JP2010267381A - Optical disk recording device and optimal recording power determination method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve accuracy of recording power control by reducing the influence of uneven sensitivity of an optical disk. <P>SOLUTION: Information on the cycle of uneven sensitivity of an optical disk is obtained. On the basis of the obtained information on the cycle, a first start position of test recording and a second start position separated from the first start position by θt/2×k (k is an odd number) are calculated, θt indicating a length of the cycle. Test recording is performed on the optical disk by using a sequence of recording powers in which recording powers adjacent to each other in order of magnitude are allocated to the test recording from the first start position and the test recording from the second start position, recording characteristic values at positions where the test recording has been performed are measured, and optimal recording power is calculated based on the measured recording characteristic values. <P>COPYRIGHT: (C)2011,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.

  In OPC, an optical disk is rotated and test recording is performed on the continuous recording track. The test recording is performed while changing the magnitude of the recording power. Conventionally, the test recording is performed while changing the order from the lower power to the higher power or vice versa. For this reason, there is a drawback that the magnitude of the recording power depends on the position of the optical disk.

  A schematic diagram of a conventional OPC technique is shown in FIG. Arc-shaped arrows arranged on substantially concentric circles of the optical disk 1 indicate a state where test recording is performed on a recording track engraved on the optical disk 1 in a spiral shape. The numbers on the inner circumference side indicate the positions on the optical disc 1. P (i) is a recording power, and each section indicated by a corresponding arc-shaped arrow is test-recorded with this power. In this figure, the power number (N) of the recording power sequence is set to 8 to simplify the explanation, but various numbers are actually used. For the sake of simplification, the recording power P (i) is assumed to increase as i increases.

図２はＯＰＣで得られるディスク位置と記録パワーおよび記録特性値との関係を示す図である。ここで、Ｅ（ｉ）は記録パワーＰ（ｉ）でテスト記録した時の記録特性値である。前述のようにＯＰＣではＰｏを得るのに適したパワーＰｍを選択し、その近傍の数点を選んでＰｏ演算を行う。図２の例ではＰｍとしてＰ（３）が選択され、その近傍の記録パワーＰ（２）、Ｐ（３）、Ｐ（４）とその記録特性値Ｅ（２）、Ｅ（３）、Ｅ（４）が選ばれた様子を示している。

FIG. 2 is a diagram showing the relationship between the disk position obtained by OPC, the recording power, and the recording characteristic value. Here, E (i) is a recording characteristic value when test recording is performed with the recording power P (i). As described above, in OPC, a power Pm suitable for obtaining Po is selected, and several points in the vicinity thereof are selected to perform Po calculation. In the example of FIG. 2, P (3) is selected as Pm, and the recording powers P (2), P (3), P (4) in the vicinity thereof and their recording characteristic values E (2), E (3), E (4) shows a state of being selected.

  In addition to the non-uniform characteristics of the recording film itself, the non-uniform characteristics of the recording film itself, the non-uniform characteristics of the cover film and the reflective film, and dirt due to fingerprints can be cited as factors. Apparent unevenness caused by a relative position with respect to the optical lens, an angle shift, or the like due to an attachment error is also included.

  Many of these irregularities depend on the position on the optical disk. For this reason, in the test recording in which the conventional recording power is simply changed from the larger one to the smaller one or vice versa, the area to be recorded with the power in the vicinity of Pm is also close, so the effect is affected by the combination with the position of the sensitivity unevenness. There has been a problem that the number of measurement points to be received fluctuates greatly.

  FIG. 3 is a diagram showing an example of the sensitivity unevenness distribution of the optical disc, and FIG. 4 is a diagram showing the relationship between the disc position, the recording power and the recording characteristic value obtained by OPC for the optical disc having the sensitivity unevenness distribution shown in FIG. is there. In FIG. 3, reference numeral 11 denotes a region where sensitivity unevenness exists. In such a case, all of the recording characteristic values E (2), E (3), and E (4) used for the Po calculation are affected by the sensitivity unevenness, and the accuracy of Po calculated using this value. Is significantly reduced.

