JP2013229085A - Magnetic tape drive - Google Patents

Abstract

To provide a magnetic tape drive device capable of performing recording and reproduction by accurately bringing a magnetic head into contact with a predetermined position in the magnetic tape width direction even when the magnetic tape width fluctuates.
The magnetic head includes a magnetic head capable of recording and reproducing signals on a magnetic tape, and a magnetic tape guide for regulating a position of the magnetic tape in the width direction relative to the magnetic head. A first restricting portion 9c that contacts one edge 11a in the width direction of the magnetic tape 11; a second restricting portion 9a, 9b that contacts the other edge 11b in the width direction of the magnetic tape 11; Accordingly, the movable means for changing the position of the first restricting portion 9c in the width direction of the magnetic tape 11 and setting the distance between the first restricting portion 9c and the second restricting portions 9a, 9b to a desired value. 13.
[Selection] Figure 3

Description

  The present invention relates to a magnetic tape drive used for recording / reproducing information on / from a magnetic tape, and more particularly to a magnetic tape drive capable of reducing a positional variation in the width direction of the magnetic tape.

  Magnetic tape has various uses such as audio tape, video tape, and computer tape. In recent years, data backup tapes are increasingly used as recording media for backing up hard disk data. With an increase in the capacity of a hard disk to be backed up, an increase in capacity in the backup tape field is progressing, such as commercialization of a storage capacity of 800 GB or more per volume of magnetic tape.

  In order to increase the capacity of the magnetic tape, for example, there is a method of increasing the tape length per reel without increasing the diameter of the magnetic tape with respect to the reel by reducing the thickness of the magnetic tape. . There is also a method of increasing the recording density in the longitudinal direction of the magnetic tape by shortening the recording wavelength of data recorded on the magnetic tape. Furthermore, a technology for increasing the recording density has been developed to increase the recording density in the width direction of the magnetic tape by narrowing the recording track width of the magnetic tape.

  If the recording track width is narrowed by adopting the technology for increasing the recording density of the magnetic tape, the magnetic head will not be able to follow the recording track accurately due to fluctuations in the position of the magnetic tape in the width direction during data recording / reproduction. It becomes easy to cause. Therefore, at the time of manufacturing magnetic tape, a servo signal is recorded on the magnetic layer or the back coat layer, and the relative position of the magnetic head is detected and corrected based on the servo signal to accurately follow the recording track. Systems using the method have become mainstream.

  The servo system includes a magnetic servo system and an optical servo system. The magnetic servo system is a system in which servo signals are magnetically recorded on a magnetic layer of a magnetic tape, and servos are performed by magnetically reading the servo signals. The optical servo system is a system in which a servo signal composed of a concave array is formed on a back coat layer of a magnetic tape by laser irradiation or the like, and the concave array is optically read to perform servo. With these servo systems, when recording data on the magnetic tape or reproducing data from the magnetic tape, even if the position of the magnetic tape fluctuates in the width direction relative to the magnetic head, the magnetic head is recorded on the recording track. Can be followed.

  Specifically, the servo head reads the servo signal recorded on the magnetic tape, and the head unit (including at least the data recording head and the data reproducing head) from the repeated pattern of the read servo signal. The relative position in the width direction of the tape is detected. Then, the magnetic head is moved in the tape width direction so that the detected relative head position is the correct position, and the data recording head or the data reproducing head is made to follow the recording track. As a result, information can be accurately recorded on the magnetic tape, and information recorded on the magnetic tape can be accurately reproduced.

  In order to record and reproduce recorded data with high density by the servo method, it is important to accurately record servo signals on the magnetic tape. In particular, since the width of the magnetic tape is not constant over the entire length of the tape length, a technique for recording a servo signal at a predetermined position without depending on the fluctuation of the magnetic tape width has been proposed.

  As a technology that can accurately write a servo signal at a predetermined position on a magnetic tape, a magnetic tape drive used in a servo writer can detect fluctuations in the magnetic tape edge upstream of the recording head that writes the servo signal. A method has been proposed in which a servo signal is written by moving the recording head in the tape width direction in accordance with the detected fluctuation of the magnetic tape edge (see Patent Document 1). Also, guide rollers with spiral grooves formed on the tape contact surface are arranged on the upstream and downstream sides of the servo signal recording head, and when the magnetic tape comes into contact with the guide rollers, the magnetic tape is moved by the spiral grooves. The thing which gives the force to move to the width direction is proposed (refer patent document 2). In the technique described in Patent Document 2, since the magnetic tape moves in one direction by running while the magnetic tape is in contact with the surface of the guide roller, the position of the magnetic tape is regulated. Since the edge of the magnetic tape can be slid in a state where the edge of the magnetic tape is always pressed against the restricting member arranged as possible, the position in the width direction of the magnetic tape can be kept constant.

Japanese Patent Laid-Open No. 2003-196811 JP 2007-294005 A

  However, the magnetic tape driving device described in Patent Document 1 requires a mechanism for detecting fluctuations in the tape width direction of the magnetic tape and a mechanism for adjusting the position of the recording head, which complicates the tape driving device itself. End up. Further, it is difficult to accurately detect the position variation of the tape edge and accurately correct the position of the recording head.

