Magnetic tape, magnetic tape cartridge, servo pattern writing device, magnetic tape drive, magnetic tape system, detection device, inspection device, servo pattern writing method, magnetic tape manufacturing method, detection method, and inspection method

Abstract

According to the present invention, a first servo pattern has a first position and a second position at which the first servo pattern crosses with a virtual line. A second servo pattern has a third position at which the second servo pattern crosses with the virtual line. The virtual line is set at a position at which the relationship in which the distance between the first and second positions is half the distance between the first position and the third position is held. The width of a servo band is set to the length that makes the distance from the virtual line to one end of the servo band in the width direction match the distance from the virtual line to the other end of the servo band in the width direction.

Description

Magnetic tape, magnetic tape cartridge, servo pattern recording device, magnetic tape drive, magnetic tape system, detection device, inspection device, servo pattern recording method, magnetic tape manufacturing method, detection method, and inspection method

[0001] The technology disclosed herein relates to a magnetic tape, a magnetic tape cartridge, a servo pattern recording device, a magnetic tape drive, a magnetic tape system, a detection device, an inspection device, a servo pattern recording method, a magnetic tape manufacturing method, a detection method, and an inspection method.

[0002] In U.S. Patent Application Publication No. 2021 / 0125633, the servo pattern on the magnetic tape is a conventional pattern, and width compensation is performed by tilting the head of the magnetic tape drive. The conventional pattern refers to a pattern in which two non-parallel patterns are arranged symmetrically with respect to an imaginary line in the width direction, and have the same azimuth angle but in opposite directions.

[0003] The servo pattern disclosed in U.S. Patent Application Publication No. 2021 / 0125633 causes non-uniformity in the servo signal. To solve this problem, the servo pattern disclosed in U.S. Patent Application Publication No. 2022 / 0108718 is formed in a rotated orientation from the conventional symmetrical servo pattern, thereby suppressing non-uniformity in the servo signal.

[0004] One embodiment of the technology disclosed herein provides a magnetic tape, a magnetic tape cartridge, a servo pattern recording device, a magnetic tape drive, a magnetic tape system, a detection device, an inspection device, a servo pattern recording method, a magnetic tape manufacturing method, a detection method, and an inspection method that can contribute to achieving high-precision reading of servo bands.

[0005] A first aspect of the technique of the present disclosure is a magnetic tape having a servo band, in which a plurality of servo patterns are recorded along the longitudinal direction of the magnetic tape, the servo pattern being at least one pair of linear magnetization regions, the pair of linear magnetization regions being a first linearly magnetized linear region and a second linearly magnetized linear region, the first linear magnetization region and the second linear magnetization region being inclined in opposite directions with respect to a first imaginary line along the width direction of the magnetic tape, the first linear magnetization region having a steeper inclination angle with respect to the first imaginary line than the second linear magnetization region, and the positions of both ends of the first linear magnetization region and the positions of both ends of the second linear magnetization region are aligned with each other in the width direction of the magnetic tape, the servo band having first servo patterns and second servo patterns alternately arranged along the longitudinal direction as the plurality of servo patterns, the plurality of servo patterns including a plurality of servo patterns. a first position where the virtual line intersects with a first linear magnetization region of the first servo pattern; a second position where the virtual line intersects with a second linear magnetization region of the first servo pattern; a third position where the virtual line intersects with a first linear magnetization region of the second servo pattern; the first position where the virtual line intersects with a first linear magnetization region of the first servo pattern; the second position where the virtual line intersects with a second linear magnetization region of the first servo pattern; the virtual lines are set at positions where a relationship is established between adjacent first and second servo patterns in the longitudinal direction such that a first distance between the first and second positions is half a second distance between the first and third positions; and the width of the servo band is set to a length such that the distance from the virtual line to one end of the servo band in the width direction is equal to the distance from the virtual line to the other end of the servo band in the width direction.

[0006] A second aspect of the technology disclosed herein is a magnetic tape according to the first aspect, in which the first linear magnetization region is a collection of multiple first magnetization lines, the second linear magnetization region is a collection of multiple second magnetization lines, the first position is a position where a first magnetization line located at one end of the longitudinal direction of the multiple first magnetization lines included in the first servo pattern on the virtual line intersects with the virtual line, the second position is a position where a second magnetization line located at one end of the longitudinal direction of the multiple second magnetization lines included in the first servo pattern on the virtual line intersects with the virtual line, and the third position is a position where a first magnetization line located at one end of the longitudinal direction of the multiple first magnetization lines included in the second servo pattern on the virtual line intersects with the virtual line.

[0007] A third aspect of the technology disclosed herein is a magnetic tape according to the second aspect, in which the number of first magnetization lines and the number of second magnetization lines in the servo pattern are the same, the number of first magnetization lines is different between the first servo pattern and the second servo pattern, and the number of second magnetization lines is different between the first servo pattern and the second servo pattern.

[0008] A fourth aspect of the technique of the present disclosure is the magnetic tape according to any one of the first to third aspects, in which a plurality of servo bands are formed at a predetermined pitch in the width direction.

[0009] A fifth aspect of the technology of the present disclosure is a magnetic tape cartridge comprising a magnetic tape according to any one of the first to fourth aspects and a case in which the magnetic tape is housed.

[0010] A sixth aspect of the technique of the present disclosure is a servo pattern recording device including a pulse signal generator and a servo pattern recording head, wherein the pulse signal generator generates a pulse signal, and the servo pattern recording head has a gap pattern, and records a plurality of servo patterns in a band-like region formed on a surface of a magnetic tape along the longitudinal direction of the magnetic tape by applying a magnetic field from the gap pattern in accordance with the pulse signal to the band-like region, and a servo band is formed by recording the plurality of servo patterns in the band-like region along the longitudinal direction, and the gap pattern is at least one pair of linear regions, and a first linear region that is one of the pair of linear regions and a second linear region that is the other of the pair of linear regions are inclined in opposite directions with respect to a second imaginary line that is aligned in a direction corresponding to the width direction of the magnetic tape on the surface, and the first linear region has a steeper inclination angle with respect to the second imaginary line than the second linear region, and both ends of the first linear region and the second linear region are aligned in a direction corresponding to the width direction of the magnetic tape, and the servo pattern is at least one pair of linear magnetization regions. The pair of linear magnetized regions is a linearly magnetized first linear magnetized region and a linearly magnetized second linear magnetized region, the first linear magnetized region and the second linear magnetized region are inclined in opposite directions with respect to a first imaginary line along the width direction of the magnetic tape, the first linear magnetized region has a steeper inclination angle with respect to the first imaginary line than the second linear magnetized region, and the positions of both ends of the first linear magnetized region and the positions of both ends of the second linear magnetized region are aligned with each other in the width direction of the magnetic tape, and the servo band has first servo patterns and second servo patterns arranged in a longitudinal direction as a plurality of servo patterns. and the servo patterns are alternately arranged along a line, and a virtual line that crosses the servo patterns along the longitudinal direction is set in the plurality of servo patterns, the first servo pattern has a first position and a second position where the virtual line intersects, the second servo pattern has a third position where the virtual line intersects, the first position is a position where the virtual line intersects with the first linear magnetization region of the first servo pattern, the second position is a position where the virtual line intersects with the second linear magnetization region of the first servo pattern, and the third position is a position where the virtual line intersects with the first linear magnetization region of the second servo pattern, and the virtual line isA servo pattern recording device in which a first servo pattern and a second servo pattern adjacent to each other in the longitudinal direction are set at positions where a relationship is established in which a first distance, which is the distance between a first position and a second position, is half of a second distance, which is the distance between the first position and a third position, and the width of a servo band is set to a length such that the distance from an imaginary line to one end of the servo band in the width direction is equal to the distance from the imaginary line to the other end of the servo band in the width direction.

[0011] A seventh aspect of the technology disclosed herein is a servo pattern recording device according to the sixth aspect, in which the first linear magnetization region is a collection of a plurality of first magnetization lines, the second linear magnetization region is a collection of a plurality of second magnetization lines, the first position is a position where a first magnetization line located at one end in the longitudinal direction of the plurality of first magnetization lines included in the first servo pattern on the virtual line intersects with the virtual line, the second position is a position where a second magnetization line located at one end in the longitudinal direction of the plurality of second magnetization lines included in the first servo pattern on the virtual line intersects with the virtual line, and the third position is a position where a first magnetization line located at one end in the longitudinal direction of the plurality of first magnetization lines included in the second servo pattern on the virtual line intersects with the virtual line.

[0012] An eighth aspect of the technology disclosed herein is a servo pattern recording device according to the seventh aspect, in which the number of first magnetization lines and the number of second magnetization lines in the servo pattern are the same, the number of first magnetization lines is different between the first servo pattern and the second servo pattern, and the number of second magnetization lines is different between the first servo pattern and the second servo pattern.

[0013] A ninth aspect of the technique of the present disclosure is a servo pattern recording device according to any one of the sixth to eighth aspects, in which a plurality of servo bands are formed at a predetermined pitch in the width direction.

[0014] A tenth aspect of the technology of the present disclosure is a magnetic tape drive comprising: a running mechanism that runs a magnetic tape according to any one of the first to fourth aspects along a predetermined path; and a magnetic head having a plurality of servo read elements that read a servo pattern on the predetermined path while the magnetic tape is running by the running mechanism, wherein the plurality of servo read elements are arranged along the longitudinal direction of the magnetic head, and the magnetic head is positioned in an attitude in which the longitudinal direction of the magnetic head is inclined with respect to the running direction of the magnetic tape.

[0015] An eleventh aspect of the technology of the present disclosure is a magnetic tape system comprising a magnetic tape according to any one of the first to fourth aspects, and a magnetic tape drive equipped with a magnetic head having a plurality of servo read elements that read servo patterns on a predetermined path while the magnetic tape is running along the predetermined path, wherein the plurality of servo read elements are arranged along the longitudinal direction of the magnetic head, and the magnetic head is positioned in an attitude in which the longitudinal direction of the magnetic head is inclined with respect to the running direction of the magnetic tape.

[0016] A twelfth aspect of the technology of the present disclosure is a detection device including a processor, wherein the processor detects a servo signal resulting from a servo pattern being read by a servo read element from a magnetic tape according to any one of the first to fourth aspects using an autocorrelation coefficient.

[0017] A thirteenth aspect of the technique of the present disclosure includes generating a pulse signal, and recording a plurality of servo patterns in a band-like region formed on the surface of a magnetic tape along the longitudinal direction of the magnetic tape by applying a magnetic field from the gap pattern in accordance with the pulse signal to the band-like region using a servo pattern recording head having a gap pattern, the servo pattern being recorded in the longitudinal direction of the band-like region, whereby a servo band is formed by recording the plurality of servo patterns in the band-like region along the longitudinal direction, the gap pattern being at least one pair of straight line regions, a first straight line region which is one of the pair of straight line regions and a second straight line region which is the other of the pair of straight line regions being inclined in opposite directions with respect to a second imaginary line which is in a direction corresponding to the width direction of the magnetic tape on the surface, the first straight line region having a steeper inclination angle with respect to the second imaginary line than the second straight line region, and the positions of both ends of the first straight line region and the positions of both ends of the second straight line region being aligned in a direction corresponding to the width direction of the magnetic tape, the servo pattern being at least one pair of linear magnetized regions, the pair of linear magnetized regions being linearly magnetized The magnetic tape has a first linear magnetization region and a second linear magnetization region that is linearly magnetized, the first linear magnetization region and the second linear magnetization region are inclined in opposite directions with respect to a first imaginary line along the width direction of the magnetic tape, the first linear magnetization region has a steeper inclination angle with respect to the first imaginary line than the second linear magnetization region, and the positions of both ends of the first linear magnetization region and the positions of both ends of the second linear magnetization region are aligned with each other in the width direction of the magnetic tape, and the servo band has a plurality of servo patterns, first servo patterns and second servo patterns, alternately arranged along the longitudinal direction. The plurality of servo patterns are provided with imaginary lines that cross the plurality of servo patterns along the longitudinal direction, the first servo pattern has a first position and a second position where the imaginary lines intersect, the second servo pattern has a third position where the imaginary lines intersect, the first position is a position where the imaginary lines intersect with the first linear magnetization region of the first servo pattern, the second position is a position where the imaginary lines intersect with the second linear magnetization region of the first servo pattern, the third position is a position where the imaginary lines intersect with the first linear magnetization region of the second servo pattern, and the imaginary lines areA servo pattern recording method in which a first servo pattern and a second servo pattern adjacent to each other in the longitudinal direction are set at positions where a relationship is established in which a first distance, which is the distance between a first position and a second position, is half of a second distance, which is the distance between the first position and a third position, and the width of the servo band is set to a length such that the distance from the imaginary line to one end of the servo band in the width direction is equal to the distance from the imaginary line to the other end of the servo band in the width direction.

[0018] A fourteenth aspect of the technique of the present disclosure is a magnetic tape on which a plurality of servo patterns are recorded by the servo pattern recording device according to any one of the sixth to ninth aspects.

[0019] A fifteenth aspect of the technique of the present disclosure is a magnetic tape cartridge including the magnetic tape according to the fourteenth aspect and a case in which the magnetic tape is housed.

[0020] A sixteenth aspect of the technology of the present disclosure is a magnetic tape drive comprising a running mechanism that runs the magnetic tape of the fourteenth aspect along a predetermined path, and a magnetic head having a plurality of servo read elements that read servo patterns on the predetermined path while the magnetic tape is run by the running mechanism, wherein the plurality of servo read elements are arranged along the longitudinal direction of the magnetic head, and the magnetic head is positioned in an attitude in which the longitudinal direction of the magnetic head is inclined with respect to the running direction of the magnetic tape.

[0021] A seventeenth aspect of the technology of the present disclosure is a magnetic tape system comprising a magnetic tape according to the fourteenth aspect and a magnetic tape drive equipped with a magnetic head having a plurality of servo read elements that read servo patterns on a predetermined path while the magnetic tape is running along the predetermined path, wherein the plurality of servo read elements are arranged along the longitudinal direction of the magnetic head, and the magnetic head is positioned in an attitude in which the longitudinal direction of the magnetic head is inclined with respect to the running direction of the magnetic tape.

[0022] An eighteenth aspect of the disclosed technology is a detection device including a processor, wherein the processor detects a servo signal resulting from a servo pattern being read by a servo read element from the magnetic tape according to the fourteenth aspect using an autocorrelation coefficient.

[0023] A nineteenth aspect of the disclosed technique is a method for manufacturing a magnetic tape, including recording a plurality of servo patterns on a magnetic tape according to the servo pattern recording method of the thirteenth aspect, and winding up the magnetic tape.

[0024] A twentieth aspect of the technique of the present disclosure is an inspection device comprising a detection device according to the twelfth or eighteenth aspect, and an inspection processor that inspects a servo band on a magnetic tape in which a servo pattern is recorded, based on a servo signal detected by the detection device.

[0025] A 21st aspect of the technology of the present disclosure is a detection method that includes detecting a servo signal, which is the result of a servo pattern being read by a servo read element from a magnetic tape according to any one of the first to fourth and fourteenth aspects, using an autocorrelation coefficient.

[0026] A 22nd aspect of the technology of the present disclosure is an inspection method that includes inspecting a servo band on a magnetic tape in which a servo pattern is recorded, based on a servo signal detected by the detection method of the 21st aspect.

