JP2003030841A - Optical disk unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical disk unit capable of preventing the accumulation of the shifting of recording positions while securing continuity between previous recorded data and data to be newly recorded. SOLUTION: This optical disk unit is provided with a recording means for recording new data on an optical disk so as to be continuous to the recorded data of the optical disk, a detecting means for detecting the amount of deviation between the position of the recorded data and the original recording position of the data, and an adjusting means for adjusting the position for recording the new data so that the amount of deviation between a position for recording the tail end of the new data and an original position for recording the tail end of the data is smaller than the amount of deviation detected by the detecting means.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disc device for recording data on an optical disc.

[0002]

2. Description of the Related Art In recent years, various optical disk devices for recording and reproducing data using a light beam have been developed. In particular, CD-R / RW and DVD-R as recordable optical disks
AM, DVD-R / RW, etc. have been developed.

In the case of a DVD-R / RW, convex pits called land pre-pits are provided on the land tracks on the left and right of the groove track in order to specify the recording position. The land pre-pits are detected by binarizing a push-pull signal obtained when the groove track is irradiated with a light beam at a predetermined slice level.

Further, in order to obtain a recording clock signal which is synchronized with the linear velocity of the rotating optical disk, the track is provided with a swell in a predetermined cycle. This swell is called wobble. The wobbles are arranged so as to maintain a predetermined phase relationship with the land prepits. The wobble is detected by binarizing the push-pull signal at a predetermined slice level as in the land prepit. A recording clock signal corresponding to the unit time length of the recording mark can be obtained by detecting the frequency of the wobble and performing a predetermined multiplication on the frequency.

Recording on a DVD-R / RW is generally carried out in synchronization with a recording clock signal obtained from the wobble with reference to this land prepit signal. At that time, if there is previously recorded data, extremely high-precision recording position control is required to prevent discontinuities such as gaps and overwriting between the previously recorded data and newly recorded data. It

However, the track pitch of the DVD-R / RW is 0.74 μm, which is smaller than half of the track pitch of the CD-R / RW, which is a similarly recordable optical disk, of 1.6 μm. The influence of interference (crosstalk) from the track adjacent to the track radiating the light beam is more remarkable. Fluctuations in wobble amplitude and phase due to this crosstalk have a considerable effect as a jitter component on the recording clock obtained by multiplying the wobble frequency by a predetermined amount. Since the recording clock extracted from the wobble is mainly used for generating recording timing such as synchronization of recording data, there is a possibility that the recording position shift is caused by the jitter of the recording clock.

Further, the land pre-pit signal itself also has a re-jitter component due to interference with the already recorded recording mark, a power difference of the light beam during the recording mark formation during recording and in other states. .

Therefore, when the recording timing is determined and recorded based on the land prepit signal, discontinuity may occur between the previously recorded data and the newly recorded data. Such discontinuity affects bit synchronization processing and frame synchronization processing at the time of reproduction, and there has been a problem that a joint portion between previously recorded data and newly recorded data cannot be properly reproduced.

In order to solve such a problem, "Japanese Unexamined Patent Application Publication No.
000-187947 gazette "Optical disk recording apparatus", a method of reproducing a sync signal included in previously recorded data and adjusting the timing of data to be newly recorded based on the sync signal is devised. Has been done.

Further, due to the influence of the above-mentioned crosstalk and the state difference at the time of recording, the frequency and phase of the reproduced clock obtained from the previously recorded data and the reproduced clock obtained from the newly recorded data may be different. .

In such a case, there has been a problem that good reproduction cannot be performed until the frequency of the reproduction clock stabilizes at the joint between the previously recorded data and the newly recorded data.

In order to solve such a problem, "Japanese Unexamined Patent Application Publication No.
No. 000-298955, "Information recording apparatus and information recording method", the frequency or phase of the recording clock is synchronized with the frequency or phase of the reproduction clock obtained from the previously recorded data, and after the recording is started, A method has been devised in which the frequency or phase of the recording clock is restored to the original one with a predetermined time constant.

[0013]

However, the above-mentioned optical disk device has the following problems.

First, when the synchronization signal included in the previously recorded data is reproduced and the timing of the newly recorded data is adjusted based on the synchronization signal, the deviation of the previously recorded data also affects the newly recorded data. The gap remains.

Further, the frequency or phase of the recording clock is synchronized with the frequency or phase of the reproduction clock obtained from the previously recorded data, and after the start of recording, the frequency or phase of the recording clock is returned to the original one with a predetermined time constant. When returning, the frequency error of the recording clock that occurs in the transitional state where the frequency or phase of the recording clock changes after the recording starts, the timing error occurs at the recording position, and the deviation of the newly recorded data occurs. Will end up.

These recording position shifts are accumulated every time additional recording is performed, and may cause a large shift.

The present invention has been made in view of these problems, and in the case of newly adding data to previously recorded data, the continuity between the previously recorded data and the newly recorded data is ensured. At the same time, it is an object of the present invention to provide an optical disc device which prevents the accumulation of recording position deviations.

[0018]

The optical disk device of the present invention comprises a recording means for recording new data on the optical disk so as to be continuous with the data recorded on the optical disk, and a position where the data is recorded. The detection means for detecting the amount of deviation from the position where the data should be originally recorded, and the amount of deviation between the position where the end of the new data is recorded and the position where the end of the new data should be originally recorded are Adjustment means for adjusting the position at which the new data is recorded is provided so as to be smaller than the amount of deviation detected by the detection means, thereby achieving the above object.

The adjusting means sets the amount of deviation between the position at which the end of the new data is recorded and the position at which the end of the new data should be originally recorded to be substantially zero.
The position for recording the new data may be adjusted.

The recording means records the new data on the optical disk in synchronization with a recording clock, and the adjusting means controls the frequency of the recording clock to record the new data. May be adjusted.

The optical disk device further comprises a reference frequency detecting means for detecting a reference frequency of the recording clock, and the adjusting means controls the frequency of the recording clock so that the frequency of the recording clock approaches the reference frequency. You may.

Another optical disc apparatus of the present invention detects a predetermined prepit formed on the optical disc in advance, and outputs a prepit sync detection signal in response to the detection of the predetermined prepit. A circuit, a data sync detection circuit that detects a predetermined sync signal included in the data recorded on the optical disk, and outputs a data sync detection signal in response to the detection of the sync signal, and a recording clock And a recording circuit system for recording new data on the optical disk in synchronization with the recording clock based on the data sync detection signal. A time shift between the sync detection signal and the data sync detection signal is detected, and the detected time shift is detected. Controlling the frequency of the recording clock so positive that, thereby, the above-mentioned object can be achieved.

