JPH1055545A - Optical disk, device for driving the same and its method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stably detect data on an optical disk in question for reproduction only having specifications common to a recordable optical disk by effectively utilizing an area corresponding to an asymmetrical level power control(ALPC) area of the recordable optical disk. SOLUTION: On the subject optical disk 201 with specifications common to the recordable optical disk provided with the ALPC area, provided with a reproduction only area having a reference area provided with a reference embossed pit for detecting the data in a position corresponding to the power control area of the recordable optical disk, a threshold level for detecting the data is detected by obtaining asymmetry information from a regenerative signal in the reference area by a threshold level detecting part 133, and the data is detected from a regenerative signal in the production only area by a data detecting part 132 using this threshold level.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a read-only optical disk having a common specification with a recordable optical disk provided with a power control area for controlling a recording laser power, a drive apparatus and a drive method thereof. About.

[0002]

2. Description of the Related Art Generally, as an optical disc, a read-only RO such as a digital audio disc having a read-only area in which data is recorded by emboss pits is used.
M disk, RAM disk having data recordable area by magneto-optical recording film or phase change recording film, read-only ROM area in which data is recorded by emboss pits, and re-recording of data by magneto-optical (MO) recording film RAM
Various optical discs such as a hybrid disc having an area are known.

In an optical disk system for recording / reproducing various data by scanning concentrically or spirally formed tracks with a laser beam, the optical disk has a constant linear velocity (CLV). The CLV method in which data is recorded / reproduced by rotating the optical disk, or the optical disk having a constant angular velocity (CAV: Constant Angular Velo
CA) that rotates and drives data to the city
A V type is known. Further, in the case of a CAV type disc, the recording density on the outer peripheral side is reduced, so that the transfer speed on the outer peripheral side is made higher than that on the inner peripheral side so that the linear density is the same on the inner and outer peripheral sides. In some cases, a zone CAV method is adopted. In addition, a continuous servo method that performs tracking control using pregrooves that are continuously provided along the track, and a sample that performs tracking control using servo areas that are discretely provided on the track A servo type is known.

[0004] In optical disks, track pitch and linear density are increased in order to enable high-density recording. For example, in a magneto-optical disk, by applying a partial response and actively utilizing intersymbol interference, the linear density is increased to enable high-density recording, and code detection is performed by employing a Viterbi decoding method. I try to improve my ability.

[0005] Furthermore, in a recordable optical disk, it is necessary to scan a track with a laser beam controlled to an appropriate laser power at the time of recording, so that an area for controlling the recording laser power is used for power control ( ALPC: Au
tomatic Laser Power Control) area.

[0006]

On the other hand, a read-only optical disc does not need an ALPC area because information is not recorded. In addition, an area corresponding to the ALPC area of the recordable optical disc is meaninglessly secured.

Accordingly, an object of the present invention is to provide a read-only optical disc having the same specifications as a recordable optical disc and to effectively utilize an area corresponding to the ALPC area of the recordable optical disc. An object of the present invention is to provide an optical disc capable of stably detecting data, a drive device and a drive method thereof.

[0008]

An optical disk according to the present invention has a read-only area having the same specifications as a recordable optical disk having a power control area for controlling a recording laser power. An optical disc having a reference area provided with a reference emboss pit for data detection at a position corresponding to a power control area of the recordable optical disc in the read-only area. .

In the optical disk according to the present invention, for example, asymmetry information is given by the reference emboss pit in the reference area.

The drive apparatus for an optical disk according to the present invention has the same specifications as a recordable optical disk provided with a power control area for controlling a recording laser power. A drive device for an optical disk provided with a read-only area having a reference area provided with a reference emboss pit for data detection at a position corresponding to the power control area of Threshold level detecting means for detecting a threshold level for data detection by obtaining asymmetry information; and data detection for detecting data from a reproduction signal in the reproduction-only area using the threshold level detected by the threshold level detecting means. Means.

Further, the method for driving an optical disk according to the present invention has the same specifications as a recordable optical disk provided with a power control area for controlling a recording laser power, A drive method for an optical disc provided with a read-only area having a reference area provided with a reference emboss pit for data detection at a position corresponding to the power control area, comprising: A threshold level for detecting data is obtained by obtaining asymmetry information, and data is detected from a reproduction signal in the reproduction-only area using the threshold level.

[0012]

Embodiments of the present invention will be described below with reference to the drawings.

First, the format of an optical disk according to the present invention will be described. An optical disc according to the present invention has a read-only area having a common specification with a recordable optical disc having a power control (ALPC: Automatic Laser Power Control) area for controlling a recording laser power. A hybrid type disk having a read-only ROM area and a RAM area in which data can be re-recorded by a magneto-optical (MO) recording film as an optical disk according to the present invention is taken as an example. A description will be given together with the recordable MO disk of the sample servo system. Unless otherwise defined, it is assumed that contents common to both disks are described.

An optical disk according to the present invention is, for example, shown in FIG.
As shown in the figure, one round of the track is divided into 1300 segments (segment 0 to segment 1299), and the segments are classified into an address segment ASEG and a data segment DSEG.

In each track of the address segment ASEG, position information in the radial direction on the disk, ie, a track number, and position information in the tangential direction, ie, a segment number, are recorded in advance by pits. That is, pits are formed when the optical disc is created based on the position information. This address segment ASEG exists every 14 segments, and there are 100 in one track. As shown in FIG. 2, one frame from one address section ASEG to the next address segment ASEG is one frame, and there are 100 frames in one round of the track. 13 segments between two consecutive address segments ASEG are data segments D
SEG. Data segment DSEG is 13 in one lap
There are 00 segments. Each segment is composed of an area for 216 servo clocks and includes a servo area ARs for 24 servo clocks and a data area ARd for 192 servo clocks. Address segment ASEG
In the example, the data area ARd includes an address area ARda and an ALPC area ARdb.

