TWI363341B - Writing power calibrating method and information recording apparatus - Google Patents

Description

1363341 ——: __ 100 years. December 06, according to the replacement page 6. Description of the invention: [Technical field of invention] [0001] The present invention relates to an information recording apparatus, and more particularly to a write power correction of an information recording apparatus method. [0002] • Reference [Prior Art] In recent years, information recording media such as rewritable optical discs (DVD_RW4CD_RW) have been used as a carrier for recording information, and are increasingly used due to their large storage capacity and portability. The information recording device for recording information to the information recording medium is welcomed by the user because it can provide the user with self-burning information. The corresponding information recording technology has also developed rapidly. Generally, the information recording device uses an optical pick-up unit (〇pu) to emit a laser beam to the information recording medium. When the output laser power reaches a given value, the laser will cause the information. The state of a particular location on the recording medium changes to form a record mark. Thus, the information is recorded on the -Bei recording medium. When the output laser power reaches another given value, the laser restores the changed position on the information recording medium to the original state, thereby erasing the recording mark formed on the information recording medium. [0003] Since the formation of the recording mark depends on the intensity of the laser, the laser power must be corrected before the information is recorded to the information recording medium to ensure the correctness of the recording. Thunder (four) degree H writes the level of human material, secret material level and reading material level. Its t, the laser intensity when writing the human-level finger-shaped silk mark, the erasing power level refers to the laser intensity when the recording mark is erased, and the reading power level refers to the lightning when reading information from the information recording medium. 095126685 Form No. A0101 Page 3 / Total 28 Page 1003451356-0 1363341 [0004] [0006] [0007] [0008] [0009] [0010] 095126685 | 100 years of December shot intensity. Usually when performing power correction, the read power is also referred to as the power. The erase power level and the read (offset) power level can be automatically corrected by their respective automatic power control (APC) loops. Each apc loop is connected to a front monitor diode (FMD) by a saraple/hold circuit, receives the signal of the reflected laser intensity output by the FMD, and adjusts the laser according to the signal. strength. However, there is no dedicated APC loop to adjust the write laser intensity. Generally, the information recording device stores a plurality of default erasing power values and a ratio of erasing power to writing power, and the adjustment of the writing laser intensities is adjusted according to the ratio of the erasing power value to the erasing power. However, write power typically requires multiple adjustment calculations, and the accuracy of the adjustment is also difficult to control. SUMMARY OF THE INVENTION In view of the above, it is necessary to provide a write power correction method. Further, & an information recording apparatus using a write power correction method, a write power correction method 'includes the following steps: determining a target value of a pre-monitoring diode output signal; controlling a laser diode output by a special a waveform, the special waveform includes an erase power level and a write power level, wherein the sum of the durations of the erase powers is equal to the sum of the durations of the write powers; and the plurality of samples of the monitor output signals are multi-sampled The sampled value is averaged; the watch number A0101 帛 4 pages / a total of 28 pages

, and more than 1003451356-0 1363341 [0011] 100 years. December 06 correction replacement page Adjust the write power until the average value of the sampled value is equal to the target value. [0012] An information recording apparatus comprising: a laser diode for emitting a laser to a recording medium to record information to the recording medium, for driving the lightning-emitting diode to emit a laser A diode driver and a digital signal processor for controlling the length of time that the laser diode emits laser light. The digital signal processor sends a command to the laser diode to cause the laser diode to emit a laser power having a predetermined waveform, the laser power having a predetermined waveform including alternate writing The power level and the erasing power level, the length of time each occurrence of the write power level is equal to a corresponding high level duration of one of the eight to fourteen modulated signals to be φ burned. [0013] The above write power correction method and the information recording device use a special waveform in the power correction process to replace the general waveform, reduce the probability of occurrence of overshoot in the waveform, and reduce the accuracy of the overshoot amount to the write power correction. Sexual adverse effects and simplify the amount of calculations in the power calibration process. [Embodiment]

Referring to FIG. 1, an information recording apparatus 1 according to a first embodiment of the present invention includes an OPU 10, a digital signal processor (DSP) 12, and an analog signal processor (ASP) 14. 0PU 10 Includes laser diode driver (LDD) 100, LD 102 and FMD 104. [0015] The LDD 100 is used to drive the LD 102 to emit laser light. Please also refer to FIG. 2, which is a general waveform diagram of the laser power output of the exemplary LD 102. The power level of the light includes three power levels: Pw, Pe and Pb. 095126685 Form No. A0101 Page 5 of 28 1003451356-0 1363341 100 years. December 06 Shuttle replacement page When the laser power is PW, the information is recorded on the information recording medium; when the laser power is When Pe is used, the information recorded on the information recording medium is erased; when the laser power size is Pb, the information recorded on the information recording medium is read. [0016] The FMD 104 is used to monitor the intensity of the laser light emitted by the LD 102 and output an FMD signal to the DSP 12 and the ASP 14. Please also refer to FIG. 3, which is a diagram of the relationship between the laser power outputted by the LD 102 and the FMD signal.

