JPH1027349A - Optical recording medium, its manufacture and optical information recording/reproducing device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high quality information signal by preventing the infiltration of meandering frequency components and easily constituting a sector system in an optical disk for performing recording in a groove or a land. SOLUTION: An optical disk 1 includes an address recording part 24 in which only a part of one side wall of a groove 21 meanders. The address recording part 24 includes a plurality of projecting parts formed in a land side 22 so as to have a wider groove 21. Address information is recorded by the meandering of such recessed and projecting shapes. Also, address recording parts 24 formed in the grooves 21 are aligned in the radial direction of the optical disk 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical recording medium for recording / reproducing a signal using light, a method for manufacturing the same, and an optical information recording / reproducing apparatus using the optical recording medium.

[0002]

2. Description of the Related Art An optical recording medium for recording or reproducing a signal using light has been rapidly developed in recent years. In particular, attempts to improve the recording capacity have been made vigorously,
Various element technologies for this purpose have been devised.

[0003] Among them, a so-called optical disk in which recording is performed on a disk-shaped medium has a configuration in which a recording medium layer is mainly formed on a substrate on which tracks are formed in advance. In this case, by tracking the light spot along the track, the light spot can be accurately tracked on a fine recording mark row.

When forming a track on a substrate, in the case of an optical disk, address information of the track is formed on the track in advance. That is, track numbers and sector numbers are formed on or between tracks in the form of pits, and these are read to obtain address information.

As another method of giving address information, there is a method of wobbling a groove. This means that, as shown in FIG. 13, the side wall of the groove 101 (also the side wall of the land 102) formed on the optical disk meanders in a direction perpendicular to the longitudinal direction of the track, and the meandering frequency is modulated by some method. In this method, address information is added thereto. At this time,
If the meandering frequency is set to a frequency higher than the frequency at which the light spot can be tracked, the light spot does not follow the meandering frequency even when tracking, and the meandering frequency component is added to the tracking signal. As a result, address information can be obtained.

Incidentally, there is a land / groove recording method as a method for increasing the capacity of an optical disk. In this method, a signal is recorded on only one of the groove and the land between the grooves in the related art, but is recorded on both the groove and the land. In this case, in the groove meandering method shown in FIG. 13, the width of the land 102 is two grooves 101 and 101 adjacent to the land 102.
Therefore, the address information cannot be recorded on the land 102 correctly.

To solve this problem, a so-called one-sided wobble system in which only one side of the groove is meandering is disclosed in Japanese Patent Laid-Open No. 5-3 / 1993.
No. 14,538. In an optical disk having a groove 111 and a land 112 as shown in FIG. 14, only one side wall of the groove 111 meanders, and address information is recorded at the meandering frequency.

[0008]

However, in the double-sided wobble method and the single-sided wobble method as described above, the side walls of all the grooves (or lands) on the optical disk meander, that is, always meander during tracking. In order to track the section, when recording or reproducing the information signal, there is a problem that the meandering frequency component is mixed into the reproduced signal of the information and the signal quality is degraded.

Further, since the signal is mixed as described above, it is necessary to set the meandering frequency in a band different from the band of the information signal. Therefore, the meandering frequency must be set to a much lower frequency than the information signal. did not become. Therefore, the spatial wavelength becomes long, and a long section is required to represent the address information, so that there is a problem that the division of the address cannot be accurately represented.

[0010] This is not a problem when signals are continuously transferred as in the case of video and audio signals. However, when using an optical disk as a storage device for a computer, it is necessary to exchange signals frequently,
Signals must be exchanged in blocks. For this reason, it is necessary to configure the data in a so-called sector system, which is problematic in this case.

In addition, as a method of inserting address information when the land / groove recording method is used, as shown in page 168 of Nikkei Electronics November 6, 1995, a dedicated address method and a shared address method are used. is there.

In the dedicated address system, a dedicated pre-pit is provided for each sector of a land and a groove. However, since the width of the pit needs to be sufficiently smaller than the track width, a pre-pit cannot be formed with the same light beam as that for forming the track, and there is a disadvantage that it is difficult to manufacture an optical disk.

In the shared address system, as shown in FIG. 15, a pit row 123 is arranged at a boundary between a groove 121 and a land 122 so that an adjacent groove 121 and a land 122 are arranged.
Is a method of sharing the pit row 123. In this case, even when tracking either the groove 121 or the land 122, since the light spot 124 tracks the position shifted from the pit when reproducing the pit, there is a disadvantage that the signal quality is not good.

