JPH05314562A - Magneto-optical disk and its initializing method and magneto-optical recording device - Google Patents

Abstract

PURPOSE:To provide a magneto-optical disk and its initializing method and a magneto-optical recording device in order to increase the storage capacity and to obtain a format in accordance with the user specifications. CONSTITUTION:A wobbling group 11 is previously formed on a magneto-optical disk 1, and the length WL of each wave of the group 11 is set equal over an entire disk. In other words, the wobbling is carried out at a certain frequency and the constant linear velocity CLV control is carried out so that constant wobbling frequency is also secured even in a reproduction state.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording / reproducing magneto-optical disk, and more particularly to a wobbling groove as a guide groove, a method for initializing the magneto-optical disk, and a magneto-optical recording apparatus.

[0002]

2. Description of the Related Art In a magneto-optical disk used in an information processing system or the like, a wobbling groove as a guide groove is formed in a spiral shape, for example, and information is recorded along the wobbling groove. Generally, this information recording area is divided into a plurality of sectors having a fixed length, and information is exchanged with an external device in sector units. One sector SCT on this magneto-optical disk is
Mainly as shown in FIG. 5, an address information area ADR indicating a position on a disc where a plurality of so-called embossed pits PT are pre-formatted at the same time as a wobbling groove during manufacturing, and a data area DT in which various information is recorded.
It is composed of A and. Information is recorded in the data area DTA by, for example, irradiating a recording layer of a magneto-optical disk with a laser beam spot having a certain intensity by an optical head, in response to signals "1" and "0" by the magnetic head. This is done by reversing the external magnetic field. Further, the recording information is reproduced by irradiating the data area DTA of the sector SCT of the predetermined address with the laser light spot by the optical head and reading the magnetization direction of the so-called recording bit.

As the disk format of the magneto-optical disk, various formats have been proposed for taking a large storage capacity, recording desired information at a target address, and reproducing it with high reliability. As a method, corresponding to the speed control method of the spindle motor,
A CLV (Constant Linear Velocity) method and a CAV (Constant Angular Velocity) method have been proposed.

The CLV system controls the spindle motor so that the rotational speed is inversely proportional to the track radius so that the linear velocity of the track for recording / reproducing becomes constant anywhere on the disk. Therefore, as the disc format, as shown in FIG. _6A , a plurality of sectors SCT _CLV having a constant length are continuously formed on the spiral track from the inner circumference side to the outer circumference side of the disk. In such a disc format, data can be recorded in synchronization with a constant clock, and data having a constant frequency can be reproduced by reproducing the recorded data. In the CLV method, the recording and reproducing conditions such as the recording laser power may be almost the same at any position on the disc, and the storage capacity can be increased.

The CAV method makes the rotation speed of the spindle motor and the recording / reproducing frequency constant. Therefore, as shown in FIG. 7A, the disk format is configured by evenly dividing the entire circumference of the disk into a plurality of areas and allocating each divided area as a sector SCT _CAV . Therefore, the sector length is smaller on the inner circumference side and larger on the outer circumference side. In the CAV method, although the circuit system is simple and the spindle motor can be downsized, the storage capacity per track is determined by the number of marks that can be recorded on the innermost circumference of the disk recording area, so the storage capacity of the entire disk is reduced. ..

Therefore, in the present day when the storage capacity of the magneto-optical disk is required to be increased, it is desirable to adopt the CLV system to increase the storage capacity.

[0007]

[Problems to be Solved by the Invention] However, CLV
In the method, since all the sectors SCT _CLV are set to the same length, as shown in (b) of FIG. 6, the address information areas of the adjacent tracks TR _n-1 , TR _n , TR _{n + 1} are set. Since the ADR and the data area DTA overlap each other, the recording information of the data area DTA recorded by a so-called magnetic signal (MO signal) is hardly affected, but a track adjacent to the data area DTA of a certain track is being accessed. Are easily affected by the embossed pits PT in the address information area ADR, which causes crosstalk. For this reason, at present, as shown in FIG. 7B, it is unavoidable to adopt the CAV method which employs the sector arrangement method in which the address information areas ADR are arranged in a predetermined direction between adjacent tracks. Therefore, the present magneto-optical disk format cannot increase the storage capacity. To solve this, a so-called zoning method can be considered in the CAV method. In this case,
It is difficult to control because the clock changes, and the recording density is CLV.
It does not reach the method.

