JP2003091829A - Optical disk and optical disk device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely detect the auxiliary information shown by 1st and 2nd land prepit groups. SOLUTION: The optical disk is constituted of two forms such as the 1st land prepit group having the number of bits of N pieces for arranging the land prepit corresponding to a wobble period N (wherein, N is natural number >=4) to show values of the land prepit data for representing the auxiliary information and the 2nd land prepit group having the number of bits of N pieces for arranging the land prepit corresponding to the wobble period N to show values of sector synchronizing data for representing the information on the landing position of the sector, and also in this provided optical disk, the 1st land prepit group and the 2nd lane prepit group are made to be a pair, and this pair is arranged every other one sync frame on the lands adjacent each other through a groove in the same sync frame.

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 cycle N (where N is a natural number of 4 or more), and a sector is composed of a predetermined number of sync frames. Corresponding to the cycle N, the first land prepit group having N number of bits for arranging land prepits and indicating the land prepit data value for representing the auxiliary information, and corresponding to the wobble cycle N. A second land pre-pit group having a number of N bits for land pre-pit arrangement and indicating a sector synchronization data value for indicating the head position information of the sector, and the second land pre-pit group. One land prepit group and the second land prepit group are paired, and the pair are adjacent to each other via the groove in the same sync frame. Every other sync frame, and each land prepit of the first land prepit group and each land prepit of the second land prepit group are wobbles of the groove in the same sync frame. On the other hand, the optical disc is characterized in that the optical discs are arranged at predetermined positions with different phases.

A second invention is the optical disc of the first invention, wherein when the first land prepit group has a land prepit data value "1",
Sync pre-pits for synchronizing with the sync frame are arranged at the head bit positions, and the land pre-pits are arranged at (N-1) bit positions except the sync pre-pits. On the other hand, when the first land prepit group shows the land prepit data value "0", only the sync prepit is arranged at the head bit position, and the second land prepit group has the sector synchronization data value "1". , The land prepits are arranged in each of the (N-1) bit positions except the first bit position, while when the second land prepit group shows the sector synchronization data value "0", The optical disc is characterized in that the land prepits are not arranged at all bit positions.

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 each land of the first and second land prepit groups is detected from above the land. An optical disk device configured to detect a pre-pit signal, wherein the photo detector is divided into an outer peripheral side and an inner peripheral side along the track, and an optical sensor output on the outer peripheral side and an inner peripheral side light are detected. A radial push-pull signal generation circuit that calculates a difference from the sensor output and outputs a radial push-pull signal; A wobble signal detection circuit for detecting the wobble signal from the in issue, the wobble clock generation circuit for generating a wobble clock from the wobble signal,
A land prepit signal detection circuit for detecting each land prepit signal of the first and second land prepit groups from the radial push-pull signal, the wobble clock, and the first and second land prepit groups. A land prepit data detection circuit that determines the land prepit data value indicated by the first land prepit group and the sector synchronization data value indicated by the second land prepit group based on each land prepit signal; It is an optical disk device characterized by comprising:

A fourth invention is the optical disc device according to the third invention, wherein the land prepit data detection circuit removes the land prepits from the land except the sync prepits. When the number of pre-pits is (N-1) / 2 or more and (N-1) or less, it is determined that the land pre-pit data value is "1", while the land pre-pits are excluded except for the sync pre-pits. When the number of pits is less than (N-1) / 2, it is determined that the land prepit data value is "0", and the land prepits are removed from the second land prepit group except for the head bit position. The number is (N-1) / 2 or more and (N-
1) The sector synchronization data value is determined to be "1" when the number is less than or equal to 1, and the sector synchronization data value is determined when the number of land prepits is less than (N-1) / 2 except the first bit position. Is an optical disc device.

[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, in each suitable one zone on the optical disk 1, a diagram centering on each land prepit 5 of the first and second land prepit groups (first and second LPPG) formed on the land 4 is shown. This will be described with reference to FIGS.

FIG. 3 shows an optical disc according to the present invention.
FIG. 4 is a diagram schematically showing first and second land prepit groups on a land formed between adjacent grooves. FIG. 4 shows a sector structure of the first and second land prepit groups in the optical disc according to the present invention. Schematic diagram,
FIG. 5 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 in a sine wave shape (or a cosine wave shape).

Further, one wobble period N of the groove 3 (where N is a natural number of 4 or more) constitutes one sync frame.

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-pits 5 formed on the lands 4 have the adjacent grooves 3- and 3-.
, 3- and 3-3 are connected to each other.

