JP2844867B2 - Floating head of magneto-optical recording device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a floating head of a magneto-optical recording device, and more particularly, to efficiently forming a perpendicular magnetic field toward a converging point of converged light on an optical recording medium. The present invention relates to a floating head which can be improved.

[Prior Art] To explain the recording principle of this type of magneto-optical recording apparatus, a magnetic field in the direction of the arrow is applied to a recording film (a) made of a magnetic material as shown in FIG. 16 (A). In this state, the laser spot is irradiated, the magnetization direction of the irradiated area is reversed to change the Kerr rotation angle, and the change in the Kerr rotation angle is used to record / reproduce information (see FIG. 16 (B)). )
On the other hand, as shown in FIG. 16 (C), a laser spot is irradiated on the recording portion of the recording film (a) in a state where the direction of the magnetic field is reversed, and the magnetization direction of the irradiated portion is recorded. This is a method of erasing information by returning to the previous state.

Incidentally, an optical head for recording, reproducing, and erasing information in this magneto-optical recording type recording apparatus is disclosed in
A floating head described in -261052 is known.

That is, as shown in FIGS. 17 to 19, the floating head (b) is made of a soft magnetic material and floats by an air flow accompanying rotation of the optical recording medium (c). A prism (b2) attached to the air slider (b1) and reflecting laser light from a light source (d) such as a semiconductor laser toward the optical recording medium (c); and an optical path opening (b3) of the air slider (b1). An objective lens (b4) mounted on the optical disc and converging the laser beam reflected by the prism (b2) on a converging surface of the optical recording medium (c); and an optical path for the optical path on the optical recording medium (c) side of the air slider (b1). Opening (b3)
A coil (b) wound around a groove (b5) provided along the axis and forming a magnetic field substantially perpendicular to the converging surface of the optical recording medium (c)
6) and its main part is supported by a spring-like suspension (b7) that is operated to move in the radial direction of the optical recording medium (c) by a driving device (e), and the vicinity of the optical recording medium (c) It is arranged in.

In the floating head (b), only the minimum members such as the prism (b2), the objective lens (b4), and the coil (b6) are mounted on the air slider (b1).
It has the advantage that the head can be reduced in weight and the access time can be reduced, and the air slider (b1) is made to float by the air flow accompanying the rotation of the optical recording medium (c). This has the advantage that the distance between (c) and the air slider (b1) can be kept constant, and the focusing mechanism of the objective lens (b4) can be omitted.

[Problems to be Solved by the Invention] Incidentally, in this type of floating head (b), since the entire air slider (b1) is made of a soft magnetic material as described above, FIGS. As shown in the figure, the air slider (b1) sandwiching the coil (b6)
Since the magnetic path is formed on the side of the optical path opening (b3) and the outside area of the optical recording medium (c3), it is difficult to concentrate the generated magnetic field toward the convergence point (α) of the laser beam on the optical recording medium (c) through the air. There was a disadvantage.

For this reason, in order to form a magnetic field of 200 to 3000 e required for magneto-optical recording or erasing on the converging surface of the optical recording medium (c), it is necessary to apply a very large supermagnetic force,
Conventionally, this has been dealt with by increasing the number of turns of the coil (b6).

However, when the number of turns of the coil (b6) is increased, the self-inductance also increases, so that the direction of the magnetic field cannot be reversed at a high speed when recording or erasing information, and the recording or rewriting speed decreases. was there.

In Japanese Patent Application Laid-Open No. 61-71437, a soft magnetic layer is provided on the lower surface side of the recording film of the optical recording medium, and a magnetic path is formed between the soft magnetic layer and the coil to improve the concentration of the perpendicular magnetic field. However, since the magnetic field cannot be concentrated toward the convergence point of the laser beam on the optical recording medium, it has not been sufficient.

[Means for Solving the Problems] The present invention has been made by focusing on the above problems, and an object of the present invention is to efficiently form a vertical magnetic field toward a convergence point of converged light in an optical recording medium. To provide a floating head that can be used.

That is, the invention according to claim 1 includes a floating body which is arranged near a rotating optical recording medium and floats by an air flow accompanying the rotation of the optical recording medium, and which is attached to an opening for an optical path of the floating body and receives light from a light source. An objective lens for converging the converged light on the converging surface of the optical recording medium; and a magnetic field generating means attached near the optical path opening of the floating body for forming a magnetic field toward the converging surface of the optical recording medium. Assuming a floating head of a magneto-optical recording device for recording or erasing information by converging the converged light on a converging surface of an optical recording medium in a state where a magnetic field is formed by a generating means, The magnetic flux concentrating portion made of a soft magnetic material near the opening edge of the optical path opening on the optical recording medium side is equal to or smaller than the dimension along the optical path direction of the magnetic field generating means. On the other hand, the invention according to claim 2 is arranged near a rotating optical recording medium and floats by an air flow accompanying rotation of the optical recording medium. A floating body; an objective lens attached to the optical path opening of the floating body for converging a converged light from a light source on a convergence surface of the optical recording medium; and an optical recording medium attached near the optical path opening of the floating body. A magnetic field generating means for forming a magnetic field toward the convergence surface of the optical recording medium, and a light for recording or erasing information by converging the converged light on the convergence surface of the optical recording medium in a state where the magnetic field is generated by the magnetic field generating means. Assuming a floating head of a magnetic recording type recording apparatus, the floating body is fitted with a cylindrical inner body formed of a soft magnetic material and provided with an opening for an optical path, and the inner body formed of a non-magnetic material. Outer book A magnetic flux concentrating portion formed of a soft magnetic material having a transmittance higher than that of the inner main body in the vicinity of the optical recording medium side opening edge of the optical path opening along the optical path direction of the magnetic field generating means. The size is set to be equal to or smaller than the size.

In the invention according to claim 1, as the non-magnetic material constituting the floating body, glassy carbon, barium titanate, calcium titanate, ceramics and the like can be applied. When the floating body is made of a non-magnetic material such as calcium titanate or ceramics, it has an advantage that its workability is good, and it has a lubricating non-magnetic material such as glassy carbon. In the case where the floating body is configured by the above, there is an advantage that the wear phenomenon of the floating body and the optical recording medium at the time of contact with each other can be reduced.

Further, the magnetic flux concentrated portion provided near the opening edge of the optical path opening needs to be formed of a soft magnetic material such as Mn-Zn ferrite, Ni-Zn ferrite, sendust, and permalloy. In this case, the magnetic flux concentration portion may be constituted by a single soft magnetic material, or may be constituted by a plurality of soft magnetic materials.
When the magnetic flux concentrating portion is formed by laminating a plurality of soft magnetic materials, the material group should be selected so that the magnetic permeability of the magnetic flux concentrating portion gradually increases as approaching the convergence point of the optical recording medium. Is desirable.

On the other hand, in the invention according to claim 2, the Mn-Zn ferrite or Ni-Zn is used as the inner body in order to easily concentrate a magnetic field on the optical path opening provided in the inner body.
It must be made of a soft magnetic material such as ferrite, sendust, and permalloy. The shape of the inner main body is not particularly limited, but it is preferable to match the shape of the opening for the optical path so that a uniform magnetic field can be formed on the side of the opening for the optical path.

Also, as the outer body into which this inner body is fitted,
In order to reduce the formation of a magnetic path on the outer body side and to easily concentrate the magnetic field on the optical path opening side, a nonmagnetic material such as the glassy carbon, barium titanate, calcium titanate, and ceramics is used. It is necessary to configure this.

Furthermore, there is no particular limitation on the method of fitting the inner body to the outer body, and the inner body may simply be fitted to the fitting portion of the outer body, or an adhesive may be interposed between these fitting surfaces. It may be fitted and inserted.

Further, the magnetic flux concentration portion provided near the opening edge of the optical path opening needs to be formed of a soft magnetic material having a higher magnetic permeability than the inner main body. That is, Mn
-Zn ferrite, Ni-Zn ferrite, Sendust, and the above soft magnetic materials such as Permalloy, when arranged in descending order of magnetic permeability, generally in the order of Permalloy>Sendust> Mn-Zn ferrite = Ni-Zn ferrite I have. Therefore, for example, when the inner body is made of a soft magnetic material such as Mn-Zn ferrite or Ni-Zn ferrite, the magnetic flux is made of a soft magnetic material such as Sendust or Permalloy having a higher magnetic permeability than these materials. This constitutes a centralized part.

The magnetic flux concentration portion may be made of a single soft magnetic material as in the first aspect of the present invention,
Alternatively, this may be constituted by a plurality of soft magnetic materials, and when the above-mentioned magnetic flux concentration portion is constituted by laminating a plurality of soft magnetic materials, the magnetic flux becomes closer as the convergence point of the optical recording medium approaches. It is desirable to select the above-mentioned material group so that the magnetic permeability of the concentrated portion is sequentially increased.

Next, in the invention according to claims 1 and 2, at least a gliding surface and an air introduction surface are formed on the bottom side of the floating main body so as to efficiently receive a floating pressure from an optical recording medium. Cost. Further, a concave groove for allowing air to escape along the length direction of the floating body, that is, a central relief portion may be formed for the purpose of stabilizing the floating traveling of the floating body.
In this case, the number and shape of the concave grooves can be arbitrarily set according to the purpose.

Further, in these inventions, the shape of the opening for the optical path is formed in a substantially circular shape in accordance with the shape of the focused light spot, but when the inner wall of the opening for the optical path is provided with a gradient toward the inside of the incident direction of the focused light, Since the magnetic field generating means attached near the optical path opening and the convergence point of the converged light in the optical recording medium can be made closer, the magnetic field can be more concentrated toward the convergence surface of the optical recording medium. Has advantages. In particular, when the inclination angle of the inner wall surface of the opening for the optical path is set to be substantially the same as the converging angle of the converged light, the magnetic field generating means and the convergent point can be brought closest to each other, so that the effect is remarkable.

Further, at least the optical recording medium side in the optical path opening may be filled with a transparent filler made of a resin such as PMMA or a light transmitting material such as glass such as Corning 7059. When such a filler is filled, the bottom surface side of the opening for the optical path is closed so that floating traveling is stabilized, and also the following advantages are provided. That is, the optical system of the floating head in the magneto-optical recording device generally uses the optical system of the floating head in the phase change recording device. However, in this phase change type recording apparatus, usually, a method of irradiating a focused light from the transparent substrate side of the optical recording medium and converging the focused light to the recording film surface to perform recording / erasing is adopted. An objective lens having a focal length in consideration of the refractive index of the transparent substrate is used. In contrast,
In a magneto-optical recording type recording device, it is necessary to form a strong magnetic field on the recording film surface of the optical recording medium. Therefore, a method of directly converging the focused light on the recording film surface without using a method of irradiating the focused light from the substrate side is required. When the objective lens is applied to a floating head of a magneto-optical recording device as it is,
Focused light may not be properly converged on the recording film surface.
In such a case, the optical path opening is filled with a transparent filler composed of a light transmissive material having substantially the same refractive index as that of the transparent substrate, so that the focused light is focused on the recording film surface of the optical recording medium. Can be appropriately converged.

Next, in these inventions, the mounting position of the magnetic field generating means such as a coil is arbitrary as long as it is near the optical path opening. For example, in the invention according to claim 1, the floating body is provided along the optical path opening. The mounting groove may be formed in the mounting groove, or the mounting groove may be provided in the mounting groove, or may be mounted on the inner wall surface of the opening for the optical path. It may be provided, or may be attached to the inner wall surface of the optical path opening of the inner body. However, in order to more efficiently concentrate the magnetic field toward the converging surface of the optical recording medium, it is preferable that both of them are mounted on the inner wall surface of the optical path opening. When the magnetic field generating means is mounted on the inner wall surface of the optical path opening, a stopper may be appropriately attached to the lower end of the optical path opening in order to prevent the magnetic field generating means from falling off the optical path opening.

Further, in the invention according to claim 1, both the mounting groove and the inner wall surface of the optical path opening are provided, whereas in the invention according to claim 2, the inner body is provided on the inner wall surface of the optical path opening and the side adjacent to the outer body. Magnetic field generating means may be attached to both of the outer peripheral surfaces. In such a configuration, the magnetic field generated by the magnetic field generating means mounted on the inner wall surface of the opening for the optical path and the magnetic field generated by the magnetic field generating means mounted on the outer peripheral surface on the side adjacent to the mounting groove or the outer body. Interfere with each other, and a uniform magnetic field having a uniform intensity can be uniformly formed on the converging surface of the optical recording medium and its peripheral region. Therefore, even if the convergence point of the converged light slightly shifts due to the surface deflection of the optical recording medium or the like, there is an advantage that the recording or erasing operation of the information is not hindered.

Note that a prism, a reflection mirror, and the like can be used as in the related art as the reflection member that reflects the condensed light from the light source toward the optical recording medium.

According to the first aspect of the present invention, the floating main body is made of a non-magnetic material, and the magnetic flux concentrating portion made of a soft magnetic material is formed near the optical recording medium side opening edge of the optical path opening. Since the size of the magnetic field generating means is set to be equal to or smaller than the dimension along the optical path direction, it is possible to reduce the formation of a magnetic path on the floating body side made of a nonmagnetic material. The magnetic flux concentrates on the magnetic flux concentrating portion, so that the magnetic field can be concentrated toward the convergence point of the converged light in the optical recording medium. On the other hand, according to the invention according to claim 2, the floating body is A cylindrical inner main body formed of a soft magnetic material and provided with an optical path opening, and an outer main body formed of a non-magnetic material and fitted with the inner main body. Open the recording medium Since the magnetic flux concentration portion made of a soft magnetic material having a higher magnetic permeability than the inner body near the edge is provided so as to have a size equal to or smaller than the size along the optical path direction of the magnetic field generating means, The formation of a magnetic path on the outer body side made of a non-magnetic material can be reduced, and the magnetic flux concentrates on the magnetic flux concentrating portion, so that the magnetic field is directed toward the convergence point of the converged light in the optical recording medium. Can be concentrated.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

◎ First Embodiment This embodiment is one in which the invention according to claim 1 is applied.

In other words, the floating head (1) according to this embodiment has a spring-shaped suspension (2) as shown in FIGS.
The floating body (10) supported by
A coil (5) as a magnetic field generating means wound in the mounting groove (13) of (0), an objective lens (12) and a prism provided in the optical path opening (6) of the floating body (10). (11) and a magnetic flux concentrating portion (14) provided at the opening of the optical path opening (6) constitute a main part thereof.

First, the floating body (10) is made of glassy carbon, and as shown in FIG. 1, tapers (16) (17) for smoothly flowing air into and out of the air inflow end and air outflow end on the bottom side. ), And a central relief portion (18) for stabilizing the floating traveling of the floating head (1) as shown in FIG.

In addition, in the approximate center of the floating body (10), FIGS.
As shown in the figure, a laser beam (λ) from a semiconductor laser (7), which is a light source, is introduced into the magneto-optical disk (8), and the inner wall surface of the laser beam (λ) is directed inward in the direction of incidence of the laser beam (λ). An optical path opening (6) having substantially the same gradient as the converging angle of the laser light (λ) is opened, and the optical path opening (6) is formed at the opening of the optical magnetic disk (8) side. Is laminated and provided around the inner wall surface and the opening edge.
A magnetic flux concentration portion (14) made of Mn-Zn ferrite is formed.

