KR0139315B1 - Magneto-optical recording apparatus - Google Patents

Abstract

The present invention provides an optical magnetic recording apparatus including an optical head for irradiating a magneto-optical recording medium with a light beam and a magnetic head for applying a magnetic field to the recording medium, wherein the core of the magnetic head is made of a single crystal ferrite material. The easy magnetization direction based on the magnetic anisotropy of the single crystal ferrite forming the main magnetic pole portion of the core coincides with the magnetic field direction applied to the magneto-optical recording medium or is generated by the coil of the coil winding of the core of the magnetic head. A magneto-optical recording apparatus is provided, which is arranged to substantially coincide with the magnetization direction.

Description

Magneto-optical recording device

1 is a schematic side view of a conventional example

2 is a side view schematically showing a main part of the magneto-optical recording apparatus according to the first embodiment of the present invention.

3 (a) and 3 (b) are side views schematically showing main parts according to another embodiment of the present invention.

Figure 4 is a side view schematically showing the main part according to another embodiment of the present invention

Figure 5 is a side view schematically showing the main part according to another embodiment of the present invention

6 is a diagram showing the relationship between the composition of the ferrite single crystal and the magnetic anisotropy constant according to the present invention.

7 shows an ideal embodiment of the present invention.

8 is a graph showing the temperature dependence on the permeability of a ferrite single crystal containing MnO.ZnO.Fe ₂ O ₃ .

9 is a graph showing another temperature dependence on the permeability of a ferrite single crystal containing MnO.ZnO.Fe ₂ O ₃ .

Explanation of symbols on the main parts of the drawings

(1) ... magneto-optical recording media

(23) ... recording layer

(3) ... magnetic head

(4) ... optical head

(5) ... core

(5P) ... State Department

(6) ... coil

(7) ... slider

(8) cap

The present invention relates to a magneto-optical recording apparatus for performing magneto-optical information recording by irradiating a magneto-optical recording medium with a laser beam and applying a modulating magnetic field to the magneto-optical recording medium opposite to the irradiation side.

In this type of magneto-optical recording apparatus, information recording is performed as follows. The laser beam emitted from the semiconductor laser is converged by a optical head into a beam spot having a diameter of about 1 μm, for example, irradiating a magneto-optical recording medium of a disc, and then magnetic head in a vertical direction of the magneto-optical recording medium. Apply the external modulator magnetic field to the position corresponding to the irradiation position through.

For example, as shown in FIG. 1, the main part of the magneto-optical recording medium is constituted. There is a recording layer 2 having a perpendicular magnetization film formed on top of the disc magneto-optical recording medium 1. The magnetic head 3 is arranged to face the recording layer 2 on the top of the magneto-optical recording medium 1 which is movable in the track direction. Further, the optical head 4 is arranged to face the magnetic head 3 at the bottom of the magneto-optical recording medium 1 which is movable in the track direction and in the focusing direction.

The magnetic head 3 includes a U-shaped core 5 made of a magnetic material having a high permeability, for example, a sintered ferrite material, a coil 6 wound around the main magnetic pole portion of the core 5, and a magneto-optical magnet. It consists of a slider 7 which is in a floating state to hold the magnetic head 3 in a slight gap with the surface of the recording medium. The slider 7 is made of a nonmagnetic material such as ceramic, for example.

In the information recording, while rotating the disk magneto-optical recording medium 1 at a high speed, the laser beam from the optical head 4 is converged to a beam spot b having a diameter of about 1 占 퐉 so that the recording layer 2 is formed. It irradiates and heats the irradiated part in this way. The current modulated by the information signal is supplied to the coil 6 on the magnetic head 3 to excite the core 5. At this time, a vertical magnetic field C along the magnetization direction is applied from the main magnetic pole portion 5P of the core 5 near the beam spot b on the recording layer.

However, when information recording is performed using the magnetic head, high heat is generated in the magnetic head due to the material of the core generating the bias magnetic field, that is, due to the high frequency loss peculiar to the magnetic material. Since the heat itself can degrade magnetic properties and other properties, it has a negative effect on the recording layer of the magneto-optical recording medium. Specifically, when the core of the magnetic head is made of polycrystalline Mn-Zn ferrite material, a unique loss occurs when the core is excited at high frequencies. As a result, heat is generated to change the magnetic properties, that is, decrease in permeability and decrease in saturation magnetic flux density, so that sufficient magnetic field strength cannot be applied, and thus, good signal recording cannot be performed. In addition, the magneto-optical recording medium is deformed due to the heat generation, i.e., the negative effect. On the other hand, if the frequency of the information signal is lowered in order to overcome the above problem, the transmission speed of the information signal cannot be increased, and the desired high speed processing cannot be performed.

In addition, in order to obtain sufficient magnetic field strength while using the magnetic head, a relatively high current, that is, a current three to five times the current applied to the magnetic head for a hard disk, must be applied to the coil 6. Therefore, there is a problem that the power consumption of the driving circuit for supplying current to the coil 6 increases. By supplying a large current in this way, the upper limit of the recording frequency is limited in designing the drive circuit for the magnetic head, whereby the recording speed of the information signal cannot be increased.

The present invention has been made in consideration of the above situation, and the magneto-optical recording is configured to specify the material of the core of the magnetic head and to sufficiently increase the magnetic field strength relative to the amplitude of the supply current by using the magnetic anisotropy of the core material. The purpose is to provide the medium.

In order to achieve the above object, the present invention provides an optical magnetic recording medium for recording an information signal by applying a magnetic field modulated based on the information signal to the optical magnetic recording medium by the magnetic head. Using the core as a single crystal ferrite material, the easy magnetization direction based on the magnetic anisotropy of the ferrite single crystal at least in the main magnetic pole portion of the core is perpendicular to the recording layer of the magneto-optical recording medium (i.e., application of magnetic field) Or a magnet is arranged so that the magnetization easy direction based on the magnetic anisotropy of the ferrite single crystal in the winding portion of the core of the excitation coil is substantially coincident with the excitation direction by the excitation coil. .

With the above configuration, in the coil winding portion or the main magnetic pole portion of the core that generates the magnetic field, the crystal orientation (magnetization direction) based on the magnetic anisotropy of the single crystal ferrite material is effective and sufficient to act together with the magnetization by the current flowing through the coil. Generate a magnetic field.

Embodiments of the present invention will be specifically described below with reference to FIGS. 2, 3 (a) and 3 (b). The principal part of the magneto-optical recording medium as shown is the same as the conventional structure as shown in FIG. 1 except for the material characteristics of the magnetic core 5. The same reference numerals are given to the same components as those in FIG. 1, and description thereof will be omitted. The magnetic core 5 according to the present invention is made of a single crystal ferrite material such as MnO.ZnO.Fe ₂ O ₃ . As is known, since the single crystal ferrite material has a special magnetic anisotropy, it can be easily magnetized in a specific crystal orientation (magnetization direction). For example, the single crystal ferrite material used in the present invention is a cubic ferrite material, and by changing the composition ratio, the magnetization easy direction can be selected in any of three directions 100, 110, and 111 of the crystal axis.

In this regard, the sintered ferrite material conventionally used as the magnetic core does not have the magnetic anisotropy as described above.

Crystal axis 100 is a general notation for crystal axes [100], [010], [001], [T00], [0T0], and [00T] in a cubic crystal system, but it does not represent only one direction of the axis. In addition, the crystal axes 110, 111 are the respective notations as defined in the above-mentioned 100.

The core of the single crystal ferrite having the easy magnetization direction in the direction of 100 is produced in the shape as shown in FIG. Comparing the value measured using the core as the magnetic head and the value measured using the conventional core as the magnetic head, a magnetic field having a predetermined intensity can be obtained by a current as low as 15%, and the high frequency loss is It can be reduced by 20% at a frequency of 10 MHz.

The present invention utilizes these features. The first execution requirement for carrying out the present invention is such that the magnetic field direction (magnetic field direction generated by the main magnetic pole portion 5P) applied to the recording layer 2 of the magneto-optical recording medium 1 is approximately the same. In the main magnetic pole portion 5P (the magnetic pole portion opposed to the beam spot b) of the core 5, the magnetization easy direction of the single crystal ferrite material used as the core 5 is arranged. That is, in the embodiment as shown in FIG. 2, the magnetization easy direction of the single crystal ferrite material is shown in the direction of the arrow A, which approximately coincides with the applied magnetic field direction as shown in the direction of the arrow C. . In this case, the magnetic field strength generated by the main station 5P is larger than the case where the above requirement is not satisfied.

Therefore, even if the current supplied to the excitation coil 6 is reduced, a sufficient magnetic field can be generated, whereby the magnetic field can be efficiently applied to the magneto-optical recording medium 1.

The second implementation requirement for carrying out the present invention is that the magnetization of the single crystal ferrite material used as the core 5 in the winding portion of the excitation coil 6 by the excitation coil 6 substantially coincides with the direction of excitation. Easy direction is to arrange. That is, in the embodiment shown in FIG. 2, the excitation direction of the magnetization of the single crystal ferrite material as shown in the direction of arrow A is generated by the excitation coil 6 as shown in the direction of arrow B. FIG. Approximately equal to the direction. In this case, since the high frequency loss of the ferrite single crystal is smaller than the case where the second execution requirement is not satisfied, heat generation of the core 5 is limited.

In this embodiment, since the excitation coil 6 is wound around the main magnetic pole portion 5 of the core, the magnetic field direction (arrow C direction) applied to the recording layer 2 of the magneto-optical recording medium 1. ) Is essentially the same as the excitation direction (arrow (C) direction) by the excitation coil 6. Therefore, both the first and second execution requirements are satisfied simultaneously in this embodiment.

3 (a) and 3 (b) show another embodiment, in which the coil 6 is wound around a part of the core 5 perpendicular to the main magnetic pole portion 5P. In this embodiment, there are two crystal orientations selected. Specifically, as indicated by the solid line of the arrow A, the easy magnetization direction is the same as the direction of the magnetic field applied to the recording layer 2 (arrow C direction), while the excitation direction of the coil 6 It points to the horizontal direction (the dotted arrow B direction) of a winding part, and a magnetic effect is generate | occur | produced in the main magnetic pole part 5P by this. The above configuration satisfies the execution requirement. In contrast, in the case of FIG. 3B, the magnetization direction is selected in the direction of the arrow A in the solid line so as to coincide with the excitation direction (arrow B direction) by the coil 6. This configuration satisfies the second execution requirement. Of course, any of the above cases has the same advantages and advantages as the first embodiment in terms of practical functions.

The excitation coil winding portion or the main magnetic pole portion of the core of the magnetic head will be described below in detail with reference to the composition ratio of an example consisting of a cubic single crystal ferrite containing at least MnO.ZnO.Fe ₂ O ₃ as a main component. 6 shows the relationship between each composition ratio of MnO.ZnO.Fe ₂ O ₃ and the first magnetic anisotropy constant (K ₁ ). (Keizo Ohta, Magnetocrystalline Anisotropy and Magnetic Permeability of Mn-Zn-Fe Ferrites, J. Phys, Soc. Japan Vol. 18 No. 5 P 685, May 1963). In FIG. 6, the region I shows a composition in which the first magnetic anisotropy constant K ₁ is larger than zero. In this region, the magnetization easy direction is the direction of the crystal axis 100. In the region (II), the proportion of Fe ₂ O ₃ is 60% or less and the first magnetic anisotropy constant K ₁ is smaller than zero. In the region II, the magnetic easy direction is the direction of the crystal axis 111.

