JP4553869B2 - Optical information recording / reproducing apparatus, optical information recording processing method, optical information recording medium, program, and processor - Google Patents

Description

  The present invention relates to a technique for optimizing recording conditions for an optical information recording medium.

  In an optical information recording / reproducing system that records and reproduces information by irradiating an optical information recording medium with laser light, the intensity of laser light (hereinafter referred to as recording power) for each recording condition (drive, recording medium, recording speed, recording layer). In general, an OPC (Optimum Power Calibration) method is known as a method for optimizing the above. In the OPC method, prior to actual data recording, a recording pulse condition is determined in advance for a test area (specifically, a power calibration area (PCA)) on a recording medium. After fixing the condition, test recording is performed by changing the recording power condition, and the β value is calculated from the change in the recording / reproducing signal at that time, and the recording is performed so that the β value becomes a target value or a value close thereto. Identify power conditions.

Furthermore, in order to cope with changes in characteristics (sensitivity) depending on the film thickness and warping effects from the inner circumference to the outer circumference of the recording medium, the return light from the main spot, which is the data recording spot, or optical diffraction during data recording Is used to obtain an evaluation index having a β value, jitter, or correlation from the detection result of the return light from the sub-spot placed near the main spot, and the recording power condition in real time from the inner circumference to the outer circumference of the recording medium. optimize ROPC (Running Optimu m Power Calibration) technology are also generally known.

In addition, as a simple technique of the above technique, during data recording from the inner circumference to the outer circumference of the recording medium, the recording operation is temporarily stopped at a predetermined position, and the data area recorded immediately before is reproduced, thereby allowing β value, WOPC technique for optimizing the recording power condition obtained metrics (Walking Optimu m power Calibration) also having a correlation jitter or to it.

  Japanese Laid-Open Patent Publication No. 2002-100066 discloses a disk drive device that can improve the recording quality at the time of recording when recording information on a disk and can monitor the recording quality simultaneously with recording. Specifically, a diffraction grating is used to generate a zero-order light spot to be irradiated on a track on which information is to be recorded and a ± second-order light spot to be irradiated on a track separated from the track by a predetermined diffraction grating. A track in which diffraction characteristics are given and at least one of the zero-order light spot and the ± second-order light spot is separated from the track on which information is recorded by the objective lens and the track on which information is recorded by the zero-order light spot. The laser beam emitted from the semiconductor laser device by determining the recording quality of the information recorded by the zero-order light spot based on the output corresponding to the reflected laser beam from the recording medium by the ± second-order light spot. By optimizing the recording power, stable information recording is performed. However, there is no specific description about the correspondence to high-density recording systems such as HD-DVD and Blu-ray.

Furthermore, Japanese Patent Application Laid-Open No. 2002-123939 discloses a technique for controlling the laser output during pit formation in real time. Specifically, the main beam and sub beam modulated by the recording signal are emitted from the optical head, the main beam is irradiated onto the track of the optical disc to form pits, and the sub beam that does not reach the pit formation level is irradiated with the main beam. Irradiate a position near the position where no pit is formed, and the level of the return light reception signal of the main beam during the pit formation is stable and the level of the return light reception signal of the main beam and the pit formation by the main beam The laser output at the time of pit formation is controlled in real time in accordance with a value obtained by combining the return light reception signal level of the sub beam when the pit is performed. According to this, compared with the case where the laser output is controlled based only on the return light reception signal of the main beam, the change in the state of the disk is detected with high sensitivity, and the laser output is set to a value that can obtain a good recording state. It can be controlled. Even in this publication, there is no specific description about the correspondence to high-density recording systems such as HD-DVD and Blu-ray.
JP 2002-100066 A JP 2002-123939 A

  The recording power optimization method described above is a signal process for obtaining length information by converting a detected reproduction signal into binary data using a set slice level, as in the CD and DVD standards. A sufficient effect can be obtained in the system. However, in the PRML (Partial Response and Maximum Likelihood) signal processing system used in standards such as HD-DVD and Blu-ray, the ideal state of the amplitude data of the reproduction signal is defined according to each code data and its arrangement, The error depends on the amount of deviation from the ideal state. For this reason, management of asymmetry indicating the positional relationship (asymmetry) of the amplitude level of each code data is required. Specifically, in the HD-DVD and Blu-ray standards, asymmetry between short codes such as the shortest code 2T and the next longest 3T code used in each modulation method, or equivalent to the longest code in a range of 4T or more It is desirable to manage the asymmetry between long and short codes having the following amplitude. The β value described above is an index having a correlation with the asymmetry in the characteristic range, and is not invalid at all. However, since the correlation formula changes depending on the recording conditions such as the recording speed, it is necessary to obtain the correlation formula for each recording condition, which is not practical in view of the required time. In addition, it is conceivable to store the data of the correlation equation in the memory in advance. However, the development cost and time for that will be borne, and differences due to individual variations of the drive and recording medium, the outside air temperature, etc. Occurrence is also a problem. Also, a method of predicting and correcting according to the recording condition based on the correlation equation obtained at the time of test recording with respect to the PCA is conceivable.

