Abstract:
An apparatus and system for handling and storing a plurality of data storage discs includes a toroidal configuration of storage locations for the discs, a plurality of disc drives mounted above the storage locations in a generally annular arrangement, a means for moving any disc into and out of each selected drive on demand, and a control means for directing operation of the means for moving the discs and controlling selection of operation of the disc drives. The apparatus also has another plurality of data storage discs in a secondary module comprising another torodial configuration of storage locations for the discs mounted below the first plurality, a means for moving any disc between the two pluralities of storage locations, and a control means for directing the movement of the discs. The apparatus also has a supplies module mounted beneath the secondary module and houses the power supplies and environmental control equipment necessary for the system. The apparatus includes a access port for the loading and unloading of discs by the user and control means for directing the loading and unloading of discs.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to data storage devices and systems, and more particularly to a data disc library apparatus utilizing multiple removable disc drives and multiple removable disc media arranged in an annular configuration. 
     2. Description of Related Art 
     A typical digital data tape cartridge handling library includes number of columns of stacked bins containing data tape cartridges positioned around a centrally located manipulating arm with a cartridge grasping hand which can rotate, translate and elevate to position the hand in front of a particular bin containing the desired cartridge. 
     Multiple compact audio disc (CD) and digital video disc (DVD) storage and handling apparatuses are also known. Some disc storage apparatus configurations are toroidal and some are linear stacks. Representative examples of such read only Jukebox disc changers are disclosed in U. S. Pat. Nos. 5,644,558; 5,235,579; 5,886,974; 5,307,331; 5,274,620; 4,567,584; 4,734,814; 3,008,721; and WIPO publication No. WO87/07423. 
     These apparatuses are all directed to the handling of discs or cartridges one at a time. This requires a substantial time period of drive inactivity while a disc is unloaded or loaded between the library storage and the drive. In the case of tape cartridge libraries, this delay is compensated for by having several drives being accessible to the manipulator apparatus. However, in the handling of digital data, especially where the reading and writing of critical data is involved, speed of access to data is important and the simultaneous handling of multiple data storage cartridges may be desirable. 
     In the case of optical digital media, the random access speed is currently limited typically to between 100 ms to 200 msec. However, large amounts of data can be stored on these discs such as currently up to about 17 gigabytes of data. Currently only 1 to 4 drives have been used in jukebox type CD and DVD devices and these are read only devices. Thus access speed is extremely limited for data handling purposes. Accordingly there is a strong need for an apparatus that overcomes the limitations posed by current CD and DVD access times in order to make the optical disc media suitable for data intensive operations, such as in the terabyte range, which is reliable, low cost, and compact. 
     It is with respect to these and other considerations that the present invention is made which utilizes conventionally available read and writable (R for WORM or RW, or RAM) CD and future DVD drives and conventional optical disc media combined into a new configuration. 
     SUMMARY OF THE INVENTION 
     The present invention is an apparatus for handling and storing a plurality of removable digital data storage modules, e.g. tape cartridges or discs. The apparatus comprises a toroidal configuration of storage locations for the discs or cartridges, a plurality of disc or cartridge drives mounted adjacent to the storage locations in a generally annular arrangement, a means for moving any disc or cartridge into and out of each selected drive on demand; and a control means for directing operation of the means for moving the discs or cartridges and controlling selection and operation of the disc drives. 
     More particularly, the apparatus in accordance with a preferred embodiment the present invention comprises a stationary frame, a rotating frame or “carousel” mounted on the stationary frame supporting a number of data discs in a toroidal configuration for rotation about a central axis. A plurality of drives are mounted to the stationary frame in an annular configuration above the carousel. A motor is operably connected between the stationary frame and the carousel for rotation of the carousel about the central axis. Beneath each disc drive is a lift mechanism comprised of a lift finger operably extending below the carousel and a motor to raise and lower the arm. The lift mechanism operates to vertically lift a data disc positioned beneath the disc drive into an opening in the drive and receive and lower a disc ejected from the drive. A disc access port in the drive module is preferably provided for manual loading of one or more discs into the carousel. A controller is operably connected to each of the lift mechanisms and to the carousel motor which controls alignment of the carousel, and insertion and removal of the disc from any one of the disc drives in accordance with a demand schedule from a library controller. The library controller manages and coordinates the operation of the disc drives, the lift mechanisms and the operation of the carousel to cue the discs to the desired drives. 
