Abstract:
An example embodiment provides for an apparatus, for use in a tape drive system, that facilitates adjustment of azimuth and zenith orientations of a magnetic tape head. The apparatus includes a top and bottom plate located above and below an actuator assembly that includes a magnetic head. Also included are first and second ball-ended guide rods that each have ends that mate with corresponding top and bottom plate sockets. Azimuth and zenith adjustment is provided for via at least one azimuth adjustment screw and at least one zenith adjustment screw. Various aspects of the apparatus include independent adjustment of the zenith and azimuth, where adjustments to one does not affect the other. Another aspect includes the top plate remaining in a substantially horizontal plane when either the azimuth or the zenith is adjusted.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
   This application claims the benefit of U.S. Provisional Patent Application No. 60/804,498 filed on Jun. 12, 2006, which is incorporated herein by reference. 

   TECHNICAL FIELD 
   The present invention relates generally to tape drives. 
   BACKGROUND 
   In tape drive systems, magnetic head positioner systems that adjust azimuth and zenith of a magnetic head are well known in the art. Azimuth, of the magnetic head, generally refers to an orientation of the magnetic tape head across or parallel to a tape travel path and zenith generally refers to an orientation of the magnetic head in and out from (perpendicular to) the tape travel path. 
   Some prior art magnetic head positioner systems involve tying one corner of a top plate, of the system, to a bottom plate. Two jack screws and coil return springs are located at other corners of the top plate. One jack screw provides azimuth adjustment by while the other jack screw provides zenith adjustment. Typically, adjusting the zenith jack screw also affects the azimuth setting of the magnetic head to a degree. Similarly, adjusting the azimuth jack screw also affects the zenith setting of the magnetic head to a degree. As a result, achieving a desired azimuth and zenith for the magnetic head can be somewhat complicated. 
   Another drawback of prior art magnetic head positioner systems is that they generally include a significant number of parts due to the various screws, springs and other related components. Due to this, they tend to be difficult to assemble. An additional consequence of the number of parts is that prior art magnetic head positioner systems tend to occupy a significant amount of space in a drive housing. This aspect can be problematic in view of next generation drive housings that typically are smaller in height. 
   In view of the foregoing, a need exists in the art for a new tape positioner system that addresses the aforementioned deficiencies. 
   The foregoing examples of the related art and limitations related therewith are intended to be illustrative and not exclusive. Other limitations of the related art will become apparent to those of skill in the art upon a reading of the specification and a study of the drawings. 
   SUMMARY 
   The following embodiments and aspects thereof are described and illustrated in conjunction with systems, apparatuses and methods which are meant to be exemplary and illustrative, not limiting in scope. In various embodiments, one or more of the above-described problems have been reduced or eliminated. 
   One embodiment by way of non-limiting example provides for an apparatus, for use in a tape drive system, that facilitates adjustment of azimuth and zenith orientations of a magnetic tape head. The apparatus includes a top and bottom plate located above and below an actuator assembly that includes a magnetic head. Also included are first and second ball-ended guide rods that each have ends that mate with corresponding top and bottom plate sockets. Azimuth and zenith adjustment is provided for via at least one azimuth adjustment screw and at least one zenith adjustment screw. Various aspects of the apparatus include independent adjustment of the zenith and azimuth, where adjustments to one does not affect the other. Another aspect includes the top plate remaining in a substantially horizontal plane when either the azimuth or the zenith is adjusted. 
   In addition to the aspects and embodiments described above, further aspects and embodiments will become apparent by reference to the drawings and by study of the following descriptions. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Example embodiments are illustrated in referenced figures of the drawings. It is intended that the embodiments and figures disclosed herein are to be considered illustrative rather than limiting. 
       FIG. 1  illustrates an example LTO tape cartridge; 
       FIG. 2  illustrates an example LTO tape drive housing with the cartridge of  FIG. 1  inserted; 
       FIG. 3  is a top-down view of the cartridge inserted into the tape drive and further illustrates various internal tape drive parts; 
       FIG. 4  is an isometric view of an actuator assembly that includes a magnetic head adjustment system, in accordance with an example embodiment; 
       FIG. 5  is an isometric view of a top plate of the magnetic head adjustment system, in accordance with an example embodiment; 
       FIG. 6  is a front elevation view of the actuator assembly, in accordance with an example embodiment; 
       FIG. 7  is a side elevation view of the actuator assembly, in accordance with an example embodiment; 
       FIG. 8  is another isometric view of the actuator assembly, in accordance with an example embodiment; and 
       FIG. 9  is yet another isometric view of the actuator assembly, in accordance with an example embodiment. 
