SU1114909A1 - Device for determination of cine-photo camera defocusing (its versions) - Google Patents

Abstract

1. A device for determining the defocusing of a shooting camera, containing a test camera with a lens, in the film channel of which a flat mirror is located, and an autocollimator device installed coaxially with the camera, characterized in that it is equipped with an aperture between the camera lens to improve measurement accuracy and an autocollimator device, the transparent areas of which are made asymmetrically relative to the optical axis of the device, and the surface of the opaque areas of the diaphragm is reversed the camera lens is formed as a flat mirror. 2. The device according to A.1, I t. The fact that the diaphragm is made in the form of a sector raster on a glass disk on which a specular and light absorbing coating is applied, and the number of sectors of the raster satisfies the relation

Description

An autocollimator device with a position-sensitive photodetector, as well as a light modulator mounted between the camera lens and the autocollimator device, which, in order to measure the measurement accuracy, is equipped with a diaphragm installed between the modulator and the camera lens, the transparent portion which is made in the form of a slit, one of the large sides of which coincides with the optical axis of the camera lens and covers its diameter, and the surface of the opaque portion of the diaphragm reverses Enna camera lens, made in the form of a flat mirror.

The invention relates to optical instrumentation, more specifically to optical devices for monitoring the position of the focal plane of the lens relative to the plane of the film in the imaging camera, as well as for determining the position of the focal plane of individual lenses, lenses and concave spherical mirrors.

A device for determining the defocusing of a shooting camera based on autocollimation is known, comprising an autocollimator, a test shooting camera with a lens and a mirror-lens system installed in a film taped by the shooting camera under test.

In this device, the magnitude and sign of the defocusing are determined by the magnitude and sign of the defocusing of the object va of the autocollimator necessary to achieve the sharpness of the autocollimation image of the mark observed by the operator's eye in the eye of the autocollimator 1.

The closest to the technical essence of the invention (the first embodiment) is a device for determining the defocusing of a shooting camera, containing a test camera with a lens, in a film channel which has a flat mirror and an autocollimator device coaxially mounted with the camera.

The magnitude and sign of the defocusing camera of the camera are determined by the magnitude and sign of the defocusing of the autocollimator lens, which is necessary to achieve the sharpness of the autocollimation image of the mark that the operator observes in the ocular p of the autocollimator and t.21.

The disadvantage of these devices is low measurement accuracy due to low sensitivity of the eye to longitudinal defocusing.

The closest to the technical essence of the invention (according to the second variant) is a device for determining the defocusing of a shooting camera, containing a test camera with a lens, in the film channel of which a flat mirror is located, an autocollimator device coaxially mounted with the camera and two apertures with optical filters located in one plane between the camera and the autocollimator device on opposite sides of the optical axis of the lens of the camera, with the possibility of adjusting the distance between the axes of the orifice plates and the axis of ektiva camera.

The defocus amount of the test chamber is determined by the degree of alignment in the plane of the grid of the observing device of two autocollimating images of marks, with one autoclipping image formed by an edge beam passing through one aperture of the autocollimator device, and the second autocollimation image passing through the other aperture of the beam same device. The defocusing sign of the camera is determined depending on the side from which the autocollimation image of the corresponding brand is formed relative to the center of the grid.

