cartridge

Abstract

To provide a servo writer that reduces the number of cartridges to be discarded.SOLUTION: A servo writer 210 for a cartridge 10 includes: a traveling portion that feeds out a tape-shaped magnetic recording medium (magnetic tape MT) from the cartridge and winds the feed magnetic recording medium to make the magnetic recording medium travel; a demagnetizing magnet 214 that erases a first servo pattern formed on the traveling magnetic recording medium; a servo signal writing head 215 that writes a servo signal onto the traveling magnetic recording medium after the first servo pattern is erased and forms a second servo pattern; and a control device that controls the head to write the servo signal during at least one of acceleration and deceleration traveling periods of the magnetic recording medium and forms the second servo pattern that does not satisfy the standard on the magnetic recording medium.SELECTED DRAWING: Figure 8

Description

Technical Field

[0001] The present disclosure relates to mosquito a cartridge.

Background Art

[0002] In recent years, in a tape-shaped magnetic recording medium used as computer data storage, in order to improve the data recording density, the width of the data track and the distance between adjacent data tracks have been made narrower. When the width of the data track and the distance between adjacent data tracks are thus narrowed, it becomes difficult for the recording / regeneration element of the magnetic head to trace the data track.

[0003] For this reason, a technique has been proposed in which a servo signal is pre-written on a magnetic recording medium and the position of the recording / regeneration element of the magnetic head in the width direction of the magnetic recording medium is servo-controlled by reading this servo signal with the magnetic head (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] A magnetic recording medium on which a servo signal is written is housed in a cartridge case, and after quality inspection of the magnetic recording medium, it is shipped as a product. Conventionally, when it was found that the quality of the servo signal was poor at the above-described quality inspection stage, the cartridge was discarded. Therefore, if the number of discarded cartridges is large, there is a risk that the productivity of the cartridges will decrease.

[0006] An object of the present disclosure is a servo writer that can reduce the number of discarded cartridges of The objective is to provide a cartridge on which servo signals are recorded. [Means for solving the problem]

[0007] To address the aforementioned issues, the first disclosure states: A wound tape-shaped magnetic recording medium, A case for housing a magnetic recording medium, and a reel capable of winding a magnetic recording medium. Equipped with, A pin is provided at one end of the outer edge of the magnetic recording medium. The magnetic recording medium has a plurality of servo bands extending in the longitudinal direction of the recording medium and a plurality of data bands extending in the longitudinal direction of the recording medium. Between adjacent servo bands in the width direction of the magnetic recording medium, data bands are provided. The servo band has an unused area. Unused areas are provided in parts that are not fixed to pins and reels. In the unused area, a servo pattern that does not meet the standard is formed. cartridge That is the case.

[0008] The second disclosure is, A wound tape-shaped magnetic recording medium, A case for housing a magnetic recording medium, and a reel capable of winding a magnetic recording medium. Equipped with, A pin is provided at one end of the outer edge of the magnetic recording medium. The magnetic recording medium has a plurality of servo bands extending in the longitudinal direction of the recording medium and a plurality of data bands extending in the longitudinal direction of the recording medium. Between adjacent servo bands in the width direction of the magnetic recording medium, data bands are provided. The servo band is, From one end of the magnetic recording medium near the end of the winding to the other end near the beginning of the winding, the first unused area , the area in use and the second area not in use of In this order Yes, First unused area and the second unused area It is provided in the part that is not fixed to the pin and reel, First unused area and the second unused area There is no servo pattern formed there. It is a cartridge. [Brief explanation of the drawing]

[0010] [Figure 1] Figure 1 is an exploded perspective view showing an example of a cartridge configuration. [Figure 2] Figure 2 is a cross-sectional view showing an example of the configuration of a magnetic tape. [Figure 3] Figure 3 is a schematic diagram showing an example of the layout of the data band and servo band. [Figure 4] Figure 4 is an enlarged view showing an example of a data band configuration. [Figure 5] Figure 5 is an enlarged view showing an example of a servoband configuration. [Figure 6] Figure 6 is a schematic diagram showing an example of a magnetic tape format. [Figure 7] Figure 7A is a schematic diagram showing a first example of a servo pattern that does not meet the standard. Figure 7B is a schematic diagram showing a second example of a servo pattern that does not meet the standard. Figure 7C is a schematic diagram showing an example of a servo pattern that meets the standard. [Figure 8] Figure 8 is a schematic diagram showing an example of the configuration of a servo writer for cartridges. [Figure 9] Figure 9 is a schematic diagram showing an example of the configuration of a servo signal recording system. [Figure 10] Figure 10 is a schematic diagram showing an example of the configuration of a servo writer for pancakes. [Figure 11] Figure 11 is a schematic diagram showing an example of a winder configuration. [Modes for carrying out the invention]

[0011] Embodiments of this disclosure will be described in the following order with reference to the drawings. In all the drawings of the following embodiments, the same or corresponding parts will be denoted by the same reference numerals. 1. Cartridge Configuration 2. The structure of magnetic tape 3. Formatting magnetic tape 4. Configuration of a servo writer for cartridges 5. Operation of the servo writer for cartridges 6. Configuration of the servo signal recording system 7. Operation of the servo signal recording system 8 Effects 9 Variations

[0012] [1. Cartridge Configuration] Figure 1 is an exploded perspective view showing an example of the configuration of cartridge 10. Cartridge 10 is a magnetic tape cartridge conforming to the LTO (Linear Tape-Open) standard, and comprises a reel 13 around which magnetic tape (tape-shaped magnetic recording medium) MT is wound, a reel lock 14 and reel spring 15 for locking the rotation of reel 13, a spider 16 for releasing the locked state of reel 13, a sliding door 17 that opens and closes a tape outlet 12C provided in the cartridge case 12 spanning the lower shell 12A and upper shell 12B, a door spring 18 that biases the sliding door 17 to the closed position of the tape outlet 12C, a write protect 19 for preventing accidental erasure, and cartridge memory 11. The reel 13 is substantially disc-shaped with an opening in the center and is composed of a reel hub 13A and flange 13B made of a hard material such as plastic. A leader pin 20 is provided at one end of the magnetic tape MT.

[0013] The cartridge memory 11 is located near one corner of the cartridge 10. When the cartridge 10 is loaded into the recording / playback device, the cartridge memory 11 faces the reader / writer of the recording / playback device. The cartridge memory 11 communicates with the recording / playback device, specifically the reader / writer of the recording / playback device, using a wireless communication standard compliant with the LTO standard.

[0014] [2. Magnetic Tape Configuration] Figure 2 is a cross-sectional view showing an example of the configuration of a magnetic tape MT. The magnetic tape MT is a tape-shaped magnetic recording medium and comprises a long base body 41, a base layer 42 provided on one main surface (first main surface) of the base body 41, a magnetic layer 43 provided on the base layer 42, and a back layer 44 provided on the other main surface (second main surface) of the base body 41. The base layer 42 and the back layer 44 are provided as needed and may be omitted. The magnetic tape MT may be a vertical recording type magnetic recording medium or a longitudinal recording type magnetic recording medium.

[0015] The magnetic tape MT is preferably used in a recording and playback device equipped with a ring-type head as the recording head. The magnetic tape MT is preferably configured so that its width can be kept constant or nearly constant by adjusting the longitudinal tension of the magnetic tape MT during playback.

[0016] (Base) The substrate 41 is a non-magnetic support that supports the underlayer 42 and the magnetic layer 43. The substrate 41 has a long, film-like structure. The upper limit of the average thickness of the substrate 41 is preferably 4.2 μm or less, more preferably 3.8 μm or less, and even more preferably 3.4 μm or less. When the upper limit of the average thickness of the substrate 41 is 4.2 μm or less, the recording capacity that can be recorded in one data cartridge can be increased compared to general magnetic tape. The lower limit of the average thickness of the substrate 41 is preferably 3 μm or more, more preferably 3.2 μm or more. When the lower limit of the average thickness of the substrate 41 is 3 μm or more, a decrease in the strength of the substrate 41 can be suppressed.

[0017] The average thickness of the substrate 41 is determined as follows. First, a 1 / 2-inch wide magnetic tape MT is prepared and cut to a length of 250 mm to create a sample. Next, the layers of the sample other than the substrate 41 (i.e., the base layer 42, magnetic layer 43, and back layer 44) are removed with a solvent such as MEK (methyl ethyl ketone) or dilute hydrochloric acid. Then, using a Mitutoyo laser hologage (LGH-110C) as the measuring device, the thickness of the sample (substrate 41) is measured at five or more locations, and the average thickness of the substrate 41 is calculated by simply averaging (arithmetic mean) these measurements. The measurement locations are to be randomly selected from the sample.

[0018] The base material 41 preferably contains polyester. By including polyester in the base material 41, the Young's modulus in the longitudinal direction of the base material 41 can be reduced. Therefore, by adjusting the longitudinal tension of the magnetic tape MT during operation using the recording and playback device (drive), the width of the magnetic tape MT can be kept constant or nearly constant.

[0019] The polyester includes, for example, at least one of polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polybutylene terephthalate (PBT), polybutylene naphthalate (PBN), polycyclohexylene dimethylene terephthalate (PCT), polyethylene-p-oxybenzoate (PEB), and polyethylene bisphenoxycarboxylate. If the base 41 contains two or more polyesters, these two or more polyesters may be mixed, copolymerized, or laminated. At least one of the ends and side chains of the polyester may be modified.

[0020] The presence of polyester in the substrate 41 can be confirmed, for example, as follows: First, layers other than the substrate 41 are removed from the sample in the same manner as the method for measuring the average thickness of the substrate 41. Next, the IR spectrum of the sample (substrate 41) is obtained by infrared absorption spectroscopy (IR). Based on this IR spectrum, it can be confirmed that the substrate 41 contains polyester.

[0021] The base material 41 may further contain, for example, at least one of polyamide, polyimide, and polyamideimide, or it may further contain at least one of polyamide, polyimide, polyamideimide, polyolefins, cellulose derivatives, vinyl resins, and other polymer resins. The polyamide may be an aromatic polyamide (aramid). The polyimide may be an aromatic polyimide. The polyamideimide may be an aromatic polyamideimide.

[0022] If the base material 41 contains polymer resins other than polyester, it is preferable that the base material 41 has polyester as its main component. Here, the main component refers to the component that has the highest content (mass ratio) among the polymer resins contained in the base material 41. If the base material 41 contains polymer resins other than polyester, the polyester and the polymer resins other than polyester may be mixed or copolymerized.

[0023] The substrate 41 may be biaxially stretched in the longitudinal and width directions. Preferably, the polymer resin contained in the substrate 41 is oriented obliquely to the width direction of the substrate 41.

[0024] (magnetic layer) The magnetic layer 43 is a recording layer for recording signals by a magnetization pattern. The magnetic layer 43 may be a vertical recording layer or a longitudinal recording layer. The magnetic layer 43 includes, for example, magnetic powder and a binder. The magnetic layer 43 may further include, if necessary, at least one additive from among lubricants, antistatic agents, abrasives, hardeners, rust inhibitors, and non-magnetic reinforcing particles.

[0025] Average thickness t of magnetic layer 43 m The upper limit is 80 nm or less, preferably 70 nm or less, and more preferably 50 nm or less. Average thickness t of the magnetic layer 43 m If the upper limit is 80 nm or less, the effect of the demagnetizing field can be reduced when a ring-type head is used as the recording head, thereby obtaining even better electromagnetic conversion characteristics.

[0026] Average thickness t of magnetic layer 43 m The lower limit is preferably 35 nm or more. Average thickness t of the magnetic layer 43 m If the lower limit is 35 nm or higher, output can be secured when using a magnetoresistive (MR) head, giant magnetoresistive (GMR) head, or tunnel magnetoresistive (TMR) head as the regeneration head, thereby obtaining even better electromagnetic conversion characteristics.