The land prepits 5 are a first land prepit group (first LPPG) formed on the land 4 in sync frame units, and a second land prepit group formed on the land 4 in sync frame units. (First LPPG).

The first land pre-pit group (first LPPG) has N number of bits for land pre-pit arrangement corresponding to the wobble period N, and the information signal is sent to the groove 3 on the optical disc 1. It shows a land pre-pit data value for indicating auxiliary information including a zone address and an ECC address for recording and / or reproducing the data. For example, the land pre-pit group A1 and the land pre-pit group A2 are shown in the figure. , Land pre-pit group A3 belongs to the first land pre-pit group.

On the other hand, the second land prepit group (second LPPG) has N bit numbers for land prepit arrangement corresponding to the wobble period N, and is composed of 26 sync frames. It shows a sector synchronization data value for indicating sector start position information. For example, in the figure, the land prepit group B1, the land prepit group B2, and the land prepit group B3 belong to the second land prepit group. ing.

Further, the first land pre-pit group and the second land pre-pit group are paired, and this pair forms one sync frame on the lands 4 and 4 adjacent to each other via the groove 3 in the same sync frame. The land pre-pits 5 of the first land pre-pit group (first LPPG) and the land pre-pits 5 of the second land pre-pit group (second LPPG), which are installed every other space and are in the same sync frame, form the groove 3. The phases of the wobbles are different from each other, and the wobbles are arranged at predetermined positions.

Specifically, each land prepit 5 of the first land prepit group (first LPPG) is arranged so as to be contiguous to the peak position of the peak of the wobble waveform of one groove 3, while the second land prepit 5 is formed. Since each land prepit 5 of the land prepit group (second LPPG) is connected to the substantially peak position of the valley of the wobble waveform of the same groove 3 as described above, both of them are in the same wobble of the groove 3. On the other hand, they are arranged approximately 180 ° out of phase with each other. Therefore, the first land pre-pit group (first
LPPG) and the second land pre-pit group (second L
In the same one sync frame, (P1, PPG) is (A1,
B1) and a pair as in (A3, B3) in one other sync frame and arranged in alternate sync frames along the circumferential direction of the optical disc 1. There is.

Further, in the sync frames between every other sync frames on the same land 4 and 4, the polarity is inverted with respect to the first and second land pre-pit groups of the preceding and following sync frames, and the first and second sync frames are reversed. , The second land pre-pit group is arranged.

That is, in the sync frame S1, the land 4
-Auxiliary information to the groove 3 is formed by a pair of the land pre-pit group A1 of the first land pre-pit group formed above and the land pre-pit group B1 of the second land pre-pit group formed above the land 4-. In the sync frame S2, the land prepit group B2 of the second land prepit group formed on the land 4-corresponds to the upper groove 3 (not shown), and the land 4 is detected. -The land pre-pit group A2 of the first land pre-pit group formed above corresponds to the lower groove 3 (not shown),
Further, in the sync frame S3, a pair of the land prepit group A3 of the first land prepit group formed on the land 4-and the land prepit group B3 of the second land prepit group formed on the land 4-is paired. Corresponds to the detection of auxiliary information to the groove 3-.

The first land prepit group (first LPPG) A1 to A3 described above is always provided with a sync prepit 5a for synchronizing with the sync frame at the head bit position.

When the first land prepit group (first LPPG) indicates the land prepit data value "1", the sync prepit 5 is located at the first bit position in the sync frame as in the land prepit group A1.
a is arranged, and land prepits 5 are provided at all (N-1) bit positions except sync prepit 5a.
When the first land pre-pit group (first LPPG) shows the land pre-pit data value “0”, the sync pre-pit 5 is only present in the first bit position in the sync frame like the land pre-pit group A3.
a is arranged.

At this time, in the sync frame having the wobble cycle N, when N = 6 is set, for example, the land prepit group A1 showing the land prepit data value "1" is (1, 1, 1, 1, 1). , 1), and the land prepit group A3 indicating the land prepit data value “0” is (1, 0, 0, 0, 0,
0) bit array.

The second land prepit groups (second LPPG) B1 to B3 described above do not have the sync prepit 5a in common at the head bit position. And the 2nd land pre-pit group (2nd LPPG)
Is located at the beginning position of the sector and indicates the sector synchronization data value “1”, except for the beginning bit position in the sync frame as in the land pre-pit group B1 (N
-1) The land pre-pits 5 are arranged at all of the respective bit positions, while the second land pre-pit group (second L
When the PPG) is located at a position other than the head position of the sector and indicates the sector synchronization data value “0”, the land prepits 5 are not arranged at all the bit positions in the sync frame like the land prepit group B3.

