JP3078242B2 - Optical disk drive - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disk apparatus for recording and reproducing data on a recording and reproducing optical disk capable of recording and reproducing data in units of sectors arranged along a spiral track.

[0002]

2. Description of the Related Art A so-called rewritable optical disk capable of recording and reproducing data has already been commercialized.
Magneto-optical disk, 120 mm phase change disk (commonly known as P
D).

A guide groove for guiding laser beam irradiation is formed in these discs, and tracking is performed by utilizing diffraction of the laser beam by the guide groove. The guide groove is formed continuously and spirally from the inner peripheral side to the outer peripheral side of the disk. This guide groove portion is called a groove, and the portion that is not a guide groove is called a land. In a conventional optical disk, information is recorded on only one of the groove and the land.

On the other hand, information on such an optical disk is
For example, reading and writing are performed in units of 512 bytes or 2048 bytes. This one unit of information unit is called a sector.
This sector is assigned a sector address indicating the address of each sector, and is formatted according to a predetermined sector format in order to record information at a target address and to reproduce information with high reliability. At the time of this formatting, the information of the sector address is recorded by forming irregularities called pits at the head of the sector. The part where the sector address information is recorded is called a header. As described above, in the conventional optical disk, information is recorded on only one of the groove and the land. Therefore, the header is formed only on the groove in the case of groove recording, and formed only on the land in the case of land recording. I was

[0005]

As described above, in the conventional optical disk, information is recorded on only one of the groove and the land. However, if information is recorded on both the land and the groove, more information is recorded. It is easily assumed that the recording capacity can be realized.

However, in order to be able to record information on both the land and the groove, it has been a problem how to form sector addresses. The problem will be described below.

In the conventional optical disk on which the spiral groove is formed, the groove and the land are formed in parallel. Here, each of the groove and the land draws a spiral trajectory in parallel with each other, and a spiral trajectory is formed on the disk by each of the groove and the land. I will call it a spiral structure.

In this double spiral structure, since the groove and the land are formed in parallel, movement from the groove to the land necessarily requires a track jump.
Therefore, when switching the recording and reproduction of information from a groove to a land (or from a land to a groove), a track jump or seek is required, and it becomes difficult to continuously record and reproduce information.

Further, when formatting a disk with such a double spiral structure,
There is no other choice but to format the sectors on the groove (hereinafter referred to as groove sector) and the sectors on the land (hereinafter referred to as land sector) separately. This means that information can be recorded and reproduced alternately on adjacent lands and grooves by the zone CAV method, for example.
This causes inconvenience when formatting the disc.

In other words, in order for adjacent lands and grooves to have continuous sector addresses, it is necessary to format only the grooves and only the lands while intermittently addressing each round. in this case,
Difficulty arises in performing formatting so that the position is aligned at a connection portion where addresses are continuous from land to groove or from groove to land. Further, when the information is recorded and reproduced, if the transition from the land to the groove or from the groove to the land is not performed smoothly, a rotation wait of the disk occurs, which hinders the realization of continuous information recording and reproduction. .

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and has as its object to have a large recording capacity and a high access speed, and at the same time, to continuously record and reproduce information. It is an object of the present invention to provide an optical disk device for accurately and quickly recording and reproducing information on a recording / reproducing optical disk which can be reliably performed.

[0012]

In order to achieve the above-mentioned object, an optical disk device according to the present invention has the following configuration. An optical disk device according to the present invention includes a light irradiating unit that irradiates a light beam to an optical disk, and a light that detects a change in an optical characteristic of reflected light reflected from the optical disk by irradiation of the light beam by the light irradiating unit. Detecting means, and position control means for controlling an irradiation position of the light beam so as to irradiate a predetermined position on the optical disk with the light beam based on a change in the optical characteristic of the reflected light detected by the light detecting means. An optical disc device, comprising: a first recording unit that is a land-shaped area where data is recorded and reproduced; and a data recording and reproduction unit that is formed adjacent to the first recording unit. A second recording section which is a groove-shaped area where recording is performed, and address information corresponding to the first recording section are recorded. An optical disc in which a half header portion and address information corresponding to the second recording portion are recorded, and a second half header portion arranged in a staggered manner in pairs with the first half header portion is arranged along a spiral track. And when the light beam follows the spiral track on which the first recording section and the second recording section of the optical disc are arranged, a position of the spiral track deviated from the track center. The position is controlled by the position control means so as to irradiate the light beam.

Here, in other words, the optical disk is
The optical disk is a land-shaped area in which data is recorded and reproduced, and a first recording unit disposed on a spiral track and data recorded and reproduced in the first recording unit. And a predetermined number of land sectors including a first half header portion arranged prior to the first recording portion are arranged along one circumference of the spiral track to record and reproduce data. A second recording section arranged on the spiral track, and address information of data recorded and reproduced on the second recording section. A second half header portion arranged in a staggered manner prior to the recording portion and in pairs with the first half header portion. But in succession after the land sectors are arranged a predetermined number along one round the spiral track,
A predetermined number of the spiral tracks are arranged along one circumference of the spiral track, and the land sectors are continuously arranged after a predetermined number of the groove sectors are arranged along the circumference of the spiral track. A predetermined number is arranged along
This is an optical disc having a configuration in which the land sector and the groove sector are alternately and continuously switched for each rotation of the spiral track.

[0014] More specifically, the position control means is described in more detail. The spiral track on which the first recording section and the second recording section (or land sector and groove sector) of the optical disk are arranged. When the light beam is made to follow from the first radial side (for example, the inner peripheral side) of the optical disc to the second radial side (for example, the outer peripheral side) of the optical disk, By controlling the position control means to irradiate a light beam to a position shifted toward the first radial direction (for example, the inner circumferential side) of the optical disk, a light beam is applied to a track at a predetermined radial position. , The so-called track hold is automatically performed.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 schematically shows a configuration of a header section in a sector of a recording / reproducing optical disk according to an embodiment of the present invention. In the optical disk having the header portion formed in the configuration shown in FIG. 1, when the track is spirally traced, the tracking polarity is changed to land, groove, land, and groove for each round of the track without going through a track jump. It is configured to be alternately switched. Hereinafter, this configuration will be described.

FIG. 1A shows a configuration of a header section in a sector at the switching of the tracking polarity. Here, the sector at which the tracking polarity is switched will be referred to as a first sector. FIG. 1B shows the configuration of a header section in a sector other than the first sector. In the method in which the groove and the land are alternately switched every track, as described above, it is necessary to switch the polarity of the groove or the land at the time of tracking, and the sector at the switching of the tracking polarity has a different header arrangement from other sectors. Becomes

Header1, Header2, Header3, Header4
Is a region formed by an uneven shape called a pit, and the address information on a predetermined sector is recorded by the uneven shape. The information recording areas indicated by RF1 to RF9 and R1 to R8 are, for example, areas formed of a phase-change recording film, and are hereinafter referred to as a recording unit. In the case of a phase-change recording film, a user records and reproduces information using a difference in reflectance due to a change in optical characteristics between the crystalline state and the amorphous state of the recording film. Of this recording part, RF6 to RF9 and R5
R8 to R8 represent recording portions of the sector in which the guide groove is formed, and are hereinafter referred to as recording portions of the groove sector. On the other hand, RF1 to RF4, R1 and R2 represent recording units of sectors provided in portions other than the guide grooves adjacent to the groove sectors, and are hereinafter referred to as recording units of land sectors.

In FIG. 1, the upper part is shown as a direction corresponding to the outer peripheral side on the disk, and the lower part is shown as a direction corresponding to the inner peripheral side on the disk. Therefore, the vertical direction corresponds to the radial direction on the disk. Further, # (m + N), #
(N + N) and the like represent sector numbers indicating sector addresses. Here, m and n represent certain integers. N represents the number of sectors per track round,
For example, it is a predetermined integer from 17 to 40.

Hereinafter, FIG. 1A will be described in more detail. In FIG. 1A, sector numbers #m and #
(M + N), # (m + 2N), # (m + 3N)
The first sector for the track is shown. The header section in the first sector is formed in a quadruple writing structure by cutting described later. Each part of the header part written in quadruple is Header1, Header2, He, respectively.
ader3 and Header4. In addition, Header1 and Header2 constitute the first half header part, and Header3 and Header4 constitute the second half header part. Of these, the first half header is used as a land sector header, and the second half header is used as a groove sector header.

More specifically, regarding the recording section RF6 of the groove sector # (m) whose address is indicated by the sector number # (m), a Mirrorfield (hereinafter referred to as a mirror section) The second half header section HF2 provided through the above section is used as the header section of the sector. The latter half header part HF at this time
Reference numeral 2 denotes a second-half header portion composed of Header3 and Header4 in which address information of sector number # (m) is recorded. Further, the latter half header portion HF2 is shifted toward the inner periphery by a half track pitch with respect to the position where the recording portion RF6 of the groove sector # (m) is formed.
That is, it is formed at a position displaced by the parallel movement. Note that the track pitch is a distance from the center of the land to the center of the groove in the adjacent land and groove, and is a distance indicated by a symbol P in FIG.

The recording section RF2 of the land sector # (m + N) whose address is indicated by the sector number # (m + N) is provided with a mirror section at the beginning and an area occupied by the latter half header section HF2. Header part HF1 provided through the space of
Are used as a sector header. The first half header section HF1 at this time is a first half header section composed of Header1 and Header2 in which address information of the sector number # (m + N) is recorded. That is, the first half header section HF1 shows the address information indicated by the above-mentioned second half header section HF2 and the address information which is different by one track from the track.
Numeral 1 indicates address information on the outer circumference side of the latter half header portion HF2, which is different by one round of the track. Furthermore, this first half header part HF1
Is the recording part RF2 of the land sector # (m + N)
Is formed at a position shifted to the inner peripheral side by a half track pitch with respect to the position where is formed.

