Medium-wave infrared microscopic imaging lens for optical transfer function measuring instrument

Abstract

The invention relates to a medium-wave infrared microscopic imaging lens for an optical transfer function measuring instrument, and relates to the technical field of optical testing. The medium-wave infrared microscopic imaging lens is sequentially provided with a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens along a light path propagation direction, and an aperture diaphragm is arranged on the incident plane of the sixth lens. The medium-wave infrared microscopic imaging lens for the optical transfer function measuring instrument is formed by connecting the infinity objective lens with the infinity tube lens, and the lens is suitable for medium-wave microscopic imaging and excellent in imaging performance; tolerance capacity is loose, and processing and adjustment are easy; the testing efficiency is high, the cost is low, and the practical application value is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of optical testing, and in particular to a medium-wave infrared microscopic imaging lens for an optical transmission function measuring instrument. Background Art

[0002] Application areas of medium wave infrared lenses include:

[0003] 1. Military field:

[0004] Enemy reconnaissance: At night or in low-visibility environments, medium-wave infrared lenses can produce clear images, helping military personnel conduct night reconnaissance and monitor enemy actions, such as monitoring personnel activities and equipment deployment in enemy camps.

[0005] Guided weapons: used in guided weapon systems such as missiles, which accurately guide weapons to hit the target by capturing the infrared radiation characteristics of the target.

[0006] Night vision equipment: Night vision goggles installed on military equipment such as tanks, armored vehicles, and ships allow soldiers to have good visual capabilities in dark environments, improving combat effectiveness and survivability.

[0007] Camouflage identification: It can effectively identify the real thermal radiation characteristics of the target object and see through the enemy's camouflage, such as discovering camouflaged military facilities or personnel hidden in woods or grass.

[0008] 2. Security monitoring field:

[0009] Urban security: Installed in the city’s streets, squares, important buildings and other places, it monitors public areas around the clock, promptly detects crimes such as theft, robbery, and vandalism, and ensures the safety and order of the city.

[0010] Traffic monitoring: used to monitor the driving conditions of vehicles on the road, such as identifying the vehicle's license plate, model, driving speed and other information. It can also monitor traffic accidents, road congestion and other conditions at night or in bad weather, providing a basis for traffic management and command.

[0011] Border patrol: In border areas, the border line can be monitored to detect illegal border crossings and prevent infiltration by terrorists, smugglers and other criminals.

[0012] Park monitoring: In closed areas such as industrial parks, science and technology parks, and residential communities, personnel, vehicles, and facilities within the park are monitored and managed to ensure the safety and normal operation of the park.

[0013] 3. Industrial testing:

[0014] Thermal imaging detection: Detect the heating conditions of industrial equipment, pipelines, circuits, etc., and promptly detect overheating, malfunctions and other problems to prevent equipment damage and accidents. For example, detect the heating points of power equipment so that maintenance and repair can be carried out in a timely manner.

[0015] Temperature control: In industrial production processes, it is used to monitor and control temperature to ensure the stability of the production process and product quality. For example, in high-temperature industrial production such as steel smelting and glass manufacturing, medium-wave infrared lenses can monitor the temperature in the furnace in real time.

[0016] Production process control: Monitor product quality on industrial production lines, such as detecting surface defects, welding quality, packaging integrity, etc. For example, in the electronics manufacturing industry, it can detect whether the welding of chips is good.

[0017] Material analysis: Analyze the composition and structure of the material, and determine the type, purity and other information of the material by analyzing the infrared absorption spectrum of the material.

[0018] 4. Medical diagnosis field:

[0019] Temperature detection: In public places such as hospitals, airports, and stations, human body temperature can be measured quickly and accurately to screen patients with fever, which is of great significance for the prevention and control of infectious diseases.

[0020] Thermal imaging diagnosis: helps doctors observe and diagnose patients’ tissue lesions, inflammation, blood circulation, etc. For example, by detecting the thermal distribution of breast tissue, it can assist in the diagnosis of breast diseases; by detecting the thermal radiation of joints, it can diagnose diseases such as arthritis.

[0021] 5. Firefighting and rescue field:

[0022] At the fire scene, medium-wave infrared lenses can penetrate smoke and dust, helping firefighters quickly find the source of the fire, trapped people, and understand the structure and layout of the fire scene, develop reasonable rescue plans, and improve rescue efficiency and safety.

