CN102645729B - Infrared optical system - Google Patents

Abstract

The invention discloses an infrared optical system, which is mounted on a photoelectric platform provided with an infrared focal plane detector and comprises a first lens system, a second lens system, a fly-back mirror and a third lens system. The fly-back mirror is positioned between the second lens system and the third lens system, both the first lens system and the second lens system have positive focal power, an image-side focal point F1 of the first lens system is coincided with an object-side focal point F2 of the second lens system, the first lens system and the second lens system form an infrared afocal system, and the fly-back mirror rotates around a self rotating shaft and realizes fly-back periodically. The infrared optical system receives the same scene information at infinity in integral time or at every moment within characteristic time, and a scene corresponding to the scene information is imaged on the infrared focal plane detector by the third lens system. The infrared optical system can solve the problem of image blurring when a photoelectric platform rotates at a fast speed, and has the advantages of small size, light weight, low cost and the like.

Description

A kind of infrared optical system

Technical field

The present invention relates to optical technical field, particularly relate to a kind of infrared optical system.

Background technology

Along with the development of infrared eye technology, infrared eye enters the focal plane epoch.Due to infrared focal plane device does not need scanning mechanism just can be to the direct staring imaging of scenery, and adopt the system architecture of focal plane device simple, volume is little, therefore, in every field, is widely used.In order to make infrared camera obtain higher sensitivity, the integral time of focal plane device or time constant are generally longer.Integral time or time constant are similar to the aperture time of Visible Light Camera, and still, when parameter detector, fixedly the time, integral time or time constant setting range are limited.

In order effectively in the time, to obtain larger hunting zone, the angular velocity of rotation of photoelectric platform (or turntable) is more and more faster, and 360 ° of panoramas are spliced by the multiple image with certain visual field.For the ease of the splicing of image, between two width images, have certain overlapping.

Photoelectric platform searching moving fast causes scenery and infrared system to relatively move fast between the two, and longer integral time or time constant cause infrared image fuzzy, has reduced sensitivity and the resolution of infrared camera, and having limited it should have field.

Summary of the invention

The technical problem to be solved in the present invention is to provide a kind of infrared optical system, in order to solve image blurring problem in prior art photoelectric platform fast rotational.

For solving the problems of the technologies described above, on the one hand, the invention provides a kind of infrared optical system, described infrared optical system is arranged on the photoelectric platform that adopts infrared focal plane detector; Described infrared optical system comprises first lens group, the second lens combination, flyback mirror and the 3rd lens combination; Wherein, described flyback mirror is between described the second lens combination and the 3rd lens combination; Described first lens group, the second lens combination all have positive light coke; And the rear focus F1 of described first lens group overlaps with the focus in object space F2 of the second lens combination; Described first lens group, the second lens combination form infrared afocal system; Described flyback mirror is around self turning axle rotation, cycle flyback; Each in integral time or time constant of described infrared optical system constantly all receives and is positioned at the Same Scene information of infinity, and by described the 3rd lens combination, the infrared radiation of this scene is imaged in to infrared focal plane detector.

Further, the equation of motion of described flyback mirror cycle flyback is:

$\mathrm{\&delta;}\left(t\right)=Z0+\frac{\mathrm{<figure-callout\; id="1"\; label="f"\; filenames="HDA0000156515240000021.png"\; state="\{\{state\}\}">f</figure-callout>}1}{2f2}\{{\&Integral;}_0^t\mathrm{\&omega;}\left(t\right)\mathrm{dt}-\mathrm{INT}[\frac{360{\&Integral;}_0^t\mathrm{\&omega;}\left(t\right)\mathrm{dt}}{n(1-\mathrm{\&beta;})}\left]\frac{{\&Integral;}_0^t\mathrm{\&omega;}\left(t\right)\mathrm{dt}}{1000}\right\};$

Wherein, when δ (t) the expression time is t, the position of flyback mirror, mean with angle; The zero position that Z0 is the flyback mirror; T is the time; The focal length that f1 is the first lens group; The focal length that f2 is the second lens combination; The function that ω (t) is photoelectric platform angular velocity of rotation and time t; The integral time that τ is infrared focal plane detector or time constant; N is the scene number that the spliced panoramic image needs; β is the scene Duplication; INT is bracket function.

Further, when photoelectric platform at the uniform velocity rotates with angular velocity omega, the equation of motion of flyback mirror cycle flyback is:

$\mathrm{\&delta;}\left(t\right)=Z0+\frac{\mathrm{<figure-callout\; id="1"\; label="f"\; filenames="HDA0000156515240000021.png"\; state="\{\{state\}\}">f</figure-callout>}1}{2f2}\{\mathrm{\&omega;t}-\mathrm{INT}[\frac{360\mathrm{\&omega;t}}{n(1-\mathrm{\&beta;})}\left]\frac{\text{\&omega;\&tau;}}{1000}\right\}.$

Further, described flyback mirror is positioned at the exit pupil position of infrared afocal system, and the entrance pupil position of described infrared afocal system is positioned on described first lens group.

Further, the entrance pupil position of described the 3rd lens combination overlaps with the exit pupil position of described infrared afocal system.

Further, there is intermediate image face in described the 3rd lens combination, or does not have intermediate image face.

Further, the exit pupil position of described the 3rd lens combination overlaps with the cold stop of infrared focal plane detector.

Further, there is the catoptron with turnover light path in described the 3rd lens combination; Described flyback mirror is also for the light path of turning back.

Further, described infrared optical system is applicable to non-refrigeration type or refrigeration mode infrared focal plane detector.

Further, described infrared optical system is applicable to shortwave, medium wave or LONG WAVE INFRARED focus planardetector.

Beneficial effect of the present invention is as follows:

Flyback mirror fast cycle of the present invention flyback, make infrared camera stare all the time Same Scene in whole integral time or time constant, solves image blurring problem in the photoelectric platform fast rotational; The flyback mirror is placed in the optics exit pupil position of infrared afocal system, makes its size minimum, and weight is the lightest, is convenient to servocontrol; The optics entrance pupil position of infrared afocal system is positioned on the first lens group, reduces infrared camera in the size perpendicular to optical axis direction, reduces the aperture amount aberration of optical system, dwindles its volume, reduces its cost; Flyback mirror and catoptron are turned back to light path, are convenient to the miniaturization of infrared camera.

The accompanying drawing explanation

Fig. 1 is the optical schematic diagram of the infrared optical system during photoelectric platform zero-bit in the embodiment of the present invention;

The optical schematic diagram of a certain position after the photoelectric platform of Fig. 2 Fig. 1 rotates;

Fig. 3 is the infrared optical system schematic diagram of the embodiment of the present invention 1 in the photoelectric platform zero-bit;

Fig. 4 is the infrared optical system schematic diagram of the embodiment of the present invention 1 a certain position after photoelectric platform rotates;

Fig. 5 is that the embodiment of the present invention 2 is learned the schematic diagram of system small field of view state at the ruddiness of photoelectric platform zero-bit;

Fig. 6 is the schematic diagram that the ruddiness of the embodiment of the present invention 2 a certain position after photoelectric platform rotates is learned system small field of view state;

Fig. 7 is that the embodiment of the present invention 2 is learned the schematic diagram of the large visual field of system state at the ruddiness of photoelectric platform zero-bit;

Fig. 8 is the schematic diagram that the ruddiness of the embodiment of the present invention 2 a certain position after photoelectric platform rotates is learned the large visual field of system state.

Embodiment

In order to solve image blurring problem in prior art photoelectric platform fast rotational, the invention provides a kind of infrared optical system, below in conjunction with accompanying drawing and embodiment, the present invention is further elaborated.Should be appreciated that specific embodiment described herein, only in order to explain the present invention, does not limit the present invention.

As shown in Figure 1, the embodiment of the present invention relates to a kind of infrared optical system, and this infrared optical system is arranged on the fast search photoelectric platform 7 that adopts infrared focal plane detector, to promote the fast search ability of the photoelectric platform that adopts infrared focal plane detector.This infrared optical system comprises first lens group 1, the second lens combination 2, flyback mirror 3, the 3rd lens combination 4, and flyback mirror 2 is between the second lens combination 2 and the 3rd lens combination 4; First lens group 1, the second lens combination 2 all have positive light coke.Focal power is the inverse of focal length, and positive light coke is exactly the inverse of positive focal length, and positive light coke shows it is positive lens.The rear focus F1 of first lens group 1 overlaps with the focus in object space F2 of the second lens combination 2, forms infrared afocal system 8.Infrared afocal system refers to the system of directional light incident, parallel light emergence, is equivalent to telescope.Flyback mirror 3 is positioned at the exit pupil position of infrared afocal system 8; The entrance pupil position of infrared afocal system 8 is positioned on first lens group 1; The 3 fast cycle flybacks of flyback mirror, each in integral time or time constant of infrared optical system constantly all receives and is positioned at the Same Scene information of infinity, and by the 3rd lens combination 4, the infrared radiation of this scene is imaged in to infrared focal plane detector; Flyback mirror 3 is around self turning axle rotation; Turning axle just is perpendicular to the straight line of flyback mirror 3 mid points; In Fig. 1, turning axle is exactly perpendicular to the straight line of paper on the mid point of flyback mirror 3.The entrance pupil position of the 3rd lens combination 4 overlaps with the exit pupil position of infrared afocal system 8, and the exit pupil position of the 3rd lens combination 4 overlaps with the cold stop of infrared focal plane detector.Can there be intermediate image face in the 3rd lens combination 4, also can have intermediate image face; There is the catoptron with turnover light path in the 3rd lens combination 4.

As shown in Figure 2, while rotating to position B (position shown in Fig. 2) process from zero-bit when photoelectric platform 7, utilize the flyback effect of flyback mirror 3, each in integral time or time constant constantly, optical system all receives Same Scene 5 information that are positioned at infinity, and by lens combination 4, the infrared radiation of scene 5 is imaged in to infrared focal plane detector 6.Flyback mirror 3 plays the effect of the light path of turning back.

The equation of motion of flyback mirror 3 fast cycle flybacks is:

$\mathrm{\&delta;}\left(t\right)=Z0+\frac{\mathrm{<figure-callout\; id="1"\; label="f"\; filenames="HDA0000156515240000021.png"\; state="\{\{state\}\}">f</figure-callout>}1}{2f2}\{{\&Integral;}_0^t\mathrm{\&omega;}\left(t\right)\mathrm{dt}-\mathrm{INT}[\frac{360{\&Integral;}_0^t\mathrm{\&omega;}\left(t\right)\mathrm{dt}}{n(1-\mathrm{\&beta;})}\left]\frac{{\&Integral;}_0^t\mathrm{\&omega;}\left(t\right)\mathrm{dt}}{1000}\right\};$

Wherein, when δ (t) the expression time is t, the position of flyback mirror 3, mean with angle; The zero position that Z0 is flyback mirror 3; T is the time; The focal length that f1 is the first lens group; The focal length that f2 is the second lens combination; The function that ω (t) is photoelectric platform angular velocity of rotation and time; The integral time that τ is infrared focal plane detector or time constant; N is the scene number that the spliced panoramic image needs; β is the scene Duplication; INT is bracket function.

When photoelectric platform at the uniform velocity rotates with angular velocity omega, the equation of motion of flyback mirror fast cycle flyback is:

$\mathrm{\&delta;}\left(t\right)=Z0+\frac{\mathrm{<figure-callout\; id="1"\; label="f"\; filenames="HDA0000156515240000021.png"\; state="\{\{state\}\}">f</figure-callout>}1}{2f2}\{\mathrm{\&omega;t}-\mathrm{INT}[\frac{360\mathrm{\&omega;t}}{n(1-\mathrm{\&beta;})}\left]\frac{\text{\&omega;\&tau;}}{1000}\right\}.$

Above-mentioned infrared optical system is monoscopic or many visual fields system, belongs to optics continuous vari-focus system, is applicable to non-refrigeration type or refrigeration mode infrared focal plane detector, also is applicable to shortwave, medium wave or LONG WAVE INFRARED focus planardetector.

Below with two instantiations, be elaborated:

Embodiment 1

Embodiment 1 is the infrared optical system that is applicable to the fast search photoelectric platform 7 of non-refrigeration type focal plane infrared eye.The infrared optical system schematic diagram that Fig. 3 is the photoelectric platform zero-bit, the infrared optical system schematic diagram that Fig. 4 is the embodiment of the present invention 1 a certain position after photoelectric platform rotates.Lens combination (first lens group) 1 is comprised of lens 301,302, lens combination (the second lens combination) 2 is comprised of lens 303,304, the rear focus F1 of lens combination 1 overlaps with the focus in object space F2 of lens combination 2, and lens combination 1,2 forms infrared afocal system 8; Flyback mirror 3 is positioned at infrared afocal system emergent pupil; Infrared afocal system 8 entrance pupil positions are positioned on lens 301; Lens combination (the 3rd lens combination) 4 is comprised of lens 305,306,307, and the entrance pupil position of lens combination 4 overlaps with the exit pupil position of infrared afocal system 8.The 3 fast cycle flybacks of flyback mirror, each in integral time or time constant of infrared optical system constantly all receives and is positioned at Same Scene 5 information of infinity, and by lens combination 4, the infrared radiation of this scene is imaged on infrared focal plane detector 6.Flyback mirror 3 plays the effect of the light path of turning back simultaneously.The technical indicator of this embodiment is in Table one.

Table one

Service band	8μm～14μm
		The F number	0.9
Focal length	150mm
		Visual field	6°×4.5°
The maximum flyback angle of flyback mirror	3.6°
		Integral time (or time constant)	10ms
The scene Duplication	8.3％

Scene is counted n	65
		Lens combination 1 focal distance f 1	254mm
Lens combination 2 focal distance f 2	60mm

When photoelectric platform 7 at the uniform velocity rotates with angular velocity omega, the equation of motion of flyback mirror fast cycle flyback is:

$\mathrm{\&delta;}\left(t\right)=Z0+\frac{\mathrm{<figure-callout\; id="1"\; label="f"\; filenames="HDA0000156515240000021.png"\; state="\{\{state\}\}">f</figure-callout>}1}{2f2}\{\mathrm{\&omega;t}-\mathrm{INT}[\frac{360\mathrm{\&omega;t}}{n(1-\mathrm{\&beta;})}\left]\frac{\mathrm{\&omega;\&tau;}}{1000}\right\};$

Bring the parameter in table one into above-mentioned equation, can obtain in this embodiment 1, the equation of motion of flyback mirror 3 fast cycle flybacks is:

$\mathrm{\&delta;}\left(t\right)=Z0+2\mathrm{\&omega;t}+\mathrm{INT}\left(6\mathrm{\&omega;t}\right)\frac{\mathrm{\&omega;}}{50}.$

Embodiment 2

Embodiment 2 is the infrared optical system of the fast search photoelectric platform of the infrared infrared eye in employing refrigeration mode focal plane, and this infrared optical system is the double-view field system.Fig. 5, Fig. 6 be under this example small field of view state in integral time or time constant, the infrared optical system schematic diagram of photoelectric platform different rotary position, lens combination (first lens group) 1 is comprised of lens 501,502,503, lens combination (the second lens combination) 2 is comprised of lens 504, the rear focus F1 of lens combination 1 overlaps with the focus in object space F2 of lens combination 2, and lens combination 1,2 forms infrared afocal system 8; Flyback mirror 3 is positioned at infrared afocal system 8 exit pupil positions; Lens combination (the 3rd lens combination) 4 is comprised of lens 505,506,507,508 and catoptron 509; 510 windows that are the refrigeration mode infrared focal plane detector, 511 is the cold stop in the refrigeration mode infrared focal plane detector; Have intermediate image point I in lens combination 4, there is conjugate relation in cold stop 511 with infrared afocal system 8 emergent pupils.Fig. 7, Fig. 8 be under the state of the large visual field of this example in integral time or time constant, the infrared optical system schematic diagram of photoelectric platform different rotary position.Under the small field of view state, cut lens 712,713, form the large visual field state of this example.The 3 fast cycle flybacks of flyback mirror, each in integral time or time constant of infrared optical system constantly all receives and is positioned at Same Scene 5 information of infinity, and by lens combination 4, the infrared radiation of this scene is imaged on infrared focal plane detector 6.The effect that flyback mirror 3 and catoptron 509 have light path to turn back.The technical indicator of this embodiment 2 is in Table two.

Table two

When photoelectric platform 7 at the uniform velocity rotates with angular velocity omega, the equation of motion of flyback mirror fast cycle flyback is:

$\mathrm{\&delta;}\left(t\right)=Z0+\frac{\mathrm{<figure-callout\; id="1"\; label="f"\; filenames="HDA0000156515240000021.png"\; state="\{\{state\}\}">f</figure-callout>}1}{2f2}\{\mathrm{\&omega;t}-\mathrm{INT}[\frac{360\mathrm{\&omega;t}}{n(1-\mathrm{\&beta;})}\left]\frac{\mathrm{\&omega;t}}{1000}\right\};$

Bring the parameter in table two into above-mentioned equation, can obtain respectively in this embodiment 2:

Under the small field of view state, the equation of motion of flyback mirror 3 is:

$\mathrm{\&delta;}\left(t\right)=z0+4.17\mathrm{\&omega;t}-\mathrm{INT}\left(3.05\mathrm{\&omega;t}\right)\frac{417\mathrm{\&omega;}}{25000};$

Under the state of large visual field, the equation of motion of flyback mirror 3 is:

$\mathrm{\&delta;}\left(t\right)=Z0+8.34\mathrm{\&omega;t}-\mathrm{INT}\left(6.1\mathrm{\&omega;t}\right)\frac{417\mathrm{\&omega;}}{12500};$

Above embodiment is only representative embodiment of the present invention, but the present invention also can adopt other variant embodiment, and obtains and the essentially identical technique effect of the preferred embodiment of the present invention.For example: refrigeration mode infrared focal plane detector, non-refrigeration type infrared focal plane detector that photoelectric platform adopts; The infrared focal plane detector that service band is shortwave, medium wave, long wave band; There is or does not exist intermediate image plane in lens combination 4; Infrared afocal system can be monoscopic, many visual fields or continuous vari-focus system, and under each visual field state, the flyback mirror carries out work according to the equation of motion of fast cycle flyback provided by the invention.

As can be seen from the above-described embodiment, flyback mirror fast cycle of the present invention flyback, make infrared camera stare all the time Same Scene in whole integral time or time constant, solves image blurring problem in the photoelectric platform fast rotational; The flyback mirror is placed in the optics exit pupil position of infrared afocal system, makes its size minimum, and weight is the lightest, is convenient to servocontrol; The optics entrance pupil position of infrared afocal system is positioned on the first lens group, reduces infrared camera in the size perpendicular to optical axis direction, reduces the aperture amount aberration of optical system, dwindles its volume, reduces its cost; Flyback mirror and catoptron are turned back to light path, are convenient to the miniaturization of infrared camera.

