JP2000100024A - Magnetic recording device and magnetic reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a magnetic recording device and a magnetic reproducing device enabled to recover recording or reproduction without specially adding a backup head thereto when a head trouble occurs. SOLUTION: When a head trouble detecting circuit 15 detects which head is in trouble, connection of a memory with a head in a signal processing circuit 7 is changed in the combination, so that recording or reproduction is carried out with a normal head and further a target track is traced by changing a phase of a drum 16 or a tape 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic recording apparatus and a magnetic reproducing apparatus, and more particularly to a magnetic recording apparatus and a magnetic recording apparatus suitable for use in a helical scan type data recorder, video tape recorder or tape streamer. It relates to a playback device.

[0002]

2. Description of the Related Art Many data recorders or video tape recorders record or reproduce data by helical scanning. That is, the recording head or the reproducing head is mounted on a predetermined rotating drum and rotated, and recording or reproducing is sequentially performed in a direction oblique to the longitudinal direction of the magnetic tape running while being wound around the rotating drum. A data recorder is often used as a tape streamer for sequentially recording data supplied from a host computer.

In such a helical scan type tape streamer, a helical track is provided in a diagonal direction of a magnetic tape in order to record data as a tape format. If a failure occurs in the magnetic head that records or reproduces data on the helical track, the recording or reproducing operation cannot be performed normally.

[0004] Examples of failures that occur in a magnetic head include a so-called clog or the like that causes clogging due to the attachment of a magnetic material peeled from a magnetic tape to a magnetic head, or attachment of minute dust or dust. There is a case due to an internal factor due to a disconnection of a power supply line for exciting a coil of a magnetic head.

When a failure such as a head clog or a disconnection occurs in the recording head or the reproducing head, recording or reproduction on a helical track to be recorded or reproduced by the failed head becomes impossible. In order to return to a state where normal recording or reproduction is possible, it was necessary to stop and repair the operation of the streamer.

As a measure against head failure, it is conceivable to adopt a configuration in which even if data is lost by about one track due to the addition of an error correction code, there is no problem in actual use. However, if a failure occurs in the recording head and a non-recorded portion of one or more tracks is formed on the tape, a PLL (Phase Lock L / L) is generated during reproduction.
There is also a possibility that problems such as difficulty in locking the oop) may occur, and this is not allowed in a tape streamer that emphasizes data reliability.

Further, in order to repair the tape streamer, it is necessary to stop the operation of the entire computer system to which the tape streamer is connected. For this reason, depending on the operation mode of the system, repair itself for recovery from a head failure may itself be a serious problem. If a recording head failure occurs during file writing and recording becomes impossible, a system including a tape streamer and a host computer for protecting unrecorded data in the buffer memory becomes complicated.

In order to solve these problems, a so-called DT (Dynamic Tracking) head, in which the head height is variable by bimorph or the like, is added as a backup head in the event of a head failure, and the DT head replaces the failed head. Japanese Patent Laid-Open No. Hei 8-
007245. However, there is a problem that the restriction on the head arrangement design in the drum increases.

[0009]

SUMMARY OF THE INVENTION An object of the present invention is to provide a magnetic recording apparatus capable of performing a recording or reproducing recovery operation without adding a backup head such as a DT head when a head failure occurs. An object of the present invention is to provide a magnetic reproducing apparatus.

[0010]

According to a first aspect of the present invention, there is provided a magnetic recording apparatus which scans a magnetic tape in an oblique direction with respect to a running direction of the magnetic tape, and scans the oblique recording area of the magnetic tape. At least two or more recording means for recording signals, an abnormality detection unit for detecting an abnormality of the recording means, a recording signal processing system for supplying a recording signal corresponding to the recording means, and a recording signal processing system. A switching unit that switches a combination of connections with the recording unit, and controls the combination of the connections of the switching unit based on the abnormality detected by the abnormality detection unit, and controls the rotation phase of the rotating body on which the recording unit is mounted and the phase of the magnetic tape. And a control unit.

According to a second aspect of the present invention, the recording signal processing system is a storage means.

According to a third aspect of the present invention, when recording is performed again on the oblique recording area of the magnetic tape which has not been normally recorded when the abnormality is detected by the abnormality detecting unit, the control unit controls the rotating body. At least one of the rotation phase and the phase of the magnetic tape is changed from the phase at the time of normal operation, and a recording unit other than the recording unit that has detected an abnormality, and a recording signal processing system that supplies a signal that has not been recorded normally. The connection of the switching unit is controlled so that the connection is established.

According to a fourth aspect of the present invention, there is provided a magnetic reproducing apparatus which scans a magnetic tape in an oblique direction with respect to a running direction of the magnetic tape and reproduces a signal in an oblique recording area of the magnetic tape. An abnormality detection unit that detects an abnormality of the reproducing unit; at least two or more reproduction signal processing systems supplied with signals from the reproduction unit; and a switching unit that switches a combination of connections between the reproduction unit and the reproduction signal processing system. And a control unit that controls the combination of the connections of the switching unit based on the abnormality detected by the abnormality detection unit, and controls the rotation phase of the rotating body equipped with the reproducing unit and the phase of the magnetic tape.

According to a fifth aspect of the present invention, in the magnetic reproducing apparatus, the reproduction signal processing system is a storage unit.

According to a sixth aspect of the present invention, in the case where the reproduction is performed again on the oblique recording area of the magnetic tape which has not been normally reproduced when the abnormality is detected by the abnormality detection unit, the control unit may control the rotation of the rotating body. At least one of the rotation phase and the phase of the magnetic tape is changed from the phase at the time of normal operation, and reproduction means other than the reproduction means that has detected an abnormality, and a reproduction signal processing system to which a signal that has not been normally reproduced is to be supplied. The connection of the switching unit is controlled so as to connect

Next, the operation will be described. In the magnetic recording device,
When a failure occurs in a certain recording means, a signal to be recorded is not normally recorded on the magnetic tape. When the portion is re-recorded by a retry operation or the like, since the abnormality detecting unit has detected which recording unit is abnormal, the control unit, based on the information, determines the recording unit other than the recording unit in which the abnormality is detected. Is selected, and the switching unit is controlled so as to connect the recording signal processing system holding the signal that has not been normally recorded to the selected recording unit. Note that the retry operation refers to an operation for recovery in which recording or reproduction is performed again when recording or reproduction is not normally performed.

Further, the control section controls the rotation phase of the rotating body on which the recording means is mounted or the phase of the magnetic tape in accordance with the selected recording means, so that the recording is performed at the tape phase to be recorded. For this reason, signals that have not been recorded normally are correctly recorded on the magnetic tape.

Similarly, if a failure occurs in a certain reproducing means in the magnetic reproducing apparatus, a signal to be reproduced from the magnetic tape cannot be normally reproduced. When the part is reproduced again by a retry operation or the like, since the abnormality detecting unit detects which reproducing means is abnormal, the control unit, based on the information, reproduces the reproducing means other than the reproducing means in which the abnormality is detected. Is selected, and the switching unit is controlled so as to connect the selected reproduction means to a reproduction signal processing system for processing a signal that has not been reproduced normally.

Further, since the control unit controls the rotation phase of the rotating body on which the reproducing means is mounted or the phase of the magnetic tape in accordance with the selected reproducing means, the signal of the magnetic tape which has not been reproduced is reproduced. Therefore, a signal that has not been reproduced normally is supplied to a reproduced signal processing system to be processed.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention relates to a head failure
The recovery operation is performed by using the remaining normal heads as substitute heads. Note that the recovery operation refers to a recovery operation. Embodiments of a magnetic recording apparatus and a magnetic reproducing apparatus according to the present invention will be described with reference to FIGS.

