阅读说明：本技术 一种具备快速像移补偿能力的连续变焦光学系统 (Continuous zooming optical system with rapid image motion compensation capability ) 是由 曲锐 梅超 陈卫宁 杨洪涛 于 2020-07-31 设计创作，主要内容包括：本发明提供一种具备快速像移补偿能力的连续变焦光学系统,解决现有技术中成像系统分辨率较低、难以兼顾大小视场搜索功能、无法实现对高速像移的有效补偿的问题。该系统包括从物面到焦面依次设置的前固定镜组、变倍镜组、补偿镜组、光阑、第五负透镜、第一折叠反射镜、中继镜组、第二折叠反射镜、后固定镜组和滤光片；前固定镜组包括第一负透镜、第一正透镜和第二正透镜；变倍镜组包括第二负透镜和第一胶合镜组；补偿镜组包括第四正透镜、第二胶合镜组和第六正透镜；中继镜组包括第六负透镜、第七正透镜、第七负透镜、第八正透镜和第三胶合镜组；后固定镜组包括第九负透镜和第十正透镜；变倍镜组和补偿镜组可沿光轴方向前后直线移动实现连续变焦。(The invention provides a continuous zooming optical system with rapid image motion compensation capability, which solves the problems that an imaging system in the prior art is low in resolution, difficult to realize both large and small view field searching functions and incapable of realizing effective compensation of high-speed image motion. The system comprises a front fixed mirror group, a zoom mirror group, a compensation mirror group, a diaphragm, a fifth negative lens, a first folding reflector, a relay mirror group, a second folding reflector, a rear fixed mirror group and an optical filter which are sequentially arranged from an object plane to a focal plane; the front fixed lens group comprises a first negative lens, a first positive lens and a second positive lens; the zoom lens group comprises a second negative lens and a first cemented lens group; the compensating lens group comprises a fourth positive lens, a second cemented lens group and a sixth positive lens; the relay lens group comprises a sixth negative lens, a seventh positive lens, a seventh negative lens, an eighth positive lens and a third cemented lens group; the rear fixed lens group comprises a ninth negative lens and a tenth positive lens; the zoom lens group and the compensation lens group can linearly move back and forth along the optical axis direction to realize continuous zooming.)

1. A continuous zoom optical system having a fast image motion compensation capability, comprising: the optical system comprises a front fixed mirror group (11), a zoom mirror group (10), a compensation mirror group (9), a diaphragm (8), a middle fixed mirror group (7), a first folding reflector (6), a relay mirror group (5), a second folding reflector (4), a rear fixed mirror group (3) and an optical filter (2) which are sequentially arranged from an object plane (12) to a focal plane (1); the central axes of the front fixed mirror group (11), the zoom mirror group (10), the compensation mirror group (9), the diaphragm (8) and the middle fixed mirror group (7) are coaxial;

the front fixed mirror group (11) comprises a first negative lens (1101), a first positive lens (1102) and a second positive lens (1103) which are sequentially arranged along the light transmission direction;

the zoom lens group (10) comprises a second negative lens (1001) and a first cemented lens group with negative focal power, which are sequentially arranged along the light transmission direction;

the compensating lens group (9) comprises a fourth positive lens (901), a second cemented lens group and a sixth positive lens (904) which are sequentially arranged along the light transmission direction, and the second cemented lens group has positive focal power;

the intermediate fixed lens group (7) comprises a fifth negative lens (701);

the relay lens group (5) comprises a sixth negative lens (501), a seventh positive lens (502), a seventh negative lens (503), an eighth positive lens (504) and a third cemented lens group which are sequentially arranged along the light transmission direction, and the third cemented lens group has negative focal power;

the rear fixed mirror group (3) comprises a ninth negative lens (301) and a tenth positive lens (302) which are sequentially arranged along the light transmission direction;

the first folding reflector (6) and the second folding reflector (4) are used for turning the light path;

the zoom lens group (10) and the compensation lens group (9) can linearly move back and forth along the optical axis direction to realize continuous zooming.

2. A zoom lens system according to claim 1, wherein: the first cemented lens group is formed by a third negative lens (1002) and a third positive lens (1003) which are sequentially arranged along the light transmission direction in a cemented manner;

the second cemented lens group is formed by a fourth negative lens (902) and a fifth positive lens (903) which are sequentially arranged along the light transmission direction in a cemented mode;

the third cemented lens group is formed by cementing an eighth negative lens (505) and a ninth positive lens (506) which are sequentially arranged along the light transmission direction.

3. A zoom lens system according to claim 2, wherein: the included angle between the reflecting surface of the first folding reflector (6) and the reflecting surface of the second folding reflector (4) and the optical axis is 45 degrees.

4. A zoom lens system according to claim 2 or 3, wherein: let the abbe number of the first negative lens (1101) to the d-line be vd1101, the abbe number of the first positive lens (1102) to the d-line be vd1102, and vd1101 and vd1102 respectively satisfy the following conditional expressions:

vd1101<45；

vd1102>70；

and setting the focal length of the front fixed lens group (11) as f11, setting the focal length of the telephoto end of the continuous zooming optical system as fL, wherein fL and f11 satisfy the following conditional expressions:

1.45<|fL/f11|<1.68。

5. a zoom lens system according to claim 4, wherein: let the abbe number of the third positive lens (1003) to the d-line be vd1003, and vd1003 satisfies the following conditional expression:

vd1003<26；

setting the focal length of the zoom lens group (10) as f10, wherein fL and f10 satisfy the following conditional expression:

6.84<|fL/f10|<8.5。

6. a zoom lens system according to claim 5, wherein: let the abbe number of the fourth positive lens (901) to the d-line be vd901, and vd901 satisfies the following conditional expression:

vd901>60；

the focal length of the compensating lens group (9) is f9, and fL and f9 satisfy the following conditional expression:

