JP2007323730A - Optical disk recording apparatus and its optimum recording power determination method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To alleviate effect of recording sensitivity fluctuation of an optical disk and raise OPC precision in a method of determining optimal recording power in a recording type optical disk. <P>SOLUTION: The optimal recording power is obtained by performing test recording with the same power to a first location where the recording sensitivity is higher than the average sensitivity of the optical disk which is an object of recording and a second location where the record sensitivity is lower than the average sensitivity only by difference of recording sensitivity of this first location and the average sensitivity, and from the average of the recording property values of the locations where the test recording is performed. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an optical disc recording apparatus that records on an optical disc with a laser, and more particularly to an optical disc recording apparatus that performs recording by setting an optimum recording power for the optical disc and an optimum recording power determination method thereof.

  In general, in the method of determining and controlling the optimum recording light emission power (hereinafter referred to as Po: Optimum Write Power) for optical disk recording (hereinafter referred to as OPC: Optimum Power Control), several points near the recording power (hereinafter referred to as Pm) suitable for obtaining Po. Po is calculated by calculating the recording characteristic values (for example, change in reflectance during recording, asymmetry after recording, amplitude, modulation degree, jitter, etc.) obtained by performing test recording with these powers. (This calculation process is hereinafter referred to as Po calculation).

  However, since the exact value of Pm is unknown at the stage before performing OPC, test recording is performed with an expected wide range of recording power, Pm is selected from the obtained recording characteristic values, and the recording characteristic values in the vicinity thereof are selected. It was used to perform the Po operation.

  A schematic diagram of a conventional OPC technique is shown in FIG. Here, in order to simplify the description, an example in which there is a sinusoidal sensitivity variation with a period θt is shown. The number of powers for test recording (hereinafter referred to as N) is set to 6, but various numbers are actually used. P (i) is a test recording power series, and E (i) is a recording characteristic value series obtained by test recording with P (i). In order to make the explanation easy to understand, the power of the recording power series P (i) is assumed to increase as i increases here, but the present invention is not limited to this.

一般にＯＰＣでは、ディスクを回転させながらディスクの連続した特定位置に記録パワーを変えながらテスト記録を行う。図１はθsで示すテスト記録開始位置から記録パワーＰ（０）〜Ｐ（５）でテスト記録を行っている様子を示している。次に、得られた記録特性値Ｅ（ｉ）からＰｏ演算が行われるが、この例ではＰｍとして｛Ｐ（１）＋Ｐ（２）｝／２が選択され、その近傍の記録特性値Ｅ（１）、Ｅ（２）がＰｏ演算のために選ばれた様子を示している。ここで図示したような感度変動があるとＰｏ演算に使われる記録特性値Ｅ（１）、Ｅ（２）は記録感度の高い所での測定値なので、Ｐｏ演算によって得られるＰｏ値は記録感度が高い状態に対応した値となる。

In general, in OPC, test recording is performed while changing the recording power to a specific continuous position on the disk while rotating the disk. FIG. 1 shows a state in which test recording is performed at recording powers P (0) to P (5) from the test recording start position indicated by θs. Next, Po calculation is performed from the obtained recording characteristic value E (i). In this example, {P (1) + P (2)} / 2 is selected as Pm, and the recording characteristic value E ( 1) and E (2) are selected for the Po operation. If there is a sensitivity variation as shown here, the recording characteristic values E (1) and E (2) used for the Po calculation are measured values at a high recording sensitivity. Therefore, the Po value obtained by the Po calculation is the recording sensitivity. Is a value corresponding to a high state.

  When performing test recording, the phase relationship between the sensitivity fluctuation and the test recording start position θs is different every time. This is shown in FIG. When OPC is performed in such a phase relationship, the recording characteristic values E (1) and E (2) are measured values at a place where the recording sensitivity is low, and thus Po obtained is a value corresponding to the state where the recording sensitivity is low. .