[0027] Average thickness t of magnetic layer 43 m The following is how it is determined. First, the magnetic tape MT to be measured is processed and thinned using the FIB method or the like. When using the FIB method, a carbon layer and a tungsten layer are formed as protective films as a pretreatment before observing the TEM image of the cross-section described later. The carbon layer is formed on the surface of the magnetic layer 43 side and the surface of the back layer 44 side of the magnetic tape MT by vapor deposition, and the tungsten layer is further formed on the surface of the magnetic layer 43 side by vapor deposition or sputtering. This thinning is performed along the length direction (longitudinal direction) of the magnetic tape MT. That is, this thinning creates a cross-section that is parallel to both the longitudinal direction and the thickness direction of the magnetic tape MT.

[0028] The cross-section of the obtained thin section sample is observed using a transmission electron microscope (TEM) under the following conditions to obtain a TEM image. The magnification and acceleration voltage may be adjusted as appropriate depending on the type of instrument. Equipment: TEM (Hitachi H9000NAR) Acceleration voltage: 300kV Magnification: 100,000x

[0029] Next, using the obtained TEM image, the thickness of the magnetic layer 43 is measured at at least 10 points along the longitudinal direction of the magnetic tape MT. The average value obtained by simply averaging (arithmetic mean) the obtained measurements is used to determine the average thickness t of the magnetic layer 43. m The measurement will be performed in [nm]. The location where the above measurement is performed will be randomly selected from the test specimen.

[0030] (magnetic powder) The magnetic powder contains multiple magnetic particles. These magnetic particles are, for example, particles containing hexagonal ferrite (hereinafter referred to as "hexagonal ferrite particles"), particles containing epsilon-type iron oxide (ε-iron oxide) (hereinafter referred to as "ε-iron oxide particles"), or particles containing Co-containing spinel ferrite (hereinafter referred to as "cobalt ferrite particles"). It is preferable that the magnetic powder is preferentially crystallinely oriented in the thickness direction (perpendicular direction) of the magnetic tape MT.

[0031] (Hexagonal ferrite particles) Hexagonal ferrite particles have a plate-like shape, such as a hexagonal plate shape. In this specification, hexagonal plate shape includes substantially hexagonal plate shape. Hexagonal ferrite preferably contains at least one of Ba, Sr, Pb, and Ca, more preferably at least one of Ba and Sr. Specifically, hexagonal ferrite may be, for example, barium ferrite or strontium ferrite. Barium ferrite may further contain at least one of Sr, Pb, and Ca in addition to Ba. Strontium ferrite may further contain at least one of Ba, Pb, and Ca in addition to Sr.

[0032] More specifically, hexagonal ferrite has the general formula MFe 12 O 19 It has an average composition represented by the formula above. However, M is, for example, at least one metal from among Ba, Sr, Pb, and Ca, preferably at least one metal from among Ba and Sr. M may be a combination of Ba and one or more metals selected from the group consisting of Sr, Pb, and Ca. Alternatively, M may be a combination of Sr and one or more metals selected from the group consisting of Ba, Pb, and Ca. In the above general formula, a portion of Fe may be substituted with other metallic elements.

[0033] (ε-iron oxide particles) ε-iron oxide particles are hard magnetic particles that can obtain high coercivity even in fine particles. ε-iron oxide particles are either spherical or cubic in shape. In this specification, "spherical" includes substantially spherical particles, and "cubic" includes substantially cubic particles. Because ε-iron oxide particles have the shapes described above, when ε-iron oxide particles are used as magnetic particles, the contact area between particles in the thickness direction of the magnetic tape MT can be reduced and particle aggregation can be suppressed compared to when hexagonal plate-shaped barium ferrite particles are used as magnetic particles. Therefore, the dispersibility of the magnetic powder can be improved, and even better electromagnetic conversion characteristics (e.g., SNR) can be obtained.

[0034] ε-iron oxide particles have a core-shell structure. Specifically, the ε-iron oxide particles comprise a core portion and a two-layer shell portion surrounding the core portion. The two-layer shell portion comprises a first shell portion provided on the core portion and a second shell portion provided on the first shell portion.

[0035] The core contains ε-iron oxide. The ε-iron oxide contained in the core is preferably composed mainly of ε-Fe2O3 crystals, and more preferably of single-phase ε-Fe2O3.

[0036] The first shell portion covers at least a part of the periphery of the core portion. Specifically, the first shell portion may partially cover the periphery of the core portion or cover the entire periphery of the core portion. From the viewpoint of ensuring sufficient exchange coupling between the core portion and the first shell portion and improving magnetic properties, it is preferable that the first shell portion covers the entire surface of the core portion.

[0037] The first shell portion is a so-called soft magnetic layer, and includes, for example, a soft magnetic material such as α-Fe, a Ni-Fe alloy, or a Fe-Si-Al alloy. α-Fe may be obtained by reducing ε-iron oxide contained in the core portion.

[0038] The second shell portion is an oxide film serving as an anti-oxidation layer. The second shell portion contains α-iron oxide, aluminum oxide, or silicon oxide. The α-iron oxide includes, for example, at least one of Fe3O4, Fe2O3, and FeO. If the first shell portion contains α-Fe (a soft magnetic material), the α-iron oxide may be obtained by oxidizing the α-Fe contained in the first shell portion.

[0039] As described above, the presence of a first shell portion in the ε-iron oxide particles allows for maintaining a high coercivity Hc of the core portion alone to ensure thermal stability, while simultaneously adjusting the overall coercivity Hc of the ε-iron oxide particles (core-shell particles) to a level suitable for recording. Furthermore, as described above, the presence of a second shell portion in the ε-iron oxide particles prevents the deterioration of the properties of the ε-iron oxide particles caused by exposure to air during and before the manufacturing process of magnetic tape MT, which can lead to rust formation on the particle surface. Therefore, the deterioration of the properties of magnetic tape MT can be suppressed.

[0040] The ε-iron oxide particles may have a single-layer shell. In this case, the shell has the same structure as the first shell. However, from the viewpoint of suppressing the deterioration of the properties of the ε-iron oxide particles, it is preferable that the ε-iron oxide particles have a two-layer shell, as described above.

[0041] The ε-iron oxide particles may contain an additive instead of the above core-shell structure, or may have a core-shell structure and contain an additive. In this case, a part of Fe in the ε-iron oxide particles is replaced by the additive. Since the coercive force Hc of the whole ε-iron oxide particles can be adjusted to a coercive force Hc suitable for recording by the ε-iron oxide particles containing an additive, the ease of recording can be improved. The additive is a metal element other than iron, preferably a trivalent metal element, more preferably at least one of Al, Ga, and In, and even more preferably at least one of Al and Ga.

[0042] Specifically, ε-iron oxide containing an additive is ε-Fe 2-x M x O3 crystal (where M is a metal element other than iron, preferably a trivalent metal element, more preferably at least one of Al, Ga, and In, and even more preferably at least one of Al and Ga. x is, for example, 0 < x < 1).

[0043] (Cobalt ferrite particles) The cobalt ferrite particles preferably have uniaxial crystal anisotropy. Since the cobalt ferrite particles have uniaxial crystal anisotropy, the magnetic powder can be preferentially crystal-oriented in the thickness direction (vertical direction) of the magnetic tape MT. The cobalt ferrite particles, for example, have a cubic shape. In this specification, the cubic shape includes a substantially cubic shape. The Co-containing spinel ferrite may further contain at least one of Ni, Mn, Al, Cu, and Zn in addition to Co.

[0044] The Co-containing spinel ferrite has an average composition represented by, for example, the following formula. Co x M y Fe2O Z (However, in the formula, M is at least one metal from, for example, Ni, Mn, Al, Cu, and Zn. x is a value in the range 0.4 ≤ x ≤ 1.0. y is a value in the range 0 ≤ y ≤ 0.3, where x and y satisfy the relationship (x + y) ≤ 1.0. z is a value in the range 3 ≤ z ≤ 4. Part of Fe may be substituted with other metallic elements.)

[0045] (Binding agent) Examples of binders include thermoplastic resins, thermosetting resins, and reactive resins. Examples of thermoplastic resins include vinyl chloride, vinyl acetate, vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinylidene chloride copolymer, vinyl chloride-acrylonitrile copolymer, acrylic acid ester-acrylonitrile copolymer, acrylic acid ester-vinyl chloride-vinylidene chloride copolymer, acrylic acid ester-acrylonitrile copolymer, acrylic acid ester-vinylidene chloride copolymer, methacrylic acid ester-vinylidene chloride copolymer, methacrylic acid ester-vinyl chloride copolymer, methacrylic acid ester-ethylene copolymer, polyvinyl fluoride, vinylidene chloride-acrylonitrile copolymer, acrylonitrile-butadiene copolymer, polyamide resin, polyvinyl butyral, cellulose derivatives (cellulose acetate butyrate, cellulose diacetate, cellulose triacetate, cellulose propionate, nitrocellulose), styrene butadiene copolymer, polyurethane resin, polyester resin, amino resin, and synthetic rubber.

[0046] Examples of thermosetting resins include phenolic resins, epoxy resins, polyurethane curing resins, urea resins, melamine resins, alkyd resins, silicone resins, polyamine resins, and urea-formaldehyde resins.

[0047] All of the above binders include -SO3M, -OSO3M, -COOM, P=O(OM)2 (where M represents a hydrogen atom or an alkali metal such as lithium, potassium, or sodium), and -NR1R2, -NR1R2R3, in order to improve the dispersibility of magnetic powders. + X -Side-chain amines having terminal groups represented by >NR1R2 + X - Main-chain amines represented by (wherein R1, R2, and R3 represent hydrogen atoms or hydrocarbon groups, X - ) represents halogen element ions such as fluorine, chlorine, bromine, and iodine, as well as inorganic or organic ions. Furthermore, polar functional groups such as -OH, -SH, -CN, and epoxy groups may be introduced. The amount of these polar functional groups introduced into the binder is 10 -1 ~10 -8 It is preferable that it be in moles / g, 10 -2 ~10 -6 It is more preferable to use moles / g.

[0048] (Lubricant) The lubricant comprises at least one selected from, for example, fatty acids and fatty acid esters, preferably both fatty acids and fatty acid esters. The inclusion of a lubricant in the magnetic layer 43, and in particular the inclusion of both fatty acids and fatty acid esters in the magnetic layer 43, contributes to improving the running stability of the magnetic tape MT.

[0049] The fatty acid may preferably be a compound represented by the following general formula (1) or (2). For example, the fatty acid may include one of the compounds represented by the following general formula (1) and the compound represented by the following general formula (2), or both.

[0050] Furthermore, the fatty acid ester may preferably be a compound represented by the following general formula (3) or (4). For example, the fatty acid ester may include either a compound represented by the following general formula (3) or a compound represented by the following general formula (4), or both.

[0051] By including either or both of the compounds shown in general formula (1) and general formula (2), and either or both of the compounds shown in general formula (3) and general formula (4), the increase in the coefficient of dynamic friction due to repeated recording or playback of magnetic tape MT can be suppressed.

[0052] CH3(CH2) k COOH ···(1) (However, in general formula (1), k is an integer selected from the range of 14 to 22, more preferably from the range of 14 to 18.)

[0053] CH3(CH2) n CH=CH(CH2) m COOH ···(2) (However, in general formula (2), the sum of n and m is an integer selected from the range of 12 to 20, more preferably from the range of 14 to 18.)

[0054] CH3(CH2) p COO(CH2) q CH3···(3) (However, in general formula (3), p is an integer selected from the range of 14 to 22, more preferably from 14 to 18, and q is an integer selected from the range of 2 to 5, more preferably from 2 to 4.)

