JPH06176429A - Magnetic head for magneto-optical recording and magneto-optical recording device - Google Patents

Abstract

PURPOSE:To prevent the degradation in magnetic field generation efficiency by forming a magnetic material constituting a core of an Mn-Zn ferrite having >=140 deg.C Curie temp., >=200 magnetic permeability and >=4400G effective saturation magnetic flux density. CONSTITUTION:This magnetic head is formed by using the ferrite (Mn-Zn ferrite) consisting essentially of Fe2O3, MnO and ZnO having >=140 deg.C Curie temp. and >=4400G effective saturation magnetic flux density at 25 deg.C. For example, a good result is obtd. if the end face 25a of the main magnetic pole of the core 25 is formed square and the size P1 in the radial direction of the disk is set slightly larger than the size P2 in the tangent direction of recording tracks. As a result, the deviation of the light spot from right below the main magnetic pole is prevented by the tracking action of the light spot for the eccentricity of the recording tracks, by which the degradation in the efficiency of generating the magnetic field is prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magneto-optical recording magnetic head and a magneto-optical recording device for recording an information signal on a magneto-optical recording medium by a magnetic field modulation method.

[0002]

2. Description of the Related Art As a magneto-optical recording device for recording information on a magneto-optical recording medium such as a magneto-optical disk with a high density, there is known a magneto-optical recording system. In this method, a recording medium is irradiated with a laser beam focused on a light spot having a diameter of about 1 μm, while a magnetic head applies a magnetic field modulated by an information signal to the irradiated portion of the laser beam. To record the information signal.

A generally known magnetic field modulation type magneto-optical recording apparatus has a structure as shown in FIG. The magneto-optical recording medium 31 used here is disk-shaped and has a structure in which a signal recording layer is formed on a transparent substrate. The disk 31 is rotated by a spindle motor 30. At this time, the floating magnetic head 20 is on the upper surface side of the disk 31, and the magnetic head 20 is on the lower surface side.
The optical head 21 is arranged to face each other. The magnetic head 20 is held at the tip of a suspension 23, and the optical head 21 and the fixed end of the suspension 23 are connected to each other by a connecting member 22 to form a magneto-optical unit. The connecting member 22 is attached to the linear motor 24. Therefore, by driving the linear motor 22, the optical head 21 and the magnetic head 20 are integrally moved to the radial direction of the disk 31. ing.

In the magnetic field modulation type magneto-optical recording apparatus, when an information signal is recorded on the disc 31, the laser beam 26 is emitted from the optical head 21 while the disc 31 is rotated at a high speed by the spindle motor 30. The signal recording layer of the disc 31 is irradiated with the light and imaged as a light spot 26s having a diameter of about 1 μm. As a result, the temperature of the signal recording layer rises above the Curie temperature. At the same time, a bias magnetic field modulated by the magnetic head 20 according to an information signal is applied to the temperature rising portion. As a result, the direction of magnetization of the signal recording layer faces the direction of the bias magnetic field, and the information signal is recorded on the signal recording layer.

In the magnetic head 20, the slider 28 is made of a non-magnetic material, such as ceramic, as shown in FIG. 5 as a whole perspective view, FIGS. 2 (a) and 2 (b) as a partial sectional view and a bottom view. And a U-shaped core 25 made of a magnetic material having a high magnetic permeability, for example, ferrite, at the end thereof.
Is a composite type in which the open end of the core 25 is directed to the bottom surface of the slider, and one leg of the core 25 is used as a main magnetic pole 25b to form a coil 27.
Is wound and a current modulated by an information signal by a drive circuit (not shown) is supplied to the magnetic pole end surface 25.
A perpendicular magnetic field B directed from a toward the recording medium is generated.

However, since the strength of the magnetic field generated from the magnetic pole end surface 25a is sufficiently large and uniform only just below the magnetic pole end surface 25a, the laser light 26 from the optical head 21 is directly below the magnetic pole end surface 25a. If the image is not formed as the light spot 26s on the recording medium, a magnetic field having an intensity necessary for recording the information signal is not applied, and normal signal recording cannot be performed.

