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

Abstract

To provide a servo pattern recording device, a magnetic tape, a magnetic tape cartridge, a magnetic tape drive, a magnetic tape system, a detection device, an inspection device, a servo pattern recording method, a method for manufacturing the magnetic tape, a detection method, and an inspection method with which a highly reliable servo signal can be obtained.SOLUTION: A plurality of gap patterns are formed on a surface of a substrate along a direction corresponding to a width direction of a magnetic tape. A first straight line area is inclined at a steeper angle with respect to a first virtual straight line than a second straight line area. Positions of both ends of the first straight line area and positions of both ends of the second straight line area are aligned in a direction corresponding to the width direction of the magnetic tape. Positions of the plurality of gap patterns are aligned in a longitudinal direction of the magnetic tape. The plurality of gap patterns are supplied with pulse signals with a delay by a prescribed time from one side to the other side of a direction in which the plurality of gap patterns are arranged.SELECTED DRAWING: Figure 18

Description

Technical Field

[0001] The technology of the present disclosure relates to a servo pattern recording apparatus, a magnetic tape, a magnetic tape cartridge, a magnetic tape drive, a magnetic tape system, a detection apparatus, an inspection apparatus, a servo pattern recording method, a method for manufacturing a magnetic tape, a detection method, and an inspection method. Background Art

[0002] Patent Document 1 addresses the problem that in a magnetic tape device, reading and / or writing errors occur when the tape does not pass through the head at an appropriate tension and / or skew angle. To solve this problem, the system described in Patent Document 1 comprises: a head having at least one array of a reader and a writer; a drive mechanism for passing a magnetic recording tape over the head; a skew induction mechanism coupled to the head, which adjusts the skew angle of the longitudinal axis of the array relative to a direction perpendicular to the direction in which the tape travels over the head; and a controller in communication with the head. The system described in Patent Document 1 also determines a tape dimensional stability state of the tape, adjusts the skew angle in a direction away from the normal relative to the moving direction of the tape, and reduces the tension of the tape across the head when the tape dimensional stability state is in a contracted state.

[0003] Patent Document 2 discloses a method in which reading is performed on data tracks of a magnetic tape with lateral strain by selectively using reading elements offset in the longitudinal direction. The reading elements are part of a tape head having an azimuth angle relative to the tape, creating a lateral offset between the reading elements. This lateral offset is used to minimize the influence of lateral tape strain.

[0004] Patent Document 3 discloses a head device comprising: a head unit having a plurality of magnetic elements arranged at equal intervals on a first straight line, each performing at least one of reproducing data recorded on a plurality of data tracks provided on a magnetic tape and recording data to each of the data tracks; a moving mechanism for moving the head unit; and a control unit that performs tracking control to on-track each of the magnetic elements to each of the data tracks by moving the head unit relative to the moving mechanism. In the head device described in Patent Document 3, the moving mechanism is configured to be capable of rotational drive to rotate the head unit in a direction that increases or decreases the angle between a second straight line and a first straight line along the width of the magnetic tape, and the control unit, when performing tracking control, rotates the head unit relative to the moving mechanism by an amount of increase or decrease in angle corresponding to the change in the spacing between each data track to on-track each of the magnetic elements to each data track.

[0005] Patent Document 4 describes a method for forming a servo track configuration, comprising the steps of forming at least one servo track having a width, and recording a servo pattern iteratively within the servo track, wherein the recording step includes the step of iteratively recording first and second reference pattern lines and a track pattern line simultaneously within the servo track. Each of the first and second reference pattern lines has the same predetermined shape and extends across the width of the servo track, and further, the track pattern line has a predetermined shape different from the predetermined shapes of the first and second reference pattern lines and extends across the width of the servo track.

[0006] Patent Document 5 describes a magnetic tape reading device comprising: an acquisition unit that acquires information regarding the linearity of a servo pattern recorded on the servo band of the magnetic tape having a magnetic tape cartridge; a reading element unit in which at least two reading elements are arranged in close proximity, each reading data from a specific track area including a track to be read in a linear scan manner among the track areas included in the magnetic tape; a servo reading element that reads the servo pattern; a control unit that performs control to position the reading element unit using the reading signal of the servo pattern read by the servo reading element and the linearity information acquired by the acquisition unit; a derivation unit that derives the amount of positional displacement between the magnetic tape and the reading element unit using the reading signal of the servo pattern while the control unit is performing control; and an extraction unit that extracts data recorded on the track to be read from the reading results by applying waveform equalization processing to each reading result for each reading element according to the amount of displacement derived by the derivation unit. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] U.S. Patent No. 8094402 [Patent Document 2] U.S. Patent No. 6781784 [Patent Document 3] Japanese Patent Publication No. 2009-123288 [Patent Document 4] Japanese Patent Publication No. 2000-260014 [Patent Document 5] Japanese Patent Publication No. 2020-140744 [Overview of the project]

[0008] One embodiment of the technology of this disclosure provides a servo pattern recording device, magnetic tape, magnetic tape cartridge, magnetic tape drive, magnetic tape system, detection device, inspection device, servo pattern recording method, magnetic tape manufacturing method, detection method, and inspection method that can obtain highly reliable servo signals. [Means for solving the problem]

[0009] A first aspect of the technology of the present disclosure is a servo pattern recording apparatus comprising a pulse signal generator and a servo pattern recording head, wherein the pulse signal generator generates a pulse signal, and the servo pattern recording head has a substrate and a plurality of gap patterns formed on the surface of the substrate, and records a plurality of servo patterns in the width direction of a magnetic tape by applying a magnetic field to the magnetic tape from the plurality of gap patterns according to the pulse signal, wherein the plurality of gap patterns are formed on the surface along a direction corresponding to the width direction, and the gap pattern is at least one pair of linear regions, a first linear region which is one of the linear regions of the pair of linear regions, and among the pair of linear regions This servo pattern recording device has a second linear region, which is the other linear region of the first linear region, tilted in a direction opposite to the first virtual line along the direction corresponding to the width direction on the surface, the first linear region has a steeper tilt angle with respect to the first virtual line than the second linear region, the positions of both ends of the first linear region and the positions of both ends of the second linear region are aligned in the direction corresponding to the width direction of the magnetic tape, and on the surface, multiple gap patterns are aligned in the longitudinal direction of the magnetic tape, and a pulse signal generator supplies pulse signals to each of the multiple gap patterns with a predetermined time delay from one side to the other in the direction in which the multiple gap patterns are arranged.

[0010] A second aspect of the technology of this disclosure is a servo pattern recording device according to the first aspect, wherein the substrate is formed in the shape of a rectangular parallelepiped and traverses the magnetic tape in a direction perpendicular to the longitudinal direction of the magnetic tape.

[0011] A third aspect of the technology of this disclosure is a servo pattern recording device according to the second aspect, wherein the surface is formed in a rectangular shape having a long side and a short side, and the length of the short side is long enough to accommodate a plurality of servo patterns.

[0012] A fourth aspect of the technology of this disclosure is a servo pattern recording device according to the third aspect, wherein the substrate is arranged on a magnetic tape in a orientation in which the orientation of the long side and the longitudinal direction of the magnetic tape are perpendicular to each other.

[0013] A fifth aspect of the technology of this disclosure is a servo pattern recording device according to any one of the first to fourth aspects, wherein the total length of the first linear region is shorter than the total length of the second linear region.

[0014] A sixth aspect of the technology of this disclosure is a servo pattern recording device according to any one of the first to fifth aspects, wherein the geometric characteristics on the surface of a pair of linear regions correspond to the geometric characteristics obtained when the entire pair of virtual linear regions is tilted with respect to the first virtual line by tilting the axis of symmetry of a pair of virtual linear regions, which are tilted symmetrically with respect to the first virtual line, with respect to the first virtual line, and the positions of both ends of one of the pair of virtual linear regions are aligned in a direction corresponding to the width direction.

[0015] A seventh aspect of the technology of this disclosure is a servo pattern recording device according to any one of the first to sixth aspects, wherein a magnetic tape has a plurality of servo bands formed along its width direction, and corresponding servo patterns between the servo bands are offset by a predetermined interval in the longitudinal direction of the magnetic tape between adjacent servo bands in the width direction, and a predetermined time is determined according to the predetermined interval.

[0016] An eighth aspect of the technology of this disclosure is a servo pattern recording device according to the seventh aspect, wherein a magnetic tape has a plurality of servo bands formed along the width direction, the servo bands are separated by frames defined based on at least one set of servo patterns, and a predetermined interval is defined based on the angle between corresponding frames and a first virtual straight line between adjacent servo bands in the width direction, and the pitch between adjacent servo bands in the width direction.

[0017] A ninth aspect of the technology of the present disclosure is a servo pattern recording device according to the seventh aspect, wherein a magnetic tape has a plurality of servo bands formed along the width direction, the servo bands are separated by frames defined based on at least one set of servo patterns, and a predetermined interval is defined based on the angle between frames that are not corresponding between adjacent servo bands in the width direction and a first virtual straight line, the pitch between adjacent servo bands in the width direction, and the total length of the frames in the longitudinal direction.

[0018] A tenth aspect of the technology of this disclosure is a magnetic tape on which a plurality of servo patterns are recorded by a servo pattern recording device according to any one of the first to ninth aspects.

[0019] An eleventh aspect of the technology of this disclosure is a magnetic tape cartridge comprising a magnetic tape according to the tenth aspect and a case in which the magnetic tape is housed.

[0020] A twelfth aspect of the technology of the present disclosure is a magnetic tape drive comprising: a travel mechanism for traveling a magnetic tape according to the tenth aspect along a predetermined path; and a magnetic head having a plurality of servo reading elements for reading a servo pattern on the predetermined path while the magnetic tape is being traveled by the travel mechanism, wherein the plurality of servo reading elements are arranged along the longitudinal direction of the magnetic head, and the magnetic head is positioned such that a second virtual straight line along the longitudinal direction of the magnetic head is inclined with respect to the travel direction of the magnetic tape.

[0021] According to a thirteenth aspect of the technology of the present disclosure, there is provided a magnetic tape system comprising: the magnetic tape according to the tenth aspect; and a magnetic tape drive on which a magnetic head is mounted, the magnetic head having a plurality of servo reading elements that read a servo pattern on a predetermined path while the magnetic tape is run along the predetermined path, wherein the plurality of servo reading elements are arranged along a longitudinal direction of the magnetic head, and the magnetic head is arranged in an orientation in which a third imaginary straight line along the longitudinal direction of the magnetic head is inclined with respect to a running direction of the magnetic tape.

[0022] A fourteenth aspect of the technology of the present disclosure is a detection apparatus comprising a processor, wherein the processor detects, using an autocorrelation coefficient, a servo signal that is a result of reading a servo pattern from the magnetic tape according to the tenth aspect by a servo reading element.

[0023] A fifteenth aspect of the technology of the present disclosure is a servo pattern recording method comprising: generating a pulse signal; and recording a plurality of servo patterns in a width direction of a magnetic tape by applying a magnetic field from a plurality of gap patterns to the magnetic tape in accordance with the pulse signal, using a servo pattern recording head having a base body and the plurality of gap patterns formed on a surface of the base body, wherein the plurality of gap patterns are formed on the surface along a direction corresponding to the width direction, each gap pattern is at least one linear region pair, a first linear region that is one linear region of the linear region pair and a second linear region that is the other linear region of the linear region pair are inclined in opposite directions with respect to a first imaginary straight line along the direction corresponding to the width direction on the surface, the first linear region has a steeper inclination angle with respect to the first imaginary straight line than the second linear region, positions of both ends of the first linear region and positions of both ends of the second linear region are aligned in the direction corresponding to the width direction of the magnetic tape, on the surface, the plurality of gap patterns have aligned positions in a longitudinal direction of the magnetic tape, and for each of the plurality of gap patterns, the pulse signal is supplied with a delay of a predetermined time from one side to the other side in a direction in which the plurality of gap patterns are arranged.

[0024] A 16th aspect related to the technology of the present disclosure is a magnetic tape manufacturing method comprising: a first step of recording a plurality of servo patterns on a magnetic tape in accordance with the servo pattern recording method according to a 15th aspect; and a second step of winding the magnetic tape.

[0025] A 17th aspect related to the technology of the present disclosure is an inspection apparatus comprising: a detection device according to a 14th aspect, the detection device being used together with the servo pattern recording apparatus according to a 1st aspect; and an inspection processor that inspects a servo band in which a servo pattern is recorded on a magnetic tape based on a servo signal detected by the detection device.

[0026] An 18th aspect related to the technology of the present disclosure is a detection method used together with the servo pattern recording method according to a 15th aspect, the detection method comprising detecting, using an autocorrelation coefficient, a servo signal that is a result of reading a servo pattern from the magnetic tape according to a 10th aspect by a servo reading element.

[0027] A 19th aspect related to the technology of the present disclosure is an inspection method comprising inspecting a servo band in which a servo pattern is recorded on a magnetic tape based on a servo signal detected by the detection method according to an 18th aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] [Figure 1] FIG. 1 is a block diagram illustrating an example configuration of a magnetic tape system according to an embodiment. [Figure 2] FIG. 2 is a schematic perspective view illustrating an example appearance of a magnetic tape cartridge according to an embodiment. [Figure 3] FIG. 3 is a schematic configuration diagram illustrating an example hardware configuration of a magnetic tape drive according to an embodiment. [Figure 4] FIG. 4 is a schematic perspective view illustrating an example aspect where a magnetic field is emitted from the lower side of the magnetic tape cartridge according to an embodiment by a non-contact read / write apparatus. [Figure 5]This is a schematic diagram showing an example of the hardware configuration of a magnetic tape drive according to the embodiment. [Figure 6] This is a conceptual diagram showing an example of a configuration in which a magnetic head is positioned on a conventionally known magnetic tape, as observed from the surface side of the magnetic tape. [Figure 7] This is a conceptual diagram showing an example of how a magnetic tape, before and after a conventionally known shrinkage in width, can be observed from the surface side of the magnetic tape. [Figure 8] This is a conceptual diagram showing an example of an observation of a state in which a magnetic head is skewed on a conventionally known magnetic tape, viewed from the surface side of the magnetic tape. [Figure 9] This is a conceptual diagram showing an example of a magnetic tape according to the embodiment as observed from the surface side of the magnetic tape. [Figure 10] This is a conceptual diagram 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 11] This is a conceptual diagram showing an example of an observation from the surface side of a magnetic tape in which corresponding frames are offset by a predetermined interval between adjacent servo bands in the width direction of the magnetic tape according to the embodiment. [Figure 12] This is a conceptual diagram showing an example of an observation from the surface side of a magnetic tape in which a servo pattern is read by a servo reading element included in a magnetic head that is not skewed on the magnetic tape according to the embodiment. [Figure 13] This is a conceptual diagram showing an example of an observation from the surface side of a magnetic tape in which a servo pattern is read by a servo reading element included in a skewed magnetic head on a magnetic tape according to the embodiment. [Figure 14] This is a conceptual diagram showing an example of the functions of a control device included in a magnetic tape drive according to the embodiment. [Figure 15] This is a conceptual diagram showing an example of the processing content of the position detection unit and control unit of the control device included in the magnetic tape drive according to the embodiment. [Figure 16] This is a conceptual diagram showing an example of the configuration of a servo writer according to the embodiment. [Figure 17] This is a conceptual diagram showing an example of the relationship between a pulse signal generator and a servo pattern recording head included in a servo writer according to the embodiment, and an example of a view of the servo pattern recording head included in the servo writer according to the embodiment being positioned on a magnetic tape, as observed from the surface side of the magnetic tape (i.e., the back side of the servo pattern recording head). [Figure 18] This is a conceptual diagram showing an example of how the servo pattern recording head included in the servo writer according to the embodiment is positioned on the magnetic tape, as observed from the surface side of the magnetic tape (i.e., the back side of the servo pattern recording head). [Figure 19] This is a conceptual diagram illustrating an example of the relationship between the geometric properties of an actual gap pattern and the geometric properties of a hypothetical gap pattern. [Figure 20] This is a conceptual diagram showing an example of how the servo pattern recording head of the first comparative example is positioned on the magnetic tape, as observed from the surface side of the magnetic tape (i.e., the back side of the servo pattern recording head). [Figure 21] This is a conceptual diagram showing an example of how the servo pattern recording head of the second comparative example is positioned on the magnetic tape, as observed from the surface side of the magnetic tape (i.e., the back side of the servo pattern recording head). [Figure 22] This is a conceptual diagram showing a first modified example of the magnetic tape according to the embodiment (a conceptual diagram showing an example of how the magnetic tape according to the first modified example is observed from the surface side of the magnetic tape). [Figure 23] This is a conceptual diagram showing an example of a servo pattern included in a magnetic tape according to the first modified example. [Figure 24] This is a conceptual diagram showing a first modified servo pattern recording head included in the servo writer according to the embodiment (a conceptual diagram showing an example of an appearance when the servo pattern recording head according to the first modified embodiment is placed on a magnetic tape and observed from the surface side of the magnetic tape (i.e., the back side of the servo pattern recording head)). [Figure 25]This is a conceptual diagram showing a second modified example of the magnetic tape according to the embodiment (a conceptual diagram showing an example of how the magnetic tape according to the second modified example is observed from the surface side of the magnetic tape). [Figure 26] This is a conceptual diagram showing an example of a servo pattern included in a magnetic tape according to the second modified example. [Figure 27] This is a conceptual diagram showing a second modified servo pattern recording head included in the servo writer according to the embodiment (a conceptual diagram showing an example of how the servo pattern recording head according to the second modified embodiment is arranged on a magnetic tape and observed from the surface side of the magnetic tape (i.e., the back side of the servo pattern recording head)). [Figure 28] This is a conceptual diagram showing an example of an observation from the surface side of a magnetic tape in which corresponding frames are offset by a predetermined interval between adjacent servo bands in the width direction of the magnetic tape according to the embodiment. [Modes for carrying out the invention]

[0029] Hereinafter, examples of embodiments of the servo pattern recording apparatus, magnetic tape, magnetic tape cartridge, magnetic tape drive, magnetic tape system, detection device, inspection device, servo pattern recording method, magnetic tape manufacturing method, detection method, and inspection method relating to the technology of this disclosure will be described with reference to the attached drawings.