Further, the pit row 123 is formed by a light spot 124.
When light passes through, the light spot 124
Since the tracking is not performed on the center line, there is a disadvantage that the tracking signal is greatly offset. Since the pits are formed intermittently, the tracking signal obtained therefrom is also intermittent, but averaging this results in a large offset amount.

Further, since the pit frequency is sufficiently higher than the band of the tracking servo system circuit, the servo system circuit does not respond to the tracking signal itself obtained from each pit. However, since the entire length of the pit area is considerably long,
The servo system circuit responds to the signal of the offset amount obtained by averaging the tracking signal over the entire pit area, and a large spike-like signal is generated when the signal passes through the pit area. The actuator of the tracking servo vibrates in response to the length of the pit area depending on the length of the pit area, causing a transient response and adversely affecting signal recording / reproduction.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems. An object of the present invention is to prevent a meandering frequency component from wrapping around in a land / groove recording system and to easily adopt a sector system configuration. Another object of the present invention is to provide an optical recording medium capable of providing an information signal with high signal quality, a method for manufacturing the same, and an optical information recording / reproducing apparatus using the same.

[0017]

According to a first aspect of the present invention, there is provided an optical recording medium, comprising: a light beam for a track formed of lands or grooves which are grooves between lands; In an optical recording medium for recording, reproducing, or erasing information by irradiating light, only one side wall of the groove or the land has a meandering portion.

According to the above configuration, if information is recorded on a groove or a land other than the portion where the meandering portion is formed, the meandering signal of the meandering portion is mixed with the information signal when the information is reproduced, and the signal quality is reduced. Is not reduced, so that a high-quality information signal can be obtained.

If the address information is recorded by meandering of the meandering portion, the address signal can be reliably detected without affecting the information signal when recording, reproducing, or erasing the signal.

The optical recording medium according to the second aspect is the first aspect.
In addition to the above configuration, the optical recording medium is an optical disk, and the meandering portions formed on each track of the optical disk are formed in a radial direction of the optical disk.

According to the above configuration, since the meandering portions are aligned in the radial direction of the optical disk, the portions for recording information other than the meandering portions are also aligned in the radial direction. Therefore,
The timing for detecting the address signal can be accurately set, the address signal can be reliably detected even when accessing another track, and high-speed access can be performed.

The optical recording medium according to the third aspect is the first aspect.
In addition to the configuration described in the above, the optical recording medium is an optical disk, the meandering portion formed on the track of the optical disk,
It is characterized in that it is formed at a different position in the radial direction of the optical disc from the meandering part formed on the adjacent track.

According to the above configuration, the address portions can be arranged on the inner and outer circumferences of the optical disc according to the linear velocity, the recording density on the inner and outer circumferences can be kept almost constant, and the recording capacity can be increased. It is.

An optical information recording / reproducing apparatus according to claim 4 is
An optical recording medium according to any one of claims 1 to 3, light detecting means for detecting reflected light obtained by irradiating the optical recording medium with a light beam, and tracking based on a signal from the light detecting means. A calculating means for detecting a signal and extracting a meandering frequency component due to a meandering portion of a groove or a land included in the tracking signal.

According to the above arrangement, a tracking signal can be obtained by irradiating the optical recording medium with a light beam. By extracting the meandering frequency component included in the tracking signal, the meandering signal can be detected without affecting the information signal.

An optical information recording / reproducing apparatus according to claim 5 is
An optical recording medium according to any one of claims 1 to 3, light detection means for detecting a reflected light amount obtained by irradiating the optical recording medium with a light beam, and detecting a change in the reflected light amount. Calculating means for extracting a meandering frequency component due to the meandering portion of the groove or the land.

According to the above configuration, when the width of the groove or the land changes, the amount of reflected light changes due to the diffraction effect. Therefore, the meandering frequency component can be extracted by detecting the amount of reflected light. Therefore, it is not necessary to provide a high-speed response to the detection system for detecting the tracking signal, and it is possible to configure an inexpensive detection system.

According to a sixth aspect of the present invention, there is provided a method of manufacturing an optical recording medium, wherein a light beam is applied to a track comprising lands or grooves which are grooves between lands.
In an optical recording medium for recording, reproducing, or erasing information, a method for manufacturing an optical recording medium having a meandering portion in which only a part of one side wall of the groove or the land is meandering, wherein a photosensitive material is formed on a substrate. In the step of applying and forming the meandering portion, at least two light beams are separated in a direction orthogonal to the longitudinal direction of the track, and one of the light beams is irradiated while being vibrated in the orthogonal direction. And exposing the photosensitive material to light.

According to the above method, the amplitude of the meandering portion can be freely controlled by changing the amount of movement in the direction orthogonal to the longitudinal direction of the track, so that the shape of the meandering portion can be freely controlled. is there. Therefore, it is possible to easily form a meandering portion in which only a part of one side wall of the groove or the land is meandering.

[0030]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. An optical information recording / reproducing apparatus according to the present embodiment will be described. As shown in FIG. 2A, the optical information recording / reproducing apparatus includes an optical disk (optical recording medium) 1 and a detection system for reproducing information recorded on the optical disk 1.

The light beam emitted from the semiconductor laser 2 is
The light is collimated by the collimator lens 3, passes through the beam splitter 4, and is focused on the optical disc 1 by the objective lens 5. The reflected light from the optical disc 1 returns to the beam splitter 4 via the objective lens 5, is deflected by the beam splitter 4, and enters the beam splitter 6.
The reflected light is split into two by the beam splitter 6, and one of the two is condensed on a photodetector (photodetector) 9 via a condenser lens 7 and a cylindrical lens 8.

As shown in FIG. 2B, the photodetector 9
It is a servo detector having divided light receiving surfaces 9a, 9b, 9c, 9d, and each light receiving surface is provided with an arithmetic circuit (arithmetic means) 1
Connected to 0. At this time, the light receiving surfaces 9a, 9b, 9
The light spot formed on c · 9d changes into an elliptical shape by the cylindrical lens 8 according to the amount of defocus.
Therefore, assuming that the signal amounts obtained on the light receiving surfaces 9a, 9b, 9c, and 9d are A, B, C, and D, the arithmetic circuit 10 calculates the signal amount of A + D- (B + C) to obtain the focus error signal. Can be

Assuming that the direction (arrow direction) from the light receiving surface 9c to the light receiving surface 9a in FIG. 2B corresponds to the track direction, the track error signal can be calculated by A + C- (B + D). This calculation is also performed by the calculation circuit 10. The track on the optical disk 1 is tracked based on the tracking signal based on the track error signal.

On the other hand, the remaining reflected light which is not transmitted and reflected by the beam splitter 6 is applied to the polarization beam splitter 12 via the condenser lens 11 and is divided into two by the polarization beam splitter 12 to be respectively divided. The light is condensed on light detectors (light detecting means) 13 and 14. Photodetector 13
The information recorded on the optical disk 1 is obtained as a magneto-optical signal (information signal) by performing the differential reproduction of the output from 14 by the operational amplifier 15.

The reflected light from the optical disk 1 is the sum of the light amounts of the four-divided elements of the photodetector 9 (= A + B + C +
D) or a photodetector 1 for detecting a magneto-optical signal
Amplifier for calculating the sum of outputs from 3.14 (arithmetic means)
16 can be detected.

The configuration of the optical information recording / reproducing apparatus is merely an example, and an equivalent function can be realized using various optical components.

FIG. 1 shows the structure of the optical disc 1 having an address recording section (meandering section) 24 which is a characteristic part of the present invention.
Shown in The optical disc 1 includes a groove 21 and a land 22.
The track comprises a transparent substrate 20 formed concentrically or spirally, and a recording medium layer 23 for recording information signals on the transparent substrate 20.

The light beam converged by the objective lens 5 forms light spots S ₁ and S ₂ on the land 22 or the groove 21. That is, the light spot S ₂ by the light beam tracks the groove 21, and the light spot S ₁ tracks the land 22.

As the recording medium layer 23, a material such as a rare earth-transition metal alloy for performing magneto-optical recording or a phase change material for recording a signal by a crystal-amorphous phase transition due to a temperature change is used. be able to. The recording medium layer 23 formed of these materials can exhibit a so-called super-resolution effect due to its configuration, and can reproduce a recording mark smaller than the size of the light spot. As a result, even if recording is performed on both the groove 21 and the land 22, the signals can be reproduced without crosstalk between the signals. Therefore, it is possible to increase the recording density by recording the information signal on both the groove 21 and the land 22.

An address recording section 24 is provided on a part of one side wall of the groove 21 (which is also a side wall of the land 22), which is a boundary between the groove 21 and the land 22. As shown in FIG. 4 which is a plan view of FIG. 1, the address recording unit 24 includes a plurality of convex portions 2 which are convex toward the land 22 side.
4a is formed, and as a result, the side wall of the groove 21 is formed so as to meander in an uneven manner in the radial direction of the optical disc 1. That is, the groove width of the groove 21 is the protrusion 24a.
It is wide. Address information is recorded by such meandering of the side wall. Here, the frequency of the change in the width of the side wall of the address recording unit 24 (meandering frequency) is set higher than the response frequency of the tracking servo system.

Each address recording section 24 formed in each groove 21 is formed so as to be aligned with each other in the radial direction of the optical disc 1. That is, by arranging the address recording sections 24, an area 26 as shown in FIG. 3 is formed. This area 26 has one or more locations,
They are arranged radially. The information recording unit 25 is provided in an area between the areas 26. Therefore, when one track is viewed, tracking is performed alternately in the region 26 (address recording unit 24), the information recording unit 25, the region 26, the information recording unit 25, and so on.

When the address recording units 24 are discretely arranged in this manner, the information recording unit 2 following the address recording unit 24
5 is configured as one unit (so-called sector configuration), which is suitable for a memory for a computer that frequently exchanges information. That is, the timing for detecting the address signal can be accurately set, the address signal can be reliably detected even when accessing another track, and high-speed access can be performed. The number of areas 26 may be set according to the purpose of use.

Here, as shown in FIG. 3, each address recording section 24 is arranged on the same radius to form the area 26. However, as shown in FIG. It is also possible to form them at different positions in the radial direction of the optical disc. That is, the address recording portions 54 formed on the side walls of the groove 51 (also the side walls of the lands 52) are not arranged on the same radius.

Such a structure is advantageous in that the CLV
(Constant Line Velosity; constant line speed), ZCAV (Zo
ned Constant Angular Velosity;
Alternatively, the present invention can be applied to a format such as ZCLV (Zoned Constant Line Velosity). That is, since the present invention can be applied to a format in which the address recording units are not arranged at a certain position in the radial direction, the address recording units can be arranged according to the linear velocity on the inner and outer peripheries of the optical disc. Recording density can be kept close to a constant. As a result, it is possible to increase the recording capacity of the optical disc.

In the configuration of FIG.
The address signal is recorded by changing the width of the groove in the address recording unit 24 so that the address signal is recorded by changing the width of the groove so as to decrease in the address recording unit. It may be. That is, as shown in FIG. 5, in the optical disc having the groove 31 and the land 32, the width of the land 32 may be changed so as to be wider in the address recording section 34.

As shown in FIG. 6, in an optical disk having a groove 41 and a land 42, the groove 41
An address recording unit 44 having both a meandering amplitude toward the side and a meandering amplitude toward the land 42 may be provided. That is, the protrusion 41a and the recess 41b are formed on the side wall of the groove 41. Here, as shown in FIG. 7, the land 4 is formed so that the width of the groove 41 is increased in the convex portion 41a.
The amplitude 41a changes to the second side, and the groove 41 in the concave portion 41b.
Is changed by the amplitude b toward the groove 41 so that the width of the groove 41 becomes narrower. In FIG. 6, it is needless to say that the groove 41 and the land 42 may be reversed, and that 41 may be a land and 42 may be a groove.

FIG. 8 shows how signals are reproduced from the address recording section 44 shown in FIG.

The light spot S on the center line C ₁ that connects two division points of the width of the groove 41 is tracking a light spot S is moved in the arrow direction in relatively diagram. The tracking signal obtained at this time is as shown in FIG. That is, since tracking is performed by the tracking servo system, the track error signal becomes substantially 0 in portions other than the address recording section 44, but changes in the address recording section 44 according to the change in the width of the side wall.

This is because the meandering frequency of the address recording unit 44 is set higher than the response frequency of the servo system. Therefore, when the address recording unit 44 is tracked, the servo system does not respond to the meandering frequency, and the tracking error signal is generated. Because it occurs. That is, the light spot S is in tracking the address recording part 44, not on the center line C _1, traces the center line connecting the almost two division points of the average width of the address recording part 44.

