CN111367063B - Medium-wave infrared continuous zoom lens and imaging device - Google Patents
Medium-wave infrared continuous zoom lens and imaging device Download PDFInfo
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- CN111367063B CN111367063B CN201811591876.2A CN201811591876A CN111367063B CN 111367063 B CN111367063 B CN 111367063B CN 201811591876 A CN201811591876 A CN 201811591876A CN 111367063 B CN111367063 B CN 111367063B
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- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B15/00—Optical objectives with means for varying the magnification
- G02B15/14—Optical objectives with means for varying the magnification by axial movement of one or more lenses or groups of lenses relative to the image plane for continuously varying the equivalent focal length of the objective
- G02B15/16—Optical objectives with means for varying the magnification by axial movement of one or more lenses or groups of lenses relative to the image plane for continuously varying the equivalent focal length of the objective with interdependent non-linearly related movements between one lens or lens group, and another lens or lens group
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- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B13/00—Optical objectives specially designed for the purposes specified below
- G02B13/001—Miniaturised objectives for electronic devices, e.g. portable telephones, webcams, PDAs, small digital cameras
- G02B13/0015—Miniaturised objectives for electronic devices, e.g. portable telephones, webcams, PDAs, small digital cameras characterised by the lens design
- G02B13/002—Miniaturised objectives for electronic devices, e.g. portable telephones, webcams, PDAs, small digital cameras characterised by the lens design having at least one aspherical surface
- G02B13/0045—Miniaturised objectives for electronic devices, e.g. portable telephones, webcams, PDAs, small digital cameras characterised by the lens design having at least one aspherical surface having five or more lenses
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- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B13/00—Optical objectives specially designed for the purposes specified below
- G02B13/001—Miniaturised objectives for electronic devices, e.g. portable telephones, webcams, PDAs, small digital cameras
- G02B13/008—Miniaturised objectives for electronic devices, e.g. portable telephones, webcams, PDAs, small digital cameras designed for infrared light
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- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B13/00—Optical objectives specially designed for the purposes specified below
- G02B13/001—Miniaturised objectives for electronic devices, e.g. portable telephones, webcams, PDAs, small digital cameras
- G02B13/009—Miniaturised objectives for electronic devices, e.g. portable telephones, webcams, PDAs, small digital cameras having zoom function
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- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B15/00—Optical objectives with means for varying the magnification
- G02B15/14—Optical objectives with means for varying the magnification by axial movement of one or more lenses or groups of lenses relative to the image plane for continuously varying the equivalent focal length of the objective
- G02B15/16—Optical objectives with means for varying the magnification by axial movement of one or more lenses or groups of lenses relative to the image plane for continuously varying the equivalent focal length of the objective with interdependent non-linearly related movements between one lens or lens group, and another lens or lens group
- G02B15/163—Optical objectives with means for varying the magnification by axial movement of one or more lenses or groups of lenses relative to the image plane for continuously varying the equivalent focal length of the objective with interdependent non-linearly related movements between one lens or lens group, and another lens or lens group having a first movable lens or lens group and a second movable lens or lens group, both in front of a fixed lens or lens group
- G02B15/167—Optical objectives with means for varying the magnification by axial movement of one or more lenses or groups of lenses relative to the image plane for continuously varying the equivalent focal length of the objective with interdependent non-linearly related movements between one lens or lens group, and another lens or lens group having a first movable lens or lens group and a second movable lens or lens group, both in front of a fixed lens or lens group having an additional fixed front lens or group of lenses
- G02B15/173—Optical objectives with means for varying the magnification by axial movement of one or more lenses or groups of lenses relative to the image plane for continuously varying the equivalent focal length of the objective with interdependent non-linearly related movements between one lens or lens group, and another lens or lens group having a first movable lens or lens group and a second movable lens or lens group, both in front of a fixed lens or lens group having an additional fixed front lens or group of lenses arranged +-+
Abstract
The invention discloses a medium-wave infrared continuous zoom lens, wherein a front fixed group, a zoom lens group, a compensation lens group, a rear fixed group and a secondary imaging lens group are coaxially and sequentially arranged from an object side to an image side, the front fixed group has positive focal power, the zoom lens group has negative focal power, the compensation lens group has positive focal power, the rear fixed group has positive focal power, the secondary imaging lens group has positive focal power, and the zoom lens group and/or the compensation lens group can axially move to realize continuous zooming. The medium-wave infrared continuous zoom lens has a compact structure and meets the cold diaphragm efficiency of 100%; the axial movement of the zoom lens group and/or the compensation lens group realizes the continuous zooming of the system, the zooming stroke is short, the curve is smooth, and the imaging quality is good in the full-focus range.