  As shown in the examples of FIGS. 1 and 2, the conventional OPC has a problem that the Po value obtained by the phase relationship between the sensitivity fluctuation and the test recording start position fluctuates and the OPC accuracy is lowered.

Up to now, various methods have been proposed as means for compensating for the influence of such sensitivity fluctuations. However, these methods measure the recording characteristics of the area in which test recording is performed in advance and perform compensation calculation (see, for example, Patent Document 1 and Patent Document 2), or adjust the recording characteristics of the area in advance (for example, Patent Document 1). 3). Such a method has a drawback that it is necessary to repeat a series of operations of recording and measurement of various characteristics, and the processing of the entire OPC becomes complicated. Further, there is a problem that a technique that requires recording in an area for test recording as preprocessing cannot be used for an optical disk that cannot be rewritten, such as a CD-R.
JP 2004-253016 A JP 2002-319135 A JP 2000-251254 A

  As described above, the conventional OPC has a problem that the Po value obtained by the phase relationship between the sensitivity variation of the optical disk and the test recording start position varies, and the OPC accuracy is lowered. In addition, in the method of performing the compensation calculation by measuring the recording characteristics of the area where the test recording is performed in advance, or adjusting the recording characteristics of the area in advance, it is necessary to repeat a series of operations of recording and measurement of various characteristics. The entire processing becomes complicated, and the technique that requires recording in the test recording area as preprocessing has a problem that it cannot be used for a non-rewritable disc such as a CD-R.

  In view of such circumstances, the present invention intends to provide an optical disc recording apparatus and its optimum recording power determination method capable of reducing the influence of fluctuations in recording sensitivity of the optical disc and improving the accuracy of recording power control. is there.

  In order to achieve the above object, an optimum recording power determination method for an optical disk recording apparatus according to the present invention includes a first position having a recording sensitivity higher than the average sensitivity of an optical disk to be recorded, and a recording sensitivity at the first position. The test recording is performed with the same power at the second position where the recording sensitivity is lower than the average sensitivity by the difference between the average sensitivity and the optimum recording power is obtained from the average of the recording characteristic values at the test recording position. To do.

  According to the present invention, it is possible to obtain an optimum recording power in which the influence of the recording sensitivity fluctuation of the optical disc is reduced, and it is possible to improve the accuracy of the recording power control. If the accuracy of the recording power control is improved, it is possible to obtain a desired recording performance even with an optical disk having a small performance margin against the recording power error. In addition, since the present invention only needs to perform recording twice with the same recording power, it is more efficient than a conventional method in which the deviation of Po is reduced by simply repeating OPC, and other sensitivity fluctuation compensation. Combination with the method is also easy.

  The recording power referred to in the present invention is, for example, the recording light emission power of a laser in an optical pickup, but the present invention is not limited to this.

  In the present invention, the first position and the second position can be specified based on the recording sensitivity fluctuation period of the optical disc. If the fluctuation period of the sinusoidal recording sensitivity is known, the recording characteristic value in the case of recording with the average sensitivity can be obtained no matter where the test recording is started. In addition, when information related to the period of fluctuation in recording sensitivity of the optical disc is given in advance, the present invention can be effectively applied to an optical disc such as a CD-R that cannot be overwritten.

  As a specific method for specifying the first position and the second position based on the period of fluctuation in recording sensitivity of the optical disk, recording is performed on the optical disk at a constant power, and from the fluctuation of the recording characteristic value, The method for obtaining the period of the recording sensitivity fluctuation, the method for obtaining the period of the recording sensitivity fluctuation of the optical disk based on the error information for servo, the information on the period of the recording sensitivity fluctuation of the optical disk is embedded in the optical disk, and this information There is a method of reproducing and acquiring the period of fluctuation in recording sensitivity of the optical disc.

  The method of recording on an optical disk at a constant power and obtaining the period of fluctuation in recording sensitivity of the optical disk from the fluctuation of the recording characteristic value may be a short length that can cover about a quarter period as long as accuracy can be ensured. There is an advantage that the recording area can be saved.

