CN101271245A - Focal point adjusting method and focal point adjusting device in imaging apparatus - Google Patents
Focal point adjusting method and focal point adjusting device in imaging apparatus Download PDFInfo
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- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B7/00—Mountings, adjusting means, or light-tight connections, for optical elements
- G02B7/28—Systems for automatic generation of focusing signals
- G02B7/36—Systems for automatic generation of focusing signals using image sharpness techniques, e.g. image processing techniques for generating autofocus signals
- G02B7/365—Systems for automatic generation of focusing signals using image sharpness techniques, e.g. image processing techniques for generating autofocus signals by analysis of the spatial frequency components of the image
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- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B7/00—Mountings, adjusting means, or light-tight connections, for optical elements
- G02B7/28—Systems for automatic generation of focusing signals
- G02B7/36—Systems for automatic generation of focusing signals using image sharpness techniques, e.g. image processing techniques for generating autofocus signals
- G02B7/38—Systems for automatic generation of focusing signals using image sharpness techniques, e.g. image processing techniques for generating autofocus signals measured at different points on the optical axis, e.g. focussing on two or more planes and comparing image data
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- G03B—APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR
- G03B13/00—Viewfinders; Focusing aids for cameras; Means for focusing for cameras; Autofocus systems for cameras
- G03B13/32—Means for focusing
- G03B13/34—Power focusing
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Abstract
This invention provides a focal point regulating method and focal point regulating device in a camera device. In the camera, when a camera lens is moved at am optical axis direction to regulate a focusing position, the focusing position can be easily regulated with high precision even if the peak points of the picked contrast feature and MTF feature are unclear. A first and second test charts (CH1, CH2) each having an imaging pattern defined by white color and black color are set in front and rear of the target position (P) of an object, a focus lens (3) is moved in the direction of optical axis X, focal point evaluation value of the imaging pattern focused on an image element (5) is determined for each of the first and second test charts (CH1, CH2) in correspondence with the movement quantity of the focus lens (3), and the position of the focus lens (3) is set such that the focal point evaluation value in the first test chart (CH1) coincides with the focal point evaluation value in the second test chart (CH2).
Description
Technical field
The present invention relates in camera head, use the image letter that obtains by imaging apparatuss such as for example CCD pick-up lens to be set in the focus adjusting method and the focus-regulating device of focusing position.
Background technology
In the past, shown in Fig. 6 (a), known have a focus adjusting method that has used mountain-climbing mode (the り mode is stepped on the mountain), in camera heads such as camera 201, the contrast of the image projection light that detection is made a video recording, and the dollying optical system carries out focal adjustments so that the contrast of light becomes maximum.
Shown in Fig. 6 (b), the focus adjusting method of mountain-climbing mode is following method: when image pickup optical systems such as pick-up lens 202 and imaging apparatus 204 are in the focusing position with respect to subject 203, the contrast of the picture of subject 203 becomes maximum, defocus (focal shift) if produce, contrast can reduce, thereby regulate the position of pick-up lens 202, be target with the summit of contrast-response characteristic.
In addition, known have when regulating focus, the MTF of the shot object image that instrumentation is made a video recording (Modulation Transfer Function: modulation transfer function) regulate the method for focus.Specifically, have the variation that instrumentation is followed the MTF that moves of pick-up lens, set the position of pick-up lens, so that the MTF of predetermined spatial frequency is maximum focus adjusting method (for example, with reference to patent documentation 1 and patent documentation 2).
[patent documentation 1] Japanese kokai publication sho 62-284314 communique
[patent documentation 2] TOHKEMY 2005-258360 communique
But, according to obtaining the maximal value of contrast and the peaked focus adjusting method of MTF as mountain-climbing mode in the past, pick-up lens is come and gone to both sides to be moved, to detect contrast is the position of the best, so might damage for focal adjustments operability (that is, with make pick-up lens to a direction move the method for regulating make comparisons might damage operability).And, when near peak point, approaching smooth with respect to the contrast-response characteristic of defocus amount and MTF characteristic and can not clearly represent peak point, also might be not easy to regulate accurately the focusing position of pick-up lens.
Summary of the invention
So, the object of the present invention is to provide a kind of in camera head, when the dollying camera lens is regulated focusing position on optical axis direction, even the contrast-response characteristic of being made a video recording and the peak point of the focus evaluated value in the MTF characteristic are unclear, also can regulate focusing position accurately, and the focus adjusting method that can regulate easily.
