JPH10289501A - Magnetic head and magneto-optical recording / reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To miniaturize an optical pickup and to control a relative angle between a magneto-optical recording medium and an optical beam axis by providing, on a magnetic head, an inclination detecting means for detecting the inclination of the magnetic head when the magnetic head for generating a magnetic field for magneto-optical recording comes into contact with the magneto-optical recording medium. SOLUTION: A magneto-optical disk 7 is loaded on a turntable 12 and rotated. The magneto-optical disk 7 is irradiated with a luminous flux (b) from an optical pickup, a magnetic head 1 is contacted with the magneto-optical disk 7 or floats in air to generate a magnetic field and then records/reproduces information. A driver circuit 5 drives a magnetic head elevation device 4 and moves up and down the magnetic head 1 attached to a leaf spring 18. A light emitted from an inclination detecting means 2 provided in the magnetic head 1 is reflected on a reference surface 10 and retained again to the detecting means 2 to be detected. A detecting signal drives an angle adjusting motor 15 via a differential amplifier 3 and a driver circuit 16 so as to always maintain a right angle between the magnetic head 1 and an optical beam (b).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic field capable of controlling a relative angle by detecting a relative angle between an optical axis of a light beam applied to a magneto-optical recording medium and a recording surface of the magneto-optical recording medium. The present invention relates to a head and a magneto-optical recording / reproducing device.

[0002]

2. Description of the Related Art When the relative angle between the optical axis of a light beam in a magneto-optical recording / reproducing apparatus and the recording surface of a magneto-optical recording medium deviates from a right angle, crosstalk from an adjacent track occurs, and an error in reproduced data occurs. To increase. Causes of deviation from the right angle include warpage of the magneto-optical recording medium and inclination of the mechanism of the magneto-optical recording / reproducing apparatus. As a device for solving this problem, for example, there is a recorded information reading device disclosed in Japanese Patent Publication No. 7-66554. This device attaches a pair of light emitting element and light receiving element to an optical pickup separately from a light beam for information reproduction, and irradiates the optical recording medium from the light emitting element with diffused light,
This configuration guides the reflected light to the light receiving element. With this configuration, the relative angle is detected from the output signal of the light receiving element, and the relative angle is controlled so that the relative angle becomes a right angle.

[0003]

However, when the light-emitting element and the light-receiving element for detecting the relative angle are attached to the optical pickup, the optical pickup becomes relatively large, and it is difficult to increase the access speed and reduce the size of the apparatus. Met.

Further, when the light emitting element and the light receiving element for detecting the relative angle are attached to the optical pickup, the following problem occurs. That is, a problem in the case where the tilt sensor 82 including the light emitting element and the light receiving element for detecting the relative angle described above is provided on a conventional optical pickup will be schematically described with reference to FIG.

First, when the optical pickup 81 is located on the inner periphery of the magneto-optical disk 83, the objective lens actuator 8
1a on the same track Ti as the objective lens 81b,
It is necessary to arrange the inclination sensor 82. Thus, the inclination of the magneto-optical disk 83 with respect to the light beam focused on the track Ti can be detected. However, even on the same track Ti, since the position is not the same as that of the objective lens 81b, a tilt detection error corresponding to that position occurs. Further, since the tilt sensor 82 is arranged beside the objective lens actuator 81a, the area occupied by the optical pickup 81 increases, which hinders miniaturization and weight reduction of the optical pickup.

Next, when the optical pickup 81 moves to the outer periphery of the magneto-optical disk 83, the curvature of the track changes, so that the tilt sensor 82 comes off the same track To as the objective lens 81b. Since this detects a tilt on a different track, a tilt detection error further increases.

In view of the above problems, it is an object of the present invention to reduce the size of an optical pickup, control the relative angle,
It is an object of the present invention to provide a magnetic head and a magneto-optical recording / reproducing device with a small detection error.

[0008]

According to a first aspect of the present invention, there is provided a magnetic head for generating a magnetic field for magneto-optical recording, wherein the tilt for detecting the tilt of the magnetic head when the magnetic head comes into contact with a magneto-optical recording medium is detected. A detection unit is provided on the magnetic head.