[0055] CH3(CH2) r COO-(CH2) s CH(CH3)2···(4) (However, in general formula (4), r is an integer selected from the range of 14 to 22, and s is an integer selected from the range of 1 to 3.)

[0056] (Antistatic agent) Examples of antistatic agents include carbon black, natural surfactants, nonionic surfactants, and cationic surfactants.

[0057] (Abrasive) Examples of abrasives include α-alumina, β-alumina, γ-alumina, silicon carbide, chromium oxide, cerium oxide, α-iron oxide, corundum, silicon nitride, titanium carbide, titanium oxide, silicon dioxide, tin oxide, magnesium oxide, tungsten oxide, zirconium oxide, boron nitride, zinc oxide, calcium carbonate, calcium sulfate, barium sulfate, molybdenum disulfide, and needle-shaped α-iron oxide obtained by dehydrating and annealing the raw materials of magnetic iron oxide, and, if necessary, surface-treated with aluminum and / or silica.

[0058] (Hardening agent) Examples of curing agents include polyisocyanates. Examples of polyisocyanates include aromatic polyisocyanates such as adducts of tolylene diisocyanate (TDI) and active hydrogen compounds, and aliphatic polyisocyanates such as adducts of hexamethylene diisocyanate (HMDI) and active hydrogen compounds. The weight-average molecular weight of these polyisocyanates is preferably in the range of 100 to 3000.

[0059] (Rust inhibitor) Examples of rust inhibitors include phenols, naphthols, quinones, heterocyclic compounds containing nitrogen atoms, heterocyclic compounds containing oxygen atoms, and heterocyclic compounds containing sulfur atoms.

[0060] (Non-magnetic reinforced particles) Examples of non-magnetic reinforcing particles include aluminum oxide (α, β, or γ alumina), chromium oxide, silicon oxide, diamond, garnet, emery, boron nitride, titanium carbide, silicon carbide, titanium carbide, and titanium oxide (rutile or anatase type titanium oxide).

[0061] (base layer) The base layer 42 is intended to alleviate surface irregularities of the substrate 41 and adjust surface irregularities of the magnetic layer 43. The base layer 42 is a non-magnetic layer containing non-magnetic powder, a binder, and a lubricant. The base layer 42 supplies lubricant to the surface of the magnetic layer 43. The base layer 42 may further contain at least one additive, such as an antistatic agent, a hardening agent, and a rust inhibitor, as needed.

[0062] The average thickness of the base layer 42 is preferably 0.3 μm or more and 2.0 μm or less, more preferably 0.5 μm or more and 1.4 μm or less. The average thickness of the base layer 42 is equal to the average thickness t of the magnetic layer 43. m It can be determined in the same manner as above. However, the magnification of the TEM image is adjusted as appropriate according to the thickness of the underlying layer 42. If the average thickness of the underlying layer 42 is 2.0 μm or less, the elasticity of the magnetic tape MT due to external force becomes even higher, making it even easier to adjust the width of the magnetic tape MT by adjusting the tension.

[0063] (Non-magnetic powder) The non-magnetic powder includes, for example, at least one of inorganic particulate powder or organic particulate powder. The non-magnetic powder may also include carbon powder such as carbon black. One type of non-magnetic powder may be used alone, or two or more types of non-magnetic powder may be used in combination. Inorganic particles include, for example, metals, metal oxides, metal carbonates, metal sulfates, metal nitrides, metal carbides, or metal sulfides. The shape of the non-magnetic powder can be, for example, needle-shaped, spherical, cubic, or plate-shaped, but is not limited to these shapes.

[0064] (Binding agent, lubricant) The binder and lubricant are the same as those used in the magnetic layer 43 described above.

[0065] (Additives) The antistatic agent, hardening agent, and rust inhibitor are the same as those described above for the magnetic layer 43.

[0066] (Back layer) The back layer 44 contains a binder and non-magnetic powder. The back layer 44 may further contain at least one additive, if necessary, from among lubricants, hardeners, and antistatic agents. The binder and non-magnetic powder are the same as those in the base layer 42 described above.

[0067] The upper limit of the average thickness of the backing layer 44 is preferably 0.6 μm or less. When the upper limit of the average thickness of the backing layer 44 is 0.6 μm or less, the thickness of the underlayment layer 42 and the substrate 41 can be kept thick even when the average thickness of the magnetic tape MT is 5.6 μm or less, thereby maintaining the running stability of the magnetic tape MT within the recording and playback device. The lower limit of the average thickness of the backing layer 44 is not particularly limited, but for example, it is 0.2 μm or more.

[0068] Average thickness t of back layer 44 b The average thickness t of the magnetic tape MT can be calculated as follows. First, the average thickness t of the magnetic tape MT can be calculated as follows. T Measure the average thickness t. T The measurement method is as described in "Average Thickness of Magnetic Tape" below. Next, the back layer 44 of the sample is removed with a solvent such as MEK (methyl ethyl ketone) or dilute hydrochloric acid. Then, the thickness of the sample is measured at five or more locations using a Mitutoyo laser hologage (LGH-110C), and these measurements are simply averaged (arithmetic mean) to obtain the average value t B [μm] is calculated. Then, the average thickness t of the back layer 44 is calculated using the following formula. b Determine the [μm]. The measurement location will be randomly selected from the sample. t b [μm]=t T [μm]-t B [μm]

[0069] (Average thickness of magnetic tape) Average thickness (average total thickness) of magnetic tape MT T The upper limit of is 5.6 μm or less, preferably 5.0 μm or less, more preferably 4.6 μm or less, and even more preferably 4.4 μm or less. Average thickness t of magnetic tape MT TIf the average thickness of the magnetic tape (MT) is 5.6 μm or less, the recording capacity that can be recorded in one data cartridge can be increased compared to typical magnetic tapes. T The lower limit is not particularly restricted, but for example, it is 3.5 μm or larger.

[0070] Average thickness t of magnetic tape MT T The thickness t is calculated as follows: First, a 1 / 2-inch wide magnetic tape MT is prepared and cut to a length of 250 mm to make a sample. Next, a Mitutoyo laser hologage (LGH-110C) is used as a measuring device to measure the thickness of the sample at five or more points, and these measurements are simply averaged (arithmetic mean) to obtain the average thickness t. T Calculate the [μm] measurement. The measurement location will be randomly selected from the sample.

[0071] (Coercivity) The upper limit of the coercivity Hc2 of the magnetic layer 43 in the longitudinal direction of the magnetic tape MT is preferably 2000 Oe or less, more preferably 1900 Oe or less, and even more preferably 1800 Oe or less. When the coercivity Hc2 of the magnetic layer 43 in the longitudinal direction is 2000 Oe or less, sufficient electromagnetic conversion characteristics can be obtained even at high recording densities.

[0072] The lower limit of the coercivity Hc2 of the magnetic layer 43 measured in the longitudinal direction of the magnetic tape MT is preferably 1000Oe or more. When the coercivity Hc2 of the magnetic layer 43 measured in the longitudinal direction is 1000Oe or more, demagnetization due to leakage magnetic flux from the recording head can be suppressed.

[0073] The above coercivity Hc2 is determined as follows. First, three magnetic tapes MT are stacked together with double-sided tape, and then punched out with a φ6.39 mm punch to create a measurement sample. At this time, the magnetic tapes MT are marked with an arbitrary non-magnetic ink so that the longitudinal direction (direction of travel) of the magnetic tapes MT can be recognized. Then, the MH loop of the measurement sample (the entire magnetic tape MT) corresponding to the longitudinal direction (direction of travel) of the magnetic tapes MT is measured using a vibrating sample magnetometer (VSM). Next, the coating (underlayer 42, magnetic layer 43, and back layer 44, etc.) is wiped off using acetone or ethanol, leaving only the substrate 41. Then, three of the obtained substrates 41 are stacked together with double-sided tape, and then punched out with a φ6.39 mm punch to create a sample for background correction (hereinafter simply referred to as the "correction sample"). Subsequently, the MH loop of the correction sample (substrate 41) corresponding to the vertical direction of the substrate 41 (the vertical direction of the magnetic tape MT) is measured using a VSM.

[0074] For measuring the MH loop of the measurement sample (the entire magnetic tape MT) and the MH loop of the correction sample (substrate 41), a high-sensitivity vibrating sample type magnetometer "VSM-P7-15" manufactured by Toei Kogyo Co., Ltd. is used. The measurement conditions are as follows: measurement mode: full loop, maximum magnetic field: 15 kOe, magnetic field step: 40 bits, time constant of locking amp: 0.3 sec, waiting time: 1 sec, MH average number: 20.

[0075] After obtaining the MH loop of the measurement sample (the entire magnetic tape MT) and the MH loop of the correction sample (substrate 41), background correction is performed by subtracting the MH loop of the correction sample (substrate 41) from the MH loop of the measurement sample (the entire magnetic tape MT), and the background-corrected MH loop is obtained. The measurement and analysis program included with the "VSM-P7-15" is used to calculate this background correction. The coercivity Hc2 is determined from the obtained background-corrected MH loop. The measurement and analysis program included with the "VSM-P7-15" is used for this calculation as well. All of the above MH loop measurements are performed at 25°C. Furthermore, "demagnetization correction" is not performed when measuring the MH loop in the longitudinal direction of the magnetic tape MT.

[0076] (Gangular ratio) The angularity ratio S1 of the magnetic layer 43 in the vertical direction (thickness direction) of the magnetic tape MT is preferably 65% ​​or more, more preferably 70% or more, even more preferably 75% or more, particularly preferably 80% or more, and most preferably 85% or more. When the angularity ratio S1 is 65% or more, the vertical orientation of the magnetic powder becomes sufficiently high, and even better electromagnetic conversion characteristics can be obtained.

[0077] The aspect ratio S1 in the vertical direction is determined as follows. First, three magnetic tapes MT are stacked together with double-sided tape, and then punched out with a φ6.39 mm punch to create a measurement sample. At this time, the magnetic tapes MT are marked with an arbitrary non-magnetic ink so that the longitudinal direction (travel direction) of the magnetic tapes MT can be recognized. Then, the MH loop of the measurement sample (the entire magnetic tape MT) corresponding to the vertical direction (thickness direction) of the magnetic tape MT is measured using a VSM. Next, the coating (underlayer 42, magnetic layer 43, and back layer 44, etc.) is wiped off using acetone or ethanol, leaving only the substrate 41. Then, three of the obtained substrates 41 are stacked together with double-sided tape, and then punched out with a φ6.39 mm punch to create a sample for background correction (hereinafter simply referred to as the "correction sample"). After that, the MH loop of the correction sample (substrate 41) corresponding to the vertical direction of the substrate 41 (the vertical direction of the magnetic tape MT) is measured using a VSM.

[0078] For measuring the MH loop of the measurement sample (the entire magnetic tape MT) and the MH loop of the correction sample (substrate 41), a high-sensitivity vibrating sample type magnetometer "VSM-P7-15" manufactured by Toei Kogyo Co., Ltd. is used. The measurement conditions are as follows: measurement mode: full loop, maximum magnetic field: 15 kOe, magnetic field step: 40 bits, time constant of locking amp: 0.3 sec, waiting time: 1 sec, MH average number: 20.

[0079] After obtaining the MH loop of the measurement sample (the entire magnetic tape MT) and the MH loop of the correction sample (substrate 41), background correction is performed by subtracting the MH loop of the correction sample (substrate 41) from the MH loop of the measurement sample (the entire magnetic tape MT), and the MH loop after background correction is obtained. The measurement and analysis program included with the "VSM-P7-15" is used to calculate this background correction.