Therefore, in the conventional magneto-optical recording apparatus, due to the limits of the dimensional accuracy obtained in manufacturing and the mechanical positional accuracy at the time of assembly of the magnetic head, the optical head, and the connecting member connecting the two, The maximum allowable error between the magnetic pole end surface 25a of the magnetic head and the light spot is ±
In order to reach 0.15 mm, the size of the magnetic pole end surface 25a is substantially 0.4 mm in consideration of other error factors.
By setting the size to be approximately 0.4 mm to 0.6 mm x 0.6 mm, the light spot was reliably positioned immediately below the magnetic pole end surface 25a.

[0008]

However, in recent years,
In information recording devices such as magneto-optical recording devices, there is an increasing demand for higher density information signal recording and higher information signal transfer speed, and in response to this, the maximum frequency of recorded information signals is increased to about 10 MHz. There is a need. However, as described above, conventionally, it was difficult to make the magnetic pole end face sufficiently small due to the problem of the positioning accuracy between the magnetic head and the light spot.

Generally, the inductance of the coil is approximately proportional to the cross-sectional area of the magnetic pole, and is also proportional to the square of the number of turns. Thus, the magnetic pole end surface is 0.4 mm × 0.4 m.
When it is as large as m to 0.6 mm × 0.6 mm, the inductance is as large as 3 μH or more. When supplying a high frequency current to a magnetic head having a large inductance, it is necessary to apply a very large voltage, which increases the power consumption of the drive circuit. Therefore, in practice, the maximum frequency of the recorded information signal is about 5 MHz. It will remain.

Further, when the number of turns of the coil is reduced in order to reduce the inductance, it is necessary to increase the amount of supplied current accordingly. Again, this is also practical considering the power consumption of the drive circuit. Not a means.

On the other hand, the present applicant uses, for example, the "positioning device for the magnetic head" described in the specification of Japanese Patent Application No. 3-2034014 to position the main magnetic pole end surface of the magnetic head and the light spot. We have already established a method that can increase the accuracy to about ± 0.01 mm. As a result, even if the end surface of the main magnetic pole has a size of about 0.1 mm × 0.1 mm, positioning with the light spot is possible.

However, for example, in comparison with the conventional example of FIG.
As shown in FIG. 3, a simple improvement of the main magnetic pole 25b (for example, 0.1 mm × 0.1 mm) causes the following adverse effects, and therefore a sufficient effect is still obtained. I can't.

First, of the magnetic flux generated in the main magnetic pole 25b, the ratio of the magnetic flux B'leaked from the side surface of the main magnetic pole 25b is relatively increased, while the magnetic pole end surface 2 of the main magnetic pole 25b is increased.
Effective magnetic flux (magnetic field) applied to the disk 31 from 5a
Since B is relatively reduced, the magnetic field generation efficiency of the magnetic head is reduced. To supplement this, it is necessary to supply an excessive current to the coil 27 in order to apply a sufficient magnetic field to the disk 31, which becomes a burden on the magnetic head drive circuit.

Secondly, as described above, when a sufficient magnetic field is applied to the disk 31 in order to supplement the decrease in the magnetic field generation efficiency of the magnetic head, the magnetic flux density is increased by the excessive magnetic flux in the main pole. As the magnetic flux is increased, saturation of magnetic flux easily occurs in the main magnetic pole, and it becomes difficult to apply a sufficient magnetic field to the disk 31.

Thirdly, since the main magnetic pole becomes thin, the mechanical strength becomes insufficient, and the core 25 is likely to be damaged during manufacture or use.

[0016]

The present invention has been made for the purpose of solving the problems in the magnetic head for magneto-optical recording as described above, and the magnetic head constitutes the core thereof. As a magnetic material, the Curie temperature is 1
A frequency of 8MHz at a temperature of 25 ° C and 40 ° C or higher
Permeability is 200 or more, the effective saturation magnetic flux density at a temperature of 25 ° C. is 4400 G or more, and Fe ₂ O
_3, MnO, ferrite mainly composed of ZnO (Mn-
It is characterized by using Zn ferrite).

