Large-aperture telephoto lens optical system
By designing a large aperture telephoto lens optical system using 5 lenses, the problems of high cost and complex structure of existing lenses are solved, and the effects of large aperture, low cost and efficient production are achieved.
Patent Information
- Application Number
- CN202421986173.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-15
- Publication Date
- 2025-05-13
- Estimated Expiration
- 2034-08-15
AI Technical Summary
Most existing photography objectives use high-cost and complex structure lenses, which are difficult to meet the civil market's demand for large aperture, low-cost and efficient production.
A large aperture telephoto lens optical system is designed, adopting a structure of five lenses, including the first positive lens, the second negative lens, the third positive lens, the fourth positive meniscus lens and the fifth negative lens. By optimizing the refractive index and Abbe number, spherical aberration, intelligent difference, astigmatism and chromatic aberration are corrected.
It has achieved good image quality within large aperture F1.0, and is simple in structure and low in cost, which is suitable for mass production.
Smart Images
Figure CN222866947U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of optical systems, and in particular relates to a large aperture telephoto lens optical system. Background Art
[0002] At present, most photographic lenses use the Cooke three-piece structure and its improved structure. Among these structures, most are small and medium aperture lenses. A small number of large aperture lens structures also use more than 6 lenses or aspherical lenses, resulting in high development and post-production costs and difficult to popularize. However, the civilian market has an increasing demand for large aperture lenses with good night vision functions, simple structure, low cost, and mass production. Utility Model Content
[0003] The utility model aims to solve the above technical problems at least to a certain extent. To this end, the utility model aims to provide a large aperture telephoto lens optical system.
[0004] The technical solution adopted by the utility model is:
[0005] A large aperture telephoto lens optical system comprises a first positive lens, a second negative lens, a third positive lens, a fourth positive meniscus lens and a fifth negative lens which are arranged in sequence from the object side to the image side; the refractive index ND of the first positive lens is 1.56-1.66, and the Abbe number VD is 58-65; the refractive index ND of the second negative lens is 1.7-1.83, and the Abbe number VD is 23-33; the refractive index ND of the third positive lens is 1.56-1.66, and the Abbe number VD is 52-59; the refractive index ND of the fourth positive meniscus lens is 1.73-1.83, and the Abbe number VD is 45-52; the refractive index ND of the fifth negative lens is 1.8-1.86, and the Abbe number VD is 22-25.
[0006] Preferably, the radius of curvature of the first surface of the first positive lens is 19-21 mm, and the semi-clear aperture is 10-12 mm; the radius of curvature of the second surface of the first positive lens is -500-500 mm, and the semi-clear aperture is 10-12 mm.
[0007] Preferably, the radius of curvature of the first surface of the second negative lens is -37 to -38 mm, and the semi-clear aperture is 9.5 to 10.5 mm; the radius of curvature of the second surface of the second negative lens is 100 to 500 mm, and the semi-clear aperture is 9.2 to 10.5 mm.
[0008] Preferably, the radius of curvature of the first surface of the third positive lens is 37 to 38.5 mm, and the semi-clear aperture is 8.5 to 9.5 mm; the radius of curvature of the second surface of the third positive lens is -37 to -38.3 mm, and the semi-clear aperture is 8 to 9.5 mm.
[0009] Preferably, the radius of curvature of the first surface of the fourth positive meniscus lens is 14-15.2 mm, and the semi-clear aperture is 7-8.5 mm; the radius of curvature of the second surface of the fourth positive meniscus lens is 53-54.3 mm, and the semi-clear aperture is 6-7.5 mm.
[0010] Preferably, the radius of curvature of the first surface of the fifth negative lens is -53 to -54.2 mm, and the semi-clear aperture is 5.2 to 6.2 mm; the radius of curvature of the second surface of the fifth negative lens is 16 to 17.5 mm, and the semi-clear aperture is 4.2 to 5.5 mm.
