JPH07121925A - Magneto-optical disk device - Google Patents

Abstract

(57) [Summary] (Correction) [Purpose] The weight of the moving part of the optical head can be reduced, and the seek speed during magnetic field modulation recording can be greatly improved, and the device can be made thinner. The present invention also provides a magneto-optical disk device that requires less heat and consumes less power. A first bias magnetic field generator that applies a bias magnetic field for magnetic field modulation recording and a second bias magnetic field that applies a bias magnetic field for optical modulation recording to a minute region where a light spot is formed on a magneto-optical recording medium. In a magneto-optical disk device having the bias magnetic field generator of FIG. 1, a drive source 101 for moving the first bias magnetic field generator in the radial direction of the recording medium and a second bias magnetic field generator in the radial direction of the recording medium. It is characterized by being separately equipped with a drive source for moving.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to forming a light spot by irradiating a recording medium with a laser beam from an optical head which is movable relative to the recording medium, and to a minute area where the light spot is formed. The present invention relates to a magneto-optical disk device including first and second bias magnetic field generators for recording information with different modulation methods. [Prior Art] Conventionally, this type of magneto-optical disk device is
A constant magnetic field is applied to the recording area of the magneto-optical recording medium by a bias magnetic field generator, and a laser beam modulated by recording information is irradiated from the optical head to the recording area. For example, a first 3.5-inch magneto-optical disk. Generation ISO
Also for a magneto-optical recording medium based on (hereinafter referred to as ISO) recording by an optical modulation method, a constant laser beam is applied to a recording area from an optical head, and a magnetic field modulated by recording information is biased. It is necessary to ensure compatibility that information can be recorded and reproduced even with respect to a magneto-optical recording medium that is recorded by a so-called magnetic field modulation method, which is applied from the magnetic field generator to the recording area.

Therefore, in the conventional magneto-optical disk device, as shown in FIGS. 6 to 9, a structure has been proposed in which two kinds of bias magnetic field generators are used side by side. Here, a magnetic field modulation type recording bias magnetic field generating device A is provided as the first bias magnetic field generating device, and an optical modulation type recording bias magnetic field generating device B is provided as the second bias magnetic field generating device. ing.

As is well known, the bias magnetic field generator A supports a flying slider 2 having a magnetic head as a bias magnetic field generator mounted on a support member 2b via a support spring 2a as a load beam. The support member 2b is rotatably supported on the carriage 10 having the optical system via the rotary shaft 12.
A torsion coil spring (not shown) is provided around the rotary shaft 12 so as to bias the flying slider 2 toward the disk surface.

The carriage 10 is constructed so as to be movable along the guide rail 8 in the disk radial direction (X direction in the drawing). In addition, the guide rail 8
Both ends thereof are fixed to the base 9. Spindle motor 8
0 allows the magneto-optical disk 40 housed in the disk cassette 30 to be rotatably mounted thereon. The spindle motor 80 is
It is supported movably up and down (Y direction in the figure), and when the disc cassette 30 is not loaded in the device body, it is retracted to the lower part to avoid interference with the disc cassette 30 inserted into the device body. There is. When the disc cassette 30 is inserted all the way into the main body of the apparatus, the spindle motor lifting mechanism (not shown) moves the spindle motor 80 upward to clamp the magneto-optical disc 40.

On the other hand, when the disc cassette 30 is inserted into the main body of the apparatus, the magnetic head of the bias magnetic field generator A must also be retracted. Therefore, the base 9 has
As a repelling mechanism, a solenoid drive mechanism 53 having a retract lever 50 is provided. When the energization of the solenoid 54 is stopped, as shown in FIG. 8, the retracting lever 50 is pulled down by the restoring force of the compression spring 55, and the roll-shaped engaging member provided at the rear end of the support member 2b. The magnetic head is retracted by pushing down the contact portion 7. When the solenoid 54 is energized,
Since the retract lever 50 is pulled up, the engaging contact portion 7
Therefore, the flying slider 2 mounted with the magnetic head is in a state of descending on the disk surface.

The bias magnetic field generator B includes a carriage 10
The coil 4 provided in the core member 1 is composed of a substantially U-shaped core member 1, and both ends 1a and 1b of the core member 1 are located on both sides of the magneto-optical disk 40. FIG. 9 is an enlarged cross-sectional view in the vicinity of the minute area where the above-mentioned light spot is formed. An objective lens 6 focuses the light beam on the minute area. Reference numeral 11 is an upper yoke provided on an upper part of a magnetic circuit (not shown) for driving the objective lens 6,
A leakage magnetic field from the driving magnetic circuit to a minute area is prevented. By bringing the end 1b of the core member 1 close to the upper yoke 11, the upper yoke 11 also serves as a part of the magnetic circuit of the bias magnetic field generator B.

When the magneto-optical disk 40 is loaded into the main body of the apparatus, first, the control track of the magneto-optical disk 40 is reproduced to determine whether the disk is a magnetic field modulation recording disk or a light modulation recording disk, and to perform magnetic field modulation. In the case of a recording disk, energization of the solenoid 54 is started, and the flying slider 2 having a magnetic head mounted thereon is lowered onto the disk. In the case of an optical modulation recording disk, the bias magnetic field generator B is used without energizing the solenoid 54.

[0008]

However, in such a magneto-optical disk device, the electromagnet of the bias magnetic field generating device B causes 200 to 400 Oe on the surface of the recording medium.
This electromagnet had to be large and heavy because it had to produce a high magnetic flux density (ISO standard). Further, the use of an electromagnet has a restriction that the carriage must be made of a material having good thermal conductivity in order to suppress heat generated by driving the electromagnet.

Further, in the magneto-optical disk device, the time required for the optical head to move between designated tracks on the disk, that is, the seek time, is an important factor of the processing speed. For that purpose, the weight of the movable portion of the optical head has a great influence, and how to reduce the weight of this portion is one of the points that determines the performance of the drive. In the movable part having the above-described configuration, restrictions on selection of a lightweight material, increase in weight due to addition of the bias magnetic field generator B, and deterioration of frequency characteristics of the movable part due to imbalance in shape. A problem occurred and it was difficult to significantly improve the seek time reduction.

[0010]

According to the present invention, a recording medium is irradiated with a laser beam from an optical head movable with respect to the recording medium to form a light spot, and the light spot is formed. In a magneto-optical disk device having a first bias magnetic field generator for applying a magnetic field modulation recording bias magnetic field to a minute area and a second bias magnetic field generator for applying an optical modulation recording bias magnetic field,
A drive source for moving the first magnetic field generating device in the radial direction of the recording medium and a drive source for moving the second bias magnetic field generating device in the radial direction are separated and independent, and a second bias magnetic field is generated. The apparatus is driven only when the light modulation recording medium is used.

[Embodiment] A concrete embodiment of the present invention will be described below with reference to FIGS. In the figure, the same components as those of the related art will be designated by the same reference numerals and detailed description thereof will be omitted. In FIG. 1, 1
01 is a stepping motor, 102 is a guide rail, 1
Reference numeral 03 is a movable member, 104 is a permanent magnet, and 105 is a lead screw. The bias magnetic field generator A is a floating magnetic head having almost the same configuration as the conventional example, and is supported so as to be vertically rotatable with respect to the disk.

The second bias magnetic field generator B uses a permanent magnet 104, and its polarity is as shown in FIG.
The disks are arranged so that the N pole and the S pole are aligned in the radial direction (arrow in the figure) of the disk. The permanent magnet 104 is fixed to the movable member 103, and the movable member 103 is slidably mounted on the guide rail 102. Also,
As shown in FIG. 3, the movable member 103 is partially held in engagement with the lead screw 105 that also serves as the shaft of the stepping motor 101.
It is configured to move in the disk radial direction by the rotation of. Stepping motor 101, guide shaft 10
2 and the lead screw 105 are held by a holding member 106, and the holding member 106 is fixed to a base 130 of the drive device.

Before the disk cartridge 30 is inserted, the solenoid 53 is not energized, and the flying slider 2 having the magnetic head mounted thereon is retracted upward. At this time, the optical modulation bias magnetic field generator B is usually located outside the disk diameter (behind the drive device) so as not to affect the magnetic field generated by the bias magnetic field generator A during magnetic field modulation recording. It is evacuating. This bias magnetic field generator B is at the time when the device power is turned on or when the bias magnetic field generator B is
When the position initialization signal (reset) is detected, the position is set to the above-mentioned position, and subsequent position control in the radial direction is performed by a drive pulse to the stepping motor with reference to this position.

At the same time when the magneto-optical disk cartridge 30 is inserted into the apparatus, a medium identification notch (not shown) previously provided in the cartridge 30 is detected by a sensor provided in the drive apparatus, and the inserted recording is performed. Medium is
Whether the medium for magnetic field modulation recording or the medium for optical modulation recording is discriminated, and when discriminated as the medium for magnetic field modulation recording, the solenoid 53 is energized after the disk rotation rises, and the floating magnetic head is lowered onto the surface of the recording medium. Let The magnetic head uses a flying slider to generate a magnetic field according to an information signal while maintaining a constant distance from the disk, and performs recording on the disk. Next, when the inserted recording medium is identified as the optical modulation recording medium, the solenoid 53 is not energized and the flying head remains retracted. At this time, the stepping motor 1 of the bias magnetic field generator B
A drive signal is sent to 01, and the movable member 103 provided with the permanent magnet 104 moves onto the disk (near the optical head).

