MAGNETIC TAPE DRIVE AND METHOD OF OPERATING MAGNETIC TAPE DRIVE

The magnetic tape drive includes: a first magnetic head that has a first magnetic element acting on a magnetic layer formed on a first surface of a magnetic tape; a first support member that is disposed at a position facing the first magnetic head with the magnetic tape interposed therebetween and faces a second surface which is a surface of the magnetic tape on a side opposite to the first surface; and an air membrane forming device that forms an air membrane between the magnetic tape and the first support member.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority from Japanese Patent Application No. 2021-174998, filed Oct. 26, 2021, the disclosure of which is incorporated herein by reference in its entirety.

BACKGROUND

Technical Field

The technique of the present disclosure relates to a magnetic tape drive and a method of operating a magnetic tape drive.

Related Art

US8054582B discloses a magnetic tape device in which air is blown from an air blowing member onto a back surface of a magnetic tape on a side opposite to a front surface, and the magnetic tape is brought to face a magnetic head in a state of being floated by the air.

In Kyosuke Ono, “Design Theory of Contact Head Slider and Contact Vibration Characteristics”, C Edition of Proceedings of The Japan Society of Mechanical Engineers, Vol. 79, No. 797 (2013), pp. 90 to 106, adsorption contact characteristics of a thermal flying height control (TFC) head slider caused by a surface force between a head and a disk are newly evaluated through Johnson-Kendall-Robert (JKR) theory on the basis of the previously reported design theory of the contact slider, contact vibration characteristics of the contact head slider caused by the minute undulation of the disk are elucidated, and design conditions that enable stable contact are proposed.

SUMMARY

One embodiment according to the technique of the present disclosure provides a magnetic tape drive and a method of operating a magnetic tape drive in which friction is restrained from being generated between a magnetic tape and a support member, as compared with a case where the support member that is provided on a side opposite to a magnetic head with the magnetic tape interposed therebetween is directly pressed against the magnetic tape.

According to a first aspect of the technique of the present disclosure, there is provided a magnetic tape drive comprising: a first magnetic head that has a first magnetic element acting on a magnetic layer formed on a first surface of a magnetic tape; a first support member that is disposed at a position facing the first magnetic head with the magnetic tape interposed therebetween and faces a second surface which is a surface of the magnetic tape on a side opposite to the first surface; and an air membrane forming device that forms an air membrane between the magnetic tape and the first support member.

According to a second aspect of the technique of the present disclosure, in the magnetic tape drive according to the first aspect, the air membrane forming device is a first ultrasonic vibration source that ultrasonically vibrates the first support member in a direction orthogonal to a longitudinal direction of the magnetic tape and orthogonal to a width direction of the magnetic tape to form the air membrane between the magnetic tape and the first support member.

According to a third aspect of the technique of the present disclosure, in the magnetic tape drive according to the second aspect, the air membrane is a squeeze membrane.

According to a fourth aspect of the technique of the present disclosure, in the magnetic tape drive according to the second aspect, the first ultrasonic vibration source vibrates the first support member at a frequency at which a squeeze membrane is generated between the magnetic tape and the first support member, and the frequency is a frequency higher than a natural frequency of the magnetic tape.

According to a fifth aspect of the technique of the present disclosure, in the magnetic tape drive according to any one of the second to fourth aspects, the first ultrasonic vibration source vibrates the first support member at a frequency at which amplitude of the magnetic tape is within a predetermined range.

According to a sixth aspect of the technique of the present disclosure, in the magnetic tape drive according to any one of the second to fifth aspects, a processor is further provided, and the processor controls an operation of the first ultrasonic vibration source on the basis of magnetic tape information which is information regarding the magnetic tape.

According to a seventh aspect of the technique of the present disclosure, in the magnetic tape drive according to the sixth aspect, the magnetic tape information includes information regarding a transport state of the magnetic tape and/or information regarding a property of the magnetic tape.

According to an eighth aspect of the technique of the present disclosure, in the magnetic tape drive according to the seventh aspect, the information regarding the transport state of the magnetic tape includes information regarding a transport speed of the magnetic tape, information regarding tension generated in the magnetic tape, and/or information regarding amplitude of the magnetic tape.

According to a ninth aspect of the technique of the present disclosure, in the magnetic tape drive according to the seventh aspect, the information regarding the property of the magnetic tape includes information regarding a thickness of the magnetic tape and/or information regarding a material of the magnetic tape.

According to a tenth aspect of the technique of the present disclosure, in the magnetic tape drive according to any one of the seventh to ninth aspects, a sensor that detects the transport state of the magnetic tape is further provided, and the processor controls the operation of the first ultrasonic vibration source on the basis of a detection result of the sensor.

According to an eleventh aspect of the technique of the present disclosure, in the magnetic tape drive according to any one of the first to tenth aspects, a leaf spring type suspension that supports the first magnetic head is further provided, the first magnetic head is provided at a distal end portion of the suspension, and the suspension displaces the first magnetic head in a direction approaching the magnetic tape.

According to a twelfth aspect of the technique of the present disclosure, in the magnetic tape drive according to any one of the first to eleventh aspects, a position adjusting actuator that adjusts a position of the first magnetic head along a direction orthogonal to a longitudinal direction of the magnetic tape and orthogonal to a width direction of the magnetic tape is further provided.

According to a thirteenth aspect of the technique of the present disclosure, in the magnetic tape drive according to any one of the first to twelfth aspects, the magnetic tape has a magnetic layer formed on the second surface, a second magnetic head that has a second magnetic element acting on the magnetic layer formed on the second surface, a second support member that is disposed at a position facing the second magnetic head with the magnetic tape interposed therebetween and faces the first surface, and an air membrane forming device that forms an air membrane between the magnetic tape and the second support member are further provided, and the magnetic tape drive switches between a first state in which the first magnetic element acts on the magnetic layer formed on the first surface and a second state in which the second magnetic element acts on the magnetic layer formed on the second surface.

According to a fourteenth aspect of the technique of the present disclosure, in the magnetic tape drive according to any one of the first to twelfth aspects, the magnetic tape has a magnetic layer formed on the second surface, a second magnetic head that has a second magnetic element acting on the magnetic layer formed on the second surface, a second support member that is disposed at a position facing the second magnetic head with the magnetic tape interposed therebetween and faces the first surface, and an air membrane forming device that forms an air membrane between the magnetic tape and the second support member are further provided, and the second magnetic head and the second support member are disposed at different positions from the first magnetic head and the first support member in a longitudinal direction of the magnetic tape, respectively.

According to a fifteenth aspect of the technique of the present disclosure, there is provided a method of operating a magnetic tape drive, comprising: forming an air membrane between a magnetic tape and a support member that is disposed at a position facing a magnetic head with the magnetic tape interposed therebetween; causing the magnetic tape to run in a state in which the air membrane is formed; and causing the magnetic head to act on a magnetic layer of the magnetic tape.

DETAILED DESCRIPTION

First Embodiment

As shown inFIG.1as an example, a cartridge11is loaded in a magnetic tape drive10. A cartridge reel13around which a magnetic tape12is wound is housed in the cartridge11. The magnetic tape drive10records data on the magnetic tape12fed out from the cartridge reel13. Further, the magnetic tape drive10reads the data recorded on the magnetic tape12. The magnetic tape drive10is an example of the “magnetic tape drive” according to the technique of the present disclosure.

