JP2000123444A - Tape drive device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect a tilt amount of a track due to positional deviation of a magnetic tape. SOLUTION: When it shifts to a write period, a count value of a position counter is reset, and while the count value is 3 or below (read period), following processing are performed (S001-S003). When a waveform of a pilot signal is detected, the position counter is counted up, and further, whether the count value is '1' or '3' is discriminated (S004-S006). When the count value is '1' or '3', the pilot signal of the timing of the count value is stored in an operation part. Then, the pilot signals (the top, the rear of the track) answering to the count values '1', '3' are extracted, and required operation processing are performed for respective pilot signals (S007-S009), and when the operation result is a prescribed value or above, the processing corresponding to the positional deviation of the magnetic tape are executed (S010).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tape drive capable of detecting the inclination of a track recorded on a magnetic tape.

[0002]

2. Description of the Related Art A so-called tape streamer drive is known as a drive device capable of recording / reproducing digital data on / from a magnetic tape. Such a tape streamer drive can have an enormous recording capacity of, for example, about several tens to several hundreds of gigabytes, depending on the tape length of a tape cassette as a medium. It is widely used for such purposes as backing up data recorded on media. It is also suitable for use in storing image data having a large data size.

As the above-mentioned tape streamer drive, there is a tape streamer drive which records / reproduces data by adopting a helical scan method using a rotary head using a tape cassette of 8 mm VTR as a recording medium. Proposed.

FIG. 13 shows a state in which a magnetic tape 91 derived from a tape cassette 90 is wound around a drum cylinder 72 of a tape streamer drive 70. This drawing shows only the configuration of the tape streamer drive 70 where the tape cassette 90 is inserted, and the tape cassette 90 shows the structure inside the housing.

[0005] As shown in FIG. 13, a rotatable tape supply reel 92 and a take-up reel 93 are arranged inside a tape cassette 90 so that a magnetic tape 91 can be wound thereon. . That is, the magnetic tape 91 is fed in the forward or reverse direction by the rotation operation of each reel. Tape cassette 9
0 is inserted from the insertion opening 71 of the tape streamer drive 70, the magnetic tape 91 is
, A movable tape guide 73, 75, 76, 77, 78,
It is derived from the housing of the tape cassette 90 by 79,
It is wound around the drum cylinder 72. The tape guide 74 is provided with a tape streamer drive 7 (not shown).
0 as a fixed type, and a tape guide 7
3 together with the magnetic tape 91. The pinch roller 80 applies a certain tape tension to the magnetic tape 91 led to the tape guides 77 and 78, and presses the magnetic tape 91 against the outer peripheral surface of the capstan 81.

FIG. 14 is a perspective view illustrating the structure of the drum cylinder 72. As shown, the drum cylinder 72 includes a rotating drum (rotating head) 72a and a fixed drum 7 rotatably supporting the rotating drum 72a.
2b. The rotating drum 72a has a reproducing head 73 composed of the reproducing heads 73a and 73b shown in the drawing, and a recording head 74a formed on the diagonal of the rotating drum 72a with respect to the reproducing head 73, for example.
A recording head unit 74 composed of a recording head 74b is provided. Recording heads 74a, 74b and reproducing heads 73a, 73b
The head has a structure in which two gaps having different azimuth angles are arranged extremely close to each other, and the heads have different azimuth angles. That is, for example, the recording head 74
a and the reproducing head 73a, and the recording head 74b and the reproducing head 73b have the same azimuth angle. At the time of recording, recording is performed on the magnetic tape 91 by the two recording heads 74a and 74b for each frame (two tracks).
In b, data is read from the frame previously written by the recording head. Such an operation is called read-after-write (Read_After_Write ...
(Hereinafter referred to simply as RAW). Further, a tape guide portion 75 is formed on the fixed drum 72b so as to project a part of the outer peripheral surface thereof.

When the magnetic tape 91 is wound around the drum cylinder 72 constructed as described above, the result is as shown in FIG. The state shown in FIG. 15 corresponds to the state in which the drum cylinder 72 is shown in FIG. That is, the magnetic tape 91 is attached to the tape guides 75 and 7.
6, 77, 78, the stationary drum 72
b) supported by the tape guide portion 75. Thus, the rotation of the rotary drum 72 a causes the reproducing head 73 and the recording head 74 to scan obliquely with respect to the running direction of the magnetic tape 91.

That is, tracks are formed on the magnetic tape 91 in a direction oblique to the running direction of the magnetic tape 91 as shown in FIG. For example, as shown in FIG. 16A, when the longitudinal direction of the magnetic tape 91 corresponds to the horizontal direction, the scanning direction of the rotary drum 72a has a required angle with respect to the tape running direction. Is done. Therefore, each track formed on the magnetic tape 91 is formed obliquely to the tape running direction. FIG. 16A shows a recording head 74a,
74b shows one frame consisting of two adjacent tracks formed almost simultaneously as a unit. The number assigned to each frame corresponds to the frame number, and detailed description is omitted.
One group is formed by 0 frames (40 tracks).