Here, the amplitude of the tracking signal in the address recording section 44 is converted to a track width by a / a on one side.
2, b / 2 on the opposite side. This is because in FIG. 7, since the track width changes are a and b, the deviation of the light spot S from the center position in the address recording unit 44 is の of the width change amount.

At this time, if the DC component of the address signal itself recorded in the address recording unit 44 is 0, and if the geometrical shape of the address recording unit 44 is a = b, the average of the track error signal is obtained. The value becomes 0, indicating that no offset occurs in the track error signal when passing through the address recording unit 44.

In this manner, by extracting the meandering frequency component included in the tracking signal, the address signal can be detected without affecting the information signal.

The address signal may be obtained by detecting a change in the amount of reflected light detected by the photodetector 9 or the photodetectors 13 and 14. FIG. 9 shows the amount of reflected light from the address recording unit 44 shown in FIG.

Normally, when the width of the groove becomes narrow, the amount of reflected light decreases due to the diffraction effect of the groove. Therefore, the amount of reflected light decreases in a portion where the width is narrow, and conversely, the amount of reflected light increases in a portion where the width is wide. Therefore, the change in the amount of reflected light from the address recording unit 44 having the amplitudes a and b as shown in FIG. 7 is as shown in FIG. This makes it possible to obtain the address signal from the address recording unit 44 by detecting the amount of reflected light instead of detecting the track error signal.

In this case, it is not necessary to detect the track error signal at a high speed, and it is not necessary to make the arithmetic circuit 10 of FIG. Normally, the signal band of the servo system depends on the response speed of the actuator machine
It is several hundred kHz or less, and the band of the information signal is several MHz to several tens MHz. For this reason, a detection system for detecting them is also made correspondingly, so that if the detection system of the servo system is to perform high-speed signal detection, the performance becomes excessively high.
Therefore, when an address signal is obtained from the amount of reflected light, only the detector that detects the total amount of light (the photodetectors 13 and 14 in FIG. 2A) needs to be provided with the amplifier 16 that can perform high-speed detection. This has the advantage that the detection system is simplified without excessive quality.

As described above, the optical disc in the present embodiment has a configuration in which only one side wall of a groove or a land has an address recording portion meandering. At this time, if the information signal is not recorded in the address recording unit, the meandering amplitude of the side wall of the address recording unit can be made much larger than the conventional meandering amount. This is because when information is not recorded in the address recording unit, it is not necessary to consider the influence of the meandering signal on the information signal.
This is because the amplitude of the side wall may be increased so that a meandering signal can be sufficiently obtained.

For example, in a conventional optical disk of a meandering groove type, the meandering amplitude needs to be about ± 50 nm or less (this is about 5 to 6% when the groove width is about 0.8 μm). However, in this embodiment, it is not necessary to suppress the amplitude as shown in FIG. 7, and the amplitude is reduced to approximately 50% of the groove width (for example, to approximately 0.4 μm when the groove width is 0.8 μm), as shown in FIG. Can be bigger. The same applies to the address recording units of the formats shown in FIGS.

That is, the meandering amplitude is about 5 to 5 of the groove width.
If it is 0%, the meandering signal can be detected without affecting the information signal. By increasing the meandering amplitude in this way, it is possible to improve the reliability of the signal and reduce the error rate when reproducing the address signal.

On the contrary, the meandering amplitude of the address recording section may be reduced so that the information signal is also recorded in the address recording section. In this case, since the address recording unit can be used as the information recording unit, the recording capacity can be increased.

In the present embodiment, the case where recording is performed on both the groove and the land has been described. However, the configuration may be such that recording is performed on only one of the groove and the land. However, as described above, in order to increase the recording density, it is preferable to record on both the groove and the land.

Next, a method for manufacturing the optical disk substrate of the present embodiment will be described. First, a master (substrate) coated with a photoresist (photosensitive material) is irradiated with a light beam to record a desired pattern such as grooves, lands, and pits on the photoresist. This is developed to remove unnecessary photoresist, and a metal such as nickel is plated to transfer a pattern of the resist to a plating film.

Then, the plating film is removed from the master,
This is a stamper. By using this stamper as a mold and molding plastic, grooves,
An optical disk substrate having a desired pattern such as lands and pits is manufactured. When the recording medium layer is formed on this substrate, the above-mentioned optical disk is obtained.

FIG. 11 shows an example of a recording apparatus for recording a desired pattern on a photoresist.

The recording device has an argon laser 60 for exposing the photoresist on the master 73 to light.
The light beam from the argon laser 60 is applied to a mirror 61
And is incident on the beam splitter 62. The light beam is split into two by a beam splitter 62, one of which is guided to a light modulator 65a via a converging convex lens 64a. The light beam incident on the optical deflector 67a through the optical modulator 65a and the convex lens 66a is a half-wave plate 6
At 8, the polarization plane is rotated by 90 ° and enters the polarization beam splitter 69.

On the other hand, the other of the two light beams split by the beam splitter 62 is a mirror 63 and a convex lens 64.
b, light modulator 65b, convex lens 66b, light deflector 67
b, and a polarizing beam splitter 69 via a mirror 70
Is incident on. Then, the light beams are combined again by the polarization beam splitter 69.

The two light beams are guided to the objective lens 72 via the mirror 71, and form an image on the surface of the master 73 coated with a photoresist. While the master 73 is rotated by the spindle 74, the objective lens 72 is driven in the radial direction of the master 73 (the direction of the arrow in the drawing),
A spiral or concentric track is recorded.

Here, since the light beam is divided into two, recombined and made incident on the objective lens 72, two light spots are formed on the master 73. Also, the optical modulators 6 are provided on the optical paths of the two light beams, respectively.
Since the light deflectors 5a and 65b and the light deflectors 67a and 67b are provided, the light beams can be modulated and deflected.

A method for recording a pattern on the master 73 will be described with reference to FIG. When recording groove 81, in a direction perpendicular two light spots S ₃ · S ₄ in the longitudinal direction of the track (radial direction of the master 73), recorded side by side so as to obtain a desired groove width. Recording in the address recording section 84 is performed as follows. First recorded using only the light spot S ₄ in the portion to narrow the width of the groove 81. On the other hand, in the portion where the width of the groove 81 is widened, two light spots S ₃ and S ₄ are used, and the light spot S ₃ is moved in the radial direction of the master 73 and recorded.
If this is repeatedly recorded based on the address signal,
An address recording section 84 is formed.

[0069] for driving the light spot S ₃ in the radial direction can be performed by using a light deflector 67a (or 67b) in FIG. 11. According to this method, the address recording section 84 on the side wall of the groove 81 or the land 82 is used.
Can be freely controlled. That is, the master 73
The amplitude of the address recording section 84 can be freely controlled by changing the moving amount of the address recording section 84 in the radial direction.

In the present embodiment, an optical disk is described as an optical recording medium. However, the present invention is not limited to this. It goes without saying that the same effect can be obtained by using an optical card or optical tape. No.

[0071]

As described above, the optical recording medium according to the first aspect of the present invention has a structure in which only one side wall of a groove or a land has a meandering portion. As a result, since the meandering signal by the meandering portion is not mixed into the information signal when the information is reproduced, the signal quality is not deteriorated.
There is an effect that a high-quality information signal can be obtained.

The optical recording medium according to the second aspect is the first aspect.
In addition to the above configuration, the optical recording medium is an optical disk, and the meandering portions formed on each track of the optical disk are formed in the radial direction of the optical disk.

As a result, the portions for recording information other than the meandering portions are also aligned in the radial direction, so that the timing of detecting the address signal can be accurately set, and even when accessing another track. This has the effect that the address signal can be reliably detected and high-speed access is possible.

The optical recording medium according to the third aspect is the first aspect.
In addition to the configuration described in the above, the optical recording medium is an optical disk, the meandering portion formed on the track of the optical disk,
In this configuration, a meandering portion formed on an adjacent track is formed at a different position in the radial direction of the optical disc.

As a result, the address portions can be arranged on the inner and outer circumferences of the optical disk according to the linear velocity, the recording density on the inner and outer circumferences can be kept almost constant, and the recording capacity can be increased. To play.

An optical information recording / reproducing apparatus according to claim 4 is
An optical recording medium according to any one of claims 1 to 3, light detecting means for detecting reflected light obtained by irradiating the optical recording medium with a light beam, and tracking based on a signal from the light detecting means. And a calculating means for detecting a signal and extracting a meandering frequency component due to a meandering portion of the groove or land included in the tracking signal.