  Up to now, various methods have been proposed as means for compensating for the influence of such sensitivity unevenness. 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.

JP 2004-253016 A JP 2002-319135 A JP 2000-251254 A

  As described above, in the conventional OPC, since the test recording is performed using the recording power sequence in which the magnitudes of the recording power are arranged in a permutation, the calculation accuracy of Po is deteriorated due to the influence of the sensitivity unevenness. was there. 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. There was a problem that the entire processing became complicated.

  In view of the above, the present invention intends to provide an optical disc recording apparatus and an optimum recording power determination method thereof that can improve the accuracy of recording power control by reducing the influence of uneven sensitivity of the optical disc. .

  In order to achieve the above object, the optimum recording power determination method of the optical disc recording apparatus of the present invention arranges the recording power series arranged in order of magnitude so that the recording powers adjacent in magnitude are discontinuous. A test recording step for performing test recording on the optical disk using the changed recording power sequence, a step for measuring the recording characteristic value at the position where the test recording was performed, and an optimum recording power based on the measured recording characteristic value. Calculating.

  According to this invention, the dependency of the recording characteristic value on the disk position is reduced, and it is possible to prevent a decrease in the accuracy of the recording power control due to the sensitivity unevenness of the optical disk.

  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.

  The present invention includes a step of creating a recording power sequence rearranged so that adjacent recording powers are discontinuous using random numbers from a recording power sequence arranged in order of size. There may be. In this case, if adjacent recording powers are accidentally arranged, in order to eliminate this, one may be replaced with another recording power or the order may be changed again.

  Further, in the test recording step, the recording power sequence arranged in order of size is recorded in such a manner that the recording powers adjacent to each other become discontinuous while taking into consideration the periodicity of sensitivity unevenness of the optical disc. You may make it test-record on an optical disk using a power series.

  Since the sensitivity unevenness of the optical disc depends on the rotation period of the optical disc and the like, by determining the arrangement of the recording power series in consideration of the periodicity of the sensitivity unevenness of the optical disc as described above, the sensitivity unevenness of the optical disc The influence can be further reduced, and the accuracy of recording power control can be further increased.

  As a method of performing test recording by rearranging the recording powers adjacent to each other in a discontinuous manner while taking into consideration the periodicity of the sensitivity unevenness of the optical disc, information on the recording sensitivity cycle of the optical disc is obtained and obtained. The first start position and the next second start position of the test recording are calculated on the basis of the information related to the cycle, and the adjacent recording powers in the order of the magnitude are compared with the test recording from the first start position and the second start position. There is a method of performing test recording on an optical disk using recording power sequences respectively allocated to test recording from the start position of No. 2. The sequence of the recording power series used for test recording from each start position may be further replaced using a random number.

  Further, the recording sensitivity period of the optical disc may be calculated, and the first start position and the next second start position of the test recording may be calculated based on the calculated period.

  Furthermore, in the test recording step, recording power sequences arranged in order of size are recorded with adjacent recording powers in consideration of the difference in recording sensitivity between the inner track and the outer track of the optical disc. Test recording may be performed on the optical disc using a recording power sequence rearranged so as to be discontinuous.

  That is, the optical disc may have a difference in recording sensitivity between the inner track and the outer track. In such a case, the recording power sequence is rearranged so that the recording powers adjacent to each other are discontinuous while considering the difference in recording sensitivity between the inner track and the outer track of the optical disc. It is effective to perform test recording using.

  As a specific method for performing test recording by rearranging the recording powers adjacent to each other in a discontinuous manner, taking into consideration the difference in recording sensitivity between the inner and outer tracks of the optical disc There is a method of performing test recording using a recording power sequence in which recording powers adjacent in order of size are respectively assigned to an inner track and an outer track.

  Further, the arrangement of the recording power series used for the test recording on the inner and outer peripheral sides of the optical disc may be switched using a random number.

  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 sensitivity unevenness of the optical disc and improve the accuracy of recording power control.

