501 results about "Aspheric lens" patented technology

The invention relates to a 400G DR4 silicon optical chip, which is characterized in that one input end of a 2 * 2 coupler is coupled with an input waveguide, the other input end of the 2 * 2 coupler is coupled with one of four output waveguides, the output waveguide coupled by the 2 * 2 coupler reversely splits light to enter the 2 * 2 coupler, and the output waveguide is coupled with the other input end of the 2 * 2 coupler; light of each output end of the 2 * 2 coupler is divided into the two MZM modulators at equal ratio, and the four MZM modulators are respectively coupled with the four output waveguides. A 400G DR4 silicon optical module is characterized in that a light emitting end is coupled with an input waveguide of a 400G DR4 silicon optical chip through an aspheric lens and an optical isolator in sequence, and four output waveguides of the 400G DR4 silicon optical chip are coupled with a multi-channel optical fiber array. The beneficial effects are that even if the MPD and the MPD current amplification circuit are not provided, when the MPD current amplification circuit is applied to the optical module, the aspherical lens and the multi-channel optical fiber array can be coupled at the optimal position.

The invention relates to the technical field of optical detection, in particular to an aspheric lens laser interference detection adjustment error separation system and method, and the method comprises the steps: placing an aspheric lens on a clamping platform, carrying out the multiple laser interference measurement through adjusting different pitch angles and azimuth angles, and collecting a multi-angle interference fringe image; for different installation and adjustment error types, key features of typical error fringe images are extracted and compared with current interference fringe images, and identification of the installation and adjustment error types and levels is achieved; a mathematical model of various installation and adjustment errors is constructed, polynomial parameterization representation is adopted, installation and adjustment compensation parameters are reversely solved according to an identification result, and installation and adjustment are completed; and repeating the measurement and analysis process, and constructing an error adjustment frequency optimization model until the precision requirement is met. The method provided by the invention can improve the adjustment efficiency and precision of the aspherical lens.

The application discloses a multi-marked endoscopic imaging lens for digestive tract, and belongs to the field of biomedical microscopic endoscopic imaging. The endoscopic imaging lens comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens and a seventh lens; the first lens focuses laser; the second lens is matched with the first lens to limit a light beam in an effective light aperture of the lens; the third lens corrects chromatic aberration; the fourth lens and the fifth lens are combined to correct aberration; the sixth lens adopts an aspheric lens to correct spherical aberration caused in a collimating and focusing system; and the seventh lens is matched with the sixth lens to correct chromatic aberration. The working spectral range of the microscopic objective lens group is 488-860 nm, the effective light aperture is less than 1.8 mm, the mechanical outer diameter is not greater than 2.6 mm, the numerical aperture at the object side or the tissue is 0.55, the imaging field of view is 450 microns, the magnification is 2.14 times, and the working distance is 84 microns. The effect of matching excitation and fluorescence spectrum of a clinically available fluorescence contrast agent is realized.

The invention relates to a medium-focus large-aperture long-flange video lens with a focal length of 50mm. The medium-focus large-aperture long-flange video lens comprises a first lens group, an iris diaphragm and a second lens group which are sequentially arranged along a light incidence direction of a light path, wherein the first lens group serves as an immovable fixed group, the focal power is positive, and the first lens group is composed of lenses L11-L17 which are sequentially arranged in the light incidence direction of a light path and comprises two groups of doublet lenses and a group of triplet lenses; the second lens group serves as a movable focusing group, the focal power is positive, and the second lens group is composed of lenses L21-L27 which are sequentially arranged in the light incidence direction of the light path and comprises two groups of doublet lenses and a glass aspheric lens; the focal length value f1 of the first lens group and the focal length value f2 of the second lens group satisfy 0.47 lt; f2 / f1lt; and 0.56% of the total weight. The lens achieves a large clear aperture, high MTF resolution, small distortion and reduced achromatism, is short in total optical length, and meets a camera module matched with a long flange back focus.

The utility model relates to a six-piece type side rear-view camera. An optical system of the camera is composed of a first lens, a second lens, a diaphragm, a third lens, a fourth lens, a fifth lens and a sixth lens which are sequentially arranged from left to right along a light incident light path. Under the condition that retroflexion caused by aspheric coefficients is not considered, the first lens is a meniscus concave negative lens, the second lens is a biconvex positive lens, the third lens is a biconvex positive lens, the fourth lens is a meniscus concave negative lens, the fifth lens is a biconvex positive lens, the sixth lens is a plano-concave negative lens, and all the lenses are made of glass materials. Wherein the first lens is a glass aspheric lens, and the third lens and the fourth lens form a balsaming lens group. While 3M clear imaging is realized, the number of sheets is relatively small and the appearance size is relatively small.

