JP2006179162A6 - Information recording apparatus and method, and computer program - Google Patents

Abstract

An information recording medium, an apparatus and the like capable of recording data with a suitable recording power on a recording medium having a plurality of layers are provided.
An information recording medium comprising a first recording layer (L0 layer) for recording by irradiating a laser beam (LB) and a second recording layer (L1 layer) for recording recording information via the first recording layer. (100), recording means for recording the recording information by irradiating the laser beam, and recording the trial information by irradiating the second recording layer through the recording area where the recording information in the first recording layer is not recorded And calculating means for calculating the optimum power of the laser beam when recording information is recorded on the second recording layer via the recording area where the recording information is recorded on the first recording layer, and recording on the second recording layer. Recording means for irradiating the second recording layer with the laser light through the recording area in which the recording information in the first recording layer has been recorded, when irradiating the laser beam with the optimum power when recording information And control means for controlling.
[Selection] Figure 1

Description

  The present invention relates to an information recording apparatus and method such as a DVD recorder and a technical field of a computer program that causes a computer to function as such an information recording apparatus.

  For example, in an information recording medium such as an optical disc such as a CD-ROM (Compact Disc-Read Only Memory), a CD-R (Compact Disc-Recordable), and a DVD-ROM, a plurality of recording layers are laminated on the same substrate. Multilayer, double layer, or multiple layer type optical discs have also been developed. More specifically, the double-layer type optical disc is, as the first layer, the first layer located on the most front side (that is, the side closer to the optical pickup) when viewed from the laser beam irradiation side when recording by the information recording apparatus. It has one recording layer (referred to as “L0 layer” in this application as appropriate), and further has a transflective film located on the back side thereof (that is, the side far from the optical pickup). As the second layer, it has a second recording layer (referred to as “L1 layer” in this application as appropriate) located on the back side of the transflective film via an intermediate layer such as an adhesive layer, and further on the back side. A reflective film located on the surface. When producing such a multilayer information recording medium, the L0 layer and the L1 layer are formed separately, and finally, the two layers are bonded together, so that a two-layer type optical disc can be manufactured at low cost. Can be manufactured.

  In an information recording apparatus such as a CD recorder that records such a two-layer optical disc, the recording laser beam is focused (or irradiated) on the L0 layer, so that the L0 layer is focused on. Information is recorded by an irreversible change recording method such as heating, irreversible change recording method or rewritable method, and the laser beam is focused on the L1 layer, thereby heating the information on the L1 layer. Recording is performed by an irreversible change recording method such as irreversible change recording heating or a rewritable method.

  On the other hand, in an information recording / reproducing apparatus for recording an information recording medium such as an optical disk, the optimum recording power is obtained by OPC (Optimum Power Calibration) processing according to the type of optical disk, the type of information recording / reproducing apparatus, the recording speed, etc. Power is set. That is, recording power calibration is performed. Thereby, an appropriate recording operation in the optical disc can be realized. For example, when an optical disc is loaded and a write command is input, the light intensity is sequentially switched and data for trial writing is recorded in the OPC area, so-called trial writing processing is executed. Thereafter, the trial writing data recorded in this manner is reproduced, and the reproduction result is determined based on a predetermined evaluation criterion, and the optimum power is set (Patent Document 1). The optimum power can also be set by OPC (so-called running OPC) performed simultaneously with the actual recording operation.

Japanese Patent No. 3159454

  In such a two-layer type optical disc, the recording condition of the recording layer on the back side (for example, the L1 layer) when viewed from the laser light irradiation side is the recording layer on the front side when viewed from the laser light irradiation side. It depends on the state (for example, L0 layer). In other words, depending on the recording state of the L0 layer, there is a technical problem that the optimum power for recording data on the L1 layer varies. This also leads to the fact that data cannot be properly recorded in the L1 layer. Therefore, in order to perform OPC on a two-layer type optical disc, it is necessary to consider such a difference in recording conditions. However, according to the OPC in the background art described above, such a difference in recording conditions is not taken into consideration. Therefore, there is a technical problem that it is difficult or impossible to obtain a truly optimum recording power for each recording layer of the two-layer type optical disc.

  The present invention has been made in view of the above-described conventional problems, for example, information that makes it possible to record data with an appropriate recording power even in an information recording medium having a plurality of recording layers. It is an object to provide a recording medium, an information recording apparatus and method, and a computer program.

  In order to solve the above-described problems, an information recording apparatus of the present invention includes an information recording apparatus including a first recording layer on which recording information is recorded, and a second recording layer on which the recording information is recorded via the first recording layer. Recording means for recording the recording information by irradiating a medium with laser light having a variable recording power, and using the recording means, the recording information in the first recording layer passes through an unrecorded recording area. Test information for test recording is recorded by irradiating the second recording layer with the laser beam, and the recording information in the first recording layer is recorded on the second recording layer via a recorded recording area. A calculation unit that calculates an optimum power of the laser beam when the recording information is recorded by irradiating the laser beam; and an optimum unit that is calculated by the calculation unit when the recording information is recorded on the second recording layer. Illuminates the laser beam with power And control means for controlling the recording device to.

  In order to solve the above problems, an information recording method of the present invention includes an information recording medium including a first recording layer on which recording information is recorded and a second recording layer on which the recording information is recorded via the first recording layer. An information recording method in an information recording apparatus comprising recording means for recording the recording information by irradiating a recording medium with laser light having a variable recording power, wherein the recording means is used to record the information in the first recording layer. Test information for test recording is recorded by irradiating the second recording layer with the laser light through a recording area in which the recording information is not recorded, and the recording information in the first recording layer is recorded. A calculation step of calculating an optimum power of the laser beam when the recording information is recorded by irradiating the second recording layer with the laser beam through a recording area; and recording the recording information on the second recording layer When asked The recording is performed so that the laser beam is irradiated with the optimum power and the second recording layer is irradiated through the recording area in which the recording information in the first recording layer is recorded. And a control step for controlling the means.