FIG. 16A shows an outline at the time of recording. For example, several "0" frames are shown next to 20 frames. This is a frame for performing overwriting.

FIG. 16B shows a transition when repositioning is performed. When the actual recording speed is higher in the tape streamer drive 70 than in the transfer speed at which the data to be recorded is supplied to the tape streamer drive 70, the data supplied to the tape streamer drive 70 The recording operation is started with the data stored in a buffer memory or the like provided. In this case, the tape streaming drive 70 waits for a recording operation until a required data amount is accumulated. Then, when the required amount of data is accumulated, the recording operation is started. After the magnetic tape 91 is once driven in the reverse direction to some extent, the magnetic tape 91 is driven in the forward direction to search for a recording position. Do. This operation is called repositioning. That is, as shown in FIG. 16B, the transition is shown in FIG. 16B. For example, the frame is run at 3 × speed in the reverse direction from the position where the overwritten frame “0” is recorded, and the frame is reproduced by 25 frames, and the reproduction is performed from the position where the frame is advanced. Start and search for overlaid frames. Then, as shown in FIG. 16C, data writing is started from the position next to the position where the overwrite frame “0” is detected. In this figure, the frames recorded before and after the repositioning are identified by hatched documents.

[0011]

The repositioning operation is repeated many times when a large amount of data is transferred to the tape streamer drive at a relatively low speed. In this case, the magnetic tape 9
1 means that the forward running and the backward running are repeated, whereby the magnetic tape 91 is moved to the tape guide portion 75.
A phenomenon of sliding up from the surface occurs. That is, the magnetic tape 91 runs while being wound around the drum cylinder 72 in a state of being shifted from the normal position. Hereinafter, such a phenomenon is referred to as a position shift of the magnetic tape.

As described above, when data is recorded in a state where the magnetic tape 91 is not accurately wound around the drum cylinder 72, that is, in a state where the magnetic tape is displaced, the running direction of the magnetic tape 91 and the scanning direction of the rotating drum 72a are changed. Is different from the normal state, and the tracks are formed on the magnetic tape 91 at an inclination different from the normal. For example, as shown in FIG. 17, assuming that the inclination angle θ1 is a regular inclination angle with respect to the longitudinal direction of the magnetic tape 91, the recording head is moved with respect to the running direction of the magnetic tape 91 due to the inclination displacement. Is shifted, and tracks (frames) having, for example, inclination angles θ2, θ3, and θ4 are formed. Where R
When performing AW, since the recording heads 74a and 74b and the reproducing heads 73a and 73b are mounted on the same rotating drum 72a, they scan the same trajectory and can reproduce the recorded track.

However, if the data recorded when the magnetic tape 91 is misaligned is reproduced again while the magnetic tape 91 is wound around the regular position of the drum cylinder 72, the locus of the reproducing head is recorded on the track. If they do not match, the track cannot be scanned accurately. Therefore, there arises a problem that recorded data cannot be reproduced.

[0014]

SUMMARY OF THE INVENTION The present invention solves such a problem by running a tape-shaped recording medium in a predetermined direction and scanning the tape-shaped storage medium with a rotary head. In a tape drive device capable of performing recording by forming a track having a predetermined angle with respect to a running direction of the tape-shaped recording medium and reproducing the track, Pilot signal detection means for detecting a pilot signal recorded at a predetermined position,
A pilot signal extracting means for extracting at least two pilot signals in the track detected by the pilot signal detecting means; and a required arithmetic processing on at least two pilot signals extracted by the pilot signal extracting means. The tape drive device comprises: an arithmetic processing unit for performing the calculation; and a track inclination amount detection unit capable of detecting the inclination amount of the track based on a calculation result of the arithmetic processing unit.

According to the present invention, the amount of inclination of the track with respect to the scanning direction of the rotating drum can be detected based on the detected pilot signal. Accordingly, it is possible to execute a corresponding process for correcting, for example, a displacement of the magnetic tape in accordance with the amount of tilt.

