JP2788789B2 - optical disk - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an optical disc and an optical disc recording / reproducing apparatus. More specifically, the present invention relates to an optical disk in which an information pit string of a sector address is wobbled and arranged between a land track and a groove track, and an optical disk recording / reproducing apparatus using the optical disk.

BACKGROUND ART Optical discs have excellent interchangeability and random access properties,
The range of applications in various information equipment fields such as personal computers is expanding more and more, and accordingly, the demand for an increase in the recording capacity of an optical disk is further increasing. Since a rewritable optical disk requires management in units of sectors for recording and reproducing data, a guide groove for tracking control is formed at the time of manufacturing the disk, and sector address information is often formed as pits. In rewritable optical disks that are currently in widespread use, disk-shaped substrates have irregularities of 1 to 1.6 μm (each about 50% width).
Groove track is formed in a spiral shape, and a recording material (in the case of a phase change optical disc, G
e, Sb, Te, etc.) are formed by a method such as sputtering. The disk substrate is copied in large quantities as a substrate of polycarbonate or the like by using a stamper created based on a master in which pits such as concave grooves and sector addresses are cut by irradiation of a light beam. On the optical disc having the above structure, a light beam is irradiated at a predetermined recording power to one of a concave track and a convex track, and information is recorded by forming a mark on a recording film. A light beam is applied to either the concave track or the convex track with the reproducing power of, and the information is reproduced by detecting the reflected light from the recording film.

2. Description of the Related Art In recent years, the capacity of information data handled in various fields has been further increased, and an increase in the capacity of optical discs is desired. The recording density can be increased by sandwiching the width of each track (hereinafter referred to as the track pitch). However, if it is attempted to achieve a recording density that is about twice the conventional recording density, the track pitch is reduced to the conventional track pitch. 1 /
Although it is necessary to make the track pitch twice as large, it is very difficult in terms of manufacturing method to create a stamper with concave and convex tracks having half the track pitch with a stable width and duplicate the disk. On the other hand, there has been proposed a method of increasing the recording density by recording and reproducing information on both the concave track and the convex track. According to this method, it is possible to realize a recording density twice as high as the conventional recording density without changing the width of the uneven track.

For an optical disc on which information is recorded on both concave and convex tracks, it is necessary to form two addresses or concave tracks at the same time if a sector address for identifying a sector is separately provided for each track. Therefore, two or more laser beams are required, and a complicated device is required. Therefore, an intermediate addressing method has been proposed in which an address is formed so as to extend over both a convex track and a concave track of an optical disk (Japanese Patent Laid-Open No. 6-1764).
04). In this method, each address on the disk is provided with a width similar to that of the concave track centering on the boundary between the convex track and the concave track, and the same address is shared by the concave track and the convex track. I do. This allows
Cutting of the master is easy. However, in this case, there are two tracks for the same address as viewed from the recording / reproducing apparatus, and it is necessary to clearly distinguish them by some method.

Hereinafter, a conventional optical disk and an optical disk recording / reproducing apparatus based on the intermediate address method will be described with reference to the drawings.

FIG. 38 is a conceptual diagram of a conventional optical disk having a sector configuration. In FIG. 38, reference numeral 200 denotes a disk, 201 denotes a track, 202 denotes a sector, 203 denotes a sector address area, and 204 denotes a data area. FIG. 39 is an enlarged view of a sector address area and is a schematic view of a conventional intermediate address. In FIG. 39, 206 is an address pit, 207 is a recording mark, 208 is a group track, 209 is a land track, and 210 is a light spot.

Here, the group track 208 and the land track 209 have the same track pitch Tp, and
206 is centered at Tp / 2 from the center of groove track 208
Only in the radial direction of the disk.

FIG. 40 is a block diagram of conventional tracking control and signal processing for reading a signal on an optical disk.

200 is a disk, 201 is a track, 210 is a light spot, and 211 is a disk motor for rotating the disk 200. An optical head 212 optically reproduces a signal on the disk 200, a semiconductor laser 213, a collimating lens 214,
215 objective lens, 216 half mirror, 217 light receiving section, 2
Consists of 18 actuators. 220 is the light spot 210
A tracking error signal detecting unit for detecting a tracking error signal indicating the amount of displacement in the radial direction between the track 201 and the track 201. The tracking error signal detecting unit includes a differential circuit 221 and an LPF (low-pass filter) 222. 223 is a phase compensation unit that generates a drive signal for driving the optical head from the tracking error signal,
224 is an actuator in the optical head 212 based on the drive signal.
The head drive unit drives the 218. 225 is an addition circuit for the signal from the light receiving unit 217, 226 is a waveform equivalent unit for preventing intersymbol interference of the reproduced signal, 227 is a data slice unit for binarizing the reproduced signal at a predetermined slice level, and 228 is a binarized signal. PLL (Phase Locked Loop) that generates a clock synchronized with
229 is an AM detector for detecting an AM (Address Mark), 230 is a demodulator for demodulating a reproduced signal, 231 is a switch for separating the demodulated signal into data and address, and 232 is a CRUC for discriminating an error of the address signal. (Cyclic Redundancy Check) determination unit 233 is an error correction unit that performs error correction of the data signal. Reference numeral 234 denotes an address reproducing unit composed of 225 to 232. CRC is an error detection code generated from an address number and an ID number.

First, the focus direction (focus direction) of the light spot 210
Is performed, but description of general focus control is omitted.

Hereinafter, the tracking control operation will be described. The laser beam emitted from the semiconductor laser 213 is collimated by a collimator lens 214.
The light is converted into a parallel light and is focused on the disk 200 via the objective lens 215. The laser beam reflected by the disk 200 returns to the light receiving units 217a and 217b via the half mirror 216, and a light amount distribution determined by a relative position between the light spot 210 and the track 201 on the disk is detected as an electric signal. When the light receiving units 217a and 217b are divided into two parts, the difference between the light receiving units 217a and 217b is detected by the differential circuit 221 and the low frequency band of the differential signal is converted to LPF2
The tracking error signal is detected by taking out at 22. In order for the light spot 210 to follow the track 201, a drive signal is generated by the phase compensator 223 such that the tracking error signal becomes 0 (the light amount distributions of the light receivers 217a and 217b are equal), and the drive signal is generated according to the drive signal. This is realized by moving the actuator 218 by the bed driving unit 224 and controlling the position of the objective lens 215.

On the other hand, when the light spot 210 follows the track 201, the light interferes with the recording mark 207 and the address pit 206 of the track, and the amount of reflected light decreases, and the output of the light receiving unit 217 decreases. Because of the increase, the output of the light receiving unit 217 increases. The total amount of light output from the light-receiving unit corresponding to the recording mark 207 and the address pit 206 is obtained by an adding circuit 225 and passed through a waveform equalizing unit 226 to a data slice unit.
In 227, binarization is performed at a predetermined slice level, "0",
It is converted into a signal string of “1”. Data and a read clock are extracted by the PLL 228 from the binary signal. Demodulator 230
Then, the demodulated and recorded data is demodulated and converted into a data format that can be processed externally. If the demodulated data is a signal in the data area, the error correction unit 233 corrects the data error to obtain a data signal. On the other hand, when the AM detection unit 229 detects the AM signal for identifying the address portion from the signal sequence constantly output from the PLL 228, the switching unit 231 is switched, and the demodulated data is processed as the address signal. The CRC determination unit 232 determines whether there is an error in the read address signal, and if there is no error, outputs the address signal as address data.

FIG. 41 shows a state of a reproduction signal (RF signal) and a tracking error signal (TE signal) when the light spot 210 passes through the sector address area 203 in the above configuration.
In the data area 204, the light spot 210 is located at the center of the track, but immediately after entering the sector address area 203, a sharp displacement occurs between the light spot 210 and the address pit 206, so that the level of the TE signal greatly changes. Light spot
The 210 cannot suddenly follow the address pit 206, but gradually moves toward the address pit 206 as shown by a broken line. However, since the sector address area 203 is short, the light spot 210
Becomes the data area 205 which is a groove before completely following the address pit 206, and the tracking control is performed so that the off-track Xadr state is eliminated. Further, since a part of the light spot 210 covers the address pit 206, an RF signal as shown in FIG. 41 is obtained. The RF signal amplitude Aadr changes depending on the distance between the light spot 210 and the address pit 206.
In other words, Aadr decreases as the distance increases, and Aa decreases as the distance approaches
dr grows.

However, according to the sector address of the configuration as shown in FIG. 39, when the center of the light spot is shifted from the center of the track in the data area, the distance between the light spot and the address pit also changes in the sector address area. Therefore, if the light spot is closer to the address pit, the amplitude of the reproduced signal in the address pit area is larger. However, if the light spot is closer to the address pit, the reproduced signal in the address pit portion is larger. The problem is that the amplitude of the address becomes small and the address reading becomes poor.

Also, in the sector address area, since the light spot and the address pit deviate, a large level fluctuation that does not represent the actual track deviation occurs in the tracking error signal, and the tracking control is performed using this tracking error signal. There is also a problem that a track shift occurs after passing through the sector address portion.

In addition, since the same address pit is assigned to the adjacent land track and the groove track, there is also a problem that it is not possible to identify whether the track currently following is a land track or a groove track.

The present invention has been made in view of the above problems, and by devising the arrangement of the address pits in the sector address portion, it is possible to reduce the read error of the address signal due to the track shift, and to reduce the track shift after passing the sector address.
It is another object of the present invention to provide an optical disk capable of identifying tracks of lands and grooves, and an optical disk recording / reproducing apparatus using the optical disk.

DISCLOSURE OF THE INVENTION The optical disc of the present invention has an adjacent spiral first track and a spiral second track, and is an optical disc on or from which information is recorded or reproduced on the first and second tracks. A first address block formed so as to extend over both the first track and the second track adjacent on the inner peripheral side of the first track; and And an address area including a second address block formed so as to extend over both the second track adjacent to the outer periphery of the first track.

In one embodiment, a land / groove recording / reproducing optical disk including a plurality of sectors having a sector address area and a data area, wherein the sector address area has a plurality of address blocks, At least two address blocks adjacent in the circumferential direction among the plurality of address blocks are formed at positions shifted to the opposite side with respect to the track center, and each of the plurality of address blocks is And a portion indicating an ID number for identifying the plurality of address blocks in the sector address area.

In one embodiment, the at least two adjacent address blocks are formed at positions shifted from the center of the track toward the inner circumference or the outer circumference by about half the track pitch in the radial direction.

In one embodiment, the portion indicating the address number is:
In the same sector address area, the plurality of address blocks have a common data pattern.

In one embodiment, each of the plurality of address blocks has non-pit data at the beginning and end thereof.

In one embodiment, the length of the non-pit data is longer than a disk rotation accuracy in a laser cutting process for manufacturing a disk master.

In one embodiment, of the plurality of address blocks, a head address block includes a reproduced clock synchronization signal portion longer than a reproduced clock synchronization signal portion included in another address block.

In one embodiment, the sector address area has a block composed of information irrelevant to the identification of the address number, and the block extends radially inward or outward from the center of the track. At a position shifted by about half the track pitch.

In one embodiment, an interval is formed along the circumferential direction between the at least two adjacent address blocks.

In one embodiment, in the sector address area, the address blocks are arranged circumferentially so that the pits constituting the address blocks on both sides of one track coincide in phase.

An optical disk recording / reproducing apparatus according to the present invention is an optical disk recording / reproducing apparatus for a land / groove recording / reproducing optical disk having a plurality of sectors having a sector address area and a data area, wherein the sector address of the optical disk is The area has a plurality of address blocks,
At least two address blocks adjacent in the circumferential direction among the plurality of address blocks are formed at positions shifted to opposite sides with respect to the track center, and each of the plurality of address blocks is The recording / reproducing apparatus has a portion indicating an address number for identifying a plurality of sectors, and a portion indicating an ID number for identifying the plurality of address blocks in the sector address area. An optical head that irradiates a light beam onto the optical disk, receives reflected light from the optical disk and outputs a reproduction signal, and an address from which the address number and the ID number are read when the sector address of the optical disk is reproduced. A signal reproducing unit.

In one embodiment, the apparatus further includes an address correction unit that corrects the address number read for each address block according to the ID number using a signal indicating whether land reproduction is groove reproduction.

In one embodiment, a memory for storing the address number read by the address signal reproducing unit in association with the ID number read by the address signal reproducing unit; A comparator for comparing two or more address numbers respectively associated with each other, and detecting whether or not the two or more address numbers match, and irradiating a reproducing light beam based on an output of the comparator. A determination unit for determining whether the track being performed is a land track or a groove track.

It is preferable that the apparatus further comprises an address correction block for correcting the address number according to the ID number.

