Tape, tape cartridge, tape system, detection method, and tape manufacturing method

Abstract

The invention provides a magnetic tape in which an index indicating the non-linearity of a servo pattern is controlled to 15% or less of the track pitch. The track pitch is the pitch between the tracks. The index indicates a degree of deviation between the plurality of distance differences and an average value of the plurality of distance differences. The distance difference is a difference between a distance between a pair of first positions corresponding in the width direction in the pair of servo patterns and a distance between a pair of second positions offset in the width direction from the pair of first positions by a first predetermined interval in the pair of servo patterns. The plurality of distance differences are obtained by measuring the distance difference at each second predetermined interval along the width direction in the pair of servo patterns. The first predetermined interval is larger than the second predetermined interval.

Description

TECHNICAL FIELD

[0001] The technology of the present application relates to a magnetic tape, a magnetic tape cartridge, a magnetic tape system, a detection method, and a manufacturing method of a magnetic tape. BACKGROUND

[0002] In Japanese Patent Application Publication No. 2022-057517, a magnetic tape is disclosed, which has a time-based servo pattern, and is used in a magnetic tape device in which the total number of data tracks in terms of 1 / 2-inch width of the magnetic tape is 8705 or more, and the ΔPNL of the time-based servo pattern is 10.0% or less of the track pitch, the ΔPNL indicating an amount of deviation from straightness of the time-based servo pattern.

[0003] In Japanese Patent Application Publication No. 2019-046521, a recording device is disclosed, which is provided with a recording section that records information related to straightness of a servo signal recorded on a magnetic tape possessed by a recording magnetic tape cartridge, in a recording medium possessed by the recording magnetic tape cartridge.

[0004] In U.S. Patent Application Publication No. 2019 / 0279673, as a method of recording data on a magnetic tape, a shingled recording method is disclosed. SUMMARY

[0005] An embodiment of the technology of the present application provides a magnetic tape, a magnetic tape cartridge, a magnetic tape system, a detection method, and a manufacturing method of a magnetic tape, which can contribute to improving accuracy of recording data on a magnetic tape and accuracy of reproducing data recorded on a magnetic tape.

[0006] Means for solving technical problems

[0007] A first aspect of the present technology is a magnetic tape in which a plurality of servo bands each having a plurality of servo patterns recorded along a longitudinal direction are arranged in a width direction, wherein an index indicating a non-linearity of the servo patterns is controlled to be 15% or less of a track pitch, the track pitch being a pitch between a plurality of tracks formed by recording data on the magnetic tape by a recording element in accordance with a signal obtained from the plurality of servo patterns, the index indicating a degree of deviation between a plurality of PES difference gaps and an average value of the plurality of PES difference gaps, the PES difference gap being a difference between a first PES difference and a second PES difference, the first PES difference being a difference in PES between a pair of first positions corresponding in the width direction in a pair of servo patterns recorded between a pair of servo bands adjacent in the width direction among the plurality of servo bands and at positions corresponding in the width direction, the second PES difference being a difference in PES between a pair of second positions offset from the pair of first positions by a first predetermined interval in the width direction in the pair of servo patterns, the plurality of PES difference gaps being obtained by measuring the PES difference gap at every second predetermined interval in the width direction in the pair of servo patterns, the first predetermined interval being larger than the second predetermined interval.

[0008] A second aspect of the present technology is the magnetic tape according to the first aspect, wherein the plurality of tracks are formed by recording data on the magnetic tape by the recording element in an SMR manner.

[0009] A third aspect of the present technology is the magnetic tape according to the first aspect or the second aspect, wherein the index is a value corresponding to three times a standard deviation of the plurality of PES difference gaps.

[0010] A fourth aspect of the present technology is the magnetic tape according to any one of the first aspect to the third aspect, wherein the first predetermined interval is a reference interval closest to a natural number times the second predetermined interval and corresponds to half a difference between a recording element length, which is a length of the recording element in the width direction, and the track pitch.

[0011] A fifth aspect of the present technology is the magnetic tape according to any one of the first aspect to the third aspect, wherein the first predetermined interval is an interval corresponding to two or more times the second predetermined interval.

[0012] A sixth aspect of the present technology is the magnetic tape according to any one of the first aspect to the sixth aspect, wherein the first predetermined interval is larger than the track pitch.

[0013] A seventh aspect of the present technology is the magnetic tape according to any one of the first aspect to the sixth aspect, wherein the index is controlled to be 10% or less of the track pitch.

[0014] The eighth aspect of the present technology is the magnetic tape according to any one of the first to seventh aspects, in which the index is controlled to be equal to or less than 5% of the track pitch.

[0015] The ninth aspect of the present technology is the magnetic tape according to any one of the first to eighth aspects, in which, on the magnetic tape, three or more servo bands are arranged in the width direction as the plurality of servo bands, and the index is obtained for each of all pairs of servo bands adjacent in the width direction.

[0016] The tenth aspect of the present technology is the magnetic tape according to the ninth aspect, in which the index obtained for each of the pairs of servo bands is controlled to be equal to or less than 15% of the track pitch.

[0017] The eleventh aspect of the present technology is the magnetic tape according to the ninth aspect, in which the index obtained for each of the pairs of servo bands is controlled to be equal to or less than 10% of the track pitch.

[0018] The twelfth aspect of the present technology is the magnetic tape according to the ninth aspect, in which the index obtained for each of the pairs of servo bands is controlled to be equal to or less than 5% of the track pitch.

[0019] The thirteenth aspect of the present technology is the magnetic tape according to any one of the first to twelfth aspects, in which the servo pattern is at least one pair of linearly magnetized regions, the pair of linearly magnetized regions is a first linearly magnetized region linearly magnetized and a second linearly magnetized region linearly magnetized, the first linearly magnetized region and the second linearly magnetized region are inclined in opposite directions with respect to a virtual straight line along the width direction, and the first linearly magnetized region has a steeper inclination angle with respect to the virtual straight line than the second linearly magnetized region.

[0020] The fourteenth aspect of the present technology is a magnetic tape cartridge including: the magnetic tape according to any one of the first to thirteenth aspects; and a housing that accommodates the magnetic tape.

[0021] The fifteenth aspect of the present technology is a magnetic tape system including: the magnetic tape according to any one of the first to thirteenth aspects; and a magnetic head that records data on the magnetic tape and / or reproduces data recorded on the magnetic tape.

[0022] The sixteenth aspect of the present technology is a detection method including: a step of obtaining an index from the magnetic tape according to any one of the first to thirteenth aspects; and a step of detecting the magnetic tape using the index.

[0023] The 17th aspect of the present technology is the detection method according to the 16th aspect, wherein the detecting the magnetic tape includes detecting straightness of the servo pattern using the index.

[0024] The 18th aspect of the present technology is a manufacturing method of a magnetic tape in which a plurality of servo bands each of which has a plurality of servo patterns recorded along a first longitudinal direction are arranged along a width direction, the manufacturing method including: a step of disposing a servo write head in a posture in which a recording surface faces a plurality of gap patterns, the servo write head having: an opposing surface that faces the recording surface of the magnetic tape when recording the plurality of servo patterns along the first longitudinal direction; and the plurality of gap patterns formed at intervals along a second longitudinal direction of the opposing surface and each corresponding to the plurality of servo patterns; and a step of recording the plurality of servo patterns on the recording surface along the first longitudinal direction using the servo write head disposed in the posture, thereby forming the plurality of servo bands on the recording surface, an index indicating non-straightness of the servo pattern being controlled to be equal to or less than 15% of a track pitch, the track pitch being a pitch between a plurality of tracks formed by recording data on the magnetic tape by a recording element based on a signal obtained from the plurality of servo patterns, the index indicating a degree of deviation between a plurality of PES difference gaps and an average value of the plurality of PES difference gaps, the PES difference gap being a difference between a first PES difference and a second PES difference, the first PES difference being a difference in PES between a pair of first positions corresponding in the width direction in a pair of servo patterns recorded between a pair of servo bands adjacent in the width direction among the plurality of servo bands and at positions corresponding in the width direction, the second PES difference being a difference in PES between a pair of second positions offset from the pair of first positions by a first predetermined interval in the width direction in the pair of servo patterns, the plurality of PES difference gaps being obtained by measuring the PES difference gap at every second predetermined interval in the width direction in the pair of servo patterns, the first predetermined interval being larger than the second predetermined interval. BRIEF DESCRIPTION OF DRAWINGS

[0025] Fig. 1 is a conceptual diagram showing an example of the structure of a magnetic tape system.

[0026] Fig. 2 is a schematic perspective view showing an example of the appearance of a magnetic tape cartridge.

[0027] Fig. 3 is a schematic configuration diagram showing an example of the hardware structure of a magnetic tape drive.

[0028] Fig. 4 is a schematic perspective view showing an example of the manner in which a magnetic field is released from the lower side of a magnetic tape cartridge by a non-contact type read / write device.

[0029] Fig. 5is a conceptual diagram showing an example of a manner in which the magnetic head is located on the magnetic tape, as viewed from the surface side of the magnetic tape.

[0030] Fig. 6 is a conceptual diagram showing an example of a manner in which the magnetic head is located on the magnetic tape, as viewed from the surface side of the magnetic tape.

[0031] Fig. 7 is a conceptual diagram showing an example of a structure of a data track formed on the surface of the magnetic tape.

[0032] Fig. 8 is a conceptual diagram showing an example of a correspondence relationship between a data recording / reproducing element and a data track.

[0033] Fig. 9 is a conceptual diagram showing an example of a manner in which a servo pattern is read by a servo reading element.

[0034] Fig. 10 is a conceptual diagram showing an example of a manner in which a data track is formed by shifting and overlapping a plurality of divided data tracks along a second direction by recording data on the surface of the magnetic tape in an SMR manner.

[0035] Fig. 11 is a conceptual diagram showing an example of a manner in which a first recording module, a reproducing module, and a second recording module are provided on the magnetic head.

[0036] Fig. 12 is a conceptual diagram showing an example of a structure of a servo writer.

[0037] Fig. 13 is a conceptual diagram showing an example of a structure of a servo pattern recording head and a pulse signal generator included in the servo writer.

[0038] Fig. 14 is a flowchart showing an example of a flow of a straightness detection method used in a detection process included in a manufacturing method of the magnetic tape.

[0039] Fig. 15 is a conceptual diagram showing an example of a structure of a servo track formed on the magnetic tape.

[0040] Fig. 16 is a conceptual diagram showing an example of a manner in which a plurality of ΔdPES are measured from adjacent servo patterns.

[0041] Fig. 17 is a conceptual diagram showing an example of a straightness determination condition.

[0042] Fig. 18is a chart showing an example of a distribution of a plurality of dPES obtained from a magnetic tape manufactured without using a straightness judgment condition but by a conventionally known technique, and a distribution of a plurality of dPES obtained from a magnetic tape manufactured from a process in which a straightness of a servo pattern is judged to be within an allowable range using a straightness judgment condition.

[0043] Fig. 19 is a chart showing an example of a distribution of a plurality of ΔdPES obtained from a magnetic tape manufactured without using a straightness judgment condition but by a conventionally known technique, and a distribution of a plurality of ΔdPES obtained from a magnetic tape manufactured from a process in which a straightness of a servo pattern is judged to be within an allowable range using a straightness judgment condition.

[0044] Fig. 20A is a chart showing an example of a distribution of a plurality of ΔdPES obtained under a first condition shown in Table 1.

[0045] Fig. 20B is a chart showing an example of a distribution of a plurality of ΔdPES obtained under a second condition shown in Table 2.

[0046] Fig. 21 is a conceptual diagram showing an example of a manner of a first recording module when a first servo reading element reads a servo pattern through a path that is the most inward of a plurality of paths of a width of a magnetic tape used at the time of recording data.

[0047] Fig. 22 is a conceptual diagram showing an example of a manner when a plurality of first data recording elements in a first recording module respectively form one divided data track.

[0048] Fig. 23 is a conceptual diagram showing an example of a manner of a data track formed by a plurality of first data recording elements in a first recording module respectively shifting and overlapping a plurality of divided data tracks along a second direction.

[0049] Fig. 24 is a conceptual diagram showing an example of a manner of a reproduction module when a data reproducing element reproduces data from a divided data track that is located at the most inward of a width of a magnetic tape among a plurality of divided data tracks in which one data track is formed.

[0050] Fig. 25 is a conceptual diagram showing an example of a manner of a reproduction module when a data reproducing element reproduces data from a divided data track that is located at the most outward of a width of a magnetic tape among a plurality of divided data tracks in which one data track is formed.

[0051] Fig. 26is a conceptual diagram showing an example of a manner of showing a data track formed by a plurality of divided data tracks being shifted and overlapped along a first direction by a plurality of data recording elements in a recording module, respectively.

[0052] Fig. 27 is a conceptual diagram showing a modification example of a structure of a magnetic head.

[0053] Fig. 28 is a conceptual diagram showing a modification example of a structure of a servo pattern.

[0054] Fig. 29 is a conceptual diagram showing an example of a relationship between a geometric characteristic of an actual servo pattern and a geometric characteristic of a virtual servo pattern. DETAILED DESCRIPTION

[0055] Hereinafter, an example of an embodiment of a magnetic tape, a magnetic tape cartridge, a magnetic tape system, a detection method, and a manufacturing method of a magnetic tape, to which the technology of the present application pertains, will be described with reference to the drawings.

[0056] First, statements used in the following description will be described.

[0057] CPU refers to the abbreviation of "Central Processing Unit". RAM refers to the abbreviation of "Random Access Memory". NVM refers to the abbreviation of "Non-Volatile Memory". EEPROM refers to the abbreviation of "Electrically Erasable and Programmable Read Only Memory". SSD refers to the abbreviation of "Solid State Drive". HDD refers to the abbreviation of "Hard Disk Drive". ASIC refers to the abbreviation of "Application Specific Integrated Circuit". PLD refers to the abbreviation of "Programmable Logic Device". FPGA refers to the abbreviation of "Field-Programmable Gate Array". SoC refers to the abbreviation of "System-on-a-Chip". IC refers to the abbreviation of "Integrated Circuit". RFID refers to the abbreviation of "Radio Frequency Identifier". UI refers to the abbreviation of "User Interface". SMR refers to the abbreviation of "Shingled Magnetic Recording". TDS refers to the abbreviation of "Transverse Dimensional Stability". "FIB" refers to the abbreviation of "Focused Ion Beam". PES refers to the abbreviation of "Position Error Signal". MEMS refers to the abbreviation of "Micro Electro Mechanical Systems". PVD refers to the abbreviation of "Physical Vapor Deposition". CVD refers to the abbreviation of "Chemical Vapor Deposition".

[0058] As an example, as Fig. 1As shown, the tape system 10 is provided with a tape cartridge 12 and a tape drive 14. The tape cartridge 12 is loaded into the tape drive 14. The tape cartridge 12 houses a magnetic tape MT. The tape drive 14 pulls out the magnetic tape MT from the loaded tape cartridge 12, runs the pulled-out magnetic tape MT, and records data on the magnetic tape MT or reads data from the magnetic tape MT.

[0059] In addition, in Fig. 1 In the example shown, the tape cartridge 12 and the tape drive 14 are shown separately for the sake of understanding the technology of the present application, but in fact, the tape system 10 is provided with a plurality of tape cartridges 12 and a plurality of tape drives 14. Then, the plurality of tape cartridges 12 and the plurality of tape drives 14 are selectively used. For example, a tape cartridge 12 is selected from the plurality of tape cartridges 12 in accordance with a given command, and the selected tape cartridge 12 is loaded into a designated tape drive 14 among the plurality of tape drives 14.

[0060] In the present embodiment, the tape system 10 is an example of the "tape system" to which the technology of the present application is applied. Also, in the present embodiment, the magnetic tape MT is an example of the "magnetic tape" to which the technology of the present application is applied. Also, in the present embodiment, the tape cartridge 12 is an example of the "tape cartridge" to which the technology of the present application is applied.

[0061] Next, reference Figs. 2-4 An example of the structure of the tape cartridge 12 will be described. Also, in the following description, for the sake of explanation, in Figs. 2-4 In the following description of the structure, the direction in which the tape cartridge 12 is loaded into the tape drive 14 is indicated by an arrow A, and the arrow A direction is set as the front direction of the tape cartridge 12, and the front direction side of the tape cartridge 12 is set as the front side of the tape cartridge 12. In the following description of the structure, "front" means the front side of the tape cartridge 12.

[0062] Also, in the following description, for the sake of explanation, in Figs. 2-4 In the following description of the structure, the direction orthogonal to the arrow A direction is set as the right direction of the tape cartridge 12, and the right direction side of the tape cartridge 12 is set as the right side of the tape cartridge 12. In the following description of the structure, "right" means the right side of the tape cartridge 12.

[0063] Also, in the following description, for the sake of explanation, in Figs. 2-4 In the following description of the structure, the direction opposite to the arrow B direction is set as the left direction of the tape cartridge 12, and the left direction side of the tape cartridge 12 is set as the left side of the tape cartridge 12. In the following description of the structure, "left" means the left side of the tape cartridge 12.

[0064] Also, in the following description, for the sake of explanation, in Figs. 2-4In the following description of the structure, "front" means the front side of the tape cartridge 12.

[0065] In the following description, for the sake of convenience of explanation, in Figs. 2-4 In the following description of the structure, "front" means the front side of the tape cartridge 12.

[0066] In the following description, for the sake of convenience of explanation, in Figs. 2-4 In the following description of the structure, "front" means the front side of the tape cartridge 12.

[0067] As an example, as shown in Fig. 2 The tape cartridge 12 has a substantially rectangular shape in plan view, and has a box-shaped casing 16. In the casing 16, a magnetic tape MT is accommodated. The casing 16 is an example of the "casing" to which the technology of the present application pertains.

[0068] A supply reel 22 is rotatably accommodated in the inside of the casing 16. The magnetic tape MT is wound around the supply reel 22. An opening 16A1 is formed in the front side of a right wall 16A of the casing 16. The magnetic tape MT is pulled out from the opening 16A1.

[0069] In the casing 16, a cartridge memory 24 is accommodated as a storage medium other than the magnetic tape MT. An IC chip having an NVM is mounted on the cartridge memory 24. In the present embodiment, a so-called passive RFID tag is adopted as the cartridge memory 24, and the cartridge memory 24 is subjected to reading and writing (that is, storage and acquisition) of various information in a non-contact manner.

[0070] In the cartridge memory 24, management information 15 for managing the tape cartridge 12 is stored. For example, in the management information 15, information related to the cartridge memory 24, information related to the magnetic tape MT, information related to the tape system 10, and information related to the tape drive 14 are included.

[0071] As an example, as shown in Fig. 3As shown, the tape drive 14 is provided with a controller 25, a transport device 26, a magnetic head 28, and a UI system device 29. The controller 25 is provided with a processing device 30 and a storage device 32. In the present embodiment, the magnetic head 28 is an example of the "magnetic head" to which the technology of the present application is applied.

[0072] The tape cartridge 12 is loaded into the tape drive 14 in the direction of the arrow A. In the tape drive 14, the tape MT is pulled out from the tape cartridge 12 and used. The tape drive 14 controls each part in the tape cartridge 12 and the tape drive 14 using the management information 15 and the like stored in the cartridge memory 24.

[0073] The tape drive 14 performs a magnetic process on the surface 31 of the tape MT using the magnetic head 28 in a state in which the tape MT is threaded. The surface 31 is a recording surface on which data is recorded. The magnetic process refers to a recording process in which the magnetic head 28 records data on the surface 31 of the tape MT having a magnetic layer, and a reproducing process in which the magnetic head 28 reproduces data from the surface 31 of the tape MT (i.e., a process of reading data). In the present embodiment, the tape drive 14 selectively performs the recording process and the reproducing process using the magnetic head 28. That is, the tape drive 14 pulls out the tape MT from the tape cartridge 12, performs a recording of data on the surface 31 of the pulled-out tape MT using the magnetic head 28, or performs a reproduction of data from the surface 31 of the pulled-out tape MT using the magnetic head 28. In the present embodiment, the surface 31 is an example of the "recording surface" to which the technology of the present application is applied.

[0074] The processing device 30 controls the entire tape drive 14. In the present embodiment, the processing device 30 is implemented by an ASIC, but the technology of the present application is not limited thereto. For example, the processing device 30 can also be implemented by an FPGA and / or a PLD. Also, the processing device 30 can also be implemented by a computer including a CPU, a flash memory (for example, an EEPROM and / or an SSD, and the like), and a RAM. Also, it can be implemented by combining two or more of the ASIC, the FPGA, the PLD, and the computer. That is, the processing device 30 can also be implemented by a combination of a hardware structure and a software structure.

