Optical system

Abstract

This invention relates to an optical system, comprising at least a lens barrel, a first to an eighth lens having optical power disposed within the lens barrel, and a first and a second spacer element; the optical system satisfies: 1.80≤R3 / R4*V2≤3.03; 14.81≤f2 / T12≤16.07; 1.33≤(D2s-d2s) / EP12≤3.09; wherein, R3 and R4 are the radii of curvature of the object-side and image-side surfaces of the second lens, respectively, V2 is the Abbe number of the second lens, f2 is the effective focal length of the second lens, T12 is the air gap between the first and second lenses on the optical axis, D2s and d2s are the outer and inner diameters of the object-side surface of the second spacer element, respectively, and EP12 is the distance between the image-side surface of the first spacer element and the object-side surface of the second spacer element along the optical axis. The optical system of the present invention ensures that the channel width and the spacing distance match when light passes through the second spacer element, and effectively intercepts stray light from the edges, so that the light propagates to the subsequent optical elements at a uniform and reasonable angle, reducing light scattering and interference, and improving the clarity of the image.

Description

Technical Field

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

[0002] Driven by a combination of factors, including market demand, technological innovation, and industry competition, mobile phones have gradually replaced traditional cameras. Their portability and multifunctionality have made them the mainstream photography tool. In terms of technological innovation, the rapid development of the mobile phone industry has provided a powerful impetus for the innovation of lens technology. In recent years, mobile phones have made significant progress in hardware performance and image processing algorithms. For example, mobile phone manufacturers have continuously developed high-pixel sensors, improving the ability of mobile phone lenses to capture details; at the same time, advanced image processing algorithms can optimize captured photos, enhancing the color, contrast, and clarity of the image.

[0003] With ever-increasing demands for image quality, the design and manufacture of optical systems face numerous challenges. This is especially true in eight-lens optical systems, where low-dispersion lenses are employed to correct aberrations and chromatic aberration in order to achieve higher imaging results. However, low-dispersion lenses can also cause significant stray light to be generated during transmission, affecting image sharpness and leading to blurred images. Summary of the Invention

[0004] To address the problems existing in the prior art, the present invention aims to provide an optical system that can effectively intercept stray light at the lens edge using a spacer element, thereby improving the clarity of the image.

[0005] To achieve the above-mentioned objectives, the present invention provides an optical system comprising a lens barrel, an imaging lens group housed within the lens barrel, and a plurality of spacer elements.

[0006] The imaging lens group comprises, sequentially from the object side to the image side along the optical axis: a first lens with positive optical power, a second lens with positive optical power, a third lens with optical power, a fourth lens with optical power, a fifth lens with optical power, a sixth lens with optical power, a seventh lens with optical power, and an eighth lens with negative optical power, totaling eight lenses with optical power; the object side of the first lens is convex and the image side is concave; the object side of the second lens is convex and the image side is concave; both the object side and the image side of the eighth lens are concave.

[0007] The plurality of spacers include a first spacer located between the first lens and the second lens and at least partially abutting the image side of the first lens, and a second spacer located between the second lens and the third lens and at least partially abutting the image side of the second lens;

[0008] The optical system satisfies:

[0009] 1.80≤R3 / R4*V2≤3.03; 14.81≤f2 / T12≤16.07;

[0010] 1.33≤(D2s-d2s) / EP12≤3.09;

[0011] Wherein, R3 is the radius of curvature of the object side of the second lens, R4 is the radius of curvature of the image side of the second lens, V2 is the Abbe number of the second lens, f2 is the effective focal length of the second lens, T12 is the air gap between the first lens and the second lens on the optical axis, D2s is the outer diameter of the object side of the second spacer element, d2s is the inner diameter of the object side of the second spacer element, and EP12 is the distance between the image side of the first spacer element and the object side of the second spacer element along the optical axis.

[0012] According to one technical solution of the present invention, the plurality of spacer elements further includes a third spacer element located between the third lens and the fourth lens and at least partially abutting the image side of the third lens;

[0013] The optical system satisfies: 1.97≤EP23 / (CT3+T23)≤2.89;

[0014] Wherein, EP23 is the distance between the image side of the second spacer element and the object side of the third spacer element along the optical axis, CT3 is the thickness of the third lens on the optical axis, and T23 is the air gap between the second lens and the third lens on the optical axis.

[0015] According to one technical solution of the present invention, the optical system satisfies: 11.23≤d3s / CT3≤13.12;

[0016] Wherein, d3s is the inner diameter of the object side of the third spacer element, and CT3 is the thickness of the third lens on the optical axis.

[0017] According to one technical solution of the present invention, the plurality of spacer elements further includes a fourth spacer element located between the fourth lens and the fifth lens and at least partially abutting the image side of the fourth lens, and a fifth spacer element located between the fifth lens and the sixth lens and at least partially abutting the image side of the fifth lens; the optical system satisfies: 1.78≤EP45 / CT5≤2.33;

[0018] Wherein, EP45 is the distance between the image side of the fourth spacer element and the object side of the fifth spacer element along the optical axis, and CT5 is the thickness of the fifth lens along the optical axis.

[0019] According to one technical solution of the present invention, the optical system satisfies: 3.33≤R10 / (D5s-d5s)≤4.50;

[0020] Wherein, R10 is the radius of curvature of the image side of the fifth lens, D5s is the outer diameter of the object side of the fifth spacer element, and d5s is the inner diameter of the object side of the fifth spacer element.

[0021] According to one technical solution of the present invention, the optical system satisfies: 4.23 ≤ R8 / d4s ≤ 5.21;

[0022] Wherein, R8 is the radius of curvature of the image side of the fourth lens, and d4s is the inner diameter of the object side of the fourth spacer element.

[0023] According to one technical solution of the present invention, the plurality of spacers further includes a seventh spacer located between the seventh lens and the eighth lens and at least partially abutting the image side of the seventh lens, and an eighth spacer located on the image side of the eighth lens and at least partially abutting the image side of the eighth lens;

[0024] The optical system satisfies: 2.42≤(D7m-d7m) / (D8s-d8s)≤3.68;

[0025] Wherein, D7m is the outer diameter of the image side of the seventh spacer element, d7m is the inner diameter of the image side of the seventh spacer element, D8s is the outer diameter of the object side of the eighth spacer element, and d8s is the inner diameter of the object side of the eighth spacer element.

[0026] According to one technical solution of the present invention, the plurality of spacer elements further includes a sixth spacer element located between the sixth lens and the seventh lens and at least partially abutting the image side of the sixth lens; the optical system satisfies: 1.70≤(d7s-d6m) / CT7≤2.53;

[0027] Wherein, d7s is the inner diameter of the object side of the seventh spacer element, d6m is the inner diameter of the image side of the sixth spacer element, and CT7 is the thickness of the seventh lens on the optical axis.

[0028] According to one technical solution of the present invention, the optical system satisfies: 0.87≤EP78 / EP67≤1.87;

[0029] Wherein, EP78 is the distance between the image side of the seventh spacer element and the object side of the eighth spacer element along the optical axis, and EP67 is the distance between the image side of the sixth spacer element and the object side of the seventh spacer element along the optical axis.

[0030] According to one technical solution of the present invention, the optical system satisfies: 2.03≤f6 / D6s≤3.92;

[0031] Where f6 is the effective focal length of the sixth lens, and D6s is the outer diameter of the object side of the sixth spacer element.

[0032] According to one technical solution of the present invention, the optical system satisfies: 4.33≤f67 / (D7s-d7s)≤5.79;

[0033] Wherein, f67 is the combined focal length of the sixth lens and the seventh lens, D7s is the outer diameter of the object side surface of the seventh spacer element, and d7s is the inner diameter of the object side surface of the seventh spacer element.