  In the method described in Patent Document 2, since the position of the magnetic tape is corrected by friction between the magnetic tape and the guide roller, the condition is likely to fluctuate, and the magnetic tape may be pressed too much against the regulating member. For example, it is difficult to slide the tape edge of the magnetic tape on the regulating member in an exactly constant state.

  The present invention solves the problems in the conventional magnetic tape drive device described above, and performs recording and reproduction by accurately contacting the magnetic head at a predetermined position in the magnetic tape width direction even when the magnetic tape width fluctuates. It is an object of the present invention to provide a magnetic tape drive device that can perform the above-mentioned.

  In order to solve the above problems, a magnetic tape driving device of the present invention comprises a magnetic head capable of recording and reproducing signals on a magnetic tape, and a magnetic tape guide for regulating a position in the width direction of the magnetic tape with respect to the magnetic head, The magnetic tape guide includes a first restricting portion that contacts one edge in the width direction of the magnetic tape, a second restricting portion that contacts the other edge in the width direction of the magnetic tape, and the electric tape according to the electric signal. And a movable means for changing the position of the first restricting portion in the width direction of the magnetic tape and setting the interval between the first restricting portion and the second restricting portion to a desired value. To do.

  In the magnetic tape drive device according to the present invention, the magnetic tape guide for regulating the position of the magnetic tape in the width direction with respect to the magnetic head includes a first regulating portion and a second regulating portion that come into contact with the edge of the magnetic tape according to an electrical signal Movable means for setting the distance between the two to a desired value. Therefore, even if the width of the magnetic tape varies in the length direction of the magnetic tape, the magnetic head can be accurately brought into contact with a predetermined position in the width direction of the magnetic tape.

It is a figure which shows the whole structure of the servo writer provided with the magnetic tape drive device concerning this embodiment. It is a figure for demonstrating the positional relationship of the magnetic tape guide and magnetic head of the magnetic tape drive device concerning this embodiment. It is a block diagram which shows the structural example of the movable means in the magnetic tape guide of the magnetic tape drive device concerning this embodiment. It is a figure which shows the restriction effect of the magnetic tape position in the magnetic tape drive means concerning this embodiment by the frequency distribution of the value of PES. It is a box chart which shows the restriction effect of the magnetic tape position in the magnetic tape drive means concerning this embodiment as distribution of the value of PES. It is a figure which shows the example of a fluctuation | variation of the tape width in the length direction of a magnetic tape. It is a figure which shows the change of the value of PES in the picking position of a magnetic tape. It is a figure explaining the difference in the contact state of the magnetic tape and magnetic tape guide by the difference in the bending direction of a magnetic tape.

  The magnetic tape driving device of the present invention comprises a magnetic head capable of recording and reproducing signals on the magnetic tape, and a magnetic tape guide for regulating a position of the magnetic tape in the width direction relative to the magnetic head, the magnetic tape guide comprising: A first restricting portion that contacts one edge in the width direction of the magnetic tape; a second restricting portion that contacts the other edge in the width direction of the magnetic tape; and a position of the first restricting portion according to an electrical signal. Is moved in the width direction of the magnetic tape, and movable means for setting the distance between the first restricting portion and the second restricting portion to a desired value.

  In the magnetic tape drive of the present invention, the distance between the first restriction portion and the second restriction portion of the magnetic tape guide that restricts the position of the magnetic tape in the width direction relative to the magnetic head is changed according to the electric signal by the movable means. Therefore, even if the tape width of the magnetic tape fluctuates, the position in the width direction of the magnetic tape can be regulated by the first regulating portion and the second regulating portion. For this reason, it is possible to reduce the fluctuation of the magnetic tape in which the tape vibrates in the width direction when the magnetic tape is running, and the magnetic head can be correctly brought into contact with a predetermined position in the width direction of the magnetic tape.

  In the magnetic tape driving device of the present invention, a vibration between the first restricting portion and the second restricting portion is detected by detecting vibration of the first restricting portion caused by contact between the first restricting portion and the magnetic tape. Is preferably set. Since the contact state between the magnetic tape and the first restricting portion can be detected by the vibration generated by the contact between the magnetic tape and the first restricting portion of the magnetic tape guide, the tape width of the magnetic tape can be changed by the above configuration. The magnetic tape guide can be made to follow with high precision and can be regulated.

  The variable means is preferably a displacement means using a piezo element. By using the piezo element, the position of the first restricting portion can be changed at high speed with high accuracy by an electrical signal, and the first restricting portion can be brought into contact with the edge of the magnetic tape.

  Furthermore, it can be set as the structure which detects the vibration of a said 1st control part with the piezoelectric element of the said displacement means.

  Further, it is preferable that a servo signal is recorded on the magnetic tape by the magnetic head. By doing so, it is possible to realize recording of the servo signal on the magnetic tape with high positional accuracy required for the servo system.

  The magnetic tape driving device of the present invention will be described below with reference to the drawings.

  In addition, each figure referred below demonstrates the magnetic tape drive device of this invention simplified about the part required in order to demonstrate this invention for convenience of explanation. Therefore, the magnetic tape driving device according to the present invention can have an arbitrary configuration not shown in each of the drawings to be referred to. Moreover, the dimension of the member in each figure does not necessarily represent the dimension of an actual structural member, and the dimension ratio of each member faithfully.

