JPH08102070A - Data recording method and reproducing method for optical disk - Google Patents

Abstract

PURPOSE: To obtain a data recording method for optical disks capable of easily executing control at the time of recording and a data reproducing method for optical disks with which high S/N is obtainable by suppressing the noise of a low frequency region. CONSTITUTION: A difference between the n-th data (n is an integer) and the (n-1)th data in binary recording data (a) to be recorded is obtd. and conversion data (b) consisting of 1, 0, -1 is formed. The data is recorded on the optical disk by the three recording states; the large recording mark 1, small recording mark 2 and blank 3 consisting of the three states; 1, 0, -1 of the conversion data. The level (e) of the reproduced waveforms, the first slice level 4 and the second slice level 5 are compared in synchronization with the clock (f) and the recording state of the optical disk is discriminated to the reproduced signal (g) of any one of 1, 0, -1 at the time of reproduction. The (n-1)th reproduced data is added to the n-th reproduced signal in the discriminated reproduced signal and the n-th reproduced data (h) is formed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disk data recording method and reproducing method.

[0002]

2. Description of the Related Art Conventionally, in data recording on an optical disk, "A study of high-speed recording rate / high-density recording method for phase-change disk", Technical Report of Television Society (ITE Te
chnical Report Vol.17 No.97 pp.7-12 VIR'93-83 (DEC '
93)), etc., edge recording is performed as a method of high density recording. This is a method in which the pit position recording that used only circular pits in the past can be recorded at high density by changing the length of the mark. Figure 2
Shows the actual data, the recording signal, and the shape of the mark to be formed. Here, as recording data, 8T, 8T, 8T, 2
T, 8T and 8T are recorded. Even if the recording data is the same, it may be different depending on the state of the previous bit, and FIGS. 2A and 2B show two kinds of cases in which a mark is formed. When recording 2T as recording data,
non-return-to-zero (inverted) recording (NRZI)
The data in the form of is used as a recording signal as it is. On the other hand, when recording 8T, the pulse train is used and the pulse widths of the foremost part and the last part are changed, not the data in the form of NRZI.

[0003]

However, as described above, in the conventional data recording method for the optical disc, the length of the recording marks and the length of the space between the recording marks are changed. The control is complicated and it is necessary to reproduce up to the DC level, and the storage capacity of the optical disk cannot be increased.

In view of the above problems, an object of the present invention is to provide an optical disk data recording method capable of easily controlling recording and an optical disk data reproducing method capable of suppressing high frequency noise and obtaining high S / N. To do.

[0005]

In order to achieve the above object, the present invention provides a method for recording data on an optical disk according to claim 1, wherein the binary data to be recorded on the optical disk is arranged, and A difference between the n-th data (n is an integer) and the (n-1) -th data in the data string, and creating conversion data composed of 1,0, -1 based on the difference; A data recording method for an optical disc is proposed which comprises a step of recording three states of 1, 0, -1 in correspondence with three recording states of a large recording mark, a small recording mark and a blank on the optical disc.

According to a second aspect of the present invention, in the optical disc data recording method, the step of arranging binary data to be recorded on the optical disc and the data 0 in the arrayed data string correspond to 0 and the data 1 alternates. Corresponding to 1 and −1, and converting the three states of the converted data of 1, 0, −1 into three recording marks on the optical disc: a large recording mark, a small recording mark, and a blank. We propose a method for recording data on an optical disc, which comprises a step of recording according to the state.

Further, in claim 3, the n-th data (n is an integer) and n- in the binary data string to be recorded are recorded.
The difference of the first data is taken, and based on the difference 1,
An optical disc in which converted data composed of 0, -1 is created, and data is recorded in three recording states of a large recording mark, a small recording mark, and a blank corresponding to three states of the converted data, 1, 0, -1. Data reproduction method, the reproduction waveform level of the optical disc is compared with predetermined high slice level and low slice level at a predetermined timing to set the recording state of the optical disc to 1, 0, -1.
Of the reproduction signal and the step of adding the (n-1) th reproduction data to the nth reproduction signal in the discriminated reproduction signal to generate the nth reproduction data. We propose a data reproduction method.

According to a fourth aspect of the present invention, converted data is created by making the data of 0 in the binary data string to be recorded correspond to 0, and the data of 1 alternately correspond to 1 and -1. Large recording marks, small recording marks, and blanks corresponding to three states of converted data of 1, 0, -1
A method for reproducing data on an optical disc in which data is recorded in one of the recording states, wherein a reproduction waveform level of the optical disc is compared with predetermined high slice level and low slice level at a predetermined timing to determine the recording state of the optical disc. A step of discriminating a reproduction signal of any one of 1, 0 and -1, and the reproduction data being 1 when the discriminated reproduction signal is 1 or -1, and the reproduction data being 0 when the reproduction signal is 0. We propose a method for reproducing data from an optical disk, which comprises the step of generating reproduction data by doing so.

[0009]

According to the optical disk data recording method of the first aspect of the present invention, binary data to be recorded on the optical disk is arrayed, and the n-th data (n is an integer) and n in the arrayed data string are arranged. The difference of the -1st data is obtained, and the converted data of 1, 0, -1 is created based on the difference. After this, the conversion data 1, 0,-
Data is recorded on the optical disc by making the three states of 1 correspond to the three recording states of the large recording mark, the small recording mark, and the blank on the optical disc. As a result, the recording marks recorded on the optical disc correspond to the data difference, large recording marks and blanks are not formed continuously, and large recording marks and blanks are recorded alternately, resulting in large recording. Small recording marks are continuously formed on portions other than the marks and blanks.

According to a second aspect of the present invention, binary data to be recorded on the optical disc is arranged, data 0 in the arranged data string is associated with 0, and data 1 is alternately 1 and -1. Correspondingly, converted data is created.
After this, the three states of 1,0, -1 of the converted data are recorded with a large recording mark, a small recording mark,
Data is recorded on the optical disc in correspondence with the three blank recording states. As a result, large recording marks and blanks are not continuously formed on the optical disk, large recording marks and blanks are alternately recorded, and large recording marks and small recording marks continue in areas other than blanks. Formed.

According to a third aspect of the present invention, the difference between the n-th data (n is an integer) and the (n-1) -th data in the binary data string to be recorded is calculated, and the difference between Converted data composed of 0, -1 is created, and the three states of the converted data, 1, 0, -1, are associated with three recording states of a large recording mark, a small recording mark, and a blank on the optical disc, When the data is reproduced from the optical disc on which the recording is performed, the reproduction waveform level of the optical disc is compared with the predetermined high slice level and the predetermined low slice level at a predetermined timing, and the recording state of the optical disc is 1,0. , -1, and output as a reproduction signal. Further, the n-1th reproduction data is added to the nth reproduction signal in the discriminated reproduction signal to generate the nth reproduction data,
Data is reproduced.

According to a fourth aspect of the present invention, the binary data to be recorded are arrayed, the data 0 in the arrayed data string corresponds to 0, and the data 1 alternates 1 and −.
Converted data is created in correspondence with 1, and three states of 1,0, -1 of the converted data are associated with three recording states of a large recording mark, a small recording mark, and a blank on the optical disc, When reproducing data from an optical disc on which data has been recorded, the reproduction waveform level of the optical disc is compared with predetermined high slice level and low slice level at a predetermined timing, and the recording state of the optical disc is 1. It is discriminated as either 0 or -1 and is output as a reproduction signal. Further, the discriminated reproduction signal is 1
Alternatively, when -1 is set, the reproduction data is set to 1, and when the reproduction signal is 0, the reproduction data is set to 0 to generate the reproduction data, and the data is reproduced.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram for explaining the first embodiment of the present invention. In the figure, 1 is a large recording mark, 2 is a small recording mark, 3 is a blank, 4 is a first slice level for detection, and 5 is a second slice level for detection.

The data recording method and data reproducing method in the first embodiment will be described below. FIG. 1A shows a process of arranging binary data to be recorded on the optical disc.
Further, (b) shows a step of creating the converted data by taking the n-th data (n is an integer) and the (n-1) th data difference with respect to the arranged data.

Further, after the above-mentioned steps, the three states of 1,0, -1 of the converted data are changed into three recording states of a large recording mark 1, a small recording mark 2 and a blank 3 on the optical disc medium. The data is recorded on the optical disk medium in association with each other. Specifically, as shown in (c) of FIG.
When recording a large recording mark 1 corresponding to the converted data 1, a strong recording power is applied to the optical disk, and when recording a small recording mark 2 corresponding to the converted data 0, an intermediate recording power is applied to the optical disk. Irradiate.

Further, for recording a blank (space) 3 corresponding to -1 of the converted data, a weak recording power or a read power used during data reproduction is applied to the optical disk. Here, when overwriting is performed on an optical disk capable of rewriting data, the irradiation power of light at the time of recording the blank 3 is for erasing a mark previously recorded on the optical disk to be recorded. Power,
Determined by erase characteristics.

In this way, the optical disk medium shown in FIG.
As shown in (d), a large recording mark 1, a small recording mark 2 and a blank 3 are formed. Here, there is a blank (space) 3 immediately after the large recording mark 1.

Next, a method of reproducing a signal from the optical disc on which data is recorded as described above will be described. Figure 1
The reproduced waveform when the data of the optical disc on which the mark as shown in (d) is recorded is reproduced becomes the waveform shown in (e) of FIG.

At the time of reproduction, the level of the reproduced waveform shown in FIG. 1 (e) is compared with the first slice level 4 and the second slice level 5 at the clock timing shown in FIG. 1 (f). , And the reproduced signals of 1, 0, −1 are discriminated based on the comparison result.

Here, the reproduction signal level is 1 when the level exceeds the first slice level 4, 0 when the level is between the first slice level 4 and the second slice level 5, and the second. If the slice level is 5 or less, it is discriminated as -1.

The reproduced signal at this time is shown in FIG. Further, in order to obtain the reproduction data shown in FIG. 1 (h), the operation of adding the value of the previous reproduction data to the value of the reproduction signal, which is an operation reverse to that at the time of recording, is performed. In this way, the recorded data can be reproduced.

Here, the reproduction clock is the first reproduction waveform.
It can be generated by utilizing the fact that the center level between the slice level 4 and the second slice level 5 is always 180 degrees out of phase with the clock. Also,
As is well known, clock bits may be separately formed on the optical disk.

In the first embodiment described above, the method of comparing with the simple slice level is used when the reproduced signal is obtained from the reproduced waveform, but the level of the reproduced waveform detected in synchronization with the clock is A / D conversion, the level is 1,
The maximum likelihood detection with conversion recording in which -1 is generated after 1 is calculated while calculating the probability that the reproduced signal is 0 or -1.

Further, the recording data is previously (1,
7) Run-Length-Limited code (RLL), (2,7)
Modulation processing such as RLL may be performed.

As described above, since there is always a blank (space) 3 after 1 of a large recording mark, thermal interference during recording becomes constant, and before phase change or overwrite recording on a magneto-optical overwrite medium. Unerased data can be reduced and overwrite noise can be reduced.

Further, even if a recording mark is formed large due to power fluctuations, environmental temperature fluctuations, etc., there is no temporal fluctuation in the position where the maximum value and the minimum value of the reproduced waveform occur.
By changing the slice level during playback,
The reproduced signal can be detected stably.

Therefore, the recording density of the data is Pulse Widt
Stable recording can be realized even though it is the same as when using h Modulation recording (PWM). Furthermore, even during reproduction, since the signal component has no DC component or the DC component is constant, a reproduction system in which low-frequency noise is suppressed can be realized, and data reproduction with high S / N can be performed. .

Next, a second embodiment of the present invention will be described.
FIG. 3 is a diagram for explaining the second embodiment of the present invention. In the figure, 1 is a large recording mark, 2 is a small recording mark, 3 is a blank, 4 is a first slice level for detection, and 5 is a second slice level for detection.

In FIG. 3 (a), 2 is recorded on the optical disk.
The process of arranging decimal data is shown. In addition, in (b), data 0 corresponds to 0 in the arranged data,
The process of making converted data by alternately making data 1 correspond to 1 and -1 is shown.

Further, after passing through these steps, the three states of 1,0, -1 of the converted data are respectively recorded into three recording states of a large recording mark 1, a small recording mark 2 and a blank 3 on the optical disc medium. Correspond and record. Specifically, as shown in (c) of FIG. 3, when recording a large recording mark 1 corresponding to 1 of conversion data, a strong recording power is applied to the optical disk and a small recording mark corresponding to 0 of conversion data is applied. When recording the recording mark 2, an intermediate recording power is applied to the optical disc. In addition, a weak recording power for recording the blank 3 corresponding to -1 of the converted data or a read power used during data reproduction is applied to the optical disc.

