JP2004145944A - Magnetic tape drive - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a magnetic tape drive by which a data track can be formed with higher density in the widthwise direction of a magnetic tape compared with a conventional magnetic tape drive. <P>SOLUTION: The head unit HU of the magnetic tape drive 10 consists of eight data signal recording heads WH1 to WH8, and a pitch Pw between the heads WH adjacent to each other is set to be equal to that between data tracks DT adjacent to each other to be formed at the magnetic tape. By this recording head group WHG, eight adjacent data tracks can simultaneously be formed at the data band of the magnetic tape during recording. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a magnetic tape drive, and more particularly to a magnetic tape drive capable of forming data tracks at a higher density in the width direction of the magnetic tape than a conventional magnetic tape drive.
[0002]
[Prior art]
In recent years, magnetic tapes used for computer data backup and the like have been increasing in storage capacity, and some have a storage capacity of 100 GB (gigabytes) or more. In such a magnetic tape, when forming data tracks along the longitudinal direction (running direction) of the magnetic tape, the width of each data track itself and the width between each data track are narrowed to increase the number of data tracks. By doing so, the density of the data track was increased.
[0003]
In order to record or reproduce data signals on such a magnetic tape, a conventional magnetic tape drive includes a head unit having a plurality of data signal recording heads and data signal reproducing heads. In this head unit, since one data signal recording head or data signal reproducing head is responsible for recording or reproducing adjacent data tracks on the magnetic tape, while reciprocating the magnetic tape with respect to the head unit a plurality of times, By moving the entire head unit by a small amount in the width direction of the magnetic tape, the data signal recording head and the data signal reproducing head are moved onto the adjacent data track to record or reproduce the data signal. Therefore, a tracking servo technique for controlling the position of the head unit in the width direction of the magnetic tape is introduced in the conventional magnetic tape drive.
[0004]
Tracking servo technology is a head in the width direction of a magnetic tape by reading a servo signal written in advance on a magnetic tape with a servo signal reading head provided in a head unit and driving an actuator in accordance with the read servo signal. This is a technique for controlling the position of the unit so that the data signal recording head and the data signal reproducing head follow the data track. As this type of tracking servo technique, for example, Patent Document 1 discloses an amplitude servo system technique in which a plurality of servo bursts as servo signals are arranged in two rows along the running direction of a magnetic tape. Patent Document 2 discloses a technique of a timing servo system in which a timing-based signal having a predetermined pattern as a servo signal is recorded on a servo track.
[0005]
[Patent Document 1]
JP-A-8-227511
[Patent Document 2]
JP-A-8-309442
[Problems to be solved by the invention]
[0006]
By the way, in a conventional magnetic tape drive, after one data track is formed by one data signal recording head, the position of the data signal recording head is formed next to the data track that has just been formed. It is moved to the position to be scheduled. Therefore, on the magnetic tape, the newly formed data track will not overlap the previously formed data track due to the control amount error when the head unit is moved in the tape width direction of the magnetic tape. In some cases, a margin (margin) having a predetermined width is provided between adjacent data tracks. In the conventional magnetic tape drive, in order to form data tracks at a higher density in the width direction of the magnetic tape, the margin width is narrowed by increasing the accuracy of the tracking servo.
[0007]
However, since there is a limit to increasing the accuracy of tracking servo, the conventional magnetic tape drive has a problem that data tracks cannot be formed at a higher density in the width direction of the magnetic tape.
[0008]
Therefore, an object of the present invention is to provide a magnetic tape drive capable of forming data tracks at a higher density in the width direction of the magnetic tape as compared with a conventional magnetic tape drive.
[0009]
[Means for Solving the Problems]
The magnetic tape drive according to claim 1 is a magnetic tape drive having a head unit including a servo head for tracking and a recording head group including a plurality of data signal recording heads. The data signal recording head is formed at a pitch corresponding to the pitch of adjacent data tracks on the magnetic tape, and the plurality of data signal recording heads simultaneously form a plurality of adjacent data tracks on the magnetic tape. It is characterized by comprising.