(Embodiment)
FIG. 1 is a diagram showing a main configuration of a servo writer to which a magnetic tape driving device is applied as an embodiment of the present invention.

  As shown in FIG. 1, the servo writer 100 to which the magnetic tape driving device shown in the present embodiment is applied includes an AC erasing head 1, a first pulse generator 2, a servo signal recording head 3 as a magnetic head, a second The pulse generator 4, the controller 5, the tape drive 6, the first reel 7, the second reel 8, the magnetic tape guide 9, and the guide roller 10 are provided.

  The AC erasing head 1 operates based on the pulse generated by the first pulse generator 2 and AC erases the magnetic layer of the magnetic tape 11. The first pulse generator 2 generates a pulse for operating the AC erasing head 1 under the control of the controller 5. The pulses generated by the first pulse generator 2 have a predetermined duty ratio that is arbitrarily set. Note that the servo writer 100 shown in this embodiment AC erases the magnetic tape so that a magnetic field in a predetermined direction with a predetermined duty ratio remains before recording a servo signal on the magnetic tape 11. The servo signal reproduction output is improved by recording a servo signal having a directional polarity. For this reason, the servo writer 100 includes the AC erasing head 1 as shown in FIG. However, the servo writer 100 to which the magnetic tape driving device of the present invention is applied is not limited to the one shown in FIG. 1, and an AC erasing head is not essential as a servo writer.

  The servo signal recording head 3 operates based on the pulse generated by the second pulse generator 4 and magnetically records the servo signal in the servo band of the magnetic tape 11. The second pulse generator 4 generates a pulse for performing a servo signal recording operation in the servo signal recording head 3 under the control of the controller 5.

  The control unit 5 controls operations of the first pulse generation unit 2, the second pulse generation unit 4, and the tape drive unit 6. Specifically, when a servo signal is written on the magnetic tape 11, a command for AC erasing information recorded on the magnetic tape 11 is output to the first pulse generator 2, and the second pulse generator 4 A command for recording a servo signal is output to the tape drive unit 6 and a command for rotationally driving the second reel 8 is output to the tape drive unit 6.

  The tape drive unit 6 rotationally drives the second reel 8 based on a control signal from the control unit 5. By rotating the second reel 8, the magnetic tape 11 can be run in the direction indicated by the arrow 12 in FIG.

  The first reel 7 and the second reel 8 are wound on one end side and the other end side of the magnetic tape 11, respectively. When the second reel 8 is rotationally driven by the tape drive unit 6, the magnetic tape 11 fed from the first reel 7 is wound around the second reel 8.

  The magnetic tape guide 9 is disposed on both sides of the magnetic tape 11 in the running direction 12 with respect to the servo signal recording head 3, that is, on both the tape entrance side and the tape exit side. The detailed configuration of the magnetic tape guide 9 will be described later in detail with reference to FIGS.

  As an example, the guide roller 10 is rotatably disposed on the tape entry side and the exit side of each of the AC erasing head 1 and the servo signal recording head 3. The guide roller 10 regulates the position of the magnetic tape 11 so that the magnetic tape 11 travels on the sliding surface of each head. The magnetic tape drive device of this embodiment is configured to perform more precise position regulation in the tape width direction of the magnetic tape 11 at the position slidably contacting the servo signal recording head 3. In the width direction of the magnetic tape 11, a relatively rough position regulation is performed.

  A procedure for recording a servo signal on the magnetic tape 11 in the servo writer 100 according to this embodiment illustrated in FIG. 1 will be described.

  First, the magnetic tape 11 is moved in the direction indicated by the arrow 12. The magnetic layer of the magnetic tape 11 pulled out from the first reel 7 is AC erased by the AC erase head 1. Specifically, the AC erasing head 1 operates based on a pulse with a predetermined duty ratio generated by the first pulse generator 2, and magnetizes the magnetic layer of the magnetic tape 11 in a predetermined magnetization direction.

  Next, the servo signal is recorded in a predetermined servo band by the servo signal recording head 3 on the magnetic tape 11 that has been AC erased by the AC erase head 1. The servo signal recording head 3 records a servo signal by magnetizing a servo band in the magnetic tape 11 with a magnetization force in a direction opposite to the magnetization direction of the AC erasing head 1 having a larger duty ratio. The magnetic tape 11 on which the servo signal is recorded is taken up on the take-up reel 8.

  As described above, the servo writer 100 illustrated in FIG. 1 in this embodiment demagnetizes with a magnetization force opposite to the magnetization direction of the servo signal before recording the servo signal. In the case of a servo writer not provided with the head 1, the AC erasing operation by the AC head is not performed. Note that the servo signal may be recorded after the residual magnetic field is reduced to 0 by a magnetic field having a duty ratio of 50:50 using an AC head.

  FIG. 2 is a view for explaining the positional relationship between the magnetic tape 11 and the servo signal recording head 3 and the magnetic tape guide 9 which are magnetic heads in the magnetic tape driving apparatus according to the present embodiment.

  FIG. 2 shows a state viewed from a direction perpendicular to the magnetic recording surface of the magnetic tape 11. 2 shows a state in which the magnetic tape 11 does not exist as the position of the magnetic tape guide 9, and in FIG. 2, the magnetic tape 11 is assumed to be a virtual one indicating a relative position. Is displayed.

