JPH10112004A - Magnetic recording and reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the number of channels of the recording and the reproducing circuits of the device and to simplify the format process of the tracks including the blocks to be rewritten during the rewriting operation when a defective block is detected. SOLUTION: By arranging recording heads CH0(10) and CH1(11) and reproducing heads CH0(12) and CH1(13) in a respective opposing manner to each other in a 180 deg. direction on a drum, the four heads are successively used for a recording and/or reproducing and the recording and reproducing circuits are used by switching the heads CH0 and CH1. Moreover, the format process of a rewriting frame is made simple by only changing the frame number and the block number by conducting the rewriting operations in the RAM of the signal processing circuit that stores the frame unit in which plus and minus azimuth tracks written by the recording heads above are made as a pair.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for recording or reproducing information on a magnetic tape, and more particularly to an apparatus for recording or reproducing information on a magnetic tape obliquely to the tape.

[0002]

2. Description of the Related Art Conventionally, a track (helical track) oblique to the running direction of a magnetic tape as a recording medium.
In the magnetic recording / reproducing apparatus in which information is recorded or reproduced, the recording head CH0 and the recording head CH1, and the reproducing head CH0 and the reproducing head CH1 are arranged on the drum adjacent to each other, and the recording head CH0 and the reproducing head CH0 are , And the recording head CH1 and the reproducing head CH1
Are arranged 180 ° opposite each other, and approximately 1
An 80-degree magnetic tape was wound, and two recording heads or two reproducing heads were simultaneously recording or reproducing on two channels. However, the azimuths of the recording head and the reproducing head are different, the recording head CH0 and the reproducing head CH0 are positive azimuth heads, and the recording head CH1 and the reproducing head CH1 are negative azimuth heads.

In a magnetic recording / reproducing apparatus, a signal recorded by a magnetic head is continuously compared with a signal reproduced by another magnetic head, and a check is made to see if there is any defect. Techniques for rewriting are known.
Conventionally, rewriting is performed in units of blocks included in a helical track. For example, when a defective block is detected, the defective block is rewritten at a predetermined position.

[0004]

In the above prior art, the recording head CH0 and the recording head CH1 perform recording or reproduction simultaneously on two channels during recording and the reproduction head CH0 and the reproduction head CH1 simultaneously perform reproduction. Each circuit required a circuit for two channels.

In the prior art, when rewriting a signal, the rewriting is performed not in units of frames but in units of blocks. Therefore, temporary storage means (signals) for temporarily storing data sent from a host device. In the signal processing circuit, a track to be rewritten is inserted between data rows that have not yet been written to the tape, and track format processing is performed again in the signal processing circuit. It had to be fixed and the process was complicated.

[0006]

In order to solve the above-mentioned problems, two print heads CH0 and CH1 are replaced by two print heads CH0 and CH1.
One read head CH0 and one read head CH1
° The recording head CH0, the reproducing head CH1, the recording head C
H1 and the reproducing head CH0.

In order to solve the above problem, a rewrite operation is performed for each frame in which a positive azimuth track and a negative azimuth track are written by a recording head. Re-write the frame including the bad block, for the re-track format processing in the frame at that time to capture the frame in the signal processing circuit,
Only addresses such as frame numbers and block numbers indicating the physical order of frames and blocks are rewritten.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, according to an embodiment of the present invention, data sent from a higher-level device is recorded diagonally on a tape, or data recorded on a tape is reproduced and sent to a higher-level device 1. A description will be given using a helical scan magnetic recording / reproducing apparatus.

FIG. 1 shows a hardware configuration of the present apparatus. The present apparatus includes an interface unit 2 with the host device 1, a temporary storage unit 3 for temporarily storing data sent from the interface unit 2, a signal processing circuit for formatting or deformatting data (temporary for each frame unit). A built-in RAM for storage) 4, a non-volatile storage means 5 having a non-rewritable area, an interface means 2 and a signal processing circuit 4, and a system controller 6 for controlling the temporary storage means 3 and the non-volatile storage means 5; Recording circuit 7, reproduction circuit 8, rotary transformer 9, recording head C
A drum 14 (for example, having a diameter of approximately 40 mm) having a reproduction preamplifier 23 and the like connected to the H0 10 and the recording head CH11, the reproduction head CH12 and the reproduction head CH113, and a power supply for supplying power to the reproduction preamplifier 23 Supply means 15, motor / sensor 16 as a mechanism, recording circuit 7, and reproducing circuit 8
And a servo controller 17 for controlling the

The servo controller 17 comprises a servo section 19 for controlling the rotation of a plurality of motors, and a servo control section 18 for I / F between the servo section 19 and the system controller 6.

At the time of recording, the recording data from the host device 1 is stored in the temporary storage means 3 via the interface means 2 in a predetermined amount, and then transmitted to the signal processing circuit 4. After two or three types of error correction codes are added to the recording data by the signal processing circuit 4, a track format is generated,
After that, it is transmitted to the recording circuit 7.

FIG. 2 shows the configuration of the recording circuit 7. The recording data sent to the recording circuit 7 is switched between a signal for channel 0 and a signal for channel 1 by the channel switching means. However, the channel on the recording head CH0 10 and the reproducing head CH0 12 side is referred to as channel 0, and the channel on the recording head CH1 11 and the reproducing head CH1 13 side is referred to as channel 1. The switched signal is sent to the channel 0 side recording amplifier 26 or the channel 1 side recording amplifier 27 by the channel switching means 25 in accordance with the operation of the recording head. Then, after being transmitted to the rotary transformer 9, the recording head CH0 10
Or, it is sent to CH1 11.

Referring again to FIG. 1, at the time of reproduction, a reproduction signal is read out from the reproduction heads CH0 12 and CH1 13 and then amplified by the reproduction preamplifier 23, transmitted to the rotary transformer 9 and then put into the reproduction circuit 8. Sent.

FIG. 3 shows the configuration of the reproducing circuit 8. In the reproducing circuit 8, the signal reproduced by the reproducing head CH 0 12 is inputted to the channel 0 side amplifier 28, and the signal reproduced by the reproducing head CH 1 13 is inputted to the channel 1 side amplifier 29.
Then, a reproduction signal is sent from the amplifier selected by the channel switching means 30 to an AGC (auto gain control) 31. The channel switching means 30 is controlled by the servo controller 17. The signal input to the AGC 31 is sent to the equalizer 32 where the gain and the signal are adjusted to equalize the amplitude and the phase. The signal is then sent to the signal processing circuit 4 through the discrimination circuit 33.

Referring again to FIG. 1, the signal output from the reproducing circuit 8 is transmitted to the signal processing circuit 4, and after the formatted data is restored, the interface means 2
Is transmitted to the host device 1 via

A program of the system controller 6 is stored in the non-volatile storage means 5 and is rewritable. Also, the motor control parameters, the motor and the recording / reproducing circuit 8 set at the time of assembly adjustment are set.
Is also stored. The initial adjustment value measured for each device at the time of assembling the device is stored in the nonvolatile storage unit 5.
The adjustment value differs for each device.

However, since the nonvolatile storage means 5 has a non-rewritable area and the initial adjustment value is written in this area, even if the revision of the microprogram included in the system controller 6 is changed and another area is rewritten, Only the non-rewriting area storing the initial adjustment value is not rewritten. The servo parameters and the initial adjustment values are read by the system controller 6 when the power of the apparatus is turned on, and transmitted to the servo controller 17.

As shown in FIG. 1, in this apparatus, the magnetic tape 22 is pulled out by a guide roller 21, and is wound obliquely around the drum 14. Four magnetic heads are used, and the recording head CH0 (W
r CH0) 10 and recording head CH1 (Wr CH1)
A pair of a read head 11 and a pair of a read head CH0 (Rd CH0) 12 and a read head CH1 (Rd CH1) 13 are positioned to face the drum 14 by 180 °.
The drum 14 rotates at a higher speed than the tape 22 and contacts the tape 22 to perform recording or reproduction.

FIG. 4 shows the tracks recorded on the magnetic tape 22. At the time of recording, the track CH0 (TrCH) is recorded on the magnetic tape 22 using the recording head CH010.
0) 35 are sequentially recorded on the track CH1 (TrCH1) 36 by using the recording head CH11. The recorded tracks CH0 35 and CH1 36 are track pairs having different azimuths, and this track pair is called a frame. The track forming the frame includes a plurality of information blocks 37.

FIG. 5 shows the structure of an information block. The information block 37 is the user data 4 sent from the host device 1.
0 and CRC (Cyc) which is redundant data for error detection.
(Like Redundancy Check) 41 and two types of error correction codes C1 code 42 and C2 code 43.