[0023] 6. Aerospace:

[0024] It is used for thermal control system monitoring and fault detection of aerospace equipment such as aircraft and satellites, as well as observation and research of infrared radiation of celestial bodies in space environment.

[0025] In summary, as a unique optical imaging tool, medium-wave infrared imaging lenses have shown broad application prospects and huge development potential in many fields. With the continuous advancement and innovation of science and technology, it is believed that infrared optical lenses will play a more important role in the future, bringing more convenience and safety to people's lives. The imaging quality of medium-wave infrared imaging lenses in various application fields is particularly important, and the optical transfer function measuring instrument can objectively evaluate the imaging quality of medium-wave infrared imaging lenses.

[0026] The optical transfer function measuring instrument includes a target generator, a collimator, an image analyzer, etc. Among them, the medium-wave microscopic imaging lens is an important part of the image analyzer, and its designed imaging result is very important for the use of the entire optical transfer function measuring instrument. However, the existing medium-wave infrared optical lens transfer function test equipment needs to be imported from abroad, and the supporting equipment requires high funds. Summary of the invention

[0027] The present invention aims to solve the technical problems in the prior art that medium-wave infrared optical lens transmission function testing equipment needs to be imported from abroad and the supporting equipment requires high funds, and to provide a medium-wave infrared microscopic imaging lens for an optical transmission function measuring instrument which has excellent imaging performance, is easy to process and assemble, and has low cost.

[0028] In order to solve the above technical problems, the technical solutions of the present invention are as follows:

[0029] A medium-wave infrared microscopic imaging lens for an optical transmission function measuring instrument comprises: a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens arranged in sequence along the propagation direction of the optical path; an aperture stop is arranged on the incident surface of the sixth lens;

[0030] The radius of curvature of the incident surface of the first lens is -9.966±0.01mm, and the radius of curvature of the exit surface of the first lens is -10.372±0.01mm;

[0031] The radius of curvature of the incident surface of the second lens is -127.335±0.01mm, and the radius of curvature of the exit surface of the second lens is 32.398±0.01mm;

[0032] The radius of curvature of the incident surface of the third lens is 56.668±0.01mm, and the radius of curvature of the exit surface of the third lens is -78.986±0.01mm;

[0033] The radius of curvature of the incident surface of the fourth lens is -60.148±0.01mm, and the radius of curvature of the exit surface of the fourth lens is -108.897±0.01mm;

[0034] The curvature radius of the incident surface of the fifth lens is -29.687±0.01 mm, and the curvature radius of the exit surface of the fifth lens is -21.095±0.01 mm;

[0035] The radius of curvature of the incident surface of the sixth lens is 195.756±0.01 mm, and the radius of curvature of the exit surface of the sixth lens is 323.541±0.01 mm.

[0036] In the above technical solution, the refractive indexes of the materials of the first lens, the third lens, the fifth lens and the sixth lens are 3.4268194719 to 3.4225555503 respectively; the refractive indexes of the materials of the second lens and the fourth lens are 4.0292113269 to 4.0176056075 respectively.

[0037] In the above technical solution, the materials of the first lens, the third lens, the fifth lens and the sixth lens are respectively silicon; the materials of the second lens and the fourth lens are respectively germanium.

[0038] In the above technical solution, the object distance is 5.000±0.01mm;

[0039] The center distance between the first lens and the second lens is 0.03±0.01mm;

[0040] The center interval between the second lens and the third lens is 0.82±0.01mm;

[0041] The center interval between the third lens and the fourth lens is 15.34±0.01mm;

[0042] The center interval between the fourth lens and the fifth lens is 1.28±0.01mm;

[0043] The center interval between the fifth lens and the sixth lens is 10.0±1 mm;

[0044] The center distance between the sixth lens and the image plane is 196.830±1 mm.

[0045] In the above technical solution, the center thickness of the first lens is 3.0±0.01mm; the center thickness of the second lens is 2.4±0.01mm; the center thickness of the third lens is 3.5±0.01mm; the center thickness of the fourth lens is 2.0±0.01mm; the center thickness of the fifth lens is 3.0±0.01mm; and the center thickness of the sixth lens is 4.0±0.01mm.

[0046] In the above technical solution, the wavelength range is 3.7 μm to 4.8 μm.

[0047] In the above technical solution, the numerical aperture is 0.5.

[0048] In the above technical solution, the magnification is 10 times.

[0049] In the above technical solution, the object height is 1.24 mm.