[0027] 1 is a block diagram showing an example of the configuration of a magnetic tape system according to an embodiment. FIG. 2 is a schematic perspective view showing an example of the appearance of a magnetic tape cartridge according to an embodiment. FIG. 3 is a schematic configuration diagram showing an example of the hardware configuration of a magnetic tape drive according to an embodiment. FIG. 4 is a schematic perspective view showing an example of a mode in which a magnetic field is emitted by a non-contact read / write device from the underside of a magnetic tape cartridge according to an embodiment. FIG. 5 is a schematic configuration diagram showing an example of the hardware configuration of a magnetic tape drive according to an embodiment. FIG. 6 is a conceptual diagram showing an example of a mode in which a magnetic head is positioned on a conventionally known magnetic tape, observed from the surface side of the magnetic tape. FIG. 7 is a conceptual diagram showing an example of a mode in which a magnetic head is skewed on a conventionally known magnetic tape, observed from the surface side of the magnetic tape. FIG. 8 is a conceptual diagram showing an example of a mode in which a magnetic tape according to an embodiment is observed from the surface side of the magnetic tape. FIG. 9 is a conceptual diagram showing an example of a relationship between the geometric characteristics of an actual servo pattern and the geometric characteristics of a virtual servo pattern. FIG. 10 is a conceptual diagram showing an example of the configuration of servo bands formed on a magnetic tape according to an embodiment. FIG. 11 is a conceptual diagram showing an example of a mode in which corresponding frames between adjacent servo bands in the width direction of the magnetic tape according to an embodiment are shifted by a predetermined interval, observed from the surface side of the magnetic tape. FIG. 1 is a conceptual diagram showing an example of a state in which a servo pattern is read by a servo read element included in a magnetic head that is not skewed on a magnetic tape according to an embodiment, observed from the surface side of the magnetic tape. FIG. 1 is a conceptual diagram showing an example of a state in which a servo pattern is read by a servo read element included in a magnetic head that is skewed on a magnetic tape according to an embodiment, observed from the surface side of the magnetic tape. FIG. 2 is a conceptual diagram showing an example of a function of a control device included in a magnetic tape drive according to an embodiment. FIG. 3 is a conceptual diagram showing an example of processing contents of a position detection unit and a control unit included in a control device included in a magnetic tape drive according to an embodiment. FIG. 4 is a conceptual diagram showing an example of a configuration of a servo writer according to an embodiment.1 is a conceptual diagram showing an example of the relationship between a pulse signal generator and a servo pattern recording head included in the servo writer according to the embodiment, and an example of a state in which the servo pattern recording head included in the servo writer according to the embodiment is positioned above a magnetic tape, observed from the surface side of the magnetic tape (i.e., the back side of the servo pattern recording head). 2 is a conceptual diagram showing an example of a state in which the servo pattern recording head included in the servo writer according to the embodiment is positioned above a magnetic tape, observed from the surface side of the magnetic tape (i.e., the back side of the servo pattern recording head). 3 is a conceptual diagram showing an example of the relationship between the geometric characteristics of an actual gap pattern and the geometric characteristics of a virtual gap pattern.

[0028] Below, examples of embodiments of the magnetic tape, magnetic tape cartridge, servo pattern recording device, magnetic tape drive, magnetic tape system, detection device, inspection device, servo pattern recording method, magnetic tape manufacturing method, detection method, and inspection method relating to the technology disclosed herein will be described with reference to the attached drawings.

[0029] First, the terms used in the following description will be explained.

[0030] CPU is an abbreviation for "Central Processing Unit". RAM is an abbreviation for "Random Access Memory". NVM is an abbreviation for "Non-volatile memory". EEPROM is an abbreviation for "Electrically Erasable and Programmable Read Only Memory". SSD is an abbreviation for "Solid State Drive". HDD is an abbreviation for "Hard Disk Drive". ASIC is an abbreviation for "Application Specific Integrated Circuit". FPGA is an abbreviation for "Field-Programmable Gate Array". PLC is an abbreviation for "Programmable Logic Controller". IC is an abbreviation for "Integrated Circuit". RFID is an abbreviation for "Radio Frequency Identifier". BOT is an abbreviation for "Beginning Of Tape". EOT is an abbreviation for "End Of Tape". UI is an abbreviation for "User Interface." WAN is an abbreviation for "Wide Area Network." LAN is an abbreviation for "Local Area Network." TDS is an abbreviation for "Transverse Dimensional Stability."

[0031] 1, as an example, a magnetic tape system 10 includes a magnetic tape cartridge 12 and a magnetic tape drive 14. The magnetic tape cartridge 12 is loaded into the magnetic tape drive 14. The magnetic tape cartridge 12 contains a magnetic tape MT. The magnetic tape drive 14 pulls out the magnetic tape MT from the loaded magnetic tape cartridge 12 and, while running the pulled-out magnetic tape MT, records data on the magnetic tape MT and reads data from the magnetic tape MT.

[0032] In this embodiment, the magnetic tape MT is an example of a "magnetic tape" according to the technology of the present disclosure. Also, in this embodiment, the magnetic tape system 10 is an example of a "magnetic tape system" according to the technology of the present disclosure. Also, in this embodiment, the magnetic tape drive 14 is an example of a "magnetic tape drive" and a "detection device" according to the technology of the present disclosure. Also, in this embodiment, the magnetic tape cartridge 12 is an example of a "magnetic tape cartridge" according to the technology of the present disclosure.

[0033] Next, an example of the configuration of the magnetic tape cartridge 12 will be described with reference to Figures 2 to 4. For convenience of explanation, in the following description, the loading direction of the magnetic tape cartridge 12 into the magnetic tape drive 14 is indicated by arrow A in Figures 2 to 4, the direction of arrow A is the front direction of the magnetic tape cartridge 12, and the front side of the magnetic tape cartridge 12 is the front side of the magnetic tape cartridge 12. In the following description of the structure, "front" refers to the front side of the magnetic tape cartridge 12.

[0034] 2 to 4, for convenience of explanation, the direction of arrow B, which is orthogonal to the direction of arrow A, is defined as the right direction, and the right side of the magnetic tape cartridge 12 is defined as the right side of the magnetic tape cartridge 12. In the following description of the structure, "right" refers to the right side of the magnetic tape cartridge 12.

[0035] 2 to 4, for convenience of explanation, the direction opposite to the direction of arrow B is referred to as the left direction, and the left side of the magnetic tape cartridge 12 is referred to as the left side of the magnetic tape cartridge 12. In the following description of the structure, "left" refers to the left side of the magnetic tape cartridge 12.

[0036] 2 to 4, for convenience of explanation, the direction perpendicular to the directions of arrows A and B is indicated by arrow C, the direction of arrow C is the upward direction of the magnetic tape cartridge 12, and the upward side of the magnetic tape cartridge 12 is the upper side of the magnetic tape cartridge 12. In the explanation of the structure shown below, "upper" refers to the upper side of the magnetic tape cartridge 12.

[0037] 2 to 4, for convenience of explanation, the direction opposite to the front direction of the magnetic tape cartridge 12 is referred to as the rear direction of the magnetic tape cartridge 12, and the rear side of the magnetic tape cartridge 12 is referred to as the rear side of the magnetic tape cartridge 12. In the following description of the structure, "rear" refers to the rear side of the magnetic tape cartridge 12.

[0038] 2 to 4, for convenience of explanation, the direction opposite to the upper direction of the magnetic tape cartridge 12 is referred to as the lower direction of the magnetic tape cartridge 12, and the lower side of the magnetic tape cartridge 12 is referred to as the lower side of the magnetic tape cartridge 12. In the following description of the structure, "lower" refers to the lower side of the magnetic tape cartridge 12.

[0039] As shown in FIG. 2 as an example, the magnetic tape cartridge 12 has a box-shaped case 16 that is generally rectangular in plan view. The case 16 is an example of a "case" according to the technology of the present disclosure. The magnetic tape MT is housed in the case 16. The case 16 is made of a resin such as polycarbonate and has an upper case 18 and a lower case 20. The upper case 18 and the lower case 20 are joined by welding (e.g., ultrasonic welding) and screw fastening, with the lower peripheral surface of the upper case 18 and the upper peripheral surface of the lower case 20 in contact with each other. The joining method is not limited to welding and screw fastening, and other joining methods may also be used.

[0040] The supply reel 22 is rotatably housed inside the case 16. The supply reel 22 includes a reel hub 22A, an upper flange 22B1, and a lower flange 22B2. The reel hub 22A is cylindrical. The reel hub 22A is the axial center of the supply reel 22, and its axial direction is aligned with the vertical direction of the case 16, and it is disposed in the center of the case 16. The upper flange 22B1 and the lower flange 22B2 are each formed in an annular shape. The center of the upper flange 22B1 in a plan view is fixed to the upper end of the reel hub 22A, and the center of the lower flange 22B2 in a plan view is fixed to the lower end of the reel hub 22A. The reel hub 22A and the lower flange 22B2 may be integrally molded.

[0041] The magnetic tape MT is wound around the outer peripheral surface of the reel hub 22A, and the widthwise ends of the magnetic tape MT are held by an upper flange 22B1 and a lower flange 22B2.

[0042] An opening 16B is formed in the front side of the right wall 16A of the case 16. The magnetic tape MT is pulled out through the opening 16B.

[0043] The lower case 20 is provided with a cartridge memory 24. Specifically, the cartridge memory 24 is housed in the right rear end portion of the lower case 20. An IC chip having an NVM is mounted on the cartridge memory 24. In this embodiment, a so-called passive RFID tag is used as the cartridge memory 24, and various information is read and written to the cartridge memory 24 in a contactless manner.

[0044] The cartridge memory 24 stores management information for managing the magnetic tape cartridge 12. The management information includes, for example, information about the cartridge memory 24 (e.g., information that can identify the magnetic tape cartridge 12), information about the magnetic tape MT (e.g., information indicating the recording capacity of the magnetic tape MT, information indicating an overview of the data recorded on the magnetic tape MT, information indicating the items of data recorded on the magnetic tape MT, information indicating the recording format of the data recorded on the magnetic tape MT, etc.), and information about the magnetic tape drive 14 (e.g., information indicating the specifications of the magnetic tape drive 14 and signals used in the magnetic tape drive 14).

[0045] 3, the magnetic tape drive 14 includes a transport device 26, a magnetic head 28, a control device 30, storage 32, a UI device 34, and a communication interface 35. The magnetic tape cartridge 12 is loaded into the magnetic tape drive 14 in the direction of arrow A. In the magnetic tape drive 14, the magnetic tape MT is pulled out from the magnetic tape cartridge 12 and used.

[0046] The magnetic tape MT includes a magnetic layer 29A, a base film 29B, and a backcoat layer 29C. The magnetic layer 29A is formed on one side of the base film 29B, and the backcoat layer 29C is formed on the other side of the base film 29B. Data is recorded in the magnetic layer 29A. The magnetic layer 29A contains ferromagnetic powder. Examples of the ferromagnetic powder include ferromagnetic powders commonly used in the magnetic layers of various magnetic recording media. A preferred example of the ferromagnetic powder is hexagonal ferrite powder. Examples of the hexagonal ferrite powder include hexagonal strontium ferrite powder and hexagonal barium ferrite powder. The backcoat layer 29C is a layer containing a non-magnetic powder such as carbon black. The base film 29B, also referred to as a support, is formed of, for example, polyethylene terephthalate, polyethylene naphthalate, or polyamide. A non-magnetic layer may be formed between the base film 29B and the magnetic layer 29A. In the magnetic tape MT, the surface on which the magnetic layer 29A is formed is the front surface 31 of the magnetic tape MT, and the surface on which the backcoat layer 29C is formed is the back surface 33 of the magnetic tape MT.

[0047] The magnetic tape drive 14 performs magnetic processing on the surface 31 of the magnetic tape MT using the magnetic head 28. Here, magnetic processing refers to recording data on the surface 31 of the magnetic tape MT and reading data from the surface 31 of the magnetic tape MT (i.e., reproducing data). In this embodiment, the magnetic tape drive 14 selectively records data on the surface 31 of the magnetic tape MT and reads data from the surface 31 of the magnetic tape MT using the magnetic head 28. That is, the magnetic tape drive 14 pulls out the magnetic tape MT from the magnetic tape cartridge 12 and uses the magnetic head 28 to record data on the surface 31 of the pulled-out magnetic tape MT or reads data from the surface 31 of the pulled-out magnetic tape MT using the magnetic head 28.

[0048] The control device 30 controls the entire magnetic tape drive 14. In this embodiment, the control device 30 is realized by an ASIC, but the technology of the present disclosure is not limited to this. For example, the control device 30 may be realized by an FPGA and / or a PLC. The control device 30 may also be realized by a computer including a CPU, flash memory (e.g., EEPROM and / or SSD), and RAM. The control device 30 may also be realized by a combination of two or more of an ASIC, FPGA, PLC, and computer. In other words, the control device 30 may be realized by a combination of hardware and software. In this embodiment, the control device 30 is an example of a "processor" according to the technology of the present disclosure.

[0049] The storage 32 is connected to the control device 30, and the control device 30 writes various types of information to the storage 32 and reads various types of information from the storage 32. Examples of the storage 32 include a flash memory and / or a HDD. The flash memory and the HDD are merely examples, and any non-volatile memory that can be mounted in the magnetic tape drive 14 may be used.

[0050] The UI device 34 is a device having a reception function for receiving instruction signals indicating instructions from a user and a presentation function for presenting information to the user. The reception function is realized by, for example, a touch panel, hard keys (e.g., a keyboard), and / or a mouse. The presentation function is realized by, for example, a display, a printer, and / or a speaker. The UI device 34 is connected to the control device 30. The control device 30 acquires the instruction signals received by the UI device 34. The UI device 34 presents various information to the user under the control of the control device 30.

[0051] The communication interface 35 is connected to the control device 30. The communication interface 35 is also connected to an external device 37 via a communication network (not shown) such as a WAN and / or LAN. The communication interface 35 controls the exchange of various information (e.g., data to be recorded on the magnetic tape MT, data read from the magnetic tape MT, and / or instruction signals given to the control device 30) between the control device 30 and the external device 37. The external device 37 may be, for example, a personal computer or a mainframe.

[0052] The transport device 26 is a device that selectively transports the magnetic tape MT in the forward direction or the reverse direction along a predetermined path, and includes a feed motor 36, a take-up reel 38, a take-up motor 40, and multiple guide rollers GR. Note that the forward direction here refers to the feed direction of the magnetic tape MT, and the reverse direction refers to the rewind direction of the magnetic tape MT. In this embodiment, the transport device 26 is an example of a "travel mechanism" according to the technology of the present disclosure.

[0053] The supply motor 36 rotates the supply reel 22 in the magnetic tape cartridge 12 under the control of the control device 30. The control device 30 controls the supply motor 36 to control the rotation direction, rotation speed, rotation torque, etc. of the supply reel 22.

[0054] The take-up motor 40 rotates the take-up reel 38 under the control of the control device 30. The control device 30 controls the take-up motor 40 to control the rotation direction, rotation speed, rotation torque, etc. of the take-up reel 38.

[0055] When the magnetic tape MT is wound by the take-up reel 38, the control device 30 rotates the supply motor 36 and the take-up motor 40 so that the magnetic tape MT runs in the forward direction along a predetermined path. The rotational speed, rotational torque, etc. of the supply motor 36 and the take-up motor 40 are adjusted according to the speed at which the magnetic tape MT is wound around the take-up reel 38. Furthermore, tension is applied to the magnetic tape MT by the control device 30 adjusting the rotational speed, rotational torque, etc. of the supply motor 36 and the take-up motor 40. Furthermore, the tension applied to the magnetic tape MT is controlled by the control device 30 adjusting the rotational speed, rotational torque, etc. of the supply motor 36 and the take-up motor 40.

[0056] When the magnetic tape MT is rewound onto the supply reel 22, the control device 30 rotates the supply motor 36 and the take-up motor 40 so that the magnetic tape MT runs in the reverse direction along the predetermined path.

[0057] In this embodiment, the tension applied to the magnetic tape MT is controlled by controlling the rotation speed and rotation torque of the supply motor 36 and the take-up motor 40, but the technology of the present disclosure is not limited to this. For example, the tension applied to the magnetic tape MT may be controlled using a dancer roller, or may be controlled by drawing the magnetic tape MT into a vacuum chamber.

[0058] Each of the plurality of guide rollers GR is a roller that guides the magnetic tape MT. The predetermined path, i.e., the running path of the magnetic tape MT, is determined by disposing the plurality of guide rollers GR at positions across the magnetic head 28 between the magnetic tape cartridge 12 and the take-up reel 38.

[0059] The magnetic head 28 includes a magnetic element unit 42 and a holder 44. The magnetic element unit 42 is held by the holder 44 so as to come into contact with the running magnetic tape MT. The magnetic element unit 42 has a plurality of magnetic elements.

[0060] The magnetic element unit 42 records data on the magnetic tape MT transported by the transport device 26, and reads data from the magnetic tape MT transported by the transport device 26. Here, data refers to, for example, the servo patterns 58 (see FIG. 9) and data other than the servo patterns 58, i.e., data recorded in the data band DB (see FIG. 9).

[0061] The magnetic tape drive 14 is equipped with a non-contact read / write device 46. The non-contact read / write device 46 is disposed below the magnetic tape cartridge 12 when the magnetic tape cartridge 12 is loaded so as to directly face the back surface 24A of the cartridge memory 24, and reads and writes information from and to the cartridge memory 24 in a non-contact manner.

[0062] 4, the non-contact read / write device 46 emits a magnetic field MF from the bottom side of the magnetic tape cartridge 12 toward the cartridge memory 24. The magnetic field MF penetrates the cartridge memory 24.

[0063] The non-contact read / write device 46 is connected to the control device 30. The control device 30 outputs a control signal to the non-contact read / write device 46. The control signal is a signal that controls the cartridge memory 24. The non-contact read / write device 46 generates a magnetic field MF in accordance with the control signal input from the control device 30, and emits the generated magnetic field MF toward the cartridge memory 24.

