JP2003091830A - Optical disk and optical disk device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical disk, in which the auxiliary information shown by a land prepits group is surely detectable. SOLUTION: When the land prepits group arranged corresponding to a sync frame of wobble periods N (where, N is natural number >=4) shows a land prepits data value of '1', a sync prepit is arranged at the position of a leading bit for making the synchronization to the sync frame and also the land prepits are arranged in the quantity of >=(N-1)/2 and <=(N-1) except the sync prepits. Meanwhile, when the land prepits group shows the land prepit data value of '0', the sync prepit is arranged at the position of the leading bit and also the land prepits are arranged in the quantity of <(N-1)/2 except the sync prepits.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a wobble.
A pair of tracks and a land located between adjacent grooves is formed in a spiral or concentric shape from the innermost circumference to the outermost circumference on the disk substrate, and
A land pre-pit group, which is auxiliary information for recording and / or reproducing an information signal in the groove on the land, is formed in advance corresponding to a sync frame having a wobble cycle N (where N is a natural number of 4 or more). The present invention relates to an optical disc and an optical disc device capable of surely detecting auxiliary information indicated by a land prepit group from the optical disc.

[0002]

2. Description of the Related Art Generally, a DVD (Digital V
Optical discs such as erasable discs are capable of recording and / or reproducing information signals such as video information, audio information, computer data, etc. on a disc-shaped disc substrate in a spiral or concentric circular shape with high density. Often used for fast access to the truck.

On the other hand, there is a demand for an optical disc and an optical disc device capable of recording and / or reproducing an information signal at a higher density, and various improvements have been made in order to meet this demand. A method of narrowing the track pitch and the like to increase the density of information signals is adopted. Along with this, in order to accurately read the address information and control the rotation of the optical disc even with a narrow track pitch, the wobbled groove is paired with the land located between the adjacent grooves. Track is formed in a spiral or concentric shape from the innermost circumference to the outermost circumference on the disk substrate, and
An optical disc in which auxiliary information for recording and / or reproducing an information signal in a groove is formed in advance as land prepits on the land and an optical disc recording / reproducing apparatus for recording and / or reproducing this optical disc are, for example, Kaihei 9-326138, JP-A-10-29392
It is disclosed in Japanese Patent Publication No. 6 and the like.

FIG. 15 is a diagram for explaining an example of a conventional optical disc, and FIG. 16 is a diagram for explaining another example of a conventional optical disc.

First, in the optical recording medium, the recording / reproducing method, and the recording / reproducing apparatus disclosed in Japanese Patent Laid-Open No. 9-326138, the CLV (Constant Line) is used.
arVelocity ... The linear velocity is constant) A high-speed recording / reproduction of information signals is performed by using an optical disc of a rotation control system. As shown in FIG.
Has a groove 101 wobbled at a single frequency, and the land 1 located between the adjacent grooves 101.
Land pre-pits (for example, address pits) 103 are recorded in advance on 02 at predetermined intervals.

Further, in the recording / reproducing method and the recording / reproducing apparatus for recording / reproducing the optical disc 100, one groove 101 on the optical disc 100 and the lands 102, 102 adjacent to both sides thereof are irradiated with the beam spot B to form the groove. The wobble signal detected from 101 controls the rotation of the optical disc 100, and the land prepit signal detected from the land prepit 103 on one of the lands 102 causes a recording signal of the optical disc 100.
The position above is detected.

Next, the above-mentioned Japanese Patent Laid-Open No. 10-293926
In the recording clock signal generator disclosed in Japanese Patent Publication,
As an optical disc, a CD-R (CD-Recordable
DVD-R with a recording capacity improved to about 7 times that of e)
(DVD-Recordable) is applied, and also for the purpose of high-density recording / reproduction of information signals, FIG.
As schematically shown in FIG. 2, an optical disc 200 of another example has a groove track 201 wobbled by a wobble signal of a predetermined frequency component and a land track 202 formed between adjacent groove tracks 201 on a disc substrate (not shown). The land pre-pits 203 are formed in a spiral shape or a concentric shape on the land track 202 and have a predetermined phase relationship with the wobble signal. Further, since the optical disc 200 is applied to the DVD-R, the groove track 20 for recording the information signal is recorded.
1 is divided in advance for each sync frame as an information unit. One recording sector is composed of 26 sync frames, and one ECC (ErrorCorr) is further composed of 16 recording sectors.
Rectifying Code) block is configured. One sync frame has a length of 1488 times (1488T) the unit length (hereinafter referred to as T) corresponding to the pit interval defined by the recording format when recording the information signal. Further, the head portion of 14T length of one sync frame is used as synchronization information SY for synchronizing each sync frame.

On the other hand, the land prepits 203 recorded on the land tracks 202 of the optical disc (DVD-R) 200 are recorded for each sync frame. At this time, one land pre-pit 203 is always formed on the land track 202 adjacent to the area in which the synchronization information SY in each sync frame is recorded as a signal indicating the synchronization signal in the pre-information, and the synchronization is performed. Information S
One or two land pre-pits 203 indicating the content of the pre-information to be recorded on the land track 202 adjacent to the first half part in the sync frame other than Y.
(Note that the land pre-pits 203 may not be formed in the first half portion of the sync frame other than the synchronization information SY depending on the content of the pre-information to be recorded.). Further, in one recording sector, land pre-pits 203 are formed in either one of the even-numbered sync frames (EVEN frames) or the odd-numbered sync frames (ODD frames) to record pre-information. It is set according to the content of the information.

In the above-described recording clock signal generator, a signal that carries the phase of the wobble signal extracted from the wobbled groove track 201 and a land prepit signal detected from the land prepit 203 on the land track 202 are used. By comparing the phases, outputting the phase difference signal, and adjusting the phase of the clock signal based on the phase difference signal, it is possible to generate a recording clock signal that is synchronized with the rotation of the optical disc 200 with high accuracy. Has become.

[0010]

By the way, in the above-mentioned conventional optical disc and the optical disc recording / reproducing apparatus to which the conventional optical disc is applied, the grooves formed on the optical discs 100 and 200 are used to increase the density of the information signal. 1
01, 201 and land pre-pits 103, 203 formed on the lands 102, 202 are adapted to narrow track pitches, but the optical discs 100, 2
Since the grooves 101 and 201 formed on 00 are wobbled at a single frequency or a predetermined frequency, both optical disks 100 and 200 record and reproduce information signals while being rotationally controlled at CLV (constant linear velocity). Therefore, it has the problems described in the following items (1) to (3), and these problems will be described with reference to FIG.

FIG. 17 shows a conventional optical disc.
(A) schematically shows a portion where the wobbled phase of the wobbled groove has an opposite phase, and (b) schematically shows a portion where land prepits formed on lands adjacent to both sides of one groove overlap each other. FIG.

The conventional problems will be described in order of items: Since both of the conventional optical discs 100 and 200 are controlled to rotate at CLV (constant linear velocity), some wobble phases of adjacent grooves in the disc radial direction are opposite to each other, and crosstalk from adjacent tracks is large. Therefore, there are a plurality of areas on the optical disk surface that cannot be used for recording because the signal quality deteriorates. Further, since the phases are opposite to each other, problems such as deterioration of the land prepit signal occur.