  In order to solve the above problems, a computer program of the present invention is a computer program for recording control for controlling a computer provided in the information recording apparatus of the present invention described above. It functions as at least a part of the calculation means and the control means.

  The operation and gain of the present invention will be clarified from the best mode for carrying out the invention described below.

  Hereinafter, an information recording medium, an information recording apparatus and method, and a computer program according to an embodiment of the present invention as the best mode for carrying out the invention will be described in order.

(Embodiment of information recording apparatus)
An embodiment of the information recording apparatus of the present invention provides an information recording medium comprising a first recording layer on which recording information is recorded and a second recording layer for recording the recording information via the first recording layer. Recording means for recording the recording information by irradiating a laser beam with a variable recording power, and using the recording means, the recording information in the first recording layer passes through the recording area in which the recording information is not recorded. Test information for test recording is recorded by irradiating the two recording layers with the laser light, and the laser light is applied to the second recording layer through a recording area in which the recording information in the first recording layer is recorded. And calculating means for calculating the optimum power of the laser light when recording the recording information, and the laser light with the obtained optimum power when recording the recording information on the second recording layer. To irradiate and As the record information in the first recording layer is irradiated with the laser light to the second recording layer through the recording area is already recorded, and a control means for controlling said recording means.

  According to the embodiment of the information recording apparatus of the present invention, various types of recording information can be recorded in each of a plurality of recording layers (that is, the first recording layer and the second recording layer). For example, by irradiating the first recording layer with laser light, recording information can be recorded on the first recording layer, and on the other hand, by irradiating the second recording layer with laser light through the first recording layer. Recording information can be recorded on the second recording layer. In this case, when viewed from the laser light irradiation side, the second recording layer is on the back side (that is, the far side) than the first recording layer. More specifically, the trial information is recorded by the recording means controlled by the calculating means, and the reproduction quality is measured by reproducing the trial information by the operation of the calculating means, and the recording information is recorded on the first recording layer. The optimum power for recording is calculated. The optimum power calculated at this time particularly corresponds to the optimum power when recording information is recorded on the second recording layer via the first recording layer on which the recording information has been recorded. Then, the recording unit is controlled by the operation of the control unit, so that the recording information is recorded with the optimum power calculated by the calculating unit.

  Particularly in the present embodiment, the trial information is recorded by irradiating the second recording layer with laser light through the first recording layer in which the recording information is not recorded. For this reason, it is possible to avoid the disadvantage that the optimum power calculated according to the recording state of the first recording layer varies. That is, it is possible to calculate an appropriate optimum power. In addition, the recording information is recorded by irradiating the second recording layer with the laser light through the first recording layer on which the recording information has been recorded. For this reason, it is possible to avoid the disadvantage that the quality of the recorded information recorded in accordance with the recording state of the first recording layer varies. As a result, there is a great advantage that recording information can be appropriately recorded on the second recording layer regardless of the recording state of the first recording layer.

  As a result, according to the embodiment of the information recording apparatus of the present invention, that is, it is possible to calculate the optimum recording power of each recording layer for an information recording medium having a plurality of recording layers, relatively easily. As a result, the recording information can be recorded with an appropriate recording power.

  In one aspect of the embodiment of the information recording apparatus of the present invention, the calculating means calculates the optimum power by correcting correlation information indicating a correlation between the reproduction quality of the trial information and the recording power.

  According to this aspect, by correcting the correlation information, it is possible to compensate for a difference in recording conditions when the trial information is recorded and a difference (or deviation) in recording conditions when the recording information is recorded. Become. Accordingly, it is possible to record the recording information with an appropriate recording power, particularly on the second recording layer.

  In the aspect of the information recording apparatus that corrects the correlation information as described above, the calculation means includes the characteristics of the laser beam irradiated with the recording information in the first recording layer through an unrecorded recording area, and the first information. The correlation information is corrected based on a difference from the characteristics of the laser beam irradiated through the recording area in which the recording information in the recording layer is already recorded.

  If comprised in this way, correlation information can be correct | amended appropriately based on the characteristic of the laser beam according to the recording state of the 1st recording layer.

  In the aspect of the information recording apparatus for correcting the correlation information as described above, the first recording layer has the laser light transmittance reduced by recording the recording information, and the calculation means calculates the calculation. The correlation information is corrected so that the optimum power is larger than the optimum power indicated by the correlation information before correction.

  If comprised in this way, correlation information can be correct | amended appropriately according to the characteristic of a 1st recording layer. That is, it is considered that the recording power of the laser beam irradiated through the first recording layer is reduced because the transmittance of the first recording layer is reduced by recording the recording information. Therefore, if the recording power is increased accordingly, the recording information can be recorded appropriately.

  In the aspect of the information recording apparatus for correcting the correlation information as described above, the first recording layer increases the transmittance of the laser beam by recording the recording information, and the calculation means calculates the calculation. The correlation information is corrected so that the optimum power is smaller than the optimum power indicated by the correlation information before correction.

  If comprised in this way, correlation information can be correct | amended appropriately according to the characteristic of a 1st recording layer. That is, it is considered that the recording power of the laser beam irradiated through the first recording layer is increased because the transmittance of the first recording layer is increased by recording the recording information. Accordingly, if the recording power is reduced accordingly, the recording information can be recorded appropriately.

  In another aspect of the embodiment of the information recording apparatus of the present invention, the control means irradiates the laser beam having a predetermined waveform different from the waveform of the laser beam for recording the trial information. Control the recording means.

