CN102456361A - Method and device for compensating spherical aberration of compact disc drive - Google Patents
Method and device for compensating spherical aberration of compact disc drive Download PDFInfo
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Abstract
The invention relates to a method and a device for compensating spherical aberration of a compact disc drive. The method comprises the following steps of measuring a first surface thickness at a first radius position of a compact disc; measuring a second first surface thickness at a second radius position of the compact disc; conducting spherical aberration compensation calibration to a third radius position of the compact disc and obtaining an optimum spherical aberration compensation value; obtaining a spherical aberration function according to the first radius position, the second radius position, the first surface thickness, the second surface thickness and the optimum spherical aberration compensation value at the third radius position; and calculating an updated spherical aberration compensation value according to a fourth radius position of an optical read-write head and the spherical aberration compensation function, and inputting the updated spherical aberration compensation value into a spherical aberration compensator of the compact disc drive. Since the consumption time is very short by using the spherical aberration compensation method, the time spent in the startup procedure of the compact disc drive can be greatly reduced.
Description
Technical field
The present invention relates to a kind of control method and device of CD-ROM drive, and be particularly related to a kind of spherical aberration compensating method and device of CD-ROM drive.
Background technology
See also Fig. 1, it is spherical aberration (spherical aberration, SA) synoptic diagram.When spherical aberration took place, light was through behind remote axis area territory (paraxial zone) A1 of lens 120, and its focus A focuses on the plane 100.And light is through near axis area (axial zone) B1 of lens at this moment, and its focus B focuses on before the said plane 100.Also promptly, when light through lens, the focus in its near axis area and remote axis area territory does not have when overlapping, i.e. representative generation spherical aberration.And spherical aberration also can abbreviate spherical aberration as.
Basically, laser disc top layer (cover layer), or claim that the difference in thickness of clear plastic layer is to cause the main cause of spherical aberration.When spherical aberration produces; The energy that focuses on the laser disc can disperse; Cause regenerated signal (playback signal) (like radiofrequency signal (RF)) and servosignal (servo signal) (like focus error signal FE or stride rail error signal TE)) quality badness, and then influence the performance of CD-ROM drive broadcast video disc.
In order to reduce spherical aberration; A spherical-aberration compensator can be provided in the CD-ROM drive; And in the start-up routine (start up procedure) of CD-ROM drive, add a spherical aberration compensation corrective action (SA calibration), and then obtain a spherical aberration compensation value (SA value).That is to say, after spherical-aberration compensator receives the spherical aberration compensation value, can reduce the influence that spherical aberration causes.Also promptly, make light through behind the remote axis area territory and near axis area of lens, its Focus Club focuses on same position, after the start-up routine completion, CD-ROM drive promptly can the accessed in normal laser disc on data.
In general, the kind of spherical-aberration compensator can be divided into liquid crystal (LCD) spherical-aberration compensator and collimation (collimating) spherical-aberration compensator.The liquid crystal spherical-aberration compensator receives the spherical aberration compensation value and changes the optical path difference (optical path difference) that its inner refractive index (refractive index) is caused in order to reduction lens remote axis area territory and near axis area, and then reduces the influence that spherical aberration caused.And the collimation spherical-aberration compensator receives the spherical aberration compensation value and the relative position that changes its internal optical component (optical element) with the optical path difference that reduces lens remote axis area territory and near axis area and caused and reduce the influence that spherical aberration is caused.
In general; Because CD-ROM drive can be controlled optical read/write head (optical pick up head) and move to the inner circle area (inner area) of laser disc and carry out start-up routine; Therefore, CD-ROM drive carries out the spherical aberration compensation corrective action near the laser disc top layer the laser disc inner circle area.That is to say that the spherical aberration compensation value that obtain this moment is effective for the laser disc inner circle area only.The skin depth of supposing laser disc is very even, and this spherical aberration compensation value also is effective concerning the All Ranges of laser disc.
Yet the uneven situation of rom table layer thickness usually can take place in the process of making in laser disc.If when the inner circle area of laser disc is carried out the spherical aberration compensation corrective action and obtained the spherical aberration compensation value, this spherical aberration compensation value also is not suitable for other zones of laser disc, for example outer collar region (outer area).At this moment, light then will cause the regenerated signal quality variation of the outer collar region of laser disc, heavy then cause optical read/write head can't successfully focus on the outer collar region of laser disc, can't produce regenerated signal at all.
