilt of
the roller bearing will help to reduce the overall track following
error with a simplified head actuator system. By modifying the
supporting bracket that holds the roller bearing, the gain, or
amplification, of the amount of tilt for a given amount of
piezoelectric stack expansion or contraction can be adjusted as
desired, which, will again reduce, or eliminate, the effects of
tape skew.
[0032] Example embodiments will now be described more fully herein
with reference to the accompanying drawings, in which example
embodiments are shown. This disclosure may, however, be embodied in
many different forms and should not be construed as limited to the
example embodiments set forth herein. Rather, these example
embodiments are provided so that this disclosure will be thorough
and complete and will convey the scope of this disclosure to those
skilled in the art. In the description, details of well-known
features and techniques may be omitted to avoid unnecessarily
obscuring the presented embodiments.
[0033] For purposes of the description hereinafter, terms such as
"upper," "lower," "right," "left," "vertical," "horizontal," "top,"
"bottom," and derivatives thereof shall relate to the disclosed
structures and methods, as oriented in the drawing figures. Terms
such as "above," "overlying," "atop," "on top," "positioned on," or
"positioned atop" mean that a first element, such as a first
structure, is present on a second element, such as a second
structure, wherein intervening elements, such as an interface
structure, may be present between the first element and the second
element. The term "direct contact" means that a first element, such
as a first structure, and a second element, such as a second
structure, are connected without any intermediary conducting,
insulating, or semiconductor layers at the interface of the two
elements. The term substantially, or substantially similar, refers
to instances in which the difference in length, height, or
orientation convey no practical difference between the definite
recitation (e.g. the phrase sans the substantially similar term),
and the substantially similar variations. In one embodiment,
substantial (and its derivatives) denote a difference by a
generally accepted engineering or manufacturing tolerance for
similar devices, up to, for example, 10% deviation in value or
10.degree. deviation in angle.
[0034] In the interest of not obscuring the presentation of
embodiments of the present disclosure, in the following detailed
description, some processing steps or operations that are known in
the art may have been combined together for presentation and for
illustration purposes and in some instances, may have not been
described in detail. In other instances, some processing steps or
operations that are known in the art may not be described at all.
It should be understood that the following description is rather
focused on the distinctive features or elements of various
embodiments of the present disclosure. Additionally noted is that
like reference numerals are used to designate like parts in the
accompanying drawings.
[0035] Turning now to FIG. 1A, depicted is a top-down, front view
of a flexure bracket 100A with a bonding surface 102 directed
outward, in accordance with embodiments of the present disclosure.
In some embodiments, the flexure bracket 100A is generated via the
processes described above (e.g., etching, stamping, bending, etc.).
The flexure bracket 100A may be comprised of any malleable material
(e.g., metal, polymer, etc.) that would not interfere with a VCM or
other head assembly components. In some embodiments, the flexure
bracket 100A includes a piezoelectric element 106.
[0036] The flexure bracket 100A includes a mechanical ground 104,
which, for the purposes of this disclosure is the bottom portion of
the flexure bracket 100A. The mechanical ground 104 prevents the
piezoelectric element 106 from expanding or contracting in dual
directions. That is, the mechanical ground 104 allows the
piezoelectric element 106 to direct all of the movement in one
direction, either away from the mechanical ground 104 (e.g., due to
the piezoelectric element 106 expanding), or toward the mechanical
ground 104 (e.g., due to the piezoelectric element 106
contracting). It is contemplated that the flexure bracket 100A will
be affixed to a first side of a write/read head module assembly (to
be discussed more fully in regard to FIGS. 2 and 3) via the bonding
surface 102.
[0037] Referring now to FIG. 1B, depicted is a top-down, front view
of a flexure bracket 100B with a bonding surface 102 directed
inward, in accordance with embodiments of the present disclosure.
The flexure bracket 100B may be the same, or substantially similar
to, the flexure bracket 100A of FIG. 1A and/or may comprise the
same components (e.g., bonding surface 102, mechanical ground 104,
and piezoelectric element 106) as the flexure bracket 100A of the
FIG. 1A.
