JPH04341949A - Magneto-optical recorder - Google Patents

Abstract

PURPOSE:To miniaturize a magneto-optical recorder by reducing the installed space of a magnet to form a magnetic field to be used for recording and reproduction in the magneto-optical recorder. CONSTITUTION:A cartridge holder 20 for which a cartridge 10 containing a magneto-optical disk 13 is inserted is formed of yoke materials 21, 22 made of soft iron attached with an initializing magnet 1. Accordingly, the installed space of the initializing magnet can be saved, and further, since the magnetic field is concentrated at the recessed part 25 of the U-shaped holder, the magnetic field is formed efficiently by the magnet 1.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the structure of a recording/reproducing apparatus using a magneto-optical recording medium that allows overwriting. In particular, the present invention relates to a magnetic field generating device for the recording/reproducing device.

0002

2. Description of the Related Art In recent years, research and development of high-density, large-capacity magneto-optical disks using the magneto-optic effect have been actively conducted, and the developed disks are at the stage of being put into practical use. Magneto-optical disks not only have the advantage of being able to form high-density, large-capacity recording media, but also allow for non-contact recording and playback, with fewer problems caused by damage to the recording media.
In addition, it has the advantage that it is easier to replace the medium than conventional fixed magnetic disks, so it is seen as a promising future recording medium.

[0003] When overwriting such a magneto-optical disk, it is difficult to improve the recording speed because it is necessary to record new data after erasing old data. However, several ideas have been proposed in recent years, and the optical modulation method is one of the promising methods for increasing the recording speed. A magneto-optical recording disk used in the optical modulation method is a medium having at least two layers of perpendicular magnetization films having an axis of easy magnetization perpendicular to the disk substrate, as disclosed in Japanese Patent Laid-Open No. 63-285740. It is.

FIG. 6 illustrates a method of recording and reproducing using this magneto-optical disk. In the disk substrate 13 used in this method, a recording layer 62, which is a magnetized film with a low Curie temperature and a large coercive force, is formed on the side where the laser beam 16 is incident. Laminated on this recording layer 62 is an initialization layer 63, which is a magnetized film with a high Curie temperature and a small coercive force. To overwrite this disk, first, the magnetization of the initialization layer 63 is aligned downward by a preceding initialization magnetic field Hini. This initialization magnetic field Hini is applied to the recording layer 6
Since the coercive force is set lower than that of No. 2, the initialization layer 63
However, the magnetization of the recording layer 62 is not affected. Next, when the disk 13 is irradiated with a low-power laser beam (~5 mW), the temperature of the recording layer 62 rises above the Curie temperature due to this laser beam, and the recording layer 62
The magnetization of 2 disappears. On the other hand, with this low power laser beam, the initialization layer 63 does not reach the Curie temperature, and the magnetization reversed by the initialization magnetic field Hini is maintained. The temperature of the recording layer 62 irradiated with the laser beam is cooled by the air as it passes through the laser beam spot, and magnetization appears, but at this time, the magnetization of the initialization layer 63 is transferred, so
The recording layer 62 is magnetized in the same direction as the magnetization of the initialization layer 63. Therefore, the records recorded on the recording layer 62 are erased.

On the other hand, when recording on this disc,
Irradiate with high power laser light (~9 mW). This laser beam causes the recording layer 62 and the initialization layer 63 to rise above the Curie temperature, and the magnetization of both layers disappears. Next, when an upward magnetic field is applied to this disk 13 by the recording auxiliary magnetic field Hw, the initialization layer 63 first becomes below the Curie temperature and is magnetized upward according to the magnetic field Hw. Then, when the temperature of the recording layer 62 decreases to below the Curie temperature, the magnetization of the initialization layer 63 is transferred and upward magnetization appears. In this way, data is recorded on the recording layer 62.

[0006] When overwriting data on the disk 61, according to the new data, for example, when the data is 0, a low power laser beam is irradiated, and when the data is 1, a high power laser beam is irradiated. , it is possible to record new data on the recording layer 62 regardless of the presence or absence of old data.

In a magneto-optical disk device using such a light modulation method, an initializing magnet 1 is installed to form an initializing magnetic field Hini, and a recording magnet 2 is installed to form a recording auxiliary magnetic field Hw. The initialization magnetic field Hini is between 2 and 8 k between the coercive force of the recording layer 62 and the coercive force of the initialization layer 63 to prevent magnetization reversal due to disturbance.
It is necessary to ensure the strength of Oe. For this reason, 200~
Compared to the recording magnet 2 which forms the auxiliary magnetic field Hw of 400 Oe, it is necessary to install a larger magnet as the initializing magnet 1 which forms the initializing magnetic field.

