JPH07320328A - Magneto-optical disc - Google Patents

Abstract

PURPOSE:To shorten the time required for seek operation while increasing the rotational speed of a disc-like recording medium by providing means for shifting a modulation coil following up an objective lens. CONSTITUTION:A modulation coil 11 applies a modulated field to a position where a light beam projected from a light source is focused through an objective lens 24. A modulation coil shifting means comprises a drive means 33, a modulation coil holding mechanism, a field position detecting means 34, and a control section 23 and shifts the modulation coil 11 in the radial direction of a magneto- optical disc 2 following up the movement of position on the disc 2 with light beam being irradiated. correctly to the light beam irradiating position.

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 for recording desired information by irradiating a surface of a disk-shaped recording medium with a modulation magnetic field and a light beam to apply a thermomagnetic recording method. It relates to the device.

[0002]

2. Description of the Related Art Conventionally, in a magneto-optical disk device to which a thermomagnetic recording method is applied, there is a magneto-optical disk device which is designed to shorten the time required for writing by overwriting and recording desired information. This magneto-optical disk device is configured as shown in FIG. That is, in FIG. 4, a magneto-optical disk device 1 includes a magneto-optical disk 2 which is a disk-shaped recording medium for recording and reproducing information, and a disk motor 3 which holds the magneto-optical disk 2 and rotationally drives it at a predetermined rotation speed. The chassis 4 holds the disk motor 3 together with other components, the optical block 5 fixed to the chassis 4, and the movable portion 6.

The optical block 5 is held at the end of the chassis 4 at a predetermined distance from the disk motor 3, is parallel to the information recording surface of the magneto-optical disk 2, and faces the rotation axis of the disk motor 3. To emit a light beam. Further, the return light beam from the disk 2 which traces the optical path of this light beam in the opposite direction is received by the optical block 5, and the tracking error and the focus error are detected from this return light beam, and further the recording information is detected. ing. Furthermore, the optical block 5
Emits a constant light amount of this light beam continuously during reproduction, and intermittently increases the light amount from the light amount during reproduction and emits the light beam. As a result, the magneto-optical disk device 1 is adapted to record desired data by applying the pulse train method.

The movable portion 6 is arranged between the disk motor 3 and the optical block 5, and a pair of linear actuators 7 are arranged at both ends of the chassis 4 in parallel with the light beam emitted from the optical block 5. The driving force of the pair of linear actuators 7 is configured to move the holding member 8 in the radial direction of the magneto-optical disk 2 along the optical path of the light beam during seek or the like.

The holding member 8 receives a light beam from a through hole formed on the optical block 5 side, and the right-angle prism 9 arranged on the optical path of the light beam bends the light beam to bend the magneto-optical disk 2. The light is emitted toward the information recording surface. Further, by disposing the through hole and the right-angled prism 9 in this way, the holding member 8 bends the return light beam obtained from the information recording surface at the right-angled prism 9 and emits it toward the optical block 5 through the through-hole. It has become.

Further, the holding member 8 has a biaxial actuator 10 arranged above the rectangular prism 9.
The biaxial actuator 10 holds the objective lens on the optical path of the light beam emitted toward the magneto-optical disk 2. As a result, in the magneto-optical disc device 1, the light beam is converged on the information recording surface of the magneto-optical disc 2 by the action of this objective lens, and the return light beam obtained from the magneto-optical disc 2 is received by this objective lens. It is configured to emit to the rectangular prism 9.

Further, the holding member 8 is the magneto-optical disk 2
The modulation coil 11 is held so as to face the objective lens with the lens sandwiched therebetween. That is, as shown in FIG. 5, in the holding mechanism of the modulation coil 11, a gimbal 12 is formed by elongating a member having a spring property toward the tip, and a gimbal 12 is held. The modulation coil 11 is fixed to the member 8, and the modulation coil 11 is fixed to the tip of the gimbal 12 and pressed against the magneto-optical disk 2.

The modulation coil 11 is formed on a predetermined member 14, and when the magneto-optical disk 2 rotates, it slides on the magneto-optical disk 2 or floats from the magneto-optical disk 2 by a minute distance. In this state, a modulation magnetic field is formed at the irradiation position of the light beam according to the drive current supplied through the lead wire 15. Thereby, in the magneto-optical disk 2, the linear actuator 7 is driven to move the irradiation position of the light beam and the position of the modulation magnetic field in the radial direction of the magneto-optical disk 2, and the desired recording is performed by applying the thermomagnetic recording method. Information is recorded on the track.

According to the magneto-optical disk device 1 thus constructed, the light beam emitted from the optical block 5 is guided to the reflection mirror 9 through the through hole of the movable portion 6,
Here, after being bent toward the information recording surface of the magneto-optical disk 2, it is converged on the information recording surface by the objective lens. At the irradiation position of the light beam, a predetermined modulation magnetic field is applied by the modulation coil 11 at the time of recording, whereby the polarity of the modulation magnetic field is applied to the irradiation position of the light beam intermittently irradiated by the thermomagnetic recording method. A pit corresponding to is formed and an information signal is recorded.

In the case of recording information in this way, in the magneto-optical disk device 1, by driving the linear actuator 7, the position of the modulation magnetic field is moved in the radial direction of the magneto-optical disk 2 together with the irradiation position of the light beam. It can be moved, and seeks to a desired recording track.

Further, after the seek, when the light amount of the light beam is increased and information is recorded, the light beam is irradiated onto the pit which has been formed before, and a modulation magnetic field is applied,
As a result, the information recorded until then is overwritten.

Further, the return light beam obtained from the magneto-optical disk 2 by irradiating the light beam reversely follows the optical path of this light beam, and the optical block 5 detects a tracking error and a focus error. The biaxial actuator 10 is driven by the focus error, and tracking control and focus control are thereby performed.

[0013]

However, the magneto-optical disk device 1 having such a structure has the following problems.

That is, in this type of magneto-optical disk device, it is necessary to apply a modulating magnetic field of a specified value or more to the irradiation position of the light beam, and in order to strengthen this modulating magnetic field,
It is necessary to increase the size of the modulation coil 11 and increase the drive current of the modulation coil 11. However, if the size of the modulation coil 11 is increased and the drive current is increased as described above, it becomes difficult to quickly switch the polarity of the modulation magnetic field according to the recorded information, and the power consumption increases and the amount of heat generation also increases.
Further, if the modulation coil 11 is increased in size in this manner, it becomes difficult to hold the modulation coil 11 close to the magneto-optical disk 2.

For this reason, in the conventional magneto-optical disk device 1, by holding the small-sized modulation coil 11 close to the magneto-optical disk 2, the irradiation position of the light beam is surely equal to or higher than the predetermined value. To ensure.

However, at the light beam irradiation position, tracking control is performed to move the objective lens,
The relative position with respect to the modulation coil 11 follows the eccentricity of the magneto-optical disk 2 and changes. When seeking,
After the linear actuator 7 is driven to roughly adjust the position, the objective lens is moved to finely adjust the position. In this case as well, the relative position with respect to the modulation coil 11 changes due to the fine position adjustment.

For this reason, in the conventional magneto-optical disk device 1, it is necessary to reduce the moving range of the objective lens in order to secure the modulation magnetic field of the specified value with the small-sized modulation coil 11, so that at the time of seek. However, there is a problem that it is difficult to shorten the time required for the seek because it is necessary to perform the alignment with high accuracy by the linear actuator 7 as much as the range of fine alignment by the objective lens is reduced. Further, it is necessary to drive not only the objective lens but also the linear actuator 7 for tracking control, and it is difficult to increase the rotation speed of the spectroscopic magnetic disk 2 to improve the recording density.

The present invention has been made in view of the above problems,
An object of the present invention is to provide a magneto-optical disk device that can shorten the time required for seeking and can increase the rotation speed of a disk-shaped recording medium.

[0019]

According to the present invention, an object lens for converging a light beam emitted from a light source onto a disk-shaped recording medium and a modulation magnetic field with respect to the converging position of the light beam are provided. A modulation coil for applying a voltage, a seek means for moving the objective lens and the modulation coil in a radial direction of the disk-shaped recording medium, and an irradiation position of a light beam formed by the objective lens as a radius of the disk-shaped recording medium. Achieved by a magneto-optical disk device including a tracking means that moves in a direction and a modulation coil moving means that moves the modulation coil in a radial direction of the disk-shaped recording medium, following the movement of an irradiation position of the light beam. To be done.

In the magneto-optical disk device of the present invention, preferably, the tracking means can be configured to move the objective lens to move the irradiation position of the light beam.

Further, in the magneto-optical disk device according to the present invention, preferably, the tracking control means receives the returning light from the disk to detect a tracking error, and the irradiation position of the light beam is based on the tracking error. And the modulation coil moving means moves the modulation coil based on the tracking error to follow the movement of the irradiation position of the light beam to move the modulation coil to the radius of the disk-shaped recording medium. It can be configured to move in the direction.

Further, the magneto-optical disk device of the present invention is
Preferably, the tracking control means receives the return light from the disc to detect a tracking error, and applies a drive current to a drive coil held in a predetermined magnetic circuit based on the tracking error. , The drive coil is moved to move the irradiation position of the light beam, and the modulation coil moving means moves the modulation coil in the radial direction of the disk-shaped recording medium according to the drive current, The modulation coil may be moved in the radial direction of the disk-shaped recording medium by following the objective lens. Further, in the magneto-optical disk device of the present invention, preferably, the modulation coil moving means can be configured to retract the modulation coil during reproduction.

[0023]

According to the above-mentioned structure, even when the objective lens and the modulation coil are moved at a high speed in the radial direction of the disk-shaped recording medium by the seek means, the driving means such as the objective lens and / or the galvano mirror is also used. Even when the beam irradiation position formed by the objective lens is moved to perform tracking control, the modulation coil moving means follows the movement of the light beam irradiation position on the disc,
By moving the modulation coil in the radial direction of the disk-shaped recording medium, the modulation magnetic field can be correctly applied to the irradiation position of the light beam.

In particular, due to the tracking error and the drive current of the drive coil for moving the objective lens or the like, the modulation coil is moved in the radial direction of the disk-shaped recording medium in accordance with the movement thereof to the irradiation position of the light beam. The modulating magnetic field can be applied correctly.

Further, by the modulation coil moving means for moving the modulation coil, the modulation coil is retracted during reproduction, so that the loading and unloading mechanism of the modulation coil can be shared.

[0026]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described in detail below with reference to the accompanying drawings. It should be noted that the examples described below are suitable specific examples of the present invention, and therefore, various technically preferable limitations are given, but the scope of the present invention particularly limits the present invention in the following description. Unless otherwise stated, these aspects are not limited.

FIG. 1 shows an embodiment of a magneto-optical disk device according to the present invention. In the figure, in the structure of the magneto-optical disk device 20, the parts denoted by the same reference numerals as those in the above-mentioned conventional example have the same structure, and therefore, duplicated description will be omitted.

In FIG. 1, a magneto-optical disk device 20 is provided.
Drives a disk motor 3 using a spindle servo circuit composed of a medium rotation control means 21, thereby rotating the magneto-optical disk 2 at a predetermined rotation speed. The optical block 5 emits a light beam toward the movable portion 6, receives the return light beam emitted from the movable portion 6, and determines a tracking error and a focus error based on the reception result of the return light beam. The detection is performed and the tracking error signal and the focus error signal, which are the detection results, are output to the control unit 23. As a result, in the optical block 5, the movable portion 6
A tracking error detection system is formed together with the reflection mirror and the like formed in the above. In the magneto-optical disk device 20, the light beam irradiation position detection means 22 is formed by this tracking error detection system.

The movable unit 6 moves the objective lens 24 and the modulation coil 11 in the radial direction of the magneto-optical disk device by the linear actuator 7, and accordingly, in the magneto-optical disk device 20, the linear unit 7 is controlled by the control unit 23. A drive circuit for driving the actuator 7 and the linear actuator 7 form a drive means 25 for the movable portion, and the drive means 25 and the control portion 23 form the objective lens 24 and the modulation coil 11 in the radial direction of the magneto-optical disk 2.
Will seek.

