Optical lens

Abstract

This invention discloses an optical lens, which comprises, along the optical axis from the object side to the imaging plane, the following components in sequence: a first lens with positive optical power, having a convex object side and a concave image side; an aperture stop; a second lens with positive optical power, having a convex object side and a convex image side; a third lens with negative optical power; a fourth lens with positive optical power, having a concave object side and a convex image side; and a fifth lens with negative optical power, having a convex object side near the optical axis and a concave image side near the optical axis. This optical lens has advantages such as a small head, a wide viewing angle, a small size, and low distortion, meeting the demand for thinner and lighter portable electronic devices.

Description

Technical Field

[0001] This invention relates to the field of imaging lens technology, and in particular to an optical lens. Background Technology

[0002] With increasingly fierce market competition, manufacturers of portable electronic devices are rapidly updating the technology of their products. As a crucial component of portable electronic devices, optical lenses are also undergoing rapid technological advancements, evolving from simple single-pixel lenses to diverse imaging techniques. Among these, wide-angle optical lenses, due to their advantages such as wide shooting range, large depth of field, and short focal length, have been widely used in electronic devices and possess broad market prospects.

[0003] Currently, most wide-angle lenses on the market adopt a structure of 5 or more elements, resulting in a large lens size that cannot well adapt to the trend of thinner and lighter portable electronic devices. At the same time, the optical distortion of conventional wide-angle lenses is over 10%, resulting in significant distortion at the edges of the image during imaging, which seriously affects the consumer's photography experience. Summary of the Invention

[0004] Therefore, the purpose of this invention is to provide an optical lens that has at least the advantages of a small head and a wide field of view, in order to meet consumers' higher photography needs.

[0005] The embodiments of the present invention achieve the above-mentioned objectives through the following technical solutions.

[0006] This invention discloses an optical lens, which comprises, along the optical axis from the object side to the imaging plane, the following components in sequence: a first lens with positive optical power, the object side of which is convex and the image side of which is concave; an aperture stop; a second lens with positive optical power, the object side of which is convex and the image side of which is convex; a third lens with negative optical power; a fourth lens with positive optical power, the object side of which is concave and the image side of which is convex; and a fifth lens with negative optical power, the object side of which is convex near the optical axis and the image side of which is concave near the optical axis.

[0007] Compared with existing technologies, the optical lens provided by this invention consists of only 5 lenses with specific optical power and specific shape, and the aperture position is reasonably arranged, so that the optical lens has the advantages of small head, large angle of view, small size and small distortion. It can not only meet the needs of portable electronic devices to be thinner and lighter, but also reduce the size of the head hole and improve the phenomenon of image distortion at the edge of the lens, thus greatly enhancing its market competitiveness. Attached Figure Description

[0008] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0009] Figure 1 This is a schematic diagram of the structure of the optical lens according to the first embodiment of the present invention;

[0010] Figure 2 This is a field curvature curve diagram of the optical lens according to the first embodiment of the present invention;

[0011] Figure 3 This is a distortion curve diagram of the optical lens according to the first embodiment of the present invention;

[0012] Figure 4 This is a graph showing the on-axis spherical aberration and chromatic aberration of the optical lens according to the first embodiment of the present invention.

[0013] Figure 5 This is a lateral chromatic aberration curve of the optical lens according to the first embodiment of the present invention;

[0014] Figure 6 This is a schematic diagram of the structure of the optical lens according to the second embodiment of the present invention;

[0015] Figure 7 This is a field curvature curve diagram of the optical lens according to the second embodiment of the present invention;

[0016] Figure 8 This is a distortion curve diagram of the optical lens according to the second embodiment of the present invention;

[0017] Figure 9 This is a graph showing the on-axis spherical aberration and chromatic aberration of the optical lens according to the second embodiment of the present invention.

[0018] Figure 10 This is a lateral chromatic aberration curve of the optical lens according to the second embodiment of the present invention;

[0019] Figure 11 This is a schematic diagram of the optical lens structure according to the third embodiment of the present invention;

[0020] Figure 12 This is a field curvature curve diagram of the optical lens according to the third embodiment of the present invention;

[0021] Figure 13 This is a distortion curve diagram of the optical lens according to the third embodiment of the present invention;

[0022] Figure 14 This is a graph showing the on-axis spherical aberration and chromatic aberration of the optical lens according to the third embodiment of the present invention.

[0023] Figure 15 This is a lateral chromatic aberration curve of the optical lens according to the third embodiment of the present invention. Detailed Implementation

[0024] To make the objectives, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Several embodiments of the present invention are shown in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that the disclosure of the present invention will be thorough and complete.

