Magnetic tape cartridge, magnetic tape drive, servo pattern detection method, and program

Abstract

To provide a magnetic tape cartridge, a magnetic tape drive, a method of detecting servo patterns, and a program for obtaining a highly reliable servo signal.SOLUTION: In a magnetic tape drive 14, a magnetic tape cartridge 12 includes a magnetic tape MT on which a plurality of servo patterns 58 are recorded in a longitudinal direction and a cartridge memory 24, which is an example of a storage medium. The storage medium stores servo format information SF including servo pattern inclination information SF1 which is information relating to the inclination of the servo pattern with respect to a first virtual straight line.SELECTED DRAWING: Figure 14

Description

[Technical Field]

[0001] The technology of the present disclosure relates to a magnetic tape cartridge, a magnetic tape drive, a servo pattern detection method, and a program. [Background technology]

[0002] Patent Document 1 discloses providing a complete synchronous servo channel for a data tape drive by including initial acquisition of synchronous servo channel parameters, generation of a timing reference for signal interpolation, generation of tape velocity and y-position estimates, and optimal detection of longitudinal position (LPOS) symbols.

[0003] Patent document 2 discloses an apparatus including at least two modules, each having an array of transducers, the at least two modules being fixed relative to each other, the axis of each array being defined between its two ends, the array axes being oriented approximately parallel to each other, the array of a first module being offset from the array of a second module in a first direction parallel to the axis of the array of the second module, so that the transducers of the first module are approximately aligned with the transducers of the second module in the intended direction of tape movement when the axis is oriented at an angle greater than 0.2° with respect to a line oriented perpendicular to the intended direction of tape movement, and a mechanism for orienting the modules to control the transducer pitch presented to the tape. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] U.S. Patent No. 7,365,929 [Patent Document 2] U.S. Patent No. 9,754,616 Summary of the Invention

[0005] One embodiment of the technique of the present disclosure provides a magnetic tape cartridge, a magnetic tape drive, a servo pattern detection method, and a program that are capable of obtaining a highly reliable servo pattern signal. [Means for solving the problem]

[0006] A first aspect of the technology disclosed herein is a magnetic tape cartridge comprising a magnetic tape having a plurality of servo patterns recorded along the longitudinal direction and a storage medium, wherein the storage medium stores servo format information including servo pattern inclination information, which is information regarding the inclination of the servo pattern relative to a first virtual straight line.

[0007] A second aspect of the technology disclosed herein is a magnetic tape cartridge according to the first aspect, in which the first virtual straight line is a straight line along the width direction of the magnetic tape, the servo pattern is at least one pair of linear magnetization regions, the pair of linear magnetization regions being a linearly magnetized first linear magnetization region and a linearly magnetized second linear magnetization region, the first linear magnetization region and the second linear magnetization region are inclined in opposite directions relative to the first virtual straight line, the first linear magnetization region has a steeper inclination angle relative to the first virtual straight line than the second linear magnetization region, and the servo pattern inclination information includes information regarding the inclination angle of the first linear magnetization region relative to the first virtual straight line and information regarding the inclination angle of the second linear magnetization region relative to the first virtual line.

[0008] A third aspect of the disclosed technology is a magnetic tape cartridge according to the second aspect, in which the positions of both ends of the first linear magnetization region and the positions of both ends of the second linear magnetization region are aligned in the width direction of the magnetic tape.

[0009] A fourth aspect of the technique of the present disclosure is the magnetic tape cartridge according to the third aspect, in which the total length of the first linear magnetization region is shorter than the total length of the second linear magnetization region.

[0010] A fifth aspect of the technology disclosed herein is a magnetic tape cartridge according to any one of the second to fourth aspects, in which the first linear magnetization region is a collection of multiple first magnetization lines and the second linear magnetization region is a collection of multiple second magnetization lines.

[0011] A sixth aspect of the technology of the present disclosure is a magnetic tape cartridge according to any one of the second to fifth aspects, in which the geometric characteristics of the pair of linear magnetized regions on the magnetic tape correspond to the geometric characteristics based on the pair of virtual linear regions when the entire pair of virtual linear regions is tilted relative to the first virtual line by tilting the symmetry axes of the pair of virtual linear regions that are tilted line-symmetrically relative to the first virtual line with respect to the first virtual line.

[0012] A seventh aspect of the technology of the present disclosure is a magnetic tape cartridge according to any one of the third aspect, the fourth aspect, and the fifth aspect according to the third or fourth aspect, in which the geometric characteristics of the pair of linear magnetized regions on the magnetic tape correspond to geometric characteristics in which the positions of both ends of one of the pair of virtual linear regions and the positions of both ends of the other virtual linear region are aligned in the width direction when the symmetry axes of the pair of virtual linear regions tilted linearly symmetrically with respect to a first virtual line are tilted with respect to the first virtual line, thereby tilting the entire pair of virtual linear regions with respect to the first virtual line.

[0013] An eighth aspect of the technology disclosed herein is a magnetic tape cartridge according to any one of the first to seventh aspects, in which the servo format information includes an ideal waveform signal indicating an ideal waveform of a servo pattern signal that is the result of the servo pattern being read by a servo read element.

[0014] A ninth aspect of the technique of the present disclosure is the magnetic tape cartridge according to the eighth aspect, in which the ideal waveform is a waveform determined according to the orientation of the servo read element on the magnetic tape.

[0015] A tenth aspect of the disclosed technique is a magnetic tape cartridge according to the ninth aspect, in which the ideal waveform is a waveform determined according to the geometric characteristics of the servo pattern and the orientation of the servo read element on the magnetic tape.

[0016] An eleventh aspect of the technology of the present disclosure is a magnetic tape cartridge according to the eighth aspect, in which the servo read element is mounted on a magnetic head and the ideal waveform is a waveform determined according to the orientation of the magnetic head on the magnetic tape.

[0017] A twelfth aspect of the technology of the present disclosure is a magnetic tape cartridge according to the eleventh aspect, in which the ideal waveform is a waveform determined according to the geometric characteristics of the servo pattern and the orientation of the magnetic head on the magnetic tape.

[0018] A thirteenth aspect of the disclosed technology is a magnetic tape cartridge according to any one of the first to twelfth aspects, in which the servo format information includes information regarding the width of the magnetic tape and / or information regarding the geometric characteristics of the servo pattern.

[0019] A fourteenth aspect of the technique of the present disclosure is a magnetic tape cartridge according to any one of the first to thirteenth aspects, in which the servo format information includes width adjustment information for adjusting the width of the magnetic tape.

[0020] A fifteenth aspect of the technique of the present disclosure is the magnetic tape cartridge according to the fourteenth aspect, in which the width adjustment information includes information relating to the tension in the overall length direction of the magnetic tape.

[0021] A sixteenth aspect of the technology of the present disclosure is a magnetic tape cartridge according to the fifteenth aspect, in which the information regarding tension is determined according to the width of the magnetic tape, the characteristics of the magnetic tape itself, the usage history of the magnetic tape, the temperature applied to the magnetic tape, and / or the humidity applied to the magnetic tape.

[0022] A seventeenth aspect of the technology of the present disclosure is a magnetic tape cartridge according to any one of the first to sixteenth aspects, in which the servo format information includes information regarding a skew angle, which is the angle at which a magnetic head equipped with a servo read element that reads a servo pattern is skewed on the magnetic tape.

[0023] An 18th aspect of the technology of the present disclosure is a magnetic tape cartridge according to the 17th aspect, in which the information regarding the skew angle is determined according to the width of the magnetic tape, the characteristics of the magnetic tape itself, the usage history of the magnetic tape, the temperature applied to the magnetic tape, and / or the humidity applied to the magnetic tape.

[0024] A 19th aspect of the technology of the present disclosure is a magnetic tape cartridge according to any one of the first to eighteenth aspects, in which the magnetic tape is housed in a cartridge, and the cartridge is provided with a non-contact storage medium as a storage medium.

[0025] A twentieth aspect of the technique of the present disclosure is the magnetic tape cartridge according to any one of the first to eighteenth aspects, in which the storage medium is a magnetic tape.

[0026] A 21st aspect of the technology of the present disclosure is a magnetic tape drive that includes a processor, the processor acquiring servo format information stored in a storage medium provided in a magnetic tape cartridge according to any one of the first to 20th aspects, and performing processing according to the acquired servo format information.

[0027] A 22nd aspect of the technology of the present disclosure is a method for detecting a servo pattern, which includes acquiring servo format information stored in a storage medium provided in a magnetic tape cartridge having a magnetic tape on which multiple servo patterns are recorded along the longitudinal direction, and including servo pattern inclination information which is information regarding the inclination of the servo pattern relative to a first virtual line, and performing processing according to the acquired servo format information.

[0028] A 23rd aspect of the technology of the present disclosure is a program for causing a computer to execute processing including acquiring servo format information stored in a storage medium provided in a magnetic tape cartridge having a magnetic tape on which multiple servo patterns are recorded along the longitudinal direction, and including servo pattern inclination information which is information regarding the inclination of the servo pattern relative to a first virtual line, and executing processing according to the acquired servo format information. [Brief explanation of the drawings]

[0029] [Figure 1] 1 is a block diagram showing an example of the configuration of a magnetic tape system according to an embodiment; [Figure 2] 1 is a schematic perspective view showing an example of the appearance of a magnetic tape cartridge according to an embodiment. [Figure 3] FIG. 1 is a schematic diagram illustrating an example of a hardware configuration of a magnetic tape drive according to an embodiment. [Figure 4] 1 is a schematic perspective view showing an example of a magnetic field emitted by a non-contact read / write device from the bottom side of a magnetic tape cartridge according to an embodiment. FIG. [Figure 5] FIG. 1 is a schematic diagram illustrating an example of a hardware configuration of a magnetic tape drive according to an embodiment. [Figure 6] FIG. 1 is a conceptual diagram showing an example of a state in which a magnetic head is disposed on a conventionally known magnetic tape, as observed from the surface side of the magnetic tape. [Figure 7] 1A and 1B are conceptual diagrams showing an example of a conventionally known magnetic tape observed from the surface side of the magnetic tape before and after the width of the magnetic tape is reduced. [Figure 8] FIG. 1 is a conceptual diagram showing an example of a state in which a magnetic head is skewed on a conventionally known magnetic tape, as observed from the surface side of the magnetic tape. [Figure 9] 1 is a conceptual diagram showing an example of a magnetic tape according to an embodiment, observed from the surface side of the magnetic tape. [Figure 10]FIG. 10 is a conceptual diagram showing an example of the relationship between the geometric characteristics of an actual servo pattern and the geometric characteristics of a virtual servo pattern. [Figure 11] FIG. 10 is a conceptual diagram showing an example of an inclination angle of an actual servo pattern. [Figure 12] 1 is a conceptual diagram showing an example of a state in which a servo pattern is read by a servo read element included in a magnetic head that is not skewed on a magnetic tape according to an embodiment, observed from the surface side of the magnetic tape. [Figure 13] 1 is a conceptual diagram showing an example of a state in which a servo pattern is read by a servo read element included in a magnetic head skewed above a magnetic tape according to an embodiment, observed from the surface side of the magnetic tape. [Figure 14] FIG. 2 is a conceptual diagram illustrating an example of functions of a control device included in the magnetic tape drive according to the embodiment. [Figure 15] 1 is a conceptual diagram showing an example of a state in which a servo pattern is read by a servo read element included in a magnetic head skewed above a magnetic tape according to an embodiment, observed from the surface side of the magnetic tape. [Figure 16] FIG. 2 is a conceptual diagram illustrating an example of functions of a control device included in the magnetic tape drive according to the embodiment. [Figure 17] 2 is a conceptual diagram showing an example of functions of a control unit and a position detection unit of a control device included in a magnetic tape drive according to an embodiment. FIG. [Figure 18] FIG. 2 is a conceptual diagram showing an example of the configuration of a servo writer according to the embodiment. [Figure 19] 10 is a flowchart illustrating an example of the flow of a servo pattern detection process according to the embodiment. [Figure 20] FIG. 10 is a conceptual diagram showing a first modified example, illustrating an example of the functions of a control unit and a PES calculation unit of a control device included in a magnetic tape drive according to an embodiment. [Figure 21] FIG. 10 is a conceptual diagram showing a second modified example, illustrating an example of a mode in which servo format information is stored in a cartridge memory. [Figure 22]FIG. 10 is a conceptual diagram showing a third modified example, illustrating an example of functions of a control device included in a magnetic tape drive according to an embodiment. [Figure 23] FIG. 10 is a conceptual diagram showing a third modified example, illustrating an example of a mode in which servo format information is stored in a cartridge memory. [Figure 24] FIG. 10 is a conceptual diagram showing a third modified example, illustrating an example of a mode in which servo format information is stored in a cartridge memory. [Figure 25] FIG. 10 is a conceptual diagram showing a fourth modified example, illustrating an example of functions of a control device included in a magnetic tape drive according to an embodiment. [Figure 26] FIG. 10 is a conceptual diagram showing a fourth modified example, illustrating an example of a mode in which servo format information is stored in the cartridge memory. [Figure 27] FIG. 10 is a conceptual diagram showing a fifth modified example, illustrating an example of the functions of a control unit and an angle detection unit of a control device included in a magnetic tape drive according to an embodiment. [Figure 28] FIG. 10 is a conceptual diagram showing a fifth modified example, illustrating an example of the function of an angle detection unit of a control device included in a magnetic tape drive according to an embodiment. [Figure 29] FIG. 10 is a conceptual diagram showing a fifth modified example, illustrating an example of the functions of a control unit and a PES calculation unit of a control device included in a magnetic tape drive according to an embodiment. [Figure 30] This is a conceptual diagram showing a sixth modified example, and a conceptual diagram showing a modified example of the magnetic tape according to the embodiment (a conceptual diagram showing an example of the magnetic tape observed from the surface side of the magnetic tape). [Figure 31] FIG. 13 is a conceptual diagram showing a sixth modified example, illustrating an example of a form of a servo pattern included in a magnetic tape. [Figure 32] This is a conceptual diagram showing a seventh modified example, and a conceptual diagram showing a modified example of the magnetic tape according to the embodiment (a conceptual diagram showing an example of the magnetic tape observed from the surface side of the magnetic tape). [Figure 33]FIG. 13 is a conceptual diagram showing a seventh modified example, illustrating an example of a mode of a servo pattern included in a magnetic tape. [Figure 34] This is a conceptual diagram showing an eighth modified example, a conceptual diagram showing a modified example of the magnetic tape according to the embodiment (a conceptual diagram showing an example of the magnetic tape observed from the surface side of the magnetic tape). [Figure 35] FIG. 13 is a conceptual diagram showing an eighth modified example, illustrating an example of the relationship between the geometric characteristics of an actual servo pattern and the geometric characteristics of a virtual servo pattern. [Figure 36] This is a conceptual diagram showing the eighth modified example, which is a conceptual diagram showing an example of the state in which a servo pattern is read by a servo read element included in a magnetic head skewed above the magnetic tape, observed from the surface side of the magnetic tape. [Figure 37] This is a conceptual diagram showing a ninth modified example, and is a conceptual diagram showing a modified example of the magnetic tape according to the embodiment (a conceptual diagram showing an example of the magnetic tape observed from the surface side of the magnetic tape). [Figure 38] FIG. 13 is a conceptual diagram showing a ninth modified example, illustrating an example of a mode of a servo pattern included in a magnetic tape. [Figure 39] This is a conceptual diagram showing the tenth modified example, a conceptual diagram showing a modified example of the magnetic tape according to the embodiment (a conceptual diagram showing an example of the magnetic tape observed from the surface side of the magnetic tape). [Figure 40] FIG. 20 is a conceptual diagram showing a tenth modified example, illustrating an example of the form of a servo pattern included in a magnetic tape. [Figure 41] FIG. 23 is a conceptual diagram showing an eleventh modified example, illustrating an example of a mode in which servo format information is stored on a magnetic tape. [Figure 42] FIG. 23 is a conceptual diagram showing a twelfth modified example, illustrating an example of the form of a servo pattern included in a magnetic tape. [Figure 43] FIG. 10 is a conceptual diagram showing an example of how a servo pattern detection program stored in a storage medium is installed in a computer of a control device. DETAILED DESCRIPTION OF THE INVENTION

[0030] Hereinafter, exemplary embodiments of a magnetic tape cartridge, a magnetic tape drive, and a servo pattern detection method according to the techniques of the present disclosure will be described with reference to the accompanying drawings.

[0031] First, the terms used in the following description will be explained.

[0032] NVM is an abbreviation for "Non-volatile memory". CPU is an abbreviation for "Central Processing Unit". RAM is an abbreviation for "Random Access Memory". EEPROM is an abbreviation for "Electrically Erasable and Programmable Read Only Memory". SSD is an abbreviation for "Solid State Drive". HDD is an abbreviation for "Hard Disk Drive". ASIC is an abbreviation for "Application Specific Integrated Circuit". FPGA is an abbreviation for "Field-Programmable Gate Array". PLC is an abbreviation for "Programmable Logic Controller". IC is an abbreviation for "Integrated Circuit". RFID is an abbreviation for "Radio Frequency Identifier". BOT is an abbreviation for "Beginning Of Tape". EOT is an abbreviation for "End Of Tape". UI is an abbreviation for "User Interface". WAN is an abbreviation for "Wide Area Network". LAN is an abbreviation for "Local Area Network." PES is an abbreviation for "Position Error Signal."

[0033] As an example, as shown in Figure 1, a magnetic tape system 10 includes a magnetic tape cartridge 12 and a magnetic tape drive 14. The magnetic tape cartridge 12 is loaded into the magnetic tape drive 14. The magnetic tape cartridge 12 contains a magnetic tape MT. The magnetic tape drive 14 pulls out the magnetic tape MT from the loaded magnetic tape cartridge 12 and, while running the pulled-out magnetic tape MT, records data on the magnetic tape MT and reads data from the magnetic tape MT.

[0034] In this embodiment, the magnetic tape drive 14 is an example of a "magnetic tape drive" according to the technology of the present disclosure. The magnetic tape cartridge 12 is an example of a "magnetic tape cartridge" according to the technology of the present disclosure. The magnetic tape MT is an example of a "magnetic tape" according to the technology of the present disclosure.

[0035] Next, an example of the configuration of the magnetic tape cartridge 12 will be described with reference to Figures 2 to 4. In the following description, for convenience of explanation, the loading direction of the magnetic tape cartridge 12 into the magnetic tape drive 14 is indicated by arrow A in Figures 2 to 4, the direction of arrow A is the front direction of the magnetic tape cartridge 12, and the front side of the magnetic tape cartridge 12 is the front side of the magnetic tape cartridge 12. In the following description of the structure, "front" refers to the front side of the magnetic tape cartridge 12.

[0036] 2 to 4, for convenience of explanation, the direction of arrow B, which is perpendicular to the direction of arrow A, is defined as the right direction, and the right side of the magnetic tape cartridge 12 is defined as the right side of the magnetic tape cartridge 12. In the following description of the structure, "right" refers to the right side of the magnetic tape cartridge 12.

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

[0038] 2 to 4, for convenience of explanation, the direction perpendicular to the directions of arrows A and B is indicated by arrow C, the direction of arrow C is the upward direction of the magnetic tape cartridge 12, and the upward side of the magnetic tape cartridge 12 is the upper side of the magnetic tape cartridge 12. In the explanation of the structure below, "upper" refers to the upper side of the magnetic tape cartridge 12.

[0039] 2 to 4, for convenience of explanation, the direction opposite to the front direction of the magnetic tape cartridge 12 is referred to as the rear direction of the magnetic tape cartridge 12, and the rear side of the magnetic tape cartridge 12 is referred to as the rear side of the magnetic tape cartridge 12. In the following description of the structure, "rear" refers to the rear side of the magnetic tape cartridge 12.

[0040] 2 to 4, for convenience of explanation, the direction opposite to the upper direction of the magnetic tape cartridge 12 is referred to as the lower direction of the magnetic tape cartridge 12, and the lower side of the magnetic tape cartridge 12 is referred to as the lower side of the magnetic tape cartridge 12. In the following description of the structure, "lower" refers to the lower side of the magnetic tape cartridge 12.

[0041] As an example, as shown in FIG. 2, the magnetic tape cartridge 12 has a box-shaped case 16 that is generally rectangular in plan view. The case 16 houses a magnetic tape MT. The case 16 is made of resin such as polycarbonate and has an upper case 18 and a lower case 20. The upper case 18 and the lower case 20 are joined by welding (for example, ultrasonic welding) and screw fastening, with the lower peripheral surface of the upper case 18 and the upper peripheral surface of the lower case 20 in contact with each other. The joining method is not limited to welding and screw fastening, and other joining methods may also be used. The case 16 is an example of a "cartridge" according to the technology of the present disclosure.

[0042] The supply reel 22 is rotatably housed inside the case 16. The supply reel 22 includes a reel hub 22A, an upper flange 22B1, and a lower flange 22B2. The reel hub 22A is cylindrical. The reel hub 22A is the axial center of the supply reel 22, and its axial direction is aligned with the vertical direction of the case 16, and it is disposed in the center of the case 16. The upper flange 22B1 and the lower flange 22B2 are each formed in an annular shape. The center of the upper flange 22B1 in a plan view is fixed to the upper end of the reel hub 22A, and the center of the lower flange 22B2 in a plan view is fixed to the lower end of the reel hub 22A. The reel hub 22A and the lower flange 22B2 may be integrally molded.

[0043] A magnetic tape MT is wound around the outer peripheral surface of the reel hub 22A, and the widthwise ends of the magnetic tape MT are held by an upper flange 22B1 and a lower flange 22B2.

[0044] An opening 16B is formed in the front side of the right wall 16A of the case 16. The magnetic tape MT is pulled out through the opening 16B.

[0045] The lower case 20 is provided with a cartridge memory 24. Specifically, the cartridge memory 24 is housed in the right rear end portion of the lower case 20. The cartridge memory 24 is equipped with an IC chip having an NVM. In this embodiment, a so-called passive RFID tag is used as the cartridge memory 24, and various information is read and written to the cartridge memory 24 in a contactless manner. The cartridge memory 24 is an example of a "contactless storage medium" and a "storage medium" according to the technology of the present disclosure.

[0046] The cartridge memory 24 stores management information for managing the magnetic tape cartridge 12. The management information includes, for example, information about the cartridge memory 24 (e.g., information that can identify the magnetic tape cartridge 12), information about the magnetic tape MT (e.g., information indicating the recording capacity of the magnetic tape MT, information indicating an outline of the data recorded on the magnetic tape MT, information indicating the items of data recorded on the magnetic tape MT, information indicating the recording format of the data recorded on the magnetic tape MT, etc.), and information about the magnetic tape drive 14 (e.g., information indicating the specifications of the magnetic tape drive 14 and signals used in the magnetic tape drive 14). In addition, servo format information (see FIG. 14) is stored in the cartridge memory 24, as will be described in detail later.