In the objective lens 24, the biaxial actuator 1 is held by the biaxial actuator 10 (see FIG. 4) and is driven by the drive circuit controlled by the controller 23.
When 0 is driven, it moves vertically and horizontally based on the focus error signal and the tracking error signal,
As a result, the magneto-optical disk device 20 is adapted to perform tracking control and focus control. Thus, in the magneto-optical disk device 20, the driving circuit 26 for the objective lens is formed by the driving circuit for the biaxial actuator 10 and the biaxial actuator 10, and the driving means 26, the control section 23 and the irradiation position detecting means. 22 will form the tracking means.

Further, in the objective lens 24, the drive circuit of the biaxial actuator 10 detects the drive current of the biaxial actuator moving in the radial direction of the magneto-optical disk 2, and the detection result is output to the control unit 23. To be done. As a result, in the magneto-optical disk device 20,
The driving circuit of the biaxial actuator 10 forms a lens position detecting means for the objective lens 24.

Here, the modulation coil 11 is held by a predetermined holding mechanism as shown in FIG.
At the same time, it moves in the radial direction of the magneto-optical disk 2.

That is, in this holding mechanism, a gimbal 27 is formed by elongating a member having a spring property toward the tip, and the gimbal 27 is partially cut and raised near the base thereof and bent like a spring. The end of the processed and bent spring-shaped portion 28 is fixed to the yoke 29. Further, in this holding mechanism, the yoke 29 is fixed to the holding member 8, and the modulation coil 11 is attached to the tip of the gimbal 12.
Is fixed. As a result, this holding mechanism presses the magneto-optical disk 2 and when the objective lens 24 is located at the center of movement, the modulation coil 1
The modulation coil 11 is held facing the objective lens 24 so that the center of the modulation magnetic field formed by 1 is at this light beam irradiation position.

Further, in this holding mechanism, a coil 30 is mounted at the base of the gimbal 27, and the control unit 23
This coil 3 is driven by a predetermined drive circuit controlled by
A drive current is applied to 0. further,
In the yoke 29, a magnet 31 is held so as to face the coil 30, and a magnetic circuit is formed by a member (not shown) and the magnet 31 so as to form a magnetic field across the coil 30 with the coil 30 interposed therebetween. Are formed. As a result, in this holding mechanism, the coil 30
The modulation coil 11 attached to the tip of the magneto-optical disk 2 can be moved in the radial direction of the magneto-optical disk 2 in accordance with the drive current.

Thus, in the magneto-optical disk device 20, the magnetic circuit formed by the yoke 29 and the magnet 31, the coil 30, and the drive circuit for supplying the drive current to the coil 30 are the modulation coil 11. The drive means 33 for changing the position of the modulation magnetic field to be formed is formed. Further, the drive circuit for driving the coil 30 detects the drive current of the coil 30, and the control unit 23 can detect the movement amount of the modulation coil 11 based on the detection result. As a result, this drive circuit forms the magnetic field position detecting means 34 for detecting the position of the modulating magnetic field in this embodiment.

The control unit 23 is formed of, for example, an arithmetic processing unit, and controls the overall operation of the magneto-optical disk device 20 by executing a predetermined processing procedure. That is, the control unit 2
3 detects the displacement amount from the moving center of the objective lens 24 based on the drive current of the biaxial actuator 10,
A drive current is supplied to the coil 30 based on the detection result, and the modulation coil 11 is moved so as to follow the movement of the objective lens 24. Then, the control unit 23 controls the coil 3
The modulation coil 11 is moved while monitoring the current value of 0, whereby the modulation coil 11 is moved following the movement of the objective lens 24 so that the modulation magnetic field can be applied to the light beam irradiation position with certainty. Let

As a result, in the magneto-optical disk device 20, even if the objective lens is displaced and the light beam irradiation position is displaced, the position of the modulation magnetic field can be displaced by following this displacement. Therefore, since the positioning of the movable portion 6 can be roughened, the movable portion 6 can be moved at a high speed to shorten the time required for seek, and the rotation speed of the magneto-optical disk 2 can be increased. The recording density can be improved.

Thus, in this embodiment, the drive means 33, the modulation coil holding mechanism such as the coil 30, and the magnetic field position detection means, together with the control section 23, follow the objective lens and move the modulation coil. The coil moving means will be formed.

According to the magneto-optical disk device thus constructed, the light beam emitted from the optical block 5 is
After being bent toward the information recording surface of the magneto-optical disk 2 by the reflecting mirror 9 of the movable portion 6, it is converged on the information recording surface by the objective lens 24. At the irradiation position of the light beam, a predetermined modulation magnetic field is applied by the modulation coil 11 at the time of recording, whereby the polarity of the modulation magnetic field is applied to the irradiation position of the light beam intermittently irradiated by the thermomagnetic recording method. A pit corresponding to is formed and an information signal is recorded.

When information is recorded in this way, the magneto-optical disk device 20 previously executes the processing procedure shown in FIG. 3 to record information on the target track. That is, in the magneto-optical disk device 20, the process proceeds from step SP1 to step SP2, and when a predetermined access command is input, the light amount of the light beam is kept at the light amount at the time of reproduction, and the process proceeds to step SP3. Move.

Here, in the magneto-optical disk device 20, the control unit 23 controls the drive circuit to drive the linear actuator 7 to move the movable unit 6 almost to the target track. As a result, the magneto-optical disk device 20 roughly positions the irradiation position of the light beam on the target track in a short time, and then proceeds to step SP4 to move the objective lens 24 according to the tracking error detected by the optical block 5. To move the light beam irradiation position to the target track.

Subsequently, the magneto-optical disk device 20 moves to step SP5, and the control unit 23 is driven by the drive current of the objective lens 24 detected by the drive circuit of the biaxial actuator.
Measure the amount of movement of the objective lens 24 with the following step SP
At 6, the modulation coil 11 is moved by the amount of this movement, and the center of the modulation magnetic field is moved to the light beam irradiation position. When the modulation magnetic field and the light beam irradiation position are thus positioned, the magneto-optical disk device 20 completes the seek in the following step SP7, and starts writing the data input from the host computer or the like in the following step SP8. , And the processing procedure is completed by moving to step SP9.

As a result, in the magneto-optical disk device 20, the seek can be completed in a shorter time than in the conventional case, and the modulation coil 11 can be downsized.
It is possible to effectively avoid an increase in power consumption and also reduce heat generation. Furthermore, since the drive current required for driving the modulation coil 11 can be held at a small current, even when the data transfer rate is set to a high speed,
It is possible to reliably switch the polarity of the modulation magnetic field. Thereby, the recording density can be improved. Further, also at the time of assembly, the positioning accuracy of the modulation coil can be reduced, and the time required for assembly can be shortened accordingly.

In recording the data in this way, in the magneto-optical disk device 20, the objective lens 24 is moved according to the tracking error detected by the optical block 5 to perform tracking control. Further, the drive current required for the movement of the objective lens 24 is detected, the modulation coil 11 is moved according to this current, and when the light beam irradiation position is changed by the tracking control by this, the changed light beam irradiation position is set. The position of the modulating magnetic field is changed so that the modulating magnetic field is applied. As a result, in the magneto-optical disk device 20, even if the magneto-optical disk 2 is eccentric, the position of the light beam irradiation position and the modulation magnetic field can be corrected by following this eccentricity, and the magneto-optical disk 2 rotates. The recording speed can be increased by increasing the speed.

That is, in a magneto-optical disk in which a perpendicularly magnetized film is formed on a resinous substrate, the amount of eccentricity is large, so that it is difficult to select a high rotation speed in the conventional magneto-optical disk device. is there. On the other hand, according to the magneto-optical disk device 20 of this embodiment, even if this type of magneto-optical disk is used, the recording density can be improved by rotationally driving at a high speed.

In the above embodiment, the case where the laser light source is formed separately from the optical component such as the objective lens has been described, but the present invention is not limited to this, and the laser light source is an optical component such as the objective lens. The present invention can be widely applied to the case where the optical pickup is held integrally with the optical pickup.

Further, in the above-mentioned embodiment, the case where the present invention is applied to the magneto-optical disk device which moves the light beam irradiation position by using the linear actuator and the biaxial actuator has been described, but the present invention is not limited to this. Instead, it can be widely applied to a magneto-optical disk device that moves the light beam irradiation position by using a galvano mirror or the like.

Further, in the above-mentioned embodiment, the case where the desired information is recorded by overwriting is described, but the present invention is not limited to this, and can be widely applied to the case of erasing with an erase head or the like. You can

Further, in the above-described embodiment, the case where the modulation coil is simply moved in the radial direction of the magneto-optical disk by the holding mechanism of the modulation coil 11 has been described, but the present invention is not limited to this, and at the time of reproduction or the like. The modulation coil may be retracted by using this moving mechanism.

Further, in the above-mentioned embodiment, the case where the modulation coil previously positioned at the light beam irradiation position is moved following the movement of the objective lens has been described, but the present invention is not limited to this, and for example, light When the modulation coil is attached offset from the beam irradiation position, the modulation coil may be moved following the movement of the objective lens so that the offset is also corrected. By doing so, the assembly accuracy can be further reduced.

Further, in the above-mentioned embodiments, the case where the drive current of the biaxial actuator is detected to detect the position of the objective lens 24 has been described, but the present invention is not limited to this, and the point is that the objective lens 24 is essential. The modulation coil 11 may be moved in accordance with the movement of, for example, when the modulation coil 11 is moved based on a tracking error, or when the moving mechanism of the objective lens and the modulation coil 11 is partially or wholly shared. It can be widely applied to etc.

[0052]

As described above, according to the magneto-optical disk apparatus of the present invention, it is possible to shorten the time required for seek and increase the rotational speed of the magneto-optical disk.

[Brief description of drawings]

FIG. 1 is a conceptual diagram showing a configuration of an embodiment of a magneto-optical disk device according to the present invention.

FIG. 2 is a perspective view showing a modulation coil holding mechanism of FIG.

FIG. 3 is a flowchart for explaining the operation of the magneto-optical disk device of FIG.

FIG. 4 is a perspective view showing a conventional magneto-optical disk device.

5 is a perspective view showing the modulation coil holding mechanism of FIG. 4. FIG.

[Explanation of symbols]

 1, 20 Magneto-optical disk device 2 Magneto-optical disk 3 Disk motor 5 Optical block 6 Moving part 7 Linear actuator 8 Holding member 11 Modulation coil 12,27 Gimbal 23 Control part 30 Coil 31 Magnet

Claims (5)

[Claims] 1. An objective lens for converging a light beam emitted from a light source onto a disk-shaped recording medium, a modulation coil for applying a modulation magnetic field to the converging position of the light beam, and the objective lens and the modulation coil. Seek means for moving in the radial direction of the disk-shaped recording medium; tracking means for moving the irradiation position of the light beam formed by the objective lens in the radial direction of the disk-shaped recording medium; and A magneto-optical disk device comprising: a modulation coil moving unit that moves the modulation coil in a radial direction of the disk-shaped recording medium following the movement. 2. The magneto-optical disk device according to claim 1, wherein the tracking means is configured to move the objective lens to move the irradiation position of the light beam. 3. The tracking control means receives the returning light from the disc to detect a tracking error,
The irradiation position of the light beam is moved based on the tracking error, and the modulation coil moving unit follows the movement of the irradiation position of the light beam by moving the modulation coil based on the tracking error. 2. The magneto-optical disk device according to claim 1, wherein the modulation coil is configured to move in the radial direction of the disk-shaped recording medium. 4. The tracking control means receives a return light from the disk to detect a tracking error, and applies a drive current to a drive coil held in a predetermined magnetic circuit based on the tracking error. By moving the drive coil to move the irradiation position of the light beam, the modulation coil moving means moves the modulation coil in the radial direction of the disk-shaped recording medium according to the drive current. The magneto-optical disk device according to claim 3, wherein the modulation coil is configured to move in the radial direction of the disk-shaped recording medium following the objective lens. 5. The magneto-optical disk device according to claim 1, wherein the modulation coil moving means is configured to retract the modulation coil during reproduction.