[0064] The non-contact type read / write device 46 performs contactless communication with the cartridge memory 24 via the magnetic field MF, and performs processing on the cartridge memory 24 in accordance with the control signal. For example, under the control of the control device 30, the non-contact type read / write device 46 selectively performs processing to read information from the cartridge memory 24 and processing to store information in the cartridge memory 24 (i.e., processing to write information to the cartridge memory 24).

[0065] 5, the magnetic tape drive 14 includes a movement mechanism 48. The movement mechanism 48 has a movement actuator 48A. Examples of the movement actuator 48A include a voice coil motor and / or a piezoelectric actuator. The movement actuator 48A is connected to the control device 30, which controls the movement actuator 48A. The movement actuator 48A generates power under the control of the control device 30. The movement mechanism 48 receives the power generated by the movement actuator 48A to move the magnetic head 28 in the width direction of the magnetic tape MT.

[0066] The magnetic tape drive 14 is equipped with a tilt mechanism 49. The tilt mechanism 49 has a tilt actuator 49A. Examples of the tilt actuator 49A include a voice coil motor and / or a piezoelectric actuator. The tilt actuator 49A is connected to the control device 30, which controls the tilt actuator 49A. The tilt actuator 49A generates power under the control of the control device 30. By receiving the power generated by the tilt actuator 49A, the tilt mechanism 49 tilts the magnetic head 28 toward the longitudinal direction LD of the magnetic tape MT with respect to the width direction WD of the magnetic tape MT (see FIG. 8 ). In other words, the magnetic head 28 is skewed on the magnetic tape MT under the control of the control device 30.

[0067] As a comparative example for the magnetic tape MT, a case where a conventionally known magnetic tape MT0 is used instead of the magnetic tape MT will now be described with reference to Figures 6 to 8. Note that when comparing the magnetic tape MT0 with the magnetic tape MT, the difference is that the magnetic tape MT0 has a servo pattern 52 (see Figure 6) applied thereto, whereas the magnetic tape MT has a servo pattern 58 (see Figure 9) applied thereto.

[0068] 6, servo bands SB1, SB2, and SB3 and data bands DB1 and DB2 are formed on the surface 31 of the magnetic tape MT0. For ease of explanation, hereinafter, unless there is a need to distinguish between them, the servo bands SB1 to SB3 will be referred to as servo bands SB, and the data bands DB1 and DB2 will be referred to as data bands DB.

[0069] The servo bands SB1 to SB3 and the data bands DB1 and DB2 are formed along the longitudinal direction LD (i.e., the overall length direction) of the magnetic tape MT0. Here, the longitudinal direction LD refers to the running direction of the magnetic tape MT0. The running direction of the magnetic tape MT0 is defined as two directions: a forward direction (hereinafter also simply referred to as the "forward direction") in which the magnetic tape MT0 runs from the supply reel 22 side to the take-up reel 38 side, and a reverse direction (hereinafter also simply referred to as the "reverse direction") in which the magnetic tape MT0 runs from the take-up reel 38 side to the supply reel 22 side.

[0070] The servo bands SB1 to SB3 are arranged at positions spaced apart in the width direction WD of the magnetic tape MT0 (hereinafter also simply referred to as the "width direction WD"). For example, the servo bands SB1 to SB3 are formed at equal intervals along the width direction WD. Here, equal intervals are an example of a "predetermined pitch" according to the technology of the present disclosure. Note that in this embodiment, "equal intervals" refers to equal intervals that include, in addition to completely equal intervals, an error that is generally acceptable in the technical field to which the technology of the present disclosure belongs and that does not contradict the spirit of the technology of the present disclosure.

[0071] The data band DB1 is arranged between the servo bands SB1 and SB2, and the data band DB2 is arranged between the servo bands SB2 and SB3. In other words, the servo bands SB and the data bands DB are arranged alternately along the width direction WD.

[0072] In the example shown in Figure 6, for the sake of convenience, three servo bands SB and two data bands DB are shown, but this is merely an example, and the technology disclosed herein can be applied to two servo bands SB and one data band DB, or even to four or more servo bands SB and three or more data bands DB.

[0073] A plurality of servo patterns 52 are recorded on the servo band SB along the longitudinal direction LD of the magnetic tape MT0. The servo patterns 52 are classified into servo patterns 52A and servo patterns 52B. The plurality of servo patterns 52 are arranged at regular intervals along the longitudinal direction LD of the magnetic tape MT0. Note that in this embodiment, "constant" refers not only to perfect uniformity, but also to uniformity that includes an error that is generally acceptable in the technical field to which the technology of the present disclosure pertains and that does not contradict the spirit of the technology of the present disclosure.

[0074] The servo band SB is separated by a plurality of frames 50 along the longitudinal direction LD of the magnetic tape MT0. Each frame 50 is defined by a set of servo patterns 52. In the example shown in Fig. 6, servo patterns 52A and 52B are shown as an example of a set of servo patterns 52. The servo patterns 52A and 52B are adjacent to each other along the longitudinal direction LD of the magnetic tape MT0, and within the frame 50, the servo pattern 52A is located on the upstream side in the forward direction, and the servo pattern 52B is located on the downstream side in the forward direction.

[0075] The servo pattern 52 is made up of linear magnetization region pairs 54. The linear magnetization region pairs 54 are classified into linear magnetization region pairs 54A and linear magnetization region pairs 54B.

[0076] The servo pattern 52A is made up of a pair of linear magnetization regions 54A. In the example shown in Fig. 6, linear magnetization regions 54A1 and 54A2 are shown as an example of the pair of linear magnetization regions 54A. Each of the linear magnetization regions 54A1 and 54A2 is a linearly magnetized region.

[0077] The linear magnetization regions 54A1 and 54A2 are inclined in opposite directions with respect to a virtual line C1, which is a virtual line along the width direction WD. In the example shown in FIG. 6, the linear magnetization regions 54A1 and 54A2 are inclined in line symmetry with respect to the virtual line C1. More specifically, the linear magnetization regions 54A1 and 54A2 are formed non-parallel to each other and inclined at a predetermined angle (e.g., 5 degrees) in opposite directions on the longitudinal direction LD side of the magnetic tape MT0 with the virtual line C1 as the axis of symmetry. In this embodiment, the virtual line C1 is an example of a "first virtual line" and a "second virtual line" according to the technology of the present disclosure.

[0078] The linear magnetization region 54A1 is a set of five magnetized straight lines 54A1a, and the linear magnetization region 54A2 is a set of five magnetized straight lines 54A2a.

[0079] The servo pattern 52B is made up of a pair of linear magnetization regions 54B. In the example shown in Fig. 6, linear magnetization regions 54B1 and 54B2 are shown as an example of the pair of linear magnetization regions 54B. Each of the linear magnetization regions 54B1 and 54B2 is a linearly magnetized region.

[0080] The linear magnetization regions 54B1 and 54B2 are inclined in opposite directions with respect to a virtual line C2, which is a virtual line along the width direction WD. In the example shown in Figure 6, the linear magnetization regions 54B1 and 54B2 are inclined in line symmetry with respect to the virtual line C2. More specifically, the linear magnetization regions 54B1 and 54B2 are formed non-parallel to each other and inclined at a predetermined angle (e.g., 5 degrees) in opposite directions on the longitudinal direction LD side of the magnetic tape MT0 with the virtual line C2 as the axis of symmetry. In this embodiment, the virtual line C2 is an example of a "first virtual line" according to the technology of the present disclosure.

[0081] The linear magnetization region 54B1 is a set of four magnetized straight lines 54B1a, and the linear magnetization region 54B2 is a set of four magnetized straight lines 54B2a.

[0082] The magnetic head 28 is located on the surface 31 side of the magnetic tape MT0 configured in this manner. The holder 44 is formed in a rectangular parallelepiped shape and is arranged to cross the surface 31 of the magnetic tape MT0 in the width direction WD. The multiple magnetic elements of the magnetic element unit 42 are arranged linearly along the longitudinal direction of the holder 44. The magnetic element unit 42 has, as its multiple magnetic elements, a pair of servo read elements SR and multiple data read / write elements DRW. The longitudinal length of the holder 44 is sufficiently long relative to the width of the magnetic tape MT0. For example, the longitudinal length of the holder 44 is set to be longer than the width of the magnetic tape MT0 regardless of where the magnetic element unit 42 is arranged on the magnetic tape MT0.

[0083] The pair of servo read elements SR consists of servo read elements SR1 and SR2. The servo read element SR1 is disposed at one end of the magnetic element unit 42, and the servo read element SR2 is disposed at the other end of the magnetic element unit 42. In the example shown in Figure 6, the servo read element SR1 is provided at a position corresponding to the servo band SB2, and the servo read element SR2 is provided at a position corresponding to the servo band SB3.

[0084] The plurality of data read / write elements DRW are arranged linearly between the servo read element SR1 and the servo read element SR2. The plurality of data read / write elements DRW are arranged at intervals along the longitudinal direction of the magnetic head 28 (for example, at equal intervals along the longitudinal direction of the magnetic head 28). In the example shown in FIG. 6, the plurality of data read / write elements DRW are provided at positions corresponding to the data band DB2.

[0085] The control device 30 acquires a servo signal resulting from the servo read element SR reading the servo pattern 52, and performs servo control in accordance with the acquired servo signal. Here, servo control refers to control that moves the magnetic head 28 in the width direction WD of the magnetic tape MT0 by operating the movement mechanism 48 in accordance with the servo pattern 52 read by the servo read element SR.

[0086] By performing servo control, the plurality of data read / write elements DRW are positioned on a designated area in the data band DB, and perform magnetic processing on the designated area in the data band DB. In the example shown in Fig. 6, the plurality of data read / write elements DRW perform magnetic processing on the designated area in the data band DB2.

[0087] Furthermore, when the data band DB from which the magnetic element unit 42 reads data is changed (in the example shown in FIG. 6 , when the data band DB from which the magnetic element unit 42 reads data is changed from data band DB2 to data band DB1), the movement mechanism 48, under the control of the control device 30, moves the magnetic head 28 in the width direction WD to change the positions of the pair of servo read elements SR. That is, by moving the magnetic head 28 in the width direction WD, the movement mechanism 48 moves the servo read element SR1 to a position corresponding to servo band SB1 and moves the servo read element SR2 to a position corresponding to servo band SB2. As a result, the positions of the multiple data read / write elements DRW are changed from on data band DB2 to on data band DB1, and the multiple data read / write elements DRW perform magnetic processing on data band DB1.

[0088] Recently, research into techniques for reducing the effects of TDS has been progressing. TDS is influenced by factors such as temperature, humidity, the pressure at which the magnetic tape is wound around the reel, and deterioration over time, and it is known that if no countermeasures are taken, TDS will increase, resulting in off-track (i.e., misalignment of the data read / write element DRW with respect to the track in the data band DB) when magnetic processing is performed on the data band DB.

[0089] The example shown in Figure 7 shows a state in which the width of the magnetic tape MT0 shrinks over time. In this case, off-track occurs. The width of the magnetic tape MT0 may also expand, and in this case, off-track occurs. That is, when the width of the magnetic tape MT0 shrinks or expands over time, the position of the servo read element SR relative to the servo pattern 52 deviates in the width direction WD from the predetermined position determined by design (e.g., the center position of each of the linear magnetized regions 54A1, 54A2, 54B1, and 54B2). When the position of the servo read element SR relative to the servo pattern 52 deviates in the width direction WD from the predetermined position determined by design, the accuracy of servo control decreases, and the track in the data band DB and the position of the data read / write element DRW become misaligned. As a result, magnetic processing is no longer performed on the originally intended track.

[0090] As an example of a method for reducing the effects of TDS, a method is known in which the magnetic head 28 is skewed on the magnetic tape MT0, as shown in Figure 8, to maintain the position of the servo read element SR relative to the servo pattern 52 at a predetermined position determined by design.

[0091] The magnetic head 28 has a rotation axis RA. The rotation axis RA is located at a position corresponding to the center of the magnetic element unit 42 included in the magnetic head 28 in a planar view. The magnetic head 28 is rotatably held by a tilting mechanism 49 via the rotation axis RA. A virtual line C3, which is a virtual center line, is provided on the magnetic head 28. The virtual line C3 passes through the rotation axis RA and extends in the longitudinal direction of the magnetic head 28 in a planar view (i.e., the direction in which multiple data read / write elements DRW are arranged). The magnetic head 28 is held by the tilting mechanism 49 so that the virtual line C3 is tilted toward the longitudinal direction LD of the magnetic tape MT0 with respect to a virtual line C4, which is a virtual line along the width direction WD. In the example shown in FIG. 8 , the magnetic head 28 is held by the tilting mechanism 49 in a position in which the virtual line C3 is tilted toward the supply reel 22 with respect to the virtual line C4 (i.e., a position inclined counterclockwise when viewed from the front side of the paper surface of FIG. 8 ).

[0092] The tilt mechanism 49 receives power from a tilt actuator 49A (see FIG. 5 ) to rotate the magnetic head 28 about the rotation axis RA on the surface 31 of the magnetic tape MT0. Under the control of the control device 30, the tilt mechanism 49 rotates the magnetic head 28 about the rotation axis RA on the surface 31 of the magnetic tape MT0, thereby changing the direction and angle of tilt (i.e., azimuth) of the imaginary line C3 with respect to the imaginary line C4.

[0093] The direction and angle of inclination of the imaginary line C3 relative to the imaginary line C4 are changed according to temperature, humidity, the pressure at which the magnetic tape MT0 is wound around the reel, deterioration over time, etc., or the expansion and contraction in the width direction WD of the magnetic tape MT due to these, thereby maintaining the position of the servo read element SR relative to the servo pattern 52 at a predetermined position determined by design.

[0094] The servo read element SR is formed linearly along the virtual straight line C3. Therefore, when the servo read element SR reads the servo pattern 52A, the angle formed by the linear magnetized region 54A1 and the servo read element SR is different from the angle formed by the linear magnetized region 54A2 and the servo read element SR in the linear magnetized region pair 54A. This difference in angle causes variations (e.g., variations in signal level and waveform distortion) due to azimuth loss between the servo signal derived from the linear magnetized region 54A1 (i.e., the servo signal obtained by reading the linear magnetized region 54A1 with the servo read element SR) and the servo signal derived from the linear magnetized region 54A2 (i.e., the servo signal obtained by reading the linear magnetized region 54A2 with the servo read element SR). 8, the angle formed by the servo read element SR and the linear magnetized region 54A1 is larger than the angle formed by the servo read element SR and the linear magnetized region 54A2, resulting in a smaller servo signal output and a wider waveform, which causes variations in the servo signal read by the servo read element SR across the servo band SB while the magnetic tape MT0 is running. Furthermore, when the servo read element SR reads the servo pattern 52B, variations due to azimuth loss occur between the servo signal derived from the linear magnetized region 54B1 and the servo signal derived from the linear magnetized region 54B2. Such variations in the servo signal can be a factor in reducing the accuracy of servo control.

[0095] Another example of a conventionally known servo pattern 52A is one in which the linear magnetized region 54A1 is parallel to the virtual line C1 and the linear magnetized region 54A2 is inclined relative to the virtual line C1 (i.e., only the linear magnetized region 54A2 is inclined). Even in this conventionally known configuration, when the servo pattern 52A is read by the servo read element SR, the angle formed between the linear magnetized region 54A1 and the servo read element SR differs from the angle formed between the linear magnetized region 54A2 and the servo read element SR in the linear magnetized region pair 54A. Such angle differences result in variations due to azimuth loss between the servo signals derived from the linear magnetized region 54A1 and the servo signals derived from the linear magnetized region 54A2. Such variations in the servo signals can be a factor in reducing the accuracy of servo control.

[0096] In view of these circumstances, the present embodiment employs a magnetic tape MT as an example, as shown in Figure 9. The magnetic tape MT differs from the magnetic tape MT0 in that it has frames 56 instead of frames 50. The frames 56 are defined by a set of servo patterns 58. In the following, the same components of the magnetic tape MT as those of the magnetic tape MT0 will be assigned the same reference numerals and their description will be omitted.

[0097] The servo band SB is formed by recording a plurality of servo patterns 58 along the longitudinal direction LD in a strip-shaped area 61 formed on the magnetic tape MT in the longitudinal direction LD. The plurality of servo patterns 58 are arranged at regular intervals along the longitudinal direction LD of the magnetic tape MT, similar to the plurality of servo patterns 52 recorded on the magnetic tape MT0. In this embodiment, the strip-shaped area 61 is an example of a "strip-shaped area" according to the technology of the present disclosure.

