JP2001067715A - Magneto-optical disk device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the S/N ratio of a signal in recording or reproducing desired information from depending on the direction of a rotary mirror installed on the rotary axial center of a swing arm, by nearly circularly polarizing a laser beam that enters from a fixed optical system to a movable optical system having the swing arm. SOLUTION: A fixed optical system 7 makes a parallel beam, with a collimator lens 19, from a linearly polarized laser beam generated by a laser light source 20, forming a desired cross sectional shape, e.g. a circle, with a prism 18, circularly polarizing the beam with a λ/4 wavelength plate 12, and making it enter a rotary mirror 6 in a movable optical system 21 through a mirror 16. The circularly polarized laser beam is symmetrical in the polarizing characteristics around the optical axis and, when reflected by a rotary mirror 6 rotating around the optical axis, its reflectance is not dependent on the direction of the rotary mirror 6. As a result, in recording or reproducing desired information on a magneto-optical disk 8, the S/N ratio of a signal is free from dependence on the direction of the rotary mirror 6, permitting a stable operation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magneto-optical disk drive equipped with a solid-state immersion lens, and more particularly, a laser light source is fixed to a magneto-optical disk drive, and the solid-state immersion lens uses a swing arm to store information such as an optical disk. The present invention relates to a magneto-optical disk drive device positioned on a recording medium.

[0002]

2. Description of the Related Art In the field of information recording, various technological innovations for high-density recording have been observed today.

As a method of high-density recording proposed as one of these techniques, a lens capable of generating an evanescent wave (hereinafter, referred to as a solid immersion lens) is used.
Was used. In this method, an evanescent wave generated by totally reflecting light in a solid immersion lens is used.

Since the evanescent wave generated by the solid immersion lens exists as a minute light spot, the recording density of information on a recording medium such as a magneto-optical disk could be increased.

A conventional magneto-optical disk drive using this solid immersion lens is disclosed in, for example,
No. 162444.

FIG. 13 is a configuration diagram of a conventional magneto-optical disk drive.

The conventional magneto-optical disk drive includes a laser light source 20 and signal detectors 5a, 5b, 5c for detecting laser light emitted from the laser light source 20 at a predetermined position.
5d, and a movable optical system 21 composed of a swing arm for holding a solid immersion lens 24 and the like arranged close to the magneto-optical disk 8. The movable optical system 21 includes, on a swing arm, a solid immersion lens 24 for recording and reproducing information on the magneto-optical disk 8, an objective lens 23 for condensing laser light incident on the solid immersion lens 24, and an objective lens 23. It has a configuration that includes a rising mirror 2 that guides laser light and a mirror 6 that is arranged on the center of the rotation axis of the swing arm and guides the laser light from the fixed optical system 7 to the rising mirror 2 (hereinafter, referred to as a rotating mirror). is there.

The mirrors 2 and 6 refer to all optical components including a beam splitter and having a surface for reflecting light.

The magneto-optical disk drive device having such a configuration reproduces information by detecting the Kerr rotation angle of the polarization plane of the laser beam. (Reproduction based on the Kerr rotation angle is limited to the magneto-optical disk. , The car rotation angle is detected during reproduction, and is irrelevant during recording).

Therefore, the laser beam applied to the information recording medium 8 must be linearly polarized.

It is also known that the reflectivity of a linearly polarized laser beam on a mirror differs depending on the angle of the plane of polarization of the laser beam with respect to the reflecting surface of the mirror. As shown in FIG. 13, in an optical system in which linearly polarized laser light is incident on the rotating mirror 6 from the fixed optical system 7, the intensity of the laser light reflected by the rotating mirror 6 varies depending on the direction of the rotating mirror 6. become. Therefore, in the conventional magneto-optical disk drive, the magneto-optical disk 8 and the signal detector 5
The intensity of the laser light applied to the mirror changes depending on the direction of the rotating mirror 6. As a result, there is a disadvantage that the S / N ratio of a signal when desired information is recorded or reproduced on the magneto-optical disk 8 changes depending on the direction of the rotating mirror 6.

