Optical systems and electronic devices

Abstract

This application provides an optical system and an electronic device. The optical system includes lens groups, comprising a first lens group, a second lens group, and a third lens group. The first lens group includes a first lens, a second lens, a third lens, and a fourth lens; the second lens group includes a fifth lens, a sixth lens, a seventh lens, and an eighth lens; and the third lens group includes a ninth lens, a tenth lens, an eleventh lens, and a twelfth lens. The first and second lenses are cemented together, the sixth and seventh lenses are cemented together, and the ninth and tenth lenses are cemented together, satisfying the following conditions: -16.46 ≤ f9 / CT9 ≤ -13.80; 1.80 < f10 / CT10 < 2.65; 3.20 ≤ FG2 / FG3 < 3.65. This optical system achieves a balance between high image quality, compactness, and environmental reliability for external telephoto lenses.

Description

Technical Field

[0001] This application relates to the field of optics, and more specifically, to an optical system and an electronic device. Background Technology

[0002] In today's era of mobile photography, users' demands for high image quality and creative freedom continue to grow. Due to the limited internal space of mobile phones, the physical focal length, aperture, and aberration correction capabilities of their built-in telephoto lenses all face bottlenecks. While computational photography can compensate for these limitations, it cannot replace the image quality improvements brought by native optical information. Therefore, the market needs an external lens accessory that can work in conjunction with the high-quality main camera of a mobile phone, significantly extend the optical focal length, and without compromising image quality. Summary of the Invention

[0003] One aspect of this application provides an optical system including a lens group. The lens group sequentially includes a first lens group, a second lens group, and a third lens group along the optical axis from the object side to the image side. The first lens group has positive optical power and includes: a first lens with positive optical power, the object side of which is convex, and the image side of which is convex; a second lens with negative optical power, the object side of which is concave; a third lens with positive optical power; and a fourth lens with either positive or negative optical power, the object side of which is planar. The third lens... The image-side surface of the fourth lens and the object-side surface of the fourth lens are diffraction surfaces, or the image-side surface of the fourth lens is a diffraction surface; the second lens group has positive optical power, and the second lens group includes: a fifth lens with positive optical power, the object-side surface of the fifth lens being convex and the image-side surface of the fifth lens being convex; a sixth lens with positive optical power, the object-side surface of the sixth lens being convex and the image-side surface of the sixth lens being convex; a seventh lens with negative optical power, the object-side surface of the seventh lens being concave and the image-side surface of the seventh lens being concave; and an eighth lens with either positive or negative optical power, the eighth lens... The object-side surface of the eighth lens is concave, and the image-side surface of the eighth lens is convex. The third lens group has positive optical power and includes: a ninth lens with negative optical power, the object-side surface of the ninth lens being concave and the image-side surface of the ninth lens being concave; a tenth lens with positive optical power, the object-side surface of the tenth lens being convex and the image-side surface of the tenth lens being convex; an eleventh lens with positive optical power, the image-side surface of the eleventh lens being convex; and a twelfth lens with positive optical power, the object-side surface of the twelfth lens being convex and the image-side surface of the twelfth lens being convex; the first lens and the... The second lens is cemented together, the sixth lens and the seventh lens are cemented together, and the ninth lens and the tenth lens are cemented together; the optical system satisfies: -16.46≤f9 / CT9≤-13.80; 1.80<f10 / CT10<2.65; 3.20≤FG2 / FG3<3.65, where f9 is the effective focal length of the ninth lens, CT9 is the center thickness of the ninth lens, f10 is the effective focal length of the tenth lens, CT10 is the center thickness of the tenth lens, FG2 is the combined focal length of the second lens group, and FG3 is the combined focal length of the third lens group.

[0004] According to an embodiment of this application, the radius of curvature R1 of the object side of the first lens, the radius of curvature R4 of the image side of the second lens, and the combined focal length F12 of the first lens and the second lens satisfy: 0.10≤|R1+R4| / F12≤2.89.

[0005] According to an embodiment of this application, the center thickness CT1 of the first lens, the center thickness CT2 of the second lens, the center thickness CT3 of the third lens, and the center thickness CT4 of the fourth lens satisfy: 1.35 < (CT1 + CT2) / (CT3 + CT4) ≤ 1.75.

[0006] According to an embodiment of this application, the combined focal length F67 of the sixth lens and the seventh lens and the center thickness CT7 of the seventh lens satisfy: -11.08≤F67 / CT7≤-8.09.

[0007] According to an embodiment of this application, the effective focal length f of the optical system and the air gap T89 between the eighth lens and the ninth lens on the optical axis satisfy: -10.44≤f / T89≤-6.32.

[0008] According to an embodiment of this application, the combined focal length F910 of the ninth lens and the tenth lens, the effective focal length f11 of the eleventh lens, and the effective focal length f12 of the twelfth lens satisfy: 1.55≤|F910| / (f11+f12)≤5.05.

[0009] According to an embodiment of this application, the axial distance TD between the object side of the first lens and the image side of the twelfth lens, and the combined focal length F91011 of the ninth lens, the tenth lens, and the eleventh lens satisfy: 2.20 < TD / F91011 ≤ 2.60.

[0010] According to an embodiment of this application, the combined focal length FG1 of the first lens group and the combined focal length FG3 of the third lens group satisfy: 4.90 < FG1 / FG3 < 5.30.

[0011] According to an embodiment of this application, the radius of curvature R9 of the object side of the fifth lens, the radius of curvature R10 of the image side of the fifth lens, and the effective focal length f5 of the fifth lens satisfy: -5.45 < (R9 + R10) / f5 < -3.00.

[0012] According to an embodiment of this application, the radius of curvature R11 of the object side of the sixth lens, the radius of curvature R12 of the image side of the sixth lens, and the center thickness CT6 of the sixth lens satisfy: -4.00≤(R11+R12) / CT6≤-2.70.

[0013] According to an embodiment of this application, the combined focal length FG2 of the second lens group, the center thickness CT5 of the fifth lens, and the center thickness CT8 of the eighth lens satisfy: 5.70 < FG2 / (CT5+CT8) < 6.35.

[0014] According to an embodiment of this application, the effective focal length f2 of the second lens, the effective focal length f6 of the sixth lens, and the effective focal length f7 of the seventh lens satisfy: -6.76≤f2 / (f6+f7)≤-4.70.

[0015] According to an embodiment of this application, the air gap T45 between the fourth lens and the fifth lens on the optical axis and the air gap T78 between the seventh lens and the eighth lens on the optical axis satisfy: 6.85≤T45 / T78≤7.55.

[0016] According to an embodiment of this application, the sum of the air gaps ∑AT between adjacent lenses in the first lens to the twelfth lens on the optical axis and the air gap T1112 between the eleventh lens and the twelfth lens on the optical axis satisfy: 4.88≤∑AT / T1112≤9.48.

[0017] According to an embodiment of this application, the sum of the center thicknesses of all lenses from the first lens to the twelfth lens, ∑CT, the effective radius of the object side of the first lens, DT11, and the effective radius of the image side of the twelfth lens, DT122, satisfy: 2.00 < ∑CT / (DT11+DT122) < 2.40.

[0018] According to an embodiment of this application, the optical system further includes an imaging lens and an imaging surface located on the image side of the twelfth lens, wherein the outgoing light beam of the lens group enters the imaging lens to form an image on the imaging surface using the imaging lens.

[0019] Another aspect of this application provides an electronic device including the optical system provided in any embodiment of this application.

