JP2003346384A - Optical recording and reproducing medium, its original plate, method of manufacturing and device for optical recording and reproducing medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical recording and reproducing medium that can make tracking servo control without degrading its recording and reproducing characteristics even when it is required to set a plurality of track pitches. <P>SOLUTION: The optical recording and reproducing medium has two or more track pitches formed with hill and dale patterns on the surface of a disk base, and the recording and reproducing light is radiated to the patterns along their tracks. The track pitches of the patterns 11 and 12 having different pitches are made larger than 1.00 time or but 6.25 times or smaller the track pitch of the minimum track pitch pattern 13 out of the patterns 11 to 13. Further, the region between the patterns having different track pitches is used as a transition region for changing the track pitch and the tracks are formed into spirals. <P>COPYRIGHT: (C)2004,JPO

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spiral track having a plurality of concave and convex patterns such as pits and grooves set optically detectable, and other information patterns and grooves set optically recordable and reproducible. The present invention relates to an optical recording / reproducing medium, a master for producing an optical recording / reproducing medium, a method for producing an optical recording / reproducing medium, and an optical recording / reproducing apparatus.

[0002]

2. Description of the Related Art In an optical recording / reproducing apparatus, a signal recording layer on a substrate is irradiated with light, such as laser light, while being mounted on a predetermined rotary table and rotated in an optical recording / reproducing apparatus. It is set so that recording is performed and the reflected light is detected to perform reproduction. As an optical recording / reproducing medium, a read-only CD-ROM (Compact Disc)
-Read Only Memory), a magneto-optical disk capable of rewriting a signal, a phase change optical disk, and the like are known.

In a recording medium such as an MD (Mini Disc; registered trademark of Sony Corporation), for example, a groove for recording various information as recorded contents and information such as the type of the disc itself and the recording capacity are generally recorded. Pits are formed. The groove is engraved in a groove shape along the circumferential direction of the disk, and is, for example, wobble.
In the case of a groove, the planar pattern is formed so as to meander with a predetermined amplitude in the radial direction of the disk.
On the other hand, the pits are generally formed in a three-dimensional shape such that the planar pattern is circular or oval, and the width and length are narrowed in the depth direction. A large number of pits are arranged along the circumferential direction of the disk to form one track.

As an example, a groove is formed in a data recording area, and a PIC (Permanent Memory) is formed in a lead-in track area.
ent Information & Control data) area.
The pits are formed so as to carry TOC (Table Of Contents) information or information such as a pulse signal of a predetermined period as information of the disk itself as described above. Therefore, in an optical disk such as a conventional MD, an area in which pits are formed and an area in which grooves are formed are mixed, and these constitute one spiral track as the whole disk.

In general, the width of a groove is set to be wider than the width of a pit. This is achieved by increasing the width of a groove for recording data.
This is because the reproduction can be performed more accurately. That is, when data is recorded in a narrow groove, noise increases and the S / N ratio decreases. Alternatively, it is generally conceivable to record data on a land portion wider than the groove, but in a configuration using a wobble groove,
In actuality, the phases of adjacent grooves in the radial direction of the disc do not match, so that the width of the land always changes and the fluctuation of the reproduced signal becomes large, which is not suitable for practical use. Therefore, it is desirable to record data in a wide groove.

[0006] The conventional MD recording / reproducing time is set to 60 minutes or 74 minutes, but in recent years a longer time of 80 minutes has been proposed. In a general MD, a lead-in track area in which a pit carrying TOC information or the like is formed based on a unified standard or the like has a distance r from the center.
Is an area from r = 14.5 to 16.0 [mm], and a data recording area in which a groove for data to be recorded / reproduced is formed has a distance r from the center r = 16.0 to 30.5 [m].
m].

The recording / reproducing time is determined by the recording / reproducing speed (linear velocity) of the groove and the track pitch.
According to the MD standard, the linear velocity is 1.20 [m / s] or more.
When the track pitch is 40 [m / s] or less, the track pitch is 1.60 ± 0.
10 [μm].

The recording / reproducing time is changed from 60 minutes to 74 minutes with respect to the recording / reproducing time, the linear velocity at the time of reading data, and the track pitch in such an MD having one spiral continuous track. And the setting of the linear velocity at the time of reading is 1.40 [m /
s] to 1.20 [m / s], and when the recording / reproducing time goes from 74 minutes to 80 minutes, the linear velocity is 1.20 [m / s] because the linear velocity is already the lower limit of the standard. From 1.60 [μm] to 1.51 [μm]
m]. This lengthens (increases) the recording / reproducing time under the condition that the external dimensions of the disk and various characteristics of the optical pickup of the recording / reproducing apparatus are not changed.
For this purpose, it is necessary to lower the linear velocity of reading or to shorten the track pitch.

In a conventional optical disk such as an MD or a magneto-optical (MO) disk, a track of a pit and a track of a groove are arranged so as to form one spiral, and a track is formed between the pit and the groove. The pitch is set the same. Therefore, in a master disc manufacturing apparatus used when manufacturing a conventional optical disc, pits and pits are formed at a constant track pitch over substantially the entire surface of the disc from a lead-in track area where pits are formed to a data recording area where grooves are formed. The concave and convex pattern of the groove was carved. Therefore, it is not considered to change the track pitch midway, but rather various techniques have been devised to maintain a constant track pitch as accurately as possible.

In particular, in the case of an MD capable of recording and reproducing data for 80 minutes, the track pitch of the groove is set to 1.50 to 1.51 [μm], which is narrower than the conventional 1.60 [μm].
m]. If the track pitch of the groove is set to 1.50 [μm], the track pitch of the pits is unified to 1.50 [μm] in accordance with the conventional technology.