  In addition, in the OPC method, a countermeasure that detects asymmetry and uses it as an evaluation index can be considered, but as described above, characteristics (sensitivity) depending on the film thickness from the inner periphery to the outer periphery of the recording medium and the influence of warpage, ) Response to changes and response to multilayer recording media having a plurality of recording layers are problematic.

  Since the WRF signal during recording used in the ROPC method is difficult to obtain sufficient characteristics due to the blunting of the signal near the laser irradiation start position and the influence of overshoot, the position is a little after the laser irradiation start position. Generally, a stable signal level from the laser irradiation end position to the laser irradiation end position is used. However, when considering asymmetry detection or detection of an evaluation index having a correlation therewith, a sufficiently long stable period is required for short code data (for example, the shortest code is 2T in the case of HD-DVD standard or Blu-ray standard). Because it is difficult to obtain, it is difficult to realize. It is also necessary to add a means for avoiding the influence of the recording pulse modulation in a circuit.

  In the WOPC method, since the recording operation is temporarily stopped and normal reproduction is performed, the problems of the ROPC method can be solved. However, since the recording stop time and the search time to the detection start position and the recording restart position are required. An increase in the total recording time according to the number of stops is a problem. In particular, in the HD-DVD standard in which the data recording capacity is 3 to 4 times as high as that of DVD (high density), the system margin is greatly reduced, and the mechanical characteristics management and servo of the recording medium are reduced. In addition to the extremely severe characteristics, considering the thickness and warpage variation of the multilayer recording medium, it is considered essential to increase the stop operation described above, increasing the recording time and degrading the recording characteristics between the stop positions. Is a problem.

  Accordingly, an object of the present invention is to provide a technique for calculating asymmetry over the inner and outer circumferences of a recording medium in a short time, simply and accurately.

  Another object of the present invention is to provide a technique for dynamically executing recording power control in accordance with an asymmetry calculation result.

  The optical information recording / reproducing apparatus according to the first aspect of the present invention provides the above recording during the formation of a space between recording marks formed by laser irradiation in a laser irradiation period in which data recording is performed on a recording track of an optical information recording medium. Means for acquiring a reproduction signal from a subsequent track (also referred to as an already recorded track) in which data recording has been performed before the track, code identification means for arbitrarily identifying a plurality of code data included in the reproduction signal, and reproduction signal Calculating means for calculating an asymmetry value from the amplitude data of the data and the code corresponding to the reproduction signal.

  As described above, if a reproduction signal is obtained for the succeeding track and the asymmetry value is calculated for the reproduction signal even though data is being recorded, the track to be further subjected to data recording in a short time, simply and accurately. Accordingly, the asymmetry value can be calculated over the inner and outer circumferences of the recording medium.

  Further, it may further comprise a control means for controlling the recording power of the laser based on the asymmetry value calculated by the calculation means. In this way, it becomes possible to perform dynamic recording power control in accordance with changes in the asymmetry value.

  Further, the control means includes means for comparing the asymmetry value calculated by the calculation means with at least one of a target value and an allowable value, and means for controlling the recording power of the laser based on the comparison result. You may make it. For example, the asymmetry value can be controlled to be close to the target value, or can be controlled to be within the range defined by the allowable value. It should be noted that the control may be performed periodically or when the range defined by the allowable value is exceeded.

  Further, at least one of the target value and the allowable value is recorded in the memory or the optical information recording medium, and at least one of the target value and the allowable value is read from the memory or the optical information recording medium. Also good.

  Further, the code identification means may include means for synchronizing the reproduction signal and the recording pattern signal generated for data recording. The code identification means may include a PRML decoding processing unit for the reproduction signal, and the processing result of the PRML decoding processing unit and the reproduction signal may be output in synchronization.

  Further, at least one of the asymmetry value and the control content (for example, data such as recording power value, acquisition parameter, and other recording / reproducing conditions) is stored in a storage device (memory, optical information recording medium, storage device of other external device, etc.) Or you may make it further have a means to output to an output part (a display part, an external display part, a printing part, etc.). Thereby, the subsequent processing may be simplified or made efficient.

  The optical information recording medium according to the second aspect of the present invention provides the above recording during the formation of a space between recording marks formed by laser irradiation in a laser irradiation period in which data recording is performed on a recording track of the optical information recording medium. At least one of a target value and an allowable value of an asymmetry value calculated for a reproduction signal from a subsequent track in which data was recorded before the track is recorded. By using such an optical information recording medium, the memory capacity of the optical information recording / reproducing apparatus can be reduced, and it is possible to appropriately cope with an optical information recording medium that will newly appear in the future. In addition to reducing the required time and cost in the development and production of optical information recording / reproducing devices, the optimum recording conditions can be adjusted for existing recording media whose optical information recording / reproducing devices do not recognize the type. This makes it possible to construct a more stable recording / playback system.

  In the optical information recording processing method according to the third aspect of the present invention, in the laser irradiation period for performing data recording on the recording track of the optical information recording medium, the recording is performed during the space formation between the recording marks formed by laser irradiation. A step of acquiring a reproduction signal from a subsequent track on which data recording has been performed before the track, a code identification step for arbitrarily identifying a plurality of code data included in the reproduction signal, amplitude data of the reproduction signal, and the reproduction signal And a calculation step of calculating an asymmetry value from a code corresponding to.

