Device and method for testing modulation transfer function value of self-focusing lens array

Abstract

Some embodiments of the invention provide a test device and method for a self-focusing lens array modulation transfer function value, the device comprises a light source module, a resolution module, an array moving module and a measurement module, the light source module is used for providing an original light source; the resolution module is used for determining a periodic light source corresponding to the original light source according to the original light source; the array moving module is used for moving the to-be-tested array; the measurement module is used for photographing the image of the array to be measured to obtain a measurement image, determining a modulation transfer function value corresponding to the array to be measured according to the measurement image, and performing photographing analysis on the image of the array to be measured by adjusting the distance between the array to be measured and the measurement module so as to calculate the modulation transfer function value; the distance between the to-be-tested array and the measuring module can be randomly adjusted according to needs, so that the self-focusing lens array with short focal length can be measured, the testing efficiency is high, and the cost is low.

Description

Technical Field

[0001] The present application relates to the field of optical measurement technology, and in particular to a device and method for testing the modulation transfer function value of a self-focusing lens array. Background Art

[0002] In the prior art, when testing the objective lens, the following method is usually used: Figure 1 The test instrument shown includes: a light source 1, a condenser 2, a variable filter 3, a variable slit 4, a collimator objective 5, a measured objective 6, a spatial frequency slit 7, a lens 8, a rotating grating scanner 9, a semi-reflective semi-mirror 10, a visual observation mirror 11, a condenser 12 and a photoelectric receiver 13; in a specific implementation process, the measured objective 6 images the variable slit 4 on the rotating grating scanner 9, realizing relative scanning between the variable slit 4 and the rotating grating scanner 9, and the light flux of the effective scanning hole that changes with time is received by the photoelectric receiver 13 and converted into an electrical signal, thereby realizing frequency conversion.

[0003] Since the distance between the measured objective lens 6 and the photoelectric receiver 13 is very long, Figure 1 The test instrument shown can be used to measure the objective lens with long focal length, certain aperture size and axisymmetric structure, but cannot measure the objective lens with short focal length, small aperture and asymmetric axis. How to test the objective lens with short focal length, small aperture and non-axisymmetric structure at a low cost is a technical problem that needs to be solved urgently. Summary of the invention

[0004] The purpose of some embodiments of the present application is to provide a test device and method for the modulation transfer function value of a self-focusing lens array. Through the technical solution of the embodiments of the present application, the test device at least includes: a light source module, a resolution module, an array moving module and a measuring module, wherein the resolution module is located between the light source module and the array moving module, and the array to be tested is placed on the array moving module; the light source module is used to provide an original light source; the resolution module is used to determine a periodic light source corresponding to the original light source according to the original light source; the array moving module is used to move the array to be tested so that the center of the light source module, the center of the resolution module, the center of the array to be tested and the center of the measuring module are located on the same straight line; the measuring module is used to take a picture of the imaging of the array to be tested to obtain a measurement image, and determine the modulation transfer function value corresponding to the array to be tested according to the measurement image. Through the test device for the modulation transfer function value of the self-focusing lens array provided by the embodiments of the present application, by adjusting the distance between the array to be tested and the measuring module, the imaging of the array to be tested is photographed and analyzed, thereby calculating the modulation transfer function value. Since the distance between the array to be tested and the measuring module can be adjusted arbitrarily as needed, the self-focusing lens array with a short focal length can be measured, and the test efficiency is high.

[0005] In a first aspect, some embodiments of the present application provide a test device for a modulation transfer function value of a self-focusing lens array, the test device comprising at least: a light source module, a resolution module, an array moving module and a measurement module, wherein the resolution module is located between the light source module and the array moving module, and an array to be tested is placed on the array moving module;

[0006] The light source module is used to provide an original light source;

[0007] The resolution module is used to determine a periodic light source corresponding to the original light source according to the original light source;

[0008] The array moving module is used to move the array to be measured so that the center of the light source module, the center of the resolution module, the center of the array to be measured and the center of the measurement module are located on the same straight line;

[0009] The measuring module is used to take a picture of the imaging of the array to be measured to obtain a measurement image, and determine the modulation transfer function value corresponding to the array to be measured according to the measurement image.

[0010] In some embodiments of the present application, the distance between the array to be tested and the measuring module is adjusted to take a picture of the imaging of the array to be tested, thereby calculating the modulation transfer function value. Since the distance between the array to be tested and the measuring module can be adjusted arbitrarily as needed, a self-focusing lens array with a short focal length can be measured, and the test efficiency is relatively high.