The recording clock generation circuit has a first timing signal generator for generating a first rectangular wave synchronized with the recording clock on the basis of the pre-pit sync detection signal and a reference for the data sync detection signal. And a second timing signal generator for generating a second rectangular wave synchronized with the recording clock, a phase of the first rectangular wave, and a second timing signal generator.
And a control circuit for controlling the frequency of the recording clock so that the difference between the phase of the rectangular wave and the phase of the rectangular wave approaches zero.

The first timing signal generator divides the recording clock to generate the first rectangular wave, and the second timing signal generator divides the recording clock. May generate the second rectangular wave.

The recording clock generation circuit sets a first timer preset to a first predetermined value in response to the pre-pit sync detection signal and a second predetermined value in response to the data sync detection signal. A preset second timer and a control circuit for controlling the frequency of the recording clock so that the difference between the value of the first timer and the value of the second timer approaches zero may be included. .

The first timer and the second timer may operate in synchronization with the recording clock.

Tracks having wobbles of a predetermined cycle are formed on the optical disc, and the optical disc device further includes a wobble detection circuit that detects the wobbles and outputs a wobble signal indicating the frequency of the wobbles. The recording clock generation circuit may control the frequency of the recording clock according to the wobble signal.

The recording clock generation circuit controls the frequency of the recording clock according to the wobble signal before starting the recording of the new data, and after starting the recording of the new data, The frequency of the recording clock may be controlled according to the wobble signal and the detected time difference.

The optical disk device further comprises a reproduction clock generation circuit for generating a reproduction clock from the data recorded on the optical disk, and the recording clock generation circuit is configured to perform the above-mentioned recording before the recording of the new data is started. The frequency of the recording clock is controlled according to the reproduction clock, and after the recording of the new data is started, the frequency of the recording clock is controlled according to the wobble signal and the detected temporal shift. May be.

[0030]

BEST MODE FOR CARRYING OUT THE INVENTION First, as an example of an optical disc to be recorded and reproduced by the optical disc apparatus of the present invention, a DV
D-R / RW (Digital Versatile)
Disk-Recordable / Re-Record
A description will be given of an optical disc that is compliant with the Able standard.

FIG. 10 shows the structure of an optical disc conforming to the DVD-R / RW standard.

This optical disk has recording grooves (groove tracks) formed on a spiral. When the groove track is irradiated with a light beam, the optical characteristics of the recording film on the groove track change. As a result, recording marks are formed on the groove tracks. In this way
Data is recorded on the groove track. An organic dye or a phase change material is used as the material of the recording film.

The data to be recorded includes one or more ECC (E
error correction code) block. The ECC block is the minimum unit of error correction.

The ECC block includes 16 sectors (sector 0 to sector 15). Each of the 16 sectors includes 26 frames (frame 0 to frame 25).

Each of the 26 frames includes a 2-byte sync signal (SY) and 1488T data (that is, a 32T sync code and a 1456T data code). The 32T sync code and the 1456T data code are obtained by subjecting 91-byte data to 8-16 modulation. Here, "1T" refers to the unit time length of the recording mark. "1T" is DV
At the standard speed of D-R / RW, 38.2 ns (1 / (2
6.16 MHz)).

The sync code is a code including "a recording mark having a length of 14T and a space having a length of 4T", or "a space having a length of 14T and 4T.
Is a code including a recording mark having a length of. Here, the space means an area sandwiched between the recording mark and the recording mark.

In the first frame (frame 0) of each sector, 4-byte address information called data ID and IED
(ID Error Detection code)
A 2-byte ID error detection code called "" is provided.

The groove track has a waviness of a predetermined cycle. The frequency of this wobble is
The standard speed of DVD-R / RW is about 140.6 KHz. Wobble frequency multiplied by 186 (140.6KH
z × 186 = 26.16 MHz), a clock signal having a unit time length of the recording mark can be obtained. That is, one wobble has a period of 186T, and one frame (1488T) has eight wobbles.

On the optical disk, pits called land pre-pits (LPP, Land Pre-Pit) are formed on the land track between the groove tracks as recording position reference and physical address information. Preformed in the process.

The land pre-pit has a convex shape when viewed from the surface irradiated with the light beam. The land prepit is associated with the groove track on the inner circumference side and is located at the apex of the wobble of the groove track on the inner circumference side.

Of the 26 frames included in one sector, the even-numbered frame is called an EVEN frame,
The odd-numbered frames are called ODD frames. In particular, the first frame (frame 0) of the sector is called an EVEN sync frame, and the second frame of the sector (frame 1) is called an ODD sync frame.

In principle, the LPP code obtained by the conversion shown in (Table 1) is arranged at the vertex position of the first 3 wobbles among the 8 wobbles of the EVEN frame. However, when the LPP code on the inner side and the LPP code on the outer side overlap with each other when viewed from the groove track, the LPP code on the outer side is exceptionally shifted and arranged in the ODD frame. This is to prevent adjacent LPP codes from interfering with each other (crosstalk).

By converting the 13 LPP codes included in one sector using the table of (Table 1), 1
It is possible to obtain 13-bit information (1-bit sync code and 12-bit LPP information) for each sector.

[0044]

[Table 1] FIG. 11 shows the structure of 13-bit information (sync code 1-bit and 12-bit LPP information). This information is
An ECC block (16 sectors) is a unit. The first 4 bits (bit1 to bit4) of the 12-bit LPP information are RA (Relative).
It is called “Address” and indicates the sector number in the ECC block. The remaining 8 bits (bit 5 to bit 12) of the 12-bit LPP information indicate two pairs of ECC block addresses (hereinafter referred to as pre-pit addresses) and error correction codes (parity) for each ECC block.

FIG. 12 is a diagram for explaining the timing of recording data on an optical disc conforming to the DVD-R / RW standard. In the DVD-R / RW standard, data is recorded in ECC block units. The data recording start position is a position shifted by 18 bytes backward from the boundary of the ECC block. The data recording end position is also a position shifted 18 bytes backward from the ECC block boundary. In this way, since the end of the previously recorded data is at a position shifted by 18 bytes from the boundary of the ECC block, recording of new data should be started at a position shifted by 18 bytes from the boundary of the ECC block. In this case, data discontinuity does not occur at the joint between the already recorded data and the newly recorded data.