  As shown in FIG. 2, the magnetic tape guide 9 of the magnetic tape drive device of the present embodiment includes a first restricting portion 9 c arranged so as to contact one edge 11 a in the width direction of the magnetic tape 11, and the magnetic tape. 11 has two second restricting portions 9a and 9b arranged so as to be in contact with the other edge 11b in the width direction. One of the two second restricting portions 9a and 9b is disposed on the tape entry side in the traveling direction 12 of the magnetic tape 11 with respect to the servo signal recording head 3, and the first restricting portion 9c and Another second restricting portion 9 b is disposed on the tape outlet side in the running direction 12 of the magnetic tape 11 with respect to the servo signal recording head 3.

  In the magnetic tape drive device of this embodiment, the two second restricting portions 9a and 9b are both fixed at predetermined positions on the main surface of the magnetic tape drive device. Therefore, the surfaces of the second restricting portions 9 a and 9 b facing the first restricting portion 9 c restrict the position of the other edge 11 b of the magnetic tape 11. On the other hand, the position of the first restricting portion 9c is changed according to the input electric signal by a piezo actuator which is a movable means described later in detail. The surface on the side facing the restricting portions 9 a and 9 b restricts the position of one edge 11 a of the magnetic tape 11. That is, in the magnetic tape drive device of the present embodiment, the first restricting portion 9c moves in the width direction of the magnetic tape 11, the up-down direction in FIG. 2, so that the first restricting portion 9c and the second restricting portions 9a, 9b The surfaces facing each other come into contact so as to sandwich the edges 11a and 11b on both sides of the magnetic tape 11 from the outside, thereby regulating the position of the magnetic tape 11 in the width direction.

  FIG. 2 shows a state in which no voltage is applied to the piezo actuator and the distance between the first restricting portion 9c and the second restricting portions 9a and 9b is the narrowest. As described above, in the magnetic tape driving device of the present embodiment, the position of the magnetic tape is regulated so that the edges of both ends of the magnetic tape are sandwiched between the first regulating portion 9c and the second regulating portions 9a and 9b. In the state where the distance between the first restricting portion 9c and the second restricting portions 9a and 9b is the narrowest, it is preferable that the distance be smaller than the minimum value that the tape width of the magnetic tape 11 can take. For this reason, in the magnetic tape drive device of the present embodiment, the interval between the first restricting portion 9c and the second restricting portions 9a, 9b is made smaller by a margin x with respect to a predetermined design value of the magnetic tape width. It is set. In this embodiment, the margin x is set to 20 μm as an example, but the value of the margin x is a specification of movable means for changing the fluctuation range of the width of the magnetic tape and the interval between the first restricting portion and the second restricting portion. It is a value that should be optimally designed as appropriate.

  FIG. 3 is a block diagram for explaining the configuration of the movable means that varies the position of the first restricting portion in the tape guide of the tape drive device according to the present embodiment.

  FIG. 3 shows a state where the first restricting portion 9c and the second restricting portions 9a and 9b are in contact with both edges in the width direction of the magnetic tape 11. FIG. 3 shows a state where the magnetic tape 11 is viewed from the advancing direction of the tape.

  As shown in FIG. 3, the first restricting portion 9 c is fixed to a piezo element which is a movable means, more specifically, a holding portion 14 at the movable end side end of the piezo actuator 13. Therefore, when the height of the piezo actuator 13 is changed by the input electric signal, the position of the first restricting portion 9c in the height direction in FIG. 3 is changed and fixed to the surface of the magnetic tape driving device. The interval between the second restricting portions 9a and 9b is changed.

  Connected to the piezo actuator 13 is a D / A converter 15 for applying a predetermined voltage, which is an electric signal, for changing the height, that is, the length in the vertical direction of FIG. A CPU 18 that is a control unit is connected to the D / A converter 15 via a bus 17. The CPU 18 applies a predetermined voltage to the piezo actuator 13 so that the distance between the first restricting portion 9c and the second restricting portions 9a and 9b becomes a desired value by setting the height of the piezo actuator 13 to a predetermined value. Thus, the D / A converter 15 is controlled.

  Further, in the tape guide 9 of the present embodiment, the use of the piezo actuator 13 as a piezo element as the movable means for changing the position of the first restricting portion 9c makes it possible to connect the edge portion of the magnetic tape 11 and the first portion. The contact state with the first restricting portion 9c can be detected by the piezo actuator 13 as vibration of the first restricting portion 9c. The piezo actuator 13 can change its length by applying a predetermined voltage, but at the same time, when a force is applied from the outside and the length direction of the piezo actuator 13 changes, the change is reflected in the piezo actuator 13. It appears as a change in the voltage applied to 13. By utilizing this property, the AC component of the electric signal added as noise to the voltage applied to the piezo actuator 13 is detected, and how strongly the magnetic tape 11 and the first restricting portion 9c are in contact with each other based on the magnitude of the amplitude. It can be detected.

