Dual-gaussian dual-pathway structure
By employing a dual-Gauss dual-optical-path structure and utilizing a combination of thick and thin lenses, aberrations, spherical aberrations, chromatic aberrations, and field curvature are effectively corrected, achieving high-quality imaging, especially under large field-of-view conditions.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- VEGETABLE RES INST GUANGDONG ACAD OF AGRI SERVICES
- Filing Date
- 2023-06-29
- Publication Date
- 2026-07-10
AI Technical Summary
Existing dual-path structures are inadequate in eliminating aberrations, spherical aberrations, chromatic aberrations, field curvature, and astigmatism correction, especially in cases with large field of view, resulting in significant imaging distortion.
It adopts a dual-Gauss dual-optical-path structure, corrects field curvature by changing the structure of the thick lens, corrects spherical aberration by using the curvature of the thin lens, corrects astigmatism by changing the distance between the thick lenses, and corrects chromatic aberration by using a cemented lens, ensuring that the distortion of the transmitted and reflected light paths in the entire field of view is less than 2%.
The system achieves a root mean square dot plot radius of less than 8 micrometers across the entire field of view for both transmitted and reflected light paths, with imaging distortion below 2%, significantly improving the imaging quality of the light path.
Smart Images
Figure CN116661141B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of optics, specifically to a double Gaussian double optical path structure. Background Technology
[0002] CN101852725B discloses a full-spectrum transmission non-destructive testing device and method for plant biochemical parameters, addressing technical issues such as low model applicability, poor anti-interference ability, low detection accuracy, and limited detection parameters in current spectral non-destructive testing methods. It employs a full-spectrum transmission measurement principle to achieve high-precision simultaneous measurement of multiple parameters; utilizes a time-dual optical path reference measurement principle to ensure the accuracy and precision of the transmission spectral signal; and integrates a transmission fixture and a programmable adjustable voltage-controlled drive light source circuit, enabling this measurement principle to be implemented in plant leaf transmission spectral measurement, forming a miniaturized and portable non-destructive testing device for plant biochemical parameters. The predictive model in the device uses an improved extended multivariate scattering correction method to correct for baseline differences caused by leaf scattering and variations in leaf thickness, improving the sensitivity of spectral data to chemical concentrations and enhancing the model's anti-interference ability.
[0003] CN109001149A discloses a dual-optical-path fruit non-destructive testing system and method based on near-infrared spectroscopy, belonging to the field of near-infrared spectroscopy non-destructive testing technology. It includes a power supply module, an LED light source, an optical path module, and a circuit module connected in sequence. The power supply module supplies power to the LED light source, which generates near-infrared spectra that enter the optical path module. The optical path module divides the near-infrared spectrum into two paths: one path is used as a reference for data acquisition, and the other path is used to irradiate and acquire data from the test object. The acquired data from both paths is then transmitted to the circuit module, which performs correction processing on the acquired data before storing it. This method solves the problems of existing near-infrared spectroscopy fruit non-destructive testing equipment, such as the influence of light source jitter, difficulty in accurately reflecting the absorption spectrum of the test object, inability to quantify the test results, limited application scenarios, and cumbersome usage methods.
[0004] The instruction manual states that the optical path module includes a first collimator, a beam splitter connected to the first collimator, a second collimator, a reference chamber, and a first detector connected sequentially to the beam splitter, and a third collimator, a collection chamber, and a second detector connected sequentially to the beam splitter. The first collimator collimates the near-infrared spectrum generated by the LED light source and then splits it into two equal-power optical paths by the beam splitter. One path is collimated by the second collimator and enters the reference chamber, where a white board is installed. The reflected light from the white board is then collected by the first detector in real time. The other path is collimated by the third collimator and enters the collection chamber. After illuminating the object, the second detector collects the absorbed light data of the object.
[0005] This optical path structure is too simple, and its ability to eliminate aberrations in both optical paths, as well as spherical aberration, chromatic aberration, field curvature, and astigmatism, needs further improvement.
[0006] CN114485429A discloses a real-time measurement device and method for the growth height of gas crystallization thin films, including an interferometric measurement system and a control and processing module. The interferometric measurement system includes a fiber laser, a single-mode polarization-maintaining fiber, a cemented doublet lens, a polarizer, a polarizing beam splitter, a quarter-wave plate, a plane mirror, a piezoelectric ceramic, an analyzer, a microscope objective, an imaging mirror, and a camera. The control and processing module includes a phase-shifting control module, an image acquisition module, and an interferogram data analysis and processing module. The phase-shifting control module is connected to the piezoelectric ceramic and achieves a small displacement with a fixed step size by controlling the applied voltage, thereby introducing a phase shift. The image acquisition module is connected to the camera and acquires an interferogram of the film growth after each phase shift. After acquiring a set of phase-shifted interferograms, the data is transmitted to the interferogram data analysis and processing module for analysis. Using this invention, the growth height of rare gas crystallization thin films can be calculated effectively and with high precision in real time.
[0007] Its optical path structure is as follows:
[0008] The laser generated by the fiber laser is emitted through a single-mode polarization-maintaining fiber. The divergent Gaussian beam is converted into a converging light wave after passing through a cemented doublet lens. It is then transmitted to a polarizing beam splitter via a polarizer and split into two light paths: a reference path and a detection path.
[0009] The conventional dual-beam path fruit non-destructive testing structure uses two plano-convex lenses combined to converge and form a light spot in the main beam path, and a reflector and a single plano-convex lens to converge and form the beam path in the split beam path. This design has aberrations.
[0010] The technical problem solved in this case is how to minimize the aberrations of the two optical paths. However, further improvements are needed in the correction of spherical aberration, chromatic aberration, field curvature, and astigmatism. Summary of the Invention
[0011] The purpose of this invention is to provide a dual-Gaussian dual-optical-path structure that can minimize aberrations in both optical paths. In the dual-Gaussian objective lens, field curvature can be corrected by structural changes in the thick lens, spherical aberration can be corrected by the curvature of the thin lens, astigmatism can be corrected by changing the distance between the two thick lenses, and chromatic aberration can be corrected by the cemented lens. The radius of the root mean square dot plot of the transmitted optical path across the entire field of view and wavelength is less than 8 micrometers, and the imaging distortion is less than 2%. The radius of the root mean square dot plot of the reflected optical path across the entire field of view and wavelength is less than 8 micrometers, and the imaging distortion is less than 2%.
[0012] To achieve the above objectives, the present invention provides the following technical solution: a dual-Gaussian dual-optical-path structure, comprising an incident optical path, a transmitted optical path, and a reflected optical path, wherein the transmitted optical path comprises a first single lens, a first cemented doublet lens, a second cemented doublet lens, and a second single lens arranged sequentially; and the reflected optical path comprises a reflector, a third single lens, a third cemented doublet lens, a fourth cemented doublet lens, and a fourth single lens arranged sequentially.
[0013] The first cemented doublet lens is composed of a first lens and a second lens; the second cemented doublet lens is composed of a third lens and a fourth lens; the third cemented doublet lens is composed of a fifth lens and a sixth lens; and the fourth cemented doublet lens is composed of a seventh lens and an eighth lens.
[0014] The first lens has a radius of curvature of 35.179 mm and a thickness of 14 mm.
[0015] The second lens has a rear mirror surface with a radius of curvature of 19.293 mm and a thickness of 3.777 mm.
[0016] The radius of curvature of the front surface of the third lens is -14.397 mm, and the thickness is 3.777 mm.
[0017] The fourth lens has a rear mirror surface with a radius of curvature of -21.643 mm and a thickness of 10.834 mm.
[0018] The radius of curvature of the front surface of the fifth lens is 32.124 mm, and the thickness is 14 mm.
[0019] The radius of curvature of the rear mirror surface of the sixth lens is 19.293 mm, and the thickness is 3.777 mm.
[0020] The radius of curvature of the front surface of the seventh lens is -14.397 mm, and the thickness is 3.777 mm.
[0021] The radius of curvature of the rear mirror surface of the eighth lens is -21.643 mm, and the thickness is 10.834 mm.
[0022] In the above-mentioned dual-Gauss dual-optical-path structure, the front mirror of the first single lens has a curvature radius of 91.741 mm and the rear mirror has a curvature radius of -218.917 mm and a thickness of 8.747 mm.
[0023] In the above-mentioned dual-Gauss dual-optical-path structure, the radius of curvature of the front mirror of the second single lens is 46.316 mm and the radius of curvature of the rear mirror is -170.607 mm, and the thickness is 6.858 mm.
[0024] In the above-mentioned dual-Gauss dual-optical-path structure, the radius of curvature of the front mirror of the third single lens is 58.765 mm, the radius of curvature of the rear mirror is 225.78 mm, and the thickness is 8.747 mm.
[0025] In the above-mentioned dual-Gauss dual-optical-path structure, the radius of curvature of the front mirror of the fourth single lens is 42.090 mm and the radius of curvature of the rear mirror is -873.269 mm, and the thickness is 6.858 mm.
[0026] In the above-mentioned dual-Gaussian dual-optical-path structure, the incident optical path includes a fifth single lens, a fifth cemented doublet lens, and a beam splitter prism;
[0027] The fifth cemented doublet lens is composed of the ninth lens and the tenth lens;
[0028] The radius of curvature of the front mirror surface of the ninth lens is 126.401 mm, and the thickness is 7 mm.
[0029] The tenth lens has a front surface curvature radius of -16.366 mm and a rear surface curvature radius of -37.039 mm, and a thickness of 6.000 mm.
[0030] In the aforementioned dual-Gauss dual-optical-path structure, the radius of curvature of the rear mirror surface of the fifth single lens is -50.133 mm, and the thickness is 15.000 mm.
[0031] Compared with the prior art, the beneficial effects of the present invention are:
[0032] This invention adds a positive and a negative lens after a plano-convex lens for image ablation, ensuring that the imaging quality and illumination of the two optical paths are as close as possible to eliminate aberrations. It employs a double Gaussian structure (two single lenses plus two cemented lenses). Because the double Gaussian objective is a symmetrical system, transverse aberration is easily corrected. When designing this type of system, only the correction of spherical aberration, chromatic aberration, field curvature, and astigmatism needs to be considered. In the double Gaussian objective, field curvature can be corrected by structural changes in the thicker lens, spherical aberration can be corrected by the curvature of the thinner lens, astigmatism can be corrected by changing the distance between the two thicker lenses, and chromatic aberration can be corrected by the cemented lenses. Attached Figure Description
[0033] Figure 1 This is a schematic diagram of the optical path structure of Embodiment 1 of the present invention. Detailed Implementation
[0034] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0035] Example 1
[0036] refer to Figure 1 A dual-Gaussian dual-optical-path structure includes an incident optical path, a transmitted optical path, and a reflected optical path. The transmitted optical path includes a first single lens, a first cemented doublet lens, a second cemented doublet lens, and a second single lens arranged in sequence. The reflected optical path includes a reflector, a third single lens, a third cemented doublet lens, a fourth cemented doublet lens, and a fourth single lens arranged in sequence.
[0037] The first cemented doublet lens consists of a first lens and a second lens; the second cemented doublet lens consists of a third lens and a fourth lens; the third cemented doublet lens consists of a fifth lens and a sixth lens; the fourth cemented doublet lens consists of a seventh lens and an eighth lens; the incident light path includes a fifth single lens, a fifth cemented doublet lens, and a beam splitter; the fifth cemented doublet lens consists of a ninth lens and a tenth lens; relevant parameters can be found in Table 1 below:
[0038] Table 1 Lens Specifications
[0039]
[0040]
[0041] The relevant specifications in Table 1 are explained below:
[0042] Fifth single lens (Figure No. 1): Infinity and -50.133 represent that the front mirror surface is flat and the radius of curvature of the rear mirror surface is -50.133, respectively; the negative radius of the rear mirror surface means that its curvature direction is to the right.
