Magnetic tape drive and method of operating a magnetic tape drive

Abstract

To provide a magnetic tape drive and a method of operating the magnetic tape drive in which friction generated between the magnetic tape and a support member is suppressed as compared with a case where the support member provided on the opposite side of the magnetic head with the magnetic tape interposed therebetween is directly pressed to the magnetic tape.SOLUTION: A magnetic tape drive includes: a first magnetic head having a first magnetic element acting on a magnetic layer formed on a first surface of a magnetic tape; a first support member arranged at a position facing the first magnetic head with the magnetic tape interposed therebetween and facing a second surface opposite to the first surface of the magnetic tape; and an air film forming device for forming an air film between the magnetic tape and the first support member.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] TECHNICAL FIELD The disclosed technology relates to magnetic tape drives and methods of operating magnetic tape drives. [Background technology]

[0002] Patent Document 1 describes a magnetic tape device in which air is blown from an air blowing member onto the back side of a magnetic tape opposite the front side, and the magnetic tape is floated by the air and faces a magnetic head.

[0003] Non-Patent Document 1, based on previously reported contact slider design theory, newly evaluates the adhesive contact characteristics of a TFC (Thermal Flying Height Control) head slider due to the surface force between the head and disk using the JKR (Johnson-Kendall-Robert) theory, clarifies the contact vibration characteristics of a contact head slider due to micro-waviness of the disk, and proposes design conditions for stable contact. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] U.S. Patent No. 8,054,582 [Non-patent literature]

[0005] [Non-Patent Document 1] Kyosuke Ono, "Design Theory and Contact Vibration Characteristics of Contact Head Sliders," Transactions of the Japan Society of Mechanical Engineers, Series C, Vol. 79, No. 797 (2013), pp. 90-106 Summary of the Invention

[0006] One embodiment of the technology disclosed herein provides a magnetic tape drive and a method of operating a magnetic tape drive in which friction between the magnetic tape and a support member is reduced compared to when the support member, located on the opposite side of the magnetic tape from the magnetic head, is pressed directly against the magnetic tape. [Means for solving the problem]

[0007] A first aspect of the technology disclosed herein is a magnetic tape drive comprising a first magnetic head having a first magnetic element that acts on a magnetic layer formed on a first surface of a magnetic tape, a first support member that is positioned facing the first magnetic head across the magnetic tape and faces a second surface, which is the surface opposite the first surface of the magnetic tape, and an air film forming device that forms an air film between the magnetic tape and the first support member.

[0008] A second aspect of the technology disclosed herein is a magnetic tape drive according to the first aspect, in which the air film forming device is a first ultrasonic vibration source that forms an air film between the magnetic tape and the first support member by ultrasonically vibrating the first support member in a direction perpendicular to the longitudinal direction of the magnetic tape and perpendicular to the width direction of the magnetic tape.

[0009] A third aspect of the technique of the present disclosure is the magnetic tape drive according to the second aspect, in which the air film is a squeeze film.

[0010] A fourth aspect of the technology disclosed herein is a magnetic tape drive according to the second aspect, in which the first ultrasonic vibration source vibrates the first support member at a frequency that generates a squeeze film between the magnetic tape and the first support member, and the vibration frequency is greater than the natural frequency of the magnetic tape.

[0011] A fifth aspect of the disclosed technology is a magnetic tape drive according to any one of the second to fourth aspects, wherein the first ultrasonic vibration source vibrates the first support member at a frequency that causes the amplitude of the magnetic tape to fall within a predetermined range.

[0012] A sixth aspect of the technology of the present disclosure is a magnetic tape drive according to any one of the second to fifth aspects, wherein the magnetic tape drive further comprises a processor, and the processor controls the operation of the first ultrasonic vibration source based on magnetic tape information, which is information about the magnetic tape.

[0013] A seventh aspect of the technique of the present disclosure is the magnetic tape drive according to the sixth aspect, wherein the magnetic tape information includes information on the transport state of the magnetic tape and / or information on the properties of the magnetic tape.

[0014] An eighth aspect of the technology of the present disclosure is a magnetic tape drive according to the seventh aspect, in which the information relating to the transport state of the magnetic tape includes information about the speed at which the magnetic tape is transported, information about the tension occurring in the magnetic tape, and / or information about the amplitude of the magnetic tape.

[0015] A ninth aspect of the technology of the present disclosure is a magnetic tape drive according to the seventh aspect, in which the information regarding the properties of the magnetic tape includes information regarding the thickness of the magnetic tape and / or information regarding the material of the magnetic tape.

[0016] A tenth aspect of the disclosed technology is a magnetic tape drive according to any one of the seventh to ninth aspects, wherein the magnetic tape drive further includes a sensor that detects the transport state of the magnetic tape, and the processor controls the operation of the first ultrasonic vibration source based on the detection result of the sensor.

[0017] An eleventh aspect of the disclosed technology is a magnetic tape drive according to any one of the first to tenth aspects, further comprising a leaf spring type suspension supporting a first magnetic head, the first magnetic head being provided at a tip of the suspension, and the suspension displacing the first magnetic head in a direction approaching the magnetic tape.

[0018] A twelfth aspect of the technique of the present disclosure is a magnetic tape drive according to any one of the first to eleventh aspects, further comprising a position adjustment actuator that adjusts the position of the first magnetic head along a direction perpendicular to the longitudinal direction of the magnetic tape and perpendicular to the width direction of the magnetic tape.

[0019] A thirteenth aspect of the technology of the present disclosure is a magnetic tape drive according to any one of the first to twelfth aspects, in which the magnetic tape has a magnetic layer also formed on its second side, and further comprises a second magnetic head having a second magnetic element that acts on the magnetic layer formed on the second side, a second support member that is positioned facing the second magnetic head across the magnetic tape and faces the first side, and an air film forming device that forms an air film between the magnetic tape and the second support member, and switches between a first state in which the first magnetic element acts on the magnetic layer on the first side and a second state in which the second magnetic element acts on the magnetic layer on the second side.

[0020] A fourteenth aspect of the technology of the present disclosure is a magnetic tape drive according to any one of the first to twelfth aspects, wherein the magnetic tape has a magnetic layer formed on its second side as well, and further comprises a second magnetic head having a second magnetic element that acts on the magnetic layer formed on the second side, a second support member that is positioned facing the second magnetic head across the magnetic tape and faces the first side, and an air film forming device that forms an air film between the magnetic tape and the second support member, wherein the second magnetic head and the second support member are positioned at different positions in the longitudinal direction of the magnetic tape from the first magnetic head and the first support member, respectively.

[0021] A fifteenth aspect of the technology of the present disclosure is a method of operating a magnetic tape drive, which includes forming an air film between the magnetic tape and a support member that is positioned facing the magnetic head across the magnetic tape, running the magnetic tape with the air film formed, and acting the magnetic head on the magnetic layer of the magnetic tape. [Brief explanation of the drawings]

[0022] [Figure 1]FIG. 1 illustrates an example of a schematic configuration of a magnetic tape drive. [Figure 2] FIG. 1 is an enlarged view showing an example of a schematic configuration of a magnetic tape drive. [Figure 3] FIG. 10 is a plan view of the support member as seen from the side of the delivery head and the rewind head. [Figure 4] FIG. [Figure 5] FIG. 2 is a diagram showing the correspondence between data elements and data tracks. [Figure 6] FIG. 2 is an enlarged view of a data element. [Figure 7] FIG. 2 is a block diagram showing an example of the configuration of a control unit. [Figure 8] FIG. 2 is a block diagram showing an example of the configuration of a control unit. [Figure 9] 10 is a flowchart showing an operation procedure of the magnetic tape drive. [Figure 10] FIG. 2 is a perspective view showing an example of a delivery head. [Figure 11] FIG. 1 is a perspective view showing an example of a piezoelectric bimorph element. [Figure 12] 10A and 10B are side views showing an example of operation of the piezoelectric bimorph element. [Figure 13] FIG. 1 is an enlarged view showing an example of a schematic configuration of a magnetic tape drive. [Figure 14] FIG. 1 is an enlarged view showing an example of a schematic configuration of a magnetic tape drive. [Figure 15] FIG. 1 is an enlarged view showing an example of a schematic configuration of a magnetic tape drive. [Figure 16] FIG. 1 is an enlarged view showing an example of a schematic configuration of a magnetic tape drive. [Figure 17] FIG. 1 is an enlarged view showing an example of a schematic configuration of a magnetic tape drive. DETAILED DESCRIPTION OF THE INVENTION

[0023] [First embodiment] As an example, as shown in Figure 1, a cartridge 11 is loaded into a magnetic tape drive 10. The cartridge 11 contains a cartridge reel 13 around which a magnetic tape 12 is wound. The magnetic tape drive 10 records data on the magnetic tape 12 fed from the cartridge reel 13. The magnetic tape drive 10 also reads the data recorded on the magnetic tape 12. The magnetic tape drive 10 is an example of a "magnetic tape drive" according to the technology of the present disclosure.