[0016]

Embodiments of the present invention will be described below. Here, a tape cassette provided with a non-volatile memory by the present applicant and a tape drive device forming a data storage system capable of recording / reproducing digital data corresponding to the tape cassette with the memory will be described. However, it is assumed that the present invention is applied to a data storage system corresponding to these tape cassettes with memory. Note that the nonvolatile memory provided in the tape cassette is referred to as an MIC (Memory In Cassette). The description will be made in the following order. 1. 1. Configuration of tape cassette 2. Configuration of tape streamer drive 3. Pilot signal recording system 4. Pilot signal reproduction system Detection of track tilt amount with respect to scanning direction of rotating drum

1. First, the MI corresponding to the tape streamer drive of this example
The tape cassette with C will be described with reference to FIGS. FIG. 2 conceptually shows the internal structure of the tape cassette. A reel hub 2A, 2B is provided inside the tape cassette 1 shown in FIG. 2, and a magnetic tape having a tape width of 8 mm is provided between the reel hubs 2A, 2B. The tape 3 is wound.

The tape cassette 1 is provided with an MIC 4 which is a nonvolatile memory, and five terminals 5A, 5B, 5C, 5D, 5E are provided from a module of the MIC 4.
Are derived and configured as a power supply terminal, a data input terminal, a clock input terminal, a ground terminal, a spare terminal, and the like. As will be described in detail later, the MIC 4 includes a date of manufacture, a place of manufacture, and a magnetic tape 3 for each tape cassette.
The information related to the thickness, length, material, use history of recording data for each partition formed on the magnetic tape 3, and the like, user information, and the like are stored. In this specification, various types of information stored in the MIC 4 are also referred to as “management information”.

FIG. 3 shows an example of the external appearance of the tape cassette 1. The entire housing is composed of an upper case 6a and a lower case 6.
b and guard panel 8, a normal 8mm VTR
The configuration is basically the same as that of the tape cassette used in the first embodiment. Label surface 9 on the side of this tape cassette 1
Are provided with terminal pins 7A, 7B, 7C, 7D, 7E, and the terminals 5A, 5B, 5
C, 5D, and 5E, respectively. That is, in this example, the tape cassette 1 is composed of the tape streamer drive 10 described below and the terminal pins 7A, 7B, 7C, 7
D and 7E make physical contact with each other to perform mutual transmission of data signals and the like.

Next, the configuration of the tape streamer drive 10 of this embodiment will be described with reference to FIG. The tape streamer drive 10 performs recording / reproduction on the magnetic tape 3 of the loaded tape cassette 1 by a helical scan method. The rotary drum 11 is provided with, for example, two recording heads 12A and 12B and two reproducing heads 13A and 13B. The rotary drum 11 is a drum cylinder 7 shown in FIGS.
2 corresponds to the rotary drum 72a. That is, the recording heads 12A and 12B have a structure in which two gaps having different azimuth angles are arranged extremely close to each other, and the reproducing heads 13A and 13B are also heads having different azimuth angles. Therefore, two recording heads 12A,
The RAW operation is performed by 12B and the reproducing heads 13A and 13B.

The data of the frame read by the RAW in this manner is subjected to error detection by the system controller 15, and when it is detected that an error has occurred, the data of the frame in which the error has occurred is reproduced. The recording signal processing system is controlled to perform writing.

The rotary drum 11 around which the magnetic tape 3 drawn from the tape cassette 1 is wound is rotated by a drum motor 14A. A capstan (not shown) for moving the magnetic tape 3 at a constant speed is driven to rotate by a capstan motor 14B. The reel hubs 2A and 2B in the tape cassette 1 are independently rotated in the forward and reverse directions by the reel motors 14C and 14D, respectively. The loading motor 14E drives a loading mechanism (not shown) to execute loading / unloading of the magnetic tape 3 onto the rotating drum 11.

The drum motor 14A, the capstan motor 14B, the reel motors 14C and 14D, and the loading motor 14E are driven to rotate by the application of power from the mechanical driver 17. The mechanical driver 17 drives each motor based on the control from the servo controller 16. The servo controller 16 controls the rotation speed of each motor to run during normal recording / reproducing, running at high speed, running tape at fast-forward and rewind, loading a tape cassette, loading / unloading, and loading tape. Control operation, and the like. Although not shown, the drum motor 14A, the capstan motor 14B, and the reel motors 14C and 14D are provided with FGs (frequency generators) in order for the servo controller 16 to execute the servo control of each motor. The rotation information of each motor can be detected. The servo controller 16 determines the rotation speed of each motor based on these FG pulses, thereby detecting an error between the rotation speed of each motor and the target rotation speed, and controlling the applied power corresponding to the error. Is performed on the mechanical driver 17, it is possible to realize the rotation speed control in a closed loop. Therefore, normal driving during recording / reproduction,
During various operations such as high-speed search, fast-forward, and rewind, the servo controller 16 can perform control so that each motor is rotated at a target rotation speed corresponding to each operation.

The EEP-ROM 18 stores constants used by the servo controller 16 for servo control of each motor.