However, both the pit track pitch and the groove track pitch are 1.50 [μm].
When the width is narrowed as described above, optical detection of pits may be difficult or impossible. That is, conventionally, the MD standard generally uses a track pitch of 1.60 [μm] as a reference, and a push-pull signal or an RC (Radial) signal at that time.
The signal characteristics of servo signals and pits such as constants are determined and standardized. Therefore, a track pitch of 1.5
The present inventors have found that it is difficult to conform to the general recording and reproducing characteristics standard defined in the MD standard in terms of push-pull signals and crosstalk, especially for pits, especially for pits. It was confirmed by experiments and its analysis.

[0012]

On the other hand, the present applicant, in Japanese Patent Application No. 2000-248385, set the pit track pitch wider than the groove track pitch,
We have proposed a recording medium, a master recording medium, and a method of manufacturing a recording medium in which the ratio is set to be more than 1.00 to 1.13 or less. That is, in the prior art, the track pitch of the groove and the track pitch of the pit are set to be the same, so that optical detection of the pit may be difficult or impossible in some cases. In the medium, the recording medium master, and the method of manufacturing the recording medium, the track pitch of the pits is made wider than the track pitch of the grooves, and the ratio is more than 1.00 to 1.1.
By setting it to 3 or less, pits can be optically detected, and practical detection accuracy can be obtained.

The track pitch of the groove is 1.50.
[Μm] or more and less than 1.70 [μm], the allowable range of the track pitch is 1.60 ± 0.10.
Using a general recording and reproducing device set to [μm],
It is also possible to record and reproduce various information on the recording medium according to the present invention.

For example, in order to realize a recording medium capable of recording or reproducing data for a long time or a large capacity such as an MD set to be capable of recording and reproducing data for 80 minutes, the track pitch of the groove is reduced to about 1.51 μm. It is required to increase the data recording capacity by setting it to be narrow. In this case, if the pit track pitch is set to 1.13 times, which is the maximum value of the above ratio, the pit track pitch value is about 1.70 [μm], and both the groove and pit track pitches are generally 1.60 ± 0.10 which is the condition of the track pitch in a typical recording / reproducing apparatus
[Μm] within the allowable range. Therefore,
Similarly, the pit track pitch and the groove track pitch can be set to pitches at which recording and / or reproduction can be performed by a general recording / reproducing apparatus.

By the way, DVR, which is currently being studied as an optical recording / reproducing medium having a higher recording density, that is, a larger capacity, has been studied.
For a high-density optical disc such as (Digital Video Recordable), a format in which pits and grooves have different track pitches has been proposed.

For example, BCA (Burst Cutting
Area; an area in which license data is described in a barcode) has a track pitch of 2000 nm, a PIC track pitch is 350 nm and a rectangular wobble groove, and a data recording area has a track pitch of 320 nm and a sine wave wobble. A format for forming a groove or a triangular wave wobble groove has been proposed.

In the case of such a configuration, the inner peripheral BC
A problem is that continuous recording and reproduction can be performed in the BCA area, the PIC area, and the data recording area without deteriorating the recording and reproduction characteristics in the boundary area between the A area, the PIC area, and the data recording area. It is. However, at present, there is a defect that the tracking servo signal at the change point from the PIC area (track pitch of 350 nm) to the data recording area (track pitch of 320 nm) is disturbed, and the tracking servo becomes unstable. Furthermore, it has been impossible to change the track pitch abruptly from the BCA area (track pitch of 2000 nm) to the PIC area (track pitch of 350 nm), and stably apply the tracking servo.

The present invention solves such a problem and enables stable tracking servo without deteriorating the recording / reproducing characteristics even in an optical recording / reproducing medium in which a plurality of track pitches need to be set. An object of the present invention is to provide an optical recording / reproducing medium, a method for manufacturing an optical recording / reproducing medium, and an optical recording / reproducing apparatus.

[0019]

In an optical recording / reproducing medium according to the present invention, a plurality of concave / convex patterns are formed on a disk-shaped substrate surface at two or more track pitches. Alternatively, an optical recording / reproducing medium on which recording and / or reproduction is performed by irradiating light for reproduction, wherein a track pitch of a concave / convex pattern having a minimum track pitch among a plurality of concave / convex patterns is different from this. The ratio of the track pitch of the other concavo-convex pattern having the track pitch exceeds 1.00 and 6.25
Further, a region between the uneven patterns having different track pitches among a plurality of uneven patterns set as follows is defined as a transition region in which the track pitch gradually changes, and a track is defined as one.
It is configured to be formed in two spirals.

In the master for producing an optical recording / reproducing medium according to the present invention, a plurality of concavo-convex patterns are formed on a disc-shaped substrate surface.
For manufacturing an optical recording / reproducing medium for producing an optical recording / reproducing medium which is formed with the above track pitch and which is irradiated with recording and / or reproducing light along the track of the concavo-convex pattern to perform recording and / or reproducing. The ratio of the track pitch of the concave / convex pattern having a different track pitch to the track pitch of the concave / convex pattern having the smallest track pitch among the plurality of concave / convex patterns of the optical recording / reproducing medium, which is a master. Is set to more than 1.00 and equal to or less than 6.25, and furthermore, a region between the concavo-convex patterns having different track pitches among a plurality of concavo-convex patterns is
The track is formed as a single spiral as a transition area where the track pitch gradually changes.

Further, in the method of manufacturing an optical recording / reproducing medium according to the present invention, a plurality of concave / convex patterns are formed on the surface of a disk-shaped substrate at two or more track pitches, and recording and / or recording is performed along the tracks of the concave / convex patterns. What is claimed is: 1. A method for manufacturing an optical recording / reproducing medium in which recording and / or reproduction is performed by irradiating light for reproduction, wherein the optical recording / reproducing medium has an uneven pattern having a minimum track pitch among a plurality of uneven patterns. The ratio of the track pitch of the other concavo-convex pattern having a different track pitch to the track pitch is set to more than 1.00 and equal to or less than 6.25. A track is formed in one spiral as a transition area where the track pitch gradually changes.

Further, in the optical recording / reproducing apparatus according to the present invention, a plurality of concavo-convex patterns are formed on the surface of a disk-shaped substrate at two or more track pitches, and recording and / or reproducing along the tracks of the plurality of concavo-convex patterns. An optical recording / reproducing apparatus using an optical recording / reproducing medium on which recording and / or reproduction is performed by irradiating light, wherein a track of a concave / convex pattern having a minimum track pitch among a plurality of concave / convex patterns of the optical recording / reproducing medium is provided. The ratio of the track pitch of the other uneven pattern having a different track pitch to the pitch is set to be more than 1.00 and equal to or less than 6.25, and the track pitch of the plurality of uneven patterns of the optical recording / reproducing medium is set. The area between different uneven patterns of
As a transition area in which the track pitch changes gradually, the track is formed in one spiral, and a series of recording and reproduction are performed on the track of the optical recording and reproduction medium.

As described above, in the present invention, a plurality of concavo-convex patterns having two or more track pitches are provided. Particularly, the track pitch differs from the track pitch of the concavo-convex pattern having the minimum track pitch. The track pitch ratio of the other uneven patterns is set to be more than 1.00 and equal to or less than 6.25, and a transition area where the track pitch gradually changes is provided in an area between the uneven patterns having different track pitches. The track is formed by forming one spiral. With such a configuration, for example, a series of recording / reproducing, that is, continuous recording / reproducing of the concave / convex pattern corresponding to each area of the above-described BCA or PIC and the concave / convex pattern such as the groove of the data recording area can be performed. Thus, it is possible to provide an optical recording / reproducing medium capable of performing the following.

That is, when the track pitch of the groove and the track pitch of the BCA or PIC greatly differ from each other in the conventional configuration, it is necessary to prevent access to this area since the tracking servo is not applied in the area where the track pitch changes. In addition, when trying to keep the track pitch ratio small, recording on the BCA section becomes impossible, and optical detection of the rectangular wobble of the PIC may become difficult or impossible. According to the present invention, a series of recording and reproduction of each pattern can be performed, and the recording to the BCA portion and the optical detection of the rectangular wobble of the PIC can be reliably performed.

For example, in the BCA area (track pitch 200
0 nm) to PIC area (track pitch 350n)
m) Also, by gradually changing the track pitch from the PIC area (track pitch of 350 nm) to the data recording area (track pitch of 320 nm), disturbance of the tracking servo signal at the changed point can be eliminated, and stable tracking servo can be realized. . With such a configuration, an optical recording / reproducing medium having good recording / reproducing characteristics and an optical recording / reproducing apparatus using the same can be provided.

[0026]

Embodiments of the present invention will be described below in detail with reference to the drawings. In the following examples, the present invention is applied to an optical recording / reproducing medium having a DVR type configuration, a master disc, a manufacturing method, and an optical recording / reproducing apparatus. However, the present invention is not limited to this, and various other Can be modified and changed.

FIG. 1 is an explanatory diagram showing a schematic sectional structure of an optical recording / reproducing medium according to one embodiment of the present invention.
As shown in FIG. 1, the optical recording / reproducing medium according to the present invention comprises:
The substrate 1 has a plurality of concavo-convex patterns, in the illustrated example, first to third concavo-convex patterns 11 to 13. On the substrate 1, for example, a reflective layer 2, a dielectric layer 3, a recording layer 4, a dielectric layer 5, and a protective layer 6 are sequentially laminated. In this example, recording is performed from the protective layer 6 side. as well as/
Or light L for reproduction, in this case, for example, laser light for reproduction, etc.
Is irradiated onto each pattern via the optical pickup 14, and the recorded content is reproduced, for example.

In this example, as described above, DVR
As shown in FIG. 2, a first concavo-convex pattern 11 having a relatively wide track pitch is formed in a groove shape in, for example, the above-mentioned BCA region. On the other hand, the second pattern 12 having a smaller track pitch is formed as a rectangular pit pattern in the above-mentioned PIC area, for example, and the third pattern 13 having a smaller track pitch is formed as a wobble groove in the recording area in this case. It is formed as a wave.

In the BCA area, the distance from the center, that is, the radius r is between r = 21.3 [mm] and 22.2 [mm], the PIC
The region has a radius r of 22.24 [mm] to 23.2 [mm].
, The data recording area has a radius r = 23.2 [mm] to 5
Each is formed during 8.5 [mm].

In the present invention, the ratio of the track pitch of each of these patterns is selected to be more than 1.00 and not more than 6.25. In the example shown in FIG. 1, if the track pitches of the first to third uneven patterns 11 to 13 are Tp ₁ , Tp ₂ and Tp ₃ , respectively, Tp ₁ = 200
0 nm, Tp ₂ = 350 nm, Tp ₃ = 320 nm, and the ratio of the track pitch of the first and second uneven patterns to the track pitch of the third uneven pattern 13 having the smallest track pitch is 1.09, respectively. 6.25.

As described above, the ratio of the track pitch of each pattern is set to a value exceeding 1.00 and not more than 6.25. This optical recording / reproducing medium is a so-called DV
In the case of R, the groove track pitch of the data recording area is 320 nm. This is to reduce the pitch so as to obtain a large capacity capable of recording and reproducing for a longer time.

In the present invention, a transition region in which the track pitch gradually changes is provided at the boundary between the plurality of concave and convex patterns set at each track pitch. That is, in the first transition region 14 shown in FIG.
In the second transition area 15, the track pitch is gradually changed from 350 nm to 320 nm, so that the tracking servo can be stably performed and deterioration of the recording / reproducing characteristics can be avoided.

The process of forming each concavo-convex pattern by gradually changing the track pitch in this manner will be described in detail with reference to FIG. 3 showing an example of the configuration of an optical recording apparatus. Incidentally, the optical recording / reproducing medium or the master of the optical recording / reproducing medium according to the embodiment of the present invention can be manufactured by a method of exposing a pit or groove pattern by the optical recording apparatus, a method of manufacturing an optical recording / reproducing medium including the same, and the like. Since they are embodied, they will also be described below.

This optical recording apparatus is, as shown in FIG.
A light source 20, such as a laser, a mirror 21 and a mirror 22, a driving circuit 26, a voltage frequency controller 27, a position sensor 30,
It is composed of a laser scale 31, a slide servo 32, an air slider 33, a moving optical table 40, a turntable 34 on which a master substrate 51 is mounted, a spindle shaft 35, and a spindle servo 36. The chain line c indicates the rotation axis of the spindle shaft 35.

As the light source 20, a predetermined pattern exposure is performed on the photosensitive layer 52 on the master substrate 51, for example, at a wavelength λ = 2.
A 66 nm recording laser can be used, but the light source for exposure is not particularly limited to such a laser light source. The laser light B emitted from the laser light source 20 travels straight as a parallel beam, is reflected by the mirrors 21 and 22, changes its direction, and is guided to the moving optical table 40.

The moving optical table 40 has two wedge prisms 23 and 25 and one acousto-optic modulation deflector (AOM / AOD; Acoustic Optical Mod) sandwiched therebetween.
ulator / Acoustic Optical Deflector) 24. The acousto-optic modulation deflector 24 is arranged so that the laser light incident as a parallel beam satisfies the Bragg condition with the lattice plane of the acousto-optic element, and the horizontal direction of the beam B emitted from the wedge prism 25. The wedge prisms 23 and 25 are arranged so that the height does not change. As the acousto-optic element used for the acousto-optic modulation deflector 24, tellurium oxide (TeO ₂ ) is preferable.

A predetermined signal is supplied from the drive circuit 26 to the acousto-optic modulation deflector 24. This signal is a constant level DC signal when a groove is formed. The driving circuit 26 is supplied with a high-frequency signal from a voltage frequency controller (VCO) 27. A control signal is supplied to the voltage frequency controller 27. The control signal from the voltage frequency controller 27 is a zero-level direct current (DC) signal when forming a DC groove of BCA, and a bi-phase rectangular signal when forming a rectangular wobble groove of PIC.
When a Sin wobble groove is formed in the data recording area, the signal is a signal of 956.5 kHz. The 956.5 kHz signal records the wobble information of the address.

The acousto-optic modulation deflector 24 utilizes the fact that the intensity of the first-order diffracted light in Bragg diffraction is substantially proportional to the ultrasonic power, and modulates the ultrasonic power based on the recording signal to produce a laser beam. B light modulation is performed. As described above, in order to realize Bragg diffraction, the Bragg condition: 2 dsin θ = nλ (where, d: lattice spacing,
λ: wavelength of laser light, θ: angle between laser light and lattice plane,
n: an integer), the positional relationship and the posture of the acousto-optic modulation deflector 24 with respect to the optical axis of the laser beam are set.

In this optical recording apparatus, the first concave / convex pattern 11 composed of an array of grooves with a track pitch of 2000 nm in the BCA area and the first concave / convex pattern 11 in the PIC area
The second concave / convex pattern 12 composed of an array of rectangular wobble grooves having a track pitch of 0 nm and the third concave / convex pattern 13 which is a wobbling groove in which sine waves are wobbled in the data recording area are exposed as a single continuous spiral pattern. The feed pitch of the moving optical table 40 is set to 2000 nm in the BCA region while controlling the rotation speed of the turntable 34 so that the linear velocity in the longitudinal direction of the track is 5.28 m / s, as formed on the layer 52. , And PIC areas, and exposure is performed at 320 nm in the data recording area.

The moving optical table 40 detects its position by the position sensor 30 and performs exposure at a timing and a pitch corresponding to each of the areas, thereby obtaining the above-described uneven patterns of the BCA, PIC, and data recording areas. The latent image can be exposed on the photosensitive layer 52 on the master 51 at a predetermined pitch. In addition, the laser scale 31
The slide servo 32 and the air slider 33 are based on a wavelength (for example, 0.78 [μm]) detected by
Is controlled, the feed pitch of the moving optical table 40 can be instantaneously changed. However, in this example, as described above, the feed pitch is gradually changed in the boundary region of each region. A configuration is provided in which a region where the track pitch is gradually changed is provided.

That is, the BCA area (radius r = 21.3)
[Mm] to 22.2 [mm]), the feed pitch is 200
A pattern exposure corresponding to the first concave-convex pattern 11 is performed at 0 nm, and the first transition region 14 (radius r = 22.2 [mm] to 22.24 [m] where the track pitch changes is performed.
m]), the feed pitch is from 2000 nm to 350 nm.
Change gradually. PIC area (radius r = 22.24)
[Mm] to 23.2 [mm]), the feed pitch is 350
nm and the second transition region 15 (radius r = 23.2
[Mm]), the feed pitch is changed from 350 nm to 320 n.
m. Data recording area (radius r = 2
Between 3.2 [mm] and 58.5 [mm]), each is formed at a feed pitch of 320 nm.

The laser beam B modulated and deflected as described above passes through the magnifying lens 28 and is irradiated on the photosensitive layer 52 of the master 51 by the mirror 29 and the objective lens 37.
A desired BCA and PIC and a latent image of a data recording area groove are formed.

Subsequently, the master 51 is subjected to a development process, and the exposed portion of the photosensitive layer 52, that is, the resist is dissolved to perform development. That is, although not shown, in a state where the master 51 is placed on a turntable of a developing machine, the master 51 is rotated by the turntable to drop a developing solution on the surface of the master 51 to develop a resist on the surface, and a BCA area ( A first concave / convex pattern composed of a groove of 2000 nm track pitch), a second concave / convex pattern composed of a rectangular wobble groove of a PIC area (350 nm track pitch), and a third wobbling groove of a sine wave wobble in the data recording area. It is possible to obtain a master for manufacturing an optical recording / reproducing medium in which each of the concavo-convex patterns is formed as one spirally continuous pattern.

The magnifying lens 28 has a focal length of, for example, 50 [mm] and a numerical aperture NA of the objective lens 37 of, for example, 0.9, so that the track pitch of each of the concavo-convex patterns can be maintained well. It is possible.

In this manner, the DVR type recording / reproducing apparatus can perform recording / reproduction on the optical recording / reproducing medium having the DVR type configuration, and can accurately read a series of information in the BCA area, the PIC area, and the data recording area. A master for producing an optical recording / reproducing medium for an optical recording / reproducing medium can be obtained.

Next, a process of forming a stamper from which the optical recording / reproducing medium manufacturing master can be used to form a large number of optical recording / reproducing medium substrates will be described with reference to FIGS. 4A to 4D. FIG. 4A shows an enlarged cross-sectional configuration of a main part of an optical recording / reproducing medium manufacturing master 60 created by the above-described optical recording device and developing device. Although FIG. 4A shows only the first and second uneven patterns 53A and 53B, it goes without saying that the third uneven pattern is also formed in the extension area.

On the master 60 for producing an optical recording / reproducing medium, a conductive film layer made of a nickel film is formed by an electroless plating method or the like, and the master 60 on which the conductive film layer is formed is transferred to an electroforming apparatus. Attachment, as shown in FIG. 4B, a plating layer 54a made of nickel or the like so as to have a thickness of about 300 ± 5 [μm] on the conductive film layer by an electrical plating method.
To form Subsequently, as shown in FIG. 4C, the nickel plating layer 54a is separated from the master 60 with a cutter or the like, and the photosensitive layer 52 such as a photoresist on the signal forming surface of the nickel plating layer 54a, that is, the uneven pattern forming surface is washed with acetone or the like. Then, a stamper 54 is manufactured. On the stamper 54, first and second concave / convex patterns 55A and 55B in which concavities and convexities are reversed from the patterns of the first and second concave / convex patterns 53A and 53B formed on the photosensitive layer 52 by the exposure of the optical recording apparatus described above. It is formed.

Further, from this stamper 54, a mother stamper 56 with inverted concavities and convexities is manufactured. That is, after a predetermined release layer or the like is applied to the pattern surface of the stamper 54, a plating layer is applied by an electroplating method or the like, and the plating layer is further removed by a cutter or the like, as shown in FIG. 4D. The above-mentioned first and second uneven patterns 55A
Mother stamper 56 on which first and second concave / convex patterns 57A and 57B in which the concavities and convexities are reversed with respect to the pattern of 55B and 55B can be manufactured.

Next, an optical recording / reproducing medium for evaluation was produced as follows. First, a substrate for an optical recording / reproducing medium is manufactured from a mother stamper 56 by injection molding using a transparent resin of polycarbonate (refractive index: 1.59), and first to third pits and grooves formed on the surface thereof are formed. Are transferred. Molded substrate thickness is 1.1
mm.

On the signal forming surface, as described with reference to FIG. 1, the reflective layer 2 made of an Ag alloy or the like, ZnS
A recording layer 4 made of the dielectric layer 3, a phase change material such as GeSbTe alloy consisting -SiO _2, etc., ZnS-SiO ₂
And the like and a dielectric layer 5 are sequentially formed by sputtering. Thereafter, an ultraviolet curable resin or the like is applied on the dielectric layer 5 by a spin coating method, and the ultraviolet curable resin is irradiated with ultraviolet light and cured to form a protective layer 6 having a thickness of, for example, 0.1 mm. . Through the above steps, an optical recording / reproducing medium having a phase change recording layer having a DVR type configuration is manufactured.

Example A DVR disk having different track pitches of BCA, PIC and data recording area was manufactured by the above-described method of manufacturing an optical recording / reproducing medium having a DVR type configuration. The work of evaluating the concavo-convex pattern of the optical recording / reproducing medium is evaluated using a DVR evaluator equipped with an optical pickup having a wavelength of 406 nm and a numerical aperture of NA = 0.85.

In this example, tracking was performed by a differential push-pull (DPP) method using three laser beams radiated at predetermined intervals. FIG. 5 shows a main configuration of an optical system of a device for evaluating a DVR type optical recording / reproducing medium.

In FIG. 5, reference numeral 61 denotes a wavelength λ = 406 nm.
And a laser beam emitted from the light source is collimated by a collimator lens 62.
The grating 63 divides the beam into three beams of 0-order light (main beam) and ± 1st-order light (sub beam). These three beams (P-polarized light) pass through a polarization beam splitter (PBS) 64 and a quarter-wave plate 65 as circularly polarized light, and are transmitted by an optical pickup 66 including an objective lens having a numerical aperture NA = 0.85. The light is focused on a predetermined recording track of the optical recording / reproducing medium 10. The spot at the center of the main beam is used for recording and reproduction of recorded information, and the light spot of the sub beam is used for detecting a tracking error.

In FIG. 5, reference numeral 68 denotes the optical recording / reproducing medium 1.
Rotating means for rotating 0 as indicated by an arrow d is shown. An alternate long and short dash line e indicates a rotation axis of the optical recording / reproducing medium 10.

The reflected light from the optical recording / reproducing medium 10 passes through the optical pickup 66 and the quarter-wave plate 65 again, so that the circularly polarized light becomes S-polarized light and the polarization beam splitter 64.
And is incident on the combination lens 71.

The laser light incident on the combination lens 71 is incident on the photodiode 72 via a lens that gives astigmatism to the laser beam, and is converted into an electric signal corresponding to the intensity of the beam, and a servo signal, that is, a focus error It is output to the servo circuit as a signal and a tracking error signal. The photodiode 72 has divided detectors 73 (A to H). The return light of the main beam is a four-divided detector A located at the center of the detector 73.
To D, and the return light of the sub-beam enters E to H located on both sides of the detector 73.

As described above, in this example, the tracking servo signal was obtained by the differential push-pull method. That is, signals A to H output from A to H of the detector 73 are subjected to addition and subtraction processing in a predetermined circuit system (not shown) as follows, and the following signals are output. That is, the reproduced signal (MO signal) of the optical recording / reproducing medium = (A + B +
C + D) Pit reproduction signal (for example, EFM signal) = (A + B + C +
D) Push-pull signal = (B + C)-(A + D) Differential push-pull (tracking servo) signal = (B +
C)-(A + D) -k (EF) + (GH) (k is a predetermined constant).

As a result of evaluating the recording / reproducing characteristics by the above-described evaluator, in the BCA area having a track pitch of 2000 nm, the track pitch is sufficiently wide and stable tracking can be realized. The authentication code information and the like of the media such as can be reproduced. In the PIC region having a track pitch of 350 nm, the linear velocity, recording power, reproduction power, and recording pulse (waveform) of a rectangular wobble groove having an amplitude of ± 100 nm, and the so-called reflection layer 2 to dielectric layer 5 described with reference to FIG. Various kinds of information necessary for recording / reproducing of the medium, such as whether the recording unit has a one-layer configuration or a two-layer configuration, could be reproduced stably. Also, the wobble signal of the above-mentioned various information could be reproduced stably using the push-pull signal. In the data recording area with a track pitch of 320 nm, stable tracking servo and wobble groove address information could be reproduced stably. This also uses a push-pull signal to stably control the amplitude of ADIP (Address in pregroove) ± 12.
nm wobble signal could be reproduced.

Further, recording and reproduction are performed with a 1-7 modulation RF signal (A + B + C + D) in a wobble groove portion (recording region close to the reading surface) of the data recording region, so that jitter of -10% or less can be reproduced on the entire surface of the disk. Recording and reproduction characteristics.

Further, a track pitch transition area from the BCA area to the PIC area (radius r = 22.2 [mm] to 2
2.24 [mm]).
Since it was gradually changed from 000 nm to 350 nm, stable tracking could be realized. Track pitch transition area from PIC area to data recording area (radius r = 23.
2 [mm]), the track pitch was gradually changed from 350 nm to 320 nm, so that stable tracking could be realized. According to the above-described method, the track pitch is changed from 2000 nm to 350 nm, and from 350 nm to 32 nm.
A series of trackings could be stably realized in the entire region of 0 nm.

The change amount of the track pitch is 2000 nm
Even with a sufficiently wide variation amount of / 320 nm = 6.25 times, a series of trackings could be stably realized in all regions. 5. The ratio of the track pitch of each concavo-convex pattern in the BCA area, PIC area, and data recording area exceeds 1.00.
The setting is such that it is within the range of 25, and the change in the track pitch between the regions may be changed gradually.

In order to achieve high recording density, it is desirable that the transition region be as narrow as possible. For example, it is said that a tracking servo can normally follow up to several kHz. Therefore, when the linear velocity is determined, the upper limit of the transition region where the track pitch changes is approximately determined from the linear velocity and the servo band frequency. However,
It has been found that depending on the amount of change in the track pitch, it is necessary to make the length of the transition region longer than a certain level. This will be described below.

For example, when the linear velocity of the optical recording / reproducing medium is 5 m
/ S, the tracking band of the tracking servo is 5 kHz
Assuming that z, the length in the track direction obtained from this is considered to be sufficient if 5/5000 = 0.001 [m] = 1 [mm] or more.

However, in the above-described embodiment, the BC
In the track pitch transition area 1 from the A area to the PIC area, since the track pitch change amount is large,
It was found that good tracking servo characteristics were obtained when the length of the transition region in the track direction was about 100 mm or more.

Further, in the track pitch transition area 2 from the PIC area to the data recording area in the above-described embodiment, since the change amount of the track pitch is small, the length of the transition area in the track direction is about 10 mm or more. It was found that good tracking servo characteristics were obtained.

