An ultra-thin wide-angle imaging lens
The ultra-thin wide-angle imaging lens addresses the miniaturization and wide-angle imaging challenges by employing a five-lens structure with optimized refractive powers and surface configurations, ensuring high imaging quality and field angle for compact electronic devices.
Patent Information
- Application Number
- CN202110108718.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2021-01-27
- Publication Date
- 2025-01-03
- Estimated Expiration
- 2041-01-27
Smart Images
Figure BDA0002918503400000031 
Figure BDA0002918503400000051 
Figure BDA0002918503400000052
Abstract
Description
Technical Field
[0001] The present invention relates to the field of optical imaging technology, and in particular to an ultra-thin wide-angle imaging lens. Background Art
[0002] With the rapid development of science and technology, especially electronic technology, mobile and lightweight electronic devices have been rapidly popularized, driving the rapid development of imaging module-related technologies used in electronic devices. Imaging modules have been used more and more widely, such as in smart phones, tablet computers, driving recorders, sports cameras, and the continuous upgrading trend of smart phones and other electronic products has also made people have higher and higher requirements for lenses. The traditional imaging lens with a five-lens structure cannot meet the requirements of miniaturization and wide-angle imaging at the same time. Summary of the invention
[0003] The object of the present invention is to provide an ultra-thin wide-angle imaging lens, which can effectively shorten the system length, meet the miniaturization requirements, and improve the imaging quality of wide-angle shooting.
[0004] An ultra-thin wide-angle imaging lens, comprising, from the object side to the image side, an aperture; a first lens, the first lens having positive refractive power, the object side surface of which is concave at the near optical axis, and the image side surface of which is convex at the near optical axis; a second lens, the second lens having negative refractive power, the object side surface of which is convex at the near optical axis, and the image side surface of which is concave at the near optical axis; a third lens, the third lens having positive refractive power, the object side surface of which is convex at the near optical axis, and the image side surface of which is concave at the near optical axis; a fourth lens, the fourth lens having positive refractive power, the object side surface of which is concave at the near optical axis, and the image side surface of which is convex at the near optical axis; a fifth lens, the fifth lens having negative refractive power, refractive power, its object side surface is convex at the near optical axis, and its image side surface is concave at the near optical axis; the optical imaging lens satisfies the following relationship: 0.2≤Sd3 / ImgH≤0.25; |(R8+R10) / (R8-R10)|<0.3; 0<f1 / f<1.5; wherein, Sd3 is the maximum optical effective size of the image side surface of the first lens, ImgH is half of the diagonal length of the effective imaging area of the ultra-thin wide-angle imaging lens, R8 is the curvature radius of the object side surface of the fourth lens, R10 is the curvature radius of the object side surface of the fifth lens, f is the focal length of the imaging lens, and f1 is the focal length of the first lens.
[0005] Furthermore, the ultra-thin wide-angle imaging lens satisfies the following condition: 1.3<CT4 / CT5<2.3, wherein CT4 is the maximum thickness of the fourth lens on the optical axis, and CT5 is the maximum thickness of the fifth lens on the optical axis.
[0006] Furthermore, the ultra-thin wide-angle imaging lens meets the following condition: Distortion<20%, where Distortion is the optical distortion value of the ultra-thin wide-angle imaging lens at 1.0F.
[0007] Furthermore, the ultra-thin wide-angle imaging lens satisfies the following condition: 100<FOV<115, where FOV is the field of view of the ultra-thin wide-angle imaging lens.
[0008] Furthermore, the ultra-thin wide-angle imaging lens satisfies the following condition: 1.9<FNO<2.5, where FNO is the aperture number of the ultra-thin wide-angle imaging lens.
[0009] Furthermore, the ultra-thin wide-angle imaging lens satisfies the following condition: ATmax / CTmax<0.5, wherein ATmax is the maximum distance between two adjacent lenses on the optical axis, and CTmax is the maximum thickness of a single lens on the optical axis.
[0010] Furthermore, the ultra-thin wide-angle imaging lens satisfies the following condition: f / BFL<3.1, where BFL is the distance from the top of the image-side surface of the fifth lens to the imaging surface.
[0011] Furthermore, the ultra-thin wide-angle imaging lens satisfies the following condition: 0<|f3 / f2|<2.5, wherein f2 is the focal length of the second lens, and f3 is the focal length of the third lens.
[0012] Furthermore, the ultra-thin wide-angle imaging lens satisfies the following condition: 1.5<CT4 / CT3<2.5, wherein CT4 is the maximum thickness of the fourth lens on the optical axis, and CT5 is the maximum thickness of the fifth lens on the optical axis.
