A performance evaluation method and system for an optical lens

Abstract

The present invention belongs to the technical field of lens performance evaluation. The present invention provides a performance evaluation method and system for optical lenses, including: obtaining detection parameters of returned optical lenses, building an analysis library for returned optical lenses, performing weighted comprehensive analysis on the detection parameters of the returned optical lenses in the same batch, and determining normal optical lenses among the returned lenses in the same batch; performing MTF testing on all normal optical lenses in the returned optical lenses at different spatial frequencies, and evaluating whether the comprehensive performance of the normal optical lenses at different spatial frequencies is qualified; identifying the tangential arc imbalance frequency in the spatial frequency, and determining unqualified optical lenses among the normal optical lenses; the present invention focuses detection resources within the frequency detection range by analyzing the tangential arc imbalance frequency, optimizes the detection process for tangential testing and arc testing of subsequent batches of lenses, and reduces detection costs while ensuring detection quality.

Description

Technical Field

[0001] The present invention belongs to the technical field of lens performance evaluation, and in particular to a performance evaluation method and system for an optical lens. Background Art

[0002] As society develops, humanity's need to record and observe the world continues to grow. Optical lenses, at the heart of photographic equipment, focus light and produce sharp images, satisfying people's need to freeze moments and preserve authentic images. Through functions like magnification and focusing, optical lenses help scientists push the limits of observation, acquire more information, and advance scientific research.

[0003] Accurately evaluating the performance of optical lenses is crucial during their production and use. However, existing optical lens performance evaluation methods rely primarily on manual experience to determine lens quality, lacking scientific quantitative standards. These methods are highly subjective and prone to missing potential issues. Furthermore, performance testing for tangential and arc tests fails to focus testing resources within the frequency range, requiring indiscriminate testing of optical lenses across the entire spatial frequency range, resulting in high testing costs.

[0004] To this end, the present invention provides a method and system for evaluating the performance of an optical lens. Summary of the Invention

[0005] In order to make up for the deficiencies of the prior art, at least one technical problem raised in the background technology is solved.

[0006] In a first aspect, the present invention provides a method for evaluating the performance of an optical lens, comprising the following steps:

[0007] Obtain the inspection parameters of returned optical lenses, build an analysis library for returned optical lenses, perform weighted comprehensive analysis on the inspection parameters of returned optical lenses from the same batch, and identify normal optical lenses among the returned lenses from the same batch;

[0008] By performing MTF tests on all normal optical lenses returned to the factory at different spatial frequencies, we can evaluate whether the comprehensive performance of normal optical lenses at different spatial frequencies is qualified.

[0009] If the comprehensive performance evaluation of a normal optical lens at different spatial frequencies shows that it is qualified, extract all normal optical lenses that have qualified comprehensive performance evaluation, and perform tangential and arc tests at different spatial frequencies to identify the tangential and arc imbalance frequencies in the spatial frequencies, evaluate whether the lens imaging performance in the tangential and arc directions at different spatial frequencies is qualified, and determine the unqualified optical lenses among the normal optical lenses;

[0010] If the imaging performance in the tangential and arc directions at different spatial frequencies is unqualified, the tangential and arc imbalance frequencies of the unqualified optical lenses in the same batch are deduplicated, the frequency detection range and the tangential and arc test frequency priority table are determined, and the subsequent tangential and arc tests of the lenses in the same batch are optimized.

[0011] As a further embodiment of the present invention: the process of obtaining the risk level of the returned optical lens is as follows:

[0012] Based on the inspection parameters of the returned optical lens, a weighted comprehensive scoring method is used to determine the comprehensive appearance evaluation value of the returned optical lens. If the comprehensive appearance evaluation value is less than the comprehensive appearance evaluation threshold, the corresponding returned optical lens will be recorded as a normal optical lens.

[0013] As a further embodiment of the present invention: the specific process of evaluating the comprehensive performance of a normal optical lens at different spatial frequencies is as follows:

[0014] Extract all normal optical lenses from the returned optical lenses and perform MTF tests at different spatial frequencies to obtain the comprehensive MTF of normal optical lenses at different spatial frequencies. Analyze and obtain the comprehensive abnormal frequency number ratio and comprehensive abnormality degree ratio.

[0015] The comprehensive performance evaluation value is obtained by multiplying the comprehensive abnormality frequency ratio and the comprehensive abnormality degree ratio;

[0016] If the comprehensive performance evaluation value is less than the comprehensive performance evaluation threshold, it means that the comprehensive performance evaluation of the normal optical lens at different spatial frequencies is qualified.

[0017] As a further embodiment of the present invention: the method for obtaining the comprehensive abnormal frequency quantity ratio is:

[0018] If the integrated MFT at the current spatial frequency is greater than or equal to the integrated MTF standard value, the corresponding spatial frequency is recorded as an abnormal spatial frequency; the proportion of the abnormal spatial frequencies is calculated to obtain the integrated abnormal frequency ratio.

[0019] As a further embodiment of the present invention: the method for obtaining the comprehensive abnormality degree ratio is:

[0020] The difference between the integrated MTF corresponding to the abnormal spatial frequency and the integrated MTF standard value is taken as the absolute value to obtain the abnormal deviation value. The abnormal deviation values ​​corresponding to all abnormal spatial frequencies are summed and averaged to obtain the abnormal deviation mean. The integrated MTF standard values ​​corresponding to all abnormal spatial frequencies are summed and averaged to obtain the integrated MTF standard mean. The abnormal deviation mean is compared with the integrated MTF standard mean to obtain the comprehensive abnormality degree ratio.

[0021] As a further embodiment of the present invention: the specific process of identifying the arc imbalance frequency in the spatial frequency is:

[0022] Obtain the tangential MTF and arc MTF at different spatial frequencies, perform the difference processing on the tangential MTF and arc MTF at the current spatial frequency, and obtain the tangential arc difference value at the current spatial frequency. If the tangential arc difference value at the current spatial frequency is greater than or equal to the tangential arc difference threshold, the corresponding spatial frequency is recorded as the tangential arc imbalance frequency.

[0023] As a further embodiment of the present invention: the specific process of determining an unqualified optical lens among normal optical lenses is as follows:

[0024] The tangential MTF and arc MTF at different spatial frequencies are analyzed to obtain the tangential arc imbalance frequency ratio and the tangential arc difference degree value;

[0025] The arc cutting performance evaluation value is obtained by multiplying the arc cutting imbalance frequency ratio and the arc cutting difference degree value;

[0026] If the arc cutting performance evaluation value is greater than or equal to the arc cutting performance evaluation threshold, the corresponding normal optical lens will be recorded as an unqualified optical lens.

[0027] As a further embodiment of the present invention: the process of obtaining the arc cutting imbalance frequency ratio and the arc cutting difference value is as follows:

[0028] Count the number of tangential arc imbalance frequencies in the set spatial frequency, calculate the proportion of the number of tangential arc imbalance frequencies, and obtain the tangential arc imbalance frequency ratio;

[0029] The arc cutting difference values ​​corresponding to all arc cutting imbalance frequencies are summed and averaged to obtain the arc cutting difference mean value. The arc cutting difference mean value is then compared with the arc cutting difference threshold value to obtain the arc cutting difference degree value.

[0030] As a further embodiment of the present invention: the process of obtaining the frequency detection range and the arc-cutting test frequency priority table is as follows:

[0031] Extract all the arc imbalance frequencies from all unqualified optical lenses, remove duplicates, and extract the first arc imbalance frequency F among all the arc imbalance frequencies after removal of duplicates. min Unbalanced frequency F with the first arc in reverse order max , then the frequency detection range of subsequent batches for tangential test and arc test is [F min ,F max ];

[0032] Based on any arc-cutting imbalance frequency among all the arc-cutting imbalance frequencies after deduplication, calculate the proportion of unqualified optical lenses at the arc-cutting imbalance frequency; sort the proportion of unqualified optical lenses at all the arc-cutting imbalance frequencies from large to small to obtain the arc-cutting test frequency priority ranking table;

[0033] When performing performance testing on subsequent batches of optical lenses, tangential tests and arc tests are performed within the frequency detection range, and tangential tests and arc tests are performed on the optical lenses according to the tangential arc test frequency priority table.

[0034] In a second aspect, the present invention further provides a performance evaluation system for an optical lens, specifically comprising the following modules:

[0035] Lens differentiation module: obtains the test parameters of returned optical lenses, builds a returned optical lens analysis library, performs weighted comprehensive analysis on the test parameters of returned optical lenses from the same batch, and identifies normal optical lenses among the returned lenses from the same batch;

[0036] Comprehensive analysis module: By performing MTF tests on all normal optical lenses among the returned optical lenses at different spatial frequencies, the comprehensive performance of the normal optical lenses at different spatial frequencies is evaluated to see whether they are qualified;

[0037] Refinement Analysis Module: If the comprehensive performance evaluation of a normal optical lens at different spatial frequencies shows that it is qualified, extract all normal optical lenses that have qualified comprehensive performance evaluation, and perform tangential and arc tests at different spatial frequencies to identify the tangential and arc imbalance frequencies in the spatial frequencies. Then, evaluate whether the lens imaging performance in the tangential and arc directions at different spatial frequencies is qualified, and determine the unqualified optical lenses among the normal optical lenses.

