JP5450015B2 - Magnetic tape drive device and magnetic tape drive method - Google Patents

Description

  The present invention relates to a magnetic tape driving apparatus and a magnetic tape driving method capable of driving a magnetic tape. In particular, it is useful for a magnetic tape device capable of linearly recording data on a magnetic tape having a surface smoothness Ra of 3.0 nm or less with a magnetic sensor head.

  Magnetic tape, which is a kind of magnetic recording medium, has various uses such as audio tape, video tape, and computer tape. In particular, in the field of data backup tapes for computers, with a capacity of a hard disk to be backed up, a storage capacity of several hundred GB per volume is commercialized. In the future, it will be essential to increase the capacity of backup tapes in order to cope with further increases in the capacity of hard disks.

  A magnetic tape used as a backup tape has a shorter recording wavelength as the recording capacity further increases, and the surface is being smoothed in order to suppress deterioration in recording and reproducing characteristics due to spacing. By smoothing the surface of the magnetic tape, the contact area between the magnetic head and the magnetic tape increases, and the friction between the two increases. In particular, if the static friction generated when starting the transfer of the magnetic tape from the state where the magnetic tape is in contact with the magnetic head and stopped, the magnetic tape and the magnetic head may be damaged. As a countermeasure against static friction between the magnetic head and the magnetic tape, for example, there is a technique disclosed in Patent Document 1.

  In Patent Document 1, in order to reduce the static friction between the magnetic tape and the magnetic head during magnetic recording / reproduction, the BOT part (BOT: Beginning of tape) and the EOT part (EOT: End of tape) of the magnetic tape are very small. A concave portion is formed. As a result, even when the magnetic head is located at the start or end of the magnetic tape 6, even if the transfer of the magnetic tape is started, the static friction is low, so that tape damage or the like can be suppressed.

JP 2006-127666 A

  However, in the configuration disclosed in Patent Document 1, since the concave portion can be formed only in the BOT portion and the EOT portion of the magnetic tape, the portion between the BOT portion and the EOT portion (the portion where the concave portion is not formed). If the magnetic tape is repeatedly transferred and stopped while the magnetic head is in contact with the magnetic head, the magnetic head or the magnetic tape may be damaged due to static friction between the magnetic head and the magnetic tape. is there.

  That is, when the magnetic tape is stopped, the magnetic tape sticks to the magnetic sensor head due to the static friction between the magnetic tape and the magnetic sensor head at the beginning of transfer, and damages the magnetic tape, The magnetic tape may break. Or, there is a possibility of damaging the MR element of the magnetic head. The same problem as described above also occurs when the magnetic tape stops from the transported state. Also, when switching the magnetic tape transport direction from the first direction (for example, forward direction) to the second direction (for example, reverse direction), or when switching from the second direction to the first direction, the same as above. Problems arise.

  It is an object of the present invention to provide a magnetic head and a magnetic tape when the magnetic tape is moved from the stopped state to the transported state, when the magnetic tape is transitioned from the transported state to the stopped state, or when the magnetic tape transport direction is reversed. It is an object of the present invention to provide a magnetic tape drive device that can prevent damage.

The magnetic tape drive device of the present application includes a magnetic head unit having a magnetic head capable of recording or reproducing information by sliding on the magnetic tape, and a tape capable of linear recording, and a tape transfer means for transferring the magnetic tape. A tape driving device, further comprising a head displacing means for displacing the magnetic head unit in a width direction of the magnetic tape, wherein the head displacing means moves the magnetic head unit of the magnetic tape to perform tracking servo. A tracking mode for displacing in the width direction; and a vibration mode for displacing the magnetic head unit in the width direction of the magnetic tape in a short cycle. And / or whether the tape transport means is in a state of transporting the magnetic tape. When stopping, those for vibrating the magnetic head unit in the vibration mode.

The magnetic tape driving method of the present application includes a tracking mode in which the magnetic head unit is displaced in the width direction of the magnetic tape in order to perform tracking servo, and a vibration mode in which the magnetic head unit is displaced in the width direction of the magnetic tape in a short cycle. has, when transfer start command of the magnetic tape is input, the magnetic head unit is vibrated in the width direction of the magnetic tape in the vibration mode, after the magnetic head unit starts to vibrate, the magnetic tape After the magnetic tape starts to be transferred, the vibration of the magnetic head unit is stopped.

The magnetic tape driving method of the present application includes a tracking mode in which the magnetic head unit is displaced in the width direction of the magnetic tape in order to perform tracking servo, and a vibration mode in which the magnetic head unit is displaced in the width direction of the magnetic tape in a short cycle. has, in the above state in which the magnetic tape is transported, the the transfer stop instruction of the magnetic tape is input, by vibrating the magnetic head unit in the width direction of the magnetic tape in the vibration mode, the magnetic head After the unit starts to vibrate, the transfer of the magnetic tape is stopped, and after the magnetic tape stops the transfer, the vibration of the magnetic head unit is stopped.

