A middle / long wave dual-color infrared lens

Abstract

The present application relates to infrared lens, specifically to a kind of middle wave / long wave dual-color infrared lens, solve the problem that existing infrared lens can only work in single infrared band, due to the camouflage of target, the change of temperature, the interference of false target and other reasons, leading to the weakening of the target information acquisition ability, the detection probability is reduced, the present application includes first lens, second lens, third lens, fourth lens and fifth lens arranged along optical path in turn, infrared light is converged to first image plane in turn through first lens, second lens, third lens is diverged to the infrared light after convergence, and infrared light after divergence is converged again on thermal imager target surface through fourth lens and fifth lens.

Description

Technical Field

[0001] This invention relates to infrared lenses, specifically to a mid-wave / long-wave dual-color infrared lens. Background Technology

[0002] Infrared imaging systems are a type of passive detection optical system. These systems can detect objects and targets by analyzing differences in the spectral distribution and motion characteristics of targets and interfering objects, thus identifying objects and targets that emit infrared radiation under infrared background radiation and other interference. Therefore, they have broad application prospects in target search, early warning detection, and forest fire prevention.

[0003] Currently, most infrared imaging systems are single-band imaging systems. The infrared lenses used to collect infrared light can only operate in a single mid-wave infrared band or a single long-wave infrared band within the atmospheric window. However, due to factors such as target camouflage, temperature changes, and interference from false targets, the ability of the infrared lenses of single-band imaging systems to acquire target information is weakened, and the detection probability is reduced. Therefore, there is a need for a dual-band infrared lens that can acquire target information in both mid-wave and long-wave bands simultaneously and accurately detect targets even under cluttered interference. Summary of the Invention

[0004] The purpose of this invention is to solve the technical problem that existing infrared lenses can only work in a single infrared band, and the ability to acquire target information is weakened and the detection probability is reduced due to target camouflage, temperature changes, interference from false targets, etc., so as to provide a mid-wave / long-wave dual-color infrared lens.

[0005] To solve the above-mentioned technical problems, the technical solution of the present invention is as follows:

[0006] A mid-wave / long-wave dual-color infrared lens is characterized by comprising a first lens, a second lens, a third lens, a fourth lens, and a fifth lens arranged sequentially along the optical path. Infrared light is converged to the first image plane by the first lens and the second lens, and the third lens diverges the converged infrared light. The diverged infrared light is then converged again to the target surface of the thermal imager by the fourth lens and the fifth lens. The incident surface side of the first lens is the object side, and the exit surface side of the fifth lens is the image side.

[0007] The first lens, the second lens, the third lens, the fourth lens, and the fifth lens satisfy the following relationship:

[0008]

[0009]

[0010]

[0011] Where Ф1-Ф5 represent the optical power of each lens, ν1-ν5 represent the dispersion coefficient of each lens, and Ф i The lens power is i = 1-5; n is the refractive index of each lens; r1 and r2 are the radii of curvature of the incident and exit surfaces of each lens; d is the center thickness of each lens; and f′ is the preset focal length of the mid-wave / long-wave dual-color infrared lens, which ranges from 100 to 110 mm.

[0012] Furthermore, the first lens is a meniscus Ge lens with negative optical power and a curvature direction facing the image side;

[0013] The second lens is a biconvex IRT6 lens with positive optical power;

[0014] The third lens is a meniscus Ge lens with positive optical power and a curvature direction facing the object side;

[0015] The fourth lens is a positive optical power, and the bending direction is towards the object side of the ZnS lens.

[0016] The fifth lens is a meniscus Ge lens with positive optical power and a curvature direction facing the image side.

[0017] Furthermore, the center thickness of the first lens is 4.5-5.5 mm, its incident surface is spherical, and its exit surface is aspherical;

[0018] The center thickness of the second lens is 7.7-8.7 mm, its incident surface is spherical, its exit surface is spherical, and the distance between the center of the incident surface of the second lens and the center of the exit surface of the first lens is 1-1.5 mm.

[0019] The center thickness of the third lens is 5.2-6.2 mm, its incident surface is aspherical, its exit surface is aspherical, and the distance between the center of the incident surface of the third lens and the center of the exit surface of the second lens is 92-97 mm.

[0020] The fourth lens has a center thickness of 3.5-4.5 mm, its incident surface is aspherical, and its exit surface is spherical. The distance between the center of the incident surface of the fourth lens and the center of the exit surface of the third lens is 8.5-9 mm.