   

   DETAILED DESCRIPTION 
   The following embodiments and aspects thereof are described and illustrated in conjunction with systems, apparatuses and methods which are meant to be illustrative, not limiting in scope. 
     FIG. 1  illustrates an example LTO tape cartridge  10  and  FIG. 2  illustrates example LTO tape drive housing  200  with the cartridge  10  of  FIG. 1  inserted. Cartridge  10  is inserted into drive  200  in a direction specified by arrow  12 . Cartridge  10  also includes grip lines  14  for easy handling. Additionally, cartridge  10  includes various lock depressions  18  (also repeated on the opposite side) that mate with a male counterpart, in drive  200 , to ensure a snug fit after cartridge  10  is inserted into drive  200 . Drive  200  includes an eject button  202  and various indicators  204 . The drive  200  may be designed to fit into a half-high 5.25 inch form factor for installation into a bay of a desktop or server box. Of course, other implementations are possible. For example, the drive  200  may be a stand-alone unit, such as a desktop drive that is external from a host computing system. 
     FIG. 3  is a top-down view of the cartridge  10  inserted into the tape drive  200  which includes a magnetic head adjustment system that incorporates aspects of the claimed embodiments. A full description of the various components of drive  200  is intentionally not included in order to not unnecessarily obscure the claimed embodiments. However, some of the major components include a take-up hub  300 , various tape-threading roller guides ( 302 ,  306 ), magnetic head  304  and head flex circuits ( 310 ,  312 ). Drive  200  will also typically contain one or more processors, a memory and a controller. 
   One possible implementation of the invention is detailed in reference to  FIGS. 4-9  which show various views of an actuator assembly that includes a magnetic head adjustment system and related parts thereof. Actuator assembly  400  primarily includes a top plate  402 , a bottom plate  404 , a pair of ball-ended guide rods ( 406 ,  408 ). In between the top plate  402  and the bottom plate  404  is a base structure  410 , a retaining cap  412  and a magnetic head assembly  414  which includes the magnetic head  304 . 
   As the name suggests, the ball-ended guide rods ( 406 ,  408 ) have ends ( 406   a ,  406   b ,  408   a ,  408   b /refer to  FIG. 9  to view  406   b  and  408   b ) that are ball-shaped. Each of the ends ( 206   a ,  406   b ,  408   a ,  408   b /refer to  FIG. 9  to view  408   a  and  408   b ) mates with a corresponding socket ( 402   a ,  402   b ,  404   a ,  404   b ) on the top or bottom plate ( 406 ,  408 ). The claimed embodiments can also utilize other shapes for the ball-ended guide rods ( 406 ,  408 ) such as a slightly oval shape or a slightly elliptical shape. 
   Azimuth and zenith adjustment is provided for via adjustment screws. Specifically, zenith adjustment screw  416  (see  FIG. 8 ) provides for the zenith adjustment (in and out from the tape travel path) and azimuth adjust screws ( 418 ,  420 ) provide for the azimuth adjustment (parallel to the tape travel path). When a desired azimuth and a desired zenith are achieved, zenith clamp screws ( 421 ,  422 ) and guide rod clamp screws ( 424 ,  426 ) are tightened. Once the zenith clamps screws ( 420 ,  422 ) are tightened, additional movement of the magnetic head into and out of the tape travel path is inhibited. Tightening of the guide rod clamp screws ( 424 ,  426 ) also inhibit zenith movement and further inhibits movement of the magnetic head in the azimuth/parallel to the tape travel path. Additional screws (not shown) are also utilized at  436  and  438  to secure the ends ( 406   b ,  408   b ) to the baseplate  404 . 
   Adjustment of the azimuth and the zenith is possible since the top plate  402  is movable, to a degree, due to the ball-shaped ends ( 406   a ,  408   a ) that are mated with the corresponding sockets ( 402   a ,  402   b ) in the top plate  402 . For example, as the zenith of the magnetic head  304  is adjusted via the azimuth adjust screw ( 416 ), top plate  402  and the guide rods ( 406 ,  408 ) will also move. The magnetic head assembly  414  is slidably coupled to the guide rods ( 406 ,  408 ). As a result, the magnetic head assembly  414 , and the magnetic head  304 , will also move when the zenith adjust screw  416  is adjusted. In a similar manner, the magnetic head  304  will also move when the azimuth adjust screws ( 418 ,  420 ) are adjusted. 