[0080] The obtained background-corrected saturation magnetization Ms(emu) and remanent magnetization Mr(emu) of the MH loop are substituted into the following formula to calculate the square aspect ratio S1(%). Note that all MH loop measurements are performed at 25°C. Furthermore, "demagnetization correction" is not performed when measuring the MH loop perpendicular to the magnetic tape MT. The measurement and analysis program included with the "VSM-P7-15" is used for this calculation. Squareness ratio S1(%)=(Mr / Ms)×100

[0081] The angularity ratio S2 of the magnetic layer 43 in the longitudinal direction (travel direction) of the magnetic tape MT is preferably 35% or less, more preferably 30% or less, even more preferably 25% or less, particularly preferably 20% or less, and most preferably 15% or less. When the angularity ratio S2 is 35% or less, the vertical orientation of the magnetic powder becomes sufficiently high, so even better electromagnetic conversion characteristics can be obtained.

[0082] The aspect ratio S2 in the longitudinal direction is determined in the same manner as the aspect ratio S1, except that the MH loop is measured in the longitudinal direction (travel direction) of the magnetic tape MT and the base 41.

[0083] (Ratio of coercivity) The ratio Hc2 / Hc1 of the coercivity Hc1 of the magnetic layer 43 in the vertical direction to the coercivity Hc2 of the magnetic layer 43 in the longitudinal direction satisfies the relationship Hc2 / Hc1 ≤ 0.8, preferably Hc2 / Hc1 ≤ 0.75, more preferably Hc2 / Hc1 ≤ 0.7, even more preferably Hc2 / Hc1 ≤ 0.65, and particularly preferably Hc2 / Hc1 ≤ 0.6. By satisfying the relationship Hc2 / Hc1 ≤ 0.8 for coercivity Hc1 and Hc2, the degree of vertical orientation of the magnetic powder can be increased. Therefore, the magnetization transition width can be reduced and a high-output signal can be obtained during signal reproduction, thus achieving even better electromagnetic conversion characteristics. As mentioned above, when Hc2 is small, the magnetization responds sensitively to the vertical magnetic field from the recording head, so a good recording pattern can be formed.

[0084] When the ratio Hc2 / Hc1 is Hc2 / Hc1 ≤ 0.8, the average thickness t of the magnetic layer 43 m It is particularly effective if the average thickness of the magnetic layer 43 is t. m If the wavelength exceeds 90 nm, when a ring-type head is used as the recording head, the lower region of the magnetic layer 43 (the region on the base layer 42 side) may become magnetized in the longitudinal direction, making it impossible to uniformly magnetize the magnetic layer 43 in the thickness direction. Therefore, even if the ratio Hc2 / Hc1 is set to Hc2 / Hc1 ≤ 0.8 (i.e., even if the degree of vertical orientation of the magnetic powder is increased), it may become impossible to obtain even better electromagnetic conversion characteristics.

[0085] There is no particular lower limit to Hc2 / Hc1, but for example, it is 0.5 ≤ Hc2 / Hc1. Note that Hc2 / Hc1 represents the degree of vertical orientation of the magnetic powder, and the smaller Hc2 / Hc1, the higher the degree of vertical orientation of the magnetic powder.

[0086] The method for calculating the coercivity Hc2 of the magnetic layer 43 in the longitudinal direction is as described above. The coercivity Hc1 of the magnetic layer 43 in the vertical direction can be determined in the same way as the coercivity Hc2 of the magnetic layer 43 in the longitudinal direction, except that the MH loop is measured in the direction perpendicular (thickness direction) to the magnetic tape MT and the substrate 41.

[0087] (Young's modulus in the longitudinal direction of magnetic tape) The Young's modulus in the longitudinal direction of the magnetic tape MT is preferably 8.0 GPa or less, more preferably 7.9 GPa or less, even more preferably 7.5 GPa or less, and particularly preferably 7.1 GPa or less. When the Young's modulus in the longitudinal direction of the magnetic tape MT is 8.0 GPa or less, the elasticity of the magnetic tape MT due to external forces is further increased, making it easier to adjust the width of the magnetic tape MT by tension adjustment. Therefore, off-track can be suppressed more effectively, and the data recorded on the magnetic tape MT can be reproduced more accurately.

[0088] The Young's modulus in the longitudinal direction of a magnetic tape MT is a value that indicates how difficult it is for the magnetic tape MT to expand or contract in the longitudinal direction due to external forces. The larger this value, the more difficult it is for the magnetic tape MT to expand or contract in the longitudinal direction due to external forces, and the smaller this value, the more easily the magnetic tape MT expands or contracts in the longitudinal direction due to external forces.

[0089] The Young's modulus in the longitudinal direction of a magnetic tape (MT) is a value related to the longitudinal direction of the magnetic tape (MT), but it also correlates with the resistance of the magnetic tape (MT) to stretching or contracting in the width direction. In other words, the larger this value, the less the magnetic tape (MT) is susceptible to stretching or contracting in the width direction due to external forces, and the smaller this value, the more easily the magnetic tape (MT) is stretched or contracted in the width direction due to external forces. Therefore, from the standpoint of tension adjustment, a smaller Young's modulus in the longitudinal direction of the magnetic tape (MT) is advantageous.

[0090] A tensile testing machine (Shimadzu Corporation, AG-100D) is used to measure Young's modulus. To measure the Young's modulus in the longitudinal direction of the tape, prepare a sample by cutting the tape to a length of 180 mm. Attach a jig that can fix the width of the tape (1 / 2 inch) to the tensile testing machine and fix the top and bottom of the tape width. The distance (length of the tape between chucks) should be 100 mm. After chucking the tape sample, gradually apply stress in the direction of tensile strength. The tensile speed should be 0.1 mm / min. From the change in stress and elongation at this time, calculate the Young's modulus using the following formula. E(N / m 2 ) = ((ΔN / S) / (Δx / L)) × 10 6 ΔN: Change in stress (N) S: Cross-sectional area of ​​the test specimen (mm²) 2 ) Δx: Elongation (mm) L: Distance between gripping fixtures (mm) The stress range is set to 0.5N to 1.0N, and the stress change (ΔN) and elongation (Δx) at this range are used in the calculation.

[0091] (Young's modulus in the longitudinal direction of the substrate) The Young's modulus in the longitudinal direction of the substrate 41 is preferably 7.5 GPa or less, more preferably 7.4 GPa or less, even more preferably 7.0 GPa or less, and particularly preferably 6.6 GPa or less. When the Young's modulus in the longitudinal direction of the substrate 41 is 7.5 GPa or less, the elasticity of the magnetic tape MT due to external forces is further increased, making it easier to adjust the width of the magnetic tape MT by tension adjustment. Therefore, off-track can be suppressed more effectively, and the data recorded on the magnetic tape MT can be reproduced more accurately.

[0092] The longitudinal Young's modulus of the substrate 41 described above can be determined as follows. First, the base layer 42, magnetic layer 43, and back layer 44 are removed from the magnetic tape MT to obtain the substrate 41. Using this substrate 41, the longitudinal Young's modulus of the substrate 41 is determined using the same procedure as for the longitudinal Young's modulus of the magnetic tape MT described above.

[0093] The thickness of the substrate 41 accounts for more than half of the total thickness of the magnetic tape MT. Therefore, the Young's modulus in the longitudinal direction of the substrate 41 is correlated with the resistance of the magnetic tape MT to expansion and contraction due to external forces. The larger this value, the less the magnetic tape MT is likely to expand and contract in the width direction due to external forces, and the smaller this value, the more likely the magnetic tape MT is to expand and contract in the width direction due to external forces.

[0094] The Young's modulus of the base 41 in the longitudinal direction is a value related to the longitudinal direction of the magnetic tape MT, but it also correlates with the resistance of the magnetic tape MT to expansion and contraction in the width direction. In other words, the larger this value, the less the magnetic tape MT is susceptible to expansion and contraction in the width direction due to external forces, and the smaller this value, the more easily the magnetic tape MT is expanded and contracted in the width direction due to external forces. Therefore, from the viewpoint of tension adjustment, a smaller Young's modulus of the base 41 in the longitudinal direction is advantageous.

[0095] [3 Magnetic Tape Formatting] Figure 3 is a schematic diagram showing an example of the layout of data bands and servo bands. The magnetic tape MT (specifically the magnetic layer 43) has multiple servo bands SB and multiple data bands DB pre-installed. The multiple servo bands SB are provided at equal intervals in the width direction of the magnetic tape MT. Data bands DB are provided between adjacent servo bands SB. The servo bands SB are for guiding the magnetic heads 51 (specifically servo read heads 51A, 51B) of the recording / playback device (drive) when recording or playing back data. Servo patterns (servo signals) for tracking control of the magnetic heads 51 are pre-written to the servo bands SB. User data is recorded in the data bands DB.

[0096] The total area S of the multiple servo bands SB relative to the surface area S of the magnetic layer 43 SB Ratio R S (=(S SB The upper limit of (S) × 100) is preferably 4.0% or less, more preferably 3.0% or less, and even more preferably 2.0% or less, from the viewpoint of ensuring high recording capacity. On the other hand, the total area S of the multiple servo bands SB relative to the surface area S of the magnetic layer 43. SB Ratio R S The lower limit is preferably 0.8% or higher, from the viewpoint of ensuring a servo band SB of 5 or more.

[0097] The total area S of the multiple servo bands SB relative to the total surface area S of the magnetic layer 43 SB The ratio RS is determined as follows: The magnetic tape MT is developed using a ferricolloid developer (Sigma Marker Q, manufactured by Sigma Hi-Chemical Co., Ltd.), and then the developed magnetic tape MT is observed with an optical microscope to determine the servobandwidth W. SB Then, measure the number of servo bands SB. Next, calculate the ratio R from the following formula. S We seek. Ratio R S [%]=(((ServobandwidthW SB ) × (Number of servo bands SB) / (Width of magnetic tape MT) × 100

[0098] The number of servo bands SB is preferably 5 or more, more preferably 5 + 4n (where n is a positive integer) or more. Having 5 or more servo bands SB suppresses the influence of changes in the width direction of the magnetic tape MT on the servo signal, ensuring more stable recording and playback characteristics with fewer off-tracks. There is no particular upper limit to the number of servo bands SB, but for example, it is 33 or less.

[0099] The number of servo bands SB can be determined in the same way as the method for calculating the ratio RS described above.

[0100] Servo bandwidth W SB The upper limit of the servo bandwidth W is preferably 99 μm or less, more preferably 60 μm or less, and even more preferably 30 μm or less, from the viewpoint of ensuring high recording capacity. SB The lower limit is preferably 10 μm or more.

[0101] Servo bandwidth W SB The width is determined in the same way as the method for calculating the ratio RS described above.

[0102] Figure 4 is an enlarged view showing an example of the data band configuration. The magnetic layer 43 is configured to form multiple data tracks Tk in the data band DB. The upper limit of the data track width W is preferably 2000 nm or less, more preferably 1500 nm or less, and even more preferably 1000 nm, from the viewpoint of improving track recording density and ensuring high recording capacity. The lower limit of the data track width W is preferably 20 nm or more, considering the magnetic particle size.

[0103] The magnetic layer 43 is configured to record data such that, from the viewpoint of ensuring high recording capacity, the minimum value L of the magnetization reversal distance is preferably 48 nm or less, more preferably 44 nm or less, and even more preferably 40 nm or less. The lower limit of the minimum value L of the magnetization reversal distance is preferably 20 nm or more, considering the size of the magnetic particles.

[0104] The magnetic layer 43 is configured to record data such that the minimum value L of the distance between magnetization reversals and the data track width W are preferably W / L ≤ 35, more preferably W / L ≤ 30, and even better, W / L ≤ 25. If the minimum value L of the distance between magnetization reversals is constant and the relationship between the minimum value L of the distance between magnetization reversals and the track width W is W / L > 35 (i.e., the track width W is large), the track recording density will not increase, and there is a risk that sufficient recording capacity will not be secured. Also, if the track width W is constant and the relationship between the minimum value L of the distance between magnetization reversals and the track width W is W / L > 35 (i.e., the minimum value L of the distance between magnetization reversals is small), the bit length will decrease and the line recording density will increase, but there is a risk that the electromagnetic conversion characteristics will deteriorate significantly due to the effect of spacing loss. Therefore, in order to secure recording capacity while suppressing deterioration of electromagnetic conversion characteristics, it is preferable that W / L be in the range of W / L ≤ 35 as described above. The lower limit of W / L is not particularly restricted, but for example, it is 1 ≤ W / L.

[0105] The data track width W is determined as follows: A magnetic tape MT with data recorded across its entire surface is prepared, and the data recording pattern of the data band DB portion of the magnetic layer 43 is observed using a magnetic force microscope (MFM) to obtain an MFM image. A Digital Instruments Dimension3100 and its analysis software are used as the MFM. The measurement area of ​​the MFM image is set to 10 μm × 10 μm, and this 10 μm × 10 μm measurement area is divided into 512 × 512 (= 262,144) measurement points. Measurements are performed using MFM on three different 10 μm × 10 μm measurement areas, thus obtaining three MFM images. From the three obtained MFM images, the track width is measured at 10 locations using the analysis software included with the Dimension3100, and the average value (simple average) is taken. This average value is the data track width W. The measurement conditions for the above MFM were: sweep speed: 1 Hz, chip used: MFMR-20, lift height: 20 nm, and correction: Flatten order 3.

[0106] The minimum value L of the magnetization reversal distance is determined as follows: A magnetic tape MT with data recorded across its entire surface is prepared, and the data recording pattern of the data band DB portion of the magnetic layer 43 is observed using a magnetic force microscope (MFM) to obtain an MFM image. A Digital Instruments Dimension3100 and its analysis software are used as the MFM. The measurement area of ​​the MFM image is set to 2 μm × 2 μm, and this 2 μm × 2 μm measurement area is divided into 512 × 512 (= 262,144) measurement points. Measurements are performed using MFM on three different 2 μm × 2 μm measurement areas, i.e., three MFM images are obtained. Fifty inter-bit distances are measured from the two-dimensional relief chart of the recording pattern of the obtained MFM image. These inter-bit distance measurements are performed using the analysis software included with the Dimension3100. The value that is approximately the greatest common divisor of the 50 measured inter-bit distances is taken as the minimum value L of the magnetization reversal distance. The measurement conditions were: sweep speed: 1 Hz, chip used: MFMR-20, lift height: 20 nm, correction: Flatten order 3.

[0107] A servo pattern is a magnetized region formed by a servo writer magnetizing a specific region of the magnetic layer 43 in a specific direction during magnetic tape manufacturing. Regions of the servo band SB where a servo pattern is not formed (hereinafter referred to as "non-pattern regions") may be magnetized regions where the magnetic layer 43 is magnetized, or non-magnetized regions where the magnetic layer 43 is not magnetized. If the non-pattern regions are magnetized regions, the servo pattern formation regions and non-pattern regions may be magnetized in different directions (e.g., opposite directions). LPOS (Longitudinal Position Of Signal) information is embedded in the servo pattern (servo signal). LPOS information indicates the longitudinal position of the magnetic tape MT and is longitudinal position information for uniquely identifying each servo band SB.

[0108] Figure 5 is an enlarged view showing an example of the configuration of a servo band SB. In the LTO standard, the servo band SB has a servo pattern formed on it consisting of multiple servo stripes (linear magnetized regions) 113 that are inclined with respect to the width direction of the magnetic tape MT.

[0109] The servo band SB includes multiple servo frames 110. Each servo frame 110 consists of 18 servo stripes 113. Specifically, each servo frame 110 consists of a servo subframe 1 (111) and a servo subframe 2 (112).

[0110] The servo subframe 1(111) consists of an A-burst 111A and a B-burst 111B. The B-burst 111B is positioned adjacent to the A-burst 111A. The A-burst 111A has five servo stripes 113 that are inclined at a predetermined angle φ with respect to the width direction of the magnetic tape MT and are formed at predetermined intervals. In Figure 5, these five servo stripes 113 are labeled A1, A2, A3, A4, and A5, indicating their arrangement from the EOT (End Of Tape) to the BOT (Beginning Of Tape) of the magnetic tape MT. The B-burst 111B, similar to the A-burst 111A, has five servo stripes 113 that are inclined at a predetermined angle φ with respect to the width direction of the magnetic tape MT and are formed at predetermined intervals. In Figure 5, these five servo stripes 113 are labeled B1, B2, B3, B4, and B5, indicating their arrangement from the EOT to the BOT of the magnetic tape MT. The servo stripe 113 of the B-burst 111B is tilted in the opposite direction to the servo stripe 113 of the A-burst 111A. In other words, the servo stripe 113 of the A-burst 111A and the servo stripe 113 of the B-burst 111B are arranged in a V-shape.

[0111] The servo subframe 2 (112) consists of a C-burst 112C and a D-burst 112D. The D-burst 112D is positioned adjacent to the C-burst 112C. The C-burst 112C has four servo stripes 113 that are inclined at a predetermined angle φ with respect to the tape width direction and are formed at predetermined intervals. In Figure 5, these four servo stripes 113 are labeled C1, C2, C3, and C4 from the EOT to the BOT of the magnetic tape MT. The D-burst 112D, similar to the C-burst 112C, has four servo stripes 113 that are inclined at a predetermined angle φ with respect to the tape width direction and are formed at predetermined intervals. In Figure 5, these four servo stripes 113 are labeled D1, D2, D3, and D4 from the EOT to the BOT of the magnetic tape MT. The servo stripe 113 of the D-burst 112D is tilted in the opposite direction to the servo stripe 113 of the C-burst 112C. In other words, the servo stripe 113 of the C-burst 112C and the servo stripe 113 of the D-burst 112D are arranged in a V-shape.

[0112] The predetermined angle φ of the servo stripe 113 in A burst 111A, B burst 111B, C burst 112C, and D burst 112D is, for example, 5° to 25°, and in particular, it can be 11° to 25°.

[0113] By reading the servo band SB with the magnetic head 51, information for obtaining the tape speed and the longitudinal position of the magnetic head can be obtained. The tape speed is calculated from the time between four timing signals (A1-C1, A2-C2, A3-C3, A4-C4). The head position is calculated from the time between the aforementioned four timing signals and the time between another four timing signals (A1-B1, A2-B2, A3-B3, A4-B4).

[0114] As shown in Figure 5, it is preferable that the servo pattern (i.e., the multiple servo stripes 113) is arranged linearly in the longitudinal direction of the magnetic tape MT. In other words, it is preferable that the servo band SB is linear in the longitudinal direction.

[0115] Figure 6 is a schematic diagram showing an example of a magnetic tape MT format. The magnetic tape MT is divided into seven regions along its longitudinal direction by eight logical points LP0 to LP7. LP0 to LP7 are set in this order from one end of the magnetic tape MT near the winding end to the other end near the winding beginning. In addition, the magnetic tape MT is divided in the width direction into five or more servo bands and four or more data bands. Figure 6 shows an example where the magnetic tape MT is divided in the width direction into five servo bands and four data bands.

[0116] The seven regions consist of the unused region (the region between LP0 and LP1) R1, the forward servo recognition region (the region between LP1 and LP2) R2, the calibration region (the region between LP2 and LP3) R3, the user data region (the region between LP3 and LP4) R4, the unused data region (the region between LP4 and LP5) R5, the reverse servo recognition region (the region between LP5 and LP6) R6, and the unused region (the region between LP6 and LP7) R7. In the following explanation, the servo recognition region R2, the calibration region R3, the user data region R4, the unused data region R5, and the reverse servo recognition region R6 will be collectively referred to as the "used region."

[0117] In this specification, “forward direction” means the direction in which the magnetic tape MT is fed out of the cartridge 10 and wound up by a reel such as a servo writer. “Reverse direction” means the direction in which the magnetic tape MT is fed out of a reel such as a servo writer and wound up onto the cartridge 10.

[0118] The operating area has a servo pattern that meets the standard. The servo pattern that meets the standard is the distance D between A burst 111A and C burst 112C. AC and the distance D between C burst 112C and A burst 111A CAThis meets the standard. In this case, as shown in Figure 7A, the tips of B burst 111B and C burst 112C separate, and the tips of D burst 112D and A burst 111A separate. This forms a V-shaped servo pattern. The servo pattern shown in Figure 5 is an example of a servo pattern that meets the standard formed in the operating area.

[0119] Both unused areas R1 and R7 have servo patterns that do not meet the standard. These non-compliant servo patterns may be formed in part of unused area R1 or in all of it. Similarly, these non-compliant servo patterns may be formed in part of unused area R7 or in all of it. As described above, unused area R1 is located at the winding end of the magnetic tape MT, and unused area R7 is located at the winding beginning end of the magnetic tape MT.

[0120] A servo pattern that does not meet the standard will have a distance of D between, for example, A burst 111A and C burst 112C. AC and the distance D between C burst 112C and A burst 111A CA It is either narrower than the standard or wider than the standard.

[0121] When the magnetic tape MT is traveling in the forward direction, the unused region R1 becomes the region where the magnetic tape MT is accelerated. Therefore, if the servo signal is written using the same control as in the used region, the distance D between A burst 111A and C burst 112C will be AC and the distance D between C burst 112C and A burst 111A CA It will be narrower than the standard.

[0122] When the magnetic tape MT is traveling in the forward direction, the unused area R7 becomes the area where the magnetic tape MT travels at a reduced speed. Therefore, when servo signals are written using the same control as in the used area, the distance D between A burst 111A and C burst 112C becomes AC and the distance D between C burst 112C and A burst 111A CAIt will be narrower than the standard.

[0123] Distance D AC and distance D CA If the width is narrower than the standard, for example, as shown in Figure 7B, the tips of B-burst 111B and C-burst 112C will overlap, forming a V-shaped servo pattern with B-burst 111B and C-burst 112C. Also, the tips of D-burst 112D and A-burst 111A will overlap, forming a V-shaped servo pattern with D-burst 112D and A-burst 111A.

[0124] Distance D AC and distance D CA If the width is even narrower than the standard, for example, as shown in Figure 7C, the B-burst 111B and C-burst 112C intersect, forming an X-shaped servo pattern. Also, the D-burst 112D and A-burst 111A intersect, forming an X-shaped servo pattern.

[0125] Whether or not non-compliant servo patterns are formed in unused areas R1 and R7 can be confirmed as follows. First, the cartridge 10 is disassembled and the magnetic tape MT is removed. Next, the servo patterns (i.e., servo bands SB) formed on the magnetic layer 43 of unused areas R1 and R7 of the removed magnetic tape MT are observed using a magnetic force microscope (MFM) to obtain an MFM image. A Digital Instruments Dimension3100 and its analysis software are used as the MFM. Next, it is confirmed whether or not the servo patterns in the obtained MFM image comply with the specifications. Alternatively, after applying a ferricolloid developer (Sigma Marker Q, manufactured by Sigma Hi-Chemical Co., Ltd.), confirmation is also possible using a microscope at approximately 100 to 1000x magnification.

[0126] In conventional cartridges, servo signals that meet the standards are written to the unused areas at the beginning and end of the winding. This is because, in the manufacturing process of conventional cartridges, a magnetic tape with a servo pattern that meets the standards written from one end to the other in the longitudinal direction is assembled into the cartridge, and no process is performed to rewrite the servo signals after assembly.

[0127] [4. Configuration of a servo writer for cartridges] Figure 8 is a schematic diagram showing an example of the configuration of a servo writer 210 for a cartridge. The servo writer 210 erases the servo signals written to the cartridge 10 and rewrites the servo signals. This rewriting of the servo signals creates a servo pattern (second servo pattern) that does not meet the standard in the unused areas R1 and R7 mentioned above.

[0128] The servo writer 210 includes a cartridge housing 211, a reel 212, guide rollers 213A, 213B, 213C, 213D, a demagnetizing magnet 214, a servo signal writing head 215, a verify head 216, a control device 217, a pulse generation circuit 218, a spindle drive circuit 219A, a reel drive circuit 219B, and an operating unit (not shown).

[0129] The running section is comprised of a cartridge housing 211, a reel 212, and guide rollers 213A, 213B, 213C, and 213D. When writing a servo signal, this running section feeds out a tape-shaped magnetic tape MT from the cartridge 10 and winds the fed-out magnetic tape MT onto the reel 212, thereby running the magnetic tape MT in the forward direction. After writing the servo signal, this running section feeds out a tape-shaped magnetic tape MT from the reel 212 and winds the fed-out magnetic tape MT onto the cartridge 10, thereby running the magnetic tape MT in the reverse direction. In the following description, "running path" refers to the path along which the magnetic tape MT runs in the servo writer 210. Also, "upstream side" and "downstream side" refer to the upstream and downstream sides of the running path when the magnetic tape MT is running in the forward direction.

[0130] (Cartridge storage section) The cartridge housing 211 is configured to accommodate the cartridge 10. The cartridge housing 211 is equipped with a loading mechanism (not shown) and is configured to load the cartridge 10. The cartridge housing 211 feeds out the magnetic tape MT for rewriting the servo signals. The cartridge housing 211 is equipped with a spindle 241A. The spindle 241A is configured to accommodate the cartridge 10. The magnetic tape MT is fed out by the rotation of the spindle 241A.

[0131] (reel) Reel 212 winds up the magnetic tape MT from which the servo signal has been rewritten. Reel 212 is configured to secure the leading edge (leader pin 20) of the magnetic tape MT as it is pulled out from cartridge 10.

[0132] (Guide roller) Guide rollers 213A and 213B are provided in the travel path between the cartridge housing 211 and the servo signal writing head 215. Guide rollers 243A and 243B guide the magnetic tape MT as it travels from the cartridge housing 211 toward the servo signal writing head 215. Guide rollers 243C and 243D are provided in the travel path between the servo signal writing head 215 and the reel 212. Guide rollers 243C and 243D guide the travel of the magnetic tape MT as it travels from the servo signal writing head 215 toward the reel 212.

[0133] (Demagnetizing magnet) The demagnetizing magnet 214 is located upstream of the servo signal writing head 215 in the travel path. The demagnetizing magnet 214 erases the servo pattern (first servo pattern) formed on the magnetic tape MT as it travels in the forward direction. The demagnetizing magnet 214 may be rotatable, as shown in Japanese Patent Application Publication No. 2018-005970, and may be a magnet capable of changing the magnetic field applied to the magnetic layer 43 in accordance with the rotation.

[0134] (Servo signal writing head) The servo signal writing head 215 is a magnetic head for rewriting the servo signal onto a forward-moving magnetic tape from which the servo pattern has been erased, thereby forming a servo pattern (a second servo pattern). As the servo signal writing head 215, for example, the one described in Patent Document 1 can be used.

[0135] The servo signal writing head 215 has a sliding surface that slides against the magnetic tape MT. The servo signal writing head 215 has five or more recording elements and at least one bottomed cavity (recess) on the sliding surface. The recording elements have magnetic gaps. Multiple magnetic gaps are arranged in a line on the sliding surface at predetermined intervals to correspond to the position of each servo band in the width direction of the magnetic tape MT. Each of the five or more recording elements writes a servo signal to the magnetic tape MT, thereby forming five or more servo bands SB.

[0136] The bottomed cavity is enclosed, and the cavity is formed only within the width of the magnetic tape MT's travel area. By providing a bottomed cavity with this configuration on the sliding surface, the expansion of air between the sliding surface and the magnetic tape MT is promoted during the travel of the magnetic tape MT, resulting in a decrease in air pressure, i.e., negative pressure, which reduces spacing and improves the travel stability of the magnetic tape MT.

[0137] (Verify head) The verify head 216 is located downstream of the servo signal writing head 215 in the travel path. The verify head 216 is a magnetic head that slides against the forward-traveling magnetic tape MT on which the servo signal is written, and reads the servo signal written on the servo band SB. The configuration of the verify head 216 can be the same as that of the servo signal writing head 215, except that it has multiple playback elements instead of multiple recording elements.

[0138] (Control device) The control device 217 is a device that controls the operation of each part of the servo writer 210 and is equipped with a CPU (Central Processing Unit) and various storage devices. The control device 217 controls the servo signal writing head 215 to write servo signals during the acceleration and deceleration periods of the magnetic tape MT, thereby forming a servo pattern on the magnetic tape MT that does not meet the standards. The control device 217 also controls the servo signal writing head 215 to write servo signals during the constant speed period of the magnetic tape MT, thereby forming a servo pattern on the magnetic tape MT that meets the standards.

[0139] The control device 217 generates pulse control signals to control the current value, pulse width, and generation timing of the recording pulse current so that the servo signals written to the magnetic tape MT by the servo signal writing head 215 conform to a specified servo pattern, and supplies these signals to the pulse generation circuit 218.

[0140] The control device 217 checks whether the servo signal is properly recorded on the magnetic tape MT based on the servo signal supplied from the verify head 216. Specifically, the control device 217 stores information about the servo signal that meets the standard (hereinafter referred to as "standard information") in a memory device, compares this standard information with the servo signal supplied from the verify head 216, and checks whether the servo signal is properly recorded on the magnetic tape MT.

[0141] The control device 217 erases the servo signals written to the magnetic tape MT by moving the demagnetizing magnet 214 and bringing it into contact with the magnetic tape MT.

[0142] The control device 217 controls the spindle drive circuit 219A to rotate the spindle 211A. The control device 217 also controls the reel drive circuit 219B to rotate the reel 212. Specifically, in order to control the travel speed of the magnetic tape MT when writing servo signals, the control device 217 generates motor current signals to control the motor current of the spindle drive circuit 219A and the reel drive circuit 219B and supplies them to the spindle drive circuit 219A and the reel drive circuit 219B.

[0143] (Operation unit) The control unit is used to operate the servo writer 210 and perform servo programming operations, etc. The control unit is connected to the control device 217.

[0144] (Pulse generation circuit) The pulse generation circuit 218 generates a recording pulse current based on the pulse control signal supplied from the control device 217 and supplies it to the servo signal writing head 215.

[0145] (Spindle drive circuit) The spindle drive circuit 219A rotates the spindle 211A based on the control of the control device 217. The spindle drive circuit 219A is a device for rotating the spindle 211A and includes a motor integrated with the spindle 211A, and a motor drive circuit for supplying current to this motor. In the spindle drive circuit 219A, a motor current is generated in the motor drive circuit based on the motor current signal supplied from the control device 217, and this motor current is supplied to the motor to rotate the spindle 211A.

[0146] (Reel drive circuit) The reel drive circuit 219B rotates the reel 212 based on the control of the control device 217. The reel drive circuit 219B is a device for rotationally driving the reel 212 and includes a motor, a motor drive circuit for supplying current to the motor, and gears for connecting the motor shaft and the reel 212. In the reel drive circuit 219B, a motor current is generated in the motor drive circuit based on the motor current signal supplied from the control device 217, and this motor current is supplied to the motor, thereby transmitting the rotational driving force of the motor to the reel 212 via the gears and rotating the reel 212.

[0147] [5. Operation of the servo writer for cartridges] The following describes an example of the operation of the servo writer 210 having the above configuration.

[0148] First, the operator loads the cartridge 10 into the cartridge housing 211. After loading, the operator pulls out the magnetic tape MT from the cartridge 10, and its tip (leader pin 20) is fixed to the reel 212. Note that the cartridge 10 housed in the cartridge housing 211 may be one in which the magnetic tape MT has been confirmed to have a quality defect.

[0149] Next, when an operator operates an operating unit (not shown), the control device 217 brings the demagnetizing magnet 214 into contact with the magnetic tape MT. The control device 217 controls the rotation of the spindle 211A and reel 212 via the spindle drive circuit 219A and reel drive circuit 219B to feed the magnetic tape from the cartridge 10 and wind the fed-out magnetic tape MT onto the reel 212. This causes the magnetic tape MT to accelerate forward. The demagnetizing magnet 214 erases the servo pattern (i.e., the servo signal written to the magnetic tape MT) formed on the magnetic tape MT as it travels forward.

[0150] Next, during the acceleration period of the magnetic tape MT, the control device 217 uses the demagnetizing magnet 214 to erase the servo pattern (i.e., the servo signal written to the magnetic tape MT) formed in the unused area R1 of the magnetic tape MT as it travels in the forward direction. Next, during the acceleration period of the magnetic tape MT, the control device 217 controls the servo signal writing head 215 to write a servo signal, thereby forming a servo pattern that does not meet the standard in the unused area R1 of the magnetic tape as it travels in the forward direction.

[0151] Next, once the magnetic tape MT reaches a specified travel speed, the control device 217 controls the rotation of the spindle 211A and reel 212 via the spindle drive circuit 219A and the reel drive circuit 219B to cause the magnetic tape MT to travel in the forward direction at a specified constant speed.

[0152] Next, during a period of constant-speed travel of the magnetic tape MT, the control device 217 uses the demagnetizing magnet 214 to erase the servo pattern (i.e., the servo signal written to the magnetic tape MT) formed in the usable area of ​​the magnetic tape MT traveling in the forward direction. Then, during a period of constant-speed travel of the magnetic tape MT, the control device 217 uses the servo signal writing head 215 to rewrite the servo signal to the usable area of ​​the magnetic tape MT traveling in the forward direction, forming a servo pattern that meets the specifications. The servo signal includes LPOS information, and when the servo signal is rewritten, the LPOS information is also written to the servo band SB.

[0153] Next, during the period when the magnetic tape MT is traveling at a constant speed, the control device 217 reads the servo signal from the magnetic tape MT traveling in the forward direction using the verify head 216, and checks whether the servo signal has been properly written based on the read servo signal.

[0154] Next, once a specified length of magnetic tape MT has been wound onto the cartridge 10, the control device 217 controls the rotation of the spindle 211A and reel 212 via the spindle drive circuit 219A and the reel drive circuit 219B, causing the magnetic tape MT to travel in the forward direction at a reduced speed.

[0155] Next, during the deceleration period of the magnetic tape MT, the control device 217 uses the demagnetizing magnet 214 to erase the servo pattern (i.e., the servo signal written to the magnetic tape MT) formed in the unused area R7 of the magnetic tape MT that is traveling in the forward direction. Then, during the deceleration period of the magnetic tape MT, the control device 217 controls the servo signal writing head 215 to write a servo signal, and forms a servo pattern that does not meet the standard in the unused area R7 of the magnetic tape that is traveling in the forward direction.

[0156] Next, once all of the magnetic tape MT stored in the cartridge 10 has been fed out, the control device 217 stops the rotational drive of the spindle 211A and reel 212 via the spindle drive circuit 219A and reel drive circuit 219B. This stops the movement of the magnetic tape MT. Next, the control device 217 stops the demagnetization function by moving the demagnetizing magnet 214 away from the magnetic tape MT. Next, the control device 217 controls the rotation of the spindle 211A and reel 212 via the spindle drive circuit 219A and reel drive circuit 219B to feed out the magnetic tape MT from the reel 212, and the fed-out magnetic tape MT is wound up by the cartridge 10.

[0157] Next, once the magnetic tape MT that was wound on the reel 212 has been completely fed out and wound onto the cartridge 10, the control device 217 stops the rotational drive of the spindle 211A and the reel 212 via the spindle drive circuit 219A and the reel drive circuit 219B. After that, the control device 217 unloads the cartridge 10 from the cartridge housing 211 in response to the operation of the control unit.

[0158] [6. Configuration of the Servo Signal Recording System] Figure 9 is a schematic diagram showing an example of the configuration of a servo signal recording system. The servo signal recording system comprises a servo writer 220 for pancakes, a winder 230, a quality inspection device 240, and a servo writer 210 for cartridges. Here, "pancake" refers to a roll of magnetic tape MT (winding body of magnetic tape MT) before it is cut to a specified length.

[0159] As described above, the servo writer 210 for cartridges is as described, so below we will describe the servo writer 210 for pancakes, the winder 230, and the quality inspection device 240.

[0160] (Servo writer for pancakes) Figure 10 is a schematic diagram showing an example of the configuration of a servo writer 220 for pancakes. The servo writer 220 is configured to write servo signals to a magnetic tape MT used as a pancake.

[0161] The servo writer 220 comprises reels 221 and 212, guide rollers 213A, 213B, 213C, and 213D, a demagnetizing magnet 214, a servo signal writing head 215, a verifying head 216, a control device 222, a pulse generation circuit 218, a reel drive circuit 219C, a reel drive circuit 219B, and an operating unit (not shown). Note that parts of the servo writer 220 that are the same as those of the servo writer 210 are denoted by the same reference numerals and their descriptions are omitted.

[0162] Reel 221 is configured to accommodate a magnetic tape MT as a pancake. Reel 221 feeds out the magnetic tape MT for writing servo signals.

[0163] The control device 222 controls the rotation of reels 212 and reels 212 via reel drive circuits 219C and 219B, causing the magnetic tape MT to travel in the forward direction at a specified constant speed. The control device 222 may control the servo signal writing head 215 so as not to write servo signals during the acceleration and deceleration periods of the magnetic tape MT, or it may control the servo signal writing head 215 to write servo signals. However, unlike the control device 217, the control device 222 does not have a function to travel the magnetic tape MT in the reverse direction.

[0164] The control unit is used to operate the servo writer 220 and perform servo programming operations, etc. The control unit is connected to the control device 222.

[0165] (winder) Figure 11 is a schematic diagram showing an example of the configuration of the winder 230. The winder 230 incorporates a magnetic tape MT on which servo signals are written into a cartridge case 12. The winder 230 includes a reel 231, a guide roller 232, a cartridge housing 211, a control device 233, a spindle drive circuit 219A, and an operating unit (not shown). In the winder 230, the same reference numerals are used for parts that are the same as those in the servo writer 210, and their explanation is omitted.

[0166] Reel 231 is configured to accommodate a magnetic tape MT as a pancake, on which servo signals are written. Reel 231 feeds out the magnetic tape MT for writing the servo signals. Guide rollers 232 are provided in the travel path between reel 231 and cartridge housing 211. Guide rollers 232 guide the magnetic tape MT as it travels from reel 231 toward cartridge housing 211. Control device 233 controls spindle drive circuit 219A to rotate spindle 211A. This causes the magnetic tape MT to be fed out from reel 231 and wound up by cartridge 10.

[0167] The control unit is used to operate the winder 230 and perform operations such as winding the magnetic tape MT. The control unit is connected to the control device 233.

[0168] (Quality inspection equipment) The quality inspection device 240 inspects the quality of the servo signal of the magnetic tape MT incorporated in the cartridge case 12. Examples of servo signal quality defects include missing servo signals and poor servo tracking characteristics.

[0169] [7. Operation of the servo signal recording system] The following describes an example of the operation of a servo signal recording system having the above configuration.

[0170] (Servo signal writing process) A servo signal is written to the magnetic tape MT, which has been cut to a specified width, using the servo writer 220 as follows. First, the operator mounts the magnetic tape MT as a pancake onto the reel 221, pulls out the leading edge of the magnetic tape MT on the outer circumference, and fixes it to the reel 212. Next, when the operator operates an operating unit (not shown), the control device 222 controls the rotation of the reel 212 via the reel drive circuit 219B, feeds the magnetic tape MT from the cartridge 10, and winds the fed-out magnetic tape MT onto the reel 212. As a result, the magnetic tape MT travels in the forward direction.

[0171] Next, the control device 222 erases the forward-moving magnetic tape MT with the demagnetizing magnet 214, and then writes a servo signal to the forward-moving magnetic tape MT with the servo signal writing head 215 to form a servo pattern. Next, the control device 222 reads the written servo signal from the forward-moving magnetic tape MT with the verify head 216, and checks whether the servo signal has been written correctly based on the read servo signal.

[0172] Next, once all the magnetic tape MTs as pancakes have been fed out, the control device 222 stops the rotational drive of the reel 212 via the reel drive circuit 219B. This stops the transport of the magnetic tape MTs. After that, the operator removes the magnetic tape MTs as pancakes, on which the servo signals have been written, from the reel 212 and transports them to the winder 230.

[0173] (Assembly process) The magnetic tape MT on which the servo signal is written is loaded into the cartridge 10 using the winder 230 as follows: First, the operator mounts the magnetic tape MT as a pancake onto the reel 231, and the cartridge 10 is loaded into the cartridge housing 211. Next, the outermost end of the magnetic tape MT mounted on the reel 231 is pulled out and fixed onto the reel 13 of the cartridge 10 (see Figure 1).

[0174] Next, when an operator operates an operating unit (not shown), the control device 233 controls the rotational drive of the spindle 211A via the spindle drive circuit 219A, feeds out the magnetic tape MT from the reel 231, and winds up the fed-out magnetic tape MT with the cartridge 10.

[0175] Next, once the specified length of magnetic tape has been wound onto the cartridge 10, the control device 233 stops the rotation of the spindle 211A via the spindle drive circuit 219A. This stops the transport of the magnetic tape MT. Subsequently, the control device 233 unloads the cartridge 10 from the cartridge housing 211 in response to the operation of the control unit. The unloaded cartridge 10 is then transported by the operator to the quality inspection device 240.

[0176] Furthermore, if a servo pattern that does not meet the standard is formed in a predetermined range from both ends of the longitudinal direction of the magnetic tape MT as a pancake, these parts may be cut and removed from the magnetic tape MT during this assembly process. Alternatively, if no servo pattern is formed in a predetermined range from both ends of the longitudinal direction of the magnetic tape MT as a pancake, these parts may be cut and removed from the magnetic tape MT during this assembly process.

[0177] (Quality inspection process) The quality of the servo signal of the magnetic tape MT incorporated into the cartridge 10 is inspected using the quality inspection device 240. If no quality defects are found in the magnetic tape MT as a result of the inspection, the cartridge 10 is shipped. On the other hand, if quality defects are found in the magnetic tape MT as a result of the inspection, the cartridge 10 is transported to the servo writer 210. Then, the servo signal is rewritten to the magnetic tape MT through the "servo signal rewriting process" described later, and a servo pattern (i.e., servo band SB) is formed. After the servo signal has been rewritten, the quality of the servo signal of the magnetic tape MT incorporated into the cartridge 10 is inspected again using the quality inspection device 240.

[0178] If the servo signal quality is still poor after the "servo signal rewriting process" has been repeated a specified number of times (for example, 3 times), the quality inspection device 240 will discard the cartridge 10 by the operator.

[0179] (Servo signal rewriting process) The servo signal is rewritten to the magnetic tape MT of cartridge 10 using the servo writer 210. The details of this process are as described above in [5 Operation of the Servo Writer for Cartridges].

[0180] It is preferable that the quality inspection process is performed after a specified time has elapsed since the magnetic tape MT was installed in the cartridge 10. That is, it is preferable that the servo signal rewriting is performed after a specified time has elapsed since the magnetic tape MT was installed in the cartridge 10. As described above, by performing the quality inspection, i.e., rewriting the servo signal, after a specified time has elapsed, the servo signal can be recorded on the magnetic tape MT after the width dimension of the magnetic tape MT has stabilized. Therefore, the dimensional change in the spacing of the servo bands SB is reduced. The lower limit of the specified time is preferably 1 day or more, more preferably 3 days or more, and even more preferably 7 days or more. If the lower limit of the specified time is 1 day or more, the width dimension of the magnetic tape MT can be effectively stabilized. The upper limit of the specified time is, for example, 30 days or less or 15 days or less, preferably 7 days or less. If the upper limit of the specified time is 7 days or less, a decrease in productivity can be suppressed.

[0181] After the assembly process and before the quality inspection process, the cartridge 10 may be subjected to annealing. By performing annealing in this manner, the width dimension of the magnetic tape MT is stabilized, and then the servo signal can be recorded on the magnetic tape MT. From the viewpoint of stabilizing the width dimension of the magnetic tape MT, it is preferable to perform the annealing for the above-specified time. The temperature of the annealing is preferably between 23°C and 70°C.

[0182] [8 Effects] As described above, the servo writer 210 according to one embodiment of the present disclosure includes a running unit that feeds out the magnetic tape MT from the cartridge 10 and winds up the fed-out magnetic tape MT to make the magnetic tape MT move, a demagnetizing magnet 214 that erases the first servo pattern formed on the moving magnetic tape MT, a servo signal writing head 215 that writes a servo signal to the moving magnetic tape MT from which the first servo pattern has been erased and forms a second servo pattern, and a control device 217 that controls the servo signal writing head 215 to write the servo signal during both the acceleration and deceleration periods of the magnetic tape MT, thereby forming a second servo pattern on the magnetic tape MT that does not meet the standards. This makes it possible to rewrite the servo signal of a cartridge 10 that has been found to have a quality defect in the servo signal. Therefore, the number of cartridges 10 that are discarded can be reduced. Thus, the productivity of cartridges 10 can be improved.

[0183] In terms of servo signal performance, when reading the servo signal with the drive, two servo signal reading elements (sensors) shown as 51A and 51B (see Figure 3) are used. However, due to the effects of temperature, humidity, and winding pressure inside the cartridge 10, the tape width dimension, or in other words, the spacing between servo bands SB (servo band pitch), usually changes in the direction of widening. As a result, misalignment of the recording / playback elements may occur, potentially making it difficult to read the data track Tk.

[0184] In contrast, as in the embodiment described above, if the servo signal is recorded after the width dimension of the magnetic tape MT has stabilized following winding of the cartridge 10 and storage for a specified time (for example, after several days of storage), the dimensional change in the spacing of the servo bands SB is reduced. Therefore, the misalignment of the recording / playback elements is reduced, the read accuracy of the data track Tk is improved, and high track density can be achieved.

[0185] When running a magnetic tape (MT), an acceleration region is required at the unwinding end, and a deceleration region is required at the end of the unwinding. If a recording current pattern at a fixed interval is applied to the acceleration and deceleration regions, a servo pattern that does not meet the specifications will be created. On the other hand, in order to form a servo pattern that meets the specifications, it is necessary to vary the time interval of the recording pattern by synchronizing the feed position of the magnetic tape (MT) with the recording current pattern, which is technically difficult. In the servo writer 210 according to the above embodiment, non-compliant servo patterns are recorded in unused areas R1 and R7, thus avoiding the above-mentioned difficulties. Furthermore, a pulse generation circuit that has been conventionally used in servo writers for pancakes and the like can be used as the pulse generation circuit 218.

[0186] [9 Variations] (Variation 1) In the embodiment described above, a case was explained in which servo signals that do not meet the standard are written to unused areas R1 and R7. However, servo patterns may not be formed in unused areas R1 and R7. In this case, servo patterns may not be formed in part of unused area R1, or not in all of it. Similarly, servo patterns may not be formed in part of unused area R7, or not in all of it.

[0187] The unused areas R1 and R7 described above are formed as follows when the servo writer 210 rewrites the servo signal. The control device 217 controls the servo signal writing head 215 so as not to write the servo signal during the acceleration and deceleration periods when the magnetic tape MT is running in the forward direction.