Description
Technical Field
The invention relates to the technical field of optical imaging, in particular to a medium-wave infrared continuous zoom lens and an imaging device.
Background
When the optical instrument is used in a large temperature range, the lens focal power can be changed due to the expansion with heat and contraction with cold of the lens barrel material and the optical material and the temperature refractive index coefficient of the optical material, so that the defocusing phenomenon is generated, and the optical system can be defocused due to the expansion with heat and contraction with cold of the lens barrel material, so that the imaging quality is reduced. In order to reduce the influence of temperature variation on the imaging quality of the infrared optical system, a athermal design, or a thermal difference elimination design, is required, that is, through certain mechanical, optical, electronic and other technologies, defocusing caused by temperature variation is compensated, so that the infrared optical system keeps stable imaging quality in a temperature interval with a large variation range. The current heat difference eliminating mode mainly comprises the following steps: electromechanical active athermal differential, mechanical passive athermal differential, and optical passive athermal differential.
When the focal length of the infrared continuous zooming optical system is continuously changed in a certain range, the image surface is stable and good image quality can be kept. The size of the image surface scenery is continuously variable, and the visual effect which cannot be achieved by a fixed-focus lens and a multi-gear zoom lens can be achieved, so that the purposes of searching for a target with a large view field and carefully observing the target with a small view field are achieved.
At present, domestic research on a medium-wave infrared continuous zooming optical system has been reported in documents. According to the 'compact medium wave infrared continuous zooming optical system design' of Chenluji, 27.5 mm-458 mm continuous zooming is realized for a refrigeration type 320 x 240-element staring focal plane detector (infrared technology 2010, 32 (10)). For the design of the focal plane array detector with 640 × 512 staring elements, the following documents are disclosed: the invention discloses a middle wave infrared continuous zoom lens which can be applied to a 640 multiplied by 512-element 25 mu m refrigeration type middle wave detector, has a focal length range of 50 mm-500 mm, a zoom ratio of 10 times and a maximum moving lens group stroke of 123mm, but has the defects that: because the maximum travel of the mobile group is too long, the view field switching time is increased, and the difficulty of ensuring the superposition accuracy of wide and narrow view fields is increased. Chinese patent publication No. CN106526818 discloses a three-group linked compact high zoom ratio infrared connection zoom optical system. However, the system adopts a three-component zooming mode, so that the optical system has a complex structure and higher control precision requirement.
In summary, the axial size of a typical medium-wave infrared zoom lens is too long, a light path needs to be folded by a screen reflector, the space size is large, and the actual use requirements of high zoom ratio and small size are difficult to meet. In addition, the optical material used by the infrared lens is greatly affected by temperature, and optical parameters such as refractive index, thickness, curvature radius and the like of the optical material can change along with the temperature, so that the focal plane drifts, and the imaging quality is reduced. The temperature caused degradation of image quality is particularly noticeable when the lens is moved to the telephoto end. The problems greatly limit the applicability and application range of the existing infrared zoom lens.
Disclosure of Invention
The embodiment of the invention provides a medium-wave infrared continuous zoom lens and an imaging device, which can realize compact lens structure and have medium-wave infrared continuous zooming capability.
A first aspect provides a medium wave infrared continuous zoom lens, wherein a front fixed group, a zoom lens group, a compensation lens group, a rear fixed group and a secondary imaging lens group are coaxially and sequentially arranged from an object side to an image side, the front fixed group has positive focal power, the zoom lens group has negative focal power, the compensation lens group has positive focal power, the rear fixed group has positive focal power, the secondary imaging lens group has positive focal power, and the zoom lens group and/or the compensation lens group can axially move to realize continuous zooming.
With reference to the implementation manner of the first aspect, the secondary imaging lens group includes a first meniscus lens with positive power protruding to the image side and a second meniscus lens with positive power protruding to the image side and located on the image side of the first meniscus lens; the first meniscus lens and the second meniscus lens are both germanium lenses.