The magnetic tape driving method of the present application includes a tracking mode in which the magnetic head unit is displaced in the width direction of the magnetic tape in order to perform tracking servo, and a vibration mode in which the magnetic head unit is displaced in the width direction of the magnetic tape in a short cycle. the a, in a state in which the magnetic tape is transported in a first direction, the transfer direction inversion command of the magnetic tape is input, the magnetic head unit in the width direction of the magnetic tape in the vibration mode After the magnetic head unit starts vibrating, the transfer of the magnetic tape is stopped, and after the magnetic tape stops the transfer, the magnetic tape is moved in a second direction different from the first direction. The transfer is started, and after the magnetic tape starts to transfer in the second direction, the vibration of the magnetic head unit is stopped. That.

  According to the present invention, it is possible to prevent damage to the magnetic head and the magnetic tape when the magnetic tape is stopped and / or when the transfer is started.

  In the magnetic tape driving device of the present application, the head displacing unit starts when the magnetic tape transport unit stops the magnetic tape from a state of transporting in the first direction when the magnetic tape transport unit reverses the transport direction of the magnetic tape. Preferably, the magnetic head unit is vibrated until the transfer of the magnetic tape in a second direction different from the first direction is started. By adopting such a configuration, it is possible to reduce static friction between the magnetic tape and the magnetic head when the magnetic tape transport direction is reversed. Therefore, it is possible to reduce a phenomenon such as the magnetic tape sticking to the magnetic head, and it is possible to prevent the magnetic tape and / or the magnetic head from being damaged.

  In the magnetic tape driving device of the present application, the head displacing means moves the magnetic head unit in the width direction of the magnetic tape when tracking the magnetic head to an arbitrary track among the tracks formed on the magnetic tape. It is preferable to adopt a configuration that can be displaced. By adopting such a configuration, the means for vibrating the magnetic head unit and the means for moving the magnetic head in the width direction of the magnetic tape when performing tracking servo can be used together. It can be realized in a low space.

(Embodiment)
[1. Configuration of magnetic tape drive unit]
FIG. 1 is a block diagram of a magnetic tape drive apparatus according to this embodiment. FIG. 2 is a perspective view showing a specific configuration of the magnetic head 1 and the head displacement portion 7. Note that the magnetic tape drive according to this embodiment is a device capable of linear recording of data on a computer tape. Furthermore, the magnetic tape driving device according to the present embodiment is a magnetic sensor type head, and is useful for a magnetic tape device capable of linearly recording data on a magnetic tape having a surface smoothness Ra of 3.0 nm or less.

  As shown in FIG. 1, the magnetic tape drive according to the present embodiment includes a magnetic head 1, tape guides 2 and 3, a first reel 4, a head displacement unit 7, an operation unit 11, a control unit 12, and a recording / reproduction. A control unit 13, a displacement control unit 14, and motors 21 and 22 are provided. The second reel 5 and the magnetic tape 6 can be attached to and detached from the magnetic tape drive.

  The magnetic head 1 can record various kinds of information on the magnetic tape 6 and can reproduce various kinds of information recorded on the magnetic tape 6. The magnetic head 1 has a sliding surface 1b (FIG. 2) on which an MR head unit 1a (see FIG. 2) incorporating an MR element is disposed in a state where the magnetic tape 6 is loaded at a predetermined position in the apparatus. Is in contact with the magnetic tape 6. In the present embodiment, the magnetic head 1 is realized by an MR head including an MR element (magnetoresistance effect element), but the present invention is not limited to this.

  The tape guides 2 and 3 are respectively arranged on the first reel 4 side and the second reel 5 side of the magnetic head 1, and the winding angle of the magnetic tape 6 around the magnetic head 1 and the position in the width direction of the magnetic tape 6 are determined. It is regulated.

  The first reel 4 can wind a magnetic tape 6 drawn from a second reel 5 (described later). The first reel 4 is arranged in advance in the magnetic tape drive. The first reel 4 is rotationally driven in a direction indicated by an arrow E or G by a motor 21 that is driven and controlled by the control unit 12.

  The second reel 5 is disposed in a cartridge (not shown) that can be attached to and detached from the magnetic tape drive. The second reel 5 is mounted on a reel base (not shown) arranged in the apparatus when a cartridge (not shown) is mounted in the apparatus. The reel base is rotationally driven in a direction indicated by an arrow F or H by a motor 22 that is driven and controlled by the control unit 12. The first reel 4 rotates in the direction indicated by the arrow E and the second reel 5 rotates in the direction indicated by the arrow F, whereby the magnetic tape 6 is rotated in the direction indicated by the arrow A (first direction, forward direction). Can be transferred to. Further, the first reel 4 rotates in the direction indicated by the arrow G, and the second reel 5 rotates in the direction indicated by the arrow H, whereby the magnetic tape 6 is rotated in the direction indicated by the arrow B (second direction, reverse Direction).

  The magnetic tape 6 is a data recording magnetic tape. The magnetic tape 6 drawn out from the second reel 5 is brought into contact with the tape guide 3, the magnetic head 1, and the tape guide 2 in this order, and is wound around the first reel 4. In this embodiment, the magnetic tape 6 is realized by a magnetic tape compliant with the LTO (Linear Tape Open) standard, but the present invention is not limited to this.

