Patent Publication Number: US-11043235-B2

Title: Assembly that enables reduction in disk to disk spacing

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This is a continuation-in-part of U.S. application Ser. No. 15/965,097 which was filed on Apr. 27, 2018, and is incorporated herein by reference in its entirety for all purposes. 
    
    
     SUMMARY 
     In one embodiment, an apparatus includes a plurality of storage media mounted on a rotatable spindle. The apparatus also includes an actuator mechanism with at least one actuator arm configured to translate among the plurality of storage media and at least two heads supported on the at least one actuator arm. Each of the at least two heads is configured to communicate with the plurality of storage media. 
     In another embodiment, an apparatus includes a plurality of storage media mounted on a spindle. The apparatus also includes at least one actuator with an actuator arm configured to translate vertically among the plurality of storage media, and at least one head supported on the actuator arm. The at least one head is configured to communicate with multiple ones of the plurality of storage media. 
     In yet another embodiment, a method is provided. The method includes providing a plurality of storage media mounted on a rotatable spindle. The method also includes providing an actuator mechanism having an actuator arm supporting a head. The actuator arm is capable of translating vertically among the plurality of storage media. Other features and benefits that characterize embodiments of the disclosure will be apparent upon reading the following detailed description and review of the associated drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIGS. 1A and 1B  illustrate an example of a data storage device in which embodiments of the present application can be used. 
         FIGS. 2A and 2B  are schematic illustrations of a data storage device according to an embodiment of the disclosure. 
         FIGS. 3A and 3B  are schematic illustrations of a data storage device according to an embodiment of the disclosure. 
         FIGS. 4A and 4B  are schematic illustrations of a data storage device according to an embodiment of the disclosure. 
         FIGS. 5A and 5B  are schematic illustrations of a data storage device according to an embodiment of the disclosure. 
         FIGS. 6A and 6B  are schematic illustrations of a data storage device according to an embodiment of the disclosure. 
         FIGS. 7A and 7B  are schematic illustrations of a data storage device according to an embodiment of the disclosure. 
         FIGS. 8A and 8B  are schematic illustrations of a data storage device according to an embodiment of the disclosure. 
         FIGS. 9A and 9B  are schematic illustrations of a data storage device according to an embodiment of the disclosure. 
         FIGS. 10A and 10B  are schematic illustrations of a data storage device according to an embodiment of the disclosure. 
         FIGS. 11A and 11B  are schematic illustrations of a data storage device according to an embodiment of the disclosure. 
         FIGS. 12A and 12B  are schematic illustrations of a data storage device according to an embodiment of the disclosure. 
         FIG. 13  is a schematic illustration of a data storage device according to an embodiment of the disclosure. 
         FIGS. 14A and 14B  are schematic illustrations of a data storage device according to an embodiment of the disclosure. 
         FIGS. 15A and 15B  are illustrations of a data storage device according to an embodiment of the disclosure. 
         FIG. 16  is an illustration of an elevator for a data storage device according to an embodiment of the disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Although the present disclosure has been described with reference to embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the scope of the disclosure. The present disclosure relates to reducing disk to disk spacing in data storage devices by using heads translatable among a plurality of disks in a disk drive. However, prior to providing additional detail regarding the different embodiments, a description of an illustrative operating environment is provided. 
       FIGS. 1A and 1B  show an illustrative operating environment in which certain data storage device embodiments disclosed herein may be incorporated. The operating environment shown in  FIGS. 1A and 1B  is for illustration purposes. Embodiments of the present disclosure are not limited to any particular operating environment such as the operating environment shown in  FIGS. 1A and 1B . Embodiments of the present disclosure are illustratively practiced within any number of different types of operating environments. 
     It should be noted that the same reference numerals are used in different figures for same or similar elements. It should also be understood that the terminology used herein is for the purpose of describing embodiments, and the terminology is not intended to be limiting. Unless indicated otherwise, ordinal numbers (e.g., first, second, third, etc.) are used to distinguish or identify different elements or steps in a group of elements or steps, and do not supply a serial or numerical limitation on the elements or steps of the embodiments thereof. For example, “first,” “second,” and “third” elements or steps need not necessarily appear in that order, and the embodiments thereof need not necessarily be limited to three elements or steps. It should also be understood that, unless indicated otherwise, any labels such as “left,” “right,” “front,” “back,” “top,” “bottom,” “forward,” “reverse,” “clockwise,” “counter clockwise,” “up,” “down,” or other similar terms such as “upper,” “lower,” “aft,” “fore,” “vertical,” “horizontal,” “proximal,” “distal,” “intermediate” and the like are used for convenience and are not intended to imply, for example, any particular fixed location, orientation, or direction. Instead, such labels are used to reflect, for example, relative location, orientation, or directions. It should also be understood that the singular forms of “a,” “an,” and “the” include plural references unless the context clearly dictates otherwise. 
