31 results about "Ultraviolet fluorescence" patented technology

This invention discloses a method for detecting polycyclic aromatic hydrocarbons (PAHs) based on ultraviolet fluorescence and absorption spectroscopy, comprising: Step 1, acquiring the ultraviolet absorption spectrum and the fluorescence emission spectrum of a water sample under ultraviolet light excitation; Step 2, analyzing the corresponding CDOM fluorescence spectrum using the ultraviolet absorption spectrum obtained in Step 1; Step 3, subtracting the CDOM fluorescence spectrum obtained in Step 2 from the fluorescence emission spectrum obtained in Step 1 to obtain a mixed fluorescence spectrum containing multiple PAHs; Step 4, performing multivariate fitting on the mixed fluorescence spectrum obtained in Step 3 to obtain the type and concentration of each PAH in the water sample. This invention also provides a PAH detection device. The method provided by this invention is simple to operate and can directly detect raw water samples, thereby obtaining more accurate PAH detection results.

This invention provides a hydrocarbon gas separation system, comprising a double-layered tube assembly and a negative pressure system. The double-layered tube assembly includes a medium delivery inner tube, a multi-layered membrane assembly, an annular interlayer gap, and a pressure-bearing protection section outer tube. The double-layered tube assembly is sealed at both ends. The multi-layered membrane assembly includes a retention layer, an isolation layer, and a selectively permeable membrane layer. The medium delivery inner tube is nested inside the pressure-bearing protection section outer tube and encloses the multi-layered membrane assembly. The negative pressure system is connected to the double-layered tube assembly. After the mixed gas is processed by the multi-layered membrane assembly in the medium delivery inner tube, sulfur dioxide is retained. The hydrocarbon gas enters the annular interlayer gap for extraction, and the retained sulfur dioxide is released back into the gas. Finally, the gas enters a sulfur dioxide detection instrument and is detected using ultraviolet fluorescence, making the data more consistent with the actual value and providing a scientific basis for relevant decision-making.

This application discloses a high-transmittance ultraviolet fluorescence detection lens, relating to the field of optical lenses. It addresses the problems of insufficient transmittance, severe fluorescence signal attenuation, and poor image quality in existing ultraviolet fluorescence detection lenses. The lens is constructed by sequentially arranging an object surface protection window, a first lens, a second lens, a third lens, an aperture stop, a fourth lens, a fifth lens, and an image plane along the optical axis from the object side to the image side. The object surface protection window is made of calcium fluoride, and at least a portion of the first to fifth lenses are made of calcium fluoride and at least a portion of fused silica. Each lens surface is coated with an ultraviolet antireflection film. By combining calcium fluoride and fused silica to optimize ultraviolet transmittance, and using a multi-layer ultraviolet antireflection film to reduce surface reflection loss, the lens achieves an overall transmittance of over 88% in the 250nm-380nm band. This effectively reduces fluorescence signal attenuation, significantly improves image brightness and contrast, and achieves good aberration correction. The compact structure makes it suitable for mass production applications.

The invention discloses a method for regulating and enhancing ultraviolet fluorescence of rare earth up-conversion nanocrystals through a local structure and a method for measuring the local structure, and belongs to the field of rare earth luminescent nanomaterials. According to the method, in the process of synthesizing the LiREF4: coated LiREF4 core-shell structure, the stoichiometric ratio of LiOH and NH4F in a core layer and / or the use amount of lithium trifluoroacetate in a shell layer are precisely regulated and controlled, and the localized crystal field environment around activated ions is changed, so that the selective regulation and control on the luminescence transition path of the activated ions are realized, and the emission intensity of multiphoton ultraviolet up-conversion luminescence is improved. According to the method, the high-order multi-photon up-conversion process of rare earth ions can be remarkably enhanced, meanwhile, low-order emission is inhibited, the luminescence selectivity of an up-conversion nano material is improved, emission light with the corresponding wavelength can be synthesized from the same matrix material according to the requirements of synthesizers, and the method can be suitable for various rare earth active ions and matrix materials and has a wide application prospect. The method has application potential in the fields of nano photonics and biomedicine.

The application discloses a SO2 detection device and concentration inversion method based on ultraviolet fluorescence spectrum and deep learning, and the SO2 detection device comprises a xenon lamp, a sample cell, a spectrum dispersion structure and an ultraviolet camera.

