JP2001351239A - Data recording and reproducing method of optical disk - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve such the problem of conventional recording methods of optical disk using mutlipulses that the elevation of recording rate and the execution of power control are difficult and the number of recording compensating parameters are required. SOLUTION: A recording pulse of single pulse is used in the recording of the shortest mark 108 and a two-stage pulse composed of the first half and the second half is used in the recording of a long mark 125. Front edge positions 115, 118 of the recording pulse are determined by the relation between a length of immediately preceding space and a length of self-mark, in such a manner that the front edge position in a reproduced waveform of every mark length is optimized. On the assumption that the rear edge position of the recording pulse of every mark length is fixed as the position, where a specified relative positional relation with the edge of the recording clock is satisfied, power 122 of the recording pulse 101 of the shortest mark is determined, in such a manner that rear edge position 112 of reproduced waveform of the shortest mark is optimized and power 124 of the second half pulse 104 is determined at every mark length, in such a manner that the rear edge position 123 of reproduced waveform of the long mark is optimized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data recording / reproducing method for a rewritable optical disk using a mark edge recording method, and a method of adjusting a recording pulse waveform (write strategy) and a recording compensation parameter in the data recording / reproducing method.

[0002]

2. Description of the Related Art As a rewritable optical disc standard, D
There is a VD-RAM. Optical disk single-sided capacity is 2.6GB
DVD-RAM has already been put into practical use and has a capacity of 4.
A DVD-RAM with the capacity increased to 7 GB is currently under development. A method of recording on a phase-change type optical disk employed in DVD-RAM-4.7 GB will be described with reference to FIG.

FIG. 16A shows data 900 as an example of digital data to be recorded.
1T (T is a recording clock cycle) Hi level signal 901
And a 7T Lo level signal 902 and a 3T Hi level signal 903. FIG. 16B shows a waveform of a recording pulse 910 of a laser beam corresponding to the data 900. FIG.
6 (c) is an amorphous mark 9 formed on the recording track 934 of the optical disc in response to the recording pulse 910.
31 and 932 and the recording state of the space 933 of the crystal are shown.

In order to record a mark 931 and a space 933 corresponding to data 900, a recording pulse 910
As for the mark forming portion of the recording track 934,
The first pulse 911 of the peak power 924, the half of the peak power 924 and the third bias power 923
Multipulse 912 alternating at every T, peak power 92
The laser beam is irradiated with the last pulse 913 of 4 and the cooling pulse 914 of the second bias power 922. Further, the first bias power 921 is irradiated to the space 933 with a laser beam. Such a waveform of the recording pulse 910 is generally called a “write strategy”. In order to realize an appropriate mark shape in recording on an optical disk, the above-described four types of power and time conditions of each pulse are individually defined for each optical disk. Further, in order to optimize the position of the edge of the reproduction waveform of the mark, the time condition of the position of each edge of the recording pulse is adaptively controlled for each mark and space pattern (Reference: Japanese Patent No. 2679596). 17A and 17B show a first pulse start position table and a last pulse end position table as recording compensation conditions for DVD-RAM-4.7 GB. That is, as the start position of the first pulse 911 for recording the mark 931 shown in FIG. 16C, 4 × 4 = 4 × 4 =
As the end positions of the last pulse 913, 16 × 4 × 4 = 4 × 4 =
16 types of time conditions are defined respectively. The procedure for obtaining these conditions is generally called “recording compensation”.

[0005]

The above conventional DVD-R
The AM write strategy uses a multi-pulse 912 in which one pulse is half the width of the recording clock cycle. Due to the demand to further increase the access speed of optical discs,
It is conceivable to increase the frequency of the recording clock. In this case, the recording clock cycle becomes inversely small, and it is not easy to generate an accurate multi-pulse 912 unless the rising characteristic of the recording laser beam is extremely high. An optical disk device that requires an extremely high-speed laser drive circuit has a first problem that it is difficult to reduce component costs.

In the case where the laser power during recording is detected and controlled every time a mark is formed, if the multipulse 912 for high-speed switching is included in the recording pulse 910, the power monitor waveform of the laser light becomes multipulse. 91
There is a second problem that the processing circuit greatly fluctuates in two parts and the processing circuit becomes complicated.

[0007] Further, to meet the demand for increasing the capacity of the optical disk, it is conceivable to record smaller marks at a high density. When the high-density recording is further performed by using the mark edge recording method, if the amplitude of the reproduction signal of the shortest mark is extremely smaller than other long marks and is buried in noise, a reproduction error of the optical disc may be caused. There were three issues.

Further, if only the position of the edge of the recording pulse 910 is changed in order to optimize the position of the edge of the reproduction signal, even if the recording is compensated, the recording power will be biased and the mark shape will be changed. May be distorted. In particular, when the size of the front and rear ends of the mark is different, the amplitude of the front and rear ends of the reproduction signal of the mark becomes unbalanced, which may cause an error when digitizing the reproduction signal. Even if the multi-value detection means is used for the purpose of reducing errors, there is a fourth problem that a sufficient effect cannot be obtained due to distortion of the mark shape.

Further, the fact that there are many parameters for the recording compensation condition means that the procedure of the recording compensation is complicated and takes a long time. There is a fifth problem that it is difficult to shorten the time.

The present invention solves the above-described first to fifth problems. In the mark edge recording method, a multi-pulse having a width smaller than the recording clock cycle is not required, and the amplitude of the reproduction signal of the shortest mark is reduced. Recording pulse adjustment method and write strategy capable of increasing the shape distortion of a reproduction signal of a long mark and reducing the recording compensation parameter compared to the conventional method, and a method of recording and reproducing data on a rewritable optical disk using the same The purpose is to provide.

[0011]

A method for adjusting a recording pulse for recording a mark on an optical disk according to the present invention comprises:
(A) adjusting a first recording pulse for recording a shortest mark; and (b) adjusting a second recording pulse for recording a long mark, wherein the first recording pulse is a first recording pulse. The second recording pulse is a two-stage pulse including a first half pulse having a second power and a second half pulse having a third power, and the step (a) includes (a1) 1)
The position of the trailing edge of the recording pulse is determined by the first
(A2) determining the first power so that the position of the trailing edge of the reproduction waveform of the shortest mark is optimized, and (a2) fixing the first power to a position satisfying a predetermined relative positional relationship with the edge. a3) determining the position of the leading edge of the first recording pulse based on the length of the space immediately before the shortest mark so that the position of the leading edge of the reproduction waveform of the shortest mark is optimized. (B1) fixing the position of the trailing edge of the first half pulse to a position that satisfies the predetermined relative positional relationship with the second edge of the recording clock; and (b2) Fixing the position of the trailing edge of the latter half pulse to a position satisfying the predetermined relative positional relationship with the third edge of the recording clock; (b)
3) determining the second power; (b4)
Determining the third power such that the position of the trailing edge of the reproduction waveform of the long mark is optimized; (b)
5) determining the position of the leading edge of the first half pulse based on the length of the space immediately before the long mark and the length of the long mark so that the position of the leading edge of the reproduced waveform of the long mark is optimized; And thereby the above object is achieved.

The combination of the first power and the position of the leading edge of the first recording pulse is such that the position of the leading edge and the position of the trailing edge of the reproduction waveform of the shortest mark are optimized. May be set to a combination that maximizes the reproduction amplitude of the shortest mark.

In the combination of the second power, the third power, and the position of the front edge of the first half pulse, the position of the front edge and the position of the rear edge of the reproduction waveform of the long mark are appropriate. Of the plurality of combinations, the combination may be set such that the reproduction amplitude of the long mark becomes substantially flat.

The first power and the second power may have the same magnitude. The position of the trailing edge of the second half pulse is a predetermined clock cycle after the position of the trailing edge of the first half pulse. May be fixed at the position.

A method for recording a mark on an optical disk according to the present invention is a method for recording a mark on an optical disk by using the above-described method for adjusting a recording pulse, wherein the mark is adjusted at least according to the step (a). Recording the shortest mark based on a recording pulse; and recording the long mark based on the second recording pulse adjusted at least according to step (b), whereby the object is achieved. Achieved.