And a ROM in the optical disk.
In the ALPC area ARdb of the area, a reference emboss pit pattern for providing asymmetry information is formed so as to be used as a reference area for data detection.
As the reference emboss pit pattern for providing the asymmetry information, for example, “000100000000011”
000 "is used.

As described above, the ALPC area AR in the ROM area
The ALPC area ARdb is formed as a reference area for data detection by forming a reference emboss pit pattern in the db.
In this optical disk, the asymmetry information can be given to the reproducing system, and the data can be stably detected in the reproducing system.

The servo area AR of the optical disk
FIG. 3 shows a pit pattern in an address segment of a RAM area (Rewitable Zone) and a ROM area (Embossed Zone), and FIG. 4 shows a pit pattern in a data segment. As shown in FIGS. 5A to 5E, the pit pattern of the servo area ARs of the disk is composed of three pits Pa 1, Pb, and Pc each having a length of 2 servo clocks. A focus sample area ARfs having a length of six clocks, which is recorded in advance and separated from each other, is provided.

As described above, the pits P in the servo area ARs
By setting each of a, Pb, and Pc to have a length corresponding to two servo clocks, a portion where a pit is not formed, that is, a mirror portion is reduced, so that a ghost pit or the like generated at the time of disk molding can be hardly generated.
Further, at the time of access, since the RF signal is stably reproduced from the pits Pb and Pc, various servo signals such as a tracking servo signal can be stably generated based on the RF signal reproduced from the pits Pb and Pc. Will be possible. Furthermore, the pits Pa, Pb, and Pc are separated from each other by a predetermined distance or more at the center between the pits Pa, Pb, and Pc, so that the pits Pa, Pb, and Pc are separated from each other.
Data interference between RF signals reproduced from Pc can be extremely reduced. In order to reduce the data interference between the pits, it is desirable that the intervals between the pits Pa, Pb, Pc are separated by 5 servo clocks or more.

The second pit Pb located in the 11-12 clock period and the third pit Pc located in the 16-17 clock period are shifted from the center of the track by ± 1/4 track in the radial direction of the disk. Wobble pits placed at the position, and these pits Pb,
Tracking error information is given by the difference between the amplitude values of the RF signal reproduced from Pc. Further, as will be described later, the phase information of the servo clock is given by the difference between the amplitude values of both shoulders of the RF signal reproduced from these pits Pb and Pc, and the phase information is dependent on the tracking state by adding this phase information. Give no clock phase information.

Further, the first at the beginning of the servo area ARs
The pit Pa has, depending on its position, an address mark ADM indicating that the segment is the address segment ASEG, a first sector mark STM1 indicating that the segment is the head segment of the sector, and a next segment being the head of the sector. , And a segment mark SGM that does not correspond to any of the above.

The first pit Pa is provided when the address mark ADM is located in the period of 3 to 4 clocks as shown in FIG. 5C, and when the first pit Pa is located in the period of 4 to 5 clocks as shown in FIG. First sector mark STM1, E in FIG.
As shown in FIG.
Sector mark STM2. The start position of each sector will be described later. For example, as shown in FIG. 6, the information indicated by the first pit Pa is identified by examining the positions A to D at which the reproduced RF signal has the maximum amplitude value by detecting a maximum difference value, that is, a so-called differential detection method. can do.

Thus, the address mark ADM or the first and second sector marks STM1 and STM2 are formed by the first pit Pa at the beginning of the servo area ARs.
Therefore, the sector number and the track address need not be recorded in sector units.

The address segment ASEG includes:
As shown in FIG. 7, 16-bit track addresses [AM] and [A] are used as radial position information of the disk.
2], [A3], [AL] and its parity [P], an access code ACC, and frame addresses [FM], [F] as tangential position information.
L] are respectively gray-coded and recorded in advance in pits.

In the access code ACC, a 16-bit track address is divided into four bits, and FIG.
Table conversion based on the Gray code table shown in
M = 15 to 12 bits (MSN) to A2 = 11 to 8 bits (2SN), A3 = 7 to 4 bits (3SN), AL
= 3 to 0 bits (LSN) in this order. At this time, only when the least significant bit of the four bits is “1”, a value obtained by taking the one's complement of the next four bits is used. This allows
These access codes change only one pattern between adjacent tracks. The parity codes are grouped according to the bit position of the access code, and each group [15, 11, 7, 3], [1]
4, 10, 6, 2], [13, 9, 5, 1], [12,
[8,4,0]], the result of taking the parity which becomes 1 when the number of bits having the value "1" is even is recorded.

As described above, only when the least significant bit of the four bits is "1", these access codes change by only one pattern between adjacent tracks as a value obtained by taking the complement of one for the next four bits. In the case where the pit representing the upper two-bit gray code and the pit representing the lower two-bit gray code are “0”, which is the shortest distance, for one central clock area, Is the shortest distance and the other is the longest distance "F", the central pit for one clock is formed, so that the central one-clock area is connected to the mirror part continuous in the radial direction. In addition, it is possible to make the flow of the resin uniform at the time of molding the disc, thereby enabling high quality disc molding.

The frame code FRC is obtained by dividing information in the tangential direction of the address segment ASEG, that is, an 8-bit frame address representing a frame number into upper and lower 4 bits, and the upper 4 bits FM.
= 7 to 4 bits (MSN) and lower 4 bits LM = 3 to 0
The bits (MSN) are gray-coded and recorded in the same manner as the access code described above. This frame code can record information of 8 bits, but the value actually exists only in the number 0 to 99 of the address segment ASEG.