  Further, there may be a control step for controlling the recording power of the laser based on the asymmetry value calculated in the calculation step.

  A program for causing the processor to execute the present optical information recording processing method can be created. This program can be stored in a storage medium such as a flexible disk, an optical information recording medium, a magneto-optical disk, a semiconductor memory, a hard disk, or the like. It is stored in a processor having a device and a memory. Moreover, it may be distributed as a digital signal via a network or the like. The intermediate processing result is temporarily stored in a work memory area of various storage devices.

  According to the present invention, asymmetry can be calculated over the inner and outer circumferences of the recording medium in a short time, simply and accurately.

  In addition, according to another aspect of the present invention, it becomes possible to dynamically control the recording power in accordance with the asymmetry calculation result.

  FIG. 1 shows a functional block diagram of a drive system according to an embodiment of the present invention. The drive system according to the embodiment of the present invention includes an optical information recording / reproducing apparatus 100, and an input / output system 200 including a display unit 202 such as a television receiver and an operation unit 201 such as a remote controller.

  The optical information recording / reproducing apparatus 100 includes a memory 109 that stores data in the middle of processing, data of processing results, reference data in processing, and the like, and a memory circuit 121 in which a program for performing processing described below is recorded. A controller 120 that is a processor that controls the entire optical information recording / reproducing apparatus 100 by executing the program, an interface unit (I / F) 101 that is an interface with the input / output system 200, and an optical information recording / reproducing apparatus. An encoder for performing an encoding process such as adding an error correction code to recording data from a tuner or other data storage unit provided in 100 or recording data input from another device via the I / F 101 102 and processing for applying predetermined modulation to the output of the encoder 102, etc. An optical pickup unit 110 including a modulation circuit 103 to be implemented, a laser drive circuit 104 that generates a signal for driving the laser 111 according to an output from the modulation circuit 103, a light detection unit 112 such as a laser 111 and a photodiode, and an encoder A gate signal generation unit 105 that generates a gate signal described below from the output of 102, an A / D conversion circuit 106 that converts an analog signal generated by the light detection unit 112 into a digital signal, and an A / D conversion circuit 106 A code identifying unit 107 that performs a code identifying process as described below from the output from the signal, and a detection that performs a detection process described below according to the gate signal from the gate signal generating unit 105 with respect to the output from the code identifying unit 107 Error correction and the like for the outputs from the unit 108 and the code identification unit 107 And a decoder 131 to carry out the cord treatment. The optical information recording / reproducing apparatus 100 includes a rotation control unit and a motor of the disk 150 (not shown), a servo control unit for the optical pickup unit 110, and the like. Further, a gain adjustment unit, an amplifier, an equalizer, and the like that are not directly related to the present embodiment are omitted.

  The controller 120 is an operation control function of the I / F 101, the encoder 102, the modulation circuit 103, the code identification unit 107, the detection unit 108, and the decoder 131, a function of registering an output from the detection unit 108 in the memory 109, and an asymmetry value calculation. A function of calculating a recording power correction amount from an asymmetry value (or deriving a recording power value to be set) and setting the recording power for the laser driving circuit 104.

  The output of the encoder 102 may be used by the code identifying unit 107 as described below. Further, the output of the decoder 131 is output to the display unit 202 via the I / F 101 under the control of the controller 120.

  Next, an outline of processing when data is recorded on the disk 150 will be described. First, the encoder 102 performs error correction coding on recording data from a tuner or other data storage unit provided in the optical information recording / reproducing apparatus 100 or recording data input from another apparatus via the I / F 101. Is encoded and output to the modulation circuit 103 as write data. The modulation circuit 103 performs, for example, ETM modulation processing on the write data, and outputs the modulated data to the laser driving circuit 104. The laser drive circuit 104 drives the laser 111 of the optical pickup unit 110 with the data from the modulation circuit 103 according to the recording conditions set by the controller 120 to output laser light. The laser beam is irradiated onto the disk 150 through an optical system (not shown), and spaces (lands) and pits are formed on the disk 150. As will be described in detail below, in this embodiment, the recorded track is reproduced (read) at the time of land formation, and the recording power, which is a recording condition, is dynamically corrected based on the result. .

  An outline of processing when data recorded on the disk 150 is reproduced will be described. In accordance with an instruction from the controller 120, the laser drive circuit 104 drives the laser 111 to output laser light. The laser beam is applied to the disk 150 through an optical system (not shown). The reflected light from the disk 150 is input to the light detection unit 112 via an optical system (not shown). The light detection unit 112 converts the reflected light from the disk 150 into an analog electric signal and outputs it to the A / D conversion circuit 106. The A / D conversion circuit 106 converts the analog electric signal into a digital signal and outputs the digital signal to the code identification unit 107. The code identification unit 107 performs a predetermined code identification process and outputs the processing result to the detection unit 108 and the decoder 131. The decoder 131 performs processing such as predetermined error correction on the processing result of the code identification unit 107, and outputs the processing result to the display unit 202 of the input / output system 200 via the I / F 101 according to the instruction of the controller 120. Display playback data.

