EASILY CONFIGURABLE AND SWAPPABLE MULTICOMPONENT LIBRARY SYSTEM
The present invention relates to a dynamic information storage and retrieval system, and particularly to an easily expandable library system. More particularly, the invention relates to a 5 library system which is easily expandable by adding additional library modules.
Advances in manufacturing technologies and system architecture have led to increasingly powerful electronic devices and computers. These electronic devices and computem support features and applications, in which vast amounts of information are processed and stored.
Generally, the amount of information is not only vast, but also everincreasing.
10 To provide the information needed by today's high powered applications, storage technologies have been developed to meet the high capacity data storage needs created.
Various storage options include hard disk drives, or drives using removable storage media such as magnetic, optical and magneto-optical media. Although these technologies provide relatively large storage capabilities, ongoing improvement is continually necessary so as to overcome 15 factors limiting storage capacity and performance.
Data storage libraries, or jukeboxes, are robotically controlled storage devices that have been developed to improve the efficacy of storage by automating nearly all data management functions. Every phase of library operations minimizes human intervention, which is the most common cause of data loss. A traditional tape jukebox consists of a series of bays or slots 20 storing a number of tapes. A robotic picker is computer controlled so that it can move any chosen tape from its storage bay and load the tape onto a tape drive unit. The entire jukebox is housed in a sealed environment to prevent contamination of the tapes. Similar jukebox libraries have also been built for virtually all types of storage media, including optical disks. Because jukeboxes store tens or hundreds of tapes, optical disks, or other media, and because the 25 jukeboxes can automatically swap disks and tapes in and out of the read devices, a single jukebox can effectively store much more information than a single tape drive or optical drive.
This makes jukeboxes very advantageous.
As can be easily appreciated, the capacity of a standard jukebox can be limited by its physical size. Simply stated, only so many tapes or optical media can fit within the prescribed 30 housing size, resulting in a limitation. Obviously, the jukeboxes are available in various sizes, however it is often not economical to buy vastly oversized devices simply for the sake of possible future expansion. Consequently, it would be desirable to create a jukebox system which could easily be expanded to include additional modules which would cooperate with one another.
In one example of past library systems, a rack mounted library module is used initially to meet the user's storage needs. When it is desired to expand, a number of library modules are connected to one another via an external conversion mechanism. Some example expansion products include the Stacklink, manufactured by Quantum Corporation of Milpitas, California, 5 and the XpressChannel, manufactured by Overland Data of San Diego, California. Using these expansion devices, each particular module is its own operating jukebox or library including a picker mechanism and appropriate storage slots. Expandability is achieved through the use of the aforementioned external integration system which is specifically designed and configured to allow tapes to be transferred from one library module to another library module. Essentially, 10 these expansion systems physically tie the various modules together.
Unfortunately, these expansion systems are specifically designed for the particular expansion being undertaken. For example, if two library modules are to be connected, a specific "two library rail" is required, which is attached to the back of the libraries. Similarly, a specifically configured expansion device is required for three library modules. Further, another 15 module is required for four modules, etc. While these expansion mechanisms do achieve the goal of integrating multiple library modules to one another, they are not easily expandable as a new expansion mechanism is required for each additional expansion. This becomes costly and cumbersome when trying to expand library modules. Furthermore, this does not accommodate the easily removal and replacement of library modules should that be necessary.
20 It would be particularly beneficial to devise a system which would allow for the easy integration of multiple library modules, without additional hardware. Further, such a system would be beneficial if it also accommodated the swapping (removal and replacement) of library modules. In order to address the above referenced issues related to expandability and module 25 swapping, preferred embodiments of the present invention provide an integral elevator support, or guide rail within each library module. This elevator support easily allows an elevator mechanism to move storage media between the various library modules without the use of additional components or pieces.
As mentioned above, the elevator system generally includes a guide rail or support which 30 is rigidly attached to each library module. This guide rail will include the necessary guide structures (slots) to direct elevator movement within an appropriately constrained area. These guide rails are also designed to provide necessary power to the elevator mechanism during its travel. Additionally, the guide rail may also includes gear teeth designed to interact with corresponding gears on the elevator mechanism itself.
