JP2000348319A - Tape drive device and tape drive method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect deviation of the height of a magnetic tape at the time of recording operation. SOLUTION: When approach running in the case of succeeded writing is being performed (S008) in a repositioning operation at the time of recording, data recorded on a magnetic tape are read in and the height deviation is detected on the basis of these data. For the detection of the height deviation, e.g. such a method is adopted in which the occurrence of the height deviation is detected on the basis of the timing when a block ID is detected, the number of detected error correction codes (C1) or the like, and it is discriminated that the height deviation, is present in the case their values are beyond the threshold. When the occurrence of the height deviation is judged, the height deviation is detected again by the retry (S012-S016), and when the height deviation is detected even though the retry is carried out for the specified number of times, the error is fed back (S017) to a host computer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tape drive and a tape drive method.

[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, 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.

[0003] As the above-mentioned tape streamer drive, there is a tape streamer drive which records / reproduces data by employing a helical scan system with a rotary head using, for example, an 8 mm VTR tape cassette as a recording medium. Proposed.

FIG. 15 is a perspective view for explaining the structure of a drum cylinder in which a rotary head is formed in a tape streamer drive. 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. On the rotating drum 72a, a recording head unit 73 including the illustrated recording heads 73a and 73b, and a plurality of reproducing heads 74a and 74b formed at predetermined positions of the rotating drum 72a with respect to the recording head unit 73, for example. A recording head unit 74 including a recording head 74c is provided. The recording heads 74a and 74b and the reproducing heads 73a and 73b have different azimuth angles, respectively.
The structure is such that the two gaps are arranged in close proximity,
The heads have different azimuth angles from each other. That is, for example, the recording head 74a 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 on a frame-by-frame basis (two tracks). Data is read from the frame. Such an operation is called read-after-write (Re
ad_After_Write (hereinafter abbreviated 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.

[0005] When the magnetic tape 91 is wound around the drum cylinder 72 configured as described above by a required tape guide, the result is as shown in FIG. When the magnetic tape 91 is drawn out of the housing of the tape cassette (not shown) by the tape guides 75, 76, 77, 78, it is supported by the tape guide portion 75 of the fixed drum 72b. 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.

[0006]

When data is recorded on a magnetic tape in a tape streamer drive, recording data is supplied from a host computer or the like. In this case, the supplied recording data is stored in a required buffer memory in the tape streamer drive, and then recorded in units of, for example, 20 frames. That is, it is necessary for the buffer memory to store recording data corresponding to at least 20 frames. However, if the transfer speed of the recording data from the host computer is low, the data storage amount in the buffer memory may be less than 20 frames. In such a case, the recording operation is temporarily interrupted, and the apparatus waits until a required amount of recording data is stored in the buffer memory. At this time, the magnetic tape 91 is run in the direction opposite to the recording direction, for example, traces back to the head of the group in which recording was last performed. The operation for recording is restarted according to the instruction. That is, when restarting the recording operation that has been stopped, the magnetic tape 91 is rewound to a position slightly backward from the position where the recording was stopped, and then the magnetic tape is moved in the forward direction to the writing connection position in order to increase the data writing accuracy. By running the tape, recording is resumed from the writing position.
This operation is called repositioning.

[0007] As shown in FIG.
The recording / reproducing head is wound around a rotating drum on which the recording / reproducing head is formed, and runs at a speed relative to the rotating speed of the rotating drum 72a. A so-called height shift may occur in which the positional relationship of the tape 91 shifts from the defined position. If the height shift occurs as described above, the scanning position of the rotating drum 72a with respect to the magnetic tape shifts, and in this state, data cannot be recorded at a position different from the normal position. Therefore, if data recording is performed in such a state where the height is shifted, it is impossible to read data even if a reading operation is performed later at a regular position.

For this reason, when the run-up is performed after a pause, the track is recorded together with the recording data at a predetermined position on a track formed on the magnetic tape, and the level of the tracking state is determined from the level to implement the tracking servo. ATF (Automatic Trac)
k Following) Based on the detection level of the signal (pilot signal), it was determined whether or not writing was performed without any height deviation. However, the ATF signal is a signal provided for performing a stable recording / reproducing operation by guaranteeing the respective tape cassettes to each other, and is capable of following a certain degree of tracking variation. For this reason, it is difficult to detect the height deviation of the tape cassette using only the ATF signal. Also, since the tape streamer drive uses a removable tape cassette as a recording medium, for example, the linearity of the write pattern by the mechanical deck of another tape streamer drive varies, so that the tape cassette can be read only using the ATF signal. There is a problem that it is difficult to discriminate the height deviation.

[0009]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention scans a magnetic tape running in a forward direction so that the magnetic tape has a predetermined angle with respect to the running direction. By recording data by forming a track having, a rotating head capable of reading data recorded on the track, a traveling drive unit for traveling the magnetic tape, and the traveling drive unit, While the drive operation for data recording is being performed on the magnetic tape, if the drive operation is in the standby state at the first position, the magnetic tape is moved in the reverse direction to the second position. Reverse running control means for causing the running drive means to execute tape running backwards;
A forward traveling control unit that causes the traveling drive unit to travel the magnetic tape in a forward direction based on a predetermined operation instruction after the backward traveling control unit goes back to the second position; When the magnetic tape is running in the forward direction from the second position by means,
A tape drive device is provided with magnetic tape position determining means for determining an arrangement state of the magnetic tape with respect to the rotary head based on the content of data read by the rotary head.

Also, as a tape drive method, when a driving operation for recording data on the magnetic tape is being performed and the driving operation is in a standby state at a first position, the magnetic tape A backward traveling step of traveling back to the second position in the reverse direction, and after traveling back to the second position by the reverse traveling means, the magnetic tape is caused to travel in the forward direction based on a required operation instruction. Reading the data stored in the magnetic tape when the magnetic tape is running in the forward direction from the second position in the forward running step, and the content of the read data; A magnetic tape position determining step of determining an arrangement state of the magnetic tape with respect to the rotary head based on the position of the magnetic tape; and Whether to resume driving operation of the recording from the position, or provided with a side step for discriminating the positional state of the magnetic tape.

According to the tape drive device of the present invention, since the height deviation of the magnetic tape can be detected, it is possible to prevent the recording operation from being performed in the state where the height deviation has occurred, It is possible to prevent the recording from being executed on the magnetic tape on which the recording has been performed in the state where the error has occurred. As a tape drive method, when it is determined that the magnetic tape has no height deviation, the recording operation can be continued as it is, and when the height deviation is detected, the height deviation is again detected. Detection can be performed.

[0012]

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 (tape streamer drive) capable of recording / reproducing digital data corresponding to the tape cassette with the memory are described. Various inventions have been proposed, but the present invention is based on the data storage system including the tape cassette with memory and the tape streamer drive applied to the present invention. The nonvolatile memory provided in the tape cassette is 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 Error correction code (C1) 4. 4. Data transfer Reposition

1. First, a tape cassette with an MIC as a contact type memory corresponding to the tape streamer drive of the present embodiment will be described with reference to FIGS. FIG. 2 conceptually shows the internal structure of the tape cassette. The tape cassette 1 shown in FIG. 2 is provided with reel hubs 2A and 2B, and a tape width 8 between the reel hubs 2A and 2B.
mm of magnetic 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 manufacturing date, a manufacturing location, a tape thickness, a length, a material, a use history of recording data for each partition formed on the tape 3 for each tape cassette, and the like. Is stored, user information, and the like. 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
Is basically the same as the configuration of the tape cassette used in the above. 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 a tape streamer drive 10 described below and the terminal pins 7A, 7B, 7
Mutual transmission of data signals and the like is performed by physically contacting via C, 7D, and 7E.

2. Configuration of Tape Streamer Drive Next, referring to FIG.
Will be described. The tape streamer drive 10 is used for the magnetic tape 3 of the loaded tape cassette 1.
Recording / reproduction is performed by a helical scan method. The rotary drum 11 has two recording heads 12A and 12B having different azimuth angles, and three reproducing heads 13A and 13A having respective required azimuth angles.
B and 13C are provided at predetermined angular intervals. The recording heads 12A and 12B are similar to the reproducing heads 13A and 13B,
13C is a recording head 73A shown in FIG.
73B corresponds to the reproducing heads 74A, 74B, 74C.

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), which will be described later, to execute loading / unloading of the magnetic tape 3 onto the rotating drum 11. The eject motor 28 is a motor for driving a loading mechanism of the tape cassette 1, and performs seating of the inserted tape cassette 1 and discharging operation of the tape cassette 1.

The drum motor 14A, the capstan motor 14B, the reel motors 14C and 14D, the loading motor 14E, and the eject motor 28 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.

In order for the servo controller 16 to execute the servo control of each motor, the drum motor 14A, the capstan motor 14B, the T reel motor 14C, and the S reel motor 14D are each provided with an FG (frequency generator). In addition, rotation information of each motor can be detected. That is, a drum FG 29A that generates a frequency pulse synchronized with the rotation of the drum motor 14A, a capstan FG 29B that generates a frequency pulse synchronized with the rotation of the capstan motor 14B, and a T that generates a frequency pulse synchronized with the rotation of the T reel motor 14C. Reel FG2
9C, an S-reel FG29D for generating a frequency pulse synchronized with the rotation of the S-reel motor 14D is formed, and these outputs (FG pulses) are supplied to the servo controller 16. The frequency pulse output from the drum FG29A is a pulse synchronized with the scanning of the rotating drum 11. Therefore, a drum servo reference signal is formed based on the frequency pulse from the drum FG 29A. Further, a timing reference signal is supplied to each of the recording signal generation units 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. The capstan FG29B is, for example, one of the capstan motors 14B.
360 pulses are output per rotation. T reel FG
The 29C and S reel FG29D output 24 pulses per rotation of the T reel motor 14C and S reel motor 14D, respectively.