5.4<|fL/f4|<6.5。

7. a zoom lens system according to claim 6, wherein: let the abbe number of the fifth negative lens (701) to the d-line be vd701, and vd701 satisfies the following conditional expression:

vd701>52；

assuming that the focal length of the intermediate fixed lens group (7) is f7, fL and f7 satisfy the following conditional expression:

5.1<|fL/f7|<5.85。

8. a zoom lens system according to claim 7, wherein: assuming that the focal length of the relay lens group (5) is f5, fL and f5 satisfy the following conditional expression:

3.05<|fL/f5|<4.2；

assuming that the focal length of the rear fixed mirror group (3) is f3, and the focal length of the ninth negative lens (301) is f301, f3 and f301 satisfy the following conditional expressions:

2.1<|f3/f301|<3.4。

9. a zoom lens system according to claim 1, wherein: the diaphragm (8) is fixed on the side surface of the fifth negative lens (701);

the optical filter (2) is matched with the working spectrum of the optical system;

the zoom lens group (10) and the compensation lens group (9) move back and forth in a straight line in the optical axis direction through a cam-sleeve mechanism, a cam-guide rail mechanism or a servo-guide rail mechanism.

10. A zoom lens system according to claim 2, wherein: defining the surface close to the object plane side as a front surface and the surface close to the focal plane side as a rear surface;

the first negative lens (1101) has a thickness of 4.50mm, a radius of curvature of the front surface of 195.02mm, and a radius of curvature of the rear surface of 92.43 mm;

the thickness of the first positive lens (1102) is 12.00mm, the curvature radius of the front surface of the first positive lens is 93.65mm, and the curvature radius of the rear surface of the first positive lens is-1002.36 mm;

the thickness of the second positive lens (1103) is 12.00mm, the curvature radius of the front surface of the second positive lens is 90.52mm, and the curvature radius of the rear surface of the second positive lens is-1119.61 mm;

the thickness of the second negative lens (1001) is 1.80mm, the curvature radius of the front surface of the second negative lens is-166.62 mm, and the curvature radius of the rear surface of the second negative lens is 51.89 mm;

the thickness of the third negative lens (1002) is 1.80mm, and the curvature radius of the front surface of the third negative lens is-66.70 mm;

the thickness of the third positive lens (1003) is 3.92mm, the curvature radius of the gluing surface of the third positive lens and the third negative lens (1002) is 57.08mm, and the curvature radius of the rear surface of the third positive lens (1003) is 190.53 mm;

the thickness of the fourth positive lens (901) is 4.59mm, the curvature radius of the front surface of the fourth positive lens is 104.36mm, and the curvature radius of the rear surface of the fourth positive lens is-88.68 mm;

the thickness of the fourth negative lens (902) is 1.80mm, and the curvature radius of the front surface of the fourth negative lens is 91.01 mm;

the thickness of the fifth positive lens (903) is 5.55mm, the curvature radius of the gluing surface of the fifth positive lens (903) and the fourth negative lens (902) is 39.39mm, and the curvature radius of the rear surface of the fifth positive lens (903) is-239.75 mm;

the thickness of the sixth positive lens (904) is 4.59mm, the curvature radius of the front surface of the sixth positive lens is 86.67mm, and the curvature radius of the rear surface of the sixth positive lens is 1071.59 mm;

the thickness of the fifth negative lens (701) is 1.80mm, the curvature radius of the front surface of the fifth negative lens is-68.97 mm, and the curvature radius of the rear surface of the fifth negative lens is 42.09 mm;

the thickness of the sixth negative lens (501) is 1.80mm, the curvature radius of the front surface of the sixth negative lens is-242.04 mm, and the curvature radius of the rear surface of the sixth negative lens is 28.90 mm;

the thickness of the seventh positive lens (502) is 6.28mm, the curvature radius of the front surface of the seventh positive lens is 34.80mm, and the curvature radius of the rear surface of the seventh positive lens is-131.33 mm;

the thickness of the seventh negative lens (503) is 15.00mm, the curvature radius of the front surface of the seventh negative lens is-2482.24 mm, and the curvature radius of the rear surface of the seventh negative lens is 37.8230 mm;

the thickness of the eighth positive lens (504) is 6.45mm, the curvature radius of the front surface of the eighth positive lens is 32.91mm, and the curvature radius of the rear surface of the eighth positive lens is-37.18 mm;

the thickness of the eighth negative lens (505) is 1.80mm, and the curvature radius of the front surface of the eighth negative lens is-38.07 mm;

the thickness of the ninth positive lens (506) is 6.02mm, the curvature radius of the gluing surface of the ninth positive lens and the eighth negative lens (505) is 27.27mm, and the curvature radius of the rear surface is-48.59 mm;

the thickness of the ninth negative lens (301) is 1.80mm, the curvature radius of the front surface of the ninth negative lens is-30.24 mm, and the curvature radius of the rear surface of the ninth negative lens is-83.57 mm;

the thickness of the tenth positive lens (302) is 8.33mm, and the radius of curvature of the front surface thereof is 43.17 mm.

Technical Field

The invention belongs to the technical field of photoelectricity, relates to a continuous zooming optical system, and particularly relates to a continuous zooming optical system with rapid image motion compensation capability.

Background

In recent years, scanning type surface array detection imaging systems are rapidly developed aiming at the application demand fields of aerial remote sensing, panoramic early warning and the like, wherein the surface array scanning imaging systems which have a continuous zooming function and can realize large visual field searching and small visual field detailed investigation are focused. The imaging system requires the photoelectric platform to scan and image in the azimuth 360 degrees or a specific angle range at a certain rotating speed, and performs gaze tracking on a specific target area. However, the area array detector generates relative motion between the focal plane and the scenery in the integration time, so that image motion is generated, and if corresponding image motion compensation measures are not adopted, imaging blurring is easily caused, and the use efficiency is influenced.

