Abstract:
The half-inch tape drive comprises a novel takeup reel, tape deck, PC board packaging, loading mechanism, and housing. The takeup reel comprises a pair of segmented flanges that define a first and second tape containment section. The tape deck is approximately half the height of a conventional tape deck and includes reinforcing ribs to provide structural rigidity and maintain alignment of the moving components of the tape drive during operation. The loading mechanism comprises a horizontally mounted load motor that employs a worm gear to engage a simplified gear train. The printed circuit board is segmented into multiple sections that are mounted in various locations on the tape drive to maximize spatial efficiencies and reduce the overall height of the tape drive. The tape drive housing provides a protective exterior for the tape drive components and provides the structure for mounting the present tape drive in a single drive bay of a computer housing.

Description:
FIELD OF THE INVENTION 
     The invention relates to digital tape drive storage devices, and in particular, to a half-inch tape drive having a half high form factor. 
     PROBLEM 
     Tape drives have been widely employed in industry for over thirty years due to their ability to store large amounts of data on a relatively small inexpensive removable format. The data is stored on tape drives utilizing a variety of designs, but in all cases, magnetic tape media is wound between a pair of tape reels as data is transferred to or from the tape media. The standard tape media employed in many applications is a one half-inch wide tape media housed in a tape cartridge measuring at or near 1 inch in height. Presently, all tape drives that utilize half-inch tape media are constructed in a full height five and a quarter (5.25) inch or larger form factor as defined by: EIA specification No. 3877-A “Small Form Factor 133.35 mm (5.25) Disk Drives.” One example of a full height five and a quarter (5.25) form factor for tape drives includes a width dimension “W” of 5.75 inches a depth dimension “D” of 8.1 inches and a height dimension “H” of 3.2 inches. Therefore, half-inch tape drives occupy two drive bays when installed in a conventional computer housing. 
     In the art of data storage, the physical space required to store data is an important concern. Thus, it is desirable to have a half-inch tape drive that is constructed with a half height form factor that can be installed in a single drive bay in a conventional computer housing. The half height form factor, also defined in EIA specification No. 3877-A “Small Form Factor 133.35 mm (5.25) Disk Drives” includes a maximum height of 1.634 inches. Unfortunately, in addition to the fact that half-inch tape cartridges are approximately 1 inch by themselves, several other design requirements make achieving a half-height form factor in a half-inch tape drive extremely difficult. 
     FIG. 1 illustrates one example of a typical half-inch tape drive  100 . The tape drive  100  is a DLT tape drive that employs a single reel DLT tape cartridge design. This design includes a supply reel located within a tape cartridge (not shown) and a takeup reel  101  located within the tape drive  100 . Referring to FIG. 2, the tape media on the tape cartridge is terminated at one end by a tape cartridge leader  201 . The tape cartridge leader  201  is a strong flexible plastic strip containing an ovular aperture  202  on its distal end. A takeup leader  203 , that connects to the takeup reel  101 , is a similar plastic strip that includes a stem  204  and tab  205  designed to buckle with the ovular aperture  202  on the tape cartridge leader  201  to form buckle  200 . The tape cartridge leader  201  also includes a section  206  that is slightly wider than the rest of the tape cartridge leader  201  and the takeup leader  203 . The wider section  206  prevents the tape cartridge leader  201  from being pulled into the tape cartridge after the tape cartridge leader  201  and takeup leader  203  are disconnected for ejection of the tape cartridge. 
     Upon loading the tape cartridge into the tape drive  100 , the takeup leader  203  and tape cartridge leader  201  are buckled, and the tape media is wound to a start point or read position. To accommodate the slightly wider section  206  during winding of the tape cartridge leader  201  and the takeup leader  203  around the takeup reel  101 , the takeup reel  101  includes a wider stepped area  102  formed in the top and in the bottom flanges,  112  and  113 , of the takeup reel  101 . Unfortunately, the stepped area  102  adds approximately a quarter of an inch to the height of the takeup reel  101  and the overall height of the tape drive  100 . 