[0020] According to the technical solution of this application embodiment, this optical system is reasonably configured. Through the coordinated constraints of three conditions—-16.46≤f9 / CT9≤-13.80, 1.80<f10 / CT10<2.65, and 3.20≤FG2 / FG3<3.65—a balance is achieved between high image quality, compactness, and environmental reliability for the external telephoto lens. The lower limit ensures that the ninth and tenth lenses provide the necessary optical power in the cemented group, and that the second lens group undertakes the main contribution of optical power, laying the foundation for achieving a long focal length, maintaining the system's optical power balance, and providing key compensation for correcting system field curvature and astigmatism. The upper limit constrains its thickness and curvature, optimizes the aberration correction effect of the cemented surface, and controls the volume of the front group. At the same time, the distribution of optical power between groups is optimized, the aberrations of each group are balanced, the rationality of the total system length and back working distance is ensured, and a margin is reserved for the thermal stability of the overall structure. Attached Figure Description

[0021] Other features, objects, and advantages of this application will become more apparent from the following detailed description of non-limiting embodiments, taken in conjunction with the accompanying drawings. In the drawings:

[0022] Figure 1 This application provides a schematic diagram of the overall architecture of an optical system.

[0023] Figure 2 A schematic diagram of the lens assembly of Embodiment 1 provided in this application is shown;

[0024] Figure 3 A schematic diagram of the on-axis chromatic aberration curve of the optical system of Embodiment 1 is shown;

[0025] Figure 4 A schematic diagram of the astigmatism curve of the optical system of Embodiment 1 is shown;

[0026] Figure 5 A schematic diagram of the distortion curve of the optical system in Embodiment 1 is shown;

[0027] Figure 6 A schematic diagram of the lens assembly of Embodiment 2 provided in this application is shown;

[0028] Figure 7 A schematic diagram of the on-axis chromatic aberration curve of the optical system of Embodiment 2 is shown;

[0029] Figure 8 A schematic diagram of the astigmatism curve of the optical system in Embodiment 2 is shown;

[0030] Figure 9 A schematic diagram of the distortion curve of the optical system in Embodiment 2 is shown;

[0031] Figure 10 A schematic diagram of the lens assembly of Embodiment 3 provided in this application is shown;

[0032] Figure 11 A schematic diagram of the on-axis chromatic aberration curve of the optical system of Embodiment 3 is shown;

[0033] Figure 12 A schematic diagram of the astigmatism curve of the optical system in Embodiment 3 is shown;

[0034] Figure 13 A schematic diagram of the distortion curve of the optical system in Embodiment 3 is shown;

[0035] Figure 14 A schematic diagram of the lens assembly of Embodiment 4 provided in this application is shown;

[0036] Figure 15 A schematic diagram of the on-axis chromatic aberration curve of the optical system of Embodiment 4 is shown;

[0037] Figure 16 A schematic diagram of the astigmatism curve of the optical system of Embodiment 4 is shown;

[0038] Figure 17 A schematic diagram of the distortion curve of the optical system in Embodiment 4 is shown;

[0039] Figure 18 A schematic diagram of the lens assembly of Embodiment 5 provided in this application is shown;

[0040] Figure 19 A schematic diagram of the on-axis chromatic aberration curve of the optical system of Embodiment 5 is shown;

[0041] Figure 20 A schematic diagram of the astigmatism curve of the optical system of Embodiment 5 is shown; and

[0042] Figure 21 A schematic diagram of the distortion curve of the optical system in Embodiment 5 is shown. Detailed Implementation

[0043] 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.

[0044] It should be noted that in this specification, the terms "first," "second," 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, and the second lens may also be referred to as the first lens.

[0045] 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.

[0046] In this paper, the paraxial region refers to the region near the optical axis. If the lens surface is convex and the location of the convexity is not defined, it means that the lens surface is convex at least in the paraxial region; if the lens surface is concave and the location of the concaveness is not defined, it means that the lens surface is concave at least in the paraxial region.

[0047] 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.

[0048] 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 a 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.

[0049] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0050] The features, principles and other aspects of this application are described in detail below.

[0051] This application provides an optical system comprising a lens group, wherein the lens group comprises a first lens group, a second lens group, and a third lens group in sequence from the object side to the image side along the optical axis.

[0052] The first lens group has positive optical power and includes: a first lens with positive optical power, the object side of the first lens being convex and the image side of the first lens being convex; a second lens with negative optical power, the object side of the second lens being concave; a third lens with positive optical power; and a fourth lens with either positive or negative optical power, the object side of the fourth lens being planar, and the image side of the third lens and the object side of the fourth lens being diffraction surfaces, or the image side of the fourth lens being a diffraction surface.

[0053] The second lens group has positive optical power and includes: a fifth lens with positive optical power, the object side of the fifth lens being convex and the image side of the fifth lens being convex; a sixth lens with positive optical power, the object side of the sixth lens being convex and the image side of the sixth lens being convex; a seventh lens with negative optical power, the object side of the seventh lens being concave and the image side of the seventh lens being concave; and an eighth lens with either positive or negative optical power, the object side of the eighth lens being concave and the image side of the eighth lens being convex.

[0054] The third lens group has positive optical power and includes: a ninth lens with negative optical power, the object side of the ninth lens being concave and the image side of the ninth lens being concave; a tenth lens with positive optical power, the object side of the tenth lens being convex and the image side of the tenth lens being convex; an eleventh lens with positive optical power, the image side of the eleventh lens being convex; and a twelfth lens with positive optical power, the object side of the twelfth lens being convex and the image side of the twelfth lens being convex.

[0055] The first and second lenses are cemented together, the sixth and seventh lenses are cemented together, and the ninth and tenth lenses are cemented together. The optical system satisfies: -16.46≤f9 / CT9≤-13.80; 1.80<f10 / CT10<2.65; 3.20≤FG2 / FG3<3.65, where f9 is the effective focal length of the ninth lens, CT9 is the center thickness of the ninth lens, f10 is the effective focal length of the tenth lens, CT10 is the center thickness of the tenth lens, FG2 is the combined focal length of the second lens group, and FG3 is the combined focal length of the third lens group.

[0056] The embodiments provided in this application, through the reasonable configuration of this optical system and the synergistic constraints of three conditions—-16.46≤f9 / CT9≤-13.80, 1.80<f10 / CT10<2.65, and 3.20≤FG2 / FG3<3.65—achieve a balance between high image quality, compactness, and environmental reliability for the external telephoto lens. The lower limit ensures that the ninth and tenth lenses provide the necessary optical power in the cemented group, and that the second lens group contributes the main optical power, laying the foundation for achieving a long focal length, maintaining the system's optical power balance, and providing crucial compensation for correcting system field curvature and astigmatism. The upper limit constrains its thickness and curvature, optimizing the aberration correction effect of the cemented surface and controlling the volume of the front group. Simultaneously, it optimizes the distribution of optical power between groups, balances the aberrations of each element, ensures the rationality of the system's total length and back working distance, and reserves a margin for the overall structural thermal stability.

[0057] In an exemplary embodiment, the optical system provided in this application may further include an imaging lens and an imaging surface located on the image side of the twelfth lens, wherein the outgoing light beam of the lens group enters the imaging lens to form an image on the imaging surface using the imaging lens.

[0058] In some embodiments of this application, the imaging lens can be the native lens of an electronic device (e.g., a mobile phone, a tablet computer), and the lens group can refer to a teleconverter or an external lens accessory. The imaging lens is a core optical component located behind the lens group and adjacent to the image sensor along the optical axis. It is used to finally converge the light rays corrected and optimized by the front lens group to form a clear and usable real image on the imaging surface. For example, the native lens of a mobile phone can be used to converge the light rays from the teleconverter, ultimately forming an image on the imaging surface. The imaging surface is, for example, the photosensitive surface of an image sensor.