[0021] The fifth lens has a center thickness of 2.5-3.5 mm, its incident surface is spherical, and its exit surface is aspherical. The distance between the center of the incident surface of the fifth lens and the center of the exit surface of the fourth lens is 25-30 mm.

[0022] Furthermore, the spherical radius of curvature of the incident surface of the first lens is 131-133 mm, and the aspherical radius of curvature of the exit surface is 88-100 mm;

[0023] The radius of curvature of the spherical surface of the second lens incident surface is 95-97 mm, and the radius of curvature of the spherical surface exiting surface is -434 to -436 mm.

[0024] The aspherical radius of curvature of the incident surface of the third lens is -9 to 11 mm, and the aspherical radius of curvature of the exit surface is -13 to 15 mm.

[0025] The aspherical radius of curvature of the incident surface of the fourth lens is -200 to 202 mm, and the spherical radius of curvature of the exit surface is -42 to 44 mm.

[0026] The spherical radius of curvature of the incident surface of the fifth lens is 22.367 mm, and the aspherical radius of curvature of the exit surface is 29-31 mm.

[0027] Furthermore, the center thickness of the first lens is 5 mm;

[0028] The center thickness of the second lens is 8.2 mm, and the distance between the center of the incident surface of the second lens and the center of the exit surface of the first lens is 1.24 mm.

[0029] The center thickness of the third lens is 5.78 mm, and the distance between the center of the incident surface of the third lens and the center of the exit surface of the second lens is 94.1 mm.

[0030] The center thickness of the fourth lens is 4.04 mm, and the distance between the center of the incident surface of the fourth lens and the center of the exit surface of the third lens is 8.65 mm.

[0031] The fifth lens has a center thickness of 3 mm, and the distance between the center of the incident surface of the fifth lens and the center of the exit surface of the fourth lens is 28.99 mm.

[0032] Furthermore, the spherical radius of curvature of the incident surface of the first lens is 132.475 mm, and the aspherical radius of curvature of the exit surface is 89.373 mm;

[0033] The radius of curvature of the spherical surface of the second lens incident on the incident surface is 96.332 mm, and the radius of curvature of the spherical surface of the exiting surface is -435.982 mm.

[0034] The aspherical radius of curvature of the incident surface of the third lens is -10.348 mm, and the aspherical radius of curvature of the exit surface is -14.205 mm.

[0035] The aspherical radius of curvature of the incident surface of the fourth lens is -201.809 mm, and the spherical radius of curvature of the exit surface is -43.754 mm.

[0036] The spherical radius of curvature of the incident surface of the fifth lens is 22.367 mm, and the aspherical radius of curvature of the exit surface is 30.363 mm.

[0037] Furthermore, the incident and exit surfaces of the first, second, third, fourth, and fifth lenses all satisfy the following aspherical equation:

[0038]

[0039] Where z is the sagitta, e is the curvature, k is the quadratic coefficient, r is the annular radius, and A, B, C, and D are the 4th, 6th, 8th, and 10th order aspherical coefficients, respectively.

[0040] Furthermore, the exit surface of the fifth lens satisfies the following diffraction surface equation:

[0041]

[0042] Among them, c m λ is a coefficient, r is the radius of the ring, and λ is the wavelength of the infrared light.

[0043] The beneficial effects of this invention are:

[0044] 1. The medium-wave / long-wave dual-color infrared lens provided by this invention adopts a five-lens, two-stage imaging design. Infrared light passes through the first lens and the second lens in sequence and converges onto the first image plane. The third lens diverges the converged infrared light. The diverged infrared light then passes through the fourth lens and the fifth lens in sequence and converges again onto the target surface of the thermal imager. The five lenses satisfy the following formula:

[0045]

[0046]

[0047]

[0048] Among them, Ф i V represents the optical power of each lens. i Let be the dispersion coefficient of each lens, n be the refractive index of each lens, r1 and r2 be the radii of curvature of the incident and exit surfaces of each lens, respectively, d be the center thickness of the lens, and f′ be the focal length.

[0049] The first formula is the total optical power distribution formula, the second formula is the axial chromatic aberration correction formula, and the third formula is the single lens optical power formula. By satisfying the above three formulas, the five lenses ensure that the infrared lens can image in both the mid-wave and long-wave bands, thereby improving the ability to acquire target information and increasing the detection probability.