The servo controller 16 has an interface controller / ECC formatter 22 (hereinafter, IF)
/ ECC controller), and is bidirectionally connected to a system controller 15 that executes control processing of the entire system.

In the tape streamer drive 10, a SCSI interface 20 is used for data input / output.
Is used. For example, at the time of data recording, data is sequentially input from the host computer 40 via the SCSI interface 20 in a transmission data unit of a fixed-length record and supplied to the compression / decompression circuit 21.
In such a tape streamer drive system, there is also a mode in which data is transmitted from the host computer 40 in units of variable-length data sets.

The compression / expansion circuit 21 performs a compression process by a predetermined method if necessary for the input data. As an example of the compression method, for example, LZ
If a compression method using codes is adopted, in this method, a special code is assigned to a character string processed in the past and stored in the form of a dictionary. Then, the character string to be input thereafter is compared with the contents of the dictionary. If the character string of the input data matches the code of the dictionary, the character string data is replaced with the code of the dictionary. Data of the input character string that does not match the dictionary is sequentially given a new code and registered in the dictionary. In this manner, the data of the input character string is registered in the dictionary, and the data is compressed by replacing the character string data with the code of the dictionary.

The output of the compression / decompression circuit 21 is IF / EC
The output of the compression / expansion circuit 21 is temporarily stored in the buffer memory 23 by the control operation of the IF / ECC controller 22. The data stored in the buffer memory 23 is
Under the control of the / ECC controller 22, data is finally handled as a fixed-length unit corresponding to 40 tracks of a magnetic tape called a group, and ECC format processing is performed on the data.

In the ECC format processing, an error correction code is added to the recording data, and the data is subjected to a modulation processing so as to conform to magnetic recording.
It is supplied to the F processing unit 19. The RF processing unit 19 performs processing such as amplification and recording equalization on the supplied recording data to generate a recording signal, and the recording heads 12A and 12A.
B. As a result, data is recorded on the magnetic tape 3 from the recording heads 12A and 12B. In this figure, the IF / ECC controller 22 and R
The F processing unit 19 is indicated by a dashed line for convenience in the recording / reproducing system 30.
, Which is, as described later, an ATF (Au
tomatic Track Following) Pilot signal recording /
This is because it corresponds to a part to be reproduced.
The pilot signal is a signal that is recorded at a predetermined position on a track formed on the magnetic tape 3 and is recorded to determine whether the tracking state is good or not from the level thereof. Further, a recording signal processing system of the pilot signal including the IF / ECC controller 22 and the RF processing unit 19 will be described later in detail with reference to FIG.

The data reproducing operation will be briefly described. The data recorded on the magnetic tape 3 is read from the reproducing head 13.
A and 13B read out as an RF reproduction signal, and the reproduction output thereof is reproduced by the RF processing unit 19 for reproduction equalizing, reproduction clock generation, binarization, and decoding (for example, Viterbi decoding).
And so on. The signal read in this way is I
The data is supplied to the F / ECC controller 22 and first subjected to error correction processing and the like. The data is temporarily stored in the buffer memory 23, read out at a predetermined time, and
1 is supplied. IF / ECC controller 2
2. By the recording / reproducing system including the RF processing unit 19 and the like,
A reproduction signal processing system for the pilot signal is configured,
This will be described later in detail with reference to FIG.

In the compression / expansion circuit 21, based on the judgment of the system controller 15, if the data has been compressed by the compression / expansion circuit 21 at the time of recording, data expansion processing is performed here. The data is passed and output without performing the data decompression processing. Output data of the compression / decompression circuit 21 is output to the host computer 40 as reproduction data via the SCSI interface 20.

FIG. 2 shows the MIC 4 together with the magnetic tape 3 of the tape cassette 1. This MIC4
When the tape cassette body is loaded in the tape streamer drive, it is connected so that data can be input and output to and from the system controller 15 via the terminal pins shown in FIG. As a result, the system controller 15
4 can be read or the management information can be updated.

MIC 4 and external host computer 40
During this time, mutual transmission of information is performed using SCSI commands. Therefore, especially the MIC 4 and the host computer 4
It is not necessary to provide a dedicated line between the tape cassette 1 and the host computer 40. As a result, the exchange of data between the tape cassette 1 and the host computer 40 can be connected only by the SCSI interface.

Information is transmitted between the tape streamer drive 10 and the host computer 40 using the SCSI interface 20 as described above.
Performs various communications using SCSI commands. Therefore, the host computer 40 instructs the system controller 15 by the SCSI command to
Data writing / reading for C4 can be executed.

