CN211652030U - Relative aperture measuring device for photographic objective lens - Google Patents

Relative aperture measuring device for photographic objective lens Download PDF

Info

Publication number
CN211652030U
CN211652030U CN202020483927.6U CN202020483927U CN211652030U CN 211652030 U CN211652030 U CN 211652030U CN 202020483927 U CN202020483927 U CN 202020483927U CN 211652030 U CN211652030 U CN 211652030U
Authority
CN
China
Prior art keywords
collimator
photographic objective
relative aperture
displacement
measuring
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN202020483927.6U
Other languages
Chinese (zh)
Inventor
王再丰
秦明海
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Suzhou Donghui Optical Co ltd
Original Assignee
Suzhou Donghui Optical Co ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Suzhou Donghui Optical Co ltd filed Critical Suzhou Donghui Optical Co ltd
Priority to CN202020483927.6U priority Critical patent/CN211652030U/en
Application granted granted Critical
Publication of CN211652030U publication Critical patent/CN211652030U/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Abstract

The utility model discloses a relative aperture measuring device of photographic objective, include: the device comprises an optical bench, a collimator, a diffusion screen, a holder, a camera assembly, a displacement table and a computer; the collimator is arranged on the optical bench, and the diffusion screen, the objective lens to be detected and the camera shooting assembly are sequentially positioned in the optical axis direction of the collimator; the diffusion screen is arranged on the optical bench through a fixing frame; the photographic objective to be tested is arranged on the holder and is arranged on the optical bench through the holder; the camera shooting assembly is arranged on the displacement platform, the camera shooting assembly is arranged on the optical bench through the displacement platform, and the camera shooting assembly is connected with the computer. In this way, the utility model discloses both can measure the entrance pupil diameter and can measure focus, need not to measure respectively through two kinds of equipment, simplified measurement procedure, be favorable to improving measurement accuracy.

