Two-component endoscope objective lens optical system
The endoscopic objective lens optical system, designed with two components as a whole, solves the assembly problem of small-diameter endoscopes, achieving a compact structure and efficient assembly and adjustment, improving imaging quality and production efficiency, and reducing costs.
Patent Information
- Application Number
- CN202520565283.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-28
- Publication Date
- 2026-02-10
- Estimated Expiration
- 2035-03-28
AI Technical Summary
Existing small-diameter endoscopes suffer from inconvenient installation and difficult adjustment during assembly, resulting in limited imaging quality, low production efficiency, and high requirements for worker skill.
The endoscope objective optical system adopts a two-component integrated design, including a first lens, a second lens, a third lens group, a fourth lens, a fifth lens, a sixth lens, and a seventh lens. The aperture is set by bonding and coating, which simplifies the assembly process. It also uses sapphire protective glass and lens combinations with different refractive indices to meet specific optical parameters.
A compact objective lens structure was achieved, which facilitates manual assembly, improves imaging quality and production efficiency, and reduces processing costs.
Smart Images
Figure CN223897714U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application belongs to the technical field of endoscopes, and particularly relates to a two-component endoscope objective optical system. BACKGROUND
[0002] With the continuous development of medical technology, endoscopes, as an important tool widely used in diagnosis and treatment, have become an indispensable part of modern medicine. The working principle of endoscopes relies on their lens systems, that is, through the lens to obtain the image of the examined area and transmit it to medical personnel.
[0003] There are several common problems in the existing endoscope assembly process:
[0004] 1. In the existing assembly and adjustment process of 1.5mm-3.00mm small caliber endoscopes, due to the special structure and angle requirements of the image conversion prism, it is not convenient to install, and it is difficult to adjust after installation. These problems of the existing endoscope image conversion structure lead to an increase in overall processing cost, and the imaging quality of the endoscope is limited.
[0005] 2. In the common endoscope objective assembly and adjustment process, the diaphragm, image conversion prism and lens group are constantly adjusted, resulting in low production efficiency and high skill requirement for workers in the assembly process. SUMMARY
[0006] In order to solve the above problems existing in the prior art, the utility model provides a two-component endoscope objective optical system, adopts the overall design of two components, so that the objective lens structure is more compact, and at the same time, the whole lens group gets good imaging effect, which is convenient for manual assembly and adjustment.
[0007] The purpose of the utility model is realized through the following technical scheme:
[0008] A two-component endoscope objective optical system, comprising a first lens, a second lens, a third lens group, a fourth lens, a fifth lens, a sixth lens and a seventh lens arranged in order from the object side to the imaging side; the first lens, the second lens, the third lens group and the fourth lens are glued in order to form a first component, and a diaphragm is arranged behind the third lens group by coating; the fifth lens, the sixth lens and the seventh lens are glued in order to form a second component.
[0009] Further, the first lens is a protective glass without optical power; the second lens has negative optical power; the third lens group is an image conversion prism group without optical power; the fourth lens has negative optical power; the fifth lens has positive optical power; the sixth lens has positive optical power; and the seventh lens has positive optical power.
[0010] Further, the third lens group is composed of a first glass spacer, a view angle prism and a second glass spacer in sequence, and the first glass spacer, the view angle prism and the second glass spacer are made of the same material.
[0011] Preferably, the view angle prism of the third lens group is a reflective 30° view angle prism, and the diaphragm is arranged at the tail of the reflective 30° view angle prism by coating.
[0012] Preferably, the view angle prism of the third lens group is a reflective 12° view angle prism, and the diaphragm is arranged at the tail of the second glass spacer by coating.
[0013] Preferably, the view angle prism of the third lens group is a reflective 45° view angle prism, and the diaphragm is arranged at the tail of the second glass spacer by coating.
[0014] Further, the two-group endoscope objective optical system further comprises a spacer ring arranged between the fourth lens and the fifth lens.
[0015] Further, the endoscope objective optical system satisfies the following conditions:
[0016] Ih / f>1.27
[0017] 8.2<D / f<9
[0018] 1.5mm<Φ<2mm
[0019] wherein Ih is the maximum image height of the endoscope objective optical system, f is the overall focal length of the endoscope objective optical system, D is the entrance pupil diameter of the endoscope objective optical system, and Φ is the maximum full aperture of the lens of the endoscope objective optical system.
[0020] Further, the refractive index of the first lens is 1.7<Nd1<1.8 and the Abbe number is 60<Vd1<80; the refractive index of the second lens is 1.8<Nd2<1.9 and the Abbe number is 30<Vd2<40; the refractive index of the third lens is 1.7<Nd3<1.8 and the Abbe number is 20<Vd3<30; the refractive index of the fourth lens is 1.7<Nd4<1.8 and the Abbe number is 20<Vd4<30; the refractive index of the fifth lens is 1.8<Nd5<1.9 and the Abbe number is 20<Vd5<30; the refractive index of the sixth lens is 1.5<Nd6<1.6 and the Abbe number is 60<Vd6<70; and the refractive index of the seventh lens is 1.5<Nd7<1.6 and the Abbe number is 50<Vd2<60.
[0021] Further, the focal length f of the endoscope objective optical system is 0.78mm, the total optical length TTL is less than or equal to 12.2mm, the maximum optical aperture D is less than or equal to 1.8mm, and the full field angle 2ω is less than or equal to 80°.
[0022] The utility model has the following beneficial effects:
[0023] The utility model discloses a two-group-element endoscope objective optical system, the diaphragm is arranged behind the third lens group through the coating mode, reduces the process of manual installation and adjustment diaphragm, first lens, second lens, third lens, diaphragm, fourth lens are glued in proper order and constitute first group element, fifth lens, sixth lens and seventh lens are glued in proper order and constitute second group element, make the objective lens structure more compact.The first lens is sapphire protection glass, the second lens is concave lens, the fourth lens is convex lens, the fifth lens is concave lens, the sixth lens is convex lens, the seventh lens is convex lens combination the lens group of endoscope objective, make the whole lens group get good imaging effect, and convenient manual assembly simultaneously.The focal length f of the utility model is 0.7~1.0mm, the total optical length TTL is less than or equal to 12.2mm, the maximum optical aperture D is less than or equal to 2mm, and the full field angle 2ω is less than or equal to 80°. BRIEF DESCRIPTION OF DRAWINGS
[0024] Figure 1 It is a kind of two-group-element endoscope objective optical system's structure schematic diagram for the utility model embodiment 1;
[0025] Figure 2 It is the structure schematic diagram of the turning image prism group for the two-group-element endoscope objective optical system of the utility model embodiment 1;
[0026] Figure 3 It is the MTF curve diagram under visible light for the two-group-element endoscope objective optical system of the utility model embodiment 1;
[0027] Figure 4 It is the field curvature diagram and distortion diagram under visible light for the two-group-element endoscope objective optical system of the utility model embodiment 1;
[0028] Figure 5 It is the vertical axis chromatic aberration diagram for the two-group-element endoscope objective optical system of the utility model embodiment 1;
[0029] Figure 6 It is a kind of two-group-element endoscope objective optical system's structure schematic diagram for the utility model embodiment 2;
[0030] Figure 7 It is the structure schematic diagram of the turning image prism group for the two-group-element endoscope objective optical system of the utility model embodiment 2;
[0031] Figure 8 This is a schematic diagram of the structure of a two-element endoscope objective optical system according to Embodiment 3 of this utility model;
[0032] Figure 9 This is a schematic diagram of the image-rotating prism group structure of a two-element endoscope objective lens optical system according to Embodiment 3 of this utility model;
[0033] In the picture:
[0034] 100 - First lens; 200 - Second lens; 300 - Third lens group; 400 - Aperture stop; 500 - Fourth lens; 600 - Fifth lens; 700 - Sixth lens; 800 - Seventh lens; 900 - Spacer; 301 - Glass gasket No. 1; 302 - Image-rotating prism; 303 - Glass gasket No. 2. Detailed Implementation
[0035] The embodiments of this utility model are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.
[0036] Example 1
[0037] like Figure 1 As shown, this embodiment is a two-element endoscope objective lens optical system, including a first lens 100, a second lens 200, a third lens group 300, a fourth lens 400, a fifth lens 600, a sixth lens 700, and a seventh lens 800 arranged sequentially from the object side to the imaging side; wherein, the first lens 100, the second lens 200, the third lens group 300, and the fourth lens 400 are cemented together to form the first element, and an aperture 400 is provided behind the third lens group 300 by means of coating, and the aperture 400 is cemented together with the fourth lens 400; the fifth lens 600, the sixth lens 700, and the seventh lens 800 are cemented together to form the second element.
[0038] Furthermore, the first lens 100 is protective glass and has no optical power; the second lens 200 has negative optical power; the third lens group is an image-rotating prism group and has no optical power; the fourth lens 400 has negative optical power; the fifth lens 600 has positive optical power; the sixth lens 700 has positive optical power; and the seventh lens 800 has positive optical power.
[0039] Furthermore, the third lens group 300 is composed of a first glass gasket 301, a viewing prism 302, and a second glass gasket 303 bonded together in sequence, and the first glass gasket 301, the image-rotating prism 302, and the second glass gasket 303 are made of the same material.