  In this embodiment, the head displacement unit 7 is realized by a voice coil motor, but is not limited thereto. The head displacement unit 7 can displace the magnetic head 1 in the directions indicated by arrows C and D shown in FIG. 2 (the width direction of the magnetic tape 6) based on the control from the displacement control unit 14. Specifically, in the present embodiment, the head displacement unit 7 includes a tracking mode in which the magnetic head 1 is displaced in the width direction of the magnetic tape 6 in order to perform tracking servo, and the magnetic head 1 in the width direction of the magnetic tape 6. And a vibration mode that is displaced in a short cycle.

  That is, the magnetic tape driving device of the present embodiment is a device that records data on the magnetic tape 6 in a format compliant with the LTO standard. Therefore, the magnetic head 1 is parallel to the width direction of the magnetic tape 6 during data recording. In order to form a plurality of tracks and to selectively trace a plurality of tracks formed in the width direction of the magnetic tape at the time of data reproduction, it can be displaced in the width direction of the magnetic tape 6 (tracking mode). That is, by shortening the cycle of the drive current applied to the voice coil motor for tracking, the magnetic head 1 can be continuously displaced in the short direction in the width direction of the magnetic tape 6 (vibration mode). ). In the present embodiment, such a short-period displacement of the magnetic head 1 is referred to as “vibration”. Note that the tracking operation of the magnetic head 1 with respect to the magnetic tape 6 is disclosed in, for example, Japanese Patent No. 4139428, and thus detailed description thereof will be omitted.

  The operation unit 11 receives various operations such as a recording command and a stop command by the user. The operation unit 11 sends a control signal to the control unit 12 when receiving various operations by the user.

  When a control signal is sent from the operation unit 11, the control unit 12 controls the recording / playback control unit 13, the displacement control unit 14, and the motors 21 and 22 according to the content of the control signal. Specifically, the control unit 12 outputs a command signal for recording information on the magnetic tape 6 and a command signal for reading information recorded on the magnetic tape 6 to the recording / reproducing control unit 13. To do. The control unit 12 sends a command for starting or stopping vibration of the head displacement unit 7 to the displacement control unit 14. The control unit 12 sends a command for starting or stopping the operation to the motors 21 and 22.

  The recording / reproducing control unit 13 causes the magnetic head 1 to perform a recording operation or a reproducing operation in accordance with a control command from the control unit 12. Specifically, the recording / reproducing control unit 13 controls the magnetic head 1 to flow a predetermined current to generate a magnetic field in the vicinity of the sliding contact portion of the magnetic head 1 with the magnetic tape 6.

  The displacement control unit 14 sends a command to the head displacement unit 7 to displace the magnetic head 1 in the width direction of the magnetic tape 6. Specifically, when the head displacement unit 7 is realized by a voice coil motor, for example, the displacement control unit 14 applies a drive current to the voice coil motor. At this time, by controlling the drive current applied to the voice coil motor, the head displacement unit 7 can be operated at a frequency (period) corresponding to the tracking mode or the vibration mode. Note that the vibration frequency of the head displacement portion 7 in the vibration mode is preferably 10 Hz or more in order to suppress static friction between the magnetic head 1 and the magnetic tape 6.

  The present inventors use a magnetic tape that conforms to the LTO standard manufactured by Hitachi Maxell, uses a magnetic tape transfer speed of 6.2 m / sec, uses an LTO4 drive manufactured by Hewlett-Packard, and vibrates in the head displacement section 7. The experiment was performed by changing the frequency to 5 Hz, 10 Hz, and 20 Hz. The tension of the magnetic tape was changed to 0.6N, 0.7N, 0.8N, and 1.0N. The head movement amount (amplitude) given to the magnetic head was changed to 2000 μm, 50 μm, and 1 μm. The experimental results at that time are shown in (Table 1).

  In (Table 1), the value of the area surrounded by the double line is the actual head movement amount. That is, when the magnetic head is vibrated, the actual head movement amount with respect to the head movement amount (amplitude) applied to the magnetic head changes depending on the magnitude of friction between the magnetic head and the magnetic tape. . As shown in Table 1, when the vibration frequency is 10 Hz or more, the difference between the head movement amount (amplitude) given to the magnetic head and the actual head movement amount is smaller than when the frequency is 5 Hz. For example, when the head movement amount (amplitude) applied to the magnetic head is 50 μm and the tension of the magnetic tape is 0.7 N, the actual head movement amount is 36 μm (difference 14 μm) when the vibration frequency is 5 Hz. When the frequency is 10 Hz, the actual head movement amount is 44 μm (difference 6 μm). That is, it can be seen that when the vibration frequency is 5 Hz, the friction between the magnetic head and the magnetic tape is large, and the actual head movement amount is small. It can also be seen that when the vibration frequency is 10 Hz, the friction between the magnetic head and the magnetic tape is small, and the actual head movement amount is large. When the vibration frequency is 20 Hz, the difference between the head movement amount (amplitude) applied to the magnetic head and the actual head movement amount is further reduced.