Description

Relative aperture measuring device for photographic objective lens
Technical Field
The utility model relates to an optical measurement technical field especially relates to a relative aperture measuring device of photographic objective.
Background
The conventional measurement of the relative aperture of a photographic objective is realized by measuring the entrance pupil diameter and the focal length of the photographic objective respectively.
The measurement of the entrance pupil diameter is generally performed by using a focal plane point light source method or an experimental measurement microscope. In conventional entrance pupil diameter measurement, the entrance pupil diameter of a photographic objective is measured by the focal plane point source method, and the projected bright spot blocked by ground glass has a size equal to the entrance pupil diameter. In the measuring process, errors such as instrument errors, condition errors, human errors and the like exist due to selection of ground glass, selection of a scale, manual measurement by an operator and the like, and the measuring precision of the method is not very high. The entrance pupil diameter of the photographic objective is measured by using a measuring microscope, manual measurement is needed by an operator, automatic measurement cannot be realized, and time and labor are wasted.
For the measurement of the focal length of the photographic objective, magnification methods are generally used. The conventional focal length measurement uses a magnification method to measure the focal length of a lens or an optical system, and reads the distance between the images of the glass compass by an ocular micrometer on a microscope. Because of the complexity of the structure of the ocular micrometer, the imaging instability is easily caused when the micrometer hand wheel is rotated in the measuring process, and the convolution error is caused. And because only rely on the subjective judgement of operator, it is higher to the operator requirement, easily produce human error. When the workload is large, the eyes are extremely easy to be tired, the interpretation error is increased, and the working efficiency is greatly reduced.
The traditional measurement of the diameter of the entrance pupil of the photographic objective lens only can be used for respectively measuring the focal length and the diameter of the entrance pupil to obtain two numerical values, and then the relative aperture value is obtained through calculation, so that one-time measurement cannot be realized, the operation steps are complicated, and the measurement accuracy is easily caused to be inaccurate.
SUMMERY OF THE UTILITY MODEL
The utility model discloses the main technical problem who solves provides a relative aperture measuring device of photographic objective, can both measure the entrance pupil diameter and measure the focus, need not to measure respectively through two kinds of equipment, has simplified the measuring step, is favorable to improving measurement accuracy.
In order to achieve the above object, the technical solution of the present invention is:
a photographic objective relative aperture measuring device comprising: the device comprises an optical bench, a collimator, a diffusion screen, a holder, a camera assembly, a displacement table and a computer; the collimator is arranged on the optical bench, and the diffusion screen, the objective lens to be detected and the camera shooting assembly are sequentially positioned in the optical axis direction of the collimator; the diffusion screen is arranged on a fixed frame, and the diffusion screen is arranged on the optical bench through the fixed frame; the photographic objective to be tested is arranged on the holder and is arranged on the optical bench through the holder; the camera shooting assembly is arranged on the displacement table, the camera shooting assembly is arranged on the optical bench through the displacement table, and the camera shooting assembly is connected with a computer.
Preferably, the collimator internally comprises a bulb, ground glass, a glass rib plate and a collimator objective, and the bulb, the ground glass, the glass rib plate and the collimator objective are sequentially arranged from one side of the collimator entering the to-be-detected photographic objective to one side of the collimator close to the to-be-detected photographic objective.
Preferably, the glass rib plate is inserted into the collimator, and the glass rib plate is detachably connected with the collimator.
Preferably, the camera shooting component is a CCD industrial camera.
Preferably, the material of the diffusion screen is sub force plate.
Preferably, the outer surface of the diffusion screen is provided with a frosted layer.
Preferably, the displacement table comprises a bottom plate, a piezoelectric motor, a slider and a spring, the piezoelectric motor and the slider are arranged on the bottom plate, the slider is connected with the piezoelectric motor, and the slider slides on the bottom plate under the driving of the piezoelectric motor; the spring is arranged between one end of the piezoelectric motor, which enters and leaves the sliding block, and the bottom plate.
Preferably, the displacement table further comprises a guide rail, and the guide rail is arranged between the sliding block and the bottom plate.
Because of above-mentioned technical scheme's application, compared with the prior art, the utility model has the following beneficial effect:
(1) the device for measuring the relative aperture of the photographic objective can measure the diameter of the entrance pupil and the focal length without two devices, simplifies the measurement steps and is beneficial to improving the measurement precision;
(2) in the process of measuring the diameter of the entrance pupil, the traditional microscope measuring method is abandoned, the photographic objective to be measured is imaged on a photosensitive surface of the photographic assembly through the photographic assembly and the displacement table, images of left and right ruled lines are sequentially focused and positioned, the size of the diameter of the entrance pupil is determined according to the displacement of the electric displacement table, automatic measurement is realized, errors caused by manual measurement are effectively avoided, and the measuring precision can be effectively ensured;
(3) in the process of measuring the focal length, the photosensitive surface of the camera shooting assembly receives the image of the reticle pair formed by the camera shooting objective lens to be measured, the required measurement verticality is obtained through the connection and the output of the computer and the camera shooting assembly, the automatic interpretation and measurement can be realized, and the measurement efficiency is improved.
Drawings
Fig. 1 is a schematic structural diagram of a relative aperture measuring device of a photographic objective of the present invention.
Fig. 2 is a schematic structural diagram of the relative aperture measuring device of the photographic objective of the present invention in the focal length measuring process.
Fig. 3 is a schematic structural diagram of the relative aperture measuring device of the photographic objective of the present invention in the process of measuring the diameter of the entrance pupil.
Fig. 4 is an exploded view of a displacement stage in the relative aperture measuring device of a photographic objective of the present invention.
Fig. 5 is a schematic diagram of the medium voltage motor, the slider and the spring of the displacement table of the present invention.
Description of reference numerals:
the device comprises an optical bench 1, a collimator 2, a bulb 21, ground glass 22, a glass-rib plate 23, a collimator objective 24, a diffusion screen 3, a fixed frame 4, a to-be-detected photographic objective 5, a clamp 6, a camera assembly 7, a displacement table 8, a bottom plate 81, a piezoelectric motor 82, a sliding block 83, a spring 84, a guide rail 85, a computer 9, a distance y to a reticle, a distance y to the reticle image, a distance y ' to the reticle image, a collimator objective focal length fc ' and a to-be-detected objective focal length f '.
Detailed Description
The following detailed description of the preferred embodiments of the present invention will be provided in conjunction with the accompanying drawings, so as to enable those skilled in the art to more easily understand the advantages and features of the present invention, and thereby define the scope of the invention more clearly and clearly.
Referring to the drawings, a relative aperture measuring apparatus of a photographic objective comprises: an optical bench 1, a collimator 2, a diffusing screen 3, a holder 6, a camera assembly 7, a displacement stage 8 and a computer 9. The collimator 2 is arranged on the optical bench 1, the collimator 2 comprises a bulb 21, ground glass 22, a glass rib plate 23 and a collimator objective lens 24, and the bulb 21, the ground glass 22, the glass rib plate 23 and the collimator objective lens 24 are sequentially arranged from one side of the collimator 2 away from the photographic objective 5 to be detected to one side of the collimator 2 close to the photographic objective 5 to be detected. The glass-rib plate 23 is detachably connected in the collimator 2, that is, the glass-rib plate 23 can be arbitrarily inserted into and pulled out of the collimator 2. Because the glass-rib plate 23 needs to be inserted in the process of measuring the focal length and the diameter of the entrance pupil, and the glass-rib plate 23 needs to be pulled out in the process of measuring the focal length and the diameter of the entrance pupil, the glass-rib plate 23 and the collimator 2 are detachably connected, so that the collimator 2 is applicable to the two measuring processes.
The diffusion screen 3, the objective lens to be measured and the camera assembly 7 are sequentially located in the optical axis direction of the collimator 2, and the optical axis direction of the collimator 2 is taken as the optical axis direction of the measuring device, as shown by the dotted line position in fig. 1. The diffusion screen 3 is arranged on the fixing frame 4, and the diffusion screen 3 is arranged on the optical bench 1 through the fixing frame 4. Inferior power board can be selected for use to the material of diffusion screen 3, and the surface of diffusion screen 3 is provided with the dull polish layer, can make the collimated light that sends by collimator 2 form the diffuse light source through diffusion screen 3 better, effectively guarantees the measuring result of entrance pupil diameter. The photographic objective 5 to be measured is arranged on the holder 6, and the photographic objective 5 to be measured is arranged on the optical bench 1 through the holder 6.
The camera component 7 is arranged on the displacement table 8, the camera component 7 is arranged on the optical bench 1 through the displacement table 8, and the camera component 7 is connected with the computer 9. The camera assembly 7 may be a conventional CCD industrial camera known in the art.
The displacement table 8 includes a base plate 81, a piezoelectric motor 82, a slider 83, and a spring 84, the piezoelectric motor 82 and the slider 83 are provided on the base plate 81, and the slider 83 is connected to the piezoelectric motor 82. The sliding block 83 slides on the bottom plate 81 under the driving of the piezoelectric motor 82, and due to the direct-drive characteristic of the piezoelectric motor 82, a screw rod structure and a return clearance required by a common electromagnetic motor are not available, so that the overall size is reduced; meanwhile, the piezoelectric motor 82 has no return clearance and has the characteristic of extremely high stepping precision, so that the moving precision of the displacement table 8 is greatly improved, and the measuring precision of the measuring device can be improved.
The spring 84 is arranged between the end of the piezo motor 82 facing away from the slide 83 and the base plate 81, so that a certain pretension can be exerted on the piezo motor 82 in order to exert a better force on the slide 83 by the piezo motor 82. The spring 84 is arranged to provide a pre-tensioning force.
The displacement table 8 further comprises a guide rail 85, the guide rail 85 is disposed between the sliding block 83 and the bottom plate 81, and the guide rail 85 may be a guide rail 85 conventional in the art. Because the sliding block 83 slides on the bottom plate 81 when the moving platform works in the measuring process, the guide rail 85 is arranged, so that the moving precision of the sliding block 83 can be effectively ensured, and the effect of smaller friction can be achieved.
The measuring method of the device for measuring the relative aperture of the photographic objective lens is characterized in that parallel light emitted by a collimator passes through the photographic objective lens to be measured and then is imaged on a photosensitive surface of a CCD industrial camera, an optical signal is converted into an electric signal, and the electric signal is processed by a computer system to calculate the focal length value of the photographic objective lens to be measured.
During the measurement, the objective lens to be measured is positioned in front of the collimator objective lens, and a pair of scribed lines of the glass plate on the focal plane of the collimator objective lens are imaged on the focal plane of the objective lens to be measured. The distance y between the pair of reticle and the distance y 'between its image and the focal length f of collimator objective lens'cThe following relation exists between the focal length f' of the objective lens to be measured:
namely, it is
Parallel light emitted by the collimator forms a diffused light source after passing through the glass-compass plate, a reticle image of the glass-compass plate is focused and imaged by a CCD industrial camera, and the distance between the left position and the right position of the reticle image is determined by accurate displacement of the electric transfer platform, so that the diameter of an entrance pupil is obtained.
The method for measuring the relative aperture of the photographic objective lens specifically comprises the following steps:
assembling the device: the collimator, the to-be-measured photographic objective, the camera assembly and the displacement table are installed and fixed on the optical bench, and the optical axis direction of the collimator is taken as the optical axis direction of the measuring system. And adjusting the photographic objective to be measured to a gear to be measured, placing the photographic objective to be measured in the area to be measured, wherein the optical axis of the photographic objective to be measured is superposed with the optical axis of the collimator, namely the optical axis passes through the aperture center position of the photographic objective to be measured. For convenient measurement, the object space opposite displacement platform and the image space opposite collimator of the photographic object to be measured can be placed.
And taking down the lens of the camera shooting component, wherein the camera shooting component can select a CCD industrial camera, and the center of the target surface of the CCD industrial camera and the optical axis of the collimator are positioned at the same height. The output port of the CCD industrial camera is connected with a computer.
And (3) focal length measurement: the glass-rib plate is arranged in the parallel light tube, the glass-rib plate is arranged in parallel left and right according to the scribing line pair of the glass-rib plate, namely the distance between the selected scribing line pair and the imaging target surface of the CCD industrial camera is the transverse distance, and the y' expressed by the system focus measuring schematic diagram for conveniently expressing the imaging relation is the longitudinal distance.
And starting the collimator, the displacement table, the CCD industrial camera and the computer. The displacement table controller controls the displacement table to move the CCD industrial camera to the central position of the optical system, namely, the center of the target surface of the CCD industrial camera is positioned on the optical axis, and the reticle pair of the glass compass plate is conveniently imaged in the middle of the target surface of the CCD industrial camera. Moving the object to be measured to make the photosensitive surface of the camera assembly and the object focal plane of the object to be measured at the same position, imaging the reticle pair of the glass plate in the CCD industrial camera, and receiving the object to be measured by the photosensitive surface of the CCD industrial cameraThe image of the reticle pair. And measuring the minimum value of the image space of the reticle pair through a computer, wherein the minimum value is the focal length value of the photographic objective lens to be measured. The numerical value is connected with a CCD industrial camera through a computer, detected and output a group of video signals, processed and then according to a formulaThus obtaining the product.
Entrance pupil diameter measurement: and after the power supply of the collimator is turned off, the glass screw plate in the collimator is taken out, and then the collimator is turned on. The diffusion screen is arranged on the optical bench through a fixing piece, and the central position of the diffusion screen and the optical axis of the collimator are positioned on the same height, namely the optical axis passes through the central position of the diffusion screen. And mounting the lens on the CCD industrial camera, and starting the CCD industrial camera.
Focusing the glass-rib-plate scribed line image of the collimator through the camera shooting assembly in the object space of the photographic objective to be detected, moving the CCD industrial camera through the displacement table to enable the left edge and the right edge of the glass-rib-plate scribed line image to be sequentially imaged at the center position of the target surface of the camera shooting assembly, respectively recording displacement values of the displacement table during two imaging by the computer, and obtaining the difference of the two displacement values as the entrance pupil diameter value of the photographic objective to be detected.
Obtaining the aperture value: and the ratio of the diameter value of the entrance pupil to the focal length value is a relative aperture value of the photographic objective lens to be measured, and the relative aperture value is obtained through computer processing.
Through the utility model discloses well photographic objective relative aperture measuring device's measuring method both can measure the entrance pupil diameter and can measure the focus, need not to measure respectively through two kinds of equipment, has simplified measuring procedure, is favorable to improving measurement accuracy. In the process of measuring the diameter of the entrance pupil, the traditional microscope measuring method is abandoned, the photographic objective to be measured is imaged on the photosensitive surface of the photographic component through the photographic component and the displacement platform, the images of the left and right ruled lines are sequentially focused and positioned, the diameter of the entrance pupil is determined according to the displacement of the electric displacement platform, automatic measurement is realized, errors caused by manual measurement are effectively avoided, and the measuring precision can be effectively ensured. In the process of measuring the focal length, the CCD system is used as a photoelectric detection device to be applied to the measurement of the focal length of the objective lens. The photosensitive surface of the camera shooting assembly receives the image of the reticle pair formed by the camera shooting objective lens to be measured, the required measurement verticality is obtained through the connection and the output of the computer and the camera shooting assembly, the automatic interpretation and measurement can be realized, and the measurement efficiency is improved.
The above is only the embodiment of the present invention, not limiting the scope of the present invention, all the equivalent structures or equivalent processes of the present invention are used in the specification and the attached drawings, or directly or indirectly applied to other related technical fields, and all the same principles are included in the protection scope of the present invention.

