JP3025499B2 - Optical disk recording / reproducing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an optical disk and an optical disk 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 / playback using the optical disk.
Reproduction equipment.

[0002]

2. Description of the Related Art Optical discs have excellent interchangeability and random access properties, and the range of applications in various information equipment fields such as personal computers is expanding more and more. Demands are even higher. 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 a rewritable optical disk that is currently in widespread use, a groove-shaped track of 1 to 1.6 μm (each having a width of about 50%) is spirally formed on a disk-shaped substrate, and a recording material is formed on the track surface. (In the case of a phase change optical disk, a thin film having a component of Ge, Sb, Te, etc.) is 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. The optical disc having the above structure is irradiated with a light beam at a predetermined recording power on one of a concave track and a convex track, and records information 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.

[0003] In recent years, the capacity of information data handled in various fields has been further increased, and it has been desired to increase the capacity of optical discs. The recording density can be increased by reducing the width of each track (hereinafter, referred to as track pitch). However, if it is attempted to achieve a recording density of about twice the conventional recording density, the track pitch is reduced to the conventional track pitch. It is necessary to make the track pitch 1/2 of the track pitch, but it is very difficult from the manufacturing method to make a stamper with a stable width for concave and convex tracks of half the track pitch and duplicate the disc. is there. 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 disk on which information is recorded on both concave and convex tracks, if a sector address for identifying a sector is separately provided for each track, it is necessary to form two addresses or concave tracks at the same time. Therefore, two or more laser beams are required, and a complicated device is required. Therefore, an intermediate address 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. 6-176404). 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 facilitates cutting of the master. However, in this case, there are two tracks for the same address as viewed from the recording / reproducing device,
They need to be clearly distinguished in some way.

Hereinafter, a conventional optical disk and an optical disk recording / reproducing apparatus using the above-mentioned 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 groove track, 209 is a land track, and 210 is a light spot.

Here, the groove track 208 and the land track 209 have the same track pitch Tp, and the center of each address pit 206 is shifted from the center of the groove track 208 by Tp / 2 in the disk radial direction. Are located.

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

[0009] 200 is a disk, 201 is a track,
210 is a light spot, 211 is a disk motor for rotating the disk 200. An optical head 212 optically reproduces a signal on the disk 200 and includes a semiconductor laser 213, a collimating lens 214, an objective lens 215, a half mirror 216, a light receiving unit 217, and an actuator 218. 220 is the light spot 21
A tracking error signal detection unit that detects a tracking error signal indicating the amount of radial displacement between 0 and the track 201 is configured by 221 differential circuits and 222 LPFs (low-pass filters). 223 is a phase compensator for generating a drive signal for driving the optical head from the tracking error signal, and 224 is an optical head 21 based on the drive signal.
2 is a head driving unit that drives the actuator 218 in the second actuator 2. 225 is an addition circuit of the signal from the light receiving unit 217,
26 is a waveform equivalent part for preventing inter-symbol interference of a reproduced signal, 227
Is a data slice unit for binarizing the reproduced signal at a predetermined slice level, 228 is a PLL (Phase Locked Loop) for generating a clock synchronized with the binarized signal, and 229 is AM.
(AM) detecting section for detecting (Address Mark), 230 is a demodulator for demodulating the reproduced signal, 231 is a switch for separating the demodulated signal into data and address, and 232 is a CRC (Cyclic Redundancy) for performing error discrimination of the address signal. Check)
The determination unit 233 is an error correction unit that performs error correction on the data signal. Reference numeral 234 denotes an address reproducing unit composed of 225 to 232. CRC is an error detection code generated from the address number and the ID number.

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

Hereinafter, the tracking control operation will be described. The laser light emitted from the semiconductor laser 213 is collimated by the collimator lens 214 and condensed on the disk 200 via the objective lens 215. Disk 200
The laser light reflected by the light source returns to the light receiving portions 217a and 217b via the half mirror 216, and the light spot 2 on the disk
The light amount distribution determined by the relative position between the track 10 and the track 201 is detected as an electric signal. Light receiving unit 21 divided into two
In the case where 7a and 217b are used, the difference between the light receiving sections 217a and 217b is detected by the differential circuit 221 and the low frequency band of the differential signal is extracted by the LPF 222 to detect the tracking error signal. In order for the light spot 210 to follow the track 201, the tracking error signal is 0 (the light receiving unit 2).
17a and 217b), a drive signal is generated by the phase compensator 223, and the actuator 218 is moved by the head driver 224 according to the drive signal to control the position of the objective lens 215. Is realized.

On the other hand, the light spot 210 is
In the track mark 207 and the address pits 206, light interferes with each other to reduce the amount of reflected light and reduce the output of the light receiving unit 217. In the portion without pits, the amount of reflected light increases and the output of the light receiving unit 217 increases. Will be higher. 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 adder circuit 225, passes through a waveform equalizing unit 226, and is binarized at a predetermined slice level in a data slice unit 227 to “0”, “1”. Is converted to a signal sequence. Data and a read clock are extracted by the PLL 228 from the binary signal. In the demodulator 230,
The modulated and recorded data is demodulated and converted to 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 an AM signal for identifying an address portion from a signal sequence constantly output from the PLL 228, the switch 231 is switched, and the demodulated data is processed as an 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 reproduction signal (R) when the light spot 210 passes through the sector address area 203 in the above configuration.
2 shows the state of an F signal) and a tracking error signal (TE signal). In the data area 204, the light spot 210 is located at the center of the track.
Immediately after entering into the optical path 03, a sharp displacement occurs between the light spot 210 and the address pit 206, so that the level of the TE signal largely fluctuates. The light spot 210 cannot suddenly follow the address pits 206, but gradually moves toward the address pits 206 as shown by a broken line. However, since the sector address area 203 is short, the tracking control is performed so that the light spot 210 becomes the data area 205 which is a groove before completely following the address pit 206, and 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. This RF signal amplitude Aadr is equal to the light spot 210 and the address pit 206.
It changes depending on the distance. In other words, Aad
r becomes smaller, and Aadr becomes larger as it approaches.

[0014]

However, FIG.
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.

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

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

The present invention has been made in view of the above problems, and by improving the arrangement of address pits in a sector address portion, it is possible to reduce defective reading of an address signal due to track deviation and to reduce track deviation after passing a sector address. It is another object of the present invention to provide an optical disc capable of identifying tracks of lands and grooves and an optical disc recording / reproducing apparatus using the same.

[0018]

The optical disk of the present invention comprises:
An optical disc having an adjacent spiral first track and a spiral second track, and recording or reproducing information on or from the first and second tracks. A first address block formed so as to straddle both the second track adjacent on the inner circumference side of the first track, and an adjacent address block formed on the outer circumference side of the first track; And a second address block formed so as to extend over both the second track and the second track.

In one embodiment, there is provided a land / groove recording / reproducing optical disk having a plurality of sectors each 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;
Each of the plurality of address blocks has a portion indicating an address number for identifying the plurality of sectors and a portion indicating an ID number for identifying the plurality of address blocks within the sector address area. I have.

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

In one embodiment, the portion indicating the address number has a data pattern common to the plurality of address blocks in the same sector address area.

[0022] 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 the disk rotation accuracy in a laser cutting process for manufacturing a disk master.

In one embodiment, of the plurality of address blocks, the first 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 has a radius from the center of the track to an inner side or an outer side. It is formed at a position shifted by about half the track pitch along the direction.

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

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 type optical disk provided with a plurality of sectors having a sector address area and a data area. Has a plurality of address blocks, and at least two address blocks adjacent in the circumferential direction among the plurality of address blocks are:
Each of the plurality of address blocks is formed at a position shifted to the opposite side with respect to the track center, and each of the plurality of address blocks includes a portion indicating an address number for identifying the plurality of sectors, and a portion within the sector address area. A portion indicating an ID number for identifying a plurality of address blocks,
The recording / reproducing apparatus irradiates a light beam on the optical disk, receives reflected light from the optical disk, and outputs a reproduction signal. The optical head reproduces the sector address of the optical disk. And an address signal reproducing unit for reading the ID number and the ID number.

In one embodiment, the apparatus further comprises an address correction unit for correcting the address number read for each address block according to the ID number using a signal indicating whether the data is land reproduction or 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; And a comparator for comparing two or more address numbers respectively associated with the ID numbers of the two, and detecting whether or not the two or more address numbers coincide with each other, and reproducing light based on an output of the comparator. A determination unit configured to determine whether a track being irradiated with the beam is a land track or a groove track.

Preferably, 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 detecting section for detecting a tracking error signal indicating a positional deviation amount between a track and a light spot, and a timing generator for generating a gate pulse signal synchronized with each address block in the sector address area. Unit, an outer-peripheral value sample-and-hold unit that samples and holds the level of the tracking error signal for an address block disposed on the outer peripheral side in synchronization with the gate pulse signal, and the tracking for an address block disposed on the inner peripheral side. An inner value sample and hold unit for sampling and holding the level of the error signal; a differential circuit for calculating a difference between the outer value sample and hold unit and the inner value sample and hold unit; and an output of the differential circuit A gain conversion unit for converting the signal into a signal having a predetermined level; Using the output from the emission calculating unit further includes a tracking offset correction circuit for performing a tracking correction.