In the present invention, an example of satisfying the first execution requirement has the following features. The main magnetic pole portion 5P of the core of the magnetic head is a cubic single crystal ferrite containing at least MnO.ZnO.Fe ₂ O ₃ as a main component. The cubic single crystal ferrite has a first magnetic anisotropy constant (K ₁ ) greater than zero at room temperature. The crystal axes 100 of the single crystals are arranged to substantially coincide with the directions of the magnetic field. (In the embodiment as shown in FIG. 3A, the main magnetic pole portion 5P facing the recording medium 1 is indicated by an arrow. It has a magnetizing easy direction arranged in the (A) direction and is approximately coincident with the applied magnetic field direction (C).)

Further, in the present invention, another example of satisfying the first execution requirement has the following features. The main magnetic pole portion of the core of the magnetic head is a cubic single crystal ferrite containing MnO.ZnO.Fe ₂ O ₃ as a main component of at least 60 mol% or less of Fe ₂ O ₃ composition ratio. The cubic single crystal ferrite has a first magnetic anisotropy constant (K ₁ ) of less than zero at room temperature. The crystal axes 111 of the single crystals are arranged to substantially coincide with the directions of the magnetic fields.

Further, in the present invention, an example of satisfying the second execution requirement has the following features. The excitation coil winding portion of the core of the magnetic head is made of cubic single crystal ferrite containing at least MnO.ZnO.Fe ₂ O ₃ as a main component. The cubic single crystal ferrite has a first magnetic anisotropy constant (K ₁ ) greater than zero at room temperature. The crystal axes 100 of the single crystals are arranged to substantially coincide with the excitation direction by the excitation coils. (In the embodiment as shown in FIG. 3 (b), the core has the crystal axes 100, which is the winding of the excitation coil 6). It is the magnetization easy direction aligned in the direction of arrow A to the part, and is substantially coincident with the excitation direction B of the excitation coil 6).

In addition, the present invention has the following features in another work that satisfies the second execution requirement. There is an exciting coil winding component ratio of at least Fe ₂ O ₃ of the magnetic head core is in a cubic single-crystal ferrite containing as a main component 60moℓ% or less _{MnO · ZnO · Fe 2 O 3} . The cubic single crystal ferrite has a first magnetic anisotropy constant (K ₁ ) of less than zero at room temperature. The crystal axes 111 of the single crystals are arranged to substantially coincide with the excitation direction by the excitation coil.

As described above, when the configuration of the first embodiment as shown in FIG. 2 is applied to the present invention, the first and second execution requirements can be satisfied at the same time. It is also the case of the embodiment shown in FIG. 4 and FIG. In the embodiment as shown in FIG. 4, the core of the magnetic head is composed of a combination of core members 5a and 5b, and also a gap 8 made of nonmagnetic material forming a so-called ring head. Has)

In the embodiment as shown in FIG. 5, the core of the magnetic head is composed of a combination of U-shaped core members 5b and 5c and rod-shaped core member 5a and is made of a nonmagnetic material. It has two gaps 8. In these embodiments, a ferrite single crystal having a composition in any of the regions I and II is used as the main magnetic pole portion 5P of the core, and the magnetization easy direction A is recorded as in the above embodiment. Coincides with the magnetic field direction C applied to the medium 1. The core members 5b and 5c are made of the same ferrite single crystal, but may be polycrystalline ferrite used in the conventional example.

The present inventors experimented with the configuration as shown in FIG. 2 using a core having a composition (for example, MnO: 27 mol%, ZnO: 18 mol%, Fe ₂ O ₃ : 55 mol%) in the region (I). Was performed. According to this experiment, the core having the above composition showed a reduction of 20 to 30% of the heating amount by the driving frequency of 5 to 10 MHz when compared to the conventional core using polycrystalline ferrite. When the inductance was the same, it was confirmed that the core of the present invention can obtain a magnetic field having sufficient strength by the driving current as low as about 10%.

The relational diagram (FIG. 6) shown for explaining the above embodiment is an example of a ferrite single crystal. It should be noted that the range occupied by zones I and II may vary depending on production conditions. Therefore, the regions I and II as shown in FIG. 6 do not limit the composition of the present invention in a strict sense.

7 illustrates an ideal embodiment of the present invention. In the most ideal embodiment, as described above, the magnetization easy direction (arrow (A) direction) coincides with the magnetic field application direction (arrow ('C) direction) in the main magnetic pole portion 5P, and the magnetization easy direction (arrow ( A) direction coincides with the excitation direction (arrow 8 direction) by the excitation coil 6, and the magnetization easy direction (arrow A direction) is formed along the magnetic path of the other part of the core 5. . In particular, in a cubic crystal system, there is a crystal axis 100 and an inverted crystal axis 110 perpendicular to the crystal axis. Therefore, such an ideal mode can be achieved by integrally forming a U-shaped core using single crystal ferrite having the easy magnetization direction of the crystal axis 100. Here, the crystal axis 100 is a general notation of crystal axes [100], [010], [001], [T00], [0T0], and [00T] of the cubic crystal system, but it does not represent only one direction. The direction as shown in FIG. 7 is one example.

The above embodiment is an example of the selection of the most preferable crystal orientation for achieving the purpose of generating an efficient magnetic field using the magnetic anisotropy of the single crystal ferrite material and reducing the high frequency loss. The selection method need not be limited to the above example, but the crystal orientation is selected in consideration of the cutting process of the core and the characteristics related to the crystal orientation, that is, the wear characteristics of the magnetic poles when sliding on the magneto-optical recording medium.

With respect to the temperature dependence of the magnetic permeability and examples described below, In this example, the excitation coil winding portion and the main magnetic pole of the magnetic head core portion is at least a cubic crystal ferrite containing as main components _{MnO · ZnO · Fe 2 O 3} .

There are two possible selection methods for the single crystal ferrite and the easy direction of magnetization of the single crystal ferrite.

In the first case, the ferrite single crystal has a temperature dependence of permeability such that the permeability of the first peak appears at a temperature of room temperature or more, the permeability of the second peak appears at a temperature of room temperature or less, and the crystal axis 100 has a temperature permeability of the magnetization direction. have. The above description will be described with reference to FIG. 8 shows an example of the temperature dependence of the permeability of single crystal ferrite. Permeability curves generally have two extreme maxima, one of which is on the high side and the other on the low side. The former is called the first peak, and the latter is called the second peak. An example as shown in FIG. 8 has a first peak at a temperature above room temperature and a second peak at a temperature below room temperature.

By main components (Fe ₂ O ₃₎ ratio is chosen to be appropriate for a composition ratio of MnO · ZnO · Fe ₂ O ₃ to the extent of at least 50moℓ%, it is possible to generate the single-crystal ferrite.

In the single crystal ferrite, the crystal axis 100 is easy to magnetize at room temperature. It has been confirmed by experiment that if at least one of the two execution requirements as described with reference to FIG. 2 is satisfied, the advantages and features of the present invention can be sufficiently obtained.

In addition, room temperature is 20 degreeC normally. In consideration of the change in the ambient temperature in the magneto-optical recording apparatus, it is preferable to use single crystal ferrite having a first peak at a temperature of 60 ° C or more and a second peak at a temperature of 0 ° C or less.

In the second selection method of the single crystal ferrite and the easy direction of magnetization of the single crystal ferrite, the single crystal has a temperature dependency in which both the magnetic permeability of the first peak and the magnetic permeability of the second peak are at a temperature higher than or equal to room temperature. It has a temperature dependence of permeability. The above description will be described with reference to FIG. 9 shows another example of the temperature dependence of the permeability of single crystal ferrite. In one example as shown in FIG. 9, the permeability curve has two local maxima, and there are first and second peaks as in the above example. The two peaks are located at temperatures above room temperature. By main components (Fe ₂ O ₃₎ ratio is chosen to be appropriate for a composition ratio of MnO · ZnO · Fe ₂ O ₃ to the extent of less than 60moℓ%, it is possible to generate the single-crystal ferrite.

In the single crystal ferrite, the crystal axis 111 becomes easy to magnetize at room temperature.

It has been found by experiment that if at least one of the two execution requirements described with reference to FIG. 2 is satisfied, the advantages and features of the present invention can be sufficiently obtained. As described above, assuming that the room temperature is typically 20 ° C., and considering the change of the ambient temperature in the magneto-optical recording medium, it is preferable to use single crystal ferrite having a first peak and a second peak at a temperature of 60 ° C. or higher. .

An example of the first structure that satisfies the first execution requirement as described with reference to FIG. 2 will be described below using FIG. The single crystal ferrite forming the core 5 as shown in FIG. 2 has a temperature dependency of permeability as shown in FIG. Specifically, single crystal ferrite is selected to have a permeability of the first peak at temperatures above room temperature and a permeability of the second peak at temperatures below room temperature. In addition, in the main magnetic pole portion 5P facing at least the recording layer 2 for applying the magnetic field, the main magnetic pole portion 5P is aligned in the direction of the arrow A in FIG. 2 and indicated by the arrow C. The crystal axis 100 is arranged so as to substantially coincide with the direction of the magnetic field generated by the photoelectric field and applied to the recording layer 2.

A second structure of another example that satisfies the first execution requirement as described with reference to FIG. 2 will be described below. In the second structure, the single crystal ferrite forming the core 5 has the temperature dependency of permeability as shown in FIG.

Specifically, single crystal ferrite is selected to have a permeability of the first and second peaks at temperatures above room temperature. In the main magnetic pole portion 5P facing at least the recording layer 2 in order to apply the magnetic field, the main magnetic pole portion 5P is aligned in the direction of the arrow A in FIG. 2 and is applied to the main magnetic pole portion 5P as indicated by the arrow C. FIG. The crystal axes 111 are arranged so as to substantially coincide with the direction of the magnetic field generated and applied to the recording layer 2.

A first structure that satisfies the second execution requirement as described with reference to FIG. 2 will now be described. The single crystal ferrite forming the core 5 as shown in FIG. 2 has a temperature dependency of permeability as shown in FIG. Specifically, single crystal ferrite has a permeability of the first peak at a temperature above room temperature and a permeability of a second peak at a temperature below room temperature. In addition, at least in the winding portion of the excitation coil 6, aligned in the direction of the arrow A in FIG. 2, the excitation direction generated by the excitation coil 6 of the core 5, as indicated by the arrow B. FIG. The crystal axis 111 is arranged to approximately coincide with.

In the present embodiment, since the excitation coil 6 is arranged so as to be directly wound around the main magnetic pole portion 5P of the core 5, both of the first and second execution requirements are satisfied at the same time. .

In the ferrite single crystal, there is always one crystal axis 100 and an inverted crystal axis 100 perpendicular to the crystal axis. Therefore, when the core is formed as in this embodiment, the crystal axis 100 can be aligned in the direction of arrow D, which is perpendicular to the direction of arrow A, and in the direction of arrow A as shown in the figure. In this way, since most of the magnetic field paths can be aligned along the direction of the crystal axis 100, a maximum effect can be obtained.