S-RAM 24, flash ROM 25
Stores data used by the system controller 15 for various processes. For example, the flash ROM 25 stores constants and the like used for control. The S-RAM 24 is used as a work memory or a memory used for storing data read from the MIC 4, data to be written to the MIC 4, mode data set in units of tape cassettes, various flag data, and arithmetic processing. You. The S-RAM 24 and the flash ROM 25 may be configured as an internal memory of a microcomputer constituting the system controller 15, or may be configured to use a part of the area of the buffer memory 23 as a work memory.

3. Pilot signal recording system An outline of a pilot signal recording operation performed by the recording heads 12A and 12B formed on the rotary drum 11 shown in FIG. 1 will be described with reference to the schematic diagram of FIG. In FIG. 4, a width TW indicates a recording width of each of the recording heads 12A and 12B, and a width TP indicates a track pitch which is, for example, about 1/3 of the recording width TW. Each track shown is actually recorded diagonally on the magnetic tape 3 as shown in FIG.

First, as shown in FIG. 4A, data is recorded with a recording width TW (approximately three times the track pitch TP) by the recording head 12A which is arranged ahead in the rotation direction of the rotary drum 11. (Track Tr1) is performed. A recording signal recorded as a track by the recording head 12A is formed by, for example, a data section composed of data supplied from an external device to the tape streamer drive 10, a mask section, a pilot signal P1, and a data section. The mask section is the recording head 12 (A,
This is a section in which recording current is not supplied to B). The hatching given to each section corresponds to the azimuth direction of the recording head.

Next, as shown in FIG. 4B, following the track Tr1, the track Tr2 is recorded by the recording head 12B. The track Tr2 is overwritten on the track Tr1 with a width of, for example, 2 TP. The recording operation of the recording head 12B is slightly delayed due to the positional relationship between the recording head 12B and the recording head 12A, but is performed almost simultaneously to form one frame. As shown in the figure, in the track Tr2, a position corresponding to the pilot signal P1 of the track Tr1 is set as a mask section, and the data section is written without erasing the pilot signal P1. In the recording head 12B, writing of a pilot signal is not performed.

The track Tr2 is generated by the recording head 12B.
Is recorded by the recording head 12A with respect to the track Tr2 as shown in FIG.
r3 is overwritten. In this case, the mask section of the track Tr2 is located at a position corresponding to the pilot signal P1 of the track Tr1, so that the pilot signal P1 of the track Tr1 is not erased. Then, a new pilot signal P2 is written.

Further, following the track Tr3, FIG.
As shown in (d), the track Tr4 is written by the recording head 12B. In this case, as in the case of the track Tr2, the position corresponding to the pilot signal P2 is set as the mask section. Will not be erased.

As described above, the recording is performed by the recording heads 12A and 12B, for example, at the transitions shown in FIGS. 4A to 4D, whereby the pilot signal is recorded at a predetermined position on the track. As will be described later with reference to FIG. 9, the pilot signal is formed at, for example, three points at the head, center, and rear of each track.

An example of a functional configuration of the recording / reproducing system 30 shown in FIG. 1 for performing the recording operation shown in FIG. 4 will be described with reference to FIG. 5 as a recording signal processing system 30W.
As shown in the figure, two paths are shown to supply a required recording current to each of the recording heads 12A and 12B. That is, the recording head 12A,
12B, the recording signal generation units 51a, 51
b, recording amplifiers 52a and 52b are provided. That is, the recording signal generation unit 51a includes the tracks Tr1, Tr3
.. Are supplied with recording data and a pilot signal for generating a recording current for forming. The frequency of the pilot signal is, for example, lower than the frequency of the recording data, and is set to a value that enables good overwriting. The recording signal generation unit 51b includes the track T
Recording data for generating a recording current for forming r2, T4r... is supplied.

Further, a timing reference signal is supplied to each of the recording signal generators 51a and 51b. This timing reference signal is formed by, for example, a drum servo reference signal and is a signal synchronized with the scanning of the rotating drum 11.

FIG. 6 shows the timing of the recording operation in the recording signal processing system 30W. The write enable signal WEN1 for controlling the recording timing supplied from the recording signal generation unit 51a to the recording amplifier 52a is set to a high level in the periods t1 and t2, and the period t3
At low level. Also, the write enable signal WE
N2 has the same waveform as the write enable signal WEN1, but has a delay amount τ corresponding to the gap related distance where the recording heads 12A and 12B are arranged. When the timing shown in FIG. 6 corresponds to FIG. 4, for example, in the write enable signal WEN1, the data section is in the period t1, the pilot signal is in the period t2, and the mask section is in the period t3.
It corresponds to. That is, the recording of the pilot signal is performed at the timing of the period t2. On the other hand, for the write enable signal WEN2, a high-level period corresponds to, for example, a data period, and a low-level period corresponds to, for example, a mask period.

By performing writing at such a timing, a track as shown in FIG. 4 can be formed. In this example, when a reproducing operation is performed on the track formed on the magnetic tape 3 in this manner, a pilot signal is detected, and the inclination of the track accompanying the displacement of the magnetic tape is detected from the level of the pilot signal. Try to identify the quantity.

4. Pilot signal reproducing system A functional example of the recording / reproducing system 30 shown in FIG. 1 for reproducing a track formed as described with reference to FIGS. 30R
FIG. In this figure, the rotating drum 11
Of the two reproducing heads 13 provided in the first embodiment, only the reproducing head 13 is shown.
It is assumed that the recording head 12A and the recording head 12A have the same azimuth and the reproducing head 13A reproduces the pilot signal.

A reproduction signal read from the magnetic tape 3 by the reproduction head 13A is supplied to an analog signal processing unit 55 via a reproduction amplifier 54. The analog signal processing unit 55 includes a gain control unit 56, a waveform detection unit 57, and an amplification unit 5.
8, a rectangle processing unit 59 and the like. The gain controller 56 is controlled by the system controller 15, for example, to change the characteristics of the magnetic tape 3 or the like.
Variation correction such as a recording level is performed. The reproduction signal whose gain has been corrected by the gain control unit 56 is supplied to the waveform detection unit 57 and the rectangularization unit 59. The waveform detecting section 57 detects a waveform of a predetermined cycle corresponding to a pilot signal from the reproduced signal via the gain control section 56 and supplies the detected signal to the digital signal processing section 60 via the amplifying section 58. In addition, the rectangular section 59 outputs a required reference voltage ref.
The reproduction signal is made rectangular based on the
Supply 0. The waveform output from the rectangularization section 59 rises at, for example, a portion corresponding to a pilot signal.

The analog signal processing section 55 performs power saving control based on the switching pulse supplied from the system controller 15. For example, during the RAW operation (while the rotating drum is rotating), the timing at which the recording heads 12A and 12B are not recording, that is, the reproduction head 13
In a state where A and 13B are scanning the magnetic tape 3, power saving of the analog signal processing unit 55 is realized. That is, when the switching pulse SWP is at a high level, for example, a data reading period is set, and when the switching pulse SWP is at a low level, a power saving period is set. Therefore, the pilot signal is read during the reproduction period in which the switching pulse SWP is at the low level. In this example, as described later, the position of the pilot signal in the track is specified based on the timing of the switching pulse SWP.

The digital signal processing section 60 includes an A / D conversion section 6
1, a pattern detection unit 62, a sampling control unit 63, a memory 64, a counter 65, a calculation unit 66, and the like. The A / D converter 61 is a sampling controller 5
The control section 9 converts the pilot signal P detected by the waveform detection section 59 into digital data based on the control of Step 9. The pattern detection unit 62 outputs a pilot signal P based on a rectangular signal corresponding to the pilot signal P supplied from the rectangularization unit 59.
Is detected. When the position of the pilot signal P is detected, the pattern detection unit 62
9 to output a required control signal. Thus, A
In the / D conversion section 61, A / D conversion is performed at the timing of the pilot signal P. Therefore, the memory 62 stores sequentially digitized pilot signals.

The position counter 65 counts the timing of the pilot signal P detected by the pattern detector 62 during the period when the switching pulse SWP is turned on. Thus, by associating the currently detected pilot signal P with the count value of the position counter 65, it becomes possible to identify whether the pilot signal is the head, center or rear of the track.

The operation section 66 extracts, for example, two pilot signals P recorded at the beginning and the rear of the track identified by the count value of the position counter 65, performs necessary operation processing, and performs an operation based on the operation result. Thus, the inclination of the track on which the pilot signal P is recorded can be detected.

FIG. 8 is a timing chart schematically showing timings of the switching pulse SWP, the pilot signal P, and the position counter 65. The switching pulse SWP shown in FIG.
There is a write period in which the signal goes high during one rotation of one, and a read period in which the signal goes low. That is, power saving is realized during the read period. FIG.
(B) shows the timing at which the control signal is output in the sampling control unit 63 as the timing corresponding to the pilot signal, for example, as shown in FIG.
Will be detected. Further, as shown in FIG. 8C, the count value of the position counter 65 is counted up at the timing when the pilot signal is detected, that is, at the control timing of the sampling control unit 63. Therefore, the count value corresponding to the pilot signal is “1” at the beginning, “2” at the center, and “3” at the rear.
The reset is performed at the time when the read period ends, for example, at the rising timing of the write period. As a result, it is possible to identify which position in the track the pilot signal currently detected is based on the count value of the position counter 65.