[0038] Detection frequency screening module: If the imaging performance in the tangential and arc directions at different spatial frequencies is unqualified, the tangential and arc imbalance frequencies of the unqualified optical lenses in the same batch are deduplicated and analyzed to determine the frequency detection range and the tangential and arc test frequency priority table, and subsequent tangential and arc tests of the same batch of lenses are optimized.

[0039] The beneficial effects of the present invention are as follows:

[0040] 1. The present invention obtains the detection parameters of returned optical lenses, constructs an analysis library for returned optical lenses, performs weighted comprehensive analysis on the detection parameters of returned optical lenses from the same batch, and determines the normal optical lenses among the returned lenses from the same batch; performs MTF tests on all normal optical lenses among the returned optical lenses at different spatial frequencies, and evaluates whether the comprehensive performance of the normal optical lenses at different spatial frequencies is qualified; the present invention systematically obtains multi-dimensional data such as detection parameters, production information, usage scenarios and failure modes through a collection table, constructs a comprehensive and structured analysis library, distinguishes between normal-looking lenses and abnormal lenses among returned optical lenses, performs MTF tests on normal lenses at multiple spatial frequencies, and realizes a comprehensive analysis of the comprehensive performance of the lenses.

[0041] 2. Based on the fact that normal optical lenses perform well in the comprehensive performance evaluation at different spatial frequencies, the present invention extracts all normal optical lenses that perform well in the comprehensive performance evaluation, performs tangential and arc tests at different spatial frequencies, identifies the tangential and arc imbalance frequencies in the spatial frequencies, evaluates whether the lens imaging performance in the tangential and arc directions at different spatial frequencies is qualified, and determines unqualified optical lenses among the normal optical lenses; if the imaging performance in the tangential and arc directions at different spatial frequencies is unqualified, the tangential and arc imbalance frequencies of unqualified optical lenses in the same batch are deduplicated, a frequency detection range and a tangential test frequency priority table are determined, and subsequent lenses in the same batch are optimized by performing tangential and arc tests; the present invention compares the tangential MTF with the arc MTF to identify the tangential imbalance frequencies, locate the defects in the tangential and arc imaging performance of the lens at specific spatial frequencies, further refine the performance evaluation dimensions, analyze the tangential imbalance frequencies, focus detection resources within the frequency detection range, optimize the tangential and arc test detection processes for subsequent batches of lenses, and reduce detection costs while ensuring detection quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] The present invention will be further described below with reference to the accompanying drawings.

[0043] Figure 1 This is a flowchart of the steps of a performance evaluation method for an optical lens according to an embodiment of the present invention;

[0044] Figure 2 This is a system block diagram of a performance evaluation system for an optical lens according to an embodiment of the present invention. DETAILED DESCRIPTION

[0045] In order to make the technical means, creative features, objectives and effects achieved by the present invention easier to understand, the present invention is further described below in conjunction with specific implementation methods.

[0046] Example 1

[0047] See also Figure 1 As shown, a performance evaluation method for an optical lens according to an embodiment of the present invention includes the following steps:

[0048] Step 1: Obtain the test parameters of the returned optical lenses, build an analysis library for the returned optical lenses, perform a weighted comprehensive analysis on the test parameters of the returned optical lenses from the same batch, and identify the normal optical lenses among the returned lenses from the same batch;

[0049] Obtain the inspection parameters of each returned optical lens through the returned optical lens collection table, where the inspection parameters include but are not limited to the barrel size deviation, lens installation coaxiality, and thread wear degree;

[0050] Collect the production information (model, batch, production time), usage scenarios (high / low temperature environment, high frequency vibration, high humidity, etc.), and failure modes (blurred imaging, abnormal light spot, mechanical jamming, etc.) of the returned optical lenses;

[0051] Clean noise and outliers (such as obviously erroneous test data), normalize feature parameters to the range of [0, 1] through Min-Max normalization, and use MySQL to store data in separate tables (for example, by "lens type + expiration year") to build an analysis library for returned optical lenses.