The magnetic tape12has, for example, a configuration in which a magnetic layer16and a back coating layer17are formed on a base film15(seeFIG.2). Data is recorded on the magnetic layer16. The magnetic layer16contains ferromagnetic powder. As the ferromagnetic powder, ferromagnetic powder usually used in the magnetic layer of various magnetic recording media can be used. Preferable specific examples of the ferromagnetic powder can include hexagonal ferrite powder. Instead of the hexagonal ferrite powder, for example, hexagonal strontium ferrite powder or hexagonal barium ferrite powder can be used. The back coating layer17contains, for example, non-magnetic powder, such as carbon black. The base film15is also called a support and is formed of, for example, polyethylene terephthalate, polyethylene naphthalate, or polyamide. A non-magnetic layer may be formed between the base film15and the magnetic layer16. The magnetic tape12is an example of the “magnetic tape” according to the technique of the present disclosure.

A surface of the magnetic tape12on which the magnetic layer16is formed is a front surface18of the magnetic tape12. On the other hand, a surface on which the back coating layer17is formed is a back surface19of the magnetic tape12. The front surface18is an example of the “first surface” according to the technique of the present disclosure, and the back surface19is an example of the “second surface” according to the technique of the present disclosure. Further, the magnetic layer16is an example of the “magnetic layer” according to the technique of the present disclosure.

The magnetic tape drive10comprises a computer23that includes a processor20, a memory21, and a storage22. The processor20, the memory21, and the storage22are connected to a bus24. The memory21is, for example, a random access memory (RAM), and temporarily stores various types of information. The storage22is a computer-readable non-transitory storage medium, and stores various parameters and various programs. An example of the storage22includes a hard disk drive or a solid state drive. The processor20is, for example, a central processing unit (CPU). A control program22A is stored in the storage22. The processor20operates as a controller31by loading the control program22A into the memory21and executing processing in accordance with the control program22A. The controller31controls the operation of each unit of the magnetic tape drive10in an integrated manner. The processor20is an example of the “processor” according to the technique of the present disclosure.

The magnetic tape drive10comprises a feeding motor25, a winding-up motor26, a wind-up reel27, a feed head28, a rewind head29, and a support member30. The feed head28and the rewind head29are an example of the “first magnetic head” according to the technique of the present disclosure. Hereinafter, for convenience of description, in a case where it is not necessary to distinguish between the feed head28and the rewind head29, the feed head28and the rewind head29may be collectively referred to as “magnetic head”.

The feeding motor25rotates the cartridge reel13provided in the cartridge11under the control of the controller31. The magnetic tape12fed out from the cartridge reel13is wound up on the wind-up reel27. Further, the magnetic tape12wound up on the wind-up reel27is rewound on the cartridge reel13. The winding-up motor26rotates the wind-up reel27under the control of the controller31.

The magnetic tape12runs in a feed direction FWD or a rewind direction BWD while being guided by a plurality of guide rollers32, by the drive of the feeding motor25and the winding-up motor26. The feed direction FWD is a direction from the cartridge reel13toward the wind-up reel27. The rewind direction BWD is, on the contrary, a direction from the wind-up reel27toward the cartridge reel13. Further, in the magnetic tape12, the rotational speed and/or the rotational torque of the feeding motor25and the winding-up motor26is adjusted so that the running speed and the tension during running are adjusted to appropriate values, but this is merely an example. For example, the rotational speed of the feeding motor25and the winding-up motor26(for example, the difference in rotational frequency between the feeding motor25and the winding-up motor26) is adjusted, whereby the running speed and the tension during running may be adjusted to appropriate values.

The feed head28and the rewind head29are disposed on the side of the front surface18of the magnetic tape12in order to access the magnetic layer16. The feed head28and the rewind head29record data on the magnetic layer16. Further, the feed head28and the rewind head29read the data recorded on the magnetic layer16.

The feed head28operates in a case where the magnetic tape12is running in the feed direction FWD. In other words, the feed head28operates in a case where the magnetic tape12is fed out from the cartridge reel13. On the other hand, the rewind head29operates in a case where the magnetic tape12is running in the rewind direction BWD. In other words, the rewind head29operates in a case where the magnetic tape12is rewound on the cartridge reel13.

The feed head28and the rewind head29have the same structure except that the feed head28and the rewind head29operate at different timings from each other. The feed head28and the rewind head29are small magnetic heads, such as a magnetic head used for a hard disk drive.

As shown inFIG.2as an example, the feed head28and the rewind head29are provided at the distal ends of the leaf spring type suspensions35and36, respectively. The proximal ends of the suspensions35and36are movably attached to the frame of the magnetic tape drive10via, for example, an arm. The suspensions35and36displace the feed head28and the rewind head29in a direction approaching the magnetic tape12, respectively. That is, the magnetic heads are pressed against the magnetic tape12by the leaf spring type suspensions35and36, respectively. Meanwhile, a floating force is generated in the magnetic head because of factors, such as the shape of the magnetic head, in the entrained flow of the magnetic tape12. Gaps are generated between the magnetic tape12and the magnetic heads because of the balance between the spring loads of the suspensions35and36on the magnetic heads and the floating forces of the magnetic heads.

Here, the spring loads generated on the magnetic heads by the suspensions35and36are each, for example, about 0.01 to 0.1 N, but this is merely an example. Although the details will be described later, the floating state of the magnetic tape12with respect to the support member30need only be maintained, and the spring load may be smaller than 0.01 N or larger than 0.1 N. For example, the spring load changes by changing the shape of the magnetic head and/or the shapes of the suspensions35and36.

The suspensions35and36may retract the feed head28and the rewind head29to a standby position away from the magnetic tape12when the feed head28and the rewind head29are not in operation.

The support member30is disposed at a position facing the feed head28and the rewind head29with the magnetic tape12interposed therebetween. Specifically, a feed support member30A is disposed at a position facing the feed head28with the magnetic tape12interposed therebetween. Further, a rewind support member30B is disposed at a position facing the rewind head29with the magnetic tape12interposed therebetween. The feed support member30A and the rewind support member30B are an example of the “first support member” according to the technique of the present disclosure. Hereinafter, for convenience of description, in a case where it is not necessary to distinguish between the feed support member30A and the rewind support member30B, the feed support member30A and the rewind support member30B are also simply referred to as “support member30”.

The support member30faces the back surface19of the magnetic tape12. Specifically, the support member30is a flat plate-shaped member. The part of the support member30facing the back surface of the magnetic tape12is a plane. The length of the support member30in the transport direction of the magnetic tape12is not particularly limited, but need only be a length capable of supporting the magnetic tape12to the extent that the magnetic head can read/write with respect to the magnetic tape12. Further, examples of a material of the support member30include an abrasive material of aluminum, but this is merely an example. The material of the support member30need only be appropriately set from the viewpoint of rigidity, durability, wear resistance, or the like, and may be, for example, a metal other than aluminum, a resin, or the like.

Meanwhile, in a case where the magnetic head is brought into contact with the magnetic tape12, a part of the magnetic tape12may be peeled off due to friction to form debris, which may be attached to the magnetic head or deposited on the magnetic tape12. In order to restrain this debris from being generated, the magnetic head has a structure, such as that used for the hard disk drive, as described above.

However, unlike the case of the hard disk drive, since the magnetic tape12is a more flexible medium than the magnetic disk provided in the hard disk drive, fluttering (that is, an increase in amplitude) may occur when the magnetic tape12is transported. As a result, the variance in the gap (that is, spacing) between the magnetic head and the magnetic tape12may become large. As a method of restraining the magnetic tape12from fluttering, for example, there is a method of supporting the magnetic head from the back surface of the magnetic tape12by using a guide roller. However, in this method, since the magnetic tape12is supported by a curved surface, even a slight change in the position of the magnetic head in the transport direction of the magnetic tape12may cause a large change in spacing. Further, in a case where a planar structure, instead of the guide roller, is directly pressed against the magnetic tape12to support the magnetic tape12, friction occurs between the magnetic tape12and the structure, debris is generated, and the running of the magnetic tape12may become unstable due to frictional resistance.

