JP2000076803A - Optical disk apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical disk apparatus capable of reducing time required for PLL pull-in of a reproduced signal and rapidly performing reproduction at the time of start-up of the apparatus or a seek operation. SOLUTION: Relative velocity coarse detection means 9 first adjusts a frequency of a reference clock so as to be in a predetermined proportion with a frequency of a wobbling signal. Then, relative velocity fine detection means 10 adjusts the reference clock so as to further coincide with a frequency of an RF signal. Thereafter, phase comparison means 6 performs phase detection so that PLL pull-in is performed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disk apparatus for reproducing or recording / reproducing a disk-shaped recording medium.

[0002]

2. Description of the Related Art In recent years, various digital data storage media have been put into practical use. For example, a read-only system using an optical disk such as a compact disk, and data can be recorded / reproduced using a magneto-optical disk as a recording medium. A mini disc (MD) system and the like are known.

In the mini-disc system, a wobbling groove 1a and a land portion 1b therebetween are formed on a disc 1 as shown in FIG. The wobbling groove 1a forms a recording track on which information is recorded, and expresses an absolute position address on the disk 1.

[0004] Such an optical disk as a recording medium,
When reproducing digital data recorded on a magneto-optical disk or the like, a reference clock signal is extracted from a reproduction signal detected from the disk, and the digital data is reproduced in synchronization with the reference clock signal. The reference clock signal is extracted by processing a reproduction signal detected from the disk by a phase locked loop (hereinafter, referred to as a PLL).

FIG. 10 is a block diagram showing an example of a configuration of a reproducing apparatus in a conventional optical disk apparatus, and shows a portion for extracting a reference clock from a reproduced signal detected from an optical disk.

The optical pickup 3 includes a spindle motor 2
The optical disk 1 is rotated by the laser beam, and the return light reflected by the optical disk 1 is received, and a detection signal corresponding to the received light amount is output to the RF amplifier 4 '. In the RF amplifier 4 ', the detection signal is amplified and binarized,
Let it be a reproduction signal S1. If the optical disc 1 is a disc having the aforementioned wobbling, the wobbling is also detected,
The amplified signal is used as a wobbling signal S2.

The reproduced signal binarized by the RF amplifier 4 'is output to a data reproducing system (not shown).
In addition, the PLL circuit 5 is also provided with this 2 to extract the reference clock.
The reproduced signal S1 is output as a value.

Meanwhile, the value of the reproduced signal S1 is inverted at intervals of an integral multiple of the predetermined bit interval T. When the rotation of the optical disc 1 is controlled and the reproduction signal S1 reaches the pull-in range (hereinafter referred to as a capture range) of the PLL circuit 5, the pull-in of the reproduction signal S1 into the PLL is started.
When the reproduction signal S1 is pulled in, the PLL circuit 5 extracts the preceding bit interval T and generates a reference clock S3 having a cycle corresponding to T.

The PLL circuit 5 includes a phase comparing means 6, a loop filter 7, and a variable frequency oscillating means 8.
The phase comparing means 6 detects a phase error between the reproduction signal 1 supplied from the RF amplifier 4 ′ and the reference clock signal 3 output from the frequency variable oscillating means 8, and outputs the phase error to the loop filter 7. . The loop filter 7 removes unnecessary frequency band components from the phase error and outputs the result to the frequency variable oscillating means 8. The variable frequency oscillating means 8
For example, an output frequency can be varied according to an input value, such as a voltage controlled oscillator (VCO) whose output frequency can be controlled according to an input voltage value. The variable frequency oscillating means 8 oscillates the reference clock signal 3 in accordance with the phase error supplied from the loop filter 7 while adjusting the oscillation frequency so that the phase error with respect to the reproduction signal 1 is eliminated. The reference clock signal 3 is fed back to the phase comparison means 6 to form a loop. Normally, the oscillation frequency when the input from the phase comparing means to the variable frequency oscillating means 8 is 0 is called a free-running frequency.

With the above configuration, the conventional optical disk device detects a signal from the optical disk 1 and extracts a reference clock.

[0011]

However, the conventional optical disk device has the following problems.

In the PLL circuit 5, the control band is usually designed to be narrow in order to minimize the phase shift between the reproduction signal and the reference clock due to the influence of noise or the like. But,
If the control band is narrow, the capture range becomes narrow, and the PLL cannot be pulled unless the frequency of the reproduced signal is close to the previous free-running frequency.

