JPH01189089A - Magnetic recorder - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic recording device, and more specifically to a magnetic recording device in which signals are recorded in a plurality of tracks at once using a plurality of magnetic heads.

[Conventional technology]

A magnetic recording device is provided with a monitor head that monitors the recording operation of the recording head. Conventionally, as shown in FIG. It was placed behind each recording/reproducing magnetic head in the direction of the recording/reproducing magnetic head. In FIG. 9, 10 is a magnetic tape, 12.degree. 14 is a recording/reproducing magnetic head, 16 is a rotating drum, and 18.20 is a monitor head.

[Problem to be solved by the invention]

However, in the conventional example, the monitor head 18.20 is arranged corresponding to each recording/reproducing head 12.14, so, for example, as in a digital VTR, one field's worth of video signals can be recorded in multiple recordings. Multiple troughs with head
In the case of a recording method in which recording is performed at once, it is necessary to arrange as many monitor heads as there are recordings. Mounting a large number of recording heads onto a drum with limited space is itself a difficult task;
Positioning the head adds to the difficulty of the task.

The present invention aims to provide a magnetic recording device that requires fewer monitor heads.

[Means to solve the problem]

A magnetic recording device according to the present invention includes a rotating drum on which a magnetic tape is wound over a predetermined winding angle during recording and equipped with a plurality of magnetic heads, and a predetermined unit amount of video signal to be recorded is transmitted by the plurality of magnetic heads. A magnetic recording device that simultaneously records on multiple tracks, in which the rotating drum is equipped with a monitor head that monitors the recording operation of the recording head, and the monitor head is moved in a direction that intersects the recording track pattern of the magnetic tape. It is characterized in that it is provided with a moving means that can be moved freely, and that the number of monitor heads is smaller than the number of recording tracks for simultaneous recording.

[Effect]

The moving means allows one monitor head to monitor the recording states of a plurality of recording heads. Therefore, it is not necessary to arrange a monitor head for each recording head, and the number of monitor heads can be reduced.

〔Example〕

Hereinafter, the present invention will be described in detail with reference to the M plane.

FIG. 1 is a plan view of a rotating drum in an embodiment of the present invention. In FIG. 1, 22 is a magnetic tape, 24 is a magnetic head for recording and reproducing, and 26 is a magnetic tape 22 used for recording or reproducing.
27 is a rotating drum wrapped at a predetermined angle, and 27 is a double drum.
Azimuth monitor head (playback only head), 28
is a bimorph that moves the monitor head 27 in the recording track pattern width direction in accordance with a control voltage.

FIG. 5 shows a basic configuration block diagram of a digital VTR. In FIG. 5, the video signal from the camera 30 is
A converter 32 digitizes the output, a time compression circuit 34 compresses the time, and an ECC encoding circuit encodes and adds an error correction code to the output of the time compression circuit 34, and a shuffling circuit 38 performs shuffling. The data recording circuit 40 applies the output signal of the shuffling circuit 38 to a plurality of recording/reproducing magnetic fields 24 for one field, and causes the signal to be recorded on a plurality of tracks of the magnetic tape 22.

The track pattern is shown in Figure 2.

At the time of reproduction, a plurality of trunk patterns are simultaneously traced to a plurality of recording/reproducing magnets by the 7D 24 and reproduced by the data reproduction circuit 42. The output of the data reproducing circuit 42 is stored in the frame memory 44, the ECC decoding circuit 46 performs decoding and error correction using ECC, the time axis expansion circuit 48 expands the time axis, and the D/A converter 50 It is converted into an analog signal and displayed as an image on the display device 52.

In addition, in FIG. 5, 54 is a DTP controller, and 56- is a control for the bimorph 28? a high voltage amplifier that forms fax pressure;
58 is a PLL circuit, 60 is a mono multi-by-break, 6
2 is a gate circuit that gates the output of the monitor head 28 under the control of the output pulse of the mono-multivibrator 60; 64 is a determination circuit that determines the recording state of the recording head, that is, whether there is an abnormality; and 66 is a microcomputer. .

In such a magnetic recording/reproducing apparatus, during recording, a microcomputer-controlled control voltage is applied to the bimorph 28 to move the monitor head 27 in a direction that crosses the tracks, and for each rotation of the drum 26, the second As shown in the figure, for the recording trunk pattern, pattern F
From there, trace diagonally toward pattern A.

In addition, FIG. 2 (1) shows the first rotation of the drum 26, FIG. 2 (2) shows the second rotation, and FIG. 2 (3) shows the third rotation.
correspond to heads A to F of the recording/reproducing magnetic head 24, respectively. Also, during this tracing, the rise start times of the bimorph control voltages are staggered, as shown in FIG. 3, so that the locus of the monitor head 27 does not follow only the same location on the track pattern. . This allows the entire track to be detected.

Specifically, in this embodiment, the rise of the bimorph control voltage is started at a drum wrapping angle of 0'' and 60°.

By setting the timing to 120 degrees, the trunk pattern is divided into three parts as shown in FIG. and,
The monitor head 27 is successively traced diagonally with respect to the recording track pattern, and after the bimorph control voltage starts rising at the timing of the drum wrap angle 120', the above operation is repeated again. At this time, the output of the monitor head 27 is shaped like an abacus bead with a peak value for each recording track pattern, as shown in FIG. 4A. Recording track patterns F, E, D, C, B.

Line up in order of A.

In order to clarify the correspondence between the output of the monitor head 27 and each recording track pattern, a gate circuit 62 is provided that allows the output of the monitor head 27 to pass for a specific period of time in synchronization with the rise of the bimorph control voltage. It is a provision. The output of the gate circuit 62 is a rectangular wave with peaks corresponding to recording track patterns A-F, as shown in FIG. 4B. The determination circuit 64 determines, based on the output of the gate circuit 62, whether the recording/reproducing heads A to F are operating normally during recording. microcomputer 6
6 performs position control of the bimorph 28 and other calculations according to the determination result of the determination circuit 64.

FIG. 6 shows a drum configuration of another embodiment of the present invention. 1st
Components that are the same as those in the figure are given the same reference numerals. , 70 is a magnetic tape, 72 is a rotating drum, 74 is a recording/reproducing magnetic head, 76 and 78 are a set of read-only magnetic heads (monitor heads) with different azimuths, and 80 is a bimorph. Even with this drum configuration, one field of video signals is simultaneously recorded on multiple tracks on the magnetic tape 70 using multiple A-C or DF recording and reproducing magnetic heads, but during recording, the control voltage is applied to the bimorph 80. This application causes the monitor heads 76, 78 to trace the recording track pattern diagonally as shown in FIG. 7 for each revolution of the drum 74. That is, the monitor head 76 moves from the recording track pattern E toward the recording track pattern A, and during this movement, signals are taken out from the recording track pattern by the recording/reproducing heads F, D, and B having the same azimuth as the head 76. . Also, monitor head 78
move toward the recording trunk pattern C, and during that movement pick up signals from the recording track pattern by the recording and reproducing rads C, A, and E in the same azimuth as the head 78. The outputs of the monitor heads 76, 78 and of the gate circuit which passes the outputs in the center of the track pattern are shown in FIG. A determination circuit similar to the determination circuit 64 determines whether the recording/reproducing magnetic heads A to F are operating normally.

This second embodiment also uses a read-only magnetic head (monitor/
The trajectory of the heads) 76 and 78 may be shifted not only once, but also on the recording track pattern as in the first embodiment.

In the above embodiment, a bimorph was used as an example of a means for moving the monitor head in the recording track crossing direction, but of course, other moving means and moving mechanisms can be employed.

〔Effect of the invention〕

As can be easily understood from the above description, according to the present invention, each recording head can be operated without assigning a monitor head to each recording head and making them work together, that is, by using fewer monitor heads. Operation status can be monitored. This allows the number of heads to be attached to the drum to be reduced, thereby making it possible to downsize the rotating drum and reduce the cost of the device.

[Brief explanation of the drawing]

FIG. 1 is a plan view of the rotating drum according to the first embodiment of the present invention, FIG. 2 is an explanatory diagram of the trace locus of the monitor head, and FIG.
The figure is a timing diagram of the control voltage of the mechanism that moves the monitor head in the cross-track direction, Figure 4A is the output diagram of the monitor head, and Figure 4B is a waveform diagram of the monitor head output gated at the center of each recording track. , FIG. 5 is a block diagram of the configuration of the recording/reproducing circuit system of the first embodiment, FIG. 6 is a plan view of the rotating drum of the second embodiment of the present invention, and FIG. 7 is an explanatory diagram of the trace locus of the monitor head. , FIG. 8 is a timing diagram of the output of the monitor head and a signal obtained by gated output at each center of a recording track, and FIG. 9 is a plan view of a conventional rotating drum. 22.70--Magnetic tape 24.72--Magnetic head for recording and reproduction 26.74-Rotating drum 27°76
．． 78--Monitor head 28.80--Bimorph

Claims (1)

[Claims] Equipped with a rotating drum equipped with a plurality of magnetic heads, on which magnetic tape is wound at a predetermined winding angle during recording,
A magnetic recording device that simultaneously records a predetermined amount of video signals to be recorded onto multiple tracks using multiple magnetic heads, the rotary drum is equipped with a monitor head that monitors the recording operation of the recording heads, and the magnetic tape is A magnetic recording device characterized in that the monitor head is provided with a moving means capable of freely moving the monitor head in a direction that intersects the recording track pattern of the magnetic recording device, and the number of the monitor heads is smaller than the number of recording tracks for simultaneous recording. .