In that respect, the magnetic tape drive10according to the technique of the present disclosure comprises an air membrane forming device33. The air membrane forming device33forms an air membrane AM between the support member30and the magnetic tape12. The air membrane forming device33is an example of the “air membrane forming device” according to the technique of the present disclosure.

The air membrane forming device33comprises ultrasonic vibration sources33A and33B. The ultrasonic vibration source33A is connected to the feed support member30A. Further, the ultrasonic vibration source33B is connected to the rewind support member30B. The ultrasonic vibration sources33A and33B ultrasonically vibrate the support member30in a direction orthogonal to a longitudinal direction of the magnetic tape12and orthogonal to a width direction WD of the magnetic tape12(that is, a normal direction ND of the magnetic tape12). With this, the air membrane AM is formed between the support member30and the magnetic tape12.

Descriptions based on various theories have been made for the flotation of an object by ultrasonic vibration. That is, in a case where two planes facing each other approach each other, pressure caused by a change in the viscosity of a fluid (for example, air) existing between the planes is generated (that is, a squeeze effect). As a result, there is a theory that an air membrane (that is, a squeeze membrane) having pressure generated by the squeeze effect is formed. Further, there is also a theory that a sound field is formed between a supporting object and a floating object (for example, the support member30and the magnetic tape12) by ultrasonic vibration, and the object is floated by the difference in energy density of the sound wave of the upper and lower surfaces of the object (for example, the front surface18and the back surface19of the magnetic tape12). In either case, the vibration of the ultrasonic vibration sources33A and33B forms the air membrane AM between the support member30and the magnetic tape12. The air membrane AM is, for example, a squeeze membrane. The ultrasonic vibration sources33A and33B are an example of the “first ultrasonic vibration source” according to the technique of the present disclosure.

As a result, in a case where ultrasonic vibration is applied to the support member30from the ultrasonic vibration sources33A and33B, a floating force is generated in the magnetic tape12facing the support member30. An example of the ultrasonic vibration sources33A and33B  includes an ultrasonic vibration source using a piezoelectric element. The piezoelectric element is, for example, lead zirconate titanate (PZT; Pb(Zr,Ti)O3). For example, in a case where a voltage of about 10 to 100 V is applied to the piezoelectric element, a flotation height of about several tens to hundreds of nanometers (that is, the distance between the magnetic tape12and the support member30) can be obtained. Further, 1 N or more can be obtained as the floating force generated in the magnetic tape12. With this, the floating state of the magnetic tape12can be ensured, for example, even in a case where the magnetic head is pressed against the magnetic tape12with a force of about 1 N.

Further, the ultrasonic vibration sources33A and33B may be ultrasonic vibration sources using a laminated piezoelectric element. It is possible to increase the stroke of the ultrasonic vibration source by using the laminated piezoelectric element. With this, the flotation height is further obtained and the magnetic tape12is further separated from the support member30, so that it is realized that the magnetic tape12is transported in a state in which the influence of the surface state (that is, unevenness or surface roughness) of the magnetic tape12is reduced.

The ultrasonic vibration sources33A and33B vibrate the support member30by oscillating at a predetermined frequency. For example, the ultrasonic vibration sources33A and33B vibrate the support member30at a frequency at which the squeeze membrane is generated as the air membrane AM. Further, the ultrasonic vibration sources33A and33B vibrate the support member30at a frequency higher than the natural frequency of the magnetic tape12. The support member30having a frequency equal to or higher than the natural frequency of the magnetic tape12is vibrated, whereby the magnetic tape12cannot follow the vibration of the support member30. With this, the influence of the vibration of the support member30on the magnetic tape12is restrained.

Further, the ultrasonic vibration sources33A and33B vibrate the support member30at a frequency at which the amplitude of the magnetic tape12is within the predetermined range. The amplitude of the magnetic tape12within a predetermined range is desirably within a range equal to or smaller than the spacing between the magnetic head and the magnetic tape12, and examples thereof include 1 nanometer or less.

The ultrasonic vibration sources33A and33B are fixed to the magnetic tape drive10via fixing members34A and34B, respectively. The fixing members34A and34B are provided on the sides of the ultrasonic vibration sources33A and33B opposite to the side connected to the support member30, respectively. An example of the fixing members34A and34B includes a flat plate member made of metal. The fixing members34A and34B are fixed to the housing (not shown) of the magnetic tape drive10by, for example, a fastening member (not shown).

A first movement mechanism40is connected to the suspension35, and a second movement mechanism41is connected to the suspension36. The first movement mechanism40moves the feed head28together with the suspension35in the width direction WD of the magnetic tape12. Similarly, the second movement mechanism41moves the rewind head29together with the suspension36in the width direction WD of the magnetic tape12. The first movement mechanism40and the second movement mechanism41include, for example, an actuator, such as a voice coil motor or a piezoelectric element.

As shown inFIG.3as an example, the feed head28and the rewind head29are disposed so as to be shifted from each other in the feed direction FWD and the rewind direction BWD (that is, the longitudinal direction of the magnetic tape12) such that the feed head28and the rewind head29do not interfere with each other. A width W_H of each of the feed head28and the rewind head29is smaller than a width W_T of the magnetic tape12. Specifically, the width W_H of each of the feed head28and the rewind head29is about ½ of the width W_T of the magnetic tape12. The width W_T of the magnetic tape12is, for example, 12.65 mm, and the width W_H of each of the feed head28and the rewind head29is, for example, 6.5 mm to 7.0 mm. Incidentally, the depth and height of each of the feed head28and the rewind head29are also smaller than the width W_T of the magnetic tape12, and are, for example, about several mm. Further, a width W_G of the support member30is larger than the width W_T of the magnetic tape12.

The magnetic layer16has three servo bands SB1, SB2, and SB3, and two data bands DB1and DB2on which data is recorded. The servo bands SB1to SB3and the data bands DB1and DB2are formed along the feed direction FWD and the rewind direction BWD. The servo bands SB1to SB3are arranged at an equal interval along the width direction WD of the magnetic tape12. The data band DB1is disposed between the servo bands SB1and SB2, and the data band DB2is disposed between the servo bands SB2and SB3. That is, the servo bands SB1to SB3and the data bands DB1and DB2are alternately arranged along the width direction WD of the magnetic tape12.

A servo pattern50is recorded on the servo bands SB1to SB3. A plurality of the servo patterns50are provided at an equal interval along, for example, the feed direction FWD and the rewind direction BWD. The servo pattern50is composed of a pair of line-symmetrical linear magnetization regions51A and51B. The pair of linear magnetization regions51A and51B are non-parallel to each other and form a predetermined angle with respect to a virtual straight line along the width direction of the magnetic tape12. The predetermined angle is, for example, 10 degrees. In this case, the angle formed by the magnetization region51A and the virtual straight line along the width direction of the magnetic tape12is 5 degrees, and the angle formed by the magnetization region51B and the virtual straight line is -5 degrees. The magnetization region51A is tilted toward the side of the rewind direction BWD, and the magnetization region51B is tilted toward the side of the feed direction FWD. The servo pattern 50 is used, for example, for servo control. The servo control refers to control to move the feed head 28 and the rewind head29in the width direction WD of the magnetic tape12through the first movement mechanism 40 and the second movement mechanism41.

The feed head28records data on the data band DB1and reads the data recorded on the data band DB1. Further, the feed head28reads the servo pattern50recorded on the servo bands SB1and SB2. In other words, the feed head28takes charge of a first region divided with respect to the width direction WD of the magnetic tape12. The first region in this case is the servo bands SB1and SB2and the data band DB1.

On the other hand, the rewind head29records data on the data band DB2and reads the data recorded on the data band DB2. Further, the rewind head29reads the servo pattern50recorded on the servo bands SB2and SB3. In other words, the rewind head29takes charge of a second region divided with respect to the width direction WD of the magnetic tape12. The second region in this case is the servo bands SB2and SB3and the data band DB2.

