JP2000348301A - Magneto-optical head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a strong magnetic field even if a quantity electric current flowing through a coil is small or the number of winding of the coil is reduced by magnetically connecting a side core provided in opposition to a center core to the center core to constitute a magnetic circuit. SOLUTION: A three-layer film consisting of a glass film 3, a soft magnetic film 4 and a glass film 3 is provided between the butted surfaces between cores 1, and the glass film 3 is made to function as an adhesive film for fixing the soft magnetic film 4 to the core 1. The center core of an E shaped magnetic core is composed of the laminated structure body of the magnetic core 1/the glass film 3/the soft magnetic film 4/the glass film 3/ the magnetic core 1. Stops 6 are formed in both sides of the tip end opposing to the medium of the center core, and the side opposing to the center core side of the U shaped core 1 becomes a side core. A magnetic core 10 functions as a magnetic field generating means by winding a winding wire coil 2 around the center core.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a magneto-optical head mounted on a magneto-optical storage device, and more particularly to a magneto-optical head having a magnetic core with improved recording performance.

[0002]

2. Description of the Related Art A magneto-optical storage device includes a magneto-optical medium (disk), a magnetic field generating means for applying a magnetic field to the magneto-optical medium, and a light irradiating means for irradiating a laser beam to a location where the magnetic field is applied. And records a signal on a magneto-optical medium by optical modulation or magnetic modulation. Hereinafter, the magneto-optical medium is referred to as a disk. In this specification, the term magneto-optical head is
It is used in a broad sense, including the following types: The first type is a magneto-optical head having only a magnetic field generating means for applying a magnetic field to a disk. The second type is a magneto-optical head of a type having both a magnetic field generating means and a light irradiating means. This type includes a means for irradiating a laser beam to a disk through a lens, and a magnetic field generating means such as a coil and a permanent magnet. Both means are mounted on a translation carriage or a slider with suspension.

In the first type, a magneto-optical head provided with a magnetic field generating means and a light irradiating means are provided as separate components in a magneto-optical storage device. The magnetic field generating means is often mounted on a slider. The slider is placed on the disk supported by the suspension. When the disk rotates, the slider flies due to the buoyancy caused by the airflow generated on the disk, and the magnetic field generating means and the disk oppose each other at a fixed interval (floating amount). The magnetic field generating means applies a magnetic field to the disk. In a general magneto-optical storage device, the slider is levitated above the surface of the disk, and laser light is irradiated from the back surface of the disk by light irradiation means. For example, a U-shaped magnetic core provided with a winding coil and an E-shaped magnetic core provided with a coil bobbin are used as these conventional magnetic field generating means. There is a type in which the magnetic core is joined to the rear end of a slider made of a nonmagnetic ceramic substrate. Usually, one core block, which is a component of the magnetic core, serves as a main magnetic pole of a magnetic circuit for applying a magnetic field, and the other core block serves as a return path of the magnetic circuit.Current is supplied to a coil wound on the magnetic core. Then, a perpendicular magnetic field is applied to the disk. Hereinafter, a core block that is a component of the magnetic core is referred to as a core.

An example of a recording / reproducing operation of the magneto-optical storage device will be described. In the case of recording, when a laser beam is irradiated while applying a magnetic field in a direction opposite to the direction in which the disk is magnetized in advance from the coil, the magnetization direction of the bit is reversed. Using this operation, information can be recorded by controlling the inversion for each bit. When reproducing, the magnetized bits are irradiated with laser light, the direction of rotation of the plane of polarization of the reflected laser light is detected, and the recorded information is reproduced. This rotation of the polarization plane utilizes the Kerr effect. When deleting,
When a laser beam is irradiated while applying a magnetic field from the coil in the same direction as the direction in which the disk has been magnetized in advance, the information recorded in the bits is erased. A disk used for such recording / reproducing includes a recording film of a TbFeCo layer and Gd.
A structure in which a multilayer film having an FeCo regenerated film or the like is laminated on a substrate is used. The substrate is made of polycarbonate, glass, or the like.

[0005] In the field of magneto-optical recording or magneto-optical head, the following techniques can be given as techniques relating to the shape of the magnetic core. JP-A-8-45129 discloses a magnetic head for magneto-optical recording of a slider having a core in which a main magnetic pole and an auxiliary magnetic pole are integrally formed in an E-shape. JP-A-6-131608 discloses a magneto-optical disk drive using a U-shaped yoke. Other types of magnetic cores include a type formed of a material such as ferrite, in which the tip of a center core or a main magnetic pole (main core) is machined at an acute angle in order to improve the magnetic flux density.

[0006]

As the recording frequency increases with the increase in recording density, it becomes difficult for a current to flow through the coil wrapped around the magnetic core, making it difficult to obtain a magnetic field required for recording operation. It is getting. Also, if a large current is forced to flow through the coil, the device or disk may be heated and distorted due to heat generation, or a circuit that generates a large current may be incorporated into the magneto-optical storage device, which is against the miniaturization of the device. Was a problem. On the other hand, if the number of turns of the coil is reduced or the size of the core is reduced in order to reduce the inductance, the strength of the magnetic field applied to the disk itself decreases. SUMMARY OF THE INVENTION It is an object of the present invention to provide a high-efficiency magneto-optical head capable of obtaining a strong magnetic field even when the current flowing through the coil is small or the number of turns of the coil is reduced.

[0007]

According to the present invention, there is provided a magneto-optical head comprising: a center core; a soft magnetic film provided along a longitudinal direction of the center core; a step provided at a tip of the center core; And a coil wound therearound. Side cores are provided on at least one side of the center core so as to face each other. The center core and the side core are magnetically connected by a back core,
Construct a magnetic circuit. It is preferable that the center core, the back core, and the side core are integrally formed of the same magnetic material. When the soft magnetic film is disposed parallel to the longitudinal direction of the center core, the longitudinal direction of the soft magnetic film is in a relationship orthogonal to the surface of the medium. Also, the center core preferably has a laminated structure in which ceramic cores are provided on both sides of the soft magnetic film via a glass film.

Another magneto-optical head according to the present invention has at least two or more cores joined via a soft magnetic film, and a member along the soft magnetic film is used as a center core, and a tip of the center core is provided. Is provided with a step.
Further, another magneto-optical head of the present invention has a U-shaped core,
A soft magnetic film is provided on a side surface of the core, a glass film is provided between the soft magnetic film and the core, and a step is provided at a tip portion of the core. Preferably, the step is provided on a side of the core opposite to a side on which the soft magnetic film is provided.

[0009] The magnetic core is as follows. A U-shaped core, a soft magnetic film and another U-shaped core are combined, and a glass film is provided between the soft magnetic film and the core. A step is provided. With this configuration, the soft magnetic film is arranged so as to overlap the center axis of the center core.

In the center core, a step is provided on a surface opposite to the surface on which the soft magnetic film is provided. By this step, the width of the tip of the center core can be reduced, and the magnetic flux can be effectively concentrated on the soft magnetic film. In the step, the surface is a surface composed of a plurality of surfaces, a surface combining a plane and a curved surface, a surface connecting a plane to a plane, a surface connecting a plane to a curved surface, a single curved surface, and a surface connecting a plurality of curved surfaces. , A plane, a curved surface, and a plane in which the planes are sequentially connected. However, the corners (i.e., ridges) where the planes intersect prevent the magnetic field from being narrowed down or cause the magnetic field to leak. Therefore, it is desirable to form the step portion with a curved surface to narrow down the magnetic field efficiently.
The radius of curvature r of the curved surface of the step may be in the range of 15 to 50 [μm], but preferably 20 ≦ r ≦ 40.
[Μm]. The above steps are preferably provided on both side surfaces of the tip of the center core. By adding both the step and the soft magnetic film, the magnetic flux can be sufficiently reduced at the tip of the small center core, and a magnetic field of high frequency and high saturation magnetic flux density can be applied to the disk for high density recording.

In the above-mentioned magneto-optical head, an E-shaped magnetic core, a U-shaped core, or a U-shaped core can be used as the magnetic core shape. It is desirable to have the shape of a mold. When a disk for perpendicular magnetic recording is used, there is an advantage that noise can be suppressed by increasing the magnetic flux density of the magnetic field applied from the center core to the disk and decreasing the magnetic flux density of the magnetic field returning from the disk to the side core.

In the above magnetic core, a magnetic film having a high saturation magnetic flux density is used as the soft magnetic film. For example, FeTaN,
A magnetic film of FeTaNCr, FeAlSi, FeTaC, or the like can be used, and its film thickness is about 2 to 6 [μm]. The core interval of the magnetic cores used in the above-mentioned magneto-optical head is manufactured in the range of 200 to 500 [μm].
It is preferable that ≦ core interval ≦ 300 [μm]. The core interval corresponds to the distance between the center core tip and the side core tip, and is also referred to as a gap.

The center core has a structure in which soft magnetic blocks are bonded to both surfaces of a soft magnetic film via glass films.
The rear side of the center core is integrally formed with the two side cores of the magnetic block via the back core of the magnetic block. The side core functions as a back path where the magnetic field applied to the disk from the center core returns. The winding is wound around a core having a step or a center core. Therefore, the magnetic circuit is a path that passes through the center core / disk / side core / back core and returns to the center core. Mn-Zn ferrite,
It is desirable to use a magnetic material such as Ni-Zn ferrite.

In the present invention, a target structure is joined to both sides of the soft magnetic film in the E-shaped core. Then, the stress distribution in the center core becomes symmetrical and cancels out, and even if different materials such as soft magnetic film / glass film / core are joined,
Deterioration of magnetic properties due to stress strain is suppressed. In the above-mentioned magnetic core, since the thin soft magnetic film is arranged on the center line of the center core, the magnetic flux density is maximum near the center of the center core. At first glance, it seems difficult to control the position on the center core and disk. However,
By combining the suspension / slider driven by the VCM with the magnetic core of the present invention, it is possible to perform magneto-optical recording in which a magnetic field having a high saturation magnetic flux density is applied to a disk with high precision positioning.

Preferably, the slider of the magneto-optical head of the present invention is provided on a suspension driven by a VCM (voice coil motor), and at least one actuator is provided between the VCM drive shaft (rotation shaft) and the slider. Thus, the magneto-optical head can be arranged on the disk with more precise position control. The following types are mentioned as this actuator. The first type is a type in which a joint is provided in the middle of the suspension, and this joint is driven by a small magnet or VCM. The second type is a type in which a microactuator driven by electrostatic force or magnetic force is provided between a slider and a suspension. The third type is a type in which the slider itself is deformed as an actuator for correcting positional deviation. Of these, considering the matching of the driving frequency, it is possible to cope with a high driving frequency by combining the second type with the magneto-optical head.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A magneto-optical head according to the present invention will be described below with reference to the drawings. 1 to 3 are cross-sectional views according to an embodiment of the magnetic core included in the magneto-optical head of the present invention. FIG. 4 is a graph illustrating the relationship between the magnetomotive force and the magnetic field strength. 5 and 6 are schematic diagrams of a slider provided with these magnetic cores. FIG. 7 is a sectional view of a magnetic core according to an embodiment of the magneto-optical head of the present invention. FIG. 8 is a plan view of a suspension according to the magneto-optical head of the present invention. FIG. 9 is a cross-sectional view illustrating a state in which the magneto-optical head with suspension of FIG. 8 is floated on a disk. FIG. 10 is a process diagram illustrating a method for manufacturing a magnetic core according to the present invention. FIG. 11 is a schematic diagram illustrating a step shape of the magnetic core according to the present invention.

First, an embodiment of the magnetic core will be described with reference to FIG. This magnetic core is an E-shaped magnetic core 10 in which two U-shaped cores 1 are joined together. Between the contact surfaces of the cores 1, a three-layer film including the glass film 3, the soft magnetic film 4 and the glass film 3 was provided. Glass film 3
Functioned as an adhesive film for fixing the soft magnetic film 4 and the core 1. The center core of the E-shaped magnetic core was constituted by a laminated structure of magnetic core 1 / glass film 3 / soft magnetic film 4 / glass film 3 / magnetic core 1. Step 6 was formed on both sides of the front end of the center core facing the medium. The side of the U-shaped core 1 facing the center core is a side core, and a portion connecting the side core and the center core is a back core. A glass member 5 for maintaining strength may be formed between the center core and the side cores. This glass member 5 is added when the magnetic core 10 is fixed to the slider, and is attached to the magnetic core itself. The attachment of the glass member 5 can be selectively performed as needed. By winding the winding coil 2 around the center core, the magnetic core 10 functions as a magnetic field generating means. The material of the core 1 was nickel zinc ferrite. The material of the soft magnetic film is FeT
aNCr.

