CN214795410U

CN214795410U - Infrared endoscope objective optical system suitable for flowing blood imaging

Info

Publication number: CN214795410U
Application number: CN202120616311.6U
Authority: CN
Inventors: 刘顺; 张群雁; 敖建鹏; 王文硕; 季敏标; 魏来; 王春生
Original assignee: Zhongshan Hospital Fudan University
Current assignee: Zhongshan Hospital Fudan University
Priority date: 2021-03-26
Filing date: 2021-03-26
Publication date: 2021-11-19
Anticipated expiration: 2031-03-26

Abstract

The utility model provides an infrared endoscope objective optical system who is suitable for formation of image of flowing blood, a serial communication port, by along first lens, second lens, third lens, diaphragm, fourth lens, fifth lens, sixth lens and the seventh lens that the optical axis set gradually from the object plane to image plane constitute, wherein, first lens and second lens and fourth lens and fifth lens are two cemented lens. The utility model discloses an optimization of lens structure has realized great angle of vision (the angle of vision can reach 65 degrees), 3.3's F number under the circumstances that guarantees compact structure, lens number are few. The utility model discloses can with the fine coupling of follow-up formation of image optic fibre bundle, and all lenses all adopt spherical structure, have reduced the processing degree of difficulty and cost.

Description

Infrared endoscope objective optical system suitable for flowing blood imaging

Technical Field

The utility model relates to an infrared endoscope objective optical system suitable for flowing blood imaging, which belongs to the technical field of medical instruments.

Background

The endoscope technology which combines modern optical, precision mechanical and electronic technologies into a whole is widely applied since the invention is disclosed, so that the nondestructive detection is provided without disassembling or stopping the equipment in industrial production, a plurality of categories such as oral endoscopes, laparoscopes, ear-nose-throat endoscopes and the like are developed in the medical field, and the detection rate of pathological changes and the capability after healing operations are effectively improved.

Endoscopes are usually placed in a medium with low scattering and weak absorption such as air, so that a good imaging effect can be achieved by using visible light as a light source, but the use requirement under certain specific solution environments cannot be met. In the medical field, with the continuous development of interventional operation technology, people have begun to use near infrared light as a light source for imaging in blood environment. Since the absorption and scattering coefficients of visible light in such media are large, efficient light transmission is difficult to achieve, and imaging of the target substance is impossible. To solve this problem, the relevant personnel have proposed new endoscopes based on infrared light sources. The endoscope uses infrared laser in a near infrared band as a light source of the endoscope, and realizes visualization in a blood environment.

At present, the main endoscope in the market mainly takes visible light as a light source, and related matched optical elements such as an objective lens and the like can only support the visible light, so that the endoscope taking infrared laser as the light source has no usable objective lens, and an optical imaging system cannot be separated from an objective lens part.

Disclosure of Invention

The utility model aims at: the objective lens part is compact in structure, low in cost and capable of working in a near infrared band.

In order to achieve the above object, the present invention provides an infrared endoscope objective optical system suitable for imaging flowing blood, which is characterized in that the system comprises a first lens, a second lens, a third lens, a diaphragm, a fourth lens, a fifth lens, a sixth lens and a seventh lens, which are sequentially arranged from an object plane to an image plane along an optical axis, wherein the first lens and the second lens, and the fourth lens and the fifth lens are double-cemented lenses; defining one surface of the first lens facing the object plane as a first surface, and defining one surface facing the image plane as a second surface, and defining one surface of the second lens facing the object plane as a second surface; defining one surface of the second lens facing the image surface as a third surface; defining one surface of the third lens, which faces the object plane, as a fourth surface, and defining one surface of the third lens, which faces the image plane, as a fifth surface; defining one surface of the fourth lens, which faces the object plane, as a sixth surface, and defining one surface of the fourth lens, which faces the image plane, as a seventh surface, and defining one surface of the fifth lens, which faces the object plane, as a seventh surface; defining one surface of the fifth lens facing the image surface as an eighth surface; defining one surface of the sixth lens, which faces the object plane, as a ninth surface, and defining one surface of the sixth lens, which faces the image plane, as a tenth surface; defining a surface of the seventh lens facing the object plane as an eleventh surface, and defining a surface facing the image plane as a twelfth surface, wherein:

the focal power of the first lens is 0, the first lens is a plane lens, and the first surface and the second surface are both planes;

the focal power of the second lens is negative, and the third surface is a concave surface with the curvature radius equal to 1.401 mm;