[0024] The magnetic tape 12 has a configuration in which, for example, a magnetic layer 16 and a backcoat layer 17 are formed on a base film 15 (see FIG. 2 ). Data is recorded in the magnetic layer 16. The magnetic layer 16 contains ferromagnetic powder. As the ferromagnetic powder, ferromagnetic powders commonly used in the magnetic layers of various magnetic recording media can be used. A preferred example of the ferromagnetic powder is hexagonal ferrite powder. Instead of hexagonal ferrite powder, for example, hexagonal strontium ferrite powder or hexagonal barium ferrite powder can be used. The backcoat layer 17 contains a non-magnetic powder such as carbon black. The base film 15 is also called a support and is made of, for example, polyethylene terephthalate, polyethylene naphthalate, or polyamide. Note that a non-magnetic layer may be formed between the base film 15 and the magnetic layer 16. The magnetic tape 12 is an example of a “magnetic tape” according to the technology of the present disclosure.

[0025] The surface of the magnetic tape 12 on which the magnetic layer 16 is formed is the front surface 18 of the magnetic tape 12. On the other hand, the surface on which the backcoat layer 17 is formed is the back surface 19 of the magnetic tape 12. Note that the front surface 18 is an example of a "first surface" according to the technology of the present disclosure, and the back surface 19 is an example of a "second surface" according to the technology of the present disclosure. Also, the magnetic layer 16 is an example of a "magnetic layer" according to the technology of the present disclosure.

[0026] The magnetic tape drive 10 includes a computer 23 including a processor 20, a memory 21, and a storage 22. The processor 20, the memory 21, and the storage 22 are connected to a bus 24. The memory 21 is, for example, a random access memory (RAM) and temporarily stores various pieces of information. The storage 22 is a computer-readable non-transitory storage medium and stores various parameters and programs. Examples of the storage 22 include a hard disk drive or a solid-state drive. The processor 20 is, for example, a central processing unit (CPU). A control program 22A is stored in the storage 22. The processor 20 operates as a control unit 31 by loading the control program 22A into the memory 21 and executing processing in accordance with the control program 22A. The control unit 31 comprehensively controls the operation of each unit of the magnetic tape drive 10. The processor 20 is an example of a "processor" according to the technology of the present disclosure.

[0027] The magnetic tape drive 10 includes a feed motor 25, a take-up motor 26, a take-up reel 27, a feed head 28, a rewind head 29, and a support member 30. The feed head 28 and the rewind head 29 are examples of a "first magnetic head" according to the technology of the present disclosure. Note that, for ease of explanation, the feed head 28 and the rewind head 29 may be collectively referred to as a "magnetic head" below when there is no need to distinguish between them.

[0028] The supply motor 25 rotates the cartridge reel 13 in the cartridge 11 under the control of the control unit 31. The take-up reel 27 takes up the magnetic tape 12 that has been fed out from the cartridge reel 13. The take-up reel 27 also rewinds the taken-up magnetic tape 12 onto the cartridge reel 13. The take-up motor 26 rotates the take-up reel 27 under the control of the control unit 31.

[0029] The magnetic tape 12 runs in a feed direction FWD or a rewind direction BWD while being guided by a plurality of guide rollers 32 by the drive of the feed motor 25 and the take-up motor 26. The feed direction FWD is the direction from the cartridge reel 13 to the take-up reel 27. The rewind direction BWD is the opposite direction from the take-up reel 27 to the cartridge reel 13. The running speed and tension of the magnetic tape 12 during running are adjusted to appropriate values ​​by adjusting the rotational speed and / or rotational torque of the feed motor 25 and the take-up motor 26, but this is merely one example. For example, the running speed and tension during running may be adjusted to appropriate values ​​by adjusting the rotational speeds of the feed motor 25 and the take-up motor 26 (e.g., the difference in rotation speed between the feed motor 25 and the take-up motor 26).

[0030] The feed head 28 and the rewind head 29 are disposed on the surface 18 side of the magnetic tape 12 to access the magnetic layer 16. The feed head 28 and the rewind head 29 record data on the magnetic layer 16. The feed head 28 and the rewind head 29 also read the data recorded on the magnetic layer 16.

[0031] The feed head 28 operates when the magnetic tape 12 runs in the feed direction FWD. In other words, the feed head 28 operates when the magnetic tape 12 is fed from the cartridge reel 13. In contrast, the rewind head 29 operates when the magnetic tape 12 runs in the rewind direction BWD. In other words, the rewind head 29 operates when the magnetic tape 12 is rewound onto the cartridge reel 13.

[0032] The sending head 28 and the rewinding head 29 have the same structure, but operate at different times. The sending head 28 and the rewinding head 29 are small magnetic heads such as those used in hard disk drives.

[0033] As shown in FIG. 2 as an example, the feed head 28 and the rewind head 29 are provided at the tips of leaf spring suspensions 35 and 36. The base ends of the suspensions 35 and 36 are movably attached to the frame of the magnetic tape drive 10 via, for example, an arm. The suspensions 35 and 36 displace the feed head 28 and the rewind head 29, respectively, in a direction toward the magnetic tape 12. That is, the magnetic heads are pressed against the magnetic tape 12 by the leaf spring suspensions 35 and 36. Meanwhile, a buoyancy force is generated on the magnetic head due to factors such as the shape of the magnetic head in the accompanying flow of the magnetic tape 12. A gap is generated between the magnetic tape 12 and the magnetic head due to the balance between the spring load of the suspensions 35 and 36 on the magnetic head and the buoyancy force of the magnetic head.

[0034] Here, the spring load generated on the magnetic head by the suspensions 35 and 36 is, for example, about 0.01 to 0.1 N, but this is merely one example. As will be described in detail later, it is sufficient that the magnetic tape 12 is kept floating relative to the support member 30, and the spring load may be smaller than 0.01 N or larger than 0.1 N. For example, the spring load changes when the shape of the magnetic head and / or the shape of the suspensions 35 and 36 is changed.

[0035] The suspensions 35 and 36 may retract the feed head 28 and the rewind head 29 to a standby position away from the magnetic tape 12 when the feed head 28 and the rewind head 29 are not in operation.

[0036] Support members 30 are arranged at positions facing the feed head 28 and the rewind head 29 across the magnetic tape 12. Specifically, a feed support member 30A is arranged at a position facing the feed head 28 across the magnetic tape 12. Furthermore, a rewind support member 30B is arranged at a position facing the rewind head 29 across the magnetic tape 12. The feed support member 30A and the rewind support member 30B are examples of "first support members" according to the technology of the present disclosure. Note that, hereinafter, for convenience of explanation, when there is no need to distinguish between the feed support member 30A and the rewind support member 30B, they will also be simply referred to as "support members 30."

[0037] The support member 30 faces the back surface 19 of the magnetic tape 12. Specifically, the support member 30 is a flat plate-shaped member. The portion of the support member 30 facing the back surface of the magnetic tape 12 is flat. The length of the support member 30 in the transport direction of the magnetic tape 12 is not particularly limited, but it need only be long enough to support the magnetic tape 12 to the extent that the magnetic head can read and write to the magnetic tape 12. Furthermore, although an aluminum abrasive is cited as a material for the support member 30, this is merely one example. The material for the support member 30 may be appropriately selected from the viewpoints of rigidity, durability, wear resistance, etc., and may be, for example, a metal other than aluminum, or a resin, etc.

[0038] Incidentally, when the magnetic head is brought into contact with the magnetic tape 12, friction can cause a portion of the magnetic tape 12 to peel off and become debris, which can then adhere to the magnetic head or accumulate on the magnetic tape 12. In order to prevent the generation of this debris, the magnetic head is designed to have a structure similar to that used in a hard disk drive, as described above.

[0039] However, unlike a hard disk drive, the magnetic tape 12 is a more flexible medium than the magnetic disk included in the hard disk drive, and therefore, fluttering (i.e., an increase in amplitude) may occur during transport of the magnetic tape 12. As a result, the gap (i.e., spacing) between the magnetic head and the magnetic tape 12 may fluctuate significantly. One method for suppressing fluttering of the magnetic tape 12 is to support the magnetic head from the back side of the magnetic tape 12 using a guide roller. However, this method supports the magnetic tape 12 on a curved surface, and even a slight change in the position of the magnetic head in the transport direction of the magnetic tape 12 can significantly change the spacing. Furthermore, if the magnetic tape 12 is supported by directly pressing a flat structure against it instead of using a guide roller, friction may occur between the magnetic tape 12 and the structure, which may result in the generation of debris and the risk of unstable running of the magnetic tape 12 due to frictional resistance.

[0040] Therefore, the magnetic tape drive 10 according to the technology of the present disclosure is equipped with an air film forming device 33. The air film forming device 33 forms an air film AM between the support member 30 and the magnetic tape 12. The air film forming device 33 is an example of the "air film forming device" according to the technology of the present disclosure.

[0041] The air film forming device 33 is equipped with ultrasonic vibration sources 33A and 33B. The ultrasonic vibration source 33A is connected to the feeding support member 30A. The ultrasonic vibration source 33B is connected to the rewinding support member 30B. The ultrasonic vibration sources 33A and 33B ultrasonically vibrate the support member 30 in a direction perpendicular to the longitudinal direction of the magnetic tape 12 and perpendicular to the width direction WD of the magnetic tape 12 (i.e., the normal direction ND of the magnetic tape 12). This forms an air film AM between the support member 30 and the magnetic tape 12.