First, the head configuration is shown in FIG. As recording heads, there are an A-channel recording head 1 and a B-channel recording head 2, which are provided on the scanner 3 at positions facing each other by 180 degrees. Further, there are an A-channel reproducing head 4 and a B-channel reproducing head 5 as reproducing heads, and these are also provided on the scanner 3 at positions opposed to each other by 180 degrees.

Next, the electric system blocks will be described with reference to FIG. The signal processing circuit 7 includes a memory peripheral portion 8 for recording data and a memory peripheral portion 9 for reproduction data. The recording data is output from the signal processing circuit 7 to a predetermined recording head via the recording amplifiers 10 and 11. Reproduction data from the two reproduction heads is sent to the signal processing circuit 7 via the reproduction amplifiers 12 and 13.

The control circuit 14 outputs recording ON / OFF control signals S1 and S2 which can be independently controlled for the recording amplifiers 10 and 11 of each channel.
ON / OF for recording of B channel recording head 2
I can do F.

A signal from each head is input to a head failure detection circuit 15 so that a failure of each head can be detected. This failure detection information is input to the control circuit 14. As a specific method of fault detection, 1) a fault is determined by measuring the amplitude of an RF reproduction waveform. For example, in the case of a recording head, it is possible to operate the reproducing head for a short period in a specific section of the track during recording and measure the amplitude. 2) Failure is determined by measuring the impedance of the head winding. 3) The ECC (error correction) unit in the signal processing circuit 7 knows from the error correction information S3 that data corresponding to a certain head is continuously in error, and determines that a head failure has occurred. However, the present invention is not limited to these.

Further, the control circuit 14 outputs a drum servo control signal S4 to the drum 16 on which the scanner 3 is mounted, and a capstan servo control signal S5 to the capstan 17. The drum servo control signal S4 controls the rotation speed and rotation phase of the drum 16, and the capstan servo control signal S4
Numeral 5 controls the speed and phase of the tape 6 via the capstan 17, and controls the correspondence between the head and the track on the tape 6 by coordination of these.

Next, a detailed configuration of the memory peripheral section 8 for recording data and the memory peripheral section 9 for reproduced data in the signal processing circuit 7 of FIG. 2 will be described with reference to FIG. Switch R1
The switching of the positions R1, R2, and R3 in FIG.
Can be switched by the recording data output destination control signal S6. Similarly, switching of the positions P1, P2, and P3 in the switch P19 is also interlocked, and can be switched by a reproduction data write control signal S7 from the control circuit 14.

The memory 20 for recording data and the memory 21 for reproduction data are each divided into two areas. The area A22 of the recording data memory stores data to be recorded by the A-channel recording head 1, and the area B23 of the recording data memory stores data to be recorded by the B-channel recording head 2. The area A24 stores data reproduced by the A-channel reproduction head 4, and the area B25 of the reproduction data memory stores data reproduced by the B-channel reproduction head 5.

Normally, the switch R18 is in the position R
1, the switch P19 is in the position P1, and the data from the print data memory area A22 is transferred to the A-channel printhead 1 by the print data memory area B.
The data from 23 is supplied to the B channel recording head 2. Similarly, data from the A-channel reproduction head 4 is written to the area A24 of the reproduction data memory, and data from the B-channel reproduction head 5 is written to the area B25 of the reproduction data memory.

When a head abnormality is detected and a recovery operation is performed, the switch position of the switch R18 or the switch P19 is switched according to the head in which the abnormality has occurred. If the A-channel recording head 1 is abnormal, the switch R18 is switched to the position R2. The data in the recording data memory area A22 is supplied to the B channel recording head 2, and the data in the recording data memory area B23 is not output to any head. If the B-channel recording head 2 is abnormal, the switch R18 is switched to the position R3. The data in the area B23 of the recording data memory is supplied to the A-channel recording head 1, and the data in the area A22 of the recording data memory is not output to any head.

