JPH06103636A - Magneto-optical disk device - Google Patents

Abstract

PURPOSE:To record information with an optimum power at all times and to improve CN ratio by irradiating over entire sector with laser beams with outgoing power larger than the outgoing power at the time of erasure in the case when an unused magneto-optical disk is mounted. CONSTITUTION:After forming a film in the process of manufacture, the driving conditions of a disk stabilizing processing are recorded in the bender unique area of a specific sector in the magneto-optical disk 11. When the unused disk 11 is mounted on a device, the record information of the bender unique area is read with rated driving conditions. Then, basing on the read driving conditions, the laser beam with the outgoing power larger than the one at the time of the normal erasure is radiated over the entire sectors and at the same time, magnetic field in a direction same as the data erasure time is impressed. Thus, a recording layer is heated up to a high temperature, the amorphous structure of the recording layer is fluctuated and is stabilized. At this time, the data of the respective sectors are erased. Thereafter, the driving conditions are returned to the rated conditions and a normal operation is performed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk exchange type magneto-optical disk device.

[0002]

2. Description of the Related Art A disk exchange type magneto-optical disk device is well known in which a cartridge accommodating a magneto-optical disk can be arbitrarily mounted in or replaced with a drive device.

A magneto-optical disk device irradiates a laser beam on a recording track of the magneto-optical disk and applies a magnetic field to record information or erase recorded information.
Further, the recording information is read by irradiating the recording track with laser light and detecting reflected light.

A CN ratio (Carrier to Noise rat) is used as an evaluation scale for reading recorded information.
There is io). The larger the CN ratio, the better, but it changes due to various factors.

For example, when the disc rotation speed is constant, the CN ratio changes depending on the emission power of laser light during information recording, and becomes maximum when the emission power has a certain value. Therefore, the specific emission power becomes the optimum power of the laser beam at the time of recording information.

By the way, a recording layer is formed on a recording track of a magneto-optical disk by a magnetic material having an amorphous structure.

When a recording track is irradiated with a laser beam for recording, erasing or reading information, the recording layer is temporarily heated. At the time of recording or erasing information, laser light with a considerably large emission power is applied as compared with the time of reading. In this case, the recording layer is temporarily heated to a high temperature of 200 ° C.

It is known that when the recording layer is heated, the amorphous structure changes and the coercive force of the recording layer decreases. When the holding power is lowered, the optimum power of the laser beam at the time of recording the information is also lowered.

As a result, the optimum power is, for example,
As shown in FIG. 5, it is high in the unused magneto-optical disk,
If you record or erase information repeatedly, it will decrease,
After that, it stabilizes at a nearly constant value. It should be noted that such a decrease in the optimum power is the same between different sectors on the same disk.

[0010]

However, in the conventional magneto-optical disk device, when information is recorded, the magneto-optical disk is always irradiated with laser light at a constant emission power which is the optimum power of an unused magneto-optical disk. I was trying to do it.

Therefore, when a magneto-optical disk in which information recording and erasing are repeated many times is used, information recording is performed with a laser beam having a higher emission power, although the optimum power is reduced. Was. Therefore, there is a problem that the CN ratio is lowered when reading the recorded information.

It is an object of the present invention to provide a magneto-optical disk device which solves the above problems and can always record information with an optimum power and improve the CN ratio.

[0013]

To this end, according to the present invention, when an unused magneto-optical disk is mounted, a laser beam having an emission power larger than the emission power at the time of erasing recorded information is used as the magneto-optical signal. It is characterized in that irradiation is performed once or more over all sectors on the recording track of the disk.

[0014]

When the recording layer is heated to a very high temperature by irradiating all the sectors of the magneto-optical disk with the laser beam having a large emission power as described above, the case where the recording and erasing of information is repeated many times Similarly, the amorphous structure changes and stabilizes. As a result, the optimum power of the laser light is reduced and kept almost constant from the time of the first recording of information. By recording the information with the constant power, the information is always recorded with the optimum power and the CN ratio is improved. be able to.

[0015]

Embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

FIG. 1 is a block diagram of a magneto-optical disk device according to an embodiment of the present invention. In the figure, a disc cartridge 1 is configured to be detachable from the magneto-optical disc device, and a magneto-optical disc 11 is housed inside. Magneto-optical disk 11
Are driven to rotate by the spindle motor 2. The magnetic head 3 applies a magnetic field to the magneto-optical disk 11 as needed. Optical pickup 4
Is for irradiating the recording track of the magneto-optical disk 11 with laser light and receiving the reflected light to extract various signals. The seek motor 5 is a magneto-optical disk 11
The optical pickup 4 is driven in order to move the irradiation position of the laser beam to the optical pickup 4.

The data recording / reproducing unit 6 includes an optical pickup 4
Control data to record data on the magneto-optical disk 11,
The magneto-optical disk 1 from the signal obtained by the optical pickup 4.
The recorded data of No. 1 is reproduced. The interface section 7 inputs command information and data to be recorded from a host computer (not shown), and outputs reproduced data to the host computer.