     Another design requirement in half-inch tape drives is the physical size of the tape deck  109 . The tape deck  109  functions as a supporting surface for the various mechanical and electrical components, such as the takeup reel  101 , tape guides  103 - 106 , the read/write head  107  and the printed circuit board (“PC”)  108  mounted on the underside of the tape deck  109 . To maintain an accurate alignment of the takeup reel  101 , tape guides  103 - 106  and the read/write head  107 , during operation of the tape drive  100  requires a rigid tape deck  109 . To achieve the necessary rigidity in the tape deck  109 , typical DLT tape drive decks are approximately one (1) inch in height. Additionally, the PC board  108  is mounted on the underside of the tape deck  109  further adding to the overall height of the tape deck  109  and the tape drive  100 . 
     Finally, another design requirement in half-inch tape drives is the loading mechanism that engages the tape cartridge drive mechanism  110  through a toothed coupling. The loading mechanism comprises a vertically mounted load motor  111  coupled to a spur gear train (not shown) that engages the cartridge drive mechanism  110 . Unfortunately, the load motor  111  is mounted vertically in order to engage the gear train and move the cartridge drive mechanism  110  vertically up and down to engage and disengage the tape cartridge reel when a tape cartridge is inserted into the tape drive  100 . The vertically mounted load motor  111  again adds to the overall height of the tape drive  100 . 
     SOLUTION 
     The present invention overcomes the problems outlined above and advances the art by providing a half-inch tape drive that is implemented in a half height form factor. A first advantage of the present half-inch tape drive is that it accommodates conventional half-inch tape cartridges. It can be appreciated that not modifying the tape cartridge format represents a significant advantage to consumers whose data is currently stored on half-inch tape cartridges. A second advantage of the present half-inch tape drive is that the half height form factor permits installation of this tape drive in a single drive bay in a conventional computer housing. A third advantage of the present half-inch tape drive is improved manufacturability resulting from the reduction in material and design improvements. Additionally, one skilled in the art will appreciate numerous other advantages of the half-height form factor, such as doubling the storage capacity in a single computer by the accommodation of twice as many tape drives and the additional flexibility added to data storage design. 
     The present half-inch tape drive comprises a novel takeup reel, tape deck, PC board packaging, loading mechanism, and housing. The takeup reel comprises a takeup reel hub connected between a pair of segmented flanges that define first and second tape containment sections. The tape deck is approximately half the height of a conventional tape deck and includes reinforcing ribs that provide structural rigidity to maintain alignment of the moving components of the tape drive during operation. The tape deck also includes a plurality of guiding ribs that cooperate with the takeup reel to vertically align the tape media in the tape path during power interruptions. The loading mechanism comprises a horizontally mounted load motor that connects to a simplified gear train. A worm gear provides the connection between the load motor and the gear train and permits the horizontal mounting of the load motor. The PC board packaging comprises a first PC board section mounted in a first location, a second PC board section mounted in a second location and a third PC board section mounted in a third location on the tape drive. The separate PC board sections and mounting locations maximize spatial efficiencies and reduce the overall height of the tape drive. The first, second, and third PC board sections are electrically connected by flex cables that further improve the spatial utilization in the tape drive. The tape drive housing provides a protective exterior for the present tape drive and provides the structure for mounting the present tape drive in a single drive bay of a computer housing. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 illustrates an example of a prior art half-inch tape drive; 
     FIG. 2 illustrates an example a buckle connection between a tape cartridge leader and a takeup leader; 
     FIG. 3 illustrates an example of a half-inch tape drive having a half height form factor according to the present invention; 
     FIGS. 4 and 5 illustrate an example of a takeup reel for a half-inch tape drive having a half height form factor according to the present invention; 
     FIGS. 6 and 6 a  illustrate an example of a loading mechanism for a half-inch tape drive having a half height form factor according to the present invention; 
     FIG. 7 illustrates a prior art loading mechanism for a prior art half-inch tape drive; 
     FIG. 8 illustrates a tape deck for a half-inch tape drive having a half height form factor according to the present invention; 
     FIGS. 9A and 9B illustrate a PC board packaging configuration for a half-inch tape drive having a half height form factor according to the present invention; and 
     FIGS. 10A and 10B illustrate a housing for a half-inch tape drive having a half height form factor according to the present invention. 
    
    
     DETAILED DESCRIPTION 
     Half Height Form Factor FIG. 3 
     For purposes of illustration and not of limitation, various features and advantages of the present invention will now be described within the context of a single reel half-inch DLT tape drive. It is to be understood that the following description with respect to a DLT tape drive is not intended to limit the scope of the present invention. It would be obvious to one skilled in the art that the principles of the present invention could be easily applied to other tape drive formats to construct a tape drive with a half high form factor. 