In the above embodiment, the width in the radial direction of the transition area where the track pitch changes from the BCA area to the PIC area is set to 0.04 mm. In order to increase the recording density, it is desirable to make each recording area closer to each other. Therefore, it is desirable to make the transition area as short as possible. Therefore, in the present invention, the average distance of the transition region from the center of the optical recording / reproducing medium is r _m ,
Selecting the track pitch of an average of the concavo-convex pattern adjacent to the transition region when the Tp _m, the track direction of the length x of the transition region, 10 mm and _{≦ x ≦ 2πr m × 0.04 /} Tp m Is what you do.

As described above, the PI from the BCA area
In the transition region where the track pitch changes to the C region, the track pitch changes from 2000 nm to 350 nm,
That is, in this case, the change amount is five times or more, and the length of the transition region having such a change amount in the track direction is 100n.
It was found that stable tracking can be realized when the distance is equal to or more than m. Therefore, when the amount of change is not more than twice as in the area where the transition from the PIC area to the data recording area occurs, the length of the transition area in the track direction is set to 10 m.
m or more and the change amount is about 5 times, 100 mm
It is desirable to make the above.

Thus, it can be seen that by setting the length of the transition region in the track direction to be 10 mm or more and 100 mm or less, a high recording density can be achieved and good recording / reproducing characteristics can be maintained.

In the above example, the case where the present invention is applied to a large-capacity optical disk such as a DVR has been described. However, the optical recording / reproducing medium according to the present invention, its master or the manufacturing method is limited to a DVR or the like. Needless to say, it will not be done. In addition, for example, DVD-RW4.7
It is also applicable to various optical disks or the like in which pits and grooves are connected in a spiral like GB. Also, the present invention can be applied to various optical disks and the like having different track pitches for pits, grooves (DC, rectangular wobbles, sine wave wobbles) and other uneven patterns, and having different track pitches between regions.

[0070]

As described above, according to the optical recording / reproducing medium, the master optical recording / reproducing medium, and the method of manufacturing the optical recording / reproducing medium of the present invention, pits, grooves (DC, rectangular wobbles) are formed in one disk. , Sinusoidal wobble) and other uneven patterns can be set to different optimal track pitches, and sufficient recording and reproducing characteristics can be obtained in each format.

Further, since the change in track pitch between the areas (formats) is connected to one spiral which gradually changes, in an optical recording / reproducing apparatus using this optical recording / reproducing medium, a series of Tracking can be stably realized.

Further, by appropriately selecting the length in the track direction of the transition region where the track pitch changes,
An optical recording / reproducing medium which sufficiently satisfies recording / reproducing characteristics and has a high recording density, and an optical recording / reproducing apparatus using the same can be provided.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a schematic cross-sectional configuration of an example of an optical recording / reproducing medium.

FIG. 2 is an explanatory diagram showing a schematic plan configuration of an example of an optical recording / reproducing medium.

FIG. 3 is an explanatory diagram illustrating a configuration of an example of an optical recording device.

FIG. 4 is a process chart showing an example of a method for manufacturing an optical recording / reproducing medium.

FIG. 5 is an explanatory diagram showing a configuration of a main part of an example of an optical recording / reproducing apparatus.

[Explanation of symbols]

1 substrate, 2 reflective layer, 3 dielectric layer, 4 recording layer, 5
Dielectric layer, 6 protective layer, 11 first uneven pattern,
12 second concavo-convex pattern, 13 third concavo-convex pattern, 14 first transition region, 15 second transition region, 1
6 optical pickup, 20 light sources, 21 mirrors, 22
Mirror, 23 wedge prism, 24 acousto-optic modulation deflector, 25 wedge prism, 26 drive circuit, 2
7 voltage frequency controller, 28 magnifying lens, 29 mirror, 30 position sensor, 31 laser scale, 32
Slide servo, 33 air slider, 34 turntable, 35 spindle shaft, 36 spindle servo, 40 moving table, 51 master substrate, 52 photosensitive layer, 53A first uneven pattern, 53B second uneven pattern, 54a plating layer, 54 stamper, 55A
A first uneven pattern, 55B a second uneven pattern,
56 mother stamper, 57A first uneven pattern,
57B Second concave / convex pattern, 60 master for producing optical recording / reproducing medium, 61 light source, 62 collimating lens, 6
3 gratings, 64 polarizing beam splitters, 6
5 1/4 wavelength plate, 66 optical pickup, 68 rotating means, 71 combination lens, 72 photodiode, 73 detector

   ────────────────────────────────────────────────── ─── Continuation of front page    (72) Inventor Shin Masuhara             6-7-35 Kita Shinagawa, Shinagawa-ku, Tokyo Soni             ー Inc. F term (reference) 5D029 KB03 KB12 WA05 WB01 WB02                       WB11 WC01                 5D090 AA01 CC04 KK06                 5D121 AA02 BA01 BB08

Claims (16)