A bias magnetic field applying method using the permanent magnet 104 in the structure of the present invention will be described with reference to FIG. First, when erasing the disc information (the erasing magnetic field direction of the disc is the N pole), the carriage linear motor is driven in order to move the optical head to the erasing position on the disc. At the same time, the stepping motor 101 is driven so that the moving member 103 provided with the bias magnetic field applying permanent magnet 104 is located at the position shown in FIG.
At this position, the vertical component of the N pole in the figure is applied to the disk erasing portion on the center of the objective lens 6.
At this time, information in a desired track is erased by modulating the laser power.

Next, for recording information, the movable member 103 is moved to the position shown in FIG. 3B while keeping the objective lens position unchanged. At this position, the vertical component of the south pole in the direction opposite to that at the time of erasing is applied to the disc, and information is recorded by modulating the laser power according to the recorded information. The permanent magnet for applying the bias magnetic field is moved according to the movement of the optical head only when recording or erasing information on the disc, and is not driven when reproducing the disc information.

FIG. 5 shows another embodiment of the present invention. In FIG. 5, a bias magnetic field generating permanent magnet 10 is shown.
4 is fixed to the movable member 103, and the movable member 103 is fixed to the steel belt 123. Steel belt 1
23 is vertically supported by pulleys 121 and 125. A tension pulley 122 is provided to keep the tension of the steel belt 123. The pulley 121 is fixed to the shaft of the stepping motor 120, and the steel belt can be driven by the rotation of the motor to move the permanent magnet 104 in the radial direction of the disk.

This embodiment is characterized in that the movable member having a permanent magnet is moved in the radial direction of the disk by a steel belt instead of the lead screw, which is directly driven. The method of erasing and recording the
The process can be performed in the same manner as in the above embodiment.

[0019]

As described above, according to the present invention,
An optical head that is movable in the radial direction with respect to the magneto-optical recording medium irradiates the recording medium with laser light to form a light spot, and magnetic field modulation recording is performed on a minute area where the light spot is formed. In a magneto-optical disk device having a first bias magnetic field generator that applies a bias magnetic field and a second bias magnetic field generator that applies a bias magnetic field for optical modulation recording, the first bias magnetic field generator is used in the radial direction of the recording medium. Drive source for moving to
Since a drive source for moving the bias magnetic field generating device in the radial direction of the recording medium is separately provided, it is possible to reduce the weight of the movable part of the optical head, and particularly in seek speed during magnetic field modulation recording. , Can be greatly improved. Further, the permanent magnet is moved by a lead screw or a belt, and the drive source thereof is arranged at the rear of the device, so that the device can be made thin. Furthermore, by using a permanent magnet as the means for generating the bias magnetic field,
Compared with the electromagnet method, less heat is generated and power consumption can be suppressed.

[Brief description of drawings]

FIG. 1 is a perspective view showing a configuration of a magneto-optical disk device according to a first embodiment of the present invention.

FIG. 2 is an enlarged perspective view showing an arrangement portion of permanent magnets in FIG.

FIG. 3 is a cross-sectional view showing a method of supporting a movable member.

FIG. 4 is a plan view showing a positional relationship of bias magnets at the time of erasing and recording information on an optical modulation recording medium.

FIG. 5 is a perspective view of a magneto-optical disk device configuration showing a second embodiment of the present invention.

FIG. 6 is a plan view showing a conventional magneto-optical disk device.

FIG. 7 is a side view showing a usage state of a conventional magneto-optical disk device.

FIG. 8 is a side view showing another usage state as well.

FIG. 9 is an end view showing a main part of a conventional magneto-optical disk device.

[Explanation of symbols]

 2 Flying slider 6 Objective lens 30 Disc cassette 40 Magneto-optical disc 53 Solenoid drive mechanism 101, 120 Stepping motor 102 Guide shaft 103 Moving member 104 Permanent magnet 105 Lead screw 130 Device base 121, 125 Pulley 123 Steel belt

Claims (4)

[Claims] 1. A recording medium is irradiated with laser light from an optical head that is movable in the radial direction with respect to a magneto-optical recording medium to form a light spot, and a minute area where the light spot is formed. In a magneto-optical disk device having a first bias magnetic field generator for applying a magnetic field modulation recording bias magnetic field and a second bias magnetic field generator for applying an optical modulation recording bias magnetic field, a first bias magnetic field generator is provided. A magneto-optical disk device comprising a drive source for moving the recording medium in the radial direction and a drive source for moving the second bias magnetic field generator in the recording medium in the radial direction separately. . 2. The magneto-optical disk device according to claim 1, wherein the first bias magnetic field generator is mounted on the optical head. 3. The second bias magnetic field generating device is movable in a direction of a recording medium by rotation of a lead screw provided on a parallel shaft parallel to the radial direction of the recording medium. Magneto-optical disk device. 4. The magneto-optical device according to claim 1, wherein the second bias magnetic field generator is held by a belt provided parallel to the radial direction of the recording medium and is movable in that direction. Disk device.