Here, the recording section RF2 of the land sector # (m + N) is formed adjacent to the recording section RF6 of the groove sector # (m). That is, the recording portion RF2 of the land sector # (m + N) is formed on the outer peripheral side by one track pitch with respect to the recording portion RF6 of the groove sector # (m). Therefore, the first half header portion HF1 is formed on the outer peripheral side by one track pitch with respect to the second half header portion HF2. The first half header section HF1 and the second half header section HF2 are continuously formed by cutting, which will be described later.
Header2 and Header3 in the latter half header section HF2 are arranged close to each other. With such an arrangement, the first half header portion HF1 and the second half header portion HF2 are paired with each other to form a staggered header structure.

A land sector # whose address is indicated by the sector number immediately before the sector number # (m) in the recording section RF6 of the groove sector # (m).
The (m-1) recording unit RF1 allocates a space corresponding to an area occupied by the first half header part HF1 between the head part of the latter half header part HF2 which is the header part of the groove sector # (m), that is, the Header3 part. The recording section RF6 of the groove sector # (m) is formed on the same track. Similarly, land sector # (m +
N) sector number # (m) in the recording unit RF2.
The recording unit RF7 of the groove sector # (m + N-1) whose address is indicated by the sector number immediately before (+ N) is the head portion of the first half header portion HF1, which is the header portion of the land sector # (m + N), ie, the Header1 portion. , Recording section RF of land sector # (m + N)
2 are formed on the same track position.

Next, FIG. 1B will be described below. In FIG. 1B, sector numbers #n and # (n +
N) and # (n + 2N) for three tracks. The header portion in this sector is also formed in a quadruple writing structure by cutting described later, as in the case of the first sector described above. Each part of the quadruple-written header is also called Header1, Header2, Header3, and Header4, respectively, similarly to the case of the first sector, and Header1 and Header2 constitute the first half header part used as the header part of the land sector. Header3 and He
ader4 shall constitute the latter half header part used as the header part of the groove sector.

More specifically, as for the recording section R6 of the groove sector # (n) whose address is indicated by the sector number # (n), the second half header provided via the mirror section at the head of the recording section R6. Part H2
Are used as a sector header. The latter half header portion H2 at this time is a latter half header portion composed of Header3 and Header4 in which the address information of the sector number # (n) is recorded. Further, the latter half header portion H2 is formed at a position shifted inward by a half track pitch from the position where the recording portion R6 of the groove sector # (n) is formed, that is, displaced by parallel movement. Have been.

The recording section R2 of the land sector # (n + N) whose address is indicated by the sector number # (n + N) has a mirror section at the beginning and an area occupied by the latter half header section H2. Header part H1 provided through the space of
Are used as a sector header. At this time, the first half header H1 is a first half header composed of Header1 and Header2 in which address information of the sector number # (n + N) is recorded. Further, the first half header portion H1
It is formed at a position shifted from the position where the recording section R2 of the land sector # (n + N) is formed by the half track pitch toward the inner circumference side.

Here, the recording section R2 of the land sector # (n + N) is formed adjacent to the recording section R6 of the groove sector # (n). That is, the recording portion R2 of the land sector # (n + N) is formed on the outer peripheral side by one track pitch with respect to the recording portion R6 of the groove sector # (n). Therefore, the first half header portion H1 is formed on the outer peripheral side by one track pitch with respect to the second half header portion H2. Further, the first half header portion H1 and the second half header portion H2 are continuously formed by cutting, which will be described later, and are formed in the first half header portion H1.
Header2 and Header3 in the latter half header portion H2 are arranged close to each other. With such an arrangement, the first half header portion H1 and the second half header portion H2 are formed as a staggered header structure.

The sector whose address is indicated by the sector number immediately before the sector number # (n) in the recording section R6 of the groove sector # (n) is different from the above-described first sector in the groove sector # (n). n-1). This groove sector # (n-1)
The recording unit R5 has a header portion between the second half header portion H2 and the header portion of the groove sector # (n).
Through the space corresponding to the area occupied by the first half header section H1, the recording section R6 of the groove sector # (n)
Are formed on the same track position. Similarly, the sector indicated by the sector number immediately before the sector number # (n + N) in the recording unit R2 of the land sector # (n + N) is the land sector # (n + N).
N-1). The recording section R1 of the land sector # (n + N-1) is adjacent to the head of the first half header section H1, which is the header section of the land sector # (n + N), and the recording section R2 of the land sector # (n + N).
Are formed on the same track position.

Next, a description will be given of a case where a recording / reproducing optical disk having the above-described configuration is manufactured. When manufacturing an optical disk, first, a master having an uneven shape corresponding to a groove or a pit is manufactured using a method called cutting. The concavo-convex shape formed on the master is transferred to a stamper, and the stamper is used as a mold to mold a resin in which the concavo-convex shape is transferred. This resin is used as a substrate of an optical disk, and a recording film such as a phase-change film is formed on the surface having the unevenness by a method such as vapor deposition. Further, a protective film for protecting the recording film is formed on the recording film by a method such as coating. In this way, an optical disk having grooves, pits, and the like formed thereon is manufactured. It is also possible to manufacture a bonded optical disk by bonding the above-described optical disk substrates via an intermediate layer made of the same material as the protective film.

FIG. 2 shows a master recording apparatus for recording irregularities corresponding to grooves and pits on a master by cutting. In this master recording apparatus, laser light (for example, an Ar laser or a Kr laser) emitted from a laser light source 41 enters a laser optical axis control system 42 for adjusting an optical axis, and changes in optical axis due to a temperature change of the laser light. Is dealt with. The laser light is reflected by the mirror 43,
EO modulator 44 controlled by format circuit 49
The laser light is modulated into a laser beam having an arbitrary signal by a beam modulation system 44 composed of a and 44b. Here, the laser light can be modulated into a predetermined format signal. In addition,
The format circuit 49 controls the beam modulation system 44 so as to modulate the laser light according to a cutting operation described later. Subsequently, the laser beam passes through a beam shaping system 45 including a pinhole and a slit, and the beam diameter and shape are adjusted. The adjustment of the laser beam is completed up to here, and the beam shape can be confirmed by the beam monitor system 46. The laser light is further guided by the mirror 47 and focused and irradiated on the optical recording master 40 by the objective lens 48. As the optical recording master 40, for example, a glass disk is used. A photosensitive paint (photoresist) is applied on the glass disk, and the surface of the photosensitive paint is irradiated with laser light. The portion exposed by the laser beam becomes concave when etched. The surface shape formed by this laser light irradiation is made into a desired uneven shape, and a groove and a format pattern are recorded. A stamper is manufactured based on the glass disk thus processed.

At the time of cutting, rotating means 3 such as a motor
In step 9, the glass disk 40 is rotated, for example, at a constant speed. Further, an optical pickup having an objective lens 48 for irradiating a predetermined position on the glass disk 40 with laser light moves at a constant speed from the inner peripheral side to the outer peripheral side of the crow disk 40. At the time of cutting, the optical pickup moves at a constant speed from the inner circumference to the outer circumference at a rate corresponding to the track pitch per rotation of the disk, and moves the irradiation position of the laser light with this movement. With the optical pickup that moves in this manner, a portion irradiated with laser light becomes a groove, and a portion not irradiated becomes a land. In the header portion, pits having irregularities are formed by blinking a laser beam.

Next, the cutting operation in the embodiment of the present invention will be described with reference to FIG. In FIG. 1A, it is assumed that the processing of cutting the recording unit RF1 of the land sector # (m-1) whose address is indicated by the sector number # (m-1) ends at a certain time point t0. As described above, in the land area such as the recording section RF1 of the land sector # (m-1), laser light irradiation from the optical pickup is not performed, but only the laser light irradiation position is moved. The movement of the laser beam irradiation position is performed by rotating the optical disk, moving the optical pickup, and driving the objective lens provided in the optical pickup.

At this time t0, land sector # (m
After the processing for the recording unit RF1 of -1) is completed, subsequently, the irradiation position of the laser beam is shifted from the track center of the recording unit RF1 of the land sector # (m-1) to the half track outer periphery side. At the shifted track position, Header1 and Header2 with sector numbers # (m + N), that is, the first half header section HF1 is recorded. At this time, the laser light emitted from the optical pickup is turned on and off so that pits corresponding to the information indicating the sector number are formed. Note that Header1 in the first half header section HF1
Is the recording unit RF1 of the land sector # (m-1)
Is recorded in close proximity. After the recording of the Header1, the Header2 in the first half header section HF1 is recorded continuously to the Header1.

When the cutting recording of Header1 and Header2 with the sector number # (m + N), that is, the first half header section HF1, is completed, the laser beam is then moved inward by one track pitch from the track center of Header1 and Header2. Move the irradiation position. That is, land sector # (m-
The laser beam irradiation position is shifted to the inner peripheral side by a half track pitch from the track center in the recording unit RF1 of 1). At the position of the shifted track, Header3 and Header4 having sector numbers # (m), that is, the latter half header portion HF2 is recorded. At this time, the laser light emitted from the optical pickup is turned on and off so that pits corresponding to the information indicating the sector number are formed. Note that Header3 in the second half header section HF2 is recorded close to Header2 in the first half header section HF1. And this Header3
After the recording of Header4, Header4 in the latter half header section HF2 is recorded continuously to Header3.

