JP2006172705A - System including write head matrix array and magneto-resistance (mr) read head matrix array - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a system including a write head matrix array and a magneto-resistance (MR) read head matrix array. <P>SOLUTION: In the system equipped with the nonlinear array of magneto-resistance heads arrayed in a two-dimensional matrix for reading information stored in a magnetic medium, the nonlinear array of the MR heads is provided with a planar array constituted of a plurality of linear arrays of MR heads stacked to define a plurality of layers. Each linear array shares at least one shield element with the other linear array of the nonlinear array. Generally, each layer is shifted by one writing pitch, and the number of layers is equal to the number of writing pitches. This matrix array is used in a system for reading/writing information in a magnetic medium by a track pitch improved as compared with a conventional reading/writing system. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present application was filed on January 8, 2004 by Yip, "System with Matrix Array of Write Heads and Array of Magnetoresistive (MR) Read Heads (System with Matrix Array of Write Heads and Array). of Magnetoreactive (MR) Read Heads), which is a continuation-in-part of U.S. Patent Application Serial No. 10 / 755,143, filed 10 / 755,143 by reference number 10426US01. No. 143 is incorporated herein by reference in its entirety.

  The present invention relates to magnetic data storage media, and more particularly to magnetic heads for reading and writing data to such media.

  Magnetic data storage media are commonly used for data storage and retrieval and come in many forms, such as magnetic tape, magnetic disk, and the like. Magnetic tape media is still an economical medium for storing large amounts of data. For example, a large amount of data for a large-scale computing center is often backed up using, for example, a magnetic tape cartridge or a large spool magnetic tape. Magnetic tape cartridges also find use in backing up data stored on small computers such as workstations, desktops or laptop computers.

  Within magnetic tape, data is typically stored as magnetic signals that are magnetically recorded on the medium surface. Data stored on magnetic tape is often organized along a data track, and a read / write head is positioned relative to the data track to write data to the track or read data from the track. As the number of data tracks increases, the data storage capacity of the magnetic tape increases as well. However, as the number of data tracks increases, the tracks are usually narrow and become crowded on the surface of the data storage tape. Servo tracks are also typically defined on the magnetic medium to provide a reference point for tracking the position of the data track.

Various heads have been designed for writing data to magnetic media. Various heads have been designed to read data stored on magnetic media. Magnetic data storage systems often include both a write head and a read head to facilitate writing information to and reading such information from a magnetic medium (see Patent Document 1).
US Patent Application Publication No. 2003/0011922

  In general, the present invention provides a system for reading information stored on a magnetic medium. This system utilizes a non-linear array of magnetoresistive (MR) heads arranged in a two-dimensional matrix. Each of the MR heads of the non-linear array defines the read channel of the system. The nonlinear array of MR heads may comprise a planar array of MR heads formed by a plurality of linear arrays of MR heads stacked to define a plurality of layers of nonlinear arrays. Each of the linear arrays of MR heads that define the layers of the nonlinear array may share at least one shield element with other linear arrays of the nonlinear array. In other words, it is possible to stack a plurality of linear arrays of MR heads to form a sandwich structure, each layer of the sandwich structure comprising a linear array of MR heads, the adjacent layer being the other layer and at least one shield element. Sharing. By defining adjacent read channels in different layers, read channels that are less than 20 μm or less than 10 μm apart can be facilitated.

  The present invention can also be used in a system for reading and writing information to a magnetic medium utilizing an array of write heads arranged in a two-dimensional matrix and an array of MR heads arranged in a two-dimensional matrix. . In this case, each of the write heads is substantially aligned with a corresponding one of the read heads such that each of the write channels is substantially aligned with a corresponding read channel. Separate data signals can be written to tracks on the media using channels of the two-dimensional matrix array of write heads and can be read using respective channels of the two-dimensional matrix of MR heads.

  In one embodiment, the present invention provides a system for reading information stored on a magnetic medium. The system comprises a non-linear array of MR heads arranged in a two-dimensional matrix, each of the MR heads defining the read channel of the system.

  In another embodiment, the present invention provides a system for reading and writing information to magnetic media. The system comprises an array of write heads arranged in a two-dimensional matrix, each defining a write channel of the system, and an array of MR heads arranged in a two-dimensional matrix, each defining a read channel of the system.

  In another embodiment, the present invention provides a system for reading and writing information to magnetic tape. The system includes a first array of write heads, a first array of MR heads, a first actuator, a second array of write heads, a second array of MR heads, and a second actuator. Is provided. The first array of write heads is arranged in a two-dimensional matrix, and each of the write heads in the first array of write heads defines a system write channel in the first tape direction. The first array of MR heads is arranged in a two-dimensional matrix, and each of the MR heads in the first array of MR heads defines the read channel of the system in the second tape direction. The first actuator is coupled to the first array of write heads and the first array of MR heads to move the first array of write heads together with the first array of MR heads. The second array of write heads is arranged in a two-dimensional matrix, and each of the write heads in the second array of write heads defines a system write channel in the second tape direction. The second array of MR heads is arranged in a two-dimensional matrix, each of the MR heads defining a read channel of the system in the first tape direction. The second actuator is coupled to the second array of write heads and the second array of MR heads to move the second array of write heads together with the second array of MR heads.

  For example, a first array of write heads in the first tape direction can be used simultaneously with a second array of MR heads. Similarly, a second array of write heads may be used simultaneously with the first array of MR heads, for example in the second tape direction. Thus, the first and second actuators allow independent positioning of the write head array and the read head array regardless of tape movement. This also simplifies system fabrication by eliminating alignment problems between different arrays mounted on a common mounting structure. The actuators can be controlled independently by ensuring proper alignment and by feedback of servo positioning signals read by each respective array.

  The present invention can provide one or more advantages. For example, the present invention combines a planar array of MR heads and a planar array of write heads to facilitate a system that can operate at an improved track pitch as compared to conventional read / write systems. Specifically, track pitches of less than 100 μm, less than 50 μm, and even less than 10 μm can be achieved. Accordingly, the present invention can facilitate increasing the storage density on magnetic media and is particularly useful for increasing the storage density of magnetic tape. A planar array of MR heads formed by a plurality of linear arrays of MR heads stacked to define a plurality of layers, in terms of read quality and manufacturability compared to magneto-optical read heads or other read heads. May have advantages.

  In some embodiments, the present invention also provides systems and techniques that can perform bidirectional read / write operations on magnetic tape. Specifically, write operations can be performed simultaneously on a plurality of magnetic tape tracks having a track pitch of less than 100 μm, less than 50 μm, and even less than 10 μm. A read operation can be simultaneously performed on a plurality of magnetic tape tracks to verify the integrity of information written on the plurality of tape tracks, for example. Also, in some embodiments, the first and second actuators allow independent positioning of the array of write heads and the array of read heads regardless of tape movement. In this case, as described above, the alignment of the write head array and the read head can be independently performed by different actuators, so that the system can be improved.

  The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims.

  The present invention provides a system comprising a non-linear array of magnetoresistive (MR) heads arranged in a two-dimensional matrix. Each of the two-dimensional matrix MR heads defines the read channel of the system. The nonlinear array of MR heads can comprise a planar array formed by a plurality of linear arrays of MR heads stacked to define a plurality of layers of the nonlinear array. Each of the linear arrays of MR heads that define the layers of the nonlinear array may share at least one shield element with other linear arrays of the nonlinear array. In other words, it is possible to stack a plurality of linear arrays of MR heads to form a sandwich structure, each layer of the sandwich structure comprising a linear array of MR heads, the adjacent layer being the other layer and at least one shield element. Sharing. By defining adjacent read channels in different layers, read channels separated by less than 20 μm or less than 10 μm can be easily achieved.