The measurement accuracy is increased by transforming the longitudinal defocusing of the test chamber into the lateral defocusing of the autocollimation images of the HF marks. The closest to the technical essence of the invention (in the third embodiment) is a device for determining the defocusing of a shooting camera, comprising a test camera with a lens, in a film channel of which a flat mirror is located, an autocollimator device positionally sensitive to a photoreceiver, and a modulator light, mounted between the camera lens and the autocollimator device. The defocus amount of the test chamber is determined by degree. combining in the plane of installation a position-sensitive photodetector or a line of photoreceivers of two autocollimation images of marks formed by modulated light beams, while one of the autocollimation images is also formed by an edge beam of light passing through a single diaphragm of the autocollimator device, and the second autocollimation image is transmitted by an edge beam of the rays that have passed through another aperture of the same device, and the defocusing sign of the camera is determined depending on Which side relative to the center position-sensitive photodetector or fotopri- line. The image of the corresponding mark Z is formed by an autocollimation image. A disadvantage of the known devices is the low accuracy of determining the magnitude of small defocusing of a shooting camera caused by a small displacement relative to the optical axis of the camera lens of the image of the mark formed by the edge beam in the plane of the camera mirror. increased measurement accuracy. This goal is achieved by the fact that the device for determining the defocusing of a shooting camera (in the first embodiment), containing the test camera with a lens, in the film channel of which there is a flat mirror, and an autocollimator device mounted coaxially with the camera, is equipped with an aperture installed between the camera lens and the camera collimator devices, transparent areas of which are made asymmetrically relative to the optical axis of the device, and the surface of the opaque areas of the diaphragm facing the lens the chamber is formed as a flat mirror. The diaphragm is made in the form of a sector raster on a glass disk on which mirror and light absorbing coatings are applied, and the number of raster sectors satisfies the relation (), where 2. is the number of raster sectors, and U is any integer number. In this case, the sector raster is made with an opaque central section. A device for determining the defocusing of a shooting camera (according to the second variant), containing a test camera with a lens, in the film channel of which there is a flat mirror, installed an autocollimator device coaxially with the camera and two diaphragms with light filters located in the same plane between the camera and the autocollimator device on opposite sides from the optical axis of the camera lens with the ability to adjust the distance between the axis of the diaphragms and the axis of the camera lens, equipped with a lens installed between osnovnmi diaphragms measures and additional diaphragm transparent portions which are identical, are oriented along the axes of the main aperture and arranged asymmetrically about the optical axis of the camera lens, and the surface of the opaque portion facing the camera lens is formed as a flat mirror. A device for determining the defocusing of a shooting camera (in the third embodiment), containing a test camera with a lens, in the film channel of which there is a flat mirror mounted coaxially with the camera, an autocollimator device with a position-sensitive photodetector, and a light modulator mounted between the camera lens and the autocollimator device equipped with a diaphragm installed between the modulator and the camera lens, the transparent portion of which is made in the form of a slit, one of the large sides of which The swarm coincides with the optical axis of the camera lens and overlaps its diameter, while the surface of the opaque portion of the diaphragm facing the camera lens is made in the form of a flat mirror. Fig. 1 is a schematic diagram of the first embodiment of the device; figure 2 is an additional diaphragm in the form of a sector raster; Fig. 3 is a diagram of the execution of a raster on a glass disk; Fig. 4 shows a diagram of the first embodiment of the device in case it is used to determine the position of the focal plane of the concave spherical mirrors in Fig. diaphragm in a viral sector raster with a central opaque part; figure 6 is the same section; 7 is a diagram of a second embodiment of the device; on Fig the aperture of the second variant of the device; figure 9 - scheme. the third variant of the device; FIG. 10 shows an additional diaphragm of the third embodiment of the device; FIG. 11 - light modulator, in FIG. 12 image of the mark on the ocular grid of the first variant of the device in the case of a defocused camera; on Fig - the same, the days of the focused camera lens; Figures 14 and 15 of the beam path through the lens of the test camera at its plus defocusing in the first variant of the device; on Fig and 1 7 the same, with minus defocus in the first embodiment of the device; Figures 18 and 19 illustrate diagrams of the passage of a beam of rays between the mirror surfaces of the diaphragm and the concave spherical mirror with plus defogging in the first embodiment of the device; FIGS. 20 and 21 are the same with minus defocus in the first embodiment of the device; FIG. 22 2 .4 are images of the mark on the hand, a mesh of the second version of the device in the case of minus defocus, normal focus and plus defocus, respectively: ; FIGS. 25 to 27 show the violation of symmetry of the marks on the ocular grid of the second device variant when using two maro in the case of minus defocus, normal focus and plus focus, respectively; Figures 28 and 29 are diagrams of the passage of the edge beam through the lens of the test chamber with plus defocusing in the second embodiment of the device; on Fig and 31 - the same, with minus defocus in the second embodiment of the device; 32-34 are diagrams of image marks on the image analyzer of the third device variant in the case of plus defocus, normal focus and minus defocus, respectively; in fig. 35-37 light beam transmission patterns through the slit of the image analyzer in the third embodiment of the device in the case of plus defocus, normal focus and minus defocus, respectively; Figures 38-40 illustrate graphs of the change in time of the radiation flux incident on the photodetector ff, the electrical signal 11 taken from the photodetector, and the reference electrical signal Uon in the third embodiment of the device in the case of minus defocus, normal focus and plus defocus. The device according to the first embodiment (FIG. 1) contains a test chamber 1 with a lens 2, an autocollimator 3 mounted coaxially with it, a flat mirror 4 installed in the movie channel of chamera 1, a diaphragm 5 made in the form of a concentric sector raster with transparent sectors 6 and the opaque sectors 7 formed by a mirror coating, on which the light-absorbing coating 8 is applied. The diaphragm 5 is made in the form of a raster on a glass disc 9 and installed between the lens 2 and the autocollimator device 3 so that erkalnoe coating opaque sector 7 drawn to the lens 2 and perpendicular to its optical axis. The autocollimator 3 contains a lens 10 mounted with the possibility of movement along the axis, a readout mechanism 11, an illuminator 12 with a light filter 13, a mark 14, a prism-cube 15 with a beam-splitting hypotenuse edge 16, an ocular grid 17 and an ocular 18. Instead of an ocular 18 can be a microscope or television sensor (not shown). In the first embodiment of the device, dp, determining the position of the focal plane of the concave spherical mirrors, the device contains instead of