On the other hand, above the optical path opening (6) of the floating body (10), a laser beam (λ) from a semiconductor laser (7) made of a glass material such as BK7 is applied to the magneto-optical disk (8) side. A prism (11) that reflects light toward the prism is mounted, and an objective lens (12) is fitted and mounted on the side of the optical path opening (6) adjacent to the prism (11).

Then, the distal end side of the spring-shaped suspension (2) whose base end side is attached to the driving device (9) is attached to the attachment concave portion (19) of the floating body (10), and the floating head (1) according to this embodiment is mounted. ) Are arranged at predetermined positions. The driving device (9) is composed of a voice coil motor or the like, and is mounted on a spring-like suspension (2) based on a control signal such as a tracking error signal input to the driving device (9). The movement of the head (1) is controlled on a predetermined track of the magneto-optical disk (8).

In the floating head (1) thus configured, the floating body (10) has a thickness of 1 μm with the rotation of the magneto-optical disk (8).
A laser beam (λ) which flies to the extent and which is applied to the surface of the prism (11) of the floating head (1) in parallel with the moving direction of the driving device (9) as shown in FIGS. Is incident and converged on the converging surface of the magneto-optical disk (8) via the objective lens (12), while being transmitted to the coil (5) wound in the mounting groove (13) of the floating body (10). Upon energization, a perpendicular magnetic field of 200 to 300 Oe (that is, a magnetic field parallel to the optical axis of the laser light) is applied from the coil (5) to the converging surface of the magneto-optical disk (8), and a recording operation is performed. Alternatively, the laser beam (λ) reflected from the surface of the magneto-optical disk (8) is incident on a photodiode (not shown) through the same optical path to perform a reproducing operation.

In the floating head (1) according to this embodiment, since the floating body (10) is made of glassy carbon which is a nonmagnetic material, a magnetic path is formed on the floating body (10) side. As a result, the magnetic field can be concentrated toward the converging surface of the magneto-optical disk (8) as shown in FIG. 4 (A). Since the opening has a magnetic flux concentration portion (14) made of Mn-Zn ferrite, which is a soft magnetic material, the magnetic flux from the coil (5) is generated by the magnetic flux as shown in FIG. 4 (B). I started to concentrate on the concentration section (14)
Convergence point (α) of laser light on magneto-optical disk (8)
To concentrate the magnetic field.

Therefore, without applying a large supermagnetic force as in the past,
Since a magnetic field of 200 to 300 Oe required for magneto-optical recording or erasing can be formed on the converging surface of the magneto-optical disk (8), the number of turns of the coil (5) mounted on the floating head (1) and The supply current can be reduced.

For this reason, the self-inductance of the coil (5) mounted on the floating head (1) is reduced, and the direction of the magnetic field can be reversed at a high speed when recording or erasing information, and the recording or rewriting speed increases. Has advantages.

FIG. 5 is a graph showing the relationship between the magnetomotive force of the coil mounted on the floating head and the relative magnetic field strength formed on the converging surface of the magneto-optical disk. In the floating head according to the present invention, it takes about one-half to obtain the desired magnetic field strength as compared with the conventional floating head indicated by a broken line.
It can be confirmed that the magnetic field direction can be reversed at a high speed while maintaining the magnetic field strength of 200 to 300 Oe.

In this embodiment, the optical path opening (6) is used.
Is provided with a gradient substantially the same as the converging angle of the laser beam (λ), but it is natural that the invention according to claim 1 is applied to a floating head having no gradient as shown in FIG. Good thing.

◎ Second Embodiment This embodiment is one in which the invention according to claim 2 is applied.

That is, the floating head (1) according to this embodiment is provided with a spring-shaped suspension (2) as shown in FIGS.
Outer body (3) supported by the above, a cylindrical inner body (4) fitted into the outer body (3), and an optical path opening (6) provided at the opening edge of the inner body (4). The main part of the magnetic flux concentrating part (41) is constituted.

