Low-cost light-small high-resolution common-aperture dual-band refrigeration optical system

Abstract

The utility model discloses a low-cost light-small high-resolution common-aperture dual-waveband refrigeration optical system. The refrigeration optical system is characterized in that a first lens, a second lens, a third lens, a fourth lens, detector protection glass, a cold diaphragm and a detector photosensitive surface are sequentially arranged in the light propagation direction from outside to inside. The first lens, the second lens, the third lens, the fourth lens, the detector protection glass, the cold diaphragm and the detector photosensitive surface are coaxially arranged. The optical system is used for receiving inherent infrared radiation passing through a target and a background and converging the infrared radiation to a photosensitive surface of the medium / long wave dual-band refrigeration detector to realize photoelectric conversion, and the system has relatively high sensitivity and relatively small spatial resolution, and can obtain radiation characteristics of the target in medium / long waves at night or under complex meteorological conditions; a high-performance imaging system is realized, and detection advantages and complementarity of different spectrum bands can be fully utilized to detect, identify and accurately position a target in a complex environment.

Description

Technical Field

[0001] The utility model belongs to the technical field of optical imaging, and in particular relates to a low-cost, lightweight, small-sized, high-resolution, common-aperture, dual-band refrigeration optical system. Background Art

[0002] Dual-band infrared focal plane arrays have been developed for nearly two decades. They can be sensitive to different spectral bands on individual pixels, optimize the detection and recognition functions of the sensor system, and can identify targets under conditions where one wavelength cannot identify the target, thereby forming the best image in various complex atmospheric environments and battlefield scenes, providing better target detection and recognition capabilities, and further improving mission robustness. However, these detectors are generally cryogenically cooled, and the cost for higher-performance applications is high. The optical systems associated with these systems are also complex and costly. Therefore, it is particularly important to design a low-cost, miniaturized, high-resolution medium / long-wave common-aperture dual-band cooled optical system. The system can be widely used in military, security, medical, energy exploration and other fields. Summary of the invention

[0003] The purpose of the utility model is to realize the low-cost, miniaturized, dual-band, common aperture, high-resolution design of a dual-band refrigeration optical system. The utility model provides a low-cost, light, small, high-resolution common aperture dual-band refrigeration optical system.

[0004] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0005] A low-cost, lightweight, small-sized, high-resolution, common-aperture dual-band refrigerated optical system, characterized in that: a first lens, a second lens, a third lens, a fourth lens, a detector protective glass, a cold diaphragm and a detector photosensitive surface are sequentially arranged from outside to inside in the direction of light propagation. The first lens, the second lens, the third lens, the fourth lens, the detector protective glass, the cold diaphragm and the detector photosensitive surface are coaxially arranged. The optical system is used to receive infrared radiation inherent to the target and the background, and converge it onto the photosensitive surface of the medium / long-wave dual-band refrigerated detector to achieve photoelectric conversion. The system has high sensitivity and small spatial resolution, and can obtain the radiation characteristics of the target in the medium / long wave at night or under complex meteorological conditions to achieve a high-performance imaging system, which can make full use of the detection advantages and complementarity of different spectral bands to detect, identify and accurately locate targets in complex environments.

[0006] Furthermore, the optical power of the first lens and the third lens is negative; the optical power of the second lens and the fourth lens is positive; the first lens, the second lens, the third lens and the fourth lens are aspherical lenses; and the optical parameters of the optical system are shown in Table 1.

[0007] Table 1 Optical system parameters

[0008]

[0009] Further, as described in Table 1, the S1 surface of the first lens is a spherical surface, and the S2 surface is an aspherical surface; the S3 surface of the second lens is an aspherical surface, and the S4 surface is a spherical surface; the S5 surface of the third lens is an aspherical surface, and the S6 surface is a spherical surface; the S7 surface of the fourth lens is an aspherical surface, and the S8 surface is a spherical surface; the aspherical surface equation is (1):

[0010] The aspheric equation is

[0011]

[0012] In the formula: c is the paraxial curvature radius, r is the curvature radius; K is the quadratic surface constant; A, B, C, D, E are aspheric coefficients.

[0013] Furthermore, the surface shape of the aspheric surface of the optical system is shown in Table 2.

