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

Abstract

The invention relates to a short-wave infrared microscopic imaging lens for an optical transfer function measuring instrument, and relates to the technical field of optical testing. The short-wave infrared microscopic imaging lens comprises a first positive lens, a first negative lens, a second positive lens, a second negative lens, a third positive lens and a third negative lens which are sequentially arranged along a light path propagation direction, an aperture diaphragm is arranged on the incident plane of the first positive lens; the first positive lens and the first negative lens are glued through a first lens gluing surface to form a first lens, the second positive lens and the second negative lens are glued through a second lens gluing surface to form a second lens, and the third positive lens and the third negative lens are glued through a third lens gluing surface to form a third lens. According to the short-wave infrared microscopic imaging lens for the optical transfer function measuring instrument, the imaging performance of short-wave microscopic imaging is excellent; tolerance capacity is loose, and processing and adjustment are easy; the method is high in testing efficiency, low in cost and suitable for practical application.

Description

Technical Field

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

[0002] Application areas of short-wave infrared lenses include:

[0003] 1. Infrared thermal imaging and detection

[0004] It can detect and measure the thermal radiation of objects and the imaging quality of optical lenses in the same standard band. It can detect the heating conditions of industrial equipment, pipelines, circuits, etc., and promptly discover problems such as overheating and failure. This feature makes short-wave infrared lenses widely used in many fields.

[0005] 2. Military field:

[0006] It is often used in fire control systems, missile guidance, drone reconnaissance and monitoring, etc. The all-weather adaptability and high recognition of short-wave infrared lenses enable it to provide more accurate and reliable intelligence information in military operations.

[0007] 3. Aerospace:

[0008] 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.

[0009] In summary, short-wave infrared lenses have a wide range of applications and prospects. They will play a more important role in the future, contribute more to maintaining national security, social stability and economic development, and bring more convenience and safety to people's lives. The imaging quality of short-wave imaging lenses in application fields is particularly important, and the optical transfer function measuring instrument can objectively evaluate the imaging quality of short-wave imaging lenses.

[0010] The optical transfer function measuring instrument includes a target generator, a collimator, an image analyzer, etc. Among them, the short-wavelength microscopic imaging lens is an important part of the image analyzer, and its imaging result is very important for the use of the entire optical transfer function measuring instrument. However, the existing short-wavelength infrared optical lens transfer function test equipment needs to be imported from abroad, and the cost of supporting equipment is too high. Summary of the invention

[0011] The present invention aims to solve the technical problems in the prior art that short-wave infrared optical lens transmission function test equipment needs to be imported from abroad and the cost of supporting equipment is too high, and to provide a short-wave infrared microscopic imaging lens for an optical transmission function measuring instrument with loose installation tolerance and low processing cost.

[0012] In order to solve the above technical problems, the technical solutions of the present invention are as follows:

[0013] A short-wave infrared microscopic imaging lens for optical transmission function measuring instrument,

[0014] It comprises: a first positive lens, a first negative lens, a second positive lens, a second negative lens, a third positive lens and a third negative lens, which are arranged in sequence along the propagation direction of the light path;

[0015] An aperture stop is provided on the incident surface of the first positive lens;

[0016] The first positive lens and the first negative lens are glued together through the first lens glueing surface to form a first lens, the second positive lens and the second negative lens are glued together through the second lens glueing surface to form a second lens, and the third positive lens and the third negative lens are glued together through the third lens glueing surface to form a third lens;

[0017] The incident surface of the first lens is a plane, and the radius of curvature of the cemented surface of the first lens is -3.874±0.01mm.

[0018] The curvature radius of the first lens exit surface is -7.000±0.01mm;

[0019] The radius of curvature of the incident surface of the second lens is 18.266±0.01mm, the radius of curvature of the cemented surface of the second lens is -9.790±0.01mm, and the radius of curvature of the exit surface of the second lens is 8.311±0.01mm;

[0020] The radius of curvature of the incident surface of the third lens is 31.829±0.01mm, the radius of curvature of the cemented surface of the third lens is -5.840±0.01mm, and the radius of curvature of the exit surface of the third lens is -11.219±0.01mm.

