Optical lens focus consistency detection method and device

Abstract

The invention discloses an optical lens focus consistency detection method and device, and the method comprises the steps: setting a reference light spot size and a light spot change interval according to the size of a focus light spot of a to-be-detected optical lens sample; respectively moving the light spot analyzer along the first direction and the second direction of the optical axis of the optical lens, collecting the size and the position of the light spot in the light spot change interval, calculating the focal length D0 of the to-be-detected lens sample and the focal length Dn of the to-be-detected lens, comparing the focal length D0 of the to-be-detected lens sample with the focal length Dn of the to-be-detected lens, and analyzing and verifying the focal length consistency of the to-be-detected lens. The above method can effectively avoid the problem of a focal depth section near the focus, and greatly improves the detection precision.

Description

Technical Field

[0001] The present invention relates to the technical field of optical lens detection, and more particularly, to a method and device for detecting the focus consistency of optical lenses. Background Art

[0002] In fiber output laser processing applications, a laser processing head usually consists of multiple groups of optical lenses and protective mirrors, and these optical lenses themselves have a certain focal length. However, in mass production, for optical lenses from different batches and different supply sources, the problem of focal length consistency differences is relatively common; in addition, although the complex surface shape design of aspherical optical lenses can improve optical performance, its processing and measurement difficulties are also higher, resulting in more common problems of focal length consistency differences for aspherical optical lenses. Due to the above problems, there are differences in the consistency of the light output focus of the laser processing head.

[0003] The focal length consistency error of optical lenses mainly comes from multiple dimensions such as the surface shape parameters of the lens surface, thickness dimensions, refractive index, etc. For example, the surface shape parameters of an optical lens (such as the radius of curvature, PV value of the surface shape) will affect the focusing effect of light, while the central thickness and refractive index of the lens directly affect the accuracy of the focal length.

[0004] Currently, in the parameter control and detection methods for optical lenses, non-contact detection techniques are widely used to avoid damaging the lens surface. For example, an interferometer can be used to detect the surface shape parameters of the lens surface, while a vision-based focal length detector can be used to detect the focal length. However, the interferometer cannot detect and control all the parameters that cause focus deviation of the optical lens one by one, and other instruments are needed for assistance; due to reasons such as depth of field, the accuracy of the vision-based focal length detector is poor, and for the lenses of a fiber output laser processing head, it is not sufficient to meet the accuracy requirements of thousandths. In summary, the existing technologies still have deficiencies in measurement accuracy and repeatability, especially in high-precision laser processing applications.

[0005] Therefore, how to control the focal length difference of optical lenses through an efficient and high-precision detection method has become an important research direction in the field of laser processing. Summary of the Invention

[0006] The purpose of the present invention is to provide a method for detecting the focus consistency of optical lenses, including the steps of:

[0007] S1: According to the size R of the focus spot of the lens sample to be detected, set the reference spot size d and the spot change interval;

[0008] S2: Place the lens sample to be detected in the system to be detected, and move the spot analyzer for debugging;

[0009] S3: Move the spot analyzer along the first direction of the optical axis of the lens sample to be inspected for detection, collect and record the first spot size R0 located in the spot change interval and the corresponding first position information N0; move the spot analyzer along the second direction of the optical axis of the lens sample to be inspected for detection, collect and record the second spot size S0 located in the spot change interval and the corresponding second position information M0;

[0010] S4: Calculate the focal length D0 of the lens sample to be inspected through the first position information N0 and the second position information M0;

[0011] S5: Place the lens to be inspected in the inspection system, fix the spot analyzer at the focal length D0 position of the lens sample to be inspected; repeat steps S3 - S4 to detect and calculate the focal length Dn of the lens to be inspected;

[0012] S6: Compare the focal length D0 of the lens sample to be inspected with the focal length Dn of the lens to be inspected, and analyze and verify the focal length consistency of the lens to be inspected.

