U.S. patent application number 15/046395 was filed with the patent office on 2017-08-17 for high performance robotic optical storage system.
The applicant listed for this patent is International Business Machines Corporation. Invention is credited to David J. Altknecht, John S. Best, Donald S. Bethune, William M. Dyer, A. David Erpelding, Steven R. Hetzler, Drew B. Lawson, Daniel F. Smith.
Application Number | 20170236545 15/046395 |
Document ID | / |
Family ID | 59561689 |
Filed Date | 2017-08-17 |
United States Patent
Application |
20170236545 |
Kind Code |
A1 |
Altknecht; David J. ; et
al. |
August 17, 2017 |
HIGH PERFORMANCE ROBOTIC OPTICAL STORAGE SYSTEM
Abstract
An apparatus includes one or more disc media cassettes
configured to store multiple disc-based media. Multiple disc drives
are configured to read and write data to the multiple disc-based
media. A robotic delivery device is configured to transport a
selected disc-based media to and from at least one disc drive of
the multiple disc drives, and to transport the selected disc-based
media directly to a spindle on the at least one disc drive.
Inventors: |
Altknecht; David J.; (San
Jose, CA) ; Best; John S.; (San Jose, CA) ;
Bethune; Donald S.; (San Jose, CA) ; Dyer; William
M.; (San Jose, CA) ; Erpelding; A. David; (San
Jose, CA) ; Hetzler; Steven R.; (Los Altos, CA)
; Lawson; Drew B.; (Aptos, CA) ; Smith; Daniel
F.; (Felton, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
International Business Machines Corporation |
Armonk |
NY |
US |
|
|
Family ID: |
59561689 |
Appl. No.: |
15/046395 |
Filed: |
February 17, 2016 |
Current U.S.
Class: |
720/714 |
Current CPC
Class: |
G11B 17/228 20130101;
G11B 17/04 20130101; G11B 17/038 20130101; G11B 17/225 20130101;
G11B 17/22 20130101 |
International
Class: |
G11B 17/22 20060101
G11B017/22 |
Claims
1. An apparatus comprising: one or more disc media cassettes
configured to store a plurality of disc-based media; a plurality of
disc drives configured to read and write data to disc-based media;
a robotic delivery device comprising a gripping device, the robotic
delivery device configured to transport a selected disc-based media
to and from at least one disc drive of the plurality of disc
drives, and to transport the selected disc-based media directly to
a spindle on the at least one disc drive, and the gripping device
is configured to grip a disc-based media by an arc segment along an
outer edge.
2. The apparatus of claim 1, wherein: the disc-based media are
optical media and the plurality of disc drives are optical drives;
the one or more disc media cassettes are disposed along a left side
and a right side of an enclosure; and the one or more disc media
cassettes each comprise a pair of extensions configured to retain
the one or more disc cassettes in a pair of tracks within the
enclosure.
3. The apparatus of claim 1, wherein the robotic delivery device
comprises a lifting device configured to lift a disc-based media
out of a disc media cassette towards the gripping device.
4. The apparatus of claim 3, wherein the lifting device is
configured to lift the disc-based media by contacting an outer edge
of the disc-based media at a point below a horizontal centerline of
the disc-based media and to an interior portion of the enclosure
from a vertical centerline of the disc-based media.
5. The apparatus of claim 4, wherein: the lifting device is a
disc-kicker including a blade configured to rotate about a fixed
axis to move the blade into contact with the disc-based media and
to lift the disc-based media from the disc media cassette; the
disc-kicker is integral to the robotic delivery device; the
disc-kicker is configured to push a disc-based media from the outer
edge of the disc-based media facing the robotic delivery device;
and the disc-kicker is configured to force the disc-based media
into the gripping device that is positioned above the disc-based
media.
6. The apparatus of claim 5, wherein: the robotic delivery device
includes a lower portion having a groove; the groove constrains a
bottom portion of the outer edge of the disc-based media in a
transport position or laterally positioned within a disc radius of
a center of a disc carrier of the robotic delivery device; and the
blade is configured to have controlled movement in a selected plane
based on the groove.
7. The apparatus of claim 6, wherein: the gripping device
translates laterally above the one or more disc media cassettes and
the plurality of disc drives; and a disc-based media delivered to a
position in a particular drive such that the disc-based media
mounts to the spindle when a spindle clamp is engaged.
8. The apparatus of claim 7, further comprising an enclosure
controller configured to respond to received read, write, mount and
dismount commands received by an interface, wherein: a tip of the
blade is configured to contact the outer edge of the disc-based
media; and the tip is shaped with a slot configured to prevent the
disc-based media from slipping sideways and losing contact with the
tip.
9. An apparatus comprising: one or more disc cassettes configured
to store a plurality of optical discs within an enclosure; and a
robotic delivery device comprising a gripping device, the robotic
delivery device configured to receive one or more control commands
and to transport a selected optical disc from a particular disc
cassette within the enclosure directly to a spindle of a particular
disc drive of a plurality of disc drives within the enclosure, and
the gripping device is configured to grip an optical disc by an arc
segment along an outer edge
10. The apparatus of claim 9, wherein: the one or more disc media
cassettes are disposed along a left side and a right side of the
enclosure; and the one or more disc cassettes each comprise a pair
of extensions configured to retain the one or more disc cassettes
in a pair of tracks within the enclosure.
11. The apparatus of claim 9, wherein the robotic delivery device
comprises a lifting device configured to lift an optical disc out
of a disc cassette upwards towards the gripping device.
12. The apparatus of claim 11, wherein the lifting device is
configured to lift the optical disc by contacting both surfaces in
an outer edge region of the optical disc.