Header3 and He with sector number # (m)
ader4, that is, when the cutting recording of the latter half header part HF2 is completed, subsequently, the recording recording of the recording part RF6 of the groove sector # (m) is performed after passing through the mirror part. At this time, the mirror section does not emit laser light. Also, the laser beam irradiation position is moved to the outer peripheral side by a half track pitch from the track center of Header3 and Header4 of sector number # (m). That is, land sector # (m
-1) is the same track position as the track center in the recording section RF1, and has the sector number # (m +
N) The laser beam irradiation position is shifted to the track position on the inner circumference side by a half track pitch from the track center in Header1 and Header2.

At the position of the shifted track, the cutting recording of the recording section RF6 of the groove sector # (m) is performed. The recording section RF6 of the groove sector # (m) irradiates a laser beam and forms a groove shape, that is, a groove by etching the photosensitive paint. At this time, the spot of the laser beam is shifted from the inner peripheral side to the outer peripheral side,
That is, the groove is formed in a wave shape by sine wave vibration in the radial direction of the disk, for example, at a period of 186 channel bits. The signal component obtained from the wavy groove can be used as a reference signal for clock generation at the time of data writing (that is, at the time of recording information on the recording / reproducing optical disk).

From sector number # (m) to sector number # (m
In one round up to + N-1), all sectors are groove sectors. In these groove sectors, cutting recording is performed according to a predetermined procedure described below.
Here, cutting for sectors other than the first sector will be described with reference to FIG.

In FIG. 1B, a sector number # (n-
1) Groove sector # (n) indicated by the address
It is assumed that the cutting process for the recording unit R5 of -1) ends at a certain time point t1. After finishing the processing for the recording section R5 of the groove sector # (n-1), the irradiation position of the laser beam is shifted from the track center of the recording section R5 of the groove sector # (n-1) to the half track outer circumference side. Shift. At the shifted track position, Header1 and Header2 with sector numbers # (n + N), that is, the first half header portion H1 is recorded. At this time, the laser light emitted from the optical pickup is turned on and off so that pits corresponding to the information indicating the sector number are formed. He in the first half header H1
ader1 is recorded close to the recording section R5 of the land sector # (n-1). After the recording of the Header1, the Header2 in the first half header portion H1 is recorded successively to the Header1.

When the cutting recording of the headers H1 and H2 with the sector number # (n + N), that is, the first half header H1, is completed, the laser beam is then radiated to the inner circumference by one track pitch from the track center of the H1 and H2. Move position. That is, groove sector # (n-
The laser beam irradiation position is shifted to the inner peripheral side by a half track pitch from the track center in the recording section R5 of 1). At the shifted track position, Header3 and Header4 with the sector number # (n), that is, the latter half header portion H2 is recorded. At this time, the laser light emitted from the optical pickup is turned on and off so that a pit corresponding to the information indicating the sector number is formed. Header3 in the second half header section H2 is the same as that in the first half header section H1.
Recorded close to Header2. Then, after recording of this Header3, the second half header portion H2 is continued to this Header3.
Header4 at is recorded. After the cutting recording of Header3 and Header4, which are sector numbers # (n), that is, the second half header section H2, the recording section R of the groove sector # (n) is passed through the mirror section.
6. Make a cutting record. At this time, the mirror section does not emit laser light. The head of sector number # (n)
The laser beam irradiation position is moved from the track center of er3 and Header4 toward the outer periphery by a half track pitch. That is,
The laser is located at the same track position as the track center in the recording section R5 of the groove sector # (n-1), and at a track position on the inner peripheral side by a half track pitch from the track center in Header1 and Header2 of the sector number # (n + N). The light irradiation position is shifted.

At the shifted track position, the cutting recording of the recording section R6 of the groove sector # (n) is performed. In the recording section R6 of the groove sector # (n), a laser beam is irradiated and a groove shape, that is, a groove is formed by etching the photosensitive paint. At this time, the spot of the laser beam is shifted from the inner peripheral side to the outer peripheral side,
That is, the groove is formed in a wave shape by sine wave vibration in the radial direction of the disk, for example, at a period of 186 channel bits. The signal component obtained from the wavy groove can be used as a reference signal for clock generation at the time of data writing.

By repeating the same operation as the cutting operation for the groove sectors # (n-1) to # (n), the groove of the sector number # (m) shown in FIG. Cutting recording is performed from the recording unit RF6 of the sector to the recording unit RF7 of the groove sector with the sector number # (m + N-1).

After the cutting recording from the recording section RF6 of the groove sector # (m) to the recording section RF7 of the groove sector # (m + N-1) is performed,
Again, the cutting process for the first sector shown in FIG. 1A is performed. The first sector at this time is a land sector # (m + N) following the groove sector # (m + N-1). This land sector # (m +
N) from sector number # (m + N) to sector number # (m + N).
In one round up to 2N-1), all sectors are land sectors. Therefore, these land sectors #
In one round from (m + N) to land sector # (m + 2N-1), no laser light is emitted during cutting. At this time, the header portion of each land sector is already formed at the same time when the groove sector on the inner circumference side of one track is cut.

After the cutting process from the land sector with the sector number # (m + N) to the land sector with the sector number # (m + 2N-1) is performed, the cutting process on the first sector is performed again. At this time, the first sector is a land sector # (m + 2N-
Groove sector # (m + 2N) following 1). The cutting of the sector ahead of the groove sector # (m + 2N) is performed by the same operation as the cutting of the sector performed from the groove sector # (m). By repeating this operation, a sector having a header portion having the configuration shown in FIG. 1 is formed.

Here, when the above-described cutting recording is performed, the header portion in the groove sector, that is, He
The latter half header portion consisting of ader3 and Header4 and the recording portion of the groove sector having the same sector number as the sector number in this header portion are continuously recorded by cutting. For example, Header3 and He of sector number # (m)
The second half header section HF2 consisting of ader4 and groove sector #
Cutting is continuously performed with the recording unit RF6 of (m).

However, the header portion in the land sector, that is, the first half header portion composed of Header1 and Header2, and the recording portion of the land sector having the same sector number as the sector number in this header portion are not continuously cut and recorded, and the track 1 is not recorded. It will be recorded on the wrong track. For example, Header1 of sector number # (m + N) and
First half header section HF1 consisting of Header2 and land sector #
The recording is recorded in one cycle different from the recording section RF2 of (m + N). Therefore, if there is a difference between one cycle of the disk rotation and the recording signal cycle of N sectors, the header section in the land sector is shifted from the recording section of the land sector indicated by the sector number by the header section. The cutting is recorded in a state where the error occurs.

Next, in the case where information is recorded / reproduced on an optical disk manufactured by cutting and recording with such a deviation of the header portion, the header portion can be detected with high reliability. The sector format according to the embodiment of the present invention will be described.

FIG. 3A shows an entire structure of a sector according to the embodiment of the present invention. FIG.
(B) shows the header portion of this sector in more detail.

In FIG. 3A, a sector has a total number of bytes of 2697 bytes, a 128-byte header field (hereinafter referred to as a header portion), and a 2-byte Mirrorfiel.
d (hereinafter, referred to as a mirror unit) and a 2567-byte Recording field (hereinafter, referred to as a recording unit). Note that these header section, mirror section, and recording section indicate the same sections as the header section, mirror section, and recording section described when referring to FIG.

The header portion and the mirror portion are portions that have been recorded as uneven shapes before the shipment of the optical disk. The operation of recording in advance an uneven shape according to a predetermined format on an optical disk before shipment is called preformatting.

On the other hand, the recording section is a section in which information identified by the address information indicated by the corresponding header section is recorded according to a predetermined format by a user of the optical disk after shipping the optical disk. In this recording unit, when only the above preformat is performed, only the shape of a groove or a land is formed as an area where information is recorded.

For example, when the optical disk is a phase-change type optical disk, such information recording on the recording unit corresponds to information to be recorded on a phase-change type recording film provided in the recording unit. This is performed by irradiating the laser light modulated by the laser beam, and forming a crystalline region and an amorphous region on the recording film by the modulation of the laser light. Then, the user reproduces information by utilizing a difference in reflectance due to a change in optical characteristics between the crystalline state and the amorphous state of the recording film in the recording unit.

This recording unit is, for example,
(10 + J / 16) byte gap (Gap field)
), Guard1 fiel of (20 + K) bytes
d), 35-byte VFO 3 part (VFO3 field), 3-byte pre-sync part (PS field), 2418-byte data part (Data field), 1-byte PA3 part (PA3 field),
(55-K) byte guard 2 field (Guard2 field),
(25-J / 16) byte buffer section (Bufferfield
The information is recorded in a format composed of (1) and (2). Here, J is an integer of 0 to 15 and K is an integer of 0 to 7, both of which take random values.

FIG. 3B shows the contents of the header in the sector format of the optical disk according to the embodiment of the present invention. This header part is Header1fie
ld, Header2 field, Header3 field, Header4 field
Consists of These are the H described with reference to FIG.
Refers to the same as eader1, Header2, Header3, and Header4. In the following, these are referred to as Header
1, Header2, Header3, and Header4. Note that Header1 has a length of 46 bytes, Header2 has a length of 18 bytes, Header3 has a length of 46 bytes, and Header4 has a length of 18 bytes. The entire header portion has a length of 128 bytes.

These Header1, Header2, Header3, He
Each part in ader4 is VFO part, AM part, PID part, IED
Section and PA section. This configuration will be described below.

The VFO section is an abbreviation for Voltage Frequency Oscillator, and is a pull-in area for a PLL (Phase Locked Loop). That is, the VFO section is read by an optical disk device (described later) that records and reproduces information on and from the optical disk, and synchronizes with the information reproduced from the optical disk to read data and control the rotation speed of the optical disk. The synchronization signal (clock signal) used for
It consists of a continuous repetitive data pattern to be extracted by the PLL circuit in this optical disk device. This data pattern is repeated continuously to lock the PLL and fully synchronize. When the PLL is locked to this data pattern and the clock signal is generated by completely synchronizing, the VFO code pattern fluctuates with the fluctuation of the rotation of the optical disk, so reliable data reading and disk rotation control are realized. can do.