It is a figure for demonstrating the conventional OPC method. It is a figure which shows the relationship between the disk position obtained by OPC, recording power, and a recording characteristic value. It is a figure which shows the example of distribution of the nonuniformity of the recording sensitivity of an optical disk. FIG. 4 is a diagram illustrating a relationship between a disk position obtained by OPC, a recording power, and a recording characteristic value with respect to the optical disk having the sensitivity unevenness distribution illustrated in FIG. 3. It is a block diagram which shows the structure of the optical disk recording device concerning embodiment of this invention. It is a figure which shows the relationship between the disk position in the optimal recording power determination method of this invention, recording power, and a recording characteristic value. 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 figure which shows the relationship between the disk position in the optimal recording power determination method of 3rd Embodiment, recording power, and a recording characteristic value. 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 which shows the relationship between the disk position in the optimal recording power determination method of 4th Embodiment, recording power, and a recording characteristic value. 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 figure which shows the order of the recording power of the inner peripheral side of an optical disk, and the outer peripheral side regarding the optimal recording power determination method concerning 6th Embodiment. 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 figure which shows the order of the recording power of the inner peripheral side of an optical disk, and the outer peripheral side regarding the optimal recording power determination method concerning 7th Embodiment. It is a flowchart which shows the procedure of the optimal recording power determination method concerning the 8th Embodiment of this invention.

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

  FIG. 5 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 disc 1, an appropriate light spot is irradiated onto the optical disc 1 from the optical pickup 3, the servo device 5 appropriately rotates the optical disc 1, moves the optical pickup 3 to a desired position, and 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.

  The present invention pays attention to the fact that many sensitivity irregularities depend on the disk position, and instead of performing test recording with a recording power sequence in which the recording powers are arranged in order of magnitude, the order is changed by an appropriate method, By performing test recording with the recording power series rearranged so that the recording powers of adjacent sizes become discontinuous, the dependency on the disk position is eliminated and the influence of sensitivity unevenness is reduced.

  FIG. 6 shows the principle of the present invention. This is an example in which the present invention is applied in the case where there is uneven sensitivity as shown in FIG. 4, and the order of the recording power P (i) with respect to the disk position is such that the recording powers adjacent in magnitude are discontinuous. Has been replaced. When test recording is performed with such a recording power sequence, the dependency of the recording characteristic value E (i) on the disk position is reduced. That is, in the conventional method shown in FIG. 4, all the recording characteristic values E (2), E (3), and E (4) used for the Po calculation are affected by the sensitivity unevenness. In the example of FIG. 6 based, only E (2) is affected by the sensitivity unevenness. Therefore, the accuracy of the obtained Po is greatly improved.

  In order to make the explanation easy to understand, an example in which sensitivity unevenness has locally occurred has been shown. However, in practice, sensitivity unevenness is often distributed over a wide range on the optical disc 1, and Po obtained by OPC is preferably a value at an average sensitivity. Since the present invention has the effect of discretely dispersing the recording characteristic values used for the Po calculation with respect to the disk position, there is an advantage that Po close to the average value can be obtained compared to the conventional method.

  Hereinafter, embodiments of the present invention will be described more specifically.

  FIG. 7 is a flowchart showing the procedure of the optimum recording power determination method according to the first embodiment of the present invention. In the present embodiment, a system is employed in which the order of the recording power P (i) in the recording power sequence is replaced with a random number.

  (Step S101) First, the control device 10 uses a random number from a recording power sequence given in advance to change the order of the recording power P (i) so that adjacent recording powers are discontinuous. An exchanged recording power sequence is created and stored in a memory in the control device 10. The pre-given recording power sequence is a sequence in which the recording powers are arranged in order of magnitude. If the adjacent recording powers are accidentally lined up by the replacement process using random numbers, one of them is replaced with another recording power or the order is changed again in order to eliminate this.

  (Step S <b> 102) The control device 10 performs control so as to perform test recording on the optical disc 1 using the recording power sequence stored in the memory.

  (Step S <b> 103) Next, the control device 10 measures the recording characteristic value at the position where the test recording is performed by the recording characteristic measuring device 8.

  (Step S <b> 104) Next, the control device 10 executes Po calculation using the recording characteristic value measured by the recording characteristic measuring device 8.

