JP4357368B2 - Disc discriminating method for optical disc device and optical disc device - Google Patents

Description

The present invention is a disk discriminating method of the optical disk device, a 及 Beauty optical disc apparatus, and more particularly, the optical disk device corresponding to the optical disk area where data is recorded with pre-pits in one revolution irrespective of the radial position exists disk discriminating method relates及 beauty optical disk apparatus.

  For example, an optical disc apparatus capable of supporting a plurality of optical disc media such as a CD and a DVD is provided. In an optical disc apparatus corresponding to such a plurality of types of optical discs, it is necessary to determine the type of the optical disc inserted in the device. An example of a general operation for discriminating the types of a plurality of optical disks will be described with reference to the drawings.

  FIG. 6 is a block diagram for explaining a configuration example of the optical disc apparatus. The optical disc apparatus includes an optical pickup 10, a servo signal generation unit 20, a servo control unit 30, and a system control unit 40. FIG. 7 is a diagram schematically showing an example of the configuration of the optical pickup 10 described above. Here, an example of an optical pickup corresponding to a CD and a DVD is shown.

  In the configuration example of FIG. 7, the optical pickup 10 includes laser diodes 11 a and 11 b that constitute the light source 11, a diffraction grating 12, a beam splitter 13, an objective lens 14, a photodetector 15 that receives reflected light from the optical disk D, and the like. And an objective lens driving device (not shown) for controlling the position of the objective lens 14 in the optical axis direction (arrow m). In this example, the two laser diodes 11a and 11b are a CD laser diode and a DVD laser diode, respectively.

  The laser light emitted from the light source 11 passes through the diffraction grating 12, is reflected by the beam splitter 13 toward the objective lens 14, and forms an optical spot on the optical disc D by the objective lens 14. The light reflected by the optical disk D passes through the objective lens 14 and the beam splitter 13, enters the photodetector 15, and is converted into an electrical signal.

  The servo signal generation unit 20 in FIG. 6 generates a servo signal based on the signal from the optical pickup 10 and sends it to the servo control unit 30. The servo control unit 30 performs phase compensation of the sent servo signal, converts it into a drive signal, and drives the objective lens driving device of the optical pickup 10.

  Further, the system control unit 40 measures the servo signal generated by the servo signal generation unit 20 by using, for example, an AD converter, determines the type of the optical disc, sets the circuit gain of the servo signal generation unit 20, and performs servo control. Controls such as loop on timing generation.

  When discriminating the type of optical disc inserted in the optical disc apparatus, the system control unit 40 first selects a circuit suitable for discriminating the optical disc for the servo signal generation unit 20 and the servo control unit 30 and sets its gain. To do. For example, when a plurality of lasers are provided to correspond to a plurality of optical disks as shown in FIG. 7, a laser diode suitable for discrimination is selected. Then, the objective lens 14 of the optical pickup 10 is driven in the focal direction to pass through the focal point, and the focus error signal, the track error signal, and the full addition signal, which are the outputs of the servo signal generation unit 20 at that time, are measured and each signal is measured. Disc is discriminated based on the amplitude of each and the ratio thereof.

  As a technique for automatically discriminating the type of optical disc as described above, for example, there is an optical disc discriminating apparatus and discriminating method described in Patent Document 1. Here, when the optical disc apparatus is in a disc discrimination mode for discriminating the type of optical disc, a drive signal is output from a focus search circuit provided for disc discrimination, and the objective lens of the optical pickup is in the focal direction (optical axis). Direction).

At this time, in the focus error signal, an S-shaped waveform appears due to reflection of the substrate surface and the recording surface as the objective lens of the optical pickup moves. Then, the optical disc apparatus generates a pulse corresponding to the S-shaped waveform. For example, in a single-sided dual-layer DVD disc having two recording layers and a hybrid disc such as a super audio CD, when the objective lens moves in one direction, two S-characters corresponding to the two recording layers are used. A waveform appears, and two pulses corresponding to the S-shaped waveform are generated. This pulse is monitored, and the type of the optical disk is discriminated from the number of pulses and the pulse interval when a plurality of pulses are generated.
JP 11-353785 A

  There are a plurality of types of optical discs having different physical structures, and some of them have different structures in the data recording area and the address information recording area. For example, there is an optical disc in which the data recording area has a groove shape, but the address information recording area has a pre-pit shape instead of the groove shape. In general, in an optical disc having a groove shape, the focus error signal when the objective lens is moved in the focal direction is shown in FIG. It becomes such an S-shaped waveform.

  However, when the prepit portion moves in the vicinity of the focal point of the objective lens in the optical disk on which the groove-shaped portion and the prepit portion are formed, a focus error signal as shown in FIG. 8B or FIG. can get. In this case, since the amplitude of the focus error signal is clearly larger than the original amplitude (the amplitude of the groove-shaped portion), when disc discrimination is performed based on the waveform of FIG. There is a possibility that an erroneous determination is made due to the influence of the unit, or that the circuit gain setting of the servo signal generation unit 20 is set smaller than the actually required gain.

  For example, it is assumed that the focus error signal is affected by the pre-pit portion and the amplitude of the S-shaped waveform becomes 2V in an optical disk having an S-shaped waveform having an amplitude of 1 V in the data recording area. In this case, the gain setting of the circuit or the like is performed with an amplitude of 2V. Generally, the servo is applied in the middle of the S-shaped signal. In this case, when the amplitude is 1 V, a range corresponding to 0.5 V on both sides is a range in which servo operation is possible.

  On the other hand, when the amplitude is 2V, the range corresponding to 1V on both sides is the range in which servo operation is possible. When discriminating servo anomalies by ½ of the amplitude on one side, when the S-shaped waveform is measured, the anomaly detection is performed at 0.5 V when the amplitude is measured as 2 V due to the influence of the pre-pits. With an amplitude of 1 V, no abnormality can be detected until servo loss occurs.

  In the technique disclosed in Patent Document 1, since the type of the optical disk is determined based on the number of pulses and the interval, an optical disk having two recording layers and an optical disk having one recording layer are determined. However, as described above, it is not possible to discriminate between optical discs having a pre-pit portion and other types of optical discs having different reflectivities.

  In addition, when dust is attached to the optical disk or the optical disk is scratched, if the objective lens is driven at that portion, the amplitude of the focus error signal becomes smaller than the original amplitude due to a decrease in reflectance. If the type of the optical disk is discriminated based on this waveform or the circuit gain is set, a problem will occur.

The present invention has been made in view of the above circumstances, and in an apparatus for discriminating the type of an optical disk from a signal waveform obtained by moving an objective lens of an optical pickup in the optical axis direction, the optical disk on which prepits are formed Or disc discriminating method of an optical disc apparatus that enables stable disc discrimination and circuit gain setting of a servo signal generation unit by suppressing amplitude abnormality due to these influences even on an optical disc on which dust is attached or scratched , it is an object to provide a 及 beauty optical disk apparatus.

According to a first technical means, information is recorded on and reproduced from a plurality of types of optical discs including an optical disc in which an area in which data is recorded in a prepit exists in one recording area regardless of the radial position of the optical disc. a disk discriminating method according to an optical disk apparatus for performing the optical pickup objective lens optical disc apparatus has driven in the focus direction, measuring the amplitude of the servo signal including a focus error signal of the S-shaped detected result of the driving Thus, in the disc discriminating method for discriminating the type of the optical disc, the operation of driving the objective lens in the focal direction is performed a plurality of times by reciprocating driving, and the amplitude of each S-shaped focus error signal detected as a result of the driving is measured. The intermediate value of the amplitude measurement results for each driving direction detected by driving in the focal direction multiple times is adopted. Determines the type of the optical disk from the amplitude measurements of the intermediate value, among the amplitude measurement result of the focus error signal, if compared with the intermediate value specified value or more different results are present, the current optical disk is independent of the radial position First, it is characterized in that it is discriminated as an optical disc in which an area in which data is recorded with prepits exists in one recording area .

