JP3734814B2 - Optical disc apparatus, parameter determination method, program, and storage medium - Google Patents

Description

  The present invention relates to an optical disc device, a parameter determination method, a program, and a storage medium.

  Patent Document 1 discloses a recording layer designating unit for designating a desired recording layer for focusing on a multilayer optical disc, a focus search generator for focusing on a designated recording layer, an objective lens moving direction detection circuit, and the like. A maximum value detection circuit and a minimum value detection circuit for detecting a maximum value and a minimum value of a focus error signal corresponding to each recording layer, a storage circuit for temporarily storing maximum data and minimum data from each detection circuit, and An arithmetic circuit that subtracts the minimum value data from the maximum value data read from the storage circuit, and a focus error normalization circuit that normalizes the focus error signal based on the arithmetic data from the arithmetic circuit. A focus control device is disclosed.

Japanese Patent Laid-Open No. 08-185636

  In general, an optical disk that can be additionally recorded or rewritten uses a function called power calibration (OPC: Optimum Power Control) to detect the optimum power of a laser beam for recording before attempting to record information. ing.

  A general power calibration method will be described below. That is, on the recording surface of the optical disc, a data area for recording various data, a test recording area (PCA: Power Calibration Area, hereinafter referred to as PCA) for detecting the optimum power of the laser beam, and the like are provided. The PCA is composed of a test area and a count area. The test area is composed of 100 partitions, and each partition is composed of 15 frames. In one OPC operation, one of the partitions is used, and 15 frames included in each of these partitions are subjected to test recording with at least two or more laser powers. The test signal is reproduced, the reproduced signal is compared with the target value, and the laser power at the stage where the two match is detected as the optimum power. The information recording operation for the data area is performed by the optimum power detected by the OPC operation as described above.

  Then, when the optimum power as described above is detected and information is recorded, the recording quality is set to a target value. In practice, however, the parameter that determines the recording quality is, for example, in the focus direction of the objective lens. Others exist, such as However, in the OPC operation in a normal optical disc apparatus, only laser power is used as a parameter, and other parameters relating to recording quality are not taken into consideration.

  In addition, when reproducing and recording information, the relative position of the objective lens that focuses light on the optical disc in the focus direction with respect to the optical disc is the same as that of the optical disc that is to be reproduced or recorded, as seen in Patent Document 1. It is common to focus accurately on the focus position of the desired layer. In this case, the relative position of the objective lens with respect to the optical disc in the focus direction when recording information is different from the optimum position for reproduction, and the objective lens is moved in the focus direction so as to optimize the recording jitter. It is common to record.

  However, in the case of an optical disc that is a multilayer recording medium having at least two recording layers and capable of recording information on each recording layer, recording can be performed by moving the objective lens from the focal position of the objective lens. It is conceivable that the effect of laser light emission will occur on a recording layer different from the recording layer to be attempted.

  An object of the present invention is to record not only recording power but also defocus amount when recording information on an optical disc, which is a multilayer recording medium having a plurality of recording layers, with good recording jitter and the like. Is to be able to.

According to the first aspect of the present invention, there is provided an OPC means for performing an OPC for determining an optimum recording power for information recording performed by irradiating the optical disc with light, and the light is applied to the optical disc with the optimum recording power of the recording. Test light means for test writing to the optical disc while changing the focus position of the focusing objective lens, and parameter determination means for determining an optimum focus offset amount parameter of the objective lens from the result of the test light. And the parameter determination means is different from the test light when the optical disc is a multilayer recording medium having a plurality of recording layers in order to determine the optimum value of the focus offset amount of the objective lens. limiting the defocus amount by reproducing the recording layer was subjected to re-test write By reproducing the serial recording layer, it determines the amount of change in the focus direction to be the parameter, characterized in that.

The invention according to claim 2, in the optical disk apparatus according to claim 1, wherein the parameter determining means determines, when the optical disc is a multilayer recording medium having a plurality of recording layers, not performing the test write For reproduction of the recording layer, when the recording layer that has not been subjected to the test write is the recording layer that has already been recorded, the characteristics of the reproduction signal are examined by obtaining synchronization of the reproduction signal from the already recorded signal It is characterized by that.

