CN1430049A - Delineating performance testing device, method and camera testing by the method - Google Patents

Abstract

The invention provides a camera lens representation performance-inspecting apparatus for inspecting the representation performance of a camera lens in a state close to actual photographing. In a camera lens representation performance-inspecting apparatus 10, the chart image of a chart unit 5 obtained by actually opening or closing a shutter by a lens mirror cylinder 50 in a camera 6 is converted to an imaging signal by an imaging device 13 and is captured by a CPU 21. Further, the MTF value of the chart image is calculated by an MTF arithmetic section 22, and the representation performance of a photographing lens is discriminated based on the MTF value. Since the chart image is an image close to an actual photographing including image deviation due to the shock or a drive section when opening/closing the shutter or the like, the representation property can be discriminated in a state close to a state where the camera is used for an actual inspection according to the inspection result of the representation performance of the imaging lens, thus inspecting the representation performance of the extremely practical lens.

Description

The camera of drawing performance checking device, method and utilizing this method to check

Technical field

The present invention relates to a kind of check optical instruments such as camera draw performance draw the performance checking device.

Background technology

The testing fixture of the resolution characteristic of the photographic lens of existing inspection camera, be a kind of actual photography of picture to be contained on the film in the camera, observe the sheet number of picture on the film after developing, judge the resolution characteristic testing fixture according to photographs of resolving power.

In addition, also has a kind of existing testing fixture according to MTF as the resolution characteristic testing fixture.This testing fixture makes the stable picture that obtains by photographic lens go up imaging at shooting part (CCD), calculates MTF (the Modulation Transfer Function modulation transfer function) value of the shooting of this moment, checks the focus state of photographic lens.And the picture of aforementioned stable is the picture that obtains under the shutter state of remaining on out of photograph pusher side.

But, in the testing fixture of above-mentioned existing resolution characteristic according to photographs, when the picture sheet of the picture on the film of observing after developing is counted, it is constant that imaging concentration is difficult to reach, and, there is deviation owing to the naked eye observe, thereby can not correctly reads picture sheet number, be difficult to carry out high-precision resolution characteristic inspection.

And, in the another kind of existing testing fixture, because need check, so may be different with the photography state of reality by resulting picture under the steady state (SS) when above-mentioned maintenance shutter is out state according to MTF.That is, owing to can shake owing to the action of switch shutter during actual photography, the perhaps influence of shutter opening waveform etc. can't show in the mtf value of exposure of aforementioned stable.So, the check result of drawing performance of camera lens in the time of actual photography can occurring obtaining.

Summary of the invention

Therefore, in view of the above problems, the purpose of this invention is to provide a kind of can correctly check with the resolution characteristic of the optical instrument of actual photography state equivalence draw the performance checking device.

For addressing the above problem, first invention draw the performance checking device, be used to check the shutter with photographic lens and this photographic lens light path of switch optical instrument draw performance, this testing fixture is characterised in that to have: at the picture that is provided with apart from above-mentioned camera predetermined distance place, describe to check the usefulness pattern; The shooting part of above-mentioned pattern being made a video recording by above-mentioned photographic lens; Control the imaging control part of the shooting action of above-mentioned shooting part; Calculate the MTF operational part of MTF based on the output of above-mentioned shooting part; Control the shutter release control part of above-mentioned shutter release action, the above-mentioned shooting of the related control with above-mentioned shutter action of above-mentioned control assembly is moved, and estimates the performance of drawing of above-mentioned optical instrument based on the output of at that time MT reconnaissance F operational part.

The performance checking device of drawing of second invention has: shooting part, make a video recording by the photographic optical system that is configured in assigned position as the camera of checked property; Picture, describing the pattern of regulation and being configured in the opposition side that disposes above-mentioned shooting part one side has predetermined distance apart from above-mentioned camera; MTF calculates parts, the picture of taking the photograph based on above-mentioned shooting part, calculate MTF characteristic as the photographic optical system of the camera of above-mentioned checked property, this is drawn the performance checking device and is characterised in that, have and be configured between above-mentioned picture and the shooting part, the shutter part of the light path of switch from above-mentioned picture to photographic unit, MT reconnaissance F calculates parts based on comprising starting the stipulated time of doing or closing the start-up time of at least one side in the action of above-mentioned shutter part, the data that above-mentioned photographic unit is taken the photograph are calculated the MTF characteristic of the photographic optical system of above-mentioned camera.

The performance checking method of drawing of the 3rd invention, be used to check have photographic lens, the optical instrument of the shutter of this photographic lens light path of switch draw performance, it is characterized in that, comprised the following steps: for the 1st step, by above-mentioned photographic lens, to be provided with apart from above-mentioned camera predetermined distance place, describe to check that the picture with pattern begins to make a video recording; In the 2nd step, open above-mentioned shutter; In the 3rd step, close above-mentioned shutter; In the 4th step, finish above-mentioned shooting action; In the 5th step, calculate the MTF characteristic based on the data that above-mentioned the 1st step was made a video recording to the 4th step; In the 6th step,, estimate the performance of drawing of above-mentioned optical instrument based on the output in above-mentioned the 5th step.

The camera of the 4th invention is characterised in that, checks by the performance checking method of drawing of above-mentioned the 3rd invention.

Description of drawings

Fig. 1 be the embodiment of the invention camera lens draw in the performance checking device longitudinal section of the lens barrel of being installed on the camera as checked property.

Fig. 2 is the decomposition diagram that is assembled in the shutter device in the lens barrel of above-mentioned Fig. 1.

Fig. 3 is the A-A sectional view of shutter device Fig. 1 under in off position that the lens barrel of Fig. 1 is shown.

Fig. 4 is the A-A sectional view of shutter device Fig. 1 under little aperture state that the lens barrel of Fig. 1 is shown.

Fig. 5 is the A-A sectional view of shutter device Fig. 1 under open mode that the lens barrel of Fig. 1 is shown.

Fig. 6 is the system diagram that illustrates as the formation of the camera lens characteristic check of drawing the performance checking device of one embodiment of the invention.

Fig. 7 is the square frame pie graph of formation of MTF characteristic check device that the embodiment of above-mentioned Fig. 6 is shown.

Fig. 8 is that the optical axis center mtf value is with respect to the variation line chart of Z position in the MTF characteristic check device of an embodiment of above-mentioned Fig. 6.

Fig. 9 is that peripheral mtf value is with respect to the variation line chart of Z position in the MTF characteristic check device of an embodiment of above-mentioned Fig. 6.

Figure 10 is in the MTF characteristic check device of an embodiment of above-mentioned Fig. 6, and MTF checks the process flow diagram of handling.

Figure 11 illustrates in the MTF characteristic check device of an embodiment of above-mentioned Fig. 6, the line chart of one example of the measurement result of the mtf value of each picture, Figure 11 (A) is the line chart of the optical axis center mtf value of center picture, Figure 11 is that (B) is the line chart of peripheral mtf value of the picture of first quartile, Figure 11 (C) is the line chart of peripheral mtf value of the picture of the 2nd quadrant, Figure 11 (D) is the line chart of peripheral mtf value of the picture of the 3rd quadrant, and Figure 11 (E) is the line chart of peripheral mtf value of the picture of the 4th quadrant.

Figure 12 is in the MTF characteristic check device of an embodiment of above-mentioned Fig. 6, and shutter opens and closes the time diagram of the image pickup signal of signal and camera.

Embodiment

Following with reference to accompanying drawing, embodiments of the invention are described.

Before the MTF testing fixture of explanation, earlier the structure as the lens barrel of installing in the camera by the checked property of above-mentioned testing fixture inspection (camera lens) is described as the camera lens of drawing the performance checking device of the camera lens of the embodiment of the invention.

Fig. 1 is the longitudinal section of the remote state of said lens lens barrel.Fig. 2 is the decomposition diagram that is assembled in the shutter device in the said lens lens barrel.Fig. 3,4,5 is respectively the state that closes, the little aperture state of above-mentioned shutter device or the A-A sectional view of opening the Fig. 1 under the state fully.

Object one side with lens barrel is the place ahead in the following description, is the rear with imaging surface one side.

Said lens lens barrel 50 is mounted in the camera lens in the roll film camera, has as shown in Figure 1: the fixed mount 51 that is fixed on the main body side of camera 6 (Fig. 6) by main body fixed part 78; Can rotate freely, be supported on with advancing and retreat the swivel mount 52 on the fixed mount 51 with respect to fixed mount 51; Be rotated restriction, directly advance guide frame 73 by fixed mount 51 with swivel mount 52 is advanced and retreat simultaneously; Be fixedly supported on the 1st gang fight 54 on the zoom frame 53, this zoom frame 53 is by supported with respect to swivel mount 52 ground of can advancing and retreat under by the state that directly advances guide frame 73 and aftermentioned the 2nd gang fight 55 restriction rotations; The 2nd gang fight 55 by 53 supports of zoom frame; The shutter device of installing in the 2nd gang fight 55 74 as shutter part; By the 1st lens group 75 that supports as the 1st gang fight 54 of the photographic optical system of this lens barrel and the 2nd lens group 76 that supports by the 2nd gang fight 55.And the lens axis of above-mentioned photographic optical system is optical axis Oc.

Said fixing frame 51 is pipes, is fixedly supported on the main body fixed part 78, and interior perimembranous is provided with internal thread 51a and parallel with optical axis Oc directly advances keyway 51b.

Above-mentioned swivel mount 52 is pipes, and the end side end is provided with external thread 52d, and 3 location of inner peripheral surface respectively are provided with 2 cam path 52a, 52b, and the inner peripheral surface terminal part is provided with internal circle groove 52e.In above-mentioned 2 cam paths, cam path 52a is used to drive zoom frame advance and retreat, and cam path 52b is used to drive the 2nd gang fight advance and retreat.Because the internal thread 51a of above-mentioned external thread 52d and fixed mount 51 is spirally connected, so swivel mount 52 is advanced and retreat while rotate when being driven by not shown swivel mount drive division rotation.

Above-mentioned directly to advance guide frame 73 are annular elements, are provided with: the 73a of direction protrusion portion that protrudes in the substrate peripheral part; In substrate perimembranous forwards outside the outstanding bayonet claw 73b of lateral buckling; Perimembranous is directly advanced guide part 73c along optical axis Oc is extended forward in the substrate.Above-mentioned guiding projection 73a embeds directly advancing among the keyway 51b of fixed mount 51 with being free to slide.Above-mentioned bayonet claw 73b freely slides and embeds among the internal circle groove 52e of swivel mount 52.So the driving in case swivel mount 52 is rotated, advances and retreat is directly advanced guide frame 73 and is not just rotated, but directly advances mobile with swivel mount 52 along the direction of optical axis Oc.

Above-mentioned zoom frame 53 is pipes, embeds the interior week of swivel mount 52 with states rotatable, advance and retreat.On the peripheral part of zoom frame 53, be fixed with 3 groups of cam followers 59 by its axial region.And, be fixed with the 1st gang fight 54 of supporting the 1st lens group 75 on the front opening part 53a of zoom frame 53, be provided with 3 in the interior perimembranous upper edge of zoom frame 53 optical axis Oc direction and directly advance gathering sill 53b.

Above-mentioned cam follower 59 engages with the cam path 52a of swivel mount 52 with being free to slide.And 3 of aftermentioned the 2nd gang fight 55 directly advance guide finger 55b and embed above-mentionedly directly to advance among the gathering sill 53b with being free to slide.Therefore, when swivel mount 52 rotations, zoom frame 53 drives along optical axis Oc direction advance and retreat directly being advanced under the state of guide finger 55b restriction rotation to pass through cam path 52a and cam follower 59.

Above-mentioned the 2nd gang fight 55 is circular ring parts, with the state configuration that can the advance and retreat interior week at zoom frame 53.Be equiped with 3 cam followers 60 by its axial region on the peripheral part of the 2nd gang fight 55.The butting section 60b radially of these 3 cam followers 60 is entrenched on the inner peripheral surface of zoom frame 53, determines the optical axis position of the 2nd gang fight 55.

In the 2nd gang fight 55, be provided with the ditch 55a and of directly advancing to lead as directly advancing guide finger 55b to 3 of the jut of exterior protrusions along optical axis Oc.And all peristomes support the 2nd lens group 76 in it.The guide part 73c that directly advances that directly advances guide frame 73 embeds the above-mentioned gathering sill 55a that directly advances with being free to slide.

Above-mentioned cam follower 60 connects the side face peristome of zoom frame 53, embeds among the cam path 52b of swivel mount 52 with being free to slide.Therefore, the 2nd gang fight 55 is directly being advanced under the state of guide frame 73 restriction rotations, and directly being advanced and retreat by cam path 52b drives.

Between the place ahead internal face of the front face of above-mentioned the 2nd gang fight 55 and zoom frame 53, for to the 2nd gang fight 55 application of force and dispose force application spring 56 rearward.

Above-mentioned shutter device 74 has as shown in Fig. 1 and Fig. 2: the fast door frame 57 with fixed aperture opening 57a; 3 blades 61,62,63 as the shutter part that can open and close rotation; Drive the release lever 64 that blade is used; The shutter that the release lever rotation urging is used leaves spring 65; Push vane plate 58; The shutter release electromagnet apparatus 66 that is used for the switch shutter as drive source.

Above-mentioned fast door frame 57 fixed configurations are provided with in this fast door frame 57 in the place ahead of the 2nd gang fight 55: the fixed aperture opening 57a that is provided with the unlimited aperture of supplying with light path of photography at central portion; Tu Chu release lever back shaft 57b rearward; Tu Chu 2 blade supporting pin 57c, 57d forwards; Be configured in the through hole 57e that shutter drive pin between above-mentioned supporting pin 57c, the 57d, release lever 64 runs through.

Above-mentioned release lever 64 is provided with: axis hole 64a; Vane drive pin 64b; Plunger butting section 64c; Spring is against pin 64d.Above-mentioned release lever 64 is supported on the rear of fast door frame 57 free to rotately by release lever back shaft 57b via axis hole 64a.Under this holding state, shutter drive pin 64b runs through the pin through hole 57e of fast door frame 57, embeds driving pin-and- hole 61b, 62b, the 63b of aftermentioned blade 61,62,63.Above-mentioned release lever 64 by with spring against pin 64d against shutter open spring 65, by the application of force along the counter clockwise direction rotation (from object one side) of opening direction as shutter.

Be respectively equipped with on the above-mentioned blade 61,62,63 and support pin-and- hole 61a, 62a, 63a and driving pin-and-hole (slotted hole) 61b, 62b, 63b.In the above-mentioned blade 61,62,63, blade 61 is identical with 63 shapes, is that the center roughly is the left-right symmetric shape with respect to blade 62 with optical axis Oc.And, under the state of blade 61 and blade 63 clamping blades 62, blade 61,62,63 with embed respectively on the blade supporting pin 57c of fast door frame 57 or the 57d support pin-and- hole 61a, 63a or 62a state by support with rotating freely, and the state of pushing with the vane plate 58 that is pressed is mounted.This installation site is between the 2nd lens group 76 of the 1st lens group 75 of the 1st gang fight 54 and the 2nd gang fight 55.

Above-mentioned shutter release uses electromagnet apparatus 66 shown in Fig. 2,3, it is the plunger type DC electromagnet device that is provided with movable core, this movable core has the meander coil portion that profile is a circular shape, and this electromagnet apparatus is provided with: be wound on the above-mentioned meander coil portion 67 on the crooked reel 68; Along the yoke portion 69 of above-mentioned meander coil portion 67 magnetic force in conjunction with leading section and terminal part; Can in above-mentioned reel 68, stretch out the plunger 71 that indentation ground supports in the outgoing side end as movable core; Secured core 70; To the plunger spring 72 of above-mentioned plunger 71 to the outstanding side application of force.The front end butting section 64c of above-mentioned release lever 64 since shutter open spring 65 the application of force and always with the front end of above-mentioned plunger 71 against.

So, being under the off status at the driving voltage of the coil portion 67 of above-mentioned electromagnet apparatus 66, plunger 71 is by because shutter is opened the application of force of the strong plunger spring 72 that the application of force of spring 65 produces, and is in extrusion position.Under this state, as shown in Figure 3, release lever 64 rotates ormal weight along clockwise direction.So respectively to the counter clockwise direction as closing direction, perhaps clockwise direction is rotated by release lever 64 for blade 61,63 and blade 62, closes the fixed aperture opening 57a of fast door frame 57.

And, when on the coil portion 67 of above-mentioned electromagnet apparatus 66, applying driving voltage, plunger 71 since the magnetic force that is produced on the coil 67 be attracted to secured core 70 against the position on.Follow the attraction of plunger 71, release lever 64 leaves at shutter under the application of force of spring 65 and rotates counterclockwise, until with not shown retainer against assigned position.As shown in Figure 5, blade 61,63 and blade 62 respectively to as evolution to clockwise direction, perhaps rotate counterclockwise, the fixed aperture opening 57a of fast door frame 57 is in full-gear.In the action of the opening full-gear of the opening closed condition from Fig. 3 in Fig. 5, the little aperture openings state through as shown in Figure 4 is changed to above-mentioned full-gear.

In order to utilize said lens lens barrel 50 to photograph with above-mentioned formation, reach photographic remote position to zoom frame the 53, the 1st gang fight the 54, the 2nd gang fight 55 etc. from telescopic location, need to drive turret 52 and be rotated.When directly being advanced guiding by directly advancing guide frame 73, driven, for example can pass out to photographic remote position shown in Figure 1 by cam follower 59,60 by this rotation zoom frame 53 and the 1st gang fight 54 and the 2nd gang fight 55.