With reference to the implementation manner of the first aspect, the image side surface of the anterior fixation group is an even aspheric surface; the image side surface of the zoom lens group is an even aspheric surface; the object side surface of the compensation lens group is an even-order aspheric surface; the object side surface of the rear fixed group is a diffraction surface processed on an even-order aspheric surface substrate; the object side surface of the first meniscus lens is a diffraction surface processed on an even-order aspheric substrate, and the object side surface of the second meniscus lens is an even-order aspheric surface.
With reference to the implementation manner of the first aspect, the equation of the even aspheric surface is:
in the formula, Z is a distance rise from a vertex of the aspherical surface when the aspherical surface is at a position having a height h in the optical axis direction. c is 1/r, r represents the radius of curvature of the mirror surface, k is conic coefficient, A, B, C, D is high-order aspheric coefficient
Alternatively, the equation for the diffractive surface is:
φ(h)＝α1h2+α2h4+…
wherein alpha is1、α2Is the diffraction coefficient.
With reference to the implementation manner of the first aspect, the higher-order aspheric coefficients of the equation of the even-order aspheric surfaces of the pre-fixed set are: a is 1.69e-07, B is 2.52e-13, C is-2.09 e-16, D is 2.57 e-20; the high-order aspheric surface coefficient of the equation of the even-order aspheric surface of the zoom lens group is as follows: a is-1.35 e-06, B is-5.82 e-11, C is 5.01e-13, D is-4.26 e-16; the high-order aspheric surface coefficient of the equation of the even-order aspheric surface of the compensation lens group is as follows: a is-5.29 e-07, B is-1.14 e-10, C is 2.52e-13, D is-1.50 e-16; the higher-order aspheric coefficients of the equation for the even-order aspheric surfaces of the post-fixation group are: a is-6.05 e-07, B is-2.85 e-09, C is 1.09e-11, D is-4.31 e-14; the high-order aspheric surface coefficient of the even-order aspheric surface equation of the first meniscus lens is as follows: a is-2.94 e-04, B is 9.81e-06, C is-1.38 e-06, D is 3.51 e-08; the high-order aspheric surface coefficient of the even-order aspheric surface equation of the second meniscus lens is as follows: a is-6.52 e-05, B is 3.63e-07, C is 2.17e-09, and D is-5.83 e-11. Alternatively, the diffraction coefficients of the equations for the diffraction surface of the post-fixation set are: alpha is alpha1Is-1.72 e-04, alpha2Is-1.11 e-07; the diffraction coefficient of the equation for the diffractive surface of the first meniscus lens is: alpha is alpha1Is-1.35 e-03, alpha2Is 5.29 e-06.
With reference to the implementation manner of the first aspect, the F number is constant to 4.0, the applicable waveband is 3.4 μm to 5.0 μm, and the focal length range of the continuous zooming is 29.4mm to 470 mm.
With reference to the implementation manner of the first aspect, an intermediate image is formed 21.29mm behind the rear fixed group, and the secondary imaging lens group is disposed 3.13mm behind the intermediate image.
With reference to the implementation manner of the first aspect, the front fixed group is a positive meniscus silicon lens with a convex surface facing the object; the zoom lens group is a biconcave germanium negative lens; the compensation lens group is a biconvex positive lens; the rear fixed group is a meniscus zinc sulfide or zinc selenide positive lens with a convex surface facing the object space.
The second aspect provides an imaging device, which comprises the medium wave infrared continuous zoom lens and a medium wave infrared detector for receiving the image formed by the medium wave infrared continuous zoom lens.
With reference to the implementation manner of the second aspect, the medium wave infrared detector is a refrigeration medium wave infrared detector with a resolution of 640 × 512 and a pixel size of 15 μm or 20 μm.
The invention has the beneficial effects that: the medium-wave infrared continuous zoom lens has a compact structure and meets the cold diaphragm efficiency of 100%; the axial movement of the zoom lens group and/or the compensation lens group realizes the continuous zooming of the system, the zooming stroke is short, the curve is smooth, and the imaging quality is good in the full-focus range.