[0030] First, let's explain the terminology used in the following explanation.

[0031] NVM stands for "Non-volatile memory". CPU stands for "Central Processing Unit". RAM stands for "Random Access Memory". EEPROM stands for "Electrically Erasable and Programmable Read Only Memory". SSD stands for "Solid State Drive". HDD stands for "Hard Disk Drive". ASIC stands for "Application Specific Integrated Circuit". FPGA stands for "Field-Programmable Gate Array". PLC stands for "Programmable Logic Controller". IC stands for "Integrated Circuit". RFID stands for "Radio Frequency Identifier". BOT stands for "Beginning Of Tape". EOT stands for "End Of Tape". UI stands for "User Interface". WAN stands for "Wide Area Network". LAN is an abbreviation for "Local Area Network".

[0032] As an example, as shown in Figure 1, the 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 the pulled-out magnetic tape MT is running, it records data to the magnetic tape MT or reads data from the magnetic tape MT.

[0033] In this embodiment, the magnetic tape MT is an example of a "magnetic tape" according to the technology of this disclosure. Also in this embodiment, the magnetic tape system 10 is an example of a "magnetic tape system" according to the technology of this disclosure. Also in this embodiment, the magnetic tape drive 14 is an example of a "magnetic tape drive" and "detection device" according to the technology of this disclosure. Also in this embodiment, the magnetic tape cartridge 12 is an example of a "magnetic tape cartridge" according to the technology of this disclosure.

[0034] Next, an example of the configuration of the magnetic tape cartridge 12 will be described with reference to Figures 2 to 4. For the sake of clarity, in the following explanation, in Figures 2 to 4, the loading direction of the magnetic tape cartridge 12 into the magnetic tape drive 14 is indicated by arrow A, the direction of arrow A is considered the front direction of the magnetic tape cartridge 12, and the side of the magnetic tape cartridge 12 facing forward is referred to as 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.

[0035] Furthermore, for the sake of clarity in the following explanation, in Figures 2 to 4, the direction of arrow B, which is perpendicular to the direction of arrow A, will be referred to as the right direction, and the right side of the magnetic tape cartridge 12 will be referred to 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.

[0036] Furthermore, for the sake of clarity in the following explanation, in Figures 2 to 4, the direction opposite to the direction of arrow B will be referred to as the left direction, and the left side of the magnetic tape cartridge 12 will be referred to as the left side of the magnetic tape cartridge 12. In the following description of the structure, "left" refers to the left side of the magnetic tape cartridge 12.

[0037] Furthermore, for the sake of clarity in the following explanation, in Figures 2 to 4, the direction perpendicular to arrows A and B is indicated by arrow C, the direction of arrow C is considered the upward direction of the magnetic tape cartridge 12, and the upward side of the magnetic tape cartridge 12 is referred to as the upper side of the magnetic tape cartridge 12. In the following description of the structure, "upper" refers to the upper side of the magnetic tape cartridge 12.

[0038] Furthermore, for the sake of clarity in the following explanation, in Figures 2 to 4, the direction opposite to the forward direction of the magnetic tape cartridge 12 will be referred to as the rear direction of the magnetic tape cartridge 12, and the side of the magnetic tape cartridge 12 in the rear direction will be 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.

[0039] Furthermore, for the sake of clarity in the following explanation, in Figures 2 to 4, the direction opposite to the upward direction of the magnetic tape cartridge 12 will be referred to as the downward direction of the magnetic tape cartridge 12, and the downward side of the magnetic tape cartridge 12 will be referred to as the lower side of the magnetic tape cartridge 12. In the following description of the structure, "down" refers to the lower side of the magnetic tape cartridge 12.

[0040] As an example, as shown in Figure 2, the magnetic tape cartridge 12 is approximately rectangular in plan view and comprises a box-shaped case 16. Case 16 is an example of a "case" related to the technology of this disclosure. The case 16 houses the magnetic tape MT. Case 16 is made of a resin such as polycarbonate and comprises an upper case 18 and a lower case 20. The upper case 18 and the lower case 20 are joined by welding (e.g., ultrasonic welding) and screw fastening, with the lower peripheral edge surface of the upper case 18 and the upper peripheral edge surface of the lower case 20 in contact. The joining method is not limited to welding and screw fastening, but may be other joining methods.

[0041] A discharge reel 22 is rotatably housed inside the case 16. The discharge reel 22 comprises a reel hub 22A, an upper flange 22B1, and a lower flange 22B2. The reel hub 22A is formed in a cylindrical shape. The reel hub 22A is the axial center of the discharge reel 22, and its axial direction is aligned with the vertical direction of the case 16, and it is located in the center of the case 16. The upper flange 22B1 and the lower flange 22B2 are each formed in an annular shape. The upper end of the reel hub 22A is fixed to the central part of the upper flange 22B1 in plan view, and the lower end of the reel hub 22A is fixed to the central part of the lower flange 22B2 in plan view. The reel hub 22A and the lower flange 22B2 may be integrally molded.

[0042] A magnetic tape MT is wound around the outer surface of the reel hub 22A, and the ends of the magnetic tape MT in the width direction are held by the upper flange 22B1 and the lower flange 22B2.

[0043] An opening 16B is formed on the front side of the right wall 16A of case 16. The magnetic tape MT is pulled out through the opening 16B.

[0044] A cartridge memory 24 is provided in the lower case 20. Specifically, the cartridge memory 24 is housed in the right rear end 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 types of information are read and written to the cartridge memory 24 without contact.

[0045] The cartridge memory 24 stores management information for managing the magnetic tape cartridge 12. This management information includes, for example, information about the cartridge memory 24 (e.g., information that can identify the magnetic tape cartridge 12), information about the magnetic tape MT (e.g., information indicating the recording capacity of the magnetic tape MT, information indicating an overview of the data recorded on the magnetic tape MT, information indicating the data items recorded on the magnetic tape MT, and information indicating the recording format of the data recorded on the magnetic tape MT), and information about the magnetic tape drive 14 (e.g., information indicating the specifications of the magnetic tape drive 14, and signals used by the magnetic tape drive 14).

[0046] As an example, as shown in Figure 3, the magnetic tape drive 14 includes a transport device 26, a magnetic head 28, a control device 30, a storage device 32, a UI system device 34, and a communication interface 35. A magnetic tape cartridge 12 is loaded into the magnetic tape drive 14 along 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.

[0047] The magnetic tape MT comprises a magnetic layer 29A, a base film 29B, and a back coat layer 29C. The magnetic layer 29A is formed on one side of the base film 29B, and the back coat layer 29C is formed on the other side of the base film 29B. Data is recorded on the magnetic layer 29A. The magnetic layer 29A contains ferromagnetic powder. As the ferromagnetic powder, for example, ferromagnetic powder commonly used in the magnetic layers of various magnetic recording media is used. A preferred specific example of ferromagnetic powder is hexagonal ferrite powder. Examples of hexagonal ferrite powder include hexagonal strontium ferrite powder or hexagonal barium ferrite powder. The back coat layer 29C is a layer containing non-magnetic powder such as carbon black. The base film 29B is also called a support and is formed of, for example, polyethylene terephthalate, polyethylene naphthalate, or polyamide. A non-magnetic layer may be formed between the base film 29B and the magnetic layer 29A. In a magnetic tape MT, the surface on which the magnetic layer 29A is formed is the surface 31 of the magnetic tape MT, and the surface on which the back coat layer 29C is formed is the back surface 33 of the magnetic tape MT.

[0048] The magnetic tape drive 14 performs magnetic processing on the surface 31 of the magnetic tape MT using a 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 performs data recording on the surface 31 of the magnetic tape MT and data reading 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 to read data from the surface 31 of the pulled-out magnetic tape MT using the magnetic head 28.

[0049] The control device 30 controls the entire magnetic tape drive 14. In this embodiment, the control device 30 is implemented by an ASIC, but the technology of this disclosure is not limited thereto. For example, the control device 30 may be implemented by an FPGA and / or a PLC. Alternatively, the control device 30 may be implemented by a computer including a CPU, flash memory (e.g., EEPROM and / or SSD, etc.), and RAM. Alternatively, it may be implemented by a combination of two or more of the ASIC, FPGA, PLC, and computer. In other words, the control device 30 may be implemented by a combination of hardware and software configurations. Note that the control device 30 is an example of a "processor" related to the technology of this disclosure.

[0050] The storage device 32 is connected to the control device 30, which writes various information to and reads various information from the storage device 32. An example of the storage device 32 is a flash memory and / or HDD. Flash memory and HDD are merely examples; any non-volatile memory that can be mounted on the magnetic tape drive 14 may be used.

[0051] The UI device 34 is a device that has a receiving function to receive instruction signals indicating instructions from the user and a presentation function to present information to the user. The receiving function is implemented by, for example, a touch panel, hard keys (e.g., a keyboard), and / or a mouse. The presentation function is implemented by, for example, a display, a printer, and / or a speaker. The UI device 34 is connected to the control device 30. The control device 30 acquires the instruction signals received by the UI device 34. Under the control of the control device 30, the UI device 34 presents various information to the user.

[0052] 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 such as a WAN and / or LAN (not shown). The communication interface 35 is responsible for the exchange of various types of information between the control device 30 and the external device 37 (for example, recording data for the magnetic tape MT, data read from the magnetic tape MT, and / or instruction signals given to the control device 30). Examples of the external device 37 include a personal computer or a mainframe.

[0053] The transport device 26 is a device that selectively transports a magnetic tape MT along a predetermined path in the forward and reverse directions, and includes a feed motor 36, a take-up reel 38, a take-up motor 40, and a plurality of guide rollers GR. Here, the forward direction refers to the direction in which the magnetic tape MT is fed out, and the reverse direction refers to the direction in which the magnetic tape MT is rewound. In this embodiment, the transport device 26 is an example of a "travel mechanism" according to the technology of this disclosure.

[0054] The feed motor 36 rotates the feed reel 22 inside the magnetic tape cartridge 12 under the control of the control device 30. The control device 30 controls the direction of rotation, rotation speed, and rotation torque of the feed reel 22 by controlling the feed motor 36.

[0055] The winding motor 40 rotates the winding reel 38 under the control of the control device 30. The control device 30 controls the winding motor 40 to control the rotation direction, rotation speed, and rotation torque of the winding reel 38.

[0056] When the magnetic tape MT is being wound onto the take-up reel 38, the control device 30 rotates the feed motor 36 and the take-up motor 40 so that the magnetic tape MT travels forward along a predetermined path. The rotational speed and torque of the feed 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 and torque of the feed motor 36 and the take-up motor 40, respectively, as controlled by the control device 30. The tension applied to the magnetic tape MT is controlled by adjusting the rotational speed and torque of the feed motor 36 and the take-up motor 40, respectively, as controlled by the control device 30.

[0057] When rewinding the magnetic tape MT onto the feed reel 22, the control device 30 rotates the feed motor 36 and the take-up motor 40 so that the magnetic tape MT travels in the reverse direction along a predetermined path.

[0058] In this embodiment, the tension applied to the magnetic tape MT is controlled by controlling the rotational speed and rotational torque of the delivery motor 36 and the winding motor 40, but the technology of this disclosure is not limited thereto. For example, the tension applied to the magnetic tape MT may be controlled using a dancer roller, or it may be controlled by pulling the magnetic tape MT into a vacuum chamber.

[0059] Each of the multiple guide rollers GR is a roller that guides the magnetic tape MT. The predetermined path, that is, the travel path of the magnetic tape MT, is determined by the arrangement of the multiple guide rollers GR in positions that straddle the magnetic head 28 between the magnetic tape cartridge 12 and the take-up reel 38.

[0060] The magnetic head 28 comprises a magnetic element unit 42 and a holder 44. The magnetic element unit 42 is held by the holder 44 so as to be in contact with the magnetic tape MT in motion. The magnetic element unit 42 has a plurality of magnetic elements.

[0061] 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 pattern 58 (see Figure 9), and data other than the servo pattern 58, i.e., data recorded in the data band DB (see Figure 9).

[0062] The magnetic tape drive 14 is equipped with a non-contact read / write device 46. The non-contact read / write device 46 is positioned on the underside of the magnetic tape cartridge 12 when the magnetic tape cartridge 12 is loaded, facing the back surface 24A of the cartridge memory 24, and reads and writes information to the cartridge memory 24 without contact.

[0063] As an example, as shown in Figure 4, the non-contact reading / writing device 46 emits a magnetic field MF from the underside of the magnetic tape cartridge 12 toward the cartridge memory 24. The magnetic field MF penetrates the cartridge memory 24.

[0064] 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 according to the control signal input from the control device 30 and emits the generated magnetic field MF toward the cartridge memory 24.

[0065] The contactless read / write device 46 performs contactless communication with the cartridge memory 24 via a magnetic field MF, thereby processing the cartridge memory 24 according to the control signal. For example, under the control of the control device 30, the contactless read / write device 46 selectively performs the process of reading information from the cartridge memory 24 and the process of storing information in the cartridge memory 24 (i.e., the process of writing information to the cartridge memory 24).

[0066] As an example, as shown in Figure 5, the magnetic tape drive 14 includes a moving mechanism 48. The moving mechanism 48 has a moving actuator 48A. Examples of the moving actuator 48A include a voice coil motor and / or a piezo actuator. The moving actuator 48A is connected to a control device 30, which controls the moving actuator 48A. The moving actuator 48A generates power under the control of the control device 30. The moving mechanism 48 moves the magnetic head 28 in the width direction of the magnetic tape MT by receiving the power generated by the moving actuator 48A.

[0067] 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 piezo actuator. The tilt actuator 49A is connected to a 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 (see Figure 8). That is, the magnetic head 28 skews on the magnetic tape MT under the control of the control device 30.

[0068] Here, as a comparative example to magnetic tape MT, we will explain the case where a conventionally known magnetic tape MT0 is used instead of magnetic tape MT, referring 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, while servo pattern 58 (see Figure 9) is applied to magnetic tape MT.

[0069] As an example, as shown in Figure 6, the surface 31 of the magnetic tape MT0 has servo bands SB1, SB2, and SB3, and data bands DB1 and DB2 formed thereon. For the sake of explanation, unless otherwise necessary, servo bands SB1 to SB3 will be referred to as servo band SB, and data bands DB1 and DB2 will be referred to as data band DB.

[0070] 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 direction in which the magnetic tape MT0 travels. The direction in which the magnetic tape MT0 travels is defined by two directions: the forward direction (hereinafter also simply referred to as the "forward direction"), which is the direction in which the magnetic tape MT0 travels from the delivery reel 22 side to the take-up reel 38 side, and the reverse direction (hereinafter also simply referred to as the "reverse direction"), which is the direction in which the magnetic tape MT0 travels from the take-up reel 38 side to the delivery reel 22 side.

[0071] The servo bands SB1 to SB3 are arranged at spaced-out positions in the width direction WD (hereinafter also simply referred to as "width direction WD") of the magnetic tape MT0. For example, the servo bands SB1 to SB3 are arranged at equal intervals along the width direction WD. In this embodiment, "equal intervals" refers not only to perfectly equal intervals but also to equal intervals that include errors that are generally acceptable in the art to which the disclosed technology belongs and that do not contradict the spirit of the disclosed technology.

[0072] Data band DB1 is positioned between servo band SB1 and servo band SB2, and data band DB2 is positioned between servo band SB2 and servo band SB3. In other words, servo bands SB and data bands DB are arranged alternately along the width direction WD.

[0073] In the example shown in Figure 6, for the sake of explanation, three servo bands SB and two data bands DB are shown. However, this is merely an example, and the technology of this disclosure can also be established with two servo bands SB and one data band DB, or with four or more servo bands SB and three or more data bands DB.

[0074] Multiple servo patterns 52 are recorded in the servo band SB along the longitudinal direction of the magnetic tape MT0. The servo patterns 52 are classified into servo patterns 52A and servo patterns 52B. The multiple servo patterns 52 are arranged at regular intervals along the longitudinal direction of the magnetic tape MT0. In this embodiment, "regular" refers not only to perfect regularity but also to regularity that includes errors that are generally acceptable in the art to which the present invention belongs and that do not contradict the spirit of the present invention.

[0075] The servo band SB is divided into multiple frames 50 along the longitudinal direction of the magnetic tape MT0. Each frame 50 is defined by a pair of servo patterns 52. In the example shown in Figure 6, servo patterns 52A and 52B are shown as an example of a pair of servo patterns 52. Servo patterns 52A and 52B are adjacent along the longitudinal direction of the magnetic tape MT0, with servo pattern 52A located on the forward upstream side and servo pattern 52B located on the forward downstream side within the frame 50.

[0076] The servo pattern 52 consists 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.

[0077] The servo pattern 52A consists of a pair of linear magnetization regions 54A. In the example shown in Figure 6, linear magnetization regions 54A1 and 54A2 are shown as an example of a pair of linear magnetization regions 54A. Each of the linear magnetization regions 54A1 and 54A2 is a linearly magnetized region.

[0078] The linear magnetization regions 54A1 and 54A2 are tilted in directions opposite to a virtual straight line C1, which is a virtual straight line along the width direction WD. In the example shown in Figure 6, the linear magnetization regions 54A1 and 54A2 are tilted symmetrically with respect to the virtual straight line C1. More specifically, the linear magnetization regions 54A1 and 54A2 are nonparallel to each other and are formed tilted by a predetermined angle (e.g., 5 degrees) in opposite directions on the longitudinal side of the magnetic tape MT0 with respect to the virtual straight line C1 as the axis of symmetry. In this embodiment, the virtual straight line C1 is an example of a "first virtual straight line" according to the technology of this disclosure.

[0079] A linear magnetization region 54A1 is a set of five magnetized straight lines, which are magnetization lines 54A1a. A linear magnetization region 54A2 is a set of five magnetized straight lines, which are magnetization lines 54A2a.

[0080] The servo pattern 52B consists of a pair of linear magnetization regions 54B. In the example shown in Figure 6, linear magnetization regions 54B1 and 54B2 are shown as an example of a pair of linear magnetization regions 54B. Each of the linear magnetization regions 54B1 and 54B2 is a linearly magnetized region.

[0081] The linear magnetization regions 54B1 and 54B2 are tilted in directions opposite to a virtual straight line C2, which is a virtual straight line along the width direction WD. In the example shown in Figure 6, the linear magnetization regions 54B1 and 54B2 are tilted symmetrically with respect to the virtual straight line C2. More specifically, the linear magnetization regions 54B1 and 54B2 are nonparallel to each other and are formed tilted by a predetermined angle (e.g., 5 degrees) in opposite directions on the longitudinal side of the magnetic tape MT0 with respect to the virtual straight line C2 as the axis of symmetry. In this embodiment, the virtual straight line C2 is an example of a "first virtual straight line" according to the technology of this disclosure.

[0082] A linear magnetization region 54B1 is a set of magnetization lines 54B1a, which are four magnetized straight lines. A linear magnetization region 54B2 is a set of magnetization lines 54B2a, which are four magnetized straight lines.

[0083] The magnetic head 28 is positioned on the surface 31 side of the magnetic tape MT0 configured in this way. The holder 44 is formed in the shape of a rectangular parallelepiped and is positioned to traverse the surface 31 of the magnetic tape MT0 in the width direction along WD. The multiple magnetic elements of the magnetic element unit 42 are arranged linearly along the longitudinal direction of the holder 44. The magnetic element unit 42 has a pair of servo reading elements SR and a plurality of data reading / writing elements DRW as multiple magnetic elements. The length of the holder 44 in the longitudinal direction is sufficiently long compared to the width of the magnetic tape MT0. For example, the length of the holder 44 in the longitudinal direction is set to exceed the width of the magnetic tape MT0 regardless of the position of the magnetic element unit 42 on the magnetic tape MT.

[0084] The pair of servo reading elements SR consists of servo reading elements SR1 and SR2. Servo reading element SR1 is located at one end of the magnetic element unit 42, and servo reading element SR2 is located at the other end of the magnetic element unit 42. In the example shown in Figure 6, servo reading element SR1 is located at a position corresponding to servo band SB2, and servo reading element SR2 is located at a position corresponding to servo band SB3.

[0085] Multiple data read / write elements DRW are arranged linearly between servo read element SR1 and servo read element SR2. Multiple data read / write elements DRW are arranged at intervals along the longitudinal direction of the magnetic head 28 (for example, at equal intervals along the longitudinal direction of the magnetic head 28). In the example shown in Figure 6, multiple data read / write elements DRW are provided at positions corresponding to data band DB2.

[0086] The control device 30 acquires a servo signal, which is the result of reading the servo pattern 52 by the servo reading element SR, and performs servo control according to the acquired servo signal. Here, servo control refers to the control that moves the magnetic head 28 in the width direction WD of the magnetic tape MT0 by operating the moving mechanism 48 according to the servo pattern 52 read by the servo reading element SR.

[0087] Through servo control, multiple data read / write elements (DRWs) are positioned over a designated area within the data band DB and perform magnetic processing on that area. In the example shown in Figure 6, magnetic processing is performed on a designated area within the data band DB2 by multiple data read / write elements (DRWs).

[0088] Furthermore, when the data band DB targeted for data reading by the magnetic element unit 42 is changed (in the example shown in Figure 6, when the data band DB targeted for data reading by the magnetic element unit 42 is changed from data band DB2 to DB1), the moving mechanism 48 changes the position of the pair of servo reading elements SR by moving the magnetic head 28 in the width direction WD under the control of the control device 30. Specifically, the moving mechanism 48 moves the magnetic head 28 in the width direction WD to move the servo reading element SR1 to the position corresponding to servo band SB1, and moves the servo reading element SR2 to the position corresponding to servo band SB2. As a result, the positions of the multiple data reading / writing elements DRW are changed from data band DB2 to data band DB1, and magnetic processing is performed on data band DB1 by the multiple data reading / writing elements DRW.

[0089] Incidentally, in recent years, research has been progressing on technologies to reduce the effects of TDS (Transverse Dimensional Stability). TDS is affected by temperature, humidity, the pressure on which the magnetic tape is wound around the reel, and degradation over time, and it is known that if no countermeasures are taken, TDS will increase, causing off-track (i.e., misalignment of the data read / write element DRW relative to the track in the data band DB) to occur when magnetic processing is performed on the data band DB.

[0090] In the example shown in Figure 7, the width of the magnetic tape MT0 is shown to shrink over time. In this case, off-tracking occurs. The width of the magnetic tape MT0 may also expand, and in this case, off-tracking also occurs. That is, if the width of the magnetic tape MT0 shrinks or expands over time, the position of the servo reading element SR relative to the servo pattern 52 deviates in the width direction WD from the design-defined default position (for example, the center position of each of the linear magnetization regions 54A1, 54A2, 54B1, and 54B2). If the position of the servo reading element SR relative to the servo pattern 52 deviates in the width direction WD from the design-defined default position, the accuracy of the servo control decreases, and the position of the track in the data band DB and the data read / write element DRW become misaligned. As a result, magnetic processing is not performed on the track that was originally planned.

[0091] As an example of a method to reduce the effects of TDS, as shown in Figure 8, a method is known in which the position of the servo reading element SR relative to the servo pattern 52 is maintained at a predetermined position as determined by the design by skewing the magnetic head 28 on the magnetic tape MT0.

[0092] The magnetic head 28 is provided with a rotation axis RA. The rotation axis RA is located at a position corresponding to the center of the magnetic element unit 42 included in the magnetic head 28 in a plan view. The magnetic head 28 is rotatably held by the tilt mechanism 49 via the rotation axis RA. The magnetic head 28 is provided with a virtual straight line C3, which is a virtual center line. The virtual straight line C3 is a straight line that passes through the rotation axis RA and extends in the longitudinal direction of the magnetic head 28 in a plan view (i.e., the direction in which the multiple data read / write elements DRW are arranged). The magnetic head 28 is held by the tilt mechanism 49 such that the virtual straight line C3 is tilted toward the longitudinal direction of the magnetic tape MT0 with respect to a virtual straight line C4, which is a virtual straight line along the width direction WD. In the example shown in Figure 8, the magnetic head 28 is held by the tilt mechanism 49 in a position where the virtual straight line C3 is tilted toward the feed reel 22 side with respect to the virtual straight line C4 (i.e., tilted counterclockwise when viewed from the front side of the paper in Figure 8). In this embodiment, the virtual line C3 is an example of the "second virtual line" and the "third virtual line" related to the technology of this disclosure.

[0093] The tilting mechanism 49 receives power from the tilting actuator 49A (see Figure 5) to rotate the magnetic head 28 on the surface 31 of the magnetic tape MT0 around the rotation axis RA. Under the control of the control device 30, the tilting mechanism 49 rotates the magnetic head 28 on the surface 31 of the magnetic tape MT0 around the rotation axis RA, thereby changing the direction and angle of the inclination (i.e., azimuth) of the virtual straight line C3 with respect to the virtual straight line C4.

[0094] The direction and angle of the inclination of the virtual straight line C3 relative to the virtual straight line C4 are changed in accordance with temperature, humidity, the pressure applied when the magnetic tape MT0 is wound onto the reel, and deterioration over time, or the expansion and contraction of the magnetic tape MT in the width direction WD caused by these factors, thereby maintaining the position of the servo reading element SR relative to the servo pattern 52 at a predetermined position as defined by the design.

[0095] Incidentally, the servo reading element SR is formed linearly along the virtual straight line C3. Therefore, when the servo pattern 52A is read by the servo reading element SR, the angle between the linear magnetization region 54A1 and the servo reading element SR is different from the angle between the linear magnetization region 54A2 and the servo reading element SR in the linear magnetization region pair 54A. When the angles are different in this way, variations due to azimuth loss (for example, variations in signal level and waveform distortion) occur between the servo signal originating from the linear magnetization region 54A1 (i.e., the servo signal obtained when the linear magnetization region 54A1 is read by the servo reading element SR) and the servo signal originating from the linear magnetization region 54A2 (i.e., the servo signal obtained when the linear magnetization region 54A2 is read by the servo reading element SR). In the example shown in Figure 8, the angle between the servo reading element SR and the linear magnetization region 54A1 is larger than the angle between the servo reading element SR and the linear magnetization region 54A2. As a result, the servo signal output is smaller and the waveform is broader, causing variations in the servo signal read by the servo reading element SR across the servo band SB while the magnetic tape MT is running. Furthermore, even when the servo pattern 52B is read by the servo reading element SR, variations due to azimuth loss occur between the servo signal originating from the linear magnetization region 54B1 and the servo signal originating from the linear magnetization region 54B2. Such variations in the servo signal can contribute to a decrease in the accuracy of servo control.

[0096] Furthermore, as another example of a conventionally known servo pattern 52A, one can consider a configuration in which the linear magnetization region 54A1 is parallel to a virtual straight line C1, and the linear magnetization region 54A2 is inclined with respect to the virtual straight line C1 (i.e., a configuration in which only the linear magnetization region 54A2 is inclined). In this conventionally known configuration as well, when the servo pattern 52A is read by the servo reading element SR, the angle between the linear magnetization region 54A1 and the servo reading element SR is different from the angle between the linear magnetization region 54A2 and the servo reading element SR in the linear magnetization region pair 54A. When the angles are different in this way, variations due to azimuth loss occur between the servo signal originating from the linear magnetization region 54A1 and the servo signal originating from the linear magnetization region 54A2. Such variations in the servo signal can contribute to a decrease in the accuracy of servo control.

[0097] Therefore, in light of these circumstances, in this embodiment, as an example, a magnetic tape MT is used, as shown in Figure 9. The magnetic tape MT differs from the magnetic tape MT0 in that it has a frame 56 instead of a frame 50. The frame 56 is defined by a set of servo patterns 58. Multiple servo patterns 58 are recorded in the servo band SB along the longitudinal direction LD. The multiple servo patterns 58 are arranged at regular intervals along the longitudinal direction LD, similar to the multiple servo patterns 52 recorded on the magnetic tape MT0.

[0098] In the example shown in Figure 9, servo patterns 58A and 58B are shown as an example of a pair of servo patterns 58 included in frame 56. Servo patterns 58A and 58B are adjacent to each other along the longitudinal direction LD, with servo pattern 58A located on the upstream side in the forward direction and servo pattern 58B located on the downstream side in the forward direction within frame 56.

[0099] The servo pattern 58 consists of linear magnetization region pairs 60. The linear magnetization region pairs 60 are classified into linear magnetization region pair 60A and linear magnetization region pair 60B.

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

[0101] The linear magnetization regions 60A1 and 60A2 are tilted in opposite directions with respect to the virtual line C1. In other words, linear magnetization region 60A1 is tilted in one direction with respect to the virtual line C1 (for example, clockwise when viewed from the front side of the paper in Figure 9). On the other hand, linear magnetization region 60A2 is tilted in the other direction with respect to the virtual line C1 (for example, counterclockwise when viewed from the front side of the paper in Figure 9). Linear magnetization regions 60A1 and 60A2 are nonparallel to each other and are tilted at different angles with respect to the virtual line C1. Linear magnetization region 60A1 has a steeper tilt angle with respect to the virtual line C1 than linear magnetization region 60A2. Here, "steep" means, for example, that the angle of linear magnetization region 60A1 with respect to the virtual line C1 is smaller than the angle of linear magnetization region 60A2 with respect to the virtual line C1. Furthermore, the total length of linear magnetization region 60A1 is shorter than the total length of linear magnetization region 60A2.

[0102] In servo pattern 58A, linear magnetization region 60A1 contains multiple magnetization lines 60A1a, and linear magnetization region 60A2 contains multiple magnetization lines 60A2a. The number of magnetization lines 60A1a contained in linear magnetization region 60A1 is the same as the number of magnetization lines 60A2a contained in linear magnetization region 60A2.

[0103] A linear magnetization region 60A1 is a set of five magnetized straight lines, which are magnetization lines 60A1a, and a linear magnetization region 60A2 is a set of five magnetized straight lines, which are magnetization lines 60A2a. Within the servo band SB, the positions of both ends of the linear magnetization region 60A1 (i.e., the positions of each of the five magnetization lines 60A1a) and the positions of both ends of the linear magnetization region 60A2 (i.e., the positions of each of the five magnetization lines 60A2a) are aligned in the width direction WD. Here, we have given an example where 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. However, this is merely one example, and it is sufficient if the positions of the ends of one or more of the five magnetization lines 60A1a and the positions of the ends of one or more of the five magnetization lines 60A2a are aligned. Furthermore, in this embodiment, the concept of "aligned" includes not only the meaning of being perfectly aligned, but also the meaning of "aligned" including errors that are generally acceptable in the art to which the disclosed technology belongs and that do not contradict the spirit of the disclosed technology.

[0104] The servo pattern 58B consists of a pair of linear magnetization regions 60B. In the example shown in Figure 9, linear magnetization regions 60B1 and 60B2 are shown as an example of a pair of linear magnetization regions 60B. Each of the linear magnetization regions 60B1 and 60B2 is a linearly magnetized region.

[0105] The linear magnetization regions 60B1 and 60B2 are tilted in opposite directions with respect to the virtual line C2. In other words, linear magnetization region 60B1 is tilted in one direction with respect to the virtual line C2 (for example, clockwise when viewed from the front side of the paper in Figure 9). On the other hand, linear magnetization region 60B2 is tilted in the other direction with respect to the virtual line C2 (for example, counterclockwise when viewed from the front side of the paper in Figure 9). Linear magnetization regions 60B1 and 60B2 are nonparallel to each other and are tilted at different angles with respect to the virtual line C2. Linear magnetization region 60B1 has a steeper tilt angle with respect to the virtual line C2 than linear magnetization region 60B2. Here, "steep" means, for example, that the angle of linear magnetization region 60B1 with respect to the virtual line C2 is smaller than the angle of linear magnetization region 60B2 with respect to the virtual line C2. Furthermore, the total length of the linear magnetization region 60B1 is shorter than the total length of the linear magnetization region 60B2.

[0106] In servo pattern 58B, the linear magnetization region 60B1 contains multiple magnetization lines 60B1a, and the linear magnetization region 60B2 contains multiple magnetization lines 60B2a. The number of magnetization lines 60B1a contained in the linear magnetization region 60B1 is the same as the number of magnetization lines 60B2a contained in the linear magnetization region 60B2.

[0107] The total number of magnetization lines 60B1a and 60B2a included in servo pattern 58B is different from the total number of magnetization lines 60A1a and 60A2a included in servo pattern 58A. In the example shown in Figure 9, the total number of magnetization lines 60A1a and 60A2a included in servo pattern 58A is 10, while the total number of magnetization lines 60B1a and 60B2a included in servo pattern 58B is 8.

[0108] A linear magnetization region 60B1 is a set of four magnetized straight lines, which are magnetization lines 60B1a, and a linear magnetization region 60B2 is a set of four magnetized straight lines, which are magnetization lines 60B2a. Within the servo band SB, the positions of both ends of the linear magnetization region 60B1 (i.e., the positions 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 each of the four magnetization lines 60B2a) are aligned in the width direction WD.

[0109] Note that here we have given an example where 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. However, this is merely one example, and it is sufficient if the positions of the ends of one or more of the four magnetization lines 60B1a and the positions of the ends of one or more of the four magnetization lines 60B2a are aligned.

[0110] Furthermore, while examples of linear magnetization regions 60A1, 60B1, 60B2, and 60B2 are given, the technology of this disclosure is not limited to these examples. For example, linear magnetization region 60A1 may be a number of magnetization lines 60A1a that contribute to identifying the position of the magnetic head 28 on the magnetic tape MT, linear magnetization region 60A2 may be a number of magnetization lines 60A2a that contribute to identifying the position of the magnetic head 28 on the magnetic tape MT, linear magnetization region 60B1 may be a number of magnetization lines 60B1a that contribute to identifying the position of the magnetic head 28 on the magnetic tape MT, and linear magnetization region 60B2 may be a number of magnetization lines 60B2a that contribute to identifying the position of the magnetic head 28 on the magnetic tape MT.

[0111] Here, the geometric characteristics of the linear magnetization region pair 60A on the magnetic tape MT will be described with reference to Figure 10. In this embodiment, geometric characteristics refer to generally recognized geometric characteristics such as length, shape, orientation, and / or position.

[0112] As an example, as shown in Figure 10, the geometric characteristics of the linear magnetization region pair 60A on the magnetic tape MT can be represented using a virtual linear region 62. The virtual linear region pair 62 consists of a virtual linear region 62A and a virtual linear region 62B.

[0113] The virtual linear region pair 62 is a hypothetical linear magnetization region pair having the same geometric properties as the linear magnetization region pair 54A shown in Figure 6. The virtual linear region pair 62 is a hypothetical magnetization region used for convenience to explain the geometric properties of the linear magnetization region pair 60A on the magnetic tape MT, and is not an actual magnetization region.

[0114] The virtual linear region 62A has the same geometric characteristics as the linear magnetization region 54A1 shown in Figure 6, and consists of five virtual lines 62A1 corresponding to the five magnetization lines 54A1a shown in Figure 6. The virtual linear region 62B has the same geometric characteristics as the linear magnetization region 54B1 shown in Figure 6, and consists of five virtual lines 62B1 corresponding to the five magnetization lines 54A2a shown in Figure 6.

[0115] A center O1 is provided in the virtual linear region pair 62. For example, center O1 is the center of the line segment L0 that connects the center of line 62A1, which is located on the upstream side in the forward direction of the five lines 62A1, and the center of line 62B1, which is located on the downstream side in the forward direction of the five lines 62B1.