[0038] It is contemplated that the flexure bracket 100B will be
affixed to a second side of a write/read head module assembly via
the bonding surface 102. In some embodiments, the flexure bracket
100B is affixed on the write/read head module assembly opposite the
flexure bracket 100A (e.g., the second side of the write/read head
module assembly is an opposite face of the write/read head module
assembly).
[0039] In some embodiments, the flexure bracket 100B is affixed to
the write/read head module assembly above or below the flexure
bracket 100A (e.g., the second side of the write/read head module
assembly is the opposite direction of the same face of the
write/read head module assembly).
[0040] Referring now to FIG. 2, depicted is a top-down, front view
of a write/read head module assembly 208 being affixed with
multiple (e.g., at least two) flexure brackets 200A-D, in
accordance with embodiments of the present disclosure. The flexure
brackets 200A-D may be the same as, or substantially similar to,
the flexure brackets 100A and 100B of FIGS. 1A and 1B,
respectively. In some embodiments, each of the flexure brackets
200A-D includes a bonding surface 202, a mechanical ground 204, and
piezoelectric element 206.
[0041] For continuing purposes of this description of FIG. 2, it is
noted that head cables 210A and 210B are partially shown to
indicate in which direction the write/read head module 208 will
travel when operational. Further, a traditional VCM is not shown,
but all four of the flexure brackets 200A-D are to be affixed
(e.g., bonded, mounted, etc.) to the traditional VCM at the outer
corner regions of the write/read head module assembly 208.
[0042] It is further noted that the moveable beam of the VCM
assembly would normally have been bonded directly to the write/read
head module assembly 208, but instead the VCM moveable beam is
bonded to the four flexure brackets 200A-D utilizing another
bonding surface of the flexure brackets 200A-D that is not shown.
The write/read head module assembly 208 is then bonded and
supported by the four flexure brackets 200A-D.
[0043] In some embodiments, as noted by the use of the flexure
brackets 200A-D, there is a flexure (e.g., 200A-D) for each of a
top portion and a bottom portion of the first side of the
write/read head module assembly and the second side of the
write/read head module assembly. For instance the flexure bracket
200A will be affixed, as denoted by the dashed arrow, to a top
portion of the first side of the write/read head module assembly
208 and the flexure bracket 200D will be affixed, as denoted by the
dashed arrow, to a bottom portion of the first side of the
write/read head module assembly 208.
[0044] Further, flexure bracket 200B will be affixed, as denoted by
the dashed arrow, to a top portion of the second side of the
write/read head module assembly 208 and flexure bracket 200C will
be affixed, as denoted by the dashed arrow, to a bottom portion of
the second side of the write/read head module assembly 208.
[0045] In some embodiments, the head cables 210A and 210B and the
mechanical grounds 204 are used for the write/read head module
assembly 208 to shift on (as depicted by the directional arrows
found in the piezoelectric elements 206 of the flexure brackets
200A-D and the write/read head module assembly 208) in a particular
direction.
[0046] In some embodiments, shifting the write/read head module
assembly 208 in the particular direction includes energizing the
piezoelectric elements 206 of the flexure brackets 200A-D in order
to shift the write/read head module assembly 208 in the particular
direction (e.g., up, down, left, right, etc. as denoted by the
direction arrow illustrated in the write/read head module assembly
208).
[0047] In some embodiments, energizing the piezoelectric elements
206 of the flexure brackets 200A-D in order to shift the write/read
head module assembly 208 in the particular direction includes
energizing the piezoelectric elements 206 of the flexure brackets
200A-D in concert (e.g., unison). For instance, energizing the
piezoelectric elements 206 of the flexure brackets 200A-D with a
negative polarity will cause their piezoelectric elements 206 to
contract and move the write/read head module assembly 208 downward,
while energizing the piezoelectric elements 206 of the flexure
brackets 200A-D with a positive polarity will cause their
piezoelectric elements 206 to expand and move the write/read head
module assembly 208 upward, or vice-a-versa (e.g., negative
polarity causes expansion and positive polarity causes
contraction).