[0098] One end of each of the plurality of servo patterns 58 in the width direction WD is aligned in the width direction WD, and the other end of each of the plurality of servo patterns 58 in the width direction WD is also aligned in the width direction WD. The length of the width SWD of the servo band SB is defined by the length of the width direction WD of the plurality of servo patterns 58 recorded along the longitudinal direction LD. That is, one end of each of the plurality of servo patterns 58 recorded along the longitudinal direction LD in the width direction WD defines one end E1 of the width SWD of the servo band SB, and the other end of each of the plurality of servo patterns 58 recorded along the longitudinal direction LD in the width direction WD defines the other end E2 of the width SWD of the servo band SB.

[0099] 9, servo patterns 58A and 58B are shown as an example of a set of servo patterns 58 included in a frame 56. The servo patterns 58A and 58B are adjacent to each other along the longitudinal direction LD of the magnetic tape MT, with the servo pattern 58A located upstream in the forward direction within the frame 56 and the servo pattern 58B located downstream in the forward direction. That is, in the servo band SB, the servo patterns 58A and 58B are alternately arranged along the longitudinal direction LD.

[0100] The servo pattern 58 is made up of linear magnetization region pairs 60. The linear magnetization region pairs 60 are classified into linear magnetization region pairs 60A and linear magnetization region pairs 60B. In this embodiment, the linear magnetization region pairs 60 are an example of the "linear magnetization region pairs" according to the technology of the present disclosure.

[0101] The servo pattern 58A is made up of a pair of linear magnetization regions 60A. In the example shown in Fig. 9, linear magnetization regions 60A1 and 60A2 are shown as an example of the pair of linear magnetization regions 60A. Each of the linear magnetization regions 60A1 and 60A2 is a linearly magnetized region.

[0102] In this embodiment, the linear magnetization region 60A1 is an example of a "first linear magnetization region" according to the technology of the present disclosure, and the linear magnetization region 60A2 is an example of a "second linear magnetization region" according to the technology of the present disclosure.

[0103] The linear magnetization regions 60A1 and 60A2 are tilted in opposite directions with respect to the imaginary line C1. In other words, the linear magnetization region 60A1 is tilted in one direction with respect to the imaginary line C1 (for example, the clockwise direction as viewed from the front side of the paper in FIG. 9 ). On the other hand, the linear magnetization region 60A2 is tilted in the other direction with respect to the imaginary line C1 (for example, the counterclockwise direction as viewed from the front side of the paper in FIG. 9 ).

[0104] The linear magnetization regions 60A1 and 60A2 are non-parallel to each other and inclined at different angles with respect to the virtual line C1. The linear magnetization region 60A1 has a steeper inclination angle with respect to the virtual line C1 than the linear magnetization region 60A2. Here, "steep" means, for example, that the angle of the linear magnetization region 60A1 with respect to the virtual line C1 is smaller than the angle of the linear magnetization region 60A2 with respect to the virtual line C1. Furthermore, the total length of the linear magnetization region 60A1 is shorter than the total length of the linear magnetization region 60A2.

[0105] In the servo pattern 58A, the linear magnetization region 60A1 is a collection of multiple magnetization lines 60A1a, and the linear magnetization region 60A2 is a collection of multiple magnetization lines 60A2a. Here, the magnetization lines 60A1a are an example of a "first magnetization line" according to the technology of the present disclosure, and the magnetization lines 60A2a are an example of a "second magnetization line" according to the technology of the present disclosure.

[0106] The number of magnetization lines 60A1a included in the linear magnetization region 60A1 is the same as the number of magnetization lines 60A2a included in the linear magnetization region 60A2. The linear magnetization region 60A1 is a collection of five magnetized lines 60A1a, and the linear magnetization region 60A2 is a collection of five magnetized lines 60A2a.

[0107] Within the servo band SB, the positions of both ends of the linear magnetization region 60A1 (i.e., the positions of both ends of each of the five magnetization lines 60A1a) and the positions of both ends of the linear magnetization region 60A2 (i.e., the positions of both ends of each of the five magnetization lines 60A2a) are aligned in the width direction WD.

[0108] Here, an example is given in which the positions of both ends of each of the five magnetization lines 60A1a and the positions of both ends of each of the five magnetization lines 60A2a are aligned, but this is merely one example, and it is sufficient that the positions of both ends of one or more of the five magnetization lines 60A1a and the positions of both ends of one or more of the five magnetization lines 60A2a are aligned.

[0109] In addition, in this embodiment, the concept of "aligned" not only means being completely aligned, but also includes the meaning of "aligned" including an error that is generally acceptable in the technical field to which the technology of the present disclosure belongs and that does not contradict the spirit of the technology of the present disclosure.

[0110] The servo pattern 58B is made up of a pair of linear magnetization regions 60B. In the example shown in Fig. 9, linear magnetization regions 60B1 and 60B2 are shown as an example of the pair of linear magnetization regions 60B. Each of the linear magnetization regions 60B1 and 60B2 is a linearly magnetized region.

[0111] In this embodiment, the linear magnetization region 60B1 is an example of a "first linear magnetization region" according to the technology of the present disclosure, and the linear magnetization region 60B2 is an example of a "second linear magnetization region" according to the technology of the present disclosure.

[0112] The linear magnetization regions 60B1 and 60B2 are tilted in opposite directions with respect to the imaginary line C2. In other words, the linear magnetization region 60B1 is tilted in one direction with respect to the imaginary line C2 (for example, the clockwise direction as viewed from the front side of the paper in FIG. 9 ). On the other hand, the linear magnetization region 60B2 is tilted in the other direction with respect to the imaginary line C2 (for example, the counterclockwise direction as viewed from the front side of the paper in FIG. 9 ).

[0113] The linear magnetization regions 60B1 and 60B2 are non-parallel to each other and inclined at different angles with respect to the virtual line C2. The linear magnetization region 60B1 has a steeper inclination angle with respect to the virtual line C2 than the linear magnetization region 60B2. Here, "steep" means, for example, that the angle of the linear magnetization region 60B1 with respect to the virtual line C2 is smaller than the angle of the linear magnetization region 60B2 with respect to the virtual line C2. Furthermore, the total length of the linear magnetization region 60B1 is shorter than the total length of the linear magnetization region 60B2.

[0114] In the servo pattern 58B, the linear magnetization region 60B1 is a collection of multiple magnetization lines 60B1a, and the linear magnetization region 60B2 is a collection of multiple magnetization lines 60B2a. Here, the magnetization lines 60B1a are an example of a "first magnetization line" according to the technology of the present disclosure, and the magnetization lines 60B2a are an example of a "second magnetization line" according to the technology of the present disclosure.

[0115] The number of magnetization lines 60B1a included in the linear magnetization region 60B1 is the same as the number of magnetization lines 60B2a included in the linear magnetization region 60B2. The linear magnetization region 60B1 is a collection of four magnetized lines 60B1a, and the linear magnetization region 60B2 is a collection of four magnetized lines 60B2a.

[0116] In this way, the number of magnetization lines 60A1a and the number of magnetization lines 60B1a differ between the servo patterns 58A and 58B, and the number of magnetization lines 60A2a and the number of magnetization lines 60B2a also differ.

[0117] Furthermore, the total number of magnetization lines 60B1a and 60B2a included in the servo pattern 58B is different from the total number of magnetization lines 60A1a and 60A2a included in the servo pattern 58A. In the example shown in Fig. 9, the total number of magnetization lines 60A1a and 60A2a included in the servo pattern 58A is 10, while the total number of magnetization lines 60B1a and 60B2a included in the servo pattern 58B is 8.

[0118] Within the servo band SB, the positions of both ends of the linear magnetization region 60B1 (i.e., the positions of both ends of each of the four magnetization lines 60B1a) and the positions of both ends of the linear magnetization region 60B2 (i.e., the positions of both ends of each of the four magnetization lines 60B2a) are aligned in the width direction WD.

[0119] Here, an example is given in which the positions of both ends of each of the four magnetization lines 60B1a and the positions of both ends of each of the four magnetization lines 60B2a are aligned, but this is merely one example, and it is sufficient that the positions of both ends of one or more of the four magnetization lines 60B1a and the positions of both ends of one or more of the four magnetization lines 60B2a are aligned.

[0120] Furthermore, here, an example of a linear magnetization region 60A1 is a set of five magnetized straight lines, namely, magnetization lines 60A1a; an example of a linear magnetization region 60A2 is a set of five magnetized straight lines, namely, magnetization lines 60A2a; an example of a linear magnetization region 60B1 is a set of four magnetized straight lines, namely, magnetization lines 60B1a; and an example of a linear magnetization region 60B2 is a set of four magnetized straight lines, namely, magnetization lines 60B2a; however, the technology disclosed herein is not limited to this. For example, the linear magnetization region 60A1 may be a number of magnetization lines 60A1a that contribute to determining the position of the magnetic head 28 on the magnetic tape MT, the linear magnetization region 60A2 may be a number of magnetization lines 60A2a that contribute to determining the position of the magnetic head 28 on the magnetic tape MT, the linear magnetization region 60B1 may be a number of magnetization lines 60B1a that contribute to determining the position of the magnetic head 28 on the magnetic tape MT, and the linear magnetization region 60B2 may be a number of magnetization lines 60B2a that contribute to determining the position of the magnetic head 28 on the magnetic tape MT.

[0121] Here, the geometric characteristics of the linear magnetized region pair 60A on the magnetic tape MT will be described with reference to Fig. 10. In this embodiment, the geometric characteristics refer to generally recognized geometric characteristics such as length, shape, orientation, and / or position.

[0122] 10 , the geometric characteristics of the linear magnetization region pair 60A on the magnetic tape MT can be expressed using a virtual linear region pair 62. The virtual linear region pair 62 consists of a virtual linear region 62A and a virtual linear region 62B. The geometric characteristics of the linear magnetization region pair 60A on the magnetic tape MT correspond to the geometric characteristics based on the virtual linear region pair 62 when the entire virtual linear region pair 62 is tilted with respect to the virtual line C1 by tilting the symmetry axis SA1 of the virtual linear region 62A and the virtual linear region 62B, which are tilted line-symmetrically with respect to the virtual line C1, with respect to the virtual line C1.

[0123] The virtual linear region pair 62 is a virtual linear magnetization region pair having the same geometric characteristics as the linear magnetization region pair 54A shown in Fig. 6. The virtual linear region pair 62 is a virtual magnetization region used for convenience in explaining the geometric characteristics of the linear magnetization region pair 60A on the magnetic tape MT, and is not an actual magnetization region.

[0124] The virtual linear region 62A has the same geometric characteristics as the linear magnetization region 54A1 shown in Fig. 6 and is made up of five virtual straight lines 62A1 corresponding to the five magnetization straight lines 54A1a shown in Fig. 6. The virtual linear region 62B has the same geometric characteristics as the linear magnetization region 54B1 shown in Fig. 6 and is made up of five virtual straight lines 62B1 corresponding to the five magnetization straight lines 54A2a shown in Fig. 6.

[0125] A center O1 is provided in the virtual linear region pair 62. For example, the center O1 is the center of a line segment L0 connecting the center of the straight line 62A1 located most upstream in the forward direction among the five straight lines 62A1 and the center of the straight line 62B1 located most downstream in the forward direction among the five straight lines 62B1.

[0126] Since the virtual linear region pair 62 has the same geometric characteristics as the linear magnetization region pair 54A shown in Figure 6, the virtual linear region 62A and the virtual linear region 62B are tilted symmetrically with respect to the virtual line C1. Now, consider a case where the servo read element SR reads the virtual linear region pair 62 when the entire virtual linear region pair 62 is tilted with respect to the virtual line C1 by tilting the symmetry axis SA1 of the virtual linear regions 62A and 62B by an angle a (e.g., 10 degrees) with respect to the virtual line C1 around the center O1 as the rotation axis. In this case, there are some portions of the virtual linear region pair 62 in the width direction WD where the virtual linear region 62A is read but the virtual linear region 62B is not, or where the virtual linear region 62A is not read but the virtual linear region 62B is read. That is, when reading is performed by the servo read element SR in each of the imaginary linear regions 62A and 62B, there are insufficient and unnecessary portions.

[0127] Therefore, by supplementing the missing parts and cutting out the unnecessary parts, the positions of both ends of the virtual linear region 62A (i.e., the positions of both ends of each of the five straight lines 62A1) and the positions of both ends of the virtual linear region 62B (i.e., the positions of both ends of each of the five straight lines 62B1) are aligned in the width direction WD.

[0128] The geometric characteristics of the virtual linear region pair 62 thus obtained (i.e., the geometric characteristics of the virtual servo pattern) correspond to the geometric characteristics of the actual servo pattern 58 A. That is, in the band-like region 61 (see FIG. 9 ), a linear magnetization region pair 60A having geometric characteristics equivalent to the geometric characteristics of the virtual linear region pair 62 obtained by aligning the positions of both ends of the virtual linear region 62A and the positions of both ends of the virtual linear region 62B in the width direction WD is recorded.

[0129] The linear magnetization region pair 60B differs from the linear magnetization region pair 60A only in that it has four magnetization lines 60B1a instead of five magnetization lines 60A1a and four magnetization lines 60B2a instead of five magnetization lines 60A2a. Therefore, in the strip region 61 (see FIG. 9 ), a linear magnetization region pair 60B having geometric characteristics equivalent to the geometric characteristics of a virtual linear region pair (not shown) obtained by aligning the positions of both ends of each of the four lines 62A1 and the positions of both ends of each of the four lines 62B1 in the width direction WD is recorded.

[0130] In this embodiment, as shown in FIG. 10 , by tilting the virtual linear regions 62A and 62B by an angle a with respect to the virtual line C1 around the center O1 as the rotation axis, a deficient portion and an unnecessary portion occur, so the deficient portion is compensated for and the unnecessary portion is removed. Here, in order to perform servo control, skew angle control, and / or tension control with high precision, it is preferable to match the amount of compensation for the deficient portion and the amount of removal of the unnecessary portion. In other words, it is preferable to eliminate any imbalance between one end and the other end of the servo pattern 58 in the width direction WD (for example, an imbalance between the amount of compensation for the deficient portion and the amount of removal of the unnecessary portion) and accurately determine the center position of the servo band SB in the width direction WD.

[0131] Therefore, in this embodiment, as an example, as shown in Figure 11, the length of the width SWD of the servo pattern SB is set based on the virtual straight line C5, position P1, position P2, position P3, distance D1, distance D2, distance D3, and distance D4.

[0132] Here, the virtual line C5 is an example of a "virtual line" according to the technology of the present disclosure. Position P1 is an example of a "first position" according to the technology of the present disclosure. Position P2 is an example of a "second position" according to the technology of the present disclosure. Position P3 is an example of a "third position" according to the technology of the present disclosure. Distance D1 is an example of a "first distance" according to the technology of the present disclosure. Distance D2 is an example of a "second distance" according to the technology of the present disclosure. Distance D3 is an example of a "distance from the virtual line to one end of the servo band in the width direction" according to the technology of the present disclosure. Distance D4 is an example of a "distance from the virtual line to the other end of the servo band in the width direction" according to the technology of the present disclosure.

[0133] The imaginary straight line C5 is set for the plurality of servo patterns 58 recorded in the servo band SB along the longitudinal direction LD. The imaginary straight line C5 crosses the plurality of servo patterns 58 along the longitudinal direction LD. Note that the imaginary straight line C5 is not a line actually recorded in the servo band SB, but is a virtual straight line used to set the width of the servo band SB.

[0134] The servo pattern 58A has positions P1 and P2. Position P1 is the position where the imaginary line C5 intersects with the linear magnetized region 60A1. Position P2 is the position where the imaginary line C5 intersects with the linear magnetized region 60A2.

[0135] 11 , the position where the imaginary line C5 intersects with the magnetization line 60A1a located at one end in the longitudinal direction LD of all the magnetization lines 60A1a included in the linear magnetization region 60A1 (in the example shown in FIG. 11 , the most upstream side in the running direction of the magnetic tape MT when the magnetic tape MT runs in the forward direction) is shown as position P1. Also, in the example shown in FIG. 11 , the position where the imaginary line C5 intersects with the magnetization line 60A2a located at one end in the longitudinal direction LD of all the magnetization lines 60A2a included in the linear magnetization region 60A2 (in the example shown in FIG. 11 , the most upstream side in the running direction of the magnetic tape MT when the magnetic tape MT runs in the forward direction) is shown as position P2.

[0136] The servo pattern 58B has a position P3, which is the position where the imaginary line C5 intersects with the linear magnetized region 60B1.

[0137] In the example shown in Figure 11, the position where the magnetization line 60B1a located at one end in the longitudinal direction LD (in the example shown in Figure 11, the most upstream side in the running direction of the magnetic tape MT when the magnetic tape MT runs in the forward direction) of all the magnetization lines 60B1a included in the linear magnetization region 60B1 intersects with the virtual line C5 is shown as position P3.