[0025] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. Throughout this specification, the same reference numerals refer to the same elements.

[0026] The present invention proposes an optical lens, which comprises, in sequence along the optical axis from the object side to the imaging plane: a first lens, an aperture stop, a second lens, a third lens, a fourth lens, a fifth lens, and a filter.

[0027] The first lens has positive optical power, with its object side being convex and its image side being concave; the second lens has positive optical power, with its object side being convex and its image side being convex; the third lens has negative optical power; the fourth lens has positive optical power, with its object side being concave and its image side being convex; and the fifth lens has negative optical power, with its object side being convex near the optical axis and its image side being concave near the optical axis.

[0028] In some embodiments, the optical lens satisfies the following condition:

[0029] 15.20< R21 / CT2<32.80; (1)

[0030] -6.60 <R22 / CT2<-5.80; (2)

[0031] Wherein, CT2 represents the center thickness of the second lens, R21 represents the radius of curvature of the object side of the second lens, and R22 represents the radius of curvature of the image side of the second lens. By satisfying conditions (1) and (2), the shape of the second lens can be reasonably arranged so that it can bear a specific range of positive optical power, accelerate the deflection efficiency of light, and help reduce the size of the optical lens and realize the miniaturization of the lens.

[0032] In some embodiments, the optical lens satisfies the following condition:

[0033] -1.0% < DIS < 2.5%; (3)

[0034] 100° < FOV < 105°; (4)

[0035] Wherein, DIS represents the maximum optical distortion of the optical lens, and FOV represents the maximum field of view of the optical lens. Satisfying conditions (3) and (4) ensures that the optical lens has a large field of view imaging while reducing the phenomenon of edge field of view imaging distortion, thus improving the imaging quality of the lens. If condition (3) is exceeded, the edge field of view will produce a large degree of distortion when the lens is imaging in a large field of view, which will affect the imaging quality of the lens; if condition (4) is lower, the imaging field of view of the lens will be reduced, which is not conducive to large-area imaging.

[0036] In some embodiments, the optical lens satisfies the following condition:

[0037] 0.55< D1 / D4 < 0.62; (5)

[0038] Where D1 represents the effective diameter of the first lens and D4 represents the effective diameter of the fourth lens. By satisfying condition (5), the height difference between the first and second lenses can be reasonably arranged, which is beneficial for the lens to have a smaller head size and can effectively improve the screen ratio.

[0039] In some embodiments, the optical lens satisfies the following condition:

[0040] 1.99 < f / ENPD < 2.21; (6)

[0041] -0.01 <SAG31 / R31<0.11; (7)

[0042] Where f represents the effective focal length of the optical lens, ENPD represents the entrance pupil diameter of the optical lens, SAG31 represents the sagitta of the object side of the third lens, and R31 represents the radius of curvature of the object side of the third lens. By satisfying conditions (6) and (7), the shape and sagitta of the object side of the third lens on the near-optical axis can be reasonably arranged, which is beneficial to improving the light throughput of the lens and enabling the lens to form clear images even in low-light environments.

[0043] In some embodiments, the optical lens satisfies the following condition:

[0044] 1.30 <(SAG11+SAG12) / ET1< 4.75; (8)

[0045] Wherein, SAG11 represents the sagitta of the object-side surface of the first lens, SAG12 represents the sagitta of the image-side surface of the first lens, and ET1 represents the edge thickness of the first lens. Satisfying condition (8) allows for a reasonable arrangement of the sagitta distribution between the object-side and image-side surfaces of the first lens, which is beneficial for reducing the sensitivity of the first lens and improving the production yield of the lens.

[0046] In some embodiments, the optical lens satisfies the following condition:

[0047] 1.80 < R21 / f2 <3.55; (9)

[0048] Where R21 represents the radius of curvature of the object side of the second lens, and f2 represents the effective focal length of the second lens. By satisfying condition (9), the shape of the second lens can be reasonably arranged, the deflection efficiency of light entering the lens can be accelerated, which is conducive to shortening the total optical length of the lens and realizing the miniaturization of the lens.

[0049] In some embodiments, the optical lens satisfies the following condition:

[0050] -0.16<ET3 / R31<0.01; (10)

[0051] Wherein, ET3 represents the edge thickness of the third lens, and R31 represents the radius of curvature of the object side of the third lens. Satisfying condition (10) allows for a reasonable arrangement of the optical power of the third lens, which helps to mitigate the tendency of light deflection, thereby reducing the sensitivity of the entire optical system and improving the yield of optical lens assembly.