[0013] Further, in step S1, the value range of the spot change interval is [d×(1 - k%), d×(1 + k%)], the value range of k is 0.1 - 2, where d is the reference spot size of the lens sample to be inspected; the reference spot size d of the lens sample to be inspected and the focal spot size R of the lens sample to be inspected satisfy d≥W×R, and the value range of W is 1.2 - 10.

[0014] Further, step S2 includes: S21: If the spot analyzer detects that the spot size of the lens sample to be inspected exceeds the set magnitude, adjust the position of the spot analyzer to adjust the spot size below the set magnitude to complete the first debugging of the spot analyzer;

[0015] S22: Move the spot analyzer to traverse the spot sizes near the focal spot of the lens sample to be inspected, and the spot analyzer is fixedly arranged near the focal spot to complete the second debugging of the spot analyzer.

[0016] Further, step S3 includes: S31: Move the spot analyzer along the first direction of the optical axis of the lens sample to be inspected for detection. When the spot analyzer detects that the spot size is within the spot change interval, pause for S seconds, calculate the average spot size according to the uploaded spot size and record it as the first spot size R0, and record the uploaded position information as the first position information N0;

[0017] S32: Move the spot analyzer along the second direction of the optical axis of the lens sample to be detected for detection. When the spot analyzer detects that the spot size is within the spot change interval, pause for S seconds. Calculate the average spot size based on the uploaded spot size and record it as the second spot size S0, and record the uploaded position information as the first position information M0.

[0018] Further, step S4 specifically includes: calculating the focal length D0 of the lens sample to be detected, where the first position information N0, the second position information M0, and the focal length D0 of the lens sample to be detected satisfy:

[0019]

[0020] Further, in step S31, if the first spot size R0 is not within the spot change interval, use a fixed step size progressive compensation to adjust the position of the spot analyzer;

[0021] In step S32, if the second spot size S0 is not within the spot change interval, use a fixed step size progressive compensation to adjust the position of the spot analyzer.

[0022] Further, in step S31, if the first spot size R0 is not within the spot change interval, the specific method of using a fixed step size progressive compensation to adjust the position of the spot analyzer is:

[0023] S311: If the first spot size R0 < d×(1 - k%), along the first direction of the optical axis of the lens sample to be detected, use a fixed step size progressive compensation to adjust the position of the spot analyzer until the R0 is within the spot change interval;

[0024] S312: If the first spot size R0 > d×(1 - k%), along the reverse direction of the first direction of the optical axis of the lens sample to be detected, use a fixed step size progressive compensation to adjust the position of the spot analyzer until the R0 is within the spot change interval;

[0025] In step S32, if the second spot size S0 is not within the spot change interval, the specific method of using a fixed step size progressive compensation to adjust the position of the spot analyzer is:

[0026] S321: If the second spot size S0 < d×(1 - k%), along the second direction of the optical axis of the lens sample to be detected, use a fixed step size progressive compensation to adjust the position of the spot analyzer until the S0 is within the spot change interval;

[0027] S322: If the size S0 of the second light spot > d×(1 - k%), along the reverse direction of the second direction of the optical axis of the lens sample to be inspected, use a fixed step size to gradually compensate and adjust the position of the light spot analyzer until S0 is within the light spot change range.

[0028] Further, in step S6, if Dn satisfies: |D0 - Dn| ≤ F×t‰, it indicates that the focus consistency of the lens to be inspected is qualified; F is the focal length of the lens sample to be inspected, and the value range of t is 0.1 - 10.

[0029] Further, when the lens to be inspected is a positive lens, F is the effective focal length of the lens sample to be inspected; when the lens to be inspected is a negative lens, F is the combined focal length of the lens sample to be inspected and the auxiliary lens.

[0030] On the other hand, the present invention provides an optical lens focus consistency detection device, including: a point divergence light source, a collimation system, a system to be inspected, a light spot analysis system, and a slide rail. The collimation system, the system to be inspected, and the light spot analysis system are sequentially installed on the slide rail. The fiber optic interface of the point divergence light source is connected to the collimation system. The point divergence light source, the optical axis of the collimation system, the optical axis of the system to be inspected, and the light incident port of the light spot analysis system are coaxially arranged.

[0031] Further, the system to be inspected includes a lens to be inspected, a clamping structure, and a mounting base. The light spot analysis system includes a light spot analysis module, a fine adjustment electric module, and a coarse adjustment sliding mounting base.

[0032] Further, the clamping structure includes a clamping structure for the lens to be inspected and a clamping structure for the auxiliary lens. When the lens to be inspected is a positive lens, an auxiliary lens is not required; when the lens to be inspected is a negative lens, an auxiliary lens is required, and the auxiliary lens is a positive lens.

[0033] The beneficial effects of the embodiments of the present invention are as follows: By setting a spot change range according to the spot size of the lens sample to be detected; moving the spot analyzer along the optical axis of the optical lens sample for the second debugging and detecting and analyzing the spot size of the lens sample to be detected, the spot analyzer detecting and recording multiple spot sizes within the spot change range and the corresponding position information; calculating the focal length D0 of the lens sample to be detected through the multiple position information; calculating the focal length Dn of the lens to be detected by using the same method; comparing the focal length Dn of the lens to be detected with the focal length D0 of the lens sample to be detected to analyze and verify the focal length consistency of the lens to be detected. The present invention does not directly detect the focal position of the lens to be detected to analyze the focal length consistency of the lens to be detected. Instead, according to the spot size of the lens to be detected, a spot change range is set, and the focal lengths of the lens to be detected and the lens sample to be detected are calculated by using multiple spot sizes within the spot change range of the spot sizes of the lens to be detected and the lens sample to be detected and the corresponding position information, effectively avoiding the problem that directly detecting the focal point of the lens to be detected near the focal point where the spot size in the depth of focus section is basically the same will seriously reduce the detection accuracy. Therefore, the present invention can greatly improve the detection accuracy and can meet the detection requirements of controlling the optical lens consistency difference within the order of magnitude of one-thousandth of the focal length.

[0034] In addition, the present invention first sets a reference spot size and a spot change range according to the focal point size of the lens sample to be detected, calculates the focal length D0 of the lens sample to be detected, and can detect the focal length Dn of the lens to be detected by using the same calculation method. It has high repeatability and a stable detection method, can realize repeated batch detection, reduce the detection cost, and improve the detection efficiency. Brief Description of the Drawings

[0035] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the specific embodiments or the prior art. Obviously, the following drawings are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0036] Figure 1 It is a schematic structural diagram of an optical lens focal point consistency detection device of the present invention.

[0037] 1 - point divergence light source; 2 - collimation system; 21 - collimating mirror module; 3 - system to be detected; 31 - lens clamping structure to be detected; 32 - auxiliary lens clamping structure; 4 - spot analysis system; 41 - fine-tuning electric module; 42 - spot analysis module; 43 - coarse-tuning sliding mounting base; 5 - slide rail. Detailed Embodiments

[0038] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some but not all of the embodiments of the present invention. Components of the embodiments of the present invention usually described and illustrated in the drawings here can be arranged and designed in various different configurations.

[0039] Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0040] It should be noted that like reference numerals and letters denote like items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0041] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings or the orientation or positional relationship in which the inventive product is customarily placed during use. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. In addition, the terms "first", "second", "third", etc. are only used for descriptive distinction and cannot be understood as indicating or implying relative importance.

[0042] In addition, terms such as "horizontal" and "vertical" do not mean that the components are required to be absolutely horizontal or hanging, but can be slightly inclined. For example, "horizontal" only means that its direction is more horizontal relative to "vertical", and does not mean that the structure must be completely horizontal, but can be slightly inclined.