     FIG. 3 depicts an example of a half-inch tape drive  300  having a half height form factor according to the present invention. Referring to FIG. 10 a,  illustrating an assembled half inch tape drive with a half height form factor, the half height form factor of the tape drive  300  complies with the EIA specifications for half height disk drives as given in EIA specification No. 3877-A “Small Form Factor 133.35 mm (5.25 in) Disk Drives.” The half-inch tape drive  300  of the present invention includes a height “H” of 1.625 inches, a width “W” of 5.75 inches, a depth “D” of 8.1 inches, and fits into a single drive bay in a conventional computer. Referring back to FIG. 3, the tape drive  300  comprises various conventional components such as a tape head  302 , tape guides  303 - 306 , takeup leader catch  307  and positioning lever  308 . However, to achieve the half-height form factor, the tape drive  300  also includes a novel takeup reel  309 , tape deck  301 , load mechanism  310 , PC board packaging and connection (not shown on FIG.  3 ), and housing (also not shown on FIG.  3 ). 
     The Takeup Reel FIGS. 4 and 5 
     Referring to FIGS. 4 and 5, there is shown an example of a takeup reel  309  for the half-inch tape drive  300 . The takeup reel  309  comprises a top segmented flange  404  connected to a top of a takeup reel hub  407  and a bottom segmented flange  406  connected to a bottom of the takeup reel hub  407 . The takeup reel hub  407  could be a conventional takeup reel hub that connects to the tape drive  300  in a conventional manner. This configuration of the take up reel  309  includes a height dimension “X” of no greater than 0.641 inches. 
     The top and bottom flanges,  404  and  406 , are connected in a parallel relationship and form a first tape media containment section  401  and a second tape media containment section  402  on opposing sides of the takeup reel hub  407 . The first tape media containment section  401  and the second tape media containment section  402  guide the half-inch tape media around the takeup reel hub  407  during operation of the tape drive  300 . During the initial winding of the tape cartridge leader  201  and the takeup leader  203 , the wider section  206  of the tape cartridge leader  201 , rests between the first tape containment section  401  and the second tape containment section  402  of the takeup reel  309 . This allows the wider section  206  of the tape cartridge leader  201  to extend slightly above the top and below the bottom of the takeup reel  309  as illustrated by FIG.  4 . 
     Advantageously, this design accommodates the additional height of the tape cartridge leader  201 , while reducing the overall height of the tape drive  300  by eliminating the stepped area  102  of the prior art takeup reel  101 . Also advantageously, eliminating the stepped area  102  permits the top flange  404  and bottom flange  406  of takeup reel  309  to be ultrasonically welded to the takeup reel hub  407 . One skilled in the art will appreciate that this represents a significant advantage over the prior art takeup reel  101 , which includes glued flanges, as the stepped area  102  prevents the cost effective application of the ultrasonic welding technique. 
     A first slot  409 , in the top flange  404 , and a second slot  408 , in the bottom flange  406 , provide for the attachment of the takeup leader  203 . Alternatively, the takeup leader  203  could be attached to the takeup reel  309  in any suitable manner as a matter of design choice. Some examples include without limitation, a single vertical slot on the face  502  of the takeup reel hub  407  that is configured to receive the end of the takeup leader  203  or using a bonding agent to affix the takeup leader  203  to the face  502  of the takeup reel hub  407 . 
     A first rounded protrusion  501  on the underside of the top flange  404  and a second rounded protrusion on the top surface of the bottom flange  406  reduce the spacing in the second tape containment section  402  in a localized area. The reduced spacing operates both to contain the tape media and align the tape media during winding and unwinding from the takeup reel  309 . In alternative embodiments, the first rounded protrusion  501  and the second rounded protrusion  405  could be located on the first flange  404  and the second flange  406 , but in the first tape containment section  401 . Also alternatively, the rounded protrusions  501  and  405  could be included on the first flange  404  and the second flange  406  in both the first and the second tape containment sections  401  and  402 . Advantageously, since highly precise tolerances must be maintained during formation of the rounded protrusions,  501  and  405 , locating the critical spacing defined by protrusions,  501  and  405 , in only one the tape containment sections,  401  or  402 , improves the manufacturability of the takeup reel  309  resulting in lower manufacturing costs. 