An example in which the winding portion of the excitation coil 6 does not coincide with the main magnetic pole portion 5P of the core 5 will be described below with reference to FIGS. 3A and 3B. 3A shows a first structure that satisfies the first execution requirement. In the first structure, the single crystal ferrite forming the core 5 has a temperature dependency of permeability as shown in FIG.

Specifically, single crystal ferrite has a permeability of the first peak at temperatures above room temperature and a permeability of the second peak at temperatures below room temperature. In addition, in the main magnetic pole portion 5P facing at least the recording layer 2 for applying the magnetic field, the main magnetic pole portion, as shown by the arrow C, aligned in the direction of the arrow A shown in the drawing. The crystal axes 100 are arranged so as to substantially coincide with the magnetic field direction generated by 5P and applied to the recording layer 2.

A second structure that satisfies the first execution requirement will be described below. In this case, the single crystal ferrite forming the core 5 has a temperature dependency of permeability, as shown in FIG. Specifically, the single crystal ferrite is selected to have both a permeability of the first peak and a permeability of the second peak at temperatures above room temperature. Further, in order to apply the magnetic field, at least in the main magnetic pole portion 5P facing the recording layer 2, the main magnetic pole portion 5P is aligned in the direction of the arrow A as shown in the figure, and as shown by the arrow C, the main The crystal axis 111 is arranged so as to substantially coincide with the magnetic field direction generated by the magnetic pole portion 5P and applied to the recording layer 2.

FIG. 3B shows a first structure that satisfies the second execution requirement. In the first structure, the single crystal ferrite forming the core 5 has a temperature dependency of permeability as shown in FIG. Specifically, the single crystal ferrite is selected to have a permeability of the first peak at temperatures above room temperature and a permeability of the second peak at temperatures below room temperature. In addition, at least in the winding portion of the excitation coil 6, aligned in the direction of arrow A as shown in the figure, as shown by arrow B, excitation generated by the excitation coil of the core 5. The crystal axis 100 is arranged so as to substantially coincide with the direction.

A second structure that satisfies the second execution requirement will now be described. In this case, the single crystal ferrite forming the core 5 has the temperature dependency of permeability as shown in FIG. Specifically, the single crystal ferrite is selected to have both a permeability of the first peak and a permeability of the second peak at temperatures above room temperature. In addition, at least in the winding portion of the excitation coil 6, aligned in the direction of the arrow A as shown in the figure, as shown by the arrow B, by the excitation coil 6 of the core 5. The crystal axes 111 are arranged to substantially coincide with the generated excitation direction.

In these examples, since the winding portions of the excitation coil 6 do not coincide with the main magnetic pole portion 5P of the core 5, the first and second execution requirements cannot be satisfied at the same time, but at least among the above requirements. Sufficient effect can be obtained to satisfy either.

In addition, the whole core 5 does not necessarily need to be formed of integral single crystal ferrite. The core 5 may be composed of two or more members, and only essential members or essential members may be formed of single crystal ferrite.

In addition, the shape of the core is not limited to the U shape. For example, as shown in FIG. 4, the core is formed by a combination of two core members 5a, 5b having a non-magnetic material formed gap 8, which is a so-called ring head. Further, as shown in FIG. 5, the magnetic head may be formed by the core member 5a having two coil members 5b on both sides with two gaps 8. In these embodiments, in order to satisfy the first execution requirement, the core member 5a including the main magnetic pole portion 5P is a ferrite single crystal having a temperature dependency of permeability as shown in FIG. have.

As shown in the figure, the crystal axes are aligned in the direction of the arrow A, as shown by the arrow C, so as to substantially match the direction of the magnetic field generated by the main magnetic pole portion 5P and applied to the recording layer 2. Arrange 100. Alternatively, the core member 5a is a ferrite single crystal having a temperature dependency of permeability, as shown in FIG. The crystal axis is aligned in the direction of the arrow A as shown in the figure, and substantially coincides with the magnetic field direction generated by the main magnetic pole portion 5P and applied to the recording layer 2, as shown by the arrow C. FIG. Arrange 111.

In this embodiment, since the excitation coil 6 is wound directly around the main magnetic pole portion 5P, the direction of the arrow A coincides with the excitation direction as shown by the arrow B, and thus the second execution. Can satisfy the requirements.

By the configuration as in the above embodiment, the magnetic head of the present invention can generate a magnetic field having a greater intensity than a conventional apparatus, and can apply a sufficient magnetic field to the magneto-optical recording medium even if the supply current of the excitation coil is reduced, The power consumption of the drive circuit of the magnetic head can be reduced. In addition, since the upper limit of the recording frequency can be set higher than that of the conventional apparatus, the recording speed of the information signal by the magnetic head can be increased.

In addition, by limiting the frequency loss of the core, it is possible to prevent changes in magnetic properties, that is, decrease in permeability due to heat generation and reduction in saturation magnetic flux density. In addition, it is possible to prevent negative effects due to heat generation, that is, deformation of the magneto-optical recording medium.

When the crystal axis 100 is aligned in the direction of the arrow A and a ferrite single crystal having a temperature dependency of magnetic permeability as shown in FIG. 8 is shown for the magnetic head formed as shown in FIG. Compared to the conventional example used, 20-30% is reduced at the driving frequency of 5-10MHZ, and when the inductance is kept the same, the experiment shows that sufficient magnetic field can be generated while the driving current is reduced by about 10%. Confirmed.