[0010]
According to the recording head group composed of a plurality of data signal recording heads configured as described above, a plurality of adjacent data tracks (data track group) can be simultaneously formed on the magnetic tape. That is, the data track is formed on the magnetic tape with the data track width and the data track interval as the data signal recording head is formed on the head unit. Therefore, like a conventional magnetic tape drive, it is necessary to set a margin with a width corresponding to the control amount error when the head unit is moved in the tape width direction of the magnetic tape between adjacent data tracks on the magnetic tape. Disappears. Therefore, according to the magnetic tape drive provided with this recording head group, the data tracks can be formed at a higher density in the width direction of the magnetic tape than in the conventional magnetic tape drive. Note that the pitch accuracy of adjacent data signal recording heads on the head unit depends on the processing accuracy when the head gap of the data signal recording head is formed on the head unit. The margin described above can be as close to 0 as possible.
[0011]
The magnetic tape drive according to claim 2 is the magnetic tape drive according to claim 1, wherein the head unit includes a plurality of data signal reproducing heads and is arranged in parallel with the recording head group. Each of the data signal reproducing heads is set to be narrower than the width of each of the data signal recording heads, and the positions of both ends of the reproducing head group are the tape width of the magnetic tape. In the tape width direction of the magnetic tape, it is set to be outside both ends of the recording head group so as to include a control amount error when moved in the direction, and the plurality of data signal reproducing heads, A feature is that a plurality of adjacent data tracks are simultaneously reproduced.
[0012]
According to the reproducing head group composed of a plurality of data signal reproducing heads configured as described above and arranged in parallel with the recording head group in the tape running direction of the magnetic tape, the recording head group is formed on the magnetic tape. Each data track of the data track group can be reproduced simultaneously. Further, the widths of the plurality of data signal recording heads are set to be narrower than the width of each data signal recording head, and the positions of both ends of the reproducing head group are obtained when the head unit is moved in the tape width direction of the magnetic tape. The head unit is moved in the tape width direction of the magnetic tape during reproduction because it is set to be outside the both ends of the recording head group in the tape width direction of the magnetic tape so as to include a control amount error. Even if there is an error in the control amount at that time, each data track of the data track group can be traced by any one of the data signal reproducing heads of the reproducing head group. Therefore, the data signal recorded in each data track of the data track group can be reliably reproduced. In some cases, one data track is reproduced by a plurality of data signal reproducing heads. In this case, only a data signal reproduced correctly from the data track is selected.
The reason why the adjacent data tracks are reproduced at the same time is to know which data signal reproducing head is completely tracing on the data track because the pitch of the data signal reproducing head is smaller than the pitch of the data track. In other words, it is possible to know which data signal reproducing head is on which data track only after comparing the signals detected by the plurality of data signal reproducing heads. Therefore, “reproducing at the same time” does not mean that the contents of adjacent data tracks must be read simultaneously as data, but it is sufficient if the contents of adjacent data tracks are detected by a plurality of data signal reproducing heads. This means that the data signal reproducing head that is on-track is identified by this detection, and the detection value in the required data track may be read as data.
[0013]
The magnetic tape drive according to claim 3 is the magnetic tape drive according to claim 2, wherein the number of data signal reproducing heads included in the reproducing head group is the number of data signal recording heads included in the recording head group. Nw × (Pw / Pr) where Nw is Nw, the pitch of adjacent data signal recording heads in the recording head group is Pw, and the pitch of adjacent data signal reproducing heads in the reproducing head group is Pr. More than +1 is set.
[0014]
As described above, when the number of data signal reproducing heads included in the reproducing head group is set to be larger than Nw × (Pw / Pr) +1, the positions of the data signal reproducing heads arranged at both ends of the reproducing head group are as follows. Since it is outside the data signal recording heads arranged at both ends of the recording head group, even if there is an error in the control amount when moving the head unit in the tape width direction of the magnetic tape during reproduction, the recording head group The data tracks formed by the data signal recording heads arranged at both ends of the recording head can always be traced by the data signal reproducing heads arranged at both ends of the reproducing head group or any of the data signal reproducing heads inside thereof. .