The invention relates to the technical field of oil leakage detection, and provides an oil-filled equipment intelligent detection method and system based on fluorescence reflection, and the method comprises the steps: obtaining a background image collected by each image collection unit when a fluorescence excitation unit is not started; acquiring a fluorescence image acquired by each image acquisition unit when the fluorescence excitation unit is started; determining a common difference image; determining a to-be-monitored area of the oil filling equipment according to the common differential image, controlling a pulse thermal excitation module to send a thermal excitation pulse to the to-be-monitored area, and controlling a set image acquisition unit to acquire fluorescence signal response characteristics of the to-be-monitored area; and the intelligent analysis module traces the leakage area according to the fluorescent signal response characteristics of the insulating oil and the leakage characteristic area. According to the invention, the technical problem of high false alarm rate in the existing insulating oil leakage detection technology based on the ultraviolet fluorescence characteristic of the insulating oil can be solved.

The invention discloses an ultraviolet-proof fluorescent fabric and a preparation method thereof, the ultraviolet-proof fluorescent fabric comprises the ultraviolet-proof fluorescent fabric, the main components of the ultraviolet-proof fluorescent fabric comprise a base cloth layer, a middle bonding layer and a surface coating layer, and the base cloth layer can be made of different materials according to actual requirements so as to adapt to wearing requirements in different seasons. According to the ultraviolet-proof fluorescent reflective fabric, the ultraviolet-proof function and the fluorescent reflective function are integrated through the surface layer composite coating, the titanium dioxide provides reliable ultraviolet shielding capacity, the efficient and lasting diffuse reflection fluorescent effect is achieved through combination of the aluminum powder and the directional arrangement agent, the visibility and safety of the fabric at night or in a low-light environment are remarkably improved, and the service life of the fabric is prolonged. The fabric can meet the requirements of multiple scenes such as outdoor protection, occupational safety and sports and leisure at the same time, practicability and warning performance are achieved, in addition, the material of the base cloth layer can be flexibly selected according to seasons and purposes, and the application field of the fabric is further widened.

The utility model relates to the technical field of cleanliness detection, in particular to a device for detecting cleanliness on line based on an ultraviolet fluorescence method. The device for online detection of the cleanliness based on the ultraviolet fluorescence method comprises a measurement module; the measurement module comprises a light path module and a calibration module; the calibration module comprises a stepping motor, a standard sample bracket and a position detection sensor; the stepping motor is connected with the standard sample bracket and drives the standard sample bracket to rotate, and the standard sample bracket comprises a plurality of cleanliness sample bracket units and channels arranged among the cleanliness sample bracket units; and the position detection sensor is arranged on the standard sample bracket. The light path module carries out detection by adopting an ultraviolet fluorescence method, has high sensitivity to common pollutants such as oil stains and organic impurities on the metal plate strip, can accurately detect trace pollutants, and improves the precision of cleanliness detection.

The utility model discloses a kind of efficient ultraviolet fluorescence collection imaging systems, including imaging lens sleeve, still including fluorescence signal detector, second ultraviolet lenticular lens, first ultraviolet lenticular lens and spherical mirror sequentially arranged, imaging lens sleeve two ends are light inlet end and light outlet end respectively, first ultraviolet lenticular lens is arranged at the light inlet end of imaging lens sleeve, second ultraviolet lenticular lens is arranged in imaging lens sleeve, the focal length of first ultraviolet lenticular lens between first ultraviolet lenticular lens and spherical mirror coincides with the curvature center of first ultraviolet lenticular lens.The utility model is combined by increasing spherical mirror and conventional imaging lens, increase the solid angle of fluorescence collection, thereby improve the collection efficiency of fluorescence;The length of imaging system is adjustable, can satisfy the use scene when the distance from fluorescence signal detector to imaging system is fixed.

The application provides a fluorescence testing device and testing method for continuous detection of organic pollutants in soil. A hydraulic transmission device is used to push multiple connectable straight push probes into the soil. A built-in ultraviolet light source of a specific wavelength is used to induce the organic pollutants in the soil to generate fluorescence. A miniature camera is used to collect and record the fluorescence image. An automatic cleaning module is used to continuously clean the sapphire glass window in contact with the soil on the straight push probe, preventing test errors caused by organic pollutants staining the glass during continuous detection. Image analysis software can be used to analyze the concentration and distribution of organic pollutants during continuous detection. The device and method provided by the application achieve layered continuous detection of organic pollutants in soil, overcoming the high cost and long operation period of single-point measurement or profile measurement, reducing the test error caused by organic matter staining the sapphire glass window, and significantly improving the convenience and test accuracy of organic pollutant detection in soil.