Note that the focus sample area ARfs of the servo area ARs is a mirror section, and the focus servo and read power APC (APC: Automatic Power Control) in the optical disk drive.
ol), and used for clamping an RF signal.
It is difficult to accurately specify the positions of various sample pulses for these processes, and fluctuations of ± 0.5 servo clock pitch or less are expected. Therefore, even when this fluctuation is added, the level of the RF signal is modulated by the pits. The mirror section has a space for 6 clocks as a space for sampling with an accurate value without being affected by the above.

As shown in FIG. 8, the data area ARd of the data segment DSEG has a data area AR of 176 to 368 data clocks for recording user data.
d and the prewrite area AR _PR for 4 data clocks and 4
Consisting of post-write area AR _PO of the data clock.
Note that the number of data clocks changes according to the zone. The pre-write area AR _PR includes a RAM area (Rewritable Z).
In the case of one), the distance required for preheating until the disk reaches a stable temperature for data recording after the drive starts laser irradiation and the DC fluctuation due to the birefringence of the MO signal during reproduction, etc. This is provided for use as a clamp area for suppressing the pressure. Since taking compatible format, also in the ROM area (Embossed Zone), the pre-write area AR _PR is provided. In addition, the post-write area AR _PO secures a distance to avoid erasure of recorded data and to avoid data interference caused by the edge of the groove Gr provided in the RAM area (Rewritable Zone) at the time of overwriting. It is provided in order to. This optical disk is bulk erased in one direction at the time of shipment. And, for the above-described pre-write area AR _PR, by recording the same polarity data and bulk erasing direction, data in which the data to pre-write area AR _PR is recorded without being operated correctly by residual heat shortage of media Does not change, so that a stable signal can be reproduced. Also, by recording the same data for four data clocks in the post-write area AR _PO , it is effective to have a data string that is stable at a constant value for decoding from the subsequent data in Viterbi decoding. is there. Further, the ROM area (Embossed Zone) is obtained by deleting the groove Gr.

Here, in a recordable optical disk such as a magneto-optical disk, no pits are formed in advance in a region where data is to be rewritten. Wider than read-only optical discs. Therefore, the data area A
By providing the groove Gr in the portion corresponding to Rd, the number of mirror portions can be reduced, and the adverse effect on the servo pit on the disk molding can be reduced. Groove G
Since r is not used for tracking control, accuracy such as its depth is not required. In this example,
When the wavelength of the laser is λ, the depth is λ / 8.
In the case of a read-only ROM disk, as shown in FIG. 9, an anchor pit Pan having an area for three data clocks is provided at the head of the data area ARd to reduce the number of mirror parts and to increase the servo during disk molding. The adverse effect on the pit can be reduced.

One data sector is shown in FIG. 10 and FIG.
As shown in FIG. 1, 66 bytes of reference data, 2048 bytes of user data (D _{1 to} D ₂₀₄₈ ), 40 bytes of user defined data (F _{1 to} F ₄₀ ), C
RC ₈ bytes (C _{1 to} C ₈ ), ECC 256 bytes (E
_{1,1 to} E _16,16 ).

FIG. 11 shows the reference data 66
The data format of 2352 bytes excluding bytes is shown.

As the reference data, the waveform of the reproduced RF signal is, as shown in FIG.
A 66-byte specific pattern including a T pattern and a 12-byte 2T pattern as one block, four blocks, and a 2-byte all-zero pattern as a margin for setting detected information is recorded. You. The 8T pattern is used for setting a ternary level (high H, medium M, low L) in partial response (1, 1) and data detection by Viterbi decoding, and the 2T pattern is a DC-like pit due to recording power fluctuation or the like. It is used to correct the displacement during reproduction.

In the data area ARd of the data segment DSEG, data other than 66 bytes of the reference data is scrambled. Further, the scrambled data is NRZI converted for each segment and recorded.

This optical disk has a so-called zone C
An AV disk, as shown in FIGS. 13 and 14, a GEP area for 736 tracks from the outer circumference side, a buffer track for two tracks, a control track for five tracks, a buffer track for two tracks, and a buffer track for five tracks Test track, 848 track user zone 0, 864 track user zone 1, 880 track user zone 2, 912 track user zone 3, 944 track user zone 4, 976
User zone 5 for trucks, user zone 6 for 1024 tracks, user zone 7 for 1056 tracks,
User zone 8 for 1120 tracks, User zone 9 for 1184 tracks, User zone 10 for 1216 tracks, User zone 11 for 1296 tracks
User zone 12 for 392 tracks, User zone 13 for 1488 tracks, User zone 14 for 1696 tracks, User zone 15 for 770 tracks
Test track for tracks, buffer track for 2 tracks, control track for 5 tracks, buffer track for 2 tracks, GE for 820 tracks
It consists of a P region.

Here, the number of tracks in a zone is Tz, the number of data sections required for one sector in a certain zone is Dsz, the number of data sections per track is Dt, and the sector is completed for each zone. In order to keep the number of sectors constant, the number of sectors Sz in the zone is Sz = Tz.Dt / Dsz, and Tz = K
The number of tracks may be determined so as to be Dsz. Then, the number of sectors Sz determined by using a value close to the data capacity per zone obtained by dividing the data capacity of the entire disk by the total number of zones as the value of K is allocated from the zone on the outer peripheral side, and the zone is allocated. By determining the data clock frequency so that the recording density of the innermost track does not exceed a predetermined density, all parameters can be obtained. It is assumed that the capacity of one sector is constant. Here, it is 2352 bytes.

In this case, as shown in FIG. 15, when a sector starts from a certain segment and the number of segments constituting one sector ends, the sector is ended. The next sector is started from the next segment instead of the next sector from the surplus bytes.

Thus, a sector starting from segment 0 of a 0-frame code can be always formed at the head of a zone. Further, when considering the provision of a parity sector for a certain number of sectors, the capacity of the parity sector can be made constant by making the number of sectors in each zone uniform.

In the innermost zone, the number of sectors may not be the same as that of the other zones, but may be a fraction, due to the relationship with the recording area. Zones.

In this optical disk, the user zone is divided into 16 zones as described above, and the data bytes included in one segment by the data clock DCK generated by multiplying the servo clock SCK by M / N. The number (byte / seg) and the number of segments per sector (seg / sector) are determined. Note that M corresponds to the clock value in FIG.
4. That is, if the number of servo clocks in the servo area ARs is N and the data clock DCK is M / N times the servo clock SCK, the number of servo clocks SCKseg and the number of data clocks DCKs in one segment are set.
eg, SCKseg = 9N DCKseg = SCKsegM / N. Note that N and M are integers.

Further, as described above, one track is 140
It is divided into 0 segments, and 1300 of them are data segments DSEG. However, since no user data is recorded in the GEP area, 100 segments of 1300 data segments DSEG are used to store GEP information such as media information. It is used as a GEP segment GEPseg to be stored. GEP segment GEPs
eg, as shown in FIG. 16, each address segment A
It is allocated to the data segment at the middle position of the SEG.

Then, the GEP segment GEPseg
As shown in FIG. 17, the GEP area ARgep includes a servo area ARs, a GEP area ARgep, and a blank ARblk. The GEP area ARgep is gray-coded in the same manner as the access code ACC of the address segment ASEG. Pieces of 4-bit data, that is,
[GEPH], [GEP2], [GEP3], [GEP
L] and its parity [P], a GEP code, and page numbers [PNH] and [PNL] are recorded in pits, respectively.

A parity [P] is added to the GEP code so that an error can be detected. Also,
The page numbers [PNH] and [PNL] are added,
A plurality of media information can be given as GEP information. The above page number [PN
H] and [PNL] are [P
By recording the same information in [NH] and [PNL],
Can be more robust to errors.

In the GEP area ARgep, as shown in FIG. 18, the last one digit of the address (frame number) recorded in the address segment ASEG matches the page number of the GEP segment GEPseg. By arranging each GEP segment GEPseg in the address segment ASEP, it is possible to eliminate reading errors of the frame number of the address segment ASEG and the page number of the GEP segment GEPseg. Further, since one track has 100 frames, by repeatedly recording 10 pages, that is, 10 types of GEP information ten times, it is possible to reduce reading errors of each of the 10 types of GEP information.

Here, the GEP segment GEPse
In the GEP information recorded in g, the page number 0 is information indicating media information / media type, and bit 15
The information indicating the physical format of the media such as the presence or absence of a groove and the presence or absence of a sector mark is given by .about.14.
Information indicating the type of the medium such as O and ROM is given, and generation information of the medium is given by bits 3-0. In the GEP information of page number 1, bits 15 to 8 give data information indicating the sample servo system, logical CAV, NRZI coding or the like, and bits 7 to 0 give information indicating an error correction format. Also, the GE of page number 2
The P information gives information indicating the physical address of the control track on the outer peripheral side in bits 15 to 0. The GEP information of page number 3 gives information indicating the physical address of the control track on the inner peripheral side in bits 15 to 0.
The GEP information of page number 4 gives information indicating the maximum read power in bits 15 to 8. Note that bit 7
〜0 is preliminary information. G of page number 5
In the EP information, bits 15 to 8 give information indicating the number of clocks of the outer peripheral control track, that is, the above-described clock value M, and bits 7 to 0 give information indicating the number of segments per sector. In the GEP information of page number 6, bits 15 to 8 give information indicating the number of clocks of the inner circumference control track, and bits 7 to 0 give information indicating the number of segments per sector. In the GEP information of page number 7, information indicating the number of clocks per segment is given by bits 15 to 8, and information indicating the number of servo clocks per segment is given by bits 7 to 0. The GEP information of page number 8 gives information indicating the number of segments per track in bits 15-0. Further, the GEP information of page number 9 gives information indicating the number of address segments per track in bits 15 to 8, and bits 7 to 0 are preliminary information.

Next, the control track includes the above-mentioned 20 bytes of GEP information, 10 bytes of media information such as laser wavelength and reflectance, track pitch, the number of bytes of various physical block addresses and data fields, and the number of bytes of various areas. 70 bytes of system information such as the number of data clocks and the number of zones;
0-byte band information is recorded.

In the control track, information A (A = the number of segments / track) indicating the number of segments per track (1 byte), information B indicating the start track number (2 bytes) of each zone, and the total track of each zone By recording information indicating the number (2 bytes) and information D (D = the number of segments / sector) indicating the number of segments per sector (1 byte), for example, the physical Track addresses and physical segment addresses can be calculated.

That is, the serial sector address is converted into a zone number E and an offset number F using a table, and from the offset number F, F × D / A = G (quotient). . . By performing the operation of H (remainder), the physical track address = B + G the physical segment address = H, and the physical track address and the physical segment address in the zone can be calculated.

An optical disk drive for recording / reproducing data by using an optical disk having such a format as a recording medium comprises, for example, a control circuit block 100 and a disk drive 200 as shown in FIG.

In this optical disk drive, the system controller 101 provided in the control circuit block 100 is shown in a state where the optical disk 201 is mounted on the spindle motor 203 by the loading mechanism 202 provided in the disk drive 200. When the optical disk 201 is loaded in response to a request from the host computer or when the automatic spin-up mode is set, an instruction is issued to the spindle driver 204 to rotate the spindle motor 203. Then, when the spindle motor 203 reaches a predetermined number of revolutions, the spindle driver 204 notifies the system controller 101 that the rotation has been stabilized.
During this time, the system controller 101 operates the optical pickup 205 by the pickup driver 207.
Is moved to the vicinity of the outer peripheral end or the inner peripheral end of the optical disk 201, and the beam spot is moved to the recording area,
For example, it is located in a GEP area outside the range from １５15 to １５15.
If the focus is pulled in the recording area, data may be erased accidentally in the case of a magneto-optical disk with high sensitivity.
By performing focus pulling in a region where data is formed by pits such as a region, erroneous erasure of data is prevented.