[0138] The imaginary line C5 is set at a position where a relationship is established such that the distance D1 between the servo patterns 58A and 58B adjacent in the longitudinal direction LD is half the distance D2 (for example, the ratio of the distance D1 to the distance D2 is 0.5). The distance D1 refers to the distance between the position P1 and the position P2 within one servo pattern 58A. The distance D2 refers to the distance between the position P1 and the position P3 between the adjacent servo patterns 58A and 58B. In this embodiment, "half" refers not only to the exact half, but also to a half that includes an error (for example, a few percent) that is generally acceptable in the technical field to which the technology of the present disclosure belongs and that does not contradict the spirit of the technology of the present disclosure.

[0139] The width of the servo band SB is set to a length such that a distance D3 from the imaginary line C5 to one end E1 matches a distance D4 from the imaginary line C5 to the other end E2. Note that in this embodiment, "match" refers to a match that includes an error that is generally acceptable in the technical field to which the technology of the present disclosure belongs, as well as a match that does not contradict the spirit of the technology of the present disclosure.

[0140] 12, a plurality of servo bands SB are formed on the magnetic tape MT in the width direction WD, and the frames 56 corresponding to each other between the servo bands SB are shifted by a predetermined interval in the longitudinal direction LD of the magnetic tape MT between the servo bands SB adjacent to each other in the width direction WD. This means that the servo patterns 58 corresponding to each other between the servo bands SB are shifted by a predetermined interval in the longitudinal direction LD of the magnetic tape MT between the servo bands SB adjacent to each other in the width direction WD.

[0141] The predetermined interval is determined based on the angle α, the pitch between adjacent servo bands SB in the width direction WD (hereinafter also referred to as the "servo band pitch"), and the frame length. In the example shown in Figure 12, the angle α is exaggerated to make it easier to understand visually, but in reality, the angle α is, for example, about 15 degrees. The angle α is the angle formed by the virtual line C1 and the frames 56 that do not have a corresponding relationship between adjacent servo bands SB in the width direction WD. In the example shown in Figure 12, an example of the angle α is the angle formed by the imaginary line C1 and a line segment L1 (in the example shown in Figure 12) between one frame 56 of a pair of corresponding frames 56 between adjacent servo bands SB in the width direction WD (in the example shown in Figure 12, one frame 56 in servo band SB3) and the frame 56 adjacent to the other frame 56 of the pair of frames 56 (in the example shown in Figure 12, one frame 56 in servo band SB2 that corresponds to one frame 56 in servo band SB3). In this case, the frame length refers to the total length of the frame 56 in the longitudinal direction LD of the magnetic tape MT. The predetermined interval is defined by the following mathematical formula (1). Note that Mod(A / B) means the remainder resulting when "A" is divided by "B".

[0142] (Predetermined interval) = Mod {(servo band pitch × tan α) / (frame length)} (1)

[0143] 12 illustrates the angle α as the angle formed by the imaginary line C1 between one frame 56 (hereinafter also referred to as the "first frame") of a pair of frames 56 corresponding to each other in the width direction WD between adjacent servo bands SB and the frame 56 adjacent to the other frame 56 (hereinafter also referred to as the "second frame") of the pair of frames 56. However, the technology of the present disclosure is not limited to this. For example, the angle α may be the angle formed by the imaginary line C1 between the first frame and a frame 56 (hereinafter also referred to as the "third frame") that is two or more frames away from the second frame within the same servo band SB as the second frame. In this case, the "frame length" used in equation (1) is the pitch between the second frame and the third frame in the longitudinal direction LD of the magnetic tape MT (e.g., the distance from the leading edge of the second frame to the leading edge of the third frame).

[0144] 13, when the servo read element SR reads the servo pattern 58A (i.e., the pair of linear magnetized regions 60A) in a state where the directions of the virtual straight lines C1 and C3 are aligned (i.e., the longitudinal direction of the magnetic head 28 is aligned with the width direction WD), a variation occurs due to azimuth loss between the servo signals derived from the linear magnetized regions 60A1 and 60A2. Also, when the servo read element SR reads the servo pattern 58B (i.e., the pair of linear magnetized regions 60B) in a state where the directions of the virtual straight lines C1 and C3 are aligned (i.e., the longitudinal direction of the magnetic head 28 is aligned with the width direction WD), a similar phenomenon occurs.

[0145] 14, as an example, the tilting mechanism 49 (see FIG. 8) skews the magnetic head 28 about the rotation axis RA on the magnetic tape MT so that the imaginary line C3 is tilted by an angle β (i.e., the angle β counterclockwise when viewed from the front side of the paper in FIG. 14) upstream in the forward direction relative to the imaginary line C1. Because the magnetic head 28 is tilted by an angle β upstream in the forward direction on the magnetic tape MT, the variation due to azimuth loss between the servo signals derived from the linear magnetized regions 60A1 and 60A2 is reduced compared to the example shown in FIG. 13. Similarly, when the servo read element SR reads the servo pattern 58B (i.e., the linear magnetized region pair 60B), the variation due to azimuth loss between the servo signals derived from the linear magnetized regions 60B1 and 60B2 is reduced.

[0146] Here, the angle β is set to coincide with the angle a (see FIG. 10), which is the angle obtained by rotating the symmetry axis SA1 (see FIG. 10) of the virtual linear regions 62A and 62B (see FIG. 10) with respect to the virtual line C1, with the center O1 (see FIG. 10) as the rotation axis. The geometric characteristics of the virtual linear regions 62A and 62B are the same as those of the linear magnetized regions 60A1 and 60B1. Therefore, the linear magnetized regions 60A1 and 60B1 are also inclined by the angle a with respect to the virtual line C1. In this case, when the magnetic head 28 is inclined at the angle β (i.e., the angle a) upstream in the forward direction on the magnetic tape MT, the inclination angle β of the magnetic head 28 coincides with the inclination angle a of the linear magnetized regions 60A1 and 60A2. As a result, the variation due to azimuth loss between the servo signals derived from the linear magnetized regions 60A1 and 60A2 is reduced. Similarly, when the servo pattern 58B (i.e., the linear magnetization region pair 60B) is read by the servo read element SR, the variation due to azimuth loss between the servo signal derived from the linear magnetization region 60B1 and the servo signal derived from the linear magnetization region 60B2 is reduced.

[0147] 15, the control device 30 includes a control unit 30A and a position detection unit 30B. The position detection unit 30B includes a first position detection unit 30B1 and a second position detection unit 30B2. The position detection unit 30B acquires a servo signal resulting from the servo pattern 58 being read by the servo read element SR, and detects the position of the magnetic head 28 on the magnetic tape MT based on the acquired servo signal.

[0148] The servo signals are classified into a first servo signal and a second servo signal. The first servo signal is a servo signal resulting from reading the servo pattern 58 by the servo read element SR1, and the second servo signal is a servo signal resulting from reading the servo pattern 58 by the servo read element SR2.

[0149] The first position detection unit 30B1 acquires a first servo signal, and the second position detection unit 30B2 acquires a second servo signal. In the example shown in Fig. 15, the first position detection unit 30B1 acquires a first servo signal obtained by the servo read element SR1 reading the servo pattern 58 in the servo band SB2, and the second position detection unit 30B2 acquires a second servo signal obtained by the servo read element SR2 reading the servo pattern 58 in the servo band SB3. The first position detection unit 30B1 detects the position of the servo read element SR1 relative to the servo band SB2 based on the first servo signal, and the second position detection unit 30B2 detects the position of the servo read element SR2 relative to the servo band SB3 based on the second servo signal.

[0150] The control unit 30A performs various controls based on the position detection result from the first position detection unit 30B1 (i.e., the result of position detection by the first position detection unit 30B1) and the position detection result from the second position detection unit 30B2 (i.e., the result of position detection by the second position detection unit 30B2). Here, the various controls refer to, for example, servo control, skew angle control, and / or tension control. Tension control refers to control of the tension applied to the magnetic tape MT (e.g., tension to reduce the effects of TDS).

[0151] As an example, as shown in FIG. 16, the position detector 30B detects a servo signal, which is the result of the servo pattern 58 being read from the magnetic tape MT by the servo read element SR, using an autocorrelation coefficient.

[0152] An ideal waveform signal 66 is stored in the storage 32. The ideal waveform signal 66 is a signal indicating a single ideal waveform included in the servo signal (for example, an ideal signal resulting from reading one of the ideal magnetization lines included in the servo pattern 58 by the servo read element SR). The ideal waveform signal 66 can also be considered a sample signal to be compared with the servo signal. Note that while an example in which the ideal waveform signal 66 is stored in the storage 32 is given here, this is merely an example. For example, the ideal waveform signal 66 may be stored in the cartridge memory 24 instead of or in addition to the storage 32. The ideal waveform signal 66 may also be recorded in a BOT area (not shown) provided at the beginning of the magnetic tape MT and / or an EOT area (not shown) provided at the end of the magnetic tape MT.

[0153] The autocorrelation coefficient used by the position detection unit 30B is a coefficient that indicates the degree of correlation between the servo signal and the ideal waveform signal 66. The position detection unit 30B acquires the ideal waveform signal 66 from the storage 32 and compares the acquired ideal waveform signal 66 with the servo signal. The position detection unit 30B then calculates the autocorrelation coefficient based on the comparison result. The position detection unit 30B detects positions on the servo band SB where the correlation between the servo signal and the ideal waveform signal 66 is high (for example, positions where the servo signal and the ideal waveform signal 66 match) according to the autocorrelation coefficient.

[0154] The position of the servo read element SR relative to the servo band SB is detected based on, for example, the distance between the servo patterns 58A and 58B in the longitudinal direction LD. For example, the distance between the servo patterns 58A and 58B in the longitudinal direction LD is detected according to an autocorrelation coefficient. When the servo read element SR is located above the servo pattern 58 (i.e., above the front view of the paper in FIG. 15), the distance between the linear magnetization region 60A1 and the linear magnetization region 60A2 is narrow, and the distance between the linear magnetization region 60B1 and the linear magnetization region 60B2 is also narrow. On the other hand, when the servo read element SR is located below the servo pattern 58 (i.e., below the front view of the paper in FIG. 15), the distance between the linear magnetization region 60A1 and the linear magnetization region 60A2 is wide, and the distance between the linear magnetization region 60B1 and the linear magnetization region 60B2 is also wide. In this way, the position detection unit 30B detects the position of the servo read element SR relative to the servo band SB using the distance between the linear magnetization region 60A1 and the linear magnetization region 60A2, and the distance between the linear magnetization region 60B1 and the linear magnetization region 60B2, detected according to the autocorrelation coefficient.

[0155] The control unit 30A adjusts the position of the magnetic head 28 by operating the movement mechanism 48 based on the position detection result of the position detection unit 30B (i.e., the result of the position detection by the position detection unit 30B). The control unit 30A also causes the magnetic element unit 42 to perform magnetic processing on the data band DB of the magnetic tape MT. That is, the control unit 30A obtains a read signal from the magnetic element unit 42 (i.e., data read from the data band DB of the magnetic tape MT by the magnetic element unit 42) and supplies a recording signal to the magnetic element unit 42 to record data corresponding to the recording signal in the data band DB of the magnetic tape MT.

[0156] Furthermore, to reduce the effects of TDS, the control unit 30A calculates the servo band pitch from the position detection result of the position detection unit 30B, and performs tension control and skews the magnetic head 28 on the magnetic tape MT according to the calculated servo band pitch. Tension control is achieved by adjusting the rotation speed and rotation torque of each of the feed motor 36 and the take-up motor 40. Skew of the magnetic head 28 is achieved by operating a tilt mechanism 49.

[0157] Next, among the multiple processes included in the manufacturing process of the magnetic tape MT, we will explain an example of a servo pattern recording process that forms a servo band SB (see Figures 9 and 11) by recording a servo pattern 58 in a strip area 61 (see Figures 9 and 11) of the magnetic tape MT, and a winding process that winds up the magnetic tape MT.

[0158] 17, the servo pattern recording process uses a servo writer SW, which includes a supply reel SW1, a take-up reel SW2, a drive unit SW3, a pulse signal generator SW4, a control unit SW5, a plurality of guides SW6, a transport path SW7, a servo pattern recording head WH, and a verify head VH.

[0159] In this embodiment, the servo writer SW is an example of a "servo pattern recording device" and an "inspection device" according to the technology of the present disclosure. Also, in this embodiment, the pulse signal generator SW4 is an example of a "pulse signal generator" according to the technology of the present disclosure. Also, in this embodiment, the servo pattern recording head WH is an example of a "servo pattern recording head" according to the technology of the present disclosure. Also, in this embodiment, the control device SW5 is an example of an "inspection processor" according to the technology of the present disclosure.

[0160] The control device SW5 controls the entire servo writer SW. In this embodiment, the control device SW5 is realized by an ASIC, but the technology of the present disclosure is not limited to this. For example, the control device SW5 may be realized by an FPGA and / or a PLC. The control device SW5 may also be realized by a computer including a CPU, flash memory (e.g., EEPROM and / or SSD), and RAM. The control device SW5 may also be realized by a combination of two or more of the ASIC, FPGA, PLC, and computer. In other words, the control device SW5 may be realized by a combination of hardware and software.

[0161] A pancake is set on the supply reel SW1. The pancake refers to a large diameter roll of magnetic tape MT, which is cut to the product width from a wide web before the servo pattern 58 is written, wound around a hub.

[0162] The drive unit SW3 has a motor (not shown) and gears (not shown) and is mechanically connected to the supply reel SW1 and the take-up reel SW2. When the magnetic tape MT is wound by the take-up reel SW2, the drive unit SW3 generates power in accordance with instructions from the control unit SW5 and transmits the generated power to the supply reel SW1 and the take-up reel SW2, thereby rotating the supply reel SW1 and the take-up reel SW2. That is, the supply reel SW1 receives power from the drive unit SW3 and rotates to feed the magnetic tape MT to the predetermined transport path SW7. The take-up reel SW2 receives power from the drive unit SW3 and rotates to wind the magnetic tape MT fed from the supply reel SW1. The rotation speeds and rotation torques of the supply reel SW1 and the take-up reel SW2 are adjusted according to the speed at which the magnetic tape MT is wound around the take-up reel SW2.

[0163] A plurality of guides SW6 and a servo pattern recording head WH are arranged on the transport path SW7. The servo pattern recording head WH is arranged on the surface 31 side of the magnetic tape MT between the plurality of guides SW6. The magnetic tape MT sent out from the supply reel SW1 to the transport path SW7 is guided by the plurality of guides SW6, passes over the servo pattern recording head WH, and is taken up by the take-up reel SW2.

[0164] The pulse signal generator SW4 generates a pulse signal under the control of the control device SW5 and supplies the generated pulse signal to the servo pattern recording head WH. While the magnetic tape MT is traveling at a constant speed on the transport path SW, the servo pattern recording head WH forms a servo band SB by recording a servo pattern 58 in a strip-shaped area 61 in accordance with the pulse signal supplied from the pulse signal generator SW4.

[0165] The servo pattern recording process includes an inspection process. For example, the inspection process is a process of inspecting the servo bands SB formed on the surface 31 of the magnetic tape MT by the servo pattern recording head WH. The inspection of the servo bands SB refers to, for example, a first judgment process and a second judgment process. The first judgment process refers to a process of determining whether the width SWD (see FIG. 11) of the servo bands SB is set within the allowable error. The second judgment process refers to a process of determining whether the servo patterns 58 recorded on the servo bands SB are correct (for example, a process of determining whether the magnetization lines 60A1a, 60A2a, 60B1a, and 60B2a are recorded with sufficient length and within the allowable error relative to the band-shaped area 61 (see FIG. 11) (i.e., verifying the servo patterns 58)).

[0166] The inspection process is performed using the control device SW5 and the verify head VH. The verify head VH is located downstream of the servo pattern recording head WH in the transport direction of the magnetic tape MT. Similarly to the magnetic head 28, the verify head VH is provided with multiple servo read elements (not shown), which read multiple servo bands SB. Similarly to the magnetic head 28, the verify head VH is skewed above the surface 31 of the magnetic tape MT.

[0167] The verify head VH is connected to the control device SW5. The verify head VH is positioned directly opposite the servo bands SB when viewed from the surface 31 side of the magnetic tape MT (i.e., the back side of the verify head VH). The verify head VH reads the servo patterns 58 recorded on the servo bands SB and outputs the read results (hereinafter referred to as "servo pattern read results") to the control device SW5. The control device SW5 inspects the servo bands SB (e.g., determines whether the servo patterns 58 are correct) based on the servo pattern read results (e.g., servo signals) input from the verify head VH. For example, the control device SW5 operates as the position detection unit 30B shown in FIG. 15 to obtain position detection results from the servo pattern read results and inspects the servo bands SB by using the position detection results to determine whether the servo patterns 58 are correct.