In this way, the feed head28is in charge of recording data on the data band DB1and reading the data recorded on the data band DB1. Further, the rewind head29is in charge of recording data on the data band DB2and reading the data recorded on the data band DB2. That is, two magnetic heads are provided for two data bands DB1and DB2.

As shown inFIG.4as an example, the feed head28has a magnetic element unit MEU consisting of a plurality of magnetic elements on a surface facing the magnetic layer16. The plurality of magnetic elements act on the magnetic layer16. The feed head28causes the magnetic element to magnetically act on the magnetic layer16by bringing the magnetic element into contact with or close to the magnetic layer16. The term “close” as used herein means that the gap between the magnetic layer16and the magnetic element, which is called spacing, is maintained on, for example, the order of several nm. The magnetic element is an example of the “first magnetic element” according to the technique of the present disclosure.

The magnetic element unit MEU has two servo pattern reading elements SR1and SR2, and eight data elements DRW1, DRW2, DRW3, DRW4, DRW5, DRW6, DRW7, and DRW8. Hereinafter, in a case where it is not necessary to particularly distinguish between the servo pattern reading elements SR1and SR2and between the data elements DRW1to DRW8, the servo pattern reading elements SR1and SR2are collectively referred to as a servo pattern reading element SR, and the data elements DRW1to DRW8are collectively referred to as a data element DRW.

The servo pattern reading element SR1is provided at a position corresponding to the servo band SB1, and the servo pattern reading element SR2is provided at a position corresponding to the servo band SB2. The data elements DRW1to DRW8are provided between the servo pattern reading elements SR1and SR2. The data elements DRW1to DRW8are arranged at an equal interval along the width direction WD of the magnetic tape12. The data elements DRW1to DRW8simultaneously record data and/or read data with respect to eight data tracks DT1, DT2, DT3, DT4, DT5, DT6, DT7, and DT8. Hereinafter, in a case where it is not necessary to particularly distinguish between the data tracks DT1, DT2, DT3, DT4, DT5, DT6, DT7, and DT8, the data tracks DT1, DT2, DT3, DT4, DT5, DT6, DT7, and DT8are referred to as “data track DT”.

As shown inFIG.5as an example, the data track DT has a divided data track group DTG. The data tracks DT1to DT8shown inFIG.4correspond to the divided data track groups DTG1to DTG8shown inFIG.5, respectively. Hereinafter, in a case where it is not necessary to particularly distinguish between the divided data track groups DTG1to DTG8, the divided data track groups DTG1to DTG8are referred to as “divided data track group DTG”.

The divided data track group DTG1is a set of a plurality of divided data tracks obtained by dividing the data track DT in the width direction WD. In the example shown inFIG.5, as an example of the divided data track group DTG1, the divided data tracks DT1_1, DT1_2, DT1_3, DT1_4, ..., DT1_11, and DT1_12obtained by dividing the data track DT into12equal parts in the width direction WD are shown. The data element DRW1is in charge of magnetic processing on the divided data track group DTG1. That is, the data element DRW1is in charge of recording data on the divided data tracks DT1_1, DT1_2, DT1_3, DT1_4, ..., DT1_11, and DT1_12, and reading data from the divided data tracks DT1_1, DT1_2, DT1_3, DT1_4, ..., DT1_11, and DT1_12.

The data elements DRW2to DRW8are in charge of magnetic processing on the divided data track group DTG of the data track DT corresponding to the respective data elements DRW, as in the data element DRW1.

The data element DRW shifts to a position corresponding to one designated divided data track out of the12divided data tracks with the movement of the feed head28in the width direction WD performed by the first movement mechanism40. The data element DRW is fixed at a position corresponding to one designated data track DT by servo control using the servo pattern50.

As shown inFIG.6as an example, 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.

The data recording element DW is disposed on the upstream side of the feed direction FWD, and the data reading element DR is disposed on the downstream side of the feed direction FWD. The reason for such a disposition is that the data reading element DR immediately reads the data recorded by the data recording element DW to check errors.

Although illustration and detailed description are omitted, the rewind head29also has two servo pattern reading elements SR corresponding to the servo bands SB2and SB3and eight data elements DRW provided between two servo pattern reading elements SR. The data element DRW records data and/or reads data with respect to96data tracks DT of the data band DB2. The data element DRW includes a data recording element DW disposed on the upstream side of the rewind direction BWD and a data reading element DR disposed on the downstream side of the rewind direction BWD.

As shown inFIG.7as an example, the controller31functions as a running controller60, a first position detection unit61, a first servo controller62, a first data acquisition unit63, a first recording controller64, a first read controller65, a first data output unit66, a second position detection unit67, a second servo controller68, a second data acquisition unit69, a second recording controller70, a second read controller71, and a second data output unit72.

The running controller60controls the drive of the feeding motor25and the winding-up motor26to cause the magnetic tape12to run in the feed direction FWD or the rewind direction BWD. Further, the running controller60adjusts the rotational speed and the rotational torque of the feeding motor25and the winding-up motor26to adjust the tension during running and the running speed of the magnetic tape12to appropriate values.

A servo signal based on the servo pattern50read by the servo pattern reading element SR of the feed head28is input to the first position detection unit61. The servo signal is an intermittent pulse corresponding to the magnetization regions51A and51B. The first position detection unit61detects the position of the servo pattern reading element SR in the width direction WD of the servo band SB, that is, the position of the feed head28in the width direction WD with respect to the magnetic tape12, on the basis of the pulse interval of the servo signal. The first position detection unit61outputs the detection result of the position of the feed head28in the width direction WD to the first servo controller62.

Two types of servo signals based on the servo pattern50read by two servo pattern reading elements SR are input to the first position detection unit61. The first position detection unit61calculates the average value of the pulse intervals of two types of servo signals. Then, the position of the feed head28in the width direction WD is detected on the basis of the calculated average value.

The first servo controller62compares the detection result of the position of the feed head28from the first position detection unit61with the target position of the feed head28. In a case where the detection result is the same as the target position, the first servo controller62does nothing. In a case where the detection result deviates from the target position, the first servo controller62outputs a servo control signal for making the position of the feed head28equal to the target position, to the first movement mechanism40. The first movement mechanism40operates so as to make the position of the feed head28equal to the target position according to the servo control signal. The target position is stored in the storage22, for example, in the form of a data table (that is, a target position table) in which the values corresponding to the respective data tracks DT1to DT8are registered.

The first data acquisition unit63reads out and acquires the data to be recorded in the data band DB1by the feed head28from, for example, a host computer (not shown) connected to the magnetic tape drive10. The first data acquisition unit63outputs the data acquired from the host computer, to the first recording controller64.

The first recording controller64encodes the data input from the first data acquisition unit63into a digital signal for recording. Then, the first recording controller64causes the pulse current corresponding to the digital signal to flow through the data recording element DW of the feed head28, thereby causing the data recording element DW to record the data on the designated data track DT in the data band DB1.

The first read controller65controls the operation of the data reading element DR of the feed head28, thereby causing the data reading element DR to read the data recorded on the designated data track DT in the data band DB1. The data read by the data reading element DR is a pulse-shaped digital signal. The first read controller65outputs this pulse-shaped digital signal to the first data output unit66.

The first data output unit66decodes the pulse-shaped digital signal output from the first read controller65to obtain data. For example, the first data output unit66outputs data to the host computer.

The second position detection unit67, the second servo controller68, the second data acquisition unit69, the second recording controller70, the second read controller71, and the second data output unit72have the same functions as the first position detection unit61, the first servo controller62, the first data acquisition unit63, the first recording controller64, the first read controller65, and the first data output unit66, except that the above-described feed head28is replaced with the rewind head29and the data band DB1is replaced with the data band DB2. Therefore, detailed description thereof will be omitted.

