JPH05258469A - Method for controlling optical disk recording medium and recording and reproduction device - Google Patents

Abstract

PURPOSE:To perform a satisfactory recording and reproduction and to improve the recording capacity by providing connection area is the boundary of each zone and the unique patterns for speed control. CONSTITUTION:On the boundary of zone A (tracks TA1-TAn) and zone B (tracks TB1-TBn), four tracks of trangent area TT (tracks TT1-TT4) are provided. Thus, the clock continuity is secured over zones, and the crosstalk by ROM pit of the adjacent zone is eliminated to perform good recording/reproduction. Further, the unique pattern of wobbling pits WP1 and WP2 is detected. Based on the linear speed information obtained from the pattern, the rotation speed control or the pit clock frequency control can be readily performed to improve the recording information capacity.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is a so-called zoning system in which digital data of different clock rates is recorded in each zone while being divided into a plurality of zones in the radial direction and CAV rotation controlled at least in each zone. The present invention also relates to an optical disk recording medium, and an operation control method at the time of recording / reproducing or seeking of a recording / reproducing apparatus corresponding to this zoning type optical disk recording medium.

[0002]

2. Description of the Related Art In a recording / reproducing system for recording / reproducing various data by using an optical disk or a magneto-optical disk as a recording medium, a constant rotational speed is used as a disk rotational speed control method at the time of recording / reproducing data. CAV (constant angular velocity) control method for recording / playback with
There is a CLV (constant linear velocity) control method for recording / reproducing at a constant linear velocity. Comparing these two types of control methods, in the CAV method, the speed control is relatively simple and the control data such as track addresses can be recorded aligned in the disk radial direction, so that the address search can be performed easily. There is an advantage that However, since the recording density on the outer peripheral side of the disc is lower than that on the inner peripheral side,
It is difficult to improve the amount of stored information.

On the other hand, in the case of the CLV system, the speed control system is complicated because it is necessary to change the rotation speed according to the position of the optical pickup, but the CAV system can be used because the recording density can be made constant on the inner and outer circumference sides. It is possible to increase the amount of recorded information compared to. However, since it is difficult to record the control information such as the track address in the radial direction of the disc, it is disadvantageous that the address search takes time.

Generally, in the case of a magneto-optical disk having a large data storage capacity, an address search is easily performed in order to easily search for necessary data.
The method is often adopted. However, since the CAV method has disadvantages for improving the recording capacity as described above, the zoning recording method has been proposed as a method for increasing the storage capacity in the CAV method.

FIG. 9 shows an example of a recording medium (magneto-optical disk) on which zoning recording is performed. The data recording area of the disk is divided into three zones from zone A to zone C from the inner circumference side to the outer circumference side. It was done.
In this case, the tracks in each zone are recorded / reproduced at the same rotation speed, but the recording capacity can be improved by changing the rotation speed or the clock frequency for each zone.

FIGS. 10 and 11 are for explaining the improvement of the recording capacity by the zoning method. FIG. 10 shows an example of the zoning method, and FIG. 11 shows an example of the CAV method without zone division. The state which recorded data is shown typically.

When zoning recording is performed as shown in FIG. 10, the innermost tracks T _A1 , T _{B1 of} each zone A, B, C are recorded.
The recording linear density of T _C1 is set to be the same. Since CAV control is performed in each of the zones A, B, and C, the recording linear density decreases as the tracks on the outer peripheral side in the zones change, but when the zone changes, the clock frequency or rotation speed of the recording data changes. Therefore, the recording linear density of one track can be returned to a high state again. For example, when the rotation speed is variable for each zone, the relationship between the rotation speed and the transfer rate (= linear velocity) corresponding to each zone is as shown in FIG.

Therefore, it is possible to significantly increase the storage capacity as compared with the case where the recording linear density is sequentially reduced to the outermost track as in the case where the zones are not divided as shown in FIG. In particular, by increasing the number of divided zones, the recording linear density of the outermost track of each zone is secured to some extent, and the storage capacity can be further improved.