FIG. 2 illustrates another embodiment of the magnetic core according to the present invention. This magnetic core has an L-shaped core
It is a U-shaped core 1 in which a U-shaped (square bar) core is attached. A glass film 3 is provided on the contact surface side of the I-shaped core.
And a two-layer film made up of a soft magnetic film 4. The glass film 3 functioned as an adhesive film fixing the soft magnetic film 4 and the core 1.
The center core was composed of a laminated structure of an I-shaped core / glass film 3 / soft magnetic film 4. Step 6 was formed on one side of the front end of the center core facing the medium. The L-shaped core includes a side core and a back core. A glass member 5 for maintaining strength was provided between the center core and the side core. As another embodiment, when using a structure in which a soft magnetic film is provided on the side surface of a U-shaped core block, the glass member 5 is not provided.

FIG. 3 illustrates another embodiment of the magnetic core according to the present invention. The magnetic core 1 has a structure in which a protruding portion is provided at the tip of a side core in the magnetic core of FIG. By providing the protruding portion facing the center core, the distance (gap interval) between the center core and the side core can be reduced, and a wide space for winding the winding coil 2 around the center core can be secured. If the size of the magnetic core is reduced without providing the protrusion, it becomes difficult to wind the winding coil around the center core using an automatic coil winding device. If it is wound by hand, the manufacturing process takes too much time.

The magnetic cores shown in FIGS. 1, 2 and 3 have a core interval of 200, 250, 300, 35.
Samples having 0, 400, 450, and 500 [μm] were prepared. At these dimensions, a magnetic core without a step and a soft magnetic film (Comparative Example) was compared with the magnetic core of the present invention. FIG. 4 shows the relationship between the magnetomotive force and the magnetic field strength changed according to the current value. The horizontal axis in FIG. 4 indicates the magnetomotive force [AT] due to the current, and the vertical axis indicates the magnetic field strength H measured at a position 30 μm below the tip of the magnetic core. Here, the term “down” refers to a direction toward the disk as viewed from the tip of the magnetic core. It has been found that the E-shaped magnetic core according to the present invention can obtain a sufficient magnetic field with a lower electromotive force than the magnetic core of the comparative example. Therefore, even if the frequency is increased, a sufficient magnetic field can be obtained without increasing the current. Also, by using this margin, the number of coil turns can be reduced, and a magnetic head that operates even at high frequencies can be obtained.

FIG. 5 shows three schematic views of a slider provided with a magnetic core according to the present invention. FIG. 5A is a plan view of the slider viewed from the air bearing surface, and FIG. 5B is a cross-sectional view of the slider taken along the line AA. FIG. 5 (c)
FIG. 4 is a side view of the slider viewed from the trailing side.
The trailing side refers to the side from which the rotating disk as viewed from the slider 12 exits. In this magneto-optical head slider, two cutouts were formed in a ceramic substrate. The first notch is a recess 14 formed by cutting the back surface of the slider (the surface on the anti-floating surface side) along the wall surface 13 so as to open to the trailing side. Has the function of alleviating the distortion generated in The second notch is the slider's floating surface 15
And a slit that penetrates into the recess 14, and is a place where the magnetic core of the present invention is fixed via the fixing glass 11b. The magnetic core was fixed so that the surface of the distal end portion 9 squeezed in the step of the center core coincided with the air bearing surface 15.

FIG. 6 shows three schematic views of a slider according to another embodiment of the present invention. FIG. 6A is a plan view of the slider viewed from the air bearing surface, and FIG. 6B is a side view of the slider. FIG. 6C is a side view of the slider viewed from the trailing side. This magneto-optical head slider was provided with four cutouts in a ceramic substrate. The first notch is a recess 14 formed by cutting out the back surface (surface on the side opposite to the floating surface) of the slider so as to open to the trailing side along the wall surface 13. The other three notches are two side cores 1a of the magnetic core of FIG.
And one center core 1c to the slider via a fixing glass 11b. Magnetic core 1
0a was fixed so that the surface of the tip portion 9 squeezed in the step of the center core coincided with the air bearing surface 15. FIG. 7 shows a magnetic core of the type provided in the slider of FIG. The (a) magnetic core 10a of FIG.
The center core and the side core are separated from each other so as to be easily inserted into the second core. In the magnetic core shown in FIG. 7B on the right side, the back core is formed integrally with the side core. A winding coil 16 was wound around the center core.

