Ultra-wide-angle lens optical system
By improving the Cooke three-piece structure into an ultra-wide-angle lens with a four-lens design, the problems of complex structure and high cost of existing wide-angle lenses are solved, and an optical system with a large field of view and high imaging quality is realized, which is suitable for sports cameras, drones, and vehicle-mounted imaging.
Patent Information
- Application Number
- CN202423074615.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-11
- Publication Date
- 2025-09-30
- Estimated Expiration
- 2034-12-11
AI Technical Summary
Existing wide-angle lenses have complex structures, high costs, are difficult to mass-produce, and have insufficient imaging quality.
It adopts a 4-lens design based on the Cooke three-lens structure, including a combination of negative lens, positive lens and negative lens, uses high refractive index and high Abbe number lenses, aspherical design, the center points of the lenses are on the same line, the material is plastic, and the structure is simplified to achieve ultra-wide angle and large field of view.
It achieves excellent imaging quality with ultra-wide angle and large field of view, simple lens structure, low cost, easy large-scale production, excellent imaging quality and large image surface size, with the maximum photosensitive surface reaching 1/2.8 inches.
Smart Images
Figure CN223401096U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of optical lenses, and in particular relates to an ultra-wide-angle lens optical system. Background Art
[0002] Because wide-angle lenses offer a wide shooting range and the ability to capture more content, they are suitable for applications with specific imaging requirements, such as sports cameras, drones, in-vehicle imaging, and video conferencing equipment. As demand for wide-angle lenses in these areas continues to increase, so too are the requirements for their imaging quality.
[0003] Currently, most photographic lenses use the Cooke three-element structure or its improved version. Even the 170-degree ultra-wide-angle improved version uses more than six elements, resulting in a complex structure, high cost, and difficulty in mass production. Therefore, reducing costs and enabling mass production are particularly important. Utility Model Content
[0004] The purpose of the utility model is to provide an ultra-wide-angle lens optical system. The utility model is improved on the basis of the Cooke three-piece structure, and achieves an optical system with ultra-wide angle, large field of view and excellent imaging quality with the least number of lenses and the simplest structure.
[0005] The purpose of the utility model is achieved by providing an ultra-wide-angle lens optical system, comprising a first lens, a second lens, a third lens, and a fourth lens arranged in sequence along an optical axis from the object side to the image side;
[0006] The first lens is a negative lens, the object side surface of which is convex and the image side surface of which is concave;
[0007] The second lens is a positive lens, with a convex object-side surface and a convex image-side surface;
[0008] The third lens is a positive lens, with a convex object-side surface and a convex image-side surface;
[0009] The fourth lens is a negative lens, the object side surface of which is concave and the image side surface of which is convex; and
[0010] The first lens, the second lens and the third lens are arranged in sequence and spaced apart, and the third lens is arranged in close contact with the fourth lens.
[0011] Furthermore, the curvature radius R1 of the object side surface of the first lens satisfies: 20 mm < R1 < 50 mm;
[0012] The curvature radius R2 of the image-side surface of the first lens satisfies: 2.2 mm < R2 < 2.5 mm;
[0013] The curvature radius R3 of the object side surface of the second lens satisfies: 8.5mm<R3<9.8mm;
[0014] The curvature radius R4 of the image side surface of the second lens satisfies: -5.2mm<R4<-6.5mm;
[0015] The curvature radius R5 of the object side surface of the third lens satisfies: 6.3mm<R5<7.8mm;
[0016] The curvature radius R6 of the image side surface of the third lens satisfies: -3.6mm<R6<-2.8mm;
[0017] The curvature radius R7 of the image-side surface of the fourth lens satisfies: -36 mm<R8<-25 mm.
[0018] Furthermore, the first lens, the second lens, the third lens and the fourth lens are all high-refractive-index and high-Abbe-number lenses.