In one embodiment, a reflected light amount signal detecting section for detecting a reflected light amount from the optical disk, a timing generating section for generating a gate pulse signal synchronized with each address block of the sector address, Outer peripheral value sample and hold section that samples and holds the reflected light amount signal level for the address block arranged on the outer peripheral side synchronously, and inner peripheral value that samples and holds the reflected light amount signal level for the address block disposed on the inner peripheral side A sample and hold unit, a differential circuit for calculating a difference between a value held by the outer value sample and hold unit and a value held by the inner value sample and hold unit, Tracking conversion using the output from the gain conversion unit and the gain calculation unit Additionally and a tracking offset correction circuit for performing.

Still another optical disk of the present invention has an adjacent spiral first track and a spiral second track, and information is recorded and reproduced on the first and second tracks. An optical disc, wherein an address block is formed so as to extend over both the first track and the second track, and is formed on one of the first and second tracks. A track identification mark.

In one embodiment, the address area is:
They are arranged according to CAV format or ZCAV (ZCLV) format.

Still another optical disk of the present invention has an adjacent spiral first track and a spiral second track, and information is recorded or reproduced on the first and second tracks. Optical disc,
Address blocks formed so as to straddle both the first track and the second track, and both the first track and the second track adjacent on the inner peripheral side of the first track. A first track identification mark that spans,
An address area having 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, the first track identification mark And the second track identification mark are the same.

Still another optical disk according to the present invention has a first spiral track and a second spiral track, and information is recorded or reproduced on the first and second tracks. Optical disc,
An address block formed so as to extend over both the first track and the second track, and a track identification mark provided in a control information area of one of the first track and the second track And an address area having the following.

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 selects a first track or a second track on which information is to be recorded or reproduced. A track specifying means for reading the track identification mark; and a track identification mark reproducing means for reading the track identification mark. The track identification mark reproducing means reads the track identification mark of the track being reproduced, and determines whether or not the track identification mark exists. Identifying whether the track being reproduced is the first track or the second track and outputting a track identification signal, and the track designating means, in response to the track identification signal, Switching between selection of one track and the second track.

The optical disk recording / reproducing device is an optical disk recording / reproducing device capable of recording / reproducing information from / to the optical disk of the present invention, and comprises a first track or a second track for recording / reproducing information. A track designating means for selecting the first and second address blocks for reading the first and second address blocks over both the first track and the second track adjacent to the first track; Track identification means for identifying which of the first track and the second track the track being reproduced is based on the first and second address blocks reproduced by the address reproduction means. The track identifying means determines that the track being reproduced is different from the two addresses reproduced by the address reproducing means. The first track and the second track are 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 disk recording / reproducing apparatus is an optical disk recording / reproducing apparatus capable of recording / reproducing information from / to the optical disk of the present invention, and selects the first or second track for recording / reproducing information. A track specifying means for reading, a track identification mark reproducing means for reading a track identification mark over both the first track and the second track adjacent to the first track, and a track identification mark reproducing means for reproducing the track identification mark. Track identification means for identifying which of the first track and the second track the track being reproduced is based on the two track identification marks, the track identification means comprising: Due to the difference between the two track identification marks reproduced by the identification mark reproducing means, the track being reproduced is A track identification signal is output by identifying whether the track is the first track or the second track, and the track designating means selects the first track and the second track based on the track identification signal. An optical disc recording / reproducing apparatus characterized by switching.

An optical disc recording / reproducing apparatus capable of recording / reproducing information from / to the optical disc of the present invention,
Track specifying 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 in an information area, and a track for determining the polarity of the reproduced track A polarity discriminating means, and a track selecting signal correcting means for correcting a track selecting signal of the track specifying means, wherein at the start of reproduction of the optical disc, the data reproducing means reproduces the track identification mark in a control information area; The track polarity discriminating means discriminates whether or not the selection of the track is correct from the track identification mark of the reproduced track and the track selection signal of the track designating means, and outputs a track polarity discrimination signal. The track selection signal of the track designating means based on a discrimination signal It corrected, selecting the first track and the second track.

In one embodiment, the method of identifying a track on an optical disk includes reading a plurality of address blocks provided in one address area, and detecting a match or mismatch between at least two address blocks to reproduce the track. It identifies whether the current track is the first track or the second track.

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

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

Further, an off-track signal indicating the actual track shift amount between the light spot and the track is detected 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. By using the off-track signal to correct the tracking error signal, accurate track following becomes possible.

[0046]

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

(Embodiment 1) FIG. 1 is an external view of a first embodiment of an optical disk 401 according to the present invention. The optical disk 401 is provided with two spiral tracks 404, a convex track 402 (land track) and a concave track 403 (groove track).

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 disk 401 has 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 a type optical disk 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.
a, 402a, 403b and 402b,
An address area 405 indicating the address of each track (or sector) is allocated.

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. Groove track 403b
A pair of address blocks 411b and 801b composed of the same pit string are provided to indicate the address.
To indicate the address of the groove track 403c, a pair of address blocks 411c composed of the same pit row
And 801c. 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 apparent 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 the shift is about half of the track pitch Tp. In the case of this embodiment, the track pitch Tp is about 0.3 to 1.6 μ.
m.

More specifically, the address block 411b
Are the groove track 403b and the groove track 40
It is formed so as to straddle both the groove track 403b and the land track 402b around the boundary 409 between the land track 402b and the adjacent land track 402b on the outer peripheral side of 3b. Further, the address block 801b is formed so as to extend over both the groove track 403b and the land track 402a around the boundary 407 between the groove track 403b and the land track 402a adjacent on the inner peripheral side of the groove track 403b. In other words, the two address blocks 411b and 801b are respectively moved from the center 408 of the groove track 403b by approximately 1
It is formed to be shifted in the outer and inner circumferential directions by / 2 Tp. 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 track 403b include the same address information. 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 adopting 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.
After passing over both of the tracks 01b, it moves along the track center 408 of the track 403b in the right part of FIG.

The address area 40 of the optical disk shown in FIG.
5 is formed according to CAV or ZCAV (ZCLV) format. Therefore, the address areas 405 of adjacent tracks are aligned in the radial direction of the disk.
As a result, the address area 4 on the land track 402b
05 has adjacent groove tracks 403b and 403.
Two address blocks 411b and 801 corresponding to c
c is 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, two address blocks (411b and 801b) having the same value are stored in the address area 405.
When the information of b) is reproduced and the data of the land track 402b is reproduced, information of two different address blocks (411b and 801c) in the address area 405 is reproduced. These tracks share the same address block 411b, but the address block 41
Address block 801b reproduced following 1b
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 composed of the groove track 403b and the groove track 403.
A second address block is provided on a boundary line 409 between land tracks 402b adjacent on the outer peripheral side of the groove track b, and on a boundary line 407 between the land tracks 402a adjacent on the inner peripheral side of the groove track 403b and the groove track 403b. However, the first address block is composed of the groove track 403b and the groove track 4
A disc in which a second address block is provided on a boundary 407 between land tracks 402a adjacent on the inner peripheral side of the track 03b and a land track 402b adjacent on the outer peripheral side of the groove track 403b and the groove track 403b. Has the same effect.

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

FIG. 3 is a block 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 focusing on reproduction of information recorded on an optical disk, but it is needless to say that the present invention is applicable to recording information on an optical disk. For the sake of simplicity, in the specification of the present application, "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
It is suitable for recording or reproducing information on or from the optical disc 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 disk 401 into a voltage and amplifies the voltage into a signal of a predetermined level. The binarization circuit 605 converts the reproduced analog signal into a digital signal. The linear motor 609 is for moving the optical head 610 to a target track at a high speed, and includes a linear motor control circuit 607.
Controls its operation. 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 reproducing circuit 602 includes a binarizing circuit 605
Address reproducing circuit 603 for reproducing an address (address information) from the signal digitized by the above, 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 an address reproducing circuit 603.
Address and track identification circuit 9 reproduced by
A register 902 is provided to combine the track identification signal b obtained from the address 01 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. To access the desired track,
The CPU 601 uses the linear motor control circuit 607 to move the optical head 610 to the vicinity of the target track, and further uses the tracking control circuit 608 to move to the target track by a track jump. Select a groove track.

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

The address reproducing operation by the optical disk recording / reproducing apparatus shown in FIG. 3 will be described below with reference to FIGS.

When the logical address of the track on which data is to be recorded or reproduced is given, the CPU 601 issues a seek command to the linear motor control circuit 607, drives the linear motor 609, and moves the optical head 6 near the target track.
Move 10 Next, the CPU 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 to thereby control the optical head 6.
10 reaches the destination track. The focus tracking control circuit 608 switches the polarity of tracking control when a track selection command is given to switch the optical head 610.
To jump a half track to focus and track the target track.