Claims (8)

1. A photographic objective relative aperture measuring device, comprising: the device comprises an optical bench, a collimator, a diffusion screen, a holder, a camera assembly, a displacement table and a computer; the collimator is arranged on the optical bench, and the diffusion screen, the objective lens to be detected and the camera shooting assembly are sequentially positioned in the optical axis direction of the collimator; the diffusion screen is arranged on a fixed frame, and the diffusion screen is arranged on the optical bench through the fixed frame; the photographic objective to be tested is arranged on the holder and is arranged on the optical bench through the holder; the camera shooting assembly is arranged on the displacement table, the camera shooting assembly is arranged on the optical bench through the displacement table, and the camera shooting assembly is connected with a computer.
2. A photographic objective relative aperture measuring device according to claim 1, characterized in that: the collimator comprises a bulb, ground glass, a glass rib plate and a collimator objective lens, wherein the bulb, the ground glass, the glass rib plate and the collimator objective lens are sequentially arranged from one side of the collimator far away from the photographic objective lens to one side of the collimator close to the photographic objective lens.
3. A photographic objective relative aperture measuring device according to claim 2, characterized in that: the glass rib plate is inserted in the collimator and detachably connected with the collimator.
4. A photographic objective relative aperture measuring device according to claim 1, characterized in that: the camera shooting component is a CCD industrial camera.
5. A photographic objective relative aperture measuring device according to claim 1, characterized in that: the diffusion screen is made of acrylic plates.
6. A photographic objective relative aperture measuring device according to claim 1, characterized in that: and a frosted layer is arranged on the outer surface of the diffusion screen.
7. A photographic objective relative aperture measuring device according to claim 1, characterized in that: the displacement table comprises a bottom plate, a piezoelectric motor, a sliding block and a spring, wherein the piezoelectric motor and the sliding block are arranged on the bottom plate, the sliding block is connected with the piezoelectric motor, and the sliding block slides on the bottom plate under the driving of the piezoelectric motor; the spring is arranged between one end, far away from the sliding block, of the piezoelectric motor and the bottom plate.
8. A photographic objective relative aperture measuring device according to claim 7, characterized in that: the displacement table further comprises a guide rail, and the guide rail is arranged between the sliding block and the bottom plate.
CN202020483927.6U 2020-04-03 2020-04-03 Relative aperture measuring device for photographic objective lens Active CN211652030U (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202020483927.6U CN211652030U (en) 2020-04-03 2020-04-03 Relative aperture measuring device for photographic objective lens

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202020483927.6U CN211652030U (en) 2020-04-03 2020-04-03 Relative aperture measuring device for photographic objective lens

Publications (1)

Publication Number Publication Date
CN211652030U true CN211652030U (en) 2020-10-09

Family

ID=72686882

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202020483927.6U Active CN211652030U (en) 2020-04-03 2020-04-03 Relative aperture measuring device for photographic objective lens

Country Status (1)

Country Link
CN (1) CN211652030U (en)

Similar Documents

Publication Publication Date Title
US4697893A (en) Microscope with a binocular tube
US6151161A (en) High-precision computer-aided microscope system
JPH10502466A (en) Autofocus system for scanning microscopy
CN105675266A (en) Device and method for measuring modulation transfer function of optical lens based on infinite conjugate optical path
CN2605569Y (en) Semi automatic V prismatic refractometer
CN208999256U (en) A kind of apparatus for measuring contact angle based on mobile phone photographic
CN110057554A (en) The MTF detection device and detection method of zoom lens image quality
JP3482013B2 (en) Optical system focus evaluation method, adjustment method, adjustment device, and chart device
CN1275065C (en) Spectrum face coordinate calibrating device for digital scanning optical transfer function detector
CN211652030U (en) Relative aperture measuring device for photographic objective lens
JPH10311779A (en) Equipment for measuring characteristics of lens
CN2660522Y (en) Manually operated high precision internal hole optical detector
JP2002531153A (en) Apparatus and method for measuring image deviation of human eye
CN111272397A (en) Device and method for measuring relative aperture of photographic objective lens
CN110823531A (en) Novel digital optical bench
CN1493846A (en) Polymer optical fiber characteristic parameter testing apparatus and its testing method
US1281035A (en) Microscopic measuring machine.
KR100586911B1 (en) Auto collomator apparatus having cartridge prism
CN210893618U (en) Multifunctional novel optical focal length measuring instrument
CN106768872B (en) A kind of automatic focimeter
CN210036604U (en) Device for detecting height difference of binocular telescope system
CN209727759U (en) A kind of rapid survey instrument of optical glass refractive index
US5307098A (en) Projection inspecting machine
CN210863102U (en) Image plane spherical aberration distribution testing device of self-focusing lens
CN209877884U (en) Device for testing optical axis position degree of cutting lens

Legal Events

Date Code Title Description
GR01 Patent grant
GR01 Patent grant