  Therefore, by setting the vibration frequency to 10 Hz or more, the magnetic tape does not stick to the magnetic head when the magnetic tape is transferred and / or stopped, and the magnetic tape and / or the magnetic head may be damaged. There wasn't. On the other hand, at 5 Hz, the magnetic tape sticks to the magnetic head at the start and / or stop of the transfer of the magnetic tape, the magnetic tape is creased, or the recording surface of the magnetic tape or the sliding surface of the magnetic head is scratched. Or other damage occurred. Therefore, the vibration frequency when vibrating the magnetic head 1 is preferably 10 Hz or more.

  The head movement amount (amplitude) given to the magnetic head is about 0.1 to 165 μm because the difference from the actual head movement amount increases as the value of the movement amount increases as shown in Table 1. Is preferable (when the tape tension is 0.7 N). When the tape tension is 1.0 N, the head movement amount (amplitude) applied to the magnetic head is preferably about 0.1 to 120 μm.

[2. Operation of magnetic tape drive unit]
FIG. 3A is a flowchart showing an operation when information is recorded on the magnetic tape 6. FIG. 3B is a flowchart showing an operation when the transfer direction of the magnetic tape 6 is reversed from the direction indicated by the arrow A to the direction indicated by the arrow B. 4A shows a recording start command (a), a recording stop command (b), a transfer speed (c) of the magnetic tape 6, and an operation (d) in the head displacement unit 7 when recording information on the magnetic tape 6. FIG. . 4B shows the reversal command (a), the transport speed (b) of the magnetic tape 6 and the operation in the head displacement portion 7 when the transport direction of the magnetic tape 6 is reversed from the direction indicated by the arrow A to the direction indicated by the arrow B. (C) is shown. In FIG. 4B (c), the positive value of the transfer speed indicates the transfer speed when the magnetic tape 6 is transferred in the direction indicated by arrow A, and the negative value indicates that the magnetic tape 6 is transferred in the direction indicated by arrow B. Indicates the transfer speed when 4A (d) and 4B (c) is a period during which the head displacement unit 7 vibrates the magnetic head 1.

[2-1. (Recording operation)
First, as shown in FIG. 1, in a state where the loading of the magnetic tape 6 is completed, the magnetic tape 6 is stopped while being in contact with the sliding surface 1b (see FIG. 2) of the magnetic head 1. Since the loading operation of the magnetic tape 6 is well known, the description thereof is omitted. At this time, since the displacement control unit 14 does not give an operation command to the head displacement unit 7, the magnetic head 1 does not vibrate.

  In this state, when the user operates the operation unit 11 to input a recording start command (timing T1 in FIG. 4A), the control unit 12 outputs an operation command for the head displacement unit 7 to the displacement control unit 14. To do. The displacement control unit 14 applies a drive current to the head displacement unit 7 based on the input operation command. The head displacement unit 7 vibrates the magnetic head 1 in the directions indicated by arrows C and D (see FIG. 2) at a vibration frequency of 10 Hz based on the drive current applied from the displacement control unit 14 (step S1, FIG. 3A). Timing T2 in FIG. 4A).

  The displacement control unit 14 continues to output a drive current to the head displacement unit 7 until the transfer speed of the magnetic tape 6 is stabilized (step S3 described later).

  Next, the control unit 12 sends a command to the motor 21 to rotate the first reel 4 in the direction indicated by arrow E, and causes the motor 22 to rotate the second reel 5 in the direction indicated by arrow F. Send instructions. As a result, the motors 21 and 22 respectively start driving to rotate the first reel 4 and the second reel 5. When the first reel 4 rotates in the direction indicated by arrow E and the second reel 5 starts to rotate in the direction indicated by arrow F, the magnetic tape 6 starts to move in the direction indicated by arrow A (FIG. 3A). Step S2, timing T3 in FIG. 4A). As shown in FIG. 4A, since the magnetic head 1 is vibrated by the head displacement portion 7 at the time when the magnetic tape 6 starts to be transferred (timing T3), the gap between the magnetic head 1 and the magnetic tape 6 is increased. There is no static friction.

  Next, the control unit 12 controls the motors 21 and 22 to gradually increase the transfer speed of the magnetic tape 6 and transfer it at a constant transfer speed at a predetermined transfer speed. Specifically, the control unit 12 detects the torque current of the motors 21 and 22 while gradually accelerating the transfer speed of the magnetic tape 6 by controlling the motors 21 and 22, and the transfer speed of the magnetic tape 6 is detected. Is calculated. This transfer speed calculation process is executed at regular time intervals. The control unit 12 accumulates the calculated transfer speed data, and determines that the transfer speed of the magnetic tape 6 is stable when detecting that the change amount of the transfer speed is smaller than a predetermined amount (step of FIG. 3A). YES determination in S3, timing T4 in FIG. 4A).