[0052] Extract the returned optical lenses of the same batch from the returned optical lens analysis library, and calculate the comprehensive appearance evaluation value of the returned optical lenses of the same batch based on the test parameters of the returned optical lenses;

[0053] Specifically, the process of obtaining the comprehensive appearance evaluation value is as follows:

[0054] Use the weighted comprehensive scoring method to determine the comprehensive appearance evaluation value GX of the returned optical lens. The specific formula is: ,in, is the weight of the i-th detection parameter. The weight distribution is set by those skilled in the art based on industry experience. is the normalized value of the i-th detection parameter, and n represents the total number of detection parameters;

[0055] It is understandable that the comprehensive appearance evaluation value represents whether the returned optical lens has a normal appearance;

[0056] In some embodiments, the comprehensive appearance evaluation value is compared with the comprehensive appearance evaluation threshold. The specific comparison process is:

[0057] If the comprehensive appearance evaluation value is greater than or equal to the comprehensive appearance evaluation threshold, the corresponding returned optical lens will be recorded as an abnormal optical lens;

[0058] If the comprehensive appearance evaluation value is less than the comprehensive appearance evaluation threshold, the corresponding returned optical lens will be recorded as a normal optical lens;

[0059] Step 2: Perform MTF tests on all normal optical lenses in the returned optical lenses at different spatial frequencies to evaluate whether the comprehensive performance of the normal optical lenses at different spatial frequencies is qualified;

[0060] Extract all normal optical lenses from the returned optical lenses and perform MTF tests at different spatial frequencies. Based on any normal optical lens, obtain the comprehensive MTF at different spatial frequencies.

[0061] Based on any spatial frequency, compare the comprehensive MTF at the current spatial frequency with the MTF standard value:

[0062] If the integrated MFT at the current spatial frequency is greater than or equal to the integrated MTF standard value, the corresponding spatial frequency is recorded as an abnormal spatial frequency;

[0063] If the integrated MFT at the current spatial frequency is less than the integrated MTF standard value, the corresponding spatial frequency is recorded as the normal spatial frequency;

[0064] It should be noted that the standard value of comprehensive MTF is set by those skilled in the art based on historical experience;

[0065] The specific process of obtaining the comprehensive MTF at different spatial frequencies is:

[0066] According to the normal optical lens, place it in the collimated light path between the light source system and the lens to be tested, so that the pattern of the resolution plate is clearly imaged on the imaging detector. Set different spatial frequencies to be tested through the control panel, such as 10lp / mm, 20lp / mm, 30lp / mm, 50lp / mm, and 100lp / mm;

[0067] For each set spatial frequency, an imaging detector is used to collect the image of the resolution plate after it is imaged by the tested lens, and the image is preprocessed;

[0068] The comprehensive edge spread function ESF is extracted from the preprocessed image, and the comprehensive line spread function LSF is obtained by taking the derivative of the comprehensive edge spread function ESF. The comprehensive line spread function LSF is subjected to one-dimensional Fourier transform, modulo and normalization to obtain the comprehensive MTF corresponding to each spatial frequency. The specific formula is:

[0069]

[0070] Where f represents the spatial frequency, Indicates the comprehensive MTF corresponding to the spatial frequency, express The modulus of the Fourier transform at frequency f is, express The Fourier transform value at spatial frequency f = 0;

[0071] Count the number of abnormal spatial frequencies in the set spatial frequencies, calculate the proportion of the number of abnormal spatial frequencies, and obtain the comprehensive abnormal frequency ratio;

[0072] Perform difference processing on the integrated MTF corresponding to the abnormal spatial frequency and the integrated MTF standard value, and take the absolute value of the difference to obtain the abnormal deviation value, sum and average the abnormal deviation values ​​corresponding to all abnormal spatial frequencies to obtain the abnormal deviation mean, sum and average the integrated MTF standard values ​​corresponding to all abnormal spatial frequencies to obtain the integrated MTF standard mean, perform ratio processing on the abnormal deviation mean and the integrated MTF standard mean to obtain the comprehensive abnormality degree ratio;

[0073] The comprehensive performance evaluation value is obtained by multiplying the comprehensive abnormality frequency ratio and the comprehensive abnormality degree ratio;

[0074] In some embodiments, the comprehensive performance evaluation value is compared with the comprehensive performance evaluation threshold. The specific comparison process is:

[0075] If the comprehensive performance evaluation value is greater than or equal to the comprehensive performance evaluation threshold, it means that the comprehensive performance evaluation of the normal optical lens at different spatial frequencies is unqualified;

[0076] If the comprehensive performance evaluation value is less than the comprehensive performance evaluation threshold, it means that the comprehensive performance evaluation of the normal optical lens at different spatial frequencies is qualified;

[0077] The technical implementation scheme of the present invention is as follows: obtaining the detection parameters of returned optical lenses, constructing an analysis library of returned optical lenses, performing weighted comprehensive analysis on the detection parameters of the returned optical lenses of the same batch, and determining the normal optical lenses among the returned lenses of the same batch; by performing MTF tests on all normal optical lenses in the returned optical lenses at different spatial frequencies, evaluating whether the comprehensive performance of the normal optical lenses at different spatial frequencies is qualified; the present invention systematically obtains multi-dimensional data such as detection parameters, production information, usage scenarios and failure modes through a collection table, constructs a comprehensive and structured analysis library, distinguishes between normal-looking lenses and abnormal lenses among the returned optical lenses, performs MTF tests on the normal lenses at multiple spatial frequencies, and realizes a comprehensive analysis of the comprehensive performance of the lenses.

[0078] Example 2

[0079] See also Figure 1 As shown, a performance evaluation method for an optical lens according to an embodiment of the present invention includes the following steps:

[0080] Step 3: If the comprehensive performance evaluation of a normal optical lens at different spatial frequencies shows that it is qualified, extract all normal optical lenses that have passed the comprehensive performance evaluation and perform tangential and arc tests at different spatial frequencies to identify the tangential and arc imbalance frequencies in the spatial frequencies. Then, evaluate whether the lens imaging performance in the tangential and arc directions at different spatial frequencies is qualified, and determine the unqualified optical lenses among the normal optical lenses.

[0081] All normal optical lenses that fail the comprehensive performance evaluation are subjected to tangential testing. The specific process is as follows:

[0082] Use the optical design software Zemax to determine the field of view coordinates of the lens (polar coordinates: radius r, angle θ), define the tangent direction of each field of view point (perpendicular to the direction of the principal ray, parallel to the θ direction), and adjust the detector coordinate system so that the pixel row is aligned with the tangent direction of the lens;

[0083] Mount the edge target on a rotating stage and rotate it until it is strictly aligned with the tangential direction of the current field of view point;

[0084] For example, if the field point is located at (r, θ = 45°), the tangent direction is the tangent direction of θ = 45°, and the blade edge needs to be rotated to 45°;

[0085] The collimator projects the edge target, the lens under test forms an image of it, and the detector collects the image;

[0086] Extract the grayscale distribution of the edge in the direction perpendicular to the tangential direction to obtain the arc edge diffusion function. Derivative the arc edge diffusion function to obtain the tangential line diffusion function. Perform Fourier transform on the tangential line diffusion function, take the modulus and normalize it to obtain the tangential MTF.

[0087] All normal optical lenses that fail the comprehensive performance evaluation are subjected to arc testing. The specific process is as follows:

[0088] Use the optical design software Zemax to determine the field of view coordinates of the lens (polar coordinates: radius r, angle θ), define the arc direction of each field point (along the direction of the principal ray, radial r), and adjust the detector coordinate system so that the pixel columns are aligned with the arc direction of the lens;

[0089] Mount the edge target on a rotating platform and rotate it until it is strictly aligned with the arc direction of the current field of view point;

[0090] Conduct tangential testing to ensure the detector is collecting data in the correct direction;

[0091] The grayscale distribution of the blade edge is extracted along the direction perpendicular to the arc direction to obtain the sagittal edge diffusion function. The sagittal edge diffusion function is differentiated to obtain the arcuate line diffusion function. The arcuate line diffusion function is Fourier transformed, modulo-normalized and obtained as the arcuate MTF.

[0092] Perform the difference processing between the tangential MTF and the arc MTF at the current spatial frequency to obtain the tangential arc difference value at the current spatial frequency;

[0093] It should be noted that the tangent arc difference value at the current spatial frequency is helpful in determining whether the optical lens meets the standard at a specific spatial frequency, and thus evaluating the performance of the optical lens;

[0094] If the tangential arc difference value at the current spatial frequency is less than the tangential arc difference threshold, it means that the performance evaluation of the normal optical lens at the current spatial frequency is qualified, and the corresponding spatial frequency is recorded as the tangential arc balance frequency;

[0095] If the tangential arc difference value at the current spatial frequency is greater than or equal to the tangential arc difference threshold, it means that the performance evaluation of the normal optical lens at the current spatial frequency is unqualified, and the corresponding spatial frequency is recorded as the tangential arc imbalance frequency;

[0096] Count the number of tangential arc imbalance frequencies in the set spatial frequency, calculate the proportion of the number of tangential arc imbalance frequencies, and obtain the tangential arc imbalance frequency ratio;