  According to this aspect, by correcting the correlation information, it is possible to compensate for a difference in recording conditions when the trial information is recorded and a difference (or deviation) in recording conditions when the recording information is recorded. Become. Accordingly, it is possible to record the recording information with an appropriate recording power, particularly on the second recording layer. That is, since it is sufficient to adjust the waveform of the laser beam, it is possible to record the record information with an appropriate recording power relatively easily.

  In the aspect of the information recording apparatus that corrects the correlation information as described above, the calculation means includes the characteristics of the laser beam irradiated with the recording information in the first recording layer through an unrecorded recording area, and the first information. The recording means is configured to irradiate the laser light having the different predetermined waveform based on a difference from the characteristics of the laser light irradiated through the recording area in which the recording information in the recording layer is recorded. Control.

  If comprised in this way, correlation information can be correct | amended appropriately based on the characteristic of the laser beam according to the recording state of the 1st recording layer.

  In the aspect of the information recording apparatus for irradiating laser beams having different waveforms as described above, the waveform of the laser beam includes a combination of a short pulse and a long pulse, and the control means records the trial information. Therefore, the recording means is controlled so that the short pulse in the predetermined waveform becomes longer or shorter on the time axis than the waveform of the laser beam.

  If comprised in this way, the waveform of a laser beam can be changed comparatively easily. Since the increase or decrease of the recording power can be adjusted depending on the length of the waveform, the recording information can be recorded with an appropriate recording power relatively easily.

  In an aspect of the information recording apparatus that irradiates laser light having different waveforms as described above, the control means is configured such that the short pulse in the predetermined waveform is 5 than the waveform of the laser light for recording the trial information. The recording means is controlled so as to become longer or shorter by a ratio of not less than% and not more than 10%.

  If comprised in this way, the waveform of a laser beam can be changed appropriately according to the recording state of a 1st recording layer.

(Embodiment of information recording method)
Embodiments according to the information recording method of the present invention irradiate the laser light through the first recording layer and the first recording layer for recording information by irradiating the laser light with variable recording power. An information recording method in an information recording apparatus comprising recording means for recording the recording information by irradiating the laser beam onto an information recording medium comprising a second recording layer for recording the recording information. , By using the recording means, the test information for test recording is recorded by irradiating the second recording layer with the laser light through a recording area where the recording information in the first recording layer is not recorded. Calculation for calculating an optimum power of the laser beam when the recording information is recorded by irradiating the second recording layer with the laser beam through a recording area in which the recording information in the first recording layer is recorded Process, When recording the recording information on the second recording layer, the recording information is recorded on the first recording layer so as to irradiate the laser beam with the obtained optimum power. According to an embodiment of the information recording method of the present invention, the information recording apparatus of the present invention described above is provided. The control step of controlling the recording means to irradiate the second recording layer with the laser light Various benefits similar to those of the embodiment can be enjoyed.

  Incidentally, in response to the various aspects of the embodiment of the information recording apparatus of the present invention described above, the embodiment of the information recording method of the present invention can also adopt various aspects.

(Embodiment of computer program)
An embodiment according to the computer program of the present invention is a computer program for recording control for controlling a computer provided in the above-described embodiment of the information recording apparatus of the present invention (including various aspects thereof), The computer is caused to function as at least part of the recording unit, the calculating unit, and the control unit.

  According to the embodiment of the computer program according to the present invention, the computer program is read from a recording medium such as a ROM, a CD-ROM, a DVD-ROM, and a hard disk that stores the computer program, and is executed. If the computer program is downloaded to a computer via communication means and then executed, the above-described embodiment of the information recording apparatus of the present invention can be realized relatively easily.

  Incidentally, in response to the various aspects of the embodiment of the information recording apparatus of the present invention described above, the embodiment of the computer program of the present invention can also adopt various aspects.

  In order to solve the above problems, a computer program product in a computer-readable medium clearly embodies program instructions executable by a computer provided in the information recording apparatus (including various aspects thereof) of the present invention. The computer is caused to function as at least part of the recording unit, the calculating unit, and the control unit.

  According to the computer program product of the present invention, when the computer program product is read into a computer from a recording medium such as a ROM, CD-ROM, DVD-ROM, or hard disk storing the computer program product, or, for example, by a transmission wave. If a computer program product is downloaded to a computer via communication means, at least a part of the recording means, calculation means, and control means of the present invention described above can be implemented relatively easily. More specifically, the computer program product includes computer-readable code (or computer-readable instructions) that functions as at least part of the recording unit, the calculation unit, and the control unit of the present invention described above. May be.

  Such an operation and other advantages of the present invention will become apparent from the embodiments described below.

  As described above, the embodiment according to the information recording apparatus and method of the present invention includes a recording unit, a calculation unit and a control unit, or a calculation step and a control step. Therefore, the optimum power can be calculated appropriately even for an information recording medium having a plurality of recording layers.

  Embodiments of the present invention will be described below with reference to the drawings.

  First, with reference to FIG. 1, description will be given on an information recording medium that is a target of a recording operation of an embodiment of the information recording apparatus of the present invention. FIG. 1A is a schematic plan view showing the basic structure of an optical disc having a plurality of recording areas as information recording media to be subjected to a recording operation of the embodiment of the information recording apparatus of the present invention. FIG. 1B is a schematic cross-sectional view of the optical disc and a schematic conceptual diagram of the recording area structure in the radial direction associated therewith.

  As shown in FIG. 1A and FIG. 1B, an optical disc 100 is a lead according to the present embodiment centered on a center hole 101 on a recording surface on a disc body having a diameter of about 12 cm, for example. An in area 102, a data recording area 105, and a lead out area 108 or a middle area 109 are provided. A recording layer or the like is laminated on the transparent substrate 200 of the optical disc 100, for example. In each recording area of the recording layer, for example, tracks such as a groove track and a land track are alternately provided in a spiral shape or a concentric shape around the center hole 101. On this track, data is divided and recorded in units of ECC blocks. The ECC block is a data management unit based on a preformat address in which recorded information can be error-corrected.

  In the lead-in area 102 of the L1 layer, a PCA (Power Calibration Area) 120 in which an OPC pattern described later is recorded is provided. This PCA 120 is used particularly when calculating the optimum recording laser power of the L1 layer. Of course, a PCA used for calculating the optimum recording laser power of the L0 layer may also be provided in the lead-in area 102 of the L0 layer. The PCA 120 is not limited to being provided in the lead-in area 102 but may be provided in another area.

  The present invention is not particularly limited to an optical disc having such three areas. For example, even if the lead-in area 102, the lead-out area 108, or the middle area 109 does not exist, a data structure described below can be constructed. Further, as will be described later, the lead-in area 102, the lead-out area 108, or the middle area 109 may be further subdivided.

  In particular, as shown in FIG. 1B, the optical disc 100 according to the present embodiment includes, for example, a L0 layer that constitutes an example of first and second recording layers according to the present invention, which will be described later, on a transparent substrate. The L1 layer is laminated. During recording / reproduction of such a two-layer optical disc 100, depending on which recording layer the focusing position of the laser beam LB irradiated from the upper side to the lower side in FIG. Recording / reproduction is performed in the L0 layer or recording / reproduction is performed in the L1 layer.

  Further, the optical disc 100 according to the present embodiment is not limited to the two-layer single side, that is, the dual layer, but may be the two-layer double side, that is, the dual layer double side. Further, the optical disc is not limited to the optical disc having two recording layers as described above, and may be a multilayer optical disc having three or more layers. Also, an opposite track path method in a two-layer type optical disk or a parallel track path method may be used.

(Example of information recording apparatus)
Next, with reference to FIG. 2 to FIG. 7, an explanation will be given on an embodiment according to the information recording apparatus of the present invention.

(1) Basic Configuration First, the basic configuration of the information recording apparatus according to the present embodiment will be described with reference to FIG. FIG. 2 is a block diagram conceptually showing the basic structure of the information recording apparatus in the example.

  As shown in FIG. 2, the information recording apparatus 300 is an apparatus that records information on the optical disc 100 and reads information recorded on the optical disc 100 under the control of the processor 354.

  The information recording apparatus 300 includes an optical disc 100, a spindle motor 351, an optical pickup 352, a signal recording / reproducing means 353, a CPU (drive control means) 354, a memory 355, a data input / output means 356, an LD driver 358, an OPC pattern generator 359, And a bus 357.

  The spindle motor 351 rotates and stops the optical disc 100, and operates when accessing the optical disc. More specifically, the spindle motor 351 is configured to rotate and stop the optical disc 100 at a predetermined speed while receiving spindle servo from a not-shown servo unit or the like.

  The optical pickup 352 is a specific example of the “recording unit” in the present invention, and performs recording / reproduction with respect to the optical disc 100, and includes a laser device and a lens. More specifically, the optical pickup 352 irradiates the optical disc 100 with a light beam such as a laser beam at the first power as the reading light during reproduction and modulates the optical power with the second power as the writing light at the time of recording. Irradiate.

  The signal recording / reproducing unit 353 controls the spindle motor 351 and the optical pickup 352 to perform recording / reproduction with respect to the optical disc 100.

  The CPU (drive control means) 354 is a specific example of the “control means” in the present invention, and is connected to the signal recording / reproducing means 353 and the memory 355 via the bus 357 to instruct each control means. Thus, the entire information recording apparatus 300 is controlled. Normally, software for operating the CPU 354 is stored in the memory 355.

  The memory 355 is used in general data processing in the disk drive 300, such as a buffer area for recording / reproducing data and an area used as an intermediate buffer for conversion to data usable by the signal recording / reproducing means 353. The memory 355 includes a ROM area in which a program for performing operations as these recorder devices is stored, a buffer used for compressing / decompressing video data, and a RAM area in which variables necessary for the program operation are stored. .

  Particularly in the present embodiment, the memory 355 includes a semiconductor memory such as a ROM, a RAM, a flash memory, and the like, and the above-described calculation information 120 may be recorded thereon. However, when the calculated information 120 is recorded on the optical disc 100, the calculated information may not be recorded in the memory 355.

  The data input / output control unit 356 inputs data to be recorded on the optical disc 100 from, for example, an external device. Then, the data input / output unit 356 outputs the input data to the signal recording / reproducing unit 353 via the bus 357. When data recorded on the optical disc 100 can be reproduced, the data input / output unit 356 may be configured to output the reproduced data to an external output device such as a liquid crystal display.

  The OPC pattern generator 359 is a specific example of “calculation means” in the present invention, and generates a predetermined OPC pattern that is a specific example of “trial information” in the present invention, using various strategies described later. Used for.

  The LD driver 358 controls a laser beam emitted from the optical pickup 352 by oscillating a laser diode or the like of the optical pickup 352 at a predetermined frequency.

  The information recording apparatus 300 according to the present embodiment described with reference to FIG. 2 also serves as an embodiment of the information recording / reproducing apparatus. That is, recorded information can be reproduced via a signal recording / reproducing means 353 (for example, a head amplifier, an RF detector, etc.), and this embodiment includes the function of an information reproducing apparatus or the function of an information recording / reproducing apparatus.

(2) First Operation Example Next, a first operation example of the information recording apparatus 300 according to the present embodiment will be described with reference to FIGS. 3 to 6. In the first operation example, the data recording operation on the L1 layer will be specifically described.