  Further, the detection unit 108 outputs data as described below to the controller 120 during the period instructed by the gate signal output from the gate signal generation unit 105. The controller 120 calculates a predetermined asymmetry value, calculates a recording power correction amount that is a recording condition from the calculated asymmetry value, and sets a new recording condition in the laser drive circuit 104. This will be described in detail below.

  Next, processing contents of the drive system shown in FIG. 1 will be described with reference to FIGS.

(1) Initial setting process (step S1)
First, the controller 120 stores the initial basic information (for example, the optimum recording power value, the data representing the relationship between the asymmetry value and the recording power value, the asymmetry stored in advance in the memory 109 and necessary for the recording power correction process described below). (Conditions such as target value and asymmetry allowable value) are read (step S1). Note that the initial basic information may not be stored in the memory 109, but in that case, it may be generated using another technique. Further, since the initial basic information varies depending on the media ID, the media ID of the disk 150 on which data is recorded this time is read out, and the corresponding initial basic information is read out.

(2) Recording power setting, etc. (step S3)
Further, at the start of data recording, the controller 120 sets a recording condition including the optimum recording power value acquired in step S1 in the laser driving circuit 104, and the recording power correction amount is calculated in step S11 described below. In this case, a recording condition including the recording power correction amount or a recording power value resulting from reflecting the recording power correction amount in the current recording power value is set in the laser drive circuit 104 (step S3). The laser driving circuit 104 performs laser irradiation according to the output from the modulation circuit 103 according to the setting from the controller 120.

  Note that the output from the encoder 102 is, for example, a signal as shown in FIG. In the example of FIG. 3A, the signal waveform is arranged in the order of P2, L2, P8 to 11, L2, P2, and L8. For example, for example, P2 represents a recording pulse for forming a mark having a length of 2T (T is a predetermined unit length), and P8 to 11 are recording pulses for forming a mark having a length of 8T to 11T. It shall represent. Similarly, L2 represents a recording pulse for forming a space having a length of 2T, and L8 represents a recording pulse for forming a space having a length of 8T. In the case of multi-pulses, the modulation circuit 103 generates a write pulse (WritePulse) signal as shown in FIG. Further, in the case of non-multipulses, the modulation circuit 103 generates a write pulse (WritePulse) signal as shown in FIG. The parts P8 to 11 are divided into a predetermined number of pulses in the case of a multi-pulse, but an intermediate amplitude part is generated in the case of a non-multi-pulse. The pulse signal generation technique as shown in FIG. 3B or 3C is well known and will not be described further.

(3) Gate signal generation (step S5)
Further, the output of the encoder 102 (for example, FIG. 3A) is also input to the gate signal generation unit 105, and the gate signal generation unit 105 inverts the output of the encoder 102 so as to invert the gate signal (FIG. 3D). ) And output to the detection unit 108 (step S5).

  As described above, according to the present embodiment, the amplitude information of the reproduction signal (here, the output of the code identification unit 107) is detected while the space (land) between the recording marks is formed on the disk 150, and the asymmetry value is obtained. It is used for calculation. This has the advantage that the detection of amplitude information is not affected by the recording mark being formed or by the recording pulse modulation. For this reason, the detection timing of amplitude information is defined by a gate signal. For example, when the “1” level of the signal shown in FIG. 3A is the mark formation level, detection is performed during the “0” level. Therefore, as illustrated in FIG. 3D, the gate signal generation unit 105 inverts the signal illustrated in FIG. 3A to generate a gate signal. Note that, in any recording pulse modulation method as shown in FIGS. 3B and 3C, both levels are “0” when a space (land) is formed, and therefore the amplitude is not affected by the recording pulse modulation method. Information can be detected.

(4) Code identification process (step S7)
In steps S3 and S5, data is written on the disk 150, and data is read from an already recorded track (also referred to as a subsequent track) on the disk 150. However, due to the characteristics of the optical pickup unit 110, the recorded track that can be read during writing is somewhat separated from the track being written, and the length of the reproduction signal (xT (x is 2 or more, for example) It is necessary to correctly identify whether the sign is an integer).

  That is, the analog electric signal generated by the light detection unit 112 of the optical pickup unit 110 in accordance with the reflected light is converted into a digital signal by the A / D conversion circuit 106, that is, a reproduction signal from a recorded track at a predetermined position. On the other hand, the code identification unit 107 performs code identification processing (step S7).

  Specifically, in the code identification unit 107, for example, as shown in FIG. 4, the output of the encoder 102 is connected to a delay unit 301 that causes a delay of a predetermined time, and the output of the delay unit 301 is output to the detection unit 108. , One of the outputs from the A / D conversion circuit 106 is connected to the detection unit 108 as it is, the other is connected to the Viterbi decoder 302 that performs Viterbi decoding processing, and the output of the Viterbi decoder 302 is connected to the decoder 131. To do. In the example of FIG. 4, since the output of the encoder 102 used for writing is read after a predetermined time, a delay unit 301 that causes a delay for a predetermined time is provided to synchronize the recording data and the reproduction signal. . Note that the Viterbi decoder 302 is used during normal playback, and thus description thereof is omitted here.

