Three-group zoom mid-wave refrigeration turnaround lens

Abstract

The present application relates to a kind of three groups variable magnification mid-wave refrigeration return mirror, the optical system of lens is composed of front fixed mirror group, variable magnification mirror group, focusing mirror group, mirror group and rear fixed mirror group, front fixed mirror group is positive lens A;Variable magnification mirror group is composed of negative lens B, positive lens C and negative lens D;Focusing mirror group is positive lens E;Mirror group is composed of mirror J and mirror K, mirror J and mirror K are reflected twice, and light direction is reversed 180°;Rear fixed mirror group is composed of positive lens F and negative lens G.The present application realizes maximum focal length 500mm, can be tracked to long distance, super long distance and high speed movement etc.Target;Realize minimum focal length 22.5mm, larger field angle can realize large area scanning search, can be applied to the demand scene such as exploration, tracking, imaging guidance etc.;Mid-wave infrared temperature imaging system has clearer imaging and higher contrast than longer wave lens, can better adapt to forest fire prevention, border and sea defense etc.Application.

Description

TECHNICAL FIELD

[0002] The application belongs to the technical field of lenses, and particularly relates to a three-group variable magnification mid-wave refrigeration return lens. BACKGROUND

[0004] In an infrared imaging system, an optical system with continuous zooming function has greater advantages in practical application scenarios such as remote sensing, early warning, reconnaissance observation, imaging guidance, compared with a traditional single field of view optical system. The optical system can search for targets in a large space range at a large field of view, and can detect, identify, track and aim at the searched targets at a small field of view. A mid-wave refrigeration system can keep a low-temperature state of a machine core to run and better discharge temperature interference, so that imaging has higher sharpness and contrast. SUMMARY

[0006] The application aims to provide a three-group variable magnification mid-wave refrigeration return lens.

[0007] In order to achieve the above-mentioned purpose, the technical scheme adopted by the application is as follows: a three-group variable magnification mid-wave refrigeration return lens, an optical system of the lens is composed of a front fixed lens group, a variable magnification lens group, a focusing lens group, a reflecting lens group and a rear fixed lens group which are sequentially arranged along an incident light path of light rays, the front fixed lens group is a positive lens A; the variable magnification lens group is composed of a negative lens B, a positive lens C and a negative lens D which are sequentially arranged along the incident light path of the light rays; the focusing lens group is a positive lens E; the reflecting lens group is composed of a reflecting mirror J and a reflecting mirror K which are sequentially arranged along the incident light path of the light rays, the reflecting mirror J and the reflecting mirror K reflect the light rays twice to reverse the direction of the light rays by 180°; and the rear fixed lens group is composed of a positive lens F and a negative lens G which are sequentially arranged along the incident light path of the light rays.

[0008] Further, an air gap between the positive lens A and the negative lens B is 45mm-95mm, an air gap between the negative lens B and the positive lens C is 3mm-101.4mm, an air gap between the positive lens C and the negative lens D is 12.96mm-51.34mm, an air gap between the negative lens D and the positive lens E is 23.8mm-45.44mm, an air gap between the positive lens E and the positive lens F is 108mm, and an air gap between the positive lens F and the negative lens G is 3mm.

[0009] Further, the focal length of the optical system is f, and the focal lengths of the positive lens A, the negative lens B, the positive lens C, the negative lens D, the positive lens E, the positive lens F and the negative lens G are f1, f2, f3, f4, f5, f6 and f7 respectively, wherein f1, f2, f3, f4, f5, f6 and f7 satisfy the following ratios: 0 < f1 / f < 7, -1 < f2 / f < 0, 0 < f3 / f < 2, -1 < f4 / f < 0, 0 < f5 / f < 4, 0 < f6 / f < 1 and -2 < f7 / f < 0.

[0010] Further, the lens further comprises a main lens barrel, an electric zoom mechanism and an electric focusing mechanism, the front fixed lens group, the variable magnification lens group and the focusing lens group are arranged inside the main lens barrel, the electric zoom mechanism drives the variable magnification lens group to move to realize continuous zooming of the lens focal length of 22.5-500mm, and the electric focusing mechanism drives the focusing lens group to move to realize lens focusing.

[0011] Further, the positive lens A is arranged inside the front end of the main lens barrel and is fixed by an A piece pressing ring, and an A piece adjusting gasket is arranged at the rear side of the positive lens A to realize adjustment of the air gap between the positive lens A and the negative lens B.

[0012] Further, the main lens barrel is sequentially provided with a variable magnification slide I, a variable magnification slide II and a variable magnification slide III along the light path of light incidence, the variable magnification slide I, the variable magnification slide II and the variable magnification slide III are respectively provided with a B piece lens seat, a C piece lens seat and a D piece lens seat, the negative lens B is arranged on the B piece lens seat and is fixed by a B piece pressing ring, the positive lens C is arranged on the C piece lens seat and is fixed by a C piece pressing ring, and the negative lens D is arranged on the D piece lens seat and is fixed by a D piece pressing ring.

[0013] Further, the electric zoom mechanism comprises a first micro switch, a variable magnification motor frame arranged above the main lens barrel and a variable magnification motor installed on the variable magnification motor frame, a variable magnification motor gear is arranged at the output end of the variable magnification motor, a variable magnification cam is arranged outside the main lens barrel to engage with the variable magnification motor gear, the variable magnification cam has three variable magnification cam grooves, three variable magnification cam guide nails are arranged in the three variable magnification cam grooves respectively, and the three variable magnification cam guide nails at the corresponding positions are connected with the variable magnification slide I, the variable magnification slide II and the variable magnification slide III respectively, and the variable magnification cam drives the variable magnification slide I, the variable magnification slide II and the variable magnification slide III to move simultaneously when the variable magnification cam rotates, and the variable magnification cam is limited by a variable magnification cam pressing ring.

[0014] Further, the rear end of the main lens barrel is provided with a focusing slide, the focusing slide is provided with a focusing lens seat, and the positive lens E is arranged on the focusing lens seat and is fixed by an E piece pressing ring.

[0015] Further, the electric focusing mechanism comprises a second micro switch, a focusing motor rack arranged on the main lens barrel and a focusing motor installed on the focusing motor rack, a focusing motor gear is arranged at an output end of the focusing motor, a focusing cam is arranged outside the main lens barrel and is used for engaging with the focusing motor gear, the focusing cam is provided with a focusing cam groove, and a focusing cam guide pin is arranged in the focusing cam groove, and the focusing cam guide pin at the corresponding position is connected with the focusing slide.

[0016] Compared with the prior art, the present application has the following effects: the present application has reasonable design, realizes a maximum focal length of 500mm, can track targets at long distance, super long distance and high speed, realizes a minimum focal length of 22.5mm, a larger field angle can realize large-area scanning and searching, and can be applied to demand scenes such as exploration, tracking and imaging guidance; the temperature imaging system of the middle-wave infrared has clearer imaging and higher contrast than the long-wave lens, and can better adapt to applications such as forest fire prevention and border and sea defense. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 is an optical structure schematic diagram of the embodiment of the present application;

[0019] Figure 2 is a main view cross-sectional structure schematic diagram of the embodiment of the present application;

[0020] Figure 3 is a three-dimensional structure schematic diagram of the embodiment of the present application.