     Further, a secondary rotating carousel and a secondary storage transfer mechanism is preferably provided for additional storage capacity. The secondary carousel is mounted to the stationary frame below the first, or primary, carousel and a drive motor is operably connected between the stationary frame and the secondary carousel for independent rotation of the carousel about the central axis. The secondary carousel also supports a number of data discs in a toroidal configuration for rotation about the central axis. The secondary storage disc transfer mechanism or passthrough device is fastened to the stationary frame and has a lift finger which operably moves discs between the primary and secondary carousels. The passthrough device vertically lifts a data disc and transfers it from the lower, secondary carousel to the uppers primary carousel. The library controller is operably connected to the passthrough device, the carousel motor that controls alignment of the secondary carousel, and insertion and removal of the disc from the primary carousel in accordance with a demand schedule from a library controller. The present invention is particularly applicable to the manipulation of removable media, without any caddy, or specific media protection or enclosure. It also take advantage of the standard φ120 mm, 1.2 mm thick media used for CD-x and DVD-x. 
     These and various other features as well as advantages which characterize the present invention will be apparent from a reading of the following detailed description and a review of the associated drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a functional block diagram of the control system for the apparatus in accordance with the present invention. 
     FIG. 2 is an upper perspective cut away view of the apparatus in accordance with the present invention showing the disc drives, the disc access port transfer device, the disc passthrough device and the primary storage disc carousel. 
     FIG. 3 is a lower perspective cut away view of the apparatus in accordance with the present invention showing the disc drives, the disc access port transfer device, the disc passthrough device, the primary storage disc carousel and some of the primary storage disc transfer mechanisms. 
     FIG. 4 is a schematic vertical sectional view of the apparatus in accordance with the present invention shown in FIGS. 1 and 2. 
     FIGS. 5 and 6 are plan and section views, respectively, of a storage disc with disc protection rings. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Throughout this description, reference is made to a data storage disc and disc drive modules. These are one type of removable digital data storage units or complementary drive modules. It is to be understood that “disc” and “disc drive” as used herein applies equally well to tape cartridges and tape cartridge drive modules and thus, the terms “tape cartridge” and “cartridge drive” may be substituted for “disc” and “disc drive” throughout the following detailed description. 
     A section view of a preferred embodiment of the present invention involving removable data storage discs, is presented in FIG.  4 . This preferred embodiment is a data storage disc handling apparatus or system  100  including of a disc drive module  102 , a primary storage disc module  104 , a secondary or long term storage disc module  106 , and a supplies module  108 . Although the modules can be installed in any shape cabinet  110 , in the preferred embodiment the modules are installed in a standard  19 ″  18 U cabinet  110  and are stacked vertically one on top of the other with the disk drive module  102  on top, the primary disc storage module  104  below it, the secondary storage disc module  106  below the primary storage disc module  104  and the supplies  108  module at the bottom. 
     The drive module  102  includes of a stationary frame  112  upon which is fastened a plurality of disc drives  114 , and the library controller electronics  116 . The drives  114  are installed in a vertical configuration with the disc entrance slot  118  facing down to receive data storage discs  120  from the primary storage disc module  104  below it. The drives  114  are arranged in a circle around and spaced from a central vertical axis  122 . As shown in FIG. 2, the drive module  102  has eighteen separate positions or “bays” for drives  114  spaced equally around the central axis  122 . Drives can be mounted either all in the same or half reversed (180°) position, so that dual sided media can be handled, since—in most existing drives, especially DVD—one drive can access only one side of the media. FIG. 2 shows sixteen drives  114  installed. One drive bay is reserved for a secondary storage disc passthrough device  126  and one drive bay is reserved for a disc access port  128 . The stationary frame  112  can be made of steel, aluminum or other structural support material and allows for the positive attachment of the drives  114  to the frame  112 . The center region  132  within the drive module  102  physically contains the library controller electronics  116  and may have portions of the primary storage disc transfer mechanisms  134  and the secondary storage disc passthrough mechanism  146  which are discussed below. 
     The drives  114  are of the “slot-in” type that do not have an extending disc cradle or caddie. The use of slot-in drives is not mandatory, however this reports the disc grasping mechanism into the drive. A disc  120  is loaded vertically into a slot-in drive  114  by partially raising the disc  120  into the entrance slot  118  of the drive  114  from below. An internal grasping mechanism pulls the disc  120  into position within the drive. For ejection, the internal grasping mechanism lowers the disc  120  out of the drive  114  where it is received by the primary storage disc transfer mechanism  134 . The transfer mechanism then returns the disc  120  to the primary storage disc module  104 . The drives  114  are connected and are controlled by to the library controller  116  via EIDE, SCSI, USB or similar standard interface cables  140 . 