In addition, since the present magneto-optical disk is pre-formatted at the time of manufacture and the sector size is defined in advance, it is not possible to set the sector size that meets the needs of the user, and the range of use is restricted. Will end up.

The present invention has been made in view of the above circumstances, and an object thereof is to increase the storage capacity, and
An object of the present invention is to provide a magneto-optical disk capable of being formatted according to user's specifications, an initialization method thereof, and a magneto-optical recording device.

[0010]

In order to achieve the above object, according to the present invention, a wobbling groove is formed in advance in a magneto-optical disk, and the length of one wave of the wobbling groove is set to be the same in the entire disk. The proposed magneto-optical disk is proposed.

Further, according to the present invention, the wobbling frequency is detected by the diffracted light of the light irradiating the wobbling groove in which the length of one wave of the magneto-optical disk is set to be the same over the entire disk, and the wobbling frequency becomes constant. Control the rotation of the magneto-optical disk, and generate a master clock signal from the detected wobbling frequency,
We propose a method for initializing a magneto-optical disk that modulates specified data from the outside based on a master clock signal, performs sector division based on the modulated data, and records address information in each sector by a magnetic signal.

Further, according to the present invention, a means for irradiating a laser beam onto a magneto-optical disk in which one wave length of a wobbling groove is set to be the same for the entire disk and detecting diffracted light in the magneto-optical disk. And a means for detecting the wobbling frequency based on the detected diffracted light, and the detected wobbling frequency is compared with a preset reference frequency to control the rotation of the magneto-optical disk so that the wobbling frequency becomes constant. Means for performing, a means for generating a master clock signal from the detected wobbling frequency, a means for modulating externally designated data based on the master clock signal, and a laser beam irradiation area of the magneto-optical disk based on the modulated data A magneto-optical recording device for a magneto-optical disk having means for writing a magnetic signal on .

[0013]

According to the magneto-optical disk of the present invention, the so-called C
The wobbling frequency used in the wobbling groove of the DMO is not FM-modulated in advance to write the time and address information.
Wobbling is performed at a constant frequency, and constant linear velocity control (CLV) is performed so that the wobbling frequency is constant during reproduction.

According to the initialization method of the present invention, the wobbling groove of the magneto-optical disk is irradiated with light, and the wobbling frequency is detected by the diffracted light of the irradiated light.
The rotation control of the magneto-optical disk is performed so that the wobbling frequency becomes constant. In this state, a master clock signal is generated from the detected wobbling frequency, and externally designated data is modulated based on the master clock signal. Based on this modulation data, sector division is performed based on, for example, the wave number of the wobbling groove, and address information is recorded in each sector by a magnetic signal.

According to the magneto-optical recording apparatus of the present invention, the diffracted light detecting means irradiates the magneto-optical disk with laser light, the diffracted light in the wobbling groove of the irradiated light is detected, and the detection result is the wobbling frequency detecting means. Is output to. The wobbling frequency detecting means detects the wobbling frequency based on the input detection result,
The detection result is output to the rotation control means and the clock generation means. The rotation control means compares the detected wobbling frequency with a preset reference frequency, and controls the rotation of the magneto-optical disk so that the wobbling frequency becomes constant based on the comparison result. On the other hand, in the clock signal generating means, the master clock signal is generated from the input wobbling frequency,
It is output to the modulation means. The modulation means modulates the designated data from the outside based on the master clock signal, outputs the data to the magnetic signal writing means, and writes the magnetic signal to the laser light irradiation area of the disk based on the modulation data.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a schematic view of the essential parts of an embodiment of a magneto-optical disk according to the present invention. In the figure, reference numeral 1 denotes a magneto-optical disk, in which a so-called wobbling groove 11 is precut as a guide groove in a spiral shape from a predetermined position on the inner circumference side to a predetermined position on the outer circumference side as a guide groove. The wobbling groove 11 is formed so that its wave length WL is constant over the entire disc. Specifically, the length WL of one wave of the wobbling groove 11 is set to 56.84 μm, for example.

