Lightweight multi-focal-length lens

Abstract

The utility model relates to a light-weight multi-focal-length lens which is composed of a front fixing assembly, a zooming assembly, a focusing assembly, a reflector assembly, a rear fixing assembly and a detector assembly which are sequentially arranged in the incident direction of light, and the light passes through the front fixing assembly, the zooming assembly and the focusing assembly in sequence from front to back and then is focused on the reflector assembly. And the light is reflected by the reflector assembly and then passes through the rear fixing assembly from back to front. According to the lens, when the incident light aperture is large and the lens has dozens of times of focal length zoom switching use, the spatial size of the whole lens is shortened, the whole size is reduced, and the weight of the whole structure is reduced through a two-time refraction mode. Focal length switching of long focus and short focus is carried out in a four-claw crossing mode, and the overall size envelope of the lens is reduced. Conductive processing is carried out on the detector part, and the electromagnetic compatibility of the lens is enhanced.

Description

TECHNICAL FIELD

[0001] The utility model relates to a light weight multi -times focal length lens belongs to photoelectric technology field. BACKGROUND

[0002] For large aperture, moreover, long focal length zoom lens, because focal length is too long, focusing range is big, will make lens light entrance aperture become big, lead to first piece of lens aperture size is too big, thereby cause the whole structure volume increases, drive the increase of whole weight, make load weight is too big, and cannot reach some specific environment use requirement. UTILITY MODEL CONTENTS

[0003] In view of prior art's insufficient, the utility model solves the technical problem that provides a light weight multi -times focal length lens.

[0004] In order to solve above-mentioned technical problem, the utility model's technical scheme is: a light weight multi -times focal length lens, the lens is by the front fixed subassembly, zoom subassembly, focusing subassembly, reflector subassembly, rear fixed subassembly, detector subassembly that setting gradually along the light ray incidence direction constitute, the light ray is from front to back through front fixed subassembly, zoom subassembly, focusing subassembly again, after the reflection of reflector subassembly, from rear to front through rear fixed subassembly;The front fixed subassembly is by positive crescent lens A, positive crescent lens B gradually along the light ray incidence direction constitute, the zoom subassembly is by double concave lens C, double convex lens D gradually along the light ray incidence direction constitute, the focusing subassembly is by negative crescent lens E constitute, the rear fixed subassembly is by positive crescent lens F, double concave lens G, double convex lens H gradually along the light ray incidence direction constitute.

[0005] Preferably, the air interval between the positive crescent lens A and the positive crescent lens B is 22.67mm, the air interval between the positive crescent lens B and the double concave lens C is 21.68mm, the air interval between the double concave lens C and the double convex lens D is 143.97mm, the air interval between the double convex lens D and the negative crescent lens E is 7.11mm, the air interval between the negative crescent lens E and the positive crescent lens F is 174.71mm, the air interval between the positive crescent lens F and the double concave lens G is 9.58mm, and the air interval between the double concave lens G and the double convex lens H is 0.16mm.

[0006] Preferably, the reflector subassembly is composed of a reflector A and a reflector B, and the included angle between the reflector A and the reflector B is 90°.

[0007] Compared with the prior art, the lens has the following beneficial effects: the lens has a large incident light aperture and a ten-fold focal length zoom switching function, the overall volume is compressed, the overall length is shortened, the weight of the overall structure is reduced, the precise fit between the structural members is achieved, the system total length is short, the structure is compact, and a lightweight multiple focal length lens is completed.

[0008] The utility model will be further explained in detail below in combination with the drawings and specific embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0009] Figure 1 It is a lens structure schematic view of the utility model embodiment.

[0010] Figure 2 It is a lens optical lens schematic view of the utility model embodiment.

[0011] Figure 3-1 It is a lens focusing assembly schematic of the utility model embodiment Figure 1 .

[0012] Figure 3-2 It is a lens focusing assembly schematic of the utility model embodiment Figure 2 .