  Since the tape width of the magnetic tape 11 is not constant with respect to the tape length direction, the contact state between the edge of the magnetic tape 11 and the first restricting portion 9c changes as the magnetic tape 11 travels. For example, when the width of the magnetic tape is wider than the set interval between the first restricting portion 9c and the second restricting portions 9a, 9b, the tape edge comes into strong contact with the traveling of the magnetic tape, and the first restricting portion 9c is large. Vibrate. On the other hand, when the magnetic tape width is narrower than the set interval between the first restricting portion 9c and the second restricting portions 9a and 9b, the tape edge does not contact the first restricting portion 9c even when the magnetic tape travels. The first restricting portion 9c hardly vibrates. Therefore, by changing the distance between the first restricting portion 9c and the second restricting portions 9a and 9b so that the vibration of the first restricting portion 9c is within a predetermined range, the magnetic tape 11 is more suitable for the tape guide 9. The contact state can be maintained, and the position in the tape width direction can be correctly regulated.

  In the magnetic tape drive device of the present embodiment, for example, the distance between the first restricting portion 9c and the second restricting portions 9a and 9b of the tape guide 9 is 10 μm narrower than the design value of the tape width of the magnetic tape 11. As described above, a predetermined voltage is applied to the piezo actuator 13 from the D / A converter 15 to start the tape running. In this state, the vibration of the first restricting portion 9c due to the magnetic tape 11 running and contacting is detected by the A / D converter 16 as an electric signal that appears as a variation in the voltage applied to the piezo actuator 13, and the vibration state Is fed back to the CPU 18 via the bus 17. When the vibration of the first restricting portion 9c detected by the A / D converter 16 is larger than a predetermined range, the distance between the first restricting portion 9c and the second restricting portions 9a and 9b is the actual magnetic tape width. The CPU 18 increases the voltage applied from the D / A converter 15 to the piezo actuator 13 via the bus 17. On the other hand, when the vibration of the first restricting portion 9c detected by the A / D converter 16 is smaller than the predetermined range, the distance between the first restricting portion 9c and the second restricting portions 9a and 9b is the actual magnetic field. The CPU 18 determines that the tape width is wide, and reduces the voltage applied from the D / A converter 15 to the piezo actuator 13 via the bus 17. As described above, in the magnetic tape drive device of this embodiment, the contact state between the magnetic tape and the tape guide can be detected by the tape guide itself that regulates the position in the width direction of the magnetic tape. Without providing a tape width detecting means, it is possible to appropriately regulate the position of the magnetic tape in the width direction.

  In the above-described magnetic tape width feedback method in the magnetic tape driving device of this embodiment, the distance between the first restricting portion 9c and the second restricting portions 9a, 9b of the tape guide 9 when the magnetic tape is stared is determined as the magnetic tape. The tape width is 10 μm narrower than the design value of the tape width of 11, but this is only an example. The interval between the first restricting portion 9c and the second restricting portions 9a and 9b at the start of tape running can be set to various values. However, if the interval is too wide for the actual magnetic tape width, the magnetic tape 11, the tape width direction cannot be regulated at the start of running, and the position regulating feedback in the tape width direction is delayed because the first regulating portion 9c does not vibrate. For this reason, at the start of running of the magnetic tape 11, the distance between the first restricting portion 9c and the second restricting portions 9a and 9b is made equal to the actually assumed width of the magnetic tape 11, or slightly more than that. A narrow width is preferable. From this point of view, in this embodiment, as described above, the distance between the first restricting portion 9c and the second restricting portions 9a and 9b of the tape guide 9 when the magnetic tape is stared is set to the tape width of the magnetic tape 11. It was made to be 10 μm narrower than the value.

  Even when the tape width of the magnetic tape changes to the maximum, in order to restrict the position in the width direction of the magnetic tape by the tape guide, the first restricting portion 9c and the second restricting portion 9a shown as x in FIG. The margin value with respect to the predetermined design value of the magnetic tape width at the interval with 9b is such a value that the first restricting portion 9c can contact the edge of the magnetic tape even when the magnetic tape 11 becomes the narrowest. It is preferable to expect. Further, the movable range of the piezo actuator 13 is a range in which the distance between the first restricting portion 11c and the second restricting portions 9a and 9b can be a wider value than when the width of the magnetic tape 11 is the largest. It is preferable to set.

  As described above, in the magnetic tape drive device of this embodiment, the piezoelectric tape is used as the movable means for changing the position of the first restricting portion, so that the position in the width direction of the magnetic tape can be accurately determined in a self-contained manner. Can be regulated.

  Hereinafter, the effect of the magnetic tape drive device of this embodiment will be verified.

  In verifying the effect of the tape guide, in this specification, PES (Position Error Signal) is used as an index indicating the magnitude of fluctuation in the width direction of the magnetic tape. The PES is tracking information when a servo signal is actually recorded on the magnetic tape from the servo recording head using the tape driving device of the present embodiment, and then the servo signal is read by the servo reading head.

  In the magnetic tape drive of this embodiment, the first stripe group inclined in the first direction with respect to the longitudinal direction of the magnetic tape, and the second stripe inclined in the second direction opposite to the first direction. Two stripe groups and a third stripe group and a fourth stripe group formed subsequent to the second stripe group are repeatedly formed in the longitudinal direction of the magnetic tape. The first stripe group and the second stripe group are each composed of four stripes, and the third stripe group and the fourth stripe group are each composed of five stripes.