Drawings
In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts. Wherein:
fig. 1 is a schematic view of a telephoto path of the medium-wave infrared continuous zoom lens according to the embodiment of the invention.
Fig. 2 is a schematic diagram of a middle focus optical path of the medium-wave infrared continuous zoom lens according to the embodiment of the present invention.
FIG. 3 is a schematic short-focus optical path diagram of the medium-wave infrared continuous zoom lens according to the embodiment of the present invention.
FIG. 4 is a graph of MTF at 20 ℃ in telephoto for the intermediate wave infrared continuous zoom lens according to the embodiment of the present invention.
FIG. 5 is a MTF curve diagram of the mid-focus of the mid-wave infrared continuous zoom lens according to the embodiment of the present invention at 20 ℃.
FIG. 6 is a MTF curve under 20 ℃ of short focus for the middle-wave infrared continuous zoom lens according to the embodiment of the present invention.
FIG. 7 is a MTF curve under a condition of tele-40 ℃ of the intermediate-wave infrared continuous zoom lens according to the embodiment of the present invention.
FIG. 8 is a MTF curve diagram of the mid-wave infrared continuous zoom lens according to the embodiment of the present invention at a telephoto temperature of 80 ℃.
FIG. 9 is a MTF curve diagram of the intermediate focus of the intermediate wave infrared continuous zoom lens according to the embodiment of the present invention at-40 ℃.
FIG. 10 is a MTF curve diagram of the mid-focus of the mid-wave infrared continuous zoom lens according to the embodiment of the present invention at 80 ℃.
FIG. 11 is a MTF curve under the condition of-40 ℃ short focus of the intermediate-wave infrared continuous zoom lens according to the embodiment of the present invention.
FIG. 12 is a MTF curve graph at 80 ℃ for short focus of the mid-wave infrared continuous zoom lens according to the embodiment of the present invention.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Fig. 1 is a schematic view of a telephoto path of the medium-wave infrared continuous zoom lens according to the embodiment of the invention. Fig. 2 is a schematic diagram of a middle focus optical path of the medium-wave infrared continuous zoom lens according to the embodiment of the present invention. FIG. 3 is a schematic short-focus optical path diagram of the medium-wave infrared continuous zoom lens according to the embodiment of the present invention. For convenience of explanation, only portions related to the present invention are shown in the drawings. Referring to fig. 1, 2 and 3, a medium wave infrared continuous zoom lens according to an embodiment of the present invention includes a front fixed group 110, a zoom lens group 120, a compensation lens group 130, a rear fixed group 140 and a secondary imaging lens group 150 coaxially and sequentially arranged from an object side to an image side, the front fixed group 110 has positive focal power, the zoom lens group 120 has negative focal power, the compensation lens group 130 has positive focal power, the rear fixed group 140 has positive focal power, the secondary imaging lens group 150 has positive focal power, and the zoom lens group 120 and/or the compensation lens group 130 can axially move to achieve continuous zooming. In the field of optical lens technology, it is a common technique how to implement moving zooming/focusing, for example, the zoom lens group 120 and/or the compensation lens group 130 can be mounted on a slidable or rolling rail or device, and the moving or moving can be implemented by a stepping motor or other power device, therefore, regarding this part, it will not be described in detail in this specification.
The medium wave infrared continuous zoom lens provided by the embodiment of the invention adopts five groups of lenses, has simple and reasonable structural design and very compact volume, meets the requirement of 100% of cold diaphragm efficiency, realizes the continuous zooming of a system by the axial movement of the zoom lens group and/or the compensation lens group, has short zooming stroke and smooth curve, has good imaging quality in a full focus range, and is beneficial to the batch production of lenses.
The lens group described in the present invention may be a single lens in this embodiment or other embodiments, or may be a lens group composed of several lenses. According to the direction of the light path, the left side surface of all optical elements in the diagram is defined as a front surface, and the right side surface of all optical elements in the diagram is defined as a rear surface; the left side is defined as the object side, and the right side is defined as the image side.
Specifically, this embodiment preferably:
the front fixed group 110 is a positive meniscus lens 110 with a convex surface facing the object, the front fixed group 110 is a fixed lens, that is, the position of the positive meniscus lens 110 in the lens is fixed, and the mid-wave infrared light is converged by the positive meniscus lens 110. The image side surface of the front fixed group 110 is even aspheric, that is, the rear surface 112 of the positive meniscus lens 110 is even aspheric, and the front surface 111 of the positive meniscus lens 110 is spherical. The material of the positive meniscus lens 110 is preferably a silicon material, and more preferably a silicon crystal material, which is convenient for processing and production and has stable optical quality.