  (Step S <b> 105) Po with reduced influence of sensitivity unevenness is obtained by the procedure so far.

  Since the gist of the present invention is to reduce the dependency of the order of the recording power used for test recording and the sensitivity unevenness of the optical disc, the recording powers adjacent in magnitude are discontinuous using random numbers in advance. The recording power sequence information rearranged so as to be stored in the memory may be stored in the memory, and the OPC may perform test recording using the recording power sequence every time. In this way, there is an advantage that an optimum arrangement can be realized each time that a certain recording power P (i) and a recording power P (h) in the vicinity thereof are uniformly distributed on the optical disc with a certain distance.

  FIG. 8 is a flowchart showing the procedure of the optimum recording power determination method according to the second embodiment of the present invention that employs this method.

  (Step S201) First, the control device 10 executes test recording using information of recording power sequences stored in advance in memory and rearranged so that adjacent recording powers are discontinuous. Take control. One recording power sequence may be used, but a plurality of recording power sequences having different recording power arrangements may be stored in the memory, and an appropriate recording power sequence may be selected from among them to perform test recording. Subsequent operations are the same as steps S103 to S105 of the first embodiment.

  Sensitivity unevenness that affects OPC includes apparent sensitivity unevenness caused by warpage of the optical disc, relative position with the optical lens due to mounting errors, and angular misalignment. This kind of sensitivity unevenness is observed as a fluctuation in the sensitivity of the rotation period of the optical disk or a period of an integral number when the optical disk is rotated and scanned on the recording track. If the periodicity of the sensitivity is also taken into consideration when the order of the recording power is changed, the Po accuracy can be further increased.

  FIG. 9 is a flowchart showing the procedure of the optimum recording power determination method according to the third embodiment of the present invention that employs this method. FIG. 10 is a diagram showing the relationship between the disk position, the recording power P (i), and the recording characteristic value E (i) when this method is adopted.

  Here, to simplify the explanation, it is assumed that the number of data N of the recording power series is 10, and the sensitivity fluctuation is a sine wave with a period θt. In FIG. 10, {P (5) + P (6)} / 2 is selected as Pm, and the recording characteristic values used for the Po calculation are E (4), E (5), E (6), and E (7). Indicates the state.

  Due to the nature of the sine wave, the average of a certain position θa and the sensitivity at a position θb away from it by θt / 2 × k (k is an odd number) is almost equal to the average of the entire sensitivity. Therefore, by arranging the recording power P (i) and the recording power P (i + 1) that are adjacent in order of magnitude at the position θa and the position θb, respectively, a value of Po closer to the average sensitivity can be obtained.

  In the example of FIG. 10, the test recording A is performed from the position θa, and the next test recording B is performed from the position θb separated from the position θa by θt / 2. In the test record A, test recording is performed with a recording power of P (i) where i is an even number, and in the test record B, P (i + 1) obtained by adding 1 to i in the corresponding test record A, that is, i is an odd number. Test recording is performed with recording power. By performing test recording in this manner, the distance between the recording position at the recording power P (i) and the recording position at the recording power P (i + 1) is always θt / 2.

  The procedure of the optimum recording power determination method according to the third embodiment using this property will be described below with reference to FIG.

  (Step S301) Since information such as the rotation speed of the optical disk and the inclination from the optical axis is obtained from the servo device 5, the control device 10 observes this and calculates the recording sensitivity period θt. Here, θt may be measured by measuring several cycles. However, if sufficient accuracy is obtained, it may be calculated from an observation result of about ¼ cycle.

  (Step S302) Next, the control device 10 calculates the next start position θb from the test recording start position θa by the following equation.

ここで、テスト記録に使う記録トラック長の面ではｋは小さい方が効率的であるから、値として１を用いるのが望ましい。しかし位置θａから始まるテスト記録が位置θｂに重なってしまう場合は適切に大きな値でもかまわない。

Here, in terms of the recording track length used for test recording, it is more efficient that k is smaller, so it is desirable to use 1 as the value. However, if the test record starting from the position θa overlaps with the position θb, an appropriately large value may be used.