The reflected light from the optical disk 401 is converted into a current by a plurality of photodetectors of the optical head 610, and is converted into a voltage by the head amplifier circuit 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 supplied 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, the logical address for identifying the data area is the land track 4
02, and an address block 411 (reproduced by the address reproducing circuit 603) common to the groove track 403 and a track identification signal b (1 bit) for identifying the land track 402 and the groove track 403.
The most significant one 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 comprises two registers 1001 and 1002, a comparator 1003, a flip-flop 1004, and delay elements 1005, 1006 and 1007. The track identification circuit 901 uses a gate pulse signal obtained by delaying the address detection signal
The two addresses e are taken into the registers 1001 and 1002, and the two addresses e are compared by the comparator 1003. That is, the address detection signal d is output from the three delay elements 100
5, 1006 and 1007 are converted into gate pulse signals for the registers 1001 and 1002 and the flip-flop 1004 by being delayed for a predetermined time. With this circuit, when two address blocks 411 and 801 match, a track identification signal b indicating a groove track is generated, and when two addresses are different, an identification signal b indicating a land track is generated. .

The 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, reproduces data 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 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 state, the tracking polarity is switched by inverting the track selection signal.

The optical disk 40 shown in FIG.
When reproducing the data of one groove track, the laser beam scans substantially the center 408 of the groove track and
In one address area, information of two address blocks having the same value (for example, 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 reproduces two different address blocks (for example, 411b and 801c) in one address area. 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 and 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 only from the reproduction signal based on the difference between the two addresses. Common 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 disk according to the present invention.

According to a predetermined physical format, a plurality of sectors 4 are continuously arranged on the disk 1 along the track 2. Each sector 4 has 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 this 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:
These are described as ID1 to ID4, respectively. Each address block is VFO11, AM (address mark)
12, a sector address number 13, a duplication order number (ID number) 14, and a CRC (Cyclic Redundancy Check) 15.

The VFO 11 is a reproduction clock synchronizing signal section having a continuous repetitive data pattern for ensuring that an address signal can be reproduced from the address area even if the rotational speed of the disk fluctuates. The recording / reproducing apparatus adds a PLL (Phase Lo
cked Loop) and generates a data read clock. The AM 12 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 the address number and the ID number. 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 disk of this embodiment. In the above 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 not limited to four.

In FIG. 7A, the land track 22 and
The adjacent groove tracks 21 and 23 are shown. In the sector address area 5 provided between the data areas 6 and 7, four address blocks ID1 to I
D4 is arranged so as to wobble alternately with respect to the center of the track. More specifically, assuming that 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 from the track center by Tp / 2 in the radial direction. , And are alternately arranged on the inner peripheral side and the outer peripheral side. 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 this embodiment is formed on the recording film.

Usually, the address pits 25 are formed when the groove tracks 21 and 23 are formed. When the groove track and the address pit are formed by the laser cutting method, the laser light spot for cutting moves to the right in FIG. 7A while forming the groove track 21 of the data area 6. Thereafter, the laser beam spot moves rightward in FIG. 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 beam is shifted by 1/2 Tp in the radial direction from the groove track. The laser light is emitted intermittently according to the address pit to be formed. FIG. 7 (a)
In FIG. 7, the address blocks ID1 and ID3 are provided at positions shifted upward in FIG. 7A from the address blocks ID2 and ID4.
The address blocks ID1 and ID3 may be provided at positions shifted downward in the drawing from the address blocks ID2 and 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 pit 25. Therefore, when the light spot 24 is located 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 pits 25 is different between and, the irradiating area is almost the same.
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 also in the sector address area 5 formed of pits. Similarly, a value proportional to the amount of displacement between the light spot 24 and the address pit 25 (the output of the TE signal for the same amount of displacement 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.

FIGS. 8A and 8B are views showing the state of the RF signal in the sector address area when the 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. . In FIG. 8A, the light spot 24 is used for the ID1 and ID3 portions.
Pass near address blocks 16 and 18 so that R
The F signal amplitude increases, and in the ID2 and ID4 portions, the light spot 24 passes away from the address blocks 17 and 19, so that the RF signal decreases. Therefore, ID2, I
In D4, it becomes difficult to read the address signal. But,
It suffices if at least one address block can be normally read per one sector address. In the example of FIG. 8A, ID1, I
Since D3 has a large RF signal amplitude and the address is easy to read, it can be read as a sector address.

On the other hand, in the case of FIG.
In D3, the RF signal amplitude becomes smaller and the address reading becomes worse, but in ID2 and ID4, the RF signal amplitude becomes larger 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 TE signal is
A level shift is generated alternately 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. Therefore, the light spot does not react to the level shift of the TE signal. Further, 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, the case of four address blocks per sector address has been described. However, if two or more address blocks are used, a similar effect can be obtained for improving the address reading capability with respect to track deviation. .

When even 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 is generated 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 influence. 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 3) Next, a third embodiment of the optical disk according to the present invention will be described.

FIGS. 9A and 9B show the arrangement of information blocks in the sector address area in this embodiment.
In the optical disc of the present embodiment, additional information blocks 107, 108 and 109 including additional information other than address number information are provided in the sector address area 5. Others have the same configuration as the configuration shown in FIG. Here, # 100 and # 101 indicate track address numbers.

Each of the address blocks 16 to 19 contains 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 center of the track in the radial direction by a width of approximately Tp / 2. If the additional information block is shorter than the address block, or if the additional information cannot be divided into two, the additional information block shown in FIG.
As described above, the additional information block 107 is arranged on either the inner circumference side or the outer circumference side of the track. On the other hand, when the additional information block is relatively long, FIG.
, A block unit 108 capable of identifying additional information,
109, and the tracks may be alternately shifted on the inner and outer circumferential sides of the track.

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 for the track deviation between the address information and the additional information can be improved and the sector address area can be improved. The stability of tracking control immediately after passing through the middle and sector address areas can be improved.

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

(Embodiment 4) Next, a fourth embodiment of the optical disk according to the present invention will be described.

FIGS. 10A and 10B show the arrangement of address blocks in the sector address area in this embodiment. 10A and 10B, 110 and 112 are groove tracks, 111 is a land track, 113 and 1
14, 115, 116, 117, 118, 119, 12
0 is an address block, 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, it becomes one continuous groove, and this portion becomes a track (a groove track in this embodiment), and the laser beam is intermittently turned on for a specified time.
Pits are formed by irradiating at / OFF.
That is, in the case of a disk having a sector address, the laser beam for cutting is moved around the entire circumference of the disk by controlling the irradiation of the laser beam in the grooves and the address pits while moving the cutting laser light in the radial direction by the track pitch in one rotation of the master disk. An address pit is formed. Tracks and address pits are formed by the same method in the wobbled address pits of 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 radially arranged for each address block. T
Turn on cutting laser light by shifting by p / 2
/ OFF. 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, a groove track 110 (left side in the figure) and address blocks 113, 114, 115 and 116 are formed in this order. Then, 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 rotational accuracy of the disc master varies, the same ID
The circumferential positions of the address blocks (for example, the address blocks 113 and 117) including the numbers do not always match. As shown in FIG. 10A, if the data is shifted by ΔX, when the data of the land track 111 is reproduced, the end of the address block 117 and the address block 11
Since the top of 4 overlaps by ΔX, the reproduced signal (RF) signal may not be detected accurately. Therefore, FIG.
By arranging the circumferential position of each address block with an interval Xm greater than the disk rotation accuracy at the time of cutting, as in 0B, overlapping of adjacent address blocks can be prevented, and reproduction of address signals can be more reliably performed. become.

The interval Xm which is equal to or higher than the disk rotation accuracy at the time of cutting is set, for example, to a value within the range of 0 to 1.0 μm. The 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 is a diagram showing the arrangement of address pits in the sector address area on the optical disk of this embodiment. 11, 150 and 152 are groove tracks, 151 is a land track, 153, 154 and 15
5, 156 are address blocks, and 157 to 164 are address pits constituting the address blocks. 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.
The interval on the time axis between the address pits of the address blocks 153 and 154 when reproducing data from the data block 50 is the information read clock cycle Tw (for example, about 5 to 1).
00 nanoseconds). 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 the fourth embodiment, the position of the address block for the next groove track 152 is set in the circumferential direction in order to prevent address blocks from overlapping due to rotation fluctuation during cutting. It is provided shifted. Also in this case, when the land track 151 is reproduced with ΔX set to a free length, the pit 163 of the address block 155 is shifted to the address block 15.
The time interval T14 of the fourth pit 160 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, the VFO at the head of the address block 154
Therefore, it takes time to adjust the phase of the data read clock in the PLL again.

In order to solve such a problem, a shift ΔX
Of the address pits may be arranged such that the time interval T12 is substantially an integral multiple of Tw. In this case, T14 is also substantially an integral multiple of Tw, and the PL in the address block 154 at the time of data reproduction of the land track 151 is obtained.
The time required until L is synchronized can be reduced.