In one embodiment, a tracking error signal detection unit that detects a tracking error signal indicating the amount of displacement between the track and the light spot, a timing generation unit that generates a gate pulse signal synchronized with each address block in the sector address area, An outer-peripheral value sample-hold unit that samples and holds the level of the tracking error signal for an address block arranged on the outer peripheral side in synchronization with the gate pulse signal, and the level of the tracking error signal for an address block arranged on the inner peripheral side An inner circumference sample-and-hold unit that samples and holds
A differential circuit that calculates a difference between the values of the outer value sample and hold unit and the inner value sample and hold unit, a gain conversion unit that converts an output of the differential circuit into a signal having a predetermined level,
A tracking offset correction circuit for performing tracking correction using an output from the gain calculation unit.

In one embodiment, a reflected light amount signal detecting unit that detects a reflected light amount from the optical disk, a timing generating unit that generates a gate pulse signal synchronized with each address block of the sector address, An outer-peripheral value sample-and-hold unit that samples and holds the reflected light amount signal level for the address block arranged on the outer peripheral side, and an inner peripheral value sample-and-hold unit that samples and holds the reflected light amount signal level for the address block arranged on the inner peripheral side A differential circuit for calculating a difference between the value held by the outer peripheral value sample / hold unit and the value held by the inner peripheral value sample / hold unit, and converting the output of the differential circuit into a signal of a predetermined level. A gain conversion unit for conversion, and a tracking unit for performing tracking correction using an output from the gain calculation unit. Further comprising a ring offset correction circuit.

Still another optical disc according to the present invention has an adjacent spiral first track and a spiral second track, and records and reproduces information on the first and second tracks. An address block formed so as to extend over both the first track and the second track; and a track identification mark formed on one of the first and second tracks. It has.

In one embodiment, the address areas are arranged according to a CAV format or a ZCAV (ZCLV) format.

Still another optical disk according to the present invention is an optical disk having an adjacent spiral first track and a spiral second track, and recording or reproducing information on or from the first and second tracks. An address block formed so as to extend over both the first track and the second track; and the second track adjacent to the first track on the inner peripheral side of the first track. An address area having a first track identification mark extending over both of the first track identification mark and the second track identification mark extending over both the first track and the second track adjacent on the outer peripheral side of the first track. And the first track identification mark and the second track identification mark are the same.

Still another optical disc according to the present invention has an adjacent spiral first track and a spiral second track, and records or reproduces information on or from the first and second tracks. An address block formed so as to extend over both the first track and the second track; and a track provided in a control information area of one of the first track and the second track. An address area having an identification mark is provided.

The optical disk recording / reproducing apparatus is an optical disk recording / reproducing apparatus capable of reproducing information from the optical disk of the present invention, and includes a track designating means for selecting a first track or a second track on which information is to be recorded or reproduced. And a track identification mark reproducing means for reading the track identification mark. The track identification mark reproducing means reads the track identification mark being reproduced,
In accordance with the presence or absence of the track identification mark, it identifies whether the track being reproduced is the first track or the second track, and outputs a track identification signal. Switching between the first track and the second track is switched according to a track identification signal.

The optical disc recording / reproducing apparatus is capable of recording / reproducing information from / on the optical disc of the present invention.
A playback device, comprising: track designation means for selecting a first track or the second track on which information is to be recorded or reproduced; and a first track and the second track adjacent to the first track. The first, which straddles both
Address reproducing means for reading the first and second address blocks; and, based on the first and second address blocks reproduced by the address reproducing means, the track being reproduced is the first track and the second track. A track identification unit for identifying which one of the tracks the track is, and the track identification unit determines whether the track being reproduced is the first track based on a difference between the two addresses reproduced by the address reproduction unit. And the second track is identified to output a track identification signal, and the track designating means switches the selection between the first track and the second track based on the track identification signal.

The optical disc recording / reproducing apparatus is capable of recording / reproducing information from / to the optical disc of the present invention.
A playback device, comprising: track designation means for selecting the first or second track for recording or reproducing information; and both the first track and the second track adjacent to the first track. A track identification mark reproducing means for reading a straddling track identification mark; and two track identification marks reproduced by the track identification mark reproducing means, wherein the track being reproduced is any one of the first track and the second track. Track identification means for identifying whether the track being reproduced is the first track identification mark based on a difference between the two track identification marks reproduced by the track identification mark reproducing means. A track identification signal is output by identifying whether the track is the track or the second track, and the track designation means outputs the track identification signal. An optical disk recording / reproducing apparatus, wherein selection between the first track and the second track is switched based on a rack identification signal.

An optical disc recording / reproducing apparatus capable of recording / reproducing information from / to an optical disc of the present invention, comprising: a track designating means for selecting the first track or the second track for recording or reproducing information; Data reproducing means for reading a track identification mark provided on the optical disc, a track polarity determining means for determining the polarity of the reproduced track, and a track selecting signal correcting means for correcting a track selecting signal of the track specifying means. At the start of reproduction, the data reproducing means reproduces the track identification mark in the control information area, and the track polarity determining means selects a track from the track identification mark of the reproduced track and a track selection signal of the track specifying means. Discriminates whether the track is correct or not, outputs a track polarity discrimination signal, and Signal correction means said corrects the track selection signal of the track designation means based on the track polarity determination signal, for selecting the first track and the second track.

In one embodiment, the method of identifying a track on an optical disc reads a plurality of address blocks provided in one address area and detects a match or mismatch of at least two address blocks to reproduce the track. Identify whether the track is the first track or the second track.

According to the present invention, by providing a sector address in which an address block wobbled in the radial direction with respect to the center of each track is provided with respect to the center of each track, it is possible to reduce defective reading of an address signal due to track deviation,
Track deviation after passing the sector address can be reduced.

Further, it is possible to identify whether the currently reproduced track is a land or a groove.

Further, it is possible to detect an off-track signal indicating the actual track shift amount between the light spot and the track from the difference between the reflected light amount signal or the tracking error signal obtained in the address block wobbled on the inner track and the outer track. Correcting the tracking error signal using this off-track signal enables accurate track following.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram of a first embodiment of an optical disk according to the present invention.

FIG. 2 is a layout diagram of address blocks in the first embodiment of the optical disc according to the present invention.

FIG. 3 is a block diagram of an embodiment of an optical disk recording / reproducing apparatus according to the present invention.

FIG. 4 is a configuration diagram of a track identification circuit used in the optical disk recording / reproducing apparatus according to the present invention.

FIG. 5 is a schematic diagram of a second embodiment of the optical disk according to the present invention.

FIG. 6 is a diagram for explaining the format of the sector address in the second embodiment of the optical disk according to the present invention.

 FIG. 7A is a diagram showing a configuration of a sector address area.

FIG. 7B is a diagram for explaining an RF signal and a TF signal in a sector address area.

FIG. 8A and FIG. 8B are diagrams for explaining a track shift of an optical spot and an RF signal.

9A and 9B are layout diagrams of address blocks in another embodiment of the optical disc according to the present invention.

FIGS. 10A and 10B are layout diagrams of address blocks in another embodiment of the optical disc according to the present invention.

FIG. 11 is an arrangement diagram of address blocks in still another embodiment of the optical disc according to the present invention.

FIG. 12 is an arrangement diagram of address blocks in still another embodiment of the optical disc according to the present invention.

FIG. 13 is a block diagram of an embodiment of an optical disk recording / reproducing apparatus according to the present invention.

FIG. 14 is an arrangement diagram of address blocks in still another embodiment of the optical disc according to the present invention.

 FIG. 15 is a diagram illustrating the operation of the address correction unit.

FIG. 16 is a block diagram of another embodiment of the optical disk recording / reproducing apparatus according to the present invention.

FIG. 17A is a block diagram of a land group identification unit.

FIG. 17B is a block diagram of another land group identification unit.

FIG. 18 is a block diagram of another embodiment of the optical disk recording / reproducing apparatus according to the present invention.

FIG. 19 is a diagram illustrating a change in the TE signal with respect to off-track.

FIG. 20 is a timing chart of the timing generator.

FIG. 21 is a block diagram of another embodiment of the optical disk recording / reproducing apparatus according to the present invention.

FIG. 22 is a diagram illustrating a change in the AS signal with respect to off-track.

FIG. 23 is an arrangement diagram of address blocks in still another embodiment of the optical disc according to the present invention.

FIG. 24A is a diagram showing two address blocks to be formed.

FIG. 24B is a diagram showing two address blocks actually formed.

FIG. 25A is a diagram showing a case where one pit data overlaps another address block in two adjacent address blocks.

FIG. 25B is a diagram illustrating a case where one pit data does not overlap with the other address block in two adjacent address blocks.

FIG. 26A is a layout diagram of address blocks in still another embodiment of the optical disc according to the present invention, and FIG.
FIG. 3 is a data arrangement diagram in the address block.

FIG. 27 is a layout diagram of address blocks in still another embodiment of the optical disc according to the present invention.

FIG. 28 is a block diagram of still another embodiment of the optical disk recording / reproducing apparatus according to the present invention.

FIG. 29 is a configuration diagram of a track identification mark reproduction circuit.

FIG. 30 is an arrangement diagram of address blocks in still another embodiment of the optical disc according to the present invention.

FIG. 31 is a block diagram of still another embodiment of the optical disk recording / reproducing apparatus according to the present invention.

FIG. 32 is a configuration diagram of a track identification mark reproducing circuit used in the optical disk recording / reproducing apparatus of the present invention.

FIG. 33 is a configuration diagram of a track identification circuit used in the optical disc recording / reproducing apparatus of the present invention.

FIG. 34 is an arrangement diagram of address blocks in still another embodiment of the optical disc according to the present invention.

FIG. 35 is a block diagram of still another embodiment of the optical disk recording / reproducing apparatus according to the present invention.

FIG. 36 is a configuration diagram of a track polarity determination circuit used in the optical disk recording / reproducing apparatus of the present invention.

FIG. 37 is a configuration diagram of a track selection signal correction circuit used in the optical disc recording / reproducing apparatus of the present invention.

 FIG. 38 is a track configuration diagram of a conventional optical disc.

FIG. 39 is a schematic diagram of a sector address in a conventional optical disc.

FIG. 40 is a block diagram of a conventional optical disk recording / reproducing apparatus.

FIG. 41 is a diagram for explaining an RF signal and a TE signal in a conventional example.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings.

Embodiment 1 FIG. 1 is an external view of an optical disc 401 according to a first embodiment of the present invention. The optical disc 401 has a convex track 402 (land track) and a concave track 4
Two spiral tracks 404 of 03 (groove track) are provided.

Recording and / or reproduction of information is performed on both tracks 402 and 403, and one track is divided into one or more address areas 405 and one or more data areas 406. When one track is divided into a plurality of sectors, an address area 405 and a data area 406 are assigned to each sector. In this case, each address area 405 is also called a sector address area.

The optical disc 401 includes a substrate and various films (not shown) formed on the substrate. These films include a known recording film for recording information, a reflective film, a protective film, and the like. Further, the optical disk 401 may be an optical disk of a type in which two substrates each having an information recording surface are bonded. This is also applicable to the optical disks of the following embodiments.

Next, reference is made to FIG. FIG. 2 shows the address area 405 of the optical disc 401 in more detail. As shown in FIG. 2, tracks 403a, 402a, 403b and 40
An address area 405 indicating the address of each track (or sector) is assigned to each of 2b.

In order to indicate the address of the groove track 403a, the address area 405 is provided with a pair of address blocks 411a and 801a composed of the same pit string. In order to indicate the address of the groove track 403b, a pair of address blocks 411b composed of the same pit row and
801b is provided, and a pair of address blocks 411c and 801c composed of the same pit row are provided to indicate the address of the groove track 403c. Note that the content of information indicated by the pit pattern (pit row) of the address block differs for each track (or sector).

As is clear from FIG. 2, for example, the pair of address blocks 411b and 801b are respectively arranged at positions shifted to opposite sides with respect to the track center 408 of the groove track 403b. The amount of shift is the track pitch Tp
About half. In the case of the present embodiment, the track pitch Tp
Is set in the range of about 0.3 to 1.6 μm.

More specifically, the address block 411b is formed so as to extend over both the groove track 403b and the land track 402b around a boundary 409 between the groove track 403b and the land track 402b adjacent on the outer peripheral side of the groove track 403b. I have. Also, the address block 801b
Are formed so as to straddle both the groove track 403b and the land track 402a with the boundary line 407 between the groove track 403b and the land track 402b adjacent on the inner side of the groove track 403b as the center. That is, the two address blocks 411b and 801b are formed so as to be shifted from the center 408 of the groove track 403b by about 1/2 Tp in the outer and inner circumferential directions, respectively. Here, the groove track, the land track, and the address blocks 411b and 801b have the same width. Further, for example, two address blocks 411b and 801b formed in one address area 405 on the groove 403b include the same address configuration. Also, the two address blocks are provided at consecutive positions along the track direction (circumferential direction of the optical disc) so as to be reproduced temporally continuously. Similarly, two address blocks are formed in all other address areas not shown.