[0011] The beneficial effects of the utility model are:
[0012] The utility model provides a large aperture telephoto lens optical system, which uses only 5 lenses and corrects spherical aberration, coma, astigmatism and chromatic aberration, so that it has good image quality within a large aperture of F1.0; at the same time, the optical system structure is simple to assemble, low in cost, and suitable for mass production. BRIEF DESCRIPTION OF THE DRAWINGS
[0013] Figure 1 It is a schematic diagram of the optical system of the large aperture telephoto lens of the utility model.
[0014] Figure 2 It is a parameter diagram of the optical system of the large aperture telephoto lens of the utility model.
[0015] In the figure: 1-first positive lens; 2-second negative lens; 3-third positive lens; 4-fourth positive meniscus lens; 5-fifth negative lens. DETAILED DESCRIPTION
[0016] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention. The components of the embodiments of the present invention generally described and shown in the accompanying drawings herein can be arranged and designed in a variety of different configurations.
[0017] In the present utility model, unless otherwise clearly stipulated and limited, the terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal connection of two elements.
[0018] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.
[0019] like Figure 1 and Figure 2 As shown, a large aperture telephoto lens optical system of the present embodiment is improved on the basis of the Cooke three-piece structure, and achieves a large aperture and a large field of view with the least number of lenses and the simplest structure; specifically, the optical system includes a first positive lens 1, a second negative lens 2, a third positive lens 3, a fourth positive meniscus lens 4 and a fifth negative lens 5, which are arranged in sequence from the object side to the image side; a light beam from the object side passes through the first positive lens 1, the second negative lens 2, the third positive lens 3, the fourth positive meniscus lens 4 and the fifth negative lens 5 in sequence to reach the image side, and an image is formed on the image side. The refractive index ND of the first positive lens 1 is 1.56-1.66, and the Abbe number VD is 58-65; the refractive index ND of the second negative lens 2 is 1.7-1.83, and the Abbe number VD is 23-33; the refractive index ND of the third positive lens 3 is 1.56-1.66, and the Abbe number VD is 52-59; the refractive index ND of the fourth positive meniscus lens 4 is 1.73-1.83, and the Abbe number VD is 45-52; the refractive index ND of the fifth negative lens 5 is 1.8-1.86, and the Abbe number VD is 22-25.
[0020] like Figure 2 As shown, the first surface of the first positive lens 1 is R1, and the second surface is R2; the first surface of the second negative lens 2 is R3, and the second surface is R4; the first surface of the third positive lens 3 is R5, and the second surface is R6; the first surface of the fourth positive meniscus lens 4 is R7, and the second surface is R8; the first surface of the fifth negative lens 5 is R9, and the second surface is R10. D1 is the thickness of the first positive lens 1; D2 is the air gap between the first positive lens 1 and the second negative lens 2; D3 is the thickness of the second negative lens 2; D4 is the air gap between the second negative lens 2 and the third positive lens 3; D5 is the thickness of the third positive lens 3; D6 is the air gap between the third positive lens 3 and the fourth positive meniscus lens 4; D7 is the thickness of the fourth positive meniscus lens 4; D8 is the air gap between the fourth positive meniscus lens 4 and the fifth negative lens 5; D9 is the thickness of the fifth negative lens 5.
[0021] Among them, the radius of curvature of the first surface R1 of the first positive lens 1 is 19 to 21 mm, and the semi-clear aperture is 10 to 12 mm; the radius of curvature of the second surface R2 of the first positive lens 1 is -500 to 500 mm, and the semi-clear aperture is 10 to 12 mm. The radius of curvature of the first surface R3 of the second negative lens 2 is -37 to -38 mm, and the semi-clear aperture is 9.5 to 10.5 mm; the radius of curvature of the second surface R4 of the second negative lens 2 is 100 to 500 mm, and the semi-clear aperture is 9.2 to 10.5 mm. The radius of curvature of the first surface R5 of the third positive lens 3 is 37 to 38.5 mm, and the semi-clear aperture is 8.5 to 9.5 mm; the radius of curvature of the second surface R6 of the third positive lens 3 is -37 to -38.3 mm, and the semi-clear aperture is 8 to 9.5 mm. The first surface R7 of the fourth positive meniscus lens 4 has a curvature radius of 14 to 15.2 mm, and a semi-clear aperture of 7 to 8.5 mm; the second surface R8 of the fourth positive meniscus lens 4 has a curvature radius of 53 to 54.3 mm, and a semi-clear aperture of 6 to 7.5 mm. The first surface R9 of the fifth negative lens 5 has a curvature radius of -53 to -54.2 mm, and a semi-clear aperture of 5.2 to 6.2 mm; the second surface R10 of the fifth negative lens 5 has a curvature radius of 16 to 17.5 mm, and a semi-clear aperture of 4.2 to 5.5 mm.