1 included in the sync code of new data
The circumferential position on the groove track where the center of the 4T-long mark or space is recorded and the circumferential position of the land pre-pits arranged on the land track adjacent to the groove track are substantially the same. To do
New data is recorded on the groove track.

Recording new data by combining with already recorded data is called linking. In order to perform the linking so that the discontinuity of the data does not occur at the joint between the already recorded data and the newly recorded data, it is necessary to control the recording position with extremely high accuracy.

FIG. 13A is a diagram for explaining linking when the recording position of already recorded data is shifted to the front. In this case, a gap is created at the joint between the already recorded data and the newly recorded data.

FIG. 13B is a diagram for explaining linking when the recording position of already recorded data is displaced backward. In this case, overwriting of data will occur at the joint between the already recorded data and the newly recorded data.

(Embodiment 1) Hereinafter, with reference to the drawings, an optical disk device 100 according to Embodiment 1 of the present invention.
Will be explained. The same reference numerals indicate the same components.

FIG. 1 shows the configuration of an optical disk device 100 according to the first embodiment of the present invention.

The optical disk device 100 records information on the optical disk 1 or reproduces information recorded on the optical disk 1. The optical disk device 100 includes a spindle motor 2, a pickup 3, a motor driver 4, a power control circuit 5, a light beam drive circuit 6, a reproduction / amplification circuit 7, a pre-pit reproduction circuit 8, and a wobble reproduction circuit 9.
A data recovery circuit 10 and a recovered clock generation circuit 11
A pre-pit window protection circuit 12, a pre-pit sync detection circuit 13, a pre-pit demodulation circuit 14, a pre-pit address extraction circuit 15, a data sync detection circuit 16, a data sync window protection circuit 17,
-16 demodulation circuit 18, data ID extraction circuit 19, recording clock generation circuit 20, lock detection circuit 21, system controller 22, recording control circuit 23, error correction circuit 24, 8-16 modulation circuit 25 Including and

The motor driver 4 drives the spindle motor 2 so that the optical disk 1 rotates at a predetermined rotation frequency.

The pickup 3 irradiates the optical disc 1 with a light beam having a predetermined reproduction power. The light beam output from the pickup 3 is driven by the drive signal output from the light beam drive circuit 6. The light beam drive circuit 6 is controlled based on the reproduction power control signal output from the power control circuit 5.

The light beam applied to the optical disc 1 is reflected by the optical disc 1 and enters the pickup 3. The reflected light from the optical disk 1 has properties according to the optical characteristics and the physical characteristics of the recording film irradiated with the light beam.

The pickup 3 is provided with a plurality of light receiving circuits (not shown) and converts the amount of incident reflected light into an electric signal.

The reproduction / amplification circuit 7 fully adds the electric signals obtained by the conversion by the plurality of light receiving circuits, and further amplifies the fully added signal to thereby obtain an RF (Radi) signal.
oFrequency) signal is generated. Further, the reproduction amplifier circuit 7 obtains a difference signal indicating the difference between the electric signals converted by the light receiving circuits divided substantially in parallel to the track, and further amplifies the difference signal,
Generate a push-pull signal.

The pre-pit reproducing circuit 8 is provided with a comparator (not shown) for comparing the level of the push-pull signal with a predetermined slice level, and when the level of the push-pull signal is higher than the predetermined slice level, the pre-pit reproduction circuit 8 outputs the H level. A signal is output, and if the push-pull signal level is lower than a predetermined slice level, an L-level signal is output. In this way, the pulse-shaped pre-pit signal is output from the pre-pit reproduction circuit 8. Here, the predetermined slice level is set to be approximately an intermediate value between the maximum level of the land prepit portion of the push-pull signal and the maximum level of the fluctuation portion due to the wobble of the push-pull signal.

The wobble reproducing circuit 9 passes through a BPF (Band Pass Fi) through which a wobble frequency component (around 140.6 kHz at the standard speed of DVD-R / RW) passes.
lter) (not shown) and a comparator (not shown) for comparing the level of the signal after the noise component and the land prepit component are removed by the BPF with a predetermined slice level, and the level of the signal Is higher than a predetermined slice level, an H level signal is output, and when the level of the signal is lower than a predetermined slice level, an L level signal is output. In this way, the wobble reproduction circuit 9 outputs a rectangular wobble signal representing the frequency of the wobble. Here, the predetermined slice level is set to be approximately the intermediate value of the amplitude of the wobble signal.

The data reproducing circuit 10 is provided with a comparator (not shown) for comparing the level of the RF signal with a predetermined slice level, and when the level of the RF signal is higher than the predetermined slice level, it outputs an H level signal. Output, RF
When the signal level is lower than the predetermined slice level, the L level signal is output. In this way, a rectangular wave data reproduction signal is output from the data reproduction circuit 10. Here, the predetermined slice level is set so that, in a predetermined section, the H level integrated value of the binarized signal of the RF signal and the L level integrated value of the binarized signal of the RF signal are substantially equal. Is set.

The reproduction clock generation circuit 11 has a minimum length (3T) of H level or L level of the data reproduction signal.
The reproduction clock frequency is controlled so that 3 cycles of the reproduction clock enter and the maximum length of the H level or L level of the data reproduction signal (14T) includes the 14 cycles of the reproduction clock. Generate a recovered clock having a frequency corresponding to

The pre-pit window protection circuit 12 predicts the timing at which the next pre-pit signal is output from the pre-pit reproduction circuit 8 based on the timing of the pre-pit signal previously output from the pre-pit reproduction circuit 8, and the prediction is made. The pre-pit signal output from the pre-pit reproduction circuit 8 is excluded except at the timing. This allows
It becomes possible to reduce false detection of pre-pits.

The pre-pit sync detection circuit 13 is formed in advance from the pre-pit signal output from the pre-pit window protection circuit 12 in association with a predetermined pre-pit (for example, the head frame (frame 0) of a sector). The pre-pit sync detection signal corresponding to the land pre-pit) is extracted.

The pre-pit window protection circuit 12
May be omitted. Pre-pit window protection circuit 12
Pre-pit sync detection circuit 13 with or without
Means that a predetermined prepit formed in advance on the optical disc 1 (for example, a land prepit formed in advance in association with the first frame (frame 0) of a sector) is detected, and the predetermined prepit is detected. In response, it operates to output the pre-pit sync detection signal.

The pre-pit demodulation circuit 14 converts the pre-pit signal according to (Table 1) in synchronization with the pre-pit sync detection signal. As a result, 4-bit RA (Rel
LPP information including the active address) and 8-bit data is obtained.