[0015]
According to a fourth aspect of the present invention, in the magnetic tape drive of the second aspect, the head width of the data signal reproducing head is equal to the pitch of adjacent data signal recording heads in the recording head group as Pw. And when
It is characterized by being set to Pw × 0.2 or more.
[0016]
As described above, when the head width of the data signal reproducing head is set to Pw × 0.2 or more, the data signal reproducing head can sufficiently obtain the required output, so that the data track is reliably reproduced. can do.
[0017]
The magnetic tape drive according to claim 5 is the magnetic tape drive according to claim 2, wherein the head width of the data signal recording head is equal to the width of the adjacent data signal reproducing head in the reproducing head group. When the distance between the adjacent data signal reproducing heads is Dr, it is set to 2 Wr + Dr or more.
[0018]
As described above, when the head width of the data signal recording head is set to 2 Wr + Dr or more, even when two adjacent data signal reproducing heads are allocated to the data track, one data signal reproducing head is always provided. Since it rides on the data track, the data track can be reliably reproduced.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of a magnetic tape drive according to the present invention will be described in detail with reference to the drawings as appropriate.
[0020]
First, a magnetic tape recorded and reproduced by the magnetic tape drive of the present invention will be described with reference to FIGS. 1 (a) and 1 (b). In the drawings to be referred to, FIG. 1A schematically shows servo tracks ST1 to ST5 formed on the surface of the magnetic tape MT and data bands DB1 to DB4 formed between the servo tracks ST. It is a partial top view of tape MT. FIG. 1B is a partially enlarged plan view of the magnetic tape MT in which a portion surrounded by a broken line in FIG.
[0021]
A magnetic tape MT shown in FIG. 1A is a magnetic tape for data backup having a width of 1/2 inch conforming to, for example, the LTO (Linear TapeOpen) standard. Five servo tracks ST1 to ST5 are written in the longitudinal direction (running direction) A of the magnetic tape MT. The servo tracks ST are formed at equal intervals in the tape width direction B of the magnetic tape MT. The servo track ST is written by a servo writer (not shown).
[0022]
Between the servo tracks ST is a band (data band) in which a data signal is recorded by the magnetic tape drive 10. Since five servo tracks ST are formed on the magnetic tape MT shown in FIG. 1A, four data bands DB1 to DB4 are formed on the magnetic tape MT. In these data bands DB1 to DB4, as shown in FIG. 1B, a large number of data tracks DT are formed at a constant pitch parallel to the servo tracks ST by the magnetic tape drive 10.
[0023]
Next, the configuration of the magnetic tape drive 10 according to the present embodiment will be described with reference to FIG. In the drawings to be referred to, FIG. 2 is a schematic configuration diagram of the magnetic tape drive 10 according to the present embodiment.
[0024]
The magnetic tape drive 10 shown in FIG. 2 is connected to a computer (not shown), and records data input from the computer as a data signal on the magnetic tape MT of the magnetic tape cartridge 20 in response to a command from the computer, or This is a device for reproducing data signals recorded on the magnetic tape MT.
[0025]
As shown in FIG. 2, the magnetic tape drive 10 mainly includes a tape reel driving device 11, an apparatus reel driving device 12, an apparatus reel 13, a head unit HU, a recording current generating circuit 14, a reproduction signal processing circuit 15, and a servo signal. A processing circuit 16, a head unit driving device 17, and a control device 18 are provided.
[0026]
Although not shown in FIG. 2, the magnetic tape drive 10 includes an insertion / removal device for inserting / removing the magnetic tape cartridge 20, a drawing device for drawing the magnetic tape MT from the magnetic tape cartridge 20, and the like. When the magnetic tape cartridge 20 is inserted into the magnetic tape drive 10, the leading end of the magnetic tape MT is pulled out by the drawing device, and the leading end is attached to the hub of the device reel 13. Hereinafter, each part of the magnetic tape drive 10 will be described.
