JPH0689478A - Method for setting relative position of perpendicular magnetic field and magneto-optical disk for setting relative position used - Google Patents

Abstract

PURPOSE:To exactly dispose a light spot at the center of the magnetic field distribution created by the magnetic head chip of a flying head. CONSTITUTION:A region for inspection is irradiated with a light beam for reproduction and is detected by previously recorded information and an optical head and the flying head are roughly adjusted and disposed in S1. An X-Y table is set at an initial position in S2. A driving signal is impressed to the magnetic head and the magnetic fields larger than the coercive force of a garnet film are repetitively generated in S3. The flying head is moved in a direction X by operating the X-Y table, the peak value of reproduced signals is measured and the center of X is calculated in S4. The flying head is similarly moved in a direction Y by operating the X-Y table in the state of fixing the center of X calculated by S4, the peak value of the reproduced signals is measured, the center of Y is calculated and the position of the flying head in the directions X, Y is determined in S5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vertical magnetic field which opposes a light beam irradiating means and which sets a relative position of a vertical magnetic field applied to a light spot and its periphery by means of an integrated vertical magnetic field generating means. And a relative position setting magneto-optical disk used in the method.

[0002]

2. Description of the Related Art In recent years, with the development of information technology, an optical information recording / reproducing device has attracted attention as a large capacity information storing / reproducing device. Among the optical information recording / reproducing apparatuses, the magneto-optical method has received particular attention because it is rewritable. In this magneto-optical recording, a recording medium in which a magnetic film having an easy axis of magnetization in the direction perpendicular to the film surface is formed on a transparent substrate is used, and the magnetic film has regions (marks) of different magnetization directions.
To store information.

As described above, as a method of forming marks having different magnetization directions, a recording light beam is irradiated onto a magnetic film as a light spot by an objective lens or the like to raise the temperature of the light spot and the magnetic film in the vicinity thereof. Therefore, there is a so-called magnetic field modulation method in which the coercive force is reduced and the magnetic field is externally modulated by a magnetic head or the like.

In such a magnetic field modulation method, FIG.
As shown in, for example, a light spot irradiated by an objective lens 52 and a magnetic head 53 are arranged to face each other via a magneto-optical disk 51 as a recording medium that is rotationally driven by a spindle motor 50, Objective lens 5
The optical system including 2 and the magnetic head 53 are connected to the magneto-optical disk 5
By making it movable in the radial direction of 1, information can be recorded at a desired position on the magneto-optical disk 51. The tracking control or the focus control is performed by finely adjusting the objective lens 52 in the radial direction or in the direction perpendicular to the magneto-optical disk 51.

A magnetic field area applied to the magneto-optical disk 51 by magnetically modulating the magnetic head 53 with a magnetic field modulation signal is set by gap control for controlling a distance t between the magnetic head 53 and the magneto-optical disk 51. For example, the size is about 1000 μm × 1000 μm. Tracking control in the case of having a magnetic field area of this extent can be performed by moving the objective lens 52 in the radial direction by, for example, 200 μm, as shown in FIG.

On the other hand, recently, in such an optical information recording / reproducing apparatus, high-density recording of information is expected, and for that purpose, it is desired that the apparatus be downsized together with high frequency of a recording signal, and it is used for an HDD. An optical information recording / reproducing apparatus having a small magnetic head called a flying head has been developed.

As shown in FIG. 9, for example, the thickness is 2 to 3 m.
The flying head 70 of m is provided with a small magnetic head chip 71, and the flying head 70 is fixed to an XY table 72 which is capable of fine movement in the front, rear, left and right directions via a gimbal spring 73. The XY table 72 is an optical head 7 provided to face the flying head 70.
4 is fixed to an actuator 75 that is movable in the radial direction of the magnetic disk 51, and an optical head 74 and a flying head 72 are arranged to face each other with the magneto-optical disk 51 interposed therebetween.

The actuator 75 is provided with a linear motor coil 76, which can be moved in the radial direction by a linear motor (not shown). Also,
The optical head 74 includes an objective lens 77 that forms a light spot on the magneto-optical disk 51, and a coil 78 that drives the objective lens 77 for focus servo and tracking servo.

