An optical imaging system, camera module and electronic device

Abstract

The application relates to the field of camera technology, in particular to an optical imaging system, a camera module and electronic equipment. The optical imaging system comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens and a filter arranged in sequence from an object side to an image side along an optical axis. The object side surface of the first lens is a convex surface, and the object side surfaces of the second to sixth lenses are all concave surfaces. One optical surface of the filter is a binary surface. Incident light passes through the first to sixth lenses in sequence, is deflected by the binary surface, and then exits to an imaging surface adjacent to the image side surface of the filter. The optical imaging system satisfies the relationship TTL / ImgH*FOV= or TTL / ImgH*FOV=. TTL is the total length of the optical imaging system, ImgH is the image height of the optical imaging system, and FOV is the field of view of the optical imaging system. The optical system provided by the embodiment improves the imaging quality of the lens module and meets the requirements of simplification and thinning design of the lens module.

Description

Technical Field

[0001] This application relates to the field of camera technology, and more particularly to an optical imaging system, camera module, and electronic device. Background Technology

[0002] Due to limitations in lens materials, once the performance of a mobile phone lens is optimized to a certain level, it is usually necessary to increase the number of lenses to further improve the image quality. However, increasing the number of lenses leads to increased complexity and manufacturing difficulty in the optical system, resulting in a thicker lens module and the lens protruding from the phone's back cover, affecting the phone's aesthetics. Therefore, how to improve the image quality of the lens module while simultaneously meeting the demands for simplified and thinner lens module designs is a pressing technical challenge that needs to be addressed. Summary of the Invention

[0003] This application provides an optical imaging system that solves the technical problem of how to improve the imaging quality of a lens module while meeting the requirements for simplified and thinner lens module design.

[0004] In a first aspect, this application provides an optical imaging system, the optical imaging system comprising: a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a filter arranged sequentially along the optical axis from the object side to the image side;

[0005] The object-side surface of the first lens is convex, while the object-side surfaces of the second to sixth lenses are all concave.

[0006] One optical surface of the filter is a binary surface; the incident light passes through the first lens to the sixth lens in sequence, is refracted by the binary surface, and then exits onto the imaging surface adjacent to the image side of the filter.

[0007] The optical imaging system satisfies the following relationship:

[0008] TTL / ImgH×FOV= ;or,

[0009] TTL / ImgH×FOV= ;

[0010] Where TTL is the total length of the optical imaging system; ImgH is the image height of the optical imaging system; and FOV is the field of view of the optical imaging system.

[0011] As an optional implementation, the optical imaging system satisfies the following relationship:

[0012] 25≤|V2-V3|≤33.5;

[0013] Wherein, V2 is the Abbe number of the second lens; V3 is the Abbe number of the third lens.

[0014] As an optional implementation, the optical imaging system satisfies the following relationship:

[0015] |N2-N3|≥0.1;

[0016] Wherein, N2 is the refractive index of the second lens, and N3 is the refractive index of the third lens.

[0017] As an optional implementation, the optical imaging system satisfies the following relationship:

[0018] 0.75≤f1 / f≤0.95;

[0019] 0.2≤f2 / f6≤0.5;

[0020] 1.0≤|f4 / f5|≤3.5;

[0021] -50≤f2+f3+f4+f5+f6≤-10;

[0022] Wherein, f is the effective focal length of the optical imaging system; f1 is the focal length of the first lens; f2 is the focal length of the second lens; f3 is the focal length of the third lens; f4 is the focal length of the fourth lens; f5 is the focal length of the fifth lens; and f6 is the focal length of the sixth lens.

[0023] As an optional implementation, the optical imaging system satisfies the following relationship:

[0024] 0.25≤CT23 / L1R1≤0.45;

[0025] 0.4≤(CT56+CT78) / CT67≤0.6,

[0026] Wherein, L1R1 is the radius of curvature of the object side surface of the first lens; CT23 is the thickness of the first lens on the optical axis; CT56 is the thickness of the second lens on the optical axis; CT78 is the thickness of the third lens on the optical axis; and CT67 is the distance on the optical axis between the image side surface of the second lens and the object side surface of the third lens.

[0027] As an optional implementation, the optical imaging system satisfies the following relationship:

[0028] |EA2-EA3|≤90;

[0029] Wherein, EA2 is the second-order binary surface coefficient of the binary surface; EA3 is the third-order binary surface coefficient of the binary surface.

[0030] As an optional implementation, the optical imaging system satisfies the following relationship:

[0031] 0.1≤S6≤0.2 and -0.15≤S7≤-0.03;

[0032] -4≤S9+S10+S11+S12+S13+S14≤-3;

[0033] Wherein, S6 is the sagitta of the image-side surface of the second lens; S7 is the sagitta of the object-side surface of the third lens; S9 is the sagitta of the object-side surface of the fourth lens; S10 is the sagitta of the image-side surface of the fourth lens; S11 is the sagitta of the object-side surface of the fifth lens; S12 is the sagitta of the image-side surface of the fifth lens; S13 is the sagitta of the object-side surface of the sixth lens; and S14 is the sagitta of the image-side surface of the sixth lens.

[0034] Secondly, this application provides a camera module, the camera module including an image sensor and an optical imaging system as described in any of the first aspects, the image sensor being disposed on the image side of the optical imaging system.

[0035] Thirdly, this application provides an electronic device, the electronic device including a housing and a camera module as described in the second aspect, the camera module being disposed within the housing.

[0036] One or more technical solutions in the embodiments of the present invention have at least the following technical effects or advantages:

[0037] In this embodiment of the invention, the optical imaging system includes: a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a filter arranged sequentially along the optical axis from the object side to the image side; the object side surface of the first lens is convex, and the object side surfaces of the second to sixth lenses are all concave. This embodiment, through the convex and concave design of the object side surfaces of each lens within the optical system, utilizes the refraction effect of the lenses to correct distortion, dispersion, and field curvature as the incident light passes through the object side surface of the first lens to magnify the image, and then, during the process of passing through the second to sixth lenses, improves the image quality by correcting distortion, dispersion, and field curvature.

[0038] As incident light passes through each lens sequentially from the object side to the image side, chromatic aberration occurs due to lens refraction. Therefore, one optical surface of the filter is configured as a binary surface. The incident light passes sequentially through the first lens to the sixth lens, is refracted by the binary surface, and then exits onto the imaging surface adjacent to the image side of the filter. By setting the binary surface on the filter adjacent to the imaging surface, the chromatic aberration caused by all lenses on the object side of the binary surface is corrected using the refraction and diffraction effect of the binary surface. This eliminates the need to increase the number of lenses to correct the chromatic aberration caused by the first to sixth lenses, thereby increasing the aperture of the lens module and shortening the overall optical length.

[0039] Finally, this embodiment sets up an optical imaging system such that it satisfies the relationship TTL / ImgH×FOV= Or, TTL / ImgH×FOV= Where TTL is the total length of the optical imaging system; ImgH is the image height of the optical imaging system; and FOV is the field of view of the optical imaging system. This embodiment achieves a larger image height and field of view while further shortening the total optical length by balancing the total optical length, image height, and field of view.

[0040] The optical system provided in this embodiment achieves the technical effect of improving the imaging quality of the lens module while meeting the requirements for simplified and thinner lens module design. Attached image description:

[0041] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0042] Figure 1 A schematic diagram of the optical imaging system structure of Embodiment 1 of the present invention is shown;

[0043] Figure 2 The polychromatic light diffraction MTF diagram of the optical imaging system of Embodiment 1 of the present invention is shown;

[0044] Figure 3 The field curvature / distortion curve of the optical imaging system of Embodiment 1 of the present invention is shown;

[0045] Figure 4 An axial aberration curve of the optical imaging system of Embodiment 1 of the present invention is shown;

[0046] Figure 5 An image plane dot diagram of the optical imaging system of Embodiment 1 of the present invention is shown;

[0047] Figure 6 The diagram shows the chromatic aberration curve of the optical imaging system according to Embodiment 1 of the present invention;

[0048] Figure 7 A schematic diagram of the optical imaging system structure of Embodiment 2 of the present invention is shown;

[0049] Figure 8 The polychromatic light diffraction MTF diagram of the optical imaging system of Embodiment 2 of the present invention is shown;

[0050] Figure 9 The field curvature / distortion curve of the optical imaging system of Embodiment 2 of the present invention is shown;

[0051] Figure 10 The axial aberration curve of the optical imaging system of Embodiment 2 of the present invention is shown;

[0052] Figure 11 An image plane dot diagram of the optical imaging system of Embodiment 2 of the present invention is shown;

[0053] Figure 12 The diagram shows the chromatic aberration curve of the optical imaging system according to Embodiment 2 of the present invention;

[0054] Figure 13 A schematic diagram of the optical imaging system structure of Embodiment 3 of the present invention is shown;

[0055] Figure 14 The polychromatic light diffraction MTF diagram of the optical imaging system of Embodiment 3 of the present invention is shown;

[0056] Figure 15 The field curvature / distortion curve of the optical imaging system of Embodiment 3 of the present invention is shown;

[0057] Figure 16 The axial aberration curve of the optical imaging system of Embodiment 3 of the present invention is shown;

[0058] Figure 17 An image plane point diagram of the optical imaging system of Embodiment 3 of the present invention is shown;

[0059] Figure 18 The diagram shows the chromatic aberration curve of the optical imaging system according to Embodiment 3 of the present invention;

[0060] Figure 19 A schematic diagram of the camera module of Embodiment 4 of the present invention is shown;

[0061] Figure 20 A schematic diagram of the structure of the electronic device according to Embodiment 5 of the present invention is shown. Detailed Implementation

[0062] To facilitate understanding of this application, a more complete description will be provided below with reference to the accompanying drawings. Preferred embodiments of this application are shown in the drawings. However, this application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the disclosure of this application.

[0063] It should be noted that when an element is referred to as being "fixed to" another element, it can be directly attached to the other element or there may be an intervening element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "inner," "outer," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0064] 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 herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0065] This addresses the technical challenge of improving the imaging quality of the lens module while simultaneously meeting the requirements for simplified and thinner lens module design.

[0066] In one aspect, this application provides an optical imaging system, please refer to the appendix. Figure 1 The optical system has an object plane Q1 and an imaging plane Q17 on its two sides. The optical imaging system includes a first lens L1, an aperture Q4, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6 and a filter arranged sequentially along the optical axis from the object side to the image side. The image side of the filter is a binary surface.

[0067] As an optional implementation, in this embodiment, the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, and the sixth lens L6 are all aspherical mirrors. By adjusting the aspherical order of each lens, the surface complexity of the lens can be reduced, thereby improving the lens's aberration correction capability for edge field of view rays and the relative illumination of the edge field of view, thus improving the imaging quality of the optical imaging system.

[0068] As an optional implementation, the lens in this embodiment can be made of resin material to achieve the thinness of the optical imaging system while making it easier to process the complex surface shape of the lens; the lens and filter in this embodiment can be made of glass material to achieve good optical effect of the optical imaging system while reducing the sensitivity of the optical imaging system to temperature. The specific implementation method is selected according to the actual situation and is not limited here.

[0069] As an optional implementation, an aperture stop Q4 is provided between the first lens L1 and the second lens L2 in this embodiment. This prevents some of the light rays converged by the first lens L1 from directly entering the imaging surface without passing through the second lens L2 to the sixth lens L6, thus avoiding ghosting and improving image quality. The aperture stop Q4 can be an aperture stop or a field stop, depending on the specific implementation, and is not limited here.

[0070] The incident light reflected from the object plane Q1 passes sequentially through the object-side surface Q2 and image-side surface Q3 of the first lens L1, the aperture Q4, the object-side surface Q5 and image-side surface Q6 of the second lens L2, the object-side surface Q7 and image-side surface Q8 of the third lens L3, the object-side surface Q9 and image-side surface Q10 of the fourth lens L4, the object-side surface Q11 and image-side surface Q12 of the fifth lens L5, the object-side surface Q13 and image-side surface Q14 of the sixth lens L6, and the object-side surface Q15 of the filter. After being refracted by the binary surface Q16, it exits onto the imaging surface Q17 adjacent to the binary surface Q16.

[0071] Among them, the object-side surface Q2 of the first lens L1 is convex, the object-side surface Q5 of the second lens L2 is concave, the object-side surface Q7 of the third lens L3 is concave, the object-side surface Q9 of the fourth lens L4 is concave, the object-side surface Q11 of the fifth lens L5 is concave, and the object-side surface Q13 of the sixth lens L6 is concave.

[0072] This embodiment improves imaging quality by designing the convex and concave sides of each lens in the optical system and utilizing the refraction effect of the lenses. The first lens L1 converges the incident light, and the second lens L2 to the sixth lens L6 correct the distortion, dispersion and field curvature of the incident light.

[0073] As incident light passes through each lens sequentially from the object side to the image side, chromatic aberration occurs due to lens refraction. Therefore, the image side of the filter is configured as a binary surface Q16. By placing the binary surface Q16 on the filter P adjacent to the imaging surface Q17, the refraction and diffraction of the incident light by the binary surface Q16 corrects the chromatic aberration of all lenses located on the object side of the binary surface Q16, namely, the first lens L1 to the sixth lens L6. This eliminates the need to increase the number of lenses to correct the chromatic aberration caused by the first lens L1 to the sixth lens L6, thereby increasing the aperture of the lens module and shortening the overall optical length.

[0074] It should be noted that, in the actual setup of this optical imaging system, the object side of the filter can also be set as a binary surface, and this is not limited here.

[0075] The optical imaging system satisfies the following relationship:

[0076] TTL / ImgH×FOV= Or, TTL / ImgH×FOV= ;

[0077] Where TTL is the total length of the optical imaging system; ImgH is the image height of the optical imaging system, which is equal to the radius of the imaging circle; and FOV is the field of view of the optical imaging system.

[0078] This embodiment balances the total optical length, image height, and field of view, further shortening the total optical length while collecting incident light at a large angle, thereby increasing the image height and field of view.

[0079] The optical system provided in this embodiment achieves the technical effect of improving the imaging quality of the lens module while meeting the requirements for simplified and thinner lens module design.

[0080] As an optional implementation, the optical imaging system satisfies the following relationship:

[0081] 25≤|V2-V3|≤33.5;

[0082] Wherein, V2 is the Abbe number of the second lens L2; ​​V3 is the Abbe number of the third lens L3.

[0083] The Abbe number, also known as the dispersion coefficient, is used to measure the degree of light dispersion in a transparent medium. Results from numerous optical experiments show that the chromatic aberration of the optical system is minimized when the Abbe number V2 of the second lens L2 and the Abbe number V3 of the third lens L3 satisfy the following relationship: 25 ≤ |V2 - V3| ≤ 33.5. Therefore, the chromatic aberration of the optical imaging system can be corrected by controlling the difference between the Abbe number V2 of the second lens L2 and the third lens L3 to be between 25 and 33.5.

[0084] As an optional implementation, the optical imaging system satisfies the following relationship:

[0085] |N2-N3|≥0.1;

[0086] Wherein, N2 is the refractive index of the second lens, and N3 is the refractive index of the third lens.

[0087] The results of multiple optical experiments show that when the refractive indices N2 and N3 of the second lens satisfy the following relationship: |N2-N3|≥0.1, a certain height difference will be formed between the light apertures passing through the second lens and the light apertures passing through the third lens. This height difference is beneficial for field curvature correction of the optical imaging system. Therefore, controlling the difference between the refractive indices N2 and N3 of the second lens to be greater than 0.1 is used to correct the field curvature of the optical imaging system.

[0088] As an optional implementation, the optical imaging system satisfies the following relationship:

[0089] 0.75≤f1 / f≤0.95;

[0090] 0.2≤f2 / f6≤0.5;

[0091] 1.0≤|f4 / f5|≤3.5;

[0092] -50≤f2+f3+f4+f5+f6≤-10;

[0093] Wherein, f is the effective focal length of the optical imaging system; f1 is the focal length of the first lens; f2 is the focal length of the second lens; f3 is the focal length of the third lens; f4 is the focal length of the fourth lens; f5 is the focal length of the fifth lens; and f6 is the focal length of the sixth lens.

[0094] Since most of the incident light converges through the first lens L1, which is closest to the object surface, the ratio of the focal length f1 of the first lens L1 to the effective focal length f of the optical imaging system should not be too large. Results from multiple optical experiments show that satisfying the following relationship—0.75 ≤ f1 / f ≤ 0.95—effectively reduces the optical power of the second lens L2 to the sixth lens L6, thus facilitating aberration correction. Therefore, the ratio of the focal length f1 of the first lens L1 to the effective focal length f of the optical imaging system should be controlled between 0.75 and 0.95.

[0095] The incident light, converged by the first lens L1, enters the second lens L2 and exits through the sixth lens L6. Therefore, controlling the difference between the focal length f2 of the second lens L2 and the focal length f6 of the sixth lens L6 within a certain range can make the light passing through the lens group smoother, thereby reducing primary aberrations and facilitating overall aberration correction. Results from multiple optical experiments show that the optical imaging system produces the smallest aberrations when the following relationship is satisfied: 0.2 ≤ f2 / f6 ≤ 0.5. Therefore, the ratio of the focal length f2 of the second lens L2 to the focal length f6 of the sixth lens L6 should be controlled between 0.2 and 0.5.

[0096] To ensure smooth light transmission within the lens group, the difference between the fourth lens L4 and the fifth lens L5 in the middle of the lens group should not be too large. However, if the difference between the fourth lens L4 and the fifth lens L5 in the middle of the lens group is too small, the height difference between the light apertures passing through the fourth lens and the light apertures passing through the fifth lens will be too small, which is not conducive to field curvature correction of the optical imaging system. Results from multiple optical experiments show that when the following relationship is satisfied: 1.0 ≤ |f4 / f5| ≤ 3.5, the height difference between the light apertures of the fourth lens L4 and the light apertures passing through the fifth lens L5 can be used for field curvature correction of the optical imaging system, and at this time, the aberrations produced by the optical imaging system are minimized. Therefore, the ratio of the focal length f4 of the fourth lens L4 to the focal length f5 of the fifth lens L5 should be controlled between 1.0 and 3.5.

[0097] Since the object-side surface Q5 of the second lens L2 is concave, the object-side surface Q7 of the third lens L3 is concave, the object-side surface Q9 of the fourth lens L4 is concave, the object-side surface Q11 of the fifth lens L5 is concave, and the object-side surface Q13 of the sixth lens L6 is concave, controlling the negative optical power of the second lens L2 to the sixth lens L6 can make the lenses smoother, reduce the sensitivity of the optical system, and improve the manufacturing yield. Results from multiple optical experiments show that when the following relationship is satisfied—-50≤f2+f3+f4+f5+f6≤-10—controlling the light deflection angle within a certain range using the second lens L2 to the sixth lens L6 is most beneficial for correcting spherical aberration and coma. Therefore, controlling the sum of the focal lengths f2 of the second lens L2, f3 of the third lens L3, f3 of the fourth lens L4, f5 of the fifth lens L5, and f6 of the sixth lens L6 to be between -10 and -50 is optimal.

[0098] As an optional implementation, the optical imaging system satisfies the following relationship:

[0099] 0.25≤CT23 / L1R1≤0.45;

[0100] 0.4≤(CT56+CT78) / CT67≤0.6;

[0101] Wherein, L1R1 is the radius of curvature of the object side surface of the first lens; CT23 is the thickness of the first lens on the optical axis; CT56 is the thickness of the second lens on the optical axis; CT78 is the thickness of the third lens on the optical axis; and CT67 is the distance on the optical axis between the image side surface of the second lens and the object side surface of the third lens.

[0102] Since the first lens L1 acts as a convergent lens for incident light, if the ratio of the thickness CT23 of the first lens L1 to the radius of curvature L1R1 of its object side is too large, the converging effect of the incident light will be reduced. In addition, if the lens is too thick, it will also lead to processing difficulties and increase the weight of the lens module. Based on the experimental results of multiple optical experiments, the ratio of the thickness CT23 of the first lens L1 to the radius of curvature L1R1 of its object side is controlled between 0.25 and 0.45.

[0103] This application performs field curvature correction by setting the parameters of the second lens L2 and the third lens L3.

[0104] Based on the results of multiple optical experiments, by setting the thickness CT56 of the second lens L2, the thickness CT78 of the third lens L3, and the distance CT67 between the second lens L2 and the third lens L3, the following relationship is satisfied: 0.4≤(CT56+CT78) / CT67≤0.6, the field curvature of the optical imaging system is minimized, while also meeting the requirements of actual processing and assembly.

[0105] As an optional implementation, the optical imaging system satisfies the following relationship:

[0106] |EA2-EA3|≤90;

[0107] Wherein, EA2 is the second-order binary surface coefficient of the binary surface; EA3 is the third-order binary surface coefficient of the binary surface.

[0108] The difference between the second-order and third-order binary surface coefficients of the binary surface is less than a certain value, resulting in a sufficiently large annular band width, which is beneficial for machining the binary surface on the filter P. Experimental results from multiple optical experiments show that controlling the difference between the second-order and third-order binary surface coefficients to be less than 90 facilitates machining the binary surface on the filter P and also achieves a sufficiently large annular band width. Therefore, |EA2-EA3|≤90 should be controlled.

[0109] As an optional implementation, the optical imaging system satisfies the following relationship:

[0110] 0.1≤S6≤0.2 and -0.15≤S7≤-0.03;

[0111] -4≤S9+S10+S11+S12+S13+S14≤-3;

[0112] Wherein, S6 is the sagitta of the image-side surface Q6 of the second lens L2; ​​S7 is the sagitta of the object-side surface Q7 of the third lens L3; S9 ​​is the sagitta of the object-side surface Q9 of the fourth lens L4; S10 is the sagitta of the image-side surface Q10 of the fourth lens L4; S11 is the sagitta of the object-side surface Q11 of the fifth lens L5; S12 is the sagitta of the image-side surface Q12 of the fifth lens L5; S13 is the sagitta of the object-side surface Q13 of the sixth lens L6; and S14 is the sagitta of the image-side surface Q14 of the sixth lens L6.

[0113] As mentioned earlier, this embodiment corrects field curvature by setting the parameters of the second lens L2 and the third lens L3. Since the image-side surface Q6 of the second lens L2 is adjacent to the image-side surface Q7 of the third lens L3, when the image-side surface Q6 of the second lens L2 is positive and the object-side surface Q7 of the third lens L3 is negative, the positive and negative vector heights interlock, which is beneficial for correcting field curvature.

[0114] Experimental results from multiple optical experiments show that the best fit between positive and negative sags is achieved when the following relationships are satisfied: 0.1≤S6≤0.2 and -0.15≤S7≤-0.03, which is most beneficial for field curvature correction.

[0115] This embodiment corrects aberrations by setting the parameters of the fourth lens L4, the fifth lens L5, and the sixth lens L6. Experimental results from multiple optical experiments show that, for the object-side surface Q9 (saurus S9), image-side surface Q10 (saurus S10), object-side surface Q11 (saurus S11), image-side surface Q12 (saurus S12), object-side surface Q13 (saurus S13), and image-side surface Q14 (saurus S14) of the sixth lens L6, controlling the values ​​of sagittas S9, S10, S11, S12, S13, and S14 within a certain negative range allows for a smooth increase in the light aperture, reducing aberrations, meeting the image plane size requirements, and increasing relative illumination. When the following relationship is satisfied: -4 ≤ S9 + S10 + S11 + S12 + S13 + S14 ≤ -3, the light aperture is smoothly increased, the aberrations are minimized, and the relative illumination is maximized. Therefore, the sum of the control sags S9, S10, S11, S12, S13, and S14 is between -4 and -3.

[0116] Example 1

[0117] The optical imaging system provided in this application is as follows: Figure 1As shown, the optical imaging system includes: a first lens L1, an aperture Q4, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6, and a filter arranged sequentially along the optical axis from the object side to the image side. The image side of the filter is a binary surface. Incident light reflected from the object surface Q1 passes sequentially through the object side Q2 and image side Q3 of the first lens L1, the aperture Q4, the object side Q5 and image side Q6 of the second lens L2, the object side Q7 and image side Q8 of the third lens L3, the object side Q9 and image side Q10 of the fourth lens L4, the object side Q11 and image side Q12 of the fifth lens L5, the object side Q13 and image side Q14 of the sixth lens L6, and the object side Q15 of the filter. After being refracted by the binary surface Q16, it exits onto the imaging surface Q17 adjacent to the binary surface Q16.

[0118] Among them, the object-side surface Q2 of the first lens L1 is convex, the object-side surface Q5 of the second lens L2 is concave, the object-side surface Q7 of the third lens L3 is concave, the object-side surface Q9 of the fourth lens L4 is concave, the object-side surface Q11 of the fifth lens L5 is concave, and the object-side surface Q13 of the sixth lens L6 is concave.

[0119] Table 1 below lists the lens performance parameters for the corresponding optical imaging system:

[0120] Table 1:

[0121]

[0122] Table 2 below provides the bidimensional surface parameter data for an exemplary system:

[0123] Table 2:

[0124]

[0125] Table 3 below provides lens structure data for an exemplary optical imaging system:

[0126] Table 3:

[0127]

[0128] As attached Figure 2 The diagram shows the polychromatic light diffraction MTF of an optical imaging system with the aforementioned lens structure data and performance parameters. This MTF represents the resolving power of the optical imaging system in the meridional and sagittal planes. The horizontal axis represents spatial frequency in mm, and the vertical axis represents contrast ratio. Solid lines represent the contrast ratio of the optical imaging system in the meridional plane, and dashed lines represent the contrast ratio in the sagittal plane; higher contrast ratios indicate better image quality. Figure 2As can be seen, the contrast ratio reaches over 40% within the spatial frequency range of 0-125mm, indicating high imaging quality.

[0129] As attached Figure 3 The figure shown is a field curvature / distortion curve of an optical imaging system with the above lens structure data and lens performance parameters, used to represent the field curvature and distortion of the optical imaging system across the entire field of view.

[0130] lie in Figure 3 In the field curve diagram on the left, the horizontal axis represents the field curvature value and the vertical axis represents the field angle. It can be seen from the figure that for the field angle in the range of 0-6.2, the field curvature value is less than 0.16mm.

[0131] lie in Figure 3 In the distortion curve graph on the right, the horizontal axis represents the percentage of distortion and the vertical axis represents the field of view. As can be seen from the graph, for the field of view within the range of 0-6.2, the percentage of distortion is less than 3.0.

[0132] Therefore, in this embodiment, the field curvature and distortion of the optical imaging system are well controlled, and the optical imaging system has high imaging quality.

[0133] As attached Figure 4 This is an axial aberration curve diagram for an optical imaging system with the aforementioned lens structure data and lens performance parameters, used to represent the axial aberration of the optical imaging lens. The horizontal axis represents axial aberration, and the vertical axis represents the normalized field of view. Figure 4 As can be seen, the axial aberration of the optical imaging system is controlled within the range of 0.15mm, resulting in high imaging quality.

[0134] As attached Figure 5 This is a point diagram of the image plane of an optical imaging system with the aforementioned lens structure data and lens performance parameters. Each point diagram represents the size of the light spot corresponding to the entire field of view on the image plane, used to intuitively understand the optical performance. Figure 5 As can be seen, the root mean square (RMS) value of the full field-of-view light spot of the optical imaging system is less than 1 μm, indicating that the optical imaging system has high imaging quality.

[0135] As attached Figure 6 This is a transverse chromatic aberration curve for an optical imaging system with the aforementioned lens structure data and performance parameters, used to represent the astigmatism of the optical imaging system. The horizontal axis represents focus shift, and the vertical axis represents paraxial image height, in mm. Solid lines represent the astigmatism curve of the meridional imaging plane, and dashed lines represent the astigmatism curve of the sagittal imaging plane. Figure 6 As can be seen from the above, the astigmatism of the optical imaging system in Example 1 is well compensated.

[0136] Test results show that the optical imaging system provided in Example 1 has a focal length of f=7mm, an aperture of f / 2.0, a field of view (FOV) of 82.6°, a total optical length (TTL) of 7.5mm, and an imaging circle diameter (D) of 12.3mm (i.e., a 1 / 1.3″ large target surface), with a TTL / D ratio of <0.6. In contrast, existing technologies require at least 7 lenses and a total optical length greater than 8mm to achieve the same target surface size and focal length. For example, in utility model patent CN_203965708_U, 7 lenses are needed, but the resulting image height is only 5.99mm, the aperture is only f / 2.6, the TTL is >9.8mm, and the TTL / D ratio is >0.8. This embodiment uses only 6 lenses and achieves good aberration correction, realizing a large target surface, short lens, and high pixel count. This achieves the technical effect of improving the imaging quality of the lens module while meeting the requirements for simplified and thinner lens module design.

[0137] Example 2

[0138] The optical imaging system provided in this application is as follows: Figure 7 As shown, the optical imaging system includes: a first lens L1, an aperture Q4, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6, and a filter arranged sequentially along the optical axis from the object side to the image side. The image side of the filter is a binary surface. Incident light reflected from the object surface Q1 passes sequentially through the object side Q2 and image side Q3 of the first lens L1, the aperture Q4, the object side Q5 and image side Q6 of the second lens L2, the object side Q7 and image side Q8 of the third lens L3, the object side Q9 and image side Q10 of the fourth lens L4, the object side Q11 and image side Q12 of the fifth lens L5, the object side Q13 and image side Q14 of the sixth lens L6, and the object side Q15 of the filter. After being refracted by the binary surface Q16, it exits onto the imaging surface Q17 adjacent to the binary surface Q16.

[0139] Among them, the object-side surface Q2 of the first lens L1 is convex, the object-side surface Q5 of the second lens L2 is concave, the object-side surface Q7 of the third lens L3 is concave, the object-side surface Q9 of the fourth lens L4 is concave, the object-side surface Q11 of the fifth lens L5 is concave, and the object-side surface Q13 of the sixth lens L6 is concave.

[0140] Table 4 below provides the lens performance parameters for the corresponding optical imaging system:

[0141] Table 4:

[0142]

[0143] Table 5 below provides the bidimensional surface parameter data for an exemplary system:

[0144] Table 5:

[0145] Table 6 below provides lens structure data for an exemplary optical imaging system:

[0146] Table 6:

[0147]

[0148] As attached Figure 8 The diagram shows the polychromatic light diffraction MTF of an optical imaging system with the aforementioned lens structure data and performance parameters. This MTF represents the resolving power of the optical imaging system in the meridional and sagittal planes. The horizontal axis represents spatial frequency in mm, and the vertical axis represents contrast ratio. Solid lines represent the contrast ratio of the optical imaging system in the meridional plane, and dashed lines represent the contrast ratio in the sagittal plane; higher contrast ratios indicate better image quality. Figure 8 As can be seen, the contrast ratio reaches over 46% within the spatial frequency range of 0-125mm, indicating high imaging quality.

[0149] As attached Figure 9 The figure shown is a field curvature / distortion curve of an optical imaging system with the above lens structure data and lens performance parameters, used to represent the field curvature and distortion of the optical imaging system across the entire field of view.

[0150] lie in Figure 9 In the field curve diagram on the left, the horizontal axis represents the field curvature value and the vertical axis represents the field angle. It can be seen from the figure that for the field angle in the range of 0-6.2, the field curvature value is less than 0.14mm.

[0151] lie in Figure 9 In the distortion curve graph on the right, the horizontal axis represents the percentage of distortion and the vertical axis represents the field of view. As can be seen from the graph, for the field of view within the range of 0-6.2, the percentage of distortion is less than 2.5.

[0152] Therefore, in this embodiment, the field curvature and distortion of the optical imaging system are well controlled, and the optical imaging system has high imaging quality.

[0153] As attached Figure 10 This is an axial aberration curve diagram for an optical imaging system with the aforementioned lens structure data and lens performance parameters, used to represent the axial aberration of the optical imaging lens. The horizontal axis represents axial aberration, and the vertical axis represents the normalized field of view. Figure 10 As can be seen, the axial aberration of the optical imaging system is controlled within the range of 0.14mm, resulting in high imaging quality.

[0154] As attached Figure 11This is a point diagram of the image plane of an optical imaging system with the aforementioned lens structure data and lens performance parameters. Each point diagram represents the size of the light spot corresponding to the entire field of view on the image plane, used to intuitively understand the optical performance. Figure 11 As can be seen, the root mean square (RMS) value of the full field-of-view light spot of the optical imaging system is less than 1 μm, indicating that the optical imaging system has high imaging quality.

[0155] As attached Figure 12 This is a transverse chromatic aberration curve for an optical imaging system with the aforementioned lens structure data and performance parameters, used to represent the astigmatism of the optical imaging system. The horizontal axis represents focus shift, and the vertical axis represents paraxial image height, in mm. Solid lines represent the astigmatism curve of the meridional imaging plane, and dashed lines represent the astigmatism curve of the sagittal imaging plane. Figure 12 As can be seen from the above, the astigmatism of the optical imaging system in Example 2 is well compensated.

[0156] Test results show that the optical imaging system provided in Example 2 has a focal length of f=7mm, an aperture of f / 2.0, a field of view (FOV) of 82.6°, a total optical length (TTL) of 7.5mm, and an imaging circle diameter (D) of 12.3mm (i.e., a 1 / 1.3″ large target surface), with a TTL / D ratio of <0.6. In contrast, existing technologies require at least 7 lenses to achieve the same target surface size and focal length, resulting in a total optical length greater than 8mm. For example, in utility model patent CN_203965708_U, 7 lenses are needed, but the resulting image height is only 5.99mm, the aperture is only f / 2.6, the TTL is >9.8mm, and the TTL / D ratio is >0.8. This embodiment uses only 6 lenses and achieves good aberration correction, realizing a large target surface, short lens, and high pixel count. This achieves the technical effect of improving the imaging quality of the lens module while meeting the requirements for simplified and thinner lens module design.

[0157] Example 3

[0158] The optical imaging system provided in this application is as follows: Figure 13As shown, the optical imaging system includes: a first lens L1, an aperture Q4, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6, and a filter arranged sequentially along the optical axis from the object side to the image side. The image side of the filter is a binary surface. Incident light reflected from the object surface Q1 passes sequentially through the object side Q2 and image side Q3 of the first lens L1, the aperture Q4, the object side Q5 and image side Q6 of the second lens L2, the object side Q7 and image side Q8 of the third lens L3, the object side Q9 and image side Q10 of the fourth lens L4, the object side Q11 and image side Q12 of the fifth lens L5, the object side Q13 and image side Q14 of the sixth lens L6, and the object side Q15 of the filter. After being refracted by the binary surface Q16, it exits onto the imaging surface Q17 adjacent to the binary surface Q16.

[0159] Among them, the object-side surface Q2 of the first lens L1 is convex, the object-side surface Q5 of the second lens L2 is concave, the object-side surface Q7 of the third lens L3 is concave, the object-side surface Q9 of the fourth lens L4 is concave, the object-side surface Q11 of the fifth lens L5 is concave, and the object-side surface Q13 of the sixth lens L6 is concave.

[0160] Table 1 below lists the lens performance parameters for the corresponding optical imaging system:

[0161] Table 7:

[0162]

[0163] Table 8 below provides the bidimensional surface parameter data for an exemplary system:

[0164] Table 8:

[0165]

[0166] Table 9 below provides lens structure data for an exemplary optical imaging system:

[0167] Table 9:

[0168] As attached Figure 14 The diagram shows the polychromatic light diffraction MTF of an optical imaging system with the aforementioned lens structure data and performance parameters. This MTF represents the resolving power of the optical imaging system in the meridional and sagittal planes. The horizontal axis represents spatial frequency in mm, and the vertical axis represents contrast ratio. Solid lines represent the contrast ratio of the optical imaging system in the meridional plane, and dashed lines represent the contrast ratio in the sagittal plane; higher contrast ratios indicate better image quality. Figure 14 As can be seen, the contrast ratio reaches over 40% within the spatial frequency range of 0-125mm, indicating high imaging quality.

[0169] As attached Figure 15 The figure shown is a field curvature / distortion curve of an optical imaging system with the above lens structure data and lens performance parameters, used to represent the field curvature and distortion of the optical imaging system across the entire field of view.

[0170] lie in Figure 15 In the field curve diagram on the left, the horizontal axis represents the field curvature value and the vertical axis represents the field angle. It can be seen from the figure that for the field angle in the range of 0-6.2, the field curvature value is less than 0.05mm.

[0171] lie in Figure 15 In the distortion curve graph on the right, the horizontal axis represents the percentage of distortion and the vertical axis represents the field of view. As can be seen from the graph, for the field of view within the range of 0-6.2, the percentage of distortion is less than 2.5.

[0172] Therefore, in this embodiment, the field curvature and distortion of the optical imaging system are well controlled, and the optical imaging system has high imaging quality.

[0173] As attached Figure 16 This is an axial aberration curve diagram for an optical imaging system with the aforementioned lens structure data and lens performance parameters, used to represent the axial aberration of the optical imaging lens. The horizontal axis represents axial aberration, and the vertical axis represents the normalized field of view. Figure 16 As can be seen, the axial aberration of the optical imaging system is controlled within the range of 0.22mm, resulting in high imaging quality.

[0174] As attached Figure 17 This is a point diagram of the image plane of an optical imaging system with the aforementioned lens structure data and lens performance parameters. Each point diagram represents the size of the light spot corresponding to the entire field of view on the image plane, used to intuitively understand the optical performance. Figure 17 As can be seen, the root mean square (RMS) value of the full field-of-view light spot of the optical imaging system is less than 1 μm, indicating that the optical imaging system has high imaging quality.

[0175] As attached Figure 18 This is a transverse chromatic aberration curve for an optical imaging system with the aforementioned lens structure data and performance parameters, used to represent the astigmatism of the optical imaging system. The horizontal axis represents focus shift, and the vertical axis represents paraxial image height, in mm. Solid lines represent the astigmatism curve of the meridional imaging plane, and dashed lines represent the astigmatism curve of the sagittal imaging plane. Figure 18 As can be seen from the above, the astigmatism of the optical imaging system in Example 3 is well compensated.

[0176] Test results show that the optical imaging system provided in Example 3 has a focal length f=6.5mm, aperture f2.0, field of view FOV=86.8°, total optical length TTL=7.5mm, imaging circle diameter D=12.3mm (i.e., a 1 / 1.3″ large target surface), and TTL / D<0.6. Compared to existing technologies that require at least 7 lenses and a total optical length greater than 8mm to achieve the same target surface size and focal length (e.g., utility model patent CN_203965708_U requires 7 lenses, but only achieves an image height of 5.99mm, an aperture of only f2.6, TTL>9.8mm, and TTL / D>0.8), this example uses only 6 lenses and achieves good aberration correction, realizing a large target surface, short lens, and high pixel count. This achieves the technical effect of improving the imaging quality of the lens module while meeting the requirements for simplified and thinner lens module design.

[0177] Example 4

[0178] This application also discloses a camera module, as shown in the attached image. Figure 19 As shown, the camera module 200 includes an image sensor 201 and an optical lens 100 as described in any of embodiments 1 to 3 above. The image sensor 201 is disposed on the image side of the optical lens 100. The optical lens 100 can be used to receive the light signal of the subject and project it onto the image sensor 201, and the image sensor 201 can be used to convert the light signal corresponding to the subject into an image signal. Further details are omitted here. It is understood that the camera module 200 with the aforementioned optical lens 100 can improve the imaging quality of the lens module while meeting the requirements for simplified and thinner lens module design. Since the above technical effects have been described in detail in the embodiments of the optical lens 100, they will not be repeated here.

[0179] Example 5

[0180] This application also discloses an electronic device, as shown in the attached document. Figure 20 As shown, the electronic device 300 includes a housing 300 and a camera module 200 as described above. The camera module 200 is disposed on the housing 301 to acquire image information. The electronic device 300 can be, but is not limited to, a mobile phone, tablet computer, laptop computer, smartwatch, monitor, etc. It is understood that the electronic device 300 with the aforementioned camera module 200 also possesses all the technical effects of the aforementioned optical lens 100. That is, the electronic device 300 can enable the optical lens 100 to improve the imaging quality of the lens module while meeting the requirements for simplified and thinner lens module design. Since the above technical effects have been described in detail in the embodiments of the optical lens 100, they will not be repeated here.

[0181] The above descriptions are merely embodiments of this application. Commonly known structures and characteristics of the solutions are not described in detail here. Those skilled in the art are aware of all common technical knowledge in the field prior to the application date or priority date, are aware of all existing technologies in that field, and have the ability to apply conventional experimental methods prior to that date. Those skilled in the art can, based on the guidance provided in this application, improve and implement this solution in combination with their own capabilities. Some typical known structures or methods should not be obstacles for those skilled in the art to implement this application. It should be noted that those skilled in the art can make several modifications and improvements without departing from the structure of this application. These should also be considered within the scope of protection of this application, and will not affect the effectiveness of the implementation of this application or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. An optical imaging system, characterized in that, The optical imaging system includes: a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a filter arranged sequentially along the optical axis from the object side to the image side; wherein, the optical imaging system has 6 lenses with optical power; the first lens has positive optical power, the second lens has negative optical power, the third lens has positive optical power, the fourth lens has negative optical power, the fifth lens has positive optical power, and the sixth lens has negative optical power; The object-side surface of the first lens is convex, while the object-side surfaces of the second to sixth lenses are all concave. One optical surface of the filter is a binary surface; the incident light passes through the first lens to the sixth lens in sequence, is refracted by the binary surface, and then exits onto the imaging surface adjacent to the image side of the filter. The optical imaging system satisfies the following relationship: TTL / ImgH×FOV= Or, TTL / ImgH×FOV= ; And 0.2≤f2 / f6≤0.5; Wherein, TTL is the total length of the optical imaging system; ImgH is the image height of the optical imaging system; FOV is the field of view of the optical imaging system; f2 is the focal length of the second lens; and f6 is the focal length of the sixth lens.

2. The optical imaging system as described in claim 1, characterized in that, The optical imaging system satisfies the following relationship: 25≤|V2-V3|≤33.5; Wherein, V2 is the Abbe number of the second lens; V3 is the Abbe number of the third lens.

3. The optical imaging system as described in claim 1, characterized in that, The optical imaging system satisfies the following relationship: |N2-N3|≥0.1; Wherein, N2 is the refractive index of the second lens, and N3 is the refractive index of the third lens.

4. The optical imaging system as described in claim 1, characterized in that, The optical imaging system satisfies the following relationship: 0.75≤f1 / f≤0.95; 1.0≤|f4 / f5|≤3.5; -50mm≤f2+f3+f4+f5+f6≤-10mm; Wherein, f is the effective focal length of the optical imaging system; f1 is the focal length of the first lens; f2 is the focal length of the second lens; f3 is the focal length of the third lens; f4 is the focal length of the fourth lens; f5 is the focal length of the fifth lens; and f6 is the focal length of the sixth lens.

5. An optical imaging system as described in claim 1, characterized in that, The optical imaging system satisfies the following relationship: 0.25≤CT23 / L1R1≤0.45; 0.4≤(CT56+CT78) / CT67≤0.6, Wherein, L1R1 is the radius of curvature of the object side surface of the first lens; CT23 is the thickness of the first lens on the optical axis; CT56 is the thickness of the second lens on the optical axis; CT78 is the thickness of the third lens on the optical axis; and CT67 is the distance on the optical axis between the image side surface of the second lens and the object side surface of the third lens.

6. An optical imaging system as described in claim 1, characterized in that, The optical imaging system satisfies the following relationship: |EA2-EA3|≤90; Wherein, EA2 is the second-order binary surface coefficient of the binary surface; EA3 is the third-order binary surface coefficient of the binary surface.

7. An optical imaging system as described in claim 1, characterized in that, The optical imaging system satisfies the following relationship: 0.1mm≤S6≤0.2mm and -0.15mm≤S7≤-0.03mm; -4mm≤S9+S10+S11+S12+S13+S14≤-3mm; Wherein, S6 is the sagitta of the image-side surface of the second lens; S7 is the sagitta of the object-side surface of the third lens; S9 is the sagitta of the object-side surface of the fourth lens; S10 is the sagitta of the image-side surface of the fourth lens; S11 is the sagitta of the object-side surface of the fifth lens; S12 is the sagitta of the image-side surface of the fifth lens; S13 is the sagitta of the object-side surface of the sixth lens; and S14 is the sagitta of the image-side surface of the sixth lens.

8. An optical imaging system as described in claim 1, characterized in that, An aperture stop is provided between the first lens and the second lens.

9. A camera module, characterized in that: The camera module includes an image sensor and an optical imaging system as described in any one of claims 1-8, wherein the image sensor is disposed on the image side of the optical imaging system.

10. An electronic device, characterized in that, The electronic device includes a housing and a camera module as described in claim 9, wherein the camera module is disposed within the housing.

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