JP2005071460A - Optical disk drive and its recording control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve recording quality by forming a stable recording mark. <P>SOLUTION: In an optical disk drive for driving a light emitting element emitting laser beams in accordance with a recording pulse having a read power value, a write power value larger than the read power value and a bias value superposed to a specified section at a top side in a section of this write power value, set data for setting the bias value corresponded to each optical disk are corrected in accordance with a predetermined 1st data group used as a reference of the setting data and a 2nd data group which are actually measured data of the setting data corresponded to the 1st data group, then a control means is prepared for driving the light emitting element by superposing the bias value set in accordance with the set data after the correction on the write power value. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an optical disc apparatus and a recording control method thereof.

  In recent years, write once type write-once optical discs (CD-R media, DVD ± R media, etc.) have become popular as recordable optical discs. In this write-once optical disc, several laser diode drive systems have been proposed so that recording marks can be accurately formed with distortion suppressed.

  For example, there is a multi-pulse system as a laser diode driving system. In the multi-pulse method, laser light is emitted at a read power value Pr in a space section in which no recording mark is formed, and in accordance with a recording pulse train having a read power value Pr and a write power value Pm in a mark section in which a recording mark is formed. This is a method of forming a recording mark by emitting laser light with high power. According to this multi-pulse method, a section having the read power value Pr in the mark section can be set as a cooling section, and the heat distribution can be made uniform.

  Further, as a laser diode driving method, there is a non-multi-pulse method in which one recording mark is formed by one recording pulse. It is known that the heat distribution in the recording mark cannot be made uniform only by the non-multi-pulse method, and the recording mark is distorted like a tear. Therefore, in the non-multi-pulse system, a bias value Δ determined according to the type of the optical disk such as a predetermined section (hereinafter referred to as an LDH (LD High) section) on the head side of the mark section, a manufacturer, a recording speed, and the like is written. A technique for driving a laser diode by superimposing it on the power value Pm has been proposed (see, for example, Patent Document 1 shown below). FIG. 9 shows the configuration of the peripheral circuit including the LD driver 91 for an optical disc apparatus (hereinafter referred to as a conventional optical disc apparatus) employing this technique.

  In FIG. 9, the switch 93 is controlled to be conductive in both the space section and the mark section, and the read power signal VRDC for obtaining the read power value Pr is transmitted from the read power signal generation circuit 92 via the switch 93 to the LD driver. 91. The switch 95 is controlled so as to be conductive only in the mark section, and the write power signal VWDC for obtaining the write power value Pm is supplied from the write power signal generation circuit 94 to the LD driver 91 via the switch 95. The

  The read power value Pr and the write power value Pm are based on sampling data of the LD90 output actually detected by the FMD (Front Monitor Diode) 100 by the corresponding APC (Automatic Power Control) circuits 101 and 102. APC in which the read power value Pr and the write power value Pm are constant is normally performed.

  Next, the system controller 96 uses, as data relating to the bias value Δ according to the type of the optical disc, a Ph / Pm ratio (L1 / L2) which is a ratio between the peak value Ph in the LDH section and the write power value Pm, Attenuation rate setting data (hereinafter referred to as ATT setting value) for setting the attenuation rate ATT of the attenuator 97 corresponding to each Ph / Pm ratio is stored in a ROM or the like. That is, the system controller 96 sets the attenuation factor ATT of the attenuator 97 based on the ATT set value corresponding to the type of the optical disc, and as a result, the gain of the amplifier 98 is set.

  The switch 99 is controlled to conduct only in the LDH section, and a bias power signal ΔLDH for obtaining a bias value Δ is supplied from the amplifier 98 to the LD driver 91 via the switch 99. The bias power signal ΔLDH is a signal generated based on the attenuation factor ATT of the attenuator 97 set by the system controller 96, that is, the gain of the amplifier 98.