The servo controller 16 determines the rotation speed of each motor based on these FG pulses,
By detecting an error between the rotation operation of each motor and a target rotation speed and performing an applied power control corresponding to the error to the mechanical driver 17, it is possible to realize a rotation speed control in a closed loop. Accordingly, during various operations such as normal running during recording / reproduction, high speed search, fast forward, and rewind, the servo controller 16 performs control so that each motor is rotated at a target rotation speed according to each operation. Can be. 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 to input and output data.
Is used. For example, at the time of data recording, a fixed-length record (record) is sent from the host computer 40.
Data is sequentially input via the SCSI interface 20 in units of transmission data, and supplied to the compression / decompression circuit 21 via the SCSI buffer controller 26. The SCSI buffer controller 26 controls data transfer of the SCSI interface 20. The SCSI buffer memory 27 is buffer means provided corresponding to the SCSI buffer controller 26 in order to obtain the transfer speed of the SCSI interface 20. 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 / decompression 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, and 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 way, the data of the input character string is registered in the dictionary, and the data compression is performed 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, the data is finally handled as a fixed-length unit corresponding to 40 tracks of the magnetic tape called a group, and the data is subjected to the ECC format processing.

As the ECC format processing, an error correction code (C1, C2, C3) is added to the recording data, and the data is subjected to a modulation processing so as to conform to magnetic recording, and is supplied to the RF processing unit 19.

As a system to which the present embodiment corresponds, there are a plurality of data formats relating to recording / reproducing data for the magnetic tape 3. In this specification, this data format is referred to as an AIT format. The current tape streamer drive 10 employs a configuration capable of supporting two formats of the AIT format, the AIT-1 format and the extended AIT-2 format.

The RF processing unit 19 performs processing such as amplification and recording equalization on the supplied recording data to generate a recording signal, and supplies the recording signal to the recording heads 12A and 12B. As a result, data is recorded on the magnetic tape 3 from the recording heads 12A and 12B.

The data reproducing operation will be briefly described. The data recorded on the magnetic tape 3 is read from the reproducing head 13.
A, 13B, and 13C read out the signal as an RF reproduction signal, and the reproduction output is subjected to reproduction equalization, reproduction clock generation, binarization, decoding (for example, Viterbi decoding), and the like in an RF processing unit 19. In this embodiment, in the data reproducing operation, the height deviation of the magnetic tape 3 is detected based on the number of error correction codes (C1) that can be read in block units. The signal read in this manner is supplied to the IF / ECC controller 22, where the signal is 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 supplied to the compression / decompression circuit 21. Compression / expansion circuit 2
In 1, based on the judgment of the system controller 15,
If data is compressed by the compression / decompression circuit 21 at the time of recording, the data is subjected to data decompression processing here, and if it is uncompressed data, the data is passed without being subjected to data decompression processing and output. The output data of the compression / decompression circuit 21 is SCS
I buffer controller 26, host computer 4 as reproduced data via SCSI interface 20
Output to 0.

FIG. 2 shows the MIC 4 together with the magnetic tape 3 of the tape cassette 1. This MIC4
When the main body of the tape cassette is loaded into the tape streamer drive, it is connected to the system controller 15 via the serial interface 35 with the terminal pins shown in FIG. Thus, the system controller 15 can read the management information recorded in the MIC 4 or update the management information.

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 and the host computer 40. As a result, the exchange of data between the tape cassette and the host computer 40 can be established 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 can instruct the system controller 15 by the SCSI command to execute data writing / reading with respect to the MIC 4.

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.

FIG. 1 shows an example in which the tape cassette 1 provided with the MIC 4 is loaded. However, as the tape streamer drive 10, for example, a tape cassette without the MIC 4 is loaded. In such a case, recording / reproduction can be performed. In this case, since the management information of the tape cassette is recorded in the management area formed on the magnetic tape 3,
The tape streamer drive 10 reads management information recorded on the magnetic tape 3 and updates the management information.

In the embodiment, the MIC 4 of the tape cassette 1 is of a contact type which can communicate with the system controller 15 by contacting a terminal. However, the present invention is also applicable to a system using a non-contact MIC. Applicable. A non-contact MIC is an MIC chip that includes a modulation / demodulation circuit, a communication circuit, and an antenna in the MIC chip, and also has an antenna, a modulation / demodulation circuit, and a communication circuit on the tape streamer drive 1 side, and accesses the MIC by radio wave communication. Is realized. The technique using such a non-contact MIC is described in detail in, for example, Japanese Patent Application No. 10-220352 filed by the present applicant.

FIGS. 4 and 5 show a state in which the magnetic tape 3 derived from the tape cassette 1 is wound around the rotating drum 11 of the tape streamer drive 10. FIG. This drawing shows only the structure of the tape streamer drive 10 in which the tape cassette 1 is inserted, and the tape cassette 1 shows the structure inside the housing. MIC4 is not shown in these figures.