The broken lines in FIG. 9 indicate the sectors within one track, and the positions of the sectors are aligned in the radial direction of the disk due to the CAV system in each zone. Since the control information such as the track address and sector address is recorded at the beginning of the sector, these control information are aligned in the disc radial direction within the zone.

In addition, a continuous composite servo (CCS) is used as a servo control system of the optical disc system.
The method and the sampled servo method are known, and either method can be adopted as the zoning method. For example, in the case of the sampled servo method which is often used in a magneto-optical disk system, each sector in one track is shown in FIG. As shown in a), the data segment DS is further divided into a plurality of segments, and header segments H ₁ and H ₂ in which control data is recorded are provided at the head side of the sector, and subsequently, a data DB is recorded in which a data DB is recorded. _{1 to} DS _n are provided.

Then, as shown in FIG. 13B, each segment of the header and the data (H ₁ , H ₂ , DS _{1 to} DS).
Servo area SB is provided at the beginning position of _n )
In this servo area SB, a pair of wobbling pits P ₁ and P ₂ which are deviated from the center of the track T to the outer circumference side and the inner circumference side by a quarter track pitch are used as tracking servo information, and A clock pit P ₃ is formed in advance on the center line of T as clock extraction information by embossing or the like. Also, track information (for example, the lower 4 bits of the track address)
Similarly, the access code indicating is formed as pits P ₄ and P ₅ forming the gray code. A mirror surface M is formed at the rear of the wobbling pits P ₁ and P ₂ and the clock pit P ₃ , and the focus servo signal is detected by the laser light reflected from the mirror surface M and the laser power control is performed. Will also be done.

[0012]

However, such a zoning system has the following disadvantages and has a problem that it is difficult to put it into practical use in spite of the advantage of improving the recording capacity.

First, as can be seen from FIG. 9, the head positions of the respective sectors are aligned in the radial direction with respect to the tracks in the zones, but they are displaced at the boundary portion between the zones. Here, the address is recorded in the head portion of the sector by embossed pits (ROM pits) as described above, and in the case of the sampled servo system, each pit in the servo area is also recorded by ROM pits, while normal data is Magneto-optical (MO) recording will be performed, but at the boundary of the zone, the ROM pit area and M
A part where the O regions are adjacent to each other is generated. in this case,
There is a problem that good MO recording / reproducing operation cannot be performed due to interference from adjacent ROM pits. Furthermore, it is difficult to ensure the continuity of the clock for data extraction when crossing the zones.

In addition, since the rotation speed or the clock rate must be changed when crossing each zone in the zoning system, there is a drawback that the control operation becomes complicated and the clock extraction becomes difficult. Bit synchronization cannot be achieved during seek, and address extraction cannot be performed. This causes a problem that the high speed seek operation is impossible.

[0015]

The present invention has been made in view of the above problems, and an object thereof is to realize a high density recording by using a zoning recording method as a sufficiently practical recording method. To do.

First, as a zoning type optical disk (magneto-optical disk), a connecting area is provided at the boundary of each zone. In particular, at least information for tracking servo control is recorded in this joint area.

Further, in a zoning type optical disc provided with such a joint area, a tracking servo control is performed based on sample information of predetermined tracking information pits discretely formed. When the disk rotation speed is variable in each zone in the system of the system, the unique pattern obtained by the tracking information pit or the unique pattern detection dedicated pit is detected, and the spindle rotation in which the spindle servo is executed based on this detection output. An operation control method is provided.

On the other hand, in a zoning type optical disc similarly provided with a joint area, a tracking servo control is performed based on sample information of predetermined tracking information pits discretely formed. In this system, if the clock frequency is changed for each zone, the unique pattern obtained by the tracking information pit or the unique pattern detection pit is detected, and the bit clock frequency is changed based on this detection output. And a bit clock control method.