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

FIG. 12 shows the arrangement of address blocks in the sector address area on the optical disk of this embodiment. In FIG. 12, 130 and 132 are groove tracks, 131 is a land track, 133, 134 and 13
5, 136, 137, 138, 139 and 140 are address blocks, and 24 is a light spot. 141 is VF
O, 142 is AM, 143 is the address number, 144 is I
D number 145 is a CRC, 146 and 147 are dummy data areas.

In this embodiment, as shown in FIG. 12, at the beginning and end of each address block, a dummy data area 146, 1
47 are arranged. Here, VFO141, AM14
2, address number 143, ID number 144, CRC14
5 is as described in the second embodiment. Dummy data area 1
The provision of 46 and 147 prevents the head of the address block from overlapping the end of the previous address block even if the position of the address block changes in the circumferential direction.

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,
There is an advantage that the FO area becomes apparently longer, and the accuracy of generating the data read clock is increased. Dummy data area 1
The lengths of 46 and 147 need only be such that the dummy data area does not overlap the range actually required 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 disk recording / reproducing apparatus capable of reading the sector address of the optical disk shown in FIG. 7 (a). In FIG. 13, 31
Is a disk, 32 is a disk motor, 33 is an optical head,
Numeral 34 denotes an address reproducing unit, an adding circuit 35, and a waveform equalizing unit 3.
6, data slicer 37, PLL 38, demodulator 39,
It comprises an AM detection section 40, a switch 41, and a CRC determination section 42. 43 is an error correction unit, and 44 is an address correction unit.

FIG. 14 shows a configuration of a sector address of an optical disk on which information is recorded / reproduced by the present optical disk recording / reproducing apparatus. This optical disk is shown in FIG.
Has the same configuration as that of the optical disc. In FIG.
A land track 52 and groove tracks 51 and 53 adjacent thereto 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, assuming that the track number is counted up by one in one round of the track, the groove track 51 is located at address # 100,
It is assumed that the land track 52 is at address # 101 and the groove track 53 is at address # 101. The numerical value (# 100 or the like) in each address block represents the value (address) set to the address number 13 in the address block.

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

First, the optical head 33 irradiates the optical disk 31 with a laser beam, and detects the intensity of the light reflected by the optical disk 31. Reproduction signal (RF signal) from reflected light amount
Generate Waveform equalizer 36, data slicer 37,
PLL 38, demodulator 39, AM detector 40, switch 4
1 and the operation of extracting an address number and an ID number from an RF signal for each address block through the CRC determination unit 42 are the same as the operations described in the conventional example.

The light spot 24 has a groove track 51
When reproducing the data of (# 1), the address signals obtained in the sector address area are (# 100, 1), (# 100, 2), (# 1) in the order of (address number, ID number).
00, 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 when reproducing data on a groove track and when reproducing data on a land track. The address blocks 54, 55, 56, and 57 containing the same address number are wobbled on the inner and outer circumferences with respect to the center of the groove track 51, and are obtained when the data of the groove track 51 is reproduced. The address numbers of ID1 to ID4 all have the same value (here, # 100). 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, the light spot 24 is
When reproducing the data of No. 2, the address signals obtained in the sector address area are (# 101, 1), (# 100,
2), (# 101, 3) and (# 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
2 and 1 in the address number # 100 read from ID4
To obtain an address number # 101. ID1 and ID3
Since the address number # 101 read out in step 2 matches the actual address value, the address number is used as it is. Then, the final address value # 101 is output. The address correction can be achieved by inputting a signal (L / G signal) indicating whether groove reproduction or land reproduction is performed to the address correction unit 44.

As described above, in the optical disk recording / reproducing apparatus of this embodiment, if it is known in advance whether the groove is to be reproduced or the land is to be reproduced, the read address numbers (for example, # 100) are read almost simultaneously. An address correction unit 44 is provided which can correct based on the read ID number (for example, 2) and obtain a correct sector address value (for example, # 101). As a result, it becomes possible to manage the sector address of the optical disk having the arrangement 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 four addresses ID1 to ID4 are normally read. Therefore, when the value of ID1 is normally obtained, it is preferable to use the value as it is as the track address. In other words, the track address of the land track 52 may be set to # 100. However, setting the track address to # 101 is more practical because it is not necessary to correct the address number read from ID1. Also, when the VFO of ID1 is provided slightly longer than the other address blocks, thereby increasing the read accuracy of ID1, the read accuracy of the read land and groove is equal when ID1 directly indicates the track address number. There are also advantages.

In the above embodiment, a case where one sector is included in one track has been described. However, if the number of sectors included in one track is N and the disk has a format in which the sector address numbers are sequentially increased, the address address adjacent to address address # 100 is (# 10
0 + N). For this reason, the address correction unit sets the read address value to N when reproducing the land track.
, The address value can be obtained in the land track and the groove track in the same manner as described above.

Further, even when the number of sectors included in one track is N and the numerical value changes discontinuously in the address number, the format of the sector address is changed from the address number and the sector number read for each address block. It is sufficient to calculate a correction value according to this.

Further, here, a case where the same address number can be read when reproducing data on a groove track has been described. However, 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 numbers are arranged on the inner and outer circumferences of one track, they are not necessarily arranged in one track, but are read based on the ID numbers if the arrangement pattern of the ID numbers and the address blocks is known. It is possible to correct the issued address 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 disk recording / reproducing apparatus of this embodiment. In FIG. 16, 31
Is a disk, 32 is a disk motor, 33 is an optical head,
Numeral 34 denotes an address reproducing unit, an adding circuit 35, and a waveform equalizing unit 3.
6, data slicer 37, PLL 38, demodulator 39,
It comprises an AM detection section 40, a switch 41, and a CRC determination section 42. Reference numeral 43 denotes an error correction unit, and reference numeral 61 denotes a land / groove identification unit.

FIG. 17A shows a land / groove identifying section 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, and 69 is a comparator. Reference numerals 4 and 70 are determination units.

An operation of identifying a land / groove from an address signal in a sector address area where address blocks are arranged as shown in FIG. 10 using the above-described optical disk recording / reproducing apparatus will be described. First, the optical head 33
Irradiates the disk 31 with a laser beam and detects a reproduction signal (RF signal) from the amount of reflected light. RF signal to waveform equivalent part 3
6, data slicer 37, PLL 38, demodulator 39,
The operation of extracting an address number and an ID number for each address block through the AM detection unit 40, the switch 41, and the CRC determination unit 42 is the same as the operation described in the conventional example.

The address signal read by the light spot 24 scanning the sector address area 5 is:
(Address number, ID number) are sequentially input to the land / groove identification unit 61 as a set. In the land / groove identifying section 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 ID number 1 is stored in the memory 1 (62), and the ID number is stored in the memory 2 (63).
It is stored like the address number of D number 2.

Referring to FIG. 14, when the data of the groove track 51 is reproduced, # 1 is stored in the memory 1.
00, # 100 in the memory 2, # 100 in the memory 3, and # 100 in the memory 4. Comparator 1 of FIG. 17A
At (66), by comparing the two address numbers of the memory 1 (62) and 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, the comparator 2 (67) compares the comparison between the memory 2 (63) and the memory 3 (64) with the comparator 3 (64).
At (68), the memory 3 (64) and the memory 4 (65) are compared, and at the comparator 4 (69), the memory 4 (65) and the memory 1 (62) are compared and passed to the determination unit 70.

In this example, from the arrangement pattern of the address blocks as 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 currently reproduced track is a groove track. On the other hand, when the light spot 24 reproduces the land track 52 of FIG. 14, # 101 is assigned to the memory 1 (62), # 100 is assigned to the memory 2 (63), and
# 64 is stored in (64), and # 100 is stored in the memory 4 (65). As a result, the outputs of the comparators 1 to 4 all become "mismatch". Thus, in the land track,
From the arrangement pattern of the address blocks as shown in FIG.
All the results of comparators 1-4 should be "mismatched". 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 or not 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) and the comparator 2 (6)
7) If at least one of the results of the comparator 3 (68) and the comparator 4 (69) is “match”, the track currently being reproduced is a groove track, and at least one result is “mismatch”. If so, it can be determined that the track is a land track. That is, it is not necessary to read all the address blocks accurately, and the inner address block ID1 or ID3
If the information in at least one of the above and the information in at least one of the outer peripheral side address blocks ID2 or ID4 can be read out as an address signal, it is possible to identify a land or a groove.

Further, as shown in FIG.
Even if 1 is added, it is possible to determine whether the track being reproduced is a land or a groove. In this case, at the time of land reproduction, the memory 1 (62) has # 101 and the memory 2 (63)
# 100 in memory 3 (64) # 101 in memory 3
Since # 100 is input to (65), the outputs of the comparators 1 to 4 are "matched" at the time of land track reproduction, and when the outputs of all comparators are "matched", Should be determined. 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 that case, the determination unit 7
A signal indicating that identification is not possible with 0 (L / G OK signal) may be output. 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. Extremely few lands with practically no problems due to the above operation,
Groove identification is possible.

In addition, when an address address that is accidentally determined to be normal by the CRC determination unit despite being actually an incorrect address address is input to the land / groove identification unit, the output of the comparator is output. It is divided into "match" and "mismatch". Also in this case, the determination unit 70 may output a signal (L / G OK signal) indicating that identification is impossible.

