JP2956808B2 - Magneto-optical disk drive - Google Patents

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 the movement of an objective lens of an optical head in a seek direction, a tracking direction, and a focusing direction with respect to a disk-shaped magneto-optical recording medium, and the objective object. The laser light from the lens forms a light spot on a small area.
The present invention relates to a magneto-optical disk device including first and second bias magnetic field generators for recording information by different modulation methods.

[0002]

2. Description of the Related Art A magneto-optical disk drive of this type applies a constant magnetic field to a recording area of a magneto-optical recording medium by a bias magnetic field generator and supplies laser light modulated by recording information from an optical head to the recording area. For example,
First generation ISO such as 3.5 inch magneto-optical disk
In addition, a constant laser beam is applied from an optical head to a recording area, and a magnetic field modulated by recording information is applied to a magneto-optical recording medium that performs recording by an optical modulation method based on the optical modulation method (hereinafter referred to as ISO). It is necessary to ensure compatibility so that information can be recorded / reproduced with respect to a magneto-optical recording medium which is provided from the magnetic field generator to the above-mentioned recording area and is recorded by a so-called magnetic field modulation method.

For this reason, in the magneto-optical disk drive,
As shown in FIGS. 9 and 10, a structure in which two types of bias magnetic field generators are selectively used is employed. Here, of the two types of bias magnetic field generators,
Reference numeral 102 denotes a fixed bias magnetic field generator used when a constant magnetic field is applied to a magneto-optical recording medium for optical modulation recording corresponding to ISO and recording is performed based on recording information from the optical head side. The reference numeral 101 denotes a bias magnetic field generator for a magnetic field modulation recording system having a magnetic field generator (not shown) having a small number of turns for modulating a magnetic field at high speed. The bias magnetic field generator 101 needs to maintain an interval of about 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 (not shown) for that purpose. ).

[0004] Laser light emitted from a light source (not shown) of the fixed optical system is reflected by, for example, a bending mirror and condensed by an objective lens 103 to form a laser beam 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.
B is attached to the objective lens driving device 105 via B. Then, by controlling the movement of the lens holder 103A, the objective lens 103 is focused on the recording medium.
The seek operation and tracking are performed by the movement control of No. 5.

In a minute area including the light spot and its periphery, a bias magnetic field generator 10 for magnetic field modulation recording is provided.
A constant magnetic field is applied from the magnetic field generator (magnetic head) configured as described above, and information is written on the recording medium in accordance with the polarity of the magnetic field. The bias magnetic field generator 101 is fixed to a second drive mechanism 104.
In addition, the objective lens driving device 105 and the driving mechanism 104 are independently controlled to move in the radial direction of the disk.

When the bias magnetic field generator 101 is used in the modulation magnetic field recording system, the fixed bias magnetic field generator 102 is driven by an appropriate driving means (not shown) in the direction of arrow a. It has been evacuated (see FIG. 10). For this reason, the bias magnetic field generator 101
The entire recording area of the magneto-optical disk (magneto-optical recording medium) can be moved, and the fixed bias magnetic field generator 102 does not interfere with the bias magnetic field generator 101 and its driving mechanism.

[0007]

As described above, FIG.
Also, in the conventional example shown in FIG. 10, two types of bias magnetic field generators are prepared in order to support the magneto-optical disk for optical modulation recording and the magneto-optical disk for magnetic field modulation recording of ISO. When the bias magnetic field generator 101 is operating, the fixed bias magnetic field generator 102 is configured to retreat above the bias magnetic field generator 101. Disadvantageous. In particular, the means for detecting the relative position between the objective lens driving device and each of the bias magnetic field generating devices, and the mechanism for aligning the devices are complicated, and structural complexity is inevitable.

[0008]

SUMMARY OF THE INVENTION The present invention has been made on the basis of the above circumstances, and records information on a first-generation ISO-compliant optical modulation recording magneto-optical disk and a magnetic field modulation recording magneto-optical disk. Playback can be performed 2
In a magneto-optical disk device compatible with various types of recording systems, the device can be reduced in size and thickness, and the mechanism for the evacuation operation is simplified, so that the number of components in the configuration is reduced, and the cost is reduced. It is an object of the present invention to provide a magneto-optical disk drive capable of realizing down.

