CN101813818B - Circuit used for correcting focusing position of optical module and correction method thereof - Google Patents
Circuit used for correcting focusing position of optical module and correction method thereof Download PDFInfo
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- CN101813818B CN101813818B CN200910008315XA CN200910008315A CN101813818B CN 101813818 B CN101813818 B CN 101813818B CN 200910008315X A CN200910008315X A CN 200910008315XA CN 200910008315 A CN200910008315 A CN 200910008315A CN 101813818 B CN101813818 B CN 101813818B
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- focal position
- focus
- signal
- optical module
- correction
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Abstract
The method provides a circuit used for correcting a focusing position of an optical module and a correction method thereof. The circuit comprises a correction signal generation unit and a focusing position adjustment unit, wherein the correction signal generation unit is used for generating a correction signal according to at least a first focusing signal which corresponds to a first focusing position and a second focusing signal which corresponds to a second focusing position at the same time; the first focusing position is different from the second focusing position; and the focusing position adjustment unit is coupled to the correction signal generation unit and is used for adjusting the focusing position of the optical module to a specific focusing position according to the correction signal. Due to the adoption of the circuit used for correcting the focusing position of the optical module and the correction method thereof, a correct optimum focusing position can be obtained by eliminating the influence of noises, so that the quality of shot pictures or images is improved.
Description
Technical field
The present invention relates to the correction of the focal position of optical module, relate in particular to a kind of circuit and bearing calibration thereof that utilizes the focal position that the phase-locked loop comes the calibrating optical module.
Background technology
General camera model is being focused automatically; Also promptly when its focal position of NMO correction (focusposition); (Focus Value is FV) to obtain a focal position and the focus value table of comparisons or the characteristic curve of a focal position and focus value for the focus value of each focal position of detection earlier.Please refer to Fig. 1, Fig. 1 obtains the synoptic diagram of best focus position for the characteristic curve of focal position and focus value and the utilization search method (mountain-climbing search method) of climbing the mountain.In Fig. 1; Solid line 110 is the characteristic curve of focal position and focus value; The focal position that wherein corresponds to maximum focus value is best focus position (that is to say the peak value (peak value) of characteristic curve 110); Dotted line then is used for representing to utilize the climb the mountain moving direction of search method focal position when seeking best focus position and mobile step size; The search method of climbing the mountain is the method that general camera model is used always when focusing, and those of ordinary skills all should be appreciated that the principle of operation and the correlative detail of the method, therefore repeats no more at this.
Yet, climb the mountain before search method seeks best focus position in utilization, need obtain the characteristic curve 110 of focal position and focus value earlier; In theory, characteristic curve 110 is illustrated in figure 1 as the curve of a symmetry, and a peak value is only arranged; Yet; Because The noise, the detected characteristic curve of camera model can not be to be the curve of a symmetry shown in Fig. 2 (a), even can shown in Fig. 2 (b), have the peak value more than 2 or 2; Thus; The best focus position that search method searched of climbing the mountain possibly not be actual best focus position, thereby causes camera model to take a picture or to photograph with the focal position of the best, and has influence on the quality of captured photo or image.
Summary of the invention
Therefore, one of the object of the invention is to provide a kind of circuit and bearing calibration thereof that utilizes the focal position that the phase-locked loop comes the calibrating optical module, to solve the above problems.
According to one embodiment of the invention, a kind of circuit in order to the focal position of proofreading and correct an optical module includes a correction signal generation unit and a focal position adjustment unit.According to producing a correction signal corresponding to one first focus signal of one first focal position and corresponding to one second focus signal of one second focal position at least, wherein this first focal position differs from this second focal position to this correction signal generation unit in order to simultaneously.This focal position adjustment unit is coupled to this correction signal generation unit, and is used for being adjusted to a specific focal position according to this correction signal with the focal position with this optical module.
According to another embodiment of the present invention; A kind of method in order to the focal position of proofreading and correct an optical module includes: according to producing a correction signal corresponding to one first focus signal of one first focal position and corresponding to one second focus signal of one second focal position at least, wherein this first focal position differs from this second focal position simultaneously; And be adjusted to a specific focal position with focal position with this optical module according to this correction signal.
Circuit and method according to the focal position in order to the calibrating optical module of the present invention; Even the characteristic curve of detected focal position and focus value has as shown in Figure 2 because of The noise; Circuit of the present invention and method also can be eliminated these The noise and obtain correct best focus position, and then improve the quality of captured photo or image.
Description of drawings
Fig. 1 obtains the synoptic diagram of best focus position for the characteristic curve of focal position and focus value and the utilization search method of climbing the mountain.
Fig. 2 is the synoptic diagram of characteristic curve that receives focal position and the focus value of noise effect.
Fig. 3 is the synoptic diagram of one embodiment of the invention in order to the circuit of the focal position of calibrating optical module.
Fig. 4 is the sequential chart of the focal position of circuit calibrating optical module shown in Figure 3.
Fig. 5 is the synoptic diagram of the characteristic curve of the detected focal position of optical module and focus value in each correction time shown in Figure 4.
Wherein, description of reference numerals is following:
110,510 characteristic curvees
300 circuit
310 focus signal generation units
320 correction signal generation units
322 comparers
324 wave filters
326 integrators
330 focal position correcting units
340 totalizers
Embodiment
Please refer to Fig. 3, Fig. 3 is the synoptic diagram of one embodiment of the invention in order to the circuit 300 of the focal position of calibrating optical module.As shown in Figure 3; Circuit 300 includes a focus signal generation unit 310, a correction signal generation unit 320, a focal position adjustment unit 330 and a totalizer 340, and wherein correction signal generation unit 320 includes a comparer 322, a wave filter 324 and an integrator 326.In addition, the optical module that circuit 300 of the present invention is applied to can be used for the camera model of taking a picture or photographing for one, or other need carry out the optical module that focal position is proofreaied and correct.
The operation of relevant circuit 300; Please be simultaneously with reference to figure 3 to Fig. 5; Wherein Fig. 4 is the sequential chart of the focal position of circuit 300 calibrating optical modules, and Fig. 5 is the synoptic diagram of the characteristic curve 510 of the detected focal position of optical module and focus value when each correction time shown in Figure 4.Be noted that what Fig. 5 drew is a characteristic curve diagram, yet in practical operation, this characteristic curve diagram also can be a focal position and the focus value table of comparisons.Using before circuit 300 of the present invention comes the focal position of calibrating optical module, optical module can use like prior art described climb the mountain search method or other bearing calibrations to find a predetermined focal position K
0, certainly, the characteristic curve of focal position and focus value can not be to be the curve of a symmetry because of The noise, therefore predetermined focal position K
0Possibly not be to be best focal position yet, therefore predetermined focal position K
0Can be considered the result of a coarse adjustment (coarse tune).In addition, predetermined focal position K
0Also can be the mean value that utilizes a plurality of coarse adjustment results that climb the mountain search method or other bearing calibrations find, for example, utilize the search method of climbing the mountain to seek out 10 coarse adjustment results earlier, the mean value that calculates these 10 coarse adjustment results again is with as predetermined focal position K
0
Be noted that " focus value " of the present invention can be the brightness value in the FX, image border intensity level or other correlations.
At the predetermined focal position K of decision
0Afterwards, the predetermined focal position K of focus signal generation unit 310 foundation in the 1st correction time shown in Figure 4
0To determine one first focal position a and one second focal position b, the wherein first focal position a and predetermined focal position K
0Distance, delta equal the second focal position b and predetermined focal position K
0Distance, delta, distance, delta can freely be set according to deviser's consideration, for example distance, delta can be set at and can adjust 25% of focusing distance.After determining the first focal position a and one second focal position b; Focus signal generation unit 310 obtains the one second focus value f (b) that corresponds to the one first focus value f (a) of the first focal position a and correspond to the second focal position b according to characteristic curve 510 shown in Figure 5 or a focal position and the focus value table of comparisons, and respectively the foundation first focus value f (a) and the second focus value f (b) to produce one first focus signal V
aAnd one second focus signal V
b
Afterwards, comparer 322 compares the first focus signal V
aAnd the second focus signal V
bTo produce a comparison signal V
c, wave filter 324 is then to comparing signal V
cCarry out filtering operation to produce comparison signal V after the filtering
LP, afterwards, integrator 326 is according to comparison signal V after the filtering
LPTo produce a correction signal V
e, correction signal V wherein
eCan be regarded as the adjustment amount of a focal position, last, focal position adjustment unit 330 is according to correction signal V
eTo begin that the focal position of optical module (also promptly is scheduled to focal position K by present focal position
0) be adjusted to a specific focal position.Be noted that correction signal V
eCan reflect the first focus signal V
aAnd the second focus signal V
bResidual quantity (also being the residual quantity of the first focus value f (a) and the second focus value f (b)), and focal position adjustment unit 330 can be with the focal position of optical module by predetermined focal position K
0The direction of the pairing focal position of peak value of past characteristic curve 510 moves.With Fig. 5 is example, and in theory, characteristic curve 510 is a symmetrical curve and has only a peak value, if predetermined focal position K
0Be best focus position; Then this best focus position peak value and first focus value f (a) of corresponding to characteristic curve 510 should be identical with the value of the second focus value f (b); Yet in Fig. 5; Therefore the first focus value f (a) can judge that less than the second focus value f (b) the optimum focusing value is to be positioned at predetermined focal position K
0The right side, therefore, focal position adjustment unit 330 is according to correction signal V
eWith the focal position of optical module by predetermined focal position K
0Turn right and move arriving a specific focal position, this specific focal position can be regarded as the best focus position that in this is proofreaied and correct, determined.
In Fig. 5, the first focus value f (a) is less than the second focus value f (b), thus focal position adjustment unit 330 with the focal position of optical module by predetermined focal position K
0Turn right and move to arrive specific focal position; Yet if the first focus value f (a) is greater than the second focus value f (b), 330 of focal position adjustment units will be with the focal position of optical module by predetermined focal position K
0The side shifting of turning left is to arrive specific focal position, and in like manner, if the first focus value f (a) equals the second focus value f (b), then focal position K is scheduled in expression
0Promptly be the best focus position of this correction, so the focal position of optical module need not move.
In addition, focal position adjustment unit 330 in a calibration cycle T shown in Figure 4 with the focal position of optical module by predetermined focal position K
0Be adjusted to specific focal position; And in another embodiment of the present invention; The a plurality of time points of focal position adjustment unit 330 in calibration cycle T are adjusted to specific focal position with the focal position of optical module one by one; Wherein wantonly two adjacent time points have identical distance in the said a plurality of time points in the calibration cycle T, and focal position adjustment unit 330 each time point in said a plurality of time points uses same adjusted value to adjust the focal position of this optical module.For example, suppose correction signal V
eThe adjustment amount that is corresponded to is 0.3, then can be divided into 10 time points in the calibration cycle T, and the adjustment amount of each time point focal position is 0.03.
In that correction time (the 2nd correction time shown in Figure 4), before, totalizer 340 was with correction signal V next time
eAnd predetermined focal position K
0Obtain the predetermined focal position K of correction time next time mutually
1, afterwards, when the 2nd correction time shown in Figure 4, optical module can detect earlier to produce a focal position as shown in Figure 5 and the characteristic curve or the table of comparisons of focus value, and then, focus signal generation unit 310 is according to predetermined focal position K
1To determine the first focus signal V
aAnd the second focus signal V
b, afterwards, as described in the 1st correction time, comparer 322 is the first focus signal V relatively
aAnd the second focus signal V
bTo produce comparison signal V
c, wave filter 324 is then to comparing signal V
cCarry out filtering operation to produce comparison signal V after the filtering
LP, integrator 326 is according to comparison signal V after the filtering
LPTo produce correction signal V
e, last, the focal position adjustment unit is again according to correction signal V
eThe focal position of optical module (also promptly is scheduled to focal position K by present focal position
1) be adjusted to a specific focal position.In simple terms, focal position adjustment unit employed one predetermined focal position (K in a present correction time
N+1) the last specific focal position that in a last correction time, is adjusted to for the focal position of optical module (also is K
N+1=K
n+ V
e).
In ensuing each correction time; Circuit 300 all repeats above-mentioned steps and is adjusted to corresponding specific focal position with the focal position with optical module, and the specific focal position that wherein optical module was adjusted to after correction time each time all can be considered the best focus position that is determined during correction time in this time.In addition, though focal position that when correction time each time, is detected and focus value characteristic curve or the table of comparisons all can not be to be symmetry because of The noise, thereby the focus signal V that causes focus signal generation unit 310 to be produced
a, V
bAlso can receive The noise and can't reflect the value that it is correct, yet, because wave filter 324 receives a plurality of comparison signal V respectively in a plurality of correction times
cTherefore, can the part filtering of noise be made comparison signal V after the filtering that wave filter 324 exported
LPCan get rid of The noise, and the correction signal V that integrator 326 is exported
eThe focal position of optical module also can more correctly reflect required corrected value, so that can be adjusted to best focus position.
Concise and to the point conclusion the present invention; The present invention is that the characteristic curve (or table of comparisons) that utilizes ideal to go up focal position and focus value is a symmetrical curve and the characteristic that a peak value is only arranged; Compare two corresponding focus signals of focal position; And decide the adjustment amount of focal position according to its comparative result, in addition, the present invention utilizes the phase-locked loop to come two pairing focus signals of focal position of comparison especially and produces the focal position of correction signal with the adjustment optical module; Thus, can eliminate The noise and the focal position of optical module is adjusted to best focal position.
The above is merely the preferred embodiments of the present invention, and all equalizations of being done according to claim scope of the present invention change and modify, and all should belong to protection scope of the present invention.
Claims (8)
1. circuit in order to the focal position of proofreading and correct an optical module includes:
One correction signal generation unit; According to producing a correction signal corresponding to one first focus signal of one first focal position and corresponding to one second focus signal of one second focal position at least, wherein this first focal position differs from this second focal position in order to simultaneously; This correction signal generation unit includes:
One comparer is used for relatively this first focus signal and this second focus signal to produce a comparison signal;
One wave filter is coupled to this comparer, is used for this comparison signal is carried out filtering operation to produce comparison signal after the filtering;
One integrator is coupled to this wave filter, is used for according to comparison signal after this filtering to produce this correction signal;
One focal position adjustment unit is coupled to this correction signal generation unit, is used for being adjusted to a specific focal position according to this correction signal with the focal position with this optical module; And
One focus signal generation unit; Be coupled to this correction signal generation unit; Be used for according to a predetermined focal position determining this first focal position and this second focal position, and produce this second focus signal that corresponds to this first focus signal of this first focal position and correspond to this second focal position; This first focal position equals this second focal position and the distance of being somebody's turn to do predetermined focal position with the distance that should be scheduled to focal position;
Wherein in a plurality of correction times in each correction time; This focal position adjustment unit all can begin to adjust focal position to the corresponding one specific focal position of this optical module according to the output of this integrator, and the last specific focal position that in a last correction time, is adjusted to of this focal position adjustment unit focal position that employed one predetermined focal position is this optical module in a present correction time.
2. circuit as claimed in claim 1; Wherein this focus signal generation unit obtains one second focus value that corresponds to one first focus value of this first focal position and correspond to this second focal position according to the focal position and the focus value table of comparisons, and respectively according to this first focus value and this second focus value to produce this first focus signal and this second focus signal.
3. circuit as claimed in claim 1; Wherein be spaced apart a calibration cycle between the zero-time of two adjacent correction times, a plurality of time points of this focal position adjustment unit in this calibration cycle are adjusted to corresponding this specific focal position with the focal position of this optical module one by one.
4. circuit as claimed in claim 3; Wherein wantonly two adjacent time points have identical distance in the said a plurality of time points in this calibration cycle, and this focal position adjustment unit each time point in said a plurality of time points uses same adjusted value to adjust the focal position of this optical module.
5. method in order to the focal position of proofreading and correct an optical module includes:
Simultaneously according to producing a correction signal corresponding to one first focus signal of one first focal position and corresponding to one second focus signal of one second focal position at least, wherein this first focal position differs from this second focal position; This step comprises:
Relatively this first focus signal and this second focus signal are to produce a comparison signal;
This comparison signal is carried out filtering operation to produce comparison signal after the filtering;
According to comparison signal after this filtering to produce this correction signal;
Be adjusted to a specific focal position according to this correction signal with focal position with this optical module;
Wherein, determining this first focal position and this second focal position, and produce this second focus signal that corresponds to this first focus signal of this first focal position and correspond to this second focal position according to a predetermined focal position; This first focal position equals this second focal position and the distance of being somebody's turn to do predetermined focal position with the distance that should be scheduled to focal position;
In a plurality of correction times in each correction time; Begin to adjust focal position to the corresponding one specific focal position of this optical module according to the correction signal that produced, and the last specific focal position that in a last correction time, is adjusted to of the focal position that employed one predetermined focal position is this optical module in a present correction time.
6. method as claimed in claim 5; Wherein producing this second focus signal step correspond to this first focus signal of this first focal position and to correspond to this second focal position includes: obtain one second focus value that corresponds to one first focus value of this first focal position and correspond to this second focal position according to a focal position and the focus value table of comparisons, and respectively according to this first focus value and this second focus value to produce this first focus signal and this second focus signal.
7. method as claimed in claim 5 wherein is spaced apart a calibration cycle between the zero-time of two adjacent correction times, and the step that in calibration cycle, the focal position of this optical module is adjusted to corresponding this specific focal position includes:
A plurality of time points in this calibration cycle are adjusted to corresponding this specific focal position with the focal position of this optical module one by one.
8. method as claimed in claim 7; Wherein wantonly two adjacent time points have identical distance in the said a plurality of time points in this calibration cycle, and the said a plurality of time points in this calibration cycle include the step that the focal position of this optical module is adjusted to corresponding this specific focal position one by one:
Each time point uses same adjusted value to adjust the focal position of this optical module in said a plurality of time points.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN200910008315XA CN101813818B (en) | 2009-02-20 | 2009-02-20 | Circuit used for correcting focusing position of optical module and correction method thereof |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN200910008315XA CN101813818B (en) | 2009-02-20 | 2009-02-20 | Circuit used for correcting focusing position of optical module and correction method thereof |
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| CN101813818A CN101813818A (en) | 2010-08-25 |
| CN101813818B true CN101813818B (en) | 2012-07-04 |
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| CN104601886B (en) * | 2015-01-13 | 2018-03-27 | 烟台艾睿光电科技有限公司 | A kind of control method and device for the focusing of infrared image motor |
| CN106341598A (en) * | 2016-09-14 | 2017-01-18 | 北京环境特性研究所 | Optical-lens automatic focusing system and method thereof |
| CN110319851B (en) * | 2018-03-30 | 2022-03-01 | 北京百度网讯科技有限公司 | Sensor correction method, device, equipment and storage medium |
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