Five-gluing superfine endoscope objective lens optical system

Abstract

The utility model discloses a quintuple gluing superfine endoscope objective lens optical system, which is a quintuple gluing rodlike lens with a concave-convex structure and is formed by sequentially gluing a first concave-convex lens L1, a biconcave lens L2, a convex-concave lens L3, a biconvex lens L4 and a second concave-convex lens L5 which are sequentially arranged from an object space to an image space along a main optical axis, the biconvex lens L4 is a negative-focal-power lens, the biconvex lens L5 is a positive-focal-power lens, the biconvex lens L5 is a negative-focal-power lens, and the biconvex lens L4 is a positive-focal-power lens. The first concave-convex lens L1, the biconcave lens L2, the convex-concave lens L3 and the second concave-convex lens L5 are positive focal power lenses made of different materials. According to the utility model, the diameter is larger than 0.4 mm and smaller than 0.8 mm, and the ultra-thin lens has the advantages of being ultra-thin, easy to install, high in image quality and the like.

Description

TECHNICAL FIELD

[0001] The utility model relates to medical endoscope field, specifically, the utility model relates to a kind of five glue super thin endoscope objective optical system. BACKGROUND

[0002] Endoscope objective optical system is the core component of endoscope imaging system, responsible for obtaining high-definition image, to help doctor clearly observe internal condition of human body. Among them, clear objective optical system is the key factor to guarantee endoscope imaging quality. The design of endoscope objective optical system not only meets the demand of high-resolution imaging, but also needs to adapt to the structure restriction of narrow space and miniaturization. However, the traditional miniaturization endoscope objective structure is limited by length-diameter ratio, and there are many deficiencies, such as insufficient light quantity, low resolution, significant edge brightness attenuation and higher manufacturing cost. In addition, due to its complex optical structure, it contains more prisms and lenses, which is prone to tilt and eccentricity, so that the assembly precision is higher, and the installation process is more complicated. SUMMARY

[0003] In order to solve the above problems existing in the prior art, the utility model provides a kind of five glue super thin endoscope objective optical system, its diameter is greater than 0.4mm less than 0.8mm, with super thin, easy to install, high image quality and other advantages.

[0004] The purpose of the utility model is realized by the following technical scheme:

[0005] A kind of five glue super thin endoscope objective optical system, it is the five glue rod lens of concave-convex structure, first concave-convex lens L1, double concave lens L2, convex-concave lens L3, double convex lens L4, second concave-convex lens L5 are sequentially glued in order from object side to image side along the main optical axis, wherein, double convex lens L4 is negative power lens, first concave-convex lens L1, double concave lens L2, convex-concave lens L3, second concave-convex lens L5 are positive power lenses with different materials.

[0006] Further, the lens used in the five glue super thin endoscope objective optical system is all spherical mirror, and each lens has matching optical parameters.

[0007] Further, the optical parameters of the five glue super thin endoscope objective optical system satisfy the following conditional formula:

[0008] 2.4≤d1 / f≤4.2

[0009] 0.4≤r 11 / r 52 ≤0.8

[0010] 9≤f1 / f≤11

[0011] 1.5≤f2 / f≤3.1

[0012] 0.4≤d1 / d≤0.8

[0013] 0.52≤I h / f≤1.16

[0014] 0.5≤L≤1

[0015]

[0016] In the formula, d1 is the air equivalent length from the object side surface of the five-glued superfine endoscope objective optical system to the diaphragm surface; f is the focal length of the five-glued superfine endoscope objective optical system; r 11 is the curvature radius of the object side surface of the five-glued superfine endoscope objective optical system; r 52 is the curvature radius of the image side surface of the five-glued superfine endoscope objective optical system; f1 is the focal length of the first meniscus lens L1; f2 is the focal length of the double-concave lens L2; d1 is the air equivalent length from the image side surface of the first meniscus lens L1 to the diaphragm surface; d is the total length of the five-glued superfine endoscope objective optical system; L is the working distance of the five-glued superfine endoscope objective optical system; I h is the image height of the five-glued superfine endoscope objective optical system; is the refractive power of the five-glued superfine endoscope objective optical system.