A magneto-optical recording / reproducing apparatus according to claim 2 is
In a magneto-optical recording / reproducing apparatus having a magnetic head for generating a magnetic field for magneto-optical recording, a tilt detecting means provided on the magnetic head for detecting a tilt of the magnetic head when coming into contact with a magneto-optical recording medium And relative angle control means for controlling a relative angle between an optical axis of a light beam applied to the magneto-optical recording medium and the magneto-optical recording medium based on a detection result of the tilt detecting means. Features.

The magneto-optical recording / reproducing apparatus according to claim 3 is
3. The magneto-optical recording / reproducing apparatus according to claim 2, wherein the relative angle control means controls the relative angle only when the magneto-optical recording medium is loaded.

The magneto-optical recording / reproducing apparatus according to claim 4 is
The magneto-optical recording and reproducing apparatus according to claim 2, wherein the relative angle control means interrupts or resets the control of the relative angle when the relative angle exceeds a predetermined range.

A magneto-optical recording / reproducing apparatus according to claim 5 is
3. The magneto-optical recording / reproducing apparatus according to claim 2, wherein the inclination detecting means includes a reference surface provided in an optical path between the light emitting element and the light receiving element, and the magnetic field is determined based on a change in the optical path from the reference surface. The tilt of the head is detected, and the reference surface is mounted so as to move integrally with the magnetic head.

[0013] The magneto-optical recording and reproducing apparatus according to claim 6 is
3. The magneto-optical recording / reproducing apparatus according to claim 2, wherein the tilt detecting means includes a piezoelectric element at each of a plurality of bent portions of a member for supporting the magnetic head, and the magnetic head based on a signal detected from each piezoelectric element. It is characterized by detecting the inclination of.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION

(Embodiment 1) A magnetic head for magneto-optical recording and a magneto-optical recording / reproducing apparatus according to the present invention will be described with reference to FIGS. FIG.
1 shows a magneto-optical recording / reproducing apparatus according to the present embodiment. The magneto-optical disk 7 is loaded on a turntable 12, fixed by a chucking member (not shown), and rotated by a spindle motor 13. A light beam b is emitted from the optical pickup 6 to the magneto-optical disk 7 via the objective lens, and a magnetic field is generated from the magnetic head 1 to record and reproduce information. The driver circuit 9 drives the feed motor 8 based on a command from the CPU 11 to move the optical pickup 6 to a predetermined position on the magneto-optical disk 7. Also, CP
In response to an instruction from U11, the driver circuit 5 drives the magnetic head lifting / lowering mechanism 4, and lowers or raises the magnetic head 1 for magneto-optical recording attached to the leaf spring 18 on the magneto-optical disk 7. From the loading mechanism 17, a signal indicating whether or not the magneto-optical disk 7 is loaded is sent to the CPU 1 by the CPU 1.
1 and the whole operation is started based on this signal.

The divergent light emitted from the magnetic head tilt detecting means 2 provided immediately above the magnetic head 1 is reflected by the reference surface 10 having a reflecting surface, and the reflected light returns to the magnetic head tilt detecting means 2 again. Come. The reference surface 10 is attached to an arm 19 that moves integrally with the optical pickup 6. This makes it possible to reduce the size of the reference surface 10 as compared with the case where the reference surface 10 is mounted on the ceiling of the apparatus main body, and to easily process and adjust the reference surface 10 for detecting the inclination of the magneto-optical disk 7. The optical pickup 6 is adjusted in advance so that the optical axis of the reference plane 10 and the light beam b are at a right angle. Since the magnetic head 1 is in contact with the magneto-optical disk 7, the tilt of the magnetic head 1 is the same as the tilt of the surface of the magneto-optical disk 7. In the present embodiment, the magnetic head 1
Is included in the contact state.
As a result, detection signals v1 and v2 described later are detected,
The gradient detection signal v3 input to the differential amplifier 3 is sent to the driver circuit 16. The driver circuit 16 drives the angle adjusting motor 15 based on the tilt detection signal v3 so that the relative angle between the magnetic head 1 and the light beam b becomes a right angle, and tilts the spindle motor 13 supported by the support means 14. Control the relative angle. By providing the magnetic head tilt detecting means 2 on the magnetic head 1 as described above, the relative angle detecting means between the light beam and the magneto-optical recording medium can be removed from the optical pickup.
The size can be reduced. As shown in FIG. 6, the positions where the magnetic head tilt detecting means 2 and the reference surface 10 are attached may be exchanged, and the diffused light may be irradiated from the upper part to the lower part of the page.

The magnetic head tilt detecting means 2 attached to the magnetic head 1 will be described in more detail with reference to FIG. In FIG. 2A, divergent light emitted from the light emitting element 2a is reflected by a reference surface 10 having a reflecting surface,
Since the angle of the reflected light changes according to the inclination of the magnetic head 1, the distribution of the amount of light incident on the light receiving elements 2b and 2c changes. The detection signal v1 detected by the light receiving element 2b and the detection signal v2 detected by the light receiving element 2c are
And an inclination detection signal v3 is obtained. Arrows in the figure indicate ends of the divergent light beam and the reflected light beam. In the case of FIG.
The magnetic head 1 is tilted right downward on the paper, and the light receiving element 2
The reflected light hardly enters the light receiving element 2b, and most of the reflected light enters the light receiving element 2c. Therefore, v2 is larger than the detection signal v1, and the inclination detection signal v3 shows a negative value according to the inclination of the magnetic head 1. In order to reduce the detection error, it is desirable that the light emitting element 2 is on the optical axis of the light beam b from the optical pickup.

In the case of FIG. 2B, the magnetic head 1 is horizontal on the paper surface, and equal amounts of reflected light are incident on the light receiving elements 2b and 2c. Therefore, the detection signals v1 and v2 are equal,
The inclination detection signal v3 indicates a value of zero. In the case of FIG. 2C, the magnetic head 1 is tilted to the left and down on the paper, and is incident on the light receiving element 2b, and hardly incident on the light receiving element 2c. Therefore, the detection signal v1 is larger than v2, and the inclination detection signal v3 shows a positive value according to the inclination of the magnetic head 1.

If this magnetic head tilt detection signal v3 is input to the driver circuit 16 in FIG. 1, the tilt of the spindle motor 13 can be controlled so that the tilt of the magnetic head 1 becomes equal to the reference plane 10. Thus, the magneto-optical disk 7 in contact with the magnetic head 1 can always be kept parallel to the reference plane 10, and the relative angle with the light beam b can be controlled at a right angle. In the present embodiment, an example in which the angle of the spindle motor 13 is controlled has been described. However, the present invention is not limited to this. At least the angle between the optical pickup 6 and the reference surface 10 is fixed, and the angles of other parts are controlled. Needless to say, it should be done.

FIG. 3 is a diagram for explaining the magnetic head 1 in more detail. FIG. 3A is a perspective view of a line contact type magnetic head, and FIG. 3B is a cross-sectional view in the moving direction. In FIG. 3A, the lower portion A of the slider member 21 is processed so as to make line contact in the moving direction of the magneto-optical disk. In FIG. 3B, the slider member 21
Is provided with a magnetic head including a magnetic core 22 and a coil 23. If the magneto-optical disk is slid by the two line contact portions A, the tilt of the magneto-optical disk becomes the tilt of the magnetic head and can be detected by the magnetic head tilt detecting means 2 provided on the magnetic head (not shown). .

FIG. 3 shows another example of a magnetic head.
(C) and (d) show. FIG. 3C is a perspective view of a point contact type magnetic head, and FIG. 3D is a cross-sectional view in the moving direction. In FIG. 3C, the point contact portions B provided at the lower portion of the slider member 21 are provided at four corner portions of the slider member 21. 3D, similarly to FIG. 3B, a magnetic head including a magnetic core 22 and a coil 23 is provided inside the slider member 21. If the magnetic head slides on the magneto-optical disk by the four point contact portions B, the tilt of the magneto-optical disk becomes the tilt of the magnetic head in the same manner, and can be detected by the magnetic head tilt detecting means 2.