By employing the above configuration, for example, the laser beam spot moving along the track center 408 of the track 403b in the left part of FIG. 2 passes over both the address blocks 411b and 801b in the address area 405. After that, the track center 408 of the right track 403b in FIG.
It will move along the top.

The address area 405 of the optical disk shown in FIG. 2 is formed according to the CAV or ZCAV (ZCLV) format. Therefore, the address area 405 of the adjacent track is
Align in the radial direction of the disc. As a result, the land truck
Two address blocks 411b corresponding to the adjacent groove tracks 403b and 403c are provided in an address area 405 on 402b.
And 801c are formed. Here, the data area 406 is identified by first address blocks 411a and 411b having data to be reproduced first in the address area.

As a result, when the data of the groove track 403b is reproduced, the information of the two address blocks (411b and 801b) having the same value is reproduced in the address area 405, and when the data of the land track 402b is reproduced. , Two different address blocks (411b and 8
The information of 01c) is reproduced. These tracks share the same address block 411b, but the address block 801b is reproduced following the address block 411b.
Alternatively, it is possible to identify whether the track being reproduced is a groove track or a land track depending on whether the content of 801c matches the content of the address block 411b.

In FIG. 2, the first address block is located on the boundary line 409 between the groove track 403b and the land track 402b adjacent on the outer peripheral side of the groove track 403b, and the second address block is located on the groove track 403b and the groove track 403b.
Boundary line 40 of land track 402a adjacent on the inner peripheral side of 403b
Although the first address block is on the boundary line 407 between the groove track 403b and the land track 402a adjacent on the inner peripheral side of the groove track 403b, the second address block is Similar effects can be obtained for a disk provided on the boundary 409 between the land track 402b adjacent to the track 403b and the groove track 403b on the outer peripheral side.

Also, the case where the two address blocks provided for identifying the data area on the groove track have the same address information has been described, but the two address blocks provided for identifying the data area on the land track have been described. Have the same address information, the same effect can be obtained.

FIG. 3 is a configuration diagram of an optical disk recording / reproducing apparatus according to the present invention. In the specification of the present application, the invention will be described mainly with respect to reproduction of information recorded on an optical disk. However, it is needless to say that the present invention is applicable to recording of information on an optical disk. For simplicity, in the present description,
The "optical disk recording / reproducing apparatus" includes not only a recording / reproducing apparatus having a recording function but also a reproduction-only apparatus and a recording-only apparatus. That is, the “optical disc recording / reproducing device” is used as including “optical disc recording / reproducing device” in a narrow sense and both “optical disc recording device” and “optical disc reproducing device”.

The optical disk recording / reproducing apparatus of this embodiment is suitable for recording or reproducing information on or from the optical disk 401 shown in FIG. In the following description, the track specifying means is described as the CPU 601, the address reproducing means as the address reproducing circuit 603, and the track identifying means as the track identifying circuit 901.

In FIG. 3, an optical disk 401 is attached to a motor 611 and rotated. The optical head 610 focuses a laser beam on the information recording surface of the optical disc 401. The head amplifier circuit 606 converts the intensity of light reflected by the information recording surface of the optical disc 401 into a voltage and amplifies the voltage to a predetermined level signal. Binarization circuit 605 converts the reproduced analog signal into a digital signal. The linear motor 609 is for moving the optical head 610 to the target track at high speed, and the operation of the linear motor control circuit is controlled by 607. The data reproduction circuit 612 demodulates the signal digitized by the binarization circuit 605 while synchronizing with the clock, and transfers the obtained data. The ID reproduction circuit 602 includes a binarization circuit 6
An address reproduction circuit 603 for reproducing an address (address information) from the signal digitized by 05, a track identification circuit 901 for identifying the groove track 403 from the land track 402 and a land track 402 from the groove track 403, and addressless reproduction A register 902 is provided to combine the first address reproduced by the circuit 603 and the track identification signal b obtained from the track identification circuit 901 into one address a. The focus tracking control circuit 608 performs focus control for maintaining the focus of the laser light on the information recording surface and tracking control for maintaining the focus of the laser light at the center of the track on the disk. In order to access the target track, the CPU 601 moves the optical head 610 to the vicinity of the target track by using the linear motor control circuit 607, and further moves to the target track by track jump using the tracking control circuit 608 to perform tracking. A land track or a groove track is selected by designating the polarity.

FIG. 4 is a configuration diagram of a track identification circuit 901 that generates a track identification signal b from two addresses e reproduced from the optical disk 401 in FIG. 1001 is a register holding a first address, 1002 is a register holding a second address, 1003 is a comparator for comparing two addresses, 1004
Is a flip-flop holding the comparison result.

Hereinafter, an address reproducing operation by the optical disk recording / reproducing apparatus of FIG. 3 will be described with reference to FIGS.

When a logical address of a track on which data is to be recorded or reproduced is given, a CPU 601 controls a linear motor control circuit.
Issue a seek command to 607, drive linear motor 609,
The optical head 610 is moved near the target track. Next, the CPU
The optical head 601 outputs a track jump command or a track selection command according to whether the track is a land track or a groove track to the focus track control circuit 608, so that the optical head 610 reaches the target track. In the focus tracking control circuit 608, when a track selection command is given, the polarity of tracking control is switched to cause the optical head 610 to jump half a track, and focus and track a target track.

The reflected light from the optical disk 401 is converted into a current by the plurality of photodetectors of the optical head 610, and is converted into a voltage by the head amplifier 606 as a reproduction signal for each photodetector. Various operations are performed on the reproduction signal depending on the purpose of use, and a reproduction signal, a tracking error signal, and a focus error signal representing information are generated. The tracking error signal and the focus error signal are provided to a focus tracking control circuit 608 and used for focus tracking of the optical head 610. The reproduction signal representing the information is digitized by the binarization circuit 605.

In this optical disk recording / reproducing apparatus, a logical address for identifying a data area is an address block 411 (reproduced by an address reproducing circuit 603) common to the land track 402 and the groove track 403, and a logical address for identifying the land track 402 and the groove track 403. Track identification signal b
(1 bit), the most significant 1 bit is a value obtained by the track identification signal b, and the remaining addresses are addresses obtained from the address area.

The track identification circuit 901 includes two registers 1001 and 1002, a comparator 1003, a flip-flop 1004, delay elements 1005 and 10
06, 1007. The track identification circuit 901 is
Two addresses e are fetched into registers 1001 and 1002 with a gate pulse signal obtained by delaying the address detection signal d by a predetermined time, and the two addresses e are compared by a comparator 1003. That is, the address detection signal d has three delay elements 1005, 1005
The signal is converted into a gate pulse signal for the registers 1001 and 1002 and the flip-flop 1004 by being delayed for a predetermined time by 6 and 1007. This circuit generates a track identification signal b indicating a groove track when the two address blocks 411 and 801 match, and generates an identification signal b indicating a land track when the two addresses are different. .

A register 902 in FIG. 3 holds the first address reproduced by the address reproducing circuit 603. The address a for identifying the data area is obtained by setting the most significant bit of the address of the data obtained by the first address and the track identification signal b as one address.

The data reproducing circuit 612 compares the address a reproduced by the ID reproducing circuit 602 with the address given from the CPU 601, and
If they match, the data is reproduced after a fixed time from the address reproduction.

Finally, when it is determined that the address given from the CPU 601 is different from the reproduced address a, the track search is performed again. However, when only the most significant bits of these addresses are different, a half track jump is performed to invert the track selection signal for selecting the tracking polarity. That is, in the above example, the case where only the highest order of the addresses is different means that although the land track and the groove track have the same address,
This is the case where the selection of the land track or the groove track is incorrect. In order to correct this state, the tracking polarity is switched by inverting the track selection signal.

When the data of the groove track of the optical disk 401 shown in FIG. 2 is reproduced by the above-described apparatus, the laser beam scans substantially the center 408 of the groove track, and two address blocks (with the same value) in one address area. For example, the information of 411b and 801b) is reproduced. When reproducing the data of the land track, the laser beam scans substantially the center 410 of the land track, and two different address blocks (for example, 411b and 80b) within one address area.
Play 1c). As described above, since the combination of the two addresses reproduced from the address area differs depending on whether the currently reproduced track is a land track or a groove track, the currently reproduced track is the land track 402 only from the reproduction signal. And the groove track 403 can be identified. Therefore, regardless of the correspondence between the groove shape (groove track or land track) and the tracking polarity, recording / reproduction on a desired track can be performed using only the reproduction signal.

According to the optical disk recording / reproducing apparatus described above, the tracking polarity can be automatically switched from only the reproduction signal based on the difference between the two addresses. Tracking is possible. Therefore, the compatibility of the optical disc recorded on both the land track and the groove track can be improved.

Embodiment 2 FIG. 5 shows a second embodiment of the optical disc according to the present invention.

According to a predetermined physical format, a plurality of sectors 4 are continuously arranged along the track 2 on the disk 1. Each sector 4 comprises a sector address area 5 for indicating the position of the sector on the disk, and a data area 6 for actually recording data.

FIG. 6 shows a logical format of a sector address adopted by the optical disc 1 of the present embodiment. In the optical disc 1 of this embodiment, four address blocks 16 to 19 are provided in one sector address. In FIG. 6, address blocks 16 to 19 are ID1 to I, respectively.
It is described as D4. Each address block is VFO11, A
M (address mark) 12, sector address number 13, duplication order number (ID number) 14, CRC (Cyclic Redundancy Chec)
k) contains 15;

The VFO 11 is a reproduction clock synchronizing signal section having a continuous repetitive data pattern for reliably reproducing an address signal from an address area even when the rotation speed of the disk fluctuates. The recording / reproducing apparatus locks a PLL (Phase Locked Loop) with the repetitive data pattern, and generates a data read clock. AM12
Is composed of a special code pattern for indicating the start position of the address data. The address number 13 is a data pattern indicating the position of the sector on the disk. The ID number 14 indicates the position of each address block in the address area, and may be expressed as a “repetition number”. CRC is an error detection code generated from an address number and an ID number. In addition,
The error detection code only needs to be able to detect a reading error of the address number and the ID number, and may be a code using a Reed-Solomon code as a code other than the CRC. Each address block may include additional information other than the information shown in FIG.

FIG. 7A shows an arrangement diagram of address blocks in a sector address area of the optical disc of the present embodiment. In the above-described embodiment, two address blocks are provided in each address area. In this embodiment, four address blocks are provided in each address area. However, the number of address blocks provided in each address area is 4
It is not limited to one.

FIG. 7A shows a land track 22 and groove tracks 21 and 23 adjacent thereto. In the sector address area 5 provided between the data areas 6 and 7, four address blocks ID1 to ID4 are arranged so as to alternately wobble with respect to the track center. More specifically, if the track width (or track pitch) of one track is Tp for both the land track and the groove track, the address blocks ID1 to ID4
Are shifted in the radial direction by Tp / 2 from the track center, and are alternately arranged on the inner peripheral side and the outer peripheral side. Note that address pits 25 are formed in each of the address blocks ID1 to ID4, and recording marks 26 are formed in the data areas 6 and 7. The width of the address pits 25 (size in the disk radial direction) is 0.1 to 0.6 μm in this embodiment. The recording mark 26 of the present embodiment is formed on a recording film.

Normally, the address pits 25 are
Formed when forming 23. When the groove track and the address pit are formed by the laser cutting method, the laser beam spot for cutting moves to the right in FIG. 7A while forming the groove track 21 of the data area 6. Thereafter, the laser light spot moves rightward in 7A while forming address blocks 16, 17, 18 and 19 in this order in the sector address area 5. Specifically, in the data area 6, laser light is continuously emitted so as to form a groove track of a predetermined width, and in the sector address area 5, the laser light is emitted 1 / radially from the groove track.
In a state shifted by 2 Tp, laser light is emitted intermittently according to the address spit to be formed. In addition,
In FIG.7A, the address blocks ID1 and ID3 are provided at positions shifted upward in FIG.7A from the address blocks ID2 and ID4.On the contrary, the address blocks ID1 and ID3 are replaced with the address blocks ID2 and ID3. It may be provided at a position shifted downward in the figure from ID4.