At this time, in the sync frame of wobble period N, for example, when N = 6 is set, the land pre-pit group B1 showing the sector synchronization data value "1" is (0, 1, 1, 1, 1, 1), while the land pre-pit group B3 indicating the sector synchronization data value "0" has a bit arrangement of (0,0,0,0,0,0).

Although the above-mentioned second land pre-pit group (second LPPG) is not provided with the sync pre-pits 5a for identifying the sync frame, in the present invention, the sync frames adjacent in the radial direction are circled. Since it is always divided in the same phase with respect to the direction, the sync prepit 5a arranged at the head bit position in the first land prepit group (first LPPG) paired with this second land prepit group (second LPPG). If the sync frame is identified by, the sync frame in which the second land prepit group is arranged can also be identified, so there is no particular problem. However, the sync prepit 5a may be arranged in the second land prepit group,
In this case, the polarities are detected by the first land pre-pit group at the peak position of the peak of the wobble waveform of the groove 3 and the second land pre-pit group at the peak position of the valley of the wobble waveform of the groove 3. For example, it is possible to improve the accuracy of identifying sync frames.

As described above, since the first pre-pit group (first LPPG) is arranged in every other sync frame, when one sector is composed of 26 sync frames, it is arranged in one sector. The number of first land pre-pit groups is 13. Further, since the first land prepit group shows the land prepit data value, the data per sector is 13 bits. Further, when one ECC block is composed of 32 sectors, the Land Pre-Pit Data shown in FIG.
Auxiliary information such as zone address and ECC block address is represented as in the a Block format example.

The above-mentioned sector structure and block data format are examples, and other sector structures and block data formats may be used.

Then, in the optical disc 1 according to the present invention,
All land prepit arrays in the sync frame of wobble period N (where N is a natural number of 4 or more) do not represent the land prepit data value and the sector synchronization data value, but the first and second land prepits. Groove (first, second
Sync pre-pit 5a at the first bit position in LPPG)
It is possible to discriminate both land prepit grooves by the presence or absence of them and the polarity and phase of the first and second land prepit grooves, and the land prepit data can be identified by the first land prepit group (first LPPG). The second land pre-pit group (second L
Since the sector synchronization data value is represented by PPG), when the optical disc 1 according to the present invention is applied to the optical disc device 10 (FIG. 6) according to the present invention, which will be described later, the first land pre-recording is performed in the optical disc device 10. Pit group (1st L
The land pre-pit data value indicated by PPG can be reliably detected, and further, the second land pre-pit group (second LP
It is possible to reliably detect the sector synchronization data value indicated by (PG).

<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 configured to record and / or reproduce information signals 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 by the motor drive signal 11a from the motor drive circuit 11 via the spindle motor 12. 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 be opposed to the optical disc 1 so as to be 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 into a beam splitter 16a.
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 enlargedly shown 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 disk substrate 2 of the optical disk 1
A wobble signal and each land pre-pit signal in the first and second land pre-pit groups are detected from a track in which a groove 3 and a land 4 wobbled in a sine wave shape (or a cosine wave shape) are combined. In doing so, the laser power is switched in the laser drive circuit 15 at the time of recording on the optical disc 1 and at the time of reproduction, and the laser drive signal 15a for obtaining a strong laser power at the time of recording is supplied to the semiconductor laser 16b in the optical pickup 16.
(FIG. 8), on the other hand, a laser drive signal 15a that provides a weak laser power during reproduction is supplied to the semiconductor laser 16b (FIG. 8) in the optical pickup 16.

Then, when the beam spot B emitted from the optical pickup 16 is applied to the track on the optical disc 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 inner photosensor C and the photosensor D as the inner photosensor 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 photo detector 16g (FIGS. 8 and 9) in the optical pickup 16 uses the (A + B + C + D) circuit for the A to D current signals having a current value proportional to the amount 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 is used to obtain the radial push-pull signal 20a, and the wobble signal and each land pre-pit signal in the first and second land pre-pit groups are obtained as shown in FIG. 10 (a). The radial push-pull signal 20a having the included waveform 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, and the wobble signal 21a is obtained. The wobble signal 21a having a waveform as shown in () is sent to the wobble clock generation circuit 23.

