JP3545893B2 - Optical information recording medium and master disc exposure method - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an optical information recording medium such as an optical disk and an optical card, and more particularly to an optical information recording medium in which preformat information is superimposed on prepits and pregrooves, and a method of exposing the master.
[0002]
[Prior art]
In recent years, recordable CDs (CD-R and CD-E) have been put into practical use in addition to optical information recording media such as read-only compact discs (CDs). After the additional recording, it is compatible with a read-only CD (can be reproduced by a CD player). The feature of CD-R and CD-E is that, as disclosed in JP-A-6-76363, a reference signal whose guide groove (pregroove) has a predetermined frequency and preformat information (address information) are combined. That is, the signal is wobbled in a meandering manner as shown in FIG. In the recording drive, the preformat information is demodulated by a reproducing means as disclosed in JP-A-7-169052, and recording and reproduction are performed based on the preformat information. Here, FIG. 14 shows a configuration example of a conventional read-only CD, and FIG. 15 shows a configuration example of a conventional recordable CD-R or CD-E. In the case of a CD-R or CD-E, FIG. At a location (Lin in FIG. 15) corresponding to the TOC (Table of contents) in the case of the CD shown, control information related to recording / reproduction called special information is recorded. When a CD-R or CD-E is additionally recorded, the recording drive simultaneously records the TOC information, thereby enabling reproduction by a CD player. In the case of CD-R and CD-E, there are areas called PCA (Power calibration area) and PMA (Program memory area). PCA is an area for performing test recording with a recording drive, and PMA is an area for recording the memory usage status of an optical information recording medium.
[0003]
The preformat information is combined with a reference signal having a lower frequency than the recording data information. For this reason, if a high-pass filter (HPF) higher than the frequency of the reference signal is provided before the EFM demodulator as in the signal detection circuit shown in FIG. Reproduction can be performed without being affected by a signal. In the reproduction of preformat information detected from a push-pull signal, if a band-pass filter (BPF) corresponding to the frequency of the reference signal is provided at a stage prior to the FM demodulator, the data signal is conversely reproduced. Can be played without being affected. Generally, the frequency of a reference signal that wobbles in a meandering manner is several tens of kilohertz, and the minimum bit of a recording data signal is several megahertz.
[0004]
[Problems to be solved by the invention]
The recording / reproducing method of CD-R and CD-E described in the prior art has the following disadvantages.
{Circle around (1)} An optical disc has a read-only ROM and a recordable RAM. A CD-R or CD-E, which is a RAM, is an optical disc that can reproduce a signal with a ROM player (reproduction-only drive) after recording. As described in the related art, a recording / reproduction drive for CD-R or CD-E performs recording / reproduction based on preformat information superimposed on a pregroove. For this reason, if an unrecorded RAM disk is erroneously loaded into the ROM player, there is a problem in that the ROM disk which only reproduces the information of the pre-pit string as a signal cannot reproduce the RAM disk and cannot even recognize it.
[0005]
(2) At present, an optical disk having a larger capacity than a CD is being studied, but in order to increase the capacity, it is necessary to reduce the track pitch and the bit size. A player for a large-capacity optical disk has a shorter wavelength and a higher NA (wavelength 635 to 685 nm, NA = 0) than an optical pickup having a wavelength of 780 nm and NA = 0.5 used in a CD system to reduce the beam spot diameter. .6) is adopted. Even if a large-capacity optical disk having a narrow track pitch and a small bit size is loaded onto a CD-based ROM player or RAM player (recording / reproduction drive), signal reproduction cannot be performed due to a large beam spot diameter. There's a problem.
[0006]
The present invention has been made in view of the above circumstances, and in order to solve the problems of the conventional method,ThatThe purpose is as follows.
BookAn object of the present invention is to provide an optical information recording medium capable of accurately reproducing preformat information in order to solve the above problem (1).
Also bookAn object of the present invention is to provide an optical information recording medium capable of accurately reproducing preformat information in order to solve the above problem (2).
More booksSUMMARY OF THE INVENTION It is an object of the present invention to provide an optical information recording medium capable of accurately reproducing preformat information in order to solve the above-mentioned problem (2), and to facilitate means for exposing a stamper master of the optical information recording medium. That is.
More booksThe purpose of the invention isOf the present inventionIt is an object of the present invention to provide a master exposure method which facilitates a stamper master exposure means for an optical information recording medium.
[0007]
[Means for Solving the Problems]
To achieve the above objectives,The present invention is characterized by the following configuration.
(1).In an optical information recording medium in which address information of the optical information recording medium and control information for recording / reproducing are preformatted on a substrate in advance, the control information is recorded as a prepit row pattern, and the prepit row is The wobble is formed in a meandering manner based on a signal obtained by combining the address information and the control information with a reference signal having a predetermined frequency.
[0008]
(2). (1)In the optical information recording medium described in the above, when both the pre-groove (guide groove) for recording data and the pre-pit row are combined, the pre-groove has a reference signal having a predetermined frequency in the same manner as the pre-pit row. The address information is wobbled in a meandering manner based on the synthesized signal, and the address information superimposed as the wobble is continuous between the pre-pit row and the pre-groove, and is recorded as a pre-pit row pattern. And the address information superimposed on the pre-pit row as wobble is equal(Claim 1).