The elevator mechanism or crawler itself is advantageously designed to interact with the guide rail to accommodate its movement. Further, a media holding mechanism is preferably attached to the elevator in order to carry the desired media. In the preferred embodiment, this includes media tape, however accommodations could easily made to handle optical storage 5 disks or other storage media.
The elevator itself preferably includes a drive motor and appropriate gearing, which will interact with gear teeth on the guide rail so as to carry the elevator along the path defined by the guide rail. Appropriate contacts are preferably provided to carry electrical power to the motor at all points along its travel.
10 Also included on the elevator is a control system coupled to the drive motor. As would be expected, this control system directs the actual movement of the elevator as it travels between the various library modules. The control system also advantageously includes a communication device which will communicate with a master library controller. In one embodiment, the communication is done through infrared or IR signals. This wireless communication between 15 these components allows for unrestrained movement of the elevator throughout its entire range of travel in a multi-module library system. Naturally, many alternative communication methods could be utilized, including RF, etc. Preferred embodiments of the present invention seek to provide a library module with the capability of being easily integrated into a library system including multiple modules. This 20 capability is achieved by providing an integral structure to accommodate a transport mechanism which is specifically configured and designed to transport storage media between the various modules. Furthermore the present invention also seeks to provide a library module which can be expanded without the use of additional hardware. in the design of the present invention, only 25 integral components of the library module are necessary to accommodate the expandability of the overall system.
Further, preferred embodiments of the present invention provide continual expansion capability at any time throughout the life of the storage library.
It is also preferable for embodiments of the present invention to provide a elevator 30 mechanism to a library module which is specifically configured and designed to carry storage media between various library modules within an overall storage system. The elevator mechanism cooperates with structures within the library module to easily accommodate and guide its movement.
Further preferred embodiments of the present invention seek to provide an elevator mechanism which includes communication capabilities so that the operation elevator can easily be controlled as it travels throughout the library system. The communication capabilities are preferably achieved in a wireless fashion, thus accommodating free movement of the library 5 through the entire library system.
For a better understanding of the present invention, and to show how the same may be carried into effect, reference will now be made, by way of example to the accompanying drawings, in which: Figure 1 is a perspective view of a rack mounted library system; 10 Figure 2 is a perspective view of a library module; Figure 3 is a top view of an opened library module; Figure 4 is a cross-sectional drawing showing a portion of the library module; Figure 5 is a first perspective view of the elevator assembly; Figure 6 is a second perspective view of the elevator assembly; 15 Figure 7 is a perspective view of the elevator mechanism alone; Figure 8 is a cross-sectional diagram illustrating elevator 110 "bridging the gap" between two library modules; and Figure 9 is a schematic diagram of the elevator system control devices.
As is known and understood by those skilled in the art, a data storage libraries can take 20 on many different configurations and layouts depending on the particular needs and design involved. One configuration is a rack-mounted data storage library which is capable of being mounted in a traditional equipment cabinet. Referring to Figure 1, there is shown one embodiment of a rack-mounted storage library 20 which includes a first library module 22, second library module 24 and a third library module 26. Each of these library modules is 25 mounted within a rack or cabinet 28. As can be seen, cabinet 28 includes two front face rails 30 which have a number of mounting holes 32 therein.
As can be seen, first library module 22, second library module 24 and third library module 26 are mounted within cabinet 28 at positions which are immediately adjacent one another.
This alignment allows for the exploitation of cartridge sharing functions, which are described 30 further below.
Referring now to Figure 2, there is shown a more detailed drawing of a first library module 22. It is understood that first library module 22, second library module 24 and third library module 26 are all similarly configured. Consequently, all comments and description regarding
the structure of these components are equally applicable to any library module. As can be
seen, first library module 22 includes an enclosed housing 40 which includes a front panel 42, a top panel 44, a bottom panel 46 (not shown) and a pair of side panels 48. Front panel 42 is designed to extend beyond side panels 48, which facilitates rack mounting as shown in Figure 1. 5 Front panel 42 includes a cartridge loading opening 50 which allows data storage cartridges to be inserted into the interior of housing 40 and accommodates the population of this library module 22. In order to accommodate the disk cartridge sharing capabilities of the present invention, housing 40 also includes an opening 52 positioned in the top panel 44 thereof. Opening 52 has a pair of cover mount rails 54 positioned on either side of the opening 10 to accommodate the attachment of a cover plate 56 (not shown). A pair of cover screw attachment holes 58 are also shown in cover mount rails 54. As can be appreciated, these holes accommodate the attachment of cover plate 56.