Next, in the wobble clock generation circuit 23, 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 (e) is supplied to the land prepit 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 the first land prepit signal 22a and the second land prepit signal 22a by each land prepit 5 in the first land prepit group (first LPPG) formed on the land 4 of the optical disc 1.
Second land prepit signal 22b by each land prepit 5 in the land prepit group (second LPPG)
Is to detect. In the land pre-pit signal detection circuit 22, the radial push-pull signal 20a from the {(A + B)-(C + D)} circuit 20 is binarized by the first and second threshold values, and the first and second lands are formed. Obtaining the pre-pit signals 22a and 22b, the first land pre-pit signal 22a having the waveform as shown in FIG. 10B and the second land pre-pit signal 22b having the waveform as shown in FIG. 10C are obtained. The data is sent to the land pre-pit data detection circuit 24. At this time, in the radial push-pull signal 20a shown in FIG. 10A, the first and second land pre-pit signals 22a and 22b are signal components having different polarities, that is, positive polarity and negative polarity, respectively, and wobble. Since the phases of the waveforms are different, they can be detected separately.

That is, in the radial push-pull signal 20a shown in FIG. 10A, the positive first land pre-pit signal 22a and the groove 3 at the peak position of the peak of the wobble waveform of the groove 3 in the sync frame S4. The second land pre-pit signal 22b having the negative polarity is detected at the substantially peak position of the valley of the wobble waveform, and the first land pre-pit having the negative polarity at the substantially peak position of the crest of the wobble waveform of the groove 3 in the adjacent sync frame S5. The second land pre-pit signal 22b having the positive polarity is detected at the substantially peak position of the signal 22a and the valley of the wobble waveform of the groove 3, and the positive polarity is further obtained at the substantially peak position of the crest of the wobble waveform of the groove 3 in the adjacent sync frame S6. The first land pre-pit signal 22a and the second land pre-signal having no signal on the valley side of the wobble waveform of the groove 3. Tsu DOO signal 22b is detected.

As described above, in the sync frame S5, although the first land prepit group and the second land prepit group corresponding to the adjacent groove 3 are also detected, the first and second lands detected here are detected. First and second land pre-pit signals 22a, 2 of the pre-pit group
2b has a polarity and a phase different from those of the sync frame S4 and the sync frame S6.
7a and the second gate signal 27b can be easily removed.

Next, the land pre-pit data detection circuit 2
4 is the first and the first from the land pre-pit signal detection circuit 22.
Using the second land pre-pit signals 22a and 22b and the wobble clock 23a from the wobble clock generation circuit 23, the first land pre-pit group (first LPP)
The land pre-pit data value indicated by G) and the sector synchronization data indicated by the second land pre-pit group (second LPPG) are determined.

Here, the internal structure of the land pre-pit data detection circuit 24 will be described with reference to FIG. 7. The land pre-pit data detection circuit 24 is the first AN.
D circuit (logical product circuit) 25, second AND circuit (logical product circuit) 26, land pre-pit gate signal generation circuit 2
7, a counter enable signal generation circuit 28, a first land prepit counter 29, a second land prepit counter 30, and a land prepit data determination circuit 31.
And a sector synchronization data determination circuit 32.

In the land prepit data detection circuit 24 described above, the land prepit signal detection circuit 22
The first land pre-pit signal 22a detected in (FIG. 6) is input to the first AND circuit 25, and the second land pre-pit signal 22b is input to the second AND circuit 26.

The wobble clock 23a generated by the wobble clock generation circuit 23 (FIG. 6) is used as the land prepit gate signal generation circuit 27, the counter enable signal generation circuit 28, and the land prepit data determination circuit 3.
1, sector synchronization data determination circuit 32, respectively.

Further, in the land pre-pit gate signal generation circuit 27 described above, based on the wobble clock 23a input here, as shown in FIG. 10 (f), it is located at the approximate peak position of the peak of the wobble waveform. The first gate signal 27a having a pulse width narrow enough to extract only the correct first land pre-pit signal 22a is generated, and the first gate signal 27a is generated.
While the gate signal 27a is input to the first AND circuit 25, the gate signal 27a is input based on the wobble clock 23a.
As shown in (g), the correct second land pre-pit signal 22b located at the substantially peak position of the valley of the wobble waveform.
A second gate signal 27b having a pulse width narrow enough to extract only the second gate signal 27b is generated.
It is input to the ND circuit 26.