  First, the overall flow of the first operation example of the information recording apparatus 300 according to the present embodiment will be described with reference to FIGS. FIG. 3 is a flowchart conceptually showing a flow of the first operation example, and FIG. 4 is a cross-sectional view conceptually showing an OPC pattern recording and data recording operation on the L1 layer.

  As shown in FIG. 3, first, the optical disc 100 is loaded (step S101). At this time, a seek operation is performed by the optical pickup 352 under the control of the CPU 354, and various management data necessary for the recording process on the optical disc 100 is acquired. Based on the management data, under the control of the CPU 354, for example, data is recorded on the optical disc 100 via the interface in accordance with an instruction from an external input device or the like.

  Subsequently, an OPC process is performed to calculate the optimum recording laser power when data is recorded on the L1 layer. Specifically, first, a predetermined OPC pattern is recorded on the PCA provided in the lead-in area 102 (step S102).

  Particularly in this embodiment, as shown in FIG. 4A, when the OPC pattern is recorded on the PCA 120 of the L1 layer, the laser beam LB is irradiated through the L0 layer where data is not recorded. On the other hand, when data is recorded on the L1 layer (particularly, the data recording area 105), as shown in FIG. 4B, laser light is irradiated through the L0 layer on which the data has been recorded.

  Here, the recording of the OPC pattern will be specifically described with reference to FIG. FIG. 5 is a schematic timing chart showing one OPC process in the case of 16 power steps.

  As shown in FIG. 5, first, under the control of the CPU 354, the optical pickup 352 is moved to the PCA 120 provided in the lead-in area 102 of the L1 layer. Then, the operation of the OPC pattern generator 359 and the LD driver 358 sequentially switches the recording laser power step by step (for example, 16 steps different from each other), and the OPC pattern is recorded on the PCA 120. Specifically, an OPC pattern as shown in FIG. 5 is recorded. For example, a recording pattern in which short pits (marks) corresponding to 2T pulses and long pits (marks) corresponding to 8T pulses are alternately formed with no-recording sections (spaces) having the same length can be given as an example.

  The LD driver 358 drives the semiconductor laser in the optical pickup 352 so as to sequentially switch the recording laser power in accordance with the OPC pattern output from the OPC pattern generator 359.

  In FIG. 3 again, subsequently, asymmetry which is the reproduction quality of the OPC pattern recorded in step S102 is measured (step S103). Specifically, the OPC pattern written by trial on the PCA 120 is reproduced under the control of the CPU 354. Then, the peak value and the bottom value of the envelope detection of the RF signal are sampled from the RF signal that is a reproduction signal input to the envelope detector (not shown). Then, asymmetry is calculated from the peak value and the bottom value. Such OPC pattern reproduction and asymmetry measurement are performed in one OPC process according to, for example, the number of recorded OPC patterns.

  Subsequently, correlation information indicating the correlation between the recording laser power and the asymmetry is created (step S104). Specifically, the correlation information is created by sampling the asymmetry value of the OPC pattern recorded for each recording laser power switched to 16 levels and calculating the correspondence with the recording laser power. Then, correction processing corresponding to the recording characteristics of the L1 layer is performed on the obtained correlation information (step S105). The correlation information correction process will be described later in detail (see FIG. 6). Then, based on the corrected correlation information, the optimum recording laser power for recording data on the L1 layer is calculated (step S106). For example, the optimum recording laser power is calculated so that the asymmetry is near the minimum, for example.

  Thereafter, a data recording operation is performed with the optimum recording laser power obtained in step S106 (step S107). Then, it is determined whether or not to end the recording operation (step S108).

  As a result of this determination, if it is determined not to end the recording operation (No at Step S108), the process returns to Step S107 and the recording operation is continued. On the other hand, when it is determined that the recording operation is to be ended (step S108: Yes), the recording operation is ended. At this time, for example, finalization processing or the like may be performed, or the optical disc 100 that has finished the recording operation may be ejected.

  Next, the correlation information correction process in step S105 of FIG. 3 will be described in detail with reference to FIG. FIG. 6 is a graph conceptually showing the correlation information indicating the correlation between the recording laser power and the asymmetry and the correction process of the correlation information.

  As shown in FIG. 6A, the correlation information obtained by OPC is shown by a graph indicated by a thick line. This correlation information is obtained by OPC performed by irradiating the laser beam LB through the L0 layer in which no data is recorded. However, when data is actually recorded on the L1 layer, the laser beam LB is irradiated through the L0 layer on which the data has been recorded. Therefore, the optimum recording laser power obtained from the correlation information is not necessarily optimum. Cannot be said. Accordingly, the correlation information is corrected as shown in step S105 of FIG.

  Specifically, under the control of the CPU 354, the correlation information graph is moved (shifted) in parallel to the recording laser power axis and to the left side (that is, the side where the recording laser power value decreases). As a result, it is possible to obtain corrected correlation information as indicated by a chain line in FIG. This corrected correlation information is substantially equivalent to the correlation information obtained by OPC performed by irradiating the laser beam LB through the L0 layer on which the data has been recorded. For example, if the optimum recording laser power calculated from the correlation information before correction is P2, and the optimum recording laser power calculated from the correlation information after correction is P1, the correlation information is moved to satisfy the equation shown in Equation 1. It is preferable to make it.

  After correcting the correlation information in this way, the value of the recording laser power that realizes the target asymmetry value is calculated as the optimum recording laser power. For example, as shown in FIG. 6A, when the target asymmetry value is designated as “0”, the optimum recording laser power is P1. Then, the output of the laser beam LB is adjusted by the LD driver 358 under the control of the CPU 354 so that data is recorded in the L1 layer at the obtained optimum recording laser power P1. Thereby, data can be recorded stably and suitably without deteriorating the recording quality of the data. And when reproducing the data recorded in this way, the reproduction quality can be improved.

  It is assumed that data is recorded on the L1 layer with the optimum recording laser power P2 calculated from the correlation information before correction without correcting the correlation information. In this case, since the L1 layer is irradiated with laser light through the L0 layer on which data has been recorded, the correlation information reflecting the actual recording state is a graph indicated by a chain line in FIG. . According to the correlation information indicated by the chain line graph, the asymmetry of the data recorded with the recording laser power P2 is “As1”, which is a value different from “0” which is originally the target. This indicates that a recording operation that realizes a reproduction quality that is originally desired (for example, reproduction quality at which asymmetry is “0”) is not performed. However, since the optimum recording laser power is calculated after correcting the correlation information in the present embodiment, such a problem does not occur and a recording operation that realizes the originally desired reproduction quality can be performed. .

  Further, when calculating the optimum recording laser power in the L1 layer, the laser beam is irradiated through the L0 layer where data is not recorded, so that the result of OPC varies depending on the recording state of the L0 layer. Can be effectively prevented. In other words, it is possible to prevent variation in the OPC result caused by whether the laser beam is irradiated through the L0 layer where data is recorded or the laser beam is irradiated through the L1 layer where data is not recorded. Power can be calculated. The difference between the recording state of the L0 layer at the time of OPC and the recording state of the L0 layer at the time of data recording can be compensated by correcting the correlation information as described above.

  When data is recorded on the L1 layer, the laser beam LB is irradiated through the L0 layer on which the data has already been recorded. Therefore, the recording quality of the data on the L1 layer varies depending on the recording state of the L0 layer. Can be effectively prevented. Further, in the current two-layer type optical disc, a recording operation is generally performed in which data is recorded in the L1 layer on the back side after data is recorded in the L0 layer on the near side. Therefore, the information recording apparatus according to the present embodiment also has a great advantage that it can appropriately cope with this general recording operation.

  The correlation information graph is not limited to shifting to the left side, and the correlation information graph may be shifted to the right side as shown in FIG. When the correlation information is shifted to the right side, for example, when the optimum recording laser power calculated from the correlation information before correction is P2, and the optimum recording laser power calculated from the correlation information after correction is P1, Equation 2 is obtained. It is preferable to move the correlation information to the extent that the equation shown is satisfied.

  Any of these can enjoy the various benefits described above. The difference in the direction of movement of the correlation information differs depending on the type of material (for example, a dye film, a reflective film, an equivalent film, a transparent substrate, etc.) constituting the optical disc 100. For example, depending on the material constituting the optical disc 100, recording data in the L0 layer may cause the dye film constituting the L0 layer to fade, resulting in an increase in the transmittance of the L0 layer. At this time, it is considered that the intensity of the laser beam LB irradiated through the recorded L0 layer is higher than the intensity of the laser beam LB irradiated through the unrecorded L0 layer. Therefore, in this case, it is preferable to move the correlation information to the left side (that is, to the side where the recording laser power decreases). On the other hand, depending on the material constituting the optical disc 100, when data is recorded in the L0 layer, the dye film constituting the L0 layer may be carbonized, and as a result, the transmittance of the L0 layer may decrease. At this time, it is considered that the intensity of the laser beam LB irradiated through the recorded L0 layer is smaller than the intensity of the laser beam LB irradiated through the unrecorded L0 layer. Therefore, in this case, it is preferable to move the correlation information to the right side (that is, to the side where the recording laser power increases). Then, under the control of the CPU 354, it may be configured to measure or predict changes in the material, transmittance, and the like constituting the optical disc 100. For example, the laser beam LB having a predetermined power value may be irradiated in advance to measure or predict these. Then, the direction in which the correlation information is moved or the amount of movement thereof may be appropriately determined according to the measurement result or the prediction result.

  As a result, according to the information recording apparatus of the present embodiment, even in the case of a two-layer type optical disc, the recording state of the recording layer on the near side as viewed from the side irradiated with the laser beam LB (ie, L0 layer) Regardless of this, the optimum recording laser power in the recording layer (that is, the L1 layer) on the back side as viewed from the side irradiated with the laser beam LB can be suitably calculated. Specifically, more preferable asymmetry values, reflectances, modulation degrees, jitter values, and the like can be obtained as the characteristics of recorded data, and good recording sensitivity can be realized.

  When data is recorded on the L0 layer by the information recording apparatus 300 according to the present embodiment, the above-described OPC process is performed in the PCA provided in the lead-in area 102 of the L0 layer, and the optimum recording laser power is calculated. To do. Then, data is recorded on the L0 layer with the calculated optimum recording laser power. When calculating the optimum recording laser power for the L0 layer, the correlation information correction process described above may or may not be performed. However, if the recording characteristics at the time of recording data on the L0 layer change depending on whether the data is recorded on the corresponding L1 layer or not recorded, the correlation information is also obtained in the OPC processing of the L0 layer. It is preferable to perform the correction process.

  In this embodiment, a graph is used as the correlation information. However, the present invention is not limited to this, and for example, a function indicating the correlation between the recording laser power and the asymmetry value may be used as the correlation information, or the recording may be performed. It may be a table or table indicating the correlation between the laser power and the asymmetry value. Even if such correlation information is used, as described above, if the correlation information is corrected so that the optimum recording laser power becomes a suitable value, it is possible to receive the various benefits described above. Become. In this embodiment, the correlation information is corrected so that the asymmetry value of the data recorded with the optimum recording laser power is “0”, but the present invention is not limited to this. For example, in the case of a DVD as a specific example of the optical disc 100, any other value is acceptable as an asymmetry value in the standard. Accordingly, the correlation information is corrected so that an optimum recording laser power that can realize an asymmetry value other than “0” (for example, a value such as “−0.05” or “0.1”) can be appropriately calculated. You may comprise.

  In this embodiment, an asymmetry value is given as a specific example of the reproduction quality of the OPC pattern, but the present invention is not limited to this. For example, the jitter value may be used as the reproduction quality, the reproduction error rate may be used, or the reflectance of the laser beam LB may be used. Even if these various reproduction qualities are used, it is possible to receive the various benefits described above by correcting the correlation information indicating the correlation between the reproduction quality and the recording laser power as described above.

(3) Second Operation Example Next, with reference to FIGS. 7 to 11, a second operation example of the information recording apparatus 300 according to the present embodiment will be described. Note that the description of the second operation example will be made with a data recording operation on the L1 layer as a specific example.

  First, the overall flow of the second operation example will be described with reference to FIG. FIG. 7 is a flowchart conceptually showing a flow of the entire second operation example.

  As shown in FIG. 7, the second operation example also performs substantially the same operation as the first operation example. That is, an optical disk is loaded (step S101), an OPC pattern is recorded (step S102), asymmetry is measured (step S103), and correlation information is created (step S103) in order to calculate the optimum recording laser power in the L1 layer. S104).

  Especially in the second operation example, unlike the first operation example, the optimum recording laser power is calculated without correcting the correlation information (step S106). That is, from the correlation information created in step S104, the value of the recording laser power that realizes the target asymmetry value is calculated as the optimum recording laser power.

  After that, the waveform (that is, recording pulse) of the laser beam irradiated at the time of data recording is corrected (step S201). The recording pulse correction operation will be described in detail later (see FIG. 8 and the like). Then, a data recording operation is performed with the corrected laser beam LB (step S107). Then, it is determined whether or not to end the recording operation (step S108), and the process returns to step S107 to continue the recording operation or to end the recording operation.

  Next, the recording pulse correction operation in step S201 in FIG. 7 will be described with reference to FIGS. 8 and 10 are explanatory diagrams showing recording pulse waveforms before and after correction, and FIGS. 9 and 11 are correlation information and pulse waveforms showing the correlation between recording laser power and asymmetry. It is a graph which shows notionally substantial correlation information after correction | amendment.

  As shown in FIG. 8, the pulse of the laser beam LB used in the information recording apparatus 300 according to the present embodiment is configured by combining a short pulse and a long pulse. That is, a short pulse ON state, a short pulse OFF state, a long pulse ON state, and a long pulse OFF state are combined. Then, OPC is performed by the laser beam LB based on the pulse A shown in the upper part of FIG. On the other hand, when the actual data is recorded, the laser beam LB based on the pulse B shown in the lower part of FIG. Specifically, the pulse B has a shorter pulse width than the pulse A. More specifically, the duty ratio of the short pulse in the pulse B is preferably about 5% to 10% larger than the duty ratio of the short pulse in the pulse A. The information recording apparatus 300 according to the present embodiment preferably has a strategy that defines each of the pulse A and the pulse B. However, even if only one of the strategies is provided, it is sufficient if information such as a duty ratio that can limit the other pulse waveform is provided. Then, based on the strategy that defines the pulse waveform, the operation of the LD driver 358 under the control of the CPU 354 irradiates the laser beam LB based on the pulse B and records data.

  By correcting the recording pulse of the laser beam LB when recording data in this way, the following advantages can be obtained. Specifically, the correlation information obtained by OPC shown in the thick line graph in FIG. 9 is correlation information obtained by irradiating the laser beam LB through the L0 layer where data is not recorded. However, when data is actually recorded on the L1 layer, the laser beam LB is irradiated through the L0 layer on which the data has been recorded. Therefore, the optimum recording laser power obtained from the correlation information is not necessarily optimum. Cannot be said. At this time, by correcting the recording pulse of the laser beam LB, the asymmetry of the recorded data follows the correlation information as shown by the chain line graph in FIG. As described in the first operation example, the correlation information indicated by the chain line graph is substantially the same as the correlation information obtained by OPC performed by irradiating the laser beam LB through the L0 layer on which data is recorded. Are equivalent. That is, by recording data with the laser beam LB based on the optimum recording laser power P2 and pulse B obtained by OPC, data recording according to the correlation information indicated by the chain line is performed. This substantially realizes the recording operation equivalent to the case where data is recorded with the recording laser power P1 corresponding to the optimum recording laser power when the laser beam LB is irradiated through the L0 layer where the data is already recorded. can do. Therefore, also in the second operation example, it is possible to receive various benefits of the first operation example described above.

  Further, the duty ratio of the short pulse is not limited to be increased, and the duty ratio of the short pulse may be decreased as shown in FIG. For example, the duty ratio of the short pulse in the pulse B used for data recording is preferably about 5% to 10% smaller than the duty ratio of the short pulse in the pulse A used for OPC. Even if the pulse width of the laser beam LB is reduced in this way, as shown in FIG. 11, the data is not recorded according to the correlation information obtained by the OPC shown by the thick line graph, but is shown by the chain line graph. Data can be recorded according to the correlation information. The correlation information indicated by the chain line graph is substantially equivalent to the correlation information obtained by OPC performed by irradiating the laser beam LB through the L0 layer on which data has been recorded. That is, by recording data with the laser beam LB based on the optimum recording laser power P2 and pulse B obtained by OPC, data recording according to the correlation information indicated by the chain line is performed. This substantially realizes the recording operation equivalent to the case where data is recorded with the recording laser power P1 corresponding to the optimum recording laser power when the laser beam LB is irradiated through the L0 layer where the data is already recorded. can do. For this reason, it is possible to receive various benefits of the first operation example described above.