  The time to delay is determined as follows. That is, the relationship between the recording position and the distance difference between the recording position and the reading position is represented by a graph as shown in FIG. 5, for example. That is, as the recording position (specifically, the distance from the recording start position) increases, the distance difference also increases in proportion. Accordingly, the distance difference between the recording position and the reading position in the disk 150 having the spirally formed tracks is obtained from information such as the recording position and the track pitch, and further, the distance difference is divided by the recording speed to delay. Ask for time. As described above, the delay unit 301 synchronizes the output of the encoder 102 and the reproduction signal while dynamically changing the delay time, and outputs the output of the encoder 102 as a code identification result at an appropriate timing. That is, the reproduction signal as shown in FIG. 6A and the output (WriteData) of the encoder 102 as shown in FIG. 6B are synchronized.

  Further, the code identification unit 107 may be configured as shown in FIG. 7, for example. That is, the output from the A / D conversion circuit 106 is input to a delay unit 351 and a Viterbi decoder 352 that cause a delay of a predetermined time, and the output of the delay unit 351 and one output of the Viterbi decoder 352 are detected by the detection unit. The other output of the Viterbi decoder 352 is output to the decoder 131. In this example, a Viterbi decoding process by the Viterbi decoder 352, which is normally required in PRML, is performed on the output from the A / D conversion circuit 106, and the processing result is output to the detection unit 108 as a result of the code identification process. . In the case of normal reproduction processing, the same processing is performed and output to the decoder 131. Since the output from the A / D conversion circuit 106 is processed as it is, there is no change in the delay time according to the recording position. However, since the output from the A / D conversion circuit 106 cannot be synchronized unless the output from the A / D conversion circuit 106 is delayed by the processing time of the Viterbi decoding process, a delay unit 351 for delaying by the processing time is provided as an A / D conversion circuit. 106 is connected. In this way, the reproduction signal as shown in FIG. 8A and the Viterbi decoding process output as shown in FIG. 8B are synchronized.

(5) Detection of amplitude information and calculation of asymmetry (step S9)
The detection unit 108 calculates the amplitude value in the reproduction signal from the code identification unit 107 during the period instructed by the gate signal from the gate signal generation unit 105 (period “1” in the case of FIG. 3D). At the same time, the amplitude value and the code identification result at that time are output to the controller 120 and stored in the memory 109. As the asymmetry value, in the case of the HD-DVD standard, an asymmetry value of 2T3T, an asymmetry value of 2T11T, an asymmetry value of 3T11T, and the like are normally used. Therefore, the amplitude value stored in the memory 109 according to the asymmetry value to be calculated The code identification result may be limited. That is, when the 2T3T asymmetry value is calculated, only the amplitude value corresponding to the 2T code and the amplitude value corresponding to the 3T code may be stored in the memory 109. When the 2T11T asymmetry value is calculated, only the amplitude value corresponding to the 2T code and the amplitude value corresponding to the 11T code may be stored in the memory 109. Similarly, when the 3T11T asymmetry value is calculated, only the amplitude value corresponding to the 3T code and the amplitude value corresponding to the 11T code may be stored in the memory 109. When all 2T3T asymmetry values, 2T11T asymmetry values, and 3T11T asymmetry values are calculated, only amplitude values corresponding to 2T codes, amplitude values corresponding to 3T codes, and amplitude values corresponding to 11T codes are used. It may be stored in the memory 109. An arbitrary combination of two or more may be employed instead of all, and in that case, an amplitude value corresponding to a code necessary for the combination is stored. The memory 109 preferably stores an amplitude value for each code. In addition, when the modulation method to be used is different as in the Blu-ray standard, it is desirable to perform code amplitude value storage and asymmetry calculation suitable for it.

  In addition, since it is difficult to obtain sufficient amplitude information in one period indicated by the gate signal, the amplitude information obtained in a plurality of periods is stored in the memory 109, and a predetermined number of detection results are obtained. It is desirable to calculate an asymmetry value at the accumulated stage. The predetermined number is a predetermined number of samples necessary for accurately calculating the asymmetry value. In addition, when the period indicated by the gate signal is not sufficiently long, that is, when the land formation period is short, the amplitude information is not detected and only when the period indicated by the gate signal is sufficiently long. Detection may be performed.

  The controller 120 calculates the asymmetry value at a predetermined timing using the data stored in the memory 109 as described above (step S9). In addition, since the calculation method of an asymmetry value is well-known, detailed description is abbreviate | omitted here.

  A specific example of spot conditions when amplitude information is detected from a recorded track (following track) will be described. In the case of detecting with the main beam, as shown in FIG. 9A, the recording state of the subsequent track is detected using the return light of the main spot 401 for forming the recording mark and the space. The spot condition to be used may be a one-beam system having only one main spot 401 as shown in FIG. 9A, or the first-order diffracted light or 2 other than the main spot 402 as shown in FIG. 9B. A multi-beam system having sub-spots 403 and 404 by the next diffracted light may be used. This method is a detection method utilizing the amount of crosstalk to the main spot 401 or 402, and is necessary for the detection signal when sufficient CN (Carrier to Noise) is required in the detection signal. Perform gain control.