[0050] 2. The present invention provides a mid-wave / long-wave dual-color infrared lens in which five lenses are made of three different materials. The first, third, and fifth lenses are all meniscus Ge lenses, the second lens is an IRT6 lens, and the fourth lens is a ZnS lens. The specific shapes of the five lenses are different, and the spacing between adjacent lenses is also different. In this way, the chromatic aberration of the dual-band system can be well corrected by combining the achromatic aberration of the three materials and the achromatic aberration of the harmonic diffraction optical elements. The entire lens group also achieves a thermal mid-wave and long-wave imaging confocal surface design by combining the achromatic aberration of the three materials and the achromatic aberration of the harmonic diffraction optical elements. There is no need to move the lens for focusing, and the imaging focal plane of the mid-wave band and the long-wave band is consistent. The overall structure is simple and the working stability is high. Attached Figure Description

[0051] Figure 1 This is an optical path diagram of an embodiment of the medium-wave / long-wave dual-color infrared lens of the present invention;

[0052] Figure 2 The MTF curve of the mid-wave / long-wave dual-color infrared lens embodiment of the present invention is shown in the mid-wave infrared band at a spatial frequency of 33 lp / mm.

[0053] Figure 3 The MTF curve of the medium-wave / long-wave dual-color infrared lens embodiment of the present invention is shown in the long-wave infrared band at a spatial frequency of 33 lp / mm.

[0054] Figure 4 This is a circle energy curve diagram of the mid-wave / long-wave dual-color infrared lens embodiment of the present invention in the mid-wave infrared band;

[0055] Figure 5 This is a circle energy curve diagram in the long-wave infrared band of the embodiment of the medium-wave / long-wave dual-color infrared lens of the present invention.

[0056] Explanation of reference numerals in the attached figures:

[0057] 1-First lens, 2-Second lens, 3-Third lens, 4-Fourth lens, 5-Fifth lens. Detailed Implementation

[0058] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0059] Reference Figures 1-5This invention provides a mid-wave / long-wave dual-color infrared lens, comprising a first lens 1, a second lens 2, a third lens 3, a fourth lens 4, and a fifth lens 5 arranged sequentially along the optical path. Infrared light emitted from the target object first passes through the first lens 1 and the second lens 2, converging onto the first image plane. Therefore, the incident surface of the first lens 1 is the object side. The converged infrared light is then diverged after passing through the third lens 3, resulting in better balance of system aberrations. The diverged infrared light then passes through the fourth lens 4 and the fifth lens 5, converging again onto the target surface of the thermal imager for infrared imaging. Therefore, the exit surface of the fifth lens 5 is the image side. The refractive index of the same material differs in different infrared bands. If the entire lens group is made of the same material, and while meeting the imaging requirements of the mid-wave band, the focal planes of the two bands do not coincide when imaging in the long-wave band. Therefore, the spacing between the lenses needs to be adjusted to adapt to the imaging requirements of the long-wave band, i.e., focusing. Therefore, this embodiment uses different materials to make these five lenses. Specifically, the first lens 1 is a meniscus Ge lens with negative optical power and a curvature direction towards the image side; the second lens 2 is a biconvex IRT6 lens with positive optical power; the third lens 3 is a meniscus Ge lens with positive optical power and a curvature direction towards the object side; the fourth lens 4 is a meniscus ZnS lens with positive optical power and a curvature direction towards the object side; and the fifth lens 5 is a meniscus Ge lens with positive optical power and a curvature direction towards the image side.

[0060] The center thickness of each of the five lenses has a range of values: the center thickness of the first lens 1 is 4.5-5mm, the center thickness of the second lens 2 is 7.7-8.7mm, the center thickness of the third lens 3 is 5.2-6.2mm, the center thickness of the fourth lens 4 is 3.5-4.5mm, and the center thickness of the fifth lens 5 is 2.5-3.5mm.

[0061] Because each of the five lenses can use a different center thickness value within a certain range, the distance between the five lenses also has a range of values. The distance between the center of the incident surface of the second lens 2 and the center of the exit surface of the first lens 1 is 1-1.5mm; the distance between the center of the incident surface of the third lens 3 and the center of the exit surface of the second lens 2 is 92-97mm; the distance between the center of the incident surface of the fourth lens 4 and the center of the exit surface of the third lens 3 is 8.5-9mm; and the distance between the center of the incident surface of the fifth lens 5 and the center of the exit surface of the fourth lens 4 is 25-30mm.