the third lens power is positive, the fourth surface is convex with a radius of curvature equal to 17.626mm, the fifth surface 32 is convex with a radius of curvature equal to-2.376 mm;

the focal power of the fourth lens is negative, the sixth surface is a concave surface with the curvature radius equal to-1.735 mm, and the seventh surface is a concave surface with the curvature radius equal to 11.271 mm;

the focal power of the fifth lens is positive, and the eighth surface is a convex surface with the curvature radius equal to-3.384 mm;

the sixth lens power is positive, the ninth surface is a convex surface with the radius of curvature equal to 8.435mm, and the tenth surface is a convex surface with the radius of curvature equal to-15.917 mm;

the seventh lens power is positive, the eleventh surface is convex with a radius of curvature equal to 3.798mm, and the twelfth surface is concave with a radius of curvature equal to 13.831 mm.

Preferably, the focal length of the second lens is-2.881 mm; the focal length of the third lens is 2.682 mm; the focal length of the fourth lens is-2.735 mm; the focal length of the fifth lens is 4.516 mm; the focal length of the sixth lens is 9.360 mm; the focal length of the seventh lens is 10.330 mm.

Preferably, the first lens has a refractive index of 1.448 and a central thickness of 0.500 mm; the refractive index of the second lens is 1.489, and the central thickness is 0.292 mm; the refractive index of the third lens is 1.87, and the center thickness of the third lens is 4.402 mm; the refractive index of the fourth lens is 1.543, and the center thickness is 0.778 mm; the refractive index of the fifth lens is 1.605, and the central thickness of the fifth lens is 1.607 mm; the refractive index of the sixth lens is 1.605, and the central thickness of the sixth lens is 1.296 mm; the refractive index of the seventh lens is 1.489, and the center thickness is 1.296 mm.

Preferably, the first lens has a center thickness of 0.500 mm; the central thickness of the second lens is 0.292 mm; the center thickness of the third lens is 4.402 mm; the center thickness of the fourth lens is 0.778 mm; the center thickness of the fifth lens is 1.607 mm; the center thickness of the sixth lens is 1.296 mm; the center thickness of the seventh lens is 1.296 mm.

Preferably, the clear aperture of the diaphragm is less than 1 mm.

Preferably, the aperture sizes of the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens and the seventh lens are all less than 5mm, and the optical cylinder length is less than 25 mm.

Preferably, the working wave band of the infrared endoscope objective optical system is 0.8-2.0 microns.

The utility model discloses an optimization of lens structure has realized great angle of vision (the angle of vision can reach 65 degrees), 3.3's F number under the circumstances that guarantees compact structure, lens number are few. The utility model discloses can with the fine coupling of follow-up formation of image optic fibre bundle, and all lenses all adopt spherical structure, have reduced the processing degree of difficulty and cost.

Compared with the prior art, the utility model has the advantages of it is following and beneficial effect:

1. the utility model discloses to being suitable for the special work demand of infrared endoscope of flowing blood, the objective optical system of an adaptation with it has been optimized in design, through ZEMAX simulation, based on the formation of image index of the near-infrared laser that can support the near-infrared wave band completely, has not only realized the effective coupling of this system and follow-up formation of image optic fibre bundle, has strict controlling to the system size moreover, accomplishes the small and exquisite compactness of structure.

2. The utility model discloses a be suitable for infrared endoscope objective optical system of flowing blood formation of image, lens all adopt the spherical design, have reduced the processing degree of difficulty and cost, are favorable to the scale to use widely.

Drawings

FIG. 1 is a schematic structural diagram of an infrared endoscope objective optical system suitable for imaging flowing blood according to the present invention;

FIG. 2 is a simulation diagram of MTF optical transfer function curve of the objective lens according to an embodiment of the present invention;

FIG. 3 is a diffuse speckle simulation diagram of an objective lens according to an embodiment of the present invention;

FIG. 4 is a diagram illustrating simulated diffraction trapping energy of an objective lens according to an embodiment of the present invention.

In the figure: a is an object plane, B is an image plane, 1 is a first lens, 2 is a second lens, 3 is a third lens, 4 is a stop, 5 is a fourth lens, 6 is a fifth lens, 7 is a sixth lens, 8 is a seventh lens, 11 is a first surface, 12 is a second surface, 21 is a third surface, 31 is a fourth surface, 32 is a fifth surface, 51 is a sixth surface, 52 is a seventh surface, 61 is an eighth surface, 71 is a ninth surface, 72 is a tenth surface, 81 is an eleventh surface, and 82 is a twelfth surface.

