Abstract:
Apparatuses are configured to addresses tape dimensional stability (TDS) via small rotations about the quasi-static tilt angle and read and/or write data in non-legacy formats. Products such as tape media products are also presented.

Description:
BACKGROUND 
       [0001]    The present invention relates to data storage systems, and more particularly, this invention relates to a magnetic head and system implementing the same, where the head has offset arrays. 
         [0002]    In magnetic storage systems, data is read from and written onto magnetic recording media utilizing magnetic transducers. Data is written on the magnetic recording media by moving a magnetic recording transducer to a position over the media where the data is to be stored. The magnetic recording transducer then generates a magnetic field, which encodes the data into the magnetic media. Data is read from the media by similarly positioning the magnetic read transducer and then sensing the magnetic field of the magnetic media. Read and write operations may be independently synchronized with the movement of the media to ensure that the data can be read from and written to the desired location on the media. 
         [0003]    An important and continuing goal in the data storage industry is that of increasing the density of data stored on a medium. For tape storage systems, that goal has led to increasing the track and linear bit density on recording tape, and decreasing the thickness of the magnetic tape medium. However, the development of small footprint, higher performance tape drive systems has created various problems in the design of a tape head assembly for use in such systems. 
         [0004]    In a tape drive system, magnetic tape is moved over the surface of the tape head at high speed. Usually the tape head is designed to minimize the spacing between the head and the tape. The spacing between the magnetic head and the magnetic tape is crucial so that the recording gaps of the transducers, which are the source of the magnetic recording flux, are in near contact with the tape to effect writing sharp transitions, and so that the read element is in near contact with the tape to provide effective coupling of the magnetic field from the tape to the read element. 
         [0005]    The quantity of data stored on a magnetic tape may be increased by increasing the number of data tracks across the tape. More tracks are made possible by reducing feature sizes of the readers and writers, such as by using thin-film fabrication techniques and magnetoresistive (MR) sensors. However, for various reasons, the feature sizes of readers and writers cannot be arbitrarily reduced, and so factors such as lateral tape motion transients and tape lateral expansion and contraction (e.g., perpendicular to the direction of tape travel) must be balanced with reader/writer sizes that provide acceptable written tracks and readback signals. One issue limiting areal density is misregistration caused by tape lateral expansion and contraction. Tape width can vary by up to about 0.1% due to expansion and contraction caused by changes in humidity, tape tension, temperature, aging etc. This is often referred to as tape dimensional stability (TDS), or more properly, tape dimensional instability (TDI). 
         [0006]    If the tape is written in one environment and then read back in another, the TDI may prevent the spacing of the tracks on the tape from precisely matching the spacing of the reading elements during readback. In current products, the change in track spacing due to TDI is small compared to the size of the written tracks and is part of the tracking budget that is considered when designing a product. As the tape capacity increases over time, tracks are becoming smaller and TDI is becoming an increasingly larger portion of the tracking budget and this is a limiting factor for growing areal density. 
       BRIEF SUMMARY 
       [0007]    An apparatus according to one embodiment includes at least two modules, each of the modules having an array of transducers of a particular type selected from a group consisting of data readers and data writers. Each of the modules also has at least one servo reader. A centerline span of outermost transducers of each of the modules is at least 28% of a usable width of a tape for which the modules are designed. An axis of each array is defined between opposite ends thereof, the axes of the arrays being nominally oriented about parallel to each other. The transducers of each array are spatially arranged along the axis of the associated array such that adjacent pairs of the transducers along the axis have about a uniform separation. The array of a first of the modules is offset from the array of a second of the modules in a first direction parallel to the axis of the array of the second module such that the transducers of the first module are about aligned with the transducers of the second module in an intended direction of tape travel thereacross when the axes are oriented at an angle between greater than 0.2° relative to a line oriented perpendicular to the intended direction of tape travel thereacross. The apparatus also includes a mechanism for orienting the modules to control a transducer pitch presented to a tape. 
         [0008]    A product according to one embodiment includes a magnetic recording tape having N servo tracks written thereon in a longitudinal direction. The magnetic recording tape in one approach has M=N or M=N+1 recordable regions thereon. In an alternate approach, the magnetic recording tape has M=N−1 recordable regions thereon when N is an integer less than 5. 
         [0009]    An apparatus according to another embodiment includes at least two modules, each of the modules having an array of at least eight transducers selected from a group consisting of data readers and data writers. Each of the modules also has at least one servo reader. A centerline span of outermost transducers of each array is smaller than 10% of a width of a tape for which the modules are designed. The axis of each array is defined between opposite ends thereof, and the axes of the arrays are nominally oriented about parallel to each other. The transducers of each array are spatially arranged along the axis of the associated array such that adjacent pairs of the transducers along the axis have about a uniform separation. The array of a first of the modules is offset from the array of a second of the modules in a first direction parallel to the axis of the array of the second module such that the transducers of the first module are about aligned with the transducers of the second module in an intended direction of tape travel thereacross when the axes are oriented at an angle greater than 0.2° relative to a line oriented perpendicular to the intended direction of tape travel thereacross. The apparatus also includes a mechanism for orienting the modules to control a transducer pitch presented to a tape. 
         [0010]    Any of these embodiments may be implemented in a magnetic data storage system such as a tape drive system, which may include a magnetic head, a drive mechanism for passing a magnetic medium (e.g., recording tape) over the magnetic head, and a controller electrically coupled to the magnetic head. 
         [0011]    Other aspects and embodiments of the present invention will become apparent from the following detailed description, which, when taken in conjunction with the drawings, illustrate by way of example the principles of the invention. 
     
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         [0012]      FIG. 1A  is a schematic diagram of a simplified tape drive system according to one embodiment. 
           [0013]      FIG. 1B  is a schematic diagram of a tape cartridge according to one embodiment. 
           [0014]      FIG. 2  illustrates a side view of a flat-lapped, bi-directional, two-module magnetic tape head according to one embodiment. 
           [0015]      FIG. 2A  is a tape bearing surface view taken from Line  2 A of  FIG. 2 . 
           [0016]      FIG. 2B  is a detailed view taken from Circle  2 B of  FIG. 2A . 
           [0017]      FIG. 2C  is a detailed view of a partial tape bearing surface of a pair of modules. 
           [0018]      FIG. 3  is a partial tape bearing surface view of a magnetic head having a write-read-write configuration. 
           [0019]      FIG. 4  is a partial tape bearing surface view of a magnetic head having a read-write-read configuration. 
           [0020]      FIG. 5  is a side view of a magnetic tape head with three modules according to one embodiment where the modules all generally lie along about parallel planes. 
           [0021]      FIG. 6  is a side view of a magnetic tape head with three modules in a tangent (angled) configuration. 
           [0022]      FIG. 7  is a side view of a magnetic tape head with three modules in an overwrap configuration. 
           [0023]      FIGS. 8A-8C  are partial top-down views of one module of a magnetic tape head according to one embodiment. 
           [0024]      FIGS. 9A-9C  are partial top-down views of one module of a magnetic tape head according to one embodiment. 
           [0025]      FIG. 10A  is a partial top-down view of a system with two modules according to one embodiment. 
           [0026]      FIG. 10B  is a diagram of the system of  FIG. 10A . 
           [0027]      FIG. 11A  is a partial top-down view of a system with two modules according to one embodiment. 
           [0028]      FIG. 11B  is a partial top-down view of a system with two modules according to another embodiment. 
           [0029]      FIG. 12  is a partial top-down view of a magnetic head with three modules according to one embodiment. 
           [0030]      FIG. 13  is a flow chart of a method according to one embodiment. 
           [0031]      FIG. 14A  is a representational diagram of a tape with shingled tracks written in a non-serpentine fashion according to one embodiment. 
           [0032]      FIG. 14B  is a representational diagram of a tape with shingled tracks written in a serpentine fashion according to one embodiment. 
           [0033]      FIG. 15A  is a representational diagram of a magnetic recording tape according to one embodiment. 