Further, desirably, as the material of the core, Mn-Zn ferrite having a Curie temperature of 170 ° C. or higher, a permeability of 200 MHz or higher at a frequency of 10 MHz and an effective saturation magnetic flux density of 5000 G or higher at a temperature of 25 ° C. Or the Curie temperature is 200 ° C. or higher, and the magnetic permeability at a frequency of 12 MHz is 200 at a temperature of 25 ° C.
As described above, Mn- whose effective saturation magnetic flux density is 5500 G or more
It is characterized by using Zn ferrite.

Furthermore, the core, the area of the main magnetic pole end face 0.01 mm ² or more, 0.039 mm ² or less, the area of the winding window of coil 0.11 mm ² or more, 0.47 mm
^The characteristic is that the distance between the main magnetic pole end surface and the coil is set to 2 mm or less and 0.05 mm or more and 0.29 mm or less.

Further, the coil is formed by winding a wire having a conductor cross-sectional area of 7 × 10 ^-4 mm ² or more and 5 × 10 ^-3 mm ² or less, and its inductance is 0.4 μm.
It is characterized by being set to H or more and 2 μH or less.

Further, the magneto-optical recording device of the present invention is
The maximum frequency of the recording signal is approximately 8 MHz or higher, and as described above, a magnetic head made of Mn-Zn ferrite having a Curie temperature of 140 ° C. or higher and an effective saturation magnetic flux density of 4400 G or higher is mounted. Is a magnetic head made of Mn-Zn ferrite having a maximum frequency of a recording signal of about 10 MHz or more, a Curie temperature of 170 ° C. or more, and an effective saturation magnetic flux density of 5000 G or more.

Further, in the magneto-optical recording apparatus of the present invention, it is desirable that the maximum frequency of the recording signal be approximately 12 MHz or higher, the Curie temperature is 200 ° C. or higher, and the effective saturation magnetic flux density is 5500 G or higher. It is equipped with a magnetic head.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A magnetic head for magneto-optical recording according to the present invention will be described in detail below with reference to the drawings. Figure 1
FIG. 3 is an enlarged view of the periphery of the core 25 of the magnetic head for magneto-optical recording according to the present invention. FIG.
(B) is the bottom view. Next, the dimensions of each part of the core 25 in this embodiment will be described. FIG. 6 is a graph showing the relationship between the number of turns of the coil 27 and the inductance, where A is the area P ₁ × P ₂ = of the end surface 25a of the main pole.
0.039 mm ² , B is 0.027 mm ² , C is 0.0
The case of 1 mm ² is shown.

FIG. 7 shows the relationship between the inductance of the coil 27 wound around the core having the above-mentioned area of the end surface 25a of the main pole shown in FIG. 6 and the generated magnetic field strength. Here, the current supplied to the coil 27 is set to a maximum current of 0.2 A that can be supplied within a practical power consumption range in terms of the performance of the drive circuit.

FIG. 8 shows the relationship between the drive frequency and the magnetic field generation intensity for the core in which the number of turns A ₀ , B ₀ , C ₀ of the coil is 25 in FIG. 6 under the above-mentioned current supply. It is a thing. Here, in terms of the performance of the driving circuit, within a practical power consumption range, with respect to A ₀ , the frequency is 8M.
A constant generated magnetic field strength is obtained below Hz, but 8 MHz
If it exceeds, the strength of the generated magnetic field decreases. Also, B ₀ , C ₀
With respect to, the constant generated magnetic field strength can be maintained up to 8 MHz or more. Such a drop in magnetic field at high frequencies is
This is because the supply current decreases due to the performance of the driving circuit in the high frequency band. It has been experimentally confirmed that the maximum drivable frequency of the driving circuit is related to the inductance, and the inductance must be 2 μH or less to drive at a high frequency of 8 MHz or higher.
On the other hand, in order to perform good signal recording, the strength of the magnetic field generated by the magnetic head must be at least 100 Oe, preferably 120 Oe or more.