(3). (2)In the optical information recording medium described, the wobble amplitude of the pre-pit string is larger than the wobble amplitude of the pre-groove.(Claim 2).
[0009]
(4). (1)In the optical information recording medium described above, the track pitch of the prepit row in which the preformat information is recorded is wider than the track pitch of the pregroove.
(5). (4)In the optical information recording medium described above, when switching from the pre-groove to the pre-pit row, the track pitch of this switching portion gradually increases and becomes the same as the track pitch of the pre-pit row, and when switching from the pre-pit row to the pre-groove. However, the track pitch of the switching portion is gradually reduced to be the same as the track pitch of the pregroove.(Claim 3).
(6). (4) or (5)In the optical information recording medium described in the above, the address information of the area where the track pitch is switched is not incremented and is fixed.(Claim 4 or 10).
[0010]
(7). (1)In the optical information recording medium described above, the recording linear density of the prepit row in the control information area is lower than the recording linear density of the information recorded in the pregroove.
(8). (7)In the optical information recording medium described, when switching from a pre-groove to a pre-pit row, the recording linear density of the pre-pit row at the switching portion gradually decreases to a predetermined recording linear density, and the pre-pit row is switched to a pre-groove. In the case of switching, the recording linear density of the switching portion gradually increases and becomes the same as the recording linear density of the information recorded in the pre-groove.(Claim 5).
(9). (7) or (8)In the optical information recording medium described above, in the case where the prepit string is wobbled in a meandering manner based on a reference signal having a predetermined frequency, the frequency of the wobble reference signal changes in accordance with a change in the recording linear density of the prepit string. Made(Claim 6 or 11).
(10). (7) or (8)In the optical information recording medium described above, the address information of the area where the recording linear density of the pre-pit row switches is not incremented and is fixed.(Claim 7 or 12).
[0011]
(11). (1)In the optical information recording medium described above, the track pitch of the pre-pit row on which preformat information is recorded is wider than the track pitch of the pre-groove, and the recording linear density of the pre-pit row is higher than the information recorded on the pre-groove. The configuration has a low density.
(12). (11)In the optical information recording medium described above, when switching from a pre-groove to a pre-pit row, the track pitch of the pre-pit row at the switching portion gradually increases, and the recording linear density gradually decreases to a predetermined recording linear density. When switching from the pre-pit row to the pre-groove, the track pitch at this switching portion gradually decreases, and the recording linear density gradually increases to be the same as the recording linear density of the information recorded in the pre-groove. Configuration(Claim 8).
(13). (11) or (12)In the optical information recording medium described above, the address information of the area where the track pitch of the pre-pit row and the recording linear density are switched does not increment and is fixed.(Claim 9 or 13).
[0012]
(14). (8) or (12)A master exposure method at the time of manufacturing the optical information recording medium according to the above, wherein the pre-pit row of the optical information recording medium is wobbled in a meandering form based on a reference signal having a predetermined frequency, the recording linear density of the pre-pit row As means for changing the frequency of the reference signal in accordance with the change, the frequency of the reference signal is fixed during master exposure, and the exposure linear velocity is changed.(Claim 14).
[0013]
(15). (8) or (12)A master exposure method at the time of manufacturing the optical information recording medium according to the above, wherein the pre-pit row of the optical information recording medium is wobbled in a meandering form based on a reference signal having a predetermined frequency, the recording linear density of the pre-pit row As means for changing the frequency of the reference signal in accordance with the change, the frequency of the reference signal is changed in accordance with the recording linear density of the pre-pit row at the time of master exposure, so that the exposure linear velocity is fixed.(Claim 15).
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. First, a configuration example and a manufacturing method of an optical information recording medium according to the present invention will be described.
[0015]
(Structure (1))
FIG. 1 is a diagram illustrating the format of a disc-shaped optical information recording medium (optical disc) according to the present invention, and the configuration of a prepit array and a pregroove (and recording pits recorded in the pregroove). In FIG. 1, a spiral recording track is provided on the optical information recording medium 1 along the circumference, and PCA, PMA, Lin, a program area (Program Area), and Lout are sequentially arranged from the inner circumference to the outer circumference. Each area is divided. In the Lin area of the optical information recording medium 1, address information and control information necessary for recording / reproducing (recommended recording power, recordable address range, recording strategy condition, medium type, etc.) are recorded as a pre-pit string. The pre-pit row is wobbled in a meandering manner based on a signal obtained by combining the address information and the control information with a reference signal having a predetermined frequency, similarly to the pre-groove (see FIGS. 5 to 7). The program area is formed of a pre-groove and is an area where data can be recorded. The pre-pit row and the pre-groove on the optical information recording medium 1 are spirally arranged, and the address information superimposed on the pre-groove is continuous. Also, the preformat information superimposed by meandering the prepit string and the preformat information recorded in the pattern of the prepit string include information equivalent to each other, and of course, the address information also has the same address value. With such a structure of the pre-pit row and the pre-groove of the optical information recording medium, even when the pre-format information is reproduced from the pattern of the pre-pit row, the pre-format information superimposed by meandering the pre-groove and the pre-pit row is used. In both cases, the preformat information of the optical information recording medium 1 can be reproduced.