[0013] Figure 4-1 It is a lens zoom assembly schematic of the utility model embodiment Figure 1 .

[0014] Figure 4-2 It is a lens zoom assembly schematic of the utility model embodiment Figure 2 .

[0015] Figure 5 It is a lens mirror assembly structure schematic view of the utility model embodiment.

[0016] Figure 6 It is a lens focusing assembly and mirror assembly installation schematic view of the utility model embodiment.

[0017] Figure 7 It is a zooming carriage and compensation carriage assembly schematic view of the utility model embodiment.

[0018] Figure 8 It is a lens focusing guide pin assembly structure schematic view of the utility model embodiment.

[0019] Figure 9-1 It is a lens optical system large field focal length 25mm dispersion diagram of the utility model embodiment.

[0020] Figure 9-2 It is a lens optical system small field focal length 700mm dispersion diagram of the utility model embodiment.

[0021] Figure 10-1 For the embodiment of the utility model lens optical system large field focal length 25mm transfer function diagram.

[0022] Figure 10-2 For the embodiment of the utility model lens optical system small field focal length 700mm transfer function diagram.

[0023] Figure 11 For the embodiment of the utility model lens optical system continuous zoom part short focus time's cold reflection characteristic quantity schematic view.

[0024] Figure 12 For the embodiment of the utility model lens optical system 25 times continuous zoom thermal imaging observation sight lens's cold reflection characteristic quantity schematic view.

[0025] In the drawing:

[0026] A- positive crescent lens A, B- positive crescent lens B, C- double concave lens C, D- double convex lens D, E- negative crescent lens E, F- positive crescent lens F, G- double concave lens G, H- double convex lens H;

[0027] 1- front fixed assembly, 2- zoom assembly, 3- focusing assembly, 4- mirror assembly, 5- rear fixed assembly, 6- detector assembly, 7- mirror A, 8- mirror B, 11- focusing lens group, 12- focusing main lens barrel, 13- guide pin, 14- focusing guide pin assembly, 15- focusing cam, 16- focusing potentiometer, 17- focusing potentiometer gear, 18- focusing motor, 19- focusing motor gear, 21- zoom lens group, 22- zoom carriage, 23- front precision steel ball, 24- zoom guide pin assembly, 25- zoom cam, 26- roller, 27- rear precision steel ball, 28- zoom cam pressing ring, 29- compensation lens group, 210 compensation carriage, 211- compensation guide pin assembly, 212- transition ring, 213- zoom limit pin, 214- zoom motor, 215- zoom motor gear, 216- zoom potentiometer, 217- zoom potentiometer gear. DETAILED DESCRIPTION

[0028] The utility model will be further explained below in combination with the drawings and examples.

[0029] It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the present application. Unless otherwise indicated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

[0030] It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments in accordance with the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and / or "comprising," when used in this specification, specify the presence of stated features, steps, operations, elements, components, and / or groups thereof, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and / or groups thereof.

[0031] As shown in the figure, the embodiment provides a light multi-telephoto lens, which is composed of a front fixed component 1, a zoom component 2, a focusing component 3, a mirror component 4, a rear fixed component 5 and a detector component 6 arranged in sequence along the light incident direction, has the functions of electric focusing, electric continuous zooming and image output, and achieves the results of short system total length and compact structure through precise matching between structural components, thereby completing the design of the light multi-telephoto lens. Figures 1~12 When the detector component is installed, the detector is fully enveloped, and the metal parts are subjected to conductive oxidation treatment, so that electromagnetic compatibility treatment is performed in this way to exclude the influence of external factors on the imaging quality of the camera.

[0032] The light passes through the front fixed component, the zoom component and the focusing component in sequence from front to back, and then passes through the rear fixed component from back to front after being reflected by the mirror component. The mirror component makes the light image in the opposite direction through twice fold reflection, so that the structure design of short system total length and compact structure is achieved.

[0033] The front fixed component is composed of a positive crescent lens A and a positive crescent lens B in sequence along the light incident direction, the zoom component is composed of a double-concave lens C and a double-convex lens D in sequence along the light incident direction, the focusing component is composed of a negative crescent lens E, and the rear fixed component is composed of a positive crescent lens F, a double-concave lens G and a double-convex lens H in sequence along the light incident direction.

[0034] In the embodiment of the utility model, the air interval between positive crescent lens A and positive crescent lens B is 22.67mm, the air interval between positive crescent lens B and double-concave lens C is 21.68mm, the air interval between double-concave lens C and double-convex lens D is 143.97mm, the air interval between double-convex lens D and negative crescent lens E is 7.11mm, the air interval between negative crescent lens E and positive crescent lens F is 174.71mm, the air interval between positive crescent lens F and double-concave lens G is 9.58mm, and the air interval between double-concave lens G and double-convex lens H is 0.16mm.

[0035]

[0036] ​The air gap is a theoretical gap in design, and in actual assembly, various external factors can affect the air gap, such as machining errors of structural parts, refractive indexes of lens materials, and relative position deviation during assembly, which can cause slight changes in the air gap between the lenses during optimal imaging, so different thicknesses of mechanical parts are used between some lenses which are greatly affected by the air gap.

[0037] In optical design, the air gap between the E plate and the F plate is lengthened, the space size of the whole lens is shortened through twice refraction.

[0038] In the embodiment of the utility model, the mirror assembly is composed of mirror A and mirror B, and the included angle between the mirror A and the mirror B is 90°.

[0039] The focusing assembly is fixed at the incident light position of the mirror A in the mirror assembly, and the focusing effect of the final imaging is changed by adjusting the serial number 15 focusing cam on the focusing assembly.

[0040] In the embodiment of the utility model, the focusing assembly is composed of the optical system negative crescent lens E. Figure 3-1 3-2 The serial number 14 focusing guide pin assembly is composed of a guide pin, two rotatable rollers and a transition ring. Figure 8 The two rollers are coaxially sleeved on the outer circumferential part of the guide pin, and the transition ring is arranged between the two rollers. The guide pin is used for connecting the focusing assembly and the whole lens, the two rollers are respectively abutted with the serial number 15 focusing cam and the serial number 12 focusing main lens barrel, and the gap is as small as possible, so that the whole operation is more smooth.

[0041] The serial number 11 focusing lens group and the serial number 15 focusing cam are respectively abutted with the serial number 12 focusing main lens barrel and then are arranged in the serial number 12 focusing main lens barrel, the serial number 15 focusing cam is milled with an inclined groove according to the requirement of the optical system on the focusing amount, and the serial number 12 focusing main lens barrel is milled with a straight groove; the serial number 14 focusing guide pin assembly is used for connecting the serial number 11 focusing lens group, the serial number 15 focusing cam and the serial number 12 focusing main lens barrel, the serial number 19 focusing motor gear is engaged with the gear on the serial number 15 focusing cam. When the serial number 18 focusing motor is powered and rotated to drive the serial number 15 focusing cam to rotate, the rotary motion of the serial number 11 focusing lens group is converted into linear motion through the straight groove on the serial number 12 focusing main lens barrel, so that the focusing on the near and far targets is realized, and the focusing process is completed. When the focusing on the near and far targets is performed, the serial number 17 focusing potentiometer gear is engaged with the serial number 19 focusing motor gear to drive the serial number 16 focusing potentiometer shaft to rotate, so that the resistance value of the potentiometer changes, the change value of the potentiometer can be read through a proper sampling circuit and is transmitted to the control center, so that the display of the focusing distance value is realized; conversely, the real-time control of the focusing distance value can be realized through the command given by the control center.​