[0168] The control device SW5 controls the servo writer SW by referring to the results of the inspection of the servo band SB (e.g., the results of the first judgment process and the second judgment process). For example, if the first judgment process determines that the width SWD (see FIG. 11) is not set within the allowable error, the control device SW5 controls the pulse signal generator SW4 and / or the drive device SW3, etc., based on the servo pattern reading result, to set the width SWD to a length that matches the distance D3 and the distance D4, as shown in FIG. 11. The reason for controlling the pulse signal generator SW4 and / or the drive device SW3, etc., is that the length corresponding to the distance D1 shown in FIG. 11 is determined by the gap pattern G (see FIGS. 18 and 19) of the servo pattern recording head WH, and therefore it is necessary to adjust the distance D2 shown in FIG. 11 in order to set the distance D1 to half the distance D2. 11 , it is necessary to fine-tune the timing of pulse signal generation and adjust the running speed of the magnetic tape MT, and therefore the pulse signal generator SW4 and / or the drive device SW3, etc. are controlled by the control device SW5. Furthermore, when the second determination process determines that the servo pattern 58 recorded in the servo band SB is incorrect, the control device SW5 controls the pulse signal generator SW4 and / or the servo pattern recording head WH, etc., based on the servo pattern reading result, to record the magnetization lines 60A1a, 60A2a, 60B1a, and 60B2a in the strip area 61 (see FIG. 11 ) exactly and within the allowable error. The control device SW5 may output information indicating the results of inspecting the servo band SB to a predetermined output destination (e.g., the storage 32 (see FIG. 3 ), the UI device 34 (see FIG. 3 ), and / or the external device 37 (see FIG. 3 )).

[0169] For example, after the inspection process is completed, the winding process is carried out next. The winding process is a process of winding the magnetic tape MT around the supply reel 22 (see FIGS. 2 to 4) housed in the magnetic tape cartridge 12 (see FIGS. 1 to 4)) used for each of the multiple magnetic tape cartridges 12 (see FIGS. 1 to 4). In the winding process, a winding motor M is used. The winding motor M is mechanically connected to the supply reel 22 via a gear or the like. Under the control of a control device (not shown), the winding motor M applies a rotational force to the supply reel 22 to rotate the supply reel 22. The magnetic tape MT wound around the take-up reel SW2 is wound onto the supply reel 22 by the rotation of the supply reel 22. In the winding process, a cutting device (not shown) is used. When the required amount of magnetic tape MT is wound onto each of the plurality of supply reels 22, the magnetic tape MT fed from the take-up reel SW2 to the supply reel 22 is cut by a cutting device.

[0170] Figure 18 shows an example of the configuration of the servo pattern recording head WH when observed from the surface 31 side (i.e., the back side of the servo pattern recording head WH) of the magnetic tape MT running on the transport path SW7 (see Figure 17), and an example of the configuration of the pulse signal generator SW4.

[0171] 18, the servo pattern recording head WH has a base body WH1 and a plurality of head cores WH2. The base body WH1 is formed in a rectangular parallelepiped shape and is arranged to cross the surface 31 of the magnetic tape MT running on the transport path SW7 in the width direction WD. The surface WH1A of the base body WH1 is rectangular with a long side WH1Aa and a short side WH1Ab, and the long side WH1Aa crosses the surface 31 of the magnetic tape MT in the width direction WD.

[0172] The surface WH1A has a sliding surface WH1Ax. The sliding surface WH1Ax is a part of the surface WH1A that overlaps with the surface 31 of the magnetic tape MT when the substrate WH1 crosses over the surface 31 of the magnetic tape MT in the width direction WD (e.g., the dotted hatched area shown in FIG. 18 ), and slides against the running magnetic tape MT. The width of the sliding surface WH1Ax shown in FIG. 18 (i.e., the length in the direction LD1 corresponding to the longitudinal direction LD (e.g., the same direction as the longitudinal direction LD)) is merely an example, and the width of the sliding surface WH1Ax may be several times wider than the example shown in FIG. 18 .

[0173] The direction WD1, which is the longitudinal direction of the base body WH1 (i.e., the direction along the long side WH1Aa), corresponds to the width direction WD (e.g., the same direction as the width direction WD). A plurality of head cores WH2 are incorporated into the base body WH1 along the direction WD1. A gap pattern G is formed in the head cores WH2. The gap pattern G is formed on the surface WH1A (i.e., the surface of the base body WH1 facing the surface 31 of the magnetic tape MT). The gap pattern G is also made up of a pair of non-parallel straight line regions. A pair of non-parallel linear regions refers to, for example, a linear region having the same geometric characteristics as the magnetization line 60A1a located at the most upstream side in the forward direction of the five magnetization lines 60A1a included in the linear magnetization region 60A1 shown in Figure 9, and a linear region having the same geometric characteristics as the magnetization line 60A2a located at the most upstream side in the forward direction of the five magnetization lines 60A2a included in the linear magnetization region 60A2 shown in Figure 9.

[0174] A plurality of gap patterns G are formed on the surface WH1A along the direction WD1. On the surface WH1A, the distance in the direction WD1 between adjacent gap patterns G in the direction WD1 corresponds to the distance in the width direction WD between the band-like regions 61 of the magnetic tape MT (i.e., the servo band pitch).

[0175] A coil (not shown) is wound around the head core WH2, and pulse signals are supplied to the coil, including a pulse signal for the servo pattern 58A and a pulse signal for the servo pattern 58B.

[0176] When a pulse signal for servo pattern 58A is supplied to the coil of head core WH2 with gap pattern G facing band-like region 61 of magnetic tape MT running on transport path SW7, a magnetic field is applied from gap pattern G to band-like region 61 of magnetic tape MT in accordance with the pulse signal. As a result, servo pattern 58A is recorded in band-like region 61. Also, when gap pattern G faces band-like region 61 of magnetic tape MT running on transport path SW7, a pulse signal for servo pattern 58B is supplied to the coil of head core WH2, and a magnetic field is applied from gap pattern G to band-like region 61 of magnetic tape MT. In this way, servo band SB is formed by recording servo pattern 58B in band-like region 61 (see FIGS. 9 and 11).

[0177] The pulse signal corresponding to each servo pattern 58 (i.e., the servo pattern 58 for each frame 56 (see FIG. 9 )) is modulated. By modulating the pulse signal, various pieces of information are embedded in the pulse signal. In this case, for example, by modulating the pulse signal for the servo pattern 58A, it is possible to change the interval between the third magnetization line 60A1a and the second magnetization line 60A1a (hereinafter referred to as the "first interval") and the interval between the third magnetization line 60A1a and the fourth magnetization line 60A1a (hereinafter referred to as the "second interval") among the five magnetization lines 60A1a (see FIG. 9 ) for each servo pattern 58A. By making the first interval and the second interval different for each servo pattern 58A, it is possible to embed at least one bit of information in each servo pattern 58A. This makes it possible to embed various pieces of information by combining multiple servo patterns 58.

[0178] The various information includes, for example, information about the position of the magnetic tape MT in the longitudinal direction LD, information for identifying the servo band SB, and / or information for identifying the manufacturer of the magnetic tape MT.

[0179] 18 shows head cores WH2A, WH2B, and WH2C as examples of the plurality of head cores WH2, and gap patterns G1, G2, and G3 as examples of the plurality of gap patterns G. Gap pattern G1 is formed in head core WH2A. Gap pattern G2 is formed in head core WH2B. Gap pattern G3 is formed in head core WH2C.

[0180] Gap patterns G1 to G3 have the same geometric characteristics as each other. In this embodiment, for example, gap pattern G1 is used to record servo pattern 58 (see FIG. 9) for servo band SB3 (see FIG. 9), gap pattern G2 is used to record servo pattern 58 (see FIG. 9) for servo band SB2 (see FIG. 9), and gap pattern G3 is used to record servo pattern 58 (see FIG. 9) for servo band SB1 (see FIG. 9).

[0181] Gap pattern G1 is a pair of linear regions consisting of linear regions G1A and G1B, gap pattern G2 is a pair of linear regions consisting of linear regions G2A and G2B, and gap pattern G3 is a pair of linear regions consisting of linear regions G3A and G3B.

[0182] In this embodiment, the linear region pair consisting of linear regions G1A and G1B, the linear region pair consisting of linear regions G2A and G2B, and the linear region pair consisting of linear regions G3A and G3B are examples of "linear region pairs" according to the technology of the present disclosure. Also, in this embodiment, the linear regions G1A, G2A, and G3A are examples of "first linear region" according to the technology of the present disclosure. Also, in this embodiment, the linear regions G1B, G2B, and G3B are examples of "second linear region" according to the technology of the present disclosure.

[0183] The pulse signal generator SW4 has a first pulse signal generator SW4A, a second pulse signal generator SW4B, and a third pulse signal generator SW4C. The first pulse signal generator SW4A is connected to the head core WH2A. The second pulse signal generator SW4B is connected to the head core WH2B. The third pulse signal generator SW4C is connected to the head core WH2C.

[0184] When the gap pattern G1 is used for the strip area 61 (see FIG. 9) corresponding to the servo band SB3, the first pulse signal generator SW4A supplies a pulse signal to the head core WH2A, and a magnetic field is applied from the gap pattern G1 to the strip area 61 corresponding to the servo band SB3 in accordance with the pulse signal, and the servo pattern 58 (see FIG. 9) is recorded in the strip area 61 corresponding to the servo band SB3. This forms the servo band SB3 on the magnetic tape MT.

[0185] For example, when the gap pattern G1 faces the strip area 61 corresponding to the servo band SB3 of the magnetic tape MT running on the transport path SW7 and a pulse signal for the servo pattern 58A is supplied to the head core WH2A, the servo pattern 58A (see FIG. 9) is recorded in the strip area 61 corresponding to the servo band SB3. That is, a linear magnetization area 60A1 (see FIG. 9) is recorded by the linear area G1A in the strip area 61 corresponding to the servo band SB3, and a linear magnetization area 60A2 (see FIG. 9) is recorded by the linear area G1B in the strip area 61 corresponding to the servo band SB3.

[0186] Also, for example, when the gap pattern G1 faces the strip area 61 corresponding to the servo band SB3 of the magnetic tape MT running on the transport path SW7, if a pulse signal for the servo pattern 58B is supplied to the head core WH2A, the servo pattern 58B (see FIG. 9) is recorded in the strip area 61 corresponding to the servo band SB3. That is, a linear magnetization area 60B1 (see FIG. 9) is recorded by the straight area G1A in the strip area 61 corresponding to the servo band SB3, and a linear magnetization area 60B2 (see FIG. 9) is recorded by the straight area G1B in the strip area 61 corresponding to the servo band SB3.

[0187] In this way, the servo patterns 58A and 58B are alternately recorded in the strip-like area 61 corresponding to the servo band SB3, thereby forming the servo band SB3 on the magnetic tape MT.

[0188] When the gap pattern G2 is used for the strip area 61 (see FIG. 9) corresponding to the servo band SB2, the second pulse signal generator SW4B supplies a pulse signal to the head core WH2B, and a magnetic field is applied from the gap pattern G2 to the strip area 61 corresponding to the servo band SB2 in accordance with the pulse signal, and the servo pattern 58 is recorded in the strip area 61 corresponding to the servo band SB2. This forms the servo band SB2 on the magnetic tape MT.

[0189] For example, when the gap pattern G2 faces the strip area 61 corresponding to the servo band SB2 of the magnetic tape MT running on the transport path SW7, and a pulse signal for the servo pattern 58A is supplied to the head core WH2B, the servo pattern 58A (see FIG. 9) is recorded in the strip area 61 corresponding to the servo band SB2. That is, a linear magnetization area 60A1 is recorded by the linear area G2A in the strip area 61 corresponding to the servo band SB2, and a linear magnetization area 60A2 is recorded by the linear area G2B in the strip area 61 corresponding to the servo band SB2.

[0190] Also, for example, when the gap pattern G2 faces the strip area 61 corresponding to the servo band SB2 of the magnetic tape MT running on the transport path SW7, if a pulse signal for the servo pattern 58B is supplied to the head core WH2B, the servo pattern 58B is recorded in the strip area 61 corresponding to the servo band SB2. That is, a linear magnetization area 60B1 is recorded by the straight line area G2A in the strip area 61 corresponding to the servo band SB2, and a linear magnetization area 60B2 is recorded by the straight line area G2B in the strip area 61 corresponding to the servo band SB2.

[0191] In this way, the servo patterns 58A and 58B are alternately recorded in the strip-like area 61 corresponding to the servo band SB2, thereby forming the servo band SB2 on the magnetic tape MT.

[0192] When the gap pattern G3 is used for the strip area 61 (see FIG. 9) corresponding to the servo band SB1, the third pulse signal generator SW4C supplies a pulse signal to the head core WH2C, and a magnetic field is applied from the gap pattern G3 to the strip area 61 corresponding to the servo band SB1 in accordance with the pulse signal, and the servo pattern 58 is recorded in the strip area 61 corresponding to the servo band SB1. This forms the servo band SB1 on the magnetic tape MT.

[0193] For example, when the gap pattern G3 faces the strip area 61 corresponding to the servo band SB1 of the magnetic tape MT running on the transport path SW7, and a pulse signal for the servo pattern 58A is supplied to the head core WH2C, the servo pattern 58A is recorded in the strip area 61 corresponding to the servo band SB1. That is, a linear magnetized area 60A1 is recorded by the linear area G3A in the strip area 61 corresponding to the servo band SB1, and a linear magnetized area 60A2 is recorded by the linear area G3B in the strip area 61 corresponding to the servo band SB1. This forms the servo band SB1 on the magnetic tape MT.

[0194] Furthermore, for example, when the gap pattern G3 faces the strip area 61 corresponding to the servo band SB1 of the magnetic tape MT running on the transport path SW7, if a pulse signal for the servo pattern 58B is supplied to the head core WH2C, the servo pattern 58B is recorded in the strip area 61 corresponding to the servo band SB1. That is, a linear magnetization area 60B1 is recorded by the linear area G3A in the strip area 61 corresponding to the servo band SB1, and a linear magnetization area 60B2 is recorded by the linear area G3B in the strip area 61 corresponding to the servo band SB1.

[0195] In this way, the servo patterns 58A and 58B are alternately recorded in the strip-like area 61 corresponding to the servo band SB1, thereby forming the servo band SB1 on the magnetic tape MT.

[0196] 19, in gap pattern G1, linear regions G1A and G1B are inclined in opposite directions relative to a straight line along direction WD1, i.e., a virtual line C1. In other words, linear region G1A is inclined in one direction relative to virtual line C1 (e.g., a clockwise direction as viewed from the front side of the paper in FIG. 19). On the other hand, linear region G1B is inclined in another direction relative to virtual line C1 (e.g., a counterclockwise direction as viewed from the front side of the paper in FIG. 19).

[0197] Furthermore, the linear region G1A has a steeper inclination angle with respect to the virtual line C1 than the linear region G1B. Here, "steep" means, for example, that the angle of the linear region G1A with respect to the virtual line C1 is smaller than the angle of the linear region G1B with respect to the virtual line C1. Furthermore, the positions of both ends of the linear region G1A and the positions of both ends of the linear region G1B are aligned in the direction WD1. Furthermore, the overall length of the linear region G1A is shorter than the overall length of the linear region G1B.

[0198] In the gap pattern G2, the linear regions G2A and G2B are inclined in opposite directions with respect to the imaginary line C1. In other words, the linear region G2A is inclined in one direction with respect to the imaginary line C1 (e.g., clockwise as viewed from the front side of the paper in FIG. 19 ), while the linear region G2B is inclined in the other direction with respect to the imaginary line C1 (e.g., counterclockwise as viewed from the front side of the paper in FIG. 19 ).

[0199] Furthermore, the linear region G2A has a steeper inclination angle relative to the virtual line C1 than the linear region G2B. Here, "steep" means, for example, that the angle of the linear region G2A relative to the virtual line C1 is smaller than the angle of the linear region G2B relative to the virtual line C1. Furthermore, the positions of both ends of the linear region G2A and the positions of both ends of the linear region G2B are aligned in the direction WD1. Furthermore, the overall length of the linear region G2A is shorter than the overall length of the linear region G2B.

[0200] In the gap pattern G3, the linear regions G3A and G3B are inclined in opposite directions with respect to the imaginary line C1. In other words, the linear region G3A is inclined in one direction with respect to the imaginary line C1 (e.g., clockwise as viewed from the front side of the paper in FIG. 19 ), while the linear region G3B is inclined in the other direction with respect to the imaginary line C1 (e.g., counterclockwise as viewed from the front side of the paper in FIG. 19 ).

[0201] Furthermore, the linear region G3A has a steeper inclination angle relative to the virtual line C1 than the linear region G3B. Here, "steep" means, for example, that the angle of the linear region G3A relative to the virtual line C1 is smaller than the angle of the linear region G3B relative to the virtual line C1. Furthermore, the positions of both ends of the linear region G3A and the positions of both ends of the linear region G3B are aligned in the direction WD1. Furthermore, the overall length of the linear region G3A is shorter than the overall length of the linear region G3B.

[0202] The gap patterns G1, G2, and G3 are offset in the direction LD1 by the above-mentioned predetermined interval (i.e., the predetermined interval calculated from the formula (1)) between gap patterns G adjacent to each other in the direction WD1.

[0203] On the surface WH1A, the long side WH1Aa is longer than the width of the magnetic tape MT. The short side WH1Ab has a length that accommodates all of the gap patterns G1, G2, and G3. In other words, the length that accommodates all of the gap patterns G1, G2, and G3 refers to the length that accommodates the linear region G1A to the linear region G3B along the longitudinal direction LD of the magnetic tape MT. The direction of the long side WH1Aa coincides with the width direction WD, and the direction of the short side WH1Ab coincides with the longitudinal direction LD of the magnetic tape MT. The base WH1 is arranged on the surface 31 side of the magnetic tape MT, with the multiple gap patterns G and the surface 31 facing each other, and across the magnetic tape MT in the width direction WD.

[0204] The pulse signals used between gap patterns G1, G2, and G3 (i.e., as shown in FIG. 18, the pulse signal supplied from the first pulse signal generator SW4A to the head core WH2A, the pulse signal supplied from the second pulse signal generator SW4B to the head core WH2B, and the pulse signal supplied from the third pulse signal generator SW4C to the head core WH2C) are signals of the same phase.

[0205] In the servo pattern recording process, the magnetic tape MT runs at a constant speed on the transport path SW7 with the gap pattern G1 aligned with the strip area 61 corresponding to the servo band SB3, the gap pattern G2 aligned with the strip area 61 corresponding to the servo band SB2, and the gap pattern G3 aligned with the strip area 61 corresponding to the servo band SB1. In this state, pulse signals for the servo patterns 58A and 58B are alternately supplied to the head cores WH2A, WH2B, and WH2C.

[0206] When pulse signals for servo pattern 58A are supplied in phase to head cores WH2A, WH2B, and WH2C, servo pattern 58A is recorded on servo bands SB3, SB2, and SB1 with a predetermined interval offset in the longitudinal direction LD of magnetic tape MT. Also, when pulse signals for servo pattern 58B are supplied in phase to head cores WH2A, WH2B, and WH2C, servo pattern 58B is recorded on servo bands SB3, SB2, and SB1 with a predetermined interval offset in the longitudinal direction LD of magnetic tape MT.

[0207] Here, the geometric characteristics of the gap pattern G on the surface WH1A will be described with reference to FIG.

[0208] 20, the geometric characteristics of the gap pattern G on the surface WH1A can be expressed using a pair of imaginary straight line regions 68. The pair of imaginary straight line regions 68 consists of an imaginary straight line region 68A and an imaginary straight line region 68B.

[0209] The imaginary straight line region pair 68 is a virtual straight line region pair having the same geometric characteristics as the gap pattern G shown in Fig. 19. The imaginary straight line region pair 68 is a virtual straight line region pair used for convenience in explaining the geometric characteristics on the surface WH1A of the gap pattern G, and is not an actual straight line region pair.

[0210] In this embodiment, for example, the imaginary straight line region 68A has the same geometric characteristics as the straight line region G1A shown in FIG. 19, and the imaginary straight line region 68B has the same geometric characteristics as the straight line region G1B shown in FIG.

[0211] A center O2 is provided in the pair of imaginary straight line regions 68. For example, the center O2 is the center of a line segment L2 that connects the center of the imaginary straight line region 68A and the center of the imaginary straight line region 68B.

[0212] The imaginary straight line region 68A and the imaginary straight line region 68B are tilted axisymmetrically with respect to the imaginary line C1. Here, when the symmetry axis SA2 of the imaginary straight line region 68A and the imaginary straight line region 68B is tilted by an angle b (e.g., 10 degrees) with respect to the imaginary line C1 around the center O2 as the rotation axis, thereby tilting the entire imaginary straight line region pair 68 with respect to the imaginary line C1, comparing the imaginary straight line region pair 68 with the imaginary linear region pair 62 shown in FIG. 10 , it is found that the imaginary straight line region pair 68 has insufficient and unnecessary portions. Here, the insufficient portions refer to portions that are insufficient for the servo pattern recording head WH to record the servo patterns 58 on the magnetic tape MT, and the unnecessary portions refer to portions that are unnecessary for the servo pattern recording head WH to record the servo patterns 58 on the magnetic tape MT. The example shown in FIG. 20 illustrates an example in which the imaginary straight line region 68B has insufficient and unnecessary portions.

[0213] Therefore, by supplementing the missing portions and removing the unnecessary portions, the positions of both ends of the imaginary straight line region 68A and the positions of both ends of the imaginary straight line region 68B in the direction WD1 are aligned.

[0214] The geometric characteristics of the virtual straight line region pair 68 obtained in this manner (i.e., the geometric characteristics of the virtual gap pattern) correspond to the geometric characteristics of the actual gap pattern G. That is, on the surface WH1A (see FIG. 19 ), a gap pattern G having geometric characteristics corresponding to the geometric characteristics of the virtual straight line region pair 68 obtained by aligning the positions of both ends of the virtual straight line region 68A and the positions of both ends of the virtual straight line region 68B in the direction WD1 is formed.

[0215] The configurations shown in FIGS. 18 to 20 are merely examples, and it is possible to form servo bands SB on the magnetic tape MT with other configurations.

[0216] Next, the operation of the magnetic tape system 10 will be described.

[0217] The magnetic tape cartridge 12 contains a magnetic tape MT manufactured by a servo writer SW. The magnetic tape cartridge 12 is loaded into a magnetic tape drive 14. In the magnetic tape drive 14, when magnetic processing is performed on the magnetic tape MT by a magnetic element unit 42 (see FIGS. 3 and 16), the magnetic tape MT is pulled out of the magnetic tape cartridge 12, and the servo read element SR of the magnetic head 28 reads the servo patterns 58 in the servo bands SB.

[0218] 9 and 10, the linear magnetized regions 60A1 and 60A2 included in the servo pattern 58A recorded on the servo band SB of the magnetic tape MT are tilted in opposite directions with respect to the virtual line C1. Meanwhile, as shown in FIG. 14, the magnetic head 28 on the magnetic tape MT is also tilted upstream in the forward direction by an angle β (i.e., an angle β counterclockwise when viewed from the front side of the paper in FIG. 14). When the servo pattern 58A is read by the servo read element SR in this state, the angle between the linear magnetized region 60A1 and the servo read element SR and the angle between the linear magnetized region 60A2 and the servo read element SR become close, so that the variation in the servo signal due to azimuth loss is smaller than the variation occurring between the servo signal derived from the linear magnetized region 54A1 included in the conventional servo pattern 52A and the servo signal derived from the linear magnetized region 54A2 included in the conventional servo pattern 52A.

[0219] As a result, the variation between the servo signals derived from the linear magnetization regions 60A1 and 60A2 is smaller than the variation between the servo signals derived from the linear magnetization regions 54A1 and 54A2 included in the conventional servo pattern 52A, and a more reliable servo signal can be obtained than the servo signal obtained from the conventional servo pattern 52A (hereinafter, this effect will also be referred to as the "first effect"). As shown in Figure 14, when the servo pattern 58B is read by the servo read element SR in a state where the magnetic head 28 is tilted upstream in the forward direction by an angle β (i.e., an angle β counterclockwise when viewed from the front side of the paper in Figure 14), an effect similar to the first effect (hereinafter, this effect will also be referred to as the "second effect").

[0220] However, if the positions of both ends of the linear magnetization region 60A1 and the positions of both ends of the linear magnetization region 60A2 are not aligned in the width direction WD, the servo read element SR will read one end of the linear magnetization region 60A1 but not one end of the linear magnetization region 60A2, or the servo read element SR will read the other end of the linear magnetization region 60A1 but not the other end of the linear magnetization region 60A2.

[0221] Therefore, in the magnetic tape MT according to this embodiment, the positions of both ends of the linear magnetized region 60A1 (i.e., the positions of both ends of each of the five magnetized straight lines 60A1a) and the positions of both ends of the linear magnetized region 60A2 (i.e., the positions of both ends of each of the five magnetized straight lines 60A2a) are aligned in the width direction WD within the servo band SB. Therefore, when the servo read element SR reads the servo pattern 58A, the servo read element SR can read the linear magnetized regions 60A1 and 60A2 without excess or deficiency, compared to when the positions of both ends of the linear magnetized region 60A1 and the positions of both ends of the linear magnetized region 60A2 are not aligned in the width direction WD. As a result, a more reliable servo signal can be obtained than when the positions of both ends of the linear magnetized region 60A1 and the positions of both ends of the linear magnetized region 60A2 are not aligned in the width direction WD (hereinafter, this effect will be referred to as the "third effect"). When the servo pattern 58B is read by the servo read element SR, an effect similar to the third effect (hereinafter, this effect will also be referred to as the "fourth effect") can be obtained.

[0222] 9 and 10 , even though the gradient of the linear magnetization region 60A1 with respect to the virtual line C1 is steeper than the gradient of the linear magnetization region 60A2 with respect to the virtual line C1, if the total length of the linear magnetization region 60A1 is made longer than the total length of the linear magnetization region 60A2, some parts will be read by the servo read element SR and some will not be read between the linear magnetization region 60A1 and the linear magnetization region 60A2. Also, even if the total length of the linear magnetization region 60B1 is made longer than the total length of the linear magnetization region 60B2, some parts will be read by the servo read element SR and some will not be read between the linear magnetization region 60B1 and the linear magnetization region 60B2. Therefore, in the magnetic tape MT according to this embodiment, the total length of the linear magnetized region 60A1 is shorter than the total length of the linear magnetized region 60A2, and the total length of the linear magnetized region 60B1 is longer than the total length of the linear magnetized region 60B2, thereby enabling the servo read element SR to read the linear magnetized regions 60A1 and 60A2, and the linear magnetized regions 60B1 and 60B2 without excess or deficiency (hereinafter, this effect will be referred to as the "fifth effect").

[0223] Furthermore, in the magnetic tape MT according to this embodiment, the linear magnetization region 60A1 is a set of five magnetization lines 60A1a, and the linear magnetization region 60A2 is a set of five magnetization lines 60A2a. Furthermore, the linear magnetization region 60B1 is a set of four magnetization lines 60B1a, and the linear magnetization region 60B2 is a set of four magnetization lines 60B2a. Therefore, compared to when each linear magnetization region is made up of a single magnetization line, the amount of information obtained from the servo pattern 58 can be increased, resulting in highly accurate servo control (hereinafter, this effect will be referred to as the "sixth effect").

[0224] Furthermore, in the magnetic tape MT according to this embodiment, the geometric characteristics of the linear magnetization region pair 60A on the magnetic tape MT correspond to the geometric characteristics obtained by aligning the ends of the virtual linear region 62A and the ends of the virtual linear region 62B in the width direction WD when the symmetry axis SA1 of the virtual linear region pair 62 is tilted relative to the virtual line C1, thereby tilting the entire virtual linear region pair 62 relative to the virtual line C1. Therefore, compared to when the servo read element SR reads a servo pattern 52A having a conventionally known geometric characteristic, the variation between the servo signals derived from the linear magnetization region 60A1 and the linear magnetization region 60A2 can be reduced. As a result, a servo signal with higher reliability can be obtained than a servo signal obtained from a servo pattern 52A having a conventionally known geometric characteristic (hereinafter, this effect will be referred to as the "seventh effect").

[0225] The linear magnetization region pair 60B differs from the linear magnetization region pair 60A only in that it has a linear magnetization region 60B1 instead of the linear magnetization region 60A1 and a linear magnetization region 60B2 instead of the linear magnetization region 60A2. The servo read element SR reads the linear magnetization region pair 60B configured in this manner, just like the linear magnetization region pair 60A. Therefore, the variation between the servo signals derived from the linear magnetization region 60B1 and the servo signals derived from the linear magnetization region 60B2 can be reduced compared to when the servo read element SR reads a servo pattern 52B having conventionally known geometric characteristics. As a result, a servo signal with higher reliability can be obtained than a servo signal obtained from a servo pattern 52B having conventionally known geometric characteristics (hereinafter, this effect will be referred to as the "eighth effect").

[0226] In this embodiment, a pair of corresponding servo patterns 58 between the servo bands SB are read by servo read elements SR1 and SR2 included in the magnetic head 28. Also, in this embodiment, the magnetic head 28 is used in a skewed state on the magnetic tape MT (see FIGS. 14 to 16 ). If the pair of corresponding servo patterns 58 between the servo bands SB were arranged without being shifted by a predetermined distance in the longitudinal direction LD of the magnetic tape MT, a time difference would occur between the timing at which one of the pair of corresponding servo patterns 58 between the servo bands SB is read and the timing at which the other servo pattern 58 is read. Therefore, in the magnetic tape MT according to this embodiment, the corresponding servo patterns 58 between the servo bands SB are shifted by a predetermined distance in the longitudinal direction LD of the magnetic tape MT between servo bands SB adjacent to each other in the width direction WD. This reduces the time difference between the timing at which one of a pair of corresponding servo patterns 58 between the servo bands SB is read and the timing at which the other servo pattern 58 is read, compared to when a pair of corresponding servo patterns 58 between adjacent servo bands SB in the width direction WD are arranged without any predetermined spacing between them (hereinafter, this effect will be referred to as the "ninth effect").

[0227] In this embodiment, the servo band SB is divided into a plurality of frames 56 (see FIGS. 9 and 12). Each frame 56 is defined based on a pair of servo patterns 58 (i.e., servo patterns 58A and 58B). In this embodiment, a pair of servo patterns 58 included in a pair of corresponding frames 56 between adjacent servo bands SB in the width direction WD are read by servo read elements SR1 and SR2 included in the magnetic head 28. In this embodiment, the magnetic head 28 is used in a skewed state on the magnetic tape MT (see FIGS. 14 to 16). If the pair of servo patterns 58 included in a pair of corresponding frames 56 between adjacent servo bands SB in the width direction WD were arranged without a predetermined interval offset in the longitudinal direction LD of the magnetic tape MT, a time difference would occur between the timing at which one of the pair of servo patterns 58 is read and the timing at which the other servo pattern 58 is read. Therefore, in the magnetic tape MT according to this embodiment, a pair of servo patterns 58 included in a pair of frames 56 that correspond to each other between adjacent servo bands SB in the width direction WD are shifted by a predetermined interval in the longitudinal direction LD of the magnetic tape MT between the adjacent servo bands SB in the width direction WD. This makes it possible to reduce the time difference between the timing at which one of the pair of servo patterns 58 included in a pair of frames 56 that correspond to each other between adjacent servo bands SB in the width direction WD is read and the timing at which the other servo pattern 58 is read, compared to when the corresponding pair of frames 56 are arranged without being shifted by the predetermined interval between the adjacent servo bands SB in the width direction WD (hereinafter, this effect will be referred to as the "tenth effect").

[0228] 12, in this embodiment, the predetermined interval is defined based on the angle α formed by the imaginary line C1 and the distance between adjacent servo bands SB in the width direction WD and frames 56 that do not correspond to each other, the servo band pitch, and the total length of the frames 56 in the longitudinal direction. That is, the predetermined interval is defined by and calculated from formula (1). Therefore, the predetermined interval can be obtained more easily than when the predetermined interval is defined without using the angle α, the servo band pitch, or the total length of the frames 56 in the longitudinal direction (hereinafter, this effect will be referred to as the "eleventh effect").

[0229] In this embodiment, the servo signal resulting from the servo read element SR reading the servo pattern 58 is detected using an autocorrelation coefficient (see FIG. 16). This allows the servo signal to be detected with higher accuracy than when the servo signal is detected using only a method of determining whether the signal level exceeds a threshold (hereinafter, this effect will be referred to as the "twelfth effect").

[0230] In this embodiment, servo bands SB are formed by alternately recording servo patterns 58A and 58B in strip-shaped regions 61 along the longitudinal direction LD. A virtual line C5 is set in the plurality of servo patterns 58 arranged in the longitudinal direction LD of servo bands SB. Virtual line C5 is set at a position where distance D1 is half distance D2. The width SWD of servo bands SB is set to a length where distances D3 and D4 are equal. Therefore, for example, by tilting virtual linear regions 62A and 62B by an angle a with respect to virtual line C1 around center O1 as the rotation axis, when insufficient and unnecessary portions occur, the width SWD of servo bands SB can be set to an appropriate length compared to simply compensating for the insufficient portions and trimming the unnecessary portions. As a result, servo control, skew angle control, and / or tension control, etc., can be performed with high precision (hereinafter, this effect will be referred to as the "thirteenth effect").