The zoom lens group 120 is a double concave negative lens 120, and is used for changing the focal length and the variable magnification of the medium wave infrared continuous zoom lens. The front surface 121 of the biconcave negative lens 120 is spherical, and the back surface 122 (i.e., the image-side surface of the zoom lens group 120) is an even-aspheric surface. The moving stroke of the double concave negative lens 120 is 50.24mm, which satisfies the requirement of zooming in a larger range. The material of the double-concave negative lens 120 is a germanium material, and is further preferably a germanium crystal material, so that the processing and the production are convenient, and the optical quality is stable.
The compensation lens group 130 is a biconvex positive lens 130, and is used for compensating the shift of the image plane position of the medium-wave infrared continuous zoom lens in the zooming process. The front surface 131 (i.e., the object-side surface of the compensation lens group 130) of the biconvex positive lens 130 is an even aspheric surface, and the rear surface 132 is a spherical surface. The moving stroke of the biconvex positive lens 130 is 30.16mm, which satisfies the requirement of zooming in a larger range. The material of the biconvex positive lens 130 is preferably a silicon material, and is further preferably a silicon crystal material, so that the processing and the production are convenient, and the optical quality is stable.
The axial movement of the biconcave negative lens 120 and the biconvex positive lens 130 realizes the continuous zooming of the medium wave infrared continuous zoom lens, and the zooming stroke is short and the curve is smooth.
The rear fixed group 140 is a positive meniscus lens 140 with the convex surface facing the object, and the rear fixed group 140 is also a fixed lens group. The front surface 141 of the positive meniscus lens 140 (i.e., the object side surface of the rear fixed group 140) is a diffractive surface machined on an even-order aspheric substrate, and the rear surface 142 is spherical. The anterior surface 141 has a base even-order aspheric surface and a diffractive surface machined on the base, and therefore, the surface is constrained by both the even-order aspheric equation and the diffractive equation. The material of the positive meniscus lens 140 is preferably zinc sulfide or zinc selenide, and is further preferably zinc sulfide crystal material or zinc selenide crystal material, so that the processing and production are convenient, and the optical quality is stable.
After being focused by the front four groups of optical elements, such as the positive meniscus lens 110, the double-concave negative lens 120, the double-convex positive lens 130, the positive meniscus lens 140 and the like, the medium-wave infrared light forms an intermediate image behind (i.e., on the image side) the positive meniscus lens 140; the secondary imaging lens group 150 is disposed behind the intermediate image. In the following detailed description, the intermediate image is preferably formed 21.29mm behind the meniscus positive lens 140, and the secondary imaging lens 150 set is disposed 3.13mm behind the intermediate image, which makes the medium wave infrared zoom lens structure more compact.
The secondary imaging lens group 150 includes a second meniscus lens 152 of positive power convex to the image side and a first meniscus lens 151 of positive power convex to the image side on the image side of the second meniscus lens 152. The first meniscus lens 151 and the second meniscus lens 152 are both germanium lenses, and further preferably germanium crystal lenses, which are convenient for processing and production and have stable optical quality. The front surface 1511 (i.e., the object side surface) of the first meniscus lens 151 is a diffractive surface machined on a even-order aspheric base (i.e., the front surface 1511 has a basic even-order aspheric surface and a diffractive surface machined on the basis), and the back surface 1512 thereof is a spherical surface. The front surface 1521 (i.e., the object side surface) of the second meniscus lens 152 is an even aspheric surface, and the back surface 1522 thereof is a spherical surface. The secondary imaging lens group 150 can be used for focusing and compensating the drift of a focal plane in real time along with the temperature change, so that the heat dissipation difference of-40 ℃ to 80 ℃ is realized (the imaging definition can be still kept within the temperature range of-40 ℃ to 80 ℃), and therefore, the medium-wave infrared continuous zoom lens has good heat dissipation difference capacity and can also be called a compact heat dissipation difference medium-wave infrared continuous zoom lens.