  In the present invention, the same power may be recorded in the first position and the second position by repeatedly using a fixed-length test recording power sequence. It is only necessary to provide an interval between the recording power sequence and the second test recording power sequence so that the position phases of both are matched. Further, the test recording power sequence may be repeatedly used to adjust the length of the test recording power sequence so that the same power is recorded at the first position and the second position.

  In the present invention, the first position and the second position can also be specified based on a reference position where the recording sensitivity of the optical disc is an average sensitivity. More specific methods include recording on an optical disk at a constant power and obtaining a reference position from fluctuations in the recording characteristic value, obtaining a reference position based on servo error information, There is a method of embedding information on the reference position and reproducing the information to acquire the reference position.

  Also in this case, the same power recording may be performed at the first position and the second position by repeatedly using a fixed-length test recording power sequence. However, at this time, a sequence in which the order of the test recording power sequence in the first round is reversed is used as the test recording power sequence in the second round so that the same power is recorded in the first position and the second position. .

  According to the present invention, in the method for determining the optimum recording power in a recordable optical disc, it is possible to reduce the influence of fluctuations in recording sensitivity of the optical disc and improve the accuracy of recording power control.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 3 is a block diagram showing the configuration of the optical disk recording apparatus according to the embodiment of the present invention. In the figure, reference numeral 1 denotes an optical disk, and 2 denotes a spindle motor that rotates the optical disk 1. An optical pickup 3 includes, for example, a semiconductor laser, its drive circuit, and optical components such as a lens and an actuator. A sled motor 4 moves the optical pickup 3 in the tangential direction of the optical disk 1. A reproduction device 7 reproduces data, position information, synchronization timing, and the like recorded on the optical disc 1 from a signal obtained from the optical pickup 3. 5 controls the spindle motor 2, the sled motor 4, and the actuator of the optical pickup 3 based on various error information monitored by the optical pickup 3 and the synchronization timing obtained from the reproducing device 7, and the number of revolutions of the optical disk 1. This is a servo device that controls the position of the optical pickup 3 and the position, optical axis, tilt, focus, and the like of the laser light output from the optical pickup 3 to a desired state. Reference numeral 6 denotes an APC (Automatic Power Control) device that controls, for example, laser light emission power to a desired value based on information monitored by the optical pickup 3. Reference numeral 8 denotes a recording characteristic measuring apparatus for measuring recording characteristic values such as modulation degree, asymmetry, β value, and jitter from the information of the optical pickup 3. A recording modulator 9 appropriately modulates the light emission power of the laser of the optical pickup 3 based on information to be recorded. Reference numeral 10 denotes a control device for each device, which includes a sequencer, a central processing unit, a memory, and the like.

  When data is reproduced from the optical disk 1, an appropriate light spot is irradiated onto the optical disk 1 from the optical pickup 3, the servo device 5 appropriately rotates the optical disk 1, moves the optical pickup 3 to a desired position, and further an actuator. Etc. are controlled to scan the recording spot on the optical disc 1 with the light spot. In this state, the playback device 7 plays back the data recorded on the optical disc 1.

  When data is recorded on the optical disc 1, the recording / modulating device 9 appropriately modulates the light emission waveform of the optical pickup 3 from the state in which the above-described data is reproduced, and records the data on the optical disc 1. The light emission power information necessary at this time is acquired by performing OPC before this.

  In addition to fluctuations in the characteristics of the recording film, there are apparent fluctuations due to the relative tilt of the recording light caused by the tilt and warpage of the optical disc and the deviation of the light spot from the recording track. is there. Such sensitivity fluctuations depend on the physical position of the optical disk. Therefore, when scanning on the optical disk on which the light spot rotates, the sensitivity fluctuation is observed as a periodic fluctuation depending on the physical positional relationship of the optical disk. For example, a sensitivity fluctuation having a rotation cycle of the optical disc, a shape of a guide groove (Groove) carved in a recording track of the optical disc, a wobble cycle thereof, or a cycle of 1 / integer thereof occurs.

