JPH11161982A - Optical disk driving device and incidental information detecting circuit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To correctly detect incidental information even in the unrecorded area of an optical disk by allowing a first detecting means to adjust gains so that RF signal AC amplitudes of two light receiving elements divided in the tangential direction of a track become constant and detecting incidental information with the difference of both signals and allowing a second detecting means to detect the difference between the both signals while normalizing the sum signal of the light receiving elements. SOLUTION: In a first wobble signal calculating circuit 8a, only high frequency components of outputs are passed by a first high-pass filter 21 and a second high-pass filter 24 and the gain of a first VCA circuit 22 and the gain of a second VCA circuit 25 are respectively controlled by a first AGC circuit for RF signal 23 and a second AGC circuit for RF signal 26. The output of the first VCA circuit 22 and the output of the second VCA circuit 25 are subtracted by a first subtracting circuit 27 and incidental information are detected from the difference between both output signals. In a second wobble signal calculating circuit 8b, the sum signal outputs of current- voltage conversions are calculated in an adder circuit 33 and it is controlled so as to become constant.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disk drive for detecting additional information such as an address of an optical disk recorded in a wobble groove in a tracking groove, and more particularly to an optical disk drive capable of detecting additional information of an optical disk appropriately and accurately. Optical disk drive device and additional information detection circuit.

[0002]

2. Description of the Related Art In general, in an optical disk, tracking information is recorded by wobbling a tracking groove. In the case of detecting incidental information from the optical disk, a method of detecting the incidental information from a difference between outputs of light receiving elements for detecting a track error signal is generally widely used. However, in this detection method, if there is an imbalance in the amount of light incident on the light-receiving element for track detection, common-mode noise cannot be sufficiently removed when a difference between the outputs of the two is taken.
There is a problem that the additional information cannot be accurately detected. That is, when there is no imbalance in the amount of light incident on the light receiving element for track detection, the removal ratio of common-mode noise is sufficiently large, so that it is possible to accurately detect the incidental information. However, if the light amount becomes unbalanced, a required common-mode noise removal ratio cannot be obtained, and it becomes difficult to perform accurate detection.

[0003] Such a problem is particularly encountered in an optical disc such as a CD-R medium or a CD-RW medium which records or reproduces data depending on the intensity of reflected light.
Appears remarkably when incidental information is detected in a recorded area. In the detection of the incidental information, it is needless to say that it is desirable to adjust the optical system so that there is no imbalance in the light amount, but there is a limit to the mechanical adjustment, and there is a limit to the change over time and the media. It is difficult to cope with an imbalance that is acquired by warpage or the like.

Therefore, as one conventional method for solving these problems and enabling accurate detection of incidental information, an RF signal is obtained from a sum signal of two light receiving elements divided in a track tangential direction. A method has been proposed in which the outputs of the two light receiving elements are respectively normalized by the RF signal, and incidental information is detected from the difference between the normalized signals (for example, Japanese Unexamined Patent Publication No. Hei 6 (1994)).
-290462). According to this method, the CD-R
With respect to a recorded area of a medium or a CD-RW medium, the accompanying information can be detected accurately. Further, another conventional detection device includes an offset to an output of a position sensor of an objective lens to change a relative positional relationship between the objective lens and an optical axis, thereby obtaining a track signal output from a track signal calculation circuit. An apparatus for removing asymmetry of a signal has also been proposed (for example, Japanese Patent Application Laid-Open No.
-63078).

[0005]

As described in the prior art, when detecting supplementary information from an optical disc,
A method for detecting a track error signal based on a difference between outputs of light receiving elements has been widely adopted. In addition, as one method for accurately detecting the incidental information, an RF signal is obtained from a sum signal of two light receiving elements divided in a track tangential direction, and the outputs of the two light receiving elements are normalized by the RF signal. There has been proposed a method of detecting incidental information from a difference between the converted signals (Japanese Patent Laid-Open No. 6-290462). The method of detecting this incidental information includes CD-R media,
Although effective in a recorded area of a CD-RW medium, when ancillary information is detected in an unrecorded area, an RF signal cannot be obtained, so that an appropriate gain cannot be set. There is. Further, there is also known an apparatus which removes asymmetry of a track signal by giving an offset to an output of a position sensor of an objective lens and changing a relative positional relationship between the objective lens and an optical axis (see the above-mentioned Japanese Patent Application Laid-Open No. Hei 9 (1998)). -63078).
If this device is used, the asymmetry of the track signal can be removed, so that the incidental information can be detected accurately. However, since mechanical control is required to change the relative positional relationship, The configuration becomes complicated.

It is an object of the present invention to enable accurate detection of incidental information not only in a recorded area of an optical disc but also in an unrecorded area mainly by electrical control. 4 invention). Also, C
In a recorded area of a DR disc or a CD-RW disc, since the C / N (ratio of carrier to noise) of the wobble-recorded additional information is poor, even if the additional information cannot be reproduced, the additional information cannot be accurately read. It is an object of the present invention to enable accurate detection (the invention of claim 5). Furthermore, a drive device for recording / reproducing a CD-R medium has a CD-RW
It is an object of the present invention to enable accurate detection of incidental information even when recording on a medium.

