CN101794595B

CN101794595B - Optical pick-up testing device and testing method, and optical pick-up automatic regulating apparatus

Info

Publication number: CN101794595B
Application number: CN 201010120076
Authority: CN
Inventors: 柳濑正和; 尾山和也
Original assignee: Sharp Corp
Current assignee: Sharp Corp
Priority date: 2009-01-26
Filing date: 2010-01-25
Publication date: 2012-12-19
Anticipated expiration: 2030-01-25
Also published as: JP2010170635A; CN101794595A; JP4958186B2

Abstract

This invention relates to optical pick-up testing device and testing method, and optical pick-up automatic regulating apparatus, which is object to provide a testing device and testing method capable of using optical pick-up in follow-up control mode of differential push-pull method to perform high precision test. The testing device (11) of the optical pick-up makes the objective lens perform repeated displacement in the radius direction of the optical disc (106), the differential push-pull signal obtained during this time is used to determine whether the configuration of the diffraction grid is good. Specifically, a waveform extracting part (30) of the inspection device (11) extracts the upper and lower envelopes from the time-series data after digital conversion has been performed to the differential push-pull signal. An extreme calculating part (40) calculates a plurality of minimums according to the waveform of the difference of the extracted upper and lower envelopes. A determining part (50) judges when the configuration of the diffraction grid is good, based on whether the calculated deviation of the plurality of minimums are in the scheduled scope or not.

Description

The automatic regulating apparatus of the testing fixture of light picker and inspection method and light picker

Technical field

The testing fixture of the light picker that the present invention relates to use laser to carry out recording of information, playback and the automatic regulating apparatus of inspection method and light picker.

Background technology

Digital versatile disc) etc. in recent years, (DVD:Digital Versatile Disc: optical recording media is used for computing machine and a lot of fields such as audio frequency, video for compact disk (CD:Compact Disc compact disk), digital versatile disc.

For optical recording media is carried out recording of information or playback, need information recording surface with light spot to optical recording media on, and make formed track on the optical tracking optical recording media.Thus, the control that makes the optical tracking track is called tracking Control.

In tracking control, known phase difference method, three-beam method arranged, recommend method, and several kinds of modes such as differential push-pull (DPP:Differential Push-Pull differential push-pull) method.Below, the differential push-pull method is described.

The differential push-pull method is to use the tracking control of three light beams, be in the light path from the laser light source to the CD, diffraction grating to be set, with the transmitted light (0 grade of light) of diffraction grating as main beam, with ± 1 order diffraction light as side beam.Three light beams is exposed to CD, make the luminous point on the CD be spaced apart 1/2 track space of odd.Then, detect each catoptrical push-pull signal of main beam and side beam, with the differential signal of detected signal as tracking error signal.In the differential push-pull method, under the situation that the radial direction of CD is shifted, the side-play amount that produces in each push-pull signal of main beam and side beam is cancelled out each other at beam irradiation position.Consequently, owing to can reduce tracking error signal offset, therefore can carry out stable tracking Control.

But, under the situation that the luminous point of three light beams departs from from 1/2 track space of odd at interval, can't offset above-mentioned skew fully.As its result, the amplitude of tracking error signal possibly reduce, the tracking Control potentially unstable.

As the method for adjustment of the light picker that uses in the differential push-pull method, the known technology that has Japan's open patent 2005-44424 communique (patent documentation 1) for example to be disclosed.In this technology, observe the amplitude variations of the differential push-pull signal under the bigger situation of the beam spacing off-centre big, optical recording media of main beam and side beam.Then, when each that detects CD was changeed the envelope curve of resulting differential push-pull signal, this amplitude had periodically, can adjust light picker, made respectively to obtain at least 2 times maximum value and minimal value respectively.

In addition; Although different, disclosed focus attentions equally in the envelope curve of signal waveform or the signal processing technology of extreme value in the open patent 2007-209782 of Japan communique (patent documentation 2) and the open patent 2004-79079 of the Japan communique (patent documentation 3) with the technical field of above-mentioned known technology.The open patent 2007-209782 of Japan communique (patent documentation 2) has disclosed the relevant technology of signal Processing of the output signal of the pulse oxymeter that relates to the oxygen saturation that is used to determine blood and beats.In addition, Japan's open patent 2004-79079 communique (patent documentation 3) has disclosed based on tracking error signal, has generated the technology that the irradiation position of representing laser is positioned at the offset track signal beyond the track.

The prior art document

[patent documentation]

Patent documentation 1: the open patent 2005-44424 of Japan communique

Patent documentation 2: the open patent 2007-209782 of Japan communique

Patent documentation 3: the open patent 2004-79079 of Japan communique

Summary of the invention

Like this,, need adjust position relation accurately, make the luminous point of three light beams be spaced apart 1/2 track space of integral multiple with respect to the light source of diffraction grating in order to make the tracking Control of using the differential push-pull method stable.

Yet, under the situation of the technology that is disclosed in the open patent 2005-44424 of the Japan communique of stating in the use (patent documentation 1), be difficult to judge accurately whether the configuration of diffraction grating is good.Under the situation of the open patent 2005-44424 of Japan communique (patent documentation 1); When each that detects CD is changeed the envelope curve of resulting differential push-pull signal; This amplitude has periodically; Can adjust light picker, make respectively to obtain at least 2 times maximum value and minimal value respectively.In this case, do not know that the periodicity that should have how many degree in the amplitude of envelope curve could be judged as light picker well.In addition, because whether good the envelope curve waveform that changes resulting differential push-pull signal according to each of CD carry out judgement, therefore also there is the problem that only under the bigger situation of the off-centre of CD, just can carry out high-precision judgement.

Thereby, the objective of the invention is to, testing fixture and the inspection method that can carry out high-precision inspection to the light picker of the tracking control that utilizes the differential push-pull method are provided.Have again, the objective of the invention is to, be provided for making the program of above-mentioned testing fixture execution and writing down recording medium this program, embodied on computer readable.Have again, the objective of the invention is to, provide light picker to carry out high-precision self-adjusting automatic regulating apparatus the tracking control that utilizes the differential push-pull method.

According to summary of the present invention, be a kind of testing fixture of light picker, comprising: error signal generation portion, AD transformation component, storage part, waveform extracting part, extreme value are calculated portion, are reached detection unit.Here, light picker comprises: laser light source, beam splitter, object lens, actuator, and a plurality of photodetectors.Beam splitter carries out shunt to the light that penetrates from laser light source, makes it be divided into a plurality of light beams that comprise main beam and at least two side beams.Object lens all focus on each light beam of a plurality of light beams on the optical recording media.Actuator can make object lens on the direction that the track with optical recording media intersects, carry out anti-reset and move.A plurality of photodetectors detect a plurality of reflected light that each light beams of a plurality of light beams is produced respectively after optical recording media reflects.Error signal generation portion generates differential push-pull signal based on the output of a plurality of photodetectors as tracking error signal.The AD transformation component to object lens carry out on the direction of intersecting with the track of optical recording media that anti-reset moves during in resulting differential push-pull signal carry out digital conversion.Storage part has carried out the very first time sequence data after the digital conversion to the differential push-pull signal and has stored.Waveform extracting part is extracted first waveform based on the very first time sequence data of being stored in the storage part.First waveform of this moment be based on arbitrary side of the envelope curve up and down of very first time sequence data, up and down envelope curve and or the waveform of the difference of envelope curve up and down.The extreme value portion of calculating at a plurality of maximum value or minimum values of first waveform.Detection unit according to the deviation of a plurality of maximum value or minimum values of first waveform that utilizes the extreme value portion of calculating whether in preset range, thereby judge whether beam splitter good with respect to the configuration of laser light source.

According to the testing fixture of above-mentioned light picker, the deviation of the extreme value through estimating first waveform from time series data, extract, thus can carry out the inspection of light picker accurately.Consequently, can suppress the adjustment result's of light picker deviation, can shorten the adjustment time, cut down manpower expense etc.

Preferably waveform extracting part comprises the end points configuration part, reaches envelope curve generation portion.At least one side of left and right sides end points is set to each envelope curve up and down of very first time sequence data in the end points configuration part.Envelope curve generation portion through the side from left and right sides end points begin along time shaft positive dirction or negative direction, from very first time sequence data, extract the data point that satisfies predetermined condition successively, thereby generate each envelope curve up and down.Here, predetermined condition is meant that straight slope through the consecutive number strong point is in preset range.

According to above structure, owing to limit the oscillation amplitude change of envelope curve, make and satisfy predetermined condition, even therefore in very first time sequence data, include the situation of noise component, also can suppress The noise and generate envelope curve.

Preferably envelope curve generation portion is through generating each envelope curve up and down to a plurality of first data points and a plurality of second averaging of data point; Above-mentioned a plurality of first data point is that the positive dirction along time shaft extracts from very first time sequence data, and above-mentioned a plurality of second data points are that the negative direction along time shaft extracts.Thereby, can generate envelope curve more accurately.

Preferably in envelope curve generation portion each data point with very first time sequence data, surpass predetermined threshold and break away from up and down the data point of envelope curve and come from very first time sequence data, to remove as noise, use and removed the very first time sequence data behind the noise and come to generate once more each envelope curve up and down.Thereby, even in very first time sequence data, include under the situation of noise component, also can remove The noise and come to calculate accurately envelope curve.

Preferably the end points configuration part is when setting each left and right sides end points, arranging according to size since at first or during the data point of finally several predetermined number of very first time sequence data, the predetermined several the value of data point is set at the value of end points.

According to said structure and since not with the initial or final data point of very first time sequence data or 0 etc. as end points, so can suppress The noise, and can improve computational accuracy in the end of envelope curve.Consequently, can improve the whether good precision of judgement of detection unit.

Preferably the extreme value portion of calculating comprises sample waveform generation portion, smoothing portion, and minimal point extraction portion, the structure when being used as calculating a plurality of minimal value of first waveform.Sample waveform generation portion is divided into a plurality of intervals with first waveform, generates the sample waveform that each the interval smallest point by a plurality of intervals forms.Smoothing portion generates sample waveform is carried out the smoothing waveform after the moving average.Minimal point extraction portion extracts the value that deducts behind the smoothing waveform from sample waveform to be become between negative a plurality of minus zones, and extracts the minimal point of the smallest point of sample waveform in each interval between a plurality of minus zones as first waveform.

Preferably the extreme value portion of calculating comprises sample waveform generation portion, smoothing portion, and maximal point extraction portion, the structure when being used as calculating a plurality of maximum value of first waveform.Sample waveform generation portion is divided into a plurality of intervals with first waveform, generates the sample waveform that each maximum point by a plurality of intervals forms.Smoothing portion generates sample waveform is carried out the smoothing waveform after the moving average.Maximal point extraction portion extracts the value that deducts behind the smoothing waveform from sample waveform becomes positive a plurality of positive interval, and extracts the maximal point of the maximum point of sample waveform in each interval in a plurality of positive intervals as first waveform.

Calculate the structure of portion according to above-mentioned extreme value; Owing to use the sample waveform of having cut down the first waveform data number to extract maximum value or minimum value; Therefore the noise component that the first original waveform is comprised be can reduce, maximal point or minimal point come to extract accurately.In addition, owing to use the sample waveform after the data number is cut down to extract maximal point or minimal point, therefore can shorten the processing time of computing machine.In addition; Because utilization has been carried out the smoothing waveform after the smoothing through moving average to sample waveform and has been extracted maximal point or minimal point; Even therefore under the significant situation of the oscillation amplitude change of first waveform, also can detect the position of maximal point or minimal point accurately.Consequently, can improve the whether good precision of judgement of detection unit.

Preferably the extreme value portion of calculating comprises sample waveform generation portion, smoothing portion, and minimal point extraction portion, other the desirable structures when being used as calculating a plurality of minimal value of first waveform.Sample waveform generation portion is divided into a plurality of intervals with first waveform, generates the sample waveform that each smallest point by a plurality of intervals forms.Smoothing portion generates sample waveform is carried out the smoothing waveform after the moving average.Minimal point extraction portion extracts the value that deducts behind the smoothing waveform from sample waveform to be become between negative a plurality of minus zones, and on corresponding first waveform of the centre of gravity place of the sample waveform in each interval between extraction and a plurality of minus zone o'clock as the minimal point of first waveform.

Preferably the extreme value portion of calculating comprises sample waveform generation portion, smoothing portion, and maximal point extraction portion, other the desirable structures when being used as calculating a plurality of maximum value of first waveform.Sample waveform generation portion is divided into a plurality of intervals with first waveform, generates the sample waveform that each maximum point by a plurality of intervals forms.Smoothing portion generates sample waveform is carried out the smoothing waveform after the moving average.Maximal point extraction portion extracts the value that deducts behind the smoothing waveform from sample waveform becomes positive a plurality of positive interval, and on corresponding first waveform of the centre of gravity place of the sample waveform in each interval in extraction and a plurality of positive intervals o'clock as the maximal point of first waveform.

Calculate the structure of portion according to above-mentioned extreme value; Because centre of gravity place, the maximal point that extracts first waveform or the minimal point of the sample waveform in utilizing between each positive interval or minus zone; Even therefore in first waveform, comprise under the situation of noise component, also can extract the position of suitable maximal point or minimal point accurately.Consequently, can improve the whether good precision of judgement of detection unit.

Preferably detection unit comprises the extreme value division, reaches comparison portion.The extreme value division will be categorized as first and second group by a plurality of maximum value or minimum values that the extreme value portion of calculating.Comparison portion judges through relatively belonging to the mean value and the mean value that belongs to a plurality of maximum value or minimum values of second group of a plurality of maximum value or minimum values of first group whether beam splitter is good with respect to the configuration of laser light source.