In the recording system based on the CLV (constant linear velocity) method used in compact disks and mini disks, the linear speed is kept constant by changing the rotation speed of the disk according to the radial position of the disk. . In such a disk, when the optical pickup 3 is sought to a place having a different radial position, it is necessary to control the rotation speed of the disk. However, it takes a very long time for the linear velocity at the reading position to reach a predetermined linear velocity due to the influence of inertia of the disk or the like.

[0014] In addition, regardless of the type of optical disk of a recording system such as CLV, even when the disk is stopped, such as when the apparatus is started, it takes a very long time to reach a predetermined rotation speed.

For this reason, even after the optical pickup 3 reaches a desired position on the optical disk 1, it takes a very long time until the rotation speed of the optical disk 1 reaches a predetermined rotation speed.
Since the reproduced signal cannot be drawn into the PLL, there is a problem that the data cannot be reproduced immediately.

The present invention has been made in view of the above problems, and has a simple configuration to extend the frequency range of the PLL pull-in and reduce the time required for the PLL pull-in. It is an object of the present invention to provide an optical disk device capable of performing reproduction.

[0017]

According to a first aspect of the present invention, an optical disk apparatus extracts a reference clock from a disk-shaped recording medium by a phase locked loop, and records the data on the disk-shaped recording medium by a reproducing unit in synchronization with the reference clock. In an optical disc apparatus for reproducing data, a relative speed coarse detection means for detecting a coarse relative speed error between the frequency of the recording data and the reference clock based on an analog reproduction signal from the reproduction means, ,
A relative speed fineness detecting means for detecting a fine relative speed error between the frequency of the recording data and the reference clock; a phase comparing means for detecting a phase error between the digital reproduction signal from the reproduction means and the reference clock; Switching means for selecting one of a coarse relative speed error from the relative speed coarse detection means, a fine relative speed error from the relative speed fineness detection means, and a phase error from the phase comparison means; and a signal selected by the switching means. And a reference clock generating means for generating the reference clock based on the reference clock.

According to a second aspect of the present invention, in the optical disk apparatus according to the first aspect, the relative speed coarse detecting means uses the wobbling signal recorded as absolute position information on a disk-shaped recording medium to record the relative position. And means for detecting a coarse relative speed error between data and said reference clock.

According to a third aspect of the present invention, in the optical disk device according to the first aspect, the relative speed coarse detection means determines a length of at least one type of recording data of the disk-shaped recording medium by the reference clock. It has coarse data length detecting means for detecting in units, and ratio error detecting means for detecting a deviation of a relative ratio between the detected data length and the cycle of the reference clock.

According to a fourth aspect of the present invention, there is provided the optical disk device according to any one of the first to third aspects, wherein the relative speed fineness detecting means includes a length of at least one type of recorded data of the disk-shaped recording medium. And a ratio error detecting unit for detecting a deviation of a relative ratio between the detected data length and the cycle of the reference clock. is there.

According to a fifth aspect of the present invention, in the optical disk device according to the fourth aspect, the data length fineness detecting means includes a quantizing means for quantizing the analog reproduction signal by the reference clock; Counting means for counting the clock count number of the reference clock from the amplitude center position of the analog reproduction signal to the next amplitude center position, based on a quantized value of the quantization means before and after the amplitude center position of the analog reproduction signal. Fraction counting means for calculating a time difference between a reference clock and the amplitude center position;
It has.

According to a sixth aspect of the present invention, in the optical disk device according to any one of the first to fifth aspects, the reference clock generating means includes an integrating means for integrating the selected signal; Frequency oscillating means for oscillating the reference clock having a frequency based on the output of the integrating means.

According to a seventh aspect of the present invention, in the optical disk device according to any one of the first to sixth aspects, when the phase-locked loop is pulled in, the switching means first switches from the relative speed coarse detection means to the phase locked loop. After the coarse relative speed error falls within a predetermined range, the coarse relative speed error from the relative speed fineness detection means is selected, and a certain time elapses after the selection of the fine relative speed error. After that, or after the fine relative velocity error falls within a predetermined range, the phase error from the phase comparing means is selected.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (Embodiment 1) Hereinafter, an embodiment of an optical disk apparatus according to the present invention will be described in detail with reference to the drawings.

FIG. 1 is a schematic block diagram illustrating the configuration of the optical disk device according to the present embodiment. In FIG. 1, the same elements as those in FIG. 10 are denoted by the same reference numerals, and detailed description will be omitted.

In FIG. 1, reference numeral 4 denotes an RF amplifier which outputs a wobbling signal S2 to a coarse relative speed detecting means 9 and a binarized reproduced signal S1 to a phase comparing means 6,
A signal obtained by amplifying the detection signal from the optical disc 1, that is, a signal that is not binarized (hereinafter, referred to as an RF signal S4) is output to the relative speed density detection unit 10.

Reference numeral 9 denotes a relative speed error (coarse relative speed error) between the data on the optical disc 1 and the output of the variable frequency oscillator 8.
Is a relative speed coarse detection means for detecting the data on the optical disk 1 by using a wobbling signal S2 which is absolute address information. Clock S3)
This is a relative speed fineness detecting means for detecting a relative speed error (fine relative speed error).

Reference numeral 13 denotes switching instruction means. The switching means 11 switches the signal input to the integrating means 12 to one of the coarse relative speed detecting means 9, the relative speed fine detecting means 10, and the phase comparing means 6. To instruct. Specifically, here, at the time of pulling in the PLL, first, the output of the relative speed coarse detection means 9 is selected, and when the output of the relative speed coarse detection means 9 falls within a predetermined range, the output to the integration means 12 is determined. The input is selected from the output of the relative speed density detection means 10. Subsequently, the output of the phase comparison means 6 is selected after a certain time or after the relative speed error detected by the relative speed density detection means 10 falls within a predetermined range.

As will be described later, the integrator 12 changes according to the relative speed error detected by the relative speed error coarse detector 9, the relative speed fineness detector 10, and the phase error detected by the phase comparator 6. The output signal is output to the variable frequency oscillation means 8.

The variable frequency oscillating means 8 outputs a reference clock S3 according to the input.

In the optical disk device of the present embodiment having the above-described configuration, when starting up the device or pulling in the PLL, such as during a seek in the CLV system, the output of the relative speed coarse detection means 9 is first determined. By generating the reference clock S3, the free-running frequency of the frequency variable means 8 is set to a frequency such that the wobbling signal S2 has a predetermined ratio. Is generated, the free-running frequency of the frequency variable means 8 is made equal to the frequency of the RF signal S4. Thereafter, a reference clock S3 is generated according to the output of the phase comparison means 6. This makes it possible to widen the frequency range of the pull-in of the PLL and shorten the time required for the pull-in.

The components (integrating means 12, relative speed coarse detecting means 9 and relative speed fineness detecting means 10) which are the characteristic parts of the optical disk apparatus of the present embodiment will be described below.

FIG. 2 is a diagram for explaining a specific operation of the integrating means 12. FIG. 2A shows an example of an input waveform input to the integrating means 12, and FIG. 2B shows an output of the integrating means 12 at that time.

First, when a 0-level signal is input to the integrator 12 and a positive pulse is input at time T0, the integrator 12 outputs a value obtained by integrating the input pulse. Then, the value is held until the next pulse is input. Subsequently, when a negative pulse is input at time T1, the pulse is integrated,
The value is held until the next pulse, and the frequency
Output to

For this reason, the integrating means 12 integrates the pulse corresponding to the relative speed error detected by the relative speed coarse detecting means 9 and the relative speed fine detecting means 10 described later, and holds the value. The free-running frequency of the frequency variable oscillating means 8 is adjusted to substantially match the frequency of the RF signal.

Thereafter, the input to the integrating means 12 is switched to the input to the phase comparing means 6. At this point, the free-running frequency of the frequency variable oscillating means 8 is made substantially equal to the frequency of the RF signal as described above. , Can be within the capture range, so that the PLL can be pulled in.

As described above, the integrating means 12 can change the free-running frequency of the frequency variable oscillating means 8 in accordance with the input relative error, thereby expanding the apparent capture range. Further, the integrating means 12 has a function of integrating the input signal as described above and also a function of a loop filter for cutting off a high-frequency signal.

Relative velocity coarse detection means 9 In a disk in which absolute position information on the disk is recorded using wobbling, the carrier frequency of the wobbling and the frequency of the data of the RF signal have a fixed ratio. It is decided. Relative speed coarse detection means 9
Is calculated by comparing the number of reproduction wobbling during a certain period (for example, from the rising of the reproduction wobbling signal S2 to the rising after a predetermined number of times) with the number of reference clocks S3 output from the frequency variable oscillating means 8. The relative speed between the two is detected. Then, the relative speed detects an amount of deviation from the determined ratio, and outputs a value corresponding to the amount of deviation to the switching means 11 in the subsequent stage.

FIG. 3 is a diagram showing an example of the configuration of the relative speed coarse detection means 9. 3, the wobbling signal is sampled by the AD converter 91 for each reference clock S3 output from the variable frequency oscillation means 8.

This sample data is input to a two-stage shift register composed of a register 92 and a register 93, and the input is held for each reference clock S3. The zero-cross detector 94 outputs a zero-cross detection signal when the values of the registers 92 and 93 exceed the value of the center of the amplitude of the wobbling signal S2. The zero cross signal is frequency-divided by frequency dividing means 95 and output to counter 96. The counter 96 is reset by the divided zero-cross detection signal, and otherwise counts the reference clock S3. The output of the counter 96 is held in the register 97 by the divided zero-cross detection signal. Accordingly, the register 97 indicates how many times the reference clock has occurred from the zero-cross signal to the zero-cross signal after a predetermined number of times.
That is, the cycle of the wobbling signal S2 and the reference clock S
3 represents the relative ratio of the three periods. Then, the output of the register 97 is input to the error calculating means 98, where the deviation from a predetermined ratio is calculated, and the relative speed error is output.

The output of the relative speed error coarse detection means 9 operating as described above is input to the integration means 12 by the selection of the switching means 11, and the frequency of the reference clock S3 and the frequency of the reproduction wobbling signal S2 are determined. Adjust so that the ratio is as follows.

As described above, the frequency of the reproduction wobbling signal S2 and the frequency of the RF reproduction signal S1 are determined so as to have a fixed ratio. It recognized. Therefore, even if the relative speed coarse detection means 9 adjusts the frequency of the reproduced wobbling signal and the output frequency of the frequency variable oscillation means 8 to completely match the predetermined ratio, it is actually recorded on the optical disc 1. Frequency of the existing RF signal. If the shift amount is larger than the capture range of the PLL, the PLL cannot be pulled in. For this reason, it is necessary to detect the frequency of the data on the optical disc more precisely than the relative speed error detected by the wobbling signal.

In the relative velocity density detection means 10, the actual RF
The relative speed error between the output of the variable frequency oscillating means 8 and the RF signal is detected from the signal S4, and the free-running frequency of the variable frequency oscillating means 8 is adjusted to be substantially equal to the frequency of the actual RF signal.

FIG. 4 is a diagram for explaining a specific operation of the relative speed fineness detecting means 10. In FIG. 4, the data length discriminating means 110 and the error calculating means (data length error detecting means) 111 are omitted to form the data length dense detecting means.

In FIG. 4, an RF signal S4 is sampled by an AD converter (quantizing means) 101 for each reference clock S3 output from the variable frequency oscillation means 8.

This sample data is input to a two-stage shift register composed of a register 102 and a register 103, and the input is held for each reference clock S3. The zero-cross detector 104 includes the register 102, the register 10
When the value of “3” exceeds the value of the amplitude center of the RF signal, a zero-cross detection signal is output, and a counter (counting means) 105
Is reset by the zero cross detection signal, and otherwise counts the reference clock S3. Counter 10
5 is output to the register 106 by the zero-cross detection signal.
Is held. Accordingly, the register 106 indicates how many times the reference clock S3 has occurred from the zero cross signal to the zero cross signal. That is, it indicates the relative ratio of the cycle of the RF signal S4 to the cycle of the reference clock S3.

However, the ratio here is in units of the reference clock, and the accuracy is low. Therefore, there is a zero-cross position calculator (fraction counting means) 107 for calculating an accurate zero-cross position from amplitude data before and after the zero-cross signal. As shown in FIG. 5, the zero-cross position calculator 107 calculates t0 by assuming that the ratio a0: a1 of the amplitude before and after the zero-cross position is approximately equal to the ratio t0: t1 of the temporal distance from the zero-cross position. . That is, t0
Is calculated as t0 = T · a0 / (a0 + a1), where T is the cycle of the reference clock S3.

The output of the zero-cross detector 104 is input to a shift register composed of a register 108 and a register 109. Since the registers 108 and 109 hold the input for each zero cross signal, the register 108 holds t0α in FIG. 5 and the register 109 holds t0β.

Now, tm shown in FIG. 5 is tm = (value held in register 106 + 1) × T, and tw = tm + t0β−t0α, so tw = (value of register 106 + 1) × T + ( Register 1
09 value) − (value of register 108).

The detected tw is used as the signal length determining means 110
Is input to The signal length determining means 110 detects the mark length of the signal from the value of tw. This is because the signal recorded on the optical disc 1 is not a signal of a single length, but signals of several lengths are recorded randomly under a certain rule, and a relative speed error is detected. This is because it is necessary to determine what length the signal is.

In the detection of the signal length, since the error between the frequency of the reference clock and the frequency of the reproduced signal has already been reduced to some extent (to the error permitted by the disk) by the relative speed coarse detection means 9, It can be easily determined.

For example, suppose that the error allowed by the disk is equivalent to N as the value of tw, and if there is no relative speed error, if the value of tw of the signal of the minimum length is M, The possible tw for a signal of length is: M−N ≦ tw ≦ M + N.

When tw in such a range is input to the signal length determining means, the error calculating means (data length error detecting means) 111 calculates the relative speed error VErr as VErr = tw-M.

The same determination is made for signals of other lengths, and a relative speed error can be obtained by subtracting a predetermined value from tw in the error calculating means 111.

As a result, since the speed can be detected with an accuracy higher than the sampling clock (reference clock), an accurate speed error can be detected at a low sampling frequency.

The output of the relative speed error density detection means 10 operating as described above is changed by the selection of the switching means 11.
The frequency of the reference clock S3, which is input to the integration means 12, is adjusted to match the frequency of the reproduction wobbling signal S2.

Next, the operation of the optical disk device of the present invention will be described with reference to the flowchart of FIG.

(Step 1) When the extraction of the reference clock S3 is started, the switching instructing means 13 switches to the switching means 1
1 is controlled, and the output of the coarse relative speed detecting means 9 is input to the integrating means 12.

(Step 2) Until the output (relative speed error) of the relative speed coarse detecting means 9 falls within a predetermined range, the reference clock S3 output from the frequency variable oscillating means 8 matches the speed of the reproduction wobbling signal S2. Will be adjusted to When the relative speed error falls within a predetermined range, the switching instructing unit 13 controls the switching unit 11 to output the output of the relative speed fineness detecting unit 10 (the relative speed error between the RF signal S4 and the reference clock S3) to the integrating unit 12. To enter.

(Step 3) Relative speed error density detecting means 1
By inputting the output of 0 to the integrating means 12 and controlling the variable frequency oscillating means 8, the speed of the reference clock S3 is precisely adjusted to match the speed of the reproduced RF signal S4.

(Step 4) In the generation of the reference clock S3 based on the output of the relative speed density detection means 10, a certain time (wait time) elapses after the switching means 11 selects the relative speed density detection means 10. Do until. In this waiting time, the relative speed error is reduced from the speed error between the reproduction signal and the reference clock S3 (corresponding to the maximum speed error at the time of step 3) due to the tolerance of the disk to the capture range of the PLL. A predetermined amount of time.

(Step 5) After the elapse of the waiting time, the switching instruction means 13 controls the switching means 11 and inputs the output of the phase comparing means 6 to the integrating means 12. That is, the phase is detected.

(Step 6) At the time of step 5, RF
Since the signal S4 and the free-running frequency of the frequency variable oscillating means 8 are substantially equal, the PLL can be pulled in. That is, the reference clock S3 and the RF signal S4 can be synchronized.

In step 5, the integrating means 12
The input is switched after a certain period of time, but it is needless to say that the input may be switched when the output of the relative speed error density detection means 10 becomes lower than a predetermined level.

In this embodiment, the reference clock S3 is extracted by the above configuration and procedure. That is, first, the relative speed coarse detection means 9 capable of high-speed processing adjusts the frequency of the reference clock S3 and the frequency of the wobbling signal S2 so as to have a predetermined ratio. Using the detection means 10, the actual RF signal S4
The reference clock S3 is adjusted so as to match the frequency. After that, the phase is detected and the PLL is pulled in. Therefore, by changing the free-running frequency of the frequency variable oscillating means 8, the apparent capture range can be expanded. Further, the time required for pulling in the PLL can be shortened, and the reproduction can be quickly performed at the time of starting the apparatus or at the time of seeking.

(Embodiment 2) Next, an optical disk device according to Embodiment 2 of the present invention will be described. FIG. 7 is a schematic block diagram illustrating the configuration of the optical disk device according to the present embodiment. In FIG. 7, components having the same functions as those shown in FIG. 1 are denoted by the same reference numerals, and detailed description thereof will be omitted.

In FIG. 7, reference numeral 14 denotes a coarse relative speed detection means for receiving the RF signal S4 and the reference clock S3 and detecting a relative speed error between the RF signal S4 and the reference clock S3.

FIG. 8 shows an example of the configuration of the relative speed coarse detection means 14. In the configuration shown in FIG.
The relative speed is detected by detecting the shortest signal of the signal S4 and detecting the ratio of the cycle of the signal to the cycle of the reference clock S3.

In FIG. 8, the RF signal S 4 is sampled by the AD converter 141 for each reference clock output from the variable frequency oscillator 8.

This sample data is input to a two-stage shift register including a register 142 and a register 143, and the input is held for each reference clock S3. The zero-cross detector 144 includes the register 142, the register 14
When the value of 3 crosses the value of the amplitude center of the RF signal S4, a zero-cross detection signal is output. The counter (coarse data length detecting means) 146 is reset by the zero cross detection signal, and otherwise counts the reference clock S3. The output of the counter 146 is held in the register 147 by a zero-cross detection signal. Therefore, the register 147 indicates how many times the reference clock S3 has occurred from the zero cross signal to the zero cross signal. That is, it indicates the relative ratio of the cycle of the RF signal S4 to the cycle of the reference clock S3.

The comparing means 148 compares the value of the register 147 with the value of the register 149, and
Only when the value of 47 is smaller, the value of the register 149 is updated to the value of the register 147. That is, register 1
49, the shortest signal length is maintained.
The value held in the register 149 is reset for each signal obtained by dividing the zero-cross signal, and the register 149 is loaded with the maximum value. Therefore, in the comparison with the first zero-cross signal after the value is reset, the value of the register 147 always becomes smaller,
The value of 49 is updated.

The value of the register 149 is output to the error calculating means (data length error detecting means) 150 for each signal obtained by dividing the zero cross signal. That is, the shortest signal length in a certain period is output.

Since the relative ratio between the shortest signal length and the reference clock S3 is determined, the error calculation means 150
Then, a deviation from the ratio is calculated and output as a relative speed error.

With the above configuration, the relative speed coarse detection means 1
4 detects a relative speed error between the reference clock and the RF signal from the RF signal. In the above configuration, the relative speed error is detected based on the length of the shortest signal of the RF signal. However, the relative speed error may be detected by detecting the length of the longest signal. Further, in the above configuration, the relative speed error is detected for each signal obtained by dividing the zero cross, but it is needless to say that the relative speed error may be detected for a predetermined time or for a predetermined number of reference clocks.

The switching instructing means 13 controls the switching means 11 in the same procedure as that of FIG. 6 described in the first embodiment, and switches the input of the integrating means 12.

In this embodiment, the reference clock S3 is extracted by the above configuration and procedure. In other words, the relative speed coarse detection means 14 adjusts the frequency of the reference clock S3 to substantially match the frequency of the RF signal S4, and then further uses the relative speed fineness detection means 10 to further increase the frequency of the RF signal S4. The reference clock 3 is adjusted to exactly match. After that, the phase is detected and the PLL is pulled in. Therefore, by changing the free-running frequency of the frequency variable oscillating means 8, the apparent capture range can be expanded.

As described above, in the optical disk device of the present invention, since the PLL is pulled in using only the RF signal S4, even if the optical disk has no wobbling, the PLL can be used.
The time required for L pull-in can be shortened, and, consequently, the reproduction can be quickly performed at the time of starting the apparatus or at the time of seeking.

The present invention is not limited to the above embodiment. For example, as the relative speed fineness detecting means, means for detecting a wobbling signal in units of a reference clock cycle or less (however, in this case, the wobbling signal and the reproduction (An error with the signal is a problem). Further, the timing of the switching by the switching means is not limited to the above, and for example, the switching timing may be variable.

[0079]

According to the present invention, when generating a reference clock synchronized with a reproduction signal, first, the frequency of the reference clock is roughly adjusted to the frequency of the RF signal by high-speed processing, and then the frequency of the reference clock is adjusted to the RF signal. Fine-tune to the frequency of
Thereafter, the phase of the reference clock and the phase of the reproduced signal are adjusted.

As a result, the apparent capture range of the PLL can be widened, the time required for pulling in the PLL can be shortened, and the reproduction can be quickly performed at the time of starting the apparatus or at the time of seeking.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram illustrating an example of an optical disk device according to a first embodiment.

FIG. 2 is a waveform diagram showing input / output waveforms of an integrating means 12;

FIG. 3 is a schematic configuration diagram illustrating an example of a relative speed coarse detection unit 9 according to the first embodiment.

FIG. 4 is a schematic configuration diagram illustrating an example of a relative speed density detection unit 10;

FIG. 5 is a waveform chart showing a principle of detecting a relative speed error of the relative speed fineness detecting means 10.

FIG. 6 is a flowchart illustrating the operation of the optical disc device according to the first embodiment.

FIG. 7 is a schematic configuration diagram illustrating an example of an optical disk device according to a second embodiment;

FIG. 8 is a schematic configuration diagram illustrating an example of a relative speed coarse detection unit 9 according to the second embodiment.

FIG. 9 is a view for explaining a wobbled guide groove.

FIG. 10 is a schematic configuration diagram showing an example of a conventional optical disk device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Optical disk 2 Spindle motor 3 Optical pick-up 4 RF amplifier 6 Phase comparison means 7 Loop filter 8 Frequency variable oscillation means 9 Relative speed coarse detection means 10 Relative speed fine detection means 11 Switching means 12 Integration means 13 Switching instruction means 14 Relative rough speed detection means

Claims (7)

[Claims] 1. An optical disk device for extracting a reference clock from a disk-shaped recording medium by phase-locked loop and reproducing data recorded on the disk-shaped recording medium by a reproducing unit in synchronization with the reference clock, wherein: A relative speed coarse detection means for detecting a coarse relative speed error between the frequency of the recording data and the reference clock based on the reproduction signal; and a close relative relative frequency of the recording data and the reference clock based on the analog reproduction signal. A relative speed fineness detecting means for detecting a speed error; a phase comparing means for detecting a phase error between the digital reproduction signal from the reproduction means and the reference clock; a coarse relative speed error from the relative speed coarse detection means; Select either the fine relative speed error from the fine speed detection means or the phase error from the phase comparison means And Toggles means, on the basis of the selected signal by the switching means, the optical disk apparatus characterized by having a reference clock generating means for generating the reference clock. 2. The optical disk device according to claim 1, wherein the relative speed coarse detection means calculates a coarse difference between the recording data and the reference clock from a wobbling signal recorded as absolute position information on a disk-shaped recording medium. An optical disc device for detecting a relative speed error. 3. The optical disk device according to claim 1, wherein said relative speed coarse detection means detects a length of at least one type of recording data of a disk-shaped recording medium in units of said reference clock. An optical disc device comprising: a detection unit; and a data length error detection unit that detects a deviation of a relative ratio between a detected data length and a cycle of the reference clock. 4. The optical disc device according to claim 1, wherein the relative speed fineness detecting means sets a length of at least one type of recording data of the disc-shaped recording medium in a unit of a reference clock or less. An optical disc device comprising: a data length fineness detecting means for detecting; and a data length error detecting means for detecting a deviation of a relative ratio between the detected data length and the cycle of the reference clock. 5. The optical disc device according to claim 4, wherein the dense data length detecting means includes: a quantizing means for quantizing the analog reproduced signal by the reference clock; and an amplitude center position of the analog reproduced signal. Counting means for counting the number of clock counts of the reference clock up to the next amplitude center position; and the reference clock and the amplitude center position based on quantization values of the quantization means before and after the amplitude center position of the analog reproduced signal. An optical disc device comprising: a fraction counting means for calculating a time difference. 6. The optical disk device according to claim 1, wherein the reference clock generating unit integrates the selected signal, and a frequency based on an output of the integrating unit. An optical disc device comprising: a variable frequency oscillating means for oscillating the reference clock. 7. The optical disk device according to claim 1, wherein the switching unit first selects a coarse relative speed error from the relative speed coarse detection unit when pulling in the phase locked loop. After the coarse relative speed error falls within a predetermined range, the fine relative speed error is selected from the relative speed fineness detection means, and after a certain time has elapsed after the selection of the fine relative speed error,
Alternatively, the phase error from the phase comparing means is selected after the fine relative velocity error falls within a predetermined range.