[0022] More parameters of each lens are shown in Table 1.
[0023] Table 1 Lens parameters
[0024]
[0025]
[0026] The design parameters of the large aperture telephoto lens optical system are as follows: focal length 25mm, FNO: 1.0~8, diffuse spot diameter less than 5um, maximum imaging chip 1 / 1.8, relative light transmission greater than 88%, uniform image quality. It has a wide spectral range of 400nm~1100nm, and has good imaging effects both day and night; the effective aperture reaches F1.0~F8; when the light is insufficient at night, it has good and clear imaging at an object distance of 0.5m~infinity.
[0027] The present utility model is not limited to the above-mentioned optional implementation modes. Anyone can derive other various forms of products under the inspiration of the present utility model. However, no matter what changes are made in the shape or structure, all technical solutions that fall within the scope defined by the claims of the present utility model fall within the protection scope of the present utility model.
Claims
1. A large aperture telephoto lens optical system, characterized in that: The invention comprises a first positive lens (1), a second negative lens (2), a third positive lens (3), a fourth positive meniscus lens (4) and a fifth negative lens (5) which are arranged in sequence from the object side to the image side; the refractive index ND of the first positive lens (1) is 1.56-1.66, and the Abbe number VD is 58-65; the refractive index ND of the second negative lens (2) is 1.7-1.83, and the Abbe number VD is 23-33; the refractive index ND of the third positive lens (3) is 1.56-1.66, and the Abbe number VD is 52-59; the refractive index ND of the fourth positive meniscus lens (4) is 1.73-1.83, and the Abbe number VD is 45-52; the refractive index ND of the fifth negative lens (5) is 1.8-1.86, and the Abbe number VD is 22-25.
2. The large aperture telephoto lens optical system according to claim 1, characterized in that: The first surface of the first positive lens (1) has a curvature radius of 19 to 21 mm, and a semi-clear aperture of 10 to 12 mm; the second surface of the first positive lens (1) has a curvature radius of -500 to 500 mm, and a semi-clear aperture of 10 to 12 mm.
3. The large aperture telephoto lens optical system according to claim 1, characterized in that: The first surface of the second negative lens (2) has a curvature radius of -37 to -38 mm, and a semi-clear aperture of 9.5 to 10.5 mm; the second surface of the second negative lens (2) has a curvature radius of 100 to 500 mm, and a semi-clear aperture of 9.2 to 10.5 mm.
4. The large aperture telephoto lens optical system according to claim 1, characterized in that: The first surface of the third positive lens (3) has a curvature radius of 37 to 38.5 mm, and a semi-clear aperture of 8.5 to 9.5 mm; the second surface of the third positive lens (3) has a curvature radius of -37 to -38.3 mm, and a semi-clear aperture of 8 to 9.5 mm.
5. The large aperture telephoto lens optical system according to claim 1, characterized in that: The first surface of the fourth positive meniscus lens (4) has a curvature radius of 14 to 15.2 mm, and a semi-clear aperture of 7 to 8.5 mm; the second surface of the fourth positive meniscus lens (4) has a curvature radius of 53 to 54.3 mm, and a semi-clear aperture of 6 to 7.5 mm.
6. The large aperture telephoto lens optical system according to claim 1, characterized in that: The first surface of the fifth negative lens (5) has a curvature radius of -53 to -54.2 mm, and a semi-clear aperture of 5.2 to 6.2 mm; the second surface of the fifth negative lens (5) has a curvature radius of 16 to 17.5 mm, and a semi-clear aperture of 4.2 to 5.5 mm.