[0047] 3, the magnetic tape drive 14 includes a transport device 26, a magnetic head 28, a control device 30, a storage 32, a UI device 34, and a communication interface 35. The magnetic tape cartridge 12 is loaded into the magnetic tape drive 14 in the direction of arrow A. In the magnetic tape drive 14, the magnetic tape MT is pulled out from the magnetic tape cartridge 12 and used. The magnetic head 28 is an example of a "magnetic head" according to the technology of the present disclosure.

[0048] The magnetic tape MT includes a magnetic layer 29A, a base film 29B, and a backcoat layer 29C. The magnetic layer 29A is formed on one side of the base film 29B, and the backcoat layer 29C is formed on the other side of the base film 29B. Data is recorded in the magnetic layer 29A. The magnetic layer 29A contains ferromagnetic powder. Examples of the ferromagnetic powder include ferromagnetic powders commonly used in the magnetic layers of various magnetic recording media. A preferred example of the ferromagnetic powder is hexagonal ferrite powder. Examples of the hexagonal ferrite powder include hexagonal strontium ferrite powder and hexagonal barium ferrite powder. The backcoat layer 29C is a layer containing a nonmagnetic powder such as carbon black. The base film 29B, also referred to as a support, is made of, for example, polyethylene terephthalate, polyethylene naphthalate, or polyamide. A nonmagnetic layer may be formed between the base film 29B and the magnetic layer 29A. In the magnetic tape MT, the surface on which the magnetic layer 29A is formed is the front surface 31 of the magnetic tape MT, and the surface on which the backcoat layer 29C is formed is the back surface 33 of the magnetic tape MT.

[0049] The magnetic tape drive 14 performs magnetic processing on the surface 31 of the magnetic tape MT using the magnetic head 28. Here, magnetic processing refers to recording data on the surface 31 of the magnetic tape MT and reading data from the surface 31 of the magnetic tape MT (i.e., reproducing data). In this embodiment, the magnetic tape drive 14 selectively records data on the surface 31 of the magnetic tape MT and reads data from the surface 31 of the magnetic tape MT using the magnetic head 28. That is, the magnetic tape drive 14 pulls out the magnetic tape MT from the magnetic tape cartridge 12 and uses the magnetic head 28 to record data on the surface 31 of the pulled-out magnetic tape MT, or uses the magnetic head 28 to read data from the surface 31 of the pulled-out magnetic tape MT.

[0050] The control device 30 controls the entire magnetic tape drive 14. In this embodiment, the control device 30 is realized by an ASIC, but the technology of the present disclosure is not limited to this. For example, the control device 30 may be realized by an FPGA and / or a PLC. The control device 30 may also be realized by a computer including a CPU, flash memory (e.g., EEPROM and / or SSD, etc.), and RAM. The control device 30 may also be realized by a combination of two or more of the ASIC, FPGA, PLC, and computer. In other words, the control device 30 may be realized by a combination of hardware and software. The control device 30 is an example of a "processor" according to the technology of the present disclosure.

[0051] The storage 32 is connected to the control device 30, and the control device 30 writes various types of information to the storage 32 and reads various types of information from the storage 32. Examples of the storage 32 include flash memory and / or HDD. The flash memory and HDD are merely examples, and any non-volatile memory that can be installed in the magnetic tape drive 14 may be used.

[0052] The UI-based device 34 is a device having a reception function for receiving an instruction signal indicating an instruction from a user and a presentation function for presenting information to the user. The reception function is realized by, for example, a touch panel, hard keys (e.g., a keyboard), and / or a mouse. The presentation function is realized by, for example, a display, a printer, and / or a speaker. The UI-based device 34 is connected to the control device 30. The control device 30 acquires the instruction signal received by the UI-based device 34. The UI-based device 34 presents various information to the user under the control of the control device 30.

[0053] The communication interface 35 is connected to the control device 30. The communication interface 35 is also connected to an external device 37 via a communication network (not shown) such as a WAN and / or LAN. The communication interface 35 controls the exchange of various information (e.g., data to be recorded on the magnetic tape MT, data read from the magnetic tape MT, and / or instruction signals given to the control device 30) between the control device 30 and the external device 37. The external device 37 may be, for example, a personal computer or a mainframe.

[0054] The transport device 26 is a device that selectively transports the magnetic tape MT in the forward or reverse direction along a predetermined path, and is equipped with a feed motor 36, a take-up reel 38, a take-up motor 40, and multiple guide rollers GR. Note that here, the forward direction refers to the feed direction of the magnetic tape MT, and the reverse direction refers to the rewind direction of the magnetic tape MT.

[0055] The supply motor 36 rotates the supply reel 22 in the magnetic tape cartridge 12 under the control of the control device 30. The control device 30 controls the supply motor 36 to control the rotation direction, rotation speed, rotation torque, etc. of the supply reel 22.

[0056] The take-up motor 40 rotates the take-up reel 38 under the control of the control device 30. The control device 30 controls the take-up motor 40 to control the rotation direction, rotation speed, rotation torque, etc. of the take-up reel 38.

[0057] When the magnetic tape MT is wound by the take-up reel 38, the control device 30 rotates the supply motor 36 and the take-up motor 40 so that the magnetic tape MT runs in the forward direction along a predetermined path. The rotational speed, rotational torque, etc. of the supply motor 36 and the take-up motor 40 are adjusted according to the speed at which the magnetic tape MT is wound onto the take-up reel 38. Furthermore, tension is applied to the magnetic tape MT by adjusting the rotational speed, rotational torque, etc. of each of the supply motor 36 and the take-up motor 40 by the control device 30. Furthermore, the tension applied to the magnetic tape MT is controlled by adjusting the rotational speed, rotational torque, etc. of each of the supply motor 36 and the take-up motor 40 by the control device 30.

[0058] When the magnetic tape MT is rewound onto the supply reel 22, the control device 30 rotates the supply motor 36 and the take-up motor 40 so that the magnetic tape MT runs in the reverse direction along the predetermined path.

[0059] In this embodiment, the tension applied to the magnetic tape MT is controlled by controlling the rotational speed and rotational torque of the supply motor 36 and the take-up motor 40, but the technology of the present disclosure is not limited to this. For example, the tension applied to the magnetic tape MT may be controlled using a dancer roller, or may be controlled by drawing the magnetic tape MT into a vacuum chamber.

[0060] Each of the guide rollers GR guides the magnetic tape MT. The predetermined path, i.e., the travel path of the magnetic tape MT, is determined by disposing the guide rollers GR at separate positions across the magnetic head 28 between the magnetic tape cartridge 12 and the take-up reel 38.

[0061] The magnetic head 28 includes a magnetic element unit 42 and a holder 44. The magnetic element unit 42 is held by the holder 44 so as to come into contact with the running magnetic tape MT. The magnetic element unit 42 has a plurality of magnetic elements.

[0062] The magnetic element unit 42 records data on the magnetic tape MT transported by the transport device 26, and reads data from the magnetic tape MT transported by the transport device 26. Here, data refers to, for example, the servo patterns 58 (see FIG. 9) and data other than the servo patterns 58, i.e., data recorded in the data band DB (see FIG. 9).

[0063] The magnetic tape drive 14 is equipped with a non-contact read / write device 46. The non-contact read / write device 46 is disposed below the magnetic tape cartridge 12 when the magnetic tape cartridge 12 is loaded so as to directly face the back surface 24A of the cartridge memory 24, and reads and writes information from and to the cartridge memory 24 in a non-contact manner.

[0064] 4, the non-contact read / write device 46 emits a magnetic field MF from the bottom side of the magnetic tape cartridge 12 toward the cartridge memory 24. The magnetic field MF penetrates the cartridge memory 24.

[0065] The non-contact read / write device 46 is connected to the control device 30. The control device 30 outputs a control signal to the non-contact read / write device 46. The control signal is a signal that controls the cartridge memory 24. The non-contact read / write device 46 generates a magnetic field MF in accordance with the control signal input from the control device 30, and emits the generated magnetic field MF toward the cartridge memory 24.

[0066] The non-contact type read / write device 46 performs contactless communication with the cartridge memory 24 via the magnetic field MF, and thereby performs processing on the cartridge memory 24 in accordance with the control signal. For example, under the control of the control device 30, the non-contact type read / write device 46 selectively performs processing to read information from the cartridge memory 24 and processing to store information in the cartridge memory 24 (i.e., processing to write information to the cartridge memory 24).

[0067] As an example, as shown in FIG. 5, the magnetic tape drive 14 includes a movement mechanism 48. The movement mechanism 48 has a movement actuator 48A. Examples of the movement actuator 48A include a voice coil motor and / or a piezoelectric actuator. The movement actuator 48A is connected to the control device 30, which controls the movement actuator 48A. The movement actuator 48A generates power under the control of the control device 30. The movement mechanism 48 receives the power generated by the movement actuator 48A to move the magnetic head 28 in the width direction of the magnetic tape MT.

[0068] The magnetic tape drive 14 is equipped with a tilt mechanism 49. The tilt mechanism 49 has a tilt actuator 49A. Examples of the tilt actuator 49A include a voice coil motor and / or a piezoelectric actuator. The tilt actuator 49A is connected to the control device 30, which controls the tilt actuator 49A. The tilt actuator 49A generates power under the control of the control device 30. By receiving the power generated by the tilt actuator 49A, the tilt mechanism 49 tilts the magnetic head 28 toward the longitudinal direction LD of the magnetic tape MT with respect to the width direction WD of the magnetic tape MT (see FIG. 8). In other words, the magnetic head 28 is skewed on the magnetic tape MT under the control of the control device 30.

[0069] As a comparative example for magnetic tape MT, a case where a conventionally known magnetic tape MT0 is used instead of magnetic tape MT will be described with reference to Figures 6 to 8. Note that when comparing magnetic tape MT0 and magnetic tape MT, the difference is that servo pattern 52 (see Figure 6) is applied to magnetic tape MT0, whereas servo pattern 58 (see Figure 9) is applied to magnetic tape MT.

[0070] 6, for example, servo bands SB1, SB2, and SB3 and data bands DB1 and DB2 are formed on the surface 31 of the magnetic tape MT0. For ease of explanation, 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, unless a distinction is particularly required.

[0071] The servo bands SB1 to SB3 and the data bands DB1 and DB2 are formed along the longitudinal direction LD (i.e., the overall length direction) of the magnetic tape MT0. Here, the overall length direction of the magnetic tape MT0 refers to the running direction of the magnetic tape MT0. The running direction of the magnetic tape MT0 is defined as two directions: a forward direction (hereinafter also simply referred to as the "forward direction") in which the magnetic tape MT0 runs from the supply reel 22 side to the take-up reel 38 side, and a reverse direction (hereinafter also simply referred to as the "reverse direction") in which the magnetic tape MT0 runs from the take-up reel 38 side to the supply reel 22 side.

[0072] The servo bands SB1 to SB3 are arranged at positions spaced apart in the width direction WD of the magnetic tape MT0 (hereinafter also simply referred to as the "width direction WD"). For example, the servo bands SB1 to SB3 are arranged at equal intervals along the width direction WD. In this embodiment, "equal intervals" refers to not only perfectly equal intervals, but also equal intervals that include an error that is generally acceptable in the technical field to which the technology of the present disclosure belongs and that does not contradict the spirit of the technology of the present disclosure.

[0073] The data band DB1 is arranged between the servo bands SB1 and SB2, and the data band DB2 is arranged between the servo bands SB2 and SB3. In other words, the servo bands SB and the data bands DB are arranged alternately along the width direction WD.

[0074] In the example shown in Figure 6, for the sake of convenience, three servo bands SB and two data bands DB are shown, but this is merely an example, and the technology disclosed herein can be applied to two servo bands SB and one data band DB, or even to four or more servo bands SB and three or more data bands DB.

[0075] A plurality of servo patterns 52 are recorded on the servo band SB along the longitudinal direction LD of the magnetic tape MT0. The servo patterns 52 are classified into servo patterns 52A and servo patterns 52B. The plurality of servo patterns 52 are arranged at regular intervals along the longitudinal direction LD of the magnetic tape MT0. In this embodiment, "constant" refers not only to perfect uniformity, but also to uniformity that includes an error that is generally acceptable in the technical field to which the technology of the present disclosure pertains and that does not contradict the spirit of the technology of the present disclosure.

[0076] In the servo band SB, adjacent servo patterns 52 are grouped together. In the example shown in Fig. 6, servo patterns 52A and 52B are shown as an example of a group of servo patterns 52. In the group of servo patterns 52, 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.

[0077] The servo pattern 52 is made up of linear magnetization region pairs 54. The linear magnetization region pairs 54 are classified into linear magnetization region pairs 54A and linear magnetization region pairs 54B.

[0078] The servo pattern 52A is made up of a pair of linear magnetization regions 54A. In the example shown in Fig. 6, linear magnetization regions 54A1 and 54A2 are shown as an example of the pair of linear magnetization regions 54A. Each of the linear magnetization regions 54A1 and 54A2 is a linearly magnetized region.

[0079] The linear magnetization regions 54A1 and 54A2 are inclined in opposite directions with respect to a virtual line C1, which is a virtual line along the width direction WD. In the example shown in Fig. 6, the linear magnetization regions 54A1 and 54A2 are inclined in line symmetry with respect to the virtual line C1. More specifically, the linear magnetization regions 54A1 and 54A2 are formed non-parallel to each other and inclined at a predetermined angle (e.g., 5 degrees) in opposite directions on the longitudinal direction LD side of the magnetic tape MT0 with the virtual line C1 as the axis of symmetry. In this embodiment, the virtual line C1 is an example of a "first virtual line" according to the technology of the present disclosure.

[0080] The linear magnetization region 54A1 is a set of five magnetized straight lines, ie, magnetization lines 54A1a, and the linear magnetization region 54A2 is a set of five magnetized straight lines, ie, magnetization lines 54A2a.

[0081] The servo pattern 52B is made up of a pair of linear magnetization regions 54B. In the example shown in Fig. 6, linear magnetization regions 54B1 and 54B2 are shown as an example of the pair of linear magnetization regions 54B. Each of the linear magnetization regions 54B1 and 54B2 is a linearly magnetized region.

[0082] The linear magnetization regions 54B1 and 54B2 are inclined in opposite directions with respect to a virtual line C2, which is a virtual line along the width direction WD. In the example shown in Fig. 6, the linear magnetization regions 54B1 and 54B2 are inclined in line symmetry with respect to the virtual line C2. More specifically, the linear magnetization regions 54B1 and 54B2 are formed non-parallel to each other and inclined at a predetermined angle (e.g., 5 degrees) in opposite directions on the longitudinal direction LD side of the magnetic tape MT0 with the virtual line C2 as the axis of symmetry. In this embodiment, the virtual line C2 is an example of a "first virtual line" according to the technology of the present disclosure.

[0083] The linear magnetization region 54B1 is a set of four magnetized straight lines, ie, magnetization lines 54B1a, and the linear magnetization region 54B2 is a set of four magnetized straight lines, ie, magnetization lines 54B2a.

[0084] The magnetic head 28 is disposed on the surface 31 side of the magnetic tape MT0 configured in this manner. The holder 44 is formed in a rectangular parallelepiped shape and is disposed so as to cross the surface 31 of the magnetic tape MT0 in the width direction WD. The multiple magnetic elements of the magnetic element unit 42 are linearly arranged along the longitudinal direction of the holder 44. The magnetic element unit 42 has, as its multiple magnetic elements, a pair of servo read elements SR and multiple data read / write elements DRW. The longitudinal length of the holder 44 is sufficiently long relative to the width of the magnetic tape MT0. For example, the longitudinal length of the holder 44 is set to be longer than the width of the magnetic tape MT0 regardless of the position of the magnetic element unit 42 on the magnetic tape MT. The servo read element SR is an example of a "servo read element" according to the technology disclosed herein.

[0085] The pair of servo read elements SR consists of servo read elements SR1 and SR2. The servo read element SR1 is disposed at one end of the magnetic element unit 42, and the servo read element SR2 is disposed at the other end of the magnetic element unit 42. In the example shown in Fig. 6, the servo read element SR1 is provided at a position corresponding to the servo band SB2, and the servo read element SR2 is provided at a position corresponding to the servo band SB3.

[0086] The plurality of data read / write elements DRW are arranged linearly between the servo read element SR1 and the servo read element SR2. The plurality of data read / write elements DRW are arranged at intervals along the longitudinal direction of the magnetic head 28 (for example, arranged at equal intervals along the longitudinal direction of the magnetic head 28). In the example shown in Fig. 6, the plurality of data read / write elements DRW are provided at positions corresponding to the data band DB2.

[0087] The control device 30 acquires a servo pattern signal resulting from the servo read element SR reading the servo pattern 52, and performs servo control in accordance with the acquired servo pattern signal. Here, servo control refers to control that moves the magnetic head 28 in the width direction WD of the magnetic tape MT0 by operating the movement mechanism 48 in accordance with the servo pattern 52 read by the servo read element SR.

[0088] By performing servo control, the plurality of data read / write elements DRW are positioned on designated areas in the data band DB and perform magnetic processing on the designated areas in the data band DB. In the example shown in Fig. 6, the plurality of data read / write elements DRW perform magnetic processing on designated areas in the data band DB2.

[0089] Furthermore, when the data band DB from which the magnetic element unit 42 reads data is changed (in the example shown in FIG. 6, when the data band DB from which the magnetic element unit 42 reads data is changed from data band DB2 to data band DB1), the movement mechanism 48, under the control of the control device 30, moves the magnetic head 28 in the width direction WD to change the positions of the pair of servo read elements SR. That is, by moving the magnetic head 28 in the width direction WD, the movement mechanism 48 moves the servo read element SR1 to a position corresponding to servo band SB1 and moves the servo read element SR2 to a position corresponding to servo band SB2. As a result, the positions of the multiple data read / write elements DRW are changed from on data band DB2 to on data band DB1, and the multiple data read / write elements DRW perform magnetic processing on data band DB1.

[0090] Recently, research has been conducted into technologies to reduce the effects of TDS (Transverse Dimensional Stability). TDS is affected by factors such as temperature, humidity, the pressure applied to the magnetic tape around the reel, and deterioration over time. If no countermeasures are taken, TDS will increase, causing off-track (i.e., misalignment of the data read / write element DRW with respect to the track in the data band DB) when magnetic processing is performed on the data band DB.

[0091] In the example shown in FIG. 7, the width of the magnetic tape MT0 shrinks over time. In this case, off-track occurs. The width of the magnetic tape MT0 may also expand, causing off-track. That is, when the width of the magnetic tape MT0 shrinks or expands over time, the position of the servo read element SR relative to the servo pattern 52 deviates in the width direction WD from the predetermined position determined by design (e.g., the center position of each of the linear magnetized regions 54A1, 54A2, 54B1, and 54B2). When the position of the servo read element SR relative to the servo pattern 52 deviates in the width direction WD from the predetermined position determined by design, the accuracy of servo control decreases, and the track in the data band DB and the position of the data read / write element DRW become misaligned. As a result, magnetic processing is no longer performed on the originally intended track.

[0092] One known method for reducing the effects of TDS is to skew the magnetic head 28 on the magnetic tape MT0, as shown in Figure 8, to maintain the position of the servo read element SR relative to the servo pattern 52 at a predetermined position determined by design.

[0093] The magnetic head 28 has a rotation axis RA. The rotation axis RA is provided at a position corresponding to the center of the magnetic element unit 42 included in the magnetic head 28 in a planar view. The magnetic head 28 is rotatably held by a tilting mechanism 49 via the rotation axis RA. A virtual line C3, which is a virtual center line, is provided in the magnetic head 28. The virtual line C3 passes through the rotation axis RA and extends in the longitudinal direction of the magnetic head 28 in a planar view (i.e., the direction in which multiple data read / write elements DRW are arranged). The magnetic head 28 is held by the tilting mechanism 49 so that the virtual line C3 is tilted toward the longitudinal direction LD of the magnetic tape MTO with respect to a virtual line C4, which is a virtual line along the width direction WD. In the example shown in FIG. 8, the magnetic head 28 is held by the tilting mechanism 49 in a position in which the virtual line C3 is tilted toward the supply reel 22 with respect to the virtual line C4 (i.e., a position inclined counterclockwise when viewed from the front side of the paper in FIG. 8).

[0094] The tilt mechanism 49 receives power from a tilt actuator 49A (see FIG. 5) and rotates the magnetic head 28 about the rotation axis RA on the surface 31 of the magnetic tape MT0. Under the control of the control device 30, the tilt mechanism 49 rotates the magnetic head 28 about the rotation axis RA on the surface 31 of the magnetic tape MT0, thereby changing the direction and angle of tilt (i.e., azimuth) of the imaginary line C3 with respect to the imaginary line C4.

[0095] The direction and angle of inclination of the imaginary line C3 relative to the imaginary line C4 are changed according to temperature, humidity, the pressure at which the magnetic tape MT0 is wound around the reel, deterioration over time, etc., or the expansion and contraction in the width direction WD of the magnetic tape MT due to these factors, thereby maintaining the position of the servo read element SR relative to the servo pattern 52 at a predetermined position determined by design.

[0096] The servo read element SR is formed linearly along the virtual straight line C3. Therefore, when the servo read element SR reads the servo pattern 52A, the angle formed by the linear magnetized region 54A1 and the servo read element SR is different from the angle formed by the linear magnetized region 54A2 and the servo read element SR in the linear magnetized region pair 54A. This difference in angle causes variations (e.g., variations in signal level and waveform distortion) due to azimuth loss between the servo pattern signal derived from the linear magnetized region 54A1 (i.e., the servo pattern signal obtained by reading the linear magnetized region 54A1 with the servo read element SR) and the servo pattern signal derived from the linear magnetized region 54A2 (i.e., the servo pattern signal obtained by reading the linear magnetized region 54A2 with the servo read element SR). 8, the angle formed by the servo read element SR and the linear magnetized region 54A1 is larger than the angle formed by the servo read element SR and the linear magnetized region 54A2, resulting in a smaller output of the servo pattern signal and a wider waveform. This results in variations in the servo pattern signal read by the servo read element SR across the servo band SB while the magnetic tape MT is running. Furthermore, when the servo read element SR reads the servo pattern 52B, variations due to azimuth loss occur between the servo pattern signal derived from the linear magnetized region 54B1 and the servo pattern signal derived from the linear magnetized region 54B2. Such variations in the servo pattern signal can be a factor in reducing the accuracy of servo control.

[0097] In view of these circumstances, this embodiment employs a magnetic tape MT as an example, as shown in Figure 9. The magnetic tape MT differs from the magnetic tape MT0 in that it has servo patterns 58 instead of the servo patterns 52. A plurality of servo patterns 58 are recorded on the servo band SB along the longitudinal direction LD of the magnetic tape MT. The plurality of servo patterns 58 are arranged at regular intervals along the longitudinal direction LD of the magnetic tape MT, similar to the plurality of servo patterns 52 recorded on the magnetic tape MT0.

[0098] 9, servo patterns 58A and 58B are shown as an example of a set of servo patterns 58. The servo patterns 58A and 58B are adjacent to each other along the longitudinal direction LD of the magnetic tape MT. The servo pattern 58A is located on the upstream side in the forward direction, and the servo pattern 58B is located on the downstream side in the forward direction.

