JP2007323764A - Optical disk device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical disk device capable of more accurately providing optimal recording power corresponding to a recording speed. <P>SOLUTION: The optical disk device records data at a different recording speed corresponding to the radial position of an optical disk 10, wherein a control section 24 sets first optimal recording power at the recording speed of a test recording area by trial writing in the inner circumferential side test recording area of the optical disk, and calculates optimal recording power at the recording speed of the data recording area of the optical disk 10 from the first optimal recording power by using a correlation coefficient defining a relationship between optimal recording power at the recording speed of the inner circumferential side test recording area of the specific optical disk and optimal recording power at the recording speed of the outer circumferential side data recording area in the specific optical disk device. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a technique for controlling a recording laser power of a recording optical disc in an optical disc apparatus for recording / reproducing information on an optical disc.

  Conventionally, in a recordable optical disc apparatus such as a DVD-R, a process for obtaining optimum recording power called OPC (Optimum Power Control) is executed. As a method for obtaining the optimum recording power, a predetermined test recording area called PCA or DRIVE TEST ZONE, which is formed on the inner circumference side of the disc from the data recording area in which actual data is written (hereinafter referred to as inner circumference test recording area), is predetermined. There is known a method for obtaining the optimum recording power by performing trial recording for writing the data. For example, when recording is performed by increasing the recording speed toward the outer periphery of the disk as in the Zone-CLV system or the CAV system, it is necessary to obtain the optimum recording power according to each recording speed. Therefore, for example, a method is known in which the optimum recording power obtained by executing OPC in the inner periphery test recording area is multiplied by a predetermined coefficient to obtain the optimum recording power in a zone in which OPC is not executed.

  In Patent Document 1, OPC is performed at two recording speeds, the relationship of the amount of change in the optimum recording power with respect to the change in recording speed is acquired, and the recording power obtained with respect to a predetermined coefficient is obtained. There is disclosed a method of correcting the deviation of the optimum recording power in a zone where OPC is not executed by applying the correction by utilizing the relationship of the above-described change amount, thereby avoiding the influence of temperature environment and disc variation. .

  However, as the difference between the recording speed on the inner peripheral side and the recording speed on the outer peripheral side increases, the value of the predetermined coefficient increases. Therefore, for example, if the error in the optimum recording power obtained from the inner circumference test recording area is large, the error in the optimum recording power on the outer circumference side obtained based on the predetermined coefficient also increases. Further, when the laser diode wavelength of the optical pickup (OPU) and the tilt angle of the optical axis with respect to the disk surface are different for each disk device, compatibility of predetermined coefficients may not be obtained between the disk devices.

  Therefore, instead of obtaining the optimum recording power for the data recording area on the outer circumference side indirectly from the optimum recording power obtained from the inner circumference test recording area, it is determined in the outer circumference test recording area formed on the outer circumference side from the data recording area. A method is also conceivable in which trial recording is performed to write the data and the optimum recording power on the outer peripheral side is obtained. In this method, since the optimum recording power on the outer peripheral side is obtained from the test recording area formed on the outer peripheral side from the data recording area, trial recording can be performed at a speed close to the actual recording speed on the outer peripheral side. Therefore, it is expected that the optimum recording power on the outer peripheral side can be obtained with high accuracy. However, generally, in the case of commercially available discs, the outer peripheral test recording area is formed in the outermost peripheral area of the disc, and mechanical properties such as tilt, runout, eccentric gravity center, and eccentricity in the outermost peripheral area are good. In addition, since there is dye unevenness, the accuracy of the optimum recording power required from the outer periphery test recording area cannot be expected in many cases. In addition, when the optimum recording power is obtained by performing individual test recording in the inner circumference test recording area and the outer circumference test recording area each time before actual data recording is started, it takes a relatively long time to obtain the optimum recording power. And it takes a long time to start actual recording.

JP 2005-317064 A

  An object of the present invention is to provide an optical disc apparatus capable of obtaining an optimum recording power according to a recording speed with higher accuracy.