[0016]
(Structure (2))
In the optical information recording medium 1 shown in FIG. 1, preformat information superimposed on a pregroove and preformat information recorded as a prepit string have different modulation structures. In the case of a pregroove, code data of preformat information is recorded by applying FM modulation to a predetermined frequency, and in the case of a prepit sequence, code data of preformat information is recorded by applying EFM modulation. Here, the reference frequency of FM modulation is several tens of kilohertz, and the reference frequency of EFM modulation is several megahertz. For this reason, the length of the minimum unit of a data group called a frame is different between the pre-groove and the pre-pit string, so that each address is allocated as shown in FIG. In FIG. 2, one frame of the preformat information in which the pregroove and the prepit string are superposed in a meandering manner corresponds to m frames of the preformat information recorded in the pattern of the prepit string. The address of the preformat information recorded in the pattern of the prepit string is expressed by a combination of the address of the preformat information superimposed by meandering the pregroove and the prepit string and the address of the preformat information recorded in the pattern of the prepit string. Is done.
[0017]
(Structure (3))
As in the signal detection circuit shown in FIG. 17, in the preformat signal superimposed on the pregroove, reflected light from the optical information recording medium 1 is received by a two-division photodiode (PD) and photoelectrically converted. To reproduce a signal. A signal used for reproducing the preformat signal is a push-pull signal which is a difference signal of the photodiode (PD), and a band-pass filter (BPF) provided in a preceding stage of the FM demodulator forms a pre-pit row. The signal component (high frequency component) is removed. FIG. 3 shows a state of a signal of preformat information reproduced from a pregroove and a prepit string wobbled in a meandering manner (hereinafter, this signal is referred to as a wobble signal). In the case where there is no pre-pit, that is, in the case of a pre-groove, a wobble signal (Iw1) indicated by a dashed line in FIG. 3 is obtained. The amount of light decreases, and the waveform shown by the thin line in FIG. 3 is obtained. Therefore, when the high-frequency component of the pre-pit string is removed by a band-pass filter (BPF), a wobble signal (Iw2) indicated by a thick line in FIG. 3 is obtained, and the magnitude of the wobble signal is reduced as compared with the case of using only the pre-groove. For this reason, in the case of the pre-pit row, it is more difficult to reproduce the superimposed pre-format signal by meandering than in the pre-groove. To solve this problem, the wobble amplitude (amplitude of the meandering groove) of the pre-pit row may be made larger than that of the pre-groove. FIG. 4 shows the relationship between the wobble amplitude (WB) and the magnitude (Iw) of the wobble signal. From this relationship, the wobble amplitude WB2 of the pre-pit row is
WB2 = WB1 × (Iw1 / Iw2)
(However, WB1 is the pre-groove wobble amplitude)
, The wobble signal of the pre-pit string can be made the same as the size of the pre-groove.
[0018]
(Configuration ▲ 4 ▼)
In the optical information recording medium, a technique of reducing the track pitch and decreasing the bit length (increasing the linear density) is used to increase the storage capacity. Further, as described in the problem of the conventional method, as the capacity of the optical information recording medium increases, the beam spot size for recording and reproducing also decreases. In order to stably perform recording and reproduction on the optical information recording medium, a beam spot diameter smaller than at least the track pitch is required. A player whose beam spot size is not large (small diameter) cannot record or reproduce an optical information recording medium having a large capacity. The information recording medium cannot be recognized. Therefore, if a large-capacity optical information recording medium is provided with an area that can be reproduced even by a player having a partially large beam spot size, and preformat information including control information of the optical information recording medium is recorded in this area, the large-capacity optical information recording medium can be obtained. Even a non-capacitated player can recognize a large-capacity optical information recording medium. According to the present invention, the track pitch of the area including the control signal is widened, and it is possible to reproduce even a player having a large beam spot size. FIG. 5 shows a configuration example of the physical format of the optical information recording medium of the present invention. As shown in FIG. 5, the track pitch (TP2) of the meandering pre-pit row region is wider than the track pitch (TP1) of the pre-groove. Further, as described in the configuration (3), the wobble amplitude (WB2) of the pre-pit row is larger than the wobble amplitude (WB1) of the pre-groove area.
[0019]
(Configuration ▲ 5)
In the configuration (4), the density of the pre-pit train area in the track direction is reduced (the track pitch is widened) so that even a player having a large beam spot size can easily reproduce the preformat information of the optical information recording medium. The same effect can be obtained by lowering the recording linear density of the area (in the disc-shaped optical information recording medium shown in FIG. 1, the density in the circumferential direction). FIG. 6 shows a configuration example of a physical format of an optical information recording medium having a configuration in which the recording linear density of the pre-pit row region is reduced. The bit size (BL2) of the minimum pit in the pre-pit row is longer than the bit size (BL1) of the minimum pit recorded in the pregroove, and the interval between the pits is wide. Therefore, it is easy to reproduce even a large beam spot. Further, as described in the configuration (3), the wobble amplitude (WB2) of the pre-pit row is larger than the wobble amplitude (WB1) of the pre-groove area. With this effect, even a player having a large beam spot size can easily reproduce the preformat information of the optical information recording medium.
