CN219496791U - Gas imaging continuous zoom lens - Google Patents

Abstract

The application discloses gas imaging continuous zoom lens, zoom mechanical component includes: zoom subassembly, focusing subassembly, hold and set up in main lens cone: the device comprises a front fixed group, a zoom group, a first compensation component, a second compensation component, a focusing group and a rear fixed group; the front fixed group, the zoom group, the first compensation component, the second compensation component, the focusing group and the rear fixed group are sequentially arranged from the object image end to the object image end of the lens; the second compensation assembly includes: a third lens frame and a fourth pressing ring; the second compensation group lens D is accommodated in the third lens frame and is installed by pressing through a fourth pressing ring; one end face of the third mirror frame is provided with a weight-reducing annular groove, and the other end face of the third mirror frame is provided with a plurality of weight-reducing holes. In the mechanical assembly for installing the optical system in the lens, the main lens barrel, the cam barrel and the lens frame are respectively designed in a light-weight manner, so that the total mass of the lens is effectively reduced, and the design effect of compact structure is achieved.

Description

Gas imaging continuous zoom lens

Technical Field

The application relates to the technical field of optical machine design, in particular to a gas imaging continuous zoom lens.

Background

The gas leakage is easy to cause accidents, the accidents are easy to cause economic loss, environmental pollution and personal injury, and the life and property safety of people is seriously threatened. How to realize the rapid detection of the leakage of the harmful gas, the accurate positioning of the leakage source position, the reasonable analysis of the spatial distribution and the diffusion trend of the leakage gas, and the prevention of serious gas leakage accidents become the urgent problem to be solved.

The principle of gas imaging is to realize rapid detection of leakage gas and leakage sites according to background absorption gas imaging and infrared radiation absorption technology. When the lens of the thermal imager scans the detection area, once the lens scans the area near the leakage point, due to the higher gas concentration of the area, after infrared rays emitted from targets (pipelines, equipment and the like) pass through the leaked gas, part of radiation is absorbed, the heat radiation energy reaching the focal plane array of the thermal imager is less than that of other pipelines without gas leakage, and the temperature rise of pixels is lower than that of the pipeline sections without gas leakage, so that the detection of the leakage point of the pipeline is realized.

The existing thermal imager lens has the following problems:

1. the whole volume is large, and the requirement of detection on the whole volume of the lens is difficult to meet, for example, an infrared thermal imager disclosed in CN 201710325330.1;

2. when the existing infrared lens is used for gas imaging, the infrared lens is easily influenced by heat radiation generated by other heat radiation objects in a detection environment, meanwhile, the temperature and the humidity of the detection environment cannot be controlled, and the detection result of a gas imaging system and the detection result of an actual leakage point have errors, so that the detection precision is influenced.

Disclosure of Invention

The application provides a gas imaging continuous zoom lens to above-mentioned technical problem, this camera lens compact structure whole small and exquisite, the assembly of being convenient for has high imaging quality, high spatial resolution, compact structure, become doubly and compensate the stroke short, the detection distance is far away, light in weight and shock resistance's performance, the transmission is steady when zooming is used, can eliminate the stray light, introduce aspheric surface and diffraction face type, fully correct the aberration makes optical system theoretical design MTF be close the diffraction limit, the diffuse spot satisfies the detector operation requirement, be favorable to improving the rate of accuracy of gas imaging result.

The application provides a gas imaging continuous zoom lens, include: an optical system and a zoom mechanical assembly; the optical system is accommodated in the zooming mechanical assembly, and the zooming mechanical assembly adjusts the variable interval distance in the optical system;

the optical system includes: the following steps are sequentially arranged from an object image end to an imaging end: a front fixed group lens A with positive focal power, a variable-power group lens B with negative focal power, a first compensation group lens C with positive focal power, a second compensation group lens D with negative focal power, a focusing group lens E with positive focal power and a rear fixed group lens F with positive focal power;

the front fixed group lens A is a positive meniscus lens, the variable-magnification group lens B is a biconcave negative lens, the first compensation group lens C is a biconvex negative lens, the second compensation group lens D is a positive meniscus lens, the focusing group lens is a negative meniscus lens, and the rear fixed group lens F is a positive meniscus lens;