  Further, as shown in FIGS. 10A and 10B, when sub-beams are detected, sub-spots 453 and 454 or 455 to 458 based on first-order diffracted light and second-order diffracted light are used instead of main spots 451 and 452. The recording state of the subsequent track is detected using the return light of the sub-spots 453 and 454 or 455 to 458 using the multi-beam optical pickup unit 110 having the multi-beam method. As in the case of the main beam, when it is necessary to secure sufficient CN in the detection signal, necessary gain control is performed on the detection signal.

(6) Calculation of recording power correction amount (step S11)
In response to the asymmetry value calculated in step S9, the controller 120 calculates a recording power correction amount or a set recording power value when it is deemed necessary according to a predetermined policy (step S11). The calculated recording power correction amount and the like are used for setting the recording power in step S3.

  The case where it is recognized that it is necessary according to a predetermined policy may be, for example, every fixed time interval, or may be a case where the asymmetry value calculated in step S9 is out of a predetermined allowable range. The asymmetry value is preferably a target value (for example, 0), and the recording power is corrected so that the asymmetry value calculated in step S9 becomes or approaches the target value. If the recording power may deviate from the setting range of the recording power, the correction amount may be determined so as to fall within the allowable range.

  FIG. 11 shows the time change of the asymmetry value when correction is performed so that the asymmetry value becomes the target value at regular time intervals. In FIG. 11, the vertical axis represents asymmetry value (%), and the horizontal axis represents time. Since correction is performed at regular time intervals, the asymmetry value rises and falls in the vicinity of the target value. When such control is performed, the upper limit value and the lower limit value that define the allowable range may not be used as long as the predetermined time interval is appropriately set. Further, when the fixed time interval is relatively long, the asymmetry value may be controlled to approach the target value when the allowable range is not met even within the fixed time interval. The horizontal axis may be the recording position of the recording medium. This is because the recording time on the recording medium and the recording position are correlated. Further, the method is not limited to the case where data is continuously recorded from the inner periphery to the outer periphery of the recording medium, and can be applied to additional recording, partial recording, and the like.

  FIG. 12 shows the time change of the asymmetry value when correction is performed so that the asymmetry value becomes the target value when the asymmetry value calculated in step S9 is outside the predetermined allowable range. Also in FIG. 12, the vertical axis represents the asymmetry value (%), and the horizontal axis represents time. In the example of FIG. 12, the asymmetry value that was close to the target value gradually falls and falls below the lower limit value at the portion indicated by the circle 601. At that time, the recording power is corrected, and control is performed so that the asymmetry value becomes the target value again. Such control may be performed. In FIG. 12, the horizontal axis may be the recording position of the recording medium. Further, the method is not limited to the case where data is continuously recorded from the inner periphery to the outer periphery of the recording medium, and can be applied to additional recording, partial recording, and the like.

  Further, the recording power correction amount is desirably obtained from the relationship between the recording power and the asymmetry value as shown in FIG. In the example of FIG. 13, the horizontal axis represents the recording power, and the vertical axis represents the asymmetry value. The relationship between the asymmetry value of 2T3T and the recording power. The relationship between the asymmetry value of 2T11T and the recording power. And the recording power. Such a relationship is registered in advance in the memory 109 or the disk 150 and used. Alternatively, it may be calculated during the recording / reproducing operation and stored in the memory 109. In the example of FIG. 13, the relationship between the asymmetry value and the recording power is approximated linearly, and the relationship between the asymmetry value Y and the recording power X is expressed as Y = aX + b by a predetermined proportional coefficient a and intercept b. Then, the correction amount of X is calculated so that Y = 0. Note that, instead of the correction amount, a necessary recording power may be specified and set in the laser driving circuit 104.

  Furthermore, the asymmetry value to be calculated is not limited to one type, and a plurality of types of asymmetry values may be calculated. For example, asymmetry values between short data codes (for example, 2T3T asymmetry values) and asymmetry values between short data codes and long data codes (for example, 2T11T asymmetry values or 3T11T asymmetry values). Asymmetry values may be detected, and the recording power may be optimized so that each asymmetry value approaches the ideal state. In this case, the relationship between the recording power and the asymmetry value is also prepared for each asymmetry value.

  FIG. 13 shows an example in which the asymmetry value increases as the recording power increases. However, the present embodiment is not limited to this, and the reverse may occur depending on the type of the disk 150 and the characteristics of the disk 150. In some cases, the asymmetry value decreases, or there is almost no change.

(7) Recording end judgment (step S13)
The controller 120 does not improve the asymmetry value by correcting the recording power as described above (for example, the asymmetry value does not fall within the allowable range even if the recording power is corrected), or the asymmetry value is reduced to the allowable range. Whether or not to end the recording operation is determined based on whether or not a recording power value sufficient for correction cannot be set (because the recording power setting limit level has been reached) is detected (step S13). When the above situation is detected, it may be determined that the recording operation is finished immediately, or only when the recording speed cannot be reduced any more, it is determined that the recording is finished. If it is possible to decrease the recording speed, the recording speed may be decreased and the process may return to step S3. Further, the process returns to step S3 even when the control is performed without any particular problem. Also, it is determined that the process is ended when the user gives an end instruction.