[0007]

According to a first aspect of the present invention, there is provided an additional information detecting circuit for an optical disk drive, comprising two detecting means for detecting wobble-recorded additional information, wherein the first detecting means comprises a track tangent. The function of detecting incidental information from the difference between the two signals after adjusting the gain so that the RF amplitude of the RF signal of the two light receiving elements divided in the direction becomes constant. Has a function of normalizing and detecting the difference between the two light receiving elements obtained by the sum signal of the two light receiving elements, and a means for determining the type of the disk, and a means for determining whether the disk is recorded or unrecorded. And selecting means for selecting one of the first and second detecting means.

According to a second aspect of the present invention, there is provided an optical disk drive device provided with the additional information detecting circuit according to the first aspect, wherein when reproducing an unrecorded area of the disk, the second detecting means detects the same. The additional information recorded in the wobble is detected by the detecting means.

According to a third aspect of the present invention, there is provided an optical disk drive device including the additional information detecting circuit according to the first aspect, wherein the operation of detecting the additional information recorded by wobble is always performed by selecting the first detecting means during reproduction. Only when the supplementary information cannot be reproduced, the second detecting means is selected and detected.

According to a fourth aspect of the present invention, there is provided an optical disk drive device including the additional information detecting circuit according to the first aspect, and selects and detects the second detecting means when recording a disk.

According to a fifth aspect of the present invention, in the optical disk drive of the fourth aspect, the second detecting means is selected during recording by the write gate, and the first detecting means is selected except during recording. Before the start of recording, incidental information is detected by the first detecting means,
Using the write gate, the additional information recorded in the wobble recording at the same time as the recording is started is detected by the second detecting means.

According to a sixth aspect of the present invention, there is provided an optical disk drive for detecting incidental information of an optical disk wobble-recorded on a track by causing a light beam to follow a track on the optical disk. And a sample / hold stop means for accompanying information are provided. To detect the accompanying information at the time of recording on the CD-RW disc, the sample / hold is stopped and the attached information recorded by wobble is detected.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An optical disk drive and an additional information detecting circuit according to the present invention are provided with first and second two-dimensional information so as to enable accurate detection of additional information recorded by wobble.
It is characterized in that additional information detecting means (first and second detecting means) of various types are provided, and these two detecting means are switched and used according to the operation state of the drive. And
The first detecting means includes two tracks divided in the track tangential direction.
After the gain is adjusted so that the RF amplitudes of the RF signals of the two light receiving elements become constant, a function of detecting incidental information from the difference between the two signals (hereinafter, also appropriately referred to as a first detection method) is provided, and the second detection is performed. The means is provided with a function of detecting the difference between the two light receiving elements divided in the track tangential direction by normalizing with the sum signal of the two light receiving elements (hereinafter also referred to as a second detection method). The first detecting means is particularly effective in detecting incidental information in a recorded area of a CD-R medium or a CD-RW medium (disc), and the second detecting means detects light incident on two light receiving elements. In the state where there is no imbalance, the common mode noise removal ratio becomes sufficiently large, so that it is possible to accurately detect the incidental information. In this case, the operation state of the drive, for example, the type and recording state of the disk, that is, whether the disk is a recorded area or an unrecorded area, and whether the operation is a reproduction operation or a recording operation for the disk, And the like, and select an optimal detection means.

First Embodiment This first embodiment corresponds to the first and second aspects of the present invention, but also relates to the third and fourth aspects of the present invention. The invention of claim 1 is a basic invention. In the first embodiment, two types of detecting means are provided in accordance with the type of the disc and the recorded / unrecorded state in order to accurately detect the incidental information recorded in the wobble recording. It has a feature in that it is used. First, the hardware configuration will be described.

FIG. 1 is a functional block diagram showing an example of an embodiment of the main structure of the optical disk drive of the present invention. In the figure, 1 is an optical disk, 2
Is a spindle motor, 3 is an optical pickup, 4 is focus control means, 4a is a focus error signal operation circuit,
5 is a track control means, 5a is a track error signal operation circuit, 6 is a carriage servo means, 7 is a preamplifier section,
8 is a wobble signal operation circuit, 9 is a servo controller,
10 denotes a CPU, FE denotes a focus error signal, T
E indicates a track error signal, and WB indicates a wobble signal.

The structure and operation of the optical disk drive shown in FIG. 1 are as follows. Optical disk 1
Is driven to rotate by a spindle motor 2. The optical pickup 3 includes a semiconductor laser (not shown), an optical system, a focus actuator, a track actuator,
It incorporates a split light receiving element and a position sensor, and irradiates the optical disc 1 with laser light. The optical pickup 3 receives the reflected light from the optical disk 1 and supplies its output to a focus control unit 4 and a track control unit 5 via a preamplifier unit 7 at the next stage.

The focus control means 4 generates a focus error signal FE from the given light receiving signal, and the track control means 5 similarly generates a track error signal TE from the light receiving signal. The output of the preamplifier unit 7 is applied to a wobble signal operation circuit 8 to perform an operation, thereby detecting additional information recorded on the track of the optical disk 1 by wobble, that is, a wobble signal WB.

Here, the detailed configurations of the preamplifier unit 7, the focus control unit 4, the track control unit 5, and the wobble signal operation circuit 8 shown in FIG. 1 will be described with reference to FIG. Although FIG. 2 mainly shows the peripheral portion of the wobble signal operation circuit 8 of FIG. 1, in the optical disk drive of FIG. 1, the focus control means 4 and the track control means 5 are also provided with the preamplifier shown in FIG. An I / V conversion output output from the unit 7 is provided.