  The present invention can also be used in a system for reading and writing information to a magnetic medium utilizing an array of write heads arranged in a two-dimensional matrix and an array of MR heads arranged in a two-dimensional matrix. . In this case, each of the write heads is substantially aligned with a corresponding one of the read heads such that each of the write channels is substantially aligned with the corresponding read channel. Separate data signals can be written to tracks on the media using channels of the two-dimensional matrix array of write heads and can be read using respective channels of the nonlinear array of MR heads. However, in some cases, the array of read heads may include additional read heads that are not necessarily aligned with a write head that may be used, for example, for servo tracking.

  As will be described in more detail below, the present invention includes features that can operate at an improved track pitch as compared to conventional read / write systems. Accordingly, the present invention can facilitate increasing the storage density on magnetic media and is particularly useful for increasing the storage density of magnetic tape. Specifically, track pitches of less than 20 μm and even less than 10 μm can be achieved. Furthermore, the present invention may have advantages in terms of quality and manufacturability compared to magneto-optical read heads or other read heads.

  Also, material misalignment between the magnetic tape and the read / write head can lead to misalignment between the track and the read / write head due to differences in thermal and hygroscopic expansion coefficients. A non-linear array of two-dimensional matrix MR heads addresses these issues by facilitating track pitch reduction. Track / head misalignment problems are reduced because dimensional changes to the media are averaged over a distance spanned by the head channel pitch number. Since the MR head channel pitch is greatly reduced in a two-dimensional matrix arrangement, the distance covered by the head channel is also reduced. As such, the system described herein can facilitate read and write operations with very small track pitches.

  FIG. 1 is a perspective view of a system 10 comprising a linear array 14 of magnetoresistive (MR) heads and a planar array 12 of write heads. In the figure, each magnetoresistive head is abbreviated as (MR), and each write head is abbreviated as (WH). Accurate mounting of the linear array 14 of MR heads and the planar array 12 of write heads within the mounting structure 16 ensures that the channels of the linear array 14 are aligned with the channels of the planar array. Channel alignment between arrays 12 and 14 may be ensured using, for example, a microscope or optical alignment technique. Alternatively, separate mounting structures or actuators may be used for the arrays 12 and 14. In this case, servo tracking can be performed independently for each array.

  As the magnetic tape 18 passes through the planar array 12 of write heads, data can be written to different tracks on the magnetic tape 18 by different write heads in the planar array 12. Each write head defines a channel of the planar array 12, and each channel corresponds to a unique track on the magnetic tape 18. Each MR head in the linear array 14 also defines a channel. Each channel defined by the write head and the corresponding MR head is aligned with a track on the magnetic tape 18. Thus, each track on the magnetic tape 18 can be written by a unique write head of the planar array 12 and read by a unique MR head of the linear array 14. One or more write heads of the planar array 12 may also function as inductive read elements used to read and track pre-written servo marks.

  The track of the magnetic tape 18 can be a data track or a servo track. Accordingly, data or servo information may be recorded using the channels of planar array 12 depending on the implementation of system 10. The linear array 14 of MR heads can simultaneously read information stored on different tracks of the magnetic tape 18. As the magnetic tape 18 passes through the linear array 14 of MR heads, data can be read from different tracks on the magnetic tape 18 by different MR heads of the linear array 14. Data or servo information can be read using the channels of the linear array 14 as well as the channels of the planar array 12. In some cases, for example, the linear array 14 can be used regardless of the planar array 12 when reading prerecorded data. In other cases, the linear array 14 can be used to read and verify the raw information recorded by the planar array 12.

  FIG. 2 is a bottom view of system 10 illustrating a planar array 12 of write heads and a linear array 14 of MR heads. Specifically, planar array 12 comprises a set of write heads 22 arranged in a two-dimensional matrix, each of the write heads defining a write channel of system 10. However, in other examples, the two-dimensional matrix of write heads may be non-planar.

  The linear array 14 comprises a set of magnetoresistive (MR) heads 24 arranged in a linear configuration. What is important is that each of the write heads 22 is substantially aligned with a corresponding one of the MR heads 24. As such, the system 10 may include the same number of write heads 22 and MR heads 24. Although sixteen MR heads 24 and sixteen write heads 22 are shown, system 10 may include any number of MR heads 24 and a corresponding number of write heads 22. Optionally, an additional read head can be provided for reading the servo positioning signal.

  Traditionally, the reduction in track pitch in magnetic tape systems has been limited by the difficulty in reducing the spacing between write heads in a linear array of write heads. Specifically, the pitch of the excitation coil of the write head usually leads to the track pitch limit in the conventional magnetic writing apparatus. To address such track pitch limitations, the present invention provides a planar array 12 of write heads 22 arranged in a two-dimensional matrix. Therefore, the channel pitch of adjacent write heads 22 is not limited by the pitch of the excitation coils. In some cases, the conventional track pitch limitation can be further eliminated by winding the excitation coil of the write head 22 in a direction perpendicular to the plane of the planar array 12. An array of write heads having excitation coils perpendicular to the plane of the array can also be formed in the integrated circuit. In either case, the planar array 12 is used with a linear array 14 of MR heads. For example, since the track pitch spacing problem is not common for a linear array of MR heads, the linear array 14 of MR heads may comprise a conventional configuration of MR heads.

  Another problem associated with track pitch reduction is due to dimensional instability of flexible magnetic media. Specifically, flexible magnetic media can pose a significant problem in track pitch reduction because changes in media dimensions can cause changes between track positions before and after the track is written. The matrix array of write heads described herein eliminates the limitations imposed by the head coil, and further includes these multiple head channels so that dimensional changes to the media are distributed across multiple tracks. Address the issue. As such, the system described herein can facilitate read and write operations with very small track pitches.

  Each of the write heads 22 is substantially aligned with a corresponding one of the MR heads 24. Thus, each channel of system 10 includes a unique one of write head 22 and a corresponding unique one of read head 24. Each channel corresponds to a track on a recording medium, such as a data track or a servo track on a magnetic tape. According to the present invention, the track pitch (and head channel pitch) can be less than 100 μm, less than 50 μm, and even less than 10 μm. This degree of channel pitch is generally achievable with a linear array of MR heads, but this degree of channel pitch is generally not achievable with a linear array of write heads including an excitation coil. In order to achieve such a channel pitch for the write head, a planar array is generally required. Thus, the present invention facilitates a read / write system that can operate at an improved track pitch compared to conventional read / write systems by combining a linear array of MR heads and a planar array of write heads.

  FIG. 3 is another bottom view of system 10 comprising a planar array 12 of write heads and a linear array 14 of read heads. In the illustration of FIG. 3, the planar array 12 comprises a set of write heads illustrated as write gaps arranged in a two-dimensional matrix. Each write head (or write gap) also defines a write channel of system 10. In FIG. 3, 16 channels are labeled.

  The linear array 14 comprises a set of magnetoresistive (MR) heads illustrated in FIG. 3 as gaps 27 arranged in a linear configuration. What is important is that each of the write heads 22 is substantially aligned with a corresponding one of the MR heads 24. As such, the system 10 may include the same number of write heads 22 and MR heads 24. Each channel can be considered to be defined by a corresponding head of the linear array 14, a corresponding head of the planar array 12, or both. However, as described above, in some cases, an additional read head can be provided for reading the servo positioning signal. In either case, the present invention combines a linear array 14 of MR heads and a planar array 12 of write heads to facilitate a system that can operate at an improved track pitch as compared to conventional read / write systems. Such a track pitch may be less than 100 μm, less than 50 μm, or even less than 10 μm. With such a track pitch, the data storage density of the magnetic medium can be increased particularly with respect to the magnetic tape.

