A digital lens optical system
By optimizing the lens design and using a glued lens structure composed of four lenses, the existing digital lens structure is solved, and a simple and efficient digital lens optical system is realized, which improves imaging quality and reduces costs.
Patent Information
- Application Number
- CN202411428623.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-14
- Publication Date
- 2024-12-17
- Estimated Expiration
- 2044-10-14
AI Technical Summary
In order to improve imaging quality, existing digital lenses have complex lens structures and expensive prices, and lack simple and efficient designs.
Four lenses are arranged in sequence along the optical axis direction, including two sets of glued lenses, including double-convex and concave-convex lenses. By optimizing the curvature radius and material selection of the lens, a simple digital lens optical system is realized.
It realizes a digital lens with simple structure and high imaging quality, adapted to the market digital camera, with a focal length of 105mm, a field of view 12°, an aperture number of 6.2, an image surface diameter of 22.4mm, and a distance from the fourth lens to the image surface is 53.291mm, imaging Excellent quality.
Smart Images
Figure CN118962947B_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of digital lens manufacturing, in particular to a digital lens optical system. Background Art
[0002] Digital lenses are important components of digital cameras, and there are many types with different performances. Judging from the digital lenses disassembled on the market, many digital lenses continue to increase the number of lenses in order to improve imaging quality, making the lens structure complex and expensive. Summary of the invention
[0003] The object of the present invention is to provide a digital lens optical system to solve the problems raised in the above background technology.
[0004] In order to solve the above technical problems, the present invention provides the following technical solutions: a digital lens optical system, characterized in that: a first lens, a second lens, a third lens, and a fourth lens are sequentially arranged along the optical axis from the object side to the image side, the first lens and the second lens form a cemented lens, the third lens and the fourth lens form a cemented lens,
[0005] The first lens is a biconvex lens, the second lens is a concave-convex lens with the concave surface facing the object side, the third lens is a concave-convex lens with the convex surface facing the object side, and the fourth lens is a concave-convex lens with the convex surface facing the object side. The optical system only has the above four lenses with optical power.
[0006] As an optimal technical solution, the object side curvature radius of the first lens is 44.36mm, the image side curvature radius is -42.48mm, the center thickness is 4.5mm, the material is glass H-BaK3, and the diameter is 23mm; the object side curvature radius of the second lens is -42.48mm, the image side curvature radius is -287.3mm, the center thickness is 2mm, the material is glass H-ZF2, and the diameter is 23mm; the object side curvature radius of the third lens is 24.79mm, the image side curvature radius is 32.995mm, the center thickness is 3.5mm, the material is glass H-ZLaF3, and the diameter is 23mm; the object side curvature radius of the fourth lens is 32.995mm, the image side curvature radius is 17.54mm, the center thickness is 2mm, the material is glass H-LaF2, the diameter is 23mm, and the distance between the second lens and the third lens is 29.8mm.
[0007] Compared with the prior art, the beneficial effects achieved by the present invention are:
[0008] The digital lens optical system of the present application has a focal length of 105mm, a field of view of 12°, an aperture number of 6.2, an image plane diameter of 22.4mm, and a distance from the fourth lens to the image plane of 53.291mm. The digital lens adopts two groups of cemented lenses, has a simple structure, high imaging quality, and can be adapted to commonly used digital cameras on the market. BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:
[0010] Figure 1 is a schematic diagram of an optical system of the present invention;
[0011] Figure 2 is a field curvature distortion diagram of the present invention;
[0012] Figure 3 is a spot diagram of the present invention;
[0013] Figure 4 is the MTF diagram of the present invention;
[0014] Figure 5 is a color difference diagram of the present invention;
[0015] Figure 6 It is the grid distortion map of the present invention. DETAILED DESCRIPTION
[0016] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0017] As attached Figure 1-6 As shown, the present invention provides the following technical solution: a digital lens optical system, characterized in that: a first lens 1, a second lens 2, a third lens 3, and a fourth lens 4 are sequentially arranged along the optical axis from the object side to the image side, the first lens 1 and the second lens 2 form a cemented lens, the third lens 3 and the fourth lens 4 form a cemented lens,
[0018] The first lens 1 is a biconvex lens, the second lens 2 is a concave-convex lens with its concave surface facing the object side, the third lens 3 is a concave-convex lens with its convex surface facing the object side, and the fourth lens 4 is a concave-convex lens with its convex surface facing the object side. Only the above four lenses have optical power in the optical system.