In this embodiment, the lens uses six lenses in total, all of which are made of crystal materials, and the diffraction surfaces of the rear fixed group 140 and the first meniscus lens 151 correct various aberrations well, so that the optical system has good quality, and compact thermal aberration elimination medium wave infrared continuous zooming high-definition imaging can be realized.
The equation of the even aspheric surface related in the embodiment of the invention is as follows:
in the formula, Z is a distance rise from a vertex of the aspherical surface when the aspherical surface is at a position having a height h in the optical axis direction. c is 1/r, r represents the radius of curvature of the mirror surface, k is conic coefficient, and A, B, C, D is a high-order aspheric coefficient.
The equation for the diffraction surface involved in the embodiments of the present invention is:
φ(h)＝α1h2+α2h4+…
wherein alpha is1、α2Is the diffraction coefficient.
According to the above equation and the spherical equation, the parameters of the embodiment of the present invention are as follows:
table 1, optical structure parameters of the inventive examples:
table 2, aspherical coefficients of examples of the present invention (surface numbers are the same as in table 1):
table 3, diffraction surface coefficients of the inventive examples (surface numbers same as table 1):
the lens of the medium-wave infrared continuous zoom lens provided by the embodiment of the invention is compact and has the heat difference eliminating capability, and specific lens parameters are shown in a table 4.
TABLE 4 lens parameters
The embodiment of the invention uses five groups of six lenses together, all the lenses are made of crystal materials, adopts a secondary imaging light path design, reasonably matches lens materials, radiuses, distances and thickness parameters, has an optical total length of only 171.5mm, has a compact structure, realizes a working wave band of 3.4-5.0 mu m and a constant F number of 4.0, has a heat dissipation difference of-40-80 ℃, meets the requirement of 100% of cold diaphragm efficiency, can continuously zoom within a focal length range of 29.4-470 mm, has good imaging quality within a full focus range, and can be simultaneously adapted to refrigeration medium wave infrared detectors of various models, such as a resolution of 640 multiplied by 512, a pixel size of 15 mu m and 20 mu m.
Fig. 4-6 are Modulation Transfer Function curves for the 20 c position for the tele, mid and short focus positions of the preferred embodiment of the present invention, and fig. 7-12 are Modulation Transfer Function curves for the-40 c and 80 c positions for the tele, mid and short focus positions of the preferred embodiment of the present invention. In the figure, the horizontal axis represents spatial frequency, unit: wire pairs per millimeter (lp/mm); and the value of a longitudinal axis surface Modulation Transfer Function (MTF) is used for evaluating the imaging quality of the lens, the value range is 0 to 1.0, the higher the MTF curve is, the straighter the MTF curve is, the better the imaging quality of the lens is, and the stronger the reduction capability of the real image is. As can be seen from fig. 4 to 6, the lens according to the embodiment of the present invention has excellent imaging capability at various focal lengths. As can be seen from FIGS. 7-12, after the lens compensates the drift of the focal plane, the lens assembly can be ensured to clearly image on the whole imaging surface under the environment of-40 ℃ to 80 ℃, and the requirement of poor heat dissipation is met.
Another embodiment of the present invention provides an imaging apparatus, which includes the above-mentioned medium wave infrared zoom lens and a medium wave infrared detector for receiving images formed by the medium wave infrared zoom lens. The medium wave infrared detector converts the image formed by the medium wave infrared continuous zoom lens into an electric signal for subsequent processing, and intelligent processing is realized. The imaging device may be a camera, a pod, or some other device or apparatus.
Further, the medium wave infrared detector is preferably a refrigeration medium wave infrared detector with the resolution of 640 x 512 and the pixel size of 15 μm or 20 μm, so that the adaptability of the imaging device of the embodiment of the invention is improved, and the popularization and the application are facilitated.
The above description is only an embodiment of the present invention, and not intended to limit the scope of the present invention, and all modifications of equivalent structures and equivalent processes performed by the present specification and drawings, or directly or indirectly applied to other related technical fields, are included in the scope of the present invention.