5. Next, an example of detecting a pilot signal recorded on a track at the time of reproduction will be described with reference to FIGS. 9 to 11. FIG. 9A shows a state in which the track is properly inclined with respect to the scanning direction of the rotating drum 11. In this case, the trajectory R1 of the reproducing head 13A and the inclination of the track substantially coincide with each other, so that the reproducing head can perform almost accurate scanning on the track. In this case, the first pilot signal Pa (Pa1, Pa2), the central pilot signal Pb (Pb1, Pb2), and the rear pilot signal P in the same track
As shown in FIG. 9B, the levels of c (Pc1, Pc2) are all substantially the same. Note that before and after the pilot signal, a signal that is meaningless as data of a single cycle is recorded in order to perform a PLL (Phase Locked Loop) when performing various signal processings, for example. This makes it possible to detect some data when reproducing the data of the track, so that a reproduction clock can be generated.

However, as shown in FIGS. 10 and 11, the tracks are recorded at an angle different from the normal angle due to the displacement of the magnetic tape 3, and thereafter the magnetic tape 3
Is played in the correct position,
The trajectory R1 (scanning direction) of the reproducing head 13A does not match the inclination of the track, and the level of the detected pilot signal is different. For example, as shown in FIG. 10A, if the track is inclined more forwardly (downward to the left in the drawing) with respect to the traveling direction of the magnetic tape 3 than the regular inclination, the track becomes as shown in FIG. As shown, when the first pilot signals Pa1 and Pa2 are compared, the level of the pilot signal Pa1 is changed to the level of the rear pilot signal Pc.
1, when Pc2 is compared, the level of pilot signal Pc2 decreases. Similarly, as shown in FIG. 11 (a), the track is more inclined than the regular tape.
11B, the level of the pilot signals Pa1 and Pa2 when the pilot signals Pa1 and Pa2 are compared with each other as shown in FIG. The rear pilot signal Pc
1, when Pc2 is compared, the level of pilot signal Pc1 decreases. That is, as can be seen from FIGS. 10 and 11, when the scanning direction of the rotating drum 11 does not match the inclination of the track, the level of the detected pilot signal also differs. In the example shown in this figure, the center portion of the track, that is, the pilot signals Pb1 and Pb2
Since a state in which an inclination shift occurs around the vicinity is shown, the level change is not shown for the pilot signals Pb1 and Pb2.

As described above, a difference in the level of the pilot signal occurs due to the inclination of the track. In this embodiment, the amount of inclination is detected based on this level difference. For example, the first pilot signal Pa (Pa1, Pa2) is
rr1, rear pilot signal Pc (Pc1, Pc2)
Is Err3, for example, the inclination amount X is

(Equation 1) Can be shown as Therefore, according to the above formula,
It is possible to obtain the inclination of the track with respect to the scanning direction of the rotating drum 11, and to determine whether or not the amount of inclination X is larger than a required threshold value, thereby performing required control corresponding to the amount of inclination X. Will be able to

FIG. 12 is a flowchart for explaining the processing transition of the system controller when detecting the inclination of the track. The processing shown in FIG. 12 is performed, for example, when performing repositioning, or when performing tracking during normal recording or reproduction. As described earlier with reference to the timing of the switching pulse SWP in FIG. 8, in the write period (rising of the switching pulse SWP) (S001), the count value of the position counter 65 is reset (= 0) (S002). And
While the count value is 3 or less (S003), that is, during the read period, the following processing is performed. First, it is determined whether or not the waveform (rectangular wave) of the pilot signal is detected by the pattern detection unit 58 (S004). If it is determined that the waveform of the pilot signal is detected, the position counter 65 is counted up (S005). ). Then, it is determined whether or not the count value after the count is “1” or “3” (S006). If the count value is “1” or “3”, the pilot signal at the timing of the count value is stored in the recording area of the calculation unit 63 (S007).

As described above, by going from step S003 to step S007, the count value of the position counter 65 is incremented to "1", "2", "3", and the count value is "1". , "3", the leading and trailing pilot signals (Pa, Pc) in one track can be identified and extracted. Then, as shown in the above equation, Err1 and Err
Calculation processing for obtaining the inclination amount of the track from rr3 is performed (S008), and the result of the calculation processing is determined (S00).
9). If the calculation result is equal to or greater than the required threshold value, a process corresponding to the displacement of the magnetic tape 3, such as turning off the pinch roller, is executed (S010). If the calculation result is less than the predetermined value,
Assuming that the track has no tilt or, for example, even if the track has tilt, it does not affect normal recording and reproducing operations, the process returns to step S001 to detect the pilot signal of the next track and detect the tilt of that track. Move on to processing.