[0116] Since the virtual linear region pair 62 has the same geometric characteristics as the linear magnetization region pair 54A shown in Figure 6, the virtual linear region 62A and virtual linear region 62B are tilted symmetrically with respect to the virtual line C1. Now, let's consider the case where the entire virtual linear region pair 62 is tilted with respect to the virtual line C1 by tilting the axis of symmetry SA1 of the virtual linear regions 62A and 62B by an angle a (for example, 10 degrees) with respect to the virtual line C1, using the center O1 as the axis of rotation, and then reading is performed on the virtual linear region pair 62 using a servo reading element SR. In this case, within the virtual linear region pair 62, there are areas 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. In other words, when reading is performed by the servo reading element SR in each of the virtual linear regions 62A and 62B, there will be a missing portion and an unnecessary portion.

[0117] Therefore, by supplementing the missing parts and removing the unnecessary parts, the positions of both ends of the virtual linear region 62A (i.e., the positions of both ends of each of the five straight lines 62A1) and the positions of both ends of the virtual linear region 62B (i.e., the positions of both ends of each of the five straight lines 62B1) are aligned in the width direction WD.

[0118] The geometric characteristics of the virtual linear region pair 62 obtained in this way (i.e., the geometric characteristics of the virtual servo pattern) correspond to the geometric characteristics of the actual servo pattern 58A. That is, the servo band SB records a linear magnetization region pair 60A with geometric characteristics corresponding 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 with the positions of both ends of the virtual linear region 62B in the width direction WD.

[0119] Note that the linear magnetization region pair 60B differs from the linear magnetization region pair 60A only in that it has four magnetization lines 60B1a instead of five magnetization lines 60A1a, and four magnetization lines 60B2a instead of five magnetization lines 60A2a. Therefore, the servo band SB records the linear magnetization region pair 60B, whose geometric characteristics correspond to those of a virtual linear region pair (not shown) obtained by aligning the positions of both ends of the four lines 62A1 with the positions of both ends of the four lines 62B1 in the width direction WD.

[0120] As an example, as shown in Figure 11, the magnetic tape MT has multiple servo bands SB formed in the width direction WD, and the frames 56 that are in a corresponding relationship between servo bands SB are shifted by a predetermined interval in the longitudinal direction LD between adjacent servo bands SB in the width direction WD. This means that the servo patterns 58 that are in a corresponding relationship between servo bands SB are shifted by a predetermined interval in the longitudinal direction LD between adjacent servo bands SB in the width direction WD.

[0121] The default interval is defined based on angle α, the pitch between adjacent servo bands SB in the width direction WD (hereinafter also referred to as "servo band pitch"), and the frame length. In the example shown in Figure 11, angle α is exaggerated to make it easier to understand visually, but in reality, angle α is, for example, about 15 degrees. Angle α is the angle formed between frames 56 that are not in a corresponding relationship between adjacent servo bands SB in the width direction WD and a virtual straight line C1. In the example shown in Figure 11, as an example of angle α, the angle formed between one frame 56 of a pair of corresponding frames 56 between adjacent servo bands SB in the width direction WD (one frame 56 of servo band SB3 in the example shown in Figure 11) and the frame 56 adjacent to the other frame 56 of the pair of frames 56 (one frame 56 of servo band SB3 in the example shown in Figure 11, among the multiple frames 56 in servo band SB2, the frame 56 that corresponds to one frame 56 of servo band SB3) (line segment L1 in the example shown in Figure 11) and a virtual straight line C1 is shown. In this case, frame length refers to the total length of frame 56 in the longitudinal direction LD. The default spacing is defined by the following formula (1). Note that Mod(A / B) means the remainder obtained when "A" is divided by "B".

[0122] (Default interval) = Mod{(Servo band pitch × tanα) / (Frame length)} ... (1)

[0123] In the example shown in Figure 11, angle α is exemplified as the angle formed between one frame 56 of a pair of frames 56 that correspond to adjacent servo bands SB in the width direction WD (hereinafter also referred to as the "first frame") and the frame 56 adjacent to the other frame 56 of the pair of frames 56 (hereinafter also referred to as the "second frame"), and the virtual line C1. However, the technology of this disclosure is not limited to this. For example, angle α may be the angle formed between the first corresponding frame and a frame 56 (hereinafter also referred to as the "third frame") located two or more frames away from the second frame within the same servo band SB as the second frame, and the virtual line C1. In this case, the "frame length" used in formula (1) is the pitch between the second frame and the third frame in the longitudinal direction LD (for example, the distance from the tip of the second frame to the tip of the third frame).

[0124] As an example, as shown in Figure 12, when the servo pattern 58A (i.e., linear magnetization region pair 60A) is read by the servo reading element SR when the direction of virtual line C1 and the direction of virtual line C3 coincide (i.e., the longitudinal direction and width direction WD of the magnetic head 28 coincide), variations due to azimuth loss occur between the servo signal originating from linear magnetization region 60A1 and the servo signal originating from linear magnetization region 60A2. A similar phenomenon occurs when the servo pattern 58B (i.e., linear magnetization region pair 60B) is read by the servo reading element SR when the direction of virtual line C1 and the direction of virtual line C3 coincide (i.e., the longitudinal direction and width direction WD of the magnetic head 28 coincide).

[0125] Therefore, as an example shown in Figure 13, the tilting mechanism 49 (see Figure 8) skews the magnetic head 28 on the magnetic tape MT around the rotation axis RA such that the virtual line C3 is tilted at an angle β (i.e., an angle β counterclockwise when viewed from the front side of the paper in Figure 13) relative to the virtual line C1. In this way, the magnetic head 28 is tilted at an angle β towards the upstream side in the forward direction on the magnetic tape MT, so the variation due to azimuth loss between the servo signal originating from the linear magnetization region 60A1 and the servo signal originating from the linear magnetization region 60A2 is reduced compared to the example shown in Figure 12. Similarly, when the servo pattern 58B (i.e., the linear magnetization region pair 60B) is read by the servo reading element SR, the variation due to azimuth loss between the servo signal originating from the linear magnetization region 60B1 and the servo signal originating from the linear magnetization region 60B2 is also reduced.

[0126] Here, angle β is set to coincide with angle a (see Figure 10), which is the angle obtained by rotating the axis of symmetry SA1 (see Figure 10) of the virtual linear regions 62A and 62B (see Figure 10) with respect to the virtual straight line C1, with the center O1 (see Figure 10) as the axis of rotation. In this embodiment, "coincidence" refers not only to a perfect coincidence but also to an error that is generally acceptable in the art to which the present disclosure belongs and does not contradict the spirit of the present disclosure. The geometric characteristics of the virtual linear regions 62A and 62B are the same as the geometric characteristics of the linear magnetization regions 60A1 and 60B1. Therefore, the linear magnetization regions 60A1 and 60B1 are also inclined at angle a with respect to the virtual straight line C1. In this case, when the magnetic head 28 is inclined at angle β (i.e., angle a) on the magnetic tape MT towards the upstream side in the forward direction, the inclination angle β of the magnetic head 28 coincides with the inclination angle a of the linear magnetization regions 60A1 and 60A2. As a result, the variation due to azimuth loss between the servo signal originating from linear magnetization region 60A1 and the servo signal originating from linear magnetization region 60A2 is reduced. Similarly, when the servo pattern 58B (i.e., the linear magnetization region pair 60B) is read by the servo reading element SR, the variation due to azimuth loss between the servo signal originating from linear magnetization region 60B1 and the servo signal originating from linear magnetization region 60B2 is also reduced.

[0127] As an example, as shown in Figure 14, the control device 30 includes a control unit 30A and a position detection unit 30B. The position detection unit 30B includes a first position detection unit 30B1 and a second position detection unit 30B2. The position detection unit 30B acquires a servo signal, which is the result of reading the servo pattern 58 by the servo reading element SR, and detects the position of the magnetic head 28 on the magnetic tape MT based on the acquired servo signal.

[0128] The servo signals are classified into a first servo signal and a second servo signal. The first servo signal is the servo signal resulting from the reading of the servo pattern 58 by the servo reading element SR1, and the second servo signal is the servo signal resulting from the reading of the servo pattern 58 by the servo reading element SR2.

[0129] The first position detection unit 30B1 acquires a first servo signal, and the second position detection unit 30B2 acquires a second servo signal. In the example shown in Figure 14, the first position detection unit 30B1 acquires a first servo signal obtained by reading the servo pattern 58 in the servo band SB2 with the servo reading element SR1, and the second position detection unit 30B2 acquires a second servo signal obtained by reading the servo pattern 58 in the servo band SB3 with the servo reading element SR2. Based on the first servo signal, the first position detection unit 30B1 detects the position of the servo reading element SR1 relative to the servo band SB2, and based on the second servo signal, the second position detection unit 30B2 detects the position of the servo reading element SR2 relative to the servo band SB3.

[0130] The control unit 30A performs various controls based on the position detection result from the first position detection unit 30B1 (i.e., the result of position detection by the first position detection unit 30B1) and the position detection result from the second position detection unit 30B2 (i.e., the result of position detection by the second position detection unit 30B2). Here, various controls refer to, for example, servo control, skew angle control, and / or tension control. Tension control refers to the control of the tension applied to the magnetic tape MT (for example, tension to reduce the effect of TDS).

[0131] As an example, as shown in Figure 15, the position detection unit 30B detects the servo signal, which is the result of reading the servo pattern 58 from the magnetic tape MT by the servo reading element SR, using the autocorrelation coefficient.

[0132] The storage 32 stores an ideal waveform signal 66. The ideal waveform signal 66 is a signal that represents a single ideal waveform included in the servo signal (for example, an ideal signal resulting from one of the ideal magnetization lines included in the servo pattern 58 being read by the servo reading element SR). The ideal waveform signal 66 can also be said to be a sample signal compared with the servo signal. Here, an example of how the ideal waveform signal 66 is stored in the storage 32 is given, but this is merely one example, and for example, the ideal waveform signal 66 may be stored in the cartridge memory 24 instead of, or together with, the storage 32. Furthermore, the ideal waveform signal 66 may be recorded in the BOT area (not shown) provided at the beginning of the magnetic tape MT, and / or in the EOT area (not shown) provided at the end of the magnetic tape MT.

[0133] The autocorrelation coefficient used by the position detection unit 30B is a coefficient that indicates the degree of correlation between the servo signal and the ideal waveform signal 66. The position detection unit 30B acquires the ideal waveform signal 66 from the storage 32 and compares the acquired ideal waveform signal 66 with the servo signal. Then, the position detection unit 30B calculates the autocorrelation coefficient based on the comparison result. On the servo band SB, the position detection unit 30B detects positions where the correlation between the servo signal and the ideal waveform signal 66 is high (for example, positions where the servo signal and the ideal waveform signal 66 coincide) according to the autocorrelation coefficient.

[0134] The position of the servo reading element SR relative to the servo band SB is detected, for example, as follows. The autocorrelation coefficient makes it possible to detect the spacing of the longitudinal LD ​​of the servo patterns 58A and 58B. For example, if the servo reading element SR is located on the upper side of the servo pattern 58 (i.e., the upper side in the front view of the paper in Figure 14), the spacing between linear magnetization regions 60A1 and 60A2 becomes narrower, and the spacing between linear magnetization regions 60B1 and 60B2 also becomes narrower. Conversely, if the servo reading element SR is located on the lower side of the servo pattern 58 (i.e., the lower side in the front view of the paper in Figure 14), the spacing between linear magnetization regions 60A1 and 60A2 becomes wider, and the spacing between linear magnetization regions 60B1 and 60B2 also becomes wider. In this way, the position detection unit 30B uses the distance between linear magnetization regions 60A1 and 60A2, and the distance between linear magnetization regions 60B1 and 60B2, detected according to the autocorrelation coefficient, to detect the position of the servo reading element SR relative to the servo band SB. The control unit 30A adjusts the position of the magnetic head 28 by operating the movement mechanism 48 based on the position detection result from the position detection unit 30B (i.e., the result of 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 acquires a read signal (data read from the data band DB of the magnetic tape MT by the magnetic element unit 42) from the magnetic element unit 42, or 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.

[0135] Furthermore, in order 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 or skews the magnetic head 28 on the magnetic tape MT according to the calculated servo band pitch. Tension control is achieved by adjusting the rotational speed and rotational torque of the feed motor 36 and the winding motor 40, respectively. Skew of the magnetic head 28 is achieved by operating the tilting mechanism 49.

[0136] Next, an example of a servo pattern recording process, in which a servo pattern 58 is recorded on the servo band SB of the magnetic tape MT, and an example of a winding process, in which the magnetic tape MT is wound up, will be described.

[0137] As an example, as shown in Figure 16, a servo writer SW is used in the servo pattern recording process. The servo writer SW includes a feed reel SW1, a take-up reel SW2, a drive unit SW3, a pulse signal generator SW4, a control unit SW5, multiple guides SW6, a transport path SW7, and a servo pattern recording head WH and a verify head VH.

[0138] In this embodiment, the servo writer SW is an example of a "servo pattern recording device" and an "inspection device" according to the technology of this disclosure. Also in this embodiment, the pulse signal generator SW4 is an example of a "pulse signal generator" according to the technology of this disclosure. Also in this embodiment, the servo pattern recording head WH is an example of a "servo pattern recording head" according to the technology of this disclosure. Also in this embodiment, the control device SW5 is an example of an "inspection processor" according to the technology of this disclosure.

[0139] The control device SW5 controls the entire servo writer SW. In this embodiment, the control device SW5 is implemented by an ASIC, but the technology of this disclosure is not limited thereto. For example, the control device SW5 may be implemented by an FPGA and / or a PLC. Alternatively, the control device SW5 may be implemented by a computer including a CPU, flash memory (e.g., EEPROM and / or SSD, etc.), and RAM. Alternatively, it may be implemented by a combination of two or more of the ASIC, FPGA, PLC, and computer. In other words, the control device SW5 may be implemented by a combination of hardware and software configurations.

[0140] The delivery reel SW1 is equipped with a pancake. A pancake refers to a large-diameter roll on which magnetic tape MT, cut to the product width from a wide web roll before the servo pattern 58 is written, is wound around a hub.

[0141] The drive unit SW3 has a motor (not shown) and gears (not shown) and is mechanically connected to the delivery reel SW1 and the take-up reel SW2. When the magnetic tape MT is being taken up by the take-up reel SW2, the drive unit SW3 generates power according to instructions from the control device SW5 and transmits the generated power to the delivery reel SW1 and the take-up reel SW2, thereby rotating them. That is, the delivery reel SW1 rotates by receiving power from the drive unit SW3 and sends the magnetic tape MT to the predetermined transport path SW7. The take-up reel SW2 rotates by receiving power from the drive unit SW3 and takes up the magnetic tape MT sent out from the delivery reel SW1. The rotational speed and rotational torque of the delivery reel SW1 and the take-up reel SW2 are adjusted according to the speed at which the magnetic tape MT is taken up by the take-up reel SW2.

[0142] Multiple guide SW6 and a servo pattern recording head WH are arranged on the transport path SW7. The servo pattern recording head WH is positioned on the surface 31 side of the magnetic tape MT between the multiple guide SW6. The magnetic tape MT, which is sent from the delivery reel SW1 to the transport path SW7, is guided by the multiple guide SW6, passes over the servo pattern recording head WH, and is then wound up by the take-up reel SW2.

[0143] The manufacturing process for magnetic tape (MT) includes several steps in addition to the servo pattern recording process. These steps include inspection and winding processes.

[0144] For example, the inspection process is a process of inspecting the servo band SB formed on the surface 31 of the magnetic tape MT by the servo pattern recording head WH. Inspection of the servo band SB refers to a process of determining whether the servo pattern 58 recorded on the servo band SB is correct or incorrect. Determining whether the servo pattern 58 is correct or incorrect refers to determining whether the magnetization lines 60A1a, 60A2a, 60B1a, and 60B2a are recorded within the allowable error range for predetermined locations on the surface 31 of the servo patterns 58A and 58B (i.e., verifying the servo pattern 58).

[0145] The inspection process is performed using the control device SW5 and the verify head VH. The verify head VH is positioned downstream of the servo pattern recording head WH in the transport direction of the magnetic tape MT. In addition, the verify head VH is equipped with multiple servo reading elements (not shown), similar to the magnetic head 28, and readings are performed on multiple servo bands SB by multiple servo reading elements. Furthermore, the verify head VH is skewed on the surface 31 of the magnetic tape MT, similar to the magnetic head 28.

[0146] The verify head VH is connected to the control device SW5. The verify head VH is positioned to face 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), and reads the servo pattern 58 recorded on the servo band SB and outputs the reading result (hereinafter referred to as "servo pattern reading result") to the control device SW5. The control device SW5 performs inspection of the servo band SB (for example, determining whether the servo pattern 58 is correct or incorrect) based on the servo pattern reading result (for example, servo signal) input from the verify head VH. For example, the control device SW5 operates as a position detection unit 30B as shown in Figure 14 to obtain a position detection result from the servo pattern reading result, and performs inspection of the servo band SB by determining whether the servo pattern 58 is correct or incorrect using the position detection result.

[0147] The control device SW5 outputs information indicating the result of inspecting the servo band SB (for example, the result of determining whether the servo pattern 58 is correct or incorrect) to a predetermined output destination (for example, storage 32 (see Figure 3), UI system device 34 (see Figure 3), and / or external device 37 (see Figure 3), etc.).

[0148] For example, once the inspection process is complete, the winding process is performed. The winding process involves winding the magnetic tape MT onto a delivery reel 22 used for each of the multiple magnetic tape cartridges 12 (see Figures 1 to 4) (i.e., the delivery reels 22 housed in the magnetic tape cartridges 12 (see Figures 1 to 4) (see Figures 2 to 4)). A winding motor M is used in the winding process. The winding motor M is mechanically connected to the delivery reel 22 via gears or the like. Under the control of a control device (not shown), the winding motor M rotates the delivery reel 22 by applying rotational force to it. The magnetic tape MT wound onto the winding reel SW2 is then wound onto the delivery reel 22 by the rotation of the delivery reel 22. A cutting device (not shown) is used in the winding process. For each of the multiple delivery reels 22, once the required amount of magnetic tape MT has been wound onto the delivery reel 22, the magnetic tape MT sent from the take-up reel SW2 to the delivery reel 22 is cut by the cutting device.

