JPS5916105A - Magnetic recording and reproducing system - Google Patents

Abstract

PURPOSE:To make the high-density recording and reproducing possible, by using a material including a magnetic substance, whose high frequency characteristics are changed when a recording magnetic field is applied, as a magnetic recording medium. CONSTITUTION:In respect to the recording medium, a magnetic layer 3 whose high frequency characteristics are changed greatly by the change of the magnetic field is formed on a magnetic recording layer 2, and the recording magnetic field remains in the magnetic layer 2 to record a signal on the magnetic layer 3 as a change of high frequency loss or the like of the recording medium. A high frequency signal is supplied from a high frequency oscillator 52 to a receiving stylus 56 for reproducing head through a magnetic recording medium 51, and a variation of transmission loss or the like for the high frequency signal corresponding to the recording magnetic field is taken out as a reproduced output. Consequently, even a faint change of the high frequency characteristics is detected with a high sensitivity, and a large output having high-SN ratio is obtained by the high frequency oscillator independently of a wide recording track, and signals are recorded and reproduced with a high density.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a magnetic recording and reproducing method using a novel magnetic recording medium.

[Technical background of the invention and its problems]

The magnetic recording and reproducing method that has been commonly used in the past uses a magnetic recording medium with a magnetic layer of γ-Fe2O3 or the like formed on a base, and a magnetic head generates a recording magnetic field proportional to the recorded signal. Signals are recorded by magnetizing the magnetic recording medium, and reproduction is performed by detecting changes in the electromotive force induced in the magnetic head by the recording magnetic field left on the surface of the magnetic recording medium.

However, in such conventional magnetic recording and reproducing methods, a sufficiently large magnetic flux is required in order to obtain a sufficiently large reproduction output with a good signal-to-noise ratio (to do so, the recording track width must be wide), and high-density This was causing a problem with recording.

[Purpose of the invention]

The present invention has been made in view of these points, and it is an object of the present invention to provide a magnetic recording and reproducing method that uses a new magnetic recording medium and is capable of high-density recording and reproducing.

[Summary of the invention]

That is, the present invention uses a magnetic recording medium that includes a magnetic material whose high frequency characteristics, such as high frequency loss or magnetic permeability, change when a recording magnetic field is applied, and signal recording is performed on this magnetic recording medium. This is done by applying a magnetic field to cause a change in the high frequency characteristics of the magnetic recording medium.
Reproduction is performed by supplying a high frequency signal to the signal recording section of this magnetic recording medium, extracting the supplied high frequency signal from this signal recording section, and detecting the change in the signal level. It is something. The signal level of the high frequency signal supplied to the signal recording section changes in response to changes in the high frequency characteristics of the magnetic recording medium in the signal recording section, such as changes in high frequency loss. Therefore, by detecting this signal change, the recorded signal can be reproduced.

〔Effect of the invention〕

According to the magnetic recording and reproducing method of the present invention, even the slightest change in the high frequency characteristics of a magnetic recording medium can be detected with high sensitivity, and there is no need for a wide recording track as in the conventional method. Since the output energy can be supplied from a high frequency oscillator, a large output with a good SN ratio can be obtained. Therefore, higher density recording and reproduction is possible compared to conventional magnetic recording systems.

[Embodiments of the invention]

The present invention will be described in detail below with reference to the drawings.

FIGS. 1 to 7 each show an example of the configuration of a magnetic recording medium used in the magnetic recording/reproducing method of the present invention. First, the magnetic recording medium shown in FIG. 1 has a base IVC magnetic recording layer 2 made of, for example, polyester or acetate. On the magnetic recording layer 2 of a conventional magnetic recording medium coated with a cobalt chromium layer, etc., high frequency characteristics such as high frequency loss and magnetic permeability μ are shown in FIG. 8 by changing the magnetic field of YIG, Sendust, etc. The magnetic layer 3 is formed to vary greatly as shown in FIG. Further, FIG. 2 shows the magnetic recording layer 2 and magnetic layer 3 of FIG. 1 formed in reverse. Furthermore, FIG. 3 shows a magnetic recording layer 2 mixed with YIG, Sendust, etc., specifically the above-mentioned γ-P"
Magnetic powder such as e203 or barium ferrite and YI
It is formed on the base l by mixing magnetic powder such as G, Sendust, etc., which exhibits large changes in high frequency characteristics with changes in the magnetic field.