[0099] The servo pattern 58 is made up of linear magnetization region pairs 60. The linear magnetization region pairs 60 are classified into linear magnetization region pairs 60A and linear magnetization region pairs 60B. In this embodiment, the linear magnetization region pairs 60 are an example of the "linear magnetization region pairs" according to the technology of the present disclosure.

[0100] The servo pattern 58A is made up of a pair of linear magnetization regions 60A. In the example shown in Fig. 9, linear magnetization regions 60A1 and 60A2 are shown as an example of the pair of linear magnetization regions 60A. Each of the linear magnetization regions 60A1 and 60A2 is a linearly magnetized region.

[0101] In this embodiment, the linear magnetization region 60A1 is an example of a "first linear magnetization region" according to the technology of the present disclosure, and the linear magnetization region 60A2 is an example of a "second linear magnetization region" according to the technology of the present disclosure.

[0102] The linear magnetization regions 60A1 and 60A2 are tilted in opposite directions with respect to the virtual line C1. The linear magnetization regions 60A1 and 60A2 are non-parallel to each other and tilt at different angles with respect to the virtual line C1. The linear magnetization region 60A1 has a steeper tilt angle with respect to the virtual line C1 than the linear magnetization region 60A2. Here, "steep" means, for example, that the angle of the linear magnetization region 60A1 with respect to the virtual line C1 is smaller than the angle of the linear magnetization region 60A2 with respect to the virtual line C1.

[0103] The total length of the linear magnetization region 60A1 is shorter than the total length of the linear magnetization region 60A2.

[0104] In the servo pattern 58A, the linear magnetization region 60A1 includes a plurality of magnetization lines 60A1a, and the linear magnetization region 60A2 includes a plurality of magnetization lines 60A2a. The number of magnetization lines 60A1a included in the linear magnetization region 60A1 is the same as the number of magnetization lines 60A2a included in the linear magnetization region 60A2.

[0105] The linear magnetization region 60A1 is a set of five magnetized straight lines 60A1a, and the linear magnetization region 60A2 is a set of five magnetized straight lines 60A2a. Within the servo band SB, the positions of both ends of the linear magnetization region 60A1 (i.e., the positions of both ends of each of the five magnetization straight lines 60A1a) and the positions of both ends of the linear magnetization region 60A2 (i.e., the positions of both ends of each of the five magnetization straight lines 60A2a) are aligned in the width direction WD. Note that, although an example is given here in which the positions of both ends of each of the five magnetization lines 60A1a and the positions of both ends of each of the five magnetization lines 60A2a are aligned, this is merely an example, and it is sufficient that the positions of both ends of one or more of the five magnetization lines 60A1a and the positions of both ends of one or more of the five magnetization lines 60A2a are aligned. Furthermore, in this embodiment, the concept of "aligned" not only means completely aligned, but also includes the meaning of "aligned" that includes an error that is generally acceptable in the technical field to which the technology of the present disclosure belongs and that does not contradict the spirit of the technology of the present disclosure.

[0106] The servo pattern 58B is made up of a pair of linear magnetization regions 60B. In the example shown in Fig. 9, linear magnetization regions 60B1 and 60B2 are shown as an example of the pair of linear magnetization regions 60B. Each of the linear magnetization regions 60B1 and 60B2 is a linearly magnetized region.

[0107] In this embodiment, the linear magnetization region 60B1 is an example of a "first linear magnetization region" according to the technology of the present disclosure, and the linear magnetization region 60B2 is an example of a "second linear magnetization region" according to the technology of the present disclosure.

[0108] The linear magnetization regions 60B1 and 60B2 are tilted in opposite directions with respect to the virtual line C2. The linear magnetization regions 60B1 and 60B2 are non-parallel to each other and tilt at different angles with respect to the virtual line C2. The linear magnetization region 60B1 has a steeper tilt angle with respect to the virtual line C2 than the linear magnetization region 60B2. Here, "steep" means, for example, that the angle of the linear magnetization region 60B1 with respect to the virtual line C2 is smaller than the angle of the linear magnetization region 60B2 with respect to the virtual line C2.

[0109] The total length of the linear magnetization region 60B1 is shorter than the total length of the linear magnetization region 60B2.

[0110] In the servo pattern 58B, the linear magnetization region 60B1 includes a plurality of magnetization lines 60B1a, and the linear magnetization region 60B2 includes a plurality of magnetization lines 60B2a. The number of magnetization lines 60B1a included in the linear magnetization region 60B1 is the same as the number of magnetization lines 60B2a included in the linear magnetization region 60B2.

[0111] The total number of magnetization lines 60B1a and 60B2a included in the servo pattern 58B is different from the total number of magnetization lines 60A1a and 60A2a included in the servo pattern 58A. In the example shown in Fig. 9, the total number of magnetization lines 60A1a and 60A2a included in the servo pattern 58A is 10, while the total number of magnetization lines 60B1a and 60B2a included in the servo pattern 58B is 8.

[0112] The linear magnetization region 60B1 is a set of four magnetized straight lines, ie, magnetization lines 60B1a, and the linear magnetization region 60B2 is a set of four magnetized straight lines, ie, magnetization lines 60B2a. Within the servo band SB, the positions of both ends of the linear magnetization region 60B1 (i.e., the positions of both ends of each of the four magnetization lines 60B1a) and the positions of both ends of the linear magnetization region 60B2 (i.e., the positions of both ends of each of the four magnetization lines 60B2a) are aligned in the width direction WD.

[0113] Here, an example is given in which the positions of both ends of each of the four magnetization lines 60B1a and the positions of both ends of each of the four magnetization lines 60B2a are aligned, but this is merely one example, and it is sufficient that the positions of both ends of one or more of the four magnetization lines 60B1a and the positions of both ends of one or more of the four magnetization lines 60B2a are aligned.

[0114] Furthermore, here, an example of a linear magnetization region 60A1 is a set of magnetization lines 60A1a, which are five magnetized lines; an example of a linear magnetization region 60A2 is a set of magnetization lines 60A2a, which are five magnetized lines; an example of a linear magnetization region 60B1 is a set of magnetization lines 60B1a, which are four magnetized lines; and an example of a linear magnetization region 60B2 is a set of magnetization lines 60B2a, which are four magnetized lines, but the technology of the present disclosure is not limited to this. For example, the linear magnetization region 60A1 may be a number of magnetization lines 60A1a that contribute to determining the position of the magnetic head 28 on the magnetic tape MT, the linear magnetization region 60A2 may be a number of magnetization lines 60A2a that contribute to determining the position of the magnetic head 28 on the magnetic tape MT, the linear magnetization region 60B1 may be a number of magnetization lines 60B1a that contribute to determining the position of the magnetic head 28 on the magnetic tape MT, and the linear magnetization region 60B2 may be a number of magnetization lines 60B2a that contribute to determining the position of the magnetic head 28 on the magnetic tape MT.

[0115] Here, the geometric characteristics of the linear magnetized region pair 60A on the magnetic tape MT will be described with reference to Fig. 10. In this embodiment, the geometric characteristics refer to generally recognized geometric characteristics such as length, shape, orientation, and / or position.

[0116] 10, the geometric characteristics of the linear magnetization region pair 60A on the magnetic tape MT can be expressed using a virtual linear region pair 62. The virtual linear region pair 62 is made up of a virtual linear region 62A and a virtual linear region 62B. The geometric characteristics of the linear magnetization region pair 60A on the magnetic tape MT correspond to the geometric characteristics based on the virtual linear region pair 62 when the entire virtual linear region pair 62 is tilted with respect to the virtual line C1 by tilting the symmetry axes SA1 of the virtual linear regions 62A and 62B, which are tilted line-symmetrically with respect to the virtual line C1, with respect to the virtual line C1.

[0117] In this embodiment, the virtual linear region pair 62 is an example of a "pair of virtual linear regions" according to the technology of the present disclosure, the virtual linear region 62A is an example of "one virtual linear region" according to the technology of the present disclosure, and the virtual linear region 62B is an example of "the other virtual linear region" according to the technology of the present disclosure.

[0118] The virtual linear region pair 62 is a virtual linear magnetization region pair having the same geometric characteristics as the linear magnetization region pair 54A shown in Fig. 6. The virtual linear region pair 62 is a virtual magnetization region used for convenience in explaining the geometric characteristics of the linear magnetization region pair 60A on the magnetic tape MT, and is not an actual magnetization region.

[0119] The virtual linear region 62A has the same geometric characteristics as the linear magnetization region 54A1 shown in Fig. 6 and is made up of five virtual straight lines 62A1 corresponding to the five magnetization straight lines 54A1a shown in Fig. 6. The virtual linear region 62B has the same geometric characteristics as the linear magnetization region 54B1 shown in Fig. 6 and is made up of five virtual straight lines 62B1 corresponding to the five magnetization straight lines 54A2a shown in Fig. 6.

[0120] A center O1 is provided in the virtual linear region pair 62. For example, the center O1 is the center of a line segment L0 connecting the center of the straight line 62A1 located most upstream in the forward direction among the five straight lines 62A1 and the center of the straight line 62B1 located most downstream in the forward direction among the five straight lines 62B1.

[0121] 6, the virtual linear region pair 62 has the same geometric characteristics as the linear magnetization region pair 54A shown in FIG. 6, so the virtual linear region 62A and the virtual linear region 62B are tilted symmetrically with respect to the virtual line C1. Consider a case where the servo read element SR reads the virtual linear region pair 62 in a state where the entire virtual linear region pair 62 is tilted with respect to the virtual line C1 by tilting the symmetry axis SA1 of the virtual linear regions 62A and 62B by an angle a (for example, 10 degrees) with respect to the virtual line C1, with the center O1 as the rotation axis. In this case, there are some portions of the virtual linear region pair 62 in the width direction WD where the virtual linear region 62A is read but the virtual linear region 62B is not, or where the virtual linear region 62A is not read but the virtual linear region 62B is read. That is, when reading is performed by the servo read element SR in each of the imaginary linear regions 62A and 62B, there are insufficient portions and unnecessary portions.

[0122] Therefore, by supplementing the missing parts and cutting out the unnecessary parts, the positions of both ends of the imaginary linear region 62A (i.e., the positions of both ends of each of the five straight lines 62A1) are aligned with the positions of both ends of the imaginary linear region 62B (i.e., the positions of both ends of each of the five straight lines 62B1) in the width direction WD.

[0123] The geometric characteristics of the virtual linear region pair 62 thus obtained (i.e., the geometric characteristics of the virtual servo pattern) correspond to the geometric characteristics of the actual servo pattern 58 A. That is, in the servo band SB, a linear magnetization region pair 60A having geometric characteristics equivalent to the geometric characteristics of the virtual linear region pair 62 obtained by aligning the positions of both ends of the virtual linear region 62A and the positions of both ends of the virtual linear region 62B in the width direction WD is recorded.

[0124] Here, the inclination of the linear magnetization region pair 60A with respect to the virtual line C1, one of the geometric characteristics of the linear magnetization region pair 60A, will be described with reference to FIG. 11. The geometric characteristics of the linear magnetization region pair 60A correspond to the geometric characteristics of the virtual linear region pair 62. Therefore, like the virtual linear region pair 62, the linear magnetization region pair 60A is obtained by inclining the symmetry axis SA2 of the linear magnetization regions 60A1 and 60B2 by an angle α (i.e., equivalent to the angle a) with respect to the virtual line C1, with the center O1 as the rotation axis. In other words, the entire linear magnetization region pair 60A is inclined by the angle α with respect to the virtual line C1. Therefore, the servo pattern 58 including the linear magnetization region pair 60A is also inclined by the angle α with respect to the virtual line C1 (hereinafter referred to as the inclination angle α of the servo pattern 58).

[0125] Furthermore, the linear magnetization region 60A1 of the pair of linear magnetization regions 60A is inclined at an angle θa (hereinafter referred to as the inclination angle θa of the linear magnetization region 60A1) with respect to the virtual line C1. Furthermore, the linear magnetization region 60A2 of the pair of linear magnetization regions 60A is inclined at an angle θb (hereinafter referred to as the inclination angle θb of the linear magnetization region 60A2) with respect to the virtual line C1. The inclination angle θa of the linear magnetization region 60A1 and the inclination angle θb of the linear magnetization region 60A2 both correspond to the inclination angle α of the servo pattern 58.

[0126] The linear magnetization region pair 60B differs from the linear magnetization region pair 60A only in that it has four magnetization lines 60B1a instead of the five magnetization lines 60A1a and four magnetization lines 60B2a instead of the five magnetization lines 60A2a. Therefore, in the servo band SB, a linear magnetization region pair 60B having geometric characteristics equivalent to the geometric characteristics of a virtual linear region pair (not shown) obtained by aligning the positions of both ends of each of the four lines 62A1 and the positions of both ends of each of the four lines 62B1 in the width direction WD is recorded.

[0127] 12, when the servo read element SR reads the servo pattern 58A (i.e., the pair of linear magnetized regions 60A) in a state where the directions of the virtual straight lines C1 and C3 are aligned (i.e., the longitudinal direction of the magnetic head 28 is aligned with the width direction WD), variations due to azimuth loss occur between the servo pattern signals derived from the linear magnetized regions 60A1 and the servo pattern signals derived from the linear magnetized regions 60A2. A similar phenomenon also occurs when the servo read element SR reads the servo pattern 58B (i.e., the pair of linear magnetized regions 60B) in a state where the directions of the virtual straight lines C1 and C3 are aligned (i.e., the longitudinal direction of the magnetic head 28 is aligned with the width direction WD).

[0128] 13, for example, the tilt mechanism 49 (see FIG. 8) skews the magnetic head 28 on the magnetic tape MT about the rotation axis RA so that the imaginary line C3 is tilted upstream in the forward direction by an angle β (i.e., the angle β counterclockwise when viewed from the front side of the paper in FIG. 13) with respect to the imaginary line C1 (hereinafter, for convenience of explanation, the angle of the imaginary line C3 with respect to the imaginary line C1 will be referred to as the "magnetic head skew angle"). Even in this case, if there is a large deviation between the tilt angle α of the servo patterns 58 and the magnetic head skew angle (for example, if the tilt angle α of the servo patterns 58 is 5 degrees and the magnetic head skew angle is 10 degrees), variations in the servo pattern signals due to azimuth loss may occur.

[0129] 13, the angle formed by the servo read element SR and the linear magnetized region 60A1 is larger than the angle formed by the servo read element SR and the linear magnetized region 60A2, so the output of the servo pattern signal is small and the waveform is broadened, resulting in variations in the servo pattern signal read by the servo read element SR across the servo band SB while the magnetic tape MT is running. Also, when the servo read element SR reads the servo pattern 58B, variations due to azimuth loss occur between the servo pattern signal derived from the linear magnetized region 60B1 and the servo pattern signal derived from the linear magnetized region 60B2.

[0130] 14, the control device 30 controls the skew angle of the magnetic head 28 based on the servo format information SF of the magnetic tape MT. The servo format information SF is stored in a cartridge memory 24 provided in the magnetic tape cartridge 12. The control device 30 acquires the servo format information SF from the cartridge memory 24 via a non-contact read / write device 46.

[0131] The servo format information SF includes servo pattern tilt information SF1. The servo pattern tilt information SF1 refers to information relating to the tilt of the servo pattern 58. The servo pattern tilt information SF1 may include, for example, information indicating the tilt angle α of the servo pattern 58, but this is merely an example. For example, the servo pattern tilt information SF1 includes information indicating the angle θa (see FIG. 11) of the linear magnetization region 60A1 relative to the virtual line C1 and the angle θb (see FIG. 11) of the linear magnetization region 60A2 relative to the virtual line C1. Similarly, the servo pattern tilt information SF1 includes information indicating the angle θa (see FIG. 11) of the linear magnetization region 60B1 relative to the virtual line C2 and the angle θb (see FIG. 11) of the linear magnetization region 60B2 relative to the virtual line C2.

[0132] The tilt angle α of the servo pattern 58 corresponds to the skew angle of the servo pattern recording head WH (see FIG. 18 ) when the servo pattern 58 is recorded during the manufacturing stage of the magnetic tape MT, for example, and is an angle obtained during the manufacturing stage of the magnetic tape MT, but this is merely one example. For example, the servo pattern tilt information SF1 may be a design value or an actual measurement value of the tilt angle α of the servo pattern 58 during the manufacturing stage of the magnetic tape MT (for example, the tilt angle α of the servo pattern 58 actually recorded on the magnetic tape MT), or may be a result obtained through simulation and / or experiment regarding the change in the tilt angle α of the servo pattern 58 due to a change in the width of the magnetic tape MT. Furthermore, the servo pattern tilt information SF1 may be the tilt angle α of the servo pattern 58 as an image of the magnetic tape MT obtained by developing the magnetic tape MT. Furthermore, the servo pattern tilt information SF1 may be a result of calculating the tilt angle α of the servo pattern 58 based on a measurement result of the amount of change in the width of the magnetic tape MT over the entire length of the magnetic tape MT (hereinafter also referred to as a “width change amount measurement result”). In this case, the servo pattern tilt information SF1 may be calculated from a function using a predetermined fixed value as the reference value of the tilt angle α and a variable based on the width change amount measurement result.

[0133] The control device 30 operates the tilt mechanism 49 based on the servo format information SF. This adjusts the magnetic head skew angle. For example, the magnetic head skew angle is adjusted to the same angle as the tilt angle α of the servo pattern 58. In this embodiment, the concept of "same" not only means "exactly the same," but also includes the meaning of "same" including an error that is generally acceptable in the technical field to which the technology of the present disclosure belongs and that does not contradict the spirit of the technology of the present disclosure.

[0134] The magnetic head skew angle may also be adjusted to an angle that keeps the azimuth loss within an allowable range (hereinafter simply referred to as "allowable range"). Here, the allowable range refers to a range in which the accuracy of detecting the servo pattern 58 is at least a certain level. To keep the magnetic head skew angle within the allowable range, for example, the control device 30 may refer to the servo format information SF and derive an angle within the allowable range as the magnetic head skew angle. Note that the angle within the allowable range may be derived, for example, from a table or an arithmetic expression that associates the servo format information SF with the magnetic head skew angle.

[0135] As an example, as shown in FIG. 15, the tilt mechanism 49 skews the magnetic head 28 about the rotation axis RA on the magnetic tape MT so that the imaginary line C3 is tilted by an angle γ toward the upstream side in the forward direction relative to the imaginary line C1 (i.e., the angle γ counterclockwise when viewed from the front side of the paper in FIG. 15). In this way, the magnetic head 28 is tilted by an angle γ toward the upstream side in the forward direction on the magnetic tape MT. Here, the angle γ is the same as the tilt angle α of the servo pattern 58. As a result, compared to the examples shown in FIGS. 12 and 13, the variation due to azimuth loss between the servo pattern signals derived from the linear magnetized region 60A1 and the servo pattern signals derived from the linear magnetized region 60A2 is reduced. Similarly, when the servo read element SR reads the servo pattern 58B (i.e., the linear magnetized region pair 60B), the variation due to azimuth loss between the servo pattern signals derived from the linear magnetized region 60B1 and the servo pattern signals derived from the linear magnetized region 60B2 is reduced.

[0136] As an example, as shown in FIG. 16, the control device 30 includes a control unit 30A and a position detection unit 30B. The position detection unit 30B includes a first position detection unit 30B1 and a second position detection unit 30B2. The position detection unit 30B acquires a servo band signal S resulting from the servo band SB being read by the servo read element SR, and detects the position of the magnetic head 28 on the magnetic tape MT based on the acquired servo band signal S. The servo band signal S includes not only a servo pattern signal resulting from the reading of the servo pattern 58, but also signals unnecessary for servo control (e.g., noise, etc.). Therefore, in order to achieve control based on the servo pattern signal (e.g., servo control, etc.) with high accuracy, the control device 30 needs to detect the servo pattern signal from the servo band signal S with high accuracy.

[0137] The servo band signal S is classified into a first servo band signal S1 and a second servo band signal S2. The first servo band signal S1 is a servo band signal S resulting from reading the servo band SB2 by the servo read element SR1, and the second servo band signal S2 is a servo band signal S resulting from reading the servo band SB3 by the servo read element SR2.

[0138] The first position detector 30B1 acquires a first servo band signal S1, and the second position detector 30B2 acquires a second servo band signal S2. In the example shown in Fig. 16, the first position detector 30B1 acquires the first servo band signal S1 obtained by the servo read element SR1 reading the servo band SB2, and the second position detector 30B2 acquires the second servo band signal S2 obtained by the servo read element SR2 reading the servo band SB3. The first position detector 30B1 detects the position of the servo read element SR1 relative to the servo band SB2 based on the first servo band signal S1, and the second position detector 30B2 detects the position of the servo read element SR2 relative to the servo band SB3 based on the second servo band signal S2.

[0139] The control unit 30A performs various controls based on the position detection result by the first position detection unit 30B1 (i.e., the result of position detection by the first position detection unit 30B1) and the position detection result by the second position detection unit 30B2 (i.e., the result of position detection by the second position detection unit 30B2). Here, the various controls refer to, for example, servo control, skew angle control, and / or tension control. Tension control refers to control of the tension applied to the magnetic tape MT (e.g., tension to reduce the effects of TDS).

[0140] As an example, as shown in FIG. 17, the position detection unit 30B detects a servo pattern signal, which is the result of the servo pattern 58 being read from the magnetic tape MT by the servo read element SR, using an autocorrelation coefficient.

[0141] An ideal waveform signal 66 is stored in the cartridge memory 24. That is, the servo format information SF stored in the cartridge memory 24 includes the ideal waveform signal 66. The ideal waveform signal 66 is a signal indicating a single ideal waveform included in the servo band signal S (for example, an ideal signal resulting from reading one of the ideal magnetization lines included in the servo pattern 58 by the servo read element SR). The ideal waveform signal 66 can also be considered a sample signal to be compared with the servo band signal S. Note that while an example in which the ideal waveform signal 66 is stored in the cartridge memory 24 has been given here, this is merely an example. For example, the ideal waveform signal 66 may be stored in the storage 32 along with the cartridge memory 24. The ideal waveform signal 66 may also be recorded in a BOT area MT1 (see FIG. 41) provided at the beginning of the magnetic tape MT and / or an EOT area MT2 (see FIG. 41) provided at the end of the magnetic tape MT.

[0142] The autocorrelation coefficient used by the position detection unit 30B is a coefficient that indicates the degree of correlation between the servo band signal S and the ideal waveform signal 66. The position detection unit 30B acquires the ideal waveform signal 66 from the storage 32 and compares the acquired ideal waveform signal 66 with the servo band signal S. The position detection unit 30B then calculates the autocorrelation coefficient based on the comparison result. The position detection unit 30B detects a position on the servo band SB where the correlation between the servo band signal S and the ideal waveform signal 66 is high (for example, a position where the servo band signal S and the ideal waveform signal 66 match) according to the autocorrelation coefficient.