  In many cases, this sensitivity fluctuation can be expressed approximately by a combination of a single or a plurality of sine waves, and the period can be calculated from error information obtained by the servo device or data measured in advance.

  The present invention pays attention to the fact that the sensitivity fluctuation has a sinusoidal periodicity, and at the time of test recording, recording with the same recording power is performed at a first position higher than the average sensitivity of the target optical disc, and the first position. The difference between the recording sensitivity of the position and the average sensitivity is performed at the same power at the second position where the recording sensitivity is lower than the average sensitivity, and Po is obtained from the average of the recording characteristic values at the test recording position, thereby obtaining the sensitivity of the optical disc. This is intended to reduce the influence of fluctuations.

  As a method of specifying the two positions where test recording is performed in order to obtain the average of the recording characteristic values, there is a method of using, for example, the periodicity or symmetry of a sine wave.

  FIG. 4 is a diagram showing a first principle of the optimum recording power determination method of the present invention using the periodicity of a sine wave. Here, in order to simplify the explanation, an example for a single sinusoidal sensitivity variation is shown. Sensitivity fluctuation approximated by a combination of a plurality of sine waves can be handled as a combination of single sine wave-like sensitivity fluctuations.

  In FIG. 4, the vertical axis represents the recording sensitivity of the optical disk, and the horizontal axis represents an angle representing the position in the recording track direction (circumferential direction) in polar coordinates. Here, it is assumed that the recording sensitivity S (θ) at the position θ can be approximately expressed by the following equation.

Ａ、Ｓｖ、θｔはそれぞれ感度変動の振幅、平均、周期である。

A, Sv, and θt are the amplitude, average, and period of sensitivity variation, respectively.

  In the system of the first principle, recording is performed at a position θa at a certain power P and a position θb separated from the position θa by k · θt / 2 (k is an odd number). The two positions may be anywhere as long as the interval is correct.

  Assuming that the recording sensitivities at θa and θb are Sa and Sb, respectively, the relationships of equations (5) and (6) are established from the nature of the sine wave of equation (4).

図４ではｋ＝１として一つの正弦波の中にθａとθｂを配置したが、例えばｋ＝３、またはそれ以上の奇数を用いて、θａとθｂを複数の正弦波に跨って配置しても構わない。

In FIG. 4, θa and θb are arranged in one sine wave with k = 1. However, for example, by using an odd number of k = 3 or more, θa and θb are arranged across a plurality of sine waves. It doesn't matter.

  Here, the recording characteristic value when recording with the light emission power P is expressed as a function Es (S) of sensitivity. Usually, since the change amount of Es (S) due to the sensitivity fluctuation is small, the change of Es (S) can be approximately regarded as a straight line with respect to S. This is shown in FIG. Here, Es (Sa) and Es (Sb) are recording characteristic values recorded at the positions θa and θb on the recording track, and Es (Sv) is a recording characteristic value when recording is performed at the place of the average sensitivity Sv. As the recording characteristic value used for OPC, it is desirable to use the recording characteristic value Es (Sv) at the average sensitivity Sv, but in this method, it can be easily calculated by the following expression derived from Expression (6).

本方式は正弦波状の記録感度の変動周期が分かれば、どの位置からテスト記録を開始しても平均感度で記録した場合の記録特性値が得られるという利点がある。

This method has an advantage that if the sine wave-shaped recording sensitivity fluctuation period is known, the recording characteristic value in the case of recording with average sensitivity can be obtained no matter where the test recording is started.

  On the other hand, there is a method of using the symmetry of the sine wave by grasping the phase of the sensitivity fluctuation. FIG. 6 shows the second principle of the present invention using symmetry. θv is a reference position of the present system where S (θ) = Sv, and θv = θt / 2 in FIG. 6, but it may be 0 or θt. The other symbols in FIG. 5 indicate the same contents as described above.

  In this system, θa and θb are arranged at two points centered on θv and separated from each other by the same distance θg.

  In this way, the relations of the equations (5) and (6) are established from the symmetry of the sine wave, and as a result, the recording characteristic value Es (Sv) when recording with the average sensitivity Sv is obtained from the equation (7).

  This method has an advantage that if the position at which the recording sensitivity fluctuation becomes the average sensitivity is known, the recording characteristic value in the case of recording with the average sensitivity can be obtained regardless of the period of the sensitivity fluctuation.

  As described above, for example, a method using the periodicity and symmetry of a sine wave has been shown as a method for specifying two positions for test recording in order to obtain an average of recording characteristic values. However, the present invention is not limited to this. is not. For example, recording may be performed with a constant power before the test recording, and the test recording may be performed by specifying a location with high sensitivity and a location with low sensitivity based on a change in the recording characteristic value.

  FIG. 7 is a flowchart showing the procedure of the optimum recording power determination method according to the first embodiment of the present invention using the periodicity of the sine wave. FIG. 11 is a diagram relating to test recording when k = 1 in the first embodiment, and FIG. 12 is a diagram relating to test recording when k = 3. Here, Lb is a distance on the recording track of the optical disc recorded with the light emission power P (i) in the test recording (hereinafter referred to as a block length). Lg is a distance (hereinafter referred to as “Gap”) provided to match the position phases of the P (i) series of the first round and the P (i) series of the second round. 11 and 12, the number N of P (i) sequences is 6, but the present invention is not limited to this.

  In the first embodiment, the sensitivity fluctuation period θt of each optical disk is obtained in advance by measurement or the like and stored as a database in the memory of the optical disk recording apparatus.

  The procedure of the optimum recording power determination method according to the first embodiment will be described below.

  (Step S101) First, the control device 10 acquires the sensitivity cycle θt of the target optical disk from the database stored in its own memory.

  (Step S102) The control device 10 determines k that satisfies the following condition from the acquired sensitivity cycle θt, block length Lb, and P (i) number of sequences N.

      Condition 1: Positive odd number

ｋとしては大きい値を使っても構わないが、テスト記録に使うトラック長が長くなるので通常は上の条件を満たす一番小さい値がよい。

A large value may be used as k. However, since the track length used for test recording becomes long, the smallest value that satisfies the above condition is usually preferable.

  (Step S103) Next, the control device 10 calculates a gap length Lg necessary for matching the position phases of the first and second test recordings by the following equation.

（ステップＳ１０４）制御装置１０は、これまでに得た条件をもとに例として図１１、図１２に示したようにテスト記録を行う。Ｇａｐの部分は適切な発光パワーで記録しても、記録しなくても構わない。また１巡目の記録と２巡目の記録は一連で行っても２回に分けて記録してもよい。

(Step S104) The control apparatus 10 performs test recording as shown in FIGS. 11 and 12 as an example based on the conditions obtained so far. The gap portion may be recorded with an appropriate light emission power or may not be recorded. Further, the first and second rounds of recording may be performed in series or in two.

  (Step S105) The control device 10 measures the recording characteristic values Ea (i) and Eb (i) from the test recording location.

  (Step S106) The control device 10 calculates the recording characteristic value E (i) at the average recording sensitivity using the equation (7).

  (Step S107) The control device 10 performs a calculation to obtain the optimum recording light emission power Po. Various methods have been proposed for this calculation method, but the present invention is not limited to a specific method.

  (Step S108) As described above, the optimum recording light emission power Po in which the influence of the recording sensitivity fluctuation is reduced is obtained.

  As described above, there are various factors of the recording sensitivity fluctuation. For example, the relative light spot tilt, the deviation from the recording track (hereinafter referred to as detrack), and the focus deviation (hereinafter referred to as defocus) are the period fluctuations. However, if it is reduced, the accuracy of OPC can be improved. Such error information can be acquired from the servo device.

  FIG. 8 is a flowchart showing the procedure of the optimum recording power determination method according to the second embodiment of the present invention, using the recording sensitivity fluctuation information acquired from this servo device.