Thus, there is an effect that the meandering signal can be detected without affecting the information signal.

The optical information recording / reproducing apparatus according to claim 5 is
An optical recording medium according to any one of claims 1 to 3, light detection means for detecting a reflected light amount obtained by irradiating the optical recording medium with a light beam, and detecting a change in the reflected light amount. A calculating means for extracting a meandering frequency component due to the meandering portion of the groove or the land.

As a result, there is no need to provide a high-speed response to the detection system for detecting the tracking signal, so that an inexpensive detection system can be configured.

According to a sixth aspect of the present invention, there is provided a method for manufacturing an optical recording medium having a meandering portion in which only a part of one side wall of a groove or a land meanders.
A step of applying a photosensitive material to the substrate and, when forming the meandering portion, separating at least two light beams in a direction perpendicular to the longitudinal direction of the track, and separating one of the light beams into the orthogonal Exposing the photosensitive material by irradiating while oscillating in the direction.

As a result, since the shape of the meandering portion can be freely controlled, a meandering portion in which only one side wall of the groove or the land is meandering can be easily formed. Play.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a configuration example of an optical disc according to an embodiment of the present invention.

FIG. 2 is a configuration diagram showing a configuration example of an optical information recording / reproducing apparatus when the above optical disc is applied.

FIG. 3 is a plan view showing an arrangement example of an address recording unit in the optical disc.

FIG. 4 is a plan view of the address recording unit.

FIG. 5 is a plan view showing another configuration example of the address recording unit.

FIG. 6 is a plan view showing still another configuration example of the address recording unit.

FIG. 7 is an explanatory diagram when tracking the address recording unit in FIG. 6;

8 is a waveform diagram showing a tracking signal obtained by the tracking shown in FIG.

9 is a waveform chart showing the amount of reflected light of the optical disk obtained by the tracking shown in FIG.

FIG. 10 is a perspective view showing another arrangement example of the address recording unit.

FIG. 11 is a configuration diagram illustrating a configuration example of a recording device used in a photoresist exposure process.

FIG. 12 is an explanatory diagram illustrating a method of forming an address recording unit using the recording device.

FIG. 13 is a plan view showing a meandering method of grooves and lands in a conventional optical disc.

FIG. 14 is a plan view showing another meandering method of grooves or lands in a conventional optical disc.

FIG. 15 is a plan view showing a shared address system in a conventional optical disc.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Optical disk (optical recording medium) 21 Groove 22 Land 24 Address recording part (meandering part)

Claims (6)

[Claims] An optical recording medium for recording, reproducing or erasing information by irradiating a light beam onto a track formed of a land or a groove which is a groove between lands, wherein one of the groove or the land is provided. An optical recording medium characterized in that only a part of the side wall has a meandering portion. 2. The optical disk according to claim 1, wherein the optical recording medium is an optical disk, and meandering portions formed on each track of the optical disk are formed in a radial direction of the optical disk. recoding media. 3. The optical recording medium is an optical disc, wherein a meandering portion formed on a track of the optical disc is formed at a position different from a meandering portion formed on an adjacent track in a radial direction of the optical disc. The optical recording medium according to claim 1, wherein 4. An optical recording medium according to claim 1, wherein said optical recording medium is irradiated with a light beam, and said light detecting means detects reflected light. An optical information recording / reproducing apparatus comprising: a calculating means for detecting a tracking signal based on the signal and extracting a meandering frequency component of the groove or land included in the tracking signal. 5. An optical recording medium according to claim 1, further comprising: a light detecting means for detecting a reflected light amount obtained by irradiating the optical recording medium with a light beam; An optical information recording / reproducing apparatus, comprising: an arithmetic unit for extracting a meandering frequency component due to a meandering portion of a groove or a land by detecting. 6. An optical recording medium for recording, reproducing, or erasing information by irradiating a light beam to a track composed of a land or a groove which is a groove between lands. A method of manufacturing an optical recording medium having a meandering portion in which only a part of a side wall is meandering, comprising: applying a photosensitive material to a substrate; and forming at least two light beams on a track when forming the meandering portion. Exposing the photosensitive material by irradiating one of the light beams while vibrating in the orthogonal direction while separating the light beam in a direction perpendicular to the longitudinal direction of the light beam. Manufacturing method of recording medium.