More specifically, as shown in FIG. 17 (a), three grooves 101 adjacent to each other in the radial direction of the disk are provided.
A case may occur in which the phase of the wobble formed in the middle groove 101 (201) of (201) and the groove 101 (201) in the upper part of the figure is inverted as surrounded by the dotted line. In such a case, in the portion surrounded by the dotted line, crosstalk from the recorded information signal becomes large at a portion where the distance to the adjacent groove 101 (201) is narrowed, resulting in a data error due to signal deterioration, or at the time of recording. For example, erroneous erasure of the already recorded adjacent track may occur.

Further, as shown in FIG. 17 (b), as the wobble phase gradually shifts between the adjacent goulbs 101 (201), one gorub 101 (201) is formed.
The relative positions of the land pre-pits 103 (203) on the lands 102 (202) adjacent to both sides of the land pre-pit 103 (203) also change, and the land pre-pits 103 (203) surrounded by the dotted line on both sides of one gourb 101 (201) There are places where they overlap each other. In this way, in the area surrounded by the dotted line, the output of the land prepit signal detected from the land prepit 103 (203) cannot be sufficiently obtained, and the reading of the land prepit signal is affected.

For this reason, as described above, digital information signals are not recorded or land prepits 103 (203) are recorded between the adjacent grooves 101 (201) where the wobble phases are opposite to each other. It was necessary to take measures such as not recording.

.. Also, one Gourb 101 (20
In the case where the land pre-pits 103 (203) on the lands 102 (202) adjacent to both sides of 1) overlap each other, the information signal cannot be reproduced at these places, and therefore the land pre-pits 103 (203). It is necessary to perform processing such as changing the position of.

.. Further, when performing data seek for a large distance in the radial direction of the optical disc 100 (200), it takes a long time for the number of revolutions of the spindle motor for optical disc rotation to settle within a data recordable or reproducible range. take time.

.. In addition, the land pre-pit 103 (20
When the data to be expressed in 3) is read, it is detected that there is a land prepit signal in a place where the land prepit 103 (203) is not originally present due to noise or the like,
The land pre-pits 103 (20) that should originally exist under the influence of the information signal recorded in the groove 101 (201)
3) cannot be detected correctly, land pre-pit 1
There is a high probability that the data value indicated by 03 (203) will be erroneously detected, and as a result, the auxiliary information indicated by the land pre-pit 103 (203) cannot be correctly detected, which is likely to cause a problem.

Therefore, the problems described in the above items (1) to (4) can be solved, particularly, the detection error of the land prepit data due to the influence of noise and information signals can be reduced, and the auxiliary information indicated by the land prepit can be more accurately obtained. Optical discs and optical disc devices capable of detection are desired.

[0020]

The present invention has been made in view of the above problems, and the first invention is a groove wobbled in a sine wave shape (or a cosine wave shape) and the adjacent groove. A track paired with a land located in between is formed in a spiral or concentric shape from the innermost circumference to the outermost circumference on the disk substrate, and an information signal is recorded in the groove on the land. And / or auxiliary information for reproduction is formed in advance as land pre-pits, and the recording area for the information signal is divided into a plurality of zones in the radial direction, and the number of rotations is gradually increased in each zone. An optical disc which is switched to a constant linear velocity and is controlled to have a constant angular velocity in each zone at a rotational speed set for each zone, wherein the groove is a wobble in each zone. The phases are always formed in the same phase, and one sync frame is composed of a wobble period N (where N is a natural number of 4 or more), and a sector is composed of a predetermined number of sync frames. The pre-pits are formed on the land at a predetermined position of the wobble phase of the groove, and the land pre-pits have N bit numbers corresponding to the wobble period N for arranging the land pre-pits. Groups are installed every other sync frame on the land,
The land pre-pit group on one land and the land pre-pit group on the land that is adjacent to one land via the groove are installed with a phase offset by one sync frame from each other. , When the land prepit group indicates a land prepit data value “1”, a sync prepit for synchronizing with the sync frame is arranged at the head bit position, and the sync prepit is excluded. (N-1) / 2 or more land pre-pits and (N
-1) or less, and when the land prepit group indicates a land prepit data value "0", the sync prepit is arranged at the head bit position, and the sync prepit is excluded. The optical disc is characterized in that less than (N-1) / 2 land pre-pits are arranged.

In a second aspect of the invention, in the optical disc of the first aspect, the land prepit group arranged at the head position of the sector has a specific bit position excluding the sync prepit. Set as the sector sync bit position to synchronize with the sector,
Further, the optical disc is characterized in that when the land pre-pit data value is "1", the sector synchronization bit is not arranged, while when the land pre-pit data value is "0", the sector synchronization bit is arranged.

A third aspect of the invention uses the optical disc of the first or second aspect of the invention, wherein the track on the optical disc is irradiated with a beam spot emitted from an optical pickup and reflected from the track. The reflected light is photoelectrically converted by a photo detector in the optical pickup to detect a wobble signal corresponding to the wobble of the track, and also detect each land prepit signal of the land prepit group on the land. In the optical disc device configured as described above, the photo detector is divided into an outer peripheral side and an inner peripheral side along the track, and the difference between the optical sensor output on the outer peripheral side and the optical sensor output on the inner peripheral side is divided. And a radial push-pull signal generation circuit that outputs a radial push-pull signal, and from the radial push-pull signal A wobble signal detection circuit that detects a wobble signal, a wobble clock generation circuit that generates a wobble clock from the wobble signal, and a land pre-pit signal that detects each land pre-pit signal of the land pre-pit group from the radial push-pull signal. Based on the pit signal detection circuit, the wobble clock, and each land prepit signal of the land prepit group, the number of land prepits excluding the sync prepit located at the head of the land prepit group is (N -1) / 2 or more and (N-1) or less, the land prepit data value is determined to be "1", while the sync prepit located at the head of the land prepit group is determined. Except for the number of land pre-pits (N
An optical disc device comprising: a land prepit data detection circuit that determines that the land prepit data value is "0" when the number is less than -1) / 2.

Further, in the optical disc device of the fourth invention, is the land prepit data detection circuit arranged with a sector synchronization bit at a specific bit position excluding the sync prepit in the land prepit group? If the land prepit data value indicated by the land prepit group is "1" and the sector synchronization bit is not arranged, and if the land prepit data value indicated by the land prepit group is The optical disk device is characterized in that when it is "0" and the sector synchronization bit is arranged, it is determined to be the land pre-pit group arranged at the head position of a sector.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an optical disk and an optical disk device according to the present invention will be described below in detail in the order of <optical disk> and <optical disk device> with reference to FIGS.

<Optical Disc> FIG. 1 is a perspective view for explaining an optical disc according to the present invention, and FIG. 2 is a plan view showing the structure of zones in the optical disc according to the present invention.

As shown in FIG. 1, the optical disc 1 according to the present invention has a disc-shaped transparent disc substrate 2 having a thickness of, for example, about 0.6 mm, which is formed on one side of the disc substrate 2. A track in which a groove 3 wobbled in a sine wave shape (or a cosine wave shape) and a land 4 located between the adjacent grooves 3 are paired, extends from the innermost circumference to the outermost circumference on the disk substrate 2. Auxiliary information for recording and / or reproducing an information signal in the groove 3 is formed in advance as a land prepit 5 on the land 4 in a spiral or concentric shape.

