JPS58139318A - Magnetic storage device - Google Patents

Abstract

PURPOSE:To detect defective recording quickly, by providing a reproducing head on the same track near a pair of recording heads of a helical scanning type magnetic tape device and comparing a recorded signal stored in a storage section with a reproduction signal. CONSTITUTION:The recording heads 5, 7 and reproducing heads 6, 8 in contact on the same track near the heads 5, 7 are provided in the interval of 180 deg. on a helical cylinder. A signal from a bus line 11 is interfaced 12 and stored in an RAM17, an encoded 13 recording signal is amplified 14 and recorded on a magnetic tape with the head 5 or 7. The head 6 or 8 reproduces a signal just recorded with a small delay and amplifies 15 and decodes 16 it to a coincidence detection circuit 18. The circuit 18 compares the data of the RAM17 with the data of the decoder 16 for one track's share and an effective signal X is outputted when they are coincident. In case of dissidence, an ineffective signal Y is outputted and recorded again with the data in the RAM17. Thus, the recording with high reliability is executed easily.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method and apparatus for improving reliability when recording digital signals on a helical scan magnetic tape device.

Helical scan type magnetic tape devices can achieve higher recording density than fixed head type magnetic tape devices, so they are widely used in fields that require large amounts of information, such as VTRs.
It is used.

In addition, with the recent development of VTR technology, home-use V'R
A is produced in large quantities at low cost and is about to become extremely popular. Therefore, by utilizing home VTR technology, a large capacity and inexpensive magnetic storage device can be realized.

However, in the helical medium Yang type (1), the recording track is determined by the relative position of the rotating head attached to the cylinder and the magnetic tape running around the cylinder. Therefore, unlike magnetic disk devices, it has a major drawback in that random access is not possible.

Data reliability is a very important factor for a combination storage device. Therefore, when recording data in a magnetic disk device such as a flexible disk, the data to be recorded is first recorded on the magnetic disk.
Next, the data is played back to confirm whether it has been recorded correctly, and if an error occurs, the data is recorded again. However, in a helical scan type VTR, the first
As shown in the figure, since the magnetic tape runs at a constant speed, the magnetic head automatically moves to the next track, making it impossible to reproduce and confirm the recorded data. Stopping the running of the magnetic tape. Because the recording track is determined by the relative position of the rotating magnetic tape and the running magnetic tape, the magnetic head may become deviated from the track and the signal may not be reproduced correctly. Can not. Therefore, in order to reproduce and confirm the data once recorded, it is necessary to rewind the magnetic tape and run the tape again to reproduce the data. Generally, a very large amount of time is required to rewind the tape and resume running, making this type of data confirmation impractical.

As a device using a home VTR, there is a PCM recorder that converts a music signal into a digital value and records it on a VT)l. A PCM recorder is exactly the same as a magnetic tape device in that it records and reproduces digital values. PCM recorders use error correction codes to improve data reliability. However, error correction codes can correct mild errors, but cannot correct severe errors. In the case of audio signals, even if a severe error occurs once every 30 minutes, it cannot be said to be a fatal error, so an error correction code alone is sufficient, and even if the recorded data is checked. is not necessary.

When used as an external storage device for computers, personal computers, etc., it is essential to check the recorded data, as even the smallest error can be fatal.

SUMMARY OF THE INVENTION An object of the present invention is to provide a highly reliable magnetic tape device that eliminates the drawbacks of the helical scan type magnetic tape device described above and allows recorded data to be immediately reproduced and verified.

The feature of the present invention is to change the shape of the magnetic head attached to the cylinder so that recorded data can be immediately reproduced, and also to determine whether or not the reproduced data is correct. is recorded on the same magnetic tape, and the same data is recorded again on the next track until it is reproduced correctly.

2 and 3 show a recording format and a block diagram of an embodiment of the present invention, and the following description will be given with reference to the drawings.

Data recording is performed by first and second recording heads 5.7, and data reproduction is performed by first and second reproducing heads 6.8. The first and second recording heads 5.7 are mounted diagonally on the cylinder (not shown), and the first and second playback heads 6.8 are also mounted diagonally on the cylinder. There is. The two recording heads 5.7 scan the recording track alternately, and the two reproducing heads 6.
．． 8 also scans the tracks alternately.

When recording data, the data sent from the pass line 11 is passed through the interface circuit 12 to the RA.
The recording signal is sent to M 17 and yet-code circuit 11, and converted by encoder circuit 13, and recorded on a magnetic tape by recording amplifier 14 and recording head 5 (or 7). At this time, the reproducing head 6 (or 8), which scans the same track with a slight delay, reproduces the just recorded signal, which is converted into reproduced data by the reproducing amplifier 15 and decoding circuit 16. - The integrated product output circuit 18 is a RAM 17
The recorded data stored in the decoding circuit and the reproduced signal output from the decoding circuit are compared for all one track. When the recorded data and reproduced data all match, the data valid signal
The data is recorded at the beginning of the next track, and the data to be recorded next is requested from the CPU side (not shown) and recorded. If the recorded data and reproduced data do not match, a data invalid signal Y is recorded and the recorded data stored in the RAM 17 is recorded again. Therefore, information is recorded on the tracks on the magnetic tape as shown in FIG.

Data 41a is recorded on track 1, and when correctly reproduced by the reproducing head, a data valid signal X is recorded at the beginning of track 2. Next data b is subsequently recorded on track 2.

However, on track 3, data C was recorded.
Due to some reason, such as a scratch on the magnetic tape, the reproduced signal was C'. Therefore, data invalid signal Y is recorded at the beginning of track 4, and data C is recorded on track 4 again.

When reproducing data, the reproducing head 6.8 is used to reproduce the data. In this case, if there is a data invalid signal Y, the previous signal of that track is discarded.

That is, when track 4 is reproduced and data invalid signal Y is reproduced, data C' reproduced in track 3 is discarded and data C in track 4 is used.

In the embodiment shown in FIG. 3, the data valid signal It is also possible to record at the end of the track using the reproducing head 6 or 8. The tracks on the magnetic tape in this case are as shown in FIG.

1j in Figure 3! In this example, the recording head and playback head are
Although two heads are used for each, the same effect can be achieved by using two heads placed diagonally on the cylinder. In this case, it is necessary to shift the installation of one head compared to the other head so that the two heads scan the same track.

As described above, according to the present invention, it is possible to confirm that data has been correctly recorded on the magnetic tape, data is not lost due to scratches on the magnetic tape, and high reliability is achieved. can get. Also, every action is
Since this is done without interfering with tape running, data can be recorded or played back at high speed, and is particularly suitable for transferring large-capacity files at high speed. The processing required when reproducing data can be easily performed by simply determining whether the data is normal or not, and if it is not normal, using the data of the next track.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an example of a recording format of a helical scan VTR, FIG. 2 is a block diagram showing a recording method according to the present invention, and FIG. 3 is a block diagram showing an embodiment of a recording/reproducing thread according to the present invention. 4 is a block diagram showing a recording track according to the present invention, and FIG. 5 is a block diagram showing a recording track according to another embodiment of the present invention. 1...Magnetic tape 2...Video track 3.
...Audio track 4...Control track 5
...First recording head 6...Second recording head 7...First playback head 8...Second playback head 11...Has line 12...Interface circuit 15...・Encoding circuit 14...recording amplifier 15...reproduction amplifier 16・
...Decoding circuit 17...key " 1B...-Scattered product output circuit agent patent attorney Usui 1) Toshiyuki: 'Now. , 'L',! 71 En 41 O 2 Closed fan 3I!0 Fang 4 Figure 1 Tee 7° Length J direction 1 = 5 l Boob width J direction 1 season

Claims (1)

[Claims] 1 In a helical stream magnetic tape device that records digital signals, a first magnetic head that records digital signals, a second magnetic head that mainly reproduces digital signals, and a register that stores data to be recorded. It is equipped with an encoding circuit that converts the data to be recorded into a recording waveform, a decoding circuit that reproduces the recorded data from the reproduced waveform, and a coincidence detection circuit that detects whether the two data are abnormal. When recording, the encode circuit converts the data to be recorded into a recording waveform, and the first magnetic head records the data on the magnetic tape, and the second magnetic head converts the data recorded by the first magnetic head into a recording waveform. , the decoding circuit converts the reproduced signal into data, and the coincidence detection circuit
Determining whether the reproduced data matches the stored data stored in the register, and recording the result on a recording track by the first straddling second magnetic head; A magnetic storage device characterized by recording the same signal again on the next track if the signal does not match.