. test chamber 1 with lens 2 test concave spherical mirror 19, and the diaphragm 5 contains an opaque central section 20 and is made of metal, and the opaque sectors 7 are formed by a polished metal surface facing the spherical mirror 19.

The device according to the second variant (FIG. 7) comprises the test chamber 1 with a lens 2, an autocollimator 3 mounted coaxially with it, a flat mirror 4 mounted in the film channel of camera 1, and an additional diaphragm 5 located between the autocollimator 3 and the lens 2 Instead of the light filter 13 a polarizer can be used. In the second version of the device, the light filter or polarizer 13 is made of two halves 21 and 22, through which two half 23 and 24 marks 14 are illuminated, respectively. Between the additional diaphragm 5 and the autocollimator device 3, the main diaphragms 25 and 26 are installed, one with a light filter or polarizer 27 , a friend with a light filter or a polarizer 28. The aperture 5 has transparent sections 29 and 30 along the axis of the main diaphragms, which are asymmetrically located relative to the optical axis of the lens 12. At the same time, the diaphragms 25 and 26 or transparent sections 29 30 additional diaphragm 5 or the diaphragm, and 25 and 26 and the transparent portions 29 and 30 of the diaphragm 5 are installed asymmetrically with respect to the lens axis 2 of the chamber 1.

Instead of mark 13 in the form of a slit in the collimator device 3, two marks can be installed with corresponding light filters or polarizers, or one combined mark consisting of two parts, the central part 31, made in the form of a rectangular slit, transmitting the spectrum of light rays that passed the light filter.

21, and the Bisssector 32, which transmits the spectrum of the rays that have passed the light filter 22. Instead of the ocular 18, a microscope or a television sensor (not shown) can be installed.

The device according to the third variant (FIG. 9) contains a test chamber 1 with a lens 2, an autocollimator device 3 which is installed coaxially with it, including an axially displaced lens 10, an illuminator 12, and c. tofipr 13, mark 14, prism-cube 15 with beam-splitting face 16, image analyzer 33 installed in the focal plane of lens 10, optically matched with lens 34 with photoreceiver 34. In the film of Camrra 1,

0 flat mirror 4, and between camera 1 and lens 10 an opaque additional aperture 5 is installed with a transparent section 36 made in the form of a slit, one of the larger sides of which coincides with the optical axis of lens 2 and overlaps the light diameter of the lens 2, and the opaque section 7 of the diaphragm 5 facing the lens, made in the form of a flat

0 a mirror perpendicular to the axis of the object 2. Between the diaphragm 5 and the lens 10 is installed, the light modulator 37 is rotatably around an axis parallel or coinciding with the axis of lens 2, executed in the form of an opaque disk with a transparent half ring 38 (Fig. eleven ). The modulator 37 is kinematically associated with a gear ratio unit with the shaft of an electric motor-generator

0 39. The output of the photodetector-35 is connected to the input of the amplifier 40, the output of which is connected to one input of the electronic switch 41, containing a phase-sensitive detector (not shown), the second input of which is connected to the tachogenerator 39, and the output of the electronic switch 41 is connected to the servo motor 42, drive mechanism for moving the lens 43 10. The latter (go to mechanism 43) is kinematically connected with the displacement sensor 44, the signal from which is sent to the indicating

5, device 45. The image analyzer 33 is made in the form of a right-angled; gr holes 46 (slit) (Fig), pac-i put eccentrically optical axis of the autocollimator device 3.

The defocusing of a shooting camera 1 by a device according to the first embodiment is carried out as follows.

A beam of light from illuminator 12 passes through mark 14, prism-cube 15, lens 10, transparent portions 6 of diaphragm 5 and is focused by lens 2 onto a flat mirror 4. The beams reflected from the mirror 4 emerge from the lens 2, are reflected by the mirror surfaces 7 of the diaphragm 5, and are again focused by the lens 2 into the plane of the mirror 4. The beams reflected twice from the mirror 4 leave the lens 2 and are focused by the lens 10 into the plane of the grid 17. In eyepiece p 18 see twice the autocollimation image of the mark 14, the shape of which depends on the size and sign of the defocusing of the camera 1. The shape of the autocollimation image 47 (Fig. 12) of the mark 14 as a hole is formed when the defocused camera 1, the shape of the autocollima The ion image 48 (Fig. 13) corresponds to a correctly focused camera 1. Determining the position of the focal plane of the spherical mirror 19 is carried out in a known manner, and the opaque portion 20 of the diaphragm 5 performs the functions of a flat mirror 4 installed in the film channel of camera 1. Axial By moving the autocollimator device 3, the image of mark 13 visible in the eye can be laterally focused. 18. In the diagrams of the rays passing through the lens of the test camera at its plus or minus defocus with loshn lines indicate beams directed into the lens 2 from the chamber 1 avtokollimatornogo device 3, and the dashed - rays exiting the lens 2 and fall into aB tokollimatornoe autocollimating device 3. Form 47 brand image 14 in this case will be distorted hydrochloric. By axial movement of the lens 1, the directions of propagation of the rays coincide, the two cameras 1 enter the lens and the output: from it, while the autocollimation image of 48 mark 14 will be undetectable. In determining the defocusing of the spherical mirror 19, also by axial movement of the lens 10 of the autocollimator 3, focusing (undistorted shape) of the image 48 of mark 14 is achieved, and on a scale 11 of the drift of the lens 10, the magnitude and sign of the defocusing of the shooting camera 1 or the spherical mirror 19 are determined. chromatic aberrations in the illuminator are installed light filter 13 with a narrow transmission spectrum. The determination of the defocusing of a shooting camera. The device according to the second embodiment is carried out as follows. The light beams from the illuminator 12 pass through the light filters 21 and 22, mark 14, prism-cube 16j lens 10, the main diaphragms 25 and 26 with light filters 27 and 28, transparent portions 29 and 30 of the aperture 5, are focused by the lens 2 on the plane of the mirror 4, are reflected from it, coming out of lens 2, are reflected from the mirror surface 7 of the diaphragm 5 and are secondly focused by the lens 2 onto the plane of the mirror 4. After reflecting from the mirror 4 rays, the lens 2 passes, the transparent section 29 or 30 of the aperture 5, the light filter 27 or 28, aperture 25 or 26 and lens 10 are focused in a plane The grids 17. At the same time, only the rays of light pass through the diaphragm 25, creating on the grid 17 an image 49 (FIG. 22) of one part of the mark 14, and through the diaphragm 26 - rays of light, creating an image 50 (FIG. 22) of the other part of the mark 14. When the focused camera 1 is paired, the images of the two parts 49 and 50 of mark 14 are divided in the plane of the ocular grid 17 or the image of the central part 52 of the combined mark 13 asymmetrically with respect to the image of the bisector 51 (Fig. 25). In this case, a parallel beam of rays that falls into the lens 2 of the test chamber 1 comes out diverging or converging from there. By axial movement of the lens 10 (Fig. 7), the directions of propagation of the rays entering and leaving the lens 2 are achieved. In this case, the images 49 and 50, or 51 and 52 parts of the mark 13 in the plane of the ocular grid 17 will be mutually symmetrical. Also on a scale of 11, the value and sign of the defocusing of the test camera 1 are read out. Chromatic aberrations are eliminated as in the first variant by installing the corresponding optical filters 13. The device according to the third variant determines the defocusing of the contact camera 1 as follows. A beam of light from the illuminator 12 passes the filter 13, mark 14, prism-cube 15, lens 1.0, transparent section 38 of the modulator 37, transparent section 36 of the diaphragm 5 and is focused by lens 2 in the plane

