JP2003099946A - Master optical disk preparing apparatus, method for preparing master optical disk, master optical disk, optical disk substrate, and optical disk - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve such problems in the optical disk having a groove adjacent to a prepit that the deformation of the groove toward the outer periphery side as well as the movement of the pit center in the direction toward the outer periphery breaks the positional relationship with the groove center, on the outer periphery side, and that the deformation and the movement toward the inner periphery side are generated on the inner periphery side to the contrary, thereby giving rise to an erroneous tracking operation or a decrease in the C/N. SOLUTION: Near the zone boundary, pits are formed in the position shifted by Δ Cdp in advance in a direction reverse to the direction in which the pits are moved, a master disk is cut by deforming the groove in advance by ΔCsg in the counter direction of the groove deformation direction, and a stamper is formed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention mainly relates to an apparatus for manufacturing a rewritable optical disk master, a method for manufacturing an optical disk master, and an optical disk master based on a zone division format.

[0002]

2. Description of the Related Art The format of an optical disk is a high density by maintaining a constant bit density from the inner circumference to the outer circumference of the disk and a constant rotation angle method (CAV) which is excellent in arriving at a predetermined data sector quickly. There is a constant linear velocity method (CLV) that excels in performance. However, recent rewritable optical discs are
The zone division method that combines the features of V and CLV is becoming mainstream.

For example, DVD-REWRITER (commonly called DVD-R, which is defined in JIS-X-6243.
AM) disk. The first feature of the DVD-RAM format is that the zone is divided into a plurality of zones in the radial direction, and the zone rotation rate is kept constant within the zone to slow down the rotation rate every time when the zone shifts to the outer zone. The second characteristic is a single spiral land / groove format in which land tracks and groove tracks alternate each time the disk rotates, and the third characteristic is pre-pit information indicating the physical address of the recording sector on the outer peripheral side of the track. And assign to the inner circumference side
A PA (Complementary Allocated Pit Address) format, and a fourth feature is a groove wobble format in which a groove is slightly shifted at a monotone frequency.

A general master disk cutting method for a DVD-RAM disk having the above characteristics and a method for improving the same are described in JP-A-11-39655.

[0005]

The CAPA format, which is one of the features of the DVD-RAM disc, is a pit row that is shifted (wobbled) equidistantly from the track center to the upper (outer circumference) and lower (inner circumference). It can be used as an effective means to specify the physical track center.
Wobbled Tracking) is disclosed, for example, in JP-A-62-18.
No. 3037, etc. However, CAV
The above-mentioned method of defining the track center, which was effective in the format, has revealed a new problem of the optical disk alone, which is thought to be due to the increase in track density and zone division.

FIG. 8 shows a DVD-RAM (however, 4.7G
(B type) is a diagram schematically showing a single optical disc 400, and FIG. 11A is a diagram of the single optical disc 400 viewed from the recording surface.

The part that looks like a streak is in the CAPA format, and is a pre-pitted physical sector address part [PID; physical identification.
Data, hereinafter referred to as PID], and the PID portion of the first (# 0) sector starting from the disc index 401 is arranged in a straight line radially from the center of the disc 400. The parts are arranged at different angular positions for each zone.

FIG. 1B is a side view of the disk unit 400. Generally, the film surface side of a single optical disc in which a recording film (hereinafter simply referred to as a recording film) including a plurality of layers such as a recording phase change film, a reflection film, and a protective layer is sputtered on the surface of a replica substrate made of polycarbonate. Due to the difference in temperature and expansion coefficient between 400-S and the base 400-B of a single optical disk made of a polycarbonate material, the temperature may rise in a vapor deposition (sputtering) step or the like, and the warp shown in FIG. It was confirmed that the warp was corrected in the subsequent process, but the PID portion deformed the adjacent groove in the correction process and did not return to the original radial position.

FIG. 9 is a diagram for explaining the phenomenon in which the PID portion deforms the adjacent groove and does not return to the original radial position. FIG. 3B shows the CAPA structure PID in the center of the zone.
It is a figure which shows a pit and a groove.

PID that is shifted (wobbled) to the outer peripheral side
Radial center PID-L center of the pit and radial center P of the PID pit that is displaced (wobbled) toward the inner circumference side
The ID-G center is arranged at an equal distance from the groove center or the land center that indicates the radial center of the groove 403.

The distance between the groove center and the land center is defined as a track pitch TP, and the PID-
The shift amount between the L center and the PID-G center is plus or minus one half of TP.

FIG. 1A is a view showing a boundary portion with the outer peripheral side adjacent zone. The groove in the outer peripheral side adjacent zone is PI
It is deformed by ΔSg (adjacent groove distortion amount) so that it is pushed into the D pit, and at the same time, the PID center is also Δdp.
((PID center displacement amount) moves from the PID theoretical center.

FIG. 3C is a diagram showing a boundary portion with the inner peripheral side adjacent zone. The adjacent groove strain ΔSg and the PID center displacement Δdp are deformed and displaced in a direction opposite to that in FIG.

As described above, even if an optical disk master in which the PID pits having the CAPA structure are theoretically arranged at correct positions is produced, distortion is generated mainly due to heat generation in the vapor deposition process, and as a result, the distortion occurs in the outer peripheral direction. Wobbled PI
There is a problem that the track center indicated by the difference in the amount of reflected light at the time of reproduction between the D pit and the PID pit that is displaced (wobbled) in the inner circumferential direction is deviated from the actual track center.
Further, there is a problem that the groove is deformed by being pushed out to the PID pit portion of the adjacent zone, which not only becomes a disturbance element of the push-pull tracking signal, but also deteriorates the quality of the groove wobble reproduction signal.

It is an object of the present invention to provide a highly reliable optical disk unit that has very little adjacent groove distortion and PID center displacement at a low cost.

[0016]

To achieve the above object, the present invention provides a disc-shaped cutting master having a laser light source and a surface coated with a photosensitizer responsive to the wavelength of a laser beam emitted from the laser light source. A rotating mechanism for rotating at a predetermined speed, an objective lens that converges the laser beam emitted from the laser light source into a spot on the photosensitive surface of the cutting master, and the converged laser spot in the radial direction of the cutting master. A feed mechanism for moving at a predetermined speed, a modulation signal generating means for generating a track guiding pregroove signal and a PID prepit signal in a predetermined format, and an optical modulation means for making an output signal of the modulation signal generating means a control input. And timing information and direction to shift the laser spot in the radial direction of the cutting master. A deflection signal generating means having means for correcting the predicted displacement means and PID pit position to produce a distribution and magnitude information in a predetermined format,
In an optical disk master forming apparatus having an optical deflecting means which uses an output signal of the deflection signal generating means as a control input, a means for recognizing a plurality of rotational angle direction ranges in which PIDs in an inner peripheral side adjacent zone are prepitted and an outer peripheral side PID of adjacent zone
Is added to the deflection signal generating means, and means for predicting a plurality of rotational angle direction ranges to be prepitted and means for predicting and correcting the adjacent groove distortion generated in the vicinity of the adjacent zone are added.

As a result, the PID prepits are preliminarily displaced in the outer peripheral direction in the track substantially inward of the zone, and the PID prepits in the adjacent zones on the inner peripheral side of the track are rotated in the rotational angle direction. By recognizing the range, the pregroove being formed is displaced and deformed in the outer peripheral direction,
In the track near the outer circumference of the zone, the PID prepits are displaced in advance in the inner circumference direction, and the range in the rotational angle direction of the PID prepits located in the outer circumference side adjacent zone of the track is predicted to be formed. The pre-groove is shifted and deformed in the inner circumferential direction to cut the optical disc master.

The optical disk master created by the above-described master creating apparatus has prepits formed at positions opposite to the PID pit position displacement direction predicted after completion of a single disk, based on a predetermined position in the radial direction of the PID prepits. ,
After the disc is completed, it will be deformed in the direction opposite to the pregroove distortion direction predicted.

As a result, the PID pit position that is inevitably generated by the subsequent process is displaced (varied).
And the phenomenon that the groove is deformed (distorted) due to the effect of the pre-pit portion of the adjacent zone is corrected in advance, and the relative position shift of the PID pit and the groove in the radial direction and the distortion of the adjacent groove are extremely small. Can provide a single unit.

Further, according to the present invention, means for recognizing a plurality of rotational angle direction ranges in which PIDs of a plurality of sectors are prepitted in the inner peripheral side adjacent zone and P of a plurality of sectors in the outer peripheral side adjacent zone are recognized.
Means for predicting a plurality of rotational angle direction ranges in which the ID should be prepitted, and means for generating a signal for correcting the distortion direction of the adjacent groove and the displacement (fluctuation) direction of the PID pit position which occur near the adjacent zone. And are provided.

The range recognized by the PID position recognizing means of the adjacent zone indicates the range of rotation angle in which the groove is deformed so as to be pushed out to the PID prepit portion of the inner peripheral side adjacent zone and the prepit portion of the outer peripheral side adjacent zone. Yes, the output of the signal generating means for correcting the distortion (deformation) of the adjacent groove can be passed only during the range of the range,
Displacement (fluctuation) of the passing output signal and the PID pit position
It is possible to combine the outputs from the signal generating means for correcting the above and apply them to the optical deflection element.

As a result, the groove is preliminarily deformed in the direction opposite to the direction in which the prepit portions of the adjacent zones are deformed (distorted), and in the direction opposite to the direction in which the PID pit position is displaced (varied). Since the optical disc master is produced in the shifted state, there is an effect that it is possible to supply an optical disc unit with extremely little distortion of adjacent groove and displacement of PID pit position.

Further, according to the present invention, a numerical value which is gradually reduced by a unique function using the number of elapsed tracks from the innermost track of the inner zone boundary to the central track of the zone and the outer zone boundary from the central track of the zone. A means is provided for storing, as a table, numerical values that are multiplied by a unique function using the number of remaining tracks toward the outermost track of the section.

By sequentially drawing out the table values of the storage means that gradually decreases and increases by the above-mentioned unique function for each rotation of the disk, the distortion direction of the adjacent groove and the displacement (fluctuation) direction of the PID pit position generated in the vicinity of the adjacent zone can be obtained. It becomes possible to use each as a signal of the direction to correct.

As a result, the optical disc master is created with the correction values that gradually reduce the correction amounts of the adjacent groove distortion and the PID pit position variation from the zone boundary portions of the inner and outer circumferences toward the center portion of the zone. There is an effect that it is possible to supply a single optical disc with high correction accuracy.

Further, according to the present invention, there is provided means for dividing a signal in a direction for correcting each of the distortion direction of the adjacent groove and the displacement (fluctuation) direction of the PID pit position generated in the vicinity of the adjacent zone, and the divisor to be given to the division means. And a storage means.

By individually setting the numerical values stored in the divisor storage means in units of zones, it is possible to correct the adjacent groove distortion and the PID pit position displacement of any size from the inner peripheral side zone to the outer peripheral side zone. It will be possible. As a result, an optical disc master is created with a correction value that absorbs the difference between the inner and outer circumferences of the entire disc, and there is an effect that a single optical disc with high correction accuracy can be supplied over the entire disc.

[0028]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments will be described below with reference to the drawings. FIG. 1 is a schematic block diagram of a master cutting system for a DVD-RAM disc.

An optical disc cutting master 250 having a surface coated with a photosensitizer is mounted on the rotary shaft of the spindle mechanism 205 of the laser cutting machine 200, and the LCM controller 206 is operated to emit a laser beam 209 of a constant light amount from the laser light source 201. Radiate, 250
Is rotated at a constant rotation speed, and the feed mechanism 204 is moved at a constant speed so as to obtain a predetermined track pitch.

The laser beam 209 is ON (beam transmitted) / OFF (beam blocked) modulated by an AOM (acousto-optic modulator) 202, and a small deviation (wobble) in the radial direction of the master 250 by an AOD (acousto-optic deflector) 203. Then, the light is irradiated as an extremely minute spot on the photosensitive surface of the cutting master 250 by the action of the objective lens 208 via the reflection mirror 207.

Here, the AOM drive signal 101 output from the formatter 100 is supplied as a modulation signal of the AOM 202, and the output signal AOD of the formatter 100 is also supplied.
By supplying the drive signal 102 as a deflection signal of the AOD 203, it is possible to cut an optical disc master of a predetermined format.

FIG. 2 shows the formatter 100 shown in FIG.
In the functional block diagram of, the two-sided buffer system is basically used in which the A side and the B side are switched every time the zone is switched. In addition,
The A side and the B side described here are different from the “A side” and the “B side” for distinguishing the front and back sides of the disk in the description relating to FIG. 16 and FIGS. It is a name for distinguishing the buffer surface of the surface buffer formatter.

A PC (personal computer) 103 for performing generation / modulation of sector address information, macro sequence control, etc., a frequency synthesizer 104 for supplying an A-side channel clock 116, a frequency synthesizer 105 for supplying a B-side channel clock 117, and I / F (interface) 119 receives the PC 103 control information, sector address pre-pit information, etc., and specifically controls the format, and the sequence controller 106 temporarily stores A-side physical sector address (PID) pre-pit information. A-side memory controller 107 for controlling read / write addresses and memory switching of the memory group 108 stored in the B-side memory group 110 and B-side memory controller 109 for the B-side corresponding to the A-side.
And the A-side memory group 108 and the B-side memory group 11
The edit circuit 111 that makes the output data sequence from 0 switchable or rearranged so that it can be cut in a predetermined format, and one of the two systems output from the edit circuit 111 is for generating the AOM drive signal. Modulated signal 124 converted into analog signal by DA converter (DAC) 112 and output buffer amplifier 12 for 50Ω drive
1 and the other of the editing circuit output systems is AOD
The output buffer amplifier 115 is for driving signals, and is analogized by the DA converter 122 and is added to the correction deflection signal output from the deflection correction circuit 300 by the addition circuit 114 and is driven by 50Ω to drive the addition signal 123.

The operation of FIG. 2 will be described below with reference to the flow chart of FIG. First, the personal computer (PC) 103 sets the channel clock frequency setting of the first cutting zone (usually # 0 zone) to the fa frequency synthesizer 104 via GPIB (general purpose interface bus) as a preparatory step. Do it.

At the same time, the PID pre-pit data, groove data, deflection data, etc. are transferred to the I / F 119.
After the transfer to the A-side memory group 108 via the controller 106 (131 in FIG. 4), the parameters and various data of the first zone are set to another synthesizer 105 and the data is transferred to the B-side memory group 110. Execution (132 in FIG. 4) (this is a preparation for allowing the start from the side A and the side B).

Next, it is determined whether the start operation to the PC 103 is performed on the A side or the B side (133 in FIG. 4), and if it is assumed that the B side is started, the PC 103 is started. Issues a B-side start command to the controller 106 (139 in FIG. 4) and sets the channel clock frequency setting of the next cutting zone (# 1 zone according to the normal example) to the fa frequency synthesizer 104.
Dedicated PID pre-pit data, groove data, deflection data, etc.
Transfer to A-side memory group 108 via 19 (140 in FIG. 4)
To do.

The controller 106 waits for the end of zone cutting (141 in FIG. 4), stops the operation of the B side (142 in FIG. 4), and if it is determined that the zone is not the final zone (143 in FIG. 4), the opposite side. At the same time when (here, A side) is quickly started (134 in FIG. 4), the PC 10
Notify 3 that the zone has changed.