The invention according to claim 3, in the optical disc apparatus according to claim 1, wherein the parameter determining means determines, when the optical disc is a multilayer recording medium having a plurality of recording layers, not performing the test write For reproducing the recording layer, when the recording layer not subjected to the test write is an unrecorded recording layer, the amplitude level of the analog reproduction signal is measured, and a defocus amount that is equal to or lower than a predetermined level is used. It is characterized by that.
According to a fourth aspect of the present invention, in the optical disc apparatus according to any one of the first to third aspects, the apparatus is an optical disc recording apparatus.
According to a fifth aspect of the present invention, in the optical disk apparatus according to any one of the first to third aspects, the apparatus is an optical disk inspection apparatus.

According to a sixth aspect of the present invention, there is provided a step of performing an OPC for determining an optimum recording power for information recording performed by irradiating the optical disc with light, and collecting the light on the optical disc with the optimum recording power of the recording. A test write to the optical disc while changing the focus position of the objective lens to illuminate, and a step of determining an optimum focus offset amount parameter of the objective lens from a result of the test light, The step of determining a parameter is different in that the test light is not performed when the optical disc is a multilayer recording medium having a plurality of recording layers in order to determine the optimum value of the focus offset amount of the objective lens. limiting the defocus amount by reproducing the recording layer, reproducing the recording layer was subjected to re-test write And by determining the amount of change in the focus direction to be the parameter, characterized in that.

The invention according to claim 7 is the parameter determination method according to claim 6 , wherein the step of determining the parameter includes the test light when the optical disc is a multilayer recording medium having a plurality of recording layers. For reproduction of the recording layer that has not been performed, when the recording layer that has not been subjected to the test write is the recording layer that has already been recorded, the synchronization of the reproduction signal is obtained from the signal that has already been recorded. It is characterized by examining characteristics.

According to an eighth aspect of the present invention, in the parameter determination method according to the sixth aspect of the present invention, in the parameter determining step, the test write is performed when the optical disk is a multilayer recording medium having a plurality of recording layers. For reproduction of the recording layer that is not performed, when the recording layer that is not subjected to the test write is an unrecorded recording layer, the amplitude level of the analog reproduction signal is measured, and the defocus amount is equal to or less than a predetermined level It is characterized by using.

According to a ninth aspect of the present invention, there is provided an OPC means for performing an OPC for determining an optimum recording power for recording information performed by irradiating the optical disc with light, and the light is applied to the optical disc with the optimum recording power of the recording. Test light means for test writing to the optical disk while changing the focus position of the focusing objective lens, and determination means for determining an optimum focus offset parameter of the objective lens from the result of the test light When the computer executes control to be executed by the apparatus, the parameter determining means determines that the optical disc is a multilayer recording medium having a plurality of recording layers in order to determine the optimum value of the focus offset amount of the objective lens. , defocus by reproducing the recording layer different not subjected to the test write To limit the amount, by reproducing the recording layer was subjected to re-test light, determines the amount of change in the focus direction to be the parameter, it is characterized.

According to a tenth aspect of the present invention, in the program according to the ninth aspect , the parameter determination means does not perform the test write when the optical disc is a multilayer recording medium having a plurality of recording layers. For reproduction of the recording layer, when the recording layer that has not been subjected to the test write is the recording layer that has already been recorded, the reproduction signal is synchronized with the signal that has already been recorded, and the characteristics of the reproduction signal are examined. It is characterized by that.

According to an eleventh aspect of the present invention, in the program according to the ninth aspect , the parameter determining means does not perform the test write when the optical disc is a multilayer recording medium having a plurality of recording layers. When reproducing the recording layer, when the recording layer not subjected to the test write is an unrecorded recording layer, the amplitude level of the analog reproduction signal is measured and a defocus amount equal to or lower than a predetermined level is used. It is characterized by.

The invention described in claim 12 is characterized in that the program according to any one of claims 9 to 11 is stored.

According to the first, sixth, and ninth aspects of the invention, there is no influence of the recording power on the recording layer that does not perform the recording operation when information is recorded, and the recording quality can be kept good. Even when recording is performed on a plurality of layers, the recording quality of each recording layer can be kept good.

