CN210072178U

CN210072178U - Medium wave refrigeration continuous zooming infrared lens

Info

Publication number: CN210072178U
Application number: CN201920543115.3U
Authority: CN
Inventors: 周隆梅; 曹雪娇
Original assignee: Hebei Hanguang Heavy Industry Ltd
Current assignee: Hebei Hanguang Heavy Industry Ltd
Priority date: 2019-04-19
Filing date: 2019-04-19
Publication date: 2020-02-14
Anticipated expiration: 2029-04-19

Abstract

The utility model provides a medium wave refrigeration zoom infrared camera lens in succession, lens figure is few, realizes high quality formation of image through less volume and weight. The utility model meets the requirement of the medium wave refrigeration type continuous zoom lens through the combination of simple optical structure and material; the change of the parfocalization caused by the temperature change is compensated through the focusing group, and the use requirement of wider working temperature is met; the aperture of the infrared lens is effectively compressed through the secondary imaging infrared lens, so that the volume and the weight of the infrared lens are reduced, and the requirement of the handheld device on the continuous zooming infrared lens is finally met. The utility model is simple, effective and highly practical, and can realize the requirement of infrared lens for infrared continuous zooming through fewer lenses; the equipment with the required volume and weight is met through smaller volume and weight; through less lenses, the high infrared lens transmittance and the high resolution are realized, and the requirement on long acting distance is finally met.

Description

Medium wave refrigeration continuous zooming infrared lens

Technical Field

The utility model relates to an optical lens technical field, concretely relates to infrared camera lens of zooming in succession of medium wave refrigeration for handheld device.

Background

In recent years, infrared detection techniques such as infrared thermal imaging have been widely used in military, industrial, and civil fields. For the detector, the uncooled detector has the advantages of low price, small volume, light weight, low power consumption and the like, but the sensitivity is low, the medium wave refrigeration detector has more obvious advantage than a long wave detector of the same type due to high sensitivity, and the medium wave refrigeration infrared lens has good application prospect in the handheld infrared observation instrument equipment in order to meet the requirement of searching and tracking a long-distance target.

The fixed-focus infrared lens is wide in use and simple in design, but cannot meet the requirements of large-view-field searching and small-view-field tracking or identification, so that the use is limited; the infrared lens with double view fields or multiple view fields can meet the requirements of large view field searching and small view field tracking or identification, but a target is lost easily during view field switching during use, so that the use is defective; the continuous zooming infrared lens can meet the requirements of large-view-field searching and small-view-field tracking or identification, can keep a target continuously enlarged or reduced in the zooming process, and has great advantages in use, so that the continuous zooming infrared lens has good use prospect on handheld equipment. The number of glass sheets used by the existing medium-wave continuous zooming optical infrared lens (such as patents CN102213822A, P2002-14283A and US7092150B1) is about 7 to 12, and the existing medium-wave continuous zooming optical infrared lens has the defects of large glass quantity and large processing difficulty, increases the cost and the weight of the infrared lens, reduces the transmittance of the infrared lens, and further reduces the acting distance of the infrared lens.

SUMMERY OF THE UTILITY MODEL

In view of this, the utility model provides a medium wave refrigeration zoom infrared camera lens in succession, the lens figure is few, realizes high quality formation of image through less volume and weight.

In order to achieve the above object, the utility model discloses a medium wave refrigeration continuous zooming infrared lens, which comprises a front group, a zoom group, a compensation group, a focusing group, an image transfer component and a secondary imaging group, wherein the front group only comprises a lens and adopts a single crystal germanium material; the front surface of the lens is a diffraction structure and an aspheric surface structure;

the zoom group is made of single crystal silicon materials, and the ratio of the focal length f2 of the zoom group to the focal length fL of the continuous zoom infrared lens in the longest focus state meets f2/fL which is more than or equal to 0.1 and less than or equal to 0.2;

the compensation group only comprises one lens and adopts a single crystal germanium material; the rear surface of the lens is of a diffraction structure and an aspheric structure, and the surface shape is curved back to the image surface;

the focusing group is made of zinc selenide, the focusing requirements of different far and near targets are met by changing the position of the focusing group relative to the front group, and the change of the parfocal property of the infrared lens caused by expansion with heat and contraction with cold due to the temperature change of the infrared material within the range of-40 ℃ to 60 ℃ is compensated.

The image rotating component comprises a plane reflector I and a plane reflector II and rotates the light path 180 degrees.

The primary image surface of the lens is positioned between the plane reflector I and the secondary imaging group, and the distances between the primary image surface of the lens and the lens surfaces of the plane reflector I and the secondary imaging group are both larger than or equal to 5 mm.

Wherein, the magnification β of the secondary imaging group satisfies 0.5- β -0.8.