[0020]
(Structure (6))
The optical information recording medium has both a configuration in which the track pitch of the pre-pit row region is widened as shown in FIG. 5 and a configuration in which the recording linear density of the pre-pit row region is lowered as shown in FIG. 6 (configuration {circle around (4)}). And the configuration (5)), it is obvious that the preformat information can be more easily reproduced, and a high effect can be obtained. FIG. 7 shows a configuration example of a physical format of an optical information recording medium having a configuration in which the track pitch in the pre-pit row region is widened and the recording linear density in the pre-pit row region is reduced.
[0021]
(Configuration ▲ 7)
Next, FIG. 8 is a flowchart showing a manufacturing process of a substrate molding die (hereinafter, referred to as a stamper) when an optical information recording medium is actually manufactured. Hereinafter, the manufacturing process of the stamper will be described with reference to FIG.
1. First, a photoresist 2b is spin-coated on a disk-shaped glass substrate 2a (hereinafter, a coating of the glass substrate 2a with the photoresist 2b is referred to as a resist master 2). The thickness of the photoresist 2b is equal to the groove depth of the pre-pit or pre-groove formed on the glass substrate 2a.
2. Next, this resist master 2 is cut by a master exposure machine using an Ar gas laser. FIG. 9 schematically shows the configuration of a master exposure machine. As shown in FIG. 9, cutting by the master exposure machine 5 places the resist master 2 on a turntable 6 mounted on a carriage 7 of a transverse feed mechanism, rotates the resist master 2 by the turntable 6, and The Ar gas laser is condensed by the objective lens 10 and is exposed while the laser beam is being transmitted. By performing exposure in this manner, the grooves can be formed in a spiral shape. The master exposure machine 5 also includes a pulse modulator 8 for cutting the laser to form a pre-pit row, and a wobble deflector 9 for wobbling the pre-pit row and the pre-groove in a meandering manner. On the axis. A latent image of a groove is formed on the resist master 2 by such a master exposure machine 5.
3. After the latent image is formed on the resist master 2, development is performed to form a groove pattern on the resist master 2.
4. Next, a Ni film 3 is sputtered on the resist master 2 as a conductive film.
5. After the sputtering of the Ni film 3, a Ni electroforming process is performed.
6. The stamper 4 having a groove pattern on the surface is completed by peeling, washing, polishing the back surface, and processing the inner and outer diameters of the electroformed product 3 '.
[0022]
When manufacturing the stamper of the present invention (the above-described (4), (5), and (6) configurations), the problem is the portion where the track pitch is switched. Generally, it is difficult to instantaneously change the rotation speed of the turntable 6 of the master exposure machine 5 and the lateral feed speed of the carriage 7 that determines the size of the track pitch. This is because the influence of inertia due to the weight of the turntable 6 for chucking the resist master 2 is large. Therefore, it is desirable to gradually change the numerical value in an area where the track pitch and the recording linear density are switched. FIG. 10 shows the configuration of the present invention. In FIG. 10, when switching from the pre-groove to the pre-pit row (when switching from the PMA area to the Lin area), the track pitch (TP) gradually increases and the recording linear density also gradually decreases (the bit size (BL) increases). are doing. Also, when switching from the pre-pit row to the pre-groove (when switching from the Lin area to the program area), the track pitch (TP) is gradually narrowed, and the recording linear density is also gradually increased (the bit size (BL) is increased). Short).
Further, since the recording linear density of the switching area is gradually changed, even if the recording / reproducing player (RAM player) seeks to the area of the optical information recording medium where the track pitch is switched, the pre-recording is performed. The worst case in which no format information can be reproduced hardly occurs.
[0023]
(Configuration ▲ 8)
Next, FIG. 11 shows a configuration example of a control system of the master exposure machine. The control system of the master exposure machine 5 includes a reference pulse generator 12, a TT drive pulse generation circuit 13 for controlling the number of revolutions of the turntable 6, and a lateral feed motor drive pulse generation circuit 14 for the carriage 7 for controlling the size of the track pitch. , A pattern signal generating circuit 15 for controlling a pulse modulator 8 to generate a pattern of a pre-pit string, and a wobble signal for controlling a wobble deflector 9 to generate a wobble amount and a signal pattern of a pre-pit string and a pre-groove. A generation circuit 16, a focus servo circuit 17 for controlling a focus actuator of the objective lens 10, an exposure position detection circuit 18 for controlling a laser scale unit 19 to detect an exposure position on the resist master 2, and controls these circuits. It comprises a central processing unit (CPU) 11. Further, the four circuits of the TT drive pulse generation circuit 13, the lateral feed motor drive pulse generation circuit 14, the pattern signal generation circuit 15, and the wobble signal generation circuit 16 operate with a common reference signal from the reference pulse generator 12. As a result, the rotation, horizontal feed, pattern of the pre-pit row, and the pattern of the wobble during the exposure of the master are synchronized.