[0143] The position of the servo read element SR relative to the servo band SB is detected based on, for example, the distance between the servo patterns 58A and 58B in the longitudinal direction LD. For example, the distance between the servo patterns 58A and 58B in the longitudinal direction LD is detected according to an autocorrelation coefficient. When the servo read element SR is located above the servo pattern 58 (i.e., above the front view of the paper in FIG. 16), the distance between the linear magnetization region 60A1 and the linear magnetization region 60A2 is narrow, and the distance between the linear magnetization region 60B1 and the linear magnetization region 60B2 is also narrow. On the other hand, when the servo read element SR is located below the servo pattern 58 (i.e., below the front view of the paper in FIG. 16), the distance between the linear magnetization region 60A1 and the linear magnetization region 60A2 is wide, and the distance between the linear magnetization region 60B1 and the linear magnetization region 60B2 is also wide. In this way, the position detection unit 30B detects the position of the servo read element SR relative to the servo band SB using the distance between the linear magnetization region 60A1 and the linear magnetization region 60A2, and the distance between the linear magnetization region 60B1 and the linear magnetization region 60B2, detected according to the autocorrelation coefficient.

[0144] The control unit 30A adjusts the position of the magnetic head 28 by operating the movement mechanism 48 based on the position detection result of the position detection unit 30B (i.e., the result of the position detection by the position detection unit 30B). The control unit 30A also causes the magnetic element unit 42 to perform magnetic processing on the data band DB of the magnetic tape MT. That is, the control unit 30A obtains a read signal from the magnetic element unit 42 (i.e., data read from the data band DB of the magnetic tape MT by the magnetic element unit 42) and supplies a recording signal to the magnetic element unit 42 to record data corresponding to the recording signal on the data band DB of the magnetic tape MT.

[0145] Furthermore, to reduce the effects of TDS, the control unit 30A calculates the servo band pitch from the position detection result of the position detection unit 30B, and performs tension control and skews the magnetic head 28 on the magnetic tape MT according to the calculated servo band pitch. Tension control is achieved by adjusting the rotation speed and rotation torque of the feed motor 36 and the take-up motor 40. Skew of the magnetic head 28 is achieved by operating a tilt mechanism 49.

[0146] Next, among the multiple steps included in the manufacturing process of the magnetic tape MT, an example of a servo pattern recording step of recording the servo patterns 58 on the servo bands SB of the magnetic tape MT and a winding step of winding the magnetic tape MT will be described.

[0147] As an example, a servo writer SW is used in the servo pattern recording process, as shown in Fig. 18. The servo writer SW includes a supply reel SW1, a take-up reel SW2, a drive device SW3, a pulse signal generator SW4, a servo writer controller SW5, multiple guides SW6, a transport path SW7, a servo pattern recording head WH, and a verify head VH.

[0148] The servo writer controller SW5 controls the entire servo writer SW. In this embodiment, the servo writer controller SW5 is implemented by an ASIC, but the technology of the present disclosure is not limited to this. For example, the servo writer controller SW5 may be implemented by an FPGA and / or a PLC. The servo writer controller SW5 may also be implemented by a computer including a CPU, flash memory (e.g., EEPROM and / or SSD), and RAM. The servo writer controller SW5 may also be implemented by a combination of two or more of the ASIC, FPGA, PLC, and computer. In other words, the servo writer controller SW5 may be implemented by a combination of hardware and software.

[0149] A pancake is set on the supply reel SW1. A pancake is a large diameter roll of magnetic tape MT, which is cut to the product width from a wide web before the servo pattern 58 is written, wound around a hub.

[0150] The drive unit SW3 has a motor (not shown) and gears (not shown) and is mechanically connected to the supply reel SW1 and the take-up reel SW2. When the magnetic tape MT is wound by the take-up reel SW2, the drive unit SW3 generates power in accordance with instructions from the servo writer controller SW5 and transmits the generated power to the supply reel SW1 and the take-up reel SW2 to rotate them. That is, the supply reel SW1 receives power from the drive unit SW3 and rotates to feed the magnetic tape MT to a predetermined transport path SW7. The take-up reel SW2 receives power from the drive unit SW3 and rotates to wind the magnetic tape MT fed from the supply reel SW1. The rotation speed and rotation 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 around the take-up reel SW2.

[0151] A plurality of guides SW6 and a servo pattern recording head WH are arranged on the transport path SW7. The servo pattern recording head WH is arranged between the plurality of guides SW6 on the side of the surface 31 of the magnetic tape MT. The magnetic tape MT sent out from the supply reel SW1 to the transport path SW7 is guided by the plurality of guides SW6, passes over the servo pattern recording head WH, and is taken up by the take-up reel SW2.

[0152] The manufacturing process for magnetic tape MT includes several steps in addition to the servo pattern recording step, including an inspection step and a winding step.

[0153] For example, the inspection process is a process of inspecting the servo bands SB formed on the surface 31 of the magnetic tape MT by the servo pattern recording head WH. Inspecting the servo bands SB refers to, for example, a process of determining whether the servo patterns 58 recorded on the servo bands SB are correct. Determining whether the servo patterns 58 are correct refers to, for example, determining whether the magnetization lines 60A1a, 60A2a, 60B1a, and 60B2a of the servo patterns 58A and 58B are recorded exactly and within the allowable error relative to predetermined locations on the surface 31 (i.e., verifying the servo patterns 58).

[0154] The inspection process is performed using a servo writer controller SW5 and a verify head VH. The verify head VH is located downstream of the servo pattern recording head WH in the transport direction of the magnetic tape MT. Similar to the magnetic head 28, the verify head VH is provided with multiple servo read elements (not shown), which read multiple servo bands SB. Similar to the magnetic head 28, the verify head VH is skewed above the surface 31 of the magnetic tape MT. The verify head VH is an example of a "magnetic head" according to the technology of the present disclosure.

[0155] The verify head VH is connected to the servo writer controller SW5. The verify head VH is disposed at a position directly facing the servo band SB when viewed from the surface 31 side of the magnetic tape MT (i.e., the back side of the verify head VH). The verify head VH reads the servo patterns 58 recorded on the servo band SB and outputs the read results (hereinafter referred to as "servo pattern read results") to the servo writer controller SW5. The servo writer controller SW5 inspects the servo band SB (e.g., determines whether the servo pattern 58 is correct) based on the servo pattern read results (e.g., servo band signal S) input from the verify head VH. For example, the servo writer controller SW5 operates as the position detector 30B shown in FIG. 17 to obtain position detection results from the servo pattern read results and inspects the servo band SB by using the position detection results to determine whether the servo pattern 58 is correct.

[0156] The servo writer controller SW5 outputs information indicating the results of inspecting the servo band SB (for example, the results of determining whether the servo pattern 58 is correct or not) to a predetermined output destination (for example, storage 32 (see Figure 3), UI device 34 (see Figure 3), and / or external device 37 (see Figure 3), etc.).

[0157] For example, after the inspection process is completed, the winding process is carried out next. The winding process is a process of winding the magnetic tape MT onto the supply reel 22 (see FIGS. 2 to 4) housed in the magnetic tape cartridge 12 (see FIGS. 1 to 4)) used for each of the multiple magnetic tape cartridges 12 (see FIGS. 1 to 4). In the winding process, a winding motor M is used. The winding motor M is mechanically connected to the supply reel 22 via a gear or the like. Under the control of a control device (not shown), the winding motor M applies a rotational force to the supply reel 22 to rotate the supply reel 22. The magnetic tape MT wound onto the take-up reel SW2 is wound onto the supply reel 22 by the rotation of the supply reel 22. In the winding process, a cutting device (not shown) is used. When the required amount of magnetic tape MT is wound onto each of the plurality of supply reels 22, the magnetic tape MT fed from the take-up reel SW2 to the supply reel 22 is cut by a cutting device.

[0158] The pulse signal generator SW4 generates a pulse signal under the control of the servo writer controller SW5 and supplies the generated pulse signal to the servo pattern recording head WH. While the magnetic tape MT is traveling at a constant speed on the transport path SW7, the servo pattern recording head WH records the servo pattern 58 on the servo band SB in accordance with the pulse signal supplied from the pulse signal generator SW4.

[0159] Next, the operation of the magnetic tape system 10 will be described.

[0160] In the magnetic tape system 10 according to this embodiment, the control device 30 (see FIG. 3, etc.) performs servo pattern detection processing, as shown in FIG. 19. The flow of the servo pattern detection processing shown in FIG. 19 is an example of a "servo pattern detection method" according to the technique of the present disclosure.

[0161] 19, first, in step ST10, the control device 30 acquires the servo format information SF. For example, the control device 30 acquires the servo format information SF from the cartridge memory 24 via the non-contact read / write device 46. After the processing of step ST10 is executed, the servo pattern detection processing proceeds to step ST12.

[0162] In step ST12, the control device 30 executes processing according to the servo format information SF acquired from the cartridge memory 24 in step ST10. For example, the control device 30 operates the tilt mechanism 49 based on the servo pattern tilt information SF1 included in the servo format information SF. After the processing of step ST12 is executed, the servo pattern detection processing ends.

[0163] As described above, the magnetic tape cartridge 12 is loaded into the magnetic tape drive 14. In the magnetic tape drive 14, when magnetic processing is performed on the magnetic tape MT by the magnetic element unit 42 (see FIGS. 3 and 17), the magnetic tape MT is pulled out from the magnetic tape cartridge 12, and the servo read element SR of the magnetic head 28 reads the servo pattern 58 in the servo band SB.

[0164] The magnetic tape cartridge 12 according to this embodiment is provided with a cartridge memory 24. The cartridge memory 24 stores servo format information SF, which includes servo pattern tilt information SF1, which is information relating to the tilt of the servo pattern. The control device 30 operates the tilt mechanism 49 based on the servo format information SF. This causes the magnetic head skew angle to approach the tilt angle α of the servo pattern 58. Therefore, with this configuration, the variation in the servo pattern signal is reduced compared to when the servo pattern 58 is read without taking into account the information relating to the tilt of the servo pattern 58, and a highly reliable servo pattern signal can be obtained.

[0165] 9 and 10, the linear magnetized regions 60A1 and 60A2 included in the servo pattern 58A recorded on the servo band SB of the magnetic tape MT are tilted in opposite directions with respect to the imaginary line C1. Meanwhile, as shown in FIGS. 14 and 15, the magnetic head 28 on the magnetic tape MT is also tilted upstream in the forward direction by an angle γ (i.e., an angle γ counterclockwise when viewed from the front side of the paper of FIGS. 14 and 15). When the servo pattern 58A is read by the servo read element SR in this state, the angle between the linear magnetized region 60A1 and the servo read element SR and the angle between the linear magnetized region 60A2 and the servo read element SR become close, so that the variation in the servo pattern signal due to azimuth loss is smaller than the variation occurring between the servo pattern signal derived from the linear magnetized region 54A1 included in the conventional servo pattern 52A and the servo pattern signal derived from the linear magnetized region 54A2 included in the conventional servo pattern 52A.

[0166] As a result, the variation between the servo pattern signals derived from the linear magnetization regions 60A1 and 60A2 is smaller than the variation between the servo pattern signals derived from the linear magnetization regions 54A1 and 54A2 included in the conventionally known servo pattern 52A, and a more reliable servo pattern signal can be obtained than the servo pattern signal obtained from the conventionally known servo pattern 52A (hereinafter, this effect will also be referred to as a "first effect"). Note that, as shown in Figures 14 and 15, even when the servo pattern 58B is read by the servo read element SR in a state where the magnetic head 28 is tilted upstream in the forward direction by an angle γ (i.e., an angle γ counterclockwise when viewed from the front side of the paper in Figures 14 and 15), a similar effect to the first effect (hereinafter, this effect will also be referred to as a "second effect").

[0167] Furthermore, the servo pattern tilt information SF1 stored in the cartridge memory 24 of the magnetic tape cartridge 12 according to this embodiment includes information on the angle θa of the linear magnetized region 60A1 relative to the virtual line C1 and information on the angle θb of the linear magnetized region 60A2 relative to the virtual line C1. Therefore, according to this configuration, a more reliable servo pattern signal can be obtained compared to when only information on the tilt angle of either the linear magnetized region 60A1 or 60A2 relative to the virtual line C1 is taken into consideration, or when only information on the tilt angle of either the linear magnetized region 60B1 or 60B2 relative to the virtual line C2 is taken into consideration.

[0168] However, if the positions of both ends of the linear magnetization region 60A1 and the positions of both ends of the linear magnetization region 60A2 are not aligned in the width direction WD, the servo read element SR will read one end of the linear magnetization region 60A1 but not one end of the linear magnetization region 60A2, or the servo read element SR will read the other end of the linear magnetization region 60A1 but not the other end of the linear magnetization region 60A2.

[0169] Therefore, in the magnetic tape MT included in the magnetic tape cartridge 12 according to this embodiment, the positions of both ends of the linear magnetized region 60A1 (i.e., the positions of both ends of each of the five magnetized straight lines 60A1a) and the positions of both ends of the linear magnetized region 60A2 (i.e., the positions of both ends of each of the five magnetized straight lines 60A2a) are aligned in the width direction WD within the servo band SB. Therefore, when the servo read element SR reads the servo pattern 58A, the servo read element SR can read the linear magnetized regions 60A1 and 60A2 without excess or deficiency, compared to when the positions of both ends of the linear magnetized region 60A1 and the positions of both ends of the linear magnetized region 60A2 are not aligned in the width direction WD. As a result, a more reliable servo pattern signal can be obtained than when the positions of both ends of the linear magnetized region 60A1 and the positions of both ends of the linear magnetized region 60A2 are not aligned in the width direction WD (hereinafter, this effect will be referred to as the "third effect"). When the servo pattern 58B is read by the servo read element SR, an effect similar to the third effect (hereinafter, this effect may also be referred to as a "fourth effect") is obtained.

[0170] 9 and 10 , even though the gradient of the linear magnetization region 60A1 relative to the virtual line C1 is steeper than the gradient of the linear magnetization region 60A2 relative to the virtual line C1, if the total length of the linear magnetization region 60A1 is made longer than the total length of the linear magnetization region 60A2, some parts will be read by the servo read element SR and some will not be read between the linear magnetization region 60A1 and the linear magnetization region 60A2. Even if the total length of the linear magnetization region 60B1 is made longer than the total length of the linear magnetization region 60B2, some parts will be read by the servo read element SR and some will not be read between the linear magnetization region 60B1 and the linear magnetization region 60B2. Therefore, in the magnetic tape MT according to this embodiment, the total length of the linear magnetization region 60A1 is made shorter than the total length of the linear magnetization region 60A2, and the total length of the linear magnetization region 60B1 is made longer than the total length of the linear magnetization region 60B2. This allows the servo read element SR to read the linear magnetized regions 60A1 and 60A2 and the linear magnetized regions 60B1 and 60B2 without excess or deficiency (hereinafter, this effect is referred to as the "fifth effect").

[0171] Furthermore, in the magnetic tape MT included in the magnetic tape cartridge 12 according to this embodiment, the linear magnetization region 60A1 is a collection of five magnetization lines 60A1a, and the linear magnetization region 60A2 is a collection of five magnetization lines 60A2a. The linear magnetization region 60B1 is a collection of four magnetization lines 60B1a, and the linear magnetization region 60B2 is a collection of four magnetization lines 60B2a. Therefore, compared to when each linear magnetization region is made up of a single magnetization line, the amount of information obtained from the servo pattern 58 can be increased, resulting in highly accurate servo control (hereinafter, this effect will be referred to as the "sixth effect").

[0172] Furthermore, in the magnetic tape MT included in the magnetic tape cartridge 12 according to this embodiment, the geometric characteristics of the linear magnetization region pair 60A on the magnetic tape MT correspond to the geometric characteristics obtained by aligning the positions of both ends of the virtual linear region 62A and the positions of both ends of the virtual linear region 62B in the width direction WD when the symmetry axis SA1 of the virtual linear region pair 62 is tilted relative to the virtual line C1, thereby tilting the entire virtual linear region pair 62 relative to the virtual line C1. Therefore, compared to when the servo read element SR reads a servo pattern 52A having a conventionally known geometric characteristic, it is possible to reduce the variation between the servo pattern signals derived from the linear magnetization region 60A1 and the linear magnetization region 60A2. As a result, it is possible to obtain a servo pattern signal with higher reliability than a servo pattern signal obtained from a servo pattern 52A having a conventionally known geometric characteristic (hereinafter, this effect will be referred to as the "seventh effect").

[0173] The linear magnetization region pair 60B differs from the linear magnetization region pair 60A only in that it has a linear magnetization region 60B1 instead of the linear magnetization region 60A1 and a linear magnetization region 60B2 instead of the linear magnetization region 60A2. The linear magnetization region pair 60B configured in this manner is also read by the servo read element SR in the same way as the linear magnetization region pair 60A. Therefore, with this configuration, the variation in the servo pattern signal is reduced compared to when the servo pattern 58 is read without taking into account information about the tilt of the servo pattern 58, resulting in a highly reliable servo pattern signal.

[0174] The linear magnetization region pair 60B differs from the linear magnetization region pair 60A only in that it has a linear magnetization region 60B1 instead of the linear magnetization region 60A1 and a linear magnetization region 60B2 instead of the linear magnetization region 60A2. The servo read element SR reads the linear magnetization region pair 60B configured in this manner, just like the linear magnetization region pair 60A. Therefore, the variation between the servo pattern signals derived from the linear magnetization region 60B1 and the servo pattern signals derived from the linear magnetization region 60B2 can be reduced compared to when the servo read element SR reads the servo pattern 52B having a conventionally known geometric characteristic. As a result, a servo pattern signal with higher reliability can be obtained than the servo pattern signal obtained from the servo pattern 52B having a conventionally known geometric characteristic (hereinafter, this effect will be referred to as the "eighth effect").

[0175] Furthermore, the pair of linear magnetized regions 60B is read by the servo read element SR in the same manner as the pair of linear magnetized regions 60A. Therefore, compared to when the servo read element SR reads the servo pattern 52B having a conventionally known geometric characteristic, it is possible to reduce the variation between the servo pattern signals derived from the linear magnetized regions 60B1 and the servo pattern signals derived from the linear magnetized regions 60B2. As a result, it is possible to obtain a servo pattern signal with higher reliability than the servo pattern signal obtained from the servo pattern 52B having a conventionally known geometric characteristic.

[0176] In this embodiment, the servo pattern signal, which is the result of the servo read element SR reading the servo pattern 58, is detected using an autocorrelation coefficient (see FIG. 17). This allows the servo pattern signal to be detected with higher accuracy than when the servo pattern signal is detected using only a method of determining whether the signal level exceeds a threshold (hereinafter, this effect will be referred to as the "ninth effect").

[0177] The magnetic tape cartridge 12 according to this embodiment has a cartridge memory 24. Servo format information SF is stored in the cartridge memory 24. Therefore, according to this configuration, the magnetic tape cartridge 12 can have a simpler configuration than when a separate means for storing the servo format information SF is provided in the magnetic tape cartridge 12.

[0178] [First Modification] In the first embodiment described above, an example was given in which the control unit 30A performs various controls, such as servo control, skew angle control, and / or tension control, based on the position detection result of the servo read element SR by the position detection unit 30B. However, the technology of the present disclosure is not limited to this. In this first modified example, instead of detecting the position of the servo read element SR by the position detection unit 30B, the PES calculation unit 30C calculates the PES from the servo band signal S. Then, the control unit 30A performs various controls based on the PES calculation result by the PES calculation unit 30C.

[0179] First, as described above, the position detection unit 30B detects the servo pattern signal SP from the servo band signal S using the autocorrelation coefficient. Then, as shown in FIG. 20 as an example, the position detection unit 30B outputs the servo pattern signal SP to the PES calculation unit 30C. Here, the servo pattern signal SP includes a first servo pattern signal SP1 detected by the first position detection unit 30B1 (see FIG. 16) and a second servo pattern signal SP2 detected by the second position detection unit 30B2 (see FIG. 16).

[0180] The control device 30 includes a PES calculation unit 30C. The PES calculation unit 30C calculates a PES based on the servo pattern signal SP acquired from the position detection unit 30B. For example, the PES calculation unit 30C calculates a first PES based on the first servo pattern signal SP1 input from the first position detection unit 30B1. The PES calculation unit 30C also calculates a second PES based on the second servo pattern signal SP2 input from the second position detection unit 30B2.

[0181] The first PES refers to a PES signal that indicates the amount of deviation of the servo read element SR1 from its original position along the width direction WD on the servo band SB2. The second PES refers to a PES signal that indicates the amount of deviation of the servo read element SR2 from its original position along the width direction WD on the servo band SB3. For ease of explanation, when there is no need to distinguish between the first PES and the second PES, they will be referred to as "PES."

[0182] The PES is calculated using the following formula (1):

[0183]

number

[0184] θ shown in Equation (1) Ai is the angle of the linear magnetization region 60A1 with respect to the virtual line C1. Bi As described above, θ is the angle of the linear magnetization region 60A2 with respect to the virtual line C1. Ai corresponds to θa shown in FIG. 11, and θ Bi corresponds to θb shown in FIG.

[0185] In formula (1), the second distance Ai refers to, for example, a distance calculated from the results obtained by reading, with the servo read element SR, the magnetization straight line 60A1a on the most downstream side of the linear magnetization region 60A1 and the magnetization straight line 60A2a on the most downstream side of the linear magnetization region 60A2 in one servo pattern 58A. The first distance Bi refers to, for example, a distance calculated from the results obtained by reading, with the servo read element SR, the magnetization straight line 60A1a on the most downstream side of one servo pattern 58A of the servo patterns 58 and the magnetization straight line 60B1a on the most downstream side of the adjacent servo pattern 58B.

[0186] The control unit 30A detects the position of the servo read element SR relative to the servo band SB based on the PES calculated by the PES calculation unit 30C. The control unit 30A detects the position of the servo read element SR1 relative to the servo band SB2 based on the first PES. The control unit 30A also detects the position of the servo read element SR2 relative to the servo band SB3 based on the second PES. Furthermore, the control unit 30A performs various controls such as servo control, skew angle control, and / or tension control based on the position detection results of the servo read element SR relative to the servo band SB (see FIG. 17).

[0187] As described above, according to the first modification, the control unit 30A detects the position of the servo read element SR relative to the servo band SB using the PES calculated by the PES calculation unit 30C. Furthermore, the control unit 30A performs various controls, such as servo control, skew angle control, and / or tension control, based on the results of the position detection of the servo read element SR. This adjusts the position of the servo read element SR on the servo band SB. Therefore, according to this configuration, the position of the servo read element SR relative to the servo pattern 58 is maintained at a predetermined position determined by design.

[0188] Furthermore, according to this first modified example, the PES is calculated based on the above formula (1). The above formula (1) is an equation that takes into account the inclination of the servo pattern 58. Therefore, by using the above formula (1), it is possible to calculate the PES taking into account the inclination of the servo pattern 58. As a result, various controls are performed based on the result of calculating the PES using the formula that takes into account the inclination of the servo pattern 58. Therefore, according to this configuration, the position of the servo read element SR with respect to the servo pattern 58 is maintained at a predetermined position that is determined by design.