Has the advantages that:

1. the utility model meets the requirement of the medium wave refrigeration type continuous zoom lens through the combination of simple optical structure and material; the change of the parfocalization caused by the temperature change is compensated through the focusing group, and the use requirement of wider working temperature is met; through secondary imaging, the infrared lens effectively compresses the caliber of the infrared lens, so that the volume and the weight of the infrared lens are reduced, and finally the requirement of the handheld device on the continuous zooming infrared lens is met. The utility model is simple, effective and highly practical, and can realize the requirement of infrared lens for infrared continuous zooming through fewer lenses; the equipment with the required volume and weight is met through smaller volume and weight; the infrared camera lens has the advantages that the infrared camera lens has high transmittance and high resolution ratio through fewer lenses, and finally the requirement for long acting distance is met;

2. the utility model discloses can use handheld infrared observation appearance, the nacelle, photoelectric tracking appearance, photoelectric monitoring revolving stage/cloud platform etc. on multiple equipment.

Drawings

FIG. 1 is a prior art continuous zoom infrared composition example;

FIG. 2 is an exemplary continuous zoom infrared short focus of the present invention;

FIG. 3 is an exemplary continuous zoom infrared mid-focus of the present invention;

FIG. 4 is an exemplary continuous zoom infrared tele of the present invention;

fig. 5 is an example of the continuous zooming infrared zooming curve of the present invention.

Detailed Description

The present invention will be described in detail below with reference to the drawings and examples.

The utility model provides a medium wave refrigeration infrared optical lens that zooms in succession is applicable to 640 x 512 specification medium wave refrigeration detector, on improving the basis of surveying the working distance and improving the image quality as far as possible, adopts secondary imaging's mode, and the single lens zooms, and the single lens compensation focuses on to reduce cost and infrared camera lens volume make simple structure, and the motion load is little. In order to realize the continuous change of the focal length, the scheme comprises a front group, a zoom group, a compensation group, a focusing group, a secondary imaging group and a relay imaging component. Wherein the zooming and compensating group realizes the zooming requirement of the infrared lens; the focusing group realizes the focusing requirements on different far and near targets, and simultaneously designs the compensation focusing amount requirements under different temperature requirements, and as the service temperature of the handheld equipment is wider, generally ranging from-40 ℃ to 60 ℃, and the temperature expansion coefficient of the infrared material is higher than that of the visible light material by more than one order of magnitude, the focusing group realizes the compensation of the change of the parfocal property of the infrared lens caused by the change of the material and the surface type; the image conversion group can realize light path conversion, conveniently satisfies the restriction to the volume in the handheld device, and the secondary imaging group is used for compressing the bore of the infrared lens, more is favorable to the miniaturization of equipment.

The utility model discloses an aim at adopts simple optical structure, does not use special material and glaze system glass to rectify the colour difference, adopts ripe infrared material and the face type combination, and the focal power and the magnification through the control part component obtain less volume weight, great field of view scope and higher imaging resolution.

The utility model discloses a simple optical structure does not use special material and glaze system glass to rectify the colour difference, adopts ripe infrared material and face type combination, and focal power and magnification through the control part component obtain less volume weight, great field of view scope and higher imaging resolution ratio are applicable to the image device of 640 x 512 specification.

As shown in fig. 1, the lens of the present invention is composed of a front group 1, a zoom group 2, a compensation group 3, a focusing group 4, an image transfer assembly 5, and a secondary imaging group 6. The zooming group 2 and the compensation group 3 realize the zooming requirement of the infrared lens. The focusing group 4 is used for focusing requirements of different object distances, and simultaneously, the focusing group 4 is considered to compensate for changes of parfocal property of the infrared lens caused by expansion with heat and contraction with cold due to temperature changes of the infrared material within the range of-40-60 ℃. The image rotating group 5 realizes 180-degree turning of the light path, increases the utilization efficiency of space and shortens the mechanical total length of the infrared lens. The secondary imaging group 6 realizes a certain magnification ratio of the whole focal length, so that the focal length of the infrared lens meets the requirements of an optical system.

Specifically, as shown in fig. 2 to 4, the optical paths of the continuous zoom infrared lens at the short-focus end, the middle-focus end and the long-focus end are schematic, and the present embodiment includes six lenses to implement zooming, focusing and temperature compensation of the infrared lens.

The secondary imaging group comprises a primary imaging group mirror 6-1 and a secondary imaging group mirror 6-2; the front group and the compensation group adopt monocrystalline germanium, the zoom group 2 and the secondary imaging group one mirror 6-1 adopt monocrystalline silicon, and the focusing group and the secondary imaging group two mirror 6-2 adopt zinc selenide, wherein the front group 1 only comprises one lens, adopts a monocrystalline germanium material, adopts a diffraction structure and an aspheric structure on the front surface, and effectively reduces chromatic aberration and thermal aberration of the infrared lens and shrinks light. The front group 1 adopts a single lens, so that the weight of the infrared lens can be effectively reduced.