[0052] In some embodiments, the optical lens satisfies the following condition:

[0053] 0.50 < f4 / f < 0.69; (11)

[0054] 0.02< ET4 / TTL <0.16; (12)

[0055] Where f4 represents the effective focal length of the fourth lens, f represents the effective focal length of the optical lens, ET4 represents the edge thickness of the fourth lens, and TTL represents the total optical length of the optical lens. By satisfying conditions (11) and (12), the shape and edge thickness of the fourth lens can be reasonably controlled, enabling it to bear a reasonable positive optical power, accelerate the deflection trend of light, and facilitate the miniaturization of the optical lens.

[0056] In some embodiments, the optical lens satisfies the following condition:

[0057] 0.40<(CT1+CT2+CT3) / (CT4+CT5) <1.05; (13)

[0058] Wherein, CT1 represents the center thickness of the first lens, CT2 represents the center thickness of the second lens, CT3 represents the center thickness of the third lens, CT4 represents the center thickness of the fourth lens, and CT5 represents the center thickness of the fifth lens. Satisfying condition (13) allows for a reasonable arrangement of the center thicknesses of each lens along the optical axis, which is beneficial for forming a compact structure of the optical lens.

[0059] In some embodiments, the optical lens satisfies the following condition:

[0060] 1.35 < f12 / f <2.26; (14)

[0061] Where f12 represents the combined focal length of the first lens and the second lens, and f represents the effective focal length of the optical lens. By satisfying condition (14), the shapes of the first lens and the second lens can be reasonably arranged, the deflection efficiency of light entering the lens can be accelerated, and the overall optical length of the lens can be shortened.

[0062] In some embodiments, the optical lens satisfies the following condition:

[0063] -3.65< f3 / f <-2.10; (15)

[0064] Where f3 represents the effective focal length of the third lens, and f represents the effective focal length of the optical lens. By satisfying condition (15), the optical power of the third lens can be reasonably arranged, which is beneficial to reduce the tendency of light deflection, thereby reducing the sensitivity of the entire optical system and improving the yield of optical lens assembly.

[0065] In some embodiments, the optical lens satisfies the following condition:

[0066] -3.65< f5 / R52 <-2.20; (16)

[0067] Where f5 represents the effective focal length of the fifth lens, and R52 represents the radius of curvature of the image side of the fifth lens. By satisfying condition (16), the shape of the fifth lens can be reasonably arranged, the projection height of light on the image plane can be reduced, which is beneficial to the correction of peripheral field aberrations and coma, and improves the imaging quality of the optical lens.

[0068] In some embodiments, the first lens, the second lens, the third lens, the fourth lens, and the fifth lens may all be glass lenses or plastic lenses, or a combination of plastic lenses and glass lenses.

[0069] In some embodiments, the first lens, second lens, third lens, fourth lens, and fifth lens are all plastic aspherical lenses. By using aspherical lenses, the optical lens can have better image quality, a more compact structure, and a shorter overall optical length.

[0070] The present invention will be further described below with reference to several embodiments. In each embodiment, the thickness, radius of curvature, and material selection of each lens in the optical lens are different; for specific differences, please refer to the parameter tables of each embodiment. The following embodiments are merely preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the following embodiments. Any changes, substitutions, combinations, or simplifications made without departing from the innovative points of the present invention should be considered equivalent substitutions and are included within the protection scope of the present invention.

[0071] In various embodiments of the present invention, the aspherical surface profile of each lens satisfies the following equation:

[0072] ;

[0073] Where z is the distance vector from the vertex of the aspherical surface at a height of h along the optical axis, c is the paraxial curvature of the surface, k is the quadratic surface coefficient, and A 2i For the aspherical surface shape coefficient of the 2ith order.

[0074] First Embodiment

[0075] Please refer to the structural schematic diagram of the optical lens 100 provided in the first embodiment of the present invention. Figure 1 The optical lens 100 includes, along the optical axis from the object side to the imaging plane S13, the following components in sequence: a first lens L1, an aperture ST, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, and a filter G1.

[0076] The first lens L1 is a plastic aspherical lens with positive optical power, with its object-side surface S1 being convex and its image-side surface S2 being concave. The second lens L2 is a plastic aspherical lens with positive optical power, with its object-side surface S3 being convex and its image-side surface S4 being convex. The third lens L3 is a plastic aspherical lens with negative optical power, with its object-side surface S5 being convex near the optical axis and its image-side surface S6 being concave near the optical axis. The fourth lens L4 is a plastic aspherical lens with positive optical power, with its object-side surface S7 being concave and its image-side surface S8 being convex. The fifth lens L5 is a plastic aspherical lens with negative optical power, with its object-side surface S9 being convex near the optical axis and its image-side surface S10 being concave near the optical axis. The filter G1 has an object-side surface S11 and an image-side surface S12.