With the above configuration, the LD driver 90 has the read power signal VRDC supplied from the read power signal generation circuit 92, the write power signal VWDC supplied from the write power signal generation circuit 94, and the bias power signal ΔLDH supplied from the amplifier 98. Based on the above, a recording pulse as shown in FIG. 10 is formed to drive the LD 90.
JP 2003-85753 A

  In the conventional optical disc apparatus as shown in FIG. 9, the read power value Pr and the write power value Pm are controlled to be constant by the APC circuits 101 and 102, but the bias value Δ Since the LDH section is relatively short with respect to the section, it is difficult to perform APC by sampling. For this reason, the bias value Δ is simply set by open loop control based on the attenuation factor ATT of the attenuator 97 set by the system controller 96.

  However, the input / output characteristics of the attenuator 97, the amplifier 98, the LD driver 91, and the LD 90 originally have nonlinearity, and it is difficult to uniquely determine the input / output characteristics. Furthermore, there are variations in the elements 97, 98, 91, 90 themselves, and various characteristics vary depending on ambient environmental conditions such as temperature. Therefore, even if the attenuation rate ATT of the attenuator 97 corresponding to the type of the optical disk is uniquely set by the system controller 96, as shown in FIG. 10, the expected bias value Δ cannot be obtained, and the Ph / Pm ratio is There was a problem that it was not constant. Also, as a result, a stable recording mark shape cannot be obtained, and an error occurs in the recording data, which may reduce the recording quality.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an optical disc apparatus capable of obtaining a stable recording mark shape and a recording control method therefor.

  The main present invention for solving the above-described problem is that a read power value, a write power value larger than the read power value, and a bias value superimposed on a predetermined section on the head side in the section of the write power value. In an optical disc apparatus that drives a light emitting element that emits laser light based on a recording pulse, a predetermined first data group serving as a reference for setting data for setting the bias value, and the first The setting data corresponding to each optical disc is corrected based on the second data group that is actually measured data of the setting data corresponding to the data group, and the setting data is set based on the corrected setting data. Control means for driving the light emitting element by superimposing a bias value on the write power value is provided.

  According to the present invention, as described above, the bias value obtained from the corrected setting data becomes a reference corresponding to the first data group by correcting the setting data according to each optical disc. A value similar to the bias value is obtained. For this reason, since fluctuations in the bias value can be suppressed, a stable recording mark can be formed, and an optical disc apparatus with improved recording quality can be provided.

  Other features of the present invention will become apparent from the accompanying drawings and the description of this specification.

  According to the present invention, it is possible to provide an optical disc apparatus and a recording control method thereof that can obtain a stable recording mark shape.

=== Example ===
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

<System configuration>
A schematic configuration of a system including an optical disc apparatus according to an embodiment of the present invention will be described with reference to FIG.

  First, the optical disc 10 is a write-once optical disc such as a CD-R media or a DVD ± R media. The optical disc apparatus 40 performs recording on the write-once optical disc 10 based on a non-multi-pulse recording pulse having a read power value Pr (about 1 mW) and a write power value Pm (about 10 mW). Configured. The non-multi-pulse recording pulse has a read power value Pr in a space section where no recording mark is formed, and a write power value Pm in a mark section where a recording mark is formed. One recording mark is formed by one recording pulse. .

  Further, the optical disc apparatus 40 has a bias value Δ (determined according to the type of the optical disc 10 such as manufacturer and recording speed in a predetermined section (hereinafter referred to as LDH (LD High) section) in the mark section. The difference between the write power value Pm and the read power value Pr is about several to 20%). Note that the ratio between the peak value Ph in the LDH section and the write power value Pm is usually called the Ph / Pm ratio. By adopting such a configuration, the heat distribution in the recording mark can be made uniform.

  Here, the optical disc apparatus 40 employs a non-multipulse method in which the bias value Δ is superimposed on the write power value in the LDH section. Therefore, the configuration of the optical disc device 40, particularly the mechanism for driving a laser diode (LD) 12 will be described in detail with reference to the time chart of FIG. 2 as appropriate.