[0024]
In order to realize the configuration of FIG. 10 described in the above configuration (7), there are two master exposure methods. One is that a pattern signal for generating a pattern of a pre-pit row and a wobble signal for meandering the pre-pit row and the pre-groove are operated at a constant frequency, and a transverse feed speed of the carriage 7 for changing a track pitch is used. This is a method of changing the rotation speed (exposure linear velocity) of the turntable 6. In this case, in order to keep the groove shape constant in the plane of the optical information recording medium, it is necessary to change the light amount of the laser to be exposed according to the change of the exposure linear velocity. FIG. 12 shows the configuration of each control signal at the time of master exposure in this method. In the case of FIG. 12, since the constant linear velocity method is employed at the time of recording / reproducing on the optical information recording medium, the rotation speed of the turntable 6 is made uniform toward the outer periphery in accordance with the radial position of the optical information recording medium. Down to.
[0025]
The other is a method of changing a pattern signal for generating a pattern of a pre-pit row, a wobble signal for meandering the pre-pit row and the pre-groove, and a lateral feed speed for changing a track pitch. In this case, since the exposure linear velocity does not change, the light amount of the laser to be exposed may be constant. FIG. 13 shows a configuration of each control signal at the time of master exposure in this method. In FIG. 13, the pattern signal for generating the pattern of the pre-pit row, the wobble signal for meandering the pre-pit row and the pre-groove, and the lateral feed speed for changing the track pitch are changed in the Lin region. Since a constant linear velocity method is employed during recording and reproduction of the optical information recording medium, the rotation speed of the turntable 6 is uniformly reduced toward the outer periphery in accordance with the radial position of the optical information recording medium.
[0026]
As shown in FIG. 13, in order to change the wobble signal, it is necessary to generate a reference frequency of the wobble signal based on the shared reference signal, and to perform modulation arithmetic processing by changing this frequency. . Similarly, it is necessary to generate a reference frequency of a pattern signal based on a shared reference signal for a pattern signal for creating a pattern of a prepit row, and to perform modulation arithmetic processing by changing this frequency. However, there is a possibility that the time required for these arithmetic processes cannot keep up with the speed of master exposure. Therefore, it is better to hold (fix) the address of the switching area without incrementing it and output it, and use it for the preparation time for calculating the preformat information of the Lin area, so that the preformat information of the Lin area is generated more accurately. be able to. The same is true when switching from Lin to the program area. By holding the address of the switching area, there is an advantage that the recording and reproducing player can know from the address information that the switching area is being reproduced.
[0027]
【Example】
(Example (1))
As an embodiment of the optical information recording medium according to the present invention, an embodiment of the optical information recording medium when the capacity of the CD-R is increased will be described. The track pitch TP1 of each area of the PCA, PMA and program area of the optical information recording medium is 0.8 μm, the wobble amplitude WB1 is about 20 nm, the track pitch TP2 of the Lin area is 1.6 μm, and the wobble amplitude WB2 is about 40 nm. Further, by configuring the recording linear density of the program area to be twice the recording linear density of the pre-pit row in the Lin area, the recording capacity is increased to four times (2.6 gigabytes) with respect to the CD-R recording capacity of 650 megabytes. can do. In the portion where the track pitch and the recording linear density are switched before and after the Lin area, the track pitch and the linear density gradually change. In the Lin area, preformat information is recorded by two means of "pattern of prepit row" and "wobble the prepit row". The preformat information includes a recognition code indicating that the optical information recording medium is of a type in which the capacity of a CD-R is increased. Therefore, even a recording / reproducing player dedicated to a CD-R or a player dedicated to a ROM can reproduce the recognition code, and can recognize that the CD-R is an optical information recording medium having a large capacity. As a result, it is possible to process an optical information recording medium having a large CD-R without erroneously recording and reproducing. Incidentally, the configuration of the physical format of the optical information recording medium of this embodiment is the same as that of FIG.
[0028]
(Example (2))
A description will be given of a manufacturing example of the optical information recording medium stamper according to the embodiment (1). In the configuration of the control system of the master exposure machine 5 shown in FIG. 11, a TT drive pulse generation circuit 13 for controlling the number of rotations of the turntable 6 at the time of resist master exposure, and a transverse feed motor drive pulse for controlling the size of the track pitch The control method of the generation circuit 14, the pattern signal generation circuit 15 for generating the pattern of the prepit string, and the wobble signal generation circuit 16 for generating the wobble amount of the prepit string and the pregroove and the signal pattern is shown in FIG. Was used. In this embodiment, in order to increase the track pitch in the Lin area, the traverse speed in the Lin area is twice as high as in the other areas. Further, in order to lower the recording linear density of the pit row in the Lin area, the exposure linear velocity (the number of rotations of the turntable 6) in the Lin area was set to be twice that in the other areas.
[0029]
【The invention's effect】
As explained above,In (1) of "Means for solving the problem" described aboveIn the described optical information recording medium, the preformat information is formed on the substrate in advance by two methods, that is, the prepit string pattern and the pregroove are wobbled in a meandering shape and are superimposed, so that the prepit string pattern is reproduced as a signal. The preformat information can be reproduced by both a read-only ROM player and a recording / reproducing RAM player for recording / reproducing based on the wobble information superimposed on the pregroove.
[0030]
(2) (in claim 1)In the optical information recording medium described,(1)In addition to the structure and effect of the above, since the address indicated by the pre-pit string and the address superimposed on the pre-groove are continuous, recording is performed based on the pre-format information superimposed on the pre-groove by the recording / reproducing RAM player. Address information and continuity can be maintained. Therefore, the recorded optical information recording medium can be reproduced by a read-only ROM player.
[0031]
(4)In the optical information recording medium described,(1)In addition to the structure and effect of the above, the track pitch of the pre-pit row including the pre-format information is wider than the track pitch of the pre-groove, so that the recording density of the pre-pit row area is low, and the Format information can be easily reproduced.
[0032]
(7)In the optical information recording medium described,(1)In addition to the structure and effect of the above, the recording linear density of the pre-pit row including the pre-format information is lower than the recording linear density of the pre-groove, so that the recording density of the pre-pit row area is low, and the On the other hand, the preformat information can be easily reproduced.
[0033]
(11)In the optical information recording medium described,(1)In addition to the structure and effect of the above, the recording linear density of the pre-pit row including the preformat information is lower than the recording linear density of the pre-groove, and the track pitch of the pre-pit row is wider than the track pitch of the pre-groove. The recording density of the region is low, and the preformat information can be easily reproduced with respect to the beam spot diameter for recording and reproduction.
[0034]
(3) (in claim 2)In the optical information recording medium described,(2)In addition to the structure and effect of the above, since the wobble amplitude of the pre-pit row is made larger than the wobble amplitude of the pre-groove, the pre-format information can be obtained even in the region formed by the pre-pit row without lowering the C / N of the wobble signal. Can be reproduced accurately.
[0035]
(5) (Claim 3)In the optical information recording medium described,(4)In addition to the configuration and effect described above, since the track pitch is gradually changed in the region before and after the pre-pit row where the track pitch changes, the means for controlling the lateral feed during exposure of the master can be facilitated.
[0036]
(6) (Claim 4 or 10)In the optical information recording medium described,(4) or (5)In addition to the structure and effect of the above, since the address is fixed in the area before and after the prepit row where the track pitch changes, the preformat signal processing means relating to the address generation at the time of exposing the master can be simplified. .
[0037]
(8) (Claim 5)In the optical information recording medium described,(7)In addition to the structure and effect of the above, since the recording linear density is gradually changed in the area before and after the pre-pit row where the track pitch changes, the encoding processing means relating to data generation at the time of master exposure can be simplified. Can be.
[0038]
(9) (in claim 6 or 11)In the optical information recording medium described,(7) or (8)In addition to the configuration and effect of the above, since the frequency of the preformat information superimposed by meandering the prepit row and the frequency of the preformat information recorded in the prepit row pattern are synchronized, the signal of the prepit row pattern is reproduced. The preformat information can be reproduced by both a read-only ROM player that performs the read operation and a recording / reproduction RAM player that performs the recording and reproduction based on the wobble information superimposed on the pregroove.
[0039]
(10) (Claim 7 or 12)In the optical information recording medium described,(7) or (8)In addition to the configuration and effect of the above, since the address is fixed in the area before and after the pre-pit row where the recording linear density changes, the pre-format signal processing means relating to the address generation at the time of exposing the master can be simplified. it can.
[0040]
(12) (Claim 8)In the optical information recording medium described,(11)In addition to the structure and effect of the above, since the recording linear density and the track pitch are gradually changed in the area before and after the pre-pit row where the recording linear density and the track pitch change, the means for controlling the lateral feed at the time of exposing the master is required. It is possible to simplify the encoding processing means related to data generation at the time of master exposure.
[0041]
(13) (in claim 9 or 13)In the optical information recording medium described,(11) or (12)In addition to the configuration and effect of the above, since the addresses are fixed in the area before and after the pre-pit row where the recording linear density and the track pitch change, the pre-format signal processing means relating to the address generation at the time of exposing the master can be easily implemented. can do.
[0042]
(14) (Claim 14)In the master disc exposure method of the optical information recording medium described,(8) or (12) (Claim 5 or 8)As a means for exposing the master disc of the optical information recording medium, the frequency at which the wobble signal and the pattern signal are generated is fixed, and the recording linear density of the pre-pit row can be changed by changing the exposure linear velocity. Control of line density is easy.
[0043]
(15) (Claim 15)In the master disc exposure method of the optical information recording medium described,(8) or (12) (Claim 5 or 8)As a method for exposing the master disc of the optical information recording medium, the recording linear density of the pre-pit train can be changed by changing the frequency at which the wobble signal and the pattern signal are generated and fixing the exposure linear velocity. Control of line density is easy.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating the format of a disc-shaped optical information recording medium according to the present invention and the configuration of a prepit row and a pregroove.
FIG. 2 is an explanatory diagram of an address of a wobble signal and an address of a pre-pit string recorded on an optical information recording medium.
FIG. 3 is a diagram showing a state of a signal of preformat information reproduced from a pregroove and a prepit string wobbled in a meandering manner.
FIG. 4 is a diagram showing a relationship between a wobble amplitude (WB) of a pre-groove and a pre-pit row wobbled in a meandering shape and a magnitude (Iw) of a wobble signal.
FIG. 5 is a diagram showing a configuration example of a physical format of an optical information recording medium according to the present invention.
FIG. 6 is a diagram showing another configuration example of the physical format of the optical information recording medium according to the present invention.
FIG. 7 is a diagram showing still another configuration example of the physical format of the optical information recording medium according to the present invention.
FIG. 8 is a flowchart showing a manufacturing process of a substrate molding die (stamper) when an optical information recording medium is actually manufactured.
FIG. 9 is a diagram showing a configuration example of a master exposure machine used when manufacturing a stamper for an optical information recording medium according to the present invention.
FIG. 10 is a diagram showing changes in track pitch (TP) and bit size (BL) in each area of the optical information recording medium according to the present invention.
FIG. 11 is a diagram showing a configuration example of a control system of a master disc exposure machine used when manufacturing a stamper for an optical information recording medium according to the present invention.
FIG. 12 is an explanatory diagram of a method of exposing a master of an optical information recording medium according to the present invention, and is a diagram illustrating a configuration of each control signal at the time of exposing the master.
FIG. 13 is an explanatory diagram of a method of exposing the master of the optical information recording medium according to the present invention, and is a diagram illustrating another configuration of each control signal at the time of exposing the master.
FIG. 14 is a diagram illustrating the format of a conventional read-only optical information recording medium and the configuration of a pre-pit string.
FIG. 15 is a diagram illustrating the format of a conventional recordable optical information recording medium and the configuration of a pre-groove.
FIG. 16 is a diagram showing an example of a conventional pregroove wobbled in a meandering shape.
FIG. 17 is a diagram illustrating an example of a signal detection circuit that reproduces preformat information recorded on an optical information recording medium.
[Explanation of symbols]
1 Optical information recording medium
2 Resist master
2a Glass substrate
2b photoresist
3 Ni film
4 Stamper
5 Master exposure machine
6 Turntable
7 Carriage
8 pulse modulator
9 Wobble deflector
10 Objective lens
11 Central processing unit (CPU)
12 Reference pulse generator
13 TT drive pulse generation circuit
14. Horizontal drive motor drive pulse generation circuit
15 Pattern signal generation circuit
16 Wobble signal generation circuit
17 Focus servo circuit
18 Exposure position detection circuit
19 Laser scale unit
BL1 Bit size of minimum pit recorded in pregroove
BL2 Bit size of the minimum pit in the pre-pit row
Iw1 Pregroove wobble signal
Iw2 Wobble signal of pre-pit row
TP1 Pregroove track pitch
TP2 Track pitch of pre-pit row
WB1 Pre-groove wobble amplitude
WB2 Wobble amplitude of pre-pit row

Claims (15)

An optical information recording medium control information is formed in advance a substrate as pre-format information for recording and reproduction address information of the optical information recording medium, before Symbol control information is recorded as a pre-pit string pattern, besides the An optical information recording medium having a configuration in which a prepit string is wobbled in a meandering manner based on a signal obtained by combining the address information and the control information with a reference signal having a predetermined frequency ,
When both a pre-groove (guide groove) for recording data and the pre-pit row are combined, the pre-groove has a signal obtained by synthesizing the address information with a reference signal having a predetermined frequency similarly to the pre-pit row. Based on the wobble, the address information superimposed as the wobble is continuous between the pre-pit row and the pre-groove, and is superimposed on the pre-pit row as the wobble with the address information recorded as the pre-pit row pattern. An optical information recording medium characterized by having the same address information . 2. The optical information recording medium according to claim 1, wherein the wobble amplitude of the prepit train is larger than the wobble amplitude of the pregroove . An optical information recording medium in which address information of the optical information recording medium and control information for recording / reproducing are preformatted on a substrate in advance, wherein the control information is recorded as a prepit string pattern, and the prepit The row is wobbled in a meandering manner based on a signal obtained by combining the address information and the control information with a reference signal having a predetermined frequency, and the track pitch of the prepit row in which preformat information is recorded is determined by the pregroove. In an optical information recording medium configured to be wider than the track pitch of
When switching from the pre-groove to the pre-pit row, the track pitch of this switching portion gradually increases and becomes the same as the track pitch of the pre-pit row, and when switching from the pre-pit row to the pre-groove, the track pitch of this switching section Is gradually reduced to become equal to the track pitch of the pre-groove . An optical information recording medium in which address information of the optical information recording medium and control information for recording / reproducing are preformatted on a substrate in advance, wherein the control information is recorded as a prepit string pattern, and the prepit The row is wobbled in a meandering manner based on a signal obtained by combining the address information and the control information with a reference signal having a predetermined frequency, and the track pitch of the prepit row in which preformat information is recorded is determined by the pregroove. In an optical information recording medium configured to be wider than the track pitch of
An optical information recording medium , wherein address information of an area where a track pitch is switched is not incremented and is fixed . An optical information recording medium in which address information of the optical information recording medium and control information for recording / reproducing are preformatted on a substrate in advance, wherein the control information is recorded as a prepit string pattern, and the prepit The column is wobbled in a meandering manner based on a signal obtained by combining the address information and the control information with a reference signal having a predetermined frequency, and the recording linear density of the prepit row in the control information area is recorded in the pregroove. In an optical information recording medium configured to have a lower recording linear density than the information to be recorded,