[0059] In an exemplary embodiment, the radius of curvature R1 of the object-side surface of the first lens, the radius of curvature R4 of the image-side surface of the second lens, and the combined focal length F12 of the first and second lenses satisfy: 0.10 ≤ |R1 + R4| / F12 ≤ 2.89. This embodiment reasonably controls the range of this conditional expression, achieving control over the optical characteristics of the front cemented lens group, laying the foundation for the optical system to achieve superior chromatic aberration correction and stable imaging quality. The lower limit of this conditional expression ensures that the cemented assembly composed of the first and second lenses has sufficient curvature, providing the necessary structural basis for efficiently correcting axial and magnification chromatic aberration by utilizing the different dispersion characteristics of the materials on both sides of the cemented interface, and ensuring an effective contribution to the optical power of the optical system. The upper limit of this conditional expression effectively constrains the overall curvature of the cemented assembly, preventing the generation of difficult-to-correct advanced spherical aberration due to excessively large curvature radii, and reducing the process sensitivity of the processing and assembly of the first and second lenses, ensuring mass production stability.

[0060] In an exemplary embodiment, the center thickness CT1 of the first lens, the center thickness CT2 of the second lens, the center thickness CT3 of the third lens, and the center thickness CT4 of the fourth lens satisfy: 1.35 < (CT1 + CT2) / (CT3 + CT4) ≤ 1.75. This embodiment reasonably controls the range of this conditional expression, achieving an optimized allocation of the thickness distribution within the first lens group, thereby achieving the best balance between structural stability, optical power contribution, and system compactness. The lower limit of this conditional expression ensures that its overall thickness is sufficient to maintain the necessary structural rigidity and optical path length, which provides a basis for effective chromatic aberration correction of the cemented surface, while enabling the cemented group to contribute sufficient optical power and assume the core role of converging light in the front group; the upper limit of this conditional expression effectively constrains the overall thickness of the first two lenses, preventing them from excessively occupying axial space, thereby ensuring that light can smoothly transition to the subsequent third and fourth lenses. This controls the overall system length and reserves a reasonable optical working distance for the diffraction surface to participate in aberration correction, which is conducive to the compact design of the entire lens.

[0061] In an exemplary embodiment, the combined focal length F67 of the sixth and seventh lenses and the center thickness CT7 of the seventh lens satisfy: -11.08 ≤ F67 / CT7 ≤ -8.09. This embodiment reasonably controls the range of this conditional expression, achieving control over the key negative optical power lens in the second lens group, thereby optimizing the balance between aberration correction, system optical power balance, and environmental stability. The lower limit of this conditional expression is crucial for balancing the positive field curvature generated by the front positive lens group, while providing the necessary design freedom for correcting axial chromatic aberration. The upper limit of this conditional expression constrains the implementation of this negative optical power, thereby effectively suppressing the generated advanced spherical aberration and significantly improving the manufacturability of the lens and the dimensional stability of the cemented assembly under temperature changes, ensuring the environmental reliability of mass-produced lenses.

[0062] In an exemplary embodiment, the effective focal length f of the optical system and the air gap T89 between the eighth and ninth lenses on the optical axis satisfy: -10.44 ≤ f / T89 ≤ -6.32. This embodiment reasonably controls the range of this conditional expression, optimizing the critical air gap between lens groups, thereby achieving a balance between aberration correction, optical path conversion efficiency, and overall system length control. The lower limit of this conditional expression provides crucial physical space for the gradual change of the light angle between the second and third lens groups and for further aberration correction, while also reserving margin for the layout and heat dissipation of the internal mechanical structure of the lens barrel. The upper limit of this conditional expression effectively constrains this gap, preventing it from increasing excessively and unnecessarily increasing the overall system length, compromising overall compactness, and ensuring high light transmission efficiency between the two lens groups, avoiding stray light risks and light transmission efficiency losses due to excessively long optical paths.

[0063] In an exemplary embodiment, the combined focal length F910 of the ninth and tenth lenses, the effective focal length f11 of the eleventh lens, and the effective focal length f12 of the twelfth lens satisfy: 1.55 ≤ |F910| / (f11+f12) ≤ 5.05. This embodiment reasonably controls the range of this conditional expression, achieving global optimization of the optical power distribution of the rear group of the system, thereby achieving a balance between image field flattening, rear working distance control, and overall system length convergence. The lower limit of this conditional expression ensures that the cemented assembly has sufficient optical power to effectively counteract the positive field curvature generated by the front positive lens group, thereby obtaining a flat image plane, while creating conditions for obtaining a longer rear working distance, which is beneficial for physical adaptation with the native lens. The upper limit of this conditional expression avoids the cemented assembly itself from generating difficult-to-correct aberrations such as advanced astigmatism due to excessive curvature, and ensures that the subsequent positive lens group can fully play its core role in converging light, so that the overall system length can be effectively controlled and the structure can be compacted.

[0064] In an exemplary embodiment, the axial distance TD between the object-side surface of the first lens and the image-side surface of the twelfth lens, and the combined focal length F91011 of the ninth, tenth, and eleventh lenses, satisfy: 2.20 < TD / F91011 ≤ 2.60. This embodiment reasonably controls the range of this conditional expression, achieving global optimization of the overall system length and the optical power of the rear group, thereby achieving a balance between aberration correction capability and compactness. The lower limit of this conditional expression ensures that the system still has reasonable physical space to accommodate all lenses and realize complex refractive and diffractive hybrid optical paths while pursuing miniaturization. This provides crucial design freedom for the rear group lenses to perform their aberration correction function and reserves a safety margin for necessary mechanical spacing and heat dissipation between lenses. The upper limit of this conditional expression constrains the overall system length, requiring the ninth, tenth, and eleventh lenses to contribute optical power efficiently, thereby ensuring the portability of the overall size of the external lens while achieving the predetermined optical performance, and reducing the processing and assembly sensitivity caused by the length of the structure.

[0065] In an exemplary embodiment, the combined focal length FG1 of the first lens group and the combined focal length FG3 of the third lens group satisfy: 4.90 < FG1 / FG3 < 5.30. This embodiment reasonably controls the range of this conditional expression, achieving global optimization of the optical power distribution between the first and third lens groups, thereby establishing a balance between initial light control, overall aberration balance, and structural stability. The lower limit of this conditional expression ensures that light entering the optical system converges at a gentle angle initially, effectively controlling the generation of advanced spherical and coma aberrations, and providing a good starting point for aberration correction for the entire system. The upper limit of this conditional expression constrains the optical power of the first lens group, preventing it from excessively transferring all light bending and aberration correction pressure to the subsequent groups due to insufficient contribution. This avoids the third lens group being forced to adopt an extreme design to compensate, helping to reduce the overall system sensitivity and improve processing and assembly yield.

[0066] In an exemplary embodiment, the radius of curvature R9 of the object-side surface of the fifth lens, the radius of curvature R10 of the image-side surface of the fifth lens, and the effective focal length f5 of the fifth lens satisfy: -5.45 < (R9 + R10) / f5 < -3.00. This embodiment reasonably controls the range of this conditional expression, achieving control over the curvature of the fifth lens surface, thereby establishing an optimized balance between its optical power contribution, aberration correction efficiency, and manufacturing feasibility. The lower limit of this conditional expression ensures the curvature of the fifth lens, enabling it to effectively participate in correcting astigmatism and field curvature generated by the front lens while contributing positive optical power and maintaining good light guiding ability. The upper limit of this conditional expression prevents the introduction of difficult-to-correct advanced spherical aberrations and significantly reduces the difficulty and sensitivity of lens forming (especially molding processes), ensuring consistency in mass production.

[0067] In an exemplary embodiment, the radius of curvature R11 of the object-side surface of the sixth lens, the radius of curvature R12 of the image-side surface of the sixth lens, and the center thickness CT6 of the sixth lens satisfy: -4.00 ≤ (R11 + R12) / CT6 ≤ -2.70. This embodiment reasonably controls the range of this conditional expression, achieving synergistic optimization of the shape and thickness of the sixth lens, thereby establishing a balance between its optical power contribution, aberration correction efficiency, and structural stability. The lower limit of this conditional expression ensures the curvature of the sixth lens, enabling it to provide the necessary positive optical power and effectively participate in correcting astigmatism generated by the preceding lens, while providing optimized interface conditions for bonding with the seventh lens to correct chromatic aberration. The upper limit of this conditional expression ensures structural strength and temperature stability, avoiding the introduction of difficult-to-correct advanced spherical aberrations, thereby guaranteeing performance reliability and mass production yield.