(8) Storage / display of predetermined information (step S15)
If the controller 120 determines that the recording has ended and is determined in step S13, the media ID read from the disk 150, an asymmetry value calculation history, a recording power or a recording power correction amount setting history, other acquired values, a determination Results, processing results, recording / playback conditions, acquisition parameters, and the like are displayed on the display unit 202 of the input / output system 200, for example, via the I / F 101 (step S15). As a result, the user can obtain information such as what kind of recording has been performed, whether or not many recording power adjustments have been required for the disk 150, and whether or not data recording has been stopped halfway. For example, it can be used as a guide for selecting the disk 150. Further, the above data is recorded in the memory 109 for use in a subsequent recording operation or the like with or without display. For example, the initial recording power can be appropriately set for the disks 150 having the same media ID. Further, the stored data can be utilized to efficiently perform the subsequent recording operation.

  Further, the above data may be stored in the disk 150 instead of or in addition to the memory 109. When saving to the disk 150, for example, the ID of the optical information recording / reproducing apparatus 100 is saved instead of the media ID in the saved data for the memory 109 described above. In this case, in the case of a write-once disc 150 or the like, in the case where data recording is performed again by the same optical information recording / reproducing apparatus 100 as the ID of the optical information recording / reproducing apparatus 100 stored in the disc 150, the disc 150 It is possible to appropriately set the initial recording power by using the recording related data stored in.

  By performing the processing as described above, the recording power is dynamically adjusted without stopping the data recording because the detection processing is performed by performing the read operation of the recorded track in parallel with the data recording operation. Will be able to do. Since the detection process is performed only during the formation of a space (ie, land), the detection process can be performed without having to remove the influence of modulation on the recording data. Further, since the code identification unit 107 as described above is used, signal data of low frequency data (that is, long code data) can be arbitrarily obtained from high frequency data (that is, short code data), and a necessary asymmetry value can be obtained. Calculation is possible. Since the asymmetry value is directly acquired in this way, systematic error generation factors such as conversion error, prediction error, and individual difference effects can be avoided and stable recording power adjustment can be performed. Whether it is the inner side or the outer side of the disk 150 can be specially handled by adjusting the recording power by performing detection processing together with data recording.

  Therefore, accurate marks and spaces can be formed even in high-density recording systems such as DVD, HD-DVD, and Blu-ray. Especially in a recording / reproducing system using PRML signal processing, a high error rate, wide margin, etc. Recording quality can be obtained.

  In the embodiment described above, an example in which the memory 109 stores reference values such as an upper limit value and a lower limit value representing the target value and the allowable range, data representing the relationship between the asymmetry value and the recording power, and the like. Although shown, it is not necessarily held in the memory 109. For example, it may be held on the disc 150 of the HD-DVD standard. When it is held on the disk 150, it is held in the Lead-in area as shown in FIG. The lead-in area is largely divided into a system lead-in area, a connection area, and a data lead-in area. The system lead-in area includes an initial zone, a buffer zone, a control data zone, and a buffer. -Includes zones. The connection area includes a connection zone. Further, the data lead-in area includes a guard track zone, a disc test zone, a drive test zone, a guard track zone, an RMD duplication zone, a recording management zone, an R-physical format information zone, and a reference code. -Includes zones. In the present embodiment, the recording condition data zone 170 is included in the control data zone of the system lead-in area.

  In this recording condition data zone 170, the data to be stored in the memory 109, in particular, the data indicating the reference value (target value, upper limit value, lower limit value, etc.) and the relationship between the asymmetry value and the recording power are stored. Read out when necessary. As for the value to be recorded, an average value of the disk 150 may be registered uniformly, or a value corresponding to a test before shipment may be registered for the disk 150.

  Note that data to be stored in step S15 may also be stored in the same zone.

  In the example of FIG. 1, an example in which a television receiver and a remote controller are assumed as the input / output system 200 is shown, but for example, a personal computer 180 may be connected as shown in FIG. 15. The optical information recording / reproducing apparatus 100 may be integrated with a personal computer.

  15, the personal computer 180 includes a display unit 181 that is a display, an input unit 182 that is a keyboard and a mouse, and a data recording processing unit 183 that is realized by executing software. included. The data recording processing unit 183 communicates with the controller 120 via the I / F 101, receives display data, displays it on the display unit 181 and receives an input from the input unit 182 and outputs it to the controller 120. Perform the process. Note that the data recording processing unit 183 may be realized by being integrated with, for example, existing disc writer software.

  1, 4 and 7 are examples, and similar results can be obtained with other module configurations.