[0231] In this embodiment, the distance between positions P1 and P2 is distance D1, and the distance between positions P1 and P3 is distance D2. The imaginary line C5 is set at a position where distance D1 is half of distance D2, and the width SWD of the servo band SB is set to a length where distance D3 and distance D4 are equal. In this embodiment, position P1 is defined as the position where imaginary line C5 intersects with the magnetization line 60A1a located at one end of the longitudinal direction LD of all the magnetization lines 60A1a included in the linear magnetization region 60A1. Position P2 is defined as the position where imaginary line C5 intersects with the magnetization line 60A2a located at one end of the longitudinal direction LD of all the magnetization lines 60A2a included in the linear magnetization region 60A2. Furthermore, the position P3 is the position where the imaginary line C5 intersects with the magnetization line 60B1a at one end of the longitudinal direction LD among all the magnetization lines 60B1a included in the linear magnetization region 60B1. Thus, in the magnetic tape MT according to this embodiment, the width SWD of the servo band SB is set to an appropriate length compared to when a position randomly selected from the linear magnetization region 60A1 is set as position P1, a position randomly selected from the linear magnetization region 60A2 is set as position P2, and a position randomly obtained from the linear magnetization region 60B1 is set as position P3. Therefore, it is possible to realize highly accurate reading of the servo band SB by the servo read element SR (hereinafter, this effect will be referred to as the "fourteenth effect").

[0232] In this embodiment, the number of magnetization lines 60A1a and the number of magnetization lines 60A2a are the same, the number of magnetization lines 60A1a and the number of magnetization lines 60B1a are different, and the number of magnetization lines 60A2a and the number of magnetization lines 60B2a are different. Therefore, in the magnetic tape MT according to this embodiment, even if the number of magnetization lines 60A1a and the number of magnetization lines 60A2a are the same, the number of magnetization lines 60A1a and the number of magnetization lines 60B1a are different, and the number of magnetization lines 60A2a and the number of magnetization lines 60B2a are different, the width SWD of the servo band SB is set to an appropriate length. As a result, it is possible to achieve high-precision reading of the servo band SB by the servo read element SR (hereinafter, this effect will be referred to as the "fifteenth effect").

[0233] In this embodiment, the plurality of servo bands SB are formed at equal intervals along the width direction WD. Therefore, in the magnetic tape MT according to this embodiment, the width SWD of each of the plurality of servo bands SB is set to an appropriate length. As a result, the servo read element SR can read the servo bands SB with high accuracy (hereinafter, this effect will be referred to as the "sixteenth effect").

[0234] [Other Modifications] In the above embodiment, the magnetic tape system 10 is exemplified as one in which the magnetic tape cartridge 12 is freely insertable into and removable from the magnetic tape drive 14. However, the technology of the present disclosure is not limited to this. For example, the technology of the present disclosure can also be applied to a magnetic tape system in which at least one magnetic tape cartridge 12 is pre-loaded into the magnetic tape drive 14 (i.e., a magnetic tape system in which at least one magnetic tape cartridge 12 and the magnetic tape drive 14 are pre-integrated).

[0235] Although the above embodiment illustrates a single magnetic head 28, the technology of the present disclosure is not limited to this. For example, multiple magnetic heads 28 may be positioned above the magnetic tape MT. For example, a read magnetic head 28 and at least one write magnetic head 28 may be positioned above the magnetic tape MT. The read magnetic head 28 may be used to verify data recorded in the data band DB by the write magnetic head 28. Furthermore, one magnetic head equipped with a read magnetic element unit 42 and at least one write magnetic element unit 42 may be positioned above the magnetic tape MT.

[0236] The above-described description and illustrations are a detailed explanation of the parts related to the technology of the present disclosure and are merely an example of the technology of the present disclosure. For example, the above description of the configuration, functions, actions, and effects is an explanation of an example of the configuration, functions, actions, and effects of the parts related to the technology of the present disclosure. Therefore, it goes without saying that unnecessary parts may be deleted, new elements may be added, or replacements may be made to the above-described description and illustrations within the scope of the gist of the technology of the present disclosure. Furthermore, to avoid confusion and facilitate understanding of the parts related to the technology of the present disclosure, the above-described description and illustrations omit explanations of common technical knowledge that do not require particular explanation to enable the implementation of the technology of the present disclosure.

[0237] In this specification, "A and / or B" is synonymous with "at least one of A and B." In other words, "A and / or B" means that it may be only A, only B, or a combination of A and B. Furthermore, in this specification, the same concept as "A and / or B" is also applied when three or more things are expressed by connecting them with "and / or."

[0238] All publications, patent applications, and technical standards mentioned in this specification are herein incorporated by reference to the same extent as if each individual publication, patent application, or technical standard was specifically and individually indicated to be incorporated by reference.

Claims

1. A magnetic tape having a servo band, wherein a plurality of servo patterns are recorded on the servo band along the longitudinal direction of the magnetic tape, the servo pattern being at least one pair of linear magnetization regions, the pair of linear magnetization regions being a linearly magnetized first linear magnetization region and a linearly magnetized second linear magnetization region, the first linear magnetization region and the second linear magnetization region being inclined in opposite directions with respect to a first imaginary line along the width direction of the magnetic tape, the first linear magnetization region having a steeper inclination angle with respect to the first imaginary line than the second linear magnetization region, the positions of both ends of the first linear magnetization region and the positions of both ends of the second linear magnetization region are aligned with respect to the width direction of the magnetic tape, the servo band having first servo patterns and second servo patterns alternately arranged along the longitudinal direction as the plurality of servo patterns, and the plurality of servo patterns having an imaginary line set therein that crosses the plurality of servo patterns along the longitudinal direction, the first servo pattern has a first position and a second position where it intersects with the virtual line, the second servo pattern has a third position where it intersects with the virtual line, the first position is a position where the virtual line intersects with the first linear magnetization region of the first servo pattern, the second position is a position where the virtual line intersects with the second linear magnetization region of the first servo pattern, the third position is a position where the virtual line intersects with the first linear magnetization region of the second servo pattern, the virtual lines are set at positions where a relationship is established between the first servo pattern and the second servo pattern adjacent in the longitudinal direction, where the first distance being the distance between the first position and the second position is half of the second distance being the distance between the first position and the third position, and the width of the servo band is set to a length where the distance from the virtual line to one end of the servo band in the width direction is equal to the distance from the virtual line to the other end of the servo band in the width direction.

2. The magnetic tape of claim 1, wherein the first linear magnetization region is a collection of a plurality of first magnetization lines, the second linear magnetization region is a collection of a plurality of second magnetization lines, the first position is a position where a first magnetization line located at one end of the longitudinal direction of the plurality of first magnetization lines included in the first servo pattern on the virtual line intersects with the virtual line, the second position is a position where a second magnetization line located at one end of the longitudinal direction of the plurality of second magnetization lines included in the first servo pattern on the virtual line intersects with the virtual line, and the third position is a position where a first magnetization line located at one end of the longitudinal direction of the plurality of first magnetization lines included in the second servo pattern on the virtual line intersects with the virtual line.

3. The magnetic tape according to claim 2, wherein in the servo pattern, the number of the first magnetization lines and the number of the second magnetization lines are the same, the number of the first magnetization lines is different between the first servo pattern and the second servo pattern, and the number of the second magnetization lines is different between the first servo pattern and the second servo pattern.

4. The magnetic tape according to claim 1, wherein a plurality of said servo bands are formed at a predetermined pitch in said width direction.

5. A magnetic tape cartridge comprising the magnetic tape according to any one of claims 1 to 4 and a case in which the magnetic tape is housed.

6. A servo pattern recording device comprising: a pulse signal generator; and a servo pattern recording head, wherein the pulse signal generator generates a pulse signal; the servo pattern recording head has a gap pattern and records a plurality of servo patterns in a band-shaped area formed on the surface of a magnetic tape along the longitudinal direction of the magnetic tape by applying a magnetic field from the gap pattern in accordance with the pulse signal to the band-shaped area along the longitudinal direction of the magnetic tape; a servo band is formed by recording the plurality of servo patterns in the band-shaped area along the longitudinal direction; the gap pattern is at least one pair of straight line areas, wherein a first straight line area which is one of the pair of straight line areas and a second straight line area which is the other of the pair of straight line areas are inclined in opposite directions with respect to a second imaginary line which is aligned in a direction corresponding to the width direction of the magnetic tape on the surface; the first straight line area has a steeper inclination angle with respect to the second imaginary line than the second straight line area; and both ends of the first straight line area and the second straight line area are aligned in a direction corresponding to the width direction of the magnetic tape; the servo pattern is at least one pair of linear magnetization regions, the pair of linear magnetization regions being a linearly magnetized first linear magnetization region and a linearly magnetized second linear magnetization region, the first linear magnetization region and the second linear magnetization region are inclined in opposite directions with respect to a first imaginary line along the width direction of the magnetic tape, the first linear magnetization region has a steeper inclination angle with respect to the first imaginary line than the second linear magnetization region, both ends of the first linear magnetization region and both ends of the second linear magnetization region are aligned with each other in the width direction of the magnetic tape, the servo band has first servo patterns and second servo patterns alternately arranged along the longitudinal direction as the plurality of servo patterns, a virtual line is set in the plurality of servo patterns that crosses the plurality of servo patterns along the longitudinal direction, the first servo pattern has a first position and a second position that intersects with the virtual line, and the second servo pattern has a third position that intersects with the virtual line,a servo pattern recording device in which the first position is a position where the virtual line intersects with the first linear magnetization region of the first servo pattern, the second position is a position where the virtual line intersects with the second linear magnetization region of the first servo pattern, the third position is a position where the virtual line intersects with the first linear magnetization region of the second servo pattern, the virtual line is set at a position where a relationship is established between the first servo pattern and the second servo pattern adjacent in the longitudinal direction such that a first distance, which is a distance between the first position and the second position, is half of a second distance, which is a distance between the first position and the third position, and the width of the servo band is set to a length such that a distance from the virtual line to one end of the servo band in the width direction is equal to a distance from the virtual line to the other end of the servo band in the width direction.

7. The servo pattern recording device of claim 6, wherein the first linear magnetization region is a collection of a plurality of first magnetization lines, the second linear magnetization region is a collection of a plurality of second magnetization lines, the first position is a position where a first magnetization line located at one end of the longitudinal direction of the plurality of first magnetization lines included in the first servo pattern on the virtual line intersects with the virtual line, the second position is a position where a second magnetization line located at one end of the longitudinal direction of the plurality of second magnetization lines included in the first servo pattern on the virtual line intersects with the virtual line, and the third position is a position where a first magnetization line located at one end of the longitudinal direction of the plurality of first magnetization lines included in the second servo pattern on the virtual line intersects with the virtual line.

8. A servo pattern recording device according to claim 7, wherein in the servo pattern, the number of the first magnetization lines and the number of the second magnetization lines are the same, the number of the first magnetization lines is different between the first servo pattern and the second servo pattern, and the number of the second magnetization lines is different between the first servo pattern and the second servo pattern.

9. The servo pattern recording device according to claim 6, wherein a plurality of said servo bands are formed at a predetermined pitch in said width direction.

10. A magnetic tape drive comprising: a running mechanism for running the magnetic tape according to any one of claims 1 to 4 along a predetermined path; and a magnetic head having a plurality of servo read elements for reading the servo pattern on the predetermined path while the magnetic tape is running by said running mechanism, wherein the plurality of servo read elements are arranged along the longitudinal direction of the magnetic head, and the magnetic head is positioned with the longitudinal direction of the magnetic head inclined relative to the running direction of the magnetic tape.

11. A magnetic tape system comprising: a magnetic tape according to any one of claims 1 to 4; and a magnetic tape drive equipped with a magnetic head having a plurality of servo read elements that read the servo pattern on a predetermined path while the magnetic tape is running along the predetermined path, wherein the plurality of servo read elements are arranged along the longitudinal direction of the magnetic head, and the magnetic head is positioned such that the longitudinal direction of the magnetic head is inclined relative to the running direction of the magnetic tape.

12. A detection device comprising a processor, wherein the processor detects a servo signal resulting from reading the servo pattern from the magnetic tape according to any one of claims 1 to 4 by a servo read element, using an autocorrelation coefficient.

13. A method for recording a magnetic tape on a magnetic tape, comprising: generating a pulse signal; and using a servo pattern recording head having a gap pattern to record a plurality of servo patterns in a band-shaped area formed on the surface of the magnetic tape along the longitudinal direction of the magnetic tape by applying a magnetic field from the gap pattern in accordance with the pulse signal to the band-shaped area along the longitudinal direction of the magnetic tape, wherein a servo band is formed by recording the plurality of servo patterns in the band-shaped area along the longitudinal direction, the gap pattern being at least one pair of linear areas, a first linear area being one of the pair of linear areas and a second linear area being the other of the pair of linear areas being inclined in opposite directions with respect to a second imaginary line extending in a direction corresponding to the width direction of the magnetic tape on the surface, the first linear area having a steeper inclination angle with respect to the second imaginary line than the second linear area, and both ends of the first linear area and the second linear area being aligned in a direction corresponding to the width direction of the magnetic tape, the servo pattern being at least one pair of linear magnetized areas, the pair of linear magnetization regions is a linearly magnetized first linear magnetization region and a linearly magnetized second linear magnetization region, the first linear magnetization region and the second linear magnetization region are inclined in opposite directions with respect to a first imaginary line along the width direction of the magnetic tape, the first linear magnetization region has a steeper inclination angle with respect to the first imaginary line than the second linear magnetization region, both ends of the first linear magnetization region and both ends of the second linear magnetization region are aligned with each other in the width direction of the magnetic tape, the servo band has first servo patterns and second servo patterns alternately arranged along the longitudinal direction as the plurality of servo patterns, a virtual line is set in the plurality of servo patterns that crosses the plurality of servo patterns along the longitudinal direction, the first servo pattern has a first position and a second position that intersects with the virtual line, and the second servo pattern has a third position that intersects with the virtual line, the first position is a position where the virtual line intersects with the first linear magnetization region of the first servo pattern,a servo pattern recording method in which the second position is a position where the virtual line intersects with the second linear magnetization region of the first servo pattern, the third position is a position where the virtual line intersects with the first linear magnetization region of the second servo pattern, the virtual line is set at a position where a relationship is established between the first servo pattern and the second servo pattern adjacent in the longitudinal direction such that a first distance, which is a distance between the first position and the second position, is half of a second distance, which is a distance between the first position and the third position, and the width of the servo band is set to a length such that a distance from the virtual line to one end of the servo band in the width direction is equal to a distance from the virtual line to the other end of the servo band in the width direction.

14. A magnetic tape on which a plurality of servo patterns are recorded by the servo pattern recording device according to any one of claims 6 to 9.

15. A magnetic tape cartridge comprising the magnetic tape according to claim 14 and a case in which the magnetic tape is housed.

16. A magnetic tape drive comprising: a running mechanism for running the magnetic tape according to claim 14 along a predetermined path; and a magnetic head having a plurality of servo read elements for reading the servo pattern on the predetermined path while the magnetic tape is running by the running mechanism, wherein the plurality of servo read elements are arranged along the longitudinal direction of the magnetic head, and the magnetic head is positioned with the longitudinal direction of the magnetic head inclined relative to the running direction of the magnetic tape.

17. A magnetic tape system comprising: the magnetic tape according to claim 14; and a magnetic tape drive equipped with a magnetic head having a plurality of servo read elements that read the servo pattern on a predetermined path while the magnetic tape is running along the predetermined path, wherein the plurality of servo read elements are arranged along the longitudinal direction of the magnetic head, and the magnetic head is positioned such that the longitudinal direction of the magnetic head is inclined relative to the running direction of the magnetic tape.

18. A detection device comprising a processor, wherein the processor detects a servo signal resulting from reading the servo pattern from the magnetic tape according to claim 14 by a servo read element, using an autocorrelation coefficient.

19. A method for manufacturing a magnetic tape, comprising: recording a plurality of servo patterns on a magnetic tape according to the servo pattern recording method of claim 13; and winding up the magnetic tape.

20. An inspection device comprising: the detection device according to claim 12 or 18; and an inspection processor that inspects the servo bands on the magnetic tape in which the servo patterns are recorded, based on the servo signals detected by the detection device.

21. A detection method comprising detecting a servo signal resulting from reading the servo pattern from the magnetic tape according to any one of claims 1 to 4 and 14 by a servo read element, using an autocorrelation coefficient.

22. An inspection method comprising inspecting a servo band on the magnetic tape in which the servo pattern is recorded, based on a servo signal detected by the detection method according to claim 21.