JPS5930208A - magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To perform short-wavelength recording and reproduction during reproduction by performing recording at most for a period of reproducing-head width movement on a recording head recording medium and then stopping the recording at least for the next period of movement of the distance during vertical magnetic recording. CONSTITUTION:A switch SW2 is turned on in a time t1-t2, and a switch SW1 is turned on in a time t2-t3. A signal passed through the switch SW2, i.e. signal detected by a heat tip part is delayed through a delay circuit 5 by a time t14' phase-inverted by a phase inverting circuit 6, and sent to a mixing circuit 7. At this mixing circuit 7, this signal has the same waveform as a signal passed through the switch SW1 has, and they are added together to improve the S/N ratio by 6dB. This vertical recording and reproducing system is free of lengthwise recording demagnetization and gap loss during reproduction, so that short- wavelength recording and reproduction are performed.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a magnetic recording/reproducing apparatus using a trans-based recording method that leads to short wavelength magnetic recording.

Conventional configuration and its points of interest Conventionally, in magnetic recording and reproducing devices such as video tape recorders, a magnetic tape is used as a magnetic recording medium, and the magnetic head or magnetic tape is moved roughly in the width direction of the head. By running it at a right angle or at an azimuth angle of several degrees, papi recordings and replays are performed.

Such a magnetization method that magnetizes the medium in the direction of motion is suppressed by longitudinal magnetization, and in VC machines such as video tape recorders, recording demagnetization increases from a recording wavelength of about 1 μm, and shorter wavelength recording It was difficult to put it into practical use.

On the other hand, perpendicular magnetization methods have been studied for the purpose of recording at even shorter wavelengths, and many proposals for practical use have been made. There is a drawback that the configuration is complicated, such as the need for a JmJ1g structure of a vertically magnetized film and a horizontally magnetized film.

In addition, so-called transverse recording has been proposed, in which the head direction of the magnetic head is made almost the same as the running direction of the magnetic tape. It is believed that only wavelengths longer than the head width (actually, about 3 times or more) can be recorded and reproduced, and the actual 5J wavelength recording is significantly shorter than the width of the head.
It didn't reach t.

OBJECTS OF THE INVENTION It is an object of the present invention to provide a magnetic recording and reproducing apparatus which eliminates the above-mentioned drawbacks of the prior art and makes recording at significantly shorter wavelengths possible.

In order to achieve the object of d-pi due to the structure of the Tsurume, the present invention provides a transverse recording type magnetic recording/reproducing apparatus having a magnetic head and a recording medium that moves relatively in the width direction of the magnetic head, a recording/reproducing head or a recording head having a head width and a reproducing head having a head width, the recording/reproducing head or recording head recording a signal only in a section in which the recording head or the recording head relatively moves at most a distance on the recording medium; Next, recording is stopped during a section in which the recording/reproducing head or the recording head moves relatively at least a distance on the recording medium.

Furthermore, the present invention includes a reproducing head having a head width, and the reproducing head uses a recording medium in which at most an interval of L is recorded, and the next interval of at least L is unrecorded. This device is configured to reproduce signals by reproducing signals.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. 1st
Figure (ILI is a recording head (1) for transverse recording,
The recording waveform (2), the magnetic tape (3), the coil (4), the tape running direction (A), the recording head width L, and the gap width G are shown, and (b) shows the back view. The magnetic tape (3) moves in the width direction of the recording head (1).

Here, the recording waveform (2) can be considered to be determined by the recording signal applied when the magnetic tape (3) passes through the gap between the ends g1 and g2 of the recording head (1), and the wavelength λ of the recording signal is It has nothing to do with width. That is,
It can be seen that it is possible to record a signal with a wavelength shorter than the width of the recording head. This was difficult to achieve with the conventional longitudinal magnetization method due to recording demagnetization.

Next, FIG. 2 shows an example of reproducing a signal recorded in this manner. FIG. 2 (&) shows a signal that is half a wavelength larger within the width of the head, and at this time the reproduction output is at its maximum.