  The first stripe group 21 and the third stripe group are inclined at the same angle in the same direction, and the second stripe group 22 and the fourth stripe group are inclined at the same angle in the same direction. In such a servo stripe, the PES has a stripe inclination angle Y (Y = 6 ° in the present embodiment), and the nth (n = 1 to 4) stripe and the second stripe in the first servo stripe group. The distance in the center in the tape width direction from the nth (n = 1 to 4) stripe in the servo stripe group is AB (AB = 50 μm in this embodiment), the distance between the stripes at that time is ab, and the first servo When the distance between the nth (n = 1 to 4) stripe a in the stripe group 21 and the nth (n = 1 to 4) stripe c in the third servo stripe group is ac, Can be calculated.

PES = (AB− (ab / ac) × 100) / 2 tan Y (Formula 1)
The PES is calculated for each predetermined period based on the above Equation 1, and adjusts the magnetic head position in the width direction of the magnetic tape in a magnetic recording / reproducing apparatus that regulates the position of the magnetic head in the width direction of the magnetic tape by a servo method. It is used as a regulation signal for

  FIG. 4 is a frequency distribution showing how many PES values appear, and FIG. 5 is a box-and-whisker plot in which the PES values are box-plotted.

  A shown by a solid line in FIG. 4 and as a boxplot on the left side in FIG. 5 is an example of the tape drive device of this embodiment, that is, by a servo writer equipped with the tape guide of this embodiment described above. The PES in the servo signal recorded on the magnetic tape is shown.

  Also, B shown in FIG. 4 as a thin solid line and in FIG. 4 and FIG. 5, Comparative Example B shows the PES value of the servo signal recorded on the magnetic tape by restricting both sides of the magnetic tape in a state where the tape guide in the servo writer is fixed at a constant interval. Show. Here, the tape width of the 9th magnetic tape that is taken from the outside of the reel out of the magnetic tape cut into a predetermined width and a predetermined length from a state wound as a so-called pancake on the reel. As the reference tape width, the case where the servo signal is recorded by performing the position restriction of the magnetic tape in a state where the interval between the position restriction members of the magnetic tape is fixed to the width of the ninth magnetic tape is used as Comparative Example B ing.

  As shown in FIG. 4, the PES (thick solid line A) of the servo signal recorded using the magnetic tape driving device of the present embodiment is averaged and distributed around 80 to 90, and the PES is 100. The degree to exceed is small.

  On the other hand, the PES (thin solid line B) of the comparative magnetic tape in which the width direction regulating portion of the magnetic tape is fixed at the 9th magnetic tape width of the picking position has a large peak at the relatively large value of PES90. The PES values themselves are distributed over a wide range, and the degree to which the PES is 100 or more is larger than A in the embodiment.

  In the actually measured magnetic tape, the value 110 is set as the allowable range of the PES, but when the servo signal is recorded using the magnetic tape driving device of the present embodiment, almost all the numbers are in the good range. On the other hand, in the case of Comparative Example B, it can be seen that there is a defective portion with a PES exceeding 110.

  Also in the box plot shown in FIG. 5, in A in which the servo signal is recorded using the magnetic tape driving device of the present embodiment, the box portion has a smaller value than PES 90 and the PES has a large value of 100 or more. There are very few things. On the other hand, in the tape B of the comparative example, the box portion is around 90, the number of PESs 100 or more is large, and the distribution is also spread in the direction of larger values.

  As can be seen from the above measurement results, it can be seen that the servo signal can be more accurately recorded on the magnetic tape by using the magnetic tape driving method of the present embodiment.

  FIG. 6 is a diagram showing the tape width distribution in the length direction of the magnetic tape whose PES value is measured.

  As shown in FIG. 6, the magnetic tape whose PES distribution was measured had a minimum tape width of 12.6529 mm and a maximum tape width of 12.6559 mm, with a difference of 30 μm between the maximum width and the minimum width. ing. The tape width value at the first to fifth picking positions is 12.654 mm, which is relatively narrow, but the tape width increases as the picking position comes back (as the pancake core side). When the tenth position is taken, the tape width is 12.655 μm or more. In this way, the tape width increases as the take-off position becomes rearward because the take-up position is on the rear side, that is, the magnetic tape located inside the reel in a pancake state, because the magnetic tape is wound around the reel. This is probably because the tape is stretched in the width direction due to the tension applied to the tape and the pressure applied to the core.

  Next, FIG. 7 shows the distribution of the PES value according to the magnetic tape taking position in Comparative Example B when the PES value is compared and examined.

  As described above, in the tape of Comparative Example B, the width of the guide that regulates the position in the width direction of the tape is taken, and the width of the ninth tape at the position is used as a reference. For this reason, as shown in FIG. 7, the PES of the tape at the ninth picking position is the smallest value as compared with the tapes at other picking positions. When the taking position is earlier than the 9th, the PES value is larger as the take position is earlier, and the PES value is smaller as the taking position is closer to the 9th. As shown in FIG. 6, since the pressure from the outside of the pancake is smaller in the take position than the ninth, the tape width is narrower than that in the ninth take position. In the position restriction where the take-off position is fixed at the width of the ninth tape, the magnetic tape cannot be sufficiently restricted in the width direction, and it is considered that the magnetic tape has run out in the width direction. On the other hand, the PES value increases again as the picking position becomes the tenth and eleventh picking positions with the PES of the ninth magnetic tape being minimized. This is because the width of the magnetic tape on the rear side from the ninth tape is wider than the ninth magnetic tape because the pressure from the outside of the pancake is large, so the tape is within the interval of the position regulating members in the tape width direction. This can be attributed to the fact that the servo signal was recorded in a deformed state where the magnetic tape was not deformed and the magnetic tape was bent.