[0042] There are various theories about the levitation of objects using ultrasonic vibrations. One theory states that when two opposing planes approach each other, pressure is generated due to a change in the viscosity of the fluid (e.g., air) present between the planes (i.e., the squeeze effect). As a result, an air film (i.e., a squeeze film) with pressure generated by the squeeze effect is formed. Another theory states that ultrasonic vibrations create an acoustic field between the supporting object and the levitating object (e.g., between the support member 30 and the magnetic tape 12), and the object is levitated due to the difference in sound wave energy density between the top and bottom surfaces of the object (e.g., the front surface 18 and back surface 19 of the magnetic tape 12). In any case, vibration of the ultrasonic vibration sources 33A and 33B forms an air film AM between the supporting member 30 and the magnetic tape 12. The air film AM is, for example, a squeeze film. The ultrasonic vibration sources 33A and 33B are examples of a "first ultrasonic vibration source" according to the technology disclosed herein.

[0043] As a result, when ultrasonic vibrations are applied to the support member 30 from the ultrasonic vibration sources 33A and 33B, a levitation force is generated on the magnetic tape 12 facing the support member 30. One example of the ultrasonic vibration sources 33A and 33B is an ultrasonic vibration source using a piezoelectric element. The piezoelectric element is, for example, lead zirconate titanate (PZT; Pb(Zr,Ti)O3). For example, by applying a voltage of about 10 to 100 V to the piezoelectric element, a levitation height (i.e., the distance between the magnetic tape 12 and the support member 30) of about several tens to several hundreds of nanometers can be obtained. Furthermore, a levitation force of 1 N or more can be generated on the magnetic tape 12. As a result, for example, even when the magnetic head is pressed against the magnetic tape 12 with a force of about 1 N, the magnetic tape 12 can be kept levitated.

[0044] Alternatively, the ultrasonic vibration sources 33A and 33B may be ultrasonic vibration sources using stacked piezoelectric elements. By using stacked piezoelectric elements, it is possible to increase the stroke of the ultrasonic vibration sources. This allows for a greater floating height and a greater distance from the support member 30, thereby enabling the magnetic tape 12 to be transported with reduced influence from the surface condition of the magnetic tape 12 (i.e., unevenness or surface roughness).

[0045] The ultrasonic vibration sources 33A and 33B vibrate the support member 30 by oscillating at a predetermined frequency. For example, the ultrasonic vibration sources 33A and 33B vibrate the support member 30 at a frequency that generates a squeeze film as an air film AM. Furthermore, the ultrasonic vibration sources 33A and 33B vibrate the support member 30 at a frequency higher than the natural frequency of the magnetic tape 12. By vibrating the support member 30 at a frequency equal to or higher than the natural frequency of the magnetic tape 12, the magnetic tape 12 cannot follow the vibration of the support member 30. This suppresses the effect of the vibration of the support member 30 on the magnetic tape 12.

[0046] Furthermore, the ultrasonic vibration sources 33A and 33B vibrate the support member 30 at a frequency that brings the amplitude of the magnetic tape 12 within a predetermined range. The amplitude of the magnetic tape 12 within the predetermined range is preferably within a range equal to or less than the spacing between the magnetic head and the magnetic tape 12, for example, 1 nanometer or less.

[0047] The ultrasonic vibration sources 33A and 33B are fixed to the magnetic tape drive 10 via fixing members 34A and 34B, respectively. The fixing members 34A and 34B are provided on the sides of the ultrasonic vibration sources 33A and 33B opposite to the sides connected to the support member 30. An example of the fixing members 34A and 34B is a flat metal member. The fixing members 34A and 34B are fixed to the housing (not shown) of the magnetic tape drive 10 by, for example, fastening members (not shown).

[0048] A first movement mechanism 40 is connected to the suspension 35, and a second movement mechanism 41 is connected to the suspension 36. The first movement mechanism 40 moves the feed head 28 together with the suspension 35 in the width direction WD of the magnetic tape 12. Similarly, the second movement mechanism 41 moves the rewind head 29 together with the suspension 36 in the width direction WD of the magnetic tape 12. The first movement mechanism 40 and the second movement mechanism 41 include actuators such as voice coil motors or piezoelectric elements.

[0049] As an example, as shown in FIG. 3 , the feed head 28 and the rewind head 29 are arranged at offset positions in the feed direction FWD and the rewind direction BWD (i.e., the longitudinal direction of the magnetic tape 12) so as not to interfere with each other. The width W_H of the feed head 28 and the rewind head 29 is smaller than the width W_T of the magnetic tape 12. Specifically, the width W_H of the feed head 28 and the rewind head 29 is approximately half the width W_T of the magnetic tape 12. The width W_T of the magnetic tape 12 is, for example, 12.65 mm, and the width W_H of the feed head 28 and the rewind head 29 is, for example, 6.5 mm to 7.0 mm. Incidentally, the depth and height of the feed head 28 and the rewind head 29 are also smaller than the width W_T of the magnetic tape 12, for example, about several mm. Furthermore, the width W_G of the support member 30 is larger than the width W_T of the magnetic tape 12.

[0050] The magnetic layer 16 has three servo bands SB1, SB2, and SB3, and two data bands DB1 and DB2 on which data is recorded. The servo bands SB1 to SB3 and the data bands DB1 and DB2 are formed along the feed direction FWD and the rewind direction BWD. The servo bands SB1 to SB3 are arranged at equal intervals along the width direction WD of the magnetic tape 12. The data band DB1 is arranged between the servo bands SB1 and SB2, and the data band DB2 is arranged between the servo bands SB2 and SB3. In other words, the servo bands SB1 to SB3 and the data bands DB1 and DB2 are arranged alternately along the width direction WD of the magnetic tape 12.

[0051] Servo patterns 50 are recorded on the servo bands SB1 to SB3. The servo patterns 50 are provided, for example, at equal intervals along the feed direction FWD and the rewind direction BWD. Each servo pattern 50 is composed of a pair of linear magnetized regions 51A and 51B that are line-symmetric. The pair of linear magnetized regions 51A and 51B are non-parallel to each other and form a predetermined angle with respect to an imaginary line along the width direction of the magnetic tape 12. The predetermined angle is, for example, 10 degrees. In this case, the angle between the magnetized region 51A and the imaginary line along the width direction of the magnetic tape 12 is 5 degrees, and the angle between the magnetized region 51B and the imaginary line is -5 degrees. The magnetized region 51A is inclined toward the rewind direction BWD, and the magnetized region 51B is inclined toward the feed direction FWD. The servo patterns 50 are used, for example, for servo control. The servo control refers to a control in which the feed head 28 and the rewind head 29 are moved in the width direction WD of the magnetic tape 12 by the first moving mechanism 40 and the second moving mechanism 41.

[0052] The feed head 28 records data on the data band DB1 and reads the data recorded on the data band DB1. The feed head 28 also reads the servo patterns 50 recorded on the servo bands SB1 and SB2. In other words, the feed head 28 is responsible for a first area divided in the width direction WD of the magnetic tape 12. In this case, the first area is the servo bands SB1 and SB2 and the data band DB1.

[0053] In contrast, the rewind head 29 records data on the data band DB2 and reads the data recorded on the data band DB2. The rewind head 29 also reads the servo patterns 50 recorded on the servo bands SB2 and SB3. In other words, the rewind head 29 is responsible for a second area divided in the width direction WD of the magnetic tape 12. In this case, the second area is the servo bands SB2 and SB3 and the data band DB2.

[0054] In this way, the feed head 28 is responsible for recording data onto the data band DB1 and reading the data recorded on the data band DB1. The rewind head 29 is responsible for recording data onto the data band DB2 and reading the data recorded on the data band DB2. In other words, two magnetic heads are provided for the two data bands DB1 and DB2.

[0055] As an example, as shown in FIG. 4, the sending head 28 has a magnetic element unit MEU consisting of multiple magnetic elements on the surface facing the magnetic layer 16. The multiple magnetic elements act on the magnetic layer 16. The sending head 28 causes the magnetic elements to magnetically act on the magnetic layer 16 by contacting or bringing the magnetic elements close to the magnetic layer 16. Note that "close" here refers to maintaining a gap, called spacing, between the magnetic layer 16 and the magnetic elements on the order of, for example, several nanometers. Note that the magnetic elements are an example of a "first magnetic element" according to the technology of the present disclosure.

[0056] The magnetic element unit MEU has two servo pattern read elements SR1 and SR2 and eight data elements DRW1, DRW2, DRW3, DRW4, DRW5, DRW6, DRW7, and DRW8. In the following, unless there is a particular need to distinguish between them, the servo pattern read elements SR1 and SR2 will be collectively referred to as the servo pattern read element SR, and the data elements DRW1 to DRW8 will be collectively referred to as the data element DRW.