First, the outer main body (3) is made of glassy carbon, and is provided with a taper (31) at the air inflow end and air outflow end on the bottom side as shown in FIG. In addition, a central relief portion (33) for stabilizing the floating traveling of the floating head (1) is provided at the central portion on the bottom side. In addition, as shown in FIG. 8, the inner main body (4)
A mounting opening (34) for mounting the inner body (4) is formed, and a gradient corresponding to the outer shape of the inner main body (4) is formed on the inner peripheral surface of the mounting opening (34). 7) At the lower part of the inner peripheral surface, as shown in FIG.
6) is provided.

On the other hand, the inner main body (4) is formed of a cylindrical Mn-Zn ferrite, and has a mounting opening (3) of the outer main body (3).
4) is fitted and arranged via an adhesive, and the inside of the cylindrical shape is configured as an optical path opening (6) having substantially the same gradient as the converging angle of the laser beam (λ), In addition, the Mn-Zn ferrite which is provided in the opening of the optical path opening (6) on the side of the magneto-optical disk (8) and is laminated around the inner wall surface and the periphery of the opening to form the inner main body (4) has a higher transparency. A magnetic flux concentration part (41) made of permalloy having a high magnetic susceptibility is formed.

A coil (5) is wound and disposed in the mounting groove (36) of the outer body (3), and a glass material such as BK7 is provided on the upper surface of the inner body (4). (11) for reflecting the laser light from the semiconductor laser configured to the magneto-optical disk (8) side is attached,
An objective lens (12) is fitted and attached to a side of the inner body (4) adjacent to the prism (11) in the optical path opening (6).

Then, as in the first embodiment, the distal end of a spring-like suspension (2) whose base end is attached to a driving device is attached to the outer body (3), and the floating head (1) is disposed at a predetermined position. Is what is being done.

In the floating head (1) thus configured, the floating body (10) composed of the outer body (3) and the inner body (4) floats about 1 μm with the rotation of the magneto-optical disk (8). Laser light (λ) is incident on the prism (11) surface of the floating head (1) and is converged on the converging surface of the magneto-optical disk (8) via the objective lens (12). Mounting groove (36) of outer body (3) below 12)
When the coil (5) is turned on, the coil (5) is moved toward the converging surface of the magneto-optical disk (8) from the coil (5).
A perpendicular magnetic field of up to 300 Oe is applied to perform a recording operation, or a reflected laser beam (λ) from the surface of the magneto-optical disk (8) enters the photodiode through the same optical path to perform a reproducing operation. Things.

In the floating head (1) according to this embodiment, the floating body (10) is formed of Mn-Zn ferrite and has an inner body (4) provided with an optical path opening (6).
And an outer body (3) formed of glassy carbon and into which the inner body (4) is fitted, so that a magnetic path is formed on the outer body (3) side made of a non-magnetic material. And the magnetic field can be concentrated toward the converging surface of the magneto-optical disk (8) as shown in FIG. 9 (A), and the optical path opening (6) can be further reduced. The inner body (4) at the opening
Since a magnetic flux concentrating portion (41) made of permalloy having a higher magnetic permeability than Mn-Zn ferrite is provided, the magnetic flux from the coil (5) as shown in FIG. ), And the magnetic field can be more concentrated toward the laser beam convergence point (α) on the magneto-optical disk (8).

Therefore, a magnetic field of 200 to 300 Oe required at the time of magneto-optical recording or erasing can be formed on the converging surface of the magneto-optical disk (8) without giving a large magnetomotive force as in the prior art. The number of turns and supply current of the coil (5) mounted in 1) can be reduced.

For this reason, the self-inductance of the coil (5) mounted on the floating head (1) is reduced, and the direction of the magnetic field can be reversed at a high speed when recording or erasing information, and the recording or rewriting speed increases. Has advantages.

In this embodiment as well, the optical path opening (6) has a gradient substantially the same as the converging angle of the laser beam (λ), but the gradient is not provided as shown in FIG. It goes without saying that the invention according to claim 2 may be applied to the floating head.