  (Step S201) The control device 10 measures fluctuations such as tilt, detrack, and defocus from the servo device 5 based on the error information. If the measurement is performed for a long time, the measurement accuracy of θt is improved. However, if the accuracy can be ensured, for example, a short period that can cover a quarter cycle may be used.

  (Step S202) The control device 10 calculates the recording sensitivity fluctuation period θt from the information obtained in step S201. The following processing (step S102) to (step S108) is the same as that of the first embodiment.

  In many cases, fluctuations in sensitivity due to characteristics of the recording film of the optical disk and characteristics of the reflective film, the cover film, etc. can be grasped in the process of manufacturing the optical disk. In general recordable optical discs, address information is embedded in the optical disc by processing such as wobble modulation of the Groove structure or providing pits in order to indicate a physical position (hereinafter referred to as an address). A method of embedding information is also effective.

  FIG. 9 is a flowchart showing the procedure of the optimum recording power determination method according to the third embodiment of the present invention using the sensitivity variation period information embedded in the optical disc.

  (Step S301) The control device 10 acquires the recording sensitivity period θt from the information embedded in the optical disc. The following processing (step S102) to (step S108) is the same as that of the first embodiment.

  It is also possible to record directly on the optical disk and obtain the sensitivity fluctuation period from the fluctuation of the recording characteristic value. If the accuracy can be ensured, the length may be a short length that can cover about ¼ period, and there is an advantage that the test recording area can be saved as compared with other inventions. Since the present invention only needs to know the period, it can be used for an optical disc such as a CD-R that cannot be overwritten. For the test recording, another vacant place is used for an optical disk that cannot be overwritten, but the same place may be used for an optical disk that can be overwritten.

  FIG. 10 is a flowchart showing the procedure of the optimum recording power determination method according to the fourth embodiment of the present invention, which utilizes the fact that recording is performed on an optical disc at a constant power to obtain the fluctuation cycle of the recording characteristic value.

  (Step S401) First, recording is performed on the optical disc at a constant recording light emission power P.

  (Step S402) The control device 10 measures the recording characteristic value of the part recorded in step S401, and acquires the recording sensitivity fluctuation period θt. The following processing (step S102) to (step S108) is the same as that of the first embodiment.

  In the first to fourth embodiments described above, the position phase of the P (i) sequence in the first and second rounds is adjusted by providing a gap, but the phase is adjusted by changing the recording block length. May be. That is, the block length is adjusted so that the test recording lengths of the first and second rounds are θt / 2, respectively. However, generally, if the recording block length is short, the accuracy of the recording characteristic value deteriorates. In this case, the value of k is adjusted appropriately.

  FIG. 13 shows the procedure of the optimum recording power determination method according to the fifth embodiment of the present invention, in which the recording block length is changed and the phase phases of the first and second P (i) sequences are matched. It is a flowchart to show. FIG. 17 is a diagram relating to test recording when k = 1 in the fifth embodiment, and FIG. 18 is a diagram relating to test recording when k = 3.

  (Step S501) First, the control device 10 acquires the sensitivity cycle θt of the target optical disk from the database stored in its own memory.

  (Step S502) Next, the control device 10 determines k that satisfies the following condition from the acquired sensitivity period θt, block length Lb, and P (i) number of sequences N.

但しｋは正の奇数。

Where k is a positive odd number.

  The value of k may be 1, but if Lb is too short for the desired recording characteristic accuracy, an appropriately large positive odd number is selected.

  (Step S503) Next, the control device 10 performs test recording as shown in FIGS. 17 and 18, for example, from the information obtained so far. At this time, the gap as used in the first embodiment is not necessary. The following processes (step S105) to (step S108) are the same as those in the first embodiment.

  As a method of acquiring the cycle θt in step S501, as in the second to fourth embodiments, for example, error information from the servo device 5, a method of embedding information in the optical disc, and a constant recording light emission power P There are recording methods. The optimum recording power determination method of these embodiments is shown in FIGS. 14, 15, and 16 as the sixth embodiment, the seventh embodiment, and the eighth embodiment, respectively. The procedure after acquiring the period θt is the same as that in the fifth embodiment.