Therefore, the PC 103 sets the channel clock frequency setting of the next cutting zone (# 2 zone according to the normal example) to the fb frequency synthesizer 105.
And the PID pre-pit data, groove data, deflection data, etc. together with the A-side memory group 108.
(140 in FIG. 4). Then controller 1
06 waits for the end flag of the A-side operation (136 in FIG. 4),
When the A side operation is stopped (137 in FIG. 4) and it is determined that the zone is not the final zone (138 in FIG. 4), the opposite side (here, B side) is activated (139 in FIG. 4), and PC1
Notify 03 that the zone has been switched.
Thereafter, while repeating the same flow, when it is judged that the cutting of the entire surface of the disc has been completed (138 or 143 in FIG. 4), a series of cutting operations is completed.

FIG. 3 shows the deflection correction circuit 300 described in FIG.
It is a functional block diagram showing an internal circuit of. The correction circuit 3
00 is a data selector 3 that switches an input signal such as a channel clock according to the surface (A or B) state during operation.
02, a byte counter 310 (1/43415 counter) for detecting the PID position of the zone adjacent to the outer peripheral side, a correction position (PID position) detection circuit 311 of the outer peripheral side adjacent zone, and a byte counter 32 of the currently executing zone.
0 (1/1523 counter) and current zone PI
D position detection circuit 313 and the byte counter 32
Current zone sector counter 321 (6 bit programmable 2) that counts CO (carry out) output of 0
CO) of the sector counter 321
Current zone track counter 322 for counting output
(11-bit programmable binary counter), zone counter (6-bit binary counter) 323 for counting the CO output of the track counter 322, correction track identification circuit 324, and correction position (PID position) of the inner peripheral side adjacent zone A detection circuit 317, a pit position displacement correction table 326, a pit position displacement correction data data selector 327, an adjacent groove distortion correction table 329, an adjacent groove distortion correction data data selector 330, and switching between distortion correction data and position displacement correction data. Data selector 331
A division circuit 332 for absorbing the radius dependence, a divisor table 318 for giving a divisor, and the division circuit 3
The DA converter 333 is configured by analogizing the output of 32 to generate the corrected deflection signal 301.

In the data selector used in this figure, the A input is selected as the Y output when the SEL input is at the low level, and the B selector is selected when the SEL input is at the high level.
The input is selected as the Y output.

The following description will be given assuming that the B side is in operation. Input signal B-side channel clock (BC
HCK) 117 is the frequency for the current zone (spindle speed 600 rpm, 4.7 GB-DVD-RAM # 2).
The frequency when cutting the zone is 11.651
04 MHz), and the A-side channel clock (A-CHCK) 116 at this time has a frequency for the next zone (12.0 corresponding to the # 3 zone when the previous example is taken over).
8256 MHz).

The input signals B-TN0, 10 are the number of tracks per zone of the current zone, and the input signals A-TN0,
10 is 11-bit data indicating the number of tracks per zone in the next zone, and input signals B-SN0 and 5 are the number of sectors per track in the current zone (27 sectors in # 2 zone). A-SN0 and 5 are the number of sectors per track in the next zone (28 sectors in # 3 zone).

Since it is assumed that the B-side is operating, the input signal B-RUN is at a high level, so the A-CHCK for the next zone is input to the CK (count clock) of the outer peripheral side adjacent byte counter 310. Since it has been selected, the counter 31
PID position pointed to by a value of 0 (count zero to 128
The outer peripheral side adjacent groove distortion correction position O-POS can be obtained by extracting (up to a byte equivalent count).

Since the B-CHCK of the current zone frequency is selected and input to the CK (count clock) input of the current zone byte counter 320, the byte counter 320 and the sector counter 321 (selected by the selector 302). B-SNs 0 and 5 designated by 1 and the track counter 322 (B selected by the selector 302)
-Counter for the numerical value specified by TN0, 10)
Are each in sync with the ongoing format operation.

The correction track identification circuit 324 uses the period in which the track counter 322 indicating the current ongoing track is from 0 to 255 as the inner peripheral side correction necessary period Z-IN.
And simultaneously outputs the lower 8 bits of the track counter 322 to ADR0, 7 as a table address as they are, and B-TN0, 10 indicating the number of tracks per zone of the current zone selected by the selector 302. The count value of 322 is subtracted, and when the difference becomes equal to or less than 255, the zone outer periphery side correction necessary period signal Z-OUT is output and the lower 8 bits of the subtraction result are output as ADR0, 7.

A PID signal matching the PID position in the current format extracted by the PID position detection circuit 313 is output, and the PID output signal is exclusive OR (EOR) with the [PID] side contact signal of the mode changeover switch 315. Circuit 3
EOR at 16.

At this time, the [PI of the switch 315 is selected.
If the D] side contact signal is at a low level, the PID output signal passes through as it is, and if the [PID] side contact signal of the switch 315 is at a high level, it is inverted (if it is at a high level, it becomes a low level, and at a low level. If there is, it goes to the high level) and the logical product (AND) circuit 314 passes the above-mentioned ZO
The UT signal and the Z-IN signal are the logical sum (OR) circuit 324.
The signal is ANDed with the signal ORed in and connected to the SEL input of the pit position displacement data selector 327.

The pit position displacement correction table 326, the adjacent groove distortion correction table, and the divisor table 318 use a rewritable IC-ROM and can be connected from the personal computer (103 in FIG. 2) to the serial interface R.
The configuration is such that each can be updated via S232C.

Further, the pit position displacement correction table 326
And the address of the adjacent groove distortion correction table 329 is
It has a 9-bit configuration in which the Z-OUT is added as the most significant bit to the upper bits of the ADR0 and 7, and 256 tracks for the inner circumference side and 256 tracks for the outer circumference side of the zone are read from the corresponding table. Table 3
18 is the Q output ZCT0, 5 of the zone counter 323.
By using as an address, it is possible to read out different numerical values for each zone.

The Y output of the pit displacement correction data selector 327 uses the correction values PIT0, 7 read from the pit position correction table 326 as the A input side of the data selector 327 and the offset B binary code on the opposite B input side. By inputting 7F (hexadecimal notation), which means zero, as a fixed value, the pit correction data PIT0, 7 is fixed when the SEL input terminal of the selector 327 is at a low level, and fixed when the SEL input is at a high level. Each zero is output and input to one of exclusive OR (EOR) circuits 328.

This means that the SEL of the selector 327 is
The input, that is, the output of the AND circuit 314 is determined by the setting of the switch 315 as to whether the signal level of the PID position portion of the current zone becomes the high level or the low level. It is possible to select whether to correct the portion, that is, the groove portion.

In the case of the groove correction mode, the correction values PIT0 and PIT7 are straight binary codes and the polarities thereof are inverted by the action of the EOR circuit 328. That is, the direction is reversed between the case of directly correcting the pit position and the case of performing the groove side shift correction.

On the other hand, in order to detect the correction position (adjacent PID position) of the inner peripheral side adjacent zone, the count values of the counters 320 and 321 for the current zone are detected by the detection circuit 31.
7 to input the corrected position output I of the groove distortion on the inner circumference side.
-Predictive output of POS.

The I-POS is the inner peripheral side correction required period Z-
AND is performed by AND in the AND circuit 319, and the outer peripheral side correction required period Z-OUT and the outer peripheral side adjacent groove distortion correction position output O-POS are A in the AND circuit 312.
The ND-ed signal is OR'd by a logical sum (OR) circuit 325, and the correction position is connected to the SEL input terminals of the data selector 330 and the data selector 331 as a high-level pulse signal for a necessary period on the inner and outer circumference sides. It

The numerical values XC0, 7 derived from the adjacent groove distortion correction table 329 are read out through the same process as PIT0, 7 of the pit position displacement correction table 326, and the adjacent groove distortion correction data selector 330 is read.
While the SEL input of is high level, the above numerical value XC0, 7
However, during the low level period, a fixed value of zero (7 in hexadecimal notation)
F) are respectively selected and connected to the B input side of the correction table switching data selector 331.