     A small post  500  integrally formed on the underside of the bottom flange  406  provides a stop for the takeup reel  309  when a tape cartridge is unloaded from the tape drive  300 . Referring back to FIG. 3, catch  307  includes a hook  315  that engages post  500  to prevent further rotation of the takeup reel  309  when catch  307  is rotated in direction “A” during unbuckling of the tape cartridge leader  201  and the takeup leader  203 . The post  500  replaces the function previously performed by the stepped area  102  on the bottom flange  113  of the prior art takeup reel  101 . 
     Still referring to FIG. 3, tape media supporting ribs  311 - 314  are integrally formed on the top portion of the tape deck  301 . Supporting rib  311  is located between the tape guide  305  and the takeup reel  309  in a perpendicular relationship with the backside of the tape deck  301 . The supporting ribs  312 - 314  are located around tape guide  306  as illustrate by FIG.  3 . The supporting guides  311 - 314  are not required for proper operation of a tape drive according to the present invention, but are relevant to the present invention because they solve a known problem with both the prior art takeup reel  101  and the present takeup reel  309 . 
     The supporting guides  311 - 314  support the tape media during power interruptions in the tape drive  300 . During a power interruption where proper tension is not maintained on the tape media, the tape media can fall vertically off the guide rollers  303 - 306 . In relation to the present takeup reel  309 , the tape media could also fall vertically off of the takeup reel  309  between the first tape containment section  401  and the second tape containment section  402  due to the reduction in support provided by the segmented flanges  404  and  406 . If the tape media is vertically out of position when the tape drive  300  is powered back on, the tape media could be damaged by either the bottom flange  406  or the tape guides  303 - 306  when the tape media is pulled back into position on the takeup reel  309  and tape guides  303 - 306 . Advantageously, the supporting ribs  311 - 314  prevent the tape media from falling vertically out of position during power interruptions. It should be noted, however, that where proper tension is maintained on the tape media during power interruptions, the tape media will not fall vertically off of the takeup reel  309  or the tape guides  303 - 306 . 
     Loading Mechanism FIGS. 6 a,    6   b  and  7   
     FIGS. 6 a  and  6   b  illustrate an example of a loading mechanism  600  for the half-inch tape drive  300  having a half height form factor. The loading mechanism  600  comprises a load motor  601  connected to a gear train  610  by a worm gear  603 . The gear train  610  comprises a helical engagement gear  602  connected to a spur gear  611 . The helical engagement gear  602  mates with the worm gear  603  to drive the spur gear  611 . The spur gear  611  in turn drives a pair of intermediary spur gears,  608  and  609 , which engage the main drive gear  607 . The load motor  601  connects horizontally to a mounting bracket  604  that rivets to a top plate  606 . Alternatively, the load motor  601  could be connected to the loading assembly  600  by any suitable manner that allows the warm gear  603  to mate with the engagement gear  602 . 
     Referring to FIG. 7 depicting a prior art loading mechanism  700 , it can be seen that the top plate  606  has been modified to permit the load motor  601  to be placed closer to the main drive gear  607 . Advantageously, the worm gear  603  and helical engagement gear  602  provide an additional mechanical advantage over the prior art spur gear train allowing for a reduction in the number of gears required to operate the main drive gear  607 . SpecIfically, spur gears  701 - 705  are eliminated from the prior art gear train  706  resulting in a quieter and simpler loading mechanism  600 . 
     Tape Deck FIG. 8 
     FIG. 8 illustrates an example of a tape deck  301  for the half-inch tape drive  300  having a half height form factor. The height “B” of the tape deck  301  is approximately half the height of the tape deck  109  of the prior art tape drive  100 . In an exemplary example of the present invention, the height of the tape deck  301  is in the range of 0.4 to 0.5 inches and more preferably is 0.460 inches. 
     Tape drive decks are typically constructed from aluminum. Thus, to compensate for the loss in rigidity that would normally result from the reduced size of the tape deck  301 , a of reinforcing ribs e.g.  801  are integrally formed in the bottom of the tape deck  301 . Alternatively, other methods could be used to provide the necessary rigidity in the tape deck  301  as a matter of design choice. Some examples include without limitation, the use of a more rigid material in the construction of the tape deck  301  or the use of stiffening members, such as would be provided by a support beam across the bottom of the tape deck  301 . 