[0027]
The tape reel drive device 11 is a device that rotationally drives the tape reel 21 of the magnetic tape cartridge 20. Further, the device reel drive device 12 is a device that drives the device reel 13 to rotate. When a data signal is recorded on the magnetic tape MT (hereinafter referred to as “during recording”) or when a data signal recorded on the magnetic tape MT is reproduced (hereinafter referred to as “during reproduction”), the tape The reel driving device 11 and the device reel driving device 12 cause the magnetic tape MT to run by rotating and driving the tape reel 21 and the device-side reel 13. Here, the case where the magnetic tape MT is pulled out from the tape reel 21 is referred to as “forward path”, and the case where the magnetic tape MT is wound around the tape reel 21 is referred to as “return path”. The magnetic tape MT travels while being guided by guides 19a and 19b.
[0028]
The head unit HU is for recording a data signal on the magnetic tape MT or reproducing a data signal recorded on the magnetic tape MT. FIG. 3A is a plan view showing the head unit HU, and FIG. 3B is a partially enlarged plan view of the head unit HU in which a portion surrounded by a broken line in FIG. 3A is enlarged. It is. FIG. 4 is a partially enlarged plan view of the head unit HU in which the vicinity of each head in FIG.
[0029]
As shown in FIG. 3A, the head unit HU has a width wider than the tape width of the magnetic tape MT, and is disposed so as to be in contact with the entire width of the magnetic tape MT. The head unit HU is moved in the tape width direction B of the magnetic tape MT by the head unit driving device 17 during recording and reproduction. As shown in FIGS. 3B and 4, the head unit HU includes a plurality of data signal recording heads WH (WH1 to WH8) for recording data signals on the magnetic tape MT on the tape sliding surface. And a plurality of data signal reproducing heads RH (RH1 to RH16) for reproducing data signals from the data track DT formed on the magnetic tape MT. The head unit HU has a plurality of servo signal reading heads SH for reading servo signals from servo tracks ST formed on the magnetic tape MT.
[0030]
As shown in FIG. 4, the plurality of data signal recording heads WH (WH1 to WH8) are arranged in a line in the tape width direction B of the magnetic tape MT as a “recording head group WHG”. In the present embodiment, the recording head group WHG includes eight data signal recording heads WH1 to WH8. According to this recording head group WHG, eight adjacent data tracks DT can be simultaneously formed in the data band DB of the magnetic tape MT during recording. Here, the eight data tracks DT formed at one time are referred to as “data track group DTG” (see FIG. 7).
[0031]
Further, the pitch Pw of the adjacent data signal recording heads WH of this recording head group WHG is set to the same size as the pitch of the adjacent data tracks DT to be formed on the magnetic tape MT. Therefore, according to the recording head group WHG configured as described above, during recording, the head unit HU is placed between the adjacent data tracks DT on the magnetic tape MT as in the conventional magnetic tape drive. Since there is no need to set a margin of width corresponding to the control amount error when moved in the width direction B, the data track DT has a higher density in the tape width direction B of the magnetic tape MT than the conventional magnetic tape drive. Can be formed. Note that the accuracy of the pitch Pw depends on the processing accuracy when processing the head gap of the data signal recording head WH on the head unit HU, so that the pitch Pw is within the processing accuracy range, The width of the data track DT, that is, the width of the data signal recording head WH can be as close as possible.
[0032]
As shown in FIG. 4, the plurality of data signal reproducing heads RH (RH1 to RH16) are arranged in a line in the tape width direction B of the magnetic tape MT as a “reproducing head group RHG”. The reproducing head group RHG is arranged in parallel with the recording head group WHG. In the present embodiment, the reproducing head group RHG includes 16 data signal reproducing heads RH1 to RH16. According to the reproducing head group RHG, the data tracks DT of the data track group DTG formed on the magnetic tape MT by the recording head group WHG can be reproduced simultaneously.