FIG. 7B shows waveforms of a reproduction signal (RF signal) and a tracking error signal (TE signal) when the light spot 24 reproduces the sector address area 5. In general, the amplitude of the RF signal is a value substantially proportional to the area of the light spot 24 over the address spit 25, so that when the light spot 24 is at the center of the track, the address blocks ID1 and ID3 and the address blocks ID2 and ID4 Although the direction in which the light spot 24 irradiates the address spits 25 is different, the irradiating area is almost the same, so that the RF signal is obtained with substantially the same amplitude, as shown in the figure.

The TE signal has a value proportional to the amount of displacement between the light spot 24 and the track groove in the data areas 6 and 7 formed of grooves, but the TE signal also has a similar value in the sector address area 5 formed of pits. A value proportional to the amount of misalignment between the spot 24 and the address pit 25 (the output of the TE signal for the same amount of misalignment differs between the groove and the pit) is obtained. Therefore, as shown in FIG. 7B, TE signals having different polarities depending on the arrangement positions of the address blocks are obtained.

FIG. 8A and FIG. 8B are diagrams showing a state of an RF signal in a sector address area in a state where a light spot is off track. FIG. 8A shows an RF signal in the sector address area 5 when the light spot 24 is shifted to the inner track side, and FIG. 8B shows an RF signal when the light spot 24 is shifted to the outer track side. . 8A, since the light spot 24 passes near the address blocks 16 and 18 in the ID1 and ID3 portions, the RF signal amplitude increases, and the light spot 24 passes away from the address blocks 17 and 19 in the ID2 and ID4 portions. Therefore, the RF signal becomes small. Therefore, it becomes difficult to read the address signal with ID2 and ID4. However, it is sufficient to read at least one address block per sector address normally. In the example of FIG. 8A, ID1 and ID3 have large RF signal amplitudes and the addresses are easy to read, so that they can be read as sector addresses.

On the other hand, in the case of FIG. 8B, similarly, in ID1 and ID3, the RF signal amplitude becomes small and the address reading becomes poor.
In D4, the RF signal amplitude increases in reverse, and the address reading becomes better. That is, regardless of whether the light spot is shifted from the center of the track to the inner side or the outer side, the address reading ability in the sector address portion does not decrease.

It goes without saying that the address reading ability is the same for both the land track and the groove track.

Further, as shown in FIG. 7B, the level of the TE signal alternately shifts positively and negatively for each address block. However, when the address block is wobbled, the frequency of the level fluctuation becomes high. Considering the transit time (100 μsec or less) of the normal sector address area, the frequency of the level fluctuation of the TE signal is 20 kHz or more and the light spot is It is much higher than the control bandwidth that follows the track. So this
The light spot does not react to the level shift of the TE signal. In addition, since the average value of the level fluctuation is almost 0, the shift of the light spot due to the DC component hardly occurs. Therefore, the influence of the sector address area on the tracking control unit is small, and disturbance of the tracking control immediately after passing through the sector address area can be reduced.

In this embodiment, 4 addresses per sector address are used.
The case of one address block has been described. However, if two or more address blocks are provided, a similar effect can be obtained in improving the address reading capability with respect to track deviation.

Further, when the even-numbered address blocks are evenly arranged on the inner and outer circumferences, an effect of preventing disturbance of tracking control after passing through the address area can be obtained. In the arrangement of the odd number of address blocks, a DC component occurs due to the level shift of the TE signal. However, since the frequency is higher than the tracking control band as described above, there is almost no effect. It is desirable to arrange the even number of address blocks evenly on the inner and outer peripheries in view of the stability of address reading and tracking control.

Embodiment 8 Next, a third embodiment of the optical disc according to the present invention will be described.

9A and 9B show the arrangement of information blocks in the sector address area in the present embodiment. In the optical disc of the present embodiment, the additional information blocks 107 and 1 including additional information that is not address number information in the sector address area 5.
08 and 109 are provided. Others have the same configuration as the configuration shown in FIG. 7A. Here, # 100 and # 101 indicate track address numbers.

Each of the address blocks 16 to 19 includes address information for identifying an address number and an ID number. As in the case of the address blocks 16 to 19, it is preferable to displace them from the track center in the radial direction by a width of approximately Tp / 2. If the additional information block is shorter in length than the address block, or if it is impossible to divide the additional information into two, as shown in FIG.
Alternatively, the additional information block 107 is provided on one of the outer peripheral sides.
Deploy. On the other hand, if the additional information block is relatively long, the additional information is divided into identifiable block units 108 and 109 as shown in FIG. It is sufficient to dispose them.

By adopting the above configuration, even when additional information is added to the sector address area, similar to the above-described embodiment, the read performance of the address information and the additional information with respect to the track shift can be improved, The stability of tracking control immediately after passing through the address area can be improved.

In this example, the additional information is arranged at the last part (right side in the figure) of the sector address area, but may be arranged at another position.

Fourth Embodiment Next, a fourth embodiment of the optical disc according to the present invention will be described.

FIGS. 10A and 10B show the arrangement of address blocks in the address area in the present embodiment. 10A and 10B, 110 and 112 are groove tracks, 111 is a land track, 113, 114, 115, 116, 117, 118, 119 and 120 are address blocks, and 24 is a light spot.

First, a method of forming tracks and address pits will be described. Tracks and pits are formed by irradiating the rotating laser beam with the cutting laser beam. When the laser beam is continuously irradiated, a single continuous groove becomes a track (a groove track in this embodiment), and the laser beam is intermittently turned ON / OFF for a specified time to irradiate the pit. Is formed. That is, in a disk having a sector address, the laser beam for cutting is controlled over the entire circumference of the disk by controlling the irradiation of the laser beam at the grooves and address pits while moving the cutting laser light in the radial direction by the track pitch with one rotation of the master disk. An address pit is formed. Tracks and address pits are formed in the same manner in the wobbled address pitch according to the present invention. However, since the address pits are divided and arranged on the inner and outer peripheries of the track, the center of the cutting laser beam is arranged radially in each address block. Turn on / off the cutting laser light by shifting by Tp / 2. Alternatively, three laser light beams of a track groove forming laser light, an inner peripheral side address pit forming laser light, and an outer peripheral side address pit forming laser light are set, and each laser light is turned ON / OFF at a predetermined position. Also, track grooves and address pits can be formed.

10A and 10B, first, the groove track 110
(Left side in the figure) and address blocks 113, 114, 115, 116
Are formed in this order. Thereafter, after one revolution of the master disc, the groove track 112 and the address blocks 117, 118, 119, and 120 are formed in this order. At this time, since the rotation accuracy and the like of the master disc fluctuate, the circumferential positions of the address blocks (for example, the address blocks 113 and 117) including the same ID number do not always match. As shown in FIG. 10A, if the data is shifted by ΔX, the end of the address block 117 and the head of the address block 114 are set to Δ at the time of reproducing the data of the land track 111.
Since only X overlaps, the reproduction signal (RF) signal may not be accurately detected. Therefore, as shown in FIG. 10B, by arranging the circumferential position of each address block with a problem Xm that is higher than the disk rotation accuracy at the time of cutting, overlapping of adjacent address blocks can be prevented, and reproduction of address signals can be prevented. Becomes more certain.

The spacing Xm that is greater than the disc rotation accuracy during cutting is
For example, it is set to a value within the range of 0 to 1.4 μm. This interval Xm may be changed according to the distance from the center of the disk.

Embodiment 5 Next, a fifth embodiment of the optical disk according to the present invention will be described.

FIG. 11 shows an arrangement diagram of address pits in a sector address area on the optical disc of this embodiment. 11, 150 and 152 are groove tracks, 151 is a land track, 153, 154, 155, and 156 are address blocks and 157 to 1
Numeral 64 is an address pit constituting an address block. At the time of cutting, grooves and address pits are formed continuously. In the groove track 150, the pits of the address blocks 153 and 154 are formed in synchronization with a cutting reference clock.
Address block 1 when reproducing data from 0
The interval between the address pits 53 and 154 on the time axis is the information read clock cycle Tw (for example, about 5 to 100 nanoseconds).
Becomes an integral multiple of. That is, in addition to the pit interval T10 in the same address block, in principle, the pit interval T11 between different address blocks is also an integral multiple of Tw.

However, in reality, as described in Example 4,
In order to prevent overlapping of address blocks due to rotation fluctuation during cutting, the position of the address block for the next groove track 152 is shifted in the circumferential direction. Also in this case, when the land track 151 is reproduced with ΔX set to a free length, the time interval T from the pit 163 of the address block 155 to the pit 160 of the address block 154 is obtained.
14 may not be an integral multiple of Tw because it is not synchronized with the reference clock at the time of cutting.

If the time interval T14 does not become an integral multiple of Tw, it takes time to adjust the phase of the clock for reading data in the PLL again with the VFO at the head of the address block 154.

In order to solve such a problem, the address pits may be arranged in phase so that the time interval T12 of the shift ΔX is substantially an integral multiple of Tw. Then, roughly T1
4 is also an integral multiple of Tw, and the time required for PLL synchronization in the address block 154 during data reproduction of the land track 151 can be reduced.

Embodiment 6 Next, a sixth embodiment of the optical disc according to the present invention will be described.

FIG. 12 shows the arrangement of address blocks in the sector address area on the optical disc of this embodiment. 12, 130 and 132 are groove tracks, 131 is a land track, 133, 134, 135, 136, 137, 138, 139 and 140 are address blocks, and 24 is a light spot. 141 is VFO, 142 is A
M, 143 is the address number, 144 is the ID number, 145 is the CRC, 146,
147 is a dummy data area.

In this embodiment, as shown in FIG. 12, dummy data areas 146 and 147 including data irrelevant to address signal identification are arranged at the beginning and end of each address block. Where VFO141, AM142, address number 143, ID number
144 and CRC 145 are as described in the second embodiment. The provision of the dummy data areas 146 and 147 prevents the head of the address or block from overlapping the end of the previous address block even when the circumferential position of the address block fluctuates.

The pit pattern of the dummy data is arbitrary. For example, if the pit pattern arrangement is the same as the pit pattern of the VFO 141 at the head of the address information area, the VFO area becomes apparently longer, and there is an advantage that the generation of a clock for reading data increases more reliably. The lengths of the dummy data areas 146 and 147 need only be such that the dummy data areas do not overlap the range that is actually necessary for identifying the address signal.

The dummy data area may be arranged only at the end of each address block.

Embodiment 7 Next, an embodiment of an optical disk recording / reproducing apparatus according to the present invention will be described.

FIG. 13 is a block diagram of an optical disc recording / reproducing apparatus capable of reading a sector address of the optical disc shown in FIG. 7A. In FIG. 13, 31 is a disk, 32 is a disk motor, 33 is an optical head, 34 is an address reproducing unit, an adding circuit 35, a waveform equalizing unit 36, a data slice unit 37, a PLL 38, a demodulator 39, an AM detecting unit 40, and a switch. And a CRC discriminating unit 42. 43 is an error correction unit, and 44 is an address correction unit.

FIG. 14 shows the recording / reproduction of information by the optical disk recording / reproducing apparatus.
3 shows a configuration of a sector address of an optical disc on which reproduction is performed. This optical disc has the same configuration as the optical disc of FIG. 7A. In FIG. 14, a land track 52,
The adjacent groove tracks 51 and 53 are shown. In the sector address area 5 provided between the data areas 6 and 7, four address blocks 54 to 57 are arranged so as to alternately wobble with respect to the track center. In this example, it is assumed that the track number is counted up by one in one round of the track, and the groove track 51 is counted.
Is the address # 100, the land track 52 is the address # 101, and the groove track 53 is the address # 101. The numerical value (# 100 or the like) in each address block represents the value (address) set to the address number 13 in that address block.

The operation of reading signals from the sector address area 5 in FIG. 14 will be described using the optical disk recording / reproducing apparatus in FIG.

First, the optical head 33 irradiates the optical disk 31 with laser light, and detects the intensity of light reflected by the optical disk 31. A reproduction signal (RF signal) is generated from the amount of reflected light. Waveform equalizer 36, data slicer 37, PLL 38, demodulator 39, AM
The operation of extracting the address number and ID number from the RF signal for each address block through the detection unit 40, the switch 41, and the CRC determination unit 42 is the same as the operation described in the conventional example.

When the light spot 24 reproduces the data of the groove track 51, the address signal obtained in the sector address area is a set of (address number, ID number) in order (# 10
0, 1), (# 100, 2), (# 100, 3), (# 100,
4), and this value is input to the address correction unit 44.
The address correction unit 44 detects an address based on the input address number and ID number.

FIG. 15 shows a set of signals input to the address correction unit 44 at the time of reproducing data of a groove track and data of reproducing a land track. The address blocks 54, 55, 56 and 57 containing the same address number are wobbled on the inner and outer peripheries with respect to the center of the groove track 51, so that they can be obtained when reproducing the data on the groove track 51. The address numbers of ID1 to ID4 all have the same value (# 100 in this case). Therefore, the address correction unit 44 may output the read address number (# 100) as it is as the final address value.