When the laser power output by the LD 102 is lower than a given value N, the FMD 104 outputs a constant voltage value; when the laser intensity output by the LD 102 is greater than a given value N, the voltage value output by the FMD 104 follows the LD 102. The output laser power increases and decreases. Corresponding to the three power levels output by LD 102, the output of FMD 104 also has three corresponding FMD signal values FMDdw, FMDd, and FMDd (as shown in Figure 4).

Pb Pe Pw

[0017] The DSP 12 is used to control the length of time for the laser to be transmitted by the 1 0 0 100 (ie, the length of each power level in the waveform of FIG. 2) and the operation of the ASP 14 including an analog-to-digital converter (analog-to -digital converter, ADC) 120. The ADC 120 is coupled to the FMD 104 for sampling the FMD signals output by the FMD 104. The ASP 14 is used to control the amount of laser power that the LDD 100 drives the LD 102 output. 0PU 10, DSP 12 and ASP 14 together form an APC loop. In the APC loop, the DSP 12 controls the ASP 14 to drive the 0PU 10 to emit a laser beam of a specified power, and the 0PU 10 feeds back the FMD signal to the ASP 14, and the ASP 14 adjusts the power of the laser beam according to the FMD signal. [0018] The information recording apparatus 1 further includes a storage unit 16. Storage unit 16 095126685 Form number A0101 Page 6 of 28 1003451356-0 Can be Na __, 翔 存 存 存 ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ Burnt dryness (ε = Pe/Pw) 2. Since the intrinsic attribute difference of the information recording medium produced by each information recording agent is 'the function of the light irradiated onto the information recording medium, the heart M is adjusted accordingly to conform to the intrinsic property of each information recording medium. In order to facilitate the recording of information to various information recording media, the recording device (4) will produce the registered power for the major information recording media. These scheduled burns

2 stored in the burning strategy table (10), when the information recording device i opened ° ° recorded Beixun, 0PU 10 from the information recording medium to read the information of the information = record f attribute (this information is usually recorded in the information record The information recording device obtains default Pe and ε values matching the information recording medium based on the information search burning strategy table read from the information recording medium. [0019]

12 Send the command to the LDD according to the contents of the programming policy table (10). LD 1〇2 ι_χ controls the length of time for the lasers that emit the power levels. [0020] Please refer to the figure e, a for an example of the APC loop circuit diagram. ASP 14 i includes two 4 knives, partly for reading information from the information recording medium, and partly for recording information to the information recording medium. Each part includes a digital-to-analog converter (digitai_anal〇g) connected to the DSP 12.

Converter, DAC) 14〇, a subtractor 142, and a sample/hold (sample/h〇ld' S/H) unit connected to the FMD 1〇4 via the amplifier 106. The l44° DAC 140 is used to receive the DSP 12 And output the specified voltage. The output signal of the FMD 1〇4 output is 095126685 Form No. AO101 笫7 pages/Total 28 pages 1003451356-0 1363341 December 6, 100 Correction Replacement Page The amplifier 106 is amplified and transmitted to the S/H 144. The S/H 144 samples the amplified FMD signal to provide an appropriate signal for the subtractor 142 to perform the subtraction. DSP 12 controls the operation of S/H 144 or not

. The subtracter 142 subtracts the output voltage of the DAC 140 from the FMD signal fed back by the FMD 104 to obtain an error signal amplified by an amplifier (AMP) into a driving signal output to the LDD 100 to adjust the power of the laser emitted by the LD 102. The driving signals generated in the ASP 14 include a first driving signal CH_A, a second driving signal CH_W, and a third driving signal CH_R. The first driving signal CH_A is used to adjust the size of the Pw, the second driving signal CH_W is used to adjust the size of the Pe, and the third driving signal CH_R is used to adjust the size of the Pb. The third driving signal CH_R is a product of the second driving signal CH_W and a gain value. The three drive signals are transmitted to the LDD 100 through their respective transmission channels, amplified by a corresponding amplifier (not shown), and output to an accumulator (not shown). The accumulator accumulates the three driving signals and outputs them to the LD 102 to drive the LD 102. Please also refer to Figure 6, Pw is the sum of the three drive signals (ie (G(CH_A), G(CH_W), G(CH_R)), where G(X) is the gain function of each amplifier), Pe is the second The sum of the drive signal CHj and the third drive signal CH_R (ie, (G(CH_W), G(CH_R)))), and Pb is G(CH_R). [0021] Since the second driving signal CH_W and the third driving signal CH_R have corresponding APC loop control, the first driving signal CH_A is the product of the second driving signal CH_W and a gain value, and Pw is the sum of the three driving signals. Value, so the gain value can be adjusted by adjusting the gain value 145. 095126685 Form No. A0101 Page 8 of 28 1003451356-0 1363341 [100 years. December 06th] _ page [0022] - The usual gain value adjustment process is as follows: First, j) Sp 12 controls LDD 100 Sending a driving voltage to drive ld 102 to output a predetermined waveform;