This means that if we consider that the reproduced output is a change in the magnetic flux that follows inside the head core, then the wavelength λ of the reproduced signal is equal to the head lll1jL and λ=
This is clear from the fact that the amount of change in magnetic flux is maximum when the relationship is 2L.

In other words, a signal with one wavelength included in the width of the head shown in FIG. 2 (1)) is dropped. At this time, even if the reproducing head moves, no change in magnetic flux occurs within the core, and the reproducing output becomes zero. In other words, once the wavelength λ=-(n is a natural number) of the reproduced signal is satisfied, the reproduced output becomes O, which is considered to correspond to the gap loss in conventional longitudinal recording.

Next, let us consider the reproduced output when only one wavelength is recorded in FIG. 2(b). Figure 3 (t,)
The leading edge S of the recording signal is the leading edge of the playback head.

(t2) is a diagram showing the moment when the head IIIL is occupied by one wavelength person.
5) shows the image at the moment the playback ends. Here, only the gap portion of the reproducing head is shown. Kimi Kamime (tl)
From the state of (t2) to the state of (t3), dφ4, as shown in the figure. Here, "" indicates the playback output.

Here, during reproduction, the signal passing between the head end portion h2 and the head rear end portion h2 shown in FIG. 3 does not contribute to the change in magnetic flux φ passing through the head core. , = 0), the current dφ is not reflected in the playback output.In other words, in the Nyu output car clt in Fig. 4, the period t1 to t2 is considered to be the playback waveform at the head tip h1, and the period t2 to t3 is the waveform after the head. The end h2 is considered to be a p-regeneration waveform.

In this way, when reproducing this signal at wavelength λ=L/n (LH head width, n: natural number), as shown in FIG. 2(b), no reproduction output can be obtained with continuous waves; Reproduction is possible by recording in bursts as shown in FIG.

As the reproduced output, the waveform obtained by IC4 between t and t2 in FIG. 4 may be used, the waveform obtained between t2 and t3 may be used, or both waveforms may be synthesized. An example of this synthesis method is briefly described below in Figure 5 (a).
is a reproduced waveform, (b) is a signal waveform reproduced at the tip of the head, (0) is a waveform obtained by delaying (b) by a time T1 during which the reproduction head moves a relative distance on the tape, (d-1 is a waveform obtained by inverting the phase of (C), and is obtained by superimposing (e) f″i reproduced waveform and (d) waveform.
It is clear that the S/C ratio is improved by 6 dB.

A circuit block diagram for experimenting with this synthesis method is shown in FIG. The circuit consists of an amplifier (8), an analog switch (SW
'l) (SW2), a delay circuit (5), a phase inversion circuit (6), and a mix circuit (7). Between t1 and t2 shown in Fig. 4, the switch (EIW2) is turned off.
NL, the switch (SWI) is turned on between t2 and t5. The signal that has passed through the switch (SW2), that is, the signal that has been detected at the tip of the head, is sent to the delay circuit (5) for the time T.
, is delayed, phase inverted by a phase inversion circuit (6), and then sent to a mix circuit (7). This mix circuit (7
), the above signal and the signal passing through the switch (SWI) have the same waveform, and by adding them together, El/N can be improved by 6 dB.

Here, in the above-mentioned recording and reproducing method, recording demagnetization in the longitudinal direction and gap loss during reproduction do not occur conventionally, so short wavelength recording and reproduction is possible.

, Therefore, next, an example of short wavelength recording and reproduction will be shown. FIG. 7 shows an example of d-pi recording and reproduction at a wavelength of 1 μm with a head width L=5 μm. (a) is the state at the time of recording, (1))
(C) shows the reproduced waveform, and (d) shows the output waveform when the S/IJ is improved using the mix circuit. In other words, it can be seen that by recording in bursts, short wavelength recording and reproduction is possible regardless of the head width.

Here, the recording section is determined by the reproduction head width and has no relation to the recording head width, so the recording head width does not need to be L. It is also possible to use a recording/reproducing head having a wider head width.

In this way, in conventional transverse recording, it was not possible to reproduce a signal with a wavelength of λ-=L/n (n is a natural number) when the width of the reproducing head was taken. Recording is performed only while moving at most a distance L (playback head IIQiI) on the recording medium, and then recording is stopped while moving for at least the next distance, so-called burst recording. VC is used to reduce gap loss during playback. This does not occur, and the short wavelength recording returns to "J".