13. The apparatus of claim 12, wherein: the lifting device is a
disc-kicker including a blade configured to rotate about a fixed
axis to move the blade into contact with the optical disc and to
lift the optical disc from a disc cassette; the disc-kicker is
integral to the robotic delivery device; the disc-kicker is
configured to push an optical disc from an edge of the optical disc
facing the robotic delivery device; and the disc-kicker is
configured to force the optical disc into the gripping device that
is positioned above the optical disc.
14. The apparatus of claim 13, wherein: the robotic delivery device
includes a groove disposed in a lower portion; the groove controls
a bottom portion of the outer edge of the optical disc in a
transport position or laterally positioned within a disc radius of
a center of a disc carrier of the robotic delivery device; the
blade is configured to have controlled movement in a selected plane
based on the groove; a tip of the blade is configured to contact
the outer edge of the optical disc; and the tip is shaped with a
slot configured to prevent the optical disc from slipping sideways
and losing contact with the tip.
15. The apparatus of claim 14, wherein: the gripping device
translates laterally above the one or more disc cassettes and the
plurality of disc drives; and an optical disc is delivered to a
position in the particular disc drive of the plurality of disc
drives to mount to the spindle when a spindle clamp is engaged.
16. The apparatus of claim 15, further comprising an enclosure
controller configured to be responsive to received read, write,
mount and dismount commands received by an interface.
17. A rack mounted apparatus comprising: an enclosure including
external rack mounting portions; one or more disc cassettes
configured to store a plurality of optical discs within the
enclosure; and a moveable robotic delivery device comprising a
movable disc retrieval portion including a gripping device, and an
enclosure transporter, the robotic delivery device configured to
receive one or more commands and to transport a selected optical
disc from a particular disc cassette within the enclosure directly
to a spindle of a particular disc drive of a plurality of disc
drives within the enclosure, and the gripping device is configured
to grip an optical disc by an arc segment along an outer edge.
18. The rack mounted apparatus of claim 17, wherein: the robotic
delivery device includes a groove disposed in a lower portion; and
the groove controls a bottom portion of an outer edge of the
optical disc in a transport position or laterally positioned within
a disc radius of a center of a disc carrier of the robotic delivery
device.
19. The rack mounted apparatus of claim 17, wherein: the gripping
device translates laterally above the one or more disc cassettes
and the plurality of disc drives; and an optical disc is delivered
to a position in the particular disc drive of the plurality of disc
drives to mount to the spindle when a spindle clamp is engaged.
20. The rack mounted apparatus of claim 17, further comprising an
enclosure controller configured to be responsive to received read,
write, mount and dismount commands received by an interface.
Description
BACKGROUND
[0001] Today's optical libraries have low performance, with access
times of 10s of seconds to a minute or more. While optical drives
allow fast random access to data on a disc, the overall random
access performance is limited by the media move time and drive
initialization times. The latter limitations means that today's
optical systems are largely designed for slow tier operations.
SUMMARY
[0002] Embodiments of the invention relate to robotic devices for
data reading from and writing to media storage devices. In one
embodiment, an apparatus includes one or more disc media cassettes
configured to store multiple disc-based media. Multiple disc drives
are configured to read and write data to the multiple disc-based
media. A robotic delivery device is configured to transport a
selected disc-based media to and from at least one disc drive of
the multiple disc drives, and to transport the selected disc-based
media directly to a spindle on the at least one disc drive
[0003] These and other features, aspects and advantages of the
present invention will become understood with reference to the
following description, appended claims and accompanying
figures.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] FIG. 1 is a high performance optical storage system,
according to an embodiment;
[0005] FIG. 2 shows entry/removal of disc cassettes with optical
discs and optical disc drives into/out from an example rack
enclosure, according to an embodiment;
[0006] FIG. 3 is an example disc cassette for holding and retrieval
of optical discs, according to an embodiment;
[0007] FIGS. 4A-F show retrieval of an optical disc from the
cassette shown in FIG. 3 by the disc retrieval unit (DRU) including
a kicker device and disc gripper device, according to an
embodiment;
[0008] FIG. 5 is an isolated view of the DRU and an optical disc
being held by the disc gripper device, according to an
embodiment;
[0009] FIG. 6 is a close-up view of a disc carrier portion of the
DRU and an optical disc being gripped by the disc gripper device,
according to an embodiment;
[0010] FIG. 7 is a close-up view of a kicker tip of the DRU,
according to an embodiment;
[0011] FIGS. 8A-E show progression for loading of an optical disc
into a disc drive from the DRU, according to an embodiment;
[0012] FIG. 9 shows control circuitry and electronics for the high
performance optical storage system, according to an embodiment;
[0013] FIG. 10 illustrates a block diagram for a process for disc
drop off by the high performance optical storage system, according
to one embodiment; and
[0014] FIG. 11 illustrates a block diagram for a process for disc
pickup by the high performance optical storage system, according to
one embodiment.
DETAILED DESCRIPTION
[0015] The descriptions of the various embodiments of the present
invention 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.
[0016] One or more embodiments integrates specialized high speed
robotics, robust mechanical design, performance enhanced drives and
a high failure tolerance erasure code to achieve low access times.
The system includes components that provide high storage density
and performance. Achieving high speed operation requires rapid
acceleration, high move velocity and rapid pick-up, drop-off, drive
spin-up, and initialization operations. High storage density
requires tight disc spacing, and thus highly accurate and
repeatable positioning within the system.