The effective focal length control of the zoom group 2 can reduce the length of the infrared lens, the focal length of the zoom group is controlled to be in a relatively short state, and the single crystal silicon material is adopted, so that the larger radius can be obtained, the turning degree of light rays at the zoom group 2 can be reduced, and the subsequent aberration correction can be facilitated. The ratio of the focal length f2 of the zoom group 2 to the focal length fL of the continuous zooming infrared lens in the longest focal state meets f2/fL which is more than or equal to 0.1 and less than or equal to 0.2.

The compensation group 3 is made of a single crystal germanium material, adopts a diffraction structure and an aspheric surface structure on the rear surface, simultaneously compensates the surface type of the group and faces away from the image surface, and is matched with the front group 1 to correct chromatic aberration and thermal aberration of the infrared lens.

The focusing group 4 is made of zinc selenide, the focusing requirements of different far and near targets are realized by changing the position of the focusing group relative to the front group 1, and the change of the parfocal property of the infrared lens caused by expansion with heat and contraction with cold due to the temperature change of the infrared material within the range of-40 ℃ to 60 ℃ is compensated.

The image rotating component 5 comprises a plane reflector I5-1 and a plane reflector II 5-2, and rotates the light path 180 degrees. The plane reflector I5-1 turns the light path by 90 degrees, the plane reflector II 5-2 turns the light path by 90 degrees, thus realizing 180-degree turning of the light path, changing the slender light path, directly changing the direction of the detector, reducing the volume of the infrared lens and enabling the space size of the infrared lens to be more reasonably utilized.

The zoom group 2, the compensation group 3 and the focusing group 4 also need to ensure that under various temperature conditions, the primary image surface of the infrared lens is between the image transfer component 5 and the secondary imaging group 6, is not in the lenses of the image transfer component 5 and the secondary imaging group 6, and needs to be far away from the image transfer lens and the secondary imaging group lens so as to avoid generating irremovable cold reflection, which is beneficial to the whole focal power matching and the lens volume compression. Specifically, the front group 1, the zoom group 2, the compensation group 3 and the focusing group 4 ensure that the primary image surface of the lens is positioned between the plane reflector I5-1 and the first mirror of the secondary imaging group 6-1, and the distance between the primary image surface of the lens and the surface of the plane reflector I5-1 and the surface of the first mirror of the secondary imaging group 6-1 is greater than or equal to 5 mm.

The secondary imaging group 6 cooperates with the zoom group 2, selects the effective bore that suitable magnification can effectively compress the infrared lens front group 1, reduces infrared lens weight and volume the utility model discloses select secondary imaging group magnification 0.5 and be less than or equal to β and be less than or equal to 0.8.

Fig. 5 shows the movement of the zoom group 2 and the compensation group 3 during zooming of the infrared lens.

The utility model discloses a continuous zoom infrared camera lens has reached following technical index: the focal length is 60 mm-180 mm, and the zoom ratio is 3 times; the relative aperture D/f is 1/4; the field angle is 9.1 degrees multiplied by 7.3 degrees to 3 degrees multiplied by 2.4 degrees; adapting 640 x 512 detectors.

In summary, the above is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A medium-wave refrigeration continuous zooming infrared lens comprises a front group (1), a zooming group (2), a compensation group (3), a focusing group (4), an image transfer component (5) and a secondary imaging group (6), and is characterized in that the front group (1) only comprises one lens and is made of a single crystal germanium material; the front surface of the lens is a diffraction structure and an aspheric surface structure;

the zoom group (2) is made of monocrystalline silicon, and the ratio of the focal length f2 of the zoom group (2) to the longest focal length fL of the continuous zooming infrared lens in the state of focus is more than or equal to 0.1 and less than or equal to f2/fL and less than or equal to 0.2;

the compensation group (3) only comprises one lens and adopts a single crystal germanium material; the rear surface of the lens is of a diffraction structure and an aspheric structure, and the surface shape is curved back to the image surface;

the focusing group (4) is made of zinc selenide, the focusing requirements of different far and near targets are met by changing the position of the focusing group relative to the front group (1), and the change of the parfocal property of the infrared lens caused by expansion and contraction due to the temperature change of the infrared material within the range of-40 ℃ to 60 ℃ is compensated.

2. The medium wave refrigeration zoom lens system as claimed in claim 1, wherein the relay assembly (5) comprises a plane mirror I (5-1) and a plane mirror II (5-2) to turn the optical path by 180 °.

3. The medium wave refrigeration zoom lens system as set forth in claim 2, wherein the primary image plane of the lens system is located between the plane mirror I (5-1) and the secondary imaging group (6), and is separated from the lens surfaces of the plane mirror I (5-1) and the secondary imaging group (6) by a distance greater than or equal to 5 mm.

4. The medium wave refrigeration zoom lens system as set forth in claim 1, wherein the magnification β of the secondary imaging group (6) satisfies 0.5 ≦ β ≦ 0.8.