[0013] Furthermore, the object-side surfaces and image-side surfaces of the first lens, the second lens, the third lens, the fourth lens, and the fifth lens are all aspherical surfaces, and there is no relative movement between the lenses.
[0014] Compared with the prior art, the beneficial effects of the present invention are: the five-lens structure can effectively shorten the system length, adapt to various electronic devices, and meet the needs of miniaturization and image quality. Through the five-lens structure and the reasonable setting of the surface structure and optical parameters of each lens, high imaging quality can be maintained while increasing the imaging field angle, so as to improve the wide-angle imaging performance, and it is suitable for use in various portable devices (such as mobile phones, etc.) that need to be equipped with wide-angle imaging requirements. BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Figure 1 FIG. 4 is a schematic structural diagram of a first embodiment of an ultra-thin wide-angle imaging lens according to the present invention.
[0016] Figure 2 Graph showing astigmatism and distortion of the first embodiment of the ultra-thin wide-angle imaging lens of the present invention.
[0017] Figure 3 FIG. 4 is a spherical aberration curve diagram of the first embodiment of the ultra-thin wide-angle imaging lens of the present invention.
[0018] Figure 4 FIG. 4 is a schematic structural diagram of a second embodiment of an ultra-thin wide-angle imaging lens according to the present invention.
[0019] Figure 5 Graph showing astigmatism and distortion of the second embodiment of the ultra-thin wide-angle imaging lens of the present invention.
[0020] Figure 6 FIG. 4 is a spherical aberration curve diagram of the second embodiment of the ultra-thin wide-angle imaging lens of the present invention.
[0021] Figure 7 FIG. 4 is a schematic structural diagram of a third embodiment of the ultra-thin wide-angle imaging lens of the present invention.
[0022] Figure 8 Graph showing astigmatism and distortion of the third embodiment of the ultra-thin wide-angle imaging lens of the present invention.
[0023] Fig. 9 FIG. 4 is a spherical aberration curve diagram of the third embodiment of the ultra-thin wide-angle imaging lens of the present invention. DETAILED DESCRIPTION
[0024] In order to facilitate the understanding of the present invention, the present invention will be described more fully below with reference to the relevant drawings. The drawings show preferred embodiments of the present invention. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein.
[0025] In the description of the present invention, the object side refers to the side of the lens facing the subject, and the image side refers to the side of the lens facing the imaging surface. When a section is made at any point on the object side surface of the lens, the surface is always located on the image side of the section, and its curvature radius is positive, then the object side surface of the lens is convex; otherwise, the object side surface of the lens is concave, and its curvature radius is negative.
[0026] When a section is made at any point on the image-side surface of the lens, the surface is always on the object side of the section, and its radius of curvature is negative, then the image-side surface of the lens is convex; otherwise, the image-side surface of the lens is concave, and its radius of curvature is positive.
[0027] If a section is made at any point on the object side surface or image side surface of the lens, and the surface has part on the image side and part on the object side of the section, then there is an inflection point on the surface. The above method still applies to judging the convexity of the object side and image side surfaces near the optical axis.
[0028] In addition, the aspheric curve equation of each lens is expressed as follows:
[0029]
[0030] Among them, Z is the distance vector height from the origin of the aspherical surface when the aspherical surface is at a height r along the optical axis direction, c is the paraxial curvature of the aspherical surface (the radius of curvature R = 1 / c, which is the inverse of the curvature); k is the cone coefficient; Ai is the i-th order coefficient of the aspherical surface, and the high-order coefficients used in the present invention are A4, A6, A8, A10, A12, A14, A16, A18, and A20.
[0031] like Figures 1 to 3 As shown in the figure, in the first embodiment, the ultra-thin wide-angle imaging lens of the present invention includes, from the object side to the image side, an aperture not shown, a first lens 11, a second lens 12, a third lens 13, a fourth lens 14, a fifth lens 15, and a filter 16. Among them, the positions of the first lens 11, the second lens 12, the third lens 13, the fourth lens 14, and the fifth lens 15 are relatively fixed, and the object side surface and the image side surface are both aspherical surfaces.
[0032] Specifically, the first lens 11 has positive refractive power, and its object side surface is concave at the near optical axis, and its image side surface is convex at the near optical axis. The object side surface of the first lens 11 is set as a concave surface, and a positive refractive power configuration is adopted, which can shorten the total optical length to meet the miniaturization requirements. The object side surface of the first lens 11 is concave at the near optical axis, and the image side surface is convex at the near optical axis, which can effectively balance low-order aberrations.