[0062] In this embodiment, the center thickness of the first lens 1 is 5mm, the center thickness of the second lens 2 is 8.2mm, the center thickness of the third lens 3 is 5.78mm, the center thickness of the fourth lens 4 is 4.04mm, and the center thickness of the fifth lens 5 is 3mm. Furthermore, the distance between the center of the incident surface of the second lens 2 and the center of the exit surface of the first lens 1 is 1.24mm, the distance between the center of the incident surface of the third lens 3 and the center of the exit surface of the second lens 2 is 94.1mm, the distance between the center of the incident surface of the fourth lens 4 and the center of the exit surface of the third lens 3 is 8.65mm, and the distance between the center of the incident surface of the fifth lens 5 and the center of the exit surface of the fourth lens 4 is 28.99mm.

[0063] The five lenses also have different shapes. The first lens 1 has a spherical incident surface and an aspherical exit surface; the second lens 2 has a spherical incident surface and an aspherical exit surface; the third lens 3 has an aspherical incident surface and an aspherical exit surface; the fourth lens 4 has an aspherical incident surface and a spherical exit surface; and the fifth lens 5 has a spherical incident surface and an aspherical exit surface. All lenses have radii of curvature on their incident and exit surfaces, and these radii also have a range of values. Specifically, the spherical radius of curvature of the incident surface of the first lens 1 is 131-133 mm, and the aspherical radius of curvature of the exit surface is 88-100 mm; the spherical radius of curvature of the incident surface of the second lens 2 is 95-97 mm, and the spherical radius of curvature of the exit surface is -434-436 mm; the aspherical radius of curvature of the incident surface of the third lens 3 is -9-11 mm, and the aspherical radius of curvature of the exit surface is -13-15 mm; the aspherical radius of curvature of the incident surface of the fourth lens 4 is -200-202 mm, and the spherical radius of curvature of the exit surface is -42-44 mm; and the spherical radius of curvature of the incident surface of the fifth lens 5 is 22.367 mm, and the aspherical radius of curvature of the exit surface is 29-31 mm.

[0064] In this embodiment, the spherical radius of curvature of the incident surface of the first lens 1 is 132.475 mm, and the aspherical radius of curvature of the exit surface is 89.373 mm; the spherical radius of curvature of the incident surface of the second lens 2 is 96.332 mm, and the spherical radius of curvature of the exit surface is -435.982 mm; the aspherical radius of curvature of the incident surface of the third lens 3 is -10.348 mm, and the aspherical radius of curvature of the exit surface is -14.205 mm; the aspherical radius of curvature of the incident surface of the fourth lens 4 is -201.809 mm, and the spherical radius of curvature of the exit surface is -43.754 mm; and the spherical radius of curvature of the incident surface of the fifth lens 5 is 22.367 mm, and the aspherical radius of curvature of the exit surface is 30.363 mm.

[0065] And the five lenses satisfy the following relationship:

[0066]

[0067]

[0068]

[0069] The first formula is the total optical power allocation formula, the second formula is the axial chromatic aberration correction formula, and the third formula is the single lens optical power formula. These three formulas allocate the initial structural parameters of the entire lens group. In the formulas, Ф1-Ф5 represent the optical power of each lens, ν1-ν5 represent the dispersion coefficient of each lens, and Ф... i denoted as the lens power, i = 1-5; n is the refractive index of each lens, where the dispersion coefficient and refractive index of each lens are inherent properties of the lens material. These data are known when the lens material is known, and their specific values ​​are not listed here; r1 and r2 are the radii of curvature of the incident and exit surfaces of each lens, d is the center thickness of each lens, and f′ is the preset focal length of the mid-wave / long-wave dual-color infrared lens, which ranges from 100-110mm.

[0070] In this embodiment, the specific parameters of the five lenses are shown in the table below:

[0071]

[0072]

[0073] In this embodiment, f′ is 105mm and F-number is 2. The entire infrared lens is suitable for a large target surface mid-wave / long-wave dual-color infrared thermal imager with a high resolution of 640×512 and a pixel size of 15μm×15μm.

[0074] Furthermore, the incident and exit surfaces of all five lenses satisfy the following aspherical equation:

[0075]

[0076] Where z is the sag; e is the curvature (i.e., the reciprocal of the radius of curvature); k is the quadratic coefficient; r is the radius of the annulus; A, B, C, and D are the aspheric coefficients of the 4th, 6th, 8th, and 10th orders, respectively. The aspheric coefficients of each surface have been given in the table above. The coefficients not given are zero. In this embodiment, the quadratic coefficient k in the aspheric equation is also zero.

[0077] In this embodiment, the annular radius of the first lens 1 is 30mm, the annular radius of the second lens 2 is 30mm, the annular radius of the third lens 3 is 10mm, the annular radius of the fourth lens 4 is 12.5mm, and the annular radius of the fifth lens 5 is 8.5mm.

[0078] Furthermore, the exit surface of the fifth lens 5 satisfies the following diffraction surface equation:

[0079]

[0080] Among them, c m λ is a coefficient, which has been given in the table above; r is the ring radius, the ring radius of the fifth lens 5 is 8.5 mm, and λ is the infrared wavelength, which is generally 3.7-4.8 μm, but is taken as 4.2 μm in the formula.

[0081] like Figure 2 , Figure 3 As shown, the MTF curves at a spatial frequency of 33 lp / mm in the mid-wave and long-wave infrared bands demonstrate that the infrared lens of this invention exhibits good imaging quality in both the mid-wave and long-wave infrared bands. Figure 4 , Figure 5 The encircling circle energy curves of the infrared lens in the mid-wave and long-wave infrared bands shown indicate that the energy of the entire lens field of view is relatively concentrated, which can meet the requirements for detecting infrared targets. The lens of this invention adopts a secondary imaging structure. The infrared light emitted by the target first passes through the first lens 1 and the second lens 2 sequentially to converge onto the first image plane. The converged infrared light is then diverged after passing through the third lens 3. The diverged infrared light then passes through the fourth lens 4 and the fifth lens 5 and converges again onto the target surface of the thermal imager for infrared imaging. Among these five lenses, the first lens 1, the third lens 2, the second lens 3, the fourth lens 4, the fifth lens 5, and the fifth lens 5 are used for infrared imaging. Lens 3 and the fifth lens 5 are both meniscus Ge lenses, the second lens 2 is an IRT6 lens, and the fourth lens 4 is a ZnS lens. The specific structures of the five lenses are also different, and the spacing between them is also different. The entire lens group achieves a thermal mid-wave and long-wave imaging confocal surface design by combining achromatic and harmonic diffractive optical elements made of three materials. It does not require moving the lens to focus, keeps the imaging focal plane of the mid-wave and long-wave bands consistent, and has good imaging quality and stable image plane in both mid-wave and long-wave bands. The entire infrared lens has a simple structure and high stability.

[0082] The embodiments described above are merely illustrative of specific implementations of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made to the technical solutions of the present invention by those skilled in the art without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A mid-wave / long-wave dual-color infrared lens, characterized in that: It is composed of a first lens (1), a second lens (2), a third lens (3), a fourth lens (4) and a fifth lens (5) arranged in sequence along the optical path. Infrared light is converged to the first image plane by the first lens (1) and the second lens (2) in sequence. The third lens (3) diverges the converged infrared light. The diverged infrared light is converged again to the target surface of the thermal imager by the fourth lens (4) and the fifth lens (5). The incident surface side of the first lens (1) is the object side, and the exit surface side of the fifth lens (5) is the image side. The first lens (1), the second lens (2), the third lens (3), the fourth lens (4), and the fifth lens (5) satisfy the following relationship: ； ； ； in, These are the optical powers of each lens. These are the dispersion coefficients of each lens, Ф i Let i be the optical power of the lens, i = 1-5; n be the refractive index of each lens; r1 and r2 be the radii of curvature of the incident and exit surfaces of each lens; and d be the center thickness of each lens. The preset focal length for the mid-wave / long-wave dual-color infrared lens is 100-110mm. The first lens (1) is a meniscus Ge lens with negative optical power and a curvature direction facing the image side; The second lens (2) is a biconvex IRT6 lens with positive optical power; The third lens (3) is a meniscus Ge lens with positive optical power and a curvature direction facing the object side; The fourth lens (4) is a positive optical power, and the bending direction is towards the object side of the ZnS lens; The fifth lens (5) is a positive optical power, and the bending direction is towards the image side of the meniscus Ge lens.

2. The mid-wave / long-wave dual-color infrared lens according to claim 1, characterized in that: The center thickness of the first lens (1) is 4.5-5.5 mm, its incident surface is spherical, and its exit surface is aspherical; The center thickness of the second lens (2) is 7.7-8.7 mm, its incident surface is spherical, its exit surface is spherical, and the distance between the center of the incident surface of the second lens (2) and the center of the exit surface of the first lens (1) is 1-1.5 mm. The center thickness of the third lens (3) is 5.2-6.2 mm, its incident surface is aspherical, its exit surface is aspherical, and the distance between the center of the incident surface of the third lens (3) and the center of the exit surface of the second lens (2) is 92-97 mm. The center thickness of the fourth lens (4) is 3.5-4.5 mm, its incident surface is aspherical, and its exit surface is spherical. The distance between the center of the incident surface of the fourth lens (4) and the center of the exit surface of the third lens (3) is 8.5-9 mm. The fifth lens (5) has a center thickness of 2.5-3.5 mm, its incident surface is spherical, and its exit surface is aspherical. The distance between the center of the incident surface of the fifth lens (5) and the center of the exit surface of the fourth lens (4) is 25-30 mm.

3. The mid-wave / long-wave dual-color infrared lens according to claim 2, characterized in that: The spherical radius of curvature of the incident surface of the first lens (1) is 131-133 mm, and the aspherical radius of curvature of the exit surface is 88-100 mm; The radius of curvature of the spherical surface of the second lens (2) is 95-97 mm, and the radius of curvature of the spherical surface of the exiting surface is -434--436 mm; The aspherical radius of curvature of the incident surface of the third lens (3) is -9 to 11 mm, and the aspherical radius of curvature of the exit surface is -13 to 15 mm. The aspherical radius of curvature of the incident surface of the fourth lens (4) is -200 to 202 mm, and the spherical radius of curvature of the exit surface is -42 to 44 mm. The fifth lens (5) has an incident surface spherical curvature radius of 22.367 mm and an exit surface aspherical curvature radius of 29-31 mm.

4. The mid-wave / long-wave dual-color infrared lens according to claim 3, characterized in that: The center thickness of the first lens (1) is 5 mm; The center thickness of the second lens (2) is 8.2 mm, and the distance between the center of the incident surface of the second lens (2) and the center of the exit surface of the first lens (1) is 1.24 mm. The center thickness of the third lens (3) is 5.78 mm, and the distance between the center of the incident surface of the third lens (3) and the center of the exit surface of the second lens (2) is 94.1 mm. The center thickness of the fourth lens (4) is 4.04 mm, and the distance between the center of the incident surface of the fourth lens (4) and the center of the exit surface of the third lens (3) is 8.65 mm. The fifth lens (5) has a center thickness of 3 mm, and the distance between the center of the incident surface of the fifth lens (5) and the center of the exit surface of the fourth lens (4) is 28.99 mm.

5. The mid-wave / long-wave dual-color infrared lens according to claim 4, characterized in that: The first lens (1) has an incident surface with a spherical radius of curvature of 132.475 mm and an exit surface with an aspherical radius of curvature of 89.373 mm. The second lens (2) has an incident surface radius of curvature of 96.332 mm and an exit surface radius of curvature of -435.982 mm. The aspherical radius of curvature of the incident surface of the third lens (3) is -10.348 mm, and the aspherical radius of curvature of the exit surface is -14.205 mm; The aspherical radius of curvature of the incident surface of the fourth lens (4) is -201.809 mm, and the spherical radius of curvature of the exit surface is -43.754 mm. The fifth lens (5) has an incident surface spherical radius of curvature of 22.367 mm and an exit surface aspherical radius of curvature of 30.363 mm.

6. The mid-wave / long-wave dual-color infrared lens according to claim 5, characterized in that: The incident and exit surfaces of the first lens (1), the second lens (2), the third lens (3), the fourth lens (4), and the fifth lens (5) all satisfy the following aspherical equation: ； Where z is the sagitta, e is the curvature, k is the quadratic coefficient, r is the annular radius, and A, B, C, and D are the 4th, 6th, 8th, and 10th order aspherical coefficients, respectively.

7. The mid-wave / long-wave dual-color infrared lens according to claim 6, characterized in that: The exit surface of the fifth lens (5) satisfies the following diffraction surface equation: ； in, is a coefficient, and r is the radius of the ring. It is the wavelength of infrared light.

Images