JPH07225949A - Optical disk device - Google Patents

Abstract

PURPOSE:To suppress the degradation of an information recording medium and also to reproduce data from a mark recorded by shifting the mark positions of writing data in an optical disk device. CONSTITUTION:At the time of a recording, a recording clock signal 211 which is obtained by delaying a reference clock signal 123 with recording clock forming means 124, 137 is formed and recording control means 127, 128 transfer user data to an optical head 104 by synchronizing with the signal 211 and the user data are recorded on an optical disk medium 101 and simultaneously a delay quantity is also recorded on the optical disk medium 101. At the time of a reproducing, the delay quantity is read out of the optical disk medium 101 and reproducing clock forming means 124, 137 delay the reference clock 123 by a delay quantity 317 to form a reproduced clock signal 311 and then the user data are reproduced by synchronizing a signal read out by the optical head 104 with the signal 311.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disk device in which the recording / reproducing position of a rewritable optical disk is controlled.

[0002]

2. Description of the Related Art Conventionally, phase change rewritable optical recording media are
A high level laser beam is emitted during writing, and a medium level laser beam is emitted during erasing. However,
If the writing and erasing of the data of the same content are repeated, the same portion of the medium is repeatedly irradiated with the laser beam, and the medium in that portion deteriorates, resulting in a decrease in reproduction sensitivity.

In order to solve this problem, Japanese Patent Laid-Open No. 3-1
Japanese Patent No. 50725 proposes a method of adjusting the time of a write data signal to shift the data write location, suppress deterioration of the information recording medium, and improve repeatability.

[0004]

However, the above-mentioned Japanese Patent Laid-Open No. 3-150725 discloses that the data writing position is shifted, but regarding how to read the shifted and written data, Not disclosed. Therefore, when the method described in Japanese Patent Laid-Open No. 3-150725 is applied to a rewritable optical recording medium, it is impossible to reproduce recorded data. In particular, in the case of using a system in which a reference clock is formed based on a reference position previously formatted on the medium and recording or reproducing is performed in synchronization with the reference clock, as in a sample servo format information recording medium. However, if the data is written with being shifted, the reproduced signal cannot be reproduced because the reproduced signal is not synchronized with the reference clock.

It is an object of the present invention to provide an optical disk device capable of realizing recording, reproduction and erasing while shifting the position of write data in order to suppress deterioration of the information recording medium.

[0006]

An optical disk device according to the present invention represents a recording medium having a region in which a mark representing a reference position data for forming a reference clock signal is formed in advance, and the data is represented on the recording medium. An optical head for recording / reproducing a mark, a reference clock signal forming means for forming a reference clock signal from a mark signal representing the reference position data reproduced by the optical head, and data to be recorded in the optical head. Recording control means for transmitting and receiving the signal represented in synchronism with a clock signal, and reproduction control means for reading out data by synchronizing the signal reproduced by the optical head with the clock signal are provided.

To achieve the above object, the recording clock forming means for forming a clock signal used by the recording control means by further delaying the reference clock signal, and the amount delayed by the recording clock delay means. And a reproduction clock forming means for forming a clock signal used by the reproduction control means by reading the delay amount recorded in the storage means and delaying the reference clock signal by the delay amount. It is a thing.

[0008]

In the optical disk device of the present invention, the optical head is
The mark representing the reference position data recorded in advance on the recording medium and the mark representing the data to be recorded on the recording medium are recorded and reproduced. The reference clock signal forming means forms a reference clock signal from the signal of the mark representing the reference position data read by the optical head.
Further, the recording control means delivers a signal representing the data to be recorded to the optical head in synchronization with the clock signal and records it on the recording medium. The reproduction control means reads the data by synchronizing the signal reproduced by the optical head and the clock signal.

The clock signal used by the recording control means is formed by the recording clock forming means by delaying the reference clock signal.

At this time, the amount to be delayed from the reference clock signal is determined by selecting one of the predetermined amounts or by generating a numerical value representing the amount using a random number or the like. Is possible. Since the recording control means uses a signal delayed from the reference clock signal as the clock signal, the position of the mark formed on the optical disc is displaced according to this delay amount. Therefore, even when the same data is repeatedly recorded, the mark position shifts due to the delay amount of the clock signal, so that deterioration due to repeated irradiation of the laser beam on the same portion of the recording medium can be prevented.