           [0034]      FIG. 15B  is a representational diagram of a magnetic recording tape according to another embodiment. 
           [0035]      FIG. 15C  is a representational diagram of a magnetic recording tape according to another embodiment. 
       
    
    
     DETAILED DESCRIPTION 
       [0036]    The following description is made for the purpose of illustrating the general principles of the present invention and is not meant to limit the inventive concepts claimed herein. Further, particular features described herein can be used in combination with other described features in each of the various possible combinations and permutations. 
         [0037]    Unless otherwise specifically defined herein, all terms are to be given their broadest possible interpretation including meanings implied from the specification as well as meanings understood by those skilled in the art and/or as defined in dictionaries, treatises, etc. 
         [0038]    It must also be noted that, as used in the specification and the appended claims, the singular forms “a,” “an” and “the” include plural referents unless otherwise specified. 
         [0039]    The following description discloses several preferred embodiments of magnetic storage systems, as well as operation and/or component parts thereof. 
         [0040]    In one general embodiment, an apparatus includes at least two modules, each of the modules having an array of transducers of a particular type selected from a group consisting of data readers and data writers. Each of the modules also has at least one servo reader. A centerline span of outermost transducers of each of the modules is at least 28% of a usable width of a tape for which the modules are designed. An axis of each array is defined between opposite ends thereof, the axes of the arrays being nominally oriented about parallel to each other. The transducers of each array are spatially arranged along the axis of the associated array such that adjacent pairs of the transducers along the axis have about a uniform separation. The array of a first of the modules is offset from the array of a second of the modules in a first direction parallel to the axis of the array of the second module such that the transducers of the first module are about aligned with the transducers of the second module in an intended direction of tape travel thereacross when the axes are oriented at an angle between greater than 0.2° relative to a line oriented perpendicular to the intended direction of tape travel thereacross. The apparatus also includes a mechanism for orienting the modules to control a transducer pitch presented to a tape. 
         [0041]    In one general embodiment, a product includes a magnetic recording tape having N servo tracks written thereon in a longitudinal direction. The magnetic recording tape in one approach has M=N or M=N+1 recordable regions thereon. In an alternate approach, the magnetic recording tape has M=N−1 recordable regions thereon when N is an integer less than 5. 
         [0042]    In another general embodiment, an apparatus includes at least two modules, each of the modules having an array of at least eight transducers selected from a group consisting of data readers and data writers. Each of the modules also has at least one servo reader. A centerline span of outermost transducers of each array is smaller than 10% of a width of a tape for which the modules are designed. The axis of each array is defined between opposite ends thereof, and the axes of the arrays are nominally oriented about parallel to each other. The transducers of each array are spatially arranged along the axis of the associated array such that adjacent pairs of the transducers along the axis have about a uniform separation. The array of a first of the modules is offset from the array of a second of the modules in a first direction parallel to the axis of the array of the second module such that the transducers of the first module are about aligned with the transducers of the second module in an intended direction of tape travel thereacross when the axes are oriented at an angle greater than 0.2° relative to a line oriented perpendicular to the intended direction of tape travel thereacross. The apparatus also includes a mechanism for orienting the modules to control a transducer pitch presented to a tape. 
         [0043]      FIG. 1A  illustrates a simplified tape drive  100  of a tape-based data storage system, which may be employed in the context of the present invention. While one specific implementation of a tape drive is shown in  FIG. 1A , it should be noted that the embodiments described herein may be implemented in the context of any type of tape drive system. 
         [0044]    As shown, a tape supply cartridge  120  and a take-up reel  121  are provided to support a tape  122 . One or more of the reels may form part of a removable cartridge and are not necessarily part of the system  100 . The tape drive, such as that illustrated in  FIG. 1A , may further include drive motor(s) to drive the tape supply cartridge  120  and the take-up reel  121  to move the tape  122  over a tape head  126  of any type. Such head may include an array of readers, writers, or both. 
         [0045]    Guides  125  guide the tape  122  across the tape head  126 . Such tape head  126  is in turn coupled to a controller  128  via a cable  130 . The controller  128 , may be or include a processor and/or any logic for controlling any subsystem of the drive  100 . For example, the controller  128  typically controls head functions such as servo following, data writing, data reading, etc. The controller  128  may operate under logic known in the art, as well as any logic disclosed herein. The controller  128  may be coupled to a memory  136  of any known type, which may store instructions executable by the controller  128 . Moreover, the controller  128  may be configured and/or programmable to perform or control some or all of the methodology presented herein. Thus, the controller may be considered configured to perform various operations by way of logic programmed into a chip; software, firmware, or other instructions being available to a processor; etc. and combinations thereof. 
         [0046]    The cable  130  may include read/write circuits to transmit data to the head  126  to be recorded on the tape  122  and to receive data read by the head  126  from the tape  122 . An actuator  132  controls position of the head  126  relative to the tape  122 . 
         [0047]    An interface  134  may also be provided for communication between the tape drive  100  and a host (integral or external) to send and receive the data and for controlling the operation of the tape drive  100  and communicating the status of the tape drive  100  to the host, all as will be understood by those of skill in the art. 
         [0048]      FIG. 1B  illustrates an exemplary tape cartridge  150  according to one embodiment. Such tape cartridge  150  may be used with a system such as that shown in  FIG. 1A . As shown, the tape cartridge  150  includes a housing  152 , a tape  122  in the housing  152 , and a nonvolatile memory  156  coupled to the housing  152 . In some approaches, the nonvolatile memory  156  may be embedded inside the housing  152 , as shown in  FIG. 1B . In more approaches, the nonvolatile memory  156  may be attached to the inside or outside of the housing  152  without modification of the housing  152 . For example, the nonvolatile memory may be embedded in a self-adhesive label  154 . In one preferred embodiment, the nonvolatile memory  156  may be a Flash memory device, ROM device, etc., embedded into or coupled to the inside or outside of the tape cartridge  150 . The nonvolatile memory is accessible by the tape drive and the tape operating software (the driver software), and/or other device. 
         [0049]    By way of example,  FIG. 2  illustrates a side view of a flat-lapped, bi-directional, two-module magnetic tape head  200  which may be implemented in the context of the present invention. As shown, the head includes a pair of bases  202 , each equipped with a module  204 , and fixed at a small angle α with respect to each other. The bases may be “U-beams” that are adhesively coupled together. Each module  204  includes a substrate  204 A and a closure  204 B with a thin film portion, commonly referred to as a “gap” in which the readers and/or writers  206  are formed. In use, a tape  208  is moved over the modules  204  along a media (tape) bearing surface  209  in the manner shown for reading and writing data on the tape  208  using the readers and writers. The wrap angle θ of the tape  208  at edges going onto and exiting the flat media support surfaces  209  are usually between about 0.1 degree and about 5 degrees. 
         [0050]    The substrates  204 A are typically constructed of a wear resistant material, such as a ceramic. The closures  204 B made of the same or similar ceramic as the substrates  204 A. 
         [0051]    The readers and writers may be arranged in a piggyback or merged configuration. An illustrative piggybacked configuration comprises a (magnetically inductive) writer transducer on top of (or below) a (magnetically shielded) reader transducer (e.g., a magnetoresistive reader, etc.), wherein the poles of the writer and the shields of the reader are generally separated. An illustrative merged configuration comprises one reader shield in the same physical layer as one writer pole (hence, “merged”). The readers and writers may also be arranged in an interleaved configuration. Alternatively, each array of channels may be readers or writers only. Any of these arrays may contain one or more servo track readers for reading servo data on the medium. 
         [0052]      FIG. 2A  illustrates the tape bearing surface  209  of one of the modules  204  taken from Line  2 A of  FIG. 2 . A representative tape  208  is shown in dashed lines. The module  204  is preferably long enough to be able to support the tape as the head steps between data bands. 