the zoom mechanical assembly includes: zoom subassembly, focusing subassembly, hold and set up in main lens cone: the device comprises a front fixed group, a zoom group, a first compensation component, a second compensation component, a focusing group and a rear fixed group; the front fixed group, the zoom group, the first compensation component, the second compensation component, the focusing group and the rear fixed group are sequentially arranged from the object image end to the object image end of the lens;

the variable magnification subassembly includes: a variable magnification drive assembly, a cam barrel; the zoom driving assembly and the cam cylinder are in driving connection; the cam cylinder is sleeved in the middle of the main lens cylinder and is respectively in driving connection with the variable-magnification group, the first compensation component and the second compensation component;

the focusing assembly includes: a focusing driving assembly and a focusing barrel; the focusing cylinder is inserted on the eye image end of the main lens barrel and is in driving connection with the focusing driving component; the focusing group is accommodated in the focusing cylinder and rotates along with the focusing cylinder;

the second compensation assembly includes: a third lens frame and a fourth pressing ring; the second compensation group lens D is accommodated in the third lens frame and is installed by pressing through a fourth pressing ring; one end face of the third mirror frame is provided with a weight-reducing annular groove, and the other end face of the third mirror frame is provided with a plurality of weight-reducing holes.

Preferably, a variable air interval A1 is arranged between the front fixed group lens A and the variable power group lens B; a variable air interval B1 is arranged between the variable-magnification lens B and the first compensation lens C; a variable air interval C1 is arranged between the first compensation group lens C and the second compensation group lens D; a variable air interval D1 is arranged between the second compensation group lens D and the focusing group lens E; a variable air space E1 is arranged between the focusing group lens E and the rear fixed group lens F.

Preferably, the focusing group includes: the fourth lens frame and the fifth pressing ring are used for accommodating the focusing group lenses E in the fourth lens frame and are pressed in the fourth lens frame through the fifth pressing ring; one end face of the fourth lens frame is provided with a weight-reducing annular groove, and the other end face of the fourth lens frame is provided with a plurality of weight-reducing holes;

the focusing drive assembly includes: focusing motor and focusing gear ring; the focusing motor is arranged outside the main lens cone and is in driving connection with the focusing gear ring; the focusing gear ring is sleeved outside the focusing cylinder and is in driving connection with the focusing cylinder.

Preferably, it comprises: a variable-magnification motor and a variable-magnification gear ring; the zoom motor is arranged outside the main lens barrel and is in driving connection with the zoom gear ring; the zoom gear ring is sleeved on the cam cylinder and is in driving connection with the cam cylinder;

the bore inner diameter of the lightening bore is 5-6 mm; 10 to 12 lightening holes are uniformly distributed around the central shaft of the third mirror frame; the weight reducing holes are uniformly distributed 15-20 around the central shaft of the fourth lens frame.

Preferably, the included angle formed by the connecting line of the circle centers of any two adjacent lightening holes and the circle center of the third glasses frame is 20-30 degrees; the included angle formed by the connecting line of the circle centers of any two adjacent lightening holes and the circle center of the fourth glasses frame is 12-15 degrees.

Preferably, the front fixation group comprises: a first clamping ring; the front fixed group lens A is accommodated in the object image end of the main lens cone and is installed in a compressing mode through the first pressing ring.

Preferably, the variable magnification group includes: a first mirror frame and a second pressing ring; the first lens frame is accommodated and arranged in the main lens barrel; the variable-magnification lens B is accommodated in the first lens frame and is installed in the first lens frame in a pressing mode through the second pressing ring.

Preferably, the first compensation assembly comprises: a second mirror frame and a third pressing ring; the second mirror frame is accommodated and arranged in the main mirror cylinder; the first compensation group lens C is accommodated in the second lens frame and installed in the second lens frame in a pressing mode through the third pressing ring.

Preferably, the aspect ratio of the first frame, the second frame, the third frame, and the fourth frame is 2 to 1:1.

preferably, the front fixed group lens a comprises: a surface S1 and a surface S2, wherein the curvature radius of the surface S1 is 90-100 mm; the curvature radius of the surface S2 is 200-300 mm; the variable power lens B comprises: a surface S3 and a surface S4, wherein the curvature radius of the surface S3 is 140-150 mm; the curvature radius of the surface S4 is 120-130 mm; the first compensation group lens C includes: a surface S5 and a surface S6, wherein the curvature radius of the surface S5 is 140-150 mm; the curvature radius of the surface S6 is 120-125 mm; the second compensation group lens D includes: a surface S7 and a surface S8, wherein the curvature radius of the surface S7 is 20-40 mm; the curvature radius of the surface S8 is 20-30 mm; the focusing group lens E includes: a surface S9 and a surface S10, wherein the curvature radius of the surface S9 is 20-30 mm; the radius of curvature of the surface S10 is 30-40 mm; the rear fixed group lens F comprises: a surface S11 and a surface S12, wherein the radius of curvature of the surface S11 is 50-60 mm; the radius of curvature of the surface S12 is 90 to 100mm.

The beneficial effects that this application can produce include:

1) The gas imaging continuous zoom lens is used for being arranged in a mechanical assembly of an optical system, and is respectively designed for the main lens barrel, the cam barrel and the lens frame in a light-weight mode, so that the total mass of the lens is effectively reduced, and the design effect of compact structure is achieved. And optimally designing the length-diameter ratio of the mirror frame, the position of the lens and the depth of the guide pin. The main lens cone and the lens frame are subjected to extinction thread structural design, so that certain stray light is effectively eliminated.

Drawings

FIG. 1 is a schematic diagram of an optical lens structure of a gas imaging continuous zoom lens provided by the present application;

FIG. 2 is a schematic diagram of a front cross-sectional structure of a gas imaging continuous zoom lens provided by the present application;

FIG. 3 is an end view schematic diagram of a gas imaging continuous zoom lens provided by the present application;

FIG. 4 is a schematic view of the cross-sectional structure A in FIG. 3;

FIG. 5 is a schematic perspective view of a main lens barrel provided in the present application;

fig. 6 is a schematic perspective view of a zoom lens barrel according to the present disclosure;

fig. 7 is a schematic perspective view of a focusing barrel provided in the present application;

fig. 8 is a schematic diagram of an end face perspective structure of a third first lens frame provided in the present application;

fig. 9 is a schematic perspective view of another end surface of the third lens frame provided in the present application;

fig. 10 is a schematic diagram of an end face perspective structure of a fourth first lens frame provided in the present application;

fig. 11 is a schematic perspective view of another end surface of the fourth lens frame provided in the present application;

fig. 12 is a schematic diagram of curve movement amounts of a zoom cam groove, a first compensation cam groove, and a second compensation cam groove in a zoom movement of a gas imaging continuous zoom lens in the embodiment of the present application;

legend description:

1. a first clamping ring; 2. a main barrel; 5. a variable-magnification gear ring; 10. a motor base; 11. a variable-magnification motor; 12. a cam cylinder; 14. a focusing barrel; 15. a rear mirror cover; 17. a fifth mirror frame; 19. a sixth pressing ring; 20. a fifth clamping ring; 21. a fourth lens frame; 22. a fourth clamping ring; 23. a third mirror frame; 25. a third clamping ring; 26. a second mirror frame; 27. a first mirror frame; 28. a second clamping ring; 30. a front lens cover; 37. focusing gear ring; 39. a focusing motor;

211. a zoom cam groove; 212. a first compensation cam groove; 213. a second compensation cam groove; 214. a zoom guide groove; 215. a first compensation guide groove; 216. a second compensation guide groove; 217. focusing guide groove; 141. focusing curve groove; 232. a lightening hole; 231. a weight-reducing annular groove;

A. a front fixed group of lenses; a1, air interval; B. variable power group lens; b1, air interval; C. a first compensation group lens; c1, air interval; D. a second compensation group lens; d1, air interval; E. focusing group lenses; F. and (3) fixing the lens group.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the embodiments of the present utility model more apparent, the technical solutions of the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model, and it is apparent that the described embodiments are some embodiments of the present utility model, but not all embodiments. The components of the embodiments of the present utility model generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.

Thus, the following detailed description of the embodiments of the utility model, as presented in the figures, is not intended to limit the scope of the utility model, as claimed, but is merely representative of selected embodiments of the utility model. All other embodiments, based on the embodiments of the utility model, which are apparent to those of ordinary skill in the art without inventive faculty, are intended to be within the scope of the utility model.

Technical means which are not described in detail in the application and are not used for solving the technical problems of the application are all arranged according to common general knowledge in the field, and various common general knowledge arrangement modes can be realized.

Referring to fig. 1, the gas imaging continuous zoom lens provided in the present application includes: an optical system and a zoom mechanical assembly; the optical system is accommodated in the zooming mechanical assembly, and the zooming mechanical assembly adjusts the variable interval distance in the optical system;

the optical system includes: the following steps are sequentially arranged from an object image end to an imaging end: a front fixed group lens A with positive focal power, a variable-power group lens B with negative focal power, a first compensation group lens C with positive focal power, a second compensation group lens D with negative focal power, a focusing group lens E with positive focal power and a rear fixed group lens F with positive focal power;

the front fixed group lens A is a positive meniscus lens, the variable-magnification group lens B is a biconcave negative lens, the first compensation group lens C is a biconvex negative lens, the second compensation group lens D is a positive meniscus lens, the focusing group lens is a negative meniscus lens, and the rear fixed group lens F is a positive meniscus lens.

In order to suppress stray radiation from outside the scene radiation in the optical system, 100% cold stop efficiency is employed, and for a refrigerated infrared optical system, the cold stop of the detector should be used as the exit pupil of the optical system to achieve 100% cold stop efficiency. Therefore, the continuous zooming system adopts a secondary imaging structure, and can reduce the radial size of the system while ensuring the 100% cold diaphragm efficiency. In order to avoid affecting the comprehensive performance of the optical system, the optical system can realize the effective combination of the characteristics of infrared materials, such as larger absorption compared with visible light materials and higher refractive index.

In order to fully eliminate the system phase difference, correct the image plane drift and improve the detection precision of the gas leakage point, preferably, the material of the front fixed group lens A is Ge; the material of the variable-magnification lens B is Si; the material of the first compensation group lens C is Ge; the material of the second compensation group lens D is Si; the focusing group lens E is made of Ge; the material of the rear fixed group lens F is Ge.

The temperature sensitivity of each lens used in the optical system is improved, the influence of the detected environmental temperature change on the system is considered, si is selected as a main material of the zoom group, and other lenses mainly select Ge to correct chromatic aberration.

Preferably, the variable-magnification lens B is a biconcave negative lens, and the rear end surface of the biconcave negative lens is an aspheric surface;

preferably, the first compensation group lens C is a biconvex negative lens, and the rear end surface of the biconvex negative lens is an aspheric surface;

preferably, the second compensation lens group D is a positive meniscus lens, and a rear end face of the positive meniscus lens is an aspherical surface.

The lenses B-D are arranged in the mode to optimize the cold reflection image, so that the specular reflection ghost image and the cold reflection black spot are far away from the image surface of the detector.

Preferably, the aspherical surfaces of the variable power lens B, the first compensation lens C and the second compensation lens D satisfy the following formula:

wherein Z is the distance vector height from the vertex of the aspheric surface when the aspheric surface is at the position with the height r along the optical axis direction; r is the height of the aspheric surface in the direction perpendicular to the optical axis; c=1/R, R representing the paraxial radius of curvature of the mirror; k is a conical coefficient; A. b, C, D is a higher order aspheric coefficient.

By arranging the aspheric surface on the rear end face of the lens, the purpose of balancing the aberration of the system is achieved, the structure of the optical system is simplified, the imaging quality is better, and the detection accuracy of the gas imaging result is improved.

Preferably, the front fixed group lens a comprises: a surface S1 and a surface S2, wherein the curvature radius of the surface S1 is 90-100 mm; the curvature radius of the surface S2 is 200-300 mm; the variable power lens B comprises: a surface S3 and a surface S4, wherein the curvature radius of the surface S3 is 140-150 mm; the curvature radius of the surface S4 is 120-130 mm; the first compensation group lens C includes: a surface S5 and a surface S6, wherein the curvature radius of the surface S5 is 140-150 mm; the curvature radius of the surface S6 is 120-125 mm; the second compensation group lens D includes: a surface S7 and a surface S8, wherein the curvature radius of the surface S7 is 20-40 mm; the curvature radius of the surface S8 is 20-30 mm; the focusing group lens E includes: a surface S9 and a surface S10, wherein the curvature radius of the surface S9 is 20-30 mm; the radius of curvature of the surface S10 is 30-40 mm; the rear fixed group lens F comprises: a surface S11 and a surface S12, wherein the radius of curvature of the surface S11 is 50-60 mm; the radius of curvature of the surface S12 is 90 to 100mm.

Preferably, a variable air interval A1 is arranged between the front fixed group lens A and the variable power group lens B; a variable air interval B1 is arranged between the variable-magnification lens B and the first compensation lens C; a variable air interval C1 is arranged between the first compensation group lens C and the second compensation group lens D; a variable air interval D1 is arranged between the second compensation group lens D and the focusing group lens E; a variable air space E1 is arranged between the focusing group lens E and the rear fixed group lens F.

Specifically, specific parameters of each lens are as follows:

the upper surface is numbered with the serial number of any two opposite surfaces of each lens. The radius of curvature in the table above refers to the radius of curvature of each surface, and the air space refers to the distance between two adjacent surfaces, for example, the air space corresponding to the surface S1 is the distance between the surface S1 and the surface S2 is the thickness of the front fixed group lens a.

Preferably, the aspherical coefficient of the rear end face of the variable power group lens B is k=0; a= 7.324E-009; b= -4.556E-012; c= 1.256E-015; d=0; the aspheric coefficient of the rear end face of the first compensation group lens C is k=0; a= 2.215E-006; b= 2.665E-008; c= -2.223E-010; d=0; the aspheric coefficient of the rear end face of the second compensation group lens D is k=0; a= 3.112E-005; b=2.554E-007; c= -5.32E-009; d= -2.331E-0011.

In a specific embodiment, the aspherical coefficients of the surfaces S4, S6, S8, the aspherical data are shown in the following table:

preferably, the rear surface of the rear fixed group lens F is a surface S12, and the diffraction surface coefficient is: the first-order diffraction coefficient is 4.023E-004; the diffraction second order coefficient is-6.964E-07; the surface wavelength was 3000nm.

The following table is the diffraction plane coefficients of surface S12:

surface of the body	Plane wavelength	C1	C2
				S12	3000nm	4.023E-004	-6.964E-07

Wherein, C1: diffraction first order coefficients; c2: diffraction second order coefficients;

the optical system assembled according to the parameters achieves the following optical indexes:

(1) Focal length: f=30-75 mm, the transformation ratio is 2.5 times;

(2) Field angle range: 19.2 degrees x 15.3 degrees to 8.3 degrees x 5.2 degrees;

(3) Relative pore size: 1.2;

(4) Adapting the detector: the method is suitable for a refrigeration type medium wave infrared detector with a target surface of 320 x 256 and a pixel size of 30 mu m;

(5) Operating temperature: -30 to +60 ℃;

(6) The applicable spectral line range: 3 μm to 3.6 μm.

Referring to fig. 2 to 11, the zoom mechanical assembly specifically used includes a lens barrel accommodated in a main body barrel: the device comprises a front fixed group, a variable magnification group, a first compensation component, a second compensation component, a focusing group and a rear fixed group.

The front fixed group includes: the first clamping ring 1 is used for installing the front fixed group lens A at the front end of the main lens barrel 2 and fixedly clamping and installing the front fixed group lens A through the first clamping ring 1.

The variable-magnification group comprises: a variable power group lens B, a first mirror frame 27 and a second clamping ring 28. The variable power group lens B is mounted in the first frame 27 and is fixed and compressively mounted by the second clamping ring 28.

The first compensation assembly includes: a first compensation group of lenses C, a second frame 26 and a third clamping ring 25. The first compensation group lens C is mounted in the second frame 26 and is fixed and compressively mounted by the third clamping ring 25.

The second compensation assembly includes: a second compensation group lens D, a third lens frame 23 and a fourth clamping ring 22. The second compensation group lens D is mounted in the third frame 23 and is fixed and compressively mounted by the fourth clamping ring 22.

The focusing group includes: a focusing group lens E, a fourth lens frame 21 and a fifth pressing ring 20. The focusing group lens E is mounted in the fourth frame 21 and is fixed and press-mounted by the fifth press ring 20.

The rear fixed group of lenses F, the fifth frame 17 and the sixth clamping ring 19 constitute a rear fixed group. The rear fixed group of lenses F is mounted in the fifth frame 17 and is fixed and compressively mounted by the sixth clamping ring 19.

The zoom group, the first compensation component, the second compensation component, the focusing group and the rear fixed group are sequentially arranged in the main lens barrel 2 from the object image end to the object image end of the lens.

The outer wall of the main lens barrel 2 is provided with a zoom guide groove 214, a first compensation guide groove 215, a second compensation guide groove 216 and a focusing guide groove 217, the main lens barrel 2 is sleeved with the cam barrel 12, the outer surface of the cam barrel 12 is provided with a zoom cam groove 211, a first compensation cam groove 212 and a second compensation cam groove 213, and the zoom guide groove 214 is aligned with the zoom cam groove 211; first compensating guide slot 215 is disposed in alignment with first compensating cam slot 212; the second compensation guide groove 216 is disposed in alignment with the second compensation cam groove 213. A plurality of bearing sets are provided outside the cam barrel 12. The bearing groups extend from the variable-magnification cam groove 211, the first compensation cam groove 212, and the second compensation cam groove 213 into the variable-magnification guide groove 214, the first compensation guide groove 215, and the second compensation cam groove 216, respectively, in this order, and connect the variable-magnification groups, the first compensation member, and the second compensation member, respectively.

The motor base 10 is arranged on the outer side wall of the main lens barrel 2; the motor seat 10 is provided with a variable-magnification motor 11, the motor gear 8 is in driving connection with the variable-magnification motor 11, and the motor gear 8 is sleeved on the cam cylinder 12; when the rotor of the variable-magnification motor 11 rotates, the motor gear 8 and the variable-magnification gear ring 5 drive the cam cylinder 12 to rotate, the cam cylinder 12 transmits the motion to the first lens frame 27, the second lens frame 26 and the third lens frame 23 through the bearing group, and the first lens frame 27, the second lens frame 26 and the third lens frame 23 convert the rotation of the cam cylinder 12 into the parallel movement of the first lens frame 27, the second lens frame 26 and the third lens frame 23 along the optical axis direction under the limit action of the guide straight groove, so that the zooming motion is realized.

In a specific embodiment, a weight-reducing annular groove 231 is arranged on one end face of the third lens frame 23, a plurality of weight-reducing holes 232 are arranged on the other end face, the inner diameter of each weight-reducing hole 232 is 5-6 mm, 10-12 holes are uniformly distributed around the central axis of the weight-reducing annular groove 231, and an included angle formed by connecting the circle center of each weight-reducing hole 232 adjacent to Ren Liangxiang with the circle center of the third lens frame 23 or the circle center of the weight-reducing annular groove 231 is 20-30 degrees, so that the weight of the lens frame is reduced while the strength of the lens frame is ensured.

Further comprises: a focusing barrel 14; the focusing cylinder 14 is rotatably arranged at the 2-mesh image end of the main lens cone; a focusing guide slot 217 is arranged on the 2-mesh image end of the main lens cone; a focusing curve groove 141 is provided on the focusing barrel 14. The bearing group is inserted into the focusing guide slot 217 from the focusing curved slot 141.

In the present embodiment, a focus motor 39 is mounted on the motor mount 10. The focusing motor 39 is in driving connection with a focusing gear ring 37 arranged on the focusing cylinder 14; the motor gear is connected with the focusing barrel 14. When the focusing motor 39 drives the focusing cylinder 14 to rotate in a focusing way, the focusing cylinder transmits the movement to the fourth lens frame 21 through the bearing group, and the fourth lens frame 21 converts the rotary movement of the focusing cylinder 14 into the parallel movement of the fourth lens frame 21 along the optical axis direction under the limit action of the guide straight groove, so that the focusing of the lens is realized.

In a specific embodiment, a weight-reducing annular groove 231 and a plurality of weight-reducing holes 232 are arranged on one end face of the fourth lens frame 21, the inner diameter of each weight-reducing hole 232 is 5-6 mm, 15-20 weight-reducing holes 232 are uniformly distributed around the central shaft of the fourth lens frame 21 at equal intervals, and the included angle between the connecting line between the circle center of any two adjacent weight-reducing holes 232 and the circle center of the fourth lens frame 21 is 12-15 degrees, so that the lens frame strength is ensured and the light weight of the lens frame is realized.

In the embodiment, the stop of the zoom motor 11 at the long focus and short focus end points is realized by triggering the limit switch contacts through the limiting block fixed on the cam cylinder 12. The automatic stopping action of the focusing motor 39 at the front and rear focusing end points is realized by touching the contacts of the miniature limit switch through limit posts arranged on the focusing cylinder 14.

In one embodiment, the front lens cover 30 is covered on the object-image end of the main lens barrel 2; a rear mirror cover 15 is provided on the image end of the focusing barrel 14.

When the long-wave infrared continuous zoom lens is used, light rays sequentially pass through the front fixed group lens A, the variable-magnification group lens B, the first compensation group lens C, the second compensation group lens D, the focusing group lens E and the rear fixed group lens F to form images.

The zoom motor 11 drives the cam cylinder 12 to rotate, and the bearing group drives the first lens frame 27, the second lens frame 26 and the third lens frame 23 to move back and forth along the axial direction of the lens barrel respectively, so that the zoom lens B, the first compensation lens C and the second compensation lens D move back and forth, the air interval is adjusted, and the zoom is realized; the focusing motor 39 drives the focusing cylinder 14 to rotate, and the bearing group drives the fifth lens frame 17 to move back and forth to perform focusing; the zoom and the focusing are combined to realize the electric zooming of the lens.

The aspect ratio of the first frame 27, the second frame 26, the third frame 23 and the fourth frame 21 is 2 to 1:1, the lens position is located in the center of the lens frame, the depth of the guide nails is 0.5mm, the offset between the lens frames is within 0.1mm, and the offset is within 0.05 degrees.

FIG. 12 is a graph showing the amount of movement of the cam profile of the zoom lens according to the embodiment; the horizontal axis is the number of optical design points, which is 793 points in total; the vertical axis is a groove line movement amount, in which curve 1 corresponds to the groove line movement amount of the zoom cam groove 211; curve 2 corresponds to the amount of wire movement of first compensating cam slot 212; curve 3 corresponds to the amount of slot line movement of the second compensation cam slot 213. According to the image, the lens provided by the application can perform zoom and focusing movements, and imaging is achieved.

The lens adaptation related module is used for gas imaging, and more than 50 dangerous chemical gas imaging can be realized. The application provides the camera lens to danger chemical gas detection kind more, is higher than other money camera lenses in the market. The lens is not only suitable for a handheld complete machine, but also is convenient for inspection personnel to check and repair the money so as to avoid danger and loss. But also can be arranged in an online monitoring whole machine of gas, and the real-time monitoring realizes digital control and detection.

Although the present utility model has been described with reference to the foregoing embodiments, it will be apparent to those skilled in the art that modifications may be made to the embodiments described, or equivalents may be substituted for elements thereof, and any modifications, equivalents, improvements and changes may be made without departing from the spirit and principles of the present utility model.

Claims (10)

1. A gas imaging continuous zoom lens, comprising: an optical system and a zoom mechanical assembly; the optical system is accommodated in the zooming mechanical assembly, and the zooming mechanical assembly adjusts the variable interval distance in the optical system;

the optical system includes: the following steps are sequentially arranged from an object image end to an imaging end: a front fixed group lens A with positive focal power, a variable-power group lens B with negative focal power, a first compensation group lens C with positive focal power, a second compensation group lens D with negative focal power, a focusing group lens E with positive focal power and a rear fixed group lens F with positive focal power;

the front fixed group lens A is a positive meniscus lens, the variable-magnification group lens B is a biconcave negative lens, the first compensation group lens C is a biconvex negative lens, the second compensation group lens D is a positive meniscus lens, the focusing group lens is a negative meniscus lens, and the rear fixed group lens F is a positive meniscus lens;

the zoom mechanical assembly includes: zoom subassembly, focusing subassembly, hold and set up in main lens cone: the device comprises a front fixed group, a zoom group, a first compensation component, a second compensation component, a focusing group and a rear fixed group; the front fixed group, the zoom group, the first compensation component, the second compensation component, the focusing group and the rear fixed group are sequentially arranged from the object image end to the object image end of the lens;

the variable magnification subassembly includes: a variable magnification drive assembly, a cam barrel; the zoom driving assembly and the cam cylinder are in driving connection; the cam cylinder is sleeved in the middle of the main lens cylinder and is respectively in driving connection with the variable-magnification group, the first compensation component and the second compensation component;

the focusing assembly includes: a focusing driving assembly and a focusing barrel; the focusing cylinder is inserted on the eye image end of the main lens barrel and is in driving connection with the focusing driving component; the focusing group is accommodated in the focusing cylinder and rotates along with the focusing cylinder;

the second compensation assembly includes: a third lens frame and a fourth pressing ring; the second compensation group lens D is accommodated in the third lens frame and is installed by pressing through a fourth pressing ring; one end face of the third mirror frame is provided with a weight-reducing annular groove, and the other end face of the third mirror frame is provided with a plurality of weight-reducing holes.