[0019] Furthermore, the semi-clear aperture r1 of the object-side surface of the first lens satisfies: 7 mm < r1 < 11 mm;
[0020] The semi-clear aperture r2 of the image-side surface of the first lens satisfies the following conditions: 2.1 mm < r2 < 2.4 mm;
[0021] The semi-clear aperture r3 of the object-side surface of the second lens satisfies: 2.2 mm < r3 < 2.4 mm;
[0022] The semi-clear aperture r4 of the image-side surface of the second lens satisfies the following conditions: 2.9 mm < r4 < 3.3 mm;
[0023] The semi-clear aperture r5 on the object side of the third lens satisfies: 3.2 mm < r5 < 4 mm;
[0024] The semi-clear aperture r6 of the image-side surface of the third lens satisfies the following conditions: 3 mm < r6 < 4.2 mm;
[0025] The semi-clear aperture r7 of the object-side surface of the fourth lens satisfies the following conditions: 3.4 mm < r7 < 5 mm;
[0026] The semi-clear aperture r8 of the image-side surface of the fourth lens satisfies: 5mm<r8<6mm.
[0027] Furthermore, the first lens, the second lens, the third lens and the fourth lens are all aspherical lenses.
[0028] Furthermore, center points of the first lens, the second lens, the third lens, and the fourth lens are all on the same straight line.
[0029] Furthermore, the thickness D1 of the first lens satisfies: 0.4 mm < D1 < 0.6 mm;
[0030] The thickness D3 of the second lens satisfies: 4.2 mm < D3 < 5.5 mm;
[0031] The thickness D5 of the third lens satisfies: 1.3 mm < D5 < 2.2 mm;
[0032] The thickness D6 of the fourth lens satisfies: 0.4 mm<D6<0.7 mm.
[0033] Furthermore, the first lens, the second lens, the third lens and the fourth lens are all made of plastic.
[0034] The beneficial effects of the present invention are as follows:
[0035] By sequentially arranging a first lens as a negative lens, a second lens as a positive lens, a third lens as a positive lens, and a fourth lens as a negative lens in the direction of the optical axis, an optical system with ultra-wide angle, large field of view, and excellent imaging quality can be achieved with the simplest structure. Specifically, the optical lens has a simple structure and uses only four lenses to correct spherical aberration, coma, astigmatism, and chromatic aberration. It has good image quality within +-85 degrees and a large image plane size, with a maximum photosensitive surface of 1 / 2.8 inches. The lens structure is short, with a total optical length of 17.3 mm. The system is simple to process and assemble, and can be processed using ordinary large-scale production technology. BRIEF DESCRIPTION OF THE DRAWINGS
[0036] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly describes the drawings required for the specific embodiments or the description of the prior art. Similar elements or parts are generally identified by similar reference numerals throughout the drawings. Elements or parts in the drawings are not necessarily drawn to scale.
[0037] Figure 1 This is a structural diagram of the optical system of the utility model;
[0038] Figure 2 This is the mtf diagram of the lens of the utility model;
[0039] Figure 3 This is the lens point array of the utility model;
[0040] Figure 4 This is the light aberration diagram of the lens of the utility model;
[0041] Figure 5 The field curvature and distortion of the lens of this utility model;
[0042] Figure 6This is the relative illumination diagram of the lens of this utility model.
[0043] In the accompanying drawings, 1 is the first lens, 2 is the second lens, 3 is the third lens, and 4 is the fourth lens. DETAILED DESCRIPTION
[0044] The following embodiments of the technical solution of the present invention are described in detail with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention and are therefore only examples and are not intended to limit the scope of protection of the present invention.
[0045] It should be noted that, unless otherwise specified, the technical terms or scientific terms used in this application should have the common meanings understood by those skilled in the art to which this utility model belongs.
[0046] Reference Figures 1-6 An ultra-wide-angle lens optical system, characterized by comprising a first lens 1, a second lens 2, a third lens 3 and a fourth lens 4 arranged in sequence along the optical axis from the object side to the image side;
[0047] The first lens 1 is a negative lens, the object side surface of which is convex and the image side surface is concave;
[0048] The second lens 2 is a positive lens, the object side surface of which is convex, and the image side surface of which is convex;
[0049] The third lens 3 is a positive lens, with a convex object-side surface and a convex image-side surface;
[0050] The fourth lens 4 is a negative lens, the object side surface of which is concave and the image side surface of which is convex; and
[0051] The first lens 1 , the second lens 2 , and the third lens 3 are sequentially spaced apart, and the third lens 3 and the fourth lens 4 are closely attached.
[0052] By setting the first lens 1, the second lens 2, the third lens 3 and the fourth lens 4 in this technical solution, an effective field of view angle of +-85 degrees can be achieved, and the imaging band is 450-650nm, which can be up to 950nm for special use requirements.
[0053] Preferably, the curvature radius R1 of the object side surface of the first lens 1 satisfies: 20 mm < R1 < 50 mm;
[0054] The curvature radius R2 of the image side surface of the first lens 1 satisfies: 2.2 mm < R2 < 2.5 mm;
[0055] The curvature radius R3 of the object side surface of the second lens 2 satisfies: 8.5 mm < R3 < 9.8 mm;
[0056] The curvature radius R4 of the image side surface of the second lens 2 satisfies: -5.2 mm < R4 < -6.5 mm;
[0057] The curvature radius R5 of the object side surface of the third lens 3 satisfies: 6.3 mm < R5 < 7.8 mm;
[0058] The curvature radius R6 of the image side surface of the third lens 3 satisfies: -3.6 mm < R6 < -2.8 mm;
[0059] It can be understood that since the third lens 3 and the fourth lens 4 are set closely together, the semi-clear aperture R6 on the object side of the fourth lens 4 is equal to the semi-clear aperture R6 on the image side of the third lens 3.
[0060] The curvature radius R7 of the image-side surface of the fourth lens 4 satisfies: -36 mm < R8 < -25 mm.
[0061] Through the technical solution provided in this application, an optical system with ultra-wide angle, large field of view and excellent imaging quality can be achieved with the minimum number of lenses and the simplest structure.
[0062] The optical system diagram of this system is as follows Figure 1 As shown, the light beam from the object side passes through the first negative lens, the second positive lens, the third positive lens, and the fourth negative lens in sequence, reaches the image side, and forms an image on the image side.
[0063] Preferably, the first lens, the second lens, the third lens and the fourth lens are all high-refractive-index and high-Abbe-number lenses.
[0064] Preferably, the semi-clear aperture r1 on the object side of the first lens 1 satisfies: 7mm<r1<11mm;
[0065] The semi-clear aperture r2 of the image-side surface of the first lens 1 satisfies the following conditions: 2.1 mm < r2 < 2.4 mm;
[0066] The semi-clear aperture r3 of the object-side surface of the second lens 2 satisfies the following conditions: 2.2 mm < r3 < 2.4 mm;
[0067] The semi-clear aperture r4 of the image-side surface of the second lens 2 satisfies the following conditions: 2.9 mm < r4 < 3.3 mm;
[0068] The semi-clear aperture r5 of the object-side surface of the third lens 3 satisfies the following conditions: 3.2 mm < r5 < 4 mm;
[0069] The semi-clear aperture r6 of the image-side surface of the third lens 3 satisfies the following conditions: 3 mm < r6 < 4.2 mm;
[0070] The semi-clear aperture r7 of the object-side surface of the fourth lens 4 satisfies the following conditions: 3.4 mm < r7 < 5 mm;
[0071] The semi-clear aperture r8 of the image-side surface of the fourth lens 4 satisfies: 5 mm < r8 < 6 mm.
[0072] Preferably, the first lens 1 , the second lens 2 , the third lens 3 and the fourth lens 4 are all aspherical lenses.
[0073] Preferably, the centers of the first lens 1, the second lens 2, the third lens 3 and the fourth lens 4 are all on the same straight line.
[0074] Preferably, the thickness D1 of the first lens 1 satisfies: 0.4 mm < D1 < 0.6 mm;
[0075] The thickness D3 of the second lens 2 satisfies: 4.2 mm < D3 < 5.5 mm;
[0076] The thickness D5 of the third lens 3 satisfies: 1.3 mm < D5 < 2.2 mm;
[0077] The thickness D6 of the fourth lens 4 satisfies: 0.4 mm<D6<0.7 mm.
[0078] Preferably, the first lens 1 , the second lens 2 , the third lens 3 and the fourth lens 4 are all made of plastic.
[0079] The relevant parameters of each lens in the ultra-wide-angle lens optical system provided by the present invention are shown in the following table:
[0080]
[0081] Figure 1 In the figure, D1 is the thickness of the first lens 1, D2 is the air gap between the first lens 1 and the second lens 2, D3 is the thickness of the second lens 2, D4 is the air gap between the second lens 3 and the third lens 3, D5 is the thickness of the third lens 3, and D6 is the thickness of the fourth lens 4.