In the first and second embodiments, the coil as the magnetic field generating means is wound and disposed in the mounting groove (13) provided in the floating body (10) or the outer body (3). 11 and may be attached to the inner wall surface of the optical path opening (6) as shown in FIG. 11, or the inner body (4) as shown in FIG.
May be attached to both the inner wall surface and the outer peripheral surface of the inner body (4).

Third Embodiment A floating head according to this embodiment is provided with a PM in a lower part inside an optical path opening (6) of a floating body (10) as shown in FIG.
It is substantially the same as the floating head of the modified example in the first embodiment except that it is filled with a transparent filler (60) made of MA.

The floating head according to this embodiment has the same advantages as the first embodiment, and the magneto-optical disk (8) side of the optical path opening (6) is closed by the transparent filler (60). As a result, the floating traveling of the floating head (1) is stabilized and has the following advantages. That is, the optical system of the floating head in this type of magneto-optical recording device generally uses the optical system of the floating head in the phase change recording device. However, in this phase change recording apparatus, as shown in FIG. 15, a laser beam (λ) is usually irradiated from the transparent substrate (82) side of the optical disk (81), and the recording film (83) surface is irradiated with the laser beam (λ). Since a method of recording / erasing by converging light (λ) is adopted, an objective lens having a focal length in consideration of the refractive index of the transparent substrate (82) is used. Therefore, when this objective lens is directly applied to a floating head of a magneto-optical recording type recording apparatus, the laser beam (λ) may not be appropriately converged on the recording film surface.

Therefore, the transparent substrate (82) is placed in the optical path opening (6).
By filling the transparent filler (60) having the same refractive index as that of (1), the laser beam (λ) passes through the transparent filler (60) onto the recording film (83) of the magneto-optical disk (8). Since the convergence is achieved, there is an advantage that the above-mentioned adverse effects can be eliminated.

In addition, as shown in FIG. 14, a configuration is adopted in which the transparent filler (60) is filled in the optical path opening (6) of the inner body (4) fitted into the outer body (3). Of course it is good.

According to the first aspect of the present invention, the floating body is made of a non-magnetic material, and the magnetic flux concentrating portion is made of a soft magnetic material near the optical recording medium side opening edge of the optical path opening. Is provided so as to have a size equal to or smaller than the dimension along the optical path direction of the magnetic field generating means, so that the formation of a magnetic path on the floating body side made of a non-magnetic material can be reduced. At the same time, the magnetic flux concentrates on the magnetic flux concentrating portion, so that the magnetic field can be more concentrated toward the convergence point of the converged light on the optical recording medium. On the other hand, according to the invention according to claim 2, A cylindrical inner main body formed of a soft magnetic material and provided with an optical path opening, and an outer main body formed of a non-magnetic material and into which the inner main body is fitted. Optical recording medium side Since the magnetic flux concentration portion made of a soft magnetic material having a higher magnetic permeability than the inner body near the opening edge is provided so as to have a size equal to or smaller than the size along the optical path direction of the magnetic field generating means, The formation of a magnetic path on the outer body side made of a non-magnetic material can be reduced, and the magnetic flux concentrates on the magnetic flux concentrating portion, so that the magnetic field is directed toward the convergence point of the converged light in the optical recording medium. Can be concentrated.

Therefore, without giving a large magnetomotive force as in the past,
Since a magnetic field having a strength required at the time of magneto-optical recording or erasing can be formed on the converging surface of the optical recording medium, the number of windings and supply current of a coil or the like mounted on the floating head can be reduced, and recording can be performed. Alternatively, the rewriting speed can be increased.