[0188] As described above, by ensuring that no servo patterns are formed in unused areas R1 and R7, it becomes unnecessary to manufacture a pulse generation circuit that allows for variable recording pulse time synchronized with the tape feed position, which is technically impossible. This makes it possible to use the conventionally used pulse generation circuit as pulse generation circuit 218.

[0189] (Modification 2) It is also possible to have a servo signal that does not meet the standard written to one of the unused areas R1 and R7, while the other area does not have a servo signal written to it.

[0190] The unused areas R1 and R7 described above are formed as follows when the servo signal is rewritten by the servo writer. The control device 217 controls the servo signal writing head 215 to write the servo signal during one of the acceleration and deceleration periods when the magnetic tape MT is run in the forward direction, thereby forming a servo pattern that does not meet the standard on the magnetic tape MT. Conversely, during the other period, the control device 217 controls the servo signal writing head 215 not to write the servo signal, thereby not forming a servo pattern on the magnetic tape MT.

[0191] (Variation 3) In the above-described embodiment, the case in which the servo writer 210 for the cartridge is used to rewrite the servo signal was explained, but the servo writer 210 for the cartridge may also be used to write the servo signal for the first time. In this case, it is preferable that the initial writing of the servo signal is performed after a specified time has elapsed since the magnetic tape MT was installed in the cartridge 10. It is preferable to perform an annealing treatment on the cartridge 10 after the installation process and before the quality inspection process. From the viewpoint of stabilizing the width dimension of the magnetic tape MT, it is preferable to perform the annealing treatment for the specified time mentioned above.

[0192] While embodiments and modifications of the present disclosure have been described in detail above, the present disclosure is not limited to the embodiments and modifications described above, and various modifications are possible based on the technical idea of ​​the present disclosure. For example, the configurations, methods, processes, shapes, materials, and numerical values ​​given in the embodiments and modifications described above are merely examples, and different configurations, methods, processes, shapes, materials, and numerical values ​​may be used as needed. The configurations, methods, processes, shapes, materials, and numerical values ​​of the embodiments and modifications described above can be combined with each other as long as they do not deviate from the spirit of the present disclosure.

[0193] The chemical formulas of compounds exemplified in the above embodiments and modifications are representative examples, and are not limited to the stated valencies, etc., as long as they are the same compound's common name. In the numerical ranges described stepwise in the above embodiments and modifications, the upper or lower limit of one step in the numerical range may be replaced with the upper or lower limit of another step in the numerical range. Unless otherwise specified, the materials exemplified in the above embodiments and modifications can be used individually or in combination of two or more.

[0194] Furthermore, this disclosure may also adopt the following configuration. (1) A traveling unit that feeds a tape-shaped magnetic recording medium from a cartridge and winds up the fed-out magnetic recording medium, thereby moving the magnetic recording medium, An erasing unit for erasing a first servo pattern formed on the moving magnetic recording medium, A head that writes a servo signal to the moving magnetic recording medium, from which the first servo pattern has been erased, and forms a second servo pattern, A control unit controls the head to write the servo signal during at least one of the acceleration and deceleration periods of the magnetic recording medium, and forms a second servo pattern that does not meet the standard on the magnetic recording medium. A servo writer equipped with the following features. (2) A traveling unit that feeds a tape-shaped magnetic recording medium from a cartridge and winds up the fed-out magnetic recording medium, thereby moving the magnetic recording medium, An erasing unit for erasing a first servo pattern formed on the moving magnetic recording medium, A head that writes a servo signal to the moving magnetic recording medium, from which the first servo pattern has been erased, and forms a second servo pattern, A control unit controls the head so as not to write the servo signal during at least one of the acceleration and deceleration periods of the magnetic recording medium. A servo writer equipped with the following features. (3) The head is a servowriter according to (1) or (2) having five or more recording elements. (4) Each of the five or more recording elements writes the servo signal to the magnetic recording medium, thereby forming five or more servo bands. The servo signal includes information for uniquely identifying each of the servo bands, as described in (3). (5) A wound tape-shaped magnetic recording medium, A case for housing the magnetic recording medium and Equipped with, The aforementioned magnetic recording medium has an unused area, The unused area of ​​the cartridge may have a servo pattern that does not meet the standard, or may not have a servo pattern formed therein. (6) The aforementioned unused area is A first unused area provided on the winding end side of the magnetic recording medium, A second unused area provided on the winding start side of the magnetic recording medium and The cartridge described in (5) is equipped with the following. (7) The magnetic recording medium is a cartridge according to (5) or (6) having 5 or more servo bands. (8) The cartridge according to (7), wherein the five or more servo bands include information for uniquely identifying each of the servo bands. (9) The magnetic recording medium comprises a magnetic layer, The cartridge according to any one of (5) to (8), wherein the aspect ratio of the magnetic layer in the vertical direction is 65% or more. (10) The magnetic layer contains magnetic powder, The cartridge according to (9), wherein the magnetic powder comprises hexagonal ferrite, ε-iron oxide, or Co-containing spinel ferrite. (11) The process of incorporating a tape-shaped magnetic recording medium into a cartridge, After a specified time has elapsed since the magnetic recording medium was incorporated into the cartridge, a servo pattern is formed on the magnetic recording medium. How to write a servo pattern that includes [this]. (12) Forming the servo pattern on the magnetic recording medium is A method for writing a servo pattern according to (11), comprising controlling a head to write a servo signal during at least one of the acceleration period and the deceleration period of the magnetic recording medium, thereby forming a servo pattern that does not meet the standards on the magnetic recording medium. (13) Forming the servo pattern on the magnetic recording medium is The magnetic recording medium is moved by feeding it out of the cartridge and winding up the fed-out magnetic recording medium. To erase the first servo pattern formed on the moving magnetic recording medium, The servo signal is written by the head to the moving magnetic recording medium from which the first servo pattern has been erased, thereby forming a second servo pattern. Includes, Forming the two servo patterns mentioned above is A method for writing a servo pattern according to (11), comprising controlling the head to write the servo signal during at least one of the acceleration period and the deceleration period of the magnetic recording medium, thereby forming a second servo pattern that does not meet the standard on the magnetic recording medium. (14) The process of incorporating a tape-shaped magnetic recording medium into a cartridge, After a specified time has elapsed since the magnetic recording medium was incorporated into the cartridge, a servo pattern is formed on the magnetic recording medium. A method for manufacturing cartridges containing [the specified ingredient]. (15) Forming the servo pattern on the magnetic recording medium is A method for manufacturing a cartridge according to (14), comprising controlling the head to write a servo signal during at least one of the acceleration period and the deceleration period of the magnetic recording medium, thereby forming a servo pattern that does not meet the standards on the magnetic recording medium. (16) Forming the servo pattern on the magnetic recording medium is The magnetic recording medium is moved by feeding it out of the cartridge and winding up the fed-out magnetic recording medium. To erase the first servo pattern formed on the moving magnetic recording medium, The servo signal is written by the head to the moving magnetic recording medium from which the first servo pattern has been erased, thereby forming a second servo pattern. Includes, Forming the two servo patterns mentioned above is A method for manufacturing a cartridge according to (14), comprising controlling the head to write the servo signal during at least one of the acceleration period and the deceleration period of the magnetic recording medium, thereby forming the second servo pattern that does not meet the standard on the magnetic recording medium. [Explanation of symbols]

[0195] 10 Cartridge 11 Cartridge Memory 12 Cartridge Case 41 Substrate 42 Underlayer 43 Magnetic Layer 44 Back Layer 110 Servo Frame 111 Servo Sub-Frame 1 111A A Burst 111B B Burst 112 Servo Sub-Frame 2 112C C Burst 112D D Burst 113 Servo Strip 210, 220 Servo Writer 211 Cartridge Accommodation Section 211A Spindle 212 Reel 213A, 213B, 213C, 213D Guide Roller 214 Demagnetizing Magnet 215 Servo Signal Writing Head 216 Verification Head 217 Control Device 218 Pulse Generation Circuit 219A Spindle Drive Circuit 219B, 219C Reel Drive Circuit 230 Winders 240 Quality Inspection Device MT Magnetic Tape SB Servo Band DB Data Bind

Claims

1. A wound tape-shaped magnetic recording medium, A case having a reel capable of winding the magnetic recording medium and housing the magnetic recording medium Equipped with, A pin is provided at one end of the outer circumference of the magnetic recording medium. The magnetic recording medium has a plurality of servo bands extending in the longitudinal direction of the magnetic recording medium and a plurality of data bands extending in the longitudinal direction of the magnetic recording medium. Between adjacent servo bands in the width direction of the magnetic recording medium, the data band is provided. The servo band has an unused region, The unused area is provided in the portion that is not fixed to the pin and the reel. In the aforementioned unused area, a servo pattern that does not meet the standard is formed. cartridge.

2. A wound tape-shaped magnetic recording medium, A case having a reel capable of winding the magnetic recording medium and housing the magnetic recording medium Equipped with, A pin is provided at one end of the outer circumference of the magnetic recording medium. The magnetic recording medium has a plurality of servo bands extending in the longitudinal direction of the magnetic recording medium and a plurality of data bands extending in the longitudinal direction of the magnetic recording medium. Between adjacent servo bands in the width direction of the magnetic recording medium, the data band is provided. The servo band has a first unused area, a used area, and a second unused area in this order, extending from one end of the magnetic recording medium towards the other end of the magnetic recording medium towards the winding end. The first unused area and the second unused area are provided in the portion not fixed to the pin and the reel. No servo patterns are formed in the first unused area and the second unused area. cartridge.

3. The aforementioned unused area is A first unused area provided on the winding end side of the magnetic recording medium, A second unused area provided on the winding start side of the magnetic recording medium and Equipped with, The cartridge according to claim 1.

4. The magnetic recording medium has five or more servo bands, The cartridge according to claim 1 or 2.

5. The servo band includes information for uniquely identifying each of the servo bands. The cartridge according to claim 1 or 2.

6. The aforementioned magnetic recording medium is A long, rectangular base, A base layer provided on the first main surface of the substrate, A magnetic layer provided on the aforementioned base layer, The substrate comprises a back layer provided on the second main surface of the substrate, The cartridge according to claim 1 or 2.

7. The average thickness of the substrate is 4.2 μm or less. The cartridge according to claim 6.

8. The aforementioned substrate contains polyester, The cartridge according to claim 6.

9. The substrate comprises at least one of polyamide, polyimide, and polyamideimide. The cartridge according to claim 6.

10. The aspect ratio of the magnetic layer in the vertical direction is 65% or more. The cartridge according to claim 6.

11. The average thickness of the magnetic layer is 80 nm or less. The cartridge according to claim 6.

12. The magnetic layer contains magnetic powder, The magnetic powder includes hexagonal ferrite, ε-iron oxide, or Co-containing spinel ferrite. The cartridge according to claim 6.

13. The magnetic layer contains magnetic powder, The magnetic powder includes barium ferrite or strontium ferrite. The cartridge according to claim 6.

14. The barium ferrite further contains at least one of Sr, Pb, and Ca in addition to Ba. The strontium ferrite further comprises at least one of Ba, Pb, and Ca in addition to Sr. The cartridge according to claim 13.

15. The average thickness of the magnetic recording medium is 5.6 μm or less. The cartridge according to claim 1 or 2.

16. The servo pattern that does not meet the standard has multiple servo bursts, The servo pattern that does not meet the standard is formed such that the leading edges of adjacent servo bursts in the longitudinal direction of the magnetic recording medium overlap. The cartridge according to claim 1.

17. The servo pattern that does not meet the standard has multiple servo bursts, The servo pattern that does not meet the standard is formed such that adjacent servo bursts intersect in the longitudinal direction of the magnetic recording medium. The cartridge according to claim 1.

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