This invention relates to the field of jadeite testing technology, and more particularly to a method for determining the commercial attributes of jadeite based on ultraviolet fluorescence microstructure. This invention, for the first time, combines microscopic observation with ultraviolet excitation for a more accurate determination of the commercial attributes of jadeite. New jadeite (Grade A) typically does not emit ultraviolet fluorescence; while both natural Grade A old jadeite and treated jadeite exhibit ultraviolet fluorescence, natural Grade A old jadeite has a clearly defined ultraviolet fluorescence morphology corresponding to a dotted, reticulated, ternary composite structure; whereas treated jadeite, due to strong acid and alkali corrosion, exhibits a blurred, vein-like network pattern and clustered, patchy ultraviolet fluorescence morphology. This addresses the current problem in commercial inspection where the presence of blue-white ultraviolet fluorescence is used to misclassify wax-containing natural Grade A old jadeite as Grade B or B+C jadeite. This provides a new direction and approach for more accurate determination of the commercial attributes of jadeite and the development of related commercial inspection equipment.

The invention discloses a quantitative characterization method and device based on ultraviolet fluorescence response spatio-temporal topology analysis, and relates to the technical field of water body detection.The method comprises the steps that ultraviolet image sequence data of a target area is obtained, and an ultraviolet image time sequence data set is generated through time sequence arrangement and space alignment processing; traversing the fluorescence intensity sequence of each spatial pixel unit, determining first fluorescence response time according to a preset response judgment condition, and generating a label set; an ultraviolet fluorescence space-time topological graph is constructed based on the space adjacency relation, a space pixel unit is used as a topological node, and the first fluorescence response time difference is used as an edge weight; by performing path search on spatio-temporal topological data, determining a response propagation path set, calculating time gradient information and generating a quantization result vector, the problem of spatio-temporal behavior quantization caused by multi-starting-point and multi-branch propagation of ultraviolet fluorescence response in a water body ultraviolet sterilization process is solved; structured modeling and quantitative characterization of the fluorescence response propagation behavior are realized.

This invention relates to the field of image detection technology, specifically a machine vision-based method for detecting welding defects in the conductive layer of copper busbars. The method includes: constructing a multispectral imaging mechanism to acquire images of the area to be detected; automatically switching the current light source combination based on the image acquisition scene and real-time image quality to obtain a multispectral image; processing the multispectral image to identify oxide layer boundaries and thickness distribution; separating the oxide layer, copper substrate, and suspected defect areas by combining the channel brightness ratios between each light source, and globally enhancing each area to obtain a globally enhanced image; using an oxide layer texture removal model to remove oxide layer texture from the globally enhanced image, restoring a clear substrate image; extracting multi-scale features of suspected defect areas from the clear substrate image, filtering out key defects using a defect recognition model, and performing local enhancement; and classifying key defects by combining green light morphology features, infrared temperature features, and ultraviolet fluorescence features.

The invention discloses a disease risk dynamic assessment method and system based on multi-source data fusion. The method comprises the following steps: acquiring road video, acceleration, GPS, streetscape image, text description, multispectral and ultraviolet fluorescence data and meteorological information to obtain initial data; the initial data is subjected to feature extraction to generate damage fingerprint vectors, the damage fingerprint vectors are converted into exposure flux, integration is accumulated to obtain inhalation dose, relative disease risks are calculated in combination with a dose-reaction model, the dose-reaction model fits out corresponding parameters by analyzing the relation between historical disease data and environmental exposure dose, and the relative disease risks are calculated. And the relative disease risk is calculated in combination with the current inhalation dose and the attenuation characteristic of the risk along with time. The early warning information is divided into four grades according to the relative disease risks, and is displayed through a visual platform and pushed through multiple channels. By implementing the method, multi-source data can be fused in real time, and the disease risk can be accurately evaluated.