[0012]

As described above, a magneto-optical disk drive device equipped with a conventional solid immersion lens, that is, a laser light source is fixed to the magneto-optical disk drive device, and the solid immersion lens is moved by a swing arm. If the configuration is such that it is positioned on the magneto-optical disk, the desired position on the magneto-optical disk depends on the direction of the rotating mirror installed on the center of the rotation axis of the swing arm to guide the laser beam to the solid immersion lens. There has been a problem that the S / N ratio of a signal at the time of recording information or reproducing arbitrary information changes, and a desired operation cannot be performed. In view of the above, the present invention has been made in view of the above-described conventional problems, and the S / N ratio of a signal for recording or reproducing desired information in the direction of a rotating mirror installed on the center of a rotation axis of a swing arm is described. It is an object of the present invention to provide a magneto-optical disk drive capable of performing a stable predetermined operation without depending on the ratio.

[0013]

In order to achieve the above object, a magneto-optical disk drive of the present invention comprises:
A fixed optical system having a laser light source, a solid immersion lens that receives laser light from the fixed optical system and irradiates the information recording medium with laser light, and holds the solid immersion lens at a predetermined position on the information recording medium A movable optical system having a swing arm; anda magneto-optical disk drive that records / reproduces desired information on / from the information recording medium by using an evanescent wave generated by the solid immersion lens. ,
A magneto-optical disk drive device fixedly disposed on the information recording medium, wherein the laser light incident on the movable optical system is substantially circularly polarized. Further, in the magneto-optical disk drive device of the present invention, a solid immersion lens is mounted, a laser light source is fixed to the device, the fixed immersion lens is positioned on the disk by a swing arm, and directs a beam to the solid immersion lens. Therefore, in a magneto-optical disk drive device in which a rotating mirror is arranged substantially on the center of the rotation axis of the swing arm, a laser beam incident on an optical system (movable optical system) that rotates together with the swing arm is converted into circularly polarized light. A λ / 4 wavelength plate is fixed to the device, and the movable optical system is λ / 4 to linearly polarize the laser beam irradiated on the disk.
A wave plate is provided.

Further, by making the laser beam incident on the movable optical system circularly polarized, the intensity of the laser beam reflected by the rotating mirror does not change depending on the direction of the rotating mirror. The S / N ratio of the signal does not depend on the direction of the rotating mirror. Further, by providing a λ / 4 wavelength plate in the movable optical system, the laser light is returned to linearly polarized light, and information can be reproduced from the magneto-optical disk.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a side view of a first embodiment of the magneto-optical disk drive of the present invention, and FIG.
1 is a configuration diagram of an optical system according to a first embodiment of a magneto-optical disk drive device of the present invention. The magneto-optical disk 8 (information recording medium) is rotatably supported by a spindle motor 9 about a disk rotation shaft 10 as a rotation axis. The swing arm 4 is arranged apart from the magneto-optical disk 8. The rising mirror 2 is provided at one end of the swing arm 4, and the rotating mirror 6 is provided at the other end. The evanescent optical system 1 is arranged between the swing arm 4 and the magneto-optical disk 8 so as to be separated from each other, and the evanescent optical system 1 is held by the suspension 3. One end of the suspension 3 is provided with the evanescent optical system 1 as described above, and the other end is connected to a predetermined position of the swing arm 4. The evanescent optical system 1 is supported by a suspension 3 and is a floating head. An arm rotation shaft 13 rotatably supports the swing arm 4 on the rotation mirror 6 side of the swing arm 4. The arm rotation shaft 13 is connected to an arm driving mechanism 14, and can perform a predetermined operation by the arm driving mechanism 14. A beam splitter 11 and a λ / 4 wavelength plate 12 (λ / 4 wavelength polarizing means) are provided between the rising mirror 2 and the rotating mirror 6 (inside the swing arm 4). A detection optical system 5 is arranged near the outside of the swing arm 4 corresponding to the position where the beam splitter 11 is provided. Here, since the detection optical system 5 is provided on the swing arm 4, the influence of the rotating mirror 6 on the detection signal can be minimized. The fixed optical system 7 is fixed to the casing 50.