  (Step S303) Next, the control device 10 performs control so that test recording is performed with the recording power P (i) where i is an even number from the position θa. The following formula is applied to the order of the recording power in the recording power sequence.

（ステップＳ３０４）次に、制御装置１０は、位置θｂからｉが奇数のＰ（ｉ）でテスト記録を行うように制御を行う。記録パワー系列における記録パワーの順番は次式を適用する。

(Step S304) Next, the control device 10 performs control so that test recording is performed at P (i) where i is an odd number from the position θb. The following formula is applied to the order of the recording power in the recording power sequence.

なお、ステップＳ３０３とステップＳ３０４は一連の記録動作であってかまわない。

Note that step S303 and step S304 may be a series of recording operations.

  Subsequent operations are the same as steps S103 to S105 of the first embodiment.

  In the third embodiment, the recording power P (i) recorded by test recording from the position θa and the position θb is arranged in the order of the magnitudes. However, as in the first embodiment, this is replaced by a random number. It doesn't matter.

  FIG. 11 is a flowchart showing the procedure of an optimum recording power determination method according to the fourth embodiment of the present invention that employs this method. FIG. 12 is a diagram showing the relationship between the disk position, the recording power P (i), and the recording characteristic value E (i) when this method is adopted.

  (Step S401) Since information such as the rotational speed of the optical disk and the inclination from the optical axis is obtained from the servo device 5, the control device 10 observes this and calculates the recording sensitivity period θt. Here, θt may be measured by measuring several cycles. However, if sufficient accuracy is obtained, it may be calculated from an observation result of about ¼ cycle.

  (Step S402) The control device 10 calculates the next start position θb from the start position θa of the test recording according to the equation (3).

  Here, in terms of the recording track length used for test recording, it is more efficient that k is smaller, so it is desirable to use 1 as the value. However, if the test record starting from the position θa overlaps with the position θb, an appropriately large value may be used.

  (Step S403) The control device 10 creates an array Mj having different elements of 0, 1, 2,..., N / 2-1 and changes the order of the elements.

（ｊ＝０，１，２，…，Ｎ／２−１）
（ステップＳ４０４）次に、制御装置１０は、位置θａからテスト記録を実行するように制御を行う。このとき用いられる記録パワー系列における記録パワーＰ（ｉ）の順番は次式を適用する。

(J = 0, 1, 2,..., N / 2-1)
(Step S404) Next, the control device 10 performs control so as to execute test recording from the position θa. The following formula is applied to the order of the recording power P (i) in the recording power sequence used at this time.

（ステップＳ４０５）次に、制御装置１０は、位置θｂからテスト記録を実行するように制御を行う。このとき用いられる記録パワー系列における記録パワーＰ（ｉ）の順番は次式を適用する。

(Step S405) Next, the control device 10 performs control to execute test recording from the position θb. The following formula is applied to the order of the recording power P (i) in the recording power sequence used at this time.

以降の動作は第１の実施形態のステップＳ１０３〜Ｓ１０５と同じである。

Subsequent operations are the same as steps S103 to S105 of the first embodiment.

  In the present invention, since the effect can be obtained even with the approximate period information, the sensitivity period θt may be calculated in advance from the shape and characteristics of the optical disc, and the order of the recording power in consideration of this may be determined. For example, as shown in FIG. 12, the order of the recording powers rearranged so that the adjacent recording powers are discontinuous is stored in advance in the memory of the control device 10, and the test is performed in this order every time in the OPC. This is a recording method. This method has an advantage that the order of the recording power can be always optimized as in the second embodiment.

  FIG. 13 is a flowchart showing the procedure of the optimum recording power determination method according to the fifth embodiment of the present invention using the above method.

  (Step S501) First, the control device 10 calls information on the sensitivity cycle θt of the optical disc assumed in advance from the memory.

  (Step S502) Next, the control device 10 calculates the next position θb from the equation (3), where θa is the position where test recording is first started.