Although be the example purpose, the preferred embodiments of the present invention are disclosed, it is also possible those skilled in the art will recognize various improvement, increase and replacement, therefore, scope of the present invention should be not limited to above-described embodiment.

Claims (9)

1. an infrared optical system, is characterized in that, described infrared optical system is arranged on the photoelectric platform that adopts infrared focal plane detector; Described infrared optical system comprises first lens group, the second lens combination, flyback mirror and the 3rd lens combination; Wherein, described flyback mirror is between described the second lens combination and the 3rd lens combination; Described first lens group, the second lens combination all have positive light coke; And the rear focus F1 of described first lens group overlaps with the focus in object space F2 of the second lens combination; Described first lens group, the second lens combination form infrared afocal system; Described flyback mirror is around self turning axle rotation, cycle flyback; Each in integral time or time constant of described infrared optical system constantly all receives and is positioned at the Same Scene information of infinity, and by described the 3rd lens combination, the infrared radiation of this scene is imaged in to infrared focal plane detector;

The equation of motion of described flyback mirror cycle flyback is:

$\mathrm{\&delta;}\left(t\right)=Z0+\frac{f1}{2f2}\{{\&Integral;}_0^t\mathrm{\&omega;}\left(t\right)\mathrm{dt}-\mathrm{INT}[\frac{360{\&Integral;}_0^t\mathrm{\&omega;}\left(t\right)\mathrm{dt}}{n(1-\mathrm{\&beta;})}\left]\frac{{\&Integral;}_0^{\mathrm{\&tau;}}\mathrm{\&omega;}\left(t\right)\mathrm{dt}}{1000}\right\};$

Wherein, when δ (t) the expression time is t, the position of flyback mirror, mean with angle; The zero position that Z0 is the flyback mirror; T is the time; The focal length that f1 is the first lens group; The focal length that f2 is the second lens combination; The function that ω (t) is photoelectric platform angular velocity of rotation and time t; The integral time that τ is infrared focal plane detector or time constant; N is the scene number that the spliced panoramic image needs; β is the scene Duplication; INT is bracket function.

2. infrared optical system as claimed in claim 1, is characterized in that, when photoelectric platform at the uniform velocity rotates with angular velocity omega, the equation of motion of flyback mirror cycle flyback is:

$\mathrm{\&delta;}\left(t\right)=Z0+\frac{f1}{2f2}\{\mathrm{\&omega;t}-\mathrm{INT}[\frac{360\mathrm{\&omega;t}}{n(1-\mathrm{\&beta;})}\left]\frac{\mathrm{\&omega;\&tau;}}{1000}\right\}.$

3. infrared optical system as claimed in claim 1, is characterized in that, described flyback mirror is positioned at the exit pupil position of infrared afocal system, and the entrance pupil position of described infrared afocal system is positioned on described first lens group.

4. infrared optical system as claimed in claim 1, is characterized in that, the entrance pupil position of described the 3rd lens combination overlaps with the exit pupil position of described infrared afocal system.

5. infrared optical system as claimed in claim 1, is characterized in that, there is intermediate image face in described the 3rd lens combination, or does not have intermediate image face.

6. infrared optical system as claimed in claim 1, is characterized in that, the exit pupil position of described the 3rd lens combination overlaps with the cold stop of infrared focal plane detector.

7. infrared optical system as claimed in claim 1, is characterized in that, there is the catoptron with turnover light path in described the 3rd lens combination; Described flyback mirror is also for the light path of turning back.

8. infrared optical system as described as claim 1～7 any one, is characterized in that, described infrared optical system is applicable to non-refrigeration type or refrigeration mode infrared focal plane detector.

9. infrared optical system as described as claim 1～7 any one, is characterized in that, described infrared optical system is applicable to shortwave, medium wave or LONG WAVE INFRARED focus planardetector.

Images