On the other hand, when the light spot 24 reproduces the data of the land track 52, the address signals obtained in the sector address area are (# 101, 1), (# 100, 2), (# 101,
3), (# 100, 4) are input to the address correction unit 44 in this order. Since it is known from the arrangement pattern of the address blocks shown in FIG. 14 that the address numbers indicated by ID1 and ID3 are smaller by 1 than the actual address numbers, the address correction unit 44 reads out the address numbers from ID2 and ID4. The address number # 101 is obtained by adding 1 to the address number # 100. ID1 and ID3
Since the address number # 101 read out in step 1 matches the actual address value, the address number is used as it is. Then, the final address value # 101 is output. A signal (L / G signal) indicating whether the groove is being reproduced or the land is being reproduced is provided by the address correction unit 44.
, The address correction can be achieved.

As described above, in the optical disc recording / reproducing apparatus of the present embodiment, if it is known in advance whether the groove is to be reproduced or the land is to be reproduced, the read address number (for example, # 100)
Is corrected based on the ID number (for example, 2) read almost simultaneously, and the correct sector address value (for example, # 10
An address correction unit 44 capable of obtaining 1) is provided. As a result, it is possible to manage the sector address of the optical disc having the arrangement as shown in FIGS. 7A, 7B and 14.

In this example, the address numbers of the land track and the groove track are the address numbers indicated by ID1.
When reading each sector address, almost all of the four addresses ID1 to ID4 are normally read normally.
Therefore, when the value of ID1 is normally obtained, it is preferable to use the value as it is as the track address.
That is, the track address of the land track 52 is set to # 100.
However, setting to # 101 is more practical because there is no need to correct the address number read from ID1. Also,
If the ID1 VFO is provided slightly longer than the other address blocks and the read accuracy of ID1 is increased by this, the advantage that the read accuracy of the read land and groove is equal if ID1 shows the track address number as it is There is also.

In the above embodiment, the case where one track has one sector has been described. However, in the case where the number of sectors included in one track is N and the disk has a format in which the sector address numbers increase in order, the address address adjacent to the address address # 100 is (# 100 + N).
For this reason, the address correction unit can obtain the address value in the land track and the groove track in the same manner as described above by obtaining the correction value by adding N to the read address value during the reproduction of the land track.

Further, even when the number of sectors included in one track is N and the numerical value of the address number changes discontinuously, the format of the sector address is determined from the address number and the sector number read for each address block. What is necessary is just to calculate a correction value.

Furthermore, although the case where the same address number can be read when reproducing data on a groove track has been described here, the same applies when an optical disc is configured such that the same address number can be read when reproducing data on a land track.

Although the same address number is arranged on the inner and outer circumferences of one track, it is not always necessary to arrange it on one track.
If the number and the arrangement pattern of the address blocks are known, it is possible to correct the read address number based on the ID number.

Embodiment 8 Next, another embodiment of the optical disk recording / reproducing apparatus according to the present invention will be described.

FIG. 16 is a block diagram of the optical disc recording / reproducing apparatus of the present embodiment. In FIG. 16, 31 is a disk, 32 is a disk motor, 33 is an optical head, 34 is an address reproducing unit, an adding circuit 35, a waveform equivalent unit 36, a data slice unit 37, a PLL3.
8, the demodulator 39, the AM detector 40, the switch 41, and the CRC determiner 42. 43 is an error correction unit, and 61 is a land / groove identification unit.

FIG. 17A is a block diagram showing the configuration of the land / groove discriminating unit 61. 62 is a memory 1, 63 is a memory 2, 64 is a memory 3, 65 is a memory 4, 66 is a comparator 1, 67 is a comparator 2, 68 is a comparator 3, 69 is a comparator 4, and 70 is a judgment unit.

Using the optical disk recording / reproducing device as described above,
An operation of identifying a land / groove from an address signal in a sector address area where an address block is arranged as shown in FIG. 10 will be described. First, the optical head 33 irradiates the disk 31 with laser and detects a reproduction signal (RF signal) from the amount of reflected light. From the RF signal, the waveform equalizer 36, data slicer 37,
PLL 38, demodulator 39, AM detector 40, switch 41, CRC discriminator 42
The operation of extracting an address number and an ID number for each address block through is similar to the operation described in the conventional example.

Address signals read by the light spot 24 by scanning the sector address area 5 are sequentially input to the land / groove identification unit 61 as a set of (address number, ID number). In the land / groove identification unit 61,
The read address numbers are stored in the memories 62, 63, 64, 65 corresponding to the input ID numbers as they are. That is, the address number of the ID number 1 is stored in the memory 1 (62), and the address number of the ID number 2 is stored in the memory 2 (63).

Referring to FIG. 14, when the data of the groove track 51 is reproduced, # 100 is stored in the memory 1, # 100 is stored in the memory 2, # 100 is stored in the memory 3, and # 100 is stored in the memory 4. Is done. In the comparator 1 (66) of FIG. 17A, the memory 1 (6
By comparing 2) with the two address numbers in the memory 2 (63), it is determined whether the address numbers match or not, and the result is passed to the determination unit 70. Similarly, comparator 2 (67) compares memory 2 (63) with memory 3 (64), and comparator 3 (68) compares memory 3 (64) with memory 4 (6).
5) and comparator 4 (69) stores memory 4 (6
5) is compared with the memory 1 (62) and passed to the judgment unit 70.

In this example, from the address block arrangement pattern shown in FIG. 14, in the groove, the results of the comparators 1 to 4 should all be "matches". When all the outputs of the comparators match, the determination unit 70 determines that the track currently being reproduced is a groove track. On the other hand, when the light spot 24 is reproducing the land track 52 of FIG. 14, the memory 1 (62) has # 101 and the memory 2 (6
3) # 100, memory 3 (64) # 101, memory 4 (6
5) stores # 100. As a result, the outputs of the comparators 1 to 4 all become "mismatch". As described above, in the land track, the results of the comparators 1 to 4 must be all “mismatched” from the arrangement pattern of the address blocks as shown in FIG. In this case, it is determined that the track currently being reproduced is a land track.

As described above, it is possible to determine whether the track currently being reproduced is a land track or a groove track by checking whether the address numbers corresponding to the predetermined ID numbers match each other. In the case of the address block arrangement pattern of the present embodiment, the comparator 1 (66), the comparator 2 (67), and the comparator 3 (6)
8) If at least one of the results of the comparator 4 (69) is “match”, the track currently being reproduced is a groove track, and if at least one result is “mismatch”, it is a land track. Can also be determined. That is,
It is not necessary that all address blocks can be read accurately. If information in at least one of the inner address blocks ID1 or ID3 and information in at least one of the outer address blocks ID2 or ID4 can be read as address signals. It is possible to distinguish between a land and a groove.

Even if the address correction unit 71 is added as shown in FIG. 17B, it is possible to determine whether the track being reproduced is a land or a groove. In this case, during land reproduction, memory 1
# 62 for (62), # 100 memory 3 for memory 2 (63)
Since # 101 is input to (64) and # 100 is input to the memory 4 (65), the outputs of the comparators 1 to 4 are "matched" at the time of land track reproduction, so that the outputs of all comparators are When it becomes “match”, it may be determined as a land track. If the outputs of all the comparators are “mismatched”, the outputs of all the comparators are “mismatched” at the time of groove track reproduction. Therefore, if “mismatch” is detected, it can be determined that the track is a groove track.

When the address signal can be read only from the inner address blocks ID1 and ID3 or only the outer address blocks ID2 and ID4, it is impossible to identify the land and the groove. In such a case, the determination unit 70 may output a signal indicating that identification is impossible (L / G OK signal). In general, sector addresses are read out once every few milliseconds due to the rotation of the disk.Therefore, there is a high probability that land / groove identification will not be possible for all sector addresses over a long period of time. The number of lands and grooves can be identified without any practical problems by the above operation.

In addition, although the address address is incorrectly determined to be normal by the CRC determination unit despite the fact that it is actually the wrong address,
When the signal is input to the land / groove identification unit, the output of the comparator is divided into “match” and “mismatch”. Also in this case, a signal (L / G
OK signal).

Further, if the land / groove identification signal (L / G signal) of the land / groove identification section 61 is inputted to the address correction section 44 of the embodiment (Embodiment 7) of FIG. Therefore, it goes without saying that land and groove identification and address value output can be performed simultaneously.

Embodiment 9 Next, still another embodiment of the optical disk recording / reproducing apparatus according to the present invention will be described.

FIG. 18 is a block diagram of the device of this embodiment. In FIG. 18, 31 is a disk, 32 is a disk motor, 33 is an optical head, 34 is an address reproducing unit, 81 is a tracking error signal detecting unit, which is composed of a differential circuit 82 and an LPF (Low Pass Filter) 83. 84 is a phase compensator, and 85 is a head driver.
90 is a timing generator, 91 is an outer value sample and hold unit, 92 is an inner value sample and hold unit, 93 is an addition circuit, 94
Is a gain conversion unit.

Using the optical disk recording / reproducing device as described above,
The operation of detecting a shift amount (off-track amount) between a light spot and a track in a sector address area where no address block is arranged as in FIG. 14 will be described.

First, the optical head 33 in FIG. 18 irradiates the disk 31 with laser light, and detects a reproduction signal (RF signal) from the amount of reflected light. The operation of extracting the address number and ID number for each address block by the address reproducing unit 34 is the same as the operation described in the conventional example.

FIG. 19 is a schematic diagram showing a change in the tracking error signal (TE signal) in the off-track state in the sector address area 5. As described in the second embodiment, the level of the TE signal changes substantially in proportion to the distance between the light spot and the address pit, and the direction of the level change is determined by the positional relationship between the light spot and the address pit. Here, when the light spot 24 passes through the outer peripheral side of the address pit 25, the TE
It is assumed that the signal becomes a negative value and becomes a positive value when passing through the inner peripheral side. When the light spot 24 passes through the line (a) of the track 2, since the distance between the light spot 24 and the address pit 25 is relatively short in ID1 and ID3, the level fluctuations VTE1 and VTE3 of the TE signal are small and negative values. Becomes In this case, the distance between the light spot 24 and the address pit 25 is large in ID2 and ID4, so that the TE signal level change VTE2,
VTE4 increases and becomes a positive value. Therefore, FIG.
A TE signal as shown in FIG. In addition, light spot 24
When light passes through line (b) of track 2, a light spot
Since the distance between 24 and the address pits 25 of ID1 to ID4 is equal, the level fluctuation amount is the same for all of ID1 to ID4. Therefore, a TE signal as shown in FIG. 19B is obtained.
Further, when the light spot 24 passes through the line (c) of the track 2, a TE signal as shown in FIG. 19 (c) is obtained. As can be seen from FIG. 19, VTE1 (or VTE3) and VTE2
Since the magnitude of (or VTE4) changes, the off-track amount can be estimated from the difference between the change values. That is, the off-track amount is obtained by the equation Voftr = VTE1-VTE2. If the light spot 24 passes through the center line (b) of the track 2, VTE 1 -VTE
2 = 0, if the signal passes through track 2 line (a), VTE1-
VTE2 <0, VTE1 if passing through line (c) of track 2
−VTE2> 0, and the direction and magnitude of the off-track amount can be obtained.

Next, the operation of the timing generator 90 of FIG. 18 will be described.
FIG. 20 is a timing chart of the gate pulse signals (GT0 to GT2) generated by the timing generator 90. Since the read address signal is input to the timing generator 90 from the address reproducer 34, the gate pulse signal GT1 synchronized with the outer address block based on the input address signal and the inner address block And a gate pulse signal GT2 synchronized with. The gate pulse signal GT1 is a signal for sampling the signal of the outer value sampling and holding unit, and the gate pulse GT2 is a signal for sampling the signal of the inner value sampling and holding unit.

First, FIG. 20A shows a case where ID1 can be read. If ID1 can be read, the timing of appearance of ID2, ID3, and ID4 can be known, so first, a signal GT0 including a gate pulse synchronized with the end of ID1 is generated. In this case, gate pulse signals GT2 and GT1 for the inner address block ID3 and the outer address block ID2 (ID2 may be ID4) are generated, respectively. Therefore, the timing generator 90
Is the gate pulse signal GT1 from the gate pulse signal GT0
The gate pulse signal GT2 is generated at a timing delayed by the time T2 from the gate pulse signal GT0.