Next, the ADC 120 of the DSP 12 samples the FMD signal output by the FMD 104 multiple times (usually more than one thousand times) to obtain a plurality of FMD signal values. Then, averaging multiple FMD signal values yields an average value of FMDA. Then, according to the obtained values, the relationship between FMI)Ave, Pe and ε is plotted (the relationship between an exemplary FMDA„p, Pe and ε is shown in Fig. 7), and the relationship curve is saved. In the information recording apparatus 1, as a subsequent power correction reference. When the power is subsequently corrected, a set of corresponding pe and ε values are obtained from the programming strategy table 160 according to the information recording medium information, and then according to the set pe and ε. The value and the above FMDAV (the relationship between j, pe and ε obtain a corresponding FMDivp value. The FMD_ is a target value.

AVG AVG

The rear DSP 12 controls the LDD 100 to issue a driving voltage to drive the LD 102 to output the predetermined waveform and to sample the FMD signal output by the FMD 104 multiple times (usually more than one thousand times) to obtain a plurality of FMD signal values. Then, averaging the plurality of FMD signal values to obtain an average value fmdAV (;, comparing the fmdAV6 value with the target value, if the two are equal, the adjustment ends, if not equal, continuing to adjust the gain value 145 until two [0023] However, due to the difference in intrinsic properties of different LDs 102, different waveforms are generated under the same driving command. In fact, the waveform shown in Figure 2 is an ideal waveform diagram, the actual waveform diagram. Because of the optical characteristics of LD 102, the overshoot will occur during power switching. As shown in Figure 8, when Pe is switched to or Pw is switched to Pb, there will be a certain degree of 095126685 Form No. A0101 Page 9 of 28. 1003451356-0 1363341 On December 06, 100, according to the positive replacement page, the amount of overshoot generated by the different LD 102 is different. The waveform A) and the waveform b) are two different LDs 102 under the same drive command. The waveform that is rotated. Obviously, the overshoot in waveform B) is greater than in waveform A). Since the output signal of the FMD 104 depends on the laser intensity output by the LD 102, the FMD signal output by the F〇 1〇4 also produces an overshoot. Therefore, the fmda1,p calculated in the above process

The A VG value is also greatly affected by the presence of overshoot. When the information recording device uses different LD 1〇2, between FMDA„r'Pe and ε

The A VG relationship curve needs to be rebuilt. In addition, due to the presence of overshoot, the FMDAVG deviates too much from the theoretical value, which may cause the correction accuracy of Pw to decrease.

[0024] In order to reduce the difference in overshoot caused by the different intrinsic properties of different LDs 1〇, a special waveform is dedicated to correct pw. This special waveform reduces the probability of overshoot occurring compared to a normal waveform. As shown in Figure 9, it is a comparison of special waveforms and general waveforms. Usually, the information to be burned is first converted into an eight-to-fourteen modulate (EFM) data, which is also represented as an EFM waveform. The switching point between the high level (also called "pit") and the low point level (also called "land") in the EFM waveform represents a "1". Each "pi t" characterizes a record mark recorded on the information recording medium. In a typical waveform, there is one or more pulses (ie, Pw) for each "pit" in the EFM waveform, and there is only one pulse in the special waveform. That is, the length of time in which the Pw appears in the special waveform is the length of the "pit" in the EFM waveform. Since the number of occurrences of Pw in the special waveform is less than that in the general waveform, the probability of occurrence of the overshoot is also reduced accordingly, so that the overshoot amount is FMDAV (; value 095126685 Form No. A0101 Page 10 / Total 28 Page 1003451356-0 丄 341 100 On December 06, the effect of the shuttle on the ^ page will also be low. tW) 25] Only two power levels (pw and pe) exist in the special waveform, and the corresponding FMD signals have only two values, FMD and FMD. usually,

Pw Pe In the EFM waveform, the length of all "Pit" is equal to the length of "land", that is, the period ratio of "pit" to "iand" is 50%. Therefore, the lengths of Pw and Pe in the special waveform are also equal, and the lengths of FMD and FMD appear equal. Thus, the value of FMd is

Re AVG

FMDp^ FMDp/average. Correspondingly, the calculation of the FMDm target value and the calculation of the fmdavg value during the correction process are greatly simplified. Please refer to FIG. 1A, which is a flowchart of a write power correction method according to a preferred embodiment of the present invention. T〇〇27] First, in step 60, two different FMD signal values are obtained. The LDD 100 is controlled by the DSP 12 to drive the LD 102 to emit the stable DC powers PW_DC1 and PW_DC2 which have been measured by the production tool, and then the ADCs 120 of the DSP 12 respectively obtain the FMD signal values (FMDDC1 and FMDDC2) at each power.

[〇〇28] Next, in step 62, a set of values of Pe and ε are read from the burn strategy table 160. And the value of Pw is obtained from the values of Pe and ε. [0029] Next, in step 64, the relationship between the FMD signal and the voltage value is obtained according to FMDDC1 and FMDDC2, and then the obtained in step 62 is obtained by interpolation.

The FMD signal value (FMDd and FMDd) corresponding to Pe and Pw. Re Γ w [0_ Then, in step 66, calculate FMDAV according to the equation FMDTeT=(FMDpe+ FMDpw )/2 (^ S scalar FMDT(;T. 095126685 Form No. A0101 Page 11 of 28, 1003451356-0 1363341 On December 06, 100, the replacement page [0031] Then, in step 68, the DSP 12 issues a command to control the LDD 100 to drive the LD 102 to output the special waveform in Figure 9. [0032] Next, 'Step 61, the ADC 120 pairs the FMD signal. Multiple sampling (preferably more than - thousand times) is performed to obtain a plurality of FMD signal values, and the plurality of FMD signal values are averaged to obtain a value of FMD.

A VG

[0033] Next, in step 612, it is determined whether the FMD is equal to the calculation in step 66.

A VG calculated FMDT (; T value. [Wake] If the judgment result in step 612 is FMD is not equal to step 66

What is A VG calculated? ^1〇11(;11 value, adjust by adjusting the gain value 145 _

The size of Pw is then returned to step 68 (step 614). [0035] If the result of the determination in step 612 is !^!) equal to the FMDm value calculated in step 66 of AV, the pw adjustment is completed, and the DSP 12 controls the LDD 1 to drive the LD 102 to output the general Waveform for recording information.

[0036] In the above write power correction method, the probability of occurrence of the FMD signals FMD and FMD sampled by the ADC 120 is reduced as much as possible.

For the ic I W phenomenon, the timing for outputting a special waveform is preferably 2 times the standard programming speed. In addition, to further reduce the amount of overshoot on FMD,,,. The effect of the value,

A VG can add a low pass filter 18 between ADC 120 and FMD 104 (shown in Figure 11). [0037] In summary, the present invention complies with the requirements of the invention patent, and submits a patent application according to law. However, the above description is only the preferred embodiment of the present invention, and those skilled in the art will be able to include the equivalent modifications or variations in the spirit of the present invention. 095126685 Form number detail 1 Page 12 / 28 pages 1003451356-0 136.3341 • ΙΟΟ 年 . 12 12 12 12 12 12 12 12 12 12 【 【 【 【 【 【 【 【 【 【 【 【 【 【 【 【 【 【 【 【 【 资讯 资讯 资讯 资讯 资讯 资讯 资讯 资讯 资讯 资讯 资讯 资讯A block diagram of the device, the information recording device comprising a laser diode (LD) and an FMD. 2 is a general waveform of the LD output of FIG. 1, which includes three power levels: write power level (Pw), erase power level (Pe), and bias power level (Pb). 3 is a graph showing the relationship between the laser intensity of the LD output of FIG. 1 and the output signal of the FMD.

4 is a comparison diagram of an output waveform of an LD and an output waveform of an FMD. 5 is a circuit diagram of an APC loop of the information recording apparatus of FIG. 1. 6 is a structural analysis diagram of three power levels in FIG. 2. 7 is a graph showing the relationship between the average value of the output signals of the exemplified FMD and the ratio of Pe to Pw (ε). [0045] FIG. 8 is a waveform alignment diagram of different LD outputs.

9 is a comparison diagram of a special waveform of the present invention and a general waveform of FIG. 2. 10 is a flow chart of power correction of a write power correction method in accordance with a preferred embodiment of the present invention. 11 is a block diagram of an information recording apparatus according to a second embodiment of the present invention. [Main component symbol description] [0049] Information recording device: 1 [0050] ASP: 14 095126685 Form number A0101 Page 13 of 28 1003451356-0 1363341 [0051] OPU : 10 [0052] DAC : 140 [0053] LDD : 100 [0054] Subtractor: 142 [0055] LD : 102 [0056] S / Η unit: 144 [0057] FMD : 104 [0058] Gain value: 145 [0059] DSP : 12 [0060] Storage unit: [0061] ADC: 120 [0062] Burning Strategy Table: 160 [0063] LPF: 18 [0064] 60~616: Burning Power Correction Method Flow Step 095126685 Form No. A0101 Page 14 of 28 .December 06 revised replacement page 1003451356-0

Claims (1)

1363341 100 years. December 06, the nuclear ridges page 7, 1 * Patent scope: A write power correction method, including the following steps: Determine the target value of a pre-monitoring diode output signal; The emitter diode outputs a laser power having a special waveform including only the erased power level and the write power level that alternately appear, wherein the sum of the duration of the erase power and the write power The sum of the durations is equal; the pre-monitoring diode output signal is sampled multiple times, and the plurality of sampled values are averaged; the reference write power level is adjusted until the average value of the sampled values is equal to the target value写入2 #3. The write power correction method according to claim 1, further comprising the steps of: calculating a pre-monitoring diode output signal value corresponding to a given erasing power level; Pre-monitoring diode output signal value at a given write power level; determining the target value as the pre-monitoring corresponding to the given erase power level The diode output signal value is an average of the value of the pre-monitor diode output signal corresponding to the given write power level. The write power correction method according to claim 2, wherein the given erase power level is obtained by querying a burn strategy table by information of a CD to be burned, the given write power The rating is calculated by the given erase power level and the ratio of the erase power level to the write power level defined in the burn strategy table. 095126685 Form No. A0101 Page 15 of 28 1003451356-0 1363341 The writing power correction method according to claim 1, wherein the writing power is The duration of the level is equal to the duration of the still level of the eight to fourteen modulated signals to be programmed. 5. The write power correction method according to claim 1, wherein the write timing of the special waveform is twice the standard burn speed. 6. An information recording device, comprising for emitting a laser to a recording medium for recording a laser diode for driving the recording medium, and a laser diode driver for driving the laser diode for controlling the length of time that the laser diode emits laser light The digital signal processor is improved in that the digital signal processor can send a command to the laser diode driver to drive the laser diode to output a laser power having a predetermined waveform, the predetermined The laser power of the waveform includes only the alternate write power level and the erase power level. The length of each occurrence of the write power level is consistent with a high level of one of the eight to fourteen modulated signals to be burned. The length of time is equal. 7. The information recording apparatus according to claim 6, wherein said The sum of the duration lengths of the erase power levels is equal to the sum of the durations of the write power levels. 8. The information recording apparatus of claim 6, wherein the special waveform is used in a laser power correction process. 9. The information recording apparatus according to claim 6, wherein the writing timing of the special waveform is twice the standard burning speed. 10. The information recording apparatus according to claim 6, further comprising an analog signal processor, configured to receive a command from the digital signal processor to generate a driving signal to be sent to the laser diode driver The laser diode outputs a laser power of a particular magnitude. 095126685 Form No. A0101 Page 16 of 28 1003451356-0 1363341 11 12 14 The information recording device according to claim 10, further comprising a pre-monitoring diode for monitoring the power output of the laser diode and Outputting a monitoring signal reflecting the power level of the output of the laser diode to the analog signal processor, wherein the analog signal processor controls the output power of the laser diode according to the monitoring signal . The information recording apparatus according to claim 11, wherein the correction of the write power level is performed by a plurality of pre-monitoring signals measured when the laser diode outputs a laser power having a predetermined waveform. The average is equal to a given target value. The information recording device according to claim 12, wherein the target value is an average value of a first pre-monitoring signal and a second pre-monitoring signal, and the first pre-monitoring signal is a laser The diode outputs a signal value of the pre-monitoring diode output measured at a given erasing power, and the second pre-monitoring signal is when the laser diode output is given a given write The signal value of the pre-monitoring diode output measured by the power time. The information recording apparatus of claim 13, further comprising a programming policy table for recording a ratio of the plurality of sets of erasing power level values to the erasing power level to the writing power level. The information recording apparatus of claim 14, wherein the given erasing power is read from a programming policy level, the given writing power level being based on the given erasing power level Calculated from the corresponding ratio value in the burn-in strategy table. 095126685 Form No. A0101 Page 17 of 28 1003451356-0