  The optical pickup 11 includes an LD 12 (“light emitting element”) that emits laser light for recording and reproduction with respect to the optical disc 10. The LD 12 is driven by an LD driver 14. Further, the optical pickup 11 includes a front monitor diode (FMD) 13 for receiving laser light emitted from the LD 12 to the optical disc 10 and separated in the middle of the optical path. Yes. The FMD 13 generates a signal (hereinafter referred to as a power monitor signal) corresponding to the received light current according to the amount of received laser light. In addition to the configuration described above, the optical pickup 11 performs an optical lens, a photodetector that receives reflected light (reproduction signal) from the optical disc 10, feed control, tracking control, and focus control of the optical pickup 11. However, the illustration and detailed description thereof are omitted.

  The system controller 15 (“gain setting unit”, “correction means”) controls the overall system control of the optical disc apparatus 40 related to recording or reproduction of the optical disc 10. For example, the system controller 15 controls the activation of the encoder / decoder 17 in order to perform demodulation or modulation processing according to the optical disc 10 when recording or reproducing the optical disc 10.

  Further, the system controller 15 supplies the first APC reference voltage signal (digital value) to the D / A converter 19 in order to perform APC related to the read power value Pr. Similarly, a second APC reference voltage signal (digital value) is supplied to the D / A converter 26 in order to perform APC (Automatic Power Control) related to the write power value Pm.

  Further, the system controller 15 supplies an ACC reference voltage signal (digital value) to the D / A converter 23 in order to perform ACC (Automatic Current Control) related to the write power value Pm for a predetermined period from the start of recording. Since the system controller 15 controls conduction / non-conduction of the switch 28, as a result, the write power signal VWDC output from the write power signal generation circuit 29 is either the ACC circuit 24 output or the APC circuit 27 output. One is selected.

  Further, the system controller 15 reads the ATT setting value corresponding to the type (manufacturer, recording speed, etc.) of the optical disc 10 from the strategy table 300 stored in the RAM 16, and based on this ATT setting value, sets the attenuation rate ATT of the attenuator 33. Set. The strategy table 300 stores strategy information that is referred to when adjusting a recording pulse. The strategy information includes, for example, a recommended Ph / Pm ratio for each manufacturer and recording speed, and an ATT set value corresponding to the Ph / Pm ratio, as shown in FIG. By the way, this strategy information may be stored in advance in the optical disc device 40, or the information in the strategy table 300 is updated by sequentially reading this information from the optical disc 10 as being pre-recorded in a predetermined area of the optical disc 10. May be.

  The RAM 16 ("storage means") is a memory that can be accessed by the system controller 15. For example, a nonvolatile memory such as an EEPROM or a flash memory, or a volatile memory such as an SRAM or a DRAM can be adopted. The RAM 16 is used when temporarily storing data that is being modulated or demodulated in the encoder / decoder 17. In addition to the above-described strategy table 300 (see FIG. 3), the RAM 16 also includes a reference set information table 400 (see FIG. 4) and an ATT set value storage table 500 (see FIG. 4) used when correcting an ATT set value described later. (See FIG. 5).

  As shown in FIG. 4, in the reference set information table 400, the power monitor signal generated by the FMD 11 is a write power in an optical disc apparatus (hereinafter referred to as a reference set) serving as a reference model for correcting the ATT set value. ATT setting values (hereinafter referred to as reference ATT setting values, referred to as “first data group”) when a predetermined Ph / Pm ratio is set with reference to the case where the value (10 mW) is indicated. Here, it is assumed that the optical disc apparatus that minimizes the fluctuation of the Ph / Pm ratio when the respective ATT set values are set is selected as the reference set. In addition, as the predetermined Ph / Pm ratio, in order to easily obtain a correction effect of an ATT set value described later, an approximate expression that is within a frequently used range (several% to 20% UP) and has high accuracy is used. Examples of values that can be obtained include 1.1 (B_ATT (10), “data A”) indicating 10% UP from a state without bias value Δ (100%) and a state without bias value Δ (100%). ) To 1.2 (B_ATT (20), “Data B”) indicating 20% UP. The reason why the two reference ATT set values are used is based on the use of a primary correction formula that does not require much calculation processing load in correcting the ATT set values described later.