Usually; To make the situation of interior all sides of laser radiation to CD (optical recording media) be categorized as first group through interior all sides that object lens are moved to radially, will make the situation of the outer circumferential side of laser radiation to CD be categorized as second group through the outer circumferential side that makes object lens be moved to CD.At this moment, through first group the mean value of maximum value or minimum value of mean value and second group of maximum value or minimum value relatively, can judge accurately whether light picker is good.

Preferably the extreme value division will utilize the extreme value portion of calculating a plurality of maximum value or minimum values, come alternately to be categorized as first and second group according to the time sequencing of very first time sequence data.Consequently, can be simply the displaced plate of a plurality of maximum value and minimal value and object lens be categorized as first, second group accordingly.

Preferably error signal generation portion comes further to generate to promote mainly to draw signal based on the output of photodetector in a plurality of photodetectors, that the reflected light of main beam is detected.The AD transformation component is drawn signal and is further carried out digital conversion resulting promoting mainly during carrying out displacement repeatedly at object lens.Storage part is also drawn signal and has been carried out second time series data after the digital conversion and store promoting mainly.Waveform extracting part further extracts second waveform based on second time series data of being stored in the storage part.Second waveform of this moment be based on arbitrary side of the envelope curve up and down of second time series data, up and down envelope curve and or the waveform of the difference of envelope curve up and down.A plurality of maximum value or minimum values of second waveform are also calculated by the extreme value portion of calculating.In this case; The extreme value division will utilize in a plurality of maximum value or minimum values of first waveform that the extreme value portion of calculating, be categorized as first group with the roughly the same resulting maximum value or minimum value of the moment of the moment that the maximum value or minimum value that utilizes second waveform that the extreme value portion of calculating is provided, remaining maximum value or minimum value is categorized as second group.

Through utilizing the push-pull signal of main beam as described above, can laser radiation under the situation of interior all sides of CD with laser radiation under the situation of the outer circumferential side of CD, come accurately extreme value to be classified.

Perhaps, preferably error signal generation portion comes further to generate to promote mainly to draw signal based on the output of photodetector in a plurality of photodetectors, that the reflected light of main beam is detected.The AD transformation component is drawn signal and is further carried out digital conversion resulting promoting mainly during carrying out displacement repeatedly at object lens.Storage part is also drawn signal and has been carried out second time series data after the digital conversion and store promoting mainly.Waveform extracting part further extracts second waveform based on second time series data of being stored in the storage part.Second waveform of this moment be based on arbitrary side of the envelope curve up and down of second time series data, up and down envelope curve and or the waveform of the difference of envelope curve up and down.The a plurality of maximum value and the minimal value of second waveform also calculated by the extreme value portion of calculating.In this case; The extreme value division will utilize in a plurality of maximum value or minimum values of first waveform that the extreme value portion of calculating, with provide the roughly the same resulting maximum value or minimum value of the moment of the minimizing moment of second waveform to be categorized as first group, will be categorized as second group with roughly the same resulting maximum value or minimum value of the moment of the moment of the maximum value that second waveform is provided.

Through utilizing the push-pull signal of main beam as described above, can laser radiation under the situation of interior all sides of CD with laser radiation under the situation of the outer circumferential side of CD, come further accurately extreme value to be classified.

Among the present invention in other respects, be the inspection method that is used to check the light picker of light picker, above-mentioned light picker comprises: laser light source, beam splitter, object lens, actuator, and a plurality of photodetectors.Here, beam splitter carries out shunt to the light that penetrates from laser light source, makes it be divided into a plurality of light beams that comprise main beam and at least two side beams.Object lens all focus on each light beam of a plurality of light beams on the optical recording media.The enterprising line displacement of direction that actuator can make object lens intersect at the track with optical recording media times without number.A plurality of photodetectors detect a plurality of reflected light that each light beams of a plurality of light beams is produced respectively after optical recording media reflects.At this moment, the inspection method of light picker comprises: generate based on the differential push-pull signal of the output of a plurality of photodetectors step as tracking error signal; To object lens carry out on the direction of intersecting with the track of optical recording media that anti-reset moves during in the resulting differential push-pull signal step of carrying out digital conversion; The differential push-pull signal has been carried out the step that the very first time sequence data after the digital conversion is stored; And the very first time sequence data of being stored in the step based on storage extracts the step of first waveform.At this moment, first waveform be based on arbitrary side of the envelope curve up and down of very first time sequence data, up and down envelope curve and or the waveform of the difference of envelope curve up and down.The inspection method of light picker also comprises: the step of calculating a plurality of maximum value or minimum values of first waveform; And the deviation of a plurality of maximum value or minimum values of first waveform of calculating according to the step of calculating whether in predetermined scope, judge the step that whether good beam splitter with respect to the configuration of laser light source.

The present invention also in other respects in, be the automatic regulating apparatus of light picker, comprising: error signal generation portion, AD transformation component, storage part, waveform extracting part, extreme value are calculated portion, detection unit, and adjustment part.Here, light picker comprises: laser light source, beam splitter, object lens, actuator, and a plurality of photodetectors.Beam splitter carries out shunt to the light that penetrates from laser light source, makes it be divided into a plurality of light beams that comprise main beam and at least two side beams.Object lens all focus on each light beam of a plurality of light beams on the optical recording media.The enterprising line displacement of direction that actuator can make object lens intersect at the track with optical recording media times without number.A plurality of photodetectors detect a plurality of reflected light that each light beams of a plurality of light beams is produced respectively after optical recording media reflects.Error signal generation portion generates differential push-pull signal based on the output of a plurality of photodetectors as tracking error signal.The AD transformation component to object lens carry out on the direction of intersecting with the track of optical recording media that anti-reset moves during in resulting differential push-pull signal carry out digital conversion.Storage part has carried out the very first time sequence data after the digital conversion to the differential push-pull signal and has stored.Waveform extracting part is extracted first waveform based on the very first time sequence data of being stored in the storage part.First waveform of this moment be based on arbitrary side of the envelope curve up and down of very first time sequence data, up and down envelope curve and or the waveform of the difference of envelope curve up and down.The extreme value portion of calculating at a plurality of maximum value or minimum values of first waveform.Detection unit according to the deviation of a plurality of maximum value or minimum values of first waveform that utilizes the extreme value portion of calculating whether in predetermined scope, thereby judge whether beam splitter good with respect to the configuration of laser light source.The configuration of beam splitter with respect to laser light source adjusted according to the result of determination of detection unit in the adjustment part.

As stated, if according to the present invention, can improve the inspection precision of the light picker of the tracking control that utilizes the differential push-pull method.

Description of drawings

Fig. 1 is the figure of concise and to the point formation of testing fixture 11 of the light picker 101 of expression embodiment 1 of the present invention.

Fig. 2 is the figure that expression focuses on the irradiation position of the three light beams on the optical recording media 106.

Fig. 3 is the figure of the formation of expression optical detection part 110 and error signal generation portion 221.

Fig. 4 is the synoptic diagram of an example of the signal waveform of expression differential push-pull signals DP P.

Fig. 5 is the block scheme that the hardware of computing machine 201 of the testing fixture 11 of presentation graphs 1 constitutes.

Fig. 6 is the block scheme that the software of computing machine 201 of the testing fixture 11 of expression pie graph 1 constitutes.

Fig. 7 is the process flow diagram of checks sequence of the testing fixture 11 of expression light picker.

Fig. 8 is the figure of expression from an example of the time series data 320 of AD transformation component 202 outputs.

Fig. 9 is the process flow diagram of the order of the step ST504 of presentation graphs 7 in more detail.

Figure 10 is the figure of processing sequence that is used for the step S603 of key diagram 9.

Figure 11 is the figure of processing sequence that is used for the step S604 of key diagram 9.

Figure 12 is the process flow diagram of order of step S603 and the S604 of presentation graphs 9.

Figure 13 is the figure of processing sequence that is used for the step S605 of key diagram 9.

Figure 14 is the figure of processing sequence that is used for the step S607 of key diagram 9.

Figure 15 is the figure of the envelope curve up and down 321,322 that generates based on time series data shown in Figure 8 320 of expression.

The figure of Figure 16 low frequency waveform 323 that to be expression generate according to the envelope curve up and down 321,322 of Figure 15.

Figure 17 is the process flow diagram of the order of the step ST506 of presentation graphs 7 in more detail.

Figure 18 is the figure of processing sequence that is used to explain the step S551 of Figure 17.

Figure 19 is the figure of the sample waveform 324 that generates among the step S551 of expression Figure 17.

Figure 20 is the figure of processing sequence that is used to explain the step S553 of Figure 17.

Figure 21 is the figure that is illustrated in the position of the minimal point V1 to V5 of decision on the low frequency waveform 323.

Figure 22 is the process flow diagram of the order of the step ST507 of presentation graphs 7 in more detail.

Figure 23 is the figure of an example of expression differential push-pull signal.

Figure 24 is the figure of an example that expression comprises the signal of maximal point and minimal point.

Figure 25 is the figure of the sample waveform 326 that generates among the step S551 of expression Figure 17.

Figure 26 is the figure of processing sequence that is used to explain the step S553 of Figure 17.

Figure 27 is the figure that time series data 328 of drawing signal MPP and the envelope curve 329,330 up and down that is generated are promoted mainly in expression.

The figure of Figure 28 low frequency waveform 331 that to be expression generate according to the envelope curve up and down 329,330 of Figure 27.

Figure 29 is the figure of sorting technique of a plurality of minimal points that is used for explaining the low frequency waveform 323 of embodiment 2.

Figure 30 is the figure of sorting technique of a plurality of minimal points that is used for explaining the low frequency waveform 323 of embodiment 3.

Figure 31 is the figure of processing sequence that is used to explain the step S553 of Figure 17.

Figure 32 is the block scheme of concise and to the point formation of the automatic regulating apparatus 12 of the light picker of expression in the embodiment 5 of the present invention.

Figure 33 is the block scheme that the software of the computing machine 201A of the expression automatic regulating apparatus 12 that constitutes Figure 32 constitutes.

Figure 34 is the adjustment process flow diagram in proper order of the automatic regulating apparatus 12 of expression light picker.

Label declaration

The testing fixture of 11 light pickers

The automatic regulating apparatus of 12 light pickers

21 direct motor drive portions

22 object lens drive divisions

23 storage parts

24 diffraction grating adjustment parts

30 waveform extracting part

31 end points configuration parts

32 envelope curve generation portions

33 waveform operational parts

40 extreme values are calculated portion

41 sample waveform generation portions

42 smoothing portions

43 minimal points (maximal point) extraction portion

50 detection units

51 extreme value divisions

52 comparison portions

101,101A light picker

102 laser light sources (semiconductor laser)

104 diffraction grating

106 smooth programmed recording mediums

107 object lens

111 actuators

112 spindle drive motors

121 main beams

122,123 side beams

131 4 cut apart photodetector

132,133 2 cut apart photodetector

201,201A computing machine

The 202AD transformation component

221 error signal generation portions

320,328 time series datas

321, envelope curve on 329

322,330 times envelope curves

323,331 low frequency waveforms

324,326 sample waveforms

325, DPP differential push-pull signal MPP promotes mainly and draws signal SPP, SPP1, the secondary push-pull signal of SPP2 between positive interval [Si, the Ti] minus zone of 327 smoothing waveforms [Pi, Qi]

Embodiment

Below, the embodiment that present invention will be described in detail with reference to the accompanying.In addition, identical or considerable part have been added identical, do not repeated it is described with reference to label.

[embodiment 1]

(the concise and to the point formation of light picker and testing fixture thereof)

Fig. 1 is the figure of concise and to the point formation of the testing fixture 11 of the light picker 101 of expression in the embodiment 1 of the present invention.

With reference to Fig. 1, light picker 101 through with laser radiation to the optical recording media that utilizes spindle drive motor 112 to be rotated (CD) 106, thereby read institute's information recorded in the optical recording media 106.

The light picker 101 of Fig. 1 comprises: as the semiconductor laser 102 of laser light source, collimation lens 103, as beam splitter diffraction grating 104, spectroscope 105, with the object lens 107 of laser focusing to the optical recording media 106, drive the actuator 111 of object lens 107, reflected light condenser lens 108, the cylindrical lens 109 that the light by optical recording media 106 reflections is focused on and optical detection part 110 with a plurality of photodetectors 131,132,133.

Collimation lens 103 will be a directional light from the optical beam transformation that semiconductor laser 102 penetrates.

Diffraction grating 104 will be divided into the three light beams that comprises a branch of main beam (0 grade of light) and two bundle side beams (± 1 order diffraction light) from the directional light of collimation lens 103 outputs.Spectroscope 105 is crossed in the transmittance of each light beam, utilizes object lens 107 and focuses on the optical recording media 106.

Actuator 111 utilizes drive coil to make object lens 107 displacements.When institute's information recorded is read in to optical recording media 106, actuator 111 is driven, make the distance of optical recording media 106 and object lens 107 keep certain (focus servo control).Have again, when sense information, actuator 111 is driven, make the information track (tracking servo control) of irradiation position tracking illumination recording medium 106 of light beam.

Fig. 2 is the figure that expression focuses on the irradiation position of the three light beams on the optical recording media 106.With reference to Fig. 2, utilize tracking servo control, the irradiation position of main beam 121 is controlled, make main beam 121 shine the center of information track 126.At this moment, side beam 122,123 being departed from 1/2 track respectively to the left and right with respect to main beam 121 shines.That is, with side beam 122 shine track 126 and with the central authorities of its left side tracks adjacent 125, with side beam 123 shine track 126 and with the central authorities of its right side tracks adjacent 127.

Refer again to Fig. 1, three light beams 121,122,123 is reflected respectively by optical recording media 106.Consequent three beams reflected light guides to test section 110 through reflected light condenser lens 108 and cylindrical lens 109 through spectroscope 105 and light path is turned.The error signal generation portion 221 that states after being utilized among Fig. 3 generates tracking error signal from the reflected light that guides to optical detection part 110.In addition, cylindrical lens 109 is designed for utilizes method of astigmatism to carry out focus servo.

With reference to Fig. 3, optical detection part 110 comprises: main beam use four cut apart photodetector 131, and two bundle side beams use two cut apart photodetector 132,133.Four cut apart photodetector 131 sensitive surface be divided into four photo detectors (A, B, C, D).In addition; Two cut apart photodetector 132 sensitive surface be divided into two photo detectors (E, F); 2 cut apart photodetector 133 sensitive surface be divided into these photo detectors (A to H) of two photo detectors (G, H) and independently light detected respectively, and output and the corresponding signal of detected light intensity.In addition, in Fig. 3, be shown in broken lines the light beam that exposes to each photodetector 131 to 133.In addition, because method of astigmatism is used in focus control, so the orbital direction on the CD and the orbital direction on the photo detector are to have departed from 90 directions spent.Thereby, also show orbital direction on the photo detector among Fig. 3 the situation after 90 degree depart from has taken place.

The error signal generation portion 221 of Fig. 3 generates push-pull signal MPP, SPP1, and the SPP2 of each photodetector 131 to 133, and based on these push-pull signals MPP, SPP1, and SPP2 generate differential push-pull signals DP P.The testing fixture 11 of light picker is used as tracking error signal with differential push-pull signals DP P.

Error signal generation portion 221 comprises: subtraction device 141,142,143,146, adder calculator 144 and constant multiplicative operator 145.Under the situation of embodiment 1, mimic channels such as these arithmetical unit 141 to 146 use operational amplifiers constitute.

Subtraction device 141 is drawn signal MPP with the difference signal output of photo detector A, D and photo detector B, C as promoting mainly.Subtraction device 142 exports the difference signal of photo detector E and photo detector F as secondary push-pull signal SPP1.Subtraction device 143 exports the difference signal of photo detector G and photo detector H as secondary push-pull signal SPP2.Adder calculator 144 is exported as secondary push-pull signal SPP with signal secondary push-pull signal SPP1 and SPP2's.Subtraction device 146 will be promoted mainly and draw the difference signal that signal MPP multiply by the secondary push-pull signal SPP of k times of constant with utilizing constant multiplicative operator 145 and export as differential push-pull signals DP P.When the intensity of the light signal that photo detector A to H is accepted was made as a to h respectively, above-mentioned relation can be expressed as following formula.

DPP＝MPP-k×SPP (1)

MPP＝(a+d)-(b+c) (2)

SPP＝SPP1+SPP2，SPP1＝e-f，SPP2＝g-h (3)

In the formula, coefficient k is used to revise light intensity different of light intensity and+1 grade of light and-1 grade of light of 0 grade of light.For example, be 0 grade of light in beam intensity ratio :+1 grade of light: under the situation of-1 grade of light=I0: I1: I1, coefficient k=I0/ (2 * I1).

With reference to Fig. 1, testing fixture 11 comprises above-mentioned error signal generation portion 221, computing machine 201, reaches the display equipment 207 that shows check result once more.

Computing machine 201 utilizes from the differential push-pull signals DP P of error signal generation portion 221 outputs, judges whether diffraction grating 104 is suitable with respect to the position and the posture of semiconductor laser 102.Therefore, computing machine 210 at first utilizes spindle drive motor 112 to make optical recording media 106 rotations, and control light picker 101, and making becomes the state that does not carry out tracking servo and only carry out focus servo.After this, computing machine 201 utilize actuator 111 make object lens 107 repeatedly displacement in the interior all sides and the outer circumferential side of the radial direction (crossing orbital direction) of optical recording media 106.Thus, the irradiation position of the light beam on the optical recording media 106 is also repeatedly between interior all sides and outer circumferential side of radial direction.Computing machine 201 through to this moment resulting differential push-pull signals DP P time series data resolve, thereby judge whether diffraction grating 104 suitable with respect to the configuration of semiconductor laser 102.Below, come the briefing of utilizing the signal Processing that computing machine 201 carries out is described with reference to concrete waveform.

Fig. 4 is the synoptic diagram of an example of the signal waveform of expression differential push-pull signals DP P.Fig. 4 (A), (B) are examples of the waveform under the suitable situation of the configuration of diffraction grating 104, and Fig. 4 (C) is an example of the waveform under the unsuitable situation of configuration of diffraction grating 104.The X axle express time axle of Fig. 4 (A) to (C), the Y axle is represented the signal intensity of differential push-pull signals DP P.

At first, with reference to Fig. 4 (A), be spaced apart at the luminous point of three light beams under the situation of 1/2 track space of odd, differential push-pull signals DP P becomes the signal after the skew that produces among each push-pull signal MPP, the SPP is cancelled out each other.Consequently; Only carry out under the state of focus servo not carrying out tracking servo; Alternately be displaced at object lens 107 under the situation of outer circumferential side and interior all sides of radial direction of optical recording media 106 Fig. 1; That kind shown in Fig. 4 (A) can be shown the waveform of the differential push-pull signals DP P that same amplitude periodically changes greatly.The periodic variation of seen differential push-pull signals DP P among Fig. 4 (A) is that the signal when passing across the track of optical recording media 106 by luminous point changes caused.

But,, also almost can't obtain the signal waveform of the same amplitude as Fig. 4 (A) even the configuration of diffraction grating 104 is suitable.For example, the track space of DVD-R is 0.74 μ m, but the track space of DVD-RAM (Type II) is 0.615 μ m.Therefore, even under the situation of DVD-R as Fig. 4 (A) the skew that produces among each push-pull signal MPP, the SPP is ideally offset light picker, but under the situation of DVD-RAM (Type II), can not fully offset above-mentioned skew.

Consequently, that kind shown in Fig. 4 (B) in the waveform of differential push-pull signals DP P, except comprising the waveform that is passed across the caused frequency component of track by luminous point, also comprises the more waveform of low frequency component.That is, that kind shown in Fig. 4 (B) changes in the amplitude of differential push-pull signal DPP, bigger peak portion of amplitude 81 and the bigger paddy portion 82 of amplitude periodically occur.

Aforesaid oscillation amplitude change is corresponding to the displaced plate of the radial direction of optical recording media 106 with object lens 107.Usually, peak portion 81 is situation of central portion of the radial direction that is centered close to optical recording media 106 of object lens 107, and paddy portion 82 is all sides of object lens 107 radial direction that is positioned at optical recording media 106 or the situation of outer circumferential side.It the reasons are as follows.

Usually light picker is adjusted, made that light beam is through the center of object lens 107 when the central portion of the radial direction that is centered close to optical recording media 106 of object lens 107.Thereby under the situation of interior all sides that object lens 107 are offset to optical recording media 106 or outer circumferential side, depart from from the center of object lens 107 at the center of light beam.Therefore, becoming more remarkable in the deviation of the intensity of the three light beams of interior all sides of optical recording media 106 and outer circumferential side, as a result of is that the intensity of differential push-pull signals DP P weakens.

With respect to these signal waveforms, under the very messy at interval situation of the mutual point of, three light beams inappropriate with respect to the configuration of laser light source at diffraction grating 104, that kind shown in Fig. 4 (C) also generates deviation in the amplitude of differential push-pull signals DP P.That is, under the situation of Fig. 4 (B), the amplitude of paddy portion 82 is roughly certain, and to this under the situation of Fig. 4 (C), then each other the different 82A of paddy portion, the 82B of amplitude alternately occurs.A paddy portion among the 82A of paddy portion of Fig. 4 (C), the 82B is corresponding with the situation of the interior all sides that are centered close to optical recording media 106 of object lens 107, and another paddy portion is corresponding with the situation that is centered close to outer circumferential side of object lens 107.In addition, compare the bigger peak portion 81 of amplitude with the 82A of paddy portion, 82B, corresponding with the situation of the central portion of the radial direction that is centered close to optical recording media 106 of object lens 107.

Thus, whether good according to the configuration of the diffraction grating 104 of Fig. 1, in the waveform of differential push-pull signals DP P, different with the waveform of the corresponding low frequency component of displacement of object lens 107.Therefore, the testing fixture 11 of the light picker of Fig. 1 utilizes the waveform of this low frequency component different, judges whether the configuration of diffraction grating 104 is good.Below, the waveform of the frequency component that will change corresponding to the displacement of object lens 107 is called the low frequency waveform.

Particularly, the computing machine 201 of testing fixture 11 generates the envelope curve up and down of the time series data of differential push-pull signals DP P.Then, computing machine 201 is obtained this waveform of the difference of envelope curve up and down, as above-mentioned low frequency waveform, calculates a plurality of minimal values of the waveform of being obtained.Then, computing machine 201 judges that the configuration of diffraction grating 104 is suitable under the situation of a plurality of minimizing deviation less than predetermined threshold of calculating.Below, the formation and the action of the testing fixture 11 of light picker is elaborated.

(hardware of the testing fixture of light picker constitutes)

Fig. 5 is the block scheme that the hardware of computing machine 201 of the testing fixture 11 of presentation graphs 1 constitutes.With reference to Fig. 5, computing machine 201 comprises: AD (Analog to Digital: analog to digital) transformation component 202, memory storage 203, operational part 204, efferent 205, input part 206, and

communication interface

208A, 208B.

The simulating signal that AD transformation component 202 will be generated by error signal generation portion 221, be that differential push-pull signals DP P is transformed to the seasonal effect in time series numerical data.

Deposit data that the outside by computing machine 201 provides, and the data that in computing machine 201, generate in the memory storage 203.The data that provided by the outside are for example by setting value of the action of the seasonal effect in time series numerical data of above-mentioned AD transformation component 202 conversion or regulation computing machine 201 etc.The data that in computing machine 201, generate for example are useful on the data of utilizing the signal Processing that operational part 204 calculates or judge the result that light picker 101 is whether good.

Memory storage 203 comprises: the external memory of storage such as hard disk large-capacity data or the semiconductor memory of non-volatile and volatibility etc.

Operational part 204 is according to the program that generates in advance, carries out the microprocessor of the processing of leaving the data in the memory storage 203 in.Operational part 204 outputs to efferent 205 with data processed result.In addition, operational part 204 is controlled the actuator 111 and the spindle drive motor 112 of light picker 101 through

communication interface

208A, 208B.

Efferent 205 outputs to display device 207 with the data processed result of operational part 204.Display device 207 is with video data result on picture such as character or figure.

Input part 206 is accepted the input of data or order from the outside of computing machine 201.

(the concise and to the point formation of the software of the testing fixture of light picker)

Fig. 6 is the block scheme that the software of computing machine 201 of the testing fixture 11 of expression pie graph 1 constitutes.If see its function, computing machine 201 comprises: object lens drive division 22, storage part 23, waveform extracting part 30, the extreme value of the actuator 111 of the direct motor drive portion 21 of the rotation of control spindle drive motor 112, control light picker 101 calculated portion 40, reached detection unit 50.

Storage part 23 store utilize actuator 111 make object lens 107 in during carry out on the radial direction of optical recording media 106 that anti-reset moves, the differential push-pull signals DP P that carried out digital conversion, as time series data.

Waveform extracting part 30 extracts the low frequency waveform that changes corresponding to the periodicity displacement of object lens based on the time series data of the differential push-pull signals DP P that is stored in storage part 23.Particularly, the waveform of the difference of the envelope curve up and down of 30 rise time of waveform extracting part sequence data is used as the low frequency waveform.Waveform extracting part 30 comprises end points configuration part 31, envelope curve generation portion 32, reaches waveform operational part 33.31 pairs of end points configuration parts each up and down envelope curve set envelope curve about end points.Envelope curve generation portion 32 through begin from left end point along time shaft positive dirction, from time series data, extract the data point that satisfies predetermined envelope curve condition successively, thereby generate each envelope curve up and down.Have again, envelope curve generation portion 32 through begin from right endpoint along time shaft negative direction, from time series data, extract the data point that satisfies predetermined envelope curve condition successively, thereby generate each envelope curve up and down.Final envelope curve is through will and after the averaging of envelope curve of time shaft negative direction generation, obtaining along the envelope curve of time shaft positive dirction generation.Here, so-called envelope curve condition is meant that straight slope through the consecutive number strong point is in preset range.The waveform output of the difference of the envelope curve up and down that waveform operational part 33 will generate in envelope curve generation portion 32 is as the low frequency waveform.

Extreme value is calculated a plurality of minimal values that the low frequency waveform that extracts in waveform extracting part 30 is calculated by portion 40.Extreme value is calculated portion 40 and is comprised sample waveform generation portion 41, smoothing portion 42, reaches minimal point extraction portion 43.Sample waveform generation portion 41 is divided into a plurality of intervals with the low frequency waveform, generates the sample waveform that each the interval smallest point by a plurality of intervals forms.Smoothing portion 42 generates sample waveform is carried out the smoothing waveform after the moving average.Minimal point extraction portion 43 extracts the value that deducts behind the smoothing waveform from sample waveform to be become between negative a plurality of minus zones, and the smallest point of the sample waveform in extracting between each minus zone between a plurality of minus zones is as the minimal point of low frequency waveform.

Detection unit 50 whether in preset range, judges whether diffraction grating 104 is good with respect to the configuration (position and posture) of semiconductor laser 102 according to a plurality of minimizing deviation of being calculated the low frequency waveform that portion 40 calculates by extreme value.Detection unit 50 comprises extreme value division 51 and comparison portion 52.Extreme value division 51 will be calculated a plurality of minimal values that portion 40 calculates by extreme value and will be categorized as first and second group.Comparison portion 52 judges through relatively belonging to first group a plurality of minimizing mean value and belonging to second group a plurality of minimizing mean value whether diffraction grating 104 is good with respect to the configuration of laser light source 102.

(action of the testing fixture of light picker)

Then, the action to the testing fixture 11 of light picker with above-mentioned formation describes.