[0021] IN THE DRAWINGS:

[0022] A- positive lens A; B- negative lens B; C- positive lens C; D- negative lens D; E- positive lens E; J- reflecting mirror J; K- reflecting mirror K; F- positive lens F; G- negative lens G; 101- A piece of compression ring; 102- A piece of adjusting gasket; 103- main lens barrel; 104- B piece of lens seat; 105- B piece of compression ring; 106- variable magnification slide I; 107- guide pin; 108- variable magnification slide II; 109- variable magnification cam; 110- C piece of compression ring; 111- C piece of lens seat; 112- variable magnification cam compression ring; 113- variable magnification slide III; 114- D piece of lens seat; 115- focusing cam; 116- focusing cam compression ring; 117- D piece of compression ring; 118- focusing lens seat; 119- E piece of compression ring; 120- J piece of compression ring; 121- J piece of lens seat; 122- turning seat; 123- K piece of lens seat; 124- K piece of compression ring; 125- FG spacer ring; 126- G piece of compression ring; 132- first motor; 133- variable magnification switch rack; 134- first micro switch; 135- second motor; 138- second motor gear; 140- second micro switch; 141- second motor rack; 143- variable magnification motor; 144- variable magnification motor rack; 145- variable magnification motor gear; 146- first motor gear. Detailed implementation method:

[0024] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0025] like Figure 1 As shown, this invention discloses a three-group zoom mid-wave cooled folding lens, designed to achieve continuous zoom imaging from a minimum focal length of 22.5mm to a maximum focal length of 500mm. The optical system of the lens consists of a front fixed lens group, a zoom lens group, a focusing lens group, a reflecting lens group, and a rear fixed lens group arranged sequentially along the incident light path. The front fixed lens group is a positive lens A; the zoom lens group consists of a negative lens B, a positive lens C, and a negative lens D arranged sequentially along the incident light path; the focusing lens group is a positive lens E; the reflecting lens group consists of reflecting mirrors J and K arranged sequentially along the incident light path. Reflecting mirrors J and K each perform one light reflection, achieving a 90° reversal in the direction of light propagation. The two reflections by reflecting mirrors J and K reverse the direction of the light emitted from the focusing lens group by 180° so that it enters the rear fixed lens group; the rear fixed lens group consists of a positive lens F and a negative lens G arranged sequentially along the incident light path.

[0026] In this embodiment, the air gap between the positive lens A and the negative lens B is 45mm-95mm, the air gap between the negative lens B and the positive lens C is 3mm-101.4mm, the air gap between the positive lens C and the negative lens D is 12.96mm-51.34mm, the air gap between the negative lens D and the positive lens E is 23.8mm-45.44mm, the air gap between the positive lens E and the positive lens F is 108mm, and the air gap between the positive lens F and the negative lens G is 3mm.

[0027] In this embodiment, the focal length of the optical system is f, and the focal lengths of the positive lens A, negative lens B, positive lens C, negative lens D, positive lens E, positive lens F, and negative lens G are f1, f2, f3, f4, f5, f6, f7, and f8, respectively. The ratios of f1, f2, f3, f4, f5, f6, f7, and f to f satisfy the following ratio: 0 <f1 / f<7,-1<f2 / f<0,0<f3 / f<2,-1<f4 / f<0,0<f5 / f<4,0<f6 / f<1,-2<f7 / f<0。

[0028] In this embodiment, during imaging: light passes sequentially through positive lens A, negative lens B, positive lens C, negative lens D, positive lens E, reflecting mirror J, reflecting mirror K, positive lens F, and negative lens G to form an image.

[0029] In this embodiment, the lens parameters of positive lens A, negative lens B, positive lens C, negative lens D, positive lens E, positive lens F and negative lens G are shown in Table 1 below.

[0030]

[0031]

[0032] Table 1

[0033] As shown in Table 1, where the radius of curvature is positive, the center of the surface is on the side of the imaging surface, and vice versa. The aspherical surface equation involved in the table is as follows:

[0034]

[0035] The specific parameters of the aspherical surface part shown in Table 1 are as follows:

[0036] Where S3 is the aspherical surface + binary surface: c=1 / R, R=-133.347, k=0, A0=0, A1=1.3029051E-06, A2=-1.347079E-09, A3=4.1446407E-12, A4=-7.9366461E-15, A5=6.3873657E-18;