[0014] Table 2 Aspheric surface parameters of optical system

[0015] surface K A B C D E S2 0.28835 -2.199E-006 -1.532E-009 -9.824E-012 1.441E-014 -2.676E-017 S3 0 -1.324E-006 -4.435E-010 1.575E-012 -3.347E-015 2.561E-018 S5 -15.4147 7.042E-006 -1.345E-008 7.786E-011 -3.266E-013 4.814E-016 S7 -0.0205 -1.647E-006 5.778E-009 -4.680E-011 2.423E-013 -4.580E-016

[0016] Furthermore, the optical system has an operating band of 3.7μm~4.8μm&7.7μm~10.3μm, a focal length of 19mm, an F number of 2, a field of view of 44°×35.5°, a matching array scale of 1280×1024, a pixel size of 12μm, and a high-resolution medium / long wave dual-band Stirling cooled detector. At 42lp / mm, the medium wave transfer function, the on-axis field of view transfer function value is ≥0.45, and the off-axis transfer function value is ≥0.4; the long wave transfer function, the on-axis field of view transfer function value is ≥0.18, and the off-axis transfer function value is ≥0.1, and the system distortion is ≤4.9%.

[0017] Furthermore, the optical system is designed to adopt a one-time imaging 4-piece structure, and domestically produced chalcogenide glasses IRG201, ZNSE and BAF2 with good stability and mature processing technology are selected as lens materials. When only 4 optical lenses are used, advanced aberration theory is applied to reasonably match the optical focal length and dispersion coefficient, and optical residual aberrations are corrected by optical aspheric surfaces to achieve medium / long wave dual-band common aperture imaging. The optical system has an overall size of <φ50mm×120mm and a total optical weight of <190g. The optical system has the technical characteristics of excellent imaging quality, a small number of lenses, high transmittance, a simple and compact structure, easy processing and calibration, low cost, and suitability for mass production.

[0018] The beneficial effects of the present invention relative to the prior art are:

[0019] 1. The optical system described in the present invention has an operating band of 3.7μm~4.8μm&7.7μm~10.3μm, a focal length of 19mm, an F number of 2, a field of view of 44°×35.5°, and a full field of view distortion of ≤4.9%. The detector uses a dual-band Stirling cooled detector with a high resolution of 1280×1024 and a pixel size of 12μm. The system is a small F number medium / long wave dual-band common aperture cooled optical system. The design adopts a one-time imaging 4-piece optical structure, with an overall size of <φ50mm×120mm and a total weight of <190g. The dual-band common aperture optical system is the best way to achieve miniaturization, lightweight and low power consumption of the optoelectronic imaging system, can obtain the radiation characteristics of the target in the medium / long wave, realize a high-performance imaging system, and can make full use of the detection advantages and complementarity of different spectral bands to detect, identify and accurately locate targets in complex environments.

[0020] 2. The transfer function of the optical system recorded in the present invention is that at 42lp / mm, the medium-wave transfer function, the on-axis field transfer function value is ≥0.45, and the off-axis transfer function value is ≥0.4; the long-wave transfer function, the on-axis field transfer function value is ≥0.18, and the off-axis transfer function value is ≥0.1; the system has excellent imaging quality, a single pixel angular field of view of less than 0.63mrad, high resolution, long detection distance, and outstanding performance characteristics.

[0021] 3. The optical system uses domestically produced chalcogenide glasses IRG201, ZNSE and BAF2 with good stability and mature processing technology as lens materials. When using only 4 optical lenses, it applies advanced aberration theory, reasonably matches the optical focal length and dispersion coefficient, and corrects the optical residual aberration through optical aspheric surfaces to achieve medium / long wave dual-band common aperture imaging. It has a small number of lenses, high transmittance, strong environmental adaptability, low cost, and is suitable for mass production. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a structural diagram of a low-cost, lightweight, small, high-resolution, common-aperture, dual-band cooling optical system;

[0023] Figure 2 is the medium wave modulation transfer function curve;

[0024] Figure 3 is the long wave modulation transfer function curve;

[0025] Figure 4 is the distortion and field curvature curve of the medium wave optical system;

[0026] Figure 5 is the distortion and field curvature curve of the long-wave optical system;

[0027] In the figure: 1, first lens, 2, second lens, 3, third lens, 4, fourth lens, 5, detector protection glass, 6, cold aperture, 7, detector photosensitive surface. DETAILED DESCRIPTION

[0028] The present invention is described in detail below in conjunction with the accompanying drawings.

[0029] Example 1

[0030] This embodiment describes a low-cost, lightweight, small-sized, high-resolution, common-aperture dual-band refrigerated optical system. In the direction of light propagation, a first lens, a second lens, a third lens, a fourth lens, a detector protective glass, a cold aperture, and a detector photosensitive surface are sequentially arranged from outside to inside. The first lens, the second lens, the third lens, the fourth lens, the detector protective glass, the cold aperture, and the detector photosensitive surface are coaxially arranged. The optical system is used to receive infrared radiation inherent to the target and the background, and converge it onto the photosensitive surface of the medium / long-wave dual-band refrigerated detector to achieve photoelectric conversion. The system has high sensitivity and small spatial resolution. It can obtain the radiation characteristics of the target in the medium / long wave at night or under complex meteorological conditions to achieve a high-performance imaging system. It can make full use of the detection advantages and complementarity of different spectral bands to detect, identify, and accurately locate targets in complex environments.

[0031] The specific purpose of this technical solution is to achieve a low-cost, miniaturized, dual-band, common-aperture high-resolution design of a dual-band cooled optical system. Based on domestic optical materials, a one-time imaging 4-piece optical structure is used, and a Stirling-cooled array scale 1280×1024 medium / long-wave dual-band infrared detector with a pixel size of 12μm is selected as a receiving device. A low-cost, lightweight, small, high-resolution common-aperture dual-band cooled optical system is designed to realize the detection, identification and precise positioning of targets.

[0032] Example 2

[0033] This embodiment describes a low-cost, lightweight, small-sized, high-resolution, common-aperture dual-band refrigerated optical system. In the direction of light propagation, a first lens, a second lens, a third lens, a fourth lens, a detector protective glass, a cold aperture, and a detector photosensitive surface are sequentially arranged from outside to inside. The first lens, the second lens, the third lens, the fourth lens, the detector protective glass, the cold aperture, and the detector photosensitive surface are coaxially arranged. The optical system is used to receive infrared radiation inherent to the target and the background, and converge it onto the photosensitive surface of the medium / long-wave dual-band refrigerated detector to achieve photoelectric conversion. The system has high sensitivity and small spatial resolution. It can obtain the radiation characteristics of the target in the medium / long wave at night or under complex meteorological conditions to achieve a high-performance imaging system. It can make full use of the detection advantages and complementarity of different spectral bands to detect, identify, and accurately locate targets in complex environments.

[0034] The optical power of the first lens and the third lens of the optical system is negative; the optical power of the second lens and the fourth lens is positive; the first lens, the second lens, the third lens and the fourth lens are aspherical lenses; the parameters are shown in Table 1 and Table 2.

[0035] This technical solution defines the material, quantity and surface shape of each lens. The design adopts a one-time imaging 4-piece structure, and selects domestic chalcogenide glasses IRG201, ZNSE and BAF2 with good stability and mature processing technology as lens materials. When only 4 optical lenses are used, advanced aberration theory is used to reasonably match the focal length and dispersion coefficient, and optical residual aberration is corrected by optical aspheric surface to achieve medium / long wave dual-band common aperture imaging. The outer dimensions of the optical system are <φ50mm×120mm, and the total optical weight is <190g. The optical system has the technical characteristics of excellent imaging quality, small number of lenses, high transmittance, simple and compact structure, easy processing and calibration, low cost, and suitable for mass production.

[0036] Example 3

[0037] This embodiment describes a low-cost, lightweight, small-sized, high-resolution, common-aperture dual-band refrigerated optical system. In the direction of light propagation, a first lens, a second lens, a third lens, a fourth lens, a detector protective glass, a cold aperture, and a detector photosensitive surface are sequentially arranged from outside to inside. The first lens, the second lens, the third lens, the fourth lens, the detector protective glass, the cold aperture, and the detector photosensitive surface are coaxially arranged. The optical system is used to receive infrared radiation inherent to the target and the background, and converge it onto the photosensitive surface of the medium / long-wave dual-band refrigerated detector to achieve photoelectric conversion. The system has high sensitivity and small spatial resolution. It can obtain the radiation characteristics of the target in the medium / long wave at night or under complex meteorological conditions to achieve a high-performance imaging system. It can make full use of the detection advantages and complementarity of different spectral bands to detect, identify, and accurately locate targets in complex environments.