In the prior art, for an area array scanning imaging system, the method for compensating image motion mainly includes: electronically compensated and mechanically compensated. The electronic compensation is mainly realized by technologies such as integration time reduction, digital TDI and electronic anti-shake, and can realize automatic compensation of the intermediate image moving speed, but cannot adapt to the application occasions of the high image moving speed such as peripheral scan imaging. The mechanical compensation type is that a mechanism capable of reversely compensating scanning image motion is introduced into an optical path, and a servo mechanism is driven to reversely move through real-time acquisition and processing of a motion signal, so that the compensation of the image motion is realized; the mechanism comprises an optical anti-shake mechanism for driving the lens group to move, an image space compensation mechanism for driving the detector component to move reversely, an object space compensation mechanism for driving the pointing mirror component to move reversely, a compensation mechanism for driving the space folding mirror component to move reversely and the like. The former three can not realize effective compensation of high-speed image motion due to low compensation capability, poor reliability, large inertia of components and the like. The compensation mechanism for driving the space folding mirror assembly to move reversely has the characteristics of small weight, low power consumption, high frequency, high reliability and the like, and is a preferred mode of high-speed image motion compensation.

In the existing optical system with high-speed image motion compensation capability, the area array scanning zoom imaging system aiming at the application fields of aerial remote sensing, panoramic early warning and the like is multi-functional in a medium-long wave infrared spectrum band, has low resolution and cannot meet application scenes with high resolution requirements; some area array scanning devices working in a visible spectrum section are mostly focus fixing systems, and the function of searching and detailed investigation of large and small view fields cannot be considered; in the visible spectrum, the continuous zoom system with the image stabilizing function is difficult to realize the rapid image motion compensation under the working conditions such as swinging and sweeping.

In 2020, a document published in infrared and laser engineering, journal of China, entitled "design of two-level zoom area array scanning infrared optical system", discloses an optical system having a 73mm/180mm two-level area array scanning function, a working band of 3.7-4.8 μm, an array of 640 × 512, a pixel size of 15 μm, and an F number of 2. When the focal length of the system is 73mm, the frequency of the area array periodic scanning is 1 second/circle respectively; when the focal length of the infrared system is 180mm, the frequency of area array circumferential scanning is 2.47 seconds/circle, rapid image motion compensation can be realized, but the size of an infrared detector pixel is large, and the high resolution of a visible light image is difficult to achieve.

In 2020, a 60-360 mm continuous zooming area array scanning medium wave optical system is disclosed in a document entitled "design of six-time continuous zooming area array scanning infrared optical system" published in the journal of China, and the area array circumferential scanning function similar to that of the document is realized. But also has a problem of low imaging resolution.

For example, the chinese patent publication No. CN 103345048B discloses a high-magnification zoom camera lens suitable for an image stabilization system, and the disclosed lens mainly solves the problem of image stabilization under vibration conditions, and has a resolution that can be adapted to a super-mega pixel detector, a focal length range of 31mm to 620mm, a relative aperture D/f of 1/5 to 1/8, a field angle of 2 ω of 22.1 to 1.11 °, and image stabilization under vibration conditions is realized by reversely swinging a folding mirror disposed in an optical path. However, the lens is difficult to adapt to detectors with more than ten million resolutions, and is also difficult to realize rapid image motion compensation under working conditions such as sweep and cycle sweep.

Therefore, there is an urgent need to design a continuous zoom optical system capable of realizing visible-near infrared broadband high-resolution imaging and having a fast image motion compensation capability.

Disclosure of Invention

The invention provides a continuous zooming optical system with rapid image motion compensation capability, aiming at solving the technical problems that the prior art is low in compensation capability, poor in reliability, large in component inertia, incapable of realizing effective compensation on high-speed image motion, low in resolution of an area array scanning zooming imaging system working in a medium-long wave infrared spectrum band, and difficult to give consideration to the large and small view field searching detailed searching function because most area array scanning equipment working in a visible spectrum band is a fixed focus system.

In order to achieve the purpose, the technical scheme provided by the invention is as follows:

a continuous zooming optical system with fast image motion compensation capability is characterized in that: the optical filter comprises a front fixed mirror group, a zoom mirror group, a compensation mirror group, a diaphragm, a middle fixed mirror group, a first folding reflector, a relay mirror group, a second folding reflector, a rear fixed mirror group and an optical filter which are sequentially arranged from an object plane to a focal plane; the central axes of the front fixed lens group, the zoom lens group, the compensation lens group, the diaphragm and the middle fixed lens group are coaxial;

the front fixed mirror group comprises a first negative lens, a first positive lens and a second positive lens which are sequentially arranged along the light transmission direction;

the zoom lens group comprises a second negative lens and a first cemented lens group with negative focal power, which are sequentially arranged along the light transmission direction;

the compensation lens group comprises a fourth positive lens, a second cemented lens group and a sixth positive lens which are sequentially arranged along the light transmission direction, and the second cemented lens group has positive focal power;

the middle fixed lens group comprises a fifth negative lens;

the relay lens group comprises a sixth negative lens, a seventh positive lens, a seventh negative lens, an eighth positive lens and a third cemented lens group which are sequentially arranged along the light transmission direction, and the third cemented lens group has negative focal power;

the rear fixed mirror group comprises a ninth negative lens and a tenth positive lens which are sequentially arranged along the light transmission direction;

the first folding reflector and the second folding reflector are used for turning the light path;

the zoom lens group and the compensation lens group can linearly move back and forth along the optical axis direction, so that continuous zooming is realized.

Furthermore, the first cemented lens group is formed by cementing a third negative lens and a third positive lens which are sequentially arranged along the light transmission direction;

the second cemented lens group is formed by a fourth negative lens and a fifth positive lens which are sequentially arranged along the light transmission direction;

the third cemented lens group is formed by cementing an eighth negative lens and a ninth positive lens which are sequentially arranged along the light transmission direction.

Furthermore, the included angle between the reflecting surface of the first folding reflector and the optical axis and the included angle between the reflecting surface of the second folding reflector and the optical axis are both 45 degrees.

Further, let the abbe number of the first negative lens pair d-line be vd1101, the abbe number of the first positive lens pair d-line be vd1102, and vd1101 and vd1102 respectively satisfy the following conditional expressions:

vd1101<45；

vd1102>70；

assuming that the focal length of the front fixed lens group is f11, and the focal length of the telephoto end of the continuous zoom optical system is fL, fL and f11 satisfy the following conditional expressions:

1.45<|fL/f11|<1.68。

further, let the abbe number of the third positive lens to the d-line be vd1003, and vd1003 satisfies the following conditional expression:

vd1003<26；

setting the focal length of the zoom lens group as f10, wherein fL and f10 satisfy the following conditional expression:

6.84<|fL/f10|<8.5。

further, let the abbe number of the fourth positive lens to the d-line be vd901, and vd901 satisfies the following conditional expression:

vd901>60；

assuming that the focal length of the compensating lens group is f9, fL and f9 satisfy the following conditional expression:

5.4<|fL/f4|<6.5。

further, let the abbe number of the fifth negative lens to the d-line be vd701, and vd701 satisfies the following conditional expression:

vd701>52；

assuming that the focal length of the intermediate fixed lens group is f7, fL and f7 satisfy the following conditional expression:

5.1<|fL/f7|<5.85。

further, assuming that the focal length of the relay lens group is f5, fL and f5 satisfy the following conditional expression:

3.05<|fL/f5|<4.2；

assuming that the focal length of the rear fixed mirror group is f3, and the focal length of the ninth negative lens element is f301, f3 and f301 satisfy the following conditional expressions:

2.1<|f3/f301|<3.4。

further, the diaphragm is fixed on the side surface of the fifth negative lens;

the optical filter is matched with the working spectrum of the optical system;

the zoom lens group and the compensation lens group move back and forth in a straight line in the optical axis direction through a cam-sleeve mechanism, a cam-guide rail mechanism or a servo-guide rail mechanism.

Further, a surface close to the object plane side is defined as a front surface, and a surface close to the focal plane side is defined as a rear surface;

the thickness of the first negative lens is 4.50mm, the curvature radius of the front surface of the first negative lens is 195.02mm, and the curvature radius of the rear surface of the first negative lens is 92.43 mm;

the thickness of the first positive lens is 12.00mm, the curvature radius of the front surface of the first positive lens is 93.65mm, and the curvature radius of the rear surface of the first positive lens is-1002.36 mm;

the thickness of the second positive lens is 12.00mm, the curvature radius of the front surface of the second positive lens is 90.52mm, and the curvature radius of the rear surface of the second positive lens is-1119.61 mm;

the thickness of the second negative lens is 1.80mm, the curvature radius of the front surface of the second negative lens is-166.62 mm, and the curvature radius of the rear surface of the second negative lens is 51.89 mm;

the thickness of the third negative lens is 1.80mm, and the curvature radius of the front surface of the third negative lens is-66.70 mm;

the thickness of the third positive lens is 3.92mm, the curvature radius of the cemented surface of the third positive lens and the third negative lens is 57.08mm, and the curvature radius of the rear surface of the third positive lens is 190.53 mm;

the thickness of the fourth positive lens is 4.59mm, the curvature radius of the front surface of the fourth positive lens is 104.36mm, and the curvature radius of the rear surface of the fourth positive lens is-88.68 mm;

the thickness of the fourth negative lens is 1.80mm, and the curvature radius of the front surface of the fourth negative lens is 91.01 mm;

the thickness of the fifth positive lens is 5.55mm, the curvature radius of the cemented surface of the fifth positive lens and the fourth negative lens is 39.39mm, and the curvature radius of the rear surface of the fifth positive lens is-239.75 mm;

the thickness of the sixth positive lens is 4.59mm, the curvature radius of the front surface of the sixth positive lens is 86.67mm, and the curvature radius of the rear surface of the sixth positive lens is 1071.59 mm;

the thickness of the fifth negative lens is 1.80mm, the curvature radius of the front surface of the fifth negative lens is-68.97 mm, and the curvature radius of the rear surface of the fifth negative lens is 42.09 mm;

the thickness of the sixth negative lens is 1.80mm, the curvature radius of the front surface of the sixth negative lens is-242.04 mm, and the curvature radius of the rear surface of the sixth negative lens is 28.90 mm;

the thickness of the seventh positive lens is 6.28mm, the curvature radius of the front surface of the seventh positive lens is 34.80mm, and the curvature radius of the rear surface of the seventh positive lens is-131.33 mm;

the thickness of the seventh negative lens is 15.00mm, the curvature radius of the front surface of the seventh negative lens is-2482.24 mm, and the curvature radius of the rear surface of the seventh negative lens is 37.8230 mm;

the thickness of the eighth positive lens is 6.45mm, the curvature radius of the front surface of the eighth positive lens is 32.91mm, and the curvature radius of the rear surface of the eighth positive lens is-37.18 mm;

the thickness of the eighth negative lens is 1.80mm, and the curvature radius of the front surface of the eighth negative lens is-38.07 mm;

the thickness of the ninth positive lens is 6.02mm, the curvature radius of the cemented surface of the ninth positive lens and the eighth negative lens is 27.27mm, and the curvature radius of the rear surface is-48.59 mm;

the thickness of the ninth negative lens is 1.80mm, the curvature radius of the front surface of the ninth negative lens is-30.24 mm, and the curvature radius of the rear surface of the ninth negative lens is-83.57 mm;

the thickness of the tenth positive lens is 8.33mm, and the radius of curvature of the front surface thereof is 43.17 mm.

Compared with the prior art, the invention has the advantages that:

1. the optical system can realize the function of fast image motion compensation, realize large-area array ultrahigh-definition imaging in the range of a full zoom segment, and realize the function of continuous zoom which is not less than 10 times. In the process of fast image motion, all focal length central view fields and all edge view fields have better imaging quality.

2. The optical system of the invention comprises a zoom nucleus consisting of a zoom lens group and a compensating lens group, and continuously moves according to a given movement rule by design, and the zoom form is inner zoom. In the zooming process, the zoom lens group and the compensation lens group move back and forth on the optical axis all the time, and when zooming, the F number of the diaphragm is constant, the total length is fixed, the mass center change is small, the system is small in size and compact in structure.

3. The optical system has the capabilities of continuous zooming and broadband detection, can effectively realize the miniaturization, light weight and integration of detection means, can also reduce the difficulty of optical debugging, can give consideration to both large-view-field search detection and small-view-field identification and recognition, and can realize the functions of optical fog penetration, multi-band imaging and the like.

4. The optical system fixedly locates the diaphragm at the outer side of the middle fixed lens group close to the objective side lens, and can reserve enough space for adopting different types of diaphragms so as to ensure that the relative aperture of the continuous zooming optical system is constant, and is manually or automatically changed, thereby improving the modularization level of the continuous zooming optical system; on the other hand, the diaphragm is imaged at a far distance of the image surface side through the subsequent lens group to form a quasi-image-space telecentric light path, so that the whole image surface can be ensured to have uniform relative illumination distribution.

5. The relay lens group and the rear fixed lens group of the optical system form a Petzmann structure, and the optical system ensures that each focal length and each view field of the optical system have good image surface illumination distribution and simultaneously have excellent distortion characteristics by combining the design form of quasi-image space telecentric.

6. The optical system is suitable for various electric aiming pods and turrets, civil police monitoring, searching, tracking and aiming and the like, and is particularly suitable for various equipment such as sweep imaging, panoramic imaging and the like.

7. The optical system has small volume and compact structure, is particularly suitable for large-area array imaging, can realize the continuous zooming function and has the rapid image motion compensation capability.

8. The optical filter of the optical system can be replaced according to working requirements, and when the optical system needs to work under a color imaging condition, the infrared cut-off optical filter is cut in, so that the color information of the formed image is uniform and rich; when the optical system needs to work in a full-color mode or other spectral bands, the optical system is cut into the optical filter of the corresponding spectral band, and then an optical image of the corresponding spectral band can be obtained.

Drawings

FIG. 1 is a diagram of an optical path structure of a zoom lens system with fast image motion compensation capability according to the present invention;

FIG. 2 is a short focus state optical path diagram of the continuous zoom optical system with fast image motion compensation capability according to the present invention;

FIG. 3 is a diagram of the optical path in the focal state of the continuous zoom optical system with fast image motion compensation capability according to the present invention;

FIG. 4 is a long-focus optical path diagram of the continuous zoom optical system with fast image motion compensation capability according to the present invention;

wherein the reference numbers are as follows:

1-focal plane, 2-filter;

3-rear fixed lens group, 301-ninth negative lens, 302-tenth positive lens;

4-a second fold mirror;

5-a relay lens group, 501-a sixth negative lens, 502-a seventh positive lens, 503-a seventh negative lens, 504-an eighth positive lens, 505-an eighth negative lens, 506-a ninth positive lens;

6-a first folding mirror;

7-middle fixed lens group, 701-fifth negative lens;

8-diaphragm;

9-a compensating lens group, 901-a fourth positive lens, 902-a fourth negative lens, 903-a fifth positive lens and 904-a sixth positive lens;

10-a zoom lens group, 1001-a second negative lens, 1002-a third negative lens and 1003-a third positive lens;

11-front fixed lens group, 1101-first negative lens, 1102-first positive lens, 1103-second positive lens;

12-object plane.

Detailed Description

The invention is described in further detail below with reference to the figures and specific embodiments.

As shown in fig. 1, a continuous zoom optical system with fast image motion compensation capability includes a front fixed mirror set 11, a zoom mirror set 10, a compensation mirror set 9, a diaphragm 8, a middle fixed mirror set 7, a first folding mirror 6, a relay mirror set 5, a second folding mirror 4, a rear fixed mirror set 3 and an optical filter 2, which are sequentially arranged from an object plane 12 to a focal plane 1 (image plane); the object side of the front fixed lens group 11 is an object surface 12 of the continuous zooming optical system, and the image side of the optical filter 2 is a focal surface 1 of the continuous zooming optical system; the central axes of the front fixed mirror group 11, the zoom mirror group 10, the compensation mirror group 9, the diaphragm 8, the middle fixed mirror group 7, the relay mirror group 5, the rear fixed mirror group 3 and the optical filter 2 are coaxial.

The zoom lens group 10 and the compensating lens group 9 are driven by a driving mechanism to synchronously move linearly back and forth (left and right directions in fig. 1) in the optical axis direction of the continuous zooming optical system to realize connection zooming, and the driving mechanism can be a cam-sleeve mechanism, a cam-guide rail mechanism or a servo-guide rail mechanism and other similar driving mechanisms; the total length of the continuous zoom optical system of the present embodiment is constant during continuous zooming.

In this embodiment, the front fixed lens group 11, the zoom lens group 10, the compensation lens group 9, the diaphragm 8 and the middle fixed lens group 7 together form a front quasi-afocal telescope group, and the relay lens group 5 and the rear fixed lens group 3 together form an imaging objective lens group.

The optical system of the present embodiment includes the following lens groups:

1. front fixed lens group 11

The front fixed mirror group 11 comprises a first negative lens 1101, a first positive lens 1102 and a second positive lens 1103 which are coaxially arranged in sequence along the light transmission direction; let the abbe number of the first negative lens 1101 for the d-line be vd1101, the abbe number of the first positive lens 1102 for the d-line be vd1102, and vd1101 and vd1102 satisfy the following conditional expressions:

vd1101<45； (1)

vd1102>70； (2)

the conditional expressions (1) and (2) are conditional expressions that specify the front fixed mirror group 11 to favorably correct chromatic aberration generated with respect to the entire operating spectral range across the full zoom region. By forming the first negative lens 1101 in the front fixed mirror group 11 from a high dispersion material satisfying the conditional expression (1) and forming the first positive lens 1102 in the front fixed mirror group 11 from a low dispersion material satisfying the conditional expression (2), chromatic aberration generated with respect to the entire operating spectrum range across the entire variable power region can be corrected well over the entire variable power region. If the upper limit of the conditional expression (1) is exceeded or the lower limit of the conditional expression (2) is fallen below, it becomes difficult to correct chromatic aberration introduced by the optical material.

Further, assuming that the focal length of the front fixed lens group 11 is f11 and the focal length at the telephoto end of the continuous zoom optical system of the present embodiment is fL, fL and f11 satisfy the following conditional expressions:

1.45<|fL/f11|<1.68； (3)

the conditional expression (3) is a minimum expression that specifies the influence of the front fixed mirror group 11 on the defocus at the telephoto end of the optical system. The influence of the front fixed mirror group 11 on the defocusing of the long-focus section of the whole optical system can be minimized when the environment changes. By the front fixed mirror group 11 satisfying the power limitation of the conditional expression (3), the defocus generated by the environmental change can be corrected well in the full zoom range, particularly, the telephoto section. If the range exceeds the conditional expression (3), it becomes difficult to correct the ambient defocus in the long-focus range of the optical system.

Thus, the front fixed lens group 11 having a longer focal length and a positive focal power can be arranged on the side of the optical system closest to the object plane 12, which is advantageous for the miniaturization of the optical system; the front fixed mirror group 11 can satisfactorily correct chromatic aberration occurring across a full zoom region with respect to light from a visible light region to a near-infrared light region.

2. Zoom lens group 10

The zoom lens group 10 comprises a second negative lens 1001 and a first cemented lens group coaxially arranged in sequence along the light transmission direction; the first cemented lens group has negative focal power and is formed by a third negative lens 1002 and a third positive lens 1003 which are sequentially arranged along the light transmission direction in a cemented mode; let the focal length of the variable power lens group 10 be f10, the abbe number of the third positive lens 1003 to the d-line be vd1003, and fL, f10 and vd1003 satisfy the following conditional expressions:

6.84<|fL/f10|<8.5； (4)

vd1003<26； (5)

the conditional expression (4) is an expression for limiting the focal length range of the zoom lens group 10, and by satisfying the conditional expression (4), the aperture of the lens group behind the zoom lens group 10 can be effectively compressed, the incident angle of light on the surface of the rear lens group is reduced, and the difficulty in aberration correction of the rear lens group is reduced. If the value is less than the lower limit of the conditional expression (4), the amount of movement of the variable power lens group 10 increases, and the aperture of the group lens after the variable power lens group 10 increases, which makes it difficult to downsize the optical system. On the other hand, if the upper limit is exceeded in conditional expression (4), it is advantageous to miniaturize the optical system, but it becomes difficult to correct distortion particularly in the short focal end, and optical performance deteriorates.

The conditional expression (5) is a conditional expression for specifying that chromatic aberration generated by the variable power lens group 10 with respect to light in the entire operating band region is corrected well across the full variable power region. By forming the third positive lens 1003 in the variable power lens group 10 from a high dispersion material satisfying the conditional expression (5), chromatic aberration generated in the variable power lens group 10 with respect to light in the operating spectral range can be corrected well in the full variable power range. If the conditional expression (5) is higher than the upper limit thereof, it is difficult to correct the on-axis chromatic aberration, and the chromatic aberration generated in the light over the entire operating band cannot be sufficiently corrected.

In this way, the variable power lens group 10 can compress the rear group aperture, excellently correct aberration generated along with the increase in aperture, ensure rapid zooming of the optical system, and excellently correct chromatic aberration generated with respect to light in the operating band range in the full variable power range.

3. Compensating lens group 9

The compensating lens group 9 comprises a fourth positive lens 901, a second cemented lens group and a sixth positive lens 904 which are coaxially arranged in sequence along the light transmission direction; the second cemented lens group has positive focal power, and is formed by a fourth negative lens 902 and a fifth positive lens 903 which are sequentially arranged along the light transmission direction in a cemented manner;

assuming that the focal length of the compensating lens group 9 is f9, the abbe number of the fourth positive lens 901 to the d-line is vd901, fL, f9 and vd901 satisfy the following conditional expressions:

5.4<|fL/f4|<6.5； (6)

vd901>60； (7)

the conditional expression (6) is an expression for defining the focal length range of the compensating lens group 9 associated with the variable power lens group 10. By satisfying the conditional expression (6), the optical system compensating lens group 9 can be ensured to move smoothly and rapidly, and astigmatism and curvature of field generated by the movement of the zoom lens group 10 can be better corrected. If the lower limit of the conditional expression (6) is exceeded, the amount of movement of the compensating lens group 9 increases, making it difficult to downsize the optical system. On the other hand, if it is higher than the upper limit in conditional expression (6), the correction of astigmatism and curvature of field introduced by the variable power lens group in the optical system becomes difficult, resulting in deterioration of optical performance.

The conditional expression (7) is a conditional expression for defining a correction factor for excellently correcting chromatic aberration generated by light of the entire operating band region across the full magnification range, as in the conditional expressions (1), (2), and (5). The fourth positive lens 901 of the compensating mirror group 9 is formed of a low dispersion material satisfying the conditional expression (7), and chromatic aberration generated by light in the entire operating band across the full zoom region is further corrected well. If the value is less than the lower limit of conditional expression (7), it becomes difficult to correct the off-axis chromatic aberration in the compensating mirror group 9.

Therefore, the compensating lens group 9 can independently correct chromatic aberration generated by each lens in the group, partially compensate astigmatism and field curvature introduced by the zoom lens group 10, ensure that the zooming process moves smoothly and rapidly, realize miniaturization of a zooming nucleus of an optical system, and can achieve good chromatic aberration correction in the lens group of the compensating lens group 9.

4. Middle fixed lens group 7

The middle fixed lens group 7 is of a single-piece structure and is composed of a fifth negative lens 701; assuming that the focal length of the intermediate fixed lens group 7 is f7, the abbe number of the fifth negative lens 701 to the d-line is vd701, fL, f7 and vd701 satisfy the following conditional expressions:

5.1<|fL/f7|<5.85； (8)

vd701>52； (9)

the conditional expression (8) is an expression for defining the focal length range of the intermediate fixed mirror group 7. By satisfying the conditional expression (8), the spherical aberration and the coma generated by the large view field of the front quasi-afocal telescope group can be effectively compensated, so that the angle compensation range of the first folding reflector 6 is enlarged, and the large-angle rapid image motion compensation is realized. If the conditional expression (8) is lower than the lower limit thereof, it becomes difficult to make the front quasi-afocal telescope group have a large field of view. On the other hand, if the upper limit is exceeded in conditional expression (8), it is advantageous to enlarge the field of view of the front quasi-afocal telephoto lens group, but excessive spherical aberration and coma aberration are introduced, and the image formed by the optical system is blurred.

The conditional expression (9) is a conditional expression for specifying that the intermediate fixed mirror corrects chromatic aberration occurring with the movement of each moving group across the full magnification change region. By forming the fifth negative lens 701 in the intermediate fixed lens group 7 from a medium dispersion material satisfying the conditional expression (9), chromatic aberration generated by the movement of each movable group can be corrected satisfactorily in the intermediate fixed lens group 7. In addition, if the conditional expression (9) is lower than the lower limit thereof, the correction of chromatic aberration in the front quasi-afocal telephoto lens group becomes difficult, and the optical structure of the imaging object group of the subsequent lens becomes complicated.

Thus, the intermediate fixed mirror group 7 can minimize various aberrations generated along with the large field of view of the front quasi-afocal telescope group, and can realize large-angle fast image motion compensation of the first folding mirror 6.

5. Diaphragm 8

The diaphragm 8 is fixed on the object side of the fifth negative lens 701, and may be a diaphragm with a fixed clear aperture or a diaphragm with a variable clear aperture.

6. First folding mirror 6

The first folding reflector 6 is located in the quasi-parallel optical path between the middle fixed mirror group 7 and the relay mirror group 5, and performs 45-degree spatial folding on the optical path, turning the optical path by 90 °. The first folding reflector 6 is positioned in the quasi-parallel optical path and is a quick reflector, corresponding action is carried out through motion information input by a closed loop, and real-time high-precision compensation of imaging image motion of the optical system is realized.

7. Relay lens group 5

The relay lens group 5 comprises a sixth negative lens 6, a seventh positive lens 502, a seventh negative lens 503, an eighth positive lens 504 and a third cemented lens group which are coaxially arranged in sequence along the light transmission direction; the third cemented lens group has negative focal power, and is formed by a eighth negative lens 505 and a ninth positive lens 506 which are sequentially arranged along the light transmission direction; assuming that the focal length of the relay lens group 5 is f5, fL and f5 satisfy the following conditional expressions:

3.05<|fL/f5|<4.2； (10)

the conditional expression (10) is an expression for defining the focal length range of the relay lens group 5. By satisfying the conditional expression (10), the length of the front quasi-afocal telescope group and the caliber of the first folding reflector 6 can be effectively compressed, and the miniaturization of the space envelope of the optical system is realized. If conditional expression (10) is less than the lower limit, the aperture of the first folding mirror 6 becomes large, and the control bandwidth requirement becomes high, which is problematic. On the other hand, if the upper limit is exceeded in conditional expression (10), it is advantageous to reduce the aperture of the first folding mirror, but it is difficult to reduce the envelope of the optical system by increasing the length of the front quasi-afocal telephoto lens group.

Therefore, the relay lens group 5 can compress the length and the caliber of the zoom nucleus of the optical system, and the miniaturization of the space envelope of the optical system is realized.

8. Second folding mirror 4

The second folding reflector 4 is located between the relay lens group 5 and the rear fixed lens group 3, and performs 45-degree spatial folding on the light path to turn the light path by 90 degrees.