FIG. 2 is a functional block diagram showing an example of an embodiment of a detailed configuration of a peripheral portion of the wobble signal operation circuit 8 in the optical disk device shown in FIG. Reference numerals in the figure are the same as those in FIG. 1, 8a is a first wobble signal operation circuit, 8b is a second wobble signal operation circuit, 11a is a first light receiving element, 11b is a second light receiving element, and 12a is a second light receiving element. 1 I / V conversion circuit, and 12b is the second I / V conversion circuit.
/ V conversion circuit, 13 is a first sample hold circuit, 1
4 is a second sample-and-hold circuit, 15 is a detection system changeover switch, 16 is a band-pass filter, 17 is a binarization circuit, 18 is a medium type detecting means, 19 is a recorded / unrecorded discriminating means, and 21 is a first A high-pass filter, 22 is a first VCA (voltage control amplifier) circuit, and 23 is an AGC (auto gain control circuit) for the first RF signal.
Control) circuit, 24 is a second high-pass filter,
25 is a second VCA circuit, 26 is a second RF signal AG
C circuit, 27 is a first subtraction circuit, 31 is a second subtraction circuit, 32 is a third VCA circuit, 33 is an addition circuit, 34 is a fourth VCA circuit, and 35 is an AGC circuit.

The preamplifier unit 7 shown in FIG. 1 is composed of the first I / V conversion circuit 12a and the second I / V conversion circuit 12b shown in FIG. 2, that is, two I / V conversion circuits. Have been. As described above, in the preamplifier section 7, the first I / V conversion circuit 12a for converting the output current from the first light receiving element 11a into a current-voltage conversion, and the output current from the second light receiving element 11b. And a second I / V conversion circuit 12b for current-to-voltage conversion. The first light receiving element 11a and the second light receiving element 11b are two-divided light receiving elements built in the optical pickup 3 of FIG. As described above, in the optical disk drive shown in FIG. 1, the light receiving outputs from the light receiving elements 11a and 11b in FIG. 2 are subjected to current-voltage conversion by the two I / V conversion circuits 12a and 12b, and the I / V is converted. The converted output is input to each of the focus error signal operation circuit 4a and the track error signal operation circuit 5a, and the I / V conversion circuit 12
The outputs of a and 12b are calculated. The track error signal calculation circuit 5a is built in the track control means 5 of FIG. 1, and the focus error signal calculation circuit 4a is built in the focus control means 4.

Next, the wobble signal operation circuit 8 shown in FIG. 1 will be described. Wobble signal operation circuit 8 in FIG.
Are the two wobble signal operation circuits 8a and 8 shown in FIG.
b, each of which has two I / V conversion circuits 12a, 1
It has a function of calculating the output of 2b and outputting it. FIG.
After detecting the voltage value of the two-divided light receiving element in the preamplifier unit 7, the outputs of the two I / V conversion circuits 12a and 12b are output to the first sample and hold circuit 13 in the next stage, respectively.
The signal is input to the second sample and hold circuit 14. The sample and hold circuits 13 and 14 are circuits that sample and hold the level at the time of reproduction with a recording waveform at the time of recording in order to detect a wobble signal having the same signal quality as at the time of reproduction. The sampled and held signal is supplied to a first wobble signal operation circuit 8a and a second wobble signal operation circuit 8b.
Are output to the two arithmetic circuits.

The detection system changeover switch 15 is a switch for switching the output of the two wobble signal operation circuits 8a and 8b by a signal from the CPU 10. The calculated wobble signal is passed through the detection system changeover switch 15 and then passed through the bandpass switch. The signal passes through a binarizing circuit 17 composed of a filter 16, a comparator and the like, and is output to a wobble signal decoder (not shown). Bandpass filter 16
Is a bandpass filter that passes only the wobble signal frequency band according to the rotation speed of the spindle motor 2. The first wobble signal operation circuit 8a outputs the RF of a signal obtained by subjecting the output of each light receiving element of the two-divided light receiving element to I / V conversion.
The first high-pass filter 21 and the second high-pass filter 24 pass only high-frequency components so that the signal (reproduced signal obtained from the I / V conversion signal of the light receiving element) has a constant signal amplitude. The first RF signal AGC circuit 23 adjusts the gain of the VCA circuit 22 of the first RF signal, and the second RF signal AGC circuit 26 adjusts the gain of the second VCA circuit 25.
Each is configured to be controlled. The output of the first VCA circuit 22 and the output of the second VCA circuit 25 are subtracted by a first subtraction circuit 27, and additional information is detected from the difference between the two output signals (first detection means: first detection means: Corresponding to the detection method).

The second wobble signal operation circuit 8b subtracts, by a second subtraction circuit 31, a signal obtained by subjecting the output of each light receiving element of the two-divided light receiving element to I / V conversion. By this subtraction, the RF signal components are removed because they are in phase, but the wobble signal components are amplified at the outputs of the two-divided light receiving elements because they have opposite phases. This second subtraction circuit 31
Is controlled so that the sum signal of the I / V conversion output of the first light receiving element 11a and the I / V conversion output of the second light receiving element 11b becomes constant. This operation is performed by the addition circuit 33, the fourth VCA circuit 34,
An AGC circuit 35 and a third VCA circuit 32. That is, the addition circuit 33 obtains the sum signal of the I / V conversion output of the two-divided light receiving element, and the fourth VCA circuit 34 and the AGC circuit 35 control the output of the sum signal to be constant.