[0050] The present invention has the following beneficial effects:

[0051] The medium-wave infrared microscopic imaging lens for an optical transmission function measuring instrument of the present invention is composed of an infinite objective lens connected to an infinite tube lens. The lens is suitable for medium-wave microscopic imaging and has excellent imaging performance; the tolerance capacity is loose and the processing and adjustment are easy; the testing efficiency is high and the cost is low, and the lens has practical application value.

[0052] The medium-wave infrared microscopic imaging lens for an optical transmission function measuring instrument of the present invention adopts matching of positive and negative optical powers of multiple lenses to correct spherical aberration according to aberration theory; corrects positional chromatic aberration by selecting appropriate lens materials, curvature radius and spacing; designs the imaging lens so that the imaging quality is close to the diffraction limit; and can meet the use requirements of the optical transmission function measuring instrument.

[0053] By using the medium-wave infrared microscopic imaging lens for an optical transfer function measuring instrument of the present invention, the self-developed optical transfer function measuring instrument can reach the accuracy of the imported f4000 type equipment, and can save a lot of costs for purchasing imported equipment for domestic purchasing units. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0055] Figure 1 The optical design diagram of the medium-wave infrared microscopic imaging lens used in the optical transmission function measuring instrument of the present invention is shown in FIG.

[0056] Figure 2 The figure is a schematic diagram of the diffuse spot of the medium-wave infrared microscopic imaging lens used for the optical transmission function measuring instrument of the present invention.

[0057] Figure 3 The figure is a schematic diagram of the field curvature and distortion of the medium-wave infrared microscopic imaging lens used in the optical transmission function measuring instrument of the present invention.

[0058] Figure 4 It is a schematic diagram of an optical transfer function curve of a medium-wave infrared microscopic imaging lens used in an optical transfer function measuring instrument of the present invention. DETAILED DESCRIPTION

[0059] The medium-wave infrared microscopic imaging lens for an optical transmission function measuring instrument of the present invention comprises: a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens which are sequentially arranged along the propagation direction of the optical path; the first lens is a concave-convex positive lens, the second lens is a concave-convex negative lens, the third lens is a convex-convex positive lens, the fourth lens is a concave-convex negative lens, the fifth lens is a concave-convex positive lens, and the sixth lens is a convex-concave positive lens. The first five lenses together form the objective lens of the medium-wave microscopic imaging lens, and the sixth lens is a rear tube lens. There is parallel light between the objective lens and the tube lens. When in use, the tube lens and the imaging device at the rear image plane can be assembled and adjusted, and then the front objective lens is installed.

[0060] The aperture diaphragm is placed on the incident surface of the sixth lens. The aperture diaphragm determines the entrance pupil diameter and numerical aperture of the system. The size of the image formed by the aperture diaphragm in object space is the entrance pupil diameter, and the size of the image formed by the image aperture is the exit pupil diameter. The aperture diaphragm is placed on the last lens (the sixth lens) counting from left to right, so that the diameter of the light beam entering the imaging device can be determined by the rear end tube lens.

[0061] The object to be measured is located 5.000mm in front of the medium-wave infrared microscopic imaging lens. The medium-wave infrared imaging device is located on the image plane. The numerical aperture of the medium-wave infrared microscopic imaging lens is 0.5 and the magnification is 10 times.

[0062] The above-mentioned lens is a medium-wave infrared achromatic optical imaging lens with a wavelength band of 3.7μm to 4.8μm. The medium-wave spectral signal is received by a medium-wave infrared imaging device, and the optical transfer function of the lens under test is obtained by analyzing and calculating the optical signal.

[0063] The medium-wave infrared microscopic imaging lens for the optical transmission function measuring instrument of the present invention adopts two materials with different dispersion coefficients, the refractive index of the first material is 3.4268194719-3.4225555503, and the refractive index of the second material is 4.0292113269-4.0176056075.

[0064] The first material is silicon, the second material is germanium, the first lens, the third lens, the fifth lens, and the sixth lens all use the first material, and the second lens and the fourth lens all use the second material.

[0065] From left to right along the propagation direction of the light path, the two sides of the first lens are the first lens incident surface and the first lens exit surface; the two sides of the second lens are the second lens incident surface and the second lens exit surface; the two sides of the third lens are the third lens incident surface and the third lens exit surface; the two sides of the fourth lens are the fourth lens incident surface and the fourth lens exit surface; the two sides of the fifth lens are the fifth lens incident surface and the fifth lens exit surface; the two sides of the sixth lens are the sixth lens incident surface and the sixth lens exit surface.