       FIGS. 1A and 1B  are schematic illustrations of a data storage device (e.g., a hard disk drive or Hard Disk Drive (HDD))  100  including data storage media or disks  102 A and  102 B, heads  104 A and  104 B for reading data from and/or writing data to the data storage media, and an actuator mechanism to position the heads  104 A and  104 B.  FIG. 1A  illustrates a top view of a portion of data storage device  100  and includes lower data storage material, or storage media  102 B, e.g., second recording disk  102 B and a down or downward-facing head  104 B. The down head  104 B including transducer elements (not shown) is positioned above the data storage media  102 B to read data from and/or write data to the disk  102 B. In the embodiment shown, the disk  102 B represents a rotatable disk or other storage media that include one or more magnetic, optical or other storage layers. For read and write operations, a spindle motor  106  rotates the media  102 B (and medium or disk  102 A shown in  FIG. 1B ) as illustrated by arrow  107  and an actuator mechanism  110  positions the down head  104 B relative to data tracks on the disk  102 B. The head  104 B is coupled to an arm  122  of the actuator mechanism  110 . In the interest of simplification, arm  122  is shown as a single element to which head  104 B is coupled. However, in some embodiments, head  104 B may be coupled to actuator mechanism  110  through a suspension assembly (not shown) which may include a load beam (not shown) coupled to actuator arm  122  of the actuator mechanism  110 , for example through a swage connection. Although  FIG. 1A  illustrates a single arm  122  coupled to the actuator mechanism  110 , additional arms  122  can be coupled to the actuator mechanism  110  to support heads that read data from or write data to multiple disks of a disk stack. The actuator mechanism  110  is rotationally coupled to a frame or deck (not shown) to rotate about a pivot shaft  119 . Rotation of the actuator mechanism  110  moves the head  104 B in a cross-track direction as illustrated by arrow  130  and enables movement between an inner diameter (ID) and an outer diameter (OD) of the disk. 
       FIG. 1B  illustrates a side view of the data storage device  100 .  FIG. 1B  illustrates first or upper disk  102 A and second or lower disk  102 B coupled to spindle motor  106  and separated by a disk to disk space  111 .  FIG. 1B  further illustrates up head  104 A coupled to actuator arm  122  facing upwards towards the bottom surface of the first disk  102 A, and down head  104 B (also shown in  FIG. 1A ) facing downwards towards the top surface of the second disk  102 B. In some embodiments, heads  104 A and  104 B may be coupled to actuator arm  122  by a load beam. The heads  104 A and  104 B may be moved by actuator mechanism  110 . Up head  104 A may read data from and/or write data to the storage material on the bottom of disk  102 A, and down head  104 B may read data from and/or write data to the storage material on the top of disk  102 B. 
     As data storage increases, the volumetric density of data storage devices becomes an ever-greater concern when compared to areal density. One method of increasing volumetric density in an HDD involves reducing the disk to disk spacing between the data storage media or disks. Reducing disk to disk spacing may enable an increased number of disks to be stacked within a similar disk stack volume. 
     This disclosure generally describes apparatus and methods of decreasing the disk to disk spacing by using a fewer heads than disks in the data storage device. In such embodiments, a same head or two heads may read from and/or write to different disks at different times. A separation distance between disk or disk surfaces that are not being currently read from or written to may be relatively small (e.g.,  113  between disks  102 B and  102 C). To accommodate the same head or the two heads for a read/write operation, a spacing between two disks may be temporarily increased to, for example,  111  in  FIG. 1B . As will be described in detail further below, in such embodiments, an actuator mechanism with a single head or two heads including an up head and a down head are provided with the ability to move up and down on the Z axis to different disks in the disk stack. By utilizing a single set of heads with the ability to move up and down the Z axis to different disks in a stack, the volume of the disk stack and the cost for heads is reduced. Reducing the disk to disk spacing increases the volumetric density and therefore disk to disk space may be saved. This volumetric density has the potential to convert, for example, a current eight-disk design into an eleven-disk design within the same form factor. 
       FIGS. 2A and 2B  are schematic illustrations of a data storage device  200  that employs two heads, including an up head and a down head which may be vertically translated on the Z axis between a plurality of disks according to an embodiment of the disclosure.  FIGS. 2A and 2B  incorporate similar elements from  FIGS. 1A and 1B , such that  FIG. 2A  illustrates a top view of a portion of data storage device  200  and includes data storage medium or disk  102 F and down head  104 B. 
     In the embodiment shown, the down head  104 B and up head  104 A (seen in  FIG. 2B ) are provided on an actuator mechanism  210  to position the heads  104 A and  104 B relative to the data tracks on disk  102 F. Up head  104 A is coupled to actuator arm  122 A and down head  104 B is coupled to actuator arm  122 B. The heads  104 A and  104 B may also be coupled to the actuator mechanism  210  through a suspension assembly which may include a load beam (not shown) coupled to actuator arm  122 A,  122 B of the actuator mechanism  210 . Actuator arms  122 A and  122 B are mounted on pivot shaft  219 , respectively, to provide rotation in a cross-track direction as illustrated by arrow  130 . Thus, for read and write operations, a spindle motor  106  rotates the disk  102 F (as well as disks  102 A- 102 I seen in  FIG. 1B ) as illustrated by arrow  107  and actuator mechanism  210  positions the heads  104 A and  104 B relative to data tracks on the disk  102 F in a cross-track motion as illustrated by arrow  130 . 
       FIG. 2B  illustrates a side view of the data storage device  200 .  FIG. 2B  illustrates a nine-disk stack with a first or topmost disk  102 A, to a ninth or bottommost disk  102 I coupled to spindle motor  106  and separated by disk to disk space  211 . As can be seen, disk to disk space  211  provides disk separation allowing for a single head  104 A,  104 B between disks  102 . Thus, disk to disk space  211  is smaller than disk to disk space  111  of  FIG. 1B , which reduces disk to disk spacing on the Z axis in a disk stack overall. Although nine disks are illustrated in the disk stack, this is exemplary only, and a plurality of disks may be used in a data storage device according to the disclosure. 