From the above premise, the area P ₁ × P ₂ of the end face of the main magnetic pole of the core must be 0.039 mm ² , that is, A or less (see FIG. 7). On the other hand, however, it is difficult to make the main magnetic pole 25b thinner than 0.01 mm ² , that is, C, due to the problem of mechanical strength during manufacture and use of the core. So, for example,
The area P ₁ × P ₂ of the end surface of the main pole is 0.027 mm
^It is appropriate to adopt a core dimension such as ² , ie B. Even in this case, if the number of windings of the coil is larger than B ₂ (31 times), the inductance exceeds 2 μH, and driving at 8 MHz or more becomes difficult due to the above-mentioned circumstances, which is not preferable. Also, if the number of turns of the coil is made smaller than B ₁ (14 turns), the inductance becomes smaller than 0.4 μH, and the generated magnetic field strength becomes insufficient due to the above-mentioned circumstances, which is also not preferable.

As described above, the area P ₁ × P ₂ of the end surface 25a of the main magnetic pole of the core 25 is 0.01 mm ² or more and 0.0
The optimum value is 39 mm ² or less, and the inductance is 0.4 μH or more and 2 μH or less. Further, in the actual embodiment, as shown in FIG. 1, the end surface 25a of the main magnetic pole of the core 25 is square, and the dimension P ₁ in the disc radial direction is slightly larger than the dimension P _{2 in} the tangential direction of the recording track. It is better to do. As a result, it is possible to prevent the light spot from deviating immediately below the main pole due to the relative displacement between the main pole and the light spot due to the tracking operation of the light spot with respect to the eccentricity of the recording track. Therefore, in reality, the size P ₁ of the end surface 25a of the main pole is
× P ₂ is 0.125 mm × 0.08 mm (= 0.01
mm ² ) or more, 0.23 mm × 0.17 mm (= 0.0
It is effective to set it to 39 mm ² ) or less.

Next, referring to FIG. 6, the number of coil turns B ₀ ,
For the cores B ₁ and B ₂ , the relationship between the area W ₁ × W ₂ of the winding window of the coil and the generated magnetic field strength when the supply current is 0.2 A will be described with reference to the graph shown in FIG. The generated magnetic field strength tends to gradually decrease with an increase in the area W ₁ × W ₂ of the winding window of the coil. If it is larger than 0.47 mm ² , B
_With respect to the core _{No. 1} , the magnetic field strength of 100 Oe necessary for good signal recording cannot be obtained at the minimum. On the other hand,
If it is smaller than 0.11 mm ^2, it is necessary to make the cross-sectional area of the wire used for winding the coil 27 smaller. In this case, the electric resistance of the coil 27 increases and heat generation due to current supply increases. Therefore, it is not preferable. Therefore,
The area W ₁ × W ₂ of the coil winding window of the core 25 is 0.11 m.
Most preferably, it should be at least m ² and at most 0.47 mm ² .

Next, referring to FIG. 6, the number of coil turns B ₀ ,
With respect to the B ₁ and B ₂ cores, the relationship between the distance d between the end face 25a of the main pole and the coil 27 and the generated magnetic field strength when the supply current is 0.2 A will be described with reference to the graph shown in FIG. The generated magnetic field strength tends to gradually decrease as the distance d between the end face of the main pole and the coil increases, and is 0.29 mm.
If it is larger than this, the magnetic field strength of 100 Oe necessary for good signal recording cannot be obtained for the core B ₁ . On the other hand, if the thickness is smaller than 0.05 mm, the wall thickness of the fixed portion of the main magnetic pole 25b of the slider 28 needs to be 0.05 mm or less in accordance with this.
In this case, mechanical strength during manufacture and use of the slider is insufficient, which may cause damage. From the above,
The distance d between the end surface 25a of the main pole and the coil 27 is 0.0
Most preferably, it is 5 mm or more and 0.29 mm or less.