[0033] The second lens 12 has negative refractive power, and its object side surface is convex at the near optical axis, and its image side surface is concave at the near optical axis. The second lens 12 has negative refractive power, which is beneficial to eliminate the aberration generated by the first lens 11, and its object side surface is convex at the near optical axis, and its image side surface is concave at the near optical axis, which helps to strengthen the correction of paraxial spherical aberration and off-axis aberration of the correction system.
[0034] The third lens 13 has positive refractive power, its object side surface is convex near the optical axis, and its image side surface is concave near the optical axis. The third lens 13 has positive refractive power and its object side surface is convex near the optical axis, and its image side surface is concave near the optical axis, which can effectively correct the paraxial spherical aberration and reduce the peripheral astigmatism field curvature.
[0035] The fourth lens 14 has positive refractive power, its object side surface is concave near the optical axis, and its image side surface is convex near the optical axis. The fourth lens 14 has positive refractive power, its object side surface is concave near the optical axis, and its image side surface is convex near the optical axis, which helps to strengthen the correction of astigmatism.
[0036] The fifth lens 15 has negative refractive power, its object side surface is convex at the near optical axis, and its image side surface is concave at the near optical axis. The fifth lens 15 has negative refractive power and its object side surface is convex at the near optical axis, and its image side surface is concave at the near optical axis, which helps to move the principal point of the optical photography system away from the image side end, thereby effectively shortening the overall length of the optical imaging system, which is conducive to the miniaturization of the system, and can correct off-axis aberrations to improve peripheral imaging quality.
[0037] With the above structure, reasonable material selection and refractive power matching, when certain conditions are met, the entire optics has better light convergence ability, which can meet the imaging requirements and achieve the effect of wide-angle photography.
[0038] The ultra-thin wide-angle imaging lens of this embodiment satisfies the relationship: 0.2≤Sd3 / ImgH≤0.25, where Sd3 is the maximum optical effective size of the image-side surface of the first lens 11, and ImgH is half of the diagonal length of the effective imaging area of the ultra-thin wide-angle imaging lens. Satisfying the above relationship can make the lens meet a larger field of view while better compressing the optical effective diameter size of the first lens 11, which is conducive to the realization of a small head of the lens.
[0039] The ultra-thin wide-angle imaging lens of this embodiment satisfies the relationship: |(R8+R10) / (R8-R10)|<0.3, where R8 is the radius of curvature of the object-side surface of the fourth lens 14, and R10 is the radius of curvature of the object-side surface of the fifth lens 15. A more reasonable curvature helps the rear end of the lens group to balance the astigmatism and field curvature of the imaging lens group, thereby improving the imaging quality.
[0040] The ultra-thin wide-angle imaging lens of this embodiment satisfies the relationship: 0<f1 / f<1.5, where f is the focal length of the imaging lens, and f1 is the focal length of the first lens 11. Satisfying the above conditions can make the first lens 11 have sufficient refractive power, which is beneficial to shorten the total optical length of the lens, and at the same time provides sufficient refractive power for the wide-angle lens, which helps the edge light to be better converged when the wide-angle lens is imaging at a large angle to ensure the imaging quality.
[0041] Preferably, the ultra-thin wide-angle imaging lens satisfies the following condition: 1.3<CT4 / CT5<2.3, wherein CT4 is the maximum thickness of the fourth lens 14 on the optical axis, and CT5 is the maximum thickness of the fifth lens 15 on the optical axis. The above structure can adjust the surface shapes of the fourth lens 14 and the fifth lens 15 to adjust the off-axis aberration.
[0042] Preferably, the ultra-thin wide-angle imaging lens meets the following condition: Distortion < 20%, where Distortion is the optical distortion value of the ultra-thin wide-angle imaging lens at 1.0 F. Meeting the above condition can be used to limit the distortion of the optical system, which helps to maintain the deformation of the captured image.
[0043] Preferably, the ultra-thin wide-angle imaging lens satisfies the following conditions: 100<FOV<115, FOV is the field of view of the ultra-thin wide-angle imaging lens. Meeting the above conditions can ensure that the wide-angle lens has a sufficient field of view to ensure a sufficient imaging range while ensuring that the imaging quality is satisfactory.
[0044] Preferably, the ultra-thin wide-angle imaging lens satisfies the following condition: 1.9<FNO<2.5, where FNO is the aperture number of the ultra-thin wide-angle imaging lens. A more reasonable aperture number can ensure that the overall imaging lens group has both a wide angle and sufficient light intake.
[0045] Preferably, the ultra-thin wide-angle imaging lens meets the following conditions: ATmax / CTmax<0.5, where ATmax is the maximum distance between two adjacent lenses on the optical axis, and CTmax is the maximum thickness of a single lens on the optical axis. Meeting the above conditions can effectively balance the configuration of the imaging lens group and achieve better space utilization.
