CN201945744U

CN201945744U - Refraction type infrared optical system for supersonic guidance

Info

Publication number: CN201945744U
Application number: CN2010205359056U
Authority: CN
Inventors: 康为民; 张建隆
Original assignee: Harbin Institute of Technology
Current assignee: Beijing Simulation Center
Priority date: 2010-09-20
Filing date: 2010-09-20
Publication date: 2011-08-24
Anticipated expiration: 2020-09-20

Abstract

The utility model discloses a refraction type infrared optical system for supersonic guidance, which comprises a fairing, a first positive power meniscus lens, a second negative power meniscus lens, a third positive power meniscus lens, a fourth double convex lens, a fifth negative power meniscus lens, a sixth positive power meniscus lens, a Dewar flask window, a filter plate, a cold diaphragm and a detector array. The refraction type infrared optical system is characterized in that the entrance pupil position is designed at the fairing by using secondary imaging, so that incident light from different viewing fields enters an imaging system from the same position of the fairing, the optical system is subjected to the same interference from infrared backgrounds of different viewing fields in a pneumatic environment and the influence of the pneumatic heat radiation effect on the uniformity of a mirror surface is reduced. Meanwhile, the turbulent flow mixing layers of incidents light from different viewing fields, which pass through the surface of the fairing are the same, so that the pattern distortion due to the change of gas density gradients of the mixing layers under different viewing fields is reduced and the imaging quality is improved.

Description

A kind of refraction type infrared optical system that is used for the supersonic speed guidance

(1) technical field

The utility model relates to a kind of optical system, and more particularly, it relates to a kind of refraction type infrared optical system that is used for the supersonic speed guidance.

(2) background technology

Infrared optical system is the important component part in the infrared imaging guidance system, has a wide range of applications in military field.The infrared optical system of supersonic speed guidance causes optical system radome fairing and atmosphere that violent friction takes place owing to can produce very complicated flow perturbation around in the process of its high-speed flight, and the radome fairing temperature raises, and exists strong infrared background to disturb.In addition, under the disturbance of air-flow, the pneumatic optic transmission effects such as variation of flow field temperature, density can cause the variation and the fluctuation of medium refraction index on the target emanation travel path, and then cause that image planes are fuzzy, phenomenons such as shake, distortion, energy loss and position excursion, therefore can have a strong impact on the catching of target, target barycenter track and target shape, thereby reduce detection, tracking and the recognition capability of target seeker to target, influence the terminal guidance precision, can cause missile brain complete failure when serious.

For the Polaroid optical system of existing infrarefraction, owing to need 100% cold stop efficient, usually the cold stop of detector is made as the aperture diaphragm of system, so just, after can making the entrance pupil position be positioned at radome fairing, cause the incident light of different visual fields to enter in the imaging system along the diverse location of radome fairing.Because it is uneven that the temperature field of radome fairing under pneumatic environment of supersonic speed guidance distributes, is different so the infrared background that the different visual fields of optical system produce disturbs, thereby causes the optical system imaging homogeneity seriously to descend.Flow field index distribution because of radome fairing diverse location under the pneumatic environment also is uneven again, then cause the skew difference of light on the focal plane under the different visual fields, and then produce distortion and position excursion, thus influence the image quality of optical system.

(3) summary of the invention

Based on some problems that exist in the above-mentioned technology, the purpose of this utility model is to propose a kind of pneumatic heat radiation and pneumatic optic transmission effect of effectively alleviating, can be used in the refraction type infrared optical system of supersonic speed guidance, the system is characterized in that the mode of utilizing secondary imaging with the entrance pupil Position Design of optical system at the radome fairing place.

The utility model is realized by the following technical solutions:

Object space is finished earlier Polaroid by preceding group of lens group, and then organize lens group through the back, Dewar flask window, optical filter, cold stop finish secondary imaging and list in detector array.

Eyeglass in the lens combination can adopt different infra-red materials to come color difference eliminating, and adopts the aspheric surface design at suitable lens surface, in order to reduce system's eyeglass number, optimization system structure, improves image quality.Owing to adopted the mode of secondary imaging, can under the prerequisite that guarantees emergent pupil and detector cold stop coupling, the entrance pupil position be advanced to the radome fairing place, thereby satisfy 100% cold stop efficient of system.

The utility model has the advantages that:

1, adopted infrarefraction formula secondary imaging optical system, made the radome fairing bore can accomplish and the entrance pupil sizableness that the parasitic light that enters system is few.