[0149] The pulse signal generator SW4 generates a pulse signal under the control of the control device SW5 and supplies the generated pulse signal to the servo pattern recording head WH. With the magnetic tape MT 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 according to the pulse signal supplied from the pulse signal generator SW4.

[0150] Figure 17 shows an example of the configuration of the servo pattern recording head WH and an example of the configuration of the pulse signal generator SW4 when the servo pattern recording head WH is observed from the surface 31 side (i.e., the back side of the servo pattern recording head WH) of the magnetic tape MT running on the transport path SW7 (see Figure 16).

[0151] As an example, as shown in Figure 17, the servo pattern recording head WH has a base body WH1 and a plurality of head cores WH2. The base body WH1 is formed in the shape of a rectangular parallelepiped and is arranged to traverse the surface 31 of the magnetic tape MT running on the transport path SW7 along the width direction WD. The surface WH1A of the base body WH1 is a rectangle having a long side WH1Aa and a short side WH1Ab. The longitudinal direction of the base body WH1, i.e., the orientation of the long side WH1Aa, is aligned with the direction WD1 corresponding to the width direction WD (for example, the same direction as the width direction WD). Also, on the surface 31, the base body WH1 traverses the magnetic tape MT in a direction perpendicular to the longitudinal direction LD. That is, the long side WH1Aa traverses the surface 31 of the magnetic tape MT along the width direction WD from one end to the other of the width of the magnetic tape MT.

[0152] Surface WH1A has a sliding surface WH1Ax. The sliding surface WH1Ax is the surface of surface WH1A that overlaps with the surface 31 of the magnetic tape MT when the base body WH1 is traversed along the width direction WD on the surface 31 of the magnetic tape MT (for example, the dotted hatched area shown in Figure 17), and slides against the magnetic tape MT in its running state. The width of the sliding surface WH1Ax shown in Figure 17 (i.e., the length of the short side WH1Ab) is merely an example, and the width of the sliding surface WH1Ax may be several times wider than the example shown in Figure 17.

[0153] Multiple head cores WH2 are incorporated into the base WH1 along direction WD1. The direction in which the multiple head cores WH2 are arranged coincides with the orientation of the long side WH1Aa. That is, the positions of the multiple head cores WH2 are aligned along the longitudinal direction WD.

[0154] A gap pattern G is formed on the head core WH2. The gap pattern G is formed on the surface WH1A (i.e., the surface of the substrate WH1 facing the surface 31 of the magnetic tape MT). The gap pattern G consists of a pair of non-parallel linear regions. A pair of non-parallel linear regions refers to, for example, a linear region with the same geometric characteristics as the magnetization line 60A1a located on the upstream side in the forward direction among the five magnetization lines 60A1a included in the linear magnetization region 60A1 shown in Figure 9, and a linear region with the same geometric characteristics as the magnetization line 60A2a located on the upstream side in the forward direction among the five magnetization lines 60A2a included in the linear magnetization region 60A2 shown in Figure 9.

[0155] Multiple gap patterns G are formed on surface WH1A along direction WD1. The direction in which the multiple gap patterns G are arranged on surface WH1A coincides with the direction of the long side WH1Aa. In other words, on surface WH1A, the multiple gap patterns G are arranged linearly along the long side WH1Aa. Also, on surface WH1A, the positions of the multiple gap patterns G in the longitudinal direction LD are aligned. On surface WH1A, the spacing between adjacent gap patterns G in direction WD1 corresponds to the spacing in the width direction WD between the servo bands SB of the magnetic tape MT (i.e., the servo band pitch).

[0156] A coil (not shown) is wound around the head core WH2, and pulse signals are supplied to the coil. The pulse signals supplied to the coil are pulse signals for servo pattern 58A and pulse signals for servo pattern 58B.

[0157] When the gap pattern G is facing the servo band SB of the magnetic tape MT traveling on the transport path SW7, a pulse signal for servo pattern 58A is supplied to the coil of the head core WH2. A magnetic field is then applied from the gap pattern G to the servo band SB of the magnetic tape MT according to the pulse signal. As a result, servo pattern 58A is recorded on the servo band SB. Similarly, when the gap pattern G is facing the servo band SB of the magnetic tape MT traveling on the transport path SW7, a pulse signal for servo pattern 58B is supplied to the coil of the head core WH2. A magnetic field is then applied from the gap pattern G to the servo band SB of the magnetic tape MT. As a result, servo pattern 58B is recorded on the servo band SB.

[0158] The pulse signals corresponding to each servo pattern 58 (i.e., each servo pattern 58 for each frame 56 (see Figure 9)) are modulated. By modulating the pulse signals, various information is embedded in them. In this case, for example, by modulating the pulse signal for servo pattern 58A, it becomes possible to change the interval between the third and second magnetization lines 60A1a (hereinafter referred to as the "first interval") and the interval between the third and fourth magnetization lines 60A1a (hereinafter referred to as the "second interval") for each servo pattern 58A. By making the first and second intervals different for each servo pattern 58A, it becomes possible to embed at least one bit of information into each servo pattern 58A. This makes it possible to embed various information by combining multiple servo patterns 58.

[0159] Furthermore, the pulse signal may also contain information regarding the position of the longitudinal LD, information identifying the servo band SB, and / or information identifying the manufacturer of the magnetic tape MT, etc. In this case as well, the pulse signal should be modulated according to the information to be embedded.

[0160] In the example shown in Figure 17, head cores WH2A, WH2B, and WH2C are shown as examples of multiple head cores WH2, and gap patterns G1, G2, and G3 are shown as examples of multiple gap patterns G. Gap pattern G1 is formed on head core WH2A. Gap pattern G2 is formed on head core WH2B. Gap pattern G3 is formed on head core WH2C.

[0161] Each of the gap patterns G1 to G3 has the same geometric characteristics as the others. In this embodiment, for example, gap pattern G1 is used to record the servo pattern 58 (see Figure 9) for servo band SB3 (see Figure 9), gap pattern G2 is used to record the servo pattern 58 (see Figure 9) for servo band SB2 (see Figure 9), and gap pattern G3 is used to record the servo pattern 58 (see Figure 9) for servo band SB1 (see Figure 9).

[0162] Gap pattern G1 is a pair of linear regions consisting of linear regions G1A and G1B. Gap pattern G2 is a pair of linear regions consisting of linear regions G2A and G2B. Gap pattern G3 is a pair of linear regions consisting of linear regions G3A and G3B.

[0163] In this embodiment, the pair of linear regions consisting of linear regions G1A and G1B, the pair of linear regions consisting of linear regions G2A and G2B, and the pair of linear regions consisting of linear regions G3A and G3B are examples of "pairs of linear regions" according to the technology of this disclosure. Furthermore, in this embodiment, the linear regions G1A, G2A, and G3A are examples of "first linear regions" according to the technology of this disclosure. Furthermore, in this embodiment, the linear regions G1B, G2B, and G3B are examples of "second linear regions" according to the technology of this disclosure.

[0164] The pulse signal generator SW4 comprises a first pulse signal generator SW4A, a second pulse signal generator SW4B, and a third pulse signal generator SW4C. The first pulse signal generator SW4A is connected to the head core WH2A. The second pulse signal generator SW4B is connected to the head core WH2B. The third pulse signal generator SW4C is connected to the head core WH2C.

[0165] When gap pattern G1 is used for servo band SB3 (see Figure 9), the first pulse signal generator SW4A supplies a pulse signal to head core WH2A. A magnetic field is then applied from gap pattern G1 to servo band SB3 according to the pulse signal, and servo pattern 58 (see Figure 9) is recorded on servo band SB3.

[0166] For example, when the gap pattern G1 is directly facing the servo band SB3 of a magnetic tape MT traveling on the transport path SW7, and a pulse signal for the servo pattern 58A is supplied to the head core WH2A, the servo pattern 58A (see Figure 9) is recorded on the servo band SB3. That is, a linear magnetization region 60A1 (see Figure 9) is recorded on the servo band SB3 by the linear region G1A, and a linear magnetization region 60A2 (see Figure 9) is recorded on the servo band SB3 by the linear region G1B.

[0167] Furthermore, for example, when the gap pattern G1 is directly facing the servo band SB3 of the magnetic tape MT traveling on the transport path SW7, and a pulse signal for the servo pattern 58B is supplied to the head core WH2A, the servo pattern 58B (see Figure 9) is recorded on the servo band SB3. That is, a linear magnetization region 60B1 (see Figure 9) is recorded on the servo band SB3 by the linear region G1A, and a linear magnetization region 60B2 (see Figure 9) is recorded on the servo band SB3 by the linear region G1B.

[0168] When gap pattern G2 is used for servo band SB2 (see Figure 9), the second pulse signal generator SW4B supplies a pulse signal to head core WH2B. According to the pulse signal, a magnetic field is applied from gap pattern G2 to servo band SB2, and servo pattern 58 is recorded in servo band SB2.

[0169] For example, when the gap pattern G2 is directly facing the servo band SB2 of a magnetic tape MT traveling on the transport path SW7, and a pulse signal for the servo pattern 58A is supplied to the head core WH2B, the servo pattern 58A (see Figure 9) is recorded on the servo band SB2. That is, a linear magnetization region 60A1 is recorded on the servo band SB2 by the linear region G2A, and a linear magnetization region 60A2 is recorded on the servo band SB2 by the linear region G2B.

[0170] Furthermore, for example, when the gap pattern G2 is directly facing the servo band SB2 of the magnetic tape MT traveling on the transport path SW7, and a pulse signal for the servo pattern 58B is supplied to the head core WH2B, the servo pattern 58B is recorded on the servo band SB2. That is, a linear magnetization region 60B1 is recorded on the servo band SB2 by the linear region G2A, and a linear magnetization region 60B2 is recorded on the servo band SB2 by the linear region G2B.

[0171] When gap pattern G3 is used for servo band SB1 (see Figure 9), the third pulse signal generator SW4C supplies a pulse signal to the head core WH2C. A magnetic field is then applied from gap pattern G3 to servo band SB1 according to the pulse signal, and servo pattern 58 is recorded on servo band SB1.

[0172] For example, when a pulse signal for servo pattern 58A is supplied to the head core WH2C while the gap pattern G3 is facing the servo band SB1 of a magnetic tape MT traveling on the transport path SW7, the servo pattern 58A is recorded on the servo band SB1. That is, a linear magnetization region 60A1 is recorded on the servo band SB1 by the linear region G3A, and a linear magnetization region 60A2 is recorded on the servo band SB1 by the linear region G3B.

[0173] Furthermore, for example, when the gap pattern G3 is directly facing the servo band SB1 of the magnetic tape MT traveling on the transport path SW7, and a pulse signal for the servo pattern 58B is supplied to the head core WH2C, the servo pattern 58B is recorded on the servo band SB1. That is, a linear magnetization region 60B1 is recorded on the servo band SB1 by the linear region G3A, and a linear magnetization region 60B2 is recorded on the servo band SB1 by the linear region G3B.

[0174] As an example, as shown in Figure 18, in gap pattern G1, linear regions G1A and G1B are tilted in directions opposite to the line along direction WD1, i.e., the virtual line C1. In other words, linear region G1A is tilted in one direction with respect to the virtual line C1 (for example, clockwise when viewed from the front side of the paper in Figure 18). On the other hand, linear region G1B is tilted in the other direction with respect to the virtual line C1 (for example, counterclockwise when viewed from the front side of the paper in Figure 18). Furthermore, the angle of inclination of linear region G1A with respect to the virtual line C1 is steeper than that of linear region G1B. Here, "steep" means, for example, that the angle of linear region G1A with respect to the virtual line C1 is smaller than the angle of linear region G1B with respect to the virtual line C1. Also, the positions of both ends of linear region G1A and the positions of both ends of linear region G1B are aligned in direction WD1. In addition, the total length of linear region G1A is shorter than the total length of linear region G1B.

[0175] In gap pattern G2, linear regions G2A and G2B are tilted in opposite directions with respect to the virtual line C1. In other words, linear region G2A is tilted in one direction with respect to the virtual line C1 (for example, clockwise when viewed from the front side of the paper in Figure 18). On the other hand, linear region G2B is tilted in the other direction with respect to the virtual line C1 (for example, counterclockwise when viewed from the front side of the paper in Figure 18). Furthermore, the angle of inclination of linear region G2A with respect to the virtual line C1 is steeper than that of linear region G2B. Here, "steep" means, for example, that the angle of linear region G2A with respect to the virtual line C1 is smaller than the angle of linear region G2B with respect to the virtual line C1. Also, the positions of both ends of linear region G2A and the positions of both ends of linear region G2B are aligned in direction WD1. In addition, the total length of linear region G2A is shorter than the total length of linear region G2B.

[0176] In gap pattern G3, linear regions G3A and G3B are tilted in opposite directions with respect to the virtual line C1. In other words, linear region G3A is tilted in one direction with respect to the virtual line C1 (for example, clockwise when viewed from the front side of the paper in Figure 18). On the other hand, linear region G3B is tilted in the other direction with respect to the virtual line C1 (for example, counterclockwise when viewed from the front side of the paper in Figure 18). Furthermore, the angle of inclination of linear region G3A with respect to the virtual line C1 is steeper than that of linear region G3B. Here, "steep" means, for example, that the angle of linear region G3A with respect to the virtual line C1 is smaller than the angle of linear region G3B with respect to the virtual line C1. Also, the positions of both ends of linear region G3A and the positions of both ends of linear region G3B are aligned in direction WD1. In addition, the total length of linear region G3A is shorter than the total length of linear region G3B.

[0177] On surface WH1A, the longer side WH1Aa is longer than the width of the magnetic tape MT. The shorter side WH1Ab is long enough to accommodate all of the gap patterns G1, G2, and G3. The substrate WH1 is positioned on the magnetic tape MT in a manner in which the orientation of the longer side WH1Aa is perpendicular to the longitudinal direction LD. That is, the substrate WH1 is positioned on the surface 31 side of the magnetic tape MT with the multiple gap patterns G and the surface 31 facing each other, and in a manner in which the orientation of the longer side WH1Aa is perpendicular to the longitudinal direction LD.

[0178] The pulse signals used between gap patterns G1, G2, and G3 (i.e., the pulse signals supplied from the first pulse signal generator SW4A (see Figure 17) to the head core WH2A, the pulse signals supplied from the second pulse signal generator SW4B (see Figure 17) to the head core WH2B, and the pulse signals supplied from the third pulse signal generator SW4C (see Figure 17) to the head core WH2C, as shown in Figure 17) are out of phase.

[0179] Specifically, the pulse signal generator SW4 (see Figure 17) supplies pulse signals to each of the gap patterns G1, G2, and G3, delayed by a predetermined time, from one side in the direction in which the gap patterns G1, G2, and G3 are arranged to the other side. Here, one side refers to the side of gap pattern G3, and the other side refers to the side of gap pattern G1. In the example shown in Figure 18, a pulse signal is first supplied to gap pattern G3, then a pulse signal is supplied to gap pattern G2 after a predetermined time delay, and then a pulse signal is supplied to gap pattern G1 after a predetermined time delay.

[0180] The default time is a predetermined time determined in accordance with the default interval described above (i.e., the default interval calculated from formula (1)) and the travel speed of the magnetic tape MT traveling along the transport path SW7. For example, it is a fixed value derived in advance through actual machine testing and / or computer simulation to achieve the default interval.

[0181] The default time may be a variable value that changes according to various conditions. In this case, for example, the default time is calculated from a formula in which the default interval is the first independent variable, the travel speed of the magnetic tape MT traveling along the transport path SW7 is the second independent variable, and the default time is the dependent variable. The default interval used as the first independent variable is, for example, the interval in the longitudinal direction LD of a pair of frames 56 that are in a corresponding relationship between adjacent servo bands SB in the width direction WD, as specified by the user of the servo writer SW. The travel speed used as the second independent variable is the travel speed specified by the user of the servo writer SW, or the travel speed measured by a sensor (not shown).

[0182] In the servo pattern recording process, the magnetic tape MT travels along the transport path SW7 at a constant speed with the position of gap pattern G1 corresponding to the position of servo band SB3, the position of gap pattern G2 corresponding to the position of servo band SB2, and the position of gap pattern G3 corresponding to the position of servo band SB1. In this state, pulse signals for servo pattern 58A and pulse signals for servo pattern 58B are alternately supplied to head cores WH2A, WH2B, and WH2C.

[0183] When pulse signals for servo pattern 58A are supplied to head cores WH2A, WH2B, and WH2C with a shifted phase, servo pattern 58A is recorded on servo bands SB3, SB2, and SB1 with a predetermined shift in the longitudinal direction LD. Similarly, when pulse signals for servo pattern 58B are supplied to head cores WH2A, WH2B, and WH2C with a shifted phase, servo pattern 58B is recorded on servo bands SB3, SB2, and SB1 with a predetermined shift in the longitudinal direction LD.

[0184] Here, the geometric properties of the gap pattern G on the surface WH1A will be explained with reference to Figure 19.

[0185] As an example, as shown in Figure 19, the geometric properties on the surface WH1A of the gap pattern G can be represented using a pair of virtual linear regions 68. The pair of virtual linear regions 68 consists of a virtual linear region 68A and a virtual linear region 68B. In this embodiment, the pair of virtual linear regions 68 is an example of a "pair of virtual linear regions" relating to the technology of this disclosure, where virtual linear region 68A is an example of "one virtual linear region" relating to the technology of this disclosure, and virtual linear region 68B is an example of "the other virtual linear region" relating to the technology of this disclosure.

[0186] The virtual linear region pair 68 is a hypothetical linear region pair having the same geometric properties as the gap pattern G shown in Figure 18. The virtual linear region pair 68 is a hypothetical linear region pair used for convenience to explain the geometric properties on the surface WH1A of the gap pattern G, and is not an actual linear region pair.

