JPH1116166A - Data recording method, device therefor, transmission medium and data recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable recording with higher density in an RPR(radial partial response) disk. SOLUTION: Data generated by an information source 1 are recorded on a glass original disk 5 and an RPR disk 7 is prepared based on the data. The prepared RPR disk 7 is actually reproduced and at first a co-channel interference is calculated in a record compensating amount calculator 9. At this time, the data from which the influence of disk defects is removed are used. The data being used taken the influence of at least two adjacent edges and of at least two adjacent edges on the adjacent tracks into consideration. A pre- emphasis compensating amount corresponding to the calculated co-channel interference is calculated and the calculated result is stored in a ROM 10. The data of the compensating amount recorded in the ROM 10 are recorded on a compensating amount table present in a record compensating circuit 3. The record compensating circuit 3 processes the recorded data from the information source 1 corresponding to the calculated compensating amount and performs a cutting operation again.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data recording method and a data recording apparatus, a transmission medium, and a data storage medium, and more particularly, to a method for correcting an edge position of a pit on an RPR disk, for example, by writing data on an optical disk. Data recording method and data recording apparatus, transmission medium,
And a data storage medium.

[0002]

2. Description of the Related Art The present applicant has determined the position of the edge of a pit by
Recording data by changing it stepwise according to the information to be recorded is described in, for example,
No. 1724 (hereinafter, this method is referred to as SCIPER (trademark) method). According to this proposal, the pit edge position basically corresponds to any one of eight macro steps 0 to 7 (the step width is, for example, 0.04 μm) corresponding to the recording data. However, the position of this edge is further corrected (pre-emphasis) to any of 256 microsteps having a fine change width in order to reduce the influence of intersymbol interference and crosstalk. . By correcting the edge position, the width of change of the edge can be reduced, and higher density recording can be performed.

The above-described correction of the pit edge position is performed as follows. First, a disc on which information is recorded is produced, the produced disc is reproduced, and intersymbol interference is measured. Then, a correction value corresponding to the measured inter-symbol interference is calculated by a predetermined process and stored in a predetermined storage device. Then, the information is stored again on the disk. At this time, the position of the edge is changed in accordance with the previously calculated correction value. The process of correcting (pre-emphasis) the position of the edge of the pit is repeated until the intersymbol interference becomes equal to or less than a predetermined reference value.

[0004] The present applicant has also proposed a RPR (Radial Partial Respo) using a partial response in a radial direction.
nse) The position of the rising (leading) edge or falling (trailing) edge of the pit is changed stepwise in units of the first width in accordance with information recorded as pits on adjacent tracks as a disk. Thus, a method of recording information was proposed earlier (Japanese Patent Application No. 8-195606). According to this method,
Since the reproduction is performed such that the reproduction beam spot passes through the central portion between two adjacent tracks, information can be recorded at a higher density.

[0005]

In an RPR disc, data is recorded on one track at a time, but data is reproduced on two tracks at the same time. That is, in the case of the RPR disc, the recording system and the reproduction system do not have the same track king, and it is necessary to obtain the pre-emphasis amount of the data of one track from the reproduction data when two tracks are read simultaneously. However, the method of obtaining the pre-emphasis amount of the SCIPER method described above cannot be used for an RPR disc because it is premised that the tracking of the recording system matches the tracking of the reproduction system.

The present invention has been made in view of such a situation, and it is possible to calculate a correction amount for reducing the influence of intersymbol interference and crosstalk on recording on an RPR disk. This enables data to be recorded at a higher density.

[0007]

According to a first aspect of the present invention, there is provided a data recording method comprising: a first changing step of changing a position of an edge of a pit stepwise with a first width corresponding to data to be recorded; , The edge position defined by the first change step is set to the first track where the pit exists,
When the reproduction beam spot passes through the edge of the pit existing on the second track adjacent to the second track at the same time, the position where the intersymbol interference caused by other edge positions is minimized is smaller than the first width. And a second changing step of changing the width in a stepwise manner with the second width.

[0010] In the data recording apparatus according to the present invention, the position of the edge of the pit may be set in the first position corresponding to the data to be recorded.
First changing means for changing stepwise in a width of
When the reproduction beam spot passes through the edge position defined by the change means at the same time at the edge of the pit present in the first track where the pit exists and the second track adjacent to the first track, At a position where intersymbol interference caused by another edge position is minimized, a second changing means for changing the width in a stepwise manner with a second width smaller than the first width is provided.