  An optical disc apparatus according to the present invention is an optical disc apparatus that performs data recording by irradiating a data recording area provided on the optical disc with laser light having an optimum recording power according to the recording speed. The specific optical disc apparatus is provided on the optical disc. A first optimum recording power with respect to a first recording speed obtained by performing test recording at a first recording speed in an inner peripheral test recording area on the inner peripheral side of the data recording area, and the specific optical disc apparatus includes the data A memory for storing a coefficient determined based on a second optimum recording power for a second recording speed obtained by performing trial recording at a second recording speed different from the first recording speed in a recording area; By performing test recording at the first recording speed in the provided inner periphery test recording area, An optimum recording power determination unit that obtains a third optimum recording power and obtains a fourth optimum recording power for the second recording speed in the data recording area based on the coefficient recorded in the memory and the third optimum recording power; It is characterized by providing.

  In one aspect of the optical disc apparatus according to the present invention, the fifth optimum recording power for the second recording speed is obtained by performing trial recording at the second recording speed in the data recording area of the optical disc, and the fourth optimum recording is performed. A correction value registration unit that obtains a correction value for correcting the coefficient based on power and the fifth optimum recording power and registers the correction value in the memory in association with the coefficient; The determining unit corrects the coefficient based on the correction value, and obtains the fourth optimum recording power based on the corrected coefficient and the third optimum recording power.

  In one aspect of the optical disc apparatus according to the present invention, the correction value registration unit sets the correction value when the similarity between the fourth optimum recording power and the fifth optimum recording power is lower than a predetermined reference value. It is obtained and registered in the memory.

  An optical disk apparatus according to the present invention is an optical disk apparatus that records data at different recording speeds according to the radial position of the optical disk, and performs test writing in the test recording area on the inner circumference side of the optical disk, thereby recording the recording speed of the test recording area. Between the optimum recording power at the recording speed of the inner peripheral side test recording area of the specific optical disc and the optimum recording power at the recording speed of the outer data recording area in the specific optical disc apparatus Means for calculating an optimum recording power at a recording speed in a data recording area of the optical disc from the first optimum recording power using a correlation coefficient that defines

  In one aspect of the optical disc apparatus according to the present invention, the correlation coefficient is a ratio of the optimum recording power at the recording speed of the outer circumference side data recording area to the optimum recording power at the recording speed of the inner circumference side test recording area. It is characterized by that.

  One aspect of the optical disk apparatus according to the present invention is characterized by comprising means for increasing or decreasing the correlation coefficient in the specific optical disk apparatus by performing trial writing in the data recording area of the optical disk.

  According to the present invention, it is possible to provide an optical disc apparatus capable of obtaining the optimum recording power corresponding to the recording speed with higher accuracy.

  The best mode for carrying out the present invention (hereinafter referred to as an embodiment) will be described below with reference to the drawings.

  FIG. 1 shows a block diagram of a main part of the optical disc apparatus according to the present embodiment. The optical disk 10 is controlled by the spindle motor 12 by the CAV method or the Zone-CLV method.

  The optical pickup unit 14 is provided facing the optical disc 10 and records data on the optical disc 10 by emitting laser light having a recording power from a laser diode (LD). Data recording may be performed by melting and sublimating a part of the recording film of the optical disc 10 to form pits, or by heating and quenching the crystalline state to transition to the amorphous state.

  At the time of data recording, the recording data is supplied to the encoder 18, and the data encoded by the encoder 18 is supplied to the LD driving unit 16. The LD drive unit 16 creates a drive signal based on the encoded data and supplies it to the LD of the optical pickup unit 14. The LD driving unit 16 is supplied with a control signal from the control unit 24, and the recording strategy and the recording power are determined by the control signal.

  On the other hand, at the time of data reproduction, the optical pickup unit 14 irradiates a laser beam with reproduction power (reproduction power <recording power) from the LD, receives the reflected light and converts it into an electrical signal to obtain a reproduction RF signal. The reproduction RF signal is supplied to the reproduction RF signal processing unit 20.

  The RF signal processing unit 20 includes an amplification amplifier, an equalizer, a binarization unit, a PLL unit, and the like, binarizes the reproduced RF signal, generates a synchronization clock, and supplies it to the decoder 22. The decoder 22 decodes data based on these supplied signals and outputs it as reproduced data.

  The reproduced RF signal from the RF signal processing unit 20 is also supplied to the control unit 24 for signal quality evaluation. At the time of data reproduction, a tracking error signal or a focus error signal is also generated to control the focus servo or tracking servo, and a wobble signal formed on the optical disk 10 is reproduced and used for address demodulation or rotation speed control. There are also circuits, but these are the same as in the prior art, so the description thereof is omitted.