[0017] FIG. 1 is a high performance optical storage system 100,
according to an embodiment. In one embodiment, the high performance
optical storage system 100 includes an enclosure 110, a moveable
arm 120 connected to a disc retrieval unit (DRU) 125, multiple
optical disc drives 130, multiple optical disc-based media (discs)
140, disc cassettes 150, and tracks 160 and 165 that hold the disc
cassettes 150 in place. In one embodiment, the enclosure 110
provides a stable platform and protection from the environment. In
one example, the enclosure includes filter material connected to
cooling fans (not shown) and a top enclosure (not shown for
internal viewing). In one embodiment, the enclosure may be sized as
a typical 19 inch rack mounted device with rack mounting
connectors. Depending on the space and enclosure size chosen, the
enclosure 110 may have a greater capacity of optical disc drives
130, disc cassettes 150, and thus, discs 140. In one example, the
disc cassettes 150 are placed within the enclosure 110 on either
side (e.g., left and right sides) of the enclosure 110. In one
example, additional disc cassettes 150 and discs 140 space is
available adjacent the disc drives 130 (e.g., towards the front of
the enclosure 110). In wider enclosures 110, more disc drives 130
may be positioned adjacent each other on the left and right side of
the enclosure 110 when more available space for disc drives 130 is
available. In one embodiment, the moveable arm 120 moves through
motors and gears on tracks within the enclosure 110 to move the DRU
125 from the back of the enclosure 110 to the front of the
enclosure 110. The DRU 125 is moveable to either side of the
enclosure 110 to retrieve a disc 140 for placement in a disc drive
130 or for replacement back to a disc cassette 150. The components
of the high performance optical storage system are described in
further detail below.
[0018] FIG. 2 shows entry/removal of disc cassettes 150 with discs
140 and disc drives 130 into/out from an example rack enclosure
110, according to an embodiment. In one embodiment, the disc drives
130 are commonly mounted to a carrier assembly such that they can
be easily removed from one end of the enclosure 110 for
maintenance. This way, the set of disc drives 130 may plug into a
backplane in the carrier. The disc cassettes 150 are modular units
that hold many optical discs 140 (e.g., 50 discs, etc.) and may be
removed through an end of the enclosure 110. In one example, the
disc drives 130 are all positioned on one side of the enclosure
110. This allows all the disc drives 130 to be mounted in a single
carrier and still allow a central support at the end of the
enclosure 110. In one example, the enclosure 110 may have different
disc cassette 150 capacities on either side of the enclosure 110.
Using cassette 150 assemblies as shown allows for a single part to
be utilized on both sides of the enclosure 110 to create different
storage capacities as desired.
[0019] FIG. 3 is an example disc cassette 150 for holding/storing
and retrieval of optical discs 140, according to an embodiment. In
one embodiment, the discs 140 are contained in the disc cassettes
140 within a slot (or channel, groove, etc.) 355. The disc
cassettes 150 hold the discs coaxially in a vertical orientation.
The discs 140 are spaced very tightly, for example 1.82 mm apart.
Thin ribs (e.g., 0.4 mm) form the slot 355, separate the discs 140
and provide guidance when removing a disc 140 from a particular
location or returning it to the disc cassette 150. In one
embodiment, the ribs are designed to limit lateral contact with a
disc 140 surface to that portion of the outer edge, which is free
of data (i.e., does not contain data). The cassette has features
that allow the DRU 125 (FIG. 1) to be positioned to within +/-0.1
mm so a disc selector or kicker device 420 (FIGS. 4A-F) can lift
one disc 140 into a disc gripper device 410 without disturbing
adjacent discs 140. The disc cassette has additional features or
track connectors 360, 365 and 370, 375 that position it with
respect to a mounting track 160/165 (FIG. 1) on the enclosure 110
bottom portion. In one embodiment, the track connectors 365 and 370
have a "dove tail" feature that fits within the track portions 165
and 160, respectively. In one example, the track connectors are
spring-like or flexible for gripping the mounting tracks
160/165.
[0020] In one embodiment, the disc cassette 150 contacts the outer
rim of the disc 140 over an angle spanning substantially less than
180 degrees (see lines 390) when the disc is at home in a disc
cassette 150. The cassette has a shorter lip 385 to the center of
the enclosure 110 (FIG. 1), and a taller lip 380 at the outside of
the enclosure 110. As described, a combination of gravity and
friction hold the discs 140 in place. To provide further protection
against shock, an optional disc retainer bale 395 may be employed
limiting the motion of the discs 140 when not being accessed. In
one example, the disc retainer bale 395 is be moved out of the way
(e.g., by the disc gripper device 410 (FIGS. 4A-F) when accessing a
disc 140. In one embodiment, the disc cassette 150 includes an
optional disc retainer bale 395. In one example, the disc retainer
bale 395 is spring-loaded.
[0021] FIGS. 4A-F show retrieval of an optical disc 140 from the
disc cassette 150 shown in FIG. 3 by the DRU 125 including a kicker
device 420 and disc gripper device 410, according to an embodiment.
In one embodiment, the disc cassette 150 is designed to provide
disc 140 access motions in both the vertical and horizontal
directions as show in FIGS. 4A-F. That is, the disc 140 is lifted
above the inner lip 385 (FIG. 3) and then translated to the center
of the enclosure 110 within the DRU 125. In FIG. 4A, the DRU 125 is
positioned by the robotics for alignment across from the selected
disc 140. In FIG. 4B, the disc gripper device 410 is moved
laterally from the center of the DRU 125 to a position vertically
above the selected disc 140. If there is a restraint mechanism on
the cassette (e.g., disc retainer bale 395 (FIG. 3), it is moved
out of the way by the disc gripper device 410.
[0022] In FIG. 4C the disc kicker device 420 is rotated by the
robotic controller of the DRU 125 until it contacts the edge of the
disc 140. In FIG. 4D the disc kicker device 420 is further rotated
by the robotic controller remaining in contact with edge of the
disc 140. The shape of the disc cassette 150 constrains the disc
140 to move it vertically by lifting the disc 140 into the disc
gripper device 410. During this operation, the edge of the disc 140
near the outside of the enclosure 110 is constrained against
out-of-plane motion by the slot 355 (FIG. 3) in the disc cassette
150. Once the disc 140 has reached its vertical limit, the disc
gripper device 420 closes jaws 415 (FIG. 5) on both surfaces of the
disc 140 in the edge region, securely holding the disc 140. In FIG.