  FIG. 19 is a flowchart showing the procedure of the optimum recording power determination method according to the ninth embodiment of the present invention using the sensitivity fluctuation symmetry. FIG. 22 is a diagram showing a state of test recording according to the ninth embodiment. Here, θv is a reference position where the recording sensitivity S (θ) becomes the average sensitivity Sv in the region where test recording is to be performed.

  (Step S901) The control device 10 measures fluctuations such as tilt, detrack, and defocus from the servo device 5 based on the error information. If the measurement is performed for a long time, the measurement accuracy of θv is improved. However, if the accuracy is obtained, θv may be calculated from a measurement that is short enough to cover, for example, a quarter period.

  (Step S902) The control device 10 estimates the recording sensitivity variation from the information obtained in Step S901, and acquires the reference position θv at which this becomes the average recording sensitivity Sv. As long as S (θ) = Sv, it may be 0, θt / 2, or θt.

  (Step S903) The control device 10 calculates the test recording start position θs by the following equation.

ここでＬｂは記録ブロック長、ＮはＰ（ｉ）系列数である。

Here, Lb is the recording block length, and N is the number of P (i) sequences.

  (Step S904) The control device 10 performs test recording so that the order of the P (i) series in the first and second rounds is line-symmetric with respect to the reference position θv. That is, as shown in FIG. 22, the recording light emission power is arranged so that the P (i) sequence of the second round is reverse to the order of the first round.

  The following processes (step S105) to (step S108) are the same as those in the first embodiment.

  As a method for acquiring the reference position θv in step S901 and step S902, as in the third and fourth embodiments, for example, a method of embedding information in an optical disc or a method of recording with a constant recording light emission power P Etc. These embodiments are shown as a tenth embodiment and an eleventh embodiment in FIGS. 20 and 21, respectively.

  As for the tenth embodiment, the relationship between the recording position information (hereinafter referred to as address information) of the optical disk and θv may be preliminarily made into a database, and θv may be calculated from the address information during OPC.

  As in the fourth embodiment, the eleventh embodiment has an advantage that θv can be obtained from recording of about ¼ period and can be applied to an optical disc that cannot be overwritten. The procedure after acquiring the reference position θv is the same as that in the ninth embodiment.

  It should be noted that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the present invention.

It is a figure for demonstrating the conventional OPC method. It is a figure for demonstrating the subject of the conventional OPC method. It is a block diagram which shows the structure of the optical disk recording device concerning this invention. It is a figure which shows the 1st principle of the optimal recording power determination method concerning this invention using the periodicity of a sine wave. It is a figure which shows the relationship between the recording sensitivity and recording characteristic value of a 1st principle. It is a figure which shows the 2nd principle of the optimal recording power determination method concerning this invention using the symmetry of a sine wave. It is a flowchart which shows the procedure of the optimal recording power determination method concerning the 1st Embodiment of this invention. It is a flowchart which shows the procedure of the optimal recording power determination method concerning the 2nd Embodiment of this invention. It is a flowchart which shows the procedure of the optimal recording power determination method concerning the 3rd Embodiment of this invention. It is a flowchart which shows the procedure of the optimal recording power determination method concerning the 4th Embodiment of this invention. It is a figure regarding the test recording in case of k = 1 in 1st Embodiment. It is a figure regarding the test recording in case of k = 3 in 1st Embodiment. It is a flowchart which shows the procedure of the optimal recording power determination method concerning the 5th Embodiment of this invention. It is a flowchart which shows the procedure of the optimal recording power determination method concerning the 6th Embodiment of this invention. It is a flowchart which shows the procedure of the optimal recording power determination method concerning the 7th Embodiment of this invention. It is a flowchart which shows the procedure of the optimal recording power determination method concerning the 8th Embodiment of this invention. It is a figure regarding the test recording in case of k = 1 in 5th Embodiment. It is a figure regarding the test recording in the case of k = 3 in 5th Embodiment. It is a flowchart which shows the procedure of the optimal recording power determination method concerning the 9th Embodiment of this invention. It is a flowchart which shows the procedure of the optimal recording power determination method concerning the 10th Embodiment of this invention. It is a flowchart which shows the procedure of the optimal recording power determination method concerning the 11th Embodiment of this invention. It is a figure which shows the mode of the test recording of 9th Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Optical disk 2 Spindle motor 3 Optical pick-up 4 Thread motor 5 Servo apparatus 6 APC apparatus 7 Playback apparatus 8 Recording characteristic measuring apparatus 9 Recording modulation apparatus 10 Control apparatus

