JP2007213671A - Optical disk device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical disk device for stably detecting wobble signals and LPP signals without saturating a wobble detection circuit or an LPP detection circuit. <P>SOLUTION: A PU head 2 of the optical disk device 1 detects RF signals and wobble signals from the laser reflected light of an optical disk 100. A control part 10 detects the reflectivity and disk kind of the optical disk 100 when the optical disk 100 is mounted. Also, the control part 10 detects optimum recording power by OPC (Optimum Power Control). The control part 10 refers to a data table 11 for gain determination from the reflectivity and the disk kind, determines the amplification factor of an RF signal amplifier circuit 3 and an AGC circuit 4 and indicates the determined value to the RF signal amplifier circuit 3 and the AGC circuit 4. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an optical disc apparatus that appropriately acquires a wobble signal.

  In general, a wobble signal or the like necessary for detecting a recording position when recording information is recorded in advance on an optical disc of a standard such as DVD-R or DVD-RW used as an information recording medium. The wobble signal is recorded in advance by groove wobbling formed by meandering the guide groove in the radial direction of the optical disc at a predetermined period. The LPP signal is recorded in advance as pits on the land between the grooves.

  In a conventional optical disc apparatus, a laser beam is irradiated onto an optical disc, and a laser beam is reflected from a signal obtained by four light receiving elements to perform a predetermined subtraction process to generate a differential signal. The signal and the LPP signal were detected.

  In order to adjust the amplitude of the amplitude of the differential signal, a signal amplified in advance by an amplifier circuit such as an AGC (Automatic Gain Control) circuit is input and input to the differential circuit, or the differential signal is amplified and wobbled. The signal and the LPP signal were detected.

  In such a configuration, in order to detect a wobble signal and acquire address information, it is necessary to appropriately set the amplification factor of the AGC circuit. Therefore, conventionally, when the optical disc is mounted, the amplification factor of the AGC circuit corresponding to the magnitude of the amplification factor (RF amplification factor) of the RF signal is set in advance.

  Conventionally, there has been disclosed a configuration in which the amplification factor is changed so that the output signals of the two amplifier circuits are balanced with a constant amplitude intensity during data recording / reproduction from an optical disk.

As a method for setting a control value using a data table, in Patent Document 1, when data is recorded by running OPC (Optimum Power Control), the type of optical disk and the ambient temperature at the time of data recording are described. The laser power correction value set to output a predetermined laser power at different times is stored in advance in a table, and when the laser power is increased, the correction value is added from the storage means and the laser is added. Is disclosed.
JP 2003-196634 A

  However, if recording is performed with the recording power value determined by performing OPC (Optimum Power Control) in the APC (PowerCalibration Area) of the optical disc as in the past, and the RF signal is output with the reflected light obtained at that time, the balance is simply adjusted. However, when the recording power is high, the output signal of the AGC circuit does not have an appropriate amplitude, and the wobble detection circuit to which the output signal is input becomes saturated. As a result, there has been a problem that information necessary for detecting a recording position when recording information cannot be obtained accurately and data recording becomes unstable.

  Patent Document 1 does not disclose that the output signal of the wobble signal output circuit is adjusted when the recording power is strong.

  An object of the present invention is to provide an optical disc apparatus capable of stably detecting a wobble signal and an LPP signal.

  The optical disc apparatus of the present invention has the following configuration in order to solve the above problems.

(1) The present invention
A recording means for detecting the optimum power for the optical disc set in the main body and recording data based on the optimum recording power detected here;
A wobble signal output circuit that outputs and outputs a wobble signal from the reflected light from the optical disc,
In an optical disc device comprising:
An amplification factor indicating means for determining an amplification factor of the wobble signal output circuit according to the optimum recording power and instructing the determined value of the amplification factor to the wobble signal output circuit;

  In this configuration, the amplification factor instruction means determines the amplification factor of the wobble signal output circuit according to the optimum recording power determined by the optimum recording power detection means, and instructs the determined value of the amplification factor to the wobble signal output circuit. To do. Thus, the amplification factor of the wobble signal output circuit is appropriate for detecting the wobble signal, and the wobble signal can be detected stably.

(2) The present invention
Further, the storage device stores a data table in which an optimum recording power value and an amplification factor value instructed to the wobble signal output circuit are associated in advance.
The amplification factor instructing unit determines the amplification factor by referring to the amplification factor value corresponding to the optimum recording power value output from the optimum recording power detection unit from the data table.