[0043] In the description of the present invention, it should also be noted that unless otherwise clearly specified and defined, the terms "set", "installed", "connected", "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0044] In this embodiment, an optical lens focus consistency detection method provided by the present invention includes the steps:

[0045] S1: Set the reference spot size d and the spot change range according to the focal spot size R of the lens sample to be inspected.

[0046] The lens sample to be inspected is produced in the same batch and by the same process as the lens to be inspected, and is a standard sample that has passed the focus consistency verification. First, set the reference spot size d and the spot change range according to the focal spot size R of the lens sample to be inspected. The value range of the spot change range is [d×(1−k%), d×(1 + k%)], where the value range of k is 0.1 - 2, and d is the reference spot size of the lens sample to be inspected. R is also the focal spot size of the lens to be inspected. The reference spot size d of the lens sample to be inspected and the focal spot size R of the lens sample to be inspected satisfy d≥W×R, where the value range of W is 1.2 - 10. The spot change range can be adjusted according to the characteristics of the lens to be inspected (such as focal length, spot size, etc.) to meet the lens detection requirements of different batches and different suppliers.

[0047] The optical lens consistency detection method includes a light source, a system to be inspected, and a collimation module. The light emitted by the light source forms a parallel or nearly parallel light beam through the collimation module. The light beam enters the optical lens of the system to be inspected to form a focused light beam, and the spot of the focused light beam enters the spot analyzer for spot analysis. Among them, the beam waist diameter of the light source is C, the focal length of the lens sample to be inspected is f, the focal length of the collimation module is f0, and the focal spot size R of the lens sample to be inspected satisfies

[0048] S2: Place the lens sample to be inspected in the system to be inspected, and move the spot analyzer for debugging.

[0049] Among them, step S2 specifically includes: S21: If the spot analyzer detects that the spot size of the lens sample to be inspected exceeds the set magnitude, adjust the position of the spot analyzer to adjust the spot size below the set magnitude, and complete the first debugging of the spot analyzer.

[0050] The value range of the set magnitude is 100 - 500um, and the specific value is selected according to the optical characteristics of the lens to be inspected.

[0051] S22: Move the spot analyzer to detect all spot sizes near the focal spot of the lens sample to be inspected. The spot analyzer is fixedly set near the focal spot to complete the second debugging of the spot analyzer.

[0052] Performing the first debugging, that is, the initial adjustment, can quickly adjust the spot size to be close to the target range, thereby reducing the adjustment range and time of subsequent debugging and improving the detection efficiency.

[0053] The second debugging is to find the position of the focal spot size of the lens sample to be inspected. Move the spot analyzer to traverse all spot sizes near the focal spot size R of the lens sample to be inspected. Fixing the spot analyzer near the focal spot can ensure more accurate acquisition of spot size and position information during subsequent detection.

[0054] S3: Move the spot analyzer along the first direction of the optical axis of the lens sample to be inspected for detection, collect and record the first spot size R0 located in the spot change interval and the corresponding first position information N0; move the spot analyzer along the second direction of the optical axis of the lens sample to be inspected for detection, collect and record the second spot size S0 located in the spot change interval and the corresponding second position information M0.

[0055] The first direction refers to the direction of moving the spot analyzer closer to the system to be inspected, and the second direction refers to the direction of moving the spot analyzer away from the system to be inspected, where the second direction is the opposite direction of the first direction.

[0056] Furthermore, step S3 includes S31: Move the spot analyzer along the first direction of the optical axis of the lens sample to be inspected for detection. When the spot analyzer detects that the spot size is in the spot change interval, pause for S seconds. Calculate the average spot size based on the uploaded spot size and record it as the first spot size R0, and record the uploaded position information as the first position information N0.

[0057] S32: Move the spot analyzer along the second direction of the optical axis of the lens sample to be inspected for detection. When the spot analyzer detects that the spot size is in the spot change interval, pause for S seconds. Calculate the average spot size based on the uploaded spot size and record it as the second spot size S0, and record the uploaded position information as the second position information M0.

[0058] Pausing for S seconds is because the spot analyzer has detection deviations. For example, the movement of the electric module is affected by the power supply and environmental changes, which will all bring detection deviations. Pause for S seconds and record the spot size recorded by the spot analyzer of the tentative device. Calculate the average spot size based on the recorded spot size and record it as the first spot size R0, where the value range of S is 0.1s - 2s. The above method can eliminate the detection deviation of the spot analyzer and further improve the detection accuracy.

[0059] In step S31, if the first spot size R0 is not in the spot change interval, use a fixed step size to gradually compensate and adjust the position of the spot analyzer.

[0060] The specific method includes S311: If the first spot size R0 < d×(1 - k%), along the first direction of the optical axis of the lens sample to be inspected, use a fixed step size to gradually compensate and adjust the position of the spot analyzer until R0 is in the spot change interval.

[0061] S312: If the size of the first light spot R0 > d×(1 - k%), along the opposite direction of the first direction of the optical axis of the lens sample to be detected, adjust the position of the light spot analyzer by progressive compensation with a fixed step length until R0 is within the light spot change interval;

[0062] In step S32, if the size of the second light spot S0 is not within the light spot change interval, adjust the position of the light spot analyzer by progressive compensation with a fixed step length.

[0063] The specific method includes S321: If the size of the second light spot S0 < d×(1 - k%), along the second direction of the optical axis of the lens sample to be detected, adjust the position of the light spot analyzer by progressive compensation with a fixed step length until S0 is within the light spot change interval;

[0064] S322: If the size of the second light spot S0 > d×(1 - k%), along the opposite direction of the second direction of the optical axis of the lens sample to be detected, adjust the position of the light spot analyzer by progressive compensation with a fixed step length until S0 is within the light spot change interval.

[0065] During the process of adjusting by fixed compensation progressive compensation, the setting range of the fixed step length is 0.1 - 10um, and the specific adjustment value is selected according to the optical properties of the optical lens. This standardized adjustment method reduces the interference of human factors, improves the stability and repeatability of the detection process, and improves the detection accuracy of the consistency of optical lenses.

[0066] S4: Calculate the focal length D0 of the lens sample to be detected based on the above multiple position information.

[0067] Step S4 specifically includes calculating the focal length D0 of the lens sample to be detected according to the first average focal length N0 and the second average focal length M0, where the focal length D0 of the lens sample to be detected satisfies:

[0068]

[0069] By moving the light spot analyzer along the first direction of the optical axis of the lens sample to be detected for detection, calculate the size of the first light spot R0 and the corresponding first position information N0, move the light spot analyzer along the second direction of the optical axis of the lens sample to be detected for detection, calculate the size of the second light spot S0 and the corresponding second position information M0, and finally calculate the focal length through D0 = (N0 + M0) / 2. The second direction is the opposite direction of the first direction. The above method utilizes the symmetry relationship of the light spot size of the optical lens on both sides of the focus, and adopts the method of taking the average of the detections on both sides of the focus, reducing the random error of single measurement and further improving the detection accuracy.

[0070] S5: Place the lens to be inspected in the inspection system, and fix the spot analyzer at the focal length D0 position of the lens sample to be inspected; repeat steps S3 - S4 to detect and calculate the focal length Dn of the lens to be inspected.

[0071] Place the optical lenses to be inspected of the same specification in the inspection system in sequence, repeat steps S3 - S4 to complete the focus consistency inspection of the optical lenses to be inspected of the same batch and specification with the sample, and determine whether they are qualified.

[0072] S6: Compare the focal length D0 of the lens sample to be inspected with the focal length Dn of the lens to be inspected, and analyze and verify the focal length consistency of the lens to be inspected.

[0073] Furthermore, in step S6, if Dn satisfies: |D0 - Dn| ≤ F × t‰, it indicates that the focus consistency of the lens to be inspected is qualified; F is the focal length of the lens sample to be inspected.