As shown inFIG.8as an example, the controller31functions as a first vibration source controller81and a second vibration source controller82. The first vibration source controller81controls the operation of the ultrasonic vibration source33A. Further, the second vibration source controller82controls the operation of the ultrasonic vibration source33B.

The first vibration source controller81and the second vibration source controller82control the operations of the ultrasonic vibration sources33A and33B, respectively, on the basis of magnetic tape information which is information regarding the magnetic tape12. The magnetic tape information includes information regarding the transport state of the magnetic tape12and information regarding the property of the magnetic tape12.

Among the magnetic tape information, the information regarding the transport state of the magnetic tape12includes information regarding the transport speed of the magnetic tape12, information regarding the tension generated in the magnetic tape12, and information regarding the amplitude of the magnetic tape12. Further, among the magnetic tape information, the information regarding the property of the magnetic tape12includes information regarding the thickness of the magnetic tape12and information regarding the material of the magnetic tape12.

The magnetic tape drive10is provided with various sensors. Various sensors detect the transport state of the magnetic tape12. That is, a speed sensor83detects the transport speed of the magnetic tape12from the rotational speed of the feeding motor25and the winding-up motor26. The speed sensor83outputs speed information indicating the speed of the magnetic tape12to the controller31. Further, a tension sensor84detects the tension generated in the magnetic tape12from the torque generated in the feeding motor25and the winding-up motor26. The tension sensor84outputs tension information indicating the tension generated in the magnetic tape12, to the controller31. Further, a displacement sensor85detects the amplitude of the magnetic tape12. The displacement sensor85outputs amplitude information indicating the amplitude of the magnetic tape12to the controller31. The speed sensor83, the tension sensor84, and the displacement sensor85are an example of the “sensor” according to the technique of the present disclosure.

The first vibration source controller81controls the operation of the ultrasonic vibration source33A on the basis of the detection results of the speed sensor83, the tension sensor84, and the displacement sensor85. The second vibration source controller82controls the operation of the ultrasonic vibration source33B on the basis of the detection results of the speed sensor83, the tension sensor84, and the displacement sensor85. For example, the first vibration source controller81and the second vibration source controller82operate the ultrasonic vibration sources33A and33B so as to increase the frequencies in a case where the transport speed of the magnetic tape12detected by the speed sensor83increases.

Further, the first vibration source controller81and the second vibration source controller82operate the ultrasonic vibration sources33A and33B so as to increase the frequencies in a case where the tension generated in the magnetic tape12, which is detected by the tension sensor84, increases. This is because, in a case where the natural frequency of the magnetic tape12increases because of the increase in tension generated in the magnetic tape12, the ultrasonic vibration sources33A and33B are each operated at a frequency equal to or higher than the changed natural frequency. The ultrasonic vibration sources33A and33B vibrate at a frequency equal to or higher than the natural frequency, whereby the magnetic tape12cannot follow the vibration of the ultrasonic vibration sources33A and33B. With this, the influence of the vibration of the ultrasonic vibration sources33A and33B on the magnetic tape12is restrained.

Further, the first vibration source controller81and the second vibration source controller82operate the ultrasonic vibration sources33A and33B so as to increase the frequencies in a case where the amplitude of the magnetic tape12detected by the displacement sensor85increases. In this way, in a case where the amplitude of the magnetic tape12increases, the frequencies of the ultrasonic vibration sources33A and33B are increased, whereby a frequency region in which the magnetic tape12cannot follow the vibration of the ultrasonic vibration sources33A and33B can be made.

The cartridge11is provided with a cartridge memory11A. The controller31acquires information regarding the property of the magnetic tape12from the cartridge memory11A. The information regarding the property of the magnetic tape12(for example, the thickness and the material of the magnetic tape12) is stored in the cartridge memory11A. The controller31acquires information regarding the property of the magnetic tape12from the cartridge memory11A via, for example, a non-contact read/write device11B. The non-contact read/write device11B exchanges information between the controller31and the cartridge memory11A via a magnetic field under the control of the controller31.

The controller31operates the ultrasonic vibration sources33A and33B on the basis of the information regarding the property of the magnetic tape12acquired via the non-contact read/write device11B. For example, the controller31calculates a frequency equal to or higher than the natural frequency of the magnetic tape12on the basis of the thickness and the material of the magnetic tape12. The controller31operates the ultrasonic vibration sources33A and33B at a frequency equal to or higher than the natural frequency of the magnetic tape12.

Further, the information regarding the magnetic tape12may include information on the magnetic tape12, such as the date of manufacture, the manufacture unique number, the manufacturer, or the number of times of use.

Hereinafter, the action of the above configuration will be described with reference to the flowchart ofFIG.9. As shown inFIG.9as an example, first, in step ST100, the ultrasonic vibration sources33A and33B ultrasonically vibrate under the control of the first vibration source controller81and the second vibration source controller82. With this, the squeeze membrane is generated as the air membrane AM between the back surface19of the magnetic tape12and the support member30.

In the next step ST110, the feeding motor25and the winding-up motor26are operated under the control of the running controller60, and the magnetic tape12runs in the feed direction FWD or the rewind direction BWD. With this, the magnetic tape12runs in a state in which the air membrane AM is formed between the magnetic tape12and the support member30.

Then, in step ST120, the magnetic element of the feed head28or the rewind head29magnetically acts on the magnetic layer16of the magnetic tape12. Specifically, the servo pattern50is read by the servo pattern reading element SR. Further, data is recorded on the data track DT by the data recording element DW under the control of the first recording controller64or the second recording controller70. Further, data is read from the data track DT by the data reading element DR under the control of the first read controller65or the second read controller71.

The first position detection unit61or the second position detection unit67detects the position of the feed head28in the width direction WD or the position of the rewind head29in the width direction WD from the interval of the servo signals based on the servo pattern50. The first servo controller62or the second servo controller68compares the detection result of the position of the first position detection unit61or the second position detection unit67with the target position, and performs the servo control for making the position of the feed head28or the rewind head29equal to the target position.

As described above, in the magnetic tape drive10according to the first embodiment, the air membrane AM is formed between the magnetic tape12and the support member30. Accordingly, with this configuration, the friction is restrained from being generated between the magnetic tape12and the support member30, as compared with a case where the support member30that is provided on the side opposite to the magnetic head with the magnetic tape12interposed therebetween is directly pressed against the magnetic tape12.

Further, in the magnetic tape drive10according to the first embodiment, the ultrasonic vibration sources33A and33B ultrasonically vibrate the support member30in the direction orthogonal to the longitudinal direction of the magnetic tape12and orthogonal to the width direction WD of the magnetic tape12. With this, the air membrane AM is formed between the magnetic tape12and the support member30. Accordingly, with this configuration, the friction is restrained from being generated between the magnetic tape12and the support member30, as compared with a case where the air membrane AM is formed by a method other than the ultrasonic vibration.

Further, in the magnetic tape drive10according to the first embodiment, the air membrane AM is the squeeze membrane. Accordingly, with this configuration, the gap (that is, spacing) between the magnetic tape12and the support member30is restrained from varying, as compared with a case where the air membrane AM thicker than the squeeze membrane is formed between the magnetic tape12and the support member30.

Further, in the magnetic tape drive10according to the first embodiment, the ultrasonic vibration sources33A and33B vibrate at a frequency equal to or higher than the natural frequency. Accordingly, with this configuration, the gap between the magnetic head and the magnetic tape12is restrained from varying, as compared with a case where the ultrasonic vibration sources33A and33B vibrate at a frequency lower than the natural frequency of the magnetic tape12.

Further, in the magnetic tape drive10according to the first embodiment, the ultrasonic vibration sources33A and33B vibrate the support member30at a frequency at which the amplitude of the magnetic tape12is within a predetermined range. Accordingly, with this configuration, the gap between the magnetic head and the magnetic tape12is restrained from varying, as compared with a case where the ultrasonic vibration sources33A and33B vibrate at a frequency at which the amplitude of the magnetic tape12is outside the predetermined range.