[0048] In some embodiments, shifting the write/read head module
assembly 208 in the particular direction is done in a corresponding
direction as a placement of the mechanical grounds 204 of the
flexure brackets 200A-D. That is, since the mechanical grounds 204
prevent the movement of the piezoelectric elements 206 in a
particular direction depending on whether the piezoelectric
elements 206 are expanding or contracting, the write/read head
module assembly 208 is forced to move in a direction dependent on
the mechanical grounds 204.
[0049] For example, if each of the piezoelectric elements 206
contracts, they will pull toward the mechanical grounds 204 and
thus pull the write/read head module assembly 208 downward.
Whereas, if each of the piezoelectric elements 206 expands, they
will push away from the mechanical grounds 204 and thus push the
write/read head module assembly 208 upward.
[0050] In some embodiments, the positioning of the bonding surfaces
202 of the flexure brackets 200C and 200D may be inverted from
those of the flexure brackets 200A and 200B. That is, the
mechanical grounds 204 of flexure brackets 200C and 200D may be
pointed upward instead of as downward as depicted. This would
result in the piezoelectric elements 206 of the flexure brackets
200C and 200D needing to be energized with an opposing polarity to
that of the piezoelectric elements 206 of the flexure brackets 200A
and 200B to have the flexure brackets 200A-D work in concert and
shift the write/read head module assembly 208.
[0051] For example, if the piezoelectric elements 206 of the
flexure brackets 200A and 200B are energized with a negative
polarity, the piezoelectric elements 206 of the flexure brackets
200C and 200D would need be energized with a positive polarity in
order to shift the write/read head module assembly 208 downward.
That is because the piezoelectric elements 206 of the flexure
brackets 200A and 200B would contract, pulling downward toward
their respective mechanical grounds 204 of the flexure brackets
200A and 200B, while, in concert, the piezoelectric elements 206 of
the flexure brackets 200C and 200D would expend, pushing downward
from the their respective mechanical grounds 204 of the flexure
brackets 200C and 200D. Thus generating a net shift downward, or
vice-a-versa.
[0052] It is noted that the micro-movements of the piezoelectric
elements 206 are within the range of microns and allow for the
precise movement, positioning, and/or repositioning of the
write/read head module assembly 208, which allows for a magnetic
tape media to be more densely compacted with data tracks, as the
write/read head module assembly 208 can now position itself to
write/read the compacted data tracks.
[0053] Referring now to FIG. 3, depicted is a top-down, front view
of a write/read head module assembly 308 affixed with multiple
bonded flexure brackets 300A-D, in accordance with embodiments of
the present disclosure. The flexure brackets 300A-D may be the same
as, or substantially similar to, the flexure brackets 100A, 100B,
or 200A-D of FIGS. 1A, 1B, and 2, respectively. In some
embodiments, each of the flexure brackets 300A-D includes a bonding
surface 302, a mechanical ground 304, and piezoelectric element
306. Further, the write/read head module assembly 308 may be the
same, or substantially similar, write/read head module assembly as
the write/read head module assembly 208 of FIG. 2.
[0054] FIG. 3, denotes the bonding of the write/read head module
assembly 308 to each of the flexure brackets 300A-D via the bonding
surfaces 302. The flexure brackets 300A-D, although not shown, may
additionally be bonded to a VCM moveable beam. One having ordinary
skill in the art of tape storage would recognize from this
disclosure that a VCM is a needed part and not needed to be fully
detailed for understanding. Further, one having ordinary skill in
the art would recognize that the addition of the disclosed flexure
brackets 300A-D to the write/read head module assembly 308 would
substantially increase the precision of the write/read head module
assembly 308 to position itself during data storage interactions
(e.g., reading/writing).
[0055] Turning now to FIG. 4, depicted is a top-down, front view of
a traditional write/read tape head 420 being mounted (e.g., bonded,
connected, etc.) to moveable beams 406, which have a same length,
and which are connected to a center beam 404 that is mounted to a
traditional fine motion voice coil motor assembly 402, in
accordance with embodiments of the present disclosure. It is noted
that one having ordinary skill in the art would recognize that the
voice coil motor assembly 402 would incorporate head cables, but
for ease of viewing they are left out of FIG. 4 (and the subsequent
FIGS. 5-7).
