A small-size micro-light lens for individual optical-electric detection

Abstract

The application provides a small-size low-light lens for single-soldier photoelectric detection, which comprises, in sequence along the direction of light incidence from left to right in an optical system, a first meniscus lens, a second meniscus lens, a third meniscus lens, a double-concave lens, a first double-convex lens, a second double-convex lens and a fourth meniscus lens. The lenses in the application are made of high-temperature-resistant glass materials. Except that the front convex surface of the second double-convex lens is designed as an aspheric surface, the rest of the lenses are designed as spherical surfaces, so as to solve the technical problems that the current imaging lens is heavy, the imaging effect of long-distance detection under different light conditions in the daytime and at night is poor, and the resolving power is difficult to maintain well in high and low temperature environments.

Description

Technical Field

[0001] This invention mainly relates to the field of lens technology, specifically to a small-sized low-light lens for individual soldier photoelectric detection. Background Technology

[0002] With the development of modern military optical detection technology, low-light lenses have unparalleled advantages in military, criminal investigation, security and other fields. Low-light lenses can obtain close-up images of details of objects 400 meters away under moonlight and 203 meters away under starlight, with a daytime effect.

[0003] For individual soldier optoelectronic detection systems, it is not only required to be lightweight to reduce the burden on the wearer's head, but also to ensure long-distance detection and high-quality image output under different lighting conditions during the day and night. At the same time, it is also required to have strong environmental adaptability to ensure that the lens can maintain good resolution in high and low temperature environments. However, existing imaging lenses are difficult to meet the above requirements.

[0004] It should be noted that the above content falls within the scope of the inventor's technical knowledge. Due to the vast and complex nature of the technical content in this field, the above content of this application does not necessarily constitute prior art. Summary of the Invention

[0005] 1. The technical problem that the invention aims to solve

[0006] The present invention provides a small-sized low-light lens for individual soldier photoelectric detection, in order to solve the technical problems existing in the background art.

[0007] 2. Technical Solution

[0008] To achieve the above objectives, the technical solution provided by this invention is as follows: a small-sized low-light lens for individual soldier photoelectric detection, comprising a first meniscus lens, a second meniscus lens, a third meniscus lens, a biconcave lens, a first biconvex lens, a second biconvex lens, and a fourth meniscus lens arranged sequentially along the light incident direction from left to right in an optical system. All lenses in this application are made of high-temperature resistant glass material. Except for the second biconvex lens, which has an aspherical design on its front convex surface, all other lenses in this application have a spherical design.

[0009] Furthermore, the biconcave lens and the first biconvex lens are combined to form a cemented lens.

[0010] Furthermore, the first meniscus lens is a meniscus lens with positive optical power.

[0011] Furthermore, the second meniscus lens is a meniscus lens with negative optical power, and the third meniscus lens is a meniscus lens with positive optical power.

[0012] Furthermore, the front convex surface of the second biconvex lens adopts an aspherical design, which optimizes aberrations, improves imaging quality, and reduces the number of lenses. The specific shape of the aspherical surface is represented by the following aspherical formula.

[0013] x=(h 2 / r) / (1+(1-(K+1)h 2 / r) 1 / 2 )+Ah 4 +Bh 6 +Ch 8 +Bh 10 +Ah 12

[0014] In the formula, x represents the direction of the optical axis, h represents the distance relative to the optical axis, r represents the radius of curvature of the reference sphere, K is the quadratic constant of the surface shape, and A, B, C, D, and E are the coefficients of higher-order terms in the aspherical formula. The quadratic constant of the front convex surface of the second biconvex lens is K = -100, and the coefficients of each higher-order term are A = 3.952821e-004, B = -5.133811e-005, C = 2.333543e-006, D = -8.091121e-008, and E = 9.009058e-010.

[0015] Furthermore, the first meniscus lens has a thickness of 1.3 mm, a front surface curvature radius of 7 mm to 8 mm, a rear surface curvature radius of -11 mm to -12 mm, a distance of 0.2 mm from the front surface of the second meniscus lens, and an optical glass designation of H-LAF3B.

[0016] The second meniscus lens has a thickness of 0.8 mm, a front surface curvature radius of 11 mm to 12 mm, a rear surface curvature radius of -5 mm to -6 mm, and a distance of 0.3 mm from the front surface of the third meniscus lens. The optical glass designation is H-K6.

[0017] The third meniscus lens has a thickness of 1.3 mm, a front surface curvature radius of 6 mm to 7 mm, a rear surface curvature radius of -13 mm to -14 mm, a distance of 0.3 mm from the front surface of the biconcave lens, and an optical glass designation of H-LAF3B.

[0018] The biconcave lens has a thickness of 0.9 mm, a front surface curvature radius of -6 mm to -7 mm, a rear surface curvature radius of -7 mm to -8 mm, and an optical glass designation of H-ZF6.

[0019] The first biconvex lens has a thickness of 2.5 mm, a front surface curvature radius of 7 mm to 8 mm, a rear surface curvature radius of 6 to 7 mm, and a distance of 0.2 mm from the front surface of the second biconvex lens. The optical glass designation is H-LAF3B.

[0020] The second biconvex lens has a thickness of 1.1 mm, a front surface curvature radius of 24 mm to 25 mm, a rear surface curvature radius of 52 mm to 53 mm, a distance of 0.2 mm from the front surface of the fourth meniscus lens, and an optical glass designation of H-ZK9B.

[0021] The four-curved lens has a thickness of 3.5 mm, a front surface curvature radius of 8 mm to 9 mm, a rear surface curvature radius of -6 to -7 mm, a distance of 3.2 mm from the focusing imaging surface, and an optical glass designation of H-LAF3B.

[0022] Furthermore, the aperture stop of the system is located between the third meniscus lens and the biconcave lens.

[0023] 3. Beneficial effects

[0024] Compared with the prior art, the technical solution provided by this invention has the following advantages:

[0025] 1. Long detection range: The system of this invention has a focal length of 10.33mm and a pixel size of 4μm. For a target object of 2m×2m, according to Johnson's criterion, the system has a detection range of 3.44km and an identification range of 861m, which can fully meet the needs of individual soldier night vision operations.

[0026] 2. Lightweight design: This invention adopts a design combining aspherical and spherical lenses, adjusting the lens parameters and spacing to minimize the number and size of lenses. The lens diameter is less than 8.5mm and the total length is no more than 18.5mm, significantly reducing the burden on the wearer's head.

[0027] 3. Wide temperature range and low distortion: The lens uses high-temperature resistant glass material and has a reasonable gap optimization design, so that the image quality is basically the same as that at room temperature in the range of -80℃ to +80℃; The Gaussian deformation symmetrical structure design and the introduction of aspherical surfaces greatly improve the distortion of the system, making it less than 1.9%, so the sensor does not need to perform distortion correction and the latency is greatly reduced.

[0028] 4. Clear imaging capability with Class B night vision compatibility: The system is designed to operate within a wavelength range of 0.45µm to 0.9µm. The coating process strictly adheres to the national military standard for Class B night vision compatibility, ensuring Class B night vision compatibility and enabling seamless switching between day and night imaging. The lens exhibits MTF greater than 0.6 at the limiting frequency of 125 lp / mm for the 0 field of view, greater than 0.5 for the 0.7 field of view, and greater than 0.2 for the 1 field of view, demonstrating good image quality. Currently paired with a 1920*1080 low-light sensor, it achieves 1080P image output.

[0029] 5. High practicality: Currently common miniaturized lenses, in order to reduce overall size, generally adopt multiple plastic double-sided aspherical designs, which have poor environmental adaptability and are difficult to manufacture. This invention adopts an all-glass design, combining spherical and single-sided aspherical surfaces, which has a wider operating temperature range and is relatively easier to manufacture.

[0030] It should be noted that structures not described in this invention are identical to or can be implemented using existing technologies, and will not be elaborated upon here, as they do not involve the design points or improvement directions of this invention. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the optical path structure of the present invention;

[0032] Figure 2 This is a schematic diagram of the distortion of the present invention;

[0033] Figure 3 This is a schematic diagram of the MTF of the present invention at room temperature;

[0034] Figure 4 This is a schematic diagram of the MTF of the present invention at -80°C;

[0035] Figure 5 This is a schematic diagram of the MTF of the present invention at +80°C.

[0036] Figure Labels

[0037] 1. First meniscus lens; 2. Second meniscus lens; 3. Third meniscus lens; 4. Biconcave lens; 5. First biconvex lens; 6. Second biconvex lens; 7. Fourth meniscus lens. Detailed Implementation

[0038] To facilitate understanding of the present invention, a more complete description of the invention will be given below with reference to the accompanying drawings, which illustrate several embodiments of the invention. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that the disclosure of the invention will be more thorough and complete.

[0039] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "page," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0040] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0041] In this invention, unless otherwise explicitly specified and limited, the terms "installed," "connected," "linked," "fixed," and "equipped" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0042] Example

[0043] See attached document Figure 1-5 A small-sized low-light lens for individual soldier photoelectric detection includes an optical system in which a first meniscus lens 1, a second meniscus lens 2, a third meniscus lens 3, a biconcave lens 4, a first biconvex lens 5, a second biconvex lens 6, and a fourth meniscus lens 7 are arranged sequentially along the incident direction of light from left to right. All lenses in this application are made of high-temperature resistant glass material. Except for the second biconvex lens 6, which has an aspherical design on its front convex surface, all other lenses in this application have a spherical design.

[0044] The biconcave lens 4 and the first biconvex lens 5 are combined to form a cemented lens. The cemented lens can effectively solve the chromatic aberration problem of the system and reduce the tolerance sensitivity of the optical system.

[0045] The first meniscus lens 1 is a meniscus lens with positive optical power, which tries to capture light rays at a large angle and prevents the incident light rays from having too large an angle.

[0046] The second meniscus lens 2 is a meniscus lens with negative optical power, and the third meniscus lens 3 is a meniscus lens with positive optical power. The two work together to share the optical power of the first meniscus lens 1 and converge the light angle, thereby reducing the diameter of the rear lens.

[0047] The second biconvex lens 6 adopts an aspherical design for its front convex surface, which optimizes aberrations, improves imaging quality, and reduces the number of lenses. The specific shape of the aspherical surface is represented by the following aspherical formula.

[0048] x=(h 2 / r) / (1+(1-(K+1)h 2 / r)1 / 2 )+Ah 4 +Bh 6 +Ch 8 +Bh 10 +Ah 12

[0049] In the formula, x represents the direction of the optical axis, h represents the distance relative to the optical axis, r represents the radius of curvature of the reference sphere, K is the quadratic constant of the surface shape, and A, B, C, D, and E are the coefficients of higher-order terms in the aspherical formula. The quadratic constant of the front convex surface of the second biconvex lens 6 is K = -100, and the coefficients of each higher-order term are A = 3.952821e-004, B = -5.133811e-005, C = 2.333543e-006, D = -8.091121e-008, and E = 9.009058e-010.

[0050] The first meniscus lens 1 has a thickness of 1.3 mm, a front surface curvature radius of 7 mm to 8 mm, a rear surface curvature radius of -11 mm to -12 mm, and a distance of 0.2 mm from the front surface of the second meniscus lens 2. The optical glass designation is H-LAF3B.

[0051] The second meniscus lens 2 has a thickness of 0.8 mm, a front surface curvature radius of 11 mm to 12 mm, a rear surface curvature radius of -5 mm to -6 mm, and a distance of 0.3 mm from the front surface of the third meniscus lens 3. The optical glass designation is H-K6.

[0052] The third meniscus lens 3 has a thickness of 1.3 mm, a front surface curvature radius of 6 mm to 7 mm, a rear surface curvature radius of -13 mm to -14 mm, and a distance of 0.3 mm from the front surface of the biconcave lens 4. The optical glass designation is H-LAF3B.

[0053] The biconcave lens 4 has a thickness of 0.9 mm, a front surface curvature radius of -6 mm to -7 mm, a rear surface curvature radius of -7 mm to -8 mm, and an optical glass designation of H-ZF6.

[0054] The first biconvex lens 5 has a thickness of 2.5 mm, a front surface curvature radius of 7 mm to 8 mm, a rear surface curvature radius of 6 to 7 mm, and a distance of 0.2 mm from the front surface of the second biconvex lens 6. The optical glass designation is H-LAF3B.

[0055] The second biconvex lens 6 has a thickness of 1.1 mm, a front surface curvature radius of 24 mm to 25 mm, a rear surface curvature radius of 52 mm to 53 mm, and a distance of 0.2 mm from the front surface of the fourth meniscus lens 7. The optical glass designation is H-ZK9B.

[0056] The four-lunar lens has a thickness of 3.5mm, a front surface curvature radius of 8mm-9mm, a rear surface curvature radius of -6mm--7mm, and a distance of 3.2mm from the focusing imaging plane. The optical glass designation is H-LAF3B. The system has a focal length of 10.33mm and a pixel size of 4μm. For a 2m × 2m target object, according to Johnson's criterion, the system's detection range is 3.44km and its recognition range is 861m, which fully meets the needs of individual soldier night vision operations.

[0057] The specific optical parameters of the optical system constructed according to the above embodiments are as follows;

[0058] The focal length is 10.33mm;

[0059] Distortion less than 1.9%, such as Figure 2 As shown;

[0060] Imaging quality is the same from -80℃ to 80℃ as at room temperature, such as Figure 3-5 As shown;

[0061] With a spectral range of 0.45µm to 0.9µm, it is compatible with night vision.

[0062] Total length 18.5mm;

[0063] With a pixel size of 4µm and a 1920*1080 sensor, the imaging area is 1 / 1.8 inches.