Further, in the magnetic tape drive10according to the first embodiment, the first vibration source controller81and the second vibration source controller82control the ultrasonic vibration sources33A and33B, respectively, on the basis of the magnetic tape information. Accordingly, with this configuration, since the ultrasonic vibration sources33A and33B vibrate on the basis of the magnetic tape information, the gap between the magnetic head and the magnetic tape12is restrained from varying, as compared with a case where the magnetic tape information is not taken into consideration.

Further, in the magnetic tape drive10according to the first embodiment, the magnetic tape information includes the information regarding the transport state of the magnetic tape12and the information regarding the property of the magnetic tape12. Accordingly, with this configuration, the gap between the magnetic head and the magnetic tape12is restrained from varying, as compared with a case where the transport state of the magnetic tape12and the property of the magnetic tape12are not taken into consideration as the magnetic tape information.

Further, in the magnetic tape drive10according to the first embodiment, the information regarding the transport state of the magnetic tape12includes the information regarding the transport speed of the magnetic tape12, the information regarding the tension generated in the magnetic tape12, and the information regarding the amplitude of the magnetic tape12. Accordingly, with this configuration, the gap between the magnetic head and the magnetic tape12is restrained from varying, as compared with a case where the transport speed of the magnetic tape12, the tension generated in the magnetic tape12, and the amplitude of the magnetic tape12are not taken into consideration as the transport state of the magnetic tape12.

Further, in the magnetic tape drive10according to the first embodiment, the information regarding the property of the magnetic tape12includes the information regarding the thickness of the magnetic tape12and the information regarding the material of the magnetic tape12. Accordingly, with this configuration, the gap between the magnetic head and the magnetic tape12is restrained from varying, as compared with a case where the thickness of the magnetic tape12and the material of the magnetic tape12are not taken into consideration as the property of the magnetic tape12.

Further, in the magnetic tape drive10according to the first embodiment, the sensor that detects the transport state of the magnetic tape12is provided, and the operations of the ultrasonic vibration sources33A and33B are controlled on the basis of the detection result of the sensor. Accordingly, with this configuration, the gap between the magnetic head and the magnetic tape12is restrained from varying, as compared with a case where constant ultrasonic vibration is always performed regardless of the detection result of the transport state of the magnetic tape12.

Further, in the magnetic tape drive10according to the first embodiment, the magnetic head is displaced by the suspensions35and36in the direction approaching the magnetic tape12. Accordingly, with this configuration, the gap between the magnetic head and the magnetic tape12is restrained from varying, as compared with a case where the position of the magnetic head is always constant.

In the above first embodiment, an aspect in which the information regarding the transport state of the magnetic tape12includes the information regarding the transport speed of the magnetic tape12, the tension generated in the magnetic tape12, and the amplitude of the magnetic tape12has been described as an example, but the technique of the present disclosure is not limited thereto. For example, as the information regarding the transport state of the magnetic tape12, any one or two of the information regarding the transport speed of the magnetic tape12, the information regarding the tension generated in the magnetic tape12, and the information regarding the amplitude of the magnetic tape12may be used.

Further, in the above first embodiment, an aspect in which the information regarding the property of the magnetic tape12includes the information regarding the thickness of the magnetic tape12and the material of the magnetic tape12has been described as an example, but the technique of the present disclosure is not limited thereto. For example, as the information regarding the property of the magnetic tape12, either the information regarding the thickness of the magnetic tape12or the information regarding the material of the magnetic tape12may be used.

Further, in the above first embodiment, an aspect in which the operations of the ultrasonic vibration sources33A and33B are controlled on the basis of the detection results of the speed sensor83, the tension sensor84, and the displacement sensor85has been described as an example, but the technique of the present disclosure is not limited thereto. For example, the operations of the ultrasonic vibration sources33A and33B may be controlled on the basis of the detection results of any one or two of the speed sensor83, the tension sensor84, and the displacement sensor85.

Second Embodiment

In the above first embodiment, an example in which the position of the magnetic head is adjusted by the suspensions35and36has been described, but the technique of the present disclosure is not limited thereto. In the second embodiment, an aspect in which the position of the magnetic head is also adjusted by a position adjusting actuator, in addition to the suspensions35and36, will be described as an example. A magnetic tape drive10A according to the second embodiment is provided with the position adjusting actuator that adjusts the position of the magnetic head. In the second embodiment, the description of the configuration common to the first embodiment will be omitted.

As shown inFIG.10as an example, in the magnetic tape drive10A, the suspension35has a load beam55, a piezoelectric bimorph element56, and a flexure57. The load beam55is a thin flat plate made of metal having relatively high rigidity. The load beam55is attached to a base plate whose proximal end is not shown. The load beam55is connected to an actuator (for example, a voice coil motor) of the movement mechanism40via the base plate. The load beam55is formed so as to be slightly shorter in length than the flexure57. The piezoelectric bimorph element56is fixed to the distal end of the load beam55.

The piezoelectric bimorph element56consists of flat plate-shaped piezoelectric bodies56A and56B. The flat plate-shaped piezoelectric bodies56A and56B are joined to each other in a state of being laminated in the plate thickness direction. One of the piezoelectric bodies56A and56B expands and the other contracts in a case where a voltage is applied. The piezoelectric bimorph element56is an element that is bent by the expansion and contraction of the piezoelectric bodies56A and56B to move a target. The piezoelectric bodies56A and56B are, for example, lead zirconate titanate (PZT; Pb(Zr,Ti)O3). The side of the piezoelectric bimorph element56on the side of the piezoelectric body56B is attached to the flexure57. The piezoelectric bimorph element56is an example of the “position adjusting actuator” according to the technique of the present disclosure.

The flexure57is a thin flat plate made of metal having a relatively low rigidity. Therefore, the flexure57functions as a leaf spring. The feed head28is attached to the surface of the flexure57facing the surface to which the piezoelectric bimorph element56is attached.

As shown inFIG.11as an example, a length L_P and a width W_P of each of the piezoelectric bodies56A and56B are both several mm. A thickness T_P of each of the piezoelectric bodies56A and56B is several tens of µm.

As shown in the upper part ofFIG.12as an example, the piezoelectric bimorph element56bends the distal end of the flexure57by the expansion and contraction of the piezoelectric bodies56A and56B to move the feed head28, thereby adjusting the position of a magnetic element ME in the normal direction ND. That is, the piezoelectric bimorph element56adjusts the position of the feed head28along the direction orthogonal to the longitudinal direction of the magnetic tape12and orthogonal to the width direction WD of the magnetic tape12.

The piezoelectric bimorph element56operates so as to keep the spacing constant, under the control of the controller31. Specifically, in a case where the position of the magnetic tape12deviates in the direction of the feed head28from the regular position shown in the middle part ofFIG.12, the piezoelectric bimorph element56is bent in a direction away from the magnetic tape12as shown in the upper part ofFIG.12. On the other hand, in a case where the position of the magnetic tape12deviates in the direction opposite to the feed head28from the regular position shown in the middle part ofFIG.12, the piezoelectric bimorph element56is bent in a direction approaching the magnetic tape12as shown in the lower part ofFIG.12.

A bending amount ΔL in one direction of the piezoelectric bimorph element56is represented by Equation (1). In Equation (1), d is a piezoelectric strain constant and V is an applied voltage.

Here, for example, a case where the length L_P and the width W_P of each of the piezoelectric bodies56A and56B are both 1 mm and the thickness T_P of each of the piezoelectric bodies56A and56B is 50 µm is considered. In a case where the piezoelectric strain constant d of each of the piezoelectric bodies56A and56B is, for example, 200 x 10-12m/V, and a voltage of, for example, 20 V is applied to the piezoelectric bodies56A and56B, the bending amount ΔL is 1.2 µm according to Equation (1).