[0056] FIG. 4 is included to indicate that traditionally, the
moveable beams 406 of the voice coil motor assembly 402 would
normally have been bonded directly to the traditional write/read
tape head 420. The traditional bonding of the traditional
write/read head 420 to the moveable beams 406 only allows for
select fine-motion movements. Whereas to be discussed below in
regard to FIGS. 5-7, the present disclosure describes a method for
a system that can amplify (e.g., increase) the fine-motion
movements if needed to improve performance of a write/read tape
head.
[0057] Referring now to FIG. 5, depicted is a top-down, front view
of semi-flexible structures 502, with piezoelectric stacks 508,
that are bonded to either end of a write/read tape head 520, in
accordance with embodiments of the present disclosure. In some
embodiments, the semi-flexible structures 502 (e.g., a first
semi-flexible structure and a second semi-flexible structure) are
generated. In some embodiments, the semi-flexible structures 502
are generate by bending, notching, etc. a malleable metal, such as,
stainless steel.
[0058] In some embodiments, one of the semi-flexible structures 502
is then bonded at the bond point 506 to a first end of the
write/read tape head 520. The other semi-flexible structure 502 is
then bonded to a second (e.g., opposite) end of the write/read tape
head 520 (a bond point is not shown for the other semi-flexible
structure).
[0059] In some embodiments, both the semi-flexible structures 502
are J-shaped. The J-shape is a curved shape with two opposite
sides. A first side of the J-shape has a lower height than a second
side of the J-shape. As depicted the first side of the J-shape of
the semi-flexible structures 502 include beam bonding surfaces 510,
which will bond to the moveable beams 606 of FIG. 6 that is
discussed below in more detail.
[0060] In some embodiments, both of the semi-flexible structures
502 have multiple concavities that increase flexibility of the
semi-flexible structures 502 and increase amplification of
micro-actuator motion. In some embodiments, the amplification of
micro-actuation is achieved by the ratio of L2/L1.
[0061] In some embodiments, the second side (e.g., the longer side
of the J-shape) of one of the (e.g., first) semi-flexible
structures 502 is bonded (e.g., as depicted by the bond point 506)
to the first end of the write/read tape head 520. The second side
of the other (e.g., second) semi-flexible structure 502 is bonded
to the second end of the write/read tape head 520.
[0062] In some embodiments, both semi-flexible structures 502
include bonded piezoelectric stacks 508. The bonded piezoelectric
stacks 508 are located between the first side of the J-shape and
the second side of the J-shape of the semi-flexible structures 502,
respectively.
[0063] The bonded piezoelectric stacks 508 are respectively
positioned to have a top portion flush with an end portion of the
first side (e.g., the side with lower height and the beam bonding
surfaces 510) of the J-shape of each of the semi-flexible
structures 502. The bonded piezoelectric stacks 508 extend directly
across from the first side of the J-shape to a corresponding
internal portion of the second side of the J-shape of each of the
semi-flexible structures 502.
[0064] Referring now to FIG. 6, depicted is a top-down, front view
of moveable beams 606 that are augmented for bonding, as depicted
by semi-flexible structure bond points 610, to semi-flexible
structures (not shown, but is discussed more fully in regard to
FIG. 7 below) and that are connected to a center beam 604 that is
mounted to a fine motion voice coil motor assembly 602, in
accordance with embodiments of the present disclosure. In some
embodiments, the components of FIG. 6 are the same, or
substantially similar, to the components found within FIG. 4.
[0065] In some embodiments, the moveable beams 606 are the moveable
beams 406 from FIG. 4, but the moveable beams 406 have been
augmented to include the semi-flexible structure bond points 610.
In some embodiments, a first side of the moveable beams 606 with
the semi-flexible structure bond points 610 have a length that is
less than the length of a second side of the moveable beams 606.
This first side of the moveable beams 606 may be shorter than the
second side of the moveable beams 606 in order to account for the
bonding of the semi-flexible structure that will be attached. In
some embodiments, the first side of the J-shape of the
semi-flexible structure with the beam bonding surface may be the
length of what would be remaining of the second side of the
moveable beams 606, e.g., the first side of the J-shape bonded to
the first side of the moveable beams 606 would equal the full
length of the second side of the moveable beams 606. In some
embodiments, both sides of the moveable beams 606 may have the same
length regardless of the semi-flexible structure bond points
610.