The magneto-optical disk 8 and the swing arm 4 placed in the casing 50 are provided on a substrate 51. The board 51 is fixed to the casing 50.
Therefore, the fixed optical system 7 is fixed to the magneto-optical disk 8.

The operation of the first embodiment having such a configuration will be described. The circularly polarized laser light emitted from the fixed optical system 7 is applied to the rotating mirror 6. Rotating mirror 6
Is transmitted through the λ / 4 wavelength plate 12 and the beam splitter 11 in this order, and is incident on the rising mirror 2. The linearly polarized laser light guided by the falling mirror 2 and reflected in a predetermined direction is applied to the evanescent optical system 1. The laser light applied to the evanescent optical system 1 is condensed and forms a minute light spot on the magneto-optical disk 8. The light reflected from the evanescent optical system 1 has a tilted polarization plane due to the Kerr effect according to the magnetic signal of the portion where the light spot on the magneto-optical disk 8 is formed. The laser beam reflected by the magneto-optical disk 8 and traveling through the evanescent optical system 1 and the rising mirror 2 is incident on the beam splitter 11. The laser light is reflected by the beam splitter 11 and guided to the detection optical system 5. Next, the configuration and operation of each optical system will be described in detail. The fixed optical system 7 includes a laser light source 20 that emits laser light, a collimator lens 19, a plurality of prisms 18, a λ / 4 wavelength plate 12, and a mirror 16.

The movable optical system 21 includes a rotating mirror 6.
, A λ / 4 wavelength plate 12, a beam splitter 11, a rising mirror 2, and an evanescent optical system 1.

The detection optical system 5 includes a beam splitter 11, a λ / 2 wavelength plate 17, a polarization beam splitter 15, reproduction signal detectors 5a and 5b, and a tracking signal detector 5c. You.

The linearly polarized laser light emitted from the laser light source 20 becomes parallel light by the collimator lens 19 and enters the prism 18. The incident laser light is
The prism 18 is formed to have a desired cross-sectional shape, for example, a circular shape. The laser beam whose cross-sectional shape is deformed is incident on the λ / 4 wavelength plate 12 and becomes circularly polarized light. The circularly polarized laser light enters the mirror 16 and is reflected in a predetermined direction. The laser light reflected by the mirror 16 is incident on the rotating mirror 6 of the movable optical system 21.
The laser light reflected in a predetermined direction by the rotating mirror 6 reaches the evanescent optical system 1 through the λ / 4 wavelength plate 12, the beam splitter 11, and the rising mirror 2 in this order. The laser beam from the evanescent optical system 1 is reflected by the magneto-optical disk 8 and then passes through the evanescent optical system 1 and the rising mirror 2 again to pass through the beam splitter 11.
It is led to. The reflected light from the evanescent optical system 1 is
The light is guided to the detection optical system 5 by the beam splitter 11. The light reflected by the beam splitter 11 enters the beam splitter 11 in the detection optical system 5, and a part of the laser light is
The remaining laser light guided to the tracking signal detector 5c advances to the λ / 2 wavelength plate 17. The laser beam that has advanced to the λ / 2 wavelength plate 17 enters the polarization beam splitter 15 after the angle of the polarization plane is adjusted inside. In the polarization beam splitter 15, a part of the laser light is supplied to the reproduction signal detector 5b.
And the remaining laser light proceeds to the reproduction signal detector 5a.

The signal detectors 5a and 5b are photodiodes (light intensity measuring devices), each of which measures the intensity of light divided into two polarization components by the polarization beam splitter 15, and returns by observing the difference. It detects how much the plane of polarization of the light is inclined based on the reproduction signal on the magneto-optical disk 8. In the first embodiment as described above, the intensity of the laser light reflected by the rotating mirror 6 changes depending on the direction of the rotating mirror 6 by making the laser light incident on the movable optical system 21 circularly polarized. Has been prevented.