This VFO section has a length of 36 bytes as VFO1 in Header1 and Header3, while
In ader2 and Header4, VFO2 has a length of 8 bytes. That is, as described above, Header1 and Head1
The first half header section is formed from er2, and is used as the header section of the land sector.In this first half header section, the VFO section of Header1, which is the first section, is made higher than the VFO section of Header2 irradiated with laser light following this Header1. It is long. Similarly, the latter half header section is composed of Header3 and Header4, which is used as the header section of the groove sector.In this latter half header section, the VFO section of Header3, which is the first section, is followed by a laser beam following this Header3. It is longer than the VFO section of Header4 to be irradiated.
By setting the VFO section in each sector to be at least 8 bytes long, it is possible to normally pull in the PLL.

As described above, He at the beginning of each sector
If the VFO section of ader1 and the VFO section of Header3 are longer than the VFO section of Header2 and the VFO section of Header4, which are not the leading sections, the PLL can be more reliably pulled in by the VFO section. Therefore, the header of each sector can be detected with high reliability, and information can be recorded / reproduced more accurately.

Of these, increasing the length of the VFO section of Header 1, which is the head of the land sector, requires information on an optical disc manufactured by cutting and recording by producing a shift in the header section of the land sector as described above. This is particularly effective when recording / reproducing is performed.

That is, in the case of a land sector, there is a time difference of one turn between the cutting of the header section and the cutting of the recording section of the land sector indicated by the header section by the sector number. Here, if there is a difference between one cycle of the disk rotation and the recording signal cycle of N sectors, the header part in the land sector is shifted from the recording part of the land sector indicated by the sector number by the header part. The cutting is recorded in the state where the error occurs. If such a shift occurs between the header section and the recording section, detection of the header section becomes more difficult than usual. If there is an offset or the like during tracking in addition to the deviation of the header part, the quality of the reproduced signal differs between the header part in the land sector and the recording part of the land sector whose sector number is indicated by the header part. This also makes the detection of the header part more difficult than usual.

However, even in these cases, the VFO of Header 1, which is the head of the land sector,
Since the length of the header is increased, the PLL is pulled in with high reliability, the header detection accuracy is increased, and the header can be detected accurately and reliably.

AM is an abbreviation of Address Mark and is a synchronization code having a length of 3 bytes, and is used for judging a word boundary at the time of demodulation. The PID is an abbreviation of Physical ID and is composed of sector information having a length of 1 byte and a sector number having a length of 3 bytes. IED is an abbreviation of ID Error Detection code, which is a code to detect errors of 4 bytes of PID.
It has a length of 2 bytes. PA is an abbreviation of Post amble, and is a code necessary to determine the state of the previous byte at the time of demodulation and has a length of 1 byte.

Next, a description will be given of a case where the embossed portion of the recording / reproducing optical disk having the above-mentioned header configuration, that is, the header portion formed of pits having irregular shapes is read at the time of recording / reproducing information.

FIG. 4 is a block diagram showing an overall configuration of an optical disk apparatus for recording and reproducing information on and from an optical disk for recording and reproduction. In FIG. 4, a recording / reproducing optical disc 1 which is a disc-shaped information storage medium is rotated by a spindle motor 3 at a constant linear velocity, for example. The spindle motor 3 is controlled by a motor control circuit 4. Recording and reproduction of information on the optical disk 1 are performed by the optical pickup 5. The optical pickup 5 is fixed to a drive coil 7 constituting a movable portion of a linear motor 6, and the drive coil 7 is connected to a linear motor control circuit 8.

[0064] speed detector 9 to the linear motor control circuit 8 is connected, the speed signal of the optical pickup 5 detected by the speed detector 9 is sent to the linear motor control circuit 8.
A permanent magnet (not shown) is provided at a fixed portion of the linear motor 6. When the drive coil 7 is excited by the linear motor control circuit 8, the optical pickup 5 is moved in the radial direction of the optical disc 1.

The optical pickup 5 is provided with an objective lens 10 supported by a wire or a leaf spring (not shown). The objective lens 10 can be moved in the focusing direction (the direction of the optical axis of the lens) by driving the drive coil 11, and can be moved in the tracking direction (the direction orthogonal to the optical axis of the lens) by driving the drive coil 12. Is possible.

By the drive control of the laser control circuit section 13,
A laser light beam is emitted from the semiconductor laser oscillator 19 . The laser control circuit 13, modulation circuit 14 and laser system
The control circuit 15 operates in synchronization with a recording clock signal supplied from the PLL circuit 16. The modulation circuit 14
The recording data supplied from the error correction circuit 32 is modulated into a signal suitable for recording, for example, 8-16 modulation data. The laser control circuit 15 drives the semiconductor laser oscillator (or argon neon laser oscillator) 19 according to the 8-16 modulation data from the modulation circuit 14.

The PLL circuit 16 divides the basic clock signal generated from the crystal oscillator at the time of recording into a frequency corresponding to the recording position on the optical disk 1, thereby generating a clock signal for recording. A reproduction clock signal corresponding to the reproduced synchronization code is generated, and a frequency abnormality of the reproduction clock signal is detected. The detection of the frequency abnormality is performed based on whether or not the frequency of the reproduction clock signal is within a predetermined frequency range corresponding to the recording position of the data to be reproduced on the optical disk 1. Further, the PLL circuit 16 controls the control signal from the CPU 30 and the data reproduction circuit 1.
And a clock signal for recording or reproduction is selectively output in accordance with the signal from .

The laser light beam emitted from the semiconductor laser oscillator 19 is irradiated on the optical disk 1 via the collimator lens 20, the half prism 21, and the objective lens 10. The reflected light from the optical disc 1
0, a half prism 21, a condenser lens 22, and a cylindrical lens 23, and are guided to a photodetector 24.

The photodetector 24 is a four-divided photodetection cell 24
a, 24b, 24c and 24d. The output signal of the light detection cell 24a is connected to one end of an adder 26a via an amplifier 25a, and the output signal of the light detection cell 24b is connected to one end of the adder 26b via an amplifier 25b.
The output signal of c is supplied to the other end of the adder 26a via the amplifier 25c, and the output signal of the photodetector cell 24d is supplied to the other end of the adder 26b via the amplifier 25d.

The output signal of the photodetection cell 24a is supplied to one end of an adder 26c via an amplifier 25a, and the output signal of the photodetection cell 24b is supplied to an adder 26d via an amplifier 25b.
At one end, the output signal of the photodetector cell 24c is
And the output signal of the photodetector cell 24d is supplied to the other end of the adder 26c via the amplifier 25d.

The output signal of the adder 26a is a differential amplifier OP
2, and the output signal of the adder 26b is supplied to the non-inverting input terminal of the differential amplifier OP2. The differential amplifier OP2 outputs a signal related to the focus point according to the difference between the two output signals of the adders 26a and 26b.
This output is supplied to the focusing control circuit 27.
The output signal of the focusing control circuit 27 is supplied to the focusing drive coil 12. As a result, control is performed such that the laser beam is always just focused on the optical disc 1.

The output signal of the adder 26c is the differential amplifier OP
1, and the output signal of the adder 26d is supplied to the non-inverting input terminal of the differential amplifier OP1. The differential amplifier OP1 outputs a track difference signal according to the difference between the two output signals of the adders 26c and 26d. This output is supplied to the tracking control circuit 28. The tracking control circuit 28 creates a track drive signal according to the track difference signal from the differential amplifier OP1.

The track drive signal output from the tracking control circuit 28 is the drive coil 1 in the tracking direction.
1 is supplied. Further, a track difference signal used in the tracking control circuit 28 is supplied to the linear motor control circuit 8.

By performing the focusing control and the tracking control, the sum signal of the output signals of the photodetector cells 24a,... 24d of the photodetector 24, that is, the sum of the output signals of the adders 26c and 26d is added. Some adder 26
The change in the reflectance from the pits formed on the tracks of the optical disk 1 corresponding to the recording information is reflected in the output signal e. This signal is supplied to the data reproducing circuit 18. The data reproduction circuit 18 reproduces the recorded data based on the reproduction clock signal from the PLL circuit 16.

The data reproducing circuit 18 has an adder 26
In addition to detecting the sector mark in the preformat data based on the output signal of e and the reproduction clock signal from the PLL circuit 16, based on the binarized signal and the reproduction clock signal supplied from the PLL circuit 16, A track number and a sector number as address information are reproduced from the binary signal.

The reproduced data of the data reproducing circuit 18 is
9 is supplied to the error correction circuit 32. The error correction circuit 32 outputs an error correction code (ECC) in the reproduced data.
) To correct the error, or add an error correction code (ECC) to the recording data supplied from the interface circuit 35 and output it to the memory 2.

The reproduced data whose error is corrected by the error correction circuit 32 is transmitted to the bus 29 and the interface circuit 3.
5, and is supplied to a recording medium control device 36 as an external device. The recording data emitted from the recording medium control device 36 is supplied to the error correction circuit 32 via the interface circuit 35 and the bus 29.

When the objective lens 10 is moved by the tracking control circuit 28, the linear motor 6, that is, the optical pickup 5 is moved by the linear motor control circuit 8 so that the objective lens 10 is located near the center position in the optical pickup 5. Be moved.

The D / A converter 31 is used for exchanging information between the focusing control circuit 27, the tracking control circuit 28, the linear motor control circuit 8, and the CPU 30 for controlling the entire optical disk apparatus.