       FIG. 2B  further illustrates up head  104 A on actuator arm  122 A facing upwards towards the bottom surface of disk  102 F and down head  104 B on actuator arm  122 B facing downwards towards the top surface of disk  102 F. The heads  104 A and  104 B may be moved by actuator mechanism  210 . Actuator arms  122 A and  122 B of heads  104 A and  104 B are coupled to pivot shaft  219  and may be translatable vertically along the Z axis as illustrated by arrow  217 . Actuator mechanism  210 , therefore, enables heads  104 A and  104 B to translate vertically in the Z axis, e.g., along arrow  217 , to any disk  102  in a disk stack as well as to rotate in cross track motion along arrow  130 . 
     Actuator mechanism  210  enables the arms  122 A and  122 B to rotate and translate to allow head  104 A and  104 B to communicate with the data storage material or storage media on any disk of a disk stack. For example, up head  104 A may read data from and/or write data to the storage material on the bottom of disk  102 A, and down head  104 B may read data from and/or write data to the storage material on the top of disk  102 A. This action may be carried out by first rotating heads  104 A,  104 B in a cross-track direction away from their current position by translating heads  104 A,  104 B until they are off their current disk, e.g.,  102 F. Then, actuator mechanism  210  may translate heads  104 A and  104 B vertically on the Z axis (as indicated by arrow  217 ) until they have reached the selected disk, e.g.,  102 A. Actuator mechanism  210  may then rotate heads  104 A and  104 B in a cross-track direction until heads  104 A and  104 B are in communication with the data storage material of disk  102 A. Although  FIGS. 2A and 2B  illustrate a nine-disk stack, these illustrations are exemplary only, and a data storage device may be provided with a plurality of data storage media with reduced disk to disk spacing according to embodiments of the present disclosure. 
       FIGS. 3A and 3B  are a schematic illustration of a data storage device  300  that employs a single set of up and down heads according to an embodiment of the disclosure.  FIGS. 3A and 3B  incorporate similar elements from  FIGS. 2A and 2B , such that  FIG. 3A  illustrates a top view of a portion of a data storage device  300  and includes a data storage medium or disk  102  and an up head  104 A. 
       FIGS. 3A and 3B  illustrate an embodiment of the present disclosure wherein the disks  102  coupled to a spindle motor  306  may be translatable vertically along the Z axis as illustrated by arrow  217 . Similarly, to  FIGS. 1A and 1B , in  FIG. 3B  up head  104 A and down head  104 B are coupled to actuator arm  122  such that  104 A faces upwards towards the bottom surface of a disk  102 I, and down head  104 B faces downwards towards the top surface of a disk  102 J. Similar to  FIGS. 2A and 2B , actuator arm  122  is coupled to pivot shaft  219  and may be translatable vertically along the Z axis as illustrated by arrow  217  or horizontally in a direction along the X axis and/or Y axis, as illustrated by arrows  215  and  216  respectively. Actuator mechanism  210 , therefore, enables heads  104 A and  104 B to translate vertically along arrow  217  in the Z axis to any disk  102  in a disk stack as well as to rotate in cross track motion along arrow  130 . Translating along the X axis and Y axis enables heads  104 A and  104 B to have an adjustable position on a disk  102  in the disk stack. 
       FIG. 3B  illustrates an embodiment where data storage device  300  may further increase volumetric capacity by allowing disks  102  to translate vertically and decrease their relative disk spacing to a disk to disk spacing  311 . Spindle motor  306  enables disks  102  to translate vertically along arrow  217  in the Z axis, such that disks  102  may increase or decrease their relative disk to disk spacing. Disk to disk spacing  311  may be less than disk to disk spacing  211  of  FIG. 2B . Therefore, by employing a single set of up and down heads, heads  104 A,  104 B may occupy a disk to disk space  111 , such as between disks  102 I and  102 J, and the remaining disks  102  of the disk stack may occupy a reduced disk to disk spacing  311 . 
     Actuator mechanism  210  in cooperation with spindle motor  306  enables the heads  104 A and  104 B to communicate with the data storage material on any disk of a disk stack, while keeping a reduced disk to disk spacing  311 . For example, if heads  104 A and  104 B are to read data from and/or write data to data storage material of a disk they are not currently aligned with, e.g., disk  102 I or  102 J, actuator mechanism  210  may rotate arm  122  in a cross-track motion by arrow  130  until heads  104 A and  104 B are off the disk. Disks  102  may then translate vertically on the Z axis (as indicated by arrow  217 ) on spindle  306  until disks  102  have opened a disk to disk spacing  111  to allow heads  104 A and  104 B to communicate with the appropriate data storage media. Actuator mechanism  210  may translate heads  104 A,  104 B vertically on the Z axis (as indicated by arrow  217 ) until they have reached the selected disk, and then rotate heads  104 A and  104 B in a cross-track direction until heads  104 A and  104 B are in communication with the appropriate data storage material. 