[0057] The servo pattern read element SR1 is provided at a position corresponding to the servo band SB1, and the servo pattern read element SR2 is provided at a position corresponding to the servo band SB2. The data elements DRW1 to DRW8 are provided between the servo pattern read elements SR1 and SR2. The data elements DRW1 to DRW8 are arranged at equal intervals along the width direction WD of the magnetic tape 12. The data elements DRW1 to DRW8 simultaneously record and / or read data on eight data tracks DT1, DT2, DT3, DT4, DT5, DT6, DT7, and DT8. In the following, unless there is a need to particularly distinguish between them, the data tracks DT1, DT2, DT3, DT4, DT5, DT6, DT7, and DT8 will be referred to as "data tracks DT."

[0058] As an example, as shown in Fig. 5, the data track DT has divided data track groups DTG. The data tracks DT1 to DT8 shown in Fig. 4 correspond to the divided data track groups DTG1 to DTG8 shown in Fig. 5. In the following, unless there is a need to particularly distinguish between them, the divided data track groups DTG1 to DTG8 will be referred to as "divided data track groups DTG."

[0059] The divided data track group DTG1 is a set of divided data tracks obtained by dividing the data track DT in the width direction WD. In the example shown in Figure 5, divided data tracks DT1_1, DT1_2, DT1_3, DT1_4, ..., DT1_11, and DT1_12 are shown as an example of the divided data track group DTG1 obtained by dividing the data track DT into 12 equal parts in the width direction WD. The data element DRW1 is responsible for magnetic processing of the divided data track group DTG1. In other words, the data element DRW1 is responsible for recording data to the divided data tracks DT1_1, DT1_2, DT1_3, DT1_4, ..., DT1_11, and DT1_12, and for reading data from the divided data tracks DT1_1, DT1_2, DT1_3, DT1_4, ..., DT1_11, and DT1_12.

[0060] Like the data element DRW1, each of the data elements DRW2 to DRW8 also performs magnetic processing on the divided data track group DTG of the data track DT corresponding to each data element DRW.

[0061] The data element DRW shifts to a position corresponding to a designated one of the 12 divided data tracks as the first moving mechanism 40 moves the delivery head 28 in the width direction WD. The data element DRW is held at the position corresponding to the designated one data track DT by servo control using the servo pattern 50.

[0062] 6, the data element DRW includes a data recording element DW and a data reading element DR. The data recording element DW records data on the data track DT. The data reading element DR reads the data recorded on the data track DT.

[0063] The data recording element DW is arranged upstream in the forward direction FWD, and the data reading element DR is arranged downstream in the forward direction FWD, so that the data recorded by the data recording element DW can be immediately read by the data reading element DR for error checking.

[0064] Although not shown in the drawings or described in detail, the rewind head 29 also has two servo pattern read elements SR corresponding to the servo bands SB2 and SB3, and eight data elements DRW provided between the two servo pattern read elements SR. The data elements DRW record and / or read data on the 96 data tracks DT of the data band DB2. The data elements DRW include a data recording element DW arranged upstream in the rewind direction BWD and a data reading element DR arranged downstream in the rewind direction BWD.

[0065] As an example, as shown in FIG. 7, the control unit 31 functions as a travel control unit 60, a first position detection unit 61, a first servo control unit 62, a first data acquisition unit 63, a first recording control unit 64, a first reading control unit 65, a first data output unit 66, a second position detection unit 67, a second servo control unit 68, a second data acquisition unit 69, a second recording control unit 70, a second reading control unit 71, and a second data output unit 72.

[0066] The running control unit 60 controls the driving of the delivery motor 25 and the take-up motor 26 to run the magnetic tape 12 in the delivery direction FWD or the rewind direction BWD. The running control unit 60 also adjusts the rotation speed and rotation torque of the delivery motor 25 and the take-up motor 26 to adjust the running speed of the magnetic tape 12 and the tension during running to appropriate values.

[0067] A servo signal based on the servo pattern 50 read by the servo pattern reading element SR of the feed head 28 is input to the first position detection unit 61. The servo signal is an intermittent pulse corresponding to the magnetized regions 51A and 51B. Based on the pulse interval of this servo signal, the first position detection unit 61 detects the position of the servo pattern reading element SR in the width direction WD of the servo band SB, i.e., the position of the feed head 28 in the width direction WD relative to the magnetic tape 12. The first position detection unit 61 outputs the detection result of the position of the feed head 28 in the width direction WD to the first servo control unit 62.

[0068] Two servo signals based on the servo pattern 50 read by the two servo pattern reading elements SR are input to the first position detection unit 61. The first position detection unit 61 calculates the average value of the pulse intervals of the two servo signals. Then, based on the calculated average value, the position of the delivery head 28 in the width direction WD is detected.

[0069] The first servo control unit 62 compares the detection result of the position of the send head 28 from the first position detection unit 61 with the target position of the send head 28. If the detection result is the same as the target position, the first servo control unit 62 does nothing. If the detection result is deviated from the target position, the first servo control unit 62 outputs a servo control signal to the first movement mechanism 40 to set the position of the send head 28 to the target position. The first movement mechanism 40 operates in response to the servo control signal to set the position of the send head 28 to the target position. The target position is stored in the storage 22, for example, in the form of a data table (i.e., a target position table) in which values ​​corresponding to each of the data tracks DT1 to DT8 are registered.

[0070] The first data acquisition unit 63 acquires data to be recorded on the data band DB1 by the feed head 28, for example, by reading it from a host computer (not shown) connected to the magnetic tape drive 10. The first data acquisition unit 63 outputs the data acquired from the host computer to the first recording control unit 64.

[0071] The first recording control unit 64 encodes the data input from the first data acquisition unit 63 into a digital signal for recording. Then, the first recording control unit 64 causes a pulse current corresponding to the digital signal to flow through the data recording element DW of the delivery head 28, causing the data recording element DW to record the data on a specified data track DT in the data band DB1.

[0072] The first read control unit 65 controls the operation of the data reading element DR of the delivery head 28 to cause the data reading element DR to read data recorded on a specified data track DT in the data band DB1. The data read by the data reading element DR is a pulsed digital signal. The first read control unit 65 outputs this pulsed digital signal to the first data output unit 66.

[0073] The first data output unit 66 decodes the pulse-like digital signal from the first data reading control unit 31 into data. For example, the first data output unit 66 outputs the data to a host computer.

[0074] The second position detection unit 67, second servo control unit 68, second data acquisition unit 69, second recording control unit 70, second reading control unit 71, and second data output unit 72 have the same functions as the first position detection unit 61, first servo control unit 62, first data acquisition unit 63, first recording control unit 64, first reading control unit 65, and first data output unit 66, except that the feeding head 28 in the above description is replaced with the rewinding head 29, and the data band DB1 is replaced with the data band DB2. Therefore, detailed description thereof will be omitted.

[0075] 8, the control unit 31 functions as a first vibration source control unit 81 and a second vibration source control unit 82. The first vibration source control unit 81 controls the operation of the ultrasonic vibration source 33A. The second vibration source control unit 82 controls the operation of the ultrasonic vibration source 33B.

[0076] The first vibration source control unit 81 and the second vibration source control unit 82 control the operations of the ultrasonic vibration sources 33A and 33B, respectively, based on magnetic tape information, which is information about the magnetic tape 12. The magnetic tape information includes information about the transport state of the magnetic tape 12 and information about the properties of the magnetic tape 12.

[0077] The information on the transport state of the magnetic tape 12 in the magnetic tape information includes information on the transport speed of the magnetic tape 12, information on the tension occurring in the magnetic tape 12, and information on the amplitude of the magnetic tape 12. In addition, the information on the properties of the magnetic tape 12 in the magnetic tape information includes information on the thickness of the magnetic tape 12 and information on the material of the magnetic tape 12.

[0078] The magnetic tape drive 10 is provided with various sensors. The various sensors detect the transport state of the magnetic tape 12. Specifically, the speed sensor 83 detects the transport speed of the magnetic tape 12 from the rotation speeds of the delivery motor 25 and the take-up motor 26. The speed sensor 83 outputs speed information indicating the speed of the magnetic tape 12 to the control unit 31. Furthermore, the tension sensor 84 detects the tension acting on the magnetic tape 12 from the torque acting on the delivery motor 25 and the take-up motor 26. The tension sensor 84 outputs tension information indicating the tension acting on the magnetic tape 12 to the control unit 31. Furthermore, the displacement sensor 85 detects the amplitude of the magnetic tape 12. The displacement sensor 85 outputs amplitude information indicating the amplitude of the magnetic tape 12 to the control unit 31. The speed sensor 83, the tension sensor 84, and the displacement sensor 85 are examples of "sensors" according to the technology of the present disclosure.

[0079] The first vibration source control unit 81 controls the operation of the ultrasonic vibration source 33A based on the detection results of the speed sensor 83, the tension sensor 84, and the displacement sensor 85. The second vibration source control unit 82 controls the operation of the ultrasonic vibration source 33B based on the detection results of the speed sensor 83, the tension sensor 84, and the displacement sensor 85. For example, when the transport speed of the magnetic tape 12 detected by the speed sensor 83 increases, the first vibration source control unit 81 and the second vibration source control unit 82 operate the ultrasonic vibration sources 33A and 33B to increase the vibration frequency.