Further, in the same system in which the rotation speed or the clock rate is variably controlled for each zone, the first unique pattern obtained by the tracking information pit or the unique pattern detection dedicated pit is detected, and the bit is detected based on this detection output. The current address can be read by generating a clock and detecting the second unique pattern that is the address position information using this bit clock, and the seek operation is performed by comparing the read current address with the target address. A seek operation control method to be performed is provided.

[0020]

By providing a joint area (transient area) in which only servo information is recorded and which is not used for actual MO data recording, the ROM pit area and the MO area are separated from each other in the radial direction of the disk by the displacement of the sector position. Can be eliminated next to. As a result, good recording / reproducing operation can be realized.

Further, if the unique pattern obtained by the tracking information pit or the unique pattern detection dedicated pit is detected, the linear velocity (linear density) information in the zone can be obtained. Therefore, the spindle variable control can be easily performed based on this detection output. Alternatively, variable bit clock control can be performed.

Further, since it is possible to easily extract whether the bit clock is constant or variable, it is possible to detect a unique pattern which becomes address position information at the time of seek, that is, it is possible to read an address during seek.
Therefore, seek can be performed while comparing the current address and the target address, and a high-speed seek operation is realized.

[0023]

Embodiments of the optical disk (magneto-optical disk), spindle rotation operation control method, clock control method, and seek operation control method according to the present invention will be described below.

<Optical disc (magneto-optical disc)> As shown in FIG. 9, a magneto-optical disc according to an embodiment of the present invention is divided into a predetermined number of zones (zone A to zone x) in the disc radial direction. As described above, the tracks in each zone are recorded / reproduced at the same rotation speed (CAV method), but by changing the rotation speed or the clock frequency for each zone, recording is performed from a normal CAV optical disk. The capacity can be improved. A sampled servo system is used as the servo control system.

FIG. 1 schematically shows the boundary between zone A and zone B in the magneto-optical disk of this embodiment, and FIG. 2 shows the sector structure of this magneto-optical disk. One track is divided into a plurality of units of sectors, and each sector is composed of, for example, 52 units of segments. As shown in FIG. 2, 13-byte header segments H ₁ and H _{2 in} which control information such as address data is recorded by ROM pits, for example, are provided at the beginning of a sector, and MO data is subsequently recorded. 13-byte data segment DS _{1 to} DS
₅₀ are provided.

The first 1 byte (= 8 bits) of the header segments H ₁ and H ₂ and the data segments DS _{1 to} DS ₅₀ is set as a servo area SB, which is a predetermined amount from the track center Tc to the outer and inner circumference sides of the disk. The shifted wobbling pits WP ₁ and WP ₂ are formed and used as tracking information. That is, the wobbling pit WP ₁ ,
The tracking error signal is extracted by calculating the difference between the reproduced signals by WP ₂ .

An 8-bit long address mark AM is formed in the second byte following the servo area SB in the header segment H ₁ , and this address mark AM has address information (address pit A
_P ) is used as the discrimination information that is recorded. The 2nd to 13th bytes in the data segments DS _{1 to} DS ₅₀ are used as MO areas, and the required data are magneto-optically recorded as MO pits P _MO . Therefore, 600 bytes of data can be recorded per sector.

Here, the minimum distance of the data reproduction pits such as the address pit A _P and the MO pit P _MO is the case of this example.
It is set to 2.6τ, and the longest pit length is set to 5.3τ. However, the distance between the wobbling pits WP ₁ and WP ₂ is set to 2τ, and the address mark AM
The pit length is set to 8τ (out of rule), that is, the wobbling pits WP ₁ and WP ₂ are set as the shortest unique pattern, and the address mark AM is set as the longest unique pattern.

The magneto-optical disk of this embodiment has such a sector format, and as shown in FIG. 1, zone A (tracks T _{A1 to} T _An ) and zone B (tracks T _{B1 to} T _Bn ). In the boundary portion of, the transient area TT for 4 tracks (tracks TT _{1 to} TT ₁
T ₄ ) is provided.

The broken line in the figure indicates the boundary of the segment SG (hereinafter, simply referred to as the segment SG if no distinction is required for the header segments H ₁ and H ₂ or the data segments DS _{1 to} DS ₅₀ ) in each track. As shown, as described above, the segments SG of the final track T _An of the zone A and the first track T _B1 of the zone B are not aligned in the radial direction. In the segment SG of each track of zones A and B, the wobbling pit W
The shaded area D following P ₁ and WP ₂ is the address and M
An area in which O data is recorded is shown.

In the transient area TT, only wobbling pits WP ₁ and WP ₂ as tracking information are formed in each segment SG, and control information such as MO data and address is not recorded. In the transient area TT, the two tracks TT ₁ and TT ₂ on the zone A side have their segment positions aligned with the zone A in the radial direction of the disk. Therefore, the wobbling pits WP ₁ and WP _{2 of the} tracks TT ₁ and TT ₂ are aligned.
The (servo area SB) is not adjacent to the MO area (data area D) in the final track T _An of the zone A.

Two tracks TT on the zone B side
₃ and TT ₄ , the segment position is aligned with the zone B in the disk radial direction, and therefore the tracks TT ₃ and TT 4 are
₄ wobbling pits WP ₁ and WP ₂ (servo area S
B) is not adjacent to the MO area (data area D) in the first track T _B1 of zone B. Truck TT
The boundary between ₂ and TT ₃ , that is, the leading segment of the track TT ₃ is a transient segment SGH as a buffer for changing the segment length. (In the case of this embodiment, the tracks are spirally formed continuously from the inner circumference to the outer circumference of the disk.)

By providing such a transient area TT, the MO area of the first track or the last track of each zone is satisfactorily MO due to the interference of the ROM pits in the adjacent zones, especially the wobbling pits WP ₁ or WP _2. The obstruction of the recording / reproducing operation is eliminated. Further, since the PLL synchronization can be sufficiently obtained during the scanning of the transient area TT, the continuity of the bit clock can be easily ensured. In the present embodiment, the bit clock is extracted in the wobbling pit W.
This clock extraction operation is executed by detecting P ₁ and WP ₂ , but will be described later. The transient area TT does not necessarily have to be 4 tracks. In some cases, it may be possible to record control information such as an address in the transient area TT.

By the way, in order to perform high-density recording and reproducing operations corresponding to the above-mentioned magneto-optical disk, the rotation speed must be variably controlled in units of zones, or the clock rate must be variably controlled in units of zones. I won't. Therefore, first, an embodiment of a spindle operation control method in the case where a method of variably controlling the rotation speed in units of zones is adopted will be described.

<Spindle Operation Control Method> FIG. 3 is a block diagram showing a main part of an optical recording / reproducing apparatus in which the spindle operation control method of the present invention is adopted, and 1 is the zoning system described in FIGS. 1 and 2. The magneto-optical disk 1 has a track format of 1. The magneto-optical disk 1 is rotated by a spindle motor 2 at a constant angular velocity (CAV) in each zone.

An optical head 3 for irradiating a laser beam at the time of recording or reproducing is arranged below the magneto-optical disk 1.
As is well known, the optical head 3 is composed of an optical system including a laser emission source, a diffraction grating, a collimator lens, a beam splitter, a biaxial device for controlling an objective lens, and a magneto-optical disk. A polarizing beam splitter for detecting the reflected light of the above, and one or a plurality of detectors are provided.

At the time of reproduction, the reflected light from the laser spot emitted from the laser emission source to the magneto-optical disk 1 through the optical system is detected by the photodetector and recorded MO information, address, servo, etc. ROM of
Information is obtained. In addition, during recording, the laser spot is continuously irradiated and is used to set the recording surface of the magneto-optical disk 1 above the Curie point. Data is recorded by the magnetic field applied by the magnetic head 20 from the side opposite to the disk surface.

The output of the photodetector in the optical head 3 is supplied to the arithmetic circuit section 4 and various reproduction information is generated. For example, when two photodetectors for detecting the P-polarized component and the S-polarized component of the reflected light are provided, the arithmetic circuit unit 4 calculates the difference between the two photodetectors and MO
A data reproduction signal S _MO is obtained.

Further, the servo area SB of each segment SG
A tracking error signal is generated by taking a difference between the detection outputs of the wobbling pits WP ₁ and WP ₂ formed in the above, and a focus error signal is generated from the detection output of the mirror surface (non-pit portion). These servo signals S _SV are supplied to the servo circuit 5 to drive the biaxial device, and tracking servo and focus servo are executed.

Further, the RF reproduction signal S _RF of the ROM data such as address information is obtained by taking the sum of the outputs from the respective divided surfaces of the photodetector. The reproduction signal S _RF of the ROM data is supplied to the address decoding unit 7 via the RF amplifier 6, and information such as a track address and a sector address is extracted and input to the system controller 8. The system controller 8 is composed of, for example, a microcomputer, and outputs a bit clock C _K and a control signal C _ONT to required parts during various operations to control the entire operation.

Reference numeral 10 denotes an MO data decoding unit for decoding the MO signal S _MO extracted from the arithmetic circuit unit 4,
Reference numeral 11 is a binarization processing unit that performs binarization processing of the supplied signal, 12 is a data reproduction processing unit that extracts data by a difference detection method, and 13 is an ECC processing unit that performs error detection and error correction. The output after the ECC processing is supplied from a terminal 14 to a predetermined circuit section.

On the other hand, for the magneto-optical disk 1, a magnetic head portion 20 is provided at a position facing the optical head 3.
A magnetic field that is inverted by the recorded data is applied. That is, the recording data supplied from the terminal 21 is subjected to predetermined code modulation and blocking in the recording data processing unit 22, and further, an error correction code and the like are added, and the recording data is supplied to the magnetic head 20 as recording data.

A clock generator 30 generates a bit clock C _K used for recording / reproducing operation using a PLL loop, and has an edge detection circuit 31, a phase comparator 32, a voltage controlled oscillator (VCO) 33, and a frequency divider. It is composed of 34. In the edge detection circuit 31, the wobbling pit WP
₁ , the rising edge of the reproduced RF signal waveform obtained by WP ₂ is detected, and this is input to the phase comparator 32. On the other hand, the output of the VCO 33 is divided by the divider 34 by 1 / M,
It is input to the phase comparator 32. Then, the oscillation frequency of the VCO 33 is controlled based on the comparison information voltage by the phase comparator 32, and the bit clock C _{K is} output as the output of the VCO 33.
Is obtained and supplied to the system controller 8.

Reference numeral 40 is a shortest pit detector for detecting a unique pattern of the shortest wavelength from the reproduced RF signal,
The magneto-optical disc 1 is wobbling pits WP _1, WP ₂ is shortest unique pattern as shown in FIG. 2 (2
τ), the time information of 2τ is output (shortest wavelength detection signal in FIG. 2). The time information of 2τ is converted into a voltage value by the time-voltage conversion unit 41 and input to the calculation unit 42. The calculation unit 42 includes a reference voltage generation unit 4
3, a predetermined reference value is supplied, and the time information of the shortest unique pattern converted into a voltage value is compared and calculated with the reference value. The calculation result is the spindle servo amplifier 4
4 and the rotation speed of the spindle motor 2 is controlled.

That is, since the detected time information has a property as a linear velocity (linear density) detection signal in each zone, the wobbling pit WP is calculated in the arithmetic unit 42.
₁ and WP ₂ outputs an error signal for equalizing the time information 2τ of the unique pattern in each zone, and the spindle servo is executed based on this error signal, so that a predetermined rotation is performed for each zone. Speed control is realized.

As described above, the wobbling pit WP
By detecting the unique pattern of the shortest wavelength formed by ₁ and WP ₂ , the bit clock C _K is generated, and the spindle rotation speed control for each zone is performed based on the time information, thereby supporting the zoning method. The recording / reproducing device can be easily realized.

By variably controlling the rotation speed in units of zones in this way, high density recording in the zoning system becomes possible. However, as described above, variably controlling the clock frequency in units of zones also ensures high density recording. realizable. In particular, when it is desired to increase the seek operation speed, it may be difficult to control the spindle speed. However, in such a case, the normal CAV system is used for the rotation control, and the zoning system can be supported by making the clock variable. You can do this. Therefore, an embodiment of the clock control method in the case where the system in which the rotation frequency is controlled to be constant but the clock frequency is variably controlled in units of zones is adopted will be described next.

<Clock Control Method> FIG. 4 is a block diagram showing a main part of an optical recording / reproducing apparatus to which the clock control method of the present invention is applied. The same parts as those in FIG. 3 are designated by the same reference numerals and the description thereof will be omitted. A magneto-optical disk 1 having a zoning type track format is rotationally driven by a spindle motor 2 at a constant angular velocity (CAV). That is, the rotation speed is controlled at a constant speed based on the output of the servo amplifier 9 that compares the output of the frequency generator (FG) 2a attached to the spindle motor 2 with a predetermined reference value R _EF .

Reference numeral 50 denotes a clock generator for obtaining a bit clock C _K which is variable for each zone in the present embodiment, and has an edge detection circuit 51, a phase comparator 52, a voltage controlled oscillator (VCO) 53, and a frequency divider. In addition to having a PLL loop composed of a device 54, a shortest pit detection unit 59, time-voltage conversion units 55 and 56, and calculation units 57 and 58 are provided in order to incorporate time information into this PLL loop.

The edge detection circuit 51 detects the rising edge of the reproduced RF signal waveform obtained by the wobbling pits WP ₁ and WP ₂ and inputs it to the phase comparator 52, while the output of the VCO 53 is 1 / M by the frequency divider 54. The frequency is divided and input to the phase comparator 52. The output of the phase comparator 52 is supplied to the VCO 53 via the calculator 58. And V
The oscillation frequency of the CO 53 is controlled based on the output of the arithmetic unit 58, and the bit clock C _K is obtained as the output thereof.
It is supplied to the system controller 8.

Here, the shortest pit detection section 54 reproduces the RF.
A unique pattern of the shortest wavelength, that is, a unique pattern of 2τ due to the wobbling pits WP ₁ and WP ₂ in the case of the magneto-optical disk 1 is detected from the signal, and its time information (the shortest wavelength detection signal in FIG. 2, the line in each zone) is detected. When a velocity (linear density) detection signal is output), the time information is converted into a voltage value by the time-voltage conversion unit 55 and input to the calculation unit 57.

The calculation unit 57 is also supplied with the output of the time-voltage conversion unit 56 which converts the time information about the output of the frequency divider 57 into a voltage value, and performs a comparison calculation for these two time information values. , The difference is used as error information for clock variable control. This error information is calculated by the calculation unit 58 as the phase information, that is, the output of the phase comparator 52, and VC
It is output as the control voltage of O53.

With the clock generator 50 having such a configuration, the shortest unique pattern (wobbling pit WP
Based on the detection of ₁ and WP ₂ , a bit clock C _K having a predetermined frequency different for each zone can be obtained.
Therefore, the recording / reproducing operation corresponding to the zoning system can be performed even if the spindle motor 2 is still in CAV control.

In order to generate the bit clock C _K in the above clock control method or to generate the spindle servo information and the bit clock in the above spindle operation control method, it is necessary to detect the shortest unique pattern. This shortest unique pattern is set as wobbling pits WP ₁ and WP _2. For example, as shown in FIG. 5, the _first 2 bytes of each segment SG are set as servo areas SB ₁ and SB _2, and tracking information is set in the servo area SB _2. For this purpose, it is possible to provide wobbling pits WP ₁ and WP _{2 and} to provide pits UP that form a unique pattern with the shortest wavelength in the servo area SB ₁ . In this case, needless to say, the spindle servo information or the bit clock generation control information is obtained as described above based on the detection information of the reproduction RF signal of the pit UP.

Further, without using the wobbling pits at all, for example, a pit UP forming a unique pattern of the shortest wavelength is provided in the servo area as shown in FIG. 6 to obtain the shortest wavelength detection signal as shown in FIG. Conceivable. In this case, a push-pull signal may be obtained using the pit UP or another pit for tracking control. Further, one pit UP may be provided as shown in FIG. 7, and the rising and falling edges of the reproduction signal thereof may be detected to obtain the time information of the shortest wavelength.

<Seek Operation Control Method> Next, a seek operation control method realized according to the above embodiment will be described. In the zoning method, in the past, high-speed seek was impossible because bit synchronization could not be obtained during seek, that is, bit clock could not be obtained, but as described above, bit clock is detected based on the detection of the shortest unique pattern. P is generated even during seeking by generating C _K
The LL loop is locked, that is, bit-synchronized, which allows segment synchronization. Furthermore, if bit synchronization is achieved, the address mark AM (see FIG. 2) formed with the out-of-rule 8-bit length as the longest unique pattern can also be detected, and the sector synchronization can be achieved.

Therefore, since the address of the current position can be read during the seek based on the detection of the address mark AM, a high speed seek is realized by performing the seek operation while comparing this with the address of the seek target point. It

It is shown below that the shortest unique pattern can be detected during seek. The track pitch is T _P ,
The shortest wavelength is T _MIN , the seek velocity is V _S , and the linear velocity is V _T. Normally, the condition for eliminating the possibility of erroneously detecting ROM information of adjacent tracks as the shortest wavelength during seek is T _MIN (m) / V _T (m / sec), that is, the period (sec) of the highest frequency, It is sufficient that (T _P / V _S )> (T _MIN / V _T ) holds.

Therefore, as a general numerical value, T _P = 1.4
μm, T _MIN = 1 μm, V _S = 1 m / sec (practically the highest possible seek speed), V _T = 10 m / sec
(At a rotation speed of 600 rpm), then, T _P / V _S = 1.4 × 10 ^-6 (sec) T _MIN / V _T = 1 × 10 ^-7 (sec), that is, (T _P / V _S ). Since> (T _MIN / V _T ) is satisfied, it can be seen that the shortest unique pattern can be detected during the seek, and thus the bit clock C _K can be obtained. If the bit clock C _K is obtained, the address mark AM can be detected and the track address can be read.

The linear velocity is 2 m / sec and the maximum velocity when the actuator is seek driven by the bang-bang control is 0.033.
Assuming that the track pitch is m / sec and the track pitch is 1.5 μm, assuming that the data can be decoded in the detrack state between ± 1/4 tracks, at least 75 bits (9.3 (Byte) data can be detected. That is, an address mark having a 1-byte length can be detected, and adjacent 2-byte data can be continuously detected. Therefore, as the track address is recorded in pairs for MSB to LSB, as shown in FIG. 8, for example, it is possible to detect with accuracy according to the speed.

Even if the seek speed is further increased,
If the track address is gray-coded and recorded, at least as long as the address mark AM can be detected (that is, if it can be continuously detected for at least about 1 byte), an error occurs due to the nature of the gray code. The track address can be detected with few.

Contrary to the above embodiment, in the present invention, the shortest unique pattern is set as an address mark, and the longest unique pattern is set as spindle velocity or clock control as linear velocity (linear density) detection information. Good. Further, although the above embodiment has been described in association with the sample servo system, providing a transient area between each zone is also effective when zoning is adopted in the CCS system.

[0063]

As described above, according to the present invention, by providing a transient area at the boundary of each zone in the zoning format, it is possible to ensure the continuity of the clock when the zones are crossed and the R of the adjacent zones.
Good recording by eliminating crosstalk due to OM pits
Reproducing operation becomes possible. Furthermore, by controlling the rotation speed or bit clock frequency based on the linear velocity information obtained by the unique pattern, these controls are facilitated. Therefore, the zoning method is put into practical use and the data recording capacity is improved. This has the effect of significantly promoting measurement. Furthermore, it is possible to achieve bit synchronization even at the time of seek, and it is also possible to realize high-speed seek operation by enabling address extraction.

[Brief description of drawings]

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

FIG. 2 is an explanatory diagram of a sector structure of a magneto-optical disk of an example.

FIG. 3 is a block diagram of a main part of a recording / reproducing apparatus in which the spindle operation control method of the present invention is adopted.

FIG. 4 is a block diagram of a main part of a recording / reproducing apparatus that employs the clock control method of the present invention.

FIG. 5 is an explanatory diagram of another example of the unique pattern of the embodiment.

FIG. 6 is an explanatory diagram of another example of the unique pattern of the embodiment.

FIG. 7 is an explanatory diagram of another example of the unique pattern of the embodiment.

FIG. 8 is an explanatory diagram of a track address recording method according to an embodiment.

FIG. 9 is an explanatory diagram of a zoning type optical disc.

FIG. 10 is an explanatory diagram of recording capacity improvement by a zoning method.

FIG. 11 is an explanatory diagram of a storage capacity according to the CAV method.

FIG. 12 is an explanatory diagram of an example of zone-based control in the zoning system.

FIG. 13 is an explanatory diagram of a sector structure in the sampled servo system.

[Explanation of symbols]

1 Magneto-optical disk 2 Spindle motor 30,50 Clock generator 31,51 Edge detector 32,52 Phase comparator 33,53 VCO 34,54 Frequency divider 40,59 Shortest pit detector 41,55,56 Time-voltage Conversion unit 42, 57, 58 Calculation unit 44 Servo amplifier WP ₁ , WP ₂ Wobbling pit TT Transient area

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Claims (5)

[Claims] 1. A predetermined number of zones are formed in the radial direction,
An optical disc recording medium in which digital data is recorded at a different rotation speed or a different clock frequency in each zone while maintaining a constant rotation speed in at least each zone, a joint area is provided at the boundary of each zone. An optical disk recording medium characterized by: 2. The optical disc recording medium according to claim 1, wherein at least information for tracking servo control is recorded in a connecting area provided at a boundary portion of each zone. 3. A predetermined number of zones are formed in the radial direction,
At least in each zone, while keeping the rotation speed constant, digital data is recorded at different rotation speeds or different clock frequencies in each zone, and a joint area is provided at the boundary of each zone, and discrete. Of the tracking information pits or the unique pattern detection dedicated pits for the sampled servo type optical disc recording medium in which the tracking servo control is performed based on the sample information of the predetermined tracking information pits A spindle rotation operation control method, characterized in that a unique servo pattern is detected and spindle servo is executed based on the detected output. 4. A predetermined number of zones are formed in the radial direction,
At least in each zone, while keeping the rotation speed constant, digital data is recorded at different rotation speeds or different clock frequencies in each zone, and a joint area is provided at the boundary of each zone, and discrete. Of the tracking information pits or the unique pattern detection dedicated pits for the sampled servo type optical disc recording medium in which the tracking servo control is performed based on the sample information of the predetermined tracking information pits The bit clock control method is characterized in that the frequency of the bit clock is made variable based on the detected unique pattern. 5. A predetermined number of zones are formed in the radial direction,
At least in each zone, while keeping the rotation speed constant, digital data is recorded at different rotation speeds or different clock frequencies in each zone, and a joint area is provided at the boundary of each zone, and discrete. Of the tracking information pits or the unique pattern detection dedicated pits for the sampled servo type optical disc recording medium in which the tracking servo control is performed based on the sample information of the predetermined tracking information pits The present invention makes it possible to read the current address by detecting a first unique pattern that is generated and generating a bit clock based on this detection output, and detecting a second unique pattern that is address position information using this bit clock. , The current address loaded A seek operation control method characterized in that a seek operation is performed by comparing a target address with a read address.