     Although  FIGS. 3A and 3B  illustrate a fourteen-disk stack, these illustrations are exemplary only, and a data storage device may be provided with a plurality of data storage media with the ability to provide reduced disk to disk spacing according to embodiments of the disclosure. Further, while  FIGS. 3A and 3B  illustrate a data storage device  300  with arm  122  coupled to heads  104 A,  104 B, a plurality of arms  122  (e.g.,  122 A or  122 B of  FIG. 2B ) may be used in conjunction with spindle motor  306  for moving disks  102  in a vertical direction. 
     Data storage device  300  includes heads  104 A and  104 B placed between two disks, e.g., disks  102 I and  102 J, which will both rotate about spindle motor  306  in direction of arrow  107  when in use. However, the remaining disks  102  not in communication with heads  104 A and  104 B may remain stationary if so desired. In an example where disks  102  not in communication remain stationary, power consumption of device  300  may be reduced. 
       FIGS. 4A and 4B  illustrate an embodiment of the present disclosure similar to  FIGS. 3A and 3B , wherein the disks  102  coupled to spindle motor  306  may be translatable vertically along the Z axis as illustrated by arrow  217 . Similar to  FIG. 2B , up head  104 A is coupled on actuator arm  122 A facing upwards towards the bottom surface of an engaged disk, e.g.,  102 J, and down head  104 B is coupled to actuator arm  122 B facing downwards towards the top surface of the engaged disk, e.g., disk  102 J. The heads  104 A and  104 B may be moved by actuator mechanism  210 . Thus, disks  102  may translate vertically along spindle  306  to enable heads  104 A,  104 B to selectively engage any disk  102  to read data from and/or write data to the storage material on the bottom of disk. In one example, only one disk, e.g.,  102 J, is in motion and engaged by the heads  104 A and  104 B to allow communication with the storage material on the top and bottom of the disk  102 . Data storage device  400  provides an example of an embodiment of the present disclosure when the disks  102  not engaged by the heads  104 A and  104 B may remain stationary to further reduce power consumption. 
       FIGS. 5A and 5B  illustrate an embodiment of the present disclosure similar to  FIGS. 2A and 2B  and includes an alignment and positioning system of actuator mechanism  510 .  FIGS. 5A and 5B  illustrates up head  104 A on actuator arm  122 A facing upwards towards the bottom surface of disk  102 F and down head  104 B on actuator arm  122 B facing downwards towards the top surface of disk  102 F. The heads  104 A and  104 B may be moved by actuator mechanism  510 . Actuator arms  122 A and  122 B of heads  104 A and  104 B are coupled to an alignment system  520 , e.g., pivot shaft  519 , and may be translatable vertically along the Z axis as illustrated by arrow  217 . 
     An apparatus for improving alignment and positioning of the heads may include alignment combs and a ramp load mechanism. Arms  122 A and  122 B may be coupled to alignment system  520  to position heads  104 A,  104 B with a disk, e.g.,  102 F of the disk stack. Alignment system  520  may include a first alignment comb  519 A with protrusions and a second alignment comb  519 B with corresponding receivers to translate the heads  104 A and  104 B vertically along the Z axis as illustrated by arrow  217  and align with the disks  102 . Actuator mechanism  510 , therefore, enables heads  104 A and  104 B to translate vertically along arrow  217  in the Z axis to any disk  102  in a disk stack as well as to rotate in cross track motion along arrow  130 . A ramp load mechanism  525  may be included adjacent to the disk stack to aid in loading or unloading the heads  104 A,  104 B from the disks  102 . As can be seen, disk to disk space  211  provides disk separation allowing for a single head between disks  102 . Although  FIGS. 5A and 5B  illustrate an example of a data storage device wherein the disks  102  do not move in a vertical direction on the Z axis, data storage device  500  may include vertical disk movement (e.g., spindle motor  306  of  FIG. 3 or 4 ) with features such as actuator mechanism  510 , alignment system  520 , or ramp load mechanism  525 . 
     Further, the embodiments shown illustrate devices using a single pair of up and down heads, but these illustrations are exemplary only, and a data storage device may use a plurality of up and down heads in a variety of combinations with the features described herein. For example, multiple heads  104  may be set up in a similar configuration to access different disks  102  simultaneously. Possibilities include using a plurality of actuator mechanisms, e.g., actuator mechanism  210 , or a plurality of actuator arms, e.g., actuator arm  122 , to support a plurality of heads  104 . Multiple heads  104  may be included on the same actuators to use the same cross-stroke, e.g., along cross disk arrow  130 , and vertical direction, e.g., translated vertically along the Z axis as illustrated by arrow  217 . Multiple heads may also use different actuators to act independently and engage different disks, or different storage material on the same disk, simultaneously. 
     Actuator mechanisms may use a variety of formats to translate heads  104 A and  104 B vertically along the Z axis as illustrated by arrow  217 . These vertical actuator formats may include, but are not limited to, magnetic lift systems, pully systems, or worm gear systems. Actuator mechanisms may also include a clutch mechanism to provide further alignment precision and to maintain the position of the heads  104 . Alternatively, actuators may include an intrinsic clutch to provide alignment and stability for the heads. 