As shown in FIG. 4, the tape cassette 1 is inserted into the insertion opening 41 of the tape streamer drive 10.
When the magnetic tape 61 is inserted from the
1 is a movable tape guide 43, 45, 46, 47, 4 adapted to be able to be guided to a predetermined position.
It is drawn out of the housing of the tape cassette 1 by 8 and 49 and wound around the rotating drum 11. In addition, the tape guide 44 is a tape streamer drive 1 (not shown).
0 is fixedly installed on the chassis of the tape guide 4
The magnetic tape 3 can be sandwiched together with the magnetic tape 3. The pinch roller 50 applies a constant tape tension to the magnetic tape 3 led to the tape guides 47 and 48, and presses the magnetic tape 3 against the outer peripheral surface of the capstan 51.

In the state shown in FIG. 4, the tape streamer drive 10 performs various operations such as recording / reproduction and normal repositioning. As described above, the pinch roller 50 and the capstan 51 are respectively moved at the time of repositioning. When it is separated to a predetermined position in the direction of arrow Z, the result is as shown in FIG. Thus, the magnetic tape 3 is released from the pinch roller 50 and the capstan 51. Hereinafter, in this specification, the state shown in FIG. 4 is the ON state of the pinch roller 50, and the state shown in FIG.
The off state is assumed.

FIG. 6 shows the structure of data recorded on the magnetic tape 3. FIG. 6A schematically shows one magnetic tape 3. In this example, FIG.
As shown in (a), one magnetic tape 3 can be used by being divided in units of partitions. In the case of the system of this example, a maximum of 25 can be used.
The number of partitions can be set and managed. Each partition shown in this figure is
Partitions # 0, # 1, # 2, # 3, etc. respectively
, A partition number is given and managed.

Therefore, in this example, data recording / reproduction can be performed independently for each partition. For example, the data recording unit in one partition shown in FIG. FIG. 6 (c)
Can be divided into fixed-length units called groups, and recording on the magnetic tape 3 is performed in units of each group. In this case, 1
The group corresponds to the data amount of 20 frames (Frame), and as shown in FIG. 6D, one frame is formed by two tracks (Track). In this case, the two tracks forming one frame are adjacent azimuth and minus azimuth tracks. Therefore, one group is formed by 40 tracks.

The data structure of one track shown in FIG. 6D is shown in FIGS. 7A and 7B. FIG. 7A shows a data structure in block units. One block is one byte of SYN
Following the C data area A1, it is formed of a 6-byte ID area A2 used for searching and the like, a 2-byte error correction parity area A3 for ID data, and a 64-byte data area A4.

The data for one track shown in FIG. 7B is formed by a total of 471 blocks, and one track has four blocks of margin area A at both ends as shown in the figure.
11 and A19 are provided.
ATF areas A12 and A18 for tracking control are provided behind and before the margin A19. Furthermore, A
Parity areas A13 and A17 are provided after the FT area A12 and before the ATF area A18. As the parity areas A13 and A17, areas for 32 blocks are provided.

An ATF area A15 is provided in the middle of one track, and these ATF areas A13 and A13 are provided.
Areas for 5 blocks are provided as 15 and A18. Then, the parity area A13 and the ATF area A
15, ATF area A15 and parity area A
17 and 192 blocks of data areas A14 and A16, respectively. Therefore, all data areas (A14 and A16) in one track occupy 192 × 2 = 384 blocks of all 471 blocks. The tracks are physically recorded on the magnetic tape 3 as shown in FIG. 7C, and as described above, 40 tracks (= 20 frames) form one group.

3. Error Correction Code (C1) FIG. 8 is a diagram illustrating an error correction code (C1) corresponding to, for example, block-based error correction as an error correction code added to recording data by ECC format processing. The error-correcting code (C1) is interleaved every two blocks, for example, as shown in FIG.
As shown in (a), the error correction code is formed of 12 bytes following data (52 bytes) behind two consecutive blocks. That is, the 64-byte data shown in FIG. 8B can be represented as the even data shown in FIG. 8C and the odd data shown in FIG. 8D. The error correction code (C1) is a total of 12 bytes of data including the last 6 bytes of even data and the last 6 bytes of odd data. Since this error correction code (C1) is provided every two blocks,
Parities 13A and 17A, data 1 shown in FIG.
22 in a total of 448 blocks of 4A and 16A
Four will be stored. That is, if the magnetic tape 3 has no height deviation, 224 error correction codes (C1) are detected. Although detailed description is omitted, the error correction code (C2) is, for example, an error correction code corresponding to one track, and the error correction code (C3) is an error correction code corresponding to one group.