  (Step S503) Next, the control device 10 calls the order of the recording power for test recording from the position θa from the memory, and executes the test recording A from the position θa. Here, the order of the recording power may be one, but several kinds may be stored in the memory, and an appropriate order may be selected from them.

  (Step S504) Next, the control device 10 calls the order of the recording power for test recording from the position θb, and executes the test recording B from the position θb. In this case as well, the order of the recording power may be stored in several types of memories, and an appropriate order may be selected from them.

  Subsequent operations are the same as steps S103 to S105 of the first embodiment.

  For convenience of explanation, steps S501, S502, S503, and S504 have been described separately. However, in practice, these procedures may be combined into a series of test records.

  An optical disc has a difference in recording sensitivity between an inner track and an outer track. In such a case, the recording power sequence is rearranged so that the recording powers adjacent to each other become discontinuous while considering the difference in recording sensitivity between the inner and outer tracks of the optical disc 1. It is effective to perform test recording using.

  FIG. 14 is a flowchart showing the procedure of an optimum recording power determination method according to the sixth embodiment of the present invention that employs the above-described method. FIG. 15 is a diagram showing the order of the recording power P (i) on the inner and outer peripheral sides of the optical disc. As shown in FIG. 15, in the present embodiment, test recording is performed at a recording power P (i) where i is an even number on the inner circumference side of the optical disc, and a test is performed at a recording power P (i) where i is an odd number on the outer circumference side. Make a record.

  The operation of this embodiment will be described below according to the flowchart of FIG.

  (Step S601) First, the control device 10 performs control so that test recording is performed on P (i) where i is an even number on the inner circumference side of the optical disc 1.

  (Step S <b> 602) Next, the control device 10 measures the recording characteristic value on the inner circumference side where the test recording has been performed by the recording characteristic measuring device 8.

  (Step S603) Next, the control device 10 executes test recording at P (i) where i is an odd number on the outer peripheral side of the optical disc 1.

  (Step S <b> 604) Next, the control device 10 measures the recording characteristic value on the outer circumference side where the test recording is performed, by the recording characteristic measuring device 8.

  Subsequent operations are the same as steps S104 and S105 of the first embodiment.

  The power order of the test recording on the inner peripheral side and the outer peripheral side may be switched using random numbers as in the second embodiment.

  FIG. 16 is a flowchart showing the procedure of the optimum recording power determination method according to the seventh embodiment of the present invention, which employs the above method. FIG. 17 is a diagram showing the order of the recording power P (i) on the inner and outer peripheral sides of the optical disc.

  (Step S701) First, the control device 10 creates an array Mj having different elements 0, 1, 2,..., N / 2-1 defined by the equation (6), and changes the order of the elements. Replace.

  (Step S <b> 702) Next, the control device 10 performs control so that test recording is executed on the inner circumference side of the optical disc 1. At this time, formula (7) is applied to the order of the recording power.

  (Step S <b> 703) Next, the control device 10 measures the recorded recording characteristic value on the inner circumference side by the recording characteristic measuring device 8.

  (Step S704) Next, the control device 10 performs control to execute test recording on the outer peripheral side of the optical disc. At this time, formula (8) is applied to the order of the recording power.

  (Step S <b> 705) Next, the control device 10 measures the recorded recording characteristic value on the outer peripheral side with the recording characteristic measuring device 8.

  Subsequent operations are the same as steps S104 and S105 of the first embodiment.

  Similarly to the second embodiment, the order of power of test recording performed on the inner and outer circumferences of the optical disc may be determined in advance and stored in the memory of the control device 10.

  FIG. 18 is a flowchart showing the procedure of the optimum recording power determination method according to the eighth embodiment of the present invention that employs this method.

  (Step S801) First, the control device 10 performs test recording on the inner peripheral side of the optical disc with the recording power sequence for the inner peripheral side stored in advance in the memory. There may be one type of recording power series, but several types of recording power may be stored in the memory and an appropriate one selected from them.

  (Step S <b> 802) Next, the control device 10 measures the recording characteristic value on the inner circumference side of the optical disk by the recording characteristic measuring device 8.