[0080] Furthermore, when the tension of the magnetic tape 12 detected by the tension sensor 84 increases, the first vibration source control unit 81 and the second vibration source control unit 82 operate the ultrasonic vibration sources 33A and 33B to increase the vibration frequency. This is because, when the natural frequency of the magnetic tape 12 increases due to an increase in the tension of the magnetic tape 12, the ultrasonic vibration sources 33A and 33B are operated at a frequency equal to or higher than the changed natural frequency. When the ultrasonic vibration sources 33A and 33B vibrate at a frequency equal to or higher than the natural frequency, the magnetic tape 12 cannot follow the vibration of the ultrasonic vibration sources 33A and 33B. This suppresses the effect of the vibration of the ultrasonic vibration sources 33A and 33B on the magnetic tape 12.

[0081] Furthermore, the first vibration source control unit 81 and the second vibration source control unit 82 operate the ultrasonic vibration sources 33A and 33B to increase the vibration frequency when the amplitude of the magnetic tape 12 detected by the displacement sensor 85 increases. In this way, by increasing the vibration frequencies of the ultrasonic vibration sources 33A and 33B when the amplitude of the magnetic tape 12 increases, it is possible to set the frequency range in which the magnetic tape 12 cannot follow the vibrations of the ultrasonic vibration sources 33A and 33B.

[0082] The cartridge 11 is provided with a cartridge memory 11A. The control unit 31 obtains information relating to the properties of the magnetic tape 12 from the cartridge memory 11A. Information relating to the properties of the magnetic tape 12 (for example, the thickness and material of the magnetic tape 12) is stored in the cartridge memory 11A. The control unit 31 obtains the information relating to the properties of the magnetic tape 12 from the cartridge memory 11A via, for example, a non-contact reading and writing device 11B. Under the control of the control unit 31, the non-contact reading and writing device 11B exchanges information with the cartridge memory 11A via a magnetic field.

[0083] The control unit 31 operates the ultrasonic vibration sources 33A and 33B based on information about the properties of the magnetic tape 12 acquired via the non-contact read / write device 11B. For example, the control unit 31 calculates a vibration frequency equal to or higher than the natural frequency of the magnetic tape 12 based on the thickness and material of the magnetic tape 12. The control unit 31 operates the ultrasonic vibration sources 33A and 33B at a vibration frequency equal to or higher than the natural frequency of the magnetic tape 12.

[0084] Furthermore, the information about the magnetic tape 12 may include information such as the manufacturing date, unique manufacturing number, manufacturer, or number of uses of the magnetic tape 12.

[0085] The operation of the above configuration will be described below with reference to the flowchart in Fig. 9. As an example, as shown in Fig. 9, first, in step ST100, the ultrasonic vibration sources 33A and 33B generate ultrasonic vibrations under the control of the first vibration source control unit 81 and the second vibration source control unit 82. As a result, a squeeze film is generated as an air film AM between the back surface 19 of the magnetic tape 12 and the support member 30.

[0086] In the next step ST110, the feed motor 25 and the take-up motor 26 are operated under the control of the travel control unit 60, and the magnetic tape 12 travels in the feed direction FWD or the rewind direction BWD. As a result, the magnetic tape 12 travels with an air layer AM formed between the magnetic tape 12 and the support member 30.

[0087] Then, in step ST120, the magnetic element of the feed head 28 or the rewind head 29 magnetically acts on the magnetic layer 16 of the magnetic tape 12. Specifically, the servo pattern reading element SR reads the servo pattern 50. Furthermore, under the control of the first recording control unit 64 or the second recording control unit 70, the data recording element DW records data on the data track DT. Furthermore, under the control of the first read control unit 65 or the second read control unit 71, the data reading element DR reads data from the data track DT.

[0088] The first position detection unit 61 or the second position detection unit 67 detects the position of the feed head 28 in the width direction WD or the position of the rewind head 29 in the width direction WD from the intervals of the servo signals based on the servo pattern 50. The first servo control unit 62 or the second servo control unit 68 compares the position detection result of the first position detection unit 61 or the second position detection unit 67 with a target position, and performs servo control to position the feed head 28 or the rewind head 29 at the target position.

[0089] As described above, in the magnetic tape drive 10 according to the first embodiment, an air film AM is formed between the magnetic tape 12 and the support member 30. Therefore, with this configuration, friction between the magnetic tape 12 and the support member 30 is suppressed compared to when the support member 30, which is provided on the opposite side of the magnetic tape 12 from the magnetic head, is pressed directly against the magnetic tape 12.

[0090] Furthermore, in the magnetic tape drive 10 according to the first embodiment, the ultrasonic vibration sources 33A and 33B ultrasonically vibrate the support member 30 in a direction perpendicular to the longitudinal direction of the magnetic tape 12 and perpendicular to the width direction WD of the magnetic tape 12. This causes an air layer AM to be formed between the magnetic tape 12 and the support member 30. Therefore, with this configuration, friction between the magnetic tape 12 and the support member 30 is reduced compared to when the air layer AM is formed by a method other than ultrasonic vibration.

[0091] Furthermore, in the magnetic tape drive 10 according to the first embodiment, the air film AM is a squeeze film. Therefore, with this configuration, fluctuations in the gap (i.e., spacing) between the magnetic tape 12 and the support member 30 are suppressed compared to when an air film AM thicker than the squeeze film is formed between the magnetic tape 12 and the support member 30.

[0092] Furthermore, in the magnetic tape drive 10 according to the first embodiment, the ultrasonic vibration sources 33A and 33B vibrate at a frequency equal to or greater than the natural frequency of the magnetic tape 12. Therefore, with this configuration, fluctuations in the gap between the magnetic head and the magnetic tape 12 are suppressed compared to when the ultrasonic vibration sources 33A and 33B vibrate at a frequency less than the natural frequency of the magnetic tape 12.

[0093] Furthermore, in the magnetic tape drive 10 according to the first embodiment, the ultrasonic vibration sources 33A and 33B vibrate the support member 30 at a frequency that keeps the amplitude of the magnetic tape 12 within a predetermined range. Therefore, with this configuration, fluctuations in the gap between the magnetic head and the magnetic tape 12 are suppressed compared to when the ultrasonic vibration sources 33A and 33B vibrate at an amplitude that keeps the amplitude of the magnetic tape 12 outside the predetermined range.

[0094] Furthermore, in the magnetic tape drive 10 according to the first embodiment, the first vibration source control unit 81 and the second vibration source control unit 82 control the ultrasonic vibration sources 33A and 33B, respectively, based on magnetic tape information. Therefore, according to this configuration, the ultrasonic vibration sources 33A and 33B vibrate based on the magnetic tape information, and therefore fluctuations in the gap between the magnetic head and the magnetic tape 12 are suppressed compared to when the magnetic tape information is not taken into consideration.

[0095] Furthermore, in the magnetic tape drive 10 according to the first embodiment, the magnetic tape information includes information about the transport state of the magnetic tape 12 and information about the properties of the magnetic tape 12. Therefore, with this configuration, fluctuations in the gap between the magnetic head and the magnetic tape 12 are suppressed compared to when the transport state of the magnetic tape 12 and the properties of the magnetic tape 12 are not taken into consideration as magnetic tape information.

[0096] Furthermore, in the magnetic tape drive 10 according to the first embodiment, the information relating to the transport state of the magnetic tape 12 includes information relating to the speed at which the magnetic tape 12 is transported, information relating to the tension acting on the magnetic tape 12, and information relating to the amplitude of the magnetic tape 12. Therefore, according to this configuration, fluctuations in the gap between the magnetic head and the magnetic tape 12 are suppressed compared to when the transport state of the magnetic tape 12, the tension acting on the magnetic tape 12, and the amplitude of the magnetic tape 12 are not taken into consideration.

[0097] Furthermore, in the magnetic tape drive 10 according to the first embodiment, the information about the properties of the magnetic tape 12 includes information about the thickness of the magnetic tape 12 and information about the material of the magnetic tape 12. Therefore, according to this configuration, fluctuations in the gap between the magnetic head and the magnetic tape 12 are suppressed compared to when the thickness and material of the magnetic tape 12 are not taken into consideration as properties of the magnetic tape 12.

[0098] Furthermore, the magnetic tape drive 10 according to the first embodiment is provided with a sensor that detects the transport state of the magnetic tape 12, and the operations of the ultrasonic vibration sources 33A and 33B are controlled based on the detection results of the sensor. Therefore, with this configuration, fluctuations in the gap between the magnetic head and the magnetic tape 12 are suppressed compared to when a constant ultrasonic vibration is always generated regardless of the detection result of the transport state of the magnetic tape 12.

[0099] Furthermore, in the magnetic tape drive 10 according to the first embodiment, the magnetic head is displaced by the suspensions 35 and 36 in a direction approaching the magnetic tape 12. Therefore, with this configuration, fluctuations in the gap between the magnetic head and the magnetic tape 12 are suppressed compared to when the position of the magnetic head is always constant.