4. Data Transfer FIG. 10 is a diagram for explaining the transition of data transfer performed between the host computers 40 in the tape streamer drive 10, for example. As described above, the host computer 40 and the tape streamer drive 10
By SI (for example, Wide SCSI), for example, 4
Data transfer is performed at a transfer rate of 0.0 Mbyte / sec. The data supplied to the tape streamer drive 10 is stored in a required transfer unit in the SCSI buffer memory 27 composed of, for example, 2 Mbytes. SCS
The data stored in the I buffer memory 27 is, for example, 2
The data is transferred to the buffer memory 23 at a transfer rate of 0.0 Mbyte / sec, and data in groups is constructed in the buffer memory 23. Then, data is read from the buffer memory 23 at a transfer rate of, for example, 6.0 Mbytes / sec, and recording is performed on the magnetic tape 3 in groups. When data is reproduced, data read from the magnetic tape 3 is stored in the buffer memory 23 in group units. Then, the reproduction data in units of groups read into the buffer memory 23 is transferred to the SCSI buffer memory 27 as data in units of transfer, and transferred to the host computer 40 by SCSI.

The timing at which the repositioning is performed is, for example, that the data stored in the buffer memory 27 is equal to or less than a predetermined amount (for example, an empty state) at the time of recording, that is, there is no data to be written on the magnetic tape 3. It is assumed that the writing standby state has been reached. When the relationship between the transfer rate B of the transfer path between the tape streamer drive 10 and the host computer 40 and the transfer rate A between the buffer memory 23 and the magnetic tape 3 satisfies A> B, repositioning is performed and A <B If so, the streaming is continued. However, the transfer rate A between the buffer memory 23 and the magnetic tape 3 is fixed. in this way,
The repositioning is performed according to the amount of data stored in the buffer memory 23. Therefore, at the time of recording, repositioning is performed after writing a certain group. At the time of reproduction, it is assumed that the data read out to the buffer memory 23 is full and the read-out standby state is set.

5. Repositioning In the present embodiment, a height recovery of the magnetic tape is detected at the time of repositioning during recording, and a required recovery process is performed. Note that the height deviation is different from the arrangement in which the magnetic tape 3 and the rotating drum 11 are defined. Therefore, if recording is performed in a state where a height shift occurs, the track formed by this recording will not be formed with a regular inclination.

FIG. 10 is a schematic diagram for explaining a repositioning operation when there is no height deviation, for example. FIG. 10A shows data (frame units) recorded on the magnetic tape 3 before the repositioning. FIG. 10B shows the transition of the repositioning, and FIG. 10C shows the data recorded on the magnetic tape after the repositioning. FIG.
At 0 (a) and (c), reference positions R are indicated by broken lines to indicate the position of each frame with respect to the rotary head 11, and
It is assumed that there is no height shift in the illustrated state.

As a normal recording operation, when data is recorded in group units such as Group N-1 and Group N at FWD × 1 (1 × speed in the forward direction), the above-described conditions such as the transfer rate are used. The buffer memory 2
When the data of the group N + 1 to be recorded subsequent to the group N is not stored in No. 3, the recording standby state is established and the repositioning is performed.

In the example shown in FIG.
1B shows an example in which recording has been performed up to the position P1 shown in FIG. 1B, but when recording up to the 20th frame of the group N is completed, writing is continued until the position P1 is reached following the 20th frame. For example, five amble frames are recorded. Note that the amble frame shown in FIG. 11A is shown as a postamble frame, as it is recorded following the twentieth group. After that, the magnetic tape 3 is rewound from the position P1 at RVS × 3 (3 × speed in the reverse direction), goes back to, for example, the head of the group N shown as the position P2, shifts to the operation standby state, and shifts to the host computer, for example. Wait for an operation start instruction supplied from 40. Then, when a required amount of data is accumulated in the buffer memory 23 and the operation start instruction is received, reproduction is performed at FWD × 1 as a run-up to resume recording, and recording operation is resumed at FWD × 1 from position P3. I do. As shown in the figure, since the position P3 is a position corresponding to the postamble frame 3, recording (writing) is restarted by overwriting the postamble frames 3, 4, and 5. . As a result, for example, as shown in FIG. 11C, the preamble frames 2 and 3 are recorded after the postamble frame 2, and then the first frame, the second frame,... N + 1 data are recorded. As a result of the repositioning, three amble frames are recorded between the group N and the group N + 1 to form a rewritten portion.

In the present embodiment, from position P2 to position P3
During the reproduction period in, for example, the fourteenth group N
The height deviation of the magnetic tape 3 with respect to the rotary head 11 is detected based on the detection state of data of five frames from the nineteenth frame to the nineteenth frame. This is because the detection process can be performed after a required traveling speed is obtained by the approaching run. FIG. 11 shows, for example, the block I of each block stored in the frame.
It is a figure explaining the example which detects height gap based on the timing which D is detected. As described with reference to FIG. 7A, each block stores a block ID as its identification information. This block ID is stored in a block corresponding to the parity A13, A17 and data A14, A16 shown in FIG. Therefore, a specific block ID is recorded at a specific position from the start position of the track. In other words, when the magnetic tape 3 is scanned by the rotary head 11, if the magnetic tape 3 has no height deviation, the same block I
D can be detected at a predetermined timing.