[0097] The arc cutting difference values ​​corresponding to all arc cutting imbalance frequencies are summed and averaged to obtain the arc cutting difference mean value, and the arc cutting difference mean value is compared with the arc cutting difference threshold value to obtain the arc cutting difference degree value;

[0098] The arc cutting performance evaluation value is obtained by multiplying the arc cutting imbalance frequency ratio and the arc cutting difference degree value;

[0099] In some embodiments, the arc cutting performance evaluation value is compared with the arc cutting performance evaluation threshold, and the specific comparison process is:

[0100] If the arc cutting performance evaluation value is greater than or equal to the arc cutting performance evaluation threshold, the imaging performance of the lens in the tangential direction and arc direction at different spatial frequencies is unqualified, and the corresponding normal optical lens is recorded as an unqualified optical lens;

[0101] If the arc cutting performance evaluation value is less than the arc cutting performance evaluation threshold, the imaging performance of the lens in the tangential direction and the arc direction at different spatial frequencies is qualified, and the corresponding normal optical lens is recorded as a qualified optical lens;

[0102] Step 4: If the imaging performance in the tangential and arc directions at different spatial frequencies is unqualified, perform a deduplication analysis on the tangential and arc imbalance frequencies of the unqualified optical lenses from the same batch, determine the frequency detection range and the tangential and arc test frequency priority table, and perform tangential and arc test optimization on subsequent lenses from the same batch;

[0103] Extract all the tangential arc imbalance frequencies from the unqualified optical lens, remove duplicate tangential arc imbalance frequencies from all the unqualified optical lenses, and integrate all the deduplicated tangential arc imbalance frequencies into a tangential arc imbalance frequency set:

[0104] Sort the arc-cutting imbalance frequencies in the arc-cutting imbalance frequency set from small to large to obtain an arc-cutting imbalance frequency sorting table, and extract the arc-cutting imbalance frequency F that is first in the order in the arc-cutting imbalance frequency table. min Unbalanced frequency F with the first arc in reverse order max , then the frequency detection range of subsequent batches for tangential test and arc test is [F min ,F max ];

[0105] Based on any arc imbalance frequency in the arc imbalance frequency sorting table, count the number of unqualified optical lenses at the arc imbalance frequency, and calculate the proportion of unqualified optical lenses at the arc imbalance frequency;

[0106] Sort the proportion of unqualified optical lenses at all arc-cutting imbalance frequencies from large to small to obtain an arc-cutting test frequency priority table;

[0107] When performing performance testing on subsequent batches of optical lenses, perform tangential and arc tests within the frequency testing range, and perform tangential and arc tests on the optical lenses according to the tangential and arc test frequency priority table;

[0108] It is understandable that by analyzing unqualified optical lenses to determine the frequency detection range for tangential and arc tests of subsequent batches of lenses, indiscriminate testing of the entire frequency band can be avoided. Instead, the performance of the optical lens can be tested and evaluated for tangential and arc tests within the frequency detection range, ensuring that testing resources are concentrated in the frequency detection range that has a greater impact on image quality, thereby effectively improving the efficiency of optical lens performance testing.

[0109] The technical solution of this embodiment is as follows: if a normal optical lens passes the comprehensive performance evaluation at different spatial frequencies, all normal optical lenses that pass the comprehensive performance evaluation are extracted and subjected to tangential and arc tests at different spatial frequencies. The tangential and arc imbalance frequencies in the spatial frequencies are identified, and the lens imaging performance in the tangential and arc directions at different spatial frequencies is evaluated to determine whether the lens is qualified, thereby determining unqualified optical lenses among the normal optical lenses. If the imaging performance in the tangential and arc directions at different spatial frequencies is unqualified, a deduplication analysis is performed on the tangential and arc imbalance frequencies of unqualified optical lenses from the same batch to determine the frequency detection range and a tangential and arc test frequency priority table, and tangential and arc tests are optimized for subsequent lenses from the same batch. The present invention compares the tangential MTF with the arc MTF to identify the tangential and arc imbalance frequencies, locate defects in the lens' tangential and arc imaging performance at specific spatial frequencies, further refine the performance evaluation dimensions, analyze the tangential imbalance frequencies, focus testing resources within the frequency detection range, and optimize the tangential and arc tests for subsequent batches of lenses, thereby ensuring testing quality while reducing testing costs.