The described invention of finishing in order to achieve the above object in the 1st aspect is the focus adjusting method in a kind of camera head, and this camera head has used pick-up lens and imaging apparatus, and above-mentioned pick-up lens guides to above-mentioned imaging apparatus with shot object image; Above-mentioned imaging apparatus carries out opto-electronic conversion to the above-mentioned shot object image by above-mentioned pick-up lens guiding, and output image signal; This focus adjusting method is in above-mentioned camera head, move above-mentioned pick-up lens along the optical axis that connects above-mentioned subject and above-mentioned imaging apparatus, the above-mentioned shot object image that is directed to above-mentioned imaging apparatus is focused, this focus adjusting method is characterised in that, on above-mentioned optical axis, set first test pattern and second test pattern of shooting pattern in front and back across the target location of above-mentioned subject with the white of being divided into and black; On above-mentioned optical axis direction, move above-mentioned pick-up lens, and respectively at above-mentioned first test pattern and second test pattern, obtain the focus evaluated value of the above-mentioned shooting pattern of imaging on above-mentioned imaging apparatus accordingly with the amount of movement of above-mentioned pick-up lens; Set the position of above-mentioned pick-up lens, so that the focus evaluated value of above-mentioned first test pattern is consistent with the focus evaluated value of above-mentioned second test pattern.
According to the focus adjusting method in the described camera head in the 1st aspect, on optical axis, set first test pattern and second test pattern of shooting pattern with the white of being divided into and black in front and back across the target location of subject, dollying camera lens on optical axis direction, respectively at first test pattern and second test pattern, obtain the focus evaluated value of the shooting pattern of imaging on imaging apparatus accordingly with the amount of movement of pick-up lens, and the position of setting pick-up lens, so that the focus evaluated value of first test pattern is consistent with the focus evaluated value of second test pattern, therefore, even the peak point of the focus evaluated value of the shot object image of making a video recording by pick-up lens is unclear, also focusing position can be regulated accurately, and its adjusting can be carried out easily.
Promptly, along optical axis dollying camera lens, as long as the set positions of the pick-up lens with the focus evaluated value of the focus evaluated value of first test pattern and second test pattern when consistent is a focusing position, therefore compare with mountain-climbing mode in the past, focusing position can be obtained accurately, and its adjusting time can be shortened.
In addition, focus adjusting method in the described camera head in the 1st aspect is as the described invention in the 2nd aspect, by across with the cross line of above-mentioned light shaft positive cross, above-mentioned first test pattern of balanced configuration and above-mentioned second test pattern, and be configured to the position that does not overlap separately, can be simultaneously make a video recording to first test pattern and second test pattern that separate along optical axis, focal adjustments easily and can detect the focusing position of pick-up lens accurately.
In addition, focus adjusting method in the described camera head in the 1st aspect or the 2nd aspect is as the described invention in the 3rd aspect, according to above-mentioned focus evaluated value is the index of spatial frequency composition amount of the marginal portion of the above-mentioned shooting pattern of expression, with utilize whole face to obtain focus evaluated value to compare, can easily obtain focus evaluated value.Promptly, when the shooting pattern is imaged onto on the imaging apparatus with focusing, become the image that the edge is clearly shown, the high fdrequency component of spatial frequency strengthens, on the other hand, when the focusing position with respect to imaging apparatus is offset, become the image that edge fog shows, the high fdrequency component of spatial frequency weakens, so as long as detect edge image, convert detected edge image differential to a some picture, this point is looked like to carry out Fourier transform get final product in the hope of the MTF that goes out optical system.
Focus adjusting method in the described camera head in the 1st aspect is as the described invention in the 4th aspect, by in described first test pattern and second test pattern, be set up in parallel a plurality of above-mentioned shooting patterns, with the shooting pattern is that odd number is compared, and can reduce noise effect and can obtain focus evaluated value accurately.That is, if the shooting pattern is a plurality of, relatively the focus evaluated value that obtains from each shooting pattern if there is the fluctuation that produces because of noise, is then removed the shooting pattern of noise on noise, can select the focus evaluated value of suitable shooting pattern.And, by in the central authorities of image or leave a plurality of shooting patterns of configuration on the position of central authorities, can set focal position in the image according to purposes, and can improve added value.
Next, the described invention in the 5th aspect is the focus-regulating device in a kind of camera head, and it has: pick-up lens, and it guides to imaging apparatus with shot object image; Imaging apparatus, it carries out opto-electronic conversion to the shot object image by above-mentioned pick-up lens guiding, exports the picture signal of a plurality of colors; And the focus evaluated value detecting unit, the amount of movement of itself and above-mentioned pick-up lens detects the focus evaluated value of the above-mentioned shot object image of imaging on above-mentioned imaging apparatus accordingly; Focus-regulating device in this camera head is according to by the detected testing result of above-mentioned focus evaluated value detecting unit above-mentioned pick-up lens being set to the precalculated position, this focus-regulating device is characterised in that, along above-mentioned optical axis, set first test pattern and second test pattern of shooting pattern in front and back across the target location of above-mentioned subject with the white of being divided into and black; Above-mentioned focus evaluated value detecting unit is respectively at above-mentioned first test pattern and second test pattern, obtains the focus evaluated value of the above-mentioned shooting pattern of imaging on above-mentioned imaging apparatus accordingly with the amount of movement of above-mentioned pick-up lens; Set the position of above-mentioned pick-up lens, so that the focus evaluated value of above-mentioned first test pattern is consistent with the focus evaluated value of above-mentioned second test pattern.
According to the focus-regulating device in the described camera head in the 5th aspect, same with the described invention in the 1st aspect, along optical axis, set first test pattern and second test pattern of shooting pattern with the white of being divided into and black in front and back across the target location of above-mentioned subject, obtain the focus evaluated value of the shooting pattern of imaging on imaging apparatus accordingly with the amount of movement of pick-up lens, and the position of setting pick-up lens, so that the focus evaluated value of first test pattern is consistent with the focus evaluated value of second test pattern, therefore, even the peak point of the focus evaluated value of the shot object image of making a video recording by pick-up lens is unclear, also focusing position can be regulated accurately, and its adjusting can be carried out easily.
In addition, focus-regulating device in the described camera head in the 5th aspect is as the described invention in the 6th aspect, above-mentioned first test pattern and second test pattern constitute across the cross line symmetry with above-mentioned light shaft positive cross, and constitute respectively and do not overlap, same with the described invention in the 2nd aspect thus, can be simultaneously make a video recording to first test pattern and second test pattern that separate along optical axis, focal adjustments easily and can detect the focusing position of pick-up lens accurately.
In addition, focus-regulating device in the described camera head in the 5th aspect or the 6th aspect is as the described invention in the 7th aspect, according to above-mentioned focus evaluated value is the index of spatial frequency composition amount of the marginal portion of the above-mentioned shooting pattern of expression, same with the described invention in the 3rd aspect, with utilize whole face to obtain focus evaluated value to compare, can easily obtain focus evaluated value.
According to focus adjusting method in the camera head of the present invention and focus-regulating device, on optical axis, set first test pattern and second test pattern of shooting pattern with the white of being divided into and black in front and back across the target location of subject, dollying camera lens on optical axis direction, and respectively at first test pattern and second test pattern, obtain the focus evaluated value of the shooting pattern of imaging on imaging apparatus accordingly with the amount of movement of pick-up lens, and the position of setting pick-up lens, so that the focus evaluated value of first test pattern is consistent with the focus evaluated value of second test pattern, therefore, even it is unclear near the peak point of the focus evaluated value of the shot object image of making a video recording by pick-up lens, also focusing position can be regulated accurately, and its adjusting can be carried out easily.
In addition, according to focus adjusting method in the camera head of the present invention and focus-regulating device, can make a video recording to first test pattern and second test pattern that separate along optical axis simultaneously, the operability that focal adjustments is used is good, and can detect the focusing position of pick-up lens accurately.
Description of drawings
Fig. 1 shows the skeleton diagram of the focus adjusting method in the camera head of one embodiment of the present of invention, and (a) figure expression first test pattern and second test pattern is provided with example, (b) the detected MTF characteristic of figure expression.
Fig. 2 is the block diagram that the structure of the camera head among the same embodiment is shown.
Fig. 3 is the figure that the assay method of the MTF among the same embodiment is shown.
Fig. 4 shows the process flow diagram of the step of the focus adjusting method among the same embodiment.
Fig. 5 is the variation of the test pattern shown in Fig. 1 (a).
Fig. 6 is the key diagram of focus adjusting method in the past.
Symbol description
1: camera head; 2: front lens; 3: condenser lens; 4: light filter; 5: imaging apparatus; 6:AFE (Analog Front End: AFE (analog front end)); 7: correlated double sampling circuit; 8: variable gain amplifier (AGC:Automatic Gain Control: automatic gain control); The 9:A/D converter; 10: focus detection portion; 11: sensor; 12: focus on drive division; 13:TG (Timing Generator: timing pulse generator); 15: focus-regulating device; The 16:MTF operational part; 17: the first operational parts; 17a, 18a: number of samples calculating part; 17b, 18b: step response calculating part; 17c, 18c: impulse response calculating part; 17d, the 18d:MTF calculating part; 18: the second operational parts; 23:ROM (Read Only Memory: ROM (read-only memory)); 24:CPU (CentralProcessing Unit: CPU (central processing unit)); The 25:MTF comparing section; 26: impact damper.
Embodiment
Next, with reference to the accompanying drawings an embodiment of focus adjusting method in the camera head of the present invention and focus-regulating device is described.
Fig. 1 shows the skeleton diagram of the focus adjusting method in the camera head of present embodiment, and (a) figure expression first test pattern and second test pattern is provided with example, (b) figure expression detected MTF characteristic this moment.In addition, Fig. 2 is the block diagram that the structure of the camera head among the same embodiment is shown, Fig. 3 is the figure that the assay method of the MTF among the same embodiment is shown, Fig. 4 shows the process flow diagram of the step of the focus adjusting method among the same embodiment, and Fig. 5 shows the figure of the variation of the test pattern among Fig. 1 (a).
Shown in Fig. 1 (a), camera head 1 has: condenser lens (so-called pick-up lens among the present invention) 3, and it constitutes and can move on the optical axis directions X; And imaging apparatus 5, it carries out opto-electronic conversion, output image signal to the shot object image that is directed by condenser lens 3.Focus adjusting method in the camera head of present embodiment is along the optical axis X that connects subject P and imaging apparatus 5, set the first test pattern CH1 and the second test pattern CH2 of shooting pattern with the white of being divided into and black in front and back across the target location of subject P, along optical axis X mobile focusing lens 3, by focus-regulating device 21, regulate the position of condenser lens 3, so that the picture focusing of the subject P of imaging on imaging apparatus 5.
In Fig. 1 (a), M is the distance of condenser lens 3 to subject P, N is the distance of condenser lens 3 to first test pattern CH1, F is the distance of condenser lens 3 to second test pattern CH2, with respect to the target location of subject P, separate roughly the same the distance configuration first test pattern CH1 and the second test pattern CH2.In addition, position about the first test pattern CH1 and the second test pattern CH2, can try to achieve according to following mode respectively: calculate MTF according to optical information such as the focal length of condenser lens 3 and F values in advance, the MTF that calculates is equated, in addition, also can use adjusted lens to try to achieve in the mode of experiment.
Specifically, shown in Fig. 1 (b), mobile focusing lens 3 on the optical axis directions X, respectively at the first test pattern CH1 and the second test pattern CH2, amount of movement corresponding to condenser lens 3, obtain the focus evaluated value of the shooting pattern of imaging on imaging apparatus 5, and set the position of condenser lens 3, so that the focus evaluated value of the first test pattern CH1 is consistent with the focus evaluated value of the second test pattern CH2.
Next, as shown in Figure 2, have in the camera head 1 with inferior parts: front lens 2; Condenser lens 3; The light filter of the reflected light of removing harmful infrared ray and being harmful to etc. (infrared ray is removed light filter or optical filter) 4; Imaging apparatus (CCD:Charge Coupled Devices: charge-coupled device (CCD)) 5; AFE (Analog Front End: AFE (analog front end)) 6, it will be converted into data image signal C and output from the analog picture signal of imaging apparatus 5 outputs; TG (TimingGenerator: timing pulse generator) 13, it utilizes predetermined periodic Control imaging apparatus 5 and AFE 6; Focus on drive division 12, its slip of carrying out the optical axis direction of condenser lens 3 drives; And focus detection portion 10, it detects the slippage of condenser lens 3 by sensor 11.
Imaging apparatus 5 constitutes by being set up in parallel a plurality of photo-electric conversion elements, and constitutes: at each photo-electric conversion element, image pickup signal S is carried out opto-electronic conversion and exports analog picture signal.
AFE 6 is by constituting with inferior parts: and correlated double sampling circuit (CDS:CorelatedDouble Sampling: the correlated double sampling) 7, it removes the noise by the analog picture signal of imaging apparatus 5 outputs; Variable gain amplifier (AGC:Automatic Gain Control: automatic gain control) 8, its amplification utilizes correlated double sampling circuit 7 to carry out the picture signal of correlated double sampling; And A/D converter 9, it will convert data image signal to by the analog picture signal from imaging apparatus 5 that variable gain amplifier 8 is imported.AFE 6 utilizes predetermined sampling frequency to convert data image signal to from the picture signal of imaging apparatus 5 outputs, and outputs to focus-regulating device 15.
Focus-regulating device 15 has with inferior parts: MTF operational part 16, and it is handled from the data image signal C union first test pattern CH1 of camera head 1 output and the MTF of the shooting pattern the second test pattern CH2; MTF comparing section 25, whether the mtf value of its comparison first test pattern CH1 and the mtf value of the second test pattern CH2 be consistent; ROM (Read Only Memory: ROM (read-only memory)) 23; CPU (Central Processing Unit: CPU (central processing unit)) 24; Impact damper 26, its interim storage is from the view data of AFE 6 outputs.CPU 24 controls each processing of focus-regulating device 15 according to the control program that is stored among the ROM23.
In addition, focus evaluated value of the present invention is brought into play its effect by MTF, and focus evaluated value detecting unit of the present invention is by 16 its effects of performance of MTF operational part.
In addition, MTF operational part 16 is made of second operational part 18 of the MTF of first operational part 17 of the MTF of the computing first test pattern CH1 and the computing second test pattern CH2.
Next, according to Fig. 3, the measuring method of the MTF of present embodiment is described.At first, when finding the solution MTF, make the first test pattern CH1 and the second test pattern CH2 be imaged on the imaging apparatus 5 output image data from AFE 6 (digital signal C) by condenser lens 3.
Then, shown in Fig. 3 (a), in first operational part 17 and second operational part 18, calculate number of samples according to the edge tilt angle of the shooting pattern of the first test pattern CH1 that is photographed and the second test pattern CH2, next, the number of samples that use calculates, scan image data is obtained the step response at edge thus to obtain pixel value, next, by step response is carried out differential, obtain the impulse response at edge, paired pulses response is carried out Fourier transform and is obtained MTF then.
Specifically, shown in Fig. 3 (a) and (b), at first, in number of samples calculating part 17a, 18a, calculate the edge tilt angle [alpha] among the first test pattern CH1 and the second test pattern CH2, calculate the number of samples P of base unit of the scanning of a direction becoming image.
Next, shown in Fig. 3 (c), a direction of image is made as main scanning direction, another direction is made as sub scanning direction (in the present embodiment, if vertical direction is a main scanning direction, horizontal direction is a sub scanning direction), the image that scanning is taken by imaging apparatus 5.At this moment, on main scanning direction, come scan image successively according to the mode of a line scanning number of samples P.Then, shown in Fig. 3 (d), like that,, obtain the step response at edge by obtaining the pixel value of each scanning position.
Shown in Fig. 3 (b), the edge of the shooting pattern of test pattern CH1, CH2 is made as vertical direction with main scanning direction, and sets number of samples P according to the mode of 1 pixel of edge line displacement in vertical direction during with respect to the vertical direction slight inclination.Fig. 3 (b) shooting is shown and view data, each and every one pixel of 1 in the square frame is shown, in the pixel ●, remarked pixel values such as ■, zero, mouth.
In addition, in the first figure CH1, show the edge across view data, left side brightness is darker, and right side brightness is brighter; In the second figure CH2, with the first figure symmetric formulation, show across the edge, right side brightness is darker, and left side brightness is brighter.
In addition, when finding the solution tilt angle alpha, shown in Fig. 3 (e),, S window w is set on y direction (vertical direction) at the edge of the first test pattern CH1 and the second test pattern CH2.At this moment, establish 1 window and have a plurality of units key element on x direction (horizontal direction), the height of each unit key element has identical value with 1 pixel, and width is than 1 value that pixel is little.
Next, use (formula 1), in each window w, carry out second differential.
L
w(x)=2*P
w(x)-P
w(x-1)-P
w(x+1) (formula 1)
In (formula 1), P
w(x) be interior point (x, Ey of window w
w) in pixel value, L
w(x) be the second differential value of this point.In addition, point (x, Ey
w) be the position when 1 unit key element is made as scale of x coordinate and y coordinate, Ey
wBe equivalent to 1,2,3 among Fig. 3 (e) ..., S.
Next, in each window w, obtain second differential value L
w(x) maximal value Lmax
wWith minimum value Lmin
w, obtain the x coordinate Xmax of these points
w, Xmin
w, use (formula 2) to obtain the x coordinate Ex of the marginal point in the window w
w
Ex
w=(Xmin
W*| Lmax
w|+Xmax
W*| Lmin
w|)/(| Lmax
w|+| Lmin
w|) (formula 2)
Next, obtain the tilt angle alpha of the edge line of the edge point group that from (formula 2), draws, the cot α round values that obtains that rounds up of this moment is made as number of samples P.
Next, transfer to step response calculating part 17b, 18b, shown in Fig. 3 (c), at first, vertically scan the first row pixel according to number of samples P, after the 1st column scan finishes, motion scan position in the horizontal direction, vertically scan vertically every successively number of samples ground scan image data once more according to number of samples P.
Next, shown in Fig. 3 (d), the pixel value of each scanning position is arranged on monobasic ground, obtains the step response at edge.In Fig. 3 (d), the longitudinal axis is represented brightness value, the position when transverse axis is represented each scanning position monobasic expansion.That is, in step response calculating part 17b, 18b, near the pixel value the scanning edge, vertically every scanning number of samples P ground according to the series arrangement pixel value of scanning, can obtain the step response at edge.
Next, transfer to impulse response calculating part 17c, 18c,, convert impulse response to by the step response that is obtained by step response calculating part 17b, 18b is carried out differential.The differential that carries out can be undertaken by the difference between the neighbor of for example getting step response herein.
Next, transfer to MTF calculating part 17d, 18d, obtain MTF by Fourier transform is carried out in the impulse response of being obtained by impulse response calculating part 17c, 18c.At this moment,, can obtain the real part and the imaginary part of each frequency, this real part and imaginary part addition are obtained MTF by Fourier transform.In addition, the computing method about MTF are not limited thereto, and also can use for example described resolution measurement method of ISO12233.
Next, with reference to Fig. 4, the step when using the first test pattern CH1 and the second test pattern CH2 that the focusing position of obtaining condenser lens 3 is described.This step gives each function portion command signal by CPU 24 according to the program among the ROM23 of being kept at and carries out.In addition, the S among Fig. 4 represents step.
At first, this step begins when operator's focusing regulating device 15 input initiating signals.
Next, in S101, make condenser lens 3 move to predetermined primary position, transfer to S102.
Next, in S102, begin the photography of the first test pattern CH1 and the second test pattern CH2, in S103, to the view data of focus-regulating device 15 outputs by AFE 6 outputs.
Next, in S104, in first operational part 17, obtain the MTF of the shooting pattern among the first test pattern CH1, and in second operational part 18, obtain the MTF of the shooting pattern among the second test pattern CH2, after this, transfer to S105 by computing by computing.
Next, in S105, calculate the MTF of the preset frequency that calculates by first operational part 17 and the MTF of the preset frequency that calculates by second operational part 18 between poor, transfer to S106 then.At this moment, because MTF can calculate according to each frequency component, compare and the corresponding MTF of predefined high frequency frequency component so need only.
Next, in S106, relatively MTF that calculates by first operational part 17 and the MTF that calculates by second operational part 18, whether the difference of judging both is 0 (whether the MTF that the so-called judgement shooting first test pattern CH1 obtains is consistent with the MTF that the shooting second test pattern CH2 obtains), in S106, when both differences are 0 (being), think that condenser lens 3 is in focusing position and finishes this processing; When both differences are not 0 (denying), transfer to S107.
Next, in S107, with scheduled volume mobile focusing lens 3, repeatable operation S103 is to S106 then along optical axis X, is to finish this processing at 0 o'clock up to both differences in S106.
As mentioned above, according to focus adjusting method and the focus-regulating device in the described camera head 1 of embodiment, the first test pattern CH1 and the second test pattern CH2 with the white of being divided into and black shooting pattern set in target location across subject P in the front and back of optical axis X, condenser lens 3 is moved on the optical axis directions X, respectively at the first test pattern CH1 and the second test pattern CH2, amount of movement corresponding to condenser lens 3, obtain the MTF of the shooting pattern of imaging on imaging apparatus 5, and the position of setting condenser lens 3, so that the MTF among the first test pattern CH1 is consistent with the MTF among the second test pattern CH2, therefore, even the peak point of focus evaluated value is unclear, also focusing position can be regulated accurately, and its adjusting can be easily carried out.
In addition, according to focus adjusting method and the focus-regulating device in the described camera head 1 of embodiments of the invention, can be simultaneously make a video recording the processing ease that focal adjustments is used and can detect the focusing position of condenser lens 3 accurately to the first test pattern CH1 and the second test pattern CH2 that separates along optical axis X.
More than, one embodiment of the present of invention have been described, but have the invention is not restricted to the foregoing description, can take variety of way.
For example, as shown in Figure 5, in the first test pattern CH1 and the second test pattern CH2, also can possess a plurality of shooting patterns respectively with sloping edge.Thus, be that odd number is compared with the shooting pattern, The noise can be reduced and focus evaluated value can be obtained accurately.And, by at a plurality of shooting patterns of a plurality of position configuration, can set focal position in the image according to purposes, can improve added value.
In addition, in the present embodiment, be that 0 position is made as focusing position with the difference between the mtf value of the mtf value of the first test pattern CH1 and the second test pattern CH2, but also can replace 0, when arriving the scope of predefined predetermined value, be made as focusing position.
In addition, in the present embodiment, used figure, but also can use and have other color the figure of (for example redness, green, blueness), specific color component has been carried out focal adjustment with white and shooting pattern of black.
In addition, put down in writing the camera head of the so-called auto-focus function of drive division 12 (electronic) in the present embodiment with condenser lens 3, but the invention is not restricted to possess the camera head of auto-focus function, also be applicable to the camera head of the position that utilizes manual adjustments condenser lens 3.And also can for example screw togather condenser lens 3 along optical axis X this moment makes its screw fixed at focusing position.
In addition, the present invention is applicable to also can uses the present invention to obtain the focusing of condenser lens 3 when having self-focusing camera head, it is stored among the ROM 23 as self-focusing parameter.
Claims (7)
1. the focus adjusting method in the camera head, this camera head has used pick-up lens and imaging apparatus,
Above-mentioned pick-up lens guides to above-mentioned imaging apparatus with shot object image;
Above-mentioned imaging apparatus carries out opto-electronic conversion to the above-mentioned shot object image by above-mentioned pick-up lens guiding, and output image signal;
This focus adjusting method moves above-mentioned pick-up lens along the optical axis that connects above-mentioned subject and above-mentioned imaging apparatus in above-mentioned camera head, the above-mentioned shot object image that is directed to above-mentioned imaging apparatus focused,
This focus adjusting method is characterised in that,
On above-mentioned optical axis, set first test pattern and second test pattern of shooting pattern in front and back across the target location of above-mentioned subject with the white of being divided into and black;
On above-mentioned optical axis direction, move above-mentioned pick-up lens, and respectively at above-mentioned first test pattern and second test pattern, obtain the focus evaluated value of the above-mentioned shooting pattern of imaging on above-mentioned imaging apparatus accordingly with the amount of movement of above-mentioned pick-up lens;
Set the position of above-mentioned pick-up lens, so that the focus evaluated value of above-mentioned first test pattern is consistent with the focus evaluated value of above-mentioned second test pattern.
2. the focus adjusting method in the camera head according to claim 1 is characterized in that,
Across with the cross line of above-mentioned light shaft positive cross, above-mentioned first test pattern of balanced configuration and above-mentioned second test pattern, and be configured to the position that does not overlap respectively.
3. according to the focus adjusting method in claim 1 or the described camera head of claim 2, it is characterized in that,
Above-mentioned focus evaluated value is the index of spatial frequency composition amount of the marginal portion of the above-mentioned shooting pattern of expression.
4. the focus adjusting method in the camera head according to claim 1 is characterized in that,
In above-mentioned first test pattern and second test pattern, a plurality of above-mentioned shooting patterns have been set up in parallel.
5. the focus-regulating device in the camera head, base has;
Pick-up lens, it guides to imaging apparatus with shot object image;
Imaging apparatus, it carries out opto-electronic conversion to the shot object image by above-mentioned pick-up lens guiding, exports the picture signal of a plurality of colors; And
The focus evaluated value detecting unit, the amount of movement of itself and above-mentioned pick-up lens detects the focus evaluated value of the above-mentioned shot object image of imaging on above-mentioned imaging apparatus accordingly;
Focus-regulating device basis in this camera head is set to the precalculated position by the detected testing result of above-mentioned focus evaluated value detecting unit with above-mentioned pick-up lens,
This focus-regulating device is characterised in that,
Along above-mentioned optical axis, set first test pattern and second test pattern of shooting pattern in front and back across the target location of above-mentioned subject with the white of being divided into and black;
Above-mentioned focus evaluated value detecting unit is respectively at above-mentioned first test pattern and second test pattern, obtains the focus evaluated value of the above-mentioned shooting pattern of imaging on above-mentioned imaging apparatus accordingly with the amount of movement of above-mentioned pick-up lens;
Set the position of above-mentioned pick-up lens, so that the focus evaluated value of above-mentioned first test pattern is consistent with the focus evaluated value of above-mentioned second test pattern.
6. the focus-regulating device in the camera head according to claim 5 is characterized in that,
Across with the cross line of above-mentioned light shaft positive cross, symmetry constitutes above-mentioned first test pattern and second test pattern, and constitutes respectively and do not overlap.
7. according to the focus-regulating device in claim 5 or the described camera head of claim 6, it is characterized in that,
Above-mentioned focus evaluated value is the index of spatial frequency composition amount of the marginal portion of the above-mentioned shooting pattern of expression.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2007072242A JP4549362B2 (en) | 2007-03-20 | 2007-03-20 | Focus adjustment method in imaging apparatus |
| JP2007-072242 | 2007-03-20 |
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| Publication Number | Publication Date |
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| CN101271245A true CN101271245A (en) | 2008-09-24 |
| CN101271245B CN101271245B (en) | 2011-01-12 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN2008100867444A Expired - Fee Related CN101271245B (en) | 2007-03-20 | 2008-03-20 | Focal point adjusting method in imaging apparatus |
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| JP (1) | JP4549362B2 (en) |
| KR (1) | KR100991551B1 (en) |
| CN (1) | CN101271245B (en) |
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| WO (1) | WO2008114888A1 (en) |
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| CN102540404A (en) * | 2010-12-24 | 2012-07-04 | 佳能株式会社 | Focus adjusting apparatus and method |
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| CN102814874A (en) * | 2011-06-10 | 2012-12-12 | 株式会社迪思科 | Processing device |
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| CN102483511B (en) * | 2009-08-11 | 2014-11-12 | 乙太精密有限公司 | Method and device for aligning a lens with an optical system |
| CN104297896A (en) * | 2014-09-01 | 2015-01-21 | 联想(北京)有限公司 | Focusing method and electronic equipment |
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| KR101113129B1 (en) * | 2010-10-25 | 2012-02-15 | 삼성전기주식회사 | Focusing method for camera module and image capturing device |
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| JP2678457B2 (en) * | 1988-03-16 | 1997-11-17 | 旭光学工業株式会社 | Focus position detection method |
| JPH0949965A (en) * | 1995-08-08 | 1997-02-18 | Nikon Corp | Focal position detector |
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- 2008-03-19 WO PCT/JP2008/055802 patent/WO2008114888A1/en active Application Filing
- 2008-03-19 KR KR1020097021810A patent/KR100991551B1/en not_active IP Right Cessation
- 2008-03-20 TW TW097109967A patent/TW200839342A/en unknown
- 2008-03-20 CN CN2008100867444A patent/CN101271245B/en not_active Expired - Fee Related
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Also Published As
| Publication number | Publication date |
|---|---|
| KR20090125184A (en) | 2009-12-03 |
| TW200839342A (en) | 2008-10-01 |
| KR100991551B1 (en) | 2010-11-04 |
| JP2008233481A (en) | 2008-10-02 |
| JP4549362B2 (en) | 2010-09-22 |
| CN101271245B (en) | 2011-01-12 |
| WO2008114888A1 (en) | 2008-09-25 |
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