[0068] In an exemplary embodiment, the combined focal length FG2 of the second lens group, the center thickness CT5 of the fifth lens, and the center thickness CT8 of the eighth lens satisfy: 5.70 < FG2 / (CT5+CT8) < 6.35. This embodiment reasonably controls the range of this conditional expression, achieving global optimization of the optical performance and physical volume of the second lens group, thereby establishing a balance between optical power contribution, system miniaturization, and structural stability. The lower limit of this conditional expression ensures that the second lens group has sufficiently strong optical power to undertake the main zoom and light-gathering tasks of the system, laying the foundation for achieving long focal lengths. The upper limit of this conditional expression prevents excessive optical power from causing difficulties in aberration correction and ensures that key lenses have the necessary minimum safe thickness, thereby maintaining the structural strength and manufacturing feasibility of the lenses, and improving the overall system's resistance to environmental changes and mass production yield.

[0069] In an exemplary embodiment, the effective focal length f2 of the second lens, the effective focal length f6 of the sixth lens, and the effective focal length f7 of the seventh lens satisfy: -6.76 ≤ f2 / (f6+f7) ≤ -4.70. This embodiment reasonably controls the range of this conditional expression, achieving control over the intensity ratio between key lenses in the optical system, thereby establishing a systematic balance between chromatic aberration correction, image field flattening, and optical path structural stability. The lower limit of this conditional expression ensures that the system has the necessary capability to correct axial chromatic aberration, effectively balances the positive field curvature generated by the front positive lens, lays the foundation for obtaining a flat image plane, and helps to extend the back working distance. The upper limit of this conditional expression effectively suppresses the advanced astigmatism and coma that may be caused by this, reduces the sensitivity of the cemented surface, and improves the robustness of the overall optical path in assembly and use.

[0070] In an exemplary embodiment, the air gap T45 between the fourth and fifth lenses on the optical axis and the air gap T78 between the seventh and eighth lenses on the optical axis satisfy: 6.85 ≤ T45 / T78 ≤ 7.55. This embodiment reasonably controls the range of this conditional expression, achieving synergistic optimization of the two key air gaps within the front and middle lens groups, thereby establishing a balance between optical path conversion efficiency, aberration correction freedom, and system compactness. The lower limit of this conditional expression ensures a sufficient distance between the fourth and fifth lenses that is significantly greater than the intra-group gap. This provides the necessary space for light to perform angle conversion and beam expansion between lens groups, which is beneficial for smoothing astigmatism and field curvature, and creates a low-interference environment for the efficient operation of the diffraction surface. The upper limit of this conditional expression constrains the excessive increase of this gap, preventing it from excessively encroaching on the space of subsequent lenses, ensuring that the seventh and eighth lenses in the second lens group can maintain tight optical coupling to effectively perform their specific aberration correction functions, thereby giving design freedom while strictly shortening the overall system length.

[0071] In an exemplary embodiment, the sum of the air gaps ∑AT between adjacent lenses on the optical axis from the first lens to the twelfth lens, and the air gap T1112 between the eleventh and twelfth lenses on the optical axis, satisfy: 4.88 ≤ ∑AT / T1112 ≤ 9.48. This embodiment reasonably controls the range of this conditional expression, achieving global optimization of the overall air gap distribution and the critical working space of the rear group, thereby establishing a balance between aberration correction capability, mechanical structural stability, and overall compactness. The lower limit of this conditional expression ensures the critical structural guarantee that each lens group can independently correct aberrations without mutual interference, and also provides a physical basis for the internal mechanical support and heat dissipation design of the lens barrel. The upper limit of this conditional expression ensures that the rear lens group has independent and sufficient working space to play its core role in converging light and ultimately balancing aberrations, avoiding insufficient rear working distance or decreased image quality due to excessive compression of the rear group space. Thus, while providing overall design flexibility, it ensures the performance stability and feasibility of the system's end structure.

[0072] In an exemplary embodiment, the sum of the center thicknesses of all lenses from the first lens to the twelfth lens, ∑CT, the effective radius DT11 of the object-side surface of the first lens, and the effective radius DT122 of the image-side surface of the twelfth lens satisfy: 2.00 < ∑CT / (DT11 + DT122) < 2.40. This embodiment reasonably controls the range of this conditional expression, achieving global optimization of the ratio of the overall material volume to the light transmission aperture of the system, thereby establishing a balance between structural rigidity, light throughput, and extreme compactness. The lower limit of this conditional expression ensures that the sum of the center thicknesses of all lenses is sufficiently significant relative to the system's entrance and exit pupil apertures. This provides the necessary material volume for the twelve lenses to maintain the overall structural rigidity and thermal stability, and provides a solid physical basis for handling complex surface shapes and bonding processes. The upper limit of this conditional expression strictly constrains the total material volume, preventing the system from compromising portability due to excessive weight, and requires the optical path design to make efficient use of the aperture, ensuring sufficient light intake at the edge of the field of view and image illuminance while driving the system towards a thinner and lighter physical form.

[0073] Figure 1 A schematic diagram of the overall architecture of an optical system provided in this application is shown.

[0074] like Figure 1 As shown, the optical system includes a lens group 10 and an imaging lens 20. The lens group 10 and the imaging lens 20 are arranged sequentially from the object side to the image side along the optical axis. The imaging lens 20 is adjacent to the imaging surface IMG. The imaging surface IMG is, for example, the photosensitive surface of an image sensor.

[0075] The lens group 10 includes a first lens group G1, a second lens group G2, and a third lens group G3. The first lens group G1 has positive optical power, the second lens group G2 has positive optical power, and the third lens group G3 has positive optical power.

[0076] The first lens group G1 includes a first lens E1, a second lens E2, a third lens E3, and a fourth lens E4.

[0077] The first lens E1 has positive optical power, and the object side of the first lens E1 is convex, and the image side of the first lens E1 is convex.

[0078] The second lens E2 has negative optical power, and its object-side surface is concave. The third lens E3 has positive optical power.

[0079] The fourth lens E4 has either positive or negative optical power, and its object-side surface is a plane. The image-side surface of the third lens E3 and the object-side surface of the fourth lens E4 are diffraction surfaces, or the image-side surface of the fourth lens E4 is a diffraction surface.

[0080] The second lens group G2 includes the fifth lens E5, the sixth lens E6, the seventh lens E7, and the eighth lens E8.

[0081] The fifth lens E5 has positive optical power, and the object side and image side of the fifth lens E5 are both convex.

[0082] The sixth lens E6 has positive optical power, and the object side and image side of the sixth lens E6 are both convex.

[0083] The seventh lens E7 has negative optical power, and the object side and image side of the seventh lens E7 are both concave.

[0084] The eighth lens E8 has positive or negative optical power, and the object side of the eighth lens E8 is concave, while the image side of the eighth lens E8 is convex.

[0085] The third lens group G3 includes the ninth lens E9, the tenth lens E10, the eleventh lens E11, and the twelfth lens E12.

[0086] The ninth lens E9 has negative optical power. The object side of the ninth lens E9 is concave, and the image side of the ninth lens E9 is also concave.

[0087] The tenth lens E10 has positive optical power. The object side of the tenth lens E10 is convex, and the image side of the tenth lens E10 is also convex.

[0088] The eleventh lens E11 has positive optical power, and the image-side surface of the eleventh lens E11 is convex.

[0089] The twelfth lens E12 has positive optical power. The object side of the twelfth lens E12 is convex, and the image side of the twelfth lens E12 is also convex.