[0037] The binary surface diffraction order M=1, the planning radius R=20mm, the step depth=1.322316235um, the quadratic coefficient=-15.438773; the quartic coefficient=-6.3367746; the diffraction ring band is 3, respectively r 1= 11.91959, r 2= 16.047649, r 3= 18.903473;

[0038] Where S6 is an aspherical surface: c=1 / R, R=-119.984, k=0, A0=0, A1=1.1487024E-06, A2=-5.8870713E-10, A3=1.2406116E-12, A4=-1.9655928E-15, A5=1.443959E-18;

[0039] Where S7 is an aspherical surface: c=1 / R, R=-24.896, k=0, A0=0, A1=1.08129E-05, A2=-5.341895E-09, A3=9.526815E-11, A4=-9.8050089E-14, A5=-1.4768368E-15;

[0040] Wherein S9 is aspherical: c = 1 / R, R = 72.773, k = 0, A0 = 0, A1 = -6.4732264E-07, A2 = 1.9879985E-10, A3 = -2.3202729E-12, A4 = 9.3864011E-15, A5 = -1.4670778E-17;

[0041] Wherein S12 is aspherical: c = 1 / R, R = 108.44, k = 0, A0 = 0, A1 = -4.1674996E-06, A2 = 1.1234852E-08, A3 = 9.2807854E-12 A4 = 8.4229796E-13 A5 = -3.5212704E-15;

[0042] Wherein S13 is aspherical + binary: c = 1 / R, R = -47.935, k = 0, A0 = 0, A1 = -4.8570688E-06, A2 = 8.3618715E-08, A3 = 2.3756581E-10, A4 = 2.4648258E-12, A5 = -2.8395551E-14;

[0043] Binary diffraction order number M = 1, planning radius R = 8mm, step depth = 1.322316235um, quadratic coefficient = -38.086756, quartic coefficient = 0.94624123; 5 diffraction rings, respectively r 1= 3.256028, r 2= 4.614346, r 3= 5.663358, r 4= 6.553506, r 5= 7.34296.

[0044] In the embodiment, the lens further comprises a main lens barrel, an electric zoom mechanism and an electric focusing mechanism, the front fixed lens group, the zoom lens group and the focusing lens group are arranged inside the main lens barrel, the electric zoom mechanism drives the zoom lens group to move to realize continuous zooming of the lens focal length of 22.5-500mm, and the electric focusing mechanism drives the focusing lens group to move to realize focusing of the lens.

[0045] In the embodiment, as shown in Figure 2 The positive lens A is arranged inside the front end of the main lens barrel and is fixed by an A piece pressing ring, and an A piece adjusting gasket is arranged at the rear side of the positive lens A to realize adjustment of the air gap between the positive lens A and the negative lens B.

[0046] In the embodiment, as shown in Figure 2As shown, the main lens barrel is sequentially provided with a zooming slide I, a zooming slide II and a zooming slide III along the light path of light incidence, the zooming slide I, the zooming slide II and the zooming slide III are respectively provided with a B piece lens seat, a C piece lens seat and a D piece lens seat, the negative lens B is arranged on the B piece lens seat and fixed by a B piece pressing ring; the positive lens C is arranged on the C piece lens seat and fixed by a C piece pressing ring; the negative lens D is arranged on the D piece lens seat and fixed by a D piece pressing ring.

[0047] In the embodiment, as shown in the figure, Figure 3 The electric zooming mechanism includes a zooming switch frame, a first micro switch mounted on the zooming switch frame, a zooming motor frame arranged above the main lens barrel and a zooming motor mounted on the zooming motor frame, the output end of the zooming motor is provided with a zooming motor gear, the outside of the main lens barrel is provided with a zooming cam for engaging with the zooming motor gear, the zooming cam has three zooming cam grooves, three zooming cam guide nails are arranged in the three zooming cam grooves respectively, and the three zooming cam guide nails at the corresponding positions are connected with the zooming slide I, the zooming slide II and the zooming slide III respectively, the zooming cam is rotated to drive the zooming slide I, the zooming slide II and the zooming slide III to move simultaneously; the zooming cam is limited by a zooming cam pressing ring. Further, a high-precision steel column is used to transition between the zooming cam and the main lens barrel, so as to ensure the feeling and consistency during the operation.