See also Fig. 2 A and Fig. 2 B, it is uneven two types of a rom table layer thickness.Laser disc 200 shown in Fig. 2 A, wherein between the zone be center hole (central hole) 205.The top layer 220 of this laser disc 200 is in uneven thickness, and the surface of inner circle area (surface) is thinner to data Layer 210, and the surface of outer collar region to data Layer 210 is thicker.Laser disc 250 shown in Fig. 2 B, wherein between the zone be center hole 255.The top layer 270 of this laser disc 250 is in uneven thickness, and the surface of inner circle area to data Layer 260 is thicker, and the surface of outer collar region to data Layer 260 is thinner.
In order to solve the inhomogeneous spherical aberration problems that causes of rom table layer thickness effectively, TaiWan, China patent publication No. 200929197 and corresponding U.S. Patent Publication 20090168616 thereof disclose a kind of spherical aberration compensating method (Spherical aberration compensation methodof optical storage device) of light memory device.See also Fig. 3, it is existing spherical aberration compensating method process flow diagram.
After CD-ROM drive started (step 300), mobile optical read/write head to the first orbital position (step 302) also carried out spherical aberration correction and obtains first reference value (step 304); Then, mobile optical read/write head to the second orbital position (step 306) and carry out spherical aberration correction and obtain second reference value (step 308); Promptly begin accessed in normal laser disc data (step 310) this moment, and carry out interior insert (interpolation) to insert spherical aberration compensation value (step 312) in obtaining according to first reference value and second reference value.
Then, insert spherical aberration compensation value and current spherical aberration compensation value whether different (step 314) in the inspection.When inequality, insert spherical aberration compensation value in utilizing and upgrade current spherical aberration compensation value (step 316), and get into step 312; Otherwise, when identical, directly get into step 312, do not do the renewal of spherical aberration compensation value.
Clearly, existing spherical aberration compensating method carries out spherical aberration compensation corrective action (spherical aberration correction) in the inner circle area of laser disc earlier, and obtains the first spherical aberration compensation value (first reference value); Then, carry out spherical aberration compensation corrective action (spherical aberration correction) at the outer collar region of laser disc, and obtain the second spherical aberration compensation value (second reference value).And utilize the first spherical aberration compensation value and the second spherical aberration compensation value promptly can carry out interior inserting, and obtain the interior slotting spherical aberration compensation value (interpolated SAvalue) of any radial location of laser disc.Therefore, when optical read/write head is positioned at any radial location of laser disc, can be with interior slotting spherical aberration compensation value input spherical-aberration compensator, and reduce the influence that spherical aberration caused.
Yet, owing to carry out a spherical aberration compensation corrective action and just need expend many times, so, carry out second time spherical aberration compensation corrective action and can expend more time certainly.Therefore, can prolong the time that the CD-ROM drive start-up routine is spent, and delay the time that CD-ROM drive begins access laser disc data.
If laser disc is the laser disc of two-layer data Layer; Then need respectively carry out the spherical aberration compensation corrective action one time, with the spherical aberration compensation value that obtains inner circle area first data Layer and the spherical aberration compensation value of second data Layer at first data Layer and second data Layer of the inner circle area of laser disc.Afterwards, respectively carry out one time the spherical aberration compensation corrective action again, with the spherical aberration compensation value that obtains outer collar region first data Layer and the spherical aberration compensation value of second data Layer at first data Layer and second data Layer of the outer collar region of laser disc.At last, utilize four spherical aberration compensation values that obtain to carry out interior inserting, obtain the interior slotting spherical aberration compensation value of first data Layer and the interior slotting spherical aberration compensation value of second data Layer.
That is to say that the laser disc of two-layer data Layer must carry out the spherical aberration compensation corrective action four times, so will expend more time, and delayed the time that CD-ROM drive begins access laser disc data widely at initial orders.
Summary of the invention
The objective of the invention is to propose a kind of spherical aberration compensating method and device of CD-ROM drive; Expend more time at start-up routine with what the solution prior art existed; And delay the problem that CD-ROM drive begins the time of access laser disc data; The present invention only needs laser disc is carried out the spherical aberration compensation corrective action one time, and the skin depth variation of collocation laser disc, can obtain the spherical aberration compensation value of different radii position fast.
The present invention proposes a kind of spherical aberration compensating method of CD-ROM drive, comprises the following steps: to measure first skin depth of first radial location of a laser disc; Measure second skin depth of second radial location of laser disc; Carry out the spherical aberration compensation corrective action and obtain a best spherical aberration compensation value in the 3rd radial location of laser disc; According to the best spherical aberration compensation value of first radial location, second radial location, first skin depth, second skin depth, the 3rd radial location, obtain a spherical aberration compensation function; And go out one according to the 4th radial location at optical read/write head place and said spherical aberration compensation function calculation and upgrade the spherical aberration compensation value, an and spherical-aberration compensator of input CD-ROM drive.
The present invention proposes a kind of spherical aberration compensating method of CD-ROM drive, comprises the following steps: to measure first skin depth of first radial location of a laser disc; Measure second skin depth of second radial location of laser disc; According to first radial location, second radial location, first thickness, second thickness, the skin depth that calculates laser disc distributes, and calculates the change trend of spherical aberration compensation value according to this; Read the data of laser disc, and, produce one and upgrade the spherical aberration compensation value according to the change trend of data error rate and spherical aberration compensation value; And with a spherical-aberration compensator of said renewal spherical aberration compensation value input CD-ROM drive.
Therefore, the present invention more proposes a kind of sa compensation means of CD-ROM drive, is connected in an optical read/write head, comprising: stride the rail motor actuator for one, be connected to optical read/write head, with moving radially of control optical read/write head; A spherical-aberration compensator; A focus motor actuator is connected to optical read/write head, with moving of the focus direction of control optical read/write head; A light measurement signal generator receives the light signal that optical read/write head produced, and is converted into a plurality of electric signal; And a digital signal processor is electrically connected to and strides rail motor actuator, spherical-aberration compensator, focus motor actuator and light measurement signal generator; Wherein, Digital signal processor is used to control said optical read/write head and moves to first radial location and second radial location and calculate first skin depth and second skin depth; And carry out a spherical aberration compensation corrective action and obtain best spherical aberration compensation value in the 3rd radial location; And obtain the spherical aberration compensation function according to this, and go out said renewal spherical aberration compensation value according to the 4th radial location and the said spherical aberration compensation function calculation at said optical read/write head place, and the input spherical-aberration compensator.
The present invention only needs to carry out spherical aberration compensation corrective action once in a radial location of laser disc, and obtains the spherical aberration compensation value.Afterwards, according to the variation relation of rom table layer thickness, can extrapolate the spherical aberration compensation value of any radial location.Because the account form of skin depth is very simple, and the unusual weak point of expending time in, therefore the present invention can significantly reduce the time that the CD-ROM drive start-up routine is spent.
Above-mentioned explanation only is the general introduction of technical scheme of the present invention; Understand technological means of the present invention in order can more to know; And can implement according to the content of instructions, and for let of the present invention above-mentioned with other purposes, feature and advantage can be more obviously understandable, below special act preferred embodiment; And conjunction with figs., specify as follows.
Description of drawings
Fig. 1 is the spherical aberration synoptic diagram.
Fig. 2 A and Fig. 2 B are uneven two types of rom table layer thickness.
Fig. 3 is existing spherical aberration compensating method process flow diagram.
The action synoptic diagram of collimation spherical-aberration compensator when Fig. 4 A and Fig. 4 B change for laser disc thickness.
Fig. 5 A to Fig. 5 C adjusts the synoptic diagram of spherical aberration compensation value according to the variation in thickness on laser disc top layer for the present invention.
The coherent signal synoptic diagram of Fig. 6 A to Fig. 6 B when measuring the skin depth of laser disc.
Fig. 7 is the sa compensation means of CD-ROM drive of the present invention.
Fig. 8 is the process flow diagram of spherical aberration compensating method of the CD-ROM drive of first embodiment of the invention.
Fig. 9 is the process flow diagram of spherical aberration compensating method of the CD-ROM drive of second embodiment of the invention.
Embodiment
For further setting forth technological means and the effect that the present invention takes for the predetermined goal of the invention of realization; Below in conjunction with accompanying drawing and preferred embodiment; To the spherical aberration compensating method and embodiment, structure, characteristic and the effect thereof of device of the CD-ROM drive that proposes according to the present invention, specify as after.
See also Fig. 4 A Fig. 4 B, the action synoptic diagram of collimation spherical-aberration compensator when it changes for laser disc thickness.Shown in Fig. 4 A; Collimation spherical-aberration compensator 420 receives the spherical aberration compensation value; And change the distance of first optical element (for example first collimation lens), 422 and second optical element (for example second collimation lens) between 424 according to this; And the reduction spherical aberration, and make laser beam (laser beam) focus accumulated on the data Layer 402 of laser disc 400 via lens 410.
See also Fig. 4 B, when the thickness on laser disc 400 top layers 404 change Δ d, then need change the spherical aberration compensation value, and make the distance of change Δ c between first optical element 422 and second optical element 424 in the spherical-aberration compensator 420.So, can reduce spherical aberration, and make laser beam via lens 410 focus accumulated on the data Layer 402 of laser disc 400 once more.That is to say that if laser disc 400 skin depths increase Δ d, then the spherical-aberration compensator amount that need compensate is Δ c.Therefore, Δ c=K * Δ d, perhaps Δ c=-K * Δ d---(I), the meaning of the sign representative here is exactly the direction that first optical element 422 moves, its sign and can deciding along with the change direction of Δ d.
Its cardinal principle such as following derivation, the refractive index of supposing laser disc top layer 404 is N, when the refraction angle is θ.Utilizing geometric optical theory to analyze the optical path difference of its Axial Bundle paraxial and far away in laser disc changes; In the time of can deriving laser disc top layer 404 thickness increase Δ d; The light near axis area and remote axis area territory arrives focus point can produce optical path difference e, and optical path difference e is the reason that causes spherical aberration.Wherein, e can be expressed as:
Can know by (II) formula; Because the refractive index N on laser disc top layer is only relevant with the material on top layer with refraction angle θ;
can regard fixing constant K as, so optical path difference e is proportional to skin depth difference Δ d.Can know by (I) formula; The design of spherical-aberration compensator is compensation because of the above-mentioned spherical aberration K that optical path difference e caused * Δ d; The optical path difference Δ c that spherical-aberration compensator is produced is equal to K * Δ d; The optical path difference that produces in the time of can revising owing to the change of video disc skin depth has been revised optical path difference and has promptly been revised system's spherical aberration.In other words, can know,, cooperate optical read/write head factory to provide again or test the compensation K value of trying to achieve, can obtain final spherical aberration compensation value Δ c if can learn the variation in thickness Δ d of laser disc by (I), (II).In like manner, utilize the liquid crystal compensation device also can derive the variation in thickness Δ d of laser disc and the relation between the spherical aberration compensation value Δ c, therefore repeat no more.
See also Fig. 5 A to Fig. 5 C, it adjusts the synoptic diagram of spherical aberration compensation value according to the variation in thickness on laser disc top layer for the present invention.At first, shown in Fig. 5 A, optical read/write head can be in 500 two radii positions of laser disc (the for example first radial location r1 and the second radial location r2) obtain first thickness d 1 and second thickness d 2 on top layer 520.The thickness on top layer 520 is the distance of surface between the data Layer 510 of laser disc 500 here.After obtaining second thickness d 2 on first thickness d 1 and the second radial location r2 top layer 520 on top layer, the first radial location r1 place 520, can obtain the linear relationship d (r) between laser disc 500 top layers, 520 thickness and the radius according to this.That is to say,, can learn top layer 520 thickness of laser disc 500 any radial location according to the linear relationship d (r) between laser disc 500 top layers, 520 thickness and the radius.
Can know that by (II) formula the variation of spherical aberration compensation value and top layer 520 thickness is linear.Therefore, can obtain the linear relationship between laser disc 500 radial location and the spherical aberration compensation value via linear mapping.Then, optical read/write head can a radial location in office (for example the 3rd radial location r3) carry out the spherical aberration compensation corrective action and obtain best spherical aberration compensation value c0.Afterwards, the spherical aberration compensation value c=c0+ Δ c in the time of can obtaining any radial location according to the 3rd radial location r3 and best spherical aberration compensation value c0 again, Δ c=K* Δ d.And optical read/write head can be controlled spherical-aberration compensator to reduce spherical aberration according to the spherical aberration compensation value that calculates.Certainly, the 3rd above-mentioned radial location r3 can be identical with the first radial location r1 or the second radial location r2, and the first radial location r1 can be in the inner circle area of laser disc and the second radial location r2 can be at the outer collar region of laser disc.
Can know that by above description spherical aberration compensating method proposed by the invention only needs to carry out spherical aberration compensation corrective action once in a radial location of laser disc, and obtains the spherical aberration compensation value.Afterwards, according to the variation relation of rom table layer thickness, can extrapolate the spherical aberration compensation value of any radial location.Because the account form of skin depth is very simple, and the unusual weak point of expending time in, therefore can significantly reduce the time that the CD-ROM drive start-up routine is spent.
Below introduce in detail the whole bag of tricks that calculates the rom table layer thickness.Basically, (focus motoroutput signal FMO), makes that the lens in the optical read/write head move to comprise its exportable focus motor output signal of a motor driver (not illustrating) in the control module in the CD-ROM drive.Therefore, through the lens that move, the signal that makes laser disc reflex to OPTICAL SENSORS is produced change, and can produce beam intensity signal (BS) and focus error signal (FE) according to this.
In general, the focus motor output signal that output increases progressively, the may command lens move toward the direction of laser disc.And can derive speed that lens move (v) according to the slope of focus motor output signal.See also Fig. 6 A, its coherent signal synoptic diagram when measuring the skin depth of laser disc.The Focus Club of laser beam makes beam intensity signal BS produce the first less peak value of amplitude through the surface of laser disc in regular turn when lens rise; The second bigger peak value of amplitude can appear in beam intensity signal BS when lens continue rising focus arrival data Layer; And calculate this two peak values elapsed time T, can calculate the rom table layer thickness is d=v * T.
Perhaps; The Focus Club of laser beam makes focus error signal FE produce a S curve (s curve) through the superficial layer of laser disc in regular turn when lens rise; When lens continue when the rising focus arrives data Layer; Focus error signal FE produces the 2nd S curve, calculates the time T of this two S curve between zero passage crossover point (zerocrossing point), and can calculate the rom table layer thickness is d=v * T.
Use above-mentioned kind mode, also can be used for calculating the distance between each data Layer and surface in the multilayer optical disc.See also Fig. 6 B, it is the signal schematic representation of multilayer optical disc.With four layers of laser disc is example, when lens rise, can know that by beam intensity signal BS and focus error signal FE the focus of laser beam passes through the surface of laser disc, first data Layer, second data Layer, the 3rd data Layer, the 4th data Layer in regular turn.Therefore; Can obtain focus is Tc through the time between the surface and first data Layer; Focus is Td1 through the time between first data Layer and second data Layer; Focus is Td2 through the time between second data Layer and the 3rd data Layer, and focus is Td3 through the time between the 3rd data Layer and the 4th data Layer.Certainly, if multilayer optical disc also has the more data layer, also can obtain the time between more different layers.
Arbitrary S curve produces the required time T s of two peak values among the focus error signal FE because CD-ROM drive also can be measured.Therefore, can calculate the distance between arbitrary data Layer and the surface, for instance, by the slope of focus motor output signal FMO derive the speed that lens move (v), and obtain between the 3rd data Layer and the surface apart from d '=v * (Tc+Td1+Td2)
See also Fig. 7, it is for the sa compensation means of CD-ROM drive of the present invention.This device comprises: digital signal processor (DSP) 700, spherical-aberration compensator 710, focus motor actuator 720, stride rail motor actuator 730, optical read/write head 740, light measurement signal generator 750 and memory storage 760.Wherein, also comprise in the digital signal processor 700: arithmetic element 702, control module 704, reflectogauge 706.
When start-up routine, control module 704 can utilize strides rail motor actuator 730 and moves radially optical pickup to the first radial location r1, and output focus motor output signal FMO moves to the lens of focus motor actuator 720 with 740 li of control optical read/write heads.At this moment, light measurement signal generator 750 can be according to the various signals of light signal generating that receive, for example focus error signal FE, light intensity signal BS, stride rail error signal (TE) or the like.And reflectogauge 706 is the skin depth d1 of the exportable first radial location r1 position.
In like manner, control module 704 can utilize once more and stride rail motor actuator 730 mobile optical pickup to the second radial location r2 radially, and output focus motor output signal FMO moves to the lens of focus motor actuator 720 with 740 li of control optical read/write heads.And light measurement signal generator 750 can be according to the various signals of light signal generating that receive, for example focus error signal FE, light intensity signal BS, stride rail error signal or the like.And reflectogauge 706 is the skin depth d2 of the exportable second radial location r2 position.Wherein, the first radial location r1 can be the inner ring position of laser disc, and the second radial location r2 can be the position, outer ring of laser disc.
And arithmetic element can calculate the relation of skin depth and radius according to the skin depth d1 of the first radial location r1 and the skin depth d2 of the second radial location r2.Then, control module 704 can carry out the spherical aberration compensation corrective action and obtain best spherical aberration compensation value c0 at the 3rd radial location r3.And arithmetic element 702 promptly calculates the relation between radial location and the spherical aberration compensation value according to the spherical aberration compensation value c0 that the 3rd radial location r3 place obtains.
Therefore, when CD-ROM drive during in normal operation, arithmetic element 702 can obtain the spherical aberration compensation value and also be passed to spherical-aberration compensator 710 according to any radial location at optical read/write head 740 places, realizes reducing the purpose of spherical aberration.
Moreover the spherical aberration compensation corrective action has a variety of modes.For example, best spherical aberration compensation value c0 is proofreaied and correct and obtained to available servosignal (for example focus error signal FE, stride the rail error signal) before carrying out lock rail (trackon) action as yet.Perhaps, after the lock rail, utilize the error rate (data error rate) that reads data on the track to proofread and correct and obtain the spherical aberration compensation value.Perhaps, directly the manufacturer of spherical-aberration compensator 710 is advised that the best spherical aberration compensation value c0 during with standard thickness is stored in the memory storage 760 in advance, the best spherical aberration compensation value c0 in the direct read storage device 760 of timing gets final product.Perhaps, when CD-ROM drive reads the laser disc data after start-up routine, also can dynamically carry out the spherical aberration compensation corrective action.
Certainly, because spherical aberration compensation corrective action mode is a lot, the present invention is applicable to any spherical aberration compensation corrective action and obtain best spherical aberration compensation value c0, can carry out follow-up spherical aberration compensation action.
See also Fig. 8, it is the process flow diagram of spherical aberration compensating method of the CD-ROM drive of first embodiment of the invention.When the beginning start-up routine, measure laser disc top layer first thickness d 1 (step 810) of the first radial location r1; Then, measure laser disc top layer second thickness d 2 (step 820) of the second radial location r2; Carry out the spherical aberration compensation corrective action and obtain best spherical aberration compensation value c0 (step 830) in the 3rd radial location r3; Then, the best spherical aberration compensation value c0 according to the first radial location r1, first thickness d 1, the second radial location r2, second thickness d 2, the 3rd radial location r3 obtains spherical aberration compensation function (step 840); At last, according to place the 4th radial location r4 of optical read/write head, the renewal spherical aberration compensation value of utilizing the spherical aberration compensation function to calculate exports spherical-aberration compensator (step 850) to.
First embodiment by above-mentioned can know that the first radial location r1 is in the laser disc inner circle area, and second radial location r2 collar region outside laser disc, the 3rd radial location r3 then have no restriction also can be same as the first radial location r1 or the second radial location r2.Moreover, the spherical aberration compensation corrective action of step 830, can be above-mentioned multiple mode one of them.Moreover; In step 840, can obtain the spherical aberration compensation function is: c=c0+K* Δ d; Wherein, c0 is the best spherical aberration compensation value of the 3rd radial location r3, Δ d be laser disc the 4th radial location r4 and and laser disc the 3rd radial location r3 between amounts of thickness variation; K is a penalty constant, and c is the offset that calculates.
See also Fig. 9, it is the process flow diagram of spherical aberration compensating method of the CD-ROM drive of second embodiment of the invention.When the beginning start-up routine, measure laser disc top layer first thickness d 1 (step 910) of the first radial location r1; Then, measure laser disc top layer second thickness d 2 (step 920) of the second radial location r2; After calculating the thickness distribution on laser disc top layer, can calculate the change trend (step 930) of spherical aberration compensation value; Then, read the data of laser disc, and, utilize trial and error, produce and upgrade spherical aberration compensation value (step 940) according to the change trend of data error rate and spherical aberration compensation value; At last, will upgrade the spherical aberration compensation value and export spherical-aberration compensator (step 950) to.
Second embodiment by above-mentioned can know that the first radial location r1 is in the laser disc inner circle area, and second radial location r2 collar region outside laser disc, the 3rd radial location r3 then have no restriction also can be same as the first radial location r1 or the second radial location r2.Moreover, can determine according to this distribution of laser disc thickness to have following three types in step 930, (a) by inner ring to the outer ring thickening progressively, (b) by inner ring progressively attenuation to the outer ring, (c) by inner ring to the outer ring difference in thickness little.After decision laser disc thickness distribution, can determine the spherical aberration compensation direction.Therefore, when CD-ROM drive when arbitrarily radial location is reading the data on the laser disc, promptly dynamically change the spherical aberration compensation value immediately, and revise the problem that spherical aberration produces according to the error rate of data.So, because know the change trend of spherical aberration compensation value in advance, between the examination in the time of can shortening the spherical aberration compensation action is mistaken.
Certainly, also can apply the present invention to the spherical aberration compensation of multilayer optical disc the technician in this field.As long as CD-ROM drive obtains the distance relation between each layer in different radial location; Collocation spherical aberration compensation corrective action once promptly obtains the spherical aberration compensation function on arbitrary data Layer; And can carry out the compensating movement of spherical aberration to arbitrary data Layer, therefore repeat no more.
The above only is preferred embodiment of the present invention, is not the present invention is done any pro forma restriction; Though the present invention discloses as above with preferred embodiment; Yet be not that any those skilled in the art are not in breaking away from technical scheme scope of the present invention in order to qualification the present invention; When the technology contents of above-mentioned announcement capable of using is made a little change or is modified to the equivalent embodiment of equivalent variations; In every case be not break away from technical scheme content of the present invention, to any simple modification, equivalent variations and modification that above embodiment did, all still belong in the scope of technical scheme of the present invention according to technical spirit of the present invention.
Claims (10)
1. the spherical aberration compensating method of a CD-ROM drive comprises the following steps:
Measure first skin depth of first radial position of a laser disc;
Measure second skin depth of second radial position of said laser disc;
Carry out the spherical aberration compensation corrective action and obtain best spherical aberration compensation value in the 3rd radial location of said laser disc;
According to the said best spherical aberration compensation value of said first radial location, said second radial location, said first skin depth, said second skin depth, said the 3rd radial location, obtain the spherical aberration compensation function; And
The 4th radial location and said spherical aberration compensation function calculation according to an optical read/write head place go out a renewal spherical aberration compensation value, and import a spherical-aberration compensator of said CD-ROM drive.
2. the spherical aberration compensating method of CD-ROM drive as claimed in claim 1; It is characterized in that said spherical aberration compensation function is c=c0+K* Δ d, wherein; C0 is best spherical aberration compensation value; Δ d is the said amounts of thickness variation in the 4th radial location and said the 3rd radial position of said laser disc, and K is a penalty constant, and c is the said renewal spherical aberration compensation value that calculates.
3. the spherical aberration compensating method of CD-ROM drive as claimed in claim 1; It is characterized in that; Said spherical aberration compensation corrective action is included in said CD-ROM drive and does not carry out as yet before the action of lock rail, utilizes a plurality of servosignals of said optical read/write head output to obtain said best spherical aberration compensation value.
4. the spherical aberration compensating method of CD-ROM drive as claimed in claim 1; It is characterized in that; After said spherical aberration compensation corrective action comprises that said CD-ROM drive is carried out the action of lock rail, utilize the error rate of reading of data, proofread and correct and obtain said best spherical aberration compensation value with trial and error.
5. the spherical aberration compensating method of CD-ROM drive as claimed in claim 1; It is characterized in that said spherical aberration compensation corrective action comprises according to the best spherical aberration compensation value of said spherical-aberration compensator when the standard thickness proofreaies and correct and obtain said renewal spherical aberration compensation value.
6. the spherical aberration compensating method of a CD-ROM drive comprises the following steps:
Measure first skin depth of first radial position of a laser disc;
Measure second skin depth of second radial position of said laser disc;
According to said first radial location, said second radial location, said first thickness, said second thickness, the skin depth that calculates said laser disc distributes, and calculates the change trend of spherical aberration compensation value according to this;
Read the data of said laser disc, and, produce one and upgrade the spherical aberration compensation value according to the change trend of data error rate and said spherical aberration compensation value; And
Said renewal spherical aberration compensation value is imported a spherical-aberration compensator of said CD-ROM drive.