Claims (13)

  A first position where the recording sensitivity is higher than the average sensitivity of the optical disc to be recorded, and a second position where the recording sensitivity is lower than the average sensitivity by the difference between the recording sensitivity at the first position and the average sensitivity. A method for determining the optimum recording power of an optical disk recording apparatus, wherein test recording is performed with the same power, and the optimum recording power is obtained from an average of the recording characteristic values at the test recording positions.   2. The method for determining the optimum recording power of an optical disk recording apparatus according to claim 1, wherein the first position and the second position are specified based on a period of a change in recording sensitivity of the optical disk.   3. The method for determining the optimum recording power of an optical disc recording apparatus according to claim 2, wherein recording is performed on the optical disc at a constant power, and a period of fluctuation in recording sensitivity of the optical disc is obtained from a change in recording characteristic value.   3. The method for determining the optimum recording power of an optical disk recording apparatus according to claim 2, wherein a period of a change in recording sensitivity of the optical disk is obtained based on servo error information.   3. The optical disk recording according to claim 2, wherein information on a period of fluctuation in recording sensitivity of the optical disk is embedded in the optical disk, and this information is reproduced to obtain a period of fluctuation in recording sensitivity of the optical disk. A method for determining the optimum recording power of the apparatus.   The test recording power sequence in the first round and the test recording in the second round are performed so that the same power is recorded at the first position and the second position by repeatedly using the fixed-length test recording power series. 3. The method for determining the optimum recording power of an optical disk recording apparatus according to claim 2, wherein an interval is provided between the power series.   The length of the test recording power sequence is adjusted so that the same power is recorded at the first position and the second position by repeatedly using the test recording power sequence. An optimum recording power determination method for the optical disk recording apparatus described in 1.   2. The optimum recording power determination of the optical disk recording apparatus according to claim 1, wherein the first position and the second position are specified based on a reference position where the recording sensitivity of the optical disk is an average sensitivity. Method.   9. The method for determining the optimum recording power of an optical disk recording apparatus according to claim 8, wherein recording is performed on the optical disk at a constant power, and the reference position is obtained from fluctuations in recording characteristic values.   9. The method for determining the optimum recording power of an optical disk recording apparatus according to claim 8, wherein the reference position is obtained based on error information for servo.   9. The optimum recording of an optical disc recording apparatus according to claim 8, wherein information relating to the reference position of the optical disc is embedded in the optical disc, and the information is reproduced to obtain the reference position of the optical disc. Power determination method.   By repeatedly using a fixed-length test recording power sequence, a sequence in which the order of the test recording power sequence in the first round is reversed so that the same power is recorded at the first position and the second position. 9. The method for determining the optimum recording power of an optical disc recording apparatus according to claim 8, wherein the optimum recording power is used as the test recording power sequence in the second round. With an optical pickup that can change the recording power,
A recording characteristic measuring unit for measuring recording characteristics from information of the optical pickup;
A first position where the recording sensitivity is higher than the average sensitivity of the optical disc to be recorded, and a second position where the recording sensitivity is lower than the average sensitivity by the difference between the recording sensitivity at the first position and the average sensitivity. A control unit that controls to perform test recording with the same light emission power, and obtains the optimum recording power of the optical pickup from the average of the recording characteristic values measured by the recording characteristic measurement unit at the test recording position. An optical disc recording apparatus comprising:

Images