JP2924391B2 - Magnetic recording / reproducing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic recording / reproducing apparatus for adjusting compatibility using a magnetic tape.

[0002]

2. Description of the Related Art In recent years, a recording / reproducing apparatus using magnetic recording has been widely used for a VTR or the like. , High-speed rotation, short-wavelength recording, narrowing of track, and thinning of magnetic tape are progressing. Under such circumstances, as a mechanical problem, good head touch is required for a magnetic head to correctly trace a recorded track and to efficiently extract a short-wavelength recording signal.

Conventionally, the format of this type of digital device has a configuration in which two channels are divided and recorded as shown in a schematic pattern diagram of FIG. In FIG. 4, 1 is a magnetic tape, 2 is a control track, 3 is a time code track, 15 and 16 are first paired tracks A, B, 17 and 18 which are different from each other in the azimuth direction. Pair tracks A, B and 8 are cue tracks.

Conventionally, in the analog system, overlap recording is performed in consideration of the fluctuation width of the timing of head switching. However, in the case of the digital system, signals other than necessary signals are recorded since a signal can be obtained. Normally, there is no need for overlap recording. Furthermore,
In order to increase the recording density, the helical track is recorded up to a position close to the time code track 2 or the cue track 8. When recording is performed with magnetic heads facing 180 degrees, the recording track length is determined to be about 178 degrees in accordance with head switching with a 50:50 duty at equal timing. This track is only as long as the track length necessary to record all the signals. Further, the pair head for recording the track shown in FIG. 4 is normally set to be shifted in the rotating direction (not shown). for that reason,
Tracks 15 and 17 and Track 1 with different azimuth directions
6 and 18 have the same timing on the track pattern, but there is a time lag in the head output. FIG. 5 is a schematic diagram showing the relationship between the switching and the envelope.
In FIG. 5, 9 is a head switching high of track 15, 10 is a head switching low of track 17,
9 'is the head switching high of track 16 and 10'
Is the head switching row of the track 18, 19 is the envelope of the track 15, 20 is the envelope of the track 17, 21 is the gap between the envelopes 20 and 19, 22 is the gap between the envelopes 19 and 20, 19 ' Is the envelope of track 16, 20 'is the envelope of track 18, 2
1 'is a gap between the envelope 20' and the envelope 19 ', and 22' is a gap between the envelope 19 'and the envelope 20'.

In FIG. 5, each of the envelopes has only the required length, and further has a vacant space.
I do not know the track trajectory of the running section of the truck.

Furthermore, in the case of performing measurement using the azimuth time difference using the outputs of the envelopes of the tracks 15 and 17 simultaneously, as shown in FIG. 5, the synchronization signals of the video signals obtained from the envelopes are compared. However, no signal is obtained in the open part, and furthermore,
The comparison cannot be made for the time of the pair of magnetic heads that are displaced in the rotation direction.

[0007]

However, in the above-mentioned conventional configuration, when the track linearity is adjusted by using the envelope, it becomes unclear at the rising and falling positions, and furthermore, before entering the main track. In the track linearity measurement method using the azimuth time difference in which the track trajectory is not known at all or the signal of two channels is used at the same time, the portion where the signal does not overlap on the time axis between the paired heads in both the open space and the recording track length Occurs, and therefore, a required signal cannot be obtained. SUMMARY OF THE INVENTION It is an object of the present invention to provide a magnetic recording / reproducing apparatus capable of obtaining a signal required for adjustment with a track length longer than a track recorded on a format.

[0008]

In order to achieve the above object, a magnetic recording / reproducing apparatus according to the present invention usually employs a magnetic tape.
The linear track in the running direction and the linear track
Pair helical recording tracks in non-overlapping areas
The duty ratio is 50:50 and the duty is
Two first reproducing heads whose imaging is slightly shifted
Switching the pair head signal with the switching signal
When the compatibility is detected, the linear track is
The helical recording track of the pair is extended to the overlapping area.
Overlap recording and duty ratio of unequal length and longer
Of the two first read head switches
Is longer than the length including the same state as the
The two first forces being within a range in which the force is continuous.
The pair head signal is reproduced by the reproduction head switching signal of No. 2.
It is characterized by switching.

[0009]

According to the present invention, each head traces a track length recorded longer than a required length from the format, and a signal of a track longer than the track length is determined by the longer unequal length head switching. The helical recording track that can be played on the format required
Mechanical compatibility of helical trucks with a longer range than long
As well as continuous head output
Obtainable.