Next, in the above-mentioned first AND circuit (logical product circuit) 25, the first land pre-pit signal 22a and the first land pre-pit signal 22a
A logical product with the gate signal 27a is calculated, and a post-gate first land pre-pit signal 25a having a waveform as shown in FIG. 10 (h) is obtained from the calculation result, and the post-gate first land pre-pit signal 25a is obtained. Are sent to the counter enable signal generation circuit 28 and the first land pre-pit counter 29, respectively. On the other hand, in the second AND circuit (logical product circuit) 26 described above, the second land pre-pit signal 2
2b and the second gate signal 27b are ANDed, and the gated second land pre-pit signal 26a having a waveform as shown in FIG. The pre-pit signal 26a is sent to the second land pre-pit counter 30.

At this time, the first AND circuit 25 and the second AN
The D circuit 26 removes the false land prepit signal included in the first land prepit group (first LPPG) and the second land prepit group (second LPPG) due to noise or the like, or as described above. This is for removing the land pre-pit signal corresponding to the groove 3 to be formed, which is an unexpected timing, that is, the first
Although the first land pre-pit signal 22a and the second land pre-pit signal 22b existing outside the ranges of the gate signal 27a and the second gate signal 27b are not detected as false land pre-pit signals, they are not detected. The false land pre-pit signal generated within the range of the gate signal 27a and the first gate signal 27b is detected as it is.

Next, in the counter enable signal generation circuit 28 described above, the wobble clock 2 input here is input.
When the sync prepit 5a is detected in the post-gate first land prepit signal 27a using 3a and the post-gate first land prepit signal 25a, the wobble period N of the groove 3 is set to 6 as described above. At this time, 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 sync pre-pit 5a is generated as shown in FIG. The counter enable signal 28a is sent to the first land prepit counter 29, the second land prepit counter 30, the land prepit data determination circuit 31, and the sector synchronization data determination circuit 32, respectively.

Next, in the above-described first land prepit counter 29, the number of land prepits of the post-gate first land prepit signal 25a, except for the sync prepit 5a, is maintained for the period in which the counter enable signal 28a is HIGH. 10K, the counted first land prepit count value 29a is sent to the land prepit data determination circuit 30. At this time, by the operation of the first land pre-pit counter 29, not only the post-gate first land pre-pit signal 25a located at the substantially peak position of the peak of the wobble waveform but also within the range of the first gate signal 27a. The generated false land pre-pit signal is also counted, and further, the state where it is located at substantially the peak position of the peak of the wobble waveform but cannot be detected as the post-gate first land pre-pit signal 25a is also counted.

On the other hand, in the second land pre-pit counter 30 described above, the number of land pre-pits of the post-gate second land pre-pit signal 26a input here is calculated as shown in FIG. 10 over the period in which the counter enable signal 28a is HIGH.
The second land pre-pit count value 30a is counted as shown in (l) and the counted value of the second land pre-pit count value 30a
2 is being sent.

Next, in the land prepit data determination circuit 31 described above, the first land prepit count value 29a is latched at the trailing edge of the counter enable signal 28a input here. In addition, the wobble clock 23 after the count enable signal 28a falls
A reset signal 31b for resetting the first land prepit count value 29a of the first land prepit counter 29 is sent to the first land prepit counter 29 at the rising timing of a.

In the land pre-pit data determination circuit 31, when the wobble period N of the groove 3 is set to 6, the first land pre-pit count value 29a excluding the sync pre-pit 5a, that is, one 1st land pre-pit group (1st land) corresponding to sync frame
If the number of land prepits other than the sync prepit 5a is (N-1) / 2 = (6-1) / 2 or more in LPPG), the first land prepit group (first LPP)
It is determined that the land pre-pit data value indicated by G) is "1", and "1" is set as the land pre-pit data 31a as shown in FIG. 10 (m) to the land pre-pit data decoding circuit 33 (FIG. 6). Is output to.

On the other hand, the first land prepit count value 29a excluding the sync prepit 5a is (N-
1) / 2 = (6-1) / 2, it is determined that the land prepit data value indicated by the first land prepit group (first LPPG) is “0”, and the land prepit data 31a is determined. "0" is output to the land pre-pit data decoding circuit 33 (FIG. 6).

Next, the sector synchronization data determination circuit 32 latches the second land pre-pit count value 30a at the trailing edge of the counter enable signal 28a input here. Also, the count enable signal 28a
A reset signal 32b for resetting the second land prepit count value 30a of the second land prepit counter 30 is sent to the second land prepit counter 30 at the rising timing of the wobble clock 23a after There is.