The method for recording a mark on an optical disk according to the present invention comprises the following steps: (a) a first pulse for recording the shortest mark, which is a single pulse having a fixed position of the rear end edge and a fixed power;
Adjusting the leading edge of the recording pulse based on the length of the space immediately before the shortest mark; and (b) recording the shortest mark using the first recording pulse adjusted in step (a). And (c) a two-stage pulse including a first half pulse and a second half pulse having different powers, wherein the position and the power of the rear end edge of each of the first half pulse and the second half pulse are fixed, and a predetermined length. Adjusting the leading edge of the second recording pulse for recording the long mark based on the length of the space immediately before the long mark; and (d) adjusting the second recording pulse adjusted in the step (c). Recording the long mark with the use of the above, thereby achieving the above object.

The method of adjusting a recording pulse for recording a mark and a space on an optical disk according to the present invention comprises the steps of (a)
Adjusting a first recording pulse for recording the shortest mark; and (b) adjusting a second recording pulse for recording the long mark.
Adjusting a recording pulse, and (c) adjusting a third recording pulse for recording a space between the marks, wherein the first recording pulse is a single pulse having a first power; The second recording pulse is the second recording pulse.
A two-stage pulse including a first half pulse having a power and a second half pulse having a third power, wherein the third recording pulse is a single pulse having a fourth power, and the step (a) comprises: (a1) Fixing the position of the trailing edge of the first recording pulse to a position satisfying a predetermined relative positional relationship with the first edge of the recording clock; (a2)
Determining the first power so that the position of the trailing edge of the reproduction waveform of the shortest mark is optimized;
(A3) determining the position of the leading edge of the first recording pulse so that the position of the leading edge of the reproduction waveform of the shortest mark is optimized; and the step (b) includes (b1) Fixing the position of the trailing edge of the first half pulse to a position satisfying the predetermined relative positional relationship with the second edge of the recording clock;
(B2) determining the second power; and (b)
3) determining the position of the trailing edge of the second half pulse and the third power based on the length of the long mark so that the position of the trailing edge of the reproduction waveform of the long mark is optimized; (B4) determining the position of the leading edge of the first half pulse based on the length of the long mark so that the position of the leading edge of the reproduced waveform of the long mark is optimized. (C)
(C1) The step of determining the fourth power based on the length of the space so as to eliminate the position fluctuation of the edge of the reproduction waveform of the mark due to the thermal interference between the marks, thereby achieving the above object Is done.

The combination of the first power and the position of the leading edge of the first recording pulse is such that the positions of the leading edge and the trailing edge of the reproduction waveform of the shortest mark are optimized. May be set to a combination that maximizes the reproduction amplitude of the shortest mark.

The combination of the second power, the third power, and the position of the front edge of the first half pulse is such that the position of the front edge and the position of the rear edge of the reproduction waveform of the long mark are appropriate. Of the plurality of combinations, the combination may be set such that the reproduction amplitude of the long mark becomes substantially flat.

The first power and the second power may have the same magnitude.

A method of recording a mark on an optical disk according to the present invention is a method of recording a mark on an optical disk using the above-described method of adjusting a recording pulse, wherein the method comprises the steps of: Recording the shortest mark based on a recording pulse; recording the long mark based on the second recording pulse adjusted at least according to the step (b); and adjusting at least the length mark according to the step (c). Recording the space based on the third recording pulse, whereby the object is achieved.

The method of recording a space between marks on an optical disk according to the present invention comprises the steps of: (a) changing the position of the edge of the reproduced waveform of the mark due to thermal interference between the marks;
Adjusting the power of the recording pulse, which is a single pulse for recording the space, based on the length of the space; and (b) changing the space using the recording pulse adjusted in the step (a). Recording, whereby the above object is achieved.

[0023]

FIG. 3 is a diagram showing a recording / reproducing apparatus 1000 for an optical disk 9 described as an embodiment of the present invention. The recording / reproducing apparatus 1000 is used in common in Embodiments 1 to 3 described later.

First, each part will be described. As shown in FIG. 3, the recording / reproducing apparatus 1000 generates a recording clock 1 for generating a recording clock 1 serving as an operation reference time axis of the recording / reproducing apparatus 1000, and generates information to be recorded on the optical disc 9 as recording data 3. Recording data generating means 2
Recording compensation condition adjusting means 2 for adjusting recording compensation condition 5
1, a recording compensator 4 for generating a recording pulse 6 for driving a laser (not shown) from the recording data 3, and a laser beam 8 driven by the laser based on the recording pulse 6 and subjected to intensity modulation. A head 7 for recording data by irradiating the optical disk 9 and a motor 10 for rotating the optical disk 9 are provided.

The recording clock 1 corresponds to the recording data generating means 2
And output to the recording compensating means 4. The form of the recording data 3 is a PWM signal in clock units, and in the embodiment of the present invention, the run length is limited to 3T (T is the recording clock cycle) and the maximum is 11T modulation data, but is not limited to this. The recording compensation condition adjusting means 21 controls the position of the power and the pulse for each mark and space for recording the Hi level signal period of the recording data 3 corresponding to the mark on the optical disc and the Lo level signal period corresponding to the space. Are adjusted and determined as the recording compensation condition 5. The recording compensating unit 4 receives the recording clock 1, the recording data 3, and the recording compensation condition 5, and outputs a recording pulse 6 to the head 6. Recording clock generating means 20
And the recording compensation condition adjusting means 21
0 may be provided outside.

The optical disk 9 has a form in which a phase change film or the like is formed on a base material on which a spiral recording track is formed, and a mark and a space are formed by the irradiation heat of the laser beam 8 so that data can be written. Or a rewritable optical disk.

The recording / reproducing apparatus 1000 corrects the frequency characteristic of the reproduced signal 11 from the head 7 attenuated in a high frequency range, and outputs an equalized reproduced signal 13 of an analog signal.
Binarizing means 14 for binarizing the equalized reproduction signal 13 at the slice level and outputting a digital binarized pulse 15
A pulse interval measuring means 16 for detecting a rising edge or a falling edge of the binarized pulse 15 to measure an edge-to-edge interval and outputting a time measurement result 17; Amplitude measuring means 1 for measuring amplitude information such as symmetry and outputting an amplitude measurement result 19
8 is further provided. The time measurement result 17 and the amplitude measurement result 19 are input to the recording compensation condition adjusting means 21 and are used as data for adjusting the parameters of the power and pulse position for each mark and space and the write strategy.

At the time of reproduction, the head 7 irradiates the optical disk 9 with a laser beam 8 having a reproducing power, and photoelectrically converts reflected light from marks and spaces recorded on the optical disk 9 by a detector (not shown) to reproduce the data. Output as signal 11. The equalizer 12 may be, for example, a standard equalizer using a combination of a transversal filter and a Bessel low-pass filter, or a non-linear equalizer using a combination of an amplitude limiter and a standard equalizer.

The binarizing means 14 includes, for example, a duty feedback binarizing circuit that controls the slice level so that the integrated value of the output binarized pulse is constant, or a binary for multi-value detection by the partial response method. A conversion circuit may be used. The pulse interval measuring means 16 is, for example, a time interval analyzer or an L dedicated to the recording / reproducing apparatus 1000.
It may be an SI circuit or the like. The amplitude measuring means 18 is, for example,
Oscilloscope or LSI dedicated to the recording / reproducing device 1000
It may be a circuit or the like.

It is assumed that the recording / reproducing apparatus 1000 implements the data recording / reproducing method for an optical disk of the present invention. By setting the position and power value of the edge of the recording pulse, which will be described later, as the recording compensation condition 5 in the recording compensating means 4,
A mark is recorded on the optical disc 9. The reproduction signal waveform of the mark is output as an equalized reproduction signal 13 and the amplitude measurement means 1
8 is observed. The edge of the mark reproduction signal is output as a binarized pulse 15 and observed by the pulse interval measuring means 16. In the following description, a mark having a length of 3T is abbreviated as 3Tm, and a space having a length of 4T is abbreviated as 4Ts.

(Embodiment 1) FIG. 1 shows a data recording / reproducing method for an optical disk described as Embodiment 1 of the present invention, and a method of adjusting a recording pulse waveform (write strategy) and a recording compensation parameter in the data recording / reproducing method. FIG.

In FIG. 1, a vertical dotted line represents a time unit, and one scale corresponds to one cycle T of a recording clock. From the top, FIG. 1A shows the Hi level signal 100 as a mark,
This is recording data in which Lo level signals 143, 144 and 145 are allocated to spaces. This shows the waveform of the recording data 3 in the recording / reproducing apparatus 1000 of FIG. 1A shows the Hi level signal 100 of the recording data when the space immediately before the shortest mark 108 of 3Tm is 3Ts, 4Ts, and the length of the space immediately before is 5Ts or more. Each has a connected form.

FIG. 1B shows a Hi level signal 1 having a length of 3T.
Recording pulses 101, 101 'and 10 corresponding to 00
1 "and recording pulses 163, 164, and 165 corresponding to Lo level signals 143, 144, and 145, and the vertical axis represents laser power. This is modulated by recording pulse 6 in recording / reproducing apparatus 1000 in FIG. Is equivalent to the intensity of the laser beam 8.

FIG. 1C is a schematic diagram of the mark 108 and the spaces 153, 154 and 155 recorded on the track 150 of the optical disk 9 by the laser beam 8.
The shaded portion shown in FIG. 1C is a mark 108 corresponding to the amorphous state of the phase change film, and the other portions are spaces 153, 154 and 155, corresponding to the crystalline state of the phase change film.

The solid line curve shown in FIG.
8, the spaces 153, 154, and 155 are reproduced, and correspond to the equalized reproduction signal 13 in FIG. FIG.
The upper and lower dotted lines shown in (d) represent the signal amplitude range to be reproduced, and the dashed line at the center represents the slice level 110 when binarizing. 1 (e) to 1 (h).
1 (i) to 1 (l) show a long mark 129 of 5 Tm or more when recording and reproducing a long mark 125 of 4 Tm.
Represents recording data, recording pulses, recording marks, and equalized reproduction signals when recording and reproducing are performed. Hereinafter, the recording / reproducing method according to the present embodiment will be described in order.

<First requirement> Length 3T shown in FIG. 1 (a)
In order to record the shortest mark 108 corresponding to the Hi level signal 100 of FIG.
The recording pulses 101 and 10 which are single pulses shown in FIG.
One 1 ′ or 101 ″ is irradiated.

<Second Requirement> In order to record a long mark other than the shortest mark 108, for example, a long mark 125 corresponding to the 4T-length Hi level signal 102 shown in FIG. Recording pulses 171, 171 ′ or 171 ″ which are two-stage pulses shown in FIG.
Is irradiated one at a time. The recording pulse 171 is the first half pulse 103
The recording pulse 171 ′ includes the first half pulse 103 ′ and the second half pulse 104, and the recording pulse 171 ″ includes the first half pulse 103 ″ and the second half pulse 104.
And

A long mark having a length of 5 Tm or more, for example, a Hi level signal 105 having a length of 5 T shown in FIG.
Similarly, to record the long mark 129 corresponding to
A recording pulse 172, 172 'or 172 "which is a two-step pulse shown in FIG.
Irradiation. The recording pulse 172 includes the first half pulse 106 and the second half pulse 107, the recording pulse 172 ′ includes the first half pulse 106 ′ and the second half pulse 107, and the recording pulse 172 ″ includes the first half pulse 106 ″ and the second half pulse 107.

Here, the edge of the reproduction waveform of the mark is defined. The leading edge of the reproduction waveform of the mark is the rising edge of the binarized pulse 15 shown in FIG.
In the present embodiment shown in (d), the equalized reproduction signal 109 when reproducing the shortest mark 108 and the slice level 11
It points to the intersection point 111 with 0. The trailing edge of the mark reproduction waveform is the falling edge of the binarized pulse 15, and in the present embodiment shown in FIG.
08 indicates the intersection point 112 at the time of reproduction.

Further, the meaning that the position of the edge of the reproduction waveform of the mark is appropriate will be described. The edges of the reproduced waveform of the mark are as defined above, and the proper position means that all edge intervals are integer multiples of a clock unit. For example, FIG. 1 shows a state in which the position of the edge of the reproduction waveform of the mark is exactly over the vertical dotted line. When the position of the edge of the reproduction waveform of the mark is proper, the waveform of the binarized pulse 15 becomes equal to the waveform of the recording data (for example, the waveform of the recording data shown in FIG. 1A).

In order to optimize the edge of the reproduced waveform of the mark, the position of the edge of the recorded mark shape itself does not necessarily have to be in clock units. It suffices if the position of the edge eventually becomes a correct position. For example, the distance between the front edge and the rear edge of the Hi level signal 100 having a length of 3T and the intersection 1
It is sufficient that the interval between the intersection 11 and the intersection 112 is equal (the length of the interval between the intersection 111 and the intersection 112 is 3T).

<Third Requirement> In order to optimize the position of the leading edge of the reproduction waveform of the mark, the position of the leading edge of the recording pulse is determined by the relationship between the length of the space immediately before the mark and the length of the mark itself. . For example, as shown in FIG. 1B, the positions of the leading edges of the recording pulses 101 ″, 101 ′ and 101 corresponding to 3Tm are the position 11 of the recording pulse 101 ″ whose space immediately before the mark to be formed is 3 Ts.
3. The recording pulse 101 'of the immediately preceding space having a length of 4Ts is determined at a position 114, and the recording pulse 101 of the immediately preceding space having a length of 5Ts or more is determined at a different position as a position 115.

When the space immediately before the mark is short, the recording heat of the previous mark is conducted through the space and changes the temperature of the mark to be formed, so that the front edge of the mark to be formed fluctuates. This is generally called thermal interference. The position of the leading edge of the recording pulse is changed according to the length of the space immediately before the mark to be formed in order to cancel the thermal interference and to optimize the position of the leading edge of the reproduced waveform of the mark.

Similarly, when recording 4Tm, the positions of the leading edges of the recording pulses 171 ", 171 'and 171 are shown in FIG. 1 (f) every time the length of the space immediately before the mark to be formed is different. Positions 116, 117 and 11
Different values such as 8. Similarly, if the mark length is 5T
When recording a mark of m or more, the recording pulse 172,
The positions of the leading edges of 172 ′ and 172 ″ are changed to position 1 shown in FIG.
Different values such as 19, 120 and 121 are used.

Further, when the mark changes to 3Tm, 4Tm, 5Tm, even if the length of the immediately preceding space is the same,
The position of the leading edge of the recording pulse is changed. When the length of the mark itself is short, the formed mark size is small and heat is easily radiated to the surroundings, so it is quenched. Conversely, when the length of the mark itself is long, the latter half of the mark is also recorded continuously. Because of this, heat dissipation is poor and cooling is slow.

Therefore, depending on the difference in the length of the mark to be recorded, even if the position of the leading edge of the recording pulse is the same, the position of the leading edge of the formed mark (for example, FIG. 1)
A phenomenon occurs in which the position 108 ′) shown in FIG. This is called thermal nonlinearity depending on the length of the mark. In order to cancel the thermal non-linearity and optimize the position of the leading edge of the reproduction waveform of the mark, even when the length of the space immediately before the mark to be formed is the same 3T, when the mark to be formed is 3Tm, FIG. 1B when the positions 113 and 4Tm are shown in FIG. 1B, and FIG. 1 when the mark length is 5 Tm or more.
The position of the leading edge of the recording pulse is changed, as in a position 119 shown in (j).

As a result, the condition of the position of the leading edge of the recording pulse for optimizing the leading edge of the reproduction waveform of the mark is, as shown in FIG. 4A, the relationship between the length of the immediately preceding space and the length of the mark itself. Is a two-dimensional parameter determined by The numbers in the table shown in FIG. 4A correspond to the reference numerals indicating the positions of the respective parts shown in FIG. In addition, in the positions of the respective parts corresponding to the respective reference symbols shown in the table, the interval between the immediately preceding space and the leading edge of the recording pulse applied to form the mark does not always have a different value. Some positions may have the same value depending on the recording film characteristics and the equalizer characteristics.

<Fourth Requirement> The positions of the trailing edges of the recording pulses corresponding to the lengths of all the marks are fixed at positions satisfying a certain relative positional relationship with the edges of the corresponding recording clocks. I do. In the example shown in FIG. 1, the positions of the trailing edges of all the recording pulses are made to coincide with the corresponding edges of the recording clock.

<Fifth Requirement> In order to optimize the position of the trailing edge of the reproduction waveform of the shortest mark 108 (for example, the intersection 112), the power of the recording pulse 101, which is a single pulse, is changed. The method will be described with reference to FIG. FIG. 5 shows that when the shortest mark 108 is recorded, the power 122 of the recording pulse 101 and the position 115 of the leading edge are
The relation between the shape of the mark 108 and the equalized reproduction signal 109 when the shape is changed under the kind conditions is shown. Under the recording conditions 500, 501, 502 and 503 shown in FIG.
The upper part shows the waveform of the recording pulse 101, the middle part shows the shape of the recording track 150 and the shortest mark 108, and the lower part shows the waveform of the equalized reproduction signal 109.

Comparing the recording condition 500 and the recording condition 501 shown in FIG. 5, the recording condition 500 has a large power 122,
In the recording condition 501, the power 122 is relatively small. When the power 122 is changed from large to small, the width of the shortest mark 108 formed becomes narrow, and the level of the reproduction signal changes in a direction to decrease. In this comparative example, the edge interval (width between the intersections 111 and 112) of the equalized reproduction signal 109 viewed at the slice level 110 indicated by the dashed line is the recording pulse 1
The recording condition 501 equal to the width of 01 is the appropriate recording power.

The recording conditions 502 and 5 shown in FIG.
Compared with 03, the recording condition 502 has a large power 122, and the recording condition 503 has a relatively small power 122. When the power 122 is changed from small to large, the width of the shortest mark 108 formed becomes large, and the equalized reproduction signal 109 is formed.
Changes in the direction in which the level increases. In this comparative example, the recording condition 50 is such that the edge interval of the equalized reproduction signal 109 as viewed at the slice level 110 is equal to the width of the recording pulse 101.
2 is proper power. That is, in the recording method using a single recording pulse for the shortest mark 108, it is possible to control the position of the edge of the reproduction waveform of the mark by changing the power.

Further, when the recording condition 501 and the recording condition 502 are compared, the recording condition 501 has a small power 122 and the position 115 of the leading edge of the recording pulse 101 is in front. In the recording condition 502, the power 122 is relatively large, and the position 115 of the leading edge of the recording pulse 101 is located behind. The shape and the width of the mark 108 under the recording condition 501 and the recording condition 502 are different from each other in width and length.
At the edge of the reproduced waveform. However, the recording condition 502 is the shortest mark 1 occupying the track 150.
Since the area ratio of 08 is large, the reproduction amplitude 509 of the equalized reproduction signal 109 is larger than the recording condition 501. Even if the edge position of the same reproduced waveform can be realized, if the reproduction amplitude 509 of the equalized reproduction signal 109 is large, the rising edge of the edge becomes steep, and the time axis fluctuation (jitter) of the equalized reproduction signal 109 is small. The shortest mark 108 has a reproduction amplitude of 50
9 is smaller than other long marks (for example, the long mark 125), and it tends to be difficult to obtain sufficient quality.

Therefore, the power 122 of the recording pulse 101 and the position 115 of the leading edge for recording the shortest mark 108 are determined by the edge of the reproduced waveform of the shortest mark 108 (that is, like the recording conditions 501 and 502 in FIG. 5). While there are a plurality of combinations in which the positions of the intersections 111 and 112 are optimized, it is preferable to select a condition that maximizes the reproduction amplitude 509. 3 in FIG. 1 (b)
Tm recording power 122 and leading edge positions 113, 1
The combination of 14 and 115 depends on the position of the edge of the reproduced waveform (that is, intersections 111 and 11) as described above.
2) is selected and the condition that the reproduction amplitude 509 is maximized is selected.

<Sixth Requirement> In order to optimize the position of the trailing edge of the reproduction waveform of the long mark, the power of the second half pulse of the recording pulse is changed for each length of the long mark. The method will be described with reference to FIG. FIG. 6 shows recording conditions 650 and 6
51, 652, and 653, the length of the recording data when recording the long mark 608 having a length of 11 Tm is 11 Tm.
The relationship between the Hi level signal 630, the recording pulse 605, the shape of the long mark 608, and the equalized reproduction signal 625 is shown.
The recording conditions 650, 651, 652, and 65 shown in FIG.
3, the upper part shows the waveform of the recording pulse 605, the middle part shows the shape of the recording track 150 and the long mark 608, and the lower part shows the waveform of the equalized reproduction signal 625. The recording pulse 605 includes a first half pulse 615 and a second half pulse 600.

In the recording condition 650, since the power 601 of the second half pulse 600 is small, the long mark 60 to be formed is formed.
8 becomes narrower and shorter, and the position 603 of the trailing edge of the reproduced waveform of the long mark 608 comes closer to the proper position.

In the recording condition 651, the second half pulse 6
Since the power 601 of 00 is large, the rear end 606 of the formed long mark 608 becomes thicker and longer due to the heat storage action, and the position 607 of the rear end edge of the reproduced waveform of the equalized reproduced signal 625 of the long mark 608 is shifted from the proper position. I will come back.

On the other hand, in the recording condition 652, the second half pulse 6
In order for the power 601 of 00 to be an appropriate value, the rear end 610 of the formed long mark 608 is positioned at the front end 61 of the long mark 608.
1 and the proper length, and the position 61 of the trailing edge of the reproduction waveform of the equalized reproduction signal 625 of the long mark 608
2 is also an appropriate position. That is, in the recording method in which the recording pulse 605 is composed of the first half pulse 615 and the second half pulse 600, the position of the rear end edge of the reproduction waveform of the equalized reproduction signal 625 of the long mark 608 is changed by changing the power 601 of the second half pulse 600. It becomes possible to control.

Further, in the recording condition 653, the second half pulse 6
00 has a proper value, but the first half pulse 615
Since the value of the power 617 is lower than the value of the appropriate power 617 shown in the recording condition 652, the position 620 of the leading edge is adjusted to be temporally shorter than the appropriate edge position 619 shown in the recording condition 652. Playback signal 625
Both the position 623 of the leading edge and the position 612 of the trailing edge of the reproduced waveform are optimized.

However, thermal imbalance occurs between the front end 621 and the rear end 622 of the long mark 608, and the front end 621
And the width of the rear end 622 are different, resulting in the long mark 608.
The reproduction waveform of the equalized reproduction signal 625 is not flat but inclined. When the originally flat portion of the equalized reproduction signal 625 is inclined (distorted), even when a multi-valued discrimination method such as a partial response method is used to improve the performance when the equalized reproduction signal 625 is binarized. However, the expected performance cannot be obtained and an error may occur.

Therefore, when recording a long mark, the power of the first half pulse and the position of the leading edge of the first half pulse, and the power of the second half pulse and the position of the trailing edge are
In the presence of a plurality of combinations in which the position of the edge of the reproduction waveform of the long mark is optimized (as in the recording conditions 652 and 653 in FIG. 6), the reproduction amplitude at the front and rear ends of the long mark is reduced. It is preferable to select a condition that makes the same (that is, a reproduced waveform becomes flat).

Referring again to FIG. 1, a long mark 1 of 4 Tm
Similarly, when recording No. 25, the power 124 of the second half pulse 104 in FIG. 1F is determined so that the position 123 of the trailing edge of the waveform of the equalized reproduction signal 180 in FIG. I do. Similarly, when a long mark 129 having a length of 5 Tm or more is recorded, the position 130 of the trailing edge of the waveform of the equalized reproduction signal 181 in FIG. Second half pulse 107
Of the power 128 is determined. At this time, the recording pulse 17
The power 126 of the first half pulse 103, 103 ′ and 103 ″ is equal to the first half pulse 106, 1
06 ′ and 106 ″ may have a value different from the power 127. Also, the latter half pulse 107 of the recording pulse 172 may be used.
Of the second half pulse 10 of the recording pulse 171
4 may be different from the power 124.

The power of the latter half pulse of the recording pulse for optimizing the position of the trailing edge of the reproduction waveform of the long mark is:
The parameters are different for each length of the long mark. FIG. 4B shows a power condition for each mark's own length when the power of the first half pulse of the long mark is the same as the power of the single pulse of the shortest mark. The numbers in the table shown in FIG. 4B correspond to the powers of the respective pulses shown in FIG. The optimum value of the power of the first half pulse for each mark length is not always the same, and the value may differ for each mark length depending on the recording film characteristics and equalizer characteristics of the optical disc.

As described above, according to the recording / reproducing method satisfying the first to sixth requirements, the shortest mark 108 to the longest mark 6
All the marks up to 08 are recorded on the optical disc, and the position of the edge of the reproduced waveform of the optimized mark is achieved. Note that the above first to sixth requirements are merely in the order of description, and the order of execution may be changed.

The data recording / reproducing method of the optical disk according to the present embodiment does not use a pulse shorter than a recording clock cycle such as a conventional multi-pulse for recording a long mark. Further, the reproduction amplitude of the reproduction waveform of the long mark can be made flat, and the amplitude of the shortest mark can be maximized.

Further, in this embodiment, a method of adjusting the position of the trailing edge of the reproduction waveform of the long mark by adjusting the power of the latter half pulse of the recording pulse is adopted. For this reason,
The position condition of the trailing edge of the recording pulse for recording the shortest mark is only one (that is, fixed). Further, the position condition of the trailing edge of the first half pulse and the position condition of the trailing edge of the second half pulse of the recording pulse for recording the long mark are each only one (that is, fixed). As a result, compared with the conventional recording method, the recording waveform (write strategy) is simplified, and the recording compensation parameter can be significantly reduced.

FIG. 1, FIG. 5, FIG. 6, FIG. 9, FIG.
With reference to FIG. 12 and FIG. 12, a description will be given of a method of obtaining a recording compensation condition by the shortest procedure in a test recording of a mark and a space, and a data recording / reproducing method. FIGS. 9, 10, 11 and 12 are flowcharts showing a method for obtaining the recording compensation condition in the shortest procedure and a data recording / reproducing method.

Referring to FIGS. 1 and 9, shortest mark 1
The recording pulse 101 for recording 08 will be described. The position 190 of the trailing edge of the recording pulse 101 is fixed to a position that satisfies a predetermined relative positional relationship with the edge of the recording clock (S1001). Next, the shortest mark 10
8 at the position of the trailing edge of the reproduced waveform (that is, the intersection 11
The power 12 of the recording pulse 101 is adjusted so that 2) is optimized.
2 is determined (S1002). Next, the shortest mark 108
Position of the leading edge of the reproduced waveform (i.e., intersection point 111)
The position 115 of the leading edge of the recording pulse 101 is determined based on the length of the space immediately before the shortest mark 108 (for example, 5T) (S1003). The position 115 of the leading edge of the recording pulse 101 can be adjusted to a different value each time the length of the immediately preceding space differs.

As described with reference to FIG. 5, it is desirable that the power 122 of the recording pulse 101 be determined to a value at which the reproduction amplitude 509 becomes maximum.

Referring to FIGS. 1 and 10, long mark 1
The recording pulse 172 for recording 29 will be described. First half pulse 1 of recording pulse 172 which is a two-stage pulse
06, the position 191 of the rear end edge is fixed to a position satisfying a predetermined relative positional relationship with the edge of the recording clock (S
1101). Next, the second half pulse 10 of the recording pulse 172
7 is fixed to a position satisfying a predetermined relative positional relationship with the edge of the recording clock (S1).
102). For example, the position of the trailing edge of the second half pulse in the recording pulse for recording a long mark of nTm (n is an integer of 4 or more) is (n−3) T from the trailing edge of the first half pulse. Fixed a minute later.

Next, the power 127 of the first half pulse 106 is determined (S1103). Power 127 is recording pulse 1
It may be determined to be equal to the power 122 of 01. Next, the second half pulse 10 is adjusted so that the position of the trailing edge of the reproduced waveform of the long mark 129 (that is, the intersection point 130) is optimized.
7 is determined (S1104). As described with reference to FIG. 6, in order to satisfy the flatness of the reproduction amplitude of the long mark, the power 122 and the power 1 shown in FIG.
26 and the power 127 may have different values, and the power 124 and the power 128 may have different values.

Next, the position 121 of the front edge of the first half pulse 106 is changed to the length of the space immediately before the long mark 129 (for example, so that the position of the front edge of the reproduced waveform of the long mark 129 (ie, the intersection 131) is optimized). 5T) and the length of the long mark 129 (for example, 5T) (S1105). The recording pulses 101 and 171 shown in FIG.
And 172 have different lengths of marks to be recorded, the lengths of the leading edge positions 115, 118, and 121 from the trailing edge are different even if the length of the immediately preceding space is the same. Can be set.

By repeatedly executing the procedure shown in FIGS. 9 and 10 for various combinations of the length of the mark and the length of the space, the recording compensation conditions for all the shortest marks and long marks are determined in the shortest procedure. You. FIG.
The order of the steps shown in FIG. 10 and FIG. 10 is an example, and is not limited to this order. The above is a method for obtaining the recording compensation condition in the test recording by the shortest procedure.

Next, a method for recording user data using the determined recording compensation conditions will be described with reference to FIGS. 1, 11 and 12. After the determination of the recording compensation condition, the trailing edge position 190 and the power 122 of the recording pulse 101 as the recording pulse for recording the mark shown in FIG. 1 have fixed values. Adjustment of the position 115 of the leading edge of the recording pulse 101 during user data recording is performed by selecting an appropriate position value from the recording compensation conditions as shown in FIG. 4A (S1201). The shortest mark 108 can be recorded on the optical disk by using the recording pulse 101 adjusted in this manner (S120).
2).

After the recording compensation conditions are determined, for example, in a recording pulse 172 as a recording pulse for recording the mark shown in FIG. 1, the positions 191 and 1 of the trailing edge of the first half pulse 106 and the second half pulse 107, respectively.
92 and the powers 127 and 128 have fixed values. The adjustment of the position 121 of the leading edge of the recording pulse 172 during user data recording is performed by selecting an appropriate position value from the recording compensation conditions as shown in FIG. 4A (S1301). Recording pulse 172 adjusted in this manner
Can be used to record the long mark 129 on the optical disc (S1302).

As described above, in the present embodiment, at the time of user data recording after the determination of the recording compensation condition, only one of the positions of the leading edge is selected and changed for the predetermined recording pulse. Since the processing is easy, the data recording operation can be speeded up.

(Embodiment 2) FIG. 2 is a diagram showing a data recording / reproducing method for an optical disk described as Embodiment 2 of the present invention, and a write pulse write strategy and a method of adjusting a recording compensation parameter in the data recording / reproducing method. It is. In the method shown in FIG. 2, the same parts as those in the first embodiment shown in FIG. 1 are denoted by the same reference numerals, and detailed description will be omitted.

FIGS. 2A to 2D show recording data, recording pulses, recording marks, and equalized reproduction signals when recording and reproducing the shortest mark of 3 Tm, respectively. FIG.
(H) shows recording data, a recording pulse, a recording mark, and an equalized reproduction signal when recording and reproducing the 4Tm long mark 125, respectively. 2 (i) to 2 (l) show recording data, recording pulses, recording marks, and an equalized reproduction signal when recording and reproducing a long mark 129 of 5 Tm or more, respectively.

Hereinafter, a recording / reproducing method and a method for adjusting a write strategy and a recording compensation parameter according to the second embodiment of the present invention will be described.

<First requirement> Length 3T shown in FIG.
In order to record the shortest mark 108 corresponding to the Hi-level signal 200 of FIG.
One recording pulse 201 which is a single pulse shown in FIG.

<Second Requirement> In order to record a long mark other than the shortest mark 108, for example, a long mark 125 corresponding to a 4T-length Hi level signal 202 shown in FIG. One recording pulse 241 which is a two-step pulse shown in FIG. The recording pulse 241 includes a first half pulse 203 and a second half pulse 204.

A long mark having a length of 5 Tm or more, for example, a Hi level signal 205 having a length of 5 T shown in FIG.
In order to record a long mark 129 corresponding to, one recording pulse 242 which is a two-step pulse shown in FIG. The recording pulse 242 is
A first half pulse 206 and a second half pulse 207 are included.

<Third Requirement> The power of a recording pulse for recording between marks (that is, a space) is changed for each length of a space so that edge fluctuation of a reproduced waveform of the mark due to thermal interference between marks is eliminated. A method for preventing the thermal interference between marks by lowering the recording power in the space portion and optimizing the position of the edge of the mark will be described with reference to FIG. FIG. 7 shows three types of relationships between the power of the recording pulse waveform of 8 Tm and the marks to be formed.

FIG. 7A shows a recording pulse 711 for recording a long mark 708 of 8 Tm and a space of 5 Ts.
And 145 are shown. FIG. 7B shows a long mark 708 and a space 755 recorded on the optical disc. In this case, since the space between marks is as large as 5 Ts, the rear end edge 701 of the long mark 708 is formed at an appropriate position without causing thermal interference.

FIG. 7C shows recording pulses when recording the long marks 709 and 710 of 8 Tm and the space of 3 Ts. In this case, since the space between marks is as small as 3 Ts, thermal interference occurs. As shown in FIG. 7D, the trailing edge 702 of the long mark 709 is gradually cooled due to thermal interference with the leading edge 703 of the next long mark 710 to be recorded, and an amorphous is hardly formed. Therefore, the trailing edge 702 moves forward in time. Further, the front edge 703 of the long mark 710 reaches a higher temperature due to the preheating effect of the thermal interference of the rear edge 702 of the previously recorded long mark 709, and the amorphous formation is promoted. Therefore, the front end edge 703 moves forward in time.

On the other hand, FIG. 7E shows recording pulses 711 and 213 when the power 260 for recording a space when the space between marks is small to prevent thermal interference is reduced. Recording pulse 2 in forming 3Ts
13 is applied with the power 260 lower than the power of the recording pulses 165 and 163, the thermal interference between the marks is canceled even when the space is short, and the rear end edge of the long mark 708 as shown in FIG. 705 and leading edge 70
6 are appropriate positions.

Referring to FIGS. 2A and 2B,
In order to record a space 154 having a length of 4T corresponding to the Lo level signal 210 with respect to the power 262 of the recording pulse 209 when recording a space 155 having a length of 5T or more corresponding to the Lo level signal 208 and causing no thermal interference. The power 261 of the recording pulse 211 is set smaller than the power 262. As a result, the power 261 becomes the power 262
In this case, it is possible to eliminate the influence of thermal interference between marks, which occurs slightly when the value is equal to or less than.

Length 3T corresponding to Lo level signal 212
The power 260 of the recording pulse 213 for recording the space 153 is set smaller than the power 261.
As a result, it is possible to eliminate the influence of thermal interference between marks which is largely generated when the power 260 is equal to the power 262.

That is, the power of the recording pulse for recording the space is determined for each length of the space, so that the influence of thermal interference between marks is eliminated. Note that the recording power of the recording pulse for each length of the space is constant regardless of the length of the marks before and after the space.

<Fourth Requirement> After the power of the recording pulse is determined for each space length, the recording pulse for recording the mark is adjusted so that the position of the leading edge of the reproduction waveform of the mark is optimized. The position of the leading edge is determined for each mark length.

In FIG. 2, the shortest mark 108 of 3 Tm
Of the recording pulse 201 so that the position of the leading edge of the reproduced waveform (i.e., the intersection 214 between the equalized reproduced signal 250 and the slice level 110) is optimized.
15 is determined. The position 217 of the leading edge of the first half pulse 203 of the recording pulse 241 is changed so that the position of the leading edge of the reproduced waveform of the 4Tm long mark 125 (ie, the intersection 216 between the equalized reproduced signal 251 and the slice level 110) is optimized. decide. The position of the leading edge of the reproduced waveform of the long mark of 5 Tm or more (that is, the equalized reproduced signal 252
The position 219 of the leading edge of the first half pulse 206 of the recording pulse 242 is determined so that the intersection point 218) between the recording pulse 242 and the slice level 110 is optimized.

<Fifth Requirement> Similarly to the above, after determining the power of the recording pulse for each length of the space, the position of the trailing edge of the reproduction waveform of the mark is adjusted so that the position of the trailing edge is adjusted. The position of the end edge is determined for each mark length.

In FIG. 2, the shortest mark 108 of 3 Tm
Is determined so that the position of the trailing edge of the reproduced waveform (i.e., the intersection 220 between the equalized playback signal 250 and the slice level 110) is optimized. The position of the trailing edge of the latter half pulse 204 of the recording pulse 241 so that the position of the trailing edge of the playback waveform of the 4Tm long mark 125 (ie, the intersection 222 between the equalized playback signal 251 and the slice level 110) is optimized. 2
23 is determined. The trailing edge of the second half pulse 207 of the recording pulse 242 is adjusted so that the position of the trailing edge of the playback waveform of the long mark 129 of 5 Tm or more (ie, the intersection 224 between the equalized playback signal 252 and the slice level 110) is optimized. Determine the position 225.

FIG. 4C shows the position conditions of the edge of the recording pulse. The numbers in the table shown in FIG. 4C correspond to the reference numerals indicating the positions of the respective parts shown in FIG. The position of each part corresponding to each reference symbol shown in the table is not necessarily different from each other, and some positions may have the same value depending on the recording film characteristics and equalizer characteristics of the optical disc. is there.

As in the first embodiment, the power of a single pulse for recording the shortest mark and the positions of the leading edge and the trailing edge are the same as in the first embodiment.
In the presence of a plurality of combinations in which the position of the edge of the reproduction waveform of the shortest mark is optimized, it is preferable to select a condition that maximizes the reproduction amplitude.

When a long mark is recorded, the power of the first half pulse and the position of the front end edge, and the power of the second half pulse and the position of the rear end edge are adjusted to the positions of the edges of the reproduced waveform of the long mark. In the presence of a plurality of combinations, it is preferable to select a condition under which the reproduction amplitudes at the front and rear ends of the long mark become the same (that is, the reproduction waveform becomes flat).

In FIG. 2, the power 227 of the first half pulse 203 of the recording pulse 241 and the power 228 of the first half pulse 206 of the recording pulse 242 are made the same as the power 226 of the recording pulse 201, and the power 229 of the second half pulse 204 of the recording pulse 241 is changed. FIG. 4D shows the power condition of the recording pulse when the power 230 of the latter half pulse 207 of the recording pulse 242 is constant regardless of the mark length. Also, the power condition of the recording pulse for each space length is shown. The numbers described in the table shown in FIG. 4D correspond to the reference numerals indicating the powers of the respective units shown in FIG.

As described above, according to the recording / reproducing method satisfying the first to fifth requirements, all the marks from the shortest mark to the longest mark are recorded on the optical disk, and the reproduction waveform of the optimized mark is obtained. Edge positions are achieved. Note that the above first to fifth requirements are merely in the order of description, and the order of execution may be changed.