4E the disc kicker device 420 is retracted by the robotic
controller of the DRU 125 to the central position. In FIG. 4F the
disc gripper device 410 is returned to the central position within
the DRU 125, moving the disc 140 into the travel position. In one
example, the angle of contact subtended by the disc cassette 150
must be limited to allow for this motion of the disc 140. Further,
the extension of the disc cassette 150 slot 355 above the storage
contact point of the disc 140 provides a vital out of plane motion
restraint for the disc 140. The slot 355 further operates as a
guide when a disc 140 is returned to the disc cassette 150.
[0023] In one embodiment, the slot 355 pitch is slightly larger
than the thickness of a disc 140. Tighter spacing allow for more
discs 140 to fit in the enclosure 110. This spacing is limited by
the disc cassette 150 materials to maintain the disc 140
orientation. The disc cassette is preferably made by injection
molding. However, other molding techniques may also be employed. In
one example, the disc cassette 150 includes "dove tails" on the
track connectors 365 and 370 disposed along the bottom to
facilitate position registration and to securely hold the disc
cassettes 150 in place, while allowing for the cassettes to be
inserted and extracted from the enclosure 110 by sliding out an end
of the enclosure 110.
[0024] FIG. 5 is an isolated view of the DRU 125 and an optical
disc 140 being held by the jaws 415 of the disc gripper device 410,
according to an embodiment. In one embodiment, the DRU 125 is
configured in a "T" configuration, with a crossbar or arm 120 that
travels above the discs 140 and has a central portion attached
beneath the arm 120. The arm 120 moves longitudinally along the
center of the enclosure 110, driven by a motor 510 that travels
with the arm 120. In one example, the motor 510 drives the arm 120
via pinion attachments 520 on both ends of the arm 120 that engage
racks on both sides of the enclosure 110. In one example, the DRU
125 is supported on bearings at either end of the arm 120. The
mechanical arrangement thus drives both ends in concert along the
racks of the enclosure 110. This arrangement prevents the DRU 125
from binding due to bearing friction. It also aids in keeping the
DRU 125 rigid and limits twisting motion, which allows for tight
tolerances on the disc 140 spacing. In one example, the DRU 125
includes a wiring control connector 530 that communicate control
commands to the controlling circuitry of the DRU 125.
[0025] FIG. 6 is a close-up view of a disc carrier portion of the
DRU 125 and a disc 140 being gripped by the disc gripper device
410, according to an embodiment. In one embodiment, the DRU 125
includes the disc gripper device 410, which holds the disc 140 by
both surfaces in the edge region. The disc gripper device 410
travels laterally on the arm 120, such that it can be positioned
over discs 140 on either side of the enclosure 110 (FIG. 1), in the
center for travel, and at the dropoff/pickup positions at the disc
drives 130. The central portion of the DRU 125, which is a disc
carrier including the disc kicker device 420 that lifts the discs
140 out of the disc cassette 150 using a motor 610, control
electronics, sensors 630, and a disc guide (groove or slot) 620.
The disc guide 620 constrains the bottom edge of the disc 140 when
the disc gripper device 410 is positioned in the carrier. This
keeps the disc 140 stable during high speed accelerations and from
windage during high speed motion of the arm 120, allowing the DRU
125 to move a disc 140 from one end of the enclosure 110 to the
other in under 1 second.
[0026] In one embodiment, the disc guide 620 has a capture region
at either side to provide tolerance for deviations of the disc 140
orientation from perfectly vertical when moving the disc 140 into
the carrier. In one example, a further aspect of the disc guide 620
is that it also acts as a guide for the disc kicker device 420,
keeping the disc 140 and disc kicker device 420 properly registered
to each other.
[0027] In one embodiment, the DRU 125 does not require a traveling
lateral power connection (Flex cable, wire harness, etc.) to
function. In one example, the DRU 125 is designed such that power
is only required at discrete lateral positions of the disc gripper
device 410. These discrete lateral positions are located at the
left and right dropoff/pickup positions. Power is provided here by
contacts, such as pushpins, that the laterally moving portion comes
into contact with at the stated positions. This operation is
facilitated by the disc gripper device 410 being powered only to
perform grip or un-grip operations. No power is required when
holding a disc 140.
[0028] In one embodiment, the disc 140 media may be single sided or
dual sided. The disc drives 130 (FIG. 1) may have single sided or
dual sided capable. It may be that single side disc drives 130 are
used in combination with dual side media. In such a case, in one
embodiment the DRU 125 may include a mechanism to flip the disc 140
about a vertical axis to orient the desired side of the media for
drive operations. In one example, the flip operation may occur
while transporting the media, thus has limited or no impact on
performance. In another example, a separate mechanism flips the
discs 140. In this example, the DRU 125 delivers a disc 140 to the
flipper and retrieves it after it has been flipped. Another example
includes orienting a subset of the disc drives 130 for operating on
one side of the discs 140, and the remaining drives for operating
on the other side of the discs 140. This avoids the need to perform
a flip operation.
[0029] FIG. 7 is a close-up view of a kicker tip 710 for the disc
kicker device 420 of the DRU 125, according to an embodiment. In
one embodiment, 1.2 mm thick discs 140 are packed on 1.82 mm
centers in the disc cassette 150, leaving 0.62 mm between discs
140. A disc 140 must be rapidly selected from the disc cassette
140, secured by the disc gripper device 410 (FIGS. 4A-F), and moved
onto the DRU 125 (FIG. 1) for transport to a disc drive 130 without
disturbing or damaging adjacent discs 140. In one example, discs
140 must also be returned to their slots 355 after the requested
data has been read.
[0030] In one embodiment, a motor 610 (FIG. 6) actuated disc kicker
device 420 on the disc carrier of the DRU 125 is swung back and
forth to contact discs 140 on either side of the enclosure 110
(FIG. 1). A tip 710 of the disc kicker device 420 aligned with one
of the discs 140 contacts the disc edge and, with the disc 140 back
edge guided by fins in the back wall of the disc cassette 150,
lifts the disc 140 vertically into the disc gripper device 410 jaws
415 (FIG. 5) or lowers it out of the disc gripper device 410 back
into the disc cassette 150. In one embodiment, the tip 710 of the
disc kicker device 420 blade are somewhat wider than the disc 140
and are shaped to capture the disc 140 edge, thus preventing the
disc 140 from slipping off the tip 710. In other example, blade
tips 710 with a concave contour or a shallow trapezoidal groove may
be employed to fulfill this objective.
[0031] FIGS. 8A-E show progression for loading of an optical disc
140 into a disc drive 130 from the DRU 125 (FIG. 1), according to
an embodiment. The disc gripper device 410 is designed to securely
hold a disc 140 using the jaws 415 with sufficient force to allow
rapid acceleration without the disc 140 slipping, and to enable
rapid gripping and releasing of the disc 140. The disc 140 surface
must not be damaged during these operations. A further aspect of
the disc gripper device 410 is that it must not drop a disc 140 on
power loss, thus power is required only to transition between
gripped and un-gripped states. In one embodiment, the disc gripper
device 410 jaws 415 are shaped so as to contact only the non-data
portion of the outer diameter of a disc 140. This may be
facilitated by gripping the disc 140 edge over an angle of about 35
degrees.
[0032] In one embodiment, the disc gripper device 410 is mounted on
a high speed translation mechanism on the arm 120, such as a lead
screw. The disc gripper device 410 can translate laterally such
that it can access discs 140 on both sides of the enclosure 110
(FIG. 1), and to the disc mount position in the disc drives 130. In
one example, the disc gripper device 410 mechanism may be provided
with a stage for rotating the disc 140 about a vertical axis to
allow the use of double-sided media with single-sided disc drives
130. In another example, a second disc gripper device (not shown)
is positioned with rotation capability at fixed location in the
enclosure 110. The disc 140 is delivered to the second disc gripper
device, and the first disc gripper releases the disc 140 and moves
away. The second disc gripper device rotates the disc through 180
degrees, and then the first disc gripper device (e.g., disc gripper
device 410) returns and retrieves the disc 140 from the second disc
gripper device. The second disc gripper device may be positioned on
the bottom of the enclosure 110 and rotate the disc 140 about a
vertical axis, or it may be mounted to a side of the enclosure 110
and rotate the disc 140 about a horizontal axis. To facilitate
throughput, the DRU 125 may move a second disc 140 between the
storage area and the disc drives 140 while the first disc 140 is
being flipped.
[0033] In one embodiment, direct robotic delivery and pickup of
media to and from a mount position at the optical drive spindle 810
is implemented. The mount position is defined as where the center
of the optical disc is displaced in the plane of the disc from the
center of the spindle by less than an inner diameter of the optical
disc. This differs from conventional designs, where the disc is
delivered to a tray or slot load optical drive. Direct load
improves the round trip time for a disc 140 by about 4 seconds, as
it avoids the roughly a 2 second tray/slot load and unload times. A
further advantage is that both tray and slot load mechanisms are
subject to mechanical breakdown, limiting the drive lifetime in
terms of load/unload cycles. One or more embodiments avoid such
wear-out mechanisms. A further advantage is that high density disc
packing requires tight tolerance in the disc retrieval from the
disc drive 130. Tray and slot loaders have significant slop in the
position of the disc when presented for pickup. In one example, a
disc drive 130 includes a modified conventional disc drive that is
customized to provide direct access operations. An opening is
provided in the drive case to allow the disc gripper device 410 to
move to the spindle 810 mount position. The disc gripper device 410
jaws 415 clamping mechanism is used to secure the disc 140 after
the disc 140 is unclamped from the spindle 810.
[0034] In one embodiment, the hub mechanism of the disc drive 130
is shock mounted, and this provides sufficient tolerance to allow
the disc gripper device 410 to securely grip a disc 140 over a
range of mounted disc positions, and to allow the spindle clamp to
grip a disc 140 being delivered over a range of positions. The
compliance provided by the hub mechanism shock mounting allows the
disc gripper device 410 to be positioned such that there is a
slight vertical interference between the top of the disc 140 and a
disc sense mechanism of the disc gripper 410 when it is in its
limiting "disc present" position. This insures that the disc 140
will have a vertical net force against a disc sense mechanism in
its limit position when the disc gripper device 410 is actuated at
the disc drive 130. In one example, the implementation of the
direct access customized disc drive 130 provides for
mounting/unmounting of a disc 140 to be accomplished in about 1
second.
[0035] In one embodiment, to mount a disc 140 in the disc drive
130, the DRU 125 moves to the longitudinal position for dropoff at
the chosen disc drive 130 within the enclosure 110. The disc
gripper device 410 then translates laterally to the mount position,
and holds the disc 140 until the clamp mechanism has secured the
disc 140 on the spindle 810. In one example, the disc gripper 410
releases the disc 140 and retreats back to a centered position of
the DRU 125. Similarly, the disc 140 may be retrieved from the disc
drive 130 by securely gripping the disc 140 by the jaws 415 of the
disc gripper device 410 while it is held on the optical drive
spindle 810 (after it has stopped rotating and before the disc
drive 130 clamp has released it) so that the disc 140 is always
under positive control. In another embodiment, it is beneficial for
the disc drive 130 to include constraints, which allow the spindle
810 clamp to fail safe. This means that if the spindle 810 clamp
releases the disc 140 inadvertently, the disc 140 can either be
re-clamped by the spindle 810, or delivered to the disc gripper
410. During load, the disc gripper 410 could release prior to the
spindle 810 clamp being engaged, and during pickup the spindle 810
clamp can release before the gripper 410 engages.