Circularly polarized light has symmetric polarization characteristics around the optical axis. Therefore, unlike linearly polarized light whose polarization characteristics around the optical axis are not symmetric, the mirror 6 rotates about the optical axis.
When the light is reflected to the mirror 6, its reflectance does not depend on the orientation of the mirror 6. As a result, when recording or reproducing desired information on or from the magneto-optical disk 8, a stable operation can be performed without the signal S / N ratio depending on the direction of the rotating mirror. Further, the movable optical system 21 is provided with the λ / 4 wavelength plate 12.
Is provided, the laser light is returned to linearly polarized light, and predetermined information can be reproduced from the magneto-optical disk 8. Next, the configuration of the second embodiment of the present invention will be described with reference to FIGS.
This will be described with reference to FIG. In each of the following examples,
The same components as those in the first embodiment are denoted by the same reference numerals, and overlapping description will be omitted. The feature of the second embodiment is that the detection optical system 5
Is provided in the fixed optical system 7 without being provided in the swing arm 4. FIG. 3 is a side view of a second embodiment of the magneto-optical disk drive of the present invention, and FIG. 4 is a configuration diagram showing an optical system of the second embodiment of the magneto-optical disk drive of the present invention.

The fixed optical system 7 includes a laser light source 20 for emitting laser light, a collimator lens 19, a plurality of prisms 18, a λ / 4 wavelength plate 12, and a beam splitter 11
And a mirror 16.

The detection optical system 5 has the same configuration as that of the first embodiment, and includes a beam splitter 11 and a λ / 2 wavelength plate 1.
7, a polarization beam splitter 15, and a plurality of signal detectors 5.

The movable optical system 21 includes a rotating mirror 6
, A λ / 4 wavelength plate 12, a rising mirror 2, and an evanescent optical system 1.

The detection optical system 5 is provided on the swing arm 4 and is provided on the fixed optical system 7.

The operation of the second embodiment having such a configuration will be described.

The laser light generated by the laser light source 20 is
The collimator lens 19, the plurality of prisms 18, the λ / 4 wavelength plate 12, the beam splitter 11, and the mirror 16 pass through the fixed optical system 7 in this order, and are guided to the rotating mirror 6 of the movable optical system 21. 12, the rising mirror 2, and the evanescent optical system 1 pass through the movable optical system 21 in this order, and reach the magneto-optical disk 8.

The laser beam reflected by the magneto-optical disk 8 is
The light passes through the movable optical system 21 in the order of the evanescent optical system 1, the rising mirror 2, the λ / 4 wavelength plate 12, and the rotating mirror 6, and is incident on the mirror 16 of the fixed optical system 7. The laser light whose traveling direction has been changed by the mirror 16 is transmitted to the beam splitter 11.
Then, it is guided to the detection optical system 5. The laser light guided to the detection optical system 5 is guided to the beam splitter 11 and travels to the λ / 2 wavelength plate 17 and the tracking signal detector 5.
It is split into a laser beam going to c. The laser light that has passed through the λ / 2 wavelength plate 17 is guided to the polarization beam splitter 15 and is split into a reproduced signal detector 5a and a reproduced signal detector 5b and incident on each of them.

Here, actually, the reflected laser light whose polarization plane is inclined by the magnetic signal on the magneto-optical disk 8 is:
Since the λ / 4 wavelength plate 12 on the swing arm 4 enters the rotating mirror 6 as elliptically polarized light instead of a perfect circle, the influence of the direction of the rotating mirror 6 is slightly reflected in the intensity.

In the second embodiment described above, the intensity of the laser light reflected by the rotating mirror 6 is changed depending on the direction of the rotating mirror 6 by making the laser light incident on the movable optical system 21 circularly polarized. Prevent change. Therefore, when desired information is recorded on the magneto-optical disk 8, a stable operation can be performed without the signal S / N ratio depending on the direction of the rotating mirror. Further, by providing the movable optical system 21 with the λ / 4 wavelength plate 12, the laser light can be returned to linearly polarized light, and predetermined information can be reproduced from the magneto-optical disk 8.

Further, by providing the detection optical system 5 in the fixed optical system 7, the rotational moment of the swing arm 4 is reduced, whereby the resonance frequency of the swing arm 4 is increased, and the evanescent optical system 1 is operated faster and more quickly. Positioning on the magneto-optical disk 8 can be performed stably.

Next, the structure of a third embodiment of the present invention will be described with reference to FIGS.