As for the shapes of the groove 3 and the land 4, the groove 3 is generally formed in a concave shape and the land 4 is formed in a convex shape. However, if the surface irradiated with the beam spot B is reversed, both of them are formed. In order to reverse the concavo-convex relationship, one of the concavo-convex shapes of the groove 3 and the land 4 may be formed in a concave shape and the other in a convex shape.

At this time, the groove 3 serves as a recording track for recording an information signal, while the land pre-pits 5 formed on the land 4 serve as auxiliary information of the information signal such as address information and correction parity. Are recorded in advance in a concave (or convex) form.

On the groove 3 and the land 4, a phase change recording layer 6 made of a phase change material, a metal reflection layer 7 made of Al (aluminum), Au (gold), etc., and a protective layer 8 are provided. Are sequentially formed, and a reinforcing substrate 9 having a thickness of about 0.6 mm is attached to the protective layer 8 side with an adhesive to form an optical disc 1 having a total thickness of 1.2 mm.

Therefore, the information signal can be overwritten and the information signal can be additionally written by the phase change recording layer 6 formed on the groove 3, and a DVD-RW (DVD-Rewriteab) can be obtained.
le) and the like.

Then, a beam spot B is applied to one groove 3 and the lands 4 and 4 adjacent to both sides of the groove 3 from the other surface side of the transparent disk substrate 2.
The beam spot B passes through the disc substrate 2 and the phase-change recording layer 6 and is reflected by the metal reflection layer 7 to provide return light, which is provided in an optical disc device 10 (FIG. 6) described later. It is detected by the radial push-pull method using 16 g (FIGS. 8 and 9).

When it is necessary to reduce the thickness of the disk substrate located on the information signal reading side in order to further improve the recording density on the optical disk 1, the thickness is 0. A track in which a groove and a land having land prepits are paired is formed spirally or concentrically on a thick disk substrate of about 5 mm to 1.1 mm, and a metal reflection layer and a phase change recording layer are formed on these groove and land. , And a thin transparent film having a thickness of about 0.1 mm to 0.2 mm is adhered to the phase-change recording layer side with a transparent adhesive, and a beam spot is irradiated from the thin transparent film side. There is also a method of forming.

Further, as shown in FIG. 2, in the optical disc 1 according to the present invention, the recording area of the groove 3 for recording the information signal is concentric with the center hole 2a of the disc substrate 2 along the radial direction of the optical disc 1. Is divided into multiple zones. At this time, as an example, when the optical disc 1 is formed to have a diameter of 12 cm and the recording area is divided into Z from zone 0 to zone Z-1, the number of zones Z is, for example, 83, and Is composed of, for example, 1024 tracks.

The rotation control method for the optical disc 1 is as follows.
ZCLV (Zone Constant) in which the number of rotations of the optical disk 1 is sequentially changed step by step from zone 0 to zone Z-1 and rotation is controlled at a substantially constant linear velocity.
A linear velocity (ZCAV) system is adopted, and the ZCLV (Zone Constant Angular) is always controlled to have a constant angular velocity at a constant rotation speed set for each zone by the ZCLV.
r Velocity) method is adopted.

Furthermore, by rotating at a constant rotation speed in each zone by the ZCAV method, 1024 is generated in each zone.
Since the wobbles of the groove 3 of the book are all formed in the same phase, there is no phenomenon such that the adjacent grooves 3 in each zone have opposite phases. Therefore, the gap between the grooves 3 is narrowed. No crosstalk from adjacent tracks is generated.

Next, with reference to FIGS. 3 to 5, description will be given centering on each land prepit 5 of the land prepit group (LPPG) formed on the land 4 in an appropriate zone on the optical disk 1. .

FIG. 3 shows an optical disc according to the present invention.
FIG. 4 is a diagram schematically showing land prepit groups on lands formed between adjacent grooves, FIG. 4 is a diagram schematically showing a sector structure by land prepit groups in the optical disc according to the present invention, and FIG. FIG. 6 is a diagram showing a format of a land pre-pit data block in the optical disc according to the present invention.

As shown in FIG. 3, in an appropriate one zone on the optical disk 1, adjacent grooves 3-, 3- are formed.
, 3, ... Are all wobbled in the same phase along the disk circumferential direction. Further, the land pre-pits 5 formed on the lands 4 are connected to the adjacent grooves 3 and 3-, 3- and 3-3, and have a predetermined wobble phase of sine wave (or cosine wave). Is formed at a position, for example, the corrugated peaks (or valleys) of the groove 3
Is formed at a substantially peak position of.

Further, one wobble period N of the groove 3 (where N is a natural number of 4 or more) constitutes one sync frame. Further, one land prepit group (LPPG) having N bits is provided to arrange the land prepits 5 on one land 4 in one sync frame.

The land pre-pit groups (LPPG) on one land 4 are arranged in every other sync frame along the circumferential direction of the optical disc 1. In addition, the land pre-pit group (L
PPG) and a land pre-pit group (L) on the land 4 adjacent to one land 4 via the groove 3.
PPG) are set so that only one sync frame is out of phase with each other, so that land pre-pit groups (LPPG) on lands 4 adjacent to each other via the groove 3 do not overlap each other in the same sync frame. ing.

Specifically, a land prepit group (LPPG) is arranged on, for example, every odd sync frame on one land 4-, while one land 4- is arranged.
Land 4 adjacent to groove 4 through
In the above, the land pre-pit group (LPPG) is arranged for every even sync frame, for example. This prevents the land prepit groups (LPPG) from overlapping in the same sync frame between the lands 4 and 4 that are adjacent to each other via the groove 3.

When an information signal is recorded on the groove 3 or a recorded information signal is reproduced and the information signal unit is a sector, one sector has 26 sectors as shown in FIG. 5 sync frame (sync frame S0 to sync frame S25). Further, as shown in FIG. 5, one ECC (Errro) is composed of 32 sectors.
r Correcting Code) block.

Returning to FIG. 3 again, the land pre-pit group (LP) formed on the land 4 in sync frame units is used.
PG) is the zone address or ECC on the optical disc 1.
It indicates a land pre-pit data value and a sector synchronization data value for indicating auxiliary information including an address and the like.
There are various types of land prepit groups A to land prepit groups D.

At this time, the beam spot B is set to the groove 3-
Land pre-pit groups A, B,
Although D and C are detected in order, the land prepit group A and the land prepit group D on the land 4-have auxiliary information corresponding to the groove 3-,
On the other hand, since the land pre-pit group B and the land pre-pit group C on the land 4-have auxiliary information corresponding to the groove 3-, when the auxiliary information corresponding to the groove 3-is obtained, the land 4- Only the land pre-pit group A and the land pre-pit group D above should be extracted.

Here, in a sync frame having a wobble period N, for example, four kinds of land prepit groups A to land prepit groups D when N = 6 is set.
Will be described below, but N may be any number as long as it is a natural number of 4 or more.