  As shown in FIG. 5, the ATT set value storage table 500 is a measured value of the ATT set value indicating the same contents as the reference set information table 400 in the optical disc apparatus 40 (individual set) to be corrected for the ATT set value. ("Second data group") is stored. The ATT setting value stored in the ATT setting value storage table 500 is based on the case where the power monitor signal generated by the FMD 11 indicates the write power value (10 mW) together with the contents of the reference set information table 400. 1.1 (ATT (10), “Data C”) indicating 10% UP from the state without bias value Δ (100%), and 20% UP from the state without bias value Δ (100%). 2 (ATT (20), “data D”) is adopted. The reason for the two ATT set values is based on the use of a primary correction formula that does not require much processing load in correcting the ATT set values described later.

  The encoder / decoder 17 performs modulation or demodulation processing according to the type of the optical disc 10. For example, when the optical disk 10 is a CD-R medium, EFM (Eight to Fourteen Modulation) is adopted as a modulation method and CIRC (Cross Interleave Reed-Solomon Code) is adopted as an error correction method. Modulation or demodulation processing based on the method is performed.

  Also, the encoder / decoder 17 performs a sample hold signal RAPC (FIG. 2 (d) for holding the previous value after sampling for a predetermined sampling period with respect to the power monitor signal indicating the read power value Pr corresponding to the space section. )) Is supplied to a sample hold (S / H) circuit 18. Similarly, with respect to the power monitor signal indicating the write power value Pm corresponding to the mark section, a sample hold signal WAPC (see FIG. 2G) for holding the previous value after performing sampling for a predetermined sampling period, A sample hold (S / H) circuit 25 is supplied.

  Further, the encoder / decoder 17 sets LDON for setting the conduction / non-conduction of the switch 22 so as to form a recording pulse (see FIG. 2A) on which the bias value Δ is superimposed in the non-multi-pulse method described above. 2 (see FIG. 2C), a PEO signal for setting conduction / non-conduction of the switch 30 (see FIG. 2F), and an LDH signal for setting conduction / non-conduction of the switch 35 (FIG. 2). (See (h)) is supplied to each switch (22, 30, 35). Note that the LDON signal is at a level (H level) at which the switch 22 is turned on in both the space section and the mark section. The PEO signal is set to a level (L level) that makes the switch 30 non-conductive in the space section, and is set to a level (H level) that makes the switch 30 conductive in the mark section. Further, the LDH signal has a level (H level) that makes the switch 35 conductive in a predetermined period (3T to 11T) that is the head of the mark period, and a level (L level) that makes the switch 35 non-conductive in other periods. To do.

  A sample hold (S / H) circuit (18, 25) performs a sample hold process on the power monitor signal detected by the FMD 13 at a timing based on the sample hold signal RAPC / WAPC supplied from the encoder / decoder 17. Execute. Specifically, the sample and hold circuit 18 extracts the read power value Pr from the power monitor signal supplied from the FMD 13 during the period when the sample and hold signal RAPC is at the H level (sampling period). On the other hand, the sample hold circuit 25 extracts the write power value Pm from the power monitor signal supplied from the FMD 13 during the period when the sample hold signal WAPC is at the H level (sampling period).

  The APC circuit 20 compares the read power value Pr extracted by the sample and hold circuit 18 with the level of the first APC reference voltage signal converted from a digital value to an analog value by the D / A converter 19. Based on the comparison result, APC is performed so that the read power value Pr is constant (the level of the first APC reference voltage signal).

  Similarly, the APC circuit 27 compares the write power value Pm extracted by the sample and hold circuit 25 with the level of the second APC reference voltage signal converted from the digital value to the analog value by the D / A converter 26. . Based on the comparison result, APC is performed so that the write power value Pm is constant (the level of the second APC reference voltage signal).

  Based on the APC output from the APC circuit 20, the read power signal generation circuit 21 generates a read power signal VRDC (see FIG. 2B) such that the read power value Pr detected by the FMD 13 is constant. The read power signal VRDC is supplied to the LD driver 14 when the switch 22 is turned on by the LDON signal.

  The write power signal generation circuit 29 is supplied with either the ACC output from the ACC circuit 24 or the APC output from the APC circuit 27 by switching the switch 28. Then, the write power signal generation circuit 29 generates a write power signal VRDC (see FIG. 2B) that makes the write power value Pm detected by the FMD 13 constant based on the ACC output or the APC output. The write power signal VRDC is supplied to the LD driver 14 when the switch 30 is turned on by the PEO signal.

  The integration circuit 31 is configured by, for example, an LPF (Low Pass Filter), and integrates the power monitor signal detected by the FMD 13 when executing correction of an ATT set value described later. The power monitor signal converted into a direct current by the integration is converted from an analog value to a digital value by the A / D converter 32 and supplied to the system controller 15.

  The attenuator 33 (“gain setting unit”) is composed of, for example, a combination of a multi-contact switch and a resistor, and the attenuation rate ATT is set based on the ATT set value supplied from the system controller 15. As a result, in the amplifier 34, the gain is set based on the attenuation factor ATT set by the attenuator 33. Then, the amplifier 34 controls the control signal ΔLDH corresponding to the bias value Δ (FIG. 2 (g)) so that the recording pulse output from the LD 12 satisfies the specified Ph / Pm ratio based on the set gain. Reference). The control signal ΔLDH is supplied to the LD driver 14 when the switch 35 is turned on by the LDH signal.

  The LD driver 14 (“driving unit”) includes a read power signal VRDC supplied from the read power signal generation circuit 21, a write power signal VWDC supplied from the write power signal generation circuit 29, and a control signal ΔLDH supplied from the amplifier 34. Based on the above, the LD 12 is driven. As a result, in the LDH section, a non-multi-pulse recording pulse on which a predetermined bias value Δ is superimposed is output from the LD 12.

<Operation of optical disc apparatus>
Hereinafter, with regard to the operation related to the correction of the ATT set value according to the present invention, first, an operation flow when actually measuring the ATT set value according to a predetermined Ph / Pm ratio in the optical disc apparatus 40 to be corrected will be described. . Next, an operation flow for correcting the ATT setting value corresponding to the optical disc 10 based on the measured ATT setting value and the reference ATT setting value will be described.

=== Measurement of ATT set value ===
Based on the flowchart of FIG. 6, the operation flow when measuring ATT set values (ATT (10), ATT (20)) corresponding to a predetermined Ph / Pm ratio (in the case of 1.1 and 1.2). explain. In the following description, the system controller 15 is the main subject of operation unless otherwise specified.

  First, the optical disc device 40 maintains the focus servo control stop state and adjusts the position of an optical lens (not shown) included in the optical pickup 11 so that the laser beam is not focused on the optical disc 10. . That is, it refers to preprocessing for preventing actual recording when the LD 12 is driven by the following processing.

  In the state as described above, the system controller 15 prevents the bias value Δ from being generated by making the switch 35 non-conductive by the control signal LDH, and sets the read power value Pr (1 mW) to the first APC reference voltage. The signal is supplied to the D / A converter 19 as a signal. As a result, the read power signal generation circuit 21 generates a read power signal VRDC corresponding to the read power value (1 mW). The LD driver 14 drives the LD 12 based on the read power signal VRDC. At this time, the system controller 15 measures the level of the power monitor signal detected by the FMD 13 via the integration circuit 31 and the A / D converter 32. The measured level is stored as “fmd — 1 mW” in a predetermined storage means such as the RAM 16 (S600).

  Further, the system controller 15 supplies the D / A converter 26 with the write power value Pm (10 mW) as the second APC reference voltage signal while maintaining a state in which the bias value Δ is not generated. As a result, the write power signal generation circuit 29 generates a write power signal VWDC corresponding to the write power value (10 mW), and the LD 12 is driven based on the write power signal VWDC. At this time, the system controller 15 measures the level of the power monitor signal detected by the FMD 13 via the integration circuit 31 and the A / D converter 32. The measured level is stored as “fmd — 10 mW” in a predetermined storage means such as the RAM 16 (S601).

  Next, when the system controller 15 superimposes the bias value Δ corresponding to the Ph / Pm ratio 1.1 (10% UP) on the write power value (10 mW), the level of the power monitor signal detected by the FMD 12 Is calculated. As this calculation method, calculation is performed with a calculation formula of “((fmd — 10 mW−fmd — 1 mW) / 10) + fmd — 10 mW” based on “fmd — 1 mW” and “fmd — 10 mW” measured in advance. The calculated result is stored as “fmd — 10UP — 10 mW” in a predetermined storage means such as the RAM 16 (S602).

  Then, the system controller 15 adjusts the ATT setting value so that the level of the power monitor signal actually detected by the FMD 12 becomes the calculated “fmd — 10UP — 10 mW”. The ATT setting value determined as the adjustment result is stored as “ATT (10)” in the ATT setting value storage table 500 of the RAM 16 (S603).

  Next, when the system controller 15 superimposes the bias value Δ corresponding to the Ph / Pm ratio 1.2 (20% UP) on the write power value (10 mW), the level of the power monitor signal detected by the FMD 12 Is calculated. The calculation formula used for this calculation is “((fmd — 10 mW−fmd — 1 mW) / 5) + fmd — 10 mW”, and this calculation result is stored as “fmd — 20UP — 10 mW” in a predetermined storage means such as the RAM 16 (S604).

  Then, the system controller 15 adjusts the ATT set value so that the level of the power monitor signal actually detected by the FMD 12 becomes “fmd — 20UP — 10 mW” calculated. The ATT setting value determined as the adjustment result is stored in the ATT setting value storage table 500 of the RAM 16 as “ATT (20)”.

  As described above, the system controller 15 can measure and obtain “ATT (10)” and “ATT (20)” as data in the ATT set value storage table 500 of the RAM 16. In the embodiment described above, the order of (S600) and (S601) may be changed, or the order of (S602) and (S603) and (S604) and (S605) may be changed. May be.

=== Correction of ATT setting value ===
Based on the flowchart of FIG. 7, an operation flow when correcting the ATT setting value designated according to the type of the optical disc 10 will be described. In the following description, the system controller 15 is the main subject of operation unless otherwise specified.

  First, based on the type information (manufacturer, recording speed, etc.) read from the optical disc 10, the system controller 15 calculates the Ph / Pm ratio x associated with the type information from the strategy table 300 stored in the RAM 16. Determine (S700).

  Then, the system controller 15 reads B_ATT (10) and B_ATT (20) from the reference set information table 400 stored in the RAM 16, and also reads ATT (10) and B_ATT (10) from the ATT set value storage table 500 also stored in the RAM 17. ATT (20) is read (S701).

  Therefore, the system controller 15 uses the correction formula defined as the relationship between B_ATT (10) and B_ATT (20) and ATT (10) and ATT (20) for the Ph / Pm ratio x determined according to the optical disc 10. Substituting and calculating ATT set value y (S702). As this correction formula, for example, “y = (ATT (20) −ATT (10)) × (100x−B_ATT (10)) ÷ (B_ATT (20) −B_ATT (10)) + ATT (10)” And

  Based on the ATT set value y obtained by the above calculation, the attenuation factor ATT of the attenuator 33 is set. As a result, the gain of the amplifier is set, and the optical disc apparatus 40 can drive the LD 12 by superimposing a bias value Δ equivalent to the reference set on the recording pulse in the LDH section.