[0066] The numerical aperture of the medium-wave infrared microscopic imaging lens for the optical transmission function measuring instrument of the present invention is 0.5, and the object height is 1.24 mm. It belongs to a small field of view and large aperture optical system, and the field curvature, astigmatism, distortion and magnification chromatic aberration are relatively small, and the spherical aberration and position chromatic aberration related to the aperture are mainly considered.

[0067] The medium-wave infrared microscopic imaging lens for an optical transmission function measuring instrument of the present invention adopts the matching of positive and negative optical powers of multiple lenses to correct spherical aberration; and selects appropriate lens materials, curvature radius and spacing to correct position chromatic aberration.

[0068] In order to further ensure the imaging quality, the medium-wave infrared microscopic imaging lens for the optical transmission function measuring instrument of the present invention has a first lens incident surface with a radius of curvature of -9.966±0.01mm, and a first lens exit surface with a radius of curvature of -10.372±0.01mm; a second lens incident surface with a radius of curvature of -127.335±0.01mm, and a second lens exit surface with a radius of curvature of 32.398±0.01mm; a third lens incident surface with a radius of curvature of 56.668±0.01mm, and a third lens exit surface with a radius of curvature of The radius of curvature of the incident surface of the fourth lens is -60.148±0.01mm, and the radius of curvature of the exit surface of the fourth lens is -108.897±0.01mm; the radius of curvature of the incident surface of the fifth lens is -29.687±0.01mm, and the radius of curvature of the exit surface of the fifth lens is -21.095±0.01mm; the radius of curvature of the incident surface of the sixth lens is 195.756±0.01mm, and the radius of curvature of the exit surface of the sixth lens is 323.541±0.01mm.

[0069] The meaning of the positive and negative values ​​of the radius of curvature is as follows: when the light propagates from left to right, if the center of curvature of the radius of curvature is to the right of the surface vertex, the radius of curvature is positive; if the center of curvature of the radius of curvature is to the left of the surface vertex, the radius of curvature is negative.

[0070] In order to better ensure the imaging quality, the medium-wave infrared microscopic imaging lens for the optical transmission function measuring instrument of the present invention has an object distance of 5.000±0.01mm; the center interval between the first lens and the second lens is 0.03±0.01mm; the center interval between the second lens and the third lens is 0.82±0.01mm; the center interval between the third lens and the fourth lens is 15.34±0.01mm; the center interval between the fourth lens and the fifth lens is 1.28±0.01mm; the center interval between the fifth lens and the sixth lens is 10.0±1mm; and the center interval between the sixth lens and the image plane is 196.830±1mm.

[0071] The center thickness of the first lens is 3.0±0.01mm; the center thickness of the second lens is 2.4±0.01mm; the center thickness of the third lens is 3.5±0.01mm; the center thickness of the fourth lens is 2.0±0.01mm; the center thickness of the fifth lens is 3.0±0.01mm; and the center thickness of the sixth lens is 4.0±0.01mm.

[0072] The medium-wave infrared microscopic imaging lens used for the optical transmission function measuring instrument of the present invention has a wavelength range of 3.7 μm to 4.8 μm, a numerical aperture of 0.5, a magnification of 10 times, and an object height of 1.24 mm.

[0073] The present invention is described in detail below with reference to the accompanying drawings.

[0074] like Figure 1 As shown, the medium-wave infrared microscopic imaging lens for the optical transmission function measuring instrument of the present invention is sequentially provided with: a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens from left to right along the propagation direction of the optical path, and the aperture stop is placed on the incident surface of the sixth lens. The object to be measured is placed at 5.000mm on the left side of the medium-wave microscopic imaging lens, and the image plane imaging device is placed at 196.830mm on the right side of the last surface on the right side of the medium-wave microscopic imaging lens.