[0021] In the above technical solution, the refractive index of the material of the first positive lens and the third positive lens is 1.5768641658 to 1.5834787384 respectively;

[0022] The material refractive index of the first negative lens is 1.8757903108 to 1.8986664940;

[0023] The material refractive index of the second positive lens is 1.8464009103~1.8602433167;

[0024] The refractive index of the material of the second negative lens is 1.4989244047 to 1.5075480449;

[0025] The refractive indexes of the materials of the third negative lens are 1.7981642934 to 1.8115564591 respectively.

[0026] In the above technical solution, the materials of the first positive lens, the second negative lens and the third positive lens are respectively crown glass; the material of the first negative lens is flint glass; the material of the second positive lens and the third negative lens are respectively lanthanide optical glass.

[0027] In the above technical solution, the object distance is 5.912±0.01mm; the center distance between the first lens and the second lens is 0.200±0.01mm; the center distance between the second lens and the third lens is

[0028] 1.799±0.01mm; the center distance between the third lens and the image plane is 97.278±1mm.

[0029] In the above technical solution, the center thickness of the first positive lens is 2.430±0.01mm, and the center thickness of the first negative lens is 0.6±0.01mm; the center thickness of the second positive lens is 3.930±0.01mm, and the center thickness of the second negative lens is 4.000±0.01mm; the center thickness of the third positive lens is 2.850±0.01mm, and the center thickness of the third negative lens is 1.000±0.01mm.

[0030] In the above technical solution, the wavelength range is 1.0 μm to 1.7 μm.

[0031] In the above technical solution, the numerical aperture is 0.5.

[0032] In the above technical solution, the magnification is 10 times.

[0033] In the above technical solution, the object height is 0.6 mm.

[0034] The present invention has the following beneficial effects:

[0035] The short-wave infrared microscopic imaging lens for the optical transmission function measuring instrument of the present invention has excellent imaging performance of short-wave microscopic imaging, loose tolerance capacity, easy processing and adjustment, high testing efficiency, low cost, and is suitable for practical application.

[0036] The short-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; selects suitable lens materials, curvature radius and spacing to correct position chromatic aberration; adopts double bonding to control system distance, and designs the imaging lens to have imaging quality close to the diffraction limit; and can meet the use requirements of the optical transmission function measuring instrument.

[0037] By using the short-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

[0038] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0039] Figure 1 The optical design diagram of the short-wave infrared microscopic imaging lens used in the optical transmission function measuring instrument of the present invention is shown in FIG.

[0040] Figure 2 The figure is a schematic diagram of the diffuse spot of the short-wave infrared microscopic imaging lens used for the optical transfer function measuring instrument of the present invention.

[0041] Figure 3 The diagram is a schematic diagram of field curvature and distortion of a short-wave infrared microscopic imaging lens for an optical transmission function measuring instrument according to the present invention.

[0042] Figure 4 It is a schematic diagram of an optical transfer function curve of a short-wave infrared microscopic imaging lens used in an optical transfer function measuring instrument of the present invention. DETAILED DESCRIPTION

[0043] The short-wave infrared microscopic imaging lens for an optical transmission function measuring instrument of the present invention comprises: a first lens, a second lens, and a third lens arranged in sequence along the propagation direction of the optical path, and an aperture stop is arranged on the incident surface (first surface) of the first lens; wherein the first lens, the second lens, and the third lens are all formed by double-cemented lenses, the first lens is formed by the first positive lens and the first negative lens being glued together, the second lens is formed by the second positive lens and the second negative lens being glued together, and the third lens is formed by the third positive lens and the third negative lens being glued together. The above double-cemented lens is formed by two lenses being glued together.

[0044] The aperture diaphragm is set on the incident surface of the first lens. The aperture diaphragm can determine the entrance pupil diameter and numerical aperture of the system. The size of the image formed by the aperture diaphragm in the 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 first lens. In this way, the diameter of the beam entering the system can be determined by the front-end microscope objective.