Such a flying head 70 is shown in FIG.
As shown in FIG. 10 which is an enlarged view of the range indicated by the symbol A, since the magnetic head chip 71 is small, the magnetic field area created by this magnetic head chip 71 is 100 μm.
The size is about 100 μm. Therefore, the magnetic head chip 71 of the flying head 70 and the optical head 7
It is important that the position facing the light spot by 4 is set accurately.

As shown in FIG. 11, the conventional magnetic head chip 71 and the optical head 74 are used to set the facing position of the light spot, for example, as shown in FIG.
0, a solid-state image sensor is provided by the detection objective lens 91,
For example, the marker 90 is imaged by the CCD 92, and the CCD
The signal from 92 is processed by the signal processing circuit 93, observed by the monitor 94, the position of the marker 90 with respect to the light spot by the optical head 74 is measured, and the XY table 72 is finely adjusted.

[0011]

However, in an optical information recording / reproducing apparatus using such a flying head 70, it is important to position the light spot at the center of the magnetic head chip 71 of the flying head 70. However, the adjustment of the XY table 72 or the like by the microscopic measurement using the CCD or the like described above cannot accurately position the light spot at the center of the magnetic head chip 71. In addition, it is impossible to check how accurately the adjusted position is adjusted. Furthermore, even if the light spot can be positioned substantially at the center of the magnetic head chip 71 by a marker or the like, the position of the marker and the distribution of the magnetic field do not necessarily correspond exactly, so the magnetic head chip The light spot cannot be located at the center of the magnetic field distribution created by 71.

The present invention has been made in view of the above circumstances, and a method for setting a relative position of a vertical magnetic field capable of accurately forming a light spot in the center of a magnetic field distribution created by a magnetic head chip of a flying head, and It is an object to provide a magneto-optical disk for relative position setting used in the method.

[0013]

A method for setting a relative position of a vertical magnetic field according to a first aspect of the present invention relates to a light spot formed on a recording surface of a magneto-optical disk 3 by an optical head 4 as a light beam irradiating means. A relative magnetic field relative position setting method for setting a relative position of a vertical magnetic field applied to a light spot and its periphery by a flying head 5 as a vertical magnetic field generating means integrally opposed to the optical head 4 , Processing S2 as an initial relative position setting process for setting an initial relative position between the optical head 4 and the flying head 5, and processing S3 as a vertical magnetic field application process for applying a vertical magnetic field to the light spot and its periphery by the flying head 5. And the flying head 5 or the optical head 4 in the first direction in a plane parallel to the recording surface of the magneto-optical disk 3.
And a maximum value of the vertical magnetic field with respect to the light spot position is detected, and a relative position of the vertical magnetic field in the first direction is set.
In the plane parallel to the recording surface of the magneto-optical disk 3, the flying head 5 or the optical head 4 is moved in a second direction independent of the first direction, and the maximum value of the vertical magnetic field with respect to the light spot position is detected. And a process S5 as a second relative position setting process for setting the relative position of the vertical magnetic field in the second direction.

The relative position setting magneto-optical disk according to a second aspect of the invention is opposed to the optical head 4 with respect to a light spot formed on the recording surface of the magneto-optical disk 3 by the optical head 4 as a light beam irradiation means. Then, a relative position setting magneto-optical device used in a vertical magnetic field relative position setting method for setting a relative position of a vertical magnetic field applied to a light spot and its periphery by a flying head 5 as an integrated vertical magnetic field generating means. In the magneto-optical disk 3 as a disk, an Al film 32 as a reflecting member is provided on one surface of a non-magnetic garnet substrate 30 as a translucent non-magnetic substrate, and the non-magnetic garnet substrate 30 and the Al film 32 are provided. A garnet film 31 as a magnetic film having a small coercive force is formed between them.

[0015]

According to the relative magnetic field relative position setting method of claim 1, the flying head 5 or the optical head 4 is moved in a first direction in a plane parallel to the recording surface of the magneto-optical disk 3 in step S4. Then, the maximum value of the vertical magnetic field with respect to the light spot position is detected, the relative position of the vertical magnetic field in the first direction is set, and in step S5, the first direction in the plane parallel to the recording surface of the magneto-optical disk 3 is detected. By moving the flying head 5 or the optical head 4 in a second direction independent of
The maximum value of the vertical magnetic field with respect to the light spot position is detected, and the relative position of the vertical magnetic field in the second direction is set. Therefore, the light spot can be accurately arranged at the center of the vertical magnetic field distribution created by the flying head 5.