The amount by which the recording clock forming means delays the reference clock signal is recorded in the storage means.

When reproducing the data of the mark written on the optical disk, the reproduction clock forming means reads the delay amount recorded in the storage means to obtain the delay amount when the mark is recorded. The clock signal used for reproduction is formed by delaying the reference clock by the same amount as this delay amount. By using this clock signal, the reproduction control means can reproduce the data from the mark formed at the position shifted at the time of recording.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an optical disk device of the present invention will be described below with reference to the drawings.

First, the configuration of the optical disk device of this embodiment will be described with reference to FIG.

As shown in FIG. 1, the optical disk device of this embodiment comprises a phase change rewritable optical disk medium 101, which is supported by a supporting portion 601. Support part 601
Is connected to a spindle motor 102, and the spindle motor 102 drives the optical disk medium 101 at 3600 sec.
It is driven to rotate at the speed of rotation. A rotation speed control unit 103 is connected to the spindle motor 102 and controls the rotation speed of the spindle motor 102.

The optical disk medium 101 has a radius of 2.5 inches and a recording / reproducing area of 30 to 60 mmφ. Also,
The optical disk medium 101 has recording / reproducing tracks in a spiral shape, and CAV (ConstantAn) in which 688 servo marks (radially with respect to the center of the optical disk medium 101) per track exist on the recording / reproducing track.
It is pre-formatted according to the Gluular Velocity method. The track interval is 1.5 μm.

An optical head 104 for recording / reproducing information on / from the optical disc medium 101 is arranged on the lower surface side of the optical disc medium 101. This optical head 1
Reference numeral 04 denotes a semiconductor laser light source having a wavelength of 780 nm, an optical system including an objective lens with a numerical aperture of 0.55 that focuses the laser light on the optical disc medium, a photodetector for detecting the amount of reflected light from the optical disc medium 101 by the laser irradiation light,
A tracking actuator that drives the objective lens in the radial direction of the optical disc medium in order to make the irradiation position of the laser beam follow the track, and an objective lens of the laser beam in order to make the focal position of the laser beam follow the surface of the optical disc medium. It has a built-in focus actuator that drives in the optical axis direction. Further, the optical head 104 includes the optical head 1
A course actuator 112 for moving 04 in the radial direction of the optical disc medium 101 is attached.

A preamplifier 120 and a laser driver 128 are connected to the optical head 104.

The preamplifier 120 includes an optical disk medium 1
A clock pit detection circuit 121 for extracting a reproduction signal waveform corresponding to a clock pit formed in the servo mark on 01, and 1 based on the timing of the clock pit.
PLL that generates the 1.2 MHz reference clock 123
A (Phase Locked Loop) 122 and a variable delay device 124 that delays the reference clock signal 123 by a set time are sequentially connected. On the other hand, a discriminator 125, a demodulator 126, an error corrector 129, and a delay amount demodulator 132 are connected to the preamplifier 120. The discriminator 125 discriminates the output of the preamplifier 120 according to the discrimination timing according to the reproduction clock signal 211 output from the variable delay device 124, and the detection signal sequence 325.
Is output. The demodulator 126 reproduces information (user data) in the user data area from the detection signal sequence 325 and the reproduction clock signal 211. The error corrector 129 corrects the error of the user data demodulated by the demodulator 126. Further, the delay amount demodulator 132 demodulates the delay set value from the detection signal sequence 325 output from the discriminator 125 and the reproduced clock signal 211.

The laser driver 128 is connected to a modulator 127 that generates a recording command signal 219 for user data and a delay amount modulator 133 that generates a recording command signal 219 for the delay amount recording mark 501. .

The variable delay unit 124, the error corrector 129, the delay amount demodulator 132, and the delay amount modulator 133.
A controller 134 is connected to and. The controller 134 includes an I / F (interface) controller 1
39, file management unit 131, random number generation unit 135, delay amount management unit 136, delay amount setting unit 137, mechanism system control unit 1
38 are provided. Each of these units includes a memory that stores a program and an arithmetic unit (not shown) that reads and operates the program, and operates as follows. I / F
The (interface) control unit 139 controls the controller 13
4 controls an interface for inputting / outputting user data to / from an external host computer connected to No. 4. The file management unit 131 outputs the user data received from the host computer via the I / F (interface) control unit 139 to the error corrector 129 during recording and receives the user data from the error corrector 129 during reproduction. , I / F (interface) controller 1
The host computer is delivered via 39. The random number generator 135 generates a random number used to determine the delay amount 217. The delay amount management unit 136 determines the delay amount 217 for writing the user data. The delay amount setting unit 137 sets the delay amount 217 in the variable delay device 124. The mechanical system controller 138 controls mechanical operations of the optical head 104, the course actuator 112, and the spindle motor 102. Further, the controller 134 has an I
A / F (interface) control unit 139, a file management unit 131, a random number generation unit 135, a delay amount management unit 136, a delay amount setting unit 137, and a control unit 602 for instructing the mechanical system control unit 138 to operate are further provided. ing. Control unit 6
Reference numeral 02 has a memory (not shown) that stores a program and an arithmetic unit (not shown) that reads and operates the program. Then, the control unit 602 controls the optical disc medium 10
When an instruction is received from the host computer to record, reproduce, and erase the user data in 1, the recording, reproducing, and erasing operations are performed by sequentially instructing the above-mentioned units to operate.

The operation of the optical disk device of this embodiment will be described.

First, with reference to FIGS. 1, 2, 4, 5, 6, and 7, the operation for recording user data by using the optical disk device of this embodiment will be described.

Recording track 21 of the optical disc medium 101
As shown in FIGS. 2 and 4, servo mark areas 221 and user data areas 220 are alternately present on the area 3. In the servo mark area 221, the reference clock signal 1
The clock pits 214 used to generate 23 and the focus position of the laser light of the optical head 104 are recorded on the recording track 213.
The wobble pits 218 used to follow the center of the are formed (preformatted) in advance. In the present embodiment, since the recording marks 216 to be recorded in the user data area 220 are formed with a maximum shift of 45 ns, the user data area 220 needs to be larger than normal by 45 ns. For this reason, in the present embodiment, the servo mark area 221 is removed by 45 ns, and the margin up to the servo mark area where user data is not conventionally recorded is used as the user data area 220.

The control section of the controller 134 stores a recording program in the memory as shown in the flowchart of FIG.
By operating the other control unit in 4, the user data is recorded at a position deviated from the position where the recording mark 216 of the previous user data was formed.

First, the control unit 602 is the mechanical system control unit 13.
8 is instructed to operate. The mechanical system control unit 138 instructs the optical head 104 to perform the reproducing operation of the servo mark area 221. The amount of light reflected from the optical disc medium 101 is converted into an electric signal by the photodetector in the optical head 104 and amplified by the preamplifier 120. The reproduction signal waveform corresponding to the clock pit 214 formed in the servo mark area 221 on the optical disk medium is extracted by the clock pit detector 121, and the PLL 122 divides the timing to perform the 11.2 MHz reference clock signal 123. To generate.

Next, the control unit 602 controls the random number generation unit 135.
And the delay amount management unit 136 are instructed to operate. The random number generator 135 randomly generates any one of the numbers 0 to 9 and uses this number as the delay set value to determine the delay amount management unit 1.
Output to 36. The delay amount management unit 136 outputs the delay set value to the delay amount modulator 133 (step 701).

Further, the control unit 602 includes a delay amount setting unit 1
Instruct the operation of 37 and the delay amount = 0 to 37. The delay amount setting unit 137 sets the delay amount = 0 in the variable delay device 124. As a result, the variable delay device 124 outputs the reference clock signal 123 as it is.

The delay amount modulator 133 has a built-in table showing the relationship between the delay set value and the delay amount recording data 1001 shown in FIG. The delay amount modulator 133 generates the delay amount recording data 1001 corresponding to the delay setting value received from the delay amount managing unit 136, and synchronizes the delay amount recording data 1001 with the reference clock signal 12 to record the delay amount. Recording command signal 2 representing data 1001
19 (step 702), and the laser driver 12
Output to 8.

The laser driver 128 controls the output of the semiconductor laser in the optical head 104 based on the recording command signal 219 for recording the delay amount recording mark 501. The control unit 602 also controls the mechanical system control unit 138 to control the position of the optical head 104 and the rotation of the optical disc medium 101. As a result, the optical disc medium 101 of FIG.
The delay amount recording mark 501 as shown in FIG. 5 is formed in the delay amount recording area 404 (step 703).

Next, the control unit 602 controls the delay amount management unit 1
36 and the delay amount setting unit 137 are instructed to operate. The delay amount management unit 136 has a built-in table showing the relationship between the delay set value and the delay amount shown in FIG.
The delay amount corresponding to the delay setting value received from No. 5 is output to the delay amount setting unit 137. The delay amount setting unit 137 sets the delay amount 217 in the variable delay device 124 (step 70).
4).

The variable delay unit 124 controls the reference clock signal 1
The recording clock signal 211 obtained by delaying 23 by the set delay amount 217 is output to the modulator 127. Control unit 60
2 instructs the file management unit 131 to operate. The file management unit 131 outputs the user data to the error corrector 129. The error corrector 129 adds error correction information to the user data, performs parallel-serial conversion, and outputs the recording code string 212 to the modulator 127.
The modulator 127 synchronizes the recording code string 212 with the recording clock signal 211 and records the user data recording command signal 219.
Is generated and output to the laser driver 128 (step 705). As a result, the user data recording command signal 219 synchronized with the recording clock signal 211 delayed from the reference clock signal by the delay amount 217 is generated.

The laser driver 128 controls the output of the semiconductor laser in the optical head 104 based on the user data recording command signal 219. In addition, the control unit 602
The mechanical control unit 138 controls the position of the optical head 104 and the rotation of the optical disc medium 101. As a result, the user data area 220 of the optical disc medium 101 of FIG.
A recording mark 216 as shown in FIG.

Next, FIG. 1, FIG. 3, FIG. 4, FIG.
The operation when reproducing user data by using the optical disk device of this embodiment will be described with reference to FIG.

The control unit 602 of the controller 134 stores a reproduction program as shown in the flowchart of FIG. 8 in the memory, and in accordance with this, another control unit in the controller 134 is operated to operate as described above. As described above, the recording mark 216 representing the user data recorded at the position deviated from the reference clock is reproduced.

First, the control unit 602 is the mechanical system control unit 13.
8 is instructed to operate. The mechanical system control unit 138 operates the optical head 104, the spindle motor 102, and the course actuator to cause the optical head 104 to reproduce the mark in the servo mark area. The amount of light reflected from the optical disc medium 101 is converted into an electric signal by the photodetector in the optical head 104 and amplified by the preamplifier 120. The reproduction signal waveform corresponding to the clock pit 214 formed in the servo mark area 221 on the optical disk medium is extracted by the clock pit detector 121, and the PLL
122 divides the timing and performs 11.2 MH
The z reference clock signal 123 is generated.

Next, the control unit 602 controls the delay amount setting unit 1
An instruction for operation and an instruction for delay amount = 0 are given to 37. The delay amount setting unit 137 sets the delay amount = 0 in the variable delay device 124. As a result, the variable delay unit 124 outputs the reference clock signal 123 as it is to the discriminator 125 as the reproduced clock signal 311.

The control unit 602 instructs the mechanical system control unit 138 to operate. The mechanical system control unit 138 uses the optical head 104.
And spindle motor 102 and course actuator 1
12 is operated, and the delay amount recording area 40 is added to the optical head 104.
The delay amount recording mark 216 of 4 is detected (step 6
01).

The amount of light reflected from the optical disc medium 101 is
It is converted into an electric signal by a photo detector in the optical head 104, amplified by the preamplifier 120, and output to the discriminator 125. The discriminator 125 compares the reproduction signal representing the delay amount recording data 1001 in the delay amount recording area 404 with the discrimination level 321 at the discrimination timing 322 corresponding to the reproduction clock signal 311 which is the reference clock signal 123, and the comparison result. Accordingly, the detection signal sequence 325 representing the delay amount recording data 1001 is output to the delay amount demodulator 132.

The delay amount demodulator 132 has a built-in table showing the relationship between the delay set value and the delay amount recording data 1001 shown in FIG. The delay amount demodulator 132 obtains a delay setting value corresponding to the detection signal sequence 325 representing the delay amount recording data 1001 and outputs it to the delay amount management unit 136.

The control unit 602 instructs the delay amount management unit 136 and the delay amount setting unit 137 to operate. Delay amount management unit 1
As already described, 36 has a built-in table showing the relationship between the delay amount set value and the delay amount shown in FIG. 6, and calculates the delay amount corresponding to the delay amount set value received from the delay amount demodulator 132. , To the delay amount setting unit 137 (step 802). The delay amount setting unit sets the delay amount received from the delay amount management unit 136 as the reproduction delay amount 317 in the variable delay unit 124 (step 803). Variable delay device 12
4 outputs the reproduction clock signal 311 obtained by delaying the reference clock signal 123 by the reproduction delay amount 317 to the discriminator 125 and the demodulator 126.

The control unit 602 instructs the mechanical system control unit 138 to operate. The mechanical system control unit 138 uses the optical head 104.
The spindle motor 102 and the course actuator are operated to cause the optical head 104 to reproduce the user data area 221 and the mark 216 in the error correction information recording area 403. The amount of light reflected from the optical disc medium 101 is converted into an electric signal by the photodetector in the optical head 104, amplified by the preamplifier 120, and then discriminated by the discriminator 125.
Is output to.

The discriminator 125 has a user data area 221.
Then, the reproduction signal of the error correction information recording area 403 is discriminated at the discrimination timing 322 corresponding to the reproduction clock signal 311, and a detection signal sequence 325 representing user data and error correction information is output (step 804). The demodulator 126 demodulates the detection signal sequence 325 into a data bit sequence representing user data and outputs it to the error corrector 129. The error corrector 129 performs error correction, and 5
It is output to the file unit 131 as a 12-byte data string. This data string is transferred to the host computer by the I / F control unit 139.

In the optical disc apparatus of this embodiment, when erasing the data recorded on the optical disc medium 101, the user data area 220, the delay amount recording area 404,
Also, the optical head 10 is placed in the error correction information recording area 403.
Laser light is emitted from 4 to cause a phase change to erase the marks formed in these regions. Since this erasing operation is the same as that of an optical disk device provided with a known phase change type optical disk medium, detailed description thereof will be omitted.

As described above, in this embodiment, by recording the recording marks in the user data area 220 while shifting them, the recording marks are formed on the recording medium even when the same data as the previous data is recorded. Since different positions are provided, the crystallinity of the optical disk medium can be prevented from deteriorating. Therefore, in the optical disk device of this embodiment,
Even if the user data is recorded / reproduced / erased repeatedly a number of times, it is possible to suppress the deterioration of the reproduction sensitivity due to the deterioration of the crystallinity of the optical disk medium. As a result, it is possible to obtain a long life and high reliability of the optical disk device.

Further, in this embodiment, since the delay amount is recorded in the delay amount recording area, when the user data is reproduced,
By reproducing the data in the delay amount recording area, it is possible to detect how much the user data is delayed, and it is possible to generate a delayed clock signal used for discriminating the user data. Therefore, it is possible to reproduce the user data recorded with a delay using the delayed clock signal, so that the reproduction of the user data can be realized.

In the above embodiment, in order to determine the delay amount, one of the nine levels of delay amount is set by using the random number so that the recording mark is repeatedly recorded at the same location. I tried to avoid it. However,
In order to more surely avoid repetitive recording at the same location with the same delay amount, the delay amount recording data 1001 at the time of the previous recording recorded in the delay amount recording area 404 is reproduced before setting the delay amount. It is also possible to use a method of detecting the previous delay amount and setting a delay amount different from this delay amount. Instead of using a random number to determine the delay amount, an ordinal number may be generated by a counter and the delay amount may be determined based on this output.

