JP3348364B2 - Magnetic head and magneto-optical recording medium recording device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic field modulation head for recording data on a magneto-optical disk or the like in a plurality of modes having different linear velocities by magnetic field modulation, and to a magneto-optical recording medium recording apparatus.

[0002]

2. Description of the Related Art There are an optical modulation method and a magnetic field modulation method as a direct overwrite method for recording data on a magneto-optical disk. The optical modulation method means that a magnetic field in a fixed direction is always applied on the magnetic film of the magneto-optical disk during writing.
This method records information by condensing an optical beam turned on / off by a recording signal on the surface of a magnetic film. On the other hand, with the magnetic field modulation method, information is recorded by applying continuous light or pulsed light onto the magnetic film surface while reversing the direction of the magnetic field according to the recording signal while condensing the light on the magnetic film surface. It is a method.

[0003] The former method enables extremely high-speed modulation, and is effective for a magneto-optical recording system with a high transfer rate. On the other hand, the latter method is suitable for stabilizing and increasing the density of a magneto-optical recording system because a stable and clear pit can be created without depending on the skew of the disk at the time of writing.

In the case of employing the magnetic field modulation overwrite method among the two recording methods, it is necessary to rapidly reverse the direction of the magnetic field generated from the magnetic field modulation head. This speed may reach several MHz when a digital video disc is used, for example.

FIG. 7 is a schematic diagram of such a magnetic field modulation head. The magnetic field modulation head 10 includes a head core 11, a coil 12 provided on the head core 11, a head core 1
1 and a suspension 15 for supporting the head core holding part 13.

The magnetic field modulation head 10 is arranged so that its head core 11 faces an objective lens 18 provided on an optical pickup 17 via a magneto-optical disk 16.

In order to achieve the reversal of the magnetic field at a speed of about several MHz by the magnetic field modulation head 10, it is necessary to keep the inductance of the magnetic field modulation head 10 low.
Therefore, the diameter of the head core 11 must be set to about 300 μm square or less, and a large amount of current cannot flow.

FIG. 8 shows the relationship between the distance from the tip of the core 11 of the magnetic field modulation head and the magnetic field strength. If the diameter of the head core Ru Oh below about 300μm square, the magnetic field modulation head 10
Since the current flowing through the head core 11 is also limited, the area of the effective magnetic field generated from the head core 11 is 100
It is almost limited to the region of μm or less. Magneto-optical disk 16
In order to apply a magnetic field of 150 Oe or more to the recording medium layer, it is necessary to always keep the distance between the head core 11 and the recording surface of the magneto-optical disk 16 at several tens μm or less.

Therefore, as means for limiting the distance between the magnetic field modulation head 10 and the magneto-optical disk 16, a sliding method and a dynamic pressure floating method (flying head method) have been proposed.

FIGS. 9 to 11 show a magnetic field modulation head used in a sliding system. The magnetic field modulation head 20 includes a magneto-optical disk surface several tens μm below the head core 22 held by the head core holding unit 21 and the magnetic field modulation head 20.
Is provided with a plastic sliding surface 22 having a very low coefficient of friction with the magneto-optical disk surface. Also, the magnetic field modulation head 20 is
6 is supported by the suspension 24 so as to be pressed against the suspension 6.

This sliding method is a method suitable for controlling the distance between the magnetic field modulation head 20 and the magneto-optical disk 16 during recording at a low linear velocity. However, since the magnetic field modulation head 20 and the magneto-optical disk 16 are always in contact with each other at the time of recording, the reliability of the magneto-optical disk 16 and the magnetic field modulation head 20 becomes a problem when performing recording at a high linear velocity. At the same time, the magnetic field modulation head 20 jumps from the magneto-optical disk 16 due to protrusions and dirt present on the surface of the magneto-optical disk, and the reaction force causes the disk to be instantaneous, causing defocus.

FIGS. 12 and 13 show a magnetic field modulation head used in the dynamic pressure levitation method. The magnetic field modulation head 25 has a holding portion 27 of a head core 26 and a magneto-optical disk 1.
When the disk 6 rotates, an air bearing surface 28 and a rail 29 are provided for floating the magnetic field modulation head 25 from the magneto-optical disk 16 by dynamic pressure generated between the magnetic field modulation head 25 and the magneto-optical disk 16.

In this flying system, as the linear velocity of the magneto-optical disk 16 increases, the magneto-optical disk 1
6 is suitable for recording at a high linear velocity because the flying height with respect to 6 is increased. However, this floating method has the following problems.

FIG. 14 shows the relationship between the linear velocity of the magneto-optical disk 16 and the flying height of the magnetic field modulation head 25. For example, when recording at a low linear velocity such as a linear velocity of 5 m / s, the flying height of the magnetic field modulation head 25 is only about 5 μm, and the flying attitude of the magnetic field modulation head 25 becomes unstable. Depending on how the magnetic field modulation head 25 is mounted, the magneto-optical disk 16
May also come into contact with

When the linear velocity is 3 m / s or less, the magnetic field modulation head 25 does not fly in most cases.
It is not suitable for recording at a low linear velocity, such as recording of digital voice. At the start of rotation of the magneto-optical disk 16 and immediately before the stationary state, the air bearing surface 28 of the mirror-finished head core holding portion 27 and the magneto-optical disk surface come into contact with each other. Problems such as generation of scratches on the surface and sticking of both.

[0016]

As described above, in the conventional magnetic field modulation head, the sliding method is suitable for recording at a low linear velocity on a magneto-optical disk, and the dynamic pressure floating is used for recording at a high linear velocity. The method is suitable. However, when recording is performed on a magneto-optical disk at two or more different linear velocities by using one of the methods, for example, a format for recording a signal at a linear velocity of 10 m / s and a linear velocity of 1.4 m / s. In the case of recording with the same type of magnetic field modulation head,
It may not be possible to respond.

In view of the above, the present invention provides a magnetic field modulation head capable of recording on a magneto-optical disk in both low linear velocity and high linear velocity modes, and magneto-optical recording using this magnetic field modulation head. It is an object to provide a medium recording device.

[0018]

According to the first object of the present invention, a sliding surface for sliding on a surface facing a magneto-optical recording medium is provided. And an air bearing surface for maintaining a floating state at a predetermined distance with respect to the recording medium, and having the same height as the air bearing surface.
The head core is embedded in the surface and this head
The sliding surface protruding from the head core surface near both sides of the core
The air bearing is provided outside the sliding surface.
This is achieved by a field-modulated head provided with a surface .

Further , the above object is achieved according to the invention of claim 2.
For example , a surface facing the magneto-optical recording medium includes a sliding surface for sliding against the recording medium, and an air bearing surface for maintaining a floating state at a predetermined distance with respect to the recording medium, And a head flush with the air bearing surface.
And the air bearing surface
The sliding surface is provided outside the head core from the head core surface.
And the air bearing surface is
Through the head core so as to sandwich the head core.
This is achieved by the magnetic heads arranged on both sides of the magnetic head.

According to a third aspect of the present invention, there is provided a magnetic field modulation head.
In a magneto-optical recording medium recording apparatus in which recording is performed on a magneto-optical recording medium using a magnetic field modulation method, a pressing unit capable of changing a force for pressing the magnetic field modulation head in the direction of the magneto-optical recording medium in a plurality of stages, A magnetic field modulation having, on a surface facing a magneto-optical recording medium, a sliding surface for sliding the recording medium and an air bearing surface for maintaining a floating state at a predetermined distance from the recording medium. and a head, as the magnetic field modulation head, according to claim 1 or 2 Neu
A magnetic head according to any one of the above aspects is provided.

[0021]

[0022]

According to the above arrangement, at the time of recording, at a low linear velocity, in the case of the sliding method, the sliding surface comes into contact with the disk. Therefore, even at a low linear velocity, the distance between the head core and the disk can be appropriately maintained. In the case of a high linear velocity, the air bearing surface functions by the dynamic pressure levitation method, and the magnetic head is floated at an appropriate flying height by the dynamic pressure generated between the magnetic head and the disk. Will be.

In this case, even at the time of high linear velocity recording, at the start of rotation of the magneto-optical disk and immediately before stopping, the sliding surface having a low friction coefficient comes into contact with the magneto-optical disk surface, and the air bearing surface and the magneto-optical disk surface. Since there is no direct contact between the air bearing surface and the disk surface, there is no generation of scratches on the air bearing surface and the disk surface, and no sticking of both.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of the present invention will be described below in detail with reference to FIGS. In addition, since the Examples described below are preferred specific examples of the present invention, various technically preferable limitations are given. However, the scope of the present invention particularly limits the present invention in the following description. The embodiment is not limited to these embodiments unless otherwise stated.

FIGS. 1 and 2 show an embodiment of the magnetic field modulation head of the present invention. 1 and 2, Ca
A mirror-finished air bearing surface 31 is provided on the side of the head core holding portion 30 made of lcium-Titanate ceramic facing the magneto-optical disk surface. At the center of the air bearing surface 31, two rails 32 for efficiently generating dynamic pressure generated by rotation of the magneto-optical disk are formed so as to be elongated in the linear velocity direction. A notch 33 is provided at an end of the air bearing surface 31 in the traveling direction of the magneto-optical disk,
A ferrite head core 34 is embedded and bonded in the notch 33 so that the tip is at the same height as the air bearing surface.

As shown in FIGS. 1 and 2, the head core 3
On both sides of No. 4, a polyacetal (for example, 3% by weight) containing silicon oil having a friction coefficient sufficiently low with respect to the magneto-optical disk at a height close to the magneto-optical disk by a few μm from the tip of the head core 34 ( A sliding surface 35 made of POM) material is provided.

The head core holder 30 has a surface opposite to the magneto-optical disk fixed to one end of a head suspension 36. The head core holder 30 is a suspension 3
6 is coupled to a posture control mechanism 38 attached to an optical pickup base 37 holding the optical pickup.

The attitude control mechanism 38 can be configured by mounting a spring on the optical pickup base 37 and mounting and fixing the other end of the head suspension 36 on the spring, for example. By applying a load from one direction, for example, from the top in the drawing, the position of the head suspension 36 in the vertical direction with respect to the other end of the head suspension 36 can be changed. Thus, by adjusting the weight, the distance between the head core holder 30 disposed at one end of the head suspension 36 and the magneto-optical disk can be controlled.

This embodiment is configured as described above, and the specific operation is as follows. FIG. 3 shows the positional relationship between the magnetic field modulation head and the magneto-optical disk during high linear velocity recording. At the time of high linear velocity recording, the magnetic field modulation head of this embodiment basically performs recording by a dynamic pressure method. For example, when the magneto-optical disk is rotating at a high linear velocity of 10 m / s, the head core holder 30 floats due to the dynamic pressure generated between the magneto-optical disk and the air bearing surface 31.

Here, by slightly moving the attitude control mechanism 38 in the direction of arrow A, the sliding surface 35 of the head core holder 30 can be stably levitated from the magneto-optical disk surface with a constant appropriate floating amount. Can be. For example, the spacing between the head core 34 and the magneto-optical disk surface is controlled to a constant value of about 10 μm in a state where the sliding surface 35 of the head core holding portion 30 is separated from the magneto-optical disk surface. Is performed with high accuracy.

In particular, in this embodiment, since the rail 34 is provided so as to extend in the linear velocity direction with the head core 34 interposed therebetween, the flow of air by dynamic pressure can be efficiently guided in the linear velocity direction. The head core holding unit 30 can maintain a stable floating amount by that much. Moreover, in the present embodiment, the sliding surface 35 is provided at the end of the air bearing surface 31 and is provided sufficiently away from the head core 34 and the rail 34. Does not impede flow.

FIG. 4 shows the positional relationship between the magnetic field modulation head and the magneto-optical disk during low linear velocity recording. When the magneto-optical disk is stationary or when the magneto-optical disk is rotating at a low linear velocity, the attitude control mechanism 38 is slightly moved in the direction of the magneto-optical disk (the direction of arrow B) by increasing the weight, for example. Control is performed so that the sliding surface 35 and the magneto-optical disk surface always maintain a contact state. As a result, the spacing between the head core 34 and the surface of the magneto-optical disk is controlled to a constant value of about several μm.

When the sliding surface 35 is in contact with the surface of the magneto-optical disk, the air bearing surface 31 is always slightly above the sliding surface 35 in the figure. Therefore, at the time of low linear velocity recording as in the past,
The air bearing surface 31 does not come into contact with the surface of the magneto-optical disk and is not damaged. In addition, the sticking between the air bearing surface 31 and the surface of the magneto-optical disk at the start of rotation of the magneto-optical disk or immediately before the stationary state is effectively prevented.

As described above, according to the magnetic field modulation head of this embodiment, the spacing control method suitable for the linear velocity is adopted in both the cases of the low linear velocity recording and the high linear velocity recording. Therefore, the head core does not contact the magneto-optical disk surface during recording, and the distance between the head core and the magneto-optical disk surface can always be controlled to 50 μm or less.

FIG. 5 shows another embodiment of the magnetic field modulation head of the present invention. As in the embodiment shown in FIG. 1, a mirror-finished air bearing surface 31 is provided on the side of the head core holding portion 30 facing the magneto-optical disk surface. At the center of the air bearing surface 31, the head core 3
A sliding surface 35 similar to that of the embodiment shown in FIG. 1 is formed in a range that does not hinder the dynamic pressure floating effect on both sides of No. 4. Two rails 32 for generating a dynamic pressure effect are provided on the sliding surface 3.
5, and the other configuration is the same as that of the above-described embodiment. Therefore, the magnetic field modulation head of this embodiment employs a spacing control method suitable for the linear velocity both in the case of low linear velocity recording and in the case of high linear velocity recording, as in the above-described embodiment. can do. Then, the head core does not contact the magneto-optical disk surface during recording, and the distance between the head core and the magneto-optical disk surface can always be controlled to 50 μm or less.