[0034] According to one technical solution of the present invention, the optical system satisfies: 5.63≤f1 / d1s≤6.90;

[0035] Where f1 is the effective focal length of the first lens, and d1s is the inner diameter of the object side surface of the first spacer element.

[0036] According to one technical solution of the present invention, the optical system satisfies: 4.46≤|f8| / (D0s-d0s)≤5.51;

[0037] Where f8 is the effective focal length of the eighth lens, D0s is the outer diameter of the object-side end of the lens barrel, and d0s is the inner diameter of the object-side end of the lens barrel.

[0038] According to one technical solution of the present invention, the air gap between the fourth lens and the fifth lens on the optical axis is not less than the air gap between any two adjacent lenses; the optical system satisfies: 2.99≤(L-ΣCT) / T45≤4.22;

[0039] Where L is the maximum height of the lens barrel, ∑CT is the sum of the thicknesses of the first lens to the eighth lens on the optical axis, and T45 is the air gap between the fourth lens and the fifth lens on the optical axis.

[0040] The optical system of this application uses eight lenses with optical power and at least one spacer element, arranged sequentially from the first to the eighth lens with intervals. This optical system satisfies 1.80≤R3 / R4*V2≤3.03 and 14.81≤f2 / T12≤16.07. The second lens uses a low-dispersion material, which is beneficial for optimizing lens dispersion correction. When light enters the second lens through the air gap between the first and second lenses on the optical axis, there is noticeable stray light at the edge of the second lens, which needs to be properly intercepted. If the light interception is not reasonable, the peak value of the field of view at the edge of the defocus curve will drop and exhibit greater dispersion, resulting in blurred images. This application, by controlling the ratio (D2s-d2s) / EP12 within a reasonable range, ensures that the channel width and interval distance of light are matched when passing through the second spacer element, effectively intercepting stray light at the edges, allowing the light to propagate to subsequent optical elements at a uniform and reasonable angle, reducing light scattering and interference, and improving image clarity. Attached Figure Description

[0041] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the embodiments will be briefly described below. Obviously, the drawings described below are merely some embodiments of the present invention, and those skilled in the art can obtain other drawings based on these drawings without any creative effort.

[0042] Figure 1 A structural layout diagram and schematic diagram of some parameters of an optical system according to the present invention are shown;

[0043] Figure 2A , Figure 2B and Figure 2C Schematic diagrams of three optical systems according to Embodiment 1 of this application are shown;

[0044] Figure 3A , Figure 3B , Figure 3C and Figure 3D The magnification chromatic aberration curve, on-axis chromatic aberration curve, distortion curve, and astigmatism curve of the optical system according to Embodiment 1 of this application are shown respectively.

[0045] Figure 4A , Figure 4B and Figure 4C Schematic diagrams of three optical systems according to Embodiment 2 of this application are shown;

[0046] Figure 5A , Figure 5B , Figure 5C and Figure 5DThe magnification chromatic aberration curve, on-axis chromatic aberration curve, distortion curve, and astigmatism curve of the optical system according to Embodiment 2 of this application are shown respectively.

[0047] Figure 6A , Figure 6B and Figure 6C Schematic diagrams of three optical systems according to Embodiment 3 of this application are shown;

[0048] Figure 7A , Figure 7B , Figure 7C and Figure 7D The magnification chromatic aberration curve, on-axis chromatic aberration curve, distortion curve, and astigmatism curve of the optical system according to Embodiment 3 of this application are shown respectively.

[0049] Figure 8 A schematic diagram of the MTF defocus curve is shown when the optical system satisfies: R3 / R4*V2=1.80, f2 / T12=15.79, (D2s-d2s) / EP12=1.28;

[0050] Figure 9 A schematic diagram of the MTF defocus curve is shown when the optical system satisfies: R3 / R4*V2=1.80, f2 / T12=15.79, (D2s-d2s) / EP12=1.82;

[0051] Figure 10 A schematic diagram of the MTF defocus curve is shown when the optical system satisfies: R3 / R4*V2=1.80, f2 / T12=15.79, (D2s-d2s) / EP12=2.25;

[0052] Figure 11 A schematic diagram of the MTF defocus curve is shown when the optical system satisfies: R3 / R4*V2=1.80, f2 / T12=15.79, (D2s-d2s) / EP12=3.15.

[0053] The above figures include the following reference numerals:

[0054] E1, First lens; P1, First spacer element; P1b, First auxiliary spacer element; P1c, First auxiliary spacer element; E2, Second lens; P2, Second spacer element; P2b, Second auxiliary spacer element; P2c, Second auxiliary spacer element; E3, Third lens; P3, Third spacer element; E4, Fourth lens; P4, Fourth spacer element; P4b, Fourth auxiliary spacer element; E5, Fifth lens; P5, Fifth spacer element; E6, Sixth lens; P6, Sixth spacer element; E7, Seventh lens; P7, Seventh spacer element; P7b, Seventh auxiliary spacer element; P7c, Seventh auxiliary spacer element. Components; E8, eighth lens; P8, eighth spacer element; S1, object-side surface of the first lens; S2, image-side surface of the first lens; S3, object-side surface of the second lens; S4, image-side surface of the second lens; S5, object-side surface of the third lens; S6, image-side surface of the third lens; S7, object-side surface of the fourth lens; S8, image-side surface of the fourth lens; S9, object-side surface of the fifth lens; S10, image-side surface of the fifth lens; S11, object-side surface of the sixth lens; S12, image-side surface of the sixth lens; S13, object-side surface of the seventh lens; S14, image-side surface of the seventh lens; S15, object-side surface of the eighth lens; S16, image-side surface of the eighth lens. Detailed Implementation

[0055] To better understand this application, various aspects of this application will be described in more detail with reference to the accompanying drawings. It should be understood that these detailed descriptions are merely illustrative of exemplary embodiments of this application and are not intended to limit the scope of this application in any way. Throughout the specification, the same reference numerals refer to the same elements. The expression "and / or" includes any and all combinations of one or more of the associated listed items.

[0056] It should be noted that in this specification, the terms "first," "second," "third," etc., are used only to distinguish one feature from another and do not imply any limitation on the features. Therefore, without departing from the teachings of this application, the first lens discussed below may also be referred to as the second lens or the third lens, or the first lens may also be referred to as the first lens element.

[0057] In the accompanying drawings, the thickness, size, and shape of the lenses have been slightly exaggerated for ease of illustration. Specifically, the shapes of the spherical or aspherical surfaces shown in the drawings are illustrated by way of example. That is, the shapes of the spherical or aspherical surfaces are not limited to those shown in the drawings. The drawings are for illustrative purposes only and are not strictly to scale.

[0058] In this paper, the paraxial region refers to the area near the optical axis. If the lens surface is convex and its location is not defined, it means that the lens surface is convex at least in the paraxial region; if the lens surface is concave and its location is not defined, it means that the lens surface is concave at least in the paraxial region. The surface shape in the paraxial region can be determined by the sign of the R value (R refers to the radius of curvature of the paraxial region). In this paper, the surface of each lens closest to the subject is called the object-side surface, and the surface of each lens closest to the image plane is called the image-side surface. For the object-side surface, when the R value is positive, it is considered convex, and when the R value is negative, it is considered concave; for the image-side surface, when the R value is positive, it is considered concave, and when the R value is negative, it is considered convex.

[0059] It should also be understood that the terms "comprising," "including," "having," "containing," and / or "comprising," when used in this specification, indicate the presence of the stated features, elements, and / or components, but do not exclude the presence or addition of one or more other features, elements, components, and / or combinations thereof. Furthermore, when expressions such as "at least one of..." appear after a list of listed features, they modify the entire list of features, not individual elements in the list. Additionally, when describing embodiments of this application, the word "may" is used to mean "one or more embodiments of this application." And the term "exemplary" is intended to refer to an example or illustration.

[0060] Unless otherwise specified, all terms used herein (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. It should also be understood that terms (e.g., those defined in common dictionaries) shall be interpreted as having the meaning consistent with their meaning in the context of the relevant art and shall not be interpreted in an idealized or overly formalized sense, unless expressly so specified herein.

[0061] It should be noted that, unless otherwise specified, the embodiments and features described in the embodiments of this application can be combined with each other. The following embodiments only illustrate several implementation methods of this application, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the patent application. It should be pointed out that, for those skilled in the art, several modifications and improvements can be made without departing from the concept of this application, and these all fall within the protection scope of this application.

[0062] like Figure 1As shown, the imaging lens group of an exemplary embodiment of the present invention includes eight lenses, which are sequentially arranged along the optical axis from the object side to the image side as follows: a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, and an eighth lens. Each lens is independent of the others, and each lens has an air gap on the optical axis. The air gap between the fourth lens and the fifth lens on the optical axis is not less than the air gap between any two adjacent lenses, that is, the air gap between the fourth lens and the fifth lens on the optical axis is the largest among all the air gaps between two adjacent lenses.

[0063] The plurality of spacer elements includes at least the first spacer element to the eighth spacer element;

[0064] The imaging lens group and multiple spacer elements are housed within the lens barrel, which includes an object-side end face, an image-side end face, an outer ring surface, and an inner ring surface. Along the optical axis of the optical system, the inner ring surface of the lens barrel is stepped.

[0065] In some embodiments of the present invention, the first lens has positive optical power, the second lens has positive optical power, the third lens has negative optical power, the fourth lens has positive optical power, the fifth lens has negative optical power, the sixth lens has positive optical power, the seventh lens has positive optical power, and the eighth lens has negative optical power. The object-side surface of the first to fifth lenses is convex and the image-side surface is concave. The object-side surface and the image-side surface of the sixth lens are both convex. The object-side surface of the seventh lens is convex and the image-side surface is concave. The object-side surface and the image-side surface of the eighth lens are both concave.

[0066] In some embodiments of the present invention, the optical system may further include color filters for correcting color deviations and / or protective glass for protecting the photosensitive element located on the imaging surface.

[0067] In some embodiments of the present invention, the optical system satisfies: 1.80≤R3 / R4*V2≤3.03; 14.81≤f2 / T12≤16.07; 1.33≤(D2s-d2s) / EP12≤3.09; where R3 is the radius of curvature of the object-side surface of the second lens, R4 is the radius of curvature of the image-side surface of the second lens, V2 is the Abbe number of the second lens, f2 is the effective focal length of the second lens, T12 is the air gap between the first lens and the second lens on the optical axis, D2s is the outer diameter of the object-side surface of the second spacer element, d2s is the inner diameter of the object-side surface of the second spacer element, and EP12 is the distance between the image-side surface of the first spacer element and the object-side surface of the second spacer element along the optical axis.

[0068] The optical system of this application uses eight lenses with optical power and at least one spacer element, arranged sequentially from the first to the eighth lens with intervals. This optical system satisfies 1.80≤R3 / R4*V2≤3.03 and 14.81≤f2 / T12≤16.07. The second lens uses a low-dispersion material, which is beneficial for optimizing lens dispersion correction. When light enters the second lens through the air gap between the first and second lenses on the optical axis, there is noticeable stray light at the edge of the second lens, which needs to be properly intercepted. If the light interception is not reasonable, the peak value of the field of view at the edge of the defocus curve will drop and exhibit greater dispersion, resulting in blurred images. To solve this problem, this application controls the ratio (D2s-d2s) / EP12 within a reasonable range, ensuring that the channel width and interval distance match when light passes through the second spacer element, effectively intercepting stray light at the edges, allowing the light to propagate to subsequent optical elements at a uniform and reasonable angle, reducing light scattering and interference, and improving image clarity.

[0069] In addition, refer to Figures 8 to 11 As shown, Figure 8 A schematic diagram of the MTF defocus curve of an optical system is shown, which satisfies R3 / R4*V2=1.80, f2 / T12=15.79 and (D2s-d2s) / EP12=1.28. Figure 9 A schematic diagram of the MTF defocus curve of an optical system is shown, which satisfies R3 / R4*V2=1.80, f2 / T12=15.79 and (D2s-d2s) / EP12=1.82. Figure 10 A schematic diagram of the MTF defocus curve of an optical system is shown, which satisfies R3 / R4*V2=1.80, f2 / T12=15.79 and (D2s-d2s) / EP12=2.25. Figure 11 A schematic diagram of the MTF defocus curve of an optical system is shown, which satisfies R3 / R4*V2=1.80, f2 / T12=15.79 and (D2s-d2s) / EP12=3.15.

[0070] Depend on Figures 8 to 11 As shown, if the value of (D2s-d2s) / EP12 is less than the lower limit of 1.33, for example, if we take 1.28, then... Figure 8 As shown, at this time, the channel through the second spacer element is relatively too wide, and the second spacer element cannot effectively block stray light from the edge of the second lens. This causes the lens's defocus curve to become diffused and the edge field of view peak to drop, resulting in blurred images. If the value of (D2s-d2s) / EP12 is greater than the upper limit of 3.09, for example, 3.15, then... Figure 11As shown, the second spacer element excessively intercepts light from the edge of the second lens, reducing the effective light amount at the edge of the field of view, lowering light utilization, decreasing overall image sharpness, and exacerbating the dispersion of the lens's defocus curve and the drop in the edge field of view peak, resulting in blurred images. When the value of (D2s-d2s) / EP12 is within the conditional range, for example, taking 1.82 or 2.25, such as... Figure 9 and 10 As shown, it can retain the effective light at the edge of the field of view while blocking stray light at the edge of the lens, thereby improving the image sharpness. The lens defocus curve is normal, and the image is relatively clear.

[0071] In some embodiments of the present invention, the optical system satisfies: 5.63≤f1 / d1s≤6.90; where f1 is the effective focal length of the first lens and d1s is the inner diameter of the object side of the first spacer element.

[0072] By controlling the ratio of the effective focal length f1 of the first lens to the inner diameter d1s of the object side surface of the first spacer element, the direction of light at the first lens can be controlled, effectively adjusting the convergence and divergence of light. At the same time, controlling the inner diameter of the object side surface of the first spacer element helps to reduce the amount of edge light entering the second lens and improve the image quality.

[0073] In some embodiments of the present invention, the optical system satisfies: 2.42≤(D7m-d7m) / (D8s-d8s)≤3.68; where D7m is the outer diameter of the image side of the seventh spacer element, d7m is the inner diameter of the image side of the seventh spacer element, D8s is the outer diameter of the object side of the eighth spacer element, and d8s is the inner diameter of the object side of the eighth spacer element.

[0074] By controlling the proportional relationship between the difference between the outer and inner diameters of the image side of the seventh spacer and the difference between the outer and inner diameters of the object side of the eighth spacer, the size structure of the seventh and eighth spacers in the optical system can be optimized. This helps reduce aberrations caused by inconsistencies in element size ratios, thereby improving image quality, making images clearer, and enabling more accurate representation of image edges and details.