[0189] [Second Modification] In the first embodiment described above, an example was given in which the servo format information SF includes servo pattern tilt information SF1, but the technology of the present disclosure is not limited to this. In the second modified example, the servo format information SF includes information about the width of the magnetic tape MT (hereinafter also referred to as magnetic tape width change information SF2) and information about the geometric characteristics of the servo patterns 58 (hereinafter also referred to as servo pattern geometric characteristic information SF3). The magnetic tape width change information SF2 is, for example, information indicating the width change in the overall length direction of the magnetic tape MT (i.e., the degree of width change over time). The servo pattern geometric characteristic information SF3 is, for example, information indicating the length, shape, orientation, and position of the servo patterns 58. The magnetic tape width change information SF2 is an example of "information about the width of the magnetic tape" according to the technology of the present disclosure, and the servo pattern geometric characteristic information SF3 is an example of "information about the geometric characteristics of the magnetic tape" according to the technology of the present disclosure.

[0190] As an example, as shown in FIG. 21, the cartridge memory 24 stores magnetic tape width variation information SF2 and servo pattern geometric characteristic information SF3. The control device 30 acquires the magnetic tape width variation information SF2 and the servo pattern geometric characteristic information SF3 from the cartridge memory 24 via the non-contact read / write device 46. The control device 30 operates the tilt mechanism 49 based on the magnetic tape width variation information SF2, thereby adjusting the magnetic head skew angle. For example, in areas where the width of the magnetic tape MT is narrower in the overall length direction of the magnetic tape MT, the tilt mechanism 49 increases the magnetic head skew angle from the tilt angle α of the servo patterns 58 indicated by the servo pattern tilt information SF1. On the other hand, in areas where the width of the magnetic tape MT is wider, the tilt mechanism 49 decreases the magnetic head skew angle from the tilt angle α of the servo patterns 58 indicated by the servo pattern tilt information SF1.

[0191] The control device 30 also operates the tilt mechanism 49 based on the servo pattern geometric characteristic information SF3, thereby adjusting the magnetic head skew angle. For example, the tilt mechanism 49 adjusts the magnetic head skew angle in response to a partial positional deviation (e.g., positional deviation in the width direction WD) or a change in orientation of the servo patterns 58 indicated by the servo pattern geometric characteristic information SF3 in the overall length direction of the magnetic tape MT.

[0192] As described above, according to the second modified example, the servo format information SF includes magnetic tape width variation information SF2 and servo pattern geometric characteristic information SF3. The control device 30 then acquires the magnetic tape width variation information SF2 and the servo pattern geometric characteristic information SF3 from the cartridge memory 24. The control device 30 controls the operation of the tilt mechanism 49 based on the magnetic tape width variation information SF2 and the servo pattern geometric characteristic information SF3. This adjusts the magnetic head skew angle. Therefore, according to this configuration, a more reliable servo pattern signal can be obtained compared to when the magnetic tape width variation information SF2 and the servo pattern geometric characteristic information SF3 are not taken into consideration.

[0193] In the second modified example, the servo format information SF includes the magnetic tape width variation information SF2 and the servo pattern geometric characteristic information SF3, but this is merely an example. The servo format information SF may include either the magnetic tape width variation information SF2 or the servo pattern geometric characteristic information SF3.

[0194] In addition, in the second modified example, the servo pattern geometric characteristic information SF3 includes information indicating the length, shape, orientation, and position of the servo pattern 58, but this is merely an example. As the servo pattern geometric characteristic information SF3, any one or more of the information indicating the length, shape, orientation, and position of the servo pattern 58 may be used as the servo pattern geometric characteristic information SF3.

[0195] [Third Modification] In the first embodiment described above, a configuration was described in which the servo format information SF includes servo pattern tilt information SF1, which is information regarding the tilt of the servo pattern 58, but the technology of the present disclosure is not limited to this. In the present third modified example, as shown in FIG. 22 as an example, the servo format information SF includes information SF4 for adjusting the width of the magnetic tape (hereinafter also referred to as "width adjustment information SF4"). The width adjustment information SF4 refers to information for adjusting the width W of the magnetic tape MT (i.e., the distance along the width direction WD of the magnetic tape MT; hereinafter also simply referred to as "tape width W") (i.e., information used to adjust the tape width W). Note that the width adjustment information SF4 is an example of "width adjustment information" according to the technology of the present disclosure.

[0196] As described above, the magnetic tape MT expands and contracts in the width direction WD due to factors such as the pressure of being wound around a cartridge reel (not shown), temperature, humidity, and deterioration over time. This may cause the tilt angle α of the servo patterns 58 to change. Therefore, even if the magnetic head skew angle is adjusted based on the servo pattern tilt information SF1 included in the servo format information SF, the tilt angle α of the servo patterns 58 may not become close to the magnetic head skew angle (i.e., the magnetic head skew angle may be outside the allowable range). This may result in a decrease in the reliability of the servo pattern signal.

[0197] Therefore, the servo format information SF according to the third modified example includes width adjustment information SF4. The width adjustment information SF4 is stored in the cartridge memory 24. The width adjustment information SF4 includes tension information SF4a, for example, as shown in FIG. 23. The tension information SF4a refers to information relating to the tension in the overall length direction of the magnetic tape MT. An example of the tension information SF4a is information indicating the tension that existed in the magnetic tape MT when the servo patterns 58 were recorded on the magnetic tape MT, but this is merely an example. The tension information SF4a may also be information indicating the tension that existed in the magnetic tape MT when the magnetic tape MT was used in the past (for example, at a time specified from the usage history of the magnetic tape MT). The tension information SF4a is an example of "information relating to the tension in the overall length direction of the magnetic tape" according to the technology of the present disclosure.

[0198] As an example, as shown in FIG. 22, the control device 30 acquires width adjustment information SF4 from the cartridge memory 24 via the non-contact read / write device 46. The control device 30 performs tension control based on the width adjustment information SF4. Tension control is achieved by adjusting the rotational speed and / or rotational torque of each of the feed motor 36 and the take-up motor 40. For example, the control device 30 increases the tension applied to the magnetic tape MT when the magnetic tape MT expands in the width direction WD. Furthermore, the control device 30 decreases the tension applied to the magnetic tape MT when the magnetic tape MT contracts in the width direction WD. This adjusts the width W of the magnetic tape MT.

[0199] As described above, according to the third modified example, the servo format information SF includes width adjustment information SF4, which is information for adjusting the tape width W. The width adjustment information SF4 is stored in the cartridge memory 24. The control device 30 acquires the width adjustment information SF4 from the cartridge memory 24. The control device 30 then performs tension control based on the width adjustment information SF4 acquired from the cartridge memory 24. This adjusts the width W of the magnetic tape MT, so that the tilt angle α of the servo pattern 58 and the magnetic head skew angle become closer to each other even if the width W of the magnetic tape MT expands or contracts.

[0200] In the third modified example, the tension information SF4a is information about the tension of the magnetic tape MT when the servo patterns 58 are recorded on the magnetic tape MT or when the magnetic tape MT has been used in the past. However, the technology of the present disclosure is not limited to this. For example, the tension information SF4a is determined based on various factors that affect the tension of the magnetic tape MT.

[0201] As an example, as shown in FIG. 24, tension influencing factor information TF is stored in the cartridge memory 24. The tension influencing factor information TF indicates factors that affect the tension acting on the magnetic tape MT. The tension influencing factor information TF includes magnetic tape width information TF1, magnetic tape characteristic information TF2, usage history information TF3, temperature information TF4, and humidity information TF5. The magnetic tape width information TF1 indicates information indicating the width W of the magnetic tape MT. The magnetic tape characteristic information TF2 indicates information indicating the characteristics of the magnetic tape MT itself (e.g., expansion coefficient and / or material). The usage history information TF3 indicates information indicating the usage history of the magnetic tape MT (e.g., when it was used and / or how many times it was used). The temperature information TF4 indicates information indicating the temperature applied to the magnetic tape MT (e.g., the average temperature inside the case 16 when the magnetic tape cartridge 12 is stored). The humidity information TF5 indicates information indicating the humidity applied to the magnetic tape MT (e.g., the average humidity inside the case 16 when the magnetic tape cartridge 12 is stored).

[0202] The control device 30 acquires tension influencing factor information TF from the cartridge memory 24 via the non-contact read / write device 46. The control device 30 determines tension information SF4a in the overall length direction of the magnetic tape MT based on the tension influencing factor information TF. For example, the control device 30 may calculate the tension using a tension calculation formula or a tension table. The tension calculation formula refers to a calculation formula that uses, for example, magnetic tape width information TF1, magnetic tape characteristic information TF2, usage history information TF3, temperature information TF4, and humidity information TF5 as dependent variables and information indicating the tension in the overall length direction of the magnetic tape MT as independent variables. The tension table refers to a table that uses magnetic tape width information TF1, magnetic tape characteristic information TF2, usage history information TF3, temperature information TF4, and humidity information TF5 as input values ​​and information indicating the tension in the overall length direction of the magnetic tape MT as output values. The control device 30 controls the tension based on the tension information SF4a.

[0203] As described above, in the third modified example, the control device 30 determines tension information SF4a based on tension influencing factor information TF acquired from the cartridge memory 24. The control device 30 then performs tension control based on the tension information SF4a. This adjusts the width W of the magnetic tape MT, so that even if the width W of the magnetic tape MT expands or contracts, the tilt angle α of the servo patterns 58 and the magnetic head skew angle can be made closer to each other.

[0204] Although the above example uses magnetic tape width information TF1, magnetic tape characteristic information TF2, usage history information TF3, temperature information TF4, and humidity information TF5 as tension influencing factor information TF, this is merely an example. For example, any one or a combination of two or more of magnetic tape width information TF1, magnetic tape characteristic information TF2, usage history information TF3, temperature information TF4, and humidity information TF5 may be used as tension influencing factor information TF.

[0205] [Fourth Modification] In the first embodiment described above, the servo format information SF includes servo pattern tilt information SF1, which is information about the tilt of the servo pattern 58, but the technology of the present disclosure is not limited to this. In the present fourth modification, as an example, as shown in FIG. 25, the servo format information SF includes skew angle information SF5. The skew angle information SF5 refers to information about the skew angle of the magnetic head 28. The skew angle information SF5 is an example of "information about the skew angle" according to the technology of the present disclosure.

[0206] Even for magnetic tapes MT manufactured under the same conditions, differences in the tilt angle α of the servo patterns 58 may occur due to individual differences in the servo pattern recording heads WH. Furthermore, as mentioned above, the tilt angle α of the servo patterns 58 may also change due to expansion and contraction of the magnetic tape MT in the width direction. Therefore, even if the magnetic head skew angle is adjusted based on the servo pattern tilt information SF1 included in the servo format information SF, the tilt angle α of the servo patterns 58 may not become close to the magnetic head skew angle. This may result in a decrease in the reliability of the servo pattern signal.

[0207] Therefore, the servo format information SF according to the fourth modification includes skew angle information SF5. The skew angle information SF5 is stored in the cartridge memory 24. The skew angle information SF5 is information indicating the angle difference (hereinafter simply referred to as the "skew angle difference") between the tilt angle α of the servo pattern 58 determined based on the servo pattern tilt information SF1 and the tilt angle α of the servo pattern 58 changed due to various influences. The skew angle information SF5 may be, for example, information indicating the skew angle difference according to the individual number of the servo pattern recording head WH, but this is merely one example. For example, the skew angle information SF5 may be information indicating the skew angle difference according to the degree of expansion and contraction of the magnetic tape MT in the width direction.

[0208] The control device 30 acquires the skew angle information SF5 from the cartridge memory 24 via the non-contact read / write device 46. The control device 30 performs skew angle control based on the skew angle information SF5. For example, the tilt mechanism 49 changes the magnetic head skew angle by the angle difference obtained based on the skew angle information SF5. That is, the tilt mechanism 49 adjusts the angle between the virtual lines C1 and C3 from angle γ (see FIG. 15) to the adjusted angle γ1. This brings the tilt angle α of the servo pattern 58 closer to the magnetic head skew angle.

[0209] As described above, according to the fourth modification, the servo format information SF includes skew angle information SF5. The control device 30 acquires the skew angle information SF5 from the cartridge memory 24. The control device 30 then controls the skew angle of the magnetic head 28 based on the skew angle information SF5 acquired from the cartridge memory 24. This causes the tilt angle α of the servo pattern 58 to become closer to the magnetic head skew angle.

[0210] In the fourth modified example, an example was described in which information indicating a skew angle difference according to the individual number of the servo pattern recording head WH is used as the skew angle information SF5, but the technology of the present disclosure is not limited to this. For example, the skew angle information SF5 is determined based on various factors that affect the tilt angle α of the servo pattern 58. In the example shown in Fig. 26, information on factors that affect the tilt angle α of the servo pattern 58 (hereinafter also simply referred to as "angle influence factor information DF") is stored in the cartridge memory 24.

[0211] The angle influencing factor information DF includes magnetic tape width information DF1, magnetic tape characteristic information DF2, usage history information DF3, temperature information DF4, and humidity information DF5. The magnetic tape width information DF1 indicates the width W of the magnetic tape MT (see FIG. 22). The magnetic tape characteristic information DF2 indicates the characteristics of the magnetic tape MT itself (e.g., the expansion coefficient and / or the material). The usage history information DF3 indicates the usage history of the magnetic tape MT (e.g., the time of use and / or the number of times it has been used). The temperature information DF4 indicates the temperature applied to the magnetic tape MT (e.g., the average temperature inside the case 16 when the magnetic tape cartridge 12 is stored). The humidity information DF5 indicates the humidity applied to the magnetic tape MT (e.g., the average humidity inside the case 16 when the magnetic tape cartridge 12 is stored).

[0212] The control device 30 acquires the angle influencing factor information DF from the cartridge memory 24 via the non-contact read / write device 46. The control device 30 determines the skew angle information SF5 in accordance with the angle influencing factor information DF. For example, the control device 30 may derive the angle difference using an angle difference calculation formula or an angle difference table. The angle difference calculation formula refers to a calculation formula that uses, for example, magnetic tape width information DF1, magnetic tape characteristic information DF2, usage history information DF3, temperature information DF4, and humidity information DF5 as dependent variables and skew angle information SF5 as an independent variable. The tension table refers to a table that uses the magnetic tape width information DF1, magnetic tape characteristic information DF2, usage history information DF3, temperature information DF4, and humidity information DF5 as input values ​​and skew angle information SF5 as an output value. The control device 30 determines the skew angle information SF5 in accordance with the angle influencing factor information DF. The control device 30 controls the skew angle of the magnetic head 28 based on the skew angle information SF5.

[0213] As described above, in the fourth modification, the control device 30 determines the skew angle information SF5 in accordance with the angle influencing factor information DF acquired from the cartridge memory 24. Then, the control device 30 performs skew angle control based on the skew angle information SF5. As a result, the tilt angle α of the servo pattern 58 and the magnetic head skew angle become closer to each other.

[0214] Although the magnetic tape width information DF1, magnetic tape characteristic information DF2, usage history information DF3, temperature information DF4, and humidity information DF5 are used as the angle influencing factor information DF in the above example, this is merely an example. For example, any one or more of the magnetic tape width information DF1, magnetic tape characteristic information DF2, usage history information DF3, temperature information DF4, and humidity information DF5 may be combined and used as the angle influencing factor information DF.

[0215] [Fifth Modification] In the above embodiment, the servo format information SF includes the servo pattern tilt information SF1, but the technology of the present disclosure is not limited to this. In this fifth modification, the servo format information SF includes an ideal waveform signal 67 that indicates an ideal waveform of the servo pattern signal that is the result of the servo pattern 58 being read by the servo read element SR.

[0216] As described above, if there is a large discrepancy between the tilt angle α of the servo pattern 58 and the magnetic head skew angle (for example, if the tilt angle α of the servo pattern 58 is 5 degrees and the magnetic head skew angle is 10 degrees), variations in the servo pattern signal due to azimuth loss may occur (see FIG. 13). Such variations in the servo pattern signal may be one factor that reduces the accuracy of servo control.

[0217] As described above, the variations in the servo pattern signal due to the azimuth loss (for example, variations in the signal level and distortion of the waveform) are caused by the difference between the tilt angle α of the servo pattern 58 and the magnetic head skew angle. In other words, the variations in the servo pattern signal reflect the difference between the tilt angle α of the servo pattern 58 and the magnetic head skew angle.

[0218] Therefore, in the present fifth modified example, the servo format information SF includes an ideal waveform signal 67 that indicates an ideal waveform of the servo pattern signal according to the tilt angle α of the servo pattern 58. In addition, the control unit 30A calculates the tilt angle α of the servo pattern 58.

[0219] 27, the control device 30 has an angle detection unit 30D. The angle detection unit 30D acquires a servo band signal S resulting from the servo read element SR reading the servo band SB, and detects the angle of the servo read element SR relative to the servo band SB on the magnetic tape MT based on the acquired servo band signal S. The angle detection unit 30D has a first angle detection unit 30D1 and a second angle detection unit 30D2.

[0220] The first angle detection unit 30D1 acquires a first servo band signal S1, and the second angle detection unit 30D2 acquires a second servo band signal S2. In the example shown in FIG. 27, the first angle detection unit 30D1 acquires the first servo band signal S1 obtained by the servo read element SR1 reading the servo pattern 58 in the servo band SB2. The second angle detection unit 30D2 acquires the second servo band signal S2 obtained by the servo read element SR2 reading the servo pattern 58 in the servo band SB3. The first angle detection unit 30D1 detects the angle of the servo read element SR1 with respect to the servo band SB2 based on the first servo band signal S1, and the second angle detection unit 30D2 detects the angle of the servo read element SR2 with respect to the servo band SB3 based on the second servo band signal S2.

[0221] As an example, as shown in Figure 28, the angle detection unit 30D calculates the tilt angle α of the servo pattern 58 using the ideal waveform signal and autocorrelation coefficient from the servo pattern signal, which is the result of the servo pattern 58 being read from the magnetic tape MT by the servo read element SR.

[0222] Next, a specific configuration example of the first angle detection unit 30D1 will be described. Note that the configuration of the second angle detection unit 30D2 is the same as the configuration of the first angle detection unit 30D1, so a description of a specific configuration example of the second angle detection unit 30D2 will be omitted. Furthermore, for convenience of explanation, hereinafter, the servo pattern signal derived from the linear magnetization region 60A1 or 60B1 (see FIGS. 9 and 10) will also be referred to as the "first linear magnetization region signal," and the servo pattern signal derived from the linear magnetization region 60A2 or 60B2 (see FIGS. 9 and 10) will also be referred to as the "second linear magnetization region signal."

[0223] As an example, as shown in FIG. 28, the first angle detection unit 30D1 includes a first detection circuit 39A and a second detection circuit 39B. The first detection circuit 39A and the second detection circuit 39B are connected in parallel and share a common input terminal 30E1a and output terminal 30E1b. The example shown in FIG. 28 illustrates an example in which a first servo band signal S1 is input to the input terminal 30E1a. The first servo band signal S1 includes a first linear magnetization region signal S1a and a second linear magnetization region signal S1b. The first linear magnetization region signal S1a and the second linear magnetization region signal S1b are servo pattern signals (i.e., analog servo pattern signals) read by the servo read element SR1 (see FIG. 27). That is, the servo pattern signal includes the first linear magnetization region signal S1a and the second linear magnetization region signal S1b.

[0224] The cartridge memory 24 stores an ideal waveform signal 67 corresponding to the tilt angle α of the servo pattern 58. That is, the servo format information SF stored in the cartridge memory 24 includes the ideal waveform signal 67. The ideal waveform signal 67 is a signal indicating a single ideal waveform included in the servo band signal S corresponding to the tilt angle α of the servo pattern 58 (for example, an ideal signal resulting from reading, by the servo read element SR, one of the ideal magnetization lines included in the servo pattern 58 that is tilted at a predetermined angle with respect to the virtual line C1). The ideal waveform signal 67 can also be said to be a sample signal corresponding to the tilt angle α of the servo pattern 58 that is compared with the servo band signal S. The ideal waveform signal 67 is an example of an "ideal waveform signal" according to the technology of the present disclosure.

[0225] The ideal waveform represented by the first ideal waveform signal 67A is a waveform determined according to the orientation of the magnetic head 28 on the magnetic tape MT. The relative positional relationship between the holder 44 (see FIG. 8) of the magnetic head 28 and the servo read element SR is fixed. Therefore, the ideal waveform represented by the first ideal waveform signal 67A can also be said to be a waveform determined according to the orientation of the servo read element SR on the magnetic tape MT. In other words, the ideal waveform represented by the first ideal waveform signal 67A is a waveform corresponding to the tilt angle α of the servo pattern 58. For example, the ideal waveform represented by the first ideal waveform signal 67A is a waveform determined according to the tilt angle θa of the linear magnetization region 60A1 of the servo pattern 58.

[0226] As described above, since the relative positional relationship between the holder 44 (see FIG. 8) of the magnetic head 28 and the servo read element SR is fixed, the ideal waveform represented by the first ideal waveform signal 67A can also be said to be a waveform determined according to the geometric characteristics of the linear magnetized region pair 60A of the servo pattern 58 (e.g., the geometric characteristics of the magnetized straight line 60A1a) and the orientation of the servo read element SR on the magnetic tape MT. Here, the orientation of the magnetic head 28 on the magnetic tape MT refers, for example, to the angle formed by the linear magnetized region 60A1 and the magnetic head 28 on the magnetic tape MT. Also, the orientation of the servo read element SR on the magnetic tape MT refers, for example, to the angle formed by the linear magnetized region 60A1 and the servo read element SR on the magnetic tape MT.

[0227] Like the ideal waveform represented by the first ideal waveform signal 67A, the ideal waveform represented by the second ideal waveform signal 67B is also a waveform determined according to the orientation of the magnetic head 28 on the magnetic tape MT, i.e., a waveform determined according to the orientation of the servo read element SR on the magnetic tape MT. In other words, the ideal waveform represented by the second ideal waveform signal 67B is a waveform corresponding to the tilt angle α of the servo pattern 58. For example, the ideal waveform represented by the second ideal waveform signal 67B is a waveform determined according to the tilt angle θb of the linear magnetized region 60A2 of the servo pattern 58.

[0228] For example, the ideal waveform represented by the second ideal waveform signal 67B is a waveform determined according to the geometric characteristics of the linear magnetization region 60A2 of the servo pattern 58A (e.g., the geometric characteristics of the magnetization straight line 60A2a) and the orientation of the magnetic head 28 on the magnetic tape MT. That is, the waveform determined according to the geometric characteristics of the linear magnetization region 60A2 of the servo pattern 58A (e.g., the geometric characteristics of the magnetization straight line 60A2a) and the orientation of the servo read element SR on the magnetic tape MT. Here, the orientation of the magnetic head 28 on the magnetic tape MT refers to, for example, the angle formed between the linear magnetization region 60A2 and the magnetic head 28 on the magnetic tape MT. Also, the orientation of the servo read element SR on the magnetic tape MT refers to, for example, the angle formed between the linear magnetization region 60A2 and the servo read element SR on the magnetic tape MT.