The second technical means is characterized in that, in the first technical means, the circuit gain setting of the servo signal generation unit of the optical disc apparatus is performed from the amplitude measurement result of the intermediate value .

According to a third technical means, information is recorded on and reproduced from a plurality of types of optical discs including an optical disc in which an area in which data is recorded in a prepit exists in one recording area regardless of the radial position of the optical disc. A disc discriminating method by an optical disc apparatus, wherein an objective lens of an optical pickup provided in the optical disc apparatus is driven in a focal direction, and an amplitude of a servo signal including an S-shaped focus error signal detected as a result of driving is measured. Thus, in the disc discrimination method for discriminating the type of optical disc, the operation of driving the objective lens in the focal direction is performed a plurality of times by reciprocating drive, and the maximum value and the minimum value are obtained for each S-shaped focus error signal detected as a result of driving. Measure the value, adopt the median value of the measured maximum value and the median value of the minimum value, Seeking the amplitude of the signal, calculated to determine the type of the optical disk from the amplitude, among the measurement results of the maximum value and the minimum value of the focus error signal, if the specified value or more as compared with the intermediate value different results exists Is characterized in that it discriminates that the current disc is an optical disc in which an area in which data is recorded with pre-pits exists in one recording area regardless of the radial position .

According to a fourth technical means, information is recorded on and reproduced from a plurality of types of optical discs including an optical disc in which an area in which data is recorded in a pre-pit exists in one recording area regardless of the radial position of the optical disc. An optical disc apparatus that performs an optical pickup including an objective lens that forms an optical spot on a disc and a lens driving unit that drives the objective lens in a focal direction thereof, and generates a servo signal based on a signal from the optical pickup Servo signal generation unit, servo control unit that performs phase compensation of the servo signal generated by the servo signal generation unit, converts it into a drive signal and drives the lens driving means, and servo signal generated by the servo signal generation unit And a control unit for determining the type of light, and the control unit moves the objective lens in the focal direction by lens driving means. The driving operation is performed a plurality of times by reciprocating driving, the amplitude of each S-shaped focus error signal detected as a result of driving is measured, and the amplitude is measured for each driving direction detected by the driving in the focal direction a plurality of times. The intermediate value of the results is adopted, the type of the optical disc is determined from the amplitude measurement result of the intermediate value, and the control unit is a result that differs from the amplitude measurement result of the focus error signal by a specified value or more compared to the intermediate value. Is present, it is determined that the current optical disc is an optical disc in which an area in which data is recorded by prepits exists in one recording area regardless of the radial position.

The fifth technical means is characterized in that, in the fourth technical means, the control unit sets the circuit gain of the servo signal generation unit from the amplitude measurement result of the intermediate value.

According to a sixth technical means, information is recorded on and reproduced from a plurality of types of optical discs including an optical disc in which an area in which data is recorded in a pre-pit exists in one recording area regardless of the radial position of the optical disc. An optical disk device that performs an optical pickup including an objective lens that forms an optical spot on an optical disk and a lens driving unit that drives the objective lens in a focal direction thereof, and generates a servo signal based on a signal from the optical pickup Servo signal generation unit, servo control unit that performs phase compensation of the servo signal generated by the servo signal generation unit, converts it into a drive signal and drives the lens driving means, and servo signal generated by the servo signal generation unit And a control unit for discriminating the type of the optical disc, and the control unit uses the lens driving means to detect the objective lens. The driving operation in the focal direction is performed a plurality of times by reciprocating driving, the maximum value and the minimum value are measured for each S-shaped focus error signal detected as a result of driving, and the intermediate value and the minimum value of the measured maximum values are measured. The intermediate value is adopted, the amplitude of the focus error signal is obtained from each intermediate value, the type of the optical disc is determined from the obtained amplitude, and among the measurement results of each maximum value and each minimum value of the focus error signal, the intermediate value and If there is a result that is different from the specified value by comparison, it is determined that the current optical disc is an optical disc in which the data recorded by the pre-pits exists in the recording area of one round regardless of the radial position. It is a characteristic.

According to the present invention, in an optical disc apparatus that operates a plurality of types of optical discs, a recording area is formed by prepits by measuring the amplitude of the S-shaped signal of the focus error signal by driving the objective lens a plurality of times in the focal direction. Even in the case of an optical disc, it is possible to make highly reliable disc discrimination and set the circuit gain of the servo signal generator without being affected by the amplitude abnormality caused by the pre-pit portion.
Furthermore, in the measurement of the amplitude of the S-shaped waveform, the peak value and the bottom value are measured independently, and the magnitude relation of the measured values is discriminated, so that the disc discrimination and servo signal generation with higher reliability can be performed. It is possible to set the circuit gain of the unit.

Optical disc apparatus of the present invention can be carried out in the configuration of FIG. 6 above, it is possible to execute the optical disc discriminating how the present invention in apparatus of FIG.
As described above, the optical disc apparatus shown in FIG. 6 includes the optical pickup 10, the servo signal generation unit 20, the servo control unit 30, and the system control unit 40. The optical pickup 10 includes a laser diode as a light source, an optical system including an objective lens, a photodetector that receives reflected light from the optical disk, an objective lens driving device that controls the position of the objective lens in the optical axis direction, and the like. ing. Then, the servo signal generator 20 generates a servo signal based on the signal from the optical pickup 10, the servo controller 30 compensates the phase of the servo signal, converts it into a drive signal, and drives the objective lens driving device of the optical pickup 10. To do.

  The system control unit 40 measures the servo signal generated by the servo signal generation unit 20 using, for example, an AD converter, determines the type of the optical disc, sets the circuit gain of the servo signal generation unit 20, and the servo loop. Controls such as on-timing generation.

  When discriminating the disc type, first, the system control unit 40 selects a circuit suitable for discriminating the optical disc for the servo signal generation unit 20 and the servo control unit 30, and sets the gain. For example, when there are a plurality of lasers, a laser suitable for discrimination is selected. Then, the objective lens is driven in the focal direction to pass the in-focus point, and the type of the optical disk is determined based on the amplitude of the focus error signal, which is the output of the servo signal generation unit 20 at that time, or the maximum value and the minimum value. .

A specific processing example for discriminating the optical disc will be described below.
For example, DVD media that are recordable optical discs include DVD-RAM, DVD-R, DVD-RW, and the like. Among these, since the pre-pit portion is not formed on the DVD-R or DVD-RW disc, the amplitude of the S-shaped waveform of the focus error signal obtained by driving the objective lens varies with the reflectance of the optical disc. It falls within the range of variation due to etc.

  However, the DVD-RAM has a pre-pit portion in which disc ID information is recorded. When the objective lens is driven with respect to such a DVD-RAM disc, if the pre-pit portion is present in the S-shaped waveform generation portion of the obtained focus error signal, the amplitude of the S-shaped waveform is It becomes larger than the amplitude of other data recording area portions. That is, as described above, the focus error signal obtained in a portion other than the prepit has an S-shaped waveform as shown in FIG. 8A, and the focus error signal obtained in the prepit portion is shown in FIG. Alternatively, an S-shaped waveform as shown in FIG.

  In the case of a two-layer disc having two recording layers on one side as described above, the S-shaped waveform is observed twice by one driving of the objective lens (one direction driving in the focal direction). The Further, since the characteristics of each layer of the two-layer disc are in a range defined by a predetermined standard, the amplitude ratio of the amplitudes of the two S-shaped waveforms falls within a certain range.

  Based on the characteristics of each optical disk as described above, the type of the optical disk can be determined from the amplitude of the S-shaped waveform of the focus error signal obtained when the objective lens is driven. For example, if an S-shaped waveform is observed twice by a single drive of the objective lens, it can be determined that the disc is a double-layer disc. Further, since the reflectivity of DVD-R is about 3 times that of DVD-RW, a prescribed value that can be discriminated is set in advance, and an S-shaped waveform of a focus error signal obtained by driving the objective lens once. Can be determined to be a DVD-R if the amplitude is equal to or greater than the specified value, and DVD-RW can be determined to be less than the specified value.

  Here, the reflectivity of the DVD-RAM is almost the same as that of the DVD-RW, and the S-shaped waveform measured in the area other than the pre-pit part of the DVD-RAM, that is, the data storage area of the groove part is almost the same as that of the DVD-RW. Amplitude. As described above, when the S-shaped waveform is measured at the pre-pit portion of the DVD-RW, the amplitude increases. Therefore, if the amplitude is greater than the specified value, it is necessary to determine whether it is due to the pre-pit or the reflectance. Become.

  In general, since the address information recorded in the pre-pit portion is smaller than the data amount recorded in the data recording area of the groove portion, the objective lens is driven in the focal direction, and the S of the focus error signal is obtained multiple times. The presence or absence of the influence of the pre-pit portion can be determined by generating a character waveform and performing the measurement.

  That is, when a plurality of S-shaped waveforms are measured by moving the objective lens in one direction a plurality of times, a plurality of S-shaped waveforms are obtained unless the objective lens driving cycle and the optical disk rotation cycle are the same. Different locations on the optical disc will be measured. At this time, as described above, since the area of the prepit portion is smaller than other data storage areas, the possibility that measurement is performed in the prepit portion in all of a plurality of times is extremely small.

When the objective lens is driven a plurality of times, the variation in the amplitude of the S-shaped waveform a plurality of times is within the variation range of the amplitude due to the reflectance variation of the optical disk, etc., if there is no influence of the pre-pits. Make predictions. When there is an influence of the pre-pit portion, an S-shaped waveform having a large amplitude is generated beyond this prediction range. Therefore, when the amplitude measurement result is within a certain range of dispersion, it means that the optical disk without the prepit portion does not pass the prepit at the time of measurement.
In this way, the presence or absence of the influence of the prepit portion can be determined from the amplitude of the S-shaped waveform a plurality of times.

  Similarly, when dust or the like adheres to the optical disk or the optical disk is scratched, the reflectance decreases, and in this case, the amplitude of the S-shaped waveform decreases. At this time, it is unlikely that dust or scratches are present on the entire surface of the optical disk. Therefore, if the drive cycle of the objective lens and the rotation period of the optical disk are shifted, the same dust and scratches are applied to the generation position of the S-shaped waveform. I can't think of that. Therefore, when the objective lens is driven a plurality of times and there is an S-shaped waveform with a small amplitude exceeding the prediction range, it can be determined that the reflectance is reduced due to the influence of dust or scratches.

FIG. 1 is a diagram for explaining a processing example of disc discrimination or signal gain setting according to the present invention, and shows an example of an S-shaped waveform of a focus error signal.
For example, if the measurement of the S-shaped signal of the focus error signal is performed three times, it is necessary to drive the objective lens in one reciprocating semifocal direction. Assuming that the focus error signal obtained at this time has a waveform as shown in FIG. 1, since the number of measurements is 3, the intermediate value Xb, which is the second largest value, is adopted, and the type of the optical disc is determined as a measurement result.

  The reason why the intermediate value of the measured values is adopted is to eliminate the influence of the above-mentioned pre-pits, dust, scratches and the like. The probability of measuring prepits and the probability of measuring dust attached to an optical disc or a scratched portion of an optical disc is very low. Here, the objective lens is driven a plurality of times to perform a reciprocating operation, and an S-shaped waveform of the focus error signal is measured for each driving in each direction, and an intermediate value thereof is adopted, so that these prepits and dust or S-shaped waveforms affected by scratches can be eliminated. In the driving of the objective lens a plurality of times, the probability that the pre-pit, dust or scratch is applied a plurality of times is extremely small, and a highly reliable measurement can be performed by the method of taking the intermediate value.

If there is a measurement result that exceeds the specified value compared to the intermediate value of the measurement results among the multiple measurement results of the focus error signal, it is determined that the amplitude has increased due to the pre-pit part, and an attempt is made to operate. It can be determined that there is an area recorded with pre-pits on the optical disc.
Further, since the existence probability of the pre-pits in the recording area of the optical disk is known, the number of measurements may be set in consideration of the setting of the rotation period of the optical disk as the objective lens drive period.

  FIG. 2 is a diagram for explaining another processing example of disc discrimination or signal gain setting according to the present invention, and shows an example of an S-shaped waveform of a focus error signal. Here, the amplitude value of the S-shaped signal of the focus error signal is not measured as described in FIG. 1, but the influence of the pre-pit portion is further measured by measuring the peak value and the bottom value of each S-shaped waveform. Can be suppressed. For example, when the focus error signal is as shown in FIG. 2, in the case of measuring only the amplitude, Yc is an intermediate value, and the amplitude value having the influence of the pre-pit portion is the measurement result. However, by measuring the peak value and the bottom value, respectively, MAb is adopted as the peak value and MIa is adopted as the bottom value. As a result, the amplitude value becomes MAb-MIa, and the influence of the prepit portion can be eliminated.

  In the case of the above example, the presence or absence of the prepit portion can be determined by comparing the measured values. In the case of the example in FIG. 1, if there is a difference more than the variation considering the reflectance variation of the optical disc by comparing Xb and Xa, it is determined that there is a pre-pit. In the case of the example in FIG. 2, Ya and MAb-MIa are compared, and if there is a difference more than the variation considering the reflectance variation of the optical disc, it is determined that there is a prepit. For example, if there is a measurement result that differs by more than a specified value compared to the intermediate value of the measurement results among multiple measurement results of the focus error signal, it is determined that the amplitude has increased due to the pre-pit portion, and an attempt is made to operate. It can be determined that there is an area recorded with pre-pits on the optical disc.

  In each example, the amplitude values are Xb and MAb-MIa. Therefore, determination is made based on these values, and the circuit gain of the servo signal generation unit may be set based on the values. As a result, the optimum circuit gain can be set by eliminating the influence of the pre-pits.

In addition to this, it is basically composed of a block that generates a servo signal based on a signal from an optical pickup in an optical disk device and a control part that takes in and determines the servo signal. Thus, by determining the peak value, bottom value, and amplitude value of the S-shaped waveform, disc discrimination and signal gain setting may be performed by the above-described processing.
In addition, a peak hold circuit and a bottom hold circuit are placed in a block that generates a servo signal, and the output is taken in by an AD converter to obtain a peak value, a bottom value, and an amplitude value. Gain setting may be performed.

FIG. 3 is a flowchart for explaining a processing example of the disk discrimination method of the present invention. The optical disk apparatus used here is capable of recording information on and reproducing information from a plurality of types of optical disks including an optical disk in which an area where data is recorded by prepits is present in one recording area regardless of the radial position of the optical disk. Is possible.
First, the operation of driving the objective lens in the focal direction is performed a plurality of times by reciprocating driving (step S1), and the amplitude of each S-shaped focus error signal detected as a result is measured (step S2). Then, an intermediate value of the amplitude measurement results for each driving direction detected by driving in the focal direction a plurality of times is adopted (step S3), and the type of the optical disc is discriminated from the amplitude measurement result of the intermediate value ( Step S4). At this time, if the result of amplitude measurement of the focus error signal is different from the intermediate value by more than the specified value, the current disc is pre-pit in the recording area of one round regardless of the radial position. The disc is discriminated to be an optical disc in which an area where data is recorded exists.

FIG. 4 is a flowchart for explaining another processing example of the disk discriminating method of the present invention. Similarly, the optical disk apparatus used here also records information on a plurality of types of optical disks, including an optical disk in which an area in which data is recorded in a prepit exists in one recording area regardless of the radial position of the optical disk. Playback is possible.
First, the operation of driving the objective lens in the focal direction is performed a plurality of times by reciprocating driving (step S11), and the maximum value and the minimum value are measured for each S-shaped focus error signal detected as a result of driving (step S12). ). Then, the measured intermediate value of the maximum value and the intermediate value of the minimum value are adopted (step S13), the amplitude of the focus error signal is obtained from each intermediate value (step S14), and the type of the optical disc is discriminated from the obtained amplitude (step S14). Step S15). At this time, if there is a result that differs from the measured value of the maximum value and minimum value of the focus error signal by more than a specified value compared to the intermediate value, the current optical disk is rotated one round regardless of the radial position. It is determined that the optical disk has an area in which data is recorded by prepits in the recording area.

FIG. 5 is a flowchart for explaining another processing example of the optical disc discrimination method of the present invention. Similarly, the optical disc apparatus used here records information on a plurality of types of optical discs and reproduces recorded information, including an optical disc in which an area in which data is recorded with pre-pits exists in one recording area regardless of the radial position of the optical disc. Is possible.
First, the operation of driving the objective lens in the focal direction is performed a plurality of times by reciprocating driving (step S21), and the amplitude of each S-shaped focus error signal detected as a result of driving is measured (step S22). Then, an intermediate value of the amplitude measurement results for each driving direction detected by the plurality of times of driving in the focal direction is adopted (step S23), and the servo signal generation unit of the optical disc apparatus uses the intermediate value amplitude measurement result. Circuit gain setting is performed (step S24).

It is a figure for demonstrating the example of a process of disc discrimination | determination or signal gain setting by this invention. It is a figure for demonstrating the other example of a process of disc discrimination | determination or signal gain setting by this invention. It is a flowchart for demonstrating the process example of the disc identification method of this invention. It is a flowchart for demonstrating the other process example of the disc identification method of this invention. It is a flowchart for demonstrating the other example of a process of discriminating the disk of this invention. FIG. 25 is a block diagram for explaining a configuration example of an optical disc device. It is a figure which shows an example of a structure of an optical pick-up roughly. It is a figure which shows the example of a waveform of a focus error signal when an objective lens moves to a focus direction.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Optical pick-up, 11 ... Light source, 11a, 11b ... Laser diode, 12 ... Diffraction grating, 13 ... Beam splitter, 14 ... Objective lens, 15 ... Photo detector, 20 ... Servo signal generation part, 30 ... Servo control part, 40: System control unit.

Claims (6)