[0010]

An embodiment of the present invention will be described with reference to the drawings. FIG.
FIG. 2 is a schematic view showing a recording pattern of the present invention. 1 is a magnetic tape, 2 is a control track, 3 is a time code track, 4 and 5 are reverse azimuth helical recording tracks of the same pair, and 6 and 7 are reverse of the same pair 180 degrees out of phase with the recording tracks 4 and 5. Azimuth helical recording track, 8 is a cue track.

In FIG. 1, helical recording tracks 4,
Nos. 5, 6, and 7 are written in solid without switching at the time of recording, and all of the mechanical overlap of the magnetic tape on the drum is recorded. For this purpose, recording tracks 4, 5, 6, and 7 are also superimposed on the control track 2 and the cue track 8. The control tracks are necessary for the recorded magnetic tape 1 to run properly, and the helical recording tracks 4, 5, 6, and 7 for recording track video signals are high-frequency signals. The control signal is recorded as a pulse-like low-frequency signal in a deep portion of the magnetic layer, so that superposition recording is possible.

FIG. 2 is a diagram showing the relationship between the head switching signal and the envelope according to the present invention. 23 is a head switching signal corresponding to the helical recording tracks 4 and 6, 24 is a head switching signal whose duty is changed based on the head switching signal 23, 13 is the envelope of the helical recording track 4, and 14 is the envelope of the helical recording track 6. , 25 are head switching signals corresponding to the helical recording tracks 5 and 7, 26 is a head switching signal whose duty is changed based on the head switching signal 24, 13 'is the envelope of the helical recording track 5, and 14' is the helical recording track 7 is an envelope. Head switching signal 2
3, 25 have a duty of 50:50 and
Timing is shifted from each other by the
You. That is, from the head switching signals 23 and 25,
The generated head switching signals 24 and 26 are
In the example, the high is long and the low is short.

One of the paired helical recording tracks 4, 5 or 6, 7 is set as a long head switching signal or a short head switching signal so that signals can be continuously taken out. In FIG. 2, helical recording tracks 4 and 5 are long head switching signals, and helical recording tracks 6 and 7 are short head switching signals. Helical recording tracks 4 and 5 have long duty
High head switching is given,
Over almost the entire length of the written helical recording tracks 4 and 5
Can be played back and
Cover more than the required helical recording track length
To detect the envelope and the azimuth time difference
Detecting mechanical compatibility by arity detection method
Can be.

FIG. 3 is a block diagram for obtaining the head switching signal of FIG. Reference duty 5
This is for obtaining a signal with an unequal duty ratio from a reference signal of 0:50. The monostable multivibrator 1 keeps high for a predetermined time from the rise of the reference signal. The monostable multivibrator 2 goes high a predetermined time after the fall of the reference signal, and when these signals are added, a signal having a predetermined duty ratio is obtained.

Although the high time ratio is increased in this embodiment, the same effect can be obtained even if the low time is extended by the inverting circuit.

[0016]

As described above, according to the present invention, the helical recording track and the linear recording track are partially superimposed and recorded, and the timing of the head switching signal is made unequal in a range where the envelope is continuous.
A track showing mechanical compatibility over the entire track length required for the format of the digital signal.
The linear effect can be detected, and its practical effect is very large.
No.

[Brief description of the drawings]

FIG. 1 is a schematic pattern diagram of a magnetic tape used for adjusting a magnetic recording / reproducing apparatus according to an embodiment of the present invention.

FIG. 2 is a waveform chart showing a relationship between head switching and envelope output in the embodiment.

FIG. 3 is a block diagram showing a circuit example of a head switching circuit in the embodiment.

FIG. 4 is a schematic recording track pattern diagram of a conventional magnetic recording / reproducing apparatus.

FIG. 5 is a waveform chart showing a relationship between a conventional head switching and an envelope.

[Explanation of symbols]

 1 magnetic tape 2 control track 3 time code track 4,5,6,7 helical recording track 8 cue track

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int.Cl. ⁶ , DB name) G11B 5/00 G11B 5/008 G11B 20/12

Claims (1)

(57) [Claims] 1. A linear track in a running direction on a magnetic tape.
And the linear track in an area that does not overlap
Helical recording tracks continuously, and
The tee ratio is 50:50 and the timing is slightly shifted
Pair head with two first read head switching signals
A magnetic recording / reproducing device for switching signals of
When the compatibility is detected, the linear track is
The helical recording track of the pair to the overlapping area
Overlap recording and duty ratio of unequal length and longer
Of the two first read head switches
Is longer than the length including the same state as the
The two first forces being within a range in which the force is continuous.
The pair head signal is reproduced by the reproduction head switching signal of No. 2.
A magnetic recording / reproducing apparatus characterized by switching.