The feature of the third embodiment is that the movable optical system 21 has a λ
If the position where the 波長 wavelength plate 12 is arranged is within the movable optical system 21, it can be set at an arbitrary position.

FIG. 5 is a side view of a third embodiment of the magneto-optical disk drive of the present invention, and FIG. 6 is a structural diagram showing an optical system of the third embodiment of the magneto-optical disk drive of the present invention. It is.

The configuration of the fixed optical system 7 and the detection optical system 5 is as follows.
This is the same as the first embodiment.

The components of the movable optical system 21 are the same as those in the first embodiment, but their arrangement is slightly different, and the order of passage of the laser light guided from the fixed optical system 7 is λ / 4 wavelength plate. 12, a beam splitter 11, a rotating mirror 6, a rising mirror 2, and an evanescent optical system 1 are arranged.

The operation of the third embodiment having such a configuration will be described.

The laser light introduced from the fixed optical system 7 to the λ / 4 wavelength plate 12 is already circularly polarized. The linearly polarized laser light is applied to the magneto-optical disk 8, reflected, and guided by the beam splitter 11 of the movable optical system 21 to the beam splitter 11 of the detection optical system 5.
In the detection optical system 5, the laser beam from the beam splitter 11 is incident on the reproduction signal detector 5a, the reproduction signal detector 5b, or the tracking signal detector 5c.

In the third embodiment as described above, the intensity of the laser light reflected by the rotating mirror 6 depends on the direction of the rotating mirror 6 by making the laser light incident on the movable optical system 21 circularly polarized. Prevent change.

The light incident on the rotating mirror 6 is not circularly polarized light but linearly polarized light. The linear polarization state is due to the λ / 4 wavelength plate 12 in the movable optical system 21 that rotates around the same center of rotation together with the rotating mirror 6. The relative relationship between the polarization plane and the reflecting surface of the rotating mirror 6 is Not affected by the orientation of the Therefore, when recording or reproducing desired information on or from the magneto-optical disk 8, a stable operation can be performed without the signal S / N ratio depending on the direction of the rotating mirror. Further, by providing the movable optical system 21 with the λ / 4 wavelength plate 12, the laser light can be returned to linearly polarized light, and predetermined information can be reproduced from the magneto-optical disk 8.

The λ / 4 wavelength plate 12 of the movable optical system 21
Can be set at any position, so that the degree of freedom in manufacturing is improved.

Further, since the installation position of the beam splitter 11 of the movable optical system 21 for guiding the laser light to the detection optical system 5 can be set as appropriate, the degree of freedom in manufacturing increases.

Next, the configuration of a fourth embodiment of the present invention will be described with reference to FIGS.

The feature of the fourth embodiment is that the detection optical system 5 further includes a beam splitter 11 and a focus signal detector 5d.
And the movable optical system 21 is further provided with a focusable objective lens 22.

FIG. 7 is a side view of a fourth embodiment of the magneto-optical disk drive of the present invention, and FIG. 8 is a structural view showing an optical system of the magneto-optical disk drive of the present invention.

The components and arrangement of the fixed optical system 7 are the same as in the first embodiment.

The movable optical system 21 includes a rotating mirror 6 and a λ /
Four-wave plate 12, beam splitter 11, rising mirror 2, evanescent optical system 1, swing arm 4
And a focusable objective lens 22 having a focus function of focusing laser light.

For example, the focusable objective lens 22 is
It is provided to improve the focusing accuracy of the pit shape formed on the surface of the magneto-optical disk 8.

Further, in the fourth embodiment, the focusable objective lens 22 is provided on the swing arm 4, but it can be provided on the evanescent optical system 1.

The detection optical system 5 includes two beam splitters 11, a λ / 2 wavelength plate 17, and a polarization beam splitter 1.
5, a reproduction signal detector 5a, 5b, a tracking signal detector 5c, and a focus signal detector 5d. In order to control the focusable objective lens 22 provided in the movable optical system 21, the focus signal detector 5
d is provided.

