JP2002304752A - Optical disk device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical disk device in which the position of the objective lens is optimized so that the objective lens of an optical pickup is not deviated from the center of the optical axis and the quality of reproducing and recording is unaffected. SOLUTION: The device is so composed that the position of the objective lens 4 is arbitrarily deviated with respect to an output light of a light source 3, a recording is performed by using the trial write-in region of a recording type optical disk 1 while the position of the objective lens 4 is deviated, an optimum position of the objective lens is detected on the basis of a parameter which is given by reproducing the recorded region or a parameter which is given by a reflected light during the recording, the position of the objective lens 4 is corrected, and the objective lens is located at the optimum objective lens position. Thus, an adverse influence on the reproducing and recording is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to correction of an objective lens position of an optical pickup in an optical disk device, and more particularly to detection of an optimum objective lens position by performing test writing in a test writing area of a recordable disk. ,
The present invention relates to an optical disk device that corrects the position of an objective lens.

[0002]

2. Description of the Related Art A test signal is recorded by irradiating a laser beam from an optical pickup onto a test writing area provided on a recordable optical disc, and the test signal is reproduced to detect an optimum recording condition from the recorded state. Optical disk devices that perform this operation are known.

For example, Japanese Patent Application Laid-Open No. 2000-285485 discloses that when an offset voltage is added stepwise to a tracking error signal in a test writing area of an optical disk in this type of optical disk device, and the recording state becomes optimal ( A configuration is disclosed in which a β (asymmetry) value representing the symmetry of an RF signal obtained when a recorded portion is reproduced is measured, and a tracking error signal offset voltage of when an optimal β value is obtained is set as an optimal offset voltage. Have been.

According to this configuration, the position of the light spot with respect to the track of the optical disk can be corrected by setting the tracking control signal to the optimum offset voltage and offsetting it during recording.

[0005]

However, the configuration disclosed in the above publication has a problem that the optical axis of the objective lens cannot be corrected.

That is, when the objective lens is deviated from the center of the optical axis of the light source, the spot shape of the beam output from the optical pickup is usually distorted and the output light quantity is reduced. It is known to give. However, according to the method described in the above publication, the position of the light spot with respect to the track can be corrected by adding an offset voltage to the tracking error signal, but the position of the objective lens with respect to the optical axis cannot be corrected. Therefore, if the objective lens position is deviated from the center of the optical axis due to, for example, a change in the assembly accuracy of the optical pickup or a change in the installation attitude of the optical disk device, the reproduction is performed due to the distortion of the beam spot shape or a decrease in the output light amount. -A defect that adversely affects recording quality occurs.

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problem.
It is an object of the present invention to provide an optical disk device that optimizes the position of an objective lens so as not to adversely affect recording quality.

[0008]

In order to solve the above-mentioned problems, an optical disk apparatus according to the present invention has a configuration in which the position of an objective lens can be arbitrarily deviated with respect to the output light of a light source. Using the area, recording is performed while the objective lens position is deviated, and the optimal objective lens position is detected from the parameters obtained by reproducing the recording area or the parameters obtained from the reflected light during recording. Make corrections.

According to this configuration, when the position of the objective lens is deviated from the center of the optical axis, it is possible to correct the optical axis of the objective lens.

[0010]

According to the first aspect of the present invention, test writing is performed in a test writing area provided on a recordable optical disk by an optical pickup having an objective lens, and the result of the test writing is obtained. An optical disc device for detecting an optimum recording condition based on the tracking actuator, wherein the tracking actuator drives an objective lens position of the optical pickup in a direction crossing a track with respect to output light from a light source of the optical pickup; An offset voltage circuit for adding an offset voltage to a drive voltage applied to the objective lens position while changing the output voltage of the offset voltage circuit in a stepwise manner with the recording power constant in the test writing area. After recording with the object biased, the area recorded with the object lens position deviated is re-recorded. And, as the optimum offset voltage an output voltage of the offset voltage circuitry recording state becomes optimal is obtained by said adding to said tracking actuator driving voltage.

According to this configuration, in the test writing area of the recordable optical disc, the offset voltage is added to the tracking actuator drive voltage while changing the offset voltage stepwise by the offset voltage circuit in a state where the recording power is constant. Recording can be performed with a stepwise deviation in the direction across the track with respect to the output light of the light source. Thereafter, the recorded test write area is reproduced, and an offset voltage that optimizes the recording state is set as an optimal offset voltage, and is added to the tracking actuator drive voltage during operation of the optical disc apparatus, thereby obtaining an optimal recording state of the objective lens. Can be reproduced.

Next, according to a second aspect of the present invention, in the optical disk device according to the first aspect, the output voltage of the offset voltage circuit is changed stepwise in the test writing area to thereby adjust the position of the objective lens. After recording with a bias, the recording state of the recorded portion is determined by parameters of the symmetry, level, jitter or error rate of the reproduced RF signal,
An output voltage value of an offset voltage circuit corresponding to a recording state in which one or more of the parameters satisfies an optimum value or a predetermined value is set as an optimum offset voltage. After recording in the trial writing area, RF obtained when reproducing the recorded area
The offset voltage at which the signal symmetry, level, jitter, and error rate counted during decoding are optimal in the acquired data or are values that satisfy a certain predetermined value, Can be obtained favorably.

Next, according to a third aspect of the present invention, in the optical disk device according to the first aspect, the output voltage of the offset voltage circuit is changed stepwise in the test writing area, and the position of the objective lens is changed. When biasing and recording
By adding the offset voltage to the tracking actuator drive voltage in advance by the offset voltage circuit and shifting the position of the objective lens toward the inner circumference or outer circumference of the disk with respect to the optical axis center of the light source, The position of the objective lens is deviated in an arbitrary range including the center of the optical axis. According to this configuration, the objective lens is necessarily deflected stepwise in a range including the center of the optical axis. As a result, reliability is improved.

Next, according to a fourth aspect of the present invention, in the optical disk device according to the first aspect, the output voltage of the offset voltage circuit is changed stepwise in the test writing area, and the position of the objective lens is changed. When biasing and recording
A reflected light amount detection circuit for detecting the amount of reflected light from the optical disk during recording is provided, and the output of the offset voltage circuit is such that the level of the amount of reflected light detected by the reflected light amount detection circuit satisfies an optimum value or a predetermined value. With this configuration, the voltage value is set to an optimum offset voltage. With this configuration, when recording in the test writing area, the reflected light amount detection circuit detects the reflected light amount from the disk, and the level of the detected reflected light amount Is optimal or an offset voltage when the predetermined value is satisfied can be favorably obtained as an optimal offset voltage.

Next, according to a fifth aspect of the present invention, in the optical disk device according to the first aspect, the output voltage of the offset voltage circuit is changed stepwise in the test writing area to thereby adjust the position of the objective lens. An optical disk device for recording the data while biasing the offset and detecting the optimum offset voltage, comprising a storage circuit for holding the optimum offset voltage, and storing the optimum offset voltage in the storage circuit when the optimum offset voltage is detected. In the following, when the optical disk device is started thereafter, the optimum offset voltage stored in the storage circuit is called and added to the tracking actuator drive voltage. For example, since the optimum offset voltage is stored in the storage circuit, it is only necessary to call the optimum offset voltage at the time of recording. It is not necessary to perform the operation every time.

According to a sixth aspect of the present invention, in the optical disk device according to the fifth aspect, the optimum offset voltage held in the storage circuit is set when a predetermined period has elapsed or This feature is updated when the operating environment temperature of the optical pickup and the attitude of the optical disc device change. According to this configuration, it is optimally optimized only when the optimal offset voltage may change. The offset voltage can be updated.

Next, according to a seventh aspect of the present invention, in the optical disk device according to the fifth aspect, the storage circuit holds an optimum offset voltage corresponding to a predetermined attitude of the optical disk device in advance. Every time, when determining the attitude of the optical disk device, re-acquiring the optimal offset voltage, comparing the optimal offset voltage held in the storage circuit with the optimal offset voltage acquired again, and acquiring the optimal offset voltage again. It is characterized in that the attitude corresponding to the optimal offset voltage that is coincident with or closest to the optimal offset voltage is determined as the current attitude of the optical disc device. The current attitude of the optical disk device can be determined satisfactorily.

Next, according to the invention described in claim 8 of the present invention, test writing is performed in a test writing area provided on a recordable optical disk by an optical pickup having an objective lens, and based on the result of the test writing. An optical disc device that detects an optimal recording condition by using a feed motor that drives a feed mechanism that sends the optical pickup in a radial direction of the disc, a shutoff circuit that shuts off a drive voltage applied to the feed motor, and the tracking actuator. A voltage detection circuit that detects a drive voltage; and an offset voltage circuit that adds an offset voltage to the tracking actuator drive voltage. A state in which the object follows the deviation of the objective lens Then, recording is performed in the test writing area with a constant recording power. During recording, the tracking actuator drive voltage is detected by the voltage detection circuit, and after recording, the area where the objective lens position is deviated and recorded is recorded. The output voltage of the offset voltage circuit is set such that the tracking actuator drive voltage at the time when the reproduction and recording conditions are optimal is set as the optimal tracking actuator drive voltage so that the tracking actuator drive voltage matches the optimal tracking actuator drive voltage. It is characterized by the following.

With this configuration, when the drive voltage applied to the feed motor is cut off by the cutoff circuit, the tracking servo follows only by the deviation of the objective lens.
Recording can be performed with only the objective lens position deviated in the direction crossing the track with respect to the output light of the light source. Thereafter, the recorded test write area is reproduced, and an offset voltage that optimizes the recording state is set as an optimal offset voltage, and is added to the tracking actuator drive voltage during operation of the optical disc apparatus, thereby obtaining an optimal recording state of the objective lens. Position can be obtained.

According to a ninth aspect of the present invention, in the optical disk device according to the eighth aspect, the drive voltage applied to the feed motor is cut off by the cutoff circuit in the test writing area, thereby achieving the objective. After recording with the lens deviated, the recording state of the recording portion is determined based on the symmetry, level, jitter or error rate of the reproduced RF signal, and one or more of the parameters satisfy an optimum value or a predetermined value. It is characterized in that the detected voltage value of the voltage detection circuit corresponding to the recording state is an optimal tracking actuator drive voltage, by this configuration,
After recording in the test writing area, the symmetry, level, jitter and error rate counted during decoding of the RF signal obtained when the recorded area is reproduced are optimal in the acquired data, or a certain predetermined value. The offset voltage at which the value satisfies is satisfied can be satisfactorily obtained as the optimum offset voltage.

Next, according to a tenth aspect of the present invention, in the optical disk apparatus according to the eighth aspect, the drive voltage applied to the feed motor is cut off by the cutoff circuit in the test writing area, so that the objective voltage is reduced. When recording with the lens deviated, the offset voltage was previously added to the tracking actuator drive voltage by an offset voltage circuit, and the position of the objective lens was shifted toward the disk inner circumference with respect to the optical axis center of the light source. By setting the state, the position of the objective lens is deviated in an arbitrary range including the center of the optical axis. According to this configuration, the objective lens is always moved in a range including the center of the optical axis. Since the bias can be made stepwise, the reliability is improved.

Next, according to an eleventh aspect of the present invention, in the optical disk apparatus according to the eighth aspect, the drive voltage applied to the feed motor is cut off by the cutoff circuit in the test writing area, thereby achieving the objective. When recording with the lens deviated, a reflection light amount detection circuit for detecting the reflection light amount from the optical disk during recording is provided, and the level of the reflection light amount detected by the reflection light amount detection circuit is set to an optimum value or a predetermined value. The feature is that the tracking actuator drive voltage that satisfies is set as the optimum tracking actuator drive voltage. With this configuration, when recording in the test writing area, the reflected light amount detection circuit detects the reflected light amount from the disk. The offset voltage when the detected level of reflected light is optimal or satisfies a predetermined value is adjusted to the optimal offset. It can be obtained satisfactorily as a voltage.

Next, according to a twelfth aspect of the present invention, in the trial writing area, the drive voltage applied to the feed motor is cut off by the cutoff circuit, so that the objective lens is deviated for recording and optimized. An optical disc device for detecting a tracking actuator drive voltage, comprising a storage circuit for holding the optimum tracking actuator drive voltage, and holding the optimum tracking actuator drive voltage in the storage circuit when the optimum tracking actuator drive voltage is detected. In the meantime, when the optical disk device is started thereafter, the optimum tracking actuator drive voltage stored in the storage circuit is called, and the tracking actuator drive voltage matches the optimum tracking actuator drive voltage. Sets the output voltage of the offset voltage circuit. It is obtained by said to,
According to this configuration, since the optimum offset voltage is stored in the storage circuit, only the optimum offset voltage needs to be called at the time of recording, and the test writing operation does not have to be performed every time.

According to a thirteenth aspect of the present invention, in the optical disk device according to the twelfth aspect, the optimum tracking actuator driving voltage held in the storage circuit is changed when a certain period has elapsed, or It is characterized in that it is updated when the operating environment temperature of the optical pickup and the attitude of the optical disc device change, and according to this configuration, it is possible to accurately update only when the optimum offset voltage may change. The optimal offset voltage can be updated.

According to a fourteenth aspect of the present invention, in the optical disk device according to the twelfth aspect, the storage circuit holds an optimum tracking actuator drive voltage corresponding to a predetermined attitude of the optical disk device in advance. When determining the attitude of the optical disk device, re-acquiring the optimal tracking actuator drive voltage, comparing the optimal tracking actuator drive voltage held in the storage circuit and the re-acquired optimal tracking actuator drive voltage, The attitude corresponding to the optimal tracking actuator drive voltage that is coincident with or closest to the optimal tracking actuator drive voltage acquired again is determined as the current attitude of the optical disc device. According to this, the light di It can be satisfactorily determine the current orientation of the click device.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. (Embodiment 1) In FIG. 1, reference numeral 1 denotes an optical disk, and reference numeral 2 denotes an optical pickup for irradiating the optical disk 1 with a laser beam and receiving reflected light. The optical pickup 2 includes a light source 3 composed of, for example, a semiconductor laser and an optical system, and an objective lens 4 for focusing output light of the light source 3 on the optical disc 1.
And a tracking actuator 5 for driving the objective lens 4 in a direction crossing the tracks of the optical disc 1. The tracking actuator 5 is driven by a tracking actuator drive circuit 6 such as a power driver IC. Reference numeral 7 denotes a feed motor that drives a feed mechanism that sends the optical pickup 2 in a direction crossing the track, and is driven by a feed motor drive circuit 8. Reference numeral 9 denotes a photodetector that receives the reflected light from the optical disc 1 and converts it into a voltage signal. An RF detection circuit 10 generates an RF signal from a signal input from the photodetector 9.

A detection circuit 11 detects a maximum value, a minimum value, and an average value of the RF signal generated by the RF detection circuit 10. A decoder 12 decodes the RF signal generated by the RF detection circuit 10, performs jitter measurement, and performs error counting. A servo signal processing circuit 13 includes a tracking error signal from a signal input from the photodetector 9 and address information of a recordable optical disk, for example, a CD-ROM.
In the case of R or CD-RW, it is possible to extract ATIP (Absolute Time In Pregroove) information embedded in the optical disc 1 in advance. Reference numeral 14 denotes a CPU which controls the entire optical disc apparatus and calculates an asymmetry and a modulation degree from the maximum value, the minimum value, and the average value of the RF signal output from the detection circuit 11. Reference numeral 15 denotes a storage device, for example, a nonvolatile memory such as a flash ROM. Reference numeral 16 denotes a temperature detection circuit, which converts a change in the resistance value of a temperature detection element 17 such as a temperature-sensitive resistor incorporated in the optical pickup 2 into a voltage signal, which is detected by an A / D converter. The temperature is input to the CPU 14 to detect the temperature. In FIG. 2, the output light from the light source 3 shows a Gaussian distribution and is usually designed to have a sufficient beam diameter with respect to the effective diameter of the objective lens 4.

In FIG. 3, reference numeral 18 denotes a servo amplifier, which amplifies a comparison output between the input tracking error signal and the reference voltage, and performs a filtering process by a tracking loop filter 19. Reference numeral 20 denotes an offset voltage circuit, which is a voltage source such as a D / A converter, and can set an arbitrary voltage. Reference numeral 21 denotes a feed loop filter that performs a filtering process on the tracking actuator drive signal and generates a feed motor drive voltage. In FIG. 4, reference numeral 22 denotes a cutoff circuit, which cuts off the feed motor drive voltage input to the feed motor drive circuit 8 by fixing the feed motor drive voltage to a reference voltage. A voltage detection circuit 23 such as an A / D converter detects a tracking actuator drive voltage.

A general optical disk device is an optical disk 1
A tracking actuator 5 and a feed mechanism are provided in order for the optical pickup 2 to follow the track. The tracking actuator 5 has a higher followability than the feed, but has a narrow movable range. On the other hand, the feed mechanism can move the optical pickup 2 from the inner circumference to the outer circumference of the disk, but has lower tracking performance than the tracking actuator 5. When reproducing and recording the optical disc 1 from the inner circumference to the outer circumference, the tracking actuator 5 is driven to move the objective lens 4 toward the outer circumference side from the neutral position, that is, the state where the tracking actuator 5 is not driven. After shifting by an amount, the optical pickup 2 is moved in the outer peripheral direction by the feed mechanism, and a series of operations of returning the objective lens 4 to the neutral position is repeated, thereby following the track.

As shown in FIG. 2, since the output light from the light source 3 has a Gaussian distribution, it is desirable that the objective lens 4 be driven near the optical axis center with the optical axis center at a neutral position. If the neutral position of the objective lens 4 is extremely deviated from the center of the optical axis, the shape of the beam spot emitted from the objective lens 4 will be distorted, and the amount of light will be reduced. Exert. Normally, the neutral position of the objective lens 4 is designed to coincide with the center of the optical axis. However, the position of the objective lens 4 may deviate due to the assembly accuracy of the optical pickup 2. Further, since the optical pickup 2 is often designed on the premise that the optical disc device is used horizontally, for example, when the optical pickup device is used vertically so that the outer periphery of the optical pickup is downward, Naturally, it is conceivable that gravity acts on the objective lens 4 and the neutral position of the objective lens 4 is shifted toward the outer peripheral side with respect to the optical axis center.

The tracking error signal is generated as an unbalanced signal of the reflected light received by the photo detector 9 of the optical pickup 2. Optical pickup 2 is optical disc 1
In this case, the tracking error signal level coincides with the reference voltage. However, when the optical pickup 2 shifts with respect to the track, the tracking error signal level fluctuates with respect to the reference voltage. Therefore, the difference is amplified by the servo amplifier 18 and the output is filtered by the tracking loop filter 19. As a result, a tracking actuator drive voltage is generated. The feed motor drive voltage is generated by extracting a low frequency component of the tracking actuator drive voltage by the feed loop filter 21. The tracking actuator drive voltage and the feed motor drive voltage are input to the tracking actuator drive circuit 6 and the feed motor drive circuit 8, respectively, and drive the tracking actuator 5 and the feed motor 7 to cause the optical pickup 2 to follow the track again. Will be.

As the recording type optical disk 1, for example, a CD
-R and CD-RW are known, and CD-R and CD-RW have a PCA (Power Calibration) for detecting an optimum recording power on an inner circumference than a data area.
A test writing area called Area) is prepared. Generally, in PCA, after changing the recording power and recording, the optimum recording power is detected from the asymmetry and modulation degree of the RF signal obtained by reproducing the recorded portion.

Here, a conventional method as a comparative example of the present invention will be described below with reference to FIGS. 1, 2 and 5. FIG. In the conventional method, an offset voltage circuit 20 for applying an offset voltage to the tracking error signal is provided so that the tracking error signal level can be changed. Therefore, the tracking position of the optical pickup 2 is shifted with respect to the track of the optical disc 1. can do. In order to optimize the shift amount of the optical pickup 2 with respect to this track, the offset voltage output from the offset voltage circuit 20 is stepwise changed in a test writing area prepared on the recordable optical disk 1 while the recording power is constant. Record while changing. And after this, the recording area is played back,
A β (asymmetry: symmetry) value is calculated from the obtained RF signal, an offset voltage at which the best β value is obtained is detected, and the detected offset voltage is added to the tracking error signal. However, when an offset voltage is added to the tracking error signal, the tracking actuator drive voltage obtained from this signal is also used as a feed motor drive voltage, and only the objective lens 4 cannot be driven. If the neutral position of 4 is shifted from the center of the optical axis, the spot shape of the irradiated beam will be distorted, the output light quantity will decrease, and the reproduction and recording quality will deteriorate.

Next, an embodiment of the invention corresponding to the contents described in claims 1 and 2 of the present invention will be described with reference to FIGS.
This will be described below with reference to FIG. The servo amplifier 18 of the optical disk device of the present invention amplifies a comparison output between the tracking error signal to which no offset voltage is applied and the reference voltage. Further, the optical disc device is provided with an offset voltage circuit 20 for applying an offset voltage to the tracking actuator drive voltage, and by changing the offset voltage, it is possible to drive the tracking actuator 5 and shift the position of the objective lens 4. Have been.

Hereinafter, a method for detecting the optimum position of the objective lens 4 will be described. For example, CD-R and CD-
In the case of RW, in the PCA which is the test writing area, the offset voltage output from the offset voltage circuit 20 is changed stepwise while the recording power is constant, and the tracking actuator 5 is driven stepwise so that the objective lens is driven. 4 is biased and recorded. During recording, the servo signal processing circuit 13 extracts the ATIP information embedded in the optical disc 1 in advance, and acquires the relationship between the set offset voltage and the extracted ATIP information and the detected address information. . After the recording, the recording area is reproduced, and the reflected light input to the photodetector 9 is used to reproduce the RF.
The detection circuit 10 detects the RF signal, and the maximum value, minimum value, and average value of the detected RF signal are detected by the detection circuit 11, and the detected maximum value, minimum value, and average value indicate the symmetry of the RF signal. The β (asymmetry) value and the modulation factor indicating the amplitude are represented by C
Calculated by PU14. Further, the decoder 12
Calculate the signal jitter and error rate. Calculated β,
When the degree of modulation takes the maximum value, or when the jitter and error rate take the minimum values, the position of the objective lens 4 is optimal, so the address at that time is obtained. And
The offset voltage corresponding to this address is derived from the relationship between the offset voltage and the address obtained in advance, and is set as the optimum offset voltage.
When performing a recording operation, the optimum offset voltage is set in the offset voltage circuit 20.

With this configuration, it is possible to record the data by shifting the position of the objective lens 4 stepwise in the direction crossing the track with respect to the output light of the light source 3 and to achieve the optimum recording state. Position can be obtained.

(Embodiment 2) Next, claim 3 of the present invention
An embodiment of the invention corresponding to the contents described in the above will be described with reference to FIGS.

In the test writing area, while the recording power is constant, the offset voltage output from the offset voltage circuit 20 is changed stepwise, and the tracking actuator 5 is driven stepwise so that the objective lens 4 is deflected. The recording is the same as in the above embodiment.
However, when recording with the objective lens 4 deviated, an initial offset voltage is set in the offset voltage circuit 20 in advance, and the position of the objective lens is deviated to the inner peripheral side or the outer peripheral side. If this state is set as an initial state and the position of the objective lens is deviated to the inner circumference, the offset voltage is changed so that the objective lens 4 is deviated to the outer circumference during recording, and conversely, is shifted to the outer circumference. In such a case, during recording, the offset voltage is changed so as to be shifted toward the inner periphery.
As described above, by preliminarily deviating the initial position of the objective lens 4, it is possible to deviate the objective lens 4 step by step within a range including the optical axis center.

According to this configuration, since the objective lens 4 is prevented from being deviated only within the range not including the center of the optical axis, it is possible to reliably obtain the position of the objective lens 4 in an optimum recording state. , Reliability is improved.

(Embodiment 3) Next, claim 4 of the present invention will be described.
An embodiment of the invention corresponding to the contents described in the above will be described with reference to FIGS.

In this optical disk apparatus, recording is performed in a test writing area with a constant recording power, and when an optimum offset voltage is detected, it is determined whether or not the recording area is optimum after reproduction by reproducing the recording area after recording. rather than,
The determination is made based on the reflected light from the optical disc 1 during recording. For example, in the case of a CD-R or CD-RW, during recording, a write pulse output from the optical pickup 2 is received by the photodetector 9 as reflected light, and its waveform is detected by the RF detection circuit 10 and detected by the detection circuit. In step 11, in addition to the maximum and average values of the reflected light, the level of the reflected light from the pit portion called the B level in the case of CD-R is detected.

In this configuration, when the maximum value and the average value of the reflected light take the maximum values, the intensity of the output light from the optical pickup 2 is the maximum, so that it can be determined that the position of the objective lens 4 is optimal. . Further, when the value obtained by normalizing the B level of the reflected light with the maximum value takes the smallest value, the reflectance from the pit is the lowest, and the pit formation state is optimal. I can judge. Therefore, the maximum value and average value of the reflected light are the largest, or
When the value obtained by normalizing the B level with the maximum value takes the smallest value, the offset voltage set in the offset voltage circuit 20 is set as the optimum offset voltage. This also makes it possible to satisfactorily obtain the optimum offset voltage. (Embodiment 4) Next, an embodiment of the invention corresponding to the contents described in claims 5 and 6 of the present invention will be described with reference to FIGS.
This will be described with reference to FIG.

In this embodiment, in an optical disc apparatus for recording with a constant recording power in a test writing area and detecting an optimum offset voltage, a storage circuit 15 for holding the optimum offset voltage is provided. In advance,
When the optical disc device performs a reproducing or recording operation, the optimum offset voltage stored in the storage circuit 15 is called, and the optimum offset voltage is set in the offset voltage circuit 20. The optimum offset voltage held in the storage circuit 15 is updated after a certain period of time, taking into account the deterioration of the optical pickup 2 due to aging. The optical pickup 2 has a temperature detecting element 17 incorporated therein.
For example, when the temperature detecting element 17 is a temperature-sensitive resistor, the temperature can be detected by the temperature detecting circuit 16 from a change in resistance, and the temperature can be updated when a change in the operating environment temperature is detected. When the installation posture of the optical disk device is changed from a horizontal posture to a vertical posture, for example, the CPU 14
By reversing the polarity of the attitude signal input to the port No. 1 with a switch or the like, a change in attitude can be detected and updated again.

According to this configuration, while the optimum offset voltage held in the storage circuit 15 is normally set quickly, when a certain period has elapsed or when a change in the operating environment temperature is detected, When the installation posture changes, an optimum offset voltage corresponding to the changed state can be obtained. (Embodiment 5) Next, an embodiment of the invention corresponding to the contents described in claim 7 of the present invention will be described with reference to FIGS.
This will be described with reference to FIG.

In this embodiment, in an optical disk device in which recording is performed at a constant recording power in the test writing area, an optimum offset voltage is detected, and the value is stored in the storage circuit 15, the optical disk device is previously used. The optimum offset voltage for the case where the optical pickup is placed horizontally and the case where the optical pickup is placed vertically so that the outer peripheral side of the optical pickup faces downward, for example, are stored in the storage circuit 15.

When the optical disk device is placed vertically,
Naturally, gravity acts on the objective lens 4, so that the neutral position of the objective lens 4 is shifted. The optimum offset voltage differs between horizontal and vertical arrangements for correcting the bias due to gravity. Utilizing the offset voltage difference due to this difference in attitude, the attitude of the optical disk device is determined.

When it is desired to detect the posture, the optimum offset voltage is detected by a series of processing in the test writing area, and is compared with the values held in advance in the horizontal and vertical positions. For example, when the value of the detected optimum offset voltage matches the value of the horizontal setting previously stored in the storage circuit 15 or is closer to the value of the horizontal setting compared to the value of the vertical setting. The current attitude of the optical disk device can be determined to be horizontal.

Using the result of this determination, various operations can be performed while distinguishing between the case where the attitude of the optical disk device is horizontal and the case where it is vertical. For example, when driving a tray for loading and unloading the optical disc 1, it is desirable to increase the drive torque of the tray in the case of vertical placement than in the case of horizontal placement, so the drive torque is adjusted in accordance with various determined postures. For example, various control operations suitable for each posture can be performed.

(Embodiment 6) Next, an embodiment of the invention corresponding to the contents described in claims 8 and 9 of the present invention will be described with reference to FIGS. 1, 2 and 4. FIG.

The optical disk device of the present invention includes an offset voltage circuit 20 for applying an offset voltage to the tracking actuator drive voltage, a cutoff circuit 22 for interrupting the feed motor drive voltage and fixing the reference voltage, and detecting the tracking actuator drive voltage. And a voltage detection circuit 23.

The method for detecting the optimal position of the objective lens 4 will be described below. For example, if the optical disc 1 is C
In the case of DR or CD-RW, a PC that is a trial writing area
In A, when recording with a constant recording power,
The cutoff circuit 22 switches the feed motor drive voltage to the reference voltage, and cuts off the drive signal to the feed motor 7. At this time, since the drive of the feed motor is stopped, the tracking servo follows only by the drive of the tracking actuator, that is, only by the deviation of the objective lens 4. During recording, the servo signal processing circuit 13 extracts the ATIP information embedded in the optical disc 1 in advance, and determines the relationship between the tracking actuator drive voltage detected by the voltage detection circuit 23 and the address information detected from the extracted ATIP information. Get it.

After recording, the recording area is reproduced, and from the reflected light input to the photodetector 9, the RF detection circuit 10
F signal is detected, and the maximum value, the minimum value of the detected RF signal,
The average value is detected by the detection circuit 11, and the CPU 14 calculates a β (asymmetry) value indicating the symmetry of the RF signal and a modulation factor indicating the amplitude from the detected maximum value, minimum value, and average value.
The decoder 12 calculates the jitter and error rate of the RF signal.

When the calculated β and the degree of modulation take the maximum values,
Or, when the jitter and error rate take the minimum value,
Since the position of the objective lens 4 is optimal, the address at that time is obtained. Then, the tracking actuator drive voltage corresponding to this address is derived from the relationship between the previously obtained tracking actuator drive voltage and the address, and is set as the optimal tracking actuator drive voltage. , So that the tracking actuator drive voltage matches the optimal tracking actuator drive voltage,
The offset voltage circuit 20 is set.

According to this configuration, it is also possible to record by shifting the position of the objective lens 4 stepwise in the direction crossing the track with respect to the output light of the light source 3, and to achieve the objective lens in an optimum recording state. 4 positions can be obtained.

(Embodiment 7) Next, claim 1 of the present invention will be described.
Embodiments of the invention corresponding to the contents described in FIG. 0 will be described with reference to FIGS.

In this optical disk device, in the test writing area, the drive of the feed motor 7 is stopped by fixing the feed motor drive voltage to the reference voltage by the cutoff circuit 22 while the recording power is constant, and the tracking follows. The recording is performed with the objective lens 4 deflected so that the tracking operation is performed only by the tracking actuator drive. In this case, an initial offset voltage is set in the offset voltage circuit 20 in advance, and the position of the objective lens 4 is biased toward the inner peripheral side. If this state is set as an initial state, since the objective lens 4 follows the track, the position of the objective lens 4 is deviated in the outer peripheral direction, and is always within a range including the optical axis center.
The objective lens 4 can be biased.

According to this configuration, since the objective lens 4 is prevented from being deviated only within a range not including the center of the optical axis, it is possible to reliably obtain the position of the objective lens 4 in an optimum recording state. , Reliability is improved.

(Embodiment 8) Next, claim 1 of the present invention will be described.
An embodiment of the invention corresponding to the content described in No. 1 will be described with reference to FIGS. 1, 2, and 4. FIG.

In this optical disk device, the drive of the feed motor 7 is stopped by fixing the feed motor drive voltage to the reference voltage by the cutoff circuit 22 in the test writing area while the recording power is constant, and the tracking follows. The recording is performed with the objective lens 4 deflected so that the tracking operation is performed only by the tracking actuator drive. And
When detecting the optimum tracking actuator drive voltage, it is determined not from the parameter obtained by reproducing the recording area after recording but from the reflected light from the optical disc 1 during recording.

For example, if the optical disk 1 is a CD-R or a CD-R
In the case of RW, during recording, a write pulse output from the optical pickup 2 is received by the photodetector 9 as reflected light, and its waveform is detected by the RF detection circuit 10, and the maximum value of the reflected light is detected by the detection circuit 11. , Average, CD
In the case of -R, a light pulse reflected light level from a pit portion called a B level is detected.

When the maximum value and the average value of the reflected light take the largest values, the intensity of the output light from the optical pickup 2 is the maximum, so that it can be determined that the position of the objective lens is optimal. When the value obtained by normalizing the B level of the reflected light with the maximum value takes the smallest value, the reflectance from the pit is the lowest and the pit formation state is optimal.
Can be determined to be optimal. Therefore, when the maximum value and average value of the reflected light are the largest, or the value obtained by normalizing the B level with the maximum value is the smallest value, the tracking actuator drive voltage detected by the voltage detection circuit 23 is adjusted to the optimum tracking actuator. Drive voltage.
This also makes it possible to satisfactorily obtain the optimum offset voltage. (Embodiment 9) Next, an embodiment of the invention corresponding to the contents described in claims 12 and 13 of the present invention will be described with reference to FIGS.

In this embodiment, in an optical disc apparatus for recording with a constant recording power in a test writing area and detecting an optimum tracking actuator drive voltage, a storage for holding the optimum tracking actuator drive voltage. A circuit 15 is provided. Then, when the optical disc apparatus performs a reproducing or recording operation, the optimum tracking actuator drive voltage stored in the storage circuit 15 is called, and an offset voltage circuit is set so that the tracking actuator drive voltage matches the optimal tracking actuator drive voltage. 20 offset voltages are set.

In this case, the optimum tracking actuator drive voltage stored in the storage circuit 15 is updated after a certain period has elapsed, in consideration of the deterioration of the optical pickup 2 due to aging. Also, the optical pickup 2 has
A temperature detecting element 17 is incorporated. For example, in the case of a temperature-sensitive resistor, the temperature can be detected by the temperature detecting circuit 16 from a change in resistance, and the temperature can be updated when a change in the operating environment temperature is detected. When the installation attitude of the optical disk device is changed from the horizontal attitude to the vertical attitude, for example, the polarity of the attitude signal input from the outside to the port of the CPU 14 is reversed by a switch or the like, and the change in the attitude is detected. It can also be updated.

According to this configuration, while the optimum offset voltage held in the storage circuit 15 is normally set quickly, when a certain period has elapsed or when a change in the operating environment temperature is detected, When the installation posture changes, an optimum offset voltage corresponding to the changed state can be obtained. Embodiment 10 Next, an embodiment of the present invention corresponding to the contents described in claim 14 of the present invention will be described with reference to FIGS.
This will be described with reference to FIG.

In this embodiment, in an optical disk apparatus in which recording is performed with a constant recording power in the test writing area, an optimum tracking actuator drive voltage is detected, and the value is stored in the storage circuit 15, The optimum tracking actuator drive voltage when the device is placed horizontally and when the optical pickup is placed vertically so that the outer periphery of the optical pickup is directed downward, for example, is held. When the optical disk device is placed vertically, gravity acts on the objective lens 4, so that the neutral position of the objective lens is shifted. The optimal tracking actuator drive voltage differs between horizontal and vertical placements to correct for the bias due to gravity. Utilizing the tracking actuator drive voltage difference due to the difference in attitude, the attitude of the optical disk device is determined. When the posture is to be detected, the optimal tracking actuator drive voltage is detected by a series of processes in the test writing area, and is compared with the previously held values for horizontal and vertical placement. Then, for example, the detected value of the optimum tracking actuator drive voltage matches the value of the horizontal setting previously stored in the storage circuit 15 or is closer to the value of the horizontal setting as compared with the value of the vertical setting. In this case, the current attitude of the optical disk device can be determined to be horizontal.

According to this embodiment, as in the case of the fifth embodiment, various operations suitable for the posture are performed while distinguishing the posture of the optical disk device between the horizontal position and the vertical position. be able to.

[0067]

As described above, according to the optical disk apparatus of the present invention, only the position of the objective lens can be arbitrarily deviated with respect to the output light of the light source. (The parameters obtained by reproducing the recording area or the parameters obtained from the reflected light during recording) can be used to detect the optimal objective lens position. Therefore, the optimal objective lens position can be accurately detected. Correction of the lens position can be performed accurately. Therefore, the position of the objective lens is deviated from the center of the optical axis due to poor assembly accuracy of the optical pickup, or the position of the objective lens is deviated from the center of the optical axis due to a change in the installation posture of the optical disk device. However, the objective lens position can be corrected to the optimal objective lens position, and as before, the spot shape of the beam output from the optical pickup is distorted and the output light quantity is reduced, which adversely affects the reproduction / recording quality. Thus, the reliability of the optical disk device can be improved.

[Brief description of the drawings]

FIG. 1 is a diagram schematically showing an optical disk device according to an embodiment of the present invention.

FIG. 2 is a diagram showing a main part of the optical disc device and an intensity distribution of output light from a light source.

FIG. 3 is a diagram showing a tracking drive circuit of the optical disc device.

FIG. 4 is a diagram showing a tracking drive circuit of an optical disc device according to another embodiment of the present invention.

FIG. 5 is a diagram showing a tracking drive circuit of a conventional optical disk device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Optical disk 2 Optical pickup 3 Light source 4 Objective lens 5 Tracking actuator 6 Tracking actuator drive circuit 7 Feed motor 8 Feed motor drive circuit 9 Photodetector 10 RF detection circuit 11 Detection circuit 12 Decoder 13 Servo signal processing circuit 14 CPU 15 Storage circuit 16 Temperature detection Circuit 17 Temperature detection element 18 Servo amplifier 19 Tracking loop filter 20 Offset voltage circuit 21 Feed loop filter 22 Cutoff circuit 23 Voltage detection circuit

Claims (14)

[Claims] 1. An optical disc apparatus for performing test writing in a test writing area provided on a recordable optical disc by an optical pickup having an objective lens, and detecting an optimum recording condition based on a result of the test writing. A tracking actuator that drives the objective lens position of the optical pickup in a direction crossing a track with respect to output light from a light source of the optical pickup; and an offset voltage circuit that adds an offset voltage to a drive voltage applied to the tracking actuator. In the test writing area, with the recording power kept constant, the output voltage of the offset voltage circuit is changed stepwise while the objective lens position is deviated and recorded, and then the objective lens position is deviated. The recorded area is reproduced, and the offset As the optimal offset voltage the output voltage of the circuit, the optical disk apparatus characterized in that added to the tracking actuator driving voltage. 2. In the test writing area, after the output voltage of the offset voltage circuit is changed stepwise to record while shifting the position of the objective lens, the recording state of the recording portion is
An output voltage value of an offset voltage circuit corresponding to a recording state in which one or more of the parameters satisfy an optimum value or a predetermined value, which is determined by parameters of symmetry, level, jitter or error rate of a reproduced RF signal. 2. The optical disk apparatus according to claim 1, wherein the offset voltage is an optimum offset voltage. 3. In a test writing area, when recording by shifting the output voltage of the offset voltage circuit stepwise to shift the position of the objective lens, the offset voltage circuit previously applies the offset voltage to the tracking actuator drive voltage by the offset voltage circuit. Is added, and the position of the objective lens is shifted toward the inner circumference or outer circumference of the disc with respect to the optical axis center of the light source, so that the objective lens position can be changed in an arbitrary range including the optical axis center. The optical disk device according to claim 1, wherein the optical disk device is biased. 4. In a test writing area, when the output voltage of the offset voltage circuit is changed stepwise to record while the position of the objective lens is deviated, the reflected light amount detection for detecting the reflected light amount from the optical disk during recording. With a circuit,
The level of the reflected light amount detected by the reflected light amount detection circuit is
2. The optical disk device according to claim 1, wherein an output voltage value of the offset voltage circuit that satisfies an optimum value or a predetermined value is set as an optimum offset voltage. 5. An optical disk device for recording by shifting the output voltage of an offset voltage circuit stepwise in a test writing area to shift an objective lens position and to detect an optimum offset voltage, wherein the optimum offset voltage is held. A storage circuit that stores the optimum offset voltage when the optimum offset voltage is detected, and stores the optimum offset voltage stored in the storage circuit when the optical disk apparatus is started thereafter. 2. The optical disk device according to claim 1, wherein a voltage is called and added to the tracking actuator drive voltage. 6. The optimum offset voltage stored in the storage circuit is updated when a certain period of time has elapsed, or when the operating environment temperature of the optical pickup and the attitude of the optical disk device have changed. The optical disk device according to claim 5, wherein 7. An optimum offset voltage corresponding to a predetermined attitude of an optical disk device is previously stored in a storage circuit.
When determining the attitude of the optical disc device, the optimum offset voltage is obtained again, the optimum offset voltage held in the storage circuit is compared with the optimum offset voltage obtained again, and the optimum offset voltage obtained again is obtained. 6. The optical disk device according to claim 5, wherein an attitude corresponding to the optimal offset voltage held in the storage circuit that is the same as or closest to the offset voltage is determined as a current attitude of the optical disk apparatus. 8. An optical disc apparatus for performing test writing in a test writing area provided on a recordable optical disc by an optical pickup having an objective lens, and detecting an optimum recording condition based on a result of the test writing. A feed motor that drives a feed mechanism that sends the optical pickup in the radial direction of the disk, a cutoff circuit that cuts off a drive voltage applied to the feed motor, a voltage detection circuit that detects the tracking actuator drive voltage, An offset voltage circuit for adding an offset voltage to a voltage, wherein the drive voltage applied to the feed motor is cut off by the cutoff circuit, so that the tracking servo follows the deviation of the objective lens. Constant write power in the writing area The tracking actuator drive voltage is detected by the voltage detection circuit during recording, and after recording, the recorded area is reproduced by shifting the position of the objective lens. An optical disk device, wherein an output voltage of the offset voltage circuit is set such that a tracking actuator drive voltage is an optimum tracking actuator drive voltage and the tracking actuator drive voltage matches the optimal tracking actuator drive voltage. 9. In a test writing area, after a drive voltage applied to a feed motor is cut off by a cutoff circuit, an objective lens is deviated and recording is performed. Judgment is made based on level, jitter or error rate, and a detection voltage value of a voltage detection circuit corresponding to the recording state such that one or more of the parameters satisfies an optimum value or a predetermined value is determined as an optimum tracking actuator drive voltage. The optical disk device according to claim 8, wherein: 10. In a test writing area, when a drive voltage applied to a feed motor is cut off by a cut-off circuit so that an objective lens is deviated for recording, the offset voltage circuit previously adds the offset voltage to the tracking actuator drive voltage by an offset voltage circuit. Is added, and the position of the objective lens is shifted toward the inner circumference of the disc with respect to the center of the optical axis of the light source, thereby displacing the position of the objective lens in an arbitrary range including the center of the optical axis. The optical disk device according to claim 8, wherein: 11. A reflected light amount for detecting a reflected light amount from an optical disc during recording when recording by biasing an objective lens by cutting off a drive voltage applied to a feed motor by a cutoff circuit in a test writing area. A detection circuit is provided, and a tracking actuator drive voltage such that the level of the reflected light amount detected by the reflected light amount detection circuit satisfies an optimum value or a predetermined value is set as an optimum tracking actuator drive voltage. 9. The optical disc device according to 8. 12. A drive voltage applied to a feed motor is cut off by a cutoff circuit in a test writing area,
In an optical disc apparatus for recording by deviating an objective lens and detecting an optimum tracking actuator driving voltage, a storage circuit for holding the optimum tracking actuator driving voltage is provided, and when the optimum tracking actuator driving voltage is detected, Is stored in the storage circuit, and when the optical disk device is started thereafter, the optimum tracking actuator driving voltage stored in the storage circuit is called, and the tracking actuator driving voltage is changed to the optimum tracking actuator driving voltage. 9. The optical disk device according to claim 8, wherein an output voltage of the offset voltage circuit is set so as to match a voltage. 13. The optimum tracking actuator drive voltage stored in the storage circuit is updated when a certain period of time elapses, or when the operating environment temperature of the optical pickup or the attitude of the optical disk device changes. 13. The optical disk device according to claim 12, wherein: 14. An optimum tracking actuator drive voltage corresponding to a predetermined attitude of an optical disk device is previously stored in a storage circuit, and the optimum tracking actuator drive voltage is obtained again when determining the attitude of the optical disk device. Then, comparing the optimal tracking actuator drive voltage held in the storage circuit and the optimal tracking actuator drive voltage acquired again,
13. The method according to claim 12, wherein a posture corresponding to the optimal tracking actuator drive voltage that is coincident with or closest to the optimal tracking actuator drive voltage acquired again is determined as a current posture of the optical disc apparatus. An optical disk device as described in the above.