FIGS. 4 and 5 show the arrangement of the conventional initializing magnet 1 and recording magnet 2. In a conventional magneto-optical disk device, a cartridge 1 containing a disk 13 is used.
0 is provided with a window 12 that is irradiated with a laser beam, and a window 11 that faces the initialization magnet 1 and the recording magnet 2. To install the cartridge 10 into a magneto-optical disk device, first place the cartridge 10 into the cartridge holder 2.
Insert into 0. This holder 20 fixes the cartridge 10 so as to connect the hub 14 of the cartridge 10 to the spindle motor 15 of the disk device, and the windows 11 and 12 open. Next, initialization magnet 1 and recording magnet 2
approaches the disk 13 through the window 11 and is ready for recording and reproduction.

[0009]

[Problems to be Solved by the Invention] In the above device, neodymium NEOMAX (trade name) is used as the initializing magnet.
A magnetic field of about 3 kOe can be secured using a magnet with a height of about 5 mm. If the gap between this magnet and the disk is 0.5 mm, there will be at least 5.5 mm on the disk.
A space of approximately 13 mm is required, and furthermore, taking into consideration the above-described vertical movement of the cartridge 10, it is necessary to secure a space twice this amount, that is, approximately 13 mm, on the disk.

[0010] In recent years, there has been a demand for miniaturization of information processing devices, and miniaturization of disk devices is one of the challenges when designing magneto-optical disk devices. It is necessary to reduce

SUMMARY OF THE INVENTION In view of the above problems, it is an object of the present invention to reduce the space required for installing the magnets while ensuring the strength of the magnetic field, thereby reducing the size of the disk device.

0012

[Means for Solving the Problems] In order to solve the above problems, in the present invention, a magnetic field is formed by a cartridge holder. That is, the magneto-optical recording device of the present invention is characterized in that a magnetic field can be generated in a cartridge holder into which a cartridge containing a magneto-optical recording medium is inserted.

A magnetic field can be created by forming the cartridge holder from a paramagnetic material equipped with a magnet. It is desirable that this magnet be attached to the cartridge so as to face the surface on which the laser beam is irradiated, that is, on the same side as the laser beam irradiation device. Furthermore, this magnet may be a permanent magnet.

[0014] Such an apparatus can be used for recording and reproducing a magneto-optical medium having a multilayer structure including at least a recording layer and an initialization layer constituted by a perpendicularly magnetized film.

[0015]

[Operation] The cartridge holder of the above recording apparatus has a concave inner surface so that a cartridge containing a magneto-optical recording medium can be inserted therein. Therefore, when a magnetic field is generated with this holder, the magnetic field is generated inside the concave mold and across the cartridge. That is, it is formed perpendicularly to the magneto-optical recording medium housed in the cartridge. For this reason, we compared the case of forming a magnetic field with a bar-shaped magnet,
A magnetic field perpendicular to the recording medium is effectively formed without magnetic field divergence. Therefore, it is possible to secure a strong magnetic field with a small magnet.

Furthermore, since a magnetic field is generated by the cartridge holder necessary for mounting the cartridge, there is no need for a space for installing a magnet. Further, since there is no need to move the magnet up and down when the cartridge is installed in the recording device, a mechanism for moving the magnet up and down is omitted, and the space occupied by this mechanism is saved.

By forming the cartridge holder with a concave inner surface from a paramagnetic material equipped with a magnet,
A magnetic field perpendicular to the magneto-optical recording medium is created. If the cartridge holder is formed so that the direction in which the magnet is attached faces the surface that is irradiated with the laser beam, the holder with the magnet attached will move into the space where the laser beam irradiation device is installed. Space can be secured.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the present invention will be described below with reference to the drawings.

1 to 3 show a magneto-optical recording apparatus according to this embodiment. A magneto-optical disk 13 with a diameter of 3.5 inches used in the recording apparatus of this example is housed in a cartridge 10 having a substantially square shape. The disk 13 is
While housed in this cartridge 10, it is attached to a recording apparatus and rotated by a spindle motor 15 inside the cartridge 10. When installing the cartridge 10 in the device, the cartridge 10 is attached to the cartridge holder 2.
0, and the cartridge 10 is held by the cartridge holder 20 so that the hub 14 and the motor 15 are connected. Furthermore, cartridge 1
0, a window 12 is set so that the lower side of the stored disc 13 is irradiated with a laser beam 16,
While held by the cartridge holder 20, the window 1
2 is open. Also, there is a window 11 on the opposite side of this window 12.
is set, and the recording magnet 2 is installed above this.

The holder 20 is a U-shaped yoke made of soft iron, and the cartridge 10 is inserted into the U-shaped recess 25 . In this holder 20, a lower yoke 22 and an upper yoke 21 are joined with bolts 23, and the initialization magnet 1 is attached to the lower yoke 22. The initialization magnet is a neodymium-based N
It is a permanent magnet made of EOMAX (trade name), and its thickness is 3.5 mm. Further, the thickness of the lower yoke 22 and the upper yoke 21 are each 3.5 mm.