       FIGS. 6A and 6B  illustrate an embodiment of the present disclosure using magnetic film coated foil to increase volumetric density. Similar to  FIGS. 3A and 3B , data storage device includes actuator arm  122  coupled to pivot shaft  219  such that actuator mechanism  210  enables heads  104 A and  104 B to translate vertically along arrow  217  in the Z axis as well as to rotate in cross track motion along arrow  130 .  FIGS. 6A and 6B  illustrate a data storage device  600  in which the data storage media are a plurality of foils  602  coated with magnetic film. A spindle motor  606  rotates the media  602  as illustrated by arrow  107  and actuator mechanism  210  positions the heads  104 A and  104 B relative to data tracks on the storage media  602 . Heads  104 A and  104 B may communicate with foils  602  with magnetic film for reading data from and/or writing data to the data storage media. Foils  602  with magnetic film may provide a much thinner data storage media, as compared to disks, such as disks  102 . Spindle motor  606  enables storage media  602  to translate vertically along arrow  217  in the Z axis, such that storage media  602  may increase or decrease their relative spacing, similar to disk to disk spacing  111 . 
     As seen in  FIG. 6B , heads  104 A and  104 B may be positioned between foils  602  to communicate with the magnetic media of a bottom portion of a foil and a top portion of a foil respectively and have a spacing  611  similar in size to disk to disk spacing  111  to accommodate the heads  104 A,  104 B in the vertical or Z axis. As the foils  602  are rotated by spindle motor  606 , the foils  602  remain rigid, and the foils  602  not engaged by heads  104  may become closely spaced due to centrifugal force. Thus, because foils  602  with magnetic film are thinner than disks  102 , and may be more closely spaced than disks  102 , they may greatly increase the volumetric density of a data storage device. 
     A variety of methods may be used to translate storage media up and down in a vertical Z axis, such as by arrow  217 .  FIGS. 7A and 7B  illustrate an embodiment of data storage device  700  using a head-based disk movement system.  FIGS. 7A  and B illustrate disks  102  coupled to spindle motor  306  and an actuator mechanism  710  to position the heads  104 A,  104 B relative to the data tracks on the disks  102 . Up head  104 A is coupled to actuator arm  122 A and down head  104 B is coupled to actuator arm  122 B. Clamp system  720  is provided to keep disks  102  in place when not in translation vertically along the Z axis. As seen in  FIG. 7B , a head-based disk translation system is used to move disks  102  to their respective positions, such that a head  104  may be positioned by actuator mechanism  710  to an ID of disk  102  and then arm  122  may be moved or translated upwards or downwards according to arrow  217  to push the disks  102  up or down along spindle  306 . For example, actuator arm  122 B may be inserted between disk  102 D and disk  102 E and then translated upwards along pivot shaft  219  to maneuver disk  102 D to its respective position on spindle  306 . Once disks  102  are in place, clamp system  720  maintains the disks  102  in their respective position. 
       FIGS. 8A and 8B  illustrate an embodiment of data storage device  800  using a spindle shaft-based disk movement system. Similar to  FIGS. 7A and 7B , disks  102  are coupled to spindle motor  306  and an actuator mechanism  710  to position the heads  104 A and  104 B relative to the data tracks on the disks  102 . Up head  104 A is coupled to actuator arm  122 A and down head  104 B is coupled to actuator arm  122 B. Clamp system  720  is provided to keep disks  102  in place when not in translation vertically along the Z axis. Spindle motor  306  is configured with an inner shaft  820  to move disks  102  into position. For example, to provide head  104  access with storage media on disks  102 D and  102 E, inner shaft  820  on spindle motor  306  may position disk  102 D upwards and disk  102 E downwards along arrow  817 , and clamp system  720  may then maintain the disks  102  in their respective positions. Actuator mechanism  710  may then translate arms  122 A and  122 B vertically along arrow  217  in the Z axis as well as to rotate arms  122 A and  122 B in cross track motion along arrow  130  to position heads  104 A and  104 B for reading data from and/or writing data to the data storage media. 
       FIGS. 9A and 9B  illustrate an embodiment of a data storage device  900 , shown to be similar to  FIGS. 5A and 5B , and includes an ID feature  915  on an ID  920  of disk  102 . ID feature  915  may, as a non-limiting example, be ridges, a sinusoidal wave, a square wave, a particular series of shapes, coordinates or a combination thereof. Further, ID feature  915  may be etched or printed on ID  920  or may be cut into ID  920  continuously around ID  920  or may cover a selected portion of ID  920 . ID feature  915  may be symmetrical or asymmetrical about the X axis of disk  102 . Each disk  102  may have its own unique or individualized ID feature  915  different from the other disks in disk stack  922 . By way of a non-limiting example, ID feature  915  of disk  102 I may be different from ID feature  915  of disk  102 J. 
     Spindle motor  306  may be arranged inside a perimeter of ID  920  and configured with an access mechanism  925 . Alternatively, access mechanism  925  may be arranged separate but adjacent to spindle motor  306 . Access mechanism  925  may be keyed with a shape or feature that matches or coordinates with feature  915 . This may allow access to and isolate a specified or identified single disk in order to separate it from at least one neighboring disk. Access mechanism  925  may be matched or keyed to the identified disk and positioned at the identified disk in order to clip or grab the identified disk  102 . The shape of access mechanism  925  may be changed to match a different ID feature  915  by using an external program which is configured to send a signal to the access mechanism  925  with the assigned shape that corresponds to the identified disk. By way of a non-limiting example, disk  102 J may be marked as the identified disk. Disk  102 J may be separated from neighboring disk  102 I and/or disk  102 K by moving disk  102 J either up or down. To move disk  102 J, access mechanism  925  is matched or keyed to feature  915  on disk  102 J. Access mechanism  925  latches or grabs onto disk  102 J and moves disk  102 J to a selected or different vertical location along the spindle motor  306 , thereby separating disk  102 J from disk  102 I and/or  102 K. Because access mechanism  925  is keyed to feature  915  on disk  102 J, disk  102 J, as the identified individual disk, may be selectively isolated from the neighboring disks. 
