557 results about "Astigmatism" patented technology

The invention belongs to the technical field of optical detection, and particularly relates to a global power wave aberration prediction-based Ritchey-Common detection method and system, and the method comprises the steps: firstly building a three-dimensional optical model through the parameters of a standard spherical mirror, a to-be-detected plane mirror and an interferometer, and combining a preset Ritchey angle and an out-of-focus / astigmatism coefficient, injecting vibration and temperature noise by using Monte Carlo simulation to generate an enhanced training data space; secondly, constructing a phase error adjustment model based on an adversarial network, and decoupling a mapping relation between an adjustment error and wave aberration distortion through a multi-scale attention mechanism and a radial basis function network to realize adaptive correction of sub-aperture phase data; and finally, splicing sub-aperture phases by using a graph neural network and fusing multi-angle full-aperture measurement data to accurately reconstruct the surface shape of the plane mirror to be measured. According to the invention, through confrontation training and dynamic error compensation of physical constraints, the detection efficiency and reliability of the large-aperture optical element are significantly improved.

The invention discloses a stray light gray value acquisition method, an automatic focusing processing method and an automatic focusing processing system, and relates to the field of automatic focusing. The method is applied to the microscopic automatic focusing device, and comprises the following steps: adjusting the distance between a microscope objective and a reflection point corresponding to light passing through the microscope objective, or the reflection angle of the light, so that the adjusted distance or reflection angle exceeds the focusing range of the microscope objective; or an extinction assembly is additionally arranged on the outer side of the microscope objective, so that the light penetrating through the microscope objective is eliminated; theoretical light spot areas formed by stray light on the surface of the first sensor at different axial height positions of the microscope objective are calculated; and gray values corresponding to theoretical light spot areas in the actual light spot images of the microscope objective at different axial height positions are extracted and used for correcting the light spot image of the object to be measured, so that the influence of stray light on a defocusing amount calculation result is reduced. Therefore, the influence of stray light reflected by the surface of the microscope objective on the defocusing amount calculation is reduced, and the accuracy of the defocusing amount calculation is improved.

An ophthalmic lens configured to correct and / or treat at least one condition of the eye (e.g., presbyopia, myopia, hyperopia, astigmatism, binocular vision disorders, night vision image quality, and / or visual fatigue syndrome) comprising: a base power profile; and at least one pulse selected to modify the base power profile.

The invention provides a visual system. The visual system comprises a lens cone, a lens group and a spacing element group, the lens group and the spacing element group are arranged in the lens cone, and the lens group is composed of four lenses, a polaroid, a reflective polarizing element, a quarter-wave plate and a reflective element. The four lenses are sequentially a first lens with positive focal power, a second lens with negative focal power, a third lens with negative focal power and a fourth lens with positive focal power from the first side to the second side; f23 / d3s is more than or equal to-9.75 and less than or equal to-8.72; f / (CP1 + EP13) is more than 5.00 and less than 5.40. The problem that stray light is serious due to the fact that a four-piece type visual system in the prior art is provided with a bonding lens and a reflecting part to meet the requirement for structure compactness is solved.

The invention provides a structure and method for bonding plane mirrors and calibrating angles at the same time, and relates to the technical field of aviation, the structure comprises a frame, an infrared turn-back assembly, a flexible lens pressing ring, a mirror frame, a mirror and a pin gauge, the flexible lens pressing ring and the mirror frame are used for axially positioning the mirror, and the pin gauge is arranged in the radial direction of the mirror. When the glue is injected, the area and the thickness of the glue are accurately controlled, the tension generated on the mirror surface of the reflector after the glue is cured is uniformly distributed, the surface precision of the reflector is ensured, the arrangement of the cover plate can effectively prevent light leakage, stray light is prevented from influencing the imaging quality, and the technical problem that the surface precision is reduced when an existing reflector is installed is solved.

The invention discloses a method and a device for detecting errors of a rotary table and a rotary shaft of an overall measurement light path connected upper rotary shaft type laser tracker, and belongs to the technical field of laser tracking measurement. The device comprises a microscope, a fluorescent microsphere, a substrate and a six-dimensional precision calibration displacement table, the microscope is located above the fluorescent microsphere, and the six-dimensional precision calibration displacement table is located above the substrate. The fluorescent microspheres are fixed on the substrate, and the substrate is fixed on the six-dimensional precise calibration displacement table. By combining the fluorescence microscope with the astigmatism imaging function, the precise displacement table, space coordinate calculation and other operations, the determination of the axis space linear equation of the upper and lower rotary tables of the whole measurement light path connected upper rotary shaft type laser tracker and the detection of the shaft radial runout in a complete rotation period are realized under one coordinate system; a necessary technical foundation is laid for realizing error compensation of the rotary table and the rotary shaft of the rotary shaft type laser tracker connected with an overall measurement light path and improving the tracking precision and the stability of the laser tracker.

The invention provides a linear optical tweezer astigmatism field regulation and control method based on an optical transmission matrix. The design method comprises the following steps: establishing a 4 * 4 optical matrix for generating a linear optical tweezer astigmatism field and a transmission equation; analyzing the regulation and control rule of the parameters of the optical element on the astigmatism characteristics; collecting a fluorescence slice image of the initial astigmatic light field through an axial tomography scanning method; reconstructing the spatial distribution of the initial image light field; judging whether the light field accords with a preset astigmatism characteristic or not, if not, determining the astigmatism characteristic to be optimized, and adjusting element parameters according to a regulation and control rule; and acquiring the adjusted image of the astigmatism light field again, reconstructing the image, and continuously performing judgment iteration until the image accords with the preset astigmatism characteristic, thereby realizing regulation and control of the astigmatism light field. Matrix optics is used in optimization of a linear optical tweezer image dispersion light field optical system, the limitation of traditional trial and error design is avoided, the method can be applied to the fields of light control technology, light sheet fluorescence microscopic imaging and the like, and the performance of the optical system is improved.

A method for correcting nonuniformity of a near-eye display (NED) includes: obtaining a first plurality of images in response to a first test pattern being displayed by a display of the NED, each of the first plurality of images being obtained at a different location adjacent to an end of an optical path coupled to the display; extracting a distinguishing frequency component among the first plurality of images, the distinguishing frequency component being at least caused by stray light introduced by the optical path; and determining a correction scheme for correcting nonuniformity of the NED based on the distinguishing frequency component.

The invention discloses a receiving module, a radar, a terminal and a vehicle end, and relates to the technical field of laser radars. Wherein the receiving module comprises an optical element and a detector, and the receiving module is used for receiving a linear light beam extending along a first direction. The optical element is used for astigmatism of the first light beam in the second direction and / or field curvature of the first light beam. The detector receives the light beams passing through the optical element through the plurality of monitoring areas, and the detector is located at a target focal plane of the optical element. According to the invention, the dynamic range of imaging can be ensured through the diffusion of the first light beam in the second direction by astigmatism and the diffusion of the edge view field light beam by field curvature. According to the optical element provided by the invention, the detector is arranged at the target focal plane of the optical element, and the configuration of the pixels on the detector is combined, so that the receiving module has a high-resolution receiving capability, and therefore, the optical element provided by the invention does not need a complicated manufacturing process, is simple in structure and low in manufacturing cost, and can realize the low-cost design of a high-resolution laser radar.

The invention relates to a coaxial four-mirror optical system, which comprises a primary mirror, a secondary mirror, a third mirror, a fourth mirror and an annular diaphragm, all the mirrors and the annular diaphragm are coaxially arranged, both the secondary mirror and the third mirror are provided with light through holes, light is reflected by the primary mirror and then is reflected by the secondary mirror, the third mirror and the fourth mirror in sequence, and the light is reflected by the annular diaphragm. And finally converging and imaging. In the design, through application of the annular diaphragm, edge aberration is reduced, and stray light suppression capability is remarkably enhanced at the same time. The coaxial four-mirror optical system has the advantages of being compact in structure, high in imaging quality, wide in applicability and the like, and is suitable for being applied to multiple fields of aerospace, biomedicine, industrial detection and the like.

Described are toric contact lenses that contain high energy visible (HEV) light absorbing compounds and their use for improving various vision attributes in astigmatic contact lens wearers, such as brightness perception and visual range.

