JPS593706A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To constitute a recording and reproducing head by supplying a recording signal to a magnetic pole formed by winding a coil around a magnetic material with high magnetic permeability and recording it on a recording medium, and reading variation of a magnetic field from a resonance circuit including a magnetic material piece fitted near the magnetic pole. CONSTITUTION:A high-magnetic-permeability thin film 11 of ''Permalloy'' and a magnetic material 12 of ferrite, etc., are laminated on a glass substrate 10, and the coil 14 is wound in a through window 13 to form the magnetic pole, which is supplied with a writing signal, recording the signal on the magnetic medium. The magnetic material piece 15 is provided atop of the magnetic pole and connected to an oscillation circuit and the resonance circuit which are not shown in a figure via conductive lines 16, 16'. The magnetic material piece 15 varies in impedance with a magnetic field from the magnetic medium to vary the output voltage of the resonance circuit, reading information from the magnetic medium. Consequently, the magnetic head of single structure performs vertical magnetism recording and outputs a reproduction signal with high sensitivity and a high S/N.

Description

[Detailed description of the invention] [Technical field of invention] The present invention relates to a magnetic recording/reproducing device.

[Technical background of the invention and its problems]

Perpendicular magnetization recording has recently been proposed as a method for improving the recording density of magnetic recording. This magnetizes signals in a direction perpendicular to the surface of the magnetic recording medium, and unlike the generally used method of magnetizing signals in the plane, a high recording density can be obtained. The first method of perpendicular magnetization recording is
The main pole excitation type recording system shown in the figure is known. That is, a recording head in which a coil 2 is wound around a main pole 1 made of a high permeability magnetic film is provided in contact with the magnetic layer 4 of a magnetic recording medium 3, and the main pole 1 is excited by passing a signal current through the coil 2. Recording is performed on the recording medium 3 by generating a recording magnetic field.

However, although such a magnetic head is effective as a recording head, when used as a reproducing head, the output voltage is so small that reproduction is virtually impossible. Therefore, there is a problem in that a new conventional ring-shaped reproducing head must be prepared for reproduction.

Furthermore, in the conventional reproduction method using such a ring-shaped head, a sufficiently large magnetic flux is required in order to obtain a sufficiently large reproduction output that is better than 8N, and to do so, it is necessary to widen the track width of the recording track. . Therefore, when performing reproduction using a conventional ring-shaped reproduction head, there is a limit to high-density recording and reproduction.

[Purpose of the invention]

The present invention has been made in view of the above points, and an object of the present invention is to provide a magnetic recording/reproducing device that is capable of reproducing as well as recording, and is capable of obtaining a high-output reproduced signal with a good S/N ratio. It is something to do.

[Summary of the Invention] The present invention provides a perpendicular magnetization recording head with a magnetic pole around which a coil is wound, and a reproducing head with a magnetic pole whose impedance changes in response to changes in the tip of the magnetic pole facing a magnetic recording medium. A resonant circuit is created by providing a body piece and configuring a resonant circuit including this magnetic piece, supplying a high frequency signal to the resonant circuit, and changing the impedance of the magnetic piece according to the recording magnetic field. It is designed to detect changes in voltage and reproduce signals.

[Embodiments of the invention]

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

FIG. 2 is a perspective view showing an embodiment of the head section of the magnetic recording/reproducing apparatus of the present invention, and FIGS. 3(a), (b), and (c) are respectively a front view, a bottom view, and a cross section taken along A- It is a diagram. As shown in the figure, a magnetic pole 11 made of a high permeability magnetic thin film such as permalloy is formed on an insulating substrate, for example, a glass substrate 10. A magnetic material 12 such as ferrite is formed on the magnetic pole 11. This magnetic material 12 is formed on the magnetic pole 11.
This provides a thickness that prevents magnetic saturation and facilitates winding of the coil. A through hole 13 is provided in the glass substrate 10 corresponding to both sides of the magnetic pole 11, and the glass substrate 10. A coil 14 is wound around the magnetic pole 11 together with the magnetic body 12 . The magnetic pole 11 around which the coil 14 is wound operates as a main pole excitation type recording head.

A magnetic piece 15 made of, for example, ferrite or YIG is provided close to the tip of the magnetic pole 11 that is involved in recording. This magnetic piece 15 operates as a reproducing head, has a thickness of, for example, 1 μm or less, and its impedance changes in response to changes in the magnetic field from the magnetic recording medium. Lines 16 and 16' made of a conductive material such as iron or gold are taken out from both sides of the magnetic piece 150.

These lines i6, 16' are for extracting the change in impedance of the magnetic piece 15, and act as an inductance element for high frequency signals. In other words, Muno railway line 16゜1
6' itself constitutes a part of the high frequency circuit.

FIG. 3 shows a recording/reproducing circuit using such a magnetic bed. A recording circuit 51 is connected to the nine coils 14 wound around the magnetic poles 11 for perpendicular magnetization recording, and a recording signal is sent to the coils 14 via the recording circuit 51. The magnetic field generated by the magnetic pole 11 magnetizes the magnetic piece 15 .