In the magneto-optical disk for relative position setting according to the second aspect of the invention, the Al film 32 is provided on one surface of the transparent non-magnetic garnet substrate 30, and the non-magnetic garnet substrate 3 is provided.
Garnet film 31 having a small coercive force between 0 and the Al film 32.
Therefore, by performing the relative position setting method of the vertical magnetic field using this relative position setting magneto-optical disk, the light spot can be accurately arranged at the center of the vertical magnetic field distribution created by the flying head 5. You can

[0017]

Embodiments of the present invention will be described below with reference to the drawings.

1 to 6 relate to an embodiment of the present invention, and FIG. 1 is a configuration diagram showing a configuration of a main part of an optical information recording / reproducing apparatus used in a method of setting a relative position of a vertical magnetic field. FIG. 4 is an explanatory view for explaining a polarization state of reflected light from the magneto-optical disk, FIG. 3 is an explanatory view for explaining a reproduction signal by reflected light from the magneto-optical disk, and FIG. 4 is a structure showing a structure of the magneto-optical disk. 5 and 5 are flowcharts illustrating the flow of the method for setting the relative position of the vertical magnetic field, and FIG. 6 is an explanatory diagram illustrating the vertical magnetic field distribution measured by the flowchart of FIG.

As shown in FIG. 1, the optical information recording / reproducing apparatus 1 used in the method of the present embodiment uses light emitted from an optical head 4 via a magneto-optical disk 3 which is rotationally driven by a spindle motor 2. By arranging the spot and the flying head 5 so as to face each other and arranging the optical head 4 and the flying head 5 to be movable in the radial direction of the magneto-optical disk 3, a desired position of the magneto-optical disk 3 can be obtained. Information can be recorded at the location.

The flying head 5 is provided with a small magnetic head chip 5a.
A is driven by the electromagnet circuit 6 based on a drive signal from a signal generating means (not shown), and applies a magnetic field corresponding to the drive signal to the recording surface of the magneto-optical disk 3. Further, the flying head 5 is fixed to an XY table 7 which can be moved finely back and forth and left and right via a gimbal spring 7a. The XY table 7 is such that the optical head 4 provided so as to face the flying head 5 is fixed to an actuator 8 which is movable in the radial direction of the magnetic disk 3, and the flying head 5 and the optical head 4 are provided via the magneto-optical disk 3. The head 5 is arranged so as to face it.

The actuator 8 is provided with a linear motor coil 9 so that the flying head 5 and the optical head 4 can be integrally moved in the radial direction by a linear motor (not shown).

The optical head 4 collimates light from the laser diode (LD) 10 for generating a linearly polarized recording light beam and reproducing light beam, for example, S-polarized light, and light from the laser diode 10. Collimator lens 11
A beam splitter 12 that transmits the light from the collimator lens 11 and an objective lens 2 that focuses the light transmitted through the beam splitter 12 on the magneto-optical disk 3.
0, and a coil 21 as an actuator for driving the objective lens 20 in the tracking direction and the focus direction.

As shown in FIG. 2A, the reflected light from the magneto-optical disk 3 rotates by + θk or −θk due to the Kerr effect due to the polarity of the magnetic recording information, and then passes through the objective lens 20. The light enters the beam splitter (BS) 12, is reflected there, and is transmitted to the half-wave plate 13. In the half-wave plate 13, the polarization direction of the incident light is rotated by 45 °, as shown in FIG. 1/2
The light from the wave plate 13 is transmitted through a polarization beam splitter (PB
It is separated into S-polarized light and P-polarized light by (S) 14 and focused on photodetectors 17 and 18 via objective lenses 15 and 16, respectively. The signals corresponding to the S-polarized light and the P-polarized light from the photodetectors 17 and 18 are as shown in FIGS. 3 (a) and 3 (b).
A reproduction signal as shown in (c) is obtained.

