JP2004079130A - Device for detecting wobble signal period - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wobble signal period detecting device for shortening a period until a wobble signal period detection result is stabilized after the movement of a laser pickup in a radial direction. <P>SOLUTION: While the laser pickup moves in the radial direction of an optical disk, a normalization circuit 5 receives a moving period signal of the laser pickup and stops an operation. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an optical disk recording / reproducing apparatus, and more particularly to a wobble signal cycle detecting apparatus.
[0002]
[Prior art]
Optical discs (hereinafter, simply referred to as discs) such as CD-R, CD-RW, DVD-R, and DVD-RW are provided with grooves for recording guides called grooves. The grooves meander finely in a constant rule in the radial direction, and this is called wobbling.
[0003]
In optical disk recording by the CLV (Constant Linear Velocity; constant linear velocity) control method, the rotation of the disk is performed so that the period of a wobble signal read from the disk is a desired period while the recording data rate period is fixed. Control the speed.
[0004]
Also, in disk recording by the CAV (Constant Angular Velocity; constant rotation angle) control method, the period of the recording data rate is set so that the period of the wobble signal read from the disk and the period of the recording data rate become a desired ratio. Control.
[0005]
As described above, in both methods, it is necessary to detect the period of the wobble signal.
[0006]
FIG. 12 shows the configuration of a conventional wobble signal cycle detection device.
[0007]
In CD-R and CD-RW, a wobble signal is frequency-modulated by disk information necessary for recording. The binarization circuit 101 binarizes the wobble signal.
[0008]
The edge interval measuring circuit 103 measures an edge interval of the binarized wobble signal. By averaging the measurement results, the averaging circuit 105 removes disturbance due to a scratch on the disk or vibration of the optical disk recording / reproducing apparatus, and at the same time, obtains wobble signal cycle information.
[0009]
The wobble signal in DVD-R and DVD-RW has a single frequency. The binarization circuit 101 binarizes the wobble signal.
[0010]
The edge interval measuring circuit 103 measures an edge interval of the binarized wobble signal. By averaging the measurement results, the averaging circuit 105 removes disturbance due to a scratch on the disk or vibration of the optical disk recording / reproducing apparatus, and at the same time, obtains wobble signal cycle information.
[0011]
FIG. 13 shows an operation up to the start of recording in the wobble signal cycle detection device shown in FIG.
[0012]
First, the laser pickup (PU) is moved in the radial direction from the track at which recording is started to a position that is retroactive to the desired number of tracks. Since the laser pickup crosses the track, an indefinite wobble signal is input while the laser pickup is moving, and the detection result of the wobble signal period is disturbed.
[0013]
Next, the movement ends when the laser pickup reaches a desired position. At this time, since the linear velocity changes due to the movement of the laser pickup, the wobble signal period after the movement has a different value from that before the movement, and the detection result of the wobble signal period detection device is disturbed by the indefinite wobble signal. From the state, it converges to the wobble signal cycle after the movement.
[0014]
Next, when the laser pickup reaches a position where recording is started, recording on the disc is started. If the detection result of the wobble signal cycle does not converge to the wobble signal cycle of the disc by the time recording starts, the data is recorded at the correct position on the disc because the disc linear velocity does not match the recording data rate. I can't.
[0015]
[Problems to be solved by the invention]
In the conventional optical disk recording / reproducing apparatus, it is necessary to consider the time until the wobble signal period obtained by the wobble signal period detecting device shown in FIG. 12 converges to the disk wobble signal period after the laser pickup is moved. The moving position of the laser pickup before the start of the recording is set to a position sufficiently dating from the position where the recording is started.
[0016]
However, this method has a problem that the time from the movement of the laser pickup in the radial direction to the start of recording becomes long.
[0017]
SUMMARY OF THE INVENTION It is an object of the present invention to provide a wobble signal cycle detection device capable of shortening a period until a wobble signal cycle detection result is stabilized after a laser pickup is moved in a radial direction of an optical disk.
[0018]
[Means for Solving the Problems]
(First Solution)
The wobble signal period detecting device of the present invention comprises:
A binarization circuit for binarizing the wobble signal;
An edge interval measuring circuit for measuring an edge interval of the binarized wobble signal;
An averaging circuit for averaging the measurement results of the edge interval measurement circuit,
The operation of the averaging circuit is stopped while the laser pickup is moving in the radial direction of the optical disk.
[0019]
(Second solution)
The wobble signal period detecting device of the present invention comprises:
A binarization circuit for binarizing the wobble signal;
An edge interval measuring circuit for measuring an edge interval of the binarized wobble signal;
A switch having a first input terminal connected to an output terminal of the edge interval measurement circuit;
An averaging circuit connected to a selector of the switch,
A second input terminal of the switch is connected to an output terminal of the averaging circuit;
In normal operation, the selector of the switch selects the first input terminal, and the switch selects the second input terminal while the laser pickup is moving in the radial direction of the optical disk. It is characterized by.
[0020]
(Third solution)
The wobble signal period detecting device of the present invention comprises:
A binarization circuit for binarizing the wobble signal;
An edge interval measuring circuit for measuring an edge interval of the binarized wobble signal;
A switch having a first input terminal connected to an output terminal of the edge interval measurement circuit;
An averaging circuit connected to a selector of the switch,
A second input terminal of the switch is supplied with a wobble signal cycle predicted value after the movement of the laser pickup,
In normal operation, the selector of the switch selects the first input terminal, and the switch selects the second input terminal while the laser pickup is moving in the radial direction of the optical disk. It is characterized by.
[0021]
(Fourth solution)
The wobble signal period detecting device of the present invention comprises:
A binarization circuit for binarizing the wobble signal;
An edge interval measuring circuit for measuring an edge interval of the binarized wobble signal;
An averaging circuit for averaging the measurement results of the edge interval measurement circuit,
In the case of normal operation, the averaging circuit performs a normal operation, and while the laser pickup is moving in the radial direction of the optical disc, presetting a wobble signal cycle predicted value after the movement of the laser pickup to the averaging circuit. It is characterized by.
[0022]
(Fifth solution)
The wobble signal period detecting device of the present invention comprises:
A binarization circuit for binarizing the wobble signal;
An edge interval measuring circuit for measuring an edge interval of the binarized wobble signal;
A first switch having a first input terminal connected to an output terminal of the edge interval measurement circuit;
An averaging circuit connected to the selector of the first switch;
An output of the averaging circuit is supplied to a first input terminal, a wobble signal cycle predicted value after movement of the laser pickup is supplied to a second input terminal, and a selector is a second switch of the first switch. A second switch connected to the input end of
In the case of normal operation, the selector of the first switch selects its own first input terminal, and the selector of the first switch is selected while the laser pickup is moving short in the radial direction of the optical disk. Selects its own second input terminal, and the selector of the second switch selects its own first input terminal, while the laser pickup is moving long in the radial direction of the optical disk. The selector of the first switch selects its own second input terminal, and the selector of the second switch selects its own second input terminal.
[0023]
BEST MODE FOR CARRYING OUT THE INVENTION
(First embodiment)
FIG. 1 shows the configuration of a first embodiment of the wobble signal period detecting device of the present invention.
[0024]
FIG. 2 shows an operation up to the start of recording in the wobble signal cycle detection device shown in FIG.
[0025]
At the time of normal operation, the same operation as that of the conventional technique is performed. This is described below.
[0026]
The binarization circuit 1 binarizes the wobble signal. The edge interval measuring circuit 3 measures the edge interval of the binarized wobble signal. By averaging the measurement results, the averaging circuit 5 removes disturbances due to scratches on the disk and vibrations of the optical disk recording / reproducing apparatus, and at the same time, obtains wobble signal period information.
[0027]
While the laser pickup is moving in the radial direction of the disk, the averaging circuit 5 stops receiving the supply of the movement period signal of the laser pickup. Thus, the averaging circuit 5 holds the wobble signal synchronization information detected by the laser pickup before the movement.
[0028]
After the movement of the laser pickup is completed, the averaging of the measurement results from the edge interval measurement circuit 3 is restarted.
[0029]
While the laser pickup is moving, the edge interval measurement result of the binarized wobble signal obtained by operating the edge interval measurement circuit 3 may be discarded, or the operation of the edge interval measurement circuit 3 may be stopped. good.
[0030]
In the wobble signal cycle detection device according to the present embodiment, the wobble signal cycle information detected by the wobble signal cycle detection device is disturbed because the indefinite wobble signal generated when the laser pickup crosses the track is not taken in as averaged data. There is nothing.
[0031]
If the movement distance of the laser pickup is short, the change in linear velocity is very small, so even if the distance between the movement position of the laser pickup and the recording start position is shortened, the wobble signal period detection device can obtain the signal after the movement of the laser pickup. The wobble signal period can converge to the wobble signal period of the disk.
[0032]
(Second embodiment)
FIG. 3 shows the configuration of a second embodiment of the wobble signal period detecting device of the present invention. FIG. 4 shows an operation up to the start of recording in the wobble signal cycle detection device shown in FIG.
[0033]
In the present embodiment, unlike the first embodiment, a switch 7 exists between the edge interval measuring circuit 3 and the averaging circuit 5. The input terminal 7 a of the switch 7 is connected to the output terminal of the edge interval measurement circuit 3. The input terminal 7 b of the switch 7 is connected to the output terminal of the averaging circuit 5.
[0034]
At the time of normal operation, the same operation as that of the conventional technique is performed. This is described below.
[0035]
The binarization circuit 1 binarizes the wobble signal. The edge interval measuring circuit 3 measures the edge interval of the binarized wobble signal. The selector 7c of the switch 7 selects the input terminal 7a of the switch 7. The averaging circuit 5 averages the measurement results from the edge interval measurement circuit 3 to remove disturbance due to scratches on the disk or vibration of the optical disk recording / reproducing device, and obtain wobble signal period information.
[0036]
While the laser pickup is moving in the radial direction of the disc, the selector 7c of the switch 7 receives the supply of the movement period signal of the laser pickup and selects the input terminal 7b of the switch 7. Thus, the averaging circuit 5 holds the wobble signal synchronization information detected by the laser pickup before the movement.
[0037]
After the movement of the laser pickup is completed, the averaging of the measurement results from the edge interval measurement circuit 3 is restarted.
[0038]
While the laser pickup is moving, the edge interval measurement result of the binarized wobble signal obtained by operating the edge interval measurement circuit 3 may be discarded, or the operation of the edge interval measurement circuit 3 may be stopped. good.
[0039]
In the wobble signal cycle detection device according to the present embodiment, the wobble signal cycle information is not disturbed because an indefinite wobble signal generated when the laser pickup crosses the track is not taken in as averaged data.
[0040]
If the movement distance of the laser pickup is short, the change in linear velocity is very small, so even if the distance between the movement position of the laser pickup and the recording start position is shortened, the wobble signal period detection device can obtain the signal after the movement of the laser pickup. The wobble signal period can converge to the wobble signal period of the disk.
[0041]
(Third embodiment)
FIG. 5 shows the configuration of a third embodiment of the wobble signal period detection device of the present invention. FIG. 6 shows an operation up to the start of recording in the wobble signal cycle detection device shown in FIG.
[0042]
In the present embodiment, unlike the second embodiment, a wobble signal cycle predicted value after the movement of the laser pickup is supplied to the input terminal 7b of the switch 7.
[0043]
At the time of normal operation, the same operation as that of the conventional technique is performed. This is described below.
[0044]
The binarization circuit 1 binarizes the wobble signal. The edge interval measuring circuit 3 measures the edge interval of the binarized wobble signal. The selector 7c of the switch 7 selects the input terminal 7a of the switch 7. The averaging circuit 5 averages the measurement results from the edge interval measurement circuit 3 to remove disturbance due to scratches on the disk or vibration of the optical disk recording / reproducing device, and obtain wobble signal period information.
[0045]
While the laser pickup is moving in the radial direction of the disc, the selector 7c of the switch 7 receives the supply of the movement period signal of the laser pickup and selects the input terminal 7b of the switch 7. Thereby, the averaging circuit 5 averages the wobble signal cycle predicted value after the movement of the laser pickup.
[0046]
After the movement of the laser pickup is completed, the averaging of the measurement results from the edge interval measurement circuit 3 is restarted.
[0047]
In the optical disk recording by the CAV control method, the rotation period of the disk is almost constant, so that the period of the wobble signal can be predicted from the radius between the track position of the laser pickup and the center of the disk.
[0048]
As described above, while the laser pickup is moving in the radial direction of the disk, the input value of the averaging process is switched from the measurement result of the wobble signal period to the predicted value of the wobble signal period after the movement of the laser pickup, and the averaging process is performed. The wobble signal cycle information is derived to a predicted value of the wobble signal cycle after the laser pickup is moved.
[0049]
After the movement of the laser pickup is completed, the wobble signal period information may be converged by the prediction error of the wobble signal period after the movement of the laser pickup, so that the time until the convergence can be reduced.
[0050]
While the laser pickup is moving, the edge interval measurement result of the binarized wobble signal obtained by operating the edge interval measurement circuit 3 may be discarded, or the operation of the edge interval measurement circuit 3 may be stopped. good.
[0051]
Further, since an indeterminate wobble signal generated when the laser pickup crosses the track is not taken in as averaged data, the wobble signal period information is not disturbed.
[0052]
(Fourth embodiment)
FIG. 7 shows the configuration of a fourth embodiment of the wobble signal period detection device of the present invention. FIG. 8 shows an operation up to the start of recording in the wobble signal cycle detection device shown in FIG.
[0053]
In this embodiment, the wobble signal period prediction value after the movement of the laser pickup is preset in the averaging circuit 5a during the movement of the laser pickup in the radial direction. During the movement of the laser pickup, the output of the averaging circuit 5a is forcibly set as the wobble signal cycle prediction value.
[0054]
At the time of normal operation, the same operation as that of the conventional technique is performed. This is described below.
[0055]
The binarization circuit 1 binarizes the wobble signal. The edge interval measuring circuit 3 measures the edge interval of the binarized wobble signal. By averaging the measurement results, the averaging circuit 5a removes disturbance due to scratches on the disk or vibrations of the optical disk recording / reproducing apparatus, and obtains wobble signal cycle information.
[0056]
After the movement of the laser pickup is completed, the averaging of the measurement results from the edge interval measurement circuit 3 is restarted.
[0057]
While the laser pickup is moving, the edge interval measurement result of the binarized wobble signal obtained by operating the edge interval measurement circuit 3 may be discarded, or the operation of the edge interval measurement circuit 3 may be stopped. good.
[0058]
In the optical disk recording by the CAV control method, the rotation period of the disk is almost constant, so that the period of the wobble signal can be predicted from the radius between the track position of the laser pickup and the center of the disk.
[0059]
After the movement of the laser pickup is completed, the wobble signal period information may be converged by the prediction error of the wobble signal period after the movement of the laser pickup, so that the time until the convergence can be reduced.
[0060]
Further, since an indeterminate wobble signal generated when the laser pickup crosses the track is not taken in as averaged data, the wobble signal period information is not disturbed.
[0061]
(Fifth embodiment)
FIG. 9 shows the configuration of the fifth embodiment of the wobble signal period detecting device of the present invention.
[0062]
A configuration that is different from the above embodiment will be described. While the laser pickup is moving in the radial direction of the disk, the input end 9a of the switch 9 is supplied with a predicted wobble signal cycle value after the movement of the laser pickup. The output of the averaging circuit is supplied to the input terminal 9b of the switch 9.
[0063]
When the movement distance of the laser pickup is short, the selector 9c of the switch 9 selects the input terminal 9b in response to the result of the determination of the movement distance of the laser pickup. When the moving distance of the laser pickup is long, the selector 9c of the switch 9 selects the input terminal 9a in response to the result of the judgment of the moving distance of the laser pickup.
[0064]
The output of the switch 9 is supplied to an input terminal 7b of the switch 7. The input terminal 7 a of the switch 7 is connected to the output terminal of the edge interval measurement circuit 3.
[0065]
The selector 7c of the switch 7 selects the input terminal 7b while receiving the movement period signal of the laser pickup indicating the movement of the laser pickup in the radius method.
[0066]
In the case of normal operation, the selector 7c of the switch 7 selects the input terminal 7a.
[0067]
At the time of normal operation, the same operation as that of the conventional technique is performed. This is described below.
[0068]
The binarization circuit 1 binarizes the wobble signal. The edge interval measuring circuit 3 measures the edge interval of the binarized wobble signal. The selector 7c of the switch 7 selects the input terminal 7a of the switch 7. The averaging circuit 5 averages the measurement results from the edge interval measurement circuit 3 to remove disturbance due to scratches on the disk or vibration of the optical disk recording / reproducing device, and obtain wobble signal period information.
[0069]
In the optical disk recording by the CAV control method, since the rotation period of the disk is almost constant, the period of the wobble signal can be predicted from the radius between the track position of the laser pickup and the center of the disk. An error occurs.
[0070]
FIG. 10 shows the operation of the apparatus for detecting the period of the wobble signal shown in FIG. 9 until the start of recording when the moving distance of the laser pickup is short. While the laser pickup is moving, the averaging circuit 5 holds the wobble signal cycle information detected before the movement because the output is input. When the moving distance of the laser pickup is short, the change in the linear velocity due to the movement of the laser pickup is very small, so that the time until the detection result of the wobble signal period converges is short.
[0071]
FIG. 11 shows the operation of the apparatus for detecting the period of the wobble signal shown in FIG. 9 until the start of recording when the moving distance of the laser pickup is long. While the laser pickup is moving, the wobble signal cycle information by the averaging process is derived to a predicted value of the wobble signal cycle after the movement of the laser pickup. After the movement of the laser pickup is completed, the wobble signal period information may be converged by the prediction error of the wobble signal period after the movement of the laser pickup, so that the time until the convergence can be reduced.
[0072]
In both cases, an indeterminate wobble signal generated when the laser pickup crosses the track is not taken in as averaged data, so that the wobble signal period information is not disturbed.
[0073]
While the laser pickup is moving, the edge interval measurement result of the binarized wobble signal obtained by operating the edge interval measurement circuit 3 may be discarded, or the operation of the edge interval measurement circuit 3 may be stopped. good.
[0074]
【The invention's effect】
According to the wobble signal cycle detection device of the present invention, it is possible to shorten the period until the wobble signal cycle detection result becomes stable after the laser pickup moves in the radial direction of the optical disc.
[0075]
Further, according to the wobble signal cycle detecting device of the present invention, even when the moving distance of the laser pickup in the radial direction of the optical disk is large, the period until the wobble signal cycle detection result becomes stable after the movement of the laser pickup can be shortened.
[Brief description of the drawings]
FIG. 1 is a diagram showing a configuration of a first embodiment of a wobble signal period detection device according to the present invention.
FIG. 2 is a diagram showing an operation up to the start of recording in the wobble signal cycle detection device shown in FIG.
FIG. 3 is a diagram showing a configuration of a second embodiment of the wobble signal period detection device of the present invention.
FIG. 4 is a diagram showing an operation up to the start of recording in the wobble signal cycle detection device shown in FIG. 3;
FIG. 5 is a diagram showing a configuration of a third embodiment of a wobble signal period detection device according to the present invention.
6 is a diagram showing an operation up to the start of recording in the wobble signal cycle detection device shown in FIG.
FIG. 7 is a diagram showing the configuration of a fourth embodiment of the wobble signal period detection device of the present invention.
8 is a diagram showing an operation up to the start of recording in the wobble signal cycle detection device shown in FIG. 7;
FIG. 9 is a diagram showing a configuration of a fifth embodiment of the wobble signal period detection device of the present invention.
FIG. 10 is a diagram illustrating an operation up to the start of recording when the movement distance of the laser pickup is short in the wobble signal cycle detection device illustrated in FIG. 9;
FIG. 11 is a diagram showing an operation up to the start of recording when the movement distance of the laser pickup is long in the wobble signal cycle detection device shown in FIG. 9;
FIG. 12 is a diagram illustrating a configuration of a conventional wobble signal period detection device.
FIG. 13 is a diagram showing an operation up to the start of recording in the wobble signal cycle detection device shown in FIG.
[Explanation of symbols]
1 ··· binarization circuit, 3 ··· edge interval measurement circuit, 5, 5a ··· averaging circuit, 7, 9 ··· switch.

Claims (5)

A binarization circuit for binarizing the wobble signal;
An edge interval measuring circuit for measuring an edge interval of the binarized wobble signal;
An averaging circuit for averaging the measurement results of the edge interval measurement circuit,
A wobble signal period detecting device, wherein the operation of the averaging circuit is stopped while the laser pickup is moving in the radial direction of the optical disk. A binarization circuit for binarizing the wobble signal;
An edge interval measuring circuit for measuring an edge interval of the binarized wobble signal;
A switch having a first input terminal connected to an output terminal of the edge interval measurement circuit;
An averaging circuit connected to a selector of the switch,
A second input terminal of the switch is connected to an output terminal of the averaging circuit;
In normal operation, the selector of the switch selects the first input terminal, and the switch selects the second input terminal while the laser pickup is moving in the radial direction of the optical disk. A wobble signal period detection device, characterized in that: A binarization circuit for binarizing the wobble signal;
An edge interval measuring circuit for measuring an edge interval of the binarized wobble signal;
A switch having a first input terminal connected to an output terminal of the edge interval measurement circuit;
An averaging circuit connected to a selector of the switch,
A second input terminal of the switch is supplied with a wobble signal cycle predicted value after the movement of the laser pickup,
In normal operation, the selector of the switch selects the first input terminal, and the switch selects the second input terminal while the laser pickup is moving in the radial direction of the optical disk. A wobble signal period detection device, characterized in that: A binarization circuit for binarizing the wobble signal;
An edge interval measuring circuit for measuring an edge interval of the binarized wobble signal;
An averaging circuit for averaging the measurement results of the edge interval measurement circuit,
In the case of normal operation, the averaging circuit performs a normal operation, and while the laser pickup is moving in the radial direction of the optical disc, presetting a wobble signal cycle predicted value after the movement of the laser pickup to the averaging circuit. A wobble signal period detection device, characterized in that: A binarization circuit for binarizing the wobble signal;
An edge interval measuring circuit for measuring an edge interval of the binarized wobble signal;
A first switch having a first input terminal connected to an output terminal of the edge interval measurement circuit;
An averaging circuit connected to the selector of the first switch;
An output of the averaging circuit is supplied to a first input terminal, a wobble signal cycle predicted value after movement of the laser pickup is supplied to a second input terminal, and a selector is a second switch of the first switch. A second switch connected to the input end of
In the case of normal operation, the selector of the first switch selects its own first input terminal, and the selector of the first switch is selected while the laser pickup is moving short in the radial direction of the optical disk. Selects its own second input terminal, and the selector of the second switch selects its own first input terminal, while the laser pickup is moving long in the radial direction of the optical disk. , The selector of the first switch selects its own second input terminal, and the selector of the second switch selects its own second input terminal. Signal period detection device.

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