[0077] The relevant parameters of each lens element in the optical lens 100 provided in this embodiment are shown in Table 1, where R represents the radius of curvature (unit: mm), d represents the optical surface spacing (unit: mm), and n d V represents the d-line refractive index of the material. d The Abbe number representing the material.

[0078] Table 1

[0079]

[0080] The surface shape coefficients of each aspherical surface of the optical lens 100 in this embodiment are shown in Table 2.

[0081] Table 2

[0082]

[0083] In this embodiment, the field curvature, distortion, on-axis spherical aberration, chromatic aberration, and lateral chromatic aberration curves of the optical lens 100 are respectively as follows: Figure 2 , Figure 3 , Figure 4 and Figure 5 As shown, by Figures 2 to 5 It can be seen that the field curvature is controlled within ±0.05mm, the optical distortion is controlled within ±1.3%, the axial chromatic difference between the minimum and maximum wavelengths is controlled within ±0.01mm, and the chromatic difference of each wavelength relative to the center wavelength in different fields of view is controlled within ±1.5 micrometers. This indicates that the field curvature, distortion, spherical aberration, and chromatic aberration of the optical lens 100 are well corrected.

[0084] Second Embodiment

[0085] Please refer to the structural schematic diagram of the optical lens 200 provided in this embodiment. Figure 6 The structure of the optical lens 200 in this embodiment is basically the same as that of the optical lens 100 in the first embodiment, and the materials are also the same, but the center thickness and edge thickness of each lens are different.

[0086] The relevant parameters of each lens element in the optical lens 200 provided in this embodiment are shown in Table 3.

[0087] Table 3

[0088]

[0089] The surface coefficients of each aspherical surface of the optical lens 200 in this embodiment are shown in Table 4.

[0090] Table 4

[0091]

[0092] In this embodiment, the curves of field curvature, distortion, on-axis spherical aberration, chromatic aberration, and lateral chromatic aberration of the optical lens 200 are respectively as follows: Figure 7 , Figure 8 , Figure 9 and Figure 10 As shown, by Figures 7 to 10 It can be seen that the field curvature is controlled within ±0.05mm, the optical distortion is controlled within ±2%, the axial chromatic difference between the minimum and maximum wavelengths is controlled within ±0.025mm, and the chromatic difference of each wavelength relative to the center wavelength in different fields of view is controlled within ±1.5 micrometers. This indicates that the field curvature, distortion, spherical aberration, and chromatic aberration of the optical lens 200 are well corrected.

[0093] Third Embodiment

[0094] Please refer to the schematic diagram of the optical lens 300 provided in this embodiment. Figure 11 The optical lens 300 in this embodiment has a similar structure and shape to the optical lens 100 in the first embodiment, but the shape of the third lens on the near-optical axis has changed.

[0095] The relevant parameters of each lens element in the optical lens 300 in this embodiment are shown in Table 5.

[0096] Table 5

[0097]

[0098] The surface shape coefficients of each aspherical surface of the optical lens 300 in this embodiment are shown in Table 6.

[0099] Table 6

[0100]

[0101] In this embodiment, the curves of field curvature, distortion, on-axis spherical aberration, chromatic aberration, and lateral chromatic aberration of the optical lens 300 are respectively as follows: Figure 12 , Figure 13 , Figure 14 and Figure 15 As shown, by Figures 12 to 15 It can be seen that the field curvature is controlled within ±0.05mm, the optical distortion is controlled within ±2.1%, the axial chromatic difference between the minimum and maximum wavelengths is controlled within ±0.025mm, and the chromatic difference of each wavelength relative to the center wavelength in different fields of view is controlled within ±2 micrometers. This indicates that the field curvature, distortion, spherical aberration, and chromatic aberration of the optical lens 300 are well corrected.

[0102] Table 7 shows the optical characteristics corresponding to the three embodiments above, mainly including the effective focal length f of the optical lens in each embodiment, the effective focal lengths f1, f2, f3, f4, and f5 of each lens element, the total optical length TTL, and the values ​​corresponding to each of the above conditional expressions.

[0103] Table 7

[0104]

[0105] In summary, the optical lens provided in the embodiments of the present invention has at least the following advantages:

[0106] (1) The optical lens provided by the present invention uses five lenses with specific surface shapes and reasonable optical power distribution, which gives the optical lens advantages such as small head, large angle of view, small size and small distortion.

[0107] (2) The optical lens provided by the present invention has a wide field of view and a large depth of field, which can effectively ensure that the foreground and background objects of the subject can be clearly reproduced on the screen, and the foreground and background of the subject are strong, with a perspective effect, which can enhance the appeal of the screen.