[0074] If the lens to be inspected is a positive lens, F is the effective focal length of the lens sample to be inspected. If the lens to be inspected is a negative lens, F is the combined focal length of the lens sample to be inspected and the auxiliary lens. The calculation method of the combined focal length F is: where if the focal length of the lens sample to be inspected is f1 and the focal length of the auxiliary lens is f2, the combined focal length d is the distance between the lens sample to be inspected and the auxiliary lens. The focal length D0 of the lens sample to be inspected and the focal length Dn of the lens to be inspected are detected by using the same detection method, and the focal length of the lens sample to be inspected is compared and analyzed with the focal length of the lens to be inspected to determine the consistency of the lens to be inspected. All the difference comparisons are for the lens sample to be inspected and the lens to be inspected with the same theoretical parameters, that is, lenses of the same specification. Further improve the accuracy and stability of the detection structure.

[0075] Set the reference spot size and the spot change interval, and take the average of the position information corresponding to the spot size within the spot change interval to calculate the focal length of the optical lens, rather than directly detecting the focus of the optical lens to calculate the focal length of the optical lens, which can effectively avoid the problem of the focal depth section near the focus. Because the spot size in the focal depth section is basically the same, it will seriously reduce the detection accuracy. Therefore, compared with the vision detection method that directly detects the focal length and cannot avoid the depth of field problem, this technology greatly improves the detection accuracy.

[0076] In another embodiment of the present invention, an optical lens consistency detection device is provided, as Figure 1 shown, including: a point divergence light source 1, a collimation system 2, an inspection system 3, a spot analysis system 4, and a slide rail 5. The collimation system 2, the inspection system 3, and the spot analysis system 4 are sequentially installed on the slide rail 5, and the fiber optic interface of the point divergence light source 1 is connected to the collimation system 2.

[0077] This system modular device improves the compatibility and usability of the equipment, and is also convenient for maintenance and upgrade.

[0078] Among them, the point divergent light source 1 includes a fiber-optic output light source and a point light source with a fiber-optic interface property for free output. The spot ellipticity is above 85%. It is preferably a relatively smooth energy distribution such as Gaussian or quasi-Gaussian, flat-top spot, etc. The output light power is in the range of μW - mW, and it is any one of the monochromatic lights in the range of 400 nm - 1100 nm. The half-wave width is less than 100 nm and is preferably small, typically 5 nm or 10 nm.

[0079] The collimation system 2 includes a female part matching the fiber-optic interface, a collimating mirror module 21 with coaxial alignment, and a mounting base. The female part end is the light input port, and the light output end of the collimating mirror module 21 is the light output port. The female part, the collimating mirror, and the mounting base are structurally connected to form a fixed module.

[0080] The system to be inspected 3 includes a lens to be inspected, a clamping structure, and a mounting base. The spot analysis system includes a spot analysis module 42, a fine-tuning electric module 41, and a coarse-tuning sliding mounting base 43.

[0081] The clamping structure includes a clamping structure 31 for the lens to be inspected and a clamping structure 32 for the auxiliary lens. If the lens to be inspected is a positive lens, there is no need to use an auxiliary lens; if the lens to be inspected is a negative lens, an auxiliary lens needs to be used, and the auxiliary lens is a positive lens. The clamping structure supports the installation of the lens to be inspected and the auxiliary lens, and can be flexibly adjusted according to the lens type, further improving the versatility and flexibility of the detection device.

[0082] The spot analysis system 4 includes a slit scanning analyzer, a camera-type spot analyzer, and other analysis devices, and can detect at least the spot size and position of the aforementioned point divergent light source; the movement stroke of the fine-tuning electric module ranges from 1 mm to 20 mm, and the accuracy is in the order of 0.001 mm to 0.01 mm; the mounting part of the spot analysis module is connected to the electric telescopic part of the fine-tuning electric module, and the spot analysis module can expand and contract with the electric telescopic part of the fine-tuning electric module; the fine-tuning electric module and the spot analysis module are integrally assembled on the coarse-tuning sliding mounting base, and the coarse-tuning sliding mounting base is equipped with a locking structure; the control drivers of the spot analysis module and the fine-tuning electric module are electrically connected to the computer and the host.

[0083] The collimation system 2 and the system to be inspected 3 are fixed, and the spot analysis system 4 can move along the slide rail 5; and the point divergent light source 1, the optical axis of the collimating mirror of the collimation system 2, the optical axis of the optical lens to be inspected of the system to be inspected 3 or the optical axis of the optical lens and the auxiliary mirror, and the light input port of the spot analysis system 4 are coaxially arranged.

[0084] In terms of the beam transmission mode, the point divergent light source 1 emits divergent light, which is collimated by the collimating mirror of the collimation system 2 to form a parallel or nearly parallel beam, and then is focused by the optical lens to be inspected of the system to be inspected 3 or the optical lens and the auxiliary mirror to form a focused beam, and the spot of the focused beam hits the spot analysis system 4 for spot size analysis.

[0085] The above optical lens consistency detection device can quickly and accurately detect the optical performance of lenses, and is applicable to the production, research and development, and quality control of optical lenses. By measuring the spot size and position within a certain range to evaluate the focusing performance of the optical lens, it effectively avoids the problem of depth of focus near the focal point and improves the detection accuracy.

[0086] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for detecting the focus consistency of an optical lens, characterized in that: Includes steps: S1: According to the focal spot size R of the lens sample to be tested, set the reference spot size d and the spot change range; S2: Place the lens sample to be tested in the system to be tested, and move the spot analyzer for debugging; S3: moving the spot analyzer for detection along the first direction of the optical axis of the lens sample to be tested, collecting and recording the first spot size R0 and the corresponding first position information N0 in the spot change interval; moving the spot analyzer for detection along the second direction of the optical axis of the lens sample to be tested, collecting and recording the second spot size S0 and the corresponding second position information M0 in the spot change interval; S4: Calculating the focal length D0 of the lens sample to be inspected according to the first position information N0 and the second position information M0; S5: placing the lens to be tested in the system to be tested, fixing the spot analyzer to the focal length D0 position of the lens sample to be tested; repeating steps S3-S4 to detect and calculate the focal length Dn of the lens to be tested; S6: Compare the focal length D0 of the lens sample to be tested with the focal length Dn of the lens to be tested, and analyze and verify the consistency of the focal length of the lens to be tested.

2. The method for detecting focus consistency of an optical lens according to claim 1, characterized in that: In step S1, the value range of the light spot variation interval is [d×(1-k%), d×(1+k%)], the value range of k is 0.1-2, where d is the reference light spot size of the lens sample to be tested; The reference spot size d of the lens sample to be tested and the focal spot size R of the lens sample to be tested satisfy d≥W×R, and the value range of W is 1.2-10.

3. The method for detecting focus consistency of an optical lens according to claim 1, characterized in that: Step S2 includes: S21: if the spot analyzer detects that the spot size of the lens sample to be tested exceeds a set level, adjusting the position of the spot analyzer to adjust the spot size to below the set level, completing the first debugging of the spot analyzer; S22: moving the spot analyzer to traverse the spot size near the focal spot of the lens sample to be inspected, the spot analyzer is fixedly set near the focal spot, and the second debugging of the spot analyzer is completed.

4. The method for detecting focus consistency of an optical lens according to claim 1, characterized in that: Step S3 The method comprises: S31: moving the spot analyzer along the first direction of the optical axis of the lens sample to be tested for detection, pausing for S seconds when the spot analyzer detects that the spot size is in the spot change interval, calculating the average spot size according to the uploaded spot size and recording it as the first spot size R0, and recording the uploaded position information as the first position information N0; S32: Move the spot analyzer along the second direction of the optical axis of the lens sample to be tested for detection. When the spot analyzer detects that the spot size is in the spot change interval, it pauses for S seconds. The average spot size is calculated based on the uploaded spot size and recorded as the second spot size S0. The uploaded position information is recorded as the first position information M0.