FIG. 4 is a flowchart showing the operation of the magneto-optical recording / reproducing apparatus shown in FIG. First, a magneto-optical disk is loaded into the device (step S1), and the spindle motor is rotated (step S2). The optical pickup is moved to a predetermined position on the magneto-optical disk (step S3), and the magnetic head is lowered (step S4). Next, the relative angle control between the light beam and the magneto-optical disk is turned on and started (step S5). At this time, the control of the relative angle is turned on only when the magneto-optical disk is loaded in step S1 and the magnetic head is lowered in step S4. This is because, if the relative angle is controlled in a state where the magneto-optical disk is not in contact with the magnetic head, the angle changes abnormally greatly. Next, the inclination of the magnetic head is detected (step S6), and the angle control is always performed so that the angle difference from the reference plane becomes zero (step S7). Next, it is detected whether or not the angle of the controlled spindle motor is within a normal range (step S8). If abnormal, an abnormal operation signal is output to the CPU, and an abnormal operation is output (step S9). The angle control is turned off (step S11). Further, the relative angle control may be reset, the relative angle may be returned to the initial value, and the control may be turned on again. Next, if the angle is within the normal range, the detection of the tilt of the magnetic head (step S6) and the angle control (step S7) are repeated until an instruction to end recording or reproduction is issued (step S10). When an instruction to end recording or reproduction is issued, the relative angle control is turned off (step S11), and the process ends.

The same effect can be obtained by replacing the magnetic head tilt detecting means 2 shown in FIG. 2 with the configuration shown in FIG. 5A. Piezoelectric elements 2d and 2e are attached to a leaf spring 18 that supports the magnetic head 1 in contact with the magneto-optical disk 7, and a gimbal spring 51 is provided at the tip of the leaf spring 18 and is fixed to the magnetic head 1.

The gimbal spring 51 allows the magnetic head 1
To press the magnetic head 1 against the magneto-optical disk 7. Thus, the degree of bending of the leaf spring 18 that is bent according to the inclination of the magnetic head 1 can be electrically detected. Here, as shown in FIG. 5B, since the magnetic head 1 may move in parallel without tilting, the tilt of the magnetic head 1 is precisely the difference between the angles α and β (α −β). Therefore, in FIG. 5A, the angle α is detected based on the voltage (v5-v6) detected from the piezoelectric element 2d, and the angle β is detected based on the voltage (v7-v8) detected from the piezoelectric element 2e. Then, this potential difference (v5-v6)-
By outputting (v7-v8) as the detection signal v3, only the angle between the magnetic head and the optical axis can be detected. When the detection signal v3 is zero, the inclination of the magnetic head is zero because the angles α and β are equal. Therefore, FIG.
When the magnetic head moves in parallel without tilting as shown in (b), the difference between the angles α and β becomes zero. On the other hand, when the magnetic head tilts, the magnetic head 1 changes in accordance with the positive or negative voltage of the detection signal v3. Direction and magnitude of the inclination can be detected. The leaf spring itself may be constituted by a piezoelectric element. Also, the mounting directions of the piezoelectric elements 2d and 2e may be changed according to the inclination direction to be detected, and need not be limited to the mounting directions in FIG.

FIG. 7 illustrates the relative positions of the light beam and the magnetic head tilt detecting means in the present apparatus. The light emitting element of the magnetic head tilt detecting means 2 is disposed on the magnetic head 1 disposed directly above the objective lens 6b on the objective lens actuator 6a, and the optical axis of the light beam substantially coincides with the optical axis of the light emitting element. This makes it possible to directly detect the tilt of the magneto-optical disk 7 at the position where the light beam is focused. Accordingly, accurate tilt detection with less error can be performed as compared with the conventional device. Further, since the light beam condensing position and the tilt detection position are the same, no deviation of the detection track due to the curvature occurs on the inner circumference or the outer circumference of the magneto-optical disk 7.
Accurate tilt detection can be performed on the entire magneto-optical disk 7. Further, since the magnetic head tilt detecting means 2 is disposed right above the objective lens actuator 6a, the magnetic head tilt detecting means 2 can be removed from the optical pickup 6, and the occupied area of the optical pickup can be reduced accordingly.
This contributes to downsizing and weight reduction of the pickup.