[0100] In the first embodiment, an example was described in which the information relating to the transport state of the magnetic tape 12 includes information relating to the transport speed of the magnetic tape 12, the tension occurring in the magnetic tape 12, and the amplitude of the magnetic tape 12, but the technology of the present disclosure is not limited to this. For example, the information relating to the transport state of the magnetic tape 12 may be any one or two of information relating to the transport speed of the magnetic tape 12, information relating to the tension occurring in the magnetic tape 12, and information relating to the amplitude of the magnetic tape 12.

[0101] Furthermore, in the first embodiment described above, an example was given in which the information about the properties of the magnetic tape 12 includes information about the thickness of the magnetic tape 12 and information about the material of the magnetic tape 12, but the technology of the present disclosure is not limited to this. For example, the information about the properties of the magnetic tape 12 may be information about the thickness of the magnetic tape 12 or information about the material of the magnetic tape 12.

[0102] Furthermore, in the first embodiment described above, an example was given in which the operations of the ultrasonic vibration sources 33A and 33B are controlled based on the detection results of the speed sensor 83, the tension sensor 84, and the displacement sensor 85. However, the technology of the present disclosure is not limited to this. For example, the operations of the ultrasonic vibration sources 33A and 33B may be controlled based on the detection results of any one or two of the speed sensor 83, the tension sensor 84, and the displacement sensor 85.

[0103] [Second embodiment] In the first embodiment described above, an example was given in which the position of the magnetic head was adjusted by the suspensions 35 and 36, but the technology of the present disclosure is not limited to this. In the second embodiment, an example will be described in which the position of the magnetic head is adjusted by a position adjustment actuator in addition to the suspensions 35 and 36. The magnetic tape drive 10A according to the second embodiment is provided with a position adjustment actuator that adjusts the position of the magnetic head. Note that in the second embodiment, a description of the configuration common to the first embodiment will be omitted.

[0104] As an example, as shown in FIG. 10 , in a magnetic tape drive 10A, the suspension 35 has a load beam 55, a piezoelectric bimorph element 56, and a flexure 57. The load beam 55 is a thin, flat metal plate with relatively high rigidity. The base end of the load beam 55 is attached to a base plate (not shown). The load beam 55 is connected to an actuator (e.g., a voice coil motor) of the movement mechanism 40 via the base plate. The load beam 55 is formed to be slightly shorter in length than the flexure 57. A piezoelectric bimorph element 56 is fixed to the tip of the load beam 55.

[0105] The piezoelectric bimorph element 56 is composed of flat piezoelectric bodies 56A and 56B. The flat piezoelectric bodies 56A and 56B are laminated in the thickness direction and bonded to each other. When a voltage is applied to the piezoelectric bodies 56A and 56B, one expands and the other contracts. The piezoelectric bimorph element 56 is an element that bends due to the expansion and contraction of the piezoelectric bodies 56A and 56B, thereby moving an object. The piezoelectric bodies 56A and 56B are made of, for example, lead zirconate titanate (PZT; Pb(Zr,Ti)O3). The piezoelectric body 56B side of the piezoelectric bimorph element 56 is attached to a flexure 57. The piezoelectric bimorph element 56 is an example of a "position adjustment actuator" according to the technology disclosed herein.

[0106] The flexure 57 is a thin metal plate with relatively low rigidity. Therefore, the flexure 57 functions as a leaf spring. The delivery head 28 is attached to the surface of the flexure 57 opposite to the surface to which the piezoelectric bimorph element 56 is attached.

[0107] 11, the length L_P and width W_P of the piezoelectric bodies 56A and 56B are both several mm, and the thickness T_P of the piezoelectric bodies 56A and 56B is several tens of μm.

[0108] 12, the piezoelectric bimorph element 56 adjusts the position of the magnetic element ME in the normal direction ND by bending the tip of the flexure 57 through the expansion and contraction of the piezoelectric bodies 56A and 56B and moving the feed head 28. In other words, the piezoelectric bimorph element 56 adjusts the position of the feed head 28 along a direction perpendicular to the longitudinal direction of the magnetic tape 12 and perpendicular to the width direction WD of the magnetic tape 12.

[0109] The piezoelectric bimorph element 56 operates to maintain a constant spacing under the control of the control unit 31. Specifically, when the position of the magnetic tape 12 deviates from the normal position shown in the middle of Fig. 12 toward the feed head 28, the piezoelectric bimorph element 56 bends in a direction away from the magnetic tape 12, as shown in the upper part of Fig. 12. On the other hand, when the position of the magnetic tape 12 deviates from the normal position shown in the middle of Fig. 12 in the direction opposite the feed head 28, the piezoelectric bimorph element 56 bends in a direction toward the magnetic tape 12, as shown in the lower part of Fig. 12.

[0110] The bending amount ΔL of the piezoelectric bimorph element 56 in one direction is expressed by the following equation (1): In equation (1), d is the piezoelectric strain constant, and V is the applied voltage.

[0111]

number

[0112] Here, for example, consider a case where the length L_P and width W_P of the piezoelectric bodies 56A and 56B are 1 mm and the thickness T_P is 50 μm. The piezoelectric strain constant d of the piezoelectric bodies 56A and 56B is, for example, 200×10 -12 In m / V, when a voltage of, for example, 20 V is applied to the piezoelectric bodies 56A and 56B, the bending amount ΔL is 1.2 μm according to the formula (1).

[0113] The sending head 28 has a plurality of magnetic elements ME on the surface facing the magnetic layer 16. The plurality of magnetic elements ME magnetically act on the magnetic layer 16. The sending head 28 brings the magnetic elements ME close to the magnetic layer 16 with a spacing on the order of several nanometers, causing the magnetic elements ME to magnetically act on the magnetic layer 16.

[0114] In the second embodiment, the position of the delivery head 28 is adjusted by the piezoelectric bimorph element 56, but the position of the rewinding head 29 is also adjusted by a piezoelectric bimorph element in the same manner.

[0115] 13, a feeding support member 30A is disposed at a position facing the feeding head 28 with the magnetic tape 12 sandwiched therebetween. An ultrasonic vibration source 33A is connected to the feeding support member 30A. The ultrasonic vibration source 33A vibrates the feeding support member 30A in a direction perpendicular to the longitudinal direction of the magnetic tape 12 and perpendicular to the width direction WD of the magnetic tape 12 (i.e., the normal direction ND). As a result, an air layer AM is formed between the magnetic tape 12 and the feeding support member 30A.

[0116] As described above, in the magnetic tape drive 10A according to the second embodiment, the position of the magnetic head is adjusted by the piezoelectric bimorph element 56. Therefore, with this configuration, fluctuations in the gap between the magnetic head and the magnetic tape 12 are suppressed compared to when the position of the magnetic head is always constant.

[0117] That is, the position of the magnetic head is adjusted by the piezoelectric bimorph element 56, thereby reducing the preload applied to the magnetic tape 12. As a result, fluctuations in the gap between the magnetic head and the magnetic tape 12 can be further suppressed compared to when the position of the magnetic head is always constant.

[0118] [Third embodiment] In the first and second embodiments described above, an example was given in which the magnetic layer 16 is provided on the front surface 18 of the magnetic tape 12, but the technology of the present disclosure is not limited to this. In the magnetic tape drive 10B according to the third embodiment, reading and writing to the magnetic tape 12 is achieved even when the magnetic layer 16 is formed not only on the front surface 18 of the magnetic tape 12 but also on the back surface 19. Note that in the third embodiment, a description of the configuration common to the first and second embodiments will be omitted.

[0119] 14, in a magnetic tape drive 10B, a magnetic layer 16 is formed on a front surface 18 of a magnetic tape 12. In addition, a magnetic layer 16 is formed on a back surface 19 of the magnetic tape 12. In other words, the magnetic tape 12 has magnetic layers 16 on both sides.

[0120] The first feed head 28A is arranged on the front surface 18 side of the magnetic tape 12 to access the magnetic layer 16 formed on the front surface 18. The second feed head 28B is arranged on the back surface 19 side of the magnetic tape 12 to access the magnetic layer 16 formed on the back surface 19. The first feed head 28A and the second feed head 28B operate when the magnetic tape 12 runs in the feed direction FWD. The second feed head 28B is an example of a "second magnetic head" according to the technology of the present disclosure.

[0121] A feeding support member 30C is disposed at a position facing the first feeding head 28A across the magnetic tape 12. A feeding support member 30D is disposed at a position facing the second feeding head 28B across the magnetic tape 12.

[0122] The magnetic tape drive 10B includes an air film forming device 33. The air film forming device 33 forms an air film AM between the delivery support members 30C and 30D and the magnetic tape 12. As an example, the air film forming device 33 includes ultrasonic vibration sources 33C and 33D.

[0123] Ultrasonic vibration source 33C is connected to feeding support member 30C. Ultrasonic vibration source 33D is connected to feeding support member 30D. Ultrasonic vibration source 33C is fixed to magnetic tape drive 10B via fixing member 34C. Ultrasonic vibration source 33D is fixed to magnetic tape drive 10B via fixing member 34D.