2, the entrance pupil set positions is at the radome fairing place, make the incident light of different visual fields to enter from the same position of radome fairing the imaging system, so it is identical that the infrared background of optical system different visual fields under pneumatic environment disturbs, and has alleviated pneumatic thermoradiation efficiency to the inhomogeneity influence of image planes.Simultaneously, the incident light of different visual fields is identical through the turbulent mixing layer of cowling surface, has therefore reduced under the different visual fields because the pattern distortion that the variation of mixolimnion gas density gradient causes has improved image quality.

(4) description of drawings

Fig. 1 is the structural representation of the utility model refraction type infrared optical system;

Fig. 2 is the optical transfer function curve map of the utility model refraction type infrared optical system;

Fig. 3 is the point range figure of the utility model refraction type infrared optical system.

Among the figure: preceding group of lens group 1 radome fairing 2 lens 3 lens 4 lens 5 lens 6 lens 7 lens 8 Dewar flask windows 9 optical filters 10 cold stops 11 detector arrays 12 back group lens groups 13.

(5) specific embodiments

Below in conjunction with accompanying drawing and embodiment the utility model is described in further detail:

Among Fig. 1, the optical system object space is finished earlier Polaroid by preceding group of lens group 1, and then organize lens group 13 through the back, Dewar flask window 9, optical filter 10, cold stop 11 finish secondary imaging on detector array 12.Preceding group lens group 1 is by radome fairing 2, and positive light coke lens 3 and negative power lens 4 are formed, and radome fairing 2 adopts magnesium fluoride material cheaply, and lens 3 and lens 4 adopt meniscus lenses, and both all bend towards picture side.Back group lens group 13 is made up of four lens, wherein lens 5 are the positive light coke meniscus lens, bend towards object space, its effect is to make skew ray Shu Fasheng deviation, in order to reduce the diameter of optical system, lens 6 are lenticular lens, and lens 7 and lens 8 are for bending towards the meniscus shaped lens of object space, wherein lens 7 are the negative power lens, and lens 8 are the positive light coke lens.Lens 3 and lens 6 have adopted aspheric surface, in order to reduce the aberration in the system, improve image quality.For color difference eliminating, lens combination has adopted two kinds of different optical materials of germanium and silicon, and wherein lens 3, lens 5, lens 6 and lens 8 are silicon materials, and lens 4 and lens 7 are germanium material.Dewar flask window 9 is silicon materials, and optical filter 10 is a germanium material.Owing to need to consider 100% cold stop efficient, has good performance to guarantee detector array, with the cold stop 11 of detector aperture diaphragm as system.Utilize entrance pupil that optical design software guarantees optical system at the radome fairing place, and the optimization system parameter to be to guarantee image quality, the specific design parameter that finally obtains optical system is as shown in table 1.

Shown among Fig. 2 the utility model 0 ° of visual field, 4 ° of visual fields, 6 ° of visual fields, 9.6 ° of visual fields and 20 ° of visual fields to spatial frequency be 0～16 line right/the MTF curve of millimeter, the MTF under all visual fields is all greater than 0.72, near diffraction limit.

The point range figure that has shown 0 ° of visual field of the utility model, 4 ° of visual fields, 6 ° of visual fields, 9.6 ° of visual fields and 20 ° of visual fields among Fig. 3, the root-mean-square value of disc of confusion diameter is 11.352 μ m to the maximum, satisfies the single pixel dimension area of The common detector: the requirement of 301m * 30 μ m.

The technical indicator of native system is as follows: service band 3.7～4.8 μ m, and 20 ° of field angle, F is several 2, focal length 33.5mm, the entrance pupil position overlaps with the position of radome fairing substantially apart from radome fairing 0.016mm, has reached designing requirement.

Table 1 Design for optical system parameter

Claims

1. one kind is used for the refraction type infrared optical system that supersonic speed is guided, and it is characterized in that: described optical system is made up of preceding group of lens group (1), back group lens group (13), Dewar flask window (9), optical filter (10), cold stop (11) and detector array (12) to picture side successively from object space.

2. a kind of refraction type infrared optical system that is used for the supersonic speed guidance according to claim 1, it is characterized in that, group lens group (1) comprises radome fairing (2), positive light coke meniscus lens (3) and negative power meniscus lens (4) before described, and described back group lens group (13) comprises positive light coke meniscus lens (5), lenticular lens (6), negative power meniscus lens (7) and positive light coke meniscus lens (8); Positive light coke meniscus lens (3) and lenticular lens (6) have adopted the aspheric surface design; Positive light coke meniscus lens (3), positive light coke meniscus lens (5), lenticular lens (6) and positive light coke meniscus lens (8) are silicon materials, and negative power meniscus lens (4) and negative power meniscus lens (7) are germanium material.