Then, in the sector synchronization data determination circuit 32, when the wobble period N of the groove 3 is set to 6,
The second land pre-pit count value 30a excluding the leading bit position, that is, the land of the second land pre-pit group (second LPPG) in the same one sync frame as the first land pre-pit group (first LPPG) If the number of pre-pits is (N-1) / 2 = (6-1) / 2 or more, the second land pre-pit group (second LP
PG) indicates that the sector synchronization data value is “1”, and as shown in FIG.
"1" as a is the land pre-pit data decoding circuit 33
(Fig. 6).

On the other hand, the second land pre-pit count value 30a excluding the leading bit position is (N-1) / 2.
= (6-1) / 2, it is determined that the land prepit data value indicated by the second land prepit group (second LPPG) is "0", and the land prepit data 32a is "0". Is output to the land pre-pit data decoding circuit 33 (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 on the optical disc 1 is set to 6, the first land prepit for expressing the land prepit data value as the auxiliary information. Belong to a group and
The land prepit group A1 indicating the land prepit data value “1” on the land 4 is (1, 1, 1, 1, 1,
In the case where the land pre-pit group A1 is formed with the bit arrangement of 1), the land pre-pit group A1 is mistakenly detected as the bit arrangement of (1, 1, 1, 0, 1, 1) in the optical disc device 10. There is.

That is, here, a detection error occurs due to the lack of the land prepit signal, which should originally exist at the fourth bit position. And land pre-pit group A
The number of land prepits excluding the first sync prepit 5a in 1 is 4, and the number of land prepits 4 is (N-
Since 1) / 2 = (6-1) /2=2.5 or more, the land prepit data value is determined to be "1". As a result, the land pre-pit group A1 is determined to have the same value as the land pre-pit data value in the normal state, although a detection error has occurred in the fourth bit position.

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 disc 1, the first land pre-pit for expressing the land pre-pit data value as auxiliary information. Belongs to the pit group, and
The land prepit group A3 indicating the land prepit data value “0” on the land 4 is (1, 0, 0, 0, 0,
In the case where the land prepit group A3 is formed in the bit array of (0), the land pre-pit group A3 is detected as an error in the bit array of (1,0,1,0,0,0) in the optical disk device 10. There is.

That is, here, a false land pre-pit has stood up at the third bit position, so that a detection error has occurred. And land pre-pit group A3
The number of land prepits excluding the leading sync prepit 5a is 1 and the number of land prepits 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". As a result, the land pre-pit group A3 is determined to have the same value as the land pre-pit data value in the normal state, although a detection error has occurred at the third bit position.

Next, in the third mode diagram shown in FIG. 13, when the wobble period N of the groove 3 on the optical disc 1 is set to 6, the second position for indicating the sector synchronization data value as the sector start position information. Belongs to the Land Pre-Pit group,
Moreover, the land pre-pit group B1 indicating the sector synchronization data value “1” on the land 4 is (0, 1, 1, 1, 1,
In the case where the land pre-pit group B1 is formed in the bit arrangement of 1), the land pre-pit group B1 is detected as a bit arrangement of (0, 1, 1, 0, 1, 1) in the optical disk device 10 by mistake. There is.

That is, here, a detection error occurs due to the lack of the land prepit signal, which should originally exist at the fourth bit position. And land pre-pit group B
The number of land pre-pits excluding the first bit position in 1 is 4, and the number of land pre-pits 4 is (N-1) / 2 =
Since it is larger than (6-1) /2=2.5, the sector synchronization data value is determined to be "1". As a result, the land pre-pit group B1 is judged to have the same value as the sector synchronization data value in the normal state, although a detection error has occurred at the fourth bit position.

Next, in the fourth mode diagram shown in FIG. 14, when the wobble period N of the groove 3 on the optical disc 1 is set to 6, the second position for indicating the sector synchronization data value as the sector head position information. Belongs to the Land Pre-Pit group,
In addition, the land pre-pit group B3 indicating the sector synchronization data value “0” on the land 4 is (0, 0, 0, 0, 0,
In the case where the land pre-pit group B3 is formed as the bit array of (0), the land pre-pit group B3 is detected as a bit array of (0,0,0,0,0,1) in the optical disk device 10 by mistake. There is.