[0075] From left to right along the propagation direction of the light path, the two surfaces of the first lens are the first lens incident surface S1 and the first lens exit surface S2, the two surfaces of the second lens are the second lens incident surface S3 and the second lens exit surface S4, the two surfaces of the third lens are the third lens incident surface S5 and the third lens exit surface S6, the two surfaces of the fourth lens are the fourth lens incident surface S7 and the fourth lens exit surface S8, the two surfaces of the fifth lens are the fifth lens incident surface S9 and the fifth lens exit surface S10, and the two surfaces of the sixth lens are the sixth lens incident surface S11 and the sixth lens exit surface S12. The radius of curvature of the first lens incident surface S1 is -9.966 mm, and the radius of curvature of the first lens exit surface S2 is -10.372 mm; the radius of curvature of the second lens incident surface S3 is 127.335 mm, and the radius of curvature of the second lens exit surface S4 is 32.398 mm; the radius of curvature of the third lens incident surface S5 is 56.668 mm, and the radius of curvature of the third lens exit surface S6 is -78.986 mm; The radius of curvature of the lens incident surface S7 is -60.148mm, and the radius of curvature of the fourth lens exit surface S8 is -108.897mm; the radius of curvature of the fifth lens incident surface S9 is -29.687mm, and the radius of curvature of the fifth lens exit surface S10 is -21.095mm; the radius of curvature of the sixth lens incident surface S11 is 195.756mm, and the radius of curvature of the sixth lens exit surface S12 is 323.541mm.

[0076] The meanings of positive and negative values ​​of the radius of curvature are as follows: Figure 1 As shown, the light propagates from left to right. If the center of curvature of the radius of curvature is to the right of the surface vertex, the radius of curvature is positive. If the center of curvature of the radius of curvature is to the left of the surface vertex, the radius of curvature is negative.

[0077] The object distance of the medium-wave infrared microscopic imaging lens for the optical transmission function measuring instrument of the present invention is 5.000mm; the center interval between the first lens and the second lens is 0.03mm; the center interval between the second lens and the third lens is 0.82mm; the center interval between the third lens and the fourth lens is 15.340mm; the center interval between the fourth lens and the fifth lens is 1.28mm; the center interval between the fifth lens and the sixth lens is 10.00mm; and the center interval between the sixth lens and the image plane is 196.830mm.

[0078] The center thickness of the first lens is 3.0 mm; the center thickness of the second lens is 2.4 mm; the center thickness of the third lens is 3.5 mm; the center thickness of the fourth lens is 2.0 mm; the center thickness of the fifth lens is 3.0 mm; and the center thickness of the sixth lens is 4.0 mm.

[0079] The first lens, the third lens, the fifth lens and the sixth lens are all made of silicon, and the second lens and the fourth lens are all made of germanium.

[0080] Table 1 Optical element parameters of the medium-wave infrared microscopic imaging lens for the optical transmission function measuring instrument of the present invention

[0081]

[0082] The optical parameters of the medium-wave infrared microscopic imaging lens for the optical transmission function measuring instrument of the present invention are as follows:

[0083] Magnification: 10 times;

[0084] Numerical aperture: 0.5;

[0085] Wavelength: 3.7μm~4.8μm;

[0086] Object line field of view: 1.24mm;

[0087] Object distance: 5.000mm;

[0088] Rear working distance: 196.83mm;

[0089] Lens length: 45.37mm;

[0090] Object to image distance: 247.2mm.

[0091] The medium-wave infrared microscopic imaging lens for an optical transmission signal measuring instrument of the present invention is a medium-wave microscopic imaging lens with a wavelength range from 3.7 μm to 4.8 μm, receives a spectrum signal in the medium-wave infrared band, analyzes and calculates the medium-wave information of the imaging, and is applied to the optical transmission signal measuring instrument to test the imaging performance of infrared lenses in various fields such as military, security, industrial detection, medical diagnosis, firefighting and rescue, and aerospace.

[0092] Depend on Figure 2 It can be seen from the dispersion pattern shown that the dispersion spots in each field of view of the lens of the present invention are well corrected, the dispersion spot radius of the central field of view is within the Airy disk, the RMS value of the on-axis dispersion spot radius is 15.406 μm, and the RMS value of the dispersion spot radius at the maximum off-axis field of view is 28.068 μm.

[0093] Depend on Figure 3 It can be seen from the field curvature and distortion diagrams that the maximum field curvature of the lens of the present invention is 0.0334 mm, and the maximum distortion is 0.0712%.

[0094] Depend on Figure 4 It can be seen from the optical transfer function curve shown that the optical transfer function of each field of view of the lens of the present invention is close to the diffraction limit.

[0095] In summary, the quality of the medium-wave infrared microscopic imaging lens for an optical transmission function measuring instrument of the present invention can meet the use requirements of the optical transmission function measuring instrument.

[0096] The medium-wave infrared microscopic imaging lens for an optical transmission function measuring instrument of the present invention is composed of an infinite objective lens connected to an infinite tube lens. The lens is suitable for medium-wave microscopic imaging and has excellent imaging performance; the tolerance capacity is loose and the processing and adjustment are easy; the testing efficiency is high and the cost is low, and the lens has practical application value.