FIG. 6 shows the recording / reproducing timing of a track. Due to the mounting position of the magnetic head, the track CH
0 35 and track CH1 36 are recorded, and
° With a delay, tracks CH0 35 and CH1
36 are reproduced. Also, depending on the length of the signals recorded on the tracks CH0 and CH1, the track CH0
1 or 36 is recorded or reproduced with a delay of Δt from the track CH0 35.

Further, since the recording head and the reproducing head are alternately mounted at 90 ° positions, the recording operation and the reproducing operation are performed simultaneously except for the initial operation. If performed simultaneously, the recording heads CH0 10 and CH1 1
1, the recording signal jumps into the rotary transformers 9 of the reproducing heads CH0 12 and CH1 13 in the rotary transformer 9;
It degrades the S / N of the reproduced signal. Noise is reduced in order to prevent deterioration of S / N. However, by mounting a reproduction preamplifier 23 in the drum 14, S is increased and a predetermined S / N is secured. The reproduction preamplifier 23 is supplied with DC power by the power supply means 15, the rotary transformer 9, and the smoothing means 20.

FIG. 7 shows a relationship between a recording frame and a reproduction frame in a read check after recording performed by the signal processing circuit 4. In the recording operation, after the data writing is completed, the signal processing circuit 4 reproduces the written data, performs a read check at any time to check whether or not the recorded data has been normally written, and outputs the result to the system controller 6. Report to However, the reading check is performed on a frame basis. When an error of the information block 37 in the frame is detected, the frame including the bad block in which the error is detected is detected as an error frame.

In FIG. 7, when the reproduction signal of the frame N is completely transmitted to the signal processing circuit 4, the frame N + 1 has already been output.
CH1 signal is starting to be written. When the reading check is completed in the signal processing circuit 4 and the system controller 6, the N + 2 signal is already ready for writing. Therefore, the defect is detected by the reading check,
The position where the data of frame N is written again is frame N + 2
After. At this time, the frame N after the frame N + 2
Then, instead of writing the frame N + 3, the information is written in the order of frame N + 1, frame N + 2, frame N + 3 by giving priority to the writing order of the information.

FIG. 8 is a flowchart of the recording recovery operation. During recording, after recording the frame N (60), the frame N + 1 is subsequently recorded (61). Frame N + 1
Is recorded while the signal processing circuit 4
Thus, a reading check of the frame N is performed (62). When the signal processing circuit 4 detects an error in the reading check (63), the frame N which is already ready for writing without stopping the tape 22 is stopped.
+2 is recorded (64), and after frame N + 2 is recorded, N + 1 is rewritten (65).

Rewriting is performed on a frame basis as described above, and is recorded at a frame position after a predetermined number (two frames in this embodiment) from the error occurrence frame. At the time of rewriting, the error frame is temporarily stored by the signal processing circuit 4 in a memory built in the signal processing circuit, and the frame number and the physical block number are rewritten to re-format the track.

Then, after the frame N, the frame N + 1
Is rewritten (66), and when a reading check of frame N is performed while recording frame N + 1 (67),
If an error is detected again without a successful read check, frame N + 2 is rewritten (69).
Thereafter, the operations from 65 to 69 are repeated up to 15 times (70). If an error is detected without success of the read check even after repeating the rewriting 15 times, a recording error is reported to the host device 1 (71). In all cases where no error is detected in the reading check of this recording recovery operation, the recording recovery operation is terminated, and if there is data to be recorded next, recording of the next data (frame N + 3) is continued.

[0028]

According to the present invention, since two recording heads and two reproducing heads are arranged on the drum so as to face each other by 180 °, at the time of recording, after writing with the recording head CH0, after 180 ° Writing is performed by the recording head CH1, and at the time of reproduction, after reproduction is performed by the reproduction head CH0, reproduction is performed by the reproduction head CH1 after 180 °. Therefore, since recording and reproduction are not performed simultaneously on two channels, one recording circuit and reproduction circuit can be switched and used, and there is an effect that the circuit scale is reduced to half of the conventional circuit.

Further, according to the present invention, in order to perform rewriting in units of frames, R is stored in units of frames without using temporary storage means in the preceding stage of the signal processing circuit.
The re-track format processing can be performed only by the signal processing circuit having the built-in AM, and the simple processing of simply changing the frame number, the block number, and the like is performed, and the re-track format processing is simplified.

[Brief description of the drawings]

FIG. 1 is a hardware configuration diagram of a helical scan magnetic recording / reproducing apparatus.

FIG. 2 is a configuration diagram of a recording circuit 7;

FIG. 3 is a configuration diagram of a reproduction circuit 8;

FIG. 4 is a diagram of a track recorded on a magnetic tape.

FIG. 5 is a diagram showing information blocks in a track of a frame.

FIG. 6 is a diagram showing recording / reproducing timing of a track.

FIG. 7 is a diagram illustrating an order relationship between recording and reproduction of a recording frame and a reproduction frame in a reading check;

FIG. 8 is a flowchart of a recording recovery operation.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 High-order apparatus 2 Interface means 3 Temporary storage means 4 Signal processing circuit 5 Non-volatile storage means 6 System controller 7 Recording circuit 8 Reproduction circuit 9 Rotary transformer 10 Recording head CH0 11 Recording head CH1 12 Reproduction head CH0 13 Reproduction head CH1 14 Drum 15 Power supply Supply unit 16 Motor / sensor 17 Servo controller 18 Servo control unit 19 Servo unit 20 Power supply smoothing unit 21 Guide roller 22 Magnetic tape 23 Reproduction preamplifier 25 Recording circuit channel switching unit 30 Reproduction circuit channel switching unit 32 Equalizer 33 Discrimination circuit 35 Track CH0 36 Track CH1 37 Information block 40 User data 41 CRC 42 C1 code 43 C2 code

Claims (5)

[Claims] 1. A recording magnetic head for recording information on a magnetic tape, a reproducing head for reproducing the information, an amplifying means for amplifying an output of the reproducing head, and the recording head and the reproducing head. With the rotating drum mounted,
Magnetic tape transport means for reciprocating the magnetic tape, temporary storage means for temporarily storing information transmitted to and received from a higher-level device, and information from the higher-level device being converted into information for recording on the magnetic tape, and A signal processing circuit that converts information into information that can be transmitted to a higher-level device, and detects whether information has been normally recorded from information reproduced from a magnetic tape and information to be recorded,
A controller that controls the signal processing circuit, the temporary storage unit, the magnetic tape transport unit, and the rotating drum;
A recording circuit that converts information transmitted from the signal processing unit into a signal recordable on a magnetic tape, and a reproduction circuit that converts a signal transmitted from the reproduction head into a signal that can be processed by the signal processing circuit. Wherein the recording head and the reproducing head each have a head of 2
And the two recording heads or the two reproducing heads are disposed on the drum so as to be substantially 180 degrees opposite to each other, and each of the two recording heads or the two reproducing heads A signal is transmitted or received to the head for only about half of the drum rotation period, and the reproducing head output amplifying means is internally mounted on a rotating drum equipped with a recording head and a reproducing head. Magnetic recording and reproducing apparatus. 2. The magnetic recording and reproducing apparatus according to claim 1, wherein the two recording heads or the two reproducing heads have different azimuths, and each of the recording heads has a positive azimuth recorded on a magnetic tape. A frame is composed of a pair of tracks of negative azimuth, and the signal processing circuit detects whether or not information has been normally recorded for each frame, and the controller again performs the information processing for each frame based on the detection output. A magnetic recording / reproducing apparatus for performing rewriting control. 3. The magnetic recording / reproducing apparatus according to claim 2, wherein the track includes a plurality of information blocks, and the information blocks include information sent from a host device and converted by the signal processing circuit. And a plurality of information error detection signals and an information error detection signal unique to the information of the block. 4. The magnetic recording / reproducing apparatus according to claim 2, wherein a frame number of a recorded frame is N, and a frame number of a reproduced frame for which detection of whether or not recording has been normally completed is M. Then the controller is in frame M
Frame M and frame M
And a frame from N to N. 5. The magnetic recording / reproducing apparatus according to claim 2, wherein at the time of rewriting for each frame including a plurality of information blocks, the frame is taken into storage means in the signal processing circuit, and the frame and the block are read. A magnetic recording / reproducing apparatus, which rewrites the addresses of the frame number and the block number indicating the physical order of the above, and performs the re-track format processing in the frame.