[0011] In some embodiments, the measurement module is specifically used to:

[0012] In the absence of light source, the environment and detection energy are calibrated to obtain the calibration value;

[0013] When the light source module emits light, acquiring a measurement image, and determining a measurement value according to the measurement image;

[0014] Determine the maximum light intensity and the minimum light intensity corresponding to the measured image according to the measured value and the calibrated value;

[0015] A modulation transfer function value at a working distance of the array to be measured is determined according to the maximum light intensity and the minimum light intensity.

[0016] Some embodiments of the present application calibrate the environment and the detection energy to obtain a calibration value, acquire a measurement image according to a preset light source, and calculate the modulation transfer function value at the working distance of the array to be measured, thereby reducing environmental interference and improving detection efficiency.

[0017] In some embodiments, the array moving module is specifically used to move the array to be measured from three different directions so that the center of the light source module, the center of the resolution module, the center of the array to be measured and the center of the measurement module are located on the same straight line.

[0018] Some embodiments of the present application use an array moving module to move the array to be tested in real time, ensuring that the array to be tested is moved from three different directions, so that the center of the light source module, the center of the resolution module, the center of the array to be tested and the center of the measurement module are located in the same straight line, thereby improving the accuracy of detection.

[0019] In some embodiments, the light source module is used to provide a monochromatic or polychromatic original light source.

[0020] In some embodiments of the present application, a monochromatic or polychromatic original light source may be provided. By providing a monochromatic light source, interference factors in detection may be reduced and detection accuracy may be improved.

[0021] In some embodiments, the resolution module includes at least a resolution grid plate, and the resolution grid plate is used to convert the original light source into a periodic light and dark stripe image.

[0022] Some embodiments of the present application can generate a clear image of the periodic frequency of the target to be detected by setting a resolution grid plate, which is convenient for calculating the modulation transfer function value.

[0023] In some embodiments, the measurement module at least includes a measurement unit and a moving unit, the moving unit is connected to the measurement unit, and the moving unit is used to control the movement of the measurement unit so that the array to be measured is located in the middle position between the resolution module and the measurement unit.

[0024] Some embodiments of the present application provide a moving unit that drives the measuring unit to move on the optical axis, thereby ensuring that the array to be measured is always within the working distance and ensuring the accuracy of the detection.

[0025] In some embodiments, the measuring unit includes at least one of a camera or a near-field analyzer.

[0026] The measurement in some embodiments of the present application may be performed by a camera or a near-field analyzer, which may obtain an imaged photo for energy or relative energy analysis.

[0027] In some embodiments, the testing device further comprises a remote terminal, wherein the remote terminal is connected to the measuring unit, and the remote terminal is used to control the movement of the measuring unit so that the array to be tested is located in the middle position between the resolution module and the measuring unit.

[0028] In some embodiments of the present application, by connecting the measuring unit to a remote terminal, the movement of the measuring unit can be controlled, thereby improving the movement efficiency of the measuring unit.

[0029] In some embodiments, the testing device further includes a homogenization module, the homogenization module is located between the light source module and the resolution module, and the homogenization module is used to homogenize the original light source.

[0030] Some embodiments of the present application perform homogenization processing on the original light source through a homogenization module to improve the accuracy of light source imaging.

[0031] In a second aspect, some embodiments of the present application provide a method for testing a modulation transfer function value of a self-focusing lens array, which is applied to a testing device for the modulation transfer function value of a self-focusing lens array described in any one of the first aspects, and the method comprises:

[0032] When the center of the light source module, the center of the resolution module, the center of the array to be measured and the center of the measurement module are located in the same straight line, and the array to be measured is located in the middle of the resolution module and the measurement module, photographing the imaging of the array to be measured to obtain a measurement image;

[0033] A modulation transfer function value corresponding to the array to be measured is determined according to the measurement image. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the technical solutions of some embodiments of the present application, the drawings required for use in some embodiments of the present application will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0035] Figure 1 It is a structural principle diagram of a test instrument in the prior art;

[0036] Figure 2 A schematic diagram of the structure of a test device for the modulation transfer function value of a self-focusing lens array provided in an embodiment of the present application;

[0037] Figure 3 A schematic diagram of the structure of another device for testing the modulation transfer function value of a self-focusing lens array provided in an embodiment of the present application;

[0038] The accompanying drawings are marked as follows:

[0039] 1—light source; 2—condenser; 3—variable filter; 4—variable slit; 5—collimator objective; 6—objective lens to be measured; 7—spatial frequency slit; 8—lens; 9—rotating grating scanner; 10—semi-reflective and semi-mirror lens; 11—visual observation mirror; 12—condenser; 13—photoelectric receiver. DETAILED DESCRIPTION

[0040] The technical solutions in some embodiments of the present application will be described below in conjunction with the drawings in some embodiments of the present application.

[0041] It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings. At the same time, in the description of this application, the terms "first", "second", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0042] In the prior art, when testing the objective lens, the following method is usually used: Figure 1 The test instrument shown includes: a light source 1, a condenser 2, a variable filter 3, a variable slit 4, a collimator objective 5, a measured objective 6, a spatial frequency slit 7, a lens 8, a rotating grating scanner 9, a semi-reflective semi-mirror 10, a visual observation mirror 11, a condenser 12 and a photoelectric receiver 13; in a specific implementation process, the measured objective 6 images the variable slit 4 on the rotating grating scanner 9, realizing relative scanning between the variable slit 4 and the rotating grating scanner 9, and the light flux of the effective scanning hole that changes with time is received by the photoelectric receiver 13 and converted into an electrical signal, thereby realizing frequency conversion.

[0043] Since the distance between the measured objective lens 6 and the photoelectric receiver 13 is very long, Figure 1The test instrument shown can be used to measure the objective lens with long focal length, certain aperture size and axisymmetric structure, but cannot measure the objective lens with short focal length, small aperture and asymmetric axis. In view of this, some embodiments of the present application provide a test device for the modulation transfer function value of a self-focusing lens array, the test device comprising: a light source module, a resolution module, an array moving module and a measuring module, wherein the resolution module is located between the light source module and the array moving module, and an array to be tested is placed on the array moving module; the light source module is used to provide an original light source; the resolution module is used to determine a periodic light source corresponding to the original light source based on the original light source; the array moving module is used to move the array to be tested so that the center of the light source module, the center of the resolution module, the center of the array to be tested and the center of the measuring module are located on the same straight line; the measuring module is used to take a picture of the imaging of the array to be tested to obtain a measurement image, and determine the modulation transfer function value corresponding to the array to be tested based on the measurement image. Through the test device for the modulation transfer function value provided by the embodiment of the present application, by adjusting the distance between the array to be tested and the measuring module, the imaging of the array to be tested is taken, thereby calculating the modulation transfer function value. Since the distance between the array to be tested and the measuring module can be adjusted arbitrarily as needed, a self-focusing lens array with a short focal length can be measured, and the test efficiency is high.

[0044] like Figure 2 As shown, an embodiment of the present application provides a test device for the modulation transfer function value of a self-focusing lens array, and the test device at least includes: a light source module 201, a resolution module 202, an array moving module 203 and a measurement module 204, wherein the resolution module 202 is located between the light source module 201 and the array moving module 203, and an array to be tested is placed on the array moving module;

[0045] The light source module 201 is used to provide an original light source;

[0046] Specifically, the original light source is a monochromatic light source, such as red, blue or green, and during the test, it can be switched as needed, or a complex color light, such as daily white light, can be used.

[0047] By setting a monochromatic light source, interference factors in detection can be reduced and the accuracy of detection can be improved.

[0048] The resolution module 202 is used to determine a periodic light source corresponding to the original light source according to the original light source;

[0049] Specifically, the resolution module includes at least a resolution grid plate, which is used to convert the original light source into a periodic light and dark stripe image. By setting the resolution grid plate to generate a periodic image, a clearer image can be generated, which is convenient for calculating the modulation transfer function value.

[0050] The array moving module 203 is used to move the array to be measured so that the center of the light source module, the center of the resolution module, the center of the array to be measured and the center of the measurement module are located on the same straight line;

[0051] Specifically, the array moving module is a three-dimensional moving device, which can move the array to be measured from three directions so that the array to be measured is located in the middle position between the resolution module and the measurement module, and the center of the light source module, the center of the resolution module, the center of the array to be measured and the center of the measurement module are located on the same straight line, for example, the midpoints are all located on the optical axis.

[0052] The array moving module is used to move the array to be tested in real time to ensure that the array to be tested is located in the middle of the resolution module and the measurement module, and the midpoint of each module is located on the optical axis, thereby improving the accuracy of detection.

[0053] According to the array to be tested with different focal lengths, the distance between the measurement module and the resolution module needs to be adjusted, and the array to be tested needs to be set in the middle position between the measurement module and the resolution module. Therefore, it is also necessary to use an array moving module to adjust the position of the array to be tested so that the array to be tested is located in the middle position between the measurement module and the resolution module.

[0054] The measurement module 204 is used to take a picture of the imaging of the array to be measured to obtain a measurement image, and determine the modulation transfer function value corresponding to the array to be measured according to the measurement image.

[0055] Optionally, the measuring module at least includes a measuring unit and a moving unit, the moving unit is connected to the measuring unit, and the moving unit is used to control the movement of the measuring unit so that the array to be measured is located in the middle position between the resolution module and the measuring unit.

[0056] The measuring unit includes at least one of a camera and a near-field analyzer.

[0057] The measuring unit in some embodiments of the present application may be a camera or a near-field analyzer, which may acquire an image to perform energy or relative energy analysis.

[0058] The moving unit is a manual moving device, such as a hand-cranked device, or a device that can drive the measuring unit to move. The moving unit drives the measuring unit to move on the optical axis to ensure that the measured array is always within the working distance, thereby ensuring the accuracy of the detection.

[0059] In order to improve the efficiency of manual driving, the test device also includes a remote terminal, wherein the remote terminal is connected to the measuring unit and is used to control the movement of the measuring unit so that the array to be tested is located in the middle position between the resolution module and the measuring unit.

[0060] By connecting the measuring unit to the remote terminal, the movement of the measuring unit can be controlled, thereby improving the movement efficiency of the measuring unit.

[0061] Based on the above embodiment, the measurement module is specifically used for:

[0062] In the absence of light source, the environment and detection energy are calibrated to obtain the calibration value;

[0063] When the light source module emits light, a measurement image is acquired, and a measurement value is determined according to the measurement image;

[0064] According to the measured value and the calibration value, the maximum value and the minimum value of the light intensity corresponding to the measured image are determined;

[0065] The modulation transfer function value at the working distance of the array to be measured is determined according to the maximum light intensity and the minimum light intensity.

[0066] Specifically, in the absence of a light source, the measurement module calibrates the environment and the detection energy to obtain a calibration value; the distance between the measurement module and the resolution module is set as the array working distance; the array to be measured is placed by the mobile platform to the middle position between the measurement module and the resolution module;

[0067] When the light source module emits light, the measurement module captures a measurement image of the array to be measured at this time, and obtains a measurement value in the measurement image according to the measurement image.

[0068] The measurement module subtracts the calibration value from the measurement value to obtain the calibrated measurement value, and determines the maximum light intensity and the minimum light intensity according to the calibrated measurement value. Specifically:

[0069] The Modulation Transfer Function (MTF) value is assumed to be 1 when the modulation index of the object plane before passing through the array is approximated by the formula MTF = (Imax - Imin) / (Imax + Imin) at a single frequency.

[0070] Among them, Imax is the maximum light intensity, and Imin is the minimum light intensity;

[0071] The above formula is used to obtain the modulation transfer function value of the array to be tested at the working distance and frequency. The modulation transfer function value can be used to judge the imaging quality of the array to be tested.

[0072] The embodiment of the present application calibrates the environment and the detection energy to obtain a calibration value, acquires a measurement image according to a preset light source, and calculates the modulation transfer function value at the working distance of the array to be measured, thereby reducing environmental interference and improving detection efficiency.

[0073] The testing device also includes a homogenization module, which is located between the light source module and the resolution module. The homogenization module is used to homogenize the original light source. The homogenization module is used to homogenize the original light source to improve the accuracy of light source imaging.

[0074] On the basis of the above-mentioned embodiment, the embodiment of the present application further provides a method for testing the modulation transfer function value of a self-focusing lens array, which is applied to the testing device for the modulation transfer function value of the self-focusing lens array, and the method comprises:

[0075] When the center of the light source module, the center of the resolution module, the center of the array to be measured and the center of the measurement module are located in the same straight line, and the array to be measured is located in the middle of the resolution module and the measurement module, take a picture of the imaging of the array to be measured to obtain a measurement image;

[0076] According to the measured image, the modulation transfer function value corresponding to the array to be measured is determined.

[0077] The test device for the modulation transfer function value provided in the embodiment of the present application has a simple structure and can obtain the value of the modulation transfer function MTF of a single frequency of interest without measuring the entire frequency space; it can be used to measure array products with short focal lengths, small clear apertures, small working distances, and non-axisymmetric structures. The test device for the modulation transfer function value provided in the embodiment of the present application has a greatly simplified structure, and the cost is only 1 / 5 to 1 / 10 of traditional measuring equipment. It can measure arrays with a single lens diameter of less than 1mm, or even 0.3mm, or even smaller, and can measure array products with a focal length of less than 1mm; it can measure the effect in actual small working distance scenarios, down to less than 1mm. The spatial frequency can be replaced with a target resolution board according to the use of interest, which is relatively convenient.