If the surface of the recording medium is a conductive layer such as cobalt or chromium, 5i is applied to the surface as an insulating layer and wear-resistant material.
A film such as SN or a lubricating oil film may be provided, and this insulating layer may also be a film such as YIG which also serves as a magnetic material layer whose high frequency characteristics change depending on the magnetic field.

In addition, the magnetic recording medium shown in FIGS. 4 to 6 is the magnetic recording medium shown in FIGS. For example, a conductive thin film layer 4 of copper, gold, permalloy, etc. is formed. This conductive thin film layer 4 functions similarly to that of a two-layered perpendicular magnetization recording medium and can perform effective reproduction. Note that when a magnetic material such as permalloy is used as the conductive thin film layer 4, the loss and μ at high frequencies change depending on the recording magnetic field, so it can also be used as the magnetic layer 3 whose high frequency characteristics change depending on the magnetic field. Furthermore, a recording medium having a structure using such a conductive magnetic material can also be used as a recording medium having a two-layer structure in the case of perpendicular recording.

7 corresponds to the magnetic recording medium of FIG. 4, but the layers 2, 3, and 4 are formed on both sides of the base 1. In FIG. Although not shown in the drawings, it is also possible to form layers 2, 3.4 on both sides of the magnetic recording media shown in FIGS. 5 and 6. In this case, the two conductive layers 4 are closely electrostatically bonded to each other, and the reproducing effect can be particularly enhanced in the reproducing apparatus shown in FIG. 9, which will be described later.

The magnetic powder itself constituting the magnetic recording layer 2 may be of such a type that its high frequency characteristics change depending on the magnetic field.

Next, a magnetic recording and reproducing method of the present invention using such a magnetic recording medium will be explained. First, recording is performed by supplying a recording signal current to the magnetic head in the same way as normal in-plane direction or known perpendicular magnetic recording, generating a recording magnetic field proportional to this recording signal current, and using this recording magnetic field to drive the magnetic recording medium. magnetize. At this time, a recording magnetic field remains in the magnetic layer 2 made of γ-Fe, 03 or barium ferrite, and this recording magnetic field changes the high frequency characteristics such as υY, high frequency loss of the magnetic layer 3 made of IG or Sendust. Therefore, the signal is recorded as a change in high frequency loss or the like of the recording medium.

Next, this recorded signal can be reproduced by a reproduction method as shown in FIG. In other words, in the same figure, 5
Reference numeral 1 denotes a magnetic recording medium having the above-mentioned configuration, and a high frequency oscillator 52 is provided on the back surface, that is, the surface on the pace side, and the output thereof is supplied to the magnetic recording medium 51 via a high frequency output coupling circuit 53. It is configured to The high frequency oscillator 52 and the high frequency output coupling circuit 53 are housed in a lead box 54 except for the contact S of the high frequency output coupling circuit 53 with the magnetic recording medium 51. Also, a magnet 5 for applying a bias magnetic field to the magnetic recording medium 51
5 is also placed inside the shield box 54.

On the other hand, a receiving needle 56 for a reproducing head is provided on the magnetic layer surface side of the magnetic recording medium 51 in contact with the magnetic surface of the magnetic recording medium 51 . A detection circuit 60 consisting of a detection diode 57, a resistor 58, and a capacitor 59 is connected to the reproducing head receiving needle 56. The receiving needle 56 for the playback head and the detection diode 57 are also placed in the shield box 61.
It is stored inside.

In such a configuration, the high frequency oscillator 52 supplies a high frequency signal of, for example, about 100 MHz to 1000 Ml-Iz to the reproducing head receiving needle 56 via the magnetic recording medium 51. At this time, the high frequency loss of that portion of the magnetic recording medium 51 changes depending on the recorded magnetic field, so the transmission loss for the high frequency signal changes.

As a result, a high frequency voltage corresponding to the recording signal is obtained at the receiving needle 56 for the reproducing head. This high-frequency applied pressure is peak-detected by the detection circuit 60, and the variation thereof is extracted as a reproduction output. In this way, the recorded signal is reproduced. In addition,
The bias strength of the bias magnetic field magnet 55 of the high frequency output coupling circuit 53 is adjusted appropriately in relation to the playback output level or the distortion of the playback signal, for example, so that the change in the playback output can be large or the change in the playback output can be linear. Adjustments are identified.