         [0053]    In this example, the tape  208  includes 4 to 22 data bands, e.g., with 8 data bands and 9 servo tracks  210 , as shown in  FIG. 2A  on a one-half inch wide tape  208 . The data bands are defined between servo tracks  210 . Each data band may include a number of data tracks, for example 1024 data tracks (not shown). During read/write operations, the readers and/or writers  206  are positioned to specific track positions within one of the data bands. Outer readers, sometimes called servo readers, read the servo tracks  210 . The servo signals are in turn used to keep the readers and/or writers  206  aligned with a particular set of tracks during the read/write operations. 
         [0054]      FIG. 2B  depicts a plurality of readers and/or writers  206  formed in a gap  218  on the module  204  in Circle  2 B of  FIG. 2A . As shown, the array of readers and writers  206  includes, for example, 16 writers  214 ,  16  readers  216  and two servo readers  212 , though the number of elements may vary. Illustrative embodiments include 8, 16, 32, 40, and 64 active readers and/or writers  206  per array, and alternatively interleaved designs having odd numbers of reader or writers such as 17, 25, 33, etc. An illustrative embodiment includes 32 readers per array and/or  32  writers per array, where the actual number of transducer elements could be greater, e.g., 33, 34, etc. This allows the tape to travel more slowly, thereby reducing speed-induced tracking and mechanical difficulties and/or execute fewer “wraps” to fill or read the tape. While the readers and writers may be arranged in a piggyback configuration as shown in  FIG. 2B , the readers  216  and writers  214  may also be arranged in an interleaved configuration. Alternatively, each array of readers and/or writers  206  may be readers or writers only, and the arrays may contain one or more servo readers  212 . As noted by considering FIGS.  2  and  2 A-B together, each module  204  may include a complementary set of readers and/or writers  206  for such things as bi-directional reading and writing, read-while-write capability, backward compatibility, etc. 
         [0055]      FIG. 2C  shows a partial tape bearing surface view of complimentary modules of a magnetic tape head  200  according to one embodiment. In this embodiment, each module has a plurality of read/write (R/W) pairs in a piggyback configuration formed on a common substrate  204 A and an optional electrically insulative layer  236 . The writers, exemplified by the write head  214  and the readers, exemplified by the read head  216 , are aligned parallel to a direction of travel of a tape medium thereacross to form an R/W pair, exemplified by the R/W pair  222 . 
         [0056]    Several R/W pairs  222  may be present, such as 8, 16, 32 pairs, etc. The R/W pairs  222  as shown are linearly aligned in a direction generally perpendicular to a direction of tape travel thereacross. However, the pairs may also be aligned diagonally, etc. Servo readers  212  are positioned on the outside of the array of R/W pairs, the function of which is well known. 
         [0057]    Generally, the magnetic tape medium moves in either a forward or reverse direction as indicated by arrow  220 . The magnetic tape medium and head assembly  200  operate in a transducing relationship in the manner well-known in the art. The piggybacked MR head assembly  200  includes two thin-film modules  224  and  226  of generally identical construction. 
         [0058]    Modules  224  and  226  are joined together with a space present between closures  204 B thereof (partially shown) to form a single physical unit to provide read-while-write capability by activating the writer of the leading module and reader of the trailing module aligned with the writer of the leading module parallel to the direction of tape travel relative thereto. When a module  224 ,  226  of a piggyback head  200  is constructed, layers are formed in the gap  218  created above an electrically conductive substrate  204 A (partially shown), e.g., of AlTiC, in generally the following order for the R/W pairs  222 : an insulating layer  236 , a first shield  232  typically of an iron alloy such as NiFe (-), CZT or Al—Fe—Si (Sendust), a sensor  234  for sensing a data track on a magnetic medium, a second shield  238  typically of a nickel-iron alloy (e.g., ˜80/20 at % NiFe, also known as permalloy), first and second writer pole tips  228 ,  230 , and a coil (not shown). The sensor may be of any known type, including those based on MR, GMR, AMR, tunneling magnetoresistance (TMR), etc. 
         [0059]    The first and second writer poles  228 ,  230  may be fabricated from high magnetic moment materials such as ˜45/55 NiFe. Note that these materials are provided by way of example only, and other materials may be used. Additional layers such as insulation between the shields and/or pole tips and an insulation layer surrounding the sensor may be present. Illustrative materials for the insulation include alumina and other oxides, insulative polymers, etc. 
         [0060]    The configuration of the tape head  126  according to one embodiment includes multiple modules, preferably three or more. In a write-read-write (W-R-W) head, outer modules for writing flank one or more inner modules for reading. Referring to  FIG. 3 , depicting a W-R-W configuration, the outer modules  252 ,  256  each include one or more arrays of writers  260 . The inner module  254  of  FIG. 3  includes one or more arrays of readers  258  in a similar configuration. Variations of a multi-module head include a R-W-R head ( FIG. 4 ), a R-R-W head, a W-W-R head, etc. In yet other variations, one or more of the modules may have read/write pairs of transducers. Moreover, more than three modules may be present. In further approaches, two outer modules may flank two or more inner modules, e.g., in a W-R-R-W, a R-W-W-R arrangement, etc. For simplicity, a W-R-W head is used primarily herein to exemplify embodiments of the present invention. One skilled in the art apprised with the teachings herein will appreciate how permutations of the present invention would apply to configurations other than a W-R-W configuration. 
         [0061]      FIG. 5  illustrates a magnetic head  126  according to one embodiment of the present invention that includes first, second and third modules  302 ,  304 ,  306  each having a tape bearing surface  308 ,  310 ,  312  respectively, which may be flat, contoured, etc. Note that while the term “tape bearing surface” appears to imply that the surface facing the tape  315  is in physical contact with the tape bearing surface, this is not necessarily the case. Rather, only a portion of the tape may be in contact with the tape bearing surface, constantly or intermittently, with other portions of the tape riding (or “flying”) above the tape bearing surface on a layer of air, sometimes referred to as an “air bearing”. The first module  302  will be referred to as the “leading” module as it is the first module encountered by the tape in a three module design for tape moving in the indicated direction. The third module  306  will be referred to as the “trailing” module. The trailing module follows the middle module and is the last module seen by the tape in a three module design. The leading and trailing modules  302 ,  306  are referred to collectively as outer modules. Also note that the outer modules  302 ,  306  will alternate as leading modules, depending on the direction of travel of the tape  315 . 
         [0062]    In one embodiment, the tape bearing surfaces  308 ,  310 ,  312  of the first, second and third modules  302 ,  304 ,  306  lie on about parallel planes (which is meant to include parallel and nearly parallel planes, e.g., between parallel and tangential as in  FIG. 6 ), and the tape bearing surface  310  of the second module  304  is above the tape bearing surfaces  308 ,  312  of the first and third modules  302 ,  306 . As described below, this has the effect of creating the desired wrap angle α 2  of the tape relative to the tape bearing surface  310  of the second module  304 . 
         [0063]    Where the tape bearing surfaces  308 ,  310 ,  312  lie along parallel or nearly parallel yet offset planes, intuitively, the tape should peel off of the tape bearing surface  308  of the leading module  302 . However, the vacuum created by the skiving edge  318  of the leading module  302  has been found by experimentation to be sufficient to keep the tape adhered to the tape bearing surface  308  of the leading module  302 . The trailing edge  320  of the leading module  302  (the end from which the tape leaves the leading module  302 ) is the approximate reference point which defines the wrap angle α z  over the tape bearing surface  310  of the second module  304 . The tape stays in close proximity to the tape bearing surface until close to the trailing edge  320  of the leading module  302 . Accordingly, read and/or write elements  322  may be located near the trailing edges of the outer modules  302 ,  306 . These embodiments are particularly adapted for write-read-write applications. 
         [0064]    A benefit of this and other embodiments described herein is that, because the outer modules  302 ,  306  are fixed at a determined offset from the second module  304 , the inner wrap angle α 2  is fixed when the modules  302 ,  304 ,  306  are coupled together or are otherwise fixed into a head. The inner wrap angle α 2  is approximately tan −1 (δ/W) where δ is the height difference between the planes of the tape bearing surfaces  308 ,  310  and W is the width between the opposing ends of the tape bearing surfaces  308 ,  310 . An illustrative inner wrap angle α 2  is in a range of about 0.5° to about 1.1°, though can be any angle required by the design. 
