CN219320563U

CN219320563U - Triple medium wave infrared microscope lens

Info

Publication number: CN219320563U
Application number: CN202320549421.4U
Authority: CN
Inventors: 戴赋贵; 张增强; 谭勇; 贾耘; 张洪升
Original assignee: Kunming Nan Xu Photoelectric Technologies Co ltd
Current assignee: Kunming Nan Xu Photoelectric Technologies Co ltd
Priority date: 2023-03-20
Filing date: 2023-03-20
Publication date: 2023-07-07
Anticipated expiration: 2033-03-20

Abstract

The utility model discloses a triple medium wave infrared microscope lens, which relates to the technical field of infrared microscope devices, and comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens and an eighth lens which are sequentially arranged from an object space to an image space, wherein the first lens to the sixth lens form a front group of an objective lens, the seventh lens and the eighth lens form a rear group of the objective lens, the working distance is longer, the reasonable distribution of focal power realizes the performance requirements of high resolution, large visual field and the like, and the objective lens realizes the observation of far and near distances through integral focusing; the infrared objective lens has small focal length, large visual field and higher imaging quality.

Description

Triple medium wave infrared microscope lens

Technical Field

The utility model relates to the technical field of infrared microscope devices, in particular to a triple medium wave infrared microscope lens.

Background

The medium wave infrared microscope has important functions in the aspects of circuit board detection, printed board measurement, metal panel detection and the like, and the amplification factor of the infrared microscope is three times optimal according to the size of the detected object and the size of the image surface of the detector. Most of the prior infrared microscopes adopt uncooled infrared optical lenses, and few refrigeration infrared optical lenses are adopted, but the problem faced in developing the refrigeration infrared optical lenses is that the working distance of the lenses is short, and the off-axis aberration is difficult to eliminate, so the utility model provides a triple medium wave infrared microscope lens.

Disclosure of Invention

In order to overcome the problems in the background technology, the utility model provides a triple medium wave infrared microscope lens to solve the problems that the working distance of a refrigeration infrared optical system is short and the off-axis aberration is difficult to eliminate.

In order to achieve the above purpose, the utility model is realized by the following technical scheme:

the three-time medium wave infrared microscope lens comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens and an eighth lens which are sequentially arranged from an object side to an image side, wherein diopter of the first lens is negative, an object side surface is convex, and an image side surface is concave; the diopter of the second lens is positive, the object side surface is a convex surface, and the image side surface is a convex surface; the diopter of the third lens is negative, the object side surface is a concave surface, and the image side surface is a convex surface; the diopter of the fourth lens is positive, the object side surface is a convex surface, and the image side surface is a concave surface; the diopter of the fifth lens is positive, the object side surface is concave, and the image side surface is convex; the diopter of the sixth lens is negative, the object side surface is a convex surface, and the image side surface is a concave surface; the diopter of the seventh lens is negative, the object side surface is a convex surface, and the image side surface is a concave surface; the diopter of the eighth lens is positive, the object side surface is convex, the image side surface is convex, the first lens to the sixth lens form a front objective lens group, and the seventh lens and the eighth lens form a rear objective lens group.

Further, the first lens is a meniscus negative lens.

Further, the first, third, fifth, sixth, seventh and eighth lens surfaces are aspheric.

Further, the triple medium wave infrared microscope lens is a movable fixed focus lens.

Compared with the prior art, the utility model has the beneficial effects that:

the triple medium wave infrared microscope lens adopts a secondary imaging optical system, consists of an objective front group and an objective rear group, realizes long-distance and short-distance observation through integral focusing, and has a longer working distance; the relative illumination of the field of view of the traditional optical system is sharply reduced along with the enlargement of the field of view, so that the uniformity of the illumination of the image plane is reduced, and the optical structure of the lens provided by the utility model has the advantages that the included angle between off-axis light and the optical axis is obviously reduced after the off-axis light passes through the first lens, the aberration correction of the subsequent optical element is facilitated, the generated distortion is smaller, and the uniformity of the illumination of the image plane is improved; the lens of the utility model simplifies the optical structure form while ensuring the image quality, has less lenses and smaller volume of the whole objective lens, and is convenient for use, operation and application range.