   Referring to  FIG. 5  which is an isometric view of the top plate  402 , the top plate  402  is configured with flexures ( 430 ,  432 ) in a four-bar linkage pattern. This flexure configuration allows for precise azimuth adjustment of the magnetic head  304  while maintaining a high degree of stiffness in the vertical direction. The four bars of the four bar linkage pattern include the flexures ( 430 ,  432 ), a front portion  428  of the top plate  402  and a back portion  434  of the top plate  402 . The four-bar linkage pattern provides the top plate  402  with the property of being able to apply a force to one corner of the top plate  402  and opposing sides of the top plate  402  will remain parallel to each other. While opposite sides of the top plate remain parallel, adjacent sides will no longer be perpendicular to each other. 
   When screws  418  and  420  (refer to  FIG. 4 ) are tightened, the flexures ( 430 ,  432 ) will deform. However, front portion  428 , which corresponds generally to the location of ends  406   a  and  408   a , will remain parallel to its original location before the screws ( 418 ,  420 ) were tightened. Due to this, front portion  428  will not become skewed at an odd angle which would translate to the magnetic head  304  also being skewed at an odd angle. 
   Since the flexures ( 430 ,  432 ) are made from the top plate  402 , a reduction of parts is achieved as prior art magnetic head adjustment systems will typically include flexures as discrete parts. The reduction of parts is additionally advantageous in that it contributes to a space savings in a tape drive enclosure. 
   The claimed embodiments also have other advantages. One advantage is that adjusting the azimuth will not affect the zenith. Similarly, adjusting the zenith will not affect the azimuth. Adjustment of the zenith and azimuth is mutually perpendicular. Due to this, there is no interaction between the zenith and azimuth. Another advantage is that the top plate  402  will generally not move up or down when the zenith or azimuth is adjusted. Due to this feature, a tape drive design does not need to allow for extra room above the top plate  402  to allow it to move in the vertical direction during zenith and azimuth adjustments. 
   For completeness, the next sections describe various parts depicted in the figures that work in conjunction with the claimed embodiments. Referring to  FIG. 8 , stepper motor terminals  440  provide a power inlet for stepper motor  442 . Stepper motor  442  rotates threaded barrel  444  which in turn drives gear  446 . Gear  446  in cooperation with other parts that are not shown in the figures move the magnetic head assembly  414  along the guide rods ( 406 ,  408 ). The stepper motor  442 , threaded barrel  444 , gear  446 , retaining cap  412 , base structure  410 , retaining cap  412  and the guide rods ( 406 ,  408 ) form what is known as a coarse positioning structure. Cover/clamping plate  454  (refer to  FIG. 9 ) holds the stepper motor  442  in place. 
   Gear teeth  450  works in conjunction with structure  452  to rotate the entire actuator assembly  400  to equalize a tape wrap angle. Structure  452  is utilized to pivotally attach baseplate  404  to part of a tape drive and gear teeth  450  are engaged by a gear that is not shown in the figures. The tape wrap angle is the angle between the plane of the tape, as it approaches or leaves the magnetic head  304 , and tape guiding surfaces on the head. 
   Referring to  FIGS. 4 ,  6  and  8 - 9 , it can be seen that the base structure fully surrounds guide rod  408  while guide rod  406  is only partially enclosed. This is done so that the alignment of the moving section of the coarse positioner structure is controlled only by guide rod  408  as the base structure  410  wraps tightly around the guide rod  408 . The guide rod  406  provides a stop for the moving section, of the coarse positioning structure, to keep it from rotating. What is not shown is a small spring-loaded flap which rides on the guide rod  406  to keep the coarse positioning structure pressing lightly on the guide rod  406 . 
   While a number of exemplary aspects and embodiments have been discussed above, those of skill in the art will recognize certain modifications, permutations, additions and sub-combinations thereof. It is therefore intended that the following appended claims and claims hereafter introduced are interpreted to include all such modifications, permutations, additions and sub-combinations as are within their true spirit and scope.