FIG. 6 shows another embodiment of the magnetic field modulation head of the present invention. In this magnetic field modulation head, the sliding surface 35 and the air bearing surface 31 are integrally formed of the same POM material with respect to the embodiment of FIG. In this case, only the air bearing surface is processed to have a surface roughness of 0.1 μm or less. Other configurations are the same as those of the above-described embodiment. Therefore, the magnetic field modulation head of this embodiment employs a spacing control method suitable for the linear velocity both in the case of low linear velocity recording and in the case of high linear velocity recording, as in the above-described embodiment. can do. And
During recording, the head core does not contact the magneto-optical disk surface, and the distance between the head core and the magneto-optical disk surface can always be controlled to 50 μm or less.

[0037]

As described above, according to the magnetic field modulation head of the present invention, a magnetic field modulation head capable of recording on a magneto-optical disk in both low linear velocity and high linear velocity modes and its magnetic field A magneto-optical recording medium recording device using a modulation head can be provided.

[Brief description of the drawings]

FIG. 1 is a front view showing an embodiment of a magnetic field modulation head according to the present invention.

FIG. 2 is a bottom view showing one embodiment of the magnetic field modulation head of the present invention.

FIG. 3 is a diagram showing a positional relationship between a magnetic field modulation head and a magneto-optical disk during high linear velocity recording according to the present invention.

FIG. 4 is a diagram showing a positional relationship between a magnetic field modulation head and a magneto-optical disk during low linear velocity recording according to the present invention.

FIG. 5 is a schematic view showing another embodiment of the magnetic field modulation head of the present invention.

FIG. 6 is a schematic view showing another embodiment of the magnetic field modulation head of the present invention.

FIG. 7 is a schematic view showing a conventional magnetic field modulation head.

FIG. 8 is a diagram showing a relationship between a distance from a tip of a core 10 of a conventional magnetic field modulation head and a magnetic field strength.

FIG. 9 is a front view showing a magnetic field modulation head used in a conventional sliding method.

FIG. 10 is a bottom view showing a magnetic field modulation head used in a conventional sliding method.

FIG. 11 is a sectional view showing a magnetic field modulation head used in a conventional sliding method.

FIG. 12 is a front view showing a magnetic field modulation head used in a conventional dynamic pressure levitation method.

FIG. 13 is a bottom view showing a magnetic field modulation head used in a conventional dynamic pressure levitation method.

FIG. 14 is a diagram showing the relationship between the linear velocity of a conventional magneto-optical disk and the flying height of a magnetic field modulation head.

[Explanation of symbols]

 31 air bearing surface 34 head core 35 sliding surface 38 attitude control mechanism

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G11B 11/105 G11B 21/21 G11B 5/02

Claims (3)

(57) [Claims] A sliding surface for sliding the recording medium on a surface facing the magneto-optical recording medium; and an air bearing surface for maintaining a floating state at a predetermined distance from the recording medium. And the head core is flush with the air bearing surface.
Is embedded and near both sides of this head core.
The sliding surface is provided so as to protrude from the head core surface.
Wherein the air bearing surface is provided outside the sliding surface . 2. A sliding surface for sliding with respect to a magneto-optical recording medium on a surface facing the magneto-optical recording medium, and an air bearing surface for maintaining a floating state at a predetermined distance from the recording medium. And the head core is flush with the air bearing surface.
Is embedded and outside the air bearing surface
The sliding surface is provided so as to protrude from the head core surface, and the air bearing surfaces are respectively interposed by rails.
Then, the head core is sandwiched between the head cores.
A magnetic head, which is arranged on both sides . 3. A magnetic field modulating method using a magnetic field modulating head.
A magneto-optical recording medium recording apparatus for performing recording on a magneto-optical recording medium by using a pressing means capable of changing a force for pressing the magnetic field modulation head in the direction of the magneto-optical recording medium in a plurality of stages; A magnetic field modulation head provided with a sliding surface for sliding against the recording medium, and an air bearing surface for maintaining a floating state at a predetermined distance with respect to the recording medium, 3. The magnetic field modulation head according to claim 1, wherein:
A magneto- optical recording medium recording device , comprising the magnetic head according to any one of the above .