[0124] The ultrasonic vibration source 33C ultrasonically vibrates the feed support member 30C in a direction perpendicular to the longitudinal direction of the magnetic tape 12 and perpendicular to the width direction WD of the magnetic tape 12 (i.e., the normal direction ND). As a result, an air film AM is formed between the feed support member 30C and the back surface 19 of the magnetic tape 12. Furthermore, the ultrasonic vibration source 33D ultrasonically vibrates the feed support member 30D in the normal direction ND of the magnetic tape 12. As a result, an air film AM is formed between the feed support member 30D and the front surface 18 of the magnetic tape 12.

[0125] The feed head 28B and the feed support member 30D are disposed at positions different from the feed head 28A and the feed support member 30C, respectively, in the longitudinal direction of the magnetic tape 12. In other words, the feed head 28B and the feed support member 30D are disposed on the feed direction BWD side of the feed head 28A and the feed support member 30C, respectively, in the longitudinal direction of the magnetic tape 12.

[0126] As described above, in the magnetic tape drive 10B according to the third embodiment, an air layer AM is formed between the feeding support member 30C and the back surface 19 of the magnetic tape 12. In addition, an air layer AM is formed between the feeding support member 30D and the front surface 18 of the magnetic tape 12. Because the magnetic tape 12 is supported via the air layer AM, even if the magnetic layer 16 is formed on both the front surface 18 and the back surface 19, the influence of friction during transportation on the magnetic layer 16 is suppressed. Therefore, according to this configuration, a magnetic tape drive that can read and write to the magnetic tape 12 is realized even if the magnetic layer 16 is formed on both the front surface 18 and the back surface 19 of the magnetic tape 12.

[0127] [Variations] In the third embodiment described above, an example was given in which the first feeding head 28A and the second feeding head 28B simultaneously act on the magnetic layer 16 of the magnetic tape 12, but the technology of the present disclosure is not limited to this. As an example, as shown in Figure 15, a magnetic tape drive 10C according to this modification can switch between a state in which the first feeding head 28A acts on the magnetic layer 16 on the front surface 18 of the magnetic tape 12 and a state in which the second feeding head 28B acts on the magnetic layer 16 on the back surface 19 of the magnetic tape 12.

[0128] The base ends of the suspensions 35 and 36 are movably attached to the frame of the magnetic tape drive 10 via, for example, arms. In the magnetic tape drive 10C, when the second feed head 28B is not in operation, the second feed head 28B is moved by the second moving mechanism 41 to a standby position separated from the magnetic tape 12. In this case, the ultrasonic vibration source 33D does not generate ultrasonic vibrations, and as a result, no air layer AM is formed between the feed support member 30D and the magnetic tape 12. Meanwhile, the first feed head 28A is displaced in a direction approaching the surface 18 of the magnetic tape 12. Also, an air layer AM is formed between the feed support member 30C and the magnetic tape 12. That is, a first state is realized in which the magnetic element ME of the first feed head 28A acts on the magnetic layer 16 on the surface 18 of the magnetic tape 12.

[0129] On the other hand, as shown in FIG. 16 as an example, when the first feed head 28A is not operating, the first feed head 28A is moved by the first moving mechanism 40 to a standby position separated from the magnetic tape 12. In this case, the ultrasonic vibration source 33C does not generate ultrasonic vibrations, and as a result, an air layer AM is not formed between the feed support member 30C and the magnetic tape 12. On the other hand, the second feed head 28B is displaced in a direction approaching the back surface 19 of the magnetic tape 12. Also, an air layer AM is formed between the feed support member 30D and the magnetic tape 12. That is, a second state is realized in which the magnetic element ME of the second feed head 28B acts on the magnetic layer 16 on the back surface 19 of the magnetic tape 12. The magnetic element ME of the second feed head 28B is an example of a "second magnetic element" according to the technology of the present disclosure.

[0130] In this way, the magnetic tape drive 10C can switch between a state in which the magnetic element ME of the first feed head 28A acts on the magnetic layer 16 on the surface 18 of the magnetic tape 12 and a state in which the magnetic element ME of the second feed head 28B acts on the magnetic layer 16 on the back surface 19 of the magnetic tape 12.

[0131] As described above, in the magnetic tape drive 10C according to this modified example, an air layer AM is formed between the feeding support member 30C and the back surface 19 of the magnetic tape 12. In addition, an air layer AM is formed between the feeding support member 30D and the front surface 18 of the magnetic tape 12. Because the magnetic tape 12 is supported via the air layer AM, even if the magnetic layer 16 is formed on both the front surface 18 and the back surface 19, the influence of friction during transportation on the magnetic layer 16 is suppressed. Therefore, according to this configuration, a magnetic tape drive that can read and write to the magnetic tape 12 is realized even if the magnetic layer 16 is formed on both the front surface 18 and the back surface 19 of the magnetic tape 12.

[0132] Furthermore, the magnetic tape drive 10C according to this modification is switchable between the first state and the second state. Therefore, according to this configuration, even if magnetic layers are formed on both sides of the magnetic tape 12, it is possible to read and write data from only either the front surface 18 or the back surface 19.

[0133] In the above third embodiment and modified example, an example was described in which the first feeding head 28A and the second feeding head 28B act on the front surface 18 and the back surface 19 of the magnetic tape 12, respectively, but the technology of the present disclosure is not limited to this. For example, a similar configuration can be adopted for a rewinding head (not shown). That is, two rewinding heads may be provided that act on the magnetic layer 16 on the front surface 18 and the back surface 19 of the magnetic tape 12, respectively. Furthermore, a rewinding support member (not shown) may be disposed at a position facing the rewinding head with the magnetic tape 12 interposed therebetween, and an air film may be formed between the rewinding support member and the magnetic tape 12.

[0134] In the above-described embodiments, an ultrasonic vibration source is provided as the air film forming device 33, but the technology of the present disclosure is not limited to this. For example, the air film forming device 33 may form an air film AM between the support member 30 and the magnetic tape 12 by injecting air between the support member 30 and the magnetic tape 12. As an example, a plurality of injection ports are provided in a portion of the support member 30 facing the magnetic tape 12. The plurality of injection ports are provided in a dispersed manner in a portion of the support member 30 facing the magnetic tape 12. Air is injected toward the magnetic tape 12 through the plurality of injection ports, thereby forming an air film AM between the support member 30 and the magnetic tape 12.

[0135] Furthermore, in the above-described embodiments, the magnetic heads are provided at the tips of the leaf spring suspensions 35 and 36, but the technology of the present disclosure is not limited to this. As an example, as shown in FIG. 17 , reading and writing to the magnetic tape 12 may be performed by a reading head 90 and a recording head 92. The reading head 90 includes a magnetic element unit 90A and a holder 90B. The magnetic element unit 90A is held by the holder 90B so as to be in proximity to or in contact with the running magnetic tape 12. The magnetic element unit 90A reads data from the magnetic tape 12 and reads servo patterns 50 (see FIG. 3 ) from the magnetic tape 12.

[0136] The recording head 92 includes a magnetic element unit 92A and a holder 92B. The magnetic element unit 92A is held by the holder 92B so as to be in close proximity to or in contact with the running magnetic tape 12. The magnetic element unit 92A records data on the magnetic tape 12 and reads servo patterns 50 (see FIG. 3) from the magnetic tape 12.

[0137] A support member 30 is provided at a position facing the read head 90 and the recording head 92 across the magnetic tape 12. An air film AM is formed between the support member 30 and the magnetic tape 12 by an air film forming device 33.

[0138] Furthermore, the number of servo bands SB, the number of data bands DB, the number of data elements DRW, and the number of DTs carried by one data element DRW shown in each of the above embodiments are merely examples and do not particularly limit the technology of the present disclosure.

[0139] For example, a magnetic tape 12 may be used in which five servo bands SB and four data bands DB are alternately arranged along the width direction WD. In this case, two forward heads and two rewind heads are provided. The width of each magnetic head is approximately 1 / 4 of the width of the magnetic tape 12. The magnetic heads are also positioned at offset positions in the forward direction FWD and the rewind direction BWD so as not to interfere with each other. Support members are respectively positioned opposite each magnetic head across the magnetic tape 12. An air film is formed between the support members and the magnetic tape 12 by an air film forming device.

[0140] Alternatively, a magnetic tape may be used in which nine servo bands SB and eight data bands DB are alternately arranged along the width direction WD. In this case, four feed heads and four rewind heads are provided. The width of the feed heads and rewind heads is approximately 1 / 8 the width of the magnetic tape. Support members are respectively disposed at positions facing each of these magnetic heads across the magnetic tape 12. An air film is formed between the support members and the magnetic tape 12 by an air film forming device.

[0141] Alternatively, a magnetic tape may be used in which 13 servo bands SB and 12 data bands DB are alternately arranged along the width direction WD. In this case, six forward heads and six rewind heads are provided. The width of the forward heads and rewind heads is approximately 1 / 12 of the width of the magnetic tape. Support members are respectively disposed at positions facing each magnetic head across the magnetic tape 12. An air film forming device forms an air film between the support members and the magnetic tape 12.