Drawings

For the purpose of clearly illustrating the technical solutions in the embodiments of the present utility model, the drawings that are required to be used in the description of the embodiments will be described.

Fig. 1 is a schematic diagram of the overall structure of the present utility model.

FIG. 2 is a graph of the optical transfer function (MTF) at 20℃for the present utility model;

FIG. 3 is a plot of diffuse plaques at 20℃according to the present utility model;

FIG. 4 is a graph of the distortion of the present utility model at 20 ℃.

Detailed Description

In order to make the objects, technical solutions and advantageous effects of the present utility model more apparent, preferred embodiments of the present utility model will be described in detail below with reference to the accompanying drawings, so as to facilitate understanding of the skilled person.

This example is an example of the utility model applied to a refrigerated infrared detector with a resolution of 640 x 512, a pixel size of 15 μm, and a temperature in the range of-40 ℃ to +50 ℃.

Fig. 1 shows the focal length f of the present utility model: 6.8mm, F number: 3.0, field of view: 3.2mm by 2.6mm optical system diagram. Referring to fig. 1, a triple medium wave infrared microscope lens includes a first lens 1, a second lens 2, a third lens 3, a fourth lens 4, a fifth lens 5, a sixth lens 6, a seventh lens 7, and an eighth lens 8, which are sequentially arranged from an object side to an image side, wherein diopter of the first lens 1 is negative, an object side is convex, and an image side is concave; the diopter of the second lens element 2 is positive, the object-side surface is convex, and the image-side surface is convex; the diopter of the third lens 3 is negative, the object side surface is concave, and the image side surface is convex; the diopter of the fourth lens element 4 is positive, the object-side surface is convex, and the image-side surface is concave; the diopter of the fifth lens element 5 is positive, the object-side surface is concave, and the image-side surface is convex; the diopter of the sixth lens element 6 is negative, the object-side surface is convex, and the image-side surface is concave; the diopter of the seventh lens 7 is negative, the object side surface is a convex surface, and the image side surface is a concave surface; the diopter of the eighth lens 8 is positive, the object side surface is convex, the image side surface is convex, the first lens 1 to the sixth lens 6 form a front objective lens group, and the seventh lens 7 and the eighth lens 8 form a rear objective lens group.

The design of the front objective lens group and the rear objective lens group can realize longer working distance, the first lens 1 is a meniscus negative lens, light rays can be effectively contracted, the size of a lens is reduced, the second lens 2 is a biconvex positive lens, field curvature and distortion can be effectively corrected, the third lens 3 is a concave-convex negative lens, spherical aberration can be effectively corrected, the focal power of the first lens 1 of the lens is negative, the focal power of the second lens 2 is positive, the focal power of the third lens 3 is negative, after the off-axis light rays pass through the first lens, the included angle between the off-axis light rays and an optical axis is obviously reduced, aberration correction of a subsequent optical element is facilitated, the focal power of the fourth lens 4 is positive, and the light rays can be effectively contracted; the focal power of the fifth lens 5 is positive, and the focal power of the sixth lens 6 is negative, so that spherical aberration and distortion can be corrected; the focal power of the seventh lens 7 is negative, the focal power of the eighth lens 8 is positive, the seventh lens 7 and the eighth lens 8 are combined into a group, the cold screen efficiency of 100% is realized, and the aberration of the optical system is corrected to a certain extent.

Referring to fig. 1, the surfaces of the first lens element 1, the third lens element 3, the fifth lens element 5, the sixth lens element 6, the seventh lens element 7 and the eighth lens element 8 are aspheric, so that the image quality can be improved, and the influence of temperature change on the image quality can be improved.