[0229] The first angle detection unit 30D1 calculates the angle between the linear magnetization region 60A1 in the servo band SB3 and the servo read element SR by comparing the first servo band signal S1 with the ideal waveform signal 67. In the example shown in Fig. 28, the first angle detection unit 30D1 detects the tilt angle α of the servo pattern 58 by using the first detection circuit 39A and the second detection circuit 39B.

[0230] The first detection circuit 39A receives the first servo band signal S1 via the input terminal 30B1a and detects the tilt angle θa of the linear magnetization region 60A1 in the servo pattern 58 of the servo band SB3 from the received first servo band signal S1 using an autocorrelation coefficient.

[0231] The autocorrelation coefficient used by the first detection circuit 39A is a coefficient indicating the degree of correlation between the first servo band signal S1 and the first ideal waveform signal 67A. The first detection circuit 39A acquires the first ideal waveform signal 67A from the cartridge memory 24 and compares the acquired first ideal waveform signal 67A with the first servo band signal S1. The first detection circuit 39A then calculates the autocorrelation coefficient based on the comparison result. The first detection circuit 39A detects the ideal waveform signal on the servo band SB2 that has the highest correlation with the first servo band signal S1 according to the autocorrelation coefficient. The first detection circuit 39A outputs the tilt angle θa of the linear magnetization region 60A1 corresponding to the detected ideal waveform signal.

[0232] Meanwhile, the first servo band signal S1 is also input to the second detection circuit 39B via the input terminal 30B1a. The second detection circuit 39B detects the tilt angle θb of the linear magnetization region 60A2 in the servo pattern 58 of the servo band SB2 from the input first servo band signal S1 using an autocorrelation coefficient.

[0233] The autocorrelation coefficient used by the second detection circuit 39B is a coefficient indicating the degree of correlation between the first servo band signal S1 and the second ideal waveform signal 67B. The second detection circuit 39B acquires the second ideal waveform signal 67B from the storage 32 and compares the acquired second ideal waveform signal 67B with the first servo band signal S1. The second detection circuit 39B then calculates the autocorrelation coefficient based on the comparison result. The second detection circuit 39B detects the ideal waveform signal on the servo band SB2 that has the highest correlation with the first servo band signal S1 according to the autocorrelation coefficient. The second detection circuit 39B outputs the tilt angle θb of the linear magnetization region 60A2 corresponding to the detected ideal waveform signal.

[0234] As an example, as shown in FIG. 29, the first angle detection unit 30D1 detects the inclination angle θa of the linear magnetization region 60A1 and the inclination angle θb of the linear magnetization region 60A2 based on the detection results by the first detection circuit 39A and the detection results by the second detection circuit 39B.

[0235] The tilt angle α of the servo pattern 58 is output from the output terminal 30B1b to the control unit 30A. The control device 30 also has a PES calculation unit 30C. The PES calculation unit 30C calculates the PES using the tilt angle θa of the linear magnetization region 60A1 and the tilt angle θb of the linear magnetization region 60A2 acquired from the angle detection unit 30D, and the above formula (1). That is, θ in the above formula (1) Ai The inclination angle θa of the linear magnetization region 60A1 is used as θ Bi The tilt angle θb of the linear magnetization region 60A2 is used as the angle θb.

[0236] 29, the control unit 30A adjusts the skew angle of the magnetic head 28 by operating the tilt mechanism 49 (see FIG. 14) based on the PES calculation result by the PES calculation unit 30C. The control unit 30A also causes the magnetic element unit 42 (see FIG. 17) to perform magnetic processing on the data band DB of the magnetic tape MT. That is, the control unit 30A obtains a read signal from the magnetic element unit 42 (i.e., data read from the data band DB of the magnetic tape MT by the magnetic element unit 42) and supplies a recording signal to the magnetic element unit 42 to record data corresponding to the recording signal on the data band DB of the magnetic tape MT.

[0237] Furthermore, to reduce the effects of TDS, the control unit 30A performs tension control and skews the magnetic head 28 (see FIG. 14) on the magnetic tape MT in accordance with the angle detection result from the angle detection unit 30D. Tension control is achieved by adjusting the rotation speed and rotation torque of the feed motor 36 (see FIG. 3) and the take-up motor 40 (see FIG. 3). Skew of the magnetic head 28 is achieved by operating a tilt mechanism 49 (see FIG. 14).

[0238] As described above, in the fifth modified example, a waveform determined according to the orientation of the magnetic head 28 on the magnetic tape MT, i.e., the orientation of the tilt mechanism 49 on the magnetic tape MT, is used as the ideal waveform indicated by the ideal waveform signal 67. Therefore, according to this configuration, the servo pattern signal can be detected from the servo band signal S with higher accuracy than when the ideal waveform is determined independently of the orientation of the magnetic head 28 on the magnetic tape MT, i.e., the orientation of the servo read element SR on the magnetic tape MT.

[0239] In the fifth modified example, a waveform determined in accordance with the geometric characteristics of the servo patterns 58 and the orientation of the magnetic head 28 on the magnetic tape MT, i.e., the geometric characteristics of the servo patterns 58 and the orientation of the servo read elements SR on the magnetic tape MT, is used as the ideal waveform indicated by the ideal waveform signal 67. Therefore, according to this configuration, the servo pattern signal can be detected more accurately from the servo band signal S than when the ideal waveform is determined independently of the geometric characteristics of the servo patterns 58 and the orientation of the magnetic head 28 on the magnetic tape MT, i.e., the geometric characteristics of the servo patterns 58 and the orientation of the servo read elements SR on the magnetic tape MT.

[0240] In the fifth modification, the linear magnetization regions 60A1 and 60A2 tilted in opposite directions with respect to the virtual line C1 are read by the servo read element SR. In this case, as described above, variations due to azimuth loss occur between the first linear magnetization region signal S1a (see FIG. 28) and the second linear magnetization region signal S1b (see FIG. 28). In the fifth modification, the ideal waveform signal 67 is stored in the cartridge memory 24, and the tilt angle α of the servo pattern 58 is detected by comparing the servo pattern signal with the ideal waveform signal 67. Therefore, according to this configuration, even if the linear magnetization regions 60A1 and 60A2 tilted in opposite directions with respect to the virtual line C1 are read by the servo read element SR, the tilt angle α of the servo pattern 58 can be detected with higher accuracy than when the tilt angle α of the servo pattern 58 is detected using only a method of determining whether the signal level exceeds a threshold.

[0241] In the fifth modified example, the first detection circuit 39A and the second detection circuit 39B are connected in parallel, and a common servo band signal S is input to the first detection circuit 39A and the second detection circuit 39B. The first detection circuit 39A compares the servo band signal S with the first ideal waveform signal 67A to detect the tilt angle θa of the linear magnetization region 60A1, and the second detection circuit 39B compares the servo band signal S with the second ideal waveform signal 67B to detect the tilt angle θb of the linear magnetization region 60A2. For example, the first position detection unit 30B1 detects the tilt angle θa of the linear magnetization region 60A1 detected by the first detection circuit 39A and the tilt angle θb of the linear magnetization region 60A2 detected by the second detection circuit 39B. Furthermore, the second position detection unit 30B2 detects the tilt angle θa of the linear magnetization region 60A1 detected by the first detection circuit 39A and the tilt angle θb of the linear magnetization region 60A2 detected by the second detection circuit 39B. Therefore, with this configuration, the tilt angle α of the servo pattern 58 can be detected more quickly than when the tilt angle θa of the linear magnetization region 60A1 and the tilt angle θb of the linear magnetization region 60A2 are detected in sequence by sequentially comparing different ideal waveform signals with one servo band signal S.

[0242] [Sixth Modification] In the above embodiment, an example has been described in which a plurality of V-shaped servo patterns 58 are recorded on the servo band SB along the longitudinal direction LD of the magnetic tape MT, but the technology of the present disclosure is not limited to this. For example, as shown in FIG. 30 , the servo pattern 72 may be an M-shaped magnetized servo pattern. The servo band SB has a plurality of servo patterns 72 recorded along the longitudinal direction LD of the magnetic tape MT. The plurality of servo patterns 72 are arranged at regular intervals along the longitudinal direction LD of the magnetic tape MT, similar to the plurality of servo patterns 58.

[0243] 30, servo patterns 72A and 72B are shown as an example of a set of servo patterns 72. Each of the servo patterns 72A and 72B is a servo pattern magnetized in an M-shape. The servo patterns 72A and 72B are adjacent to each other along the longitudinal direction LD of the magnetic tape MT. The servo pattern 72A is located on the upstream side in the forward direction, and the servo pattern 72B is located on the downstream side in the forward direction.

[0244] 31, a servo pattern 72 is made up of linear magnetization region pairs 74. The linear magnetization region pairs 74 are classified into linear magnetization region pairs 74A and linear magnetization region pairs 74B. A servo pattern 72A is made up of a set of linear magnetization region pairs 74A. The set of linear magnetization region pairs 74A are arranged adjacent to each other along the longitudinal direction LD of the magnetic tape MT.

[0245] 31 , linear magnetization regions 74A1 and 74A2 are shown as an example of the linear magnetization region pair 74A. The linear magnetization region pair 74A is configured similarly to the linear magnetization region pair 60A described in the above embodiment, and has similar geometric characteristics to the linear magnetization region pair 60A. That is, the linear magnetization region 74A1 is configured similarly to the linear magnetization region 60A1 described in the above embodiment, and has similar geometric characteristics to the linear magnetization region 60A1, and the linear magnetization region 74A2 is configured similarly to the linear magnetization region 60A2 described in the above embodiment, and has similar geometric characteristics to the linear magnetization region 60A2.

[0246] In the example shown in Figure 31, the linear magnetization region pair 74A is an example of a "linear magnetization region pair" according to the technology of the present disclosure, the linear magnetization region 74A1 is an example of a "first linear magnetization region" according to the technology of the present disclosure, and the linear magnetization region 74A2 is an example of a "second linear magnetization region" according to the technology of the present disclosure.

[0247] The servo pattern 72B is made up of a pair of linear magnetized regions 74B, which are arranged adjacent to each other along the longitudinal direction LD of the magnetic tape MT.

[0248] 31 shows linear magnetization regions 74B1 and 74B2 as an example of the linear magnetization region pair 74B. The linear magnetization region pair 74B is configured similarly to the linear magnetization region pair 60B described in the above embodiment and has similar geometric characteristics. That is, the linear magnetization region 74B1 is configured similarly to the linear magnetization region 60B1 described in the above embodiment and has similar geometric characteristics to the linear magnetization region 60B1, and the linear magnetization region 74B2 is configured similarly to the linear magnetization region 60B2 described in the above embodiment and has similar geometric characteristics to the linear magnetization region 60B2.

[0249] In the example shown in Figure 31, linear magnetization region pair 74B is an example of a "linear magnetization region pair" according to the technology of the present disclosure, linear magnetization region 74B1 is an example of a "first linear magnetization region" according to the technology of the present disclosure, and linear magnetization region 74B2 is an example of a "second linear magnetization region" according to the technology of the present disclosure.

[0250] [Seventh Modification] In the example shown in Figure 32, an example has been described in which a plurality of M-shaped servo patterns 58 are recorded on the servo band SB along the longitudinal direction LD of the magnetic tape MT, but the technology of the present disclosure is not limited to this. For example, as shown in Figure 33, the servo pattern 72 may be a servo pattern magnetized in an N-shape. A plurality of servo patterns 78 are recorded on the servo band SB along the longitudinal direction LD of the magnetic tape MT. The plurality of servo patterns 78 are arranged at regular intervals along the longitudinal direction LD of the magnetic tape MT, similar to the plurality of servo patterns 72 (see Figure 30).

[0251] 32, servo patterns 78A and 78B are shown as an example of a set of servo patterns 78. Each of the servo patterns 78A and 78B is a servo pattern magnetized in an N-shape. The servo patterns 78A and 78B are adjacent to each other along the longitudinal direction LD of the magnetic tape MT. The servo pattern 78A is located on the upstream side in the forward direction, and the servo pattern 78B is located on the downstream side in the forward direction.

[0252] 33, the servo pattern 78 is made up of linear magnetization region groups 80. The linear magnetization region groups 80 are classified into linear magnetization region groups 80A and linear magnetization region groups 80B.

[0253] The servo pattern 78A is made up of a linear magnetization region group 80A. The linear magnetization region group 80A is made up of linear magnetization regions 80A1, 80A2, and 80A3. The linear magnetization regions 80A1, 80A2, and 80A3 are arranged adjacent to each other along the longitudinal direction LD of the magnetic tape MT. The linear magnetization regions 80A1, 80A2, and 80A3 are arranged in this order from the upstream side in the forward direction.

[0254] The linear magnetization regions 80A1 and 80A2 are configured similarly to the linear magnetization region pair 74A shown in Fig. 31 and have similar geometric characteristics. That is, the linear magnetization region 80A1 is configured similarly to the linear magnetization region 74A1 shown in Fig. 31 and has similar geometric characteristics, and the linear magnetization region 80A2 is configured similarly to the linear magnetization region 74A2 shown in Fig. 31 and has similar geometric characteristics. Furthermore, the linear magnetization region 80A3 is configured similarly to the linear magnetization region 80A1 and has similar geometric characteristics.

[0255] 33, linear magnetization regions 80A1 and 80A2 are an example of a "linear magnetization region pair" according to the technology of the present disclosure. In this case, linear magnetization region 80A1 is an example of a "first linear magnetization region" according to the technology of the present disclosure, and linear magnetization region 80A2 is an example of a "second linear magnetization region" according to the technology of the present disclosure. Linear magnetization regions 80A2 and 80A3 are also an example of a "linear magnetization region pair" according to the technology of the present disclosure. In this case, linear magnetization region 80A3 is an example of a "first linear magnetization region" according to the technology of the present disclosure, and linear magnetization region 80A2 is an example of a "second linear magnetization region" according to the technology of the present disclosure.

[0256] The servo pattern 78B is made up of a linear magnetization region group 80B. The linear magnetization region group 80B is made up of linear magnetization regions 80B1, 80B2, and 80B3. The linear magnetization regions 80B1, 80B2, and 80B3 are arranged adjacent to each other along the longitudinal direction LD of the magnetic tape MT. The linear magnetization regions 80B1, 80B2, and 80B3 are arranged in this order from the upstream side in the forward direction.

[0257] The linear magnetization regions 80B1 and 80B2 are configured similarly to the linear magnetization region pair 74B shown in Fig. 31 and have similar geometric characteristics. That is, the linear magnetization region 80B1 is configured similarly to the linear magnetization region 74B1 shown in Fig. 31 and has similar geometric characteristics, and the linear magnetization region 80B2 is configured similarly to the linear magnetization region 74B2 shown in Fig. 31 and has similar geometric characteristics. Furthermore, the linear magnetization region 80B3 is configured similarly to the linear magnetization region 80B1 and has similar geometric characteristics.

[0258] 33, linear magnetization regions 80B1 and 80B2 are an example of a "linear magnetization region pair" according to the technology of the present disclosure. In this case, linear magnetization region 80B1 is an example of a "first linear magnetization region" according to the technology of the present disclosure, and linear magnetization region 80B2 is an example of a "second linear magnetization region" according to the technology of the present disclosure. Linear magnetization regions 80B2 and 80B3 are also an example of a "linear magnetization region pair" according to the technology of the present disclosure. In this case, linear magnetization region 80B3 is an example of a "first linear magnetization region" according to the technology of the present disclosure, and linear magnetization region 80B2 is an example of a "second linear magnetization region" according to the technology of the present disclosure.

[0259] [Eighth Modification] In the above embodiment, an example has been described in which the positions of both ends of each of the four magnetization straight lines 60B1a and the positions of both ends of each of the four magnetization straight lines 60B2a in the servo pattern 58 are aligned, but the technology of the present disclosure is not limited to this. For example, as shown in Fig. 34, in the servo pattern 84, the overall position of the linear magnetization region 86A1 and the overall position of the linear magnetization region 86A2 may be offset in the width direction WD.

[0260] 34, a plurality of servo patterns 84 are recorded on the servo band SB along the longitudinal direction LD of the magnetic tape MT. The plurality of servo patterns 84 are arranged at regular intervals along the longitudinal direction LD of the magnetic tape MT, similar to the plurality of servo patterns 52 (see FIG. 6) recorded on the magnetic tape MT0 (see FIG. 6).

[0261] 34, servo patterns 84A and 84B are shown as an example of a set of servo patterns 84. The servo patterns 84A and 84B are adjacent to each other along the longitudinal direction LD of the magnetic tape MT. The servo pattern 84A is located on the upstream side in the forward direction, and the servo pattern 84B is located on the downstream side in the forward direction.

[0262] The servo pattern 84 is made up of linear magnetization region pairs 86. The linear magnetization region pairs 86 are classified into linear magnetization region pairs 86A and linear magnetization region pairs 86B. In the eighth modified example, the linear magnetization region pairs 86 are an example of the "linear magnetization region pairs" according to the technology of the present disclosure.

[0263] The servo pattern 84A is made up of a pair of linear magnetization regions 86A. In the example shown in Fig. 34, linear magnetization regions 86A1 and 86A2 are shown as an example of the pair of linear magnetization regions 86A. Each of the linear magnetization regions 86A1 and 86A2 is a linearly magnetized region.

[0264] In the eighth modified example, the linear magnetization region 86A1 is an example of a "first linear magnetization region" according to the technology of the present disclosure, and the linear magnetization region 86A2 is an example of a "second linear magnetization region" according to the technology of the present disclosure.

[0265] The linear magnetization regions 86A1 and 86A2 are tilted in opposite directions with respect to the virtual line C1. The linear magnetization regions 86A1 and 86A2 are non-parallel to each other and tilt at different angles with respect to the virtual line C1. The linear magnetization region 86A1 has a steeper tilt angle with respect to the virtual line C1 than the linear magnetization region 86A2. Here, "steep" means, for example, that the angle of the linear magnetization region 86A1 with respect to the virtual line C1 is smaller than the angle of the linear magnetization region 86A2 with respect to the virtual line C1.

[0266] Furthermore, the overall position of the linear magnetization region 86A1 and the overall position of the linear magnetization region 86A2 are misaligned in the width direction WD. That is, the positions of one end of the linear magnetization region 86A1 and one end of the linear magnetization region 86A2 are not aligned in the width direction WD, and the positions of the other end of the linear magnetization region 86A1 and the other end of the linear magnetization region 86A2 are not aligned in the width direction WD.

[0267] In the servo pattern 84A, the linear magnetization region 86A1 includes a plurality of magnetization lines 86A1a, and the linear magnetization region 86A2 includes a plurality of magnetization lines 86A2a. The number of magnetization lines 86A1a included in the linear magnetization region 86A1 is the same as the number of magnetization lines 86A2a included in the linear magnetization region 86A2.

[0268] The linear magnetization region 86A1 is a set of five magnetized straight lines 86A1a, and the linear magnetization region 86A2 is a set of five magnetized straight lines 86A2a.

[0269] In the servo band SB, the positions in the width direction WD of one end of all the magnetization straight lines 86A1a included in the linear magnetization region 86A1 are aligned, and the positions in the width direction WD of the other end of all the magnetization straight lines 86A1a included in the linear magnetization region 86A1 are also aligned. Also, in the servo band SB, the positions in the width direction WD of one end of all the magnetization straight lines 86A2a included in the linear magnetization region 86A2 are aligned, and the positions in the width direction WD of the other end of all the magnetization straight lines 86A2a included in the linear magnetization region 86A2 are also aligned.

[0270] The servo pattern 84B is made up of a pair of linear magnetization regions 86B. In the example shown in Fig. 34, linear magnetization regions 86B1 and 86B2 are shown as an example of the pair of linear magnetization regions 86B. Each of the linear magnetization regions 86B1 and 86B2 is a linearly magnetized region.

[0271] In the eighth modified example, the linear magnetization region 86B1 is an example of a "first linear magnetization region" according to the technology of the present disclosure, and the linear magnetization region 86B2 is an example of a "second linear magnetization region" according to the technology of the present disclosure.

[0272] The linear magnetization regions 86B1 and 86B2 are tilted in opposite directions with respect to the virtual line C2. The linear magnetization regions 86B1 and 86B2 are non-parallel to each other and tilt at different angles with respect to the virtual line C2. The linear magnetization region 86B1 has a steeper tilt angle with respect to the virtual line C2 than the linear magnetization region 86B2. Here, "steep" means, for example, that the angle of the linear magnetization region 86B1 with respect to the virtual line C2 is smaller than the angle of the linear magnetization region 86B2 with respect to the virtual line C2.

[0273] Furthermore, the overall position of the linear magnetization region 86B1 and the overall position of the linear magnetization region 86B2 are misaligned in the width direction WD. That is, the positions of one end of the linear magnetization region 86B1 and one end of the linear magnetization region 86B2 are not aligned in the width direction WD, and the positions of the other end of the linear magnetization region 86B1 and the other end of the linear magnetization region 86B2 are not aligned in the width direction WD.

[0274] In the servo pattern 84B, the linear magnetization region 86B1 includes a plurality of magnetization lines 86B1a, and the linear magnetization region 86B2 includes a plurality of magnetization lines 86B2a. The number of magnetization lines 86B1a included in the linear magnetization region 86B1 is the same as the number of magnetization lines 86B2a included in the linear magnetization region 86B2.

[0275] The total number of magnetization lines 86B1a and 86B2a included in the servo pattern 84B is different from the total number of magnetization lines 86A1a and 86A2a included in the servo pattern 84A. In the example shown in Fig. 34, the total number of magnetization lines 86A1a and 86A2a included in the servo pattern 84A is 10, while the total number of magnetization lines 86B1a and 86B2a included in the servo pattern 84B is 8.

[0276] The linear magnetization region 86B1 is a set of four magnetized straight lines 86B1a, and the linear magnetization region 86B2 is a set of four magnetized straight lines 86B2a.

[0277] In the servo band SB, the positions in the width direction WD of one end of all the magnetization straight lines 86B1a included in the linear magnetization region 86B1 are aligned, and the positions in the width direction WD of the other end of all the magnetization straight lines 86B1a included in the linear magnetization region 86B1 are also aligned. Also, in the servo band SB, the positions in the width direction WD of one end of all the magnetization straight lines 86B2a included in the linear magnetization region 86B2 are also aligned, and the positions in the width direction WD of the other end of all the magnetization straight lines 86B2a included in the linear magnetization region 86B2 are also aligned.

[0278] Here, an example of a linear magnetization region 86A1 is a set of five magnetized straight lines, namely, magnetization lines 86A1a; an example of a linear magnetization region 86A2 is a set of five magnetized straight lines, namely, magnetization lines 86A2a; an example of a linear magnetization region 86B1 is a set of four magnetized straight lines, namely, magnetization lines 86B1a; and an example of a linear magnetization region 86B2 is a set of four magnetized straight lines, namely, magnetization lines 86B2a; however, the technology disclosed herein is not limited to this. For example, the linear magnetization region 86A1 may be a number of magnetization lines 86A1a that contribute to determining the position of the magnetic head 28 on the magnetic tape MT, the linear magnetization region 86A2 may be a number of magnetization lines 86A2a that contribute to determining the position of the magnetic head 28 on the magnetic tape MT, the linear magnetization region 86B1 may be a number of magnetization lines 86B1a that contribute to determining the position of the magnetic head 28 on the magnetic tape MT, and the linear magnetization region 86B2 may be a number of magnetization lines 86B2a that contribute to determining the position of the magnetic head 28 on the magnetic tape MT.