This application discloses a method and system for deep ultraviolet fluorescence spectroscopy testing of wide bandgap semiconductors, relating to the field of semiconductor material detection technology. The method includes: acquiring a wide bandgap semiconductor sample; emitting deep ultraviolet excitation light from a deep ultraviolet light source onto the wide bandgap semiconductor sample to excite electron-hole pairs, which recombine to generate a fluorescence signal; wherein the photon energy of the deep ultraviolet excitation light is greater than the bandgap of the wide bandgap semiconductor sample; detecting the fluorescence signal and performing spectral analysis on the detected fluorescence signal to obtain electronic energy level structure information related to defects and impurities in the wide bandgap semiconductor sample. This application utilizes the characteristic that the photon energy of the deep ultraviolet excitation light is greater than the bandgap of the wide bandgap semiconductor sample to achieve efficient excitation of intrinsic and defect states.

The application provides a fluorescent metal organic framework material, a preparation method thereof and a detection method of magnetic substance content in a secondary battery negative electrode material, and belongs to the technical field of metal organic framework materials. The chemical formula of the fluorescent metal organic framework material is Ln2L3xH2O, wherein the inorganic metal center Ln is at least one of lanthanide metals, the organic ligand L has a diphenic acid structure, and x is 0-3. The fluorescent metal organic framework material has specific response to Fe 3+ and Cr 3+ magnetic substances, and exhibits the characteristics of rapidness, high selectivity and high sensitivity, and can detect the magnetic substances through an ultraviolet fluorescence (UV-vis) method.

This utility model relates to the technical field of flue gas treatment equipment, and discloses a flue gas smelting desulfurization device, including a desulfurization tower. A water tank and a circulating pump are fixedly installed on the outside of the desulfurization tower. The circulating pump is electrically connected to an external main controller via a connecting line, and the input end of the circulating pump is connected to the water tank via a pipe. Multiple material racks are fixedly installed inside the desulfurization tower, and a spray mechanism is fixedly installed at the lower end of the material racks. The spray mechanism is connected to the output end of the circulating pump via a pipe. A fixing ring is also fixedly installed between two of the material racks. An installation cylinder is set inside the desulfurization tower, and multiple sector plates are rotatably installed inside the installation cylinder via a rotating shaft. The rotating shaft, in conjunction with a helical gear, a support ring, a drive ring, and a motor, rotates, thereby achieving synchronous rotation of multiple sector plates within the installation cylinder. Combined with an ultraviolet fluorescence detection device inside the desulfurization tower, the output gas volume can be adjusted according to the sulfur content in the flue gas to ensure effective treatment of high-sulfur flue gas.

The application discloses a kind of based on image recognition's demolition garbage aggregate classification method, belong to demolition garbage processing technical field.The application collects the visible light image of aggregate, ultraviolet induced fluorescence image and infrared thermal image under pulse thermal excitation, shape class and shape irregularity index are extracted from visible light image, mortar coverage is extracted from ultraviolet fluorescence image, and microcrack density is extracted from infrared thermal image;Then determine shape grade and defect grade, fuse and output first to fourth level classification label.The application also identifies red brick particles through near-infrared reflectance spectroscopy, and distinguishes demolition induced cracks from original microcracks using thermal decay characteristics.The application realizes comprehensive, rapid and automated evaluation of aggregate shape, surface mortar, internal cracks and impurities, and the classification results can directly guide the utilization of aggregate resources, effectively improving the utilization rate of demolition garbage aggregate with high added value.

This invention discloses an integrated probe for air-induced ultraviolet fluorescence detection. A detachable snap-in filter (1) is installed at the light inlet of the front end of the cylindrical metal shield shell. A photomultiplier tube (2) is installed close to the back of the filter. A photomultiplier tube base (3) is set at the bottom of the photomultiplier tube (2). A photomultiplier tube base fixing plate (4) is set at the bottom of the photomultiplier tube base (3). The photomultiplier tube base fixing plate (4), the high voltage divider plate (7), the signal processing readout and power supply board (8), and the hollow fixing plate (9) are connected by support columns (6) and fixed with support column fixing screws (5) on both sides. This invention solves the technical problem that existing photon counting detection equipment is difficult to balance low cost, low noise, and compact structure in the application scenario of ultraviolet fluorescence remote sensing induced by radioactive nuclides in the air.