[Claims] 1. A plurality of concave / convex patterns are formed on a disc-shaped substrate surface at two or more track pitches, and recording and / or reproducing light is irradiated along tracks of the plural concave / convex patterns to perform recording and / or reproducing. And / or an optical recording / reproducing medium on which reproduction is performed, wherein the track pitch of the concave / convex pattern in which the track pitch is minimized among the plurality of concave / convex patterns is the same as that of another concave / convex pattern having a different track pitch. The ratio between the track pitches is set to more than 1.00 and equal to or less than 6.25, and a region between the concave and convex patterns having different track pitches is a transition region in which the track pitch gradually changes. An optical recording / reproducing medium, wherein the track is formed in one spiral. 2. The optical recording / reproducing medium according to claim 1, wherein the track pitch of the plurality of concavo-convex patterns is set to be 320 nm or more and 2000 nm or less. 3. The wavelength of the light for reproduction is 405 ± 10n.
mm, and the numerical aperture NA of the objective lens of the optical system for recording and / or reproduction of the optical recording / reproducing medium is 0.85 ±
2. The optical recording / reproducing medium according to claim 1, wherein the value is 0.01. 4. The optical recording / reproducing medium according to claim 1, wherein the track pitch changes continuously in the transition area. 5. A length x of the transition region along the track direction, wherein an average distance of the transition region from the center of the optical recording / reproducing medium is r _m , and the length of the plurality of concavo-convex patterns adjacent to the transition region is the track pitch averaged when the Tp _m, optical recording medium according to claim 1, characterized in that are 10 mm in _{≦ x ≦ 2πr m × 0.04 /} Tp m. 6. The optical recording / reproducing medium according to claim 1, wherein at least one of the plurality of concave / convex patterns is a wobble groove. 7. A plurality of concavo-convex patterns are formed on a disk-shaped substrate surface at two or more track pitches, and recording and / or reproducing light is irradiated along tracks of the plurality of concavo-convex patterns to perform recording and / or reproducing. And / or an optical recording / reproducing medium production master for producing an optical recording / reproducing medium to be reproduced, wherein the optical recording / reproducing medium has a concave / convex pattern having a minimum track pitch among the plurality of concave / convex patterns. The ratio of the track pitch of another uneven pattern having a different track pitch to the track pitch is 1.
The area between the concavo-convex patterns having different track pitches among the plurality of concavo-convex patterns is set as a transition area in which the track pitch gradually changes, and the track is composed of one spiral. A master for producing an optical recording / reproducing medium, characterized by being formed in a shape. 8. The optical recording / reproducing medium, wherein the track pitch continuously changes in a region between the concave / convex patterns having different track pitches among the plurality of concave / convex patterns. Item 8. A master for producing an optical recording / reproducing medium according to item 7. 9. The transition area of the optical recording / reproducing medium,
The length x along the track direction is equal to the length of the transition region.
The average distance from the center of the optical recording / reproducing medium is r_m, Above
The average trajectory of the plurality of concavo-convex patterns adjacent to the transfer area
The pitch is Tp _mAnd when 10 [mm] ≦ x ≦ 2πr_m× 0.04 / Tp_m 8. The optical recording and reproducing apparatus according to claim 7, wherein
Master for production of live media. 10. A plurality of concavo-convex patterns are formed on a disk-shaped substrate surface at two or more track pitches, and recording and / or reproducing light is irradiated along the tracks of the plurality of concavo-convex patterns to perform recording and / or reproducing. And / or a method of manufacturing an optical recording / reproducing medium on which reproduction is performed, wherein the track pitch of the concave / convex pattern in which the track pitch is minimized among the plurality of concave / convex patterns is different from the track pitch of the concave / convex pattern. The ratio of the track pitch of the uneven pattern is set to be more than 1.00 and equal to or less than 6.25, and the area between the uneven patterns having different track pitches among the plurality of uneven patterns is changed so that the track pitch is gradually changed. A method for manufacturing an optical recording / reproducing medium, wherein the track is formed in one spiral as a region. 11. The optical recording / reproducing medium, wherein the track pitch is continuously changed in a region between the uneven patterns having different track pitches among the plurality of uneven patterns. 11. The method for producing an optical recording / reproducing medium according to item 10. The method according to claim 12 wherein the optical recording medium of length x along the track direction of the transition region, adjacent the average distance from the center of the optical recording medium of the transition region r _m, above the transition region the track pitch of the average of the plurality of uneven patterns when the Tp _m, the optical recording and reproducing according to claim 10, characterized in that the 10 [mm] _{≦ x ≦ 2πr m × 0.04 /} Tp m The method of manufacturing the medium. 13. A plurality of concavo-convex patterns are formed on a disk-shaped substrate surface at two or more track pitches, and recording and / or reproducing light is irradiated along tracks of the plurality of concavo-convex patterns to record and / or reproduce. An optical recording / reproducing apparatus using an optical recording / reproducing medium in which reproduction is performed, wherein the track pitch of the plurality of concave / convex patterns of the optical recording / reproducing medium is minimized with respect to the track pitch of the concave / convex pattern. Has a track pitch ratio of 1.00 of another uneven pattern having a different track pitch.
Is set to 6.25 or less, and an area between the uneven patterns having different track pitches among the plurality of uneven patterns of the optical recording / reproducing medium is a transition area in which the track pitch gradually changes. An optical recording / reproducing apparatus, wherein a track is formed in one spiral, and a series of recording / reproducing is performed on the track on the optical recording / reproducing medium. 14. The optical recording / reproducing medium, wherein the track pitch continuously changes in a region between the concave and convex patterns having different track pitches among the plurality of concave and convex patterns. Item 14. An optical recording / reproducing device according to item 13. 15. The optical recording / reproducing medium, wherein the transition area
The length x of the region along the track direction is
The average distance from the center of the optical recording / reproducing medium is r _m,Up
The average of the plurality of concavo-convex patterns adjacent to the transition region
Track pitch is Tp_mAnd when 10 [mm] ≦ x ≦ 2πr_m× 0.04 / Tp_m 14. The optical recording according to claim 13, wherein
Playback device. 16. The optical recording / reproducing medium according to claim 13, wherein at least a part of said plurality of concave / convex patterns is a wobble groove, and wobble information of said wobble groove is reproduced. An optical recording / reproducing apparatus according to claim 1.