The functions of the magneto-optical recording apparatus of this example are the same as those of the conventional example described above, so the same numbers will be assigned and the explanation will be omitted. The point to note in this example is that the initialization magnet 1 is incorporated into the cartridge holder 20. As described above, since this cartridge holder 20 is made of soft iron, which is a paramagnetic material, and has a U-shape, the magnetic field is concentrated in the recess 25 of this holder 20. and,
Since the disk 13 housed in the cartridge 10 is inserted into this recess 25, a magnetic field is formed perpendicular to the disk 13. Therefore, the magnetic field of the initialization magnet 1 effectively acts on the disk 13, so the magnet 1 can be made smaller than the conventional one. In this example, the conventional 5mm
The thickness of the initialization magnet 1 is 3.5 m.
It can be composed of m magnets.

When attaching the magnet 1 to the cartridge holder 20, the dimensions of the cartridge holder 20 are slightly larger than those of conventional apparatuses. However, the magnet 1 is attached to the lower yoke 22 of the cartridge holder 20, that is, the motor 15 and the laser beam 1.
It can be installed so that it becomes larger toward the space where the irradiation device No. 6 is housed. Since this space is a section prepared for storing the above-mentioned apparatus, the holder 20 of this example can be attached to the recording apparatus without changing the size of the recording apparatus.

Furthermore, in the recording device of this example, since the initialization magnet 1 is built into the holder 20, it is not necessary to move the magnet 1 up and down when installing the cartridge 10 in the device, as in conventional devices. disappears. Therefore, a mechanism for moving the magnet 1 can be omitted, and the device can be further downsized. As mentioned above, in the recording magnet 2, the required magnetic field strength is about 1/10 of that of the initialization magnet 1, so as in the past, a small magnet is moved close to the disk 13 using a vertical mechanism. Alternatively, as shown in FIG. 3, it is possible to obtain the necessary magnetic field by fixing it above the disk. Therefore, the influence of the recording magnet 2 on the dimensions of the recording device is small.

In this example, the holder is made of soft iron and a permanent magnet, but the holder may be made of an amorphous alloy or the like, and it is of course possible to manufacture it with a permanent magnet. Further, the structure is not limited to permanent magnets, and may be constructed using electromagnets or the like.

[0025]

As explained above, the magneto-optical recording device according to the present invention generates a magnetic field for recording and reproduction by the holder that fixes the cartridge containing the magneto-optical recording medium to the device. It becomes possible to save installation space for the magnets that form this magnetic field. Therefore, it is possible to downsize the recording apparatus. Furthermore, the holder is U-shaped so that the cartridge can be inserted, and since the magnetic field is concentrated in this recess, the magnetic field can be generated using a smaller magnet than in the past.

Furthermore, since the magnet for recording and reproducing can be omitted, the mechanism for moving the magnet up and down can be omitted, and it is also possible to downsize the recording apparatus.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing a state in which a cartridge is installed in a magneto-optical recording device according to an embodiment of the present invention.

FIG. 2 is a sectional view showing the structure of a holder in the device shown in FIG. 1;

FIG. 3 is a sectional view showing the configuration of the device shown in FIG. 1.

FIG. 4 is an explanatory diagram showing a state in which a cartridge is installed in a conventional magneto-optical recording device.

FIG. 5 is a sectional view showing the configuration of the device shown in FIG. 4;

6 is an explanatory diagram showing a recording method using a light modulation method by the recording apparatus shown in FIGS. 1 and 4. FIG.

[Explanation of symbols]

1...Initialization magnet 2...Recording magnet 10...Cartridges 11, 12...Window 13...Magneto-optical disk 14...Hub 15...Spindle motor 16...Laser light 20 ...Cartridge holder 21...Yoke upper part 22...Yoke lower part 23...Bolt 25...Recessed part 61 of cartridge holder...Recording layer 62...Initialization layer Hini...Initialization magnetic field Hw... Recording auxiliary magnetic field

Claims (5)

[Claims] 1. A magneto-optical recording device comprising a cartridge holder into which a cartridge containing a magneto-optical recording medium is inserted, wherein a magnetic field is generated by the cartridge holder. 2. The magneto-optical recording device according to claim 1, wherein the cartridge holder is made of a paramagnetic material equipped with a magnet. 3. The magneto-optical recording device according to claim 2, wherein the magnet is mounted on the cartridge holder so as to face a surface of the cartridge that is irradiated with laser light. 4. The magneto-optical recording device according to claim 2, wherein the magnet is a permanent magnet. 5. According to any one of claims 1 to 4, the magneto-optical recording medium is a magneto-optical recording medium having a multilayer structure including at least a recording layer and an initialization layer constituted by a perpendicular magnetization film. A magneto-optical recording device characterized by the following.