[0108] (3) The optical lens provided by the present invention has small distortion and weak distortion when imaging at the edges, which is beneficial to improving the imaging quality.

[0109] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0110] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. An optical lens, characterized in that, Along the optical axis from the object side to the imaging plane, the following are included in sequence: A first lens with positive optical power, wherein the object side of the first lens is convex and the image side of the first lens is concave; Aperture; A second lens with positive optical power, wherein the object-side surface of the second lens is convex and the image-side surface of the second lens is convex; A third lens with negative optical power; A fourth lens with positive optical power, wherein the object-side surface of the fourth lens is concave and the image-side surface of the fourth lens is convex; A fifth lens with negative optical power, wherein the object-side surface of the fifth lens is convex near the optical axis and the image-side surface of the fifth lens is concave near the optical axis; The optical lens satisfies the following condition: 1.35 < f12 / f < 2.26; -3.65 < f3 / f < -2.10; 0.50 < f4 / f < 0.69; 1.80 < R21 / f2 < 3.55; Wherein, f12 represents the combined focal length of the first lens and the second lens, f represents the effective focal length of the optical lens, f3 represents the effective focal length of the third lens, f4 represents the effective focal length of the fourth lens, R21 represents the radius of curvature of the object side of the second lens, and f2 represents the effective focal length of the second lens. The optical lens has five lenses with optical power.

2. The optical lens according to claim 1, characterized in that, The optical lens satisfies the following condition: 15.20 < R21 / CT2 < 32.80; -6.60 < R22 / CT2 < -5.80; Wherein, CT2 represents the center thickness of the second lens, R21 represents the radius of curvature of the object side of the second lens, and R22 represents the radius of curvature of the image side of the second lens.

3. The optical lens according to claim 1, characterized in that, The optical lens satisfies the following condition: -1.0% < DIS < 2.5%; 100° < FOV < 105°; Wherein, DIS represents the maximum optical distortion of the optical lens, and FOV represents the maximum field of view of the optical lens.

4. The optical lens according to claim 1, characterized in that, The optical lens satisfies the following condition: 0.55 < D1 / D4 < 0.62; Wherein, D1 represents the effective diameter of the first lens, and D4 represents the effective diameter of the fourth lens.

5. The optical lens according to claim 1, characterized in that, The optical lens satisfies the following condition: 1.99 < f / ENPD < 2.21; -0.01 <SAG31 / R31<0.11; Where f represents the effective focal length of the optical lens, ENPD represents the entrance pupil diameter of the optical lens, SAG31 represents the sagitta of the object side of the third lens, and R31 represents the radius of curvature of the object side of the third lens.

6. The optical lens according to claim 1, characterized in that, The optical lens satisfies the following condition: 1.30 <(SAG11+SAG12) / ET1< 4.75; Wherein, SAG11 represents the sagitta of the object side of the first lens, SAG12 represents the sagitta of the image side of the first lens, and ET1 represents the edge thickness of the first lens.

7. The optical lens according to claim 1, characterized in that, The optical lens satisfies the following condition: 1.809 ≤ R21 / f2 ≤ 3.518; Where R21 represents the radius of curvature of the object side of the second lens, and f2 represents the effective focal length of the second lens.

8. The optical lens according to claim 1, characterized in that, The optical lens satisfies the following condition: -0.16 < ET3 / R31 < 0.01; Wherein, ET3 represents the edge thickness of the third lens, and R31 represents the radius of curvature of the object side surface of the third lens.

9. The optical lens according to claim 1, characterized in that, The optical lens satisfies the following condition: 0.52 ≤ f4 / f ≤ 0.685; 0.02 < ET4 / TTL < 0.16; Wherein, f4 represents the effective focal length of the fourth lens, f represents the effective focal length of the optical lens, ET4 represents the edge thickness of the fourth lens, and TTL represents the total optical length of the optical lens.

10. The optical lens according to claim 1, characterized in that, The optical lens satisfies the following condition: 0.40<(CT1+CT2+CT3) / (CT4+CT5) <1.05; Wherein, CT1 represents the center thickness of the first lens, CT2 represents the center thickness of the second lens, CT3 represents the center thickness of the third lens, CT4 represents the center thickness of the fourth lens, and CT5 represents the center thickness of the fifth lens; The optical lens satisfies the following condition: 1.362≤f12 / f≤2.248; -3.589≤f3 / f≤-2.146; Where f12 represents the combined focal length of the first lens and the second lens, f represents the effective focal length of the optical lens, and f3 represents the effective focal length of the third lens.

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