         [0065]    Beneficially, the inner wrap angle α 2  may be set slightly less on the side of the module  304  receiving the tape (leading edge) than the inner wrap angle α 3  on the trailing edge, as the tape  315  rides above the trailing module  306 . This difference is generally beneficial as a smaller α 3  tends to oppose what has heretofore been a steeper exiting effective wrap angle. 
         [0066]    Note that the tape bearing surfaces  308 ,  312  of the outer modules  302 ,  306  are positioned to achieve a negative wrap angle at the trailing edge  320  of the leading module  302 . This is generally beneficial in helping to reduce friction due to contact with the trailing edge  320 , provided that proper consideration is given to the location of the crowbar region that forms in the tape where it peels off the head. This negative wrap angle also reduces flutter and scrubbing damage to the elements on the leading module  302 . Further, at the trailing module  306 , the tape  315  flies over the tape bearing surface  312  so there is virtually no wear on the elements when tape is moving in this direction. Particularly, the tape  315  entrains air and so will not significantly ride on the tape bearing surface  312  of the third module  306  (some contact may occur). This is permissible, because the leading module  302  is writing while the trailing module  306  is idle. 
         [0067]    Writing and reading functions are performed by different modules at any given time. In one embodiment, the second module  304  includes a plurality of data and optional servo readers  331  and no writers. The first and third modules  302 ,  306  include a plurality of writers  322  and no readers, with the exception that the outer modules  302 ,  306  may include optional servo readers. The servo readers may be used to position the head during reading and/or writing operations. The servo reader(s) on each module are typically located towards the end of the array of readers or writers. 
         [0068]    By having only readers or side by side writers and servo readers in the gap between the substrate and closure, the gap length can be substantially reduced. Typical heads have piggybacked readers and writers, where the writer is formed above each reader. A typical gap is 25-35 microns. However, irregularities on the tape may tend to droop into the gap and create gap erosion. Thus, the smaller the gap is the better. The smaller gap enabled herein exhibits fewer wear related problems. 
         [0069]    In some embodiments, the second module  304  has a closure, while the first and third modules  302 ,  306  do not have a closure. Where there is no closure, preferably a hard coating is added to the module. One preferred coating is diamond-like carbon (DLC). 
         [0070]    In the embodiment shown in  FIG. 5 , the first, second, and third modules  302 ,  304 ,  306  each have a closure  332 ,  334 ,  336 , which extends the tape bearing surface of the associated module, thereby effectively positioning the read/write elements away from the edge of the tape bearing surface. The closure  332  on the second module  304  can be a ceramic closure of a type typically found on tape heads. The closures  334 ,  336  of the first and third modules  302 ,  306 , however, may be shorter than the closure  332  of the second module  304  as measured parallel to a direction of tape travel over the respective module. This enables positioning the modules closer together. One way to produce shorter closures  334 ,  336  is to lap the standard ceramic closures of the second module  304  an additional amount. Another way is to plate or deposit thin film closures above the elements during thin film processing. For example, a thin film closure of a hard material such as Sendust or nickel-iron alloy (e.g., 45/55) can be formed on the module. 
         [0071]    With reduced-thickness ceramic or thin film closures  334 ,  336  or no closures on the outer modules  302 ,  306 , the write-to-read gap spacing can be reduced to less than about 1 mm, e.g., about 0.75 mm, or 50% less than standard Linear Tape Open (LTO) tape head spacing. The open space between the modules  302 ,  304 ,  306  can still be set to approximately 0.5 to 0.6 mm, which in some embodiments is ideal for stabilizing tape motion over the second module  304 . 
         [0072]    Depending on tape tension and stiffness, it may be desirable to angle the tape bearing surfaces of the outer modules relative to the tape bearing surface of the second module.  FIG. 6  illustrates an embodiment where the modules  302 ,  304 ,  306  are in a tangent or nearly tangent (angled) configuration. Particularly, the tape bearing surfaces of the outer modules  302 ,  306  are about parallel to the tape at the desired wrap angle α 2  of the second module  304 . In other words, the planes of the tape bearing surfaces  308 ,  312  of the outer modules  302 ,  306  are oriented at about the desired wrap angle α 2  of the tape  315  relative to the second module  304 . The tape will also pop off of the trailing module  306  in this embodiment, thereby reducing wear on the elements in the trailing module  306 . These embodiments are particularly useful for write-read-write applications. Additional aspects of these embodiments are similar to those given above. 
         [0073]    Typically, the tape wrap angles may be set about midway between the embodiments shown in  FIGS. 5 and 6 . 
         [0074]      FIG. 7  illustrates an embodiment where the modules  302 ,  304 ,  306  are in an overwrap configuration. Particularly, the tape bearing surfaces  308 ,  312  of the outer modules  302 ,  306  are angled slightly more than the tape  315  when set at the desired wrap angle α 2  relative to the second module  304 . In this embodiment, the tape does not pop off of the trailing module, allowing it to be used for writing or reading. Accordingly, the leading and middle modules can both perform reading and/or writing functions while the trailing module can read any just-written data. Thus, these embodiments are preferred for write-read-write, read-write-read, and write-write-read applications. In the latter embodiments, closures should be wider than the tape canopies for ensuring read capability. The wider closures will force a wider gap-to-gap separation. Therefore a preferred embodiment has a write-read-write configuration, which may use shortened closures that thus allow closer gap-to-gap separation. 
         [0075]    Additional aspects of the embodiments shown in  FIGS. 6 and 7  are similar to those given above. 
         [0076]    A 32 channel version of a multi-module head  126  may use cables  350  having leads on the same pitch as current 16 channel piggyback LTO modules, or alternatively the connections on the module may be organ-keyboarded for a 50% reduction in cable span. Over-under, writing pair unshielded cables can be used for the writers, which may have integrated servo readers. 
         [0077]    The outer wrap angles α 1  may be set in the drive, such as by guides of any type known in the art, such as adjustable rollers, slides, etc. For example, rollers having an offset axis may be used to set the wrap angles. The offset axis creates an orbital arc of rotation, allowing precise alignment of the wrap angle α 1 . 
         [0078]    To assemble any of the embodiments described above, conventional u-beam assembly can be used. Accordingly, the mass of the resultant head can be maintained or even reduced relative to heads of previous generations. In other approaches, the modules may be constructed as a unitary body. Those skilled in the art, armed with the present teachings, will appreciate that other known methods of manufacturing such heads may be adapted for use in constructing such heads. 
         [0079]    As noted above, tape lateral expansion and contraction present many challenges to increasing data track density on conventional products. Conventional products have attempted to compensate for tape lateral expansion and contraction by controlling tape width by tension and improving the characteristics of the media itself. However, these methods fail to fully cancel the tape lateral expansion and contraction, and actually lead to other problems, including tape stretch and media cost increases, respectively. 
         [0080]      FIGS. 8A-8C  are intended to depict the effect of tape lateral expansion and contraction on transducer arrays position relative thereto, and are in no way intended to limit the invention.  FIG. 8A  depicts a module  800  relative to the tape  802 , where the tape has a nominal width. As shown, the transducers  804  are favorably aligned with the data tracks  806  on the tape  802 . However,  FIG. 8B  illustrates the effect of tape lateral contraction. As shown, contraction of the tape causes the data tracks to contract as well, and the outermost transducers  808  are positioned along the outer edges of the outer data tracks as a result. Moreover,  FIG. 8C  depicts the effect of tape lateral expansion. Here expansion of the tape causes the data tracks to move farther apart, and the outermost transducers  808  are positioned along the inner edges of the outer data tracks as a result. If the tape lateral contraction is greater than that shown in  FIG. 8B , or the tape lateral expansion is greater than that shown in  FIG. 8C , the outermost transducers  808  will cross onto adjacent tracks, thereby causing the adjacent tracks to be overwritten during a writing operation and/or resulting in readback of the wrong track during a readback operation. Moreover, running effects, such as tape skew and lateral shifting may exacerbate such problems, particularly for tape having shingled data tracks. 