  Next, when the control unit 12 determines that the transfer speed of the magnetic tape 6 is stable, the control unit 12 sends a vibration operation stop command to the displacement control unit 14. The displacement control unit 14 stops outputting the drive current to the head displacement unit 7 when a command to stop the vibration operation is sent from the control unit 12. When the application of the drive current from the displacement control unit 14 stops, the head displacement unit 7 stops the vibration (step S4 in FIG. 3A, timing T5 in FIG. 4A).

  Next, the control unit 12 outputs a command for performing tracking servo to the displacement control unit 14. The displacement control unit 14 controls the head displacement unit 7 to move the magnetic head 1 in the width direction of the magnetic tape 6 so that the data head in the magnetic head 1 follows a predetermined track based on the input command. To do. As for the detailed configuration of the magnetic head 1 and the tracking servo operation, for example, the configuration of the magnetic head and the tracking servo operation disclosed in Japanese Patent No. 4139428 can be employed (step S5 in FIG. 3A). ).

  Next, the control unit 12 outputs a command for recording data to the recording / reproducing control unit 13. The recording / reproducing control unit 13 controls the magnetic head 1 to record data on the data track of the magnetic tape 6 based on the input command. Thereby, data is recorded on the magnetic tape 6 by the magnetic head 1 (step S6 in FIG. 3A).

  Next, when recording data on the magnetic tape 6, if the user operates the operation unit 11 and inputs a reverse command, the control unit 12 controls each unit to change the transfer direction of the magnetic tape 6. . Detailed description of the inversion control will be described later (step S7 in FIG. 3A).

  Next, when data is being recorded on the magnetic tape 6 and the operation unit 11 is operated by the user and a stop command is input (YES determination in step S8 in FIG. 3A, timing T6 in FIG. 4A), the control unit 12 sends a vibration start command to the displacement control unit 14. When a vibration start command is sent from the control unit 12, the displacement control unit 14 applies a drive current to the head displacement unit 7. The head displacement unit 7 vibrates the magnetic head 1 in the direction indicated by arrows C and D (see FIG. 2) at a vibration frequency of 10 Hz based on the drive current applied from the displacement control unit 14 (step S9 in FIG. 3A). Timing T7 in FIG. 4A).

  The displacement control unit 14 continues to output a drive current to the head displacement unit 7 until the magnetic tape 6 stops (step S11 described later).

  Next, the control unit 12 outputs a stop command to the motors 21 and 22 (timing T8 in FIG. 4A). As a result, the motors 21 and 22 perform a decelerating operation that gradually decreases the rotational speeds of the first reel 4 and the second reel 5 to reduce the transfer speed of the magnetic tape 6 (step S10 in FIG. 3A). Eventually, the transfer of the magnetic tape 6 stops (step S11 in FIG. 3A, timing T9 in FIG. 4A). As shown in FIG. 4A (d), since the displacement control unit 14 continuously applies the drive current to the head displacement unit 7 after the stop command for the magnetic tape 6 is input, the magnetic head 1 performs the timing. The vibration continues from T7 until timing exceeding timing T9 (stop timing of magnetic tape 6). That is, static friction is not generated between the magnetic head 1 and the magnetic tape 6 at the timing T9 when the magnetic tape 6 stops.

  The displacement control unit 14 preferably continues to apply a drive current to the head displacement unit 7 so as to continuously vibrate the magnetic head 1 unless the power source of the magnetic tape driving device is turned off after the timing T9. Accordingly, when a recording start command is input again in the operation unit 11 after the timing T9 and the transfer of the magnetic tape 6 is started, the magnetic head 1 and the magnetic tape 6 are transferred at the transfer start timing of the magnetic tape 6 (for example, the timing T3). It is possible to prevent static friction between the two.

  In the above description, the description is based on the operation at the time of data recording on the magnetic tape 6, but the present invention can also be applied to the operation of reproducing the data recorded on the magnetic tape 6.

[2-2. (Reversing motion of magnetic tape transfer direction)
When the user operates the operation unit 11 and inputs a reversal command while the magnetic tape 6 is transported in the direction indicated by the arrow A or B (YES determination in step S7 in FIG. 3A), the control unit 12 Control is started according to the flow shown in FIG. 4 and the timing chart shown in FIG. 4B.

  First, when an inversion command is sent from the operation unit 11 (timing T11 in FIG. 4B), the control unit 12 outputs an operation command for the head displacement unit 7 to the displacement control unit 14. The displacement control unit 14 applies a drive current to the head displacement unit 7 based on the input operation command. The head displacement unit 7 vibrates the magnetic head 1 at a vibration frequency of 10 Hz in the directions indicated by arrows C and D (see FIG. 2) based on the drive current applied from the displacement control unit 14 (step S11 in FIG. 3B). Timing T12 in FIG. 4B).

  Next, the control unit 12 outputs a stop command to the motors 21 and 22 (timing T13 in FIG. 4B). As a result, the motors 21 and 22 perform a decelerating operation that gradually decreases the rotational speeds of the first reel 4 and the second reel 5 to reduce the transfer speed of the magnetic tape 6 (step S22 in FIG. 3B). Eventually, the transfer of the magnetic tape 6 stops (step S23 in FIG. 3B, timing T14 in FIG. 4B).