[0066] Referring now to FIG. 7, depicted is a top-down, front view
of semi-flexible structures 502 bonding to moveable beams 606 via
beam bonding surfaces 510 to semi-flexible structure bonding points
610, in accordance with embodiments of the present disclosure. It
is noted that FIG. 7 illustrates the components found in FIGS. 5
and 6.
[0067] In some embodiments, the beam bonding surfaces 510 are
bonded to the semi-flexible structure bonding points 610, thus
connecting the apparatuses found in FIGS. 5 and 6. The resulting
structure is the write/read tape head 520 being functionally
attached to the fine motion voice coil motor assembly 602, which
now can have amplified fine motion due to the semi-flexible
structures 502.
[0068] It is noted that compared to traditional methods where the
moveable beams 606 of the fine motion voice coil motor assembly 602
would have been bonded directly to the write/read tape head 520,
that the moveable beam 606 are bonded to the semi-flexible
structures 502. The write/read head 520 is then bonded via bond
point 506 and supported by the semi-flexible structures 502.
[0069] The semi-flexible structures 502 move, in unison, driven by
the fine motion voice coil motor assembly 602. Within each
semi-flexible structure 502, as discussed previously, the
piezoelectric stacks 508, or another micro-actuator, is positioned.
It is noted that the present disclosure is not to be limited to the
piezoelectric stacks 508 as other compact micro-actuator systems
could be used. Micro-actuation is accomplished by the expansion
and/or contraction motion of both piezoelectric stacks 508 acting
in unison. When activated both expand and/or contract to amplify
the motion of the write/read head 520. In some embodiments, the
exact polarity will be determined by the specific orientation of
the brackets as they could be oriented in the same fashion or
opposing fashion, as shown with by the shorter end of the J-shape
of the semi-flexible structures 502 facing inward. In such a case,
opposing polarity would be needed to motion the write/read head 520
in a same direction.
[0070] In some embodiments, since the write/read head 520 is
floating, or has clearance all around all other surfaces of the
center beam 604 and the moveable beams 606, the write/read head 520
moves in a relative fine track following motion with respect to the
center beam 604, the moveable beams 606, and the fine motion voice
coil motor assembly 602.
[0071] It is further noted that the bonding in the present
disclosure is between the beam bonding surfaces 510 and the
semi-flexible structure bond points 610, and that there is no other
bond between the moveable beams 606 and the write/read head 520
(which allows for the "floating" nature and available clearance of
the write/read head 520).
[0072] In some embodiments, the fine motion voice coil motor
assembly 602 is activated. The activation of the fine motion voice
coil motor assembly 602 may cause the semi-flexible structures 502
to move, in unison, in a same direction (e.g., up, down, in-plane,
out-of-plane, etc.).
[0073] In some embodiments, the semi-flexible structures 502 may
move in unison due to their connection to the moveable beams 606,
which begin to move due to activation of the fine motion voice coil
motor assembly 602.
[0074] In some embodiments, the semi-flexible structures 502 may
move in unison due to the activating of the piezoelectric stacks
508, as the piezoelectric stacks 508 react to the activation of the
fine motion voice coil motor assembly 602 that causes the
semi-flexible structures 502 to apply a stress to the piezoelectric
stacks 508 that in turn makes the piezoelectric stacks 508 to
either expand or contract. In some embodiments, the piezoelectric
stacks 508 activate to amplify the motion of the write/read head
520.
[0075] Turning now to FIG. 8, depicted is a top-down, front view of
a tape guide roller bearing 802 affixed to a rigid support base
808, in accordance with embodiments of the present disclosure. In
some embodiments, the rigid support base 808 includes a rigid
support shaft 806 that is in the center of the rigid support base
808. In some embodiments, the tape guide roller bearing 802 is
affixed to the rigid support base 808 via the rigid support shaft
806. The tape guide roller bearing 802 may be positioned around the
rigid support shaft 806 and rotate in either a clockwise or
counter-clockwise direction around/on the rigid support shaft 806.