[0048] In the embodiment, as shown in the figure, Figure 2 The rear end of the main lens barrel is provided with a focusing slide, the focusing slide is provided with a focusing lens seat, and the positive lens E is arranged on the focusing lens seat and fixed by an E piece pressing ring.

[0049] In the embodiment, as shown in the figure, Figure 3 The electric focusing mechanism includes a second micro switch, a focusing motor frame arranged on the main lens barrel and a focusing motor mounted on the focusing motor frame, the output end of the focusing motor is provided with a focusing motor gear, the outside of the main lens barrel is provided with a focusing cam for engaging with the focusing motor gear, the focusing cam has a focusing cam groove, a focusing cam guide nail is arranged in the focusing cam groove, and the focusing cam guide nail at the corresponding position is connected with the focusing slide.

[0050] In the embodiment, as shown in the figure, Figure 2 The embodiment further includes a turning seat arranged above the rear side of the main lens barrel, the turning seat is provided with a J piece lens seat 121 and a K piece lens seat 123, a mirror J is mounted on the J piece lens seat and fixed by a J piece pressing ring, a mirror K is arranged on the K piece lens seat and fixed by a K piece pressing ring, and the direction of light is turned by 180° through the two mirrors.

[0051] In the embodiment, the rear fixed mirror group is installed on the turning seat, and a positive lens F and a negative lens G are sequentially installed in the light propagation direction, wherein the FG spacer ring limits the air gap between the positive lens F and the negative lens G, and the negative lens G is provided with a G piece pressing ring 126 to fix the whole rear fixed mirror group.

[0052] The application realizes continuous zoom imaging from short focus 22.5 mm to long focus 500 mm, and realizes 90° turning of light propagation direction under the action of a mirror, so that the turned light converges on an imaging target surface of a refrigerator core to realize image collection of mid-wave infrared. After turning, the length of the lens group is shortened, and the secondary imaging design reduces the aperture of the lens scheme, the whole imaging system is compact, can be matched with a mid-wave infrared refrigerator 640*512, 15 mu detector, and is suitable for live recording and monitoring tasks, and is widely applied to forest fire prevention, border defense and other fields.

[0053] If the application discloses or involves mutually fixed connecting parts or structural parts, except for another statement, the fixed connection can be understood as: detachable fixed connection (for example, using bolt or screw connection), and can also be understood as: non-detachable fixed connection (for example, riveting, welding), of course, the mutually fixed connection can also be replaced by an integral structure (for example, integrally formed by using casting process) (obviously, except for the integral forming process).

[0054] In addition, the terms used to represent the position relationship or shape in any of the technical solutions disclosed in the application include the approximate, similar or close state or shape, except for another statement.

[0055] Any component provided by the application can be assembled from multiple individual components, or can be a single component manufactured by integral forming process.

[0056] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the application and not to limit them; although the application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that: the specific embodiments of the application can be modified or some technical features can be replaced by equivalent; without departing from the spirit of the technical solutions of the application, they should be covered in the technical solution range of the application claimed by the application.