[0279] Here, the geometric characteristics of the linear magnetized region pair 86A on the magnetic tape MT will be described with reference to FIG.

[0280] 35, the geometric characteristics of the linear magnetization region pair 86A on the magnetic tape MT can be expressed using the virtual linear region pair 62. Here, the symmetry axis SA1 of the virtual linear regions 62A and 62B is tilted by an angle a (e.g., 10 degrees) with respect to the virtual line C1, with the center O1 as the rotation axis, to tilt the entire virtual linear region pair 62 with respect to the virtual line C1. Then, in this state, the positions of one end of all straight lines 62A1 included in the virtual linear region 62A of the virtual linear region pair 62 in the width direction WD are aligned, and the positions of the other end of all straight lines 62A1 included in the virtual linear region 62A are also aligned. Similarly, the positions of one end of all straight lines 62B1 included in the virtual linear region 62B of the virtual linear region pair 62 are aligned, and the positions of the other end of all straight lines 62B1 included in the virtual linear region 62B are also aligned. As a result, the imaginary linear region 62A and the imaginary linear region 62B are shifted in the width direction WD.

[0281] That is, one end of the virtual linear region 62A and one end of the virtual linear region 62B are offset in the width direction WD by a constant interval Int1, and the other end of the virtual linear region 62A and the other end of the virtual linear region 62B are offset in the width direction WD by a constant interval Int2.

[0282] The geometric characteristics of the virtual linear region pair 62 thus obtained (i.e., the geometric characteristics of the virtual servo pattern) correspond to the geometric characteristics of the actual servo pattern 84 A. That is, the geometric characteristics of the linear magnetization region pair 86A on the magnetic tape MT correspond to the geometric characteristics based on the virtual linear region pair 62 when the entire virtual linear region pair 62 is tilted with respect to the virtual line C1 by tilting the symmetry axes SA1 of the virtual linear regions 62A and 62B, which are tilted line-symmetrically with respect to the virtual line C1, with respect to the virtual line C1.

[0283] The virtual linear region 62A corresponds to the linear magnetization region 86A1 of the servo pattern 84A, and the virtual linear region 62B corresponds to the linear magnetization region 86A2 of the servo pattern 84A. Therefore, the servo band SB records a servo pattern 84A consisting of a pair of linear magnetization regions 86A in which one end of the linear magnetization region 86A1 and one end of the linear magnetization region 86A2 are shifted in the width direction WD by a constant interval Int1, and the other end of the linear magnetization region 86A1 and the other end of the linear magnetization region 86A2 are shifted in the width direction WD by a constant interval Int2 (see FIG. 35).

[0284] The pair of linear magnetization regions 86B differs from the pair of linear magnetization regions 86A only in that it has four magnetization lines 86B1a instead of five magnetization lines 86A1a and four magnetization lines 86B2a instead of five magnetization lines 86A2a (see FIG. 35). Thus, a servo pattern 84B is recorded on the servo band SB, which is made up of the pair of linear magnetization regions 86B in which one end of the linear magnetization region 86B1 and one end of the linear magnetization region 86B2 are shifted in the width direction WD by a constant interval Int1 and the other end of the linear magnetization region 86B1 and the other end of the linear magnetization region 86B2 are shifted in the width direction WD by a constant interval Int2 (see FIG. 35).

[0285] As in the above embodiment, in the eighth modified example, as shown in FIG. 35 as an example, the tilting mechanism 49 skews the magnetic head 28 about the rotation axis RA on the magnetic tape MT so that the imaginary line C3 is tilted by an angle γ toward the upstream side in the forward direction relative to the imaginary line C1 (i.e., the angle γ counterclockwise when viewed from the front side of the paper in FIG. 36). That is, the magnetic head 28 is tilted by an angle γ toward the upstream side in the forward direction on the magnetic tape MT. The angle γ is close to the tilt angle of the servo pattern 86. In this state, when the servo read element SR reads the servo pattern 84A along the longitudinal direction LD within the range R where the linear magnetized regions 86A1 and 86A2 overlap in the width direction WD, the variation due to azimuth loss between the servo pattern signals derived from the linear magnetized regions 86A1 and 86A2 is smaller than in the examples shown in FIGS. 12 and 13. Similarly, when the servo pattern 84B (i.e., the linear magnetization region pair 86B) is read by the servo read element SR, the variation due to azimuth loss between the servo pattern signal derived from the linear magnetization region 86B1 and the servo pattern signal derived from the linear magnetization region 86B2 is reduced.

[0286] Next, the operation of the magnetic tape system 10 according to the eighth modification will be described, focusing on the differences from the above embodiment.

[0287] In the magnetic tape drive 14 of this eighth variant, when magnetic processing is performed on the magnetic tape MT by the magnetic element unit 42 (see Figures 3 and 17), the magnetic tape MT is pulled out from the magnetic tape cartridge 12, and the servo pattern 84 in the servo band SB is read by the servo read element SR of the magnetic head 28.

[0288] 34 and 35, the linear magnetized regions 86A1 and 86A2 included in the servo pattern 84A recorded in the servo band SB of the magnetic tape MT are tilted in opposite directions with respect to the imaginary line C1. On the other hand, as shown in Fig. 36, the magnetic head 28 on the magnetic tape MT is also tilted upstream in the forward direction by an angle γ (i.e., an angle γ counterclockwise when viewed from the front side of the paper in Fig. 36). In this state, when the servo pattern 84A is read by the servo read element SR along the longitudinal direction LD within the range R (see Figure 36), the angle formed by the linear magnetization region 86A1 and the servo read element SR becomes close to the angle formed by the linear magnetization region 86A2 and the servo read element SR, so that the variation in the servo pattern signal due to azimuth loss becomes smaller than the variation occurring between the servo pattern signal derived from the linear magnetization region 54A1 included in the conventionally known servo pattern 52A and the servo pattern signal derived from the linear magnetization region 54A2 included in the conventionally known servo pattern 52A.

[0289] As a result, the variation between the servo pattern signals derived from the linear magnetization regions 86A1 and 86A2 is smaller than the variation between the servo pattern signals derived from the linear magnetization regions 54A1 and 54A2 included in the conventionally known servo pattern 52A, and a more reliable servo pattern signal can be obtained than the servo pattern signal obtained from the conventionally known servo pattern 52A. That is, an effect similar to the first effect described in the above embodiment can be obtained. Note that, as shown in FIG. 36, even when the servo pattern 84B is read by the servo read element SR with the magnetic head 28 tilted upstream in the forward direction by an angle γ (i.e., an angle γ counterclockwise when viewed from the front side of the paper in FIG. 36) on the magnetic tape MT, an effect similar to the second effect described in the above embodiment can be obtained.

[0290] Furthermore, in the magnetic tape MT according to the eighth modification, the linear magnetization region 86A1 is a set of five magnetization lines 86A1a, and the linear magnetization region 86A2 is a set of five magnetization lines 86A2a. The linear magnetization region 86B1 is a set of four magnetization lines 86B1a, and the linear magnetization region 86B2 is a set of four magnetization lines 86B2a. Therefore, compared to when each linear magnetization region consists of a single magnetization line, the amount of information obtained from the servo pattern 84 can be increased, resulting in highly accurate servo control. That is, the same effect as the sixth effect described in the above embodiment can be obtained.

[0291] Furthermore, in the magnetic tape MT according to the eighth modification, the geometric characteristics of the linear magnetized region pair 86A on the magnetic tape MT correspond to the geometric characteristics of the virtual linear region pair 62 when the symmetry axis SA1 of the virtual linear region pair 62 is tilted relative to the virtual line C1, thereby tilting the entire virtual linear region pair 62 relative to the virtual line C1. Therefore, compared to when the servo read element SR reads a servo pattern 52A having a conventionally known geometric characteristic, the variation between the servo pattern signal derived from the linear magnetized region 86A1 and the servo pattern signal derived from the linear magnetized region 86A2 can be reduced. As a result, a servo pattern signal with higher reliability can be obtained than the servo pattern signal obtained from the servo pattern 52A having a conventionally known geometric characteristic. That is, the same effect as the seventh effect described in the above embodiment can be obtained.

[0292] The linear magnetization region pair 86B differs from the linear magnetization region pair 86A only in that it has a linear magnetization region 86B1 instead of the linear magnetization region 86A1 and a linear magnetization region 86B2 instead of the linear magnetization region 86A2. Similarly to the linear magnetization region pair 86A, the servo read element SR reads the linear magnetization region pair 86B along the longitudinal direction LD within the range R (see FIG. 36 ). Therefore, compared with the case where the servo read element SR reads the servo pattern 52B having a conventionally known geometric characteristic, the variation between the servo pattern signal derived from the linear magnetization region 86B1 and the servo pattern signal derived from the linear magnetization region 86B2 can be reduced. As a result, a servo pattern signal with higher reliability can be obtained than the servo pattern signal obtained from the servo pattern 52B having a conventionally known geometric characteristic. That is, the same effect as the eighth effect described in the above embodiment can be obtained.

[0293] [Ninth Variation] In the eighth modified example described above, an example was given in which a plurality of V-shaped servo patterns 84 are recorded on the servo band SB along the longitudinal direction LD of the magnetic tape MT, but the technology of the present disclosure is not limited to this. For example, as shown in FIG. 37 , the servo pattern 90 may be a servo pattern magnetized in an M shape. The servo band SB has a plurality of servo patterns 90 recorded along the longitudinal direction LD of the magnetic tape MT. The plurality of servo patterns 72, like the plurality of servo patterns 84, are arranged at regular intervals along the longitudinal direction LD of the magnetic tape MT.

[0294] 37, servo patterns 90A and 90B are shown as an example of a set of servo patterns 90. Each of the servo patterns 90A and 90B is a servo pattern magnetized in an M-shape. The servo patterns 90A and 90B are adjacent to each other along the longitudinal direction LD of the magnetic tape MT. The servo pattern 90A is located on the upstream side in the forward direction, and the servo pattern 90B is located on the downstream side in the forward direction.

[0295] 38, a servo pattern 90 is made up of pairs of linear magnetization regions 92. The pairs of linear magnetization regions 92 are classified into pairs of linear magnetization regions 92A and pairs of linear magnetization regions 92B. A servo pattern 90A is made up of a set of pairs of linear magnetization regions 92A. The sets of pairs of linear magnetization regions 92A are arranged adjacent to each other along the longitudinal direction LD of the magnetic tape MT.

[0296] 38 shows linear magnetization regions 92A1 and 92A2 as an example of the linear magnetization region pair 92A. The linear magnetization region pair 92A is configured similarly to the linear magnetization region pair 86A (see FIG. 34) described in the eighth modified example above, and has similar geometric characteristics to the linear magnetization region pair 86A. That is, the linear magnetization region 92A1 is configured similarly to the linear magnetization region 86A1 (see FIG. 34) described in the eighth modified example above, and has similar geometric characteristics to the linear magnetization region 86A1, and the linear magnetization region 92A2 is configured similarly to the linear magnetization region 86A2 (see FIG. 34) described in the eighth modified example above, and has similar geometric characteristics to the linear magnetization region 86A2.

[0297] In the example shown in Figure 38, linear magnetization region pair 92A is an example of a "linear magnetization region pair" according to the technology of the present disclosure, linear magnetization region 92A1 is an example of a "first linear magnetization region" according to the technology of the present disclosure, and linear magnetization region 92A2 is an example of a "second linear magnetization region" according to the technology of the present disclosure.

[0298] The servo pattern 90B is made up of a pair of linear magnetized regions 92B, which are arranged adjacent to each other along the longitudinal direction LD of the magnetic tape MT.

[0299] 38 shows linear magnetization regions 92B1 and 92B2 as an example of the linear magnetization region pair 92B. The linear magnetization region pair 92B is configured similarly to the linear magnetization region pair 86B (see FIG. 34) described in the eighth modified example above, and has similar geometric characteristics to the linear magnetization region pair 86B. That is, the linear magnetization region 92B1 is configured similarly to the linear magnetization region 86B1 (see FIG. 34) described in the eighth modified example above, and has similar geometric characteristics to the linear magnetization region 86B1, and the linear magnetization region 92B2 is configured similarly to the linear magnetization region 86B2 (see FIG. 34) described in the eighth modified example above, and has similar geometric characteristics to the linear magnetization region 86B2.

[0300] In the example shown in Figure 38, linear magnetization region pair 92B is an example of a "linear magnetization region pair" according to the technology of the present disclosure, linear magnetization region 92B1 is an example of a "first linear magnetization region" according to the technology of the present disclosure, and linear magnetization region 92B2 is an example of a "second linear magnetization region" according to the technology of the present disclosure.

[0301] [Tenth Modification] In the example shown in Figure 37, an example has been described in which a plurality of M-shaped servo patterns 90 are recorded on the servo band SB along the longitudinal direction LD of the magnetic tape MT, but the technology of the present disclosure is not limited to this. For example, as shown in Figure 39, the servo pattern 96 may be a servo pattern magnetized in an N-shape. A plurality of servo patterns 96 are recorded on the servo band SB along the longitudinal direction LD of the magnetic tape MT. The plurality of servo patterns 96 are arranged at regular intervals along the longitudinal direction LD of the magnetic tape MT, similar to the plurality of servo patterns 90 (see Figure 37).

[0302] 39, servo patterns 96A and 96B are shown as an example of a set of servo patterns 96. Each of the servo patterns 96A and 96B is a servo pattern magnetized in an N-shape. The servo patterns 96A and 96B are adjacent to each other along the longitudinal direction LD of the magnetic tape MT. The servo pattern 96A is located on the upstream side in the forward direction, and the servo pattern 96B is located on the downstream side in the forward direction.

[0303] 40, as an example, a servo pattern 96 is made up of linear magnetization region groups 98. The linear magnetization region groups 98 are classified into linear magnetization region groups 98A and linear magnetization region groups 98B.

[0304] The servo pattern 96A is made up of a linear magnetization region group 98A. The linear magnetization region group 98A is made up of linear magnetization regions 98A1, 98A2, and 98A3. The linear magnetization regions 98A1, 98A2, and 98A3 are arranged adjacent to each other along the longitudinal direction LD of the magnetic tape MT. The linear magnetization regions 98A1, 98A2, and 98A3 are arranged in this order from the upstream side in the forward direction.

[0305] The linear magnetization regions 98A1 and 98A2 are configured similarly to the linear magnetization region pair 92A shown in Fig. 38 and have similar geometric characteristics. That is, the linear magnetization region 98A1 is configured similarly to the linear magnetization region 92A1 shown in Fig. 38 and has similar geometric characteristics, and the linear magnetization region 98A2 is configured similarly to the linear magnetization region 92A2 shown in Fig. 38 and has similar geometric characteristics. Furthermore, the linear magnetization region 98A3 is configured similarly to the linear magnetization region 92A1 and has similar geometric characteristics.

[0306] 40, linear magnetization regions 98A1 and 98A2 are an example of a "linear magnetization region pair" according to the technology of the present disclosure. In this case, linear magnetization region 98A1 is an example of a "first linear magnetization region" according to the technology of the present disclosure, and linear magnetization region 98A2 is an example of a "second linear magnetization region" according to the technology of the present disclosure. Linear magnetization regions 98A2 and 98A3 are also an example of a "linear magnetization region pair" according to the technology of the present disclosure. In this case, linear magnetization region 98A3 is an example of a "first linear magnetization region" according to the technology of the present disclosure, and linear magnetization region 98A2 is an example of a "second linear magnetization region" according to the technology of the present disclosure.

[0307] The servo pattern 96B is made up of a linear magnetization region group 98B. The linear magnetization region group 98B is made up of linear magnetization regions 98B1, 98B2, and 98B3. The linear magnetization regions 98B1, 98B2, and 98B3 are arranged adjacent to each other along the longitudinal direction LD of the magnetic tape MT. The linear magnetization regions 98B1, 98B2, and 98B3 are arranged in this order from the upstream side in the forward direction.

[0308] The linear magnetization regions 98B1 and 98B2 are configured similarly to the linear magnetization region pair 92B shown in Fig. 38 and have similar geometric characteristics. That is, the linear magnetization region 98B1 is configured similarly to the linear magnetization region 92B1 shown in Fig. 38 and has similar geometric characteristics, and the linear magnetization region 98B2 is configured similarly to the linear magnetization region 92B2 shown in Fig. 38 and has similar geometric characteristics. Furthermore, the linear magnetization region 98B3 is configured similarly to the linear magnetization region 92B1 and has similar geometric characteristics.

[0309] 40, linear magnetization regions 98B1 and 98B2 are an example of a "linear magnetization region pair" according to the technology of the present disclosure. In this case, linear magnetization region 98B1 is an example of a "first linear magnetization region" according to the technology of the present disclosure, and linear magnetization region 98B2 is an example of a "second linear magnetization region" according to the technology of the present disclosure. Linear magnetization regions 98B2 and 98B3 are also an example of a "linear magnetization region pair" according to the technology of the present disclosure. In this case, linear magnetization region 98B3 is an example of a "first linear magnetization region" according to the technology of the present disclosure, and linear magnetization region 98B2 is an example of a "second linear magnetization region" according to the technology of the present disclosure.

[0310] [Eleventh Modification] In the above embodiment, an example was described in which the servo format information SF is stored in the cartridge memory 24, but the technology of the present disclosure is not limited to this. In the present eleventh modification, the servo format information SF is stored on a magnetic tape MT. The magnetic tape MT is an example of a "storage medium" according to the technology of the present disclosure.

[0311] As an example, as shown in Figure 41, the servo format information SF is stored in a BOT area MT1 provided at the beginning of the magnetic tape MT. The control device 30 acquires a data band signal (i.e., a signal indicating the servo format information SF) resulting from reading the data band DB in the BOT area MT1 by the data read / write element DRW (see Figure 6). The control device 30 performs servo control, skew angle control, and / or tension control. The servo format information SF may be recorded in an EOT area MT2 provided at the end of the magnetic tape MT, or the servo format information SF may be recorded in both the BOT area MT1 and the EOT area MT2. A configuration may also be adopted in which part of the servo format information SF is recorded on the magnetic tape MT, and the rest of the servo format information SF is stored in the cartridge memory 24.

[0312] As described above, according to the eleventh modification, the servo format information SF is recorded in the BOT area MT1 of the magnetic tape MT. Therefore, according to this configuration, the servo format information SF can be stored more easily than when a separate storage medium is provided for the magnetic tape cartridge 12.

[0313] [12th Modification] In the above embodiment, an example has been described in which the linear magnetization region 60A1 in the servo pattern 58 has a steeper inclination angle with respect to the virtual line C1 than the linear magnetization region 60A2, but the technology of the present disclosure is not limited to this. For example, as shown in FIG. 42 , the linear magnetization region 600A2 may have a steeper inclination angle with respect to the virtual line C1 than the linear magnetization region 600A1. A plurality of servo patterns 580 are recorded on the servo band SB along the longitudinal direction LD of the magnetic tape MT. Like the plurality of servo patterns 58, the plurality of servo patterns 580 are arranged at regular intervals along the longitudinal direction LD of the magnetic tape MT.

[0314] The servo pattern 580 is made up of a pair of linear magnetization regions 600. In the present twelfth modification, the pair of linear magnetization regions 600 is an example of a "pair of linear magnetization regions" according to the technique of the present disclosure.

[0315] The linear magnetization region pair 600 is classified into a linear magnetization region pair 600A and a linear magnetization region pair 600B. That is, the linear magnetization region pair 600 differs from the linear magnetization region pair 60 in that it has a linear magnetization region 600A instead of the linear magnetization region pair 60A, and a linear magnetization region 600B instead of the linear magnetization region 60B.

[0316] The servo pattern 580A is composed of a pair of linear magnetization regions 600A. The pair of linear magnetization regions 600A differs from the pair of linear magnetization regions 60A in that it has a linear magnetization region 600A1 instead of the linear magnetization region 60A1, and a linear magnetization region 600A2 instead of the linear magnetization region 60A2. Each of the linear magnetization regions 600A1 and 600A2 is a linearly magnetized region. In the present twelfth modification, the linear magnetization region 600A1 is an example of a "second linear magnetization region" according to the technology of the present disclosure, and the linear magnetization region 600A2 is an example of a "first linear magnetization region" according to the technology of the present disclosure.

[0317] The linear magnetization regions 600A1 and 600A2 are inclined in opposite directions with respect to the virtual line C1. The linear magnetization regions 600A1 and 600A2 are non-parallel to each other and are inclined at different angles with respect to the virtual line C1. The linear magnetization region 600A2 has a steeper inclination angle with respect to the virtual line C1 than the linear magnetization region 600A1. Here, "steep" means, for example, that the angle of the linear magnetization region 600A2 with respect to the virtual line C1 is smaller than the angle of the linear magnetization region 600A2 with respect to the virtual line C1. Furthermore, the total length of the linear magnetization region 600A2 is shorter than the total length of the linear magnetization region 600A2.

[0318] The linear magnetization region 600A1 differs from the linear magnetization region 60A1 in that it has a plurality of magnetization lines 600A1a instead of the plurality of magnetization lines 60A1a. The linear magnetization region 600A2 differs from the linear magnetization region 60A2 in that it has a plurality of magnetization lines 600A2a instead of the plurality of magnetization lines 60A2a.

[0319] The linear magnetization region 600A1 includes a plurality of magnetization lines 600A1a, and the linear magnetization region 600A2 includes a plurality of magnetization lines 600A2a. The number of magnetization lines 600A1a included in the linear magnetization region 600A1 is the same as the number of magnetization lines 600A2a included in the linear magnetization region 600A2.

[0320] The linear magnetization region 600A1 is a linear magnetization region corresponding to the first axisymmetric region. The first axisymmetric region refers to a region in which the linear magnetization region 60A2 (see FIG. 9) described in the first embodiment is formed axisymmetrically with respect to the virtual line C1. In other words, the linear magnetization region 600A1 can also be said to be a linear magnetization region formed with the geometric characteristics of a mirror image of the linear magnetization region 60A2 (see FIG. 9) (i.e., the geometric characteristics obtained by performing a mirror image of the linear magnetization region 60A2 (see FIG. 9) with the virtual line C1 as the axis of axisymmetrical symmetry).

[0321] The linear magnetization region 600A2 is a linear magnetization region corresponding to the second axisymmetric region. The second axisymmetric region refers to a region in which the linear magnetization region 60A1 (see FIG. 9) described in the first embodiment is formed axisymmetrically with respect to the virtual line C1. In other words, the linear magnetization region 600A2 can also be said to be a linear magnetization region formed with the geometric characteristics of a mirror image of the linear magnetization region 60A1 (see FIG. 9) (i.e., the geometric characteristics obtained by performing a mirror image of the linear magnetization region 60A1 (see FIG. 9) with the virtual line C1 as the axis of axisymmetrical symmetry).