[0075] In some embodiments of the present invention, the optical system satisfies: 1.78≤EP45 / CT5≤2.33; where EP45 is the distance between the image side of the fourth spacer element and the object side of the fifth spacer element along the optical axis, and CT5 is the thickness of the fifth lens on the optical axis.

[0076] By controlling the ratio of the spacing EP45 between the fourth and fifth spacers along the optical axis to the thickness CT5 of the fifth lens on the optical axis, the light deflection angle can be controlled, the sensitivity of the fifth lens can be reduced, and the structure of the fifth lens can be optimized to ensure that the fifth lens has good formability.

[0077] In some embodiments of the present invention, the optical system satisfies: 1.70≤(d7s-d6m) / CT7≤2.53; where d7s is the inner diameter of the object side of the seventh spacer element, d6m is the inner diameter of the image side of the sixth spacer element, and CT7 is the thickness of the seventh lens on the optical axis.

[0078] This conditional formula restricts the dimensional ratio between the seventh spacer element, the sixth spacer element, and the seventh lens, reducing performance fluctuations caused by excessive differences in component dimensions, improving product consistency and reliability, and increasing the yield and stability of lens assembly.

[0079] In some embodiments of the present invention, the optical system satisfies: 1.97≤EP23 / (CT3+T23)≤2.89; where EP23 is the distance between the image side of the second spacer element and the object side of the third spacer element along the optical axis, CT3 is the thickness of the third lens on the optical axis, and T23 is the air gap between the second lens and the third lens on the optical axis.

[0080] By restricting the above conditions, the propagation path of light in the second and third lenses and their interval regions can be optimized, which helps to reduce light aberrations such as spherical aberration and coma, and allows light to propagate to subsequent optical elements at a uniform and reasonable angle, thereby improving image quality.

[0081] In some embodiments of the present invention, the optical system satisfies: 2.99≤(L-ΣCT) / T45≤4.22; where L is the maximum height of the lens barrel, ΣCT is the sum of the thicknesses of the first to eighth lenses on the optical axis, and T45 is the air gap between the fourth and fifth lenses on the optical axis.

[0082] By controlling the above conditions, the internal spatial layout of the lens can be rationally planned, making the lens structure more compact. At the same time, the relative positions and spacing of each component can be better controlled during assembly, improving the stability of lens assembly.

[0083] In some embodiments of the present invention, the optical system satisfies: 2.03≤f6 / D6s≤3.92; where f6 is the effective focal length of the sixth lens and D6s is the outer diameter of the side surface of the sixth spacer element.

[0084] By controlling the ratio of the effective focal length of the sixth lens to the outer diameter of the side of the sixth spacer element within a certain range, light can be propagated and focused in the best way; at the same time, the internal space of the lens is used reasonably to avoid structural irrationality caused by the outer diameter of the spacer element being too large or too small.

[0085] In some embodiments of the present invention, the optical system satisfies: 11.23≤d3s / CT3≤13.12; where d3s is the inner diameter of the object side of the third spacer element, and CT3 is the thickness of the third lens on the optical axis.

[0086] By limiting the ratio of the inner diameter d3s of the object side of the third spacer element to the thickness CT3 of the third lens on the optical axis, the amount and angle of light entering the third lens can be controlled. Appropriate light intake and angle help light propagate and focus better in the third lens and subsequent optical systems, reducing light scattering and aberrations such as spherical aberration and chromatic aberration, thereby improving image sharpness and resolution, and significantly enhancing overall image quality.

[0087] In some embodiments of the present invention, the optical system satisfies: 3.33≤R10 / (D5s-d5s)≤4.50; where R10 is the radius of curvature of the image side of the fifth lens, D5s is the outer diameter of the object side of the fifth spacer element, and d5s is the inner diameter of the object side of the fifth spacer element.

[0088] By controlling the ratio of the curvature radius of the fifth lens's image side to the difference between the inner and outer diameters of the fifth spacer element's object side, the curvature radius of the fifth lens's image side is ensured to match the size of the fifth spacer element. This allows the lens shape to be in a more reasonable and easier-to-process state, reducing the difficulty of lens forming, improving the feasibility of lens processing, and avoiding lens shape deviations caused by mismatch between the curvature radius and the spacer element size, thereby improving production efficiency and yield.

[0089] In some embodiments of the present invention, the optical system satisfies: 4.23≤R8 / d4s≤5.21; where R8 is the radius of curvature of the image side of the fourth lens, and d4s is the inner diameter of the object side of the fourth spacer element.

[0090] This condition constrains the curvature of the image side surface of the fourth lens, and controls the ratio of the radius of curvature R8 of the image side surface of the fourth lens to the inner diameter d4s of the object side surface of the fourth spacer element within a suitable range. This allows light to exit at a more reasonable angle after passing through the fourth lens, which helps to correct optical defects such as aberration and chromatic aberration, thereby improving image quality, making the image clearer and sharper, and reducing image distortion and blur.

[0091] In some embodiments of the present invention, the optical system satisfies: 4.46≤|f8| / (D0s-d0s)≤5.51; where f8 is the effective focal length of the eighth lens, D0s is the outer diameter of the object-side end of the lens barrel, and d0s is the inner diameter of the object-side end of the lens barrel.

[0092] By utilizing the above conditional formulas, the propagation angle and convergence of light rays after passing through the lens can be controlled. When the ratio is outside the range, the lens has a strong converging ability, and the light rays may converge too early after passing through the object side of the lens barrel, resulting in a forward focus on the imaging plane and a blurred image. Conversely, when the ratio is below the range, the light convergence ability is insufficient, and the light rays are prone to divergence, resulting in uneven light distribution on the imaging plane and reduced sharpness.

[0093] In some embodiments of the present invention, the optical system satisfies: 4.33≤f67 / (D7s-d7s)≤5.79; where f67 is the combined focal length of the sixth and seventh lenses, D7s is the outer diameter of the object side of the seventh spacer element, and d7s is the inner diameter of the object side of the seventh spacer element.

[0094] Within the above conditions, light rays, after passing through the spacer element, converge uniformly at a reasonable angle to the subsequent optical elements, ensuring accurate focus on the imaging plane and consistent sharpness at the edges and center of the field of view. If the ratio exceeds the range, the lens group's ability to converge light rays will be insufficient, resulting in excessive divergence after the light rays pass through the spacer element. If the ratio is less than the range, it means the lens group's ability to converge light rays is too strong, causing the light rays to converge prematurely after passing through the spacer element. The imaging plane becomes out of focus due to the shift in the convergence position of the light rays, resulting in an overall blurred image, especially noticeable at the edges of the field of view.

[0095] In some embodiments of the present invention, the optical system satisfies: 0.87≤EP78 / EP67≤1.87; wherein, EP78 is the distance between the image side of the seventh spacer element and the object side of the eighth spacer element along the optical axis, and EP67 is the distance between the image side of the sixth spacer element and the object side of the seventh spacer element along the optical axis.

[0096] By controlling the ratio of EP78 to EP67, a standardized support structure can be used between the sixth and eighth lenses, reducing manufacturing complexity and enhancing mechanical stability. This helps prevent component deformation and damage caused by long-term mechanical stress, extending their service life.

[0097] The optical system according to the above embodiments of this application can employ multiple lenses, such as the eight lenses mentioned above. By rationally allocating the optical power, surface shape, and arrangement of the spacers of each lens, the range of each lens-tube engagement is made more uniform, enhancing the light-gathering ability and improving the imaging quality of the optical system. However, those skilled in the art should understand that the number of lenses constituting the optical system can be changed without departing from the technical solutions claimed in this application to obtain the various results and advantages described in this specification. For example, although eight lenses are described as an example in the embodiments, the optical system is not limited to including eight lenses. If necessary, the optical system may also include other numbers of lenses.

[0098] In some embodiments of the present invention, the lens material in the optical system provided by the present invention can be glass or plastic. When the lens material is plastic, production costs can be effectively reduced. Conversely, when the lens material is glass, the low dispersion characteristic of glass itself can effectively correct the geometric chromatic aberration of the optical system. The optical system provided by the present invention can adopt an all-plastic lens structure, which not only gives the lens excellent imaging performance but also allows for a more compact lens structure, achieving a better balance between lens miniaturization and high image quality.

[0099] In some embodiments of the present invention, the first lens, second lens, third lens, fourth lens, fifth lens, sixth lens, seventh lens, and eighth lens can be spherical lenses or aspherical lenses. Compared with spherical structures, aspherical structures can effectively reduce the aberrations of the optical system, thereby reducing the number of lenses and the size of the lenses, and better achieving lens miniaturization. More specifically, the first lens, second lens, third lens, fourth lens, fifth lens, sixth lens, seventh lens, and eighth lens of the present invention can all be aspherical lenses, which can effectively reduce the aberrations of the optical system, thereby reducing the number of lenses and the size of the lenses, and achieving lens miniaturization.

[0100] 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 system 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.

[0101] Example 1

[0102] The following is for reference Figures 2A to 3D An optical system according to Embodiment 1 of this application is described. Figure 2A , Figure 2B and Figure 2C The schematic diagrams of the optical systems 1001, 1002 and 1003 of Embodiment 1 of this application are shown respectively.

[0103] like Figure 2A , Figure 2B and Figure 2C As shown, optical systems 1001, 1002 and 1003 all include a lens barrel structure, imaging lens groups E1 to E8 and multiple spacer elements P1 to P8.

[0104] In Embodiment 1, the schematic diagrams of optical systems 1001, 1002, and 1003 employ the same imaging lens group. From the object side to the image side, the imaging lens group sequentially includes: a first lens E1 with positive optical power, a second lens E2 with positive optical power, a third lens E3 with negative optical power, a fourth lens E4 with positive optical power, a fifth lens E5 with negative optical power, a sixth lens E6 with positive optical power, a seventh lens E7 with positive optical power, and an eighth lens E8 with negative optical power. The object side of the first lens E1 to the fifth lens E5 is convex, and the image side is concave. The object side and image side of the sixth lens E6 are both convex. The object side of the seventh lens E7 is convex, and the image side is concave. The object side and image side of the eighth lens E8 are both concave. An aperture stop is positioned between the first lens E1 and the second lens E2. Light from the object passes sequentially through surfaces S1 to S16 and is finally imaged onto the imaging surface S19. Among them, surfaces S17 and S18 can be the object-side and image-side of a filter or protective glass, and surface S19 is the imaging surface (S17, S18, S19, etc.). Figure 2A As shown in the figure (other figures omitted), OBJ (not shown in the figure) is the object distance, and STO (not shown in the figure) is the aperture stop.

[0105] Table 1 lists the relevant parameters of each lens in the optical system of this embodiment, where the units for radius of curvature and thickness are millimeters (mm).

[0106]

[0107]

[0108] Table 1

[0109] In this embodiment, each lens is an aspherical lens, and the surface shape of each aspherical lens can be defined using, but is not limited to, the following aspherical formula:

[0110]

[0111] In the above formula, z is the axial distance from the vertex to the surface at a position perpendicular to the optical axis at a height y; c represents the curvature at the vertex of the aspherical surface; k is the conic coefficient; A4, A6, A8, A 10 A 12 A 14 A 16 ...represent aspheric coefficients of the fourth, sixth, eighth, tenth, twelfth, fourteenth, and sixteenth orders, respectively.

[0112] Table 2 lists the aspherical coefficients of each aspherical lens in the optical system of this embodiment, including: A4, A6, A8, A... 10 A12 A 14 A 16 A 18 A 20 .

[0113]

[0114]

[0115] Table 2

[0116] like Figure 2A and 2B As shown, Figure 2A and 2B These are schematic diagrams of the optical systems 1001 and 1002 in this embodiment. In this embodiment, optical systems 1001 and 1002 each include eight spacer elements. The first spacer element P1 is disposed between the first lens E1 and the second lens E2 and is in contact with the image-side surface of the first lens E1. The second spacer element P2 is disposed between the second lens E2 and the third lens E3 and is in contact with the image-side surface of the second lens E2. The third spacer element P3 is disposed between the third lens E3 and the fourth lens E4 and is in contact with the image-side surface of the third lens E3. The fourth spacer element P4 is disposed between the fourth lens E4 and the fifth lens E5 and is in contact with the image-side surface of the fourth lens E4. The fifth spacer element P5 is disposed between the fifth lens E5 and the sixth lens E6 and is in contact with the image-side surface of the fifth lens E5. The fifth spacer element P5 is disposed between the fifth lens E5 and the sixth lens E6 and contacts the image-side surface of the fifth lens E5. The sixth spacer element P6 is disposed between the sixth lens E6 and the seventh lens E7 and contacts the image-side surface of the sixth lens E6. The seventh spacer element P7 is disposed between the seventh lens E7 and the eighth lens E8 and contacts the image-side surface of the seventh lens E7. The eighth spacer element P8 is disposed on the image-side surface of the eighth lens E8 and contacts the image-side surface of the eighth lens E8. In this embodiment, the first spacer elements P1 to the eighth spacer element P8 are spacers. The aforementioned spacer elements P1 to P8 can block excess external light from entering, allowing the lens and lens barrel to better support each other, and enhancing the structural stability of optical systems 1001 and 1002.

[0117] like Figure 2C As shown, Figure 2CThis is a schematic diagram of the structure of the optical system 1003 in this embodiment. Unlike the optical system 1001, the optical system 1003 also includes a seventh auxiliary spacer element P7b and a seventh secondary auxiliary spacer element P7c. In this case, the image side of the seventh spacer element P7b is in contact with the object side of the seventh auxiliary spacer element P7b, the image side of the seventh auxiliary spacer element P7b is in contact with the object side of the seventh secondary auxiliary spacer element P7c, and the image side of the seventh secondary auxiliary spacer element P7c is in contact with the object side S15 of the eighth lens E8. The contact method of the remaining spacers is the same as that of the optical system 1001, and can be referred to the relevant description in the optical system 1001, which will not be repeated here.

[0118] The differences between optical systems 1001, 1002, and 1003 may also lie in the size of the spacer element, the non-effective diameter region of the lens, and the lens barrel structural parameters. Table 3 shows the basic parameters of the spacer element and lens barrel of optical systems 1001, 1002, and 1003 in Embodiment 1. As an example, optical systems 1001, 1002, and 1003 all have a single lens barrel.

[0119] d1s(mm) 3.0423 3.0423 3.0423 d2s(mm) 3.6307 3.6258 3.6344 D2s(mm) 5.3140 5.3091 5.3140 d3s(mm) 3.7910 3.7910 3.7910 d4s(mm) 4.3551 4.3551 4.3551 d5s(mm) 5.5722 5.5722 5.5722 D5s(mm) 6.6077 6.6077 6.8310 d6m (mm) 6.4386 6.4386 6.4386 D6s(mm) 10.2265 7.6096 7.6096 d7s(mm) 7.8940 7.8940 7.6497 d7m(mm) 7.8500 7.8500 7.6057 D7s(mm) 10.4886 10.4886 10.4886 D7m (mm) 10.4886 10.4886 10.4886 d8s(mm) 9.4989 9.3989 9.5989 D8s(mm) 10.5886 10.4886 10.6886 d0s(mm) 5.1856 5.1856 5.1856 D0s(mm) 6.3664 6.5948 6.3664 EP12(mm) 0.8331 0.7925 0.8640 EP23(mm) 0.8745 0.9152 0.8437 EP45(mm) 0.6085 0.6085 0.6046 EP67(mm) 0.7278 0.7278 0.5836 EP78(mm) 0.8726 0.8726 1.0168 L(mm) 7.1027 7.1027 6.3752 ΣCT(mm) 4.4253 4.4253 4.4253

[0120] Table 3

[0121] Figure 3A The magnification chromatic aberration curve of the optical system of Embodiment 1 is shown, which represents the deviation of different image heights on the imaging plane after light passes through the lens. Figure 3B The on-axis chromatic aberration curve of the optical system of Embodiment 1 is shown, which represents the deviation of the focal point of light of different wavelengths after passing through the lens. Figure 3C The distortion curves of the optical system of Embodiment 1 are shown, which represent the distortion magnitude values ​​corresponding to different image heights. Figure 3D The astigmatism curves of the optical system of Embodiment 1 are shown, representing the meridional image plane curvature and the sagittal image plane curvature. According to... Figures 3A to 3D As can be seen, the optical system given in Example 1 can achieve good imaging quality.

[0122] Example 2

[0123] The following is for reference Figures 4A to 5D An optical system according to Embodiment 2 of this application is described. Figure 4A , Figure 4B and Figure 4C Schematic diagrams of the optical systems 2001, 2002, and 2003 of Embodiment 2 of this application are shown respectively.

[0124] like Figure 4A , Figure 4B and Figure 4CAs shown, the structural schematic diagrams of optical systems 2001, 2002, and 2003 all include a lens barrel structure, imaging lens groups E1 to E8, and multiple spacer elements P1 to P8.

[0125] In Embodiment 2, the schematic diagrams of optical systems 2001, 2002, and 2003 all employ the same imaging lens group. From the object side to the image side, the imaging lens group sequentially includes: a first lens E1 with positive optical power, a second lens E2 with positive optical power, a third lens E3 with negative optical power, a fourth lens E4 with positive optical power, a fifth lens E5 with negative optical power, a sixth lens E6 with positive optical power, a seventh lens E7 with positive optical power, and an eighth lens E8 with negative optical power. The object-side surfaces of lenses E1 to E5 are all convex, and the image-side surfaces are all concave. The object-side and image-side surfaces of lens E6 are both convex. The object-side surface of lens E7 is both convex, and the image-side surface of lens E7 is both concave. The object-side and image-side surfaces of lens E8 are both concave. An aperture stop is positioned between the first lens E1 and the second lens E2. Light from the object passes sequentially through surfaces S1 to S16 and is finally imaged onto the imaging surface S19. Among them, surfaces S17 and S18 (not shown in the figure) can be the object side and image side of the filter or protective glass, surface S19 (not shown in the figure) is the imaging surface, OBJ (not shown in the figure) is the object distance, and STO (not shown in the figure) is the aperture stop.

[0126] Table 4 lists the relevant parameters of each lens in the optical system of this embodiment, where the units for radius of curvature and thickness are millimeters (mm).

[0127]

[0128]

[0129] Table 4

[0130] Table 5 lists the aspherical coefficients of each aspherical lens in the optical system of this embodiment, including: A4, A6, A8, A... 10 A 12 A 14 A 16 A 18 A 20 Among them, each aspherical coefficient satisfies formula (1) given in Example 1 above.

[0131]

[0132]

[0133] Table 5

[0134] like Figure 4Aand Figure 4B As shown, both optical systems 2001 and 2002 include eight spacer elements, namely, the first spacer element P1, the second spacer element P2, the third spacer element P3, the fourth spacer element P4, the fifth spacer element P5, the sixth spacer element P6, the seventh spacer element P7, and the eighth spacer element P8. Since the positions of these eight spacer elements are the same as those of the spacer elements in optical systems 1001 and 1002 of Embodiment 1, they will not be described again.

[0135] like Figure 4C The diagram shown is a structural schematic of the optical system 2003 in this embodiment. Unlike optical system 1001, optical system 2003 also includes a first auxiliary spacer element P1b, a first auxiliary spacer element P1c, a seventh auxiliary spacer element P7b, and a seventh auxiliary spacer element P7c. In this case, the image side of the first spacer element P1b is in contact with the object side of the first auxiliary spacer element P1b, the image side of the first auxiliary spacer element P1b is in contact with the object side of the first auxiliary spacer element P1c, and the image side of the first auxiliary spacer element P1c is in contact with the object side S3 of the second lens E2. The image side of the seventh spacer element P7b is in contact with the object side of the seventh auxiliary spacer element P7b, the image side of the seventh auxiliary spacer element P7b is in contact with the object side of the seventh auxiliary spacer element P7c, and the image side of the seventh auxiliary spacer element P7c is in contact with the object side S15 of the eighth lens E8. The contact method of the remaining spacers is the same as that of optical system 1001, and can be referred to the relevant description in optical system 1001, which will not be repeated here.

[0136] The differences between optical systems 2001, 2002, and 2003 may also lie in the size of the spacer element, the non-effective diameter region of the lens, and the lens barrel structural parameters. Table 6 shows the basic parameters of the spacer element and lens barrel of optical systems 2001, 2002, and 2003 in Embodiment 2. As an example, optical systems 2001, 2002, and 2003 all have a single lens barrel.

[0137] d1s(mm) 2.9989 2.9989 2.9989 d2s(mm) 3.0026 3.0026 2.9949 D2s(mm) 5.3412 4.1296 4.1218 d3s(mm) 3.4666 3.4066 3.3605 d4s(mm) 4.1969 4.2958 4.3238 d5s(mm) 5.5467 5.5467 5.5467 D5s(mm) 6.6349 6.6349 6.6349 d6m (mm) 6.4658 6.4658 6.4658 D6s(mm) 10.2543 10.2543 10.2537 d7s(mm) 8.1538 8.0069 7.6851 d7m(mm) 8.1098 7.9629 7.6411 D7s(mm) 10.5158 10.5158 10.5158 D7m (mm) 10.5158 10.5158 10.5158 d8s(mm) 9.6560 9.6560 9.8560 D8s(mm) 10.5158 10.5158 10.7158 d0s(mm) 5.2128 5.2128 5.2128 D0s(mm) 6.3936 6.3936 6.3968 EP12(mm) 0.8273 0.8274 0.8499 EP23(mm) 0.7598 0.7283 0.7058 EP45(mm) 0.6085 0.5608 0.5473 EP67(mm) 0.8002 0.7259 0.5632 EP78(mm) 0.8166 0.8909 1.0536 L(mm) 7.1027 7.1027 7.1027 ΣCT(mm) 4.4300 4.4300 4.4300

[0138] Table 6

[0139] Figure 5A The magnification chromatic aberration curve of the optical system of Embodiment 2 is shown, which represents the deviation of different image heights on the imaging plane after light passes through the lens. Figure 5B The on-axis chromatic aberration curve of the optical system of Embodiment 2 is shown, which represents the deviation of the focal point of light of different wavelengths after passing through the lens. Figure 5CThe distortion curves of the optical system in Embodiment 2 are shown, representing the distortion magnitude values ​​corresponding to different image heights. Figure 5D The astigmatism curves of the optical system in Embodiment 2 are shown, representing the meridional image plane curvature and the sagittal image plane curvature. According to... Figures 5A to 5D It can be seen that the optical system given in Example 2 can achieve good imaging quality.

[0140] Example 3

[0141] The following is for reference Figures 6A to 7D An optical system according to Embodiment 3 of this application is described. Figure 6A , Figure 6B and Figure 6C The schematic diagrams of the optical systems 3001, 3002 and 3003 of Embodiment 3 of this application are shown respectively.

[0142] like Figure 6A , Figure 6B and Figure 6C As shown, optical systems 3001, 3002 and 3003 all include a lens barrel structure, imaging lens groups E1 to E8 and multiple spacer elements P1 to P8.

[0143] In Embodiment 3, the schematic diagrams of optical systems 3001, 3002, and 3003 employ the same imaging lens group. From the object side to the image side, the imaging lens group sequentially includes: a first lens E1 with positive optical power, a second lens E2 with positive optical power, a third lens E3 with negative optical power, a fourth lens E4 with positive optical power, a fifth lens E5 with negative optical power, a sixth lens E6 with positive optical power, a seventh lens E7 with positive optical power, and an eighth lens E8 with negative optical power. The object side of lenses E1 to E5 is convex, and the image side is concave. The object side and image side of lens E6 are both convex. The object side of lens E7 is convex, and the image side is concave. The object side and image side of lens E8 are both concave. An aperture stop is positioned between the first lens E1 and the second lens E2. Light from the object passes sequentially through surfaces S1 to S16 and is finally imaged onto the imaging surface S19. Among them, surfaces S17 and S18 (not shown in the figure) can be the object side and image side of the filter or protective glass, surface S19 (not shown in the figure) is the imaging surface, OBJ (not shown in the figure) is the object distance, and STO (not shown in the figure) is the aperture stop.

[0144] Table 7 lists the relevant parameters of each lens in the optical system of this embodiment, where the units for radius of curvature and thickness are millimeters (mm).

[0145]

[0146]

[0147] Table 7

[0148] Table 8 lists the aspherical coefficients of each aspherical lens in the optical system of this embodiment, including: A4, A6, A8, A... 10 A 12 A 14 A 16 A 18 A 20 Among them, each aspherical coefficient satisfies formula (1) given in Example 1 above.

[0149] S1 5.5292E-04 4.2459E-04 -5.5384E-04 -3.9348E-05 4.2725E-07 -4.3995E-07 -1.1118E-07 S2 3.3274E-03 -2.3030E-03 -1.7347E-05 -5.5704E-05 -2.1042E-05 -6.3447E-06 -9.1263E-07 S3 -1.6036E-03 9.6439E-04 -1.4750E-03 -1.8175E-05 -1.2875E-05 -1.6872E-06 -3.6253E-07 S4 -2.9584E-03 -4.0321E-03 -4.6928E-04 1.5521E-05 -3.9903E-06 5.3351E-07 -5.3326E-08 S5 -9.1721E-03 1.8117E-04 1.7073E-04 4.5594E-05 9.9558E-06 1.5593E-06 -4.8698E-07 S6 -3.0300E-03 1.3509E-03 3.1825E-04 7.0352E-06 -3.7874E-06 -2.3594E-06 -3.6534E-07 S7 3.9063E-04 1.9361E-04 -5.8056E-04 -1.1509E-05 4.4748E-06 2.0475E-07 -3.6385E-07 S8 1.0504E-03 2.8570E-04 -3.0191E-04 -1.4719E-05 -1.7012E-06 -2.9648E-08 4.3880E-08 S9 -8.4280E-03 -1.5819E-03 -5.0164E-05 -1.3385E-05 -3.3800E-06 -6.3487E-07 -1.0494E-07 S10 -6.8589E-03 -3.0603E-04 -6.9544E-05 -2.3676E-06 3.3587E-07 4.6515E-08 1.6966E-09 S11 -2.3055E-03 -6.6963E-04 -2.3245E-05 -3.2365E-07 1.5692E-08 5.2670E-11 2.5166E-10 S12 1.8531E-03 -9.8687E-04 1.9979E-06 -3.9811E-07 -4.6158E-09 2.4732E-09 2.9835E-10 S13 -1.6502E-02 -5.0442E-05 1.2408E-05 1.4415E-06 9.6819E-08 3.4849E-09 -7.9403E-11 S14 -6.9743E-03 -4.2073E-04 1.1097E-05 2.3758E-07 1.0493E-08 2.6239E-10 -4.3778E-12 S15 6.5891E-05 1.2490E-04 -9.7554E-06 -6.2474E-08 2.3547E-09 3.2581E-10 1.6925E-11 S16 -7.8716E-03 3.2929E-04 -2.2662E-06 -9.9437E-08 -3.2589E-09 -1.4220E-10 -5.0896E-12 Face number <![CDATA[A 18 ]]> <![CDATA[A 20 ]]> S1 -4.6197E-09 5.1527E-08 S2 5.0988E-07 4.5060E-07 S3 7.1270E-08 1.5861E-07 S4 -1.0405E-07 -6.1327E-08 S5 -7.1845E-08 -1.0989E-07 S6 -1.2787E-07 3.3243E-08 S7 -1.0806E-07 -1.5010E-08 S8 1.3620E-08 2.2756E-09 S9 -2.8672E-09 1.7276E-09 S10 -3.0780E-10 -8.3324E-11 S11 4.3438E-11 7.7756E-12 S12 3.8506E-11 2.8507E-12 S13 -2.8187E-11 -3.6014E-12 S14 -7.5012E-13 -8.0151E-14 S15 2.1233E-13 -3.2958E-14 S16 7.1195E-14 1.3975E-14

[0150] Table 8

[0151] like Figure 6A and Figure 6B As shown, both optical systems 3001 and 3002 include eight spacer elements, namely, the first spacer element P1, the second spacer element P2, the third spacer element P3, the fourth spacer element P4, the fifth spacer element P5, the sixth spacer element P6, the seventh spacer element P7, and the eighth spacer element P8. Since the positions of these eight spacer elements are the same as those of the spacer elements in optical systems 1001 and 1002 of Embodiment 1, they will not be described again.

[0152] like Figure 6C The diagram shown is a structural schematic of the optical system 3003 in this embodiment. Unlike optical system 1001, optical system 3003 also includes a second auxiliary spacer element P2b, a second auxiliary spacer element P2c, a seventh auxiliary spacer element P7b, and a seventh auxiliary spacer element P7c. In this case, the image side of the second spacer element P2b is in contact with the object side of the second auxiliary spacer element P2b, the image side of the second auxiliary spacer element P2b is in contact with the object side of the second auxiliary spacer element P2c, and the image side of the second auxiliary spacer element P2c is in contact with the object side S5 of the third lens E3. The image side of the seventh spacer element P7b is in contact with the object side of the seventh auxiliary spacer element P7b, the image side of the seventh auxiliary spacer element P7b is in contact with the object side of the seventh auxiliary spacer element P7c, and the image side of the seventh auxiliary spacer element P7c is in contact with the object side S15 of the eighth lens E8. The contact method of the remaining spacers is the same as that of optical system 1001, and can be referred to the relevant description in optical system 1001, which will not be repeated here.

[0153] The differences between optical systems 3001, 3002, and 3003 may also lie in the size of the spacer element, the non-effective diameter region of the lens, and the lens barrel structural parameters. Table 9 shows the basic parameters of the spacer element and lens barrel of optical systems 3001, 3002, and 3003 in Embodiment 3. As an example, optical systems 3001, 3002, and 3003 all have a lens barrel.

[0154]

[0155]

[0156] Table 9

[0157] Figure 7A The magnification chromatic aberration curve of the optical system of Embodiment 3 is shown, which represents the deviation of different image heights on the imaging plane after light passes through the lens. Figure 7B The on-axis chromatic aberration curve of the optical system of Embodiment 3 is shown, which represents the deviation of the focal point of light of different wavelengths after passing through the lens. Figure 7C The distortion curves of the optical system in Embodiment 3 are shown, representing the distortion magnitude values ​​corresponding to different image heights. Figure 7D The astigmatism curves of the optical system in Embodiment 3 are shown, representing the meridional image plane curvature and the sagittal image plane curvature. According to... Figures 7A to 7D As can be seen, the optical system given in Example 3 can achieve good imaging quality.

[0158] In summary, the optical parameters of the optical systems 1001, 1002, 1003, 2001, 2002, 2003, 3001, 3002 and 3003 of Embodiments 1 to 3 are shown in Table 10 below.

[0159]

[0160] Table 10

[0161] The optical systems 1001, 1002, 1003, 2001, 2002, 2003, 3001, 3002, and 3003 of Embodiments 1 to 3 satisfy the relationships shown in Table 11.

[0162]

[0163] Table 11

[0164] The above description is merely a preferred embodiment of this application and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention involved in this application is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the inventive concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features with similar functions disclosed in this application.

Claims

1. An optical system comprising a lens barrel and an imaging lens group and a plurality of spacer elements disposed within the lens barrel, characterized in that, The imaging lens group comprises, sequentially from the object side to the image side along the optical axis: a first lens with positive optical power, a second lens with positive optical power, a third lens with negative optical power, a fourth lens with positive optical power, a fifth lens with negative optical power, a sixth lens with positive optical power, a seventh lens with positive optical power, and an eighth lens with negative optical power, totaling eight lenses with optical power. The first to fifth lenses have convex object-side surfaces and concave image-side surfaces. The sixth lens has convex object-side surfaces and concave image-side surfaces. The eighth lens has concave object-side surfaces and concave image-side surfaces. The plurality of spacers include a first spacer located between the first lens and the second lens and at least partially abutting the image side of the first lens, and a second spacer located between the second lens and the third lens and at least partially abutting the image side of the second lens; The optical system satisfies: 1.80≤R3 / R4*V2≤3.03; 14.81≤f2 / T12≤16.07; 1.33≤(D2s-d2s) / EP12≤3.09; Wherein, R3 is the radius of curvature of the object side of the second lens, R4 is the radius of curvature of the image side of the second lens, V2 is the Abbe number of the second lens, f2 is the effective focal length of the second lens, T12 is the air gap between the first lens and the second lens on the optical axis, D2s is the outer diameter of the object side of the second spacer element, d2s is the inner diameter of the object side of the second spacer element, and EP12 is the distance between the image side of the first spacer element and the object side of the second spacer element along the optical axis.

2. The optical system according to claim 1, characterized in that, The plurality of spacers also includes a third spacer located between the third lens and the fourth lens and at least partially abutting the image side of the third lens; The optical system satisfies: 1.97≤EP23 / (CT3+T23)≤2.89; Wherein, EP23 is the distance between the image side of the second spacer element and the object side of the third spacer element along the optical axis, CT3 is the thickness of the third lens on the optical axis, and T23 is the air gap between the second lens and the third lens on the optical axis.

3. The optical system according to claim 2, characterized in that, The optical system satisfies: 11.23 ≤ d3s / CT3 ≤ 13.12; Wherein, d3s is the inner diameter of the object side of the third spacer element, and CT3 is the thickness of the third lens on the optical axis.

4. The optical system according to claim 1, characterized in that, The plurality of spacers further includes a fourth spacer located between the fourth lens and the fifth lens and at least partially abutting the image side of the fourth lens, and a fifth spacer located between the fifth lens and the sixth lens and at least partially abutting the image side of the fifth lens; the optical system satisfies: 1.78≤EP45 / CT5≤2.33; Wherein, EP45 is the distance between the image side of the fourth spacer element and the object side of the fifth spacer element along the optical axis, and CT5 is the thickness of the fifth lens along the optical axis.

5. The optical system according to claim 4, characterized in that, The optical system satisfies: 3.33≤R10 / (D5s-d5s)≤4.50; Wherein, R10 is the radius of curvature of the image side of the fifth lens, D5s is the outer diameter of the object side of the fifth spacer element, and d5s is the inner diameter of the object side of the fifth spacer element.

6. The optical system according to claim 4, characterized in that, The optical system satisfies: 4.23 ≤ R⁸ / d⁴s ≤ 5.21; Wherein, R8 is the radius of curvature of the image side of the fourth lens, and d4s is the inner diameter of the object side of the fourth spacer element.

7. The optical system according to claim 1, characterized in that, The plurality of spacers also includes a seventh spacer located between the seventh lens and the eighth lens and at least partially abutting the image side of the seventh lens, and an eighth spacer located on the image side of the eighth lens and at least partially abutting the image side of the eighth lens. The optical system satisfies: 2.42≤(D7m-d7m) / (D8s-d8s)≤3.68; Wherein, D7m is the outer diameter of the image side of the seventh spacer element, d7m is the inner diameter of the image side of the seventh spacer element, D8s is the outer diameter of the object side of the eighth spacer element, and d8s is the inner diameter of the object side of the eighth spacer element.

8. The optical system according to claim 7, characterized in that, The plurality of spacers also includes a sixth spacer located between the sixth lens and the seventh lens and at least partially abutting the image side of the sixth lens; the optical system satisfies: 1.70≤(d7s-d6m) / CT7≤2.53; Wherein, d7s is the inner diameter of the object side of the seventh spacer element, d6m is the inner diameter of the image side of the sixth spacer element, and CT7 is the thickness of the seventh lens on the optical axis.

9. The optical system according to claim 8, characterized in that, The optical system satisfies: 0.87≤EP78 / EP67≤1.87; Wherein, EP78 is the distance between the image side of the seventh spacer and the object side of the eighth spacer along the optical axis, and EP67 is the distance between the image side of the sixth spacer and the object side of the seventh spacer along the optical axis.

10. The optical system according to claim 8 or 9, characterized in that, The optical system satisfies: 2.03 ≤ f6 / D6s ≤ 3.92; Where f6 is the effective focal length of the sixth lens, and D6s is the outer diameter of the object side of the sixth spacer element.

11. The optical system according to any one of claims 7-9, characterized in that, The optical system satisfies: 4.33≤f67 / (D7s-d7s)≤5.79; Wherein, f67 is the combined focal length of the sixth lens and the seventh lens, D7s is the outer diameter of the object side surface of the seventh spacer element, and d7s is the inner diameter of the object side surface of the seventh spacer element.

12. The optical system according to any one of claims 1-9, characterized in that, The optical system satisfies: 5.63 ≤ f1 / d1s ≤ 6.90; Where f1 is the effective focal length of the first lens, and d1s is the inner diameter of the object side surface of the first spacer element.

13. The optical system according to any one of claims 1-9, characterized in that, The optical system satisfies: 4.46≤|f8| / (D0s-d0s)≤5.51; Where f8 is the effective focal length of the eighth lens, D0s is the outer diameter of the object-side end of the lens barrel, and d0s is the inner diameter of the object-side end of the lens barrel.

14. The optical system according to any one of claims 1-9, characterized in that, The air gap between the fourth lens and the fifth lens on the optical axis is not less than the air gap between any two adjacent lenses. The optical system satisfies: 2.99≤(L-ΣCT) / T45≤4.22; Where L is the maximum height of the lens barrel, ∑CT is the sum of the thicknesses of the first lens to the eighth lens on the optical axis, and T45 is the air gap between the fourth lens and the fifth lens on the optical axis.

Images