[0025]

According to the first or second aspect of the present invention, the inclination detecting means is provided on the magnetic head, so that the means for detecting the relative angle between the light beam and the magneto-optical recording medium can be used as the optical pickup. , The size of the optical pickup can be reduced.

According to the third or fourth aspect of the present invention, since the control of the relative angle when the magneto-optical disk is not in contact with the magnetic head can be prohibited, it is possible to prevent the angle from abnormally largely changing. It is possible to prevent the device and the magneto-optical disk from being damaged.

According to the fifth aspect of the present invention, since the reference surface can be made smaller, processing and adjustment of the reference surface can be facilitated.

According to the sixth aspect of the present invention, it is possible to remove a signal due to the vertical fluctuation of the optical disk and detect only a signal due to the inclination.

[Brief description of the drawings]

FIG. 1 is a diagram showing a magneto-optical recording / reproducing apparatus of the present invention.

FIG. 2 is a diagram for explaining an operation of a magnetic head tilt detecting means provided on the magnetic head for magneto-optical recording in FIG.

FIG. 3 is a diagram showing a structure of a magnetic head in FIG. 1;

FIG. 4 is a flowchart showing the operation of the magneto-optical recording / reproducing apparatus in FIG.

FIG. 5 is a diagram for explaining an operation of a magnetic head for magneto-optical recording and a magnetic head tilt detecting means according to another embodiment.

FIG. 6 is a diagram illustrating an operation of a magnetic head tilt detection unit according to another embodiment.

FIG. 7 is a diagram for explaining a relative position between a light beam and a magnetic head tilt detection unit.

FIG. 8 is a diagram for explaining a conventional problem.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Magnetic head 2 Magnetic head inclination detecting means 2a Light emitting element 2b Light receiving element 2c Light receiving element 3 Differential amplifier 6 Optical pickup 7 Magneto-optical disk 10 Reference plane 13 Spindle motor 15 Angle adjustment motor 16 Driver circuit

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Toshiharu Inui 22-22, Nagaikecho, Abeno-ku, Osaka-shi, Osaka Inside Sharp Corporation (72) Inventor Tomoyuki Miyaku 22-22, Nagaikecho, Abeno-ku, Osaka-shi, Osaka (72) Inventor Yasuo Nakata 22-22 Nagaikecho, Abeno-ku, Osaka-shi, Osaka Sharp Corporation

Claims (6)

[Claims] 1. A magnetic head for generating a magnetic field for magneto-optical recording, wherein tilt detecting means for detecting a tilt of the magnetic head when the magnetic head comes into contact with a magneto-optical recording medium is provided on the magnetic head. Magnetic head. 2. A magneto-optical recording / reproducing apparatus comprising a magnetic head for generating a magnetic field for magneto-optical recording, wherein the tilt of the magnetic head provided on the magnetic head when the magnetic head comes into contact with a magneto-optical recording medium is determined. Inclination detecting means for detecting, relative angle control means for controlling a relative angle between an optical axis of a light beam applied to the magneto-optical recording medium and the magneto-optical recording medium based on a detection result of the inclination detecting means; A magneto-optical recording / reproducing device comprising: 3. The magneto-optical recording and reproducing apparatus according to claim 2, wherein the relative angle control means controls the relative angle only when the magneto-optical recording medium is loaded. 4. The magneto-optical recording / reproducing apparatus according to claim 2, wherein the relative angle control means interrupts or resets the control of the relative angle when the relative angle exceeds a predetermined range. . 5. The tilt detecting means includes a reference plane provided in an optical path between a light emitting element and a light receiving element, and detects a tilt of the magnetic head based on a change in an optical path from the reference plane. 3. The magneto-optical recording / reproducing apparatus according to claim 2, wherein the reference surface is mounted so as to move integrally with the magnetic head. 6. The tilt detecting means includes a piezoelectric element at each of a plurality of bent portions of a member supporting the magnetic head, and detects the tilt of the magnetic head based on a signal detected from each piezoelectric element. 3. The magneto-optical recording / reproducing apparatus according to claim 2, wherein: