CN1115689C - Automatic regulator and method for optimum focusing point of CD machine - Google Patents
Automatic regulator and method for optimum focusing point of CD machine Download PDFInfo
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- CN1115689C CN1115689C CN98105258A CN98105258A CN1115689C CN 1115689 C CN1115689 C CN 1115689C CN 98105258 A CN98105258 A CN 98105258A CN 98105258 A CN98105258 A CN 98105258A CN 1115689 C CN1115689 C CN 1115689C
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Abstract
The present invention relates to an automatic regulator and a method for optimum focusing points of a CD machine, which comprises RERP circuits, a signal processing device and a standard position offset device, wherein the RERP circuits receive radio frequency signals and output an RFRP signal; the signal processing device is coupled with the RFRP circuits to measure the magnitude of the RFRP signal; the standard position offset device is coupled with the signal processing device, calculates adjacent second focusing bias points and orderly transmits the maximum positions of the second focusing bias points corresponding to the RFRP signal found by the signal processing device according to the first focusing bias points and an offset bias quantity, and judges whether the bias quantity can be divided or not; when the offset bias quantity can be divided, the second focusing bias points replace the first bias points.
Description
The invention relates to a kind of optical head of CD player, and particularly relevant for a kind of method of using tree-shaped search, so that fast searching is to the automatic regulating apparatus and the method for the best focal point of CD player.
Because improving constantly of Information of Science and Technology, traditional magnetic disk machine (Disk) is limited because of its development space, adds that its storage volume is little, so the existing trend that is replaced by CD player (Optical Disk Drive) gradually of disk drive.Because CD player has advantages such as high power capacity, can store great mass of data simultaneously, adds the generation of a read-write CD, make CD player be used widely by popular institute.
Yet CD player is when volume production, and its assembly comprises motor, transport element etc., can not reach without the slightest difference stage, with and electronic component for example resistance, electric capacity etc., also all can be with changing its characteristic service time.On the other hand, the environment temperature the when user operates also can impact the electronic component of CD player.Add the optical characteristics and the reflectivity difference of discs own of optical sensor (Photo Sensor), also need do suitable adjustment, just be unlikely focusing on wrong generation.
Usually, in the application of CD player, the producing method of signal is to utilize laser diode (Laser Diode) the emission laser of optical head part (PickupHead), and this laser beam can produce focus point (Focusing Point) back reflection and return at optical head optical sensor partly on discs.Again, optical sensor can be divided into the two large divisions, and a part of quadrisection is in order to produce focus error signal (Focusing Error; FE), another part is divided into bisection, follows rail rub-out signal (Tracking Error in order to generation; TE), this two large divisions can produce six current signals corresponding to light intensity after receiving laser respectively, these six signals are behind current-voltage converter and prime amplifier (Pre-Amplifier), then produce our needed signal in the application of CD player, for example focus error signal (FE), follow rail rub-out signal (TE) and radiofrequency signal (RF signal) etc.
Learn in the application flow by above-mentioned CD player that the quality of laser focusing can directly influence the quality of signal, in addition, the induction degree of different each parts of optical sensor is all incomplete same, therefore can cause the imbalance of signal, and then the result of influence control.
Please refer to Fig. 1, Fig. 1 is the graph of a relation of focus offset (Focus Bias) and radiofrequency signal.When focusing on best position (a point), radiofrequency signal be a maximum, when the reflectivity of optical sensor differs or the enlargement factor of prime amplifier when different, will cause the imbalance (unbalance) of focus error signal, shown in Fig. 2 B.And Fig. 2 A is the figure of focus error signal when being balance (unbalance).
Certainly, we wish that the position that focuses on can maintain on a point as Fig. 1.For example, prior art method comprises two kinds of methods of adjusting focus point at least: one is to use the method for adjusting manually, and Using such method is used when volume production, certainly will expend a large amount of times of adjusting manually, do not meet very much economic benefit, more can cause the increase of cost.
Another kind of prior art method is exposed in
HayashiIn " focusing on balance automatic regulating apparatus and automatic adjusting method " literary composition Deng people's U.S. Patent number 5,610,886.
According to this known method, if the signal of Fig. 2 B (uvballance) is during for the input of our controller, will cause optical head to be controlled in the position of mistake (error), the b of Fig. 1 point for example, and this moment wrong position (b point) and correct position (a point) between will have a side-play amount (Bias).According to this known method, at first, be the center, and respectively define a focus bias point in its both sides with the b point.Then, the RFRP signal magnitude of this 2 focus bias point and tram (a point) relatively, the focus bias point of getting the RFRP signal difference minimum after the comparison then is as the central point that focuses on search next time.Repeat above-mentioned steps, till the optical head of CD player is controlled in tram (a point).
But if at the beginning the time, the side-play amount of input signal and tram is very big, for example when c point position, must expend a large amount of shift times this moment, just can be adjusted to correct position.
Learn that by above-mentioned prior art method prior art method comprises following shortcoming:
(1) use when the volume production with the method for adjusting manually, heat must expend a large amount of times of adjusting manually, does not meet very much economic benefit, more can cause the increase of cost.
(2) according to the self-adjusting method of focus point of the CD player that the people proposed such as Hayashi, though comparatively quicker than adjusting manually, when input signal and tram differ greatly, also need expend a large amount of shift times, could adjust the tram.
Therefore, purpose of the present invention just provides the self-adjusting method of a kind of CD player best focal point, the time of adjusting manually during with the shortening volume production.
According to another object of the present invention, provide a kind of CD player best focal point self-adjusting method, it is to use the method for tree-shaped search, searches purpose fast to reach, and is to realize with digital form, has and adjusts easily and cost-effective function.
According to a further object of the present invention, provide a kind of to adjust the zero crossover point (reference mark) of focus error signal, make the optical head of CD player partly be controlled at the CD player best focal point automatic regulating apparatus and the method at best focal point place.
For reaching above-mentioned and other purposes of the present invention, CD player best focal point automatic regulating apparatus provided by the present invention and method are to use the method for tree-shaped search, so can finish the automatic adjustment action of CD player best focal point in the shortest time.And when the present invention can start in system, immediately the non-equilibrium state of focus error signal is done self-adjusting action at every turn, system can be maintained under the optimum of original design.Again, the present invention realizes with digital form, adjusts easily and cost-effective function so have.
A kind of CD player best focal point automatic regulating apparatus provided by the invention, this CD player has an optical head, this optical head is in order to read the data on the discs, this CD player best focal point automatic regulating apparatus comprises: a RFRP circuit, in order to receive the input of a radiofrequency signal, and comply with this radiofrequency signal and export a RFRP signal, wherein this RFRP signal is the signal for corresponding one first focusing bias point; One signal processor couples this RFRP circuit, in order to measure the size of this RFRP signal; And position deviator surely, couple this signal processor, in order to first to focus on a bias point and a skew bias amount, calculate adjacent a plurality of second and focus on bias point according to this; Wherein should send those adjacent second focusing bias point in regular turn by standard position deviator, and find out this second position that focuses on bias point of corresponding maximum this RFRP signal by this signal processor, and judge whether this skew bias amount can be cut apart, if this skew bias amount can be cut apart again, then this second focusing bias point with corresponding maximum this RFRP signal replaces this first focusing bias point, and cuts apart this skew bias amount; And this first initial position that focuses on bias point is the initial focus position of this CD player.
The self-adjusting method of a kind of CD player best focal point provided by the invention comprises the following steps: that a. provides one first to focus on bias point and one first skew bias amount; B. according to this first focusing bias point and this first skew bias amount, calculate adjacent a plurality of second focusing bias point; C. send those adjacent second focusing bias point in regular turn, those each corresponding different RFRP signals of second focusing bias point are measured the size of each those RFRP signal, and find out the position of this second focusing bias point of corresponding this RFRP signal of maximum; D. judge whether this first skew bias amount can be cut apart, if this first skew bias amount can be cut apart again, then this second focusing bias point with corresponding maximum this RFRP signal replaces this first focusing bias point, replace this first skew bias amount with one second skew bias amount, and repeating step b is to steps d; And e. then finishes the best focal point of this CD player and adjusts action automatically if this first skew bias amount can't be cut apart again, and this of corresponding maximum this RFRP signal second focuses on bias point and be this CD player best focal point; Wherein this first initial position that focuses on bias point is the initial focus position of this CD player.
For above-mentioned and other purposes of the present invention, feature and advantage can be become apparent, a preferred embodiment cited below particularly, and conjunction with figs. are described in detail below:
Brief Description Of Drawings:
Fig. 1 is the graph of a relation of focus offset and radiofrequency signal;
Fig. 2 A is the figure of focus error signal when being balance;
Fig. 2 B is the figure of focus error signal when being imbalance;
Fig. 3 is the function block diagram according to the light focus point of the adjustment CD player of a preferred embodiment of the present invention;
Fig. 4 is the tree-shaped search figure according to the light focus point of a preferred embodiment of the present invention; And
Fig. 5 is the adjustment process flow diagram according to the light focus point of the CD player of a preferred embodiment of the present invention;
Embodiment
Please refer to Fig. 3, shown in it is function block diagram according to the adjustment light focus point of a kind of CD player of a preferred embodiment of the present invention.
After the optical sensor 5 of optical head part receives the discs laser light reflected, produce A, B, four signals of C, D.Then, produce a focus error signal (FE), and produce a radiofrequency signal (RF) via amplifier 11 via amplifier 10.Wherein, focus error signal is (A+C)-(B+D), and radiofrequency signal is A+B+C+D.
Then, RFRP circuit 12 can become binary signal with bottom (bottom) acquisition with the honeybee end (peak) of radiofrequency signal (RF), this binary signal is respectively taken advantage of to subtract each other after the gain (Gain) again to produce the RFRP signal.
Please suppose the initial focus position of focus point 19, that is focus point 19 be present focus point simultaneously with reference to Fig. 3 and Fig. 4 for the optical head of CD player.At first, accurate position deviator (Level Bias) 14 can be the center with present focus point 19, and finds out the offset numbers n and the side-play amount K that can search best focal point in the shortest time.Then, accurate position deviator 14 can produce n adjacent focusing bias point in regular turn according to offset numbers n and side-play amount K, suppose that n equals five, this moment, the space size (side-play amount) of these five adjacent focusing bias point was K, and these five adjacent focusing bias point all respectively have a different RFRP signal.
Then, signal processor (Signal Processing) 13 can calculate the size of each RFRP signal of these five adjacent focusing bias point respectively, and find out focusing bias point position with maximum RFRP signal, for example focus on bias point 20 for having the focusing bias point position of maximum RFRP signal, and then to focus on the central point that bias point 20 is optical head focusing, repeat above-mentioned seek actions, till side-play amount can't be cut apart, represent that promptly optical head has found the best focal point position.
On the other hand, controller (Controller) 15 receives one and focuses on wrong shifted signal (FE-Offset), wherein FE-Offset is in order to be adjusted to a reference potential with accurate position, center (as accurate position, the center among Fig. 2 B Vref), and accurate position, above-mentioned center Vref is direct current (DC) part of focus error signal (FE).
Therefore, when not having the input of side-play amount (Bias), learn in closed loop (Closed loop) theory by controller, this moment controller 15 can to control to focus error signal be till zero, that is can be with the position control of optical head at zero crossover point (Zero Crossing Point).But when control signal was shown in Fig. 2 B, controller 15 can be with the position control of optical head on zero crossover point of mistake, that is at the accurate Vref in the center of Fig. 2 B.
Please more simultaneously with reference to Fig. 1 and Fig. 2 B.If we wish the position of optical head is moved to a point by the b point, that is be to make our zero crossover point move to focusing optimum position (dotted line) by accurate the Vref (solid line) in the center of Fig. 2 B, this moment, we must add a side-play amount made the zero crossover point (the accurate position of mid point Vref) of this mistake move to the position (focusing optimum position) that we want in order to achieve the above object.
Therefore, the invention provides a kind of self-adjusting method of focus point of CD player, is to utilize the method for tree-shaped search (Tree Search) to look for out best focal point.Please be simultaneously with reference to Fig. 4 and Fig. 5, Fig. 5 is the method for adjustment process flow diagram according to the light focus point of the CD player of a preferred embodiment of the present invention.
At first, step 31: an initial focus bias point 19 and a skew bias amount K are provided, wherein initial focus bias point 19 that is the focal position of optical head at present, the size of skew bias amount K is to be as the criterion searching best focal point in the shortest time.
Step 32: then, focusing on bias point 19 with this is central point, and sends n adjacent focusing bias point successively according to side-play amount K, supposes that n equals five, and this moment, the space size (side-play amount) of these five adjacent focusing bias point was K.Because the side-play amount of being sent all has nothing in common with each other, thereby can change the position of focusing, and then causes the big or small different of RFRP signal.
Step 33: afterwards, measure the size of the RFRP signal of these adjacent five focus points respectively, find out the side-play amount that causes the RFRP signal maximum then, that is with focusing bias point with the maximum RFRP signal focus point as tree-shaped search next time, for example focus point 20.
Step 34: then, judge whether side-play amount K can be cut apart.If side-play amount K can be cut apart again, then carry out step 35, otherwise,, then finish focus point adjustment work, as step 36.
Step 35: if side-play amount K can be cut apart again, adjust K value this moment and be original 1/4th, be that side-play amount is changed into K/4, and be new focusing center's point with focus point 20, repeating step 32～34 then, can't cut apart up to side-play amount K (Bias), that is side-play amount K are minimum, the RFRP signal is maximum, promptly is our required best focal point position.
Certainly, method of the present invention is not limited to once can only produce five focus points (side-play amount) and searches, for example once can produce 2 side-play amounts, 3 side-play amounts ..., or 7 side-play amounts wait the search of carrying out best focal point.For example, when once producing 3 side-play amounts, this moment, its mutual gap size was previous 1/2nd, and when once producing n side-play amount, its mutual gap size is previous (n-1)/one at this moment.Certainly, producing the setting of side-play amount quantity, is to be principle can find best focal point in the shortest time.
On the other hand, the present invention is when system start-up, no matter whether the optical head of CD player has been in best focus position, the self-adjusting action of focus point all can be done by system, to avoid the result of unbalanced effect of signals to control.
Therefore, CD player best focal point automatic regulating apparatus provided by the present invention and method have following several advantages:
(1) the present invention is to use the method for tree-shaped search, is used in the automatic adjustment of focus point of CD player, so can finish the automatic adjustment action of the best focal point of CD player in the shortest time, has improved known time-consuming shortcoming widely.
When (2) the present invention can start in system, promptly the non-equilibrium state of focus error signal is done self-adjusting action at every turn, system can be maintained under the optimum of original design.
(3) the present invention realizes with digital form, adjusts easily and cost-effective function so have.
In sum; though the present invention discloses as above with preferred embodiment; right its is not in order to limit the present invention; anyly have the knack of this skill person; without departing from the spirit and scope of the present invention; when can being used for a variety of modifications and variations, so protection scope of the present invention is as the criterion by the claim person of defining of the present invention.
Claims (5)
1. CD player best focal point automatic regulating apparatus, this CD player has an optical head, and this optical head is in order to read the data on the discs, and this CD player best focal point automatic regulating apparatus comprises:
One RFRP circuit, in order to receive the input of a radiofrequency signal, and comply with this radiofrequency signal and export a RFRP signal, wherein this RFRP signal is the signal for corresponding one first focusing bias point, this first initial position that focuses on bias point is the initial focus position of this CD player;
One signal processor couples this RFRP circuit, in order to measure the size of this RFRP signal; And
Surely the position deviator couples this signal processor, in order to according to this first a focusing bias point and a skew bias amount, calculates adjacent a plurality of second focusing bias point;
Wherein should send those adjacent second focusing bias point in regular turn by standard position deviator, and find out this second position that focuses on bias point of corresponding maximum this RFRP signal by this signal processor, and judge whether this skew bias amount can be cut apart, if this skew bias amount can be cut apart again, then this second focusing bias point with corresponding maximum this RFRP signal replaces this first focusing bias point, and cuts apart this skew bias amount.
2. device as claimed in claim 1, wherein, this device more comprises:
One first amplifier in order to receiving the data that this optical head reads from this discs, and produces a focus error signal;
One second amplifier in order to receiving the data that this optical head reads from this discs, and produces one and follows the rail rub-out signal; And
One controller, in order to the position control of this optical head on one zero crossover points.
3. device as claimed in claim 2, wherein, this optics comprises first watch:
One laser diode is in order to launch a laser beam to this discs; And
One optical sensor is in order to receive this laser beam of reflection.
4. the self-adjusting method of CD player best focal point comprises the following steps:
A. provide one first to focus on bias point and one first skew bias amount, this first initial position that focuses on bias point is the initial focus position of this CD player;
B. according to this first focusing bias point and this first skew bias amount, calculate adjacent a plurality of second focusing bias point;
C. send those adjacent second focusing bias point in regular turn, those each corresponding different RFRP signals of second focusing bias point are measured the size of each those RFRP signal, and find out the position of this second focusing bias point of corresponding this RFRP signal of maximum;
D. judge whether this first skew bias amount can be cut apart, if this first skew bias amount can be cut apart again, then this second focusing bias point with corresponding maximum this RFRP signal replaces this first focusing bias point, replace this first skew bias amount with one second skew bias amount, and repeating step b is to steps d; And
E. if this first skew bias amount can't be cut apart again, then finish the best focal point of this CD player and adjust action automatically, this second focusing bias point of corresponding maximum this RFRP signal is this CD player best focal point.
5. method as claimed in claim 4, wherein, those second quantity that focus on bias point represent that with n this first skew bias amount is represented with K1, this second skew bias amount represents that with K2 then the mutual relationship of this first skew bias amount and this second skew bias amount is K2=K1/ (n-1).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN98105258A CN1115689C (en) | 1998-02-26 | 1998-02-26 | Automatic regulator and method for optimum focusing point of CD machine |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN98105258A CN1115689C (en) | 1998-02-26 | 1998-02-26 | Automatic regulator and method for optimum focusing point of CD machine |
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| CN1227384A CN1227384A (en) | 1999-09-01 |
| CN1115689C true CN1115689C (en) | 2003-07-23 |
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| CN98105258A Expired - Lifetime CN1115689C (en) | 1998-02-26 | 1998-02-26 | Automatic regulator and method for optimum focusing point of CD machine |
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Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1300777C (en) * | 2003-10-17 | 2007-02-14 | 上海乐金广电电子有限公司 | Interference removing apparatus and method for focusing error signal and tracking error signal |
| JP4676240B2 (en) * | 2005-04-25 | 2011-04-27 | 株式会社日立製作所 | Optical disc apparatus, focus offset and recording power adjustment method for optical disc apparatus, and focus offset and recording power adjustment program for optical disc apparatus |
| CN101335022B (en) * | 2007-06-26 | 2011-01-05 | 宏阳科技股份有限公司 | Correcting method for CD ROM focus loop changing |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5065386A (en) * | 1989-04-05 | 1991-11-12 | Pioneer Electronic Corporation | Servo system responsive to noise and having variable characteristic filter means |
| US5109367A (en) * | 1989-09-21 | 1992-04-28 | Olympus Optical Co., Ltd. | Optical information recording and reproducing apparatus performing focus and/or track control by normalized error signals |
| US5363357A (en) * | 1991-10-16 | 1994-11-08 | Mitsubishi Denki Kabushiki Kaisha | Focus control system |
| US5610886A (en) * | 1993-02-15 | 1997-03-11 | Kabushiki Kaisha Toshiba | Focus balance automatic adjusting device and automatic adjusting method |
-
1998
- 1998-02-26 CN CN98105258A patent/CN1115689C/en not_active Expired - Lifetime
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5065386A (en) * | 1989-04-05 | 1991-11-12 | Pioneer Electronic Corporation | Servo system responsive to noise and having variable characteristic filter means |
| US5109367A (en) * | 1989-09-21 | 1992-04-28 | Olympus Optical Co., Ltd. | Optical information recording and reproducing apparatus performing focus and/or track control by normalized error signals |
| US5363357A (en) * | 1991-10-16 | 1994-11-08 | Mitsubishi Denki Kabushiki Kaisha | Focus control system |
| US5610886A (en) * | 1993-02-15 | 1997-03-11 | Kabushiki Kaisha Toshiba | Focus balance automatic adjusting device and automatic adjusting method |
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| CN1227384A (en) | 1999-09-01 |
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