[0038] The optical system has an operating band of 3.7μm to 4.8μm and 7.7μm to 10.3μm, a focal length of 19mm, an F number of 2, a field of view of 44°×35.5°, and a full field of view distortion of ≤4.9%. The detector uses a dual-band Stirling cooling detector with a high resolution of 1280×1024 and a pixel size of 12μm. At 42lp / mm, the medium-wave transfer function, the on-axis field of view transfer function value is ≥0.45, and the off-axis transfer function value is ≥0.4; the long-wave transfer function, the on-axis field of view transfer function value is ≥0.18, and the off-axis transfer function value is ≥0.1. The system has excellent imaging quality, and the single-pixel opening angle is less than 0.63mrad.

[0039] This technical solution defines the working band, focal length, F number, field of view, distortion, detector resolution, pixel size, optical transfer function, pixel angle and other technical parameters of the optical system. The system has the characteristics of excellent imaging quality, high resolution and outstanding performance characteristics. It is the best way to achieve miniaturization, lightweight and low power consumption of optoelectronic imaging systems.

[0040] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A low-cost, lightweight, high-resolution, common-aperture, dual-band cooling optical system, characterized by: A first lens (1), a second lens (2), a third lens (3), a fourth lens (4), a detector protection glass (5), a cold diaphragm (6) and a detector photosensitive surface (7) are arranged in sequence from outside to inside in the direction of light propagation; the first lens (1), the second lens (2), the third lens (3), the fourth lens (4), the detector protection glass (5), the cold diaphragm (6) and the detector photosensitive surface (7) are arranged coaxially; the optical system is used to receive infrared radiation inherent to the target and the background, and converge it onto the photosensitive surface of the medium / long wave dual-band refrigerated detector to achieve photoelectric conversion; The optical power of the first lens (1) and the third lens (3) is negative; the optical power of the second lens (2) and the fourth lens (4) is positive; the first lens (1), the second lens (2), the third lens (3) and the fourth lens (4) are aspherical lenses; the optical parameters of the optical system are shown in Table 1; Table 1 Optical system parameters As shown in Table 1, the S1 surface of the first lens (1) is a spherical surface, and the S2 surface is an aspherical surface; the S3 surface of the second lens (2) is an aspherical surface, and the S4 surface is a spherical surface; the S5 surface of the third lens (3) is an aspherical surface, and the S6 surface is a spherical surface; the S7 surface of the fourth lens (4) is an aspherical surface, and the S8 surface is a spherical surface; the surface shapes of the aspherical surfaces of the optical system are shown in Table 2. Table 2 Aspheric surface parameters of optical system 2. According to claim 1, a low-cost, lightweight, high-resolution, common-aperture, dual-band cooling optical system is characterized by: The optical system is designed with a one-time imaging 4-piece structure, and uses domestically produced chalcogenide glasses IRG201, ZNSE and BAF2 with good stability and mature processing technology as lens materials. When only 4 optical lenses are used, advanced aberration theory is applied to reasonably match the optical focal length and dispersion coefficient, and optical residual aberrations are corrected through optical aspheric surfaces to achieve medium / long wave dual-band common aperture imaging. The overall dimensions of the optical system are <φ50mm×120mm, and the total optical weight is <190g.

3. According to claim 1, a low-cost, lightweight, high-resolution, common-aperture, dual-band cooling optical system is characterized by: The optical system has an operating band of 3.7 μm to 4.8 μm and 7.7 μm to 10.3 μm, a focal length of 19 mm, an F number of 2, a field of view of 44°×35.5°, a matching array scale of 1280×1024, and a pixel size of 12 μm. The high-resolution medium / long-wave dual-band Stirling cooled detector has a medium-wave transfer function at 42 lp / mm, an on-axis field of view transfer function value of ≥0.45, and an off-axis transfer function value of ≥0.4; the long-wave transfer function has an on-axis field of view transfer function value of ≥0.18, and an off-axis transfer function value of ≥0.1, a system distortion of ≤4.9%, and excellent system imaging quality.

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