     The secondary storage disc passthrough device  126  can be a disc drive  114  or, as in the preferred embodiment, a simpler passthrough-specific device  126  that&#39;s only purpose is to temporarily store a disc  120  to be transferred from the secondary storage disc module  106  to the primary storage disc module  104  or vice versa. The passthrough device  126  is fastened to the stationary frame  112  of the drive module  102  in a drive bay in the same manner as a disc drive  114 . The passthrough device  126  is a slot-in device similar to the disk drives  114  and a disc  120  is loaded vertically into the passthrough device  126  by partially raising the disc  120  into the entrance slot  118  of the device  126  from below. An internal grasping mechanism pulls the disc  120  into position within the device  126 . For ejection, the internal mechanism lowers the disc  120  out of the device  126  where it is received by the secondary storage disc passthrough transfer mechanism  146 . The passthrough transfer mechanism  146  then places the disc into an empty disc slot  148  in either the primary  104  or secondary  106  storage disc module. The passthrough device  126  is connected to and controlled by the library controller  116  via EIDE, SCSI, USB or similar standard interface cables  140 . 
     The disc access port  128  allows external access to storage discs  120  for manual loading, unloading and inspection of the discs  120 . The disc access port  128  includes of a removable cartridge (not shown) which typically may have up to eight or more slots to receive up to eight or more discs  120  and is a transfer device into which the cartridge is loaded, for transferring discs  120  from the cartridge into the primary storage disc module carousel  156  and vice versa. The access port  128  has the same internal slot-in mechanism as does each of the disc drives  114  which transfers discs  120  between the cartridge and the primary storage disc transfer mechanism  134 . 
     Discs  120  are loaded into the access port  128  from the primary storage disc module  104  in order to remove discs  120  from the system  100  by partially raising the disc  120  into the entrance slot  118  to the port  128  from below. An internal mechanism pulls the disc  120  from the primary storage disc transfer mechanism  134  and positions it in the removable cartridge. The port  128  is fastened to the stationary frame  112  of the drive module  102  in a drive bay in the same manner as a disc drive  114 . The drive bay designated for the port  128  is provided with an opening in the stationary frame  112  and system cabinet  110  through which the cartridge can pass. The disc access port  128  is connected to and controlled by the library controller  116  via EIDE, SCSI, USB or similar standard interface cables  140 . 
     The primary storage disc module  104  is installed directly beneath the stationary drive module  102  and includes a stationary frame  124 , a carousel  156 , a mechanism for carousel rotation which is internally mounted to the stationary frame  124  and a primary storage disc transfer mechanism  134 . The carousel  156  is rotatably mounted to the stationary frame  124  which is mounted to the frame  112  of the disc drive module  102  and rotates on bearings about the central axis  122 . The carousel rotating mechanism is a motor  166  fastened to the stationary frame  124  and geared to a planetary gear  130  on the base of the carousel  156 . The motor  166  is connected to and controlled by the library controller  116  via EIDE, SCSI, USB or similar standard interface cables  140 . 
     The carousel  156  has of two concentric, tubular walls  172 ,  176  between which discs  120  are stored. Discs  120  are stored vertically in radial positions about the central axis  122  and arranged in a toroidal configuration so that they can be lifted directly upward into the drives  114 . The walls do not move independently and are connected to each other in a way that does not interfere with the lifting of the discs  120  into the drives  114 . The inside of outer wall  172  and the outside of the inner wall  176  contain slots  148  to hold the edges of the discs  120  vertically in place. Discs  120  are prevented from falling down through the carousel  156  by stop rings  180  installed around the base of the slots  148 . During storage, the discs  120  rest in slots  148  between the two walls  172 ,  176  of the carousel  156  on the stop rings  180  with between one-third and one-half of the disc  120  extending below the bottom of the inner wall  176  of the carousel  156 . In the preferred configuration there may be  288  disc slots  148  in the carousel  156 . 
     Two disc slots  148  on the carousel  156  are reserved for storage disc passthrough from the secondary storage disc module  106  to the drive module  102 . The stop ring  180  have openings at the passthrough slot  136  so that a disc  120  from the secondary storage disc module  106  can be lifted from the secondary storage disc module  106  through the passthrough slot  136  of the primary carousel  156  and into the passthrough device  126  in the drive module  102 . 
     FIG. 3 is a lower perspective view which shows the elements of FIG. 2 as well as a some of primary storage disc transfer mechanisms  134 . There is one primary storage disc transfer mechanism  134  for each drive  114  and one for the disc access port  128 . Each of the transfer mechanisms  134  operably lift a disc  120  into and receive a disc  120  from its associated disc drive  114  or disc access port  128 . Each transfer mechanism  134  includes of an “L”-shaped, lift finger positioned directly beneath an opening  118  to a drive  114  or the disc access port  128 . While not in operation, the lift fingers  184  are parked below the stored discs  120 . A stem  186  of each lift finger  184  is vertically oriented between the inner wall  176  and the central axis  122  and adjacent to the inner wall  176  allowing the primary carousel  156  to rotate freely and position any disc slot  148  beneath the disc entrance slot  118  to any drive  114 , the passthrough device  126  or the disc access port  128 . The primary transfer mechanism  134  locks the position of the primary carousel  156 , preferably by the lift finger  184  but it could be achieved by a separate specific locking mechanism. A lift finger motor  190  for each lift finger  184  is positioned next to and is attached to each lift finger stem  186  and raises and lowers the lift finger  184  to insert a disc  120  into and receive a disc  120  from its associated drive  114  or access port  128 . Each motor  190  is separately controlled and operates independently from the other motors  190 . The lift motors  190  are connected to and controlled by the library controller  116  via EIDE, SCSI, USB or similar standard interface cables  140 . 
     The secondary storage disc module  106  is installed directly beneath the primary storage disc module  104  and includes a stationary frame  222 , a carousel  194 , a mechanism for carousel rotation and a secondary storage disc passthrough transfer mechanism  146 . The secondary storage disc module  106  is used as long term storage of discs  120  that are not frequently used. The carousel  194  is rotatably mounted to the stationary frame  222  which is mounted to the frame of the primary storage disc module  104  and rotates on bearings about the central axis  122 . The carousel rotating mechanism is a motor  196  fixed to the stationary frame  222  and geared to a planetary gear  130  on the base of the carousel  194 . The motor  196  is connected to and controlled by the library controller  116  via EIDE, SCSI, USB or similar standard interface cables  140 . 
     The carousel  194  includes of two concentric, tubular walls  200  and  204  between which the discs  120  are stored. Discs  120  are stored vertically in radial positions about the central axis  122  and arranged in a toroidal configuration so that they can be lifted directly upward. The walls  200  and  204  do not move independently and are connected to each other in a way that does not interfere with the lifting of the discs  120  into the drives  114 . The secondary carousel  194  has slots  148  to hold the edges of discs  120  between the inner and outer walls in the same manner as the primary carousel  156 . Discs  120  are prevented from falling down through the carousel  194  by stop rings  206  installed around the base of the slots  148 . During storage, the discs  120  rest in slots  148  between the outer wall  200  and inner wall  204  of the carousel  194  on the stop rings  206 . In the preferred configuration there may be  288  disc slots  148  in the carousel  194 . 
     The secondary storage disc passthrough transfer mechanism  146  transfers a disc  120  between the secondary disc storage carousel  194  and the secondary storage disc passthrough device  126 , through the passthrough slot  136  in the primary disc storage carousel  156 . The passthrough transfer mechanism  146  is also capable of transferring a disc  120  between the primary storage disc carousel  156  and the passthrough device  126 . The passthrough transfer mechanism  146  is attached to the stationary frame  222  beneath the passthrough device  126 . When not in operation, the mechanism  146  is parked between the inner wall  204  and the central axis  122  allowing the primary  156  and secondary  194  carousels to rotate freely. The passthrough transfer mechanism  146  locks the position of the primary carousel  156  and the secondary carousel  194  when transferring a disc. The passthrough mechanism motor  210  is connected to and controlled by the library controller  116  via EIDE, SCSI, USB or similar standard interface cables  140 . 
     Discs  120  in the secondary storage disc module  106  must be transferred to an empty slot  148  the primary carousel  156  before they can be read. To achieve this, the following steps are followed: 
     1. The desired disc  120  in the secondary storage disc carousel  194  is aligned directly beneath the passthrough device  126  in the drive module  102 ; 
     2. The passthrough slot  136  in the primary storage disc carousel  156  is aligned directly beneath the passthrough device  126  in the drive module  102 ; 
     3. The secondary storage disc passthrough transfer mechanism  146  lifts the disc  120  from the secondary carousel  194 , through a passthrough slot  136  in the primary carousel  156  and partially inserts it into the passthrough device  126 ; 
     4. The internal slot-in mechanism of the passthrough device  126  grabs the disc  120  and loads it into the device  126  for temporary storage; 
     5. The primary storage disc carousel  156  is rotated to align the selected empty disc slot  148  directly beneath the passthrough device  126 ; 
     6. The passthrough device  126  ejects the disc  120  which is received by the passthrough transfer mechanism  146 . 
     7. The passthrough transfer mechanism  146  lowers the disc into the slot  148  on the primary storage disc carousel  156 . 
