CN101105954B

CN101105954B - Writing capability correction method and information recording device

Info

Publication number: CN101105954B
Application number: CN200610061654A
Authority: CN
Inventors: 陈荣池
Original assignee: Hongfujin Precision Industry Shenzhen Co Ltd; Hon Hai Precision Industry Co Ltd
Current assignee: Hongfujin Precision Industry Shenzhen Co Ltd; Hon Hai Precision Industry Co Ltd
Priority date: 2006-07-14
Filing date: 2006-07-14
Publication date: 2012-08-29
Anticipated expiration: 2026-07-14
Also published as: CN101105954A

Abstract

The method relates to a writing power correction method of information recording device. The writing power correction method controls a laser dioxide to generate a special wave to replace the traditional wave in the process of power correction. The special wave includes the erasure power grade and writing power grade that appear alternatively, wherein, the total lasting time of the erasure power is equal to that of the writing power, thus simplifying the target value calculation in the process of writing power correction. Meanwhile, through the reduction of overshoot times, the invention can lower overshoots' negative impact on the accuracy of writing power correction.

Description

Writing capability correction method and information record carrier

Technical field

The present invention relates to a kind of information record carrier, relate in particular to a kind of Writing capability correction method of information record carrier.

Background technology

In the last few years, can override the carrier of type laser disc information recording carriers such as (DVD-RW or CD-RW), and reach characteristics such as portability owing to its memory capacity greatly and obtain use more and more widely as recorded information.Be used for the information record carrier of recorded information to information recording carrier, owing to providing the autonomous imprinting information of user to receive user's welcome.Corresponding information recording technique has also obtained development rapidly.Usually; Information record carrier adopts optical pick-up unit (optical pick-up unit; OPU) sending beam of laser converges on the information recording carrier; When the luminous power of output when reaching a set-point, laser can make that the state of ad-hoc location changes on the information recording carrier, to form a record mark (mark).Thereby information is recorded on the information recording carrier.And when the luminous power of output reached another set-point, laser can make the location restore original state that changes on the information recording carrier, thereby wipes the record mark that is formed on the information recording carrier.

Because the formation of record mark depends on the intensity size of laser, therefore, before recorded information to information recording carrier, must carry out the correction of luminous power, with the correctness of guaranteeing to write down.Usually, being used for the laser of recorded information comprises three laser intensity grades: Writing power grade, erase power grade and readout power grade.Wherein, the laser intensity when Writing power grade finger-type becomes record mark, the laser intensity when the erase power grade refers to wipe record mark, and the readout power grade refers to the laser intensity when information recording carrier reads information.Usually when carrying out capability correction, readout power also is called as bias power.The erase power grade with read (biasing) power grade and can the automated power through separately control that (automatic power control, APC) carry out from NMO correction in the loop.Each APC loop adopts a sampling/maintenance (sample/hold) circuit to be connected to a preposition monitor diode, and (front monitor diode FMD), receives the signal of the reaction laser intensity of FMD output, and adjusts laser intensity according to this signal.But, do not have special APC loop to be used for adjusting and write laser intensity.Usually, the information record carrier internal memory contains some acquiescence erase power values, and the rate value of erase power and Writing power, and the adjustment that writes laser intensity is adjusted according to the ratio of erase power value and erase power.

Yet Writing power needs adjustment repeatedly to calculate usually, and the also difficult control of the precision of adjustment.

Summary of the invention

In view of this, be necessary to provide a kind of Writing capability correction method in fact.

In addition, a kind of information record carrier that uses Writing capability correction method is provided.

A kind of Writing capability correction method comprises the steps:

Confirm the desired value of a preposition monitor diode output signal;

Control a laser diode and export a special waveform, this special waveform includes only erase power grade and Writing power grade, and wherein the duration summation of erase power equates with the duration summation of Writing power;

Said preposition monitor diode output signal is repeatedly sampled, and sampled value is repeatedly averaged;

The adjustment Writing power equates with said desired value up to the mean value of sampled value.。

A kind of information record carrier; Comprise and be used to send the laser diode of laser to recording medium with recorded information to said recording medium; Be used to drive the laser diode drive that said laser diode sends laser, and be used to control the digital signal processor that laser diode sends the time span of laser.Said digital signal processor sends a command to said laser diode; So that said laser diode sends a predetermined waveform; Said predetermined waveform includes only Writing power grade and the erase power grade that alternately occurs, and the time span and of the each appearance of Writing power grade is treated the corresponding high level lasting time equal in length in eight to 14 modulation signals of imprinting.