[0042] Reference Figure 4-1 , 4-2 , the zoom assembly is composed of the zoom lens group 21 mounted on the zoom slide 22 by screws, and the compensation lens group 29 mounted on the compensation slide 210 by screws. The zoom slide 22 and the compensation slide 210 are respectively mounted in the main lens barrel 26 after being ground-fitted with the main lens barrel 26. The zoom cam 25 is mounted on the main lens barrel 26 by the front and rear precision steel balls 23 and 27, and is pressed by the zoom cam pressing ring 28 to form a rolling bearing structure. Then, the zoom cam 25 is connected with the zoom slide 22 and the compensation slide 210 by the zoom guide pin assembly 24 and the compensation guide pin assembly 211. The zoom motor gear 215 and the zoom potentiometer gear 217 are respectively engaged with the zoom cam gear. The zoom assembly and the compensation assembly are moved forward and backward linearly according to the zoom motion equation by rotating the zoom motor 214, so as to realize the continuous variable function of the focal length of the system. When the focal length of the system changes, the zoom potentiometer gear 217 is engaged with the zoom cam gear, so that the zoom potentiometer 216 rotates, the resistance of the zoom potentiometer 216 changes, the change value of the zoom potentiometer 216 is taken out by a proper sampling circuit and is transmitted to the control center, so as to realize the display of the focal length value. Conversely, the focal length can be controlled in real time by giving a command from the control center.

[0043] The weight of the zoom cam 25 is reduced by digging holes on the outer surface under the premise of ensuring the rigidity and strength.

[0044] Reference Figure 7 The zoom slide 22 and the compensation slide 210 are designed as four-claw structures. When switching from the short-focus state to the long-focus state, the claws of the zoom slide 22 and the compensation slide 210 are crossed and folded, so as to effectively reduce the occupied space, increase the optical axis stability of the lens, and reduce the overall size of the lens.

[0045] Reference Figure 5 The light is reflected twice by the mirror A and the mirror B, so that the light is imaged in the opposite direction. The mirror A and the mirror B are fixed at an angle of 45° in the opposite direction, so as to ensure that the angle between the reflected light and the incident light is 90°, and the imaging direction is consistent with the direction of the incident light through the mirror A after being reflected twice. Due to the machining error of the parts and the manual adjustment error of the assembly, the installation angle of the mirror cannot be accurately ensured during the assembly and adjustment. Therefore, separate fixed supports are designed for the mirror A and the mirror B, the angle of the mirror is adjusted by calibrating the imaging target, so as to meet the requirements.

[0046] Reference Figure 6 The focusing assembly is fixed at the incident light position of the mirror A of the mirror assembly, and the focusing effect of the final imaging is changed by adjusting the focusing cam of serial number 15 on the focusing assembly. Figure 3-1 、 3-2 Since the connecting flange mounting hole of the serial number 12 focusing main lens barrel and the mirror assembly is located at the bottom of the serial number 15 focusing cam, the serial number 15 focusing cam needs to be treated by giving way. By calculating the switching angle of the serial number 15 focusing cam along the axis, the excess parts are cut out to ensure that the exposed space is greater than one-half, so that the four mounting holes can be normally fixed.

[0047] Reference Figure 9-1 、 9-2 The RMS spot radius of each field of view is less than 8.3 μm, which is less than the Airy spot radius, indicating that the system has good imaging quality.

[0048] The cold reflection effect is that the cooling surface of the infrared detector is reflected by a certain optical surface in the front part of the system, and the reflected image is just near the detector. At this time, the detector will sense the cold radiation signal of itself which is very different from the ambient temperature, and a black spot will often be formed in the center of the field of view. This imaging defect caused by one reflection of the cooling surface is also called the temperature difference regeneration effect. For a cooling type infrared optical system, the cold reflection effect will directly affect the image quality of the infrared system, and in severe cases, it will even annihilate the target signal. Therefore, it is necessary to consider reducing or eliminating the cold reflection effect at the stage of optical design. YNI and I / Ibar are usually used to characterize the cold reflection (Narcissus) of the system. YNI mainly reflects the intensity of the cold image in the central field of view, and it is also a reflection of the cold reflection level. When the YNI value of a certain surface is 0, the cold reflection of this surface is the strongest. Therefore, during the design, the YNI value of each refractive surface should be as high as possible to make the reflected cold light off focus. I / Ibar mainly reflects the change of the cold reflection with the field of view. For I / Ibar, the value can be increased by changing the curvature. If the value is greater than 1, it means that the cold reflection noise hardly changes with the field of view. In optical design, the YNI and I / Ibar of each surface are controlled to be greater than 1 as much as possible to reduce the influence of the cold image on the imaging quality of the system, and to make the mirror cold reflection "black spot" away from the detector image plane.

[0049] The cold reflection spot is most likely to occur at the short focal length of the continuous zoom part, so the cold reflection characteristics at the short focal length of the continuous zoom part will be analyzed. Reference Figure 11 The YNI value, I / Ibar value and cold reflection relative intensity ratio (Intensity) of each surface can be seen that the cold reflection intensity of surfaces 1, 4 and 5 is larger. Figure 12 From Figure 12 and Figure 11It can be seen that the relative intensity difference of cold reflection of 1, 4 and 5 is small, but the YNI value is different. The YNI value of 1, 4 and 5 of the short focal length of the continuous zoom part is basically the same as the YNI value of the 25 times thermal image sighting lens, which can ensure that there is no obvious cold spot caused by cold reflection in the process of observing uniform scene.

[0050] The image quality of the infrared system is observed through the cold reflection effect, and the cold reflection characteristics in the short focal length of the continuous zoom part are analyzed, so that the obvious cold spot caused by cold reflection in the process of observing uniform scene can be avoided, and the imaging quality of the lens is ensured.

[0051] The design can meet the indexes:

[0052] 1) working wavelength: 3.7 μm~4.8 μm;

[0053] 2) focal length f: 25 mm~700 mm;

[0054] 3) F / #: 4;

[0055] 4) field of view: 21.7°x17.4°~0.79°x0.63°;

[0056] 5) weight: ≤5.6 kg.

[0057] The above is only a preferred embodiment of the present application, and is not intended to limit the present application in other forms. Any skilled person in the art can modify or change the above disclosed technical content to obtain equivalent embodiments. However, any simple modification, equivalent change and modification of the above embodiments without departing from the technical scheme of the present application, according to the technical essence of the present application, still belongs to the protection scope of the technical scheme of the present application.

Claims

1. A lightweight multi-focal length lens characterized by: The lens is composed of a front fixed component, a zoom component, a focusing component, a mirror component, a rear fixed component and a detector component arranged in sequence along the light incident direction, the light passes through the front fixed component, the zoom component and the focusing component in sequence from front to back, and then passes through the rear fixed component from back to front after being reflected by the mirror component; the front fixed component is composed of a positive crescent lens A and a positive crescent lens B in sequence along the light incident direction, the zoom component is composed of a double-concave lens C and a double-convex lens D in sequence along the light incident direction, the focusing component is composed of a negative crescent lens E, and the rear fixed component is composed of a positive crescent lens F, a double-concave lens G and a double-convex lens H in sequence along the light incident direction.

2. The lightweight multi-focus lens according to claim 1, wherein: The air gap between the positive crescent lens A and the positive crescent lens B is 22.67 mm, the air gap between the positive crescent lens B and the double-concave lens C is 21.68 mm, the air gap between the double-concave lens C and the double-convex lens D is 143.97 mm, the air gap between the double-convex lens D and the negative crescent lens E is 7.11 mm, the air gap between the negative crescent lens E and the positive crescent lens F is 174.71 mm, the air gap between the positive crescent lens F and the double-concave lens G is 9.58 mm, and the air gap between the double-concave lens G and the double-convex lens H is 0.16 mm.

3. The lightweight multi-focus lens of claim 1, wherein: The mirror component is composed of a mirror A and a mirror B, and the included angle between the mirror A and the mirror B is 90°.

Images