[0090] The first lens E1 and the second lens E2 are cemented together, the sixth lens E6 and the seventh lens E7 are cemented together, and the ninth lens E9 and the tenth lens E10 are cemented together; and the optical system satisfies: -16.46≤f9 / CT9≤-13.80; 1.80<f10 / CT10<2.65; 3.20≤FG2 / FG3<3.65, where f9 is the effective focal length of the ninth lens E9, CT9 is the center thickness of the ninth lens E9, f10 is the effective focal length of the tenth lens E10, CT10 is the center thickness of the tenth lens E10, FG2 is the combined focal length of the second lens group G2, and FG3 is the combined focal length of the third lens group G3.

[0091] For example, light from an object passes sequentially through the corresponding surfaces of the first lens group G1, the second lens group G2, the third lens group G3, and the imaging lens 20, and is finally imaged on the imaging surface IMG.

[0092] The following description, with reference to the accompanying drawings, further illustrates examples of the specific surface shape and parameters of the lens group 10 applicable to the above embodiments.

[0093] Example 1

[0094] The following is for reference Figures 2-5 The lens assembly 10 according to Embodiment 1 of this application is described. Figure 2 A schematic diagram of the lens group 10 according to Embodiment 1 of this application is shown. Embodiment 1 includes 12 lenses, and the effective focal length f of the optical system is the effective focal length when adapted to an imaging lens with a focal length of 22.48mm.

[0095] like Figure 2 As shown, the lens group 10 includes a first lens group G1, a second lens group G2, and a third lens group G3.

[0096] The first lens group G1 includes a first lens E1, a second lens E2, a third lens E3, and a fourth lens E4.

[0097] The first lens E1 has positive optical power, the object side S1 of the first lens E1 is convex, and the image side S2 of the first lens E1 is convex.

[0098] The second lens E2 has negative optical power, and the object side S2 of the second lens E2 is concave, while the image side S3 of the second lens E2 is concave.

[0099] The third lens E3 has positive optical power, the object side S4 of the third lens E3 is convex, and the image side S5 of the third lens E3 is convex.

[0100] The fourth lens E4 has positive optical power, and the object side S6 of the fourth lens E4 is a plane, and the image side S7 of the fourth lens E4 is a plane.

[0101] The image-side surface S7 of the fourth lens E4 is a diffraction surface.

[0102] The second lens group G2 includes the fifth lens E5, the sixth lens E6, the seventh lens E7, and the eighth lens E8.

[0103] The fifth lens E5 has positive optical power, and the object side S8 of the fifth lens E5 is convex, and the image side S9 of the fifth lens E5 is convex.

[0104] The sixth lens E6 has positive optical power, and the object side S10 of the sixth lens E6 is convex, and the image side S11 of the sixth lens E6 is convex.

[0105] The seventh lens E7 has negative optical power, and the object side S11 of the seventh lens E7 is concave, while the image side S12 of the seventh lens E7 is concave.

[0106] The eighth lens E8 has positive optical power, and the object side S13 of the eighth lens E8 is concave, while the image side S14 of the eighth lens E8 is convex.

[0107] The third lens group G3 includes the ninth lens E9, the tenth lens E10, the eleventh lens E11, and the twelfth lens E12.

[0108] The ninth lens E9 has negative optical power. The object side S15 of the ninth lens E9 is concave, and the image side S16 of the ninth lens E9 is concave.

[0109] The tenth lens E10 has positive optical power. The object side S16 of the tenth lens E10 is convex, and the image side S17 of the tenth lens E10 is convex.

[0110] The eleventh lens E11 has positive optical power. The object-side surface S18 of the eleventh lens E11 is concave, and the image-side surface S19 of the eleventh lens E11 is convex.

[0111] The twelfth lens E12 has positive optical power. The object side S20 of the twelfth lens E12 is convex, and the image side S21 of the twelfth lens E12 is convex.

[0112] The first lens E1 and the second lens E2 are cemented together, the sixth lens E6 and the seventh lens E7 are cemented together, and the ninth lens E9 and the tenth lens E10 are cemented together.

[0113] For example, light from an object passes sequentially through the corresponding surfaces of the first lens group G1, the second lens group G2, the third lens group G3, and the imaging lens 20, and is finally imaged on the imaging surface IMG.

[0114] The basic parameters of the lens group 10 in the following embodiment are shown in Table 1 (unit: mm).

[0115] Table 1

[0116]

[0117] The phase equation for the diffraction plane in an optical system is expressed as follows:

[0118] , The phase profile is represented by d, and the diffraction order is represented by d. denoted by λ, where λ represents the reference wavelength, and r represents the radial coordinate.

[0119] Table 2 below shows the coefficients of the phase equation for the diffraction surface that can be used in this embodiment. In this embodiment, the image-side surface S7 of the fourth lens E4 is the diffraction surface (or "diffraction surface").

[0120] Table 2

[0121]

[0122] Figure 3 A schematic diagram of the on-axis chromatic aberration curve of the optical system of Embodiment 1 is shown. Figure 3 As shown, after passing through the optical system, the convergence focal point of light of different wavelengths deviates less.

[0123] Figure 4 A schematic diagram of the astigmatism curve of the optical system in Embodiment 1 is shown. (As...) Figure 4 As shown, the deviation between the meridional curve and the sagittal curve is small, therefore the astigmatism is small.

[0124] Figure 5 A schematic diagram of the distortion curve of the optical system in Embodiment 1 is shown. (As shown) Figure 5 As shown, the deviation is small, which ensures that there is no obvious distortion in the image.

[0125] according to Figure 3-5 As can be seen, the optical system given in Example 1 can achieve good imaging quality.

[0126] Example 2

[0127] The following is for reference Figures 6-9 The lens assembly 10 according to Embodiment 2 of this application is described. Figure 6 A schematic diagram of the lens group 10 according to Embodiment 2 of this application is shown. Embodiment 2 includes 12 lenses, and the effective focal length f of the optical system is the effective focal length when adapted to an imaging lens with a focal length of 22.48mm.

[0128] like Figure 6 As shown, the lens group 10 includes a first lens group G1, a second lens group G2, and a third lens group G3.

[0129] The first lens group G1 includes a first lens E1, a second lens E2, a third lens E3, and a fourth lens E4.

[0130] The first lens E1 has positive optical power, the object side S1 of the first lens E1 is convex, and the image side S2 of the first lens E1 is convex.

[0131] The second lens E2 has negative optical power, and the object side S2 of the second lens E2 is concave, while the image side S3 of the second lens E2 is concave.

[0132] The third lens E3 has positive optical power, the object side S4 of the third lens E3 is convex, and the image side S5 of the third lens E3 is flat.

[0133] The fourth lens E4 has positive optical power, and the object side S6 of the fourth lens E4 is flat, while the image side S7 of the fourth lens E4 is convex.

[0134] The image-side surface S5 of the third lens E3 and the object-side surface S6 of the fourth lens E4 are diffraction surfaces.

[0135] The second lens group G2 includes the fifth lens E5, the sixth lens E6, the seventh lens E7, and the eighth lens E8.

[0136] The fifth lens E5 has positive optical power, and the object side S8 of the fifth lens E5 is convex, and the image side S9 of the fifth lens E5 is convex.

[0137] The sixth lens E6 has positive optical power, and the object side S10 of the sixth lens E6 is convex, and the image side S11 of the sixth lens E6 is convex.

[0138] The seventh lens E7 has negative optical power, and the object side S11 of the seventh lens E7 is concave, while the image side S12 of the seventh lens E7 is concave.

[0139] The eighth lens E8 has negative optical power, and the object side S13 of the eighth lens E8 is concave, while the image side S14 of the eighth lens E8 is convex.

[0140] The third lens group G3 includes the ninth lens E9, the tenth lens E10, the eleventh lens E11, and the twelfth lens E12.