The utility model provides a glass-plastic hybrid optical system and a camera module using the same, the glass-plastic hybrid optical system is composed of eight lenses, one spherical glass lens, one aspheric glass lens and six plastic aspheric lenses are selected, and the refractive power and the surface type of each lens are reasonably configured. Therefore, the optical lens can have the advantages of being small in size, low in cost and large in aperture while having a large field angle range, can better capture detail information of an object, improves the detail capturing capability of the optical lens for shooting the object, improves the picture texture of the optical lens, improves the resolution ratio and imaging definition of the optical lens, and improves the imaging quality of the optical lens. Therefore, the requirements of people on wide angle and high-quality imaging of the motion camera can be met.

The zoom lens comprises a first fixed lens group, a zoom lens group, a diaphragm, a second fixed lens group, a focusing lens group and a third fixed lens group which are sequentially arranged from an object plane to an image plane along an optical axis, and the focal powers are respectively positive, negative, positive, positive, positive or negative; the first fixed lens group consists of three lenses, and the focal powers of the three lenses are respectively negative, positive and positive; the zoom lens group is composed of four lenses, and the focal power of the four lenses is negative, negative, positive and negative. The second fixed lens group consists of three lenses, and the focal powers of the three lenses are respectively positive, negative and positive; the focusing lens group consists of four lenses, and the focal powers are respectively positive, negative, positive and negative; the third fixed lens group consists of two lenses, and the focal powers of the two lenses are respectively positive and negative; each of the focusing lens group, the second fixed lens group and the third fixed lens group at least comprises an aspheric lens. The zoom lens can meet the use requirements of large aperture, high and low temperature confocal and 4K clear imaging on a 1 / 1.2 ''target surface and at the wave band of 436-870nm.

The invention relates to a 400G DR4 silicon optical chip which is characterized in that two input waveguides are distributed in a splayed shape, beam opening ends of the two input waveguides face outwards, one input waveguide is inclined forwards by 8 degrees + / -1 degrees, the other input waveguide is inclined backwards by 8 degrees + / -1 degrees, and each input waveguide is respectively coupled with four output waveguides. A 400G DR4 silicon optical engine is characterized in that a light emitting assembly, an aspheric lens, an optical isolator, a prism and a 400G DR4 silicon optical chip are sequentially coupled in the light propagation direction, and the center of the optical axis of the light emitting assembly is located in the middle of two input waveguides in the 400G DR4 silicon optical chip; the light emitted by the light emitting assembly in the horizontal direction is turned by 8 degrees + / -1 degrees in the forward direction or the reverse direction by the prism and then is coupled into the input waveguide which is inclined by 8 degrees + / -1 degrees in the forward direction or the reverse direction. The beneficial effects are that the laser chip in the light emitting assembly can be pasted without inclining 8 degrees + / -1 degrees, the pasting difficulty can be reduced, and the light power and the yield can be improved.

The utility model relates to a DMD welcome lamp lens with short total length, the lens is composed of a first lens, a second lens, a third lens, a fourth lens, a diaphragm, a fifth lens, a sixth lens and a seventh lens from left to right along a light incident light path, the lenses are made of glass materials, the first lens, the third lens, the fourth lens, the fifth lens, the sixth lens and the seventh lens are glass spherical lenses, the second lens is a glass aspheric lens, wherein the third lens and the fourth lens, and the fifth lens and the sixth lens form a balsaming lens group. By reasonably distributing the focal power and the surface type of each lens, the central thickness of each lens, the axial distance between the lenses and the like, the imaging performance requirement of the lens is met, the total length of the lens and the radial size of each lens are reduced, and a 33 mm lens group is formed.

The invention relates to the technical field of optical processing, and provides a monocrystalline silicon aspherical lens and a numerical control polishing process thereof, a numerical control polishing machine is used for carrying out the main steps of rough polishing, fine polishing, fine trimming and the like, process parameters are adjusted according to the characteristics of monocrystalline silicon, and therefore the monocrystalline silicon aspherical lens with the diameter smaller than 320 mm can be polished. By means of a numerical control polishing machine tool, the optimized front surface type PV can reach 0.3 mu m or below, the surface smoothness can reach 40 / 20, and the method has reference significance for monocrystalline silicon aspherical lenses with the diameter of 320 mm or above.