The motor control circuit 4, the linear motor control circuit 8, the laser control circuit 15, the PLL circuit 16, the data reproduction circuit 18, the focusing control circuit 27, the tracking control circuit 28, the error correction circuit 32 and the like are connected via a bus 29. It is controlled by the CPU 30. The CPU 30 has the memory 2
A predetermined operation is performed by the program recorded in the.

Here, when information is recorded / reproduced on the recording / reproducing optical disk according to the present invention by the optical disk apparatus having the above-described configuration, a case where a header portion preformatted on the optical disk is read is described. This will be described with reference to FIG.

In FIG. 1A, for example, when the target header section to be read is the header section HF2 of the groove sector indicated by the sector number # (m), the header section HF2 is read prior to reading. , Sector number #
The recording section RF1 of the land sector indicated by (m-1) is irradiated with laser light. The laser beam spot applied to the recording unit RF1 follows the track center of the recording unit RF1. The tracking of the laser beam spot is performed by the tracking control in the optical disk device described with reference to FIG.

The laser beam applied to the recording section RF1 of the land sector indicated by the sector number # (m-1) while following the track center is followed by the header sections HF1 and HF2 recorded on the optical disk. Is irradiated.

As described above, the header sections HF1 and HF
2 is composed of data having a total length of 128 bytes. Here, if one byte has a length of about 3 μm on the disk, the header sections HF1 and HF2 have a length of about 400 μm. Further, assuming that laser light irradiation is performed on the disk at a linear velocity of about 6 m / s, the time is about 67 m / s.
In μs, the light spot of the laser beam is
Pass through.

Even if the header portion changes in a staggered manner as shown in FIG. 1 in such a short time, the band of the tracking control system is sufficiently small and the light spot cannot follow. Therefore, it can be considered that the light spot follows the virtual track center. The center of this virtual track is the header section HF1
And HF2, different from the normal track center, but data such as address information preformatted in the header portions HF1 and HF2 can be sufficiently read. After the header sections HF1 and HF2 are read, the laser beam emitted from the optical pickup passes through the mirror section, and then enters the recording section RF6 of the groove sector indicated by the sector number # (m) to the center of the track. Will be applied.

In this case, the recording unit of the sector irradiated with the laser beam subsequent to the header units HF1 and HF2 is the recording unit RF6 of the groove sector. As described above, the header portion used in the groove sector is
This is the latter half header part composed of Header3 and Header4. In the header parts HF1 and HF2 read earlier, the header part HF2 is the latter half header part. Therefore, the second half header section HF2 is used as the header section of the recording section RF6.
The address information of RF6 will be indicated.

As described above, the optical disk according to the present invention has the header portions arranged in a staggered manner. FIG. 5 is a schematic diagram showing the staggered header portion and the structure around the header portion. In FIG. 5, the upper side is shown as the direction corresponding to the inner peripheral side on the disk, and the lower side is shown as the direction corresponding to the outer peripheral side on the disk. Therefore, the vertical direction corresponds to the radial direction on the disk.

In FIG. 5, the sector address is 3000
The case of sectors from 0h to 30133h is illustrated. Here, the letter h added after the number is hexadecima
l is an abbreviation for hexadecimal. FIG.
In, the portion represented by the hexadecimal number is shown as a recording portion, and the portion shown only by a numeral without the letter h is shown as a header portion.

Further, in the recording section of each sector, the sector address is 30000h, 30001
The sectors indicated by h, 30010h, 30022h, 30023h... indicate that they are grooves. Also, the sector address is 30011h, 30012
h, 30021h, 30033h, 30034h... indicate that the sector is a land.

At this time, the header part indicated by a certain number is replaced with the same number as the number indicating the header part by the letter h.
The same sector is formed by pairing with a recording unit to which is added. In the drawing, the header part indicated by 30000 is replaced with (30000h) header part, 3000
If the recording section of the groove sector indicated by 0h is described as a (30000h) groove sector recording section, for example, the (30000h) header section and the (30000h) groove sector recording section are paired and the same sector is defined. Form. in this case,
(30000h) Sector address 300 in the header
The sector information of 00h is recorded in the preformat, and the user records the information indicated by the sector address 30000h in the (30000h) groove sector recording section.

FIG. 5 schematically shows the same configuration as the configuration of the header section according to the present invention described with reference to FIG. In the optical disk having the header portion formed in the configuration shown in FIG. 5, as described with reference to FIG. 1, when the track is spirally tracked, tracking is performed for each round of the track without a track jump. Are alternately switched between land, groove, land, and groove.

In the case of FIG. 5, the number of sectors per track is indicated as 17 (11h in hexadecimal notation). When the track makes one round, the sector address of the track adjacent to the outer peripheral side is only 17 To increase. For example, a sector adjacent to the outer peripheral side of a sector having a sector address of 30000h is a sector having a sector address of 30011h.

In FIG. 5, the sector address is 3000
The sectors indicated by 0h, 30011h, 30022h, 30033h... Are sectors at which the tracking polarity is switched, and are the above-mentioned first sectors. The sector addresses are 30010h, 30021h, 3
0032h, 30043h... And
30001h, 30012h, 30023h, 3003
4h are sectors other than the first sector.

In the method in which the groove and the land are alternately switched for each round of the track as described above, it is necessary to switch the polarity of the groove or the land during tracking, and the sector at which the tracking polarity is switched is different from the other sector. It has a different header arrangement.

Here, for example, the address number 30011h is preliminarily recorded in the first half header portion and the address number 30000h is preliminarily recorded in the second half header portion with respect to the (30000h) groove sector recording portion. (30000h) Since the groove sector recording section is a groove, the address number 30000h recorded in the second half header section is used as the sector address.

On the other hand, for example, (30011h) the address number 30011h is preliminarily recorded in the first half header portion and the address number 30022h is preliminarily recorded in the second half header portion with respect to the land sector recording portion. (30011h) Land Since the sector recording section is a land, the address number 30011h recorded in the first half header section is used as the sector address.

The positional relationship of such a staggered header will be described in the case of a groove sector. The first half header portion has an outer wobble and the second half header portion has an inner wobble. That is, the first half header portion is provided so as to be shifted from the track position of the groove sector by the half track pitch toward the outer periphery of the disk, and the second half header portion is provided by the half track pitch toward the inner periphery of the disk. It is provided so as to have a positional relationship shifted only by. On the other hand, in the case of the land sector, the relationship is reversed with the case of the groove sector, and the first half header portion has an inner wobble,
The latter half header part has a relationship of the outer wobble.

In the system in which the groove and the land are alternately switched every track, it is necessary to switch the polarity of the groove or the land during tracking. The timing of the polarity switching is performed in accordance with the reading of the header section. That is, according to the information obtained by the reading, before starting the tracking of the recording part following the header part, it is determined whether the recording part is a land or a groove and a predetermined polarity is determined. Switch to

If information obtained from the header part is used,
When the subsequent recording unit is identified as a land, the tracking of the recording unit is performed with the tracking polarity as the land. If the subsequent recording section is identified as a groove based on the information obtained from the header section, the recording section performs tracking with the tracking polarity as the groove.

The switching of the tracking polarity is performed when the position on the disk irradiated with the laser beam is a mirror section (Mirror field), as shown in FIG. When specifying the position of the mirror section, the information obtained from the header section is used as described above. That is, Header1, Header2, Header3, Header
If any one of the information items 4 can be accurately read, the position of the mirror unit can be specified by calculating the position of the mirror unit from the read position.

For example, when the reading of Header1 is performed normally, the counting of the number of bits is started from the end of the reading of Header1. Here, since the sector format of the header portion is predetermined as shown in FIG.
The number of remaining bits from the read end position of ader1 to become a mirror portion is also predetermined. Therefore, when a predetermined number of bits are counted from the end of the reading of Header1, it is recognized that the laser beam has been irradiated to the mirror unit, and the tracking polarity is switched here. After the tracking polarity is switched to a predetermined polarity by the mirror unit, tracking of the land or groove recording unit is performed.

In the land / groove polarity switching performed in this manner, the above-described relationship between the inner wobble and the outer wobble can be used for detecting the switching timing. Hereinafter, a configuration for detecting the land / groove polarity switching timing using the relationship between the inner wobble and the outer wobble will be described.

The photodetector 24 shown in FIG. 4 is used for detecting the land / groove polarity switching timing.
The photodetector 24 includes four divided photodetection cells 24a and 24.
b, 24c and 24d. As described above, the output signal of the light detection cell 24a and the output signal of the light detection cell 24b are added by the adder 26c, and the output signal of the light detection cell 24c and the output signal of the light detection cell 24d are added by the adder 26d. You.

An output signal of the adder 26c is a differential amplifier OP
1, and the output signal of the adder 26d is supplied to the non-inverting input terminal of the differential amplifier OP1. The differential amplifier OP1 outputs a track difference signal corresponding to the difference between the two output signals of the adders 26c and 26d, and this output is supplied to the tracking control circuit 28, so that the tracking control circuit 28 A track drive signal is created according to the track difference signal from the CPU.

By supplying the track drive signal output from the tracking control circuit 28 to the drive coil 11 in the tracking direction, the track difference signal used in the tracking control circuit 28 is supplied to the linear motor control circuit 8. Thus, tracking control is performed.

Here, the photodetector 24 is connected to the photodetector cell 24.
a and a first photodetection cell pair consisting of photodetection cells 24b;
Considering that the second light detection cell pair including the light detection cell 24c and the light detection cell 24d is divided into two pairs,
The pair of pairs is divided corresponding to the direction along the recording track of the optical disk.

For the sake of explanation, of the two divided photodetection cells, a first photodetection cell pair is provided corresponding to the outer peripheral side of the recording track, and an output signal from this first photodetection cell pair is provided. Is A. Further, of the two divided photodetection cells, a second photodetection cell pair is provided corresponding to the inner peripheral side of the recording track, and the output signal from this second photodetection cell pair is B. .