[0017] Further, the five-glued superfine endoscope objective optical system is a five-glued rod lens with a meniscus structure with a diameter greater than 0.4 mm and less than 0.8 mm.

[0018] Further, the total field of view of the five-glued superfine endoscope objective optical system is 50°.

[0019] The utility model has the following advantages:

[0020] The utility model provides a kind of five-glued superfine endoscope objective optical system, replace two optical components of traditional endoscope objective optical system with one optical component, compared with traditional endoscope objective optical system, structure is simpler, reduces processing and adjustment error, significantly increases the length-diameter ratio of optical system, more degree of utilization of the optical size of lens, while significantly reducing the size of endoscope objective, good guarantee the imaging quality of endoscope. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 It is the cross section structure schematic diagram of the superfine five-glued endoscope objective optical system of the utility model embodiment 1;

[0022] Figure 2The point array diagram of each field of view of the image surface of the superfine five-glued endoscope objective optical system according to the utility model embodiment 1;

[0023] Figure 3 The axial aberration curve of each wavelength of the image surface of the superfine five-glued endoscope objective optical system according to the utility model embodiment 1.

[0024] Figure 4 The MTF curve of each field of view of the image surface of the superfine five-glued endoscope objective optical system according to the utility model embodiment 1;

[0025] Figure 5 The distortion curve of each wavelength of the image surface of the superfine five-glued endoscope objective optical system according to the utility model embodiment 1.

[0026] Figure 6 The sectional structure schematic view of the superfine five-glued endoscope objective optical system according to the utility model embodiment 2;

[0027] Figure 7 The point array diagram of each field of view of the image surface of the superfine five-glued endoscope objective optical system according to the utility model embodiment 2;

[0028] Figure 8 The axial aberration curve of each wavelength of the image surface of the superfine five-glued endoscope objective optical system according to the utility model embodiment 2.

[0029] Figure 9 The MTF curve of each field of view of the image surface of the superfine five-glued endoscope objective optical system according to the utility model embodiment 2;

[0030] Figure 10 The distortion curve of each field of view of the image surface of the superfine five-glued endoscope objective optical system according to the utility model embodiment 2;

[0031] In the figure,

[0032] Ax-main optical axis; L1-first concave-convex lens; L2-double concave lens; L3-convex-concave lens; L4-double convex lens; L5-second concave-convex lens. DETAILED DESCRIPTION

[0033] In order to clearly describe the purpose, technical scheme and advantages of the utility model embodiments, the technical scheme in the utility model embodiments will be clearly and completely described below by combining with the drawings and examples.

[0034] The utility model provides a kind of five glue super-thin endoscope objective optical system, it is the five glue rod lens of concave-convex structure with greater than 0.4mm and smaller than 0.8mm diameter, first concave-convex lens L1, double concave lens L2, convex-concave lens L3, double convex lens L4, second concave-convex lens L5 are sequentially glued in order by being sequentially arranged from object side to image side along main optical axis, wherein, double convex lens L4 is negative power lens, first concave-convex lens L1, double concave lens L2, convex-concave lens L3, second concave-convex lens L5 are positive power lens of different materials.The lens used in the five glue super-thin endoscope objective optical system is all spherical mirror, and each lens has compatible optical parameters.

[0035] The utility model discloses in order to form the endoscope objective optical system of small volume big visual angle that can be widely applied in endoscope, configure concave-convex lens L1 in the position closest to object side, to ensure refractive power.The overall structure is a concave-convex structure rod lens, this lens is sequentially glued by five lenses sequentially arranged from object side to image side, and the optical size of lens is used to a greater extent by the glued lens and axial chromatic aberration can be better corrected.

[0036] Further, in the super-thin endoscope, the distance for configuring the field of view angle must be ensured to be relatively long. That is, the length of the first lens relative to the focal length of the optical system must be ensured to be relatively long. Therefore, it is desirable to satisfy the following conditional expression:

[0037] 2.4≤d1 / f≤4.2 (1)

[0038] In the expression, d1 is the air equivalent length from the surface of the object side of the five glue super-thin endoscope objective optical system to the diaphragm surface; and f is the focal length of the entire system of the five glue super-thin endoscope objective optical system.