Above-mentioned Writing capability correction method and said information record carrier; In the capability correction process, adopt a special waveform to replace general waveform; Reduce the possible occurrence probability of overshoot in the waveform; Reduce the harmful effect of overshoot, and simplify the calculated amount in the capability correction process the accuracy of Writing capability correction.

Description of drawings

Fig. 1 is the block scheme of the first embodiment information record carrier of the present invention, and information record carrier comprises a laser diode, and (laser diode is LD) with a FMD.

Fig. 2 is the general waveform of LD output among Fig. 1, and this general waveform comprises three power grades: Writing power grade (Pw), erase power grade (Pe) and bias power grade (Pb).

Fig. 3 is the graph of relation between the output signal of laser intensity and FMD of LD output among Fig. 1.

Fig. 4 is the APC loop circuit figure of information record carrier among Fig. 1.

Fig. 5 is the output waveform of LD among Fig. 4 and the output waveform map of FMD.

Fig. 6 is the structure elucidation figure of three power grades among Fig. 2.

Fig. 7 is that mean value and the Pe of output signal of a kind of illustrative FMD is to graph of relation between the ratio (ε) of Pw.

Fig. 8 is the waveform comparison figure that different LD exports.

Fig. 9 is the comparison diagram of the general waveform among special waveform of the present invention and Fig. 2.

Figure 10 is the capability correction process flow diagram of the Writing capability correction method of the present invention's one preferred embodiment.

Figure 11 is the block scheme of second embodiment of the invention information record carrier.

Embodiment

Please referring to Fig. 1, the first embodiment information record carrier 1 of the present invention comprises OPU 10, digital signal processor (digital signal processor, DSP) 12 and analogue signal processor (analog signal processor, ASP) 14.OPU 10 comprises laser diode drive (laser diode driver, LDD) 100, LD 102 and FMD 104.

LDD 100 is used to drive LD 102 and sends laser.Please be the general oscillogram of the luminous power of illustrative LD 102 outputs simultaneously referring to Fig. 2.The watt level of light comprises three power grade: Pw, Pe and Pb.When the luminous power size was Pw, information was recorded on the information recording carrier; When the luminous power size was Pe, the information that is recorded on the information recording carrier was wiped free of; When the luminous power size was Pb, the information that is recorded on the information recording carrier was read.

FMD 104 is used to monitor the laser intensity that LD 102 sends and exports a FMD signal to DSP 12 and ASP 14.Please be simultaneously referring to Fig. 3, it is the luminous power of LD 102 outputs and the graph of a relation of FMD signal.When the luminous power of LD 102 output is lower than a set-point N, the magnitude of voltage that FMD 104 outputs one are constant; When the laser intensity of LD 102 output during greater than set-point N, the magnitude of voltage of FMD 104 outputs increases with the luminous power of LD 102 outputs and successively decreases.Three power grades of corresponding LD 102 outputs, the output of FMD 104 also has the FMD signal value FMD of three correspondences _PB, FMD _PE, with FMD _PW(as shown in Figure 5).

DSP 12 is used for controlling LDD 100 driving LD 102 and sends the time span (being the length of each power grade of Fig. 2 waveform) of laser and the running of ASP 14, and it comprises analog to digital converter (analog-to-digital converter, ADC) 120.ADC 120 links to each other with FMD 104, is used for the FMD signal of FMD 104 outputs is carried out sampling processing.ASP 14 is used to control the luminous power size that LDD 100 drives LD 102 outputs.OPU 10, DSP 12 and the ASP 14 common APC loops of forming.In the APC loop, DSP 12 control ASP 14 drive the laser beam that OPU 10 sends specified power, and OPU 10 feedback FMD signals are to ASP 14, and ASP 14 is according to the watt level of this FMD signal adjustment laser beam.

Information record carrier 1 also comprises storage unit 16.Storage unit 16 can be read-only flash memory, and it is used to store write-in policy table 160.Write-in policy table 160 records many group Pe and the ε (value of ε=Pe/Pw).Because each information recording carrier manufacturer information recording carrier inherent attribute difference separately of being produced, the power that shines the light on the information recording carrier also must corresponding adjustment to meet the inherent attribute of each information recording carrier.Usually, to various information recording carrier, information record carrier manufacturer can set a predetermined recording power for the information recording carrier of each main information recording carrier manufacturers produce for ease of recorded information.These predetermined recording powers all are stored in the write-in policy table 160.Before information record carrier 1 opening entry information; OPU 10 reads the information (these information are recorded in the Lead-In Area of information recording carrier usually) of reacting this information recording carrier attribute from information recording carrier, and information record carrier is according to acquiescence Pe and the ε value of the information search write-in policy table acquisition of reading from information recording carrier with this information recording carrier coupling.

DSP 12 sends a command to LDD 100 driving LD 102 send the laser of each power grade with control time span according to the content of write-in policy table 160.

Please be an illustrative APC loop circuit figure simultaneously referring to Fig. 4.ASP 14 comprises two parts, and a part is used for reading information from information recording carrier, and another part is used for recorded information to information recording carrier.Each part all comprise one link to each other with DSP 12 digital to analog converter (digital-analog converter, DAC) 140, one subtracters 142, and the sampling/maintenance that links to each other through an amplifier 106 with FMD104 (sample/hold, S/H) unit 144.DAC 140 is used to receive order and the output given voltage of DSP 12.The FMD signal of FMD 104 outputs is sent to S/H 144 after amplifier 106 amplifies.FMD signal after 144 pairs of amplifications of S/H is sampled to provide appropriate signals to let subtracter 142 carry out subtraction.Whether the running of DSP 12 control S/H 144.The FMD signal that subtracter 142 deducts FMD 104 feedbacks with the output voltage of DAC 140 obtains error signal and is enlarged into the drive signal that exports LDD 100 to through amplifier (AMP), the watt level of the laser that sends with adjustment LD 102.The drive signal that produces in the ASP 14 comprises the first drive signal CH_A, the second drive signal CH_W, and the 3rd drive signal CH_R.Wherein, the first drive signal CH_A is used to adjust the size of Pw, and the second drive signal CH_W is used to adjust the size of Pe, and the 3rd drive signal CH_R is used to adjust the size of Pb.The 3rd drive signal CH_R is the product of the second drive signal CH_W and a yield value.Three kinds of drive signals transmission channel through separately respectively are sent to LDD 100, and after corresponding amplifier (indicating) amplifies, export a totalizer (indicating) to.Totalizer carries out three kinds of drive signals to export LD 102 to drive LD 102 after the accumulation process.Please be simultaneously referring to Fig. 6, Pw be three kinds of drive signals and value (be ∑ (G (CH_A), G (CH_W); G (CH_R)), wherein G (X) shows each Amplifier Gain function), Pe be the second error signal CH_W and the 3rd error signal CH_R's and value (be ∑ (G (CH_W); G (CH_R))), Pb is G (CH_R).

Because the second drive signal CH_W has corresponding APC circuit controls with the 3rd drive signal CH_R; And the first drive signal CH_A is the product of the second drive signal CH_W and a yield value; And Pw be three kinds of drive signals and value, therefore can adjust the size of Pw through adjustment yield value 145.

A kind of common yield value adjustment flow process is following: at first, DSP 12 control LDD 100 send driving voltage and drive LD 102 outputs one predetermined waveform; Then, the ADC120 of DSP 12 to the FMD signal of FMD 104 output repeatedly sample (usually above 1,000 times) obtain a plurality of FMD signal values.Then, a plurality of FMD signal values are asked on average obtained a mean value FMD _AVGThen, draw FMD according to the value that obtains _AVG, relation curve (a kind of illustrative FMD between Pe and the ε three _AVG, the relation curve between Pe and the ε three is as shown in Figure 7), relation curve is stored in the information record carrier 1, with as the subsequent power calibration reference.During follow-up corrected power, obtain one group of corresponding Pe and the value of ε according to information recording carrier information from write-in policy table 160 earlier, organize value and the above-mentioned FMD of Pe and ε then according to this _AVG, Pe and relation curve between the ε three obtain a corresponding FMD _AVGValue.This FMD _AVGBe a desired value.DSP 12 control LDD 100 send driving voltage and drive the above-mentioned predetermined waveform of LD 102 outputs then, and the FMD signal of FMD 104 outputs is repeatedly sampled (usually above 1,000 times), obtain a plurality of FMD signal values.Then, a plurality of FMD signal values are asked on average obtained a mean value FMD _AVG, with this FMD _AVGValue and above-mentioned desired value compare, if both equate that then adjustment finishes, if unequal, then continue adjustment yield value 145 and equate up to both.

Yet because different LD 102 inherent attribute differences, it can produce different waveforms under same driving order.In fact, waveform shown in Figure 2 is a kind of desirable oscillogram, can be because the optical characteristics of LD 102 produces overshoot when power switches in the actual oscillogram.As shown in Figure 8, switch to Pw or Pw when switching to Pb at Pe, have overshoot to a certain degree.The overshoot that different LD 102 produces varies in size.Waveform A among the figure) with waveform B) be the waveform of two different LD 102 output under identical driving order.Obviously, the overshoot waveform B) is greater than waveform A) in.Because the output signal of FMD 104 depends on the laser intensity of LD 102 outputs, the FMD signal of FMD 104 outputs also can produce overshoot equally.Therefore, the FMD that calculates in the above-mentioned flow process _AVGValue also receives very big influence because of the existence of overshoot.When information record carrier adopts different LD 102, FMD _AVG, the relation curve between Pe and the ε three need rebuild.In addition, because the existence of overshoot causes FMD _AVGThe deviation theory value is too many, thereby possibly cause the correction accuracy of Pw to reduce.

For the overshoot differences that reduce to cause because of Different L D 102 inherent attributes difference, a kind of special waveform is proofreaied and correct Pw by special use.This special waveform has reduced the overshoot odds than general waveform.As shown in Figure 9, be the comparison diagram of special waveform with general waveform.Usually, (eight-to-fourteenmodulate, EFM) data, these data also show as an EFM waveform to be about at first to be converted into a kind of eight to 14 modulation by the information of imprinting.Switching point between high level in this EFM waveform (being also referred to as " pit ") and the low spot flat (being also referred to as " land ") characterizes one " 1 ".The record mark that each " pit " sign one records on the information recording carrier.In general waveform, each " pit " in the corresponding EFM waveform has one or more pulses (being Pw), and a pulse only arranged in the special waveform.Be that the time span that the Pw in the special waveform occurs is the length of " pit " in the EFM waveform.Because the number of times that Pw occurs in the special waveform is less than in the general waveform, the also corresponding minimizing of overshoot odds, thus overshoot is to FMD _AVGThe influence of value is also with low.

Only have only two power grades (Pw and Pe) to exist in the special waveform, corresponding FMD signal also has only two kinds of value FMD _PwAnd FMD _PeUsually, in the EFM waveform, the length of all " pit " and with the length of " land " with equate that is the period ratio of " pit " and " land " is 50%.Therefore, Pw also equates FMD with the time span of Pe in the special waveform _PwAnd FMD _PeThe time span that occurs also equates.Thereby, FMD _AVGValue be FMD _PwAnd FMD _PeMean value.Correspondingly, FMD _AVGFMD in the calculating of desired value and the trimming process _AVGThe calculating of value is also greatly simplified.

Please, be the Writing capability correction method process flow diagram of the present invention's one preferred embodiments referring to shown in Figure 10.

At first, step 60 is obtained two different FMD signal values.Drive LD 102 by DSP 12 control LDD 100 and send stable DC power P W_DC1 and the PW_DC2 that had been measured by production smelting tool, the ADC 120 through DSP 12 obtains the FMD signal value (FMD under each power respectively then _DC1With FMD _DC2).

Secondly, step 62 reads the value of one group of Pe and ε from write-in policy table 160.And try to achieve the value of Pw according to the value of Pe and ε.

Then, step 64 is according to FMD _DC1With FMD _DC2Obtain the relation of FMD signal and magnitude of voltage, the FMD signal value (FMD that the Pe that obtains obtaining in the step 62 through interpolation method then is corresponding with Pw _PeWith FMD _Pw).

Follow, step 66 is according to equality FMDTGT=(FMD again _Pe+ FMD _PwFMD is calculated in)/2 _AVGDesired value FMD _TGT

Then, step 68, DSP 12 gives an order and controls the special waveform that LDD 100 drives in LD 102 output maps 9.

Then, step 610,120 pairs of FMD signals of ADC repeatedly sample (preferably above 1,000 times) obtain a plurality of FMD signal values, and these a plurality of FMD signal values asked on average obtain FMD _AVGValue.

Then, step 612 is judged FMD _AVGThe FMD that whether equals to calculate in the step 66 _TGTValue.

If the judged result in the step 612 is FMD _AVGBe not equal to the FMD that calculates in the step 66 _TGTValue is then adjusted the size of Pw through adjusting yield value 145, returns step 68 (step 614) afterwards.

If the judged result in the step 612 is FMD _AVGThe FMD that equals to calculate in the step 66 _TGTValue is then accomplished the adjustment to Pw, and the general waveform in DSP 12 control LDD 100 driving LD 102 output maps 9 is to carry out recording of information.

In the above-mentioned Writing capability correction method, for reducing the FMD signal FMD that ADC 120 is sampled to as much as possible _PeWith FMD _PwThe unequal phenomenon of the probability that occurs, the sequential during the output special waveform is preferably 2 multiples of standard etch-recording speed.In addition, for further reducing overshoot to FMD _AVGThe influence of value can add low-pass filter 18 (shown in figure 11) between ADC 120 and FMD 104.

Claims

1. a Writing capability correction method comprises the steps:

Confirm the desired value of a preposition monitor diode output signal;

Control a laser diode and export a special waveform; This special waveform includes only erase power grade and Writing power grade; Wherein the duration summation of erase power equates with the duration summation of Writing power, and the duration of Writing power and one treats that a corresponding high level lasting time of eight to 14 modulation signals of imprinting equates;

The adjustment Writing power equates with said desired value up to the mean value of sampled value.

2. Writing capability correction method as claimed in claim 1 is characterized in that: also comprise the steps:

Calculating is corresponding to the preposition monitor diode output signal value of a given erase power;

Calculating is corresponding to the preposition monitor diode output signal value of a given Writing power;

Confirm that said desired value is said preposition monitor diode output signal value corresponding to said given erase power and mean value corresponding to the preposition monitor diode output signal value of said given Writing power.

3. Writing capability correction method as claimed in claim 2; It is characterized in that: said given erase power is through information inquiry one a write-in policy table gained to be imprinted CDs, and said given Writing power is that the rate value through erase power that defines among said given erase power and the said write Policy Table and Writing power calculates gained.

4. Writing capability correction method as claimed in claim 1 is characterized in that: said special waveform write 2 multiples that sequential is the standard etch-recording speed.

5. information record carrier; Comprise and be used to send the laser diode of laser to recording medium with recorded information to said recording medium; Be used to drive the laser diode drive that said laser diode sends laser; Be used to control the digital signal processor that said laser diode sends the time span of laser; It is characterized in that: said digital signal processor can send a command to said laser diode drive and drive the output of said laser diode and have the luminous power of a predetermined waveform; Said predetermined waveform includes only Writing power grade and the erase power grade that alternately occurs, and the time span and of the each appearance of Writing power grade is treated the corresponding high level lasting time equal in length in eight to 14 modulation signals of imprinting.

6. information record carrier as claimed in claim 5 is characterized in that: the duration length summation of said erase power grade equates with the duration length summation of said write power grade.

7. information record carrier as claimed in claim 5 is characterized in that: said predetermined waveform is used for the optical power correction process.

8. information record carrier as claimed in claim 5 is characterized in that: said predetermined waveform write 2 multiples that sequential is the standard etch-recording speed.

9. information record carrier as claimed in claim 5; It is characterized in that: comprise that also a write-in policy table is used to write down many group erase power values and the erase power rate value to Writing power, said digital signal processor sends a command to said laser diode according to performance number among the said write Policy Table and rate value.

10. information record carrier as claimed in claim 5; It is characterized in that: also comprise an analogue signal processor, the order that is used to receive said digital signal processor produces drive signal and is sent to said laser diode drive and drives the luminous power that said laser diode is exported specific size.

11. information record carrier as claimed in claim 10; It is characterized in that: comprise that also a preposition monitor diode is used to monitor signal to the said analogue signal processor of monitoring the watt level of said laser diode output and exporting the watt level of the said laser diode output of a reaction, said analogue signal processor is controlled the output power size of said laser diode according to said monitor signal.