[0043] Thickness (mm): 4 and 15 respectively. 4 represents the thickness of the curved surface where the front and rear mirrors meet, and 15 represents the distance from the rear mirror to the ninth lens.
[0044] Ninth lens (Figure 2): The radius of curvature of the front mirror is 126.401, and the thickness is 7mm; the radius of curvature of the rear mirror is referenced to the radius of curvature of the front mirror of the tenth lens because it is attached to the front mirror of the tenth lens.
[0045] Tenth Lens (Figure No. 2): The ninth lens is located between the tenth lens and the fifth single lens, and its radius of curvature is -16.366 (radius of curvature of the front mirror) and -37.039 (radius of curvature of the rear mirror); 6 represents the distance from the front mirror to the rear mirror, and 20 represents the distance from the rear mirror to the beam splitter.
[0046] Beam splitter (Figure No. 3): Its radius of curvature is Infinity, Infinity, which means that the front and rear mirrors are both flat, the thickness is 32, and the distance from the rear mirror to the first single lens is 20.
[0047] The first single lens (Figure No. 4): its radius of curvature is 91.741 (radius of curvature of the front mirror) and -218.917 (radius of curvature of the rear mirror), 8.747 represents the lens thickness, and 0.5 represents the distance from the rear mirror to the first lens.
[0048] First lens (Figure No. 5): Its radius of curvature is 35.179 (radius of curvature of the front mirror surface), the rear mirror surface is flat, and 14 is the thickness of the first lens;
[0049] The second lens (Figure 5): The first lens is located between the second lens and the first single lens, and its radius of curvature is Infinity, 19.293, Infinity, which means that both the front and rear mirror surfaces are flat. The radius of curvature of the concave part on the rear mirror surface is 19.293; 3.777 represents the thickness of the second lens. There is a virtual surface between the second lens and the third lens. The distance from the rear mirror surface of the second lens to the virtual surface is 14.253, and the distance from the virtual surface to the front mirror surface of the third lens is 12.428; that is, the distance from the rear mirror surface (planar position) of the second lens to the front mirror surface of the third lens is 26.735.
[0050] The third lens (Figure 6): its radius of curvature is -14.397 (radius of curvature of the front mirror), the rear mirror is flat, and the thickness of the third lens is 3.777.
[0051] The fourth lens (Figure 6): its radius of curvature is Infinity and -21.643. The third lens is located between the fourth lens and the second lens. Infinity means that the front mirror surface of the fourth lens is flat, and -21.643 is the radius of curvature of the rear mirror surface of the fourth lens. 10.834 represents the thickness of the fourth lens, and 0.5 represents the distance from the rear mirror surface of the fourth lens to the front mirror surface of the second single lens.
[0052] The second single lens (Figure No. 7) has a radius of curvature of 46.316 (radius of curvature of the front mirror) and -170.607 (radius of curvature of the rear mirror); 6.858 represents the thickness of the second single lens, and 48.82 represents the distance from its rear mirror to the image receiving unit (such as an image sensor).
[0053] The third single lens (Figure No. 9): 58.765 (radius of curvature of the front mirror), 225.78 (radius of curvature of the rear mirror), 8.747 is the lens thickness, and 0.5 is the distance from the rear mirror of the third single lens to the front mirror of the fifth lens.
[0054] The fifth lens (Figure No. 10): its radius of curvature is 32.124 (radius of curvature of the front mirror), the rear mirror is flat, and 14 is the thickness of the fifth lens;
[0055] The sixth lens (Figure 10): The fifth lens is located between the sixth lens and the third single lens. Its radius of curvature is Infinity, 19.293, Infinity, which means that both the front and rear mirror surfaces are flat. The radius of curvature of the concave part on the rear mirror surface is 19.293. 3.777 represents the thickness of the second lens. There is a virtual surface between the sixth and seventh lenses. The distance from the rear mirror surface of the sixth lens to the virtual surface is 14.253, and the distance from the virtual surface to the front mirror surface of the seventh lens is 12.428. That is, the distance from the rear mirror surface (flat position) of the sixth lens to the front mirror surface of the seventh lens is 26.735.