[0075] The storage device 32 is connected to the processing device 30, and the processing device 30 writes various information to the storage device 32 and reads various information from the storage device 32. As an example of the storage device 32, a flash memory and / or an HDD can be cited. The flash memory and the HDD are merely examples, and any memory can be used as long as it is a nonvolatile memory that can be mounted on the tape drive 14.

[0076] The UI system device 29 is a device having a reception function of receiving a command signal representing a command from a user, and a presentation function of presenting information to the user. The reception function is realized by, for example, a touch panel, a hard key (e.g., a keyboard), and / or a mouse, etc. The presentation function is realized by, for example, a display, a printer, and / or a speaker, etc. The UI system device 29 is connected to the processing device 30. The processing device 30 acquires the command signal received by the UI system device 29. The UI system device 29 presents various information to the user under the control of the processing device 30.

[0077] The transport device 26 is a device that selectively transports the magnetic tape MT in a forward direction and a reverse direction along a predetermined path, and is provided with a feed motor 36, a take-up reel 38, a take-up motor 40, and a plurality of guide rollers GR. Here, the forward direction refers to a direction in which the magnetic tape MT is fed, and the reverse direction refers to a direction in which the magnetic tape MT is taken up.

[0078] The feed motor 36 rotates the supply reel 22 in the tape cassette 12 under the control of the processing device 30. The processing device 30 controls the rotation direction, rotation speed, and rotation torque of the supply reel 22 by controlling the feed motor 36.

[0079] The take-up motor 40 rotates the take-up reel 38 under the control of the processing device 30. The processing device 30 controls the rotation direction, rotation speed, and rotation torque of the take-up reel 38 by controlling the take-up motor 40.

[0080] In a case where the magnetic tape MT is taken up by the take-up reel 38, the processing device 30 rotates the feed motor 36 and the take-up motor 40 to cause the magnetic tape MT to run in the forward direction along the predetermined path. The rotation speed and rotation torque of the feed motor 36 and the take-up motor 40 are adjusted in accordance with the speed at which the magnetic tape MT is taken up by the take-up reel 38. Also, the rotation speed and rotation torque of the feed motor 36 and the take-up motor 40 are adjusted by the processing device 30, whereby tension is imparted to the magnetic tape MT. Also, the tension imparted to the magnetic tape MT is controlled by the processing device 30 adjusting the rotation speed and rotation torque of the feed motor 36 and the take-up motor 40.

[0081] In a case where the magnetic tape MT is taken up by the take-up reel 38, the processing device 30 rotates the feed motor 36 and the take-up motor 40 to cause the magnetic tape MT to run in the forward direction along the predetermined path. The rotation speed and rotation torque of the feed motor 36 and the take-up motor 40 are adjusted in accordance with the speed at which the magnetic tape MT is taken up by the take-up reel 38. Also, the rotation speed and rotation torque of the feed motor 36 and the take-up motor 40 are adjusted by the processing device 30, whereby tension is imparted to the magnetic tape MT. Also, the tension imparted to the magnetic tape MT is controlled by the processing device 30 adjusting the rotation speed and rotation torque of the feed motor 36 and the take-up motor 40.

[0082] The plurality of guide rollers GR are rollers that guide the magnetic tape MT. The predetermined path, i.e., the running path of the magnetic tape MT, is determined by the plurality of guide rollers GR being arranged separately across the position of the magnetic head 28 between the tape cassette 12 and the take-up reel 38.

[0083] The magnetic head 28 has a magnetic element unit 42 and a holder 44. The magnetic element unit 42 is held by the holder 44 to contact the magnetic tape MT in the running direction. The magnetic element unit 42 has a plurality of magnetic elements.

[0084] The magnetic element unit 42 records data on the magnetic tape MT transported by the transport device 26, or reproduces data from the magnetic tape MT transported by the transport device 26. Here, the data refers to, for example, the servo pattern 52 (refer to Fig. 6 ) and data other than the servo pattern 52 (i.e., data recorded on the data band DB (refer to Fig. 6 ).

[0085] The tape drive 14 has a non-contact read / write device 46. The non-contact read / write device 46 is disposed so as to be directly opposite the back surface of the cartridge memory 24 on the lower side of the tape cartridge 12 in a state where the tape cartridge 12 is loaded, and performs read / write of information to the cartridge memory 24 in a non-contact manner.

[0086] As an example, as shown in Fig. 4 , the non-contact read / write device 46 releases a magnetic field MF from the lower side of the tape cartridge 12 to the cartridge memory 24. The magnetic field MF penetrates the cartridge memory 24.

[0087] The non-contact read / write device 46 is connected to the processing device 30. The processing 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 processing device 30, and releases the generated magnetic field MF to the cartridge memory 24.

[0088] The non-contact read / write device 46 performs non-contact communication between the cartridge memory 24 via the magnetic field MF, and thereby performs processing corresponding to the control signal to the cartridge memory 24. For example, the non-contact read / write device 46 selectively performs processing of reading information from the cartridge memory 24 and processing of storing information to the cartridge memory 24 (i.e., processing of writing information to the cartridge memory 24) under the control of the processing device 30. In other words, the processing device 30 communicates with the cartridge memory 24 in a non-contact manner via the non-contact read / write device 46, and thereby reads information from the cartridge memory 24 or stores information to the cartridge memory 24.

[0089] As an example, as shown in Fig. 5 , the processing device 30 is connected to the magnetic head 28, and controls the use of the magnetic field MF generated by the magnetic head 28 (refer to Fig. 4) is controlled. The magnetic tape drive 14 is provided with a moving mechanism 48. The processing device 30 is connected to the magnetic head 28 via the moving mechanism 48. The processing device 30 controls movement of the magnetic head 28 (e.g., movement of the magnetic tape MT in the width direction WD (refer to Fig. 6 ) on the magnetic tape MT) via the moving mechanism 48.

[0090] The moving mechanism 48 has a moving actuator 48A. As the moving actuator 48A, for example, a voice coil motor and / or a piezoelectric actuator can be cited. The moving actuator 48A is connected to the processing device 30, and the processing device 30 controls the moving actuator 48A. Under the control of the processing device 30, the moving actuator 48A generates a motive force. The moving mechanism 48 moves the magnetic head 28 along the width direction WD (refer to Fig. 6 ) of the magnetic tape MT by receiving the motive force generated by the moving actuator 48A.

[0091] As an example, as shown in Fig. 6 , on the surface 31 of the magnetic tape MT, the servo bands SB1, SB2, and SB3 and the data bands DB1 and DB2 are formed. In the present embodiment, the servo bands SB1, SB2, and SB3 are an example of the "a plurality of servo bands" to which the technology of the present application pertains. Further, hereinafter, in order to facilitate explanation, 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" without particular distinction.

[0092] The servo bands SB1 to SB3 and the data bands DB1 and DB2 are formed along the long side direction LD (i.e., the total length direction) of the magnetic tape MT. Here, in other words, the long side direction LD refers to the tape running direction of the magnetic tape MT. The tape running direction of the magnetic tape MT is defined by two directions, i.e., the forward direction (hereinafter, also simply referred to as the "forward direction") in which the magnetic tape MT runs from the supply reel 22 side to the take-up reel 38 side, and the reverse direction (hereinafter, also simply referred to as the "reverse direction") in which the magnetic tape MT runs from the take-up reel 38 side to the supply reel 22 side. In the present embodiment, the long side direction LD is an example of the "long side direction" and the "first long side direction" to which the technology of the present application pertains.

[0093] The servo bands SB1 to SB3 are arranged at positions apart from each other in the width direction WD (hereinafter, also simply referred to as the "width direction WD") of the magnetic tape MT. For example, the servo bands SB1 to SB3 are arranged at equal intervals along the width direction WD. Further, in the present embodiment, the "equal intervals" refers to equal intervals in the meaning including an error within a range that is generally allowed in the technical field to which the technology of the present application pertains and does not depart from the technical spirit of the present application, in addition to complete equal intervals. Furthermore, in the present embodiment, the width direction WD is an example of the "width direction" to which the technology of the present application pertains.

[0094] The data band DB1 is provided between the servo bands SB1 and SB2, and the data band DB2 is provided between the servo bands SB2 and SB3. That is, the servo bands SB and the data bands DB are alternately arranged along the width direction WD.

[0095] In addition, in Fig. 6 In the example shown, three servo bands SB and two data bands DB are shown for ease of explanation (for easy understanding of the technology of the present application), but this is only an example, and two servo bands SB and one data band DB can also be used, and even if four or more servo bands SB and three or more data bands DB are used, the technology of the present application still holds.

[0096] On the servo band SB, a plurality of servo patterns 52 are recorded along the long direction LD. The servo patterns 52 can be divided into servo pattern 52A and servo pattern 52B. The plurality of servo patterns 52 are arranged at a prescribed interval along the long direction LD. In the present embodiment, "prescribed" means prescribed in the sense that it includes an error that is generally allowed in the technical field to which the technology of the present application belongs and does not depart from the gist of the technology of the present application, in addition to being completely prescribed.

[0097] The servo band SB is divided into a plurality of frames 50 along the long direction LD. The frame 50 is defined by a group of servo patterns 52. In Fig. 6 In the example shown, as an example of a group of servo patterns 52, servo pattern 52A and 52B are shown. The servo patterns 52A and 52B are adjacent along the long direction LD, 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.

[0098] The servo pattern 52 is composed of a pair of linear magnetization regions 54. The pair of linear magnetization regions 54 can be divided into a pair of linear magnetization regions 54A and a pair of linear magnetization regions 54B.

[0099] The servo pattern 52A is composed of the pair of linear magnetization regions 54A. In Fig. 6 In the example shown, as an example of the pair of linear magnetization regions 54A, a pair of regions composed of linear magnetization regions 54A1 and 54A2 is shown. The linear magnetization regions 54A1 and 54A2 are regions that are magnetized in a linear shape, respectively.

[0100] The linear magnetization regions 54A1 and 54A2 are inclined in opposite directions with respect to a virtual straight line extending along the width direction WD, that is, a virtual straight line Cl. In Fig. 6In the illustrated example, the linear magnetization regions 54A1 and 54A2 are inclined in a line-symmetrical manner with respect to the virtual straight line Cl. If explained more specifically, the linear magnetization regions 54A1 and 54A2 are not parallel to each other, and are formed in a state of being inclined at a predetermined angle (for example, 5 degrees) in opposite directions to the long side direction LD side with the virtual straight line Cl as a symmetric axis.

[0101] The linear magnetization region 54A1 is a collection of five magnetized straight lines, that is, magnetized straight lines 54A1a. The linear magnetization region 54A2 is a collection of five magnetized straight lines, that is, magnetized straight lines 54A2a.

[0102] The servo pattern 52B is constituted by a pair of linear magnetization regions 54B. In the illustrated example, the servo pattern 52B is constituted by a pair of linear magnetization regions 54B1 and 54B2. Fig. 6 In the illustrated example, as an example of the pair of linear magnetization regions 54B, a pair of regions constituted by the linear magnetization regions 54B1 and 54B2 is shown. The linear magnetization regions 54B1 and 54B2 are regions each of which is magnetized in a linear manner.

[0103] The linear magnetization regions 54B1 and 54B2 are inclined in opposite directions with respect to a virtual straight line, that is, a virtual straight line C2 extending along the width direction WD. In the illustrated example, the linear magnetization regions 54B1 and 54B2 are inclined in a line-symmetrical manner with respect to the virtual straight line C2. If explained more specifically, the linear magnetization regions 54B1 and 54B2 are not parallel to each other, and are formed in a state of being inclined at a predetermined angle (for example, 5 degrees) in opposite directions to the long side direction LD side with the virtual straight line C2 as a symmetric axis. Fig. 6 In the illustrated example, as an example of the pair of linear magnetization regions 54B, a pair of regions constituted by the linear magnetization regions 54B1 and 54B2 is shown. The linear magnetization regions 54B1 and 54B2 are regions each of which is magnetized in a linear manner.

[0104] The linear magnetization region 54B1 is a collection of four magnetized straight lines, that is, magnetized straight lines 54B1a. The linear magnetization region 54B2 is a collection of four magnetized straight lines, that is, magnetized straight lines 54B2a.

[0105] On the surface 31 side of the magnetic tape MT thus constituted, the magnetic head 28 is disposed. The holder 44 is formed in a cuboid shape, and is disposed so as to straddle the surface 31 of the magnetic tape MT along the width direction WD. The plurality of magnetic elements of the magnetic element unit 42 are arranged in a linear manner along the long side direction of the holder 44. The magnetic element unit 42 has a pair of servo reading elements SR and a plurality of data recording / reproducing elements DRW as the plurality of magnetic elements.

[0106] The length of the long side direction of the holder 44 is sufficiently long with respect to the width of the magnetic tape MT. For example, the length of the long side direction of the holder 44 is set to be longer than the length of the width of the magnetic tape MT, even if the magnetic element unit 42 is disposed at any position on the magnetic tape MT.

[0107] On the magnetic head 28, a pair of servo reading elements SR is mounted. In the magnetic head 28, the positional relationship of the holder 44 to the pair of servo reading elements SR is fixed. The pair of servo reading elements SR is composed of a servo reading element SR1 and a servo reading element SR2. The servo reading element SR1 is disposed at one end of the magnetic element unit 42, and the servo reading element SR2 is disposed at the other end of the magnetic element unit 42. In Fig. 6 In the example shown, the servo reading element SR1 is disposed at a position corresponding to the servo band SB3, and the servo reading element SR2 is disposed at a position corresponding to the servo band SB2.

[0108] The plurality of data recording / reproducing elements DRW is disposed in a straight line between the servo reading element SR1 and the servo reading element SR2. The plurality of data recording / reproducing elements DRW is disposed at intervals along the long direction of the magnetic head 28 (for example, at equal intervals along the long direction of the magnetic head 28). In Fig. 6 In the example shown, the long direction of the magnetic head 28, that is, the long direction of the holder 44 coincides with the width direction WD. Also, in Fig. 6 In the example shown, the plurality of data recording / reproducing elements DRW is disposed at a position corresponding to the data band DB2.

[0109] The processing device 30 acquires a servo pattern signal which is the result of reading the servo pattern 52 by the servo reading element SR, and performs servo control based on the acquired servo pattern signal. In the present embodiment, the servo pattern signal is an example of the "signal" to which the technology of the present application pertains.

[0110] Here, the servo control refers to control in which the moving mechanism 48 is caused to act so that the magnetic head 28 is moved in the width direction WD of the magnetic tape MT based on the servo pattern 52 read by the servo reading element SR.

[0111] By performing the servo control, the plurality of data recording / reproducing elements DRW is positioned on a designated region within the data band DB, and in this state, the designated region within the data band DB is subjected to magnetic processing. In Fig. 6 In the example shown, the designated region within the data band DB2 is subjected to magnetic processing by the plurality of data recording / reproducing elements DRW.

[0112] Also, in the case where the data band DB which is the read target of the data of the magnetic element unit 42 is changed (in the case where the data band DB is switched from the data band DB1 to the data band DB2, for example), the servo pattern 52 is read by the servo reading element SR, and the servo control is performed based on the servo pattern signal acquired as a result of the reading. Fig. 6In the example shown, in the case where the data tape DB as the data of the magnetic element unit 42 changes from the data tape DB2 to the data tape DB1), the moving mechanism 48 moves the magnetic head 28 in the width direction WD under the control of the processing device 30, thereby changing the positions of the pair of servo reading elements SR. That is, the moving mechanism 48 moves the servo reading element SR1 to a position corresponding to the servo tape SB2 and moves the servo reading element SR2 to a position corresponding to the servo tape SB1 by moving the magnetic head 28 in the width direction WD. Thereby, the positions of the plurality of data recording / reproducing elements DRW change from the data tape DB2 to the data tape DB1, and the data tape DB1 is subjected to the magnetic processing by the plurality of data recording / reproducing elements DRW.

[0113] As an example, as shown in FIG. 2, the data tape DB2 has the servo tape SB1 and the servo tape SB2 formed on the data tape DB2. The servo tape SB1 and the servo tape SB2 are formed by dividing the data tape DB2 in the width direction WD. Fig. 7 As shown in FIG. 3, on the data tape DB2, as a plurality of divided regions obtained by dividing the data tape DB2 in the width direction WD, from the servo tape SB2 side to the servo tape SB3 side, the data tracks DT1, DT2, DT3, DT4, DT5, DT6, DT7, and DT8 are formed.

[0114] The magnetic head 28 has the data recording / reproducing elements DRW1, DRW2, DRW3, DRW4, DRW5, DRW6, DRW7, and DRW8 between the servo reading element SR1 and the servo reading element SR2 in the width direction WD as the plurality of data recording / reproducing elements DRW. The data recording / reproducing elements DRW1 to DRW8 correspond one-to-one to the data tracks DT1 to DT8, and can reproduce data from the data tracks DT1 to DT8 (i.e., read) and record data to the data tracks DT1 to DT8 (i.e., write).

[0115] Hereinafter, the data tracks DT1, DT2, DT3, DT4, DT5, DT6, DT7, and DT8 will be described as "data tracks DT" without particular distinction. Also, hereinafter, the data recording / reproducing elements DRW1, DRW2, DRW3, DRW4, DRW5, DRW6, DRW7, and DRW8 will be described as "data recording / reproducing elements DRW" without particular distinction.

[0116] In addition, although not shown, on the data tape DB1 (refer to FIG. 1), a plurality of data tracks DT corresponding to the data tracks DT1, DT2, DT3, DT4, DT5, DT6, DT7, and DT8 are also formed. Fig. 6

[0117] As an example, as shown in FIG. 2, the data tape DB2 has the servo tape SB1 and the servo tape SB2 formed on the data tape DB2. The servo tape SB1 and the servo tape SB2 are formed by dividing the data tape DB2 in the width direction WD. Fig. 8 ​As shown, the data tracks DT have divided data track groups DTG. The data tracks DT1 to DT8 correspond to the divided data track groups DTG1 to DTG8. Hereinafter, the divided data track groups DTG1 to DTG8 are expressed as "divided data track groups DTG" without particularly distinguishing the explanation.

[0118] The divided data track group DTG1 is a collection of a plurality of divided data tracks obtained by dividing the data track DT in the width direction WD. Fig. 8 In the example shown, as an example of the divided data track group DTG1, divided data tracks DT_1, DT_2, DT_3, DT_4,..., DT_11, and DT_12 obtained by equally dividing the data track DT in the width direction WD are shown. The data recording / reproducing element DRW1 is responsible for the magnetic processing of the divided data track group DTG1. That is, the data recording / reproducing element DRW1 is responsible for the recording of data on the divided data tracks DT_1, DT_2, DT_3, DT_4,..., DT_11, and DT_12 and the reproduction of data from the divided data tracks DT_1, DT_2, DT_3, DT_4,..., DT_11, and DT_12. Hereinafter, in the case where it is not necessary to distinguish the divided data tracks DT_1, DT_2, DT_3, DT_4,..., DT_11, and DT_12, they are referred to as "divided data tracks DT_N".

[0119] The data recording / reproducing elements DRW2 to DRW8 are also responsible for the magnetic processing of the divided data track groups DTG of the data tracks DT corresponding to the respective data recording / reproducing elements DRW in the same manner as the data recording / reproducing element DRW1.

[0120] The data recording / reproducing element DRW moves to a position corresponding to a specified one of the plurality of data tracks DT as the magnetic head 28 is moved in the width direction WD (i.e., movement in the longitudinal direction of the magnetic head 28) by the moving mechanism 48 (see Fig. 6 ). Fig. 6 Fig. 7 The data recording / reproducing element DRW stays at a position corresponding to the specified one data track DT by servo control using the servo pattern 52 (see

[0121] As an example, as shown in Fig. 9 , in the servo pattern 52, paths P1 to P12 are allocated at equal intervals in the width direction WD. The paths P1 to P12 correspond to the plurality of divided data tracks DT_N included in the divided data track group DTG (in the example shown, the divided data tracks DT_1 to DT_12). Fig. 8 Fig. 9 ​​In the example shown, twelve divided data tracks (DT_N) are associated. Paths P1 to P12 are broadly divided into paths Pa1 to Pa12 used for recording data and paths Pb1 to Pb12 used for reproducing data. Hereinafter, paths P1 to P12 will be referred to as "path P" unless otherwise specified.