[0322] In other words, in the example shown in Figure 10, the symmetry axis SA1 of the virtual linear regions 62A and 62B is tilted clockwise by an angle a when viewed from the front side of the paper in Figure 10, with the center O1 as the rotation axis, relative to the virtual straight line C1, thereby aligning the positions of both ends of the virtual linear region 62A and the positions of both ends of the virtual linear region 62B, and the geometric characteristics of the virtual linear region pair 62 obtained thereby correspond to the geometric characteristics of the servo pattern 580A.

[0323] The servo pattern 580B is made up of a pair of linear magnetization regions 600B. The pair of linear magnetization regions 600B differs from the pair of linear magnetization regions 60B in that it has a linear magnetization region 600B1 instead of the linear magnetization region 60B1, and a linear magnetization region 600B2 instead of the linear magnetization region 60B2. Each of the linear magnetization regions 600B1 and 600B2 is a linearly magnetized region. In the present twelfth modification, the linear magnetization region 600B1 is an example of a "second linear magnetization region" according to the technology of the present disclosure, and the linear magnetization region 600B2 is an example of a "first linear magnetization region" according to the technology of the present disclosure.

[0324] The linear magnetization regions 600B1 and 600B2 are tilted in opposite directions with respect to the virtual line C2. The linear magnetization regions 600B1 and 600B2 are non-parallel to each other and tilt at different angles with respect to the virtual line C2. The linear magnetization region 600B2 has a steeper tilt angle with respect to the virtual line C2 than the linear magnetization region 600B1. Here, "steep" means, for example, that the angle of the linear magnetization region 600B2 with respect to the virtual line C2 is smaller than the angle of the linear magnetization region 600B2 with respect to the virtual line C2.

[0325] The linear magnetization region 600B1 includes a plurality of magnetization lines 600B1a, and the linear magnetization region 600B2 includes a plurality of magnetization lines 600B2a. The number of magnetization lines 600B1a included in the linear magnetization region 600B1 is the same as the number of magnetization lines 600B2a included in the linear magnetization region 600B2.

[0326] The total number of magnetization lines 600B1a and 600B2a included in the servo pattern 580B is different from the total number of magnetization lines 600A1a and 600A2a included in the servo pattern 580A. In the example shown in Fig. 42, the total number of magnetization lines 600A1a and 600A2a included in the servo pattern 580A is 10, while the total number of magnetization lines 600B1a and 600B2a included in the servo pattern 580B is 8.

[0327] The linear magnetization region 600B1 is a set of four magnetized straight lines, ie, magnetization lines 600B1a, and the linear magnetization region 600B2 is a set of four magnetized straight lines, ie, magnetization lines 600B2a. Within the servo band SB, the positions of both ends of the linear magnetization region 600B1 (i.e., the positions of both ends of each of the four magnetization lines 600B1a) and the positions of both ends of the linear magnetization region 600B2 (i.e., the positions of both ends of each of the four magnetization lines 600B2a) are aligned in the width direction WD.

[0328] In this way, the geometric characteristics of servo pattern 580A correspond to the geometric characteristics of the mirror image of linear magnetization region 60A2 (see Figure 9) and the geometric characteristics of the mirror image of linear magnetization region 60A2 (see Figure 9) (i.e., the geometric characteristics of the mirror image of servo pattern 58A (see Figure 9) shown in Figure 9), and the geometric characteristics of servo pattern 580B correspond to the geometric characteristics of the mirror image of linear magnetization region 60B2 (see Figure 9) and the geometric characteristics of the mirror image of linear magnetization region 60B2 (see Figure 9) (i.e., the geometric characteristics of the mirror image of servo pattern 58B (see Figure 9) shown in Figure 9). However, this is merely one example, and instead of servo pattern 580, a servo pattern formed with the geometric characteristics of the mirror image of servo pattern 72 shown in Figure 30, the geometric characteristics of the mirror image of servo pattern 78 shown in Figure 32, the geometric characteristics of the mirror image of servo pattern 84 shown in Figure 34, the geometric characteristics of the mirror image of servo pattern 90 shown in Figure 37, or the geometric characteristics of the mirror image of servo pattern 96 shown in Figure 39 may be applied. [Example]

[0329] The PES fluctuation range of the magnetic tape MT was evaluated using the magnetic tape system 10 according to this embodiment. The evaluation results are shown in Table 1.

[0330] [Table 1]

[0331] As an example, as shown in Table 1, in Example 1, information indicating the skew angle of the servo pattern recording head WH (i.e., the tilt angle α of the servo pattern 58 when the servo pattern 58 was recorded) was stored in the cartridge memory 24 as the servo format information SF. Then, based on the information indicating the skew angle of the servo pattern recording head WH, the magnetic head skew angle was adjusted to read and write data from and to the magnetic tape MT. As a result, the PES fluctuation range was 16 nm. In Example 2, the tilt angle α of the servo pattern 58 estimated by magnetic development was stored in the cartridge memory 24 as the servo format information SF. Then, based on the tilt angle α of the servo pattern 58 estimated by magnetic development, the magnetic head skew angle was adjusted to read and write data from and to the magnetic tape MT. As a result, the PES fluctuation range was 13 nm.

[0332] In Example 3, the servo format information SF used in Examples 1 and 2 was stored in the cartridge memory 24 as the servo format information SF. Then, based on the servo format information SF used in Examples 1 and 2, the magnetic head skew angle was adjusted and data was read and written from the magnetic tape MT. As a result, the PES fluctuation range was 12 nm. In Example 4, in addition to the servo format information SF used in Examples 1 and 2, an ideal waveform signal 67 corresponding to the tilt angle α of the servo pattern 58 was stored in the cartridge memory 24 as the servo format information SF. Then, based on the servo format information SF used in Examples 1 and 2 and the ideal waveform signal 67 corresponding to the tilt angle α of the servo pattern 58, the magnetic head skew angle was adjusted and data was read and written from the magnetic tape MT. As a result, the PES fluctuation range was 10 nm.

[0333] In Example 5, magnetic tape width change information SF2 was stored as the servo format information SF in addition to the servo format information SF used in Examples 1 to 4. Then, based on the servo format information SF and the magnetic tape width change information SF2 used in Examples 1 to 4, the magnetic head skew angle was adjusted, and reading and writing were performed on the magnetic tape MT. As a result, the PES fluctuation range was 8 nm. In Example 6, width adjustment information SF4 was stored in the cartridge memory 24 as the servo format information SF in addition to the servo format information SF used in Examples 1 to 5. Then, based on the servo format information SF used in Examples 1 to 5, the magnetic head skew angle was adjusted, and further based on the width adjustment information SF4, the tape width W was adjusted, and reading and writing were performed on the magnetic tape MT. As a result, the PES fluctuation range was 7 nm. The PES fluctuation ranges in Examples 1 to 6 were all 18 nm or less, which is within the preferable PES fluctuation range.

[0334] In Comparative Example 1, reading and writing were performed on the magnetic tape MT without using servo pattern tilt information SF1 as the servo format information SF. As a result, the PES fluctuation range was 23 nm. In Comparative Example 2, magnetic tape width change information SF2 and width adjustment information SF4 were stored in the cartridge memory 24. Then, based on the magnetic tape width change information SF2 and width adjustment information SF4, the tape width W was adjusted and reading and writing were performed on the magnetic tape MT. As a result, the PES fluctuation range was 20 nm. The PES fluctuation ranges in Comparative Example 1 and Comparative Example 2 both exceeded the preferred PES fluctuation range (i.e., 18 nm or less).

[0335] [Other variations] In the above embodiment, the magnetic tape system 10 is exemplified as one in which the magnetic tape cartridge 12 is freely insertable into and removable from the magnetic tape drive 14, but the technology of the present disclosure is not limited to this. For example, the technology of the present disclosure can also be applied to a magnetic tape system in which at least one magnetic tape cartridge 12 is pre-loaded into the magnetic tape drive 14 (i.e., a magnetic tape system in which at least one magnetic tape cartridge 12 and the magnetic tape drive 14 are pre-integrated).

[0336] In the above embodiment, a single magnetic head 28 is exemplified, but the technology of the present disclosure is not limited to this. For example, multiple magnetic heads 28 may be arranged on the magnetic tape MT. For example, a read magnetic head 28 and at least one write magnetic head 28 may be arranged on the magnetic tape MT. The read magnetic head 28 may be used to verify data recorded on the data band DB by the write magnetic head 28. Furthermore, one magnetic head equipped with a read magnetic element unit 42 and at least one write magnetic element unit 42 may be arranged on the magnetic tape MT.

[0337] In the above embodiment, an example was described in which the servo format information SF is stored in the cartridge memory 24 during the manufacturing stage of the magnetic tape cartridge 12, but the technology of the present disclosure is not limited to this. For example, the servo format information SF may be recorded after the magnetic tape cartridge 12 is shipped, or may be recorded when the magnetic tape cartridge 12 is in use (i.e., when data is written to and read from the magnetic tape MT). In addition, the servo format information SF stored in the cartridge memory 24 may be updated.

[0338] In the above embodiment, the PES is calculated using the above formula (1), but the technology of the present disclosure is not limited to this. For example, the PES may be calculated using the following formula (2).

[0339]

number

[0340] Here, in the above formula (2), ΣAi means, for example, the sum of the second distances obtained from all pairs of magnetized regions in one servo pattern 58A. Also, ΣBi means, for example, the sum of the first distances obtained from all pairs of magnetized regions in one servo pattern 58A. A pair of magnetized regions refers to a combination of a magnetization line 60A1a and a magnetization line 60B1a that are in a corresponding positional relationship.

[0341] In the above embodiment, the ideal waveform signal 67 is described as an ideal waveform of a servo pattern signal obtained by reading the servo read element SR provided in the magnetic head 28, but the technology of the present disclosure is not limited to this. For example, the ideal waveform signal may be an ideal waveform signal that indicates the ideal waveform of a servo pattern signal obtained by reading the verify head VH.

[0342] Furthermore, in the above embodiment, an example in which the control device 30 (see FIG. 3) is realized by an ASIC has been described, but the technology of the present disclosure is not limited to this, and the control device 30 may be realized by a software configuration. Furthermore, only the position detection unit 30B included in the control device 30 may be realized by a software configuration. When the position detection unit 30B is realized by a software configuration, for example, as shown in FIG. 43, the position detection unit 30B includes a computer 100. The computer 100 has a processor 100A (e.g., a single CPU or multiple CPUs), an NVM 100B, and a RAM 100C. The processor 100A, the NVM 100B, and the RAM 100C are connected to a bus 100D. A portable storage medium 102 (e.g., an SSD or a USB memory), which is a computer-readable non-transitory storage medium, stores a servo pattern detection program PG.

[0343] The servo pattern detection program PG stored in the storage medium 102 is installed in the computer 100. The CPU 100A executes the servo pattern detection process (see FIG. 19) in accordance with the servo pattern detection program PG.

[0344] The servo pattern detection program PG may also be stored in a storage device such as another computer or server device connected to the computer 100 via a communication network (not shown), and the servo pattern detection program PG may be downloaded in response to a request from the position detection unit 30B and installed in the computer 100. The servo pattern detection program PG is an example of a "program" according to the technology of the present disclosure, and the computer 100 is an example of a "computer" according to the technology of the present disclosure.

[0345] 43 illustrates a computer 100, the technology of the present disclosure is not limited to this, and a device including an ASIC, an FPGA, and / or a PLC may be applied instead of the computer 100. Also, a combination of a hardware configuration and a software configuration may be used instead of the computer 100.

[0346] The hardware resources that execute the processing of the control device 30 (see FIG. 3) and / or the servo writer controller SW5 (see FIG. 18) can be various processors, as listed below. Examples of processors include a CPU, which is a general-purpose processor that functions as a hardware resource that executes processing by executing software, i.e., a program. Examples of processors also include dedicated electrical circuits, such as FPGAs, PLCs, or the exemplary ASICs, which are processors with a circuit configuration specifically designed to execute specific processing. Each processor has built-in or connected memory, and executes processing by using the memory.

[0347] The hardware resources that execute the processing of the control device 30 and / or the servo writer controller SW5 may be configured with one of these various processors, or may be configured with a combination of two or more processors of the same or different types (for example, a combination of multiple FPGAs, or a combination of a CPU and an FPGA). Also, the hardware resources that execute the processing of the control device 30 and / or the servo writer controller SW5 may be a single processor.

[0348] As an example of a single processor configuration, first, one processor is configured by combining one or more CPUs and software, and this processor functions as a hardware resource that executes processing. Second, there is a configuration in which a processor is used that realizes the functions of the entire system, including multiple hardware resources that execute processing, on a single IC chip, as typified by SoCs, etc. In this way, the processing of the control device 30 and / or the servo writer controller SW5 is realized using one or more of the above-mentioned various processors as hardware resources.

[0349] Furthermore, the hardware structure of these various processors can be, more specifically, an electric circuit that combines circuit elements such as semiconductor devices. The processing of the control device 30 and / or servo writer controller SW5 described above is merely an example. Therefore, it goes without saying that unnecessary steps may be deleted, new steps may be added, or the processing order may be rearranged, without departing from the spirit of the invention.

[0350] The above-described description and illustrations are a detailed explanation of the parts related to the technology of the present disclosure and are merely an example of the technology of the present disclosure. For example, the above description of the configuration, functions, actions, and effects is an explanation of an example of the configuration, functions, actions, and effects of the parts related to the technology of the present disclosure. Therefore, it goes without saying that unnecessary parts may be deleted, new elements may be added, or replacements may be made to the above-described description and illustrations within the scope of the gist of the technology of the present disclosure. Furthermore, to avoid confusion and facilitate understanding of the parts related to the technology of the present disclosure, the above-described description and illustrations omit explanations of common technical knowledge that do not require particular explanation to enable the implementation of the technology of the present disclosure.

[0351] In this specification, "A and / or B" is synonymous with "at least one of A and B." In other words, "A and / or B" means that it may be only A, only B, or a combination of A and B. Furthermore, in this specification, the same concept as "A and / or B" is also applied when three or more things are expressed connected by "and / or."

[0352] All publications, patent applications, and technical standards mentioned in this specification are herein incorporated by reference to the same extent as if each individual publication, patent application, or technical standard was specifically and individually indicated to be incorporated by reference. [Explanation of symbols]

[0353] 10 Magnetic Tape Systems 12 Magnetic tape cartridge 14 Magnetic Tape Drive 16 cases 16A Right Wall 16B opening 18 Upper case 20 Lower case 22, SW1 Delivery reel 22A reel hub 22B1 Upper flange 22B2 bottom flange 24 Cartridge Memory 24B,33 Back side 26 Transport equipment 28 Magnetic Head 29A magnetic layer 29B base film 29C Backcoat layer 30, SW5 control device 30A control unit 30B Position detection unit 30B1 First position detection unit 30B2 Second position detection unit 30C PES calculation part 30D Angle detection unit 30D1 First angle detection unit 30D2 Second angle detection unit 31 Surface 32 Storage 34 UI devices 35 Communication Interface 36 Sending motor 37 External device 38,SW2 Take-up reel 40M Winding motor 42 Magnetic element unit 44 Holder 46 Contactless reading and writing device 48 Moving mechanism 48A Moving Actuator 49 Tilt mechanism 49A Tilt Actuator 52, 52A, 52B, 58, 58A, 58B, 72, 72A, 72B, 78, 78A, 78B, 84, 84A, 84B, 90, 90A, 90B, 580, 580A, 580B Servo Pattern 54, 54A, 54B, 60, 60A, 60B, 74, 74A, 74B, 86, 86A, 86B, 92, 92A, 92B, 600, 600A, 600B Linear magnetization region pair 54A1,54A2,54B1,54B2,60A1,60A2,60B1,60B2,74A1,74A2,74B1,74B2,80A1,80A2 ,80A3,86A1,86A2,86B1,86B2,92A1,92A2,92B1,92B2,600A1,600A2,600B1,600B2 linear magnetization region 54A1a,54A2a,54B1a,54B2a,60A1a,60A2a,60B1a,60B2a,86A1a,86A2a,86B1a,86B2a,600A1a,600A2a,600B1a,600B2a Magnetization straight line 62 Virtual Linear Area Pair 62A, 62B Virtual linear area 62A1,62B1 straight line 66,67 Ideal waveform signal 68 Virtual Linear Pairs 68A, 68B Virtual linear area 80,80A,80B Linear magnetization region group A, B, C arrows α,β,γ,θa,θb,θ Ai ,θ Bi angle VH Verify Head C1, C2, C3, C4 Virtual lines DB, DB1, DB2 data band DRW Data read / write element GR guide roller Int1,Int2 interval L0 line segment LD Longitudinal direction MF magnetic field MT,MT0 magnetic tape O1 center RA rotation axis S Servo band signal S1 First servo band signal S2 Second servo band signal SP Servo pattern signal SP1 First servo pattern signal SP2 Second servo pattern signal SA1, SA2 symmetry axis SB, SB1, SB2, SB3 servo band SR, SR1, SR2 servo read element SW Servo Writer SW3 drive unit SW4 Pulse signal generator SW4A 1st pulse signal generator SW4B Second Pulse Signal Generator SW4C 3rd pulse signal generator SW5 Servo writer controller SW6 Guide SW7 transport path SF Servo Format Information SF1 Servo pattern tilt information SF2 Magnetic tape width change information SF3 Servo pattern geometric characteristic information SF4 width adjustment information SF4a tension information SF5 skew angle information TF tension influence factor information TF1,DF1 magnetic tape width information TF2, DF2 magnetic tape characteristics information TF3,DF3 usage history information TF4,DF4 temperature information TF5,DF5 humidity information DF angle influence factor information W Magnetic tape width WD Width direction WH servo pattern recording head

Claims

1. a magnetic tape on which a plurality of servo patterns are recorded along the longitudinal direction; a storage medium; The storage medium stores servo format information including servo pattern tilt information, which is information regarding the tilt of the servo pattern with respect to a first virtual straight line. Magnetic tape cartridge.

2. the first virtual straight line is a straight line along the width direction of the magnetic tape, the servo pattern is at least one pair of linear magnetized regions, the pair of linear magnetization regions is a linearly magnetized first linear magnetization region and a linearly magnetized second linear magnetization region, the first linear magnetization region and the second linear magnetization region are inclined in opposite directions with respect to the first virtual line, the first linear magnetization region has a steeper inclination angle with respect to the first virtual line than the second linear magnetization region; The servo pattern tilt information includes information about the tilt angle of the first linear magnetization region with respect to the first virtual line, and information about the tilt angle of the second linear magnetization region with respect to the first virtual line.

2. The magnetic tape cartridge of claim 1.

3. Both ends of the first linear magnetized region and both ends of the second linear magnetized region are aligned in the width direction of the magnetic tape.

3. The magnetic tape cartridge according to claim 2.

4. The total length of the first linear magnetization region is shorter than the total length of the second linear magnetization region.

4. The magnetic tape cartridge according to claim 3.

5. the first linear magnetization region is a set of a plurality of first magnetization straight lines, The second linear magnetization region is a set of a plurality of second magnetization lines.

5. The magnetic tape cartridge according to claim 2.

6. The geometric characteristics of the pair of linear magnetized regions on the magnetic tape correspond to the geometric characteristics based on the pair of virtual linear regions when the entire pair of virtual linear regions is tilted with respect to the first virtual line by tilting the symmetry axes of the pair of virtual linear regions that are tilted line-symmetrically with respect to the first virtual line.

6. The magnetic tape cartridge according to claim 2.

7. The geometric characteristic of the pair of linear magnetized regions on the magnetic tape corresponds to a geometric characteristic in which the positions of both ends of one of the pair of virtual linear regions and the positions of both ends of the other virtual linear region are aligned in the width direction when the symmetry axes of the pair of virtual linear regions inclined in line symmetry with respect to the first virtual line are inclined with respect to the first virtual line.

10. The magnetic tape cartridge according to claim 3, claim 4, or claim 5 dependent on claim 3 or claim 4.

8. The servo format information includes an ideal waveform signal that indicates an ideal waveform of a servo pattern signal that is a result of the servo pattern being read by a servo read element.

8. The magnetic tape cartridge according to claim 1.

9. The ideal waveform is a waveform determined according to the orientation of the servo read element on the magnetic tape.

9. The magnetic tape cartridge according to claim 8.

10. The ideal waveform is a waveform determined according to the geometric characteristics of the servo pattern and the orientation of the servo read element on the magnetic tape.

10. The magnetic tape cartridge according to claim 9.

11. The servo read element is mounted on a magnetic head, The ideal waveform is a waveform determined according to the orientation of the magnetic head on the magnetic tape.

9. The magnetic tape cartridge according to claim 8.

12. The ideal waveform is a waveform determined according to the geometric characteristics of the servo pattern and the orientation of the magnetic head on the magnetic tape.

12. The magnetic tape cartridge of claim 11.

13. The servo format information includes information about the width of the magnetic tape and / or information about the geometric characteristics of the servo pattern.

13. The magnetic tape cartridge according to claim 1.

14. The servo format information includes width adjustment information for adjusting the width of the magnetic tape.

14. The magnetic tape cartridge according to claim 1.

15. The width adjustment information includes information about the tension in the overall length direction of the magnetic tape.

15. The magnetic tape cartridge of claim 14.

16. The information about the tension is determined according to the width of the magnetic tape, the characteristics of the magnetic tape itself, the usage history of the magnetic tape, the temperature applied to the magnetic tape, and / or the humidity applied to the magnetic tape.

16. The magnetic tape cartridge of claim 15.

17. The servo format information includes information about a skew angle, which is an angle at which a magnetic head equipped with a servo read element for reading the servo pattern is skewed on the magnetic tape.

17. The magnetic tape cartridge according to claim 1.

18. The information regarding the skew angle is determined according to the width of the magnetic tape, the characteristics of the magnetic tape itself, the usage history of the magnetic tape, the temperature applied to the magnetic tape, and / or the humidity applied to the magnetic tape.

18. The magnetic tape cartridge of claim 17.

19. The magnetic tape is housed in a cartridge, The cartridge is provided with a non-contact type storage medium as the storage medium.

19. The magnetic tape cartridge according to any one of claims 1 to 18.

20. The storage medium is the magnetic tape.

19. The magnetic tape cartridge according to any one of claims 1 to 18.

21. a processor; The processor: acquiring the servo format information stored in the storage medium provided in the magnetic tape cartridge according to any one of claims 1 to 20; Executes processing according to the acquired servo format information. Magnetic tape drive.

22. Acquiring servo format information stored in a storage medium provided in a magnetic tape cartridge having a magnetic tape on which a plurality of servo patterns are recorded along a longitudinal direction, the servo format information including servo pattern tilt information which is information regarding the tilt of the servo patterns with respect to a first virtual straight line; and Executing a process according to the acquired servo format information. A servo pattern detection method comprising:

23. On the computer, Acquiring servo format information stored in a storage medium provided in a magnetic tape cartridge having a magnetic tape on which a plurality of servo patterns are recorded along a longitudinal direction, the servo format information including servo pattern tilt information which is information regarding the tilt of the servo patterns with respect to a first virtual straight line; and Executing a process according to the acquired servo format information A program for executing a process including:

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