[0082] As a preferred embodiment of this invention, the optional optical system design parameters are as follows:
[0083] The field of view is 170 degrees, FNO: 2.6, the diffuse spot diameter is less than 4um, the relative transmittance is greater than 50%, and the image quality is uniform.
[0084] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and description of the present invention.
Claims
1. An ultra-wide-angle lens optical system, characterized in that: It comprises a first lens (1), a second lens (2), a third lens (3) and a fourth lens (4) which are sequentially arranged along the optical axis from the object side to the image side; The first lens (1) is a negative lens, the object side surface of which is convex and the image side surface of which is concave; The second lens (2) is a positive lens, the object side surface of which is convex, and the image side surface of which is convex; The third lens (3) is a positive lens, the object side surface of which is convex, and the image side surface of which is convex; The fourth lens (4) is a negative lens, the object side surface of which is concave and the image side surface of which is convex; and The first lens (1), the second lens (2) and the third lens (3) are arranged in sequence and spaced apart, and the third lens (3) and the fourth lens (4) are arranged in close contact.
2. The ultra-wide-angle lens optical system according to claim 1, wherein: The curvature radius R1 of the object side surface of the first lens (1) satisfies: 20 mm < R1 < 50 mm; The curvature radius R2 of the image side surface of the first lens (1) satisfies: 2.2 mm < R2 < 2.5 mm; The curvature radius R3 of the object side surface of the second lens (2) satisfies: 8.5mm<R3<9.8mm; The curvature radius R4 of the image side surface of the second lens (2) satisfies: -5.2mm<R4<-6.5mm; The curvature radius R5 of the object side surface of the third lens (3) satisfies: 6.3mm<R5<7.8mm; The curvature radius R6 of the image side surface of the third lens (3) satisfies: -3.6mm<R6<-2.8mm; The curvature radius R7 of the image side surface of the fourth lens (4) satisfies: -36mm<R8<-25mm.
3. The ultra-wide-angle lens optical system according to claim 1, wherein: The first lens, the second lens, the third lens, and the fourth lens are all high-refractive-index and high-Abbe-number lenses.
4. The ultra-wide-angle lens optical system according to claim 1, wherein: The semi-clear aperture r1 of the object side surface of the first lens (1) satisfies: 7mm<r1<11mm; The semi-clear aperture r2 of the image side surface of the first lens (1) satisfies: 2.1 mm < r2 < 2.4 mm; The semi-clear aperture r3 of the object side surface of the second lens (2) satisfies: 2.2 mm < r3 < 2.4 mm; The semi-clear aperture r4 of the image side surface of the second lens (2) satisfies: 2.9 mm < r4 < 3.3 mm; The semi-clear aperture r5 of the object side surface of the third lens (3) satisfies: 3.2 mm < r5 < 4 mm; The semi-clear aperture r6 of the image side surface of the third lens (3) satisfies: 3mm<r6<4.2mm; The semi-clear aperture r7 of the object side surface of the fourth lens (4) satisfies: 3.4 mm < r7 < 5 mm; The semi-clear aperture r8 of the image side surface of the fourth lens (4) satisfies: 5mm<r8<6mm.
5. The ultra-wide-angle lens optical system according to claim 1, wherein: The first lens (1), the second lens (2), the third lens (3) and the fourth lens (4) are all aspherical lenses.
6. The ultra-wide-angle lens optical system according to claim 1, wherein: The center points of the first lens (1), the second lens (2), the third lens (3) and the fourth lens (4) are all on the same straight line.
7. The ultra-wide-angle lens optical system according to claim 1, wherein: The thickness D1 of the first lens (1) satisfies: 0.4 mm < D1 < 0.6 mm; The thickness D3 of the second lens (2) satisfies: 4.2 mm < D3 < 5.5 mm; The thickness D5 of the third lens (3) satisfies: 1.3 mm < D5 < 2.2 mm; The thickness D6 of the fourth lens (4) satisfies: 0.4 mm < D6 < 0.7 mm.
8. The ultra-wide-angle lens optical system according to claim 1, wherein: The first lens (1), the second lens (2), the third lens (3) and the fourth lens (4) are all made of plastic.