Claims (9)
1. A medium wave infrared continuous zoom lens is characterized in that a front fixed group, a zoom lens group, a compensation lens group, a rear fixed group and a secondary imaging lens group are coaxially and sequentially arranged from an object side to an image side, the front fixed group has positive focal power, the zoom lens group has negative focal power, the compensation lens group has positive focal power, the rear fixed group has positive focal power, the secondary imaging lens group has positive focal power, and the zoom lens group and/or the compensation lens group can axially move to realize continuous zooming;
the front fixed group is a meniscus positive lens with a convex surface facing the object space, the image side surface of the front fixed group is an even-order aspheric surface, and the object side surface is a spherical surface; the zoom lens group is a biconcave negative lens, the image side surface of the biconcave negative lens is an even-order aspheric surface, and the object side surface of the biconcave negative lens is a spherical surface; the compensation lens group is a biconvex positive lens, the object side surface of the biconvex positive lens is an even-order aspheric surface, and the image side surface of the biconvex positive lens is a spherical surface; the rear fixed group is a positive meniscus lens with a convex surface facing an object space, the object space side surface of the positive meniscus lens is a diffraction surface processed on an even-order aspheric substrate, and the image space side surface of the positive meniscus lens is a spherical surface; the secondary imaging lens group comprises a first meniscus lens with positive focal power in a convex direction to an image side and a second meniscus lens with positive focal power in a convex direction to the image side, the first meniscus lens is positioned on the image side, the object side surface of the first meniscus lens is a diffraction surface processed on an even-order aspheric substrate, and the image side surface of the first meniscus lens is a spherical surface; the object side surface of the second meniscus lens is an even-order aspheric surface, and the image side surface of the second meniscus lens is a spherical surface.
2. The medium wave infrared continuous zoom lens of claim 1, wherein the first meniscus lens and the second meniscus lens are both germanium lenses.
3. The medium wave infrared continuous zoom lens of claim 1, characterized by the equation for the even aspheric surface being:
wherein Z is a distance rise from a vertex of the aspherical surface when the aspherical surface has a height h in the optical axis direction, c is 1/r, r represents a curvature radius of the mirror surface, k is a conic coefficient conc, and A, B, C, D is a high-order aspherical coefficient;
alternatively, the equation for the diffractive surface is:
φ(h)＝α1h2+α2h4+…
wherein alpha is1、α2Is the diffraction coefficient.
4. The medium wave infrared zoom lens of claim 3, wherein:
the high-order aspheric coefficients of the equation for the even-order aspheric surfaces of the anterior fixation group are: a is 1.69e-07, B is 2.52e-13, C is-2.09 e-16, D is 2.57 e-20; the high-order aspheric surface coefficient of the equation of the even-order aspheric surface of the zoom lens group is as follows: a is-1.35 e-06, B is-5.82 e-11, C is 5.01e-13, D is-4.26 e-16; the high-order aspheric surface coefficient of the equation of the even-order aspheric surface of the compensation lens group is as follows: a is-5.29 e-07, B is-1.14 e-10, C is 2.52e-13, D is-1.50 e-16; the higher-order aspheric coefficients of the equation for the even-order aspheric surfaces of the post-fixation group are: a is-6.05 e-07, B is-2.85 e-09, C is 1.09e-11, D is-4.31 e-14; the high-order aspheric surface coefficient of the even-order aspheric surface equation of the first meniscus lens is as follows: a is-2.94 e-04, B is 9.81e-06, C is-1.38 e-06, D is 3.51 e-08; the high-order aspheric surface coefficient of the even-order aspheric surface equation of the second meniscus lens is as follows: a is-6.52 e-05, B is 3.63e-07, C is 2.17e-09, D is-5.83 e-11;
alternatively, the diffraction coefficients of the equations for the diffraction surface of the post-fixation set are: alpha is alpha1Is-1.72 e-04, alpha2Is-1.11 e-07; the diffraction coefficient of the equation for the diffractive surface of the first meniscus lens is: alpha is alpha1Is-1.35 e-03, alpha2Is 5.29 e-06.
5. The medium wave infrared zoom lens system of claim 1, wherein the F-number is constant at 4.0, the applicable wavelength band is 3.4 μm to 5.0 μm, and the focal length range of the continuous zooming is 29.4mm to 470 mm.
6. The medium wave infrared continuous zoom lens of claim 1, wherein the rear fixed group forms an intermediate image 21.29mm behind, and the secondary imaging lens group is disposed 3.13mm behind the intermediate image.