  Prior to actual data recording, the control unit 24 drives the LD driving unit 16 to perform recording power optimization (OPC) according to the recording speed. OPC is performed, for example, by changing the recording power in 15 steps in 15 frames, recording test data in a predetermined area, reproducing each test data, and detecting its β value. After calculating the β value for each recording power, the control unit 24 sequentially records the β value as a function of the recording power, and selects the recording power at which a predetermined reference β value is obtained as the optimum recording power.

  Here, when the data recording is performed by increasing the recording speed toward the outer periphery of the disc as in the Zone-CLV method or the CAV method, the control unit 24 performs a relatively low inner peripheral recording speed in the inner peripheral test recording area. After obtaining the inner circumference optimum recording power, the outer circumference optimum recording power for the outer circumference recording speed higher than the inner circumference recording speed is obtained indirectly by performing calculation based on a predetermined coefficient for the inner circumference optimum recording power, In this embodiment, the predetermined optimum coefficient is corrected using a correction value determined for each optical disc apparatus, and the calculation based on the corrected coefficient is performed on the innermost optimum recording power, so that the outermost optimum recording power is obtained. Ask for.

  Hereinafter, the method for obtaining the correction value will be described in order.

  First, processing based on the flowchart shown in FIG. 2 is executed in a specific optical disk apparatus (hereinafter referred to as a reference drive) in which accuracy of functions such as data recording and data reproduction is guaranteed at the time of manufacturing the optical disk apparatus.

  In FIG. 2, the control unit 24 of the reference drive executes OPC at the inner periphery recording speed in the inner periphery test recording area provided on the innermost periphery of the optical disc 10 to obtain the inner periphery optimum recording power Pbi in the reference drive ( S100). Note that the optical disk 10 used here is a so-called standard of an industry standard used when performing performance inspection of a specific disk, for example, an optical disk device, for which stable recording quality is guaranteed in advance in a plurality of models of a plurality of manufacturers. A disk is preferred. Next, in a predetermined data recording area in which actual data is recorded (for example, when the data recording area is divided into a plurality of zones, the data recording area corresponding to the outermost zone), the outer circumference recording is higher in speed than the inner circumference recording speed. OPC is executed at the speed to obtain the optimum outer peripheral recording power Pbo in the reference drive (S102). Next, the control unit 24 obtains the reference ratio coefficient Kbo of the outer peripheral recording speed by dividing the outer peripheral optimal recording power Pbo by the inner peripheral optimal recording power Pbi (S104). That is, the control unit 24 obtains Kbo based on the equation Kbo = Pbo / Pbi.

  In the present embodiment, the reference ratio coefficient Kbo obtained as described above is managed as firmware and registered in advance in a memory (for example, EEPROM) 26 of each manufactured optical disc apparatus.

  Next, a method of obtaining the outer peripheral recording speed correction value ρo for an optical disc apparatus that is a drive other than the reference drive (hereinafter referred to as a target drive) will be described with reference to the flowchart shown in FIG.

  In FIG. 3, the control unit 24 of the target drive executes OPC of the inner peripheral recording speed in the innermost test recording area of the optical disc 10 to obtain the inner peripheral optimum recording power Pti in the target drive (S200). Next, the control unit 24 reads the reference ratio coefficient Kbo of the outer peripheral recording speed registered in the memory 26, and multiplies the inner peripheral optimum recording power Pti by the reference ratio coefficient Kbo, so that the first outer recording speed for the target drive is increased. The optimum recording power Pto1 is obtained (S202). That is, the control unit 24 obtains the first optimum recording power Pto1 based on the expression Pto1 = Kbo × Pti. Thereby, the optimum recording power with respect to the outer peripheral recording speed in the target drive can be obtained. However, when data recording is performed at the outer peripheral recording speed with the first optimum recording power Pto1 obtained here, depending on the optical disk device, the difference in the laser diode wavelength of the optical pickup unit 14, the tilt angle of the optical axis with respect to the disk surface, or the like. The environment of the reference drive is different, the compatibility of the reference ratio coefficient Kbo is not obtained, and the β value may not actually satisfy the reference β value.