First, when the wobble period N = 6 is set, the four types of land prepit groups A to D have a common number of land prepits 5 of 1 or more and 6 or less. Moreover, the sync pre-pit 5a for synchronizing with the sync frame is always provided at the head bit position.

Next, the land pre-pit group A indicates that the land pre-pit data value is "1" and that it is arranged at the head position of the sector. Specifically, the land pre-pit group A is the fourth sector. The bit array (111011) is set by providing the land pre-pits 5 at each bit position excluding the synchronization bit position.

Next, the land pre-pit group B indicates that the land pre-pit data value is "0" and that it is arranged at the head position of the sector. The land pre-pits 5 are provided at the position and the fourth sector synchronization bit position, and the land pre-pits 5 are not provided at the remaining bit positions, so that the bit array (100100) is set.

Next, the land pre-pit group C indicates that the land pre-pit data value is "1" and that it is arranged at a position other than the beginning of the sector.
Specifically, the bit array (111111) is set by providing the land prepits 5 at all the bit positions including the leading sync bit position.

Next, the land pre-pit group D indicates that the land pre-pit data value is "0" and that it is arranged at a position other than the beginning of the sector.
Specifically, the land pre-pit 5 is provided only at the leading sync bit position, and the land pre-pit 5 is provided at each of the remaining bits.
The bit array (100,000) is set by not providing.

When the wobble period N is generalized and set to a natural number of 4 or more, the above-mentioned four types of land prepit groups A to D are always located at the head bit position (sync bit position). The land pre-pits 5 are (N-1) / 2 except that the sync pre-pits 5a are arranged.
More than or equal to and less than (N-1) are arranged.

When the land pre-pit data value is set to "1", each of the (N-1) bit positions except the leading sync bit position is temporarily set to "1", while the land When setting the pre-pit data value to "0", the sync bit position at the beginning is excluded (N-1)
Each of the bit positions is provisionally set to “0”, and further, the sector synchronization bit position is provisionally set to “1” when indicating the beginning of the sector, and the sector synchronization bit position is provisionally set when indicating other than the beginning of the sector. It is only necessary to set it to "0" and then perform an exclusive OR (EX-OR) between the terms with respect to the sector synchronization bit position.

That is, if the land prepit data value and the sector synchronization bit value are (1, 1) between the terms, EX-OR = 0 and the sector synchronization bit position is set as in the land prepit group A. If the land prepit data value and the sector synchronization bit value are (0, 1) without arranging the land prepits, EX-OR = 1 and the land prepits are located at the sector synchronization bit position as in the land prepit group B. If the land pre-pit data value and the sector sync bit value are (1,0), EX-OR = 1 and the land pre-pits are arranged at the sector sync bit positions as in the land pre-pit group C. If the pre-pit data value and the sector sync bit value are (0,0), E
When X-OR = 0, the land prepits may not be arranged at the sector synchronization bit position like the land prepit group D.

Therefore, when the above relationships are summarized, the land prepit group arranged at the head position of the sector is
A specific bit position excluding the sync pre-pit 5a is set as a sector sync bit position for synchronizing with the sector, and when the land pre-pit data value "1" is indicated, the sector sync bit is not arranged, On the other hand, when the land pre-pit data value indicates "0", the sector synchronization bit is arranged.

As described above, since the pre-pit group (LPPG) is arranged in every other sync frame, when one sector is composed of 26 sync frames, the land pre-positions arranged in one sector are arranged. The number of pit groups is 13. Further, since each land prepit group indicates a land prepit data value, data per sector is 13 bits. Furthermore, when one ECC block is composed of 32 sectors,
By using the block data of 32 sectors × 13 bits, the Land Pre-Pit Data Blo shown in FIG.
Zone address and ECC like ck format example
Auxiliary information such as a block address is displayed. Note that the sector configuration and block data format described above are examples, and other sector configurations and block data formats may be used.

Then, in the optical disc 1 according to the present invention,
The land prepit group (LPPG) does not represent the land prepit data value indicated by the land prepit group (LPPG) in all the land prepit arrays in the sync frame of the wobble cycle N (N is a natural number of 4 or more), but the land prepit group Depending on whether or not the land prepits 5 are arranged other than the sync prepit 5a arranged at the head bit position in (LPPG), the land prepit group (LPP)
G) indicates the land pre-pit data value,
Moreover, since the specific bit position in the land pre-pit group (LPPG) is set as the sector synchronization bit position for synchronizing with the sector, the optical disc 1 according to the present invention will be described later. Device 1
0 (FIG. 6), it is possible to reliably detect the land prepit data value indicated by the land prepit group (LPPG) in the optical disk device 10, and further, the land prepit group located at the head position of the sector. (LPP
G) can be reliably detected.

<Optical Disk Device> FIG. 6 is a block diagram showing an optical disk device according to the present invention, FIG. 7 is an enlarged block diagram showing the inside of the land pre-pit data detection circuit shown in FIG. 6, and FIG. FIG. 9 is an enlarged view of the optical pickup in the optical disc apparatus according to the invention, FIG. 9 is an enlarged view of the photo detector in the optical pickup shown in FIG. 8, and FIG. 10 is an optical disc apparatus according to the present invention. FIG. 3 is a waveform diagram showing the waveform of an output signal from each circuit.

The optical disk device 10 according to the present invention shown in FIG. 6 is constructed so that an information signal can be recorded and / or reproduced by using the optical disk 1 according to the present invention described above.

In the optical disk device 10 described above, the optical disk 1 on the turntable 13 fixed to the motor shaft is rotated via the spindle motor 12 by the motor drive signal 11a from the motor drive circuit 11. At this time, as described above, the motor drive circuit 11 sequentially and stepwise switches the number of rotations of the optical disc 1 by ZCLV for each zone in the optical disc 1 to control the rotation at a substantially constant linear velocity, and within each zone. The ZCAV controls the rotation at a constant angular velocity at the number of rotations set corresponding to each zone.

An optical pickup 16 is provided so as to face the optical disc 1 and is movable in the radial direction of the optical disc 1.

In the optical pickup 16 described above, as shown in an enlarged view in FIG. 8, the laser beam from the semiconductor laser 16b installed inside the optical pickup housing 16a is collimated by the collimator lens 16c to form a beam splitter 16.
The beam spot B which is made incident on the objective lens 16e via d and is narrowed down by the objective lens 16e is irradiated onto the groove 3 (FIG. 1) and the land 4 (FIG. 1) formed on the optical disc 1 and also on the optical disc 1. The irradiated beam spot B is the metal reflection layer 6 of the optical disc 1 (FIG. 1).
The return reflected light reflected by 4 is transmitted through the objective lens 16e, the beam splitter 16d, and the condenser lens 16f to 4
It is detected by the split type photo detector 16g. At this time, when the beam spot B is irradiated from the objective lens 16e in the optical pickup 16 to the groove 3 and the land 4 on the optical disc 1, the beam spot B is tracked with respect to the groove 3 by a tracking means (not shown), and The beam spot B is focused on the groove 3 on the optical disc 1 by a focusing means (not shown).