[0009]

Therefore, in 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 microscopic laser beam from the objective lens forms a light spot. In a magneto-optical disk device equipped with 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 a light modulation bias magnetic field to a region, The bias magnetic field generating device attaches its magnetic field generating part to a floating slider, and floats the slider through a required space with respect to the disk surface by a relative movement with the recording medium in the cartridge opening of the recording medium. The second bias magnetic field generator is provided with an electromagnet and a part thereof. The core member is located at both ends of the recording medium so that the minute area of the light spot corresponds to the gap. The two bias magnetic field generators are configured to operate integrally with the objective lens driving device.

[0010]

[Function] As a result, the entire device can be reduced in size and thickness.
Also, the number of parts of the retracting mechanism can be reduced, the cost can be reduced, and the magneto-optical recording medium for optical modulation recording can be
Information can be recorded / reproduced even on a magneto-optical recording medium for magnetic field modulation recording, and the versatility as a magneto-optical disk device can be exhibited.

[0011]

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

As is well known, the above-mentioned bias magnetic field generator A is configured such that a floating slider 2 having a magnetic head as a bias magnetic field generator is mounted on a support member 2B via a support spring 2A as a load beam. , And the support member 2B is pivotally supported via a rotation support shaft 12 on a carriage 10 on which an optical system is mounted. The carriage 10 is driven by a linear motor composed of a magnetic circuit 9 and a coil (which is mounted on the carriage 10) 11 to a magneto-optical recording medium (hereinafter, referred to as a magneto-optical recording medium).
It is configured to be able to move along a guide rail 8 extending in a radial direction (a radial direction of the disk) of a magneto-optical disk 40. The magneto-optical disk 40 is provided at the tip end of the guide rail 8.
Are loaded in a cassette holder 20 which is a loading section of the apparatus main body, in a state of being housed in the disk cassette 30.

When loading or unloading the disk cassette 30 from or to the loading section, the magnetic head of the bias magnetic field generator A is retracted from the surface of the magneto-optical disk 40 so as to be retracted. As a mechanism, a solenoid drive mechanism 53 having an evacuation lever 50 is provided. Then, a roll-shaped engagement contact portion 7 provided at the rear end of the support member 2B with the retracting lever 50 is provided.
Can be depressed.

The bias magnetic field generator B comprises an electromagnet 4 mounted on the carriage 10 and a substantially ring-shaped core member 1 having a gap in a part thereof. End portions 1a and 1b of the optical disk, via an optical system (described later) mounted on the carriage 10 so that minute regions of a light spot formed on the disk surface of the magneto-optical disk correspond to each other.
Are located on both sides of the magneto-optical disk 40. In this embodiment, the optical system is provided with an objective lens 6, which is mounted on a lens holder 6B which slides up and down by a coil 6A. The objective lens 6 is operated to perform focusing control.

The core member 1 is composed of at least two or more members (in this embodiment, three members of upper and lower two members and one relay core member), one of which is a member. And a movable core member that constitutes one end 1a of the gap on the side where the first bias magnetic field generator is disposed. The mechanism for loading / unloading the movable core member with respect to the disk surface is constituted by the upper core support member 3 pivotally supported by the carriage 10 using the rotation support shaft 12 as a common axis. The above-mentioned movable core member is attached to. The upper core support member 3 is provided with an engaging portion 3a. When the cassette holder 20 is lifted from the loading portion when the disk cassette 30 is taken out, the protrusion 20 provided on the cassette holder 20 is provided.
a is engaged with the engaging portion 3a so that the movable core member can be flipped up. In this embodiment, the coil of the electromagnet 4 is wound around the other core member (lower core member) constituting the one end 1b of the gap. The lower core member and the relay core member (indicated by reference numeral 1c) are fixedly supported by the carriage 10 while being connected to each other, and one end 1a of the movable core member is connected to the recording surface of the magneto-optical disk 40. , The upper end 1d of the relay core member 1c and the base end 1e of the movable core member come into contact with each other and are magnetically continuous as a whole in a C-shaped (substantially ring-shaped having a gap). ) Constituting the core member 1. 3 to 5, the components of the bias magnetic field generator B are hatched in order to identify the bias magnetic field generator B.

The apparatus main body is provided with a disk type detection sensor (detection means) 51 together with a disk cassette loading confirmation sensor (detection means) 52, and is disposed in the cassette holder 20. The latter sensor also has the function of a write-protection sensor. The information detected by these sensors is supplied to the control circuit 54, and the control circuit 54 outputs a drive circuit 55 for driving the solenoid drive mechanism 53.
Then, a control signal is issued. Note that the optical signal in the optical system is supplied to the control circuit 54 via the detection circuit 56, is determined, and a required control signal is generated. As a result, necessary recording and reproducing operations are performed (mechanisms for this are not shown).

Next, the corresponding operation of the bias magnetic field generators A and B according to the type of the disc mounted on the loading section will be described with reference to FIGS. Before the disk cassette 30 is loaded into the cassette holder 20 (see FIG. 3), the solenoid driving mechanism 53 has lowered its retracting lever 50, so that the support member 2B is pivoted about the rotation support shaft 12. And the slider 2, ie,
The magnetic head of the first bias magnetic field generating device is retracted upward, and the upper core support member 3 has its engaging portion 3a engaged with the projection 20a of the cassette holder 20, and has a movable core. The end 1a of the member is retracted upward.

When the cassette holder 20 is lowered and set in the loading section of the apparatus main body, the sensors 51 and 52 operate, and the type of the magneto-optical disk 40 in the disk cassette 30 and the loading of the disk cassette are performed. The state and whether or not writing is prohibited are detected, and a required signal is supplied to the control circuit 54. At the same time, the magneto-optical disk 4
0 is rotationally driven by a spindle motor 80. Then, the carriage 10 of the objective lens driving device performs a seek operation by a control signal from the control circuit 54, irradiates the recording surface of the disk 40 with laser light via the objective lens 6, and obtains information from the reflected light. Then, tracking and focusing control are performed, and the light spot is accessed at a required address on the disk. In this state, recording or reproduction is performed. When the cassette holder 20 is lowered, the core support member 3 is lowered while the engaging portion 3a is engaged with the projection 20a, and one end 1a of the movable core member is moved to the magneto-optical disk 40. Will be close to the recording surface. At this time, as described above, the movable core member contacts the relay core member 1c to form a C-shaped (generally ring-shaped) core as a whole, and regulates the gap. doing.

In this case, if it is determined by the operation of the sensor 51 that the magneto-optical disk 40 is for magnetic field modulation, a signal is sent from the control circuit 54 to the drive circuit 55 as shown in FIG. Then, the solenoid driving mechanism 53 is driven, the evacuation lever 50 is raised, and the support member 2
The slider B is returned from the retracted position to the operating position, and the slider 2 floats 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 it is determined by the operation of the sensor 51 that the magneto-optical disk 40 is for light modulation, as shown in FIG. 2B is left at the retracted position, so that only the core member 1 is in the operating state as shown in FIG.
Reproduction is performed.

In such a configuration, 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. There is no need to detect or adjust the position of the generating section, and a device therefor is omitted, and the structure can be simplified. Also, the size of the light modulation magnetic field generating unit is reduced, the space for upward retraction is greatly reduced, and the device as a whole can be made thinner.

The light modulating electromagnet 4 can apply a sufficient magnetic field even if its demagnetizing surface is set to be larger than the surface runout width of the disk and separated from the recording surface of the disk. It is not necessary to use a floating type as in the case of the magnetic head for modulating the magnetic field. The electromagnet 4
Can be loaded / unloaded irrespective of the position and state of the flying slider 2 (magnetic head), so that the magnetic head for magnetic field modulation can be loaded when an optical modulation disk is mounted, or in an emergency such as a power failure / failure. The structure of the evacuation mechanism can be simplified. In the above embodiment, a mechanism (upper core support member 3) for loading / unloading the movable core member with respect to the disk surface may be configured to be linked with the loading / unloading mechanism for the disk cassette.

In the embodiment shown in FIGS. 6 to 8, the core member 1 is provided with a spring core 1f in addition to the upper and lower two members and the relay member 1c.
Is wound around the movable core member on the side where the first bias magnetic field generator is disposed. The mechanism for loading / unloading the movable core member with respect to the disk surface is the same as in the previous embodiment, and the upper core support member 3 pivotally supported by the carriage 10 using the rotation support shaft 12 as a common axis. In particular, in this embodiment, the movable core member is attached to this via an elastic sheet member 16 having a high thermal conductivity. For the elastic sheet member 16, a material having high adhesion is selected from the viewpoint of thermal conductivity, and electrical insulation does not matter.
Therefore, silicon rubber, a material obtained by mixing mica or the like as a filler, or a copper foil can be used.

The elastic sheet member 16 is in close contact with the movable core member, and can not only enhance the heat radiation property but also manage the gap of the core member 1 by utilizing its elastic deformation. That is, in the above embodiment, the movable core member is attached to the support member 3 by the screws 17a and 17b. For example, by tightening the screw 17a, the elasticity between the movable core member and the support member 3 is increased. The sheet member 16 is bent, and as shown in FIG. 8A, the movable core member is rotated around the pivot p with respect to the relay core member 1c to narrow the gap (gap G
_S ). Further, by tightening the screw 17b, the pivot moves to q and the gap is enlarged (gap G _I as shown in FIG. 8B). If necessary, a drive circuit board 15 of a magnetic head provided on the floating slider 2 is mounted on the support member 3. In this case,
Components such as the current amplifying element 22 having high heat generation there
It is preferable to attach the support member 3 in a state where the support member 3 is in contact with the support member 3 to improve the heat radiation. In addition, as the material of the support member 3, an aluminum alloy, a magnesium alloy, or the like is preferably used in terms of both weight reduction and heat dissipation.

In this embodiment, the lower core member extends to the vicinity of an actuator for controlling the focusing of the objective lens 6, and the spring core 1
f elastically contacts the orbiting yoke corresponding to the coil 6A.

[0026]

As described above, the magneto-optical disk drive according to the present invention can be applied to a magneto-optical disk for 3.5-inch magneto-optical disks for first-generation ISO-compatible optical modulation recording. Compatibility as a magneto-optical disk device can be ensured in that information can be recorded and reproduced on the magneto-optical disk, and when the recording bias magnetic field generator of the magnetic field modulation system is operating. In addition, there is no need to retract the recording bias magnetic field generating device of the light modulation type, so that the retracting mechanism can be further simplified, and the both bias magnetic field generating devices are linked to the objective lens driving device, so that position detection can be performed. Means, a position adjusting means, etc. can be omitted, the number of parts can be reduced as a whole, and a magneto-optical disk which can be used at low cost and can cope with magneto-optical disks of two types of recording methods. It is possible to provide a click device.

[Brief description of the drawings]

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

FIG. 2 is a perspective view showing a position relative to a cassette holder in the embodiment.

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

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

FIG. 5 is a side view showing the usage of the above embodiment.

FIG. 6 is a perspective view of another embodiment of the present invention.

FIG. 7 is a side view of the embodiment.

8 (a) and 8 (b) are side views showing the manner of use of the above embodiment.

FIG. 9 is a perspective view of a conventional example.

FIGS. 10A and 10B are perspective views showing usage modes of a conventional example.

[Explanation of symbols]

 A Bias magnetic field generator for magnetic modulation 1 Core member (magnetic field generator) 1a, 1b End 1c Relay core member 1f Spring core 3 Upper movable core support member 4 Electromagnet B Bias magnetic field generator for light modulation 2 Levitated slider (magnetic Head) 2A Leaf spring 2B Support member 6 Objective lens 7 Engagement contact part 10 Carriage 12 Rotation support shaft 16 Elastic sheet member 17a, 17b Screw 20 Cassette holder 30 Disk cassette 40 Magneto-optical disk 50 Evacuation lever

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI G11B 5/02 G11B 5/02 T

Claims (9)

(57) [Claims] 1. A disk-shaped magneto-optical recording medium,
An objective lens driving device that controls the movement of the objective lens of the optical head in a seek direction, a tracking direction, and a focusing direction, and a bias magnetic field for magnetic modulation recording with respect to a minute area where a laser beam from the objective lens forms a light spot. In a magneto-optical disk device equipped with a first bias magnetic field generator for applying a bias magnetic field and a second bias magnetic field generator for applying a bias magnetic field for optical modulation, the first bias magnetic field generator has a magnetic field generator. Is attached to the floating slider, and in the cartridge opening of the recording medium, by relative movement with the recording medium, the slider is supported so as to float over a required interval with respect to the disk surface, Further, the second bias magnetic field generating device is a substantially ring-shaped core member having an electromagnet and a gap partly. The core member has both ends positioned on both sides of the recording medium so that the minute area of the light spot corresponds to the gap portion. A magneto-optical disc device configured to operate integrally with an objective lens driving device. 2. The movable core member, which comprises at least two members, one of which is one end of the gap portion on the side where the first bias magnetic field generator is disposed. 2. The apparatus according to claim 1, further comprising a mechanism for loading / unloading the movable core member with respect to a disk surface, and a detecting unit for detecting the cassette mounting of the recording medium. Magneto-optical disk drive. 3. The core member is composed of at least two or more members, one of which is a movable core member that constitutes one end of the gap on the side where the first bias magnetic field generator is arranged. And a mechanism for loading / unloading the movable core member with respect to the disk surface, wherein the loading / unloading mechanism is interlocked with a loading / unloading mechanism of the cassette of the recording medium. 2. The magneto-optical disk drive according to claim 1, wherein: 4. The core member comprises at least two or more members, one of which is a movable core member constituting one end of the gap on the side where the first bias magnetic field generator is disposed. A mechanism for independently loading / unloading the movable core member and the floating slider with respect to the disk surface, a detecting means for detecting the type of the recording medium, and a cassette loading of the recording medium. Detecting means for detecting the type of the recording medium, and driving the load / unload mechanism so as to retract the floating slider from above the disk surface based on the determination. 2. The magneto-optical disk drive according to claim 1, wherein: 5. The load / unload operation of the movable core member and the floating slider by the load / unload mechanism is performed by respective rotation operations on a common rotation support shaft. 4. The magneto-optical disk device according to 4. 6. The core member has a magnetic field emitting portion at one end arranged near a magnetic field generating portion for modulating a magnetic field so that a minute area of the light spot corresponds to the core member.
The other end is extended to the core of the magnetic circuit constituting the actuator of the objective lens, and the two bias magnetic field generators are connected to the objective lens driver by holding the core member via a heat radiating member. 2. The magneto-optical disk device according to claim 1, wherein the magneto-optical disk device operates integrally. 7. The core member is composed of at least two or more members combined so as to form a substantially ring shape having a gap portion in part, and one of the members is a first member.
A movable core member constituting one end of the gap portion on the side where the bias magnetic field generating device is disposed, and a mechanism for loading / unloading the movable core member with respect to a disk surface. 2. A magneto-optical disk drive according to claim 1, wherein a part of the / unload mechanism is made of a material and a shape having a heat radiation effect. 8. The core member is a member configured to form a substantially ring shape having a gap portion in part, and the core member has a high heat conductivity between the core member and a holding member that holds the core member. 2. The magneto-optical disk device according to claim 1, wherein the magneto-optical disk device is attached to the holding member with an elastic member interposed therebetween. 9. The magneto-optical disk drive according to claim 1, wherein a heat-generating element attached to a drive circuit of the magnetic head for magnetic field modulation is closely attached to a heat radiating member holding the core member. .