FIG. 8 is a plan view of the slider of FIG. 6 provided with a suspension, as viewed from the floating surface side. A gimbal 17 having a convex portion called a pivot is arranged between the suspension 18 and the slider 12, and the flexure of the gimbal gives a degree of freedom to the inclination of the slider along the X axis and the Y axis in the drawing. The dimensions of the magnetic core exposed on the air bearing surface were as follows. That is, the distance g1 between the center core and one side core and the distance g2 between the center core and the other side core were each 300 [μm]. The slider had a width ds of 1.6 [mm] and a length of 2.0 [mm]. The air bearing surface constitutes one surface integrally with the exposed surface of the magnetic core and the surface of the fixing glass, but has a crown along the direction of the Y axis in FIG. The crown refers to a surface where the center of the air bearing surface is thicker than the trailing side of the air bearing surface and the opposite end.

FIG. 9 is a sectional view for explaining a state in which the suspension of FIG. 8 is levitated above the disk. The actual disk is obtained by laminating multilayer films on a substrate.
For ease of explanation, the layers are not distinguished, and the cross section of a cell corresponding to a recording bit is schematically illustrated. dm corresponds to the width of one recording bit. The magnetic field generated from the center core of the magnetic core is applied to the disk around the bit irradiated with the laser light. The magnetic field penetrating the bit is dispersed and forms a magnetic circuit that returns to each of the two side cores through the disk and returns to the center core through the back core.

In the recording operation, in the magneto-optical head slider 12 flying above the disk 19, a current was applied to the winding coil to generate a recording magnetic field from the magnetic core. At the same time, the cell to which the recording magnetic field was applied was irradiated with laser light guided by the condenser lens 20 from the opposite side of the disk to change the direction of the bit magnetization and record a signal. Although not shown in FIG. 9, the disk 19 is rotated at a high speed in a direction opposite to the Y direction, and a bearing, a spindle motor, and the like are connected to a central axis thereof. The magneto-optical storage device includes a laser light generator and a lens
An optical path switching / introducing member provided between them is also mounted. The parameters to be implemented were as follows. The frequency f of the recording magnetic field was 20 [MHz], and the recording magnetic field applied to the medium was about 16 [kA / m]. The parameters of the disk device are as follows: the recording density is 6.0 GB / diameter 120 mm, the track pitch is 0.6 [μm], the laser wavelength is 650 [nm], the NA of the optical system is 0.6, The thickness was 0.6 or 1.2 [mm], and the data transfer rate was 15.3 to 35.9 [Mbps].

A laser pulse magnetic field modulation system (MFM: Magnetic F) that performs recording magnetic field modulation in accordance with data and laser pulse irradiation in accordance with a data clock.
field). Specifically, high-density writing was performed by eclipse recording in which the laser spot was shifted while overwriting. For the reproduction, a center aperture type magnetic super solution technique was used. The recording density of the disk (magneto-optical medium) used here was in the range of about 1.2 to 6 [GB / disk], but the recording density was higher than 6.0 [GB].
The recording frequency of 20 [MHz] or more is also effective. By using the magneto-optical head having the magnetic core of the present invention, it was possible to apply a small, intense magnetic field at a high frequency to a narrow bit in the magneto-optical medium.

A method of manufacturing a magnetic core according to the present invention will be described with reference to the process chart of FIG. First, a long prismatic ferrite block is prepared, and a groove is formed in the ferrite block by cutting with a dicing cutter. Next, a glass film is formed on the side surface of the ferrite block by sputtering, and FeTaN is formed on the glass film as a soft magnetic film.
A first ferrite block was formed by depositing a Cr film.
The atmosphere in the sputtering apparatus for the glass film was argon, but the atmosphere for the FeTaNCr film was a mixture of argon and nitrogen (step s1). Note that a second ferrite block in which only a glass film was provided on the side surface of the ferrite block in which the groove was provided was manufactured in the same manner.

Next, the first ferrite block FeT
The surface of the aNCr film was brought into contact with the surface of the glass film of the second ferrite block and fixed with a jig. At the time of abutting, the surface of the ferrite block on which the groove was not formed was made to coincide with the same plane. The two ferrite blocks thus fixed in a jig were introduced into a heating device and heat-treated. By this heat treatment, the glass film goes through a softened state,
The ferrite block and the soft magnetic film were fixed together as a result of re-hardening by cooling upon completion of the heat treatment. In the above steps, E
A letter-shaped ferrite block was obtained (step s2).

Next, the center core in the center of the E-shaped ferrite block was provided with steps by cutting both sides of the tip. This cutting was performed by applying a micro grinder to one end face of the center core along a direction parallel to the longitudinal direction of the E-shaped ferrite block. Subsequently, a step was similarly formed on the other end face by cutting (step s3). Next, glass members 5 were provided in both grooves of the E-shaped ferrite block and fixed by heat treatment (step s4). Subsequently, the E-shaped ferrite block was cut with a wire saw along a plane orthogonal to the longitudinal direction to obtain an E-shaped magnetic core 10 (step s5). When manufacturing a magnetic core that does not require the glass member 5, step s4 was omitted and step s3 was performed directly.