According to a twelfth aspect of the present invention, in the transmission medium, the position of the edge of the pit is changed stepwise with a first width corresponding to the data to be recorded, and the first change step. When the reproduction beam spot passes through the defined edge position at the same time as the edge of the pit existing in the first track where the pit is present and the second track adjacent to the first track, the other edge position is determined. And a second changing step of changing stepwise with a second width smaller than the first width to a position where the intersymbol interference caused by the above is minimized.

According to the data recording medium of the present invention, the position of the edge of the pit is determined by the first position corresponding to the data to be recorded.
And the edge position defined by the first width is shifted to the first track where the pit is present and the edge of the pit present in the second track adjacent to the first track. When the reproduction beam spot passes at the same time, data is recorded by changing stepwise with a second width smaller than the first width to a position where intersymbol interference caused by another edge position is minimized. It is characterized by having.

In the data recording method according to the first aspect, the data recording apparatus according to the eleventh aspect, and the transmission medium according to the twelfth aspect, the position of the edge of the pit is recorded in correspondence with the data to be recorded. The read beam spot passes through the step defined by the first width at the same time as the edge of the pit existing on the track on which the pit exists and on the track existing on the adjacent track. In this case, the position is changed stepwise to a position where the intersymbol interference caused by another edge position is minimized with a second width smaller than the first width.

In the data recording medium according to the present invention, the position of the edge of the pit is changed stepwise with a first width corresponding to the data to be recorded,
The edge position defined by the width of
When the reproduction beam spot simultaneously passes through the edge of the pit existing in the second track adjacent to the first track and the first track, at the position where the intersymbol interference due to the other edge position is minimized, Data is recorded by changing the width stepwise at a second width smaller than the first width.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below. In order to clarify the correspondence between each means of the invention described in the claims and the following embodiments, each means is described. When the features of the present invention are described by adding the corresponding embodiment (however, an example) in parentheses after the parentheses, the result is as follows. However, of course, this description does not mean that each means is limited to those described.

[0014] In the data recording apparatus according to the present invention, the position of the edge of the pit may be determined by the first position corresponding to the data to be recorded.
A first changing means (for example, the edge position tables 32 and 34 in FIG. 3) for changing the edge position defined by the first changing means in a first track having a pit, When the reproduction beam spot passes through the edge of the pit existing on the second track adjacent to the first track at the same time, the first point is located at the position where the intersymbol interference caused by the other edge position is minimized. A second changing means (for example, a read correction value table in FIG. 3) for changing the width stepwise with a second width smaller than the width is provided.

FIG. 1 shows a configuration example of a data recording apparatus according to the present invention. The recording signal generator 2 digitizes the signal from the information source 1 and outputs it to the recording correction circuit 3. The recording correction circuit 3 reads the input signal and the ROM (Read On
ly Memory) 10 synthesizes a recording correction amount corresponding to the input signal stored in the memory 10 and outputs it to the cutting machine 4. AOM (Acoustic) in cutting machine 4
The optical modulator 15 controls the pickup 16 based on the input signal, and cuts the glass master 5 coated with the resist.

The cut glass master 5 is subjected to exposure, development, plating, and the like in a mastering device 6 and then to a master master and a stamper.
Is formed.

The formed RPR disk 7 is reproduced by a reproducing device 8. A reproduction signal from the pickup 20 in the reproduction device 8 is output to the recording correction amount calculator 9. The recording correction amount calculator 9 calculates the intersymbol interference of the edge based on the input reproduction signal, calculates a correction amount for reducing the intersymbol interference, and stores the calculated correction amount in the ROM 10. It is recorded. Note that instead of the ROM 10, a recording medium such as a RAM (Random Access Memory) may be used.

Next, the operation will be described. The information source 1 generates an audio signal or the like as a signal to be recorded and supplies it to a recording signal generator 2. Recording signal generator 2
Digitizes and modulates the supplied information recording signal and supplies it to the recording correction circuit 3. Recording correction circuit 3
Reads the recording correction amount corresponding to the digitally modulated information recording signal from the ROM 10 and corrects the information recording signal using the recording correction amount.
Output to OM15. In the initial state, the ROM
Nothing is recorded in 10.

The AOM 15 controls the pickup 16 in response to a signal from the recording correction circuit 3, and cuts the glass master 5 on which the resist has been applied. In the mastering device 6, the cut glass master 5 is
First, exposure, development, and plating are performed, and a master master is manufactured. A stamper was made from the master master, and 2P (Photo Polymariz) was created from the stamper.
ation) method to produce a reproducible RPR disc 7.

The produced RPR disk 7 is reproduced by a reproducing device 8. The reproduced signal is supplied to a recording correction amount calculator 9. Based on the supplied reproduction signal, the recording correction amount calculator 9 calculates the intersymbol interference of the pit edge of the predetermined track. The intersymbol interference is defined by two adjacent edges before and after the edge, and an edge at an adjacent position on another track adjacent to the track, and the recorded information of the two edges before and after the edge. Based on the calculated intersymbol interference, the edge correction amount for minimizing the intersymbol interference is calculated and recorded in the ROM 10. The calculation of the correction amount is performed for all combinations of edges that define the correction amount, and the entire result is recorded in the ROM 10.

As shown in FIG. 2, the RPR disk has a C
Cutting is performed by the AV (Constant Angular Velocity) rotation method, and pits are arranged in the same phase in the radial direction. Now, the edge Bn of the pit on the track of the number n
The calculation of the intersymbol interference with respect to is described below. This intersymbol interference is caused by the edge A adjacent before and after the edge Bn.
n, Cn, and edges An-1, Bn-1, C on track n-1 adjacent to track n with edge Bn
It is calculated corresponding to the (n-1) recording information. This edge B
A correction amount for minimizing intersymbol interference in n is further calculated and stored in the ROM 10. In FIG. 2, the edge position of each pit of the RPR disc can be changed to any one of four steps.

After all the correction amounts are stored in the ROM 10, a new RPR disk 7 is obtained by the same processing again. Then, a new correction amount is obtained from the RPR disk 7. This series of steps is repeatedly performed until the intersymbol interference becomes equal to or less than a preset reference value.

FIG. 3 is a diagram showing a detailed configuration of the recording correction circuit 3. As shown in FIG. The signals from the recording signal generator 2 are sequentially supplied to delay circuits 30-1 to 30-6 via a first-in first-out (FIFO) 31. The outputs of the delay circuits 30-1 to 30-3 are supplied to a read correction value table 33 and a trail correction value table 35. The outputs of the delay circuits 30-4 to 30-6 are supplied to a read correction value table 33 and a trail correction value table 35. The output from the delay circuit 30-2 is supplied to the edge position tables 32 and 34.

The output from the read correction value table 33 is supplied to an adder 40 after the signal fed back by the FIFO 37 is subtracted by a subtractor 36.
The adder 40 adds the signal from the edge position table 32 to the supplied signal, and performs D / A (Digital / Analogue).
It is supplied to a converter 42.

The output from the trail correction value table 35 is supplied to the adder 41 after the signal fed back by the FIFO 39 is subtracted by the subtractor 38.
The adder 41 adds the signal from the edge position table 34 to the supplied signal and supplies the signal to the D / A converter 43.

Each output from the D / A converters 42 and 43 is supplied to a signal generation circuit 44. Signal generation circuit 44
Is supplied to the cutting machine 4.

The reproducing apparatus for an RPR disk has a reproducing beam spot passing through the center of two tracks. The state of this reproduction beam spot was shown
FIG. In the following, an example of recording correction of the trailing edge Bn of the pit in FIG.
The operation of the circuit will be described. In FIG. 4, A, B, and C are symbols for identifying edges of each pit, and X, Y, and Z indicate edge positions.
n-1 indicates a track number. Further, the position of the edge changes to four steps of 0, 1, 2, 3 in FIG.
Have been made to take one.

As shown in FIG. 4, since the reproducing beam spot is made to pass exactly between the two tracks, the inter-code interference of the edge Bn can be determined by using both the edges Bn and Bn-1. RF when playing edges simultaneously
It is necessary to calculate the intersymbol interference for the RF signal of only the edge Bn from the intersymbol interference of the signal. Edge B
In order to determine the amount of intersymbol interference between n and Bn-1, the intersymbol interference from adjacent edges An, An-1, Cn, and Cn-1 must be considered.