The invention discloses a stray light removing system of a diffractive optical element for beam splitting, which comprises a laser light source, the diffractive optical element for beam splitting, a first focusing element, a diaphragm, a second focusing element and a third focusing element which are sequentially arranged along the direction of a laser light path, and is characterized in that the diffractive optical element is used for splitting incident light into a plurality of sub-beams; a plurality of light through holes used for removing stray light are formed in the diaphragm corresponding to the plurality of sub light beams, the focal lengths of the first focusing element and the second focusing element are the same and are F, the distance between the diaphragm and the first focusing element and the distance between the diaphragm and the second focusing element are the same and are L, and L is equal to F. By forming a 4f filtering system, stray light of each sub light beam is effectively removed, and under the condition that the transmission characteristic of light is not changed, the whole structure is simple, operation is convenient, the yield of machined products is guaranteed, and cost is saved.

The invention relates to the technical field of myopia prevention and control, and discloses a correction and training integrated lens and glasses based on retina signal gradient remodeling. The lens substrate is divided into a vision correction area located in the center and a multi-dimensional three-dimensional asymmetric optical signal field extending outwards in a gradient mode around the vision correction area. The multi-dimensional stereoscopic asymmetric optical signal field comprises 10000-26000 asymmetric signal field independent units and 400-1500 stereoscopic structure protrusions, wherein the asymmetric signal field independent units are formed on the concave surface of the lens substrate through laser engraving, the diameter range of the asymmetric signal field independent units is 100-300 microns, and the stereoscopic structure protrusions are formed in a protruding mode, and the diameter range of the stereoscopic structure protrusions is 0.5-2 mm. And 4-12 asymmetric signal field independent units are distributed on each three-dimensional structure bulge. The lens does not induce or increase astigmatism due to the structure of the lens, and can relieve the over-stimulation of long-time close-range eye use and abnormal environment illumination signals on the retina, so as to slow down the over-growth of the ocular axis.

The invention relates to a refractive error detection system and method. The refractive error detection system comprises a plurality of lens assemblies and a mobile terminal device. Wherein the multiple groups of lens assemblies are arranged on the front surface or the rear surface of the mobile terminal equipment and are in communication connection with the mobile terminal equipment; wherein each group of lens assemblies comprises a flash lamp, a first camera and a second camera which are arranged along the astigmatism meridian corresponding to each group of lens assemblies, and the lens assemblies are used for collecting eye images; and the mobile terminal equipment is used for inputting the eye image into the completely trained refractive error detection model and acquiring a refractive error detection result output by the refractive error detection model. Through the method and the device, the problems of relatively high detection cost and relatively low detection efficiency of the refractive error in related technologies are solved, and the technical effects of reducing the detection cost of the refractive error and improving the detection efficiency of the refractive error are achieved.

The utility model relates to the technical field of automatic production of contact lenses, in particular to liquid injection and mold closing equipment for light diffusion sheets of contact lenses, which comprises a temporary storage dust removal mechanism for temporarily storing an upper mold, a rotary pickup mechanism for carrying and rotating the upper mold, and a mold closing module for driving the rotary pickup mechanism to move, during rotary mold closing, an upper mold is carried to the temporary storage dust removal mechanism, the temporary storage dust removal mechanism carries out dust removal on the upper mold and then temporarily stores and places the upper mold, the mold closing module drives the rotary picking mechanism to reach the temporary storage dust removal mechanism to obtain the upper mold, the rotary picking mechanism rotates the upper mold to a specified angle, and the mold closing module drives the rotary picking mechanism to place the upper mold on the lower mold. Mold closing is completed; according to the utility model, the overall structure is compact, the functions of temporary storage, dust removal, rotary alignment and placement and die assembly are integrated, and the rapid rotary alignment of the contact lens astigmatism sheet can be completed without redundant turnover and complex actions, so that the processing automation of the astigmatism sheet is improved, and the production and processing efficiency of the contact lens is improved.

The invention discloses an objective lens for wafer surface defect detection, and relates to the technical field of optical devices, the objective lens comprises three lens groups which are sequentially arranged according to the light incident direction, and the focal powers are respectively positive, negative and positive; the first lens group comprises a first lens with positive focal power, a second lens with negative focal power and a third lens with positive focal power, and the second lens group comprises a fourth lens with positive focal power and a fifth lens with negative focal power. The third lens group comprises a sixth lens with negative focal power, a seventh lens with positive focal power and an eighth lens with positive focal power, and the objective lens formed by arranging the lenses can correct various imaging differences, especially distortion, field curvature, astigmatism, axial chromatic aberration and chromatic aberration of magnification in the process of wafer detection imaging, so that the imaging quality is improved. The high resolution ratio and the large view field are achieved, the view field reaches 40 mm, the theoretical resolution ratio sigma is 3 microns, and the wafer detection efficiency can be greatly improved.

The utility model discloses a wide-angle optical system and optical equipment, and relates to the technical field of optics. The first lens comprises a first mirror surface and a second mirror surface, the first mirror surface is a convex surface, and the second mirror surface is a concave surface; the second lens comprises a third mirror surface and a fourth mirror surface, and the third mirror surface and the fourth mirror surface are convex surfaces; the third lens comprises a fifth mirror surface and a sixth mirror surface, and the fifth mirror surface and the sixth mirror surface are convex surfaces; the fourth lens comprises a seventh mirror surface and an eighth mirror surface, the seventh mirror surface is a concave surface, and the eighth mirror surface is a convex surface; the photoelectric sensor is arranged on one side of the eighth mirror surface, the view field angle of the lens is 180-200 degrees, the relative aperture is 2.0-2.8, the diameter of a defocused spot is smaller than 4 microns, and the relative light transmission is larger than 50%. According to the technical scheme of the utility model, only four lenses are adopted, so that the overall size of the lens is greatly reduced; the number of the lenses is reduced, spherical aberration, coma, astigmatism, chromatic aberration and the like can be effectively corrected, the debugging difficulty is reduced, and the production cost is reduced.

The invention provides a system and method for eliminating secondary diffraction spectrum influence of a grating spectrum system, and belongs to the field of grating spectrums.The eliminating system comprises a second filter, a third filter and double slits, the second filter and the third filter correspond to one slit in the double slits respectively, and the second filter and the third filter correspond to the other slit in the double slits respectively. The central wavelength and the passband width of the second filter plate and the third filter plate are matched with the slit distance of the double slits, separation of a second-level diffraction spectrum and a first-level diffraction spectrum is realized by utilizing the matching and design of the double slits and the optical filters, and the influence of the second-level diffraction spectrum of the grating spectrometer is eliminated. According to the invention, an optical filter does not need to be used for suppressing a secondary spectrum, so that the transmittance of the system is improved, the reflected light of the detector protection glass cannot be reflected by the optical filter to form relatively strong stray light, and the stray light formed by secondary diffraction light is reduced.

The invention discloses an OCT (optical coherence tomography) imaging catheter, an imaging probe and a manufacturing method of the imaging probe, and relates to the technical field of medical instruments. The imaging probe comprises an optical fiber and a reflecting lens, the reflecting lens is arranged at the far end of the optical fiber, and the reflecting lens is provided with a reflecting surface and a light emitting surface; in the radial direction of the imaging probe, the projection of the reflecting surface is arc-shaped, the tangent plane of the reflecting surface intersects with the center line of the optical fiber and forms an included angle with an opening facing the far end of the optical fiber and the non-light-emitting surface side, and the included angle is an acute angle. According to the OCT imaging catheter, the imaging probe structure of the OCT imaging catheter is improved, the curved conical lens is adopted, efficient focusing of light beams is achieved, fine light spots can be formed, astigmatism is reduced, and the imaging quality is improved. The structure is convenient to miniaturize and flexible to bend, and the spatial resolution of the probe is improved.

An aberration correction device that corrects an aberration of an optical system includes: a first multi-pole lens configured to generate a first 6-pole field; a second multi-pole lens configured to generate a second 6-pole field; a first deflector configured to generate a first deflection field; and a second deflector configured to generate a second deflection field. The first deflector is arranged at a position of a beam cross between the first multi-pole lens and the second multi-pole lens, and the second deflector is arranged between the first deflector and the first multi-pole lens or the second multi-pole lens. The aberration correction device returns, by the second deflector, a beam deflected by the first deflector, allows the beam to pass through at least one center of the first multi-pole lens or the second multi-pole lens, and accordingly, corrects at least one of a 2-fold symmetric first-order astigmatism (A1) aberration or a 5-fold symmetric fourth-order astigmatism (A4) aberration.

This utility model provides a visual safety guidance device for highway tunnels, relating to the technical field of tunnel guidance devices. It includes a mounting frame installed at the top of the tunnel facing the centerline of the wall at the diversion point, and several reflective modules mounted on the mounting frame. The mounting frame has inverted buckle portions on both sides of its bottom, and recessed holes are equidistantly spaced on the mounting frame, with spring bolt assemblies installed within these recessed holes. Each reflective module consists of a mounting base and a reflector, which are fixed together by bolts. The mounting base has a snap-fit ​​groove extending to both ends on one side corresponding to the recessed hole. This device is installed at the top of the tunnel, connecting to the diversion point at the tunnel's front end. Through the tunnel's lighting and the reflection from the reflectors, it effectively guides the driver's line of sight at the tunnel's front end, preventing collisions caused by obstructed vision or momentary distraction, especially for drivers with poor vision or astigmatism.

The invention discloses virtual image detection equipment, which comprises a front diaphragm; the front lens group is arranged on the second side of the front diaphragm along the optical axis; a rear lens group disposed on a second side of the front lens group along the optical axis; the relay lens group sequentially comprises a relay front group and a relay rear group from the first side to the second side along the optical axis, and the relay front group and the relay rear group are coaxially and fixedly arranged; the refraction adjusting group comprises a first moving component arranged between the relay front group and the relay rear group and a second moving component arranged in the relay rear group; the first moving component comprises a cylindrical mirror which is arranged on the optical axis in a switchable and back-and-forth moving manner, and is used for adjusting the astigmatism diopter; the second moving component is arranged on the optical axis in a front-back moving mode and used for adjusting the diopter of the spherical surface. And the light receiving assembly is arranged on the second side of the relay lens group along the optical axis and is used for receiving the light from the relay lens group to carry out virtual image detection.

The optical detection system and method for suppressing stray light provided in this application include an illumination optical path and an imaging optical path sharing a common objective lens. An illumination beam transmitted along the illumination optical path illuminates the wafer under test through the objective lens and is reflected by the wafer under test to form an imaging beam. The imaging beam is transmitted along the imaging optical path through the objective lens for imaging. By arranging optical wedges in the illumination optical path, the illumination beam is incident at a non-parallel or non-coincident angle to the optical axis of the objective lens. Back-reflected stray light generated by multiple reflections between the lenses inside the objective lens is removed from the imaging optical path, which significantly suppresses back-reflected stray light and eliminates the influence of stray light inside the objective lens on imaging.

This invention relates to the field of precision alignment technology, specifically to an astigmatic differential confocal alignment system and method capable of synchronous imaging. The astigmatic differential confocal alignment system includes: an astigmatic differential confocal optical path system and an imaging optical path system sharing the same objective lens; the astigmatic differential confocal optical path system includes a laser, a collimating and expanding beam system, a polarizing beam splitter cube, a quarter-wave plate, a long-pass filter, a short-pass dichroic mirror, an objective lens, a non-polarizing beam splitter cube, a plano-convex cylindrical lens, and two four-quadrant photodetectors connected in sequence; the imaging optical path system includes a visible light point source, a beam splitter, a short-pass dichroic mirror, an objective lens, a sleeve lens, and a camera connected in sequence; the two optical path systems are coaxial and synchronized. When the defocus error signal FES crosses zero, the camera synchronously acquires a clear morphological image of the surface of the sample under test, achieving synchronization of alignment and imaging.

The invention discloses a large-view-field compound eye telescopic system suitable for daytime observation, and belongs to the technical field of optical system design. The system comprises a primary mirror, a compound eye optical unit, a refraction correction mirror group unit and a photoelectric detector unit which are sequentially arranged along an optical axis. The compound eye optical unit adopts a light splitting reflection cube-corner prism structure, and divides a focal plane of a primary lens into X paths of sub-view fields; the refraction correction lens group unit comprises n correction lens groups with built-in field diaphragms; a concentric annular light barrier group is arranged on the inner wall of the primary mirror chamber. Large-view-field observation is realized through optical splicing of a compound eye structure, strong background stray light in the daytime is remarkably inhibited by utilizing a built-in view field diaphragm and combining multiple scattering absorption of a light barrier group, and the stray light coefficient of the system is lower than 1.11 * 10 <-7 >. The technical problem that an existing optical telescope cannot carry out high-contrast large-view-field observation in the daytime is solved, and all-weather monitoring of near-earth celestial bodies is achieved.