According to the invention of claim 2,7,10, wherein, in the invention of claim 1, 6, 9, wherein, when the recording layer is not performed the recording operation is in the state of a previously recorded, does not perform the recording operation Since defocusing is performed so that the reproduction signal of the recording layer does not deteriorate and the recording quality to the recording layer is improved, the quality of the already recorded layer is kept good after the recording operation, and the recording operation is performed. The recording quality of the performed recording layer can also be improved.

According to the invention of claim 3, 8, 11, wherein, in the invention of claim 1, 6, 9, wherein, when the recording layer is not performed the recording operation is in a state of unrecorded, does not perform the recording operation recorded Since the signal is not recorded on the recording layer by the recording power and the recording quality to the recording layer is defocused, the quality of the unrecorded recording layer is kept good after the recording operation and the recording is performed. The recording quality of the recording layer on which the operation has been performed can also be improved.

  The best mode for carrying out the present invention will be described.

  FIG. 1 is a block diagram showing the overall configuration of the optical disc apparatus according to the present embodiment. As shown in FIG. 1, the optical disc apparatus 31 rotates the optical disc 1 by a spindle motor 2. The spindle motor 2 is controlled by the motor driver 3 and the servo controller 4 so that the linear velocity is constant (CLV) or the rotation speed is constant (CAV). The linear velocity can be changed in stages. The optical pickup 5 includes a semiconductor laser as a light source (not shown), a predetermined optical system, a focusing actuator, a tracking actuator, a light receiver, a position sensor, and the like, and irradiates the recording surface of the optical disc 1 with the laser light L. The predetermined optical system includes an objective lens that focuses the laser beam L on the recording surface of the optical disc 1.

  The optical pickup 5 can be moved in the sledge direction (disk radial direction) by a seek motor (not shown). These focusing actuators, tracking actuators, and seek motors are configured to position the light spot of the laser light L at a target location on the optical disk 1 by the motor driver 3 and the servo controller 4 based on signals obtained from the light receiver and the position sensor. To control.

  When reproducing data from the optical disc 1, the reproduction signal obtained by the optical pickup 5 is amplified and binarized by the read amplifier 6, and then input to the CD / DVD decoder 7 to perform processing such as deinterleaving and error correction.

  Thereafter, the data processed by the CD / DVD decoder 7 is temporarily stored in the buffer RAM 9 by the buffer manager 8 and transferred to the host side such as a PC at once by the HOST interface (I / F) 10 when the data is prepared as sector data.

  On the other hand, when data is recorded, when data transferred from the host is received by the HOST interface 10, the data is temporarily stored in the buffer RAM 9 by the buffer manager 8. Recording starts when a certain amount of data accumulates in the buffer RAM 9, but before that, the laser spot is positioned at the writing start point. The writing start point is obtained by an ATIP (Absolute Time in Pre-Groove) signal which is a wobble signal preliminarily carved on the optical disc 1 by meandering tracks (pregrooves), or by ADIP in the case of a DVD. The ATIP signal or ADIP signal is time information indicating an absolute address on the optical disc 1, and the ATIP / ADIP decoder 11 extracts the ATIP signal or ADIP signal information and detects an error of the signal to detect a detection error rate. Measure.

  The synchronization signal generated by the ATIP / ADIP decoder 11 is input to the CD / DVD encoder 12 so that data can be written at an accurate position. The data in the buffer RAM 9 is recorded on the optical disc 1 through the laser control circuit 13 as the light source drive control means and the optical pickup 5 by adding an error correction code and interleaving with the CD / DVD encoder 12.

  Such an optical disk device 31 includes a microcomputer 14 including a CPU 17, a ROM 16, and a RAM 15 for controlling the operation of each unit described above.

  The optical disc device 31 determines an optimum recording power value by power calibration processing in the power calibration area of the optical disc 1 where information is to be recorded based on the control of the CPU 17, and the optimum recording power is recorded when information is recorded. A recording operation is performed based on the power value.