As a result, the correction data for the adjacent groove distortion is selected only during the adjacent groove distortion correction period and is input as the numerator term of the zone dependence correction division circuit 332.
The value obtained by dividing the output value of the divisor table 318 (however, the dividend is calculated as an absolute value and then calculated and returned to the original numerical form after the calculation) is converted into an analog value by the DA converter 333, thereby forming a correction deflection signal.

FIG. 7 is a line graph showing an example of the adjacent groove distortion correction table (329 in FIG. 3). The horizontal axis shows the number of grooves in the zone, the right side is the outer peripheral direction, and the vertical axis shows the correction coefficient, and the larger the number, the larger the correction amount, and the exponentially large value toward the zone boundary. Becomes

These values are experimentally obtained using parameters such as differences in manufacturing equipment and differences in members used, and are stored in the control personal computer (103 in FIG. 2) in the form of a database. . Note that P
The ID position displacement correction table (326 in FIG. 3) is also made into a database by a similar method.

FIG. 5 shows the exposure state and formatter of the master disc of a DVD-RAM disc when cutting the master disc of the conventional system or various correction tables (326 and 329 in FIG. 4) all set to zero. 1 of FIG.
0) is a diagram showing an output signal, and the horizontal axis direction corresponds to the rotation angle of the cutting master.

FIG. 4D is a view for explaining the exposure state by enlarging the vicinity of the disc index 401 on the cutting master. Here, the downward direction of the drawing is the inner peripheral side of the master, and the feeding mechanism (204 in FIG. 1) is moving at a constant speed from the lower part to the upper part of the drawing.

First, the third cutting of the remaining zone # (k-1) (AOM drive signal 101 shown in FIG.
And the waveform diagram of the AOD drive signal 102 correspond to each other)
In the land PID402-L in which the address information of the # 0 sector of the land track starting from the point A is pre-pitted, the pit row is exposed to a position shifted from the track center by an amount equivalent to ½ track (see FIG. 102) is set to a positive potential.

A pit forming pulse train is applied to the same 101)
Then, in the groove PID402-G in which the address information of the # 0 sector of the groove track is pre-pitted, the pit train is exposed to the place where the track P1 is displaced from the track center by an amount corresponding to ½ track (in the same figure ( 3) 102 is applied with a negative potential.

A pit forming pulse train is applied to 101)
Then, the groove (guide groove) 403 subsequently exposes the land PID of the next sector for a period (102 in FIG. 3C is set to zero potential).

While periodically performing the operation of applying a constant positive potential to the same 101), all operations are performed immediately after the disk makes one rotation and passes the index 401 at the disk-in until it passes the index 401 again. The land track 404 is formed by interrupting the above operation.

When the zone #k area is entered while repeating the above operation, the frequency of the cutting channel clock is switched to a slightly higher frequency (see, for example, FIG. 3).
In the example described in, the change from 11.21952 MHz in zone # 1 to 11.65104 MHz in zone # 2).

In this state, when the cutting operation similar to that of the zone # (k-1) is executed (the waveform diagrams of the AOM drive signal 101 and the AOD drive signal 102 shown in (2) of the figure correspond to each other), 1 sector length (angle) as shown
Becomes shorter, PID start point (angle) after # 1 sector
Will no longer match the previous zone.

Then, when the zone # (k + 1) is entered,
Channel clock frequency is higher (eg
In the explanation example of FIG. 3, when the cutting operation similar to the above-mentioned zone # (k-1) is executed in the state of changing from 11.65104 MHz of zone # 2 to 12.08256 MHz of zone # 3 (see FIG. The waveform diagrams of the AOM drive signal 101 and the AOD drive signal 102 shown in) correspond to each other.) As shown, the length (angle) of one sector is further shortened, and the PID start point (angle) after # 1 sector is It will be further shifted.

FIG. 6 shows various correction tables (326 in FIG. 4).
And 329) valid, that is, the pit position displacement is set to P in advance.
Shift correction of the ID pre-pit position in the opposite direction of displacement (Fig. 3
Switch 315 is set to [PID] side),
At the same time, the groove is deformed and corrected in the direction opposite to the distortion direction of the adjacent groove distortion, and the exposure state to the cutting master (250 in FIG. 1) and the formatter (100 in FIG. 1) when the master of the DVD-RAM disc is cut. It is a figure showing an output signal, and a horizontal axis direction corresponds to a rotation angle of a cutting master.

In FIG. 5 (5), the starting point is the # 0 sector near the disk index 401 on the cutting master.
It is a figure for omission on the way and explaining an exposure state near PID of #n sector.

Here, the downward direction of the drawing is the inner peripheral side of the master, and the feeding mechanism (204 in FIG. 1) is moving at a constant speed from the lower part of the drawing to the upper part, which will be described from the lower direction of the drawing.

The third cutting of the remaining zone # (k-1) (AOM drive signal 101 and AO shown in (4) of the same figure)
(The waveform diagram of the D drive signal 102 corresponds) indicates that the PID 402-L in which the address information of the land track # 0 sector starting from the point A is prepitted is shifted from the track center by an amount equivalent to ½ track. The pit train is exposed to the spot (102 in FIG. 4 (4) is set to a positive potential and a pit forming pulse train is applied to 101).

Subsequently, in the PID 402-G in which the address information of the # 0 sector of the groove track is pre-pitted, the pit row is exposed to the place where it is shifted from the track center by an amount corresponding to ½ track in the inner peripheral direction ((Fig. 4) 102 is set to a negative potential, and a pit forming pulse train is applied to the same 101).

Note that starting from the index 401 #
The PID pit of 0 sector is not displaced, so the pit position is not corrected.

Subsequently, a groove (guide groove) 403 is generated by exposure for a period up to the PID position of the next sector (a constant positive potential is applied to 101 in FIG.
2 is set to zero potential), but at the predicted rotation angle position of the PID pits in the outer peripheral side adjacent zone, the deflection correction is performed in advance in the direction opposite to the distortion direction of the adjacent groove by ΔSg (102 in FIG.
refer.

After that, for example, when reaching the (PID) position of the #n sector and forming a PID pit, Δdp-1 or Δdp-g is subtracted from the deflection signal as shown by 102 in FIG. A PID prepit is formed at a position shifted to the inner circumference side of the disk.

After that, immediately after the disk makes one rotation and passes the index 401 at the disk-in, the above operation is interrupted and the land track 404 is formed until the index 401 is passed again.

When the zone #k area is entered while repeating the above operation, the frequency of the cutting channel clock is switched to a slightly higher frequency (see, for example, FIG. 3).
In the example described in, the change from 11.21952 MHz in zone # 1 to 11.65104 MHz in zone # 2).

In this state, the cutting operation is performed on the inner peripheral side boundary portion (within this embodiment, within 256 tracks from the zone start point) (waveform diagrams of the AOM drive signal 101 and the AOD drive signal 102 shown in FIG. Corresponding), the length (angle) of one sector becomes shorter as shown in the figure, and the PID start point (angle) after # 1 sector does not match the previous zone.

Here, as shown by the waveform 102 in FIG. 3C, the deviation amount of the PID pit is Δdp-1 or Δ.
By adding dp-g, deviation formation is performed on the outer peripheral side of the predetermined position, and ΔSg is subtracted in the PID portion of the inner peripheral side adjacent zone in which the exposure formation has already been completed to perform deformation correction on the inner peripheral side.

When the zone #k approaches the outer boundary (the number of remaining tracks is 256 or less in this embodiment), the outer boundary cutting is indicated by the AOM drive signal 101 shown in FIG.
And the waveform diagram of the AOD drive signal 102, that is, the same operation as the above-mentioned (4) in FIG. 4 is performed, although the PID and the like are different due to the higher frequency of the cutting channel clock.