[0141] The ninth lens E9 has negative optical power. The object side S15 of the ninth lens E9 is concave, and the image side S16 of the ninth lens E9 is concave.

[0142] The tenth lens E10 has positive optical power. The object side S16 of the tenth lens E10 is convex, and the image side S17 of the tenth lens E10 is convex.

[0143] The eleventh lens E11 has positive optical power. The object-side surface S18 of the eleventh lens E11 is convex, and the image-side surface S19 of the eleventh lens E11 is convex.

[0144] The twelfth lens E12 has positive optical power. The object side S20 of the twelfth lens E12 is convex, and the image side S21 of the twelfth lens E12 is convex.

[0145] The first lens E1 and the second lens E2 are cemented together, the sixth lens E6 and the seventh lens E7 are cemented together, and the ninth lens E9 and the tenth lens E10 are cemented together.

[0146] For example, light from an object passes sequentially through the corresponding surfaces of the first lens group G1, the second lens group G2, the third lens group G3, and the imaging lens 20, and is finally imaged on the imaging surface IMG.

[0147] The basic parameters of lens group 10 in Embodiment 2 are shown in Table 3 (unit: mm).

[0148] Table 3

[0149]

[0150] The phase equation for the diffraction plane in an optical system is expressed as follows:

[0151] , The phase profile is represented by d, and the diffraction order is represented by d. denoted by λ, where λ represents the reference wavelength, and r represents the radial coordinate.

[0152] Table 4 below shows the coefficients of the phase equation for the diffraction surface that can be used in this embodiment. In this embodiment, the image-side surface S5 of the third lens E3 and the object-side surface S6 of the fourth lens E4 are diffraction surfaces (or "diffraction surfaces").

[0153] Table 4

[0154]

[0155] Figure 7 A schematic diagram of the on-axis chromatic aberration curve of the optical system of Embodiment 2 is shown. Figure 7 As shown, after passing through the optical system, the convergence focal point of light of different wavelengths deviates less.

[0156] Figure 8 A schematic diagram of the astigmatism curve of the optical system in Embodiment 2 is shown. (As shown...) Figure 8 As shown, the deviation between the meridional curve and the sagittal curve is small, therefore the astigmatism is small.

[0157] Figure 9 A schematic diagram of the distortion curve of the optical system in Embodiment 2 is shown. (As shown...) Figure 9 As shown, the deviation is small, which ensures that there is no obvious distortion in the image.

[0158] according to Figure 7-9 It can be seen that the optical system given in Example 2 can achieve good imaging quality.

[0159] Example 3

[0160] The following is for reference Figures 10-13 The lens assembly 10 according to Embodiment 3 of this application is described. Figure 10 A schematic diagram of the lens group 10 according to Embodiment 3 of this application is shown. Embodiment 3 includes 12 lenses, and the effective focal length f of the optical system is the effective focal length when adapted to an imaging lens with a focal length of 22.48mm.

[0161] like Figure 10 As shown, the lens group 10 includes a first lens group G1, a second lens group G2, and a third lens group G3.

[0162] The first lens group G1 includes a first lens E1, a second lens E2, a third lens E3, and a fourth lens E4.

[0163] The first lens E1 has positive optical power, the object side S1 of the first lens E1 is convex, and the image side S2 of the first lens E1 is convex.

[0164] The second lens E2 has negative optical power, and the object side S2 of the second lens E2 is concave, while the image side S3 of the second lens E2 is concave.

[0165] The third lens E3 has positive optical power, the object side S4 of the third lens E3 is convex, and the image side S5 of the third lens E3 is flat.

[0166] The fourth lens E4 has positive optical power, and the object side S6 of the fourth lens E4 is flat, while the image side S7 of the fourth lens E4 is convex.

[0167] The image-side surface S5 of the third lens E3 and the object-side surface S6 of the fourth lens E4 are diffraction surfaces.

[0168] The second lens group G2 includes the fifth lens E5, the sixth lens E6, the seventh lens E7, and the eighth lens E8.

[0169] The fifth lens E5 has positive optical power, and the object side S8 of the fifth lens E5 is convex, and the image side S9 of the fifth lens E5 is convex.

[0170] The sixth lens E6 has positive optical power, and the object side S10 of the sixth lens E6 is convex, and the image side S11 of the sixth lens E6 is convex.

[0171] The seventh lens E7 has negative optical power, and the object side S11 of the seventh lens E7 is concave, while the image side S12 of the seventh lens E7 is concave.

[0172] The eighth lens E8 has positive optical power, and the object side S13 of the eighth lens E8 is concave, while the image side S14 of the eighth lens E8 is convex.

[0173] The third lens group G3 includes the ninth lens E9, the tenth lens E10, the eleventh lens E11, and the twelfth lens E12.

[0174] The ninth lens E9 has negative optical power. The object side S15 of the ninth lens E9 is concave, and the image side S16 of the ninth lens E9 is concave.

[0175] The tenth lens E10 has positive optical power. The object side S16 of the tenth lens E10 is convex, and the image side S17 of the tenth lens E10 is convex.

[0176] The eleventh lens E11 has positive optical power. The object-side surface S18 of the eleventh lens E11 is convex, and the image-side surface S19 of the eleventh lens E11 is convex.

[0177] The twelfth lens E12 has positive optical power. The object side S20 of the twelfth lens E12 is convex, and the image side S21 of the twelfth lens E12 is convex.

[0178] The first lens E1 and the second lens E2 are cemented together, the sixth lens E6 and the seventh lens E7 are cemented together, and the ninth lens E9 and the tenth lens E10 are cemented together.

[0179] For example, light from an object passes sequentially through the corresponding surfaces of the first lens group G1, the second lens group G2, the third lens group G3, and the imaging lens 20, and is finally imaged on the imaging surface IMG.

[0180] The basic parameters of lens group 10 in Embodiment 3 are shown in Table 5 (unit: mm).

[0181] Table 5

[0182]

[0183] The phase equation for the diffraction plane in an optical system is expressed as follows:

[0184] , The phase profile is represented by d, and the diffraction order is represented by d. denoted by λ, where λ represents the reference wavelength, and r represents the radial coordinate.

[0185] Table 6 below shows the coefficients of the phase equation for the diffraction surface that can be used in this embodiment. In this embodiment, the image-side surface S5 of the third lens E3 and the object-side surface S6 of the fourth lens E4 are diffraction surfaces (or "diffraction surfaces").

[0186] Table 6

[0187]

[0188] Figure 11 A schematic diagram of the on-axis chromatic aberration curve of the optical system of Embodiment 3 is shown. Figure 11 As shown, after passing through the optical system, the convergence focal point of light of different wavelengths deviates less.

[0189] Figure 12 A schematic diagram of the astigmatism curve of the optical system in Embodiment 3 is shown. (As...) Figure 12 As shown, the deviation between the meridional curve and the sagittal curve is small, therefore the astigmatism is small.

[0190] Figure 13 A schematic diagram of the distortion curve of the optical system in Embodiment 3 is shown. (As shown) Figure 13 As shown, the deviation is small, which ensures that there is no obvious distortion in the image.

[0191] according to Figure 11-13 As can be seen, the optical system given in Example 3 can achieve good imaging quality.

[0192] Example 4

[0193] The following is for reference Figures 14-17 The lens assembly 10 according to Embodiment 4 of this application is described. Figure 14 A schematic diagram of the lens group 10 of Embodiment 4 provided in this application is shown. Embodiment 4 includes 12 lenses, and the effective focal length f of the optical system is the effective focal length when adapted to an imaging lens with a focal length of 22.48mm.

[0194] like Figure 14 As shown, the lens group 10 includes a first lens group G1, a second lens group G2, and a third lens group G3.

[0195] The first lens group G1 includes a first lens E1, a second lens E2, a third lens E3, and a fourth lens E4.