  Next, when the control unit 12 detects that the transfer of the magnetic tape 6 has stopped based on the torque current of the motors 21 and 22, the rotation direction of the motors 21 and 22 (magnetic tape) A command for reversing the transfer direction (6) is output. When a reversal command is sent from the control unit 12, the motors 21 and 22 rotate the first reel 4 in the direction indicated by the arrow G (see FIG. 1) and rotate the second reel 5 in the direction indicated by the arrow H. Let As a result, the magnetic tape 6 is transferred in the direction indicated by arrow B (step S24 in FIG. 3B, timing T15 in FIG. 4B).

  In addition, the control part 12 performs control which reverses the transfer direction of the magnetic tape 6 between the timings T14 to T15 of FIG. 4B.

  Further, the displacement control unit 14 applies a drive current to the head displacement unit 7 while performing control to reverse the transfer direction of the magnetic tape 6 (a series of operation periods of deceleration, stop, reverse transfer direction, and acceleration). continuing. Therefore, since the magnetic head 1 continues to vibrate while performing the control to reverse the transfer direction of the magnetic tape 6, no static friction is generated between the magnetic head 1 and the magnetic tape 6.

  Next, the control unit 12 controls the motors 21 and 22 to gradually increase the transfer speed of the magnetic tape 6 and transfer it at a constant transfer speed at a predetermined transfer speed. Specifically, the control unit 12 detects the torque current of the motors 21 and 22 while gradually accelerating the transfer speed of the magnetic tape 6 by controlling the motors 21 and 22, and the transfer speed of the magnetic tape 6 is detected. Is calculated. This transfer speed calculation process is executed at regular time intervals. The control unit 12 accumulates the calculated transfer speed data, and determines that the transfer speed of the magnetic tape 6 is stable when detecting that the change amount of the transfer speed is smaller than a predetermined amount (step in FIG. 3B). YES determination in S25, timing T16 in FIG. 4B).

  Next, when the control unit 12 determines that the transfer speed of the magnetic tape 6 is stable, the control unit 12 sends a vibration operation stop command to the displacement control unit 14. The displacement control unit 14 stops outputting the drive current to the head displacement unit 7 when a command to stop the vibration operation is sent from the control unit 12. When the application of the drive current from the displacement control unit 14 stops, the head displacement unit 7 stops the vibration (step S26 in FIG. 3B, timing T17 in FIG. 4B).

  Next, the control unit 12 outputs a command for performing tracking servo to the displacement control unit 14. The displacement control unit 14 controls the head displacement unit 7 to move the magnetic head 1 in the width direction of the magnetic tape 6 so that the data head in the magnetic head 1 follows a predetermined track based on the input command. To do. As for the detailed configuration of the magnetic head 1 and the tracking servo operation, for example, the configuration of the magnetic head and the tracking servo operation disclosed in Japanese Patent No. 4139428 can be employed (step S27 in FIG. 3B). ).

  Next, the control unit 12 outputs a command for recording data to the recording / reproducing control unit 13. The recording / reproducing control unit 13 controls the magnetic head 1 to record data on the data track of the magnetic tape 6 based on the input command. Thereby, data is recorded on the magnetic tape 6 by the magnetic head 1 (step S28 in FIG. 3B).

  The subsequent flow returns to part B in FIG. 3A.

  In this embodiment, the operation in the case where a transfer direction reversal command is input in the operation unit 11 has been described. However, when data is recorded on the magnetic tape 6 or when data is reproduced from the magnetic tape 6, the magnetic tape The present embodiment can also be applied to automatically reversing the direction of transport of the magnetic tape 6 at the beginning or end of the longitudinal direction of 6. That is, when data is recorded on the magnetic tape in a format compliant with the LTO standard, when the magnetic head reaches the end (starting end or end) in the longitudinal direction of the magnetic tape, the transfer of the magnetic tape is stopped, and the magnetic head Is moved in the width direction of the magnetic tape. Next, the transfer direction of the magnetic tape is reversed to start the transfer, and data is recorded on the magnetic tape by the magnetic head. Thus, when automatically reversing the magnetic tape transport direction at the beginning or end of the longitudinal direction of the magnetic tape, the magnetic head is vibrated from immediately before the magnetic tape is stopped until after the magnetic tape is transported in the opposite direction. Thus, it is possible to prevent the magnetic tape and / or the magnetic head from being damaged.

[3. Effects of the embodiment, etc.]
According to the present embodiment, the magnetic head 1 and the magnetic tape 6 are configured to vibrate at the timing at which static friction may occur between the magnetic head 1 and the magnetic tape 6. Can be prevented, and the possibility of damaging the magnetic head 1 or the magnetic tape 6 can be reduced. That is, when the transfer of the magnetic tape 6 is started, when the transfer from the transfer state is stopped, or when the transfer direction of the magnetic tape 6 is reversed, one of the magnetic head 1 and the magnetic tape 6 moves and the other is moved. In a stationary state (a state where static friction can occur), the head displacement unit 7 vibrates the magnetic head 1 under the control of the displacement control unit 14, so that static friction is generated between the magnetic head 1 and the magnetic tape 6. Therefore, the possibility of damaging the magnetic head 1 (such as the MR head unit 1a incorporating the MR element) or the magnetic tape 6 can be reduced.

  In addition, since the head displacement unit 7 vibrates the magnetic tape 1 under the control of the displacement control unit 14 when the transfer direction of the magnetic tape 6 is reversed, no static friction is generated between the magnetic tape 6 and the magnetic head 1. The possibility of damaging the magnetic head 1 or the magnetic tape 6 can be reduced.

  In particular, when the spacing is reduced in order to realize high-density recording on the magnetic tape, the surface property of the magnetic tape becomes smooth, so that the magnetic tape 6 can be used when the transfer of the magnetic tape 6 is started and / or stopped. There is a possibility of sticking to the magnetic head. When such sticking occurs, the magnetic tape may be cut or the magnetic tape or the magnetic head may be damaged. In the present embodiment, the static friction between the magnetic head 1 and the magnetic tape 6 is reduced by vibrating the magnetic head 1 at the start and / or stop of the transfer of the magnetic tape 6. Thereby, even if the surface property of the magnetic tape 6 becomes smooth, the magnetic tape 6 and the magnetic head 1 are prevented from sticking, and the magnetic tape 6 is cut or scratched. It is possible to prevent it from sticking.

  The head displacement unit 7 is also used as a voice coil motor for moving the magnetic head 1 in the width direction of the magnetic tape 6 in order to perform tracking servo, thereby separately vibrating the magnetic head 1. Since there is no need to provide a means, it can be realized at a low cost and the magnetic tape drive device can be miniaturized. That is, the “head displacement portion 7” in the present embodiment includes a configuration for moving the magnetic head 1 in the width direction of the magnetic tape 6 for performing tracking servo, and a configuration for vibrating the magnetic head 1. including.

  In the present embodiment, in the description of the recording operation with reference to FIGS. 3A and 4A, the operation when the magnetic tape 6 is moved in the direction indicated by the arrow A in FIG. The operation when moving in the direction indicated by arrow B can be similarly controlled. Further, the operation for reproducing the data recorded on the magnetic tape 6 can be performed in the same manner as described above.

  In the present embodiment, in the recording operation shown in FIG. 3A, after an instruction to stop the transfer of the magnetic tape 6 is input (step S8), the magnetic head 1 starts to vibrate (step S9). Although the operation control for decelerating (step S10) is performed, the magnetic tape 6 is decelerated after the transfer stop command for the magnetic tape 6 is input, and then the vibration of the magnetic head 1 is started until the magnetic tape 6 stops. It is good also as a structure controlled to do. Further, the control unit 12 detects the torque current of the motors 21 and 22 to monitor the transfer speed of the magnetic tape 6 and starts the vibration of the magnetic head 1 when the transfer speed of the magnetic tape 6 decreases to a predetermined speed. It is good also as a structure to control.

  In this embodiment, the timing of stopping the vibration of the magnetic head 1 is after the transfer speed of the magnetic tape 6 is stabilized. However, a predetermined time from the start of transfer of the magnetic tape 6 (for example, from timing T3 in FIG. 3A) A configuration may be adopted in which the vibration of the magnetic head 1 is stopped when 1 second) elapses. Such a configuration can be realized, for example, by providing the control unit 12 with a timer and measuring time from the start of transfer of the magnetic tape 6.

  In this embodiment, the timing of stopping the vibration of the magnetic head 1 is after the transfer speed of the magnetic tape 6 is stabilized. However, the transfer speed of the magnetic tape 6 reaches a predetermined speed (for example, 3 m / second). In this case, the vibration of the magnetic head 1 may be stopped. Such a configuration can be realized by calculating the transfer speed of the magnetic tape 6 based on the torque currents of the motors 21 and 22 in the control unit 12 and comparing it with a predetermined speed (for example, 3 m / sec).

  In the present embodiment, the head displacement unit 7 is configured to also serve as a voice coil motor for moving the magnetic head 1 in the width direction of the magnetic tape 6 in order to perform tracking servo. A means for vibrating the magnetic head 1 may be provided separately from the voice coil motor. In that case, as a means for vibrating the magnetic head 1, a voice coil motor, a vibration motor, an ultrasonic motor, a piezoelectric motor, or the like can be adopted.

  Japanese Laid-Open Patent Publication No. 2008-287850 is a document aimed at reducing the static friction between the magnetic tape and the magnetic head when the magnetic tape is started to be transferred, when the transfer is stopped, and when the transfer direction is reversed. . Even in the configuration disclosed in Japanese Patent Application Laid-Open No. 2008-287850, as in the present embodiment, the static friction between the magnetic tape and the magnetic head is reduced, and damage to the magnetic tape is prevented. Although there is a merit, this embodiment has a peculiar merit that the configuration for reducing the static friction between the magnetic tape and the magnetic head can be realized with a small number of parts and low cost. That is, the magnetic tape driving device according to the present embodiment originally includes means (head displacement portion 7) for moving the magnetic head in the width direction of the magnetic tape in order to perform tracking servo. Is vibrating. Therefore, it is not necessary to mount a special mechanism for vibrating the magnetic head, and the number of parts and the cost can be reduced.