Further, the land / groove identifying section 61
The land / groove identification signal (L / G signal) of FIG.
It is needless to say that if the configuration is such that the address is inputted to the address correction section 44 of the embodiment (Embodiment 7), land / groove identification and address value output can be performed simultaneously from one sector address.

(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 apparatus 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, 8
Reference numeral 1 denotes a tracking error signal detection unit, which is a differential circuit 82, L
It is composed of a PF (Low Pass Filter) 83. 84 is a phase compensator, and 85 is a head driver. Reference numeral 90 denotes a timing generation unit, 91 denotes an outer peripheral value sample / hold unit, 92 denotes an inner peripheral value sample / hold unit, 93 denotes an addition circuit, and 94 denotes a gain conversion unit.

An operation for detecting a deviation amount (off-track amount) between a light spot and a track in a sector address area in which address blocks are arranged as shown in FIG. 14 using the above-described optical disk recording / reproducing apparatus will be described.

First, the optical head 33 shown in FIG.
1 is irradiated with laser light, and a reproduction signal (RF signal) is detected 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, it is assumed that the TE signal has a negative value when the light spot 24 passes on the outer peripheral side of the address pit 25 and has a positive value when it passes on the inner peripheral side. Light spot 2
If track 4 passes line (a) of track 2, ID1
And ID3, since the distance between the light spot 24 and the address pit 25 is relatively short, the level fluctuations VTE1 and VTE
TE3 is a small value in the negative direction. Also, in this case, the ID
2 and ID4, the distance between the light spot 24 and the address pit 25 is large, so that the TE signal level changes VTE2 and VTE4
Increases and becomes a positive value. Therefore, FIG.
A TE signal as shown in FIG. When the light spot 24 passes through the line (b) of the track 2, the distance between the light spot 24 and each of the address pits 25 of ID1 to ID4 is equal, so that the level fluctuation amount becomes the same in all of ID1 to ID4. Therefore, a TE signal as shown in FIG. 19B is obtained. When the light spot 24 passes through the track 2 line (c), a TE signal as shown in FIG. 19C is obtained. As can be seen from FIG. 19, since the magnitude of VTE1 (or VTE3) and VTE2 (or VTE4) changes depending on which position of the track 2 the light spot 24 passes, the off-track amount is estimated from the difference between these changes. can do. That is, the equation Voftr = V
The amount of off-track is obtained by TE1-VTE2. If the light spot 24 passes through the center line (b) of the track 2,
In the sector address area 5, VTE1−VTE2 = 0, VTE1−VTE2 <0 when passing through the track 2 line (a), VTE1−VTE2> 0 when passing through the track 2 line (c), and the direction of the off-track amount. And the size can be determined.

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 generation section 90 from the address reproduction section 34, the gate pulse signal G synchronized with the outer peripheral address block is generated based on the input address signal.
T1 and a gate pulse signal GT2 synchronized with the inner peripheral address block are generated. This gate pulse signal G
T1 is a signal for sampling the signal of the outer peripheral value sample and hold unit, and the gate pulse signal GT2 is a signal for sampling the signal of the inner peripheral value sample and hold unit.

First, FIG. 20A shows a case where ID1 can be read. If ID1 can be read, ID2, ID
3. Since the timing at which ID4 appears can be known,
A signal GT0 including a gate pulse synchronized with the end of D1 is generated. In this case, the inner address block ID3 and the outer address block ID2 (ID2 is I
D4) (which may be D4).
1 is generated. Therefore, the timing generator 90 generates the gate pulse signal GT1 at a timing delayed by the time T1 from the gate pulse signal GT0, and generates the gate pulse signal GT2 at a timing delayed by the time T2 from the gate pulse signal GT0.

FIG. 20B shows a timing chart in the case where ID1 cannot be read but ID2 can be read.
A gate pulse signal GT0 synchronized with the end of ID2 is generated. In this case, each of the inner peripheral address blocks I
Since it is necessary to generate the gate pulse signal GT2 and the gate pulse signal GT1 for D3 and the outer address block ID4, the timing generator 90 generates the gate pulse signal GT1 at a timing delayed by the time T2 from the gate pulse signal GT0. Then, the gate pulse signal GT2 is generated at a timing delayed by the time T1.

FIG. 20 (c) 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. Assuming that GT0 is another gate pulse signal and a signal that rises immediately before the sector address area, the timing generator 90 generates gate pulse signals GT2 and GT1 for the inner address block ID1 and the outer address block ID2. Generates GT1 at a timing delayed by time T4 from GT0, and generates a gate pulse signal G
GT2 is generated at a timing delayed by time T3 from T0.

Using the gate pulse signals GT1 and GT2 generated by the timing generator 90, the TE signal level VTE2 in the outer peripheral address block ID2 is synchronized with the gate pulse signal GT1 in the example of FIG. The TE signal level VTE3 in the inner address block ID3 is stored in the outer value sample / hold unit 91, and the inner signal sample / hold unit 9 is synchronized with the gate pulse signal GT2.
2 is stored. As a result, (VTE
1-VTE2) is output. Since this value corresponds to the off-track amount, it is further adjusted to the level of the TE signal by the gain conversion unit 94, and the off-track signal (OF
TR signal). In an actual tracking control system, even if the TE signal is controlled to be 0,
A tracking error signal detector 81, a phase compensator 84,
Due to the offset or the like generated in the head driving unit 85, a state where the light spot is not actually at the center of the track occurs.
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.
The same applies to cases (b) and (c).

A gate pulse signal GT2 synchronized with one of the inner address blocks and a gate pulse signal GT1 synchronized with one of the outer address blocks may be generated and fixed to a specific address block. It is not something to be done. It is not necessary to manage the time T1 and the time T2 at precise time intervals that synchronize 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).

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 number of outer address blocks are obtained. If the off-track signal is detected by using the average value of, 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 apparatus of this embodiment. 21, 31 is a disk, 32 is a disk motor, 33 is an optical head, 34 is an address reproducing unit, 8
1 is a tracking error signal detection unit, 84 is a phase compensation unit, and 85 is a head drive unit. Reference numeral 90 denotes a timing generator, 91 denotes an outer value sample-and-hold unit, 92 denotes an inner value sample-and-hold unit, 93 denotes a differential circuit, and 94 denotes 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, 8
1, 84, 85, 90, 91, 92, 93. Example 9
The same operation as the operation described above is performed. In the ninth embodiment, the TE signal is sampled and held to detect the off-track amount. The difference is that the amount is detected.

In the reflected light amount detecting section 100, the optical head 33
Are added by an adder circuit 101, and the added signal is added to an LPF 102 (band is higher than the tracking control band but lower than the RF signal, about several tens to several hundreds KHz).
And removes high-frequency components to detect an AS signal as a signal representing an average amount of reflected light.

FIG. 22 is a diagram showing a change in the AS signal with respect to the amount of deviation between the light spot and the track. As described in the second embodiment, the RF signal changes as shown in FIGS. 7B, 8A, and 8B depending on the position where the light spot 24 passes. 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.
AS signals as shown in (b) and (c) are 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 gate pulse signals GT1 and G to be sampled and held
The generation of T2 is performed by the timing generator 90 as described in the ninth embodiment. However, the timing at which the gate pulse signal is generated can be detected more accurately by sampling the AS signal at the same pit pattern in each address block. Therefore, the VFO section, the AM section, or the specially provided pit section It is preferred to use the AS signal at

As in 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 level of the envelope below the RF signal (the side where the amount of reflected light is small) (VRF3 and VR in FIG. 22).
The same applies when F4) is used.

(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 the sector address area on the optical disk of this embodiment is shown in FIG.
A is the same as that shown in FIG. However, as shown in FIG. 23, in the optical disc of the present embodiment, instead of placing an interval (ΔX1) between adjacent address blocks, the last pattern of each address block is prevented from being a pit.
In addition, a data arrangement is adopted so that the head pattern of the next address 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 master disc is arranged.

As shown in FIG. 10B, when the address blocks are arranged shifted in the circumferential direction, the space between the address blocks becomes useless. However, according to the optical disk of this embodiment, such a problem is solved. Does not occur.

With reference to FIGS. 24A, 24B, 25A and 25B, advantages of the optical disk of this embodiment will be described in detail. In the data arrangement of the address block shown in FIGS. 24A and 24B, the last pattern of the address block is a pit, and the leading pattern of the next address block is also a pit. Specifically, FIG. 24A shows a pit shape expected from a 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 formed to have a specified length along the center line of each address block. However, in reality, in the cutting process of the master disc, when the address pit is formed while displacing the position of the laser beam spot in the sector address area 5 in the radial direction, the last pit of the address block 113 and the address block 114 are formed.
Are formed continuously as shown in FIG. 24B. 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, as shown in FIG. 24B, 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 by different laser light beams, but the use of this method complicates the cutting apparatus.