The PID pit of the # 0 sector starting from the disc index 401 is 1/2 track (+ Tp / 2) from the groove center to the outer circumference side to 1/2 track (-Tp / 2) to the inner circumference side. Accurately shift and form the exposure, and in the PID predicted position period tso of the outer peripheral side adjacent zone, the groove is formed by displacing by Δsg in the outer peripheral direction.
The PID of the n-sector is formed at a position shifted inward by an amount equal to Δdp-1 and Δdp-g phases from the PID formation position of the # 0 sector.

Further, when the zone # (k + 1) is entered, the AOM drive signal 101 and AOD shown in (1) of FIG.
As shown in the drive signal 102, the PID prepits and the grooves are formed while performing the same correction as the inner peripheral side boundary portion operation described in FIG.

FIG. 10 is a view for explaining the pre-pit PID portion vicinity of the stamper made from the optical disc cutting master prepared by the above-mentioned method, and explaining the PID portion position displacement correction and the adjacent groove deformation correction state.

FIG. 7A shows the boundary between adjacent zones on the outer peripheral side. In the period of the prepit portions PID-L and PID-G of the CAPA format, the groove 403 is formed by correcting the distortion of the adjacent groove and deformed inward by the distance ΔCsg. At the same time, the prepits PID (PIL-L and PID-P
In ID-G), the PID center has a distance ΔCd from a predetermined position.
It is formed by shifting to the inner peripheral side by p.

FIG. 9B shows the zone center (middle circumference). Since the amount of PID pit displacement or adjacent groove distortion is extremely small in the central portion, it is not necessary to correct it. Therefore, the deviation amount Wcapa between the PID center and the groove track center or the land track center is at half the track pitch TP. The groove 403 is formed accurately and without any correction deformation.

FIG. 11C shows the boundary portion of the adjacent zone on the inner circumference side. In the direction opposite to the outer peripheral side of (a), that is, Δ more than a half track from the center line of the groove 403.
Prepitting is performed so that the corrected PID center is located at a position separated by Cdp, and the adjacent groove is also subjected to the correction distortion of the distance ΔCsg toward the outer peripheral side.

In the above, the embodiment has been described with a focus on the master disc manufacturing process. Next, referring to FIG. 11, a DVD-RAM
A general manufacturing process flow until the completion of the optical disc will be described. In the glass master manufacturing process 501, a photosensitive agent is uniformly applied to the surface of a glass disk that has been processed to be extremely flat. The surface of the glass disk is exposed to light in a predetermined format by using a master cutting system as shown in FIG. 1) forming prepits and pregrooves with a depth.

In the stamper manufacturing step 502, a metal mold (stamper) having the prepits and pregrooves transferred thereto is manufactured by plating a metal such as nickel on a glass master having the prepits and pregrooves formed thereon.

In the replica manufacturing process 503, a predetermined gap (0.6 mm) is formed between the concave-convex forming surface of the mold (stamper).
Polycarbonate (PC) between flat plates placed in parallel with
A resin is press-fitted, and after the PC resin is cured, it is peeled off from the stamper, whereby a replica disk having the same uneven surface as the glass master is made.

In the glass master disc manufacturing step 501, it is necessary to perform the formatting in advance in consideration of the reduction rate, because the PC resin is reduced in a slight amount in the curing process. For example, the adjacent groove distortion correction amount ΔCsg in FIG.
Is required to be 100 nm, distortion correction corresponding to 100.8 nm should be performed.

In the sputtering process 504, a large number of replica discs (substrates) are thus formed so that the reflection film (layer) member, the heat dissipation film (layer) member, the layer change film (layer) member, etc. have a multilayer structure. Sequential vapor deposition is performed to form a so-called recording film.

As the productivity of the vapor deposition process is improved, that is, the heat generation increases in inverse proportion to the time required for the sputtering process, and as described with reference to FIG. 8, the temperatures of the base substrate (replica) and the recording film are increased. The amount of warp caused by the difference or the difference in expansion rate also becomes large, and as a result, the amount of CAPA center deviation and the amount of adjacent groove distortion become large.

In the laminating / finishing step 505, finishing operations such as back-to-back laminating of 0.6 mm-thick optical disk single plates with recording films attached, printing and sticking are performed, and a 1.2 mm-thick The appearance of the double-sided optical disk will be adjusted.

In the present embodiment, the two optical disk single plates having the recording film are bonded to each other with the recording film side inside, but the optical disk single plate having the recording film and the dummy substrate having no recording film are attached. It is also possible to attach and so that the recording film side is the inside.

Through these steps, in the inspection step 506,
Not only the evaluation of items specified by the Japanese Industrial Standards (JIS) and the check of appearance, but also the evaluation of reliability and recording / reproducing characteristics are comprehensively performed before shipment.

FIG. 12 shows the above-mentioned inspection process (50 in FIG. 11).
6) and a functional block diagram showing an evaluation device used in the design stage, but in order to avoid complication, parts such as a recording circuit system and a controller which are not considered to be directly related to the present invention are omitted from illustration and description.

A laser beam 554 having a wavelength of 660 nm emitted from a semiconductor laser 553 driven by a laser driving circuit 552 having an APC (Automatic Power Control) circuit passes through a half mirror 555,
The direction is changed by the reflection mirror 556, the light enters the two-dimensional actuator 557, and the objective lens 558 acts to focus it as a minute spot on the recording film surface of the optical disc unit 400.

The optical disk 400 is fixed to the spindle motor 551 and is rotating at a constant speed, and the reflected light 554 has the light / dark information of the film surface of the optical disk 400 and the diffracted light information by the groove (pre-groove) which changes moment by moment. S follows the opposite optical path, is reflected by the half mirror 555, and
It is incident on the split detector 559.

The photodiodes of a and b and c and d constituting the four-division detector 559 each independently output a current proportional to the intensity of the light incident thereon, and the current-voltage conversion amplifier 560 outputs the current. It is converted into a voltage signal and becomes four input signals to the arithmetic circuit 561.

A tracking error signal [TE = (a + b)-(c + d)] which is the first output of the arithmetic circuit 561.
Is subjected to phase guarantee and current amplification by the tracking control circuit 562, and drives the horizontal drive coil of the two-dimensional actuator 557 to move the objective lens 558 in the radial direction, thereby focusing the focused spot of the laser beam 554. Guide (tracking) so as to maintain the center of the groove or the center of the land (between the grooves).

The second output focus error signal [FE = (a + c)-(b + d)] of the arithmetic circuit 561!
Performs phase assurance and current amplification by the autofocus circuit 563, then drives the vertical drive coil of the two-dimensional actuator 557, the objective lens 558 moves up and down, and the laser beam 554 causes the optical disc 40 to move.
Control (autofocus) is performed so that light is focused on the recording surface of 0 under optimum conditions.

The pit signal (SUM = a + b + c + d) which is the third output signal of the arithmetic circuit 561 is light and dark information on the recording film surface of the optical disc 400, and is mainly for the purpose of detecting the presence or absence of prepits or recording pits. Use the above tracking error signal (TE)
Is used as a tracking error monitor signal 565 via a low pass filter circuit 564 that removes high frequency components such as groove wolves.

FIG. 13 shows the above-mentioned evaluation of a DVD-RAM disc alone manufactured without performing adjacent groove distortion correction and PID pit position displacement correction (CAPA deviation correction) (fixing the correction deflection signal 301 of FIG. 2 to zero potential). TE monitor signal (Fig. 12) when evaluated using the device (Fig. 12)
565) in a specific rotation angle position. The horizontal axis represents time, and the spindle motor (see FIG.
551) rotates at a constant speed in the zone and is usually controlled so that the number of revolutions becomes slower every time the zone moves to the outer peripheral side, but this time for convenience, waveform observation without switching the above number of revolutions is performed. did.

Zone # 1 (second zone from the inner circumference side)
And the lower part of the drawing is the disk (40 in FIG. 12).
0) in the inner circumferential direction, the second groove (# 156 of zone # 0 from zone boundary to the inner circumferential direction in order from the bottom).
TE monitor signal 565-0-1564 when tracking to 4 tracks), TE monitor signal 565-0-1564 when tracking to a groove (# 1566 track of zone # 0) at the zone boundary, and zone # 1 TE monitor signal 565 when tracking to the innermost groove (# 0 track of zone # 1) of
-1-0, the TE monitor signal 565-1-2 when tracking to the second groove (# 2 track of zone # 1) from the inner circumference side of zone # 1, and the central portion in the radial direction of zone # 1. TE monitor signal 565 when tracking to the groove (# 782 track of zone # 1)
-1-782 and TE monitor signal 565-1-1564 when tracking to the second groove (# 1564 track of zone # 1) from the outer peripheral side of zone # 1
And the outermost groove of zone # 1 (# 15 of zone # 1
66-track) and TE monitor signal 565-1-1566 and TE monitor signal 656-when tracking to the innermost circumferential groove (# 0 track of zone # 2) of the adjacent zone # 2 on the outer peripheral side. 2 and 2, respectively.

Zone # 0 PIDL (waveform portion when a laser spot passes through a PID pit row portion formed at a position wobbled to the outer peripheral side by one-half track from the track center) and PIDG (from the track center At the time position (PID pit position of zone # 0) where the waveform portion when the laser spot passes through the PID pit row portion formed at a position wobbled to the inner peripheral side by the amount equivalent to ½ track appears (zone PID pit position), Although the noise waveforms ΔCS-0 and ΔCS-2 due to the adjacent groove distortion of # 1 were observed, the noise waveform due to the adjacent groove distortion was not observed in the TE monitor signals 565-1-782 at the center of the zone.

Zone # 2, which is an adjacent zone on the outer peripheral side
, The noise waveform ΔCS-0 at the PID pit position of zone # 0 due to the above-mentioned inner circumferential side adjacent groove distortion.
Waveform ΔCS-1 due to adjacent groove distortion in the opposite direction to
566 has appeared. Although it is not clear in the drawing, it has been confirmed that the vertical symmetry of the PIDL and the PIDG collapses as it approaches the zone boundary.

FIG. 14 shows a noise waveform due to the adjacent groove distortion (ΔCS-0 and ΔCS-2 and ΔCS in FIG. 13).
-1566) is plotted in a graph. It was confirmed that a maximum of plus or minus 150 nm of adjacent groove distortion was generated. The correction table as shown in FIG. 7 is derived based on this data.

FIG. 15 shows a TE monitor signal when a single DVD-RAM disk prepared by performing adjacent groove distortion correction and PID pit position displacement correction (CAPA deviation correction) is evaluated using the evaluation device (FIG. 12). In the waveform diagram at the specific rotation angle position (565 in FIG. 12), the specific method, the horizontal axis, etc. are the same as those in FIG.

Adjacent groove distortion of the TE monitor signal 565-1-782 is not observed at all as in the case of FIG. 13, and the ΔCS-0 of the TE monitor signal 565-1-0 and the TE monitor signal 565-1-2. ΔCS-2,
Furthermore, the ΔCS of the TE monitor signal 565-1-1566
-1566 was hardly observed.

Further, the vertical symmetry of the PIDL waveform and the PIDG waveform was also greatly improved, and it was confirmed that the PID pit rows were arranged symmetrically with respect to the track center.

When the recording film of the DVD-RAM disc used here was peeled off and returned to the state of the disc substrate, it was observed.
It was possible to confirm from the waveform observation that the ID pit position displacement was corrected. Next, an embodiment corresponding to higher density recording / reproducing will be described below. FIG.
Is a DVD-RAM disc or International Standard (ISO)
FIG. 3 is a diagram schematically expressing the relationship between the cross-sectional structure of an attachment type disc such as a magneto-optical (MO) disc defined in 1 above and the irradiation laser beam.

Thickness t0 (0.6 for DVD-RAM)
mm) of the recording layer of the first substrate 500A (a layer in which recording members are sputtered in layers) and the recording layer of the second substrate 500B of the same thickness t0 are faced to each other and are bonded by an adhesive layer (single-sided). In the case of a recording disc, the second substrate 50
0B is used as a blank substrate having a thickness t0 and no treatment.

The recording / reproducing laser beam 554 is irradiated from the substrate side, and the focal length f is maintained so that it is condensed on the recording layer on the irradiation surface side by the action of the objective lens 558. As a result, the influence of scratches and dust on the disc surface can be minimized, and a sufficient gap can be secured between the lens surface and the disc surface, ensuring reliability as a recording medium. .

FIG. 17 is a diagram showing the relationship between the focal length f and the numerical aperture (NA) of the lens 558. Circular parallel light of radius r is converged at an angle of 2θ, and the length to the intersection is the focal length f. Since the numerical aperture is a sine function (NA = Sinθ) of this angle θ, the focal length f can be calculated by the following mathematical formula 1 (note that in order to improve the calculation accuracy, the refractive index of the substrate member is It is necessary to take into account such as).

[0115]

[Equation 1] Further, the spot size ω on the light collecting surface is generally expressed by the following mathematical formula 2. That is, it is proportional to the wavelength λ of the laser light and inversely proportional to the numerical aperture NA.

[0116]

[Equation 2] FIG. 18 shows that the radius r of the laser beam incident on the lens is 2 m.
9 is a table summarizing the relationship between the numerical aperture NA and the focal length f when m is assumed, the name of each specific example, the wavelength λ, and the spot diameter ω.

When NA = 0.4, f is 4.6 mm, and a typical example is CD-R (rewritable compact disc), the wavelength λ is 830 nm,
The spot diameter ω is 2.1 μm. When NA = 0.55, f = 3 mm, the wavelength λ is 780 nm, and the spot diameter is ω.
Is 1.4 μm. The wavelength λ of the DVD-RAM is 65
At 0 nm, the spot diameter ω is 1.1 μm. Further, the next-generation disc currently under development aims to realize a higher-density optical disc by reducing the spot diameter ω to 0.6 μm by combining a high NA lens blue laser. However, the focal length f at this time was shortened to 1.2 mm, which made the structure of FIG. 16 impossible.

Therefore, a method of applying a thin protective layer on the recording layer of the substrate and irradiating a laser spot for recording / reproducing from the protective layer side is being studied. FIG. 19 is a schematic diagram of a cross-sectional structure of a disk compatible with a high NA lens.

Double-sided molding substrate (replica) 60 with plate thickness t0
0 side A recording layer in which a plurality of recording film members are laminated on both sides of 0 and B
A surface recording layer is provided, a surface t protective layer 601-A made of a transparent resin having a thickness td (for example, 0.1 mm) is attached to the surface a recording layer side, and a transparent resin having the same thickness td is provided on the opposite surface. The B-side protective layers 600-B made are attached respectively.

The recording / reproducing light spot irradiates the laser beam 554 from the protective layers 600-A and 600-B side via the high NA objective lens 558-h. The focal length f at this time is 1.2 mm in the case of NA = 0.85 in FIG.

FIG. 20 is a flow chart showing the flow of manufacturing steps of the above-mentioned high NA compliant disk which is compatible with CAPA shift and adjacent groove distortion correction. CAPA above
It has already been described that the displacement and the adjacent groove distortion are caused by the substrate deformation (warping) due to the heat generation of the recording film in the sputtering process. Since it is extremely difficult to simultaneously deposit (sputter) both sides of the single-plate structure disc shown in FIG. 19 at the current state of the art, the following description will be made on the premise that each side is sequentially deposited.

First, a glass master disk preparation 611-A for a surface on which film formation is performed in advance (provisionally referred to as A surface) is performed, and then a stamper preparation 612-A for a film formation surface on advance (A surface) is performed. On the other hand, after the glass master making 611-B for the surface on which film formation is performed later (provisionally referred to as B surface), the surface on which film formation is performed later (B surface)
A stamper is created 612-A. Here, the CAPA shift correction amount and the adjacent groove distortion correction amount at the time of the master cutting performed in the above-mentioned B-side glass master creating step 611-B are the same as the master cutting performed in the A-side glass master creating step 611-A. A relatively small value (or almost no correction) is set as compared with the same correction amount of.

The stamper forming steps 612-A, 612
A double-sided replica substrate is manufactured 613 using the two stampers prepared in B. At this time, a visible marking is provided to indicate which surface is the preceding film-forming surface (basically outside the innermost peripheral frame at the time of cutting the master). The double-sided molding replica substrate is set in a sputtering apparatus so that the preceding film formation surface is located at a position where sputtering is possible, and the front side film sputtering 614 is performed. The surface side film sputtering 615 is performed. After that, a thin (0.1 mm in the embodiment) transparent resin protective layer formation 616 is performed on both sides of the film-formed replica substrate, and a finishing / inspection step 61 is performed.
Completed after 7.

Even in the case of a high NA compliant optical disc, after the film is formed on the single-sided molding replica and a protective layer is attached,
It has been confirmed that this can also be achieved by sticking the sheets back to back (recording layer / protective layer surface facing outward).

Furthermore, it has been confirmed that the CAPA shift correction amount and the adjacent groove distortion correction are effective means even in the case of a four-piece bonded disc such as the one-sided two-layer recording system.

FIG. 21 is a schematic cross-sectional structure diagram of another example of a disk compatible with a high NA lens. In this example, one substrate 6
A side recording layer and A side protective layer 601-A are sequentially formed on the substrate 00, and the B side recording layer and B side are formed on the other substrate 600.
The surface protection layer 601-B is sequentially formed, and the substrates 600 are superposed so that the substrates 600 are on the inside, and are integrally bonded with an adhesive. This disc is also irradiated with a recording / reproducing laser beam 554 from the protective layer 601 side.

In the optical disk of each of the above-described embodiments, the substrate is, for example, a polycarbonate resin, an epoxy resin, a polyetherimide resin, a polyethersulfone resin, a polyphenylene sulfide resin, a polyalate resin, a polyetherketone resin, a polyethernitrile resin, a polyene resin. Methylpentene resin, polystyrene resin, polymethylmethacrylate resin, amorphous polyolefin resin and the like are used.

Examples of the phase change recording layer include Sb-
Sc-based alloy, Ge-Sb-Te-based alloy, Ag-In-S
A b-Te based alloy, an In-Sb-Te based alloy, or the like is used. As the magneto-optical recording layer, for example, Tb-Fe-
Co-based alloy or the like is used.

As the protective layer, for example, an ultraviolet curable resin or the like is used. Examples of the ultraviolet curable resin include radical polymerization type and ionic polymerization type organic compounds, for example, neofunctional glycol acrylate, hexanediol diacrylate, trimethylolpropane triacrylate, polyfunctional monomers such as pentaerythritol triacrylate, and lauryl acrylate, A composition in which a photoinitiator such as benzophenone, benzyldimethylketal, or methylbenzoylformate is added to a mixture of monofunctional monomers such as 2-ethylhexyl acrylate is used.

Examples of the adhesive include acrylic resin, polyolefin resin, polyethylene terephthalate resin,
Polycarbonate resin, epoxy resin, ethylene-vinyl acetate copolymer, ultraviolet curable resin, etc. are used.

In the case of an optical disc compatible with high density recording / reproduction, the length of the shortest pit is 0.13 to 0.23 μm,
A track pitch of 0.16 to 0.33 μm is suitable.

Further, when the adhesive layer or the protective layer and the recording layer were peeled off from the single optical disk manufactured in the above-mentioned embodiments, and the waveform was observed using the evaluation device (FIG. 12), the CAPA shift correction and the adjacent It was possible to confirm the situation where the groove distortion correction was applied by a desired value.

According to the present embodiment, in both the bonded disc and the single plate disc, 256 tracks from the inner zone boundary and 256 tracks from the outer zone zone, that is, PID prepits are recorded. The wobble track center of the CAPA format is aligned with the center of the groove (guide groove) by previously correcting the pit position or the groove center by correcting the displacement only during a period when the displacement is large, and the adjacent groove distortion is stable. It is possible to realize a 4.7 GB type DVD-RAM disk alone having both tracking and recording stability.

[0134]

According to the present invention, since it is not affected by heat generation or the like in the manufacturing process of an optical disc having a structure capable of detecting both wobble track error detection and push-pull track error detection by the zone division type, As a result, the manufacturing time can be shortened, and an inexpensive and highly reliable optical disk unit can be provided.

[Brief description of drawings]

FIG. 1 is a schematic block diagram of an optical disc master cutting system.

FIG. 2 is a functional block diagram of a formatter.

FIG. 3 is a functional block diagram of a deflection correction circuit.

FIG. 4 is an operation flowchart of the formatter.

FIG. 5 is a diagram showing a conventional master exposure state and a formatter output waveform.

FIG. 6 is a diagram showing an exposure state of a master disc to which deflection correction has been added and a formatter output waveform.

FIG. 7 is a line graph showing an example of an adjacent groove distortion correction table.

FIG. 8 is a schematic diagram of a single DVD-RAM for explaining the problem.

FIG. 9 is an explanatory diagram of PID portion position displacement and adjacent groove deformation.

FIG. 10 is an explanatory diagram of PID portion position displacement correction and adjacent groove deformation correction.

FIG. 11 is a flowchart of a manufacturing process of a DVD-RAM disc.

FIG. 12 is a functional block diagram of a DVD-RAM disk evaluation device.

FIG. 13 is a waveform diagram of a DVD-RAM disc prepared by the conventional method.

FIG. 14 is a graph showing the amount of adjacent distortion of a DVD-RAM disc prepared by the conventional method.

FIG. 15 is a waveform diagram of a DVD-RAM disc created by the method of the present invention.

FIG. 16 is a schematic diagram showing the relationship between the cross-sectional structure of a bonded disc and a light spot.

FIG. 17 is an explanatory diagram showing a relationship between a focal length f and a lens numerical aperture (NA).

FIG. 18 is a table summarizing the relationship between the numerical aperture and the focal length, the wavelength λ, and the spot diameter ω.

FIG. 19 is a schematic diagram showing a cross-sectional structure of a disk compatible with a high NA lens.

FIG. 20 is a flowchart showing a flow of manufacturing steps of a high NA compliant disk.

FIG. 21 is a schematic diagram showing a cross-sectional structure of another disk compatible with a high NA lens.

[Explanation of symbols]

100 Formatter 101 AOM drive signal 102 AOD drive signal 103 Personal computer 104 Frequency synthesizer for A side 105 Frequency synthesizer for B side 106 Formatter sequence controller 108 A side memory group 110 B side memory group 116 A-CHCK (for A side cutting) Channel clock) 117 B-CHCK (channel clock for B-side cutting) 200 LCM (laser cutting machine) 201 laser light source 202 AOM (acousto-optic modulator) 203 AOD (acousto-optic deflector) 204 feed mechanism 205 spindle mechanism 206 LCM controller 250 Cutting Master 300 Deflection Correction Circuit 301 Correction Deflection Signal 310 Outer Side Adjacent Bit Counter 311 Outer Side Adjacent Correction Position Detection Circuit 313 Current Zone PID position detection circuit 317 Inner circumference side adjacent correction position detection circuit 318 Divisor table 320 Current zone byte counter 321, Current zone sector counter 322 Current zone track counter 323 Zone counter 324 Correction track identification circuit 326 Pit position displacement correction table 327 Pit position displacement Data selector 329 Adjacent groove distortion correction table 330 Adjacent groove distortion data selector 331 Correction table switching data selector 332 Zone dependency correction division circuit 400 Optical disk single 400-S Optical disk single film surface 401 Disk index 402 PID 402-L land Address PID 402-G Groove Address PID 403 Groove 404 Land track 500A A-side substrate 500B B-side substrate 553 Semiconductor laser 55 4 Semiconductor laser beam 557 Two-dimensional actuator 558 Objective lens 558h High NA objective lens 559 Four-division detector 561 Arithmetic circuit 562 Tracking circuit 563 Autofocus circuit 565 TE monitor signal 600 Substrate 601-A A surface protection layer 601-B B surface protection layer

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Masahide Yagi             Hitachima, 1-88, Torora, Ibaraki City, Osaka Prefecture             Within Kucsel Co., Ltd. (72) Inventor Katsuhiro Kishigami             Hitachima, 1-88, Torora, Ibaraki City, Osaka Prefecture             Within Kucsel Co., Ltd. (72) Inventor Naoki Kitagaki             Hitachima, 1-88, Torora, Ibaraki City, Osaka Prefecture             Within Kucsel Co., Ltd. (72) Inventor Masashi Suenaga             Hitachima, 1-88, Torora, Ibaraki City, Osaka Prefecture             Within Kucsel Co., Ltd. F-term (reference) 5D090 AA01 BB01 CC01 DD03 EE02                       FF17 GG17 KK20                 5D121 BB21 BB38

Claims (13)

[Claims] 1. A laser light source, a rotating mechanism for rotating at a predetermined speed a disc-shaped cutting master having a surface coated with a photosensitizer that reacts to the wavelength of a laser beam emitted from the laser light source, and the photosensitive master for the cutting master. An objective lens for converging a laser beam emitted from the laser light source into a spot on a surface, a feeding mechanism for moving the converged laser spot in a radial direction of the cutting master at a predetermined speed, and a pre-groove for guiding a track. Signal and physical address information (PID) pre-pit signal in a predetermined format, a modulation signal generating means, an optical modulating means which uses the output signal of the modulation signal generating means as a control input, the laser spot of the cutting master disk. Predetermine timing information, direction information, and size information for shifting in the radial direction Optical disc master having a deflection signal generating means having means for generating in the above format and a means for correcting displacement of a physical address information (PID) pit position, and an optical deflecting means having an output signal of the deflection signal generating means as a control input. In the creating apparatus, a means for recognizing a plurality of rotation angle direction ranges in which the physical address information (PID) of the inner peripheral side adjacent zone is prepitted, and a plurality of rotations for which the physical address information (PID) of the outer peripheral side adjacent zone is to be prepitted An apparatus for producing an optical disk master, wherein means for predicting an angular range and means for correcting adjacent groove distortion occurring in the vicinity of an adjacent zone are added to the deflection signal generating means. 2. The optical disk master making apparatus according to claim 1, wherein an adjacent groove distortion correcting data table for correcting the adjacent groove distortion is provided, and the adjacent groove distortion correcting data that matches the creating conditions of the optical disk master is recorded. An optical disk master creating apparatus, which selects an adjacent groove distortion correction data table to create an optical disk master. 3. A laser light source, a rotating mechanism for rotating at a predetermined speed a disc-shaped cutting master having a surface coated with a photosensitizer that reacts to the wavelength of a laser beam emitted from the laser light source, and a photosensitizer for the cutting master. An objective lens for converging a laser beam emitted from the laser light source into a spot on a surface, a feeding mechanism for moving the converged laser spot in a radial direction of the cutting master at a predetermined speed, and a pre-groove for guiding a track. Signal and physical address information (PID) pre-pit signal in a predetermined format, a modulation signal generating means, an optical modulating means which uses the output signal of the modulation signal generating means as a control input, the laser spot of the cutting master disk. Predetermine timing information, direction information, and size information for shifting in the radial direction Optical disc master having a deflection signal generating means having means for generating in the above format and a means for correcting displacement of a physical address information (PID) pit position, and an optical deflecting means having an output signal of the deflection signal generating means as a control input. In the creation device, the elapsed track number recognition means for recognizing the number of tracks from the cutting start side zone boundary portion to the present time, and the remaining track number recognition means for recognizing the remaining track number up to the cutting end side zone boundary are provided. 5. An optical disk master making device, characterized in that correction function storage means for storing a numerical value that gradually decreases or increases by an arbitrary function using the numerical value obtained by the track number recognizing means is added to the deflection signal generating means. 4. A laser light source, a rotating mechanism for rotating at a predetermined speed a disc-shaped cutting master having a surface coated with a photosensitizer which reacts to the wavelength of a laser beam emitted from the laser light source, and the photosensitive master for the cutting master. An objective lens for converging a laser beam emitted from the laser light source into a spot on a surface, a feeding mechanism for moving the converged laser spot in a radial direction of the cutting master at a predetermined speed, and a pre-groove for guiding a track. Of the signal and the physical address information (PID) pre-pit signal in a predetermined format, a modulation signal generating means for controlling the output signal of the modulation signal generating means as a control input, and a radius of the cutting master for the laser spot. Predetermined time information, direction information and size information Forming an optical disk master having a deflection signal generating means having a format generating means and a means for correcting displacement of a physical address information (PID) pit position, and an optical deflecting means having an output signal of the deflection signal generating means as a control input. In the device, a zone counter for counting the number of elapsed zones from the cutting start point to the present time, zone coefficient storage means for storing an arbitrary function using the numerical value of the zone counter, and a division circuit for using the zone coefficient correction means as a divisor. An optical disc master making device characterized in that the optical disc master is added to the deflection signal generating means. 5. The optical disk master creation device according to claim 3 or 4, further comprising means for arbitrarily updating the stored contents of the correction function storage means and the zone coefficient storage means. Characteristic optical disc master making device. 6. A disk-shaped cutting master having a surface coated with a photosensitizer that reacts to the wavelength of a laser beam emitted from the laser light source is rotated at a predetermined speed, and the laser beam is emitted from the laser light source onto the photosensitive surface of the cutting master. The laser beam is focused into a spot shape, the focused laser spot is moved in the radial direction of the cutting master at a predetermined speed, and a track guiding pre-groove signal and physical address information (PID) are provided on the cutting master. In a method for producing an optical disc master for forming a pre-pit signal, pre-pits of physical address information (PID) are preliminarily deviated in the outer peripheral direction in a track approximately inward of the zone, and the zone adjacent to the inner peripheral side of the track is arranged. Angle direction of pre-pits for physical address information (PID) The pregroove being formed is displaced and deformed in the outer peripheral direction, and the prepits of the physical address information (PID) are preliminarily displaced in the inner peripheral direction in the track near the outer periphery of the zone, and at the same time, Fabrication of a master for an optical disk characterized by predicting the range of the physical address information (PID) prepits arranged in the adjacent zone on the outer circumference side in the direction of the rotation angle and causing the pregroove being formed to be displaced inward in the inner circumference direction. Method. 7. An optical disc master on which a track guiding pregroove signal and a physical address information (PID) prepit signal are formed, and a disc alone when a predetermined radial direction position of the physical address information (PID) prepit is used as a reference. Pre-pits are formed at the positions opposite to the physical address information (PID) pit position displacement direction predicted after completion, and the pre-grooves are deformed in the direction opposite to the pre-groove distortion direction predicted after completion of the disk unit. A master for an optical disc, which is characterized by: 8. An optical disk substrate manufactured by using the optical disk master prepared by the optical disk master creating apparatus according to claim 1. Description: 9. An optical disk substrate manufactured by using the optical disk master prepared by the method for manufacturing an optical disk master according to claim 6. 10. An optical disk substrate manufactured using the optical disk master according to claim 7. 11. An optical disc comprising a recording film formed on the optical disc substrate according to any one of claims 8 to 10. 12. An optical disc, wherein the optical disc according to claim 11 has a laminated structure. 13. The optical disk according to claim 11 or 12, wherein a protective layer is provided on the recording layer of the substrate, and a recording / reproducing laser spot is irradiated from the protective layer side. An optical disc characterized by.