[0033]
The width of each data signal reproducing head RH of the reproducing head group RHG is set to be narrower than the width of each data signal recording head WH. The full width W2 of the reproducing head group RHG is set wider than the full width W1 of the recording head group WHG, and the positions of both ends of the reproducing head group RHG move the head unit HU in the tape width direction B of the magnetic tape MT. In order to include a control amount error at the time of the recording, the tape is set to be outside the both ends of the recording head group WHG in the tape width direction B of the magnetic tape MT. Therefore, according to the reproducing head group RHG, even when there is an error in the control amount when the head unit HU is moved in the tape width direction B of the magnetic tape MT during reproduction, any one of the reproducing head groups RHG Each data track DT of the data track group DTG can always be traced by the data signal reproducing head RH. Therefore, it is possible to reliably reproduce the data signal recorded on each data track DT of the data track group DTG. In some cases, one data track DT is reproduced by a plurality of data signal reproducing heads RH. In this case, only the data signal reproduced correctly from the data track DT is selected.
[0034]
Next, an example of reproducing the data track group DTG formed by the recording head group WHG with the reproducing head group RHG will be described with reference to FIG. FIG. 5 is an explanatory diagram showing a state in which data tracks DT1 to DT3 formed by the data signal recording heads WH1 to WH3 of the recording head group WHG are traced by the data signal reproducing heads RH2 to RH6 of the reproducing head group RHG.
[0035]
As shown in FIG. 5, the position of the data signal reproducing head RH1 arranged at one end of the reproducing head group RHG is arranged at one end of the recording head group WHG in the tape width direction B of the magnetic tape MT. Is set to be outside the data signal recording head WH1. Therefore, even when there is an error in the control amount when the head unit HU is moved in the tape width direction B of the magnetic tape MT during reproduction, the data signal recording head arranged at one end of the recording head group WHG The data track DT1 formed by WH1 must be traced by the data signal reproducing head RH1 of the reproducing head group RHG or the data signal reproducing head RH inside thereof (inside in the tape width direction B of the magnetic tape MT). Can do.
[0036]
Further, here, the head width Ww of each data signal recording head WH is 3 μm, the head width Wr of each data signal reproducing head RH is 1 μm, the interval Dw of each data signal recording head WH is 0.5 μm, and each data signal reproducing head. The RH interval Dr is set to 1 μm. Therefore, the track width of the data tracks DT1 to DT3 formed by the data signal recording heads WH1 to WH3 is 3 μm, but the head width Wr of each data signal reproducing head RH is 1 μm, and the interval Dr between the data signal reproducing heads RH. Is set to 1 μm, so even if there is an error in the control amount when the head unit HU is moved in the tape width direction B of the magnetic tape MT during reproduction, any data signal of the reproducing head group RHG Each data track DT of the data track group DTG can always be traced by the reproducing head RH.
[0037]
In other words, the data signal reproducing head RH is most likely to be separated from the data track DT when the two adjacent data signal reproducing heads RH are in positions allocated to one data track DT, that is, the data track DT. This is the case at both ends. For example, this is the case with the data signal reproducing heads RH2 and RH3 in FIG. In FIG. 5, RH2 is completely on the data track DT1, but if the distance Dr between the data signal reproducing heads RH2 and RH3 is a little wider, the data signal reproducing head RH2 is also partly disengaged from the data track DT1. In this way, even when two adjacent data signal reproducing heads RH are in the position of distribution with respect to the data track DT, in order for one data signal reproducing head RH to always get on the data track DT, two adjacent data signal reproducing heads RH are required. It is only necessary that the distance Wc between the outer ends of the two data signal reproducing heads is smaller than the width of the data track DT. That is,
Ww ≧ 2Wr + Dr (= Wc)
The data signal reproducing head RH may be formed so as to satisfy the above.
In FIG. 5, the data signal reproducing heads RH2 and RH3, the data track DT2 are traced by the data signal reproducing heads RH4 and RH5, and the data track DT3 is traced by the data signal reproducing head RH6.