     As will become apparent from the following description, the tape deck  301  also includes a circular recessed portion  802  that houses a section of the PC board  803 . Advantageously, the reinforcing ribs  801  provide the necessary structural integrity to maintain accurate alignment of the moving components of the tape drive  300 , such as the takeup reel  309 , tape guides  303 - 306 , tape head  302  and various drive and load motors. Additional features of the tape deck  301  will become apparent from the following description of the PC board packaging. 
     Printed Circuit Board FIGS. 9 a,    9   b,    10   a,    10   b    
     FIGS. 9A,  9 B,  10 A and  10 B illustrate an example of a PC board for the half-inch tape drive  300  having a half height form factor. The size of the prior art PC board  108  required that it either be located on the top of the prior art tape drive  100  or on the underside of the tape deck  109 , as shown in FIG.  1 . To achieve more efficient space utilization, the PC board of the present half-inch tape drive  300  is separated into three segmented sections  803 ,  900  and  901 . Alternatively, those skilled in the art will appreciate that the PC board could be segmented into additional sections as a matter of design choice. 
     The logic board section  901  of the PC board is substantially “L” shaped and connects to the top of the tape drive  300  as illustrated by FIG.  9 B. Advantageously, the logic board section  901  also provides a cover over the internal components of the tape drive  300 , protecting them from dust and other debris. The read/write board section  900  is rectangular in shape and mounts along the side of the tape drive  300 , as illustrated by FIG.  9 B. The logic board section  901  and the read/write board section  900  are connected by a conventional hard connection at joint  906 . 
     The servo board section  803  is substantially circular in shape and mounts in the recessed portion  802  of the tape deck  301 . The servo board section  803  connects to the logic board section  900  by way of a flex cable  902  that passes through a slot  903  in the tape deck  301 . Advantageously, flex cables are also used to connect other components of the tape drive  300 , such as cable  904  that connects to the tape head  905 . It should be noted that while the PC board sections  803 ,  900 , and  901  generally include the circuitry depicted by their names, e.g. logic board section  901 , the various circuitry components could be organized on the PC board sections  803 ,  900 , and  901  in various other configurations as a matter of design choice to accommodate different half-inch tape drive formats. 
     Housing FIGS. 10 a  and  10   b    
     FIGS. 10 a  and  10   b  illustrate an example of a housing for the half-inch tape drive  300  having a half height form factor. The tape drive housing comprises three sections  1001 ,  1002 , and  1003  that enclose the various tape drive components on three sides. Alternatively, the tape drive housing could be a single housing section or two integrally connected sections that are configured to detachably connect to a third section to enclose the tape drive components. The housing sections  1001 - 1003  could be sheet metal, plastic or any other suitable material as a matter of design choice. The tape drive housing also provides the mounting apertures  1004 ,  1005 ,  1006  and  1007  for installation of the tape drive  300  in a conventional computer drive bay. It should also be noted that bottom mounting apertures (not shown) are provided on the underside of the key ways e.g.  911  and  910 . Advantageously, providing the mounting apertures e.g.  1004  in the tape drive housing, rather than in the tape drive deck  301  as done in the prior art, structurally isolates the tape drive  300  from variations in the mounting surface that can cause distortion. Referring back to FIG. 9B it can be seen that the read/write board section  900  also includes apertures  907  and  908  that align with apertures  1004  and  1005  to accommodate the tape drive mounting screws (not shown). 
     Referring to FIGS. 9A,  9 B,  10 A and  10 B, the tape drive housing connects to the tape deck  301  through the use of keys  1008 - 1012  formed on the bottom portion of the housing sections  1001 - 1003  and mating key ways  910 - 914  formed in the respective sides of the tape deck  301 . Advantageously, the housing sections  1001 - 1003  not only protect the tape drive components, but also provide the mounting connection for the logic board section  901  and the read/write board section  900 . The read/write board section  900  is mounted behind and protected by the housing section  1003 . The logic board section  901  is connected to the housing sections by screws located at various points around the top edge of the logic board section  901 . In alternative embodiments, a cover  1013  can also be affixed over the tape cartridge bay  1014  to provide additional protection for tape drive  300  from dust and debris. Cover  1013  could be a sheet metal cover, plastic cover, or any other suitable material as a matter of design choice. 
     Those skilled in the art will appreciate variations of the above-described embodiments that fall within the scope of the invention. As a result, the invention is not limited to the specific examples and illustrations discussed above, but only by the following claims and their equivalents.