When the A-channel reproducing head 4 is abnormal, the switch P19 is switched to the position P2. Data from the B-channel reproducing head 5 is written to the area A24 of the reproduction data memory, and nothing is written to the area B25 of the reproduction data memory. When the B-channel reproducing head 5 is abnormal, the switch P19 is switched to the position P3. The data from the A-channel reproducing head 4 is stored in an area B2 of the reproduced data memory.
5, and nothing is written in the area A24 of the reproduction data memory.

In this embodiment, the memory for recording and the memory for reproduction are divided as described above. However, both memories may be shared. Each memory is divided into two areas, and the data bus is switched by a switch R18 and a switch P19.
By dividing the area for the channel head and the area for the B channel head and controlling the memory address instead of switching the data bus by a switch, a method of associating a signal of an arbitrary head with an arbitrary memory area at the time of recovery can be used. May be used.

FIG. 4 shows a track pattern of a normal helical truck. During recording, tracks such as A1 and A2 are written by the A-channel recording head 1 and tracks such as B1 and B2 are written by the B-channel recording head 2 by the drum servo control signal S4 and the capstan servo control signal S5. Also, at the time of reproduction, A1,
Tracks such as A2 are reproduced by the A-channel reproducing head 4, and tracks such as B1 and B2 are reproduced by the B-channel reproducing head 5.

The operation when a failure is detected in the recording head with the above-described configuration will be described in detail, taking a case where clogging occurs in the B-channel recording head 2 as an example. FIG. 5 shows a track pattern on the tape in this case. Tracks B 1, B 2, etc. indicated by dotted lines are tracks to be originally recorded by the B channel recording head 2, but normal recording is not performed due to the clog of the B channel recording head 2. On the other hand, since the A-channel recording head 1 is normal, tracks such as A1 and A2 are normally written.

During recording, if a failure of the B-channel recording head 2 is detected by the head failure detection circuit 15, the information is sent to the control circuit 14 and the control circuit 1
4 operates as follows. <Step 1> The tape 6 is pre-rolled (starting at the tape position where the failure of the B channel recording head 2 has occurred).

<Step 2> The switch R18 is moved to the position R1 by the recording data output destination control signal S6.
Switch from (normal position) to position R3. By this operation, data to be originally written by the B channel recording head 2, that is, the area B of the recording data memory
23 data is supplied to the A channel recording head 1.

<Step 3> The drum 16 is rotated at a phase shifted by 180 degrees from the normal state by the drum servo control signal S4. By this operation, data is written on tracks such as B1 and B2 by the A-channel recording head 1. <Step 4> Capstan servo control signal S
5, the tape 6 is run so as to be servo-locked in the same phase as in the normal state.

<Step 5> Servo lock is performed, and recording is started when the position of the tape where the failure of the B channel recording head 2 has occurred is reached. In this case, recording ON / OFF
Only the A-channel recording head 1 operates and the B-channel recording head 2 does not operate according to the control signals S1 and S2. <Step 6> When the recording of the abnormal recording portion due to the head failure is completed, the recording ON / OFF control signal S
1, the recording is stopped by S2, the settings of the drum 16, the capstan 17, and the switch R18 are returned to the normal settings, and the next operation is prepared.

By the above operation, the data of the area B23 in the recording data memory is written by the A-channel recording head 1 on the tracks such as B1 and B2 in FIG.
In other words, insert recording is performed every other track using the A-channel recording head 1.

The tracks such as B1 and B2 are written by the A-channel recording head 1 by inverting the phase of the drum 16 in step 3 and step 4 and keeping the tape phase unchanged. Instead of step 4, the following steps 11 and 1
By performing 2, the same can be realized by shifting the tape phase by one track while keeping the drum phase unchanged.

<Step 11> The drum 16 is rotated in the same phase as in the normal state. <Step 12> In accordance with the capstan servo control signal S5, the tape 6 is run so as to be servo-locked at a position shifted by one track from the normal state.

The operation in the case where a failure has occurred in the B-channel recording head 2 has been described above. The same operation is performed when the failure has occurred in the A-channel recording head 1. In this case, the switch R18 is switched to the position R2, and the data in the area A22 of the recording data memory is supplied to the B-channel recording head 2.

Next, the operation when a failure is detected in the reproducing head will be described in detail, taking as an example the case where clogging occurs in the B-channel reproducing head 5. In this case, the tracks B1, B2, etc. in FIG. 4 are tracks that should normally be reproduced by the B-channel reproducing head 5, but normal reproduction is not performed by the clog of the B-channel reproducing head 5. On the other hand, since the A-channel reproducing head 4 is normal, tracks such as A1 and A2 are normally reproduced.

If a failure of the B-channel reproducing head 5 is detected by the head failure detecting circuit 15 during reproduction, the information is sent to the control circuit 14 and the control circuit 1
4 operates as follows.

<Step 1> B-channel reproducing head 5
The tape 6 is pre-rolled (cueing) to the tape position where the failure has occurred. <Step 2> Reproduction data write control signal S
7 to switch P19 to position P1 (normal position)
To position P3. With this operation, data that should be read by the B-channel reproducing head 5 is read by the A-channel reproducing head 4 and written into the area B25 of the reproduction data memory.

<Step 3> The drum 16 is rotated at a phase shifted by 180 degrees from the normal state by the drum servo control signal S4. With this operation, tracks such as B1 and B2 are traced by the A-channel reproducing head 4, and data is read. <Step 4> Capstan servo control signal S
5, the tape 6 is run so as to be servo-locked in the same phase as in the normal state.

<Step 5> When the servo lock is performed and the tape position at which the failure of the B-channel reproducing head 5 has occurred is reached, the loading of the reproducing data into the reproducing data memory 21 is started. <Step 6> When the reproduction of the abnormal reproduction portion due to the head failure is completed, the reproduction is stopped, and the settings of the drum 16, the capstan 17, and the switch P19 are returned to the normal settings, and the system is ready for the next operation.

With the above operation, the reproduced data from the tracks B1, B2, etc. are read out by the A-channel reproducing head 4, and the data is written into the area B25 in the reproduced data memory. Area A in playback data memory
In 24, reproduction data from tracks such as A1 and A2 read out during normal reproduction remains as it is.

It should be noted that the tracks such as B1 and B2 are read out by the A-channel reproducing head 4 by inverting the phase of the drum 16 in step 3 and step 4 and keeping the tape phase unchanged. Similarly to the above, a method of shifting the tape phase by one track while keeping the drum phase as it is may be used.

The operation in the case where a failure has occurred in the B-channel reproduction head 5 has been described above. However, the same operation is performed when the failure has occurred in the A-channel reproduction head 4. In this case, the switch P19 is switched to the position P2, and the data read by the B-channel reproducing head 5 is written to the area A24 of the reproduction data memory.

In the above embodiment, an apparatus having two heads each for recording and reproduction has been described. However, it is only necessary to have another normal head when a failure occurs.
The same system can be used to expand the system beyond the head. Further, the apparatus may be provided with two or more heads for both recording and reproduction.

Although the memory and the switch in the signal processing circuit 7 are connected, the data to be recorded is stored in the memory outside the signal processing circuit 7 and the data is not held in the signal processing circuit 7. In this case, the signal processing unit corresponding to each head and the switch unit may be connected.

[0052]

According to the present invention, in a helical scan type tape recorder such as a data recorder, a video tape recorder, or a tape streamer, even if a failure occurs in a recording head or a reproducing head, normal operation can be performed by a retry operation. The normal recording or reproduction can be continued using the head.

Particularly, in the case of a tape streamer, by performing head switching during preparation processing for recording retry or reproduction retry, it becomes possible to operate as if there was no head failure. This simplifies the system for protecting unrecorded data on the buffer memory. In addition, flexibility is added to the timing of repair of the head system.

Furthermore, it is not necessary to additionally use a device such as a DT head for the purpose of recovery from a failure, and it can be realized with a simple configuration.

[Brief description of the drawings]

FIG. 1 is a diagram showing a head configuration according to an embodiment of the present invention.

FIG. 2 is a block diagram of an electric system according to the embodiment of the present invention.

FIG. 3 is a block diagram showing a detailed configuration of a memory peripheral portion for recording data and a memory peripheral portion for reproduction data in a signal processing circuit.

FIG. 4 is a diagram showing a track pattern of a normal helical truck.

FIG. 5 is a diagram showing a track pattern when a clog occurs in a B-channel recording head.

[Explanation of symbols]

1 A channel recording head, 2 B channel recording head, 3 scanner, 4 A channel reproducing head, 5
... B-channel reproducing head, 6 ... Tape, 7 ... Signal processing circuit, 8 ... Memory peripheral for recording data, 9 ... Memory peripheral for reproducing data, 10, 11 ... Recording amplifier, 12,
13: reproduction amplifier, 14: control circuit, 15: head failure detection circuit, 16: drum, 17: capstan, 18: switch R, 19: switch P, 20: memory for recording data, 21: memory for reproduction data, 22 area A of recording data memory, 23 area B of recording data memory, 24 area A of reproduction data memory
25: Area B of reproduction data memory, S1, S2: Recording ON / OFF control signal, S3: Error correction information, S4: Drum servo control signal, S5: Capstan servo control signal, S6: Recording data output destination control signal , S7... A reproduced data write control signal, A1, A2, A3, A4, A5, A6,
B1, B2, B3, B4, B5, B6 ... track, D1
... scanner rotation direction, D2 ... tape advance direction, D3 ... scan direction

Claims (6)

[Claims] At least two or more recording means for scanning in a diagonal direction with respect to a running direction of a magnetic tape to record a signal in an oblique recording area of the magnetic tape; An abnormality detection unit for detecting, a recording signal processing system for supplying a recording signal corresponding to the recording unit, a switching unit for switching a combination of connection between the recording signal processing system and the recording unit, and a detection by the abnormality detection unit. A magnetic recording apparatus comprising: a control unit that controls a combination of connections of the switching unit according to the abnormality and controls a rotation phase of a rotating body on which the recording unit is mounted and a phase of the magnetic tape. 2. The magnetic recording apparatus according to claim 1, wherein the recording signal processing system is a storage unit. 3. When recording is performed again on an oblique recording area of the magnetic tape that has not been normally recorded when the abnormality is detected by the abnormality detecting unit, the control unit may include: At least one of the phases of the magnetic tape is changed from the phase at the time of normal operation, and the recording means other than the recording means that has detected an abnormality and the recording signal processing system that supplies a signal that has not been recorded normally. 2. The magnetic recording apparatus according to claim 1, wherein connection of the switching unit is controlled so as to make connection. 4. At least two or more reproducing means for scanning obliquely with respect to the running direction of the magnetic tape to reproduce a signal in an oblique recording area of the magnetic tape; An abnormality detection unit for detecting, at least two or more reproduction signal processing systems supplied with signals from the reproduction unit, a switching unit for switching a combination of connections between the reproduction unit and the reproduction signal processing system, A magnetic reproduction apparatus comprising: a control unit that controls a combination of connections of the switching unit based on an abnormality detected by the unit and controls a rotation phase of a rotating body equipped with the reproduction unit and a phase of the magnetic tape. . 5. The magnetic reproducing apparatus according to claim 4, wherein the reproduction signal processing system is a storage unit. 6. In the case where reproduction is performed again on an oblique recording area of the magnetic tape that has not been normally reproduced when an abnormality is detected by the abnormality detection unit, the control unit may include: At least one of the phases of the magnetic tape is changed from the phase at the time of normal operation, and the reproduction signal processing system to which a signal that has not been normally reproduced is supplied to the reproduction means other than the reproduction means that has detected an abnormality. 5. The magnetic reproducing apparatus according to claim 4, wherein the connection of the switching unit is controlled so as to connect the magnetic reproducing apparatus.