The feed head28has a plurality of magnetic elements ME on the surface facing the magnetic layer16. The plurality of magnetic elements ME magnetically act on the magnetic layer16. The feed head28causes the magnetic element ME to magnetically act on the magnetic layer16by bringing the magnetic element ME close to the magnetic layer16with spacing on the order of several nm therebetween.

In the above second embodiment, a case where the position of the feed head28is adjusted by the piezoelectric bimorph element56has been described, but the position of the rewind head29is also adjusted by the piezoelectric bimorph element in the same manner.

As shown inFIG.13as an example, the feed support member30A is disposed at a position facing the feed head28with the magnetic tape12interposed therebetween. The ultrasonic vibration source33A is connected to the feed support member30A. The ultrasonic vibration source33A vibrates the feed support member30A in the direction orthogonal to the longitudinal direction of the magnetic tape12and orthogonal to the width direction WD of the magnetic tape12(that is, the normal direction ND). With this, the air membrane AM is formed between the magnetic tape12and the feed support member30A.

As described above, in the magnetic tape drive10A according to the second embodiment, the position of the magnetic head is adjusted by the piezoelectric bimorph element56. Accordingly, with this configuration, the gap between the magnetic head and the magnetic tape12is restrained from varying, as compared with a case where the position of the magnetic head is always constant.

That is, the position of the magnetic head is adjusted by the piezoelectric bimorph element56, whereby the preload applied to the magnetic tape12is reduced. As a result, the gap between the magnetic head and the magnetic tape12can be further restrained from varying, as compared with a case where the position of the magnetic head is always constant.

Third Embodiment

In the above first and second embodiments, an example in which the magnetic layer16on the front surface18of the magnetic tape12is provided has been described, but the technique of the present disclosure is not limited thereto. In a magnetic tape drive10B according to the third embodiment, read/write with respect to the magnetic tape12is realized even in a case where the magnetic layer16is formed not only on the front surface18but also on the back surface19of the magnetic tape12. In the third embodiment, the description of the configuration common to the first and second embodiments will be omitted.

As shown inFIG.14as an example, in the magnetic tape drive10B, the magnetic layer16is formed on the front surface18of the magnetic tape12. In addition, the magnetic layer16is formed on the back surface19of the magnetic tape12. That is, the magnetic tape12has magnetic layers16on both surfaces.

A first feed head28A is disposed on the side of the front surface18of the magnetic tape12in order to access the magnetic layer16formed on the front surface18. Further, a second feed head28B is disposed on the side of the back surface19of the magnetic tape12in order to access the magnetic layer16formed on the back surface19. The first feed head28A and the second feed head28B operate in a case where the magnetic tape12is running in the feed direction FWD. The second feed head28B is an example of the “second magnetic head” according to the technique of the present disclosure.

A feed support member30C is disposed at a position facing the first feed head28A with the magnetic tape12interposed therebetween. Further, a feed support member30D is disposed at a position facing the second feed head28B with the magnetic tape12interposed therebetween.

The magnetic tape drive10B comprises the air membrane forming device33. The air membrane forming device33forms the air membrane AM between the feed support members30C and30D, and the magnetic tape12. As an example, the air membrane forming device33comprises ultrasonic vibration sources33C and33D.

The ultrasonic vibration source33C is connected to the feed support member30C. The ultrasonic vibration source33D is connected to the feed support member30D. Further, the ultrasonic vibration source33C is fixed to the magnetic tape drive10B via a fixing member34C. The ultrasonic vibration source33D is fixed to the magnetic tape drive10B via a fixing member34D.

The ultrasonic vibration source33C ultrasonically vibrates the feed support member30C in the direction orthogonal to the longitudinal direction of the magnetic tape12and orthogonal to the width direction WD of the magnetic tape12(that is, the normal direction ND). With this, the air membrane AM is formed between the feed support member30C and the back surface19of the magnetic tape12. Further, the ultrasonic vibration source33D ultrasonically vibrates the feed support member30D in the normal direction ND of the magnetic tape12. With this, the air membrane AM is formed between the feed support member30D and the front surface18of the magnetic tape12.

The second feed head28B and the feed support member30D are disposed at different positions from the first feed head28A and the feed support member30C in the longitudinal direction of the magnetic tape12, respectively. That is, the second feed head28B and the feed support member30D are disposed on the side of the rewind direction BWD with respect to the first feed head28A and the feed support member30C in the longitudinal direction of the magnetic tape12, respectively.

As described above, in the magnetic tape drive10B according to the third embodiment, the air membrane AM is formed between the feed support member30C and the back surface19of the magnetic tape12. Further, the air membrane AM is formed between the feed support member30D and the front surface18of the magnetic tape12. Since the magnetic tape12is supported via the air membrane AM, the influence on the magnetic layer16caused by the friction or the like during transportation is restrained even in a case where the magnetic layer16is formed on both the front surface18and the back surface19. Accordingly, with this configuration, in a case where the magnetic layer16is formed on both the front surface18and the back surface19of the magnetic tape12, a magnetic tape drive capable of reading/writing with respect to the magnetic tape12is also realized.

Modification Example

In the above third embodiment, an aspect in which the first feed head28A and the second feed head28B act on the magnetic layers16of the magnetic tape12at the same time has been described as an example, but the technique of the present disclosure is not limited thereto. As shown inFIG.15as an example, in a magnetic tape drive10C according to the modification example, a state in which the first feed head28A acts on the magnetic layer16on the front surface18of the magnetic tape12and a state in which the second feed head28B acts on the magnetic layer16on the back surface19of the magnetic tape12can be switched therebetween.

The proximal ends of the suspensions35and36are movably attached to the frame of the magnetic tape drive10via, for example, an arm. In the magnetic tape drive10C, when the second feed head28B is not in operation, the second feed head28B is moved to a standby position away from the magnetic tape12by the second movement mechanism41. In this case, as a result of the ultrasonic vibration source33D not performing ultrasonic vibration, the air membrane AM is not formed between the feed support member30D and the magnetic tape12. On the other hand, the first feed head28A is displaced in a direction approaching the front surface18of the magnetic tape12. Further, the air membrane AM is formed between the feed support member30C and the magnetic tape12. That is, a first state in which the magnetic element ME of the first feed head28A acts on the magnetic layer16on the front surface18of the magnetic tape12is realized.

On the other hand, as shown inFIG.16as an example, when the first feed head28A is not in operation, the first feed head28A is moved to a standby position away from the magnetic tape12by the first movement mechanism40. In this case, as a result of the ultrasonic vibration source33C not performing ultrasonic vibration, the air membrane AM is not formed between the feed support member30C and the magnetic tape12. On the other hand, the second feed head28B is displaced in a direction approaching the back surface19of the magnetic tape12. Further, the air membrane AM is formed between the feed support member30D and the magnetic tape12. That is, a second state in which the magnetic element ME of the second feed head28B acts on the magnetic layer16on the back surface19of the magnetic tape12is realized. The magnetic element ME of the second feed head28B is an example of the “second magnetic element” according to the technique of the present disclosure.

As described above, in the magnetic tape drive10C, it is possible to switch between the state in which the magnetic element ME of the first feed head28A acts on the magnetic layer16on the front surface18of the magnetic tape12and the state in which the magnetic element ME of the second feed head28B acts on the magnetic layer16on the back surface19of the magnetic tape12.

As described above, in the magnetic tape drive10C according to the modification example, the air membrane AM is formed between the feed support member30C and the back surface19of the magnetic tape12. Further, the air membrane AM is formed between the feed support member30D and the front surface18of the magnetic tape12. Since the magnetic tape12is supported via the air membrane AM, the influence on the magnetic layer16caused by the friction or the like during transportation is restrained even in a case where the magnetic layer16is formed on both the front surface18and the back surface19. Accordingly, with this configuration, in a case where the magnetic layer16is formed on both the front surface18and the back surface19of the magnetic tape12, a magnetic tape drive capable of reading/writing with respect to the magnetic tape12is also realized.

Further, in the magnetic tape drive10C according to the modification example, the first state and the second state can be switched therebetween. Accordingly, with this configuration, it is realized that data can be read/written only with respect to either the front surface18or the back surface19even in a case where the magnetic layer is formed on both surfaces of the magnetic tape12.

In the above third embodiment and the above modification example, an aspect in which the first feed head28A and the second feed head28B act on the front surface18and the back surface19of the magnetic tape12, respectively, has been described as an example, but the technique of the present disclosure is not limited thereto. For example, the rewind head (not shown) can have the same configuration. That is, two rewind heads that act on the respective magnetic layers16on the front surface18and the back surface19of the magnetic tape12may be provided. Further, the rewind support member (not shown) may be disposed at a position facing the rewind head with the magnetic tape12interposed therebetween, and the air membrane is formed between the rewind support member and the magnetic tape12.

In each of the above embodiments, an aspect in which the ultrasonic vibration source is provided as the air membrane forming device33has been described as an example, but the technique of the present disclosure is not limited thereto. For example, as the air membrane forming device33, air is injected between the support member30and the magnetic tape12so that the air membrane AM may be formed between the support member30and the magnetic tape12. As an example, a plurality of injection ports are provided at the part of the support member30facing the magnetic tape12. The plurality of injection ports are dispersedly provided in the part of the support member30facing the magnetic tape12. Air is injected toward the magnetic tape12via the plurality of injection ports so that the air membrane AM is formed between the support member30and the magnetic tape12.

Further, in each of the above embodiments, an aspect in which the magnetic heads are provided at the distal ends of the leaf spring type suspensions35and36has been described as an example, but the technique of the present disclosure is not limited thereto. As shown inFIG.17as an example, the read/write with respect to the magnetic tape12may be performed by a reading head90and a recording head92. The reading head90comprises a magnetic element unit90A and a holder90B. The magnetic element unit90A is held by the holder90B so as to come close to or come into contact with the running magnetic tape12. The magnetic element unit90A reads data from the magnetic tape12or reads the servo pattern50(seeFIG.3) from the magnetic tape12.

The recording head92comprises a magnetic element unit92A and a holder92B. The magnetic element unit92A is held by the holder92B so as to come close to or come into contact with the running magnetic tape12. The magnetic element unit92A records data on the magnetic tape12or reads the servo pattern50(seeFIG.3) from the magnetic tape12.

The support members30are provided at positions facing the reading head90and the recording head92with the magnetic tape12interposed therebetween, respectively. The air membrane AM is formed between the support member30and the magnetic tape12by the air membrane forming device33.

Further, the number of servo bands SB, the number of data bands DB, the number of data elements DRW, the number of data tracks DT that one data element DRW is in charge of, and the like shown in each of the above embodiments are merely an example, and the technique of the present disclosure is not particularly limited thereto.

For example, a magnetic tape12in which five servo bands SB and four data bands DB are alternately arranged along the width direction WD may be used. In this case, two feed heads and two rewind heads are provided. The width of each magnetic head is about ¼ of the width of the magnetic tape12. Further, the magnetic heads are disposed so as to be shifted from each other in the feed direction FWD and the rewind direction BWD such that the magnetic heads do not interfere with each other. The support members are disposed at positions facing the magnetic heads with the magnetic tape12interposed therebetween, respectively. The air membrane is formed between the support member and the magnetic tape12by the air membrane forming device.

Alternatively, a magnetic tape in which nine servo bands SB and eight data bands DB are alternately arranged along the width direction WD may be used. In this case, four feed heads and four rewind heads are provided. The width of each of the feed head and the rewind head is about ⅛ of the width of the magnetic tape. The support members are disposed at positions facing these magnetic heads with the magnetic tape12interposed therebetween, respectively. The air membrane is formed between the support member and the magnetic tape12by the air membrane forming device.

Alternatively, a magnetic tape in which13servo bands SB and12data bands DB are alternately arranged along the width direction WD may be used. In this case, six feed heads and six rewind heads are provided. The width of each of the feed head and the rewind head is about 1/12 of the width of the magnetic tape. The support members are disposed at positions facing the magnetic heads with the magnetic tape12interposed therebetween, respectively. The air membrane is formed between the support member and the magnetic tape12by the air membrane forming device.

Further, in each of the above embodiments, an aspect in which the feed head and the rewind head are provided as separate bodies has been described as an example, but the technique of the present disclosure is not limited thereto. For example, one magnetic head may be shared for feed/rewind without separating the feed head and the rewind head from each other. Further, the number of servo pattern reading elements SR disposed in one magnetic head may be one. Similarly, the number of data elements DRW disposed in one magnetic head may be one.

The number of data elements DRW disposed in one magnetic head may be, for example, 16, 32, or 64. Further, the number of data tracks DT that one data element DRW is in charge of for data recording and/or data reading is not limited to12that is shown as an example. The number of data tracks DT may be 1, or may be, for example, 4, 16, 32, or 64.

Further, in each of the above embodiments, an example in which the magnetic tape drive10in which the cartridge11is loaded has been shown, but the technique of the present disclosure is not limited thereto. For example, the magnetic tape12as it is in which the cartridge11is not housed may be a magnetic tape device wound around a feed reel, that is, a magnetic tape device in which the magnetic tape12is irreplaceably installed.

Further, in each of the above embodiments, an aspect in which the magnetic tape12has the magnetic layer16containing ferromagnetic powder that is shown as an example, but the technique of the present disclosure is not limited thereto. For example, the magnetic tape12may be a magnetic tape in which a ferromagnetic thin film is formed by vacuum deposition, such as sputtering.

Further, in each of the above embodiments, the computer may include, for example, a programmable logic device (PLD) which is a processor whose circuit configuration can be changed after manufacture, such as a field-programmable gate array (FPGA), and/or a dedicated electrical circuit which is a processor having a dedicated circuit configuration designed to execute specific processing, such as an application specific integrated circuit (ASIC), in place of or in addition to the CPU operating as the controller31.

The technique of the present disclosure can also appropriately combine the above-mentioned various embodiments and/or the above-mentioned various modification examples. In addition, it goes without saying that the technique of the present disclosure is not limited to the above embodiments and various configurations may be adopted without departing from the gist of the technique of the present disclosure.

The contents described and shown above are detailed descriptions of the parts related to the technique of the present disclosure, and are merely an example of the technique of the present disclosure. For example, the descriptions of the above configurations, functions, operations, and effects are the descriptions of an example of the configurations, functions, operations, and effects of the parts related to the technique of the present disclosure. Accordingly, it goes without saying that unnecessary parts may be deleted, new elements may be added, or replacements may be made with respect to the contents described and shown above, without departing from the gist of the technique of the present disclosure. Further, in order to avoid complications and facilitate understanding of the parts related to the technique of the present disclosure, descriptions of common general knowledge and the like that do not require special descriptions for enabling the implementation of the technique of the present disclosure are omitted, in the contents described and shown above.

In the present specification, “A and/or B” has the same meaning as “at least one of A or B”. That is, “A and/or B” means that only A may be used, only B may be used, or a combination of A and B may be used. In addition, in the present specification, the same concept as “A and/or B” is also applied to a case where three or more matters are expressed by “and/or”.

All documents, patent applications, and technical standards described in the present specification are incorporated in the present specification by reference to the same extent as in a case where the individual documents, patent applications, and technical standards were specifically and individually stated to be incorporated by reference.