[0040] As preferred, as shown in the embodiment, the third lens group 300 adopts a reflective 30° view angle prism, and the diaphragm 400 is arranged at the tail of the reflective 30° view angle prism by coating. Figure 2
[0041] Further, a spacer 900 is arranged between the fourth lens 500 and the fifth lens 600, so as to facilitate compensation of the overall aberration of the objective optical system.
[0042] Further, the endoscope objective optical system satisfies the following conditions:
[0043] Ih / f>1.27
[0044] 8.2<D / f<9
[0045] 1.5mm<Φ<2mm
[0046] wherein Ih is the maximum image height of the endoscope objective optical system, f is the overall focal length of the endoscope objective optical system, D is the entrance pupil diameter of the endoscope objective optical system, and Φ is the maximum full aperture of the lens of the endoscope objective optical system.
[0047] Further, the first lens 100, the second lens 200, the fourth lens 400, the fifth lens 600, the sixth lens 700 and the seventh lens 800 are all glass spherical lenses. It can be understood that the glass spherical lens refers to a lens that is transparent and has a spherical concave or convex part, regardless of whether it is a concave lens or a convex lens.
[0048] Further, the first lens 100 is a sapphire protective glass.
[0049] Further, the refractive index of the first lens 100 is 1.7<Nd1<1.8, and the Abbe number is 60<Vd1<80; the refractive index of the second lens 200 is 1.8<Nd2<1.9, and the Abbe number is 30<Vd2<40; the refractive index of the third lens 300 is 1.7<Nd3<1.8, and the Abbe number is 20<Vd3<30; the refractive index of the fourth lens 400 is 1.7<Nd4<1.8, and the Abbe number is 20<Vd4<30; the refractive index of the fifth lens 600 is 1.8<Nd5<1.9, and the Abbe number is 20<Vd5<30; the refractive index of the sixth lens 700 is 1.5<Nd6<1.6, and the Abbe number is 60<Vd6<70; and the refractive index of the seventh lens 800 is 1.5<Nd7<1.6, and the Abbe number is 50<Vd2<60.
[0050] Furthermore, the focal length f of the endoscope objective is 0.78 mm, the total optical length TTL≤12.2 mm, the maximum optical aperture D≤1.8 mm, and the full field of view 2ω≤80°.
[0051] like Figure 3 The image shows the MTF curve of the objective lens under visible light. As can be seen from the graph, at a spatial frequency of 125 lp / mm, the MTF value across the entire field of view is greater than 0.20, indicating excellent image quality and therefore high objective lens resolution. Figure 4 The image shows the field curvature and distortion of the objective lens under visible light. It can be seen from the image that both the meridional and sagittal field curvatures are less than 0.1 mm, and the full field-of-view distortion is less than 23%, indicating excellent image quality. Figure 5 The figure shows the chromatic aberration curve of the objective lens under visible light. As can be seen from the figure, the chromatic aberration at all magnifications is less than 2 μm, indicating small chromatic aberration and high image color reproduction.
[0052] The optical parameters of the endoscope objective optical system described in this embodiment are shown in Table 1:
[0053] Table 1 Optical parameters of the endoscope objective lens optical system described in Example 1
[0054] Type Surface Radius of curvature Thickness Refractive index Nd Abbe number Vd Object plane 0 Infinity 10.00 Standard plane 1 Infinity 0.40 1.77 72.3 Standard plane 2 Infinity 0.00 Standard plane 3 Infinity 0.42 1.88 39.2 Standard plane 4 0.54 0.11 Standard plane 5 Infinity 3.00 1.76 27.5 Standard plane 6 Infinity 0.00 Stop STO 7 Infinity 0.78 1.76 27.5 Standard plane 8 -1.89 0.86 Standard plane 9 9.19 0.71 1.85 23.8 Standard plane 10 1.12 1.14 1.51 60.6 Standard plane 11 2.22 0.80 1.57 56.1 Standard plane 12 -1.59 3.9
[0055] In Table 1, surfaces 1, 3, 5, 7, 9, 10, and 11 correspond to the first lens 100, the second lens 200, the steering prism 300, the third lens 400, the fourth lens 500, the fifth lens 600, the sixth lens 700, and the seventh lens 800, respectively.
[0056] Example 2
[0057] like Figure 6 As shown, this embodiment is a two-element endoscope objective optical system, whose structure is basically the same as that of Embodiment 1, except that:
[0058] like Figure 7 As shown, in this embodiment, the image-rotating prism 302 of the third lens group 300 is a reflective 12° viewing prism. In order to make the optical path from different viewing prisms to the aperture stop the same, the aperture stop 400 is set at the tail of the second glass pad 303 by coating to act as an aperture stop.