[0196] The first lens E1 has positive optical power, the object side S1 of the first lens E1 is convex, and the image side S2 of the first lens E1 is convex.

[0197] The second lens E2 has negative optical power, and the object side S2 of the second lens E2 is concave, while the image side S3 of the second lens E2 is concave.

[0198] The third lens E3 has positive optical power, the object side S4 of the third lens E3 is convex, and the image side S5 of the third lens E3 is flat.

[0199] The fourth lens E4 has positive optical power, and the object side S6 of the fourth lens E4 is flat, while the image side S7 of the fourth lens E4 is convex.

[0200] The image-side surface S5 of the third lens E3 and the object-side surface S6 of the fourth lens E4 are diffraction surfaces.

[0201] The second lens group G2 includes the fifth lens E5, the sixth lens E6, the seventh lens E7, and the eighth lens E8.

[0202] The fifth lens E5 has positive optical power, and the object side S8 of the fifth lens E5 is convex, and the image side S9 of the fifth lens E5 is convex.

[0203] The sixth lens E6 has positive optical power, and the object side S10 of the sixth lens E6 is convex, and the image side S11 of the sixth lens E6 is convex.

[0204] The seventh lens E7 has negative optical power, and the object side S11 of the seventh lens E7 is concave, while the image side S12 of the seventh lens E7 is concave.

[0205] The eighth lens E8 has positive optical power, and the object side S13 of the eighth lens E8 is concave, while the image side S14 of the eighth lens E8 is convex.

[0206] The third lens group G3 includes the ninth lens E9, the tenth lens E10, the eleventh lens E11, and the twelfth lens E12.

[0207] The ninth lens E9 has negative optical power. The object side S15 of the ninth lens E9 is concave, and the image side S16 of the ninth lens E9 is concave.

[0208] The tenth lens E10 has positive optical power. The object side S16 of the tenth lens E10 is convex, and the image side S17 of the tenth lens E10 is convex.

[0209] The eleventh lens E11 has positive optical power. The object-side surface S18 of the eleventh lens E11 is convex, and the image-side surface S19 of the eleventh lens E11 is convex.

[0210] The twelfth lens E12 has positive optical power. The object side S20 of the twelfth lens E12 is convex, and the image side S21 of the twelfth lens E12 is convex.

[0211] The first lens E1 and the second lens E2 are cemented together, the sixth lens E6 and the seventh lens E7 are cemented together, and the ninth lens E9 and the tenth lens E10 are cemented together.

[0212] For example, light from an object passes sequentially through the corresponding surfaces of the first lens group G1, the second lens group G2, the third lens group G3, and the imaging lens 20, and is finally imaged on the imaging surface IMG.

[0213] The basic parameters of lens group 10 in Embodiment 4 are shown in Table 7 (unit: mm).

[0214] Table 7

[0215]

[0216] The phase equation for the diffraction plane in an optical system is expressed as follows:

[0217] , The phase profile is represented by d, and the diffraction order is represented by d. denoted by λ, where λ represents the reference wavelength, and r represents the radial coordinate.

[0218] Table 8 below provides the coefficients of the phase equation for the diffraction surface that can be used in this embodiment. In this embodiment, the image-side surface S5 of the third lens E3 and the object-side surface S6 of the fourth lens E4 are diffraction surfaces (or "diffraction surfaces").

[0219] Table 8

[0220]

[0221] Figure 15 A schematic diagram of the on-axis chromatic aberration curve of the optical system of Embodiment 4 is shown. Figure 15 As shown, after passing through the optical system, the convergence focal point of light of different wavelengths deviates less.

[0222] Figure 16 A schematic diagram of the astigmatism curve of the optical system in Embodiment 4 is shown. Figure 16 As shown, the deviation between the meridional curve and the sagittal curve is small, therefore the astigmatism is small.

[0223] Figure 17 A schematic diagram of the distortion curve of the optical system in Embodiment 4 is shown. (As shown) Figure 17 As shown, the deviation is small, which ensures that there is no obvious distortion in the image.

[0224] according to Figure 15-17 As can be seen, the optical system given in Example 4 can achieve good imaging quality.

[0225] Example 5

[0226] The following is for reference Figures 18-21 The lens assembly 10 according to Embodiment 5 of this application is described. Figure 18 A schematic diagram of the lens group 10 according to Embodiment 5 of this application is shown. Embodiment 5 includes 12 lenses, and the effective focal length f of the optical system is the effective focal length when adapted to an imaging lens with a focal length of 22.48mm.

[0227] like Figure 18 As shown, the lens group 10 includes a first lens group G1, a second lens group G2, and a third lens group G3.

[0228] The first lens group G1 includes a first lens E1, a second lens E2, a third lens E3, and a fourth lens E4.

[0229] The first lens E1 has positive optical power, the object side S1 of the first lens E1 is convex, and the image side S2 of the first lens E1 is convex.

[0230] The second lens E2 has negative optical power, and the object side S2 of the second lens E2 is concave, while the image side S3 of the second lens E2 is convex.

[0231] The third lens E3 has positive optical power, the object side S4 of the third lens E3 is a plane, and the image side S5 of the third lens E3 is a plane.

[0232] The fourth lens E4 has negative optical power, and the object side S6 of the fourth lens E4 is a plane, and the image side S7 of the fourth lens E4 is a plane.

[0233] The image-side surface S5 of the third lens E3 and the object-side surface S6 of the fourth lens E4 are diffraction surfaces.

[0234] The second lens group G2 includes the fifth lens E5, the sixth lens E6, the seventh lens E7, and the eighth lens E8.

[0235] The fifth lens E5 has positive optical power, and the object side S8 of the fifth lens E5 is convex, and the image side S9 of the fifth lens E5 is convex.

[0236] The sixth lens E6 has positive optical power, and the object side S10 of the sixth lens E6 is convex, and the image side S11 of the sixth lens E6 is convex.

[0237] The seventh lens E7 has negative optical power, and the object side S11 of the seventh lens E7 is concave, while the image side S12 of the seventh lens E7 is concave.

[0238] The eighth lens E8 has positive optical power, and the object side S13 of the eighth lens E8 is concave, while the image side S14 of the eighth lens E8 is convex.

[0239] The third lens group G3 includes the ninth lens E9, the tenth lens E10, the eleventh lens E11, and the twelfth lens E12.

[0240] The ninth lens E9 has negative optical power. The object side S15 of the ninth lens E9 is concave, and the image side S16 of the ninth lens E9 is concave.

[0241] The tenth lens E10 has positive optical power. The object side S16 of the tenth lens E10 is convex, and the image side S17 of the tenth lens E10 is convex.

[0242] The eleventh lens E11 has positive optical power. The object-side surface S18 of the eleventh lens E11 is convex, and the image-side surface S19 of the eleventh lens E11 is convex.

[0243] The twelfth lens E12 has positive optical power. The object side S20 of the twelfth lens E12 is convex, and the image side S21 of the twelfth lens E12 is convex.

[0244] The first lens E1 and the second lens E2 are cemented together, the sixth lens E6 and the seventh lens E7 are cemented together, and the ninth lens E9 and the tenth lens E10 are cemented together.

[0245] For example, light from an object passes sequentially through the corresponding surfaces of the first lens group G1, the second lens group G2, the third lens group G3, and the imaging lens 20, and is finally imaged on the imaging surface IMG.

[0246] The basic parameters of lens group 10 in Embodiment 5 are shown in Table 9 (unit: mm).

[0247] Table 9

[0248]

[0249] The phase equation for the diffraction plane in an optical system is expressed as follows:

[0250] , The phase profile is represented by d, and the diffraction order is represented by d. denoted by λ, where λ represents the reference wavelength, and r represents the radial coordinate.

[0251] Table 10 below gives the coefficients of the phase equation for the diffraction surface that can be used in this embodiment. In this embodiment, the image-side surface S5 of the third lens E3 and the object-side surface S6 of the fourth lens E4 are diffraction surfaces (or "diffraction surfaces").

[0252] Table 10

[0253]

[0254] Figure 19 A schematic diagram of the on-axis chromatic aberration curve of the optical system of Embodiment 5 is shown. Figure 19 As shown, after passing through the optical system, the convergence focal point of light of different wavelengths deviates less.

[0255] Figure 20 A schematic diagram of the astigmatism curve of the optical system in Embodiment 5 is shown. (As...) Figure 20 As shown, the deviation between the meridional curve and the sagittal curve is small, therefore the astigmatism is small.

[0256] Figure 21 A schematic diagram of the distortion curve of the optical system in Embodiment 5 is shown. (As...) Figure 21 As shown, the deviation is small, which ensures that there is no obvious distortion in the image.

[0257] according to Figure 19-21 As can be seen, the optical system given in Example 5 can achieve good imaging quality.

[0258] Some optical parameters of the optical systems of Examples 1 to 5 are shown in Table 11 (unit: mm). The conditions satisfied by the optical systems of Examples 1 to 5 are shown in Table 12.

[0259] Table 11

[0260]

[0261] Table 12

[0262]

[0263] Furthermore, this application also provides an electronic device that includes the optical system provided in any embodiment of this application. The electronic device is, for example, a mobile phone, which may include an imaging lens and lens assemblies from various embodiments.

[0264] 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 protection 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 concept of this application. 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 group, wherein the lens group comprises, sequentially from the object side to the image side along the optical axis, a first lens group, a second lens group, and a third lens group, characterized in that, The first lens group has positive optical power, and the first lens group includes: A first lens having positive optical power, wherein the object-side surface of the first lens is convex and the image-side surface of the first lens is convex. A second lens having negative optical power, wherein the object side of the second lens is concave; A third lens with positive optical power; A fourth lens having positive or negative optical power, wherein the object-side surface of the fourth lens is a plane. Wherein, the image-side surface of the third lens and the object-side surface of the fourth lens are diffraction surfaces, or the image-side surface of the fourth lens is a diffraction surface; The second lens group has positive optical power, and the second lens group includes: A fifth lens with positive optical power, wherein the object-side surface of the fifth lens is convex and the image-side surface of the fifth lens is convex. A sixth lens having positive optical power, wherein the object-side surface of the sixth lens is convex and the image-side surface of the sixth lens is convex. A seventh lens with negative optical power, wherein the object-side surface of the seventh lens is concave and the image-side surface of the seventh lens is concave. An eighth lens having positive or negative optical power, wherein the object-side surface of the eighth lens is concave and the image-side surface of the eighth lens is convex. The third lens group has positive optical power, and the third lens group includes: A ninth lens with negative optical power, wherein the object-side surface of the ninth lens is concave and the image-side surface of the ninth lens is concave. A tenth lens with positive optical power, wherein the object-side surface of the tenth lens is convex and the image-side surface of the tenth lens is convex. An eleventh lens with positive optical power, wherein the image-side surface of the eleventh lens is convex; A twelfth lens with positive optical power, wherein the object-side surface of the twelfth lens is convex and the image-side surface of the twelfth lens is convex; Wherein, the first lens and the second lens are cemented together, the sixth lens and the seventh lens are cemented together, and the ninth lens and the tenth lens are cemented together; The optical system satisfies: -16.46≤f9 / CT9≤-13.80; 1.80<f10 / CT10<2.65; 3.20≤FG2 / FG3<3.65, Wherein, f9 is the effective focal length of the ninth lens, CT9 is the center thickness of the ninth lens, f10 is the effective focal length of the tenth lens, CT10 is the center thickness of the tenth lens, FG2 is the combined focal length of the second lens group, and FG3 is the combined focal length of the third lens group.

2. The optical system according to claim 1, characterized in that, The radius of curvature R1 of the object side of the first lens, the radius of curvature R4 of the image side of the second lens, and the combined focal length F12 of the first lens and the second lens satisfy: 0.10≤|R1+R4| / F12≤2.

89.

3. The optical system according to claim 1, characterized in that, The center thickness CT1 of the first lens, the center thickness CT2 of the second lens, the center thickness CT3 of the third lens, and the center thickness CT4 of the fourth lens satisfy: 1.35 < (CT1 + CT2) / (CT3 + CT4) ≤ 1.

75.

4. The optical system according to claim 1, characterized in that, The combined focal length F67 of the sixth lens and the seventh lens, and the center thickness CT7 of the seventh lens, satisfy: -11.08≤F67 / CT7≤-8.

09.

5. The optical system according to claim 1, characterized in that, The effective focal length f of the optical system and the air gap T89 between the eighth lens and the ninth lens on the optical axis satisfy: -10.44≤f / T89≤-6.

32.

6. The optical system according to claim 1, characterized in that, The combined focal length F910 of the ninth and tenth lenses, the effective focal length f11 of the eleventh lens, and the effective focal length f12 of the twelfth lens satisfy: 1.55≤|F910| / (f11+f12)≤5.

05.

7. The optical system according to claim 1, characterized in that, The axial distance TD between the object side of the first lens and the image side of the twelfth lens, and the combined focal length F91011 of the ninth, tenth, and eleventh lenses, satisfy: 2.20 < TD / F91011 ≤ 2.

60.

8. The optical system according to claim 1, characterized in that, The combined focal length FG1 of the first lens group and the combined focal length FG3 of the third lens group satisfy: 4.90 < FG1 / FG3 < 5.

30.

9. The optical system according to claim 1, characterized in that, The radius of curvature R9 of the object side of the fifth lens, the radius of curvature R10 of the image side of the fifth lens, and the effective focal length f5 of the fifth lens satisfy: -5.45 < (R9 + R10) / f5 < -3.

00.

10. The optical system according to claim 1, characterized in that, The radius of curvature R11 of the object side of the sixth lens, the radius of curvature R12 of the image side of the sixth lens, and the center thickness CT6 of the sixth lens satisfy: -4.00≤(R11+R12) / CT6≤-2.

70.

11. The optical system according to claim 1, characterized in that, The combined focal length FG2 of the second lens group, the center thickness CT5 of the fifth lens, and the center thickness CT8 of the eighth lens satisfy: 5.70 < FG2 / (CT5+CT8) < 6.

35.

12. The optical system according to claim 1, characterized in that, The effective focal length f2 of the second lens, the effective focal length f6 of the sixth lens, and the effective focal length f7 of the seventh lens satisfy: -6.76≤f2 / (f6+f7)≤-4.

70.

13. The optical system according to claim 1, characterized in that, The air gap T45 between the fourth and fifth lenses on the optical axis and the air gap T78 between the seventh and eighth lenses on the optical axis satisfy the following condition: 6.85≤T45 / T78≤7.

55.

14. The optical system according to claim 1, characterized in that, The sum of the air gaps on the optical axis of adjacent lenses from the first lens to the twelfth lens, ∑AT, and the air gap T1112 between the eleventh lens and the twelfth lens on the optical axis satisfy: 4.88≤∑AT / T1112≤9.

48.

15. The optical system according to claim 1, characterized in that, The sum of the center thicknesses of all lenses from the first lens to the twelfth lens, ∑CT, the effective radius of the object side of the first lens, DT11, and the effective radius of the image side of the twelfth lens, DT122, satisfy: 2.00 < ∑CT / (DT11 + DT122) < 2.

40.

16. The optical system according to claim 1, characterized in that, The optical system also includes an imaging lens and an imaging surface located on the image side of the twelfth lens. The outgoing light beam from the lens group enters the imaging lens to form an image on the imaging surface using the imaging lens.

17. An electronic device, characterized in that, Includes the optical system according to any one of claims 1-16.

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