Illustratively, table 1 lists the aspherical coefficients of the surface S2 of the first lens 1, the surface S5 of the third lens 3, the surface S9 of the fifth lens 5, the surface S11 of the sixth lens 6, the surface S13 of the seventh lens 7, and the surface S15 of the eighth lens 8.

Surface of the body	K	A	B	C	D
						S2	0	-9.15922E-08	2.44965E-11	-3.51130E-15	1.77952E-18
S5	0	-1.70331E-07	1.33290E-11	1.41629E-16	1.38090E-18
						S9	0	-9.83648E-06	-2.49405E-09	3.04943E-12	-9.09817E-15
S11	0	1.80983E-05	3.38684E-07	-4.51128E-09	1.25923E-10
						S13	0	1.04533E-04	-7.58512E-07	6.78943E-09	-3.38209E-11
S15	0	-7.56241E-05	2.85295E-07	-2.22639E-09	8.21774E-12

Table 1: aspheric coefficients of surfaces S2, S5, S9, S11, S13, S15

The even aspherical equation is defined as follows:

the embodiment achieves good imaging quality by adopting 6 aspheric surfaces, has good manufacturability, can reduce the number of lenses and reduces the cost.

Fig. 2 to 4 are graphs of image optical simulation data of the 3-fold medium wave infrared microscope at 20 ℃, wherein fig. 2 is an optical transfer function (MTF) graph, the horizontal axis is logarithmic per millimeter line (lp/mm), the vertical axis is contrast value, fig. 3 is a dot column graph, and fig. 4 is a distortion graph. From the graph curves of fig. 2 to 4, it can be seen that the MTF, the root mean square value of the diffuse speck and the distortion at the temperature of 20 ℃ are all in the standard range, and the system requirements are satisfied.

Therefore, the three-time medium wave infrared microscope has good imaging quality.

Finally, it is noted that the above-mentioned preferred embodiments are only intended to illustrate rather than limit the utility model, and that, although the utility model has been described in detail by means of the above-mentioned preferred embodiments, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the utility model as defined by the appended claims.

Claims

1. The triple medium wave infrared microscope lens is characterized in that: the triple medium wave infrared microscope lens comprises a first lens (1), a second lens (2), a third lens (3), a fourth lens (4), a fifth lens (5), a sixth lens (6), a seventh lens (7) and an eighth lens (8) which are sequentially arranged from an object space to an image space, wherein diopter of the first lens (1) is negative, an object side surface is convex, and an image side surface is concave; the diopter of the second lens (2) is positive, the object side surface is a convex surface, and the image side surface is a convex surface; the diopter of the third lens (3) is negative, the object side surface is concave, and the image side surface is convex; the diopter of the fourth lens (4) is positive, the object side surface is a convex surface, and the image side surface is a concave surface; the diopter of the fifth lens (5) is positive, the object side surface is concave, and the image side surface is convex; the diopter of the sixth lens (6) is negative, the object side surface is a convex surface, and the image side surface is a concave surface; the diopter of the seventh lens (7) is negative, the object side surface is a convex surface, and the image side surface is a concave surface; the diopter of the eighth lens (8) is positive, the object side surface is a convex surface, the image side surface is a convex surface, the first lens (1) to the sixth lens (6) form a front objective lens group, and the seventh lens (7) and the eighth lens (8) form a rear objective lens group.

2. The triple medium wave infrared microscope lens of claim 1, wherein: the first lens (1) is a meniscus negative lens.

3. The triple medium wave infrared microscope lens of claim 1, wherein: the surfaces of the first lens (1), the third lens (3), the fifth lens (5), the sixth lens (6), the seventh lens (7) and the eighth lens (8) are aspheric.

4. The triple medium wave infrared microscope lens of claim 1, wherein: the triple medium wave infrared microscope lens is a movable fixed focus lens.