  FIG. 2 is an explanatory diagram of the format of the recording surface of the optical disc 1, particularly the CD-R / RW. The recording surface of the optical disc 1 includes a data area 18 and a power calibration area (PCA) 19 for trial writing when an optimum recording power value is obtained in the inner periphery. The PCA 19 is composed of a test area 20 and a count area 21. The test area is composed of 100 partitions, and each partition is composed of 15 frames. In general OPC operation, one of the partitions is used in one OPC operation, and testing is performed with at least two laser powers for 15 frames included in each of these partitions. Recording (symbol 22) and reproducing the test signal in each frame, comparing the characteristic value of this reproduced signal (this characteristic value is hereinafter referred to as β) and the target value, and the two coincided The stage laser power is detected as the optimum power.

  However, there are various parameters that affect the recording quality when information is recorded on the optical disc 1, and in particular, defocusing in which the objective lens that focuses the laser beam on the optical disc 1 with the optical pickup 5 is shifted in the focusing direction is the recording quality. May have a significant impact on For example, as shown in the graph showing the relationship between the jitter (Jitter) and the focus (Focus) position in FIG. 3, the jitter, which is one of the parameters representing the recording quality after data is recorded on the optical disc 1, When the recording layer is a multilayer recording medium having a multilayer structure of two layers or more, the recording layer of the optical disc 1 may be optimal at a position slightly shifted from the in-focus position.

  An example of processing for determining the optimum focus position executed by the optical disc apparatus 31 will be described with reference to the flowchart of FIG. First, before attempting to record information, the CPU 17 performs OPC to determine the optimum recording power (OPC execution means) (step S1), and the optimum recording power Pw is determined (optimum recording power determination means). (Step S2). Next, using the previously determined recording power Pw, test writing is performed on the optical disc 1 while changing the focus position (test writing means) (step S3). In order to determine the optimum focus offset amount from the result of the test write, parameters are determined so that the characteristic value of the reproduced signal after recording is optimal (decision means) (step S4). In actual recording, recording is performed with the optimum recording power and the optimum focus offset amount determined as described above (step S5).

  In such processing, the characteristic value of the reproduced signal after recording is optimized in order to determine the optimum value of the focus offset amount after recording by changing the position of the objective lens with respect to the optical disc 1 in the focus direction. The parameters are determined as follows (determination means). For example, in FIG. 3, when the test write position is reproduced while defocusing as shown in the flowchart of FIG. 4 and the jitter of the reproduced signal is measured, the position slightly shifted from the in-focus position (optimum) as shown in FIG. Jitter after recording may be the best with Focus. Therefore, when information is recorded on the optical disc 1, the recording operation is performed by shifting the focus control position by adding the focus offset amount to the focus servo state at the in-focus position.

  In addition, after recording by changing the position of the objective lens with respect to the optical disc 1 in the focus direction in the above-described processing, detection of a synchronization signal during recording of information on the optical disc 1 in order to determine the optimum value of the focus change amount The parameter can be determined so that the sensitivity is optimal (decision means). For example, FIG. 5 shows an example of measuring the relationship between the focus position and the PMSN (Phase Modulation Signal Noise Ratio) generally used in DVD + R / RW as the detection sensitivity of the synchronization signal during recording. When the PMSN with respect to the defocus amount is measured during test write while defocusing after determining the optimum recording power as in the flowchart of FIG. 4 described above, the focus position is slightly shifted as shown in FIG. The PMSN that is being recorded may be the best in the recorded position (optimal focus).

  Therefore, when the information is recorded, the CPU 17 determines the defocus amount that can improve the recording quality and the PMSN, and adds the offset amount to the focus servoed state at the in-focus position. By controlling so that the recording operation is performed by shifting the control position, the recording quality can be improved and the PMSN can also be improved.

  In order to determine the optimum value of the focus offset amount after recording by changing the position of the objective lens with respect to the optical disc 1 in the focus direction in the above-described process, the optical disc 1 is a multilayer recording medium having a plurality of recording layers. In some cases, it is possible to determine the amount of change in the focus direction, which is the optimum recording parameter, by reproducing a different recording layer that has not been subjected to OPC (decision means). For example, FIG. 6 shows an optimum recording parameter determination procedure when information is recorded on the optical disc 1. First, the CPU 17 performs OPC for determining the optimum recording power (OPC means) (step S6) and decides the optimum recording power Pw (optimum recording power decision means) (step S7). Next, using the previously determined recording power Pw, test writing is performed while changing the focus position (test write means) (step S8). At this time, if the optical disc 1 on which information is to be recorded is the above-described multilayer recording medium having two or more recording layers (Y in step S9), a recording layer different from the recording layer on which the test write was performed. Then, by turning on the focus servo and measuring the reproduction signal of the recording layer (step S10), the defocus amount that does not adversely affect other layers is limited as the limit defocus amount. Again, the optimum recording defocus amount is determined by determining on-focus on the recording layer on which the test write has been performed, and measuring and evaluating the reproduction signal (determination means) (step S11). In actual recording, recording is performed with the optimum recording power and the optimum focus offset amount determined as described above (step S12).

  Next, another example of processing executed by the optical disc apparatus 31 will be described based on the flowchart of FIG. FIG. 7 shows a procedure for determining the optimum recording parameter when information is to be recorded on the optical disc 1. First, the CPU 17 performs OPC for determining the optimum recording power (OPC means) (step S13) and decides the optimum recording power Pw (optimum recording power decision means) (step S14). Next, using the previously determined recording power Pw, test writing is performed while changing the focus position (test write means) (step S15). At this time, if the optical disk on which information is to be recorded is a multilayer recording medium having two or more recording layers (Y in step S16), the focus is set to a recording layer different from the recording layer on which the test write is performed. The servo is turned on to determine whether or not the recording layer has already been recorded (step S17). If the recording layer has already been recorded (Y in step S17), the reproduction signal at the same position as the position of the optical disc 1 where the test write was performed is synchronized with the reproduction signal of the recorded recording layer. Signal quality is measured (decision means) (step S18). It is desirable that this signal quality does not deteriorate.

  Next, when the recording layer has not been recorded (N in step S17), the analog signal amplitude of the reproduction signal is evaluated (determining means) (step S19). As this signal amplitude, it is desired that no signal amplitude is generated. From the evaluation of these reproduction signals, a defocus amount that does not adversely affect other recording layers is limited as a limit defocus amount. Again, the optimum recording defocus amount is determined by determining on-focus on the recording layer on which the test write has been performed, and measuring and evaluating the reproduction signal (decision means) (step S20). In actual recording, recording is performed with the optimum recording power determined as described above and the optimum focus offset amount (step S21).

  The optimization of the shift amount in the focus direction of the objective lens of the optical pickup 5 is not performed following the OPC operation immediately before recording information on the optical disc 1 as described above, but in advance. It is performed in the manufacturing process, the inspection process, etc., stored in the ROM area of the optical disk 1, and the value is read out during actual recording so that the optimum defocus amount is detected and controlled. Good.

  The present invention is applicable not only to the CD-R / RW and DVD + R / RW mentioned above, but also to other types of optical disks such as DVD-RAM, DVD-R / RW, Blu-Ray Disc, and HD DVD. can do.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an overall configuration of an optical disc apparatus that is the best mode for carrying out the present invention. It is explanatory drawing of the format of the recording surface of an optical disk, especially CD-R / RW. It is a graph which shows the relationship between a jitter and a focus position. 10 is a flowchart illustrating an example of processing for determining an optimum focus position executed by the optical disc apparatus. It is a graph which shows an example which measured the relationship between PMSN generally used in DVD + R / RW, and a focus position as a detection sensitivity of the synchronizing signal in recording. 12 is a flowchart illustrating another example of processing for determining an optimum focus position executed by the optical disc apparatus. 12 is a flowchart illustrating another example of processing for determining an optimum focus position executed by the optical disc apparatus.

Explanation of symbols

1 Optical disk 31 Optical disk device

Claims (12)

OPC means for performing OPC to determine the optimum recording power for recording information performed by irradiating the optical disc with light;
Test light means for test writing to the optical disc while changing the focus position of the objective lens for condensing the light on the optical disc with the optimum recording power of the recording, and the optimum focus of the objective lens from the result of the test light Parameter determining means for determining the parameter of the offset amount;
With
The parameter determining means determines the optimum value of the focus offset amount of the objective lens when the optical disc is a multi-layer recording medium having a plurality of recording layers, and the different recording without performing the test write. An optical disc apparatus characterized in that a defocus amount is limited by reproducing a layer, and a change amount in a focus direction as the parameter is determined by reproducing the recording layer on which test writing has been performed again .   When the optical disc is a multi-layer recording medium having a plurality of recording layers, the recording layer not performing the test write is used for reproducing the recording layer not performing the test write. 2. The optical disc apparatus according to claim 1, wherein when the recording layer is already recorded, the characteristics of the reproduction signal are examined by obtaining synchronization of the reproduction signal from the already recorded signal.   When the optical disc is a multi-layer recording medium having a plurality of recording layers, the recording layer not performing the test write is used for reproducing the recording layer not performing the test write. 2. The optical disc apparatus according to claim 1, wherein when the recording layer is an unrecorded layer, the amplitude level of the analog reproduction signal is measured and a defocus amount that is equal to or less than a predetermined level is used.   The optical disk apparatus according to claim 1, wherein the apparatus is an optical disk recording apparatus.   The optical disk apparatus according to claim 1, wherein the apparatus is an optical disk inspection apparatus. Performing OPC to determine the optimum recording power for recording information performed by irradiating the optical disc with light; and
Test writing to the optical disc while shifting the focus position of an objective lens that focuses the light on the optical disc with the optimum recording power of the recording;
Determining an optimum focus offset parameter of the objective lens from the result of the test light;
Comprising
The step of determining the parameter differs in that the test light is not performed when the optical disc is a multilayer recording medium having a plurality of recording layers in order to determine the optimum value of the focus offset amount of the objective lens. The parameter determination is characterized in that the defocus amount is limited by reproducing the recording layer, and the amount of change in the focus direction as the parameter is determined by reproducing the recording layer on which the test write has been performed again. Method.   In the step of determining the parameter, when the optical disc is a multi-layer recording medium having a plurality of recording layers, the recording layer that is not subjected to the test write is not reproduced for reproduction of the recording layer that is not subjected to the test write. 7. The parameter determination method according to claim 6, wherein when the layer is the recording layer already recorded, the reproduction signal characteristics are examined by obtaining the synchronization of the reproduction signal from the already recorded signal.   In the step of determining the parameter, when the optical disc is a multi-layer recording medium having a plurality of recording layers, the recording layer that is not subjected to the test write is not reproduced for reproduction of the recording layer that is not subjected to the test write. 7. The parameter determining method according to claim 6, wherein when the layer is an unrecorded recording layer, the amplitude level of the analog reproduction signal is measured and a defocus amount equal to or less than a predetermined level is used. OPC means for performing OPC to determine the optimum recording power for recording information performed by irradiating the optical disc with light;
Test write means for test writing to the optical disc while changing the focus position of an objective lens that focuses the light on the optical disc with the optimum recording power of the recording;
Determining means for determining an optimum focus offset parameter of the objective lens from the result of the test light;
Control that causes the optical disc apparatus to execute
The parameter determining means determines the optimum value of the focus offset amount of the objective lens when the optical disc is a multi-layer recording medium having a plurality of recording layers, and the different recording without performing the test write. A program characterized in that a defocus amount is limited by reproducing a layer, and a change amount of the focus direction as the parameter is determined by reproducing the recording layer on which test writing has been performed again .   When the optical disc is a multi-layer recording medium having a plurality of recording layers, the recording layer not performing the test write is used for reproducing the recording layer not performing the test write. 10. The program according to claim 9, wherein when the recording layer is already recorded, the characteristics of the reproduction signal are examined by obtaining synchronization of the reproduction signal from the already recorded signal.   When the optical disc is a multi-layer recording medium having a plurality of recording layers, the recording layer not performing the test write is used for reproducing the recording layer not performing the test write. 10. The program according to claim 9, wherein when the recording layer is an unrecorded layer, the amplitude level of the analog reproduction signal is measured and a defocus amount that is equal to or less than a predetermined level is used.   A storage medium characterized by storing the program according to any one of claims 9 to 11.

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