[0045] The object to be measured is located 5.912 mm in front of the short-wave infrared microscopic imaging lens. The short-wave infrared imaging device is located on the image plane. The numerical aperture of the short-wave infrared microscopic imaging lens is 0.5 and the magnification is 10 times.

[0046] The lens of the present invention is a short-wave infrared achromatic optical imaging lens with a wavelength band of 1.0 μm to 1.7 μm. The short-wave infrared imaging device receives short-wave spectrum signals, and the optical transfer function of the lens under test is obtained by analyzing and calculating the optical signals.

[0047] The short-wave infrared microscopic imaging lens for the optical transmission function measuring instrument of the present invention adopts five materials with different dispersion coefficients:

[0048] The refractive index of the first material is 1.5768641658~1.5834787384;

[0049] The refractive index of the second material is 1.8757903108~1.8986664940;

[0050] The refractive index of the third material is 1.8464009103~1.8602433167;

[0051] The refractive index of the fourth material is 1.4989244047~1.5075480449;

[0052] The refractive index of the fifth material is 1.7981642934~1.8115564591.

[0053] Specifically, the first material may be crown glass, the second material may be flint glass, the third material may be lanthanum glass, the fourth material may be crown glass, and the fifth material may be lanthanum glass.

[0054] Specifically, the first positive lens, the second negative lens and the third positive lens are made of crown glass respectively; the first negative lens is made of flint glass; the second positive lens and the third negative lens are made of lanthanide glass respectively.

[0055] The short-wave infrared microscopic imaging lens for an optical transmission function measuring instrument of the present invention has two sides of a first lens, from left to right, along the propagation direction of an optical path, respectively comprising a first lens incident surface (first lens object side surface) and a first lens exit surface (first lens image side surface), with a first lens cementing surface provided between the two sides; two sides of a second lens are respectively a second lens incident surface (second lens object side surface) and a second lens exit surface (second lens image side surface), with a second lens cementing surface provided between the two sides; two sides of a third lens are respectively a third lens incident surface (third lens object side surface) and a third lens exit surface (third lens image side surface), with a third lens cementing surface provided between the two sides.

[0056] The short-wave infrared microscopic imaging lens for optical transmission function measuring instrument of the present invention has a numerical aperture of 0.5 and an object height of 0.6 mm, and belongs to a small field of view and large aperture optical system, and has relatively small field curvature, astigmatism, distortion and magnification chromatic aberration, and mainly considers spherical aberration and position chromatic aberration related to the aperture. The short-wave infrared microscopic imaging lens for 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; selects appropriate lens materials, curvature radius and spacing to correct position chromatic aberration; selects cemented lens to shorten the length of the system.

[0057] In order to further ensure the imaging quality, in the short-wave infrared microscopic imaging lens for the optical transmission function measuring instrument of the present invention, the incident surface of the first lens is a plane, the curvature radius of the first lens bonding surface is -3.874±0.01mm, and the curvature radius of the first lens exit surface is -7.000±0.01mm; the curvature radius of the second lens incident surface is 18.266±0.01mm, the curvature radius of the second lens bonding surface is -9.790±0.01mm, and the curvature radius of the second lens exit surface is 8.311±0.01mm; the curvature radius of the third lens incident surface is 31.829±0.01mm, the curvature radius of the third lens bonding surface is -5.840±0.01mm, and the curvature radius of the third lens exit surface is -11.219±0.01mm;

[0058] 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.

[0059] In order to better ensure the imaging quality, the object distance of the short-wave infrared microscopic imaging lens for the optical transmission function measuring instrument of the present invention is 5.912±0.01mm; the center distance between the first lens and the second lens is 0.200±0.01mm; the center distance between the second lens and the third lens is 1.799±0.01mm; and the center distance between the third lens and the image plane is 97.278±1mm.

