JPH05314573A - Magneto-optical disk device - Google Patents

Abstract

(57) [Summary] (Correction) [Purpose] A compatible magneto-optical disk device can be made smaller and thinner, the retracting mechanism is simple, the number of parts can be reduced, and the cost can be reduced. [Structure] The magnetic modulation type and the light modulation type bias magnetic field generators A and B are configured to integrally operate with an objective lens driving device, and a part of a magnetic circuit yoke of an optical head for driving an objective lens is an objective lens In the former case, the magnetic field generator was attached to the flying slider 2, and the slider 2 was levitationally supported within the cartridge opening of the recording medium by relative motion with the recording medium. In the latter case, the core member 1 is composed of an electromagnet and a substantially ring-shaped core member 1 having a gap portion in one part. It is located on both sides, and on the optical head side, it extends to the yoke and contacts.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an objective lens driving device for controlling movement of an objective lens of an optical head in a seek direction, a tracking direction, and a focusing direction with respect to a disc-shaped magneto-optical recording medium, and the above objective. For the minute area where the laser light from the lens forms a light spot,
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.

[0002]

2. Description of the Related Art In this type of magneto-optical disk device, a constant magnetic field is applied to a recording area of a magneto-optical recording medium by a bias magnetic field generator, and laser light modulated by recording information is applied from the optical head to the recording area. For example,
First generation ISO such as 3.5 inch magneto-optical disk
Also for a magneto-optical recording medium for recording by an optical modulation method, which is based on (hereinafter referred to as ISO), 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 so that information can be recorded / reproduced even with respect to a magneto-optical recording medium which is recorded by a so-called magnetic field modulation method, which is given from the magnetic field generator to the recording area.

Therefore, in the above magneto-optical disk device,
As shown in FIGS. 7 and 8, a structure that selectively uses two types of bias magnetic field generators is adopted. Here, of the two types of bias magnetic field generators, the one indicated by reference numeral 102 applies a constant magnetic field to a magneto-optical recording medium for optical modulation recording corresponding to ISO, and based on recording information from the optical head side. A fixed bias magnetic field generator used when recording is performed, and a device denoted by reference numeral 101 is a magnetic field modulation device having a magnetic field generation unit (not shown) with a small number of turns for rapidly modulating the magnetic field. It is a bias magnetic field generator for a recording system. The bias magnetic field generating device 101 needs to keep a space of several μm from the disk surface of the magneto-optical recording medium in order to obtain a required magnetic field strength in a limited minute area, and a control mechanism therefor (not shown). ) Is provided.

A laser beam emitted from a light source (not shown) of a fixed optical system is reflected by, for example, a bending mirror and condensed by an objective lens 103, and is recorded on the recording layer of the magneto-optical recording medium. To form a light spot. The objective lens 103 is supported by a lens holder 103A, and the lens holder 103A is an elastic support mechanism 103 such as a leaf spring.
It is attached to the objective lens driving device 105 via B. Then, the objective lens 103 is focused on the recording medium by controlling the movement of the lens holder 103A, and the objective lens driving device 10 is also provided.
A seek operation and tracking are performed by the movement control of 5.

A bias magnetic field generator 10 for magnetic field modulation recording is provided in a minute area including the light spot and its periphery.
A constant magnetic field is applied from the magnetic field generation unit (magnetic head) configured in No. 1 and information is written on the recording medium in accordance with the polarity of this magnetic field. The bias magnetic field generator 101 is fixed to the second drive mechanism 104.
The objective lens driving device 105 and the driving mechanism 104 are independently controlled to move in the radial direction of the disk.

Further, when the bias magnetic field generator 101 is used in the modulation magnetic field recording method as described above, the fixed bias magnetic field generator 102 is moved in the direction of arrow a by an appropriate driving means (not shown). It has been saved (see FIG. 8). Therefore, the bias magnetic field generator 101 is
It becomes possible to move the entire recording area of the magneto-optical disk (magneto-optical recording medium), and the fixed bias magnetic field generator 102 does not interfere with the bias magnetic field generator 101 and its driving mechanism.

[0007]

[Problems to be Solved by the Invention]
In addition, in the conventional example shown in FIG. 8, two types of bias magnetic field generators are prepared in order to correspond to the ISO optical modulation recording magneto-optical disk and the magnetic field modulation recording magneto-optical disk. Since the fixed bias magnetic field generator 102 is configured to retract above the bias magnetic field generator 101 when the bias magnetic field generator 101 is operating, it is possible to reduce the size, simplification and thinness of the device. Is disadvantageous. In particular, the means for detecting the relative position between the objective lens driving device and each bias magnetic field generating device, and the mechanism such as the alignment thereof are complicated, and the structure is inevitably complicated.