The control unit 8 controls each of the above units. The controller 8 has a laser emission power adjusting function, a rotation speed adjusting function, and a magnetic field strength adjusting function. The laser emission power adjusting function is a function of adjusting the power of the laser light emitted from the optical pickup 4 to a designated value. The rotation speed adjustment function is a function of adjusting the speed at which the magneto-optical disk 11 is rotated by the spindle motor 2 to a designated speed. The magnetic field strength adjusting function is a function of adjusting the magnetic field strength applied by the magnetic head 3 to a designated strength.

As shown in FIG. 2, the magneto-optical disk 11 has a protective layer 11 formed on a substrate 111 by a sputtering method or the like.
2, the recording layer 113, the protective layer 114, and the reflective layer 115 are sequentially formed. The substrate 111 is, for example, polycarbonate, and the recording layer 113 is a magnetic material having an amorphous structure.

The magneto-optical disk 11 has an ISO (Int
international Organization f
or Standardization), a recording track and each sector are formed. A data area and an error correction code area are formed in each sector. The data area is, for example, 512
It is composed of a byte user data area, a 4-byte vendor unique area, and a 4-byte error detection code area. The user data area is an area where the user can arbitrarily record and reproduce data. The vendor unique area is an area that the device manufacturer can use for any purpose.

In the magneto-optical disk 11 of the present embodiment having the above-described structure, after the film formation in the manufacturing process, the drive condition of the disk stabilizing process is recorded in the vendor unique area of the specific sector. The disc stabilization process is a process described later, which is executed to stabilize the amorphous structure of the recording layer 113 in the present embodiment. The drive conditions are the disk rotation speed, the laser beam emission power, and the magnetic field strength.

Next, the operation of the magneto-optical disk device of this embodiment will be described.

When using this magneto-optical disk device, the operator mounts a desired magneto-optical disk 11 on the device (process 1001).

The magneto-optical disk device comprises a magneto-optical disk 1
When No. 1 is mounted, the recorded information in the vendor unique area of the specific sector is read under the rated drive condition (process 100).
2). The rated drive conditions are the normal disk rotation speed and the laser beam emission power, which are determined when recording / reproducing data on / from the magneto-optical disk 11.

Then, it is judged whether or not the drive condition for the disk stabilizing process is recorded in the vendor unique area (process 1003). If the drive condition is recorded (Y in step 1003), the magneto-optical disk device is set to the drive condition.

In the present embodiment, the disk rotation speed, the laser beam emission power, and the magnetic field strength are designated as the driving conditions. In this case, the disc rotation speed and the laser beam emission power specify values at which the action of the laser beam on the recording layer 113 is larger than that during normal data erasing. That is, when the disk rotation speed is designated as the same value as the rated speed, the emission power of the laser light is set to a value larger than the emission power at the time of erasing data. For example, if the emission power at the time of erasing data is 10 mW, the output power is doubled to 20 mW. on the other hand,
When the disc rotation speed is reduced, the action of the laser light becomes large. Therefore, when the disc rotation speed is specified to be lower than the rated speed, the emission power is specified to be lower than the above case. If you want to make it higher than the rated speed,
Specify higher than the above case. Further, the magnetic field strength is designated to a value that is the same as or larger than that during normal data erasing, for example, 100 Oe to 1000 Oe.

The magneto-optical disk device sets the drive conditions designated as described above (process 1004).

Next, under the driving conditions, laser light is irradiated and a magnetic field is applied to all the sectors of the recording track of the magneto-optical disk 11. The magnetic field application direction at this time is the same as that at the time of erasing data.

In this case, the driving conditions are set so that the action of the laser beam on the recording layer 113 is larger than that during normal data erasing, so that the recording layer 113 covers all the sectors of the recording track at a very high temperature. Sequentially heated. By this heating, the amorphous structure of the recording layer 113 changes and becomes stable. That is, this operation is the disk stabilizing process of this embodiment.

At this time, since the magnetic field is applied at the same time, the data in each sector is initialized, that is, the recorded data is erased. Therefore, the information on the driving condition recorded in the vendor unique area is also erased here (the process 1005).

After this operation, the driving condition is returned to the rated condition (process 1006). Then, according to an instruction from the host computer, a known operation such as recording data on the magneto-optical disk 11, reading the recording data, or erasing the recording data is executed (process 1007). In this case, the magneto-optical disk 11 is rotationally driven at the rated speed, while the emission power of the laser light is adjusted to a predetermined emission power for each operation of recording, reading and erasing data.

Next, assuming that the magneto-optical disk 11 that has been used once is mounted in this magneto-optical disk device, the information on the driving condition in the vendor unique area is erased.

In this case (N in process 1003), normal operation is executed as it is under the rated condition (process 1007).