The above-mentioned intersymbol interference differs depending on the combination of the positions of the edges An and An-1, Bn and Bn-1, and Cn and Cn-1. The intersymbol interference is calculated every time. The reason will be described below.

In the RPR disk, the reproducing beam spot is controlled so as to pass right through the center of two tracks. Therefore, when the edge An is at the edge position X1,
When the edge An-1 is at the edge position X0, and when the edge An is at the edge position X0 and the edge An-1 is at the edge position X1, the RF signal when the reproduction beam spot is applied to both edges is the track Are symmetrical with respect to the edge position, and both are signals for the edge X0 + X1, so that there is no distinction between the two RF signals. Therefore, in the case of a combination of edge positions symmetrical with respect to the center of two tracks, the magnitude of intersymbol interference is the same in principle.

However, in practice, since external vibrations and the like are applied to the reproducing apparatus, it is difficult to control the reproducing beam spot so as to always pass the center of the two tracks at all times. In such a case,
The edge An is at the edge position X1, the edge An-1 is at the edge position X0, and the edge An is at the edge position X0.
And RF when edge An-1 is at edge position X1
The signals will be equal. Therefore, it is necessary to calculate the intersymbol interference for each combination of edges.

The data supplied to the delay circuits 30-1 to 30-3 are sequentially delayed, so that the delay circuit 30-1
Outputs the data at the edge position Xn of the edge An, the delay circuit 30-2 outputs the data at the edge position Yn of the edge Bn, and the delay circuit 30-3 outputs the data at the edge Cn.
The data of the edge position Zn of n is output. Each delay circuit 3
Outputs of 0-1 to 30-3 are supplied to a read correction value table 33 and a trail correction value table 35, respectively. Therefore, data corresponding to three consecutive edges of two consecutive pits is input to each table. The output from the delay circuit 30-2 is supplied to the edge position tables 32 and 34.

Further, outputs from the delay circuits 30-4 to 30-6 are also input to the read correction value table 33 and the trail correction value table 35. The FIFO 31 delays the data from the delay circuit 30-3 by exactly one track, and supplies the data at the edge position of the track n-1 to the delay circuit 30-4. Then, the supplied data is sequentially supplied to the delay circuits 30-4 to 30-6, and the respective outputs become edge positions Xn-1, Yn-1, and Zn-1, and the delay circuits 30-1 to 30- Just one of the output from 3
It becomes the data of the edge position before the track.

Each of the delay circuits 30-1 to 30-6
May be replaced by a flip-flop circuit.

The edges An, An obtained as described above
The six edge position information of -1, Bn, Bn1-1, Cn, and Cn-1 are input to the read correction value table 33 and the trail correction value table 35 as reference addresses.

Next, the preparation of the correction value tables recorded in the read correction value table 33 and the trail correction value table 35 will be described with reference to the flowchart of FIG. Each process of the flowchart of FIG. 5 is performed by the recording correction amount calculator 9. The values calculated by the respective processes are temporarily stored in the ROM 10, and are stored in the read correction value table 33 and the trail correction value table 35 as necessary.

First, in step S11, edge A
n, An-1, Bn, Bn-1, Cn, and Cn-1
Are located at Xn, Xn-1, Yn, Yn-
Edges Bn and B such as 1, Zn, and Zn-1
The data of the level value of the RF signal when the reproduction spot is simultaneously applied to n-1 is obtained by reproducing the RPR disk on which the learning data is recorded. Note that a plurality of all combinations of edge positions are stored as learning data.

FIG. 6 shows a frequency distribution diagram drawn based on the data thus obtained. As can be seen from FIG. 6, the level of the RF signal when the reproduction beam spot is simultaneously applied to the edges Bn and Bn-1 is based on the theoretical value including no noise, the electric noise, the pickup noise, the media noise, and the crosstalk. Due to various kinds of random noise such as, for example, they are distributed with a spread. Further, an RF reproduction level value greatly deviated due to a disk defect has been observed.

Next, in step S12, an average value (AVG) and a standard deviation value (δ) are calculated from the obtained data. First, the total number of data (total number of frequencies) in the frequency distribution diagram of FIG. 6 is N, and the class of each frequency is Dn, and an average value is obtained by the following equation. AVG = ΣDn / N (1)

However, using the data of FIG. 6 as it is,
By calculation, the original (theoretical value) reproduction R due to the defect is calculated.
Since the calculation includes the value that greatly deviates from the F-level value, the value is greatly shifted from the average value when there is no defect. This is shown in FIG. AVG1
Indicates the average value when there is no defect.
G2 indicates an average value when there is a defect.
If there is a difference in the average value between the case where there is a defect and the case where there is no defect, the difference also appears in the intersymbol interference calculated using this average value.

Therefore, when the average value calculated while including the defect is used, a correct edge correction amount cannot be obtained, so that not only the effect of intersymbol interference cannot be reduced or eliminated, but also the adverse effect can be obtained. May also result. Further, the convergence of the recording correction amount may be delayed, and the number of times of repeating the pre-emphasis process may increase. Therefore, in order to obtain the average value of the reproduction RF level values, it is preferable to use a frequency distribution diagram from which defects have been removed. For this purpose, the standard deviation value (δ) is obtained by the following equation. δ = [Σ (Dn-AVG) ² ] ^(1/2) / N (2)

Next, in step S13, step S
The data of AVG ± 3δ is removed from the data obtained in step 11 to obtain a frequency distribution chart as shown in FIG. FIG. 8 shows a frequency distribution diagram of the RF signal from which the influence of the defect has been removed. In step S14, a new average value (AVG ') is calculated from the following equation based on the frequency distribution chart. In the following equation, N ′ indicates the total number of data in FIG.
n ′ indicates the class of each frequency. AVG '= ΣDn' / N '(3)

In step S15, using the average value (AVG ') from which the defect has been removed, the edges Bn and B
The intersymbol interference amount for n-1 is obtained as follows.
That is, the average value (AV
G ′) are adjacent edges An, An−1, Cn, and C
n−1, the edge B is assumed to be free from the influence of the intersymbol interference.
The value is different from the reproduction RF level value (IDL) when the reproduction beam spot is simultaneously applied to n and Bn-1. Therefore, the intersymbol interference e (Xn, Yn, Zn, Xn-1, Yn-1, Zn-n) from the adjacent edges An, An-1, Cn, and Cn-1 with respect to the edges Bn and Bn-1.
1) is obtained by the following equation. IDL-AVG'≡e (Xn, Yn, Zn, Xn-1, Yn-1, Zn-1) (4)

The intersymbol interference amount e (Xn, Yn,
Zn, Xn-1, Yn-1, Zn-1) are An, B
The read correction value table 3 uses the edge positions Xn, Yn, Zn, Xn-1, Yn-1, and Zn-1 of n, Cn, An-1, Bn-1, and Cn-1 as addresses.
3 and stored in the trail correction value table 35.

Since the read correction value table 33 and the trail correction value table 35 store the inter-code interference for the edges Bn and Bn-1, as described above, the read correction value table 33 Alternatively, to calculate the correction amount for the edge Bn from the output of the trail correction value table 35, further calculation is required. Therefore, the correction amount C (Yn) for the edge Bn is obtained from the recurrence formula with the intersymbol interference. In the following equation, C (Yn
-1) is a correction amount for the edge Bn-1. C (Yn) = e (Xn, Yn, Zn, Xn-1, Yn-1, Zn-1) -C (Yn-1) (5)

A circuit for calculating the above equation is extracted from FIG.
As shown in FIG. The correction amount C (Yn-1) for the edge Bn-1 on the track n-1 on the inner side of one track is delayed by exactly one track in the FIFO 39 in the FIFO 39. You can ask. Therefore, the output from the trail correction value table 35 is subtracted by the subtractor 38 from C (Yn-1) fed back from the FIFO 39, and C (Yn)
Is input to the adder 41.

When the correction amount C (Yn) for the edge Bn is determined as described above, the correction amount C (Yn-) for the edge Bn-1 is added to the correction amount C (Yn) for the edge Bn.
The following equation is obtained by adding 1).

C (Yn) + C (Yn−1) = e (Xn, Yn, Zn, Xn−1, Yn−1, Zn−1) (6)

That is, when the reproduction beam spot is simultaneously applied to the edge Bn and the edge Bn-1, the correction amounts are the edges AN, Bn, Cn, AN-1, Bn-1, and C
n-1 edge positions (Xn, Yn, Zn, Xn-
(1, Yn-1, Zn-1) as an address, an intersymbol interference amount e (Xn, Yn, Zn, Xn-1, Yn-1, Zn-).
1). Therefore, the following results are obtained using equations (4) to (6).

AVG ′ + e (Xn, Yn, Zn, Xn−1, Yn−1, Zn−1) = IDL (7) From this equation, the reproduced RF level value of the pit edge after correction is represented by the code It can be set to a value close to the reproduction RF level value IDL when the reproduction beam spot is simultaneously applied to the edges Bn and Bn-1 when there is no influence of the interfering.

The initial value C (Y0) of C (Yn) is
Set to zero. Therefore, since the position of the pit edge in the first track is not correctly corrected, the pit in the first track is a dummy pit that does not correspond to information.

The correction value C (Yn) in the above processing is
It is assumed that six edge positions of edges An, Bn, Cn, An-1, Bn-1, and Cn-1 are fixed. However, in the pre-emphasis process, these edges are also corrected, and the edge positions move, so that they are not fixed. Therefore, if the calculated recording correction amount is fed back as it is, pre-emphasis may not be performed properly. Therefore, a value multiplied by a gain K of 1 or less is fed back (the correction amount is set to a value smaller than a value that sufficiently suppresses intersymbol interference). Taking this into consideration, the circuit configuration of FIG. 9 can be changed to the circuit configuration of FIG. The correction amount C (Yn) of the edge Bn obtained by this circuit is obtained by the following equation. C (Yn) = K [e (Xn, Yn, Zn, Xn-1, Yn-1, Zn-1) -C (Yn-1)] (8)

The configuration shown in FIG. 9 is based on an IIR (Infinite
The configuration is the same as that of the Impulse Response filter, and the correction value C (Yn) tends to diverge. That is, C (Yn)
+ C (Yn-1) is a converged value, but individual C (Yn-1)
n) and C (Yn-1) have very large values. However, with the configuration as shown in FIG.
(Yn) and C (Yn-1) are converged values,
C (Yn) + C (Yn-1) also becomes a converged value.

The correction amount C (Yn) (second width) of the edge Bn obtained as described above is recorded in the unit recording of the edge (FIG. 2).
And the current edge Bn is shifted (corrected) by this amount, which is shorter than the interval (first width) between the edge positions 0, 1, 2, and 3 shown in FIG. FIG. 11 shows a circuit for calculating data for shifting the edge, which is extracted from FIG. The edge position table 34 receives digital position data Yn to be recorded on the edge Bn from the delay circuit 30-2. The edge position table 34 is
The input digital position data Yn is converted into corresponding specific edge position information Yn ′. The adder 41 adds a correction amount C (Yn) to the edge position information Yn ′. Thus, the edge position data Yn of the edge Bn is corrected. The corrected edge position information Yn 'is supplied to the D / A converter 43 and D / A converted. The data from the D / A converter 43 is supplied to a signal generation circuit 44, converted into a pit edge recording signal, and supplied to the cutting machine 4.

Note that the FIFOs 31, 37 and 39 are SRAM (Stat
ic RAM).

In the above, the case where the trailing edge is formed has been described. However, when the leading edge is formed, the edge position table 32, the read correction value table 33, the subtractor 36, the FIFO 37, and the adder 4 are used.
0, a similar process is performed by the D / A converter 42.

By performing pre-emphasis as described above, an RPR disk with reduced intersymbol interference can be obtained.

In this specification, pits include not only pits as physical irregularities but also marks formed by phase change, magnetic domains, and the like.

[0059]

As described above, the data recording method according to the first aspect, the data recording apparatus according to the eleventh aspect, and the twelfth aspect.
According to the transmission medium described in (1) and the data recording medium described in (13), the position of the edge of the pit is at least two adjacent positions before and after, and at least two adjacent positions on the track adjacent to the edge. Since the correction is performed in consideration of the position of the edge, the pre-emphasis can be correctly performed even on the RPR disk.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an embodiment of a data recording device of the present invention.

FIG. 2 is a diagram showing an arrangement of pits on an RPR disc.

FIG. 3 is a block diagram illustrating an internal configuration of the recording correction circuit of FIG. 1;

FIG. 4 is a diagram for explaining a state of a reproduction beam spot on an RPR disc.

FIG. 5 is a flowchart illustrating a process of creating a correction value table.

FIG. 6 is a diagram illustrating a frequency distribution of RF signal level values when a reproduction beam spot is simultaneously applied to an edge Bn and an edge Bn-1.

FIG. 7 is a diagram for explaining a difference between average values when there is a defect and when there is no defect;

FIG. 8 is a diagram illustrating a frequency distribution of RF signal level values when the RF signal level value of a defect portion is removed.

FIG. 9 is a diagram extracted from a circuit configuration for obtaining a correction value in FIG. 3;

FIG. 10 is a diagram illustrating another example of the circuit configuration for obtaining the correction value in FIG. 9;

11 is a diagram extracted from a circuit configuration for shifting an edge in FIG. 3 according to a correction amount.

[Explanation of symbols]

1 information source, 2 recording signal generator, 3 recording correction circuit, 4 cutting machine, 5 glass master,
6 Mastering device, 7 RPR disk, 8
Playback device, 9 recording correction amount calculator, 10 RO
M, 15 AOM, 16, 20 pickup,
30-1 to 30-2 delay circuit, 31, 37, 39
FIFO, 32, 34 edge position table (first changing means), 33 read correction value table (second changing means), 34 trail correction value table (second changing means), 36, 38 subtractor, 40, 41 adder, 42, 43 D / A converter, 44 signal generation circuit

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[Procedure amendment]

[Submission date] September 5, 1997

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claim 5

[Correction method] Change

[Correction contents]

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0003

[Correction method] Change

[Correction contents]

The above-described correction of the pit edge position is performed as follows. First, a disc on which information is recorded is manufactured , and the manufactured disc is reproduced, and intersymbol interference is measured. Then, a correction value corresponding to the measured inter-symbol interference is calculated by a predetermined process and stored in a predetermined storage device. Then, the information is stored again on the disk. At this time, the position of the edge is changed in accordance with the previously calculated correction value. The process of correcting (pre-emphasis) the position of the edge of the pit is repeated until the intersymbol interference becomes equal to or less than a predetermined reference value.

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0011

[Correction method] Change

[Correction contents]

[0011] In the data recording method according to the first aspect , the data recording apparatus according to the eleventh aspect, and the transmission medium according to the twelfth aspect, the first pit corresponding to the data for recording the position of the edge of the pit may be used. , And the position of the edge defined by the first width is changed to a track where the pit exists and a pit which exists in the adjacent track.
When the reproduction beam spot simultaneously passes through the edge of, the step width is changed to a position where the intersymbol interference caused by other edge positions is minimized with a second width smaller than the first width.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0031

[Correction method] Change

[Correction contents]

However, in practice, since external vibrations and the like are applied to the reproducing apparatus, it is difficult to control the reproducing beam spot so as to always pass the center of the two tracks at all times. In such a case,
The edge An is at the edge position X1, the edge An-1 is at the edge position X0, and the edge An is at the edge position X0.
And RF when edge An-1 is at edge position X1
Signal is not equal. Therefore, for each combination of edges,
Intersymbol interference must be calculated.

[Procedure amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0032

[Correction method] Change

[Correction contents]

The data supplied to the delay circuits 30-1 to 30-3 are sequentially delayed, so that the delay circuit 30-1
But when the output of the data of the edge position Z n of the edge C n, the delay circuit 30-2 outputs the data of the edge position Yn edge Bn, the delay circuit 30-3, the edge A
and it outputs the data of n in the edge position X n. Each delay circuit 3
Outputs of 0-1 to 30-3 are supplied to a read correction value table 33 and a trail correction value table 35, respectively. Therefore, data corresponding to three consecutive edges of two consecutive pits is input to each table. The output from the delay circuit 30-2 is supplied to the edge position tables 32 and 34.

[Procedure amendment 6]

[Document name to be amended] Statement

[Correction target item name] 0033

[Correction method] Change

[Correction contents]

Further, outputs from the delay circuits 30-4 to 30-6 are also input to the read correction value table 33 and the trail correction value table 35. The FIFO 31 delays the data from the delay circuit 30-3 by exactly one track, and supplies the data at the edge position of the track n-1 to the delay circuit 30-4. The supplied data are sequentially supplied to the delay circuit 30-4 through 30-6, each output edge position Z n-1, Yn-1 , X n-1 , and the delay circuits 30-1 to Just one of the output from 30-3
It becomes the data of the edge position before the track.

[Procedure amendment 7]

[Document name to be amended] Statement

[Correction target item name] 0036

[Correction method] Change

[Correction contents]

Next, the creation of the correction value tables recorded in the read correction value table 33 and the trail correction value table 35 will be described with reference to the flowchart of FIG. Each process of the flowchart of FIG. 5 is performed by the recording correction amount calculator 9. The values calculated by the respective processes are temporarily stored in the ROM 10, and are stored in the read correction value table 33 and the trail correction value table 35 as necessary.

[Procedure amendment 8]

[Document name to be amended] Statement

[Correction target item name] 0051

[Correction method] Change

[Correction contents]

The initial value C (Y0) of C (Yn) is
Set to zero. Therefore, the pit on the first track
No correction is made for the position of the edge.

[Procedure amendment 9]

[Document name to be amended] Drawing

[Correction target item name] Figure 3

[Correction method] Change

[Correction contents]

FIG. 3

Claims (13)

[Claims] A first changing step of changing a position of an edge of a pit stepwise with a first width corresponding to data to be recorded; and an edge position defined by the first changing step. When the reproduction beam spot simultaneously passes through the edges of the pits present in the first track where the pits are present and the second track adjacent to the first track, the code between the codes caused by the other edge positions A second changing step of changing in a step-like manner with a second width smaller than the first width at a position where the interference is minimized. 2. A change in the position of the edge having the second width is at least two adjacent positions before and after the first track.
2. The data recording method according to claim 1, wherein the recording is performed in consideration of a position of one edge and a position of two adjacent edges on the second track. 3. A recording step of recording a pit having an edge at a position changed in the first and second changing steps on a recording medium, and reproducing the data recorded on the recording medium from the recording medium. A first calculating step of calculating intersymbol interference of the data reproduced in the reproducing step; and a second calculating step of calculating a correction amount of a second width of the edge for reducing the intersymbol interference. 2. The data recording method according to claim 1, further comprising: in the recording step, using the correction amount calculated in the second calculation step, the data is further recorded on a recording medium. . 4. The data recording method according to claim 3, wherein the correction amount of the first track is calculated based on the correction amount of the second track. 5. The data recording method according to claim 4, wherein a dummy pit is recorded on the second track for calculating the correction amount of the first track. 6. The data recording method according to claim 4, wherein the calculation of the correction amount is performed by a recurrence formula. 7. The processing from the recording step to the second calculation step until the calculated intersymbol interference amount of the data reproduced in the reproduction step becomes smaller than a predetermined reference value set in advance. 4. The data recording method according to claim 3, wherein the method is repeated. 8. The data recording method according to claim 3, wherein at least the first correction amount is set to a value smaller than the calculated value that sufficiently suppresses intersymbol interference. 9. In the recording step, in a first time, learning data defining all combination patterns of pit edge positions of the first track and the second track is recorded on the recording medium. 4. The data recording method according to claim 3, wherein: 10. The calculation of the intersymbol interference is performed a plurality of times for one combination pattern, unnecessary data is removed from the obtained data, and an average value of the removed data is calculated as the intersymbol interference. The data recording method according to claim 9, wherein the data recording method is used as a value. 11. A first method for changing the position of an edge of a pit in a stepwise manner with a first width corresponding to data to be recorded.
Changing the edge position defined by the first changing means to an edge of a pit present in a first track where the pit exists and a pit existing in a second track adjacent to the first track; A second changing means for changing to a position where intersymbol interference caused by another edge position is minimized in a stepwise manner with a second width smaller than the first width when a reproduction beam spot passes at the same time; A data recording device comprising: 12. A first method for changing the position of the edge of a pit in a stepwise manner with a first width corresponding to data to be recorded.
Changing the edge position defined in the first changing step to an edge of a pit present in the first track where the pit exists and a second track adjacent to the first track; A second changing step of changing the step width at a second width smaller than the first width to a position where the intersymbol interference caused by another edge position becomes minimum when the reproduction beam spot passes at the same time; A transmission medium for transmitting a computer program comprising: 13. The position of an edge of a pit is changed stepwise with a first width corresponding to data to be recorded, and the edge position defined by the first width is changed to a position of the pit where the pit exists. 1 and the edge of a pit present in a second track adjacent to the first track,
At the same time, when the reproducing beam spot passes, data is recorded by changing the step width with a second width smaller than the first width to a position where the intersymbol interference caused by another edge position is minimized. A data recording medium characterized by the following.