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.
A indicates a sector address area in a case where the pit arrangement at the connection between the address blocks is not particularly defined.
In the sector address area of FIG. 25A, adjacent address blocks 114 and 117 overlap in the circumferential direction by a length corresponding to the cutting accuracy ΔX, and the top of the address block 114 is pit data. . In this case, as shown in FIG. 25A,
When the head pit data of the address block 114 overlaps the non-pit data at the end of the address block 117, the light spot 24 is moved to the land track 1
When the data of the address block 117 is reproduced while moving along the center line of the address block 11,
7 causes a data error. This is the address block 11
The first pit data of address block 4 makes address block 1
This is because it is erroneously determined that the end of 17 has pit data.

FIG. 25B shows a sector address area on the optical disk 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 non-pit data. Because
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 head of the address block is a VFO area, and it is not always necessary to read all the data. Resynchronize data section, address number, CR
If C can be correctly recognized, no problem occurs in the operation of reading the address block.

Therefore, as shown in FIG. 25B, by setting the start pattern and the end pattern of each sector address block to be non-pit data, it is possible to divide wobble and arrange the address blocks between the address blocks at the time of cutting the disk master. In addition to preventing pit formation defects and address data reading errors due to address block overlap during sector address reproduction, useless gaps can be reduced.

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

FIG. 26A is a layout diagram of the address blocks of the optical disk of this embodiment, which is the same as that of the second embodiment.
0 and 112 are groove tracks, 111 is a land track, 113, 114, 115, 116, 117 and 11
8, 119 and 120 are address blocks, and 24 is a light spot. FIG. 26B shows an arrangement of data in each address block. Address block 11 of ID1
7 is VFO1 (300), AM (301), address number (302), ID number (303), CRC1 (30)
4), and the ID2 address block 114 includes 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 length of the VFO1 of the address block 117 of ID1 is changed to ID2, ID3, and I2.
The point is that it is about 1.5 to 3 times longer than the VFO of the address block D4.

When the sector address area is irradiated with the light spot 24, the data is reproduced in the order of the data of ID1 and the data of ID2. At this time, while the data area 6 is formed by the track groove, the sector address area 5 is formed by the mirror surface on which the address pit is formed. Therefore, as shown in FIGS. 8A and 8B, the reproduction signal ( The DC signal component (DC level) of the RF signal differs 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. Therefore, in ID1, it takes more time to lock the PLL in order to match the phases of the data read clock and the data (VFO1) than when there is no level change. After ID2, the effect of the level change of the RF signal is reduced, so that the PLL lock in the VFO becomes faster.

To make the data length of all address blocks the same, VFO required by ID1 is used.
Must match the length of the VFO of ID2 to ID4. Therefore, the length of the VFO of ID2 to ID4 becomes longer than necessary, and waste increases. Therefore, in the present embodiment, only the length of the VFO in ID1 is expressed by I
By making it longer than the length of the VFO in D2, ID3 and ID4, the V required for each address block
This makes it possible to optimally set the length of the FO, thereby reducing unnecessary data and maintaining the accuracy of address reading.

Note that the difference between the length of VFO1 (300) in ID1 and the length of VFO2 (305) in ID2 is smaller than the data length of one sector address area.
It hardly affects the average value of the tracking error signal in the sector address area described in the embodiment.

Embodiment 13 Referring to FIG. 27, still another embodiment of the optical disk according to the present invention will be described. FIG.
Shows the address area 405. Address block 411 provided in address area 405
Is a groove track 4 centered on a boundary 409 between the groove track 403 and the land track 402 on the outer peripheral side.
03 and the land track 402, and have different values in all address areas. 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. Track identification mark 412
Is for identifying the groove track 403 from the land track 402 having the same address block 411 or for identifying the land track 402 from the groove track 403, and is provided at the center (408 or 410) of one of the tracks. Can be Here, the track identification mark 412 is provided on the track center 408 of the groove track 403.

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 whether the track being reproduced is a land track or a groove track is determined by whether or not the track identification mark 412 is subsequently reproduced. It is possible.

In FIG. 27, the address block 411 is used to easily and accurately detect a gate pulse signal generated based on the address block 411.
, A track identification mark 412 is arranged. That is, in the reproduction signal, the address block 41
After 1, the track identification mark 412 is reproduced.

As described above, since the reproduction signal differs depending on the track, the land track 402 and the groove track 403 can be identified only from the reproduction signal, and a desired signal can be obtained by using only the reproduction signal regardless of the correspondence between the groove shape and the tracking polarity. Recording and reproduction on a track are enabled.

In the above example, the groove track 40
Although the track identification mark 412 is recorded on the track 3, it is apparent that the same effect can be expected by recording on the land track 402.

FIG. 28 is a diagram showing an optical disk recording / recording operation according to the present invention.
FIG. 13 is a configuration diagram of another embodiment of the playback device. The optical disc recording / reproducing apparatus shown in FIG. 28 records or reproduces information on or from the optical disc shown in FIG. Hereinafter, the CPU 601 is used as the track specifying means, and the track identification mark reproducing means is used as the track identification mark reproducing circuit 60.
4 will be described.

In FIG. 28, 601 and 605 to 61
The circuit indicated by 2 performs the same operation as the operation described in the first embodiment. The ID reproduction circuit 602 converts the signal digitized by the binarization circuit 605 into an address block 4
Address reproduction circuit 603 for reproducing track No. 11 and track identification mark reproduction circuit 6 for reproducing track identification mark 412
04.

FIG. 29 is a block diagram of the track identification mark reproducing circuit 604 for reproducing the track identification mark 412 from the optical disk having the address area of FIG. 701
Is a flip-flop, and 702 is a delay element. Signal b
Is a track identification signal, signal c is a binarized reproduction signal,
The signal d is a gate pulse signal based on the reproduced address.

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 a 1-bit track identification signal for identifying the land track 402 and the groove track 403. Shall be represented.

FIG. 29 shows that the track identification mark 412 is 1
This shows a track identification mark reproduction circuit 604 in the case of being composed of bits. The track identification mark reproducing circuit 604 includes a flip-flop 701 and a delay element 70.
The delay circuit 702 delays the address detection signal d indicating that the immediately preceding address has been reproduced by a predetermined time, and takes in the reproduction signal c into the flip-flop 701 only for the gate section. . With this circuit, the track identification mark 412 (1 bit) reproduced with a certain time delay after the address reproduction is reproduced. Here, the most significant bit of the logical address is obtained based on the presence or absence of the track identification mark 412. When the reproduced track identification mark 412 is composed of a plurality of bits, a track identification signal is generated by comparing the track identification mark 412 with a mark indicating a predetermined land track 402 or a groove track 403. Good.

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.

Finally, when 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 scans the address block 41.
1 and the track identification mark 412 are reproduced. 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 way, 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 tracking can be automatically switched by the reproduction signal for the track identification mark, so that the common tracking can be performed regardless of the characteristics of the disc or the recording / reproducing apparatus. It is possible. 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 disk according to the present invention.
Is shown. The present embodiment is characterized in that the address blocks 411a, 411a,
11b and 411c, the track identification mark 110
1a, 1101b, 1101c, 1102a, 1102
b, 1102c.

Address area 4 of the optical disk shown in FIG.
05 indicates CAV or ZCAV (ZCL) in which the address areas of adjacent tracks are aligned in the radial direction of the disk.
V) It is formed according to the format. In the address area 405, address blocks 411a and 411b are provided to identify the subsequent data area 406. The address block 411b includes the groove track 403b and the land track 4 around the boundary line 409 between the groove track 403b and the land track 402b.
02b, and different addresses are provided in different address areas. Since the address block 411b is provided at the center of the groove track 403b and the land track 403b,
In this disk, the same address block 411b is given to the data area 406 of the adjacent land track 402b and groove track 403b. Further, two track identification marks 1101b and 1102b are formed so as to be shifted from the center 408 of the groove track 403b by about 1/2 track width in the inner and outer peripheral directions. 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. In addition, the groove tracks 403a and 403a on the inner circumference side and the outer circumference side of one track with respect to the groove track 403b.
3c, two track identification marks 110 are similarly provided.
1a, 1102a, 1101c, and 1102c are provided.
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, track identification marks 1101a, 1102a, 110 on the groove tracks 403a, 403c.
1c and 1102c are provided with the same mark 1 (marked with an oblique line rising to the right in FIG. 30), and track identification marks 1101b and 1102 on the adjacent groove track 403b.
The mark b is provided with a mark 2 different from the mark 1 (a hatched mark in the lower right direction 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, for the groove track 403b, 1-bit pits are provided as the track identification marks 1101b and 1102b, and for the adjacent groove tracks on the inner and outer circumferential sides, the track identification marks 1101a and 1102c are provided.
Not to provide a pit. 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, in the reproduction signal, the address block 4
After 11 the track identification marks 1101 and 1102 are reproduced.

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 stored in the address area 405.
b) is reproduced, and when the data of the land track 402b is reproduced, two different track identification marks (1101b and 1102c) are reproduced in the address area 405. 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 or not the track identification marks to be reproduced subsequently match or not. Can be identified.