The operation of the fourth embodiment having such a configuration will be described. In order to control the focus of the laser beam emitted from the evanescent optical system 1 to the magneto-optical disk 8 with higher precision, the reflected signal from the magneto-optical disk 8 is detected by the focus signal detector 5d, and the focusable objective lens 22 is detected. The control is performed such that the diameter of the light spot on the surface of the magneto-optical disk 8 is as small as possible.

In the fourth embodiment as described above, the intensity of the laser light reflected by the rotating mirror 6 depends on the direction of the rotating mirror 6 by making the laser light incident on the movable optical system 21 circularly polarized. Prevent change.

Therefore, when recording or reproducing desired information on or from the magneto-optical disk 8, a stable operation can be performed without the signal S / N ratio depending on the direction of the rotating mirror.

The movable optical system 21 is provided with the λ / 4 wavelength plate 12.
Is provided, the laser light is returned to linearly polarized light, and predetermined information can be reproduced from the magneto-optical disk 8.

Further, by controlling the focus of the laser beam applied to the magneto-optical disk 8, a more stable operation can be performed, and desired information can be recorded or reproduced with high accuracy.

Next, the configuration of the evanescent optical system provided in the magneto-optical disk drive of the present invention will be described.
This will be described with reference to FIGS.

FIG. 9 is a side view of the evanescent optical system of the first example of the magneto-optical disk drive of the present invention.
FIG. 10 shows a second embodiment of the magneto-optical disk drive of the present invention.
FIG. 11 is a side view of an example evanescent optical system, FIG.
FIG. 12 is a side view of an evanescent optical system of a third example of the magneto-optical disk drive of the present invention, and FIG. 12 is a side view of an evanescent optical system of a fourth example of the magneto-optical disk drive of the present invention. (First Example) An evanescent optical system 1 includes a flying slider 26 having a through hole serving as a casing, a solid immersion lens 24 provided to cover one end of the through hole of the flying slider 26, and a vicinity of the solid immersion lens 24. And a signal recording coil 25 provided on the flying slider 26, and an objective lens 23 disposed so as to close the other end of the through hole.

The operation of the evanescent optical system 1 having such a configuration will be described.

The parallel light (laser light) incident from a rising mirror (not shown) is collected by the objective lens 23. The condensed laser light is applied to the solid immersion lens 2
4, the light is refracted again at its surface and forms a light spot on the bottom surface of the solid immersion lens 24 with a higher numerical aperture.

The laser beam is refracted again by the solid immersion lens 24, so that the diameter of the objective lens 23 can be reduced.
Can be reduced in size. (Second example) A flying slider 26, an objective lens 23,
The signal recording coil 25 is the same as in the first example. The place where the solid immersion lens 24 is arranged is the same as in the first example.

However, the solid immersion lens 24 is
It is hemispherical and has the property that laser light from the objective lens 23 is vertically incident on its surface, and forms a light spot inside the lens 24 (bottom surface).

By using a hemispherical lens as the solid immersion lens 24, it is possible to easily set each component such as optical axis alignment. (Third example) Floating slider 26 and signal recording coil 2
5 is the same as the first example. The place where the solid immersion lens 24 is arranged is the same as in the first example.

The solid immersion lens 24 is an aspheric lens. Laser light (parallel light) from a rising mirror (not shown) is directly incident on the solid immersion lens 24, and the inside (bottom surface) of the lens 24 is formed.
To form a light spot.

By directly inputting parallel light to the solid immersion lens 24, an objective lens for condensing the parallel light is not required, and the evanescent optical system can be reduced in size and thickness. In addition, there is no need to perform optical alignment such as alignment of the optical axis between the objective lens and the solid immersion lens, and simple settings can be made. At the same time, it contributes to cost reduction. (Fourth example) Floating slider 26 and signal recording coil 2
5, solid immersion lens 24, objective lens 23
Is the same as in the first example.

Between the objective lens 23 and the solid immersion lens 24, a meniscus lens 27 having an arc-shaped cross section is disposed apart from each other.

The laser light (parallel light) incident from a rising mirror (not shown) is condensed by an objective lens 23, further condensed by a meniscus lens 27, and incident on a solid immersion lens 24, where the solid immersion lens 24
A light spot is formed inside (bottom).