The control corresponding to the inclination of the track in step S010 is performed, for example, by turning off the pinch roller as described above, or by unloading the tape cassette itself from the tape streamer drive, for example, and May be canceled. That is, the arrangement of the magnetic tape 3 is
Can be guided so that the scanning direction becomes a regular inclination. Further, in this example, an example is described in which, for example, two pilot signals at the beginning and the rear of a track are extracted and the amount of inclination is detected based on these two pilot signals. The tilt amount of the track may be detected based on the levels of the three pilot signals at the center and the rear.

[0059]

As described above, the tape drive of the present invention detects a pilot signal recorded at a predetermined position on a track, and based on at least two pilot signals in the track, detects a magnetic tape. The scanning direction of the rotary head with respect to the upper track can be monitored. Therefore, the detected pilot signal causes the magnetic tape to run in a state deviated from the proper arrangement position for some reason, so that the scanning direction of the rotary head and the inclination amount of the track are different from the normal angle. It becomes possible to recognize the state. In addition, since the position of the pilot signal in the track can be specified based on the start of the track reproducing operation by the rotating head, a required pilot signal, for example, at the beginning or the rear of the track, can be selectively extracted. Will be able to This makes it easy to select a pilot signal effective for detecting the amount of tilt. Further, when it is recognized based on the pilot signal that the magnetic tape is running abnormally, it is possible to perform processing such as returning the running state to normal and re-recording. This makes it possible to improve the reliability of recording and reproducing data on the magnetic tape.

[Brief description of the drawings]

FIG. 1 is a block diagram of a tape streamer drive according to an embodiment of the present invention.

FIG. 2 is a view schematically showing an internal structure of a tape cassette.

FIG. 3 is a perspective view showing an appearance of the tape cassette.

FIG. 4 is a diagram illustrating a transition of a recording operation of a pilot signal.

FIG. 5 is a diagram illustrating a configuration example of a recording signal processing system for a pilot signal.

FIG. 6 is a diagram illustrating the timing of a recording operation of a pilot signal.

FIG. 7 is a diagram illustrating a configuration example of a reproduced signal processing system of a pilot signal.

FIG. 8 is a diagram illustrating timing when a pilot signal is detected.

FIG. 9 is a diagram illustrating a scanning direction of a track on a magnetic tape and a rotating drum.

FIG. 10 is a diagram illustrating a track (different inclination) on a magnetic tape and a scanning direction of a rotating drum.

FIG. 11 is a diagram illustrating tracks (different inclinations) on a magnetic tape and a scanning direction of a rotating drum.

FIG. 12 is a flowchart illustrating a process transition for detecting a pilot signal and obtaining a track inclination.

FIG. 13 is a diagram illustrating a state in which a magnetic tape is led out in the tape streamer drive.

FIG. 14 is a perspective view showing the drum cylinder shown in FIG.

FIG. 15 is a diagram showing a state where a magnetic tape is wound around the drum cylinder shown in FIG. 14;

FIG. 16 is a diagram illustrating a track formed on a magnetic tape and a repositioning operation.

FIG. 17 is a diagram illustrating the angle of a track formed on a magnetic tape.

[Explanation of symbols]

1 tape cassette, 3 magnetic tape, 10 tape streamer drive, 15 system controller, 19
RF processing unit, 22 IF / ECC controller, 30
R playback signal processing system, 40 host computer, 55
Analog signal processing section, 56 gain control section, 57 waveform detection section, 59 rectangular section, 60 digital signal processing section, 61 A / D conversion section, 62 pattern detection section, 63
Sampling control unit, 64 memories, 65 position counter, 66 calculation unit, P (Pa, Pb, Pc)
Pilot signal, SWP switching pulse

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Takao Hiramoto 6-7-35 Kita-Shinagawa, Shinagawa-ku, Tokyo F-term in Sony Corporation (reference) 5D042 FA02 GA02 HA05 HA12 HB01 HC02 5D097 AA06 BB01 BB03 EE03 FF01 FF15 GG06 HH12 HH25 LL08 LL12

Claims (2)

[Claims] 1. A track having a predetermined angle with respect to a running direction of the tape-shaped recording medium by running the tape-shaped recording medium in a predetermined direction and scanning the tape-shaped storage medium by a rotating head. A tape drive device adapted to perform recording by forming a track and to reproduce the track, wherein a pilot signal detecting means for detecting a pilot signal recorded at a predetermined position of the track is provided. A pilot signal extracting means for extracting at least two pilot signals in a track detected by the pilot signal detecting means; and a required arithmetic processing on at least two pilot signals extracted by the pilot signal extracting means Operation processing means for performing Tape drive device, characterized in that it comprises a track inclination amount detecting means capable of detecting the inclination amount of the track are. 2. The apparatus according to claim 1, wherein said pilot signal extracting means is capable of specifying a position of a pilot signal in said track with reference to a start time of a reproduction operation of said track by said rotary head. The tape drive device according to claim 1, wherein: