CN1203368C - Focus regulating method for photographic lens - Google Patents
Focus regulating method for photographic lens Download PDFInfo
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- CN1203368C CN1203368C CN 02107028 CN02107028A CN1203368C CN 1203368 C CN1203368 C CN 1203368C CN 02107028 CN02107028 CN 02107028 CN 02107028 A CN02107028 A CN 02107028A CN 1203368 C CN1203368 C CN 1203368C
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Abstract
To provide a focus adjusting method of photographic lens capable of taking measures based on actual photographing of a general subject having high accuracy and realizing the shortening of the adjusting time. In the focus adjusting method of photographic lens, a slip shaped chart is arranged at a place aparting from the photographic lens, chart images imaged by the photographic lens are photographed at the imaging position and around the positon, MTF value is caculated based on the photographing result, then the focus adjusting value of the photographic lens is determined according to the MTF value. Moreover, the focus adjusting value is stored in a memory of the camera, and the photographic lens is adjusted according to the focus adjusting value providing an optimal imaging position thereof.
Description
Technical field
The present invention relates to focal point adjusting method, focus adjusting device and the camera of phtographic lens.
Background technology
Past, in manufacturing process with in repairing, detect the focal position of phtographic lens, adjust the focus of phtographic lens, one of its method is: utilize optical bench to carry out visualization to being arranged on the figure of being described on the chart on the assigned position, carry out the focus adjustment.Another kind method is to utilize photoelectric collimator to measure light quantity on the chart, adjusts the focal position.
But, utilize optical bench to carry out the method that focus is adjusted, be a kind of sensation inspection after all, so different survey crews are measured, the difference of generation is very big, is difficult to contrast and resolution number of lines are carried out quantitatively can not adjusting exactly.And, adjust the activity duration growth, the survey crew fatigue strength is also big, and operating efficiency is also low.
On the other hand, the method for utilizing photoelectric collimator to carry out the focus adjustment is the evaluation to light quantity, so the problem of existence is fully to adapt to the real scene shooting work of taking general subject.
Summary of the invention
The present invention is in order to solve above-mentioned unconformable problem, the camera that its purpose is to provide a kind of like this phtographic lens focal point adjusting method, focus adjusting device and adjusts like this, it can be corresponding to the optimal focus position in the real scene shooting of taking general subject, precision is also high, can also shorten the adjustment time.
Focal point adjusting method method of the present invention has following operation:
Figure by the slit-shaped of above-mentioned phtographic lens on a plurality of somes photographs assigned positions of the optical axis direction of above-mentioned phtographic lens;
Shooting results according to above-mentioned shooting operation calculates mtf value;
According to the output that above-mentioned mtf value calculation process is obtained, decision and the corresponding phtographic lens of the locational figure of afore mentioned rules focal position.
Moreover the focus adjusting device of phtographic lens of the present invention has:
Chart on the assigned position (recording chart);
Camera head is used for taking by phtographic lens the figure of the slit-shaped on this chart;
The MTF calculation element is used for calculating mtf value according to the output of above-mentioned camera head; And
The phtographic lens locating device is used for deciding and the corresponding above-mentioned phtographic lens of above-mentioned chart focal position data according to the output of MT reconnaissance F calculation element;
Memory control device is in the storer of above-mentioned focal position data storage in the camera.
Moreover camera of the present invention has: phtographic lens; Drive unit is used to drive this phtographic lens;
Distance measuring equipment is used to detect the distance of leaving subject and the focus state of phtographic lens;
Storer is used to store the focus adjusted value; And
Control device is used for output and above-mentioned focus adjusted value according to above-mentioned distance measuring equipment, calculates the drive amount of above-mentioned phtographic lens, and above-mentioned phtographic lens is carried out drive controlling;
Utilize above-mentioned phtographic lens to take the slit-shaped figure of assigned position, calculate mtf value;
The focus adjusted value of being stored in the above-mentioned storer is the value that the mtf value according to above-mentioned phtographic lens determines.
Description of drawings
Fig. 1 is the figure of expression as the formation of the focus adjusting device of a kind of embodiment of the present invention.
Fig. 2 is the frame assumption diagram of formation of focus adjusting device of a kind of embodiment of the above-mentioned Fig. 1 of expression.
Fig. 3 is a kind of line chart, and it is illustrated in the focus adjusting device of a kind of embodiment of above-mentioned Fig. 1, when measuring MTF, changes with the Z position with the measured value of the corresponding mtf value of figure of figure portion of central authorities.
Fig. 4 is a kind of line chart, and it is illustrated in the focus adjusting device of a kind of embodiment of above-mentioned Fig. 1, when measuring MTF and the measured value of the corresponding mtf value of figure of outline map portion change with the Z position.
Fig. 5 is the process flow diagram that the focus adjustment in the focus adjusting device of a kind of embodiment of above-mentioned Fig. 1 is handled.
Fig. 6 is a kind of line chart, and it is illustrated in the focus adjusting device of a kind of embodiment of above-mentioned Fig. 1, and with an example of the measurement result of the corresponding mtf value of each figure, wherein, the corresponding relation that each mtf value changes is: Fig. 6 (A) is corresponding to center figure portion; Fig. 6 (B) is corresponding to the outline map portion of the 1st quadrant; Fig. 6 (C) is corresponding to the outline map portion of the 2nd quadrant; Fig. 6 (D) is corresponding to the outline map portion of the 3rd quadrant; Fig. 6 (E) is corresponding to the outline map portion of the 4th quadrant.
Fig. 7 is illustrated in the focus adjusting device of an embodiment of above-mentioned Fig. 1, based on the figure of the image planes of each focal position of mtf value measurement result.
Embodiment
Below with reference to the accompanying drawings, describe embodiments of the invention in detail.
Fig. 1 is the figure of expression as the formation of the focus adjusting device of one embodiment of the present of invention.Fig. 2 is the structured flowchart of the formation of the above-mentioned focus adjusting device of expression.And in the image pickup part 1 (aftermentioned) of the focus adjusting device 10 that constitutes present embodiment, the direction that parallels with the optical axis Od of the optical axis Oc of phtographic lens 64 and phtographic lens 12 is the Z direction; With the perpendicular direction of Z direction, left and right directions is a directions X, and above-below direction is the Y direction.
The focus adjusting device 10 of present embodiment is a kind of like this device, promptly on a plurality of points of optical axis direction, measure the yardstick of the photographic images that is adjusted camera 6 being estimated with the conduct of real scene shooting corresponding M TF (Modulation Transfer Function) value, the focal position of above-mentioned camera 6 is adjusted.The contrast-response characteristic of mtf value presentation video, briefly, it is a kind of ratio that reappears after how many presentation video contrasts reduces, and also can be regarded as the transfer rate or the reduction rate of contrast.
In above-mentioned camera 6, usually, because the scale error of the constituent part of phtographic lens frame and rigging error, perhaps signal-lens refractive index error, lens thickness, airspace, with respect to the lens off-centre of picture frame etc. cause the focal position to change comprehensively.The peak that is mtf value changes.Utilize above-mentioned focus adjusting device 10, detect this focal position according to the measurement of above-mentioned mtf value and change, above-mentioned focal position data (focus adjusted value) are stored in the interior storer of camera 6.
This camera 6 have a kind of be used to measure and subject between distance or detect the non-diagram distance measuring equipment of the focus state of phtographic lens.And, the control circuit of this camera 6 is read the focal position data that are stored in the above-mentioned storer when taking, carry out correction calculation according to the data that these data come above-mentioned distance measuring equipment is exported, calculate the drive amount of phtographic lens, drive phtographic lens according to this drive amount.
Carry out this correction calculation, its purpose is to improve the focusing accuracy of this camera 6.
And, every camera is measured above-mentioned data respectively, the data that record are stored into respectively in each camera corresponding with it, like this, respectively every camera is eliminated comprehensive focal position variation error.
In above-mentioned focus adjusting device 10, the focus state of photographic images utilizes figure table unit 5, identifies according to the mtf value at the chart picture edge outside mtf value on the phtographic lens optical axis Oc at chart picture center and the optical axis.And, above-mentioned optical axis Oc gone up and the each point at edge on the focus departure take into account, obtain the optimal focus position of picture integral body, in the storer of this information stores in the above-mentioned camera.
Above-mentioned focus adjusting device 10 is adjusted control part 2, keyboard 3, monitor 4 and figure table unit 5 by image pickup part 1, focus and is constituted as shown in Figure 1 and Figure 2.On this figure table unit 5, depict a plurality of slit-shaped figure described later.Be installed in the front of the image pickup part main body 18 of image pickup part 1 as the camera 6 that is adjusted portion.
Above-mentioned image pickup part 1 as shown in Figure 1 and Figure 2, its component part has: as camera 11, imaging control part 14, a drive division 15 of camera head and the image pickup part main body 18 that is used to cover each part mentioned above.The installation portion of one opening as camera 6 arranged in the front of this image pickup part main body 18.
Above-mentioned camera 11, its component part comprises: have the phtographic lens 12 of optical axis Od and have picture pick-up device CCD and the camera head 13 of shooting treatment circuit.Figure picture by the lens 64 of above-mentioned camera 6 carry out imaging carries out imaging by phtographic lens 12 again on the imaging surface of above-mentioned CCD, by this CCD it is transformed into electric signal.Above-mentioned shooting treatment circuit is handled the shooting output signal of above-mentioned CCD, and it is outputed to the CPU21 side as view data.
And, in this manual, the content that is depicted on the chart is called " figure "; This figure that is undertaken by phtographic lens after the imaging is called " figure picture ".
The CCD of 14 pairs of camera heads 13 of image control part and shooting treatment circuit carry out drive controlling.Above-mentioned drive division 15, its component part comprises: the XY axle that is installed on the image pickup part main body 18 drives platform (XY axle drive division) 16 and Z axle driving platform (Z axle drive division) 17.Drive installation camera 11 on the platform 16 at above-mentioned XY axle, this camera 11 is driven on directions X and Y direction.And, drive the above-mentioned XY axle driving of installation platform 16 on the platform 17 at the Z axle, this XY axle is driven platform 16 on the Z direction, drive, above-mentioned camera 11 is driven on the Z direction.
Above-mentioned focus is adjusted control part 2, and its component part comprises: to the RAM portion 29 that adjusts control part is inner and above-mentioned image pickup part 1 is controlled CPU21 and arithmetic expression information etc. is stored.
In above-mentioned CPU21, be equipped with: the control part of when adjusting, the action of image pickup part 1 and camera 6 being controlled, as the MTF operational part 22 of MTF calculation element and as the focal position operational part 23 of phtographic lens locating device.MT reconnaissance F operational part 22 is obtained the relevant view data of figure picture a kind of and output from above-mentioned camera head 13, obtains the mtf value of this figure picture by computing.Above-mentioned focal position operational part 23 is according to the mtf value from 22 outputs of MT reconnaissance F operational part, obtains the focal position of camera 6 by computing, by CPU61 the focal position data is written in the EEPROM65 of camera 6.
Keyboard 3 is finished various settings when carrying out focus adjustment processing used, and monitor 4 is used for confirming the operating state of focus adjustment processing.
Above-mentioned chart (チ ヤ one ト) unit 5 is the test resolutions on a kind of like this photographic images frame, and promptly it is disposed in as leaving the standard photo distance L1 of the subject distance when being used for common camera shooting, for example having only 3 meters position.Be positioned at center figure (the チ ヤ one ト) 5a of portion on the lens axis Oc of camera 6, on the 5e of outline map portion of the 5d of outline map portion of the 5c of outline map portion of the 5b of outline map portion of locational the 1st quadrant of photographic images edge edge on XY plane, the 2nd quadrant, the 3rd quadrant and the 4th quadrant, depict the figure of slit-shaped respectively.
And the above-mentioned center 5a of figure portion is as prescribed distance (the spatial frequency f of directions X and Y direction
0Article=10 ,/mm) the slit-shaped figure picture of (spatial frequency=spatial frequency) is made of vertical figure and horizontal figure.Above-mentioned each outline map portion is set at prescribed distance (the spatial frequency f of radiation direction (hereinafter referred to as the S direction) and garden Zhou Fangxiang (hereinafter referred to as the M direction) respectively
0Article=10, slit-shaped figure/mm).Above-mentioned spatial frequency f
0Article=10 ,/mm is applicable to the focus adjustment, is because this spatial frequency and more high spatial frequency f described later
1, f
2Compare the photographic picture quality in the time of to be applicable to general real scene shooting better.
Shooting picture during according to the real scene shooting estimated also can be used and describe to be higher than f
0Spatial frequency f
1And f
2The figure table unit of figure.
Camera 6 has: phtographic lens 64 wherein has optical axis Oc; CPU61 is used to control whole camera; Lens drive division 63 is used to drive phtographic lens 64, makes its forward-reverse; Drive control part 62 is used to control said lens drive division 63; And EEPROM65 etc., the required data of shooting such as focal position data (focus adjusted value) that are used to store phtographic lens 64.
And camera 6 is installed in the front of above-mentioned image pickup part main body 18, and its state is: when the focus adjustment was handled, the optical axis Oc of phtographic lens 64 was with respect to the shooting optical axis Od keeping parallelism of phtographic lens 12 described later.
Below describe the processing actions such as mtf value measurement of the phtographic lens 64 of the focus adjusting device 10 that adopts above-mentioned formation in detail.
A camera 6 and a drive division 15 are set under the mtf value measurement state at optical axis Oc center or picture edge.That is to say, bonnet 66 is placed under the state of opening, camera 6 is installed on the image pickup part main body 18 of photography portion 1.Whether the center of the optical axis Oc of the phtographic lens 64 of the above-mentioned camera 6 of inspection affirmation at this moment and the 5a of center figure portion of figure table unit 5 is consistent.And, phtographic lens 64 is reached with respect on the focusing position in the design of above-mentioned standard photo distance L1.Under above-mentioned camera settings state, the position of aperture plane 67 becomes the virtual image position in the design of chart.Above-mentioned aperture plane 67 is and corresponding to of the film face in when photography.
With optical axis Oc be center when measuring mtf value, the XY axle worktable 16 by correct drive division 15 drives, and makes the optical axis Od of phtographic lens 12 of camera 11 consistent with the optical axis Oc of the phtographic lens 64 of camera 6.
And, during the mtf value at the edge outside measuring optical axis, by above-mentioned XY axle worktable 16 is driven, on the graph position of the 5b of outline map portion of arbitrary quadrant of the 1st to the 4th quadrant that the desire that makes the optical axis Od of the phtographic lens 12 of camera 11 be registered to the aperture plane 67 of camera 6 is measured, 5c, 5d, 5e.
When measuring the mtf value at optical axis Oc center, when perhaps measuring the mtf value at edge, utilize the Z axle to drive worktable 17 camera 11 is moved on the Z direction, that is to say, by on optical axis direction, driving, the focus point of phtographic lens 12 is moved up in the front and back of aperture plane 67.And, the mtf value of measurement pattern respectively on a plurality of points of the optical axis direction of phtographic lens 64.When at this moment, being positioned at the focusing point of the phtographic lens 12 of above-mentioned camera 11 on the aperture plane 67 as Z direction side-play amount (defocus amount) the deviation post Zd=0 of standard.And the Z direction deviation post Zd during the rear side that is positioned at aperture plane 67 (rear side) is as+side; Z direction deviation post Zd when being positioned at front side (object side) is as a side.
When camera 11 is positioned at above-mentioned Z direction deviation post Zd and goes up, the figure picture of the 5a of center figure portion that takes by phtographic lens 64 or the figure picture of outline map (for example outline map 5e of the 4th quadrant), imaging on the CCD imaging surface is transformed into electric image pickup signal by CCD.The image pickup signal of above-mentioned figure picture is output in the CPU21 by camera head 13.By MTF operational part 22 it is calculated to be the mtf value relevant with above-mentioned figure then.
Fig. 3 is the line chart of the pairing variation in Z position of measured value of the mtf value of the expression figure that relates to the 5a of center figure portion.Camera 11 is moved on the optical axis direction of phtographic lens 64, on a plurality of points of optical axis direction, measure.By increasing this measurement point, can obtain to come down to the data of linearity, so, on figure, express straight line.
This line chart represents to relate to the variation of the mtf value of different graphic, expresses various deviation post Zd with respect to the Z direction (optical axis direction) of the deviation post Zd=0 on the aperture plane 67.And, among the figure, the f of the above-mentioned center 5a of figure portion
0, f
1, f
2Curve represent the spatial frequency f of curve map respectively
0Article=10 ,/mm, f
1Article=20 ,/mm, f
2Article=30 ,/mm, the variation of mtf value of vertical or horizontal figure.
And, in the focus adjusting device 10 of present embodiment, for example, to the spatial frequency f of the strongest vertical figure of common subject photography adaptability
0Article=10 ,/the MTF data of the curve (solid line) of mm are applicable to the focus adjustment.And the data mean value that also can adopt vertical figure and horizontal figure is as mtf value.
In the measurement result of above-mentioned Fig. 3,, be peak value (peak point P0) at Zd=0.00mm place mtf value for the figure of the center figure 5a of portion.That is to say, be the focal position on the indication window diametric plane 67.The calculating of this peak point is undertaken by the focal position operational part 23 of CPU21.
Secondly, when the mtf value at metrophotography frames images edge, when for example measuring the edge mtf value of the 4th quadrant, the XY axle worktable 16 of correct drive division 15 drives, and the optical axis Od of the phtographic lens 12 of camera 11 is registered on the picture position of the 5e of outline map portion of the 4th quadrant of the figure table unit 5 on the aperture plane 67.And, the same during with the mtf value of measuring optical axis Oc center, utilize Z axle driving worktable 17 on the Z direction, to drive camera 11 on one side, Yi Bian measure mtf value.
Fig. 4 is the figure of variation of measured value of the mtf value of the expression figure that relates to the 5e of outline map portion.And, among the figure, f
0, f
1, f
2Curve representation space frequency f respectively
0Article=10 ,/mm, f
1Article=20 ,/mm, f
2Article=30 ,/and the variation of mtf value during mm, solid line is represented the mtf value of S direction figure; Dotted line is represented the mtf value of M direction figure.In the focus adjusting device 10 of present embodiment, be suitable for the spatial frequency f of S direction figure
0Article=10 ,/ f during mm
0The variation of mtf value of curve (solid line).
Relating to the measurement result of mtf value of the figure of the 5e of outline map portion, is peak value (peak point P4) at deviation post Zd=+0.20mm place.That is to say that its expression is the focal position of the 5e of outline map portion of the 4th quadrant from rearward the fall back peak P4 of 0.20mm of aperture plane 67.The calculating of this peak point is undertaken by the focal position operational part 23 of CPU21.
The 5b of outline map portion of the 1st～the 3rd quadrant beyond equally, resembling very with the 4th, the aperture plane 67 of 5c, 5d are that the variation of the pairing mtf value of each deviation post Zd at center is also measured.Obtain peak P1, P2, the P3 of the pairing focal position of figure of the sort of expression outline map portion according to its measurement result.
Then, according to above-mentioned each figure portion the deviation post Zd data of corresponding each peak (focal position) P0, P1, P2, P3, P4, carry out computing by the average calculating operation method according to the rules of the focal position operational part 23 in the CPU21, obtain the focal position Pm of the frames images integral body of phtographic lens 64.This focal position Pm data are as the focusing overhang data of camera 6, and promptly focal position data (focus adjusted value) are sent in the CPU61 of camera 6 sides, are written in the EEPROM65.These data are used to provide the conjugate planes to above-mentioned standard subject distance L 1.
Below utilize process flow diagram and Fig. 6, Fig. 7 of Fig. 5, be described more specifically the focus adjustment action of being undertaken by focus adjusting device 10.
Fig. 6 is the line chart of example of the measurement result of 5 pairing mtf values of curve map of expression.They represent the variation of the mtf value of following each several part respectively, and wherein, Fig. 6 (A) is corresponding to the center figure 5a of portion; Fig. 6 (B) is corresponding to the 5b of outline map portion of the 1st quadrant; Fig. 6 (C) is corresponding to the 5c of outline map portion of the 2nd quadrant; Fig. 6 (D) is corresponding to the 5d of outline map portion of the 3rd quadrant; Fig. 6 (E) is corresponding to the 5e of outline map portion of the 4th quadrant.And Fig. 7 is the figure of expression according to each focal position image planes of above-mentioned mtf value measurement result.
When adjusting focus, at first focus adjusting device 10 and figure table unit 5 and camera 6 are set to mtf value shown in Figure 1 and measure state.That is to say, camera 6 is set on the image pickup part main body 18, make the centrally aligned of the 5a of center figure portion of the optical axis Oc of phtographic lens 64 and figure table unit 5.Further make the camera lens 64 of camera 6 reach with the corresponding design of standard photo distance L1 on the focusing position on, the focus adjustment of beginning Fig. 5 is handled.