By using the meniscus lens 27, the optical load on the objective lens 23 for condensing the parallel light can be reduced. Such first to fourth examples
In the example, by providing the objective lens 23 with the evanescent optical system, the objective lens 23 does not need to be installed on the swing arm side, and as a result, the flying type slider 26 can be further reduced in weight. By reducing the weight of the swing arm, the operation of recording or reproducing predetermined information can be sped up. The present invention is not limited to the above embodiment, and it goes without saying that various modifications can be made without departing from the spirit of the present invention. For example,
The solid immersion lens may have any shape as long as a light spot can be formed on the bottom surface.

[0069]

As described above, according to the present invention, it is possible to stabilize the S / N ratio of a signal when recording or reproducing desired information on an information recording medium.

[Brief description of the drawings]

FIG. 1 shows a first embodiment of a magneto-optical disk drive according to the present invention.
Example side view

FIG. 2 shows a first example of the magneto-optical disk drive of the present invention.
Configuration diagram showing an optical system of an embodiment

FIG. 3 shows a second embodiment of the magneto-optical disk drive of the present invention.
Example side view

FIG. 4 shows a second example of the magneto-optical disk drive of the present invention.
Configuration diagram showing an optical system of an embodiment

FIG. 5 shows a third embodiment of the magneto-optical disk drive of the present invention.
Example side view

FIG. 6 shows a third example of the magneto-optical disk drive of the present invention.
Configuration diagram showing an optical system of an embodiment

FIG. 7 shows a fourth example of the magneto-optical disk drive of the present invention.
Example side view

FIG. 8 shows a fourth example of the magneto-optical disk drive of the present invention.
Configuration diagram showing an optical system of an embodiment

FIG. 9 shows a first example of the magneto-optical disk drive of the present invention.
Side view of example evanescent optics

FIG. 10 is a side view of an evanescent optical system according to a second example of the magneto-optical disk drive of the present invention.

FIG. 11 is a side view of an evanescent optical system according to a third example of the magneto-optical disk drive of the present invention.

FIG. 12 is a side view of an evanescent optical system according to a fourth example of the magneto-optical disk drive of the present invention.

FIG. 13 is a configuration diagram of a conventional magneto-optical disk drive device.

[Explanation of symbols]

 Reference Signs List 4 swing arm 6 rotating mirror 7 fixed optical system 8 magneto-optical disk (information recording medium) 12 λ / 4 wavelength plate 13 arm rotation axis 20 laser light source 21 movable optical system 24 solid immersion lens 50 casing (supporting portion) 51 substrate (supporting) Part)

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Noriyuki Ishibashi 1st, Komukai Toshiba-cho, Yuki-ku, Kawasaki-shi, Kanagawa Prefecture Toshiba R & D Center (72) Inventor Makoto Asakura Komukai, Yuki-ku, Kawasaki-shi, Kanagawa 1 Toshiba-cho, Toshiba R & D Center (72) Inventor Takao Omi 2-9, Suehiro-cho, Ome-shi, Tokyo In-house Toshiba Ome Plant (72) Inventor Minoru Yonezawa Koyuki-ku, Kawasaki-shi, Kanagawa No. 1, Muko Toshiba, Toshiba R & D Center (72) Inventor Yasuo Mogi, No. 1, Komukai Toshiba, Kochi, Kawasaki, Kanagawa Pref. Toshiba R & D Center F-term (reference) CD17 DD03 5D119 AA12 AA22 BA01 BB05 DA01 DA05 EB03 FA02 JA32

Claims (2)

[Claims] A fixed optical system having a laser light source; a solid immersion lens for receiving laser light from the fixed optical system and irradiating the information recording medium with laser light; A movable optical system having a swing arm for holding at a predetermined position,
By the evanescent wave generated by the solid immersion lens, in a magneto-optical disk drive for recording and reproducing desired information on the information recording medium, the fixed optical system is fixedly arranged with respect to the information recording medium,
And a laser beam incident on the movable optical system is substantially circularly polarized light. 2. The method according to claim 1, wherein the magneto-optical disk drive has a λ /
2. The magneto-optical disk drive device according to claim 1, wherein the four-wavelength plate is fixed to the device.