[0187] In this embodiment, for example, the virtual linear region 68A has the same geometric characteristics as the linear region G1A shown in Figure 18, and the virtual linear region 68B has the same geometric characteristics as the linear region G1B shown in Figure 18.

[0188] A center O2 is provided in the virtual linear region pair 68. For example, center O2 is the center of the line segment L2 that connects the center of virtual linear region 68A and the center of virtual linear region 68B.

[0189] The virtual linear regions 68A and 68B are tilted symmetrically with respect to the virtual line C1. When the entire pair of virtual linear regions 68 is tilted with respect to the virtual line C1 by tilting the axis of symmetry SA2 of the virtual linear regions 68A and 68B by an angle b (for example, 10 degrees) with respect to the virtual line C1, using the center O2 as the axis of rotation, a comparison is made between the pair of virtual linear regions 68 and the pair of virtual linear regions 62 shown in Figure 10. The pair of virtual linear regions 68 has both a deficiency and an unnecessary portion. Here, the deficiency refers to the portion that is insufficient for the servo pattern recording head WH to record the servo pattern 58 on the magnetic tape MT, and the unnecessary portion refers to the portion that is unnecessary for the servo pattern recording head WH to record the servo pattern 58 on the magnetic tape MT. The example shown in Figure 19 illustrates how the virtual linear region 68B has both a deficiency and an unnecessary portion.

[0190] Therefore, by supplementing the missing parts and removing the unnecessary parts, the positions of both ends of the virtual linear region 68A and the positions of both ends of the virtual linear region 68B are aligned with respect to direction WD1.

[0191] The geometric properties of the virtual linear region pair 68 obtained in this way (i.e., the geometric properties of the virtual gap pattern) correspond to the geometric properties of the actual gap pattern G. That is, on the surface WH1A (see Figure 18), a gap pattern G is formed with geometric properties corresponding to the geometric properties of the virtual linear region pair 68 obtained by aligning the positions of both ends of the virtual linear region 68A with the positions of both ends of the virtual linear region 68B in direction WD1.

[0192] Next, the operation of the magnetic tape system 10 will be explained.

[0193] The magnetic tape cartridge 12 contains the magnetic tape MT shown in Figure 9 (see Figures 9 and 11). The magnetic tape cartridge 12 is loaded into the magnetic tape drive 14. When magnetic processing is performed on the magnetic tape MT by the magnetic element unit 42 (see Figures 3 and 15) in the magnetic tape drive 14, the magnetic tape MT is pulled out from the magnetic tape cartridge 12, and the servo pattern 58 in the servo band SB is read by the servo reading element SR of the magnetic head 28.

[0194] As shown in Figures 9 and 10, the linear magnetization regions 60A1 and 60A2 included in the servo pattern 58A recorded in the servo band SB of the magnetic tape MT are tilted in directions opposite to the virtual straight line C1. On the other hand, as shown in Figure 13, the magnetic head 28 on the magnetic tape MT is also tilted by an angle β towards the upstream side in the forward direction (i.e., an angle β counterclockwise when viewed from the front side of the paper in Figure 13). In this state, when the servo pattern 58A is read by the servo reading element SR, the angle between the linear magnetization region 60A1 and the servo reading element SR becomes close to the angle between the linear magnetization region 60A2 and the servo reading element SR. As a result, the variation in the servo signal due to azimuth loss becomes less than the variation that occurs between the servo signal originating from the linear magnetization region 54A1 included in the conventionally known servo pattern 52A and the servo signal originating from the linear magnetization region 54A2 included in the conventionally known servo pattern 52A.

[0195] As a result, the variation between the servo signal originating from linear magnetization region 60A1 and the servo signal originating from linear magnetization region 60A2 is smaller than the variation between the servo signal originating from linear magnetization region 54A1 and the servo signal originating from linear magnetization region 54A2 included in the conventionally known servo pattern 52A, and a more reliable servo signal can be obtained than the servo signal obtained from the conventionally known servo pattern 52A (hereinafter, this effect will also be referred to as the "first effect"). Furthermore, as shown in Figure 13, when the servo pattern 58B is read by the servo reading element SR with the magnetic head 28 tilted at an angle β towards the upstream side in the forward direction on the magnetic tape MT (i.e., an angle β counterclockwise when viewed from the front side of the paper in Figure 13), the same effect as the first effect (hereinafter, this effect will also be referred to as the "second effect") can be obtained.

[0196] By the way, 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 reading element SR may read one end of the linear magnetization region 60A1 but not one end of the linear magnetization region 60A2, or the servo reading element SR may read the other end of the linear magnetization region 60A1 but not the other end of the linear magnetization region 60A2.

[0197] Therefore, in the magnetic tape MT according to this embodiment, the positions of both ends of the linear magnetization region 60A1 (i.e., the positions of both ends of each of the five magnetization lines 60A1a) and the positions of both ends of the linear magnetization region 60A2 (i.e., the positions of both ends of each of the five magnetization lines 60A2a) are aligned in the width direction WD within the servo band SB. Consequently, when reading is performed by the servo reading element SR on the servo pattern 58A, the servo reading element SR can read the linear magnetization regions 60A1 and 60A2 without excess or deficiency, compared to the case where 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. As a result, a more reliable servo signal can be obtained compared to the case where 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 (hereinafter, this effect will be referred to as the "third effect"). Furthermore, the same effect as the third effect (hereinafter referred to as the "fourth effect") can be obtained when reading is performed on the servo pattern 58B using the servo reading element SR.

[0198] As shown in Figures 9 and 10, even though the gradient of the linear magnetization region 60A1 with respect to the virtual straight line C1 is steeper than the gradient of the linear magnetization region 60A2 with respect to the virtual straight 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, portions that can be read by the servo reading element SR and portions that cannot be read will occur between the linear magnetization region 60A1 and the linear magnetization region 60A2. Similarly, even if the total length of the linear magnetization region 60B1 is made longer than the total length of the linear magnetization region 60B2, portions that can be read by the servo reading element SR and portions that cannot be read will occur 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 shorter than the total length of the linear magnetization region 60A2, and the total length of the linear magnetization region 60B1 is shorter than the total length of the linear magnetization region 60B2. This allows for accurate reading of linear magnetization regions 60A1 and 60A2 by the servo reading element SR, and accurate reading of linear magnetization regions 60B1 and 60B2 by the servo reading element SR (hereinafter, this effect will be referred to as the "fifth effect").

[0199] Furthermore, in the magnetic tape MT 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. Similarly, 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 the case where each linear magnetization region consists of one magnetization line, the amount of information obtained from the servo pattern 58 can be increased, and as a result, high-precision servo control can be achieved (hereinafter, this effect will be referred to as the "sixth effect").

[0200] Furthermore, in the magnetic tape MT according to this embodiment, the geometric characteristics of the linear magnetization region pair 60A on the magnetic tape MT correspond to the geometric characteristics obtained when the entire virtual linear region pair 62 is tilted with respect to the virtual line C1 by tilting the symmetry axis SA1 of the virtual linear region pair 62 with respect to the virtual line C1, and the positions of both ends of the virtual linear region 62A and the positions of both ends of the virtual linear region 62B are aligned in the width direction WD. Therefore, compared to the case where reading is performed by the servo reading element SR on a servo pattern 52A having conventionally known geometric characteristics, the variation between the servo signal originating from the linear magnetization region 60A1 and the servo signal originating from the linear magnetization region 60A2 can be reduced. As a result, a servo signal with higher reliability can be obtained than the servo signal obtained from a servo pattern 52A having conventionally known geometric characteristics (hereinafter, this effect will be referred to as the "seventh effect").

[0201] 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 linear magnetization region 60A1, and a linear magnetization region 60B2 instead of linear magnetization region 60A2. The linear magnetization region pair 60B configured in this way is also read by the servo reading element SR, just as with the linear magnetization region pair 60A. Therefore, compared to the case where the servo reading element SR reads a servo pattern 52B with conventionally known geometric characteristics, the variation between the servo signal originating from the linear magnetization region 60B1 and the servo signal originating from the linear magnetization region 60B2 can be reduced. As a result, a more reliable servo signal can be obtained than the servo signal obtained from a servo pattern 52B with conventionally known geometric characteristics (hereinafter, this effect will be referred to as the "eighth effect").

[0202] In this embodiment, a pair of corresponding servo patterns 58 between servo bands SB are read by servo reading elements SR1 and SR2 included in the magnetic head 28. Also in this embodiment, the magnetic head 28 is used in a skewed state on the magnetic tape MT (see Figures 13 to 15). If the pair of corresponding servo patterns 58 between servo bands SB were arranged without being shifted by a predetermined interval in the longitudinal direction LD, a time difference would occur between the timing of reading one of the pair of corresponding servo patterns 58 between servo bands SB and the timing of reading the other servo pattern 58. Therefore, in the magnetic tape MT according to this embodiment, the servo patterns 58 between servo bands SB are shifted by a predetermined interval in the longitudinal direction LD between adjacent servo bands SB in the width direction WD. This reduces the time difference between the timing at which a reading is performed on one of the servo patterns 58 in a pair of servo patterns 58 corresponding to adjacent servo bands SB in the width direction WD, compared to the case where a pair of servo patterns 58 corresponding to adjacent servo bands SB are arranged without being shifted by a predetermined interval (hereinafter, this effect will be referred to as the "ninth effect").

[0203] In this embodiment, the servo band SB is divided into multiple frames 56 (see Figures 9 and 11). Each frame 56 is defined based on a pair of servo patterns 58 (i.e., servo patterns 58A and 58B). In this embodiment, a pair of servo patterns 58 included in a pair of frames 56 that correspond to adjacent servo bands SB in the width direction WD is read by servo reading elements SR1 and SR2 included in the magnetic head 28. In this embodiment, the magnetic head 28 is used in a skewed state on the magnetic tape MT (see Figures 13 to 15). If, hypothetically, the pair of servo patterns 58 included in a pair of frames 56 that correspond to adjacent servo bands SB in the width direction WD are arranged without being shifted by a predetermined interval in the longitudinal direction LD, a time difference will occur between the timing of reading one of the servo patterns 58 and the timing of reading the other servo pattern 58. Therefore, in the magnetic tape MT according to this embodiment, a pair of servo patterns 58 included in a pair of frames 56 that correspond to adjacent servo bands SB in the width direction WD are shifted by a predetermined interval in the longitudinal direction LD between adjacent servo bands SB in the width direction WD. As a result, compared to the case where a pair of corresponding frames 56 between adjacent servo bands SB in the width direction WD are arranged without being shifted by a predetermined interval, the time difference between the timing at which a reading is performed on one of the servo patterns 58 included in a pair of frames 56 that correspond to adjacent servo bands SB in the width direction WD and the timing at which a reading is performed on the other servo pattern 58 can be reduced (hereinafter, this effect will be referred to as the "10th effect").

[0204] In this embodiment, as shown in Figure 11, the default interval is defined based on the angle α formed between frames 56 that are not in correspondence with adjacent servo bands SB in the width direction WD and a virtual straight line C1, the servo band pitch, and the total length of the frame 56 in the longitudinal direction. That is, the default interval is defined by equation (1) and calculated from equation (1). Therefore, the default interval can be easily obtained compared to the case where the default interval is defined without using any of the angle α, servo band pitch, and total length of the frame 56 in the longitudinal direction (hereinafter, this effect will be referred to as the "eleventh effect").

[0205] In this embodiment, the servo signal, which is the result of reading the servo pattern 58 by the servo reading element SR, is detected using the autocorrelation coefficient (see Figure 15). This allows for more accurate detection of the servo signal compared to detecting the servo signal using only a method that determines whether or not the signal level exceeds a threshold (hereinafter, this effect will be referred to as the "twelfth effect").

[0206] Next, I will explain the operation of the servowriter switch.

[0207] In the servo writer SW, when recording a servo pattern 58 onto a magnetic tape MT using the servo pattern recording head WH, the magnetic tape MT is sent to the transport path SW7 and driven at a constant speed. At this time, the magnetic tape MT is driven with the position of gap pattern G1 corresponding to the position of servo band SB3, the position of gap pattern G2 corresponding to the position of servo band SB2, and the position of gap pattern G3 corresponding to the position of servo band SB1. In this state, pulse signals for servo pattern 58A and pulse signals for servo pattern 58B are alternately supplied to the head cores WH2A, WH2B, and WH2C of the servo pattern recording head WH.

[0208] Gap pattern G consists of a pair of non-parallel linear regions. The pair of non-parallel linear regions are linear regions with the same geometric characteristics as the magnetization line 60A1a located on the upstream side in the forward direction among the five magnetization lines 60A1a included in the linear magnetization region 60A1 shown in Figure 9, and linear regions with the same geometric characteristics as the magnetization line 60A2a located on the upstream side in the forward direction among the five magnetization lines 60A2a included in the linear magnetization region 60A2 shown in Figure 9. In addition, gap patterns G1, G2, and G3 are offset by a predetermined interval along the direction LD1, which corresponds to the longitudinal direction LD.

[0209] Therefore, when pulse signals for servo pattern 58A are supplied to head core WH2A, head core WH2B, and head core WH2C in the same phase, servo pattern 58A is recorded on servo bands SB3, servo band SB2, and servo band SB1 with a predetermined offset in the longitudinal direction LD. Also, when pulse signals for servo pattern 58B are supplied to head core WH2A, head core WH2B, and head core WH2C in the same phase, servo pattern 58B is recorded on servo bands SB3, servo band SB2, and servo band SB1 with a predetermined offset in the longitudinal direction LD.

[0210] When the servo pattern 58A recorded on the servo band SB of the magnetic tape MT obtained in this way is read by the servo reading element SR included in the magnetic head 28 which is skewed on the magnetic tape MT, the first to twelfth effects are obtained.

[0211] As shown in Figure 20 as a first comparative example, even when using the servo pattern recording head Hα, the servo pattern 58 can be recorded with respect to the servo bands SB3, SB2, and SB1, with a predetermined offset in the longitudinal direction LD. The servo pattern recording head Hα differs from the servo pattern recording head WH in that it has a base Hα1 instead of a base WH1. The base Hα1 is formed in the shape of a rectangular parallelepiped and is arranged to traverse the surface 31 of the magnetic tape MT running on the transport path SW7 along the width direction WD. The surface Hα1A of the base Hα1 is a rectangle with a long side Hα1Aa and a short side Hα1Ab, and the long side Hα1Aa traverses the surface 31 of the magnetic tape MT along the width direction WD.

[0212] The longer side Hα1Aa is longer than the width of the magnetic tape MT. The direction of the longer side H1αAa coincides with the width direction WD, and the substrate Hα1 is positioned on the surface 31 side of the magnetic tape MT with multiple gap patterns G facing the surface 31, and traversing the magnetic tape MT in the width direction WD.

[0213] In the servo pattern recording head Hα, gap patterns G1, G2, and G3 are offset along direction WD1 between adjacent gap patterns G by the predetermined interval described above (i.e., the predetermined interval calculated from formula (1)) in the direction LD1 corresponding to the longitudinal direction LD (for example, the same direction as the longitudinal direction LD). The direction of the short side Hα1Ab coincides with direction LD1, and the length of the short side Hα1Ab is such that all of the gap patterns G1, G2, and G3 are contained within it. That is, the length of the short side Hα1Ab is set to capture at least the amount by which gap patterns G1 to G3 are offset along direction LD1 from gap pattern G1 to gap pattern G3. In the servo pattern recording head Hα configured in this way, multiple servo patterns 58 are recorded for each of the multiple servo bands SB by supplying pulse signals with the same phase to each of the gap patterns G1, G2, and G3 (see Figure 9).

[0214] In contrast, in the servo pattern recording head WH, the gap patterns G1, G2, and G3 are arranged linearly in a direction perpendicular to the direction LD1, and by delaying the pulse signal by a predetermined time, the arrangement of multiple servo patterns 58 shown in Figure 9 can be realized without shifting the gap patterns G1, G2, and G3 in the direction LD1. Since there is no need to shift the gap patterns G1, G2, and G3 in the direction LD1, the short side WH1Ab can be made shorter than the short side Hα1Ab. The fact that the short side WH1Ab is shorter than the short side Hα1Ab means that the area of ​​surface WH1A is smaller than the area of ​​surface Hα1A. As a result, the area in which surface WH1A contacts the surface 31 of the magnetic tape MT (i.e., the area of ​​the sliding surface WH1Ax shown in Figure 17) can be made smaller than the area in which surface Hα1A contacts the surface 31 of the magnetic tape MT shown in Figure 20, so the servo pattern recording head WH can suppress the friction between the magnetic tape MT and surface WH1A compared to the servo pattern recording head Hα. Furthermore, reducing friction contributes to stabilizing the movement of the magnetic tape MT.

[0215] As shown in Figure 21, a second comparative example, even when using the servo pattern recording head Hβ, the servo pattern 58 can be recorded with respect to the servo bands SB3, SB2, and SB1, with a predetermined offset in the longitudinal direction LD. The servo pattern recording head Hβ differs from the servo pattern recording head WH in that it has a base Hβ1 instead of a base WH1. The base Hβ1 is formed in the shape of a rectangular parallelepiped and is positioned to diagonally cross the surface 31 of the magnetic tape MT running on the transport path SW7. The surface Hβ1A of the base Hβ1 is a rectangle with a long side Hβ1Aa and a short side Hβ1Ab, and the long side Hβ1Aa diagonally crosses the surface 31 of the magnetic tape MT.

[0216] In the servo pattern recording head Hβ, gap patterns G1, G2, and G3 are offset in the direction LD1 along the direction WD1 between adjacent gap patterns G by the predetermined interval described above (i.e., the predetermined interval calculated from formula (1)). The short side Hβ1Ab is long enough to accommodate all of gap patterns G1, G2, and G3. In other words, the length of the short side Hβ1Ab is set to be long enough to capture at least the amount by which gap patterns G1 to G3 are offset along the direction LD1 from gap pattern G1 to gap pattern G3.