A magnetic field is generated again from the magnetized magnetic piece 15 and applied to the perpendicular magnetic recording medium 50 to perform signal recording. Although the magnetic material piece 15 is provided with a gap from the magnetic pole 11 in this embodiment, it may be provided in complete contact with the magnetic pole 11 if the influence on the reproducing circuit can be ignored.

On the other hand, the line 16°16' taken out from the magnetic piece 15
One side is grounded, and the other side is connected to the high frequency oscillator 54 via a resonance capacitor 52 and a matching capacitor 53, as well as to a peak detection circuit 55. There is a matching capacity of 5 in between.
5 is connected to the magnetic material piece 15. Track 16.16'
The resonant capacitor 52 constitutes a high frequency resonant circuit, and a high frequency oscillator 54 supplies a signal with a frequency equal to the resonant frequency. This signal flows through the magnetic piece 15. At this time, since the magnetic material piece 15 has a very small cross-sectional area,
The signal current flows not only to the surface of the magnetic piece 150 but also to the inside, and as a result, the magnetic piece 15 itself functions as an impedance element (specifically, an element having inductance or capacitance depending on how you look at it). Become. The impedance of this magnetic piece 15 changes as the magnetic field from the magnetic recording medium 50 changes.

A change in impedance due to a change in the magnetic field of the lever causes a change in the output voltage of the resonant circuit, as shown in FIG. Therefore, by detecting the output of the resonant circuit using the peak detection circuit 56, the signal recorded on the magnetic recording medium 50 can be reproduced.

In order to obtain a large change in the output of the resonant circuit with respect to a change in the magnetic field of the magnetic recording medium 50, a magnetic bias M1 is applied from the outside to the magnetic piece 15, and the steep part of the curve in FIG. It is desirable to use In response to this demand, in the present invention, a bias magnetic field can be applied to the magnetic piece 15 using the recording magnetic pole 11. That is, the switch 57 can be switched between recording and reproduction, and the coil 12 wound around the magnetic pole 11 is connected to the bias power supply 58 during reproduction. By doing so, a bias magnetic field can be generated from the magnetic pole 11 and applied to the magnetic piece 15. Of course, it is also possible to apply a bias magnetic field from the outside.

Furthermore, when the variation width of the magnetic field from the magnetic recording medium 50 is large, the output linearity deteriorates as is clear from the characteristic curve of FIG. 5. Therefore, in order to compensate for this, a part of the output of the detection circuit 56 can be negatively fed back and fed to the coil 12 of the magnetic pole 11, as shown in FIG.

〔Effect of the invention〕

As described above, according to the magnetic recording and reproducing apparatus of the present invention, a magnetic head having a single structure can perform perpendicular magnetization recording and can also reproduce recorded signals. In particular, during reproduction, unlike the conventional reproduction method that extracts and reproduces the flux of the recording magnetic field from the magnetic recording medium, it is possible to detect even the slightest change in magnetic flux with high sensitivity, and the reproduction output energy can be detected with high sensitivity. Since it can be supplied from a high frequency signal oscillation source, even if the recording track width is narrowed, it is still 8N
A sufficiently large output with good Ji can be obtained, and even higher density recording and reproduction can be realized.

[Brief explanation of drawings]

FIG. 1 V is a diagram showing the conventional main pole excitation type magnetic recording system.
FIG. 2 is a perspective view showing the structure of the head section of the magnetic recording/reproducing apparatus of the present invention, and FIGS. A front view, a bottom view, and a sectional view; FIG. 4 is a configuration diagram of the recording/reproducing circuit of the apparatus of the present invention; FIG. 5 is an explanatory diagram of its operation; FIG. 6 is a diagram showing another configuration of the recording/reproducing circuit. . 11...Magnetic pole, 14...Coil, 15...
・Magnetic material piece, 16, 16... conductive line, 5
1...Recording circuit, 52...Resonance capacitor, 54...
...High frequency signal oscillator, 56...Peak detection circuit. Agent Patent Attorney Noriyuki Norichika (and 1 other person) 1st
Figure 5 Figure 3 (α) (CJ Figure 4 Figure 5

Claims (3)

[Claims] (1) A magnetic pole made of a high permeability magnetic material that generates a magnetic field perpendicular to the magnetic recording medium, a coil wound around this magnetic pole to which a recording signal is supplied during recording, and a magnetic recording medium of the magnetic pole. a magnetic piece provided in contact with or close to the tip facing the magnetic recording medium and whose impedance changes in response to changes in the recording magnetic field from the magnetic recording medium, and a resonant circuit configured to include the magnetic piece; A magnetic recording and reproducing apparatus comprising: means for supplying a high frequency signal to the resonant circuit; and means for detecting a change in voltage generated in the resonant circuit. (2) A magnetic recording and reproducing apparatus according to claim 1, characterized in that a bias current for generating a bias magnetic field during signal reproduction is caused to flow through nine coils wound around the magnetic poles. (3) The magnetic recording/reproducing device according to claim 1, wherein the magnetic pole and the magnetic piece are formed on the same substrate.