         [0081]    Thus, it would be desirable to develop a tape drive system able to read and/or write tracks onto the tape in the proper position, regardless of the extent of tape lateral expansion and/or contraction at any given time. Various embodiments described and/or suggested herein overcome the foregoing challenges of conventional products, by orienting at least two modules of a tape drive system e.g., by pivoting, rotating and/or tilting, thereby selectively altering the pitch of the transducers in their arrays, as will soon become apparent. 
         [0082]    By selectively orienting a module, the pitch of the transducers on the module is thereby altered, preferably aligning the transducers with the tracks on a tape for a given tape lateral expansion and/or contraction. Tape contraction (shrinkage) can be dealt with by orienting a nominally non-offset head, but tape expansion (dilation) cannot. Thus, to accommodate both shrinkage and dilation about a “nominal: the head must be statically oriented at a nominal angle of at least approximately 0.2° as will be explained below. Thereafter, smaller angular adjustments (e.g., about 1° or lower, but could be more) may be made to the already oriented module in order to compensate for any variation of the tape lateral expansion and/or contraction, thereby keeping the transducers aligned with tracks on the tape. 
         [0083]      FIGS. 9A-9C  illustrate representational views of the effects of orienting a module having transducer arrays. It should be noted that the angles of orientation illustrated in  FIGS. 9A-9C  are an exaggeration (e.g., larger than would typically be observed), and are in no way intended to limit the invention. 
         [0084]    Referring to  FIG. 9A , the module  900  is shown relative to the tape  902 , where the tape has a nominal width. As illustrated, the module  900  is oriented at an angle θ nom  such that the transducers  904  are favorably aligned with the data tracks  906  on the tape  902 . However, when the tape  902  experiences tape lateral contraction and/or expansion, the data tracks  906  on the tape contract and/or expand as well. As a result, the transducers on the module are no longer favorably aligned with the data tracks  906  on the tape  902 . 
         [0085]    In  FIG. 9B , the tape  902  has experienced tape lateral contraction. Therefore, in a manner exemplified by  FIG. 8B , the transducers  904  on the module  900  of  FIG. 9B  would no longer be favorably aligned with the data tracks  906  on the tape  902  if no adjustment were made. However, as alluded to above, smaller angular adjustments may be made to the already-oriented module  900  in order to compensate for tape lateral contraction. Therefore, referring again to  FIG. 9B , the angle of orientation &gt;θ nom  of the module  900  is further oriented to an angle greater than θ nom . By increasing the angle of orientation &gt;θ nom  the effective width w 2  of the array of transducers decreases from the effective width w 1  illustrated in  FIG. 9A . This also translates to a reduction in the effective pitch between the transducers, thereby realigning the transducers along the contracted data tracks  906  on the tape  902  as shown in  FIG. 9B . 
         [0086]    On the other hand, when the tape experiences tape lateral expansion, the data tracks on the tape expand as well. As a result, the transducers on the module would no longer be favorably aligned with the data tracks on the tape if no adjustments were made. With reference to  FIG. 9C , the tape  902  has experienced tape lateral expansion. As a result, further angular adjustments may be made to the angle of orientation of the module in order to compensate for the tape lateral expansion. Therefore, referring again to  FIG. 9C , the angle of orientation &lt;θ nom  of the module  900  is reduced to an angle less than θ nom . By decreasing the angle of orientation &lt;θ nom  the effective width w 3  of the array of transducers  904  increases from the effective width w 1  illustrated in  FIG. 9A . Moreover, reducing the effective width of the array of transducers  904  also causes the effective pitch between the transducers to be reduced, thereby realigning the transducers along the data tracks  906  on the tape  902 . 
         [0087]    In a preferred approach, magnetic tape systems have two or more modules, each having an array of transducers, typically in a row. Depending on the desired embodiment, the additional rows of transducers may allow the system to read verify during the write process, but is not limited thereto. As mentioned above, the foregoing conventional challenges may be overcome by tilting a given module, thereby selectively altering the pitch of the transducers in the array. 
         [0088]    By providing a system that compensates for tape lateral expansion and/or contraction, various embodiments enable use of wider readers, resulting in a better signal to noise ratio (SNR), and/or smaller data tracks, resulting in a higher capacity per unit area of the media. 
         [0089]      FIGS. 10A-10B  depict a system  1000  for compensating for tape lateral expansion and/or contraction, in accordance with one embodiment. As an option, the present system  1000  may be implemented in conjunction with features from any other embodiment listed herein, such as those described with reference to the other FIGS. Of course, however, system  1000  and others presented herein may be used in various applications and/or in permutations which may or may not be specifically described in the illustrative embodiments listed herein. Further, the system  1000  presented herein may be used in any desired environment. 
         [0090]    Referring to  FIGS. 10A-10B , the system  1000  includes modules  1002 ,  1004 , each of which have an array  1006 ,  1008  of transducers  1010 . The modules  1002 ,  1004 , are preferably fixed relative to each other. In view of the present description, “fixed” is intended to mean constrained from a directional movement relative to each other such that the arrays of each maintain a fixed position relative to each other. According to various approaches, the modules may be fixed relative to each other by using rods, fasteners, adhesives, cables, wire, etc. Moreover, according to different embodiments, the modules are preferably fixed relative to each other prior to being installed in the system  1000 , head, etc. depending on the desired embodiment. However, the modules are preferably selectively orientable (e.g., rotatable) as a single structure about a pivot point while remaining fixed relative to each other, as will soon become apparent. 
         [0091]    With continued reference to  FIGS. 10A-10B , the modules  1002 ,  1004 , are preferably fixed such that the axes  1012 ,  1013  of the arrays  1006 ,  1008  are oriented about parallel to each other, respectively. As illustrated in  FIGS. 10A-10B , the axes  1012 ,  1013  of each array of transducers are defined by the dashed lines that lie between opposite ends thereof, e.g., positioned farthest apart. 
         [0092]    Referring now to  FIG. 10A , the array  1006  of a first module  1002  is offset from the array  1008  of a second module  1004  in a first direction parallel to the axis  1013  of the array  1008  of the second module  1004 . The modules  1002 ,  1004  are also set to a nominal angle in the drive so that the transducers of the arrays are aligned along the data tracks  906  on a tape  902  having nominal tape lateral expansion. 
         [0093]    With continued reference to  FIG. 10A , the arrays  1006 ,  1008  of the transducers  1010  of the first and second modules are preferably offset such that the transducers  1010  of the first module  1002  are about aligned with the transducers  1010  of the second module  1004  in an intended direction  1020  of tape travel thereacross when the axes are oriented at an angle φ between greater than about 0.05°, more preferably greater than about 0.2°, in some approaches between 0.2° and about 10°, and ideally between about 0.25° and about 6°, relative to a line  1022  oriented perpendicular to the intended direction  1020  of tape travel. 
         [0094]    In addition, the inventors have surprisingly and unexpectedly found that the various embodiments described below, and having the angle γ in the range between greater than about 0.2° and about 10°, enable writing and reading that does not steer the tape or cause media damage over the life of the tape. For example, the inventors expected the skiving edges of the modules to steer the tape laterally. 
         [0095]    Angles of orientation greater than within the specified range (e.g., greater than about 10°) are undesirable as the higher angles cause steering of the tape when used. However, as described above, the angles of orientation within the specified range unexpectedly and unforeseeably did not result in steering of the tape. Moreover, it is more difficult to distinguish between tape lateral expansion and/or contraction and skew when angles of orientation of the modules are greater than within the specified range. This may cause difficulties when matching the dimensional conditions of the tape and/or titling state of the modules of the current operation to that of the previous operation (explained in further detail below). It should also be noted that the angle of orientation φ illustrated in  FIG. 10A  is exaggerated (e.g., larger than within the desired range), and is in no way intended to limit the invention. 