In such a reproducing method, the reproducing head receiver 56 and the high frequency output coupling circuit 53 are adapted to the main magnetism and the auxiliary magnetism, respectively, in the auxiliary magnetic pole excitation type perpendicular magnetization recording, so that the reproduction head receiver 56 and the high frequency output coupling circuit 53 are adapted to the main magnetism and the auxiliary magnetism, respectively, in the auxiliary magnetic pole excitation type perpendicular magnetization recording. When applied as a reproducing method for a magnetic recording medium having the conductor thin film layer 4 shown in (a), the conductor thin film No. 4 can be effectively used.

FIG. 1O shows an application of the above reproduction method to multi-channel reproduction. A plurality of -C receiving needles 56 for the reproducing head are provided on the magnetic layer side of the magnetic recording medium 51 corresponding to each channel, and one high frequency coupling circuit 53 is provided on the back side to be commonly coupled to the receiving needles 56 for each head. This allows multi-channel playback with a simple configuration. Note that the receiving needles 56 are formed side by side on a glass layer formed on a conductive substrate.

11 and 12 show modifications of the reproduction method explained in FIG. 10, respectively. First, in the one shown in FIG. 11, a magnetic material 64 whose high frequency characteristics change depending on the recording magnetic field from the magnetic recording medium 51 is provided on a part of the tip of the receiving needle 56 for the reproducing head. The playback sensitivity can be increased by combining changes in the high frequency characteristics of the

Furthermore, the one in Figure 12 uses only the regenerative wave receiving circuit section,
A blood high frequency oscillator 52 is coupled to a reception 9f56 for the reproducing head. In this case, due to changes in the high frequency characteristics of the magnetic recording medium, an LO resonance circuit (L of the receiving needle 56,
Since the Q or resonance frequency of C) between
You can use this to play.

Although not shown, a needle similar to the receiving needle shown in FIG. 9 is used in place of the high-frequency output coupling circuit 53 in FIG. It is also possible to receive and reproduce the data using the .

Further, FIG. 13 shows an example in which the method shown in FIG. 9 is applied to a helical type VTR. As shown in the figure, cylinder 65
A high frequency coupling circuit 53 having a shape along
1 will run. j% in the high frequency coupling circuit 53
A high frequency signal is supplied from the frequency oscillator 52, and the rotating head 6
6, the high frequency coupling circuit 5 is passed through the tape 51 by using a receiving needle for the reproducing head as shown in FIG.
3 and a rotary head 66 can be combined, making it possible to reproduce even a rotary head type VTR.

Furthermore, FIG. 14 shows an improved reproduction device of FIG. 9 so that it can also be used as a perpendicular recording head. That is, as shown in the figure, a high permeability magnetic thin film 68 such as permalloy whose surface is coated with a conductive thin film 67 of gold or the like is used as the receiving needle 56, and a high-permeability magnetic thin film 68 such as permalloy whose surface is coated with a conductive thin film 67 of gold or the like is used as the high frequency coupling circuit 53. A magnetic material 69 such as sendust coated with a conductive thin film 67 is used, and a coil/I/70 is wound around it for flowing a recording signal current. In the case of perpendicular recording, the magnetic thin film 68 of the receiving needle 56 acts as the main magnetic pole, and the magnetic body 69 acts as an auxiliary magnetic pole, allowing perpendicular recording. During playback, the magnetic thin film 68 of the receiving needle 56 and the high-frequency coupling circuit 53 serve as the 4-ton 4 raw thin film. 67 act to perform the same reproducing operation as in the case of FIG.

FIG. 15 shows another embodiment of the reproduction method of the present invention. The reproduction methods explained in FIGS. This method performs reproduction by detecting changes in high-frequency transmission characteristics in the in-plane direction of a magnetic recording medium due to a recording magnetic field.

That is, the seed conductor block 71 is provided so as to be in contact with the magnetic recording medium 51 running perpendicularly to the abrasive surface. Two through holes 72 and 73 are provided in this block 71 in a V-shape, for example, as shown in the figure, so as to connect the surface in contact with the magnetic recording medium 51 with the other surface. A high frequency transmission line 74 is provided coaxially within one through hole 72 so that one end thereof is in contact with the surface of the magnetic recording medium 510. A high frequency oscillator 7 is connected to the other end of this transmission line 74.
5 is connected, and a high frequency signal is supplied from this high frequency oscillator 75 to the magnetic recording medium 51 via the transmission line 74.