  As an example, the planar array 12 of write heads may include an independently controlled fully integrated matrix magnetic recording head substantially as described in US Pat. No. 6,053,031 published on January 16, 2003 to Noziers et al. . Patent Document 1 is incorporated herein by reference in its entirety. However, other configurations of the planar array 12 can be used. Although the write head is illustrated in FIG. 3 as gaps 28 arranged in a planar matrix configuration, a non-planar matrix configuration can also be used.

  The linear array 14 of MR heads may comprise a set of MR heads or giant magnetoresistive (GMR) heads arranged in a linear configuration. Each MR head of the linear array 14 may include an MR sensor material that is responsive to a magnetic field. When the magnetic field in proximity to the MR sensor material changes, the MR head can detect such changes. Thus, MR heads facilitate the detection of magnetically encoded information on magnetic media using magnetic and resistance phenomena.

  A linear array of MR heads may have advantages in terms of read quality and manufacturability compared to magneto-optical read heads or other read heads. For this reason, the combination of a linear array of MR heads and a planar array of write heads enables read and write operations at an improved track pitch compared to conventional systems, and compared to systems using magneto-optical read heads for reading. It is also possible to provide a read / write system at a low cost. MR heads may also have better read sensitivity and improved signal-to-noise ratio compared to magneto-optical read heads or other types of read heads that can operate at the small track pitch described herein. Therefore, the MR head is more reliable than the magneto-optical head or other reading head.

  FIG. 4 is a block diagram of system 30 illustrating a portion of planar array 32 of write heads and a portion of linear array 34 of MR heads. In this case, only two channels of the planar array 32 and two corresponding channels of the linear array 34 are shown. For example, the first channel is defined by the first write head 33A and the first MR head 35A, and the second channel is defined by the second write head 33B and the second MR head 35B.

  Write heads 33A and 33B are substantially similar, but are separated by a distance of one head channel pitch (P). Specifically, the write gaps 49A and 49B of the write heads 33A and 33B are separated by a head channel pitch (P). The write head 33 will be described with reference to the head 33A. On the other hand, the write head 33B is substantially the same as the write head 33A.

  The write head 33A includes a magnetic circuit fabricated on a nonmagnetic substrate. The write head 33A includes an excitation coil 37 wound in a direction perpendicular to the plane defined by the planar array 32. This helps to reduce the size of the array and facilitates the matrix configuration within the integrated circuit.

  Specifically, the excitation coil 37 is wound around the bottom pole piece 40. The bottom pole piece 40, the two posts 41, 42 and the two magnetic flux concentrators 43, 44 are made of a magnetic material such as NiFe or other soft magnetic material. The magnetic flux concentrators 43 and 44 are divided to define a gap 45. Above the gap 45 are additional pole pieces 46, 47 made of a highly saturated magnetic material that can prevent harmful saturation of the pole when writing data. For example, the pole pieces 46, 47 may comprise sputtered FeTaN / TaN multilayers or plated FeCoNi, FeCoCr or NiFe. Pole pieces 46, 47 define a write gap 49A that is used to write magnetic signals to the magnetic medium. The head 33A can be formed by thin film deposition and patterning techniques generally known in the art. Further details of an exemplary write head 33 can be found in US Pat.

  The write head 33 can be controlled separately by the write controllers 51A and 51B. Therefore, a signal can be written to an adjacent track on the magnetic medium using the write head 33. What is important is that the illustrated configuration of the write head 33 allows for a head channel pitch that is less than 100 μm, less than 50 μm, and even less than 10 μm, and thus a track pitch. The write head 33 can also function as an inductive read element used to read and track pre-written servo marks.

  MR heads 35A and 35B may comprise any type of MR read head, including a giant magnetoresistive (GMR) head. MR heads 35A and 35B may be arranged in a linear configuration. MR heads 35A and 35B are substantially similar but are separated by a distance of one head channel pitch (P). The MR head 35 will be described with reference to the head 35A.

MR head 35A
It includes a magnetoresistive sensor material 55 separated by conductive materials 56 and 57. The magnetoresistive sensor material 55 may include NiFe or any other material that exhibits a property that the material resistance is responsive to a magnetic field. In other words, the resistance of the sensor material 55 varies as a function of the magnetic field proximate to the material 55. Therefore, it is possible to pass the track of the magnetic tape under the magnetoresistive sensor material 55, and the magnetic change in the track affects the resistance of the material 55. As an example, the conductive materials 56, 57 may comprise Au or any other suitable conductive material.

  Read controller 53A provides either a constant voltage or a constant current to conductive materials 56 and 57. Then, the read controller 53A recognizes the change in the resistance of the material 55 by measuring the change in voltage or current according to, for example, Ohm's law. Thus, the magnetic change recorded on the track of the magnetic tape can be detected by the MR head 35A.

  MR heads 35A and 35B can be controlled separately by read controllers 53A and 53B. Therefore, signals can be read from adjacent tracks on the magnetic medium using the MR head 35. In any case, the illustrated configuration of the MR head 35 or a modification thereof allows a head channel pitch that is less than 100 μm, less than 50 μm, or even less than 10 μm, and thus a track pitch. Thus, the MR head 35 can be used with a planar array of write heads 33 to define a read / write system that functions with an improved track pitch of less than 100 μm, less than 50 μm, and even less than 10 μm.

  FIG. 5 shows the plane of the write head disposed between the first linear array of MR heads 64A, the second linear array of MR heads 64B, and the first and second linear arrays of MR heads 64A and 64B. 1 is a perspective view of a system 60 comprising an array 62. FIG. Channel alignment between the arrays 62, 64A and 64B can be ensured by mounting and aligning the arrays 62, 64A and 64B within the mounting structure 61 using, for example, a microscope or other optical alignment technique. . Alternatively, separate mounting structures or actuators can be used for different arrays, and servo tracking can be performed independently for each array.

  As shown, the system 60 allows read / write operations to occur regardless of the movement of the magnetic tape. For example, if the tape moves from right to left, the channels of the planar array 62 can write data and the channels of the first linear array 64A can read and verify the data written by the channels of the planar array 62. .

  Alternatively, if the magnetic tape moves from left to right, the channels of the planar array 62 write data and the channels of the second linear array 64B read and verify the data written by the channels of the planar array 62. can do. Accordingly, the system 60 can perform writing and verification operations regardless of the tape movement direction with respect to the system 60.

  FIG. 6 is a bottom view of system 60 illustrating a planar array 62 of write heads and first and second linear arrays 64A and 64B of MR heads. Specifically, planar array 62 comprises a set of write heads 66 arranged in a two-dimensional matrix, each of which defines a write channel of system 60 regardless of the direction of tape movement. The first linear array 64A includes a set of MR heads 68 arranged in a linear configuration that defines a read channel as the tape moves in a first direction relative to the system 60. The second linear array 64B includes a set of MR heads 69 arranged in a linear configuration that defines a read channel as the tape moves in a second direction relative to the system 60. Thus, when the tape moves in the first direction (in this case from right to left), data is written using the planar array 62 and the data is read and verified using the first linear array 64A. When moving in the direction of 2 (in this case from left to right), the data is written using the planar array 62 and the data is read and verified using the second linear array 64B.

  Importantly, each of the write heads 66 is substantially aligned with a corresponding one of the MR heads 68 of the first linear array 64A and a corresponding one of the MR heads 69 of the second linear array 64B. is there. Thus, each of the arrays 62, 64A and 64B includes the same number of heads. Also shown are 16 MR heads 68, 16 MR heads 69, and 16 write heads 66, but system 60 may include any number of heads in each of the respective arrays. However, as described above, in some cases, an additional read head can be provided for reading the servo positioning signal.

  FIG. 7 illustrates the linearity of an MR head disposed between a first planar array 72A of write heads, a second planar array 72B of write heads, and first and second planar arrays 72A and 72B of write heads. 1 is a perspective view of a system 70 that includes an array 74. FIG. Channel alignment between arrays 72A, 72B, and 74 can be ensured by mounting and aligning arrays 72A, 72B, and 74 within mounting structure 71 using, for example, a microscope or other optical alignment technique. . Alternatively, separate mounting structures or actuators can be used for different arrays, and servo tracking can be performed independently for each array.

  Similar to system 60, system 70 of FIG. 7 allows read / write operations to occur regardless of magnetic tape movement. For example, when the tape moves from left to right, the channels of the first planar array 72A write data, and the channels of the linear array 74 read and verify the data written by the channels of the first planar array 72A. be able to.

  Alternatively, if the magnetic tape moves from right to left, the channel of the second planar array 72B writes data and the channel of the linear array 74 writes the data written by the channel of the second planar array 72B. Can be read and verified. Accordingly, the system 70 is another configuration capable of performing writing and verification operations regardless of the tape moving direction with respect to the system 70.

  FIG. 8 is a bottom view of system 70 illustrating a linear array 74 of MR heads and first and second planar arrays 72A and 72B of write heads. Specifically, the first planar array 72A comprises a set of write heads 76 arranged in a two-dimensional matrix, each of the write heads as the magnetic tape moves relative to the system 70 in the first tape direction. A write channel for system 70 is defined. The second planar array 72B comprises a set of write heads 77 arranged in another two-dimensional matrix, each of the writes of the system 70 as the magnetic tape moves in the second tape direction relative to the system 70. A write channel is defined.

  The linear array 74 comprises a set of MR heads 78 arranged in a linear configuration, and the channels of the linear array 74 perform read and verify operations as the magnetic tape moves in either the first or second tape direction. be able to. Thus, when the tape moves in the first direction (in this case from left to right), data is written using the first planar array 72A and read and verified using the linear array 74. When moving in the two directions (in this case, from right to left), data is written using the second planar array 72B, and the data is read using the linear array 74 and verified.

  Each of the write heads 76 of the first planar array 72A is substantially aligned with a corresponding one of the MR heads 78 of the linear array 74. Each of the write heads 77 of the second planar array 72B is also substantially aligned with a corresponding one of the MR heads 78 of the linear array 74. Thus, each of the arrays 72A, 72B and 74 includes the same number of write heads, but additional read heads may be provided for reading servo positioning signals. Also shown are 16 write heads 76, 16 write heads 77, and 16 MR heads 78, but system 70 may include any number of heads in each of the respective arrays.

  FIG. 9 is a flow diagram according to an embodiment of the present invention. As shown in FIG. 9, system 10 simultaneously writes information to a plurality of channels on a magnetic tape using a planar array 12 of write heads (91). The system 10 then reads information from multiple channels of the magnetic tape simultaneously using a linear array 14 of MR heads (92). In this way, the linear array 14 can serve as a verification mechanism that ensures the integrity of any data written by the planar array 12.

  In another example, the planar array 62 of the system 60 simultaneously writes information to multiple channels of magnetic tape regardless of the direction in which the tape is fed to the system. In this case, the first linear array 64A simultaneously reads information from a plurality of channels of the magnetic tape when the tape is fed in the first direction, and the second linear array 64B is read by the magnetic tape when the tape is fed in the second direction. Read information from multiple channels simultaneously. Thus, it is possible to perform a bidirectional read / write operation, the planar array 62 performs a write operation in both directions, the first linear array 64A performs a read or verify operation in the first tape direction, and the second array Linear array 64B performs a read or verify operation for the second tape direction.

  In another example, planar array 72A of system 70 writes information to multiple channels of the magnetic tape simultaneously when the tape is fed in a first direction, and planar array 72B is magnetic when the tape is fed in a second direction. Write information to multiple channels on the tape simultaneously. In this case, the linear array 74 reads information from multiple channels of the magnetic tape simultaneously, regardless of whether the tape is fed in the first or second direction. In this way, bidirectional read / write operations can be performed, planar arrays 72A and 72B perform write operations in different directions, and linear array 74 performs read or verify operations in both tape directions.

  FIG. 10 is a conceptual exploded perspective view illustrating a portion of a non-linear array 100 of MR heads arranged in a two-dimensional matrix to form a planar array. The MR head non-linear array 100 comprises three linear arrays 105-107 of MR heads stacked to define the layers of the non-linear array 100. Any number of linear arrays can be used in such a stacked configuration. Although the adjacent layer may have a shared shield, the present invention is not necessarily limited in this respect. The MR reader has a shield, while the write head has a magnetic pole.

  Each individual MR element of each of the linear arrays 105-107 is offset by at least one width 111, which corresponds to the length of the MR gap. Nonlinear array 100 includes shield elements 101-104, respectively, between each of linear arrays 105-107 of MR heads. In this example, each of the linear arrays 105-107 shares at least one shield element with the other one of the linear arrays 105-107. Nonlinear array 100 comprises a sandwich structure having any number of linear arrays separated by shield elements. In other words, although the non-linear array 100 is shown having three linear arrays 105-107 separated by corresponding shield elements 101-104, the invention is not so limited and is sandwiched between the shield elements. Can include any of a plurality of linear arrays. The non-linear array 100 can be fabricated using thin film deposition techniques and / or patterning techniques.

  Each of the linear arrays 105-107 includes a set of MR heads arranged in a linear configuration. The linear arrays 105-107 may comprise any type of MR head, including a giant magnetoresistive (GMR) head. Each MR head 108 of linear arrays 105-107 is substantially similar, but is separated by a distance of one head channel pitch 112 within the respective linear array. MR head 108 includes a magnetoresistive material 110 separated by a conductive material 109. The magnetoresistive material 110 may include NiFe or any other material that exhibits a property that the material resistance is responsive to a magnetic field. In other words, the resistance of the sensor material 110 varies as a function of the magnetic field in proximity to the material 110. Therefore, it is possible to pass the track of the magnetic tape under the magnetoresistive sensor material 110, and the magnetic change in the track affects the resistance of the material 110. As an example, the conductive material 109 can include Cu, Au, or any other suitable conductive material.

  Nonlinear array 100 may have advantages in terms of read quality and manufacturability compared to magneto-optical read heads or other read heads. Therefore, the non-linear array 100 enables a reading operation with an improved track pitch as compared with the conventional system, and can also provide a reading system at a lower cost than a system using a read magneto-optical head. MR heads may also have better read sensitivity and improved signal-to-noise ratio compared to magneto-optical read heads or other types of read heads that can operate at the small track pitch described herein. Accordingly, such an MR head is more reliable than a magneto-optical head or other read head.

  FIG. 11 is a conceptual bottom view of the nonlinear array 100 of MR heads shown in FIG. The linear arrays 105-107 of MR heads are stacked to form a sandwich structure. Each of the linear arrays 105-107 of MR heads comprises a sandwich layer, with adjacent layers sharing at least one of the shield elements 101-104 with the other layers. In accordance with the present invention, each element of linear arrays 105-107 is offset with respect to the elements of the linear array. In this manner, the head channel pitch 113 of the non-linear array 100 can be made significantly smaller than the channel pitch 112 of a given linear array. As shown in FIG. 11, the head channel pitch 113 can be defined such that portions of adjacent heads overlap. This overlap is possible because adjacent heads, i.e., continuous heads used to read adjacent tracks, are defined in different layers. However, in some cases it may be advantageous to define the spacing between adjacent tracks by defining an additional distance between adjacent heads. According to the present invention, the head channel pitch 113 (and hence the track pitch on the medium) can be made less than 20 μm or less than 10 μm.