  The magnetic head 1 in the present embodiment is an example of the magnetic head unit of the present invention. The motors 21 and 22 in the present embodiment are an example of the tape transport means of the present invention. The head displacement unit 7 and the displacement control unit 14 in the present embodiment are examples of the head displacement unit of the present invention. The means for moving the magnetic head 1 in the width direction of the magnetic tape 6 in order to execute the tracking servo is included in the head displacement means of the present invention.

  The magnetic tape drive of the present invention is useful for an apparatus that uses a magnetic tape as an information medium. In particular, it is useful for a magnetic tape drive capable of linearly recording data on a computer tape.

Block diagram of a magnetic tape drive device according to an embodiment The perspective view which shows the specific structure of a magnetic head and a head displacement part. Flow chart showing flow of recording operation in magnetic tape drive Flow chart showing flow of reversal operation in magnetic tape drive Timing chart of recording operation in magnetic tape drive Timing chart of reversal operation in magnetic tape drive

DESCRIPTION OF SYMBOLS 1 Magnetic head 7 Head displacement part 12 Control part 13 Recording / reproducing control part 14 Displacement control part

Claims (7)

A magnetic head unit having a magnetic head capable of recording or reproducing information by sliding on a magnetic tape;
A magnetic tape drive capable of linear recording, comprising a tape transfer means for transferring the magnetic tape,
A head displacement means for displacing the magnetic head unit in the width direction of the magnetic tape;
The head displacement means includes a tracking mode for displacing the magnetic head unit in the width direction of the magnetic tape to perform tracking servo, and a vibration mode for displacing the magnetic head unit in the width direction of the magnetic tape in a short cycle. Have
It said head displacement means, when said tape transport means to start transporting the magnetic tape from rest, and / or when the tape transport means stops the magnetic tape from the transfer state, the said magnetic head unit Magnetic tape drive that vibrates in vibration mode . The head displacement means is
When pre Kite-loop transfer means to reverse the transport direction of the magnetic tape, said from the time to stop from a state in which the magnetic tape is made to transfer to the first direction, and the magnetic tape the first direction 2. The magnetic tape drive device according to claim 1, wherein the magnetic head unit is vibrated in the vibration mode until transfer in a different second direction is started and the transfer speed of the magnetic tape is stabilized . 3. The head displacement means is
When the tape transport means reverses the transport direction of the magnetic tape, the magnetic tape is stopped from a state where the magnetic tape is transported in the first direction, and then the magnetic tape is moved to a second direction different from the first direction. The magnetic tape driving device according to claim 1, wherein the magnetic head unit is vibrated in the vibration mode until the magnetic tape unit reaches the predetermined speed until the transfer speed of the magnetic tape reaches a predetermined speed. The head displacement means is
The magnetic head unit can be displaced in the width direction of the magnetic tape in the tracking mode when tracking the magnetic head to an arbitrary track among the tracks formed on the magnetic tape. Magnetic tape drive. A tracking mode for displacing the magnetic head unit in the width direction of the magnetic tape to perform tracking servo; and a vibration mode for displacing the magnetic head unit in the width direction of the magnetic tape in a short cycle;
Wherein the transfer start command of the magnetic tape is input, by vibrating the magnetic head unit in the width direction of the magnetic tape in the vibration mode,
After the magnetic head unit starts vibrating, the transfer of the magnetic tape is started,
A magnetic tape driving method for stopping vibration of the magnetic head unit after the magnetic tape starts to be transferred. A tracking mode for displacing the magnetic head unit in the width direction of the magnetic tape to perform tracking servo; and a vibration mode for displacing the magnetic head unit in the width direction of the magnetic tape in a short cycle;
Wherein in a state where the magnetic tape is transported, the the transfer stop instruction of the magnetic tape is input, by vibrating the magnetic head unit in the width direction of the magnetic tape in the vibration mode,
After the magnetic head unit starts to vibrate, stop the transfer of the magnetic tape,
A magnetic tape driving method for stopping vibration of the magnetic head unit after the magnetic tape stops transporting. A tracking mode for displacing the magnetic head unit in the width direction of the magnetic tape to perform tracking servo; and a vibration mode for displacing the magnetic head unit in the width direction of the magnetic tape in a short cycle;
Wherein in a state where the magnetic tape is transported in a first direction, said the transport direction inversion command of the magnetic tape is input, by vibrating the magnetic head unit in the width direction of the magnetic tape in the vibration mode,
After the magnetic head unit starts to vibrate, stop the transfer of the magnetic tape,
After the magnetic tape has stopped transferring, the magnetic tape is started to transfer in a second direction different from the first direction;
A magnetic tape driving method for stopping vibration of the magnetic head unit after the magnetic tape starts to be transferred in the second direction.

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