When switching from the pre-groove to the pre-pit row, the recording linear density of the pre-pit row at this switching portion gradually decreases to a predetermined recording linear density, and when switching from the pre-pit row to the pre-groove, the An optical information recording medium, wherein the recording linear density gradually increases and becomes the same as the recording linear density of information recorded in a pre-groove . An optical information recording medium in which address information of the optical information recording medium and control information for recording / reproducing are preformatted on a substrate in advance, wherein the control information is recorded as a prepit string pattern, and the prepit The column is wobbled in a meandering manner based on a signal obtained by combining the address information and the control information with a reference signal having a predetermined frequency , and the recording linear density of the prepit row in the control information area is recorded in the pregroove. In an optical information recording medium configured to have a lower recording linear density than the information to be recorded,
An optical information recording medium, wherein the frequency of the wobble reference signal changes in accordance with a change in the recording linear density of the prepit string when the prepit string is wobbled in a meandering manner based on a reference signal having a predetermined frequency. . An optical information recording medium in which address information of the optical information recording medium and control information for recording / reproducing are preformatted on a substrate in advance, wherein the control information is recorded as a prepit string pattern, and the prepit The column is wobbled in a meandering manner based on a signal obtained by combining the address information and the control information with a reference signal having a predetermined frequency, and the recording linear density of the prepit row in the control information area is recorded in the pregroove. In an optical information recording medium configured to have a lower recording linear density than the information to be recorded,
An optical information recording medium, characterized in that address information of a region where a recording linear density of a pre-pit row switches is fixed without being incremented . An optical information recording medium in which address information of the optical information recording medium and control information for recording / reproducing are preformatted on a substrate in advance, wherein the control information is recorded as a prepit string pattern, and the prepit The row is wobbled in a meandering manner based on a signal obtained by combining the address information and the control information with a reference signal having a predetermined frequency, and the track pitch of the prepit row in which preformat information is recorded is determined by the pregroove. In the optical information recording medium having a configuration in which the recording linear density is wider than the track pitch and the recording linear density of the prepit row is lower than the information recorded in the pregroove,
When switching from the pre-groove to the pre-pit row, the track pitch of the pre-pit row at this switching portion gradually increases, and the recording linear density gradually decreases to a predetermined recording linear density. In this case, the track pitch of the switching portion gradually decreases, and the recording linear density gradually increases to become the same as the recording linear density of the information recorded in the pre-groove. Information recording medium. An optical information recording medium in which address information of the optical information recording medium and control information for recording / reproducing are preformatted on a substrate in advance, wherein the control information is recorded as a prepit string pattern, and the prepit The row is wobbled in a meandering manner based on a signal obtained by combining the address information and the control information with a reference signal having a predetermined frequency, and the track pitch of the prepit row in which preformat information is recorded is determined by the pregroove. In the optical information recording medium having a configuration in which the recording linear density is wider than the track pitch and the recording linear density of the prepit row is lower than the information recorded in the pregroove,
An optical information recording medium characterized in that address information of an area where a track pitch and a recording linear density of a pre-pit row are switched does not increment and is fixed . 4. The optical information recording medium according to claim 3, wherein the address information of the area where the track pitch changes is fixed without being incremented . In the optical information recording medium according to claim 5 , when the pre-pit row is wobbled in a meandering manner based on a reference signal having a predetermined frequency, the frequency of the wobble reference signal is changed in accordance with a change in the recording linear density of the pre-pit row. An optical information recording medium characterized by changing . 6. The optical information recording medium according to claim 5, wherein the address information of the area where the recording linear density of the pre-pit row switches does not increment and is fixed . 9. The optical information recording medium according to claim 8, wherein the address information of an area where the track pitch of the pre-pit row and the recording linear density are switched does not increment but is fixed. 9. The method of exposing a master according to claim 5, wherein the pre-pit row of the optical information recording medium is wobbled in a meandering manner based on a reference signal having a predetermined frequency. Means for changing the frequency of this reference signal in accordance with the change in the recording linear density of the optical information recording medium, wherein the frequency of the reference signal is fixed during exposure of the master and the exposure linear velocity is changed. Method. 9. The method of exposing a master according to claim 5, wherein the pre-pit row of the optical information recording medium is wobbled in a meandering manner based on a reference signal having a predetermined frequency. As a means for changing the frequency of this reference signal in accordance with the change in the recording linear density, the frequency of the reference signal is changed in accordance with the recording linear density of the pre-pit row during master exposure, and the exposure linear velocity is fixed. Master exposure method for optical information recording medium.

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