That is, in this case, a false land prepit has stood up at the sixth bit position, so a detection error has occurred. And land pre-pit group B3
Among them, the number of land prepits excluding the head bit position is 1, and this land prepit number 1 is (N-1) / 2 = (6
Since it is smaller than -1) /2=2.5, the sector synchronization data value is determined to be "0". As a result, the land pre-pit group B3 is determined to have the same value as the sector synchronization data value in the normal state, although a detection error has occurred in the sixth bit position.

As described above, the operation of the land prepit data detection circuit 24 fails to detect the original land prepit 5 in the first and second land prepit groups (first and second LPPG), or Even if the land pre-pit 5 which should not be originally detected is detected,
It is possible to correctly detect the land pre-pit data value and the sector synchronization data value.

At this time, the land pre-pit 5 which should be originally
Is detected or a large number of land prepits 5 which should not be originally detected are detected, the land prepit data value of the first land prepit group (first LPPG) and the second land prepit group (second 2 LPP
Although the sector synchronization data value of G) may not be detected correctly, the redundancy at the time of detection is more than that when the land prepit data value is detected by the arrangement of all the land prepits 5 in the land prepit group (LPPG). Can be improved.

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 31a and the sector synchronization data 32a. , To the land pre-pit data decoding circuit 33. Then, the land pre-pit data decoding circuit 3
3, the auxiliary information 33a is detected from the land pre-pit data 31a and the sector synchronization data 32a, for example, according to the sector configuration and block data format shown in FIGS. 4 and 5, and the auxiliary information 33a 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 3a, the recording signal 1 based on the information signal during 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 33a 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 a peak position of a wobble peak and a valley. However, it is of course possible to set it at other positions. Further, for convenience of explanation, the wobble cycle N = 6 is set to one sync frame, but it is naturally possible to set it to a cycle number other than that.

[0104]

In the optical disc and the optical disc apparatus according to the present invention described in detail above, according to the optical disc of the first aspect, particularly when the land prepit group is formed on the land between the grooves, the wobble period N (however, ,
N is a natural number of 4 or more) and has N bit numbers for arranging land prepits, and a first land prepit group indicating a land prepit data value for indicating auxiliary information, and a wobble period N. And a second land pre-pit group having a number of N bits for land pre-pit arrangement and showing a sector synchronization data value for indicating the start position information of the sector, and The first land pre-pit group and the second land pre-pit group are paired, and the pair is installed in every other sync frame on lands adjacent to each other through a groove in the same sync frame, and the same sync frame. Each land prepit in the 1st land prepit group and each land prepit in the 2nd land prepit group become wobbles in the groove. To to each Chigae phase it is disposed at a predetermined position, the first land prepit groups for auxiliary information to the information signal, a second for sector synchronization
The land pre-pit group can be reliably detected.

According to the optical disc of the second aspect, when the first land prepit group indicates the land prepit data value "1", the sync prepit for synchronizing with the sync frame at the head bit position. Are arranged and except for the sync pre-pit (N-
1) Land pre-pits are placed at each bit position,
On the other hand, when the first land pre-pit group shows the land pre-pit data value "0", only the sync pre-pit is arranged at the head bit position, and when the second land pre-pit group shows the sector synchronization data value "1". , The land pre-pits are arranged at each of the (N-1) bit positions except the first bit position, and when the second land pre-pit group shows the sector synchronization data value "0", all the bit positions are Since the land prepits are not arranged, when this optical disc is applied to the optical disc device, the land prepit data value of the first land prepit group and the sector synchronization data value of the second land prepit group in the optical disc device. Can be reliably determined.

According to the optical disk device of the third aspect, when the first and second land prepit groups are detected from the above optical disk, the first land prepit group is detected by the land prepit data detection circuit. The land pre-pit data value shown and the sector synchronization data value shown by the second land pre-pit group can be reliably determined.

According to the optical disc apparatus of the fourth aspect, the land prepit data detection circuit has a land prepit number of (N-1) / 2 excluding sync prepits for the first land prepit group. Or more and (N-
1) Land pre-pit data value is “1” when the number is 1 or less
On the other hand, when the number of land prepits is less than (N-1) / 2 except the sync prepits, it is determined that the land prepit data value is "0".
The sector synchronization data value is "1" when the number of land prepits is (N-1) / 2 or more and (N-1) or less for the second land prepit group except for the head bit position. On the other hand, when the number of land prepits is less than (N-1) / 2 except the first bit position, it is determined that the sector synchronization data value is "0".
When determining the land pre-pit data value of the first land pre-pit group and the sector synchronization data value of the second land pre-pit group, the detection error of the first and second land pre-pit data due to the influence of noise and information signal is reduced. Then
It is possible to make a more accurate determination.