[0036] In one embodiment, the disc drives 130 are positioned such
that the lateral disc dropoff/pickup position of the disc gripper
device 410 at the disc drives 130 differs only slightly (<1 cm)
from the lateral position for disc dropoff/pickup in the disc
cassette 150 (FIGS. 4A-F) on the same side of the enclosure 110
(FIG. 1) as the disc drives 130. The disc drive 130 is vertically
positioned such that the disc drive 130 mount position aligns with
a disc 140 in the disc gripper device 410. In one example, a shadow
mask is incorporated at the bottom edge of the disk drive 130 that
allows the DRU 125 to be longitudinally positioned to within +-0.1
mm.
[0037] In one embodiment, a further aspect includes the use of
optical disc drives 130 with high speed initialization features.
Such a disc drive 130 significantly reduces the time from disc 140
load to first byte of data. In standard disc drives, this operation
can take 10s of seconds as the drive performs operations such as
identifying the media type, reading bad block tables or other
initialization data off the media, etc. In one embodiment, an
inventory manager (described below) is implemented that stores and
transmits initialization information to the disc drive 130 on media
load, eliminating the time required by the disc drive 130 to read
this information from the disc 140. This reduces the initialization
time to around 1 second.
[0038] FIG. 9 shows control circuitry and electronics 900 for the
high performance optical storage system 100 (FIG. 1), according to
an embodiment. In one embodiment, optical sensors of the sensor set
920 are used in the system to provide contactless position
information for various moving components. In one example, optical
sensors of the sensor set 920 on the disc carrier of the DRU 125
combined with the features of the disc cassettes 150 and the disc
drives 130 allow the disc gripper device 410 to be positioned to
within +-0.1 mm. Other sensors of the sensor set 920 are used to
sense location of the disc kicker device 420, whether a disc 140 is
in the disc gripper device 410, the lateral position of the disc
gripper device 410, etc. Sensors of the sensor set 920 may be used
in concert with features on the disc cassettes 150 to facilitate
positioning of the DRU 125 at disc 140 locations. Other examples
include referring to the discs 140 themselves. Similarly, features
may be disposed on the enclosure 110 or the disc drives 130 to
facilitate accurate positioning of the DRU 125 when loading and
unloading discs 140 from the disc drives 130. In another example,
transmissive photo interrupter sensors may be utilized for position
state sensing of the various components. The motors used in the
system may be of the brushless DC type, optionally with shaft
encoders to aid in position determination. In one example, the
motors may include the DRU 125 longitudinal motor(s) 941, the
gripper device 410 lateral motor(s) 942, the gripper device 410
motor 943, the disc kicker device 420 motor(s) 944, etc.
[0039] In one embodiment, the control electronics shown in the
control circuitry and electronics 900 are partitioned into a
robotic controller (the disc carrier controller 930) on the disc
carrier and an enclosure controller 910 otherwise mounted in the
enclosure 110 (FIG. 1). The latter does not move, and includes a
CPU 912, memory 911 and associated components for running the
control software. In one example, the control circuitry and
electronics 900 includes local storage for holding the operating
system and the control software, although in another example may
instead boot over a network and load the necessary software, or
even boot off the optical media of a disc 140. In another example,
flash memory storage is implemented. The enclosure controller 910
includes both the external interface to a host system or network as
well as interfaces (SATA 913, storage interface 916) to the disc
drives 130, collectively shown as a set 917. In one example, the
external interface may include a network interface, such as
Ethernet. In one embodiment, for enhanced reliability, the network
interface would include two connections, such as Ethernet
connections 914 and 915 with each directed to a separate switch. In
another example, a third external interface might be used for
system control and monitoring.
[0040] In one embodiment, the enclosure controller 910 is
responsive to commands over the external interface to load a disc
140, read and write data, and perform other operations. In one
example, the enclosure controller 910 communicates with the robotic
controller (disc carrier controller 930) to send commands, such as
to load a selected disc 140 (FIG. 1) in a selected disc drive 130.
The enclosure controller 910 also includes a data buffer for
holding read and write data during data transfers.
[0041] In one embodiment, the robotic controller (disc carrier
controller 930) manages the robotic activities of the high
performance optical storage system 100, including controlling the
motors, reading optical and other sensor data and communicating
state information with the enclosure controller 910. In one
embodiment, the robotic controller (disc carrier controller 930)
communicates with the enclosure controller 910 over a serial
interface. The interface may be wired, such as universal serial bus
(USB) over a flex cable, or wireless, such as infrared data
association (IRDA), BLUETOOTH.RTM., etc. In one example, on
initialization, it is critical for the disc carrier controller 930
to determine the physical state of the high performance optical
storage system 100 to prevent damage. If the high performance
optical storage system 100 has undergone a controlled shutdown,
this state information may be recorded within the library. Even so,
this shutdown state needs to be confirmed. The high performance
optical storage system 100 may have been powered down in an unknown
state, such as by an unintended power loss. For example, before the
DRU 125 can move longitudinally, the high performance optical
storage system 100 must determine if a disc 140 is in the disc
gripper device 410 and if so, position the disc gripper device 410
within the drive carrier prior to a longitudinal move. In one
embodiment, the sensors set 920 includes sensors to detect if the
disc gripper device 410 is centered, or to the left or right of
center. Thus, the disc gripper device 410 can be moved directly to
the center position. Similarly, sensors of the sensor set 920 are
provided to determine if the disc kicker device 420 is centered, or
to the left or right of center. Once both disc gripper device 410
and disc kicker device 420 are centered, the DRU 125 may be moved
longitudinally. All these functions are accomplished through means
of the set of sensors 920. In one embodiment, optical sensors are
used to make the position determinations.