The utility model discloses a visible light optical system and a visible light optical lens. The visible light optical system comprises a first aspheric lens, a second aspheric lens, a super lens, a third aspheric lens, a fourth aspheric lens, a fifth aspheric lens and a sixth aspheric lens. The focal powers of the first aspheric lens, the super lens and the fifth aspheric lens are positive; the object side surface and the image side surface of the first aspheric lens are convex towards the object side; the object side surface and the image side surface of the second aspheric lens are convex towards the object side; the super lens comprises a substrate and a micro-nano structure, wherein the micro-nano structure is arranged on the object side surface and / or the image side surface of the substrate; the focal power of the fourth aspheric lens and the sixth aspheric lens is negative; the image side surface of the fifth aspheric lens protrudes towards the image side; wherein the sixth aspheric lens has the maximum focal power among the lenses with negative focal power. The visible light optical system provided by the utility model is relatively excellent in imaging quality, and the visible light optical system is relatively small in size.

An optical imaging lens adapted to limited working distance is disclosed. The optical imaging lens includes a first, a second, a third, a fourth, a fifth, a sixth lens elements and an image sensing element sequentially along an optical axis from an object-side to an image-side. The first to the sixth lens element each includes an object-side surface facing toward an object-side as well as an image-side surface facing toward an image-side. The first lens element is a wide-angle lens element. The second to the sixth lens element are a combination of aspherical lens element, molded glass lens element, and free-form surface lens element. A field of view of the optical imaging lens is greater than or equal to 100 degrees, and the optical imaging lens is a wide-angle lens.

The embodiment of the utility model discloses an ultra-wide-angle and ultra-short-focus full-width camera lens, which comprises sixteen lenses which are sequentially arranged from an object space to an image space along an optical axis, and each lens has corresponding focal power; besides, a diaphragm is arranged between the eighth lens and the ninth lens to divide the sixteen lenses into two lens groups, namely a first lens group with negative total focal power and a second lens group with positive total focal power. According to the full-frame prime lens provided by the embodiment of the utility model, by using the optical structure of the 14 glass spherical lenses and the 2 glass aspherical lenses, when the full field angle is greater than or equal to 132 degrees, the distortion is small, and the purple edge phenomenon is improved. Besides, by adding the aspherical lens, the image quality of an edge field of view is also obviously improved under an ultra-short focal length, clear imaging can be realized, and the shooting feeling of almost zero distortion is achieved.

An imaging lens includes a first lens, a prism, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens in order along an optical axis from an object side to an image side. The first lens is disposed at a light incident side of the prism, the second to sixth lenses are disposed at a light exit side of the prism, and the optical axis turns on a reflection surface of the prism. The imaging lens has a total of six lenses with diopters. The first to sixth lenses are all aspherical lenses, and the diopters are positive, positive, negative, positive, positive, and negative respectively. A ratio of a focal length of the first lens and a spacing between the prism and the second lens on the optical axis is greater than or equal to 4 and less than or equal to 60.

The invention relates to a surface type correction and processing method of an aspherical lens, which comprises the following steps of: changing a radial point location of a polishing disk participating in cutting by adopting a rotary polishing disk and lens tangent layout and through three-axis linkage of numerical control X-axis radial feeding, numerical control B-axis swinging and Z-axis approaching movement, and forming differentiation by utilizing the linear velocity gradient of the disk to remove redundant materials of the lens; and surface shape error differential correction is realized. According to the method, the polishing head does not need to be frequently replaced, over-polishing / under-polishing of traditional air bag polishing is eliminated, and the single-piece machining time is shortened; an air bag structure is omitted, the service life of consumables is prolonged, and batch fluctuation is reduced; accumulative errors are reduced through three-axis linkage, and medium-high frequency ring belt errors are restrained. The matched processing method comprises the steps of initial forming, detection, planning, correction and the like, can be quickly adapted to lenses of multiple specifications, and efficiently completes high-precision batch manufacturing of medium and large-caliber aspheric surfaces.

