JPS60185211A - Magnetic recording and reproducing method - Google Patents

Abstract

PURPOSE:To record and reproduce many kinds of video signals simultaneously and efficiently by additionally inserting another magnetized locus into a guard band generated by increasing a tape travelling speed in parallel so that the guard band is left. CONSTITUTION:Since magnetic heads A1, B1 having head width wider than the width of a track to be reproduced are used, close recording between adjacent tracks due to superposed recording is performed. Since a reproduced output is not changed even if tracking is shifted within the difference between the head width and track width, an objective channel can be easily selected and reproduced. To reproduce video signals on an adjacent track and the track next to said adjacent track, its channel can be selected by shifting the relative positions between the magnetized locus and the magnetic head by one/two tracks.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a rotary head type magnetic recording and reproducing device that sequentially records and reproduces signals as a recording trajectory inclined at a predetermined angle with respect to the longitudinal direction of a magnetic tape using a rotary head. Below rVT
This article relates to a magnetic recording and reproducing method using RJ).

The structure of the conventional example and its problems The conventional magnetic recording and reproducing method will be explained using FIGS. 1 and 2.

FIG. 1 is a perspective view showing the main parts of a conventional two-head VTR. On the surface 1a of a rotating disk 1, there is a head mounting bracket having a head mounting surface forming an angle α with respect to the rotation axis (A). 2' is arranged, and magnetic heads A1 and B1 are placed on this surface.
are mounted at approximately symmetrical positions with respect to the rotation axis (a).

FIG. 2 shows the head AI of the VTR shown in FIG.

B1, the frequency-modulated IC video signal is placed on the magnetic chip 13 with magnetization loci a1. This is an explanatory diagram when recording is performed as b 1 , and adjacent magnetization trajectories a1 . The direction of b1 is 2α
It is known that the spacing between adjacent tracks can be adjacent or in close contact (hereinafter this relationship will be referred to as "azimuth").

However, in the above conventional method, on the same magnetic tape,
It was not possible to simultaneously record and reproduce many types of video signals with different contents.

Purpose of the Invention The present invention solves the above-mentioned drawbacks of the conventional technology.
An object of the present invention is to provide a magnetic recording and reproducing method that can efficiently record and reproduce many types of video signals with different contents onto a magnetic tape.

Structure of the Invention In order to achieve the above object, the magnetic recording and reproducing method of the present invention uses a rotating head type magnetic recording and reproducing device, increases the tape running speed compared to the normal use, and eliminates the wide unrecorded portion between adjacent tracks. That is, the configuration is such that a guard band is generated, and a magnetization locus of another system is additionally inserted in parallel into the guard band so that the guard band remains even after the guard band is added.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 3 is an explanatory diagram of magnetization trajectories when the running speed of the magnetic tape 3 is increased three times with the configuration not shown in FIG. 1, and the magnetization trajectories a1. A wide unrecorded portion, ie, a guard band ([1) corresponding to two channels, is generated between bI. The present invention makes effective use of this guard band (b).

FIG. 4 shows the trajectory a1.
This is an explanatory diagram of the magnetization trajectory when another magnetization trajectory 2111 is added in parallel to b1, and the reference magnetization trajectory a1, b
l and the added magnetization locus a2゜b2 and a3, b3
It is possible to form magnetization trajectories of three independent phases, and maintain an inverse azimuth relationship between adjacent trajectories.

FIG. 5 is an explanatory diagram of the relative relationship when the three types of video signal magnetization trajectories recorded as shown in FIG. By using a magnetic head A1.31 with a head width of < 1.548 mm), when recording, it is possible to record in complete close contact with adjacent tracks due to overlapping UD recording, and when playing back (Jζ Even if the tracking deviates within the range of the difference between the head width and the rack width, the reproduction output will not change, so the desired channel can be easily selected and reproduced.Video of adjacent or adjacent tracks To reproduce the signal, by shifting the relative position of the magnetization locus and the magnetic head by one or two tracks,
Channel selection is easy, and if it is necessary to reproduce three types of video signals at the same time, as shown in FIG. 6, both magnetic heads A1. This is made possible by distributing two sets of four additional magnetic heads A2, B2, A3, and B3 at equal angles so that an opposite azimuth relationship is established between the adjacent magnetic heads within the 180 degree interval of B1. In the example shown in FIG. 7, three of 83 magnetic heads having the same azimuth angle are stacked at the same location at a pitch of one magnetization locus track width.

The present invention relates to multi-channel recording and playback as described above. For example, if one of the 3-channel channels is left unused, erasure of adjacent tracks due to overlapping recording will not occur. In example C of Fig. 5, 1.5 tracks are recorded on two tracks, that is, 50% wider than the track width when three channels are used, and two tracks with different track widths are recorded. Channel V'
It can be used as is as a TR.

At this time, since the wider track is located outside the target of overlapping recording, it can also be used as an additional recording track for the video signal of the pre-recorded reference track.

At this time, one adjacent side of the wide track has the same azimuth, but since only 1.5 of the two track widths are used, the difference of 0.5 is used as a guard band. This is a used truck, and there is no practical problem at all.

Furthermore, if full compatibility with conventional VTRs is not considered, by increasing the tape running speed, guard bands can be formed between adjacent tracks, allowing the recording timing of multiple channels to be shifted regardless of the azimuth. or switch only the signal of a specific track, or
It is possible to greatly improve the degree of freedom, such as by transferring a rack signal to another track while reproducing it, and it is also possible to increase the tape running speed and increase the number of heads, that is, the number of channels.

Effects of the Invention As explained above, according to the present invention, it is possible to record and reproduce many types of video signals with different contents on the same magnetic tape.
Moreover, the recording/reproducing timing for each channel can be freely selected.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of the rotary head section of a conventional rotary head type magnetic recording/reproducing device, Fig. 2 is an explanatory diagram of the magnetization trajectory on the magnetic tape recorded by the same device, and Fig. 3 is the case of Fig. 2. Fig. 4 is an explanatory diagram of the magnetization trajectory when the tape running speed is increased compared to , Fig. 4 is an explanatory diagram of the magnetization trajectory in an embodiment of the present invention, and Fig. 5 is an illustration of the magnetization trajectory and reproduction in an embodiment of the present invention. Explanatory diagram of the positional relationship with the head, Figures 6 to 7
Each figure is an explanatory diagram of the magnetic head arrangement. 1... Rotating disk, 3... Magnetic tape, A1. A2
. A3. B1. 'B2,83...Replacement of magnetic head Yoshihiro Morimoto Figure 2 Figure 3 Figure Δ

Claims (1)

[Claims] 1.Using a rotating head type magnetic recording and reproducing device, the tape running speed is increased to one level compared to normal use, and a wide unrecorded girt band is generated between adjacent racks, and inside this girt band , a magnetic recording and reproducing method in which additional magnetization trajectories of different systems are inserted in parallel so that the guard band remains even after addition.