[0122] When the data recording / reproducing element DRW magnetically processes a divided data track DT_N designated as a target for magnetic processing, i.e., the target divided data track, the moving mechanism 48 moves the magnetic head 28 in the width direction WD so that the servo read element SR passes along a path P corresponding to the target divided data track. For example, when the data recording / reproducing element DRW magnetically processes the divided data track DT_1, the moving mechanism 48 moves the magnetic head 28 in the width direction WD so that the servo read element SR passes along path P1. Furthermore, when the data recording / reproducing element DRW magnetically processes the divided data track DT_12, the moving mechanism 48 moves the magnetic head 28 in the width direction WD so that the servo read element SR passes along path P12. As a result, the data recording / reproducing element DRW1 is aligned with the target divided data track, enabling magnetic processing of the target divided data track.

[0123] As an example, Fig. 10 As shown, all the divided data tracks DT_N (here, as an example, 12 divided data tracks DT_N) forming one data track DT are formed by recording data on the magnetic tape MT using the SMR method using the data recording / reproducing element DRW. The SMR method is a magnetic recording method for achieving high data density on the magnetic tape MT and is also called a shingled recording method.

[0124] exist Fig. 10 In the example shown, the width direction WD is defined by a first direction WD1, which is the direction along one end of the width of the magnetic tape MT, and a second direction WD2, which is the direction along the other end of the width of the magnetic tape MT. The second direction WD2 is the direction in which data is shifted on the magnetic tape MT by recording data on the magnetic tape MT using the SMR method. The multiple divided data tracks DT_N of each data track DT are recorded on the magnetic tape MT in an overlapping manner while being shifted along the second direction WD2. For a single data track DT, adjacent divided data tracks DT_N in the width direction WD are offset by a predetermined pitch Tp along the width direction WD.

[0125] In this embodiment, the multiple divided data tracks DT_N of each data track DT are an example of "multiple tracks" involved in the technology of the present invention. Also, in this embodiment, the pitch Tp is an example of "track pitch" involved in the technology of the present invention. Fig. 10In the illustrated example, the divided data tracks DT_1 to DT_12 are intentionally illustrated as being offset in the longitudinal direction LD for easy understanding of the arrangement relationship of the divided data tracks DT_1 to DT_12, but in actuality, the divided data tracks DT_1 to DT_12 are not offset in the longitudinal direction LD from each other, and the divided data tracks DT_1 to DT_12 extend in the longitudinal direction LD.

[0126] Between the data tracks DT in the width direction WD, a guard band GB is formed. The guard band GB is a blank area that is not used for recording and reproduction of data. For example, the guard band GB formed between the data tracks DT functions to prevent, for example, the influence of magnetic processing of one of the adjacent data tracks DT from affecting the other data track DT due to a deviation in the interval between the data recording / reproducing elements DRW (for example, a deviation within manufacturing error) or the like.

[0127] Also, between the servo band SB and the data band DB in the width direction WD, a guard band GB is formed. For example, the guard band GB between the servo band SB and the data band DB functions to prevent, for example, the magnetic influence of the servo band SB by the servo reading element SR from affecting the data tracks DT, or the magnetic influence of the data recording / reproducing elements DRW from affecting the servo band SB.

[0128] As an example, as illustrated in FIG. 2, the magnetic head 28 is provided with a first recording module DWM1, a second recording module DWM2, and a reproduction module DRM. Hereinafter, in order to facilitate explanation, in cases where it is not necessary to distinguish between the first recording module DWM1 and the second recording module DWM2, it is referred to as a "recording module DWM". Fig. 11

[0129] The recording module DWM and the reproduction module DRM are arranged in the longitudinal direction LD (in other words, in the short direction of the magnetic head 28). Fig. 11 In the illustrated example, one recording module DWM is arranged on each of the two sides of the reproduction module DRM in the longitudinal direction LD. In the illustrated example, the recording module DWM is arranged on the side of the tape reel 22 (refer to FIG. 1) in the longitudinal direction LD on the side of the tape reel 22 (refer to FIG. 1) in the longitudinal direction LD. Fig. 11 In the illustrated example, the surface side of the magnetic head 28 is schematically illustrated as being viewed from the direction opposite to the direction indicated by the arrow B in FIG. 2, and in the longitudinal direction LD, the first recording module DWM1 is arranged on the side of the tape reel 22 (refer to FIG. 1) in the two sides of the reproduction module DRM, and the second recording module DWM2 is arranged on the side of the take-up reel 38 (refer to FIG. 1) in the two sides of the reproduction module DRM. Fig. 3 Fig. 3 In the illustrated example, the surface side of the magnetic head 28 is schematically illustrated as being viewed from the direction opposite to the direction indicated by the arrow B in FIG. 2, and in the longitudinal direction LD, the first recording module DWM1 is arranged on the side of the tape reel 22 (refer to FIG. 1) in the two sides of the reproduction module DRM, and the second recording module DWM2 is arranged on the side of the take-up reel 38 (refer to FIG. 1) in the two sides of the reproduction module DRM. Fig. 3 Fig. 3

[0130] ​​​​On the recording module DWM and the reproducing module DRM, a magnetic element unit 42 is provided. The magnetic element unit 42 is provided with a servo reading element SR1, a servo reading element SR2, a first data recording element group DWG1, a second data recording element group DWG2, and a data reproducing element group DRG. The first data recording element group DWG1 is provided on the first recording module DWM1. The second data recording element group DWG2 is provided on the second recording module DWM2. The data reproducing element group DRG is provided on the reproducing module DRM.

[0131] The servo reading element SR1 is located at one end of the magnetic element unit 42, and the servo reading element SR2 is located at the other end of the magnetic element unit 42.

[0132] The data recording / reproducing element DRW has a first data recording element DW1, a second data recording element DW2, and a data reproducing element DR.

[0133] In the first data recording element group DWG1, a plurality of first data recording elements DW1 are included, and the plurality of first data recording elements DW1 are arranged in a straight line along the width direction WD (in other words, in the long side direction of the magnetic head 28 in the example shown in the drawing). The arrangement direction of the plurality of first data recording elements DW1 is parallel to the surface 31 of the magnetic tape MT, and is parallel to the width direction WD (in other words, orthogonal to the long side direction LD). Fig. 11

[0134] In the second data recording element group DWG2, a plurality of second data recording elements DW2 are included, and the plurality of second data recording elements DW2 are arranged in a straight line along the width direction WD. The arrangement direction of the plurality of second data recording elements DW2 is parallel to the surface 31 of the magnetic tape MT, and is parallel to the width direction WD (in other words, orthogonal to the long side direction LD).

[0135] In the data reproducing element group DRG, a plurality of data reproducing elements DR are included, and the plurality of data reproducing elements DR are arranged in a straight line along the width direction WD. The arrangement direction of the plurality of data reproducing elements DR is parallel to the surface 31 of the magnetic tape MT, and is parallel to the width direction WD (in other words, orthogonal to the long side direction LD).

[0136] Hereinafter, for the sake of convenience, the first data recording element DW1 and the second data recording element DW2 will be referred to as "data recording element DW" in cases where it is not necessary to distinguish between the first data recording element DW1 and the second data recording element DW2. In the present embodiment, the data recording element DW is an example of the "recording element" to which the technology of the present application pertains.

[0137] ​The data recording elements DW record data on the data tracks DT. The data reproducing elements DR reproduce data from the data tracks DT.

[0138] The first data recording element group DWG1, the second data recording element group DWG2, and the data reproducing element group DRG are arranged at a prescribed interval in the order of the first data recording element group DWG1, the data reproducing element group DRG, and the second data recording element group DWG2 from the tape supply reel 22 side to the tape take-up reel 38 side in the longitudinal direction LD. Here, the prescribed interval refers to, for example, an interval at which crosstalk does not occur between the data recording elements DW and the data reproducing elements DR, and is determined in advance by experiments and / or computer simulations and the like using actual equipment.

[0139] The servo reading elements SR have the first servo reading element SRa, the second servo reading element SRb, and the third servo reading element SRc. That is, the servo reading elements SR1 and SR2 each have the first servo reading element SRa, the second servo reading element SRb, and the third servo reading element SRc.

[0140] The first servo reading element SRa, the second servo reading element SRb, and the third servo reading element SRc are arranged in the order of the first servo reading element SRa, the second servo reading element SRb, and the third servo reading element SRc from the tape supply reel 22 (refer to Fig. 3 ) side to the tape take-up reel 38 (refer to Fig. 3 ) side in the longitudinal direction LD.

[0141] The first data recording element group DWG1 has a plurality of first data recording elements DW1. The first data recording elements DW1 record data on corresponding data tracks DT among all the data tracks DT included in the data tape DB.

[0142] On the first recording module DWM1, a pair of the first servo reading elements SRa is provided, and the pair of the first servo reading elements SRa is adjacent via the plurality of first data recording elements DW1 in the width direction WD. In the first recording module DWM1, the plurality of first data recording elements DW1 is arranged in a straight line and at equal intervals between one and the other of the pair of the first servo reading elements SRa.

[0143] The number of the plurality of first data recording elements DW1 included in the first data recording element group DWG1 is the same as the number of the data tracks DT included in the data tape DB. In the first recording module DWM1, the plurality of first data recording elements DW1 is arranged in a straight line and at equal intervals between one and the other of the pair of the first servo reading elements SRa. Fig. 11In the illustrated example, as the plurality of first data recording elements DW1, eight first data recording elements DW1 are exemplified, and the positions of these first data recording elements DW1 correspond to the positions of the data recording / reproducing elements DRW1, DRW2, DRW3, DRW4, DRW5, DRW6, DRW7, and DRW8 (refer to FIG. 1). Fig. 7 and Fig. 8

[0144] The data reproducing element group DRG has a plurality of data reproducing elements DR. The data reproducing elements DR reproduce data from the corresponding data tracks DT among all the data tracks DT included in the data band DB.

[0145] On the reproducing module DRM, a pair of second servo reading elements SRb is provided, and the pair of second servo reading elements SRb is adjacent via the plurality of data reproducing elements DR in the width direction WD. In the reproducing module DRM, the plurality of data reproducing elements DR is provided in a straight line and at equal intervals between one and the other of the pair of second servo reading elements SRb.

[0146] The number of the plurality of data reproducing elements DR included in the data reproducing element group DRG is the same as the number of the data tracks DT included in the data band DB. In Fig. 11 In the illustrated example, as the plurality of data reproducing elements DR, eight data reproducing elements DR are exemplified, and the positions of these data reproducing elements DR correspond to the positions of the data recording / reproducing elements DRW1, DRW2, DRW3, DRW4, DRW5, DRW6, DRW7, and DRW8 (refer to FIG. 1). Fig. 7 and Fig. 8

[0147] The second data recording element group DWG2 has a plurality of second data recording elements DW2. The second data recording elements DW2 record data on the corresponding data tracks DT among all the data tracks DT included in the data band DB.

[0148] On the second recording module DWM2, a pair of third servo reading elements SRc is provided, and the pair of third servo reading elements SRc is adjacent via the plurality of second data recording elements DW2 in the width direction WD. In the second recording module DMW2, the plurality of second data recording elements DW2 is provided in a straight line and at equal intervals between one and the other of the pair of third servo reading elements SRc.

[0149] The number of the plurality of second data recording elements DW2 included in the second data recording element group DWG2 is the same as the number of the data tracks DT included in the data band DB. In Fig. 11 ​​In the illustrated example, as the plurality of second data recording elements DW2, eight second data recording elements DW2 are exemplified, and the positions of these second data recording elements DW2 correspond to the positions of the data recording / reproducing elements DRW1, DRW2, DRW3, DRW4, DRW5, DRW6, DRW7, and DRW8 (refer to Fig. 7 and Fig. 8 ).

[0150] Here, an example of the geometrical relationship between the data recording element DW and the data reproducing element DR included in the data recording / reproducing element DRW corresponding to one data track DT is described.

[0151] In the magnetic head 28 on the magnetic tape MT, the center position of the data recording element DW included in the data recording / reproducing element DRW corresponding to one data track DT coincides with the center position of the data reproducing element DR in the width direction WD. Here, the center position of the data recording element DW refers to, for example, the center position of the data recording element DW in the width direction WD. Also, the center position of the data reproducing element DR refers to, for example, the center position of the data reproducing element DR in the width direction WD. Also, "coincide" refers to a coincidence in the meaning including an error that is generally allowed in the technical field to which the technology of the present application pertains and does not depart from the technical scope of the present application, in addition to a complete coincidence.

[0152] Also, in the present embodiment, the center position of the data recording element DW coincides with the center position of the data reproducing element DR in the width direction WD, but this is also to achieve so-called "Read while write: write-while-reading". In "Read while write: write-while-reading", in order to verify whether the data recorded when the recording operation is performed on the magnetic tape MT is correctly recorded, if the first recording module DWM1 records data on the magnetic tape MT based on the servo pattern signal obtained by the first servo reading element SRa, and the magnetic tape MT is transported in the forward direction, then immediately after, the data is reproduced by the reproducing module DRM. In the case where the magnetic tape MT is transported in the reverse direction, and the data is recorded on the magnetic tape MT by the second recording module DWM2, also in the same manner, "Read while write: write-while-reading" is performed between the second recording module DWM2 and the reproducing module DRM.

[0153] Also, in the data recording / reproducing element DRW corresponding to one data track DT, the length of the data recording element DW in the width direction WD, that is, the length LI is longer than the length of the data reproducing element DR in the width direction WD, that is, the length βl, and is more than twice the pitch Tp. Also, the length βl is less than the pitch Tp (refer to Fig. 10 ).

[0154] In the present embodiment, the length LI is an example of the "recording element length" to which the technology of the present application is directed. Also, in the present embodiment, the pitch Tp is an example of the "track pitch" to which the technology of the present application is directed.

[0155] After the data track DT is formed in the SMR manner by the first data recording element DWl based on the servo pattern signal obtained by the first servo reading element SRa reading the servo pattern 52 (refer to FIG. 6), data reproduction is performed from the divided data track DT_N (refer to FIG. 7) included in the data track DT by the data reproducing element DR. At this time, data reproduction is performed from the divided data track DT_N by the data reproducing element DR based on the servo pattern signal obtained by the second servo reading element SRb reading the servo pattern 52. Fig. 10 ) after the data track DT is formed in the SMR manner by the first data recording element DWl based on the servo pattern signal obtained by the first servo reading element SRa reading the servo pattern 52 (refer to FIG. 6), data reproduction is performed from the divided data track DT_N (refer to FIG. 7) included in the data track DT by the data reproducing element DR. At this time, data reproduction is performed from the divided data track DT_N by the data reproducing element DR based on the servo pattern signal obtained by the second servo reading element SRb reading the servo pattern 52. Fig. 10 ) after the data track DT is formed in the SMR manner by the first data recording element DWl based on the servo pattern signal obtained by the first servo reading element SRa reading the servo pattern 52 (refer to FIG. 6), data reproduction is performed from the divided data track DT_N (refer to FIG. 7) included in the data track DT by the data reproducing element DR. At this time, data reproduction is performed from the divided data track DT_N by the data reproducing element DR based on the servo pattern signal obtained by the second servo reading element SRb reading the servo pattern 52.

[0156] If the data track DT is formed in the SMR manner, the adjacent divided data tracks DT_N overlap, and therefore the area in which data reproduction is performed by the data reproducing element DR is narrower than when data is recorded by the first data recording element DWl. For example, in the example shown in FIG. 7, only the area corresponding to the pitch Tp within the divided data track DT_N becomes the target area for data reproduction by the data reproducing element DR. Fig. 10

[0157] The position of the first servo reading element SRa and the position of the second servo reading element SRb are aligned in the width direction WD, and therefore in the case of performing data reproduction on the data track DT formed in the SMR manner (i.e., in the case of data reproduction from the divided data track DT_N by the data reproducing element DR), the position of the head 28 needs to be shifted only by a distance Dr (= {(length LI) - (pitch Tp)} / 2) greater than the pitch Tp in the width direction WD compared to when data is recorded by the first data recording element DWl. That is, the second servo reading element SRb needs to read the servo pattern 52 on a path P that is shifted only by the distance Dr in the width direction WD from the path P through which the first servo reading element SRa passes.

[0158] For example, in the case of reproducing data from a specific divided data track DT_N formed by recording data by the data recording element DW by the data reproducing element DR, the second servo reading element SRb reads the servo pattern 52 on a path P that is shifted only by the distance Dr in the first direction WDl from the path P through which the first servo reading element SRa passes.

[0159] Next, an example of a manufacturing method for the magnetic tape MT will be described. ​

[0160] In the manufacturing method of the magnetic tape MT, a plurality of processes are included. Among the plurality of processes, a servo pattern recording process, a detection process, and a winding process are included, and here, one example of the servo pattern recording process, the detection process, and the winding process will be described with reference to Fig. 12

[0161] As one example, as shown in FIG. 1, in the servo pattern recording process, a servo writer SW is used. The servo writer SW is provided with a supply reel SW1, a take-up reel SW2, a driving device SW3, a pulse signal generator SW4, a control device SW5, a plurality of guides SW6, a conveyance path SW7, a servo pattern recording head WH, and a verification head VH. In the present embodiment, the servo pattern recording head WH is one example of the “servo writing head” to which the technology of the present application pertains. Fig. 12

[0162] The control device SW5 controls the entire servo writer SW. In the present embodiment, the control device SW5 is implemented by an ASIC, but the technology of the present application is not limited thereto. For example, the control device SW5 can also be implemented by an FPGA and / or a PLC. Also, the control device SW5 can also be implemented by a computer including a CPU, a flash memory (for example, an EEPROM and / or an SSD, etc.), and a RAM. Also, it can be implemented by combining two or more of the ASIC, the FPGA, the PLC, and the computer. That is, the control device SW5 can also be implemented by a combination of a hardware structure and a software structure.

[0163] On the supply reel SW1, a pancake is provided. The pancake refers to a large-diameter magnetic tape roll on which a magnetic tape MT of a product width is wound on a hub before the servo pattern 52 is written.

[0164] The driving device SW3 has a motor (omitted from the drawing) and a gear (omitted from the drawing), and is mechanically connected to the supply reel SW1 and the take-up reel SW2. In a case where the magnetic tape MT is wound by the take-up reel SW2, the driving device SW3 generates power according to a command from the control device SW5, and transmits the generated power to the supply reel SW1 and the take-up reel SW2, thereby causing the supply reel SW1 and the take-up reel SW2 to rotate. That is, the supply reel SW1 rotates by receiving power from the driving device SW3, thereby sending out the magnetic tape MT to a predetermined conveyance path SW7. The take-up reel SW2 rotates by receiving power from the driving device SW3, thereby winding the magnetic tape MT sent out from the supply reel SW1. The rotational speed and the rotational torque 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 by the take-up reel SW2.

[0165] ​​On the conveyance path SW7, a plurality of guides SW6 and a servo pattern recording head WH are arranged. 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 fed from the supply reel SWl to the conveyance path SW7 is guided by the plurality of guides SW6 to pass over the servo pattern recording head WH and is taken up by the take-up reel SW2.

[0166] 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. In a state where the magnetic tape MT is running at a prescribed speed on the conveyance path SW7, the servo pattern recording head WH records a plurality of servo patterns 52 in the direction of the long side LD (refer to FIG. 2) in a region predetermined for forming the servo band SB in accordance with the pulse signal supplied from the pulse signal generator SW4, thereby forming the servo band SB on the magnetic tape MT. Fig. 6

[0167] The detection process is a process of detecting the magnetic tape MT on which the servo band SB is formed. For example, in the detection process, the servo band SB formed on the surface 31 of the magnetic tape MT by the servo pattern recording head WH is detected. The detection of the servo band SB refers to, for example, a process of determining whether the servo patterns 52 recorded on the servo band SB are correct. The determination of whether the servo patterns 52 are correct refers to, for example, a determination of whether the magnetization straight lines 54Ala, 54A2a, 54Bla and 54B2a are not excessive or insufficient at the positions predetermined in the surface 31 for the servo patterns 52A and 58B, and whether they are recorded within an allowable error (i.e., verification of the servo patterns 52).

[0168] The detection of the servo band SB is performed by using the control device SW5 and a verification head VH. The verification head VH is arranged at a position on the downstream side in the conveyance direction of the magnetic tape MT from the servo pattern recording head WH. As with the magnetic head 28, a plurality of servo reading elements (omitted from illustration) are provided on the verification head VH, and the plurality of servo bands SB are read by the plurality of servo reading elements.

[0169] The verification head VH is connected to the control device SW5. The verification head VH is arranged at a position directly opposite the servo band SB when viewed from the surface 31 side of the magnetic tape MT (i.e., the back surface side of the verification head VH), and reads the servo patterns 52 recorded on the servo band SB, and outputs the read results (hereinafter referred to as "servo pattern read results") to the control device SW5. The control device SW5 performs the detection of the servo band SB (e.g., the determination of whether the servo patterns 52 are correct) based on the servo pattern read results (e.g., servo pattern signals) input from the verification head VH.