[0019] As a preferred technical solution, the first lens 1 has an object side curvature radius of 44.36 mm, an image side curvature radius of -42.48 mm, a center thickness of 4.5 mm, and is made of glass H-BaK3 with a diameter of 23 mm; the second lens 2 has an object side curvature radius of -42.48 mm, an image side curvature radius of -287.3 mm, a center thickness of 2 mm, and is made of glass H-ZF2 with a diameter of 23 mm; the third lens 3 has an object side curvature radius of 24.79 mm, an image side curvature radius of 32.995 mm, a center thickness of 3.5 mm, and is made of glass H-ZLaF3 with a diameter of 23 mm; the fourth lens 4 has an object side curvature radius of 32.995 mm, an image side curvature radius of 17.54 mm, a center thickness of 2 mm, and is made of glass H-LaF2 with a diameter of 23 mm, and the distance between the second lens 2 and the third lens 3 is 29.8 mm.
[0020] The digital lens optical system of the present invention has a focal length of 105 mm, a field of view of 12°, an aperture number of 6.2, an image plane diameter of 22.4 mm, and a distance from the fourth lens to the image plane of 53.291 mm.
[0021] Attached Figure 1 This is a schematic diagram of the optical system structure of the present application, which mainly describes the number and structure of lenses in the optical system. Figure 1 It can be learned that the optical system uses two sets of cemented lenses to achieve the performance of a digital lens, and the contour diameters of the two sets of cemented lenses are consistent. In this way, the pressure ring and the spacer ring can be processed using a set of standard processes in the structural design, and the accessories have high universal performance after processing.
[0022] Attached Figure 2 The field curvature distortion diagram of this application is an important tool for analyzing and evaluating the imaging quality of optical systems. It reveals the influence of field curvature and distortion on the imaging effect. It is also called field curvature. It describes that after a plane object passes through a lens system, the clear image point formed is not on a plane, but on a curved surface. Distortion reflects the similarity between the object and the image, including barrel distortion and pincushion distortion. We use the attached Figure 2 It can be seen that the field curvature of the present application is very small, the edges and the center are relatively clear, the image quality is good, the distortion is less than 0.5%, and the human eye cannot observe the deformation of the image after the digital lens is formed; Figure 6 It can be seen intuitively from the grid distortion diagram in that the optical system of the present application has almost no bending or deformation at the center and edge of the image plane.
[0023] Attached Figure 3It is the point diagram of the present application. The distribution of points in the point diagram should be uniform and dense, without obvious abnormal values or outliers. The more evenly distributed the data is, the more stable the imaging quality is. The energy of the optical system point diagram in the present application is relatively concentrated, and the imaging is relatively clear.
[0024] Attached Figure 4 The MTF graph of this application, which is what we often call the modulation transfer function (MTF) curve graph, is of great significance in evaluating the imaging quality of optical systems. The MTF curve graph reflects the optical system's ability to transfer different spatial frequency components, that is, the degree to which the system retains image details and contrast. Through the MTF curve graph, we can intuitively understand the resolution limit of the optical system, the contrast attenuation, and the image quality change trend with spatial frequency. This has important reference value for the design and optimization of optical systems, the evaluation of imaging quality, and the performance comparison between different optical systems. We use Figure 4 It can be seen that the better the resolution of the optical system of this application, the higher the sharpness.
[0025] Attached Figure 5 It is the chromatic aberration diagram of the present application. The chromatic aberration diagram is a visualization tool for displaying the chromatic aberration phenomenon in the imaging of an optical system. It reveals that since the lens has different refractive indices for light of different wavelengths, the multi-color light is separated after passing through the lens and cannot be focused on the same point, thus causing chromatic aberration on the imaging surface. The optical system of the present application has no obvious chromatic aberration under visible light conditions.
[0026] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.
Claims
1. A digital lens optical system, characterized in that: A first lens (1), a second lens (2), a third lens (3), and a fourth lens (4) are arranged in sequence from the object side to the image side along the optical axis. The first lens (1) and the second lens (2) form a cemented lens, and the third lens (3) and the fourth lens (4) form a cemented lens. The first lens (1) is a biconvex lens, the second lens (2) is a concave-convex lens with its concave surface facing the object side, the third lens (3) is a concave-convex lens with its convex surface facing the object side, and the fourth lens (4) is a concave-convex lens with its convex surface facing the object side, and the optical system has only the above four lenses having optical power; The first lens (1) has an object side curvature radius of 44.36 mm, an image side curvature radius of -42.48 mm, a center thickness of 4.5 mm, is made of glass H-BaK3, and has a diameter of 23 mm; the second lens (2) has an object side curvature radius of -42.48 mm, an image side curvature radius of -287.3 mm, a center thickness of 2 mm, is made of glass H-ZF2, and has a diameter of 23 mm; the third lens (3) has an object side curvature radius of 24.79 mm, an image side curvature radius of 32.995 mm, a center thickness of 3.5 mm, is made of glass H-ZLaF3, and has a diameter of 23 mm; the fourth lens (4) has an object side curvature radius of 32.995 mm, an image side curvature radius of 17.54 mm, a center thickness of 2 mm, is made of glass H-LaF2, and has a diameter of 23 mm; and the distance between the second lens (2) and the third lens (3) is 29.8 mm.