Thus, when the light beam is irradiated following the track, the output of the signal A increases and the output of the signal B decreases when the light beam passes through the header portion wobbled to the outer peripheral side. . On the other hand, when the light beam passes through the header portion wobbled inward, the output of signal B increases and the output of signal A decreases.

Therefore, when the (AB) signal which is the difference between the two signals is generated, (AB)> 0 in the header portion wobbled on the outer peripheral side, and (AB) in the header portion wobbled on the inner peripheral side. ) <0, otherwise (AB) = 0.
For the sake of simplicity, the state of (AB)> 0 is represented by “+”,
B) The state of <0 is represented by “−”, and the state of (AB) = 0 is represented by “0”.

When the (AB) signal output from the photodetector 24 is used, when the light beam passes through the groove sector, the light beam is irradiated to the recording section of the groove sector. First, (A-
B) The signal output shows a change from "+" to "-". On the other hand, when the light beam passes through the land sector, the (AB) signal output shows a change from "-" to "+" prior to the irradiation of the recording section of the land sector with the light beam. Therefore, the polarity change of the (A-B) signal output is monitored by the tracking control circuit via the differential amplifier OP1 and processed by the CPU 30 to detect land / groove. It is possible to perform detection.

That is, the above (AB) signal output is "+"
When the change from “−” to “−” is indicated, it is detected that the recording unit to which the light beam is subsequently irradiated is the recording unit of the groove sector. If the groove sector at this time is a groove sector in the first sector, control is performed so that the tracking polarity is switched from land to groove in order to perform tracking control normally.

Similarly, when the (AB) signal output shows a change from "-" to "+", the recording unit to which the light beam is subsequently irradiated is the recording unit of the land sector. It is detected that there is. If the land sector at this time is a land sector in the first sector, control is performed so that the tracking polarity is switched from groove to land in order to perform tracking control normally.

As described above, it is possible to detect the timing of switching the land / groove polarity by utilizing the polarity change of the (AB) signal output. Next, this land / groove polarity switching timing detection
A description will be given of a method of using recording information inside the header recorded on the optical disc by preformat, that is, using the sector type bit inside the header.

Prior to the description, the header structure shown in FIG. 5 will be described. In the optical disk having the staggered header portion as shown in FIG. 5, the cutting of the disk having the single spiral structure is moved from the inner circumference to the outer circumference by adopting the sector address numbering method described above with reference to FIG. Has already been described that can be performed by continuous recording which only needs to be performed once. The recording signal at the time of this cutting is transmitted from the format circuit 49 in the master recording apparatus shown in FIG. 2 in the following order, and the beam modulation system 44 including the E / O modulators 44a and 44b is controlled. Thus, cutting is performed in accordance with the above-described sector address numbering system.

The transmission order of the recording signals is "(3001
1h) Header section → (30000h) Header section → (300
00h) Groove sector recording section →… → (3
0021h) Header → (30010h) Header →
(30010h) Groove sector recording section →
Blank for one round → (30033h) Header section → (30022)
h) header section → (30022h) groove sector recording section →... omitted here.

Here, the specific contents of the (30011h) header portion will be described with reference to FIG.
03001 in lower 3 bytes of PID part 1 (4 bytes)
This is an emboss header in which 1h is recorded and 030011h is recorded in the lower 3 bytes of the PID 2 part (4 bytes) of Header2. Also, the specific contents of the (30000h) header portion are that 030000h is recorded in the lower 3 bytes of the PID 3 portion (4 bytes) of Header3,
030000 in lower 3 bytes of 4 parts (4 bytes) of PID
This is an emboss header recording h.

According to the sector address numbering system as described above, a land-groove recording disk of a single spiral system can be manufactured. In this disk, sector addresses are continuous, and the entire surface can be processed without intervening track jumps or seeks during continuous recording and reproduction.

However, as described above, in a single spiral type land-groove recording disk, it is necessary to switch the tracking polarity every other turn in order to perform the tracking control operation correctly. That is, in FIG. 5, in the (30010h) groove sector recording section, the tracking polarity is set to groove, but the portion irradiated by the light beam is (30011h).
h) Grooves must be performed in the header section, and (30011h) tracking must be performed in the land sector recording section in the land polarity.

The switching of the tracking polarity may be performed by using the polarity of the (AB) signal, or by using a sector type bit in the header described below.

FIG. 3B shows the contents of the PID part in the header. One part of PID and Header2 are included in Header1.
The PID has two PIDs, the Header3 has three PIDs, and the Header4 has four PIDs. Each PID part is
It consists of 32 bits (4 bytes) of information. These bits are shown as b31 to b0, and b31 is the most significant bit (MS
B) and b0 are the least significant bits (LSB).

Of the bits b31 to b0 constituting the PID section, 8 bits (1 byte) b31 to b24 are sector information, that is, a portion in which information on a sector is recorded. The 24 bits (3 bytes) b23 to b0 are a part in which information on a sector number, that is, information on a sector address is recorded.

The contents of the sector information will be described below. b
31 and b30 are reserved (Reserved), for example, 00b is recorded for the time being, and is a portion to be prepared for recording some information in the future. Note that the letter b after the number 00 in the above 00b is an abbreviation of binary and indicates that it is a binary number. b29 and b28 indicate the physical ID numbers. 00b is recorded for one PID, 01b for two PIDs, 10b for three PIDs, and 11b for four PIDs.

B27 to b25 indicate a sector type, which is 000b for a read-only sector, 100b for a writable first sector, 101b for a writable last sector, and one of last sectors. 110 if the previous writable sector
b, if it is another sector, 111 is recorded. Note that 001b to 011b are reserved.

Here, the read-only sector refers to a sector in the case where the data portion is also constituted by emboss, such as a lead-in area portion. The first sector is a sector where the tracking polarity switches from the groove to the land or from the land to the groove as described above. Further, the last sector indicates a sector immediately before the first sector.

In the example of FIG. 5, 30000h, 3
The sectors indicated by the sector addresses 0011h, 30022h, 30033h,... Are writable first sectors. Also, 30010h, 3002
The sector indicated by the sector addresses 1h, 30032h, 30043h,... Is the writable last sector. Furthermore, 3000Fh, 30020h, 3
The sectors indicated by the sector addresses 0031h, 30042h,... Are writable sectors immediately preceding the last sector.

The rewritable first sector timing for which the tracking polarity needs to be switched can be generated from the sector type bit indicating the sector type. That is, the header
By reading the PID part, the sector type is determined,
The tracking polarity is switched according to the determined sector type. Even when the first sector cannot be detected, the switching polarity is generated by generating the switching timing from the last sector immediately before this sector or the writable sector immediately before this last sector, and switching the tracking polarity. Is possible.

In the detection of the first sector accompanying the detection of the timing of switching the tracking polarity, FIG.
As shown in (b), a 2-byte IED part is added to enable error detection. Therefore, the rewritable first sector can be detected with high reliability, and stable switching of the tracking polarity can be realized in a single spiral disk.

A PID consisting of one part of PID and two parts of PID
The PID part consisting of the first half PID part, the three PID parts and the four PID parts is defined as the second half PID part, and the value of the sector address recorded in the first half PID part is compared with the value of the sector address recorded in the second half PID part. Thereby, it can be used for switching the tracking polarity.

That is, for example, for a (30000h) groove sector recording section, the first half header section is (30011h) header section and the second half header section is (30000h).
0000h) Header section. Here, the first half header section (30011h) has a sector address 3 in the header section.
The first half PID section in which 0011h is recorded is provided.
The second half PID (30000h) has a second half PID in which a sector address 30000h is recorded.
Part is provided.

[0130] The sector address 30011h recorded in the first half PID portion is larger than the sector address 30000h recorded in the second half PID portion. This relationship is
This is true for all the groove sectors having the configuration shown in FIG. Therefore, by irradiating the header portion with a light beam, the sector address of the first half PID portion and the sector address of the second half PID portion are read, and these sector address values are compared, and the sector address of the first half PID portion is larger. In this case, the recording section to which the light beam is subsequently irradiated can be determined as the recording section of the groove sector, and can be used for switching the tracking polarity.

On the other hand, the same applies to the case of a land sector.
For example, for the (30011h) land sector recording section, the first half header section is the (30011h) header section and the second half header section is the (30022h) header section. Here, the first half header part (30011h)
The first half PID section in which the sector address 30011h is recorded is provided in the header section. Also, the sector address 3
The latter half PID section in which 0022h is recorded is provided.

The sector address 30011h recorded in the first half PID is smaller than the sector address 30022h recorded in the second half PID. This relationship is
This is true for all land sectors having the configuration shown in FIG. Therefore, by irradiating the header part with a light beam, the sector address of the first half PID part and the sector address of the second half PID part are read out, the values of these sector addresses are compared, and the sector address by the first half PID part is smaller. In this case, the recording section to which the light beam is subsequently irradiated can be determined as the recording section of the land sector, and can be used for switching the tracking polarity.

Here, a description will be given of a case where the switching of the tracking polarity is not successfully performed, or a case where the track is automatically held in a certain track without intentionally switching the tracking polarity. .

For example, in the first sector shown in FIG. 5, when tracing by a light beam is performed from the (30021h) land sector recording section to the (30022h) groove sector recording section, normally, as described above, (30021h) In the land sector recording section, the track center of the land track is traced by the spot of the light beam. Also, (30033h) header section and (30022h)
In the staggered header section including the header section, the light beam is traced along the center line between the header sections. Further, in the (30022h) groove sector recording section, first, after the tracking polarity is switched from land to groove, the track center of the groove track is traced by the spot of the light beam.