Further, in the above embodiment, the variable delay unit 12 is used.
4 is arranged and the recording position of the user data is shifted in 9 steps every 5 ns. However, in order to reduce the cost of the optical disk device, it is possible to arrange a delay device that shifts the reference clock by 1/2. .

Further, in order to shift the recording position of the user data, in the above-mentioned embodiment, the margin portion of the servo mark area is used as the user data area. However, the frequency of the recording clock signal and the reproduction clock signal is increased to make it smaller. By forming the recording mark, it is possible to secure a margin for shifting the recording position of the user data without expanding the user data area.

Further, as a code for error correction, a code with higher efficiency is adopted, and the error correction information recording area is made smaller by reducing the redundancy, and instead the user data area is made larger, whereby the user data A margin for shifting the recording position may be secured.

In the above embodiment, the optical disk medium 101
Although the phase change type recording material is used as the above, by applying this embodiment also to the optical disc using the magneto-optical recording material, it is possible to attain a longer life and obtain high reliability.

Further, in the above-mentioned embodiment, in order to avoid recording the same data in the same location, the reference clock signal is shifted by a unit shorter than one cycle to shift the recording position of the user data. By rotating the code string of the recording data in one segment by, for example, a shift register without shifting the recording / reproducing clock with respect to the reference clock, even if the same data is recorded, the recording marks are recorded at the same position by overlapping. It is also possible to use a method of recording so as not to be recorded. Even in this case, since the same data is not recorded at the same location, the deterioration of the crystallinity of the optical disc medium due to the repeated rewriting is prevented, and the deterioration of the reproduction sensitivity can be suppressed.

Further, in this embodiment, the optical disk medium 10 is used.
1 is provided with a delay amount recording area 404, in which the delay amount 21
Although the delay amount recording data 1001 representing 7 is recorded, the present invention is not limited to this method, and in an optical disk device fixedly equipped with the optical disk medium 101, a RAM is provided in the controller 134.
It is also possible to arrange a storage unit such as, and store the data representing the delay amount 217 in this storage unit. However, the optical disk medium 10 of an unspecified number of users from the outside
In the case of an optical disk device in which 1 is set to be replaceable,
The configuration in which the delay amount of the optical disc medium 101 is recorded on the optical disc medium 101 itself as in the above embodiment is more convenient.

An example of the optical disk device in the case of rotating the recording data code sequence in one segment using the shift register will be briefly described with reference to FIG. Unlike the optical disk device of FIG. 1, the reference clock signal 123 is not delayed. A shift register 901 is arranged between the demodulator 126 and the error corrector 129, and a shift register 902 is arranged between the modulator 127 and the error corrector 129.
Are arranged. Further, the controller 134 is provided with a shift amount management unit 903 and a shift amount setting unit 904 that manage and set the shift amounts of the shift registers 901 and 902. The controller 134 manages the shift amount for rotating the recording data code string instead of the delay amount,
A recording mark whose recording position is shifted is formed in the delay amount recording area.

[0055]

As described above, according to the present invention, the mark position of the write data is shifted to suppress the deterioration of the information recording medium, and the timing of reproduction is controlled by the shift amount. It enables the reproduction of data from the marks recorded by shifting.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of an optical disc device according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing positions of recording marks recorded on an optical disc medium of the optical disc device of FIG. 1 and a delayed recording clock signal.

3 is an explanatory diagram showing the positions of recording marks recorded on the optical disc medium of the optical disc device of FIG. 1 and a delayed reproduction clock signal.

FIG. 4 shows an optical disc medium 1 of the optical disc device of FIG.
Explanatory drawing which shows the position of the delay amount recording area in a sector.

5 is an explanatory diagram showing recording marks of delay amount recording data recorded in a delay amount recording area of FIG. 4. FIG.

6 is an explanatory diagram showing a relationship between a delay set value, a delay amount, and delay amount recording data of the optical disc device of FIG.

FIG. 7 is an explanatory diagram showing an operation when recording is performed on an optical disc medium of the optical disc device of FIG. 1.

8 is an explanatory diagram showing an operation of the optical disc device of FIG. 1 when reproducing an optical disc medium.

FIG. 9 is a block diagram showing the configuration of an optical disc device according to another embodiment of the present invention.

[Explanation of symbols]

101 ... Optical disc medium, 102 ... Spindle motor,
103 ... Revolution control unit, 104 ... Optical head, 120 ... Preamplifier, 121 ... Clock pit detection unit, 122 ... P
LL, 123 ... Reference clock signal, 124 ... Variable delay device, 125 ... Discriminator, 126 ... Demodulator, 127 ... Modulator, 128 ... Laser driver, 129 ... Error corrector,
131 ... File management unit, 132 ... Delay amount demodulator, 13
3 ... Delay amount modulator, 134 ... Controller, 135 ... Random number generator, 136 ... Delay amount management unit, 137 ... Delay amount setting unit, 138 ... Mechanism system control unit, 211 ... Recording clock signal, 212 ... Recording code string, 213 ... recording track, 21
4 ... Clock pit, 216 ... Recording mark, 217 ... Recording delay amount, 220 ... User data area, 221 ... Servo mark area, 311 ... Reproduction clock signal, 317 ... Reproduction delay amount, 320 ... Reproduction waveform, 321 ... Discrimination level, 32
2 ... Discrimination timing, 325 ... Detection signal sequence, 401 ... Servo mark, 402 ... Track sector number, 403 ...
Error correction information recording area, 404 ... Delay amount recording area, 4
10 ... User data, 501 ... Delay amount recording mark, 90
1, 902 ... Shift register, 903 ... Shift amount management unit, 904 ... Shift amount setting unit, 1001 ... Delay amount recording data.

Claims (7)

[Claims] 1. An optical disk having an area in which a mark representing reference position data for forming a reference clock signal is formed in advance, an optical head for forming / detecting a mark representing data on the optical disk, Reference clock signal forming means for receiving a signal detected by the optical head, extracting a signal of a mark representing the reference position data from the signal, and forming a reference clock signal, and a signal representing the data to be recorded on the optical disk. Recording control means for delivering the data to the optical head in synchronization with the recording clock signal, reproduction control means for reproducing the data by synchronizing the signal reproduced by the optical head and the reproduction clock signal, and the phase of the reference clock signal By changing
A recording clock forming means for forming the recording clock signal, a means for storing the amount of phase change by the recording clock forming means, and a phase change amount recorded in the storage means for reading out only the phase change amount. An optical disk apparatus comprising: a reproduction clock forming unit that forms the reproduction clock signal by changing the phase of the reference clock signal. 2. The storage means according to claim 1, wherein the storage means is a part of the optical disc, and has means for recording a mark representing the delay amount in a predetermined delay amount storage area of the optical disc. Characteristic optical disk device. 3. The optical disk device according to claim 1, wherein the recording clock forming means changes the phase by delaying the reference clock signal. 4. The optical disk device according to claim 1, wherein the recording clock forming means determines a phase change amount of the reference clock signal by using a random number. 5. The recording clock forming means according to claim 1, wherein the recording clock forming means reads the phase change amount already stored in the storage means and determines a different amount from the phase change amount. Optical disk device. 6. A holding means for holding an optical disc, an optical head for forming / detecting a mark representing data on the optical disc, and a mark representing reference position data previously formed on the optical disc for the optical signal. Reference clock signal forming means for forming a reference clock signal from a signal detected by the head; recording control means for delivering a signal representing data to be recorded on the optical disk to the optical head in synchronization with the recording clock signal; Reproduction control means for reading data in synchronization with the signal reproduced by the head and the reproduction clock signal, and by changing the phase of the reference clock signal,
Recording clock forming means for forming the recording clock signal; means for recording the amount of phase change of the recording clock delay means on the optical disc; and reading the amount of phase change recorded on the optical disc,
An optical disk device comprising: a reproduction clock forming unit that forms the reproduction clock signal by delaying the reference clock signal by the amount of phase change. 7. An optical disc having a reference position data area in which a mark representing reference position data for forming a reference clock signal is formed in advance, and a recording area in which a mark representing data is formed. An optical disc having a region in which a mark indicating a distance from a mark representing data to a mark representing the data is formed.