When the lens barrel 50 under above-mentioned photography state is carried out exposure, in case on the coil portion 67 of shutter release, apply driving voltage with electromagnet apparatus 66, attract plunger 71, blade 61,63 and 62 will rotate to opening direction, the fixed aperture opening is opened, and shutter is in open mode.After shutter time second through regulation, the driving voltage on the above-mentioned coil portion 67 is closed, and plunger 71 is outstanding again, and blade 61,63 and 62 is driven and turns to above-mentioned opening off-position, end exposure.Such camera for example according to measuring to the output of the distance member of the distance of subject, moves along optical axis direction by the regulation lens with lens barrel 50 in actual use, finishes to focus on action.And, be used for the lens displacement amount that this focusing is moved, since the deviation of parts etc., the displacement difference of different lens barrels 50.Therefore, at each lens barrel 50, will be kept in the camera as adjusted value with respect to the camera lens displacement of the regulation of predetermined distance.

Though the MTF characteristic check device 10 (Fig. 6) of said lens lens barrel 50 by the aftermentioned camera lens checked the performance of drawing of camera lens, suppose that the focal position of the photographic position of the 1st lens group the 75, the 2nd lens group 76 is adjusted before inspection.

Below, to formation, wait with Fig. 6,7 to describe as the MTF characteristic check device of drawing the performance checking device of the camera lens of one embodiment of the invention.

Fig. 6 is the system diagram of the formation of expression MT reconnaissance F characteristic check device 10.Fig. 7 is the square frame pie graph of the formation of expression MT reconnaissance F characteristic check device 10.And, constituting in the image pickup part 1 (aftermentioned) of MTF characteristic check device 10 of present embodiment, the direction parallel with photographic lens optical axis Oc and shooting optical axis Od is the Z direction, and in the direction of Z direction quadrature, left and right directions is a directions X, and above-below direction is the Y direction.

In above-mentioned camera 6, usually because the scale error and the assembly error of the component parts of mirror holder, for example: the signal-lens RDN (shape of face, thickness, refractive index), each lens interval, off-centre etc. cause drawing Effect on Performance, simultaneously, during actual photography, because the influence of generations such as focal position and image fog even the comprehensive performance of drawing is changed.This MTF characteristic check device is based on the above-mentioned comprehensive camera data of drawing performance that obtains under approaching actual photography state, as opinion scale to photographs, by with the corresponding mtf value of actual photographed, evaluation is judged the quality of camera lens as the performance of drawing of the lens of the camera 6 of checked property.

The lens barrel 50 of above-mentioned camera 6, when on-off shutter, owing to the plunger 71 with certain mass is attracted to open mobile at a high speed, the 2nd gang fight 55 is impacted.So the 2nd lens group 76 that is kept by the 2nd gang fight 55 shakes in exposure sometimes, produce image blurring on the imaging surface, the performance of drawing of lens is produced ill effect.This MTF characteristic check device 10 is except the error of the component parts of consideration mirror holder, and the above-mentioned image blurring influence of also special consideration is checked.

In the MT reconnaissance F characteristic check device 10, photogra utilizes picture element unit cell 5, by the camera data of camera data on the photographic lens optical axis Oc at picture picture center and picture picture periphery, computing is as each mtf value of MTF characteristic, with this mtf value compare with the check criteria value judge whether qualified.

MT reconnaissance F characteristic check device 10 as shown in Fig. 6,7, is made up of image pickup part 1, MTF mensuration control part 2, keyboard 3, monitor 4, picture element unit cell 5.Camera 6 as checked property is installed on the image pickup part main part 18 of image pickup part 1.

As shown in Fig. 6,7, above-mentioned image pickup part 1 comprises camera 11, the imaging control part 14 as the imaging control part part, webcam driver portion 15, the image pickup part main part 18 as shooting part.

Above-mentioned camera 11 is by the imaging lens system 12 with optical axis Od, form as the CCD of imaging apparatus and camera head 13 with shooting treatment circuit.Among the above-mentioned CCD, the picture picture that is taken into by the 1st, 2 lens groups 75,76 (lens barrel 50) of above-mentioned camera 6 is by imaging lens system 12 imaging on the imaging surface of CCD, and converts electric signal to by this CCD.Utilize the shooting output signal of the above-mentioned CCD of above-mentioned shooting processing circuit processes, acquired image data is output to the CPU21 side.

The CCD of imaging control part 14 drive controlling camera heads 13 and shooting treatment circuit.

XY axle on the image pickup part main body 18 drives platform (XY axle drive division) 16, the Z axle drives platform (Z axle drive division) 17 and forms by being assembled in above-mentioned webcam driver portion 15.On above-mentioned XY axle driving platform 16, be equiped with camera 11, drive this camera 11 to directions X and Y direction.And, on Z axle driving platform 17, above-mentioned XY axle is installed and drives platform 16, make above-mentioned camera 11 move by drive this XY axle driving platform 16 to the Z direction along the Z direction.

MT reconnaissance F measures control part 2 and is made up of the RAM portion 25 as the CPU21 that controls the control assembly of adjusting control part inside and above-mentioned image pickup part 1, storage arithmetic expression information etc.

Be provided with in the above-mentioned CPU21: the MTF operational part 22 of calculating parts as MTF; Focal position control part 23 sends the indication that photographic lens is passed out to the focal position to camera 6; Be used to control the shutter release control part 24 as the shutter control assembly of the shutter release of camera 6; To the imaging control part 14 output shooting beginnings of camera side, the imaging control part of end signal.

MT reconnaissance F operational part 22 is taken into by the picture image data by 13 outputs of above-mentioned camera head, obtains the mtf value of above-mentioned picture by computing, judges OK/NG (whether qualified judgement) according to this operation result.The driving to the focal position of camera 6 is carried out in control part 23 indications in above-mentioned focal position.

Keyboard 3 carries out the various settings when carrying out the MTF inspection, and monitor 4 is used for confirming that MTF checks the affirmation of the operating state of handling and the result who draws performance checking.

Above-mentioned picture element unit cell 5, it is standard photo distance L1 place as the subject distance of using when the common camera shooting, for example: the test picture on the photography picture frame that disposes on the position of distance 3m, it is provided with: be positioned at the 5a of center picture portion on the photographic lens optical axis Oc of camera 6; The 5b of neighboring picture portion of the first quartile on the photography picture frame peripheral position on XY plane; The 5c of neighboring picture portion of the 2nd quadrant; The 5d of neighboring picture portion of the 3rd quadrant; The 5e of neighboring picture portion of the 4th quadrant.And the prescribed distance that the above-mentioned center 5a of picture portion is directions X and Y direction (be made up of longitudinal direction pattern and transverse direction pattern by the pattern of spatial frequency f0=10 bar/mm).(pattern of spatial frequency f0=10 bar/mm) is formed by radiation direction (S direction) and the prescribed distance of Zhou Fangxiang (M direction) respectively in above-mentioned each neighboring picture portion.Why in MTF checks, adopt above-mentioned spatial frequency f0=10 bar/mm, be because this spatial frequency and aftermentioned more high spatial frequency f1, f2 etc. compare, camera picture is fine or not corresponding in the time of can be preferably with actual photographed.

Above-mentioned camera 6 is provided with: in be provided with the 1st lens group the 75, the 2nd lens group 76 of said lens optical axis Oc and the lens barrel 50 of shutter device 74; Be responsible for all control of camera and have the CPU31 of shutter control assembly; Drive the lens drive division 33 of above-mentioned photographic lens 75,76 advance and retreat; The drive control part 32 of control said lens drive division 33 under the control of CPU31; The drive control part 34 of electromagnet apparatus 66 is used in driving as the shutter release of the drive source of above-mentioned shutter device 74; The photographies such as focal position data of storage lens barrel 50 EEPROM35 of data.This camera 6 is installed on the above-mentioned image pickup part main body 18 with respect to the parallel state of shooting optical axis Od of the imaging lens system 12 of image pickup part 1 described later with the optical axis Oc that keeps lens barrel 50 when MTF check to handle.

Below, to measure carry out MTF by 10 pairs of cameras of MTF characteristic check device 6 with above-mentioned formation, processing such as the computing of mtf value action describes.

Camera 6 and webcam driver portion 15 are set to optical axis Oc, Od center, perhaps the drawing board of the picture periphery state of making a video recording.That is, camera 6 is installed on the image pickup part main body 18 of image pickup part 1 under the open mode at bonnet 80.At this moment, determine that the optical axis Oc of lens barrel 50 of above-mentioned camera 6 is consistent with the center of the 5a of center picture portion of picture element unit cell 5.After like this camera being set, before the shooting action of picture, the lens group of lens barrel 50 is sent the focal position with respect to above-mentioned standard photo distance L1.Aperture plane (film face) 79 position becomes the image space of picture thus.

The action of sending of the lens group of this moment both can be by the CPU31 transmitting range data from the CPU21 of MTF characteristic check device 10 to camera 6, carry out based on this range data, also can carry out based on the range data that the not shown distance member that has from camera 6 obtains.These can be when checking camera 6, according to being to estimate the performance of drawing that comprises distance member that camera has, still estimating and do not comprise that the performance of drawing of distance member carries out suitable selection.

When being taken into the picture (optical axis Oc center MTF mensuration) at optical axis Oc center, drive platform 16, make the optical axis Oc center of aperture plane 79 of the optical axis Od align cameras 6 of camera 11 (imaging lens system 12) by the XY axle that drives webcam driver portion 15.

When being taken into the picture (peripheral MTF measures) of photography picture frame periphery, drive platform 16 by driving above-mentioned XY axle, make the optical axis Od of camera 11 (imaging lens system 12) aim at the peripheral pattern image position of arbitrary quadrant in the 1st to the 4th quadrant of mensuration of the aperture plane 79 of carrying out camera 6.

Measure the MTF at optical axis Oc center, perhaps during the MTF of periphery, drive camera 11 along the Z direction, make the focus point of imaging lens system 12 consistent, the MTF of mensuration picture with aperture plane 79 by utilizing the Z axle to drive platform 17.At this moment, the position the focus point of above-mentioned camera 11 (imaging lens system 12) on aperture plane 79 time is made as Zd=0 as the differential location Zd of benchmark Z deviation of directivity amount (defocus amount), and this Zd=0 is corresponding with the imaging surface position of camera.And, the Z deviation of directivity position Zd when the rear (back side) of aperture plane 79 is made as+side, the Z deviation of directivity position Zd when (subject one side) is made as a side forwardly.

The focus point of camera 11 is when the differential location Zd=0 of above-mentioned Z direction, image by the center picture 5a that is taken in the lens barrel 50, perhaps image imaging on the imaging surface of CCD of neighboring picture (being the neighboring picture 5e of the 4th quadrant at this moment) is transformed to electric image pickup signal by CCD.The image pickup signal of above-mentioned picture is exported in the CPU21 side by camera head 13.Then, the mtf value by the above-mentioned picture of MTF operational part 22 computings.

Fig. 8 is the variation line chart of mtf value of image of the center picture portion 5a of focus point when the Z direction moves of above-mentioned camera 11 (imaging lens system 12).This line chart represents from the differential location Zd=0 on the aperture plane 79 to Z direction (optical axis direction)+side ,-variation of the mtf value of the picture of lateral deviation difference position.And among the figure, f0, the f1 of above-mentioned center picture portion, the curve of f2 be the variation of the mtf value of the vertical or transverse direction pattern of representation space frequency f 0=10 bar/mm, f1=20 bar/mm, f2=30 bar/mm respectively.

In the MTF of present embodiment characteristic check device 10, for example: the MTF data of the curve (solid line) of the spatial frequency f0=10 bar/mm of the longitudinal direction picture pattern that correspondence was the highest during the common subject of application was photographed during MTF checked.And the mean value of data that also can adopt longitudinal direction pattern and transverse direction pattern is as mtf value.

In the measurement result of above-mentioned Fig. 8, be extreme value with respect to the mtf value P0 at the image Zd=0.00mm place of the center picture 5a of portion.That is, on the indication window diametric plane 79 with the position consistency of mtf value extreme value.And at this moment, the mtf value that image surface (aperture plane) is located is 73%, and tentative standard value M is 70%, and it is qualified that the inspection by MTF operational part 22 is judged to be, and is expressed as " OK " on monitor.When other spatial frequency f1, f2=20,30/mm, the mtf value P0 ' of the Zd=0 of image surface, P0 " be respectively 42%, 22%.

Secondly, when measuring the MTF of photography picture frame periphery, for example in the peripheral MTF of the 4th quadrant measures, the XY axle that drives webcam driver portion 15 drives platform 16, make the optical axis Od of the imaging lens system 12 of camera 11 aim at aperture plane 79 on the picture position of the 5e of neighboring picture portion of the 4th quadrant of picture element unit cell 5, same with the mensuration at optical axis Oc center, consistent on the focus point that makes camera 11 and the aperture plane 79, measure MTF.

Fig. 9 is the variation line chart with respect to the mtf value of the image of the 5e of neighboring picture portion.And, among the figure, f0, the f1 of above-mentioned neighboring picture portion, the curve of f2 are represented the variation of the spatial frequency f0=10 bar/mm of picture, f1=20 bar/mm, f2=30 bar/mmH cun mtf value respectively, and solid line is represented the mtf value of S directional patterns, and dotted line is represented the mtf value of M directional patterns.In the MTF characteristic check device 10 of present embodiment, the variation of the mtf value of the curve (solid line) of the f0 when using the spatial frequency f0=10 bar of S direction picture pattern/mm.In the measurement result of above-mentioned Fig. 9, the mtf value P4 of departure Zd=0 is 60%, because surpass peripheral standard value M40%, check result is qualified.When other spatial frequency f1, f2=20,30/mm, mtf value P4 ', the P4 of image surface Zd=0 " be respectively 34%, 23%.

MTF characteristic check device 10 is that the MTF at center is determined too with the aperture plane (image surface) of the peripheral pattern of the 1st ~ the 3rd quadrant beyond the 4th quadrant when actual the inspection, estimates the mtf value of peripheral pattern according to this measurement result.

Below, action is handled in the inspection of MTF characteristic check device 10, use Figure 10,11,12 to specify.

Above-mentioned Figure 10 is the process flow diagram that above-mentioned inspection is handled.Figure 11 is the line chart of an example of measurement result of the mtf value of each picture of expression, the variation of the mtf value of Figure 11 (A) expression center picture 5a, the variation of the mtf value of the neighboring picture 5c of Figure 11 (B) expression the 1st quadrant, the variation of the mtf value of the neighboring picture 5c of Figure 11 (C) expression the 2nd quadrant, the variation of the mtf value of the neighboring picture 5d of Figure 11 (D) expression the 3rd quadrant, the variation of the mtf value of the neighboring picture 5e of Figure 11 (E) expression the 4th quadrant.And Figure 12 is the time diagram of the camera time of shutter release time of shutter device 74 and camera 11.

Fig. 8, curve f0, f1, f2 shown in Figure 9 are under the state of opening the shutter device 74 that camera 6 has, by camera 11 along the optical axis direction displacement time, is measured the family curve of the picture of the resulting spatial frequency of MTF characteristic.

Camera 6 is adjusted the sendout of the lens group of predetermined distance in advance based on the MTF family curve that obtains like this.By the MTF characteristic check device in the present embodiment 10 check camera lens draw performance the time, measure the MTF characteristic at the departure Zd=0 place of Z direction.

At first, MTF characteristic check device 10 and picture element unit cell 5 and camera 6 are set to MT reconnaissance F and measure state.That is, camera 6 is set on image pickup part main body 18, makes the optical axis Oc of lens barrel 50 consistent with the center of the 5a of center picture portion of picture element unit cell 5.And picture 5 is arranged on the standard photo distance L1 position of camera distance 6.Therefore, by the focal position control part 23 of MTF characteristic check device 10 sides, the CPU31 by camera 6 sides drives drive control part 32, lens barrel 50 is passed out on the focal position of standard photo distance L1.Under this was provided with state, the characteristic check of beginning Figure 10 was handled under the control of CPU21.

Before the shutter that begins from step S1 is opened processing, drive platform (XY axle drive division) 16 by the XY axle and make the optical axis Od of camera 11 aim at the optical axis Oc of said lens lens barrel 50, and become the shooting state of the picture that can take the 5a of center picture portion.Then, drive controlling Z axle drives platform (Z axle drive division) 17, along Z direction dollying head 11, makes the focusing of camera 11 consistent with the aperture plane 79 of camera 6.

In step S1, open the blade of the shutter device 74 of lens barrel 50, in step S2,, utilize camera 11 to be taken into the picture signal of the picture at optical axis Oc center in order to measure the MTF at optical axis Oc center.In step S3, close the shutter of shutter device 74.

In step S1, transmit the shutter release control data of regulation to the CPU31 of camera 6 from the shutter release control part 24 of MTF characteristic check device 10.

In step S2, to imaging control part 14 output shooting commencing signals, begin to begin shooting from step S3, and its value is carried out integration by camera 11 from the CPU21 of MTF characteristic check device 10.But in this stage, because closed the blade of the shutter device 74 of camera 6, actual integrated value does not change (reference time figure).

In step S4, from the CPU21 of above-mentioned shutter release control part 24 to camera 6, output is used to begin the release signal of the switch motion of shutter device 74.Based on this release signal, CPU21 outputs to shutter drive control part 34 based on the shutter release control data that transmits from shutter release control part 24 among the above-mentioned steps S1 with the shutter release signal.Then, this shutter release drive control part 34 attracts and makes shutter release outstanding with the plunger 71 of electromagnet apparatus 66, drives the switch (step S5, step S6) of blade 61,62,63.Along with the switch motion of this shutter, the integrated value of camera 11 begins to change.

Then, the CPU21 of MTF characteristic check device 10 with the shutter close signal of response from above-mentioned CPU31 output, to stop shooting, stops shooting to imaging control part 14 output shooting stop signals in step S7.Integration data according to above-mentioned shooting is sent to MTF operational part 22.At this moment, because finish to exist the delay of t0 time from the output shutter close signal to the closing motion of practical shutters, so consider time delay, output shooting stop signal.

Like this, after being used for portrait that the MTF at optical axis Oc center measures and being taken into end, make camera 11 after the 1st quadrant moves, continuing from step S8, up to the end that is taken into from the view data of the 1st quadrant to the 4 quadrants to step S14 by XY axle drive division 16.

Promptly, in step S14, judge being taken into when not finishing of portrait data of All Quardrants, then enter step S15, by XY axle actuation step 16 dollying head 11 on the XY plane, make the optical axis Od of camera 11 aim at the image space of the next quadrant of picture 5.Then, turn back to step S8, the picture of the corresponding quadrant of making a video recording is measured peripheral mtf value.

In step S14, finish if judge being taken into of view data of All Quardrants, then enter step S16.

In step S16, in the MTF operational part 22, according to the mtf value of the camera data computing optical axis center at the above-mentioned optical axis Oc center that is taken between above-mentioned steps S3 ~ S7 by camera 11, be sent to MTF operational part 22.Among Figure 11 (A), the operation result of the mtf value P0 at the optical axis Oc center of the departure Zd=0 of indication window diametric plane for example is 50%.The mtf value P0 ' of the optical axis center shown in Figure 11 (A) is an operation result of opening the mtf value under the steady state (SS) of state with existing testing fixture at shutter, and its expression does not have to produce owing to the switch shutter mtf value of image blurring influence, for example is 65%.Like this, at the image blurring mtf value P0 that waits influence that comprises that obtains with this testing fixture, image blurring mtf value P0 ' is not low than having.

In step S17, in MTF operational part 22, according to the camera data computing periphery mtf value of the picture of the 1st quadrant to the 4 quadrants that are taken between above-mentioned steps S3 ~ S7 by camera 11, be sent to MTF operational part 22.Figure 11 (B) ~ (E) expression is as peripheral mtf value P1, P2, P3, the P4 of the mensuration operation values of the departure Zd=0 on the aperture plane.Peripheral mtf value P1 ', P2 ', P3 ', P4 ' that the existing testing fixture of usefulness shown in Figure 11 (B) ~ (E) obtains, be to open mtf value measurement result under the steady state (SS) of state at shutter, its expression does not have to produce owing to the switch shutter mtf value of image blurring influence.For peripheral mtf value, mtf value P1, the P2, P3, the P4 that comprise image blurring influence that obtains with this testing fixture equally, being lower than does not respectively have image blurring mtf value P1 ', P2 ', P3 ', P4 '.

In step S18, will compare by each mtf value and the check criteria value that said determination, computing are obtained, it is qualified to judge whether.For example, shown in Figure 11 (A), the standard value M0 that supposes the optical axis center mtf value is 70%, does not reach standard value as the above-mentioned optical axis center mtf value P0 that measures operation values, then is judged to be NG (defective).For example, shown in Figure 11 (B) ~ (E), the standard value M1 that supposes peripheral mtf value is 40%, satisfies standard value respectively as above-mentioned each the peripheral mtf value P1, P2, P3, the P4 that measure operation values, then is judged to be OK (qualified).

In step S18, on monitor 4, show above-mentioned result of determination, finish this program.Afterwards, the image pickup part main body 18 from MTF characteristic check device 10 unloads camera 6, the processing of end characteristic check.

In the present embodiment, before shutter device 74 carries out on-off action, begin shooting by camera 11, and respond the closing signal of shutter device 74 and stop shooting, but in order to reach purpose of the present invention, be not limited to this, also can in the switch motion of shutter device 74, make a video recording.That is, the shooting action also can be carried out in as the time T s of the time diagram among Figure 12.Therefore, both can make the signal Synchronization of opening of shooting beginning and shutter device 74, shown in time diagram, because integrated value does not change behind the closing motion that carries out shutter device 74, so also can when integrated value does not change, stop photography.

In the present embodiment, transmit the control data that is used to drive shutter device 74 switches from MTF characteristic check device 10 to camera 6.This is because the vibrations that shutter device 74 produces when driving etc. are to change driving time second (shutter speed) with shutter device 74 to drawing the Effect on Performance degree, therefore for example drives shutter device 74 can influence time second of drawing performance.Respectively drive drawing Effect on Performance degree, also change driving second time in the process flow diagram that can in Figure 10, represent of second time in order to check in addition.In this case, also can make the brightness of illumination of MTF characteristic check device 10 control pictures 5, even make driving time second of change shutter device 74 also can obtain suitable exposure by camera 11.

According to the MTF characteristic check device 10 of above-mentioned present embodiment, because the inspection method of the mtf value of the picture when using according to shutter release, so can be corresponding with the actual photographed that general object is photographed.Promptly, in the camera 6 that carries out above-mentioned characteristic check, at least at object during at gauged distance L1 place, if based on the lens sendout data condenser lens lens barrel 50 that writes among the above-mentioned EEPROM35, the photographs of optical axis center and picture periphery is with identical by the image degree of judging for above-mentioned MTF characteristic check device, in the MT reconnaissance F characteristic check device, carry out the judgement of the state close with the actual exposure state.

Check camera lens draw performance the time, in order to estimate mtf value according to institute's exposure image in shutter action, provide a kind of camera lens to draw the performance checking device, this testing fixture can be estimated the performance of drawing that comprises image blurring influence that the impact lens mount microseismic activity owing to shutter action produces, therefore can carry out with camera give actual photography situation behind the user suitable draw performance evaluation, quality when guaranteeing to produce provides high-quality camera to the user.

Though the plunger type electromagnet 66 that above-mentioned camera lens lens barrel 50 has been used as the shutter release drive source, but as drive source, be not limited only to electromagnet apparatus, for example for the camera lens lens barrel of using aperture motor and DC motor, perhaps, because lens mount when the blade switch motion such as employing spring-load mode can produce the lens barrel of small vibrations, also can use MT reconnaissance F characteristic check device.

And the present invention also can be used for using the lens barrel of the simple lens reflex camera of focal plane shutter except being used for using as being built in the shutter devices in the lens barrel 50 lens barrel of blade.As the camera of the checked property of MT reconnaissance F characteristic check device 10, can certainly be the digital camera beyond the roll film camera.

According to the present invention, a kind of performance checking device of drawing can be provided, this testing fixture can correctly be checked the resolution characteristic of the optical instrument suitable with actual photography state.

Claims (19)

1. An optical instrument draw the performance checking device, this optical instrument has the shutter of photographic lens and this photographic lens light path of switch, this testing fixture is characterised in that to have:

   At the picture that is provided with apart from above-mentioned camera predetermined distance place, describe to check the usefulness pattern;

   The shooting part of above-mentioned pattern being made a video recording by above-mentioned photographic lens;

   Control assembly, comprise the shooting action of controlling above-mentioned shooting part imaging control part, calculate the shutter release control part of the above-mentioned shutter release action of MTF operational part, control of modulation transfer function (MTF) based on the output of above-mentioned shooting part,

   Above-mentioned control assembly and above-mentioned shutter action are controlled above-mentioned shooting action explicitly, estimate the performance of drawing of above-mentioned optical instrument based on the output of at that time MT reconnaissance F operational part.
2. 2. the performance checking device of drawing according to claim 1 is characterized in that, above-mentioned control assembly make above-mentioned shooting part begin the shooting after, starting of above-mentioned shutter begun.
3. 3. the performance checking device of drawing according to claim 1 is characterized in that, above-mentioned control assembly above-mentioned shutter close release after, make above-mentioned shooting part stop the shooting.
4. 4. the performance checking device of drawing according to claim 3 is characterized in that, above-mentioned control assembly makes above-mentioned shooting part stop shooting after the stipulated time behind above-mentioned shutter release control part output shutter close signal.
5. 5. the performance checking device of drawing according to claim 3 is characterized in that, when above-mentioned control assembly does not change in fact in the output of judging above-mentioned shooting part, makes above-mentioned shooting part stop the shooting action.
6. 6. the performance checking device of drawing according to claim 1 is characterized in that, when above-mentioned control assembly is being made a video recording action at above-mentioned shooting part, carries out starting of above-mentioned shutter and does and close action.
7. 7. the performance checking device of drawing according to claim 1 is characterized in that, above-mentioned control assembly is estimated out the performance of drawing of above-mentioned optical instrument when starting of the above-mentioned shutter of change accomplished the time interval of closing action.
8. 8. the performance checking device of drawing according to claim 1 is characterized in that, has described to check on the substantial middle portion of above-mentioned picture and a plurality of periphery and has used pattern.
9. 9. the performance checking device of drawing according to claim 8 is characterized in that, also is provided with the drive division of the relative position relation of above-mentioned photographic lens of change and above-mentioned shooting part.
10. 10. the performance checking device of drawing according to claim 1 is characterized in that above-mentioned optical instrument is a camera.
11. 11. draw the performance checking device, have for one kind: shooting part, make a video recording by the photographic optical system that is configured on the assigned position as the camera of checked property; Picture is described predetermined pattern and is configured in and disposes the opposite side of above-mentioned shooting part one side, apart from above-mentioned camera predetermined distance is arranged; MTF calculates parts, based on the picture that above-mentioned shooting part is taken the photograph, calculates the MTF characteristic as the photographic optical system of the camera of above-mentioned checked property, and this is drawn the performance checking device and is characterised in that,

    Have shutter part, this shutter part is configured between above-mentioned picture and the shooting part, the light path of switch from above-mentioned picture to shooting part;

    MT reconnaissance F calculates parts based on comprising that starting of above-mentioned shutter part make or close the data that the stipulated time of the start-up time of at least one side in the action, above-mentioned shooting part take the photograph, and calculates the MTF characteristic of the photographic optical system of above-mentioned camera.
12. 12. the performance checking device of drawing according to claim 11 is characterized in that, has above-mentioned shutter part as the camera of above-mentioned checked property.
13. 13. the performance checking device of drawing according to claim 12 is characterized in that, also has the driving indicating device of the driving commencing signal of exportable above-mentioned shutter part.
14. 14. the performance checking device of drawing according to claim 13 is characterized in that, above-mentioned driving indicating device is exported the driving commencing signal of above-mentioned shutter part after above-mentioned shooting part begins shooting.
15. 15. the performance checking device of drawing according to claim 12 is characterized in that, any one actuator in above-mentioned shutter device selection plunger electromagnet, aperture motor, the DC motor is as drive source.
16. 16. the performance checking device of drawing according to claim 12 is characterized in that, above-mentioned shutter device is for using the shutter of a plurality of blades.
17. 17. the performance checking device of drawing according to claim 12 is characterized in that above-mentioned shutter device is a focal plane shutter.
18. 18. draw the performance checking method for one kind, be used to check have photographic lens, the optical instrument of the shutter of this photographic lens light path of switch draw performance, it is characterized in that, comprise the steps:

    The first step, by above-mentioned photographic lens, to apart from the configuration of above-mentioned camera predetermined distance place, describe to check that the picture with pattern begins to make a video recording;

    In second step, open above-mentioned shutter;

    In the 3rd step, close above-mentioned shutter;

    In the 4th step, finish above-mentioned shooting action;

    In the 5th step, go on foot the 4th step data of being made a video recording based on the above-mentioned the 1st and calculate the MTF characteristic;

    The 6th goes on foot, and estimates the performance of drawing of above-mentioned optical instrument based on the output in above-mentioned the 5th step.
19. 19. a camera is characterized in that, checks by the performance checking method of drawing of claim 18.

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