  In this way, when the magnetic tape is wound around a reel as pancake, the magnetic tape has an extension in the width direction, called roll-up, due to tension applied for winding or pressure from the outside of the pancake. And has a constant value in the length direction. For this reason, in the magnetic tape drive device for recording the servo signal, when the position restriction in the tape width direction using a flange having a fixed restriction width is performed, the magnetic tape width is smaller than the predetermined width. In either case or large case, the PES value becomes large. Therefore, with the method in which the interval between the position restricting portions that restrict the tape width direction is constant, no matter what value the restriction width is set, good position restriction is applied to all parts in the length direction of the magnetic tape. It is difficult to do. On the other hand, in the tape drive device of the present embodiment in which the first restricting portion can be changed in the tape width direction and the distance from the second restricting portion can be set to a predetermined value, even when the width of the magnetic tape changes, The magnetic tape can be effectively prevented from being ramped up, and the servo signal can be recorded accurately and at a more uniform position. For this reason, according to the servo writer using the magnetic tape drive device of the present embodiment, the value of PES obtained from the servo signal recorded on the magnetic tape can be made stable at a smaller level. .

  In the magnetic tape drive device of the present embodiment, as shown in FIG. 2, the tape guide 9 is provided with one first restricting portion 9c and two second restricting portions 9a and 9b. . By doing so, even when the magnetic tape is curved in its length direction, position regulation in the width direction of the magnetic tape can be performed satisfactorily. This will be described with reference to FIG.

  FIG. 8 is a schematic diagram showing that accurate position regulation can be performed by the tape guide of the present embodiment shown in FIG. 2 when the magnetic tape is curved in its length direction. FIG. 8 exaggerates the curvature of the magnetic tape in the length direction in order to easily understand the effect of the tape position restriction in the magnetic tape guide of this embodiment. The magnetic tape not only is not completely straight at its edge, but may be curved in the length direction, but the actual degree of curvature is negligible.

  In FIG. 8, FIG. 8A shows a state in which the magnetic tape 11 is curved so as to protrude upward in the drawing. FIG. 8B shows a state where the magnetic tape is curved so as to protrude downward in the figure.

  As shown in FIG. 8A, when the magnetic tape 11 is curved so as to protrude upward, the magnetic tape shown on the lower side in the figure is formed on both outer portions of the second restricting portions 9a and 9b. The other edge 11b contacts. At this time, the central portion in the left-right direction of the first restricting portion 9c is in contact with one edge 11a of the magnetic tape shown in the upper part of the drawing. In the case of the state of FIG. 8A, the interval between the first restricting portion 9c and the second restricting portions 9a, 9b becomes the maximum value W1.

  On the other hand, as shown in FIG. 8B, when the magnetic tape 11 is curved so as to protrude downward, the other side of the magnetic tape 11 is placed on both inner portions of the second restricting portions 9a and 9b. Of the edge 11b. The left and right ends of the first restricting portion 9c are in contact with one edge 11a of the magnetic tape 11. In the case of the state of FIG. 8B, the interval between the first restricting portion 9c and the second restricting portions 9a and 9b becomes the minimum value W2.

  As described above, even when the width of the magnetic tape 11 is the same, when the magnetic tape 11 is curved in the length direction, the edges at both ends of the magnetic tape 11 are well regulated by the curved direction. It can be seen that the intervals of the position restricting portions 9 are different. When the interval between the position restricting portions of the tape guide 9 is made narrower than the maximum width of the magnetic tape 11, the edge of the magnetic tape 11 is strongly pressed against the position restricting portion, and the magnetic tape 11 is pressed in the width direction. There is a problem that the flatness of the surface is lost, or the coating film on the edge portion is peeled off to become a foreign substance. In order to avoid this problem, if the interval between the position restricting portions 9 is set to the maximum width W1, when the magnetic tape 11 is curved so as to protrude downward as shown in FIG. And a first restricting portion 9c ′ indicated by a dotted line, and as a result, the position of the magnetic tape 11 cannot be restricted in the width direction.

  On the other hand, in the magnetic tape driving device of the present embodiment, the position of the first restricting portion 9c is changed by the piezo actuator 13 which is a movable means, and the magnetic tape 11 is bent downwardly in FIG. 8B. Even in the state shown in FIG. 5, the first restricting portion 9c can abut against one edge 11a of the magnetic tape 11 as shown by a solid line, so that the width direction of the magnetic tape 11 is independent of the bending direction of the magnetic tape 11. Can be regulated.

  As is apparent from the result of the above consideration, even when the magnetic tape is curved in the length direction, the width direction can be improved satisfactorily by including one first restricting portion and two second restricting portions. The position can be regulated. However, in the magnetic tape drive of the present invention, the number of the first restricting portions and the second restricting portions is not limited to that shown in FIG. For example, the number of the first restriction part and the second restriction part may be one each or two. Moreover, the case where one or both of a 1st control part and a 2nd control part is three or more may be sufficient.

  In addition, there is no particular restriction on the positional relationship between the restricting portion and the magnetic head, which is whether the first restricting portion and the second restricting portion are disposed on the tape entrance side or the tape exit side with respect to the magnetic head. In addition, it is possible to design the magnetic tape in an appropriate form as long as the magnetic head can slide on the magnetic tape in a state where the position in the width direction of the magnetic tape is sufficiently regulated with a desired accuracy.

  In the tape guide in the magnetic tape driving device of this embodiment, the first restricting portion is movable and the second restricting portion is fixed. However, at least one of the second restricting portions is movable means. May be movable. In particular, when the arrangement number of the first restricting portion and the second restricting portion is increased, the width of the magnetic tape varies, so that the width of the magnetic tape changes even in the region where the position restricting portion is arranged. Therefore, the width of the magnetic tape can be reduced without applying unnecessary external force to the magnetic tape by making all other restricting parts except the one restricting part as a reference movable with respect to the magnetic head. The position of the direction can be regulated.

  Moreover, in the said embodiment, what used the piezoelectric element as a movable means was illustrated. Although it is preferable to use a piezo element as the movable means because the position of the first restricting portion can be changed accurately and quickly, the movable means is not limited to the piezo element. For example, a member such as a VCM (Voice Coil Motor) that can instantly change the position of the first restricting portion according to an applied current can be used.

  As shown in FIG. 3, in the magnetic tape drive device of this embodiment, the piezo element is used as the movable means for changing the position of the first restricting portion, so that the tape guide itself changes the width of the magnetic tape. It was possible to form a tape guide that was detected and fed back in a self-contained manner to achieve the optimum spacing. However, the means for detecting the vibration of the first restricting portion due to contact with the magnetic tape is not limited to the piezo element, and can also be realized using a normal vibration sensor or the like. Further, as a method of following the interval of the restriction portion of the tape guide in accordance with the width of the magnetic tape, in addition to the method of feeding back in a self-contained manner using a piezoelectric element, for example, optically or mechanically A tape guide that should be determined according to the actual width value of the magnetic tape detected by the control unit by detecting a change in the tape width value in the length direction of the magnetic tape, for example, by monitoring the edge position of the magnetic tape It is also possible to adopt a method of calculating and controlling the interval between the restricting portions so that the interval between the restricting portions becomes a predetermined value.

  Moreover, in the said embodiment, the example which used the magnetic tape drive device of this invention for the servo writer was shown. This is because when the servo pattern is recorded by the servo writer, it is extremely important to sufficiently regulate the recording position of the servo signal in the width direction of the magnetic tape. Therefore, it is preferable to use the magnetic tape driving device of the present invention. However, the effect that the magnetic tape drive device of the present invention can provide good positional regulation in the width direction of the magnetic tape can be used for various magnetic recording / reproducing devices other than the servo writer. When recording / reproducing data according to the above, the relative position in the width direction between the magnetic head and the magnetic tape can be well regulated. In the magnetic tape drive of the present invention, the magnetic head capable of recording and reproducing signals on the magnetic tape is a magnetic head that only records data on the magnetic tape, a head that only reproduces data from the magnetic tape, and a magnetic tape. These heads include any head that can record data and reproduce data on a magnetic tape.

  The magnetic tape drive apparatus according to the present invention can satisfactorily regulate the position of the magnetic tape in the width direction with respect to the magnetic head even when the magnetic tape width varies. Therefore, the magnetic tape driving device according to the present invention can be used for various magnetic recording / reproducing apparatuses including a servo writer for manufacturing a servo magnetic tape.

3 Servo signal recording head (magnetic head)
DESCRIPTION OF SYMBOLS 9 Tape guide 9a, 9b 2nd control part 9c 1st control part 11 Magnetic tape 11a One edge of magnetic tape 11b The other edge of magnetic tape 13 Servo actuator (movable means)

Claims (5)

A magnetic head capable of recording and reproducing signals on magnetic tape;
A magnetic tape guide for regulating the position of the magnetic tape in the width direction with respect to the magnetic head,
The magnetic tape guide includes a first restricting portion that contacts one edge in the width direction of the magnetic tape, a second restricting portion that contacts the other edge in the width direction of the magnetic tape, and the electric tape according to the electric signal. And a movable means for changing the position of the first restricting portion in the width direction of the magnetic tape and setting the interval between the first restricting portion and the second restricting portion to a desired value. Magnetic tape drive.   2. The magnetism according to claim 1, wherein vibration of the first restricting portion caused by contact between the first restricting portion and the magnetic tape is detected to set an interval between the first restricting portion and the second restricting portion. Tape drive device.   3. The magnetic tape drive device according to claim 1, wherein the variable means is a displacement means using a piezo element.   4. The magnetic tape drive device according to claim 3, wherein vibration of the first restricting portion is detected by a piezo element of the displacement means.   The magnetic tape drive device according to claim 1, wherein a servo signal is recorded on the magnetic tape by the magnetic head.

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