Medium / long wave composite common aperture refrigeration infrared athermalization optical system

Abstract

The invention provides a medium / long wave composite common aperture refrigeration infrared athermalization optical system, and belongs to the technical field of optical imaging. And the problems of medium / long wave compounding, common aperture and athermalization design of the refrigeration infrared imaging detection system are solved. The optical system comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens, a ninth lens, a tenth lens, an eleventh lens, a twelfth lens, detector protection glass, a cold diaphragm and an image plane which are coaxially and sequentially arranged in the light propagation direction. The medium / long wave composite refrigeration infrared detector is mainly used for receiving inherent infrared radiation of a target and a background, converging the infrared radiation to a photosensitive surface of the medium / long wave composite refrigeration infrared detector, converting an optical signal into an electric signal through photoelectric conversion, realizing medium / long wave composite dual-band detection, reliably finding, identifying and positioning the target with weak infrared characteristics and strong concealment, and implementing accurate strike.

Description

Technical Field

[0001] The present invention belongs to the field of optical imaging technology, and in particular relates to a medium / long wave composite common aperture refrigeration infrared athermal optical system. Background Art

[0002] With the rapid development of optical detection and perception technology, cooled infrared imaging detection systems have broad application prospects in science and technology, security monitoring, national defense and military fields. This invention is based on a novel medium / long-wave composite infrared cooled detector with a high-resolution, small-pixel resolution of 640×512 and a pixel size of 20μm, with dual infrared bands of 3.7μm to 4.8μm and 7.7μm to 10.3μm. Taking into account the influence of factors such as the atmospheric transmission window, the detection object, and the operating environment, a medium / long-wave composite common-aperture cooled infrared athermalization optical system was designed. This system has excellent imaging quality within an operating temperature range of -40°C to +60°C, can operate 24 / 7, and has strong anti-interference capabilities, effectively utilizing the performance of the infrared imaging detection system and improving the system's environmental adaptability.

[0003] In summary, a medium / long-wave composite common-aperture cooled infrared athermalized optical system is proposed. Summary of the Invention

[0004] In view of this, the present invention aims to propose a medium / long wave composite co-aperture cooled infrared athermal optical system to achieve the problem of medium / long wave composite, co-aperture, athermal design of cooled infrared imaging detection system.

[0005] To achieve the above objectives, the present invention adopts the following technical solutions to provide a medium / long wavelength composite common aperture cooled infrared athermalized optical system, comprising:

[0006] A first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens, a ninth lens, a tenth lens, an eleventh lens, a twelfth lens, a detector protection glass, a cold stop and an image plane are coaxially arranged in sequence in the direction of light propagation.

[0007] Furthermore, the light incident side of the first lens is aspherical and the light emitting side is spherical; the light incident side of the ninth lens is aspherical and the light emitting side is spherical; and the remaining lenses are all spherical lenses.

[0008] Furthermore, the first lens, the fourth lens, the fifth lens, the sixth lens, the eighth lens, the ninth lens, and the twelfth lens are positive lenses; and the second lens, the third lens, the seventh lens, the tenth lens, and the eleventh lens are negative lenses.

[0009] Furthermore, the specific parameters of the optical system are shown in Table 1.

[0010] Table 1 Parameters of medium / long wave composite common aperture cooling infrared athermalization optical system

[0011]

[0012]

[0013] Beneficial effects:

[0014] 1. The optical system described in the present invention has an operating band of 3.7μm to 4.8μm and 7.7μm to 10.3μm, a focal length of 175mm, an F number of 2, a full field of view distortion of ≤3%, and a field of view of 4.1°×3.3°. The detector uses a Stirling dual-band cooled infrared detector with a resolution of 640×512 and a pixel size of 20μm. It is a small F number medium / long wave composite common aperture cooled infrared optical system with the characteristics of large relative aperture, high resolution, and medium / long wave composite common aperture.

[0015] 2. The transfer function of the optical system described in the present invention is ≥0.65 for medium-wave field of view and ≥0.6 for other fields of view at a Nyquist frequency of 25 lp / mm between -40°C and +60°C; ≥0.45 for long-wave field of view and ≥0.4 for other fields of view, with excellent imaging quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The accompanying drawings, which constitute part of the present invention, are provided to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are provided to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings:

[0017] Figure 1 This is a structural diagram of a high-resolution long-wavelength cooled infrared imaging guidance optical system;

[0018] Figure 2 It is the modulation transfer function curve at medium wave +60℃;

[0019] Figure 3 It is the modulation transfer function curve at medium wave +20℃;

[0020] Figure 4 This is the modulation transfer function curve at medium wave -40℃;

[0021] Figure 5 It is the modulation transfer function curve at long wave +60℃;

[0022] Figure 6 It is the modulation transfer function curve at long wave +20℃;

[0023] Figure 7 It is the modulation transfer function curve of long wave at -40℃;

[0024] Figure 8is the distortion grid curve of the medium wave optical system;

[0025] Figure 9 is the distortion grid curve of the long-wave optical system.

[0026] In the figure: first lens 1; second lens 2; third lens 3; fourth lens 4; fifth lens 5; sixth lens 6; seventh lens 7; eighth lens 8; ninth lens 9; tenth lens 10; eleventh lens 11; twelfth lens 12; detector protection glass 13; cold aperture stop 14; image plane 15. DETAILED DESCRIPTION

[0027] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely explain the technical solutions in the embodiments of the present invention. It should be noted that the embodiments of the present invention and the features therein can be combined with each other in the absence of conflict, and the embodiments described are only part of the embodiments of the present invention, not all of the embodiments.

[0028] It should be noted that the descriptions of the present invention regarding directions such as "left", "right", "left side", "right side", "upper", "lower", "top", and "bottom" are all defined based on the relationship between the orientations or positions shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the structure must be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on the present invention. In the description of the present invention, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0029] In the description of the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood broadly. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to direct connections, indirect connections through an intermediary, or internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0030] Referring to the accompanying drawings, this embodiment provides a medium / long wavelength composite common aperture cooled infrared athermalization optical system, comprising:

[0031] Coaxially arranged in the direction of light propagation are a first lens 1, a second lens 2, a third lens 3, a fourth lens 4, a fifth lens 5, a sixth lens 6, a seventh lens 7, an eighth lens 8, a ninth lens 9, a tenth lens 10, an eleventh lens 11, a twelfth lens 12, a detector protective glass 13, a cold stop 14, and an image plane 15. The optical system is used to receive infrared radiation inherent to the target and background and converge it onto the photosensitive surface of a medium / long-wave composite cooled infrared detector. Through photoelectric conversion, the optical signal is converted into an electrical signal, achieving medium / long-wave composite dual-band detection. This system can reliably detect, identify, and locate targets with weak infrared signatures and strong concealment, enabling precise strikes.

[0032] In this embodiment, the light incident side of the first lens 1 is aspherical and the light emitting side is spherical; the light incident side of the ninth lens 9 is aspherical and the light emitting side is spherical; and the remaining lenses are all spherical lenses.

[0033] In this embodiment, the first lens 1, the fourth lens 4, the fifth lens 5, the sixth lens 6, the eighth lens 8, the ninth lens 9, and the twelfth lens 12 are positive lenses; the second lens 2, the third lens 3, the seventh lens 7, the tenth lens 10, and the eleventh lens 11 are negative lenses.

[0034] In this embodiment, specific parameters of the optical system are shown in Table 1.

[0035] Table 1 Parameters of medium / long wave composite common aperture cooling infrared athermalization optical system

[0036]

[0037]

[0038] This technical solution defines the number, radius of curvature, thickness, spacing, semi-aperture, and material of each lens. To accommodate medium / long-wave composite common apertures and extremely harsh operating environments, the design utilizes a secondary imaging structure, rationally matching lens power, fully considering material properties, and applying advanced aberration theory to effectively balance the conflict between optical aberrations and thermal differences. This results in excellent imaging quality within the operating wavelength range of 3.7μm to 4.8μm and 7.7μm to 10.3μm, and within the operating temperature range of -40°C to +60°C. The system exhibits strong environmental adaptability, effectively leveraging the performance of the medium / long-wave composite infrared imaging detection system and enhancing its environmental adaptability.

[0039] The embodiments of the present invention disclosed above are intended only to illustrate the present invention. The embodiments do not describe all details in detail, nor do they limit the present invention to the specific embodiments described. Numerous modifications and variations are possible based on the contents of this specification. These embodiments are selected and described in detail in this specification to better explain the principles and practical applications of the present invention, thereby enabling those skilled in the art to better understand and utilize the present invention.

Claims

1. A medium / long wavelength composite common aperture cooled infrared athermalization optical system, characterized by: A first lens (1), a second lens (2), a third lens (3), a fourth lens (4), a fifth lens (5), a sixth lens (6), a seventh lens (7), an eighth lens (8), a ninth lens (9), a tenth lens (10), an eleventh lens (11), a twelfth lens (12), a detector protection glass (13), a cold stop (14) and an image plane (15) are coaxially arranged in sequence in the direction of light propagation.

2. The medium / long wavelength composite common aperture refrigerated infrared athermalization optical system according to claim 1, characterized in that: The light-entry side of the first lens (1) is an aspherical surface, and the light-exit side is a spherical surface; the light-entry side of the ninth lens (9) is an aspherical surface, and the light-exit side is a spherical surface; and the remaining lenses are all spherical lenses.

3. The medium / long wavelength composite common aperture refrigerated infrared athermalization optical system according to claim 2, characterized in that: The first lens (1), the fourth lens (4), the fifth lens (5), the sixth lens (6), the eighth lens (8), the ninth lens (9), and the twelfth lens (12) are positive lenses; the second lens (2), the third lens (3), the seventh lens (7), the tenth lens (10), and the eleventh lens (11) are negative lenses.

4. The medium / long wavelength composite common aperture refrigerated infrared athermalization optical system according to claim 3, characterized in that: The specific parameters of the optical system are shown in Table 1. Table 1 Parameters of medium / long wave composite common aperture cooling infrared athermalization optical system

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