Although the dimensions of each part of the magnetic head have been described above, these are all obtained assuming that the magnetic material of the core has sufficiently good magnetic characteristics. The magnetic field generating ability of the magnetic field greatly depends on the magnetic characteristics of the magnetic material. This will be described next. First, the magnetic permeability of the magnetic material will be described. Generally, the magnetic permeability of a magnetic material decreases as the frequency increases, but in a magnetic head for magneto-optical recording such as the present invention, the magnetic permeability of the magnetic material forming the core is at least as high as that of the recording signal. It is required to be 200 or more at the highest frequency. FIG. 11 shows the relationship between the magnetic permeability of the magnetic material forming the core and the strength of the generated magnetic field in a typical magnetic head, for example. As shown in the figure, the strength of the generated magnetic field is substantially constant when the magnetic permeability is sufficiently large, but when the magnetic permeability is less than 200,
As it decreases, it is not preferable. When the maximum frequency of the recording signal is as high as 8 MHz or higher, it is preferable that the core is made of Mn-Zn ferrite in order to obtain such high magnetic permeability.

Next, the relationship between the Curie temperature and the saturation magnetic flux density of the magnetic material forming the core will be described. FIG. 13 shows the effective saturation magnetic flux density Bm of a typical Mn-Zn ferrite.
It shows the temperature characteristics of s. Here, the magnetic material a
Has an effective saturation magnetic flux density of 4400 G at Curie temperatures of 140 ° C. and 25 ° C., and magnetic material b has an effective saturation magnetic flux density of 50 at Curie temperatures of 170 ° C. and 25 ° C.
00G, and the magnetic material c has a Curie temperature of 200.
It is a material having an effective saturation magnetic flux density of 5500 G at 25 ° C and 25 ° C. Generally, the saturation magnetic flux density of Mn-Zn ferrite decreases as the temperature increases, but it is understood from the figure that the material having a higher Curie temperature has a gentler temperature dependence.

Since the saturation magnetic flux density of Mn-Zn ferrite is finite, the magnetic field generated by the magnetic head cannot increase beyond a certain upper limit. This upper limit value is referred to herein as the saturation magnetic field strength H _S. This is shown in FIG. As shown in the figure, when the strength of the generated magnetic field is small, the generated magnetic field strength is proportional to the supply current. However, when the supply current is increased until the magnetic flux density in the core becomes equal to the saturation magnetic flux density, the saturation magnetic field strength increases. H _S is reached and cannot be increased beyond that. The saturation magnetic field strength H _S of the magnetic head is related to the saturation magnetic flux density of the magnetic material forming the core. As described above, the saturation magnetic flux density of Mn-Zn ferrite has temperature dependence. ,and,
Particularly, in the magnetic head for magneto-optical recording, the drive current is relatively large and the drive frequency is high,
The inventor of the present application has confirmed that the temperature rise of the core due to the high frequency loss of the magnetic head lowers the saturation magnetic flux density. Based on these facts, the relationship between the driving frequency of the magnetic head and the saturation magnetic field strength H _S was confirmed by experiments, and the results shown in FIG. 14 were obtained. Here, the core was optimized within the above-mentioned size range, and was made of the above-mentioned representative materials a, b, and c of Mn—Zn ferrite. In actual use, it is desirable that the operating region of the magnetic head is set to a region slightly lower than the saturation magnetic field strength H _S and the drive current is proportional to the generated magnetic field. Therefore, if the generated magnetic field is 100 Oe, the saturation magnetic field strength H _S needs to be 150 Oe or more. From the figure, this condition can be satisfied in the following cases. Specifically, it is a magnetic material a, that is, a magnetic head composed of Mn-Zn ferrite having a Curie temperature of 140 ° C. and an effective saturation magnetic flux density Bms of 4400 G at 25 ° C., and the driving frequency here is approximately maximum. 8 MHz, and the material B, that is, the effective saturation magnetic flux density B at Curie temperatures of 170 ° C. and 25 ° C.
A magnetic head composed of Mn-Zn ferrite whose ms is 5000 G, and the driving frequency here is about 10 M at maximum.
Hz, and the material c, that is, the Curie temperature is 200
With a magnetic head composed of Mn-Zn ferrite having an effective saturation magnetic flux density of 5500 G at 25 ° C and 25 ° C, the maximum driving frequency here can be about 12 MHz. As described above, it is important to configure the core of the magnetic head with a magnetic material having desirable magnetic characteristics according to the highest frequency of the recording signal. The materials a, b, and c of the Mn—Zn ferrite applied in the description of this embodiment can all be mass-produced by the current manufacturing technology.