Next, (b) of FIG. 20 shows a timing chart when ID1 cannot be read and ID2 can be read. A gate pulse signal GT0 synchronized with the end of ID2 is generated. In this case, it is necessary to generate the gate pulse signal GT2 and the gate pulse signal GT1 for the inner address block ID3 and the outer address block ID4, respectively.
A value of 0 generates the gate pulse signal GT1 at a timing delayed by the time T2 from the gate pulse signal GT0, and generates the gate pulse signal GT2 at a timing delayed by the time T1.

Next, FIG. 20C shows a case where a sample-hold gate pulse signal is generated in synchronization with another gate pulse signal synchronized with the sector address area. If GT0 is another gate pulse signal and a signal that rises immediately before the sector address area, the inner peripheral address block ID
1.To generate the gate pulse signals GT2 and GT1 for the outer address block ID2, the timing generator 90
GT1 is generated at a timing delayed by T4 from 0, and GT2 is generated at a timing delayed by T3 from the gate pulse signal GT0.

Gate pulse signal GT generated by timing generator 90
1. If GT2 is used, in the example of FIG. 20A, the TE signal level VTE2 in the outer address block ID2 is synchronized with the gate pulse signal GT1 and the outer value sample and hold unit 9 is used.
The TE signal level VTE3 in the inner address block ID3 is stored in the inner sample hold unit 92 in synchronization with the gate pulse signal GT2. As a result, the differential circuit 93
Outputs the value of (VTE1-VTE2). Since this value corresponds to the off-track amount, the gain conversion unit 94
By adjusting the level to the level of the TE signal, an off-track signal (OFTR signal) can be obtained. In the actual tracking control system, even if the TE signal is controlled to be 0, the tracking error signal detection unit 81 and the phase compensation unit 8
4, due to the offset generated in the head drive unit 85, etc.
In practice, a situation occurs where the light spot is not at the center of the track. Therefore, by adding the OFTR signal as offset correction of the tracking control system as shown in FIG. 18, the light spot can be positioned at the track center. Fig. 20
The same applies to cases (b) and (c).

It is sufficient to generate a gate pulse signal GT2 synchronized with any of the inner address blocks and a gate pulse signal GT1 synchronized with any of the outer address blocks. is not. In addition, it is not necessary to manage the time T1 and the time T2 at an accurate time interval that synchronizes with the position of a specific address pit in the address block. However, the pit arrangement pattern is the same in each address block (for example, VFO). region)
Is preferably measured.

In this example, the number of address blocks to be sampled and held is one inner address block and one outer address block. However, the average value of a plurality of inner address blocks and the average value of a plurality of outer address blocks are set. If the off-track signal is detected by using, the average value can be detected even if there is local undulation of the track.

Embodiment 10 Next, still another embodiment of the optical disk recording / reproducing apparatus according to the present invention will be described.

FIG. 21 is a block diagram of the device of this embodiment. In FIG. 21, 31 is a disk, 32 is a disk motor, 33 is an optical head, 34 is an address reproducing unit, 81 is a tracking error signal detecting unit, 84 is a phase compensating unit, and 85 is a head driving unit. 90 is a timing generator, 91 is an outer value sample and hold unit, 92 is an inner value sample and hold unit, 93 is a differential circuit,
94 is a gain conversion unit. Reference numeral 100 denotes a reflected light signal detection unit, which includes an adding circuit 101 and an LPF (Low Pass Filter) 102.

In FIG. 21, 31, 32, 33, 34, 81, 84, 85, 90, 91, 92,
93. The same operation as that described in the ninth embodiment is performed. In the ninth embodiment, the TE signal is sampled and held to detect the off-track amount, whereas in the tenth embodiment, the reflected light amount signal (AS signal) detected by the reflected light amount signal detection unit 100 is sampled and held and the off-track amount is detected. The difference is that the amount is detected.

In the reflected light amount detection unit 100, the output of the two-divided photodetector of the optical head 33 is added by an addition circuit 101, and the addition signal is further added to the LPF10.
2 (band is higher than tracking control band, but lower than RF signal, several tens to several hundreds KHz) Through high frequency components, high frequency components are removed to represent the average reflected light amount
Detect AS signal.

FIG. 22 is a diagram showing a change in an AS signal with respect to a shift amount between a light spot and a track. As described in Example 2,
The RF signal changes depending on the position where the light spot 24 passes, as shown in FIGS.
8A and 8B. Since the AS signal indicates the average level of the RF signal, the AS signal in FIG. 22 corresponds to the lines (a), (b), and (c) through which the light spot 24 passes in FIG. And an AS signal as shown in (c) is obtained. Therefore, as in the ninth embodiment, VAS1, VAS2, etc. are sampled and held in synchronization with the inner address block and the outer address block, and the difference (VAS1-VAS2) is obtained. Can be detected. Here, the timing generator 90 generates the gate pulse signals GT1 and GT2 to be sampled and held as described in the ninth embodiment. However, the timing of generating the gate pulse signal is the same as the AS where the pit pattern is the same in each address block.
Since more accurate detection can be made by sampling the signal, it is preferable to use the AS signal in the VFO section, the AM section, or a specially provided pit section.

Further, similarly to the ninth embodiment, the off-track signal (OFTR signal) detected using the AS signal can be used for offset correction of the tracking control system.

Although the AS signal obtained by passing the RF signal through the LPF is used here, the same applies when the envelope level (VRF3 and VRF4 in FIG. 22) on the lower side of the RF signal (the side where the amount of reflected light is small) is used. is there.

Embodiment 11 Next, still another embodiment of the optical disk according to the present invention will be described.

The outline of the arrangement of the address blocks in both the sector addresses on the optical disc of this embodiment is the same as that shown in FIG. 10A. However, as shown in FIG. 23, in the optical disk of the present embodiment, instead of placing an interval (ΔX1) between adjacent address blocks, the last pattern of each address block is prevented from becoming a pit, and the next address The data arrangement is such that the head pattern of the block does not become a pit. In particular, in the head pattern of the address block, non-pit data (length ΔX1) longer than the rotation accuracy (ΔX) at the time of cutting the disk master is arranged.

As shown in FIG. 10B, when the address blocks are shifted in the circumferential direction, the space between the address blocks is wasted, but according to the optical disc of the present embodiment, such a problem does not occur.

With reference to FIGS. 24A, 24B, 25A and 25B, advantages of the optical disc of the present embodiment will be described in detail. In the data arrangement of the address blocks shown in FIGS. 24A and 24B, the last pattern of the address block is a pit, and the leading end pattern of the next address block is also a pit. See Figure 24A for details.
Indicates the pit shape expected from the design in the case of such a data array. In FIG. 24A, the last pit of the address block 113 and the first pit of the address block 114 are arranged along the center line of each address block.
It is formed to have a prescribed length. However, in reality, in the cutting process of the master disc, when address pits are formed while displacing the radial position of the laser beam spot in the sector address area 5,
Last pit of address block 113 and address block 1
As shown in FIG. 24B, 14 leading pits are formed continuously. This is because the optical disk is irradiated with the laser beam even while the laser beam spot for cutting is displaced in the radial direction from the address block 113 to the address block 114. As a result, FIG.
As shown in (1), pits having an unexpected shape are formed, and it becomes difficult to correctly reproduce data.

In order to solve this problem, the inner address pits and the outer address pits may be cut with different laser light beams. However, this method complicates the cutting device.

FIGS. 25A and 25B show a pit reading operation when the light spot 24 scans so as to reproduce the data of the land track 111. FIG. FIG. 25A shows a sector address area in the case where the pit arrangement at the connection between address blocks is not particularly defined. In the sector address area of FIG. 25A, the adjacent address blocks 114 and 117 overlap in the circumferential direction by a length corresponding to the cutting accuracy ΔX,
The top of 114 is the pit data. In this case, Figure 2
As shown in FIG. 5A, when the pit data at the head of the address block 114 overlaps the non-pit data at the end of the address block 117, the light spot 24 is moved along the center line of the land track 111 while the address block is moved. When playing 117 data, address block 1
17 causes a data error. This is the address block 114
Pit data at the beginning of the address block 117
Is erroneously determined to have pit data at the end.

On the other hand, FIG. 25B shows a sector address area on the optical disc of this embodiment. In this optical disc, non-pit data is arranged at the beginning and end of an address block. When the head of the address block 114 is not pit data as shown in FIG. 25B, even if the non-pit data of the last data of the address block 117 and the non-pit data of the head of the address block 114 overlap, the reproduced signal is not pit data. Therefore, no data error occurs in the address block 117. Although the number of non-pit data at the head of the address block 114 cannot be detected correctly,
Generally, the beginning of an address block is a VFO area, and it is not necessary to read all data.
If the address data section is resynchronized in the AM area after the VFO area and the address number and CRC can be correctly recognized, no problem occurs in the operation of reading the address block.

Therefore, as shown in FIG. 25B, by setting the first pattern and the last pattern of each sector address block to be non-pit data, pit formation failure during cutting of the disc master between address blocks arranged wobbled. In addition, it is possible to prevent an error in reading address data due to overlapping of address blocks at the time of reproducing sector addresses, and also to reduce useless gaps.

Embodiment 12 Still another embodiment of the optical disc according to the present invention will be described.

FIG. 26A is a layout diagram of the address blocks of the optical disk of the present embodiment, which is the same as that of the second embodiment, where 110 and 112 are groove tracks, 111 is land tracks, 113, 114, 115 and 11
6, 117, 118, 119 and 120 are address blocks, and 24 is a light spot. FIG. 26B shows the arrangement of data in each address block. ID1 address block 117 is VF
It is composed of data of O1 (300), AM (301), address number (302), ID number (303) and CRC1 (304), and the address block 114 of ID2 is VFO2 (305), AM (306), address Number (307), ID number (308), and CRC2 (309).

The difference between the optical disc of the present embodiment and the optical disc of the second embodiment is that in the present embodiment, the VF of the address block 117 of ID1 is used.
The length of O1 is about 1.5 to 3 times longer than the VFO of the address blocks of ID2, ID3 and ID4.

When the sector address area is irradiated with the light spot 24,
The data is reproduced in the order of ID1 data and ID2 data. At this time, while the data area 6 is constituted by the track groove, while the sector address area 5 is constituted by the mirror surface on which the address pit is formed, as shown in FIGS. 8A and 8B, the reproduction signal ( DC signal component (DC level) of RF signal)
Are different between the data area 6 and the sector address area 5. As a result, immediately after the light spot 24 moves from the data area 6 to the sector address area 5, a sudden level change of the RF signal occurs. Even if such level fluctuations occur, it is necessary to improve the reproducing circuit in order to read data accurately. However, even if the reproducing circuit is improved, the influence of the level fluctuation of the RF signal cannot be completely removed at the boundary between the data area 6 and the sector address area 5. For this reason, ID1
In this case, it takes longer time to lock the PLL in order to match the phase of the data read clock and the data (VFO1) than when there is no level change. For ID2 and later, RF
The effect of signal level fluctuations is reduced,
PLL locking in VFO is faster.

If the data lengths of all the address blocks are to be the same, the VFO lengths of ID2 to ID4 need to match the VFO length required for ID1. for that reason,
The length of the VFO from ID2 to ID4 becomes longer than necessary, and waste increases. Therefore, in the present embodiment, by making only the length of the VFO in ID1 longer than the length of the VFO in ID2, ID3 and ID4, the VF required for each address block is increased.
This makes it possible to optimally set the length of O, thereby reducing unnecessary data and maintaining the accuracy of address reading.

Note that the length of VFO1 (300) in ID1 and the length of VFO2 (30
5) Since the difference in length is smaller than the data length of the one-sector address area, it hardly affects the average value of the tracking error signal in the sector address area described in the first embodiment.

Embodiment 13 With reference to FIG. 27, still another embodiment of the optical disc according to the present invention will be described. FIG. 27 shows the address area 405. The address block 411 provided in the address area 405 is recorded so as to extend over both the groove track 403 and the land track 402 around the boundary line 409 between the groove track 403 and the land track 402 on the outer periphery. Take different values in the address space.
Since the address block 411 is commonly included in the address areas of the adjacent land track 402 and groove track 403, the data area is identified by the same address block 411. The track identification mark 412 is used to identify the groove track 403 from the land track 402 having the same address block 411 or to identify the land track 402 from the groove track 403, and the center (408 or 408) of one of the tracks is used. 410).
Here, the track identification mark 412 is the groove track 4
It is provided on the track center 408 of 03.

As a result, when the data of the groove track 403 is reproduced, the track identification mark 412 is reproduced, and when the data of the land track 402 is reproduced, the track identification mark 412 is not reproduced. These tracks 402 and 403 have the same address block 411, but depending on whether or not the track identification mark 412 is subsequently reproduced, whether the track currently being reproduced is a land track,
It is possible to identify whether the track is a groove track.

In FIG. 27, a track identification mark 412 is arranged after the address block 411 in order to easily and accurately detect the gate pulse signal generated based on the address block 411. That is, the track identification mark 412 is reproduced temporally after the address block 411 in the reproduction signal.

Since the playback signal differs depending on the track,
The land track 402 and the groove track 403 can be identified only from the reproduction signal, and recording and reproduction on a desired track can be performed using only the reproduction signal regardless of the correspondence between the groove shape and the tracking polarity.

Although the track identification mark 412 is recorded on the groove track 403 in the above example, the land track 402
It is clear that a similar effect can be expected by recording above.

FIG. 28 is a configuration diagram of another embodiment of the optical disk recording / reproducing apparatus according to the present invention. The optical disk recording / reproducing apparatus shown in FIG. 28 records or reproduces information on or from the optical disk shown in FIG. In the following, a description will be given of the track designating means as the CPU 601 and the track identification mark reproducing means as the track identification mark reproducing circuit 604.

In FIG. 28, the circuits denoted by 601 and 605 to 612 are:
The same operation as the operation described in the first embodiment is performed. ID playback circuit
An address reproducing circuit 602 reproduces an address block 411 from a signal digitized by the binarizing circuit 605.
03 and a track identification mark reproducing circuit 604 for reproducing the track identification mark 412.

FIG. 29 is a configuration diagram of a track identification mark reproducing circuit 604 for reproducing the track identification mark 412 from the optical disc having the address area of FIG. 701 is a flip-flop, 70
2 is a delay element. The signal b is a track identification signal, the signal c is a binarized reproduction signal, and the signal d is a gate pulse signal based on the reproduced address.

The logical address for identifying the data area is represented by an address common to the land track 402 and the groove track 403 (reproduced by the address reproducing circuit 603) and a 1-bit track identification signal for identifying the land track 402 and the groove track 403. Shall be.

FIG. 29 shows the track identification mark reproducing circuit 604 when the track identification mark 412 is composed of one bit. The track identification mark reproducing circuit 604 is composed of a flip-flop 701 and a delay element 702. The delay element 702 delays an address detection signal d indicating that the immediately preceding address has been reproduced by a predetermined time, and reproduces only the gate section. This is a circuit for taking the signal c into the flip-flop 701. This circuit reproduces a track identification mark 412 (1 bit) reproduced with a certain time delay after the address reproduction. Here, the track identification mark 412
, The most significant bit of the logical address is obtained.
When the reproduced track identification mark 412 is composed of a plurality of bits, a predetermined land track 402 is used.
Alternatively, a track identification signal may be generated by comparing the mark with the mark representing the groove track 603, and may be set as the most significant bit of the address.

The data reproduction circuit 612 compares the address reproduced by the ID reproduction circuit 602 with the address given from the CPU 601, and if they match, reproduces the data after a fixed time from the address reproduction.

Finally, if the reproduced address is different, the CPU 601 searches for the track again. However, if the most significant bits of the address are different, a half track jump is performed, and the track selection signal for selecting the tracking polarity is inverted. That is, in the above example, the case where only the highest order of the addresses is different means that there is an address common to the land track and the groove track, but the selection of the land track or the groove track is incorrect. In order to correct this, the tracking polarity is switched by inverting the track selection signal for selecting the track polarity.

When the groove track of the optical disk shown in FIG. 27 is reproduced by the above-described apparatus, the laser beam scans substantially the center 408 of the groove track and reproduces the address block 411 and the track identification mark 412. When a land track is reproduced, the laser beam scans substantially the center 410 of the land track and reproduces only the address. Since the reproduction signal in the address area differs depending on the track to be reproduced in this manner, the land track 402 and the groove track 403 can be identified only from the reproduction signal, and only the reproduction signal is used regardless of the correspondence between the groove shape and the tracking polarity. Recording and reproduction on a desired track becomes possible.

According to the recording / reproducing apparatus described above, the polarity of the tracking can be automatically switched by the reproduction signal for the track identification mark.
Common tracking is possible regardless of the characteristics of the reproducing apparatus. Therefore, compatibility can be improved in the optical disc recorded on both the land track and the groove track.

Embodiment 14 FIG. 30 shows an address area 405 in still another embodiment of the optical disc according to the present invention. The feature of this embodiment is that track identification marks 1101a, 1101b, 1101c, 1102a, 1102b, 1102c are arranged in the address area 405 of the optical disc in addition to the address blocks 411a, 411b, and 411c. .

The address area 405 of the optical disc shown in FIG. 30 is such that the address areas of adjacent tracks are aligned in the radial direction of the disc in accordance with the CAV or ZCAV (ZCLV) format.
Is formed. In the address area 405, an address block 411 is included in order to identify the subsequent data area 406.
a and 411b are provided. The address block 411b includes a groove track 403b and a land track 402b centered on a boundary 409 between the groove track 403b and the land track 402b.
, And different addresses are provided in different address areas. Address block 411b is groove track 403b and land track
Since it is provided at the center of 403b, the same address block 411b is given to the data area 406 of the adjacent land track 402b and groove track 403b in the present disk. Further, two track identification marks 1101b and 1102b are formed to be shifted from the center 408 of the groove track 403b by about 1/2 track width inward and outward. At this time,
Two track identification marks 1101b and 1102b existing in the same address area 405 have the same value. The two track identification marks are provided at successive positions in the track direction so as to be reproduced temporally continuously. Similarly, two track identification marks 1101a, 1102a, 1101c, 1102c are provided for the groove tracks 403a, 403c on the inner circumference side and outer circumference side of one track with respect to the groove track 403b.
At this time, a value different from the two track identification marks existing in the address area 405 adjacent in the radial direction is provided. For example, the track identification marks 1101a, 1102a, 1101c, 1102c of the groove tracks 403a, 403c are the same mark 1
(Marks indicated by oblique lines rising to the right in FIG. 30), and the track identification marks 1101b and 1101 on the adjacent groove track 403b are provided.
The mark 102b is provided with a mark 2 that is different from the mark 1 (a mark with a diagonally downward slant in FIG. 30). Here, it is assumed that the track identification mark is formed as 1-bit data (0 or 1), and pits representing 0 and 1 are provided alternately for each address area adjacent in the radial direction. Specifically, the track identification mark 11 is used for the groove track 403b.
01b and 1102b are provided as 1-bit pits, and pits are not provided as track identification marks 1101a and 1102c for adjacent groove tracks on the inner and outer circumferential sides. In the optical disc 401 shown in FIG. 30, track identification marks 1101 and 1102 are arranged after the address block 411 in order to easily and accurately detect the gate pulse signal created based on the address block 411. That is, the track identification marks 1101 and 1102 are reproduced temporally after the address block 411 in the reproduction signal.

As a result, when the data of the groove track 403b is reproduced, two track identification marks (1101b and 1102b) having the same value are reproduced in the address area 405, and when the data of the land track 402b is reproduced, the address Area 405
Two different track identification marks inside (1101b and 1102c)
Is played. These tracks 403b and 402b have the same address block 411b, but the track currently being reproduced is a land track or a groove track depending on whether the track identification marks to be reproduced subsequently match or not. Can be identified.

In the disc shown in FIG. 30, the first track identification marks 1101a, 1101b, and 1101c have the groove track 403b and the land track 40 adjacent to the outer periphery of the groove track 403b.
The second track identification mark 1102a, 1102b, 1102c is provided on the boundary 409 between the groove track 2b and the land track adjacent to the groove track 403b on the inner peripheral side of the groove track 403b.
It is provided on a boundary line 407 with 402a. However, the first track identification mark has a groove track 403b and a land track 402a adjacent on the inner peripheral side of the groove track 403b.
The same effect can be obtained in a disk provided with the second track identification mark provided on the boundary line 409 between the groove track 403b and the land track 402b adjacent on the outer peripheral side of the groove track 403b. .

Also, the case where two track identification marks provided in the address area on the groove track have the same position has been described, but the two track identification marks provided in the address area on the land track have the same value. In this case, the same effect can be obtained.

FIG. 31 is a configuration diagram of another embodiment of the optical disk recording / reproducing apparatus according to the present invention. Optical disc recording /
The reproducing apparatus records or reproduces information on or from the optical disk shown in FIG. In the following description, the track designating means will be described as the CPU 601, the track identification mark reproducing means as the track identification mark reproducing circuit 1201, and the track identifying means as the track identifying circuit 1202.

In FIG. 31, the circuits denoted by 601 and 605 to 612 are:
The same operation as the operation described in the first embodiment is performed.

The ID reproduction circuit 602 includes an address reproduction circuit 603 for reproducing the address block 411 from the signal digitized by the binarization circuit 605, a track identification mark reproduction circuit 1201 for reproducing the track identification marks 1101 and 1102, a land track 402 and a groove. It comprises a track identification circuit 1202 for identifying the track 403.

FIG. 32 is a configuration diagram of a track identification mark reproduction circuit 1201 for reproducing the track identification marks 1101 and 1102 from the optical disc 401 shown in FIG. 1701 is flip-flop, 13
02, 1303, 1304, and 1305 are delay elements.

FIG. 33 is a configuration diagram of a track identification circuit 1202 that generates a track identification signal b from two track identification marks 1101 and 1102 reproduced from the optical disc 401 shown in FIG.
1401 is a flip-flop holding the value of the first 1-bit track identification mark 1101, 1402 is a flip-flop holding the value of the second 1-bit track identification mark 1102, and 1403 is comparing the two track identification marks. The comparator 1404 is a flip-flop that holds the value of the track identification signal. 1405, 1406 and 1407 are the address detection signals d
Is delayed for a fixed time, so that a gate pulse signal for capturing the two track identification marks 1101 and 1102 and 2
A gate pulse signal for capturing a comparison result between the two track identification marks 1101 and 1102 is generated.

The logical address for identifying the data area is an address common to the land track 402 and the groove track 403 (reproduced by the address reproducing circuit 603) and one bit (for example, the most significant one bit) for identifying the land track 402 and the groove track 403. Of the track identification signal b.

FIG. 32 shows a track identification mark reproducing circuit 1201 when the track identification marks 1101 and 1102 are composed of one bit.
It is shown. Track identification mark reproduction circuit 1201
Is composed of a flip-flop 1301 and delay elements 1302 and 1303. The binarized reproduction signal c is delayed by a predetermined time by the delay elements 1702 and 1703 for the address detection signal d to generate a gate pulse signal. This is a circuit that takes in the reproduction signal into the flip-flop 1701 only in the section of the pulse signal. With this circuit, two 1-bit track identification marks 1101 reproduced with a certain time delay after address reproduction.
And 1102 are played.

The track identification circuit 1202 shown in FIG. 33 includes three flip-flops 1401, 1402, 1404, a comparator 1403, and a delay element 14.
05, 1406, and 1407. Address detection signal d
A gate pulse signal obtained by delaying the signal by a predetermined time by delay elements 1405, 1406, and 1407, and
The first track identification mark reproduced in 01 is loaded into the flip-flop 1401 and the second track identification mark is loaded into the flip-flop 1402. The comparator 1403 compares the two track identification marks, and compares the comparison result with the flip-flop 1404. It is a circuit to hold. That is, a gate pulse signal obtained by delaying the address detection signal d by the delay elements 1405, 1406, and 1407 for a predetermined time is supplied to clock terminals of the flip-flops 1401, 1402, and 1404. With this circuit,
When the two track identification marks match, a track identification signal for identifying the currently reproduced track is generated as a groove track, and when the two track identification marks are different, a land track is generated. The address of each data area is obtained as upper bits.

When the information in the address area of the optical disk shown in FIG. 30 is reproduced by the above-described apparatus, the laser beam scans the center 408 of the groove track in the groove track 403b, and the track identification mark having the same value as the address block 411b.
Play 1101b and 1102b. Also, 402b on land track
The laser light scans approximately the land track center 410, the address block 411b and two different track identification marks
Play 1101b and 1102c. As described above, since the reproduction signal for the track identification mark to be reproduced differs depending on the track, it is possible to identify whether the track currently being reproduced is the land track 402 or the groove track 403 from the reproduction signal alone, and the groove shape ( Recording and reproduction on a desired track can be performed using only a reproduction signal based on the correspondence between the tracking (groove track or land track).

According to the recording / reproducing apparatus described above, the tracking polarity can be automatically switched by the reproduction signal for the two track identification marks, so that common tracking can be performed regardless of the characteristics of the disc or the recording / reproducing apparatus. It is. Therefore, the compatibility of the optical disc recorded on both the land track and the groove track can be improved.

(Embodiment 15) Still another embodiment of the optical disk according to the present invention will be described.