  FIG. 12 is a perspective view of a system 110 comprising a planar array 114 of MR heads and a planar array 112 of write heads. As described above, the planar array 114 of MR heads comprises a linear array of MR heads that are stacked to define the layers of the planar array 114. Any number of linear arrays can be used in such a stacked configuration. Accurate mounting of the planar array 114 of MR heads and the planar array 112 of write heads within the mounting structure 116 ensures that the channels of the planar array 114 are aligned with the channels of the planar array 112. For example, a microscope or other optical alignment technique may be used to ensure channel alignment between the arrays 114 and 112. Alternatively, separate mounting structures (not shown in FIG. 12) can be used for array 114 and array 112 so that separate actuators can independently control different arrays. In this case, for example, servo tracking can be performed independently for each array.

  As the magnetic tape 118 passes through the planar array 112 of write heads, data can be written to different tracks on the magnetic tape 118 by different write heads in the planar array 112. Each write head defines a channel in planar array 112, with each channel corresponding to a unique track on magnetic tape 118. Each MR head in the planar array 114 also defines a channel. Each channel defined by the write head and the corresponding MR head is aligned with a track on the magnetic tape 118. In this way, each track on the magnetic tape 118 can be written by the unique write head of the planar array 112 and read by the unique MR head of the planar array 114. One or more write heads of the planar array 112 may also function as inductive read elements that are used to read and track pre-written servo marks.

  The track on the magnetic tape 118 can be a data track or a servo track. Thus, data or servo information may be recorded using the channels of planar array 112 depending on the implementation of system 110. The planar array 114 of MR heads can simultaneously read information stored on different tracks of the magnetic tape 118. As magnetic tape 118 passes through planar array 114 of MR heads, data can be read from different tracks on magnetic tape 118 by different MR heads in planar array 114. Similar to the channels of the planar array 112, the channels of the planar array 114 can be used to read data or servo information. In some cases, for example, the planar array 114 can be used independently of the planar array 112 when reading prerecorded data. In other cases, the planar array 114 may be used to read and verify the raw information recorded by the planar array 112.

  FIG. 13 is a bottom view of system 110 illustrating a planar array 112 of write heads and a planar array 114 of MR heads. Specifically, the planar array 112 comprises an array of write heads 122 arranged in a two-dimensional matrix, and the planar array 114 comprises an array of MR heads 124 arranged in a two-dimensional matrix. Each of the write heads in the planar array 112 defines a write channel for the system 110, and each of the MR heads in the planar array 114 defines a read channel for the system 110.

  The planar array 114 also includes a set of MR heads 124 arranged in a planar configuration compatible with the illustrations of FIGS. Importantly, each of the write heads 122 is substantially aligned with a corresponding one of the MR heads 124. As such, the system 110 may include the same number of write heads 122 and MR heads 124. Although sixteen MR heads 124 and sixteen write heads 122 are shown, system 110 may include any number of MR heads 124 and corresponding numbers of write heads 122. However, in some cases, an additional read head 122 for reading the servo positioning signal may be included. In other words, the read head array 114 may include additional read heads that are not necessarily aligned with the respective write heads, eg, used for servo tracking.

  The present invention can enable operation at an improved track pitch compared to conventional read / write systems. Accordingly, the present invention can facilitate increasing the storage density on magnetic media and is particularly useful for increasing the storage density of magnetic tape. Specifically, track pitches of less than 20 μm and even less than 10 μm can be achieved. Furthermore, the present invention may have advantages in terms of quality and manufacturability compared to magneto-optical read heads or other read heads.

  As described above, the reduction of the head channel pitch of a magnetic tape system has been limited by the difficulty in reducing the spacing between write heads in a conventional linear array of write heads. In other words, the head channel pitch of the magnetic tape system is conventionally limited by the write coil. Specifically, in the conventional magnetic writing apparatus, the pitch of the excitation coil of the write head usually leads to the limit of the track pitch. To address such pitch limitations, the present invention provides a planar array 112 of write heads 122 arranged in a two-dimensional matrix. Accordingly, the channel pitch of adjacent write heads 122 is not limited by the pitch of the excitation coils. In some cases, the conventional track pitch limitation can be further eliminated by winding the excitation coil of the write head 122 in a direction perpendicular to the plane of the planar array 112. An array of write heads having excitation coils perpendicular to the plane of the array can also be formed in the integrated circuit. In either case, planar array 112 is used with planar array 114 of MR heads. For example, when using a matrix type lighter, the pitch will be limited by the leader conductor spacing, so the planar array 114 of MR heads further improves the system.

  Another problem associated with track pitch reduction is due to material incompatibility between the magnetic tape and the read / write head. Material incompatibility can lead to misalignment between the track and the read / write head due to differences in thermal and hygroscopic expansion coefficients. The nonlinear arrangement of MR heads and write heads in each planar array can address these issues by facilitating channel pitch reduction. Because the dimensional changes to the media are averaged over multiple head channel pitches, the track / head misalignment problem is reduced, so a reduced head channel pitch leads to a corresponding reduction in misalignment. Since the MR head channel pitch is greatly reduced in a planar array arrangement of MR heads, the distance covered by the head channel is also reduced. As described above, each set of MR heads 124 arranged in a linear array to form a planar array 114 is offset with respect to the other set of MR heads 124. In this way, a portion of adjacent heads can overlap, for example because the conductors of adjacent heads are in different layers, so that the head channel pitch of planar array 114 can be significantly smaller than the channel pitch of a given linear array. As such, the system described herein can facilitate read and write operations with a very small head channel pitch, and thus a very small track pitch.

  Each of the write heads 122 is substantially aligned with a corresponding one of the MR heads 124. Thus, each channel of system 110 includes a unique one of write head 122 and a corresponding unique one of read head 124. Each channel corresponds to a track on a recording medium, such as a data track or a servo track on a magnetic tape. According to the present invention, the track pitch (and head channel pitch) can be made less than 20 μm, and further less than 10 μm. This degree of channel pitch is generally not achievable with a linear array of write heads including excitation coils. In order to achieve such a channel pitch for the write head, a planar array is generally required. The present invention also addresses any track pitch limitation of a linear array of MR heads by combining a planar array of MR heads with a planar array of write heads.

  FIG. 14 is another bottom view of system 110 comprising a planar array 112 of write heads and a planar array 114 of MR read heads. In the illustration of FIG. 14, the planar array 112 comprises an array of write heads illustrated as a two-dimensional matrix write gap, and the planar array 114 comprises an array of MR heads illustrated as gaps 127 arranged in a two-dimensional matrix. Each of the write heads (or write gaps) also defines a write channel for system 110, and each MR head of planar array 114 defines a read channel for system 110.

  Specifically, planar array 112 comprises a set of write heads 122 arranged in a two-dimensional matrix, and planar array 114 comprises a set of MR heads 124 arranged in a two-dimensional matrix. Each of the write heads in the planar array 112 defines a write channel for the system 110, and each of the MR heads in the planar array 114 defines a read channel for the system 110. Importantly, each of the write heads 122 is substantially aligned with a corresponding one of the MR heads 124. However, in some cases, the array of read heads may include additional read heads that are not necessarily aligned with the write heads used, for example, for servo tracking. In FIG. 14, 16 channels are labeled.

  Each channel can be considered as defined by a corresponding head of planar array 114, a corresponding head of planar array 112, or both. In any case, the present invention combines a planar array 114 of MR heads and a planar array 112 of write heads to facilitate a system that can operate at an improved track pitch as compared to conventional read / write systems. Such a track pitch may be less than 20 μm, or even less than 10 μm. With such a track pitch, the data storage density of the magnetic medium can be increased particularly with respect to the magnetic tape.

  As an example, the planar array 112 of write heads can include independently controlled fully integrated matrix magnetic recording heads as generally described in US Pat. However, other configurations of the planar array 112 may be used. Although the write head is illustrated in FIG. 14 as gaps 128 arranged in a planar matrix configuration, a non-planar matrix configuration can also be used.

  A planar array of MR heads may have advantages in terms of read quality and manufacturability compared to magneto-optical read heads or other read heads. For this reason, the combination of the planar array of MR heads and the planar array of write heads enables reading and writing operations at an improved track pitch compared to conventional systems, and compared with systems using magneto-optical read heads for reading. It is also possible to provide a read / write system at a low cost. MR heads may also have better read sensitivity and improved signal-to-noise ratio compared to magneto-optical read heads or other types of read heads that can operate at the small track pitch described herein. Therefore, the MR head is more reliable than the magneto-optical head or other reading head.

  FIG. 15 is a block diagram of system 130 illustrating a portion of planar array 132 of write heads and a portion of planar array 134 of MR heads. In this case, only two channels of the planar array 132 and two corresponding channels of the planar array 134 are shown. For example, the first channel is defined by the first write head 133A and the first MR head 135A, and the second channel is defined by the second write head 133B and the second MR head 135B.

  Write heads 133A and 133B are substantially similar, but are separated by a distance of one head channel pitch (P). Specifically, the write gaps 149A and 149B of the write heads 133A and 133B are separated by a head channel pitch (P). The write head 133 will be described with reference to the head 133A. On the other hand, the write head 133B is substantially the same as the write head 133A.

  The write head 133A includes a magnetic circuit fabricated on a nonmagnetic substrate. The write head 133A includes an excitation coil 137 wound in a direction perpendicular to the plane defined by the planar array 132. This helps to reduce the size of the array and facilitates the matrix configuration within the integrated circuit.

  Specifically, the excitation coil 137 is wound around the bottom pole piece 140. The bottom pole piece 140, the two posts 141, 142 and the two flux concentrators 143, 144 are made of a magnetic material such as NiFe or other soft magnetic material. The magnetic flux concentrators 143 and 144 are divided to define a gap 145. Above the gap 145 are additional pole pieces 146, 147 made of a highly saturated magnetic material that can prevent harmful saturation of the poles when writing data. For example, the pole pieces 146, 147 may comprise sputtered FeTaN / TaN multilayers or plated FeCoNi, FeCoCr, or NiFe. Pole pieces 146, 147 define a write gap 149A that is used to write magnetic signals to the magnetic medium. The head 133A can be formed by thin film deposition and patterning techniques generally known in the art. Further details of an exemplary write head 133 can be found in US Pat.

  The write head 133 can be controlled separately by write controllers 151A and 151B, which can comprise a common unit or module that controls both channels. Therefore, a signal can be written to an adjacent track on the magnetic medium using the write head 133. Importantly, the illustrated configuration of the write head 133 allows for head channel pitches that are less than 20 μm, and even less than 10 μm, and thus track pitches. The write head 133 can also function as an inductive read element used to read and track pre-written servo marks.

  MR heads 135A and 135B may comprise any type of MR read head, including a giant magnetoresistive (GMR) head. MR heads 135A and 135B are arranged in a non-linear configuration. MR heads 135A and 135B are substantially similar but are separated by a distance of one head channel pitch (P).

  Each MR head includes a magnetoresistive sensor material separated by a conductive material. The magnetoresistive sensor material may include NiFe or any other material that exhibits a property that the material resistance is responsive to a magnetic field. In other words, the resistance of the sensor material changes as a function of the magnetic field in close proximity to the material. Therefore, it is possible to pass the track of the magnetic tape under the magnetoresistive sensor material, and the magnetic change in the track affects the resistance of the material. As an example, the conductive material surrounding the magnetoresistive sensor material may include Au or any other suitable conductive material.

  Read controller 153A provides either a constant voltage or a constant current to the conductive material of MR heads 135A and 135B. Then, the reading controller 153A recognizes the change in resistance by measuring the change in voltage or current, for example, according to Ohm's law. Thus, the magnetic change recorded on the track of the magnetic tape can be detected by the MR heads 135A and 135B.

  MR heads 135A and 135B are separately controllable by read controllers 153A and 153B, which may comprise a common unit or module that controls both channels. In some cases, controllers 151A, 151B, 153A and 153B are all implemented in a common unit. In either case, signals can be read from adjacent tracks on the magnetic medium using the MR head 135. The illustrated configuration of the MR head 135 or a modification thereof allows a head channel pitch, and thus a track pitch, of less than 20 μm, and even less than 10 μm. Thus, a planar array of MR heads 135 can be used with a planar array of write heads 133 to define a read / write system that functions with very small track pitches.

  FIG. 16 shows a first array 162 of write heads, a first array 161 of MR heads, and a first actuator 166 coupled to the first array 162 of write heads and the first array 161 of MR heads. A second array of write heads 168; a second array of MR heads 167; and a second actuator 172 coupled to the second array of write heads 168 and the second array of MR heads 167; 1 is a block diagram of a system 160 comprising Specifically, each of the first array of write heads 162 and the first array of MR heads 161 are arranged in a two-dimensional matrix, and each of the write heads 165 and MR heads 164 is a first tape-oriented system 160, respectively. And a read channel of system 160 in the second tape direction. The first actuator 166 moves the first array 162 of write heads together with the first array 161 of MR heads in response to a signal received from the controller 173.

  A second array of write heads 168 and a second array of MR heads 167 are also arranged in a two-dimensional matrix, each of write head 171 and MR head 170 being a second tape-oriented system 160 write channel and first, respectively. The read channel of the system 160 in the tape direction is defined. The second actuator 172 moves the second array 168 of write heads together with the second array 167 of MR heads in response to a signal received from the controller 173. Arrays 161 and 162 are mounted in mounting structure 163 and arrays 167 and 168 are mounted in mounting structure 169. However, in this embodiment, separate actuators 166 and 172 allow independent control of different mounting structures 163 and 169 so alignment between arrays 161 and 162 or between arrays 167 and 168 is not a problem. . Thus, a write array of one mounting structure can be used with a read array on another mounting structure in a given tape orientation, allowing separate control of the array. The creation of the system 160 can be simplified by eliminating strict alignment within a given mounting structure.

  Each of the first and second arrays 161 and 167 of MR heads also includes a set of MR heads arranged in a configuration compatible with the illustrations of FIGS. The controller 173 communicates with the first and second actuators 166 and 172 by electrical signals such that the first array 162 of write heads is substantially aligned with the second array 167 of MR heads and the second of the write heads. The first and second actuators 166 and 172 are controlled so that the first array 168 is substantially aligned with the first array 161 of MR heads.

  As a result, the system 160 allows read / write operations to occur regardless of the movement of the magnetic tape. For example, if the tape moves from right to left, the channels of the first array 162 of write heads can be used simultaneously with the second array 167 of MR heads. In this way, the first array 162 of write heads writes data, and the channels of the second array 167 of MR heads read and verify the data written by the channels of the first array 162 of write heads. it can. Alternatively, if the magnetic tape moves from left to right, the second array of write heads 168 may be used simultaneously with the first array 161 of MR heads. As a result, the second array 168 of write heads can write data, and the channels of the first array 161 of MR heads can read and verify the data written by the channels of the second array 168 of write heads. . Accordingly, the system 160 can perform writing and verification operations regardless of the direction of tape movement with respect to the system 160. Separate actuators can also eliminate the need for precise alignment within a given mounting structure.

  FIG. 17 shows a first array of MR heads 181, a second array of MR heads 183, an array of write heads 185, a first array of MR heads 181, a second array of MR heads 183 and a write head. 1 is a block diagram of a system 180 comprising an actuator 188 coupled to an array 185 of FIG. In particular, the actuator may be coupled to a mounting structure 187 to which the arrays 181, 183 and 185 are mounted.

  The array of write heads 185 includes a set of write heads 186 arranged in a two-dimensional matrix, each of the write heads 186 defining a write channel of the system 180 regardless of the direction of tape movement. The first array of MR heads 181 includes a set of MR heads 182 arranged to define a read channel when the tape moves in a first direction relative to the system 180. The second array of MR heads 183 includes a set of MR heads 184 that define a read channel as the tape moves in a second direction relative to the system 180. Thus, when the tape moves in the first direction (in this case from right to left), the data is written using the write head array 185 and the data is read and verified using the first array 181 of MR heads. When the tape moves in the second direction (in this case from left to right), the data is written using the write head array 185 and the data is read and verified using the second array 183 of MR heads.

  By mounting and aligning the first array of MR heads 181, the second array of MR heads 183, and the array of write heads 185 in mounting structure 187 using, for example, a microscope or other optical alignment technique. The channel alignment between the write head array 185 and the MR head first and second arrays 181 and 183 can be ensured. Actuator 188 moves array 185 of write heads together with first and second arrays 181 and 183 of MR heads in response to signals received from controller 189.

  FIG. 18 shows a first array 191 of write heads, a second array 193 of write heads, an array 195 of MR heads, a first array 191 of write heads, a second array 193 of write heads and an MR head. 1 is a block diagram of a system 190 comprising an actuator 198 coupled to an array 195 of FIG. Specifically, the first array of write heads 191 comprises a set of write heads 192 arranged in a two-dimensional matrix, each of the write heads moving in the first tape direction relative to the system 190. Sometimes the write channel of system 190 is defined. The second array of write heads 193 comprises a set of write heads 194 arranged in another two-dimensional matrix, each of the write heads as the magnetic tape moves in the second tape direction relative to the system 190. The write channel of system 190 is defined.

  The MR head array 195 also includes a set of MR heads 196 arranged in a two-dimensional matrix configuration compatible with the illustrations of FIGS. 10 and 11, wherein the channels of the MR head array 195 have a first or second magnetic tape. Read and verify operations can be performed when moving in either of the tape directions. Thus, when the tape moves in the first direction (in this case from left to right), the data is written using the first array of write heads 191 and the data is read or verified using the array 195 of MR heads. When the tape moves in the second direction (in this case from right to left), the data is written using the second array of write heads 193 and the data is read or verified using the array 195 of MR heads.

  A first array of write heads 191, a second array of write heads 193, and an array of MR heads 195 are mounted and aligned within mounting structure 197 using, for example, a microscope or other optical alignment technique. This ensures channel alignment between the MR head array 195 and the write head first and second arrays 191 and 193. Actuator 198 moves MR head array 195 with write head first and second arrays 191 and 193 in response to a signal received from controller 199.

  FIG. 19 shows a first array 201 of MR heads, a first actuator 204 coupled to the first array 201 of MR heads, a second array 205 of MR heads, and a second array 205 of MR heads. FIG. 3 is a block diagram of a system 200 comprising a second actuator 208 coupled to a write head array 209, and a third actuator 212 coupled to the write head array 209. Specifically, the array of write heads 209 comprises a set of write heads 210 arranged in a two-dimensional matrix, each of the write heads 210 defining a write channel of the system 200 regardless of the direction of tape movement.

  The first array of MR heads 201, the second array of MR heads 205, and the array of write heads 209 can be attached to different mounting structures 203, 207, and 211, respectively. Separate actuators 204, 208, and 212 control the position of the head in the mounting structures 203, 207, and 211 under the direction of the controller 213. The first, second and third actuators 204, 208 and 212 are independent of the first array 201 of MR heads, the second array 205 of MR heads, and the array 209 of write heads regardless of the direction of tape movement. Enable positioning.

  The first array 201 of MR heads comprises a set of MR heads 202 arranged to define a read channel as the tape moves in a first direction relative to the system 200. The second array 205 of MR heads includes a set of MR heads 206 that define a read channel as the tape moves in a second direction relative to the system 200. Thus, when the tape moves in the first direction (in this case from right to left), data is written using the array of write heads 209 and read or verified using the first array of MR heads 201. When the tape moves in the second direction (in this case from left to right), it writes data using the array of write heads 209 and reads or verifies the data using the second array 205 of MR heads.

  FIG. 20 illustrates a first array of write heads 221, a first actuator 224 coupled to the first array of write heads 221, a second array of write heads 225, and a second array of write heads 225. FIG. 3 is a block diagram of a system 220 comprising a second actuator 228 coupled to the MR head array 229, an MR head array 229, and a third actuator 232 coupled to the MR head array 229. Controller 233 controls actuators 224, 228, and 232 in response to signals detected by arrays 221, 225, and 229, respectively, or in response to detection of servo marks by servo elements (not shown), as the case may be. In some cases, one or more heads of different arrays may be used for such servo detection. The first, second and third actuators 224, 228 and 232 are independent of the first array of write heads 221, the second array of write heads 225, and the array of MR heads 229 regardless of the direction of tape movement. Enable positioning. When the tape moves in the first direction (in this case from left to right), the data is written using the first array of write heads 221 and read or verified using the array of MR heads 229. When moving in the second direction (in this case from right to left), the data is written using the second array of write heads 225 and the data is read or verified using the array of MR heads 229. The first array of write heads 221, the second array of write heads 225, and the array of MR heads 229 are attached to different mounting structures 223, 227, and 231, respectively. The first array of write heads 221 comprises a set of write heads 222 arranged to define a write channel in one tape direction, while the second array of write heads has a write channel in the opposite tape direction. A set of write heads 226 arranged to define. The MR head array 229 comprises a set of MR heads 230 arranged to define a read channel in both tape directions.

  FIG. 21 is a flowchart according to an embodiment of the present invention. As shown in FIG. 20, system 110 (FIGS. 12-14) simultaneously writes information to a plurality of channels on a magnetic tape using a planar array 112 of write heads (240). System 110 then reads information from multiple channels of the magnetic tape simultaneously using a planar array 114 of MR heads (242). In this way, the planar array 114 can serve as a verification mechanism that ensures the integrity of any data written by the planar array 112. “Channels” defined on magnetic tape are also referred to as tracks. In general, the term “channel” refers to the various head channels of the system, or alternatively may refer to tracks formed on tape using different heads of the system.

  In another example, the system 160 (FIG. 16) writes information to multiple channels of magnetic tape simultaneously, regardless of the direction in which the tape is sent to the system 160. For example, if the tape moves from left to right, the first array 162 of system 160 write heads simultaneously writes information to multiple channels of the magnetic tape, and the second array 167 of MR heads writes the first array of write heads. Data written by the channels of one array 162 can be read and verified. Alternatively, if the magnetic tape moves from right to left, the second array 168 of write heads can be used simultaneously with the first array 161 of MR heads.

  In another example, the array of write heads 185 of the system 180 (FIG. 17) writes information to multiple channels of magnetic tape simultaneously, regardless of the direction in which the tape is fed to the system 180. In this case, when the tape is fed in the first direction (in this case, from right to left), the first array 181 of MR heads reads information from multiple channels of the magnetic tape simultaneously, and the tape is in the second direction (in this case left To the right), the second array 183 of MR heads simultaneously reads information from multiple channels of the magnetic tape. In this way, it is possible to perform bidirectional read / write operations, the write head array 185 performs a write operation in both directions, and the MR head first array 181 performs a read or verify operation in the first tape direction. And the second array 183 of MR heads performs a read or verify operation for the second tape direction.