[0059] Example 3
[0060] like Figure 8 As shown, this embodiment is a two-element endoscope objective optical system, whose structure is basically the same as that of Embodiment 1, except that:
[0061] like Figure 9As shown, in this embodiment, the image-rotating prism 302 of the third lens group 300 is a reflective 45° viewing prism. In order to make the optical path from different viewing prisms to the aperture stop the same, the aperture stop 400 is set at the tail of the second glass pad 303 by coating to act as an aperture stop.
[0062] The above detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.
[0063] It should be noted that similar labels and letters in the accompanying drawings indicate similar items. Therefore, once an item is defined in one accompanying drawing, it does not need to be further defined and explained in subsequent accompanying drawings.
[0064] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.
Claims
1. A two-element endoscope objective lens optical system, characterized in that, It includes a first lens, a second lens, a third lens group, a fourth lens, a fifth lens, a sixth lens, and a seventh lens arranged in sequence from the object side to the imaging side; the first lens, the second lens, the third lens group, and the fourth lens are sequentially cemented to form a first component, and a diaphragm is arranged behind the third lens group by means of coating; the fifth lens, the sixth lens, and the seventh lens are sequentially cemented to form a second component.
2. The binary endoscopic objective lens optical system as described in claim 1, characterized in that, The first lens is a protective glass and has no optical power; the second lens has a negative optical power; the third lens group is an image rotation prism group and has no optical power; the fourth lens has a negative optical power; the fifth lens has a positive optical power; the sixth lens has a positive optical power; the seventh lens has a positive optical power.
3. The binary endoscopic objective lens optical system as described in claim 1, characterized in that, The third lens group is sequentially cemented by a first glass spacer, an image rotation prism, and a second glass spacer, and the first glass spacer, the image rotation prism, and the second glass spacer are made of the same material.
4. The binary endoscopic objective lens optical system as described in claim 3, characterized in that, The image rotation prism of the third lens group uses a reflective 30° image rotation prism, and the diaphragm is arranged at the tail of the reflective 30° image rotation prism by means of coating.
5. The binary endoscopic objective lens optical system as described in claim 3, characterized in that, The image rotation prism of the third lens group uses a reflective 12° image rotation prism, and the diaphragm is arranged at the tail of the second glass spacer by means of coating.
6. The binary endoscopic objective lens optical system as described in claim 3, characterized in that, The image rotation prism of the third lens group uses a reflective 45° image rotation prism, and the diaphragm is arranged at the tail of the second glass spacer by means of coating.
7. The binary endoscopic objective lens optical system as described in claim 1, characterized in that, It further includes a spacer ring, and the spacer ring is arranged between the fourth lens and the fifth lens.
8. The binary endoscopic objective lens optical system as described in claim 1, characterized in that, The endoscope objective optical system satisfies the following conditions: Ih / f > 1.27 8.2 < D / f < 9 1.5mm < Φ < 2mm Where, Ih is the maximum image height of the endoscope objective optical system, f is the overall focal length of the endoscope objective optical system, D is the entrance pupil diameter of the endoscope objective optical system, and Φ is the maximum full aperture of the lens of the endoscope objective optical system.
9. The binary endoscopic objective lens optical system as described in claim 1, characterized in that, The refractive index of the first lens is such that 1.7 < Nd1 < 1.8, and the Abbe number is such that 60 < Vd1 < 80; the refractive index of the second lens is such that 1.8 < Nd2 < 1.9, and the Abbe number is such that 30 < Vd2 < 40; the refractive index of the third lens is such that 1.7 < Nd3 < 1.8, and the Abbe number is such that 20 < Vd3 < 30; the refractive index of the fourth lens is such that 1.7 < Nd4 < 1.8, and the Abbe number is such that 20 < Vd4 < 30; the refractive index of the fifth lens is such that 1.8 < Nd5 < 1.9, and the Abbe number is such that 20 < Vd5 < 30; the refractive index of the sixth lens is such that 1.5 < Nd6 < 1.6, and the Abbe number is such that 60 < Vd6 < 70; the refractive index of the seventh lens is such that 1.5 < Nd7 < 1.6, and the Abbe number is such that 50 < Vd2 < 60.
10. The binary endoscopic objective lens optical system as described in claim 1, characterized in that, The focal length f of the endoscope objective optical system is 0.78mm, the overall optical length TTL ≤ 12.2mm, the maximum optical aperture D ≤ 1.8mm, and the full field angle 2ω ≤ 80°.