[0217] In the servo pattern recording head Hβ, the base Hβ1 is positioned so that multiple gap patterns G and the surface 31 face each other on the surface 31 side of the magnetic tape MT, and is tilted along the surface 31 of the magnetic tape MT with respect to a virtual straight line C1 at an angle γ that absorbs a predetermined spacing difference. In the example shown in Figure 21, the extension line C5 of the long side Hβ1Aa is shown to be tilted along the surface 31 of the magnetic tape MT with respect to the virtual straight line C1 at an angle γ. In the servo pattern recording head Hβ configured in this way, multiple servo patterns 58 are recorded for each of the multiple servo bands SB by supplying pulse signals with the same phase to each of the gap patterns G1, G2, and G3 (see Figure 9).

[0218] In contrast, in the servo pattern recording head WH, the gap patterns G1, G2, and G3 are arranged linearly on the surface WH1A in a direction perpendicular to the direction LD1, and by delaying the pulse signal by a predetermined time, the arrangement of multiple servo patterns 58 shown in Figure 9 can be realized without shifting the gap patterns G1, G2, and G3 in the direction LD1. Therefore, in the servo pattern recording head WH, there is no need to tilt the base body WH1 on the surface 31 of the magnetic tape MT. The fact that there is no need to tilt the base body WH1 on the surface 31 of the magnetic tape MT means that the work of tilting the base body WH1 is unnecessary. In addition, the phenomenon of the magnetic tape MT being biased in the width direction WD due to the tilt of the base body WH1 is less likely to occur.

[0219] Furthermore, in the servo writer SW, phase-shifted signals are used as pulse signals between multiple gap patterns G. Pulse signals for servo pattern 58A and pulse signals for servo pattern 58B are alternately supplied to head cores WH2A, WH2B, and WH2C. In the servo writer SW, gap patterns G1, G2, and G3 are shifted by a predetermined interval in the direction LD1. Therefore, by supplying pulse signals for servo pattern 58A to head cores WH2A, WH2B, and WH2C with phase-shifted signals, the servo writer SW can record servo pattern 58A between adjacent servo bands SB in the width direction WD and shifted by a predetermined interval in the longitudinal direction LD for servo bands SB1 to SB3. Furthermore, the servo writer SW supplies pulse signals for the servo pattern 58B to head cores WH2A, WH2B, and WH2C with a shifted phase, thereby enabling the recording of the servo pattern 58B for servo bands SB1 to SB3, with a predetermined shift in the longitudinal direction LD between adjacent servo bands SB in the width direction WD.

[0220] Furthermore, in the servo writer SW, the control device SW5 operates as a position detection unit 30B as shown in Figure 14 to acquire position detection results from the servo pattern reading results, and uses the position detection results to determine whether the servo pattern 58 is correct or incorrect, thereby performing inspection of the servo band SB. The control device SW5 operating as a position detection unit 30B can detect the servo signal with greater accuracy compared to a method that only determines whether the signal level exceeds a threshold, so the servo writer SW can also perform inspection of the servo band SB with greater accuracy.

[0221] In the above embodiment, an example was described in which the servo band SB is divided by a plurality of frames 56 along the longitudinal direction LD, but the technology of this disclosure is not limited thereto. For example, as shown in Figure 22, the servo band SB may be divided by frames 70 along the longitudinal direction LD. The frames 70 are defined by a set of servo patterns 72. A plurality of servo patterns 72 are recorded in the servo band SB along the longitudinal direction LD. The plurality of servo patterns 72 are arranged at regular intervals along the longitudinal direction LD, similar to the plurality of servo patterns 58.

[0222] In the example shown in Figure 22, servo patterns 72A and 72B are shown as an example of a pair of servo patterns 72. Each of servo patterns 72A and 72B is an M-shaped magnetized servo pattern. Servo patterns 72A and 72B are adjacent to each other along the longitudinal direction LD, with servo pattern 72A located on the upstream side in the forward direction and servo pattern 72B located on the downstream side in the forward direction within the frame 70.

[0223] As an example, as shown in Figure 23, the servo pattern 72 consists 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.

[0224] The servo pattern 72A consists of a pair of linear magnetization regions 74A. The pair of linear magnetization regions 74A are arranged adjacent to each other along the longitudinal direction LD.

[0225] In the example shown in Figure 23, linear magnetization regions 74A1 and 74A2 are shown as an example of a linear magnetization region pair 74A. The linear magnetization region pair 74A is configured in the same way as the linear magnetization region pair 60A described in the above embodiment and has the same geometric characteristics as the linear magnetization region pair 60A. That is, linear magnetization region 74A1 is configured in the same way as the linear magnetization region 60A1 described in the above embodiment and has the same geometric characteristics as the linear magnetization region 60A1, and linear magnetization region 74A2 is configured in the same way as the linear magnetization region 60A2 described in the above embodiment and has the same geometric characteristics as the linear magnetization region 60A2.

[0226] The servo pattern 72B consists of a pair of linear magnetization regions 74B. The pair of linear magnetization regions 74B are arranged adjacent to each other along the longitudinal direction LD.

[0227] In the example shown in Figure 23, linear magnetization regions 74B1 and 74B2 are shown as an example of a linear magnetization region pair 74B. The linear magnetization region pair 74B is configured in the same way as the linear magnetization region pair 60B described in the above embodiment and has the same geometric characteristics as the linear magnetization region pair 60B. That is, linear magnetization region 74B1 is configured in the same way as the linear magnetization region 60B1 described in the above embodiment and has the same geometric characteristics as the linear magnetization region 60B1, and linear magnetization region 74B2 is configured in the same way as the linear magnetization region 60B2 described in the above embodiment and has the same geometric characteristics as the linear magnetization region 60B2.

[0228] As an example, as shown in Figure 24, the servo pattern recording head WH used for recording the servo pattern 72 differs from the servo pattern recording head WH described in the above embodiment (i.e., the servo pattern recording head WH used for recording the servo pattern 58) in that it has a gap pattern G4 instead of a gap pattern G1, a gap pattern G5 instead of a gap pattern G2, and a gap pattern G6 instead of a gap pattern G3.

[0229] The gap pattern G4 consists of linear regions G4A, G4B, G4C, and G4D. Linear regions G4A and G4B are used to record one of the pair of linear magnetization regions 74A shown in Figure 23 (for example, the upstream linear magnetization region pair 74A in the forward direction), while linear regions G4C and G4D are used to record the other pair of linear magnetization regions 74A shown in Figure 23 (for example, the downstream linear magnetization region pair 74A in the forward direction). Furthermore, linear regions G4A and G4B are used to record one of the pair of linear magnetization regions 74B shown in Figure 21 (for example, the upstream linear magnetization region 74B in the forward direction), and linear regions G4C and G4D are used to record the other pair of linear magnetization regions 74B shown in Figure 21 (for example, the downstream linear magnetization region 74B in the forward direction).

[0230] The configurations of linear regions G4A and G4B are the same as those of linear regions G1A and G1B. That is, linear regions G4A and G4B have the same geometric properties as linear regions G1A and G1B. The configurations of linear regions G4C and G4D are the same as those of linear regions G4A and G4B. That is, linear regions G4C and G4D have the same geometric properties as linear regions G4A and G4B.

[0231] Gap pattern G5 consists of linear regions G5A, G5B, G5C, and G5D. The configuration of linear regions G5A, G5B, G5C, and G5D is the same as the configuration of linear regions G4A, G4B, G4C, and G4D. That is, linear regions G5A, G5B, G5C, and G5D have the same geometric properties as linear regions G4A, G4B, G4C, and G4D.

[0232] Gap pattern G6 consists of linear regions G6A, G6B, G6C, and G6D. The configuration of linear regions G6A, G6B, G6C, and G6D is the same as that of linear regions G4A, G4B, G4C, and G4D. That is, linear regions G6A, G6B, G6C, and G6D have the same geometric properties as linear regions G4A, G4B, G4C, and G4D.

[0233] The gap patterns G4, G5, and G6 configured in this way are arranged linearly along the long side WH1Aa, similar to the embodiment described above.

[0234] The longer side WH1Aa of surface WH1A is longer than the width of the magnetic tape MT. The shorter side WH1Ab of surface WH1A is long enough to accommodate all of the gap patterns G4, G5, and G6. The direction of the longer side WH1Aa of surface WH1A coincides with the width direction WD, and the direction of the shorter side WH1Ab of surface WH1A coincides with the longitudinal direction LD. The substrate WH1 is positioned on the surface 31 side of the magnetic tape MT with the multiple gap patterns G and surface 31 facing each other, and traversing the magnetic tape MT in the width direction WD.

[0235] The pulse signals used between gap patterns G4, G5, and G6 (i.e., the pulse signals supplied from the first pulse signal generator SW4A to the head core WH2A, the pulse signals supplied from the second pulse signal generator SW4B to the head core WH2B, and the pulse signals supplied from the third pulse signal generator SW4C to the head core WH2C, as shown in Figure 24) are signals that have been delayed by a predetermined amount of time in the order of gap patterns G6, G5, and G4, as described in the above embodiment.

[0236] In the servo pattern recording process, the magnetic tape MT travels along the transport path SW7 at a constant speed with the position of gap pattern G4 corresponding to the position of servo band SB3, the position of gap pattern G5 corresponding to the position of servo band SB2, and the position of gap pattern G6 corresponding to the position of servo band SB1. In this state, pulse signals for servo pattern 72A and pulse signals for servo pattern 72B are alternately supplied to head cores WH2A, WH2B, and WH2C.

[0237] Here, when pulse signals for servo pattern 72A are supplied to head core WH2A, head core WH2B, and head core WH2C at the same timing as described in the above embodiment, servo pattern 72A is recorded on servo bands SB3, servo band SB2, and servo band SB1 with a predetermined interval shift in the longitudinal direction LD. Also, when pulse signals for servo pattern 72B are supplied to head core WH2A, head core WH2B, and head core WH2C at the same timing as described in the above embodiment, servo pattern 72B is recorded on servo bands SB3, servo band SB2, and servo band SB1 with a predetermined interval shift in the longitudinal direction LD.

[0238] In the example shown in Figure 22, the servo band SB is divided into multiple frames 70 along the longitudinal direction LD, but the technology of this disclosure is not limited to this. For example, as shown in Figure 25, the servo band SB may be divided into frames 76 along the longitudinal direction LD. The frames 76 are defined by a set of servo patterns 78. Multiple servo patterns 78 are recorded in the servo band SB along the longitudinal direction LD. The multiple servo patterns 78 are arranged at regular intervals along the longitudinal direction LD, similar to the multiple servo patterns 72 (see Figure 22).

[0239] In the example shown in Figure 25, servo patterns 78A and 78B are shown as an example of a pair of servo patterns 78. Each of servo patterns 78A and 78B is an N-shaped magnetized servo pattern. Servo patterns 78A and 78B are adjacent to each other along the longitudinal direction LD, with servo pattern 78A located on the upstream side in the forward direction and servo pattern 78B located on the downstream side in the forward direction within the frame 76.

[0240] As an example, as shown in Figure 26, the servo pattern 78 consists of a linear magnetization region group 80. The linear magnetization region group 80 is classified into linear magnetization region group 80A and linear magnetization region group 80B.

[0241] The servo pattern 78A consists of a linear magnetization region group 80A. The linear magnetization region group 80A consists 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. The linear magnetization regions 80A1, 80A2, and 80A3 are arranged in the order of linear magnetization regions 80A1, 80A2, and 80A3 from the upstream side in the forward direction.

[0242] Linear magnetization regions 80A1 and 80A2 are configured similarly to linear magnetization region pair 74A shown in Figure 23 and have the same geometric characteristics as linear magnetization region pair 74A. That is, linear magnetization region 80A1 is configured similarly to linear magnetization region 74A1 shown in Figure 23 and has the same geometric characteristics as linear magnetization region 74A1, and linear magnetization region 80A2 is configured similarly to linear magnetization region 74A2 shown in Figure 23 and has the same geometric characteristics as linear magnetization region 74A2. Furthermore, linear magnetization region 80A3 is configured similarly to linear magnetization region 80A1 and has the same geometric characteristics as linear magnetization region 80A1.

[0243] In the example shown in Figure 26, linear magnetization regions 80A1 and 80A2 are examples of a "pair of linear magnetization regions" relating to the technology of this disclosure. In this case, linear magnetization region 80A1 is an example of a "first linear magnetization region" relating to the technology of this disclosure, and linear magnetization region 80A2 is an example of a "second linear magnetization region" relating to the technology of this disclosure. Similarly, linear magnetization regions 80A2 and 80A3 are also examples of a "pair of linear magnetization regions" relating to the technology of this disclosure. In this case, linear magnetization region 80A3 is an example of a "first linear magnetization region" relating to the technology of this disclosure, and linear magnetization region 80A2 is an example of a "second linear magnetization region" relating to the technology of this disclosure.

[0244] The servo pattern 78B consists of a linear magnetization region group 80B. The linear magnetization region group 80B consists 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. The linear magnetization regions 80B1, 80B2, and 80B3 are arranged in the order of linear magnetization regions 80B1, 80B2, and 80B3 from the upstream side in the forward direction.

[0245] Linear magnetization regions 80B1 and 80B2 are configured similarly to linear magnetization region pair 74B shown in Figure 23 and have the same geometric characteristics as linear magnetization region pair 74BB. That is, linear magnetization region 80B1 is configured similarly to linear magnetization region 74B1 shown in Figure 23 and has the same geometric characteristics as linear magnetization region 74B1, and linear magnetization region 80B2 is configured similarly to linear magnetization region 74B2 shown in Figure 23 and has the same geometric characteristics as linear magnetization region 74B2. Furthermore, linear magnetization region 80B3 is configured similarly to linear magnetization region 80B1 and has the same geometric characteristics as linear magnetization region 80B1.

[0246] In the example shown in Figure 26, linear magnetization regions 80B1 and 80B2 are examples of a "pair of linear magnetization regions" relating to the technology of this disclosure. In this case, linear magnetization region 80B1 is an example of a "first linear magnetization region" relating to the technology of this disclosure, and linear magnetization region 80B2 is an example of a "second linear magnetization region" relating to the technology of this disclosure. Similarly, linear magnetization regions 80B2 and 80B3 are also examples of a "pair of linear magnetization regions" relating to the technology of this disclosure. In this case, linear magnetization region 80B3 is an example of a "first linear magnetization region" relating to the technology of this disclosure, and linear magnetization region 80B2 is an example of a "second linear magnetization region" relating to the technology of this disclosure.

[0247] As an example, as shown in Figure 27, the servo pattern recording head WH used to record the servo pattern 78 differs from the servo pattern recording head WH shown in Figure 24 (i.e., the servo pattern recording head WH used to record the servo pattern 72) in that it has a gap pattern G7 instead of a gap pattern G4, a gap pattern G8 instead of a gap pattern G5, and a gap pattern G9 instead of a gap pattern G6.

[0248] The gap pattern G7 consists of linear regions G7A, G7B, and G7C. Linear region G7A is used to record linear magnetization regions 80A1 and 80B1 (see Figure 26) within servo band SB3 (see Figure 25), linear region G7B is used to record linear magnetization regions 80A2 and 80B2 (see Figure 26) within servo band SB3 (see Figure 25), and linear region G7C is used to record linear magnetization regions 80A3 and 80B3 (see Figure 26) within servo band SB3 (see Figure 25).

[0249] The configurations of linear regions G7A, G7B, and G7C are the same as those of linear regions G4A, G4B, and G4C shown in Figure 24. That is, linear regions G7A, G7B, and G7C have the same geometric properties as linear regions G4A, G4B, and G4C.

[0250] The gap pattern G8 consists of linear regions G8A, G8B, and G8C. Linear region G8A is used to record linear magnetization regions 80A1 and 80B1 (see Figure 26) within servo band SB2 (see Figure 25), linear region G8B is used to record linear magnetization regions 80A2 and 80B2 (see Figure 26) within servo band SB2 (see Figure 25), and linear region G8C is used to record linear magnetization regions 80A3 and 80B3 (see Figure 26) within servo band SB2 (see Figure 25).

[0251] The configurations of linear regions G8A, G8B, and G8C are the same as those of linear regions G5A, G5B, and G5C shown in Figure 24. That is, linear regions G8A, G8B, and G8C have the same geometric properties as linear regions G5A, G5B, and G5C.

[0252] The gap pattern G9 consists of linear regions G9A, G9B, and G9C. Linear region G9A is used to record linear magnetization regions 80A1 and 80B1 (see Figure 26) within servo band SB1 (see Figure 25), linear region G9B is used to record linear magnetization regions 80A2 and 80B2 (see Figure 26) within servo band SB1 (see Figure 25), and linear region G9C is used to record linear magnetization regions 80A3 and 80B3 (see Figure 26) within servo band SB1 (see Figure 25).

[0253] The configurations of linear regions G9A, G9B, and G9C are the same as those of linear regions G6A, G6B, and G6C shown in Figure 24. That is, linear regions G9A, G9B, and G9C have the same geometric properties as linear regions G6A, G6B, and G6C.

[0254] The gap patterns G7, G8, and G9 configured in this way are arranged linearly along the long side WH1Aa, similar to the embodiment described above.

[0255] The longer side WH1Aa of surface WH1A is longer than the width of the magnetic tape MT. The shorter side WH1Ab of surface WH1A is long enough to accommodate all of the gap patterns G7, G8, and G9. The direction of the longer side WH1Aa of surface WH1A coincides with the width direction WD, and the direction of the shorter side WH1Ab of surface WH1A coincides with the longitudinal direction LD. The substrate WH1 is positioned on the surface 31 side of the magnetic tape MT with multiple gap patterns G and surface 31 facing each other, and traversing the magnetic tape MT in the width direction WD.

[0256] The pulse signals used between gap patterns G7, G8, and G9 (i.e., the pulse signals supplied from the first pulse signal generator SW4A to the head core WH2A, the pulse signals supplied from the second pulse signal generator SW4B to the head core WH2B, and the pulse signals supplied from the third pulse signal generator SW4C to the head core WH2C, as shown in Figure 24) are signals that have been delayed by a predetermined amount of time in the order of gap patterns G6, G5, and G4, as described in the above embodiment.