  Therefore, in the present embodiment, the control unit 24 further performs the outer peripheral recording speed in a predetermined data recording area (for example, when the data recording area is divided into a plurality of zones, the data recording area corresponding to the zone located at the outermost periphery). The second optimum recording power Pto2 with respect to the outer peripheral recording speed in the target drive is obtained (S204), and the second optimum recording power Pto2 is divided by the first optimum recording power Pto1. A correction value ρo for the outer peripheral recording speed is obtained (S206). That is, the control unit 24 obtains the correction value ρo based on the equation ρo = Pto2 / Pto1, and registers the correction value ρo in the memory 26 in association with the reference ratio coefficient Kbo (S208). In the OPC in step S204, for example, in a predetermined data recording area, the recording power is switched in a plurality of stages around the already determined first optimum recording power Pto1, and each β is measured. And a function indicating the relationship between the recording power such as an approximate line and the β value by a well-known approximation algorithm such as a least square method based on each β value and the recording power corresponding to the target β value based on the function. As a result, a process for obtaining the second optimum recording power Pto2 is executed.

  As described above, in this embodiment, the optical disc apparatus obtains the correction value ρo at the time of shipment adjustment, for example, registers it in the memory 26, corrects the reference ratio coefficient Kbo using the correction value ρo, and then performs outer periphery recording. Find the optimum recording power for speed.

  FIG. 4 is a flowchart showing a procedure for obtaining the optimum recording power Po at the outer peripheral recording speed by the optical disc apparatus according to the present embodiment.

  In FIG. 4, upon receiving a data recording request from the user, the control unit 24 executes OPC at the inner peripheral recording speed in the test recording area provided on the innermost periphery of the optical disc 10 prior to data recording. The optimum recording power Pi for the recording speed is obtained (S300). Next, the control unit 24 reads the reference ratio coefficient Kbo corresponding to the outer peripheral recording speed and the correction value ρo from the memory 26, and multiplies the optimum recording power Pi for the inner peripheral recording speed by the reference ratio coefficient Kbo and the correction value ρo. Thus, the optimum recording power Po for the outer peripheral recording speed is obtained. That is, the control unit 24 obtains Po based on the equation Po = Kbo × ρo × Pi. In this way, after correcting the reference ratio coefficient Kbo using the correction value ρo determined as a unique value for each optical disc apparatus, the optimum recording power Po is obtained, for example, the laser diode wavelength of the optical pickup unit 14 and the disc surface. Thus, the influence of the error due to the difference in the tilt angle of the optical axis with respect to each disk device can be reduced, and the optimum recording power for the high recording speed at the outer periphery of the disk can be obtained more accurately for each optical disk device.

  Further, since the optimum recording power for the high-speed recording speed in the outer peripheral portion can be obtained based on the optimum recording power obtained by OPC in the inner circumference test recording area, the number of executions of OPC can be suppressed, The time required to start data recording can be shortened.

  Furthermore, according to the present embodiment, if a reference ratio coefficient Kb for, for example, one type of DVD-R is obtained in advance by a reference drive, other types of DVDs composed of other dyes having different recording sensitivities to laser light. Since the correction value ρ can be obtained in the same procedure for the -R and the reference ratio coefficient Kb can be corrected, the optimum recording power for the high-speed recording speed in the outer peripheral portion can be obtained with high accuracy for other types of DVD-R. Can do.

  Also, when the optimum recording power at a recording speed different from the outer peripheral recording speed at the time of obtaining the reference ratio coefficient Kb is obtained by using a known approximation algorithm, the reference ratio coefficient Kb is corrected by the correction value ρ. If so, the accuracy of the required optimum recording power can be improved.

  Further, assuming that the ratio between the recording speed and the recording power is approximately approximate to the curve of the theoretical value, the correction value p specific to the optical disk apparatus adjusted by the DVD-R is set to another recording medium (DVD + R, DVD- RW, DVD + RW, etc.) can be used together.

  In the above description, the example of obtaining the optimum recording power Po for one outer peripheral recording speed has been described. However, when different recording speeds are set for each zone as in the Zone-CLV method, for example, the reference ratio coefficient Kb and the correction value ρ are obtained for each set recording speed and stored in the memory 26. The optimum recording power P may be obtained by using the reference ratio coefficient Kb and the correction value ρ for each recording speed. Further, instead of obtaining the reference ratio coefficient Kb and the correction value ρ corresponding to all the set recording speeds, the reference ratio coefficient Kb and the correction value ρ corresponding to several recording speeds are obtained, and the remaining The recording speed may be obtained based on a known approximation algorithm such as a least square method.