     Further, more than one disk  102  may be moved by access mechanism  925 . A plurality of access mechanisms  925  may move a corresponding number of disks  102 . Alternatively, a single access mechanism may move a plurality of disks  102  separately. 
     In addition to, or instead of, access mechanism  925 , the spindle motor  306  includes at least one air diverter  940  used to aid in separating disks  102  of disk stack  922 . Air diverter  940  may be positioned at ID  920  on the spindle and/or an OD  930  of disk stack  922 . Air diverter  940  provides a puff or flow of air separating one disk from another, thereby providing space for access mechanism  925  to latch onto disk  102  and move disk  102  to the desired location. In an alternative embodiment, air diverter  940  provides space for arm  122  to be inserted between disks without the use of access mechanism  925 . 
       FIGS. 10A and 10B  illustrates an embodiment of a storage device  1000  which is an alternative of storage device  900 , as shown in  FIGS. 9A and 9B . Instead of, or in addition to, ID  920  having feature  915 , OD  1020  of disk  102  has an OD feature  1015 . OD feature  1015 , as a non-limiting example, comprises the same shape or structure as that listed in conjunction with ID feature  915 . As illustrated in  FIG. 10A , disk  102 A has a different OD feature  1015  than disk  102 B. By way of example, disk  102 A has a smooth OD feature  1015  and disk  102 B has a sinusoidal OD feature  1015  indicated by the dashed line in  FIG. 10A . Each of the subsequent disks, likewise, have a unique or different OD feature  1015 . OD feature  1015  may be continuous around OD  1020  or may only cover a portion of OD  1020 . Further, OD feature  1015  may be symmetrical or asymmetrical about the Z axis of disk  102 . The OD feature  1015  provides a unique signature for an access mechanism  1025  to latch onto the disk. 
     In an embodiment, access mechanism  1025  is arranged at the OD  1020  of disk  102  as part of actuator mechanism  210 . Alternatively, access mechanism  1025  is arranged as a separate structure adjacent to OD  1020 . Access mechanism  1025  is keyed with a shape or feature that matches or coordinates with feature  1015 . This may allow access mechanism  1025  to access and isolate specified single disk in order to separate it from at least one neighboring disk. As with the embodiment discussed in relation to  FIGS. 9A and 9B , access mechanism  1025  is positioned at the matching disk in order to clip or grab the specified disk  102 , thereby separating the specified disk from at least one of the neighboring disks. 
       FIGS. 11A and 11B  illustrate an embodiment of storage device  1100  comprising, as a non-limiting example, actuator mechanisms  1110 A,  1110 B and  1110 C, although storage device  1100  may include more or less actuator mechanisms. Each of actuator mechanisms  1110 A,  1110 B and  1110 C may include at least one actuator arm  122  coupled to at least one head  104 A and  104 B. By way of a non-limiting example, actuator mechanisms  1110 A and  1110 B may be configured similar to that illustrated in  FIG. 4B , each having a first actuator arm  1122 A and a second actuator arm  1122 B. Actuator mechanism  1110 C is shown to have a different configuration to indicate that the arm arrangement need not be the same. As illustrated, actuator mechanism  1110 C is configured similar to that illustrated in  FIG. 3B  having a single arm  122  with two heads  104 A and  104 B. While  FIG. 11B  is illustrated to show actuator mechanisms configured as in  FIG. 3B  and  FIG. 4B , any mentioned combination of embodiments may be used. Each actuator mechanisms  1110 A,  1110 B and  1110 C may operate in cooperation or independent from that of another actuator mechanism and may be positioned such that the heads carried by actuator mechanisms  1110 A and  1110 B communicate with the same disk  102 J in disk stack  1102  or, in an alternative arrangement, at least one head carried by actuator mechanism  1110 C may be in communication with different disks, for example disk  102 D and disk  102 E. By way of example, at least one head carried by actuator mechanism  1110 A may be configured to read disk  102 J, at least one head carried by actuator mechanism  1110 B may be configured to write to disk  102  and at least one head carried by actuator mechanism  1110 C may be configured to both read and write to disk  102 C. 