Here, as shown in an enlarged view in FIG. 9, the four-division type photo detector 16g provided in the optical pickup 16 is formed in a substantially rectangular shape, and is a straight line along the radial direction of the optical disc 1. Although the entire light receiving area is divided into four equal parts by the straight line along the groove direction (track direction), when photoelectrically converting the reflected light returning from the optical disk 1 imaged on the photo detector 16g. The optical disc 1 is divided into two sets, that is, a set of two optical sensors A and B on the outer circumference side and a set of two optical sensors C and D on the inner circumference side. It is in a state of being divided into an outer peripheral side and an inner peripheral side along the direction.

Returning to FIG. 6, the disc substrate 2 of the optical disc 1
A laser drive is used to detect a wobble signal and each land prepit signal in a land prepit group from a track in which a groove 3 and a land 4 wobbled in a sine wave (or cosine wave) are combined. In the circuit 15, the laser power is switched between the time of recording on the optical disc 1 and the time of reproducing, and the laser drive signal 15a for obtaining a strong laser power at the time of recording is supplied to the semiconductor laser 16b (FIG. 8) in the optical pickup 16. On the other hand, the optical pickup 16 supplies the laser drive signal 15a which supplies a weak laser power during reproduction.
It is supplied to the semiconductor laser 16b (FIG. 8).

When the beam spot B emitted from the optical pickup 16 is applied to the track on the optical disk 1 and the reflected light reflected from this track is photoelectrically converted by the photo detector 16g in the optical pickup 16. , Photo detector 16 in optical pickup 16
g (FIGS. 8 and 9) sends to the (A + B) circuit 17 A and B current signals having current values proportional to the amount of light received by the optical sensors A and B on the outer peripheral side as outer peripheral side optical sensor signals. Here, the A and B current signals are voltage-converted and both are added to obtain (A + B) voltage signal 17a, and this (A + B) is obtained.
The voltage signal 17a is supplied to the {(A + B)-(C + D)} circuit 20.
Have been sent to.

Further, the photo detector 16g (FIGS. 8 and 9) in the optical pickup 16 has a current value proportional to the amount of light received by the optical sensor C and the optical sensor D on the inner peripheral side as an inner peripheral side optical sensor signal. C, D current signal of (C + D) circuit 1
8 and the C and D current signals are converted into voltage there, and both are added to obtain a (C + D) voltage signal 18a, and this (C + D) voltage signal 18a is {(A + B)-(C +
D)} is sent to the circuit 20.

Further, the photodetector 16g (FIGS. 8 and 9) in the optical pickup 16 uses the (A + B + C + D) circuit for the A to D current signals whose current values are proportional to the amounts of light received by the optical sensors A to D. The voltage signals of the A to D current signals are converted to a voltage signal and are all added to obtain an (A + B + C + D) voltage signal 19a which is an RF signal, and the RF signal 19a is also sent to the recording / reproducing circuit 14. At this time, in the recording / reproducing circuit 14, the RF signal 19a from the (A + B + C + D) circuit 19 is decoded only during reproduction of the optical disc 1, and reproduction data based on the information signal recorded on the optical pickup 16 is output.

Next, the {(A + B)-(C + D)} circuit 2
0 is also called a radial push-pull signal generation circuit. This {(A + B)-(C + D)} circuit 20
Then, the difference between the (A + B) voltage signal 17a output from the (A + B) circuit 17 and the (C + D) voltage signal 18a output from the (C + D) circuit 18 is calculated to be {(A +
B)-(C + D)} voltage signal to obtain a radial push-pull signal 20a, and as shown in FIG. 10A, the waveform radial including the wobble signal and each land prepit signal in the land prepit group is obtained. The push-pull signal 20a is sent to the wobble signal detection circuit 21 and the land pre-pit signal detection circuit 22, respectively.

Next, the wobble signal detection circuit 21 detects the wobble of the groove 3 formed on the optical disc 1. In this wobble signal detection circuit 21,
The radial push-pull signal 20a from the {(A + B)-(C + D)} circuit 20 is removed through a bandpass filter (not shown) to remove the influence of the land pre-pits 5 to obtain a wobble signal 21a, thereby obtaining the wobble signal 21a shown in FIG. The wobble signal 21a having a waveform as shown in () is sent to the wobble clock generation circuit 23.

Next, the wobble clock generation circuit 23 outputs the wobble signal 21 from the wobble signal detection circuit 21.
A wobble clock 23a synchronized with the wobble signal 21a is generated based on a, and the wobble clock 23a having a waveform as shown in FIG. 10 (d) is supplied to the land pre-pit data detection circuit 24 and the motor drive circuit 11 described above. Have been sent to. At this time, the above-mentioned motor drive circuit 11 generates a motor drive signal 11a for ZCLV and ZCAV control of the rotation of the spindle motor 11 by the wobble clock 23a obtained for each zone of the optical disc 1 and synchronized with the wobble signal 21a. ing.

Next, the land pre-pit signal detection circuit 22
Is for detecting the land prepit signal 22a by each land prepit 5 in the land prepit group formed on the land 4 of the optical disc 1. In this land pre-pit signal detection circuit 22, {(A + B)-(C
+ D)} radial push-pull signal 20 from circuit 20
The land prepit signal 22a is obtained by binarizing a by a predetermined threshold value, and the land prepit signal 22a having a waveform as shown in FIG. 10B is sent to the land prepit data detection circuit 24. There is. At this time, FIG.
In the radial push-pull signal 20a shown in FIG. 5, for example, odd-numbered sync frames S5 on one land 4 are included.
Although positive land pre-pit signals can be detected from S7, and even-numbered sync frames on the land 4 adjacent to one land 4 can be detected, negative land pre-pit signals can be detected from S6, but even-numbered sync frames Since S6 is not necessary, the land prepit signal of the even-numbered sync frame S6 is removed by using the negative polarity.

Next, the land pre-pit data detection circuit 2
Reference numeral 4 denotes the land prepit signal 22a from the land prepit signal detection circuit 22 and the wobble clock generation circuit 2
The wobble clock 23a from 3 is used to determine the land prepit data value and the sector synchronization data indicated by the land prepit group (LPPG).

The internal structure of the land prepit data detection circuit 24 will be described with reference to FIG. 7. The land prepit data detection circuit 24 includes an AND circuit (logical product circuit) 25 and a land prepit gate. The signal generation circuit 26, the land pre-pit counter 27, the counter enable signal generation circuit 28, the sector synchronization bit detection circuit 29, and the land pre-pit data determination circuit 3
0 and an EX-OR circuit (exclusive OR circuit) 31.

In the land prepit data detection circuit 24 described above, the land prepit signal detection circuit 22
The land pre-pit signal 22a detected in (FIG. 6) is A
It is input to the ND circuit 25.

The wobble clock 23a generated by the wobble clock generation circuit 23 (FIG. 6) is used for the land prepit gate signal generation circuit 26, the counter enable signal generation circuit 28, the sector synchronization bit detection circuit 29, and the land prepit data determination. It is input to each circuit 30.

In the land pre-pit gate signal generation circuit 26 described above, the correct land pre-pits located at the regular position as shown in FIG. 10 (e) based on the wobble clock 23a input here. Signal 22a
Gate signal 26 with a pulse width narrow enough to extract only
a and generates this gate signal 26a by the AND circuit 25
Are typing in.