First, in FIG. 11, taking an even frame et as an example, if the magnetic tape 3 is further scanned after detecting the block ID (nb), for example, as shown by a broken line, Even frame e of track
The block ID (nb) of t can be detected. That is, the predetermined block ID (nb) is
At a timing corresponding to the predetermined rotation cycle.
When the height shift occurs, the magnetic tape 3 is not arranged at a regular position with respect to the rotating drum 11 as described above, and thus the position of the specific block ID is also out of the scanning locus of the rotating head. And the detection timing is different. In other words, based on the FG pulse of the rotating drum 11, a predetermined block ID (nb) is detected on the basis of, for example, the falling timing of the drum servo reference signal generated corresponding to the rotation cycle of the rotating drum 11. The height deviation can be detected by measuring the measured timing and determining the measured timing. The even-numbered frame et is, for example, a azimuth frame corresponding to the azimuth angle of the reproducing head 13A. Therefore, the odd frame ot is a frame having an azimuth angle corresponding to, for example, the reproducing head 13B.

The block ID (nb) is, for example, an I corresponding to a block near a scanning start portion of a track.
D, the timing at which the block ID (na) located behind the block ID (nb) in the track is detected for the odd frame ot is measured. Thus, for example, in the scanning start portion, even if the block ID (nb) cannot be detected for some reason, the height deviation can be detected by the block ID (na). In the example shown in FIG. 11, for example, a block ID (nb) at a position about 1/4 from the beginning of the track and a block ID (n) at a position about 3/4 from the beginning of the track.
a) is taken as an example, but the block ID to be detected
Can be set arbitrarily according to the use of the system.

The detection of the height shift can be performed based on the number of error correction codes (C1) that can be read in the height shift detection section in addition to measuring the timing of the block ID. As shown in FIG. 8, the error correction code (C1) is assigned corresponding to the blocks forming the frame. Therefore, when there is no height deviation in the magnetic tape 3, for example, 224 error correction codes (C1) can be detected for one track. However, when a height shift occurs, the number of error-correcting codes (C1) that can be read also decreases because the tracks formed on the magnetic tape 3 do not match the scanning of the reproducing head. Therefore, for example, 224 error correction codes (C1) in one track
Is detected, it can be determined that there is no height shift. However, in practice, a slightly lower value is set as the threshold value in consideration of an error at the time of reading. Note that these height deviation detection methods may be performed individually, but when used together, height deviation detection with higher accuracy can be performed. Further, in this embodiment, an example has been described in which 224 error correction codes (C1) are stored in one track, but this is merely an example, and for example, in different tape formats, the numerical values are not necessarily the same.

In this manner, the height deviation can be detected. When it is determined that there is no height deviation,
As shown in FIG. 10B, the operation shifts from the position P3 to the recording operation, and the data of the group N + 1 is written on the magnetic tape 3 following the preamble frame 3.

FIG. 12 is a diagram for explaining a retry when a height shift occurs. In addition, the position P shown in the figure is allotted with a different letter for convenience in order to correspond to the operation transition, but for example, the position P2, the position P5, and the position P6 indicate the same position. Similarly to the case described with reference to FIG. 10, when a height shift occurs when recording is performed to the position P1 and then going back to the position P2, a height shift detection section (for example, In the 14th to 18th frames), the height deviation is detected. This corresponds to the shift amount H in FIG.
It is shown as In this case, as shown in FIG. 12B, the position P5 is again shifted from the position P4 by RVS × 3.
Return to the top of group N shown as. And
After turning off the pinch roller 50 and once releasing the magnetic tape 3 from the pinch roller 50 and the capstan 51,
Reproduction is performed at FWD × 1 from the position P6, and height deviation detection is performed again in the height deviation detection period. From position P2 to position P4
When the height shift occurs in the transition to the position P5, the pinch roller 50 is turned off when returning to the position P5.
As shown in (c), the deviation amount H is corrected, and the magnetic tape 3 can be returned to the normal height. As a result, for example, in the second height shift detection, it is determined that there is no height shift, and the process proceeds to the recording operation from the position P7, and the group N + 1 is recorded following the preamble frame 3 without any height shift. Will be able to continue.

FIG. 13 is a diagram for explaining a retry when a track is recorded in a state of height deviation. Also in this figure, for example, position P2, position P5, position P
6, position P10, position P11, and position P4, position P7
Indicates the same position. As shown in FIG. 13A, for example, the 19th frame and the 2nd frame of the group N-1
0, and the post-amble frames 2, 3, 4, 5, etc. of the group N, as shown in FIG.
Are arranged at the reference position R, but the recording positions of the frames formed between the above-mentioned frames are shifted. In this case, as shown in FIG. 13B, an abnormality is detected in the detection of the track position from the position P2 to the position P4, so that the pinch roller 50 is turned off by returning to the position P5 at triple speed. Then, in the reproducing operation from the position P6, the track position is detected again. However, since the actually recorded track position is recorded in a state where the height is shifted, it is also detected that the track position is shifted in this case as well. The result is obtained. Therefore, as shown at positions P9, P10, and P11, retracing of retracing, reproduction, and height deviation detection is repeated, but the actually recorded track is deviated from the normal position. Therefore, even if the magnetic tape 3 is arranged so that there is no height deviation by turning off the pinch roller 50, the position of the track is in a different state. Therefore, although not shown in the figure, the retry is repeated a required number of times after the position P12, and if the normality is not detected, it is determined that unusable data is recorded, and an error notification is sent to the host computer 40. I do.

