CN105445930A - Front end optical-mechanical structure of night vision reconnaissance system fusing infrared light with micro light - Google Patents

Abstract

The invention discloses a front end optical-mechanical structure of a night vision reconnaissance system fusing infrared light with micro light. The front end optical-mechanical structure comprises a housing and a base. An infrared detector and a micro light image intensifier are fixed on the base. An infrared imaging device is composed of an infrared zooming objective lens and the infrared detector. A micro light imaging device is composed of a group of wedged glass, a micro light objective lens, the micro light image intensifier, a CCD and a CCD adjusting device. By changing relative positions of the group of wedged glass, an included anble between optical axes of an infrared optical system and a micro light optical system is changed, and the purpose of parallel optical axes is achieved. By rotating a zooming ring of the infrared zooming objective lens, the size of an infrared image is changed, and the CCD is controlled by the CCD adjusting device to rotate in a plane perpendicular to the optical axes, so that the rotation of the image is realized.

Description

The infrared night vision reconnaissance system front end optical-mechanic structure merged with low-light

Technical field

The present invention relates to the image registration field in image co-registration, particularly a kind of for the infrared front end optical-mechanic carrying out optical register with twilight image.

Technical background

In image co-registration field, image due to different sensors acquisition also exists the deviation on size and position, so needed to carry out registration to source images before carrying out image co-registration, namely with an interim width source images for benchmark, convergent-divergent is carried out to other source images, rotate and translation, make source images identical.

Image registration accuracy, for most important image co-registration, even if only have the deviation of a pixel, all can cause fused images ghost image, have a strong impact on the quality of fused images, make image co-registration lose the advantage of self.

The existing method for registering images of Pixel-level registration of multisensor is all, in front-end optical structure, the light path of all the sensors is adjusted to centered optical system or parallel shafts optical system, then by registration Algorithm, zooming and panning are carried out, to reach the object of registration to the image obtained on computers.Registration be divide into two parts by this method, complicated operation, and process on computers needs to take certain resource and time.Under resource and time-limited condition, the performance of reconnaissance system can be reduced.

Summary of the invention

The object of the present invention is to provide and a kind ofly can realize the infrared of high registration accuracy and the front end optical-mechanic structure of low-light emerging system, make the image of acquisition not need the registration in computing machine and can image co-registration be directly used in.

The technical solution realizing the object of the invention is: a kind of infrared night vision reconnaissance system front end optical-mechanic structure merged with low-light, comprises infrared varifocus objective, infrared eye, Weak light, gleam image intensifier, CCD, CCD regulating device, square shell and wedge; Infrared light hole and low-light light hole is had at the front surface of square shell, the diameter in hole is greater than the diameter of infrared varifocus objective and Weak light respectively, infrared light hole is aimed in infrared varifocus objective front, infrared varifocus objective rear end is connected with infrared eye, form infrared imaging system, Weak light [3] front end is placed wedge and is aimed at low-light light hole, Weak light rear end is connected with gleam image intensifier, CCD is met after gleam image intensifier, CCD is provided with CCD regulating device, forms Low Light Level Imaging System; Infrared imaging system and Low Light Level Imaging System are placed in parallel in square shell.

The present invention compared with prior art, its remarkable advantage: (1) this front end optical-mechanic structure is based on parallel optical axis design, thus avoid the attenuated optical signal problem in the half-reflecting half mirror manufacture craft of complexity required in common optical axis design and common optical axis design; (2) parallelism of optical axis is through Photoperiodic effects device proper calibration, optical axis included angle≤0.1mRad, and two detectors are to the visual field registration of target more than 99%; Utilize wedge to carry out light path fine setting to micro light detecting device, improve two detection systems further to the registration of target, from mechanical-optical setup for image registration provides guarantee; (3) achieve in light channel structure two detectors obtain image at size and the registration that rotates, for later stage work is got ready, operand when having saved image co-registration and computational space, improve the real-time of system when practical application.(4) this device is of moderate size, simple to operate, is easy to carry about with one.

Accompanying drawing explanation

Fig. 1 is parallel optical axis design drawing.

Fig. 2 is the uneven image of dual sensor optical axis (sensor angle α < 90 °).

Fig. 3 is the uneven image of dual sensor optical axis (sensor angle α > 90 °).

Fig. 4 is two wedge index paths.

Fig. 5 is zoom lens inner structure.

Fig. 6 is optical zoom schematic diagram.

Fig. 7 is this bright patent structure figure.

Fig. 8 is patent outside drawing of the present invention.

Fig. 9 is patent infrared light path figure of the present invention.

Figure 10 is patent low-light index path of the present invention.

Embodiment

Inventive principle

1. run-in index stereoscopic model

Infrared imaging system and Low Light Level Imaging System can regard the run-in index stereoscopic model in Binocular Stereo Vision System as, their optical axis is parallel to each other, and binocular vision system is based on principle of parallax and utilize imaging device to obtain by the data of altimetric image from diverse location.

According to existing condition, in front end optical-mechanic structure, have employed mistake! Do not find Reference source.Shown directional light shaft design, visual field θ (unit is mrad) can be obtained by formula, and f is here the focal length of Liar, and d is the distance of the length of side of imageing sensor, u target, two object lens centre distance b.

Visual field 2 θ (unit mrad) of object lens 1 can be tried to achieve by following formula:

$\mathrm{tg\&theta;}=\frac{d}{2f}---\left(1\right)$

Object distance infinity, when θ is very little, then has

$\mathrm{\&theta;}\&ap;\frac{d}{2f}---\left(2\right)$

The visual field of these two object lens does not overlap completely as seen from the figure, has the redundancy of b up and down respectively, and so their visual field registration can be expressed as:

$\begin{array}{c}\mathrm{\&epsiv;}=\frac{2\mathrm{u\&theta;}-b}{2\mathrm{u\&theta;}}\\ =1-\frac{b}{2\mathrm{u\&theta;}}\end{array}---\left(3\right)$

If order $\mathrm{\&Delta;}=\frac{b}{2\mathrm{u\&theta;}},$ Then (3) just become

ε＝1-Δ(4)

In formula, Δ is enough little, and so ε is just close to 1.

That is, if the centre distance of two object lens is enough little, the centre distance of relative two object lens of viewing distance is larger again, and so the registration of the visual field of two object lens is just infinitely close to 1, under these conditions, two visual fields can be regarded as and overlap completely, in actual applications, the value of u is general comparatively large, is generally a few to tens of km, and b is generally a few cm, substantially meet this condition.Actual test in, as long as visual field registration ε is greater than 99%, just can carry out the registration work of computer terminal.

If two optical axises are not parallel, sensor has certain angle α < 90 °, figure can find out that two visual fields overlap completely in certain distance, but there occurs change because imaging obtains angle, the image that two sensors obtain distorts, and what in follow-up fusion treatment, meeting was serious affects fusion mass.During α > 90 °, in Fig. 3, the visual field registration of two object lens is less, and along with the increase of distance can be more and more less, until do not overlap completely.

From discussion above, detector parallelism of optical axis is also the leading indicator affecting performance of front end, i.e. the optical axis included angle of two optical systems.According to visual field registration computing formula (3), obtain following correction formula:

$\begin{array}{c}\mathrm{\&epsiv;}=\frac{\mathrm{utg\&beta;}-b/2}{2\mathrm{utg\&theta;}}\\ \&ap;\frac{2\mathrm{utg\&beta;}-b}{4\mathrm{utg\&theta;}}\end{array}---\left(5\right)$

In formula, 2 β are angles of two image sensor optical axis.

Based on requirement visual field registration being greater than to 99%, the angle that can obtain two image sensor optical axis by (5.5) should be less than 0.5mRad, and the parallelism of optical axis allowable errors of low-light and infrared two cover optical systems are ± 0.5mRad.

2, wedge rotates optical axis principle

The very little prism in refraction angle is called wedge, and because refraction angle is very little, its angle of deviation formula can abbreviation be greatly:

δ＝(n-1)α

Namely angle of deviation is only decided by locking angle and Refractive Index of Material n.

As shown in Figure 4, two wedge refraction angle is α, a minim gap of being separated by, and when two wedge principal sections are parallel and when placing in the same way, the angle of deviation produced is maximum, is two wedge angle of deviation sums; When a wedge rotates 180 ° around optical axis, the angle of deviation produced is 0, and namely incident ray is parallel with emergent ray; When two wedges rotate relatively around optical axis, namely a wedge counterclockwise rotates angle, another wedge simultaneously clockwise direction rotates angle, total the angle of deviation δ that two wedges produce is with corner and become:

3, optical zoom principle

Variable focal length optical system refer to focal length can change in certain scope and in zooming procedure image planes position keep motionless, optical system that relative aperture is also substantially constant.Zoom lens can change focal length within the specific limits thus obtain the field angle of different size, the image of different size and different scenery scope.

The principle of varifocal optical system is that focal length continuously changes within the specific limits, and its image face keeps motionless.Total focal length of optical system is by the focal distance f of single lens (or lens combination) ₁', f ₂' ..., f _n' and lens (or lens combination)

d ₁,d ₂,…,d _k-1。In order to make focal length change, image planes are motionless, generally all utilize " image exchange principle ", even two conjugate pointss (object point and picture point) of object lens are all real point (or being all imaginary points), then can find two diverse locations of object lens, its conjugation is equal to each other.Reciprocal each other according to vertical enlargement formula its vertical imaging shaft multiplying power known.