Next, the AND circuit (logical product circuit) described above
25, land pre-pit signal 22a and gate signal 2
6a is calculated, and FIG.
The post-gate land pre-pit signal 25a having a waveform as shown in (f) is obtained, and the post-gate land pre-pit signal 25a is supplied to the land pre-pit counter 27, the counter enable signal generation circuit 28, and the sector synchronization bit detection circuit 29. We are sending each. At this time, the AND circuit 25 is for removing the false land pre-pit signal included in the land pre-pit group (LPPG) due to noise or the like, and is not expected timing, that is, outside the range of the gate signal 26a. Although the existing land pre-pit signal is not detected as a false land pre-pit signal, the gate signal 26a is not detected.
The false land pre-pit signal generated within the range is detected as it is.

Next, in the counter enable signal generating circuit 28 described above, the wobble clock 2 input here is input.
3a and the land pre-gate signal 25a after gate are used to detect the sync pre-pit 5a in the land pre-pit signal 25a after gate, when the wobble period N of the groove 3 is set to 6 as described above, A counter enable signal 28a having a waveform length of 5 wobble cycles from the rising of the next wobble clock 23a of the wobble clock 23a corresponding to the pre-pit 5a.
Is generated as shown in FIG. 10 (g), and this counter enable signal 28a is sent to the land prepit counter 27 and the land prepit data determination circuit 30, respectively.

Next, in the land pre-pit counter 27 described above, the land pre-pit number of the post-gate land pre-pit signal 25a, excluding the sync pre-pit 5a, is shown in FIG. 10 (while the counter enable signal 28a is HIGH). The count is performed as shown in (h), and the counted land prepit count value 27a is sent to the land prepit data determination circuit 30. At this time, in the operation of the land pre-pit counter 27, not only the post-gate land pre-pit signal 25a located at the regular position but also the false land pre-pit signal generated within the range of the gate signal 26a are counted, Further, the state in which the post-gate land pre-pit signal 25a cannot be detected even though it is located at the regular position is counted.

Next, in the land prepit data determination circuit 30 described above, the land prepit count value 27a is latched at the trailing edge of the counter enable signal 28a input here. When the wobble period N of the groove 3 is set to 6, the land prepit count value 27a, that is, the land prepit group (LPP).
If the number of land prepits other than the sync prepit 5a in G) is (N-1) / 2 = (6-1) / 2 or more, the land prepit data value indicated by the land prepit group (LPPG) Is determined to be “1”, and
As shown in (j), "1" is output as the land prepit data 30a to the land prepit data decoding circuit 32 (FIG. 6) and the EX-OR circuit 31.

On the other hand, the land prepit count value 27a is (N-1) / 2 with the sync prepit 5a removed.
= (6-1) / 2, it is determined that the land prepit data value indicated by the land prepit group (LPPG) is “0”, and the land prepit data 30
“0” as a is the land pre-pit data decoding circuit 32
(FIG. 6) and the EX-OR circuit 31.

The land pre-pit data determination circuit 3
0 is a reset signal 30b for resetting the land prepit count value 27a of the land prepit counter 27 at the rising timing of the wobble clock 23a after the count enable signal 28a falls.
Is sent to the land pre-pit counter 27.

Next, the sector sync bit detection circuit 29 uses the wobble clock 23a and the post-gate land pre-pit signal 25a input therein to generate the groove 3
When the sync prepit 5a is detected from the post-gate land prepit signal 25a when the wobble cycle N of the above is set to 6 and the sector sync bit position is set to, for example, the 4th bit, the wobble corresponding to the sync prepit 5a is detected. Wobble clock 2 3 cycles after clock 23a
The presence or absence of the land pre-pits 5 for sector synchronization during the HIGH period of 3a is detected. That is, the sector synchronization bit located at the 4th bit in the land prepit group (LPPG) is detected. Then, the value of the detected sector synchronization bit is the runt prepit data 30 described above.
At the timing of the rising edge of the wobble clock 23a after three more cycles so that the phase matches the change point of a,
As shown in FIG. 10 (i), the sector synchronization bit detection signal 29a is obtained and the sector synchronization bit detection signal 29a is obtained.
a is sent to the EX-OR circuit 31.

Next, in the EX-OR circuit (exclusive OR circuit) 31, the exclusive OR of the land pre-pit data 30a and the sector synchronization bit detection signal 29a input here is calculated, and the calculation result is obtained. Thus, the sector synchronization data 31a having a waveform as shown in FIG. 10 (k) is obtained, and this sector synchronization data 31a is output to the land pre-pit data decoding circuit 32 (FIG. 6).

Here, the operation example of the land pre-pit data detection circuit 24 described with reference to FIGS. 6 and 7 will be described more specifically with reference to FIGS. 11 to 14.

11 to 14 are first to fourth mode diagrams for explaining the operation of the land prepit data detection circuit shown in FIG.

First, in the first mode diagram shown in FIG. 11, when the wobble period N of the groove 3 is set to 6 on the optical disc 1, the land pre-pit data value “1” is set on the land 4.
The land pre-pit group A indicating is (1, 1, 1,
0, 1, 1) bit arrangement, and since the sector synchronization bit is not set at the 4th bit position, when this land pre-pit group A is located at the beginning of the sector, this land The case where the pre-pit group A is detected as a bit array of (1,0,1,0,1,1) in the optical disk device 10 is shown.

That is, here, a detection error occurs due to the lack of the land pre-pit signal which should originally exist in the second bit position. And land pre-pit group A
Among them, the number of land pre-pits excluding the leading sync pre-pit 5a is 3, and this land pre-pit number 3 is (N-
Since 1) / 2 = (6-1) /2=2.5 or more, the land prepit data value is determined to be "1". The sector sync bit is detected as "0". Therefore, when EX-OR is performed with the land pre-pit data value "1" and the sector synchronization bit "0", the sector synchronization data value is determined to be "1", whereby the land pre-pit group A has the second bit position. Despite the occurrence of the detection error, the judgment is made with the same value as each value (land pre-pit data value, sector synchronization data value) in the normal state.

Next, in the second mode diagram shown in FIG. 12, when the wobble period N of the groove 3 is set to 6 on the optical disk 1, the land pre-pit data value “0” is set on the land 4.
Land pre-pit group B indicating (1, 0, 0,
1, 0, 0) and the sector synchronization bit is set at the 4th bit position. Therefore, when this land prepit group B is located at the beginning of the sector, this land The case where the pre-pit group B is detected as a bit array of (1,0,1,1,0,0) in the optical disc device 10 is shown.

That is, in this case, a false land prepit signal has risen at the third bit position, so that a detection error has occurred. The number of land pre-pits in the land pre-pit group B excluding the leading sync pre-pit 5a is 2, and this land pre-pit number 2 is (N-
Since 1) / 2 = (6-1) /2=2.5 is less than 2.5, the land prepit data value is determined to be "0". The sector sync bit is detected as "1". Therefore, when EX-OR is performed with the land pre-pit data value "0" and the sector synchronization bit "1", the sector synchronization data value is determined to be "1", whereby the land pre-pit group B has the third bit position. Despite the occurrence of the detection error, the judgment is made with the same value as each value (land pre-pit data value, sector synchronization data value) in the normal state.

