CN104932083A - Large-area array dynamic monitoring and measuring camera optical system - Google Patents

Abstract

The invention relates to a large-area array dynamic monitoring and measuring camera optical system. The large-area array dynamic monitoring and measuring camera optical system is composed of anti-radiation window glass, 12 spherical lenses and a large-area array receiver; surveying and mapping target radiation beams which fully fill the entrance pupil of the optical system enters the optical system through an anti-radiation window; and an approximate telecentric optical path inverted telephoto structure is adopted to obtain low-distortion and high-illumination image information at a focal plane. According to the invention, the approximate telecentric optical system is adopted, namely, the emergent main light ray angles of fields of view are approximately parallel, and gamma is approximately equal to 0.1; a designed transfer function can achieve diffraction limits, and at the same time, can satisfy requirements for low distortion and high illumination. The large-area array dynamic-monitoring measuring camera optical system of the invention has the advantages of wide angle, being approximately telecentric, low distortion, excellent relative illumination, high engineering feasibility, high integration degree of an optical machine structure, excellent temperature adaptability and the like. The focal power of four lens groups is reasonably optimized, so that large-format, high-resolution and image plane-uniform imaging of a target scene can be realized.

Description

A kind of large face battle array dynamic monitor and measurement camera optical system

Technical field

The invention belongs to space optical remote sensor technical field, relate to a kind of implementation method of face battle array wide-angle surveillance camera optics imaging system under transmission-type, Large visual angle, the approximate heart far away, high relative exposure, low distortion and high imaging quality condition being applied to space.

Background technology

Flake imaging optical system is a kind of optical system of Large visual angle imaging, can obtain the scene domain that common lens is incomparable, and its application expands to the fields such as space flight deep space background detection process supervision gradually from special photograph field.

According to Aberration Theory, the distortion of optical system is the aberration relevant with visual field, and the relative exposure of image planes is then biquadratic relation with peripheral field chief ray incident to the angle cosine value of image planes, to general optical system, angle enlargement ratio is little, therefore, flake imaging system usually has larger distortion and lower relative exposure, greatly reduces image quality and the signal to noise ratio (S/N ratio) of system.

As far back as eighties of last century twenties, R.W.Wood has just started the research to flake imaging system, and from the sixties in last century, fish eye lens obtains unprecedented development at a high speed, has occurred many novelties and high-quality camera lens.Wherein NIKON design 180 °, a kind of visual field, F/2.8, focal length 16mm fish eye lens photography industry be widely applied.

The fish eye lens of successful Application mostly is civil area at present, and picture element requires relatively low, and environment for use, also without special character, there is no the flake imaging system successfully applied in-orbit.

Summary of the invention

The technical matters that the present invention solves is: overcome the deficiencies in the prior art, provide a kind of large face battle array dynamic monitor and measurement camera optical system, solve the difficult problem that the transmission-type of the face battle array wide-angle surveillance camera being applied to space, Large visual angle, the approximate heart far away, high relative exposure, low distortion and high imaging quality realize simultaneously.

Technical scheme of the present invention is: a kind of large face battle array dynamic monitor and measurement camera optical system, comprises the first lens combination, the second lens combination, the 3rd lens combination, the 4th lens combination, large face battle array focal plane detector part; The target emanation light beam being full of entrance pupil enters optical system, through the first lens combination and second group of lens combination adjustment aim radiation laser beam bore, target emanation light beam is made to be full of the diaphragm after being positioned over second group of lens combination, from the target emanation light beam of diaphragm outgoing after three lens cluster group and the 4th group of lens combination, adjustment System angle enlargement ratio Γ to 0.2, wherein Γ=ω ₂/ ω ₁, ω ₁for optical system edge chief ray incident angle, ω ₂for optical system edge chief ray incident is to the angle on the battle array focal plane detector part of large face, finally in the battle array focal plane detector part imaging of large face.

Described first lens combination comprises a slice aspheric surface bent moon negative lens, a slice aspheric surface bent moon negative lens and a slice sphere bent moon positive lens, and wherein the material of aspheric surface bent moon negative lens is crown glass, and the material of aspheric surface bent moon negative lens is flint glass.

Described second lens combination comprises a slice sphere bent moon positive lens, a slice sphere bent moon negative lens and a slice sphere bent moon negative lens, and wherein the material of sphere bent moon positive lens is crown glass, and the material of sphere bent moon negative lens is flint glass.

Described 3rd lens combination comprises a slice sphere biconvex positive lens, a slice sphere bent moon positive lens and two panels sphere bent moon negative lens, wherein the material of sphere biconvex positive lens is crown glass, and the material of sphere bent moon positive lens and sphere bent moon negative lens is flint glass.

Described 4th lens combination comprises two panels biconvex positive lens, and wherein the material of a slice biconvex positive lens is crown glass, and another sheet material is flint glass.

The present invention's advantage is compared with prior art:

1) the present invention's large battle array monitors camera telecentric optical system, visual field reaches 130 °, by control system angle enlargement ratio, solve that the intrinsic second order spectrum of money spectral coverage wide-angle transmissive system is difficult to eliminate, the little relative distortion of peripheral field and image planes height relative exposure are difficult to the difficult problem that simultaneously obtains; Optical system is only made up of 12 lens, can frame up respectively for first group, second group, the 3rd group and the 4th group of lens, the complexity reducing system processing and debug; Each mirror group barycenter is evenly distributed, and system stability is high.

2) optical system of the present invention adopts the sub-symmetrical structure pattern of the heart approximate far away, by accurately controlling the angle of each field of view edge chief ray incident to image planes, realize low distortion and high image planes relative exposure simultaneously, edge chief ray incident is compressed to 13o to the angle of image planes by 65o, enlargement ratio Γ=0.2, optical system angle, barycenter is stablized, reduce the impact of climate change on laboratory measurement precision, time in orbit, the trace change of focal plane can not affect the processing accuracy of data, focal plane change can not cause the change of each visual field disc of confusion barycenter thus improve the precision of control survey.

3) optical system of the present invention adopts anti-long distance transmission-type version to optimize the distance of last a slice lens arrangement to focal plane structure, thus reduces the difficulty of system assembling and adjustment.

4) optical system of the present invention to be disappeared thermal design and system global optimization by PASSIVE OPTICAL, according to the thermal expansivity of optical system lens barrel structure material, when making temperature variation, the change in location trend of optical system image planes is consistent with camera image planes detector position variation tendency, and when making optical system temperature variation ± 30 DEG C, picture element is stablized.

5) the present invention have mechanical-optical setup compact, form simple, low distortion, image quality is good, relative exposure is high, be easy to the advantages such as realization, by adopting detector pixel to merge the different resolution imaging realizing monitoring process while changing matter distance, the high-quality imaging system that short focus becomes object distance Large visual angle can be applied.For airborne/spaceborne Large visual angle in-orbit monitors that imaging optical system proposes a good technology realization means.

Accompanying drawing explanation

Fig. 1 is optical system of the present invention composition structural representation.

Fig. 2 is optical system transfer function curve.

Fig. 3 is optical system residual aberration and distortion curve.

Fig. 4 is the biography letter curve of optical system works temperature variation ± 30 DEG C

Embodiment

As shown in Figure 1, optical system of the present invention adopts anti-long distance transmission-type structure, comprise the first lens combination 1, second lens combination 2, the 3rd lens combination 3, the 4th lens combination 4, face battle array focal plane device 5, diaphragm 6 be positioned over the second lens combination and between the 3rd mirror group, form sub-symmetrical structure pattern; The mapping target emanation light beam being full of optical system entrance pupil enters optical system through anti-irradiation window, adjust beam size through front group of lens combination 1 and the second lens combination 2 and be full of diaphragm 6, after through the 3rd lens combination 3 and the 4th lens combination 4 adjustment System angle enlargement ratio, thus control both optical systematical distortion and image planes relative exposure, edge chief ray incident is compressed to 13o by 65o, finally in face battle array focal plane device 5 imaging to the angle of image planes.Lensed material is colouless optical glass, and the plated surface anti-reflection film that all lens contact with air, for increasing the energy efficiency of wide spectrum imaging optical system.Relative position and the clear aperture of diaphragm and lens combination is ensured by structural design loop configuration.

An embodiment of optical system of the present invention is focal length 5mm, operating spectrum band is visible spectrum 420 ~ 700nm, based on the requirement of camera system energy and signal to noise ratio (S/N ratio), optical system relative aperture elects 1/4 as, apparent field is 131 ° of optical system physical dimension is Φ 65mm × 90mm, the maximum clear aperture of lens combination controls within 65mm, lens combination length 85mm.As shown in Figure 3, system relative distortion is less than 5% in full filed.Camera uses the Using Plane Array CCD Device of 8 μm, by plating the effective spectral coverage scope of bandpass filters control system in second, detector window glass.

In order to meet the particular/special requirement of the large working temperature field of optical system, the optical system focal power coupling met in formula (1) requires, the heat that disappears difference requires and the axial chromatic aberration that disappears requires:

$\left\{\begin{array}{c}\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{h}_i{\mathrm{\φ}}_i=h_1\mathrm{\φ}\\ d{f}_b^{\left(\mathrm{\λ}\right)}/\mathrm{dT}=\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{h}_i^2{T}_{f,\mathrm{ri}}{\mathrm{\φ}}_i+{\mathrm{\α}}_l\mathrm{\φ}=0\\ d{f}_b^{\left(\mathrm{\λ}\right)}=\underset{i=1}{\overset{n}{\mathrm{\Σ}}}\frac{h_i^2{\mathrm{\φ}}_i}{{\mathrm{\υ}}_i}=0\end{array}\right.---\left(1\right)$

In formula: h _ifor normalization first paraxial rays is at the height of each element, Φ _ifor the focal power of each element group of normalization, Φ is the focal power of normalization system, υ _ifor the Abbe number of each optical element, T _{f, ri}for thermal expansivity.