  (Step S803) Next, the control device 10 performs test recording on the outer peripheral side of the optical disc 1 in the order of the recording power stored in the memory in advance. The order of the recording power may be one, but several kinds of the order of recording power may be stored in the memory, and an appropriate one may be selected from them.

  (Step S804) Next, the control apparatus 10 measures the recording characteristic value on the outer peripheral side of the optical disc by the recording characteristic measuring apparatus 8.

  Subsequent operations are the same as steps S104 and S105 of the first embodiment.

  As described above, some embodiments of the method for calculating Po by performing test recording using the recording power sequence rearranged so that the recording powers adjacent in magnitude are discontinuous have been shown. The present invention is not limited to those shown in these embodiments, and other methods may be used as long as the dependency of the recording power on the position of the optical disk can be eliminated. According to the embodiment described above, the influence of sensitivity unevenness in OPC can be easily reduced. When the OPC accuracy is improved, it becomes possible to obtain a desired recording performance even with an optical disk having a small performance margin against a recording power error.

  Conventionally, in order to reduce sensitivity unevenness, it has been necessary to perform preprocessing before test recording, repeat OPC multiple times, or increase the physical length of test recording. Since the method itself has the effect of reducing sensitivity unevenness, it is possible to shorten the OPC execution time without having to repeat preprocessing and OPC multiple times. Similarly, since the test recording length can be shortened, the recording area of the optical disk can be saved.

  Further, the present invention can be easily used in combination with the conventional method, and an effect of further reducing the influence of sensitivity unevenness can be expected.

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 11 Sensitivity nonuniformity area

Claims (5)

Obtaining information about the period of recording sensitivity unevenness of the optical disc;
A first start position of test recording based on the acquired information on the period, and a position away from the first start position by θt / 2 × k (k is an odd number) where θt is the length of the period Calculating a second starting position which is
Test recording is performed on the optical disc using recording power sequences in which recording powers adjacent to each other in order of magnitude are allocated to test recording from the first start position and test recording from the second start position, respectively. Steps,
Measuring a recording characteristic value at a position where the test recording is performed;
Calculating the optimum recording power based on the measured recording characteristic value, and determining the optimum recording power of the optical disk recording apparatus. Calculating a period of recording sensitivity unevenness of the optical disc;
Based on the calculated period, the first start position of the test recording is at a position away from the first start position by θt / 2 × k (k is an odd number) where θt is the length of the period. Calculating a second starting position;
Performing test recording on the optical disc using recording power sequences in which recording powers adjacent in order of magnitude are allocated to test recording from the first start position and test recording from the second start position. When,
Measuring a recording characteristic value at a position where the test recording is performed;
Calculating the optimum recording power based on the measured recording characteristic value, and determining the optimum recording power of the optical disk recording apparatus. The recording power sequence arranged in the order of the size is arranged so that the recording powers adjacent to each other become discontinuous while considering the difference in recording sensitivity between the inner track and the outer track of the optical disc. A test recording step for performing test recording on the optical disc using the rearranged recording power sequence;
Measuring a recording characteristic value at a position where the test recording is performed;
Calculating the optimum recording power based on the measured recording characteristic value, and determining the optimum recording power of the optical disk recording apparatus. An optimum recording power determination method for an optical disc recording apparatus according to claim 3,
The test recording step performs test recording on the optical disc using a recording power sequence in which recording powers adjacent in order of size are allocated to an inner track and an outer track, respectively. An optimum recording power determination method for an optical disk recording apparatus. 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;
The first start position of the test recording based on the information regarding the recording sensitivity unevenness of the optical disc and the length of the period as θt, and θt / 2 × k (k is an odd number) from the first start position. A second start position, which is a distant position, was calculated, and recording powers adjacent in order of magnitude were allocated to the test record from the first start position and the test record from the second start position, respectively. Using the recording power sequence, test recording is performed on the optical disc, the recording characteristic value at the position where the test recording is performed is acquired from the recording characteristic measuring unit, and the optimum recording power is obtained based on the acquired recording characteristic value. An optical disk recording apparatus comprising: a control unit that calculates

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