The shape of the core is U as described above.
It is not limited to the letter shape, and for example, FIG.
As shown in (b) and (c), even in the case of an E-shaped, T-shaped, or ring-shaped core having a wide gap, the area P ₁ × P ₂ of the magnetic pole end surface 25a of the core and the area W _{1 of the} coil winding window. × W
_2. The distance d between the end face 25a of the main pole and the coil 27 is preferably set to the same value as described in the above-mentioned embodiment. However, in a T-shaped core as shown in (b), the main magnetic pole 25 that determines the width W ₁ of the coil winding window
Since there is no magnetic pole facing b, coil 27 is used instead of W _1.
If the width of W is W ′, W ′ × W ₂ may be set within the above range.

In the above embodiment, the magnetic head is a composite type in which the magnetic head is fixed to the flying slider made of a non-magnetic material, but the present invention is not limited to the magnetic characteristics of the magnetic material forming the core. Further, the present invention is also applied to a so-called monolithic type magnetic head in which the flying slider and at least a part of the core are integrally formed of a magnetic material.

[0034]

As described in detail above, the magnetic head for magneto-optical recording according to the present invention has, as the magnetic material forming the core,
A Curie temperature is 140 ° C. or higher, and at a temperature of 25 ° C., Mn—Zn ferrite having a magnetic permeability of 8 or more at a frequency of 8 MHz and an effective saturation magnetic flux density of 4400 G or more is used. Further, desirably, the Curie temperature is 170 ° C. or higher, and the frequency is 10 ° C. at a temperature of 25 ° C.
Permeability in MHz is 200 or more, effective saturation magnetic flux density is 5
Using Mn-Zn ferrite of 000 G or higher, or Curie temperature of 200 C or higher, permeability of 200 MHz or higher at a frequency of 12 MHz and effective saturation magnetic flux density of 5500 G or higher at a temperature of 25 C, There is.

The end surface area of the main magnetic pole of the core is 0.01
mm ² or more, 0.039 mm ² or less, the area of the coil winding window 0.11 mm ² or more, 0.47 mm ² or less, the distance between the end face and the coil of the main magnetic pole 0.05mm or more, 0.
The feature is that the length is 29 mm or less.

In the coil, the conductor has a cross-sectional area of 7 ×.
^10-4 mm ² or more and 5 × 10 ^-3 mm ² or less are formed by winding conductor wires, and the inductance is 0.4 μH or more,
The feature is that it is set to 2 μH or less.

Therefore, compared with the conventional magnetic head, the magnetic field generation efficiency is high despite the small inductance,
Even when the maximum frequency of the information signal to be recorded is increased to approximately 8 MHz or higher, it is possible to generate a sufficient magnetic field required for good signal recording within the range of power consumption allowed by the drive circuit. It will be. In addition, there is no risk of damage to the core due to lack of mechanical strength during manufacture and use of the magnetic head.

Further, in the magneto-optical recording apparatus according to the present invention, the maximum frequency of the recording signal is approximately 8 MHz or higher, and
As described above, the Curie temperature is 140 ° C. or higher and the magnetic head made of Mn—Zn ferrite having an effective saturation magnetic flux density of 4400 G or higher is mounted. Further, the magneto-optical recording device desirably has a maximum magnetic recording frequency of about 10 MHz or more, a magnetic head composed of Mn-Zn ferrite having a Curie temperature of 170 ° C. or more and an effective saturation magnetic flux density of 5000 G or more. It is installed.