     Once in the primary carousel  156 , a disc  120  can be read in any drive  114  or removed via the disc access port  128 . A disc  120  from the primary carousel  156  can be transferred to the secondary storage disc carousel  194  by reversing the steps outlined above. 
     All primary storage disc transfer mechanisms  134  and the secondary storage disc passthrough mechanism  146  are equipped with disc sensors, preferably optical reflective sensors, which verify the absence or presence of a disc  120  in carousel slots  148  before transfer is initiated to avoid erroneous loading and unloading of discs  120 . Preferably the sensors are designed to detect the signature of a passthrough slot  136  in the primary carousel  156 . Each carousel is provided with a carousel position sensor which monitors the carousels&#39; step position. All sensors are operably connected to the library controller  116  which continuously monitors the state of the system  100  as a whole and the state of each component in the system  100 . 
     The supply module  108  beneath the secondary storage disc module  106  encloses power supplies  218  for the disc drives  114  and library control electronics  116  and the environmental control equipment  220  including the blowers  240  for the system  100 , and the air filters to avoid dust that could disturb operation of the optical storage system. 
     FIG. 1 is a block diagram of the control system for the system  100 . The library controller  116  coordinates and monitors the operation of the drives  114 , motors  166 ,  190 ,  196 ,  210 , carousels  156 ,  194 , and other devices in the system  100 . It also manages the communication of data between the user and the library and the external interface. The controller  116  includes an internal hard disc cache  224  and a library database  226  to speed communications and system response time. 
     The controller  116  can be connected to external equipment via EIDE, SCSI, USB, Ethernet or other standard external connectors  140  which are connected to the controller&#39;s communication bus  228 . The controller  116  is connected to the drives  114  by a dedicated drive interface bus  230  utilizing standard EIDE, SCSI, USB or other connections  140 . The library controller  116  is connected to the other equipment in the system  100  by a separate serial interface bus  232 . This serial bus  232  is connected to the primary carousel  156 , the secondary carousel  194 , and the carousel position sensors through a carousel servo interface  234 . The serial bus  232  is connected to the passthrough device  126  and the passthrough transfer mechanism  146  through a passthrough interface  236 . The serial bus  232  is connected to the primary disc transfer mechanisms  134  and the disc sensors through a finger servo interface  238 . The serial bus  232  is directly connected to the power supplies  218 , the environmental control equipment  220  and blowers  240 , and the disc access port  128 . 
     The data storage disc  120  used in the system  100  are flat, annular disc bodies with a central aperture  248 , an outer rim portion  244 , and a data storage portion  246  that has been impregnated with a storage material as shown in FIG.  5  and FIG. 6, although the system  100  can be configured to use any similar types of storage media such as CDs, DVDs, or CD-ROMs that fit into a standard 5.25 inch format disc drive  114 . The central aperture  248  provides a space for the insertion of a spindle for rotation and alignment within the drives  114  or other devices in the drive module  102 . 
     Both sides of the discs  120  have an inner protective band  242  and an outer protective rim  244 . The band  242  and the rim  244  can be made of metal or some other material, including the same material as the disc  120 . The inner band  242  is adhered to the surface of the disc between the data storage surface  246  and the central aperture  248 . The outer rim  244  is adhered to and covers the outer rim portion of the disc  120 . In the present embodiment, the protective rim  244 , is one piece of material that wraps around the edge of the disc  120 , thus completely covering the outer rim portions of both sides of the disc  120  and the outer edge of the disc  120 . 
     The purpose of the protective band  242  and protective rim  244  is to prevent damage to the data storage surface  246  of the disc  120  through contact with other discs  120  when they are stacked together or otherwise in contact. Furthermore, the outer protective rim  244  protects the disc  120  from damage through contact with the primary carousel  156 , the secondary carousel  194 , the primary transfer mechanism  134 , the secondary passthrough transfer mechanism  146 , the drives  114 , the passthrough device  126 , or the access port  128 . 
     The above specification, examples and data provide a description of the apparatus, system and method of the invention. Since many embodiments of the invention can be made without departing from the spirit and scope of the invention, the invention is defined by the following claims.