[0170] ​The control device SW5 outputs information indicating the result of detecting the servo band SB (for example, the result of determining whether the servo pattern 52 is correct) to a predetermined output destination (for example, a storage device built into the servo writer SW, a display connected to the servo writer SW, and / or an external device connected in a manner capable of communicating with the servo writer SW, etc.).

[0171] If the detection process is completed (for example, if it is determined that the servo band SB is correctly formed on the magnetic tape MT during the detection process), the winding process is performed. The winding process is a process in which a plurality of magnetic tape cassettes 12 (refer to FIG. 1 ) are wound. Figs. 1-4 ) respectively used for the tape supply reel 22 (ie, accommodated in the tape cassette 12 (reference Figs. 1-4 ) in the tape supply reel 22 (reference Figs. 2-4 )) Winding up the magnetic tape MT. In the winding process, a winding motor M is used. The winding motor M is mechanically connected to the supply reel 22 via gears and the like. Under the control of a control device (not shown in the figure), the winding motor M applies a rotational force to the supply reel 22 to rotate the supply reel 22. The magnetic tape MT wound onto the take-up reel SW2 is wound up by the supply reel 22 as the supply reel 22 rotates. In the winding process, a cutting device (not shown in the figure) is used. When the required amount of magnetic tape MT is wound up by 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 the cutting device.

[0172] exist Fig. 13 In the figure, it is shown that the Fig. 12 ) is an example of the structure of the servo pattern recording head WH when the servo pattern recording head WH is observed from the surface 31 side of the magnetic tape MT traveling thereon (i.e., the back side of the servo pattern recording head WH), and an example of the structure of the pulse signal generator SW4.

[0173] As an example, Fig. 13 As shown, the servo pattern recording head WH includes a base WH1 and a plurality of magnetic head cores WH2. The base WH1 is formed into a rectangular parallelepiped shape and is arranged to span the surface 31 of the magnetic tape MT traveling along the transport path SW7 in the width direction WD. The surface WH1A of the base WH1 is a rectangle having long sides WH1Aa and short sides WH1Ab, with the long sides WH1Aa spanning the surface 31 of the magnetic tape MT in the width direction WD.

[0174] The surface WH1A has a sliding surface WH1Ax. The sliding surface WH1Ax is a surface of the surface WH1A that overlaps with the surface 31 of the magnetic tape MT when the base WH1 extends across the surface 31 of the magnetic tape MT in the width direction WD. The sliding surface WH1Ax slides on the magnetic tape MT during tape travel. Fig. 13The width of the sliding surface WH1Ax (i.e., the length in the direction LD1 (e.g., the same direction as the longitudinal direction LD) corresponding to the longitudinal direction LD) shown is merely an example, and the width of the sliding surface WH1Ax can be larger than Fig. 13 The example shown is several times as wide.

[0175] The longitudinal direction of the base WH1, i.e., the direction WD3 (i.e., the direction along the long side WH1Aa) is a direction (e.g., the same direction as the width direction WD) corresponding to the width direction WD. In the base WH1, a plurality of head cores WH2 are assembled along the direction WD3. On the surface WH1A (i.e., the surface of the side of the base WH1 opposite the surface 31 of the magnetic tape MT) of the head core WH2, a plurality of gap patterns G are formed at intervals along the direction WD3.

[0176] In the present embodiment, the direction WD3 is an example of the "second longitudinal direction" to which the technology of the present application pertains. Also, in the present embodiment, the surface WH1A is an example of the "opposite surface" to which the technology of the present application pertains. Also, in the present embodiment, the gap pattern G is an example of the "gap pattern" to which the technology of the present application pertains.

[0177] The gap pattern G is composed of a pair of straight line regions that are not parallel. By a pair of straight line regions that are not parallel, for example, a straight line region having the same geometric property as that of the magnetization straight line 54A1a on the upstream side in the positive direction among the five magnetization straight lines 54A1a included in the linear magnetization region 54A1 shown, and a straight line region having the same geometric property as that of the magnetization straight line 54A2a on the upstream side in the positive direction among the five magnetization straight lines 54A2a included in the linear magnetization region 54A2 shown are meant. Fig. 6 The gap pattern G is composed of a pair of straight line regions that are not parallel. By a pair of straight line regions that are not parallel, for example, a straight line region having the same geometric property as that of the magnetization straight line 54A1a on the upstream side in the positive direction among the five magnetization straight lines 54A1a included in the linear magnetization region 54A1 shown, and a straight line region having the same geometric property as that of the magnetization straight line 54A2a on the upstream side in the positive direction among the five magnetization straight lines 54A2a included in the linear magnetization region 54A2 shown are meant. Fig. 6 The gap pattern G is composed of a pair of straight line regions that are not parallel. By a pair of straight line regions that are not parallel, for example, a straight line region having the same geometric property as that of the magnetization straight line 54A1a on the upstream side in the positive direction among the five magnetization straight lines 54A1a included in the linear magnetization region 54A1 shown, and a straight line region having the same geometric property as that of the magnetization straight line 54A2a on the upstream side in the positive direction among the five magnetization straight lines 54A2a included in the linear magnetization region 54A2 shown are meant.

[0178] On the surface WH1A, a plurality of gap patterns G are formed at intervals along the direction WD3. On the surface WH1A, the interval in the direction WD3 between the gap patterns G adjacent in the direction WD3 corresponds to the interval in the width direction WD between the servo bands SB of the magnetic tape MT (i.e., the servo band pitch).

[0179] A coil (omitted from illustration) is wound on the head core WH2, and a pulse signal is supplied to the coil. The pulse signal supplied to the coil is a pulse signal for the servo pattern 52A and a pulse signal for the servo pattern 52B.

[0180] When the servo writer SW configured as described above performs a servo pattern recording process, the servo pattern recording head WH is arranged in a posture in which the surface 31 of the magnetic tape MT faces the plurality of gap patterns G. Then, while maintaining this posture, the servo write head WH records the plurality of servo patterns G along the longitudinal direction LD on the surface 31 of the magnetic tape MT, thereby forming a plurality of servo bands SB on the surface 31 (see FIG. 1 ). Fig. 6 ). Hereinafter, a method of forming a plurality of servo bands SB on the surface 31 will be described in more detail.

[0181] When a pulse signal for the servo pattern 52A is supplied to the coil of the head core WH2 with the gap pattern G facing (in other words, directly facing) the area predetermined for forming the servo band SB on the surface 31 of the magnetic tape MT traveling on the transport path SW7, a magnetic field is applied from the gap pattern G to the servo band SB of the magnetic tape MT in response to the pulse signal. As a result, the servo pattern 52A is recorded in the area predetermined for forming the servo band SB on the surface 31 of the magnetic tape MT. Furthermore, when a pulse signal for the servo pattern 52B is supplied to the coil of the head core WH2 with the gap pattern G facing (in other words, directly facing) the area predetermined for forming the servo band SB on the surface 31 of the magnetic tape MT traveling on the transport path SW7, a magnetic field is applied from the gap pattern G to the servo band SB on the magnetic tape MT. As a result, the servo pattern 52B is recorded in the area predetermined for forming the servo band SB on the surface 31 of the magnetic tape MT. In this manner, the servo patterns 52A and 52B are alternately formed along the longitudinal direction in the area predetermined in advance for forming the servo band SB on the surface 31 of the magnetic tape MT, thereby forming the servo band SB.

[0182] For each servo pattern 52 (ie, each frame 50 (reference Fig. 6 By modulating the pulse signal, various information is embedded in the pulse signal. In this case, for example, by modulating the pulse signal for the servo pattern 52A, the five magnetization straight lines 54A1a (see FIG. 1 ) can be changed for each servo pattern 52A. Fig. 6 ) between the third magnetized straight line 54A1a and the second magnetized straight line 54A1a (hereinafter referred to as the "first interval"), and between the third magnetized straight line 54A1a and the fourth magnetized straight line 54A1a (hereinafter referred to as the "second interval"). By making the first interval and the second interval different for each servo pattern 52A, at least one bit of information can be embedded in each servo pattern 52A. Thus, by combining multiple servo patterns 52, various types of information can be embedded.

[0183] The various types of information include, for example, information regarding the position of the magnetic tape MT in the longitudinal direction LD, information for identifying the servo band SB, and / or information for specifying the manufacturer of the magnetic tape MT.

[0184] exist Fig. 13 In the illustrated example, head cores WH2A, WH2B, and WH2C are shown as examples of a plurality of head cores WH2, and gap patterns G1, G2, and G3 are shown as examples of a plurality of gap patterns G. Gap pattern G1 is formed on head core WH2A. Gap pattern G2 is formed on head core WH2B. Gap pattern G3 is formed on head core WH2C.

[0185] The gap patterns G1 to G3 have the same geometric characteristics. In this embodiment, for example, the gap pattern G1 is used to adjust the servo band SB3 (refer to Fig. 6 ) Recording servo pattern 52 (reference Fig. 6 ), the gap pattern G2 is used for the servo band SB2 (reference Fig. 6 ) Recording servo pattern 52 (reference Fig. 6 ), the gap pattern G3 is used for the servo band SB1 (reference Fig. 6 ) Recording servo pattern 52 (reference Fig. 6 ).

[0186] Gap pattern G1 is a pair of straight line regions consisting of straight line regions G1A and G1B. Furthermore, gap pattern G2 is a pair of straight line regions consisting of straight line regions G2A and G2B. Furthermore, gap pattern G3 is a pair of straight line regions consisting of straight line regions G3A and G3B. In this embodiment, gap patterns G1 to G3 are examples of the "multiple gap patterns" involved in the technology of this invention.

[0187] The pulse signal generator SW4 includes 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 magnetic head core WH2A. The second pulse signal generator SW4B is connected to the magnetic head core WH2B. The third pulse signal generator SW4C is connected to the magnetic head core WH2C.

[0188] The gap pattern G1 is used to form the servo band SB3 (refer to Fig. 6 ), when the first pulse signal generator SW4A supplies a pulse signal to the head core WH2A, a magnetic field is applied from the gap pattern G1 to an area predetermined in advance for forming the servo band SB3 on the surface 31 of the magnetic tape MT according to the pulse signal, and a servo pattern 52 (reference Fig. 6 ).

[0189] For example, if a pulse signal for the servo pattern 52A is supplied to the head core WH2A with the gap pattern G1 facing (in other words, facing) the area predetermined for forming the servo band SB3 on the surface 31 of the magnetic tape MT traveling on the transport path SW7, the servo pattern 52A is recorded in the area predetermined for forming the servo band SB3 on the surface 31 of the magnetic tape MT (see FIG. Fig. 6 That is, in the area predetermined in advance for forming the servo band SB3 within the surface 31 of the magnetic tape MT, the linear magnetized area 54A1 is recorded via the straight area G1A (refer to Fig. 6 ), and the linear magnetized region 54A2 is recorded in the servo band SB3 through the straight region G1B (reference Fig. 6 Thus, the servo pattern 52A is formed in the area predetermined in advance for forming the servo band SB3 within the surface 31 of the magnetic tape MT.

[0190] Furthermore, for example, if a pulse signal for the servo pattern 52B is supplied to the head core WH2A with the gap pattern G1 facing (in other words, facing) the area predetermined for forming the servo band SB3 on the surface 31 of the magnetic tape MT traveling on the transport path SW7, the servo pattern 52B is recorded in the area predetermined for forming the servo band SB1 on the surface 31 of the magnetic tape MT (see FIG. 1 ). Fig. 6 That is, in the area predetermined in advance for forming the servo band SB1 within the surface 31 of the magnetic tape MT, the linear magnetized area 54B1 (refer to Fig. 6 ), and, in an area predetermined in advance for forming the servo band SB3 within the surface 31 of the magnetic tape MT, a linear magnetized area 54B2 is recorded by the straight area G1B (reference Fig. 6 Thus, the servo pattern 52B is formed in the area predetermined in advance for forming the servo band SB3 within the surface 31 of the magnetic tape MT.

[0191] In this manner, the servo patterns 52A and 52B are alternately formed along the longitudinal direction LD in the area predetermined in advance for forming the servo band SB3 on the surface 31 of the magnetic tape MT, thereby forming the servo band SB3.

[0192] The gap pattern G2 is used to form the servo band SB2 (refer to Fig. 6 ), when the second pulse signal generator SW4B supplies a pulse signal to the head core WH2B, a magnetic field is applied from the gap pattern G2 to an area predetermined in advance for forming the servo band SB2 on the surface 31 of the magnetic tape MT according to the pulse signal, and a servo pattern 52 is recorded in the area predetermined in advance for forming the servo band SB2 on the surface 31 of the magnetic tape MT (refer to FIG. Fig. 6 ).

[0193] For example, if a pulse signal for the servo pattern 52A is supplied to the head core WH2B with the gap pattern G2 facing (in other words, facing) the area predetermined for forming the servo band SB2 on the surface 31 of the magnetic tape MT traveling on the transport path SW7, the servo pattern 52A is recorded in the area predetermined for forming the servo band SB2 on the surface 31 of the magnetic tape MT (see FIG. Fig. 6 That is, in the area predetermined in advance for forming the servo band SB2 on the surface 31 of the magnetic tape MT, the linear magnetized area 54A1 is recorded by the straight area G2A, and in the area predetermined in advance for forming the servo band SB2 on the surface 31 of the magnetic tape MT, the linear magnetized area 54A2 is recorded by the straight area G2B (refer to Fig. 6 Thus, the servo pattern 52A is formed in the area predetermined in advance for forming the servo band SB2 within the surface 31 of the magnetic tape MT.

[0194] Furthermore, for example, if a pulse signal for the servo pattern 52B is supplied to the head core WH2B with the gap pattern G2 facing (in other words, facing) the area on the surface 31 of the magnetic tape MT that is traveling on the transport path SW7 where the servo band SB2 is predetermined to be formed, the servo pattern 52B is recorded in the area on the surface 31 of the magnetic tape MT that is predetermined to form the servo band SB2. Specifically, the linear magnetized area 54B1 is recorded by the straight line area G2A in the area on the surface 31 of the magnetic tape MT that is predetermined to form the servo band SB2, and the linear magnetized area 54B2 is recorded by the straight line area G2B in the area on the surface 31 of the magnetic tape MT that is predetermined to form the servo band SB2 (see FIG. 1 ). Fig. 6 Thus, the servo pattern 52B is formed in the area predetermined in advance for forming the servo band SB2 within the surface 31 of the magnetic tape MT.

[0195] In this manner, in the area predetermined in advance for forming the servo band SB2 on the surface 31 of the magnetic tape MT, the servo patterns 52A and 52B are alternately formed along the longitudinal direction LD, thereby forming the servo band SB2.

[0196] The gap pattern G3 is used to form the servo band SB1 (refer to Fig. 6 ), when the third pulse signal generator SW4C supplies a pulse signal to the head core WH2C, a magnetic field is applied from the gap pattern G3 to an area predetermined in advance for forming the servo band SB1 on the surface 31 of the magnetic tape MT according to the pulse signal, and a servo pattern 52 is recorded in the area predetermined in advance for forming the servo band SB1 on the surface 31 of the magnetic tape MT (refer to FIG. Fig. 6 ).

[0197] For example, if the gap pattern G3 is set so as to face the region in which the servo band SB1 is formed in the surface 31 of the magnetic tape MT running on the transport path SW7 (in other words, face each other), and the pulse signal for the servo pattern 52A is supplied to the head core WH2C, the servo pattern 52A is recorded in the region in which the servo band SB1 is formed in the surface 31 of the magnetic tape MT. That is, in the region in which the servo band SB1 is formed in the surface 31 of the magnetic tape MT, the linear magnetization region 54A1 is recorded by the linear region G3A (refer to FIG. 10A), and in the region in which the servo band SB1 is formed in the surface 31 of the magnetic tape MT, the linear magnetization region 54A2 is recorded by the linear region G3B (refer to FIG. 10B). Thus, in the region in which the servo band SB1 is formed in the surface 31 of the magnetic tape MT, the servo pattern 52A is formed. Fig. 6 Fig. 6

[0198] For example, if the gap pattern G3 is set so as to face the region in which the servo band SB1 is formed in the surface 31 of the magnetic tape MT running on the transport path SW7 (in other words, face each other), and the pulse signal for the servo pattern 52B is supplied to the head core WH2C, the servo pattern 52B is recorded in the region in which the servo band SB1 is formed in the surface 31 of the magnetic tape MT. That is, in the region in which the servo band SB1 is formed in the surface 31 of the magnetic tape MT, the linear magnetization region 54B1 is recorded by the linear region G3A (refer to FIG. 11A), and in the region in which the servo band SB1 is formed in the surface 31 of the magnetic tape MT, the linear magnetization region 54B2 is recorded by the linear region G3B (refer to FIG. 11B). Thus, in the region in which the servo band SB1 is formed in the surface 31 of the magnetic tape MT, the servo pattern 52B is formed. Fig. 6 Fig. 6

[0199] Thus, in the region in which the servo band SB1 is formed in the surface 31 of the magnetic tape MT, the servo patterns 52A and 52B are alternately formed in the longitudinal direction LD, and the servo band SB1 is formed.

[0200] ​​​​The magnetic head core WH2C has a magnetic film 60 and a base glass 62. The magnetic film 60 forms a base of the magnetic head core WH2C. As an example of the magnetic film 60, a metal film can be given. In this case, the concept of the "metal film" also includes an alloy film. As an example of the metal film, a stacked film formed by stacking one or more metal materials selected from a group including one or more pure metals and one or more alloys can be given. Also, one or more additives can be contained in the metal film, and one or more impurities that are inevitably mixed can be contained. The magnetic film 60 can also be an iron-based alloy film. In this case, "based on" means "containing". The iron-based alloy film is preferably a nitrided iron-based alloy film. As an example of the nitrided iron-based alloy, as a constituent element, one or two or more constituent elements selected from a group including Al and / or Ta, and the like can be given in addition to Fe and N. The magnetic film 60 can also be obtained as a stacked film formed by stacking a metal material on a substrate by a publicly known film forming method such as physical vapor deposition (PVD) and / or chemical vapor deposition (CVD), and the like. The base glass 62 forms a base of the magnetic head core WH2C together with the magnetic film 60. In the base glass 62, a non-magnetic material is used. A flat surface 66 is formed by the magnetic film 60 and the base glass 62.

[0201] A linear opening 66A is formed on the base glass 62, and the base G3B1 is formed by filling the opening 66A with a non-magnetic body 68 such as silicon dioxide and / or aluminum. The base G3B1 is a base of the linear region G3B.

[0202] The magnetic head core WH2C is formed by a method using photolithography. If the base G3B1 having a low degree of straightness of the ridge line region 70 is directly used as the linear region G3B, it is difficult to record a servo pattern 52 having a high degree of straightness on the surface 31 of the magnetic tape MT. If the degree of straightness of the servo pattern 52 is reduced, the precision of the servo control is also reduced.

[0203] As a method of improving the degree of straightness of the ridge line region 70, for example, the following first to third methods can be given. The first method is a method of improving the degree of straightness of the ridge line region 70 by improving the precision of a photomask used in photolithography. The second method is a method of trimming the entire width of the opening portion 66A of the magnetic head core WH2C formed by a method using photolithography with an FIB or a laser, thereby forming a linear groove 71 having a size corresponding to the entire width of the opening portion 66A, and filling the groove 71 with the non-magnetic body 68, thereby forming the linear region G3B. The third method is a method of trimming the ridge line region 70 of the base G3B1 of the magnetic head core WH2C formed by a method using photolithography in a linear shape with an FIB or a laser, thereby forming a groove 72, and filling the groove 72 with the non-magnetic body 68, thereby forming the linear region G3B.

[0204] With regard to the third method, for example, first, the magnetic head core WH2C formed by the method using photolithography is processed using FIB or a laser, thereby forming the base G3B1. That is, the ridge line region 70 of the base G3B1 of the magnetic head core WH2C formed by the method using photolithography is irradiated by FIB or a laser along the long side direction of the base G3B1, and thereby the ridge line region 70 of the base G3B1 is trimmed to be linear. Then, the non-magnetic body 68 is filled in the groove 72 obtained by trimming the base G3B1 using FIB. The linear region G3B is formed by thus forming the base G3B1. Thus, by performing processing using any of the first to third methods, the linearity of the linear region G3B can be improved, and the durability of the linear region G3B can be improved.

[0205] In addition, here, the linear region G3B is exemplified, but the linear regions G1A, G1B, G2A, G2B, and G3A are also obtained by performing the same processing as the processing performed to obtain the linear region G3B, respectively.