The utility model discloses a kind of visual calibration device of astigmatism eye focal line, comprising: axial position scale board, board face is printed with E-type visual target for distant visual detection;Cross visual target disc, coaxially rotatably embedded in through-hole;Several groups of pinholes, each group is arranged along visual target line two sides straight line, pinhole center connecting line is parallel with corresponding visual target line;Fixed shaft is through cross visual target disc center, and is mechanically connected with transmission device;LED light source, set in axial position scale board back surface.The utility model has beneficial effect: the utility model can provide clear and visible and invariable measured astigmatism eye objective existence astigmatism focal line of the person being examined, and can accurately determine the clear criterion that cross visual target line coincides with the focal line, so as to maximumly improve the accuracy of astigmatism eye astigmatism axial calibration, reduce the deviation of calibration astigmatism axial direction and actual astigmatism axial direction, improve determination accuracy and determination work efficiency.

An information processing device (110) comprises: an optical calculation unit (112) that calculates each of the optical path of light from an imaging field of view in an imaging device that performs imaging using an optical element and the optical path of light from outside the imaging field of view that is outside the imaging field of view, calculates stray light produced by the optical element and a point spread function (PSF) of the optical element, and generates a degraded image in which the stray light and the PSF are applied to an ideal image that is handled as correct answer data in teacher data; a noise image generation unit (113) that generates a noise image including noise predicted to occur in an imaging element of the imaging device during imaging; an image calculation unit (114) that superimposes the noise image on the degraded image to generate a learning image; and a teacher data generation unit (115) that generates teacher data in which the learning image is employed as training data and an image corresponding to the imaging field of view of the imaging device within the ideal image is employed as correct answer data.

The present application provides an optical lens system, comprising: five lenses, the five lenses comprising a first lens to a fifth lens in sequence from an object side to an image side; a plurality of spacers, the plurality of spacers comprising a fourth spacer located on the image side of the fourth lens and in contact with the image side surface of the fourth lens; a lens barrel for accommodating the lenses and the spacers; the Abbe number V4 of the fourth lens and the Abbe number V5 of the fifth lens satisfy: -40 < V4-V5 < -30; the effective focal length f4 of the fourth lens, the effective focal length f5 of the fifth lens, the inner diameter d4s of the object side surface of the fourth spacer, the outer diameter D4m of the image side surface of the fourth spacer satisfy: -1 < (d4s*D4m) / (f4-f5) < 3; the curvature radius R7 of the object side surface of the fourth lens, the curvature radius R8 of the image side surface of the fourth lens, the thickness CP4 of the fourth spacer, the air gap T45 of the fourth lens and the fifth lens on the optical axis, the central thickness CT5 of the fifth lens satisfy: -40 < (R7+R8) / (CP4+T45+CT5) < -18. The present application solves the problem that the rear-end system of the optical lens system in the prior art is prone to stray light.

A firearm-scope-attachable diopter lens device is provided. The device is comprised of an eyepiece-mounted optical accessory configured to affix securely over the eyepiece of a standard firearm scope without requiring any permanent modification to the scope itself. The device comprises a housing with at least one optically-aligned diopter lens, available in a range of diopter strengths to correct myopia, hyperopia, or astigmatism. In certain embodiments, the lens is installed in a removable cartridge that interfaces with the housing via a fastener such as a magnetic ring, twist-lock, or bayonet mechanism. Selective lens tinting may be applied to enhance contrast and reduce glare in varying light conditions. An optional micro-adjustment ring concentrically aligned with the lens permits fine diopter calibration in increments of ±0.25 diopters. A protective flip-up cap with a silent hinge mechanism and optional locking feature is integrated to shield the lens from debris when not in use.

The application discloses a high-resolution oblique-axis optical lens, comprising, from the object side to the image side, a first lens, a second lens, a third lens, a fourth lens, a diaphragm, a fifth lens, a sixth lens, a seventh lens, an eighth lens, a ninth lens, a protective glass and an image sensor; the first lens is a filter; the second lens is a biconvex spherical lens with positive focal power; the third lens is a spherical lens with negative focal power; the fourth lens is a spherical lens with positive focal power; and the fifth lens is a biconcave spherical lens with negative focal power. The technical scheme balances and corrects optical aberrations of all levels by reasonably distributing the focal power of the lenses, reasonably matching the optical materials and shapes, and utilizes the cylindrical lens to correct astigmatism caused by the optical path of the meridian arc vector plane of the protective glass, so that the advantages of large target surface, low distortion, ultra-short object distance, high resolving power and the like of the lens are achieved.