[0038]
Returning to FIG. 3B and FIG. 4, the recording head group WHG and the reproducing head group RHG are arranged in the tape running direction A of the magnetic tape MT in the recording head group WHG, the reproducing head group RHG, and the recording head group. They are arranged in three rows in the order of WHG. When the traveling direction of the magnetic tape MT is the forward path, the data signal is recorded by one recording head group WHG1, and when the traveling direction is the backward path, the data signal is recorded by the other recording head group WHG2.
[0039]
Here, the reproducing head group RHG is disposed between the reproducing head group RHG1 and the recording head group WHG2 regardless of whether the magnetic tape MT travels in the forward path or in the backward path, the recording head group WHG1 or the recording head. This is because immediately after the group WHG2 records the data signal on the magnetic tape MT, the recorded data signal is reproduced for inspection. The recording head group WHG and the reproducing head group RHG can also be arranged in three rows in the order of the reproducing head group RHG, the recording head group WHG, and the reproducing head group RHG in the tape running direction A of the magnetic tape MT.
[0040]
In the present embodiment, data signals are recorded in the data bands DB1 to DB4 of the magnetic tape MT shown in FIGS. 1A and 1B, or each data track formed in the data bands DB1 to DB4. Since it is assumed that the data signal is reproduced from the DT, the recording head group WHG and the reproducing head group RHG are respectively provided at positions corresponding to the data bands DB in the head unit HU. That is, this head unit HU has eight recording head groups WHG and four reproducing head groups RHG, and 2 for each position corresponding to the data bands DB1, DB2, DB3, DB4 in the head unit HU. A group of recording heads WHG and a group of reproducing heads RHG are provided.
[0041]
The recording current generation circuit 14 is a circuit that supplies a recording current to each data signal recording head WH of the head unit HU during recording. The recording current generation circuit 14 generates a recording current based on a recording current control signal input from the control device 18 during recording, and supplies the recording current to each data signal recording head WH of the head unit HU. .
[0042]
The reproduction signal processing circuit 15 is a circuit that converts a data signal reproduced by each data signal reproduction head RH of the head unit HU into a signal (reproduction signal) that can be handled by the control device 18 during reproduction. The reproduction signal is output to the control device 18.
[0043]
The servo signal processing circuit 16 is a circuit that converts a servo signal read by the servo signal reading head SH of the head unit HU into a signal (read signal) that can be handled by the control device 18 during recording and reproduction. The read signal is output to the control device 18.
[0044]
The head unit driving device 17 is a device that moves the head unit HU in the tape width direction B of the magnetic tape MT during recording and reproduction. The head unit driving device 17 moves the head unit HU in the tape width direction B of the magnetic tape MT based on the head unit control signal input from the control device 18 at the time of recording and reproduction, and the recording head in the data band DB. The positions of the group WHG and the reproducing head group RHG (position in the tape width direction B of the magnetic tape MT) are adjusted.
[0045]
The control device 18 is a device for controlling the operation of each part of the magnetic tape drive 10. During recording, the control device 18 generates a recording current control signal based on data input from a computer (not shown) and outputs the recording current control signal to the recording current generation circuit 14. Further, at the time of reproduction, the control device 18 converts the reproduction signal input from the reproduction signal processing circuit 15 into a data format to be output to the computer, and outputs the converted data to the computer.
[0046]
Further, the control device 18 records or reproduces the recording head group WHG or the reproducing head group RHG of the head unit HU in the tape width direction B of the magnetic tape MT based on the read signal input from the servo signal processing circuit 16 during recording and reproduction. The misalignment is detected. Then, a head unit control signal is generated in consideration of the positional movement amount for correcting the positional deviation of the recording head group WHG or the reproducing head group RHG with respect to the tape width direction B of the magnetic tape MT, and is output to the head unit driving device 17. ing.
[0047]
Next, the recording and reproduction operations of the head unit HU included in the magnetic tape drive 10 configured as described above will be described with reference to FIGS. In the drawings to be referred to, FIG. 6 is a partial plan view of the magnetic tape MT and the head unit HU for explaining the operation of the head unit HU at the time of recording or reproduction, and (a) shows the recording / recording of the data track group DTG1. (B) shows the state after recording or reproducing the data track group DTG1, and (c) shows the time when recording / reproducing the data track group DTG2. FIG. 7 is a partial plan view of the magnetic tape MT showing the data track groups DTG1 to DTG12 formed in the data band DB1 by the head unit HU.