FIG. 11 shows a step shape provided on the magnetic core according to the present invention. FIG. 11A is an enlarged perspective view of the tip of the ferrite of the center core. The thinned tip portion 6 was provided with a step consisting of a flat surface 6a, a curved surface 6b, and a flat surface 6c. The plane 6a is a plane (XZ plane) parallel to the surface on the side where the step is not provided at the tip end. FIG. 11B is a cross-sectional view of the distal end portion of FIG. The angle θ formed by the plane 6a and the plane 6c is 90 ° ≦ θ <
It is desirable to set it to 150 °. FIG. 11C is a cross-sectional view illustrating a tip portion provided with steps having different shapes. To further reduce the magnetic field generated from the tip of the magnetic core, the structure of the step is defined as follows.

The vertical and horizontal dimensions of the step correspond to a step depth of 50 to 150 [μm] in the vertical direction and a thickness of 50 to 100 [μm] of the tip of the magnetic core in the horizontal direction. Processed as follows. The shaving width for shaping the original width of the magnetic core to form the step at the tip of the magnetic core is 20 to 30.
[Μm]. In these dimensions, the following configuration was added to efficiently restrict the flow of magnetic flux in the center core and to cope with high-frequency magnetic fields. That is,
For the type of FIG. 11B, θ is 100, 11
Samples of 5, 120 and 130 [°] were prepared, and good characteristics were obtained. For the type of FIG. 11C, r = 15, 2 for sample (1) and sample (2).
Those having 0, 30, 40, and 50 [μm] were produced, and good characteristics were obtained. For sample (3), sample (4) or sample (5), a domain wall was formed in the core along the bent surface, and the efficiency of generating a magnetic field from the center core was reduced.

[0032]

As described above, by using the structure of the present invention, a high-efficiency magneto-optical head capable of applying a strong magnetic field to a disk even with a small magnetomotive force was obtained.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a magnetic core included in a magneto-optical head according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view according to an embodiment of a magnetic core included in the magneto-optical head of the present invention.

FIG. 3 is a cross-sectional view according to an embodiment of a magnetic core included in the magneto-optical head of the present invention.

FIG. 4 is a graph illustrating a relationship between a magnetomotive force and a magnetic field intensity in the magneto-optical head.

FIG. 5 is a schematic view of a slider provided with a magnetic core according to the present invention.

FIG. 6 is a schematic view of a slider provided with a magnetic core according to the present invention.

FIG. 7 is a cross-sectional view according to an embodiment of a magnetic core provided in the magneto-optical head of the present invention.

FIG. 8 is a plan view of a suspension according to the magneto-optical head of the present invention.

9 is a cross-sectional view illustrating a state where the suspension of FIG. 8 is levitated above a disk.

FIG. 10 is a process diagram illustrating a method for manufacturing a magnetic core according to the present invention.

FIG. 11 is a schematic diagram illustrating a step shape of a magnetic core according to the present invention.

[Explanation of symbols]

1 core, 2 winding coil, 3 glass film, 4
Soft magnetic film, 5 glass member, 6 steps, 6a plane, 6b curved surface, 6c plane, 9 tip, 10 magnetic core, 11 slit, 11b fixing glass, 12
Slider, 13 wall, 14 dent, 15 air bearing surface, 16 wound coil, 17 gimbal, 18
Suspension, 19 magneto-optical medium, 20 condenser lens.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5D075 AA03 BB04 CC04 CF03 5D091 AA08 CC20 CC24 HH20 5D093 AA03 AD05 BA15 BE15

Claims (3)

[Claims] 1. A center core, a soft magnetic film provided along a longitudinal direction of the center core, a step provided at a tip of the center core, and a coil wound around the center core. Magneto-optical head. 2. A U-shaped core, a soft magnetic film provided on a side surface of the core, a glass film between the soft magnetic film and the core, and a step provided at a tip portion of the core. A magneto-optical head, characterized in that: 3. The magneto-optical head according to claim 1, wherein the step includes a curved surface, and a radius of curvature r of the curved surface is in a range of 15 ≦ r ≦ 50 [μm]. .