[0206] Thus, by processing the magnetic head core WH2 using FIB or a laser, the linearity of the linear regions G1A, G1B, G2A, G2B, G3A, and G3B is improved, and as a result, on the surface 31 of the magnetic tape MT, a plurality of servo patterns 52 having high linearity are formed along the long side direction LD for each servo band SB.

[0207] In the present embodiment, in order to further improve the linearity of each servo pattern 52 included in each servo band SB, as an example, as shown in FIG. 8, a linearity detection method is performed on the magnetic tape MT on which a plurality of servo bands SB are formed. Fig. 6

[0208] The linearity detection method is a method of detecting the linearity of the servo pattern 52 formed on the magnetic tape MT, and is performed in the detection process included in the manufacturing method of the magnetic tape MT described above, for example. In addition, this is only an example, and detection using the linearity detection method can also be performed using the magnetic tape drive 14. The linearity detection method can also be realized by a manual measurement or the like performed mainly by a detector (omitted from the drawing), or can be realized by automation mainly using a detection device (omitted from the drawing). In the present embodiment, the linearity detection method shown in FIG. 8 is an example of the "detection method" to which the technology of the present application is directed. Fig. 6

[0209] In the present embodiment, the linearity detection method shown in FIG. 8 is an example of the "detection method" to which the technology of the present application is directed. Fig. 6 ​​In the straightness detection method shown, first, in step ST10, from among the two servo bands SB (for example, servo band SB2 and servo band SB3) adjacent in the width direction WD in the magnetic tape MT in which the plurality of servo bands SB are formed by the servo pattern recording process described above, a pair of servo patterns 52 that have not been detected adjacent in the width direction WD (i.e., a pair of servo patterns 52 of the servo patterns 52 for which detection of straightness has not been performed) are selected.

[0210] In next step ST12, an index (hereinafter, also simply referred to as "index") indicating the non-straightness of the servo patterns 52 is acquired from the pair of servo patterns 52 that have not been detected selected in step ST10.

[0211] In next step ST14, detection is performed on the magnetic tape MT using the index acquired in step ST12. For example, in step ST14, the straightness of the pair of servo patterns 52 that have not been detected selected in step ST10 is detected using the index acquired in step ST12.

[0212] In next step ST16, it is determined whether the straightness of all of the detection targets (i.e., all of the pairs of servo patterns 52 determined in advance as detection targets) included in the two servo bands SB adjacent in the width direction WD in the magnetic tape MT have been detected. In step ST16, in the case where the straightness of all of the detection targets included in the two servo bands SB adjacent in the width direction WD in the magnetic tape MT has not been detected, the determination is negated, and the straightness detection method proceeds to step ST10. In step ST16, in the case where the straightness of all of the detection targets included in the two servo bands SB adjacent in the width direction WD in the magnetic tape MT has been detected, the determination is affirmed, and the straightness detection method ends.

[0213] In addition, here, a manner example in which the straightness detection method is applied to the two servo bands SB adjacent in the width direction WD (for example, servo band SB2 and servo band SB3) in the magnetic tape MT is presented for the sake of facilitating understanding of the technology of the present application, but the straightness detection method can also be applied to other two servo bands SB adjacent in the width direction WD (i.e., servo band SB1 and servo band SB2) in the magnetic tape MT. That is, in the case where three or more servo bands SB are arranged in the width direction WD on the magnetic tape MT, the straightness detection method can be applied to all of the pairs of servo bands SB adjacent in the width direction WD, respectively.

[0214] Here, a specific example of a method of deriving the index is described.

[0215] A plurality of PESs are used in the index. The PES refers to a position in the width direction WD in the servo pattern 52. The PES is measured using the following equation (1).

[0216] [Equation 1]

[0217]

[0218] In Fig. 6 , a conceptual diagram for explaining variables used in Equation (1) for measuring PES and PES of linear magnetization regions 54A1 within the servo pattern 52A as the magnetic tape MT is forwardly running is shown.

[0219] In Equation (1), "α1" is an angle that is determined in advance as an angle of a virtual straight line Cl and the linear magnetization region 54A1. In Equation (1), "α2" is an angle that is determined in advance as an angle of the virtual straight line Cl and the linear magnetization region 54A2. Also, in the present embodiment, since the linear magnetization regions 54A1 and 54A2 are inclined in a line-symmetrical manner with respect to the virtual straight line Cl, "α1" and "α2" are the same value.

[0220] In Equation (1), "i" is a natural number of 1 to 4. The maximum value of "i" (4 here) is the number of magnetization lines 54A1a used for the measurement of PES. In Equation (1), "Ai" refers to a distance between the magnetization line 54A1a and the magnetization line 54A2a at positions corresponding to each other when the servo read element SR3 of the verification head VH is straddled across the servo pattern 52A in the longitudinal direction LD. Here, the "magnetization line 54A1a and the magnetization line 54A2a at positions corresponding to each other" refers to the 1st to 4th magnetization line pairs. The 1st magnetization line pair refers to the magnetization line 54A1a and the magnetization line 54A2a that are located at the most upstream side of the running direction of the magnetic tape MT in the linear magnetization regions 54A1 and 54A2, respectively. The 2nd magnetization line pair refers to the magnetization line 54A1a and the magnetization line 54A2a that are located at the 2nd positions from the most upstream side to the downstream side of the running direction of the magnetic tape MT in the linear magnetization regions 54A1 and 54A2, respectively. The 3rd magnetization line pair refers to the magnetization line 54A1a and the magnetization line 54A2a that are located at the 3rd positions from the most upstream side to the downstream side of the running direction of the magnetic tape MT in the linear magnetization regions 54A1 and 54A2, respectively. The 4th magnetization line refers to the magnetization line 54A1a and the magnetization line 54A2a that are located at the 4th positions from the most upstream side to the downstream side of the running direction of the magnetic tape MT in the linear magnetization regions 54A1 and 54A2, respectively.

[0221] In Equation (1), "Bi" is the distance between the magnetization lines 54Ala and 54Bl a at positions corresponding to each other when the servo reading element SR3 is positioned across the servo pattern 52A and the servo pattern 52B adjacent to the servo pattern 52A on the forward side in the longitudinal direction LD. Here, the "magnetization lines 54Ala and 54Bl a at positions corresponding to each other" refer to the 5th to 8th magnetization line pairs. The 5th magnetization line pair refers to the magnetization lines 54Ala and 54Bl a at the most upstream side in the tape running direction of the magnetic tape MT in the linear magnetization region 54Al in the servo pattern 52A and the linear magnetization region 54Bl in the servo pattern 52B adjacent to the servo pattern 52A on the forward side, respectively. The 6th magnetization line pair refers to the magnetization lines 54Ala and 54Bl a at the 2nd position from the most upstream side to the downstream side in the tape running direction of the magnetic tape MT in the linear magnetization region 54Al in the servo pattern 52A and the linear magnetization region 54Bl in the servo pattern 52B adjacent to the servo pattern 52A on the forward side, respectively. The 7th magnetization line pair refers to the magnetization lines 54Ala and 54Bl a at the 3rd position from the most upstream side to the downstream side in the tape running direction of the magnetic tape MT in the linear magnetization region 54Al in the servo pattern 52A and the linear magnetization region 54Bl in the servo pattern 52B adjacent to the servo pattern 52A on the forward side, respectively. The 8th magnetization line pair refers to the magnetization lines 54Ala and 54Bl a at the 4th position from the most upstream side to the downstream side in the tape running direction of the magnetic tape MT in the linear magnetization region 54Al in the servo pattern 52A and the linear magnetization region 54Bl in the servo pattern 52B adjacent to the servo pattern 52A on the forward side, respectively.

[0222] In Equation (1), "d" is a distance determined in advance as the distance between the linear magnetization regions 54Al and 54Bl in the longitudinal direction LD. As an example of "d", a distance determined in advance as the distance between the magnetization lines 54Ala and 54Bl a at positions corresponding to each other when the servo reading element SR3 is positioned across the servo patterns 52A and 52B in the longitudinal direction LD can be given.

[0223] In addition, here, an example in which Equation (1) is used to measure the PES in the servo pattern 52A when the magnetic tape MT is running in the forward direction is given, but Equation (1) is also used to measure the PES in the servo pattern 52B. In this case, "Bi" is the distance between the magnetization lines 54Bl a and 54Ala at positions corresponding to each other when the servo reading element SR3 is positioned across the servo pattern 52B and the servo pattern 52A adjacent to the servo pattern 52B on the forward side in the longitudinal direction LD.

[0224] “Ai” and “Bi” are measured based on the servo pattern signal obtained by reading the servo pattern 52 by the servo read element SR3 of the verification head VH.

[0225] When PES sets the center position of the servo pattern 52 in the width direction WD (for example, the position where a virtual straight line C3 passing through the center of the servo pattern 52 in the width direction WD along the long side direction LD intersects the servo pattern 52) to "0", the position within the servo pattern 52 that is closer to the first direction WD1 side than the virtual straight line C3 is represented by a positive value, and the position within the servo pattern 52 that is closer to the second direction WD2 side than the virtual straight line C3 is represented by a negative value.

[0226] As an example, Fig. 6 As shown, a pair of servo patterns 52 adjacent in the width direction WD (hereinafter also referred to as an "adjacent servo pattern pair") included in two servo bands SB adjacent in the width direction WD (hereinafter also referred to as an "adjacent servo band pair") in the magnetic tape MT having a plurality of servo bands SB formed by the above-mentioned servo pattern recording process are read by the servo reading element SR3 used in each servo band SB, and a plurality of dPESs are measured based on the servo pattern signals obtained by reading each servo pattern 52.

[0227] If one of the servo patterns 52 (eg, Fig. 6 The PES measured for the upper servo pattern 52 shown in FIG. 1 is set as PES1, and the other servo pattern 52 included in the adjacent servo pattern pair (for example, Fig. 6 If the PES measured for the lower servo pattern 52 shown is PES2, the difference between PES1 and PES2, dPES, can be measured. If the magnetic tape MT is not deformed in the width direction WD, the servo pattern 52 has perfect straightness, and the interval between two adjacent servo read elements SR3 in the width direction WD is at the designed center, dPES is "0."

[0228] During the inspection process, the straightness of the servo pattern 52 must be inspected. Details will be described later, but multiple PESs and dPESs are measured at multiple locations from one end of the servo pattern 52 (here, as an example, the end on the first direction WD1) to the other end (here, as an example, the end on the second direction WD2). Then, ΔdPES, the PES difference gap, is measured from the multiple PESs and dPESs.

[0229] In one servo pattern 52 and another servo pattern 52, a plurality of first positions 74 and a plurality of second positions 76 are set. One servo pattern 52 is a servo pattern 52 included in a pair of adjacent servo patterns recorded at corresponding positions in the width direction WD in the pair of adjacent servo bands, that is, Fig. 6 The other servo pattern 52 is the servo pattern 52 included in the adjacent servo pattern pair recorded at the corresponding position in the width direction WD in the adjacent servo band pair, that is, Fig. 6 The servo pattern 52 on the underside is shown.

[0230] In the linear magnetized region 54A1 included in one servo pattern 52 (for example, the magnetized straight line 54A1a located on the most upstream side in the positive direction), a plurality of first positions 74 and a plurality of second positions 76 are set from one end of the linear magnetized region 54A1 (for example, the end on the first direction WD1 side) to the other end (for example, the end on the second direction WD2 side). The plurality of first positions 74 and the plurality of second positions 76 are in a predetermined corresponding relationship. The first positions 74 and the second positions 76 in a corresponding positional relationship are set on the linear magnetized region 54A1 at intervals INT1 along the width direction WD. Furthermore, the first positions 74 and the second positions 76 in a corresponding positional relationship are set on the linear magnetized region 54A1 at intervals INT2 along the width direction WD. The interval INT1 is approximately equivalent to the above-mentioned distance Dr (refer to Fig. 6 ), and interval INT2 is approximately equal to interval Tp. In this embodiment, for ease of explanation, the description assumes that "interval INT1 = distance Dr" and "interval INT2 = distance Tp." However, this is merely an example, and the technology of the present invention still applies even if "interval INT1 ≈ distance Dr" and "interval INT2 ≈ distance Tp." In this embodiment, interval INT1 is an example of the "first predetermined interval" involved in the technology of the present invention. Interval INT2 is an example of the "second predetermined interval" involved in the technology of the present invention.

[0231] Between interval INT1 and interval Tp, the size relationship of "interval INT1>interval Tp" holds. Also, between interval INT1 and interval INT2, the size relationship of "interval INT1>interval INT2" holds. Also, interval INT1 is the interval closest to the reference interval. The reference interval is an interval that is a natural number multiple (e.g., a natural number multiple of 2 or more) of interval INT2 and is equivalent to length L1 (reference Fig. 6 Here, as an example of the interval INT1, 1200 nm (nanometers) is used, and as an example of the interval INT2, 400 nm is used.

[0232] In Fig. 6 In the example shown, in a case where the variable n is set to a natural number of 3 or more, dPES is roughly divided into dPES(n) and dPES(n-3). In the present embodiment, dPES(n-3) is an example of the "1st PES difference" to which the technology of the present application pertains. Also, in the present embodiment, dPES(n) is an example of the "2nd PES difference" to which the technology of the present application pertains.

[0233] In the straightness detection method (for example, Fig. 6 In the step ST12 included in the straightness detection method (for example,

[0234] In the straightness detection method (for example, Fig. 6 In the step ST12 included in the straightness detection method (for example,

[0235] In the straightness detection method (for example, Fig. 6In the step ST12 included in the straightness detection method shown, a plurality of AdPESs are measured from the plurality of dPES(n-3) and the plurality of dPES(n). The AdPES is the difference between the dPES(n-3) and the dPES(n) in a corresponding relationship with each other. The dPES(n-3) and the dPES(n) in a corresponding relationship with each other refer to the dPES(n-3) and the dPES(n) for the first position 74 and the second position 76 in a relationship of being separated by only the interval INT1 along the width direction WD. In the present embodiment, the AdPES is an example of the "PES difference gap" to which the technology of the present application pertains.

[0236] In the present embodiment, the interval INT2 is set to one step, and the variable n corresponds to the number of measurement steps. In the present embodiment, 1200 nm is used as an example of the interval INT1, and 400 nm is used as an example of the interval INT2, and the value of the dPES at a position separated by only the ratio (in other words, the ratio) of the interval INT2 to the interval INT1, that is, "3" measurement steps is used to calculate the AdPES. The variable n is incremented by one each time the first position 74 and the second position 76 are advanced by one measurement step along the second direction WD2. That is, each time the first position 74 and the second position 76 are shifted by the interval INT2 along the second direction WD2, the variable n is incremented by one, and a pair of the first position 74 and a pair of the second position 76 are updated in correspondence therewith. If a pair of the first position 74 and a pair of the second position 76 are updated, the dPES(n-3) is measured for the updated pair of the first position 74, and the dPES(n) is measured for the updated pair of the second position 76. Then, each time the dPES(n-3) and the dPES(n) are measured, the AdPES (that is, the difference between the dPES(n-3) and the dPES(n)) is measured from the measured dPES(n-3) and the dPES(n).

[0237] Thus, in the present embodiment, the plurality of AdPESs are measured from the plurality of dPES(n-3) and the plurality of dPES(n) in a corresponding relationship with each other. Fig. 6 In the example shown, in the adjacent pair of servo pattern pairs, the AdPES is measured for each interval INT2 along the second direction WD2 for the pair of linearly magnetized regions 54A1 adjacent in the width direction WD, and thereby a plurality of AdPESs are obtained.

[0238] Also, in the same manner as the plurality of first positions 74 and the plurality of second positions 76 are provided on the pair of linear magnetization regions 54Al included in the adjacent servo pattern pair, a plurality of first positions 74 and a plurality of second positions 76 are also provided on the pair of linear magnetization regions 54A2 (e.g., the magnetization straight line 54A2a included in one of the pair of linear magnetization regions 54A2 on the most upstream side in the forward direction and the magnetization straight line 54A2a included in the other of the pair of linear magnetization regions 54A2 on the most upstream side in the forward direction) included in the adjacent servo pattern pair. Also, in the same manner as the plurality of dPES(n) and the plurality of dPES(n-3) are measured for the plurality of first positions 74 and the plurality of second positions 76 on the pair of linear magnetization regions 54Al included in the adjacent servo pattern pair, the plurality of dPES(n) and the plurality of dPES(n-3) are also measured for the plurality of first positions 74 and the plurality of second positions 76 on the pair of linear magnetization regions 54A2 included in the adjacent servo pattern pair. Further, in the same manner as the plurality of dPES is measured from the plurality of dPES(n) and the plurality of dPES(n-3) measured for the plurality of first positions 74 and the plurality of second positions 76 on the pair of linear magnetization regions 54Al included in the adjacent servo pattern pair, the plurality of dPES is also measured from the plurality of dPES(n) and the plurality of dPES(n-3) measured for the plurality of first positions 74 and the plurality of second positions 76 on the pair of linear magnetization regions 54A2 included in the adjacent servo pattern pair.

[0239] Also, in the same manner as the plurality of first positions 74 and the plurality of second positions 76 are provided on the pair of servo patterns 52A included in the adjacent servo pattern pair, the plurality of first positions 74 and the plurality of second positions 76 are also provided on the pair of servo patterns 52B adjacent in the width direction WD. Also, in the same manner as the plurality of dPES(n) and the plurality of dPES(n-3) are measured for the plurality of first positions 74 and the plurality of second positions 76 on the pair of servo patterns 52A included in the adjacent servo pattern pair, the plurality of dPES(n) and the plurality of dPES(n-3) are also measured for the plurality of first positions 74 and the plurality of second positions 76 on the pair of servo patterns 52B adjacent in the width direction WD. Further, in the same manner as the plurality of dPES is measured from the plurality of dPES(n) and the plurality of dPES(n-3) measured for the plurality of first positions 74 and the plurality of second positions 76 on the pair of servo patterns 52A included in the adjacent servo pattern pair, the plurality of dPES is also measured from the plurality of dPES(n) and the plurality of dPES(n-3) measured for the plurality of first positions 74 and the plurality of second positions 76 on the pair of servo patterns 52B adjacent in the width direction WD.

[0240] The magnetic tape MT is not deformed in the width direction WD, and the straightness of the servo pattern 52 is also ideal, but in a case where the interval of the two servo reading elements SR3 adjacent to the width direction WD is offset from the design center, dPES becomes a value corresponding to the amount by which the interval of the two servo reading elements SR3 adjacent to the width direction WD is offset from the design center. Also, in a case where the magnetic tape MT is deformed in the width direction WD, dPES becomes a value corresponding to the amount of deformation of the magnetic tape MT in the width direction WD.

[0241] However, by measuring ΔdPES (i.e., the difference between dPES(n) and dPES(n-3)), the amount of deformation of the magnetic tape MT in the width direction WD and the amount by which the interval of the two servo reading elements SR3 adjacent to the width direction WD is offset from the design center cancel each other out.

[0242] If this is described in detail, in dPES, there is included a value corresponding to the amount by which the interval of the two servo reading elements SR3 adjacent to the width direction WD is offset from the design center, a value corresponding to the amount of deformation of the magnetic tape MT in the width direction WD, and a value indicating the straightness of the servo pattern 52. However, for example, in a case where the magnetic tape MT is not deformed in the width direction WD, and there is a deviation in the interval between the servo reading elements SR adjacent to the width direction WD from the design value, since both dPES(n) and dPES(n-3) include the same deviation in the interval between the servo reading elements SR from the design value, by finding the difference between dPES(n) and dPES(n-3), the amount of deviation in the interval between the servo reading elements SR from the design value cancels out, and only the value indicating the straightness of the servo pattern 52 is calculated. With the same line of reasoning, even if the magnetic tape MT is deformed in the width direction WD, it can be considered that the same deformation occurs at the first position 74 and the second position 76, and therefore, in the same way, by finding the difference between dPES(n) and dPES(n-3), the amount of deformation of the magnetic tape MT in the width direction WD cancels out, and only the value indicating the straightness of the servo pattern 52 is calculated. Therefore, the straightness of the servo pattern 52 is indicated by a plurality of ΔdPES measured from a plurality of dPES(n) and a plurality of dPES(n-3) corresponding to a plurality of first positions 74 and a plurality of second positions 76.

[0243] Therefore, in the straightness detection method shown in FIG. 8, in step ST12 included in the method, an index is acquired from a plurality of ΔdPES. Hereinafter, a specific example of a method of acquiring an index from a plurality of ΔdPES, and a method of detecting the straightness of the servo pattern 52 of the magnetic tape MT using the index will be described. Fig. 6 As an example, as shown in FIG. 9, the index is acquired from the maximum value of a plurality of ΔdPES.