       FIGS. 12A and 12B  illustrate an embodiment of a storage device  1200  having a plurality of disk stacks  1222 A,  1222 B,  1222 C and  1222 D.  FIG. 12A  shows a first disk stack  1222 A, a second disk stack  1222 B, a third disk stack  1222 C and a fourth disk stack  1222 D. Although four disk stacks are shown, there may be more or less disk stacks. Each disk stack  1222  may have an arrangement similar to any of the other discussed embodiments. An actuator mechanism  1210  is configured with at least one actuator arm  122 , each actuator arm  122  having at least one head  104 . The at least one actuator arm  122  is configured to rotate about the Z axis such that the at least one head  104  rotates  1230  from one disk stack to a different disk stack. The actuator arms  122  are configured to be at least 360 degrees rotatable. Further, as discussed with the embodiment shown in  FIG. 3 , actuator mechanism  1210  is configured to translate in the x-direction  215  along the x-axis, y-direction  216  along the y-axis and z-direction  217  along the z-axis in order to provide precise head  104  placement on disk  102 . By way of non-limiting example, the at least one head  104  may rotate  1230  from first disk stack  1222 A to second disk stack  1222 B. Actuator arm  122  may rotate from disk stack  1222 A to disk stack  1222 B, along with translating along the Z axis in the z-direction  217  of the actuator mechanism  1210  to a specified disk  102  in disk stack  1222 B. As shown in  FIG. 12B , the at least one head  104  of arm  122  is arranged between two disks of disk stack  1222 A. Arm  122  is configured to rotate  1230  to disk stack  1222 B where the disks in the disk stack  1222 B are translated up or down until there is a gap between the desired disks. The arm  122  is translated along the z-direction  217  along the z-axis until it reaches the desired height. The arm  122  is then rotated  1230  to a different disk stack i.e., disk stack  1222 B-D. The disks  102  in disk stack  1222 A either remain in the position they were left in to conserve energy, or the disks are translated such that there is no gap between them in order to conserve space. 
       FIG. 13  illustrates an embodiment of a storage device  1300  comprising a plurality of disk stacks  1322  and a plurality of actuator mechanisms  1310 . Storage device  1300  includes disk stacks  1322 A- 1322 H with actuator mechanism  1310 A- 1310 C. There may be more or less disk stacks  1322  and there may be more or less actuator mechanisms. Further, although a 4×2 arrangement of disk stacks is illustrated, other dimensions may also be used. Actuator arm  122  of actuator mechanism  1310 A may rotate  1340 , either clock-wise or counterclockwise, about the Z axis to disk stack  1322 A,  1322 B,  1322 C or  1322 D. Likewise, actuator arm  122  of actuator mechanism  1310 B may rotate  1340  about the Z axis to disk stack  1322 C,  1322 D,  1322 E or  1322 F. Actuator arm  122  of actuator mechanism  1310 C may rotate  1340  about the Z axis to disk stack  1322 E,  1322 F,  1322 G or  1322 H. Further, each of the actuator mechanisms  1310 A- 1310 C may be configured to translate in the x-direction  215  and/or the y-direction  216 . The actuator mechanism may be configured similar to any of the described embodiments. Further, as with the actuator mechanism described in the embodiment shown in  FIG. 12B , each actuator arm  122  may translate along the Z axis in the z-direction  217  of the actuator mechanism  1312  to a specified disk  102  in disk stack  1322 . 
       FIGS. 14A and 14B  illustrates another embodiment of a storage device  1400 . The storage device  1400  includes at least one arm stack  1415 A,  1415 B, each arm stack  1415 A-B comprising a plurality of arms  1420 A,  1420 B,  1420 C. Each of the plurality of arms  1420 A-C includes a head  1425 . The arm stack may comprise additional or fewer arms than illustrated in  FIGS. 14A and 14B . Further, although two arm stacks  1415 A-B are illustrated in  FIGS. 14A and 14B , there may be more arm stacks or a single arm stack. Arm stacks  1415 A-B provide a jointless connection between arms  1420 A-C such that a movement performed by one arm is performed by all of the arms. Thus, arms  1420 A-C rotate in unison and the arm stack  1415  are configured to move along the z-axis, positioning arms  1420 A-C between a different set of disks. This embodiment allows the storage device  1400  to have a reduced number of heads  1425  and pre-amp channels than the case of an arm arrangement stationary in the sense that it does not move along the z-axis. 
     In an embodiment, the arms are arranged such that every other disk is arranged with a head  1425 , the head  1425  may be arranged to read/write from the top of disk and/or the bottom of the disk. Thus, a disk may be arranged with one or two heads. In another embodiment, the number of arms is reduced such that there are only two heads, the uppermost head being arranged as a down head and the bottommost head being arranged as an up head, such that the uppermost head is arranged over the top surface of a disk  102  and the bottommost head is arranged over the bottom side of the same disk. This embodiment is advantageous as it allows the disks to remain in the same position along the z-axis, while still reducing the number of arms in the disk storage drive. 
     In addition to the arm stacks  1415 A-B, an embodiment of storage device  1400  further includes at least one ramp  1430 A-B, where the number of ramps corresponds to the number of heads in the storage device  1400 , such that each head has a resting place on the at least one ramp. An elevator mechanism enables arm stack  1415 A-B and ramp  1430 A-B to move, in some embodiments the arm stack  1415 A-B and the corresponding ramp  1430  A-B move in unison. A particular embodiment of the elevator mechanism is described in further detail below in connection with  FIG. 16 . When the arm stack  1415 A-B is to be repositioned to a different location from the current location in order to access a different disk, the elevator mechanism moves the corresponding ramp  1430 A-B. In an embodiment, the ramp  1430  and the arm stack  1415  are connected to the same actuator or elevator mechanism enabling the arm stack  1415 A-B and the ramp  1430 A-B to move together. 
     In an alternative embodiment of a storage device  1500  illustrated in  FIGS. 15A and 15B , a two-stop elevator system comprises at least four heads  1525  and four preamp channels. The heads  1525  are moved in unison such that they initially access two disks (e.g., disk  102   b  and disk  102   d  shown in  FIG. 15A ), and when they move, the heads access disks  102   a  and  102   c  shown in  FIG. 15B . 