The pre-pit address extraction circuit 15 is an LP
The data included in the LPP information is stored in the memory based on the RA included in the P information, a predetermined error correction is performed on the data stored in the memory, and the prepit address is extracted from the data stored in the memory. .

The data sync detection circuit 16 detects a predetermined synchronization signal contained in the data recorded on the optical disc 100 by synchronizing the data reproduction signal with the timing of the reproduction clock, and detects the predetermined synchronization signal. In response to this, the data sync detection signal is output. Here, the predetermined synchronization signal included in the data recorded on the optical disc 100 is, for example, a sync code including “a recording mark having a length of 14T and a space having a length of 4T” or a “14T Space with length and 4
A sync code including a recording mark having a length of T ”.

The data sync window protection circuit 17
The timing at which the next data sync detection signal is output from the data sync detection circuit 16 is predicted based on the timing of the data sync detection signal previously output from the data sync detection circuit 16, and the data sync is performed at a timing other than the predicted timing. The data sync detection signal output from the detection circuit 16 is eliminated. This makes it possible to reduce erroneous detection of a predetermined sync signal (for example, sync code) included in the data recorded on the optical disc 1.

The 8-16 demodulation circuit 18 performs 8-16 demodulation on the data reproduction signal in response to the data sync detection signal output from the data sync window protection circuit 17, and outputs demodulated data.

The data sync window protection circuit 1
7 may be omitted. In this case, the 8-16 demodulation circuit 18
Responds to the data sync detection signal output from the data sync detection circuit 16 with respect to the data reproduction signal.
16 demodulations may be performed and demodulated data may be output.

The data ID extraction circuit 19 extracts the data ID from the demodulated data.

The recording clock generation circuit 20 generates a recording clock, detects a time shift between the pre-pit sync detection signal and the data sync detection signal, and corrects the detected time shift. Controls the frequency of the recording clock. The configuration of the recording clock generation circuit 20 will be described later.

The lock detecting circuit 21 detects that the recording clock is within a predetermined frequency range and is stable, and outputs a lock signal.

The system controller 22 refers to the extracted pre-pit address or data ID to confirm that the pickup 3 has reached the position where the data should be recorded, and a lock signal indicating that the recording clock is stable. When it is detected, the recording control circuit 23 is instructed to record.

The recording control circuit 23 controls the recording operation based on the recording instruction from the system controller 22.
Specifically, the recording control circuit 23 determines whether or not the data is recorded immediately before the recording start point, and when the data is not recorded immediately before the recording start point, the recording is performed based on the pre-pit signal. The start point is determined, and when the data is recorded immediately before the recording start point, the recording start point is determined based on the data sync detection signal.

Whether or not data is recorded immediately before the recording start point is determined by referring to the TOC information recorded in the lead-in area, for example. Alternatively, it may be determined whether or not the data is recorded immediately before the recording start point, depending on whether or not the amplitude of the RF signal is equal to or greater than a certain value, or whether the synchronization signal is detected to be equal to or more than a certain value. Depending on whether or not the data is recorded immediately before the recording start point, it may be determined.

As described above, when the data is recorded immediately before the recording start point, the recording start point is determined based on the data sync detection signal so as to be continuous with the recorded data. It becomes possible to start recording new data. Therefore, the recording control circuit 23
Recording means for recording new data on the optical disc 100 so as to be continuous with the data recorded on the optical disc, together with the error correction circuit 14, the 8-16 modulation circuit 25, the power control circuit 5, the light beam drive circuit 6 and the pickup 3. Can function as.

The recording control circuit 23 outputs a recording gate signal. For example, when the recording gate signal is in the activated state (H level), the recording is permitted, and when the recording gate signal is in the inactivated state (L level), the recording is prohibited. In this case, the recording gate signal changes from the inactive state (L level) to the activated state (H level).
The point at which the transition to (i.e., the rising edge of the recording gate signal) corresponds to the recording start point.

When the recording gate signal is activated, the error correction circuit 24 adds an error correction code to the recorded data. The 8-16 modulation circuit 25 performs 8-16 modulation on the signal output from the error correction circuit 24, and outputs the resulting modulated signal in synchronization with the recording clock.

When the recording gate signal is activated,
The power control circuit 5 outputs a recording power control signal to the light beam drive circuit 6.

The light beam drive circuit 6 converts the binary modulation signal into a drive signal having a predetermined pulse pattern based on a predetermined write strategy, and outputs the drive signal.

The pickup 3 forms a recording mark by irradiating the optical disc 1 with a light beam corresponding to a drive signal and changing the optical characteristics of the recording film.

The configuration of the recording clock generation circuit 20 will be described in detail below.

As shown in FIG. 1, the recording clock generation circuit 20 includes a first timing signal generator 26 and a second timing signal generator 26.
Timing signal generator 27, phase difference detector 28,
The filter 29 and the PLL 30 are included.

The first timing signal generator 26 generates a first rectangular wave synchronized with the recording clock with the prepit sync detection signal as a reference. Such a first rectangular wave can be generated using, for example, a counter (first counter) that increments the count value by one in synchronization with the recording clock. The count value of the first counter is preset to a predetermined value (A) in response to the pre-pit sync detection signal regardless of the state (activated state or inactivated state) of the recording gate signal. In the first timing signal generator 26, the count value of the first counter is a predetermined value (B).
The level of the first rectangular wave from H level to L level
When the count value of the first counter reaches a predetermined value (C) after transition to the level, the level of the first rectangular wave is transitioned from the L level to the H level.

When the count value of the first counter reaches the predetermined value (D), the count value of the first counter is reset to "0". After that, the count value of the first counter is incremented again by 1 in synchronization with the recording clock. In this way, the first timing signal generator 26 outputs the first rectangular wave that alternately repeats the H level and the L level.

The second timing signal generator 27 generates a second rectangular wave synchronized with the recording clock with the data sync detection signal as a reference. Such a second rectangular wave can be generated using, for example, a counter (second counter) that increments the count value by one in synchronization with the recording clock. The count value of the second counter is preset to a predetermined value (E) in response to the data sync detection signal only when the recording gate signal is in the inactive state. When the count value of the second counter reaches the predetermined value (B), the second timing signal generator 26 changes the level of the second rectangular wave from the H level to the L level, and the second counter counts. When the value reaches the predetermined value (C), the level of the second rectangular wave is changed from the L level to the H level.