FIG. 34 shows an address area 405 and a control information area 1502 of the optical disc of this embodiment. In FIG. 34,
402 is a land track, 403f is a groove track, 405 is an address area, 411 is an address block, and 1501 is a track identification mark.

Address block 4 provided in address area 405
11 is recorded so as to straddle both the groove track 403 and the land track 402 with the boundary line 409 between the groove track 403 and the land track 402 as a center, and different addresses are provided in all address areas. The data areas of the adjacent land track 402 and groove track 403 are identified by the same address block 411. The track identification mark 1501 is at least one land track at a specific position in the defined control information area 1502.
It is provided in the data area 406 on the track center 408 or 410 of either the track 402 or the groove track 403. The track identification mark 1501 is the land track 402 provided with the track identification mark 1501.
This is for identifying whether the track is a track track 403 or a groove track 403, and differs depending on whether the track track is provided on a land track or on a groove track. Here, a 1-bit track identification mark 1501 is provided.

As a result, when the track identification mark indicating the groove track is reproduced in the currently reproduced track, it can be understood that the polarity of the currently performed tracking is for reproducing the data of the groove track. Also, when the track identification mark representing the land track is reproduced, it can be understood that the polarity of the currently performed tracking is for reproducing the land track. Therefore, by reproducing the track identification mark 1501 from only the reproduction signal and detecting the pattern, the correspondence between the groove shape of the track being reproduced and the tracking polarity can be obtained.

In the optical disk 401 shown in FIG. 34, a track identification mark 1501 is arranged in the data area 406 after the address block 411 in order to easily and accurately detect the gate pulse signal generated based on the address block 411. That is, the track identification mark 1501 is reproduced temporally after the address block 411 in the reproduction signal. Although the track identification mark 1501 is recorded in the data area on the groove track 403 in FIG. 34, it is obvious that the same effect can be expected by recording in the data area on the land track 402.

Embodiment 16 FIG. 35 is a configuration diagram of still another embodiment of the optical disc recording / reproducing apparatus according to the present invention. The optical disk recording / reproducing apparatus shown in FIG. 35 records or reproduces information on or from the optical disk shown in FIG. In the following invention, the track designating means is described as the CPU 601, the track polarity determining means is described as the track polarity determining circuit 1601, and the track selecting signal correcting means is described as the track selecting signal correcting circuit 1602.

In FIG. 35, the circuits denoted by 601 and 605 to 612 are:
The same operation as the operation described in the first embodiment is performed. When a track provided with the control information area 1502 is reproduced, the track polarity discrimination circuit 1601 takes out the track identification mark 1501 from the reproduction signal from the data reproduction circuit 612, and reproduces the track as a land track or a groove track. Identify whether there is any, and obtain the correspondence between the designated track selection signal and the groove shape (land or groove) of the track,
It is determined whether or not the selection of the track is correctly performed, and a tracking determination signal is generated. The track selection signal correction circuit 1602 corrects the track selection signal from the CPU 601 according to whether the track polarity determination circuit 1601 selects the tracking.

FIG. 36 shows a control information area 1502 of the optical disc shown in FIG.
A track polarity discriminating circuit 16 for discriminating whether or not the tracking is correctly selected from the track identification mark 1501 (reproduced signal h) and the track selection signal i of the CPU 601.
FIG. 1 is an example of a configuration diagram of FIG. 1701 is an exclusive OR gate,
1702 is a flip-flop, and 1703 is a delay element.

FIG. 37 is an example of a configuration diagram of a track selection signal correction circuit 1602 that corrects the track selection signal i of the CPU 201 based on the track selection determination signal g for which the tracking polarity determination circuit 1601 has determined whether the tracking is correct. 1801 is an exclusive OR gate.

The operation of the optical disk recording / reproducing apparatus configured as described above when an optical disk is loaded will be described below.

When the optical disc is loaded, the recording / reproducing apparatus reproduces the control information area 1502 of the specific track provided with the track identification mark 1501. At this time, the CPU 601 outputs a track polarity identification signal k to the track polarity determination circuit 1601. When a logical address of a track including the control information area 1502 provided with the track identification 1501 is given to the CPU 601, a seek command for the target track is issued to the linear motor control circuit 607, and the linear motor 609 is driven to The optical head 610 is moved to the vicinity. Next, CPU60
1 is a track jump command or a track selection signal i corresponding to a land track or a groove track.
Is output to the focus tracking control circuit 608 to reach the target track. In the focus tracking control circuit 608, when a track selection command is given, the polarity of the tracking control is switched to jump a half track, and focus and tracking are performed on a target track.

The logical address for identifying the data area is an address common to the land track 402 and the groove track 403 (reproduced by the address reproducing circuit 603) and one bit for identifying the groove track and the land track (for example, the most significant one).
Bit) of the track selection signal.

The data reproducing circuit 612 compares the address reproduced by the ID reproducing circuit 602 with the address given from the CPU 601, and if they match, reproduces the data after a fixed time from the address reproduction. Track identification mark 15 when loading disc
The control information area 1502 of the track provided with 01 is reproduced.

FIG. 36 shows a track polarity discrimination circuit 1601 when the track identification mark 1501 is composed of one bit. For example, when the track identification mark 1501 (reproduction signal h) indicates 1, the track identification mark 1501 is recorded on the groove track 402, and when the track identification mark 1501 (reproduction signal h) indicates 0, the track identification mark 1501 is recorded on the land track 402. Also, CPU601
Output a 1 as a track selection signal i when selecting the groove track 403, and output 0 when selecting the land track 402. The exclusive OR gate 1701 in FIG. 36 detects an error in track selection when the track selection signal i and the reproduced track identification mark 1501 (reproduction signal h) are different. That is, even though the groove track is selected by the track selection signal i (when the track identification signal is 1), the actual tracking is performed by the land track (when the track identification mark is 0) rather than the track identification mark 1501. Is determined, the selection of the track is incorrect, and the error is detected by taking the exclusive OR of the two signals. Track polarity discrimination command signal k from CPU 601
And the address detection signal d from the address reproducing circuit 603 is used as a gate pulse signal for fetching the result of the right / wrong track selection into the flip-flop 1702. Delay element 1703
In order to generate a gate pulse signal for capturing a signal indicating the correctness of the track selection, the address detection signal d
Is delayed for a certain time.

The track selection signal correction circuit 1602 in FIG. 37 performs erroneous tracking based on the track selection signal i.
The correction is performed based on the track polarity determination signal g. If the wrong track is selected, the track polarity discrimination signal g
, The track selection signal i is inverted and applied to the focus tracking control circuit 608. The exclusive OR gate 1801 in FIG. 37 performs this inversion operation.

When a disc is loaded or the drive is started, the data of the track provided with the track identification mark 1501 is reproduced, and the flip-flop 1702 in the tracking polarity discrimination circuit 1601 stores the discrepancy between the track selection signal of the CPU 601 and the tracking polarity. Therefore, since the tracking is selected based on the track polarity discrimination signal g in the selection of the tracking in the subsequent data reproduction and recording, normal tracking is always performed.

For this reason, in an optical disc in which at least one track identification mark 1501 is provided in the control information area 1502 as shown in FIG. 34, in order to obtain the correspondence between the polarity of the groove track and the land track and the track selection signal output by the CPU 601 in advance. Recording and reproduction on a desired track can be performed regardless of the correspondence between the groove shape and the tracking polarity. Also, only one track has a track identification mark.
Since the tracking polarity can be corrected by providing 1501, the recording capacity can be obtained as compared with the case where the track identification marks are provided in all the address areas.

According to the optical disk and the recording / reproducing apparatus described above, the polarity of tracking can be automatically switched by the reproduction signal for the track identification mark.
Common tracking is possible regardless of the characteristics of the disc and the recording / reproducing device. Therefore, in the optical disc recorded on both the land track and the groove track,
Compatibility can be improved.

It is clear that all the above embodiments can be used for a phase change optical disk or a magneto-optical disk.

Further, in the above embodiment, the optical disk having two or four address blocks in the sector address area has been described.
One or five or more address blocks may be provided.
As the number of address blocks increases, the accuracy of address reading improves, and the accuracy of land / groove determination improves.

INDUSTRIAL APPLICABILITY As described above, according to the present invention, in an optical disc capable of recording and reproduction on land tracks and groove tracks,
By providing a plurality of address blocks in one sector address area and arranging them alternately on the inner and outer circumferences in the radial direction with respect to the track center, even if the light spot is out of track, the sector Address reading can be reliably performed, and at the same time, disturbance of tracking control due to a level change of a tracking error signal in a sector address area can be reduced. This provides an optical disc that is less likely to cause an address signal reading error.

Further, according to the optical disk recording / reproducing apparatus using the above-mentioned optical disk, when reproducing the information of the wobbled address block, the read address number is changed to the overlapping order number (ID number) depending on whether the track is a land track or a groove track. , A different address number can be read for each address block within one sector address to obtain an accurate address value.

Also, in the optical disk recording / reproducing apparatus using the above optical disk, when reproducing the data of the wobbled address block, the address number corresponding to the overlapping order number of the inner address block and the address number corresponding to the overlapping order number of the outer address block are read. Is determined, it is possible to identify whether the current track is a land track but a groove track.

Further, by detecting the difference between the tracking error signal or the reflected light amount signal in the inner address block and the tracking error signal or the reflected light signal in the outer address block, a true off-track between the light spot and the track is detected. By detecting the amount, and correcting the tracking error signal using this off-track amount,
A tracking control system capable of always positioning the light spot at the center of the track can be realized.

Further, since the offset of the tracking signal occurs symmetrically when the laser beam spot passes through the address, tracking is stabilized even during address reproduction.

Continued on the front page (72) Inventor Yoshito Aoki 2-26-3 Yakumokitacho, Moriguchi-shi, Osaka Matsuno-ryu Room 203 (72) Inventor Shunji Ohara 218 Shinjo, Higashi-Osaka-shi, Osaka (72) Inventor Takashi Ishida Kyoto 13-14 Hashimoto, Hachiman-shi, Fuwa 6-176404 (JP, A) JP-A-8-221821 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) G11B 7/00 G11B 11/10 G11B 20/12

Claims (11)

(57) [Claims] 1. An optical disk having a plurality of sectors on both a land track and a groove track, each of the plurality of sectors has a sector address area and a data area, and the sector address area has a plurality of address blocks. Each of the plurality of address blocks has a portion indicating an address number for identifying a corresponding sector among the plurality of sectors from other sectors, and a portion for identifying from the other address blocks. A plurality of address blocks in the sector address area, the plurality of address blocks being formed at positions shifted by about half the track pitch in the inner circumferential direction of the disk with respect to the track center axis. At least one address block and a position shifted by about half the track pitch in the outer circumferential direction Have been provided and at least one address block, the sector address regions adjacent, share at least one address block, the optical disc. 2. The optical disk according to claim 1, wherein the same number of the address blocks are arranged at a position shifted toward the inner circumference and a position shifted toward the outer circumference of the disk with respect to the track center axis. 3. The optical disk according to claim 2, wherein the number of the address blocks is four. 4. A plurality of address blocks arranged in the sector address area, wherein a comparison result of address numbers of address blocks shifted to an inner side and an outer side of a sector address area of a land track, The address numbers are arranged so that the comparison result of the address numbers of the address blocks shifted to the inner side and the outer side of the sector address area of the groove track adjacent to the sector address area of the track is different. 4. The optical disc according to 3. 5. In the sector address area, a plurality of address blocks located on the inner side all have the same address number, and a plurality of address blocks located on the outer side all have the same address number. The optical disc according to claim 4, wherein 6. In the sector address area, a difference between an address number of an inner address block and an address number of an outer address block is equal to the number of sectors included in one track round. 6. The optical disk according to claim 1, having a sector address area in which address numbers are arranged as described above. 7. A space is formed in the circumferential direction between two adjacent address blocks which are shifted in the inner circumferential direction and the outer circumferential direction, respectively.
4. The optical disc according to 2 or 3. 8. The optical disc according to claim 7, wherein the length of the interval is longer than the disc rotation accuracy in a laser cutting step for producing a disc master. 9. Two adjacent address blocks which are shifted in the inner circumferential direction and the outer circumferential direction, respectively, are provided at ends adjacent to each other in the respective address blocks, regardless of the identification of the address number. 4. The optical disk according to claim 1, wherein the optical disk has information. 10. A non-pit data at two adjacent address blocks shifted in the inner circumferential direction and the outer circumferential direction, respectively, at ends adjacent to each other in each address block. 4. The optical disc according to 2 or 3. 11. The optical disk according to claim 10, wherein a length of said non-pit data is longer than a disk rotation accuracy in a laser cutting step for manufacturing a disk master.