  In this configuration, the amplification factor instruction means has a data table in which the optimum recording power value and the amplification factor value instructed to the wobble signal output circuit are associated in advance. By referring to it, an appropriate amplification factor can be easily determined.

(3) The present invention
Furthermore, it comprises a reflectance detection means for detecting the reflectance of the optical disc when mounting the optical disc,
The storage means stores the data table according to the reflectance of the optical disc,
The amplification factor instruction means further determines the amplification factor by referring to the reflectance of the optical disc.

  As described above, unless the amplitude of the signal detected by the light receiving element is adjusted, the wobble detection circuit or the like may be saturated. Here, whether or not the wobble detection circuit or the like is saturated is influenced not only by the optimum recording power value as shown in the configuration (1) but also by the reflectance of the optical disk. In this configuration, a plurality of data tables for determining the amplification factor of the wobble signal output circuit are stored in accordance with the reflectance of the optical disk, and the amplification factor is determined with reference to this, so that (1), (2) In addition to the above configuration, the amplification factor of the wobble signal output circuit is appropriate for detecting the wobble signal, and the wobble signal can be detected stably.

(4) The present invention
Furthermore, a disc type detecting means for detecting a disc type based on the reflectance is provided,
The storage means stores the data table according to the type of the optical disc,
The amplification factor instruction means further determines the amplification factor by referring to the type of the optical disc.

  In this configuration, the disc type detecting means detects the type of the optical disc, for example, the type of CD-ROM, CD-R, DVD-ROM, DVD-R, DVD + R, etc. from the reflectance of the laser beam, Accordingly, since a plurality of data tables for determining the amplification factor of the wobble signal output circuit are stored and the amplification factor is determined with reference to this, the wobble signal output is increased in addition to the configurations of (1) to (3). The amplification factor of the circuit is appropriate for detecting the wobble signal, and the wobble signal can be detected stably.

  According to the present invention, since the amplification factor of the wobble signal output circuit is determined based on the recording power and the reflectance of the optical disc, the amplification factor is appropriate for detecting the wobble signal, and the wobble signal can be detected stably. . As a result, the wobble signal can be stably detected without the influence of the recording power and reflectivity of the optical disc.

<Outline Explanation of Optical Disc Device of the Present Embodiment>
Hereinafter, an outline of an optical disk apparatus according to an embodiment of the present invention will be described with reference to FIG.
FIG. 1 is a block diagram showing a part of the configuration of the optical disc apparatus 1. The optical disc apparatus 1 includes a control unit 10 that controls the operation of the optical disc apparatus 1, a pickup (PU) head 2 that irradiates the optical disc 100 with laser light and detects reflected light, and data recorded on the optical disc 100. A recording / reproducing processing circuit 7 for reading is provided.

  The apparatus according to the present embodiment has a feature in controlling the RF signal amplifier circuit 3 and the AGC circuit 4. The RF signal amplification circuit 3 amplifies the RF signal and outputs it to the recording / reproduction processing circuit 7. The AGC circuit 4 (Automatic Gain Control) amplifies a signal obtained by performing a predetermined known calculation on the detection signal obtained by the photodetector 23 divided into four as shown in FIG. 5. Output to the land pre-pit detection circuit 6. The signal amplified by the AGC circuit 4 includes a wobble signal and a land pre-pit (hereinafter referred to as “LPP signal”) signal. The wobble signal and (LPP) signal are necessary for detecting a recording position when information is recorded, and these are recorded in advance on the optical disc 100. The wobble signal is recorded in advance by groove wobbling formed by meandering the guide groove in the radial direction of the optical disc at a predetermined period, and is used for detecting the rotational speed of the disc. The LPP signal is recorded in advance as pits on the land between the grooves. The land prepit detection circuit 5 and the wobble detection circuit 6 extract a wobble signal and an LPP signal from the output of the AGC circuit 4.

  When recording data on the optical disc 100, the intensity of the amplitude of the detection signal of the photodetector 23 that detects the reflected light reflected by the optical disc 100 increases. As a result, the internal elements of the recording / reproduction processing circuit 7 that is the output destination of the RF signal amplifier circuit 3 are saturated, and the wobble detection circuit 5 and the land prepit detection circuit 6 are saturated. Position information cannot be acquired and data recording may become unstable. Therefore, the control unit 10 of the optical disc apparatus 1 according to the present embodiment sets an appropriate amplification factor with reference to the amplification factor determination data table 11 stored in the ROM inside the control unit 10, and sets the RF signal amplification circuit 3, Output to the AGC circuit 4. In this amplification factor determination data table 11, the amplification factor is determined by the recording power, which is the output intensity of the light of the laser diode 21 at the time of data recording, the reflectance of the disk measured at the time of mounting, and the type of the disk. From the values of these elements, the amplification factor is determined with reference to the amplification factor determination data table 11.

<Description of Configuration of Optical Disc Device 1 of the Present Embodiment>
The optical disc apparatus 1 will be described with reference to FIG. The optical disc apparatus 1 has a pickup (PU) head 2 that irradiates the optical disc 100 with laser light and detects the reflected light, and an RF signal amplification that amplifies the RF signal read from the optical disc 100 and outputs the amplified RF signal to the recording / reproduction processing circuit 7. A circuit 3 is provided.
Further, the optical disc apparatus 1 includes a drive circuit 32 and an FE (Forcus Error) / TE (Tracking Error) generation unit 31 in order to drive an actuator 24 for following a predetermined track of the optical disc 100.
The optical disc apparatus 1 also includes a recording / reproducing processing circuit 7 that reads data recorded on the optical disc 100, a laser power control circuit 70 that adjusts the laser output during data recording, a laser driving circuit 71, and recording during reproduction. / A decoder 72 for decoding the data of the reproduction processing circuit 7 is provided.
The optical disk apparatus 1 also includes an AGC circuit 4 (Automatic Gain Control) that amplifies a wobble signal indicating a recording position and an LPP signal when data is recorded on the disk and outputs the amplified signal to the recording / reproduction processing circuit 7, and wobble detection A circuit 5 and a land pre-pit detection circuit 6 are provided.
In addition, the optical disc apparatus 1 includes a control unit 10 that controls the operation of the main body of the optical disc apparatus 1. Each will be described below.

  The PU head 2 will be described. The PU head 2 includes a pickup lens 20, a laser diode 21, a beam splitter 22, a photodetector 23, a collimator lens (not shown), and the like, as in a known optical disk device. The PU head 2 also includes two actuators 24 (a focusing actuator that moves the focal point of the laser light applied to the optical disc 100 in the optical axis direction) and a tracking actuator that moves the laser light in the radial direction of the optical disc 100. ).

  The beam splitter 22 separates the light emitted from the laser diode 11 and the light reflected from the optical disk 2. The photodetector 23 detects reflected light from the optical disc 2. The collimator lens converts light emitted from the laser diode 11 that is a point light source into parallel light.

  With such a configuration of the PU head 2, the laser diode 21 outputs laser light with a predetermined intensity by driving a laser driving circuit 71 described later. The laser light passes through the collimator lens, is reflected by the beam splitter 22, and is condensed on the surface of the optical disc 100 by the pickup lens 20. The laser light is reflected by the optical disc 100, and the reflected light is detected by the four photodetectors 23. The photodetectors 23 each output a detection signal. The actuator 24 causes the laser beam to follow a desired recording track by driving a drive circuit 32 described later.

  The RF signal amplifier circuit 3 will be described. The RF signal amplifying circuit 3 amplifies the RF signal obtained by fully adding the four detection signals detected by the photodetector 23. This RF signal is used to read data on the optical disc 100. The amplification factor of the RF signal is set based on the input of the amplification factor setting signal 12 set by the control unit 10.

  The FE / TE generator 31 and the drive circuit 32 will be described. The FE / TE generator 31 generates a focus error signal (FE signal) FE by a known method based on the signal output from the photodetector 13. For example, the focus error is calculated by the calculation of FE = (A + C) − (B + D), assuming that the four detection signals of the photodetector 23 are A, B, C, and D clockwise. The FE / TE generator 31 outputs these FE and TE to the drive circuit 32, and the drive circuit 32 generates a signal for driving the actuator 24 based on these FE and TE.

  The recording / reproducing processing circuit 7, the laser power control circuit 70, the laser driving circuit 71, and the decoder 72 will be described. The recording / reproducing processing circuit 7 detects a change in reflectance due to a recording track on the data recording surface of the optical disc 100 from the RF signal. During reproduction, the data output from the RF signal amplification circuit 3 is binarized according to the presence or absence of a recording track on the optical disc 100 by a reproduction circuit in the recording / reproduction processing circuit 7. As this reproduction circuit, a general circuit configuration for data reproduction may be used. The laser power control circuit 70 controls the intensity of the laser, and gives a laser intensity signal necessary for data recording and erasure to the laser diode 21 when data is recorded on the optical disc 100. At the time of reading, a signal having an intensity lower than these intensities is given to the laser diode 21. The decoder 72 decodes the RF signal processed by the signal processing circuit 23 into a reproduction signal.

  The AGC circuit 4 includes two independent amplifiers, and amplifies each of the predetermined detection signals detected by the photodetector of the PU head 2 and outputted by the light receiving elements arranged in the radial direction. Also, the amplification factor setting signal 13 set by the control unit 10 is input. As a result, the AGC circuit 4 amplifies the detection signal with an amplification factor according to the amplification factor setting signal 13. As a result, the output signal of the AGC circuit 4 has an intensity with an amplitude suitable for detecting a change in reflectance due to groove wobbling and LPP of the optical disc 100. The output signal of the AGC circuit 4 is output to the wobble detection circuit 5 and the LPP detection circuit 6.

  The wobble detection circuit 5 and the LPP detection circuit 6 extract the wobble signal and the LPP signal from the output of the AGC circuit 4, respectively. As the wobble detection circuit 5 and the LPP detection circuit 6, a known circuit configuration for wobble detection and LPP detection may be used. For example, for wobble detection, radial wobble can be detected by performing a difference calculation on the output of the amplifier that amplifies the input of the light receiving elements arranged in the radial direction. The wobble signal and the LPP signal are output to a subsequent reproduction circuit (not shown). The wobble signal generates a recording clock and is used to control the rotational speed of the optical disc. The LPP signal generates a recording clock and is used for detecting address information.

  Note that wobble detection by the AGC circuit 4 and the wobble detection circuit 5 may be performed by performing a difference operation on the outputs of the light receiving elements arranged in the radial direction and then amplifying by the AGC circuit 4. In FIG. 1, two light receiving elements are used for wobble detection. However, calculation may be performed using outputs of the four light receiving elements by known means.

  The control unit 10 will be described. The control unit 10 includes a signal processing LSI, a memory, a ROM, and the like (not shown) and performs various signal processing. The control unit 10 controls each unit of the optical disc apparatus 1 such as the laser power control circuit 70, the RF signal amplification circuit 3, and the AGC circuit 4. A ROM (not shown) in the control unit 10 stores an amplification factor determination data table 11 for determining an amplification factor to be instructed to the RF signal amplifier circuit 3 and the AGC circuit 4 at the time of data recording.

<Description of data table for determining amplification factor>
Next, the amplification factor determination data table 11 will be described with reference to FIG. FIG. 2 shows the gain determination data table 11 shown in FIG. FIG. 2A shows the case of DVD-R, and FIG. 2B shows the case of DVD-RW. The control unit 10 stores an amplification factor determination data table 11 for each type of disk.

  As shown in FIGS. 2A and 2B, the amplification factor determination data table 11 includes the RF signal amplifier circuit 3, AGC, based on the disc type, the recording power applied to the laser diode 21 during data recording, and the reflectance. The amplification factor to be set in the circuit 4 can be referred to. For example, in the table shown in FIG. 2A, the RF amplification gain when the disk is DVD-R, the reflectance is “low”, and the recording power is “less than 16 mW” is set to −6 dB. In the table shown in FIG. 2B, the AGC gain is set to 0 dB when the disc is DVD-RW, the reflectance is “high”, and the recording power is “16 mW or more”.

  Here, in FIG. 2, the RF amplification gain represents the amplification factor set in the RF signal amplification circuit 3, and the AGC gain represents the amplification factor set in the AGC circuit 4. The recording power is a power determined by OPC (Optimum Power Control), which will be described later. In this embodiment, the amplification factor is divided depending on whether the output of the laser driving circuit 71 to the laser diode 21 exceeds 16 mW. Further, the amplification factor determination data table 11 classifies the reflection factor of the disk in the case of the amplification factor. In FIG. 2, the threshold value for discriminating between “high” and “low” reflectivity can be set to 50%, for example, in both FIGS. 2A and 2B, and depending on the disc type It is also possible to change this threshold.

  Next, the significance of adjusting the amplification factors of the RF signal amplifier circuit 3 and the AGC circuit 4 will be described. First, when recording data on the optical disc 100, since the recording power applied to the laser diode 21 is large, the intensity of the amplitude of the detection signal of the photodetector 23 that detects the reflected light reflected by the optical disc 100 increases. As a result, the internal elements of the recording / reproduction processing circuit 7 that is the output destination of the RF signal amplifier circuit 3 are saturated, and the wobble detection circuit 5 and the land prepit detection circuit 6 are saturated. Position information cannot be acquired and data recording may become unstable. Therefore, the control unit 10 of the optical disc apparatus 1 according to the present embodiment sets an appropriate amplification factor with reference to the amplification factor determination data table 11 and supplies the amplification factor setting signals 12 and 13 to the RF signal amplifier circuit 3 and the AGC circuit. 4 is output.

  Next, input for determining the amplification factors of the RF signal amplifier circuit 3 and the AGC circuit 4 will be described. It is mainly the recording power and the optical disc reflectivity that affect the amplitude of the detection signal. Further, depending on the type of the optical disc 100, it may be preferable to change the reflectance threshold or the recording power threshold in the gain determination data table 11 shown in FIG. Therefore, the gain determination data table 11 shown in FIG. 2 can obtain gains to be set in the RF signal amplifier circuit 3 and the AGC circuit 4 with the type, reflectance, and recording power of the optical disc 100 as inputs. .

Next, the recording power of the gain determination data table 11 and the reflectance of the optical disc will be described.
The recording power is determined by OPC (Optimum Power Control). OPC uses a method (not shown) to step the recording power of laser light irradiated in a predetermined recording area (PCA (Power Calibration Area)) of this optical disc in a predetermined range prior to the start of data recording on the optical disc. Specifically, test data is recorded while changing (for example, 16 steps), and the optimum recording power of the laser beam output when data is recorded on the optical disc is detected.

  The reflectivity of the optical disc varies depending on the type and variation of the optical disc. For example, the reflectivity differs between the write once optical disc and the rewritable optical disc, and the reflectivity differs depending on the model number even in the same recording type optical disc. In addition, since a recording track is formed on the data recording surface, the reflectance depends on the recorded area of the data (area where the recording track is formed) and the unrecorded area (area where the recording track is not formed). Come different. The reflectance is also affected by groove wobbling and LPP.

  The control unit 10 calculates the disk reflectivity of the optical disk 100. Specifically, the intensity of the light quantity signal actually reflected from the optical disk 100 is obtained based on the intensity of the light quantity signal when the laser light emitted from the laser diode 21 is totally reflected when the optical disk 100 is mounted. Calculate the rate.

  According to the amplification factor determining data table 11 described above, the amplification factors of the RF signal amplifier circuit 3 and the AGC circuit 4 can be easily obtained, and the control unit 10 outputs the output signals of the RF signal amplifier circuit 3 and the AGC circuit 4. Can be set to an appropriate amplitude intensity. Further, since the amplification factor of the AGC circuit 4 is hardly affected by other amplifier circuits as in the prior art, the noise of the other amplifier circuits is not added to the AGC circuit 4, and the AGC circuit 4 also from this point. The output signal can be stabilized.

  It should be noted that the RF signal can be acquired during the recording of data while the high recording power is actually being output. However, there is no need to use this RF signal, and the recording / reproduction processing circuit 7 has an internal structure. Even if these elements are saturated, there is no problem that data cannot be detected. However, if a signal that saturates is output, noise may be scattered inside the recording / reproduction processing circuit 7, and the gain as shown in FIG. Lower.

  In FIG. 2, the case is divided into two according to the reflectivity. However, three or more may be used, and the disc type is not only for DVD-R and DVD-RW, but also for determining the gain for other optical discs. A data table 11 may be prepared.

<Description of processing flow of gain setting processing>
Next, a flowchart representing the amplification factor setting process in the control unit 10 will be described with reference to FIG. FIG. 3 shows a processing flow of amplification factor setting processing to be instructed to the RF signal amplifier circuit 3 and the AGC circuit 4 at the time of data recording. Note that this processing flow also includes processing originally used for other purposes such as mount processing (ST2) and OPC (ST3), and this gain setting is performed using data obtained by these processing. Do.

  ST1 will be described. In ST1, if the optical disc 100 is not set, the sequence becomes N and waits, and if the disc is set, the sequence becomes Y and moves to ST2.

  ST2 will be described. In ST2, mount processing ST21 to ST23 of the optical disc 100 is performed. In ST21, the laser beam reflected on the disk surface is detected to perform various measurements such as disk reflectivity detection, and the measurement results are recorded in the memory. When the scanning is finished, the laser diode is turned off. In ST23, the disc type is detected from the disc reflectivity recorded in the ROM. Here, when the disc type cannot be detected because the optical disc 100 does not correspond to the apparatus specification, error display and ejection processing are performed. Regarding error display and ejection processing, general processing may be used and will not be described in detail here.

  Next, ST3 will be described. In ST3, the above-described OPC is performed, and the processes of ST31 to ST33 are performed. In ST31, the PU head 2 is scanned and moved to the PCA (Power Calibration Area) of the optical disc 100. In ST32, test data is recorded while changing the recording power of the laser beam stepwise (for example, 16 steps) within a predetermined range. In ST33, the optimum recording power of the laser beam optimum for recording on the optical disc 100 is detected from the position of the optical disc 100 changed in stages in ST32. This optimum recording power is used to drive the laser drive circuit 71 when data is recorded on the optical disc 100.

  Next, ST4 and ST5 will be described. In ST4, based on the type of optical disc 100, the reflectance of the optical disc 100, and the optimum recording power obtained in the process of ST2 and ST3, the RF signal amplification circuit 3, The amplification factor to be set in the AGC circuit 4 is determined. In ST5, the amplification factor setting signals 12 and 13 are output to the RF signal amplifier circuit 3 and the AGC circuit 4 in order to set the amplification factor determined in ST4.

1 is a block diagram illustrating a schematic configuration of an optical disk device according to the present embodiment. The figure showing the table for determining the gain of the optical disk device of this embodiment The flowchart showing the amplification factor setting process of the optical disc apparatus of this embodiment

Explanation of symbols

DESCRIPTION OF SYMBOLS 1- Optical disk apparatus, 10- Control part, 11- Data table for gain determination 2-PU head, 20- Pickup lens, 21- Laser diode 22- Beam splitter, 23- Photo detector, 24- Actuator 3- RF signal amplification circuit 31-FE / TE generator, 32-drive circuit 4-AGC, 5-wobble detection circuit, 6-land pre-pit detection circuit 7-recording / reproduction processing circuit, 70-laser power control circuit 71-laser drive circuit, 72-decoder 100-optical disc

Claims (5)

A recording means for detecting the optimum power for the optical disc set in the main body and recording data based on the optimum recording power detected here;
A wobble signal output circuit that outputs and outputs a wobble signal from the reflected light from the optical disc,
Disc type detection means for detecting the reflectivity of the optical disc when the optical disc is mounted, and detecting the disc type based on the reflectivity;
In an optical disc device comprising:
Storage means for storing a data table in which an optimum recording power value, the reflectance and the disc type, and an amplification factor value instructed to the wobble signal output circuit are associated in advance;
An optical disc apparatus comprising: an amplification factor instructing unit that determines the amplification factor by referring to an amplification factor value corresponding to the optimum recording power value output by the optimum recording power detection unit from the data table. A recording means for detecting the optimum power for the optical disc set in the main body and recording data based on the optimum recording power detected here;
A wobble signal output circuit that outputs and outputs a wobble signal from the reflected light from the optical disc,
In an optical disc device comprising:
An optical disc apparatus comprising: an amplification factor indicating means for determining an amplification factor of the wobble signal output circuit according to the optimum recording power and instructing the determined value of the amplification factor to the wobble signal output circuit. Further, the storage device stores a data table in which an optimum recording power value and an amplification factor value instructed to the wobble signal output circuit are associated in advance.
3. The amplification factor according to claim 2, wherein the amplification factor instructing unit determines the amplification factor by referring to a gain value corresponding to an optimum recording power value output from the optimum recording power detection unit from the data table. Optical disk device. Furthermore, it comprises a reflectance detection means for detecting the reflectance of the optical disc when mounting the optical disc,
The storage means stores the data table according to the reflectance of the optical disc,
4. The optical disk apparatus according to claim 3, wherein the amplification factor instruction means further determines the amplification factor by referring to the reflectance of the optical disk. Furthermore, a disc type detecting means for detecting a disc type based on the reflectance is provided,
The storage means stores the data table according to the type of the optical disc,
The optical disk apparatus according to claim 4, wherein the amplification factor instructing unit further determines the amplification factor by referring to a type of the optical disk.

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