It is a functional block diagram concerning an embodiment of the invention. It is a figure which shows the main process flow in embodiment of this invention. (A) is a waveform example of recording data, (b) is a write pulse waveform example in the case of multi-pulse, (c) is a write pulse waveform example in the case of non-multi pulse, and (d) is a diagram showing a waveform example of a gate signal. . It is a figure which shows the 1st structural example of a code | symbol identification part. It is a figure which shows the relationship between the distance difference of a recording position and a reading position. (A) is a waveform example of a reproduction signal, and (b) is a diagram showing a waveform example of WriteData. It is a figure which shows the 2nd structural example of a code | symbol identification part. (A) is a figure which shows the example of a waveform of a reproduction signal, (b) is a figure which shows the example of a waveform of Viterbi decoding process output. (A) and (b) is a diagram showing an example of a case of performing discovery at the main beam. (A) And (b) is a figure which shows the example in the case of detecting by a sub beam. It is a figure which shows the 1st example of the time change of an asymmetry value. It is a figure which shows the 2nd example of the time change of an asymmetry value. It is a figure which shows the relationship between recording power and an asymmetry value. It is a figure which shows the data structure stored in a disk. It is a functional block diagram in the case of using a personal computer.

Explanation of symbols

100 Optical information recording / reproducing apparatus 101 I / F
DESCRIPTION OF SYMBOLS 102 Encoder 103 Modulation circuit 104 Laser drive circuit 105 Gate signal generation part 106 A / D conversion circuit 107 Code identification part 108 Detection part 109 Memory 131 Decoder 110 Optical pick-up unit 111 Laser 112 Photodetection part 120 Controller 121 Memory circuit 200 Input / output system 201 Operation unit 202 Display unit

Claims (16)

In a laser irradiation period in which data is recorded on a recording track of an optical information recording medium, a reproduction signal from a subsequent track in which data recording was performed before the recording track during the formation of a space between recording marks formed by laser irradiation Reproduction signal acquisition means for acquiring
The reproduction signal and the recording pattern signal generated for the data recording are synchronized, and the reproduction signal is associated with the code data included in the reproduction signal and the code data included in the recording pattern signal. and identify different codes identifying means a plurality of code data included in,
Calculating means for calculating an asymmetry value from amplitude data of the reproduction signal and a code corresponding to the reproduction signal;
An optical information recording / reproducing apparatus. The optical information recording / reproducing apparatus according to claim 1, further comprising: a control unit that controls the recording power of the laser based on the asymmetry value calculated by the calculation unit. The control means is
Means for comparing the asymmetry value calculated by the calculating means with at least one of a target value and an allowable value;
Based on the comparison result, means for controlling the recording power of the laser;
An optical information recording / reproducing apparatus according to claim 2 including: At least one of the target value and the allowable value is recorded in a memory or the optical information recording medium,
4. The optical information recording / reproducing apparatus according to claim 3, wherein at least one of the target value and the allowable value is read from the memory or the optical information recording medium. 5. The light according to claim 1, wherein the code identification unit includes a PRML decoding processing unit for the reproduction signal, and outputs the processing result of the PRML decoding processing unit and the reproduction signal in synchronization with each other. Information recording / reproducing apparatus. The optical information recording / reproducing apparatus according to claim 2, further comprising: means for outputting at least one of the asymmetry value and the control content to a storage device or an output unit. The reproduction signal acquisition means is
Based on the amount of crosstalk to the main spot specified from the return light of the main beam that forms the space, or using the return light of the sub beam that is the diffracted light of the main beam, the reproduction signal from the subsequent track is acquired. Do
The optical information recording / reproducing apparatus according to claim 1. In a laser irradiation period in which data is recorded on a recording track of an optical information recording medium, a reproduction signal from a subsequent track in which data recording was performed before the recording track during the formation of a space between recording marks formed by laser irradiation A reproduction signal acquisition step for acquiring ,
The reproduction signal and the recording pattern signal generated for the data recording are synchronized, and the reproduction signal is associated with the code data included in the reproduction signal and the code data included in the recording pattern signal. and code identification step that identifies a plurality of code data included in,
A calculation step of calculating an asymmetry value from the amplitude data of the reproduction signal and a code corresponding to the reproduction signal;
An optical information recording processing method. The optical information recording processing method according to claim 8 , further comprising a control step of controlling the recording power of the laser based on the asymmetry value calculated in the calculating step. The control step comprises:
Comparing the asymmetry value calculated in the calculation step with at least one of a target value and an allowable value;
Controlling the recording power of the laser based on the comparison result;
The optical information recording processing method according to claim 9 . At least one of the target value and the allowable value is recorded in a memory or the optical information recording medium,
The optical information recording processing method according to claim 10 , wherein at least one of the target value and the allowable value is read from the memory or the optical information recording medium. The code identification step comprises
Performing PRML decoding on the reproduced signal;
Outputting the processing result of the PRML decoding process and the reproduction signal in synchronization;
The optical information recording processing method according to claim 8 , comprising: The optical information recording processing method according to claim 9 , further comprising: outputting at least one of the asymmetry value and the control content to a storage device or an output unit. In the reproduction signal acquisition step,
Based on the amount of crosstalk to the main spot specified from the return light of the main beam that forms the space, or using the return light of the sub beam that is the diffracted light of the main beam, the reproduction signal from the subsequent track is acquired. Do
The optical information recording processing method according to claim 8. 15. A program for causing a processor to execute the optical information recording processing method according to any one of claims 8 to 14 . A processor having a memory for storing the program according to claim 15 .

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