In the disk shown in FIG. 30, the first track identification marks 1101a, 1101b, and 1101c have the groove track 403b and the groove track 403b.
The second track identification mark 110 is provided on the boundary 409 between the land track 402b and the adjacent land track 402b on the outer peripheral side of the second track identification mark 110.
2a, 1102b and 1102c are groove tracks 40
3b is provided on a boundary line 407 between the land track 402a adjacent to the groove track 403b on the inner peripheral side of the groove track 403b. However, the first track identification mark is provided 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, and the second track identification mark is provided between the groove track 403b and the groove track 403b. The same effect can be obtained with a disc provided on the boundary 409 between the land tracks 402b adjacent on the outer peripheral side.

The case where two track identification marks provided in the address area on the groove track have the same value has been described, but the two track identification marks provided in the address area on the land track have the same value. The same effect can be obtained when the value is provided.

FIG. 31 shows an optical disk recording / recording method according to the present invention.
FIG. 13 is a configuration diagram of another embodiment of the playback device. The optical disk recording / reproducing apparatus of this embodiment is for recording or reproducing information on or from the optical disk shown in FIG. In the following description, the track designation means is assumed to be the CPU 601.
The track identification mark reproducing means will be described as a track identification mark reproduction circuit 1201 and the track identification means will be described as a track identification circuit 1202.

In FIG. 31, 601 and 605 to 61
The circuit indicated by 2 performs the same operation as the operation described in the first embodiment.

The ID reproducing circuit 602 includes a binarizing circuit 605
Address reproducing circuit 603 for reproducing the address block 411 from the signal digitized by the above, a track identification mark reproducing circuit 1201 for reproducing the track identification marks 1101 and 1102, a track identification circuit 120 for identifying the land track 402 and the groove track 403.
Consists of two.

FIG. 32 shows the optical disk 40 shown in FIG.
1 is a configuration diagram of a track identification mark reproducing circuit 1201 that reproduces track identification marks 1101 and 1102 from No. 1. 1701 is a flip-flop, 1302, 130
3, 1304 and 1305 are delay elements.

FIG. 33 shows the optical disk 40 shown in FIG.
1, two track identification marks 1101, 1 reproduced from
FIG. 9 is a configuration diagram of a track identification circuit 1202 that generates a track identification signal b from the signal 102. 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, 14
03 is a comparator for comparing two track identification marks, 1
A flip-flop 404 holds the value of the track identification signal. Reference numerals 1405, 1406, and 1407 denote a gate pulse signal for capturing the two track identification marks 1101 and 1102 and a gate for capturing the comparison result of the two track identification marks 1101 and 1102 by delaying the address detection signal d by a predetermined time. Generate a pulse signal.

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 land track 402 and the groove track 403 (for example, the most significant bit). (1 bit) track identification signal b.

FIG. 32 shows a track identification mark 1101,
This shows a track identification mark reproducing circuit 1201 when 1102 is composed of one bit. The track identification mark reproducing circuit 1201 is a flip-flop 13
01 and delay elements 1302, 1303,
The binarized reproduction signal c is generated by delaying the address detection signal d by the delay elements 1702 and 1703 for a predetermined time to create a gate pulse signal, and the reproduction signal is taken into the flip-flop 1701 only during the section of the gate pulse signal. ing. By this circuit, two 1-bit track identification marks 1 reproduced with a certain time delay after address reproduction.
101 and 1102 are reproduced.

Track identification circuit 1202 shown in FIG.
Are three flip-flops 1401, 1402, 14
04, comparator 1403, delay elements 1405, 1406,
1407. A gate pulse signal obtained by delaying the address detection signal d by a predetermined time by the delay elements 1405, 1406, and 1407, the first track identification mark reproduced by the track identification mark reproduction circuit 1201 is supplied to the flip-flop 1401, The track identification mark is taken into the flip-flop 1402, and the comparator 14
At 03, two track identification marks are compared, and the comparison result is held by a flip-flop 1404. That is, flip-flops 1401, 1402,
A clock terminal 1404 receives a gate pulse signal obtained by delaying the address detection signal d by delay elements 1405, 1406, and 1407 for a predetermined time. With this circuit, a track identification signal for identifying the currently reproduced track is generated as a groove track when the two track identification marks match and as a land track when the two track identification marks are different. The address of each data area is obtained as the most significant bit of the address.

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 identifies the track having the same value as the address block 411b. The marks 1101b and 1102b are reproduced. In the land track 402b, the laser beam scans substantially the center 410 of the land track, and the address block 411b and the two different track identification marks 1101 are scanned.
b and 1102c are reproduced. Since the reproduction signal for the track identification mark to be reproduced differs depending on the track, whether the track currently being reproduced is the land track 402 or the groove track 40 is determined based on the reproduction signal alone.
3 can be identified, and recording / reproduction on a desired track can be performed using only the reproduction signal regardless of the correspondence between the groove shape (groove track or land track) and tracking.

According to the recording / reproducing apparatus described above, the tracking polarity can be automatically switched by the reproduction signals for the two track identification marks.
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.

(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 disk of this embodiment. In FIG. 34, 402 is a land track, 403
f is a groove track, 405 is an address area, 411
Is an address block, and 1501 is a track identification mark.

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. Different addresses are provided in the address area. 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 provided in the determined control information area 150.
At least one land track 40 at two specific locations
Data area 406 on the track center 408 or 410 of one of the 2 or groove track 403
It is provided in. The track identification mark 1501 indicates whether the track provided with the track identification mark 1501 is the land track 402 or the groove track 40.
This is for identifying whether it is 3 or not, and differs between a case where it is provided on a land track and a case where it is provided 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, the polarity of the currently performed tracking is for reproducing the data of the groove track. I understand. 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, it is possible to obtain the correspondence between the groove shape of the track being reproduced and the tracking polarity.

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. I have. That is, the track identification mark 1501 is reproduced temporally after the address block 411 in the reproduction signal. In addition,
In FIG. 34, the track identification mark 1501 is recorded in the data area on the groove track 403, but 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 block diagram showing still another embodiment of the optical disk recording / reproducing apparatus according to the present invention. The optical disk recording / reproducing apparatus shown in FIG.
This is for recording or reproducing 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 polarity determining means as the track polarity determining circuit 1601, and the track selection signal correcting means as the track selecting signal correcting circuit 1602.

In FIG. 35, 601 and 605 to 61
The circuit indicated by 2 performs the same operation as the operation described in the first embodiment. When a track provided with the control information area 1502 is reproduced, the track polarity discrimination circuit 1601 reads the track identification mark 1 from the reproduction signal from the data reproduction circuit 612.
The track 501 taken out and reproduced is identified as a land track or a groove track, and the correspondence between the designated track selection signal and the groove shape (land or groove) of the track is obtained to select the track. It is determined whether or not tracking is correctly performed, and a tracking determination signal is generated. Track selection signal correction circuit 1602
Corrects the track selection signal from the CPU 601 according to whether the tracking polarity of the track polarity discrimination circuit 1601 is correct or not.

FIG. 36 shows a track identification mark 1501 in the control information area 1502 of the optical disk shown in FIG.
FIG. 14 is an example of a configuration diagram of a track polarity determination circuit 1601 that determines whether or not tracking is correctly selected from a (reproduction signal h) and a track selection signal i of the CPU 601. 1701 is an exclusive OR gate, 1702 is a flip-flop, and 1703 is a delay element.

FIG. 37 shows a track polarity discriminating circuit 1601.
5 is an example of a configuration diagram of a track selection signal correction circuit 1602 that corrects a track selection signal i of the CPU 201 based on a track selection determination signal g that has determined whether tracking is correct or not. 1801 is an exclusive OR gate.

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

When the optical disk 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, CP
U 601 outputs a track polarity identification signal k to the track polarity determination circuit 1601. Also, the CPU 601
When a logical address of a track including the control information area 1502 provided with the track identification mark 1501 is given to the linear motor control circuit 607, a seek command for the target track is issued, and the linear motor 609 is driven.
The optical head 610 is moved near the target track. next,
The CPU 601 reaches the target track by outputting a track jump command and a track selection signal i corresponding to whether the track is a land track or a groove track to the focus tracking control circuit 608. When a track selection command is given, the focus tracking control circuit 608 switches the polarity of the tracking control, jumps a half track, and focuses and tracks 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). ) Is assumed to be represented by the track selection signal.

The data reproducing circuit 612 compares the address reproduced by the ID reproducing circuit 602 with the address given by the CPU 601, and if they match, reproduces the data after a fixed time from the address reproduction. When the disc is loaded, the control information area 1502 of the track provided with the track identification mark 1501 is reproduced.

FIG. 36 shows a track polarity discrimination circuit 1601 when the track identification mark 1501 is composed of one bit. For example, a track identification mark 1501
When the (reproduction signal h) indicates 1, the track identification mark 150
1 indicates that the track identification mark 1501 is recorded on the land track 402 when 0 represents 0 on the groove track 402. When the CPU 601 selects the groove track 403, the track selection signal i
Is output, and when it is desired to select the land track 402, 0 is output. The exclusive OR gate 1701 in FIG. 36 detects an error in the 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) from 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. The track polarity discrimination command signal k from the CPU 601 and the address detection signal d from the address reproduction circuit 603 are used as a gate pulse signal for taking the discrimination result of the track selection into the flip-flop 1702. The delay element 1703 delays the address detection signal d for a certain time in order to generate a gate pulse signal when capturing a signal indicating the correctness of the track selection.