     In an alternative arrangement, the arms may be arranged such that the heads  1525  access the bottom or the top half of, for example, a four-disk stack. By way of example, the arms in arm stack  1515  are arranged to access disks  102   d  and  102   c  and are then moved in unison to access disks  102   b  and  102   a . The arm stack  1515  is also movable in the opposite direction back to disk  102   c  and  102   d . As discussed above, the embodiment illustrated in  FIGS. 15A and 15B  may also include a moveable ramp  1430  which follows the movement of the heads  1525  such that the movable ramp  1430  moves in unison with the heads  1525 . 
     Alternatively, storage device  1500  may be configured with a multi-stop elevator. As an alternative to the embodiment shown in  FIGS. 15A and 15B , storage device  1500  may include two heads  1525  of the four heads illustrated with two preamp channels, where the heads  1525  access a single disk. The heads may be moved from disk to disk. By way of example, the heads may be moved from disk  102   d  to disk  102   a , or from disk  102   d  to disk  102   c . The reduction of the number of heads and preamp channels allows for a reduction in cost. 
     In the different embodiments described above, moveable pieces within storage devices may be enclosed in membranes or bellows in order to prevent contaminates or particles from reaching the disks/heads. In the particular embodiment shown in  FIGS. 15A and 15B , an example of bellows  1530  is illustrated. In this embodiment, an E-block  1545  moves along and about a stationary shaft  1519 . E-block  1545  includes arm stack  1515 . Linear or rotary movement along or about shaft  1519  may create friction. To prevent contaminates or particles, which may be emitted from the movement of E-block  1545  along shaft  1519 , from entering the disk/head space, bellows  1530  are arranged around shaft  1519  at each end of E-block  1545  and in connection with E-block  1545 . Bellows  1530  are flexible and able to expand and contract as arm stack  1515  and E-block  1545  move up and down along shaft  1519 . Thus, as E-block  1545  moves, particles are contained between E-block  1545  and shaft  1519  by bellows  1530 . 
       FIG. 16  illustrates an embodiment of an elevator  1600  for the moveable ramp and the arms, allowing them to move in unison. Elevator  1600  comprises an upper portion  1601  and a lower portion  1602 . Each portion having a flexible first end  1630  and a flexible second end  1632 . The arm stack  1415  and moveable ramp  1430  are positioned between the upper portion  1601  and the lower portion  1602  and are connected together via a base  1620 , thus when the arm stack  1415  moves, the moveable ramp moves also. The elevator may be driven up and down by a coil and a magnet (not shown) with hard stops at both ends. Thus, when driven up, the arm stack  1415  and the moveable ramp  1430  are stopped by an upper limit of the system. In the embodiment illustrated in  FIG. 16 , the upper limit comprises a stopper  1650  arranged with the moveable ramp  1430 . The flexible first end  1630  of the upper portion  1601  reaches the stopper  1650  of the moveable ramp and halts the upward movement. In the downward movement, the movement may be stopped by the base  1420  reaching the flexible first end  1630  of the lower portion  1602  which halts the progression of the downward movement. This arrangement may be advantageously pre-assembled before being placed into a form factor for a disc drive and further allows for a gain in areal density and/or an improved throughput performance. Further, this arrangement reduces the number of moving parts in a disk drive. 
     Although the various embodiments and figures illustrate storage devices with various numbers of storage media in a stack, these illustrations are exemplary only, and a data storage device may be provided with a plurality of data storage media with the ability to provide reduced disk to disk spacing according to embodiments of the disclosure. 
     The illustrations of the embodiments described herein are intended to provide a general understanding of the structure of the various embodiments. The illustrations are not intended to serve as a complete description of all of the elements and features of apparatus and systems that utilize the structures or methods described herein. Many other embodiments may be apparent to those of skill in the art upon reviewing the disclosure. Other embodiments may be utilized and derived from the disclosure, such that structural and logical substitutions and changes may be made without departing from the scope of the disclosure. Additionally, the illustrations are merely representational and therefore are not drawn to scale. Certain proportions within the illustrations may be exaggerated, while other proportions may be reduced. Accordingly, the disclosure and the figures are to be regarded as illustrative rather than restrictive. 
     Although specific embodiments have been illustrated and described herein, it should be appreciated that any subsequent arrangement designed to achieve the same or similar purpose may be substituted for the specific embodiments shown. This disclosure is intended to cover any and all subsequent adaptations or variations of various embodiments. Combinations of the above embodiments, and other embodiments not specifically described herein, will be apparent to those of skill in the art upon reviewing the description. 
     In addition, in the foregoing Detailed Description, various features may be grouped together or described in a single embodiment for the purpose of streamlining the disclosure. This disclosure is not to be interpreted as reflecting an intention that the claimed embodiments employ more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive subject matter may be directed to less than all of the features of any of the disclosed embodiments. 
     The above-disclosed subject matter is to be considered illustrative, and not restrictive, and the appended claims are intended to cover all such modifications, enhancements, and other embodiments, which fall within the true spirit and scope of the present disclosure. Thus, to the maximum extent allowed by law, the scope of the present disclosure is to be determined by the broadest permissible interpretation of the following claims and their equivalents and shall not be restricted or limited by the foregoing detailed description.