The invention discloses a diffractive hybrid high-image-quality lens, and the lens sequentially comprises a first lens with negative focal power from an object side to an image side along an optical axis, a second lens with negative focal power, a third lens with negative focal power, a fourth lens with negative focal power and a fifth lens with negative focal power, the object side surface of the second lens is a convex surface, and the image side surface of the second lens is a convex surface; the object side surface of the third lens is a convex surface, and the image side surface of the third lens is a concave surface; the object side surface of the fourth lens is a concave surface, and the image side surface of the fourth lens is a convex surface; the object side surface of the fifth lens is a convex surface, and the image side surface of the fifth lens is a concave surface; the lens at least comprises an aspheric lens. A diaphragm is arranged between the first lens and the second lens. The five aspherical lenses in specific shapes are adopted, through reasonable matching of the surface types and the focal power of all the lenses and reasonable arrangement of the position of the diaphragm, the system can have high image quality and low chromatic aberration, the full field angle reaches 110 degrees or above, and the distortion of the system is lower than 2%.

The invention belongs to the technical field of laser, and particularly discloses a beam shaping system and method based on prism pair orthogonality and cascade, and the system comprises a single-mode fiber, an aspherical lens, a first prism pair, a first parallel plate, a second prism pair and a second parallel plate which are sequentially arranged along the direction of an optical axis. A Gaussian beam emitted by a single-mode optical fiber is collimated by an aspherical lens to form a parallel beam, the beam is expanded or compressed in the X direction by a first prism pair, the beam is expanded in the Y direction by a second prism pair, and two inclined parallel plates are respectively used for compensating the beam offset in the X / Y direction; according to the invention, the circular Gaussian beam emitted by the single-mode fiber can be shaped, a large strip-shaped collimation light spot with an adjustable length-width ratio from 4: 1 to 20: 1 and a long axis size of 30mm can be realized, and the central positions of the input and output beams in the cross section are ensured to be unchanged.

An optical system includes, in order from an object side to an image side, a front unit having positive refractive power, an aperture stop, and a rear unit having positive refractive power. The front unit includes, in order from the object side to the image side, a first aspheric lens, a first negative lens, and a first positive lens. The rear unit includes, in order from the image side to the object side, a second aspheric lens, a second negative lens, and a second positive lens. The first aspheric lens includes an aspheric surface having an inflection point in a section including an optical axis. A predetermined condition is satisfied.

The embodiment of the invention provides a projection lens and projection equipment. Wherein the projection lens sequentially comprises a first lens group, a diaphragm and a second lens group from an imaging side to an image source side along an optical axis; the first lens group is composed of a first lens, a second lens and a third lens, the first lens is a plastic aspherical lens, and the second lens and the third lens are glass spherical lenses; the second lens group is composed of a fourth lens, a fifth lens and a sixth lens, the fourth lens and the fifth lens are glass spherical lenses, and the sixth lens is a glass aspheric lens; the diaphragm is positioned between the third lens and the fourth lens; the projection lens satisfies the following conditions: 2 < T / D < 3.5; wherein T is the total optical length of the projection lens, and D is the maximum effective clear aperture in the first lens group.

The invention discloses a visible light optical system and a visible light optical lens. The visible light optical system comprises a super lens, a first aspheric lens, a second aspheric lens, a third aspheric lens and a fourth aspheric lens. The first aspheric lens, the second aspheric lens, the third aspheric lens and the fourth aspheric lens are sequentially arranged from the object side to the image side along the optical axis. The focal power of the super lens is positive; the focal power of the first aspheric lens is positive, and the object side surface and the image side surface of the first aspheric lens both protrude towards the object side; the focal power of the second aspheric lens is negative, and the object side surface and the image side surface of the second aspheric lens both protrude towards the image side; the focal power of the third aspheric lens is positive, the object side face and the image side face of the third aspheric lens both protrude towards the image side, and the focal power of the fourth aspheric lens is negative. According to the visible light optical system, the super lens is combined with the traditional refraction lens, so that the visible light optical system has the advantages of low cost, small size and excellent imaging quality.