7. the sa compensation means of a CD-ROM drive is connected in an optical read/write head, comprising:
Stride the rail motor actuator for one, be connected to said optical read/write head, to control moving radially of said optical read/write head;
A spherical-aberration compensator;
A focus motor actuator is connected to said optical read/write head, moves with the focus direction of controlling said optical read/write head;
A light measurement signal generator receives the light signal that said optical read/write head produces, and is converted into a plurality of electric signal; And
A digital signal processor is electrically connected to said rail motor actuator, said spherical-aberration compensator, said focus motor actuator and the said light measurement signal generator of striding;
Wherein, Said digital signal processor is used to make said optical read/write head and moves to first radial location and second radial location and corresponding first skin depth and second skin depth of calculating; And carry out the spherical aberration compensation corrective action and obtain a best spherical aberration compensation value in the 3rd radial location; And obtain a spherical aberration compensation function according to this; And utilize said spherical aberration compensation function calculation to go out said renewal spherical aberration compensation value, and import said spherical-aberration compensator according to the 4th radial location at said optical read/write head place.
8. sa compensation means as claimed in claim 7 is characterized in that, said spherical-aberration compensator be as the criterion liner ball difference compensator or liquid crystal spherical-aberration compensator.
9. sa compensation means as claimed in claim 7 is characterized in that, said digital signal processor comprises:
A reflectogauge is electrically connected to said light measurement signal generator, and the electric signal that provides according to said light measurement signal generator calculates said first skin depth and said second skin depth;
An arithmetic element; Be electrically connected to said reflectogauge; Receive said first skin depth of said first radial position and said second skin depth of said second radial position; And the said spherical aberration compensation value that obtains of said the 3rd radial location place of arranging in pairs or groups, obtain the relation of said renewal spherical aberration compensation value and said laser disc radial location according to this; And
A control module is electrically connected to said spherical-aberration compensator, when said the 4th radial location, is controlled by said arithmetic element, exports said renewal spherical aberration compensation value to said spherical-aberration compensator.
10. sa compensation means as claimed in claim 9; It is characterized in that; Also comprise a memory storage that is electrically connected to said arithmetic element, the best spherical aberration compensation value when storing a standard thickness, and carry out said spherical aberration compensation corrective action according to this.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201010517230.7A CN102456361B (en) | 2010-10-19 | 2010-10-19 | Method and device for compensating spherical aberration of compact disc drive |
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| Application Number | Priority Date | Filing Date | Title |
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| CN201010517230.7A CN102456361B (en) | 2010-10-19 | 2010-10-19 | Method and device for compensating spherical aberration of compact disc drive |
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| CN102456361A true CN102456361A (en) | 2012-05-16 |
| CN102456361B CN102456361B (en) | 2014-10-08 |
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Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20020114231A1 (en) * | 2001-02-16 | 2002-08-22 | Nec Corporation | Optical disk device |
| CN101354893A (en) * | 2007-07-24 | 2009-01-28 | 建兴电子科技股份有限公司 | Method for calibrating optimum spherical aberration compensation position standard of CD ROM |
| US7489615B2 (en) * | 2004-08-25 | 2009-02-10 | Konica Minolta Opto, Inc. | Objective optical element, optical pickup apparatus and optical disc driving apparatus |
| TW201001408A (en) * | 2008-06-26 | 2010-01-01 | Sunplus Technology Co Ltd | Optical storage system and spherical aberration compensation apparatus and method thereof |
-
2010
- 2010-10-19 CN CN201010517230.7A patent/CN102456361B/en not_active Expired - Fee Related
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20020114231A1 (en) * | 2001-02-16 | 2002-08-22 | Nec Corporation | Optical disk device |
| US7489615B2 (en) * | 2004-08-25 | 2009-02-10 | Konica Minolta Opto, Inc. | Objective optical element, optical pickup apparatus and optical disc driving apparatus |
| CN101354893A (en) * | 2007-07-24 | 2009-01-28 | 建兴电子科技股份有限公司 | Method for calibrating optimum spherical aberration compensation position standard of CD ROM |
| TW201001408A (en) * | 2008-06-26 | 2010-01-01 | Sunplus Technology Co Ltd | Optical storage system and spherical aberration compensation apparatus and method thereof |
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| CN102456361B (en) | 2014-10-08 |
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