[0048]
First, recording will be described. At the time of recording, first, a data track group DTG1 is formed in the data band DB1 by the recording head group WHG1 of the head unit HU while the magnetic tape MT is run in the forward direction A1 by the tape reel driving device 11 and the device reel driving device 12. (See FIG. 6 (a)). At this time, the recording head group WHG1 forms eight data tracks DT at the same time.
[0049]
Next, after the recording head group WHG1 forms the data track group DTG1, the head unit HU is moved in the tape width direction B1 of the magnetic tape MT by the head unit driving device 17, and the position of the recording head group WHG2 in the data band DB1 ( The position of the magnetic tape MT in the tape width direction B) is moved to the position DTG2 ′ where the next data track group DTG2 is to be formed next to the data track group DTG1 that has just been formed (see FIG. 6B).
[0050]
When the head unit HU is moved, the amount of movement of the head unit HU is such that a “guard band GB” having a predetermined width W3 is formed between the data track group DTG1 and the data track group DTG2. The amount is set (see FIG. 7). The width W3 of the guard band GB is set to a width commensurate with the control amount error when the head unit HU is moved in the tape width direction B of the magnetic tape MT. That is, the guard band GB becomes a margin for the control amount error in the tape width direction B of the head unit HU.
[0051]
Then, the data track group DTG2 is formed in the data band DB1 by the recording head group WHG2 while the tape reel driving device 11 and the device reel driving device 12 run the magnetic tape MT in the backward direction A2 (see FIG. 6C). ).
[0052]
By repeating the above operation, a large number of data tracks DT can be formed in the data band DB1. For example, when 96 data tracks DT are formed in the data band DB1, the head unit HU is moved to the tape width of the magnetic tape MT during each run while the magnetic tape MT is run six times in the forward direction A1 and the return direction A2. By moving in the direction B, the recording head group WHG1 and the recording head group WHG2 can form 12 data track groups DTG1 to DTG12 each including 8 data tracks DT (see FIG. 7). The same applies when data tracks DT are formed in the other data bands DB2 to DB4.
[0053]
Next, playback will be described. Here, it is assumed that the data track group DTG formed by the recording head group WHG is reproduced.
[0054]
At the time of reproduction, first, the data track group DTG1 formed in the data band DB1 by the reproduction head group RHG1 of the head unit HU while the magnetic tape MT is traveling in the forward direction A1 by the tape reel driving device 11 and the device reel driving device 12. Each data track DT included in is reproduced (see FIG. 6A). At this time, since each data track DT of the data track group DTG can always be traced by any one of the data signal reproducing heads RH of the reproducing head group RHG, the data recorded in each data track DT of the data track group DTG is recorded. The signal can be reliably reproduced.
[0055]
Next, after the data track group DTG1 is reproduced by the reproducing head group RHG, the head unit HU is moved by the head unit driving device 17 in the tape width direction B1 of the magnetic tape MT, and the position of the reproducing head group RHG in the data band DB1 ( The position of the magnetic tape MT in the tape width direction B) is moved to the position of the data track group DTG2 ′ formed next to the data track group DTG1 (see FIG. 6B).
[0056]
Then, each of the data tracks DT included in the data track group DTG2 is reproduced by the reproducing head group RHG while the magnetic tape MT is run in the backward direction A2 by the tape reel driving device 11 and the device reel driving device 12 (FIG. 6 ( c)).
[0057]
By repeating the above operation, the data track DT included in each data track group DTG formed in the data band D1 can be reliably reproduced. For example, when twelve data track groups DTG1 to DTG12 are formed in the data band DB1, the head unit HU is magnetically moved during each run while the magnetic tape MT is run six times in the forward direction A1 and the return direction A2. By moving the tape MT in the tape width direction B, the 12 data track groups DTG1 to DTG12 can be reproduced by the reproducing head group RHG1. The same applies to the reproduction of the data track group DTG formed in the other data bands DB2 to DB4.