[0064] The relative aperture is 1 / 1.8;

[0065] The full field of view is 46°;

[0066] The image quality MTF is greater than 0.2 across the entire field of view at 125 lp / mm.

[0067] The system employs a double Gaussian symmetrical deformation structure, which effectively corrects distortion. This invention utilizes a combination of spherical and aspherical surfaces, reducing the number of lenses in the optical system while significantly improving the MTF transfer function. This results in a substantial enhancement of the sharpness, transmittance, and color reproduction of the final lens product.

[0068] The aperture stop of the system is located between the third meniscus lens 3 and the biconcave lens 4.

[0069] The above-described embodiments are merely illustrative of certain implementations of the present invention, and are described in a relatively specific and detailed manner. However, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements are all within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the appended claims.

Claims

1. A small-sized low-light lens for individual soldier photoelectric detection, characterized in that: The optical system includes a first meniscus lens (1), a second meniscus lens (2), a third meniscus lens (3), a biconcave lens (4), a first biconvex lens (5), a second biconvex lens (6), and a fourth meniscus lens (7) arranged sequentially along the incident direction of light from left to right. All of the above lenses are made of high-temperature resistant glass material. The first meniscus lens (1) has a thickness of 1.3 mm, a front surface curvature radius of 7 mm to 8 mm, a rear surface curvature radius of -11 mm to -12 mm, and a distance of 0.2 mm from the front surface of the second meniscus lens (2). The optical glass designation is H-LAF3B. The second meniscus lens (2) has a thickness of 0.8 mm, a front surface curvature radius of 11 mm to 12 mm, a rear surface curvature radius of -5 mm to -6 mm, and a distance of 0.3 mm from the front surface of the third meniscus lens (3). The optical glass designation is H-K6. The third meniscus lens (3) has a thickness of 1.3 mm, a front surface curvature radius of 6 mm to 7 mm, a rear surface curvature radius of -13 mm to -14 mm, and a distance of 0.3 mm from the front surface of the biconcave lens (4). The optical glass code is H-LAF3B. The biconcave lens (4) has a thickness of 0.9 mm, a front surface curvature radius of -6 mm to -7 mm, a rear surface curvature radius of -7 mm to -8 mm, and an optical glass designation of H-ZF6. The first biconvex lens (5) has a thickness of 2.5 mm, a front surface curvature radius of 7 mm to 8 mm, a rear surface curvature radius of 6 to 7 mm, and a distance of 0.2 mm from the front surface of the second biconvex lens (6). The optical glass code is H-LAF3B. The second biconvex lens (6) has a thickness of 1.1 mm, a front surface curvature radius of 24 mm to 25 mm, a rear surface curvature radius of 52 to 53 mm, and a distance of 0.2 mm from the front surface of the fourth meniscus lens (7). The optical glass code is H-ZK9B. The four-curved lens has a thickness of 3.5 mm, a front surface curvature radius of 8 mm to 9 mm, a rear surface curvature radius of -6 to -7 mm, a distance of 3.2 mm from the focusing imaging surface, and the optical glass designation is H-LAF3B. The aperture stop of the system is located between the third meniscus lens (3) and the biconcave lens (4).

2. The small-sized low-light lens for individual soldier photoelectric detection according to claim 1, characterized in that: The biconcave lens (4) and the first biconvex lens (5) are combined to form a cemented lens.

3. A small-sized low-light lens for individual soldier photoelectric detection according to claim 1, characterized in that: The first meniscus lens (1) is a meniscus lens with positive optical power.

4. A small-sized low-light lens for individual soldier photoelectric detection according to claim 3, characterized in that: The second meniscus lens (2) is a meniscus lens with negative optical power, and the third meniscus lens (3) is a meniscus lens with positive optical power.

5. A small-sized low-light lens for individual soldier photoelectric detection according to claim 1, characterized in that: The second biconvex lens (6) adopts an aspherical design on its front convex surface, which optimizes aberrations, improves imaging quality, and reduces the number of lenses. The specific shape of the aspherical surface is represented by the following aspherical formula. ； In the formula, x represents the direction of the optical axis, h represents the distance relative to the optical axis, r represents the radius of curvature of the reference sphere, K is the quadratic constant of the surface shape, and A, B, C, D, and E are the coefficients of higher-order terms in the aspherical formula. The quadratic constant of the front convex surface of the second biconvex lens (6) is K=-100, and the coefficients of each higher-order term are A= 3.952821e-004, B= -5.133811e-005, C= 2.333543e-006, D= -8.091121e-008, and E= 9.009058e-010.

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