As shown in this figure, when a height shift occurs on a magnetic tape on which recording has been performed in a state where a height shift has occurred, depending on the recorded track and the height shift, the block ID may be changed. Detection timing and error correction code (C1)
It is conceivable that the number of detections becomes equal to the state without the height shift. Assuming such a case, the pinch roller 5 must be set at the time when the writing of the amble frame is completed and the head returns to the head (position P2) of the group by RVS × 3.
The on / off control of 0 may be performed. As a result, the height deviation of the magnetic tape 3 is corrected and the magnetic tape 3 returns to a normal position, and the detection timing of the block ID and the number of detected error correction codes (C1) have threshold values corresponding to the height deviation. .

FIG. 14 is a flow chart showing the processing transition of the height deviation detection in the repositioning at the time of recording described with reference to FIGS. It is determined whether or not the storage amount of the recording data in the buffer memory 23 has become equal to or less than a predetermined amount (S001). If it is determined that the amount has become equal to or less than the predetermined amount, a variable N for retry count counting is initialized to "1".
(S002). Further, a postamble frame is recorded (S003), and the magnetic tape is
The vehicle runs in the reverse direction at S × 3 (S004). Then, it is determined whether or not the head has returned to the head of the group N recorded last (S005). If it is determined that the head has reached the head of the group N, the apparatus waits in that state (S006) and operates from the host computer 40. Wait for start instruction (S00
7).

When the operation start instruction is supplied from the host computer 40, the reproducing operation is started (S008), and the height deviation is detected in the height deviation detection section (S00).
9). In this case, the height deviation detection is based on the timing at which the block ID is detected or the number of error correction codes (C1) detected within one track, as described above. Then, it is determined whether or not a height shift has been detected (S010). If it is determined that there is no height shift, the operation shifts to a recording operation (S011), and after the preamble frame 3 has been recorded, the data of the group N + 1 Record. Also, if a height shift is detected,
The value of the retry count variable N is determined (S012).
Then, for example, if it is equal to or less than "7", the retry count variable N is counted up (S013),
The magnetic tape is run in the reverse direction at, for example, RVS × 3 (S
014), it is determined whether or not it has returned to the head of group N (S015). If it is determined that the magnetic tape 1 has been moved back to the head of the group N, the control to turn on / off the pinch roller 50 is performed, and the magnetic tape 1 is temporarily moved to the pinch roller 5.
After releasing from 0, the flow returns to step S008 to start reproduction and detect a height deviation (S009), and further determine the detection result of the height deviation detection (S010). If no height deviation is detected here, for example, FIG.
As described in 2 above, it is determined that the track position has returned to the normal position by the retry, and the operation shifts to the recording operation (S01).
1).

Further, a height shift is detected in step S010, and the processing steps from step S012 to step S016 are repeated, for example, seven times, and then the step S010 is repeated.
If a height deviation is detected at 010, it is determined that recording is being performed with the height deviation occurring with respect to the magnetic tape 3 as described with reference to FIG. (S0
17). That is, when the process reaches step S017, it is possible to determine that data is being recorded on the tape cassette 1 currently loaded in the tape streamer drive 10 in a state where reproduction is not possible.

As described above, in the repositioning operation at the time of recording, it is possible to detect the height deviation based on the read data. Therefore, it is possible to correct a high displacement. Further, if recording has already been performed in a state of height deviation, the recording operation after the detection of height deviation can be stopped, and a tape cassette on which data that cannot be reproduced is recorded is created. Can be suppressed.

Although the present embodiment has been described by taking the height deviation of the magnetic tape as an example, it is also possible to detect a track bend using a similar detection method.
That is, even when the track is bent, the scanning of the rotary head 11 does not correspond to the track, so that the timing at which a specific block ID is detected,
The number of detected error correction codes (C1) in one track is also different from a normal value. That is, the present invention identifies a magnetic tape having a curved track, and similarly to a case where recording is performed due to a height deviation, a tape cassette on which data that cannot be reproduced by continuing recording is recorded. Can be suppressed.

[0063]

As described above, the tape drive according to the present invention can be repositioned during recording.
The height deviation of the magnetic tape can be detected. Therefore, with respect to the magnetic tape on which recording is performed due to the height deviation, it is possible to stop continuing the further recording operation, and it is possible to perform recording and reproduction with the track shifted. It is possible to prevent recording of impossible data. That is, the recording operation can be continuously performed only when it is determined that there is no height deviation. In addition, even if a height deviation occurs during repositioning, the height deviation can be detected and corrected by repositioning again. can do.