Detailed Description

The present invention will be further described with reference to the following specific examples. It should be understood that these examples are for illustrative purposes only and are not intended to limit the scope of the present invention. Furthermore, it should be understood that various changes and modifications of the present invention may be made by those skilled in the art after reading the teachings of the present invention, and these equivalents also fall within the scope of the appended claims.

The utility model provides an infrared endoscope objective optical system, its structure is shown in figure 1, comprises first lens 1, second lens 2, third lens 3, diaphragm 4, fourth lens 5, fifth lens 6, sixth lens 7 and seventh lens 8 that follow the optical axis and set gradually from object plane A to image plane B.

The first lens 1 and the second lens 2 are double-cemented lenses, and the fourth lens 5 and the fifth lens 6 are double-cemented lenses, so that the aberration of the system is reduced, and the imaging quality is improved. A face of the first lens 1 facing the object plane is defined as a first surface 11, and a face facing the image plane is defined as a second surface 12. The surface of the second lens 2 facing the object plane is defined as a second surface 12, and the surface of the second lens 2 facing the image plane is defined as a third surface 21. A face of the third lens 3 facing the object plane is defined as a fourth surface 31, and a face facing the image plane is defined as a fifth surface 32. A face of the fourth lens 5 facing the object plane is defined as a sixth surface 51, and a face facing the image plane is defined as a seventh surface 52. A surface of the fifth lens 6 facing the object plane is a seventh surface 52, and a surface of the fifth lens 6 facing the image plane is defined as an eighth surface 61. A surface of the sixth lens 7 facing the object plane is defined as a ninth surface 71, and a surface facing the image plane is defined as a tenth surface 72. A face of the seventh lens 8 facing the object plane is defined as an eleventh surface 81, and a face facing the image plane is defined as a twelfth surface 82.

The first lens 1 has an optical power of 0 and is a planar lens, and the first surface 11 and the second surface 12 are both planar. The first lens 1 is made of SILICA and has a refractive index of 1.448. The central thickness of the first lens 1 is 0.500 mm.

The second lens element 2 has negative power and a focal length of-2.881 mm, and its third surface 21 is concave with a radius of curvature of 1.401 mm. The second lens 2 is made of N-PK52A and has a refractive index of 1.489. The central thickness of the second lens 2 is 0.292 mm.

The third lens element 3 has positive power and a focal length of 2.682mm, and has a convex fourth surface 31 with a radius of curvature equal to 17.626mm and a convex fifth surface 32 with a radius of curvature equal to-2.376 mm. The third lens element 3 is made of SF66 and has a refractive index of 1.876. The third lens 3 has a central thickness of 4.402 mm.

The fourth lens element 5 has negative power and a focal length of-2.735 mm, and has a concave sixth surface 51 with a radius of curvature equal to-1.735 mm and a concave seventh surface 52 with a radius of curvature equal to 11.271 mm. The fourth lens element 5 is made of N-KZFS2 and has a refractive index of 1.543. The central thickness of the fourth lens 5 is 0.778 mm.

The fifth lens element 6 has positive power and a focal length of 4.516mm, and has a convex eighth surface 61 with a radius of curvature of-3.384 mm. The fifth lens 6 is made of N-PSK53A and has a refractive index of 1.605. The central thickness of the fifth lens 6 is 1.607 mm.

The sixth lens element 7 has positive power and a focal length of 9.360mm, and has a ninth surface 71 having a convex curvature radius of 8.435mm and a tenth surface 72 having a convex curvature radius of-15.917 mm. The sixth lens 7 is made of N-PSK53A and has a refractive index of 1.605. The center thickness of the sixth lens 7 is 1.296 mm.

The seventh lens element 8 has positive power and a focal length of 10.330mm, and has an eleventh surface 81 having a radius of curvature equal to 3.798mm and a twelfth surface 82 having a radius of curvature equal to 13.831 mm. The seventh lens 8 is made of N-PK52A and has a refractive index of 1.489. The central thickness of the seventh lens 8 is 1.296 mm.

The clear aperture of the diaphragm 4 is less than 1 mm.

The working waveband of the objective optical system is 0.8-2.0 microns, and the spectral coverage is wide. Meanwhile, in order to ensure that the whole objective optical system is small and compact in structure, the caliber sizes of the first lens 1, the second lens 2, the third lens 3, the fourth lens 5, the fifth lens 6, the sixth lens 7 and the seventh lens 8 are all smaller than 5mm, and the optical cylinder length is smaller than 25 mm. When the object plane a is 5.000mm from the first surface 11, the image plane B is 1.371mm behind the twelfth surface 82 and the cover diameter of the image plane is 3 mm.