Further, in the optical modulation recording, in order to bring the fixed bias magnetic field generator 102 close to the vicinity of the disk surface, it is necessary to retract or move the drive unit of the bias magnetic field generator 101 in the radial direction of the recording medium. Therefore, a considerable expansion dimension is required in the depth direction of the device, and a mechanism for retreating or moving is required, and the device is inevitably complicated.

Further, since the bias magnetic field generator 101 for magnetic field modulation gives priority to frequency characteristics, the generated magnetic field is originally small. Therefore, as shown in FIG. 6, the magnetic force for driving the objective lens of the optical head is as follows. There is a possibility that the C / N of a recording signal may deteriorate during magnetic field modulation recording due to the influence of a stray magnetic field of a circuit or the like.

[0010]

SUMMARY OF THE INVENTION The present invention has been made based on the above circumstances, and records information on both a first-generation ISO compatible optical modulation recording magneto-optical disk and a magnetic field modulation recording magneto-optical disk. Enabled to play 2
In a magneto-optical disk device that is compatible with various types of recording methods, the device can be made smaller and thinner, and the mechanism for the retracting operation can be simplified to reduce the number of parts in the configuration and reduce the cost. An object of the present invention is to provide a magneto-optical disk device capable of realizing down.

[0011]

Therefore, according to the present invention,
An objective lens driving device that controls the movement of the objective lens of the optical head in the seek direction, the tracking direction, and the focusing direction with respect to the disk-shaped magneto-optical recording medium, and a minute laser beam from the objective lens that forms a light spot. In a magneto-optical disk device equipped with a first bias magnetic field generator for applying a magnetic modulation recording bias magnetic field and a second bias magnetic field generator for applying an optical modulation bias magnetic field to a region, The bias magnetic field generator is configured to operate integrally with the objective lens driving device, and a part of a yoke forming a magnetic circuit for driving the objective lens of the optical head circulates the objective lens, The first bias magnetic field generating device is arranged substantially parallel to the disk surface of the recording medium, and the magnetic field generating part is attached to the flying slider. With, in the cartridge opening of the recording medium, the relative movement between the recording medium, through a predetermined distance from the disk surface, and has a configuration which is supported so as to float the slider, and the second
The bias magnetic field generator of is composed of an electromagnet and a substantially ring-shaped core member having a gap portion in a part thereof, and the core member is formed so that a minute region of the light spot corresponds to the gap portion. Both ends are located on both sides of the recording medium, and on the optical head side, they extend to and come into contact with the yoke.

[0012]

As a result, the entire apparatus can be made smaller and thinner,
Further, the number of parts of the retracting mechanism can be reduced and the cost can be reduced, and moreover, for the magneto-optical recording medium for optical modulation recording,
Information can be recorded / reproduced on / from a magneto-optical recording medium for magnetic field modulation recording, and versatility as a magneto-optical disk device can be exhibited.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be specifically described below with reference to FIGS. FIG. 1 shows a magneto-optical disk apparatus according to the present invention. Here, a magnetic field modulation type recording bias magnetic field generating apparatus A is used as the first bias magnetic field generating apparatus, and a second bias magnetic field generating apparatus is used. An optical modulation type recording bias magnetic field generator B for recording is equipped as an apparatus.

As is well known, in the bias magnetic field generator A, the levitation slider 2 having a magnetic head as a bias magnetic field generator is mounted on a supporting member 2B via a supporting spring 2A as a load beam. And the support member 2B is pivotally supported by a carriage 10 having an optical system mounted thereon via a rotary support shaft 12. The carriage 10 uses a linear motor composed of a magnetic circuit 9 and a coil (which is mounted on the carriage 10) 11 to drive a magneto-optical recording medium (hereinafter
It is configured to be movable along a guide rail 8 extending in a radial direction (referred to as a magneto-optical disk) 40 (radial direction of the disk). The magneto-optical disk 40 is provided on the tip side of the guide rail 8.
However, it is designed to be loaded into the cassette holder 20 which is the loading portion of the apparatus body while being housed in the disc cassette 30.

When loading or unloading the disk cassette 30 into or from the loading section, the magnetic head of the bias magnetic field generating apparatus A is repelled from the surface of the magneto-optical disk 40 so as to be repelled by the apparatus body. As a mechanism, a solenoid drive mechanism 53 having a retract lever 50 is equipped. Then, the retractable lever 50 is provided with a roll-shaped engagement contact portion 7 provided at the rear end of the support member 2B.
Can be pushed down.

The bias magnetic field generator B comprises a core member 1 mounted on the carriage 10 and a coil 4 wound around the core member 1, and the core member 1 has a substantially ring shape having a gap portion in part. Both ends of the gap are formed so that a minute area of a light spot formed on the disk surface of the magneto-optical disk through an optical system (described later) mounted on the carriage 10 corresponds to the gap portion. The parts 1a and 1b are located on both sides of the magneto-optical disk 40. In this embodiment, the optical system is equipped with an objective lens 6, which is mounted on a lens holder 6B which moves vertically and horizontally by a magnetic circuit composed of a coil 6A (6A ') and yokes 6C and 6D. By applying a voltage to the coil 6A (6A '), the objective lens 6 is moved up and down to perform focusing and tracking control. In addition, in this embodiment, the yoke 6D shown in FIG.
As shown in (B), the objective lens 6 is rotated. Therefore, similarly, as shown in FIG. 2B, a closed magnetic path can be formed by a yoke that constitutes a magnetic circuit for driving the objective lens of the optical head, and a magnetic shield effect can be exhibited. When recording, stray magnetic fields are avoided from adversely affecting the recording magnetic fields.

The core member 1 is composed of at least two members (in this embodiment, a total of three members, that is, upper and lower two members 1X, 1Y and one relay core member 1Z). One member 1X is a movable core member that forms the one end 1a of the gap portion on the side where the first bias magnetic field generator is arranged. In addition, the movable core member 1
The mechanism for loading / unloading X onto / from the disk surface is the carriage 1 with the rotary support shaft 12 as a common shaft.
0 is composed of an upper core support member 3 pivotally supported,
The movable core member 1X is attached to this.
The upper core supporting member 3 is provided with an engaging portion 3a, and when the cassette holder 20 is lifted from the loading portion when the disc cassette 30 is taken out, the protrusion portion 20a provided on the cassette holder 20 is engaged with the engaging portion 3a. The movable core member is configured to be able to be flipped up by engaging with the joint portion 3a. Further, in this embodiment, the coil 4 is
Is wound around the upper core member 1X, and the lower core member 1Y
The relay core member 1Z and the relay core member 1Z are fixedly supported by the carriage 10 in a state of being connected to each other, and when the one end portion 1a of the movable core member 1X is close to the recording surface of the magneto-optical disc 40, the relay is performed. The upper end 1c of the core member 1Z and the base end 1d of the movable core member 1X are in contact with each other,
As a whole, a magnetically continuous C-shaped (substantially ring-shaped core member 1 having a gap) core member 1 is formed. Further, the lower core member 1Y has a thin plate 1W made of a material having a high magnetic flux density.
Is attached, extends to the yoke 6D, and is in elastic contact with it. Therefore, a part of the yoke 6D forming the magnetic circuit for driving the objective lens of the optical head can be used as a part of the core member 1, so that the magnetic path resistance is reduced when recording is performed by the light modulation method. The driving efficiency can be improved.

Further, the apparatus body is equipped with a disc type detection sensor (detection means) 51 together with a disc cassette loading confirmation sensor (detection means) 52, which is arranged in the cassette holder 20. The latter sensor also functions as a write protect sensor. The information detected by these sensors is provided to the control circuit 54, and the control circuit 54 drives the drive circuit 55 for driving the solenoid drive mechanism 53.
Then, a control signal is issued. The optical signal in the optical system is supplied to the control circuit 54 through the detection circuit 56, is judged, and generates the required control signal. As a result, necessary recording and reproducing operations are performed (various mechanisms therefor are not shown).

Next, the corresponding operation of the bias magnetic field generators A and B according to the type of the disc loaded in the loading section will be described with reference to FIGS. Before the disc cassette 30 is loaded into the cassette holder 20 (see FIG. 3), the retraction lever 50 of the solenoid drive mechanism 53 is lowered, so that the support member 2B is centered on the rotation support shaft 12. To the slider 2, that is,
The magnetic head of the first bias magnetic field generator is retracted upward, and the upper core support member 3 has its engaging portion 3a engaged with the protruding portion 20a of the cassette holder 20 to move the movable core. The end 1a of the member is retracted upward.

When the cassette holder 20 descends and is set in the loading section of the apparatus main body, the sensors 51 and 52 operate, the type of the magneto-optical disk 40 in the disk cassette 30 and the loading of the disk cassette. It is detected whether or not the state is write-protected, and a required signal is sent to the control circuit 54. At the same time, the magneto-optical disk 4
Zero is rotationally driven by the spindle motor 80. The carriage 10 of the objective lens driving device is sought by a control signal from the control circuit 54 to irradiate the recording surface of the disk 40 with laser light through the objective lens 6, and information is reflected from the reflected light. Then, tracking and focusing control is performed to access the light spot to a required address on the disc. Recording or reproduction is performed in this state. When the cassette holder 20 descends, the core support member 3 descends while the engaging portion 3a is engaged with the protrusion 20a, and the one end 1a of the movable core member 1X is moved to the magneto-optical disk. It will be close to the recording surface of 40. At this time, as described above, the movable core member 1X forms a C-shaped (generally ring-shaped with a gap) core as a whole by contacting the relay core member 1Z. Regulated.

In this case, if it is determined by the function of the sensor 51 that the magneto-optical disk 40 is for magnetic field modulation, a signal from the control circuit 54 is sent to the drive circuit 55 as shown in FIG. The solenoid drive mechanism 53 is driven to raise the retracting lever 50, and the supporting member 2
B is returned from the retracted position to the operating position, and the slider 2 is floated above the recording surface of the magneto-optical disk 40 while maintaining a predetermined gap. As a result, recording and reproduction are performed by the first bias magnetic field generator A.

If the sensor 51 determines that the magneto-optical disk 40 is for optical modulation, the retracting lever 50 is left as it is as shown in FIG. Since 2B is left in the retracted position, as shown in FIG. 5, only the core member 1 is in the operating state and recording by the second bias magnetic field generator B is performed.
Playback is performed.

In such a configuration, since the bias magnetic field generator of any of the bias magnetic field generators moves together with the seek operation of the carriage 10 and the control of the tracking direction, the above magnetic field with respect to the light spot is moved. Position detection and adjustment of the generation unit are not necessary at all, a device therefor is omitted, and the structure can be simplified. Further, the magnetic field generation unit for light modulation is also downsized, and the space retracted upward is significantly reduced, and the device as a whole can be made thinner.

In the bias magnetic field generator B for optical modulation, it is sufficient even if the magnetic radiation surface of the core member 1 is set larger than the surface wobbling dimension of the disk and apart from the recording surface of the disk. Since a magnetic field can be applied, it is not necessary to use a floating type head as in the case of the magnetic head for magnetic field modulation. Further, since the bias magnetic field generator B can be loaded / unloaded regardless of the position and state of the flying slider 2 (magnetic head), an emergency such as mounting a disk for optical modulation or power failure / failure is required. At this time, the structure of the retracting mechanism of the magnetic head for magnetic field modulation can be simplified. Further, in the above embodiment, the mechanism (upper core support member 3) for loading / unloading the movable core member with respect to the disc surface may be linked with the loading / unloading mechanism of the disc cassette.

Further, the winding position of the coil 4 on the core member 1 is not limited to one, and it may be mounted on the upper core member, the relay core or the like. Further, the movable part of the core member 1 need not be limited to the upper core member,
The lower core member may also be movable. Further, the thin plate attached to the lower core member is a member having a high magnetic flux density / low coercive force, in addition to iron or its alloy, for example, a thin plate of a resin material provided with a film of the above material, and has magnetism. A thin plate made of a polymer material may be used. Furthermore, if the conditions are allowed, the shape may not be a thin plate shape, but may be a coil spring shape, for example. In this embodiment, a part of the core supporting member 3 for holding the core member is brought into contact with the cassette holder to enable the loading / unloading operation of the core member. However, a magnetic head for magnetic field modulation. Similar to the load / unload mechanism of (1), a mechanism that is driven asynchronously with other mechanism may be provided to realize this operation.

[0026]

As described above, the magneto-optical disk apparatus of the present invention is used for magnetic field modulation recording of a 3.5-inch magneto-optical disk for magneto-optical recording for optical modulation recording compatible with the first generation ISO. When information is recorded / reproduced on / from a magneto-optical disk, compatibility as a magneto-optical disk device can be ensured, and when a magnetic field modulation type bias magnetic field generator for recording is operating. It is not necessary to retract the optical modulation type bias magnetic field generator for recording, the retracting mechanism can be simplified, and since both the bias magnetic field generators are interlocked with the objective lens driving device, position detection is possible. Means, position adjusting means, etc. can be omitted, the number of parts can be reduced as a whole, and a magneto-optical disk capable of supporting magneto-optical disks of two kinds of recording methods at low cost. It is possible to provide a click device.

[Brief description of drawings]

FIG. 1 is a perspective view of an embodiment of the present invention.

FIG. 2A is a perspective view showing a position related to a cassette holder in the above embodiment, and FIG. 2B is a perspective view showing details of an objective lens driving device.

FIG. 3 is a side view showing a mode of use of the above embodiment.

FIG. 4 is a side view showing a mode of use of the above embodiment.

FIG. 5 is likewise a side view showing a mode of use of the above embodiment.

FIG. 6 is a graph showing the magnitude of a stray magnetic field during magnetic field modulation according to the present invention.

FIG. 7 is a perspective view of a conventional example.

FIG. 8 is a perspective view showing a usage pattern of a conventional example in (a) and (b).

[Explanation of symbols]

 A Bias magnetic field generator for magnetic modulation B Bias magnetic field generator for optical modulation 1 Core member (magnetic field generation part) 1a, 1b End part 1X Upper core member 1Y Lower core member 1Z Relay core member 1W Thin plate 3 Core support member 4 Coil 2 Floating slider (magnetic head) 2A Leaf spring 2B Support member 6 Objective lens 6A Coil 6B Lens holder 6C, 6D Magnetic lens yoke for driving objective lens 7 Engagement contact part 10 Carriage 12 Rotating spindle 20 Cassette holder 30 Disc Cassette 40 magneto-optical disk

Claims (5)

[Claims] 1. A disk-shaped magneto-optical recording medium,
A bias magnetic field for magnetic modulation recording is applied to the objective lens driving device that controls the movement of the objective lens of the optical head in the seek direction, the tracking direction, and the focusing direction, and the minute area where the laser light from the objective lens forms a light spot. In a magneto-optical disk device equipped with a first bias magnetic field generating device for applying a bias magnetic field and a second bias magnetic field generating device for applying a bias magnetic field for optical modulation, the both bias magnetic field generating devices are the objective lens driving device. And a part of a yoke forming a magnetic circuit for driving the objective lens of the optical head orbits the objective lens and is arranged substantially parallel to the disk surface of the recording medium. In the first bias magnetic field generator, the magnetic field generator is attached to the flying slider to open the cartridge of the recording medium. In section, the relative movement between the recording medium, through a predetermined distance from the disk surface, and has a configuration which is supported so as to float the slider,
Further, the second bias magnetic field generator is composed of an electromagnet and a substantially ring-shaped core member having a gap portion in part, and the core member corresponds to the gap portion with a minute region of the light spot. Thus, the magneto-optical disk device is characterized in that both ends thereof are located on both sides of the recording medium, and the optical head side extends to and contacts the yoke. 2. The core member is composed of at least two members, and one member is a movable core member that constitutes one end of the gap portion on the side where the first bias magnetic field generator is arranged. And a mechanism for detecting whether the recording medium is mounted in the cassette and a mechanism for loading / unloading the movable core member to / from the disk surface in response to a signal from the detecting unit. The magneto-optical disk device according to claim 1. 3. The movable core member, wherein the core member is composed of at least two members, and one member is one end of the gap portion on the side where the first bias magnetic field generator is arranged. In addition, a mechanism for loading / unloading the movable core member to / from the disk surface is provided, and the loading / unloading mechanism is configured to interlock with the loading / unloading mechanism of the cassette of the recording medium. The magneto-optical disk device according to claim 1. 4. A thin plate made of a material having a high magnetic flux density is installed at the tip of the core member located on the optical head side,
The magneto-optical disk device according to claim 1, wherein the yoke is elastically contacted. 5. The movable core member, wherein the core member is composed of at least two or more members, and one member constitutes one end of the gap portion on the side where the first bias magnetic field generator is arranged. In addition, a mechanism for independently loading / unloading the movable core member and the floating slider to / from the disk surface is provided, and detection means for detecting the type of the recording medium and cassette loading of the recording medium are also provided. And a drive means for driving the load / unload mechanism so as to retract the floating slider from the disk surface based on the determination when the type of the recording medium is detected. The magneto-optical disk device according to claim 1.