The rotation of the tape guide roller bearing 802 may move a tape
804 in whichever direction the tape guide roller bearing 802 is
rotating.
[0076] In some embodiments, the tape guide roller bearing 802 may
have a tape skew (e.g., tilt) that pushes the tape guide roller
bearing 802 in either a left, or right direction, that is
off-center from where the tape guide roller bearing 802 should be
positioned. In some embodiments, the tape guide roller bearing 802
may have a tilt pitch that pushes the tape guide roller bearing 802
either into, or away from, the tape 804.
[0077] Referring now to FIG. 9, depicted is a top-down, front view
of a tape deck base 918, in accordance with embodiments of the
present disclosure. In some embodiments, the tape deck base 918
includes three openings 912, 914, and 916. The first opening 912 is
for a first jack screw (e.g., jack set screw 1206) to be placed
through that will secure the rigid support base 808 of FIG. 8, and
which will be discussed more fully in regard to FIG. 12.
[0078] The second opening 914 is for a center screw (1204, which is
discussed in fuller detail below in regard to FIG. 12) that
attaches to the rigid support shaft 806 or the rigid support base
808, or both of FIG. 8, and again, which will be discussed more
fully in regard to FIG. 12. The third opening 916 is for a second
jack screw to be placed through that additionally secures the rigid
support based 808 to the tape deck base 918, however, as will be
discussed more fully in regard to FIG. 12, the third opening 916
may have the second jack screw removed and replaced with a
piezoelectric stack (e.g., 1022 of FIG. 10).
[0079] In some embodiments, the tape deck base 918 includes a tape
deck post 910 that juts upward from the tape deck base 918 and that
will insert into an adjoining concave opening (not shown) in the
rigid support base 808. The tape deck post 910 provides added tilt
pitch and skew protections by being a permanently affixed structure
that can help withstand the motions of the tape guide roller
bearing 802 during tape operations.
[0080] Referring now to FIG. 10, depicted is a top-down, front view
of a piezoelectric stack 1022, in accordance with embodiments of
the present disclosure. In some embodiments, the piezoelectric
stack 1022 includes a support rod 1020 that is attached to a
top/upper portion of the piezoelectric stack 1022. In some
embodiments, the piezoelectric stack 1022 includes wires 1024 which
can direct an electric charge to the piezoelectric stack 1022,
which will in turn cause the piezoelectric stack 1022 to either
expand or contract (e.g., with the addition or removal of the
charge).
[0081] Referring now to FIG. 11, depicted is a top-down, front view
of a lower end support bracket 1126, in accordance with embodiments
of the present disclosure. In some embodiments, the lower end
support bracket 1126 includes two connecting screw openings 1128
and 1130 and a piezoelectric stack lip 1132. The piezoelectric
stack lip 1132, as discussed more below in regard to FIG. 12, may
be used to cup around a bottom portion of the piezoelectric stack
1022 of FIG. 10 and help secure and stabilize the piezoelectric
stack 1022.
[0082] Referring now to FIG. 12, depicted is a top-down, front view
of an assembly of a dynamic tape guide bearing tilt mechanism 1200,
in accordance with embodiments of the present disclosure. In some
embodiments, the assembly of the dynamic tape guide bearing tilt
mechanism 1200 includes the use of each, or a substantial portion,
of the components described in regard to FIGS. 8-11. In some
embodiments, the assembly of the dynamic tape guide bearing tilt
mechanism 1200 further includes the addition of a jack set screw
1206, a center screw 1208, and a Belleville spring washer 1202.
[0083] In some embodiments, the assembly of the dynamic tape guide
bearing tilt mechanism 1200 begins with a bottom portion of the
rigid support base 808 attached to a top portion of the tape deck
base 918 via the tape deck post 910 being inserted into a
corresponding adjoining concave opening (not shown) in the rigid
support base 808, the jack set screw 1206 inserted through the
first opening 912, the center screw 1204 inserted through both an
opening in the Belleville spring washer 1202 and the second opening
914, and a second jack screw (not shown) inserted through the third
opening 916. It is noted that each screw (1206, 1204, and the
second jack screw) has a corresponding opening in the bottom
portion of the rigid support base 808 to which they secure into. It
is further noted that the Belleville spring washer 1202 is not
inside the tape deck base 918 but is below the tape deck base 918
and is shown for ease of understanding.