Disc discriminating method by an optical disc apparatus for recording information on and reproducing a plurality of types of optical discs including an optical disc in which an area in which data is recorded by prepits exists in one recording area regardless of the radial position of the optical disc By driving the objective lens of the optical pickup provided in the optical disc apparatus in the focal direction and measuring the amplitude of the servo signal including the S-shaped focus error signal detected as a result of the driving, the type of the optical disc In the disc discrimination method for discriminating
The operation of driving the objective lens in the focal direction is performed a plurality of times by reciprocating driving, the amplitude of each S-shaped focus error signal detected as a result of the driving is measured, and detected by driving in the focal direction a plurality of times. Adopting an intermediate value of the amplitude measurement results for each driving direction, discriminating the type of optical disc from the amplitude measurement results of the intermediate values,
If there is a result that differs from the intermediate value by more than a specified value among the amplitude measurement results of the focus error signal, the current optical disc is pre-pit data in one recording area regardless of the radial position. Disc discriminating method for an optical disc apparatus, discriminating that the disc is an optical disc in which an area in which is recorded exists.   2. The disk discriminating method for an optical disc apparatus according to claim 1, wherein circuit gain setting of a servo signal generation unit of the optical disc apparatus is performed from the amplitude measurement result of the intermediate value. Disc discriminating method by an optical disc apparatus for recording information on and reproducing a plurality of types of optical discs including an optical disc in which an area in which data is recorded by prepits exists in one recording area regardless of the radial position of the optical disc By driving the objective lens of the optical pickup provided in the optical disc apparatus in the focal direction and measuring the amplitude of the servo signal including the S-shaped focus error signal detected as a result of the driving, the type of the optical disc In the disc discriminating method, the operation of driving the objective lens in the focal direction is performed a plurality of times by reciprocating driving, and the maximum value and the minimum value are measured for each S-shaped focus error signal detected as a result of the driving. The intermediate value of the measured maximum value and the intermediate value of the minimum value are adopted, and the focus error signal is calculated from each intermediate value. Seeking the amplitude, to determine the type of the optical disc from the calculated amplitude, among the measurement results of the maximum value and the minimum value of the focus error signal, the intermediate value compared to a specified value or more different results and the presence When discriminating, a disc discriminating method for an optical disc apparatus, wherein the disc is discriminated as an optical disc in which an area in which data is recorded by prepits is present in a recording area of one circumference irrespective of a radial position . An optical disc apparatus that performs information recording and reproduction of recorded information on a plurality of types of optical discs including an optical disc in which an area in which data is recorded by prepits exists in a recording area of one round regardless of a radial position of the optical disc, The optical disc apparatus includes an optical pickup including an objective lens that forms an optical spot on the disc and a lens driving unit that drives the objective lens in a focal direction thereof, and servo signal generation that generates a servo signal based on a signal from the optical pickup. A servo control unit that performs phase compensation of the servo signal generated by the servo signal generation unit, converts the phase into a drive signal and drives the lens driving unit, and a servo signal generated by the servo signal generation unit. A control unit that performs measurement and discriminates the type of light, and the control unit includes the objective lens by the lens driving unit. Each driving direction detected by multiple times of driving in the focal direction is performed by performing the driving operation in the focal direction a plurality of times by reciprocating driving, measuring the amplitude of each S-shaped focus error signal detected as a result of the driving. Adopting an intermediate value of the amplitude measurement results for each of the above, discriminating the type of optical disc from the amplitude measurement results of the intermediate values,
When there is a result that differs from the intermediate value by a specified value or more among the amplitude measurement results of the focus error signal, the control unit determines that the current optical disc is recorded in one recording area regardless of the radial position. An optical disc apparatus characterized by discriminating that an optical disc has an area in which data is recorded with pre-pits. 5. The optical disc apparatus according to claim 4 , wherein the control unit sets a circuit gain of the servo signal generation unit from the amplitude measurement result of the intermediate value. An optical disc apparatus that performs information recording and reproduction of recorded information on a plurality of types of optical discs including an optical disc in which an area in which data is recorded by prepits exists in a recording area of one round regardless of a radial position of the optical disc, The optical disc apparatus includes an optical pickup including an objective lens that forms an optical spot on an optical disc and a lens driving unit that drives the objective lens in a focal direction thereof, and servo signal generation that generates a servo signal based on a signal from the optical pickup. A servo control unit that performs phase compensation of the servo signal generated by the servo signal generation unit, converts the phase into a drive signal and drives the lens driving unit, and a servo signal generated by the servo signal generation unit. A control unit that performs measurement and discriminates the type of the optical disc, and the control unit uses the lens driving unit to The operation of driving the object lens in the focal direction is performed a plurality of times by reciprocating driving, the maximum value and the minimum value are measured for each S-shaped focus error signal detected as a result of the driving, and the intermediate value of the measured maximum value An intermediate value between the value and the minimum value is employed, the amplitude of the focus error signal is obtained from each intermediate value, the type of the optical disc is determined from the obtained amplitude, and each maximum value and each minimum value of the focus error signal is measured. If there is a result that differs from the intermediate value by more than a specified value among the results, there is an area in which data is recorded by prepits in the recording area of one circumference of the current optical disc regardless of the radial position. An optical disc apparatus that discriminates an optical disc.

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