[0244] Fig. 6 ​As shown, in a case where the data reproducing element DR is aligned on track with the divided data track DT_N in a manner such that the center of the data reproducing element DR in the width direction WD is coincident with the center of the divided data track DT_N having a pitch Tp of 500 nm and a length βl of 350 nm, blanks BS1 and BS2 are generated between the divided data track DT_N and the data reproducing element DR. The blank BS1 is a blank generated on the first direction WD1 side, and the blank BS2 is a blank generated on the second direction WD2 side.

[0245] The length of the blank BS1 in the width direction WD and the length of the blank BS2 in the width direction WD each correspond to 15% of the pitch Tp.

[0246] In the straightness detection method shown in FIG. 8, the step ST12 included in the straightness detection method is performed. Fig. 6 In the step ST12 included in the straightness detection method shown in FIG. 8, the average μ and the standard deviation σ of the plurality of ΔdPES measured by the adjacent servo pattern pairs are calculated. The standard deviation σ indicates the degree of straightness of the servo pattern 52. The smaller the standard deviation σ, the higher the degree of straightness of the servo pattern 52. Therefore, in the servo pattern recording process described above, it is preferable to record the servo pattern 52 on the magnetic tape MT in a manner such that the standard deviation σ is as small as possible.

[0247] In the straightness detection method shown in FIG. 8, the step ST12 included in the straightness detection method is performed. Fig. 6 In the step ST12 included in the straightness detection method shown in FIG. 8, the average μ and the standard deviation σ of the plurality of ΔdPES measured by the adjacent servo pattern pairs are calculated. The standard deviation σ indicates the degree of straightness of the servo pattern 52. The smaller the standard deviation σ, the higher the degree of straightness of the servo pattern 52. Therefore, in the servo pattern recording process described above, it is preferable to record the servo pattern 52 on the magnetic tape MT in a manner such that the standard deviation σ is as small as possible.

[0248] In the straightness detection method shown in FIG. 8, the step ST12 included in the straightness detection method is performed. Fig. 6 In the step ST12 included in the straightness detection method shown in FIG. 8, the average μ and the standard deviation σ of the plurality of ΔdPES measured by the adjacent servo pattern pairs are calculated. The standard deviation σ indicates the degree of straightness of the servo pattern 52. The smaller the standard deviation σ, the higher the degree of straightness of the servo pattern 52. Therefore, in the servo pattern recording process described above, it is preferable to record the servo pattern 52 on the magnetic tape MT in a manner such that the standard deviation σ is as small as possible.

[0249] Therefore, in order to easily record data on the magnetic tape MT and at a position desired by a user or the like, and to align the data reproducing element DR on the divided data track DT_N, in the straightness detection method shown in FIG. 8, the step ST12 included in the straightness detection method is performed. Fig. 6In the step ST14 included in the straightness detection method shown, it is judged whether or not the straightness judgment condition of "3σ control being 15% or less of the interval Tp" is satisfied. This is because, as long as 3σ control is 15% or less of the interval Tp, it is expected that the data reproducing element DR aligns with the divided data track DT_N with a probability of 99.7%.

[0250] In the case where the straightness judgment condition is satisfied, it is judged that the straightness of the servo pattern 52 is within the allowable range, and in the case where the straightness judgment condition is not satisfied, it is judged that the straightness of the servo pattern 52 is outside the allowable range. Then, the magnetic tape MT in which it is judged that the straightness of the servo pattern 52 is within the allowable range is adopted, and the magnetic tape MT in which it is judged that the straightness of the servo pattern 52 is outside the allowable range is not adopted. Also, in the case where it is judged that the straightness of the servo pattern 52 is within the allowable range, the servo pattern recording head WH is not replaced, and in the case where it is judged that the straightness of the servo pattern 52 is outside the allowable range, the servo pattern recording head WH is replaced (for example, replacement of the servo pattern recording head WH in which the straightness of the gap pattern G is improved).

[0251] In the present embodiment, the standard deviation σ is an example of the "standard deviation" to which the technology of the present application relates. Also, in the present embodiment, 3σ is an example of the "index" and the "value equivalent to three times the standard deviation of the plurality of PES difference gaps".

[0252] In Fig. 6 , an example of the distribution of the plurality of dPES obtained from the magnetic tape MT manufactured without using the straightness judgment condition but by the conventionally known technology, and the distribution of the plurality of dPES obtained from the magnetic tape MT manufactured through the process in which it is judged that the straightness of the servo pattern 52 is within the allowable range using the straightness judgment condition is shown. In Fig. 6 , an example of the distribution of the plurality of ΔdPES obtained from the magnetic tape MT manufactured without using the straightness judgment condition but by the conventionally known technology, and the distribution of the plurality of ΔdPES obtained from the magnetic tape MT manufactured through the process in which it is judged that the straightness of the servo pattern 52 is within the allowable range using the straightness judgment condition is shown.

[0253] As an example, as shown in Fig. 6 , the distribution of the plurality of dPES obtained from the magnetic tape MT manufactured through the process in which it is judged that the straightness of the servo pattern 52 is within the allowable range using the straightness judgment condition has better concentration than the distribution of the plurality of dPES obtained from the magnetic tape MT manufactured without using the straightness judgment condition but by the conventionally known technology. That is, the deviation of dPES is small.

[0254] As an example, as shown in Fig. 6As shown in FIG. 6, the distribution of the plurality of ΔdPES obtained from the magnetic tape MT manufactured in the process of judging that the straightness of the servo pattern 52 is within the allowable range using the straightness judgment condition has better concentration than the distribution of the plurality of ΔdPES obtained from the magnetic tape MT manufactured by the conventionally known technique without using the straightness judgment condition. That is, the deviation of the ΔdPES is small.

[0255] In Fig. 6 FIG. 6, an example of the distribution of the plurality of ΔdPES obtained under the first condition shown in Table 1 is shown. In Fig. 6 FIG. 7, an example of the distribution of the plurality of ΔdPES obtained under the second condition shown in Table 2 is shown.

[0256] [Table 1]

[0257] [First Condition]

[0258] Fig. 6 2.5 Fig. 6 1.0 Fig. 6 0.75

[0259] [Table 2]

[0260] [Second Condition]

[0261] Fig. 6 10 Fig. 6 0.5 Fig. 6 4.75

[0262] As an example, as shown in Fig. 6 and Fig. 6 the distribution of the plurality of ΔdPES obtained under the first condition has better concentration than the distribution of the plurality of ΔdPES obtained under the second condition. That is, the deviation of the ΔdPES is small.

[0263] In Table 3, the value of 3σ obtained when the magnetic tape MT is manufactured under the first condition using the first servo pattern recording head (hereinafter, also referred to as "first head"), the second servo pattern recording head (hereinafter, also referred to as "second head"), and the third servo pattern recording head (hereinafter, also referred to as "third head") respectively is shown. In Table 4, the value of 3σ obtained when the magnetic tape MT is manufactured under the second condition using the first head, the second head, and the third head respectively is shown.

[0264] In addition, the first head is a servo pattern recording head related to the conventionally known technique, and the opening of the gap pattern G is formed by MEMS processing. The second head is a servo pattern recording head manufactured by the above-described second method (by using FIB or laser to Fig. 6The entire width of the opening portion 66A shown is trimmed to form a groove 71, and a method of filling the groove 71 with the non-magnetic body 68 forms a servo pattern recording head WH of the openings of the gap pattern G. The 3rd magnetic head is a servo pattern recording head obtained by performing MEMS processing on the openings of the gap pattern G under processing conditions different from the processing conditions used in the MEMS processing of the openings of the gap pattern G by the 1st servo pattern recording head.

[0265] [Table 3]

[0266] [Under the 1st condition]

[0267] Fig. 6 Fig. 6 Fig. 6 Fig. 6 42 21 36 Fig. 6 4 2 4

[0268] ※Pitch Tp = 1000 [nm]

[0269] [Table 4]

[0270] [Under the 2nd condition]

[0271] Fig. 6 Fig. 6 Fig. 6 Fig. 6 79.2 45 60 Fig. 6 16 9 12

[0272] ※Pitch Tp = 500 [nm]

[0273] Next, the operation of the magnetic tape system 10 according to the present embodiment will be described with reference to Fig. 6

[0274] First, a case where the data tracks DT are formed on the magnetic tape MT by the 1st recording module DWM1 will be described, the magnetic tape MT being judged by the straightness detection method that the straightness of all the servo patterns 52 as detection targets is within the allowable range (i.e., the straightness judgment condition is satisfied).

[0275] As an example, as shown in Fig. 6 first, the pair of 1st servo reading elements SRa is located on the servo bands SB adjacent in the width direction WD. Specifically, one of the pair of 1st servo reading elements SRa (hereinafter, also referred to as "one 1st servo reading element SRa") is located on the servo band SB3, and the other of the pair of 1st servo reading elements SRa (hereinafter, also referred to as "the other 1st servo reading element SRa") is located on the servo band SB2. If described more specifically, the 1st recording module DWM1 is positioned on the magnetic tape MT by moving the magnetic head 28 in the width direction WD so that one 1st servo reading element SRa is located on the path Pa1 of the servo band SB3, and the other 1st servo reading element SRa is located on the path Pa1 of the servo band SB2.

[0276] ​In this state, the magnetic tape MT is caused to run in the forward direction, and each data recording element DWl of the first recording module DWMl is caused to perform a recording process. Thereby, as an example, as shown in Fig. 6, a divided data track DT_l is formed on the magnetic tape MT by each data recording element DWl of the first recording module DWMl. Fig. 6

[0277] After the divided data track DT_l is formed, the magnetic tape MT is caused to run in the reverse direction, whereby the first recording module DWMl is returned to the position at which the divided data track DT_l was started to be formed. Then, in a state in which the magnetic head 28 is caused to be shifted only by the pitch Tp in the second direction WD2, the magnetic tape MT is caused to run in the forward direction, and each data recording element DWl of the first recording module DWMl is caused to perform a recording process. Thereby, on the magnetic tape MT, a divided data track DT_2 is formed by each data recording element DWl of the first recording module DWMl.

[0278] In the same manner as in the case in which the divided data tracks DT_l and DT_2 are sequentially formed, the divided data tracks DT_3 to DT_12 are sequentially formed by each data recording element DWl of the first recording module DWMl. Thereby, as an example, as shown in Fig. 7, in the width direction WD, between the servo bands SB2 and SB3, a data band DB2 including the data tracks DTl to DT8 is formed. Fig. 6

[0279] Further, in the case in which the divided data tracks DT_l to DT_12 are sequentially formed, the first servo reading element SRa is sequentially positioned on the paths Pal to Path Pa 12 which are set at every pitch Tp from the first direction WDl side to the second direction WD2 side with respect to the plurality of servo patterns 52 included in the servo bands SB. Then, the servo patterns 52 within each servo band SB are read by the first servo reading element SRa along the paths Pal to Path Pa 12, respectively, and servo control is performed in accordance with the servo pattern signals thus obtained.

[0280] Next, a case in which data is sequentially reproduced from the divided data track DT_l to the divided data track DT_12 included in each data track DT by the reproducing module DRM will be described.

[0281] As an example, as shown in Figs. 8 and 9, the divided data tracks DT_l to DT_12 are sequentially reproduced by the reproducing module DRM, and the data bands DBl to DB4 are sequentially reproduced. Fig. 6 Fig. 6 ​​​As shown, of the plurality of servo patterns 52 included in the servo band SB, from the first direction WDl side to the second direction WD2 side, the paths Pb1 to Pb12 are provided at every pitch Tp. The paths Pb1 to Pb12 correspond to the paths Pal to Pa12, and the paths Pb1 to Pb12 are respectively provided at positions offset by only the distance Dr from each of the paths Pal to Pa12 toward the first direction WDl side.

[0282] As an example, as shown in Fig. 6, first, the pair of the second servo reading elements SRb is positioned on the servo bands SB adjacent in the width direction WD. Specifically, one of the pair of the second servo reading elements SRb (hereinafter, also referred to as "one second servo reading element SRb") is positioned on the servo band SB3, and the other of the pair of the second servo reading elements SRb (hereinafter, also referred to as "the other second servo reading element SRb") is positioned on the servo band SB2. If explained more specifically, by moving the magnetic head 28 in the width direction WD, the reproduction module DRM is positioned on the magnetic tape MT so that one second servo reading element SRb is positioned on the path Pb1 of the servo band SB3, and the other second servo reading element SRb is positioned on the path Pb1 of the servo band SB2. Fig. 6 In this state, the magnetic tape MT is run in the forward direction, and each data reproduction element DR of the reproduction module DRM performs the reproduction process. Thereby, on the magnetic tape MT, data is reproduced from the divided data track DT_1 by each data reproduction element DR of the reproduction module DRM.

[0283] After the data reproduction from the divided data track DT_1, the magnetic tape MT is run in the reverse direction, whereby the reproduction module DRM is returned to the position where the data reproduction from the divided data track DT_1 was performed. Then, in a state where the magnetic head 28 is moved in the second direction WD2 by only the pitch Tp, the magnetic tape MT is run in the forward direction, and each data reproduction element DR of the reproduction module DRM performs the reproduction process. Thereby, on the magnetic tape MT, data is reproduced from the divided data track DT_2 by each data reproduction element DR of the reproduction module DRM.

[0284] In the same manner as the data reproduction from the divided data tracks DT_1 and DT_2 is sequentially performed, the data reproduction from the divided data track DT_3 to the divided data track DT_12 is sequentially performed by each data reproduction element DR of the reproduction module DRM.

[0285] In the same manner as the data reproduction from the divided data tracks DT_1 and DT_2 is sequentially performed, the data reproduction from the divided data track DT_3 to the divided data track DT_12 is sequentially performed by each data reproduction element DR of the reproduction module DRM.

[0286] Fig. 6 ​In the example shown, one second servo read element SRb is located on path Pb12 of servo band SB3, and the other second servo read element SRb is located on path Pb12 of servo band SB2. In this state, the magnetic tape MT is forward-traveled, and the data reproduction elements DR of the reproduction module DRM are performing reproduction processing. Consequently, data is reproduced from the divided data track DT_12 on the magnetic tape MT by the data reproduction elements DR of the reproduction module DRM.

[0287] Here, an example of reproducing data from split data tracks DT_1 to DT_12 is given, but this is just an example. Data can also be reproduced from split data track DT_12 to split data track DT_1, or from split data track DT_N specified by a user.

[0288] In addition, Fig. 6 In the example shown, the case where the divided data tracks DT_1 to DT_12 are sequentially shifted at a pitch Tp along the second direction WD2 and overlapped is described, but the technology of the present invention is not limited to this. Fig. 6 As shown, multiple divided data tracks DT_N can also be formed by overlapping along the first direction WD1 using the SMR method. In this case, the second recording module DWM2 can be used. Specifically, the magnetic tape MT is reversed by sequentially moving the pair of third servo read elements SRc from path Pa12 to path Pa1. The pair of third servo read elements SRc are then moved along path P, and the pair of third servo read elements SRc read the servo pattern 52. Based on the servo pattern signal thus obtained, the magnetic head 28 is moved along the first direction WD1, and the divided data tracks DT_12 to DT_1 are sequentially overlapped along the first direction WD1.

[0289] In this case, data is also reproduced from the divided data tracks DT_1 to DT_12 by the data reproduction elements DR of the reproduction module DRM. Paths Pb1 to Pb12 are respectively set to be offset from paths Pa1 to Pa12 by a distance Dr in the second direction WD2. When reproducing data from the divided data tracks DT_1 to DT_12, the second servo read element SRb reads the servo pattern 52 using paths Pb1 to Pb12, and servo control is performed based on the servo pattern signals obtained.

[0290] Here, the example in which the reproduction of data is sequentially performed from the divided data tracks DT_1 to the divided data tracks DT_12 is presented, but this is only an example, and the reproduction of data can be sequentially performed from the divided data tracks DT_12 to the divided data tracks DT_1, or from the divided data track DT_N specified by a user or the like.

[0291] As explained above, in the present embodiment, in the detection process included in the manufacturing method of the magnetic tape MT, the straightness detection method (refer to Fig. 6 ) is used to detect the straightness of the servo pattern 52 recorded on the magnetic tape MT in the servo pattern recording process (refer to Fig. 6 the step ST14 shown in FIG. 7). In the present embodiment, in order to detect the straightness of the servo pattern 52, a plurality of ΔdPESs (refer to Fig. 6 ) are measured.

[0292] The ΔdPES is the difference between dPES(n-3) and dPES(n) (refer to Fig. 6 ). The dPES(n-3) is the difference in PES between a pair of first positions 74 corresponding in the width direction WD in a pair of servo patterns 52 recorded between a pair of servo bands SB adjacent in the width direction WD among the plurality of servo bands SB and at corresponding positions in the width direction WD (refer to Fig. 6 ). The dPES(n) is the difference in PES between a pair of second positions 76 offset from the pair of first positions 74 by an interval INT1 larger than the interval INT2 in the width direction WD in a pair of servo patterns 52 recorded between a pair of servo bands SB adjacent in the width direction WD among the plurality of servo bands SB and at corresponding positions in the width direction WD (refer to Fig. 6 ).

[0293] The plurality of ΔdPESs are obtained by measuring the ΔdPES at each interval INT2 along the width direction WD in a pair of servo patterns 52. In the present embodiment, in order to detect the straightness of the servo pattern 52, the degree of deviation of the plurality of ΔdPESs from the average of the plurality of ΔdPESs is obtained as an index indicating the non-straightness of the servo pattern 52 (refer to the step ST12 shown in FIG. 7). Then, using the index indicating the non-straightness of the servo pattern 52, the detection of the straightness of the servo pattern 52 of the magnetic tape MT is performed (refer to the step ST14 shown in FIG. 7). Fig. 6 Fig. 6 .

[0294] In the present embodiment, in the case where the index indicating the non-straightness of the servo pattern 52 is controlled to be 15% or less of the pitch Tp (refer to​Fig. 6 ), it is determined that the straightness of the servo pattern 52 of the magnetic tape MT is within the allowable range (i.e., there is no problem in the straightness of the servo pattern 52 as a servo pattern for servo control). Also, in a case where the condition that the index indicating the non-straightness of the servo pattern 52 is controlled to be 15% or less of the pitch Tp is not satisfied, it is determined that the straightness of the servo pattern 52 of the magnetic tape MT is outside the allowable range (i.e., there is a problem in the straightness of the servo pattern 52 as a servo pattern for servo control). 15% of the pitch Tp respectively corresponds to the length of the blank BS1 in the width direction WD and the length of the blank BS2 in the width direction WD (refer to FIG. 2). Fig. 6 ) The index controlled to be 15% or less of the pitch Tp means that high-precision servo control can be achieved compared to a case where the index exceeds 15% of the pitch Tp. This means that the plurality of divided data tracks DT_N can be formed with high precision, and the data reproducing element DR can perform high-precision tracking with respect to the divided data tracks DT_N.

[0295] Thus, by determining whether the condition that the index indicating the non-straightness of the servo pattern 52 is controlled to be 15% or less of the pitch Tp is satisfied, it is possible to adopt the magnetic tape MT as a shipment-use magnetic tape MT, which has only the plurality of servo patterns 52 satisfying the condition that the index indicating the non-straightness of the servo pattern 52 is controlled to be 15% or less of the pitch Tp. By adopting the magnetic tape MT in which the straightness of the servo pattern 52 is guaranteed at such a high level as a shipment-use magnetic tape MT, it is possible to contribute to improvement in the precision of recording data on the magnetic tape MT and the precision of reproducing data recorded in the magnetic tape MT.

[0296] Also, in the present embodiment, the index is obtained for each of all the pairs of adjacent servo bands (for example, the pair of the servo bands SB2 and SB3 and the pair of the servo bands SB1 and SB2) included in the magnetic tape MT. Then, the detection of the magnetic tape MT is performed using all the indices. Thus, compared to a case where the detection of the magnetic tape MT is performed with respect to the magnetic tape MT in which three or more servo bands SB are arranged in the width direction using only the index obtained from one pair of adjacent servo bands, the magnetic tape MT can be detected with good precision.

[0297] Also, in the present embodiment, the index obtained for each of all the pairs of adjacent servo bands included in the magnetic tape MT is controlled to be 15% or less of the pitch Tp, respectively. Thus, compared to a case where the index obtained from one pair of adjacent servo bands with respect to the magnetic tape MT in which three or more servo bands SB are arranged in the width direction is controlled to be 15% or less of the pitch Tp, it is possible to contribute to improvement in the precision of recording data on the magnetic tape MT and the precision of reproducing data recorded in the magnetic tape MT.