[0058]
【The invention's effect】
As described above, according to the present invention, it is possible to provide a magnetic tape drive capable of forming data tracks at a higher density in the width direction of the magnetic tape as compared with a conventional magnetic tape drive.
[Brief description of the drawings]
FIG. 1A is a partial plan view of a magnetic tape MT. FIG. 7B is a partially enlarged plan view of the magnetic tape MT in which the portion surrounded by the broken line in FIG.
FIG. 2 is a schematic configuration diagram of a magnetic tape drive 10 according to the present embodiment.
3A is a plan view showing the head unit HU, and FIG. 3B is a partially enlarged plan view of the head unit HU in which a portion surrounded by a broken line in FIG. 3A is enlarged. .
FIG. 4 is a partially enlarged plan view of the head unit HU showing the vicinity of each head in FIG.
FIG. 5 is an explanatory diagram showing a state in which data tracks DT1 to DT3 formed by the data signal recording heads WH1 to WH3 of the recording head group WHG are traced by the data signal reproducing heads RH2 to RH6 of the reproducing head group RHG.
FIG. 6 is a partial plan view of the magnetic tape MT and the head unit HU for explaining the operation of the head unit HU at the time of recording or reproduction, and FIG. 6 (a) shows a case where the data track group DTG1 is recorded or reproduced. (B) shows the state after recording / reproducing the data track group DTG1, and (c) shows the case where the data track group DTG2 is recorded / reproduced.
FIG. 7 is a partial plan view of the magnetic tape MT showing data track groups DTG1 to DTG12 formed in the data band DB1 by the head unit HU.
[Explanation of symbols]
10 Magnetic tape drive
11 Tape reel drive
12 Equipment reel drive
13 Equipment reel
14 Recording current generator
15 Reproduction signal processing circuit
16 Servo signal processing circuit
17 Head unit driving device
18 Control device
19a, 19b Guide
HU head unit
WH data signal recording head
WHG recording head group
RH data signal reproducing head
RHG playback head group
SH Servo signal reading head
MT magnetic tape
ST Servo track
DB data band
DT data track
DTG data track group
GB guard band

Claims (5)

A magnetic tape drive having a head unit comprising a tracking servo head and a recording head group consisting of a plurality of data signal recording heads,
The plurality of data signal recording heads are formed at a pitch corresponding to the pitch of adjacent data tracks on the magnetic tape,
A magnetic tape drive characterized in that a plurality of adjacent data tracks are simultaneously formed on a magnetic tape by the plurality of data signal recording heads. The head unit includes a plurality of data signal reproducing heads and includes a reproducing head group arranged in parallel with the recording head group,
The width of each data signal reproducing head is set narrower than the width of each data signal recording head, and the positions of both ends of the reproducing head group are obtained when the head unit is moved in the tape width direction of the magnetic tape. In order to include a control amount error, in the tape width direction of the magnetic tape, it is set to be outside the both ends of the recording head group,
2. The magnetic tape drive according to claim 1, wherein the plurality of adjacent data tracks are simultaneously reproduced by the plurality of data signal reproducing heads. The number of data signal reproducing heads included in the reproducing head group is such that the number of data signal recording heads included in the recording head group is Nw, the pitch of adjacent data signal recording heads in the recording head group is Pw, and the reproducing is performed. When the pitch of adjacent data signal reproducing heads in the head group is Pr,
3. The magnetic tape drive according to claim 2, wherein more than Nw × (Pw / Pr) +1 is set. The head width of the data signal reproducing head is such that the pitch of adjacent data signal recording heads in the recording head group is Pw,
The magnetic tape drive according to claim 2, wherein the magnetic tape drive is set to Pw × 0.2 or more. The head width of the data signal recording head is set to 2 Wr + Dr or more when Wr is the width of the adjacent data signal reproducing heads in the reproducing head group and Dr is the distance between the adjacent data signal reproducing heads. 3. The magnetic tape drive according to claim 2, wherein

Images