The AGC circuit 35 includes a fourth VCA circuit 34
Is measured, the gain of the fourth VCA circuit 34 is controlled by the signal amplitude, and the same gain as the gain is set in the third VCA circuit 32. By such an operation, a constant signal amplitude is obtained from the wobble signal which does not affect the variation even if the reflectance of the optical disk 1, the variation of the optical pickup 3, or the laser power in the optical pickup (not shown) varies (second). Detection means:
Corresponding to the second detection method).

It is necessary to switch between these two detection means, that is, the first wobble signal operation circuit 8a and the second wobble signal operation circuit 8b, depending on the type of disk and the recording state. In FIG. 2, the media type detecting means 1
Numeral 8 is a type determining means for determining the type of the disk,
The recording / non-recording discriminating means 19 is a recording / non-recording discriminating means for discriminating whether the optical disc 1 is unrecorded or recorded. The detection method changeover switch 15 is a selection means for selecting one of the first and second detection means, and is controlled by the signal from the CPU 10 as described above.

Next, the detection system changeover switch 15
, The switching control of the first wobble signal operation circuit 8a and the second wobble signal operation circuit 8b will be described. Generally, unrecorded CD-
The C / N of the wobble signal of the R disk is the recorded CD
Since it is better than the -R disc, there is a high possibility that the wobble signal can be reproduced. In contrast, the recorded C
Since the C / N of the DR disk and the CD-RW disk is poor, the possibility that the wobble signal cannot be reproduced increases. Therefore, in the present invention, the wobble signal operation circuit is switched according to the type of disk and the recording state (whether the disk is a recorded area or an unrecorded area) as shown in FIG.

FIG. 3 is a diagram for explaining an example of selection control of two wobble signal operation circuits in the optical disk drive of the present invention.

FIG. 3 shows a first wobble signal operation circuit 8a as first detection means and a second wobble signal operation circuit 8a according to whether the optical disk 1 of FIG. 1 is recorded or unrecorded. A case is shown in which switching is performed with the second wobble signal operation circuit 8b as the detection means. Whether the optical disc 1 is unrecorded or recorded is determined by the recorded / unrecorded determining means 19 (the first and second aspects of the invention). This determination is
Accurate determination can be made based on the presence or absence of an RF signal.
The switching control in this case is as follows when reproducing an unrecorded area of a CD-R disc or a CD-RW disc.
The second detection means is selected and detected, and when the recorded area is reproduced, the first detection means is selected and detected (the invention of claim 2). In the first embodiment, the type of the CD-R disc and the type of the CD-RW disc are not determined, but according to the media type detecting means 18, the disc is a CD-R disc or a CD-RW disc. It is also possible to determine the type (used in the invention of claim 6 described in a fifth embodiment described later). In the discrimination of this type, the media type detecting means 18 determines whether the disc is a CD-R disc or a C-R disc based on an output obtained by converting the reflectance of the disc into an electric signal.
It detects whether the disc is a D-RW disc. That is, CD
-R disc has a reflectance of 60% or more,
The reflectivity of the D-RW disc is 15% to 25%, and there is a clear difference between the two. Thus, by detecting the reflectance, it is possible to determine whether the disc is a CD-R disc or a CD-RW disc.

As described above, according to the first embodiment, in order to accurately detect the wobble-recorded incidental information, two types of discs are used in accordance with the type of the disc and the recorded / unrecorded state. A detection means is provided, and is appropriately selected and used.
Therefore, it is possible to detect the additional information optimally according to the recorded / unrecorded state of the disc. Here, the optical disk drive device shown in FIG. 1 will be supplementarily described. First, the focus error signal F generated by the focus error signal calculation circuit 4a in the focus control means 4
E is a phase correction circuit (not shown) for stabilizing the servo system and a drive amplifier (not shown)
Output a control signal to the track actuator via
It constitutes a track servo system. The servo controller 9 controls the focus control unit 4 and the track control unit 5. Also, the track error signal T
E also forms a carriage servo system via a phase correction circuit (not shown) and a drive amplifier (not shown). Next, the optical pickup 3 will be described with reference to FIGS.

FIG. 4 is an exploded perspective view showing the main structure of an optical system provided inside the optical pickup 3. As shown in FIG. In the figure, 41 is an aspherical objective lens, 42 is 1
/ 4 wavelength plate, 43 is a deflecting prism, 44 is a collimating lens, 45 is a polarizing beam splitter, 46 is a condenser lens, 47 is a semiconductor laser, 48 is a high-frequency superimposing module, and 49 is a two-division light receiving element. Note that the FE detection system is omitted.

FIGS. 5A and 5B are diagrams showing the main components of the optical system of the optical pickup 3 shown in FIG. 4, wherein FIG. 5A is a side view, and FIG. 5B is a front view of the two-division light receiving element 49. . Reference numerals in the figure are the same as those in FIG.

The light emitted from the semiconductor laser 47 enters the polarization beam splitter 45. At this time, since the direction of deflection of the laser light is the vertical direction, 100% of the laser light incident on the polarization beam splitter 45 is incident on the collimator lens 44. Since the collimating lens 44 functions to convert the diffused light into parallel light, the parallel light deflected in the vertical direction enters the deflecting prism 43.
The laser light reflected by the deflecting prism 43 passes through the quarter-wave plate 42, passes through the aspherical objective lens 41, and enters the optical disc 1. The polarization direction of the laser light becomes circularly polarized after passing through the quarter-wave plate 42, and the reflected light from the optical disc 1 becomes circularly-polarized light in the opposite direction.
2 is incident.

After passing through the quarter-wave plate 42, the polarization direction becomes the horizontal polarization direction, and the light enters the polarization beam splitter 45 via the collimator lens 44. In this state, since the polarization direction is horizontal, 100
% Enters the condenser lens 46 and is split into two light receiving elements 49.
Irradiated to The two-part light receiving element 49 is composed of two light receiving elements C and D, as shown in the front view (light receiving surface) in FIG. Note that the arrows in both directions indicate the track directions. The two-part light receiving element 49 corresponds to the two-part light receiving elements 11a and 11b shown in FIG.
The output of the divided light receiving element 11a is C, and the divided light receiving element 11b is
, The wobble signal and the RF signal are generated by the following equation. Wobble signal = CD RF signal = C + D

As described above, in the first embodiment, two detecting means (8a and 8b in FIG. 2) are selected according to the recorded / unrecorded state of the disk, and Information is detected (the invention of claim 1). Therefore, it is possible to detect the additional information optimally according to the recorded / unrecorded state of the disc. Further, at the time of reproducing the disc, the first detecting means or the second detecting means is selected and detected depending on whether the disc is an unrecorded area or a recorded area (claim 2). According to this switching control, even after the information is recorded on the disk, even if the C / N of the additional information deteriorates, it is possible to detect the optimum additional information, and further, it is possible to detect the CD-R disc or the CD-RW.
Optimal detection of incidental information is possible even in an unrecorded area of the disc.

Second Embodiment This second embodiment corresponds to the third aspect of the present invention. In the first embodiment described above, a case has been described in which two detecting means are selected according to the recorded / unrecorded state of the disc to detect the wobble-recorded incidental information. This second
In the embodiment, after the information is recorded on the disk, only when the additional information cannot be detected due to the deterioration of the C / N of the additional information, the detecting means is selected, so that the detection method changeover switch can be used. Control is simplified and C
The feature is that the load on the PU is reduced.

The hardware configuration, particularly the wobble signal operation circuit, is the same as that of FIG. In normal wobble signal detection,
The detection method switch 15 is set to be detected by the first wobble signal operation circuit 8a. With this setting, if the wobble signal is detected and detection is possible,
Wobble signal detection is performed in this state. What cannot be detected by the first wobble signal operation circuit 8a is that, in the recorded disk, an imbalance occurs in the amount of light incident on the first light receiving element 11a and the second light receiving element 11b. This is the case where common-mode noise cannot be sufficiently removed. Therefore, only at this time, the CPU 10 operates the detection mode changeover switch 15 so that the second wobble signal operation circuit 8b detects the wobble signal. As described above, the detection method changeover switch 15
, The load on the CPU 10 is reduced.

FIG. 6 is a flowchart showing the flow of main processing when the detection means is switched according to the second embodiment of the present invention. In the figure, # 1 to # 3
Indicates a step.

In step # 1, the detection system changeover switch 15 is set so as to be connected to the first wobble signal operation circuit 8a. In step # 2, it is checked whether the detection of the wobble signal is impossible. When the wobble signal can be detected, the flow of FIG. 6 ends. If the wobble signal cannot be detected, in step # 3, the detection method changeover switch 15 is set so as to be connected to the second wobble signal operation circuit 8b, and the wobble signal is detected. As described above, in the second embodiment, after information is recorded on a CD-R disc or a CD-RW disc, only when the supplementary information cannot be detected due to the C / N deterioration of the supplementary information, The detection means (detection method) is changed. Therefore, in addition to the effects of the first embodiment (especially the invention of claim 2), the CPU
Load can be reduced.

Third Embodiment The third embodiment corresponds to the fourth aspect of the present invention. In the second embodiment, a case has been described in which, after information is recorded on a disc, the detection means is changed only when the additional information cannot be detected due to deterioration of the C / N of the additional information. In the third embodiment, at the time of recording,
The second wobble signal operation circuit 8b as a second detection means
This is characterized in that the CPU 10 sets the detection mode changeover switch 15 before the start of recording so that is selected.

The hardware configuration, particularly the wobble signal operation circuit, is the same as that of FIG. When a write command is received from a user interface (not shown), it is checked before the start of writing that the detection mode changeover switch 15 is set to detect a wobble signal by the second wobble signal operation circuit 8b. After changing the settings, start recording. This operation flow is shown in FIG.
Shown in

FIG. 7 is a flowchart showing the flow of main processing when switching the detection means according to the third embodiment of the present invention. In the figure, # 11- #
Reference numeral 13 denotes a step.

At step # 11, the CPU 10 receives a write command. In step # 12, the detection mode changeover switch 15 is switched to the second wobble signal operation circuit 8b.
It is checked whether it is connected to the second wobble signal operation circuit 8b. If it is connected to the second wobble signal operation circuit 8b, the wobble signal is detected as it is, and the flow of FIG. Second
Is not connected to the wobble signal operation circuit 8b, the detection system changeover switch 15
Is set to be connected to the second wobble signal operation circuit 8b. As described above, in the third embodiment, at the time of recording, the CPU 10 causes the detection method changeover switch 15 to start selecting the second wobble signal operation circuit 8b, which is the second detection means, before starting recording. Is set. Therefore, even during recording, it is possible to optimally detect the incidental information.

Fourth Embodiment The fourth embodiment corresponds to the invention of claim 5, but also relates to the invention of claim 4. In the third embodiment, at the time of recording, the second detecting means, the second detecting means, is used.
To select the wobble signal operation circuit 8b of
The case where the detection method switch 10 is set before the start of recording has been described. By the way, in the recorded area of the CD-R disc and the CD-RW disc, if the C / N of the wobble-recorded supplementary information is bad and the supplementary information cannot be reproduced, until the start of recording, It is necessary to detect incidental information by the first detecting means. In this case, optimal detection of the incidental information cannot be performed unless the detection of the incidental information is changed to the second detecting means at the same time as the start of recording. However, the switching control of the detecting means is C
If a control method of starting recording after execution by the PU is adopted, there is a problem that the CPU processing speed is slow.
In the fourth embodiment, the first recording is performed until immediately before the start of recording.
Detecting the additional information recorded in the wobble by the detecting means of
It is characterized in that incidental information not affected by the F signal can be detected.

FIG. 8 is a functional block diagram showing another example of the detailed configuration of the peripheral portion of the wobble signal operation circuit 8 shown in FIG. Reference numerals in the figure are the same as those in FIG.
Is a detection method setting means, 52a is an AND gate circuit, 52
b is an OR gate circuit, AGCON is an AGC on signal, X
AGCOFF indicates a XAGC off signal.

The peripheral portion of the wobble signal operation circuit 8 shown in FIG. 8 is different from the peripheral portion shown in FIG. 2 in that a write gate generating means 51 and a detection method setting means 52 are added. The write gate generation means 51
However, when it receives a write command from an initiator (not shown), it has a function of starting recording information on the optical disc 1 and generating a write gate signal simultaneously with the start of the recording. The detection method setting means 52 has a function of changing the setting of the detection method switch 15 in order to switch to one of the two detection methods in accordance with a signal from the write gate generation means 51.
2a and an OR gate circuit 52b. When recording on the optical disc 1 is started, the AGCON register = 0 and the XAGCOFF register = 1 are set as shown in FIG.

FIG. 9 is a diagram showing an example of the correspondence between the selection of the detection means by the wobble signal detection method setting means and the operating state of the drive.

FIG. 9 shows a wobble signal operation circuit 8 by the wobble signal detection method setting means 52 shown in FIG.
It shows the relationship between the selection of a and 8b and the operating state of the corresponding drive. Here, the operating state of the drive means that the optical disc 1 (CD-R disc or CD-RW disc) is unused or the C / N of the incidental information recorded in the wobble-recorded area in the recorded area is poor. It means whether the supplementary information cannot be reproduced or whether it is a normal reproduction operation. First, as shown in the upper section of FIG. 9, an unused optical disc 1 (CD-R disc or CD-R disc) is used.
In the case of an RW disc, the setting is made so as to select the second detection means, that is, the wobble signal operation circuit 8b. At this time, AGCON register = 0, XAGCO
Set FF register = 0.

Next, as shown in the middle column of FIG. 9, the C / N of the recorded CD-R disc or CD-RW disc is poor, and the first detection means, ie, the wobble signal operation circuit 8a, When the additional information cannot be reproduced, the wobble signal operation circuit 8b is selected and detected by the write gate during recording by the write gate, and the wobble signal operation circuit 8a is selected and detected by the write gate during reproduction. In this case, AGCO
Set N register = 0 and XAGCOFF register = 1. With this setting, the first time until immediately before the start of recording
Since the additional information recorded by the wobble signal operation circuit 8a is detected by the wobble signal operation circuit 8a, the additional information can be detected without being affected by the RF signal even in the recorded area of the disk. Finally, FIG.
As shown in the lower column, during normal reproduction, the first wobble signal operation circuit 8a is selected and detected. At this time, the AGCON register = 1 and the XAGCOFF register = 0 or 1 are set.

FIG. 10 shows a write gate and two registers XAGCOF according to a fourth embodiment of the present invention.
9 is a timing chart showing an example of setting of detection means by F and AGCON.

FIG. 10 shows the waveforms in the state shown in the middle column of FIG. When the first half of the write gate is "0" (at the time of reproduction), the wobble signal operation circuit 8a serving as the first detection means detects additional information, and when the second half of the write gate is "1" (at the time of recording). Indicates that the additional information is detected by the wobble signal operation circuit 8b as the second detection means. As described above, in the fourth embodiment, the wobble signal is detected by the first wobble signal operation circuit 8a until immediately before the start of recording, so that the wobble signal which is not affected by the RF signal even in the recorded area. Is detected, and the second wobble signal operation circuit 8b detects at the same time as the write gate, so that an optimum wobble signal can be detected even during recording.

Fifth Embodiment The fifth embodiment corresponds to the sixth aspect of the present invention. When writing (recording) a CD-RW disc, pits are formed by modulating a laser beam.
At the time of detection of incidental information of a W disk, a sample hold that is performed at the time of writing a CD-R (to obtain the same signal quality at the time of writing as at the time of reading, the read level of the incidental information is sampled and held by a write pulse at the time of writing). ), There is a problem that the additional information is difficult to detect because the frequency is high. The fifth embodiment is characterized in that, at the time of writing on a CD-RW disc, sample-and-hold is not performed, and additional information recorded in wobble is detected.

FIG. 11 is a diagram showing an example of an embodiment of the detailed configuration of the sample and hold circuit used in the optical disk drive of the present invention. The reference numerals in the figure are the same as those in FIG. 2, 61 is an OR circuit, SW1 and SW2 are switches, and SHOFF is a sample hold-off signal.

As shown in FIG. 11, the first and second sample and hold circuits 13 and 14 are configured to be sampled and held by a switch which is turned on at H level and turned off at L level by an external signal. . That is, when an H-level signal is output from the OR circuit 61, the switch SW1 in the first sample and hold circuit 13 and the second
The switch SW2 in the sample hold circuit 14 is turned on, and the signals input to the sample hold circuits 13 and 14 are sampled. Thereafter, when an L-level signal is output from the OR circuit 61, the switches SW1 and SW2 in the first sample and hold circuit 13 and the second sample and hold circuit 14 are turned off, and when the switches are turned on, sampling is performed. The signals input to the hold circuits 13 and 14 are held.

The CPU 10 includes a medium type detecting means 18
And the detection signal from the recorded / unrecorded discriminating means 19,
When it is detected that a CD-RW disc is being recorded,
One input terminal of the OR circuit 61, that is, the sample hold off signal SHOFF is set to the H level, so that the first sample hold circuit 13 and the second sample hold circuit 14 do not operate. With such a control operation, a wobble signal can be detected without sample and hold during recording on a CD-RW disc.
Optimal wobble signal reproduction becomes possible.

FIG. 12 shows a CD-RW disc.
6 is a time chart for explaining an operation at the time of recording.

At the time of recording or reproduction of a phase-change optical disc such as a CD-RW disc, a laser beam having a power level as shown in FIG. 12 is irradiated onto the track of the disc. First, information is recorded by changing the laser power according to the recorded information to form a crystallized region and an amorphous mark on the recording film of the disk. That is, the laser power is changed in a pulse form between the write power (amorphization level) and the read power (read level) in accordance with the level of “1” of the recording information. By applying such power, the recording film is made amorphous and an amorphous mark is formed.

On the other hand, by setting the laser power to an intermediate erase power (crystallization level) corresponding to the “0” level of the recording information, the recording film is crystallized, and the crystallized area is reduced. It is formed. At the time of reproduction, light of read power (read level) is irradiated, and recorded information is read. As shown in FIG. 12, the pulse at the time of recording has a pulse shape changed between the write power and the read power. Therefore,
As described in the fifth embodiment, at the time of recording,
Obviously, if the method of detecting the wobble signal from the average value without using the sample and hold is used, the auxiliary information can be optimally detected.

[0058]

The additional information detecting circuit according to the first aspect of the present invention includes two detecting means that can set the additional information recorded by wobble according to the type of the disc and whether the information is recorded or unrecorded.
Therefore, it is possible to detect the additional information optimally according to the type of the disk and the recorded / unrecorded state.

In the optical disk drive of claim 2,
The wobble-recorded incidental information is recorded on the disc type,
Equipped with two detection means that can be set corresponding to unrecorded,
At the time of reproduction of an unrecorded area of a DR disc or CD-RW disc, the second detection means detects the information, and at the time of reproduction of an already recorded area, the first detection means detects additional information recorded by wobble recording. Therefore, even if the C / N (difference between carrier and noise levels) of the additional information deteriorates after the information is recorded on the optical disk, the additional information can be detected, and furthermore, the CD-R disc or the CD-RW can be detected. Optimal detection can be performed even in an unrecorded area of the disc.

In the optical disk drive of the third aspect,
After information is recorded on a CD-R disc or a CD-RW disc, the detecting means is changed only when the additional information cannot be detected due to the deterioration of the C / N of the additional information. Therefore, in addition to the effect of the optical disk drive device according to the second aspect, the load on the CPU can be reduced.

In the optical disk drive of claim 4,
The wobble-recorded incidental information is detected by two detection means depending on the operation state of the disc, and is detected by the second detection method during recording on a CD-R disc or CD-RW disc. Therefore, even during recording (during writing),
Optimal detection of incidental information becomes possible.

In the optical disk drive of claim 5,
5. The optical disk drive according to claim 4, wherein:
In a recorded area of the disc and the CD-RW disc, the C / N of the wobble-recorded supplementary information is poor and the supplementary information cannot be reproduced. I am trying to change to the method. Therefore, in addition to the effect of the optical disk drive device of the fourth aspect, recording can be performed even on a disk having a poor C / N.

In the optical disk drive of claim 6,
At the time of recording on a CD-RW disc, wobble-recorded incidental information is detected without performing sample hold. Therefore, at the time of recording on a CD-RW disc, the auxiliary information can be optimally detected.

[Brief description of the drawings]

FIG. 1 shows an optical disk drive of the present invention.
It is a functional block diagram showing an example of an embodiment of the main composition.

FIG. 2 is a functional block diagram showing an example of an embodiment of a detailed configuration of a peripheral portion of a wobble signal operation circuit 8 in the optical disk device shown in FIG.

FIG. 3 shows an optical disk drive of the present invention.
FIG. 9 is a diagram illustrating an example of selection control of two wobble signal operation circuits.

FIG. 4 is an exploded perspective view showing an essential structure of an optical system provided inside the optical pickup 3.

FIG. 5 is a diagram illustrating a main configuration of an optical system of the optical pickup 3 illustrated in FIG. 4;

FIG. 6 is a flowchart showing a flow of main processing at the time of switching of detection means according to the second embodiment of the present invention.

FIG. 7 is a flowchart showing a flow of main processing when a detection unit is switched according to a third embodiment of the present invention.

8 is a functional block diagram showing an example of another embodiment of a detailed configuration of a peripheral portion of the wobble signal operation circuit 8 shown in FIG.

FIG. 9 is a diagram illustrating an example of a correspondence relationship between selection of a detection unit by a wobble signal detection method setting unit and an operation state of a drive;

FIG. 10 is a block diagram showing a fourth embodiment of the present invention; a write gate and two registers XAGCOFF and AGCON;
6 is a timing chart showing an example of setting of a detection unit according to the first embodiment.

FIG. 11 is a diagram showing an example of an embodiment of a detailed configuration of a sample and hold circuit used in the optical disk drive device of the present invention.

FIG. 12 is a time chart for explaining the recording operation of a CD-RW disc.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Optical disk, 2 ... Spindle motor, 3 ... Optical pickup, 4 ... Focus control means, 4a ... Focus error signal calculation circuit, 5 ... Track control means, 5a ... Track error signal calculation circuit, 6 ...... Carriage servo means, 7 ... preamplifier section, 8 ... wobble signal operation circuit, 9 ... servo controller, 10 ...
CPU

Claims (6)

[Claims] 1. Recording / recording of information by irradiation of a light spot
An optical disk drive device for performing reproduction, wherein a drive device for detecting incidental information of an optical disk recorded wobble on a track by causing a light beam to follow a track on the optical disk, wherein a first device for detecting incidental information recorded on a wobble. And a second detecting means. The first detecting means adjusts the gain so that the RF signal AC amplitude of the two light receiving elements divided in the track tangential direction becomes constant, and then calculates the difference between the two signals. The second detecting means has a function of detecting incidental information, and has a function of normalizing a difference between two light receiving elements divided in a track tangential direction by a sum signal of the two light receiving elements and detecting the difference. A discriminating means for discriminating a disc type; a recorded / unrecorded discriminating means for discriminating whether the disc is recorded / unrecorded; and the first and second detections And a selecting means for selecting one of the means. 2. Recording of information by irradiation of a light spot.
An optical disk drive device for performing reproduction, wherein a drive device for detecting incidental information of an optical disk recorded wobble on a track by causing a light beam to follow a track on the optical disk, wherein a first device for detecting incidental information recorded on a wobble. And a second detecting means. The first detecting means adjusts the gain so that the RF signal AC amplitude of the two light receiving elements divided in the track tangential direction becomes constant, and then calculates the difference between the two signals. The second detecting means has a function of detecting incidental information, and has a function of normalizing a difference between two light receiving elements divided in a track tangential direction by a sum signal of the two light receiving elements and detecting the difference. A discriminating means for discriminating a disc type; a recorded / unrecorded discriminating means for discriminating whether the disc is recorded / unrecorded; and the first and second detections Selecting means for selecting one of the means, when reproducing an unrecorded area of a CD-R disc or a CD-RW disc, detecting by the second detecting means; An optical disk drive device, wherein at the time of reproduction of a recording area, the first detection means detects additional information recorded by wobbling. 3. Recording / recording of information by irradiation of a light spot.
An optical disk drive device for performing reproduction, wherein a drive device for detecting incidental information of an optical disk recorded wobble on a track by causing a light beam to follow a track on the optical disk, wherein a first device for detecting incidental information recorded on a wobble. And a second detecting means. The first detecting means adjusts the gain so that the RF signal AC amplitude of the two light receiving elements divided in the track tangential direction becomes constant, and then calculates the difference between the two signals. The second detecting means has a function of detecting incidental information, and has a function of normalizing a difference between two light receiving elements divided in a track tangential direction by a sum signal of the two light receiving elements and detecting the difference. A discriminating means for discriminating a disc type; a recorded / unrecorded discriminating means for discriminating whether the disc is recorded / unrecorded; and the first and second detections Selecting means for selecting one of the means, the detecting operation of the wobble-recorded incidental information is always performed by selecting and detecting the first detecting means at the time of reproduction, and performing the second operation only when the incidental information cannot be reproduced. An optical disk drive device for selecting and detecting a detecting means. 4. Recording of information by irradiation of a light spot
An optical disk drive device for performing reproduction, wherein a drive device for detecting incidental information of an optical disk recorded wobble on a track by causing a light beam to follow a track on the optical disk, wherein a first device for detecting incidental information recorded on a wobble. And a second detecting means. The first detecting means adjusts the gain so that the RF signal AC amplitude of the two light receiving elements divided in the track tangential direction becomes constant, and then calculates the difference between the two signals. The second detecting means has a function of detecting incidental information, and has a function of normalizing a difference between two light receiving elements divided in a track tangential direction by a sum signal of the two light receiving elements and detecting the difference. A discriminating means for discriminating a disc type; a recorded / unrecorded discriminating means for discriminating whether the disc is recorded / unrecorded; and the first and second detections And selecting means for selecting one of the means. When recording a CD-R disc or a CD-RW disc,
An optical disk drive device, wherein the second detection means is selected and detected. 5. The optical disk drive device according to claim 4, further comprising: means for selecting the second detection means during recording by the write gate, and selecting the first detection means during recording other than during recording. An optical disk drive device, wherein additional information is detected by the first detecting means, and the additional information recorded by wobble recording is detected by the second detecting means simultaneously with the start of recording by using a write gate. . 6. Recording of information by irradiation of a light spot.
An optical disk drive device that performs reproduction, wherein the drive device detects the incidental information of the optical disk that is wobble-recorded on the track by causing the light beam to follow the track on the optical disk, and a type determination unit that determines the type of the disk; An optical disk drive device comprising: a sample / hold stop unit for incidental information; and detecting the incidental information when recording the CD-RW disc by stopping the sample hold and detecting the incidental information recorded in the wobble.