  In the above-described embodiment, a description has been given by taking a two-layer type optical disc as an example of the optical disc 100. Of course, a multi-layer type optical disc having three or more layers also enjoys the same benefits. It is possible.

  Further, in the above-described embodiments, the optical disc 100 as an example of the information recording medium and the recorder related to the optical disc 100 as an example of the information recording apparatus have been described. However, the present invention is not limited to the optical disc and the recorder. The present invention can also be applied to various information recording media compatible with high-density recording or high transfer rates and recorders thereof.

The present invention is not limited to the above-described embodiments, and can be appropriately changed without departing from the gist or concept of the invention that can be read from the claims and the entire specification, and information recording accompanying such changes is possible. The apparatus and method, and the computer program for recording control are also included in the technical scope of the present invention.
(Industrial applicability)
The information recording apparatus and method and the computer program according to the present invention can be used for, for example, a recorder for a high-density optical disk capable of recording various information with high density for consumer use or business use. Further, the present invention can also be used for a recording apparatus or the like that is mounted on or connectable to various computer equipment for consumer use or business use.

1 is a schematic plan view showing a basic structure of an optical disc having a plurality of recording areas as an information recording medium that is a target of a recording operation of an embodiment of the information recording apparatus of the present invention, and a schematic cross-sectional view of the optical disc; FIG. 6 is a schematic conceptual diagram of a recording area structure in the radial direction associated with the recording area; It is a block diagram which shows notionally the basic composition of the Example which concerns on the information recording device of this invention. It is a flowchart which shows notionally the flow of the whole 1st operation example of the information recording device based on a present Example. It is sectional drawing which shows notionally the recording operation of the OPC pattern to the L1 layer of the information recording device of a present Example, and the data recording operation. FIG. 5 is a schematic timing chart showing one OPC process in the case of 16 power steps in the information recording apparatus according to the present embodiment. It is a graph which shows notionally the correlation information which shows the correlation of the recording laser power and asymmetry used in the information recording device which concerns on a present Example, and the correction process of the said correlation information. It is a flowchart which shows notionally the flow of the whole 2nd operation example of the information recording device based on a present Example. It is explanatory drawing which shows one specific example of the waveform of the recording pulse before correction | amendment in the information recording apparatus which concerns on a present Example, and after correction | amendment. 4 is a graph conceptually showing correlation information indicating a correlation between recording laser power and asymmetry used in the information recording apparatus according to the present embodiment and substantial correlation information after correcting the pulse waveform. It is explanatory drawing which shows the other specific example of the waveform of the recording pulse before correction | amendment in the information recording apparatus which concerns on a present Example, and after correction | amendment. 4 is a graph conceptually showing correlation information indicating a correlation between recording laser power and asymmetry used in the information recording apparatus according to the present embodiment and substantial correlation information after correcting the pulse waveform.

Explanation of symbols

100 Optical disc 102 Lead-in area 105 Data recording area 108 Lead-out area 109 Middle area 120 PCA
300 Information Recording Device 352 Optical Pickup 354 CPU
355 Memory 358 LD driver 359 OPC pattern generator

Claims (6)

By irradiating an information recording medium comprising a first recording layer on which recording information is recorded and a second recording layer on which the recording information is recorded via the first recording layer with a laser beam having a variable recording power Recording means for recording the recording information;
Using the recording means, recording the test information for test recording by irradiating the second recording layer with the laser light through the recording area where the recording information in the first recording layer is not recorded, Calculation means for calculating an optimum power of the laser beam when the recording information is recorded by irradiating the second recording layer with the laser beam through a recording area where the recording information is recorded in the first recording layer. When,
Control means for controlling the recording means to irradiate the laser beam with the optimum power calculated by the calculating means when recording the recording information on the second recording layer,
The information recording apparatus characterized in that the control means controls the recording means to irradiate the laser light having a predetermined waveform different from the waveform of the laser light for recording the trial information.   The calculation means includes a characteristic of the laser beam irradiated with the recording information in the first recording layer through an unrecorded recording area, and a recording area in which the recording information in the first recording layer has been recorded. 2. The information recording according to claim 1, wherein the recording unit is controlled to irradiate the laser light having the different predetermined waveform based on a difference from the characteristic of the laser light irradiated in the first step. apparatus. The waveform of the laser beam includes a combination of a short pulse and a long pulse,
The control means controls the recording means so that the short pulse in the predetermined waveform becomes longer or shorter on the time axis than the waveform of the laser beam for recording the trial information. The information recording apparatus according to claim 1, wherein:   The control means controls the recording means so that the short pulse in the predetermined waveform is longer or shorter than the laser light waveform for recording the trial information by a rate of 5% or more and 10% or less. The information recording apparatus according to claim 3, wherein the information recording apparatus is controlled. By irradiating an information recording medium comprising a first recording layer on which recording information is recorded and a second recording layer on which the recording information is recorded via the first recording layer with a laser beam having a variable recording power An information recording method in an information recording apparatus comprising a recording means for recording the recording information,
Using the recording means, recording the test information for test recording by irradiating the second recording layer with the laser light through the recording area in which the recording information in the first recording layer is not recorded, Calculation for calculating an optimum power of the laser beam when the recording information is recorded by irradiating the second recording layer with the laser beam through a recording area in which the recording information in the first recording layer has been recorded. Process,
When recording the recording information on the second recording layer, the recording area in which the recording information in the first recording layer is recorded is irradiated with the laser light at the optimum power obtained. And a control step of controlling the recording means so as to irradiate the laser beam having a predetermined waveform different from the waveform of the laser beam for recording the trial information on the second recording layer. An information recording method characterized by the above. A computer program for recording control for controlling a computer provided in the information recording apparatus according to claim 1, wherein the computer functions as at least part of the recording unit, the calculating unit, and the control unit. A computer program characterized by the above.

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