mirrors 4. A beam of light reflected from mirror 4 passes a diametrically opposite part of lens 2, is reflected from mirror surface 7 of flap 5, and lens 2 is re-focused in the plane of mirror 4.. The mirror is reflected again. In order to scan 4, a beam of light successively passes the lens 2, the transparent section 36 of the diaphragm 5, the transparent section 38 of the modulator 37 and the lens 10 is focused in the plane of the image analyzer 33. Further, a part of the light beam passes through the rectangular opening 45 (slit) of the image analyzer 33 without the aid of the lens 34, is directed to the photodetector 35. The light beam transmission pattern with the relative positions of the transparent portions 36 and 38 of the aperture 5 and the modulator 37 shown is shown

solid lines with arrows. The eccentric position of the transparent section 36 of the diaphragm 5 relative to the optical axis of the lens 2 leads to the fact that the beam coming from the mark 14 and past the transparent portions of the modulator 37 and the diaphragm 5, twice passing the lens 2, hits the mirror surface 7 of the diaphragm 5, since any the point of the transparent area 36 relative to the optical axis of the lens 2 is symmetrical to a point on the opaque mirror area of the diaphragm 5. When the modulator 37 rotates with a period T for one half period, an image is created in the plane of the image analyzer 33 image 53 (Fig. 32) of mark 14, formed by a beam of rays passing through one edge portion of the lenses 2 and 10, in this case beams,

Indicated by solid lines.

During the second half-cycle, the rotation of the modulator 37 in the installation plane of the image analyzer 33 creates an image 54 (Fig. 32) of mark 14, formed by a beam of rays passing through the opposite edge portion of the lenses 2 and l6, in this case the beam of rays, indicated by dashed lines .

 The mutual arrangement of images 53 and 54 in the plane of the image analyzer 33 depends on the size and sign of the defocusing of camera 1. Beams of rays passing through one edge of lenses 2 and 10, during the first half-cycle of rotation of the modulator 37, form the image 53 of mark 14, indicated by dashed lines. lines and beams passing through the other edge of lenses 2 and 10 during the second half period

The rotation of the modulator 37 is formed by the image 54 of mark 14, indicated by solid lines. At the same time, With plus defocused camera 1, most of the image 53 is

5 as compared with 54 falls on slit 46 of the image analyzer 33, with properly focused camera 1, images 53 and 54 coincide in the plane of the analyzer 33 and on slit 46

20, the same part of them occurs, with minus defocused camera 1, the slit 46 contains most of the image 54. This means that with the defocused camera 1-5 the radiation flux incident on the photoreceiver 35 periodically changes its amplitude with a period equal to the period of rotation of the modulator 37, The ac of the photodetector 35 removes the pulsating voltage 0 with the same period UM.

With a correctly focused camera 1, the radiation flux entering the photodetector 35 is constant in time and is removed from the photoreceiver 35

5 constant voltage. The signal from the photodetector 35 is amplified in the amplifier 40 and enters the electronic switch 41, which also receives the signal Uon from the electric motor-generator 39, the shaft of which is kinematically connected to the modulator 37. The electronic switch 41 depending on the amplitude of the pulsations of the signal Uof, taken from the photodetector 35, and also depending on the coincidence or opposite of the phases of the signal Ucp and Uoq, generates a corresponding command signal and sends it to the servomotor 42, which by means of the mechanism 43 moves along the axis one side or another of the lens 10. The movement of the lens 10 is carried out until the image

S nor 53 and 54 marks 14 in the plane

analyzer 33. In this case, a constant voltage is removed from the photodetector 35 and a signal is not received to the servomotor 42, the displacement sensor 44, the sensor associated with the mechanism 43 or the lens 10, sends information about the magnitude of the displacement of the lens 10 to the indicating device. the magnitude of the focal length of the lens 2, the indicating device 45 can be calibrated directly in the defocusing values of the test camera under test. Thus, repeated autocollimation from the mirror surface of an additional diaphragm of light beams reflected by a flat mirror in the film channel of the camera, coming out of the camera lens, and re-directing them. 11 11

6 Fs / d.2. 9 the camera through the lens on the flat mirror installed in the film channel improves the accuracy of measuring the defocusing of the camera in all versions of the device, because with a defocused camera, each beam of light directed by the autocollimator to the camera lens is reflected twice from the flat mirror in the film channel and gets back into the autocollimator device with 2 times more longitudinal and transverse defocusing compared to the light beam, once reflected from the flat mirror installed in the movie channel.

eight

FIG. four

FIG. five

Y /////// A

6

Fg / g7

FIG. 8 .9 Phage.U.

48

FIG. P

Fig. / Z

FIG. 13

7

2

V

P f 49 23

fPuz.2d 24 50

Fi2.29 with

z s

p

Fig. 30 Fig. 3d rfj 2S22 & FIG. 35

Fig.31 f {/ g.ZZ i 53, S Figs. 34 ffisiSfe FIG. 36

r

YGG

Fs.37

FIG. 39

Ff

F, Fg

USRFig. 38

FIG. 40

Claims (5)

DEVICE FOR DETERMINING DAC- FOCUSING A CAMERA CAMERA (ITS OPTIONS). . '' (57) 1. A device for determining the defocusing of a film camera, containing a test camera with a lens in the film channel of which there is a flat mirror, and an autocollimator device installed coaxially with the camera, characterized in that it is equipped with a diaphragm in order to increase the measurement accuracy installed between the camera lens and the autocollimator device, the transparent sections of which are made asymmetrically with respect to the optical axis of the device, and the surface of the opaque sections of the diaphragm facing camera lens is formed as a flat mirror. 2. The device according to claim 1, characterized in that the diaphragm is made in the form of a sector raster on a glass disk on which a mirror and light-absorbing coating is applied, and the number of sectors of the raster satisfies the relation where ί is the number of sectors of the raster, ¹⁴ is any integer. 3. The device according to claim 2, which is related to the fact that the sector raster is made with an opaque central portion. 4. A device for determining the defocusing of a shooting camera, containing a test camera with a lens, in the film channel, which has a flat mirror, an autocollimator device installed coaxially with the camera, and two diaphragms with light filters located in the same plane between the camera and the autocollimator device on opposite sides of the optical axis' of the camera lens with the ability to adjust the distance between the axes of the diaphragms and the axis of the camera lens, characterized in that, in order to improve measurement accuracy, it equipped with an additional diaphragm installed between the camera lens and the main diaphragms, the transparent sections of which are identical, oriented along the axes of the main diaphragms and are located asymmetrically relative to the optical axis of the camera lens, and the surface of the opaque section facing the camera lens is made in the form of a flat mirror. 5. A device for determining the defocusing of a shooting camera, containing a test camera with a lens, in the film channel of which there is a flat mirror, an autocollimator device with a position-sensitive photodetector coaxial with the camera, and a light modulator installed between the camera lens and the autocollimator device, characterized in that, in order to improve measurement accuracy, it is equipped with a diaphragm installed between the modulator and the camera lens, the transparent portion of which is made n in the form of a slot, one of the major sides of which coincides with the optical axis of the camera lens and overlaps its diameter, and the surface of the opaque portion of the stop facing the camera lens is formed as a flat mirror.