         [0096]    Depending on the desired embodiment, the modules themselves may be offset to effect the shifting of the transducer arrays, e.g., as shown by the offset (offset) in  FIG. 10B . Alternatively, the transducer arrays may be positioned on the respective module in a specified position to effect the offset while the modules themselves are not offset in the drive; or combinations thereof. 
         [0097]    With continued reference to  FIG. 10B , the system  1000  includes a mechanism  1014 , such as a tape dimensional instability compensation mechanism, for orienting the modules to control a transducer pitch presented to a tape. The tape dimensional instability compensation mechanism  1014  preferably allows for the orientation of the modules to be done while the modules are reading and/or writing. The tape dimensional instability compensation mechanism  1014  may be any known mechanism suitable for orienting the modules. Illustrative tape dimensional instability compensation mechanisms  1014  include worm screws, voice coil actuators, thermal actuators, piezoelectric actuators, etc. 
         [0098]    A controller  1016  in one approach is configured to control the tape dimensional instability compensation mechanism  1014  based on a readback signal of the tape, e.g., servo signals, data signals, a combination of both, etc. In another approach, the dimensional conditions of the tape and/or titling state of the modules when the tape was written may be retrieved e.g., from a database, cartridge memory, etc., and the orientation may be set based thereon to about match the transducer pitch of the current operation to that of the previous operation. 
         [0099]    In various approaches, additional logic, computer code, commands, etc., or combinations thereof, may be used to control the tape dimensional instability compensation mechanism  1014  for adjusting the orientation of the modules based on a skew of the tape. Moreover, any of the embodiments described and/or suggested herein may be combined with various functional methods, depending on the desired embodiment. 
         [0100]      FIG. 11A  depicts a system  1100  for compensating for tape lateral expansion and/or contraction, in accordance with one embodiment. The illustrative embodiment depicted in  FIG. 11A  may be considered a variation of system  1000  of  FIG. 10A  and therefore includes common numbering to represent common aspects therebetween. 
         [0101]    The system  1100  of  FIG. 11A , according to an exemplary embodiment, includes at least two modules  1002 ,  1004 , each of the modules  1002 ,  1004  having an array  1006 ,  1008  of at least eight transducers  1010  respectively. According to different approaches, the transducers  1010  may be of a particular type selected from a group consisting of data readers and data writers, i.e., at least eight data readers in one of the arrays  1006 ,  1008 , or at least eight data writers in one of the arrays  1006 ,  1008 . Preferably, the at least eight transducers  1010  are included regardless of whether or not another type of transducer is present, e.g., as in a piggyback transducer array, which, according to one example, may have eight data readers and eight data writers. Moreover, one array may have transducers of the data writer type, while the other array may have transducers of the data reader type. 
         [0102]    Additionally, each of the modules  1002 ,  1004  has servo readers  1102  positioned towards opposite ends of the associated array  1006 ,  1008 . According to various approaches, the servo readers  1102  may include any of the approaches described in detail above with reference to the configuration, orientation relative to the tape, etc. of the servo readers  212  of  FIG. 2B . With continued reference to  FIG. 11A , a centerline span (center to center spacing), referred to herein as the pitch P of the servo readers  1102  of each of the modules  1002 ,  1004  is at least 28% of a usable width of a tape (not shown) for which the modules  1002 ,  1004  are designed, i.e., a tape compatible with the drive having the modules. Accordingly, this wide pitch translates to a desirable reduction in the number of data bands for the tape, as will be discussed in further detail below. 
         [0103]    Note that the usable width of the tape is definable as that portion of the tape where an average magnetic spacing between the tape and the tape bearing surface of the head of any LTO 6 tape drive during run time is less than 100 nm. The region of the tape within the usable width is deemed usable space. Tape curl at the tape edges during such operation creates the aforementioned magnetic spacing, rendering the edges of the tape unusable for reliable recording. 
         [0104]    An axis  1012 ,  1013  of each array  1006 ,  1008  is defined between opposite ends thereof, and the axes  1012 ,  1013  of the arrays  1006 ,  1008  are nominally oriented about parallel to each other. Moreover, the transducers  1010  of each array  1006 ,  1008  are spatially arranged along the axis  1012 ,  1013  of the associated array  1006 ,  1008  such that adjacent pairs of the same type of transducers  1010  (e.g., the writers) along the axis  1012 ,  1013  have about a uniform separation therebetween. 
         [0105]    With continued reference to  FIG. 11A , the array  1006  of a first  1002  of the modules is offset from the array  1008  of a second  1004  of the modules in a first direction parallel to the axis  1013  of the array  1008  of the second module  1004 . The array  1006  is preferably offset such that the transducers  1010  of the first module  1002  are about aligned with the transducers  1010  of the second module  1004  in the intended direction of tape travel  1020  thereacross when the axes are oriented at an angle φ (e.g., see  FIGS. 9A-9C ). In a preferred approach, the angle φ may be between greater than about 0.2° and about 10° relative to a line oriented perpendicular to the intended direction  1020  of tape travel thereacross as illustrated, but may be higher or lower depending on the desired embodiment. 
         [0106]    The system  1100  may also include a mechanism (not shown) for setting the angle φ of the modules to control a transducer pitch P presented to a tape. Such mechanism may be of a type known in the art and may include any of the designs described in detail above with reference to the tape dimensional instability compensation mechanism  1014  of  FIG. 10B . 
         [0107]    Although not shown, the system  1100  of  FIG. 11A  may also include a controller configured to control the mechanism for orienting the modules  1002 ,  1004  based on a state of expansion of the tape. Thus, in a preferred approach, the controller may be electrically coupled to the device, e.g., via a wire, cable, bus, etc. According to a number of approaches, the controller may include any of the approaches described in detail above with reference to controller  1016  of  FIG. 10B . Moreover, a method for orienting the modules is described below with reference to method  1300 . 
         [0108]    In a preferred approach, only two modules are present, though various embodiments may have three or more modules, e.g., see  FIG. 12 . In such embodiments having three or more modules, according to some approaches, the multiple modules may have the same or similar configuration to those described and/or suggested herein, depending on the desired design. 
         [0109]    Referring again to  FIG. 11A , each array  1006 ,  1008  may have at least sixteen transducers  1010  of the particular type, e.g., readers or writers as described above. However, another approach may have at least thirty two transducers  1010  of the particular type in each array  1006 ,  1008 . In yet another approach, each array  1006 ,  1008  may have at least sixty four transducers  1010  of the particular type. 
         [0110]    Furthermore, contrary to conventional wisdom, the transducers illustrated in  FIG. 11A  are preferably spaced apart such that the pitch therebetween is widened, which thereby reduces the number of data bands of the head for a given tape, e.g., from those of a normal head. Moreover, a widened pitch as mentioned above may preferably be about 20 μm, more preferably about 30 μm, still more preferably about 40 μm wider than that of a normal head. According to the present description, without wishing to be bound by any theory, a “normal head” may include a ½ inch tape with 4 data bands and a 16 channel head having s transducer pitch of 166.5 μm. 
         [0111]    By increasing the transducer pitch and thereby reducing the number of data bands writable on a tape, the mechanism (e.g., the tape dimensional instability compensation mechanism  1014  of  FIG. 10B ) may make smaller movements to compensate for tape lateral expansion, contraction, skew, etc., than for a “normal head”, thereby resulting in fewer databand switches. Thus, the reduction in databand switches results in less time spent reacquiring servo lock after each data band switch. Additionally, the increased transducer pitch desirably reduces crosstalk on the head as signals from neighboring transducers are reduced by the increased separation therebetween, thereby improving writing and/or reading operations. 
         [0112]    Thus, according to one embodiment, the pitch P of the servo readers  1102  of each of the modules  1002 ,  1004  may preferably be at least 29% of a width of a tape, more preferably at least 40% of a usable width of a tape for which the modules  1002 ,  1004  are designed. Generally, this pitch allows inclusion of up to two data bands on the tape, however, in another approach, the magnetic recording tape may have no more than three servo tracks written thereon. In another approach, the centerline span of the outermost of the transducers of each of the modules is at least 80% of the usable width of a tape for which the modules are designed. 
         [0113]    The tape used with the foregoing system may be of a type known in the art, but modified to be usable with the embodiments described herein. For example, the tape may have a width of about one half inch, but the width in various embodiments may be higher or lower. The following description describes one embodiment of a product having a magnetic recording tape, which is in no way intended to limit the invention. 
         [0114]    A product according to one exemplary embodiment includes a magnetic recording tape having N servo tracks written thereon in a longitudinal direction, e.g., about parallel to a longitudinal axis of the tape, or equivalently, about parallel to the tape travel direction. Each servo track may be of a type known in the art, e.g., comprised of a series of magnetically defined bars arranged along the servo track. The magnetic recording tape also has M=N or M=N+1 recordable regions thereon. The recordable regions are defined as usable portions of the tape where user data can be recorded and/or read back. For example, the recordable regions can be defined as those regions not in a servo track and where an average magnetic spacing between the tape and the tape bearing surface of the head of an LTO 6 tape drive during run time is less than 100 nm. 
         [0115]    In various approaches, number N of servo tracks is four or less. 
         [0116]      FIG. 15A  depicts an embodiment of a magnetic recording tape  1500  where the number N of servo tracks  1502  is four, with M=5 recordable regions  1504 . 
         [0117]      FIG. 15B  depicts an embodiment of a magnetic recording tape  1510  where the number N of servo tracks  1502  is one, with M=2 recordable regions  1504 . 
         [0118]    In a further approach, the number M of recordable regions of the magnetic recording tape is N−1 when N is an integer less than 5.  FIG. 15C  depicts such an embodiment of a magnetic recording tape  1520  where the number M of recordable regions  1504  of the magnetic recording tape is N−1 when the number N of servo tracks  1502  is an integer less than 5. In the embodiment shown, N=2. 
         [0119]    A product according to another exemplary embodiment includes a magnetic recording tape having at least two, but no more than four servo tracks written thereon. Moreover, according to the present embodiment, the data bands are defined between adjacent pairs of the servo tracks. A recording layer of the magnetic recording tape is physically characterized as enabling writing data tracks with a track width of smaller than 1/255 of a width of the magnetic recording tape. According to various approaches, any suitable type of recording layer known in the art may be used in the magnetic recording tape, such as those presently used for LTO-4 tape cartridges. 
         [0120]    According to one approach, the recording layer of the magnetic recording tape may be physically characterized as enabling writing data tracks with a track width of smaller than 1/1055 of the width of the magnetic recording tape. 
         [0121]    According to another exemplary embodiment, a system, similar to  1100  of  FIG. 11A , may include at least two modules, each of which may have servo readers positioned towards opposite ends of the associated array. Moreover, the pitch (center to center spacing) of the servo readers of each of the modules may be smaller than 10% of a width of a tape for which the modules are designed, i.e., a tape compatible with the drive having the modules. Generally, this pitch would require at least 9 or 10 data bands on the tape. According to another approach, the pitch of the servo readers of each of the modules may be less than 5% of the width of a tape for which the modules are designed. 
         [0122]    As a result, the smaller transducer pitch and increased number of data bands resulting therefrom allow for a near perfect cancelation of data miss-tracking. Thus, according to one approach, a combination of orienting the arrays at an angle and smaller data bands as a result of a smaller pitch of the servo readers and/or transducers produces a desirable increase in available area on the tape for storing data thereto. 
         [0123]      FIG. 11B  depicts an apparatus  1150  that is a variation of the embodiment shown in  FIG. 11A , and has common numbering therewith to represent similar components. Referring to  FIG. 11B , the servo reader  1102  of each module  1002 ,  1004  is positioned towards the center of the associated array. A centerline span, or pitch P, of outermost transducers of each of the modules is at least 28% of a usable width of a tape for which the modules are designed. 
         [0124]    While the illustrative embodiment of  FIG. 11B  depicts the servo reader  1102  of each module  1002 ,  1004  is positioned towards the center of the associated array, the servo reader may be positioned anywhere along the associated array. 
         [0125]    Moreover, more than one servo reader may be associated with one or more of the arrays. For example, two or more servo readers may be positioned between lines extending along the outer transducers of any array. In another approach, one or more servo readers may be positioned between lines extending along the outer data transducers of any array, and one or more servo readers may be positioned outside said lines. 
         [0126]    In addition, three or more modules may be present. 
         [0127]      FIG. 13  depicts a method  1300  for orienting modules having transducers, in accordance with one embodiment. Such method  1300  may be implemented by the controller  1016  of  FIG. 10B , but is not limited thereto. As an option, the present method  1300  may be implemented in conjunction with features from any other embodiment listed herein, such as those described with reference to the other FIGS. Of course, however, such method  1300  and others presented herein may be used in various applications and/or in permutations which may or may not be specifically described in the illustrative embodiments listed herein. Further, the method  1300  presented herein may be used in any desired environment. 
         [0128]    Referring now to  FIG. 13 , the method  1300  includes determining a desired pitch for transducers for reading and/or writing to a magnetic tape as illustrated in operation  1302 . By determining a desired pitch for the transducers, the modules may effectively compensate for any tape expansion, contraction, skew, etc. as demonstrated in  FIGS. 9A-9C . 
         [0129]    In one approach, the desired pitch may be determined by the state of the tape. An exemplary mechanism for establishing the proper pitch is to use the timing interval read by two servo readers to determine the state of the tape, e.g., contracted, expanded or nominal. Although a preferred mode is to use servo data, this is not absolutely required. Thus, it may be desirable to determine the state of the tape, e.g., by incorporating any of the approaches described and/or suggested herein and/or known processes, when determining the desired pitch. However, according to other approaches, the pitch may be determined using any approach described and/or suggested herein, or combinations thereof. 
         [0130]    Method  1300  further includes orienting a head to achieve the desired pitch, the head having at least two opposing modules generally aligned with each other in a(n intended) direction of tape travel thereacross, positions of the two modules being fixed relative to each other, each module having an array of the transducers, where an axis of each array is defined between opposite ends thereof, where the array of a first of the modules is offset from the array of a second of the modules in a first direction parallel to the axis of the array of the second module such that the transducers of the first module are about aligned with the transducers of the second module in a direction of tape travel thereacross when the axes are oriented at an angle between greater than 0.2° and about 10° relative to a line oriented perpendicular to the direction of tape travel. See operation  1304 . 
         [0131]    In one approach, steps  1302  and  1304  may be performed concurrently. For example, in one embodiment the proper transducer pitch may be based on data signals. One way to implement this is by first setting the transducer pitch at a nominal value by selecting a nominal angle of orientation, and then adjusting the orientation thereof to obtain a better readback quality across the read channels. The quality may be determined for example by finding the lowest error rate, best signal to noise level, etc. 
         [0132]    As an option, the system may continue or periodically monitor the appropriate signals and adjust the angle of orientation. Adjustments can be performed any time, such as during an initialization period prior to reading or writing user data, during readback or writing operations, etc. 
         [0133]    Although two modules  1002 ,  1004  are illustrated in  FIGS. 10A-11 , in other approaches, a system may include any number of modules e.g., at least two, at least three, at least four, a plurality, etc. depending on the desired embodiment. Referring to the illustrative embodiment depicted in  FIG. 12 , which may be considered a modification of system  1000  of  FIG. 10A  and therefore includes common numbering therewith, the system  1200  shown may include a third module  1202  positioned between the first and second modules  1002 ,  1004 . As shown, the array of transducers of the third module  1202  is preferably offset from the array of the first module  1002  in a first direction  1204 . Moreover, the extent of the offset t 1  of the array of the third module  1202  relative to the array of the first module  1002  is less than an extent of the offset t 2  of the array of the second module  1004  relative to the array of the first module  1002 . 
         [0134]    According to different approaches, the first second and/or third modules  1002 ,  1004 ,  1202  may be used for data writing and/or data reading, depending on the desired embodiment. Thus, the system  1200  may serve as a write-read-write (WRW) device if the first and second modules  1002 ,  1004  are designed for at least data writing and the third module  1202  is designed for at least data reading. As an option, the first and second modules  1002 ,  1004  may be designed for data writing and not for data reading, and/or the third module  1202  maybe designed for data reading and not for data writing. 
         [0135]    In another approach, the system  1200  may serve as a read-write-read (RWR) device if the first and second modules  1002 ,  1004  are designed for at least data reading and optionally not for data writing, while the third module  1202  is designed for at least data writing and optionally not for data reading. However, this is in no way meant to limit the invention; according to various other approaches, a third, fourth, fifth, etc. module may be positioned with any orientation relative to other modules of the system, depending on the desired embodiment. 
         [0136]    With continued reference to  FIG. 12 , according to one approach, the angle of orientation φ of the modules  1002 ,  1202 ,  1004  and distance y between the arrays may be used to calculate the offset x. As illustrated, the offset x is between the arrays of transducers of the modules in a direction parallel to their axes  1012 ,  1206 , which may be calculated using Equation 1. 
         [0000]      tan(φ)= x/y   Equation 1
 
         [0137]    Equation 1 can be rewritten into Equation 2. 
         [0000]        y (tan(φ))= x   Equation 2
 
         [0138]    Other known methods of calculating and/or assigning the offset x and distance y between the arrays of any of the modules may be used in other embodiments. 
         [0139]    According to other approaches, a three module head may also allow for non-serpentine and/or serpentine writing. Referring still to  FIG. 12 , according to another illustrative approach, the modules  1002 ,  1202 ,  1004  may have a RWR configuration (e.g., the data transducers  1010  of the first and second modules  1002 ,  1004  may include readers, wherein the data transducers of the third array  1202  may include writers). Using a RWR configuration for a three module head allows for non-serpentine writing, whereby the same writer array writes each adjoining data track, despite reversal of the tape direction while writing thereto. This may reduce writing errors, readback errors, data loss, etc., as well as reducing the misregistration budgeting requirements, as only one set of track tolerances comes into play. Moreover, using the same writer array to write adjoining data tracks ensures consistency while writing (e.g., by enabling symmetrical servo pattern reading), overall higher areal density, etc. 
         [0140]    Thus, as illustrated in the representational diagram of  FIG. 14A , which is in no way intended to limit the invention, the angles or orientation of the magnetic transitions on the tape  902  may be different such that the magnetic transitions written in the shingled data tracks  1402  in one direction are at a different angle than the magnetic transitions in shingled data tracks  1404  written in the opposite direction. Moreover, when reading a data track, the reader array may be oriented to about match the angle of the written transitions of each shingled data track to read the data thereon. Thus, if the reader array drifts over one of the adjacent data tracks, the off-track reading rejection SNR is reduced, because the angle of orientation of the magnetic transitions on the adjacent data track will not match the angle of orientation of the read array. 
         [0141]    Note that, while not ideal, a WRW configuration could be used for non-serpentine writing in some approaches. 
         [0142]    Referring again to  FIG. 12 , according to another illustrative approach, the modules  1002 ,  1202 ,  1004  may have a WRW configuration (e.g., the data transducers  1010  of the first and second modules  1002 ,  1004  may include writers, wherein the data transducers of the third array  1202  may include readers), for conducting serpentine writing. While writing data with a WRW configuration, the leading writer and reader may preferably be active, while the trailing writer is not active, depending on the intended direction of tape travel. As a result, the leading writer array may be used to write adjoining data tracks for one direction of tape travel, while the trailing writer array may be used to write adjoining data tracks for the other direction of tape travel. 
         [0143]    Thus, as illustrated in the representational diagram of  FIG. 14B , which is in no way intended to limit the invention, the angles of orientation of the magnetic transitions on the tape  902  may be about the same for shingled data tracks  1402  written in a first direction of tape travel, but different than the angles of orientation of the magnetic transitions in the shingled data tracks  1404  written during the opposite direction of tape travel. This preferably reduces writing errors, readback errors, data loss, etc. and ensures consistency while writing, e.g., by enabling symmetrical servo pattern reading. 
         [0144]    According to yet another approach, the arrays may have a RWR configuration as described above, for conducting serpentine writing. While writing data with a RWR configuration, the writer and corresponding trailing reader may preferably be active, while the leading reader is not active, depending on the direction of tape travel. As a result, the same writer may be used to write each adjoining data track for both directions of tape travel, despite reversal thereof while writing. 
         [0145]    It will be clear that the various features of the foregoing systems and/or methodologies may be combined in any way, creating a plurality of combinations from the descriptions presented above. 
         [0146]    As will be appreciated by one skilled in the art, aspects of the present invention may be embodied as a system, method or computer program product. Accordingly, aspects of the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment (including firmware, resident software, micro-code, etc.) or an embodiment combining software and hardware aspects that may all generally be referred to herein as “logic,” a “circuit,” “module,” or “system.” Furthermore, aspects of the present invention may take the form of a computer program product embodied in one or more computer readable medium(s) having computer readable program code embodied thereon. 
         [0147]    Any combination of one or more computer readable medium(s) may be utilized. The computer readable medium may be a computer readable signal medium or a non-transitory computer readable storage medium. A computer readable storage medium may be, for example, but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples (a non-exhaustive list) of the non-transitory computer readable storage medium include the following: a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), a portable compact disc read-only memory (e.g., CD-ROM), a Blu-ray disc read-only memory (BD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. In the context of this document, a non-transitory computer readable storage medium may be any tangible medium that is capable of containing, or storing a program or application for use by or in connection with an instruction execution system, apparatus, or device. 
         [0148]    A computer readable signal medium may include a propagated data signal with computer readable program code embodied therein, for example, in baseband or as part of a carrier wave. Such a propagated signal may take any of a variety of forms, including, but not limited to, electro-magnetic, optical, or any suitable combination thereof. A computer readable signal medium may be any computer readable medium that is not a non-transitory computer readable storage medium and that can communicate, propagate, or transport a program for use by or in connection with an instruction execution system, apparatus, or device, such as an electrical connection having one or more wires, an optical fibre, etc. 
         [0149]    Program code embodied on a computer readable medium may be transmitted using any appropriate medium, including but not limited to wireless, wireline, optical fibre cable, RF, etc., or any suitable combination of the foregoing. 
         [0150]    Computer program code for carrying out operations for aspects of the present invention may be written in any combination of one or more programming languages, including an object oriented programming language such as Java, Smalltalk, C++ or the like and conventional procedural programming languages, such as the “C” programming language or similar programming languages. The program code may execute entirely on the user&#39;s computer, partly on the user&#39;s computer, as a stand-alone software package, partly on the user&#39;s computer and partly on a remote computer or entirely on the remote computer or server. In the latter scenario, the remote computer may be connected to the user&#39;s computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or the connection may be made to an external computer, for example through the Internet using an Internet Service Provider (ISP). 
         [0151]    Aspects of the present invention are described herein with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems) and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks. 
         [0152]    These computer program instructions may also be stored in a computer readable medium that can direct a computer, other programmable data processing apparatus, or other devices to function in a particular manner, such that the instructions stored in the computer readable medium produce an article of manufacture including instructions which implement the function/act specified in the flowchart and/or block diagram block or blocks. 
         [0153]    The computer program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other devices to cause a series of operational steps to be performed on the computer, other programmable apparatus or other devices to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide processes for implementing the functions/acts specified in the flowchart(s) and/or block diagram block or blocks. 
         [0154]    It will be further appreciated that embodiments of the present invention may be provided in the form of a service deployed on behalf of a customer. 
         [0155]    While various embodiments have been described above, it should be understood that they have been presented by way of example only, and not limitation. Thus, the breadth and scope of an embodiment of the present invention should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims and their equivalents.