A short-wave infrared microscope imaging lens for optical transmission function measuring instrument

Abstract

The present invention relates to a short-wave infrared microscopic imaging lens for an optical transmission function measuring instrument, and relates to the field of optical testing technology. The short-wave infrared microscopic imaging lens includes: 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 bonded together through a first lens bonding surface to form a first lens, the second positive lens and the second negative lens are bonded together through a second lens bonding surface to form a second lens, and the third positive lens and the third negative lens are bonded together through a third lens bonding surface to form a third lens. The short-wave infrared microscopic imaging lens for an optical transmission function measuring instrument of the present invention has excellent imaging performance of short-wave microscopic imaging; has a wide tolerance capacity and is easy to process and adjust; has high testing efficiency and low cost, and is suitable for practical applications.

Description

Technical Field

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

[0002] Application areas of shortwave 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 wavelength band. It can monitor the heating conditions of industrial equipment, pipelines, circuits, and other structures, and promptly detect overheating and malfunctions. This characteristic has led to the widespread application of short-wave infrared lenses in various fields.

[0005] 2. Military field:

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

[0007] 3. Aerospace:

[0008] 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, shortwave infrared lenses have a wide range of applications and promising prospects. They will play an even more crucial role in the future, contributing significantly to national security, social stability, and economic development, while also bringing greater convenience and safety to people's lives. The imaging quality of shortwave infrared lenses in these applications is particularly important, and optical transfer function measuring instruments can objectively evaluate their imaging quality.

[0010] An optical transfer function (OTF) instrument consists of a target generator, collimator, and image analyzer. The shortwave infrared microscope imaging lens is a crucial component of the image analyzer, and its imaging results are crucial to the overall performance of the instrument. However, existing shortwave infrared optical lens TTF testing equipment must be imported from abroad, and the associated equipment costs are prohibitive. 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 coefficient 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 optical transmission coefficient 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] The 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 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 cemented together via a first lens cementing surface to form a first lens, the second positive lens and the second negative lens are cemented together via a second lens cementing surface to form a second lens, and the third positive lens and the third negative lens are cemented together via a third lens cementing surface to form a third lens.

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

[0018] The curvature radius of the exit surface of the first lens 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 refractive index of the material of the first negative lens is 1.8757903108 to 1.8986664940;

[0023] The refractive index of the material 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 indices 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 short-wave microscopic imaging performance, 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 corrects spherical aberration by matching the positive and negative optical powers of multiple lenses based on aberration theory; corrects positional chromatic aberration by selecting appropriate lens materials, curvature radii, and spacing; and controls system distance by double bonding. The imaging lens is designed to have imaging quality close to the diffraction limit, thus meeting the use requirements of an optical transmission function measuring instrument.

[0037] By using the short-wave infrared microscopic imaging lens for the optical transfer function measuring instrument of the present invention, the domestically developed optical transfer function measuring instrument can achieve the accuracy of the imported f4000 type equipment, which can save a lot of costs for purchasing foreign imported equipment for domestic purchasing units. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0039] Figure 1 The figure is a schematic diagram of the optical design of the short-wave infrared microscopic imaging lens for the optical transmission function measuring instrument of the present invention.

[0040] Figure 2 Schematic diagram of the diffuse spot of the short-wave infrared microscopic imaging lens used in the optical transmission function measuring instrument of the present invention.

[0041] Figure 3 Schematic diagram of field curvature and distortion of the short-wave infrared microscopic imaging lens used in the optical transmission function measuring instrument of the present invention.

[0042] Figure 4 The figure 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 according to the present invention. DETAILED DESCRIPTION

[0043] The short-wave infrared microscopic imaging lens for an optical transducer of the present invention comprises: a first lens, a second lens, and a third lens, arranged in sequence along the optical path propagation direction; an aperture stop is provided 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 cemented doublets, wherein the first lens is formed by cementing a first positive lens and a first negative lens; the second lens is formed by cementing a second positive lens and a second negative lens; and the third lens is formed by cementing a third positive lens and a third negative lens. The above-mentioned doublets are formed by cementing two lenses together.

[0044] The aperture stop is placed on the entrance surface of the first lens. It determines the system's entrance pupil diameter and numerical aperture. The size of the image formed by the aperture stop in object space is the entrance pupil diameter, while the size of the image formed by the image aperture is the exit pupil diameter. By placing the aperture stop on the first lens, the diameter of the light beam entering the system is determined by the front microscope objective.

[0045] The object under test is located 5.912 mm in front of the shortwave infrared microscope imaging lens. The shortwave infrared imaging device is located on the image plane. The shortwave infrared microscope imaging lens has a numerical aperture of 0.5 and a magnification of 10.

[0046] The lens of the present invention is a short-wave infrared achromatic optical imaging lens with a wavelength range of 1.0μm to 1.7μm. It receives short-wave spectrum signals through a short-wave infrared imaging device and obtains the optical transfer function of the lens under test 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 lanthanide glass, the fourth material may be crown glass, and the fifth material may be lanthanide glass.

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

[0055] The short-wave infrared microscopic imaging lens for an optical transmission function measuring instrument of the present invention comprises, from left to right along the optical path propagation direction, two surfaces of the first lens are respectively 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 cemented surface provided between the two surfaces; two surfaces of the 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 cemented surface provided between the two surfaces; and two surfaces of the 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 cemented surface provided between the two surfaces.

[0056] The short-wave infrared microscopic imaging lens for optical transducers of the present invention has a numerical aperture of 0.5 and an object height of 0.6 mm. This system is a small-field-of-view, large-aperture optical system with minimal field curvature, astigmatism, distortion, and chromatic aberration of magnification. The lens primarily considers spherical aberration and positional chromatic aberration related to the aperture. The short-wave infrared microscopic imaging lens for optical transducers of the present invention uses multiple lenses with matching positive and negative focal powers to correct spherical aberration; selects appropriate lens materials, curvature radii, and spacing to correct positional chromatic aberration; and selects cemented lenses to shorten the system length.

[0057] To further ensure imaging quality, in the short-wave infrared microscopic imaging lens for an optical transmission function measuring instrument of the present invention, the incident surface of the first lens is a plane, the radius of curvature of the cemented surface of the first lens is -3.874±0.01mm, and the radius of curvature of the exit surface of the first lens 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;

[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] To better ensure 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 doublet 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 will be described in detail below with reference to the accompanying drawings.

[0063] like Figure 1As shown, the shortwave infrared microscope imaging lens for an optical transmission function measuring instrument of the present invention comprises, from left to right, a first lens, a second lens, and a third lens. The aperture stop is placed on the incident surface of the first lens. The object to be measured is placed 5.912 mm to the left of the shortwave infrared microscope imaging lens, and the image plane imaging device is placed 97.278 mm to the right of the last surface on the right side of the shortwave infrared microscope imaging lens.

[0064] From left to right along the direction of optical propagation, the three surfaces of the first lens are the first lens incident surface S1, the first lens cemented 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 cemented 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 cemented surface S8 and the third lens exit surface S9. Among them, the first lens incident surface S1 is a plane, 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 curvature radius are as follows: Figure 1 As shown, the light propagates from left to right. If the center of curvature of the curvature radius is to the right of the surface vertex, the curvature radius is positive. If the center of curvature of the curvature radius is to the left of the surface vertex, the curvature radius 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 5.912 mm; the center distance between the first lens and the second lens is 0.2 mm; the center distance between the second lens and the third lens is 1.799 mm; and the center distance between the third lens and the image plane is 97.278 mm.

[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 parameters 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 signal measuring instrument of the present invention is a short-wave infrared microscopic imaging lens with a wavelength range from 1.0 μm to 1.7 μm. It receives short-wave infrared spectrum signals, analyzes and calculates the short-wave information of the imaging, and is applied to the optical transmission signal measuring instrument to test the imaging performance of short-wave infrared lenses in various fields such as military, aerospace, and industry.

[0081] Depend on Figure 2 The diffuse spot diagram shows that the diffuse spots in each field of view of the lens of the present invention are well corrected. The diffuse spot radius of the central field of view is within the Airy disk, the RMS value of the diffuse spot radius on the axis is 10.000 μm, and the RMS value of the diffuse spot radius at the maximum field of view outside the axis is 16.5 μm.

[0082] Depend on Figure 3 As shown in the field curvature and distortion diagrams, 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 curves shown that the optical transfer functions of the lens of the present invention in each field of view are 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 short-wave microscopic imaging performance, 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 corrects spherical aberration by matching the positive and negative optical powers of multiple lenses based on aberration theory; corrects positional chromatic aberration by selecting appropriate lens materials, curvature radii, and spacing; and controls system distance by double bonding. The imaging lens is designed to have imaging quality close to the diffraction limit, thus meeting the use requirements of an optical transmission function measuring instrument.

[0087] By using the short-wave infrared microscopic imaging lens for the optical transfer function measuring instrument of the present invention, the domestically developed optical transfer function measuring instrument can achieve the accuracy of the imported f4000 type equipment, which can save a lot of costs for purchasing foreign imported equipment for domestic purchasing units.

[0088] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will readily appreciate that other variations or modifications based on the above descriptions are possible. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications arising therefrom remain within the scope of protection of the present invention.

Claims

1. A short-wave infrared microscopic imaging lens for an optical transmission function measuring instrument, characterized in that: The 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 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 cemented together via a first lens cementing surface to form a first lens, the second positive lens and the second negative lens are cemented together via a second lens cementing surface to form a second lens, and the third positive lens and the third negative lens are cemented together via a third lens cementing surface to form a third lens. The incident surface of the first lens is a plane, and the curvature radius of the cemented surface of the first lens is -3.874±0.01mm. The curvature radius of the exit surface of the first lens 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 indices of the materials of the first and third positive lenses are 1.5768641658 to 1.5834787384 respectively; The refractive index of the material of the first negative lens is 1.8757903108 to 1.8986664940; The refractive index of the material 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 indices 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 crown glass respectively; 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±0.01 mm; the center distance between the first lens and the second lens is 0.200±0.01 mm; the center distance between the second lens and the third lens is 1.799±0.01 mm; and the center distance between the third lens and the image plane is 97.278±1 mm.

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 to 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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