On the other hand, in the other through hole 73, a reproduction receiving needle 76 is provided, one end of which is in contact with the magnetic recording medium 51 and close to the high frequency transmission line 74 at a distance of the recording track width W or more. ing. A peak detection circuit 77 is connected to the other end of the reproducing receiving needle 76.

As mentioned above, since the high frequency loss in the in-plane direction of the magnetic recording medium 51 changes in response to the recording magnetic field, a voltage corresponding to the loss is obtained in the received wave *t76, and this causes the signal to be can be played.

This reproducing method has the advantage that reproduction can be performed only on one side of the magnetic recording medium 51, and the configuration becomes simpler when all rotary heads are used, such as a helical scan 7 VTR.

As explained above, when the magnetic recording medium of the present invention is used, the recording magnetic field is recorded as changes in high frequency characteristics such as high frequency loss, and these changes can be detected with high sensitivity by the reproduction method as explained in FIGS. 9 to 16. can be detected. Therefore, unlike the conventional method, a wide recording track is not required, and since the reproduction output energy can be supplied from the crystal frequency oscillator, a large output with a good S/N ratio can be obtained. Therefore, high-density recording and reproduction becomes possible. In addition, in conventional magnetic recording and reproduction, in order to obtain an output that corresponds to changes in recording magnetic flux, there were problems with the running speed and uniformity of frequency characteristics of the magnetic recording medium, but with the present invention, changes in high frequency loss, etc. Because of this, there is no problem with the relationship between the running speed and output of the magnetic recording medium, and recording and reproduction with extremely good frequency characteristics is possible.

The magnetic recording medium of the present invention may be in the form of a tape or in the form of a tape depending on the purpose.
It is formed into a disk shape and is used in audio tape recorders and V
It can be widely used in magnetic disks, magnetic drums, magnetic tapes, recording devices, etc. in computer information processing systems, including TR.

[Brief explanation of the drawing]

1 to 7 are diagrams each showing a configuration example of a magnetic recording medium used in the present invention, and FIG. 8 is a diagram showing an example of a change in high frequency loss with respect to a magnetic field of this magnetic recording medium,
FIG. 9 is a diagram showing an embodiment of the reproduction method of the present invention, and FIG.
Figures 12 through 12 are diagrams showing modified examples of the reproduction method shown in Figure 9, Figure 13 is a diagram showing an application example of the reproduction method shown in Figure 9, and Figure 14 is a diagram showing a head configuration capable of recording and reproducing. The figure shown in FIG. 15 is a diagram showing another embodiment of the reproduction method of the present invention.
High frequency characteristic change magnetic layer 51...Magnetic recording medium 52...High frequency oscillator 5
3... High frequency output coupling circuit 56... Receiving needle for playback head 60... Detection circuit 61... Shield box 63.
...Reproducing head coupling circuit 64...High frequency characteristic changing magnetic material 65...Cylinder 66...Rotating head 67...
...Conductive thin film 68...Magnetic thin film 69...Magnetic material 75...High frequency oscillator 76...Receiving needle agent for playback head Patent attorney Noriyuki Chika (and one other person) Figure 1
(Figure 2, Figure 3, Figure 4, Figure 5, Figure 6, Figure 7, Figure 9) Figure 10, Figure 11, Figure 12, Figure 13

Claims (3)

[Claims] (1) Using a magnetic recording medium containing a magnetic material whose high frequency characteristics change depending on the magnetic field, signal recording is performed by applying a recording magnetic field corresponding to the signal to be recorded to the magnetic recording medium, and the signal recording section In addition to supplying high frequency signals,
The supplied high frequency signal is taken out through the signal recording section, and the signal is reproduced by detecting a change in the high frequency signal corresponding to a change in the high frequency characteristic due to the recording magnetic field of the magnetic recording medium. Features a magnetic recording and reproducing method. (2) A high-frequency signal supplying means and a receiving means are provided facing each other with a magnetic recording medium in between, and the signal is reproduced by detecting changes in high-frequency transmission characteristics due to a recording magnetic field in the perpendicular direction of the magnetic recording medium. A magnetic recording and reproducing system according to claim 1. (3) A patent claim characterized in that a high frequency supply means and a receiving means are provided on one side of a magnetic recording medium, and a change in high frequency transmission characteristics due to a recording magnetic field in the in-plane direction of the magnetic recording medium is detected and a signal is reproduced. The magnetic recording regeneration method according to item 1.