[0257] In the servo pattern recording process, the magnetic tape MT travels along the transport path SW7 at a constant speed with the position of gap pattern G7 corresponding to the position of servo band SB3, the position of gap pattern G8 corresponding to the position of servo band SB2, and the position of gap pattern G9 corresponding to the position of servo band SB1. In this state, pulse signals for servo pattern 80A and pulse signals for servo pattern 80B are alternately supplied to head cores WH2A, WH2B, and WH2C.

[0258] Here, when pulse signals for servo pattern 80A are supplied to head core WH2A, head core WH2B, and head core WH2C at the same timing as described in the above embodiment, servo pattern 80A is recorded in servo bands SB3, servo band SB2, and servo band SB1 with a predetermined interval shift in the longitudinal direction LD. Also, when pulse signals for servo pattern 80B are supplied to head core WH2A, head core WH2B, and head core WH2C at the same timing as described in the above embodiment, servo pattern 80B is recorded in servo bands SB3, servo band SB2, and servo band SB1 with a predetermined interval shift in the longitudinal direction LD.

[0259] In the embodiments described above, an example was given in which the default interval is defined based on an angle α, a servo band pitch, and a frame length. However, the technology of this disclosure is not limited thereto, and the default interval may be defined without using the frame length. For example, as shown in Figure 28, the default interval is defined based on the angle α formed by the corresponding frames 56 (line segment L3 in the example shown in Figure 28) and the virtual line C1 between adjacent servo bands SB in the width direction WD, and the pitch between adjacent servo bands SB in the width direction WD (i.e., the servo band pitch). In this case, for example, the default interval is calculated from the following formula (2).

[0260] (Default interval) = (Servo band pitch) × tanα····(2)

[0261] Thus, formula (2) does not include the frame length. This means that the default interval can be calculated without considering the frame length. Therefore, with this configuration, the default interval can be calculated more easily compared to calculating it from formula (1).

[0262] In the above embodiment, a magnetic tape system 10 in which a magnetic tape cartridge 12 can be inserted into and removed from a magnetic tape drive 14 is illustrated, but the technology of this disclosure is not limited thereto. For example, the technology of this disclosure also applies to a magnetic tape system in which at least one magnetic tape cartridge 12 is pre-loaded into a magnetic tape drive 14 (i.e., a magnetic tape system in which at least one magnetic tape cartridge 12 and a magnetic tape drive 14 are pre-integrated).

[0263] In the above embodiment, a single magnetic head 28 is illustrated, but the technology of this disclosure is not limited thereto. For example, multiple magnetic heads 28 may be arranged on the magnetic tape MT. For example, a reading magnetic head 28 and at least one writing magnetic head 28 may be arranged on the magnetic tape MT. The reading magnetic head 28 may be used to verify the data recorded in the data band DB by the writing magnetic head 28. Alternatively, a single magnetic head equipped with a reading magnetic element unit 42 and at least one writing magnetic element unit 42 may be arranged on the magnetic tape MT.

[0264] The descriptions and illustrations presented above are detailed explanations of the technical aspects of this disclosure and are merely examples of the technical aspects. For example, the above descriptions of the structure, function, operation, and effect are examples of the structure, function, operation, and effect of the technical aspects of this disclosure. Therefore, it goes without saying that you may delete unnecessary parts, add new elements, or replace elements in the descriptions and illustrations presented above, as long as you do not deviate from the essence of the technical aspects of this disclosure. Furthermore, in order to avoid confusion and facilitate understanding of the technical aspects of this disclosure, explanations of common technical knowledge and the like that do not require special explanation to enable the implementation of the technical aspects of this disclosure have been omitted from the descriptions and illustrations presented above.

[0265] In this specification, "A and / or B" is synonymous with "at least one of A and B." That is, "A and / or B" means that it may be A alone, or B alone, or a combination of A and B. Furthermore, in this specification, the same concept as "A and / or B" applies when expressing three or more things linked by "and / or."

[0266] All documents, patent applications, and technical standards described herein are incorporated by reference to the same extent as if each individual document, patent application, and technical standard were specifically and individually noted to be incorporated by reference.

[0267] (Supplementary Note 1) A base body, and a servo pattern recording head comprising a plurality of gap patterns formed on a surface of said base body, wherein said plurality of gap patterns are formed on said surface along a direction corresponding to a width direction of a magnetic tape, record a plurality of servo patterns in said width direction by applying a magnetic field to said magnetic tape in accordance with a supplied pulse signal, said gap patterns are at least one pair of linear regions, a first linear region that is one linear region of said pair of linear regions, and a second linear region that is the other linear region of said pair of linear regions are inclined in opposite directions with respect to a first imaginary straight line along the direction corresponding to said width direction on said surface, said first linear region has a steeper inclination angle with respect to said first imaginary straight line than said second linear region, positions of both ends of said first linear region and positions of both ends of said second linear region are aligned in the direction corresponding to the width direction of said magnetic tape, on said surface, positions of said plurality of gap patterns in a longitudinal direction of said magnetic tape are aligned, a pulse signal generator supplies, to each of said plurality of gap patterns, said pulse signal delayed by a predetermined time from one side to the other side in a direction in which said plurality of gap patterns are arranged A servo pattern recording head. Description of Reference Signs

[0268] 10 Magnetic tape system 12 Magnetic tape cartridge 14 Magnetic tape drive 16 Case 16A Right wall 16B Opening 18 Upper case 20 Lower case 22, SW1 Feed reel 22A Reel Hub 22B1 Upper flange 22B2 Lower flange 24 cartridge memory 24B,33 Back side 26 Conveying device 28 Magnetic Heads 29A magnetic layer 29B Base film 29C Backcoat Layer 30, SW5 Control Unit 30A Control Unit 30B Position detection unit 30B1 First position detection unit 30B2 Second position detection unit 31,Hα1A,Hβ1A,WH1A surface 32 storage 34 UI devices 35 Communication Interfaces 36. Sending motor 37 External device 38, SW2 Winding Reel 40 Rewinding motor 42 Magnetic element unit 44 holder 46. ​​Contactless reading and writing devices 48 Moving mechanism 48A Moving Actuator 49 Tilt mechanism 49A Tilt Actuator 50, 56, 70, 76 frames 52, 52A, 52B, 58, 58A, 58B, 72, 72A, 72B, 78, 78A, 78B Servo Pattern Linear magnetization region pairs: 54, 54A, 54B, 60, 60A, 60B, 74, 74A, 74B 54A1,54A2,54B1,54B2,60A1,60A2,60B1,60B2,74A1,74A2,74B1,74B2,80A1,80A2,80A3 Linear magnetization region 54A1a,54A2a,54B1a,54B2a,60A1a,60A2a,60B1a,60B2a Magnetization straight line 62 Virtual Linear Region Pair 62A, 62B Virtual Linear Region 62A1, 62B1 Straight Line 66 Ideal Waveform Signal 68 Virtual Straight Line Region Pair 68A, 68B Virtual Straight Line Region 80, 80A, 80B Linear Magnetized Region Group A, B, C Arrows a, b, α, β, γ Angles C1, C2, C3, C4 Virtual Straight Line C5 Extended Line DB, DB1, DB2 Data Band DRW Data Read / Write Element G, G1, G2, G3, G4, G5, G6, G7, G8, G9 Gap Pattern G1A, G1B, G2A, G2B, G3A, G3B, G4A, G4B, G4C, G4D, G5A, G5B, G5C, G5D, G6A, G6B, G6C, G6D, G7A, G7B, G7C, G8A, G8B, G8C, G9A, G9B, G9C Straight Line Region GR Guide Roller H, WH Servo Pattern Recording Head Hα1, Hβ1, WH1 Base Body Hα1Aa, Hβ1Aa, WH1Aa Long Side Hα1Ab, HβAb, WH1Ab Short Side L0, L1, L2 Line Segment LD Longitudinal Direction LD1, WD1 Direction MF Magnetic Field MT, MT0 Magnetic Tape O1, O2 Center RA Rotation Shaft SA1, SA2 Symmetry Axis SB, SB1, SB2, SB3 Servo Band SR, SR1, SR2 Servo Reading Element SW Servo Writer SW3 Driving Device SW4 Pulse Signal Generator SW4A First Pulse Signal Generator SW4B Second Pulse Signal Generator SW4C Third Pulse Signal Generator SW6 Guide SW7 Conveyor Route VH Verify Head WD width direction WH1 base WH1Aa Long side WH1Ab Short side WH1Ax sliding surface WH2, WH2A, WH2B, WH2C Head Core

Claims

1. A pulse signal generator, A servo pattern recording device comprising a servo pattern recording head, The pulse signal generator generates a pulse signal, The servo pattern recording head has a base and a plurality of gap patterns formed on the surface of the base, and records a plurality of servo patterns in the width direction of the magnetic tape by applying a magnetic field to the magnetic tape from the plurality of gap patterns in accordance with the pulse signal. The plurality of gap patterns are formed on the surface along the direction corresponding to the width direction, The gap pattern is at least one pair of linear regions, The first linear region, which is one of the pair of linear regions, and the second linear region, which is the other of the pair of linear regions, are tilted in directions opposite to the first virtual line along the direction corresponding to the width direction on the surface. The first linear region has a steeper angle of inclination with respect to the first virtual line than the second linear region. The positions of both ends of the first linear region and the positions of both ends of the second linear region are aligned in a direction corresponding to the width direction of the magnetic tape. On the aforementioned surface, the plurality of gap patterns are aligned in the longitudinal direction of the magnetic tape. The pulse signal generator supplies the pulse signal to each of the plurality of gap patterns with a predetermined delay from one side in the direction in which the plurality of gap patterns are arranged to the other side. The magnetic tape has a plurality of servo bands formed along the width direction, The servo patterns corresponding between the servo bands are adjacent to the servos in the width direction. The bands are offset at predetermined intervals in the longitudinal direction of the magnetic tape. The servo band is divided into frames defined based on at least one set of the servo patterns, The aforementioned default time is determined according to the aforementioned default interval, The predetermined interval is defined based on the angle between the frames that are not in correspondence with adjacent servo bands in the width direction and the first virtual line, the pitch between adjacent servo bands in the width direction, and the total length of the frame in the longitudinal direction. Servo pattern recording device.

2. A magnetic tape on which a plurality of servo patterns are recorded by the servo pattern recording device described in Claim 1.

3. The magnetic tape according to Claim 2, A case containing the aforementioned magnetic tape, A magnetic tape cartridge equipped with [a specific feature / feature].

4. A travel mechanism for traveling the magnetic tape described in Claim 2 along a predetermined path, A magnetic tape drive comprising: a magnetic head having a plurality of servo reading elements that read the servo pattern on the predetermined path while the magnetic tape is being driven by the aforementioned travel mechanism, The plurality of servo reading elements are arranged along the longitudinal direction of the magnetic head, The magnetic head is positioned such that a second imaginary straight line along the longitudinal direction of the magnetic head is inclined with respect to the direction in which the magnetic tape travels. Magnetic tape drive.

5. The magnetic tape according to Claim 2, A magnetic tape system comprising: a magnetic tape drive equipped with a magnetic head having a plurality of servo reading elements for reading the servo pattern on the predetermined path while the magnetic tape is running along the predetermined path, The plurality of servo reading elements are arranged along the longitudinal direction of the magnetic head, The magnetic head is positioned such that a third virtual straight line along the longitudinal direction of the magnetic head is inclined with respect to the direction in which the magnetic tape travels. Magnetic tape system.

6. A detection device equipped with a processor, The processor calculates the autocorrelation coefficient for the servo signal, which is the result of reading the servo pattern from the magnetic tape described in claim 2 by the servo reading element, The servo signal is detected based on the calculated autocorrelation coefficient. Detection device.

7. A servo pattern recording method, To generate a pulse signal, The servo pattern recording head, having a substrate and a plurality of gap patterns formed on the surface of the substrate, records a plurality of servo patterns in the width direction of the magnetic tape by applying a magnetic field to the magnetic tape from the plurality of gap patterns in accordance with the pulse signal. The plurality of gap patterns are formed on the surface along the direction corresponding to the width direction, The gap pattern is a pair of linear regions consisting of a pair of non-parallel linear regions, The first linear region, which is one of the pair of linear regions, and the second linear region, which is the other of the pair of linear regions, are tilted in directions opposite to the first virtual line along the direction corresponding to the width direction on the surface. The first linear region has a steeper angle of inclination with respect to the first virtual line than the second linear region, and the total length of the first linear region is shorter than the total length of the second linear region. The positions of both ends of the first linear region and the positions of both ends of the second linear region are aligned in a direction corresponding to the width direction of the magnetic tape. On the aforementioned surface, the plurality of gap patterns are aligned in the longitudinal direction of the magnetic tape. The servo pattern recording method includes supplying the pulse signal to each of the plurality of gap patterns with a predetermined delay from one side in the direction in which the plurality of gap patterns are arranged to the other side, The magnetic tape has a plurality of servo bands formed along the width direction, The servo patterns corresponding between the servo bands are adjacent to the servos in the width direction. The bands are offset at predetermined intervals in the longitudinal direction of the magnetic tape. The servo band is divided into frames defined based on at least one set of the servo patterns, The aforementioned default time is determined according to the aforementioned default interval, The predetermined interval is defined based on the angle between the frames that are not in correspondence with adjacent servo bands in the width direction and the first virtual line, the pitch between adjacent servo bands in the width direction, and the total length of the frame in the longitudinal direction. Method for recording servo patterns.

8. A first step of recording a plurality of servo patterns on a magnetic tape according to the servo pattern recording method described in Claim 7, The process includes a second step of winding up the magnetic tape. A method for manufacturing magnetic tape.

9. An inspection device used in conjunction with a servo pattern recording device, Detection device and Equipped with a test processor, The servo pattern recording device is A pulse signal generator, Equipped with a servo pattern recording head, The pulse signal generator generates a pulse signal, The servo pattern recording head has a base and a plurality of gap patterns formed on the surface of the base, and records a plurality of servo patterns in the width direction of the magnetic tape by applying a magnetic field to the magnetic tape from the plurality of gap patterns in accordance with the pulse signal. The plurality of gap patterns are formed on the surface along the direction corresponding to the width direction, The gap pattern is a pair of linear regions consisting of a pair of non-parallel linear regions, The first linear region, which is one of the pair of linear regions, and the second linear region, which is the other of the pair of linear regions, are tilted in directions opposite to the first virtual line along the direction corresponding to the width direction on the surface. The first linear region has a steeper angle of inclination with respect to the first virtual line than the second linear region, and the total length of the first linear region is shorter than the total length of the second linear region. The positions of both ends of the first linear region and the positions of both ends of the second linear region are aligned in a direction corresponding to the width direction of the magnetic tape. On the aforementioned surface, the plurality of gap patterns are aligned in the longitudinal direction of the magnetic tape. The pulse signal generator supplies the pulse signal to each of the plurality of gap patterns with a predetermined delay from one side in the direction in which the plurality of gap patterns are arranged to the other side. The predetermined time is set such that the recording positions of adjacent servo patterns in the width direction along the longitudinal direction are recorded with a predetermined interval difference. The detection device is Equipped with a processor, The aforementioned processor, The autocorrelation coefficient is calculated for the servo signal, which is the result of reading the servo pattern from the magnetic tape using a servo reading element. Based on the calculated autocorrelation coefficient, the servo signal is detected. The inspection processor performs an inspection of the servo band on the magnetic tape where the servo pattern is recorded, based on the servo signal detected by the detection device. Inspection device.

10. A detection method used in conjunction with a servo pattern recording method, The autocorrelation coefficient of the servo signal obtained by reading the servo pattern from a magnetic tape on which multiple servo patterns have been recorded by a servo pattern recording device, using a servo reading element, and, This includes detecting the servo signal based on the calculated autocorrelation coefficient, The servo pattern recording device is A pulse signal generator, A servo pattern recording device comprising a servo pattern recording head, The pulse signal generator generates a pulse signal, The servo pattern recording head has a base and a plurality of gap patterns formed on the surface of the base, and records a plurality of servo patterns in the width direction of the magnetic tape by applying a magnetic field to the magnetic tape from the plurality of gap patterns in accordance with the pulse signal. The plurality of gap patterns are formed on the surface along the direction corresponding to the width direction, The gap pattern is a pair of linear regions consisting of a pair of non-parallel linear regions, The first linear region, which is one of the pair of linear regions, and the second linear region, which is the other of the pair of linear regions, are tilted in directions opposite to the first virtual line along the direction corresponding to the width direction on the surface. The first linear region has a steeper angle of inclination with respect to the first virtual line than the second linear region, and the total length of the first linear region is shorter than the total length of the second linear region. The positions of both ends of the first linear region and the positions of both ends of the second linear region are aligned in a direction corresponding to the width direction of the magnetic tape. On the aforementioned surface, the plurality of gap patterns are aligned in the longitudinal direction of the magnetic tape. The pulse signal generator supplies the pulse signal to each of the plurality of gap patterns with a predetermined delay from one side in the direction in which the plurality of gap patterns are arranged to the other side. The predetermined time is set such that the recording positions of adjacent servo patterns in the width direction along the longitudinal direction are recorded with a predetermined interval difference. The servo pattern recording method is, To generate the aforementioned pulse signal, The servo pattern recording head records the plurality of servo patterns in the width direction of the magnetic tape by applying the magnetic field to the magnetic tape from the plurality of gap patterns in accordance with the pulse signal, and This includes supplying the pulse signal to each of the plurality of gap patterns with a delay of the predetermined time from one side in the direction in which the plurality of gap patterns are arranged to the other side. Detection method.

11. Based on the servo signal detected by the detection method described in Claim 10, the servo band on which the servo pattern is recorded in the magnetic tape is inspected, and This includes determining whether the servo pattern is correct or incorrect. Testing method.

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