JP3256999B2 - Optical disk recording / reproducing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a ROM area and an RA area.
The present invention relates to a recording / reproducing method for an optical disk having an M area (magneto-optical recording area).

[0002]

2. Description of the Related Art An optical disk system capable of recording various data on an optical disk by irradiating a spiral track with a laser beam and reading the recorded data includes a track on which data on the optical disk is arranged. And the sampled servo system formed by sampled servo pits in which tracks for arranging data are discretely arranged.

[0003] Figure 9 is S ₁ to S at illustrates an example of the format of ROM mixed type optical magnetic disk when the recording track is formed by a sample servo pits
Reference numeral ₄₂ denotes, for example, a sector divided into 42 in the circumferential direction.

[0004] Tracks in each sector are shown in FIG.
Header segment H ₁ to address data as shown in (a) is a region that has been recorded are pits formed in advance by embossing or the like is provided, followed by a header segment H ₂ is provided. And when mode using the header segment H ₂ is various present by the difference in format, for example, is a magneto-optical (MO) recording area is used as a trial writing area immediately before performing the data recording / reproducing, or R
There are cases where predetermined data is formed by emboss pits as the OM area.

Furthermore, subsequent to this header segment H _2, for example, 20 bytes of data the data storage area DB can be recorded are formed by dividing the data segments SG ₁ to SG ₃₀ 30. This data segment SG _1-
The region consisting of SG ₃₀ in the optical disc, M
There is a portion where the data can be written / read as an O region and a portion where the data can be read only as a ROM region by emboss pits or the like.

In the MO area, when a recording surface is irradiated with a laser beam along a track and a magnetic field is applied from the other surface of the magneto-optical disk, the magnetic field is applied when the recording surface is above the Curie point. It is magnetized in the direction of the magnetic field and data is recorded. When information is read from a magneto-optical disk on which data is recorded, the recorded data is read by detecting the reflected light of the laser beam using the magnetic force effect.

In each data segment (SG _{1 to} SG ₃₀ ) or header segments H ₁ and H ₂ , a servo byte SB is first arranged as shown in FIG. 10B, followed by an address and a ROM. An area for recording data and MO data is formed.

In the servo byte SB, a pair of wobbling pits P ₁ and P ₂ deviated at least from the center of the track T to the outer circumference and the inner circumference, and are arranged on the center line of the track T. clock pit P ₃ are formed in advance by embossing. An access code indicating track information is similarly formed by pits P ₄ and P ₅ forming a gray code. or,
Wobbling pit P _1, P ₂ and the clock pit P
_A mirror surface M is formed at the rear of the mirror surface _3. The laser beam reflected from the mirror surface M detects a focus servo signal and controls the laser power.

In such a magneto-optical disk, a tracking error signal is formed by calculating reflected light when the wobbling pits P ₁ and P ₂ are detected at sample points t ₁ and t ₂ , and the clock pit P _Three Forms a master clock signal.

[0010]

By the way, in such a ROM / MO mixed type optical disk, the segment unit classification in the optical disk includes an address area (header segment H ₁ ) and a ROM data area (RO).
M data segment) and MO data area (RAM
Data segment), but after the master clock is generated by the PLL lock, in order for the system to perform rotation synchronization such as sector synchronization and segment synchronization, at least the header segment located at the beginning of each sector. it is necessary to detect the H _1. That is, the rotational synchronization is achieved by obtaining a segment synchronization by detecting the header segment H _1. Therefore, recording /
During the playback operation, it must be accurately determined whether the current scanning area is a header area. Further, it goes without saying that the discrimination between the ROM area and the MO area must be made accurately for the recording / reproducing operation.

Therefore, in an optical disk, especially a ROM
A mark (ROM mark) is formed at a predetermined position of the servo byte SB in the area by, for example, an embossed pit.
The segment type determination operation is performed based on the presence or absence of the M mark and whether or not the area (data storage area DB) following the servo byte SB has been recorded with embossed pits. In other words, header (address area) ··· without ROM mark + with emboss pit ROM data area ··· with ROM mark + emboss pit MO data area ··· ..........

Here, the initial startup sequence of the sampled servo system will be described. First, focus servo (continuous focus servo) control is performed, and then PLL lock is applied. After the PLL locks and the servo byte SB can be identified, the segment
In the optical head servo system, focus servo (sampled focus servo) control is performed. Further, in the optical head servo system, tracking servo control is performed after focus servo control. Therefore, in such an initial start-up sequence, the tracking-on state is not always obtained at the stage of performing the rotation synchronization control.