The present invention has been described in detail as described above. In the magneto-optical recording apparatus in which information recording is performed by applying a magnetic field to the magneto-optical recording medium by the magnetic head according to the present invention, the magnetic head is formed of a core made of single crystal ferrite material, and the crystal orientation of the single crystal ferrite material is At the time of recording, the cores are arranged so that the coil windings of the core have a direction characteristic that is easily magnetized in the same direction as the exciting direction of the coil, or the crystal orientation has the same direction characteristic as the magnetic field application direction of the main magnetic pole part. Therefore, the low magnetic current sufficiently applies a perpendicular magnetic field to the recording layer of the magneto-optical recording medium, thereby reducing the power consumption of the electric circuit for supplying current to the coil. In addition, the high frequency loss of the magnetic head is reduced, there is no heat generation, and negative effects such as deterioration of magnetic lock or other characteristics can be overcome in the magnetic head itself, and negative effects on the recording medium can be overcome.

Therefore, the power supply can be performed even at a high frequency, so that a good effect, i.e., an increase in information transfer speed, can be achieved.

Claims (36)

An optical head for irradiating a light beam onto the magneto-optical recording medium, A magneto-optical recording apparatus comprising a magnetic head for applying a magnetic field to the magneto-optical recording medium, The core of the magnetic head is made of a single crystal ferrite material, It is arranged that the easy magnetization direction based on the magnetic anisotropy of the single crystal ferrite material constituting the main magnetic pole portion of the core of the magnetic head is substantially coincident with the magnetic field direction applied to the magneto-optical recording medium. Magneto-optical recording device characterized in that. The method of claim 1, The excitation coil winding portion of the core of the magnetic head is made of a cubic single crystal ferrite containing at least MnO.ZnO.Fe ₂ O ₃ as a main component. The cubic single crystal ferrite has a first magnetic anisotropy constant K ₁ greater than zero at room temperature and has a crystal axis 100 substantially coincident with the excitation direction generated by the excitation coil wound around the winding part. Magneto-optical recording device, characterized in that. The method of claim 1, Women of said core of said magnetic head coil winding is made of a cubic single-crystal ferrite of the composition ratio of Fe ₂ O ₃ containing at least as a main component 60moℓ% or less _{MnO · ZnO · Fe 2 O 3} , The cubic single crystal ferrite has a first magnetic anisotropy constant K ₁ of less than zero at room temperature, and has a crystal axis 111 substantially coincident with the excitation direction generated by the excitation coil wound around the winding part. Magneto-optical recording device, characterized in that. The method of claim 1, Permeability in which the main magnetic pole portion of the core of the magnetic head contains at least MnO.ZnO.Fe ₂ O ₃ as a main component and exhibits a permeability of the first peak at a temperature above room temperature and a permeability of a second peak at a temperature below room temperature. It consists of cubic single crystal ferrite having a temperature dependency of The cubic single crystal ferrite has a crystal axis 100 substantially coincident with the magnetic field direction. Magneto-optical recording device, characterized in that. The method of claim 1, Permeability of the magnetic coil winding portion of the core of the magnetic head contains at least MnO.ZnO.Fe ₂ O ₃ as a main component, and the permeability of the first peak appears at temperatures above room temperature and the permeability of the second peak at temperatures below room temperature. It consists of cubic single crystal ferrite having a temperature dependency of The cubic single crystal ferrite has a crystal axis 100 substantially coincident with the excitation direction of the excitation coil winding part. Magneto-optical recording device, characterized in that. The method of claim 1, The main magnetic pole portion of the core of the magnetic head contains at least MnO.ZnO.Fe ₂ O ₃ as a main component and has a temperature dependency of permeability in which both the permeability of the first peak and the permeability of the second peak appear at temperatures above room temperature. Made of cubic single crystal ferrite, The cubic single crystal ferrite has a crystal axis 111 substantially coincident with the magnetic field direction. Magneto-optical recording device, characterized in that. The method of claim 1, The excitation coil winding portion of the core of the magnetic head contains at least MnO.ZnO.Fe ₂ O ₃ as a main component and has a temperature dependence of permeability at which both the permeability of the first peak and the permeability of the second peak appear at temperatures above room temperature. Made of cubic single crystal ferrite, The cubic single crystal ferrite has a crystal axis 111 substantially coincident with the excitation direction of the excitation coil winding part. Magneto-optical recording device, characterized in that. The method of claim 1, The main magnetic pole portion of the core of the magnetic head contains at least MnO.ZnO.Fe ₂ O ₃ as a main component and has a temperature dependency of permeability in which both the permeability of the first peak and the permeability of the second peak appear at temperatures above room temperature. Made of cubic single crystal ferrite, The cubic single crystal ferrite has a crystal axis 111 substantially coincident with the magnetic field direction. Magneto-optical recording device, characterized in that. The method of claim 1, The excitation coil winding portion of the core of the magnetic head contains at least MnO.ZnO.Fe ₂ O ₃ as a main component and has a temperature dependence of permeability at which both the permeability of the first peak and the permeability of the second peak appear at temperatures above room temperature. Made of cubic single crystal ferrite, The cubic single crystal ferrite has a crystal axis 111 substantially coincident with the excitation direction of the excitation coil winding part. Magneto-optical recording device, characterized in that. A magneto-optical recording apparatus comprising a magnetic head for applying a magnetic field to a magneto-optical recording medium, and applying a magnetic field to the magneto-optical recording medium, The core of the magnetic head is made of a single crystal ferrite material, The magnetization easy direction based on the magnetic anisotropy of the single crystal ferrite material constituting the main magnetic pole portion of the core of the magnetic head is arranged so as to substantially coincide with the magnetic field direction applied to the magneto-optical recording medium. Magneto-optical recording device, characterized in that. The method of claim 10, The main magnetic pole portion of the core of the magnetic head is composed of cubic single crystal ferrite containing at least MnO.ZnO.Fe ₂ O ₃ as a main component, The cubic single crystal ferrite has a first magnetic anisotropy constant K ₁ greater than zero at room temperature and has a crystal axis 100 substantially coincident with the magnetic field direction. The method of claim 10, Wherein the main pole of the core portion is at least a ratio of Fe ₂ O ₃ less than 60moℓ% of the magnetic head is made of a cubic single-crystal ferrite comprising as main components _{MnO · ZnO · Fe 2 O 3} , The cubic single crystal ferrite has a first magnetic anisotropy constant K ₁ of less than zero at room temperature, and has a crystal axis 111 substantially coincident with the magnetic field direction. Magneto-optical recording device, characterized in that. The method of claim 10, The excitation coil winding portion of the core of the magnetic head is made of a cubic single crystal ferrite containing at least MnO.ZnO.Fe ₂ O ₃ as a main component. The cubic single crystal ferrite has a first magnetic anisotropy constant K ₁ which is less than zero at room temperature, and has a crystal axis 100 substantially coincident with the excitation direction generated by the excitation coil wound around the winding part. Magneto-optical recording device, characterized in that. The method of claim 10, Women of said core of said magnetic head coil winding is made of a cubic single-crystal ferrite of the composition ratio of Fe ₂ O ₃ containing at least as a main component 60moℓ% or less _{MnO · ZnO · Fe 2 O 3} , The cubic single crystal ferrite has a first magnetic anisotropy constant K ₁ which is less than zero at room temperature, and has a crystal axis 111 substantially coincident with the excitation direction generated by the excitation coil wound around the winding part. Magneto-optical recording device, characterized in that. The method of claim 10, The main magnetic pole portion of the core of the magnetic head contains at least MnO.ZnO.Fe ₂ O ₃ as a main component and exhibits a permeability of the first peak at a temperature above room temperature and a permeability of a second peak at a temperature below room temperature. It consists of cubic single crystal ferrite having temperature dependence of permeability, The cubic single crystal ferrite has a crystal axis 100 substantially coincident with the magnetic field direction. Magneto-optical recording device, characterized in that. The method of claim 10, Permeability of the magnetic coil winding portion of the core of the magnetic head contains at least MnO.ZnO.Fe ₂ O ₃ as a main component, and the permeability of the first peak appears at temperatures above room temperature and the permeability of the second peak at temperatures below room temperature. It consists of cubic single crystal ferrite having a temperature dependency of The cubic single crystal ferrite has a crystal axis 100 substantially coincident with the excitation direction of the excitation coil winding part. Magneto-optical recording device, characterized in that. The method of claim 10, The main magnetic pole portion of the core of the magnetic head contains at least MnO.ZnO.Fe ₂ O ₃ as a main component and has a temperature dependence of permeability at which both the permeability of the first peak and the permeability of the second peak appear at temperatures above room temperature. Made of cubic single crystal ferrite, The cubic single crystal ferrite has a crystal axis 111 substantially coincident with the magnetic field direction. Magneto-optical recording device, characterized in that. The method of claim 10, The excitation coil winding portion of the core of the magnetic head contains at least MnO.ZnO.Fe ₂ O ₃ as a main component and has a temperature dependence of permeability at which both the permeability of the first peak and the permeability of the second peak appear at temperatures above room temperature. Made of cubic single crystal ferrite, The cubic single crystal ferrite has a crystal axis 111 substantially coincident with the excitation direction of the excitation coil winding part. Magneto-optical recording device, characterized in that. An optical head for irradiating a light beam onto the magneto-optical recording medium, A magneto-optical recording apparatus comprising a magnetic head for applying a magnetic field to the magneto-optical recording medium, The core of the magnetic head is made of a single crystal ferrite material, The magnetization easy direction based on the magnetic anisotropy of the single crystal ferrite material constituting the core is arranged so as to substantially coincide with the magnetization direction generated by the coil of the coil winding of the core of the magnetic head. Magneto-optical recording device, characterized in that. The method of claim 19, The main magnetic pole portion of the core of the magnetic head contains at least MnO.ZnO.Fe ₂ O ₃ as a main component and consists of cubic single crystal ferrite, The cubic single crystal ferrite has a first magnetic anisotropy constant K ₁ greater than zero at room temperature and has a crystal axis 100 substantially coincident with the magnetic field direction. Magneto-optical recording device, characterized in that. The method of claim 19, The main magnetic pole portion of the core of the magnetic head is made of cubic single crystal ferrite containing at least Fe ₂ O ₃ as a main component of MnO.ZnO.Fe ₂ O ₃ having a composition ratio of 60 mol% or less, The cubic single crystal ferrite has a first magnetic anisotropy constant K ₁ of less than zero at room temperature and has a crystal axis 111 substantially coincident with the magnetic field direction. Magneto-optical recording device, characterized in that. The method of claim 19, The excitation coil winding portion of the core of the magnetic head contains at least MnO.ZnO.Fe ₂ O ₃ as a main component and consists of cubic single crystal ferrite, The cubic single crystal ferrite has a first magnetic anisotropy constant K ₁ greater than zero at room temperature, and has a crystal axis 100 substantially coincident with the excitation direction generated by the excitation coil wound around the winding part. Magneto-optical recording device, characterized in that. The method of claim 19, Women of said core of said magnetic head coil winding is made of a cubic single-crystal ferrite of the composition ratio of Fe ₂ O ₃ containing at least as a main component 60moℓ% or less _{MnO · ZnO · Fe 2 O 3} , The cubic single crystal ferrite has a first magnetic anisotropy constant K ₁ which is less than zero at room temperature, and has a crystal axis 111 substantially coincident with the excitation direction generated by the excitation coil wound around the winding part. Magneto-optical recording device, characterized in that. The method of claim 19, The main magnetic pole portion of the core of the magnetic head contains at least MnO.ZnO.Fe ₂ O ₃ as a main component and exhibits a permeability of the first peak at a temperature above room temperature and a permeability of a second peak at a temperature below room temperature. It consists of cubic single crystal ferrite having temperature dependence of permeability, The cubic single crystal ferrite has a crystal axis 100 substantially coincident with the magnetic field direction. Magneto-optical recording device, characterized in that. The method of claim 19, Permeability of the magnetic coil winding portion of the core of the magnetic head contains at least MnO.ZnO.Fe ₂ O ₃ as a main component, and the permeability of the first peak appears at temperatures above room temperature and the permeability of the second peak at temperatures below room temperature. It consists of cubic single crystal ferrite having a temperature dependency of The cubic single crystal ferrite has a crystal axis 100 substantially coincident with the excitation direction of the excitation coil winding part. Magneto-optical recording device, characterized in that. The method of claim 19, The main magnetic pole portion of the core of the magnetic head contains at least MnO.ZnO.Fe ₂ O ₃ as a main component and has a temperature dependence of permeability at which both the permeability of the first peak and the permeability of the second peak appear at temperatures above room temperature. Made of cubic single crystal ferrite, The cubic single crystal ferrite has a crystal axis 111 substantially coincident with the magnetic field direction. Magneto-optical recording device, characterized in that. The method of claim 19, The excitation coil winding portion of the core of the magnetic head contains at least MnO.ZnO.Fe ₂ O ₃ as a main component and has a temperature dependence of permeability at which both the permeability of the first peak and the permeability of the second peak appear at temperatures above room temperature. Made of cubic single crystal ferrite, The cubic single crystal ferrite has a crystal axis 111 substantially coincident with the excitation direction of the excitation coil winding part. Magneto-optical recording device, characterized in that. A magneto-optical recording apparatus comprising a magnetic head for applying a magnetic field to a magneto-optical recording medium, and applying a magnetic field to the magneto-optical recording medium, The core of the magnetic head is made of a single crystal ferrite material, The magnetization easy direction based on the magnetic anisotropy of the single crystal ferrite material constituting the core is arranged so as to substantially coincide with the magnetization direction generated by the coil of the coil winding of the core of the magnetic head. Magneto-optical recording device, characterized in that. The method of claim 28, The main magnetic pole portion of the core of the magnetic head contains at least MnO.ZnO.Fe ₂ O ₃ as a main component and consists of cubic single crystal ferrite, The cubic single crystal ferrite has a first magnetic anisotropy constant K ₁ greater than zero at room temperature and has a crystal axis 100 substantially coincident with the magnetic field direction. Magneto-optical recording device, characterized in that. The method of claim 28, The main magnetic pole portion of the core of the magnetic head consists of a cubic single crystal ferrite containing at least Fe ₂ O ₃ as a main component of MnO.ZnO.Fe ₂ O ₃ having a composition ratio of 60 mol% or less, The cubic single crystal ferrite has a first magnetic anisotropy constant K ₁ of less than zero at room temperature, and has a crystal axis 111 substantially coincident with the magnetic field direction. Magneto-optical recording device, characterized in that. The method of claim 28, The excitation coil winding portion of the core of the magnetic head is made of a cubic single crystal ferrite containing at least MnO.ZnO.Fe ₂ O ₃ as a main component. The cubic single crystal ferrite has a first magnetic anisotropy constant K ₁ greater than zero at room temperature, and has a crystal axis 100 substantially coincident with the excitation direction generated by the excitation coil wound around the winding part. Magneto-optical recording device, characterized in that. The method of claim 28, Women of said core of said magnetic head coil winding is made of a cubic single-crystal ferrite of the composition ratio of Fe ₂ O ₃ containing at least as a main component 60moℓ% or less _{MnO · ZnO · Fe 2 O 3} , The cubic single crystal ferrite has a first magnetic anisotropy constant K ₁ which is less than zero at room temperature, and has a crystal axis 111 approximately equal to the excitation direction generated by the excitation coil wound around the winding part. Magneto-optical recording device, characterized in that. The method of claim 28, The main magnetic pole portion of the core of the magnetic head contains at least MnO.ZnO.Fe ₂ O ₃ as a main component and exhibits a permeability of the first peak at a temperature above room temperature and a permeability of a second peak at a temperature below room temperature. It consists of cubic single crystal ferrite having temperature dependence of permeability, The cubic single crystal ferrite has a crystal axis 100 substantially coincident with the magnetic field direction. Magneto-optical recording device, characterized in that. The method of claim 28, The excitation coil winding part of the core of the magnetic head At least MnOZnOFe₂O₃It is composed of a cubic single crystal ferrite containing as a main component and having a temperature permeability of the magnetic permeability at which the permeability of the first peak appears at a temperature above room temperature and the permeability of the second peak at a temperature below room temperature. The cubic single crystal ferrite has a crystal axis 100 substantially coincident with the excitation direction of the excitation coil winding part. Magneto-optical recording device, characterized in that. The method of claim 28, The main magnetic pole portion of the core of the magnetic head contains at least MnO.ZnO.Fe ₂ O ₃ as a main component and has a temperature dependency of permeability in which both the permeability of the first peak and the permeability of the second peak appear at temperatures above room temperature. Made of cubic single crystal ferrite, The cubic single crystal ferrite has a crystal axis 111 substantially coincident with the magnetic field direction. Magneto-optical recording device, characterized in that. The method of claim 28, The excitation coil winding portion of the core of the magnetic head contains at least MnO.ZnO.Fe ₂ O ₃ as a main component and has a temperature dependence of permeability at which both the permeability of the first peak and the permeability of the second peak appear at temperatures above room temperature. Made of cubic single crystal ferrite, The cubic single crystal ferrite has a crystal axis 111 substantially coincident with the excitation direction of the excitation coil winding part. Magneto-optical recording device, characterized in that.