[0042] In one embodiment, the high performance optical storage
system 100 determines if discs 140 are located within any of the
disc drives 130. The disc drives 130 may be queried to see if a
disc 140 is loaded and the spindle 810 clamped. It is possible for
a disc 140 to remain in a disc drive 130 but not be clamped by the
spindle 810. This can be tested by attempting a clamp
operation.
[0043] In one embodiment, an inventory manger is implemented that
includes metadata for each disc 140 in the high performance optical
storage system 100. In one example, the metadata may include the
media type, bad block table or other initialization information,
location of the disc within the enclosure 110, etc. The high
performance optical storage system 100 can transmit this
initialization information to a disc drive 130 upon the load
operation, which substantially shortens the startup time. The
inventory manager also queries the disc drive 130 on unload to
obtain updates to the media.
[0044] In one example, metadata, such as changes in the bad block
information, is stored by the inventory manager in nonvolatile
storage which may be external to the high performance optical
storage system 100. Any system metadata can be periodically flushed
to specific locations on the media in the library to create
self-described system state, such as for relocating a system.
Alternatively, the metadata may be stored on other nonvolatile
media in the enclosure controller 910.
[0045] In one embodiment, the high performance optical storage
system 100 software includes a library executive, which is
responsive to read, write, mount and dismount commands from a host
system. The library executive forwards mount and dismount commands
and information to the disc carrier controller 930. The mount
command information includes the disc location in the disc cassette
150 to select and the disc drive 130 to load. The dismount command
information includes information on the disc drive 130 to unload
and the target location for storing the disc 140 in the disc
cassette 150.
[0046] FIG. 10 illustrates a block diagram for a process 1000 for
disc 140 drop off by the high performance optical storage system
100, according to one embodiment. In one embodiment, the dropoff
and pickup of discs 140 (FIG. 1) directly at the spindle 810 (FIGS.
8A-E) may be facilitated by adjusting the operational timing of the
disc drive 130. In conventional disc drives, the operation of
engaging the spindle clamp spins up the spindle motor as soon as
the clamp engages. Similarly, unloading the disc generally
disengages the spindle clamp once the spindle motor has stopped
spinning. In one embodiment, it is advantageous to separate the
motor spinning from the spindle clamp engagement, as shown in
process 1000 (error recovery paths where operations have failed are
not shown for clarity). The dropoff operation involves the
following. In block 1010 the disc gripper device 410 moves the disc
140 into the dropoff position. Once this is achieved, in block 1020
the spindle clamp may be engaged. At this point, the disc 140 is
still secured in the disc gripper device 410. The disc is released
from the disc gripper device 410 and the disc gripper device 430 is
retracted. In block 1030 it is determined whether the spindle clamp
is successfully engaged or not. If the spindle clamp is not
successfully engaged, the process 1000 returned to block 1020.
Otherwise, process 1000 proceeds to block 1040. In block 1040 where
the disc gripper device 410 is un-gripped and retracted. In block
1050 it is determined whether the disc 140 was successfully
un-gripped and retracted. If the disc 140 was not successfully
un-gripped and the disc gripper 410 retracted, process 1000 returns
to block 1040. At this point the DRU 125 is free to perform an
operation on a different disc 140. Once the disc 140 is released
the spindle motor may be spun up in block 1060. In one example, it
may be desirable to delay the spin up until the disc gripper device
410 has retracted if there are clearance issues.
[0047] FIG. 11 illustrates a block diagram for a process 1100 for
disc pickup by the high performance optical storage system 100,
according to one embodiment. In one embodiment, the pickup process
1100 is roughly the inverse sequence to the dropoff process 1000
(FIG. 10). In block 1110 the spindle motor is spun down. In block
1120 it is determined whether the spindle motor has successfully
spun down or not. If the spindle motor has not successfully spun
down, process 1100 returns to block 1110. Otherwise, process 1100
proceeds to block 1130 where the spindle has stopped and the disc
gripper device 410 is moved to the pickup location. In block 1140
it is determined whether the disc gripper device 410 has moved to
the pickup location or not. If the disc gripper device 410 did not
move to the pickup location, process 1100 returns to block 1130 and
continues to attempt to move to the pickup location. Otherwise
process 1100 proceeds to block 1150. In block 1150, the disc
gripper device 410 then uses the jaws 415 to clamp the disc 140. In
block 1160 it is determined whether the jaws 415 successfully
clamped the disc 140 or not. If the jaws did not successfully clamp
the disc 140, process 1100 returns to block 1140. Otherwise,
process 1100 proceeds to block 1170. In block 1170 once the grip is
complete, the spindle clamp is disengaged. In block 1180 it is
determined whether the spindle clamp has been successfully
disengaged or not. If the spindle clamp has not been successfully
disengaged, process 1100 returns to block 1170. Otherwise, process
1100 proceeds to block 1190 where the disc gripper device 410 can
retract with the disc 140. If there is no interference issue, then
the disc gripper device 410 may be moved to the pickup position
prior to the spindle having stopped.
[0048] As will be appreciated by one skilled in the art, aspects of
the present invention may be a system, a method, and/or a computer
program product at any possible technical detail level of
integration. The computer program product may include a computer
readable storage medium (or media) having computer readable program
instructions thereon for causing a processor to carry out aspects
of the present invention.
[0049] The computer readable storage medium can be a tangible
device that can retain and store instructions for use by an
instruction execution device. The computer readable storage medium
may be, for example, but is not limited to, an electronic storage
device, a magnetic storage device, an optical storage device, an
electromagnetic storage device, a semiconductor storage device, or
any suitable combination of the foregoing. A non-exhaustive list of
more specific examples of the computer readable storage medium
includes the following: a portable computer diskette, a hard disk,
a random access memory (RAM), a read-only memory (ROM), an erasable
programmable read-only memory (EPROM or Flash memory), a static
random access memory (SRAM), a portable compact disc read-only
memory (CD-ROM), a digital versatile disk (DVD), a memory stick, a
floppy disk, a mechanically encoded device such as punch-cards or
raised structures in a groove having instructions recorded thereon,
and any suitable combination of the foregoing. A computer readable
storage medium, as used herein, is not to be construed as being
transitory signals per se, such as radio waves or other freely
propagating electromagnetic waves, electromagnetic waves
propagating through a waveguide or other transmission media (e.g.,
light pulses passing through a fiber-optic cable), or electrical
signals transmitted through a wire.