[0084] The assembly of the dynamic tape guide bearing tilt
mechanism 1200 may then proceed by removing the second jack screw
from securing the tape deck base 918 to the rigid support base 808
via the third opening 916. In some embodiments, to replace the
second jack screw, the piezoelectric stack 1022 is inserted through
the third opening 916 and the support rod 1020 now protrudes into
the corresponding opening in the bottom portion of the rigid
support base 808.
[0085] In some embodiments, because the piezoelectric stack 1022 is
not a screw, it should be secured to the tape deck base 918 via the
lower end support bracket 1126. The piezoelectric stack lip 1132
cups around a bottom portion of the piezoelectric stack 1022 and
helps secure and stabilize the piezoelectric stack 1022. The lower
end support bracket 1126 is then secured to the tape deck base 918
via two screws (not shown) inserted through the two connecting
screw openings 1128 and 1130. In some embodiments, two
corresponding openings are made (e.g., drilled) for the two
connecting screws to be inserted.
[0086] In some embodiments, once the piezoelectric stack 1022 is
secured in place, the piezoelectric stack 1022 can tilt the tape
guide roller bearing 802, in a skew direction to improve the motion
of the tape 804 in a tape path. The piezoelectric stack 1022 tilts
the tape guide roller bearing 802 by either expanding or
contacting, which pushes or pulls the support rod 1020 into or away
from the rigid support base 808, which in turn would tilt the tape
guide roller bearing 802 as it is affixed to the rigid support
shaft 806.
[0087] In some embodiments, the tilt of the tape guide roller
bearing 802 is askew from the center of the rigid support base 808.
That is, because the piezoelectric stack 1022 is positioned through
the third opening 916, which is depicted to the right of the center
of the assembly of the dynamic tape guide bearing tilt mechanism
1200, the tape guide roller bearing 802 tilts to the left when the
piezoelectric stack 1022 expands and will not tilt to the right
(e.g., the physical presence of the rigid support base 808 prevents
the tape guide roller bearing 802 from tilting past it).
[0088] It is noted that the tape deck post 910 and the jack set
screw 1206, along with the support rod 1020 of the piezoelectric
stack 1022 create a 3-point contact system for the dynamic tape
guide bearing tilt mechanism 1200, such that when the piezoelectric
stack 1022 is raised or lowered, the rigid support base 808 will
tilt in the skew direction while remaining in contact with the
other two contact points (e.g., the tape deck post 910 and the jack
set screw 1206). This can be done because the center screw 1204 and
the Belleville spring washer 1202 act as a constant downward force
to ensure the rigid support base 808 remains in contact with the
three "posts" at all times, e.g., the tape deck post 910, the jack
set screw 1206, and the support rod 1020. Further, the Belleville
spring washer 1202 allows for small amounts of tilt to occur when
the piezoelectric stack 1022 is expanded or contracted.
[0089] It is further noted that the embodiments discussed in this
disclosure and in regard to the FIGS. 1-12 can be contemplated to
be used either individually or in any combination that could
therein with be envisioned.
[0090] The descriptions of the various embodiments of the present
disclosure have been presented for purposes of illustration, but
are not intended to be exhaustive or limited to the embodiments
disclosed. Many modifications and variations will be apparent to
those of ordinary skill in the art without departing from the scope
and spirit of the described embodiments. The terminology used
herein was chosen to best explain the principles of the
embodiments, the practical application or technical improvement
over technologies found in the marketplace, or to enable others of
ordinary skill in the art to understand the embodiments disclosed
herein.
[0091] Although the present disclosure has been described in terms
of specific embodiments, it is anticipated that alterations and
modification thereof will become apparent to the skilled in the
art. Therefore, it is intended that the following claims be
interpreted as covering all such alterations and modifications as
fall within the true spirit and scope of the disclosure.
* * * * *