[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 first and second land prepit groups on a land formed between adjacent grooves in the optical disc according to the present invention.

FIG. 4 is a diagram showing the first and second optical discs according to the present invention.
It is the figure which showed typically the sector structure by a land pre-pit group.

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, 6 ... Phase change recording layer, 7 ... Metal reflective layer, A1 to A3
… 1st land pre-pit group (1st LPPG), B
1-B3 ... 2nd land pre-pit group (2nd LPP
G), 10 ... Optical disk device, 11 ... Motor drive circuit,
12 ... Spindle motor, 13 ... Turntable, 14
... recording / reproducing circuit, 15 ... laser driving 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 ... First land pre-pit signal, 22
b ... Second land pre-pit signal, 23 ... Wobble clock generation circuit, 23a ... Wobble clock, 24 ... Land pre-pit data detection circuit, 25 ... First AND circuit (logical product circuit), 26 ... Second AND circuit (logical product circuit) ),
27 ... Land pre-pit gate signal generation circuit, 28 ... Counter enable signal generation circuit, 29 ... First land pre-pit counter, 30 ... Second land pre-pit counter, 31 ... Land pre-pit data determination circuit, 31a ...
Land pre-pit data, 32 ... Sector synchronization data determination circuit, 32a ... Sector synchronization data, 33 ... Land pre-pit data decoding circuit, 33a ... Auxiliary information, B ... Beam spot.

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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. A first land prepit group having N number of bits for arranging land prepits corresponding to the wobble period N and showing a land prepit data value for representing the auxiliary information; A second run having a number of N bits for arranging land pre-pits corresponding to the wobble period N and showing a sector synchronization data value for representing the start position information of the sector. It consists of two forms of the pre-pit group, and,
The first land pre-pit group and the second land pre-pit group are paired, and the pairs are installed every other sync frame on lands adjacent to each other through the groove in the same sync frame, and Within the same sync frame, each land pre-pit of the first land pre-pit group and each land pre-pit of the second land pre-pit group are arranged at predetermined positions with different phases with respect to the wobble of the groove. An optical disc characterized by being recorded. 2. The optical disc according to claim 1, wherein when the first land pre-pit group indicates a land pre-pit data value “1”, a sync pre-sync for synchronizing with the sync frame at a head bit position. Pits are arranged and the land pre-pits are arranged at each of (N-1) bit positions except the sync pre-pits, while the first land pre-pit group has a land pre-pit data value "0". When the second land prepit group has a sector synchronization data value of "1", only the sync prepits are arranged at the head bit position.
1) The land prepits are arranged at each of the bit positions, while when the second land prepit group shows the sector synchronization data value "0", the land prepits are not arranged at all the bit positions. 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. A photoelectric detector is used to perform photoelectric conversion to detect a wobble signal corresponding to the wobble of the track, and to detect each land prepit signal of the first and second land prepit groups on the land. The optical detector configured as described above, wherein the photo detector is divided into an outer peripheral side and an inner peripheral side along the track, and a difference between an outer peripheral side optical sensor output and an inner peripheral side optical sensor output is calculated. A radial push-pull signal generating circuit for outputting a radial push-pull signal, and the wob from the radial push-pull signal. A wobble signal detection circuit for detecting a signal; a wobble clock generation circuit for generating a wobble clock from the wobble signal; and a land prepit signal of each of the first and second land prepit groups in the radial push-pull signal. Based on the land prepit signal detection circuit, the wobble clock, and the land prepit signals of the first and second land prepit groups,
An optical disc apparatus comprising: a land prepit data detection circuit that determines the land prepit data value indicated by the first land prepit group and the sector synchronization data value indicated by the second land prepit group. . 4. The optical disk device according to claim 3, wherein the land prepit data detection circuit has a land prepit number of (N−1) with respect to the first land prepit group, excluding the sync prepits. / 2 or more and (N-1) or less, the land prepit data value is determined to be "1", while the number of land prepits is (N-1) / excluding the sync prepits. When the number of land prepits is less than 2, it is determined that the land prepit data value is "0", and the number of land prepits is (N-
1) / 2 or more and (N-1) or less, the sector synchronization data value is determined to be "1", while the number of land prepits is (N-1) / excluding the head bit position. An optical disk device characterized by determining that the sector synchronization data value is "0" when the number is less than two.