[0298] Furthermore, in this embodiment, data is recorded using the SMR method based on multiple servo patterns 52 on a magnetic tape MT that satisfies the condition that the index representing the non-linearity of the servo pattern 52 is controlled to be less than 15% of the pitch Tp (i.e., the magnetic tape MT maintains a high level of linearity of the servo pattern 52). This forms multiple divided data tracks DT_N on the magnetic tape MT. Therefore, the quality of the multiple divided data tracks DT_N formed by recording data on the magnetic tape MT using the SMR method can be maintained at a high level, and data can be reproduced from the multiple divided data tracks DT_N with high accuracy.

[0299] In this embodiment, the average value μ and the standard deviation σ of a plurality of ΔdPES are calculated. Then, as an index indicating the non-linearity of the servo pattern 52, a graph 78 (see FIG. 78 ) indicating a normal distribution obtained from the average value μ and the standard deviation σ is used. Fig. 6 ) of 3σ (reference Fig. 6 In the enclosed region of 3σ in graph 78, ΔdPES exists with a probability of 99.7%. In this embodiment, by determining whether the condition of 3σ being controlled to be less than 15% of the pitch Tp is satisfied, it is possible to use as shipping tape MT a tape MT recorded only with a plurality of servo patterns 52 satisfying the condition of 3σ being controlled to be less than 15% of the pitch Tp. Using a tape MT with such a high level of guaranteed straightness of the servo patterns 52 as shipping tape MT contributes to improved data recording accuracy and data reproduction accuracy on the tape MT.

[0300] Furthermore, in this embodiment, as for ΔdPES (reference Fig. 6 ) of the measurement interval INT1 (reference Fig. 6 ), using the natural number multiple closest to the interval INT2 (in Fig. 6 In the example shown, it is 3 times) and corresponds to the reference interval of length L1 (reference Fig. 6 ) and spacing Tp (reference Fig. 6 )). Therefore, compared to a case where the interval INT1 is determined independently of the length L1 and the pitch Tp, even if the plurality of divided data tracks DT_N are highly densely packed, the data reproduction element DR can be accurately aligned with each of the plurality of divided data tracks DT_N when reproducing data.

[0301] Furthermore, in this embodiment, as for ΔdPES (reference Fig. 6 ) of the measurement interval INT1 (reference Fig. 6 ), using the equivalent of interval INT2 (reference Fig. 6) is 3 times the interval of the ΔdPEs. Thus, a plurality of ΔdPEs for obtaining an index indicating the non-linearity of the servo pattern 52 can be collected, and neither excess nor deficiency (refer to Fig. 6 ) occurs.

[0302] The interval INT1 (refer to Fig. 6 ) is an interval corresponding to a distance Dr in which the head 28 moves in the width direction WD by tracking when reproducing data between the adjacent divided data tracks DT_N in the width direction WD. When the distance Dr is short, the tracking when recording data and the tracking when reproducing data are performed in a state in which the position of the first servo reading element SRa used when recording data and the position of the second servo reading element SRb used when reproducing data are close. Thus, even if distortion occurs in the servo pattern signal, the influence of the distortion can be suppressed to be small. Conversely, if the distance Dr becomes long, the influence of the distortion becomes relatively large, and the position shift based on the distortion becomes large.

[0303] If it is assumed that data is recorded on the magnetic tape MT in the SMR manner, the difference between the position of the first servo reading element SRa in the case where the divided data track DT_1 is formed at the first time of recording data and the position of the second servo reading element SRb in the case where the divided data track DT_2 is formed at the second time of recording data corresponds to the pitch Tp.

[0304] In the case where the distance Dr (refer to Fig. 6 , Fig. 6 and Fig. 6 ) at the time of reproducing data is shorter than the pitch Tp (refer to Fig. 6 and Fig. 6 ), the influence of the position shift at the time of reproducing data is controlled within the range of the influence of the position shift at the time of recording data, and the influence of the linearity of the servo pattern 52 becomes small.

[0305] Conversely, in the case where the distance Dr at the time of reproducing data is larger than the pitch Tp, the influence of the position shift at the time of reproducing data is not controlled within the range of the influence of the position shift at the time of recording data, and the influence of the linearity of the servo pattern 52 becomes large. This causes a decrease in the performance of the servo control.

[0306] Thus, in the present embodiment, as the interval corresponding to the distance Dr, the interval INT1 (refer to Fig. 6), using an interval larger than the pitch Tp. Thus, the servo pattern 52 is formed in a manner that the index (e.g., 3σ) indicating the degree of variation of the plurality of ΔdPES determined according to the interval INT1 larger than the pitch Tp is controlled to be below 15% of the pitch Tp. Therefore, even if the plurality of divided data tracks DT_N are densified, the data reproduction element DR can be accurately aligned with each of the plurality of divided data tracks DT_N at the time of reproducing data, compared to the case where the interval INT1 is below the pitch Tp.

[0307] In addition, in the above embodiment, the index (e.g., 3σ) obtained for each of the adjacent servo track pairs is controlled to be below 15% of the pitch Tp, but the technology of the present application is not limited thereto. For example, the index obtained for each of the adjacent servo track pairs can be controlled to be below 10% of the pitch Tp, or the index obtained for each of the adjacent servo track pairs can be controlled to be below 5% of the pitch Tp. In this case, the index obtained for each of the adjacent servo track pairs can be controlled to be below 5% of the pitch Tp. Fig. 6 In the example shown, 500 nm is given as an example of the length β1, but if the index is controlled to be below 10% of the pitch Tp, the length β1 can be extended to 400 nm, and if the index is controlled to be below 5% of the pitch Tp, the length β1 can be extended to 450 nm. In this way, as long as the length β1 can be extended, it is expected that the performance of reproducing data can be improved. Furthermore, the PES based on the variation of the magnetic tape MT in the width direction WD is a major cause of the positional displacement of the data reproduction element DR, but by setting the index to be below 10% of the pitch Tp, or by setting the index to be below 5% of the pitch Tp, it is possible to achieve a design that improves the tolerance to the positional displacement caused by the PES.

[0308] In the above embodiment, the case where the divided data tracks DT_1 to DT_12 are sequentially shifted and overlapped along the second direction WD2 with the pitch Tp is described, but the technology of the present application is not limited thereto. For example, as shown in Fig. 10, the plurality of divided data tracks DT_N can be overlapped along the first direction WD1 in an SMR manner. In this case, the second recording module DWM2 can be used. Specifically, by moving the pair of third servo reading elements SRc sequentially from the path P12 to the path P1 to run the magnetic tape MT in the reverse direction, moving the pair of third servo reading elements SRc along the path P, and reading the servo pattern 52 by the pair of third servo reading elements SRc, the servo pattern signal is obtained. Based on the servo pattern signal, the head 28 is moved along the first direction WD1, and the divided data tracks DT_12 to DT_1 are sequentially overlapped along the first direction WD1. The reproduction of the data from the divided data tracks DT_1 to DT_12 is performed by the data reproduction elements DR of the reproduction module DRM. Fig. 6

[0309] ​In addition, Fig. 6 and Fig. 6 In the example shown, the paths Pb1 to Pb12 of the servo pattern 52 for reading and reproducing data are set at positions offset by a distance Dr to the first direction WD1 side relative to the paths Pa1 to Pa12. Fig. 6 In the illustrated example, the paths Pb1 to Pb12 of the servo pattern 52 used for reading reproduced data are set at positions offset by a distance Dr in the second direction WD2 from the paths Pa1 to Pa12 .

[0310] In recent years, research has been progressing on technologies to reduce the effects of TDS. TDS is known to be affected by factors such as temperature, humidity, the pressure of the tape on the reel, and aging. Without any measures, TDS increases, leading to off-track (i.e., positional deviation of the data recording / reproducing element DRW relative to the divided data tracks DT_N within the data tape DB) when magnetic processing is performed on the data tape DB.

[0311] For example, if the width of the magnetic tape MT decreases over time, it may become off-track. Off-track refers to a state in which the data recording / reproducing element DRW is not located on a designated divided data track DT_N among the divided data tracks DT1_1, DT1_2, DT1_3, DT1_4, ..., DT1_11, and DT1_12 included in the divided data track group DTG (i.e., a state in which the position of the designated divided data track DT_N is offset from the position of the data recording / reproducing element DRW in the width direction WD).

[0312] The width of the magnetic tape MT may sometimes increase, and in this case, the tracks may also deviate. Specifically, if the width of the magnetic tape MT narrows or widens over time, the position of the servo read element SR relative to the servo pattern 52 may shift in the width direction WD from the predetermined design position (i.e., the predetermined design positions of the linear magnetized regions 54A1, 54A2, 54B1, and 54B2). If the position of the servo read element SR relative to the servo pattern 52 shifts in the width direction WD from the predetermined design position, servo control accuracy decreases, and the tracks within the data band DB (for example, the designated divided data track DT_N among the divided data tracks DT1_1, DT1_2, DT1_3, DT1_4, ..., DT1_11, and DT1_12) may shift relative to the data recording / reproducing element DRW. Consequently, magnetic processing may not be performed on the originally designated divided data track DT_N.

[0313] As a method of reducing the influence of TDS, a method of adjusting the width of the magnetic tape MT by adjusting the tension applied to the magnetic tape MT can be considered. However, if the amount of deformation of the magnetic tape MT in the width direction WD is too large, even if the tension applied to the magnetic tape MT is adjusted, the deviation from the track can not be eliminated. Also, if the tension applied to the magnetic tape MT is strengthened, the load applied to the magnetic tape MT becomes large, and the life of the magnetic tape MT can be shortened. Furthermore, if the tension applied to the magnetic tape MT is too weak, the contact state of the head 28 with the magnetic tape MT becomes unstable, and thus the head 28 can not be able to perform the magnetic processing on the magnetic tape MT. As a method of reducing the influence of TDS by a method other than adjusting the tension applied to the magnetic tape MT, as an example, as shown in Fig. 6 , a method of keeping the position of the servo reading element SR with respect to the servo pattern 52 at a position that is designed to be a predetermined position by causing the head 28 to be deflected on the magnetic tape MT is known.

[0314] Therefore, as an example, as shown in Fig. 6 , the first recording module DWM1 can also be arranged in a posture of being tilted with respect to the width direction WD along the surface 31 of the magnetic tape MT with the rotational axis RAl as the center. Also, the reproducing module DRM can also be arranged in a posture of being tilted with respect to the width direction WD along the surface 31 of the magnetic tape MT with the rotational axis RA2 as the center. Furthermore, the second recording module DWM2 can also be arranged in a posture of being tilted with respect to the width direction WD along the surface 31 of the magnetic tape MT with the rotational axis RA3 as the center.

[0315] In the example shown in Fig. 6 , the length of each data recording element DW included in the recording module DWM in the width direction WD, that is, the length L2 is the same as the length LI described above (refer to Fig. 6 ). Also, in the example shown in Fig. 6 , the length of each data reproducing element DR included in the reproducing module DRM in the width direction WD, that is, the length β2 is the same as the length βl described above (refer to Fig. 6 ). Also, the position of the first servo reading element SRa in the width direction WD, the position of the second servo reading element SRb in the width direction WD, and the position of the third servo reading element SRc in the width direction WD are aligned.

[0316] The posture of the first recording module DWMl, the reproducing module DRM, and the second recording module DWM2 with respect to the width direction WD can be fixed or can be changed depending on the situation (e.g., the degree of deformation of the magnetic tape MT, etc.). When the posture of the first recording module DWMl, the reproducing module DRM, and the second recording module DWM2 with respect to the width direction WD is changed, a tilting mechanism (not shown) that operates under the control of the processing device 30 is used. The tilting mechanism is mechanically connected to the first recording module DWMl, the reproducing module DRM, and the second recording module DWM2. In this case, the degree of tilting of the first recording module DWMl, the reproducing module DRM, and the second recording module DWM2 with respect to the width direction WD is adjusted by the tilting mechanism under the control of the processing device 30 depending on the situation.

[0317] For example, the degree of tilting of the first recording module DWMl, the reproducing module DRM, and the second recording module DWM2 with respect to the width direction WD is adjusted by rotating the first recording module DWMl on the surface 31 along the surface 31 with the rotation axis RAl as the center axis, rotating the reproducing module DRM on the surface 31 along the surface 31 with the rotation axis RA2 as the center axis, and rotating the second recording module DWM2 on the surface 31 along the surface 31 with the rotation axis RA3 as the center axis.

[0318] In addition, the example in which the first recording module DWMl, the reproducing module DRM, and the second recording module DWM2 are individually controlled to rotate by the tilting mechanism is given here, but this is only an example, and the entire head 28 can be rotated as a whole with the rotation axis RA2 as the center axis by one tilting mechanism.

[0319] By tilting the recording module DWM and the reproducing module DRM with respect to the width direction WD along the surface 31 of the magnetic tape MT, a predetermined shift is generated in the width direction WD between the position of the first servo reading element SRa in the width direction WD, the position of the second servo reading element SRb in the width direction WD, and the position of the third servo reading element SRc in the width direction WD. In this case, the positions (in other words, the paths P) of the servo patterns 52 read by the first servo reading element SRa, the second servo reading element SRb, and the third servo reading element SRc are adjusted by an amount determined based on the predetermined shift generated in the width direction WD.

[0320] Thus, by arranging the recording module DWM and the reproducing module DRM in a posture inclined with respect to the width direction WD along the surface 31 of the magnetic tape MT, it is possible to suppress a case where the tracking accuracy of the magnetic head 28 to the magnetic tape MT is reduced due to the deformation of the magnetic tape MT. For example, it is possible to suppress a case where data is not recorded at a predetermined position or data cannot be reproduced from a predetermined position due to the deformation of the magnetic tape MT.

[0321] In the above-described embodiment, the tape system 10 in which the tape cartridge 12 is freely insertable and removable with respect to the tape drive 14 is exemplified, but the technology of the present application is not limited thereto. For example, even in a tape system in which at least one tape cartridge 12 is already loaded in the tape drive 14 (i.e., a tape system in which at least one tape cartridge 12 is integrated with the tape drive 14 or the magnetic tape MT is integrated with the tape drive 14 in advance (e.g., before data is recorded on the data tape DB)), the technology of the present application is established. The tape system in which at least one tape cartridge 12 is already loaded in the tape drive 14 is an example of the "tape system" to which the technology of the present application is applied.

[0322] In the above-described embodiment, the single magnetic head 28 is exemplified, but the technology of the present application is not limited thereto. For example, a plurality of magnetic heads 28 can be arranged on the magnetic tape MT.

[0323] As Fig. 6 illustrated, in a case where the recording module DWM and the reproducing module DRM are inclined with respect to the width direction WD along the surface 31 of the magnetic tape MT, in the linear magnetization region pair 54A, the angle formed by the linear magnetization region 54A1 and the servo reading element SR and the angle formed by the linear magnetization region 54A2 and the servo reading element SR are different. Thus, if the angles are different, a deviation (e.g., a deviation in signal level and waveform distortion, etc.) due to the azimuth loss occurs between a servo pattern signal derived from the linear magnetization region 54A1 (i.e., a servo pattern signal obtained by reading the linear magnetization region 54A1 by the servo reading element SR) and a servo pattern signal derived from the linear magnetization region 54A2 (i.e., a servo pattern signal obtained by reading the linear magnetization region 54A2 by the servo reading element SR).

[0324] As Fig. 6 illustrated, in a case where the recording module DWM and the reproducing module DRM are inclined with respect to the width direction WD along the surface 31 of the magnetic tape MT, the angle formed by the servo reading element SR and the linear magnetization region 54A1 (refer to the arrow A1) and the angle formed by the servo reading element SR and the linear magnetization region 54A2 (refer to the arrow A2) are different. Thus, if the angles are different, a deviation (e.g., a deviation in signal level and waveform distortion, etc.) due to the azimuth loss occurs between a servo pattern signal derived from the linear magnetization region 54A1 (i.e., a servo pattern signal obtained by reading the linear magnetization region 54A1 by the servo reading element SR) and a servo pattern signal derived from the linear magnetization region 54A2 (i.e., a servo pattern signal obtained by reading the linear magnetization region 54A2 by the servo reading element SR). Fig. 6) is larger than the angle formed by the servo read element SR and the linear magnetized region 54A2. Consequently, the servo pattern signal output is reduced, and the waveform becomes wider. Consequently, when the magnetic tape MT is traveling, the servo pattern signal read by the servo read element SR across the servo band SB deviates. Furthermore, when the servo read element SR reads the servo pattern 52B, a deviation occurs between the servo pattern signal originating from the linear magnetized region 54B1 and the servo pattern signal originating from the linear magnetized region 54B2 due to azimuth loss. This deviation in the servo pattern signal can cause a decrease in servo control accuracy.

[0325] For example, as another example of a conventionally known servo pattern 52A, a linear magnetized region 54A1 is parallel to the virtual straight line C1, while the linear magnetized region 54A2 is tilted relative to the virtual straight line C1 (i.e., only the linear magnetized region 54A2 is tilted). With this conventionally known method, 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 and the angle formed between the linear magnetized region 54A2 and the servo read element SR in the linear magnetized region pair 54A differ. Such a difference in angles causes a deviation due to azimuth loss between the servo pattern signal from the linear magnetized region 54A1 and the servo pattern signal from the linear magnetized region 54A2. This deviation in the servo pattern signal can cause a decrease in servo control accuracy.

[0326] Therefore, when the recording module DWM and the reproducing module DRM are tilted relative to the width direction WD along the surface 31 of the magnetic tape MT (refer to Fig. 6 ), as an example, Fig. 6 As shown, magnetic tape MT1 is used instead of magnetic tape MT. Unlike magnetic tape MT, magnetic tape MT1 has frames 80 instead of frames 50. Frames 80 are defined by a set of servo patterns 82. A plurality of servo patterns 82 are recorded on servo band SB along the longitudinal direction LD of magnetic tape MT1. Similar to the plurality of servo patterns 52 recorded on magnetic tape MT, the plurality of servo patterns 82 are arranged at predetermined intervals along the longitudinal direction LD of magnetic tape MT.

[0327] exist Fig. 6 In the illustrated example, servo patterns 82A and 82B are shown as an example of a set of servo patterns 82 included in a frame 80. The servo patterns 82A and 82B are adjacent to each other along the longitudinal direction LD of the magnetic tape MT1, and within the frame 80, the servo pattern 82A is located on the upstream side in the positive direction, and the servo pattern 82B is located on the downstream side in the positive direction.

[0328] The servo pattern 82 is composed of line-shaped magnetization region pairs 84. The line-shaped magnetization region pairs 84 can be classified into line-shaped magnetization region pairs 84A and line-shaped magnetization region pairs 84B. Here, the line-shaped magnetization region pairs 84 are an example of the "line-shaped magnetization region pairs" to which the technology of the present application is applied.

[0329] The servo pattern 82A is composed of the line-shaped magnetization region pairs 84A. In the example shown in the drawing, as an example of the line-shaped magnetization region pairs 84A, line-shaped magnetization regions 84A1 and 84A2 are shown. The line-shaped magnetization regions 84A1 and 84A2 are regions that are magnetized in a line shape, respectively. Fig. 6

[0330] The line-shaped magnetization regions 84A1 and 84A2 are inclined in opposite directions with respect to the virtual straight line Cl. In other words, the line-shaped magnetization region 84A1 is inclined in one direction (for example, the clockwise direction when viewed from the paper front side) with respect to the virtual straight line Cl. On the other hand, the line-shaped magnetization region 84A2 is inclined in the other direction (for example, the counterclockwise direction when viewed from the paper front side) with respect to the virtual straight line Cl. The line-shaped magnetization regions 84A1 and 84A2 are not parallel to each other, and are inclined at different angles with respect to the virtual straight line Cl. The line-shaped magnetization region 84A1 is more steeply inclined with respect to the virtual straight line Cl than the line-shaped magnetization region 84A2. Here, "steep" means, for example, that the angle of the line-shaped magnetization region 84A1 with respect to the virtual straight line Cl is smaller than the angle of the line-shaped magnetization region 84A2 with respect to the virtual straight line Cl. Also, the total length of the line-shaped magnetization region 84A1 is shorter than the total length of the line-shaped magnetization region 84A2. Fig. 6 Fig. 6 Here, the line-shaped magnetization region 84A1 is an example of the "first line-shaped magnetization region" to which the technology of the present application is applied, the line-shaped magnetization region 84A2 is an example of the "second line-shaped magnetization region" to which the technology of the present application is applied, and the virtual straight line Cl is an example of the "virtual straight line" to which the technology of the present application is applied.