Claims

1. A three-group zoom-magnification mid-wave cooled telephoto lens, characterized in that: The optical system of the lens consists of a front fixed lens group, a zoom lens group, a focusing lens group, a reflecting lens group, and a rear fixed lens group arranged sequentially along the incident light path. The front fixed lens group is a positive lens A; the zoom lens group consists of a negative lens B, a positive lens C, and a negative lens D arranged sequentially along the incident light path; the focusing lens group is a positive lens E; the reflecting lens group consists of a reflecting mirror J and a reflecting mirror K arranged sequentially along the incident light path, with reflecting mirrors J and K reversing the direction of the light by 180° through two reflections; the rear fixed lens group consists of a positive lens F and a negative lens G arranged sequentially along the incident light path. The lens also includes a main lens barrel, an electric zoom mechanism, and an electric focusing mechanism. The front fixed lens group, the zoom lens group, and the focusing lens group are all located inside the main lens barrel. The electric zoom mechanism drives the zoom lens group to move to achieve continuous zoom of the lens focal length from 22.5 to 500 mm. The electric focusing mechanism drives the focusing lens group to move to achieve lens focusing. Inside the main lens barrel, along the incident light path, there are three zoom slides: I, II, and III. Each of the zoom slides has a B-type lens mount, a C-type lens mount, and a D-type lens mount, respectively. The negative lens B is mounted on the B-type lens mount and fixed by a B-type retaining ring; the positive lens C is mounted on the C-type lens mount and fixed by a C-type retaining ring; and the negative lens D is mounted on the D-type lens mount and fixed by a D-type retaining ring.

2. The three-group variable magnification mid-wave cooled folding lens according to claim 1, characterized in that: The air gap between the positive lens A and the negative lens B is 45mm-95mm; the air gap between the negative lens B and the positive lens C is 3mm-101.4mm; the air gap between the positive lens C and the negative lens D is 12.96mm-51.34mm; the air gap between the negative lens D and the positive lens E is 23.8mm-45.44mm; the air gap between the positive lens E and the positive lens F is 108mm; and the air gap between the positive lens F and the negative lens G is 3mm.

3. The three-group variable magnification mid-wave cooled folding lens according to claim 1, characterized in that: The focal length of the optical system is f. The focal lengths of positive lens A, negative lens B, positive lens C, negative lens D, positive lens E, positive lens F, and negative lens G are f1, f2, f3, f4, f5, f6, and f7, respectively. The ratios of f1, f2, f3, f4, f5, f6, and f7 to f satisfy the following ratio: 0 <f1 / f<7,-1<f2 / f<0,0<f3 / f<2,-1<f4 / f<0,0<f5 / f<4,0<f6 / f<1,-2<f7 / f<0。 4. A three-group variable magnification mid-wave cooled folding lens according to claim 1, characterized in that: The positive lens A is located inside the front end of the main lens barrel and is fixed by the A-plate pressure ring. An A-plate adjustment shim is provided on the rear side of the positive lens A to adjust the air gap between the positive lens A and the negative lens B.

5. A three-group variable magnification medium-wave cooled folding lens according to claim 1, characterized in that: The electric zoom mechanism includes a first micro switch, a zoom motor mount located above the main lens barrel, and a zoom motor mounted on the zoom motor mount. The output end of the zoom motor is provided with a zoom motor gear. The outside of the main lens barrel is provided with a zoom cam for meshing with the zoom motor gear. The zoom cam has three zoom cam grooves, and each of the three zoom cam grooves is provided with a zoom cam guide pin. The three zoom cam guide pins at corresponding positions are respectively connected to zoom slide I, zoom slide II, and zoom slide III. When the zoom cam rotates, it drives zoom slide I, zoom slide II, and zoom slide III to move simultaneously. The zoom cam is limited by a zoom cam retaining ring.

6. A three-group variable magnification medium-wave cooled folding lens according to claim 1, characterized in that: A focusing slide is provided at the rear end of the main lens barrel, and a focusing lens mount is provided on the focusing slide. The positive lens E is mounted on the focusing lens mount and is fixed by an E-plate retaining ring.

7. A three-group variable magnification mid-wave cooled folding lens according to claim 6, characterized in that: The electric focusing mechanism includes a second micro switch, a focusing motor mount mounted on the main lens barrel, and a focusing motor mounted on the focusing motor mount. The output end of the focusing motor is provided with a focusing motor gear. The outside of the main lens barrel is provided with a focusing cam for meshing with the focusing motor gear. The focusing cam has a focusing cam groove, and a focusing cam guide pin is provided in the focusing cam groove. The focusing cam guide pin at the corresponding position is connected to the focusing slide.

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