As described above, in the present embodiment, when a new unused magneto-optical disk 11 is mounted on the magneto-optical disk device, laser light having a large emission power is distributed over all sectors on the recording track. The disk stabilization process for irradiation is executed.

As a result, the recording layer 113 of the magneto-optical disk 11 is heated to a high temperature, and the amorphous structure changes and becomes stable as in the case where data recording and erasing are repeated many times. As a result, the optimum power of the laser light is lowered with respect to the initial value, and as shown in FIG. 4, the optimum power is kept almost constant from the time of recording the first information.

Therefore, since the magneto-optical disk device records data with the constant power, information can be always recorded with the optimum power, and the CN ratio is improved.

In the stabilization process, the magnetic field in a constant direction is applied to the magneto-optical disk 11 along with the irradiation of the laser beam, so that the recorded data is erased at the same time, that is, the magneto-optical disk 11 is initialized. You can

Further, the driving conditions for executing the stabilizing process, that is, the emission power of the laser beam, the disk rotation speed and the magnetic field strength are recorded in advance in the vendor unique area of the specific sector, and the operation is performed according to the driving conditions. I am trying. As a result, even when various types of magneto-optical disks 11 having different sensitivities to laser light are used, it is possible to automatically set the driving conditions suitable for the respective magneto-optical disks 11 and reliably execute the stabilization process. Like

Since the driving condition is recorded in the vendor unique area, it does not affect the user data area. Further, the record information of the driving condition is erased by the above initialization in the stabilization process. The optical disc device, when the magneto-optical disc 11 is mounted,
Since the driving condition information is checked and the stabilizing process is executed when it is recorded, the stabilizing process can be correctly executed only on the unused magneto-optical disk 11.

In the above-described embodiment, the driving conditions for the stabilization process are specified by the three conditions of laser beam emission power, disk rotation speed, and magnetic field strength.
If the disk rotation speed is not changed by the stabilization process, that information is unnecessary. In addition, when the initialization operation is not performed, the information on the magnetic field strength is unnecessary.

Further, the driving conditions are supposed to be recorded in a specific vendor unique area of one sector, but may be recorded in a plurality of sectors. It is also conceivable to record in the user data area of a specific sector.

Further, it is determined whether or not the mounted magneto-optical disk 11 has been subjected to the stabilization processing with or without the recording information of the above driving conditions. However, after the stabilization processing is completed, specific identification information is obtained. May be recorded in a specific sector.

Further, in the stabilization process, the laser light is irradiated only once over all the sectors, but it goes without saying that it may be irradiated plural times.

[0044]

As described above, according to the present invention, when an unused magneto-optical disk is mounted, laser light having a large emission power is distributed over all sectors on the recording track of the magneto-optical disk. Since the irradiation is performed at least once, the amorphous structure of the recording layer is stabilized,
Since the optimum power of the laser beam is lowered and kept at a constant value, by recording information at the constant power, it is possible to always record information at the optimum power and improve the CN ratio.

[Brief description of drawings]

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

FIG. 2 is a partial sectional view of a hierarchical structure of a magneto-optical disk.

FIG. 3 is an operation flowchart of the magneto-optical disk device.

FIG. 4 is a graph showing the state of optimum power of laser light in the magneto-optical disk device of this embodiment.

FIG. 5 is a graph showing a change in optimum power of laser light in a conventional magneto-optical disk device.

[Explanation of symbols]

 1 disk cartridge 2 spindle motor 3 magnetic head 4 optical pickup 5 seek motor 6 data recording / reproducing section 7 interface section 8 control section 11 magneto-optical disk 111 substrate 112, 114 protective layer 113 recording layer 115 reflective layer

Claims (4)

[Claims] 1. An arbitrarily mounted magneto-optical disk is rotatably driven, and a recording track of the magneto-optical disk is irradiated with a laser beam and a magnetic field is applied to erase recorded information in each sector and re-write information. In a magneto-optical disk device for performing arbitrary recording, when an unused magneto-optical disk is mounted, laser light having an emission power larger than the emission power at the time of erasing the recorded information is recorded on a recording track of the magneto-optical disk. A magneto-optical disk device comprising a recording layer stabilizing means for irradiating all sectors once or more. 2. A means for reading each value of an emission power and a disk rotation speed recorded in a certain area of a certain sector of the magneto-optical disk, and the read value when the recording layer stabilizing means is executed. 2. The magneto-optical disk device according to claim 1, further comprising: a means for rotationally driving the magneto-optical disk at a rotation speed; and a means for irradiating the read laser beam having the emission power value. 3. A means for initializing the recording information of each sector by applying a magnetic field in a fixed direction together with the laser beam when the operation of the recording layer stabilizing means is executed. 1. The magneto-optical disk device described in 1. 4. When the magneto-optical disk is mounted and the information of the emission power and the disk rotation speed is recorded in a certain area of the certain sector, the operation of the recording layer stabilizing means is automatically started. 4. The magneto-optical disk device according to claim 3, further comprising: