JP2013218759A - Optical disk device and optical disk record presence determination method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce erroneous determination in determining whether it is recorded or unrecorded.SOLUTION: When a timeout error occurs due to a seek retry, a DSP 32 lowers an upper detection threshold value in a step 12, and after confirming that the value is within a predetermined effective range in a step 14, lowers the changed upper detection threshold value gradually until the value becomes smaller than an RF envelope in a step 16. Therefore, if an area is a recorded area, an optimum threshold value according to the type can be set, thereby reducing the frequency of erroneous determination of the recorded area as an unrecorded area.

Description

  The present invention relates to an optical disc apparatus and an optical disc recording presence / absence judgment method for judging whether a recording area of an optical disc is recorded or not.

In an optical disc apparatus for reproducing and recording an optical disc, an ASENV signal indicating whether or not the optical disc has been recorded is generated based on a signal level of a so-called RF signal. As techniques related to the ASENV signal, Patent Documents 1 to 4 shown below are known.
Patent Document 1 discloses an apparatus for accessing a recording medium, and at least one of address information mainly represented by a shape previously formed on the recording medium and address information recorded together with data on the recording medium. Discloses an apparatus for accessing a recording medium using a computer.
In paragraph 0150 of the specification of the publication, “when it is determined as an unrecorded area, the ASENVDT signal is in a LOW state .... when it is determined as a recorded area, the ASENVDT signal is in an HI state. The threshold value may be, for example, 80% of the maximum value detected in a predetermined section, and the predetermined number of consecutive times used for determining the recorded area and the unrecorded area may be, for example, two times. is there.

Patent Document 2 discloses an optical information recording / reproducing apparatus, which mainly records information on an optical disc having concentric or spiral tracks on the information recording surface, and reproduces the recorded information. The present invention relates to a recording / reproducing apparatus, and more particularly, to a measure against track skipping in an optical information recording / reproducing apparatus using tracking servo control by a push-pull method.
Paragraph 0038 in the specification of this publication states that “to measure the TE symmetry of the boundary portion, land before the boundary portion and release the hold track (t = τ1). The envelope of the RF signal has a predetermined level. There is a disclosure that “the end of the recording area is searched while looking at the ASENV signal that goes to a high level when it exceeds”.

Further, Patent Document 3 discloses an optical disk device, and in particular, the DSP 32 discloses a technique for prohibiting the movement of the optical pickup unit 16 when the RE signal value based on this sub beam falls below a threshold value.
In paragraph 0083 of the specification of the publication, “when the detection value based on the sub beam S1 falls below the threshold, the movement of the optical pickup unit 16 is prohibited. As a result, the main beam M is likely to enter the unrecorded area. Sometimes the optical pickup unit 16 is immediately fixed, so that the main beam M can be prevented from entering the unrecorded area, or the amount of entry can be reduced even if it enters.

Patent Document 4 discloses an optical disk device, a control method of the optical disk device, and the like, and is applied to an optical disk device that accesses a changeable optical disk, and is applied to recording and reproduction of various types of data, and waits for a long time. In this case, the error rate can be easily avoided.
Paragraph 0035 in the specification of the publication discloses that “unrecorded areas are detected with reference to the signal level of the reproduction signal RF within a predetermined detection range from the standby position A0 specified by the standby command”.

Table 2007/105723 JP 2006-331521 A JP 2005-259185 A JP 2002-342950 A

When determining whether the recording is completed or not, the recording is performed in the recorded area and the determination is made based on the signal level of the RF signal. That is, the fixed predetermined threshold value is compared with the signal level based on the envelope of the RF signal. However, the RF signal is affected by the medium type of the optical disc, and the obtained RF signal is used after adjusting the amplitude.
For this reason, such amplitude adjustment cannot be performed before it is known that recording has been completed, and erroneous determination has occurred when determining whether recording has been performed or not.

  The present invention provides an optical disc apparatus and an optical disc recording presence / absence judgment method that reduce erroneous judgments in the judgment of recorded or unrecorded.

  The present invention is an optical disc apparatus, wherein a drive unit that rotates and drives an optical disc, and a data recording area of the optical disc that is driven to rotate by the drive unit are irradiated with a light beam, and reflected light of the reflected light beam is received. An optical pickup unit capable of tracking operation and focusing operation; a processing circuit for controlling the drive unit and the optical pickup unit; and generating an RF signal based on reflected light received by the optical pickup unit; and the data Threshold adjustment means for adjusting a threshold value for determining whether the recording area is a recorded area or an unrecorded area, the signal level of the RF signal generated by the processing circuit, and the threshold value adjusted by the threshold adjustment means are compared. , A recording presence / absence determination method for determining whether a recorded area or an unrecorded area There configured to include and.

In normal operation, when the optical disk is rotated by the drive unit, the optical pickup unit irradiates the data storage area of the optical disk rotated by the drive unit and receives the reflected light of the reflected light beam. . At this time, a tracking operation and a focusing operation are performed. The processing circuit controls the drive unit and the optical pickup unit, and generates an RF signal based on the reflected light received by the optical pickup unit. At this time, the recording presence / absence determining means compares the signal level of the RF signal generated by the processing circuit with a predetermined threshold value, and determines whether it is a recorded area or an unrecorded area.
In this way, signal reproduction and recording are performed.

On the other hand, the threshold adjustment means adjusts a threshold for determining whether the data recording area is a recorded area or an unrecorded area as necessary. Therefore, the recording presence / absence determining means compares the signal level of the RF signal generated by the processing circuit with the threshold adjusted by the threshold adjusting means to determine whether the area is a recorded area or an unrecorded area.
That is, instead of using the threshold value as it is fixed, it is possible to determine whether it is a recorded area or an unrecorded area based on a comparison between the signal level of the RF signal and the threshold value after being changed as necessary.

  According to the present invention, the threshold value is not used while being fixed, but can be changed as necessary. Conventionally, the signal level of the RF signal is weak and can only be determined as unrecorded. Even in such a case, it is possible to provide an optical disk device and an optical disk recording presence / absence determination method that can determine that recording has been correctly performed.

It is a block diagram which shows schematic structure of an optical disk apparatus. It is a flowchart corresponding to the program which changes a threshold value with an optical disk apparatus. 6 is a time chart showing a comparison between an RF signal and a threshold when an ASWNV signal is generated using the RF signal in the optical disc apparatus.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram showing an optical disc apparatus according to an embodiment of the present invention.
In the figure, the optical disc apparatus 10 has an optical pickup unit 16 provided with an optical lens 18. The optical lens 18 is supported by a tracking actuator 20 and a focus actuator 22. The laser beam light emitted from the laser diode 24 is irradiated onto the recording surface of the optical disc 50, and predetermined reflected light can be obtained.

  The optical disk 50 is mounted on the spindle 12 and is rotated by the spindle motor 14. As the optical disc 50, various optical discs such as a Blu-ray disc, DVD, CD, CD-R, DVD ± R, CD-RW, DVD ± RW, and DVD-RAM can be adopted. In any case, the reflectance of the recorded area is higher than that of the unrecorded area.

The optical pickup unit 16 is supported by the sled 16s and is movable within a predetermined range along the radial direction of the optical disc 50. As the optical disk 50 rotates, the optical disk 50 moves in the same range along the radial direction.
The arithmetic circuit 28 has a predetermined number of addition circuits and a predetermined number of subtraction circuits (both not shown), and performs predetermined operations on the outputs A to H of the detection elements 26 (26a to 26h). , TE (Tracking Error) signal, FE (Focus Error) signal, RE (Readout Error) signal, and RF (Radio Frequency) signal are generated.

That is,
TE = (A + D)-(B + C)
FE = (A + C)-(B + D)
RE = (HG)-(EF)
RF = (A + B) + (C + D)
The operation is performed.
The FE signal output from the arithmetic circuit 28 is input to a DSP (Digital Signal Processor) 32 via the A / D converter 30b. The DSP 32 executes focus servo based on the input FE signal and generates a focus control voltage. The generated focus control voltage is input to the PWM modulation circuit 34b, and the PWM modulation circuit 34b outputs a PWM signal having a pulse width corresponding to the input focus control voltage to the focus actuator 22. Thereby, the focus, that is, the position of the optical lens 18 on the optical axis is adjusted.

The TE signal output from the arithmetic circuit 28 is input to the DSP 32 via the A / D converter 30a. The DSP 32 executes tracking control processing and thread control based on the input TE signal, and generates a tracking actuator control voltage and a thread control voltage. The PWM modulation circuits 34 a and 34 c generate PWM signals having pulse widths corresponding to the tracking actuator control voltage and the thread control voltage, respectively, and output the generated PWM signals to the tracking actuator 20 and the thread motor 36. As a result, the radial position of the optical lens 18 and the rotational speed and direction of the sled motor 36 are controlled.
The DSP 32 also executes spindle servo in addition to the focus servo, tracking servo, and thread servo described above. By this servo processing, the rotation of the spindle motor 14 is controlled so that the cycle of the FG pulse output from the spindle motor 14 shows a predetermined value.

  Here, a mechanism for rotating the optical disk 50 by the spindle motor 14 corresponds to a drive unit. The optical pickup unit 16 irradiates the optical disc 50 with a laser beam as a light beam, receives the reflected light and converts it into an electrical signal. Further, a focus servo or tracking servo is controlled by a focus actuator or a tracking actuator. It is feasible and realizes tracking operation and focus operation. The DSP 32 processes the output signal from the optical pickup unit 16 based on the reflected light from the optical disc 50 and controls the drive unit and the optical pickup unit, and corresponds to a processing circuit.

  The RF signal output from the arithmetic circuit 28 is input to the DSP 32 via the A / D converter 30d. The DSP 32 reproduces a signal from the input RF signal. For example, in a DVD or Blu-ray disc, the reproduced image signal is output to the decoder 38 via the buffer 32b and subjected to decoding processing. The decoded image signal, that is, the reproduction signal is output to a TV monitor (not shown) via the adding circuit 42. The DSP 32 also performs processing of detecting address information from the supplied RF signal and temporarily holding it in the register 32r.

The RF signal is used for determining whether the area is a recorded area or an unrecorded area. That is, the signal level of the RF signal based on the reflected light is compared with a predetermined threshold value, and the DSP 32 determines whether it is a recorded area or an unrecorded area. Accordingly, the DSP 32 corresponds to a recording presence / absence determining unit.
In other words, for recording / non-recording determination, ASENV = High using a signal (ASENV) detected by setting a threshold value to a signal obtained by adjusting the amplitude of the RF signal output from the optical pickup unit 16. If it has been recorded, it is determined that it has been recorded. However, as described above, in the conventional device, even in the recorded area, ASENV = Low depending on the threshold value set as a fixed value, and it is determined as an unrecorded area.

In this embodiment, this threshold value is not a fixed value as disclosed in the conventional example, and the threshold value is changed as necessary.
As a premise, in ROPC (Running Optical Power Control), seek is basically performed in the recorded area. However, if the seek position is determined to be unrecorded, a seek retry is entered, so that timeout occurs during that time and ROPC is not performed normally.

  Generally, in the case of a recorded area, the amplitude adjustment of the RF signal is performed so that the target amplitude is obtained from the actual RF signal. However, since there is no recorded area in the case of an unrecorded area, the amplitude adjustment of the RF signal is performed with reference to the amplitude of the TE signal. Here is a factor that causes an error from the target amplitude. As a result, when the amplitude of the RF signal becomes smaller than the target amplitude, even when trying to seek to the recorded area when ROPC is executed, the seek position is determined to be unrecorded, and a seek retry is entered. The phenomenon of time-out occurs.

In this embodiment, when a timeout occurs during ROPC, the threshold for generating the ASENV signal is changed so that it can be determined as a recorded area.
FIG. 2 is a flowchart corresponding to a program for changing the threshold value in the optical disc apparatus, and FIG. 3 shows a comparison between the RF signal and the threshold value when the ASWNV signal is generated using the RF signal in the optical disc apparatus. It is a graph. In addition to the servo processing described above, the DSP 32 also executes software processing shown in FIG.

Step 10 determines whether or not the above-described timeout has occurred, and seeks to the recorded area at the time of ROPC, but it is not recorded by the comparison result between the RF signal obtained at the seek position and the threshold value. The following process is executed when a timeout error occurs during the seek retry.
First, in step 12, the upper detection threshold, which is the above-described threshold, is lowered by 1 LSB. This upper detection threshold value can be changed only within a certain range in advance, and 10 levels including an upper limit and a lower limit are planned as shown in FIG. The initial value is 0LSB as shown in FIG. 3, and takes the largest value. On the other hand, the lower limit value is 9LSB, and 8 values can be taken at equal intervals including 0LSB and 9LSB.

Since the RF signal actually has a waveform having a predetermined amplitude, it cannot be compared with a certain threshold as it is. Therefore, an RF envelope that connects adjacent maximum values and adjacent minimum values is set in consideration of the amplitude value of the RF signal, and this Rf envelope is compared with the threshold value. The process of setting the envelope also corresponds to the process of acquiring the RF signal.
Each time step 12 is executed, the upper detection threshold value gradually decreases from 0 LSB to 9 LSB, but since it is not lowered below 9 LSB, the upper detection threshold value changed in step 14 is within the valid range. It is determined whether it falls within (0LSB to 9LSB), and if it falls outside the effective range, the upper detection threshold value is returned to the initial set value in step 20. This is to determine that the cause of the timeout error is not due to the good or bad setting of the threshold value, and another countermeasure is taken.

On the other hand, if it falls within the effective range, it is determined in step 16 below whether the changed upper detection threshold value is smaller than the upper limit value of the RF envelope. If the changed upper detection threshold value is smaller than the upper limit value of the RF envelope, it is determined that there is a reflected signal from the recorded area when compared with the RF signal thereafter, that is, the area is recorded. It is determined to be an area. As a result, ASENV signal = High is set. Therefore, the above threshold value changing process is finished, and the upper detection threshold value changed in step 22 is set as a new threshold value. .
However, if the changed upper detection threshold is still larger than the upper limit value of the RF envelope, the process returns to step 12 and the above-described processing is repeated thereafter.

  When the upper detection threshold value is returned to the initial setting value in step 20 or the changed upper detection threshold value is set as a new threshold value in step 22, the threshold adjustment unit in this embodiment changes the threshold value to record the recorded area. Or the process of determining whether the area is an unrecorded area ends. According to the present invention as described above, the number of times of determining as unrecorded in the recorded area is reduced.

  By the way, the change of the threshold value is not limited to such a case. For example, there is a process of adjusting the optimum writing intensity by performing test writing in the adjustment area. In this case, although it is certain that data is written, the ASENV signal may indicate unrecorded with a threshold value that remains at the initial setting value. In such a case, the threshold value may be changed by executing the above-described processing so that the ASENV signal indicates recorded. That is, the threshold adjustment means changes the threshold and determines the presence / absence of recording.

  In this way, the DSP 32 lowers the upper detection threshold value in step 12 when a time-out error occurs due to a seek try, and confirms that the value is within a predetermined effective range, and then changes the value. Since the subsequent upper detection threshold is decreased stepwise in step 16 until it becomes smaller than the RF envelope, an optimum threshold value can be set according to the type of the recorded disc. It is now possible to reduce the number of times of erroneously determining that there is no recording in the completed area.

Needless to say, the present invention is not limited to the above embodiments. It goes without saying for those skilled in the art,
-Applying the combination of the mutually replaceable members and configurations disclosed in the above-described embodiments as appropriate-The above-described embodiments are not disclosed in the above-described embodiments, but are publicly known techniques. The members and structures that can be mutually replaced with the members and structures disclosed in the above are appropriately replaced, and the combination is changed and applied. It is an embodiment of the present invention that a person skilled in the art appropriately replaces the members and configurations that can be assumed as substitutes for the members and configurations disclosed in the above-described embodiments, and changes the combination to apply. It is disclosed as.

DESCRIPTION OF SYMBOLS 10 ... Optical disk apparatus, 12 ... Spindle, 14 ... Spindle motor, 16 ... Optical pick-up unit, 16s ... Thread, 18 ... Optical lens, 20 ... Tracking actuator, 22 ... Focus actuator, 26a-26h ... Detection element, 28 ... Arithmetic circuit , 30a to 30d ... A / D converter, 32 ... DSP, 32b ... buffer, 32r ... register, 34b ... PWM modulation circuit, 36 ... thread motor, 38 ... decoder, 42 ... adder circuit, 50 ... optical disc.

Claims (8)

An optical disk device,
A drive unit for rotating the optical disc;
An optical pickup unit that irradiates a data recording area of an optical disc that is rotationally driven by the drive unit, receives reflected light of the reflected light beam, and is capable of tracking operation and focusing operation;
A processing circuit that controls the drive unit and the optical pickup unit, and generates an RF signal based on reflected light received by the optical pickup unit;
Threshold adjustment means for adjusting a threshold for determining whether the data recording area is a recorded area or an unrecorded area;
An optical disc apparatus comprising: a recording presence / absence determining unit that compares a signal level of the RF signal generated by the processing circuit with a threshold adjusted by the threshold adjusting unit to determine whether the region is a recorded region or an unrecorded region.   2. The optical disc apparatus according to claim 1, wherein the threshold value adjusting means changes the threshold value within a predetermined range.   The optical disc apparatus according to claim 1, wherein the recording presence / absence determining unit determines the comparison by comparing an envelope of the RF signal with a threshold value.   The said threshold value adjustment means changes the said threshold value when a seek retry occurs, and determines whether it is a recorded area or an unrecorded area. Optical disk device.   5. The optical disc apparatus according to claim 1, wherein when a time-out occurs during ROPC, the threshold value is changed to determine whether the area is a recorded area or an unrecorded area.   6. The optical disc apparatus according to claim 1, wherein when performing a test write in the adjustment area, the threshold value adjusting unit changes the threshold value to determine whether or not recording is performed.   7. The optical disc apparatus according to claim 1, wherein the recording presence / absence determining unit generates an ASENV signal indicating determination of a recorded area or an unrecorded area. A drive unit that rotates an optical disk, and an optical pickup that irradiates a data storage area of the optical disk that is rotated by the drive unit, receives reflected light of the reflected light beam, and performs tracking operation and focus operation A unit, a processing circuit for controlling the driving unit and the optical pickup unit, and generating an RF signal based on reflected light received by the optical pickup unit, and a signal level of the RF signal generated by the processing circuit Is an optical disc recording presence / absence judging method for judging whether an optical disc is a recorded region or an unrecorded region in an optical disc apparatus comprising a recording presence / absence judging means for judging whether it is a recorded region or an unrecorded region. And
A threshold value for determining whether the data recording area is a recorded area or an unrecorded area is adjusted, and the adjusted threshold value is compared with the signal level of the RF signal generated by the processing circuit. An optical disc recording presence / absence determination method, characterized by:

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