[0110] Example 3

[0111] See also Figure 2 As shown, a performance evaluation system for an optical lens according to an embodiment of the present invention includes the following modules:

[0112] Lens differentiation module: obtains the test parameters of returned optical lenses, builds a returned optical lens analysis library, performs weighted comprehensive analysis on the test parameters of returned optical lenses from the same batch, and identifies normal optical lenses among the returned lenses from the same batch;

[0113] Comprehensive analysis module: By performing MTF tests on all normal optical lenses among the returned optical lenses at different spatial frequencies, the comprehensive performance of the normal optical lenses at different spatial frequencies is evaluated to see whether they are qualified;

[0114] Refinement Analysis Module: If the comprehensive performance evaluation of a normal optical lens at different spatial frequencies shows that it is qualified, extract all normal optical lenses that have qualified comprehensive performance evaluation, and perform tangential and arc tests at different spatial frequencies to identify the tangential and arc imbalance frequencies in the spatial frequencies. Then, evaluate whether the lens imaging performance in the tangential and arc directions at different spatial frequencies is qualified, and determine the unqualified optical lenses among the normal optical lenses.

[0115] Detection frequency screening module: If the imaging performance in the tangential and arc directions at different spatial frequencies is unqualified, the tangential and arc imbalance frequencies of the unqualified optical lenses in the same batch are deduplicated and analyzed to determine the frequency detection range and the tangential and arc test frequency priority table, and subsequent tangential and arc tests of the same batch of lenses are optimized.

[0116] The basic principles, main features, and advantages of the present invention are shown and described above. Those skilled in the art should understand that the present invention is not limited to the foregoing embodiments. The foregoing embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and modifications are intended to fall within the scope of the present invention. The scope of protection claimed in the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for evaluating the performance of an optical lens, characterized in that: The following steps are involved: Obtain the inspection parameters of returned optical lenses, build an analysis library for returned optical lenses, perform weighted comprehensive analysis on the inspection parameters of returned optical lenses from the same batch, and identify normal optical lenses among the returned lenses from the same batch; By performing MTF tests on all normal optical lenses returned to the factory at different spatial frequencies, we can evaluate whether the comprehensive performance of normal optical lenses at different spatial frequencies is qualified. If the comprehensive performance evaluation of a normal optical lens at different spatial frequencies shows that it is qualified, extract all normal optical lenses that have qualified comprehensive performance evaluation, and perform tangential and arc tests at different spatial frequencies to identify the tangential and arc imbalance frequencies in the spatial frequencies, evaluate whether the lens imaging performance in the tangential and arc directions at different spatial frequencies is qualified, and determine the unqualified optical lenses among the normal optical lenses; If the imaging performance in the tangential and arc directions at different spatial frequencies is unqualified, the tangential and arc imbalance frequencies of the unqualified optical lenses in the same batch are deduplicated, the frequency detection range and the tangential and arc test frequency priority table are determined, and the subsequent tangential and arc tests of the lenses in the same batch are optimized.

2. The method for evaluating the performance of an optical lens according to claim 1, wherein: The process of obtaining the risk level of the returned optical lens is as follows: Based on the inspection parameters of the returned optical lens, a weighted comprehensive scoring method is used to determine the comprehensive appearance evaluation value of the returned optical lens. If the comprehensive appearance evaluation value is less than the comprehensive appearance evaluation threshold, the corresponding returned optical lens will be recorded as a normal optical lens.

3. The method for evaluating the performance of an optical lens according to claim 2, wherein: The specific process of evaluating the comprehensive performance of a normal optical lens at different spatial frequencies is as follows: Extract all normal optical lenses from the returned optical lenses and perform MTF tests at different spatial frequencies to obtain the comprehensive MTF of normal optical lenses at different spatial frequencies. Analyze and obtain the comprehensive abnormal frequency number ratio and comprehensive abnormality degree ratio. The comprehensive performance evaluation value is obtained by multiplying the comprehensive abnormality frequency ratio and the comprehensive abnormality degree ratio; If the comprehensive performance evaluation value is less than the comprehensive performance evaluation threshold, it means that the comprehensive performance evaluation of the normal optical lens at different spatial frequencies is qualified.

4. The method for evaluating the performance of an optical lens according to claim 3, wherein: The method for obtaining the comprehensive abnormal frequency ratio is as follows: If the integrated MFT at the current spatial frequency is greater than or equal to the integrated MTF standard value, the corresponding spatial frequency is recorded as an abnormal spatial frequency; the proportion of the abnormal spatial frequencies is calculated to obtain the integrated abnormal frequency ratio.

5. The method for evaluating the performance of an optical lens according to claim 4, wherein: The comprehensive abnormality degree ratio is obtained as follows: The difference between the integrated MTF corresponding to the abnormal spatial frequency and the integrated MTF standard value is taken as the absolute value to obtain the abnormal deviation value. The abnormal deviation values ​​corresponding to all abnormal spatial frequencies are summed and averaged to obtain the abnormal deviation mean. The integrated MTF standard values ​​corresponding to all abnormal spatial frequencies are summed and averaged to obtain the integrated MTF standard mean. The abnormal deviation mean is compared with the integrated MTF standard mean to obtain the comprehensive abnormality degree ratio.

6. The method for evaluating the performance of an optical lens according to claim 5, wherein: The specific process of identifying the tangential arc imbalance frequency in the spatial frequency is as follows: Obtain the tangential MTF and arc MTF at different spatial frequencies, perform the difference processing on the tangential MTF and arc MTF at the current spatial frequency, and obtain the tangential arc difference value at the current spatial frequency. If the tangential arc difference value at the current spatial frequency is greater than or equal to the tangential arc difference threshold, the corresponding spatial frequency is recorded as the tangential arc imbalance frequency.

7. The method for evaluating the performance of an optical lens according to claim 6, wherein: The specific process of determining an unqualified optical lens among normal optical lenses is as follows: The tangential MTF and arc MTF at different spatial frequencies are analyzed to obtain the tangential arc imbalance frequency ratio and the tangential arc difference degree value; The arc cutting performance evaluation value is obtained by multiplying the arc cutting imbalance frequency ratio and the arc cutting difference degree value; If the arc cutting performance evaluation value is greater than or equal to the arc cutting performance evaluation threshold, the corresponding normal optical lens will be recorded as an unqualified optical lens.

8. The method for evaluating the performance of an optical lens according to claim 7, wherein: The process of obtaining the arc cutting imbalance frequency ratio and the arc cutting difference value is as follows: Count the number of tangential arc imbalance frequencies in the set spatial frequency, calculate the proportion of the number of tangential arc imbalance frequencies, and obtain the tangential arc imbalance frequency ratio; The arc cutting difference values ​​corresponding to all arc cutting imbalance frequencies are summed and averaged to obtain the arc cutting difference mean value. The arc cutting difference mean value is then compared with the arc cutting difference threshold value to obtain the arc cutting difference degree value.

9. The method for evaluating the performance of an optical lens according to claim 8, wherein: The process of obtaining the frequency detection range and the arc-cutting test frequency priority table is as follows: Extract all the arc imbalance frequencies from all unqualified optical lenses, remove duplicates, and extract the first arc imbalance frequency F among all the arc imbalance frequencies after removal of duplicates. min Unbalanced frequency F with the first arc in reverse order max , then the frequency detection range of subsequent batches for tangential test and arc test is [F min ,F max ]; Based on any arc imbalance frequency among all the arc imbalance frequencies after deduplication, calculate the proportion of unqualified optical lenses at the arc imbalance frequency; Sort the proportion of unqualified optical lenses at all arc-cutting imbalance frequencies from large to small to obtain an arc-cutting test frequency priority table; When performing performance testing on subsequent batches of optical lenses, tangential tests and arc tests are performed within the frequency detection range, and tangential tests and arc tests are performed on the optical lenses according to the tangential arc test frequency priority table.

10. A performance evaluation system for an optical lens, characterized in that: The system is used to execute the method according to any one of claims 1 to 9, and the system includes the following modules: Lens differentiation module: obtains the test parameters of returned optical lenses, builds a returned optical lens analysis library, performs weighted comprehensive analysis on the test parameters of returned optical lenses from the same batch, and identifies normal optical lenses among the returned lenses from the same batch; Comprehensive analysis module: By performing MTF tests on all normal optical lenses among the returned optical lenses at different spatial frequencies, the comprehensive performance of the normal optical lenses at different spatial frequencies is evaluated to see whether they are qualified; Refinement Analysis Module: If the comprehensive performance evaluation of a normal optical lens at different spatial frequencies shows that it is qualified, extract all normal optical lenses that have qualified comprehensive performance evaluation, and perform tangential and arc tests at different spatial frequencies to identify the tangential and arc imbalance frequencies in the spatial frequencies. Then, evaluate whether the lens imaging performance in the tangential and arc directions at different spatial frequencies is qualified, and determine the unqualified optical lenses among the normal optical lenses. Detection frequency screening module: If the imaging performance in the tangential and arc directions at different spatial frequencies is unqualified, the tangential and arc imbalance frequencies of the unqualified optical lenses in the same batch are deduplicated and analyzed to determine the frequency detection range and the tangential and arc test frequency priority table, and subsequent tangential and arc tests of the same batch of lenses are optimized.

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