This invention relates to the field of pipe fitting inner wall inspection technology, and discloses a method for detecting the cleanliness of the inner wall of stainless steel pipe fittings based on intelligent sensors. The method includes: using a multi-sensor progressive fusion discrimination technology based on high-speed continuous imaging, polarized light, ultraviolet fluorescence, and mechanical micro-perturbation to achieve high-precision intelligent differentiation of bubbles and particles and a detection effect with an extremely low false judgment rate; using digital twin virtual-real response mapping and production process root cause tracing technology to achieve self-diagnosis of the detection system status, accurate location of abnormal process parameters, and pre-demonstration optimization of new specification strategies; and using thermal-fluid-solid-electric multi-physics field coupling evolution prediction and real-time feedback technology of upstream processes to achieve early warning of pollutant risks, preventive elimination of stubborn stains, and closed-loop self-evolutionary control of manufacturing quality.

The application discloses a quantitative method for oil pollutants in water based on ultraviolet fluorescence characteristic spectrum, and belongs to the technical field of water quality detection, and comprises the following steps: collecting multi-angle polarization-induced spectra of a water sample to be detected at multiple preset wavelengths as an initial fluorescence spectrum set; after spectrum peak position correction, performing multi-dimensional feature modulation on the corrected spectrum set to generate a composite structure characteristic spectrum; using a pre-constructed atlas correlation model to perform group matching analysis, obtaining oil component spatial distribution data, and performing feature morphological dynamic fitting on the composite structure characteristic spectrum to obtain a feature peak correction spectrum; and calling a pre-trained concentration inversion network to inversely calculate the concentration values of the oil components from the feature peak correction spectrum. Through multi-angle polarization excitation and multi-dimensional feature modulation, and in combination with atlas correlation and dynamic peak shape fitting, the method realizes efficient analysis and accurate quantification of overlapping fluorescence signals in complex oil mixtures.

The invention relates to the technical field of meteorological ecological observation, biological safety detection, environment monitoring and the like, and discloses a biological aerosol automatic identification system and method based on ultraviolet fluorescence imaging, and the system comprises an environment control module, an aerosol sampling module, an adhesive tape transmission module, an ultraviolet microscopic imaging module and a control and data processing module. The environment control module is used for constructing a constant-temperature closed optical darkroom; the aerosol sampling module captures biological particles in the air on the surface of a carrier adhesive tape by utilizing an acceleration nozzle and an inertial impact principle; the adhesive tape transmission module realizes automatic transfer of a sample from a sampling position to a detection position through stepping control; the ultraviolet microscopic imaging module adopts a coaxial incident light path structure and is matched with a dichroic spectroscope and an optical filter to separate exciting light and fluorescence signals. According to the invention, full-process automatic in-situ monitoring of the biological aerosol is realized, the problem of background interference is effectively solved, and the real-time performance of detection and the recognition accuracy are improved.

The invention discloses an anti-ultraviolet fluorescent composite film and a preparation method thereof, and belongs to the technical field of polymer functional films. The preparation method comprises the following steps: mixing polyvinyl alcohol, a magnesium-doped carbon quantum dot solution and a plasticizer, and heating and dissolving to form a homogeneous solution; and carrying out defoaming, membrane preparation and drying treatment on the homogeneous solution to obtain the final ultraviolet-proof fluorescent composite membrane. Wherein the magnesium-doped carbon quantum dot solution is prepared from potato powder and water-soluble magnesium salt through a hydrothermal reaction. The ultraviolet-proof fluorescent composite film provided by the invention is non-toxic, and has good biocompatibility and biodegradability.

The application relates to the field of impurity detection, in particular to an impurity monitoring method and device based on ultraviolet fluorescence, equipment and medium. The method comprises the following steps: acquiring the liquid category of a liquid to be detected, and determining at least two groups of ultraviolet data based on the category for detection, which is highly flexible. Different liquids may have different ultraviolet absorption characteristics, so that a detection scheme customized for a specific liquid category can more accurately reflect the impurity condition in the liquid. In addition, the light-emitting module is designed to be rotatable, the light-emitting angle can be adjusted according to the detection requirement, the liquid can be detected multiple times, multiple sets of detection results can be received and comprehensively judged, the accuracy of impurity detection can be further improved, the possibility of false positives and false negatives can be reduced, the whole process from sample preparation to result output can be completed without manual intervention, and the time cost and error risk caused by manual operation are reduced.

The invention discloses an automatic grading method and system for solar photovoltaic panel products, and relates to the technical field of automatic grading of photovoltaic panels. The automatic grading method for the solar photovoltaic panel product comprises the following steps: acquiring IV curve data and ultraviolet fluorescence image time sequence data of the solar photovoltaic panel product; performing electrical analysis processing on the IV curve data, and extracting an electrical attenuation characteristic value; and based on a pre-trained photovoltaic ultraviolet aging mapping model, performing ultraviolet feature decoding processing on the ultraviolet fluorescence image data to obtain an aging significant feature value, and performing comprehensive analysis on the aging significant feature value and an electrical attenuation feature value to obtain a recovery residual value score of the solar photovoltaic panel product. According to the invention, automatic grading processing is carried out on the solar photovoltaic panel product through grading of the recovery residual value, so that comprehensive evaluation of the recovery value of the photovoltaic panel is realized, and it is ensured that the grading result can truly reflect the actual state of the photovoltaic panel.

The application provides a super-bright TPU car cover with high light transmittance and refractive index and a preparation method thereof. The super-bright TPU car cover comprises a substrate layer, a high-refractive core layer and a low-refractive outer layer arranged on the surface of the substrate layer in sequence, the high-refractive core layer contains nano fillers grafted and modified by a silane coupling agent, and the nano fillers are arranged in a direction along the film surface, the low-refractive outer layer contains hollow nano particles, an intermediate layer is arranged between the high-refractive core layer and the low-refractive outer layer, and the intermediate layer comprises a reactive block copolymer. The application realizes light transmittance ≥ 92%, haze ≤ 1.0%, brightness improvement of more than 80% through a multilayer optical interference structure and arrangement of high / low refractive layers, in addition, the scratch hardness of the car cover reaches 2H, the color difference value ΔE is ≤ 1.5 after accelerated aging for 2000h in a QUV ultraviolet fluorescence aging tester, and the water boiling resistance is improved by 2 times.

The invention relates to an AI auxiliary defect positioning and image digital tracing system based on NDT field observation, and belongs to the technical field of nondestructive testing. The system comprises a host core processing unit, a touch interaction and image processing unit, a camera acquisition unit and a special tool auxiliary positioning unit, acquiring detection data parameters in real time, analyzing and judging surface defects of the part, recording a damage sample, and generating a damage identification result and an inspection process record data set; a touch operation signal is received, an image index database is constructed to achieve image retrieval, and a defect mark box can be drawn and associated, stored and generated into an image file with mark attributes; an ultraviolet fluorescent lamp provides a light source to capture damage traces; the postures of the parts are adjusted through the self-rotating tool and the mechanical arm tool, and non-blind area collection is ensured. Intelligent defect identification of NDT magnetic powder detection, full data tracing in the detection process and image digital management are achieved, and the method is suitable for detection of key parts such as aircraft wheel bolts and the like.

In a vegetation evaluation system using ultraviolet fluorescence and a vegetation evaluation method using same, the vegetation evaluation system comprises an optical device and a determination unit. The optical device obtains an RGB image or a vegetation index image for a first region, and obtains the RGB image or an ultraviolet fluorescence image for a suspicious region selected from the first region. The determination unit determines a vegetation state on the basis of the RGB image or the ultraviolet fluorescence image for the suspicious region.

This invention discloses a short-cavity ultraviolet fluorescence imaging system with a long working distance, comprising a lens sleeve, and further comprising a first positive meniscus lens, a first plano-convex lens, a second positive meniscus lens, a third positive meniscus lens, a plano-concave lens, and a second plano-convex lens, which are sequentially arranged coaxially within the lens sleeve along the fluorescence imaging direction. Along the fluorescence imaging direction, the two sides of the first positive meniscus lens are concave and convex, respectively; the two sides of the first plano-convex lens are planar and convex, respectively; the two sides of the second positive meniscus lens are convex and concave, respectively; the two sides of the third positive meniscus lens are convex and concave, respectively; the two sides of the plano-concave lens are concave and planar, respectively; and the two sides of the second plano-convex lens are convex and planar, respectively. This invention achieves a long working distance, high resolution, and compact ultraviolet imaging system through the combination of a spherical lens and a microscope. Compared to existing spherical lens systems, the optical path is significantly reduced, and compared to aspherical lens systems, the cost is lower.