  In another example, when the tape is fed in a first direction (left to right in this case), the first array 191 of write heads in system 190 (FIG. 18) simultaneously writes information to multiple channels of the magnetic tape, and the tape Is sent in the second direction (in this case from right to left), the second array 193 of write heads simultaneously writes information to multiple channels of the magnetic tape. The MR head array 195 reads information from multiple channels of the magnetic tape simultaneously, regardless of whether the tape is fed in the first or second direction.

  Various embodiments of the invention have been described. For example, a system has been described for reading information stored on a magnetic medium using a non-linear array of MR heads arranged in a two-dimensional matrix. Nevertheless, various modifications may be made without departing from the spirit and scope of the invention.

  Also, while many of the techniques have been described in the context of reading and writing data to a data track, similar techniques can be used to write or read servo marks in servo tracks. Also, while many aspects of the present invention have been described in the context of magnetic tape, other data storage media may be used with the read / write systems described herein. These techniques can be useful for horizontal magnetic media where the magnetic orientation of the individual domains is approximately parallel to the surface of the media, or for perpendicular magnetic media where the magnetic anisotropy is perpendicular to the plane of the media. These and other embodiments are within the scope of the claims.

1 is a perspective view of a system comprising a linear array of magnetoresistive (MR) heads and a planar array of write heads, according to an embodiment of the invention. FIG. FIG. 2 is a bottom view of the system illustrated in FIG. 1. FIG. 3 is another bottom view of the system illustrated in FIG. 1. 2 is a block diagram illustrating a portion of a planar array of write heads and a portion of a linear array of MR heads, in accordance with an embodiment of the present invention. FIG. A planar array of write heads disposed between a first linear array of MR heads, a second linear array of MR heads, and a first and second linear array of MR heads in accordance with an embodiment of the present invention. It is a perspective view of a system provided with. FIG. 6 is a bottom view of the system illustrated in FIG. 5. A linear array of MR heads disposed between a first planar array of write heads, a second planar array of write heads, and a first and second planar array of write heads according to embodiments of the invention. It is a perspective view of a system provided with. FIG. 8 is a bottom view of the system illustrated in FIG. 7. FIG. 4 is a flow diagram according to an embodiment of the present invention. 2 is a conceptual exploded perspective view of a portion of a non-linear array of MR heads in accordance with an embodiment of the present invention. FIG. FIG. 11 is a conceptual bottom view of a portion of the nonlinear array of MR heads illustrated in FIG. 10. 1 is a perspective view of a system comprising a planar array of MR heads and a planar array of write heads according to an embodiment of the present invention. FIG. FIG. 13 is a bottom view of the system illustrated in FIG. 12. FIG. 13 is another bottom view of the system illustrated in FIG. 12. 2 is a block diagram illustrating a portion of a planar array of write heads and a portion of a planar array of MR heads, in accordance with an embodiment of the present invention. FIG. According to an embodiment of the present invention, a first array of write heads, a first array of MR heads, a first actuator coupled to the first array of write and read heads, and a second of write heads 2 is a block diagram of a system including an array, a second array of MR heads, and a second actuator coupled to the second array of write and read heads. FIG. In accordance with an embodiment of the present invention, coupled to a first array of MR heads, a second array of MR heads, an array of write heads, first and second arrays of MR heads, and an array of write heads. FIG. 2 is a block diagram of a system including an actuator. In accordance with an embodiment of the present invention, coupled to a first array of write heads, a second array of write heads, an array of MR heads, first and second arrays of write heads, and an array of MR heads. FIG. 2 is a block diagram of a system including an actuator. According to an embodiment of the present invention, a first array of MR heads, a first actuator coupled to the first array of MR heads, a second array of MR heads, and a second array of MR heads FIG. 5 is a block diagram of a system that includes a second actuator coupled, an array of write heads, and a third actuator coupled to the array of write heads. In accordance with an embodiment of the present invention, a first array of write heads, a first actuator coupled to the first array of write heads, a second array of write heads, and a second array of write heads FIG. 5 is a block diagram of a system that includes a second actuator coupled, an array of MR heads, and a third actuator coupled to the array of MR heads. FIG. 4 is a flow diagram according to an embodiment of the present invention.

Explanation of symbols

10 system 12 planar array of write heads 14 linear array of magnetoresistive (MR) heads 16 mounting structure 18 magnetic tape 22 write head 24 MR head 27, 28 gap 30 system 32 planar array of write heads 33A first write head 33B first Write head 34 34 linear array of MR heads 35A first MR head 35B second MR head 37 excitation coil 40 bottom pole pieces 41, 42 struts 43, 44 flux concentrator 45 gap 46, 47 pole pieces 49A, 49B writing Gap 51A, 51B Write controller 53A, 53B Read controller 55 Magnetoresistive sensor material 56, 57 Conductive material 60 System 61 Mounting structure 62 Planar array of write heads 64A MR head first Linear array 64B second linear array of MR heads 66 write head 68, 69 MR head 70 system 71 mounting structure 72A first planar array of write heads 72B second planar array of write heads 74 linear array 76 of MR heads, 77 Write head 78 MR head 91 Step 92 Step 100 Non-linear array of MR heads 101, 102, 103, 104 Shield elements 105, 106, 107 Linear array of MR heads 108 MR head 109 Conductive material 110 Magnetoresistive material (sensor material) / System 111 width 112 channel pitch of a given linear array / planar array of write heads 113 head channel pitch 114 planar array of MR heads 116 mounting structure 118 magnetic tape 122 writing 124 MR head 127, 128 gap 130 system 132 planar array of write heads 133A first write head 133B second write head 134 planar array of MR heads 135A first MR head 135B second MR head 137 excitation coil 140 Bottom pole piece 141, 142 Post 143, 144 Magnetic flux concentrator 145 Gap 146, 147 Pole piece 149A, 149B Write gap 151A, 151B Write controller 153A, 153B Read controller 160 System 161 MR array first array 162 Write head First array 163 Mounting structure 164 MR head 165 Write head 166 First actuator 167 Second array of MR heads 168 Second array of write heads 169 Mounting structure 170 MR head 171 Write head 172 Second actuator 173 Controller 180 System 181 First array of MR heads 182 MR head 183 Second array of MR heads 184 MR head 185 Write Array of heads 186 write head 187 mounting structure 188 actuator 189 controller 190 system 191 first array of write heads 192 write head 193 second array of write heads 194 write head 195 array of MR heads 196 MR head 197 mounting structure 198 actuator 199 Controller 200 System 201 First array of MR heads 202 MR head 203 Mounting structure 204 First Actuator 205 Second array of MR heads 206 MR head 207 mounting structure 208 second actuator 209 array of write heads 210 write head 211 mounting structure 212 third actuator 213 controller 220 system 221 first array of write heads 222 write Head 223 mounting structure 224 first actuator 225 second array of write heads 226 write head 227 mounting structure 228 second actuator 229 MR head array 230 MR head 231 mounting structure 232 third actuator 233 controller 240 step 242 step

Claims (7)

A system for reading and writing information to a magnetic medium,
An array of write heads arranged in a two-dimensional matrix;
An array of magnetoresistive (MR) heads arranged in a two-dimensional matrix;
Each of the write heads defines a write channel of the system;
A system in which each of the MR heads defines a read channel of the system.   The system of claim 1, wherein the array of MR heads comprises a planar array of MR heads, and the array of write heads comprises a planar array of write heads.   The system of claim 1, wherein the write channels are separated by less than 10 μm and the read channels are separated by less than 10 μm.   The system of claim 1, wherein the MR head comprises a giant magnetoresistive (GMR) head.   The system of claim 1, wherein each of the write heads and each of the MR heads are independently controllable.   The system of claim 1, wherein each write head includes an excitation coil wound in a direction perpendicular to a plane defined by the array of write heads.   The system of claim 1, further comprising an actuator coupled to the array of write heads and the array of MR heads to move the array of write heads together with the array of MR heads.

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