When the tracking is not turned on, the level of the RF signal reproduced by the ROM mark is naturally small, so that it is very difficult to determine the presence or absence of the ROM mark. Also, if the reproduction signal is affected by noise or defect before the tracking is turned on, the ROM
It is more difficult to determine the presence or absence of a mark.

In the MO area, there is a type in which guard bands are formed on both sides of a track. This guard band is usually formed to protrude slightly to the servo byte SB, so that it is distinguished from a ROM mark. It may be difficult to determine the presence or absence of the ROM mark.

In other words, the conventional method has a drawback that the determination of the ROM mark becomes inaccurate, which causes a problem that the type of each segment cannot be detected accurately and rotation synchronization cannot be obtained correctly. there were.

[0016]

SUMMARY OF THE INVENTION The present invention has been made in order to solve such a problem, and a concentric or spiral track is formed by being divided into a plurality of sectors. determine the leading position of the sector
The predetermined mark signal and the emboss pit used for the discriminating operation of the medium and the type of the medium are a recording / reproducing method for an optical disk recorded at a predetermined position in the sector. At least after the tracking control is executed, the predetermined
Performs determination and medium type discrimination of the head position of <br/> the sector based on a combination of the presence or absence of click signal and the emboss pit, times using the discrimination result of the head position of the sectors
Synchronization control, and then, based on the discrimination result of the media type.
The processing sequence is set so that the recording / reproducing operation is performed.

[0017]

When the tracking is on, the mark signal can be detected accurately. Therefore, the head position of the sector can be accurately determined using the detection information of the mark signal.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. FIGS. 5 to 7 are explanatory diagrams of an optical disk on which recording / reproduction is performed by the recording / reproduction method of the present invention. First, this optical disk will be described. The sector structure of this optical disk is the same as that shown in FIG. FIG. 5 shows a portion of the servo byte SB in the address area (header segment), FIG. 6 shows a portion of the servo byte SB in the ROM data segment, and FIG. 7 shows a portion of the servo byte SB in the MO data segment. In each of the drawings, T is a track, and P ₁ and P ₂ are a pair of wobbling pits P deviated from the center of the track T to the outer peripheral side and the inner peripheral side.
Reference numeral ₃ denotes a clock pit arranged on the center line of the track T, and P ₄ and P ₅ are pits forming a gray code indicating track information. M indicates a mirror surface.

The 1st to 40th pits are servo bytes SB in each segment, and the 41st pit is an area (address storage area or data recording area DB) in which various information is recorded. That is, in the header segment of FIG. 5, address data AD is recorded by emboss pits after the 41st pit, and in the ROM data segment of FIG.
For example NRZ the data D _R is likewise embossed pit
It is recorded in the i method. Further, in the MO data segment of FIG. 7, the 41st pit and subsequent pits are used as a magneto-optical recording area so that predetermined data can be recorded by a magnetic field modulation method.

Further, as can be seen from FIG.
The OM data segment pits are formed as a ROM mark PM _R 38th pit eyes. As shown in FIG. 7, a guard band GB is formed at a position shifted by 1/2 track in the magneto-optical recording area in the MO data segment, but a guard band is provided in the magneto-optical recording area depending on the type of the optical disc. Some things cannot be done. The reproduced RF signal waveform obtained by scanning each of such segments is shown at the bottom in each figure.

[0021] Therefore, for this optical disc, whether the servo byte S of ROM marks PM _R in the segment
If the presence or absence of emboss pits in the area following B (that is, the data recording area DB or the attress recording area) is detected, it is identified whether the scanned segment is a header segment, a ROM data segment, or an MO data segment. be able to.

One embodiment of the recording / reproducing method of the present invention for such an optical disk will be described with reference to FIGS. FIG. 1 is a schematic diagram of a recording / reproducing circuit to which the recording / reproducing method of the present embodiment is applied, and 1 is a magneto-optical disk having the track format described in FIGS. The magneto-optical disk 1 is driven to rotate at a constant angular velocity (CAV) by a spindle motor 2, for example. An optical head 3 for irradiating a laser beam during recording or reproduction 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 light source, a collimator lens, a beam splitter, a biaxial device for controlling an objective lens, and the like. A polarization beam splitter and a detector for detecting the In particular, the reflected light is split into a P deflection component and an S deflection component by the polarization beam splitter 3C, and is detected by the two detectors 3A and 3B.

The outputs of the detectors 3A and 3B are supplied to an arithmetic circuit 4a, and the arithmetic circuit 4a calculates the difference between the two outputs to obtain a reproduced signal of the magneto-optically recorded data.
Extract MORF . The outputs of the detectors 3A and 3B are supplied to an arithmetic circuit 4b, and the arithmetic circuit 4a takes the sum of the two outputs, thereby extracting a reproduction signal PPRF of the ROM data recorded by the embossed pit.
The reproduction signals MORF and PPRF are processed according to the scanning area.
It is selectively input to the road 10.

The detector 3A is, for example, a light receiving element having divided surfaces, and the output of each divided surface is supplied to the detection circuit 5.
Supplied. Then, the servo byte SB of each segment
Focus error signal is detected when scanning the mirror surface
It is obtained by the output circuit 5. Note that the detection circuit 5
Not only the focus error signal detection system
Also equipped with a detection system for pits P _{1 to} P ₃ of bobbit SB
I have. During the scanning period of the servo byte SB, the reproduction signal PPRF
(Reproduction signal from the embossed pit) from the arithmetic circuit 4b
The signal is supplied to the signal processing circuit 10. And the signal processing circuit 1
After being amplified by 0, the clamp circuit 11 and the offset circuit
12 is supplied. This clamp circuit
Play Shin by clamping voltage E _C supplied to the 11
Remove the DC offset component superimposed on the signal
The "0" level is set to a constant voltage. Also
The offset circuit 12 controls the offset level of the signal.
Perform a roll. This clamp circuit 11, offset circuit
12 offset control and clamped playback
The signal PPRF is supplied to the detection circuit 5 via the A / D converter 13.
Be paid. The detection circuit 5, the wobble pits P _1, P ₂
Generates a tracking error signal from the detection data,
Clock pit P ₃ (amplitude level before and after)
Generate a phase error signal. And the focus mentioned above
Error signal and tracking error signal are servo circuit
6 and the servo circuit 6 drives the two-axis device
Will be. Further, the detection circuit 5 detects the clock phase error signal.
Signal to the internal PLL circuit and the master clock signal
And supplies it to each digital circuit.

Reference numeral 9 denotes a spindle servo circuit, which controls the rotation of the optical disk by the spindle motor 2 at a constant angular velocity (CAV) based on the control of the system control section 8 using FG pulses.

The area (address) following the servo byte SB
When scanning the storage area or data recording area DB),
Signal processing according to area data format (ROM / MO)
The circuit 10 selects the signals MORF and PPRF. And selected
The processed signal is subjected to processing such as amplification, and then the clamp circuit 1
1. A / D converter 13 which is processed by the offset circuit 12
Is converted into digital data. And this A / D converter 1
The output of No. 3 is supplied to a data detection unit 15 formed of a digital circuit via a difference detection circuit 14.

That is, the reproduction information of the ROM data and the MO data, for example, by the NRZi type modulation method recorded in the area following the servo byte SB on the optical disk 1 is extracted by the decoding process in the data detection unit 15. Then, this ROM data segment, MO
Reproduction data of ROM data or MO data extracted by scanning the data segment is supplied to a reproduction processing circuit (not shown).

In the control data reproducing circuit 7, the difference
The presence / absence of a mark pit (ROM mark PM _R ) in the segment and the gray code (P ₄ , P ₅ ) are detected from the reproduction signal of the servo byte SB supplied from the minute detection circuit 14 . Further, the information format in the data recording area DB or the address storage area in each segment, that is, the presence or absence of emboss pits is detected. These pieces of detection information are supplied to the system control unit 8 and used as reference data for, for example, rotation synchronization control. Further, the control data reproducing circuit 7 extracts the address information recorded in the header segment and supplies it to the system control unit 8.

On the other hand, a magnetic head unit 30 is provided at a position facing the optical head 3 with respect to the magneto-optical disk 1,
A magnetic field that is reversed by the recording data is applied. That is, the recording data supplied from the terminal 31 is added with an error correction code or the like in the recording data processing unit 32 ,
Blocking is performed, predetermined code modulation is performed, and the data is supplied to the magnetic head 30 as recording data.

In such a recording / reproducing apparatus, the control sequence of this embodiment executed by the system control unit 8 at the time of initial startup is shown in FIG. That is,
In the initial start-up phase (F100) in which the optical disc 1 is rotationally driven by the spindle motor 2 and the constant-speed rotation control is started by the spindle servo circuit 9, first, a continuous focus servo operation is executed (F101).
Subsequently performs PLL lock process, on the basis of the reproduction signal of the cloak pit P ₃ of the servo byte SB, obtain master clock (F102). Since the servo byte SB can be specified on the scanning track by performing the PLL lock, focus control (sampled focus servo) is first performed from the reproduction information of the servo byte SB (F103), and then wobbling of the servo byte SB is performed. Pit P ₁ ,
Tracking control from the playback information P ₂ performs (sampled tracking servo) (F 104).

Then, when the sampled tracking servo is executed and the on-track scanning is realized, the segment
Cement synchronization Sector rotation synchronization control of the synchronization or the like is performed (F
105). This rotation synchronization control is realized by finding the head position (header segment H ₁ ) of each sector.
As described above with reference to FIGS.
RO is added to the servo byte SB in the M data segment.
Although the M mark PM _R is provided, no mark pit corresponding to this is provided in the MO data segment and the address area (header segment).
Since the data recording area of the header segment and the ROM data segment is formed by emboss pits,
By detecting the pit form of presence and data recording area of the ROM mark PM _R can determine header segment H _1.

[0033] Here, by the initial start-up sequence is executed, since the revolution synchronization control is on-track state is achieved, when scanning the data pits by the ROM mark PM _R and embossing, the reproduction A sufficient amplitude is obtained as a signal.

That is, as shown in FIG. 3, the reproduced signal by the pit Po located on the track T includes the pits Pq formed with a 1/4 track shift, such as the wobbling pits P ₁ and P ₂ , and 1. / 2 sufficient amplitude compared to the reproduction signal by a pit Ph track deviation is formed is obtained but, ROM mark PM _R and embossed data pits, etc. will correspond to the pit Po. Also,
The guard band GB formed between tracks in the MO data segment corresponds to a pit Ph formed with a shift of 1/2 track. (However, since it is not an isolated pit, the amplitude of the reproduced signal may be slightly larger than that of the pit Ph, but the guard band depth is
(1 / 8λ), which is shallower than the normal pit depth (1 / 4λ), so there is not much difference in practice. )

[0035] In any case, the amplitude level of the ROM mark PM _R and embossed data pits of the reproduction signal obtained when the rotation synchronization control in the present embodiment is larger than the amplitude due always 1/4 track deviation pits Pq, Further, the amplitude level appearing in the reproduced signal due to the influence of the guard band GB is always smaller than the amplitude due to the pit Pq shifted by 1/4 track. Therefore, if the amplitude level by 1/4 track shift pit as a reference (threshold level), will be able to accurately determine the presence or absence of ROM marks PM _R and embossed data pits from the reproduction signal.

In each segment, the ROM mark PM _R
If the presence and absence accurately detect the embossed data pits, for that segment, as described above it can determine whether a header segment H _1, may do this by properly synchronizing control in this embodiment You can do it. Of course, ROM data segment or MO
It is also possible to accurately determine whether the data segment is a data segment, and the determination information can be effectively used as control information for a recording / reproducing operation.

Although there are optical disks without guard bands GB, the presence or absence of guard bands GB in the MO data area has no effect on the detection of the presence of embossed pits according to this method, that is, the accuracy of the header segment discriminating operation. It does not affect. Also, RO
In M data area, although ROM mark PM _R 8 also exists an optical disc which is formed with a long pattern, in this case, the amplitude level of the reproduced signal due to the scanning of the ROM mark PM _R is equivalent to that of an isolated pit since or are those from larger, which also does not affect the accuracy of detection of the ROM mark PM _R by the system of the present embodiment.

The ROM mark PM in the present embodiment described above
_In order to detect the pit form of _R and the data recording area,
In the control data reproducing circuit 7 described above, for example, a detecting circuit is configured as shown in FIG. In this detection circuit, 1 /
The amplitude level of the pits shifted by four tracks is set as the threshold level for determining the presence or absence of the pit.

Reproduction RF for scanning the servo byte SB
The signal is digitized by the A / D converter 40 and the A / D
The output of the converter 40 is input to the registers 41 and 42 and the comparator 44. Input signal to the register 41 is latched by the scan timing of the wobbling pit P ₁ by the control of the timing controller 45, also, it is latched by the scan timing of wobbling pits P ₂ by the input signals are control of the timing controller 45 to the register 42 .

The arithmetic circuit 43 calculates the average value ((w ₁ + w ₂ ) / 2) of the data w ₁ and w ₂ held in the registers 41 and 42 and output at a predetermined timing. 44. Then, the average value ((w ₁ + w ₂ ) / 2) is compared with the output value D ₀ of the A / D converter in the comparator 44, and the comparison result (for example, D ₀ > ((w ₁ +
The signal which becomes “H” in the case of w ₂ ) / 2) is input to one of the input terminals of the AND gates 46 and 47. For the AND gate 46, the timing controller 45 outputs the RO
A control signal which becomes “H” at the scanning timing of the M mark PM _R is supplied to the AND gate 47, and a region following the servo byte SB from the timing controller 45, that is, the address recording region or the data recording region DB is supplied to the AND gate 47.
Is supplied in response to the scanning timing in.

Then, in the servo byte SB, the ROM
When the mark PM _R is scanned or when the emboss pit is scanned in the address recording area or the data recording area DB following the servo byte SB, the amplitude value of the reproduced RF signal, that is, the A / D converter 40 Since the output is larger than the average value of the amplitude levels of the wobbling pits P ₁ and P ₂ , the “H” level is output from the comparator 44.

[0042] Accordingly, ROM mark PM if indeed ROM mark PM _R at the scanning timing of the _R is scanned (ie When a during scanning of ROM data segment), ROM mark PM _R as "H" output of the AND gate 46 Is obtained. If the emboss pit is actually scanned at the scan timing of the data recording area (that is, if the header segment or the ROM data segment is being scanned), the detection signal of the emboss pit is output as the "H" output of the AND gate 47. Is obtained.
That is, if the output of the AND gate 46 is "L" and the output of the AND gate 47 is "H", it can be determined that the segment being scanned is a header segment.

The presence / absence of a pit in such a circuit configuration can be determined by various methods, for example, by a control signal from the timing controller 45, for example, in a word unit or based on a criterion of n pits or more. Can be

Although the embodiment of the present invention has been described above, the circuit configuration in which the recording / reproducing method of the present invention is adopted is as follows.
It is not limited to the one shown in FIG.
Various changes are made. Of course, the specific detection circuit configuration is not limited to FIG.

[0045]

As described above, the optical disk recording / reproducing method of the present invention requires a small amount of data when performing recording / reproducing operations.
At least after the tracking control is executed,
Combination of prescribed mark signal and presence or absence of embossed pit
Discrimination of the head position of the sector based on the
And the result of discrimination of the head position of the sector
The rotation synchronization control is performed using
Recording / reproducing operation using the result of discriminating the type of
Because it is made, there is an effect that it is possible to determine a segment exactly, there is an advantage that particularly allow to run properly synchronizing control by accurate determination of the header segment.

[Brief description of the drawings]

FIG. 1 is a block diagram of a recording / reproducing apparatus to which an embodiment of a recording / reproducing method according to the present invention is applied.

FIG. 2 is a control flowchart at the time of initial startup of a recording / reproducing method according to the embodiment.

FIG. 3 is an explanatory diagram of an amplitude level of a reproduced signal at the time of pit scanning.

FIG. 4 is a block diagram of a pit presence / absence detection circuit according to the present embodiment.

FIG. 5 is an explanatory diagram of a header segment of an optical disc on which a recording / reproducing operation is performed according to the present invention.

FIG. 6 is an explanatory diagram of a ROM data segment of an optical disc on which a recording / reproducing operation is performed according to the present invention.

FIG. 7 is an explanatory diagram of an MO data segment of an optical disc on which a recording / reproducing operation is performed according to the present invention.

FIG. 8 is an explanatory diagram of another example of the ROM data segment of the optical disc on which the recording / reproducing operation is performed according to the present invention.

FIG. 9 is an explanatory diagram of an optical disk.

FIG. 10 is an explanatory diagram of a segment structure.

[Explanation of symbols]

1 disc 3 the optical head 7 control data reproducing circuit 8 system control unit PM _R ROM mark

Claims (1)

(57) [Claims] A track formed concentrically or spirally is divided into a plurality of sectors , and is used for discrimination of a head position of the sector and discrimination of a type of a medium. Specified mark signal and embossed
Is a recording / reproducing method for an optical disc recorded at a predetermined position in the sector, and when performing a recording / reproducing operation, at least after the tracking control is executed, the predetermined mark signal and
Based on the combination of the presence or absence of fine embossed pit performs determination and medium type of the stamp by the head position of the sectors,
A rotation synchronization system using the discrimination result of the head position of the sector.
Control and using the discrimination result of the type of the medium
An optical disk recording / reproducing method which performs a recording / reproducing operation .