[0050] Computer readable program instructions described herein can
be downloaded to respective computing/processing devices from a
computer readable storage medium or to an external computer or
external storage device via a network, for example, the Internet, a
local area network, a wide area network and/or a wireless network.
The network may comprise copper transmission cables, optical
transmission fibers, wireless transmission, routers, firewalls,
switches, gateway computers and/or edge servers. A network adapter
card or network interface in each computing/processing device
receives computer readable program instructions from the network
and forwards the computer readable program instructions for storage
in a computer readable storage medium within the respective
computing/processing device.
[0051] Computer readable program instructions for carrying out
operations of the present invention may be assembler instructions,
instruction-set-architecture (ISA) instructions, machine
instructions, machine dependent instructions, microcode, firmware
instructions, state-setting data, configuration data for integrated
circuitry, or either source code or object code written in any
combination of one or more programming languages, including an
object oriented programming language such as Smalltalk, C++, or the
like, and procedural programming languages, such as the "C"
programming language or similar programming languages. The computer
readable program instructions may execute entirely on the user's
computer, partly on the user's computer, as a stand-alone software
package, partly on the user's computer and partly on a remote
computer or entirely on the remote computer or server. In the
latter scenario, the remote computer may be connected to the user's
computer through any type of network, including a local area
network (LAN) or a wide area network (WAN), or the connection may
be made to an external computer (for example, through the Internet
using an Internet Service Provider). In some embodiments,
electronic circuitry including, for example, programmable logic
circuitry, field-programmable gate arrays (FPGA), or programmable
logic arrays (PLA) may execute the computer readable program
instructions by utilizing state information of the computer
readable program instructions to personalize the electronic
circuitry, in order to perform aspects of the present
invention.
[0052] Aspects of the present invention are described herein with
reference to flowchart illustrations and/or block diagrams of
methods, apparatus (systems), and computer program products
according to embodiments of the invention. It will be understood
that each block of the flowchart illustrations and/or block
diagrams, and combinations of blocks in the flowchart illustrations
and/or block diagrams, can be implemented by computer readable
program instructions.
[0053] These computer readable program instructions may be provided
to a processor of a general purpose computer, special purpose
computer, or other programmable data processing apparatus to
produce a machine, such that the instructions, which execute via
the processor of the computer or other programmable data processing
apparatus, create means for implementing the functions/acts
specified in the flowchart and/or block diagram block or blocks.
These computer readable program instructions may also be stored in
a computer readable storage medium that can direct a computer, a
programmable data processing apparatus, and/or other devices to
function in a particular manner, such that the computer readable
storage medium having instructions stored therein comprises an
article of manufacture including instructions which implement
aspects of the function/act specified in the flowchart and/or block
diagram block or blocks.
[0054] The computer readable program instructions may also be
loaded onto a computer, other programmable data processing
apparatus, or other device to cause a series of operational steps
to be performed on the computer, other programmable apparatus or
other device to produce a computer implemented process, such that
the instructions which execute on the computer, other programmable
apparatus, or other device implement the functions/acts specified
in the flowchart and/or block diagram block or blocks.
[0055] The flowchart and block diagrams in the Figures illustrate
the architecture, functionality, and operation of possible
implementations of systems, methods, and computer program products
according to various embodiments of the present invention. In this
regard, each block in the flowchart or block diagrams may represent
a module, segment, or portion of instructions, which comprises one
or more executable instructions for implementing the specified
logical function(s). In some alternative implementations, the
functions noted in the blocks may occur out of the order noted in
the Figures. For example, two blocks shown in succession may, in
fact, be executed substantially concurrently, or the blocks may
sometimes be executed in the reverse order, depending upon the
functionality involved. It will also be noted that each block of
the block diagrams and/or flowchart illustration, and combinations
of blocks in the block diagrams and/or flowchart illustration, can
be implemented by special purpose hardware-based systems that
perform the specified functions or acts or carry out combinations
of special purpose hardware and computer instructions.
[0056] References in the claims to an element in the singular is
not intended to mean "one and only" unless explicitly so stated,
but rather "one or more." All structural and functional equivalents
to the elements of the above-described exemplary embodiment that
are currently known or later come to be known to those of ordinary
skill in the art are intended to be encompassed by the present
claims. No claim element herein is to be construed under the
provisions of 35 U.S.C. section 112, sixth paragraph, unless the
element is expressly recited using the phrase "means for" or "step
for."
[0057] The terminology used herein is for the purpose of describing
particular embodiments only and is not intended to be limiting of
the invention. As used herein, the singular forms "a", "an" and
"the" are intended to include the plural forms as well, unless the
context clearly indicates otherwise. It will be further understood
that the terms "comprises" and/or "comprising," when used in this
specification, specify the presence of stated features, integers,
steps, operations, elements, and/or components, but do not preclude
the presence or addition of one or more other features, integers,
steps, operations, elements, components, and/or groups thereof.
[0058] The corresponding structures, materials, acts, and
equivalents of all means or step plus function elements in the
claims below are intended to include any structure, material, or
act for performing the function in combination with other claimed
elements as specifically claimed. The description of the present
invention has been presented for purposes of illustration and
description, but is not intended to be exhaustive or limited to the
invention in the form 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 invention. The
embodiment was chosen and described in order to best explain the
principles of the invention and the practical application, and to
enable others of ordinary skill in the art to understand the
invention for various embodiments with various modifications as are
suited to the particular use contemplated.
* * * * *