[0097] The medium-wave infrared microscopic imaging lens for an optical transmission function measuring instrument of the present invention adopts matching of positive and negative optical powers of multiple lenses to correct spherical aberration according to aberration theory; corrects positional chromatic aberration by selecting appropriate lens materials, curvature radius and spacing; designs the imaging lens so that the imaging quality is close to the diffraction limit; and can meet the use requirements of the optical transmission function measuring instrument.

[0098] By using the medium-wave infrared microscopic imaging lens for an optical transfer function measuring instrument of the present invention, the self-developed optical transfer function measuring instrument can reach the accuracy of the imported f4000 type equipment, and can save a lot of costs for purchasing imported equipment for domestic purchasing units.

[0099] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention.

Claims

1. A medium-wave infrared microscopic imaging lens for an optical transmission function measuring instrument, characterized in that: The first lens, the second lens, the third lens, the fourth lens, the fifth lens and the sixth lens are sequentially arranged along the propagation direction of the optical path; an aperture stop is arranged on the incident surface of the sixth lens; The radius of curvature of the incident surface of the first lens is -9.966±0.01mm, and the radius of curvature of the exit surface of the first lens is -10.372±0.01mm; The radius of curvature of the incident surface of the second lens is -127.335±0.01mm, and the radius of curvature of the exit surface of the second lens is 32.398±0.01mm; The radius of curvature of the incident surface of the third lens is 56.668±0.01mm, and the radius of curvature of the exit surface of the third lens is -78.986±0.01mm; The radius of curvature of the incident surface of the fourth lens is -60.148±0.01mm, and the radius of curvature of the exit surface of the fourth lens is -108.897±0.01mm; The curvature radius of the incident surface of the fifth lens is -29.687±0.01 mm, and the curvature radius of the exit surface of the fifth lens is -21.095±0.01 mm; The radius of curvature of the incident surface of the sixth lens is 195.756±0.01 mm, and the radius of curvature of the exit surface of the sixth lens is 323.541±0.01 mm.

2. The medium-wave infrared microscopic imaging lens for an optical transmission function measuring instrument according to claim 1, characterized in that: The refractive indexes of the materials of the first lens, the third lens, the fifth lens and the sixth lens are 3.4268194719 to 3.4225555503 respectively; The refractive indexes of the materials of the second lens and the fourth lens are 4.0292113269 to 4.0176056075 respectively.

3. The medium-wave infrared microscopic imaging lens for an optical transmission function measuring instrument according to claim 2, characterized in that: The first lens, the third lens, the fifth lens and the sixth lens are made of silicon respectively; the second lens and the fourth lens are made of germanium respectively.

4. The medium-wave infrared microscopic imaging lens for an optical transmission function measuring instrument according to claim 1, characterized in that: Object distance: 5.000±0.01mm; The center distance between the first lens and the second lens is 0.03±0.01mm; The center interval between the second lens and the third lens is 0.82±0.01mm; The center interval between the third lens and the fourth lens is 15.34±0.01mm; The center interval between the fourth lens and the fifth lens is 1.28±0.01mm; The center interval between the fifth lens and the sixth lens is 10.0±1 mm; The center distance between the sixth lens and the image plane is 196.830±1 mm.

5. The medium-wave infrared microscopic imaging lens for an optical transmission function measuring instrument according to claim 1, characterized in that: The center thickness of the first lens is 3.0±0.01mm; the center thickness of the second lens is 2.4±0.01mm; the center thickness of the third lens is 3.5±0.01mm; the center thickness of the fourth lens is 2.0±0.01mm; the center thickness of the fifth lens is 3.0±0.01mm; and the center thickness of the sixth lens is 4.0±0.01mm.

6. The medium-wave infrared microscopic imaging lens for an optical transmission function measuring instrument according to any one of claims 1 to 5, characterized in that: The wavelength range is 3.7μm~4.8μm.

7. The medium-wave infrared microscopic imaging lens for an optical transmission function measuring instrument according to any one of claims 1 to 5, characterized in that: The numerical aperture is 0.

5.

8. The medium-wave infrared microscopic imaging lens for an optical transmission function measuring instrument according to any one of claims 1 to 5, characterized in that: The magnification is 10x.

9. The medium-wave infrared microscopic imaging lens for an optical transmission function measuring instrument according to any one of claims 1 to 5, characterized in that: The object height is 1.24mm.

Images