At this time, if the tracking polarity has not been switched from land to groove even after the light spot has passed through the staggered header section, (30011h)
Land sector recording unit or (3003
3h) Tracking control is performed so that the spot of the light beam traces to one of the land sector recording units, and the track deviates from a normal track following state. In this case, the tracking control of the light spot is unpredictable due to various factors such as the state of the disk eccentricity and the state of the track offset at that time.

Therefore, when the spot of the light beam follows the track, a track offset that does not impair the recording / reproducing characteristics is intentionally applied. That is, when following a spiral land track and groove track from the inner peripheral side to the outer peripheral side with a light beam spot, a position slightly closer to the inner peripheral side of the disc than the track center of the land track and the groove track. Trace by beam spot.

In this way, if the tracking polarity is not switched as described above, (3
0021h) From the land sector recording section via the staggered header section, (30011h)
Tracking control is performed on the recording unit. After this tracking control, the (30011h) land sector
The land track is followed by the light beam for one round of the track from the recording unit, and again (30021)
h) It will be returned to the land sector recording unit.

Therefore, by intentionally applying a slight track offset that does not impair the recording / reproducing characteristics to the inner peripheral side of the disc, the 30011
h, 30012h, ..., 30020h, 30021h,
30011h,... Can be traced in the order of the sector address represented by the sector address while keeping the spot of the light beam on the same track. If the tracking polarity is not switched, or the tracking polarity is switched. Even when the tracking control is not performed properly, it is possible to prevent a large deviation from normal tracking control.

In FIG. 5, an embossed data area is shown on the inner peripheral side of the disc with respect to the rewritable data area having the above-mentioned staggered header structure.
The emboss data area is a read-only data area, and data is recorded in a sector format on a read-only disk, not in a sector format with a rewritable staggered header structure. In this emboss data area, data is recorded by embossing composed of uneven pits. It should be noted that a coupling area composed of a mirror surface (mirror) is provided between the emboss data area and the rewritable data area.

In such an emboss data area, for example, a reference signal, physical format information, disc manufacturing information, disc supplier information, etc. are recorded, and the information can be read out by a read-only player conventionally used. Use it as an important lead-in area. In this way, even when information recorded in the sector format using the staggered header cannot be read by the conventional read-only player, disc identification can be easily performed.

Further, it is preferable that the so-called zone CLV system or zone CAV system be used for an optical disk by land / groove recording having a staggered header portion as described above.

That is, by adopting a single spiral structure having a staggered header portion, as described above, it is possible to increase the recording capacity by recording information on lands and grooves, and to shorten the recording time over the entire surface of the disk. It is possible to access with. On the other hand, the zone CLV system or the zone CAV system is suitable for performing high-speed access because the rotation speed control of the spindle motor can be simplified. Therefore, when this zone CLV system or zone CAV system is used in combination with the single spiral structure having the above-mentioned staggered header portion, it is possible to further improve the access speed.

As shown in FIG. 6, for example, in the zone CLV system, the disk surface of the optical disk 1 is divided into a plurality of annular zones Z0, Z1,..., Z23. In each of the divided annular zones, information is recorded in a single spiral sector format having the above-described staggered header portion. The disk speed is switched for each of the divided zones to control the linear velocity on the disk surface to be substantially constant. In each zone, information can be read at a substantially constant linear speed by relatively simple speed change control that controls the disk speed to be substantially constant, so that high-speed access can be performed. it can.

However, when recording or reproduction is performed across zones, it is necessary to change the rotation speed of the spindle motor. For example, when there is a sector that cannot be reproduced due to a defect in the recording surface in a certain zone, and a spare area (that is, a spare area) for recording information to be written in the sector is not in the same zone. Is
Recording and playback must be performed across zones,
It is necessary to change the rotation speed of the spindle motor.

Changing the motor speed requires a long time to stabilize the speed, which results in a longer data access time. In order to eliminate such adverse effects, a spare area is provided in each zone. For example, in the 24 divided zones, that is, the zones Z0, Z1,..., Z23, the spare areas S0, S1,.
, S23 are provided.

[0146]

[Table 1]

In Table 1, zone numbers 0, 1,.
Reference numeral 3 corresponds to the above-mentioned zones Z0, Z1,..., Z23, and indicates the specifications of each zone. The number of sectors indicates the number of sectors per track round.
When it moves outward, it increases by one. The first sector number is the sector number of the first sector of each zone, that is, the sector address expressed in hexadecimal. The inner buffer area sector number indicates the sector number of the buffer area provided on the inner peripheral side of each zone. Note that the buffer area is an area provided at the boundary between zones,
No data recording is performed. The data area sector number indicates a sector number of an area where user data can be recorded. When calculating the disk capacity, the data amount of this area is integrated. The number of data blocks is ECC blocks (16 physical sectors) in the area where user data can be recorded.
Is shown in decimal notation.

The spare sector number indicates the sector number of the spare sector in the spare area of each zone in hexadecimal. As can be seen from Table 1, since the sector having the larger sector number is provided on the outer peripheral side of the disk, the above-described spare area is provided on the outer peripheral side of each zone. The number of spare sectors is the number of sectors in the spare area expressed in decimal.

The sector number of the outer buffer area is
It shows the sector number of the buffer area provided on the outer peripheral side of each zone. The last sector number indicates the last sector number of the zone in hexadecimal. The LBA head sector number is a decimal number representing the head number of a logical block address (that is, a number obtained by adding a continuous number to a sector excluding a buffer and a spare area). The data area number of the first sector is 1 in the LBA first sector number.
Hexadecimal offset of 31000h, ie 1
This is a hexadecimal number with 200704 added as a 0-base number.

As described above, according to the embodiment of the present invention, the spare area is provided for each zone, and the replacement process can be performed without changing the disk rotation speed. Therefore, the data access time can be reduced. Can be. Further, as a preferred embodiment of the specifications shown in Table 1, each zone is defined as 1 zone.
It is composed of 888 tracks. In this case, there is no change in the number of rotations of the disk at the time of performing the replacement process.
It only requires a track seek.

[0151]

Since the optical disk device according to the present invention has the above-described configuration, it has a large recording capacity, enables high-speed access to desired data, and enables continuous access. It is possible to record and reproduce data accurately and at high speed with respect to an optical disc for recording and reproduction which enables highly reliable recording and reproduction of data.

[Brief description of the drawings]

FIG. 1 is a diagram schematically showing a configuration of a header section in a sector of a recording / reproducing optical disk according to an embodiment of the present invention.

FIG. 2 is a diagram showing a master recording apparatus for recording irregularities corresponding to grooves and pits on a master by cutting when manufacturing the recording / reproducing optical disc according to the embodiment of the present invention.

FIG. 3A is a diagram showing the entire structure of a sector on the recording / reproducing optical disk according to the embodiment of the present invention, and FIG. 3B is a diagram showing the header of the sector in more detail;

FIG. 4 is a block diagram showing an overall configuration of an optical disk device for recording and reproducing information on and from the optical disk for recording and reproduction according to the embodiment of the present invention.

FIG. 5 is a diagram schematically illustrating a staggered header portion and a structure around the header portion according to the embodiment of the present invention.

FIG. 6 is a schematic diagram when the recording / reproducing optical disk according to the embodiment of the present invention is divided into a plurality of annular zones.

[Explanation of symbols]

Recording field, 30000h, 30001h, ...: Recording part RF1 to RF4, R1, R2, 30011h to 30021h, 30033h to 30043h,
…: Land sector (first) recording section RF6 to RF9, R5 to R8, 30000h to 30010h, 30022h to 30032
h, ...: (second) recording section of the groove sector Header field, 30000, 30001, ...: header section HF1, HF3, H1, H3, 30011-30021, 30033-30043, ...:
First half header section HF2, HF4, H2, H4, 30000-30010, 30022-30032,…:
2nd half header section PID1, PID2: PID section P: track pitch, Z0 to Z23: annular zone (sector area), S0 to S23: spare area (alternate area), 1: optical disk, 3: disk motor, 4: motor control circuit , 5:
Optical pickup, 6: linear motor, 8: linear motor control circuit, 10: objective lens, 13: laser control circuit
Part , 14: modulation circuit, 15: laser control circuit , 16: PL
L circuit, 19: semiconductor laser oscillator (light irradiation means), 2
4: photodetector (light detection means), 27: focusing control circuit, 28: tracking control circuit (position control means), 30: CPU

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-10-11763 (JP, A) JP-A-10-11759 (JP, A) JP-A-9-147393 (JP, A) JP-A 9-107 265631 (JP, A) JP-A-9-282669 (JP, A) JP-A-10-11764 (JP, A) JP-A-11-3571 (JP, A) (58) Fields investigated (Int. Cl. ^7, DB name) G11B 7/09 G11B 7/095 G11B 7/007

Claims (8)

