JP2003263747A - Optical disk recording/reproducing device and address detecting method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical disk recording/reproducing device and an address detecting method thereof demonstrating satisfactory address detecting accuracy even for the optical disk of phase modulation address system. <P>SOLUTION: The optical disk recording/reproducing device for recording/ reproducing the information by irradiating the optical disk with a light spot, whereon a groove with the phase modulated address is provided, is furnished with a phase detecting circuit 44 for producing the address by detecting a wobble signal and a delay circuit 40 for producing a timing signal delayed from the wobble signal, and further, the delayed amount by the delay circuit 40 is controlled by a controller 64 for satisfactorily (at the maximum) controlling the address detecting accuracy. To put it concretely, an amplitude measuring circuit 60 is prepared for detecting the amplitude of phase detection so that the amplitude of the detected phase detecting signal becomes maximum. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disk recording / reproducing apparatus for recording and / or reproducing information by positioning a light spot on an optical disk, and in particular, uses a groove whose phase is modulated as an address system. The present invention also relates to an optical disk recording / reproducing apparatus capable of exhibiting sufficient address detection accuracy even in an optical disk, and further to an address detecting method therefor.

[0002]

2. Description of the Related Art Conventionally, in order to position an optical spot from an optical head (pickup) on a target track on an optical disc which is a recording medium, an optical disc apparatus has been used.
It is widely practiced to use the address provided on the optical disc. A plurality of methods have been put into practical use for this address, and they are roughly classified into those recorded in pits and those in which grooves are FM-modulated.

If the address is recorded in pits,
The amplitude of the reproduction signal is binarized, the PLL is synchronized with it, and the synchronization signal is used for discrimination, whereby the address is identified. On the other hand, in the method of FM modulating the groove,
The address is identified by binarizing the cycle of the wobble signal recorded on the optical disk, synchronizing it with the PLL, and discriminating with this synchronizing signal. in this way,
In both of the above methods, the discrimination is performed by the synchronization signal, and according to these methods, the address detection accuracy does not deteriorate depending on the rotation speed of the optical disk.

On the other hand, so-called phase modulation is known as a technology in the field of communication engineering. A phase detection circuit is generally used for this demodulation. The phase detection circuit is a circuit that multiplies a modulation signal by a reference signal that is a sine wave having the same frequency and generates an average value thereof. In general, the modulation frequency has a fixed value. Therefore, the phases of the modulation signal and the reference signal do not deviate except for the fluctuation factors of the designed circuit.

[0005]

However, when the above-mentioned phase modulation is applied to the address system of the optical disk, that is, when the groove is phase-modulated, this phase detection circuit is provided with the above communication. There are problems that did not occur in engineering.

This is because, when the phase modulation is applied to the address system of the optical disk, the modulation frequency depends on the rotation speed of the optical disk. In particular, CAV (Constant Ang
In the regular velocity method, the modulation frequency changes in the range of 1 to 2.4 times depending on the position of the light spot.

In general, the phase detection circuit does not directly use the modulation signal but uses a signal whose band is limited by a filter or the like. The reference signal is also created from this modulated signal, and in that case also a filter is used. The characteristics of these two filters are completely different.
That is, the former has a relatively wide band because it needs to pass a signal band, and the latter has a relatively narrow band because it needs to reduce noise. Therefore, the phase of the signal that has passed through the filter is shifted according to the modulation frequency.
Then, if the phase between the modulated signal and the reference signal is shifted, the amplitude of the phase-detected signal becomes small,
That is, the accuracy of address detection is reduced. Further, variations in the delay amount in each circuit, further variations in the characteristics of the filter circuit, and the like cause the phases of the modulation signal and the reference signal to shift, which again reduces the address detection accuracy.

Therefore, in the present invention, in view of the above-mentioned problems in the prior art, that is, the purpose is to put the phase modulation into practical use without degrading the address detection accuracy even when the phase modulation is applied to the address of the optical disk. An object is to provide an optical disk device capable of detecting the address with high accuracy.

[0009]

In order to achieve the above object, it is necessary to make the phases of the modulation signal and the reference signal the same depending on the frequency of the modulation signal. Therefore, in the present invention,
Pay attention to the phase shift between the modulated signal and the reference signal and the amplitude of the phase-detected signal. That is, according to the inventors, when the phase shift between the modulation signal and the reference signal becomes zero,
The phase-detected signal has the maximum amplitude. That is, the present invention is based on the recognition that the detection accuracy of the address becomes maximum if the evaluation amount is the signal amplitude of the phase-detected signal and the delay amount that maximizes it is obtained.

In order to realize this concretely, according to the present invention, first, an optical disc having a groove meandering at a constant frequency and having a phase-modulated address is irradiated with a light spot to read information. An optical disk recording / reproducing apparatus for recording / reproducing, comprising: a phase detection means for detecting a wobble signal from the reflected light of the light spot to generate an address; and a means for generating a timing signal delayed from the wobble signal. Further, in order to variably control the address detection accuracy in the phase detection means, there is proposed an optical disk recording / reproducing apparatus including a control unit for controlling the delay amount in the delayed timing signal generation means. is there.

In the present invention, the optical disk recording / recording
The reproducing apparatus further comprises means for detecting the amplitude of the phase detection signal from the phase detection means, and the control section determines the delayed timing based on the amplitude of the phase detection signal from the amplitude detection means. It is preferable to control the delay amount in the signal generating means, and therefore, in the optical disc recording / reproducing apparatus, further, in the optical disc recording / reproducing apparatus, the control section is arranged such that the amplitude of the phase detection signal from the amplitude detecting means exhibits a maximum value. It is preferable to control the delay amount in the delayed timing signal generating means.

Further, in the present invention, in order to achieve the above-mentioned object, it is further meandered at a constant frequency, and
In an optical disk recording / reproducing apparatus for irradiating a light spot on an optical disk having a groove whose address is phase-modulated to record / reproduce information, an address detection for detecting a wobble signal from the reflected light of the light spot to generate an address A method for detecting a wobble signal to generate a phase detection signal, generating a timing signal delayed from the wobble signal, and variably controlling address detection accuracy by phase detection of the wobble signal, An address detection method for an optical disc recording / reproducing apparatus that controls the delay amount of a delayed timing signal has been proposed.

According to the present invention, there is provided the address detecting method for the optical disk recording / reproducing apparatus, further comprising detecting the amplitude of the phase detection signal and detecting the amplitude of the detected phase detection signal. Controlling the delay amount of the delayed timing signal based on the above, and further controlling the delay amount of the delayed timing signal in a direction in which the amplitude of the detected phase detection signal shows the maximum value. It is preferable.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

First, an example of a so-called disc-shaped optical disc structure which is a recording medium used in an optical disc recording / reproducing apparatus according to an embodiment of the present invention will be described with reference to FIG. It should be noted that FIG. 1 is a partially enlarged view showing a part of a disk-shaped optical disc, which is usually enlarged.
In this figure, the track originally provided in an arc shape on the optical disk is shown in an enlarged linear form (extending in the lateral direction in the figure).

That is, as is apparent from FIG. 1, the groove 12 which is a guide groove is formed on the optical disk 10.
, Meanders at a constant frequency, and the address is phase-modulated. The modulation shown in the figure is "0.
This is performed in two phases of "degree" and "180 degrees", which is generally called a BPSK (Binary Phase Shift Keying) method. That is, in the groove 12 in this figure, the portion indicated by the reference numeral 13 corresponds to the portion indicating the data "0" of the modulation "0 degree", while the part indicated by the reference numeral 14 indicates a part of the groove. , Which corresponds to the data “1” of the modulation “180 degrees”. That is, this optical disc adopts phase modulation as an addressing method.

Next, an embodiment of the present invention will be described in which information is recorded and / or recorded information is reproduced on the above-mentioned optical disc, that is, an optical disc in which phase modulation is applied to the address system of the optical disc. The other specific configuration of the optical disc apparatus and the address detecting method therefor will be described in detail below.

First, in order to achieve the above-mentioned object of the present invention, it is necessary to make the phases of the modulation signal and the reference signal the same in accordance with the fluctuating frequency of the modulation signal. Therefore,
The present invention focuses on the phase shift between the modulated signal and the reference signal and the amplitude of the phase-detected signal. That is, when the phase shift between the modulation signal and the reference signal is zero (0), the amplitude of the phase-detected signal becomes maximum. In other words, the phase detected signal amplitude is obtained as the evaluation amount,
By obtaining the delay amount that maximizes this signal amplitude, the phase shift between the modulation signal and the reference signal is minimized,
That is, it is possible to maximize the address detection accuracy.

Therefore, in the present invention, based on the above consideration by the inventors, in order to specifically realize this, an example of a specific configuration of the optical disk recording / reproducing apparatus according to the embodiment of the present invention will be described. It is shown in the attached FIG.

In FIG. 2, an optical head 20 composed of, for example, a semiconductor laser or the like is provided below the optical disc 10 which is a medium for recording / reproducing information by this apparatus.
However, it is arranged so as to be freely movable in the radial direction of the optical disc by a driving device (not shown). It should be noted that this optical disc 10 is rotatably driven by a rotation driving device (not shown) in a state where it is mounted in this device, as in the conventional optical disc recording / reproducing device.

The optical head 20 is the optical disc 1 described above.
A light spot is irradiated on the lower surface of 0, the reflected light reflected by the irradiation is detected by a known detector, and the wobble signal 22 is detected from this reflected light. The wobble signal 22 from the optical head 20 is, on the one hand, B
It is input to the phase detection circuit 44 via a PF (band pass filter) circuit A24. On the other hand, the wobble signal 22 from the optical head 20 is transmitted to the BPF circuit B28,
A clock extraction circuit 32, a timing signal generation circuit 36,
After passing through the delay circuit 40, the timing signal 42 is input to the other input end of the phase detection circuit 44.

The output of the phase detection circuit 44 is 2
It is input to the binarization circuit 54 and the decoder circuit 58. The decoding circuit 58 identifies the address 59 from the binarized signal 56 from the binarizing circuit 54, and transfers the address information to, for example, a control unit that controls the position of the optical head. The output of the phase detection circuit 44 is also input to the amplitude measurement circuit 60 at the same time. The amplitude measurement circuit 60 measures the amplitude of the phase detection signal 52 output from the phase detection circuit 44, and outputs the measured amplitude amount 68 to the controller 64. The controller 64 controls the delay amount of the delay circuit 40 based on the amplitude measurement value of the input phase detection signal 52 by the method described below, that is, the measured amplitude amount 68 becomes maximum. To control the delay amount.

As is clear from the above description, in the optical disk recording / reproducing apparatus of the present invention, first, from the wobble signal (modulation signal) obtained from the guide groove (groove) shown in FIG. A clock extraction circuit 32 for generating a clock signal 34 having a frequency N times that synchronized therewith is provided. Further, a timing signal 38 having the same period as this wobble signal is generated by the timing signal generation circuit 36 from the above clock signal.

The timing signal 38 is for controlling the phase detection circuit 44, and differs depending on the system of this phase detection circuit. Hereinafter, three types of phase detection circuits and timing signals corresponding thereto will be described.

First, the first phase detection circuit is a method of multiplying a sine wave, and the timing signal is a rectangular signal having the same period as the wobble signal. In this case, in order to convert this rectangular signal into a reference signal that is a sine wave, for example, as shown in FIG. 2 above, the BPF circuit 46 is multiplied by the wobble signal (modulation signal) and the reference signal. Multiplier 48
And an LPF (low pass filter) circuit 50 for smoothing the output of the multiplier.

The operation of the first phase detection circuit will be described in detail below with reference to the waveforms of the respective signals shown in FIG.

First, as described above, the optical head 20 irradiates a light spot on the optical disk 10 and detects the wobble signal 22 from the reflected light. The BPF circuit A24 generates a band-limited modulated signal 26 from the wobble signal 22 (see FIG. 3A). Further, the BPF circuit B28 and the clock extraction circuit 32 formed of, for example, a PLL circuit,
Although not shown, a clock signal 34 having a frequency N times that of the wobble signal is generated from the wobble signal 22.

Here, since the BPF circuit A24 needs to pass a signal band, it has a relatively wide band, while B
Since the PF circuit B28 needs to reduce noise,
Bandwidth is relatively narrow. Therefore, depending on the frequency of the wobble signal 22, the phase of the modulated signal 26 (FIG. 3A) that has passed through each BPF circuit and the signal 30 are deviated.

The timing signal generation circuit 36 generates a timing signal 38 from the above clock signal 34. The waveform of the timing signal 38 differs depending on the configuration of the phase detection circuit 44. That is, in the configuration shown in FIG. 2, the timing signal 38 is a rectangular signal having the same period as the wobble signal 22. In reality, the timing signal 38 is P
It is output from the LL circuit 32.

Further, in the delay circuit 40, the delay amount 66 is set by the controller 64, and the timing signal 38 is delayed for a predetermined time. The delay amount can be extremely easily realized by setting the cycle of the clock signal as the minimum unit. The delayed timing signal 42 (see FIG. 3B) becomes a sine wave in the BPF circuit C46 and is used as the reference signal 47 (see FIG. 3C).

Then, the multiplier 48 outputs the modulated signal 26
(FIG. 3A) is multiplied by the reference signal 47 (FIG. 3C) (see the multiplier signal 49 of FIG. 3D). And
The output of the multiplier 48 is smoothed by the LPF circuit 50,
An LPF circuit signal 52 which is a phase detection signal is obtained.

Thereafter, the binarizing circuit 54 binarizes the phase detection signal 52 to generate a binarizing signal 56, and the decoding circuit 58 identifies the address 59 from the binarizing signal 56, and as a result, obtains it. Optical disc recording /
As described above, the remanufacturing device positions the light spot at a predetermined address.

On the other hand, the amplitude measuring circuit 60 measures the amplitude of the phase detection signal 52 and outputs the amplitude amount 68 to the controller 64. An example of this amplitude is shown in FIG. In this figure, the value of the data “1” is defined as the amplitude with the value of the data “0” as the reference.
As another method, the value of data “0” or the value of data “1” may be defined as the amplitude.

As described above, according to the above configuration, the controller 64 can measure the amplitude 68 of the phase detection signal 52 with respect to the predetermined delay amount 66 output by the controller 64.

Next, FIG. 4 shows the relationship between the above delay amount and the amplitude of the phase detection signal. That is, if the phases are shifted, the amplitude of the phase detection signal decreases. In other words, the amplitude of the phase detection signal is centered on zero phase shift (0).
It decreases as the amount of delay increases in the positive and negative directions. Therefore, the controller 64 grasps or uses this characteristic, and sets the delay amount 66 in the delay circuit 40 at which the amplitude 68 of the phase detection signal 52 becomes maximum. As a result, it is possible to maintain the highest address detection accuracy.

Next, a method of using a signal selection circuit as the second phase detection circuit 44 'will be described with reference to the attached FIG. Note that FIG. 5 is an example in which the phase detection circuit 44 shown in FIG. 2 is changed to a system using a signal selection circuit. In this case, the timing signal is a signal instructing switching of the signal selection circuit. Further, as its configuration, an inverting circuit 70 for inverting the wobble signal, a signal selecting circuit 74 for selecting one of the wobble signal, the inverted wobble signal, and zero according to the timing signal, and the selected signal. An LPF circuit 78 for smoothing the signal is provided.

FIG. 6 shows the signal waveform of each part in the second phase detection circuit. First, the inverting circuit 70 operates the modulation signal 26, which is a wobble signal from the optical head 20.
Although not shown here, the inverted modulation signal 72 is generated from (see FIG. 6A). On the other hand, in the second phase detection circuit 44 ', the signal selection circuit 74 is responsive to the delayed timing signal 42 (see FIG. 6B).
The modulated signal 26 (FIG. 6A) and the inverted modulated signal 72
Then, one of them is selected from zero (0).

Here, the operation of the signal selection circuit 74 will be described.
This will be described using the waveform of the delay timing signal 42 shown in FIG. As is clear from the figure, the delay timing signal 42 repeats "1", "0", "-1", "0", while the signal selection circuit 74, as shown in FIG. Either the modulation signal 26, zero (“0”), or the inverted modulation signal 72 is selected. Then, the signal 76 (see FIG. 6C) selected by the signal selection circuit 74 is smoothed by the LPF circuit 78, and the phase detection signal (L
A PF circuit signal) 52 is obtained (see FIG. 6D).

Thus, the second phase detection circuit 4
4'is equivalent to approximating a sine wave as a reference signal to a ternary value with respect to the first phase detection circuit 44 shown in FIG. Although the signal selection circuit 74 is used according to the example shown in FIG. 5, it is possible for those skilled in the art to easily infer that the function is realized by two switches instead of the signal selection circuit 74. Let's do it. Further, although three values are used in this example, however, the present invention is not limited to this, and it is also possible to omit two (0) from the three values and realize a binary value. Those skilled in the art can easily analogize.

Finally, the third phase detection circuit 44 "is
This is a system using a D converter. In this method, the timing signal is a signal instructing AD conversion. That is, as shown in the attached FIG. 7, an AD converter 80 that converts a wobble signal into a digital value in accordance with a timing signal, and an arithmetic unit 84 that multiplies the converted digital value by -1 every other conversion. Then, a digital filter 88 for smoothing the output of this arithmetic unit is provided. As a result, the timing signal is delayed by the delay circuit 40 (see FIG. 2).
Amplitude measuring circuit 60 (refer to FIG. 2) that causes a phase difference between the modulated signal and the reference signal, and at the same time measures the signal phase-detected by the third phase detecting circuit 44 "by delaying with The amplitude is measured in accordance with the delay amount by providing the above-mentioned structure, that is, according to the above-described configuration, it is possible to obtain the delay amount that maximizes the amplitude of the phase-detected signal, similarly to the above.

The third phase detection circuit 4 shown in FIG.
4 ″ is, more specifically, the phase detection circuit 44 of FIG.
Is an example in which is changed to a system using an AD converter. Regarding the operation, FIG. 8 attached shows the signal waveform of each part.

First, the AD converter 80 responds to the delay timing signal 42 to generate the modulated signal 26 (see FIG. 8A).
Is converted into a digital value 82 (see FIG. 8B). Then, the calculator 84 converts the converted digital value 82 (see FIG. 8).
(B)) is multiplied by -1 every other conversion (see the calculator signal 86 in FIG. 8C). The calculator signal 8 which is the calculation output
6 is smoothed by the m digital filter 88, and the phase detection signal (see the LPF circuit signal of FIG. 8D) 52 is obtained.

As described above, according to the optical disk recording / reproducing apparatus of the present invention, the controller 64 responds to the set delay amount while the phase detecting circuits 44, 4 and 4 are operated.
By measuring the amplitude of the detection signal from 4'44 ", the delay amount that maximizes the amplitude is obtained, and this makes it possible to maintain the address detection accuracy sufficiently high.

Subsequently, the recorded information is read by the optical disk recording / reproducing apparatus according to the present invention, and / or
The relationship with the above optical disc on which information will be written will be described below.

First, in the CAV system, generally, the modulation frequency of the optical spot changes depending on the radial position of the optical disc on which the light spot is located. Therefore, such C
When recording / reproducing an AV type optical disc, a delay amount is previously set at a typical position on the optical disc, for example, at the inner circumference of the disc, the middle circumference of the disc, or the outer circumference of the disc by using the above method. It is conceivable that the controller 64 of the apparatus sets the delay amount according to the position of the light spot (the position of the optical head 20, etc.) in advance. Further, in order to further improve the accuracy, for example, the above-mentioned measurement positions are increased (the delay amount is obtained in advance at the above-mentioned three or more positions), or the innermost circumference and the outermost circumference of the disc are preliminarily measured. It is also possible to use so-called linear interpolation, in which the delay amount is calculated and the delay amount therebetween is calculated in proportion to the position of the light spot. According to this, the controller can set the delay amount according to the position of the light spot and perform highly accurate address detection.

As for the rotation control method of the optical disk, in addition to the CAV method described above, ZCAV (Zoned Constant)
The linear velocity method is known and is in practical use. The ZCAV system is a system in which recording is performed at the same data rate by dividing into zones (for example, 17 in the innermost circumferential zone and 41 in the outermost circumferential zone) in which the number of sectors is different at the radial position, and the rotation control is performed for each zone. In particular, it is a method that can realize high-density recording, easy rotation control, and signal writing.

When performing recording / reproducing of such a ZCAV type optical disc, the controller of the optical disc recording / reproducing apparatus obtains a delay amount in advance for each zone, and delays it according to the position of the light spot. By setting the amount, it is possible to perform highly accurate address detection. Alternatively, it is also possible to collectively obtain the delay amount for each of a plurality of adjacent zones and set the delay amount according to the position of the light spot.

As described above, according to the optical disk recording / reproducing apparatus of the embodiment of the present invention, the light spot is positioned on the optical disk having the groove meandering at a constant frequency and having the address phase-modulated. An optical disk device, which irradiates a light spot on the optical disk,
An optical head for detecting a wobble signal from reflected light, a clock extraction circuit for generating a clock signal of N times frequency synchronized with the wobble signal from the wobble signal, and a timing signal generation circuit for generating a timing signal from the clock signal,
A delay circuit that delays the timing signal, a phase detection circuit that performs phase detection from the wobble signal using the timing signal, and a binarization circuit that generates a binarized signal that binarizes the phase detected signal. And a decoding circuit for identifying an address from a binarized signal, an amplitude measuring circuit for measuring the amplitude of the phase-detected signal, and a controller for setting a delay amount in the delay circuit that maximizes the amplitude of the phase-detected signal. There is provided an optical disc recording / reproducing apparatus provided with.

In addition, recording / recording of the optical disk having the above-mentioned structure
In the reproducing apparatus, it is preferable that the controller changes the delay amount according to the radial position of the optical disc on which the light spot is positioned. Further, in the optical disc recording / reproducing apparatus having the above configuration, the phase detection circuit is A BPF circuit that converts a signal into a reference signal, a multiplier that multiplies a wobble signal and a reference signal, and an LPF circuit that smoothes the output of the multiplier can be used. Also,
In the optical disc recording / reproducing apparatus having the above configuration,
The phase detection circuit includes an inverting circuit that inverts a wobble signal, a signal selection circuit that selects either a wobble signal, an inverted wobble signal, or zero according to a timing signal,
An LPF circuit for smoothing the selected signal is used, or the phase detection circuit has an AD converter for converting the wobble signal into a digital value according to the timing signal and the converted digital value every other conversion. It is also possible to include a computing unit that multiplies by −1 and a digital filter that smoothes the output of the computing unit.

[0050]

As is apparent from the above detailed description, according to the present invention, it is possible to adopt phase modulation as an address system of an optical disk, and particularly, to record or record on an optical disk that adopts the address of the phase modulation. Provided is an optical disk recording / reproducing apparatus capable of address detection accuracy reduction at the time of reproduction and capable of address detection with a practically applicable accuracy, and an address detecting method therefor. It becomes possible.

[Brief description of drawings]

FIG. 1 is an enlarged perspective view illustrating an example of a disc-shaped optical disc structure which is a recording medium used in an optical disc recording / reproducing apparatus according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a schematic configuration of an optical disc recording / reproducing apparatus according to an embodiment of the present invention.

FIG. 3 is a waveform diagram showing signal waveforms in respective parts of the optical disc recording / reproducing apparatus shown in FIG. 2 for explaining the operation thereof.

FIG. 4 is a diagram showing a relationship between a delay amount and an amplitude of a phase detection signal in the optical disc recording / reproducing apparatus.

FIG. 5 is a circuit diagram showing a circuit configuration of a second phase detection circuit in the optical disk recording / reproducing apparatus shown in FIG. 2, particularly regarding the phase detection circuit thereof.

FIG. 6 is a waveform diagram showing signal waveforms at respective portions in order to explain the operation of the phase detection circuit shown in FIG.

7 is a circuit diagram showing a circuit configuration of a second phase detection circuit of the phase detection circuit of the optical disc recording / reproducing apparatus shown in FIG.

FIG. 8 is a waveform diagram showing signal waveforms at respective parts for explaining the operation of the phase detection circuit shown in FIG.

[Explanation of symbols]

10 optical disc 12 grooves 20 optical head 22 Wobble signal 24 BPF circuit A 26 Modulation signal 28 BPF circuit B 32 clock extraction circuit 34 clock signal 36 Timing signal generation circuit 38 Timing signal 40 delay circuit 42 Delayed timing signal 44, 44 ', 44 "phase detection circuit 46 BPF circuit C 47 reference signal 48 multiplier 50 LPF circuit 52 Phase detection signal 54 Binarization circuit 58 Decoding circuit 59 addresses 60 Amplitude measurement circuit 64 controller 66 Delay amount 68 Amplitude 70 Inversion circuit 74 Signal selection circuit 78 LPF circuit 80 AD converter 84 arithmetic unit 88 Digital Filter

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Yu Nagai             292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa             Ceremony Hitachi Digital Media Development             In headquarters (72) Inventor Hiroshi Hirayama             292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa             Ceremony Hitachi Digital Media Development             In headquarters (72) Inventor Misuzu Mochizuki             292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa             Ceremony Hitachi Digital Media Development             In headquarters F term (reference) 5D090 AA01 CC12 DD03 EE13 FF50                       GG03 GG27

Claims (6)

[Claims] 1. An optical disk recording / reproducing apparatus for recording / reproducing information by irradiating a light spot on an optical disk having a groove meandering at a constant frequency and having an address phase modulated. It comprises a phase detection means for detecting a wobble signal from the reflected light of the wobble signal to generate an address, and a means for generating a timing signal delayed from the wobble signal. Further, the address detection accuracy in the phase detection means is made variable. An optical disk recording / reproducing apparatus comprising a control unit for controlling a delay amount in the delayed timing signal generating means for controlling. 2. The optical disk recording / reproducing apparatus according to claim 1, further comprising means for detecting the amplitude of the phase detection from the phase detection means, wherein the control section has the amplitude detection means. An optical disc recording / reproducing apparatus characterized in that the delay amount in the delayed timing signal generating means is controlled based on the amplitude of the phase detection signal from. 3. The optical disk recording / reproducing apparatus according to claim 2, wherein the control section causes the delayed timing signal generating means in a direction in which the amplitude of the phase detection signal from the amplitude detecting means exhibits a maximum value. An optical disk recording / reproducing apparatus characterized by controlling a delay amount in the optical disc. 4. An optical disk recording / reproducing apparatus for recording / reproducing information by irradiating a light spot on an optical disk having a groove meandering at a constant frequency and having an address phase-modulated to reflect the light spot. An address detection method of detecting a wobble signal from light to generate an address, wherein the wobble signal is detected to generate a phase detection signal, and a timing signal delayed from the wobble signal is generated to generate an address. An address detecting method for an optical disk recording / reproducing apparatus, characterized in that a delay amount of the delayed timing signal is controlled in order to variably control address detection accuracy by phase detection. 5. The address detecting method for an optical disk recording / reproducing apparatus according to claim 4, further comprising detecting an amplitude of the phase detection signal, and detecting the amplitude of the detected phase detection signal. An address detection method for an optical disk recording / reproducing apparatus, characterized in that the delay amount of the delayed timing signal is controlled based on the above. 6. The address detecting method for an optical disk recording / reproducing apparatus according to claim 5, wherein the delay amount of the delayed timing signal is a maximum value of the amplitude of the detected phase detection signal. An address detection method for an optical disk recording / reproducing apparatus, characterized by controlling in the indicated direction.