[0078] The present application provides a testing device and method for the modulation transfer function value of a self-focusing lens array, the testing device at least comprising: a light source module, a resolution module, an array moving module and a measuring module, wherein the resolution module is located between the light source module and the array moving module, and an array to be tested is placed on the array moving module; the light source module is used to provide an original light source; the resolution module is used to determine a periodic light source corresponding to the original light source based on the original light source; the array moving module is used to move the array to be tested so that the center of the light source module, the center of the resolution module, the center of the array to be tested and the center of the measuring module are located on the same straight line; the measuring module is used to take a picture of the imaging of the array to be tested to obtain a measurement image, and determine the modulation transfer function value corresponding to the array to be tested based on the measurement image. Through the testing device for the modulation transfer function value provided by the embodiment of the present application, by adjusting the distance between the array to be tested and the measuring module, the imaging of the array to be tested is photographed and analyzed, thereby calculating the modulation transfer function value. Since the distance between the array to be tested and the measuring module can be adjusted arbitrarily as needed, a self-focusing lens array with a short focal length can be measured, and the testing efficiency is high.

[0079] It should be noted that each implementable method in this embodiment may be implemented separately, or may be implemented in combination in any combination without conflict, and this application is not limited thereto.

[0080] The above are only embodiments of the present application and are not intended to limit the scope of protection of the present application. For those skilled in the art, the present application may have various changes and variations. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application should be included in the scope of protection of the present application. It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings.

[0081] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

[0082] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

Claims

1. A test device for the modulation transfer function value of a self-focusing lens array, characterized in that: The testing device at least comprises: a light source module, a resolution module, an array moving module and a measuring module, wherein the resolution module is located between the light source module and the array moving module, and an array to be tested is placed on the array moving module; The light source module is used to provide an original light source; The resolution module is used to determine a periodic light source corresponding to the original light source according to the original light source; The array moving module is used to move the array to be measured so that the center of the light source module, the center of the resolution module, the center of the array to be measured and the center of the measurement module are located on the same straight line; The measuring module is used to take a picture of the imaging of the array to be measured to obtain a measurement image, and determine the modulation transfer function value corresponding to the array to be measured according to the measurement image.

2. The test device for the modulation transfer function value of the self-focusing lens array according to claim 1, characterized in that: The measuring module is specifically used for: In the absence of light source, the environment and detection energy are calibrated to obtain the calibration value; When the light source module emits light, acquiring a measurement image, and determining a measurement value according to the measurement image; Determine the maximum light intensity and the minimum light intensity corresponding to the measured image according to the measured value and the calibrated value; A modulation transfer function value at a working distance of the array to be measured is determined according to the maximum light intensity and the minimum light intensity.

3. The test device for the modulation transfer function value of the self-focusing lens array according to claim 1, characterized in that: The array moving module is specifically used to move the array to be measured from three different directions so that the center of the light source module, the center of the resolution module, the center of the array to be measured and the center of the measurement module are located on the same straight line.

4. The test device for the modulation transfer function value of the self-focusing lens array according to claim 1, characterized in that: The light source module is used to provide a monochromatic or polychromatic original light source.

5. The test device for the modulation transfer function value of the self-focusing lens array according to claim 1, characterized in that: The resolution module at least includes a resolution grid plate, and the resolution grid plate is used to convert the original light source into a periodic light and dark stripe image.

6. The test device for the modulation transfer function value of the self-focusing lens array according to claim 1, characterized in that: The measuring module at least comprises a measuring unit and a moving unit, wherein the moving unit is connected to the measuring unit and is used to control the movement of the measuring unit so that the array to be measured is located in the middle position between the resolution module and the measuring unit.

7. The test device for the modulation transfer function value of the self-focusing lens array according to claim 6, characterized in that: The measuring unit includes at least one of a camera and a near-field analyzer.

8. The test device for the modulation transfer function value of the self-focusing lens array according to claim 7, characterized in that: The testing device further comprises a remote terminal, wherein the remote terminal is connected to the measuring unit and is used to control the movement of the measuring unit so that the array to be tested is located in the middle position between the resolution module and the measuring unit.

9. The test device for the modulation transfer function value of the self-focusing lens array according to claim 1, characterized in that: The testing device further comprises a homogenizing module, which is located between the light source module and the resolution module, and is used to homogenize the original light source.

10. A method for testing the modulation transfer function value of a self-focusing lens array, characterized in that: The method for testing the modulation transfer function value of the self-focusing lens array according to any one of claims 1 to 9 comprises: When the center of the light source module, the center of the resolution module, the center of the array to be measured and the center of the measurement module are located in the same straight line, and the array to be measured is located in the middle of the resolution module and the measurement module, photographing the imaging of the array to be measured to obtain a measurement image; A modulation transfer function value corresponding to the array to be measured is determined according to the measurement image.

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