(57) [Claims] A light irradiating means for irradiating the optical disk with a light beam; and a light detecting means for detecting a change in an optical characteristic of light reflected from the optical disk by irradiating the light beam with the light irradiating means. An optical disc apparatus having a position control means for controlling an irradiation position of a light beam so as to irradiate a predetermined position on the optical disc with a light beam based on a change in an optical characteristic of the reflected light detected by the light detection means. Wherein the optical disc is formed adjacent to the first recording section, which is a land-shaped area where data is recorded and reproduced, and performs recording and reproduction of data. The second, which is a groove-shaped region
, A first-half header section in which address information corresponding to the first recording section is recorded, and address information corresponding to the second recording section, and are paired with the first-half header section. An optical disk in which a rear half header portion arranged in a spiral shape is arranged along a spiral track, and along the spiral track in which the first recording portion and the second recording portion of the optical disc are arranged. When the light beam is made to follow, the light beam is shifted from the track center of the spiral track by a predetermined amount.
An optical disc device , wherein a control target of the position control means is determined so as to irradiate light . A light irradiating means for irradiating the optical disk with a light beam; and a light detecting means for detecting a change in an optical characteristic of light reflected from the optical disk by irradiating the light beam with the light irradiating means. An optical disc apparatus having a position control means for controlling an irradiation position of a light beam so as to irradiate a predetermined position on the optical disc with a light beam based on a change in an optical characteristic of the reflected light detected by the light detection means. Wherein the optical disc is formed adjacent to the first recording section, which is a land-shaped area where data is recorded and reproduced, and performs recording and reproduction of data. The second, which is a groove-shaped region
, A first-half header section in which address information corresponding to the first recording section is recorded, and address information corresponding to the second recording section, and are paired with the first-half header section. An optical disk in which a rear half header portion arranged in a spiral shape is arranged along a spiral track, and along the spiral track in which the first recording portion and the second recording portion of the optical disc are arranged. When the light beam is made to follow the first radial direction side of the optical disk from the first radial direction side to a position shifted from the track center of the spiral track toward the first radial direction side of the optical disk. An optical disc device, characterized in that the position control means controls to irradiate a light beam. 3. Light irradiating means for irradiating an optical disk with a light beam, and light detecting means for detecting a change in optical characteristics of light reflected from the optical disk by irradiating the optical beam with the light irradiating means. An optical disc apparatus having a position control means for controlling an irradiation position of a light beam so as to irradiate a predetermined position on the optical disc with a light beam based on a change in an optical characteristic of the reflected light detected by the light detection means. Wherein the optical disc is formed adjacent to the first recording section, which is a land-shaped area where data is recorded and reproduced, and performs recording and reproduction of data. The second, which is a groove-shaped region
, A first-half header section in which address information corresponding to the first recording section is recorded, and address information corresponding to the second recording section, and are paired with the first-half header section. An optical disk in which a rear half header portion arranged in a spiral shape is arranged along a spiral track, and along the spiral track in which the first recording portion and the second recording portion of the optical disc are arranged. The position control means for irradiating the light beam to a position shifted from the track center of the spiral track toward the inner circumference side of the optical disk when the light beam follows from the inner circumference side to the outer circumference side of the optical disk. An optical disk device controlled by: A light irradiating means for irradiating the optical disk with a light beam; a light detecting means for detecting a change in an optical characteristic of light reflected from the optical disk by the light irradiating means; An optical disc apparatus having a position control means for controlling an irradiation position of a light beam so as to irradiate a predetermined position on the optical disc with a light beam based on a change in an optical characteristic of the reflected light detected by the light detection means. Wherein the optical disc is formed adjacent to the first recording section, which is a land-shaped area where data is recorded and reproduced, and performs recording and reproduction of data. The second, which is a groove-shaped region
, A first-half header section in which address information corresponding to the first recording section is recorded, and address information corresponding to the second recording section, and are paired with the first-half header section. An optical disk in which a rear half header portion arranged in a spiral shape is arranged along a spiral track, and along the spiral track in which the first recording portion and the second recording portion of the optical disc are arranged. The position control means for irradiating the light beam to a position shifted from the track center of the spiral track toward the inner circumference side of the optical disk when the light beam follows from the inner circumference side to the outer circumference side of the optical disk. , A certain track at a predetermined radial position is controlled.
Track-hold operation to repeatedly irradiate the light
An optical disc device characterized in that the operation is performed automatically . 5. A light irradiating means for irradiating a light beam to an optical disk, and a light detecting means for detecting a change in an optical characteristic of light reflected from the optical disk by irradiating the light beam with the light irradiating means. An optical disc apparatus having a position control means for controlling an irradiation position of a light beam so as to irradiate a predetermined position on the optical disc with a light beam based on a change in an optical characteristic of the reflected light detected by the light detection means. The optical disc is a land-shaped area in which data is recorded and reproduced, and a first recording unit disposed on a spiral track; and a recording and reproduction with respect to the first recording unit. And a first half header portion arranged prior to the first recording portion, and a land sector comprising: A second recording section disposed on the spiral track, a predetermined number of sections being arranged along one circumference of the spiral track, and a groove-shaped area in which data recording and reproduction are performed; And address information of data to be recorded and reproduced with respect to the second half of the header. The second half of the header is arranged prior to the second recording part and in a staggered manner with the first half of the header. After a predetermined number of groove sectors are arranged along the circumference of the spiral track, a predetermined number of groove sectors are continuously arranged along the circumference of the spiral track. After a predetermined number of sectors are arranged along the circumference of the spiral track, a predetermined number of sectors are continuously arranged along the circumference of the spiral track. An optical disk having a configuration in which a land sector and the groove sector are alternately and continuously switched for each rotation of the spiral track, wherein the land sector and the groove sector of the optical disk are arranged along the spiral track. When following the light beam,
The spiral track is shifted from the track center by a predetermined amount.
In order to irradiate the position with a light beam, the control
An optical disc device characterized by defining a mark . 6. Light irradiating means for irradiating an optical disk with a light beam, and light detecting means for detecting a change in optical characteristics of reflected light reflected from the optical disk by irradiating the optical beam with the light irradiating means. An optical disc apparatus having a position control means for controlling an irradiation position of a light beam so as to irradiate a predetermined position on the optical disc with a light beam based on a change in an optical characteristic of the reflected light detected by the light detection means. The optical disc is a land-shaped area in which data is recorded and reproduced, and a first recording unit disposed on a spiral track; and a recording and reproduction with respect to the first recording unit. And a first half header portion arranged prior to the first recording portion, and a land sector comprising: A second recording section disposed on the spiral track, the groove being a groove-shaped area in which a predetermined number of data are arranged along one circumference of the spiral track and data is recorded and reproduced; A second-half header portion arranged in a staggered manner before the second recording portion and in pairs with the first-half header portion. After a predetermined number of the groove sectors are arranged along the circumference of the spiral track, a predetermined number of the groove sectors are continuously arranged along the circumference of the spiral track. After a predetermined number of groove sectors are arranged along the circumference of the spiral track, a predetermined number of groove sectors are continuously arranged along the circumference of the spiral track. An optical disc having a configuration in which the land sector and the groove sector are alternately and continuously switched for each rotation of the spiral track, and the land sector and the groove sector of the optical disc are arranged along the spiral track. When the light beam is made to follow the first radial direction side of the optical disk from the first radial direction side to a position shifted from the track center of the spiral track toward the first radial direction side of the optical disk. An optical disc device, characterized in that the position control means controls to irradiate a light beam. 7. Light irradiating means for irradiating an optical disk with a light beam, and light detecting means for detecting a change in optical characteristics of reflected light reflected from the optical disk by irradiating the optical beam with the light irradiating means. An optical disc apparatus having a position control means for controlling an irradiation position of a light beam so as to irradiate a predetermined position on the optical disc with a light beam based on a change in an optical characteristic of the reflected light detected by the light detection means. The optical disc is a land-shaped area in which data is recorded and reproduced, and a first recording unit disposed on a spiral track; and a recording and reproduction with respect to the first recording unit. And a first half header portion arranged prior to the first recording portion, and a land sector comprising: A second recording section disposed on the spiral track, the groove being a groove-shaped area in which a predetermined number of data are arranged along one circumference of the spiral track and data is recorded and reproduced; A second-half header portion arranged in a staggered manner before the second recording portion and in pairs with the first-half header portion. After a predetermined number of the groove sectors are arranged along the circumference of the spiral track, a predetermined number of the groove sectors are continuously arranged along the circumference of the spiral track. After a predetermined number of groove sectors are arranged along the circumference of the spiral track, a predetermined number of groove sectors are continuously arranged along the circumference of the spiral track. An optical disc having a configuration in which the land sector and the groove sector are alternately and continuously switched for each rotation of the spiral track, and the land sector and the groove sector of the optical disc are arranged along the spiral track. When the light beam follows from the inner circumference to the outer circumference of the optical disc, the light beam is irradiated to a position shifted from the track center of the spiral track to the inner circumference of the optical disc,
An optical disc device controlled by the position control means. 8. Light irradiating means for irradiating an optical disk with a light beam, and light detecting means for detecting a change in optical characteristics of light reflected from the optical disk by irradiating the optical beam with the light irradiating means. An optical disc apparatus having a position control means for controlling an irradiation position of a light beam so as to irradiate a predetermined position on the optical disc with a light beam based on a change in an optical characteristic of the reflected light detected by the light detection means. The optical disc is a land-shaped area in which data is recorded and reproduced, and a first recording unit disposed on a spiral track; and a recording and reproduction with respect to the first recording unit. And a first half header portion arranged prior to the first recording portion, and a land sector comprising: A second recording section disposed on the spiral track, a predetermined number of sections being arranged along one circumference of the spiral track, and a groove-shaped area in which data recording and reproduction are performed; And address information of data to be recorded and reproduced with respect to the second half of the header. The second half of the header is arranged prior to the second recording part and in a staggered manner with the first half of the header. After a predetermined number of groove sectors are arranged along the circumference of the spiral track, a predetermined number of groove sectors are continuously arranged along the circumference of the spiral track. After a predetermined number of sectors are arranged along the circumference of the spiral track, a predetermined number of sectors are continuously arranged along the circumference of the spiral track. An optical disk having a configuration in which a land sector and the groove sector are alternately and continuously switched for each rotation of the spiral track, wherein the land sector and the groove sector of the optical disk are arranged along the spiral track. When following the light beam from the inner circumference side to the outer circumference side of the optical disc, irradiating the light beam to a position shifted from the track center of the spiral track to the inner circumference side of the optical disc,
By controlling by the position control means, a predetermined
The light beam traverses one track at a radial position.
An optical disc device wherein a track-hold operation for returning irradiation is automatically performed .