  The contents of the above-described correction formula will be described in detail with reference to a graph showing the relationship between the ATT setting value and the bias value Δ shown in FIG. In the figure, 800 is a linear interpolation formula defined by B_ATT (10) corresponding to the Ph / Pm ratio 1.1 and B_ATT (20) corresponding to the Ph / Pm ratio 1.2. Reference numeral 810 denotes a linear interpolation formula defined by ATT (10) corresponding to the Ph / Pm ratio 1.1 and ATT (20) corresponding to the Ph / Pm ratio 1.2.

  First, the ATT setting value 100x (100 times x) corresponding to the Ph / Pm ratio x determined according to the optical disc 10 is at a point A on the linear interpolation formula 810. That is, the ATT set value 100x located at the point A indicates one data in the data group of the actually measured ATT set value. At this time, a bias value Δ of Δ (A) is obtained by the ATT set value 100x.

  However, the input / output characteristics of the attenuator 33, the amplifier 34, the LD driver 14 and the LD 12 are inherently non-linear, and it is difficult to uniquely determine their input / output characteristics. Furthermore, there are variations in the elements 33, 34, 14, and 12 themselves, and various characteristics vary depending on ambient environmental conditions such as temperature. For this reason, even if the attenuation rate ATT of the attenuator 33 corresponding to the type of the optical disk is uniquely set by the system controller 96, Δ (A) varies.

  By the way, with respect to the ATT set value 100x, at the point B on the linear interpolation formula 800, Δ (B) is obtained as the bias value Δ. This Δ (B) is a bias value that serves as a model as reference set information. Therefore, for the point C on the linear interpolation formula 810 where Δ (B) is obtained, the ATT setting value at the point C is obtained as y. That is, in the correction formula described above, the point C is obtained from the point A on the linear interpolation formula 810 based on the relationship between the linear interpolation formula 800 and the linear interpolation formula 810, and the ATT setting value after correction is set to the ATT setting value at the point C. It can be the value y.

  As described above, the optical disc apparatus 40 according to the present invention can obtain the same bias value Δ as that of the reference set for the bias value Δ that has been difficult to set uniquely in the past. As a result, any optical disk device 40 has the same ATT setting value versus bias value Δ characteristic as the reference set, and the Ph / Pm ratio can be made constant. Further, by making the Ph / Pm ratio constant, it becomes possible to form a stable recording mark, and it is possible to provide an optical disc apparatus with improved recording quality and a recording control method therefor.

  As mentioned above, although embodiment of this invention was described concretely, it is not limited to this, A various change is possible in the range which does not deviate from the summary.

  For example, in the above-described embodiment, in order to use the linear interpolation formula, the reference ATT set values (B_ATT (10) and B_ATT (20)) and the actually measured ATT set values (ATT (10) and ATT ( 20)) are provided two by two, but the present invention is not limited to this, and a plurality of them may be provided. In this case, the approximation accuracy of the linear interpolation equations 800 and 810 described above is improved by using an approximation algorithm such as a least square method for a large number of data. As a result, the accuracy of the correction formula used when correcting the ATT set value is also improved, and it becomes easier to obtain the corrected ATT set value equivalent to the reference set. That is, a stable recording mark can be formed, and an optical disc apparatus with improved recording quality and a recording control method therefor can be provided.

  Further, in the above-described embodiment, the present invention can be similarly implemented by a multi-pulse system. For example, in the multi-pulse method, a plurality of recording pulse trains are included in the mark section, but a case where a bias value Δ is superimposed on a recording pulse near the head of the recording mark can be considered. In this case, by adopting the technique of making the Ph / Pm ratio constant (that is, making the bias value Δ constant) according to the present invention, a more stable recording mark shape can be obtained and the recording quality can be improved. It will be.

1 is a system configuration diagram of an optical disc apparatus according to an embodiment of the present invention. It is a figure explaining operation | movement of the optical disk apparatus based on embodiment of this invention. It is a figure explaining the content of the strategy table which concerns on embodiment of this invention. It is a figure explaining the content of the reference | standard set information table which concerns on embodiment of this invention. It is a figure explaining the content of the ATT setting value storage table which concerns on embodiment of this invention. 6 is a flowchart for explaining the operation of the optical disc apparatus according to the embodiment of the present invention. 6 is a flowchart for explaining the operation of the optical disc apparatus according to the embodiment of the present invention. It is a figure explaining the correction | amendment of the ATT setting value which concerns on embodiment of this invention. It is a system block diagram of the conventional optical disk apparatus. It is a waveform diagram of a recording pulse when a laser diode is driven in a conventional optical disc apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Optical disk 11 Optical pick-up 12 Laser diode 13 Front monitor diode 14 LD driver 15 System controller 16 RAM 17 Encoder / decoder 18 Sample hold circuit 19 D / A converter 20 APC circuit 21 Read power signal generation circuit 22 Switch 23 D / A converter 24 ACC circuit 25 Sample hold circuit 26 D / A converter 27 APC circuit 28 Switch 29 Write power signal generation circuit 30 Switch 31 Integration circuit 32 A / D converter 33 Attenuator 34 Amplifier 35 Switch 40 Optical disk device 300 Strategy table 400 Reference set information table 500 ATT set value storage table 90 Laser diode 91 LD driver 92 Read power signal generation Circuit 93 switch 94 write power signal generating circuit 95 switches 96 system controller 97 attenuator 98 amplifier 99 switch 100 front monitor diode 101 APC circuit 102 APC circuit 800 linear interpolation formula 810 a linear interpolation formula

Claims (4)

Light emission that emits laser light based on a recording pulse having a read power value, a write power value larger than the read power value, and a bias value superimposed on a predetermined section on the head side in the section of the write power value In an optical disk device for driving an element,
A predetermined first data group serving as a reference of setting data for setting the bias value, and a second data group which is actual measurement data of the setting data corresponding to the first data group. Correct the setting data according to each optical disc based on
Control means for driving the light emitting element by superimposing the bias value set based on the corrected setting data on the write power value;
An optical disc apparatus comprising: The control means includes
An amplifier that generates a control signal for obtaining the bias value based on a set gain;
A gain setting unit for setting the gain of the amplifier based on the setting data;
A drive unit that drives the light emitting element by superimposing the bias value according to the control signal on the write power value;
The first data group serving as a reference for the setting data corresponding to the plurality of bias values, and the setting data measured when the light emitting element is driven by designating the plurality of bias values. Storage means for storing two data groups;
Correspondence between the first data group and the second data group is calculated, and based on the correspondence, the bias value corresponding to each optical disc on the second data group side is the first data group. Correction means for correcting the setting data according to the optical disc so as to be the bias value on the data group side of
The optical disc apparatus according to claim 1, further comprising: The first data group includes data A serving as a reference for the setting data corresponding to the first bias value and a reference for the setting data corresponding to the second bias value that is greater than the first bias value. Data B
The second data group includes data C that is actual measurement data of the setting data corresponding to the first bias value, and data D that is actual measurement data of the setting data corresponding to the second bias value. And
The correspondence is
When the setting data before correction is X and the setting data after correction is Y, it is determined by “Y = ((C−D) × (X−A)) ÷ (B−A) + A”. The optical disc device according to claim 2, wherein the optical disc device is provided. Light emission that emits laser light based on a recording pulse having a read power value, a write power value larger than the read power value, and a bias value superimposed on a predetermined section on the head side in the section of the write power value In a recording control method of an optical disk device for driving an element,
The setting data for setting the bias value according to the optical disc is a first data group used as a reference for the setting data, and a second data that is actually measured data of the setting data corresponding to the first data group. Correction based on the data group,
Driving the light emitting element by superimposing the bias value set based on the setting data after the correction on the write power value;
A recording control method for an optical disc apparatus, comprising:

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