9. Rear fixed lens group 3

The rear fixed mirror group 3 comprises a ninth negative lens 301 and a tenth positive lens 302 which are sequentially arranged along the light transmission direction; assuming that the focal length of the rear fixed mirror group 3 is f3 and the focal length of the eighth negative lens 505 is f301, f3 and f301 satisfy the following conditional expressions:

2.1<|f3/f301|<3.4； (11)

satisfying the conditional expression (11), the field curvature and distortion generated with the large-area detector can be effectively corrected, and the spatial folding of the optical system is facilitated. If conditional expression (11) is lower than the lower limit thereof, it becomes difficult to correct curvature of field and distortion. On the other hand, if the upper limit is exceeded in conditional expression (11), it is advantageous to correct curvature of field and distortion that occur with the use of a large-area detector, but excessive coma and astigmatism are introduced, and an image formed by the optical system is blurred.

In this embodiment, the rear fixed mirror group 3 and the relay mirror group 5 cooperate to form a pettzmann optical structure, which corrects the field curvature and distortion associated with the large-area array detector and is beneficial to the spatial folding of the optical system.

The optical filter 2 is positioned between the rear fixed mirror group 3 and the focal plane 1, the selection of the optical filter is matched with the working spectrum section of the optical system, the optical filter 2 can comprise various optical filters of different types, the optical filter 2 placed in front of the focal plane 1 can be replaced, and when the optical system needs to work under the color imaging condition, the optical system is cut into the infrared cut-off optical filter 2, so that the color information of the formed image is uniform and rich; when the optical system needs to work in a full color mode or other spectral bands, the optical system is cut into the optical filter 2 of the corresponding spectral band, and then an optical image of the corresponding spectral band can be obtained.

The zoom optical system of the embodiment can realize rapid image motion compensation, continuous zooming, miniaturization and ultrahigh-definition imaging, and can well correct various aberrations generated by light in the whole working spectral range in a full zoom region to obtain better optical performance.

As shown in fig. 2 to 4, the zoom lens group 10 and the compensating lens group 9 move under the driving of the driving mechanism, and when the zoom lens group 10 changes to the telephoto, the zoom lens group 10 moves toward the focal plane 1, which is in the telephoto state as shown in fig. 4; when the focal length is changed to the short focal length, the zoom lens group 10 moves toward the object plane 12, which is in the short focal length state as shown in fig. 2; the focal length is continuously changed during the movement, and the optical path diagram of the intermediate focus state is shown in fig. 3.

The continuous zoom optical system of this embodiment has 6 lens groups, in order from the object plane 12 to the focal plane 1, a front fixed lens group 11 having positive focal power, a zoom lens group 10 having negative focal power, a compensation lens group 9 having positive focal power, an intermediate fixed lens group 7 having negative focal power, a relay lens group 5 having positive focal power, and a rear fixed lens group 3 having positive focal power, and the light receiving surface of an imaging element such as a CCD or a CMOS is disposed on the focal plane 1 (image forming surface).

Various numerical data relating to the zoom optical system of the present embodiment are as follows:

working spectral range: 450 nm-950 nm

Diagonal angle of view: (2 ω) ═ 4.2 ° (tele end) -43.8 ° (tele end)

Adaptive focal plane 1 size: 14.5mm by 14.5mm

Edge field resolution: not less than 180lp/mm

Clear imaging range: 5 m-INF

F/# ═ 5, F #, i.e. the F-number is the reciprocal of the ratio of entrance pupil aperture to focal length, i.e. F ═ F/D

Front quasi-afocal telescope group magnification: 0.37X-3.7 strap

The swing range of the fast reflecting mirror is as follows: plus or minus 0.5 degree

Working temperature range: minus 45 ℃ to plus 70 DEG C

Tables 1, 2 and 3 below show optical parameter data of the zoom optical system of the embodiment.

TABLE 1 concrete parameters (unit: mm) of each lens of the optical system of this example

Table 2 variable surface interval data of the optical system of the present embodiment

Table 3 parameter table of the optical system of the present embodiment

Serial number	Condition	Parameter value
			1	vd1101	40.8
2	vd1102	81.6
			3	|fL/f11|	1.56
4	|fL/f10|	7.32
			5	vd1003	17.9
6	|fL/f4|	5.98
			7	vd901	81.6
8	|fL/f7|	5.46
			9	vd701	64.2
10	|fL/f5|	3.74

In this embodiment, the total envelope from the surface of the front fixed mirror group 11 close to the object plane 12 to the focal plane 1 is less than 220mm × 90mm × 75mm, the maximum aperture of each lens is not more than 75mm, the focal length range is 27mm to 270mm, the zoom ratio is 10, and the adaptive imaging sensor has a diagonal size not less than 20.5 mm. In the zooming process, the total length of the system is constant, the F number is fixed and is continuously changed along with the change of the focal length position, the system has smaller volume and lighter weight, and belongs to internal zooming, and the mass center is not greatly changed in the zooming process.

In the optical system of this embodiment, the iris diaphragm 8 is an iris diaphragm, and is located at a fixed position close to the image space side of the middle fixed mirror group, so that when the focal length or the external environment illumination of the optical system changes, the size of the aperture can be adjusted, the better imaging contrast can be ensured, and the dynamic range of the imaging component can be widened.

The optical system of the embodiment has the advantages of small total number of related lenses and good tolerance characteristic. The optical materials used by the lens groups can be common optical glass materials, and have better acquirable and processable characteristics.

The optical system lens of the embodiment can adopt a lens material combination matched with the linear expansion coefficient of the lens cone material and an electric active or manual focusing compensation mode in a full temperature range of-45 ℃ to +70 ℃ to compensate the defocusing caused by the temperature change of the lens cone material and the environmental air pressure change.

The above description is only for the purpose of describing the preferred embodiments of the present invention and does not limit the technical solutions of the present invention, and any known modifications made by those skilled in the art based on the main technical concepts of the present invention fall within the technical scope of the present invention.