Further, when overwriting is performed in the same manner as described above, the irradiation power of light at the time of blanking is the power for erasing the previously recorded mark and is determined by the erasing characteristics.

In this way, a large recording mark 1 and a small recording mark 2 are formed on the optical disk medium, as shown in FIG. 3 (d). Large recording marks 1 and blanks (spaces) 3 are generated alternately. The reproduced waveform at this time becomes the waveform shown in FIG.

Next, a method of reproducing a signal from the optical disc on which data is recorded as described above will be described. Of FIG.
The reproduced waveform is discriminated using the first slice level 4 and the second slice level 5 with the clock shown in (g). Here, when the first slice level 4 is exceeded, it is 1, when it is between the first slice level 4 and the second slice level 5, it is 0, and when it is between the second slice level 5. Is discriminated as 0, and the second slice level 5 or less is discriminated as -1. The reproduced signal at this time is shown in FIG.

Further, in order to obtain the reproduction data shown in FIG. 3 (i), the reproduction data when the reproduction signal is 1 or -1 is set to 1, and the reproduction data when the value of the reproduction signal is 0 is set to 0. Perform the reverse operation of recording. In this way, the recorded data can be reproduced.

Here, the reproduction clock can be generated from the zero-cross position of the waveform obtained by differentiating the reproduction waveform (waveform of FIG. 3 (f)). Further, as is well known, the clock bit may be separately formed on the optical disc.

In the second embodiment, the method of using a simple slice level to obtain a reproduced signal from the reproduced waveform has been described. However, the level of the reproduced waveform detected in synchronization with the clock is A / D converted. However, it is also possible to calculate the probability that the reproduced signal has a level of 1, 0, -1 and detect the maximum likelihood with a conversion rule in which -1 is alternately generated after 1 is generated.

Further, for the recording data, (1,
A modulation process such as 7) RLL or (2,7) RLL may be performed.

As described above, the first embodiment is also used in the second embodiment.
Since large recording marks 1 and blanks (spaces) 3 are alternately generated in the same manner as in the first embodiment, the thermal interference at the time of recording becomes constant, and the phase change or the previous data at the time of overwrite recording on the magneto-optical overwrite medium is performed. It is possible to reduce the unerased residue and reduce the overwrite noise. Even if a recording mark is formed large due to power fluctuations, environmental temperature fluctuations, etc., there is no temporal change in the position where the maximum value of the reproduction waveform is obtained and the position where the maximum value is obtained, so change the slice level during reproduction. Thus, the reproduced signal can be detected stably.

Further, in the second embodiment, the occurrences of 1 and -1 are half as compared with the first embodiment, so that the reproduction frequency band can be narrowed and noise can be suppressed.

Therefore, although the data recording density is the same as that when PWM is used, stable recording can be realized. Further, even at the time of reproduction, since the signal component has no DC component or the DC component is constant, a reproduction system in which low-frequency noise is suppressed can be realized, and data reproduction with high S / N can be performed. it can.

In the above embodiments, the recording power is changed to change the size of the recording mark, but the recording pulse width may be changed as shown in FIGS.

In the recording method shown in FIG. 4, the pulse width is widened when the data 1 is recorded and the pulse width is narrowed when the data 0 is recorded while keeping the recording power constant.

In the recording method shown in FIG. 5, the data 1
When recording, the pulse width is widened and the power is strengthened, and when data 0 is recorded, the pulse width is narrowed and the power is weakened.

In the above-described embodiment, the large recording mark 1 and the small recording mark 2 are recorded independently, but a space between these recording marks other than the blank (space) 3 is recorded. The same effect can be obtained even when connected with.

[0045]

As described above, according to the first aspect of the present invention, the recording marks recorded on the optical disk correspond to the data difference, and large recording marks and blanks are not continuously formed. Further, since large recording marks and blanks are alternately recorded on the optical disc, and small recording marks are continuously formed in portions other than the large recording marks and blanks, the DC component is constant. Therefore, thermal interference during recording is constant, and control during recording can be easily performed. Further, in an overwrite medium such as a phase change, the space area has a constant length, and overwrite noise can be reduced. Furthermore, even during reproduction, since the signal component has no DC component or the DC component is constant, a reproduction system in which low-frequency noise is suppressed can be realized, and data reproduction with high S / N can be performed. .

According to the second aspect, large recording marks and blanks are not continuously formed on the optical disk, and large recording marks and blanks are recorded alternately, except for large recording marks and blanks. Since small recording marks are continuously formed in the area of, the DC component is constant. Therefore, the thermal interference during recording is constant,
The control at the time of recording can be easily performed. Further, in an overwrite medium such as a phase change, the space area has a constant length, and overwrite noise can be reduced. Furthermore, even during reproduction, since the signal component has no DC component or the DC component is constant, a reproduction system in which low-frequency noise is suppressed can be realized, and data reproduction with high S / N can be performed. .

According to the third aspect, the recording marks recorded on the optical disc correspond to the data difference, large recording marks and blanks are not formed continuously, and the recording marks are recorded on the optical disc. Large recording marks and blanks are alternately recorded, and small recording marks are continuously formed in portions other than large recording marks and blanks, so that the DC component is constant. Therefore, at the time of reproduction, since there is no DC component in the signal component or the DC component is constant, a reproduction system in which low-frequency noise is suppressed can be realized, and data reproduction with high S / N can be performed. it can.

Further, according to the fourth aspect, a large recording mark and a blank are not continuously formed on the optical disk, and a large recording mark and a blank are alternately recorded. Since small recording marks are continuously formed in the area of, the DC component is constant. Therefore, at the time of reproduction, since the signal component has no DC component or the DC component is constant, a reproduction system in which low-frequency noise is suppressed can be obtained, and the S / N ratio can be reduced.
It is possible to perform high-quality data reproduction.

[Brief description of drawings]

FIG. 1 is a diagram illustrating a first embodiment of the present invention.

FIG. 2 is a diagram illustrating a conventional example.

FIG. 3 is a diagram illustrating a second embodiment of the present invention.

FIG. 4 is a diagram for explaining another embodiment of recording power setting in the present invention.

FIG. 5 is a diagram for explaining another embodiment of recording power setting in the present invention.

[Explanation of symbols]

1 ... Large recording mark, 2 ... Small recording mark, 3 ... Blank (space), 4 ... First slice level for detection, 5 ... Second slice level for detection.

Claims (4)

[Claims] 1. A method for recording data on an optical disc, comprising: arranging binary data to be recorded on the optical disc; and n-th data (n is an integer) and (n-1) -th data in the arranged data string. A step of taking a difference and creating conversion data composed of 1,0, -1 based on the difference; a large recording mark and a small recording mark on the optical disk for three states of the conversion data 1,0, -1 And a step of recording corresponding to three blank recording states. 2. A method of recording data on an optical disk, comprising the step of arranging binary data to be recorded on the optical disk, and the data 0 in the arrayed data string is made to correspond to 0, and the data 1 is alternately 1 and -1. And a step of creating converted data in correspondence with the three states of 1,0, -1 of the converted data corresponding to three recording states of a large recording mark, a small recording mark, and a blank on the optical disc. A method for recording data on an optical disc, which comprises a step of recording. 3. Converted data consisting of 1, 0, -1 based on the difference between the n-th data (n is an integer) and the (n-1) th data in the binary data string to be recorded. To create a large recording mark, a small recording mark corresponding to the three states of 1, 0, −1 of the converted data,
A data reproducing method of an optical disc in which data is recorded in three blank recording states, wherein a reproduction waveform level of the optical disc is compared with predetermined high slice level and low slice level at a predetermined timing, A step of discriminating the recording state into a reproduction signal of any one of 1, 0 and -1, and an n-th reproduction signal in the discriminated reproduction signal.
A method for reproducing data from an optical disk, comprising the step of adding first reproduction data to generate n-th reproduction data. 4. Data of 0 in a binary data string to be recorded is made to correspond to 0, and data of 1 is alternated with 1 and −.
An optical disc in which converted data is created corresponding to 1 and data is recorded in three recording states of a large recording mark, a small recording mark, and a blank corresponding to three states of the converted data: 1, 0, -1. The method for reproducing data according to claim 1, wherein the reproduction waveform level of the optical disc is compared with predetermined high slice level and low slice level at a predetermined timing to set the recording state of the optical disc to any one of 1, 0 and -1. A step of discriminating the reproduced signal, and a step of generating the reproduced data by setting the reproduced data to 1 when the discriminated reproduced signal is 1 or -1 and setting the reproduced data to 0 when the reproduced signal is 0. A method for reproducing data from an optical disk, comprising: