JPH10312597A - Disc recorder/reproducer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To extract a reproduction signal corresponding to a mark with high accuracy by preventing a pulse signal synchronized with a data clock signal from being superposed on the driving signal of a recording/reproducing light source for an interval where a mark having phase information is preformatted at the time of data recording. SOLUTION: At the time of writing a data, a record data Dr is fed to a magnetic head driver 16 and a magnetic head 15 generates a corresponding magnetic field for recording the record data Dr in the data region of a magnetooptic disc 11 in conjunction with a laser beam from an optical head 17. A laser driver 18 is normally fed with a data clock signal DCK from a data clock reproducer and a laser beam modulated by the record data Dr is further modulated by the data clock signal DCK. A system controller 51 interrupts data clock signal DCK supply to the laser driver 18 only during an interval where a clock mark us preformatted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk recording / reproducing apparatus using a disk in which marks having phase information are preformatted. Specifically, when recording data while modulating a data recording light source with a pulse signal synchronized with a data clock signal, only during a period in which a mark having phase information is preformatted, a reproduction mode is set or a specific pulse signal is set. In addition, a reproduction signal corresponding to the mark can be obtained without being affected by the data clock signal.

[0002]

2. Description of the Related Art Conventionally, it has been proposed to preformat a clock mark by groove wobble together with address information as a magneto-optical disk. In the magneto-optical disk device, a data clock signal for recording and reproducing data is obtained by using the reproduction signal of the clock mark.

FIG. 22A shows a reproduction signal S _CM of a clock mark.
The shows, the pulse signal P _CM indicating the timing of the reproduced signal S _CM than as shown in the figure B 0 cross point is formed, with reference to the pulse signal P _CM PLL (phase-lo
The data clock signal is obtained by a cked loop circuit.

The above-mentioned clock mark is formed while cutting the disk surface using a pair of cutting beams as shown in FIG. FIG. 7A shows the disk surface in the radial direction, in which land portions 12L and groove portions 12G are formed alternately.
The groove 12G is cut using a beam so that the groove 12G has a predetermined depth Da as shown in the sectional view of FIG.

[0005] One cutting end face 11a in the groove portion 12G is a flat face, while the other end face 1a.
1b is wobbled and its end face 11b has address information (indicated by a sine wave) ADM over a range of width Wa.
Also, a clock mark (a sine wave for one cycle) CM is formed continuously to the address information ADM.

As shown in FIG. 23A, a pair of laser beams Ba and Bb are used as cutting beams for performing groove wobble cutting. As shown, the cutting beams Ba and Bb scan the disk surface in a partially overlapping state, and in this example, a groove wobble is formed by the first cutting beam Ba.

[0007]

By the way, as a data recording method, an optical magnetic field modulation method and an optical modulation method are well known. Recently, when irradiating a disk with a laser beam in synchronization with recording data, a switching method (pulse modulation) in which the laser beam is turned on / off by a data clock signal formed from a reproduction signal SCM from a clock mark CM during this beam irradiation period. Method) is adopted.

Since the beam is always turned on and off by the data clock signal during the data recording period, the reproduced signal SCM obtained during the clock mark preformatting period is obtained.
This data clock signal is also output in a superimposed state (FIG. 23C). In order to form the pulse signal PCM shown in FIG. 22B from the reproduction signal SCM, it is necessary to remove the data clock signal from the reproduction signal SCM by filtering. Then, since the high-frequency component in the reproduced signal SCM is lost, the reproduced signal SCM becomes as shown in FIG. 22D, which may make it impossible to accurately detect the zero cross point of the reproduced signal SCM.

In view of the above, the present invention solves such a conventional problem, and provides a disk recording / reproducing apparatus capable of obtaining a reproduction signal corresponding to a mark without being affected by a data clock signal. Things.

[0010]

Means for Solving the Problems Claim 1 according to the present invention.
In the disk recording / reproducing apparatus described in the above, in a disk recording / reproducing apparatus using a disk in which marks having phase information are preformatted, a data recording / reproducing light source is driven by a driving signal in which a pulse signal synchronized with a data clock signal is superimposed In addition, the superimposition of the pulse signal is interrupted only during the preformatted period during data recording, and the light source is driven in the reproduction power mode.

According to a second aspect of the present invention, there is provided a disk recording / reproducing apparatus using a disk in which a mark having phase information is preformatted, wherein a drive signal in which a pulse signal synchronized with a data clock signal is superimposed is used. The recording / reproducing light source is driven, and a signal having a frequency sufficiently higher than the pulse signal is superimposed instead of the pulse signal only during a period in which the mark is preformatted during data recording. .

According to a fourth aspect of the present invention, there is provided a data recording / reproducing apparatus using a disk in which a mark having phase information is pre-formatted using a drive signal in which a pulse signal synchronized with a data clock signal is superimposed. The recording / reproducing light source is driven, and a signal having a frequency several times higher than that of the pulse signal is superimposed instead of the pulse signal only during a period in which the mark is preformatted during data recording. I do.

According to the first aspect of the present invention, the laser beam is driven by the reproducing power during the clock mark preformatting period even in the data recording mode. At that time, switching of the laser beam by the data clock signal is not performed. Thus, a reproduced signal of a clock mark that does not include the data clock signal is obtained.
Therefore, the zero cross point can be accurately extracted from the reproduced signal.

According to the second aspect of the present invention, the laser beam is switched at a frequency sufficiently higher than the data clock signal at least during the clock mark preformat period. Since the frequency to be superimposed is a high frequency, this harmonic signal can be separated without being affected by the frequency characteristics of the reproduced signal. Therefore, the zero cross point can be accurately extracted from the reproduced signal.

According to the present invention, the laser beam is switched at a frequency several times higher than the data clock signal during the clock mark preformat period. If such a frequency relationship is selected, the superimposed signal can be separated without being affected by the frequency characteristics of the reproduced signal.
Therefore, the zero cross point can be accurately extracted from the reproduced signal.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A case where an embodiment of a disk recording / reproducing apparatus according to the present invention is applied to a magneto-optical disk apparatus will be described below in detail with reference to the drawings.

First, a magneto-optical disk device applicable to the present invention and a magneto-optical disk 11 used in the device will be described.

FIG. 11 shows the layout of the sectors of the magneto-optical disk 11. Tracks 0 to n are spirally formed on the magneto-optical disk 11 from the inner circumference toward the outer circumference.
m sectors are included.

FIG. 12 shows a sector (wamble address frame) format. Magneto-optical disk 11
As described above, the groove portions 12G and the land portions 12L are alternately formed in the radial direction as described above, and data is recorded in one or both of the groove portions 12G and the land portions 12L.

As shown in FIG. 12A, one side of the groove portion 12G has, for example, address information AD after biphase modulation.
It is in a state of wobbling according to M. In this case, the address information ADM is frequency-modulated (FM), and the groove 12G is wobbled so as to correspond to the modulated signal. That is, the modulated signal is recorded as a groove wobble. The groove 1
Since one side of the 2G is wobbled, one side of the land 12L is also wobbled in accordance with the address information ADM.

As shown in FIG. 13, the number of groove wobbles per bit (1 bit of biphase) of the address information ADM is four when "1" and three when "0". . Moreover, the amplitude of the groove wobble is changed in accordance with the frequency of the signal after modulation, and as shown in the enlarged view of FIG.
The inclination at the 0 cross point of the groove wobble corresponding to the joint between “1” and “0” of DM is not changed.

Here, the groove wobble in the period of one sector (one wobble address frame) has, for example, 48-bit data before bi-phase modulation. The 48-bit data is composed of 4-bit synchronization signal data, 24-bit frame address data, 6-bit reserved bits, and 14-bit CRC (cyclic redundancy check) code, as shown in FIG. 12B. .

As shown in FIG. 12C, one sector is composed of, for example, 24 segments. At the boundary position of each segment, as shown in FIG. 12A, a clock mark CM is multiplexed with a groove wobble and preformatted. Then, as shown in FIG. 12D,
A 100-byte data area is provided in each segment, and a 10-byte fixed pattern area is provided corresponding to the boundary position of each segment. At the time of writing data, NRZI data is recorded in the data area as described later, but a 2T fixed pattern signal synchronized with the NRZI data is recorded in the fixed pattern area (T
Is the data bit interval).

As a preformat device for preformatting the address information ADM and the clock mark CM, a preformat device 10 as shown in FIG.
0 can be used. The clock mark CM can be a sine wave shaped wobble mark or irregular mark,
The example described below is a case where the clock mark CM is formed by the latter uneven mark.

The preformat apparatus 100 is provided with a light source 101 for cutting as shown in FIG.
As the light source 101, helium-cadmium (He-C
d) A laser light source or the like can be used.

The cutting beam (laser) emitted from the light source 101 is split into two optical paths by a half mirror 102, one beam Ba is directly supplied to a beam on / off means 104, and the other beam Bb is passed through a mirror 103. It is supplied to on / off means 105.

The beam on / off means 104 and 105 are for controlling the emission and stop of the beam.
In this example, an electro-optic effect modulator EOM (Erectro Optica
l Modurator) is used. These beam on / off means 104 and 105 are used as beam on / off control means 10.
The control means 106 is controlled based on the control signals Ca and Cb from the controller 6, and the controller 107 controls the control signal output timing and the like.

The beam wobbles of the cutting beams Ba and Bb whose emission states are controlled are controlled by beam wobble means 111 and 112. Beam wobble means 111 and 112 are provided by an acoustic effect modulator AOM (Acosti).
c Optical Modurator) and the like, and these are control signals F from the beam wobble control means 113.
The wobble amount is controlled by a and Fb. actually,
The wobble amount is controlled by the frequency of the control signals Fa and Fb. The wobble direction is controlled by the polarities of the control signals Fa and Fb. When the control signal is given by a triangular wave, the wobble locus becomes a triangular wave, and when the control signal is given by a sine wave, the wobble locus becomes a sine wave.

Beams ba and B whose wobble state is controlled
b is input to the optical means 115 and optically coupled so as to be in the state shown in FIG. 23A. Therefore, a pair of prisms 116 and 117 are prepared,
6, 117, the pair of beams Ba and Bb are combined. Then, as shown in FIG. 23A, the beams are combined so as to partially overlap each other. However, even when one beam Ba is wobbled by the address information ADM, the beam Ba is combined with the other beam Bb so as not to hit the scanning trajectory. The amount of overlap is controlled.

The optically coupled beam is applied to the surface of the disk 11 via the objective lens 118, and
The formation of G and the formation of groove wobbles (both disc cutting) are performed. The beam irradiation position on the disk 11 is detected by the position detecting means 119, and the detection output is supplied to the controller 107, whereby the beam irradiation position and the like are controlled.

The clock mark CM is formed by controlling the cutting state of the disk 11. Assuming that cutting is performed on the disk 11 when the beam is on, the beam irradiation on the disk 11 is stopped when the beam is off, so that the cutting of the disk 11 is not performed. Therefore, as shown in FIGS. 7A to 7C, the first cutting beam Ba and the second cutting beam B are separated from the zero cross point of the clock mark CM.
The on / off state with b is switched.

In the example shown in the figure, the first cutting beam Ba is turned off from the predetermined position immediately before the zero cross point to the zero cross point, and then the second cutting beam Ba is turned off until the predetermined position elapses from the zero cross point. The beam Bb is turned off. Therefore, the scanning trajectory of the beams Ba and Bb is shown in FIG.
become that way. In the same figure, the solid line or the chain line shows the part cut by the beam.

As a result, FIG.
A land portion 12L and a groove portion 12G are formed as shown in FIG. Paying attention to the groove portion 12G, the upper end face 1
Reference numeral 1a denotes an end surface on one side on which groove wobbling is performed, and a lower end surface 11b is a flat surface. When the beam Ba is turned off on the upper end surface 11a, the protrusion 4a remains inside the groove portion 12G during that period. When the beam Bb is turned off even in the lower end surface 3b, the projection 4b remains inside the groove portion 12G during that period.

That is, while the groove wobble is formed only by the first cutting beam Ba, the clock mark CM is formed by the two cutting beams Ba and Bb.
Therefore, the clock mark CM is formed on both end surfaces 11a and 11b of the groove portion 12G. One end face 11 of groove portion 12G
Since b is also the end face of the land 11L, the clock mark CM is formed using both end faces of the land 12L.

As a result, the clock mark projections 4a, 4a
Considering mainly b, the land 12L and the groove 1
In 2G, the projecting directions of the clock mark projections 4a and 4b are opposite. Therefore, focusing on the land portion 12L, the protrusion 4a due to the beam Ba protrudes outside the land 12L, and the protrusion 4a due to the beam Bb.
b protrudes outside the land portion 12L.

Each of the projections 4a and 4b formed by the beams Ba and Bb has a steep end face shape. As a result, the projection 4a has an off end face 4a 'side and the projection 4b has an on end face 4b' side. Matches exactly.

When the clock mark CM is reproduced by the reproduction beam PPB as shown in FIG. 8A, a signal as shown in FIG. B is obtained. This corresponds to the portion Pu on the scanning locus 5 in FIG.
When the difference Pu-Pd (push-pull signal) between the signal of the lower part Pd and the signal of the lower part Pd is taken, the difference becomes larger by the protrusions 4a and 4b when scanning the land 12L,
Moreover, since the polarities are opposite, a signal SCM (= SL) is obtained as shown by the solid line in FIG. This reproduced signal SCM has a steep level change at the obtained 0 cross point.

On the other hand, when scanning the groove 12G, the relationship between the projections 4a and 4b is reversed.
The reproduction signal SCM (= S
G). The level change at the zero cross point is as steep as in the previous case.

If both reproduction signals SL and SG are formed by reference signals REF1 and REF2 of the same level, the reproduction pulse signal P of the clock mark CM as shown in FIGS.
CM is obtained.

FIG. 8C shows a reproduced pulse signal PCM when scanning the land 12L, and FIG.
Since it is a reproduction pulse signal PCM when scanning 2G, it is easy to determine whether the beam PPB for data recording / reproduction is on the land 12L or on the groove 12G by the difference in these polarities. The result can be used for the servo system of the optical pickup as described later.

In the examples of FIGS. 7 and 8, the beams Ba, B
b, which is formed by turning on and off b.
Since the direction of 4b is opposite between the land 12L and the groove 12G, the land 12L is apparently thicker (wider) than the groove 12G. As a result, the levels of the reproduced signals SL and SG obtained also differ (see FIG. 8B).

This is because the beams Ba and Bb as shown in FIG.
This is because the clock mark CM is formed only by turning on / off the clock mark CM. To eliminate this, for example, as shown in FIG. 9A, the second cutting beam Bb may be shifted (fixed wobble) to the land portion 12L at least during the off period of the first cutting beam Ba. The shift processing of the beam Ba is performed by the wobble means 112 shown in FIG.

Thus, the pitch Wa on the groove portion 12G during the off period of the beam Ba and the land portion 12L
The upper pitch Wb matches. As a result, the level difference between the reproduced signals SL and SG can be corrected as shown in FIG. However, the level difference between the minus side and the plus side is not eliminated. The example shown in FIG. 10 is such that this level difference can be corrected.

In this case, both beams Ba and Bb are shifted (quantitative wobble) in the opposite directions both before and after the on / off switching timing of the beams Ba and Bb. Therefore, an on / off signal Ca shown in FIG. 10A is given to the control means 105 to the first cutting beam Ba, and the wobble means 112
The wobble control signal Fa shown in FIG.

Similarly, the second cutting beam Bb
10C is supplied to the control means 104, and the wobble control signal Fb shown in FIG. The width of the wobble control signals Fa and Fb is arbitrary. In this example, it is set to approximately 1/2 of the beam off period.

By providing such wobble control signals Fa and Fb, the beams Ba and Bb are wobbled in directions opposite to each other. Therefore, for example, the groove portion 12G is cut as shown by oblique lines in FIG. 10E. . As a result, the land portion 12L and the groove portion 1
The relationship with 2G is as shown in Fig. F, and the width of the land 12L and the width of the groove 12G are not irregular. Therefore, the level difference between the reproduced signals SL and SG from the clock mark CM thus formed is completely eliminated as shown in FIG.

Although FIG. 10 shows a triangular wave as the wobble control signals Fa and Fb, a sine wave or another waveform may be used. The width and level of the triangular wave, that is, the amount of wobble is also an example. For example, if the amount of wobble is increased, the output levels of the reproduced signals SL and SG can be increased accordingly.

Next, an embodiment of a magneto-optical disk drive 10 to which the present invention shown in FIG. 1 is applied will be described.

The disk device 10 has a spindle motor 13 for driving the magneto-optical disk 11 to rotate. The magneto-optical disk 11 is driven to rotate at a constant angular velocity during recording and reproduction. Spindle motor 13
A frequency generator 14 for detecting the rotation speed is attached to the rotating shaft.

The disk drive 10 includes a magnetic head 15 for generating an external magnetic field, a magnetic head driver 16 for controlling the generation of a magnetic field of the magnetic head 15, a semiconductor laser,
Optical head 17 composed of an objective lens, a photodetector, etc.
And a laser driver 18 for controlling the light emission of the semiconductor laser of the optical head 17. Magnetic head 15
And the optical head 17 are arranged to face each other with the magneto-optical disk 11 therebetween. The laser driver 18 is provided with a D / A converter 19 by a servo controller 41 described later.
The laser power control signal _SPC is supplied via the optical head 17, and the power of the laser beam output from the semiconductor laser of the optical head 17 is controlled so as to be optimal during recording and reproduction.

To set the optimum power Pw at the time of recording and to set the optimum power Pr (Pw> Pr) at the time of reproduction, a power control signal corresponding to the recording / reproduction mode is given to the servo controller 41 from the system controller 51 described later. Can be

At the time of data writing (at the time of recording), the recording data Dr and the fixed pattern signal _SFP are supplied to the magnetic head driver 16 as described later, and the magnetic head 15 responds to the recording data Dr and the fixed pattern signal _SFP . A magnetic field is generated, recording data Dr is recorded in the data area of the magneto-optical disk 11 in cooperation with the laser beam from the optical head 17, and a fixed pattern area corresponding to the data area where the recording data Dr is recorded. , A fixed pattern signal _SFP is recorded.

When recording the recording data Dr, it is common practice to further modulate the laser beam modulated by the recording data Dr with a data clock signal DCK obtained from a data clock reproducing unit 70. For this purpose, the data clock signal DCK reproduced by the data clock reproducer 70 is supplied to the laser driver 18.

Even during data recording, the disc 1
1, the address information ADM and the clock mark CM are read. When the laser beam is pulse-modulated, the reproduction signal SCM of the clock mark CM is also superimposed with the data clock signal DCK as shown in FIG. 22C. If filtering is performed to remove the data clock signal DCK, the high-frequency component of the reproduction signal SCM is lost, so that the waveform of the reproduction signal SCM, particularly at the zero cross point, becomes blunt. This makes it susceptible to jitter, making it impossible to accurately record and reproduce data.

Therefore, even in the recording mode, FIGS.
As shown in (5), the laser driver 18 is controlled to the reproduction mode especially during the period PB in which the clock mark CM is pre-formatted, and during this period PB, the modulation of the laser beam by the data clock signal DCK is interrupted.

Therefore, during the clock mark preformat period PB, the semiconductor laser uses the reproduction power (low power) P
A control signal (FIG. 2C) driven by R is supplied from the system controller 51 to the servo controller 41. At the same time, a similar control signal is applied to the laser driver 18 to interrupt the modulation of the laser beam by the data clock signal DCK. As a result, the laser beam is modulated by the data clock signal DCK only in the section REC excluding the clock mark preformat period PB as shown in FIG. 8B.

In this manner, since the clock mark preformat period PB is not modulated by the data clock signal DCK, the clock mark reproduction signal SCM outputs the clock mark itself as shown in FIG. 8A. The zero cross point can be extracted with high precision from the mark reproduction signal SCM.

As means for preventing the data clock signal DCK from being superimposed on the reproduced signal SCM of the clock mark CM and being output, a means shown in FIG. 3 or FIG. 4 in addition to FIG. 1 is employed. Can also.

FIG. 3 shows that during the clock mark preformat period PB, instead of driving the semiconductor laser with the recording power PW, the clock mark preformat period PB is used.
During B, the harmonic signal H is used instead of the data clock signal DCK.
F is superimposed on the laser drive signal (not shown). A frequency band capable of reducing the noise of the semiconductor laser is selected as the harmonic signal HF, and a frequency of about 500 MHz is used as the frequency as is well known.

Therefore, an oscillator 90 for oscillating such a harmonic signal HF is provided, and the control signal P shown in FIG.
Clock mark preformat period PB according to CTL
Only the oscillation state is controlled. This harmonic signal HF is supplied to the laser driver 18. Then, the laser power remains at the recording power PW (FIG. 2E). Therefore, the semiconductor laser is driven by a harmonic signal as shown in FIG.

The reproduced signal SCM of the clock mark CM is output in a state where the harmonic signal HF is superimposed. However, since the harmonic signal HF exists in a band much higher than the frequency band of the reproduced signal SCM, the MTF is output. (Modulation Transfer Fu
nction) does not affect the frequency characteristics of the obtained reproduction signal SCM at all even if the reproduction signal band itself determined by the nction is used as the cutoff frequency. Therefore, the zero cross point can be detected with higher accuracy than the reproduced signal SCM.

Clock mark preformat period PB
During the operation, the laser power may be controlled to the reproduction power state.
The laser beam may be switched by this harmonic signal instead of the data clock signal DCK during data recording.

FIG. 4 shows a specific example in which pulse modulation is performed at a frequency several times the data clock signal DCK, for example, twice the frequency during the clock mark preformat period PB, and the frequency is doubled using the data clock signal DCK. Circuit 9
2 is provided, a pulse signal from this is supplied to the laser driver 18, and a modulation control signal PPR shown in FIG. 2G is supplied from the system controller 51. Then, a control signal for the recording power PW shown in FIG. As a result, as shown in FIG. 8I, the clock mark preformat period PB
In the middle, the laser beam is driven by a double pulse signal 2DCK.

The reproduction signal SCM of the clock mark CM is output in a state modulated by the pulse signal 2DCK. However, since the pulse signal 2DCK exists in a band higher than the frequency band of the reproduction signal SCM, the reproduction signal determined by the MTF. By setting the band itself as the cutoff frequency,
The reproduced signal SCM can be separated without affecting the frequency characteristics of the obtained reproduced signal SCM at all. Therefore, even with the configuration of FIG. 4, the zero cross point can be detected with higher accuracy than the reproduced signal SCM.

In the case of FIG. 4, since it is a doubler circuit 92 as compared with FIG. 3, it is cheaper than the oscillator 90, and the power control for the semiconductor laser is simpler than in FIG. Become. 2A during the clock mark preformat period PB even in the data reproduction mode.
Controls such as F and I can be performed.

FIG. 14 shows the configuration of the optical system of the optical head 17. The optical head 17 includes a semiconductor laser 31 for obtaining a laser beam LB, a collimator lens 32 for shaping the laser beam LB output from the semiconductor laser 31 into a parallel light from a divergent light, and a laser light for transmitting a laser beam. A beam splitter 33 for separating the reflected light into two, a rising mirror 34 for changing the optical path of the laser beam, and a laser beam LB for irradiating the recording surface (recording film) of the magneto-optical disk 11 with the laser beam LB. And an objective lens 35.

The optical head 17 has a Wollaston prism (polarizing surface) for separating the laser beam reflected by the reflecting surface 33b of the beam splitter 33 and emitted to the outside into three types of laser beams depending on the polarization direction. A detection prism) 36, a condenser lens 37 for condensing three types of laser beams (parallel light) output from the Wollaston prism 36, and three types of laser beams emitted from the condenser lens 37 Photodetector 39 to which light is irradiated, condenser lens 37 and photodetector 3
9 and a multi-lens 38 disposed between them.

The multi lens 39 is composed of a combination of a concave lens and a cylindrical lens. The use of the cylindrical lens is for obtaining the focus error signal by a well-known astigmatism method. As shown in FIG. 15, the photodetector 39 includes a four-division photodiode unit 39m and two photodiode units 39i and 39j.

FIG. 16 shows a configuration example of the Wollaston prism 36. This prism 36 is a uniaxial crystal,
For example, right angle prisms 36a and 36b made of quartz are joined. In this case, the optical axis Axb of the prism 36b is set to be inclined by 45 ° with respect to the optical axis Axa of the prism 36a.

In such a configuration, the quartz has two different refractive indices in relation to the plane of polarization of the incident light.
Therefore, the prism 36a has 45
When the linearly polarized light La having a polarization plane Ppo inclined by ゜ is incident, the prism 36a has an optical axis Axa as shown in FIG.
Is separated into a polarization component Lb1 having a polarization plane perpendicular to the optical axis and a polarization component Lb2 having a polarization plane parallel to the optical axis Axa. Further, in the prism 36b, the polarization component Lb1 is separated into a polarization component Lc1 having a polarization plane parallel to the optical axis Axb and a polarization component Lc2 having a polarization plane perpendicular to the optical axis Axb. A polarization component Lc3 having a plane of polarization parallel to and a polarization component L having a plane of polarization perpendicular to the optical axis Axb
Separated into c4.

Here, the polarization components Lc1 and Lc2 are
6a has a polarization plane perpendicular to the optical axis Axa, and the amount of each light is 1/4 of the linearly polarized light La. On the other hand, the polarization components Lc3 and Lc4 have a plane of polarization parallel to the optical axis Axa of the prism 36a, and the amount of each light is 1/4 that of the linearly polarized light La. And the polarization component Lc
2, Lc3 have the same exit angle from the prism 36b, and consequently the prism 36b, and thus the Wollaston prism 3
From No. 6, three laser beams Li, Lm and Lj are obtained separately.

The operation of the optical system of the optical head 17 shown in FIG. 14 will be described. The laser beam LB as divergent light emitted from the semiconductor laser 31 is shaped into parallel light by the collimator lens 32 and is incident on the beam splitter 33. The optical path of the laser beam transmitted through the multilayer film 33 a of the beam splitter 33 is changed at right angles by the rising mirror 34, and is irradiated on the recording surface of the magneto-optical disk 11 via the objective lens 35.

The laser beam reflected by the recording surface of the magneto-optical disk 11 is applied to the objective lens 35 and the mirror 34.
And is incident on the beam splitter 33. And
The laser beam Lr reflected by the multilayer film 33a of the beam splitter 33 is further reflected by the reflection surface 33b of the beam splitter 33, emitted to the outside, and incident on the Wollaston prism 36.

As described above, the laser beam Lr related to the reflection on the recording surface of the magneto-optical disk 11 is incident on the Wollaston prism 36.
The polarization plane is set so as to be inclined by 45 ° with respect to the optical axis Axa when there is no rotation (Kerr rotation) of the polarization plane on the recording surface (the polarization plane Ppo and the light of the linearly polarized light La in FIG. 16). See relationship with axis Axa). Accordingly, the linearly polarized light L
a, the Wollaston prism 3
6, three laser beams Li, Lm and Lj are separated from the laser beam Lr.

Here, the polarization plane of the laser beam Lr slightly rotates clockwise or counterclockwise according to the direction of magnetization of the recording film of the magneto-optical disk 11, and the laser beam Lr
A magnitude relationship is generated between the light amounts of i and Lj according to the direction of magnetization of the recording film of the magneto-optical disk 11. Therefore, a reproduction signal corresponding to magneto-optically recorded data (signal) can be obtained by detecting the light amounts of the laser beams Li and Lj and taking the difference. Note that the light amount of the laser beam Lm is constant even when the polarization plane of the laser beam Lr rotates.

As described above, the Wollaston prism 36
The three laser beams Li, Lm, Lj emitted from the laser beam enter a photodetector 39 via a condenser lens 37 and a multi-lens 38. As shown in FIG. 15, the laser beams Li and Li are applied to the photodiode units 39i, 39m and 39j constituting the photodetector 39, respectively.
Spots SPi, SPm, SPj are formed by Lm, Lj.

In this case, the four-division photodiode section 39
m, the detection signals of the four photodiodes Da to Dd are denoted by Sa to Sd, respectively.
When the detection signals of the photodiodes Di and Dj constituting 9i and 39j are Si and Sj, the following calculation is performed in the amplifier circuit unit (not shown) of the optical head 17, and the reproduction signal S _MO from the recording area is obtained. , A focus error signal S _FE and a push-pull signal S _{PP of the} astigmatism method are generated.

S _MO = Si−Sj S _FE = (Sa + Sc) − (Sb + Sd) S _PP = (Sa + Sb) − (Sc + Sd) Returning to FIG. 7, the disk device 10 is a CPU (central)
and a servo controller 41 having a processing unit. The optical head 1 is provided in the servo controller 41.
The focus error signal _SFE generated at 7 is supplied via the A / D converter 42. Also, the optical head 17
The push-pull signal S _PP generated by the tracking error signal _STE by the push-pull method and the wobble signal (FM) corresponding to the groove wobble of the magneto-optical disk 11
Signal) S _WB and clock mark C of magneto-optical disk 11
The clock mark reproduction signal S _CM corresponding to M is synthesized. The servo controller 41, the push-pull signal S _PP from the tracking error signal extracted by the low-pass filter 43 S _TE is supplied through an A / D converter 44. The servo controller 41 is further supplied with a frequency signal _SFG output from the frequency generator 14 described above.

The operation of the servo controller 41 is controlled by a system controller described later. The servo controller 41 controls an actuator 45 including a tracking coil, a focus coil, and a linear motor for moving the optical head 17 in a radial direction, and performs tracking and focus servo. Movement in the direction is controlled. Further, the spindle motor 13 is controlled by the servo controller 41, so that the magneto-optical disk 11 is controlled to rotate at a constant angular velocity during recording and reproduction as described above.

The push-pull signal SPP is further supplied to a polarity discriminating circuit 46, and reproduction signals SL and SG shown in FIG. 4B are generated from the push-pull signal SPP.
The discrimination signals GL and GG shown in FIGS. 4C and 4D are generated from SG. The discrimination signals GL and GG are the servo controller 41
It is determined whether the recording / reproducing beam PPB is on the land portion 12L or on the groove portion 12G based on its polarity.

Based on the result of this determination, the servo controller 41 selects whether to perform tracking servo for the land 12L or to perform tracking servo for the groove 12G. Then, based on the selected tracking servo (the polarity of the servo signal is different between the land portion and the groove portion), the beam is shifted to the land portion 12.
The actuator 45 is controlled by a tracking control signal from the servo controller 41 so as to track on L or on the groove portion 12G.

The disk device 10 includes a system controller 51 having a CPU and a data buffer 52.
(Small Computer System Interface) for sending and receiving data and commands to and from the host computer
rface) interface 53. The system controller 51 controls the entire system.

The disk device 10 performs an error correction code addition process on write data supplied from the host computer through the SCSI interface 53 and performs an error correction process on output data of a data demodulator described later. ECC (error correction)
code) circuit 54 and the write data to which the error correction code has been added by the ECC circuit 54.
to Zero Inverted) data and record data Dr
And a data modulator 55 for generating the above-described fixed pattern signal _SFP .

Further, the disk device 10 includes the optical head 1
7, an equalizer circuit 56 for compensating the frequency characteristics of the reproduced signal _SMO , an A / D converter 57 for converting an output signal of the equalizer circuit 56 into a digital signal, and an A / D converter 57 A data discriminator 58 for digitally performing data discrimination processing on the output data of the data discriminator to obtain reproduction data Dp;
And a data demodulator 59 for performing NRZI inverse conversion processing on the reproduction data Dp output from the decoder 8 to obtain read data. The data discriminator 58 includes a binarizing circuit, a Viterbi decoder, and the like.

Further, the disk device 10 includes the optical head 1
ADIP obtaining frame synchronization signal FD and the frame address data FAD from the wobble signal S _WB which is included in the push-pull signal S _PP produced in 7 (Address In Pre-g
and Roove) decoder 60, the push-pull signal S clock marks included in the _PP reproduced signal S _CM and the data clock regenerator 7 to obtain a data clock signal DCK from the reproduction signal S _MO corresponding to the fixed pattern region of the magneto-optical disc 11
0, a timing generator 90 for generating a timing signal necessary for each part of the system such as a read gate signal and a write gate signal using the frame synchronization signal FD, the frame address data FAD and the data clock signal DCK.
And The frame address data FAD is also supplied to the servo controller 41, and the data clock signal DCK is supplied to the A / D converter 57 as a sampling clock.

FIG. 9 shows the configuration of the ADIP decoder 60. The ADIP decoder 60 includes a band-pass filter 61 for extracting the wobble signal S _WB from the push-pull signal S _PP and a DC cut capacitor 62.
And the wobble signal S _WB is set as the threshold value = 0 and the pulse signal P _WB
And a comparator 63 for converting the

The ADIP decoder 60 has a PLL
(Phase-locked loop) circuit 64 and a voltage controlled oscillator 64a that constitutes a divider for the clock signal CK ₂₄ output from the voltage controlled oscillator 64a 1/24 frequency-divided 64
b and the pulse signal P _WB output from the comparator 63
And a phase comparator 64c for comparing the phase of the output signal of the frequency divider 64b with the output signal of the frequency divider 64b. The phase comparator 64c extracts the low-frequency component of the phase error signal output from the phase comparator 64c and supplies it to the voltage-controlled oscillator 64a. A low-pass filter 64d for obtaining a control signal.

The ADIP decoder 60 performs demodulation processing on the pulse signal P _WB output from the comparator 63 using the clock signal CK ₂₄ output from the voltage controlled oscillator 64a to obtain address information ADM. A clock signal A synchronized with the address information ADM
A decode processing circuit 67 for obtaining CK; a serial / parallel converter 68 for converting address information ADM output from the decode processing circuit 67 from serial data to parallel data using a clock signal ACK; A decoder 69 that performs synchronization detection, biphase demodulation processing, error detection processing, and the like on the output data of the device 68 in synchronization with the clock signal ACK to obtain a frame synchronization signal FD and frame address data FAD. ing.

Next, the ADIP decoder 60 shown in FIG.
Will be described. A wobble signal S _WB is extracted from the push-pull signal S _PP by a band pass filter 61. Then, the wobble signal S _WB is supplied to the comparator 63 via the capacitor 62 and is converted into a pulse signal P _WB . As described above, the address information ADM after the bi-phase modulation is frequency-modulated on the magneto-optical disk 11,
The modulated signal is recorded as a groove wobble. Therefore, the wobble signal _SWB , like the signal after frequency modulation, has the address information A as shown in FIG. 19A.
In correspondence with one bit of DM (one bit of biphase),
"1" has four waves, and "0" has three waves. Therefore, the pulse signal P _WB is obtained from the comparator 63 as shown in FIG. 19B. Note that the amplitude of the wobble signal _SWB is proportional to the amplitude of the groove wobble of the magneto-optical disk 11.

[0090] Also not described above, the frequency is fa of the wobble signal S _WB which corresponds to "1", when the frequency of the wobble signal S _WB which corresponds to "0" is fb, the oscillation frequency of the voltage controlled oscillator 64a Is set to change in the vicinity of a frequency that is a common multiple of fa and fb (= 6fa = 8fb). Therefore, the voltage-controlled oscillator 64a outputs the signal shown in FIG.
As shown in C, a clock signal CK ₂₄ having a frequency of fc = 6fa = 8fb, that is, a frequency 24 times the bi-phase bit frequency, and synchronized with the pulse signal P _WB is obtained. With reference to the clock signal CK ₂₄ , the pulse signal P _WB corresponding to the bi-phase 1 bit = “1” has a pattern (6T pattern) composed of “1” for three clocks and “0” for three clocks. The pulse signal P _WB corresponding to the bi-phase 1 bit = “0” has a pattern (8T pattern) composed of “1” for four clocks and “0” for four clocks.

The decoding processing circuit 67 outputs the pulse signal P _WB
When detected continuously three times more 8T pattern, clock signal ACK in synchronization with (shown in FIG. 19D) outputs "0" to this biphase 1 bit period, whereas 6T pattern from the pulse signal P _WB Is detected four times in succession, the next biphase 1 is synchronized with the clock signal ACK.
"1" is output during the bit period. That is, the decoding processing circuit 67 performs demodulation processing on the pulse signal P _WB , and the decoding processing circuit 67 outputs the clock signal AC
Along with K, address information ADM corresponding to the groove wobble is output in synchronization with the clock signal ACK (shown in FIG. 19E).

The address information ADM is converted into parallel data by a serial / parallel converter 68 and supplied to a decoder 69.
Synchronization detection, bi-phase demodulation processing, error detection processing, and the like are performed on the DM to obtain a frame synchronization signal FD and frame address data FAD. This allows
The decoder 69 outputs frame address data FAD obtained from the address information ADM together with the frame synchronization signal FD.

Unlike the above description, for example, when the 8T pattern is detected twice consecutively from the pulse signal P _WB , “0” is output in the next bi-phase 1-bit period in synchronization with the clock signal ACK. On the other hand, 6T from the pulse signal P _WB
When detecting a pattern three consecutive times, the clock signal AC
The decoding processing circuit 67 may be configured to output “1” in the next bi-phase 1-bit period in synchronization with K, for example, to enhance the resistance to defects.

FIG. 20 shows a data clock regenerator 70.
Is shown. This data clock regenerator 70
_Are a band pass filter 71 for extracting a clock mark reproduction signal S _CM from the push-pull signal S _PP , a DC cut capacitor 72, and a pulse signal P indicating the timing of the 0 cross point from the clock mark reproduction signal S _{CM. cm}
And an edge detector 73 that obtains

[0095] Moreover, the data clock regenerator 70 comprises a capacitor 74 for cutting a DC component of the reproduced signal S _MO, a comparator 75 for converting the reproduced signal S _MO to the pulse signal P _MO as a threshold = 0, this pulse signal P _The fixed pattern gate signal S supplied from the _MO from the timing generator 90
And an AND circuit 76 for using G to gate a pulse signal P _FP corresponding to the reproduction signal S _MO in the fixed pattern area of the magneto-optical disk 11. In this case, as shown in FIG. 12E, the fixed pattern gate signal SG is "1" in the reproduced signal S _{period MO} is obtained in the fixed pattern region,
In other periods, it is "0".

Further, the data clock regenerator 70 has a PL
A voltage controlled oscillator 77 constituting L circuit, a frequency divider 78 for dividing a data clock signal DCK output from the voltage controlled oscillator 77 to 1 / N, the pulse signal P _CM output from the edge detector 73 And a low-pass filter 80 for extracting the low-frequency component of the phase error signal output from the phase comparator 79.

The data clock regenerator 70 outputs the pulse signal _PFP output from the AND circuit 76 and the frequency divider 78
Phase comparator 81 for comparing the phase with the output signal of
And a high-pass filter 82 for extracting a high-frequency component of the phase error signal output from the phase comparator 81, an output signal of the low-pass filter 80, and an output signal of the high-pass filter 82 supplied via the connection switch 83. And an adder 84 for obtaining a control signal to be supplied to the voltage controlled oscillator 77. The connection switch 83 is supplied with a switch control signal SW from the system controller 51. As a result, the connection switch 83 is turned off at the time of data writing (at the time of recording) and turned on at the time of data reading (at the time of reproduction).

Next, the operation of the data clock regenerator 70 shown in FIG. 20 will be described. A clock mark reproduction signal S _CM (shown in FIG. 21A) is extracted from the push-pull signal S _PP , and this clock mark reproduction signal S _CM is
Is supplied to the edge detector 73 via Then, the pulse signal P _CM of the edge detector 73 shows a zero cross point timing of the clock mark reproduction signal S _CM (shown in FIG. 22B) is obtained.

The reproduction signal S _MO output from the optical head 17 (see FIG. 1) is supplied to a comparator 75 via a capacitor 74 and converted into a pulse signal P _MO .
The pulse signal P _{MO is} output by the AND circuit 76.
Thus, a pulse signal _PFP corresponding to the reproduction signal _SMO in the fixed pattern area of the magneto-optical disk 11 is extracted.

At the time of data writing (at the time of recording), the connection switch 83 is turned off, so that the voltage-controlled oscillator 77, the frequency divider 78, the phase comparator 79, and the low-pass filter 80 constitute a PLL circuit. , The low-frequency component of the phase error signal output from the phase comparator 79 is supplied to the voltage-controlled oscillator 77 as a control signal.
Therefore, from the voltage controlled oscillator 77, a data clock signal DCK whose phase is controlled by the low-frequency component of the phase information held by the clock mark reproduction signal S _CM is obtained.

At the time of reading data (during reproduction),
Since the connection switch 83 is turned on, the PLL is controlled by the voltage controlled oscillator 77, the frequency divider 78, the phase comparators 79 and 81, the low-pass filter 80, and the high-pass filter.
The voltage control oscillator 77 includes a phase comparator 7
An addition signal of the low-frequency component of the phase error signal output from 9 and the high-frequency component of the phase error signal output from the phase comparator 81 is supplied as a control signal. Therefore, from the voltage controlled oscillator 77, a clock mark reproduction signal S _CM has phase information of the low-frequency component and fixed pattern area data clock signal whose phase is controlled by the high-frequency component of the phase information reproduced signal S _MO has the DCK is obtained. FIG. 21E
Indicates a data clock signal DCK.

Next, the magneto-optical disk drive 10 shown in FIG.
Will be described. When a data write command is supplied from the host computer to the system controller 51, a data write process (recording process) is performed.
In this case, the ECC circuit 54 performs processing for adding an error correction code to the write data received from the host computer and stored in the data buffer 52 by the SCSI interface 53, and furthermore, the data modulator 55
Performs conversion processing to NRZI data. Then, the recording data Dr and the fixed pattern signal _SFP are supplied from the data modulator 55 to the magnetic head driver 16, and the recording data Dr is recorded in the data area as the target position of the magneto-optical disk 11, and the recording data Dr is A fixed pattern signal _SFP is recorded in a fixed pattern area corresponding to the data area to be recorded.

When a data read command is supplied from the host computer to the system controller 51, data read processing (reproduction processing) is performed.
In this case, the reproduction signal _SMO is obtained from the data area as the target position of the magneto-optical disk 11 and the fixed pattern area corresponding to the data area. This reproduced signal S
_The frequency characteristic of _MO is compensated for by an equalizer circuit 56, and A /
The data is converted into a digital signal using the data clock signal DCK by the D converter 57, and then the data
In step 8, the data is identified, and reproduced data Dp is obtained. Then, the reproduced data Dp is subjected to the NRZI inverse conversion by the data demodulator 59, and the ECC circuit 5
In step 4, an error correction process is performed to obtain read data. The read data is stored in the data buffer 52.
And then transmitted to the host computer via the SCSI interface 53 at a predetermined timing.

In the data writing process and the data reading process, the magnetic head 51 and the optical head 17 are used.
Is controlled by the servo controller 41 to seek to the target position. In this case, the seek operation is performed with reference to the frame address data FAD output from the ADIP decoder 60. At this time, the servo controller 41 determines whether the laser beam is on the land 12L or the groove 12G based on the output signals GL and GG of the polarity discriminating circuit 46.

At the time of writing data (at the time of recording),
The data clock regenerator 70 from the clock mark reproduction signal S _CM has data clock signal DCK whose phase is controlled by the low-frequency component of the phase information is obtained, a laser beam is pulse-modulated in synchronization with the data clock signal DCK At the same time, data write processing is performed. During the clock mark preformat period PB, the reproduction mode is controlled, and the pulse lighting by the data clock signal DCK is interrupted.

On the other hand, when reading data (during reproduction),
Low-frequency component and fixed pattern area of the reproduced signal high-frequency component and a data clock signal DCK whose phase is controlled by the phase information held by the S _MO is obtained of the phase information from the data clock regenerator 70 having a clock mark reproduction signal S _CM The data reading process is performed in synchronization with the data clock signal DCK.

As described above, in this embodiment, the on / off control of the cutting beam is performed to control the clock mark C.
Since M is formed on the disk 11, the clock mark CM can be formed on the disk 11 with high accuracy. Therefore, even when the level of the clock mark reproduction signal SCM is low, the zero cross point can be detected with high accuracy.

[0108] In the magneto-optical disk apparatus using the disk 11, a data read (reproduction), reproduction of the low-frequency component and fixed pattern area of the phase information from the data clock regenerator 70 having a clock mark reproduction signal S _CM signal S _MO is intended to obtain the data clock signal DCK whose phase is controlled by the high-frequency component of the phase information held by the (2
0 See), even if poor S / N of the clock mark reproduction signal S _CM can obtain a clock signal synchronized with a high accuracy in the reproduced data, it is possible to improve the accuracy of the data read process.

Further, the amplitude of the groove wobble of the magneto-optical disk 11 is changed in accordance with the frequency of the signal after modulation, and the amplitude of the groove wobble corresponding to the junction of "1" and "0" of the address information ADM. The inclination at the zero cross point does not change (see FIG. 13). Therefore, it is possible to reduce the jitter in the time axis direction of the corresponding wobble signal S _WB at the junction of the "1" and "0" of the address information ADM, to obtain address information ADM good in ADIP decoder 60 (see FIG. 18) Can be. As described above, in the present embodiment, the wave numbers of the groove wobbles corresponding to “1” and “0” of the address information ADM are integers, respectively, and correspond to “1” and “0” of the address information ADM. This is particularly effective because the joints of the groove wobbles are all zero cross points.

[0110] Further, the ADIP decoder 60, a clock having a frequency fa of the wobble signal S _WB which corresponds to the data of "1" and "0" of the address information ADM, frequency of common multiple of fb fc (= 6fa = 8fb) The address information ADM is obtained by a demodulation process using the signal CK ₂₄ (see FIG. 18). Therefore, if the PLL circuit is 1
There is an advantage that the configuration can be realized only by having a system and the configuration of the ADIP decoder 60 is simplified. In this case, the address information AD
The wave numbers of the groove wobbles corresponding to “1” and “0” of M are integers, respectively.
Since the pulse signal P _WB output from the comparator 63 always corresponds to the “1” and “0” data, the demodulation processing using the clock signal CK ₂₄ in the decode processing circuit 67 is facilitated. Can be done.

Although the wobbling state is shown only on one side of the groove portion 12G of the magneto-optical disk 11, the wobbling state may be on both sides of the groove portion 12G.

Although the clock mark CM is preformatted on the wobbled side of the groove portion 12G, the clock mark CM may be preformatted on the non-wobbled side. The CM may be pre-formatted.

"1" and "0" of address information ADM
The wave number of the groove wobble corresponding to is "4",
Although “3” is used, the present invention is not limited to this and may not be an integer.

Although the fixed pattern area of the recording area is provided in one-to-one correspondence with the recording position of the clock mark CM, it is not always necessary to make it correspond. For example, the number of fixed pattern areas may be smaller than the number of clock marks CM.

In the fixed pattern area of the magneto-optical disk 11, a fixed pattern signal of 2T synchronized with the NRZI data is recorded, but a fixed pattern signal of 1T or 3T or more may be recorded. . However, the pattern interval becomes shorter, smaller amplitude of the reproduced signal S _MO by MTF, it becomes the S / N is deteriorated.
Conversely, when the pattern interval becomes longer, in order to obtain the same number of edges for phase comparison, it is necessary to increase the fixed pattern area, and the data area in which data is recorded becomes narrower.

[0116] In ADIP decoder 60, a clock signal having a frequency fa of the wobble signal S _WB which correspond to the data of "1" and "0" of the address information ADM, frequency of common multiple of fb fc (= 6fa = 8fb) CK _{twenty four}
Although the demodulation process using is performed, a similar demodulation process can be performed using a clock signal having a frequency that is another common multiple of the frequencies fa and fb.

Although the phase information is obtained from the reproduction signal of the clock mark CM preformatted on the magneto-optical disk 11, the present invention uses the phase information from the reproduction signal of the clock pit preformatted by the sample servo method. The same applies to what you get.

[0118]

As described above, the inventions according to the first, second and fourth aspects of the present invention can be applied to a mark having phase information without being affected by a data clock signal during a preformatted period. A corresponding reproduction signal is obtained.

According to this, the zero cross point can be accurately extracted from the reproduced signal corresponding to the mark without being affected by the data clock signal.

[Brief description of the drawings]

FIG. 1 is a block diagram (part 1) showing a configuration of a magneto-optical disk device showing an example of a disk recording / reproducing device according to the present invention.

FIG. 2 is a waveform chart for explaining the operation.

FIG. 3 is a block diagram (part 2) showing a configuration of a magneto-optical disk device showing an example of a disk recording / reproducing device according to the present invention;

FIG. 4 is a block diagram (part 3) showing a configuration of a magneto-optical disk device showing an example of a disk recording / reproducing device according to the present invention;

FIG. 5 is a system diagram of a main part of a preformat device suitable for use in preformatting a disk used in the present invention.

FIG. 6 is a waveform diagram showing an on / off relationship between a clock mark and a cutting beam.

FIG. 7 is a conceptual diagram showing ON / OFF of a cutting beam.

FIG. 8 is a diagram showing a relationship between a clock mark (part 1) formed by turning on and off a cutting beam, a reproduction signal, and a polarity discrimination signal.

FIG. 9 is a conceptual diagram showing another example (part 2) of the on / off relationship of the cutting beam.

FIG. 10 is a waveform chart showing a timing chart illustrating another example (part 3) of the on-off relationship of the cutting beam.

FIG. 11 is a diagram showing a layout of sectors of a magneto-optical disk.

FIG. 12 is a diagram for explaining a sector (wobble address frame) format.

FIG. 13 is a diagram illustrating a configuration example of a groove wobble.

FIG. 14 is a perspective view showing an optical system of the optical head.

FIG. 15 is a diagram showing a configuration of a photodetector constituting an optical system of the optical head and a spot formed thereon.

FIG. 16 is a diagram showing a configuration example of a Wollaston prism constituting the optical system of the optical head.

FIG. 17 is a diagram showing a state of separation of light rays by a Wollaston prism.

FIG. 18 is a block diagram illustrating a configuration of an ADIP decoder.

FIG. 19 is a timing chart for explaining the operation of the ADIP decoder.

FIG. 20 is a block diagram showing a configuration of a data clock regenerator.

FIG. 21 is a timing chart for explaining the operation of the data clock regenerator.

FIG. 22 is a diagram showing a reproduction signal and the like of a clock mark in a conventional magneto-optical disk device.

FIG. 23 is a diagram showing a relationship between clock mark forming cutting beams.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Magneto-optical disk device, 11 ... Magneto-optical disk, 12G ... Groove part, 12L ... Land part, 15 ... Magnetic head for generating an external magnetic field, 16 ...
・ Magnetic head driver, 17 ・ ・ ・ Optical head, 18 ・
..Laser drivers, 41 ... servo controllers,
51: system controller, 52: data buffer, 53: SCSI interface, 54 ...
・ ECC circuit, 55 ・ ・ ・ Data modulator, 57 ・ ・ ・ A
/ D converter, 58 ... data discriminator, 59 ...
Data demodulator, 60 ... ADIP decoder, 61 ...
・ Band pass filter, 63 ・ ・ ・ Comparator, 64
... PLL circuit, 64a ... voltage controlled oscillator, 64
b: frequency divider, 64c: phase comparator, 64d ...
・ Low-pass filter, 67: decode processing circuit, 6
9 ... decoder, 70 ... data clock regenerator,
71: bandpass filter, 73: edge detector, 75: comparator, 76: AND circuit,
77: voltage-controlled oscillator, 78: frequency divider, 79,
81: phase comparator, 80: low-pass filter,
82 high-pass filter 83 connection switch 84 adder 100 preformat device 101 semiconductor laser source 104 105
..Beam on / off means, 111, 112, wobble means, 115, optical means, 46, polarity discriminating circuit, 90, oscillator, 92, multiplying circuit

Claims (4)

[Claims] In a disk recording and reproducing apparatus using a disk in which marks having phase information are preformatted, a data recording and reproducing light source is driven by a driving signal in which a pulse signal synchronized with a data clock signal is superimposed, A data recording / reproducing apparatus, wherein superimposition of the pulse signal is interrupted only during the pre-formatted period during data recording, and the light source is driven in a reproducing power mode. 2. A disk recording / reproducing apparatus using a disk in which marks having phase information are preformatted, wherein a data recording / reproducing light source is driven by a driving signal in which a pulse signal synchronized with a data clock signal is superimposed. A disk recording / reproducing apparatus, wherein a signal having a frequency sufficiently higher than the pulse signal is superimposed instead of the pulse signal during a period in which the mark is preformatted during data recording. 3. A disk recording apparatus according to claim 2, wherein a semiconductor laser is used as a light source, and a frequency in a frequency band capable of reducing noise of said semiconductor laser is selected as said superimposed frequency. Playback device. 4. A disk recording / reproducing apparatus using a disk in which marks having phase information are preformatted, wherein a data recording / reproducing light source is driven by a driving signal in which a pulse signal synchronized with a data clock signal is superimposed. A disk recording / reproducing apparatus wherein a signal having a frequency several times higher than that of the pulse signal is superimposed in place of the pulse signal during a period in which the mark is preformatted during data recording.