[0039] Further, the five glue super-thin endoscope objective optical system needs to correct spherical aberration and coma in order to ensure the height and exit angle for imaging, prevent the light height of the lens near the image plane from being too high, and prevent the lens from being too large in diameter. Therefore, it is desirable to satisfy the following conditional expression:

[0040] 0.4≤r 11 / r 52 ≤0.8 (2)

[0041] In the expression, r 11 is the radius of curvature of the surface of the object side of the five glue super-thin endoscope objective optical system; and r 52 is the radius of curvature of the surface of the image side of the five glue super-thin endoscope objective optical system.

[0042] Further, in order to obtain a small and high image quality ultra slim endoscope, it is necessary to appropriately set the focal length of the first meniscus lens L1 and the endoscope objective lens so as to maintain the balance between the lens diameter and the optical performance. Therefore, it is desirable to satisfy the following conditional expression (3).

[0043] 9 ≤ f1 / f ≤ 11 (3)

[0044] In the expression, f1 is the focal length of the first meniscus lens L1; and f is the focal length of the entire system of the five-joint ultra slim endoscope objective lens optical system.

[0045] Further, in order to prevent the ray height of the lens near the image plane from becoming high and the lens diameter from becoming large, it is necessary to set the ratio of the focal length of the biconcave lens L2 to the focal length of the endoscope to be large. Therefore, it is desirable to satisfy the following conditional expression:

[0046] 1.5 ≤ f2 / f ≤ 3.1 (4)

[0047] In the expression, f is the focal length of the entire system of the five-joint ultra slim endoscope objective lens optical system; and f2 is the focal length of the biconcave lens L2.

[0048] Further, in order to both ensure that the first meniscus lens L1 has a long distance for configuring the field angle and control the total length of the endoscope, it is necessary to satisfy the following conditional expression:

[0049] 0.4 ≤ d1 / d ≤ 0.8 (5)

[0050] In the expression, d1 is the air equivalent length from the image side surface of the first meniscus lens L1 to the diaphragm surface; and d is the total length of the five-joint ultra slim endoscope objective lens optical system.

[0051] Further, if the height of the image and the imaging distance of the five-joint ultra slim endoscope objective lens are not appropriate, it is difficult to find a suitable relay system to be adapted thereto. Therefore, in order to adapt to a small diameter relay system, it is necessary to satisfy the following conditional expression:

[0052] 0.52 ≤ I h / f ≤ 1.16 (6)

[0053] 0.5 ≤ L ≤ 1 (7)

[0054] In the expression, f is the focal length of the five-joint ultra slim endoscope objective lens optical system; L is the working distance of the five-joint ultra slim endoscope objective lens optical system; and I h is the image height of the five-joint ultra slim endoscope objective lens optical system.

[0055] Further, the total refractive power of the five-joint ultra slim endoscope objective lens optical system satisfies the following conditional expression:

[0056]

[0057] In the formula, The optical power of the five-ply ultrafine endoscope objective lens optical system is given.

[0058] Example 1

[0059] like Figure 1 As shown, this embodiment comprises a five-layer cemented ultra-fine endoscope objective lens optical system with a concave-convex structure having a diameter greater than 0.4 mm and less than 0.8 mm. It is formed by cementing together a first concave-convex lens L1, a biconcave lens L2, a convex-concave lens L3, a biconvex lens L4, and a second concave-convex lens L5, arranged sequentially from the object side to the image side along the principal optical axis. The biconvex lens L4 is a negative power lens, while the first concave-convex lens L1, the biconcave lens L2, the convex-concave lens L3, and the second concave-convex lens L5 are positive power lenses made of different materials. All lenses used in this five-layer cemented ultra-fine endoscope objective lens optical system are spherical mirrors, and each lens has compatible optical parameters.

[0060] Figures 2 to 5 The image quality parameters for this embodiment are as follows: mTF (Mean Time Limit) is close to the diffraction limit and chromatic aberration-free; the full field of view is 50°; the image height is 0.35; the focal length is 0.454422; and the fno (aperture value) is 5.66172. All lenses in the optical assembly have different radii of curvature, which reduces misalignment during assembly. When the image plane diameter is larger, this five-colloid lens structure can achieve even better image quality while maintaining its original advantages.

[0061] Example 2

[0062] like Figure 6 As shown, this embodiment comprises a five-ply ultra-fine endoscope objective lens optical system with a concave-convex structure having a diameter greater than 0.4 mm and less than 0.8 mm. It is formed by cementing together a first concave-convex lens L1, a biconcave lens L2, a convex-concave lens L3, a biconvex lens L4, and a second concave-convex lens L5, arranged sequentially along the principal optical axis from the object side to the image side. The biconvex lens L4 is a negative power lens, while the first concave-convex lens L1, the biconcave lens L2, the convex-concave lens L3, and the second concave-convex lens L5 are positive power lenses made of different materials. All lenses used are spherical mirrors.

[0063] Figures 7 to 10 The image quality parameters for this embodiment are: mtf close to the diffraction limit and no chromatic aberration, full field of view 50°, image height 0.45, focal length 0.564676, and Fno 7.05783.

[0064] The above detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely represents selected embodiments of the application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort, fall within the scope of the present application.

[0065] It should be noted that like numbers and letters refer to like items throughout the drawings, and once an item is defined in one drawing, it is not necessary to further define and explain it in the subsequent drawings.

[0066] The above description is merely illustrative of the preferred embodiments of the present application and is not intended to limit the scope of the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the scope of the present application.

Claims

1. A five-glued ultra-compact endoscope objective optical system characterized by comprising: It is a five-glued rod-shaped lens with concave-convex structure, which is sequentially glued by a first concave-convex lens L1, a double-concave lens L2, a convex-concave lens L3, a double-convex lens L4 and a second concave-convex lens L5 arranged in order from the object side to the image side along the main optical axis, wherein the double-convex lens L4 is a positive focal length lens, and the first concave-convex lens L1, the double-concave lens L2, the convex-concave lens L3 and the second concave-convex lens L5 are positive focal length lenses with different materials.

2. A five-glued hyper-compact endoscope objective optical system according to claim 1, characterized in that, The lenses used in the five-glued super-thin endoscope objective optical system are all spherical mirrors, and each lens has a matching optical parameter.

3. A five-glued hyper-compact endoscope objective optical system according to claim 1, characterized in that, The optical parameters of the five-glued super-thin endoscope objective optical system satisfy the following conditional expressions: 2.4≤d1 / f≤4.2 0.4≤r 11 / r 52 ≤0.8 9≤f1 / f≤11 1.5≤f2 / f≤3.1 0.4≤d1 / d≤0.8 0.52 < I h f < 1.16 0.5≤L≤1 wherein d1 is the air equivalent length from the object side surface of the five- cemented hyper-slim endoscope objective optical system to the stop surface; f is the focal length of the five-cemented hyper-slim endoscope objective optical system; r 11 is the radius of curvature of the object side surface of the five-cemented hyper-slim endoscope objective optical system; r 52 is the radius of curvature of the image side surface of the five-cemented hyper-slim endoscope objective optical system; f1 is the focal length of the first meniscus lens L1; f2 is the focal length of the double concave lens L2; d1 is the air equivalent length from the image side surface of the first meniscus lens L1 to the stop surface; d is the total length of the five-cemented hyper-slim endoscope objective optical system; L is the working distance of the five-cemented hyper-slim endoscope objective optical system; I h is the image height of the five-cemented hyper-slim endoscope objective optical system; is the optical power of the five-cemented hyper-slim endoscope objective optical system.

4. A five-glued hyper-compact endoscope objective optical system according to claim 1, wherein, The five-glued super-thin endoscope objective optical system is a five-glued rod-shaped lens with a concave-convex structure with a diameter greater than 0.4 mm and less than 0.8 mm.

5. A five-glued hyper-compact endoscope objective optical system according to claim 1, wherein, The total field of view of the five-glued super-thin endoscope objective optical system is 50°.

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