[0056] The seventh lens (Figure No. 11): its radius of curvature is -14.397 (radius of curvature of the front mirror surface), the rear mirror surface is flat, and the thickness of the seventh lens is 3.777;
[0057] The eighth lens (Figure 11): its radius of curvature is Infinity and -21.643. The seventh lens is located between the eighth and sixth lenses. Infinity means that the front mirror surface of the eighth lens is flat, and -21.643 is the radius of curvature of the rear mirror surface of the eighth lens. 10.834 represents the thickness of the eighth lens, and 0.5 represents the distance from the rear mirror surface of the eighth lens to the front mirror surface of the fourth single lens.
[0058] The fourth single lens (Figure 12) has a radius of curvature of 42.09 (radius of curvature of the front lens) and -873.269 (radius of curvature of the rear lens); 6.858 represents the thickness of the fourth single lens, and 48.82 represents the distance from its rear lens to the image receiving unit (such as an image sensor).
[0059] The relevant principles in this case are as follows:
[0060] This design employs a double Gaussian structure (two monolithic lenses plus two cemented doublets). Because a double Gaussian objective is a symmetrical system, transverse aberration is easily corrected. When designing this type of system, only corrections for spherical aberration, chromatic aberration, field curvature, and astigmatism need to be considered. In a double Gaussian objective, field curvature can be corrected by structural changes in the thicker lenses, spherical aberration can be corrected by the curvature of the thinner lenses, astigmatism can be corrected by changing the distance between the two thicker lenses, and chromatic aberration can be corrected by the cemented doublets.
[0061] Compared to the dual-optical-path system described in CN114485429A, this case, although employing a dual-optical-path system and featuring a cemented lens plus a single lens, is not a double-Gaussian structure. On the one hand, this system is not a symmetrical structure, making it difficult to correct transverse aberrations. On the other hand, it does not have the advantage of easily correcting field curvature, spherical aberration, and astigmatism through structural transformation. Furthermore, its single cemented lens does not have the same chromatic aberration correction capability as a double cemented lens.
[0062] Compared to CN201811012191.8, that solution uses a typical Gaussian optical path. However, that solution is applied to a spectrometer optical path, where the object is actually a slit with a width of tens of micrometers. In contrast, the field of view of this solution is the entire object height of 4mm. The magnitude of the system's aberrations is related to the field of view; the larger the field of view, the greater the aberrations. Therefore, although the imaging distortion effect of this solution is not as good as that solution, the effect of that solution is based on its very small field of view. Furthermore, due to the small field of view of its optical path, this solution is not applicable.
[0063] Through the optimizations described in Table 1, this solution achieves a root mean square (RMS) dot plot radius of less than 8 micrometers and imaging distortion of less than 2% across the entire field of view and wavelength in the transmitted light path; similarly, the RMS dot plot radius of less than 8 micrometers and imaging distortion of less than 2% across the entire field of view and wavelength in the reflected light path. This solution, through dual-path design and data optimization of individual light paths, eliminates aberrations in both paths, providing a valuable basis for comparison between the two light paths.
Claims
1. A dual-Gaussian dual-optical-path structure, comprising an incident optical path, a transmitted optical path, and a reflected optical path, characterized in that, The transmitted light route consists of a first single lens, a first cemented doublet, a second cemented doublet, and a second single lens arranged in sequence; the reflected light route consists of a reflector, a third single lens, a third cemented doublet, a fourth cemented doublet, and a fourth single lens arranged in sequence. The first cemented doublet lens is composed of a first lens and a second lens; the second cemented doublet lens is composed of a third lens and a fourth lens; the third cemented doublet lens is composed of a fifth lens and a sixth lens; and the fourth cemented doublet lens is composed of a seventh lens and an eighth lens. The incident light path consists of a fifth single lens, a fifth cemented doublet lens, and a beam splitter. The fifth cemented doublet lens is composed of the ninth lens and the tenth lens; The parameters of each lens in the transmission optical path, reflection optical path, and incident optical path are shown in Table 1 below; Table 1 Lens Specifications 。