2. The gas imaging continuous zoom lens according to claim 1, wherein a variable air space A1 is provided between the front fixed group lens a and the variable magnification group lens B; a variable air interval B1 is arranged between the variable-magnification lens B and the first compensation lens C; a variable air interval C1 is arranged between the first compensation group lens C and the second compensation group lens D; a variable air interval D1 is arranged between the second compensation group lens D and the focusing group lens E; a variable air space E1 is arranged between the focusing group lens E and the rear fixed group lens F.

3. The gas imaging continuous zoom lens of claim 1, wherein the focusing group comprises: the fourth lens frame and the fifth pressing ring are used for accommodating the focusing group lenses E in the fourth lens frame and are pressed in the fourth lens frame through the fifth pressing ring; one end face of the fourth lens frame is provided with a weight-reducing annular groove, and the other end face of the fourth lens frame is provided with a plurality of weight-reducing holes;

the focusing drive assembly includes: focusing motor and focusing gear ring; the focusing motor is arranged outside the main lens cone and is in driving connection with the focusing gear ring; the focusing gear ring is sleeved outside the focusing cylinder and is in driving connection with the focusing cylinder.

4. A gas imaging continuous zoom lens according to claim 1 or 3, comprising: a variable-magnification motor and a variable-magnification gear ring; the zoom motor is arranged outside the main lens barrel and is in driving connection with the zoom gear ring; the zoom gear ring is sleeved on the cam cylinder and is in driving connection with the cam cylinder;

the bore inner diameter of the lightening bore is 5-6 mm; 10 to 12 lightening holes are uniformly distributed around the central shaft of the third mirror frame; the weight reducing holes are uniformly distributed 15-20 around the central shaft of the fourth lens frame.

5. A gas imaging continuous zoom lens according to claim 1 or 3, wherein the included angle formed by the connecting line of the circle center of any two adjacent lightening holes and the circle center of the third lens frame is 20-30 degrees; the included angle formed by the connecting line of the circle centers of any two adjacent lightening holes and the circle center of the fourth glasses frame is 12-15 degrees.

6. The gas imaging progressive lens of claim 1, wherein the front fixed group comprises: a first clamping ring; the front fixed group lens A is accommodated in the object image end of the main lens cone and is installed in a compressing mode through the first pressing ring.

7. The gas imaging progressive lens of claim 6, wherein the variable magnification group comprises: a first mirror frame and a second pressing ring; the first lens frame is accommodated and arranged in the main lens barrel; the variable-magnification lens B is accommodated in the first lens frame and is installed in the first lens frame in a pressing mode through the second pressing ring.

8. The gas imaging progressive lens of claim 7, wherein the first compensation assembly comprises: a second mirror frame and a third pressing ring; the second mirror frame is accommodated and arranged in the main mirror cylinder; the first compensation group lens C is accommodated in the second lens frame and installed in the second lens frame in a pressing mode through the third pressing ring.

9. The gas imaging continuous zoom lens of claim 8, wherein the first, second, third, and fourth frames have an aspect ratio of 2 to 1:1.

10. the gas imaging progressive lens of claim 1, wherein the front fixed group lens a comprises: a surface S1 and a surface S2, wherein the curvature radius of the surface S1 is 90-100 mm; the curvature radius of the surface S2 is 200-300 mm; the variable power lens B comprises: a surface S3 and a surface S4, wherein the curvature radius of the surface S3 is 140-150 mm; the curvature radius of the surface S4 is 120-130 mm; the first compensation group lens C includes: a surface S5 and a surface S6, wherein the curvature radius of the surface S5 is 140-150 mm; the curvature radius of the surface S6 is 120-125 mm; the second compensation group lens D includes: a surface S7 and a surface S8, wherein the curvature radius of the surface S7 is 20-40 mm; the curvature radius of the surface S8 is 20-30 mm; the focusing group lens E includes: a surface S9 and a surface S10, wherein the curvature radius of the surface S9 is 20-30 mm; the radius of curvature of the surface S10 is 30-40 mm; the rear fixed group lens F comprises: a surface S11 and a surface S12, wherein the radius of curvature of the surface S11 is 50-60 mm; the radius of curvature of the surface S12 is 90 to 100mm.