[0331] In the servo pattern 82A, in the line-shaped magnetization region 84A1, a plurality of magnetization straight lines 84A1a are included, and in the line-shaped magnetization region 84A2, a plurality of magnetization straight lines 84A2a are included. The number of the magnetization straight lines 84A1a included in the line-shaped magnetization region 84A1 is the same as the number of the magnetization straight lines 84A2a included in the line-shaped magnetization region 84A2.

[0332] Here, the line-shaped magnetization region 84A1 is an example of the "first line-shaped magnetization region" to which the technology of the present application is applied, the line-shaped magnetization region 84A2 is an example of the "second line-shaped magnetization region" to which the technology of the present application is applied, and the virtual straight line Cl is an example of the "virtual straight line" to which the technology of the present application is applied.

[0333] ​​The linear magnetization region 84Al is a set of five magnetized straight lines, i.e., magnetized straight lines 84Ala, and the linear magnetization region 84A2 is a set of five magnetized straight lines, i.e., magnetized straight lines 84A2a. Within the servo band SB, in the width direction WD, the positions of the ends of the linear magnetization region 84Al, i.e., the positions of the ends of the five magnetized straight lines 84Ala, respectively, are aligned with the positions of the ends of the linear magnetization region 84A2, i.e., the positions of the ends of the five magnetized straight lines 84A2a, respectively. Note that, here, an example is given in which the positions of the ends of the five magnetized straight lines 84Ala are aligned with the positions of the ends of the five magnetized straight lines 84A2a, but this is merely an example, and as long as the positions of the ends of one or more of the five magnetized straight lines 84Ala are aligned with the positions of the ends of one or more of the five magnetized straight lines 84A2a. Also, in the present specification, the concept of "alignment" includes not only the meaning of complete alignment, but also the meaning of "alignment" including an error that is generally permissible in the technical field to which the technology of the present application pertains, without departing from the technical concept of the present application.

[0334] The servo pattern 82B is composed of a pair of linear magnetization regions 84B. In the example shown in FIG. 8B, a pair of linear magnetization regions 84B1 and 84B2 are shown as an example of a pair of linear magnetization regions 84B. The linear magnetization regions 84B1 and 84B2 are regions that are magnetized linearly, respectively. Fig. 6

[0335] The linear magnetization regions 84B1 and 84B2 are inclined in opposite directions with respect to the virtual straight line C2. In other words, the linear magnetization region 84B1 is inclined in one direction (e.g., the clockwise direction when viewed from the paper front side) with respect to the virtual straight line C2. On the other hand, the linear magnetization region 84B2 is inclined in the other direction (e.g., the counterclockwise direction when viewed from the paper front side) with respect to the virtual straight line C2. The linear magnetization regions 84B1 and 84B2 are not parallel to each other, and are inclined at different angles with respect to the virtual straight line C2. The linear magnetization region 84B1 is more steeply inclined with respect to the virtual straight line C2 than the linear magnetization region 84B2. Here, "steeper" means, for example, that the angle of the linear magnetization region 84B1 with respect to the virtual straight line C2 is smaller than the angle of the linear magnetization region 84B2 with respect to the virtual straight line C2. Also, the total length of the linear magnetization region 84B1 is shorter than the total length of the linear magnetization region 84B2. Fig. 6 Fig. 6 The linear magnetization region 84Al is a set of five magnetized straight lines, i.e., magnetized straight lines 84Ala, and the linear magnetization region 84A2 is a set of five magnetized straight lines, i.e., magnetized straight lines 84A2a. Within the servo band SB, in the width direction WD, the positions of the ends of the linear magnetization region 84Al, i.e., the positions of the ends of the five magnetized straight lines 84Ala, respectively, are aligned with the positions of the ends of the linear magnetization region 84A2, i.e., the positions of the ends of the five magnetized straight lines 84A2a, respectively. Note that, here, an example is given in which the positions of the ends of the five magnetized straight lines 84Ala are aligned with the positions of the ends of the five magnetized straight lines 84A2a, but this is merely an example, and as long as the positions of the ends of one or more of the five magnetized straight lines 84Ala are aligned with the positions of the ends of one or more of the five magnetized straight lines 84A2a. Also, in the present specification, the concept of "alignment" includes not only the meaning of complete alignment, but also the meaning of "alignment" including an error that is generally permissible in the technical field to which the technology of the present application pertains, without departing from the technical concept of the present application.

[0336] ​​Here, the linear magnetization region 84B1 is an example of the "first linear magnetization region" according to the technology of the present application, the linear magnetization region 84B2 is an example of the "second linear magnetization region" according to the technology of the present application, and the virtual straight line C2 is an example of the "virtual straight line" according to the technology of the present application.

[0337] In the servo pattern 82B, in the linear magnetization region 84B1, a plurality of magnetized straight lines 84B1a are included, and in the linear magnetization region 84B2, a plurality of magnetized straight lines 84B2a are included. The number of the magnetized straight lines 84B1a included in the linear magnetization region 84B1 is the same as the number of the magnetized straight lines 84B2a included in the linear magnetization region 84B2.

[0338] The total number of the magnetized straight lines 84B1a and 84B2a included in the servo pattern 82B is different from the total number of the magnetized straight lines 84A1a and 84A2a included in the servo pattern 82A. In the servo pattern 82B, the total number of the magnetized straight lines 84B1a and 84B2a is smaller than the total number of the magnetized straight lines 84A1a and 84A2a. Fig. 6 In the example shown in the drawing, the total number of the magnetized straight lines 84A1a and 84A2a included in the servo pattern 82A is 10, and in contrast, the total number of the magnetized straight lines 84B1a and 84B2a included in the servo pattern 82B is 8.

[0339] The linear magnetization region 84B1 is a set of 4 magnetized straight lines, i.e., the magnetized straight lines 84B1a, and the linear magnetization region 84B2 is a set of 4 magnetized straight lines, i.e., the magnetized straight lines 84B2a. In the servo band SB, in the width direction WD, the positions of the two ends of the linear magnetization region 84B1, i.e., the positions of the two ends of each of the 4 magnetized straight lines 84B1a, and the positions of the two ends of the linear magnetization region 84B2, i.e., the positions of the two ends of each of the 4 magnetized straight lines 84B2a, are aligned.

[0340] In addition, here, an example in which the positions of the two ends of each of the 4 magnetized straight lines 84B1a and the positions of the two ends of each of the 4 magnetized straight lines 84B2a are aligned is presented, but this is only an example. For example, the technology of the present application is established as long as the positions of the two ends of one or more of the 4 magnetized straight lines 84B1a and the positions of the two ends of one or more of the 4 magnetized straight lines 84B2a are aligned.

[0341] Also, as an example of the linear magnetization region 84Al, a set of five magnetized straight lines, i.e., magnetized straight lines 84Ala, is cited, and as an example of the linear magnetization region 84A2, a set of five magnetized straight lines, i.e., magnetized straight lines 84A2a, is cited, but the technology of the present application is not limited to this. Also, as an example of the linear magnetization region 84Bl, a set of four magnetized straight lines, i.e., magnetized straight lines 84Bla, is cited, and as an example of the linear magnetization region 84B2, a set of four magnetized straight lines, i.e., magnetized straight lines 84B2a, is cited, but the technology of the present application is not limited to this. For example, as long as the linear magnetization region 84Al is a plurality of magnetized straight lines 84Ala that contribute to the determination of the position of the magnetic head 28 on the magnetic tape MTl, and the linear magnetization region 84A2 is a plurality of magnetized straight lines 84A2a that contribute to the determination of the position of the magnetic head 28 on the magnetic tape MTl, the technology of the present application is established. Also, as long as the linear magnetization region 84Bl is a plurality of magnetized straight lines 84Bla that contribute to the determination of the position of the magnetic head 28 on the magnetic tape MTl, and the linear magnetization region 84B2 is a plurality of magnetized straight lines 84B2a that contribute to the determination of the position of the magnetic head 28 on the magnetic tape MTl, the technology of the present application is established.

[0342] Here, with reference to Fig. 6 , the geometric characteristics of the linear magnetization region pair 84A on the magnetic tape MTl are described. Also, here, the geometric characteristics refer to the geometric characteristics generally understood as length, shape, direction, and / or position, etc.

[0343] As an example, as shown in Fig. 6 , the geometric characteristics of the linear magnetization region pair 84A on the magnetic tape MTl can be expressed using a virtual linear region pair 86. The virtual linear region pair 86 is composed of a virtual linear region 86A and a virtual linear region 86B. The geometric characteristics of the linear magnetization region pair 84A on the magnetic tape MTl correspond to the geometric characteristics of the virtual linear region pair 86 based on tilting the entire virtual linear region pair 86 with respect to the virtual straight line Cl by tilting the symmetric axis SA1 of the virtual linear region 86A and the virtual linear region 86B, which are symmetric with respect to the virtual straight line Cl, with respect to the virtual straight line Cl.

[0344] The virtual linear region pair 86 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 86 is a virtual magnetization region used for the convenience of describing the geometric characteristics of the linear magnetization region 86Al on the magnetic tape MTl, and is not an actually existing magnetization region.

[0345] The virtual linear region 86A has the same geometric characteristics as the linear magnetization region 54Al shown in Fig. 6 , and is composed of a plurality of magnetized straight lines 86Ala that contribute to the determination of the position of the magnetic head 28 on the magnetic tape MTl. Also, the virtual linear region 86B has the same geometric characteristics as the linear magnetization region 54A2 shown in Fig. 6The five imaginary straight lines 86A1 corresponding to the five magnetization straight lines 54A1a are shown. Fig. 6 The linear magnetized region 54B1 has the same geometric characteristics as the Fig. 6 The five magnetization straight lines 54A2a shown are composed of five virtual straight lines 86B1 corresponding to each other.

[0346] A center O1 is provided on the virtual linear region pair 86. For example, the center O1 is the center of a line segment 88 connecting the center of the most upstream straight line 86A1 among the five straight lines 86A1 and the center of the most downstream straight line 86B1 among the five straight lines 86B1.

[0347] The virtual linear region pair 86 has the same Fig. 6 Since the linear magnetized region pair 54A shown in FIG. 1 has the same geometric characteristics, the virtual linear region 86A and the virtual linear region 86B are tilted in a line-symmetrical manner with respect to the virtual straight line C1. Here, consider the virtual linear region pair 86 when the entire virtual linear region pair 86 is tilted with respect to the virtual straight line C1 as follows. Assume that Fig. 6 In the illustrated example of reading by the servo read element SR, the symmetry axis SA1 of the virtual linear regions 86A and 86B is tilted at an angle a (e.g., 10 degrees) relative to the virtual straight line C1, with the center O1 as the rotation axis. In this case, within the virtual linear region pair 86, there may be locations in the width direction WD where the virtual linear region 86A is read but the virtual linear region 86B is not, or where the virtual linear region 86A is not read but the virtual linear region 86B is. In other words, in each of the virtual linear regions 86A and 86B, reading by the servo read element SR results in insufficient or unnecessary portions.

[0348] Therefore, the insufficient portions are supplemented and the unnecessary portions are removed in each of the virtual linear regions 86A and 86B. As a result, the positions of the two ends of the virtual linear region 86A (i.e., the positions of the two ends of the five straight lines 86A1) and the two ends of the virtual linear region 86B (i.e., the positions of the two ends of the five straight lines 86B1) are aligned in the width direction WD.

[0349] The geometric characteristics of the virtual linear region pair 86 thus obtained (i.e., the geometric characteristics of the virtual servo pattern) correspond to the geometric characteristics of the actual servo pattern 82A. Specifically, the servo band SB includes a pair of linear magnetized regions 84A having geometric characteristics corresponding to the geometric characteristics of the virtual linear region pair 86, where the positions of the ends of the virtual linear region 86A and the ends of the virtual linear region 86B are aligned in the width direction WD.

[0350] Further, the linear magnetization region pair 84B differs from the linear magnetization region pair 84A only in that four linear magnetization lines 84Bla are provided instead of the five linear magnetization lines 84Ala, and four linear magnetization lines 84B2a are provided instead of the five linear magnetization lines 84A2a. Therefore, on the servo band SB, the linear magnetization region pair 84B having the geometrical characteristics corresponding to the geometrical characteristics of the virtual linear region pair (not shown) is recorded, which is obtained by aligning the positions of the two ends of each of the four lines 86Al with the positions of the two ends of each of the four lines 86Bl in the width direction WD.

[0351] Thus, in the case where the recording module DWM and the reproducing module DRM are inclined with respect to the width direction WD along the surface 31 of the magnetic tape MT (refer to FIG. 1), the magnetic tape MTl in which the servo pattern 82A composed of the linear magnetization region pair 84A and the servo pattern 82B composed of the linear magnetization region pair 84B are formed is used. Thereby, even in the case where the head 28 that is inclined on the magnetic tape MTl records data on the magnetic tape MTl or reproduces data from the magnetic tape MTl in order to reduce the influence of the TDS, it is possible to contribute to improvement in the accuracy of recording data on the magnetic tape MTl and the accuracy of reproducing data recorded on the magnetic tape MTl. Fig. 6

[0352] Further, the straightness detection method (refer to FIG. 2) is also performed on the magnetic tape MTl in the same manner as in the above-described embodiment. Thereby, the straightness of the servo pattern 82 is ensured. Therefore, the same effects as in the above-described embodiment are obtained. Fig. 6

[0353] Further, instead of the servo pattern recording head WH, a skew-corresponding servo pattern recording head (not shown) is used to form the plurality of servo bands SB each including a plurality of servo patterns 82 along the long direction LD in the same manner as in the above-described embodiment. The skew-corresponding servo pattern recording head refers to a servo pattern recording head in which, for example, a plurality of gap patterns having geometrical characteristics corresponding to the geometrical characteristics of the line 86Al located at the most upstream side in the positive direction within the virtual linear region 86A and the line 86Bl located at the most upstream side in the positive direction within the virtual linear region 86B are formed at equal intervals along the direction WD3 (refer to FIG. 3). Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig. 6 Fig

[0354] ​​​The above-described contents and drawings are detailed descriptions of the technical aspects of the present application, and are merely examples of the technical aspects of the present application. For example, the descriptions related to the above-described structures, functions, effects, and the like are descriptions related to examples of the structures, functions, effects, and the like of the technical aspects of the present application. Therefore, it is needless to say that, within the scope of the gist of the technical aspects of the present application, the above-described contents and drawings can be modified by deleting unnecessary parts, or adding or replacing new elements. Also, in order to avoid confusion and facilitate understanding of the technical aspects of the present application, the above-described contents and drawings omit descriptions related to technical common knowledge and the like that do not need to be particularly described in order to implement the technical aspects of the present application.

[0355] In the present specification, the meaning of "A and / or B" is the same as "at least one of A and B". That is, "A and / or B" means that only A can be included, only B can be included, or both A and B can be included. Also, in the present specification, the same consideration method as "A and / or B" can be applied when three or more cases are connected by "and / or".

[0356] All documents, patent applications, and technical standards cited in the present specification are each hereby expressly incorporated by reference as of the date of the present application to the same extent as if each was specifically and individually indicated to be incorporated by reference. All documents, patent applications, and technical standards cited in the present specification are each hereby expressly incorporated by reference as of the date of the present application to the same extent as if each was specifically and individually indicated to be incorporated by reference.

Claims

1. A magnetic tape, which is a magnetic tape in which a plurality of servo bands each of which has a plurality of servo patterns recorded along a longitudinal direction are arranged in a width direction, wherein an index indicating a non-linearity of the servo patterns is controlled to be 15% or less of a track pitch, the track pitch is a pitch between a plurality of tracks formed by recording data on the magnetic tape by a recording element in accordance with a signal obtained from the plurality of servo patterns, the index indicates a degree of deviation between a plurality of PES difference gaps and an average value of the plurality of PES difference gaps, the PES difference gap is a difference between a first PES difference and a second PES difference, the first PES difference is a difference in PES between a pair of first positions corresponding in the width direction in a pair of servo patterns recorded between a pair of servo bands adjacent in the width direction among the plurality of servo bands and at positions corresponding in the width direction, the second PES difference is a difference in PES between a pair of second positions offset from the pair of first positions by a first predetermined interval in the width direction in the pair of servo patterns, the plurality of PES difference gaps are obtained by measuring the PES difference gap in the pair of servo patterns at every second predetermined interval in the width direction, the first predetermined interval is larger than the second predetermined interval.

2. The magnetic tape according to claim 1, wherein the plurality of tracks are formed by recording the data on the magnetic tape by the recording element in an SMR manner.

3. The magnetic tape according to claim 1, wherein the index is a value corresponding to 3 times a standard deviation of the plurality of PES difference gaps.

4. The magnetic tape according to claim 1, wherein the first predetermined interval is an interval closest to a reference interval which is a natural number times of the second predetermined interval and which corresponds to half of a difference between a recording element length which is a length of the recording element in the width direction and the track pitch.

5. The magnetic tape according to claim 1, wherein the first predetermined interval is an interval corresponding to 2 or more times of the second predetermined interval.

6. The magnetic tape according to claim 1, wherein the first predetermined interval is larger than the track pitch.

7. The magnetic tape according to claim 1, wherein the index is controlled to be 10% or less of the track pitch.

8. The magnetic tape according to claim 1, wherein the index is controlled to be 5% or less of the track pitch.

9. The magnetic tape according to claim 1, wherein on the magnetic tape, there are 3 or more servo bands arranged in the width direction as the plurality of servo bands, the index is obtained for each of all the pairs of servo bands adjacent in the width direction.

10. The magnetic tape according to claim 9, wherein the index obtained for each of the pairs of servo bands is controlled to be 15% or less of the track pitch, respectively.

11. The magnetic tape according to claim 9, wherein the index obtained for each of the pairs of servo bands is controlled to be 10% or less of the track pitch, respectively. ​ 12. The magnetic tape according to claim 9, wherein the index obtained for each of the pair of servo bands is controlled to be 5% or less of the track pitch, respectively.

13. The magnetic tape according to claim 1, wherein the servo pattern is at least one pair of linearly magnetized regions, the pair of linearly magnetized regions is a first linearly magnetized region magnetized in a line and a second linearly magnetized region magnetized in a line, the first linearly magnetized region and the second linearly magnetized region are inclined in opposite directions with respect to a virtual straight line along the width direction, the first linearly magnetized region is more steeply inclined with respect to the virtual straight line than the second linearly magnetized region.

14. A magnetic tape cartridge comprising: the magnetic tape according to any one of claims 1 to 13; and a case in which the magnetic tape is accommodated.

15. A magnetic tape system comprising: the magnetic tape according to any one of claims 1 to 13; and a magnetic head that records data on the magnetic tape and / or reproduces data recorded on the magnetic tape.

16. A detection method comprising the steps of: a step of obtaining the index from the magnetic tape according to any one of claims 1 to 13; and a step of detecting the magnetic tape using the index.

17. The detection method according to claim 16, wherein the step of detecting the magnetic tape includes a step of detecting straightness of the servo pattern using the index.

18. A manufacturing method of a magnetic tape in which a plurality of servo bands in which a plurality of servo patterns are respectively recorded along a first longitudinal direction are arranged along a width direction, the manufacturing method of the magnetic tape comprising the steps of: a step of disposing a servo write head in a posture in which a recording surface faces a plurality of gap patterns, the servo write head having: an opposing surface that faces the recording surface of the magnetic tape when the plurality of servo patterns are recorded along the first longitudinal direction; and the plurality of gap patterns that are formed at intervals along a second longitudinal direction of the opposing surface and correspond to the plurality of servo patterns, respectively; and a step of recording the plurality of servo patterns on the recording surface along the first longitudinal direction using the servo write head disposed in the posture, thereby forming the plurality of servo bands on the recording surface, an index indicating non-straightness of the servo pattern is controlled to be 15% or less of a track pitch, the track pitch is a pitch between a plurality of tracks formed by recording data on the magnetic tape by a recording element based on a signal obtained from the plurality of servo patterns, the index indicates a degree of deviation between a plurality of PES difference gaps and an average value of the plurality of PES difference gaps, the index indicates a degree of deviation between a plurality of PES difference gaps and an average value of the plurality of PES difference gaps, The PES difference gap is a difference between a first PES difference and a second PES difference, the first PES difference being a difference in PES between a pair of first positions corresponding in the width direction in a pair of servo patterns recorded between a pair of servo bands adjacent in the width direction among the plurality of servo bands and at corresponding positions in the width direction, the second PES difference being a difference in PES between a pair of second positions offset from the pair of first positions by a first predetermined interval in the width direction in the pair of servo patterns, The plurality of PES difference gaps are obtained by measuring the PES difference gap at every second predetermined interval in the width direction in the pair of servo patterns, The first predetermined interval is larger than the second predetermined interval.

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