When the count value of the second counter reaches the predetermined value (D), the count value of the second counter is reset to "0". After that, the count value of the second counter is incremented again by 1 in synchronization with the recording clock. In this way, the second timing signal generator 27 outputs the second rectangular wave that alternately repeats the H level and the L level.

The predetermined value (A) and the predetermined value (E)
Indicates that the new data is at the ideal position on the groove track (that is, 1 when the sync code of the new data is included).
A position where the circumferential position on the groove track where the center of a mark or space having a length of 4T is recorded and the circumferential position of a land pre-pit arranged on a land track adjacent to the groove track coincide with each other. ), The difference between the phase of the first rectangular wave and the phase of the second rectangular wave is set to be substantially zero. Here, in this specification, “substantially 0” means to include a predetermined range including 0 which is allowable in the design of the optical disc device 100.

Further, the predetermined value (D) is preset so as to be equal to a multiple of the length of one wobble cycle.

As described above, the first timing signal generator 26 and the second timing signal generator 27 are recorded on the optical disc 1 when new data is added to the data recorded on the optical disc 1. It functions as a detecting means for detecting the amount of deviation between the position of the data being recorded and the position where the data should be originally recorded. The position of the data recorded on the optical disc 1 is obtained, for example, based on the data sync detection signal. The position where the data should be originally recorded is obtained based on the pre-pit sync detection signal, for example.

The phase difference detector 28 outputs a first phase difference signal indicating the difference between the phase of the first rectangular wave and the phase of the second rectangular wave. The phase difference detector 28 may operate only when the recording gate signal is in the activated state.

The filter 29 limits the time change amount of the first phase difference signal, and outputs the first phase difference signal having the limited time change amount to the PLL 30 as a correction amount signal. The reason why the time variation of the first phase difference signal is limited in this way is that the response speed is set so that the reproduction clock can be sufficiently tracked in the data reproduction PLL that reproduces the data recorded by the optical disc device 100. This is for adjustment. Therefore, the filter 29 can be omitted when such adjustment of the response speed is unnecessary. Filter 29
Can be realized by LPF, for example.

The PLL 30 sets the frequency of the recording clock so that the correction amount signal approaches a substantially zero level (that is, the difference between the phase of the first rectangular wave and the phase of the second rectangular wave is "0"). Control.

As described above, the phase difference detector 28, the filter 29, and the PLL 30 control the frequency of the recording clock so that the difference between the phase of the first rectangular wave and the phase of the second rectangular wave approaches zero. Function as a control circuit.

Further, the phase difference detector 28 and the filter 29
The PLL 30 and the PLL 30 are the case where the position of the data recorded on the optical disc 1 is deviated from the position where the data should originally be recorded, when new data is additionally written to the data recorded on the optical disc 1. However, the position where the new data end is recorded matches the position where the new data end should be originally recorded (that is,
As an adjusting means for adjusting the position at which new data is recorded, so that the deviation amount between the position at which the new data end is recorded and the position at which the new data end should be originally recorded is substantially zero) Function. The position at which new data is recorded can be adjusted, for example, by adjusting the frequency of the recording clock.

In the above-mentioned case, the adjusting means records in the optical disc 1 the amount of deviation between the position where the new data end is recorded and the position where the new data end should be originally recorded. The position at which new data is recorded may be adjusted so that it is smaller than the amount of deviation between the position of data and the position at which the data should originally be recorded.

Further, when the optical disc device 100 further comprises a reference frequency detecting means for detecting the reference frequency of the recording clock, the adjusting means is arranged so that the frequency of the recording clock approaches the reference frequency. The frequency of may be controlled. For example, the wobble reproducing circuit 9 (FIG. 1) can function as the reference frequency detecting means. This is because the frequency of the wobble signal output from the wobble reproducing circuit 9 can be used as the reference frequency of the recording clock.

FIG. 2 shows the configuration of the PLL 30.

The PLL 30 includes a noise filter 31, a phase comparator 32, a charge pump 33, and a first LPF.
34, VCO 35, frequency divider 36, and phase difference detector 3
7, an adder 38, a second LPF 39, and a phase shifter 40.

The noise filter 31 removes H pulses and L pulses contained in the wobble signal, which are equal to or less than a predetermined amount, as noise.

The phase comparator 32 compares the phase of the wobble signal from which noise has been removed with the phase of the phase-shift frequency-divided clock output from the phase shifter 40, and indicates the phase difference between these signals. Output the phase difference signal.

The charge pump 33 converts the second phase difference signal into a voltage level signal. The first LPF 34 removes high frequency components from the voltage level signal. The voltage level signal from which the high frequency components have been removed is input to the VCO 35.

The VCO 35 generates a recording clock by oscillating at a frequency corresponding to the voltage level signal.

The frequency divider 36 outputs a divided clock obtained by dividing the recording clock by 186.

The phase difference detector 37 detects the difference between the phase of the prepit signal and the phase of the wobble signal every time the prepit signal is input, and outputs the third phase difference signal indicating the detected phase difference. To do.

The second LPF 39 removes the high frequency component from the third phase difference signal, and outputs the limited amount of time change.

The adder 38 adds the output signal of the second LPF 39 and the correction amount signal to generate an addition correction amount signal.

The phase shifter 40 outputs the phase-shifted divided clock to the phase comparator 32 by shifting the phase of the divided clock according to the addition correction amount signal.

Next, referring to FIGS. 3 to 5, in the case where data is recorded at a position deviated from the position to be originally recorded, continuity with the recorded data is ensured. The operation of the optical disc apparatus 100 for recording new data on the optical disc 1 so as to prevent the accumulation of the deviation of the recording position will be described.

FIG. 3 shows an example of the waveforms of the pre-pit signal, the pre-pit sync detection signal and the data sync detection signal when the position of the data recorded on the optical disc 1 is shifted to the front from the position to be originally recorded. Indicates.

The pre-pit signal is supplied to the pre-pit reproduction circuit 8
(Fig. 1). The pre-pit sync detection signal is output from the pre-pit sync detection circuit 13 (FIG. 1). The data sync detection signal is output from the data sync detection circuit 16 (FIG. 1).

The first timing signal generator 26 outputs a first rectangular wave based on the prepit sync detection signal. The second timing signal generator 27 outputs a second rectangular wave based on the data sync detection signal.

FIG. 4 shows operations of the first timing signal generator 26 and the second timing signal generator 27 in the case shown in FIG.

The counter (first counter) incorporated in the first timing signal generator 26 increments the count value by one in synchronization with the recording clock. The count value of the first counter is preset to "24" in response to the pre-pit sync detection signal. In the first timing signal generator 26, the count value of the first counter is “46”.
The level of the first rectangular wave from H level to L level
Transition to the level and the count value of the first counter is "1.
When it reaches "39", the level of the first rectangular wave is changed from the L level to the H level.

The count value of the first counter is "1".
When it reaches "85", the count value of the first counter is reset to "0". After that, the count value of the first counter is incremented again by 1 in synchronization with the recording clock. In this way, the first timing signal generator 26 outputs the first rectangular wave that alternately repeats the H level and the L level. The period of the first rectangular wave is 186T. Therefore, the first rectangular wave can be generated by the first timing signal generator 26 by dividing the recording clock.

The counter (second counter) incorporated in the second timing signal generator 27 increments the count value by one in synchronization with the recording clock. The count value of the second counter is preset to "32" in response to the data sync detection signal. When the count value of the second counter reaches “46”, the second timing signal generator 27 changes the level of the second rectangular wave from the H level to the L level, and the count value of the second counter becomes "13
9 ", the level of the second rectangular wave is changed from the L level to the H level.

The count value of the second counter is "1".
When "85" is reached, the count value of the second counter is reset to "0". After that, the count value of the second counter is incremented again by 1 in synchronization with the recording clock. In this way, the second timing signal generator 27 outputs the second rectangular wave that alternately repeats the H level and the L level. The period of the second rectangular wave is 186T. Therefore, the second rectangular wave can be generated by the second timing signal generator 27 by dividing the recording clock.

When the position of the data recorded on the optical disc 1 matches the position to be originally recorded (that is, when the position of the data recorded on the optical disc 1 is not displaced), the first The square wave and the second square wave are
The phase difference between them is adjusted to be substantially “0”. Therefore, when the position of the data recorded on the optical disc 1 is shifted forward from the position to be originally recorded, as shown in FIG. 4, the phase is shifted before the first rectangular wave. Then, the second rectangular wave is output.

After that, when a predetermined condition is satisfied, the system controller 22 sends a recording instruction to the recording control circuit 2.
Output to 3.

The recording control circuit 23 activates the recording gate signal in accordance with the recording instruction and records new data on the optical disc 1 in synchronization with the recording clock based on the data sync detection signal. System (error correction circuit 24, 8-16 modulation circuit 25, power control circuit 5
And the light beam drive circuit 6).

Recording circuit system (error correction circuits 24, 8-16
The modulation circuit 25, the power control circuit 5, and the light beam drive circuit 6) record new data on the optical disc 1 in synchronization with the recording clock based on the data sync detection signal.

FIG. 5 shows the waveform of each signal and the operation of each circuit in the case shown in FIG.

When the recording gate signal is activated, each circuit of the recording circuit system starts the recording operation and prohibits the presetting of the second counter incorporated in the second timing signal generator 27. As a result, when the position of the data recorded on the optical disc 1 is shifted to the front of the position to be originally recorded, immediately after the start of recording, the phase is shifted before the first rectangular wave. The second rectangular wave is output. After the recording is started, the phase difference between the first rectangular wave and the second rectangular wave changes in accordance with the correction of the recording position shift.

The phase difference detector 28 includes a first rectangular wave and a second rectangular wave.
The phase difference with the rectangular wave of is detected, and the first phase difference signal is output. The filter 29 outputs a correction amount signal in which the time change amount is limited to the first phase difference signal.

Before the start of recording, the PLL 30 is in a state of controlling the frequency of the recording clock according to the prepit signal and the wobble signal. After the recording is started, the PLL 30 adds the correction amount signal to the loop of the PLL 30,
The frequency of the recording clock is controlled according to the correction amount signal in addition to the pre-pit signal and the wobble signal. Specifically, when the second rectangular wave is output with the phase shifted before the first rectangular wave, the frequency of the recording clock can be controlled so that the frequency of the recording clock becomes low. Good. On the contrary, when the second rectangular wave is output with the phase shifted after the first rectangular wave, the frequency of the recording clock may be controlled to increase the frequency of the recording clock.

The above-described control operation of the frequency of the recording clock is performed until the deviation of the recording position becomes "0" (that is, the first
Repeatedly (until the phase difference between the rectangular wave and the second rectangular wave disappears), the frequency of the recording clock is controlled based on the prepit signal and the wobble signal at the time when the recording position shift is eliminated.

The frequency of the recording clock may be controlled according to the wobble signal, instead of controlling the frequency of the recording clock according to the pre-pit signal and the wobble signal.

As described above, since the new data is recorded on the basis of the data sync detection signal at the combining portion of the previously recorded data and the newly recorded data, the previously recorded data is newly recorded. The continuity with the data can be secured. Even if the previously recorded data deviates from the original recording position, the amount of deviation is detected and the frequency of the recording clock is controlled according to the detected amount of deviation. There is nothing to do.

The example in which the PLL 30 controls the frequency of the recording clock using both the prepit signal and the wobble signal has been described, but the present invention is not limited to this.
The pre-pit signal and the wobble signal may not be input to the PLL 30. The PLL 30 adds at least the correction amount signal to the PLL loop of the recording clock generation,
It suffices if the frequency of the recording clock can be controlled.

For example, according to the correction amount signal, the phase comparator 3
Although the configuration in which the phase-shifted divided clock that is one of the two inputs is further shifted has been described as an example, the noise filter 3 that is the other input of the phase comparator 32 according to the correction amount signal.
The wobble signal output from 1 may be further shifted.

The same effect can be obtained by converting the correction amount signal into a voltage level signal and then adding it to the output of the charge pump 33 in an analog manner.

FIG. 6 shows another configuration of the PLL 30.

As shown in FIG. 6, PLL 30 includes a selector 601, a phase difference detector 602, a third LPF 603, and a phase shifter 604 in addition to the configuration shown in FIG. With this configuration, the frequency of the PLL can be controlled also by the second rectangular wave.

The selector 601 switches between the second rectangular wave phase-shifted by the phase shifter 604 and the wobble signal output from the noise filter 31 according to the switching signal.

The phase difference detector 602 is the phase shifter 60.
Second rectangular wave phase-shifted by 4 and noise filter 3
The phase difference from the wobble signal output from 1 is detected, and the fourth phase difference signal indicating the detected phase difference is output.

The third LPF 603 removes the high frequency component from the fourth phase difference signal, and outputs the fourth phase difference signal having a limited time change amount to the phase shifter 604 as the second correction amount signal. Output.

The phase shifter 604 shifts the phase of the second rectangular wave in accordance with the second correction amount signal so that the phase of the second rectangular wave matches the phase of the wobble signal.

FIG. 7 shows the waveform of each signal and the operation of each circuit in the case shown in FIG.

Before the start of recording, the second counter incorporated in the second timing signal generator 27 is operated in synchronization with the reproduction clock output from the reproduction clock generation circuit 11 (FIG. 1). The second timing signal generator 27 outputs a second rectangular wave synchronized with the reproduction clock.

Further, before the start of recording, the phase shifter 6
04 corrects the phase difference between the second rectangular wave and the wobble signal according to the second correction amount signal (for example, the phase of the second rectangular wave matches the phase of the wobble signal). )Operate. This operation corresponds to the operation in the period * 1 shown in FIG. When the correction of the phase difference between the second rectangular wave and the wobble signal is completed (for example, the phase of the second rectangular wave matches the phase of the wobble signal), the selector 60
1 is controlled so as to select the second rectangular wave instead of the wobble signal. As a result, the PLL 30 operates to generate the recording clock by multiplying the second rectangular wave obtained by dividing the reproduction clock. This operation corresponds to the operation in the period * 2 shown in FIG. By this operation, it is possible to obtain a recording clock having a frequency equal to the frequency of the reproduction clock.

The operation of the PLL 30 after the start of recording is similar to the operation of the PLL 30 described above with reference to FIG.

Thus, the frequency of the recording clock is controlled using the second rectangular wave generated based on the reproduction clock before the recording is started, and the deviation of the recording position is corrected after the recording is started. The frequency of the recording clock can be controlled according to the pre-pit signal and the wobble signal.
As a result, since the recording clock is obtained in synchronization with the frequency of the reproduction clock obtained from the data recorded on the optical disc 1, the difference between the frequencies of the recording clock of the data recorded on the optical disc 1 and the recording clock of the data to be newly recorded. Can be smaller. As a result, it is possible to ensure continuity even in the frequency of the reproduction clock of the data recorded on the optical disc 1 and the data to be newly recorded.

(Second Embodiment) Next, with reference to the drawings, an optical disk device 200 according to a second embodiment of the present invention.
Will be explained. The same reference numerals indicate the same components.

FIG. 8 shows the configuration of an optical disk device 200 according to the second embodiment of the present invention.

As shown in FIG. 8, the optical disk device 2
The configuration of 00 is the same as the configuration of the optical disc device 100 shown in FIG. 1 except the configuration of the recording clock generation circuit 20.

The recording clock generation circuit 20 includes a first timer 801, a second timer 802, and a subtractor 80.
3, a filter 29, and a PLL 30.

FIG. 9 shows a first timer 801 and a second timer 801.
The operation of the timer 802 is shown.

The first timer 801 has a first counter that increments the count value by one in synchronization with the recording clock. The count value of the first counter is preset to a predetermined value (F) in response to the pre-pit sync detection signal regardless of the state (activated state or inactivated state) of the recording gate signal. First timer 801
Displays the count value of the first counter in the first timer 80.
Output as a value of 1.

When the count value of the first counter reaches 1488, which corresponds to one frame, the first counter
The count value of the counter is reset to 0. After that, the count value of the first counter is incremented again by 1 in synchronization with the recording clock.

The second timer 802 has a second counter that increments the count value by one in synchronization with the recording clock. The count value of the second counter is preset to a predetermined value (G) in response to the data sync detection signal only when the recording gate signal is in the inactive state. The second timer 802 outputs the count value of the second counter as the value of the second timer 802.

When the count value of the second counter reaches 1488, which corresponds to one frame, the second counter
The count value of the counter is reset to 0. After that, the count value of the second counter is incremented again by 1 in synchronization with the recording clock.

The preset value (predetermined value (F)) of the first timer 801 and the preset value (predetermined value (G)) of the second timer 802 correspond to the ideal position () of new data on the groove track. That is, the positions of the marks or spaces having a length of 14T included in the sync code of the new data are circumferentially recorded on the groove track and the land prepits arranged on the land track adjacent to the groove track. Of the first timer 801.
Is set in advance so that the difference between the value of and the value of the second timer 802 is substantially zero.

The subtractor 803 has a first timer 801.
And a difference signal indicating the difference between the value of and the value of the second timer 802. Note that the subtractor 803 may operate only when the recording gate signal is in the activated state.

The filter 29 limits the time change amount of the difference signal output from the subtractor 803, and uses the difference signal having the limited time change amount as the correction amount signal.
Output to. The reason why the time change amount of the difference signal is limited in this way is to adjust the response speed so that the generation of the reproduction clock can be sufficiently tracked in the data reproduction PLL that reproduces the data recorded by the optical disc device 200. . Therefore, the filter 29 can be omitted when such adjustment of the response speed is unnecessary. Filter 29
Can be realized by LPF, for example.

The PLL 30 sets the frequency of the recording clock so that the correction amount signal approaches a substantially zero level (that is, the difference between the value of the first timer 801 and the value of the second timer 802 is “0”). Control.

In this way, the subtractor 803 and the filter 2
9 and the PLL 30, the value of the first timer 801 and the second
It functions as a control circuit for controlling the frequency of the recording clock so that the difference from the value of the timer 802 approaches 0.

The structure of PLL 30 is similar to that of the PLL described in the first embodiment.

As described above, since new data is recorded on the basis of the data sync detection signal at the joint between the previously recorded data and the newly recorded data, the previously recorded data and the newly recorded data are recorded. The continuity with the data can be secured. Even if the previously recorded data deviates from the original recording position, the amount of deviation is detected and the frequency of the recording clock is controlled according to the detected amount of deviation. There is nothing to do.

Since the correction amount can be derived by calculating the value of the first timer 801 and the value of the second timer 802, the recording clock generation circuit 20 can be constructed as a digital circuit. . In particular, the functions of the subtractor 803, the filter 29, etc. can be realized by software processing. This makes it possible to reduce the circuit scale and easily change the filter characteristics.

[0161]

According to the optical disk apparatus of the present invention, when new data is additionally recorded on the data recorded on the optical disk, new data is recorded on the optical disk so as to be continuous with the data recorded on the optical disk. To be done. This makes it possible to ensure continuity between the data recorded on the optical disc and new data. Even if the position of the data recorded on the optical disc is deviated from the position where the data should be originally recorded, the position where the new data end is recorded and the new data end is originally recorded. The position where new data is recorded is adjusted so that the amount of deviation from the proper position is smaller than the amount of deviation between the position of the data recorded on the optical disc and the position where the data should be originally recorded. This prevents the recording position deviation from being accumulated.