[0142] Furthermore, in the above embodiments, an example in which the feed head and the rewind head are provided separately has been described, but the technology of the present disclosure is not limited to this. For example, instead of separate feed heads and rewind heads, one magnetic head may be shared for both feed and rewind. Also, one magnetic head may have only one servo pattern read element SR. Similarly, one magnetic head may have only one data element DRW.

[0143] The number of data elements DRW arranged on one magnetic head may be, for example, 16, 32, or 64. Furthermore, the number of data tracks DT on which one data element DRW is responsible for recording and / or reading data is not limited to the example of 12. It may be 1, or may be, for example, 4, 16, 32, or 64.

[0144] Furthermore, while the above embodiments have exemplified the magnetic tape drive 10 into which the cartridge 11 is loaded, the technology of the present disclosure is not limited to this. For example, the magnetic tape drive may be a magnetic tape device in which the magnetic tape 12, not housed in the cartridge 11, is wound around a feed reel, i.e., a magnetic tape device in which the magnetic tape 12 is installed and cannot be replaced.

[0145] In addition, in the above-described embodiments, the magnetic tape 12 has been described as having a magnetic layer 16 containing the exemplified ferromagnetic powder, but the technology of the present disclosure is not limited to this. For example, the magnetic tape may be one in which a ferromagnetic thin film is formed by vacuum deposition such as sputtering.

[0146] Furthermore, in each of the above embodiments, the computer may include, instead of or in addition to the CPU operating as the control unit 31, a programmable logic device (PLD), which is a processor whose circuit configuration can be changed after manufacture, such as an FPGA (Field-Programmable Gate Array), and / or a dedicated electrical circuit, which is a processor having a circuit configuration designed specifically to execute specific processing, such as an ASIC (Application Specific Integrated Circuit).

[0147] The technology of the present disclosure can be appropriately combined with the various embodiments and / or various modified examples described above. Furthermore, it is needless to say that it is not limited to the above embodiments and various configurations can be adopted as long as they do not deviate from the gist of the present disclosure.

[0148] The above-described description and illustrations are a detailed explanation of the parts related to the technology of the present disclosure and are merely an example of the technology of the present disclosure. For example, the above description of the configuration, functions, actions, and effects is an explanation of an example of the configuration, functions, actions, and effects of the parts related to the technology of the present disclosure. Therefore, it goes without saying that unnecessary parts may be deleted, new elements may be added, or replacements may be made to the above-described description and illustrations within the scope of the gist of the technology of the present disclosure. Furthermore, to avoid confusion and facilitate understanding of the parts related to the technology of the present disclosure, the above-described description and illustrations omit explanations of common technical knowledge that do not require particular explanation to enable the implementation of the technology of the present disclosure.

[0149] In this specification, "A and / or B" is synonymous with "at least one of A and B." In other words, "A and / or B" means that it may be only A, only B, or a combination of A and B. Furthermore, in this specification, the same concept as "A and / or B" is also applied when three or more things are expressed connected by "and / or."

[0150] All publications, patent applications, and technical standards mentioned in this specification are herein incorporated by reference to the same extent as if each individual publication, patent application, or technical standard was specifically and individually indicated to be incorporated by reference. [Explanation of symbols]

[0151] 10 Magnetic Tape Drives 11 Cartridges 11A Cartridge Memory 11B Contactless reading and writing device 12 Magnetic Tape 13 Cartridge reel 15 Base Film 16 Magnetic layer 17 Backcourt Layer 18 Surface 19 Back side 20 processors 21 Memory 22 Storage 22A Control Program 23 Computer 24 Bus 25 Feed motor 26 Rewind motor 27 Take-up reel 28 Feed head (first magnetic head) 28A First sending head (first magnetic head) 28B Second delivery head (second magnetic head) 29 Rewind head (first magnetic head) 30 Support member 30A, 30C, 30D Support member for delivery 30B Rewinding support member 31 Control Unit 32 Guide roller 33 Air film forming device 33A, 33B, 33C, 33D Ultrasonic vibration source 34A, 34B, 34C, 34D Fixing members 35, 36 suspension 40 1st movement mechanism 41 Second movement mechanism 50 servo patterns 51A, 51B magnetization area 55 Load beam 56 Piezoelectric bimorph element 56A, 56B Piezoelectric 57 Flexure 60 Travel control unit 61 First position detection unit 62 First servo control unit 63 First Data Acquisition Unit 64 First recording control section 65 First reading control section 66 First data output unit 67 Second position detection unit 68 Second servo control section 69 Second Data Acquisition Unit 70 Second recording control section 71 Second reading control section 72 Second data output unit 81 First vibration source control section 82 Second vibration source control section 83 Speed ​​Sensor 84 Tension sensor 85 Displacement Sensor 90 reading head 90A, 92A magnetic element unit 90B, 92B holder 92 Recording head AM Air Membrane BWD Rewind direction DB Data Band DR Data read element DRW data element DT Data Track DTG divided data track group DW Data recording element FWD Feed direction ME magnetic element SB servo band SR servo pattern reading element Width of WD magnetic tape W_G Width of support member W_H Width of the unwinding head and rewinding head W_T Magnetic tape width

Claims

1. a first magnetic head having a first magnetic element acting on a magnetic layer formed on a first surface of the magnetic tape; a first support member disposed at a position facing the first magnetic head across the magnetic tape and facing a second surface of the magnetic tape opposite the first surface; an air layer forming device that forms an air layer between the magnetic tape and the first support member; Equipped with The air film forming device is a first ultrasonic vibration source that ultrasonically vibrates the first support member in a direction perpendicular to the longitudinal direction of the magnetic tape and perpendicular to the width direction of the magnetic tape, thereby forming the air film between the magnetic tape and the first support member. Magnetic tape drive.

2. The air film is a squeeze film.

10. The magnetic tape drive of claim 1.

3. the first ultrasonic vibration source vibrates the first support member at a frequency at which a squeeze film is generated between the magnetic tape and the first support member; The frequency is higher than the natural frequency of the magnetic tape.

10. The magnetic tape drive of claim 1.

4. The first ultrasonic vibration source vibrates the first support member at a frequency that causes the amplitude of the magnetic tape to fall within a predetermined range.

4. The magnetic tape drive according to claim 1.

5. the magnetic tape drive further comprises a processor; The processor controls the operation of the first ultrasonic vibration source based on magnetic tape information, which is information about the magnetic tape.

5. The magnetic tape drive according to claim 1.

6. The magnetic tape information includes information about the transport state of the magnetic tape and / or information about the properties of the magnetic tape.

6. The magnetic tape drive of claim 5.

7. The information about the transport state of the magnetic tape includes information about the transport speed of the magnetic tape, information about the tension occurring in the magnetic tape, and / or information about the amplitude of the magnetic tape.

7. The magnetic tape drive of claim 6.

8. The information about the properties of the magnetic tape includes information about the thickness of the magnetic tape and / or information about the material of the magnetic tape.

7. The magnetic tape drive of claim 6.

9. the magnetic tape drive further includes a sensor for detecting a transport state of the magnetic tape; The processor controls the operation of the first ultrasonic vibration source based on the detection result of the sensor.

9. The magnetic tape drive according to claim 6.

10. a leaf spring type suspension that supports the first magnetic head; the first magnetic head is provided at a tip of the suspension, The suspension displaces the first magnetic head in a direction toward the magnetic tape.

10. A magnetic tape drive according to claim 1.

11. a position adjustment actuator that adjusts the position of the first magnetic head along a direction perpendicular to the longitudinal direction of the magnetic tape and perpendicular to the width direction of the magnetic tape; 11. A magnetic tape drive according to claim 1.

12. the magnetic tape has a magnetic layer also formed on the second surface; a second magnetic head having a second magnetic element acting on the magnetic layer formed on the second surface; a second support member disposed at a position facing the second magnetic head across the magnetic tape and facing the first surface; an air film forming device that forms an air film between the magnetic tape and the second support member; Further provided with The magnetic tape drive switches between a first state in which the first magnetic element acts on the magnetic layer of the first surface and a second state in which the second magnetic element acts on the magnetic layer of the second surface.

12. A magnetic tape drive according to any one of claims 1 to 11.

13. the magnetic tape has a magnetic layer also formed on the second surface; a second magnetic head having a second magnetic element acting on the magnetic layer formed on the second surface; a second support member disposed at a position facing the second magnetic head across the magnetic tape and facing the first surface; an air film forming device that forms an air film between the magnetic tape and the second support member; Further provided with The second magnetic head and the second support member are disposed at positions different from the first magnetic head and the first support member, respectively, in the longitudinal direction of the magnetic tape.

12. A magnetic tape drive according to any one of claims 1 to 11.

14. forming an air film between the magnetic tape and a support member disposed at a position facing the magnetic head across the magnetic tape; running the magnetic tape in a state where the air film is formed; and Applying the magnetic head to the magnetic layer of the magnetic tape. Including, The air film is formed by ultrasonically vibrating the support member in a direction perpendicular to the longitudinal direction of the magnetic tape and perpendicular to the width direction of the magnetic tape. How magnetic tape drives work.

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