In S1 step, utilize the XY axle to drive worktable 16 and the optical axis Od of the phtographic lens 12 of camera 11 be registered on the optical axis Oc of above-mentioned phtographic lens 64, the figure of the center figure 5a of portion as the state that can take.Utilize on one side the Z axle to drive worktable 17 camera 11 is moved on the Z direction, measure the mtf value of the figure that relate to center figure portion 5e variation (referring to Fig. 6 (A)) with respect to each deviation post (side-play amount) Zd on one side.This program step is identical with the measurement that utilizes above-mentioned Fig. 3 to describe.
In S2 step, drive the XY axle and drive worktable 16 the optical axis Od of camera 11 is registered on the image space of the 5b of outline map portion, 5c, 5d, 5e of the 1st～the 4th quadrant successively, the figure of each outline map portion as the state that can take.Utilizing the Z axle to drive worktable 17 moves camera 11 on the Z direction, with respect to the variation (referring to Fig. 6 (B)～(E)) of each pan position (side-play amount) Zd, this step is identical with the measurement of above-mentioned Fig. 4 explanation with this mtf value of figure of measuring the outline map portion that relates to above-mentioned the 1st～the 4th quadrant.
Go on foot at S3, utilize focal position operational part 23 to calculate the deviation post Zd (P0) of focal position, this position is optical axis image planes positions, it can be given in S1 pacing amount optical axis Oc center mtf value peak point P0. for example, when having obtained the measurement result of above-mentioned Fig. 6 (A), can be in the hope of deviation post Zd (the P0)=0.00mm of the optical axis center image planes that can provide mtf value peak point P0.Be that mtf value peak point P0 is consistent with Zd=0.And, in Fig. 7, comprise the image planes 71 of above-mentioned peak point P0 position and the side-play amount Zd (P0) that can provide above-mentioned some P0 together.If phtographic lens 64 is stretched out, the image space of phtographic lens 64 is registered on the above-mentioned deviation post Zd (P0), so, can make at least on the subject at optical axis Oc center in focus and take.
Go on foot at S4, utilize focal position operational part 23 to obtain each deviation post Zd of image planes position (focal position), this position can be given in the outline map portion that relates to each quadrant of picture that above-mentioned S2 pacing measures figure mtf value peak point P1～P4. for example, when having obtained the measurement result of above-mentioned Fig. 6 (B)～(E), the deviation post that provides the 1st quadrant edge mtf value peak point P1 be Zd (P1)=-0.30mm.The deviation post that provides the 2nd quadrant edge mtf value peak point P2 be Zd (p2)=+ 0.2mm.The deviation post that provides the 3rd quadrant edge mtf value peak point P3 be Zd (P3)=+ 0.10mm.And, the deviation post that provides the 2nd quadrant edge mtf value peak point P4 be Zd (p4)=+ 0.20mm.At this, in focal position operational part 23, obtain the deviation post Zd (P1/4) that above-mentioned whole edges is provided fifty-fifty the average image planes position (average focal position, edge) of aiming at focus by arithmetic mean.That is to say and utilize following formula to try to achieve:
Zd(P1/4)＝{Zd(P1)+Zd(P2)+Zd(P3)+Zd(P4)}/4 …… (1)
If each deviation post data shown in Figure 6 are updated in the above-mentioned formula (1), then be edge average image planes deviation post Zd (P1/4)=+ 0.05mm.In Fig. 7, express the position of the Z direction of above-mentioned peak point P1, P2, P3, P4, above-mentioned edge average image planes deviation post Zd (P1/4) and comprise this deviation post Zd (P1/4) if image planes 72. phtographic lens 64 reach with the corresponding position of above-mentioned deviation post Zd (P1/4) on, so, at least, can be fifty-fifty on the subject at picture edge, taking in focus.
Go on foot at S5, the arithmetic mean of deviation post (side-play amount) Zd (P1/4) by the average image planes in above-mentioned edge and deviation post (side-play amount) Zd (P0) of above-mentioned optical axis center image planes is obtained a kind of deviation post (side-play amount) Zd (Pm) that can provide both sides centre position (focus adjustment point).That is to say and to obtain by following formula.
Zd(Pm)＝{Zd(P1/4)+Zd(P0)}/2 ……(2)
If deviation post Zd (P1/4)=+ 0.05mm and deviation post Zd (P0)=+ 0.00mm is updated in the above-mentioned formula (2), then can obtain deviation post Zd (Pm)=+ 0.025mm.And above-mentioned computing is carried out in focal position operational part 23, expresses above-mentioned deviation post Zd (Pm) and comprise the image planes 73 of above-mentioned deviation post Zd (Pm) in Fig. 7.
Go on foot at S6, deviation post Zd (Pm) data that can be given in the centre position (focus adjustment position) that the above-mentioned S5 step obtains as the focusing overhang data of the phtographic lens 64 that is equivalent to film face position, be focal position data (focus adjusted values), transmit and be written in the EEPROM65 of camera 6.
Then, the image pickup part main body 18 of camera 6 from focus adjusting device 10 disassembled, finish the focus adjustment and handle.
In the camera 6 that has carried out above-mentioned focus adjustment, at least when subject is positioned at gauged distance L1, if according to the camera lens overhang data that are written among the above-mentioned EEPROM65, phtographic lens 64 is carried out focus control, then can carry out the shooting of best focus optical axis Oc center and picture edge image.
If adopt the focus adjusting device 10 of above-mentioned present embodiment, Yi Bian camera 11 is moved on optical axis direction, Yi Bian send into the figure of optical axis center and the image pickup signal of edge pattern.And, automatically obtain the focal position because of the variation of the mtf value that the method for adjustment that adopts is a basis relates to each figure, so the focus adjustment of phtographic lens can be applicable to the real scene shooting situation of taking general subject, precision is also high, the adjustment time also can shorten.
In the focus adjusting device 10 of the foregoing description, the deviation post Zd (Pm) that provides a kind of centre position (focus adjustment position) is written in the EEPROM65.But be not limited in this,, obtain each focus and adjust deviation post, be written in the EEPROM65, so, can adapt to the phtographic lens of many specifications if adapt to the computing of phtographic lens characteristic.
For example, the deviation post Zd (Pm) of the pairing focal position of using as the photo of paying attention to central authorities of phtographic lens, if the focus of the mtf value that only utilizes optical axis Oc center is adjusted position data Zd (P0) separates with above-mentioned deviation post Zd (Pm) data, be written among the EEPROM65 individually, so, just can further improve the focusing accuracy when taking pictures, can shoot desirable photo.And, in the time will obtaining deviation post (photo of above-mentioned attention central authorities use the pairing focus of phtographic lens adjust the position), if for deviation post Zd (P1/4) with respect to the edge, pay attention to deviation post Zd (P0) side of optical axis center more, the deviation post Zd (Pm) of the centre position that is multiplied by assigned frequency and tries to achieve (focus adjustment position), be written in addition in the EEPROM65, so, just can take more practical photo.
Moreover, shine phtographic lens for macroscopic view, because it is more to take tiny subject, so, if improve spatial frequency, the figure table unit of above-mentioned spatial frequency f1=20 bar/mm or f2=30 bar/mm, measure mtf value, obtain the focal shift position, be written in the EEPROM65, so, also can take good photomacrograph.
The p ' the 0th of Fig. 3, the center mtf value peak point that adopts above-mentioned f1 to obtain; P " the 0th, the center mtf value peak point that adopts above-mentioned f2 to obtain.And, the P ' the 4th of Fig. 4, the edge MTD value peak point that adopts above-mentioned f1 to obtain.P " the 4th, the edge mtf value peak point that adopts above-mentioned f2 to obtain.Like this, peak changes with spatial frequency, so the spatial frequency that can select to meet the phtographic lens characteristic is carried out the focus adjustment.And, modified example as the foregoing description, also can be in the camera manufacture process or when repairing, come phtographic lens is carried out the adjustment of mechanical system according to above-mentioned focal position data, focal position data (focus adjusted value) are stored in the interior storer of camera replacing.
Effect of the present invention:
If employing the present invention, then can provide a kind of can be according to the real scene shooting situation of taking general subject Take countermeasure, precision is also high, also can shorten the focus of the phtographic lens of adjustment time and transfer Adjusting method, focus adjusting device and the camera of being adjusted like this.
Claims (26)
1. the focal point adjusting method of a phtographic lens is characterized in that, has following operation in the focal point adjusting method of phtographic lens:
On a plurality of points of the optical axis direction of above-mentioned phtographic lens, take the figure of the slit-shaped on the assigned position by above-mentioned phtographic lens;
According to the image pickup result of above-mentioned shooting operation, calculate mtf value;
Output according to MT reconnaissance F calculation process is obtained decides the focal position with respect to the above-mentioned phtographic lens of the locational figure of afore mentioned rules.
2. the focal point adjusting method of a phtographic lens is characterized in that, has following operation in the focal point adjusting method of phtographic lens:
On a plurality of points of above-mentioned optical axis direction, take the figure of the outer a plurality of slit-shaped of the figure of the slit-shaped on the optical axis of the above-mentioned phtographic lens on the chart of assigned position and optical axis respectively by above-mentioned phtographic lens;
Shooting results according to above-mentioned shooting operation comes, and calculates and the relevant mtf value of above-mentioned each figure;
The output that utilization obtains in MT reconnaissance F calculation process decides the pinpointed focus adjusted value of the outer pairing above-mentioned phtographic lens of a plurality of figures of figure on the above-mentioned optical axis and optical axis;
Above-mentioned focus adjusted value is stored in the storer in the camera.
3. the focal point adjusting method of phtographic lens as claimed in claim 2, it is characterized in that: above-mentioned focal position decision operation, according to the mean value of a plurality of peaks of the peak of the mtf value relevant and the mtf value relevant, determine the optimal focus position of above-mentioned phtographic lens with the outer figure of above-mentioned optical axis with the figure on the above-mentioned optical axis.
4. the focal point adjusting method of a phtographic lens is characterized in that: have following operation in the focal point adjusting method of phtographic lens:
The figure of slit-shaped is arranged on the position of leaving above-mentioned phtographic lens;
The image space of above-mentioned phtographic lens and near, shoot the figure picture that utilizes above-mentioned phtographic lens to carry out imaging;
Calculate mtf value according to above-mentioned shooting results;
According to above-mentioned mtf value, determine the focus adjusted value of above-mentioned phtographic lens;
Above-mentioned focus adjusted value is stored in the storer in the camera.
5. the focal point adjusting method of phtographic lens as claimed in claim 4 is characterized in that: above-mentioned focus adjusted value considers that the characteristic of above-mentioned phtographic lens determines.
6. the focal point adjusting method of phtographic lens as claimed in claim 4 is characterized in that: also have according to above-mentioned focus adjusted value and adjust phtographic lens, make the image space of phtographic lens become the operation of optimal focus position.
7. the focal point adjusting method of phtographic lens as claimed in claim 4 is characterized in that: above-mentioned shooting operation is the operation of taking the figure on the optical axis of above-mentioned phtographic lens.
8. the focal point adjusting method of phtographic lens as claimed in claim 4 is characterized in that:
Above-mentioned shooting operation is the operation of taking the outer a plurality of figures of the optical axis of figure on the optical axis of above-mentioned phtographic lens and above-mentioned phtographic lens;
MT reconnaissance F calculation process calculates each mtf value of relevant each figure.
9. the focal point adjusting method of phtographic lens as claimed in claim 8 is characterized in that: the outer a plurality of figures of above-mentioned optical axis are to be that center arrangement is on 4 positions at its edge with the figure on the above-mentioned optical axis.
10. the focal point adjusting method of phtographic lens as claimed in claim 4, it is characterized in that: above-mentioned focus adjusted value decision operation comprises according to above-mentioned mtf value and calculates the operation of peak value image planes position and the operation that decides the focus adjusted value according to above-mentioned peak value image planes position.
11. the focal point adjusting method of phtographic lens as claimed in claim 8 is characterized in that: above-mentioned focus adjusted value decision operation comprises following operation:
Calculate peak value image planes position respectively according to above-mentioned mtf value;
According to the outer relevant a plurality of peak value image planes position of a plurality of figures of optical axis, calculate average image planes position;
Calculate the centre position of peak value image planes position relevant and above-mentioned average image planes position with the figure on the optical axis;
Decide above-mentioned focus adjusted value according to above-mentioned centre position.
12. the focus adjusting device of phtographic lens is characterized in that having:
Chart, it is set on the assigned position that leaves detected material, and has described the figure of slit-shaped;
Camera head, be used for the image space that adopts above-mentioned phtographic lens and near, take the figure picture that obtains by above-mentioned phtographic lens;
The MTF arithmetic unit is used for calculating mtf value according to the shooting results of this camera head;
The focal position operational part is used for deciding according to above-mentioned mtf value the focus adjusted value of above-mentioned phtographic lens; And
Memory control device stores above-mentioned focus adjusted value in the storer in the camera into.
13. the focus adjusting device of phtographic lens as claimed in claim 12 is characterized in that, above-mentioned focus adjusted value considers that the characteristic of above-mentioned phtographic lens determines.
14. the focus adjusting device of phtographic lens as claimed in claim 12 is characterized in that also having the drive unit that above-mentioned camera head is moved.
15. the focus adjusting device of phtographic lens as claimed in claim 14 is characterized in that: above-mentioned drive unit comprises:
Z axle drive division is used to make camera head to move paralleling with above-mentioned optical axis on the direction;
XY axle drive division, be used to make camera head with the perpendicular direction of optical axis on move.
16. the focus adjusting device of a phtographic lens is characterized in that having:
Be positioned at the chart on the assigned position;
Camera head is used for taking by phtographic lens the figure of the slit-shaped on this chart;
The MTF calculation element is used for calculating mtf value according to the output of above-mentioned camera head; And
The phtographic lens locating device is used for the output according to MT reconnaissance F calculation element, decides the focal position data with the corresponding above-mentioned phtographic lens of above-mentioned chart; And
Memory control device is in the storer of above-mentioned focal position data storage in the camera.
17. the focus adjusting device of phtographic lens as claimed in claim 16 is characterized in that: above-mentioned camera head can move on the optical axis direction of above-mentioned phtographic lens.
18. the focus adjusting device of phtographic lens as claimed in claim 16 is characterized in that, above-mentioned focal position data consider that the characteristic of above-mentioned phtographic lens determines.
19. the focus adjusting device of a phtographic lens is characterized in that having:
Be positioned at the chart on the assigned position;
Camera head is used for taking by phtographic lens the figure of a plurality of slit-shaped on this chart;
The MTF calculation element is used for calculating mtf value according to the output of above-mentioned camera head;
Phtographic lens focus locating device is used for the output according to MT reconnaissance F calculation element, decides the focal position data with the corresponding above-mentioned phtographic lens of above-mentioned chart; And
Memory control device is in the storer of above-mentioned focal position data storage in the camera.
20. the focus adjusting device of phtographic lens as claimed in claim 19 is characterized in that: above-mentioned camera head is taken above-mentioned chart on a plurality of positions of the optical axis direction of above-mentioned phtographic lens.
21. the focus adjusting device of phtographic lens as claimed in claim 19 is characterized in that: above-mentioned camera head can the optical axis direction of above-mentioned phtographic lens and with the perpendicular direction of this optical axis direction on move.
22. the focus adjusting device of phtographic lens as claimed in claim 19 is characterized in that, above-mentioned focal position data consider that the characteristic of above-mentioned phtographic lens determines.
23. the focus adjusting device of a phtographic lens is characterized in that having:
Camera head is used for taking by phtographic lens the figure of the slit-shaped on the chart that is positioned on the assigned position;
The MTF calculation element is used for calculating mtf value according to the output of above-mentioned camera head;
Phtographic lens focus locating device is used for deciding according to the output of MT reconnaissance F calculation element the focal position data of above-mentioned phtographic lens, the conjugate planes of this data decision and the corresponding figure picture of the locational chart of afore mentioned rules; And
Memory control device is in the storer of above-mentioned focal position data storage in the camera.
24. camera, it is characterized in that having: the storer of the distance measuring equipment of the focus state of phtographic lens, the drive unit that drives this phtographic lens, the distance that detects subject or phtographic lens, storage focus adjusted value and according to the drive amount that the output and the above-mentioned focus adjusted value of above-mentioned distance measuring equipment calculates above-mentioned phtographic lens, carry out the control device of drive controlling to above-mentioned phtographic lens;
Utilize above-mentioned phtographic lens to take the figure of the slit-shaped that is positioned at assigned position, calculate mtf value;
Be stored in focus adjusted value in the above-mentioned storer and be the value that the mtf value according to above-mentioned phtographic lens determines.
25. camera as claimed in claim 24 is characterized in that: above-mentioned focus adjusted value is the value that a plurality of locational mtf value according to above-mentioned phtographic lens determines.
26. camera as claimed in claim 25 is characterized in that: above-mentioned mtf value be on the optical axis of above-mentioned phtographic lens and optical axis outside a plurality of locational measured value.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2001067419A JP2002267923A (en) | 2001-03-09 | 2001-03-09 | Focusing method of photographic lens |
| JP067419/2001 | 2001-03-09 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1374556A CN1374556A (en) | 2002-10-16 |
| CN1203368C true CN1203368C (en) | 2005-05-25 |
Family
ID=18925773
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 02107028 Expired - Fee Related CN1203368C (en) | 2001-03-09 | 2002-03-08 | Focus regulating method for photographic lens |
Country Status (2)
| Country | Link |
|---|---|
| JP (1) | JP2002267923A (en) |
| CN (1) | CN1203368C (en) |
Families Citing this family (21)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4314043B2 (en) * | 2003-03-10 | 2009-08-12 | キヤノン株式会社 | Imaging device |
| WO2005010817A1 (en) * | 2003-07-24 | 2005-02-03 | Olympus Corporation | Image processing device |
| CN100376912C (en) * | 2003-08-06 | 2008-03-26 | 鸿富锦精密工业（深圳）有限公司 | Image sensing module focusing device and method |
| JP2006323270A (en) * | 2005-05-20 | 2006-11-30 | Auto Network Gijutsu Kenkyusho:Kk | Camera device and focus adjustment method for camera device |
| CN100465783C (en) * | 2005-10-09 | 2009-03-04 | 致伸科技股份有限公司 | Focusing adjustment method of optical lens module |
| TWI412810B (en) * | 2006-09-01 | 2013-10-21 | Hon Hai Prec Ind Co Ltd | Focusing mechanism and method of using the same |
| EP2108231A4 (en) * | 2006-09-15 | 2011-08-31 | Tessera Tech Ireland Ltd | PICTURE SYSTEM WITH INCREASED IMAGE QUALITY AND CORRESPONDING METHODS |
| CN100582851C (en) * | 2007-12-04 | 2010-01-20 | 鸿富锦精密工业（深圳）有限公司 | Focus system and method for promoting resolving power of optical lens |
| CN101493646B (en) * | 2008-01-21 | 2012-05-23 | 鸿富锦精密工业（深圳）有限公司 | Optical lens detection device and method |
| JP5174589B2 (en) * | 2008-09-01 | 2013-04-03 | Ｊｕｋｉ株式会社 | Automatic focus adjustment method for electronic component mounting apparatus |
| CN101685240B (en) * | 2008-09-26 | 2011-07-20 | 致伸科技股份有限公司 | Method for judging focusing quality of image extracting device |
| JP5339884B2 (en) * | 2008-12-19 | 2013-11-13 | Ｊｕｋｉ株式会社 | Focus adjustment method and focus adjustment apparatus for imaging apparatus |
| CN102063009B (en) * | 2009-11-13 | 2012-11-14 | 蒋思远 | Camera testing system |
| CN102905075B (en) * | 2012-10-25 | 2015-06-17 | 信利光电股份有限公司 | Focusing and detecting methods |
| CN103257511B (en) * | 2013-04-27 | 2016-01-20 | 宁波舜宇光电信息有限公司 | A kind of Atomatic focusing method based on shot field curvature |
| CN104438131A (en) * | 2014-10-30 | 2015-03-25 | 安徽捷迅光电技术有限公司 | Camera translation correcting tool |
| CN104971904A (en) * | 2015-07-12 | 2015-10-14 | 安徽捷迅光电技术有限公司 | Lens correction tool |
| CN109361854A (en) * | 2018-10-24 | 2019-02-19 | 浙江大华技术股份有限公司 | A kind of video camera focus adjustment method, apparatus and system based on MTF |
| CN110514409A (en) * | 2019-08-16 | 2019-11-29 | 俞庆平 | A kind of quality inspection method and device of laser direct imaging camera lens |
| CN110888284B (en) * | 2019-11-12 | 2024-12-31 | 武汉灵智云创科技有限公司 | Focus point movement adjustment device |
| CN118435116A (en) * | 2021-12-21 | 2024-08-02 | 株式会社电装 | Focusing adjustment method |
-
2001
- 2001-03-09 JP JP2001067419A patent/JP2002267923A/en not_active Withdrawn
-
2002
- 2002-03-08 CN CN 02107028 patent/CN1203368C/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JP2002267923A (en) | 2002-09-18 |
| CN1374556A (en) | 2002-10-16 |
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