With reference to Fig. 5 to Fig. 7, in the step S501 of Fig. 7, computing machine 201 carries out the initial setting of testing fixture 11.Particularly; The input of the parameter below the input part 206 of computing machine 201 is accepted: promptly, sampling rate Srate, sampled data are counted Snum, interval censored data and are counted noise remove grade Nrej, end points that moving average data that DSnum, moving average data count DAvnum, good decision threshold Th, the first top limits value UL1, the first below limits value LL1, the second top limits value UL2, the second below limits value LL2, envelope curve count EAvnum, envelope curve and calculate data and count IDnum, and the end points specified order Norder etc. that calculates usefulness.The meaning of each parameter will describe in the treatment step that uses each parameter.Each parameter of being imported is deposited in the memory storage 203 of computing machine of Fig. 5.

In embodiment 1, the value of each parameter is carried out concrete setting as follows.That is, sampling rate Srate=1200Hz, sampled data are counted Snum=1800, interval censored data and are counted noise remove grade Nrej=1.2, end points that moving average data that Dsnum=50, moving average data count DAvnum=11, good decision threshold Th=0.05, the first top limits value UL1=0.1, the first below limits value LL1=-0.1, the second top limits value UL2=0.06, the second below limits value LL2=-0.06, envelope curve count EAvnum=60, envelope curve and calculate data and count IDnum=20, and the end points specified order Norder=8 that calculates usefulness.

In next procedure S502, the object lens drive division of computing machine 201 22 is through the actuator 111 of control chart 1, thus make object lens 107 repeatedly displacement between interior all sides and outer circumferential side of the radial direction (passing across the direction of track) of optical recording media 106.The differential push-pull signals DP P that computing machine 201 obtains this moment utilizes AD transformation component 202 to carry out digital conversion, and obtains as time series data.At this moment, the above-mentioned sampling rate Srate of AD transformation component 202 usefulness samples to differential push-pull signals DP P.Thus, generate the time series data that sampled data is counted Snum.Here, sampling rate Srate is set at reproduces the frequency that original signal is the variation of differential push-pull signals DP P fully.

In next procedure S503, computing machine 201 will utilize AD transformation component 201 to carry out the time series data after the digital conversion and be stored in the memory storage 203.

In next procedure S504, the envelope curve up and down of 30 rise time of the waveform extracting part sequence data of computing machine 201.In next procedure S505, the difference of envelope curve was the low frequency waveform about waveform extracting part 30 generated.The detailed sequence of step S504, S505 will be narrated with reference to Fig. 8 to Figure 16 in the back.

In next procedure S506, the extreme value of computing machine 201 is calculated a plurality of minimal values that the low frequency waveform is calculated by portion 40.The detailed sequence of step S506 will be narrated with reference to Figure 17 to Figure 21 in the back.

In next procedure S507; The a plurality of minimizing deviation of the low frequency waveform that the detection unit 50 of computing machine 201 is calculated according to step S506 whether in preset range, thereby judge whether diffraction grating 104 good with respect to the position and the posture of semiconductor laser 102.The detailed sequence of step S506 will be narrated with reference to Figure 22 in the back.Thus, the be through with checks sequence of testing fixture 11 of light picker.

(the step S504 of generation-Fig. 7 of envelope curve)

Fig. 8 is the figure of expression from an example of the time series data 320 of AD transformation component 202 outputs.In Fig. 8, X axle express time axle, the Y axle is represented the signal intensity of differential push-pull signals DP P.In the time series data 320 of reality, except existence comprises the signal that the amplitude cycle property of a plurality of peak portions 81 and the 82A of paddy portion, 82B changes, also there is local outstanding noise signal 83.Therefore, the method for explanation below the waveform extracting part 30 of Fig. 6 is utilized generates the envelope curve of time series data 320, makes it not receive the influence of these noise signals 83.

Fig. 9 is the process flow diagram of the order of the step ST504 of presentation graphs 7 in more detail.Below, suitably with reference to process flow diagram and Figure 10 to Figure 15 of Fig. 9, open-birth becomes the order of the envelope curve (going up envelope curve) of the upside of time series data 320.

In the step S601 of Fig. 9, the waveform extracting part 30 of the computing machine 201 of Fig. 6 is carried out initial setting.In order to calculate the needed setting value of envelope curve is following eight: promptly, noise remove grade Nrej, the end points that the moving average data of the first top limits value UL1, the first below limits value LL1, the second top limits value UL2, the second below limits value LL2, envelope curve are counted EAvnum, envelope curve calculated data and counted IDnum, and the end points specified order Norder that calculates usefulness.In embodiment 1, be set respectively and be the value shown in following.Noise remove grade Nrej=1.2, the end points that the moving average data of the first top limits value UL1=0.1, the first below limits value LL1=-0.1, the second top limits value UL2=0.06, the second below limits value LL2=-0.06, envelope curve are counted EAvnum=60, envelope curve calculated data and counted IDnum=20, and the end points specified order Norder=8 that calculates usefulness.These values all are the values of in the step S501 of Fig. 7, importing.

In next procedure S602, the left and right sides end points of going up envelope curve is set in the end points configuration part 31 of the waveform extracting part 30 of Fig. 6.End points is the starting point that from the time series data of Snum sampled data number, extracts the processing of envelope curve.In following explanation, the coordinate of establishing left end point for (Xinit, Yinit).

Particularly; End points configuration part 31 is in Snum sampled data; Calculate data and count IDnum promptly in 20 data going out end points since time data point number the earliest, with specified order Norder promptly the 8th bigger value be set at the initial value Yinit that is used for extracting envelope curve on the positive dirction of time shaft.Because end points is calculated data and is counted maximal value in the sampled data of IDnum to receive the possibility of noise effect maximum, therefore hopes that it is more than 2 that end points is calculated the specified order Norder of use.In embodiment 1, count in 20 sampled datas of IDnum calculating data as end points, be 7 points even receive counting of noise effect, be 8 but set specified order Norder, also can suppress The noise.

Also identical to right endpoint; In Snum sampled data; Go out end points since nearest data point number of time and calculate data and count in the data of IDnum, specified order Norder bigger value is set at the initial value that is used for upwards extracting envelope curve above the time shaft.

Then, in the step S603 of Fig. 9, the envelope curve generation portion 32 of Fig. 6 along the positive dirction of time shaft, extracts the data point of the candidate that becomes the last envelope curve that satisfies the envelope curve condition from left end point (Xinit, Yinit) beginning successively from time series data 320.

Figure 10 is the figure of processing sequence that is used for the step S603 of key diagram 9.In Figure 10, schematically show the 14 initial data points A to N of time series data 320.In Figure 10, the left side is time data early, and the right side is near data of time.Point 301 among the figure be the end points that utilizes the envelope curve that the end points configuration part 31 of Fig. 6 sets (Xinit, Yinit).

Under the situation of Figure 10, envelope curve generation portion 32 from end points (Xinit Yinit) begins to set out, the point of reference time axle positive dirction successively, promptly put B, some C, some D, some E ..., make the point that satisfies predetermined envelope curve condition become the next candidate point of going up envelope curve.Here, so-called envelope curve condition, the straight slope that be meant in the data point of last envelope curve, passes through the consecutive number strong point is in preset range.That is be that (Xinit, under situation Yinit), (Xn Yn) can use the first below limits value LL1 and the first top limits value UL1 and provides with following formula (4) end points to satisfy the next candidate point of envelope curve condition, at current candidate point.

LL1×(Xn-Xinit)≤Yn-Yinit≤UL1×(Xn-Xinit) (4)

The first top limits value UL1 of following formula and the first below limits value LL1 be the upper limit and the lower limit of the variable quantity (slope) of the data of axial each data unit of express time respectively.In Figure 10, show the top limited field 302 and below limited field 303 that satisfy above-mentioned envelope curve condition.

Particularly, establish Yinit=3.0, and some B (X coordinate: XB, the Y coordinate: it is 1.0 that Y YB) sits target value YB, (X coordinate: XC, the Y coordinate: it is 3.1 that Y YC) sits target value YC to some C.Under the situation of a B, as follows:

LL1×(XB-Xinit)＝-0.1×1＝-0.1

YB-Yinit＝1.0-3.0＝-2.0

UL1×(XB-Xinit)＝0.1×1＝0.1

Do not satisfy following formula (4).Thus, under the situation of the next candidate point of envelope curve, envelope curve generation portion 32 can not be lower than the candidate point of the point of the first below limits value LL1 as envelope curve with the candidate point of current last envelope curve and the slope of next candidate point on extracting.

On the other hand, under the situation of a C, as follows:

LL1×(XC-Xinit)＝-0.1×2＝-0.2

YB-Yinit＝3.1-3.0＝0.1

UL1×(XC-Xinit)＝0.1×2＝0.2

Satisfy following formula (4).Therefore, some C becomes the candidate point of envelope curve.

Then, C promptly puts as benchmark with current last envelope curve candidate point in envelope curve generation portion 32, at the candidate point of exploring envelope curve on the next one on the positive dirction of time shaft.At this moment, because some D, E, F is lower than with a C is the below limited field 303C of benchmark, does not therefore become the candidate point of going up envelope curve.Since some G satisfy with a C be benchmark above limited field 302C and below envelope curve condition in the scope of limited field 303C, therefore become the next candidate point of going up envelope curve.

Then, G promptly puts as benchmark with current last envelope curve candidate point in envelope curve generation portion 32, at the candidate point of exploring envelope curve on the next one on the positive dirction of time shaft.At this moment, be the below limited field 303G of benchmark because some H is lower than with a G, therefore do not become the candidate point of going up envelope curve.On the other hand, to be higher than with a G be the top limited field 302G of benchmark to some I.Here, envelope curve generation portion 32 is under the situation that is higher than the scope (between below limited field 303G and the top limited field 302G) that satisfies the envelope curve condition, with the some Ia of the upper limit of the scope that satisfies the envelope curve condition candidate point as last envelope curve.

Then, Ia promptly puts as benchmark with current last envelope curve candidate point in envelope curve generation portion 32, at the candidate point of exploring envelope curve on the next one on the positive dirction of time shaft.At this moment, be the below limited field 303Ia of benchmark because some J is lower than with an Ia, therefore do not become the candidate point of going up envelope curve.On the other hand, owing to some K with an Ia be benchmark below limited field 303Ia and above satisfy the envelope curve condition between the limited field 302Ia, therefore become the next candidate that goes up envelope curve.

Then, K promptly puts as benchmark with current last envelope curve candidate point in envelope curve generation portion 32, at the candidate point of exploring envelope curve on the next one on the positive dirction of time shaft.At this moment, because some L, M is lower than with a K is the below limited field 303K of benchmark, does not therefore become the candidate point of going up envelope curve.On the other hand, owing to some N below with a K benchmark limited field 303K and above satisfy the envelope curve condition between the limited field 302K, therefore become the next candidate that goes up envelope curve.

Thus, extract end points 301, some C, G, Ia, K, N, as the candidate point of last envelope curve.Here; For with the value of the corresponding envelope curve of X coordinate (constantly) of the some B that does not become the candidate that goes up envelope curve, D, E, F, H, J, L, M, will be through the value of the value conduct on the straight line of the nearest envelope curve candidate point in each point front and back with the corresponding envelope curve of each X coordinate (constantly).For example, be to provide with the corresponding point of going up on the envelope curve of the X coordinate (constantly) of an E by straight line parallel with the Y axle and the intersection point of straight line CG through an E.Thus, generate the candidate point of counting the last envelope curve 321A of Snum equal number with sampled data.

Then, in the step S604 of Fig. 9, the right endpoint beginning that the envelope curve generation portion 32 of Fig. 6 sets from step S602 along the negative direction of time shaft, extracts the data point that becomes the candidate that goes up envelope curve from time series data 320.Step S604 carries out the processed steps identical with step S603 along the opposite direction on the time shaft.

Figure 11 is the figure of processing sequence that is used for the step S604 of key diagram 9.In Figure 11, identical with Figure 10, schematically show the 14 initial data points A to N of time series data 320.In Figure 11, the left side is time data early, and the right side is near data of time.

In Figure 11, establish and extract the candidate point that a N is used as current last envelope curve.Envelope curve generation portion 32 is a benchmark with a N, at the candidate point of exploring envelope curve on the next one on the negative direction of time shaft.At this moment, because some M, L is lower than with a N is the below limited field 305N of benchmark, does not therefore become the candidate that goes up envelope curve.On the other hand, owing to some K with a N be benchmark below limited field 305N and above satisfy the envelope curve condition between the limited field 304N, therefore become the next candidate that goes up envelope curve.

Then, K promptly puts as benchmark with current last envelope curve candidate point in envelope curve generation portion 32, at the candidate point of exploring envelope curve on the next one on the negative direction of time shaft.At this moment, to satisfy with a K be the scope (between below limited field 305K and the top limited field 304K) of the envelope curve condition of benchmark because some I is higher than, and the some Ib of the upper limit of scope that therefore will satisfy the envelope curve condition is as the next candidate point of last envelope curve.

Then, Ib promptly puts as benchmark with current last envelope curve candidate point in envelope curve generation portion 32, at the candidate point of exploring envelope curve on the next one on the negative direction of time shaft.At this moment, because some H, G, F, E, D is lower than with an Ib is the below limited field 305Ib of benchmark, does not therefore become the candidate point of going up envelope curve.On the other hand, owing to some C with an Ib be benchmark below limited field 305Ib and above satisfy the envelope curve condition between the limited field 304Ib, therefore become the next candidate that goes up envelope curve.

Then, C promptly puts as benchmark with current last envelope curve candidate point in envelope curve generation portion 32, at the candidate point of exploring envelope curve on the next one on the negative direction of time shaft.At this moment, be the below limited field 305C of benchmark because some B is lower than with a C, therefore do not become the candidate point of going up envelope curve.On the other hand, owing to some A with a C be benchmark below limited field 305C and above satisfy the envelope curve condition between the limited field 304C, therefore become the next candidate that goes up envelope curve.

Thus, extract some N, K, Ib, C, the A of Figure 11, as the candidate point of last envelope curve.Here; For with the value of the corresponding envelope curve of X coordinate (constantly) of the some B that does not become the candidate that goes up envelope curve, D, E, F, G, H, J, L, M, will be through the value conduct of the point on the straight line of the nearest envelope curve candidate point in each point front and back and the value of the corresponding envelope curve of each X coordinate (constantly).For example, with the corresponding envelope curve of X coordinate (constantly) of an E on point be to provide by straight line parallel with the Y axle and the intersection point of straight line CIb through an E.Thus, generate the candidate point of counting the last envelope curve 321B of Snum equal number with sampled data.

Below, with reference to Figure 12, to summarizing with the step S603 of the illustrated Fig. 9 of above-mentioned Figure 10, Figure 11 and the order of S604.

Figure 12 is the process flow diagram of order of step S603 and the S604 of presentation graphs 9.In Figure 12, show that (X0 is Y0) to setting next candidate point (Xn, the order till Yn) from current candidate point.In addition, the difference of the step S603 of Fig. 9 and step S604 is, in following step S632 is to obtain next data point, or obtain next data point along the negative direction of time shaft along the positive dirction of time shaft.

In the step S631 of Figure 12, the envelope curve generation portion 32 that establishes Fig. 6 extract the current candidate point of envelope curve (X0, Y0).

In next procedure S632, envelope curve generation portion 32 from the time series data 320 of differential push-pull signals DP P, along time shaft positive dirction (under the situation of step S604 for negative direction) obtain current candidate point (X0, next data point Y0) (Xn, Yn).

In next procedure S633, envelope curve generation portion 32 with current candidate point (X0, Y0) as benchmark, judge the data point in step S632, obtained (Xn, Yn) whether by below limits value LL1 regulation below more than the limited field.That is, (whether Xn Yn) satisfies following formula (5) to envelope curve generation portion 32 decision data point.

LL1×|Xn-X0|≤Yn-Y0 (5)

Under the situation that does not satisfy following formula (5) (among the step S633 for not), envelope curve generation portion 32 returns processing to step S632, along time shaft positive dirction (being negative direction under the situation of step S604) obtain next data point (Xn, Yn).After this, in step S633, envelope curve generation portion 32 judges whether satisfy following formula (5) for the data point of newly obtaining.

Under the situation that satisfies following formula (5) (among the step S633 for being), then execution in step S634.In next procedure S634, envelope curve generation portion 32 with current candidate point (X0, Y0) as benchmark, judge the data point in step S632, obtained (Xn, Yn) whether by above limits value UL1 regulation above below the limited field.That is, (whether Xn Yn) satisfies following formula (6) to envelope curve generation portion 32 decision data point.

Yn-Y0≤UL1×|Xn-X0| (6)

Under the situation that satisfies following formula (6) (among the step S634 for being), then execution in step S635.In step S635, (Xn Yn) is set at the next candidate that goes up envelope curve, and each order of Figure 12 finishes with the data point of obtaining among the step S632 in envelope curve generation portion 32.

On the other hand, (being not among the step S634) advances to step S636 under the situation that does not satisfy following formula (6).In step S636, envelope curve generation portion 32 will satisfy the upper limit of following formula (6) point (Xn, UL1 * | Xn-X0|) be set at the next candidate that goes up envelope curve, each order of Figure 12 finishes.

Once more with reference to Fig. 9, in step S605, the averaging of extraction result of the extraction result of the envelope curve of 32 couples of step S603 of envelope curve generation portion of Fig. 6 and the envelope curve of step S604.

Figure 13 is the figure of processing sequence that is used for the step S605 of key diagram 9.In Figure 13, identical with Figure 10, Figure 11, schematically show the 14 initial data points A to N of time series data 320.In addition, also show last envelope curve 321A that generates by step S603 and the last envelope curve 321B that generates by step S604 among the figure.

Particularly; Each X coordinate (constantly) of the time series data 320 of Snum is counted corresponding to sampled data by envelope curve generation portion 32, calculates the candidate point of the envelope curve 321A that is generated by step S603 and by the mean value 321C of the candidate point of the envelope curve 321B of step S604 generation.The mean value 321C that is calculated uses circular icon representation in the drawings.

Then, in the step S606 of Fig. 9,32 pairs in the envelope curve generation portion of Fig. 6 is handled by the smoothing that the data after the averaging of step S605 (Figure 13 with reference to label 321C) are carried out time-axis direction.At this moment, smoothing is handled and is carried out through moving average.Under the situation of embodiment 1, a front and back EAvnum data of each data point of use envelope curve are carried out the calculating of moving average.Here, moving average data are counted EAvnum and in step S601, are initially set 60.But, under the situation of the left end point of envelope curve, be to use point to calculate moving average in the later moment of left end point, under the situation of the right endpoint of envelope curve, be to use the point in the moment before right endpoint to calculate moving average.

In next procedure S607, the last envelope curve that step S606 generated that the envelope curve generation portion of Fig. 6 32 uses by the front carries out noise removal process to the time series data 320 as the differential push-pull signals DP P of the input data of computing machine 201.That is, in envelope curve generation portion 32 each data point, surpass predetermined threshold and the data point that breaks away from envelope curve is come removal from time series data 320 as noise with very first time sequence data 320.

Figure 14 is the figure of processing sequence that is used for the step S607 of key diagram 9.In Figure 14, identical with the situation of Figure 10 to Figure 13, schematically show the 14 initial data points A to N of time series data 320.In addition, also show by step S606 and carry out the last envelope curve 321D after the smoothing.In data point A to N, the some I that is much higher than the last envelope curve 321D after the smoothing becomes the noise remove object-point.

Particularly; The ratio of Y coordinate that each data point A to N calculates in envelope curve generation portion 32 and the value of the last envelope curve 321D of the X coordinate of each data point A to N surpasses the ratio of being calculated by the data point of the noise remove grade Nrej of the step S601 setting object as noise remove.For example, the Y seat target value of establishing the some I of Figure 14 is 6.5, and the value of the last envelope curve 321D of the X coordinate XI of the I that sets up an office is 5.0.Because ratio between two is 6.5/5.0=1.3, surpass noise remove grade Nrej=1.2.Consequently, the some I of Figure 14 becomes the noise remove object.

Then, the method for the some I with Figure 14 being removed as noise describes.Under the situation of removing some I; Focus G and some K; Above-mentioned some G be among the above-mentioned step S603 along the time shaft positive dirction explore under the situation that goes up envelope curve, the candidate point of previous the last envelope curve of some I, above-mentioned some K explores under the situation that goes up envelope curve, puts the candidate point of the previous last envelope curve of I along the time shaft negative direction among the above-mentioned step S604.G will put as the below limited field 303G of benchmark with will put K and compare as the below limited field 305K of benchmark in 32 pairs in envelope curve generation portion; Selection is set the point of instead putting I less than the below limited field 303G of the value of the X coordinate XI of an I with the some Ic littler than this below limited field 303G.Like this some Ic of new settings after when extracting envelope curve again among the step S608, S609 that state, owing to, therefore do not become the candidate that goes up envelope curve less than the below limited field.

Then, in the step S608 of Fig. 9, the time series data 320 of the differential push-pull signals DP P among 32 couples of step S607 of envelope curve generation portion of Fig. 6 behind the noise remove is carried out along the extraction again of the last envelope curve of time shaft positive dirction.Although the processing of step S608 is identical with the processing of step S603 basically; But its processing with step S603 have 2 different; Any is that input signal is the time series data 320 behind the noise remove, on the other hand uses the second top limits value UL2 and the second below limits value LL2 to replace the first top limits value UL1 and the first below limits value LL1.Because other processing of step S608 are identical with the processing of step S603, therefore do not repeat explanation.

In next procedure S609, the time series data 320 of the differential push-pull signals DP P among 32 couples of step S607 of envelope curve generation portion of Fig. 6 behind the noise remove is carried out along the extraction of the last envelope curve of time shaft negative direction.The processing of step S609 and the processing of step S604 have 2 different; Any is that input signal is the time series data 320 behind the noise remove, on the other hand uses the second top limits value UL2 and the second below limits value LL2 to replace the first top limits value UL1 and the first below limits value LL1.Because other processing of step S609 are identical with the processing of step S604, therefore do not repeat explanation.

In next procedure S610, the averaging of extraction result of the extraction result of the envelope curve of 32 couples of step S608 of envelope curve generation portion of Fig. 6 and the envelope curve of step S609.Because concrete contents processing is identical with the contents processing of step S605, therefore do not repeat explanation.

In next procedure S611,32 pairs of smoothing processing of carrying out time-axis direction by the data after the averaging of step S610 of the envelope curve generation portion of Fig. 6.Because concrete contents processing is identical with the contents processing of step S606, therefore do not repeat explanation.

In next procedure S612, the result of output step S611 finishes to generate the processing of going up envelope curve.

After this, the time series data 320 of 30 pairs of differential push-pull signals DPs of waveform extracting part P of Fig. 6 generates down envelope curve.Owing to the genesis sequence of following envelope curve with make the processing after the Y axle reverses identical with the genesis sequence of going up envelope curve discussed above, so do not repeat explanation.

Figure 15 is the figure of the envelope curve up and down 321,322 that generates based on time series data shown in Figure 8 320 of expression.According to above-mentioned order, through generating envelope curve 321,322 up and down, can not receive the influence of outstanding up and down a plurality of noise signals 83, and the envelope curve 321,322 of rise time sequence data 320.

(the step S505 of generation-Fig. 7 of low frequency waveform)

Figure 16 is the figure of expression according to the low frequency waveform 323 of 321,322 generations of envelope curve up and down of Figure 15.In addition, low frequency waveform 323 is corresponding to first waveform of the present invention.

As with reference to Fig. 4 (A) to Fig. 4 (C) illustrated; In the testing fixture 11 of the light picker of embodiment 1, can take out the waveform (low frequency waveform) of the frequency component that changes corresponding to the displacement of object lens 107 based on the time series data of differential push-pull signals DP P.At this moment, though also consider to use the frequency resolution method of Fourier parsing etc., if carry out the calculating of fast Fourier transform etc., then signal resolution expends time in, and is difficult to carry out at short notice the adjustment of light picker.Therefore, the testing fixture 11 of the light picker of embodiment 1 utilizes the envelope curve of the time series data of differential push-pull signals DP P to take out the low frequency waveform.Particularly, that kind shown in figure 16, the waveform that the waveform operational part 33 of Fig. 6 generates the difference that goes up envelope curve 321 and following envelope curve 322 is as low frequency waveform 323.

In addition, using the calculation method of the low frequency waveform of envelope curve up and down is according to the characteristic of original time series data and difference.Under the situation of differential push-pull signals DP P, the difference of envelope curve is optimal as the low frequency waveform although calculate up and down, under the situation about also having, will go up the average of envelope curve and play envelope curve according to waveform input signal or is best with exporting as the low frequency waveform.

One of them policy is; In that kind shown in figure 15, at envelope curve on the waveform input signal 321 and following envelope curve 322 is under the situation of anti-phase; Promptly last envelope curve 321 be the peak at present envelope curve 322 for paddy, on envelope curve 321 for paddy at present envelope curve 322 for the such situation in peak under; Preferably that kind shown in figure 16 exports the difference of last envelope curve 321 and following envelope curve 322 as low frequency waveform 323.On the other hand; As state after among Figure 27 promote mainly the time series data 328 of drawing signal MPP, be under the situation of homophase at last envelope curve 329 and following envelope curve 330; Promptly last envelope curve 329 be the peak at present envelope curve 330 also for the peak, on envelope curve 329 for paddy at present envelope curve 330 also for the such situation of paddy under, preferably will go up the average of envelope curve and play envelope curve or with export as low frequency waveform 331.Perhaps under the similar situation of shape of the shape of last envelope curve and play envelope curve, also can either party envelope curve be exported as low frequency waveform 331.The waveform (low frequency waveform) of the frequency component that changes thus, corresponding to the displacement of object lens 107 be based on arbitrary side of envelope curve up and down or up and down envelope curve and or the waveform of the difference of envelope curve up and down.

(the step S506 of minimizing calculating-Fig. 7)

Figure 17 is the process flow diagram of the order of the step ST506 of presentation graphs 7 in more detail.Below, suitably with reference to process flow diagram and Figure 18 to Figure 21 of Figure 17, a plurality of minimizing order of calculating low frequency waveform 323 is described.In the initial step S551 of Figure 17, the sample waveform generation portion of Fig. 6 41 generates sample waveform according to low frequency waveform 323.

Figure 18 is the figure of processing sequence that is used to explain the step S551 of Figure 17.With reference to Figure 18, the sample waveform generation portion 41 of Fig. 6 counts DSnum according to interval censored data low frequency waveform 323 is divided into a plurality of intervals.Under the situation of embodiment 1, in the step S501 of Fig. 7, import 50 in advance and count DSnum as interval censored data.Then, sample waveform generation portion 41 is through calculating the point (that is, smallest point) that becomes minimum value respectively and arrange this smallest point by the time sequence to each 50 interval data points, thereby generates sample waveform.

Figure 19 is the figure of the sample waveform 324 that generates among the step S551 of expression Figure 17.Although the shape of sample waveform 324 is roughly identical with low frequency waveform 323, the data number of sample waveform 324 is the 1/DSnum that the data of low frequency waveform 323 are counted Sunm.

Then, in the step S552 of Figure 17, the sample waveform 324 that generates among 42 couples of step S551 of the smoothing portion of Fig. 6 carry out smoothing generate the smoothing waveform (with reference to Figure 20 with reference to label 325).The smoothing of this moment is handled and is carried out through moving average.Under the situation of embodiment 1, a front and back DAvnum data of each data point of use sample waveform 324 are carried out the calculating of moving average.Here, moving average data are counted DAvnum and in step S501, are initially set 11.But, under the situation of the left end point of sample waveform 324, be to use point to calculate moving average in the later moment of left end point, under the situation of the right endpoint of sample waveform 324, be to use the point in the moment before right endpoint to calculate moving average.

Then, in the step S553 of Figure 17, the minimal point extraction portion 43 of Fig. 6 extracts the position of the minimal point of the sample waveform 324 of being calculated by step S552.The minimal point of this moment is and the corresponding point of the paddy portion of differential push-pull signals DP P.In addition, according to the define method of low frequency waveform 323, for example, take place to need to extract the maximal point of sample waveform 324 under the situation of counter-rotating at label that makes low frequency waveform 323 and above-mentioned situation.

Figure 20 is the figure of processing sequence that is used to explain the step S553 of Figure 17.With reference to Figure 20,43 pairs of sample waveforms of minimal point extraction portion of Fig. 6 324 compare with smoothing waveform 325, and extracting the value that deducts behind the smoothing waveform 325 from sample waveform 324 becomes negative a plurality of intervals (being called between minus zone).Under the situation of Figure 20; Between minus zone be interval [S1, T1], [S2, T2] ... [S5; T5], be to begin to be higher than the interval of the some Ti (i is an integer) of smoothing waveform 325 once more to sample waveform 324 from the some Si (i is an integer) that sample waveform 324 is lower than smoothing waveform 325.Between a plurality of minus zones, in each interval of [Si, Ti], infer the minimal point of sample waveform 324.Thereby minimal point extraction portion 43 extracts the position of the minimum value of [Si, Ti] between each minus zone as minimal point.In the example of Figure 20, extract these five minimal points from V1 to V5.

Then, in the step S554 of Figure 17, the position of the minimal point position of the minimal point V1 to V5 of the sample waveform 324 that decision is equivalent to be extracted by step S553, on the low frequency waveform 323.In embodiment 1, some interval censored datas that the minimal point of sample waveform 324 is equivalent on the low frequency waveform 323 are counted the interval smallest point of DSnum (=50 point).Thereby the minimal point of sample waveform 324 becomes the minimal point on the low frequency waveform 323.

Figure 21 is the figure that is illustrated in the position of the minimal point V1 to V5 of decision on the low frequency waveform 323.The step of the minimal point of extraction low frequency waveform 323 shown in Figure 17 leaves it at that.

(judging the whether step S507 of good-Fig. 7 of light picker)

Figure 22 is the process flow diagram of the order of the step ST507 of presentation graphs 7 in more detail.Whether the deviation of the position of the minimal point V1 to V5 on the low frequency waveform 323 that the detection unit 50 of Fig. 6 is calculated according to the step S506 by Fig. 7 comes the diffraction grating 104 of process decision chart 1 good with respect to the configuration (position and posture) of laser light source 102.

At first, in the step S651 of Figure 22, the extreme value division 51 of Fig. 6 will be calculated a plurality of minimal points that portion 40 calculates by extreme value and will be categorized as first and second group.Under the situation of embodiment 1, extreme value division 51 comes alternately to be categorized as first, second group with a plurality of minimal point V1 to V5 according to the time series order.Under the situation of above-mentioned Figure 21, with minimal point V1, V3, and V5 be categorized as first group, minimal point V2, V4 are categorized as second group.Such classification the reasons are as follows said.

In the testing fixture 11 of the light picker of embodiment 1, the object lens 107 that detect the Fig. 1 that sends as an envoy to are the differential push-pull signals DP P of displacement under the situation of interior all sides of the radial direction of optical recording media 106 and outer circumferential side repeatedly.In this case, the amplitude of the time series data of differential push-pull signals DP P periodically changes, the paddy of the amplitude in alternately occurring object lens 107 are displaced under the situation of all sides and object lens 107 are displaced to the paddy of the amplitude under the situation of outer circumferential side.Thereby; Through a plurality of minimal points of low frequency waveform are alternately classified according to the time series order, thus the amplitude of the differential push-pull signal when amplitude and the object lens 107 that can be categorized as object lens 107 differential push-pull signals DP P during all sides in being displaced to are displaced to outer circumferential side.

Then, in the step S652 of Figure 22, the mean value of the value (minimal value) of minimal point is calculated by the comparison portion 52 of Fig. 6 to first, second group.Then, in next procedure S653, comparison portion 52 judges that the ratio of mean values of each group is whether in preset range.Particularly; Comparison portion 52 the absolute value of the difference of the ratio of mean value and 1 be by the situation below the good decision threshold Th (Th=0.05) of the step S501 input of Fig. 7 under; Being configured to of judgement diffraction grating is good, surpasses under the situation of good decision threshold Th at it, is judged to be bad.Whether good order leaves it at that in the configuration of judgement diffraction grating 104.

(summary)

Testing fixture 11 according to the light picker of such embodiment 1; The deviation of the value (minimal value) of the minimal point V1 to V5 through estimating the low frequency waveform 323 from the time series data of differential push-pull signals DP P, extract can be carried out the inspection of light picker 101 accurately.Its result is, can suppress the deviation of adjustment of position and the posture of diffraction grating 104, can shorten the adjustment time, cut down manpower expense etc.

Particularly, the waveform of the difference of the envelope curve up and down 321,322 of the time series data 320 of generation differential push-pull signals DP P is as the waveform (low frequency waveform) 323 of the frequency component that changes corresponding to the periodic displacement of object lens 107.

In addition; Envelope curve is 321,322 o'clock about generating from time series data; Because the oscillation amplitude change of restriction envelope curve 321,322; So that the slope of the straight line through consecutive point, also can suppress The noise and generate envelope curve 321,322 even therefore comprise under the situation of noise signal 83 in time series data below the limits value UL1 and first above in the of first between the limits value LL1.

In addition; Generating up and down each envelope curve from time series data at 321,322 o'clock; Because to envelope curve that generates along the time shaft positive dirction and the averaging of envelope curve that generates along the time shaft negative direction; And further through moving average the envelope curve after the averaging is carried out smoothing and generate final envelope curve, even therefore comprise under the situation of noise component, also can generate envelope curve 321,322 accurately in original time series data.

In addition; Behind envelope curve about the generation once; The data point of envelope curve removes as noise with breaking away from up and down above noise remove grade Nrej in the time series data, owing to use the time series data behind the noise remove to come to generate once more envelope curve, therefore can generate envelope curve more accurately.

In addition, as the end points of the envelope curve that extracts 321,322 o'clock starting point of each envelope curve up and down,, therefore can remove the computational accuracy that The noise improves envelope curve owing to be set to avoiding the specific data point such as initial or final of time series data.

In addition; When extracting the minimal point V1 to V5 of low frequency waveform 323; Owing to use the sample waveform 324 behind the data number of having cut down low frequency waveform 323 to extract minimal point V1 to V5, therefore can reduce the noise component that is comprised in the original low frequency waveform 323, come to extract accurately minimal point V1 to V5.。In addition, owing to use the sample waveform 324 after the data number is cut down to extract minimal point V 1, therefore can shorten the processing time of computing machine to V5.In addition; Because utilization has been carried out the smoothing waveform 325 after the smoothing through moving average to sample waveform 324 and has been extracted minimal point V1 to V5; Even therefore under the significant situation of the oscillation amplitude change of low frequency waveform 323, also can detect the position of minimal point V1 to V5 accurately.Consequently, can improve detection unit 50 and judge whether good precision.

In addition; In detection unit 50; When being displaced to interior all side of optical recording media 106 through a plurality of minimal point V1 to V5 being categorized as object lens 107 when being displaced to outer circumferential side; And the mean value of the value of these minimal points behind the comparison-of-pair sorting (minimal value), thereby can judge accurately whether light picker 101 is good.

(with the comparison of prior art)

Below, to the calculation method of the generation method of the envelope curve in the embodiment 1 and extreme value with utilize the method for prior art to compare.

Figure 23 is the figure of an example of expression differential push-pull signal.The X axle express time axle of Figure 23, the Y axle is represented the signal intensity of differential push-pull signal.In the method shown in the embodiment 1; In order to calculate the amplitude of three the arrow parts (1001,1002,1003) among the figure in the differential push-pull signal; Through obtaining as the envelope curve of the approximate shape of signal waveform earlier, confirm the minimal point of envelope curve and the position of maximal point again, thereby calculate amplitude.

The above-mentioned open patent 2007-209782 of Japan communique (patent documentation 2) though in first prior art that disclosed also in the parsing of signal waveform, use envelope curve, the calculation method of envelope curve is different with the situation of embodiment 1.Under the situation of first prior art, a little bigger and utilize linear interpolation or cubic spline method to come the local pole of being calculated to carry out interpolation between a little bigger through the local pole of calculating waveform input signal on generating during envelope curve, go up envelope curve thereby generate.In addition, when generating down envelope curve, the local minimum point through calculating waveform input signal also utilizes linear interpolation or the cubic spline method is come carrying out interpolation between the local minimum point of being calculated, thereby generates time envelope curve.

Thus, if use first prior art to calculate the envelope curve up and down of the differential push-pull signal of Figure 23, then can receive the influence of the noise (1004,1005,1006) of the part among Figure 23.Have again,, therefore can't correctly depict near the paddy portion (minimal point) 1007 of envelope curve owing to use local pole a little bigger.For following envelope curve also is identical, owing to use local minimum point, therefore can't correctly depict down near the peak portion (maximal point) 1008 of envelope curve.Different therewith is under the situation of embodiment 1, owing to when suppressing The noise, correctly depict envelope curve up and down, therefore can obtain high-precision envelope curve.

In addition; If according to second prior art that discloses in the open patent 2004-79079 of the Japan communique (patent documentation 3); Then through the variation of the value of tracking error signal is shifted and judged to reducing tendency from increasing tendency, thereby detect maximal point.In addition, through the variation of the value of tracking error signal is shifted and judged to increasing tendency from reducing tendency, thereby detect minimal point.Have, in second prior art, for the possibility that is reduced in the bigger tracking error signal of noise, flase drop is measured ghost peak, thereby the peak number that will between zero crossing, detect is defined as one again.

Thus, if use second prior art to detect the maximal point and the minimal point of waveform shown in Figure 24, then there is the problem that only detects a point of maximal point 1011 and can't detect minimal point 1012 and maximal point 1013.Different therewith is under the situation of the embodiment 1 that extracts maximal point and minimal point through smootherization waveform, can correctly obtain the position of maximal point and minimal point.

[variation of embodiment 1]

Below, the method for the maximal point of the low frequency waveform 323 of obtaining Figure 16 is replenished as the variation of embodiment 1.Under the situation of the maximal point of obtaining low frequency waveform 323, also identical with the situation of obtaining minimal point, calculate according to each step of Figure 17.

At first, in the step S551 of Figure 17, the sample waveform generation portion of Fig. 6 41 generates sample waveform according to low frequency waveform 323.At this moment, that kind shown in figure 18, the sample waveform generation portion 41 of Fig. 6 counts DSnum according to interval censored data low frequency waveform 323 is divided into a plurality of intervals.Then, sample waveform generation portion 41 becomes peaked point (that is, maximum point) and arranges this maximum point by the time sequence through each 50 interval data points is calculated respectively, thereby generates sample waveform.

Figure 25 is the figure of the sample waveform 326 that generates among the step S551 of expression Figure 17.Although the shape of the sample waveform of Figure 25 326 roughly sample waveform 324 with Figure 19 is identical; But under the situation of Figure 19, be to utilize each interval smallest point of Figure 18 to generate sample waveform, on the contrary; Under the situation of Figure 25, be to utilize each interval maximum point of Figure 18 to generate sample waveform.

Then, in the step S552 of Figure 17, the sample waveform 326 that generates among 42 couples of step S551 of the smoothing portion of Fig. 6 carry out smoothing generate the smoothing waveform (with reference to Figure 26 with reference to label 327).The smoothing of this moment is handled and is carried out through moving average.Under the situation of the variation of embodiment 1, be to use the front and back DAvnum data of each data point of sample waveform 326 to carry out the calculating of moving average.Here, moving average data are counted DAvnum and in step S501, are initially set 11.But, under the situation of the left end point of sample waveform 326, be to use point to calculate moving average in the later moment of left end point, under the situation of the right endpoint of sample waveform 326, be to use the point in the moment before right endpoint to calculate moving average.

Then, in the step S553 of Figure 17, the maximal point extraction portion 43 of Fig. 6 extracts the position of the maximal point of the sample waveform 326 of being calculated by step S552.

Figure 26 is the figure of processing sequence that is used to explain the step S553 of Figure 17.With reference to Figure 26,43 pairs of sample waveforms of maximal point extraction portion of Fig. 6 326 compare with smoothing waveform 327, and extracting from sample waveform 326 values that deduct behind the smoothing waveform 327 becomes positive a plurality of intervals (being called positive interval).Under the situation of Figure 26; Positive interval be interval [P1, Q1], [P2, Q2] ... [P5; Q5], be to begin to be lower than the interval of the some Qi (i is an integer) of smoothing waveform 327 once more to sample waveform 326 from the some Pi (i is an integer) that sample waveform 326 is higher than smoothing waveform 327.In each interval of a plurality of positive intervals [Pi, Qi], infer the maximal point of sample waveform 326.Therefore, maximal point extraction portion 43 extracts the position of the maximum point of each positive interval [Pi, Qi] as maximal point.In the example of Figure 26, extract these 5 maximal points from R1 to R5.

Then, in the step S554 of Figure 17, the position of the maximal point position of the maximal point R1 to R5 of the sample waveform 326 that decision is equivalent to be extracted by step S553, on the low frequency waveform 323.In embodiment 1, some interval censored datas that the maximal point of sample waveform 326 is equivalent on the low frequency waveform 323 are counted the interval maximum point of DSnum (=50 point).Thereby the maximal point of sample waveform 326 becomes the maximal point on the low frequency waveform 323.The step of the maximal point of extraction low frequency waveform 323 shown in Figure 17 leaves it at that.

[embodiment 2]

Whether the testing fixture 11 of embodiment 1 is only to use differential push-pull signals DP P to come the configuration of diffraction grating 104 of process decision chart 1 good as tracking error signal.Under the situation of embodiment 2, testing fixture 11 judges except using differential push-pull signals DP P, also using to promote mainly and draw signal MPP and be used as tracking error signal whether the configuration of diffraction grating 104 is good.Thus, can further improve the precision of judging that light picker is whether good.

The signal resolution order of promoting mainly the time series data of drawing signal MPP here, the roughly parsing order with the time series data of differential push-pull signals DP P is identical.Thereby the formation of the testing fixture 11 of Fig. 6 and the process flow diagram of Fig. 7 roughly can be shared under the situation of the situation of embodiment 1 and embodiment 2.Below, serve as main describing with situation different portions with embodiment 1, do not repeat shared part is described.

At first, under the situation of embodiment 2, in the step S503 of Fig. 7, the storage part 23 of Fig. 6 is except the time series data of storage differential push-pull signals DP P, and also the time series data of drawing signal MPP is promoted mainly in storage.

Then, under the situation of embodiment 2, in the step S504 of Fig. 7, the end points of each envelope curve up and down also further to promoting mainly the time series data of drawing signal MPP, is set in the end points configuration part 31 of Fig. 6.Then, envelope curve generation portion 32 generates each envelope curve up and down also further to promoting mainly the time series data of drawing signal MPP.

Figure 27 representes to promote mainly the figure of time series data 328 of drawing signal MPP and the envelope curve 329,330 up and down that is generated.Because the generation method of concrete envelope curve 329,330 is identical with the situation of the differential push-pull signals DP P that is illustrated with reference to Fig. 9 to Figure 15, therefore do not repeat explanation.

Then, under the situation of embodiment 2, in the step S505 of Fig. 7, the waveform operational part of Fig. 6 33 also further generates the low frequency waveform, and this low frequency waveform is the average of the envelope curve up and down of promoting mainly the time series data of drawing signal MPP that generated of step S504.

Figure 28 is the figure of expression according to the low frequency waveform 331 of 329,330 generations of envelope curve up and down of Figure 27.Promoting mainly under the situation of drawing signal MPP, because last envelope curve 329 be a homophase with play envelope curve 330, so the waveform that waveform operational part 33 generates on average (or and) that go up envelope curve 329 and following envelope curve 330 is as low frequency waveform 331.In addition, under the situation of Figure 28, because the shape of the shape of last envelope curve 329 and following envelope curve 330 is similar, therefore also can be with any waveform as the low frequency waveform.Low frequency waveform 331 is corresponding to second waveform of the present invention.

Then, under the situation of embodiment 2, in the step S506 of Fig. 7, the extreme value of Fig. 6 is calculated portion 40 also further to calculating minimal point based on promoting mainly the low frequency waveform 331 of drawing signal MPP.Because the calculation method of concrete minimal point is identical with the situation of the differential push-pull signals DP P that is illustrated with reference to Figure 17 to Figure 21, therefore do not repeat explanation.

Then, the determination processing to the step S507 of Fig. 7 describes.Under the situation of embodiment 2, the difference of the situation of itself and embodiment 1 is the sorting technique of the extreme value of the low frequency waveform 323 in the step S651 of Figure 22.Because step S652, the S653 of Figure 22 are identical with the situation of embodiment 1, therefore do not repeat explanation.

Figure 29 is the figure of sorting technique of a plurality of minimal points that is used for explaining the low frequency waveform 323 of embodiment 2.In Figure 29; Show low frequency waveform 323 and low frequency waveform 331; Above-mentioned low frequency waveform 323 is envelope curve up and down poor of the time series data of differential push-pull signals DP P, and above-mentioned low frequency waveform 331 is envelope curve up and down average of promoting mainly the time series data of drawing signal MPP.323,331 pairs of shared time shafts of low frequency waveform (X axle) are represented.In addition, that kind shown in figure 29 in the step S506 of Fig. 7, extracts minimal point Va1 to Va5 to low frequency waveform 323, and low frequency waveform 331 is extracted minimal point Vb1, Vb2.

Under the situation of embodiment 2; In the step S651 of Figure 22; The extreme value division 51 of Fig. 6 will roughly be categorized as first group with minimal point Vb1, the Vb2 of low frequency waveform 331 at minimal point Va2, the Va4 of the low frequency waveform 323 that the identical moment obtains, with remaining minimal point Va1, Va3, and Va5 be categorized as second group.Its effect is described below.

As explaining, the situation that is displaced to interior all sides and the outer circumferential side of optical recording media 106 respectively corresponding to the object lens 107 of Fig. 1 can obtain the minimal point of low frequency waveform 323.Thereby, under the situation of embodiment 1, a plurality of minimal points are come alternately to be categorized as first group and second group according to time sequencing.

Yet, under the situation of very inadequate situation of the adjustment of diffraction grating or the influence that is disturbed, detect sometimes the object lens 107 that do not correspond to Fig. 1 be displaced in the ghost peak of all sides and outer circumferential side.In this case, if 1 use the method for coming alternately a plurality of minimal points are categorized as first group and second group according to time sequencing, then can't come correctly to classify minimal point corresponding to the displacement of object lens 107 like the enforcement mode.

Therefore; In embodiment 2; The extreme value division 51 of Fig. 6 utilizes based on the minimal point Vb1, the Vb2 that promote mainly the low frequency waveform 331 of drawing signal MPP, will be categorized as first group and remaining second group corresponding to minimal point Vb1, Vb2 based on the minimal point Va1 to Va5 of the low frequency waveform 323 of differential push-pull signals DP P.Thus, can judge more accurately whether the configuration of diffraction grating 107 is good than the situation of embodiment 1.

In addition, also can be different with above-mentioned situation, utilize based on a plurality of maximal points of promoting mainly the low frequency waveform 331 of drawing signal MPP, will be categorized as first, second group based on the minimal point Va1 to Va5 of the low frequency waveform 323 of differential push-pull signals DP P.

[embodiment 3]

In embodiment 2, the extreme value division 51 of Fig. 6 is to use based on the arbitrary side in the minimal point of promoting mainly the low frequency waveform 331 of drawing signal MPP or the maximal point, comes the minimal point of differential push-pull signals DP P is classified.In embodiment 3, extreme value division 51 is to use based on the minimal point of promoting mainly the low frequency waveform 331 of drawing signal MPP and this two side of maximal point, comes the minimal point of the low frequency waveform 323 of differential push-pull signals DP P is classified.

Particularly, under the situation of embodiment 3, in the step S506 of Fig. 7, the extreme value of Fig. 6 is calculated 40 pairs in portion based on promoting mainly the low frequency waveform 331 of drawing signal MPP, calculates this two side of minimal point and maximal point.Because the calculation method of concrete minimal point is identical with the explanation among Figure 17 to Figure 21, the calculation method of concrete maximal point is identical with the explanation among Figure 25, Figure 26, does not therefore repeat to specify.

Then, the determination processing among the step S507 of the Fig. 7 under the situation of embodiment 3 is described.

Figure 30 is the figure of sorting technique of a plurality of minimal points that is used for explaining the low frequency waveform 323 of embodiment 3.In Figure 30; Show low frequency waveform 323 and low frequency waveform 331; Above-mentioned low frequency waveform 323 is envelope curve up and down poor of the time series data of differential push-pull signals DP P, and above-mentioned low frequency waveform 331 is envelope curve up and down average of promoting mainly the time series data of drawing signal MPP.Here, 323,331 pairs of shared time shafts of low frequency waveform (X axle) are represented.In addition, that kind shown in figure 30 in the step S506 of Fig. 7, extracts minimal point Va1 to Va5 to low frequency waveform 323, and low frequency waveform 331 is extracted maximal point Rb1 to Rb3 and minimal point Vb1, Vb2.

Under the situation of embodiment 3; In the step S651 of Figure 22; The extreme value division 51 of Fig. 6 will roughly be categorized as first group with minimal point Vb1, the Vb2 of low frequency waveform 331 at minimal point Va2, the Va4 of the low frequency waveform 323 that the identical moment obtains, and minimal point Va1, Va3, the Va5 of the low frequency waveform 323 that roughly obtains in the identical moment with the maximal point Rb1 to Rb3 of low frequency waveform 331 is categorized as second group.

Consequently, if according to the situation of embodiment 3, resulting false minimal point under or the situation such as influence that are disturbed very insufficient in the adjustment of diffraction grating can not be classified as arbitrary group in first, second group yet.Thereby the testing fixture 11 of the light picker of embodiment 3 is compared with the situation of embodiment 2, can judge more accurately whether the configuration of diffraction grating 104 of Fig. 1 is good.In addition, for other situation of embodiment 3, since identical with the situation of embodiment 2, therefore do not repeat explanation.

[embodiment 4]

The testing fixture 11 of the light picker of embodiment 4 is the action of the minimal point extraction portion 43 of Fig. 6 with the difference of the situation of embodiment 1.Particularly, under the situation of embodiment 1, in the step S553 of Figure 17, minimal point extraction portion 43 extracts the position of the smallest point of [Si, Ti] between each minus zone as the minimal point of sample waveform 324.Different therewith is that in embodiment 4, minimal point extraction portion 43 extracts the centre of gravity place of the sample waveform 324 in [Si, Ti] between each minus zone.Then, in the step S554 of Figure 17, the some output on the low frequency waveform 323 that minimal point extraction portion 43 will be corresponding with the centre of gravity place that is extracted is as the minimal point of low frequency waveform 322.

Figure 31 is the figure of processing sequence that is used to explain the step S553 of Figure 17.Figure 31 (A) be expression with the situation of embodiment 1 figure as comparative example, Figure 31 (B) is the key diagram of the situation of embodiment 4.In Figure 31 (A), Figure 31 (B), establish and extract sample waveform and be lower than between the minus zone of smoothing waveform [S1, T1] to [S7, T7].

That kind shown in Figure 31 (A) under the situation of embodiment 1, is extracted the minimal point of each smallest point V1 to V7 of [S1, T1] to [S7, T7] between minus zone as sample waveform.At this moment, [S3, T3] that kind comprises under the situation of a plurality of minimal points between like minus zone, if the smallest point V3 that extracts [S3, T3] between minus zone as minimal point, then causes the position of minimal point is estimated as the position of squinting has taken place along X-direction.

Therefore, through [S3, T3] between minus zone being calculated centre of gravity place, will exporting as minimal point, can reduce skew along X-direction with the some V3_new on the corresponding sample waveform of centre of gravity place.Thus, can improve the judgement precision whether good to final optical Pickup device.The computing method of concrete centre of gravity place are described below.

In Figure 31 (B), suppose straight line SiTi through the point at the two ends of [Si, Ti] between minus zone.In addition, the coordinate of the data point Wi on will sample waveform from a Si to a Ti be made as (Xw, Yw), the coordinate of a Si is made as (Xs, Ys), the coordinate of a Ti is made as (Xt, Yt).Have again, establish through each data point Wi and the coordinate of the intersection point of straight line parallel and straight line SiTi with the Y axle for (Xc, Yc).

For other situation of embodiment 4, since identical with the situation of embodiment 1, therefore do not repeat explanation.In addition,, for example, take place in the label that makes the low frequency waveform and above-mentioned situation under the situation of counter-rotating, need the centre of gravity place in each positive interval of calculating sampling waveform 324 according to the define method of low frequency waveform 323.In this case, maximal point extraction portion 43 will with point on each positive interval corresponding low frequency waveform of centre of gravity place as maximal point.

[embodiment 5]

With reference to Figure 32, the difference of the light picker 101 of light picker 101A and Fig. 1 is, also comprises adjusting mechanism 113 this point, and above-mentioned adjusting mechanism 113 supports diffraction grating 104, and can adjust the position and the posture of diffraction grating 104.Adjusting mechanism 113 is according to the instruction from computing machine 201A, adjusts the position of x axle, y axle, the axial diffraction grating 104 of z and around each angle.Because all the light picker 101 with Fig. 1 is identical for other situation of light picker 101A, therefore, identical or suitable part has been added identical with reference to label, do not repeat explanation.

The automatic regulating apparatus 12 of Figure 32 comprises: error signal generation portion 221, computing machine 201A, and show adjustment result's display equipment 207.Because the formation of error signal generation portion 221 and display equipment 207 is identical with the situation of embodiment 1, therefore do not repeat explanation.

Figure 33 is the block scheme that the software of the computing machine 201A of the expression automatic regulating apparatus 12 that constitutes Figure 32 constitutes.The difference that the software of the computing machine 201 of computing machine 201A and Fig. 6 constitutes is, further comprises diffraction grating adjustment part 24 this point of the adjusting mechanism 113 of controlling diffraction grating 104.The comparative result of diffraction grating adjustment steps 24 according to the comparison portion 52 that constitutes detection unit 50 adjusted the configuration with respect to laser light source 102 of diffraction grating 104.Because it is identical with the situation of the computing machine 201 of Fig. 6 that the software of other of computing machine 201A constitutes all, therefore, identical or suitable part has been added identical with reference to label, do not repeat explanation.

Figure 34 is the adjustment process flow diagram in proper order of the automatic regulating apparatus 12 of expression light picker.The difference of the process flow diagram of Figure 34 and the process flow diagram of Fig. 7 is, after the step S507 of Fig. 7, also comprises step S508, S509 this point.

With reference to Figure 34, the step of the determination processing of step S507 is identical with the situation of embodiment 1.Particularly, the extreme value division 51 of Figure 33 will be calculated a plurality of minimal points that portion 40 calculates by extreme value and will be categorized as first and second group.Extreme value division 51 comes alternately to be categorized as first, second group with a plurality of minimal point V1 to V5 according to the time series order.Then, the comparison portion 52 of Figure 33 organizes the mean value of the value (minimal value) of calculating minimal point to first, second.

Then; In the step S508 of Figure 34; The comparison portion 52 of Figure 33 obtains poor to the ratio of the mean value of each group and 1; Absolute value in the difference of being tried to achieve is under the situation below the good decision threshold Th (Th=0.05) that in step S501, imports, and the configuration of diffraction grating is judged to be well (among the step S508 for being), and the adjustment of the automatic regulating apparatus 12 of light picker finishes in proper order.

On the other hand, the comparison portion 52 of Figure 33 surpasses under the situation of good decision threshold Th at the absolute value to the difference of the ratio of the mean value of each group and 1, and the configuration of diffraction grating is judged to be bad (among the step S508 for not), advances to step S509.

In step S509, the diffraction grating adjustment part 24 of Figure 33 makes adjusting mechanism 113 change the position and the posture of diffraction grating 104 according to the result of determination of comparison portion 52.Specific as follows said.

At first, the good result of determination of each direction of principal axis of the 24 pairs of x axles in diffraction grating adjustment part, y axle, z axle and the state before each angle is with adjustment (to the ratio of the mean value of the extreme value of each group) is stored in the memory storage 203.Then, diffraction grating adjustment part 24 changes the position of diffraction grating 104 or posture positive dirction or the right rotation direction along each.Then, the good result of determination (ratio of the mean value of extreme value) of adjusted state is accepted from comparison portion 52 in diffraction grating adjustment part 24, with compared before the adjustment, judge whether near desired value 1.Under situation near desired value 1, continue the adjustment of equidirectional, until the deviation of good result of determination and desired value in good decision threshold Th.With the bigger situation of the deviation of desired value 1 under, the adjustment direction of each is changed in the other direction.

Carry out the step S502 to S509 of Figure 34 repeatedly, until the deviation that in step S508, is judged to be good result of determination and desired value at good decision threshold Th with interior (become among the step S508 and be).For other the step of Figure 34, because identical, therefore identical or suitable part has been added identically with reference to label with the situation of embodiment 1, do not repeat explanation.

According to the automatic regulating apparatus 12 of the light picker of Figure 34,, can carry out the adjustment of light picker accurately through estimating the minimizing deviation of the low frequency waveform that extracts from the time series data of differential push-pull signals DP P.Consequently, can suppress the adjustment result's of light picker deviation, can shorten the adjustment time, cut down manpower expense etc.

The embodiment that should think here to be disclosed is expression for example in all fields, rather than restrictive.Can think that scope of the present invention is not to be represented by above-mentioned explanation, but represent, can comprise and the equal meaning of claim scope and all changes in the scope by the claim scope.

Claims

1. the testing fixture of a light picker,

Said light picker comprises:

Laser light source;

Beam splitter, this beam splitter carries out shunt to the light that penetrates from said laser light source, makes it be divided into a plurality of light beams that comprise main beam and at least two side beams;

Object lens, these object lens all focus on each light beam of said a plurality of light beams on the optical recording media;

Actuator, this actuator can make said object lens on the direction that the track with said optical recording media intersects, carry out anti-reset and move; And,

A plurality of photodetectors, these a plurality of photodetectors detect a plurality of reflected light that each light beams of said a plurality of light beams is produced respectively after said optical recording media reflects,

Said testing fixture comprises:

Error signal generation portion, this error signal generation portion generate differential push-pull signal based on the output of said a plurality of photodetectors as tracking error signal;

The AD transformation component, this AD transformation component to said object lens carry out on the direction of intersecting with the track of said optical recording media that anti-reset moves during in resulting said differential push-pull signal carry out digital conversion;

Storage part, this storage part have carried out the very first time sequence data after the digital conversion to said differential push-pull signal and have stored; And,

Waveform extracting part, this waveform extracting part is extracted first waveform based on the said very first time sequence data of being stored in the said storage part,

Said first waveform be based on arbitrary side of the envelope curve up and down of said very first time sequence data, up and down envelope curve and or the waveform of the difference of envelope curve up and down,

The testing fixture of said light picker comprises that also extreme value calculates portion and detection unit,

The said extreme value portion of calculating at a plurality of maximum value or minimum values of said first waveform; Said detection unit according to the deviation of a plurality of maximum value or minimum values of said first waveform that utilizes the said extreme value portion of calculating to calculate whether in preset range, thereby judge whether said beam splitter good with respect to the configuration of said laser light source.

2. the testing fixture of light picker as claimed in claim 1 is characterized in that,

Said waveform extracting part comprises:

The end points configuration part, this end points configuration part to said very first time sequence data each up and down envelope curve set at least one side of left and right sides end points; And,

The side through end points of envelope curve generation portion, this envelope curve generation portion from the said left and right sides begin and along the positive dirction or the negative direction of time shaft, from said very first time sequence data, extract the data point that satisfies predetermined condition successively, thereby generate each envelope curve up and down,

Said predetermined condition is meant that straight slope through the consecutive number strong point is in preset range.

3. the testing fixture of light picker as claimed in claim 2 is characterized in that,

Said envelope curve generation portion is through generating each said envelope curve up and down to a plurality of first data points and a plurality of second averaging of data point; Said a plurality of first data point is that the positive dirction along time shaft extracts from said very first time sequence data, and said a plurality of second data points are that the negative direction along time shaft extracts.

4. the testing fixture of light picker as claimed in claim 2 is characterized in that,

The data point of envelope curve from said very first time sequence data, removes as noise about breaking away from said envelope curve generation portion each data point with said very first time sequence data, above predetermined threshold, and use has been removed the said very first time sequence data behind the noise and come to generate once more each envelope curve up and down.

5. the testing fixture of light picker as claimed in claim 2 is characterized in that,

Said end points configuration part is when setting each said left and right sides end points; Arrange from big to small according to the value of data point from said very first time sequence data begin the data point of several predetermined number at first or finally the time, the predetermined several the value of data point is set at the value of end points.

6. the testing fixture of light picker as claimed in claim 1 is characterized in that,

Said extreme value is calculated portion when calculating a plurality of minimal value of said first waveform, comprising:

Sample waveform generation portion, this sample waveform generation portion is divided into a plurality of intervals with said first waveform, generates the sample waveform that each the interval smallest point by said a plurality of intervals forms;

Smoothing portion, this smoothing portion generate said sample waveform are carried out the smoothing waveform after the moving average; And,

Minimal point extraction portion; This minimal point extraction portion extracts the value that deducts behind the said smoothing waveform from said sample waveform to be become between negative a plurality of minus zones, and extracts the minimal point of the smallest point of the said sample waveform in each interval between said a plurality of minus zone as said first waveform.

7. the testing fixture of light picker as claimed in claim 1 is characterized in that,

Said extreme value is calculated portion when calculating a plurality of maximum value of said first waveform, comprising:

Sample waveform generation portion, this sample waveform generation portion is divided into a plurality of intervals with said first waveform, generates the sample waveform that each the interval maximum point by said a plurality of intervals forms;

Maximal point extraction portion; This maximal point extraction portion extracts the value that deducts behind the said smoothing waveform from said sample waveform becomes positive a plurality of positive interval, and extracts the maximal point of the maximum point of the said sample waveform in each interval in said a plurality of positive intervals as said first waveform.

8. the testing fixture of light picker as claimed in claim 1 is characterized in that,

Minimal point extraction portion; This minimal point extraction portion extracts the value that deducts behind the said smoothing waveform from said sample waveform to be become between negative a plurality of minus zones, and extract in each interval between said a plurality of minus zone, with corresponding said first waveform of centre of gravity place of said sample waveform on point as the minimal point of said first waveform.

9. the testing fixture of light picker as claimed in claim 1 is characterized in that,

Maximal point extraction portion; This maximal point extraction portion extracts the value that deducts behind the said smoothing waveform from said sample waveform becomes positive a plurality of positive interval, and extract in each interval in said a plurality of positive intervals, with corresponding said first waveform of centre of gravity place of said sample waveform on point as the maximal point of said first waveform.

10. the testing fixture of light picker as claimed in claim 1 is characterized in that,

Said detection unit comprises:

The extreme value division, this extreme value division will be categorized as first and second group by a plurality of maximum value that the said extreme value portion of calculating, or will be categorized as first and second group by a plurality of minimal values that the said extreme value portion of calculating; And,

Comparison portion; The mean value of this comparison portion through relatively belonging to said first group a plurality of maximum value and the mean value that belongs to said second group a plurality of maximum value; Or belong to said first group a plurality of minimizing mean value and belong to said second group a plurality of minimizing mean value, judge whether said beam splitter is good with respect to the configuration of said laser light source.

11. the testing fixture of light picker as claimed in claim 10 is characterized in that,

Said extreme value division will utilize the said extreme value portion of calculating a plurality of maximum value to come alternately to be categorized as said first and said second group according to the time sequencing of said very first time sequence data, maybe will utilize the said extreme value portion of calculating a plurality of minimal values to come alternately to be categorized as said first and said second group according to the time sequencing of said very first time sequence data.

12. the testing fixture of light picker as claimed in claim 10 is characterized in that,

Said error signal generation portion comes further to generate to promote mainly to draw signal based on the output of photodetector in said a plurality of photodetectors, that the reflected light of said main beam is detected,

Said AD transformation component is drawn signal and is further carried out digital conversion resulting said promoting mainly during carrying out displacement repeatedly at said object lens,

Said storage part is also drawn signal and has been carried out second time series data after the digital conversion and store said promoting mainly,

Said waveform extracting part further extracts second waveform based on said second time series data of being stored in the said storage part,

Said second waveform be based on arbitrary side of the envelope curve up and down of said second time series data, up and down envelope curve and or the waveform of the difference of envelope curve up and down,

A plurality of maximum value or minimum values of said second waveform are also calculated by the said extreme value portion of calculating,

Said extreme value division will utilize in a plurality of maximum value of said first waveform that the said extreme value portion of calculating, utilize the roughly the same resulting maximum value of the moment of the minimizing moment of said second waveform that the said extreme value portion of calculating to be categorized as said first group with providing; Remaining maximum value is categorized as said second group, or

Said extreme value division will utilize in a plurality of maximum value of said first waveform that the said extreme value portion of calculating, be categorized as said first group with the roughly the same resulting maximum value of the moment of the moment that the maximum value of utilizing said second waveform that the said extreme value portion of calculating is provided; Remaining maximum value is categorized as said second group, or

Said extreme value division will utilize in a plurality of minimal values of said first waveform that the said extreme value portion of calculating, utilize the roughly the same resulting minimal value of the moment of the minimizing moment of said second waveform that the said extreme value portion of calculating to be categorized as said first group with providing; Remaining minimal value is categorized as said second group, or

Said extreme value division will utilize in a plurality of minimal values of said first waveform that the said extreme value portion of calculating, be categorized as said first group with the roughly the same resulting minimal value of the moment of the moment that the maximum value of utilizing said second waveform that the said extreme value portion of calculating is provided, remaining minimal value is categorized as said second group.

13. the testing fixture of light picker as claimed in claim 10 is characterized in that,

The a plurality of maximum value and the minimal value of said second waveform are also calculated by the said extreme value portion of calculating,

Said extreme value division will utilize in a plurality of maximum value of said first waveform that the said extreme value portion of calculating, with provide the roughly the same resulting maximum value of the moment of the minimizing moment of said second waveform to be categorized as said first group; To be categorized as said second group with roughly the same resulting maximum value of the moment of the moment of the maximum value that said second waveform is provided, or

Said extreme value division will utilize in a plurality of minimal values of said first waveform that the said extreme value portion of calculating, with provide the roughly the same resulting minimal value of the moment of the minimizing moment of said second waveform to be categorized as said first group, will be categorized as said second group with roughly the same resulting minimal value of the moment of the moment of the maximum value that said second waveform is provided.

14. the inspection method of a light picker, said light picker comprises:

Laser light source;

Beam splitter, said beam splitter carries out shunt to the light that penetrates from said laser light source, makes it be divided into a plurality of light beams that comprise main beam and at least two side beams;

Actuator, this actuator can make said object lens on the direction that the track with said optical recording media intersects, carry out anti-reset and move; And

Said inspection method comprises:

Generation is based on the differential push-pull signal of the output of the said a plurality of photodetectors step as tracking error signal;

With said object lens carry out on the direction of intersecting with the track of said optical recording media that anti-reset moves during in the resulting said differential push-pull signal step of carrying out digital conversion;

Said differential push-pull signal has been carried out the step that the very first time sequence data after the digital conversion is stored; And,

The said very first time sequence data of being stored in the step based on said storage extracts the step of first waveform,

The inspection method of said light picker also comprises:

Calculate the step of a plurality of maximum value or minimum values of said first waveform,

Said first waveform be based on arbitrary side of the envelope curve up and down of said very first time sequence data, up and down envelope curve and or the waveform of the difference of envelope curve up and down;

And according to the deviation of a plurality of maximum value or minimum values of said first waveform of in the said step of calculating, calculating whether in preset range, thereby judge the step that whether good said beam splitter with respect to the configuration of said laser light source.

15. the automatic regulating apparatus of a light picker,

Said light picker comprises:

Laser light source;

Said automatic regulating apparatus comprises:

Storage part, this storage part have carried out the very first time sequence data after the digital conversion to said differential push-pull signal and have stored; And

The automatic regulating apparatus of said light picker also comprises: extreme value is calculated portion, and this extreme value portion of calculating at a plurality of maximum value or minimum values of said first waveform;

Detection unit, this detection unit according to the deviation of a plurality of maximum value or minimum values of said first waveform that utilizes the said extreme value portion of calculating whether in predetermined scope, thereby judge whether said beam splitter good with respect to the configuration of said laser light source; And,

Adjustment part, this adjustment part are adjusted with respect to the configuration of said laser light source said beam splitter according to the result of determination of said detection unit.