[0060] Since all three lens groups are double-cemented lenses, the center thickness of the first positive lens of the first lens is 2.430±0.01mm, and the center thickness of the first negative lens of the first lens is 0.6±0.01mm; the center thickness of the second positive lens of the second lens is 3.930±0.01mm, and the center thickness of the second negative lens of the second lens is 4.000±0.01mm; the center thickness of the third positive lens of the third lens is 2.850±0.01mm, and the center thickness of the third negative lens of the third lens is 1.000±0.01mm.

[0061] The above-mentioned short-wave infrared microscopic imaging lens has a wavelength range of 1.0 μm to 1.7 μm, a numerical aperture of 0.5, a magnification of 10 times, and an object height of 0.6 mm.

[0062] The present invention is described in detail below with reference to the accompanying drawings.

[0063] like Figure 1As shown, the short-wave infrared microscopic imaging lens for the optical transmission function measuring instrument of the present invention is provided with, from left to right, a first lens, a second lens, and a third lens in sequence, and the aperture stop is placed on the incident surface of the first lens. The object to be measured is placed at 5.912 mm on the left side of the short-wave microscopic imaging lens, and the image plane imaging device is placed at 97.278 mm on the right side of the last surface on the right side of the short-wave microscopic imaging lens.

[0064] From left to right along the propagation direction of the light path, the three surfaces of the first lens are the first lens incident surface S1, the first lens bonding surface S2 and the first lens exit surface S3; the three surfaces of the second lens are the second lens incident surface S4, the second lens bonding surface S5 and the second lens exit surface S6; the three surfaces of the third lens are the third lens incident surface S7, the third lens bonding surface S8 and the third lens exit surface S9. Among them, the first lens incident surface S1 is a plane, and the curvature radius of the first lens bonding surface S2 is -3.874mm; the curvature radius of the first lens exit surface S3 is -7.000mm, and the curvature radius of the second lens incident surface S4 is 18.266mm; the curvature radius of the second lens bonding surface S5 is -9.790mm, and the curvature radius of the second lens exit surface S6 is 8.311mm; the curvature radius of the third lens incident surface S7 is 31.829mm, and the curvature radius of the third lens bonding surface S8 is -5.840mm; the curvature radius of the third lens exit surface S9 is -11.219mm.

[0065] 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.

[0066] The object distance of the short-wave infrared microscopic imaging lens for the optical transmission function measuring instrument of the present invention is 5.912mm; the center interval between the first lens and the second lens is 0.2mm; the center interval between the second lens and the third lens is 1.799mm; and the center interval between the third lens and the image plane is 97.278mm.

[0067] The center thickness of the first positive lens of the first lens is 2.430 mm, and the center thickness of the first negative lens of the first lens is 0.6 mm; the center thickness of the second positive lens of the second lens is 3.930 mm, and the center thickness of the second negative lens of the second lens is 4.000 mm; the center thickness of the third positive lens of the third lens is 2.850 mm, and the center thickness of the third negative lens of the third lens is 1.000 mm.

[0068] The first positive lens and the third positive lens are made of crown glass made of H-ZPK5, the first negative lens is made of flint glass made of H-ZF88, the second positive lens is made of lanthanum glass made of H-ZLAF68N, the second negative lens is made of crown glass made of H-K9L, and the third negative lens is made of lanthanum glass made of H-ZLAF53B.

[0069] Table 1 Optical element parameter table of the short-wave infrared microscopic imaging lens for the optical transmission function measuring instrument of the present invention

[0070]

[0071]

[0072] The optical parameters of the short-wave infrared microscopic imaging lens for the optical transmission function measuring instrument of the present invention are as follows:

[0073] Magnification: 10 times; numerical aperture: 0.5;

[0074] Wavelength: 1.0μm~1.7μm;

[0075] Object line field of view: 0.6mm;

[0076] Object distance: 5.912mm;

[0077] Rear working distance: 97.278mm;

[0078] Lens length 16.8mm;

[0079] Object to image distance: 120.0mm.