As mentioned above, the first library module 22 (and all library modules contained within a rack mounted library system) are configured to allow storage cartridges to be transferred 15 between the various modules. The first portion of the structure which accommodates this features is the opening 52 in top panel 44. It should be understood, although not shown in Figure 2, that a similar opening exists in bottom panel 46 which again is configured to allow a removable cover plate to be attached thereto.
As mentioned above, each library module includes the ability to house and manipulate a 20 number of media storage elements. It will be understood that the present invention is not limited to any specific type of storage media, and could be implemented with any media type, such as magnetic tape, and storage disks, including optical, magneto optical, magnetic disks, etc. Traditionally, the library includes a number of storage locations or storage bins, at least one media drive for reading the storage media, and pickers/placer mechanisms to transport the 25 storage media. Additionally, some mechanism is typically necessary to allow media to be inserted or imported into the library module for use.
Referring now to Figure 3 and 4, there are shown a top view of first library module 22 with the top panel 44 removed. Further, shown in Figure 4 is a sectional view showing certain interior components of first library module 22 shown from section line 4-4 of Figure 3.
30 As mentioned above, library, module 22 includes a media storage drive 70 along with a storage bin 72 which is configured to have a plurality of storage slots 74 therein. Also contained within first library module 22 is a picker/placer mechanism 80 which is configured to transport media elements from storage slots 74 to media drive 70. Picker/placer 80 travels along a guide rail 82 located along a back portion of library module 22. An import mechanism 86 is provided
at a front portion of library module 22. Import mechanism 86 allows library module 22 to be populated by receiving and appropriately placing media elements within first library module 22.
This involves a coordinated effort between picker/placer 80 and the library module controller (not shown) to appropriately receive and place media elements in the desired storage slot 74.
5 The library modules of the present invention are easily incorporated into a storage library system which can include multiple library modules. In the embodiment shown in Figure 1, three such library modules are utilized. In order to incorporate these multiple modules into one library system, accommodations are made to allow a media transport to carry media elements between the various modules. In order to accomplish this, an elevator system 100 is incorporated into 10 the library system. As can be seen in Figures 3 and 4, library system 100 is positioned adjacent storage bin 72 so as to easily cooperate with picker/placer 80. As can be anticipated, this allows picker placer 80 to remove the particular storage media carried by elevator system 100 and place it in a desired storage slot 74, or directly to media drive 70.
Referring now to Figures 5-7, elevator system 100 is shown in more detail. At a general 15 level, elevator system 100 includes a support track or support rail 102 which is rigidly attached to the housing 40 of library module 22. Elevator system 100 also includes a climber or elevator 110 which is adapted to interact with elevator support track 102. Climber 110 includes a drive motor 112 and related gearing 114 which is designed to interact or cooperate with related track gears 104. Both motor 112 and gearing 114 are attached to coupling support 116 which is 20 designed to interact with guiding slots 106 in elevator support track 102. More specifically, a number of tabs or protrusions 118 are specifically designed to fit within guiding slots 106 as climber 110 travels along elevator support track 102.
Attached to coupling support 116 is a media transport bin 130 which is configured to receive and transport the particular storage media being used in library system 20. In this 25 particular embodiment, media transport bin 130 is configured to receive and carry a magnetic tape cartridge. Media transport bin 130 has a substantially rectangular housing forming a rectangular opening 132 therein.
On a backside of coupling support 116 is located a controller housing 140 which contains an elevator controller 142 and communication devices 144. Controller 142 will direct the 30 operation of elevator system 100 and achieve appropriate movement and direction. Figure 8 is a schematic drawing illustrating the electrical connection and control operation for elevator system 100.
As mentioned above, controller housing 140 contains communication devices 144 which provide the necessary link to a library system controller 150 contained within library system 20.
In one embodiment of the present invention, communication is achieved via radio frequency signals transmitted between elevator controller 142 and library system controller 150. Based on the signals received, and programming logic within controller. Library controller 150 obviously includes similar communication device 154. Altemative communication methods could include 5 infrared or visible light signals. While wireless communication is obviously preferable, systems could be incorporated to have wired communication depending on the number of modules included. In order to provide power to motor 112 and controller 142, power connections are provided on coupling support 116. Specifically, a first power connector 160 and a second power 10 connector 162 are provided. These power connectors interact with power strips incorporated into elevator track 102. More specifically, elevator rail 102 includes a first power slot 122 and a second power slot 124. These power slots contain conducting material which provide the necessary power signals to the elevator 100. As expected, this would traditionally include a ground signal and a positive power supply signal.
15 Referring again to Figure 1, it can be seen that the various library modules (i.e., hrst library module 22, second library module 24 and third library module 26) are all located relatively close to one another. With the appropriate housing openings 52 aligned with one another, and the common geometry of the various library modules, elevator system 100 is capable of transporting storage media between the various library modules. As mentioned above, the 20 configuration of the various library modules causes each elevator track 102 to be aligned with one another. Consequently, multiple elevator tracks 102 aligned with one another would create a semi-continuous rail system along which elevator 110 could travel. Naturally, some gaps exist between the various elevator tracks 102. The ability to bridge these gaps is achieved by the configuration of gears 114 and coupling support 116. More specifically, gears 114 includes a 25 drive gear 170, a first travel gear 172 and a second travel gear 174. As can be seen in Figure 7, hrst travel gear 172 and second travel gear 174 are spaced a distance apart. In practice, this distance is sufficient to allow elevator system 110 to bridge any existing gap between the various library modules. Similarly, coupling support 116 is sufficient in size and configuration to bridge the existing gaps.
30 The step of bridging gaps between library modules is further illustrated in Figure 8. More specifically, an elevator support track 110 for first library module 22 and a elevator library track 110 for second library module 24 are shown. As can be seen, the elevator support rails 110 are aligned with one another and closely spaced to allow consistent travel of elevator 110.
As can be seen, the top panel 44 of first library module 22 is adjacent the bottom panel 46 of second library module 24. The rack mounted systems are designed and configured so that a minimum distance exists between these two library modules when appropriately mounted. This minimizes the gap that elevator 110 must bridge during its travel between modules.
5 Coupling support 116 is sized to be substantially larger than the gap which must be bridged during this operation. Consequently, during any point in travel coupling support 116 will be sufficiently coupled with elevator support track 102 so that its movement is closely guided.
Additionally, first travel gear 72 and second travel gear 74 are sufficiently spaced so that at least one travel gear will continuously be engaged with the gears 104 on elevator support track 102.
10 As can be seen from this figure, the movement of elevator 110 across the gap is easily achieved through the appropriate placement and configuration of components - specifically first travel gear 172, second travel gear 174, and coupling support 116.
In operation, the elevator will be largely controlled by the library controller 150. A schematic drawing of the control system is shown in Figure 9. When library controller 150 15 determines it is necessary for a cartridge to be moved from one module to another, appropriate communication signals will be transmitted via library communication device 154 to elevator controller 142. Upon receipt of such signals, elevator controller 142 will cause motor 112 to be appropriately actuated, thus causing the movement of elevator 110. Elevator controller 142 will then cause elevator 110 to proceed to the desired location. In the library system, at least one 20 proximity switch 146 may be utilized to control the precise positioning of elevator 110. Once at position, library controller 150 will actuate the related systems, such as picker/placer 80, causing the appropriate movement of storage media. This may include the placement of a storage cartridge within media transport bin 130, or, the removal of a storage cartridge therefrom. 25 In order to provide necessary communication, elevator controller 142 will provide appropriate signals back to library controller 150, indicating that elevator 110 is in an appropriate position. Likewise, other information could be communicated back to the library controller, such as cartridge information, etc. For example, each cartridge could include an identifier which could be read by a sensor on the elevator. This could then be communicated 30 back to library controller 150. Example identifiers may include bar codes, REID chips, etc. While a proximity switch 142 is mentioned above, it is understood that positioning of elevator 110 could be accomplished via several mechanism. For example, tracking of motor operation would also allow positioning of elevator 110. Further, micro- switches or optical sensors could also be utilized.
Those skilled in the art will further appreciate that the present invention may be embodied in other specific forms without departing from the central attributes thereof. In that the foregoing description of the present invention discloses only exemplary embodiments thereof, it is to be
understood that other variations are contemplated as being within the scope of the present 5 invention. Accordingly, the present invention is not limited in the particular embodiments which have been described in detail therein.