[Brief description of the drawings]

1 to 14 show an embodiment of the present invention. FIG. 1 is a perspective view of a floating head according to the first embodiment, and FIG.
FIG. 3 is a partial perspective view in which a part of the configuration of the floating head is omitted, FIG. 4 (A) is an explanatory view of the operation of the floating head, and FIG. FIG. 5 is an enlarged view, FIG. 5 is a graph showing the relationship between the magnetomotive force of the coil mounted on the floating head, and the relative magnetic field strength formed on the converging surface of the magneto-optical disk, and FIG. FIG. 7 is a sectional view of a floating head according to a modification, FIG. 7 is a sectional view of the floating head according to the second embodiment, FIG. FIG. 9 (A) is an explanatory view of the operation of the floating head, FIG. 9 (B) is a partially enlarged view thereof,
10 to 12 are cross-sectional views of a floating head according to a modification of the second embodiment, respectively, FIG. 13 is a cross-sectional view of the floating head according to the third embodiment, and FIG. FIG. 15 is a schematic bottom perspective view of an optical disk applied to a phase change recording apparatus, and FIG.
(A) to (C) are explanatory diagrams of the recording principle in a magneto-optical recording device, FIG. 17 is a perspective view of a floating head in a conventional magneto-optical recording device, and FIG. 18 is a partially enlarged perspective view thereof. FIG. 19 is a cross-sectional view taken along the plane XIX-XIX of FIG. 17, FIG. 20 is an explanatory view of the operation of the conventional floating head, and FIG. 21 is a partially enlarged view of FIG. [Description of Signs] (1) Floating head (3) Outer body (4) Inner body (5) Coil (6) Opening for optical path (7) Semiconductor laser (8) … Magneto-optical disk (10)… Floating body (11)… Prism (12)… Objective lens (14) (41)… Magnetic flux concentration part

Continued on the front page (72) Inventor Daisuke Iguchi 2274 Hongo, Ebina-shi, Kanagawa Prefecture Fuji Xerox Co., Ltd.Ebina Office (72) Inventor Kaoru Yasukawa 2274 Hongo, Ebina-shi, Kanagawa Prefecture Fuji Xerox Co., Ltd.Ebina Office (56 References JP-A-62-204456 (JP, A) JP-A-60-261502 (JP, A) JP-A-3-122855 (JP, A) JP-A-3-203051 (JP, A) (58) Field surveyed (Int.Cl. ⁶ , DB name) G11B 11/10

Claims (2)

(57) [Claims] 1. A floating body which is arranged near a rotating optical recording medium and floats by an air flow accompanying the rotation of the optical recording medium, and which is attached to an opening for an optical path of the floating body to converge focused light from a light source. An objective lens for converging on the converging surface of the recording medium; and a magnetic field generating means mounted near the optical path opening of the floating body for forming a magnetic field toward the converging surface of the optical recording medium. In the floating head of the magneto-optical recording type recording device for recording or erasing information by converging the converged light on the converging surface of the optical recording medium in a state where is formed, the floating body is made of a non-magnetic material, and A magnetic flux concentration portion made of a soft magnetic material is provided in the vicinity of the optical recording medium side opening edge of the optical path opening so as to have a size equal to or smaller than a size along the optical path direction of the magnetic field generating means. A floating head of a magneto-optical recording device. 2. A floating body which is arranged in the vicinity of a rotating optical recording medium and floats by an air flow accompanying the rotation of the optical recording medium; An objective lens for converging on the converging surface of the recording medium; and a magnetic field generating means mounted near the optical path opening of the floating body for forming a magnetic field toward the converging surface of the optical recording medium. In the floating head of a magneto-optical recording device for recording or erasing information by converging the converged light on a converging surface of an optical recording medium in a state where the optical recording medium is formed, the floating main body is formed of a soft magnetic material for an optical path. A cylindrical inner body provided with an opening, and an outer body formed of a non-magnetic material and into which the inner body is fitted,
The magnetic flux concentrating portion made of a soft magnetic material having a transmittance higher than that of the inner main body in the vicinity of the optical recording medium side opening edge of the optical path opening is equal to or larger than the dimension along the optical path direction of the magnetic field generating means. A floating head for a magneto-optical recording device, wherein the floating head is provided to have a smaller size.