The invention relates to the technical field of aspherical lens machining, in particular to an edge milling device for aspherical lens machining, which comprises a clamping assembly, a first milling assembly and a second milling assembly, the milling assembly comprises a milling cutter for grinding the edge of the aspherical lens and a grinding rod for grinding the surface of the aspherical lens; the fixing assembly is used for fixing the milling cutter and the polishing rod; the protection assembly is arranged outside the clamping plates in a sleeving manner and is used for surrounding the lens between the two groups of clamping plates; the grinding device has the beneficial effects that through cooperation of the bolts and the mounting plates, the grinding rods are mounted on one sides of the clamping plates, then the lens is adsorbed to the other set of clamping plates, surface grinding of the aspheric lens is achieved, when the edge of the aspheric surface needs to be ground, the lens is clamped through the clamping assemblies, a milling cutter is driven by the connecting rods to be inserted between the two sets of clamping plates, and grinding is achieved. The edge of the aspherical lens is ground, all-directional grinding machining of the aspherical lens can be achieved without replacing equipment, and the production efficiency is improved.

The wide-angle lens comprises a first lens, a second lens, a third lens and a fourth lens which are sequentially arranged from an object plane to an image plane along an optical axis, the first lens is a glass spherical lens with negative focal power, the object side face of the first lens is a convex face, and the image side face of the first lens is a concave face. The second lens is a plastic aspheric lens with negative focal power, the object side surface of the second lens is a convex surface, and the image side surface of the second lens is a concave surface. The third lens is a plastic aspheric lens with positive focal power, the object side surface of the third lens is a concave surface, and the image side surface of the third lens is a convex surface. The fourth lens is a plastic aspheric lens with positive focal power, the object side surface of the fourth lens is a convex surface or a concave surface, and the image side surface of the fourth lens is a convex surface. The glass spherical surface and the plastic aspheric surface are matched and combined, the resolution is improved, the total axis length is smaller than 10.5 mm, the aperture F can reach 1.6, the field angle FOV can reach 183 degrees, the relative illumination can reach 50%, and the lens has the advantages of being large in aperture, ultra-large in field angle, small in size and high in illumination.

The invention discloses aspheric lens force rheological polishing equipment and a polishing method, and relates to the technical field of aspheric lenses, the aspheric lens force rheological polishing equipment comprises a polishing bottom box, an X-axis driving box is arranged at the bottom of the polishing bottom box, a polishing liquid circulating mechanism is arranged on the rear side of the polishing bottom box, and a lens clamping driving mechanism is arranged above the polishing bottom box; a flow channel embedding plate is fixedly installed at the bottom of the inner wall of the polishing bottom box, a plurality of front-back-through polishing solution restraining flow channels are formed in the top of the flow channel embedding plate, a plurality of liquid outlets penetrating through an inner cavity of the polishing bottom box are formed in the rear side of the polishing bottom box, and the multiple liquid outlets and the multiple polishing solution restraining flow channels are communicated in a front-back mode. According to the aspheric lens force rheology polishing device, through mutual cooperation of the multiple polishing solution constraint flow channels and the X-axis driving box, multi-station synchronous polishing treatment can be achieved, the number of lenses polished at a time is increased, the polishing efficiency is improved, and in addition, the invention further provides an aspheric lens force rheology polishing method.

The invention belongs to the technical field of optical thin film design and preparation, and particularly relates to a preparation method of a multilayer composite antireflection film on the surface of an optical lens. The preparation method comprises the step of sequentially performing atomic layer deposition on the surface of the optical lens to form the transition layer, the high-refractive-index layer, the low-refractive-index layer, the high-refractive-index layer and the packaging layer. According to the atomic layer deposition method, uniform coating can be achieved on the surfaces of aspherical lenses with different curvature radiuses, and five layers of oxide films are deposited through alternating pulse in an ALD pulse sequence with the structure of'substrate layer-transition layer-high refractive index layer-low refractive index layer-high refractive index layer-packaging layer '. And an excellent antireflection effect in a visible light wavelength range is realized. The atomic layer deposition is carried out at low temperature (25-150 DEG C), so that the atomic layer deposition can be directly coated on the high-molecular polymer lens, and the deformation of the base material due to high temperature is avoided; the method is especially suitable for different application scenes such as consumer electronics, personal protection and medical assistance.

The invention relates to a refractive and super hybrid visible light pick-up lens and electronic equipment, and belongs to the field of optical lenses, the refractive and super hybrid visible light pick-up lens comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens and an eighth lens which are sequentially arranged from an object plane to an image plane along an optical axis, and the other lenses are aspheric lenses. According to the invention, the large aperture and low distortion are realized through the eight-piece design, the total optical length is effectively compressed, the system is more miniaturized, lighter and thinner, and the surface type complexity of the aspherical lenses is reduced.

The invention discloses a multi-label endoscopic imaging lens for a digestive tract, and belongs to the field of biomedical microscopic endoscopic images. The endoscopic imaging lens comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens and a seventh lens. The first lens focuses laser, and the second lens is matched with the first lens to limit a light beam in an effective clear aperture of the lens; the third lens corrects chromatic aberration; a fourth lens and a fifth lens are combined to correct aberration; the sixth lens is an aspheric lens and corrects spherical aberration brought in collimation and focusing systems, and the seventh lens is matched with the sixth lens to correct chromatic aberration. The working spectral range of the microscope objective set is 488-860 nm, the effective clear aperture is smaller than 1.8 mm, the mechanical outer diameter is not larger than 2.6 mm, the numerical aperture at the object space or the tissue is 0.55, the imaging view field is 450 microns, the magnification factor is 2.14 times, and the working distance is 84 microns. And the effect of matching excitation and fluorescence spectrum of a clinically available fluorescence contrast agent is realized.

The utility model discloses a prime lens comprising a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens and an eighth lens which are arranged from an object plane to an image plane along an optical axis. The first lens is a negative focal power lens, the second lens is a negative focal power lens, the third lens is a positive focal power lens, the fourth lens is a positive focal power lens, the fifth lens is a negative focal power lens, the sixth lens is a positive focal power lens, and the seventh lens is a negative focal power lens. The eighth lens is a positive focal power lens; and the third lens or the fourth lens is a glass aspheric lens. According to the technical scheme, the number of the lenses, the focal power matching mode and the surface type matching mode are reasonably set, and the design of the fixed-focus lens which is large in aperture, small in size and capable of being confocal day and night can be achieved.

The invention relates to an ultra wide angle pick-up lens suitable for a vehicle-mounted OMS system, an optical system of the lens is composed of a first lens, a second lens, a diaphragm, a third lens, a fourth lens and a fifth lens which are sequentially arranged from left to right along a light incident light path, the first lens is a meniscus concave negative lens, the second lens is a meniscus concave negative lens, and the diaphragm is a meniscus concave negative lens. The third lens is a biconvex positive lens, the fourth lens is a biconvex positive lens, the fifth lens is a meniscus concave negative lens, the fourth lens and the fifth lens form an achromatic doublet lens, the first lens and the third lens are both made of glass materials and are spherical lenses, and the second lens, the fourth lens and the fifth lens are all plastic aspheric lenses. By adopting the glass-plastic mixed optical structure of the two glass spherical lenses and the three plastic aspheric lenses, the advantage of aberration correction of the aspheric lenses is brought into full play, high-definition imaging is met, the lens outer diameter is smaller, the optical total length is shorter, and miniaturization of the lens is ensured.

The present invention discloses a lens refractive index measuring device, comprising a diopter measuring module, a confocal reflection measuring module and a lens to be measured; the diopter measuring module is used to detect the diopter of the lens to be measured, and the confocal reflection measuring module is used to detect the confocal reflection position of the upper and lower surfaces of the lens to be measured. The lens refractive index of the lens to be measured can be obtained by the measuring device without destroying the lens, and the operation is simple and the detection is fast. Moreover, the device is applicable to the refractive index measurement of ordinary lenses, aspherical lenses, cylindrical lenses and other irregular surface lenses. The lens refractive index measuring method of the present invention is simple to operate, has fast detection and high measurement accuracy.

The embodiment of the invention provides a projection lens module and projection equipment. Wherein the projection lens module sequentially comprises a first lens group, a diaphragm and a second lens group along the optical axis direction; the first lens group comprises a first lens, a second lens, a third lens, a fourth lens and a fifth lens which are sequentially arranged along an optical axis, and the first lens and the third lens are both aspheric lenses; the second lens group comprises a doublet lens and an eighth lens which are arranged along the optical axis, and the eighth lens is an aspheric lens; the diaphragm is positioned between the fifth lens and the doublet lens; the projection lens module comprises a first lens and a second lens, the first lens is a biconcave lens, the first lens is a lens with the largest aperture in the projection lens module, the first lens meets the condition that TTL / D1 is larger than 4.3 and smaller than 5.1, TTL is the total optical length of the projection lens module, and D1 is the aperture of the first lens.