Optical system of the present invention is altogether made up of ten optical elements, and wherein window glass material and prism do not participate in imaging, and optical system is made up of eight lens, i.e. i=1,2.....12, h ₁... .h ₁₂represent the Penetration height of the first paraxial rays on the first to the 8th lens, Φ ₁... Φ ₁₂represent the normalized first to the 8th power of lens, Φ is the total focal power of optical system, υ ₁... υ ₁₂represent the Abbe number of first to the 8th lens.

The thermal expansivity of optical material can be expressed as:

$T_{f,r}=\frac{1}{f}\frac{\mathrm{df}}{\mathrm{dT}}={\mathrm{\α}}_g-\frac{\mathrm{\β}}{n-1}---\left(2\right)$

By formula (1) and (2), utilize the complementarity of the thermal characteristic parameter between multiple optical material and structured material, choose reasonable optical material also distributes the focal power of each lens combination, the thermal expansivity of optical system lens barrel structure material, when making temperature variation, the change in location trend of optical system image planes is consistent with camera image planes detector position variation tendency, and the position of optical system image planes and the difference of camera image planes detector position are less than the depth of focus of optical system.

Optical system is altogether made up of 12 lens, all adopts colouless optical glass.First lens combination 1 includes a slice aspheric surface bent moon negative lens, a slice aspheric surface bent moon negative lens and a slice sphere bent moon positive lens, wherein two blocks of crown glasses, and one piece is flint glass; Second lens combination 2 comprises a slice sphere bent moon positive lens, a slice sphere bent moon negative lens and a slice sphere bent moon negative lens, wherein one block of crown glass, two pieces be flint glass; 3rd lens combination 3 includes a slice sphere biconvex positive lens, a slice aspheric surface bent moon positive lens and two panels sphere bent moon negative lens, wherein two blocks of crown glasses, two pieces be flint glass; 4th lens combination 4 includes two panels biconvex positive lens, wherein one block of crown glass, one block of flint glass.The optical material that 12 lens adopt is high chemical stability, low thermal expansion factor.

As shown in Figure 2 and Figure 4, the biography letter curve of optical system in normal temperature 20 DEG C and temperature variation ± 30 DEG C is substantially unchanged.Fig. 3 gives Optical System Design residual phase to distortion curve, and full filed relative distortion is less than 3.6%.

Large face battle array focal plane detector part 5 is area array CCD or cmos detector receiving plane.

The content be not described in detail in instructions of the present invention belongs to the known technology of those skilled in the art.

Claims (5)

1. a large face battle array dynamic monitor and measurement camera optical system, is characterized in that: comprise the first lens combination (1), the second lens combination (2), the 3rd lens combination (3), the 4th lens combination (4), large face battle array focal plane detector part (5); The target emanation light beam being full of entrance pupil enters optical system, through the first lens combination (1) and second group of lens combination (2) adjustment aim radiation laser beam bore, target emanation light beam is full of be positioned over the diaphragm (6) after second group of lens combination (2), from the target emanation light beam of diaphragm (6) outgoing after three lens cluster group (3) and the 4th group of lens combination (4), adjustment System angle enlargement ratio to 0.2, wherein ω ₁for optical system edge chief ray incident angle, ω ₂for optical system edge chief ray incident is to the angle on large face battle array focal plane detector part (5), finally in battle array focal plane detector part (5) imaging of large face.

2. one according to claim 1 large face battle array dynamic monitor and measurement camera optical system, it is characterized in that: described first lens combination (1) comprises a slice aspheric surface bent moon negative lens, a slice aspheric surface bent moon negative lens and a slice sphere bent moon positive lens, wherein the material of aspheric surface bent moon negative lens is crown glass, and the material of aspheric surface bent moon negative lens is flint glass.

3. one according to claim 1 large face battle array dynamic monitor and measurement camera optical system, it is characterized in that: described second lens combination (2) comprises a slice sphere bent moon positive lens, a slice sphere bent moon negative lens and a slice sphere bent moon negative lens, wherein the material of sphere bent moon positive lens is crown glass, and the material of sphere bent moon negative lens is flint glass.

4. one according to claim 1 large face battle array dynamic monitor and measurement camera optical system, it is characterized in that: described 3rd lens combination (3) comprises a slice sphere biconvex positive lens, a slice sphere bent moon positive lens and two panels sphere bent moon negative lens, wherein the material of sphere biconvex positive lens is crown glass, and the material of sphere bent moon positive lens and sphere bent moon negative lens is flint glass.

5. one according to claim 1 large face battle array dynamic monitor and measurement camera optical system, it is characterized in that: described 4th lens combination (4) comprises two panels biconvex positive lens, wherein the material of a slice biconvex positive lens is crown glass, and another sheet material is flint glass.