The recording / reproducing method of the optical disk according to the present embodiment does not use a pulse shorter than the recording clock cycle to record a long mark unlike the conventional method. Also,
Since the influence of the thermal interference between marks was eliminated by controlling the power of the recording pulse for recording the space, the position conditions of the leading edge and the trailing edge of the recording pulse were one-dimensional parameters for each length of the mark itself. Further, it is possible to equalize the amplitudes at the front and rear ends of the reproduction waveform of the long mark and maximize the amplitude of the reproduction waveform of the shortest mark. That is, as compared with the conventional recording method, the waveform (write strategy) of the recording pulse is simplified, and the recording compensation parameter can be greatly reduced.

FIGS. 2, 7, 13, 14, and 15
With reference to, a description will be given of a method of obtaining the recording compensation condition by the shortest procedure in the test recording of the mark and the space, and a data recording / reproducing method. 13, 14 and 15
5 is a flowchart showing a method for obtaining a recording compensation condition in the shortest procedure and a data recording / reproducing method.

The recording pulse 201 for recording the shortest mark 108 will be described with reference to FIGS. The position 221 of the trailing edge of the recording pulse 201 is
It is fixed at a position that satisfies a predetermined relative positional relationship with the edge of the recording clock (S1401). Next, the shortest mark 1
08 at the position of the trailing edge of the reproduced waveform (that is, at the intersection 22
0) of the recording pulse 201 so that
6 is determined (S1402). Next, the position 215 of the front edge of the recording pulse 201 is determined so that the position of the front edge of the reproduction waveform of the shortest mark 108 (that is, the intersection point 214) is optimized (S1403). Next, the recording pulses 213, 211, and 209 for recording the spaces 153, 154, and 155 so as to eliminate the position fluctuation of the edge of the reproduction waveform of the mark due to thermal interference between the marks.
Is determined based on the length of each of the spaces 153, 154 and 155 (S1404). Thus, even if the length of the space immediately before the shortest mark 108 is different, without changing the value of the front end edge position 215 of the recording pulse 201, the positions of the front and rear end edges of the reproduced waveform of the shortest mark 108 (that is, the intersections 214 and 220) can be optimized.

Referring to FIGS. 2 and 14, long mark 1
The recording pulse 242 for recording 29 will be described. The position 291 of the trailing edge of the first half pulse 206 is fixed to a position satisfying a predetermined relative positional relationship with the edge of the recording clock (S1501). Next, the first half pulse 206
Is determined (S1502). Power 22
8 may be determined to be equal to the power 226 of the recording pulse 201.

Next, the position of the trailing edge of the reproduced waveform of the long mark 129 (that is, the intersection 224) is optimized (for example, to satisfy the flatness of the reproduced amplitude of the long mark 129). The position 225 of the trailing edge and the power 230 are determined based on the length of the long mark 129 (S1503). For example, the position of the trailing edge of the second half pulse in the recording pulse for recording a long mark of nTm (n is an integer of 4 or more) is (n−3) T from the trailing edge of the first half pulse. Fixed a minute later,
This fixed position can be further fine-tuned.

Next, the position 219 of the leading edge of the first half pulse 206 is determined based on the length of the long mark 129 so that the position of the leading edge of the reproduced waveform of the long mark 129 (that is, the intersection point 218) is optimized. (S1504).
Next, the spaces 153, 154, and 155 determine the power of the recording pulse for recording the space based on the length of the space so that the position fluctuation of the edge of the reproduction waveform of the mark due to the thermal interference between the marks is eliminated. The power of the recording pulses 213, 211, and 209 for recording is determined based on the length of each of the spaces 153, 154, and 155 (S1505). S1505 is S140
4 and can be common.

By repeatedly executing the procedure shown in FIGS. 13 and 14 for various combinations of the length of the mark and the length of the space, the recording compensation conditions for all the shortest marks, long marks and spaces are determined in the shortest procedure. It is determined. The order of the steps shown in FIGS. 13 and 14 is an example, and is not limited to this order. The above is a method for obtaining the recording compensation condition in the test recording by the shortest procedure.

Next, a method for recording user data using the determined recording compensation conditions will be described with reference to FIGS. After the recording compensation condition is determined, for example, the leading edge position 215, the trailing edge position 221 and the power 226 of the recording pulse 201 as the recording pulse for recording the mark shown in FIG. 2 have fixed values. Adjustment of the power of the recording pulse for recording the space at the time of recording the user data is performed by selecting an appropriate power value from the recording compensation conditions as shown in FIG. 4D (S1601). Recording pulse 20 adjusted in this way
Spaces 155, 15 using 9, 211 and 213
4 and 153 can be recorded on the optical disc (S1602).

As described above, in the present embodiment, when user data is recorded after the recording compensation condition is determined, there is no recording pulse element to be selected or changed according to the conditions before and after the recording pulse irradiation, and data processing is easy. Therefore, the data recording operation can be speeded up.

(Embodiment 3) FIG. 8 is a diagram showing a data recording / reproducing method of an optical disk described as Embodiment 3 of the present invention and a method of adjusting a waveform (write strategy) of a recording pulse in the data recording / reproducing method. is there. FIG.
(A) shows recording pulses 810 and 817 for recording a long mark and a shortest mark by a recording method similar to that of the first or second embodiment. FIG. 8B
Indicates a long mark 803 and a shortest mark 800 recorded by the recording pulses 810 and 817. The recording pulse in the recording / reproducing method of the present invention can be implemented even in a state where a preheating pulse and a cooling pulse described below are added, and the effect is exhibited.

FIG. 8C shows a preheating pulse 802 at the end position of a recording pulse 801 for forming a space 812.
Is shown in the embodiment. Since the preheating pulse 802 helps increase the temperature of the front end portion 800 of the shortest mark 821, an amorphous state is easily formed at the front end portion 800.

FIG. 8D shows that the cooling pulse 805 is located at the start position of the recording pulse 804 for forming the space 812.
Is shown in the embodiment. Since the cooling pulse 805 increases the cooling rate of the rear end 803 of the long mark 820, amorphous is easily formed on the rear end 803.

FIG. 8E shows preheating pulses 805 at both ends of a recording pulse 806 for forming a space 812.
And an embodiment in which both the cooling pulse 802 and the cooling pulse 802 are added.
Both pulses further facilitate amorphization at the front end 800 and the rear end 803.

The write pulse write strategy and the method of adjusting the recording compensation parameters in the recording / reproducing method of the present invention may be performed before the product is shipped from the recording / reproducing apparatus.
Also, it may be carried out every time the user uses the recording / reproducing apparatus.

[0112]

According to the data recording / reproducing method for an optical disk of the present invention, since a narrow multi-pulse is not used, it is easy to increase the recording rate and control the power during recording. Further, the amplitude of the shortest mark in high-density recording can be maximized, and distortion of a long mark can be reduced. In addition, a write strategy and recording compensation with fewer parameters than before can be realized. Therefore, the present invention is most suitable for an optical disk system that requires high speed and high density, such as a digital video recorder.

[Brief description of the drawings]

FIG. 1 is a diagram showing a data recording / reproducing method for an optical disc according to Embodiment 1 of the present invention.

FIG. 2 is a diagram showing a data recording / reproducing method for an optical disc according to Embodiment 2 of the present invention.

FIG. 3 is a diagram showing a data recording / reproducing apparatus for an optical disc according to an embodiment of the present invention.

FIG. 4A is a diagram showing recording compensation conditions in a data recording / reproducing method for an optical disc in the embodiment of the present invention.

FIG. 4B is a diagram showing a recording compensation condition of the data recording / reproducing method for the optical disc in the embodiment of the present invention.

FIG. 4C is a diagram showing a recording compensation condition of the data recording / reproducing method for the optical disc in the embodiment of the present invention.

FIG. 4D is a diagram showing a recording compensation condition of the data recording / reproducing method for the optical disc in the embodiment of the present invention.

FIG. 5 is a diagram showing a recording / reproducing method of a shortest mark according to the first embodiment of the present invention.

FIG. 6 is a diagram showing a recording / reproducing method of a long mark according to the first embodiment of the present invention.

FIG. 7 is a diagram showing a recording method for controlling thermal interference between marks according to the second embodiment of the present invention.

FIG. 8 is a diagram showing a data recording / reproducing method for an optical disc according to Embodiment 3 of the present invention.

FIG. 9 is a flowchart showing a data recording / reproducing method for an optical disc according to Embodiment 1 of the present invention.

FIG. 10 is a flowchart showing a data recording / reproducing method for an optical disc in Embodiment 1 of the present invention.

FIG. 11 is a flowchart showing a data recording / reproducing method for an optical disc according to Embodiment 1 of the present invention.

FIG. 12 is a flowchart showing a data recording / reproducing method for an optical disc in the first embodiment of the present invention.

FIG. 13 is a flowchart showing a data recording / reproducing method for an optical disc in Embodiment 2 of the present invention.

FIG. 14 is a flowchart showing a data recording / reproducing method for an optical disc according to Embodiment 2 of the present invention.

FIG. 15 is a flowchart showing a data recording / reproducing method for an optical disc in Embodiment 2 of the present invention.

FIG. 16 is a diagram showing a conventional data recording method.

FIG. 17A is a diagram showing recording compensation conditions in a conventional data recording / reproducing method for an optical disk.

FIG. 17B is a diagram showing recording compensation conditions in a conventional data recording / reproducing method for an optical disk.

[Explanation of symbols]

 Reference Signs List 101 single pulse 103 first half pulse 104 second half pulse 108 shortest mark 111 front edge of mark reproduction waveform 112 rear edge of mark reproduction waveform 115 front edge of single pulse 118 front edge of first half pulse 122 power of single pulse 124 Power of second half pulse 125 Long mark 126 Power of first half pulse

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5D090 AA01 BB05 CC02 DD03 DD05 EE02 FF21 KK04 KK05 5D119 AA23 AA24 BA01 BB04 DA02 HA47 HA48 HA49 HA50 HA60

Claims (13)

[Claims] 1. A method for adjusting a recording pulse for recording a mark on an optical disk, comprising: (a) adjusting a first recording pulse for recording a shortest mark; and (b) recording a long mark. Adjusting the second recording pulse for performing the first and second recording pulses, wherein the first recording pulse is a single pulse having a first power, and the second recording pulse is a first half pulse having a second power and a third pulse. A two-stage pulse including a second half pulse having power, wherein the step (a) comprises: (a1) determining a position of a rear end edge of the first recording pulse;
Fixing the position to satisfy a predetermined relative positional relationship with the first edge of the recording clock; and (a2) determining the first power so that the position of the trailing edge of the reproduction waveform of the shortest mark is optimized. (A3) determining the position of the front edge of the first recording pulse based on the length of the space immediately before the shortest mark so that the position of the front end of the reproduction waveform of the shortest mark is optimized. (B1) fixing the position of the trailing edge of the first half pulse to a position that satisfies the predetermined relative positional relationship with the second edge of the recording clock. (B2) fixing the position of the trailing edge of the latter half pulse to a position satisfying the predetermined relative positional relationship with the third edge of the recording clock; 3) determining the second power; (b4) determining the third power such that the position of the trailing edge of the reproduction waveform of the long mark is optimized; and (b5) determining the length of the long mark. Determining the position of the leading edge of the first half pulse based on the length of the space immediately before the long mark and the length of the long mark so that the position of the leading edge of the reproduced waveform is optimized. . 2. The combination of the first power and the position of the leading edge of the first recording pulse is such that the position of the leading edge and the position of the trailing edge of the reproduction waveform of the shortest mark are optimized. 2. The method according to claim 1, wherein a combination in which the reproduction amplitude of the shortest mark is substantially maximized is set among a plurality of combinations. 3. The combination of the second power, the third power, and the position of the leading edge of the first half pulse,
Among a plurality of combinations in which the position of the front end edge and the position of the rear end edge of the reproduction waveform of the long mark are optimized, the combination is such that the reproduction amplitude of the long mark is substantially flat, The method for adjusting a recording pulse according to claim 1. 4. The method according to claim 1, wherein the first power and the second power have the same magnitude. 5. The recording pulse according to claim 1, wherein the position of the trailing edge of the second half pulse is fixed at a position after a predetermined clock cycle from the position of the trailing edge of the first half pulse. how to. 6. A method for recording a mark on an optical disk using the method for adjusting a recording pulse according to claim 1, wherein the mark is recorded based on the first recording pulse adjusted at least according to the step (a). A method of recording a mark on an optical disc, comprising: recording a shortest mark; and recording the long mark based on the second recording pulse adjusted at least according to the step (b). 7. A method of recording a mark on an optical disc, comprising: (a) a front end of a first recording pulse for recording a shortest mark, which is a single pulse having a fixed position of a rear end edge and a fixed power; Adjusting the edge based on the length of the space immediately before the shortest mark; (b) recording the shortest mark using the first recording pulse adjusted in the step (a); (c) A two-stage pulse including a first half pulse and a second half pulse having different powers, and a long mark having a predetermined length in which the position and the power of the rear edge of each of the first half pulse and the second half pulse are fixed. Adjusting the leading edge of the second recording pulse for recording based on the length of the space immediately before the long mark; and (d) adjusting the leading edge of the second recording pulse before the adjustment in step (c). Comprising the step of recording the length mark using the second recording pulse, the method. 8. A method for adjusting a recording pulse for recording a mark and a space on an optical disk, comprising: (a) adjusting a first recording pulse for recording a shortest mark; Adjusting a second recording pulse for recording a mark; and (c) adjusting a third recording pulse for recording a space between the marks, wherein the first recording pulse has a first power. The second recording pulse is a two-step pulse including a first half pulse having a second power and a second half pulse having a third power, and the third recording pulse has a fourth power. The step (a) includes: (a1) determining a position of a trailing edge of the first recording pulse;
Fixing the position to satisfy a predetermined relative positional relationship with the first edge of the recording clock; and (a2) determining the first power so that the position of the trailing edge of the reproduction waveform of the shortest mark is optimized. (A3) determining the position of the leading edge of the first recording pulse so that the position of the leading edge of the reproduction waveform of the shortest mark is optimized; and the step (b). (B1) fixing the position of the trailing edge of the first half pulse to a position that satisfies the predetermined relative positional relationship with the second edge of the recording clock; and (b2) determining the second power. (B3) changing the position of the trailing edge of the second half pulse and the third power so that the position of the trailing edge of the reproduction waveform of the long mark is optimized. (B4) determining the position of the leading edge of the first half pulse based on the length of the long mark so that the position of the leading edge of the reproduced waveform of the long mark is optimized. And (c1) determining the fourth power based on the length of the space so that the position of the edge of the reproduction waveform of the mark due to thermal interference between the marks does not fluctuate. A method comprising the steps of: 9. The combination of the first power and the position of the leading edge of the first recording pulse is such that the position of the leading edge and the position of the trailing edge of the reproduction waveform of the shortest mark are optimized. The method for adjusting a recording pulse according to claim 8, wherein a combination in which the reproduction amplitude of the shortest mark is substantially maximized among a plurality of combinations to be performed. 10. The combination of the second power, the third power, and the position of the front edge of the first half pulse is determined by the position of the front edge and the position of the rear edge of the reproduction waveform of the long mark. The method for adjusting a recording pulse according to claim 8, wherein, among a plurality of combinations optimized by the above, the combination is such that the reproduction amplitude of the long mark is substantially flat. 11. The method according to claim 8, wherein the first power and the second power have the same magnitude. 12. A method for recording a mark on an optical disc using the method for adjusting a recording pulse according to claim 8, wherein the mark is recorded on the basis of the first recording pulse adjusted at least according to the step (a). Recording the shortest mark; recording the long mark based on the second recording pulse adjusted at least according to the step (b); and the third recording pulse adjusted at least according to the step (c) Recording the space based on the method. 13. A method for recording a space between marks on an optical disk, comprising: (a) a single recording method for recording a space so as to eliminate a positional change of an edge of a reproduction waveform of a mark due to thermal interference between the marks; Adjusting the power of the recording pulse, which is a pulse, based on the length of the space; and (b) recording the space using the recording pulse adjusted in the step (a). Method.