Here, the system controller 101
Indicates whether the optical disk 201 is a read-only optical disk or a recordable magneto-optical disk based on the media information reproduced from the GEP area,
It is possible to determine whether the disc is a hybrid disc having an AM area. Since the GEP area records gray-coded media information in the same format as the address information, the address information and the media information can be read and determined in the same manner. Moreover, since the media information that is gray-coded is recorded in the GEP areas of a plurality of tracks, the media information can be reliably read even if the position control of the beam spot is incorrect.

Then, the system controller 101
When the spindle motor 203 rotates at a constant speed and the optical pickup 205 moves, for example, near the outer peripheral end, the bias current LDB of the laser diode provided in the optical pickup 205 is supplied to the laser drive circuit 206 via the D / A converter 107. Is set, and a command is issued to a servo system timing generator (STG) 108 for controlling on / off of the laser diode so as to emit the laser. This bias current is set to a high level during recording,
Set to low level during playback. When a laser beam is emitted from the laser diode, the laser beam enters a photodetector provided in the optical pickup 205, and a detection output by the photodetector is transmitted to the first and second clamp circuits 110 and 111 via the RF amplifier 209. Is entered.

Next, the system controller 101 drives the focus actuator of the optical pickup 205 up and down by passing a current through the focus drive circuit of the pickup driver 207 to set a focus search state. At this time, the laser beam reflected from the optical disk 201 is detected by a photodetector, and a focus error signal based on a detection output by the photodetector is fed back from the RF amplifier 209 to a focus drive circuit via a servo circuit (not shown).
Construct a servo loop for focus control.

[0054] Focus control is stable to the RF signal from the pre-write area AR _PR above obtained by the RF amplifier 209 from a detection output by said photodetector (R
OM area or ROM disk) or MO signal (RAM
Area or the data area of the MO disk), the amplitude thereof becomes constant to some extent, and the first and second clamp circuits 11
0, 111, and then clamped to an appropriate potential by the first and second A / D converters 112, 113.
D conversion is performed. By performing clamping using the prewrite area AR _PR , a stable signal can be obtained, and an accurate clamping operation can be performed.

The clock at the time of the servo pull-in operation is the frequency of the servo system clock generation (SPLL) circuit 114 in the free-run state. The timing pulse for clamping is also the servo clock signal SCK of this free-run frequency.
Is divided by a predetermined value.

The SPLL circuit 114 checks the pit pattern by checking the amplitude difference between the sampling values of the RF signal, and searches for the same pattern as the pit row in a predetermined servo area. When a pattern is found, a window is opened at the timing when the next pattern should appear, that is, in the servo area of the next frame, and it is checked again whether the pattern matches. If this operation is confirmed a certain number of times in succession, it is considered that the phase of the servo clock SCK generated by the SPLL circuit 114 is locked to the phase of rotation of the optical disk. Here, as shown in FIG. 20, for example, the servo clock SCK is separated from the center point of the reproduced RF signal waveform with respect to the wobble pit Pb sampled at each of the timings t _b1 , t _b2 , t _c1 and t _c2 by one servo clock before and after. Sampling data b1 and b2 at the sampling points on both shoulders and sampling data b on the sampling points on both shoulders one servo clock before and after the center point of the reproduced RF signal waveform for wobble pit Pc.
From 1 and b2, phase error data = [(b2-b1) + (c2-c1)]
By the calculation of / 2, the phase error between the servo clock SCK and the servo data can be detected. in this way,
The phase information is obtained by taking the amplitude difference between the shoulders of the wobble pits Pb and Pc in the servo area. Furthermore, by adding the phase information obtained from both of the two wobble pits, the gain fluctuation caused by the amplitude change due to the tracking position is absorbed.

When the SPLL circuit 114 is locked, the optical disk drive is driven by the optical pickup 2 in segment units.
Since the scanning position 05 can be recognized, the position of the first pit Pa can also be recognized, and a window is opened at the four positions A, B, C, and D shown in FIG. A position where the amplitude becomes maximum is searched for in the RF signals sampled by B, C, and D. When the result is the position A, it is an address mark ADM, and it is possible to recognize that this segment is an address segment and the beginning of a frame. Can be taken. Since one frame is composed of 14 segments, a window is opened every 14 segments, and when it can be recognized continuously as an address mark, it is determined that the frame synchronization is locked.

When the frame is synchronized, the position where the address is recorded can be recognized, so that the address decoder (A
DEC) 116 decodes the access code ACC and the frame code FRC. This ADEC116
In this case, a pattern that is gray-coded four bits at a time is decoded by checking the match with the gray code table shown in FIG. Here, the above ADEC1
In 16, the reproduction R of each position a, b, c, d shown in FIG.
The F signal is sampled, and the position where the amplitude value becomes maximum is determined by a maximum difference value detection method (differential detection method). Similarly, the reproduced RF signal at each of the positions e, f, g, and h shown in FIG. 6 is sampled, the position where the amplitude value is maximized is determined, and decoding is performed using the combination of these and the gray code table. The track addresses [AM] to [AL], parity [P], frame addresses [FM] and [FL] are decoded by the above method, and the decoding result is stored in a register. When these data are determined, the system controller 101 can detect the current position of the optical pickup 205 by reading out the decoding result stored in this register. However, instead of simply looking for a match, because the whole is gray coded, not just 4 bits,
The comparison with the inverted or non-inverted table is performed depending on whether the LSB of the upper 4 bits is “1” or “0”. Here, the first decoded frame code FRC is loaded into the frame counter, and a numerical value obtained by incrementing the frame counter for each frame is compared with the actual reproduced frame code FRC to continuously match. When it is confirmed that the rotation has been synchronized. Thereafter, the value obtained by the frame counter is used as the frame code FRC as the system controller 1
By returning to 01, the frame position is not erroneously recognized even if there are some defects or the like.

The GEP decoder 115 decodes the GEP information in the same manner as the track address and the frame code FRC. However, the contents of the GEP area ARgep can be confirmed by reading out the decoding result stored in the register not by the address segment but by the GEP segment GEPseg in which the GEP information is recorded.

Then, the system controller 101
As shown in the flowchart of FIG. 21, the media type is determined based on the GEP information obtained by the GEP decoder 115, and in the case of a read-only ROM disk, the flag is set to “0” and the data restart is performed. In the case of a recordable RAM disk, set the flag to “1”,
Further, for a hybrid disk having a read-only ROM area and a RAM area, a flag "0" is set in the ROM area and a flag "1" is set in the RAM area for each area.

At the time of seek, the system controller 101 calculates the moving speed of the optical pickup 205 while reading the previously coded track address, and outputs the moving speed of the optical pickup 205 via the slide driving circuit of the pickup driver 207. By controlling the slide motor, the optical pickup 205 is moved to a target track.

When the optical pickup 205 arrives at the target track, the tracking operation starts. As described above, the tracking error signal TE is obtained by taking the difference between the amplitude values of the RF signals reproduced from the two wobble pits in the servo area. By returning the tracking control data obtained by digitally filtering this value to the pickup driver 207,
Configure a servo loop for tracking control.

The head position of the target sector is detected while tracking is performed. As described above, the segment which is the head of each sector and the segment immediately before it have the sector marks STM1 and STM2.
1, STM2 are the four positions A, shown in FIG.
A window is opened in B, C, D, and these four positions A,
When the position having the maximum amplitude in the RF signal sampled by B, C, and D is B, it indicates the head segment of the sector, and when it is C, it is the segment immediately before the head of the sector. Indicates that there is. Basically, the leading segment of a sector is determined by converting a sector address given by the host computer into a physical sector and calculating which track and which segment the sector belongs to. The empirical probability that a sector mark will be defective at the same time is 10 ^-10
The probability of occurrence of bad sectors due to this is extremely small.

A data clock generation (DPLL) circuit 117 generates a data clock DCK which is M / N times the frame-synchronized servo clock SCK obtained by the SPLL circuit 114, and pre-processes the data clock DCK. Encoder 120 and laser drive circuit 2
06. The data clock DCK generated by the data clock generation (DPLL) circuit 117 is phase-compensated based on the phase in the read clock phase compensation area of the reproduction RF signal of the reference data shown in FIG. The data clock generation (DP
LL) Data clock DC generated by circuit 117
K is supplied to an A / D converter 113, an equalizer 131, a data detection unit 132, a threshold detection unit 133, and the like of a data reproduction system via a delay circuit 130.

The pre-encoder 120 modulates the recording data Din supplied to the input terminal 100A in the recording mode into NRZI sequence data synchronized with the data clock DCK. At this time, the initial value is set to “0” for each segment. Then, the modulation signal WDAT is supplied to the magnetic head 211 via the magnetic head drive circuit 210. The magnetic head 211 has a modulation signal WDAT.
A magnetic field is generated in accordance with the above condition, and this magnetic field is heated to the Curie temperature by the laser beam emitted from the laser diode of the optical pickup 205.
01 to the data area ARd of NRZ
Record the I-series data.

The laser drive circuit 206 for driving the laser diode of the optical pickup 205 has reproduction power setting data provided by the reproduction drive power setting unit 103 for setting the reproduction drive power and recording drive power setting for setting the recording drive power. The recording power setting data provided by the multiplexer 104 is supplied from the multiplexer 104 to the D / A
It is supplied via a converter 107.

In the recording mode, at the timing when the optical pickup 205 moves from the servo area to the prewrite area of the data area, the multiplexer of the optical pickup 205 is switched from reproduction driving power to recording driving power. 10
4 is the servo system timing generator (STG) 1
08.

In the reproducing operation mode, the reproduced RF signal output from the optical pickup 205 via the RF amplifier 209 is clamped to an appropriate potential by the clamp circuit 111 and then the A / D converter 113 outputs
/ D converted and supplied to the equalizer 131.

The equalizer 131 has a pass frequency characteristic equal to the COS characteristic as shown in FIG. 22A, and a digital signal for adjusting the reproduced RF signal to the partial response (1, 1) as shown in FIG. Filter.

The reproduction RF from the equalizer 131
The data detection unit 132 to which the signal is supplied decodes the data of the partial response class 1-PR (1, 1) by NRZI sequence data by Viterbi decoding. Also,
The threshold detection unit 133 is provided with the data detection unit 13.
The threshold for decoding given to 2
Detect from signal.

The data detecting section 132 and the threshold detecting section 133 repeatedly perform processing operations as shown in the flowcharts of FIGS.

That is, the threshold detector 13
3 has a defect check function.
The operation shown in FIG.

First, it is determined whether the area is the ROM area or the RAM area based on the flag set by the system controller 101 (step 101).

In the case of the ROM area, the above A
Center level C of reproduced RF signal in LPC area ARdb
₀ is detected (step 102).

In the case of the RAM area or after the processing in step 102, as shown in FIG. 26, the low level L ₁ , L ₂ and the high level H ₁ , of H ₂ for sampling (step 103).