Next, in the third mode diagram shown in FIG. 13, when the wobble period N of the groove 3 is set to 6 on the optical disc 1, the land pre-pit data value “1” is set on the land 4.
The land pre-pit group C indicating is (1, 1, 1,
1, 1, 1) and the sector synchronization bit is set at the 4th bit position. Therefore, when this land prepit group C is located at a position other than the head of the sector, The case where the land pre-pit group C is detected as a bit array of (1,1,0,1,1,1) in the optical disk device 10 is shown.

That is, here, a detection error occurs due to the lack of the land prepit signal, which should originally exist at the third bit position. And land pre-pit group C
Among them, the number of land prepits excluding the leading sync prepit 5a is 4, and this land prepit number 4 is (N-
Since 1) / 2 = (6-1) /2=2.5 or more, the land prepit data value is determined to be "1". The sector sync bit is detected as "1". Therefore, when EX-OR is performed with the land pre-pit data value "1" and the sector synchronization bit "1", the sector synchronization data value is determined to be "0", whereby the land pre-pit group C has the third bit position. Despite the occurrence of the detection error, the judgment is made with the same value as each value (land pre-pit data value, sector synchronization data value) in the normal state.

Next, in the fourth mode diagram shown in FIG. 14, when the wobble period N of the groove 3 is set to 6 on the optical disc 1, the land pre-pit data value “0” is set on the land 4.
The land pre-pit group D indicating is (1, 0, 0,
(0,0,0) bit arrangement, and since the sector synchronization bit is not set at the fourth bit position, this land pre-pit group D is located at a position other than the beginning of the sector. Land pre-pit group D
In the optical disk device 10 (1,0,0,0,0,1)
It shows a case where an error is detected as the bit array of.

That is, in this case, a false land prepit signal has risen at the 6th bit position, so that a detection error has occurred. Then, the number of land prepits in the land prepit group D excluding the leading sync prepit 5a is 1, and this land prepit number 1 is (N-
Since 1) / 2 = (6-1) /2=2.5 is less than 2.5, the land prepit data value is determined to be "0". The sector sync bit is detected as "0". Therefore, when EX-OR is performed with the land pre-pit data value "0" and the sector synchronization bit "0", the sector synchronization data value is determined to be "0", whereby the land pre-pit group D has the sixth bit position. Despite the occurrence of the detection error, the judgment is made with the same value as each value (land pre-pit data value, sector synchronization data value) in the normal state.

As described above, the land prepit group (L
If the land pre-pits 5 that should be present could not be detected in PPG), or land pre-pits 5 that should not be present
Even if is detected, the land pre-pit data value can be correctly detected.

At this time, the land pre-pit 5 which should be originally
Is detected, a large number of land prepits 5 that should not be originally detected are detected, or a sector synchronization bit is detected, the land prepit data value of the land prepit group (LPPG) is changed. Although it may not be detected correctly, the redundancy at the time of detection can be improved as compared with the case of detecting the land prepit data value by the arrangement of all the land prepits 5 in the land prepit group (LPPG).

Returning to FIG. 6 again, the land pre-pit data detection circuit 24 and the following will be described. As described above, the land pre-pit data detection circuit 24 outputs the land pre-pit data 30a and the sector synchronization data 31a. , To the land pre-pit data decoding circuit 32. Then, the land pre-pit data decoding circuit 3
2, the auxiliary information 32a is detected from the land pre-pit data 30a and the sector synchronization data 31a in accordance with the sector structure and block data format shown in FIGS. 4 and 5, and the auxiliary information 32a is recorded and reproduced by the recording / reproducing circuit 1.
Send to 4. Then, in the recording / reproducing circuit 14, the auxiliary information 3
According to 2a, the recording signal 1 based on the information signal at the time of recording
4a through the laser driving circuit 15 to the optical pickup 1
6, the information signal is recorded in the groove 3 at a predetermined position on the optical disc 1, while the reproduced information signal recorded in the groove 3 on the optical disc 1 is reproduced in accordance with the auxiliary information 32a during reproduction.

Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment. For example, a predetermined position where the land prepits are arranged is abbreviated as a wobble peak (or valley). Although it is set to the peak position, it is naturally possible to set it at a position other than that. Also, for convenience of explanation,
Although the wobble period N = 6 is set as one sync frame, it is naturally possible to set the number of periods other than that. Furthermore, it is determined whether or not the land pre-pit group is the head of the sector by setting the sector synchronization bit position at the fourth bit position as a specific bit position in the sync frame. A specific bit position other than the position may be set.

[0098]

According to the optical disk of the present invention described in detail above, especially when a land prepit group is formed on a land between grooves, the land prepits are located at predetermined positions of the wobble phase of the groove on the land. Formed,
In addition, a land prepit group having N bits for arranging the land prepits in correspondence with the wobble period N (where N is a natural number of 4 or more) is set every other sync frame on the land. At the same time, the land pre-pit group on one land and the land pre-pit group on the adjacent land through the groove for one land are installed with a phase offset by one sync frame from each other. , When the land pre-pit group indicates the land pre-pit data value “1”, the sync pre-pit for synchronizing with the sync frame is arranged at the head bit position, and the land pre-pit is excluded except for the sync pre-pit. Are arranged (N-1) / 2 or more and (N-1) or less, while the land pre-pit group is run. When the pre-pit data value is "0", the sync pre-pit is arranged at the head bit position and less than (N-1) / 2 land pre-pits are arranged excluding the sync pre-pit, so that the wobble is generated. Not all land prepit arrays in the sync frame of cycle N represent the land prepit data value indicated by the land prepit group, but the land prepits other than the sync prepit arranged at the first bit position in the sync frame A sector synchronization bit for representing the land prepit data value indicated by the land prepit group depending on whether or not is arranged, and for synchronizing a specific bit position in the land prepit group with the sector. Since the position is set, the optical disc according to the present invention is applied to the optical disc device. The land pre-pit data value indicated by the land pre-pit groups in the optical disk device can reliably detect, further, it is possible to reliably detect the land prepit groups which are arranged at the start position of the sector.

Further, according to the optical disk device of the present invention, when the land prepit group is detected from the above optical disk, the land prepit data detection circuit detects the sync prepit located at the head of the land prepit group. The land pre-pit data value of the land pre-pit group is determined by the number of land pre-pits removed, so the detection error of the land pre-pit data due to the influence of noise and information signals is reduced, and the land pre-pit group is more accurate. It becomes possible to detect the auxiliary information indicated by. Further, since it is detected whether or not the sector synchronization bit is arranged at a specific bit position excluding the sync prepit, the land prepit group located at the head of the sector can be surely detected.

[Brief description of drawings]

FIG. 1 is a perspective view for explaining an optical disc according to the present invention.

FIG. 2 is a plan view showing a configuration of zones in the optical disc according to the present invention.

FIG. 3 is a diagram schematically showing land prepit groups on lands formed between adjacent grooves in the optical disc according to the present invention.

FIG. 4 is a diagram schematically showing a sector configuration of land pre-pit groups in the optical disc according to the present invention.

FIG. 5 is a diagram showing a format of a land prepit data block in the optical disc according to the present invention.

FIG. 6 is a block diagram showing an optical disk device according to the present invention.

FIG. 7 is an enlarged block diagram showing the inside of the land pre-pit data detection circuit shown in FIG.

FIG. 8 is an enlarged view showing an optical pickup in the optical disc device according to the present invention.

9 is an enlarged view of a photo detector in the optical pickup shown in FIG.

FIG. 10 is a waveform diagram showing waveforms of output signals from each circuit in the optical disc device according to the present invention.

11 is a first mode diagram for explaining the operation of the land pre-pit data detection circuit shown in FIG. 7. FIG.

12 is a second mode diagram for explaining the operation of the land pre-pit data detection circuit shown in FIG. 7. FIG.

13 is a third aspect diagram for explaining the operation of the land pre-pit data detection circuit shown in FIG. 7. FIG.

FIG. 14 is a fourth aspect diagram for explaining the operation of the land prepit data detection circuit shown in FIG. 7.

FIG. 15 is a diagram for explaining an example of a conventional optical disc.

FIG. 16 is a diagram for explaining another example of the conventional optical disc.

FIG. 17 (a) schematically shows a portion of a conventional optical disc in which wobbled grooves have opposite wobble phases, and FIG. 17 (b) shows lands formed on lands adjacent to both sides of one groove. It is the figure which showed typically the part where pre-pits overlap.

[Explanation of symbols]

1 ... Optical disc, 2 ... Disc substrate, 3 ... Groove, 4
... Land, 5 ... Land pre-pit, 5a ... Sync pre-pit, LPPG ... Land pre-pit group, 6 ... Phase change recording layer, 7 ... Metal reflective layer, 10 ... Optical disk device, 1
1 ... Motor drive circuit, 12 ... Spindle motor, 13 ...
Turntable, 14 ... Recording / reproducing circuit, 15 ... Laser drive circuit, 16 ... Optical pickup, 16g ... Photo detector, 17 ... (A + B) circuit, 18 ... (C + D) circuit, 19 ... (A + B + C + D) circuit, 20 ... { (A +
B)-(C + D)} circuit (= radial push-pull signal generation circuit), 20a ... Radial push-pull signal, 21
... wobble signal detection circuit, 21a ... wobble signal, 22
... Land pre-pit signal detection circuit, 22a ... Land pre-pit signal, 23 ... Wobble clock generation circuit, 23a
... wobble clock, 24 ... Land pre-pit data detection circuit, 25 ... AND circuit (AND circuit), 26 ... Land pre-pit gate signal generation circuit, 27 ... Land pre-pit counter, 28 ... Counter enable signal generation circuit, 29 ... Sector synchronization bit detection circuit, 30 ... Land pre-pit data determination circuit, 30a ... Land pre-pit data, 31 ... EX-OR circuit (exclusive OR circuit), 3
1a ... Sector synchronization data, 32 ... Land pre-pit data decoding circuit, 32a ... Auxiliary information, B ... Beam spot.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G11B 20/10 321 G11B 20/10 321Z 20/12 20/12 F term (reference) 5D029 WA02 WA30 WD16 5D044 BC04 CC04 DE38 DE57 DE77 FG16 FG18 GM04 GM11 GM21 5D090 AA01 BB04 CC04 CC14 DD01 DD05 EE13 FF07 FF45 GG03 GG26 GG28 GG38

Claims (4)

[Claims] 1. A track in which a groove wobbling in a sine wave shape (or a cosine wave shape) and a land located between the adjacent grooves are paired is arranged from the innermost circumference to the outermost circumference on a disk substrate. Auxiliary information, which is formed in a spiral shape or a concentric shape, is preliminarily formed as land prepits on the land to record and / or reproduce the information signal in the groove, and the auxiliary information is added to the information signal. The recording area of is divided into multiple zones in the radial direction,
The optical disk is such that the number of rotations is gradually changed to a substantially constant linear velocity for each zone, and the angular velocity is controlled to be constant at a number of rotations set for each zone in each zone. The wobble phase is always formed in the same phase in each zone, and one sync frame is formed with a wobble period N (where N is a natural number of 4 or more), and a sector is composed of a predetermined number of sync frames. The land prepits are formed on the land at a predetermined position of the wobble phase of the groove, and the number of N bits corresponds to the wobble period N for arranging the land prepits. The land pre-pit group having the above is installed every other sync frame on the land, and the land pre-pit group on the one land is And a land pre-pit group on the land that is adjacent to one of the lands via the groove are provided with a phase difference of one sync frame from each other. When the pit data value is "1", a sync pre-pit for synchronizing with the sync frame is arranged at the head bit position, and the land pre-pit is (N-1) except for the sync pre-pit. ) / 2 or more and (N-
1) No more than one are arranged, while when the land pre-pit group indicates a land pre-pit data value "0",
An optical disc, wherein the sync prepits are arranged at the head bit position, and less than (N-1) / 2 of the land prepits are arranged excluding the sync prepits. 2. The optical disc according to claim 1, wherein the land prepit group arranged at the head position of the sector synchronizes a specific bit position excluding the sync prepit with the sector. Sector sync bit position and the land pre-pit data value "1" is set, the sector sync bit is not placed, while the land pre-pit data value "0" is set, the sector sync bit is placed. An optical disc characterized by. 3. The optical disc according to claim 1, wherein the track on the optical disc is irradiated with a beam spot emitted from an optical pickup, and the reflected light reflected from the track is picked up by the optical pickup. An optical disk device configured to detect a wobble signal corresponding to the wobble of the track and to detect each land prepit signal of the land prepit group on the land by photoelectrically converting by a photo detector in The photo detector is divided into an outer peripheral side and an inner peripheral side along the track, and the difference between the optical sensor output on the outer peripheral side and the optical sensor output on the inner peripheral side is calculated to perform radial push pull. A radial push-pull signal generation circuit for outputting a signal, and detecting the wobble signal from the radial push-pull signal. A wobble signal detection circuit for generating a wobble clock from the wobble signal, and a land pre-pit signal detection circuit for detecting each land pre-pit signal of the land pre-pit group from the radial push-pull signal. Based on the wobble clock and each land prepit signal of the land prepit group, the number of land prepits is (N-1) / 2 excluding the sync prepit located at the head of the land prepit group. If the number of data is equal to or more than (N-1), the land prepit data value is determined to be "1", while the land prepits are excluded except for the sync prepit located at the head of the land prepit group. If the number is less than (N-1) / 2, the land pre-pit data value is "0". Optical disc apparatus being characterized in that a certain and determining the land pre-pit data detection circuit. 4. The optical disk device according to claim 3, wherein the land prepit data detection circuit has a sector synchronization bit arranged at a specific bit position excluding the sync prepit in the land prepit group. If the land prepit data value indicated by the land prepit group is "1" and the sector synchronization bit is not arranged, and if the land prepit data value indicated by the land prepit group is An optical disk device characterized in that when it is "0" and the sector synchronization bit is arranged, it is determined to be the land pre-pit group arranged at the head position of a sector.