In addition, the magneto-optical recording apparatus according to the present invention is composed of Mn-Zn ferrite having a maximum recording signal frequency of approximately 12 MHz or higher, a Curie temperature of 200 ° C. or higher, and an effective saturation magnetic flux density of 5500 G or higher. It is equipped with a magnetic head.

Therefore, the core temperature rises due to the high frequency loss when the magnetic head is driven at a high frequency,
Since the saturation magnetic flux density is lowered, it is possible to avoid the problem that a sufficient generated magnetic field necessary for good signal recording cannot be obtained.

[Brief description of drawings]

FIG. 1 is a partially enlarged view of a magnetic head for magneto-optical recording according to the present invention.

FIG. 2 is a partially enlarged view of a conventional magnetic head for magneto-optical recording.

FIG. 3 is a partially enlarged view of a conventional magnetic head for magneto-optical recording.

FIG. 4 is a diagram showing a schematic configuration of a magneto-optical recording device.

FIG. 5 is an overall perspective view of a magnetic head.

FIG. 6 is a diagram showing the relationship between the number of coil turns and the inductance.

FIG. 7 is a diagram showing a relationship between inductance and generated magnetic field strength.

FIG. 8 is a diagram showing a relationship between drive frequency and generated magnetic field strength.

FIG. 9 is a diagram showing a relationship between a coil winding window area and a generated magnetic field strength.

FIG. 10 is a diagram showing the relationship between the distance between the end surface of the main pole and the coil and the generated magnetic field strength.

FIG. 11 is a diagram showing a relationship between magnetic permeability and generated magnetic field strength.

FIG. 12 is a diagram showing a relationship between a supply current and a generated magnetic field strength.

FIG. 13 is a diagram showing a relationship between temperature and effective saturation magnetic flux density.

FIG. 14 is a diagram showing a relationship between drive frequency and saturation magnetic field strength.

FIG. 15 is a view showing another embodiment (a) to (c) in which the core shapes are different from each other.

[Explanation of symbols]

 25 core 25a end face of main pole 25b main pole 27 coil 28 slider

Claims (11)

[Claims] 1. A floating slider that floats by an air flow on a magneto-optical recording medium, a core made of a magnetic material mounted on the floating slider, and a coil wound around the core, and a voltage applied to the coil. In a magnetic head for magneto-optical recording in which a modulation magnetic field is applied to the recording surface of the magneto-optical recording medium to record an information signal by application, the area of the main magnetic pole end surface of the core is 0.01 mm ² or more. 0.039
When the magnetic material is less than or equal to mm ² , the core magnetic material is
A magnetic material for magneto-optical recording characterized by being a Mn-Zn ferrite having a Curie temperature of 140 ° C or higher and a magnetic permeability of 200 or higher at a frequency of 8 MHz and an effective saturation magnetic flux density of 4400G or higher at a temperature of 25 ° C. head. 2. A levitation slider that is levitation by an air flow on a magneto-optical recording medium, a core made of a magnetic material mounted on the levitation slider, and a coil wound around the core, and a voltage applied to the coil. In a magnetic head for magneto-optical recording in which a modulation magnetic field is applied to the recording surface of the magneto-optical recording medium to record an information signal by application, the area of the main magnetic pole end surface of the core is 0.01 mm ² or more. 0.039
When the magnetic material is less than or equal to mm ² , the core magnetic material is
A magnetic material for magneto-optical recording, characterized in that it is a Mn-Zn ferrite having a Curie temperature of 170 ° C. or higher and a magnetic permeability of 200 or higher at a frequency of 10 MHz and an effective saturation magnetic flux density of 5000 G or higher at a temperature of 25 ° C. head. 3. A flying slider, which is levitated by an air flow on a magneto-optical recording medium, a core made of a magnetic material mounted on the flying slider, and a coil wound around the core, and a voltage applied to the coil. In a magnetic head for magneto-optical recording in which a modulation magnetic field is applied to the recording surface of the magneto-optical recording medium to record an information signal by application, the area of the main magnetic pole end surface of the core is 0.01 mm ² or more. 0.039
When the magnetic material is less than or equal to mm ² , the core magnetic material is
A magnetic material for magneto-optical recording, characterized in that it is a Mn—Zn ferrite having a Curie temperature of 200 ° C. or higher and a magnetic permeability of 200 or higher at a frequency of 12 MHz and an effective saturation magnetic flux density of 5500 G or higher at a temperature of 25 ° C. head. 4. The magnetic head is a composite type in which a core having a main magnetic pole is fixed to a flying slider made of a non-magnetic material, and the end surface of the main magnetic pole of the core has a substantially rectangular shape, and its area is 0. 01 mm ² or more, 0.039 mm ²
It is set as follows, Claim 1, 2 or 3 characterized by the above-mentioned.
A magnetic head for magneto-optical recording according to item 1. 5. The distance between the end surface of the main pole of the core and the coil is set to 0.05 mm or more and 0.29 mm or less.
Alternatively, the magnetic head for magneto-optical recording according to item 4. 6. the area of coil winding window in said core, 0.11 mm ² or more, according to claim 1, 2, 3, 4 or 5, characterized in that it is set to 0.47 mm ² or less Magnetic head for magneto-optical recording. 7. The coil has a conductor with a cross-sectional area of 7 ×
7. The magnetic head for magneto-optical recording according to claim 1, wherein the magnetic head is formed by winding a conductor wire of 10 ⁻⁴ mm ² or more and 5 × 10 ⁻³ mm ² or less. . 8. The magnetic head for magneto-optical recording according to claim 1, wherein the coil has an inductance of 0.4 μH or more and 2 μH or less. 9. The highest frequency of the recorded signal is approximately 8 MH.
z or more, and the mounted magnetic head for magneto-optical recording is
It is composed of a flying slider that floats by an air flow on a magneto-optical recording medium, a core made of a magnetic material mounted on the flying slider, and a coil wound around the core. An information signal is recorded by applying a modulation magnetic field to the recording surface of a magnetic recording medium, and the magnetic material forming the core has a Curie temperature of 140 ° C. or higher, and at a temperature of 25 ° C., a frequency of 8 MHz. A magneto-optical recording device comprising a Mn-Zn ferrite having a magnetic permeability of 200 or more and an effective saturation magnetic flux density of 4400 G or more. 10. The highest frequency of the recorded signal is approximately 10.
A magnetic head for magneto-optical recording having a frequency of MHz or more, which is mounted on the magneto-optical recording medium, is floated by an air flow on the magneto-optical recording medium, a core made of a magnetic material mounted on the flying slider, and wound around the core. A coil, and by applying a voltage to the coil, a modulation magnetic field is applied to the recording surface of the magneto-optical recording medium to record an information signal,
The magnetic material forming the core has a Curie temperature of 170 ° C. or higher, and has a magnetic permeability of 200 or higher at a frequency of 10 MHz and an effective saturation magnetic flux density of 5000 G at a temperature of 25 ° C.
A magneto-optical recording device comprising the above Mn-Zn ferrite. A magneto-optical recording apparatus comprising the magneto-optical recording magnetic head according to claim 2. 11. The highest frequency of the recorded signal is approximately 12.
A magnetic head for magneto-optical recording having a frequency of MHz or more, which is mounted on the magneto-optical recording medium, is floated by an air flow on the magneto-optical recording medium, a core made of a magnetic material mounted on the flying slider, and wound around the core. A coil, and by applying a voltage to the coil, a modulation magnetic field is applied to the recording surface of the magneto-optical recording medium to record an information signal,
The magnetic material forming the core has a Curie temperature of 200 ° C. or higher, and at a temperature of 25 ° C., the magnetic permeability at a frequency of 12 MHz is 200 or higher, and the effective saturation magnetic flux density is 5500 G.
A magneto-optical recording device comprising the above Mn-Zn ferrite.