Next, the sampled low level L ₁ , L ₂ and high level H ₁ , H ₂ are checked for defects, and appropriate low levels L ₁ , L ₂ and high level H ₁ , H ₁ , H ₁ , H ₁ , H ₁ , H ₁ , H ₁ , H ₁ , H ₁ , H ₁ , Average values L ₀ and H ₀ of each level are obtained using only H ₂ (step 10).
4). For example, when the low levels L ₁ and L ₂ and the high levels H ₁ and H ₂ are all appropriate, L ₀ = (L ₁ + L ₂ ) / 2 H ₀ = (H ₁ + H ₂ ) / 2. low level L _1, average value of L ₂ L ₀ and the high level H _1, average value H ₀ of the H ₂ is determined.

Next, the system controller 10
Whether the area is a ROM area or a RAM area is determined based on the flag set by 1 (step 105).

If the data is in the ROM area, the reproduction R of the ALPC area ARdb obtained in step 102 is performed.
Using the center level C ₀ of the F signal and the respective average values L ₀ and H ₀ obtained in step 104, CENTER = C ₀ SH = C ₀ + (H ₀ −L ₀ ) / 4 SL = C ₀ - by _{(H 0 -L 0) / 4} , calculating the center level cENTER and lower threshold level SL and the upper threshold level SH (step 106). As described above, asymmetry information is obtained by using the ALPC area ARdb as a reference area for detecting data in which a reference emboss pit pattern is formed, and a center level CENTER and a lower threshold level suitable for decoding a ROM area. SL and the upper threshold level SH can be calculated.

If the area is a RAM area, CENTER = (H ₀ + L ₀ ) / 2 SH = C ₀ + (H ₀ −) using the respective average values L ₀ and H ₀ obtained in step 104. _{L 0) / 4 SL = C} 0 - by _{(H 0 -L 0) / 4} , calculating the center level cENTER and lower threshold level SL and the upper threshold level SH (step 107).

Then, the data detecting section 132
4 and FIG. 25 are performed.

That is, first, an initialization process for setting STAT _k = 3 is performed (step 108).

Further, it is set that A _k = B _k -CENTER (step 109).

Next, it is determined whether or not STAT _k = 3 (step 110). When STAT _k = 3, TH = 0, TL = SL, and R _k = A _k (step 111).

When STAT _k = 3 is not satisfied, ST
It is determined whether or not AT _k = 2 (step 11)
2). If STAT _k = 2, then TH = S
H, TL = 0, and R _k = A _k (step 113).

When STAT _k = 2, TH
It is determined whether or not = 0 (step 114). When TH = 0, TH = SH, TL = 0, R
_k = -R _k to (step 115). Also, TH = 0
If not, set TH = 0, TL = SL, and R _k = −R _k (step 116).

The above steps 109 to 116
The threshold level T for determining the state at time k + 1 based on the state STAT _k at time k
Determine the values of H, TL and R _k .

Next, it is determined whether or not (A _{k + 1} + R _k )> TH (step 117). And (A _{k + 1} +
If R _k )> TH, then STAT _{k + 1} = 1 (step 118).

If (A _{k + 1} + R _k )> TH is not satisfied, it is determined whether (A _{k + 1} + R _k )> TL is satisfied (step 119). Then, (A _{k + 1} + R _k )> TL
, STAT _{k + 1} = 3 (step 1
20). If (A _{k + 1} + R _k )> TL is not satisfied, STAT _{k + 1} = 2 is set (step 121).

The above steps 117 to 121
, The threshold levels TH, TL and R _k
Is used to determine the state STAT _{k + 1} at time k + 1.

Next, it is determined whether the above-described state determination processing for one segment has been completed (step 1).
22). When the processing is not completed, k =
After setting k + 1 (step 123), the above-described step 1
Returning to step 09, the above processing is repeated.

The data in the state at each time is stored and held in a RAM or the like, and is used for decoding to NRZI data.

Then, when the state determination processing for one segment has been completed in step 122, decoding processing to NRZI data is performed in the following procedure.

First, it is determined whether or not STAT _k = 3 (step 124). When STAT _k = 3, bk-1 = 0, that is, the bit data b _k-1 at time k-1 is set to 0 (step 125).

If STAT _k = 3, S
It is determined whether or not TAT _k = 1 (step 126). When STAT _k = 1, b _k-1 = 1, that is, the bit data b _k-1 at time k-1 is set to 1 (step 127).

When STAT _k = 1, b
It is determined whether or not _k = 0, that is, the bit data b _{k at} time k is 0 (step 128). And b _k = 0
If b _k−1 = 1, that is, the bit data b _k−1 at time k−1 is set to 1 (step 129). Also,
When b _k = 0 is not satisfied, b _k−1 = 0, that is, time k−
The bit data b _k-1 of _{1 is set} to 0 (step 13)
0).

The above steps 124 to 130
, The bit data b _k−1 at time k−1 is converted to NR
Convert to Z data.

Next, it is determined whether or not the conversion process for one segment has been completed (step 131). If the processing has not been completed, k is set to k-1 (step 132), and the process returns to step 124 to repeat the above processing.

The bit data at each time is stored and held in a RAM or the like, and is used for decoding into NRZI data.

Then, when the conversion process for one segment has been completed in step 131, the decoding process to NRZI data is performed in the following procedure.

First, the bit data b _k at time k is _converted into b _k =
It is calculated by b _k + b _k−1 (step 133). The addition in this case is the addition of mod2.

Next, it is determined whether the conversion process for one segment has been completed (step 134). If the processing has not been completed, k = k + 1 is set (step 135), and the process returns to step 133 to repeat the above processing.

If the conversion process for one segment has been completed in step 135, 1
It is determined whether the conversion process for the sector has been completed (step 136). If the processing has not been completed, the above-described processing is repeated for the sector following step 101 described above.

In this optical disk drive device, the threshold detector 133 detects the optical disk 201 using the ALPC area ARdb as a reference area for detecting data in which a reference emboss pit pattern is formed as described above. Since the asymmetry information is obtained from the ALPC area ARdb and the center level CENTER, the lower threshold level SL, and the upper threshold level SH suitable for decoding the ROM area are calculated, the ROM of the optical disk 201 is read by the data detection unit 132.
Since data is detected from the reproduction signal of the area, the data can be detected stably.

[0104]

The optical disk according to the present invention is an optical disk provided with a read-only area having the same specifications as a recordable optical disk provided with a power control area for controlling a recording laser power. The reference emboss pit for data detection is provided at a position corresponding to the power control area of the recordable optical disc in the read-only area, so that the reference emboss pit of the reference area is provided. The pits can provide, for example, asymmetry information to the reproduction system, and the reproduction system can detect data stably.

The drive apparatus for an optical disk according to the present invention has the same specifications as a writable optical disk provided with a power control area for controlling a recording laser power. When detecting data from an optical disk provided with a read-only area having a reference area provided with reference emboss pits for data detection at a position corresponding to the power control area, the threshold level detection means detects the data in the reference area. The asymmetry information is obtained from the reproduced signal to detect a threshold level for data detection, and data is detected from the reproduced signal in the reproduction-only area by the data detecting means using the threshold level, so that the data is detected stably. be able to.

Further, in the method for driving an optical disk according to the present invention, asymmetry information is obtained from a reproduction signal in a reference area of an optical disk, a threshold level for data detection is detected, and data is reproduced from a reproduction signal in a reproduction-only area. It can be detected stably.

Therefore, according to the present invention, a read-only optical disc having the same specifications as a recordable optical disc, and effectively utilizing the area corresponding to the ALPC area of the recordable optical disc. In addition, it is possible to provide an optical disk capable of stably detecting data, a driving device and a driving method thereof.

[Brief description of the drawings]

FIG. 1 is a diagram showing a segment structure of an optical disc according to the present invention.

FIG. 2 is a diagram showing a track structure of the optical disc.

FIG. 3 is a diagram showing a pit pattern of a servo area in an address segment in a RAM area and a ROM area of the optical disk.

FIG. 4 is a diagram showing a pit pattern of a servo area in a data segment in a RAM area and a ROM area of the optical disk.

FIG. 5 is a diagram showing a pit pattern in a servo area of an MO disk having the same specifications as the optical disk.

FIG. 6 is a diagram for explaining a method of detecting a first pit in a servo area of the optical disk.

FIG. 7 is a diagram showing a configuration of an address segment of the optical disc.

FIG. 8 is a diagram showing a configuration of a data segment of the optical disc.

FIG. 9 is a diagram showing a format near a servo area in a ROM disk having the same specifications as the optical disk.

FIG. 10 is a diagram showing a configuration of one data sector on the optical disk.

FIG. 11 is a diagram showing a data format of the optical disk excluding reference data of a data sector.

FIG. 12 is a diagram showing waveforms of reference data and a reproduction RF signal thereof in the optical disc.

FIG. 13 is a diagram showing setting parameters for area division on the optical disc.

FIG. 14 is a diagram showing a state of area division on the optical disk.

FIG. 15 is a diagram showing a format of a data sector in the optical disk.

FIG. 16 is a diagram showing an arrangement of GEP segments on the optical disc.

FIG. 17 is a diagram showing a configuration of a GEP segment in the optical disc.

FIG. 18 is a diagram showing a relationship between a page number of a GEP segment and a frame number of an address segment on the optical disc.

FIG. 19 is a block diagram showing a configuration of an optical disk drive according to the present invention.

FIG. 20 is a diagram showing sampling points for extracting clock information from a reproduced RF signal of a wobble pit in the optical disk drive.

FIG. 21 is a flowchart showing a medium discrimination process in the optical disc drive.

FIG. 22 is a diagram showing characteristics of an equalizer in the optical disk drive.

FIG. 23 is a flowchart showing the operation of a threshold detecting unit in the optical disk drive.

FIG. 24 is a flowchart showing a part of the operation of a data detection unit in the optical disk drive.

FIG. 25 is a flowchart showing another part of the operation of the data detection unit in the optical disk drive.

FIG. 26 is a diagram showing a sampling timing of a reproduction RF signal of reference data by a threshold detector in the optical disk drive.

[Explanation of symbols]

101 system controller, 115 GEP decoder, 132 data detector, 133 threshold detector, 201 optical disk, 205 optical pickup

Claims (4)

[Claims] An optical disc provided with a read-only area having a common specification with a recordable optical disc provided with a power control area for controlling a recording laser power, wherein the read-only area An optical disc having a reference area provided with a reference emboss pit for data detection at a position corresponding to the power control area of the recordable optical disc. 2. The optical disk according to claim 1, wherein the reference emboss pits in the reference area provide asymmetry information. 3. A recordable optical disc provided with a power control area for controlling a recording laser power has the same specification as a recordable optical disc, and data is stored at a position corresponding to the power control area of the recordable optical disc. What is claimed is: 1. A drive apparatus for an optical disk, comprising: a read-only area having a reference area provided with a reference emboss pit for detection; An optical disc comprising: threshold level detecting means for detecting a level; and data detecting means for detecting data from a reproduction signal in the reproduction-only area using the threshold level detected by the threshold level detecting means. Drive. 4. A recordable optical disc provided with a power control area for controlling a recording laser power has the same specification as a recordable optical disc, and data is stored at a position corresponding to the power control area of the recordable optical disc. What is claimed is: 1. A method for driving an optical disk, comprising: a read-only area having a reference area provided with a reference emboss pit for detection, comprising: A method for driving an optical disk, comprising: detecting a level; and detecting data from a reproduction signal in the reproduction-only area using the threshold level.