According to another optical disk device of the present invention, when new data is additionally recorded on the data recorded on the optical disk, the new data is recorded on the optical disk on the basis of the data sync detection signal. This makes it possible to ensure continuity between the data recorded on the optical disc and new data. Further, the time difference between the pre-pit sync detection signal and the data sync detection signal is detected, and the frequency of the recording clock is controlled so as to correct the time difference. This prevents the recording position deviation from being accumulated.

[Brief description of drawings]

FIG. 1 is an optical disk device 1 according to a first embodiment of the present invention.
Block diagram showing the configuration of 00

FIG. 2 is a block diagram showing the configuration of a PLL 30.

FIG. 3 is a diagram showing an example of waveforms of a prepit signal, a prepit sync detection signal, and a data sync detection signal.

FIG. 4 is a diagram showing operations of a first timing signal generator 26 and a second timing signal generator 27.

FIG. 5 is a diagram showing the waveform of each signal and the operation of each circuit.

FIG. 6 is a block diagram showing another configuration of the PLL 30.

FIG. 7 is a diagram showing the waveform of each signal and the operation of each circuit.

FIG. 8 is an optical disk device 2 according to a second embodiment of the present invention.
Block diagram showing the configuration of 00

FIG. 9 shows a first timer 801 and a second timer 8.
Diagram showing the operation of 02

FIG. 10 is a diagram showing a configuration of an optical disc conforming to the DVD-R / RW standard.

FIG. 11 is a diagram showing the configuration of 13-bit information (sync code 1-bit and 12-bit LPP information).

FIG. 12 is a diagram showing a timing of additional recording on a DVD-R.

FIG. 13A is a diagram for explaining linking when the recording position of previously recorded data is shifted to the front.

FIG. 13B is a diagram for explaining linking in the case where the recording position of previously recorded data is displaced backward.

[Explanation of symbols]

11 Regenerated clock generation circuit 13 Pre-pit sync detection circuit 16 Data sync detection circuit 20 Recording clock generation circuit 26 First Timing Signal Generator 27 Second Timing Signal Generator 28 Phase difference detector 29 filters 30 PLL 801 first timer 802 Second timer 803 subtractor

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Kohei Nakata             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. F-term (reference) 5D044 BC04 CC04 EF02 GK12 JJ01                 5D090 AA01 BB03 BB04 CC01 CC05                       CC14 CC16 EE01 FF07 GG26                       HH01 LL08

Claims (12)

[Claims] 1. A recording means for recording new data on the optical disk so as to be continuous with the data recorded on the optical disk, a position where the data is recorded and a position where the data should be originally recorded. A detection unit that detects a shift amount, and a shift amount between a position at which the end of the new data is recorded and a position at which the end of the new data should be originally recorded is smaller than the shift amount detected by the detection unit. As described above, the optical disc apparatus comprising: an adjusting unit that adjusts the position for recording the new data. 2. The adjusting means adjusts the new data end so that the amount of deviation between the position where the new data end is recorded and the position where the new data end should be originally recorded is substantially zero. The optical disk device according to claim 1, wherein a position for recording various data is adjusted. 3. The recording means records the new data on the optical disk in synchronization with a recording clock, and the adjusting means records the new data by controlling a frequency of the recording clock. The optical disk device according to claim 1, wherein a position to be adjusted is adjusted. 4. The optical disc apparatus further comprises a reference frequency detecting means for detecting a reference frequency of the recording clock, and the adjusting means controls the frequency of the recording clock so that the frequency of the recording clock approaches the reference frequency. The optical disc device according to claim 3, which controls the optical disc. 5. A prepit sync detection circuit for detecting a predetermined prepit formed in advance on an optical disc and outputting a prepit sync detection signal in response to the detection of the predetermined prepit, and recording on the optical disc. A predetermined sync signal included in the stored data, and a data sync detection circuit that outputs a data sync detection signal in response to the detection of the sync signal; a recording clock generation circuit that generates a recording clock; A recording circuit system for recording new data on the optical disk in synchronization with the recording clock based on the data sync detection signal, wherein the recording clock generation circuit includes the pre-pit sync detection signal and the data sync. The time difference from the detection signal is detected and the recording clock is adjusted so as to correct the detected time difference. Controlling the frequency of the click, the optical disk apparatus. 6. The recording clock generation circuit, a first timing signal generator for generating a first rectangular wave synchronized with the recording clock based on the pre-pit sync detection signal, and the data sync detection signal. And a second timing signal generator that generates a second rectangular wave synchronized with the recording clock, and a difference between the phase of the first rectangular wave and the phase of the second rectangular wave is zero. The optical disc apparatus according to claim 5, further comprising a control circuit that controls the frequency of the recording clock so that the frequency of the recording clock approaches. 7. The first timing signal generator generates the first rectangular wave by dividing the recording clock, and the second timing signal generator divides the recording clock. The optical disc device according to claim 6, wherein the second rectangular wave is generated by performing the above. 8. The recording clock generation circuit comprises: a first timer preset to a first predetermined value in response to the prepit sync detection signal; and a second predetermined timer in response to the data sync detection signal. A second timer preset to a value; and a control circuit for controlling the frequency of the recording clock so that the difference between the value of the first timer and the value of the second timer approaches zero. Item 5. The optical disk device according to item 5. 9. The optical disk device according to claim 8, wherein the first timer and the second timer operate in synchronization with the recording clock. 10. A track having a wobble of a predetermined cycle is formed on the optical disc, and the optical disc device includes a wobble detection circuit for detecting the wobble and outputting a wobble signal indicating a frequency of the wobble. The optical disk device according to claim 5, further comprising: the recording clock generation circuit that controls the frequency of the recording clock according to the wobble signal. 11. The recording clock generation circuit controls the frequency of the recording clock according to the wobble signal before starting the recording of the new data and after starting the recording of the new data. 11. The optical disk device according to claim 10, wherein the frequency of the recording clock is controlled according to the wobble signal and the detected temporal shift. 12. The optical disc apparatus further comprises a reproduction clock generation circuit for generating a reproduction clock from data recorded on the optical disc, wherein the recording clock generation circuit is provided before starting recording of the new data. , The frequency of the recording clock is controlled according to the reproduction clock, and after the recording of the new data is started, the frequency of the recording clock is changed according to the wobble signal and the detected temporal shift. The optical disk device according to claim 10, which is controlled.