In order to simulate the liquid environment of the infrared endoscope with the objective lens adapted to the liquid environment, the distance between the object plane A and the first surface 11 is 5mm, and seawater with the refractive index of 1.329 is filled in the middle to be used as a medium. The subsequent imaging fiber bundle was composed of 10000 fiber filaments with a diameter of 27.5 μm in a hexagonal spiral manner.

As shown in fig. 2, the full field angle MTF of the objective optical system disclosed in the present embodiment is greater than 0.7 at a cutoff frequency of 30 lp/mm.

As shown in fig. 3, the objective optical system disclosed in this embodiment has a diffuse speckle root-mean-square size of less than 2.9 μm and less than 27.5 μm of the diameter of a single optical fiber in the imaging optical fiber bundle used at the rear.

As shown in fig. 4, the diffraction energy of the full field of view of the objective optical system in this embodiment is higher than 91% in the radius range of 13.75 μm of the single optical fiber, which fully ensures the efficiency of light energy transfer.

The above embodiment is only an implementation manner of the present invention, but the implementation manner of the present invention is not limited by the above embodiment, and any other changes, modifications, substitutions, combinations, and simplifications that do not depart from the spirit and principle of the present invention should be equivalent replacement manners, and all are included in the protection scope of the present invention.

Claims

1. An infrared endoscope objective optical system suitable for imaging flowing blood is characterized by comprising a first lens, a second lens, a third lens, a diaphragm, a fourth lens, a fifth lens, a sixth lens and a seventh lens which are sequentially arranged from an object plane to an image plane along an optical axis, wherein the first lens and the second lens as well as the fourth lens and the fifth lens are double-cemented lenses; defining one surface of the first lens facing the object plane as a first surface, and defining one surface facing the image plane as a second surface, and defining one surface of the second lens facing the object plane as a second surface; defining one surface of the second lens facing the image surface as a third surface; defining one surface of the third lens, which faces the object plane, as a fourth surface, and defining one surface of the third lens, which faces the image plane, as a fifth surface; defining one surface of the fourth lens, which faces the object plane, as a sixth surface, and defining one surface of the fourth lens, which faces the image plane, as a seventh surface, and defining one surface of the fifth lens, which faces the object plane, as a seventh surface; defining one surface of the fifth lens facing the image surface as an eighth surface; defining one surface of the sixth lens, which faces the object plane, as a ninth surface, and defining one surface of the sixth lens, which faces the image plane, as a tenth surface; defining a surface of the seventh lens facing the object plane as an eleventh surface, and defining a surface facing the image plane as a twelfth surface, wherein:

the seventh lens power is positive, the eleventh surface is a convex surface with a radius of curvature equal to 3.798mm, and the twelfth surface is a concave surface with a radius of curvature equal to 13.831 mm;

the focal length of the second lens is-2.881 mm; the focal length of the third lens is 2.682 mm; the focal length of the fourth lens is-2.735 mm; the focal length of the fifth lens is 4.516 mm; the focal length of the sixth lens is 9.360 mm; the focal length of the seventh lens is 10.330 mm;

the refractive index of the first lens is 1.448, and the central thickness of the first lens is 0.500 mm; the refractive index of the second lens is 1.489, and the central thickness is 0.292 mm; the refractive index of the third lens is 1.87, and the center thickness of the third lens is 4.402 mm; the refractive index of the fourth lens is 1.543, and the center thickness is 0.778 mm; the refractive index of the fifth lens is 1.605, and the central thickness of the fifth lens is 1.607 mm; the refractive index of the sixth lens is 1.605, and the central thickness of the sixth lens is 1.296 mm; the refractive index of the seventh lens is 1.489, and the center thickness is 1.296 mm.

2. The infrared endoscope objective optical system suitable for imaging flowing blood as set forth in claim 1, wherein the aperture of the diaphragm is smaller than 1 mm.

3. The infrared endoscope objective optical system suitable for flowing blood imaging as recited in claim 1, wherein the aperture sizes of the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens and the seventh lens are all less than 5mm, and the optical cylinder length is less than 25 mm.

4. The infrared endoscope objective optical system suitable for imaging flowing blood as set forth in claim 1, wherein the infrared endoscope objective optical system has an operating band of 0.8-2.0 μm.