  In addition, when the first optimum recording power Pto1 and the second optimum recording power Pto2 are similar, the optimum recording power can be obtained with high accuracy without deliberately obtaining the correction value ρ and correcting the reference ratio coefficient Kb. be able to. Therefore, the controller 24 obtains the similarity between the first optimum recording power Pto1 and the second optimum recording power Pto2 before obtaining the correction value ρ, and corrects the similarity if the similarity satisfies the reference value. The correction value ρ may be obtained only when the value ρ is not obtained and the similarity is lower than the reference value. For example, the control unit 24 obtains a difference between the first optimum recording power Pto1 and the second optimum recording power Pto2 before obtaining the correction value ρ, and only when the difference exceeds a predetermined threshold value. The correction value ρ may be obtained.

It is a principal part block diagram of the optical disk device concerning this embodiment. It is a flowchart which shows the procedure in which a reference | standard drive calculates | requires the reference | standard ratio coefficient Kbo. 5 is a flowchart showing a procedure for an optical disk device to obtain a correction value ρ. 10 is a flowchart illustrating a procedure in which the optical disc apparatus corrects a reference ratio coefficient Kbo based on a correction value ρ.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 Optical disk, 12 Spindle motor, 14 Optical pick-up part, 16 LD drive part, 18 Encoder, 20 RF signal processing part, 22 Decoder, 24 Control part, 26 Memory

Claims (6)

In an optical disc apparatus for recording data by irradiating a data recording area provided on the optical disc with laser light having an optimum recording power according to the recording speed,
A first optimum recording power with respect to a first recording speed determined by the specific optical disk device performing trial recording at a first recording speed in an inner circumference test recording area on the inner circumference side of the data recording area provided on the optical disc; A coefficient determined based on a second optimum recording power with respect to a second recording speed obtained by the specific optical disc device performing trial recording at a second recording speed different from the first recording speed in the data recording area. A memory for storing
A third optimum recording power for the first recording speed is obtained by performing trial recording at the first recording speed in an inner periphery test recording area provided on the optical disc, and the coefficient recorded in the memory and the third optimum recording are obtained. And an optimum recording power determination unit for obtaining a fourth optimum recording power for the second recording speed in the data recording area based on the power,
An optical disc device comprising: The optical disc apparatus according to claim 1,
By performing trial recording at the second recording speed in the data recording area of the optical disc, a fifth optimum recording power for the second recording speed is obtained, and based on the fourth optimum recording power and the fifth optimum recording power, A correction value registration unit that obtains a correction value for correcting the coefficient and registers the correction value in the memory in association with the coefficient;
The optimum recording power determination unit
An optical disc apparatus, wherein the coefficient is corrected based on the correction value, and the fourth optimum recording power is obtained based on the corrected coefficient and the third optimum recording power. The optical disk apparatus according to claim 2, wherein
The correction value registration unit
An optical disc apparatus characterized in that the correction value is obtained and registered in the memory when the similarity between the fourth optimum recording power and the fifth optimum recording power is lower than a predetermined reference value. An optical disk device for recording data at different recording speeds according to the radial position of the optical disk,
Means for setting the first optimum recording power at the recording speed of the test recording area by performing trial writing in the inner periphery side test recording area of the optical disc;
Using the correlation coefficient that defines the relationship between the optimum recording power at the recording speed of the inner circumference side test recording area of the particular optical disk and the optimum recording power at the recording speed of the outer circumference side data recording area in the particular optical disk device. Means for calculating the optimum recording power at the recording speed of the data recording area of the optical disc from the optimum recording power;
An optical disc apparatus comprising: The apparatus of claim 4.
The optical disc apparatus, wherein the correlation coefficient is a ratio of an optimum recording power at a recording speed in the outer circumference side data recording area to an optimum recording power at a recording speed in the inner circumference side test recording area. The apparatus of claim 4, further comprising:
Means for increasing / decreasing the correlation coefficient in the specific optical disc device by trial writing in the data recording area of the optical disc;
An optical disc apparatus comprising:

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