Further, as the reproduction output, a reproduction signal from the tip of the reproduction head, that is, information obtained while the reproduction head moves relatively at most a distance on the recording medium after the signal begins to be written may be used. It is also possible to use the reproduction signal from the rear end of the reproduction head, that is, the information obtained after the reproduction head has moved a relative distance on the recording medium after the signal begins to be reproduced, or the information obtained from both of the above information may be used. In the above explanation, an example of analog 1-digit recording and reproduction was shown, but the present invention is in principle suitable for digital recording, and in that case, the 2-bit length of the digital signal is
It can be considered that this corresponds to one wavelength mentioned in section e.

Effects of the Invention As is clear from the above explanation, according to the present invention, since transverse recording is performed, no recording width value occurs during recording, and no gap loss occurs during reproduction.
It has the great advantage of dramatically increasing recording and reproducing density.

[Brief explanation of the drawing]

Figure 1 is a schematic perspective view and back view showing the entire concept of transverse recording, Figure 8g2 is a schematic configuration diagram of transverse playback,
Fig. 3 is a waveform diagram showing reproduction in the present invention, Fig. 4 is a waveform diagram showing magnetic flux in the core and reproduction output in reproduction according to the invention, and Fig. 5 is for explaining the reproduction method of the present invention. FIG. 6 is a block diagram showing an example of a reproduction method, and FIG. 7 is a waveform diagram showing high-density recording and reproduction. (1)...Magnetic head, (2)...Recording waveform, (3
)...Magnetic tape, (4)...Coil, (5)...
・Delay circuit, (6)...Inverting circuit, (7)...Mix circuit agent Horo Morimoto Private use 1 Figure 8 fL → Z, 7° Figure 4 Figure 5 Figure 4 Figure 7 Figure (4)
−(
νλ

Claims (1)

[Scope of Claims] L A transverse recording type magnetic recording/reproducing device having a magnetic head and a recording medium that moves relatively in the width direction of the magnetic head, the recording/reproducing head having a head width or a recording head. A reproducing head having a head width is provided, and the recording/reproducing head or the recording head allows
Signals are recorded over a distance that is relatively at most on the recording medium, and then the recording/reproducing head or the recording head moves on the recording medium relatively at a distance of at least 1@! A magnetic recording and reproducing device characterized in that the length of the L-moving section is V-shaped to stop recording. 2. The magnetic recording/reproducing apparatus according to claim 1, wherein the wavelength of the recording signal is shorter than the head width of the recording/reproducing head or the reproducing head. - A transverse recording type magnetic recording and reproducing device having a magnetic head and a recording medium that moves relatively in the width direction of the magnetic head, comprising a reproducing head having a width of the head and having a distance of at most 1. A magnetic recording and reproducing apparatus characterized in that the reproducing head reproduces a recording medium in which only one section is recorded and the next at least a distance is not recorded to obtain an external signal. 4. The reproduction signal is obtained only from the output of the reproduction head obtained during a period in which the reproduction head moves relatively at most a distance on the recording medium after the reproduction head starts reproducing the signal recorded on the recording medium. Special? ff A magnetic recording and reproducing device according to claim 3. 5. The playback signal is transmitted from the time when the playback head starts playing back the signal recorded on the recording medium to the point where the playback head has roughly moved a distance #IL from the point where the playback head has moved a relative distance on the recording medium. The magnetic eye according to item 3 of the range of the clock 1, characterized in that the magnetic eye is obtained only from the playback head output obtained in the interval. G Reproduction No. 18 refers to the signal 881 obtained during the period in which the reproduction head starts reproducing the signal recorded on the recording medium and moves a relative distance on the recording medium, and then further relatively The second signal obtained during the distance traveled is used as information 1. After delaying the first signal for a predetermined time,
4. The magnetic recording and reproducing apparatus according to claim 3, wherein the magnetic recording and reproducing apparatus is obtained by combining with the second signal S2.