The magneto-optical disk 3 is a magneto-optical disk for inspection, and as shown in FIG. 4, one surface of a translucent non-magnetic garnet (GGG) substrate 30 having a thickness t and a refractive index n, For example, the film thickness is 2 to 4 μm by liquid phase growth, the coercive force is about several [Oe], and the Faraday rotation angle θF = 10 °.
/ Μm garnet film 31 is formed, and Al (aluminum) as a reflective film is formed on one surface of the garnet film 31.
A membrane 32 is provided. An inspection area is provided in advance on the track of the recording surface of the magneto-optical disk 3, and the address of the inspection area can be detected by irradiating a reproduction light beam to obtain a reproduction signal. There is.

The method of this embodiment using the optical information recording / reproducing apparatus 1 thus constructed will be described below.

As shown in FIG. 5, in step (hereinafter referred to as S) 1, the LD 10 generates a reproducing light beam and irradiates the magneto-optical disk 3 through the objective lens 20. The reflected light from the magneto-optical disk 3 is received by, for example, the photodetector 7, and the inspection area is detected from the output from the information recorded in advance. In response to this detection result, the actuator 8 is driven by the linear motor coil 9, and the optical head 4 and the flying head 5 are arranged roughly in the inspection area. Next, in S2, the XY table 7 is set to the initial position.

Further, by applying a drive signal in S3, the electromagnet drive circuit 6 causes the magnetic head chip 5a to have a strength larger than the coercive force of the garnet film, for example, ± 150 [O].
The vertical magnetic field [e] is repeatedly generated. In the range where this magnetic field is applied, the perpendicular magnetization direction of the garnet film 31 is the same as the direction of the magnetic field. Therefore, in S4, the XY table 7 is operated, the flying head 5 is moved in the X direction, the peak value of the reproduction signal is measured, and the center of X is calculated. Similarly, in S5, with the X center calculated in S4 fixed, the XY table 7 is operated, the flying head 5 is moved in the Y direction, the peak value of the reproduction signal is measured, and the Y center is calculated. Then, the position of the flying head 5 in the XY directions is determined.

Explaining the detailed processing in S4,
In S6, the level of the reproduction signal from the subtractor 19 is measured, and S
In step 7, a predetermined amount is moved in the X direction, and in step S8, it is determined whether or not the total amount of movement has reached a predetermined Max value (maximum value). N
In the case of O, the process returns to S6 and the processes of S6 to S8 are repeated.
In the case of YES, the process proceeds to S9, the center value of X is calculated in S9, the X direction of the XY table 7 is fixed, and the process proceeds to S5.

Next, the detailed processing in S5 will be described. This processing is the same as in S4. That is, S1
At 0, the level of the reproduction signal from the subtractor 19 is measured, and S1
At 1, a predetermined amount is moved in the Y direction, and at S12, it is determined whether or not the total amount of movement has reached a predetermined Max value. If NO, the process returns to S6 and the processes of S10 to S12 are repeated. YE
In the case of S, the process proceeds to S13, the Y center value is calculated in S13, the Y direction of the XY table 7 is fixed, and the process ends.

That is, the processing of S4 and S5 makes it possible to measure the distribution of the reproduced signal corresponding to the range in which the magnetic field generated by the magnetic head chip 5a is acting, as shown in FIG. In S10, the X and Y center values can be calculated.

As described above, according to the method of aligning the optical head and the magnetic head of this embodiment, a magnetic field larger than the coercive force of the garnet film having the magneto-optical effect is applied by the magnetic head, and the signal from this magnetic head is applied. Direct reproduction measurement by the light spot, and the light spot position by the optical head,
The centers of the magnetic fields generated by the magnetic heads can be matched exactly. Further, even when the seek is performed, the relative displacement between the light spot and the magnetic head chip at the seek time can be adjusted by continuously performing the measurement by the magnetic field modulation.

Although the magneto-optical recording film of the magneto-optical disk is a garnet film having a coercive force of several [Oe] in the above description, it may be a CoPt film having a coercive force of about 100 [Oe]. A perpendicular magnetization film having a magneto-optical effect having a relationship of Mag (applied magnetic field) = Hex (external magnetization)> Hc (coercive force) with respect to the magnetic force Hc may be used, and measurement is performed using the Kerr effect and the Faraday effect.
adjust.

Further, in the above description, the flying head 5 is moved using the XY table 7 to set the relative position, but the present invention is not limited to this, and the optical head 4 can be moved. The relative position may be set.

[0034]

As described above, according to the first aspect of the present invention.
According to the method for setting the relative position of the vertical magnetic field described in (1), the maximum value of the vertical magnetic field with respect to the light spot position is detected and the relative position of the vertical magnetic field is set. The effect is that spots can be arranged.

According to the relative position setting magneto-optical disk of the present invention, since the magnetic film having a small coercive force is formed, the relative position setting magneto-optical disk is used. There is an effect that the light spot can be accurately arranged at the center of the vertical magnetic field distribution.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a configuration of a main part of an optical information recording / reproducing apparatus used in an embodiment of a relative magnetic field relative position setting method of the present invention.

FIG. 2 is an explanatory diagram illustrating a polarization state of reflected light from the magneto-optical disk used in FIG.

FIG. 3 is an explanatory diagram for explaining a reproduction signal by reflected light from a magneto-optical disk by the optical information recording / reproducing apparatus of FIG.

FIG. 4 is a configuration diagram showing a configuration of a magneto-optical disk used in FIG.

5 is a flowchart illustrating a flow of a method of setting a relative position of a vertical magnetic field according to the embodiment of FIG.

FIG. 6 is an explanatory diagram illustrating a vertical magnetic field distribution measured by the flowchart of FIG.

FIG. 7 is a configuration diagram showing a configuration of a main part of a first conventional optical information recording / reproducing apparatus.

8 is an explanatory diagram illustrating tracking control by moving the objective lens in FIG. 7. FIG.

FIG. 9 is a configuration diagram showing a configuration of a main part of a second conventional optical information recording / reproducing apparatus.

FIG. 10 is an enlarged view of the flying head used in FIG.

FIG. 11 is an explanatory diagram illustrating a conventional method of setting a relative position of a vertical magnetic field in the second optical information recording / reproducing apparatus of FIG.

[Explanation of symbols]

 3 Magneto-optical disk 4 Optical head 5 Flying head 5a Magnetic head chip 7 XY table 12 Beam splitter 13 1/2 wavelength plate 14 Polarization beam splitter 17 and 18 Photodetector

Claims (2)

[Claims] 1. A light spot formed by the light beam irradiating means on the recording surface of the magneto-optical disk, and the light spot and the light spot formed by a vertical magnetic field generating means which is integrally formed so as to face the light beam irradiating means. A relative position setting method of a vertical magnetic field for setting a relative position of a vertical magnetic field applied to the periphery, wherein an initial relative position setting process of setting an initial relative position between the light beam irradiation means and the vertical magnetic field generation means, A vertical magnetic field applying process for applying the vertical magnetic field to the light spot and its periphery by the vertical magnetic field generating means, and the vertical magnetic field generating means in the first direction in a plane parallel to the recording surface of the magneto-optical disk, or The light beam irradiation means is moved, the maximum value of the vertical magnetic field with respect to the light spot position is detected, and the relative position of the vertical magnetic field in the first direction is set. A first relative position setting process, and the first relative position setting process in a plane parallel to a recording surface of the magneto-optical disc.
By moving the vertical magnetic field generating means or the light beam irradiating means in a second direction independent of the direction, and detecting the maximum value of the vertical magnetic field with respect to the light spot position, the relative position of the vertical magnetic field in the second direction. And a second relative position setting process for setting the relative magnetic field relative position setting method. 2. A light spot formed on the recording surface of the magneto-optical disk by the light beam irradiating means, and the light spot and the light spot by the vertical magnetic field generating means integrally formed so as to face the light beam irradiating means. A magneto-optical disk for relative position setting used in a relative position setting method of a vertical magnetic field for setting a relative position of a vertical magnetic field applied to the periphery, wherein a reflecting member is provided on one surface of a translucent non-magnetic substrate. A magneto-optical disk for relative position setting, wherein a magnetic film having a small coercive force is formed between the non-magnetic substrate and the reflecting member.