5. The method for detecting focus consistency of an optical lens according to claim 1, characterized in that: Step S4 specifically includes: calculating the focal length D0 of the lens sample to be tested, wherein the first position information N0, the second position information M0, and the focal length D0 of the lens sample to be tested satisfy:

6. The method for detecting focus consistency of an optical lens according to claim 1, characterized in that: In step S31, if the first spot size R0 is not within the spot variation interval, the position of the spot analyzer is adjusted by using fixed step size progressive compensation; In step S32, if the second spot size S0 is not within the spot variation range, the position of the spot analyzer is adjusted by using fixed step size progressive compensation.

7. The method for detecting focus consistency of an optical lens according to claim 6, characterized in that: In step S31, if the first spot size R0 is not within the spot variation interval, the specific method of adjusting the position of the spot analyzer by using fixed step-size progressive compensation is: S311: If the first spot size R0 is less than d×(1-k%), the position of the spot analyzer is adjusted along the first direction of the optical axis of the lens sample to be inspected by using fixed step-size progressive compensation until R0 is located in the spot variation range; S312: If the first spot size R0>d×(1-k%), adjust the position of the spot analyzer along the opposite direction of the first direction of the optical axis of the lens sample to be inspected by using fixed step size progressive compensation until R0 is located in the spot change range; In step S32, if the second spot size S0 is not within the spot variation range, the specific method of adjusting the position of the spot analyzer by using fixed step-size progressive compensation is: S321: If the second spot size S0 is less than d×(1-k%), the position of the spot analyzer is adjusted along the second direction of the optical axis of the lens sample to be inspected by using fixed step-size progressive compensation until S0 is located in the spot variation range; S322: If the second spot size S0>d×(1-k%), adjust the position of the spot analyzer along the opposite direction of the second direction of the optical axis of the lens sample to be inspected by using fixed step progressive compensation until S0 is located in the spot change range.

8. The method for detecting focus consistency of an optical lens according to claim 1, characterized in that: In step S6, if Dn satisfies: |D0-Dn|≤F×t‰, it means that the focus consistency of the lens to be tested is qualified; F is the focal length of the lens sample to be tested, and the value range of t is 0.1-10.

9. The method for detecting focus consistency of an optical lens according to claim 8, characterized in that: The lens to be tested is a positive lens, and F is the effective focal length of the lens sample to be tested; the lens to be tested is a negative lens, and F is the combined focal length of the lens sample to be tested and the auxiliary lens.

10. An optical lens focus consistency detection device, which can be used in an optical lens focus consistency detection method according to any one of claims 1 to 9, characterized in that: include: A point divergent light source, a collimation system, a system to be inspected, a light spot analysis system, and a slide rail. The collimation system, the system to be inspected, and the light spot analysis system are sequentially mounted on the slide rail. The optical fiber interface of the point divergent light source is connected to the collimation system. The point divergent light source, the optical axis of the collimation system, the optical axis of the system to be inspected, and the light inlet of the light spot analysis system are coaxially arranged.

11. The optical lens focus consistency detection device according to claim 10, characterized in that: The system to be inspected includes a lens to be inspected, a clamping structure, and a mounting base, and the light spot analysis system includes a light spot analysis module, a fine adjustment electric module, and a coarse adjustment sliding mounting base.

12. The optical lens focus consistency detection device according to claim 11, characterized in that: The clamping structure includes a clamping structure for a lens to be inspected and an auxiliary lens clamping structure. If the lens to be inspected is a positive lens, no auxiliary lens is needed; if the lens to be inspected is a negative lens, an auxiliary lens is needed, and the auxiliary lens is a positive lens.

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