The wobbling groove 11 is formed and the magneto-optical disk 1 is manufactured as follows. That is, for example, as shown in FIG. 2 (a), a glass disk 13 coated with a photoresist 12 is set on a spindle motor MT which is controlled to have a constant linear velocity by the CLV method, and is rotated at a constant linear velocity. By irradiating the photoresist 12 on the glass disk 13 to be irradiated with the laser beam LO which is reflected by the galvano-mirror MR rotated based on the control signal and is wobbled in the radial direction of the disk, the spiral shape is obtained. Then, the wobbling groove that has been wobbled is exposed. Next, this glass master is developed. As a result, a recess corresponding to the wobbling groove 11 is formed in the photoresist 12, as shown in FIG. Then, as shown in FIG. 2 (c), aluminum 14 is vapor-deposited on the photoresist 12, and nickel plating 15 is applied as shown in FIG. 2 (d).
By removing this nickel plating 15,
A metal master is prepared as shown in (e). A stamper is produced from this metal master, and the magneto-optical disk 1 is manufactured as shown in FIG. 2 (f) through the steps of injection molding, recording layer formation, and protective film addition by the stamper.

The magneto-optical disk 1 manufactured in this way
Has a polycarbonate substrate 16, a recording layer 17, and a transparent protective film 18, for example, and the wobbling groove 11 is formed in the recording layer 17. The wobbling groove 11 is formed in a U groove or a V groove. Also, the recording layer 1
7 is made of a material such as TbFeCo.

For the present magneto-optical disk 1, ATIP (Accurate Time In Phase) as used in the so-called CDMO wobbling groove, specifically, the wobbling frequency is further FM-modulated to obtain time and address information. Is not written in advance. That is, wobbling is performed with a constant frequency, for example, a single carrier of 22.05 kHz when the linear velocity is 1.2 m, and constant linear velocity control (CLV) is performed so that the wobbling frequency is constant during reproduction.

The magneto-optical disk 1 constructed as described above.
CLV control is possible, but since sector address information such as so-called sector allocation for data storage is not included, formatting of the magneto-optical disk 1 is performed by the user's magneto-optical recording device, and The sector address information is arbitrarily written by the user with a so-called MO signal.

FIG. 3 is a block diagram showing an embodiment of a magneto-optical recording apparatus capable of formatting the magneto-optical disk 1. In FIG. 3, 1 is a magneto-optical disk, 2 is a spindle motor, 3 is an optical head (optical pickup) adopting a so-called push-pull method, 4 is a magnetic head, 5 is a spindle motor drive circuit, and 6 is arranged in the optical head 3. For controlling driving of a semiconductor laser (LD) which is not shown
Reference numeral 7 is a drive circuit, 7 is a head amplifier, 8 is a magnetic head drive circuit, 9 is a phase comparison circuit, 10 is a PLL circuit, 11 is a modulation circuit, and 12 is an interface circuit with a host computer or the like.

Although not shown, the optical head 3 is mainly L
An LD that emits laser light under the control of the D drive circuit 6,
A collimator that converts laser light from an LD into parallel light;
The light emitted from the collimator is transmitted, and the light that is reflected and diffracted by the wobbling groove 11 of the disc is reflected in a direction orthogonal to the incident direction of the light emitted from the collimator, and the light transmitted through the beam splitter is condensed to form a light spot. As an objective lens for irradiating the recording surface of the magneto-optical disk 1, an actuator for the objective lens, a condenser lens for condensing the reflected diffracted light of the beam splitter, and two divisions symmetrically arranged with respect to the center of the track. -With a photodetector. That is, the optical head uses the push-pull method.

The drive current of the magnetic head 4 is controlled by the magnetic head drive circuit 8, and a predetermined magnetic field is applied to the laser light irradiation area of the optical head 3. At this time, the application direction of the magnetic field is reversed according to "1" and "0" of the signal.

The spindle motor drive circuit 5 controls the rotation of the spindle motor 2 according to the comparison result of the phase comparison circuit 9 by CLV (constant linear velocity).

The LD drive circuit 6 is L in the optical head 3 according to the write data WD modulated by the modulation circuit 11.
D drive control is performed.

The head amplifier 7 obtains a reproduction signal RD from an output signal of a two-division-photodetector (not shown) of the optical head 3, detects the wobbling frequency of the so-called wobbling groove 11 of the magneto-optical disk 1, and push-pull signal PPS. To generate.

The magnetic head drive circuit 8 responds to the write data WD modulated by the modulation circuit 11 according to the write data WD.
Drive current is controlled.

The phase comparison circuit 9 compares the phase of the push-pull signal PPS generated by the head amplifier 7 with a preset reference frequency Ref, and outputs the result to the spindle motor drive circuit 5. The above head amplifier 7, phase comparison circuit 9, spindle motor drive circuit 5 and spindle motor 2 constitute a closed loop for CLV control. For example, when the reference frequency Ref is set to 22.05 kHz, the linear velocity is constant at 1.2 m / s and the reference frequency Ref is set to 88.2kHz, the linear velocity is constant 4.8m /
controlled by s.

The PLL circuit 10 has a push-pull signal PP.
S is input, the wobbling frequency is multiplied by 196 to generate a master clock signal MCLK, which is output to the modulation circuit 11. For example, the frequency 88.2 kHz is multiplied by 196 to generate the master clock signal MCLK of 17.3 MHz.

The modulation circuit 11 is an interface circuit 12
Write data from the host device input via
Master clock signal MCL generated by LL circuit 10
Based on K, for example, EFM (Eight to Fourteen Mod
modulation) and output as write data WD to the LD drive circuit 6 and the magnetic head drive circuit 8.

Next, the operation of initializing the magneto-optical disk of FIG. 1 using the above apparatus will be described. First,
The magneto-optical disk 1 in which address information and the like are not recorded and only the wobbling groove 11 is precut is set on the spindle of the spindle motor 2. Here, the spindle motor 2 is rotated and the optical head 3
A laser beam spot is irradiated onto the magneto-optical disk 1. The apparatus performs tracking on the wobbling lube 11 by a tracking servo system based on the reflected and diffracted light from the magneto-optical disk 1.

Next, the wobbling frequency is detected in the head amplifier 7 by the above push-pull detection,
The push-pull signal PPS based on this is the phase comparison circuit 9
And to the PLL circuit 10. In the phase comparison circuit 9, the wobbling frequency and the reference frequency Ref are compared in phase, and in accordance with the comparison result, the spindle motor drive circuit 5 performs CLV rotation control so that the spindle motor 2 rotates at a constant linear velocity. ..

The PLL circuit 10 generates a master clock signal MCLK necessary for formatting and outputs it to the modulation circuit 11. At this time, the initialization specification data is sent from the host side, and this initialization specification data is
It is input to the modulation circuit 11 via the interface circuit 12.

In the modulation circuit 11, for example, input data is subjected to processing such as EFM modulation to generate write data WD, which is output to the LD drive circuit 6 and the magnetic head drive circuit 8. As a result, sector allocation is performed based on the initialization designation data, and sector address information is recorded as a MO signal at the beginning of each sector, and this is over the entire user-usable area of the magneto-optical disc 1. Done.

FIG. 4 shows an example of the format of the magneto-optical disk 1. In this example, the sector is defined as 2048 bytes (or 2352 bytes) and formatted. In this case, as shown in FIG. 4, sectors are accurately divided for each wobbling 294 waves,
In the first three waves (1764 master clock) of each sector SCT, various information of sector address, reference, and control are written by MO signal.

The magneto-optical disk 1 thus formatted is sought and accessed by the address information in the address information area ADR written by the MO signal, and data is written, rewritten, or written only in the data area DTA. Erase is performed.

As described above, according to this embodiment,
The magneto-optical disc 1 has a wobbling groove 1 whose wobbling frequency is set to be constant over the entire disc at the time of manufacture.
Only 1 is formed, and the address information etc.
Since it can be recorded arbitrarily with the O signal, all sectors SCT _CLV are set to the same length as shown in (a) of FIG.
As shown in FIG. 6B, the adjacent tracks TR _n-1 ,
Even _if the CLV method in which the address information area ADR of TR _n and TR _{n + 1} and the data area DTA overlap each other is adopted, since there is no emboss pit as in the conventional case, the influence of the address information area ADR of the adjacent track is reduced. The occurrence of crosstalk can be prevented with almost no reception. Therefore, the present magneto-optical disk can increase the storage capacity.

Further, in the present magneto-optical disk, only the wobbling groove 11 is pre-cut at the time of manufacture, and the sector size is not specified in advance, so that the sector size can be arbitrarily set according to the user's needs. A wide range of magneto-optical disks can be realized.

In the above description, the example in which the sector is formatted as 2K bytes is shown, but the present invention is not limited to this, 512 bytes, 1K (1024 bytes).
Alternatively, it goes without saying that the so-called streaming data of audio / video can be arbitrarily set according to the user's specifications.

[0040]

As described above, according to the present invention,
Since only the wobbling groove in which the wobbling frequency is set to be constant over the entire disc is formed at the time of manufacture, and the address information and the like can be arbitrarily recorded by the user with the MO signal, all sectors are set to the same length and adjacent tracks are set. Even if the CLV system in which the address information area and the data area overlap each other is adopted, since there is no emboss pit as in the conventional case, it is hardly affected by the address information areas of adjacent tracks, and crosstalk occurs. Can be prevented. Therefore,
According to the present magneto-optical disk, the storage capacity can be increased.

In addition, since only the wobbling groove is precut at the time of manufacture and the sector size is not specified in advance, it is possible to arbitrarily set the sector size that meets the needs of the user, and a magneto-optical disk having a wide range of application can be obtained. realizable.

[Brief description of drawings]

FIG. 1 is a schematic view of a main part showing an embodiment of a magneto-optical disk according to the present invention.

FIG. 2 is an explanatory view of a method of forming a wobbling groove and a method of manufacturing a magneto-optical disk according to the present invention.

3 is a configuration diagram showing an embodiment of a magneto-optical recording device capable of formatting the magneto-optical disc of FIG.

FIG. 4 is a diagram showing a format example of a magneto-optical disk according to the present invention.

FIG. 5 is an explanatory diagram of a conventional sector format.

FIG. 6 is an explanatory diagram of a CLV system.

FIG. 7 is an explanatory diagram of a CAV method.

[Explanation of Codes] 1 ... Magneto-optical disk 11 ... Wobbling groove 2 ... Spindle motor 3 ... Optical head 4 ... Magnetic head 5 ... Spindle motor drive circuit 6 ... LD drive circuit 7 ... Head amplifier 8 ... Magnetic head drive circuit 9 ... Phase Comparator circuit 10 ... PLL circuit 11 ... Modulation circuit 12 ... Interface circuit

Claims (3)

[Claims] 1. A magneto-optical disk in which wobbling grooves are formed in advance, wherein the length of one wave of the wobbling grooves is set to be the same in the entire disk. 2. The wobbling frequency is detected by the diffracted light of the light irradiated to the wobbling groove in which the length of one wave of the magneto-optical disk is set to be the same on the entire disk, and the wobbling frequency is kept constant. Controls the rotation of the disk, generates a master clock signal from the detected wobbling frequency, modulates externally specified data based on the master clock signal, performs sector division based on the modulated data, and A method for initializing a magneto-optical disk, characterized in that address information is recorded on the disk by magnetic signals. 3. A means for irradiating a laser beam onto a magneto-optical disk in which the length of one wave of the wobbling groove is set to be the same for the entire disk and detecting diffracted light in the magneto-optical disk, Means for detecting the wobbling frequency based on the diffracted light, and means for comparing the detected wobbling frequency with a preset reference frequency to control the rotation of the magneto-optical disk so that the wobbling frequency becomes constant, A means for generating a master clock signal from the detected wobbling frequency, a means for modulating externally designated data based on the master clock signal, and a magnetic signal for the laser light irradiation area of the magneto-optical disk based on the modulated data. A magneto-optical recording apparatus comprising: a writing unit.