In order to make object lens image planes in certain moving range all maintain static, need to arrange image planes offset lens group.General zoom lens inner structure can be as shown in Figure 5.

Below in conjunction with accompanying drawing, the present invention is described in further detail: a kind of infrared night vision reconnaissance system front end optical-mechanic structure merged with low-light of the present invention, comprises infrared varifocus objective 1, infrared eye 2, Weak light 3, gleam image intensifier 4, CCD6, CCD regulating device 7, square shell 10, wedge 14; Infrared light hole 12 and low-light light hole 13 is had at the front surface of square shell 10, the diameter in hole is greater than the diameter of infrared varifocus objective 1 and low-light varifocus objective 3 respectively, infrared light hole 12 is aimed in infrared varifocus objective 1 front, rear end is connected with infrared eye 2, form infrared imaging system, Weak light 3 front end is placed wedge 14 and is aimed at low-light light hole 13, rear end is connected with gleam image intensifier 4, CCD6 is met after gleam image intensifier 4, CCD6 is designed with CCD regulating device 7, forms Low Light Level Imaging System.

The optical axis of infrared varifocus objective 1 and Weak light 3 is positioned at same level plane, optical axis included angle≤0.1mRad; Infrared varifocus objective 1 and Weak light 3 have identical field of view angle, and infrared light hole 12 and low-light light hole 13 are positioned on the axis of two object lens.Wedge 14 length is consistent with object lens picture frame internal diameter.Infrared imaging system placement parallel with Low Light Level Imaging System, rear end is connected to the first transmission line 8 and the second transmission line 9, first transmission line can be connected outer computer with the second transmission line.

In infrared imaging system, scene forms optical imagery through infrared varifocus objective, and optical imagery is received by infrared eye and is converted to electric signal, is transferred to outer computer, forms digital picture by infrared video line.In Low Light Level Imaging System, scene forms optical imagery through Weak light, changes into electric signal and carry out image enhaucament to it through gleam image intensifier, then gathers through CCD, is transferred to outer computer by low-light video line.

In the present embodiment, square shell can add upper cover 11 as shown in Figure 8, above opens rectangular aperture, exposes the operation part of CCD regulating device, CCD can be made to rotate in perpendicular by stirring knob, thus the rotation of computer for controlling end image.Upper cover is connected with base by screw.Base there are two pieces of fixed heads playing fixation, are connected with base by screw, can dismantle.Infrared varifocus objective and Weak light aim at infrared light hole and low-light light hole respectively, are connected with base by fixed head.

During use, open infrared light path and low-light light path simultaneously, aim at scene to be collected, observe computer display end, regulate the zoom ring of zoom lens, make two-way image size identical; Regulate CCD regulating device, make the not skew in rotation of two-way image.

Like this, the infrared two-way image that receives with lll night vision reconnaissance system can directly enter Fusion Module and merges, and exports the image after merging, has greatly saved the Time and place of computing.

Claims (3)

1. the infrared night vision reconnaissance system front end optical-mechanic structure merged with low-light, is characterized in that: comprise infrared varifocus objective [1], infrared eye [2], Weak light [3], gleam image intensifier [4], CCD [6], CCD regulating device [7], square shell [10] and wedge [14], infrared light hole [12] and low-light light hole [13] is had at the front surface of square shell [10], the diameter in hole is greater than the diameter of infrared varifocus objective [1] and Weak light [3] respectively, infrared light hole [12] is aimed in infrared varifocus objective [1] front, infrared varifocus objective [1] rear end is connected with infrared eye [2], form infrared imaging system, Weak light [3] front end is placed wedge [14] and is aimed at low-light light hole [13], Weak light [3] rear end is connected with gleam image intensifier [4], CCD [6] is met after gleam image intensifier [4], CCD [6] is provided with CCD regulating device [7], form Low Light Level Imaging System, infrared imaging system and Low Light Level Imaging System are placed in parallel in square shell [10].

2. the infrared night vision reconnaissance system front end optical-mechanic structure merged with low-light according to claim 1, is characterized in that: the optical axis of infrared varifocus objective [1] and Weak light [3] is positioned at same level plane, optical axis included angle ; Infrared varifocus objective [1] and Weak light [3] have identical field of view angle, and infrared light hole [12] and low-light light hole [13] are positioned on the axis of two object lens, and wedge [14] length is consistent with object lens picture frame internal diameter.

3. the infrared night vision reconnaissance system front end optical-mechanic structure merged with low-light according to claim 1, it is characterized in that: infrared imaging system and Low Light Level Imaging System rear end are connected to the first transmission line [8] and the second transmission line [9], the first transmission line [8] and the second transmission line [9] are for being connected outer computer.