Track selection signal correction circuit 160 shown in FIG.
2 performs correction based on the track polarity determination signal g when erroneous tracking is performed by the track selection signal i. When an incorrect track is selected, 1 appears in the track polarity determination signal g. In this case, the track selection signal i is inverted and given to the focus tracking control circuit 608. The exclusive OR gate 1801 in FIG. 37 performs this inversion operation.

When loading a disk or starting up a drive,
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. Correction is made based on the track polarity discrimination signal g for selection of tracking at the time of recording, so that normal tracking is always performed.

Therefore, in an optical disc having at least one track identification mark 1501 provided in the control information area 1502 as shown in FIG. 34, the correspondence between the polarity of the groove track and the land track and the track selection signal output by the CPU 601 is determined in advance. Therefore, recording and reproduction on a desired track can be performed regardless of the correspondence between the groove shape and the tracking polarity. Further, since the tracking polarity can be corrected by providing the track identification mark 1501 only in one track, 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 tracking polarity can be automatically switched by the reproduction signal for the track identification mark. Tracking is possible. Therefore, the compatibility of the optical disc recorded on both the land track and the groove track 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.

In the above embodiment, an optical disk having two or four address blocks in a sector address area has been described. However, three or five or more address blocks are provided in one sector address area. May be. As the number of address blocks increases, the accuracy of address reading improves, and the accuracy of land / groove determination improves.

[0216]

As described above, according to the present invention, a plurality of address blocks are provided in one sector address area on an optical disk capable of recording and reproducing data on a land track and a groove track, and these are arranged with a radius relative to the track center. By arranging the wobble alternately on the inner side and the outer side in the direction, it is possible to reliably read the sector address even if the light spot is out of track, and at the same time, the tracking error signal in the sector address area. Of the tracking control due to the level variation of the tracking control 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 replaced by the overlapping sequence number (depending on whether the track is a land track or a groove track). By correcting according to the (ID number), an accurate address value can be obtained by reading a different address number for each address block within one sector address.

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 overlapping order number of the outer address block are compared. It is possible to identify whether the current track is a land track or a groove track by determining whether or not the address numbers of the two tracks match.

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

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

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a first embodiment of an optical disc 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 disc recording / reproducing apparatus according to the present invention.

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

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

FIG. 7A is a diagram showing a configuration of a sector address area;
(B) is a diagram for explaining an RF signal and a TE signal in a sector address area.

FIG. 8A is a diagram for explaining a track shift of an optical spot and an RF signal.

FIG. 8B is a diagram for explaining a track shift of an optical spot and an RF signal.

FIG. 9A is a layout diagram of address blocks in another embodiment of the optical disc according to the present invention.

FIG. 9B is a layout diagram of address blocks in another embodiment of the optical disc according to the present invention.

FIG. 10A is a layout diagram of address blocks in another embodiment of the optical disc according to the present invention.

FIG. 10B is a layout diagram of address blocks in another embodiment of the optical disc according to the present invention.

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

FIG. 12 is a layout 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 a layout 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 disc recording / reproducing apparatus according to the present invention.

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

FIG. 17B is a block diagram of another land / groove 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 a 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 an AS signal with respect to off-track;

FIG. 23 is a layout 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 showing a case in which one pit data in two adjacent address blocks does not overlap with the other address block.

FIG. 26A is a layout diagram of address blocks in still another embodiment of the optical disc according to the present invention.

FIG. 26B 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 disc recording / reproducing apparatus according to the present invention.

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

FIG. 30 is a layout 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 disc 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 disk recording / reproducing apparatus of the present invention.

FIG. 34 is a layout 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 disc 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 diagram showing a track configuration 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.

[Description of Signs] 5 Sector address area 6, 7 Data area 16, 17, 18, 19 Address block 21, 23 Groove track 22 Land track 25 Address pit 26 Recording mark

Continued on the front page (72) Inventor Takashi Ishida 1006 Kazuma Kadoma, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. Inventor Yuji Takagi 1006 Kadoma Kadoma, Kadoma City, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. 6-96447 (JP, A) JP-A-8-221821 (JP, A) JP-A-8-339540 (JP, A) JP-A 9-147393 (JP, A) (58) Fields investigated (Int. G11B ^7/ 00-7/013 G11B 7/09-7/095

Claims (8)

(57) [Claims] 1. An optical disk recording / reproducing apparatus for an optical disk having a land track and a groove track, wherein each of the land track and the groove track has a plurality of sectors. Each has a sector address area and a data area, The sector address area has a plurality of address blocks, and each of the plurality of address blocks has a corresponding sector among the plurality of sectors. It has a portion indicating an address number for identifying from another sector, and a portion indicating an ID number for identifying from another address block. In the sector address area, the plurality of address blocks include a track. About the track pitch in the inner circumferential direction of the optical disc with respect to the center axis At least one address block formed at a position shifted by a distance, and at least one address block formed at a position shifted by about half of a track pitch in an outer circumferential direction of the optical disk with respect to the track center axis. Wherein at least one of the plurality of sectors on the land track is adjacent to at least one of the plurality of sectors on the groove track in a radial direction of the optical disc, and The sector address area shares at least one address block, and the optical disk recording / reproducing device irradiates a light beam on the optical disk, receives light reflected from the optical disk, and outputs a reproduction signal. A head, and the light beam based on the reproduced signal. A signal detector that generates a detection signal having a signal level that varies according to the position at which the spot passes, and an address block formed at a position shifted in the outer peripheral direction of the optical disc with respect to the track center axis. Sample the signal level of the detected detection signal,
An outer-peripheral-value sample-and-hold unit for holding, sampling a signal level of the detection signal detected for an address block formed at a position shifted in an inner peripheral direction of the optical disc with respect to the track center axis;
An inner peripheral value sample-and-hold unit to be held; and a difference between a signal level of the detection signal held by the outer peripheral value sample-and-hold unit and a signal level of the detection signal held by the inner peripheral value sample-and-hold unit. An optical disc recording / reproducing apparatus, comprising: a driving circuit; and a tracking offset correction circuit that performs tracking correction based on an output of the differential circuit. 2. The optical disc recording / reproducing apparatus according to claim 1, wherein the signal detection unit generates a tracking error signal indicating a distance between a spot of the light beam and an address pit as the detection signal. 3. The optical disk recording / reproducing apparatus according to claim 1, wherein the signal detection unit generates a reflected light amount signal indicating a reflected light amount from the optical disk as the detection signal. 4. The optical disk recording / reproducing apparatus according to claim 3 , wherein the signal detection unit generates, as the detection signal, a level of an envelope of the reproduction signal on the side where the amount of reflected light is small. 5. An optical disk recording / reproducing apparatus, comprising: an address reproduction signal section for detecting an address based on the reproduction signal; and an outer peripheral gate pulse signal and an inner peripheral gate pulse signal based on the address. A timing generation unit that generates the signal, wherein the outer value sample and hold unit samples a signal level of the detection signal in synchronization with the outer value gate pulse signal; 4. The optical disk recording / reproducing apparatus according to claim 1 , wherein the signal level of the detection signal is sampled in synchronization with a value gate pulse signal. 6. The optical disk recording / reproducing apparatus further includes a timing generator that generates an outer peripheral gate pulse signal and an inner peripheral gate pulse signal based on a signal synchronized with the sector address area. The value sample and hold unit samples the signal level of the detection signal in synchronization with the outer peripheral value gate pulse signal, and the inner peripheral value sample and hold unit synchronizes the detection signal with the inner peripheral value gate pulse signal. 4. The optical disk recording / reproducing apparatus according to claim 1 , wherein the signal level is sampled. 7. Each of the plurality of address blocks includes a VFO area having a bit arrangement pattern common to the plurality of address blocks, and the outer-peripheral value sample-and-hold unit is configured to control a position of the optical disc with respect to the track center axis. The signal level of the detection signal detected with respect to the VFO area of the address block formed at a position shifted in the outer peripheral direction is sampled and held, and the inner peripheral value sample and hold unit is arranged at the center axis of the track. 4. The method according to claim 1 , wherein a signal level of the detection signal detected for the VFO area of the address block formed at a position shifted in an inner circumferential direction of the optical disk is sampled and held. An optical disk recording / reproducing apparatus according to any one of the above. 8. The signal level of the detection signal detected for a plurality of address blocks formed at positions shifted in the outer peripheral direction of the optical disk with respect to the track center axis. An average value is sampled and held, and the inner circumference value sample and hold unit detects the plurality of address blocks formed at positions shifted in the inner circumference direction of the optical disc with respect to the track center axis. 4. The optical disk recording / reproducing apparatus according to claim 1 , wherein an average value of signal levels of the detection signal is sampled and held.