7. The medium wave infrared continuous zoom lens of any one of claims 1 to 6, wherein the front fixed group is a meniscus silicon positive lens with a convex surface facing the object; the zoom lens group is a biconcave germanium negative lens; the compensation lens group is a biconvex silicon positive lens; the rear fixed group is a meniscus zinc sulfide or zinc selenide positive lens with a convex surface facing the object space.
8. An imaging apparatus, comprising the medium wave infrared zoom lens system according to any one of claims 1 to 7 and a medium wave infrared detector for receiving an image formed by the medium wave infrared zoom lens system.
9. The imaging apparatus of claim 8, wherein the mid-wave infrared detector is a refrigerated mid-wave infrared detector with a resolution of 640 x 512, a pixel size of 15 μ ι η or 20 μ ι η.
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| CN111897117A (en) * | 2020-08-12 | 2020-11-06 | 长春理工大学 | Ultra-thin medium-long wave infrared dual-waveband imaging system |
| CN112180572B (en) * | 2020-09-30 | 2021-07-27 | 中国科学院西安光学精密机械研究所 | Refrigeration type medium wave infrared athermal optical lens |
| CN113866967B (en) * | 2021-09-07 | 2023-09-01 | 昆明物理研究所 | Low-cost light-weight small-sized medium-wave infrared continuous zooming optical system |
| CN114137699B (en) * | 2021-12-06 | 2024-02-02 | 湖北久之洋红外系统股份有限公司 | Small high-resolution athermalized medium-wave infrared optical system |
| CN114200662A (en) * | 2021-12-21 | 2022-03-18 | 湖南华南光电(集团)有限责任公司 | Athermal infrared collimator optical system |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103345047A (en) * | 2013-07-10 | 2013-10-09 | 北京空间机电研究所 | Light small-size medium-wave infrared continuous zooming imaging lens |
| CN203981958U (en) * | 2014-06-26 | 2014-12-03 | 北京蓝思泰克科技有限公司 | A kind of large zoom ratio medium wave infrared continuous zoom lens |
| CN105425371A (en) * | 2015-12-14 | 2016-03-23 | 福建福光股份有限公司 | Compact medium-wave infrared continuous zoom lens |
| JP2016161701A (en) * | 2015-02-27 | 2016-09-05 | 株式会社タムロン | Infrared lens |
| CN105974566A (en) * | 2016-07-19 | 2016-09-28 | 山东神戎电子股份有限公司 | Large-zoom-ratio turn-back type medium-wave infrared continuous zoom lens |
| KR20160141102A (en) * | 2015-05-28 | 2016-12-08 | (주)토핀스 | 6 un-cooled thermal imaging camera 6 magnification optical zoom lens system |
| CN207216116U (en) * | 2017-08-22 | 2018-04-10 | 三河市蓝思泰克光电科技有限公司 | One kind miniaturization salt free ligands face medium-wave infrared double-view field camera lens |
-
2018
- 2018-12-25 CN CN201811591876.2A patent/CN111367063B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103345047A (en) * | 2013-07-10 | 2013-10-09 | 北京空间机电研究所 | Light small-size medium-wave infrared continuous zooming imaging lens |
| CN203981958U (en) * | 2014-06-26 | 2014-12-03 | 北京蓝思泰克科技有限公司 | A kind of large zoom ratio medium wave infrared continuous zoom lens |
| JP2016161701A (en) * | 2015-02-27 | 2016-09-05 | 株式会社タムロン | Infrared lens |
| KR20160141102A (en) * | 2015-05-28 | 2016-12-08 | (주)토핀스 | 6 un-cooled thermal imaging camera 6 magnification optical zoom lens system |
| CN105425371A (en) * | 2015-12-14 | 2016-03-23 | 福建福光股份有限公司 | Compact medium-wave infrared continuous zoom lens |
| CN105974566A (en) * | 2016-07-19 | 2016-09-28 | 山东神戎电子股份有限公司 | Large-zoom-ratio turn-back type medium-wave infrared continuous zoom lens |
| CN207216116U (en) * | 2017-08-22 | 2018-04-10 | 三河市蓝思泰克光电科技有限公司 | One kind miniaturization salt free ligands face medium-wave infrared double-view field camera lens |
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