[0080] The short-wave infrared microscopic imaging lens for an optical transmission function measuring instrument of the present invention is a short-wave microscopic imaging lens with a wavelength range from 1.0 μm to 1.7 μm. It receives a short-wave infrared wavelength spectrum signal, analyzes and calculates the short-wave information of the imaging, and applies it to the optical transmission function measuring instrument to test the imaging performance of short-wave infrared lenses in various fields such as military, aerospace, and industrial fields.

[0081] Depend on Figure 2 It can be seen from the dispersion pattern 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 10.000 μm, and the RMS value of the dispersion spot radius at the maximum off-axis field of view is 16.5 μm.

[0082] 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 0.3139 mm, and the maximum distortion is 0.0001%.

[0083] Depend on Figure 4It 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.

[0084] In summary, the quality of the short-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.

[0085] The short-wave infrared microscopic imaging lens for the optical transmission function measuring instrument of the present invention has excellent imaging performance of short-wave microscopic imaging, loose tolerance capacity, easy processing and adjustment, high testing efficiency, low cost, and is suitable for practical application.

[0086] The short-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; selects suitable lens materials, curvature radius and spacing to correct position chromatic aberration; adopts double bonding to control system distance, and designs the imaging lens to have imaging quality close to the diffraction limit; and can meet the use requirements of the optical transmission function measuring instrument.

[0087] By using the short-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.

[0088] 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 short-wave infrared microscopic imaging lens for an optical transmission function measuring instrument, characterized in that: It comprises: a first positive lens, a first negative lens, a second positive lens, a second negative lens, a third positive lens and a third negative lens, which are arranged in sequence along the propagation direction of the light path; An aperture stop is provided on the incident surface of the first positive lens; The first positive lens and the first negative lens are glued together through the first lens glueing surface to form a first lens, the second positive lens and the second negative lens are glued together through the second lens glueing surface to form a second lens, and the third positive lens and the third negative lens are glued together through the third lens glueing surface to form a third lens; The incident surface of the first lens is a plane, and the radius of curvature of the cemented surface of the first lens is -3.874±0.01mm. The curvature radius of the first lens exit surface is -7.000±0.01mm; The radius of curvature of the incident surface of the second lens is 18.266±0.01mm, the radius of curvature of the cemented surface of the second lens is -9.790±0.01mm, and the radius of curvature of the exit surface of the second lens is 8.311±0.01mm; The radius of curvature of the incident surface of the third lens is 31.829±0.01mm, the radius of curvature of the cemented surface of the third lens is -5.840±0.01mm, and the radius of curvature of the exit surface of the third lens is -11.219±0.01mm.

2. The short-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 positive lens and the third positive lens are 1.5768641658 to 1.5834787384 respectively; The material refractive index of the first negative lens is 1.8757903108 to 1.8986664940; The material refractive index of the second positive lens is 1.8464009103~1.8602433167; The refractive index of the material of the second negative lens is 1.4989244047 to 1.5075480449; The refractive indexes of the materials of the third negative lens are 1.7981642934 to 1.8115564591 respectively.

3. The short-wave infrared microscopic imaging lens for an optical transmission function measuring instrument according to claim 2, characterized in that: The materials of the first positive lens, the second negative lens and the third positive lens are respectively crown glass; The material of the first negative lens is flint glass; The second positive lens and the third negative lens are made of lanthanum glass.

4. The short-wave infrared microscopic imaging lens for an optical transmission function measuring instrument according to claim 1, characterized in that: The object distance is 5.912±0.01mm; the center distance between the first lens and the second lens is 0.200±0.01mm; the center distance between the second lens and the third lens is 1.799±0.01mm; and the center distance between the third lens and the image plane is 97.278±1mm.

5. The short-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 positive lens is 2.430±0.01mm, and the center thickness of the first negative lens is 0.6±0.01mm; the center thickness of the second positive lens is 3.930±0.01mm, and the center thickness of the second negative lens is 4.000±0.01mm; the center thickness of the third positive lens is 2.850±0.01mm, and the center thickness of the third negative lens is 1.000±0.01mm.

6. The short-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 1.0μm~1.7μm.

7. The short-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 short-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 short-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 0.6mm.

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