[0046] Preferably, the ultra-thin wide-angle imaging lens meets the following condition: f / BFL<3.1, BFL is the distance from the top of the image side surface of the fifth lens 15 to the imaging surface. The above structure can facilitate the assembly of the wide-angle lens.
[0047] Preferably, the ultra-thin wide-angle imaging lens satisfies the following condition: 0<|f3 / f2|<2.5, where f2 is the focal length of the second lens 12, and f3 is the focal length of the third lens 13. Meeting the above condition can balance the refractive power of the lens group to effectively reduce sensitivity.
[0048] Preferably, the ultra-thin wide-angle imaging lens satisfies the following condition: 1.5<CT4 / CT3<2.5, wherein CT4 is the maximum thickness of the fourth lens 14 on the optical axis, and CT5 is the maximum thickness of the fifth lens 15 on the optical axis. Meeting the above conditions can control the center thickness of each lens of the wide-angle lens within a reasonable ratio range, which helps to reduce the overall sensitivity of the optical system.
[0049] The ultra-thin wide-angle imaging lens of the present invention will be described in detail through the following specific embodiments with reference to the accompanying drawings.
[0050] In the first embodiment, please combine Figures 1 to 3 In the first embodiment, the ultra-thin wide-angle imaging lens satisfies Table 1-1, Table 1-2, and Table 1-3.
[0051] Table 1-1 shows the basic parameters of the optical lens of the first embodiment:
[0052]
[0053] Table 1-2 shows the aspheric coefficients of each lens in the first embodiment:
[0054]
[0055]
[0056] Table 1-3 shows the values of the conditional expressions in the first embodiment:
[0057]
[0058] In the second embodiment, please combine Figures 4 to 6 The ultra-thin wide-angle imaging lens of the present invention includes, from the object side to the image side, an aperture not shown, a first lens 21, a second lens 22, a third lens 23, a fourth lens 24, a fifth lens 25, and a filter 26. Among them, the positions of the first lens 21, the second lens 22, the third lens 23, the fourth lens 24, and the fifth lens 25 are relatively fixed, and the object side surface and the image side surface are both aspherical. In the second embodiment, the ultra-thin wide-angle imaging lens satisfies Table 2-1, Table 2-2, and Table 2-3.
[0059] Table 2-1 shows the basic parameters of the optical lens of the second embodiment:
[0060]
[0061]
[0062] Table 2-2 shows the aspheric coefficients of each lens in the second embodiment:
[0063]
[0064] Table 2-3 shows the values of the conditional expressions in the second embodiment:
[0065]
[0066] The third embodiment, please combine Figures 7 to 9 The ultra-thin wide-angle imaging lens of the present invention includes, from the object side to the image side, an aperture not shown, a first lens 31, a second lens 32, a third lens 33, a fourth lens 34, a fifth lens 35, and a filter 36. Among them, the positions of the first lens 31, the second lens 32, the third lens 33, the fourth lens 34, and the fifth lens 35 are relatively fixed, and the object side surface and the image side surface are both aspherical. In the second embodiment, the ultra-thin wide-angle imaging lens satisfies Table 3-1, Table 3-2, and Table 3-3.
[0067] Table 3-1 shows the basic parameters of the optical lens of the third embodiment:
[0068]
[0069]
[0070] Table 3-2 shows the aspheric coefficients of each lens in the third embodiment:
[0071]
[0072] Table 3-3 shows the values of the conditional expressions in the third embodiment:
[0073]
[0074] In order to facilitate comparison of the above three embodiments, the following table summarizes the values obtained by each expression under the corresponding conditions of each embodiment:
[0075] condition Example 1 Example 2 Example 3 maximum Minimum Sd3 / ImgH 0.2320 0.2450 0.2410 0.2450 0.2320 CT4 / CT5 1.9168 2.2005 1.8603 2.2005 1.8603 |(R8+R10) / (R8-R10)| 0.1905 0.2523 0.1865 0.2523 0.1865 f1 / f 1.3212 1.2022 1.2168 1.3212 1.2022 Distortion 15.8664％ 17.2029％ 12.7884％ 17.2029％ 12.7884％ ATmax / CTmax 0.4416 0.4058 0.3740 0.4416 0.374 CT4 / CT3 2.1839 2.0694 2.1402 2.1839 2.0694 FOV 106.3° 111.18° 105.52° 111.18° 105.52 |f2 / f3| 1.8242 2.2807 2.0196 2.2807 1.8242 f / BFL 2.83333 2.7859 2.9164 2.9164 2.7859 FNO 2.3 2.18 2.3 2.3 2.18
[0076] The five-lens structure of the ultra-thin wide-angle imaging lens in the above-mentioned embodiment can effectively shorten the system length, be suitable for various electronic devices, and meet the requirements of miniaturization while maintaining image quality. Through the five-lens structure and the reasonable setting of the surface structure and optical parameters of each lens, high imaging quality can be maintained while increasing the imaging field angle, so as to improve the wide-angle imaging performance, and is suitable for use in various portable devices (such as mobile phones, etc.) that need to be equipped with wide-angle imaging requirements.
[0077] In the description of the present invention, it is necessary to understand that terms such as "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.
[0078] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.
[0079] Although the present invention is described in conjunction with the above specific embodiments, it is obvious that those skilled in the art can make many substitutions, modifications and changes according to the above content. Therefore, all such substitutions, improvements and changes are included in the spirit and scope of the appended claims.
Claims
1. An ultra-thin wide-angle imaging lens, characterized in that: From the object side to the image side, it includes: Aperture; A first lens, the first lens having positive refractive power, an object-side surface thereof being concave near the optical axis, and an image-side surface thereof being convex near the optical axis; A second lens having negative refractive power, an object-side surface thereof being convex near the optical axis, and an image-side surface thereof being concave near the optical axis; A third lens having positive refractive power, an object-side surface thereof being convex near the optical axis, and an image-side surface thereof being concave near the optical axis; a fourth lens having positive refractive power, an object-side surface thereof being concave near the optical axis, and an image-side surface thereof being convex near the optical axis; a fifth lens having negative refractive power, an object-side surface thereof being convex near the optical axis, and an image-side surface thereof being concave near the optical axis; The ultra-thin wide-angle imaging lens satisfies the following relationship: 0.2≤Sd3 / ImgH≤0.25; |(R8+R10) / (R8-R10)|<0.3; 0<f1 / f<1.5; Wherein, Sd3 is the maximum optical effective size of the image-side surface of the first lens, ImgH is half of the diagonal length of the effective imaging area of the ultra-thin wide-angle imaging lens, R8 is the curvature radius of the object-side surface of the fourth lens, R10 is the curvature radius of the object-side surface of the fifth lens, f is the focal length of the imaging lens, and f1 is the focal length of the first lens; The ultra-thin wide-angle imaging lens satisfies the following condition: 0<|f3 / f2|<2.5, where f2 is the focal length of the second lens, and f3 is the focal length of the third lens; The object-side surfaces and image-side surfaces of the first lens, the second lens, the third lens, the fourth lens, and the fifth lens are all aspherical surfaces, and there is no relative movement between the lenses.
2. The ultra-thin wide-angle imaging lens according to claim 1, characterized in that: The ultra-thin wide-angle imaging lens satisfies the following condition: 1.3<CT4 / CT5<2.3, wherein CT4 is the maximum thickness of the fourth lens on the optical axis, and CT5 is the maximum thickness of the fifth lens on the optical axis.
3. The ultra-thin wide-angle imaging lens according to claim 1, characterized in that: The ultra-thin wide-angle imaging lens meets the following condition: Distortion<20%, where Distortion is the optical distortion value of the ultra-thin wide-angle imaging lens at 1.0F.
4. The ultra-thin wide-angle imaging lens according to claim 1, characterized in that: The ultra-thin wide-angle imaging lens meets the following condition: 100<FOV<115, FOV is the field of view angle of the ultra-thin wide-angle imaging lens.
5. The ultra-thin wide-angle imaging lens according to claim 1, characterized in that: The ultra-thin wide-angle imaging lens meets the following condition: 1.9<FNO<2.5, where FNO is the aperture number of the ultra-thin wide-angle imaging lens.
6. The ultra-thin wide-angle imaging lens according to claim 1, characterized in that: The ultra-thin wide-angle imaging lens meets the following condition: ATmax / CTmax<0.5, wherein ATmax is the maximum distance between two adjacent lenses on the optical axis, and CTmax is the maximum thickness of a single lens on the optical axis.
7. The ultra-thin wide-angle imaging lens according to claim 1, characterized in that: The ultra-thin wide-angle imaging lens meets the following condition: f / BFL<3.1, where BFL is the distance from the top of the image side surface of the fifth lens to the imaging surface.
8. The ultra-thin wide-angle imaging lens according to claim 1, characterized in that: The ultra-thin wide-angle imaging lens satisfies the following condition: 1.5<CT4 / CT3<2.5, wherein CT4 is the maximum thickness of the fourth lens on the optical axis, and CT3 is the maximum thickness of the third lens on the optical axis.