The height deviation can be detected by, for example, the timing at which specific identification information recorded on each track is detected or the number of error correction codes detected in block units. The detection can be performed by reading recorded data.

In the tape drive method of the present invention, a deviation in height of the magnetic tape is detected during repositioning during recording, and recording is restarted based on the position state of the magnetic tape. Is determined again. Therefore, when there is no height deviation, the recording operation can be continued as it is, and when the height deviation is detected, the height deviation is detected again, and the height deviation is no longer detected. To perform the recording operation.

[Brief description of the drawings]

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

FIG. 2 is a diagram schematically showing an internal structure of the tape cassette according to the embodiment.

FIG. 3 is a perspective view showing the appearance of the tape cassette according to the embodiment.

FIG. 4 is a diagram illustrating a state in which a pinch roller is “on” in the tape streamer drive according to the present embodiment.

FIG. 5 is a diagram illustrating a state where a pinch roller is “off” in the tape streamer drive according to the present embodiment.

FIG. 6 is an explanatory diagram of a data structure on a magnetic tape of the tape cassette according to the present embodiment.

FIG. 7 is an explanatory diagram of a track structure on a magnetic tape of the tape cassette according to the present embodiment.

FIG. 8 is an explanatory diagram of an error correction code (C1) in block units according to the present embodiment.

FIG. 9 is a diagram illustrating an outline of data transfer between the tape streamer drive and the host computer according to the present embodiment.

FIG. 10 is a diagram illustrating transition of repositioning when there is no height shift.

FIG. 11 is an explanatory diagram when a specific block ID in a track is detected.

FIG. 12 is a diagram illustrating transition of repositioning when a height shift occurs due to repositioning.

FIG. 13 is a diagram illustrating a transition of repositioning when data recording is performed in a state where a height shift has occurred.

FIG. 14 is a flowchart illustrating a process transition of height deviation detection at the time of repositioning in the present embodiment.

FIG. 15 is an explanatory diagram of a drum cylinder.

FIG. 16 is a diagram showing a state where a magnetic tape is wound around a drum cylinder.

[Explanation of symbols]

1 tape cassette, 3 magnetic tape, 10 tape streamer drive, 11 rotating drum, 12A, 12B
Recording head, 13A, 13B, 13C reproducing head,
15 system controller, 19 RF processing unit, 22
IF / ECC controller, 23 buffer memory,
27 SCSI buffer memory, 29A drum FG, 4
0 Host computer

Claims (6)

[Claims] 1. A magnetic tape running in a forward direction is scanned to form a track having a predetermined angle with respect to a running direction on the magnetic tape, thereby recording data. A rotating head capable of reading data recorded on the magnetic tape; a traveling drive unit for traveling the magnetic tape; and a driving operation for recording data on the magnetic tape performed by the traveling drive unit. Reverse running control means for causing the running drive means to execute tape running so that the magnetic tape goes back in the reverse direction to the second position when the driving operation is in the standby state at the first position. And after returning to the second position by the reverse traveling control means, forwards the magnetic tape to the traveling driving means based on a predetermined operation instruction. Forward traveling control means for causing the magnetic tape to travel in the forward direction from the second position by the forward traveling control means based on the contents of data read by the rotary head. And a magnetic tape position determining means for determining an arrangement state of the magnetic tape with respect to the rotary head. 2. The magnetic tape position judging means judges an arrangement state of the magnetic tape based on a timing at which specific identification information recorded on each track formed on the magnetic tape is detected. 2. The tape drive device according to claim 1, wherein: 3. The magnetic tape according to claim 1, wherein the track is formed from a plurality of blocks, and the magnetic tape position determining means determines a tape position based on the number of detected error correction codes in block units recorded on the magnetic tape. The tape drive device according to claim 1, wherein the tape drive device is adapted to perform the operation. 4. The apparatus according to claim 1, further comprising a recording control unit that restarts a driving operation for recording from the first position based on a result of the determination by the magnetic tape position determining unit. Tape drive device. 5. The tape drive according to claim 1, further comprising a retry control unit that performs a tape position determination process based on a determination result of the magnetic tape position determination unit. 6. When a driving operation for recording data on the magnetic tape is being performed and the driving operation is in a standby state at a first position, the magnetic tape is moved in a reverse direction. A backward traveling step of traveling back to the second position, and a forward traveling step of traveling forward the magnetic tape based on a required operation instruction after traveling back to the second position by the reverse traveling means. Reading the data stored in the magnetic tape when the magnetic tape is traveling in the forward direction from the second position in the forward traveling step, and performing the rotation based on the content of the read data. A magnetic tape position determining step of determining an arrangement state of the magnetic tape with respect to a head; and a driving operation for restarting recording from the first position based on the position state of the magnetic tape. Performing the operation or re-determining the position of the magnetic tape.